18 results on '"Oral, E"'
Search Results
2. Polymeric joint bearing surfaces for total joint replacements
- Author
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Oral, E., primary
- Published
- 2011
- Full Text
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3. Ultrahigh Molecular Weight Polyethylene Total Joint Implants*
- Author
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Oral, E., primary, Kurtz, S.M., additional, and Muratoglu, O.K., additional
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- 2011
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4. Neural correlates of mental state decoding and mental state reasoning in schizophrenia.
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Demirlek C, Karakılıç M, Sarıkaya E, Bayrakçı A, Verim B, Gülyüksel F, Yalınçetin B, Oral E, Gelal F, Zorlu N, and Bora E
- Subjects
- Humans, Brain diagnostic imaging, Brain pathology, Diffusion Tensor Imaging methods, Magnetic Resonance Imaging methods, Schizophrenia diagnostic imaging, Schizophrenia pathology, White Matter diagnostic imaging, White Matter pathology
- Abstract
Theory of mind skills are disrupted in schizophrenia. However, various theory of mind tasks measure different neurocognitive domains. This multimodal neuroimaging study aimed to investigate the neuroanatomical correlates of mental state decoding and reasoning components of theory of mind in schizophrenia and healthy controls (HCs) using T1-weighted and diffusion-weighted (DTI) magnetic resonance imaging (MRI). Sixty-two patients with schizophrenia and 34 HCs were included. The Reading the Mind in the Eyes (RMET) and Hinting tests were used to evaluate mental state decoding and reasoning, respectively. Correlations between social cognition and cortical parameters (thickness, volume, surface area), or DTI scalars (fractional anisotropy, axial diffusivity, radial diffusivity) were cluster-based corrected for multiple comparisons. In schizophrenia, RMET scores showed positive correlations in 3 clusters, including left insula thickness, right superior-temporal thickness, left superior-temporal-sulcus volume, and DTI analysis revealed that fractional anisotropy showed positive correlations in 3 clusters, including right inferior-fronto-occipital fasciculus, left forceps-major, left inferior-fronto-occipital fasciculus. In schizophrenia, Hinting test scores showed positive correlations in 3 clusters in T1-weighted MRI, including left superior-temporal-sulcus volume, left superior-temporal-sulcus surface area, left pars-orbitalis volume. In conclusion, this study provided evidence for the involvement of particular cortical regions and white matter tracts in mental state decoding and reasoning., Competing Interests: Declaration of Competing Interest Authors declare no conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)
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- 2023
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5. Proceedings of the annual meeting of the European Consortium of Lipodystrophies (ECLip) Cambridge, UK, 7-8 April 2022.
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Mosbah H, Akinci B, Araújo-Vilar D, Carrion Tudela J, Ceccarini G, Collas P, Farooqi IS, Fernández-Pombo A, Jéru I, Karpe F, Krause K, Maffei M, Miehle K, Oral E, Perez de Tudela N, Prieur X, Rochford J, Sanders R, Santini F, Savage DB, von Schnurbein J, Semple R, Stears A, Sorkina E, Vantyghem MC, Vatier C, Vidal-Puig A, Vigouroux C, and Wabitsch M
- Subjects
- Humans, Adipose Tissue, Syndrome, United Kingdom, Lipodystrophy therapy, Lipodystrophy genetics
- Abstract
Lipodystrophy syndromes are rare diseases with defects in the development or maintenance of adipose tissue, frequently leading to severe metabolic complications. They may be genetic or acquired, with variable clinical forms, and are largely underdiagnosed. The European Consortium of Lipodystrophies, ECLip, is a fully functional non-profit network of European centers of excellence working in the field of lipodystrophies. It provides a favorable environment to promote large Europe-wide and international collaborations to increase the basic scientific understanding and clinical management of these diseases. It works with patient advocacy groups to increase public awareness. The network also promotes a European Patient Registry of lipodystrophies, as a collaborative research platform for consortium members. The annual congress organized gives an update of the findings of network research groups, highlighting clinical and fundamental aspects. The talks presented during the meeting in Cambridge, UK, in 2022 are summarized in these minutes., (Copyright © 2022 Elsevier Masson SAS. All rights reserved.)
