77 results on '"Seidel CL"'
Search Results
2. Aortic actomyosin content of maturing normal and spontaneously hypertensive rats
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Seidel Cl
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Male ,medicine.medical_specialty ,Physiology ,business.industry ,Proteins ,Aorta, Thoracic ,Muscle, Smooth ,Actomyosin ,DNA ,Biology ,Rats ,Text mining ,Endocrinology ,Physiology (medical) ,Internal medicine ,Hypertension ,medicine ,Animals ,Cardiology and Cardiovascular Medicine ,business ,Muscle Contraction - Published
- 1979
3. Coronary artery cyclic AMP content during adrenergic receptor stimulation
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Seidel, CL, primary, Schnarr, RL, additional, and Sparks, HV, additional
- Published
- 1975
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4. Factors influencing heterogeneity of radiation-induced DNA-damage measured by the alkaline comet assay
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Seidel Clemens, Lautenschläger Christine, Dunst Jürgen, and Müller Arndt-Christian
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Heterogeneity ,Comet assay ,%Tail DNA ,Antioxidants ,Histones ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background To investigate whether different conditions of DNA structure and radiation treatment could modify heterogeneity of response. Additionally to study variance as a potential parameter of heterogeneity for radiosensitivity testing. Methods Two-hundred leukocytes per sample of healthy donors were split into four groups. I: Intact chromatin structure; II: Nucleoids of histone-depleted DNA; III: Nucleoids of histone-depleted DNA with 90 mM DMSO as antioxidant. Response to single (I-III) and twice (IV) irradiation with 4 Gy and repair kinetics were evaluated using %Tail-DNA. Heterogeneity of DNA damage was determined by calculation of variance of DNA-damage (V) and mean variance (Mvar), mutual comparisons were done by one-way analysis of variance (ANOVA). Results Heterogeneity of initial DNA-damage (I, 0 min repair) increased without histones (II). Absence of histones was balanced by addition of antioxidants (III). Repair reduced heterogeneity of all samples (with and without irradiation). However double irradiation plus repair led to a higher level of heterogeneity distinguishable from single irradiation and repair in intact cells. Increase of mean DNA damage was associated with a similarly elevated variance of DNA damage (r = +0.88). Conclusions Heterogeneity of DNA-damage can be modified by histone level, antioxidant concentration, repair and radiation dose and was positively correlated with DNA damage. Experimental conditions might be optimized by reducing scatter of comet assay data by repair and antioxidants, potentially allowing better discrimination of small differences. Amount of heterogeneity measured by variance might be an additional useful parameter to characterize radiosensitivity.
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- 2012
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5. Does age matter? - A MRI study on peritumoral edema in newly diagnosed primary glioblastoma
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Platten Michael, Wick Antje, Osswald Matthias, Dörner Nils, Seidel Clemens, Bendszus Martin, and Wick Wolfgang
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age ,brain tumor ,glioblastoma ,imaging ,necrosis ,vascular endothelial growth factor ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Peritumoral edema is a characteristic feature of malignant glioma related to the extent of neovascularisation and to vascular endothelial growth factor (VEGF) expression. The extent of peritumoral edema and VEGF expression may be prognostic for patients with glioblastoma. As older age is a negative prognostic marker and as VEGF expression is reported to be increased in primary glioblastoma of older patients, age-related differences in the extent of peritumoral edema have been assessed. Methods In a retrospective, single-center study, preoperative magnetic resonance imaging (MRI) scans of steroid-naïve patients (n = 122) of all age groups were analysed. Patients with clinically suspected, radiologically likely or known evidence of secondary glioblastoma were not included. Extent of brain edema was determined in a metric quantitative fashion and in a categorical fashion in relation to tumor size. Analysis was done group-wise related to age. Additionally, tumor size, degree of necrosis, superficial or deep location of tumor and anatomic localization in the brain were recorded. Results The extent of peritumoral edema in patients >65 years (ys) was not different from the edema extent in patients ≤ 65 ys (p = 0.261). The same was true if age groups ≤ 55 ys and ≥ 70 ys were compared (p = 0.308). However, extent of necrosis (p = 0.023), deep tumor localization (p = 0.02) and frontal localisation (p = 0.016) of the tumor were associated with the extent of edema. Tumor size was not linearly correlated to edema extent (Pearson F = 0.094, p = 0.303) but correlated to degree of necrosis (F = 0.355, p < 0.001, Spearman-Rho) and depth of tumor (p < 0.001). In a multifactorial analysis of maximum edema with the uncorrelated factors age, regional location of tumor and degree of necrosis, only the extent of necrosis (p = 0.022) had a significant effect. Conclusion Age at diagnosis does not determine degree of peritumoral edema, and tumor localization in the white matter is associated with greater extent of edema. The area of necrosis is reflective of volume of edema. In summary, the radiographic appearance of a glioblastoma at diagnosis does not reflect biology in the elderly patient.
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- 2011
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6. Dendritic/antigen presenting cell mediated provision of T-cell receptor gamma delta (TCRγδ) expressing cells contributes to improving antileukemic reactions ex vivo.
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Rackl E, Hartz A, Aslan Rejeski H, Li L, Klauer LK, Ugur S, Pepeldjiyska E, Amend C, Weinmann M, Doraneh-Gard F, Stein J, Reiter N, Seidel CL, Plett C, Amberger DC, Bojko P, Kraemer D, Schmohl J, Rank A, Schmid C, and Schmetzer HM
- Abstract
T-cell receptor gamma delta (TCRγδ) expressing T-cells are known to mediate an MHC-independent immune response and could therefore qualify for immune therapies. We examined the influence of dendritic cells(DC)/antigen presenting cell (APC) generated from blast-containing whole blood (WB) samples from AML and MDS patients on the provision of (leukemia-specific) TCRγδ expressing T-cells after mixed lymphocyte culture (MLC). Kit-M (granulocyte-macrophage colony-stimulating factor (GM-CSF) + prostaglandin E1 (PGE1)) or Kit-I (GM-CSF + Picibanil) were used to generate leukemia derived APC/DC (DC
leu )from WB, which were subsequently used to stimulate T-cell enriched MLC. Immune cell composition and functionality were analysed using degranulation- (DEG), intracellular cytokine- (INTCYT) and cytotoxicity fluorolysis- (CTX) assays. Flow cytometry was used for cell quantification. We found increased frequencies of APCs/DCs and their subtypes after Kit-treatment of healthy and patients´ WB compared to control, as well as an increased stimulation and activation of several types of immune reactive cells after MLC. Higher frequencies of TCRγδ expressing leukemia-specific degranulation and intracellularly cytokine producing T-cells were found. The effect of Kit-M-treatment on frequencies of TCRγδ expressing cells and their degranulation could be correlated with the Kit-M-mediated blast lysis compared to control. We also found higher frequencies of TCRγδ expressing T-cells in AML patients´ samples with an achieved remission (compared to blast persistence) after induction chemotherapy. This might point to APC/DC-mediated effects resulting in the provision of leukemia-specific TCRγδ expressing T-cells: Moreover a quantification of TCRγδ expressing T-cells might contribute to predict prognosis of AML/MDS patients., Competing Interests: Declaration of Competing Interest H.M.S. is involved with Modiblast Pharma GmbH (Oberhaching, Germany), holder of the European Patent 15 801 987.7–1118 and the US Patent 15–517627 “Use of immunomodulatory effective compositions for the immunotherapeutic treatment of patients suffering from myeloid leukemias”., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)- Published
- 2024
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7. Biomechanical simulation of segmented intrusion of a mandibular canine using Robot Orthodontic Measurement & Simulation System (ROSS).
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Sabbagh H, Dotzer B, Baumert U, Hötzel L, Seidel CL, and Wichelhaus A
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Objective: Aim of this study was to investigate the forces and moments during segmented intrusion of a mandibular canine using Cantilever-Intrusion-Springs (CIS)., Methods: Three different CIS modifications were investigated using a robotic biomechanical simulation system: unmodified CIS (#1, control), CIS with a lingual directed 6° toe-in bend (#2), and CIS with an additional 20° twist bend (#3). Tooth movement was simulated by the apparative robotic stand, controlled by a force-control algorithm, recording the acting forces and moments with a force-torque sensor. Statistical analysis was performed using Shapiro-Wilk, Kolmogorov-Smirnov, Kruskal-Wallis ANOVA and post hoc tests with Bonferroni correction (α = 0.05)., Results: The initial intrusive force, which was uniformly generated by a 35° Tip-Back bend, decreased significantly (p < 0.05) from 0.31 N in group (#1) to 0.28 N in group (#3). Vestibular crown tipping reduced significantly (p < 0.05) from 2.11° in group (#1) and 1.72° in group (#2) to 0.05° in group (#3). Matching to that the direction of orovestibular force significantly (p < 0.05) shifted from 0.15 N to vestibular in group (#1) to 0.51 N to oral in group (#3) and the orovestibular tipping moment decreased also significantly (p < 0.05) from 4.63 Nmm to vestibular in group (#1) to 3.56 Nmm in group (#2) and reversed to 1.20 Nmm to oral in group (#3). Apart from that the orovestibular displacement changed significantly (p < 0.05) from 0.66 mm in buccal direction in group (#1) to 0.29 mm orally in group (#2) and 1.49 mm in oral direction as well in group (#3)., Significance: None of the modifications studied achieved pure mandibular canine intrusion without collateral effects. The significant lingual displacement caused by modification (#3) is, not least from an aesthetic perspective, considered much more severe than a slight tipping of the canine. Consequently, modification (#2) can be recommended for clinical application based on the biomechanical findings., Competing Interests: Declaration of competing interest Have no conflict of interest to disclose., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)
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- 2024
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8. Torque expression of superelastic NiTi V-Slot and conventional stainless steel orthodontic bracket-archwire combinations - A finite element analysis.
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Stocker T, Wichelhaus A, Baumert U, Janjic Rankovic M, Seidel CL, and Sabbagh H
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- Humans, Orthodontic Wires, Finite Element Analysis, Stainless Steel chemistry, Torque, Nickel chemistry, Titanium chemistry, Orthodontic Brackets
- Abstract
Background: To investigate the torque expression of conventional stainless steel (SS) brackets in combination with rectangular SS archwires and nickel-titanium (NiTi) V-slot brackets in combination with V-shaped NiTi archwires using finite element analysis (FEA)., Methods: CAD models were created for a conventional bracket and rectangular archwires with dimensions of 0.018″x0.025″ and 0.019″x0.025″, and for a V-slot bracket and V-shaped archwires with heights of 0.55 mm, 0.60 mm and 0.70 mm. FEA was performed using Ansys 2022R2 software to assess the forces and moments during simulated torsion of the archwires in the brackets between 0° and 25° with varying interbracket distances and free path lengths., Results: The V-slot bracket-archwire combination exhibited force transmission and moment generation within 1° of torsion. The transmissible force increased with the torsion angle, but showed an upper limit of about 13-14 Nmm. The SS bracket-archwire combination showed negligible forces and moments for simulated torsion between 0° and 15°. At torsions of 25°, moments of 12 Nmm and 14 Nmm occurred for the 0.018″x0.025″ and 0.019″x0.025″ archwire dimensions, respectively., Conclusions: The V-slot bracket-archwire combination is effective in expressing torque and preventing both over- and under-activation. Conventional bracket-archwire combinations showed torsional losses due to play between 10 and 15°, depending on the dimensions of the respective archwire, and no upper torsional moment limit., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The author Prof. Dr. Andrea Wichelhaus codeveloped the RED bracket. The RED bracket is manufactured by Redsystem and she is a shareholder of said company. All other authors declare that they have no potential conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)
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- 2024
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9. Feasibility of 3 Tesla MRI for the assessment of mid-palatal suture maturation: a retrospective pilot study.
