Search

In this randomized parallel study, we examined whether an acute ozone (O3) exposure leads to increased DNA strand breaks in human lymphocytes. The groups were exposed to 0.21 ppm O3 or filtered air for two hours. 30min and 4.5 h after exposure, DNA damage was determined in isolated lymphocytes using the Fast Micromethod. There was no detectable effect after O3 exposure. We conclude that an acute O3 exposure at the tested concentration does not lead to persistent DNA damage. [ABSTRACT FROM AUTHOR]

Abstract Background Vibration-induced white finger disease (VWF), also known as hand-arm vibration syndrome, is a secondary form of Raynaud’s disease, affecting the blood vessels and nerves. So far, little is known about the pathogenesisof the disease. VWF is associated with an episodic reduction in peripheral blood flow. Sirtuin 1, a class III histone deacetylase, has been described to regulate the endothelium dependent vasodilation by targeting endothelial nitric oxide synthase. We assessed Sirt1single nucleotide polymorphisms in patients with VWF to further elucidate the role of sirtuin 1 in the pathogenesis of VWF. Methods Peripheral blood samples were obtained from 74 patients with VWF (male 93.2%, female 6.8%, median age 53 years) and from 317 healthy volunteers (gender equally distributed, below 30 years of age). Genomic DNA was extracted from peripheral blood mononuclear cells and screened for potential Sirt1single nucleotide polymorphisms. Four putative genetic polymorphisms out of 113 within the Sirt1 genomic region (NCBI Gene Reference: NM_012238.3) were assessed. Allelic discrimination was performed by TaqMan-polymerasechainreaction-based allele-specific genotyping single nucleotide polymorphism assays. Results Sirt1single nucleotide polymorphism A2191G (Assay C_25611590_10, rs35224060) was identified within Sirt1 exon 9 (amino acid position 731, Ile → Val), with differing allelic frequencies in the VWF population (A/A: 70.5%, A/G: 29.5%, G/G: 0%) and the control population (A/A: 99.7%, A/G: 0.3%, G/G: 0.5%), with significance levels of P U test (two-tailed) P t-test and Chi-square test with Yates correction (all two-tailed): P Conclusion We identified theSirt1A2191Gsingle nucleotide polymorphism as a diagnostic marker for VWF.

Each pluripotent stem cell line has a physical entity as well as a digital phenotype, but linking the two unambiguously is confounded by poor naming practices and assumed knowledge. Registration gives each line a unique and persistent identifier that links to phenotypic data generated over the lifetime of that line. Registration is a key recommendation of the 2023 ISSCR Standards for the use of human stem cells in research. Here we consider how community adoption of stem cell line registration could facilitate the establishment of integrated digital phenotypes of specific human pluripotent stem cell (hPSC) lines., Competing Interests: Declaration of interests A.K. is the coordinator of the Horizon Europe-funded registry hPSCreg, and C.A.W. is head of the Phenomics Australia-funded Australian stem cell registry. T.E.L. is a co-inventor and receives a share of royalties on various hPSC media and culture-related patents currently held and licensed by the Wisconsin Alumni Research Foundation., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Exposure of firefighting instructors to polycyclic aromatic hydrocarbons (PAHs) such as naphthalene is unavoidable during live fire training. The study aimed to investigate naphthalene uptake by measuring the urinary excretion of the naphthalene metabolite 1,2-dihydroxynaphthalene (DHN), to describe the DHN elimination kinetics and to evaluate the results by comparison to further biomarkers of PAH exposure. N = 6 male non-smoking firefighting instructors completed five training sessions each in a residential fire simulation unit under respiratory protection. All participants provided two urine samples before and another seven samples within an 18-h-interval after each session. DHN was detected by gas chromatography/tandem mass spectrometry (GC-MS/MS) in all samples (n = 237) with median concentrations ranging from 3.3 µg/g crea. (range 0.9-10.2) before exposure to 134.2 µg/g crea. (43.4-380.4) post exposure. Maximum elimination found 3.3 h (median) after onset of exposure decreased with a mean half-life of 6.6 h to 27.1 µg/g crea. (15.7-139.5) 18 h after training. DHN sensitively indicated a presumed dermal naphthalene intake during training, showing similar elimination kinetics like other naphthalene metabolites. Internal exposure of the participants transiently exceeded exposures determined for non-smokers in the general population, but was lower than at other workplaces with PAH exposure. Despite limited uptake, accumulation is possible with daily exposure., (© 2024. The Author(s).)