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- 2022
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6. Comparison of Isolated Sciatic Nerve and Sacral Nerve Root Endometriosis: A Review of the Literature.
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Kale A, Baydili KNS, Keles E, Gundogdu E, Usta T, and Oral E
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- Female, Humans, Sciatic Nerve surgery, Spinal Nerve Roots surgery, Endometriosis complications, Endometriosis pathology, Endometriosis surgery, Laparoscopy methods, Peroneal Neuropathies complications, Peroneal Neuropathies pathology, Peroneal Neuropathies surgery
- Abstract
Objective: This review aimed to compare isolated sciatic and sacral nerve root endometriosis in terms of anatomic distribution, patients' symptoms and history, diagnostics, treatments, and outcomes., Data Source: We searched PubMed, MEDLINE, Web of Science, and Embase from inception to October 2021 using a combination of keywords including "sciatic nerve endometriosis," "sacral nerve root endometriosis," and associated Medical Subject Headings. Relevant publications and references were also checked for further articles., Methods of Study Selection: Two independent researchers performed the study selection. We included all original research articles, case reports, and case series in English that reported on the isolated sciatic nerve and sacral nerve root endometriosis., Tabulation, Integration, and Results: The initial search identified 92 articles, and 40 articles, mostly case reports and case series, were included. The review included 362 patients: with 256 and 106 patients in the sacral and the sciatic groups, respectively. In both groups, most patients had right-sided endometriosis. In the sciatic group, most of the patients presented with foot drop, leg motor weakness, and sciatic dermatome hypoesthesia. The frequencies of all these symptoms were significantly higher in the sciatic group (all p <.001). By contrast, in the sacral group, most of patients presented with pudendal neuralgia (p <.001). Intraoperative, early, late, and 1-year postoperative complications did not differ significantly between the 2 groups., Conclusion: This study indicated that isolated sciatic and sacral nerve root endometrioses were more common on the right side. Laparoscopic surgery was more commonly performed over traditional open or transgluteal surgery techniques. Sacral nerve root endometriosis is often accompanied by deep infiltrating endometriosis. Magnetic resonance imaging and myelography may be useful diagnostic tools in the preoperative workup. There was usually no significant improvement after surgery in cases of isolated sciatic nerve endometriosis presenting with foot drop., (Copyright © 2022 AAGL. Published by Elsevier Inc. All rights reserved.)
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- 2022
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7. Thoracic Endometriosis: A Review Comparing 480 Patients Based on Catamenial and Noncatamenial Symptoms.
- Author
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Topbas Selcuki NF, Yilmaz S, Kaya C, Usta T, Kale A, and Oral E
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- Diaphragm, Female, Humans, Menstruation, Thorax, Endometriosis diagnosis, Endometriosis surgery, Pneumothorax
- Abstract
Objective: This review aimed to categorize thoracic endometriosis syndrome (TES) according to whether the presenting symptoms were catamenial and to evaluate whether such a categorization enables a better management strategy., Data Sources: An electronic search was conducted using the PubMed/Medline database., Methods of Study Selection: The following keywords were used in combination with the Boolean operators AND OR: "thoracic endometriosis syndrome," "thoracic endometriosis," "diaphragm endometriosis," and "catamenial pneumothorax.", Tabulation, Integration, and Results: The initial search yielded 445 articles. Articles in non-English languages, those whose full texts were unavailable, and those that did not present the symptomatology clearly were further excluded. After these exclusions, the review included 240 articles and 480 patients: 61 patients in the noncatamenial group and 419 patients in the catamenial group. The groups differed significantly in presenting symptoms, surgical treatment techniques, and observed localization of endometriotic loci (p <.05)., Conclusion: This review points out the significant differences between patients with TES with catamenial and noncatamenial symptoms. Such categorization and awareness by clinicians of these differences among patients with TES can be helpful in designing a management strategy. When constructing management guidelines, these differences between patients with catamenial and noncatamenial symptoms should be taken into consideration., (Copyright © 2021. Published by Elsevier Inc.)
