Cтволовые клетки в стоматологии будущего

Tooth loss compromises human oral health. Although several prosthetic methods (such as artificial denture and dental implants) are clinical therapies to tooth loss problems, they are thought to have safety and usage-time issues. Recently, tooth tissue engineering has attracted more and more attention. Stem cell based tissue engineering is thought to be a promising way to replace the missing tooth. Mesenchymal stem cells (MSC) are multipotent stem cells which can differentiate into a variety of cell types. The potential MSC for tooth regeneration mainly include stem cells from human exfoliated deciduous teeth, adult dental pulp stem cells, stem cells from the apical part of the papilla, stem cells from the dental follicle, periodontal ligament stem cells and bone marrow-derived mesenchymal stem cells. This review outlines the recent progress in mesenchymal stem cell research and its use in tooth regeneration and oral and craniofacial applications.Потеря зубов ставит под угрозу человеческое здоровье. Ткани зуба у взрослых практически не способны к самостоятельной регенерации и дефект эмали, возникающий в результате действия повреждающих факторов, постепенно приводит к потере зуба. Без сомнения, современные технологии протезирования позволяют произвести реконструкцию даже при полном отсутствии зубов. Однако прогресс современной органотипической регенеративной медицины заставляет исследователей искать новые технологии замещения зубов естественными трансплантатами. Последнее время клеточная инженерия тканей зуба привлекает все больше и больше внимания. Стволовые клетки являются многообещающим способом замены недостающего зуба. Мезенхимальные стволовые клетки способны дифференцироваться в клетки костной ткани, что дает возможность использовать их для восстановления зуба. Этот обзор рассматривает современные исследования стволовых клеток и возможность их использования для стимуляции репаративной регенерации тканей зуба

Maternal arsenic exposure and impaired glucose tolerance during pregnancy

Background: Accumulating evidence has shown an increased risk of type 2 diabetes in general populations exposed to arsenic, but little is known about exposures during pregnancy and the association with gestational diabetes (GD). Objectives: We studied 532 women living proximate to the Tar Creek Superfund Site to investigate whether arsenic exposure is associated with impaired glucose tolerance during pregnancy. Methods: Blood glucose was measured between 24 and 28 weeks gestation after a 1-hr oral glucose tolerance test (GTT) as part of routine prenatal care. Blood and hair were collected at delivery and analyzed for arsenic using inductively coupled plasma mass spectrometry with dynamic reaction cell. Results: Arsenic concentrations ranged from 0.2 to 24.1 μg/L (ppb) (mean ± SD, 1.7 ±1.5) and 1.1 to 724.4 ng/g (ppb) (mean ± SD, 27.4 ± 61.6) in blood and hair, respectively. One-hour glucose levels ranged from 40 to 284 mg/dL (mean ± SD, 108.7 ± 29.5); impaired glucose tolerance was observed in 11.9% of women when using standard screening criterion (> 140 mg/dL). Adjusting for age, Native-American race, prepregnancy body mass index, Medicaid use, and marital status, women in the highest quartile of blood arsenic exposure had 2.8 higher odds of impaired GTT than women in the lowest quartile of exposure (95% confidence interval, 1.1–6.9) (p-trend = 0.008). Conclusions: Among this population of pregnant women, arsenic exposure was associated with increased risk of impaired GTT at 24–28 weeks gestation and therefore may be associated with increased risk of GD

Cross-Sectional Associations between Exposure to Persistent Organic Pollutants and Leukocyte Telomere Length among U.S. Adults in NHANES, 2001-2002.