Individuals with transient reception potential cation channel 6 (TRPC6) mutation have variable phenotypes, ranging from healthy carriers to focal segmental glomerulosclerosis (FSGS). Human induced pluripotent stem cell (hiPSC) line was generated from the urinary cells of a patient with FSGS with a mutant variant of TRPC6. The cells were reprogrammed with Yamanaka factors (OCT3, SOX2, LIN28, L-MYC, and KLF4) using a commercially available Epi5 Reprogramming Kit. The pluripotency of the hiPSC line was confirmed by the expression of common stem cell markers and by their ability to generate all germ layers in vitro. The line is available and registered in the human pluripotent stem cell registry as BCRTi006-A. The generated line represents a valuable tool for disease modeling and drug development for FSGS., 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 © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Autosomal dominant polycystic kidney disease (ADPKD) is a common genetic disorder of adults, characterized by uncontrolled cysts formation that causes a gradual impairment of kidney function. We generated a human induced pluripotent stem cell (hiPSC) line from the urinary cells of a patient diagnosed with ADPKD using a non-integrating Epi5™ Episomal iPSC reprogramming strategy. Characterization of the cell line was performed regarding their undifferentiated status, differentiation potential, and quality control for karyotypic integrity, identity, and clearance of reprogramming vectors. The newly derived hiPSC line, namely BCRTi007-A, can be used in vitro for disease modeling of ADPKD as well as testing for novel therapeutic approaches., 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 © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

The success of human induced pluripotent stem cell (hiPSC)-based therapy critically depends on understanding and controlling the immunological effects of the hiPSC-derived transplant. While hiPSC-derived cells used for cell therapy are often immature with post-grafting maturation, immunological properties may change, with adverse effects on graft tolerance and control. In the present study, the allogeneic and autologous cellular immunity of hiPSC-derived progenitor and terminally differentiated cells were investigated in vitro. In contrast to allogeneic primary cells, hiPSC-derived early renal progenitors and mature renal epithelial cells are both tolerated not only by autologous but also by allogeneic T cells. These immune-privileged properties result from active immunomodulation and low immune visibility, which decrease during the process of cell maturation. However, autologous and allogeneic natural killer (NK) cell responses are not suppressed by hiPSC-derived renal cells and effectively change NK cell activation status. These findings clearly show a dynamic stage-specific dependency of autologous and allogeneic T and NK cell responses, with consequences for effective cell therapies. The study suggests that hiPSC-derived early progenitors may provide advantageous immune-suppressive properties when applied in cell therapy. The data furthermore indicate a need to suppress NK cell activation in allogeneic as well as autologous settings.

Objective: To provide a standardized protocol for large-scale production of proximal tubular epithelial cells (PTEC) generated from human pluripotent stem cells (hPSC)., Methods: The hPSC were expanded and differentiated into PTEC on matrix-coated alginate beads in an automated levitating fluidic platform bioLevitator. Differentiation efficacy was evaluated by immunofluorescence staining and flow cytometry, ultrastructure visualized by electron microscopy. Active reabsorption by PTEC was investigated by glucose, albumin, organic anions and cations uptake assays. Finally, the response to cisplatin-treatment was assessed to check the potential use of PTEC to model drug-induced nephrotoxicity., Results: hPSC expansion and PTEC differentiation could be performed directly on matrix-coated alginate beads in suspension bioreactors. Renal precursors arose 4 days post hPSC differentiation and PTEC after 8 days with 80% efficiency, with a 10-fold expansion from hPSC in 24 days. PTEC on beads, exhibited microvilli and clear apico-basal localization of markers. Functionality of PTECs was confirmed by uptake of glucose, albumin, organic anions and cations and expression of KIM-1 after Cisplatin treatment., Conclusion: We demonstrate the efficient expansion of hPSC, controlled differentiation to renal progenitors and further specification to polarized tubular epithelial cells. This is the first report employing biolevitation and matrix-coated beads in a completely defined medium for the scalable and potentially automatable production of functional human PTEC., (© 2022 The Authors. Cell Proliferation published by John Wiley & Sons Ltd.)