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Willershausen I, Kopp M, Scholz M, Ströbel A, Seidel CL, Paulsen F, Uder M, Gölz L, and May MS
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The maxilla occupies a key position in dentofacial orthopaedics, since its transversal development can be directly influenced by orthodontic therapy. The maturation stages of the mid-palatal suture, which are obtained from cone-beam computed tomography images (CBCT), present an addition to clinical decision-making in transversal discrepancies of the upper jaw. In an endeavour to reduce ionizing radiation in adolescents and young adults, who are particularly susceptible to long term stochastic irradiation effects, we investigated the feasibility of 3 Tesla (3T) MRI in detecting the maturation stages of the mid-palatal suture. A collective of 30 patients aged 24-93 years with routine neck MRI at 3T, underwent an additional three-dimensional isotropic T1 weighted study sequence of the midface. Image evaluation was performed on axial, multi-planar formatted reconstructions of the dataset aligned to the midline axis of the palate, and curved reconstructions aligned to the concavity of the palate. Inverted images helped to achieve an image impression similar to the well-known CBCT appearance. All datasets were reviewed by three readers and mid-palatal maturation was scored twice according to Angelieri et al. Intra- and inter-rater agreement were evaluated to measure the robustness of the images for clinical evaluation. 3T MRI deemed reliable for the assessment of mid-palatal suture maturation and hence for the appraisal of the hard palate and its adjacent sutures. The data of this pilot study display the feasibility of non-ionizing cross-sectional MRI for the determination of sutural maturation stages. These findings underline the potential of MRI for orthodontic treatment planning, further contributing to the avoidance of unnecessary radiation doses., (© 2024. The Author(s).)
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- 2024
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10. Biomechanical Simulation of Orthodontic En-Bloc Retraction Comparing Compound Technique and Sliding Mechanics Using a HOSEA Robotic Device.
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Sabbagh H, Haas E, Baumert U, Seidel CL, Hötzel L, and Wichelhaus A
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En-bloc retraction is a common procedure in orthodontic therapy. The application of palatal root torque moments is required to control incisor inclination during retraction, yet studies comparing forces and moments with respect to different mechanics are lacking. This study aimed to investigate the forces and moments during orthodontic en-bloc retraction using a robotic biomechanical simulation system, comparing two distinct approaches: (I) compound technique [stainless steel (SS) combined with nickel-titanium (NiTi)] using industrially pretorqued retraction-torque-archwires (RTA) in combination with NiTi closed coil springs; (II) conventional sliding mechanics using SS archwires with manually applied anterior twist bends in combination with elastic chains. Two dimensions (0.017" × 0.025" and 0.018" × 0.025") and ten archwires per group were investigated using 0.022" slot self-ligating brackets. Kruskal-Wallis tests with a significance level of α = 0.05 were conducted. The biomechanical simulation showed that en-bloc retraction was characterized by a series of tipping and uprighting movements, differing significantly regarding the examined mechanics. Collateral forces and moments occurred in all groups. Notably, RTA exhibited fewer extrusive forces. The most bodily movement was achieved with the compound technique and the 0.018" × 0.025" RTA. Sliding mechanics exhibited maximum palatal root torque moments of more than 20 Nmm, exceeding recommended values.
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- 2024
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11. Comparing Torque Transmission of Different Bracket Systems in Combination with Various Archwires Considering Play in the Bracket Slot: An In Vitro Study.
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Wichelhaus A, Guggenbühl S, Hötzel L, Seidel CL, Sabbagh H, and Hoffmann L
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This study aims to examine the play between various archwires and bracket systems, exploring potential variations in angle values for specific torque and torque values for a given angle along different bracket systems. Therefore, seven brackets systems were evaluated in conjunction with different stainless steel archwires of varying dimensions (0.016″ × 0.022″, 0.018″ × 0.025″, and 0.019″ × 0.025″). Biomechanical behavior during torque development and transmission was assessed using a six-component force/torque sensor. Torque angles (5-45°) were specified with subsequent torque measurement, and the sequence was reversed by setting the torque (5-30 Nmm) and measuring the angle. A reference measurement with 0 Nmm torque served to evaluate bracket slot play. Bracket play (0 Nmm) during palatal load ranged between 20.06° and 32.50° for 0.016″ × 0.022″ wire, 12.83° and 21.11° for 0.018″ × 0.025″ wire, and 8.39° and 18.73° for 0.019″ × 0.025″ wire. The BioQuick
® bracket exhibited the highest play, while Wave SL® and Damon® Q brackets demonstrated the lowest play ( p < 0.001). Significant differences ( p < 0.001) between the brackets were observed in the torque angles required to achieve torques of 5-20 Nmm. In summary, each bracket system has a different torque transmission, which is of great clinical importance in order to achieve correct torque transmission and avoid complications such as root resorption.- Published
- 2024
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12. Impact of different cephalometric skeletal configurations on anatomic midface parameters in adults.
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Willershausen I, Ehrenfried A, Krautkremer F, Ströbel A, Seidel CL, Paulsen F, Kopp M, Uder M, Gölz L, and May MS
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- Adult, Humans, Middle Aged, Retrospective Studies, Cephalometry methods, Palate, Hard, Face anatomy & histology, Maxilla diagnostic imaging, Maxilla anatomy & histology
- Abstract
Objectives: Skull morphology and growth patterns are essential for orthodontic treatment, impacting clinical decision making. We aimed to determine the association of different cephalometric skeletal configurations on midface parameters as measured in 3D CT datasets., Materials and Methods: After sample size calculation, a total of 240 fully dentulous patients between 20 and 79 years of age (mean age: 42 ± 15), who had received a CT of the skull within the scope of trauma diagnosis or intracranial bleeding, were retrospectively selected. On the basis of cephalometric analysis, using MPR reconstructions, patients were subdivided into three different vertical skull configurations (brachyfacial, mesofacial, dolichofacial) and the respective skeletal Class I, II, and III relationships. Anatomic parameters were measured using a three-dimensional post-processing console: the thickness of the maxillary and palatine bones as well as the alveolar crest, maxillary body and sutural length, width and height of the hard palate, maxillary facial wall thickness, and masseter muscle thickness and length., Results: Individuals with brachyfacial configurations had a significantly increased palatal and alveolar ridge thicknesses compared to those with dolichofacial- or mesofacial configurations. Brachyfacial configurations presented a significantly increased length and thickness of the masseter muscle (4.599 cm; 1.526 cm) than mesofacial (4.431 cm; 1.466 cm) and dolichofacial configurations (4.405 cm; 1.397 cm) (p < 0.001). Individuals with a skeletal Class III had a significantly shorter palatal length (5.313 cm) than those with Class I (5.406 cm) and Class II (5.404 cm) (p < 0.01). Sutural length was also significantly shorter in Class III (p < 0.05)., Conclusions: Skeletal configurations have an impact on parameters of the bony skull. Also, measurable adaptations of the muscular phenotype could result., Clinical Relevance: The association between viscerocranial morphology and midface anatomy might be beneficial for tailoring orthodontic appliances to individual anatomy and planning cortically anchored orthodontic appliances., (© 2023. The Author(s).)
- Published
- 2023
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13. Investigation of Forces and Moments during Orthodontic Tooth Intrusion Using Robot Orthodontic Measurement and Simulation System (ROSS).
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Seidel CL, Lipp J, Dotzer B, Janjic Rankovic M, Mertmann M, Wichelhaus A, and Sabbagh H
- Abstract
The Robot Orthodontic Measurement and Simulation System (ROSS) is a novel biomechanical, dynamic, self-regulating setup for the simulation of tooth movement. The intrusion of the front teeth with forces greater than 0.5 N poses a risk for orthodontic-induced inflammatory root resorption (OIIRR). The aim was to investigate forces and moments during simulated tooth intrusion using ROSS. Five specimens of sixteen unmodified NiTi archwires and seven NiTi archwires with intrusion steps from different manufacturers (Forestadent, Ormco, Dentsply Sirona) with a 0.012″/0.014″/0.016″ wire dimension were tested. Overall, a higher wire dimension correlated with greater intrusive forces F
z (0.012″: 0.561-0.690 N; 0.014″: 0.996-1.321 N; 0.016″: 1.44-2.254 N) and protruding moments Mx (0.012″: -2.65 to -3.922 Nmm; 0.014″: -4.753 to -7.384 Nmm; 0.016″: -5.556 to -11.466 Nmm) during the simulated intrusion of a 1.6 mm-extruded upper incisor. However, the 'intrusion efficiency' parameter was greater for smaller wire dimensions. Modification with intrusion steps led to an overcompensation of the intrusion distance; however, it led to a severe increase in Fz and Mx , e.g., the Sentalloy 0.016″ medium (Dentsply Sirona) exerted 2.891 N and -19.437 Nmm. To reduce the risk for OIIRR, 0.014″ NiTi archwires can be applied for initial aligning (without vertical challenges), and intrusion steps for the vertical levelling of extruded teeth should be bent in the initial archwire, i.e., 0.012″ NiTi.- Published
- 2023
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14. The impact of passive alveolar molding vs. nasoalveolar molding on cleft width and other parameters of maxillary growth in unilateral cleft lip palate.
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Parhofer R, Rau A, Strobel K, Gölz L, Stark R, Ritschl LM, Wolff KD, Kesting MR, Grill FD, and Seidel CL
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- Infant, Humans, Nose surgery, Nasoalveolar Molding, Retrospective Studies, Maxilla surgery, Treatment Outcome, Preoperative Care methods, Cleft Lip surgery, Cleft Palate surgery
- Abstract
Objective: Passive alveolar molding (PAM) and nasoalveolar molding (NAM) are established presurgical infant orthodontic (PSIO) therapies for cleft lip palate (CLP) patients. PAM guides maxillary growth with a modified Hotz appliance, while NAM also uses extraoral taping and includes nasal stents. The effects of these techniques on alveolar arch growth have rarely been compared., Material and Methods: We retrospectively compared 3D-scanned maxillary models obtained before and after PSIO from infants with unilateral, non-syndromic CLP treated with PAM (n = 16) versus NAM (n = 13). Nine anatomical points were set digitally by four raters and transversal/sagittal distances and rotations of the maxilla were measured., Results: Both appliances reduced the anterior cleft, but NAM percentage wise more. NAM decreased the anterior and medial transversal width compared to PAM, which led to no change. With both appliances, the posterior width increased. The alveolar arch length of the great and small segments and the sagittal length of the maxilla increased with PAM but only partially with NAM. However, NAM induced a significant greater medial rotation of the larger and smaller segment compared to PAM with respect to the lateral angle., Conclusions: NAM and PAM presented some significant differences regarding maxillary growth. While NAM reduced the anterior cleft and effectively rotated the segments medially, PAM allowed more transversal and sagittal growth., Clinical Relevance: The results of this study should be taken into consideration when to decide whether to use PAM or NAM, since they show a different outcome within the first few months. Further studies are necessary regarding long-term differences., (© 2023. The Author(s).)
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- 2023
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15. Thermal Programming of Commercially Available Orthodontic NiTi Archwires.