Background: Exposure to persistent organic pollutants (POPs) such as dioxins, furans, and polychlorinated biphenyls (PCBs) may influence leukocyte telomere length (LTL), a biomarker associated with chronic disease. In vitro research suggests dioxins may bind to the aryl hydrocarbon receptor (AhR) and induce telomerase activity, which elongates LTL. However, few epidemiologic studies have investigated associations between POPs and LTL. Objectives: We examined the association between 18 PCBs, 7 dioxins, and 9 furans and LTL among 1,330 U.S. adults from NHANES 2001-2002. Methods: We created three summed POP metrics based on toxic equivalency factor (TEF), a potency measure including affinity for the AhR: (a) non-dioxin-like PCBs (composed of 10 non-dioxin-like PCBs; no AhR affinity and no TEF); (b) non-ortho PCBs (composed of 2 non-ortho-substituted PCBs with high TEFs); and (c) toxic equivalency (TEQ) (composed of 7 dioxins, 9 furans, 2 non-ortho-substituted PCBs, and 6 mono-ortho-substituted PCBs; weighted by TEF). We tested the association between each metric and LTL using linear regression, adjusting for demographics, blood cell count and distribution, and another metric with a different TEF (i.e., non-ortho PCBs and TEQ adjusted for non-dioxin-like PCBs; non-dioxin-like PCBs adjusted for non-ortho PCBs). Results: In adjusted models, each doubling of serum concentrations of non-ortho PCBs and TEQ was associated with 3.74% (95% CI: 2.10, 5.40) and 5.29% (95% CI: 1.66, 9.05) longer LTLs, respectively. Compared with the lowest quartile, the highest quartile of exposure was associated with 9.16% (95% CI: 2.96, 15.73) and 7.84% (95% CI: -0.53, 16.92) longer LTLs, respectively. Non-dioxin-like PCBs were not associated with LTL. Conclusions: POPs with high TEFs and AhR affinity were associated with longer LTL. Because many dioxin-associated cancers are also associated with longer LTL, these results may provide insight into the mechanisms underlying PCB- and dioxin-related carcinogenesis

A study of bronchial asthma in school going children in Southern part of Rajasthan

Background: Asthma is a chronic and common inflammatory disease involving mainly large airways of lungs. Childhood asthma is common chronic illness among school going children and is usually underdiagnosed and undertreated. The aim of the present study was to find out of the prevalence of Bronchial asthma in school going children of age group 6-12 years in southern part of Rajasthan (India), and its relation with gender, socio-economic status and heredity.Methods: A questionnaire-based study has been carried out in 1500 children of 6 to 12 years age group in four schools of Udaipur city (Rajasthan, India) with a response rate of 60.23% (904/1500).Results: The overall prevalence of asthma observed is 4.75% (43/904). The prevalence is higher among boys (5.55%) as compared to girls (3.75%). Further the prevalence is higher in upper (7.18%) and upper middle class (7.14%) children as compared to lower middle (4.84%) and upper lower class (2.01%) socioeconomic status. The children with positive family history of asthma also have higher prevalence (26.31%) of asthma.Conclusions: The prevalence of childhood asthma in Udaipur city is relatively lower and supports the already reported relation with gender, socioeconomic status and heredity.

An overview of methods to address distinct research questions on environmental mixtures: an application to persistent organic pollutants and leukocyte telomere length

Background Numerous methods exist to analyze complex environmental mixtures in health studies. As an illustration of the different uses of mixture methods, we employed methods geared toward distinct research questions concerning persistent organic chemicals (POPs) as a mixture and leukocyte telomere length (LTL) as an outcome. Methods With information on 18 POPs and LTL among 1,003 U.S. adults (NHANES, 2001-2002), we used unsupervised methods including clustering to identify profiles of similarly exposed participants, and Principal Component Analysis (PCA) and Exploratory Factor Analysis (EFA) to identify common exposure patterns. We also employed supervised learning techniques, including penalized, weighted quantile sum (WQS), and Bayesian kernel machine (BKMR) regressions, to identify potentially toxic agents, and characterize nonlinear associations, interactions, and the overall mixture effect. Results Clustering separated participants into high, medium, and low POP exposure groups; longer log-LTL was found among those with high exposure. The first PCA component represented overall POP exposure and was positively associated with log-LTL. Two EFA factors, one representing furans and the other PCBs 126 and 118, were positively associated with log-LTL. Penalized regression methods selected three congeners in common (PCB 126, PCB 118, and furan 2,3,4,7,8-pncdf) as potentially toxic agents. WQS found a positive overall effect of the POP mixture and identified six POPs as potentially toxic agents (furans 1,2,3,4,6,7,8-hxcdf, 2,3,4,7,8-pncdf, and 1,2,3,6,7,8-hxcdf, and PCBs 99, 126, 169). BKMR found a positive linear association with furan 2,3,4,7,8-pncdf, suggestive evidence of linear associations with PCBs 126 and 169, and a positive overall effect of the mixture, but no interactions among congeners. Conclusions Using different methods, we identified patterns of POP exposure, potentially toxic agents, the absence of interaction, and estimated the overall mixture effect. These applications and results may serve as a guide for mixture method selection based on specific research questions

The estimation of the peculiarities and the activity degree of the consisting inflammatory processes in the benign prostatic hyperplasia