Firefighting instructors in live fire training are inevitably exposed to emissions containing, carcinogenic PAH. The study investigated PAH uptake in a group of firefighting instructors during short-term exposure in live fire training by urinary biomonitoring. Six firefighting instructors (non-smokers) completed five 2 h-training sessions each in a carbonaceous-fired simulation unit using self-containing breathing apparatuses (SCBA). Complying with a minimum time interval of six days between the individual training sessions, the participants provided urine samples before and immediately after, as well as 1, 3, 6, 9, 11, and 18 h after each training session. Samples were analyzed for 10 mono-hydroxylated metabolites of the PAH naphthalene, fluorene, phenanthrene and pyrene using gas chromatography/tandem mass spectrometry. A significant effect of the training sessions on the time course of internal exposure was found (p < 0.0001). The concentration of all parameters clearly increased at the latest 3 h after end of training. After peaking, the concentrations dropped with half-lives between 3.5 and 9.3 h but did not reach the initial levels within 18 h again. Compared to pre-training levels, the increase in metabolite excretion was between 546-933 %. During peak excretion reference values for hydroxynaphthalene (35 μg/L, sum of 1- and 2-isomer) and 1-hydroxypyrene (0.30 μg/L) were exceeded in 64 % (maximum: 381.3 μg/L) and 73 % of the samples (maximum: 1.88 μg/g crea.), respectively. Live fire training is associated with an additional uptake of PAH. Due to the consequent use of SCBA, dermal absorption is assumed as major exposure route. Further measures to reduce PAH exposure should be considered, in particular since higher internal loads caused by accumulation effects are to be expected with daily or more frequent training., Competing Interests: Declaration of competing interest Bernd Rossbach, Daniel Wollschläger, Stephan Letzel are employees of the University Medical Center of the Johannes Gutenberg-University of Mainz, Germany. Axel Muttray has retired; he is a former employee of the University Medical Center of the Johannes Gutenberg-University of Mainz, Germany. The above institution received funding to conduct the study from the magistrate of the City of Frankfurt/Main, Germany. Wolfgang Gottschalk is employee of the City of Frankfurt/Main, Germany. The authors declare the following financial interests/personal relationships which may be considered as potential competing interests., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Tropenol ester is a highly toxic anticholinergic substance and an intermediate used in industrial production of the bronchodilator tiotropium bromide. The aim of this study was to systematically test workers involved in its production for tropenol ester in urine to identify any exposure pathways and define additional preventive measures. Twelve workers performing tasks involving potential exposure to tropenol ester were repeatedly monitored at the end of each production cycle. Medical exams revealed no symptoms of acute poisoning with tropenol ester, but biological monitoring of urine showed 36 positive findings in 79 samples, with tropenol ester concentrations ranging between the detection limit of 54 pg/mL and 2160 pg/mL. We managed to establish the cause of only one positive finding, which was a hole in a protective glove, whereas the rest most likely occurred due to human error. Because of this, the plant decided to modify the production process by replacing tropenol ester with a safer intermediate. While it is the safest course of action, there where it cannot be taken, biological monitoring can be very helpful in raising awareness about exposure to toxic substances, including the new ones that have not been studied for their adverse potential.

Human pluripotent stem cells (hPSCs) provide a source for the generation of defined kidney cells and renal organoids applicable in regenerative medicine, disease modeling, and drug screening. These applications require the provision of hPSC-derived renal cells by reproducible, scalable, and efficient methods. We established a chemically defined protocol by application of Activin A, BMP4, and Retinoic acid followed by GDNF, which steered hPSCs to the renal lineage and resulted in populations of SIX2 + /CITED1 + metanephric mesenchyme- (MM) and of HOXB7 + /GRHL2 + ureteric bud (UB)-like cells already by 6 days. Transcriptome analysis corroborated that the PSC-derived cell types at day 8 resemble their renal vesicle and ureteric epithelial counterpart in vivo, forming tubular and glomerular renal cells 6 days later. We demonstrate that starting from hPSCs, our in vitro protocol generates a pool of nephrogenic progenitors at the renal vesicle stage, which can be further directed into specialized nephronal cell types including mesangial-, proximal tubular-, distal tubular, collecting duct epithelial cells, and podocyte precursors after 14 days. This simple and rapid method to produce renal cells from a common precursor pool in 2D culture provides the basis for scaled-up production of tailored renal cell types, which are applicable for drug testing or cell-based regenerative therapies.