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Wichelhaus A, Mehnert A, Stocker T, Baumert U, Mertmann M, Sabbagh H, and Seidel CL
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The shape of superelastic Nickel-Titanium (NiTi) archwires can be adjusted with thermal treatments using devices such as the Memory-Maker
TM (Forestadent), which potentially affects their mechanical properties. The effect of such treatments on these mechanical properties was simulated by means of a laboratory furnace. Fourteen commercially available NiTi wires (0.018″ × 0.025″) were selected from the manufacturers American Orthodontics, Dentaurum, Forestadent, GAC, Ormco, Rocky Mountain Orthodontics and 3M Unitek. Specimens were heat treated using different combinations of annealing duration (1/5/10 min) and annealing temperature (250-800 °C) and investigated using angle measurements and three-point bending tests. Complete shape adaptation was found at distinct annealing durations/temperatures for each wire ranging between ~650-750 °C (1 min), ~550-700 °C (5 min) and ~450-650 °C (10 min), followed by a loss of superelastic properties shortly afterwards at ~750 °C (1 min), ~600-650 °C (5 min) and ~550-600 °C (10 min). Wire-specific working ranges (complete shaping without loss of superelasticity) were defined and a numerical score (e.g., stable forces) was developed for the three-point bending test. Overall, the wires Titanol Superelastic (Forestadent), Tensic (Dentaurum), FLI CuNiTi27 (Rocky Mountain Orthodontics) and Nitinol Classic (3M Unitek) proved to be the most user-friendly. Thermal shape adjustment requires wire-specific working ranges to allow complete shape acceptance and high scores in bending test performance to ensure permanence of the superelastic behaviour.- Published
- 2023
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16. Cinematic rendering to improve visualization of supplementary and ectopic teeth using CT datasets.
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Willershausen I, Necker F, Kloeckner R, Seidel CL, Paulsen F, Gölz L, and Scholz M
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- Child, Humans, Software, Head, Tomography, X-Ray Computed methods, Imaging, Three-Dimensional methods
- Abstract
Objectives: Ectopic, impacted, and supplementary teeth are the number one reason for cross-sectional imaging in pediatric dentistry. The accurate post-processing of acquired data sets is crucial to obtain precise, yet also intuitively understandable three-dimensional (3D) models, which facilitate clinical decision-making and improve treatment outcomes. Cinematic rendering (CR) is anovel visualization technique using physically based volume rendering to create photorealistic images from DICOM data. The aim of the present study was to tailor pre-existing CR reconstruction parameters for use in dental imaging with the example of the diagnostic 3D visualization of ectopic, impacted, and supplementary teeth., Methods: CR was employed for the volumetric image visualization of midface CT data sets. Predefined reconstruction parameters were specifically modified to visualize the presented dental pathologies, dentulous jaw, and isolated teeth. The 3D spatial relationship of the teeth, as well as their structural relationship with the antagonizing dentition, could immediately be investigated and highlighted by separate, interactive 3D visualization after segmentation through windowing., Results: To the best of our knowledge, CR has not been implemented for the visualization of supplementary and ectopic teeth segmented from the surrounding bone because the software has not yet provided appropriate customized reconstruction parameters for dental imaging. When employing our new, modified reconstruction parameters, its application presents a fast approach to obtain realistic visualizations of both dental and osseous structures., Conclusions: CR enables dentists and oral surgeons to gain an improved 3D understanding of anatomical structures, allowing for more intuitive treatment planning and patient communication.
- Published
- 2023
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17. Orofacial clefts alter early life oral microbiome maturation towards higher levels of potentially pathogenic species: A prospective observational study.
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Seidel CL, Strobel K, Weider M, Tschaftari M, Unertl C, Willershausen I, Weber M, Hoerning A, Morhart P, Schneider M, Beckmann MW, Bogdan C, Gerlach RG, and Gölz L
- Abstract
Orofacial clefts (OFC) present different phenotypes with a postnatal challenge for oral microbiota development. In order to investigate the impact of OFC on oral microbiota, smear samples from 15 neonates with OFC and 17 neonates without OFC were collected from two oral niches (tongue, cheek) at two time points, i.e. after birth (T0: Ø3d OFC group; Ø2d control group) and 4-5 weeks later (T1: Ø32d OFC group; Ø31d control group). Subsequently, the samples were analyzed using next-generation sequencing. We detected a significant increase of alpha diversity and anaerobic and Gram-negative species from T0 to T1 in both groups. Further, we found that at T1 OFC neonates presented a significantly lower alpha diversity (lowest values for high cleft severity) and significantly higher levels of Enterobacteriaceae (Citrobacter, Enterobacter, Escherichia-Shigella, Klebsiella), Enterococcus, Bifidobacterium, Corynebacterium, Lactocaseibacillus, Staphylococcus, Acinetobacter and Lawsonella compared to controls. Notably, neonates with unilateral and bilateral cleft lip and palate (UCLP/BCLP) presented similarities in beta diversity and a mixture with skin microbiota. However, significant differences were seen in neonates with cleft palate only compared to UCLP/BCLP with higher levels of anaerobic species . Our findings revealed an influence of OFC as well as cleft phenotype and severity on postnatal oral microbiota maturation., Competing Interests: No potential conflict of interest was reported by the authors., (© 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)
- Published
- 2023
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18. Dendritic Cell-Triggered Immune Activation Goes along with Provision of (Leukemia-Specific) Integrin Beta 7-Expressing Immune Cells and Improved Antileukemic Processes.
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Rackl E, Li L, Klauer LK, Ugur S, Pepeldjiyska E, Seidel CL, Gunsilius C, Weinmann M, Doraneh-Gard F, Reiter N, Plett C, Amberger DC, Bojko P, Kraemer D, Schmohl J, Rank A, Schmid C, and Schmetzer HM
- Subjects
- Humans, Dendritic Cells, Lymphocyte Activation, Cytokines metabolism, Integrins metabolism, Granulocyte-Macrophage Colony-Stimulating Factor metabolism, Leukemia, Myeloid, Acute metabolism
- Abstract
Integrin beta 7 (β7), a subunit of the integrin receptor, is expressed on the surface of immune cells and mediates cell-cell adhesions and interactions, e.g., antitumor or autoimmune reactions. Here, we analyzed, whether the stimulation of immune cells by dendritic cells (of leukemic derivation in AML patients or of monocyte derivation in healthy donors) leads to increased/leukemia-specific β7 expression in immune cells after T-cell-enriched mixed lymphocyte culture-finally leading to improved antileukemic cytotoxicity. Healthy, as well as AML and MDS patients' whole blood (WB) was treated with Kit-M (granulocyte-macrophage colony-stimulating factor (GM-CSF) + prostaglandin E1 (PGE1)) or Kit-I (GM-CSF + Picibanil) in order to generate DCs (DC
leu or monocyte-derived DC), which were then used as stimulator cells in MLC. To quantify antigen/leukemia-specific/antileukemic functionality, a degranulation assay (DEG), an intracellular cytokine assay (INTCYT) and a cytotoxicity fluorolysis assay (CTX) were used. (Leukemia-specific) cell subtypes were quantified via flow cytometry. The Kit treatment of WB (compared to the control) resulted in the generation of DC/DCleu , which induced increased activation of innate and adaptive cells after MLC. Kit-pretreated WB (vs. the control) led to significantly increased frequencies of β7-expressing T-cells, degranulating and intracellular cytokine-producing β7-expressing immune cells and, in patients' samples, increased blast lysis. Positive correlations were found between the Kit-M-mediated improvement of blast lysis (vs. the control) and frequencies of β7-expressing T-cells. Our findings indicate that DC-based immune therapies might be able to specifically activate the immune system against blasts going along with increased frequencies of (leukemia-specific) β7-expressing immune cells. Furthermore, β7 might qualify as a predictor for the efficiency and the success of AML and/or MDS therapies., Competing Interests: H.M.S. is involved with Modiblast Pharma GmbH (Oberhaching, Germany), which holds the European Patent 15 801 987.7-1118 and US Patent 15-517627, “Use of immunomodulatory effective compositions for the immunotherapeutic treatment of patients suffering from myeloid leukemias”.- Published
- 2022
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19. Orofacial clefts lead to increased pro-inflammatory cytokine levels on neonatal oral mucosa.
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Seidel CL, Percivalle E, Tschaftari M, Weider M, Strobel K, Willershausen I, Unertl C, Schmetzer HM, Weber M, Schneider M, Frey B, Gaipl US, Beckmann MW, and Gölz L
- Subjects
- Female, Child, Infant, Infant, Newborn, Humans, Cytokines, Mouth Mucosa, Interleukin-6, Inflammation Mediators, Cleft Lip, Cleft Palate
- Abstract
Orofacial clefts (OFC) are frequent congenital malformations characterized by insufficient separation of oral and nasal cavities and require presurgical infant orthopedics and surgical interventions within the first year of life. Wound healing disorders and higher prevalence of gingivitis and plaque levels are well-known challenges in treatment of children with OFC. However, oral inflammatory mediators were not investigated after birth using non-invasive sampling methods so far. In order to investigate the impact of OFC on oral cytokine levels, we collected tongue smear samples from 15 neonates with OFC and 17 control neonates at two time points (T), T0 at first consultation after birth, and T1, 4 to 5 weeks later. The samples were analyzed using multiplex immunoassay. Overall, we found significantly increased cytokine levels (TNF, IL-1β/-2/-6/-8/-10) in tongue smear samples from neonates with OFC compared to controls, especially at T0. The increase was even more pronounced in neonates with a higher cleft severity. Further, we detected a significant positive correlation between cleft severity score and distinct pro-inflammatory mediators (GM-CSF, IL-1β, IL-6, IL-8) at T0. Further, we found that breast-milk (bottle) feeding was associated with lower levels of pro-inflammatory cytokines (IL-6/-8) in neonates with OFC compared to formula-fed neonates. Our study demonstrated that neonates with OFC, especially with high cleft severity, are characterized by markedly increased inflammatory mediators in tongue smear samples within the first weeks of life potentially presenting a risk for oral inflammatory diseases. Therefore, an inflammatory monitoring of neonates with (severe) OFC and the encouragement of mother to breast-milk (bottle) feed might be advisable after birth and/or prior to cleft surgery., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Seidel, Percivalle, Tschaftari, Weider, Strobel, Willershausen, Unertl, Schmetzer, Weber, Schneider, Frey, Gaipl, Beckmann and Gölz.)
- Published
- 2022
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20. The comparison of the morphology of the mid-palatal suture between edentulous individuals and dentate jaws shows morphological differences.
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Willershausen I, Krautkremer F, Hilbert T, Seidel CL, Geppert CI, Ghanaati S, Necker F, Paulsen F, Gölz L, and Scholz M
- Subjects
- Humans, Maxilla, Palate, Sutures, Palatal Expansion Technique, Tooth
- Abstract
Background: A profound understanding of the evolution and anatomy of the viscero- and neurocranium is quintessentially important for orthodontists. This particularly alludes to structures, which are directly targeted by orthodontic therapy such as the maxilla and the mid-palatal suture. The anatomy of the mid-palatal suture of toothed individuals is well described, whereas little is known about sutures' morphological changes after tooth loss. Therefore, the aim of this study was to evaluate the edentulous mid-palatal suture by means of histologic and histomorphometric analysis., Methods: Ten mid-palatal sutures of edentulous donors as well as six age- and sex matched dentulous controls were examined. For the histological and histomorphometric analysis (sutural width, obliteration, vascularization and interdigitation) conventional staining protocols (HE, Movat-Pentachrome, Sirius Red) and immunofluorescence (vWF, TRAP) were performed. Histomorphometric analysis was carried out using NIS-elements imaging software., Results: When compared to dentulous controls, the edentulous investigation group showed a decreased vascularization and sutural width as well as an increased sutural obliteration. Notably, a high variability and inhomogeneity within regard the histomorphometric parameters was seen in edentulous samples., Conclusions: The mid-palatal suture of edentulous individuals showed significant morphological differences compared to individuals with toothed jaws. The loss of teeth and thereby functional loading seems to have a considerable impact on sutures' morphology., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier GmbH. All rights reserved.)
- Published
- 2022
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21. Leukemia derived dendritic cell (DC leu ) mediated immune response goes along with reduced (leukemia-specific) regulatory T-cells.