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- 2022
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8. The role of Vitamin E in hip implant-related corrosion and toxicity: Initial outcome.
- Author
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Manjunath V, Badhe RV, McCoy M, Rynne J, Bhatti A, Segu A, Oral E, Jacobs JJ, Chastain P 2nd, Bijukumar D, and Mathew MT
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- Animals, Cattle, Corrosion, Metals, Vitamin E, Arthroplasty, Replacement, Hip, Hip Prosthesis adverse effects
- Abstract
In orthopedic healthcare, Total Hip Replacement (THR) is a common and effective solution to hip-related bone and joint diseases/fracture; however, corrosion of the hip implant and the release of degradation metal ions/particles can lead to early implant failure and pose potential toxicity risk for the surrounding tissues. The main objective of this work was to investigate the potential role of Vitamin E to minimize corrosion-related concerns from CoCrMo hip implants. The study focused on two questions (i) Can Vitamin E inhibit CoCrMo corrosion? and (ii) Does Vitamin E moderate the toxicity associated with the CoCrMo implant particles? In the study (i) the electrochemical experiments (ASTM G61) with different concentrations of Vitamin E (1, 2, 3 mg/ml against the control) were performed using normal saline and simulated synovial fluid (Bovine calf serum-BCS, 30 g/L protein, pH 7.4) as electrolytes. The polished CoCrMo disc (Ra 50 nm) was the working electrode. The findings suggested that both Vitamin E-Saline (45 ± 0.9%) and Vitamin E-BCS (91 ± 3%) solutions protected against implant corrosion at a Vitamin E concentration of 3 mg/ml, but Vitamin E-BCS showed protection at all Vitamin E (1-3 mg/ml) concentration levels. These results suggested that the Vitamin E and the protein present in the BCS imparted additive effects towards the electrochemical inhibition. In the study (ii) the role of Vitamin E in cytotoxicity inhibition was studied using a mouse neuroblastoma cell line (N2a) for CoCrMo particles and Cr ions separately. The CoCrMo particles were generated from a custom-built hip simulator. The alamarBlue assay results suggested that Vitamin E provides significant protection (85% and 75% proliferation) to N2a cells against CoCrMo particles and Cr ions, respectively at 1 μg/ml concentration, as compared to the control group. However, the results obtained from ROS expression and DNA fiber staining suggest that Vitamin E is only effective against CoCrMo degradation particles and not against Cr ions. In summary, the findings show that Vitamin E can minimize the corrosion processes and play a role in minimizing the potential toxicity associated with implants., (Copyright © 2021. Published by Elsevier Ltd.)
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- 2021
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9. Differentiation of canine adipose mesenchymal stem cells into insulin-producing cells: comparison of different culture medium compositions.
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Camara BOS, Ocarino NM, Bertassoli BM, Malm C, Araújo FR, Reis AMS, Jorge EC, Alves EGL, and Serakides R
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- Adipogenesis drug effects, Adipogenesis physiology, Animals, Carbazoles chemistry, Carbazoles pharmacology, Chondrogenesis drug effects, Chondrogenesis physiology, Culture Media chemistry, Dogs, Immunophenotyping, Mercaptoethanol pharmacology, Niacinamide chemistry, Niacinamide pharmacology, Osteogenesis drug effects, Osteogenesis physiology, Cell Differentiation, Culture Media pharmacology, Insulin metabolism, Mesenchymal Stem Cells physiology
- Abstract
The aim of this study was to differentiate canine adipose-derived mesenchymal stem cells (ADMSCs) into insulin-producing cells by using culture media with different compositions to determine the most efficient media. Stem cells isolated from the fat tissues close to the bitch uterus were distributed into 6 groups: (1) Dulbecco's modified Eagle medium (DMEM)-high glucose (HG), β-mercaptoethanol, and nicotinamide; (2) DMEM-HG, β-mercaptoethanol, nicotinamide, and exendin-4; (3) DMEM-HG, β-mercaptoethanol, nicotinamide, exendin-4, B27, nonessential amino acids, and l-glutamine; (4) DMEM-HG, β-mercaptoethanol, and nicotinamide (for the initial 8-d period), and DMEM-HG, β-mercaptoethanol, nicotinamide, exendin-4, B27, nonessential amino acids, l-glutamine, and basic fibroblast growth factor (for the remaining 8-d period); (5) DMEM-HG and fetal bovine serum; and (6) DMEM-low glucose and fetal bovine serum (standard control group). Adipose-derived mesenchymal stem cells from groups 1 to 5 gradually became round in shape and gathered in clusters. These changes differed between the groups. In group 3, the cell clusters were apparently more in numbers and gathered as bigger aggregates. Dithizone staining showed that groups 3 and 4 were similar in terms of the mean area of each aggregate stained for insulin. However, only in group 4, the number of insulin aggregates and the total area of aggregates stained were significantly bigger than in the other groups. The mRNA expression of PDX1, BETA2, MafA, and Insulin were also confirmed in all the groups. We conclude that by manipulating the composition of the culture medium it is possible to induce canine ADMSCs into insulin-producing cells, and the 2-staged protocol that was used promoted the best differentiation., (Copyright © 2020 Elsevier Inc. All rights reserved.)
