Impact of PNPLA3 and TM6SF2 polymorphisms on the prognosis of patients with MASLD and type 2 diabetes mellitus.

BACKGROUND/AIMS: Longitudinal studies assessing the impact of genetic polymorphisms on outcomes in patients with Type 2 Diabetes Mellitus (T2DM) and Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) are scarce. This study aimed to evaluate the effect of PNPLA3 and TM6SF2 risk alleles on hepatic and extrahepatic outcomes in T2DM-MASLD individuals. METHODS: Patients' polymorphisms were analysed as follows: PNPLA3 CC, CG and GG; TM6SF2 CC and CT + TT; combined comparing no mutant allele, one allele G or T or ≥2 alleles G or T. Hierarchical models were built to assess associations between polymorphisms and outcomes, independently of confounding factors. Multivariate logistic regression was used for cirrhosis and its complications and extrahepatic cancer, and Cox regression for cardiovascular events (CVEs) and all-cause mortality. RESULTS: In total, 407 T2DM-MASLD patients (62.1 ± 10.5 years, 67.6% women) were followed for 11 (6-13) years. Having at least one G or T allele independently increased the risk of cirrhosis in the separate analysis of PNPLA3 and TM6SF2. Combined polymorphism analysis demonstrated an even higher risk of cirrhosis if two or more risk alleles were present (OR 18.48; 95% CI 6.15-55.58; p < .001). Regarding cirrhosis complications, the risk was higher in PNPLA3 GG and TM6SF2 CT + TT, also with an even higher risk when two or more risk alleles were present in the combined evaluation (OR 27.20; 95% CI 5.26-140.62; p < .001). There were no associations with CVEs or mortality outcomes. CONCLUSION: In T2DM, PNPLA3 and TM6SF2 polymorphisms, individually and additively, impact MASLD severity, with an increased risk of cirrhosis and its complications.

Parental History of Type 2 Diabetes Mellitus and PNPLA3 Polymorphism Increase the Risk of Severe Stages of Nonalcoholic Fatty Liver Disease.

BACKGROUND & AIMS: In non-alcoholic fatty liver disease (NAFLD), the influence of parental history of type 2 diabetes (T2D) allied to single nucleotide polymorphisms (SNPs) in the offspring is not known. We aimed to investigate the impact of the parental history of T2D, PNPLA3 and TM6SF2 polymorphisms in liver steatosis and fibrosis. METHODS: This was a case-control study involving the offspring of T2D patients and controls without a parental history of T2D. Participants underwent clinical and laboratory evaluation, transient elastography (TE) by Fibroscan® (Echosens, Fr) and genotyping for PNPLA3 and TM6SF2. Multivariate logistic regression evaluated the influence of parental history of T2D on liver steatosis and fibrosis, controlled for age, gender, metabolic traits and SNPs. RESULTS: 161 T2D offspring and 78 controls, 10-46 years old, were included. The offspring of T2D had higher prevalences of obesity, T2D, arterial hypertension and sedentarism. Parental history of T2D was associated with fibrosis ≥ F2 (OR 8.89, CI 95% 1.09-72.01, p = 0.041) after adjustment for age, gender, metabolic traits and SNPs. PNPLA3 GG genotype was independently associated with steatosis ≥ S1 (OR 8.15, CI 95% 1.93-34.38, p = 0.004) and fibrosis ≥ F2 (OR 4.31, CI 95% 1.11-16.61, p = 0.034). CONCLUSIONS: The offspring of T2D patients present a worse metabolic profile and the parental history of T2D confers an increased likelihood of hepatic fibrosis, independent of metabolic factors. PNPLA3 homozygous GG, but not TM6SF2 genotypes, also impacts on this phenotype.

Passive exposure to electronic cigarette aerosol in pregnancy: A case study of a family.

BACKGROUND: Passive exposure to the aerosols of electronic cigarettes (e-cigarettes) has been little studied. We assessed this exposure in late pregnancy in a woman and her 3-year-old child, exposed through e-cigarette use by another household member. METHODS: This prospective longitudinal case study involved a family unit consisting of an e-cigarette user, a pregnant woman who delivered an infant during the study, and the couple's older 3-year-old son. At 31, 36, and 40 weeks of the pregnancy, we measured biomarkers (nicotine metabolites, tobacco-specific nitrosamines, propanediols, glycerol, and metals) in the urine and hair of all three participants and in the saliva of the adults, in cord blood at delivery, and in the breast milk at the postpartum period. RESULTS: Samples from the e-cigarette user showed quantifiable concentrations of all analytes assessed (maximum urinary cotinine concentration, 4.9 ng/mL). Among samples taken from the mother, nicotine and its metabolites were found mainly in urine and also in saliva and hair, but not in cord blood. During the postpartum period, we found cotinine concentrations of 2.2 ng/mL in the mother's urine and 0.22 ng/mL in breast milk; 1,2-propanediol was generally detected in urine and saliva, but not in cord blood or breast milk. The maximum urinary cotinine concentration in the 3-year-old child was 2.6 ng/mL and propanediols also were detected in his urine. Nitrosamines were not detected in samples taken from the mother or the 3-year-old. Metals found in the refill liquid were detected at low levels in both the mother and the 3-year-old. CONCLUSIONS: We detected low but not negligible concentrations of e-cigarette-related analytes (including cord blood and breast milk) in an exposed pregnant non-user and in a 3-year-old child also living in the home. Passive exposure to e-cigarette aerosols cannot be disregarded and should be assessed in larger observational studies.