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Pepeldjiyska E, Li L, Gao J, Seidel CL, Blasi C, Özkaya E, Schmohl J, Kraemer D, Schmid C, Rank A, and Schmetzer HM
- Subjects
- Dendritic Cells, Humans, Immunophenotyping, Lymphocyte Activation, Leukemia, Myeloid, Acute, T-Lymphocytes, Regulatory
- Abstract
The blastmodulatory Kit-M, composed of granulocyte-macrophage colony-stimulating-factor (GM-CSF) and Prostaglandin E1 (PGE
1 ), is known to convert myeloid leukaemic blasts (from AML patients) into leukaemia derived dendritic cells (DCleu ), which activate immunoreactive cells to gain antileukemic/leukaemia-specific activity. In this study we had a special focus on the influence of Kit-M treated, DC/DCleu containing patients'whole blood (WB, n = 16) on the provision of immunosuppressive regulatory T-cells. We could confirm that Kit-M significantly increased frequencies of (mature) dendritic cells (DC) and DCleu from leukemic whole blood (WB) without induction of blast proliferation. After mixed lymphocyte culture (MLC) with patients' T-cells we confirmed that DCleu mediated leukemia-specific responses- going along with activated and leukemia-specific T- and NK-cells in an intracellular cytokine staining assay (ICS) and a degranulation assay (Deg)- resulted in an increased anti-leukemic cytotoxicity (Cytotoxicity Fluorolysis Assay = CTX). We could demonstrate that (leukemia-specific) CD4+ and CD8+ regulatory T-cell population (Treg ) decreased significantly after MLC compared to controls. We found significant positive correlations of leukemia-specific CD3+ CD4+ cells with frequencies of (mature) DCleu . Achieved anti-leukemic cytotoxicity correlated significantly positive with leukemia-specific CD3+ CD8+ cells and significantly negatively with (leukemia-specific) Treg . In summary we demonstrate that immunesuppressive (leukemia-specific) regulatory T-cells are significantly downregulated after Kit-M triggered MLC- going along with a (reinstalled) antileukemic reactivity of the immune system (as demonstrated with functional assays ICS, Deg, CTX)., (Copyright © 2022. Published by Elsevier GmbH.)- Published
- 2022
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22. Influence of probiotics on the periodontium, the oral microbiota and the immune response during orthodontic treatment in adolescent and adult patients (ProMB Trial): study protocol for a prospective, double-blind, controlled, randomized clinical trial.
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Seidel CL, Gerlach RG, Weider M, Wölfel T, Schwarz V, Ströbel A, Schmetzer H, Bogdan C, and Gölz L
- Subjects
- Adolescent, Adult, Child, Cytokines, Dysbiosis, Humans, Immunity, Inflammation, Periodontium, Prospective Studies, Randomized Controlled Trials as Topic, Microbiota, Probiotics therapeutic use
- Abstract
Background: Orthodontic treatment with fixed appliances is often necessary to correct malocclusions in adolescence or adulthood. However, oral hygiene is complicated by appliances, and prior studies indicate that they may trigger oral inflammation and dysbiosis of the oral microbiota, especially during the first 3 months after insertion, and, thus, may present a risk for inflammatory oral diseases. In recent periodontal therapeutic studies, probiotics have been applied to improve clinical parameters and reduce local inflammation. However, limited knowledge exists concerning the effects of probiotics in orthodontics. Therefore, the aim of our study is to evaluate the impact of probiotics during orthodontic treatment., Methods: This study is a monocentric, randomized, double blind, controlled clinical study to investigate the effectiveness of daily adjuvant use of Limosilactobacillus reuteri (Prodentis®-lozenges, DSM 17938, ATCC PTA 5289) versus control lozenges during the first three months of orthodontic treatment with fixed appliances. Following power analysis, a total of 34 adolescent patients (age 12-17) and 34 adult patients (18 years and older) undergoing orthodontic treatment at the University Hospital Erlangen will be assigned into 2 parallel groups using a randomization plan for each age group. The primary outcome measure is the change of the gingival index after 4 weeks. Secondary outcomes include the probing pocket depth, the modified plaque index, the composition of the oral microbiota, the local cytokine expression and-only for adults-serum cytokine levels and the frequencies of cells of the innate and adaptive immune system in peripheral blood., Discussion: Preventive strategies in everyday orthodontic practice include oral hygiene instructions and regular dental cleaning. Innovative methods, like adjuvant use of oral probiotics, are missing. The aim of this study is to analyse, whether probiotics can improve clinical parameters, reduce inflammation and prevent dysbiosis of the oral microbiota during orthodontic treatment. If successful, this study will provide the basis for a new strategy of prophylaxis of oral dysbiosis-related diseases during treatment with fixed appliances., Trial Registration: This trial is registered at ClinicalTrials.gov in two parts under the number NCT04598633 (Adolescents, registration date 10/22/2020), and NCT04606186 (Adults, registration date 10/28/2020)., (© 2022. The Author(s).)
- Published
- 2022
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23. Expression of Surface-associated 82 kDa proMMP-9 in Lymphatic Leukemia Blast Cells Differentially Correlates With Prognosis.
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Schmohl J, Moebius S, Guenther T, Pepeldjyika E, Seidel CL, Sutanto W, Schuster F, Kraemer D, Salih H, Hartmann A, Tischer J, Ries C, and Schmetzer H
- Subjects
- Adolescent, Adult, Aged, Bone Marrow Cells cytology, Child, Child, Preschool, Female, Humans, Male, Middle Aged, Prognosis, Young Adult, Enzyme Precursors immunology, Leukemia, Lymphocytic, Chronic, B-Cell immunology, Lymphocytes immunology, Matrix Metalloproteinase 9 immunology, Precursor Cell Lymphoblastic Leukemia-Lymphoma immunology
- Abstract
Background/aim: Matrix metalloproteinases (MMPs) degrade extracellular matrix and process regulatory proteins. Recently, a membrane-bound 82kDa variant of proMMP-9 identified on myeloid blasts was shown to be associated with prognosis., Patients and Methods: To investigate the role of 82kDa proMMP-9 with acute lymphoblastic leukemia (ALL) and chronic lymphoid leukemia (CLL), we performed flow-cytometry analysis of expression on ALL blasts (n=18) and CLL lymphocytes (n=21) from blood and correlated data with clinical parameters., Results: In ALL, mature B-linear blasts expressed higher levels of 82kDa proMMP-9 compared to T-linear blasts. Elevated levels of 82kDa proMMP-9 were found in elderly patients and at patients with relapse. No correlation was observed on blood cells and extramedullary disease. In CLL, the 82kDa proMMP-9 expression did not correlate with any of the clinical parameters., Conclusion: Our findings suggest that higher levels of 82kDa proMMP-9 expression on blast cells may correlate with a more unfavorable ALL-subtype. Further studies are required to clarify the prognostic role of the 82kDa pro-MMP-9 expression., (Copyright © 2021 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)
- Published
- 2021
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24. Influence of Natural Killer Cells and Natural Killer T Cells on Periodontal Disease: A Systematic Review of the Current Literature.
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Seidel A, Seidel CL, Weider M, Junker R, Gölz L, and Schmetzer H
- Subjects
- Animals, Humans, Immunity, Innate immunology, Killer Cells, Natural immunology, Natural Killer T-Cells immunology, Periodontal Diseases immunology, Periodontal Diseases pathology
- Abstract
Natural killer (NK) cells, as members of the innate immune system, and natural killer T (NKT) cells, bridging innate and adaptive immunity, play a prominent role in chronic inflammatory diseases and cancerogenesis, yet have scarcely been examined in oral diseases. Therefore, systematic research on the latest literature focusing on NK/NKT cell-mediated mechanisms in periodontal disease, including the time period 1988-2020, was carried out in MEDLINE (PubMed) using a predetermined search strategy, with a final selection of 25 studies. The results showed that NK cells tend to have rather proinflammatory influences via cytokine production, cytotoxic effects, dendritic-cell-crosstalk, and autoimmune reactions, while contrarily, NKT cell-mediated mechanisms were proinflammatory and immunoregulatory, ranging from protective effects via B-cell-regulation, specific antibody production, and the suppression of autoimmunity to destructive effects via cytokine production, dendritic-cell-crosstalk, and T-/B-cell interactions. Since NK cells seem to have a proinflammatory role in periodontitis, further research should focus on the proinflammatory and immunoregulatory properties of NKT cells in order to create, in addition to antibacterial strategies in dental inflammatory disease, novel anti-inflammatory therapeutic approaches modulating host immunity towards dental health.
- Published
- 2020
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25. Defining Metaniches in the Oral Cavity According to Their Microbial Composition and Cytokine Profile.
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Seidel CL, Gerlach RG, Wiedemann P, Weider M, Rodrian G, Hader M, Frey B, Gaipl US, Bozec A, Cieplik F, Kirschneck C, Bogdan C, and Gölz L
- Subjects
- Adult, DNA, Bacterial analysis, Female, Gingival Crevicular Fluid microbiology, Humans, Male, Mouth metabolism, Palate microbiology, RNA, Ribosomal, 16S analysis, Saliva microbiology, Tongue microbiology, Young Adult, Cytokines metabolism, Microbiota physiology, Mouth microbiology
- Abstract
The human oral microbiota consists of over 700 widespread taxa colonizing the oral cavity in several anatomically diverse oral niches. Lately, sequencing of the 16S rRNA genes has become an acknowledged, culture-independent method to characterize the oral microbiota. However, only a small amount of data are available concerning microbial differences between oral niches in periodontal health and disease. In the context of periodontitis, the cytokine expression in the gingival crevicular fluid has been studied in detail, whereas little is known about the cytokine profile in hard and soft tissue biofilms. In order to characterize oral niches in periodontal health, the oral microbiota and cytokine pattern were analyzed at seven different sites (plaque (P), gingival crevicular fluid (GCF), saliva (S), tongue (T), hard palate (HP), cheek (C) and sublingual area (U)) of 20 young adults using next-generation sequencing and multiplex immunoassays. Site-specific microbial compositions were detected, which clustered into three distinct metaniches ("P-GCF", "S-T-HP" and "C-U") and were associated with niche-/metaniche-specific cytokine profiles. Our findings allow the definition of distinct metaniches according to their microbial composition, partly reflected by their cytokine profile, and provide new insights into microenvironmental similarities between anatomical diverse oral niches.
- Published
- 2020
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26. A Human Periodontal Ligament Fibroblast Cell Line as a New Model to Study Periodontal Stress.
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Weider M, Schröder A, Docheva D, Rodrian G, Enderle I, Seidel CL, Andreev D, Wegner M, Bozec A, Deschner J, Kirschneck C, Proff P, and Gölz L
- Subjects
- Cell Line, Cell Proliferation, Fibroblasts cytology, Fibroblasts metabolism, Glass, Humans, Models, Biological, Periodontal Ligament metabolism, Stress, Mechanical, Tooth Movement Techniques, Cell Culture Techniques instrumentation, Periodontal Ligament cytology, Telomerase metabolism
- Abstract
The periodontal ligament (PDL) is exposed to different kinds of mechanical stresses such as bite force or orthodontic tooth movement. A simple and efficient model to study molecular responses to mechanical stress is the application of compressive force onto primary human periodontal ligament fibroblasts via glass disks. Yet, this model suffers from the need for primary cells from human donors which have a limited proliferative capacity. Here we show that an immortalized cell line, PDL-hTERT, derived from primary human periodontal ligament fibroblasts exhibits characteristic responses to glass disk-mediated compressive force resembling those of primary cells. These responses include induction and secretion of pro-inflammatory markers, changes in expression of extracellular matrix-reorganizing genes and induction of genes related to angiogenesis, osteoblastogenesis and osteoclastogenesis. The fact that PDL-hTERT cells can easily be transfected broadens their usefulness, as molecular gain- and loss-of-function studies become feasible.
