Role of endogenous glutathione in the secondary damage in experimental spinal cord injury in mice

GSH plays multiple roles in the nervous system including free radical scavenger, redox modulator of ionotropic receptor activity, and possible neurotransmitter. A lot of evidence suggests that GSH is involved in the pathogenesis of neurodegenerative disorders, like spinal cord injury (SCI). This study was undertaken to determine if the inhibition of endogenous glutathione, by L-buthionine-(S,R)-sulfoximine (BSO), affords protection against peroxynitrite-mediated toxicity in response to the spinal cord injury in vivo. The spinal cord of damaged animals showed a significant elevation of biochemical, immunohistochemical and functional parameters, increasing, respectively, neutrophils infiltration, lipid peroxidation, nitrotyrosine formation, PAR expression, apoptosis (measured by TUNEL staining) and loss of hind legs movement in SCI-operated mice. In contrast, the administration of BSO led to worsening of this already compromised setting, increasing the degree of (1) neutrophil infiltration, (2) lipid peroxidation, (3) histological damage, (4) apoptosis, (5) nitrotyrosine formation, (6) PAR expression, (7) apoptosis (measured by TUNEL staining) and (7) loss of hind legs movement. Thus, endogenous glutathione plays an important protective role against secondary damage after SCI.     

P16(INK4a) overexpression independent of Human Papilloma Virus (HPV) infection in rare subtypes of endometrial carcinomas

In the current study, we evaluated p16 expression in rare subtypes of endometrial carcinomas, whose HPV status has been previously examined in order to establish the role of this protein in their pathogenesis. These rare subtypes of endometrial carcinomas are primary squamous endometrial carcinoma (ESCC), endometrial mucinous microglandular adenocarcinoma (EMMA), and endometrial transitional cell carcinoma (ETCC). All tissues, obtained at the time of hysterectomy, were fixed in 10% phosphate-buffered formalin and embedded in paraffin. Serial sections were made for hematoxylin and eosin staining and for immunohistochemistry. Although a previous PCR study has demonstrated that none of these neoplasms showed any signal for HPV DNA, these malignancies did display immunoreactivity for P16(INK4a). In ESCC, P16(INK4a) immunoreactivity was diffuse in 100% of neoplastic cells. In two cases of EMMA, positivity for P16INK4a was zonal. In ETCC, scattered cells were positive for P16INK4a protein. These findings suggest that alteration of p16 could play an etiologic role, without any association to HPV infections, in these rare endometrial carcinomas. However, in our view, other cases of these rare malignancies should be investigated in order to confirm this hypothesis.     

Accidents with risk of blood-borne infections in obstetricians: analysis of a hospital case records

BACKGROUND: Health care workers (HCW) are at high risk of accidental contact with biological fluids. In spite of extensive recom mendations concerning HCW accidents continue to be frequent and seem to be related to specific factors. OBJECTIVES: To evaluate the factors influencing risk of blood-borne infections in a particular category of HCW--obstetricians, and obtain information useful for prevention guidelines. METHODS: Data were obtained from the exposure registers of nursing and of the Emergency Ward staff where HCWfirst report after accidental contact with biological fluids. RESULTS: Accidents with risk of blood-borne diseases were more frequent in obstetricians with lower job seniority. They usually occurred between 8 a.m. and 4p. m., in the patient's room. The hands and face (particularly the eyes) were the body parts more often involved In almost half of the accidents, the worker was not wearing any personal protective device. Although some contacts were with infected blood, no seroconversion occurred. CONCLUSIONS: Obstetricians are at high risk of contact with biologicalfluids. Prevention requires a global strategy including the availability of protective and safety devices, as well as worker education, especially concerning the use of such devices, the application of the universal rules of prevention and the improvement of risk awareness. An adequate post-exposure management of accidents in also required     

Sclerostin Regulation,Microarchitecture, and Advanced Glycation End-Products in the Bone of Elderly Women With Type 2 Diabetes