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- 2021
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10. Besides the climate model, other variables driving the COVID-19 spread in Brazil.
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Ribeiro Ribeiro AL and Alves Sousa NW
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- Betacoronavirus, Brazil, COVID-19, Cities, Humans, Humidity, SARS-CoV-2, Temperature, Coronavirus Infections, Pandemics, Pneumonia, Viral, Tropical Climate
- Abstract
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.
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- 2020
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11. Delivery of bupivacaine from UHMWPE and its implications for managing pain after joint arthroplasty.
- Author
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Grindy SC, Gil D, Suhardi JV, Muratoglu OK, Bedair H, and Oral E
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- Analgesia, Anesthetics, Local pharmacokinetics, Arthroplasty, Replacement, Knee, Bupivacaine pharmacokinetics, Coated Materials, Biocompatible chemistry, Delayed-Action Preparations chemistry, Dose-Response Relationship, Drug, Drug Delivery Systems, Drug Liberation, Humans, Pain Management, Staphylococcal Infections drug therapy, Staphylococcal Infections prevention & control, Staphylococcus aureus drug effects, Tensile Strength, Treatment Outcome, Anesthetics, Local chemistry, Bupivacaine chemistry, Pain, Postoperative drug therapy, Polyethylenes chemistry
- Abstract
Total joint replacement is a widely used and successful surgical approach. Approximately 7 million US adults are currently living with a hip or knee replacement. However, the surgical procedures for total joint replacement are associated with significant postoperative pain, and current strategies do not adequately address this pain, which leads to patient dissatisfaction, reduced mobility, and increased risk of opioid addiction. We hypothesized that the ultra-high-molecular-weight polyethylene (UHMWPE) bearing surfaces used in total joint prosthetics could provide sustained release of the local anesthetic bupivacaine to provide relief from joint pain for an extended period of time after surgery. In this paper, we describe the production of bupivacaine-loaded UHMWPE (BPE) and measure the in vitro bupivacaine release kinetics of BPE. We found that bupivacaine could be released from BPE at clinically relevant rates for up to several days and that BPE possesses antibacterial effects. Therefore, bupivacaine-loaded UHMWPE is a promising material for joint replacement prostheses, and future studies will evaluate its safety and efficacy in in vivo models. STATEMENT OF SIGNIFICANCE: Total joint replacement is associated with significant pain and risk of infection. In our paper, we introduce bupivacaine-loaded ultra-high-molecular-weight polyethylene (BPE), which releases bupivacaine, a pain-treating drug, at doses comparable to currently used doses. Additionally, BPE inhibits the growth of infection-causing bacteria. Therefore, BPE may be able to reduce both postsurgical pain and risk of infection, potentially treating two of the most prominent complications associated with total joint replacement. To our knowledge, this is the first development of a material that can address both complications, and devices incorporating BPE would represent a significant advancement in joint arthroplasty prosthetics. More generally, the incorporation of therapeutic agents into ultra-high-molecular-weight polyethylene could impact many orthopedic procedures owing to its ubiquity., (Copyright © 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)
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- 2019
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12. Genotoxic evaluation of selective serotonin-reuptake inhibitors by use of the somatic mutation and recombination test in Drosophila melanogaster.