- Published
- 2020
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27. Team learning in medical education: initial experiences at ten institutions.
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Searle NS, Haidet P, Kelly PA, Schneider VF, Seidel CL, and Richards BF
- Subjects
- Education, Medical, Undergraduate methods, Humans, Internship and Residency methods, Physician Assistants education, United States, Curriculum, Group Processes, Program Evaluation, Teaching methods
- Abstract
Purpose: In the midst of curricular reforms that frequently call for reducing lectures and increasing small-group teaching, there is a crisis in faculty time for teaching. This paper describes the initial experiences of ten institutions with team learning (TL), a teaching method which fosters small-group learning in a large-class setting., Method: After initial pilot studies at one institution, nine additional institutions implemented TL in one or more courses., Results: Within 18 months, TL has been used in 40 courses (from.5% to 100% of the time) and all ten institutions will increase its use next year., Conclusions: We surmise that this relatively rapid spread of TL into the medical curriculum is due to the sound pedagogy and efficiency of TL as well as the modest financial resources and support we have provided to partner institutions.
- Published
- 2003
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28. Validation of an observation instrument for measuring student engagement in health professions settings.
- Author
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O'Malley KJ, Moran BJ, Haidet P, Seidel CL, Schneider V, Morgan RO, Kelly PA, and Richards B
- Subjects
- Humans, Observer Variation, Reproducibility of Results, Health Occupations education, Students, Health Occupations
- Abstract
Documenting student engagement has received increased emphasis in medical schools, as teaching strategies are changing to include more student-to-student interactions. The purpose of this study was to develop and evaluate a measure of student engagement completed by independent observers that would not interfere with student learning time. Data from 3,182 observations completed by nine observers in 32 educational classroom settings with 23 different instructors were used to evaluate the interobserver reliability and gather validity evidence for our observational instrument, named the STROBE. Results indicated that interobserver agreement was good to excellent when observations were conducted simultaneously on randomly selected students in the same classroom (84% average agreement and 0.79 average kappa coefficient) and when observations were conducted on different randomly selected students (79% average agreement). Results also provided strong evidence for validity. Overall, findings indicate that the STROBE demonstrates promise for educational research and evaluation by documenting student engagement in medical education settings.
- Published
- 2003
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29. Application of team learning in a medical physiology course.
- Author
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Seidel CL and Richards BF
- Subjects
- Attitude of Health Personnel, Focus Groups, Humans, Program Evaluation, Education, Medical, Undergraduate organization & administration, Group Processes, Interprofessional Relations, Patient Care Team organization & administration, Physiology education, Problem-Based Learning organization & administration, Students, Medical psychology
- Published
- 2001
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30. Use of streaming video in preclinical lectures.
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Seidel CL, Wheeler DA, and Richards BF
- Subjects
- Humans, United States, Education, Medical, Undergraduate methods, Teaching Materials, Video Recording
- Published
- 2000
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31. Expression of plasma membrane calcium ATPases in phenotypically distinct canine vascular smooth muscle cells.
- Author
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Abramowitz J, Aydemir-Koksoy A, Helgason T, Jemelka S, Odebunmi T, Seidel CL, and Allen JC
- Subjects
- Alternative Splicing, Amino Acid Sequence, Androstadienes pharmacology, Animals, Base Sequence, Calcium-Transporting ATPases genetics, Calcium-Transporting ATPases metabolism, Carotid Arteries cytology, Cation Transport Proteins, Cell Membrane enzymology, Cells, Cultured, DNA Primers, DNA, Complementary, Dogs, Enzyme Inhibitors pharmacology, Female, Gene Expression, Humans, Male, Molecular Sequence Data, Muscle, Smooth, Vascular cytology, Phenotype, Plasma Membrane Calcium-Transporting ATPases, RNA, Messenger, Saphenous Vein cytology, Sequence Homology, Amino Acid, Wortmannin, Calcium-Transporting ATPases biosynthesis, Carotid Arteries enzymology, Muscle, Smooth, Vascular enzymology, Saphenous Vein enzymology
- Abstract
Our laboratory has identified at least two types of vascular smooth muscle cells (VSMCs) that exist in canine arteries and veins: type 1 cells, located in the media express muscle specific proteins but do not proliferate in culture; and type 2 cells, located in both media and adventitia, do not express muscle specific protein but proliferate in culture. Plasma membrane Ca(2+)-ATPases (PMCAs) have been implicated in proliferation control. The present study examines the expression of PMCA isoforms and calmodulin-binding domain splice variants in these two types of canine VSMCs. PMCA protein was found in both type 1 and type 2 cells. Reverse transcriptase-polymerase chain reaction assays were developed for canine PMCA calmodulin-binding domain splice variants. We cloned and sequenced isolates corresponding to PMCA1b, 4a and 4b from canine VSMCs. PMCA 2 and 3 were not detected. Freshly isolated type 1 cells expressed PMCA 1b, 4a and 4b, while freshly isolated type 2 cells expressed PMCA1b and 4b. Upon placement in culture, type 2 cells originating from either carotid artery or saphenous vein demonstrated a time-dependent upregulation of PMCA4a mRNA. Treatment with the phosphoinositide 3-kinase inhibitor wortmannin produced concentration-dependent inhibition of both PMCA4a upregulation and [(3)H]thymidine incorporation. These findings suggest a role for phosphoinositide 3-kinase in regulating PMCA expression, which may be important in the control of Ca(2+)-sensitive VSMC functions., (Copyright 2000 Academic Press.)
- Published
- 2000
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32. Protein kinase C mediates insulin-inhibited Ca2+ transport and contraction of vascular smooth muscle.
- Author
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Kahn AM, Allen JC, Seidel CL, and Song T
- Subjects
- Animals, Biological Transport drug effects, Carcinogens pharmacology, Cyclic GMP metabolism, Dogs, Enzyme Inhibitors pharmacology, Female, Femoral Artery enzymology, Fluorescent Dyes, Free Radical Scavengers pharmacology, Fura-2, Male, Manganese pharmacology, Muscle Contraction drug effects, Muscle Contraction physiology, Muscle, Smooth, Vascular drug effects, Naphthalenes pharmacology, Protein Kinase C antagonists & inhibitors, Serotonin pharmacology, Staurosporine pharmacology, Tetradecanoylphorbol Acetate pharmacology, Vasoconstriction drug effects, Vasoconstriction physiology, Calcium metabolism, Hypoglycemic Agents pharmacology, Insulin pharmacology, Muscle, Smooth, Vascular enzymology, Protein Kinase C metabolism
- Abstract
Insulin acutely inhibits contraction of primary cultured vascular smooth muscle (VSM) cells from canine femoral artery by inhibiting contractile agonist-induced Ca2+ influx. Insulin also inhibits contraction at step(s) distal to intracellular Ca2+ concentration (Ca2+i) by stimulating cyclic guanosine monophosphate (GMP) production. We wished to see whether these effects of insulin are mediated by protein kinase C (PKC). Ca2+ influx was assessed by measuring the rate of fluorescence quenching of intracellular fura 2 by extracellular Mn2+. We found that 10 micromol/L serotonin (5-HT) stimulated Mn2+ influx 3-fold, and 1 nmol/L insulin inhibited the 5-HT-stimulated component of Mn2+ influx by 63% (P < .05), but insulin had no effect in the presence of 1 micromol/L staurosporine, an inhibitor of PKC. In the absence of insulin, preincubating cells with 0.1 micromol/L phorbol 12-myristate 13-acetate (PMA) for 5 min inhibited the 5-HT-stimulated component of Mn2+ influx by 69% (P < .05). Insulin inhibited cell contraction induced by raising Ca2+i to supraphysiologic levels with ionomycin by 75% (P < .05). We also noted that 10(-6) mol/L calphostin C, another PKC inhibitor, or 16-h preincubation with PMA completely blocked this effect of insulin. Finally, 10-min exposure to insulin or PMA increased cyclic GMP production in ionomycin-treated cells by 50% and 64%, respectively (both P < .05). We conclude that insulin inhibits VSM cell contraction by inhibiting 5-HT-stimulated Ca2+ influx and also at step(s) distal to Ca2+i by a PKC-dependent mechanism.
- Published
- 2000
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33. Insulin increases NO-stimulated guanylate cyclase activity in cultured VSMC while raising redox potential.
- Author
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Kahn AM, Allen JC, Seidel CL, Lichtenberg DS, Song T, and Zhang S
- Subjects
- Aerobiosis, Animals, Cells, Cultured, Dogs, Electrophoresis, Polyacrylamide Gel, Enzyme Inhibitors pharmacology, Female, Glycolysis drug effects, Immunoblotting, Lactic Acid metabolism, Male, Muscle, Smooth, Vascular cytology, Muscle, Smooth, Vascular drug effects, Nitric Oxide Donors pharmacology, Nitric Oxide Synthase antagonists & inhibitors, Nitric Oxide Synthase metabolism, Nitric Oxide Synthase Type II, Oxidation-Reduction, Penicillamine analogs & derivatives, Penicillamine pharmacology, Pyruvic Acid metabolism, S-Nitroso-N-Acetylpenicillamine, omega-N-Methylarginine pharmacology, Guanylate Cyclase metabolism, Insulin pharmacology, Muscle, Smooth, Vascular metabolism, Nitric Oxide pharmacology
- Abstract
Insulin acutely stimulates cyclic guanosine monophosphate (cGMP) production in primary confluent cultured vascular smooth muscle cells (VSMC) from canine femoral artery, but the mechanism is not known. These cells contain the inducible isoform of nitric oxide (NO) synthase (iNOS), and insulin-stimulated cGMP production in confluent cultured cells is blocked by the NOS inhibitor, N(G)-monomethyl-L-arginine (L-NMMA). In the present study, it is shown that iNOS is also present in freshly dispersed VSMC from this artery, indicating that iNOS expression in cultured VSMC is not an artifact of the culture process. Insulin did not stimulate NOS activity in primary confluent cultured cells because it did not affect citrulline or combined NO(-)(3)/NO(-)(2) production. To see whether insulin required the permissive presence of NO to stimulate cGMP production, iNOS and basal cGMP production were inhibited with L-NMMA, and the cells were incubated with or without 1 nM insulin and/or the NO donor, S-nitroso-N-acetyl-D,L-penicillamine (SNAP) at a concentration (0.1 microM) that restored cGMP production to the basal value. In the presence of L-NMMA, insulin no longer affected cGMP production but when insulin was added to L-NMMA plus SNAP, cGMP production was increased by 69% (P < 0.05 vs. L-NMMA plus SNAP). Insulin, which increases glucose uptake by these cells, increased the cell lactate content and the lactate-to-pyruvate ratio (LPR) by 81 and 97%, respectively (both P < 0.05), indicating that the hormone increased aerobic glycolysis and the redox potential. The effects of insulin on LPR and cGMP production were blocked by removing glucose or by adding 2-deoxyglucose to the incubation media and were duplicated by the reducing substrate, beta-hydroxybutyrate. We conclude that insulin does not acutely affect iNOS activity in these VSMC but it does augment cGMP production induced by the NO already present in the cell while increasing aerobic glycolysis and the cell redox potential.
- Published
- 2000
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34. Insulin inhibits migration of vascular smooth muscle cells with inducible nitric oxide synthase.