Secţia Urologie, IMSP Spitalul Clinic Municipal “ Sf. Treime”, Catedra Morfopatologie, USMF „N. Testemiţanu”, Secţia Ştiinţifică Morfopatologie, IMSP Institutul de Cercetări Ştiinţifice în Domeniul Ocrotirii Sănătăţii Mamei şi Copilului, Catedra Urologie şi Nefrologie Chirurgicală, USMF „N. Testemiţanu”, Al V-lea Congres de Urologie, Dializă şi Transplant Renal din Republica Moldova cu participare internaţională (1-13 iunie 2011)Summary. The conducted study has the aim to estimate the histopathological peculiarities of the inflammatory processes, evaluated in prostatic nodular hyperplasia, the character and the activity of these processes in the area of nodular hyperplasia structures, and the border limit in the adenectomy. The results of the morphopathological study allowed detailed diagnosis of the prostatic hyperplasia. Severe modifications of inflammatory origin and considerable implications of the structural-architectonical components indicate concomitant persisting or coexisting of chronic or acute prostatitis. The establishment of the lesion character, activity degree of the inflammatory process, saving border limit in the surgical management regarding the residual cavity of cleavage and postoperative prognosis was the second aim of the study. It facilitates the choice of the best therapeutic and surgical approach. The character of the inflammatory processes coexisting with prostatic benign hyperplasia was evaluated. A clinical-morphological concept of inflammatory associations in prostate benign hyperplasia was formulated

Temporal Comparison of PBDEs, OH-PBDEs, PCBs, and OH-PCBs in the Serum of Second Trimester Pregnant Women Recruited from San Francisco General Hospital, California

Prenatal exposures to polybrominated diphenyl ethers (PBDEs) can harm neurodevelopment in humans and animals. In 2003–2004, PentaBDE and OctaBDE were banned in California and phased-out of US production; resulting impacts on human exposures are unknown. We previously reported that median serum concentrations of PBDEs and their metabolites (OH-PBDEs) among second trimester pregnant women recruited from San Francisco General Hospital (2008–2009; n=25) were the highest among pregnant women worldwide. We recruited another cohort from the same clinic in 2011–2012 (n=36) and now compare serum concentrations of PBDEs, OH-PBDEs, polychlorinated biphenyl ethers (PCBs) (structurally similar compounds banned in 1979), and OH-PCBs between two demographically similar cohorts. Between 2008–2009 and 2011–2012, adjusted least square geometric mean (LSGM) concentrations of ΣPBDEs decreased 65% (95% CI: 18, 130) from 90.0 ng/g lipid (95% CI: 64.7,125.2) to 54.6 ng/g lipid (95% CI: 39.2, 76.2) (p=0.004); Σ OH-PBDEs decreased six-fold (p<0.0001); and BDE-47, -99, and -100 declined more than BDE-153. There was a modest, non-significant (p=0.13) decline in LSGM concentrations of ΣPCBs and minimal differences in ΣOH-PCBs between 2008–2009 and 2011–2012. PBDE exposures are likely declining due to regulatory action, but the relative stability in PCB exposures suggests PBDE exposures may eventually plateau and persist for decades

Institutional review board challenges related to community-based participatory research on human exposure to environmental toxins: A case study

<p>Abstract</p> <p>Background</p> <p>We report on the challenges of obtaining Institutional Review Board (IRB) coverage for a community-based participatory research (CBPR) environmental justice project, which involved reporting biomonitoring and household exposure results to participants, and included lay participation in research.</p> <p>Methods</p> <p>We draw on our experiences guiding a multi-partner CBPR project through university and state Institutional Review Board reviews, and other CBPR colleagues' written accounts and conference presentations and discussions. We also interviewed academics involved in CBPR to learn of their challenges with Institutional Review Boards.</p> <p>Results</p> <p>We found that Institutional Review Boards are generally unfamiliar with CBPR, reluctant to oversee community partners, and resistant to ongoing researcher-participant interaction. Institutional Review Boards sometimes unintentionally violate the very principles of beneficence and justice which they are supposed to uphold. For example, some Institutional Review Boards refuse to allow report-back of individual data to participants, which contradicts the CBPR principles that guide a growing number of projects. This causes significant delays and may divert research and dissemination efforts. Our extensive education of our university Institutional Review Board convinced them to provide human subjects protection coverage for two community-based organizations in our partnership.</p> <p>Conclusions</p> <p>IRBs and funders should develop clear, routine review guidelines that respect the unique qualities of CBPR, while researchers and community partners can educate IRB staff and board members about the objectives, ethical frameworks, and research methods of CBPR. These strategies can better protect research participants from the harm of unnecessary delays and exclusion from the research process, while facilitating the ethical communication of study results to participants and communities.</p