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Gürbüzel M, Oral E, Kizilet H, Halici Z, and Gulec M
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- Animals, Antidepressive Agents toxicity, DNA Damage, Drosophila melanogaster genetics, Mutagenicity Tests methods, Mutagens toxicity, Selective Serotonin Reuptake Inhibitors toxicity
- Abstract
This study evaluated different concentrations of selective serotonin-reuptake inhibitors (citalopram and sertraline) for genotoxicity by use of the somatic mutation and recombination test (SMART) in Drosophila melanogaster. Three-day-old larvae, trans-heterozygous for the multiple wing hairs (mwh) and flare (flr³) genes were treated with these two compounds. Two recessive markers were located on the left arm of chromosome 3, i.e. 'multiple wing hairs' (mwh) in map position 0.3 and 'flare-3' (flr³) at 38.8, while the centromere was located in position 47.7. SMART is based on the loss of heterozygosity, which may occur through various mechanisms, such as mitotic recombination, mutation, deletion, half-translocation, chromosome loss, and non-disjunction. Genetic changes occurring in somatic cells of the wing's imaginal discs, cause the formation of mutant clones on the wing blade. The results of this study show that citalopram had a genotoxic effect in the Drosophila SMART. Sertraline, however, did not show any genotoxic effect in balancer heterozygous wings. This study concluded that more information is needed to be certain regarding the mutagenic effects of sertraline., (© 2012 Elsevier B.V. All rights reserved.)
- Published
- 2012
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13. Serum oestradiol and beta-HCG measurements after day 3 or 5 embryo transfers in interpreting pregnancy outcome.
- Author
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Kumbak B, Oral E, Karlikaya G, Lacin S, and Kahraman S
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- Adult, Female, Humans, Predictive Value of Tests, Pregnancy, Pregnancy, Multiple, ROC Curve, Retrospective Studies, Time Factors, Chorionic Gonadotropin, beta Subunit, Human blood, Embryo Transfer, Estradiol blood, Fertilization in Vitro methods, Pregnancy Outcome
- Abstract
The aim of this study was to assess the clinical value of serum oestradiol concentration 8 days after embryo transfer (D8E2) and beta-human chorionic gonadotrophin (HCG-beta) concentration 12 days after embryo transfer (D12HCG-beta) in the prediction of pregnancy and the outcome of pregnancy following assisted reproduction, taking into account the day of transfer, which was either day 3 (D3) or day 5 (D5). The objective was to improve patient counselling by giving quantitative and reliable predictive information instead of non-specific uncertainties. A total of 2035 embryo transfer cycles performed between January 2003 and June 2005 were analysed retrospectively. Biochemical pregnancy, ectopic pregnancy and first-trimester abortions were classified as non-viable pregnancies; pregnancies beyond 12 weeks gestation were classified as ongoing pregnancies (OP). Significantly higher D8E2 and D12HCG-beta were obtained in D5 transfers compared with D3 transfers with regard to pregnancy and OP (P
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- 2006
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14. Unmetabolized folic acid in plasma is associated with reduced natural killer cell cytotoxicity among postmenopausal women.