- Author
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Kahn AM, Allen JC, Seidel CL, and Zhang S
- Subjects
- Animals, Cell Movement physiology, Cells, Cultured, Cyclic GMP pharmacology, Dogs, Enzyme Inhibitors pharmacology, Female, Femoral Artery cytology, Guanylate Cyclase antagonists & inhibitors, Guanylate Cyclase metabolism, Lipopolysaccharides pharmacology, Male, Muscle, Smooth, Vascular drug effects, Muscle, Smooth, Vascular enzymology, Nitric Oxide metabolism, Nitric Oxide Synthase Type II, Oxadiazoles pharmacology, Quinoxalines pharmacology, Cell Movement drug effects, Hypoglycemic Agents pharmacology, Insulin pharmacology, Muscle, Smooth, Vascular cytology, Nitric Oxide Synthase metabolism
- Abstract
Vascular smooth muscle cell (VSMC) migration participates in atherosclerosis and arterial restenosis after balloon angioplasty. Because these processes are enhanced in insulin-resistant states, our goal was to determine whether insulin affects VSMC migration and, if so, how. The migration of primary cultured VSMCs from canine femoral artery was measured with the use of a wound migration assay and related to cGMP levels. Insulin (1 nmol/L) did not affect migration or cGMP production in control cells. When inducible nitric oxide synthase (iNOS) was induced by 24-hour preincubation with lipopolysaccharide and interleuken-1beta, basal migration decreased, cGMP production increased, and insulin inhibited migration by >90% and stimulated cGMP production by 3-fold. The nitric oxide synthase inhibitor N(G)-monomethyl-L-arginine blocked the affect of insulin on the migration of VSMCs with iNOS. 8-Bromo-cGMP inhibited VSMC migration in control cells, and 1-H-1[1,2,4]oxadiazolo-[4, 3a]quinoxolin-1-one, a selective inhibitor of guanylate cyclase, blocked the inhibition by insulin of migration of cells with iNOS. We conclude that insulin does not normally affect cGMP production or the migration of these VSMCs. However, after the induction of iNOS, insulin stimulates cGMP production and inhibits migration via an NOS-and a cGMP-dependent mechanism.
- Published
- 2000
- Full Text
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35. Insulin inhibits vascular smooth muscle contraction at a site distal to intracellular Ca2+ concentration.
- Author
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Kahn AM, Husid A, Odebunmi T, Allen JC, Seidel CL, and Song T
- Subjects
- Animals, Cells, Cultured, Cyclic GMP biosynthesis, Dogs, Female, Male, Muscle Contraction physiology, Muscle, Smooth, Vascular chemistry, Nitric Oxide Synthase physiology, Nitric Oxide Synthase Type II, Osmolar Concentration, Calcium metabolism, Insulin pharmacology, Intracellular Membranes metabolism, Muscle Contraction drug effects, Muscle, Smooth, Vascular drug effects, Muscle, Smooth, Vascular physiology
- Abstract
Several hypertensive states are associated with resistance to insulin-induced glucose disposal and insulin-induced vasodilation. Insulin can inhibit vascular smooth muscle (VSM) contraction at the level of the VSM cell, and resistance to insulin's inhibition of VSM cell contraction may be of pathophysiological importance. To understand the VSM cellular mechanisms by which insulin resistance leads to increased VSM contraction, we sought to determine how insulin inhibits contraction of normal VSM. It has been shown that insulin lowers the contractile agonist-stimulated intracellular Ca2+ (Ca2+i) transient in VSM cells. In this study, our goal was to see whether insulin inhibits VSM cell contraction at steps distal to Ca2+i and, if so, to determine whether the mechanism is dependent on nitric oxide synthase (NOS) and cGMP. Primary cultured VSM cells from canine femoral artery were bathed in a physiological concentration of extracellular Ca2+ and permeabilized to Ca2+ with a Ca2+ ionophore, either ionomycin or A-23187. The resultant increase in Ca2+i contracted individual cells, as measured by photomicroscopy. Preincubating cells with 1 nM insulin for 30 min did not affect basal Ca2+i or the ionomycin-induced increase in Ca2+i, as determined by fura 2 fluorescence measurements, but it did inhibit ionomycin- and A-23187-induced contractions by 47 and 51%, respectively (both P < 0.05). In the presence of 1.0 microM ionized Ca2+, ionomycin-induced contractions were inhibited by insulin in a dose-dependent manner. In the presence of ionomycin, insulin increased cGMP production by 43% (P < 0.05). 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (10 microM), a selective inhibitor of guanylate cyclase that blocked cGMP production in these cells, completely blocked the inhibition by insulin of ionomycin-induced contraction. It was found that the cells expressed the inducible isoform of NOS. NG-monomethyl-L-arginine or NG-nitro-L-arginine methyl ester (0.1 mM), inhibitors of NOS, did not affect ionomycin-induced contraction but prevented insulin from inhibiting contraction. We conclude that insulin stimulates cGMP production and inhibits VSM contraction in the presence of elevated Ca2+i. This inhibition by insulin of VSM contraction at sites where Ca2+i could not be rate limiting is dependent on NOS and cGMP.
- Published
- 1998
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36. Insulin acutely inhibits cultured vascular smooth muscle cell contraction by a nitric oxide synthase-dependent pathway.
- Author
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Kahn AM, Husid A, Allen JC, Seidel CL, and Song T
- Subjects
- Animals, Cells, Cultured, Citrulline biosynthesis, Cyclic GMP biosynthesis, Dogs, Female, Male, Manganese pharmacokinetics, Muscle, Smooth, Vascular cytology, Insulin pharmacology, Muscle, Smooth, Vascular drug effects, Muscle, Smooth, Vascular physiology, Nitric Oxide Synthase physiology, Vasoconstriction physiology
- Abstract
Insulin acutely decreases contractile agonist-induced Ca2+ influx and contraction in endothelium-free cultured vascular smooth muscle (VSM) cells, but the mechanism is not known. Since it has been reported that insulin-induced vasodilation in humans is linked to nitric oxide synthase activity, we wished to determine whether insulin inhibits Ca2+ influx and contraction of cultured vascular smooth muscle cells by a nitric oxide synthase-dependent pathway. Primary cultures of endothelial cell-free VSM cells from canine femoral artery were preincubated with and without 1 nmol/L insulin for 30 minutes, and the 5-minute production of cGMP was measured. Insulin alone did not affect cGMP production, but in the presence of 10(-5) mol/L serotonin insulin stimulated cGMP production by 60%. N(G)-monomethyl-L-arginine (0.1 mmol/L), an inhibitor of nitric oxide synthase, inhibited the conversion of arginine to citrulline by these cells, blocked insulin-stimulated cGMP production, and blocked the inhibition by insulin of 5-hydroxytryptamine (5-HT)-stimulated Mn+2 (a Ca2+ surrogate) influx and contraction. Insulin did not affect contraction of VSM cells grown under conditions designed to deplete the cells of tetrahydrobiopterin, an essential cofactor of nitric oxide synthase. These studies demonstrate that insulin acutely inhibits 5-HT-stimulated Ca2+ influx and contraction of endothelium-free cultured VSM cells by a nitric oxide synthase-dependent mechanism.
- Published
- 1997
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37. Cellular heterogeneity of the vascular tunica media. Implications for vessel wall repair.
- Author
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Seidel CL
- Subjects
- Animals, Humans, Muscle, Smooth, Vascular cytology, Muscle, Smooth, Vascular physiology, Tunica Media cytology
- Published
- 1997
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38. The A10 cell line: a model for neonatal, neointimal, or differentiated vascular smooth muscle cells?
- Author
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Rao RS, Miano JM, Olson EN, and Seidel CL
- Subjects
- Actins analysis, Animals, Animals, Newborn, Aorta, Thoracic, Blotting, Northern, Blotting, Western, Calcium-Binding Proteins analysis, Cell Differentiation, Cell Movement, Desmin analysis, Electrophoresis, Polyacrylamide Gel, Fluorescent Antibody Technique, Microfilament Proteins, Models, Biological, Myosin Heavy Chains analysis, Myosins analysis, Platelet-Derived Growth Factor analysis, Rats, Tropoelastin analysis, Tunica Intima cytology, Vimentin analysis, Calponins, Cell Line, Muscle, Smooth, Vascular cytology
- Abstract
Objectives: The A10 cell line was derived from the thoracic aorta of embryonic rat and is a commonly used model of vascular smooth muscle cells (VSMC). Despite its wide use this cell line has not been well characterized. This is especially important in light of recent evidence of phenotypically distinct cell populations isolated from rat vascular tissue. Therefore, the present study was undertaken to confirm the VSMC nature of A10 cells and to investigate whether these cells particularly resemble adult, neonatal, or neointimal rat VSMC., Methods: A variety of defining characteristics were used that included immunofluorescent analysis for smooth muscle alpha-actin, smooth and non-muscle myosin heavy chains, desmin and vimentin; Western analysis for smooth muscle and non-muscle myosin heavy chains; mRNA analysis for smooth muscle myosin heavy chain, calponin, SM22 alpha, tropoelastin and PDGF-B peptide; and functional assays of cell migration, proliferation and agonist induced intracellular Ca transients., Results: A10 cells expressed smooth muscle alpha-actin, SM22 alpha, smooth muscle calponin and vimentin, characteristic of in vivo rat VSMCs; however they also resembled de-differentiated smooth muscle cells in that they expressed non-muscle myosin rather than smooth muscle myosin heavy chain. A10 cells resembled cultured rat neonatal smooth muscle cells ("pup cells") in that they had an epithelioid shape and lacked functional PDGF-alpha receptors: however they did not express PDGF-B mRNA or proliferate in low serum containing medium as do neonatal cells. A10 cells had several characteristics in common with neointimal cells including the expression of alpha-actin, vimentin, and non-muscle myosin and the lack of expression of PDGF-B mRNA as well as the ability to migrate in response to PDGF-BB., Conclusion: In conclusion, A10 cells are nondifferentiated VSMC that differ from neonatal but bear significant resemblance to neointimal cells.
- Published
- 1997
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39. Migratory abilities of different vascular cells from the tunica media of canine vessels.
- Author
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Seidel CL, Helgason T, Allen JC, and Wilson C
- Subjects
- Animals, Carotid Arteries, Cell Movement drug effects, Cells, Cultured, Cytoskeleton ultrastructure, Dogs, Endothelin-1 pharmacology, Endothelin-3 pharmacology, Myosins metabolism, Platelet-Derived Growth Factor pharmacology, Saphenous Vein, Tunica Media cytology
- Abstract
In response to injury, vascular smooth muscle cells (VSMC) are thought to migrate toward the area of damage, where they participate in the reparative process. We have recently identified and isolated two distinct cell types (VSMC and type 2 cells) from the tunica media of canine carotid artery and saphenous vein. The purpose of these experiments was to determine whether both cell types were able to migrate in response to a variety of chemoattractants. A multiwell Boyden chamber and a wound migration assay were used to assess the migratory ability of these cells in vitro. The results indicated that VSMC did not exhibit directed migration in response to either 10% fetal bovine serum or platelet-derived growth factor (PDGF)-AB. In contrast, type 2 cells migrated to serum, PDGF-AB, and PDGF-BB but not to PDGF-AA, endothelin (ET)-1, or ET-3. No difference in migratory ability was detected between type 2 cells isolated from carotid arteries or saphenous veins. It is concluded that the migratory ability of cells within the tunica media of vessels from adult animals are not equal, suggesting that only selected cells may participate in vascular wall repair.
- Published
- 1997
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40. Insulin-stimulated glucose transport inhibits Ca2+ influx and contraction in vascular smooth muscle.