A lack of well-established parameters and assessment values currently impairs biomonitoring of n-heptane exposure. Using controlled inhalation experiments, we collected information on urinary n-heptane metabolite concentrations and the time course of metabolite excretion. Relationships between external and internal exposure were analysed to investigate the suitability of selected metabolites to reflect n-heptane uptake. Twenty healthy, non-smoking males (aged 19-38 years, median 25.5) were exposed for 3 h to 167, 333 and 500 ppm n-heptane, each. Spot urine samples of the volunteers, collected before exposure and during the following 24 h, were analysed for heptane-2-one, 3-one, 4-one, 2,5-dione, 1-ol, 2-ol, 3-ol, and 4-ol using headspace solid phase dynamic extraction gas chromatography/mass spectrometry (HS-SPDE-GC/MS). Starting from median pre-exposure concentrations between <0.5 (3-one) and 82.9 μg/L (4-one), exposure increased the concentrations for all parameters except for 4-one. Median post-exposure concentrations ranged up to 840.4 μg/L (2-ol) and decreased with half-lifes <3 h after exposure. Non-parametric correlation analyses (n = 47, p < 0.05) revealed weak to moderate associations of volume related metabolite excretion with external exposure for 2-one, 3-one and 2,5-dione (R = 0.332-0.753). Heptanol excretion was moderately associated with exposure (R ≥ 0.509) only after creatinine adjustment. Lacking association with external exposure impedes the use of 4-one as heptane biomarker, whereas 2-ol and 3-ol turned out to be sensitive indicators of exposure if creatinine correction is applied. By providing fundamental data on a panel of eight potential heptane metabolites, our study can help to promote biological monitoring of n-heptane exposure., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Native extracellular matrix (ECM) provides scaffolds for tissue engineering with natural architecture and biochemical composition. Maintaining the native ECM in decellularized tissues provides cues for cells, which promote their tissue specific arrangement and function. Several approaches have been used to decellularize ECM from the kidney in order to reestablish renal tissue but their comparability is hampered because methods for decellularization and assessment of ECM vary widely. Therefore, we applied a standardized immersion protocol to decellularize porcine kidney tissue with three detergents Triton X-100, SDS and sodium deoxycholate (SDC) at variable temperatures. For comparative analysis decellularization efficacies, structural preservation, composition and cell attachment and viability were analyzed. Structural ECM-conservation is strongly dependent on decellularization temperature, while preservation of glycosaminoglycans (GAG), collagens and cytokines was affected by the detergents used. GAG and collagens were best maintained by 1% SDS at 4 °C, whereas cytokines were best maintained in 1% SDC at 4 °C. Viability and attachment of human induced pluripotent stem cell derived renal precursor cells were best in SDC-ECM and thus not associated with the degree of GAG and collagen maintenance but the cytokine preservation. Based on structural and functional characteristics, we developed a scoring system that allows intra- and inter-study comparison of decellularization strategies. Application of the scoring system to our experimental data showed that decellularization with 1% SDS at 4 °C provided the highest structural and composition scores, while 1% SDC at 4 °C had lower structural and composition but a significantly better cell performance score. Inclusion of multiple published studies in the scoring matrix for comparison identified the highest structural and composition scores when decellularization was performed with SDS at low concentration, for a short period of time and at low temperature. Furthermore, the scoring system indicated that cell attachment and viability cannot be concluded from any other parameter and should therefore always be included in evaluation of decellularization strategies.

We have generated a human induced pluripotent stem cell (iPSC) line derived from urinary cells of a 28year old healthy female donor. The cells were reprogrammed using a non-integrating viral vector and have shown full differentiation potential. Together with the iPSC line, the donor provided blood cells for the study of immunological effects of the iPSC line and its derivatives in autologous and allogeneic settings. The line is available and registered in the human pluripotent stem cell registry as BCRTi005-A., (Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.)