- Author
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Troen AM, Mitchell B, Sorensen B, Wener MH, Johnston A, Wood B, Selhub J, McTiernan A, Yasui Y, Oral E, Potter JD, and Ulrich CM
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- Diet, Female, Folic Acid administration & dosage, Folic Acid metabolism, Hematinics administration & dosage, Hematinics metabolism, Humans, Middle Aged, Folic Acid blood, Hematinics blood, Killer Cells, Natural immunology, Postmenopause blood
- Abstract
Folic acid (FA) supplements and food fortification are used to prevent neural tube defects and to lower plasma homocysteine. Through exposure to food fortification and vitamin supplement use, large populations in the United States and elsewhere have an unprecedented high FA intake. We evaluated dietary and supplemental intakes of folate and FA in relation to an index of immune function, natural killer cell (NK) cytotoxicity, among 105 healthy, postmenopausal women. Among women with a diet low in folate (<233 microg/d), those who used FA-containing supplements had significantly greater NK cytotoxicity (P = 0.01). However, those who consumed a folate-rich diet and in addition used FA supplements > 400 microg/d had reduced NK cytotoxicity compared with those consuming a low-folate diet and no supplements (P = 0.02). Prompted by this observation, we assessed the presence of unmetabolized FA in plasma as a biochemical marker of excess FA. Unmetabolized folic acid was detected in 78% of plasma samples from fasting participants. We found an inverse relation between the presence of unmetabolized FA in plasma and NK cytotoxicity. NK cytotoxicity was approximately 23% lower among women with detectable folic acid (P = 0.04). This inverse relation was stronger among women >or= 60 y old and more pronounced with increasing unmetabolized FA concentrations (P-trend = 0.002). Because of the increased intake of FA in many countries, our findings highlight the need for further studies on the effect of long-term high FA intake on immune function and health.
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- 2006
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15. Young patients with diminished ovarian reserve undergoing assisted reproductive treatments: a preliminary report.
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Kumbak B, Oral E, Kahraman S, Karlikaya G, and Karagozoglu H
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- Adult, Case-Control Studies, Cell Count, Embryo Implantation, Female, Humans, Male, Oocytes physiology, Pregnancy, Pregnancy Rate, Retrospective Studies, Fertilization in Vitro methods, Follicle Stimulating Hormone blood, Ovarian Follicle cytology, Ovary physiopathology
- Abstract
Young assisted-reproduction patients with diminished ovarian reserve (DOR) are one of the most challenging issues for IVF specialists. A retrospective study of 70 assisted reproduction patients younger than 35 years with DOR determined based on antral follicle count was conducted, investigating: (i) correlation of day 3 FSH measurement with antral follicle count; and (ii) cycle outcome of young DOR patients compared with 53 young assisted reproduction patients with normal ovarian reserve (NR). DOR was considered as antral follicle count of <6 per ovary. Day 3 FSH in the DOR group was significantly higher than in the NR group (8.3 and 6.6 mIU/ml respectively; P < 0.05). Implantation rates between the groups were similar (15% in DOR and 18% in NR). Pregnancy rate was 35.8% in the DOR group, significantly lower than that of the NR group, which was 54.7% (P = 0.028). Although the pregnancy rate was significantly lower in the DOR group compared with the NR group, the statistically insignificant difference in implantation rates demonstrated that the problem in young DOR patients was mainly the number of retrieved oocytes. Therefore, such couples should be informed that lower oocyte numbers will result in statistically lower, but still encouraging, pregnancy rates. Basal FSH should also be measured during evaluation as an adjunct to antral follicle count.
- Published
- 2005
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16. In vitro activation of the hemolysin in Prevotella nigrescens ATCC 33563 and Prevotella intermedia ATCC 25611.