- Author
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Kahn AM, Lichtenberg RA, Allen JC, Seidel CL, and Song T
- Subjects
- Animals, Biological Transport, Cells, Cultured, Dogs, Female, Male, Manganese metabolism, Muscle, Smooth, Vascular physiology, Phlorhizin pharmacology, Serotonin pharmacology, Calcium metabolism, Glucose metabolism, Insulin pharmacology, Muscle, Smooth, Vascular drug effects, Vasoconstriction drug effects
- Abstract
Background: Insulin attenuates serotonin-induced Ca2+ influx, the intracellular Ca2+ transient, and contraction of cultured vascular smooth muscle cells from dog femoral artery. These studies were designed to test whether insulin-induced glucose transport was an early event leading to the inhibitory effects of insulin on Ca2+ influx, intracellular Ca2+ concentration, and contraction in these cells., Methods and Results: Insulin 1 nmol/L stimulated the 30-minute uptake of [3H]2-deoxyglucose in these cells via a phloridzin-inhibitable mechanism. Contraction of individual cells was measured by photomicroscopy, intracellular Ca2+ concentration was monitored by measuring fura 2 fluorescence by use of Ca(2+)-sensitive excitation wavelengths, and Ca2+ influx was estimated by the rate of Mn2+ quenching of intracellular fura 2 fluorescence when excited at a Ca(2+)-insensitive wave-length. In the presence of 5 mmol/L glucose, preincubation of cells for 30 minutes with 1 nmol/L insulin inhibited 10(-5) mol/L serotonin-induced contraction of individual cells by 62% (P < .01) and decreased the serotonin-stimulated component of Mn2+ influx by 78% (P < .05). Removing glucose from the preincubation medium or adding 1 mmol/L phloridzin completely eliminated these effects of insulin. Insulin lowered the serotonin-induced intracellular Ca2+ peak by 37% (P < .05), and phloridzin blocked this effect of insulin. When glucose uptake was increased to the insulin-stimulated level by preincubation of the cells for 30 minutes with 25 mmol/L glucose in the absence of insulin, serotonin failed to stimulate Mn2+ influx, the serotonin-induced Ca2+ peak was decreased by 46% (P < .05), serotonin-induced contraction was inhibited by 60% (P < .01), and addition of insulin did not further inhibit contraction., Conclusions: Since the effects of insulin on serotonin-stimulated Ca2+ transport, intracellular Ca2+ concentration, and contraction were dependent on glucose transport and were duplicated when glucose transport was stimulated by high extracellular glucose concentration rather than insulin per se, it is concluded that insulin-stimulated glucose transport is an early event that leads to decreased Ca2+ influx and contraction in vascular smooth muscle.
- Published
- 1995
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41. Insulin inhibits serotonin-induced Ca2+ influx in vascular smooth muscle.
- Author
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Kahn AM, Allen JC, Seidel CL, and Song T
- Subjects
- Animals, Cell Membrane Permeability drug effects, Cells, Cultured, Dogs, Female, Fura-2, Intracellular Membranes metabolism, Male, Manganese metabolism, Muscle, Smooth, Vascular cytology, Saponins pharmacology, Sarcolemma metabolism, Calcium metabolism, Calcium Channel Blockers pharmacology, Insulin pharmacology, Muscle, Smooth, Vascular metabolism, Serotonin pharmacology
- Abstract
Background: Insulin in physiological concentrations attenuates the agonist-induced intracellular Ca2+ ([Ca2+]i) transient and inhibits contraction in individual nonproliferated cultured canine femoral artery vascular smooth muscle cells (VSMCs). In the present study, we wished to define the effects of insulin on individual components of Ca2+ transport in vascular smooth muscle., Methods and Results: Insulin (40 microU/mL) attenuated the 5-hydroxytryptamine (5-HT, serotonin; 10(-5) mol/L)-induced [Ca2+]i transient (measured by fura 2 fluorescence) in primary confluent canine femoral artery VSMCs in the presence of extracellular Ca2+. In Ca(2+)-free media, the 5-HT-induced [Ca2+]i transient was reduced by 42% and was not affected by insulin. This finding suggested that insulin inhibits 5-HT-induced Ca2+ influx but does not affect sarcolemmal Ca2+ efflux or Ca2+ release from intracellular stores. In support of those conclusions, we found that insulin inhibited the 5-HT-induced component of Mn2+ (a Ca2+ surrogate) influx (measured by fura 2 fluorescence quenching at the Ca2+ isosbestic excitation wavelength). In addition, 5-HT stimulated the rates of 45Ca2+ efflux from intact cells (a measure of sarcolemmal Ca2+ efflux) and from saponin-permeabilized cells (a measure of Ca2+ release from intracellular stores), but insulin did not affect these rates of 45Ca2+ efflux., Conclusions: We conclude that a physiological insulin concentration attenuates the 5-HT-induced [Ca2+]i transient in confluent primary cultured canine femoral artery VSMCs by inhibiting the 5-HT-induced component of Ca2+ influx but not by affecting sarcolemmal Ca2+ efflux or Ca2+ release from intracellular stores.
- Published
- 1994
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42. Insulin reduces contraction and intracellular calcium concentration in vascular smooth muscle.
- Author
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Kahn AM, Seidel CL, Allen JC, O'Neil RG, Shelat H, and Song T
- Subjects
- Angiotensin II pharmacology, Animals, Cells, Cultured, Dogs, Dose-Response Relationship, Drug, Female, Femoral Artery metabolism, Femoral Artery physiology, In Vitro Techniques, Kinetics, Male, Muscle, Smooth, Vascular metabolism, Muscle, Smooth, Vascular physiology, Ouabain pharmacology, Potassium pharmacology, Serotonin pharmacology, Vasodilation drug effects, Verapamil pharmacology, Calcium metabolism, Femoral Artery drug effects, Insulin pharmacology, Muscle Contraction drug effects, Muscle, Smooth, Vascular drug effects
- Abstract
Resistance to insulin-induced glucose disposal is associated with hypertension, in accord with recent reports that insulin-induced vasodilation is impaired in men with resistance to insulin-induced glucose disposal. Nevertheless, the mechanism of insulin-induced vasodilation is not known. We wished to determine whether a physiological concentration of insulin inhibits agonist-induced contraction at the level of the individual vascular smooth muscle cell, and if so, how. Dispersed vascular smooth muscle cells from dog femoral artery were grown on collagen gels for 4 to 8 days. Contraction and intracellular Ca2+ concentration of individual cells were measured by photomicroscopy and fura 2 epifluorescence microscopy, respectively. Serotonin and angiotensin II contracted cells in a dose-dependent manner. Preincubation of cells for 20 minutes (short-term) or 7 days (long-term) with insulin (40 microU/mL) inhibited serotonin- and angiotensin II-induced contractions by approximately 50%. Insulin (10 microU/mL) acutely inhibited serotonin-induced contraction by 34%. The maximal effect of high extracellular K(+)-induced contraction was not affected by short-term insulin exposure, but the ED50 for extracellular K(+)-induced contraction was increased from 7.6 +/- 2.5 to 16.0 +/- 3.9 mmol/L (P < .05). Short-term insulin exposure also attenuated the peak rise of the serotonin-induced intracellular Ca2+ transient and increased the rate constant for intracellular Ca2+ decline. Verapamil and ouabain completely blocked the attenuation of agonist-induced contraction by short-term insulin exposure, indicating the importance of voltage-operated Ca2+ channels and the Na(+)-K+ pump for this effect.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1993
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43. Relationship between functional Na+ pumps and mitogenesis in cultured coronary artery smooth muscle cells.
- Author
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Feltes TF, Seidel CL, Dennison DK, Amick S, and Allen JC
- Subjects
- Animals, Cations metabolism, Cell Count, Cells, Cultured, Coronary Vessels cytology, Dogs, Female, Flow Cytometry, Male, Mitogens blood, Muscle, Smooth, Vascular cytology, Myosins metabolism, Ouabain metabolism, Sodium-Potassium-Exchanging ATPase drug effects, Coronary Vessels metabolism, Mitogens pharmacology, Muscle, Smooth, Vascular metabolism, Sodium-Potassium-Exchanging ATPase physiology
- Abstract
An increase in functional sarcolemmal Na(+)-K(+)-ATPase (Na+ pump) precedes proliferation in vascular smooth muscle cells (VSMCs) seeded in 10% fetal bovine serum (FBS), but its role in mitogenesis is unresolved. Enzymatically dispersed canine coronary artery VSMCs were seeded in FBS and studied through confluence. Before a shift in cell cycle (G1-->S, G2 + M) and appearance of the nonmuscle isoform of myosin (MHCnm), intracellular Na+ content (Na+i) and cell volume (CV) increased (day 0 through day 3). Na+ pump number ([3H]-ouabain binding) increased at day 4 followed by a decrease in Na+i and CV. When Na+ pumps were inhibited by the addition of ouabain to FBS, VSMCs were arrested in G1, and MHCnm was not upregulated. Na+i increased similarly to that in FBS but failed to correct to day 0 levels. Withdrawal of ouabain at day 4 in culture led to an increase in Na+ pump number, a decrease in Na+i, entry of cells into S and G2 + M, and upregulation of MHCnm. These data suggest that Na+i, phenotypic modulation, and entry of cells into the cell cycle are temporally related, with Na+ pump-mediated correction of increased Na+i as a key event in the VSMC mitogenic process.
- Published
- 1993
- Full Text
- View/download PDF
44. Effects of serotonin on intracellular pH and contraction in vascular smooth muscle.
- Author
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Kahn AM, Bishara M, Cragoe EJ Jr, Allen JC, Seidel CL, Navran SS, O'Neil RG, McCarty NA, and Shelat H
- Subjects
- 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid, 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid analogs & derivatives, 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid pharmacology, Amiloride analogs & derivatives, Amiloride pharmacology, Animals, Bicarbonates metabolism, Cells, Cultured, Chlorides metabolism, Dogs, Female, HEPES pharmacology, Male, Muscle, Smooth, Vascular metabolism, Sodium metabolism, Stimulation, Chemical, Hydrogen-Ion Concentration, Muscle Contraction drug effects, Muscle, Smooth, Vascular cytology, Muscle, Smooth, Vascular drug effects, Serotonin pharmacology
- Abstract
Serotonin (5-HT) and other contractile agonists stimulate Na(+)-H+ exchange in vascular smooth muscle. Since intracellular alkalinization, per se, stimulates contraction, we tested whether 5-HT-induced contraction was associated with an increased pHi. In HCO3(-)-free buffer (pHo 7.4), 5-HT (10(-5) M) increased pHi, as measured by 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein fluorescence, from 7.10 +/- 0.03 to 7.34 +/- 0.03 (p < 0.01) in primary cultures of canine femoral artery vascular smooth muscle cells grown to confluence in the presence of 10% fetal calf serum. In HCO3- buffer (24 mM, pHo 7.4), resting pHi was 7.26 +/- 0.04 (p < 0.01 versus HCO3(-)-free buffer) but was not altered by 5-HT. In both types of buffer, 5-HT stimulated 5-(N-ethyl-N-isopropyl)amiloride-sensitive 22Na+ uptake (Na(+)-H+ exchange). In HCO3- buffer and in Na(+)- and HCO3(-)-free buffer, 5-HT increased 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid-sensitive 36Cl- uptake, suggesting that 5-HT stimulated Na(+)-independent Cl(-)-HCO3- and Cl(-)-Cl- exchange activities, respectively. Individual vascular smooth muscle cells were then cultured on rat tail tendon collagen gels in the presence of 0.5% fetal calf serum, and cell length and pHi were measured by video and epifluorescence microscopy. 5-HT contracted cells in a dose-dependent, reversible, and ketanserin-inhibitable manner. These cells, like cells grown in 10% fetal calf serum, exhibited Na(+)-H+ and Na(+)-independent Cl(-)-HCO3- exchange. In HCO3- buffer, 5-HT contracted cells without an associated change in pHi. We concluded the following: 1) 5-HT stimulated both Na(+)-H+ and Na(+)-independent Cl(-)-HCO3- exchange activities in cultured vascular smooth muscle cells in parallel. 2) As a result of enhanced H+ and HCO3- efflux, pHi was not altered. 3) In the presence of HCO3-, 5-HT-induced contraction was not associated with a change in pHi.
