494 research outputs found
A new LC-MS/MS method for simultaneous and quantitative detection of bisphenol-a and steroids in target tissues: A power tool to characterize the interference of bisphenol-a exposure on steroid levels
Bisphenol A (BPA), an endocrine disruptor, may affect in situ steroidogenesis and alter steroids levels. The present work proposes a liquid chromatography tandem mass spectrometry method to simultaneously quantify BPA, 17ÎČ-Estradiol and testosterone in two target tissues: testis and visceral fat mass. Analytes were isolated and lipophilic impurities removed by two serial steps: liquid-liquid and solid phase extraction. All compounds were separated in a single gradient run by Kinetex F5 column and detected via multiple reaction monitoring using a triple quadrupole with a TurboIon electrospray source in both negative and positive modes. The method is selective and very sensitive. In the investigated concentration range, the linearity of the detector response is verified in both tissues. The use of specific SPE cartridges for affinity chromatography purification allows obtaining high percentages of process efficiency (68.0-83.3% for testicular tissue; 63.7-70.7% for visceral fat mass). Good repeatability and reproducibility was observed. The validated method can be efficiently applied for direct biological monitoring in testis and visceral fat mass from mice exposed to BPA. The quantification of compounds in a single assay could be achieved without a loss of sensitivity
IgD Multiple Myeloma Paraproteinemia as a Cause of Myositis
A 48-years old man was diagnosed an IgD-k multiple myeloma (MM) at age 38 years for which he successfully underwent chemotherapy and bone marrow transplant. He then developed a graft-versus-host disease (GVHD) whose manifestations included, three years later, a polymyositis, diagnosed at muscle biopsy and successfully treated with steroids. Few months after polymyositis remission, myeloma relapsed and the patient was treated with thalidomide for six years with good remission. Soon after thalidomide suspension, MM relapsed again and the patient came to our observation for a new onset of neuromuscular symptoms. He underwent both muscle and peripheral nerve biopsy to discriminate between myositis (paraproteinemia versus GVHD), amyloidosis, and thalidomide toxicity. The first muscle biopsy showed an inflammatory pattern with necrotic fibres, macrophagical invasion (CD68 positive), rare interstitial cellular infiltrates (CD8 positive and CD4 negative), widespread anti-HLA positivity and negative antiMAC. The second muscle biopsy showed the same inflammatory pattern plus an involvement of blood vessels. Direct immunofluorescence for IgD showed diffuse positivity along the sarcolemmal in both muscle biopsies. Sural nerve biopsy demonstrated both demyelinating and axonal aspects with no inflammatory infiltrates, but positivity for HLA and MAC. Congo Red was negative in both skeletal muscle and peripheral nerve
The effects of an intronic polymorphism in TOMM40 and APOE genotypes in sporadic inclusion body myositis.
A previous study showed that, in carriers of the apolipoprotein E (APOE) genotype Δ3/Δ3 or Δ3/Δ4, the presence of a very long (VL) polyT repeat allele in "translocase of outer mitochondrial membrane 40" (TOMM40) was less frequent in patients with sporadic inclusion body myositis (sIBM) compared with controls and associated with a later age of sIBM symptom onset, suggesting a protective effect of this haplotype. To further investigate the influence of these genetic factors in sIBM, we analyzed a large sIBM cohort of 158 cases as part of an International sIBM Genetics Study. No significant association was found between APOE or TOMM40 genotypes and the risk of developing sIBM. We found that the presence of at least 1 VL polyT repeat allele in TOMM40 was significantly associated with about 4 years later onset of sIBM symptoms. The age of onset was delayed by 5 years when the patients were also carriers of the APOE genotype Δ3/Δ3. In addition, males were likely to have a later age of onset than females. Therefore, the TOMM40 VL polyT repeat, although not influencing disease susceptibility, has a disease-modifying effect on sIBM, which can be enhanced by the APOE genotype Δ3/Δ3
Bisphenol A and Bisphenol S Induce Endocrine and Chromosomal Alterations in Brown Trout
Bisphenol A is a widely used compound found in large amount of consumer products. As concerns have been raised about its toxicological and public health effect, the use of alternatives to bisphenol A are now increasing. Bisphenol S is one of the analogues being used as a replacement for bisphenol A despite the fact that little is known about the effects of bisphenol S on living organisms. In this study, we investigated the potential endocrine and genotoxic effects of bisphenol A and bisphenol S in juvenile brown trout (Salmo trutta). The fish were exposed to the compounds for either 2 weeks or 8 weeks via sustained-release cholesterol implants containing doses of 2 mg/kg fish or 20 mg/kg fish of the substances. The effects on the thyroid hormone levels and the estrogenic disrupting marker vitellogenin were evaluated, along with the genotoxic markers micronucleated cells and erythrocyte nuclear abnormalities. An increase in plasma vitellogenin was observed in fish exposed to the high dose of bisphenol A for 2 weeks. At this experimental time the level of the thyroid hormone triiodothyronine (T3) in plasma was elevated after bisphenol S exposure at the high concentration, and paralleled by an increase of micronucleated cells. Moreover, bisphenol A induced an increase of micronuclei frequency in fish erythrocytes after the exposure at the lowest dose tested. Taken together the results indicate that both bisphenol A and its alternative bisphenol S cause endocrine disrupting and genotoxic effects in brown trout, although suggesting two different mechanisms of damage underlying bisphenol A and bisphenol S activity
Effect of interchain separation on the photoinduced absorption spectra of polycarbazolyldiacetylenes