- Author
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Silva TA, Noronha FS, de Macêdo Farias L, and Carvalho MA
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- Animals, Edetic Acid pharmacology, Endopeptidase K metabolism, Endopeptidases metabolism, Enzyme Activation, Enzyme Inhibitors pharmacology, Enzyme Stability, Humans, Hydrogen-Ion Concentration, Kinetics, Leucine pharmacology, Pepstatins pharmacology, Phenylmethylsulfonyl Fluoride pharmacology, Prevotella intermedia growth & development, Prevotella nigrescens growth & development, Rabbits, Temperature, Tosyllysine Chloromethyl Ketone pharmacology, Trypsin metabolism, Hemolysin Proteins metabolism, Hemolysis, Leucine analogs & derivatives, Prevotella intermedia metabolism, Prevotella nigrescens metabolism
- Abstract
Hemolytic activity was evaluated in the putative periodontopathogens Prevotella intermedia and Prevotella nigrescens. Whole cells of both species present weak hemolytic activity evidenced only by solid media assays after 48 h of bacterial growth or after 5 h of interaction with erythrocytes at 37 degrees C in liquid assays. In this work we show that the use of crude extract allowed the detection of a higher hemolytic activity for P. intermedia, but surprisingly not for P. nigrescens. Incubation at 37 degrees C for 9 h, or treatment with trypsin or proteinase K, increased or exposed the hemolytic activity of P. intermedia and P. nigrescens crude extract, respectively. The activation process was inhibited by TLCK and PMSF but not by EDTA, E-64 or pepstatin A, indicating the serino-protease nature of the factor involved in activation of P. intermedia and P. nigrescens hemolysins. Both the buffer and the pH employed for cell fractionation influenced the activation of hemolysin, and the best results were obtained with Universal buffer at pH 8.0. The activated hemolysins acted optimally at pH 6.5 at 37 degrees C and the maximum hemolytic activity was detected at the early log phase of growth. The results of this study show for the first time a strong hemolytic activity for P. nigrescens and evidence of proteolytic activation of hemolysins produced by periodontopathogens.
- Published
- 2004
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17. Hemolytic activity of Prevotella intermedia and Prevotella nigrescens strains: influence of abiotic factors in solid and liquid assays.
- Author
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Silva TA, Rodrigues PH, Ribeiro RN, Noronha FS, Farias Lde M, and Carvalho MA
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- Animals, Culture Media, Hemin pharmacology, Horses, Hydrogen-Ion Concentration, Iron physiology, Sheep, Vitamin K 3 pharmacology, Hemolysis drug effects, Prevotella pathogenicity, Prevotella intermedia pathogenicity
- Abstract
The influence of growth medium, hemin and menadione, blood source and atmosphere of incubation on the expression of hemolytic activity of 25 strains of Prevotella intermedia and Prevotella nigrescens was evaluated. The best hemolytic activity was observed for samples of both species growing in brain heart infusion agar and incubated in Brewer-like anaerobic jars for 48 h. Hemolysis was less intense and occurred later in the presence of hemin and menadione in solid media. beta-Hemolysis was detected for medium supplemented with horse or human blood and alpha-hemolysis was observed when sheep blood was used. These results suggesting some specificity for the hemolytic activity were also observed in liquid assays in which sheep erythrocytes were found to be resistant to hemolysis while horse and human cells where lysed. In liquid assays, the hemolytic activity of all studied strains remained stable in the pH range of 6.0 to 8.5 and was not altered by iron-scavenging compounds or atmosphere of incubation. The phenomenon of hot/cold hemolysis was ruled out as the mechanism of action of P. intermedia and P. nigrescens hemolysin.
- Published
- 2003
- Full Text
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18. Bacteriocin production by Fusobacterium isolates recovered from the oral cavity of human subjects with and without periodontal disease and of marmosets.
- Author
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Oliveira AA, Farias LM, Nicoli JR, Costa JE, and Carvalho MA
- Subjects
- Animals, Bacteria growth & development, Callithrix, Fusobacterium growth & development, Fusobacterium isolation & purification, Humans, Antibiosis, Bacteriocins biosynthesis, Fusobacterium metabolism, Mouth microbiology, Periodontal Diseases microbiology
- Abstract
Bacteriocin production has been studied in very few anaerobic bacteria, and no report is available for Fusobacterium species. In the present study a total of 167 Fusobacterium isolates were tested for bacteriocin production: 70 isolates were obtained from the oral cavity of patients with periodontal disease, 47 were recovered from healthy oral sites of human subjects and 50 from the oral cavity of Callithrix penicillata. Autoantagonism and isoantagonism were observed when the bacteriocin-producing isolates were tested against themselves. Heteroantagonism was detected by testing the Fusobacterium isolates against 14 reference strains and 2 strains of Actinobacillus actinomycetemcomitans from our laboratory collection. The auto-, iso- and heteroantagonism phenomena observed in this comparative study suggest a possible ecological role for this (these) antagonistic substance(s) in the oral environment.
- Published
- 1998
- Full Text
- View/download PDF
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