Purpose: This study aims at experimentally determining the incidence and extent of liquid releases onto the operator's hands and into the work environment during common nursing operations involving infusions., Methods: A sequence of operations related to the preparation and administration of infusions was conducted by three subjects for 15 times each using fluorescein marked infusion solutions and two different infusion sets (standard set vs. safety-optimized set). Unintended release of liquid was quantified by glove and surface wipe sampling and HPLC/FD analysis of the samples. Operations concerning the disposal of infusions were also part of the study., Results: In over 90% of the simulations, a release of infusion solution was observed in a standard workflow, comprising priming and decapping the infusion set, connecting it to a peripheral intravenous (IV) cannula, and detaching it again. Based on median values (229 vs. 26 μl), the release of infusion solution was about ninefold higher when using the non-optimized standard infusion set. During decapping, a hand contamination was found in a majority of cases., Conclusions: The handling of infusions may involve a risk of nurses' exposure to active agents by release of infusion solution into the work environment. According to our results with different infusion sets, exposure risks can be reduced technically and by appropriate handling. Nevertheless, hand contaminations found for both sets emphasize the necessity for additional measures such as more consistent use of protective gloves.

Introduction: It remains unclear if the increased biomechanical stability of the double-row repair is solely a result of the technique itself or due to the greater number of utilized materials. This study analyses the various rotator cuff (RC) repair interfaces and the influence of doubling the number of suture knots, stitch techniques and suture anchors on the primary stability of the RC reconstruction., Materials and Methods: Established cyclic testing protocols were used to test the primary stability of the knot interface with a Duncan loop and Roeder knot, the tendon-to-suture interface with a single-stitch and Mason-Allen-stitch and the anchor-to-bone interface with OPUS Magnum 2® and BioCorkscrew® anchors. After doubling the materials, the interfaces were tested again and compared to the yielded solitary values. The maximum failure loads (Fmax), clinical failure (CF), system displacement (SD) and modes of failure were recorded., Results: Doubling the amount of knots, stitches and suture anchors improved almost all interface parameters. For example, Fmax, CF and SD of the Roeder knot could be significantly improved from 142.5 N to 256.7 N, from 82.5 N to 155.0 N and from 0.45 mm to 0.20 mm, respectively. The Mason-Allen stitch's Fmax improved from 196.4 N to 324.9 N, and CF from 94.25 N to 139.8 N, with almost identical SD of 0.81 mm and 0.84 mm. Bio-Corkscrew® Fmax improved from 232.5 N to 317.5 N, CF from 182.5 N to 210 N, and SD from 0.85 mm to 0.64 mm., Conclusion: Doubling the number of knots, stitches and suture anchors increases the primary stability of the various RC repair interfaces and may result in RC rerupture rate reduction. Furthermore, this study suggests that a suture anchor loaded with two or three sutures may yield the same primary stability as two or three suture anchors loaded with a single suture. This in vitro biomechanical study focuses solely on the rotator cuff interfaces at time zero; the biological healing process was therefore not analysed and requires further investigation., Clinical Relevance: Improved primary stability by increased number of suture materials may reduce rate of RC rerupture.

We have generated a human induced pluripotent stem cell (iPSC) line derived from urinary cells of a 30 year old healthy female donor. The cells were reprogrammed using a non-integrating viral vector and have shown full differentiation potential. Together with the iPSC-line, the donor provided blood cells for the study of immunological effects of the iPSC line and its derivatives in autologous and allogeneic settings. The line is available and registered in the human pluripotent stem cell registry as BCRTi004-A., (Copyright © 2016 University of Texas at Austin Dell Medical School. Published by Elsevier B.V. All rights reserved.)

Due to the increasing demand for functionality in an aging yet physically active society, the treatment of rotator cuff tears is of ever-growing importance. Despite intensive research efforts, the treatment of degenerative rotator cuff tears, in particular their long-term outcome, is still a challenge. While in recent years the focus was on biomechanics and the technical aspects of rotator cuff reconstruction, attention has now turned to the biological considerations of tendon regeneration. This article highlights the current state of biological rotator cuff augmentation in a clinical setting and provides an insight into and an outlook on the experimental procedures.