The photoinduced absorption spectra of a novel polycarbazolyldiacetylene with long aliphatic chains on the carbazolyl side groups are measured and compared with those of the unsubstituted polyDCHD. The two polymers in the blue form exhibit very similar electronic absorption spectra and Raman frequencies. This fact indicates that the conjugation length of the polydiacetylene backbone is not too affected by the long substituents. In contrast, the near steady-state photoinduced absorption spectra show that different photogeneration mechanisms are involved in the two polymers. This result can be ascribed to the role played by the interchain distance in the dynamics of the relaxation processes in polydiacetylenes
Elucidating the role of Agl in bladder carcinogenesis by generation and characterization of genetically engineered mice
Amylo-\u3b1-1,6-glucosidase,4-\u3b1-glucanotransferase (AGL) is an enzyme primarily responsible for glycogen debranching. Germline mutations lead to glycogen storage disease type III (GSDIII). We recently found AGL to be a tumor suppressor in xenograft models of human bladder cancer (BC) and low levels of AGL expression in BC are associated with poor patient prognosis. However, the impact of low AGL expression on the susceptibility of normal bladder to carcinogenesis is unknown. We address this gap by developing a germline Agl knockout (Agl-/-) mouse that recapitulates biochemical and histological features of GSDIII. Agl-/- mice exposed to N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) had a higher BC incidence compared with wild-type mice (Agl+/+). To determine if the increased BC incidence observed was due to decreased Agl expression in the urothelium specifically, we developed a urothelium-specific conditional Agl knockout (Aglcko) mouse using a Uroplakin II-Cre allele. BBN-induced carcinogenesis experiments repeated in Aglcko mice revealed that Aglcko mice had a higher BC incidence than control (Aglfl/fl) mice. RNA sequencing revealed that tumors from Agl-/- mice had 19 differentially expressed genes compared with control mice. An 'Agl Loss' gene signature was developed and found to successfully stratify normal and tumor samples in two BC patient datasets. These results support the role of AGL loss in promoting carcinogenesis and provide a rationale for evaluating Agl expression levels, or Agl Loss gene signature scores, in normal urothelium of populations at risk of BC development such as older male smokers
ISPD mutations account for a small proportion of Italian Limb Girdle Muscular Dystrophy cases
Background: Limb Girdle Muscular Dystrophy (LGMD), caused by defective a\u3b1-dystroglycan (a\u3b1-DG) glycosylation, was recently associated with mutations in Isoprenoid synthase domain-containing (ISPD) and GDP-mannose pyrophosphorylase B (GMPPB) genes. The frequency of ISPD and GMPPB gene mutations in the LGMD population is unknown. Methods: We investigated the contributions of ISPD and GMPPB genes in a cohort of 174 Italian patients with LGMD, including 140 independent probands. Forty-one patients (39 probands) from this cohort had not been genetically diagnosed. The contributions of ISPD and GMPPB were estimated by sequential a\u3b1-DG immunohistochemistry (IHC) and mutation screening in patients with documented a\u3b1-DG defect, or by direct DNA sequencing of both genes when muscle tissue was unavailable. Results: We performed a\u3b1-DG IHC in 27/39 undiagnosed probands: 24 subjects had normal a\u3b1-DG expression, two had a partial deficiency, and one exhibited a complete absence of signal. Direct sequencing of ISPD and GMPPB revealed two heterozygous ISPD mutations in the individual who lacked a\u3b1-DG IHC signal: c.836-5 T > G (which led to the deletion of exon 6 and the production of an out-of-frame transcript) and c.676 T > C (p.Tyr226His). This patient presented with sural hypertrophy and tip-toed walking at 5 years, developed moderate proximal weakness, and was fully ambulant at 42 years. The remaining 12/39 probands did not exhibit pathogenic sequence variation in either gene. Conclusion:ISPD mutations are a rare cause of LGMD in the Italian population, accounting for less than 1 % of the entire cohort studied (FKRP mutations represent 10 %), while GMPPB mutations are notably absent in this patient sample. These data suggest that the genetic heterogeneity of LGMD with and without a\u3b1-DG defects is greater than previously realized
Genetic defects are common in myopathies with tubular aggregates
Objective: A group of genes have been reported to be associated with myopathies with tubular aggregates (TAs). Many cases with TAs still lack of genetic
clarification. This study aims to explore the genetic background of cases with
TAs in order to improve our knowledge of the pathogenesis of these rare
pathological structures. Methods: Thirty-three patients including two family
members with biopsy confirmed TAs were collected. Whole-exome sequencing
was performed on 31 unrelated index patients and a candidate gene search
strategy was conducted. The identified variants were confirmed by Sanger
sequencing. The wild-type and the mutant p.Ala11Thr of ALG14 were transfected into human embryonic kidney 293 cells (HEK293), and western blot
analysis was performed to quantify protein expression levels. Results: Eleven
index cases (33%) were found to have pathogenic variant or likely pathogenic
variants in STIM1, ORAI1, PGAM2, SCN4A, CASQ1 and ALG14. Among them,
the c.764A>T (p.Glu255Val) in STIM1 and the c.1333G>C (p.Val445Leu) in
SCN4A were novel. Western blot analysis showed that the expression of ALG14
protein was severely reduced in the mutant ALG14 HEK293 cells (p.Ala11Thr)
compared with wild type. The ALG14 variants might be associated with TAs in
patients with complex multisystem disorders. Interpretation: This study
expands the phenotypic and genotypic spectrums of myopathies with TAs. Our
findings further confirm previous hypothesis that genes related with calcium
signalling pathway and N-linked glycosylation pathway are the main genetic
causes of myopathies with TAs
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