Increased circulating sclerostin and accumulation of advanced glycation end-products (AGEs) are two potential mechanisms underlying low bone turnover and increased fracture risk in type 2 diabetes (T2D). Whether the expression of the sclerostin-encoding SOST gene is altered in T2D, and whether it is associated with AGEs accumulation or regulation of other bone formation-related genes is unknown. We hypothesized that AGEs accumulate and SOST gene expression is upregulated in bones from subjects with T2D, leading to downregulation of bone forming genes (RUNX2 and osteocalcin) and impaired bone microarchitecture and strength. We obtained bone tissue from femoral heads of 19 T2D postmenopausal women (mean glycated hemoglobin [HbA1c] 6.5%) and 73 age- and BMI-comparable nondiabetic women undergoing hip replacement surgery. Despite similar bone mineral density (BMD) and biomechanical properties, we found a significantly higher SOST (p = .006) and a parallel lower RUNX2 (p = .025) expression in T2D compared with non-diabetic subjects. Osteocalcin gene expression did not differ between T2D and non-diabetic subjects, as well as circulating osteocalcin and sclerostin levels. We found a 1.5-fold increase in total bone AGEs content in T2D compared with non-diabetic women (364.8 ± 78.2 versus 209.9 ± 34.4 μg quinine/g collagen, respectively; p < .001). AGEs bone content correlated with worse bone microarchitecture, including lower volumetric BMD (r = −0.633; p = .02), BV/TV (r = −0.59; p = .033) and increased trabecular separation/spacing (r = 0.624; p = .023). In conclusion, our data show that even in patients with good glycemic control, T2D affects the expression of genes controlling bone formation (SOST and RUNX2). We also found that accumulation of AGEs is associated with impaired bone microarchitecture. We provide novel insights that may help understand the mechanisms underlying bone fragility in T2D. © 2020 American Society for Bone and Mineral Research (ASBMR).     

Effects of anticoagulants on the activity of gelatinases

OBJECTIVES: To identify the best procedure for preanalytical blood collection in the determination of matrix metalloproteinase (MMP)-2 and -9 by testing the effects of anticoagulants on their activity. DESIGN AND METHODS: Active forms of both gelatinases were measured by specific activity assay systems in serum, plasma EDTA, plasma-heparin and plasma-citrate obtained from 20 healthy volunteers, as well as in a pooled serum sample before and after anticoagulant treatment. RESULTS:: Active MMP-2 and MMP-9 mean concentrations were similar in serum and in plasma-citrate, higher in plasma EDTA than in serum, in plasma-heparin and in plasma-citrate, and lower in plasma-heparin than in serum and plasma-citrate. A similar trend was observed in untreated and treated pooled serum samples. CONCLUSIONS: Our results indicate that MMP-2 and MMP-9 in their active forms are not released by platelets during blood clotting, whereas the use of calcium chelating anticoagulants can profoundly alter the activity of endogenous gelatinases. This suggests that the determination of active forms of MMP-2 and MMP-9 in serum samples represents a suitable procedure.     

The analysis of myotonia congenita mutations discloses functional clusters of amino acids within the CBS2 domain and the C‐terminal peptide of the ClC‐1 channel

Myotonia congenita (MC) is a skeletal‐muscle hyperexcitability disorder caused by loss‐of‐function mutations in the ClC‐1 chloride channel. Mutations are scattered over the entire sequence of the channel protein, with more than 30 mutations located in the poorly characterized cytosolic C‐terminal domain. In this study, we characterized, through patch clamp, seven ClC‐1 mutations identified in patients affected by MC of various severities and located in the C‐terminal region. The p.Val829Met, p.Thr832Ile, p.Val851Met, p.Gly859Val, and p.Leu861Pro mutations reside in the CBS2 domain, while p.Pro883Thr and p.Val947Glu are in the C‐terminal peptide. We showed that the functional properties of mutant channels correlated with the clinical phenotypes of affected individuals. In addition, we defined clusters of ClC‐1 mutations within CBS2 and C‐terminal peptide subdomains that share the same functional defect: mutations between 829 and 835 residues and in residue 883 induced an alteration of voltage dependence, mutations between 851 and 859 residues, and in residue 947 induced a reduction of chloride currents, whereas mutations on 861 residue showed no obvious change in ClC‐1 function. This study improves our understanding of the mechanisms underlying MC, sheds light on the role of the C‐terminal region in ClC‐1 function, and provides information to develop new antimyotonic drugs.     

Chloroquine enhances human CD8+ T cell responses against soluble antigens in vivo

The presentation of exogenous protein antigens in a major histocompatibility complex class I-restricted fashion to CD8+ T cells is called cross-presentation. We demonstrate that cross-presentation of soluble viral antigens (derived from hepatitis C virus [HCV], hepatitis B virus [HBV], or human immunodeficiency virus) to specific CD8+ T cell clones is dramatically improved when antigen-presenting dendritic cells (DCs) are pulsed with the antigen in the presence of chloroquine or ammonium chloride, which reduce acidification of the endocytic system. The export of soluble antigen into the cytosol is considerably higher in chloroquine-treated than in untreated DCs, as detected by confocal microscopy of cultured cells and Western blot analysis comparing endocytic and cytosolic fractions. To pursue our findings in an in vivo setting, we boosted groups of HBV vaccine responder individuals with a further dose of hepatitis B envelope protein vaccine with or without a single dose of chloroquine. Although all individuals showed a boost in antibody titers to HBV, six of nine individuals who were administered chloroquine showed a substantial CD8+ T cell response to HBV antigen, whereas zero of eight without chloroquine lacked a CD8 response. Our results suggest that chloroquine treatment improves CD8 immunity during vaccination.