- Published
- 1992
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45. Effects of pHi on Na(+)-H+, Na(+)-dependent, and Na(+)-independent C1(-)-HCO3-exchangers in vascular smooth muscle.
- Author
-
Kahn AM, Cragoe EJ Jr, Allen JC, Seidel CL, and Shelat H
- Subjects
- 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid, 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid analogs & derivatives, 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid pharmacology, Amiloride analogs & derivatives, Amiloride pharmacology, Animals, Cells, Cultured, Chloride-Bicarbonate Antiporters, Dogs, Female, Fluoresceins, Hydrogen-Ion Concentration, Male, Muscle, Smooth, Vascular cytology, Sodium-Hydrogen Exchangers, Carrier Proteins metabolism, Muscle, Smooth, Vascular metabolism, Sodium pharmacology
- Abstract
The mechanisms that control intracellular pH (pHi) in vascular smooth muscle are not fully understood. We reported that pHi in primary cultured vascular smooth muscle cells from canine femoral artery is 7.26, a value maintained via HCO3- influx by the Na(+)-dependent C1(-)-HCO3-exchanger but not via H+ efflux by the Na(+)-H+ exchanger [A. M. Kahn, E. J. Cragoe, Jr., J. C. Allen, R. D. Halligan, and H. Shelat. Am. J. Physiol 259 (Cell Physiol. 28): C134-C143, 1990]. To explain these findings, in the present study, we determined the pHi activity profile of these two transport systems. Although both were active at acidic pHi, Na(+)-H+ exchange activity was very low at and above pHi 7.0, while Na(+)-dependent C1(-)-HCO3-exchange activity maintained near-maximal activity up to pHi 7.26 but fell to undetectable levels by pHi 7.4. A Na(+)-independent C1(-)-HCO3-exchanger was present, which mediated HCO3-efflux after an acute alkaline load. The activity of this system was negligible at pHi 7.2 and was stimulated at alkaline pHi. In conclusion, the pHi of these vascular smooth muscle cells at rest is maintained via HCO3-influx by the Na(+)-dependent C1(-)-HCO3-exchanger. After acute acidic or alkaline loads, correction of pHi is mediated by activation of the normally quiescent Na(+)-H+ and Na(+)-independent C1(-)-HCO3-exchangers, respectively. All three acid-base transport systems have pHi set points that protect the cell from overcorrecting pHi after a disturbance in either direction.
- Published
- 1991
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46. Control and function of alterations in contractile protein isoform expression in vascular smooth muscle.
- Author
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Seidel CL, Rickman D, Steuckrath H, Allen JC, and Kahn AM
- Subjects
- Animals, Cells, Cultured, Dogs, Electrophoresis, Polyacrylamide Gel, Isomerism, Muscle Contraction physiology, Muscle, Smooth, Vascular cytology, Muscle, Smooth, Vascular metabolism, Myosins biosynthesis, Potassium Chloride pharmacology, Saphenous Vein metabolism, Saphenous Vein transplantation, Serotonin pharmacology, Muscle, Smooth, Vascular physiology, Myosins physiology
- Published
- 1991
- Full Text
- View/download PDF
47. Serotonin-induced Na+/K+ pump stimulation in vascular smooth muscle cells. Evidence for coupling to multiple receptor mechanisms.
- Author
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Navran SS, Allain G, Garcia HF, Allen JC, and Seidel CL
- Subjects
- Animals, Biological Transport, Active, Dogs, Femoral Artery cytology, Femoral Artery metabolism, Muscle, Smooth, Vascular cytology, Muscle, Smooth, Vascular drug effects, Phosphatidylinositols metabolism, Receptors, Serotonin classification, Receptors, Serotonin metabolism, Second Messenger Systems drug effects, Second Messenger Systems physiology, Serotonin administration & dosage, Stimulation, Chemical, Muscle, Smooth, Vascular metabolism, Potassium metabolism, Serotonin pharmacology, Sodium metabolism
- Abstract
Exposure of cultured canine femoral artery vascular smooth muscle cells to serotonin (5-HT) caused a 3.6-fold stimulation of ouabain-sensitive 86Rb uptake. The 5-HT2 receptor antagonist, ketanserin, partly blocked the 5-HT-mediated Na+/K+ pump stimulation and the 5-HT1/5-HT2 receptor antagonist, methiothepin, completely blocked the response, suggesting that both 5-HT1 and 5-HT2 receptors play a role in the 5-HT-mediated Na+/K+ pump activation. Second messengers generated by 5-HT2 receptor-mediated phosphoinositide hydrolysis, Ins(1,4,5)P3 and diacylglycerol were implicated in the stimulatory action of 5-HT on the vascular Na+/K+ pump. Like some other contractile agonists, 5-HT activated a Na+ influx pathway which caused Na+/K+ pump stimulation by increasing the rate-limiting substrate. The maximum stimulation of Na+ influx by 5-HT was 2.5-fold. The 5-HT-stimulated Na+ influx was totally blocked by methiothepin but only 29% inhibited by ketanserin, indicating that most of the Na+ influx was mediated by the 5-HT1 receptor. The 5-HT-stimulated Na+ influx was substantially inhibited by 50 microM dimethylamiloride, suggesting that the Na+ influx pathway stimulated by 5-HT was Na+/H+ exchange. BAPTA/AM 1,2-[bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, tetra (acetoxymethyl) ester], an intracellular Ca++ chelator, partly blocked 5-HT-stimulated Na+ influx and ouabain-sensitive 86Rb uptake, suggesting that Ca++ is an important mediator of these responses. These data suggest that: 1) 5-HT, in addition to its well known activity as a contractile agonist, can stimulate the electrogenic Na+/K+ pump which, in theory, would tend to oppose contraction.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1991
48. Focal toxicity of oxysterols in vascular smooth muscle cell culture. A model of the atherosclerotic core region.
- Author
-
Guyton JR, Black BL, and Seidel CL
- Subjects
- Animals, Aorta analysis, Aorta cytology, Aorta drug effects, Arteriosclerosis pathology, Cell Movement drug effects, Cell Survival drug effects, Cells, Cultured, Chemotaxis drug effects, Cholestanols analysis, DNA biosynthesis, DNA drug effects, Disease Models, Animal, Dogs, Hydroxycholesterols analysis, Hypolipidemic Agents analysis, Microscopy, Phase-Contrast, Muscle, Smooth, Vascular analysis, Muscle, Smooth, Vascular drug effects, Cholestanols toxicity, Hydroxycholesterols toxicity, Hypolipidemic Agents toxicity, Muscle, Smooth, Vascular cytology
- Abstract
Cell necrosis and reactive cellular processes in and near the atherosclerotic core region might result from short-range interactions with toxic lipids. To model these interactions in cell culture, focal crystalline deposits of cholestane-3 beta,5 alpha,6 beta-triol, 25-OH cholesterol, and cholesterol were overlaid by a collagen gel, on which canine aortic smooth muscle cells were seeded. Oxysterols, but not cholesterol, caused focally decreased plating efficiency and cell death, leading to the formation of a persistent circular gap in the cell culture. Cholestanetriol was largely removed from the culture dishes over 3 to 4 weeks, whereas cholesterol and 25-OH cholesterol were largely retained. Smooth muscle cells were motile even in proximity to oxysterol crystals, with occasional suicidal migration toward the crystals. Chemoattraction, however, could not be demonstrated. Despite toxicity, cholestanetriol did not appear to alter the fraction of cells exhibiting 3H-thymidine uptake, even in areas close to the crystals. Thus, oxysterols may be toxic to some cells, without causing major impairment of the migration and proliferation of nearby cells. This would allow the simultaneous occurrence of cell death and proliferation evident in atherosclerosis.
- Published
- 1990
49. Hydralazine: effect on contraction mechanics of WKY and SHR rat heart muscle.
- Author
-
Michael LH and Seidel CL
- Subjects
- Animals, Blood Pressure drug effects, Isoproterenol pharmacology, Male, Muscle Relaxation drug effects, Rats, Hydralazine pharmacology, Myocardial Contraction drug effects, Papillary Muscles drug effects
- Abstract
Chronic hydralazine treatment (2 weeks) in 22-week-old normotensive (WKY) and spontaneously hypertensive rats (SHR) significantly lowered the systolic blood pressure in both groups. Left ventricular papillary muscles from nontreated and treated WKY and SHR were placed in an isometric myography, and contractile indices monitored. Nontreated WKY and SHR were not statistically different comparing: tension, maximum contraction and relaxation rates, time to maximum tension, total contraction time, or passive and active length-tension curves. Hydralazine-treated WKY and SHR had significantly reduced tension and maximum rates of tension development and relaxation; passive length-tension characteristics were not altered. Stressing the papillary muscles with increased frequency of electrical stimulation (0.1-2 Hz) did not differentiate the various groups. Significant (p less than 0.05) alteration with isoproterenol (10(-9)-10(-5) M) occurred with the hydralazine-treated WKY, which responded with a greater increase in relaxation rate than the hydralazine-treated SHR. It is suggested that the clinically very useful drug, hydralazine, causes a distinct contractile state alteration in rat myocardium after treatment sufficient to lower SHR blood pressure to a normal range.
- Published
- 1981
- Full Text
- View/download PDF
50. Skeletal muscle protein and amino acid metabolism in hereditary mouse muscular dystrophy. Accelerated protein turnover and increased alanine and glutamine formation and release.
- Author
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Garber AJ, Schwartz RJ, Seidel CL, Silvers A, and Entman ML
- Subjects
- Actins biosynthesis, Adenosine Triphosphate metabolism, Alanine metabolism, Animals, Aspartic Acid metabolism, Glutamates metabolism, Glutamine metabolism, Kinetics, Mice, Mice, Inbred C57BL, Mice, Inbred Strains, Phosphocreatine metabolism, Amino Acids metabolism, Muscle Proteins metabolism, Muscles metabolism, Muscular Dystrophy, Animal metabolism
- Abstract
Interactins between skeletal muscle protein and amino acid metabolism were investigated using C57BL and 129ReJ mice with hereditary muscular dystrophy. On incubation, hind limb muscle preparations from dystrophic mice released large quantities of amino acids, particularly alanine and glutamine which were increased 70% and 40% compared to muscles from carrier or control mice. The increased alanine release did not result from altered alanine oxidation to CO2 or reincorporation into protein. Alanine and glutamine formation from added amino acids were equal with dystrophic and control muscles. Incorporation in vitro of leucine, alanine, and glutamate into proteins of dystrophic muscle was 3- to 7-fold greater than control muscle, and the incorporation in vivo of [3H]- or [14C]arginine into muscle proteins was greater in extent and earlier in time with dystrophic as compared to control muscle. Proteins were also labeled in vivo using [guanido-14C]arginine. On incubation of these muscles in vitro, a 100% greater loss of label from protein was observed with dystrophic as compared to control preparations, and the appearance of label in the media was correspondingly increased. Sodium dodecyl sulfate-gel electrophoresis of dystrophic skeletal muscle showed numerous protein bands to be reduced in density, but autoradiographic studies demonstrated that these same bands were more highly labeled in vitro by [35S]methionine in dystrophic than in control muscle. Although insulin stimulation of glucose uptake was markedly blunted in dystrophic muscle, insulin inhibited alanine and glutamine release equally from both control and dystrophic muscle. These data indicate that alanine and glutamine formation and release are increased in hereditary mouse muscular dystrophy. An accelerated degradation and an increased resynthesis of many muscle proteins were also observed in dystrophic compared to control animals. This increased proteolysis may account for the increased alanine and glutamine formation in dystrophic muscle.
- Published
- 1980
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