Association between serum copper levels and risk of cardiovascular disease: A nested case-control study in the PREDIMED trial.

BACKGROUND AND AIM: Certain trace elements have been associated with increased cardiovascular risk. The aim of this study was to evaluate the association between serum copper (S-Cu) levels and the risk of a first event of cardiovascular disease (CVD) in a population of older adults with high cardiovascular risk. METHODS AND RESULTS: We conducted a case-control study nested within the PREDIMED trial. During a median follow-up of 4.8 years, a total of 207 incident cases diagnosed with CVD were matched for sex, age, and intervention group with 436 controls. Personal interviews, reviews of medical records, and validated questionnaires were used to assess known CVD risk factors. Biological serum samples were collected annually. Inductively coupled plasma mass spectrometry analysis was used to determine S-Cu levels. Adjusted odds ratios were calculated using multivariate conditional logistic regression models. All participants had S-Cu levels within the reference values, 750 µg/L to 1450 µg/L. Among men, but not among women, the mean S-Cu concentration was higher in cases 1014.1 µg/L than in controls 959.3 µg/L; (p = 0.004). In men, the multivariable-adjusted odds ratio for CVD was 2.36 (95% CI 1.07-5.20 for the comparison of the highest vs. the lowest quartile; p for trend = 0.02), in women, it was 0.43 (95% CI 0.11-1.70; p for trend = 0.165). CONCLUSION: In older Spanish men with high cardiovascular risk, a significant association was observed between high S-Cu levels, but still within the reference values, and an increased risk of a first event of CVD. Our findings suggest a sex difference in CVD risk and S-Cu levels. To confirm this relationship and to analyze the differences observed between men and women, further studies are needed.

Bleeding and thrombotic complications and their impact on mortality in patients supported with left ventricular assist device for cardiogenic shock.

INTRODUCTION: Thrombosis and bleeding are major complications in patients supported with left ventricular assist devices (LVADs). We aimed to assess the incidence of bleeding and thrombosis in patients supported with a HeartWare left ventricular assist device (HVAD), their predictive factors and their impact on mortality. METHODS: A single centre retrospective observational study of patients supported with HVAD over 5 years from January 2015 to October 2020. RESULTS: A total 139 patients (median age 52.5, 72.1% male) were included for analysis. The probability of 1-year survival was 73.1%. Advanced age (>60 years) and EuroSCORE II score (>20%) were independently associated with reduced survival. Major bleeding and thrombosis occurred in 46.8% and 35.3% respectively. Secondary mechanical circulatory support (MCS) increased likelihood of experiencing major bleeding (HR: 2.76, 95%1.65-4.62, p < 0.0001) whilst patients receiving aspirin were protected from bleeding and thrombosis (HR: 0.34 95% CI 0.19-0.58, p < 0.001). Pre-operative anaemia (HR: 3.02, 95% CI: 1.6-5.7, p = 0.014) and use of a secondary MCS device (HR: 2.78, 95% CI: 1.2-6.3, p = 0.001) were associated with an increased risk of thrombosis. Patients with any major bleeding (with or without thrombosis) had a 7.68-fold (95% CI 3.5-16.8) increased risk of death compared to those without. In contrast, 'thrombosis only' patients had 4.23-fold (95% CI 1.8-10.2) increased risk of death compared to those without thrombosis. The risk of mortality was increased in patients with any thrombosis and the risk of death was highest in patients with major bleeding and thrombosis (HR: 16.49 [95% CI 7.7-35.3]). CONCLUSIONS: Major bleeding and thrombosis significantly increase the 1-year mortality. Optimal perioperative haemostasis and anticoagulation remains crucial in patients supported with HVAD.

Serial macromolecular crystallography at ALBA Synchrotron Light Source.

The increase in successful adaptations of serial crystallography at synchrotron radiation sources continues. To date, the number of serial synchrotron crystallography (SSX) experiments has grown exponentially, with over 40 experiments reported so far. In this work, we report the first SSX experiments with viscous jets conducted at ALBA beamline BL13-XALOC. Small crystals (15-30 µm) of five soluble proteins (lysozyme, proteinase K, phycocyanin, insulin and α-spectrin-SH3 domain) were suspended in lipidic cubic phase (LCP) and delivered to the X-ray beam with a high-viscosity injector developed at Arizona State University. Complete data sets were collected from all proteins and their high-resolution structures determined. The high quality of the diffraction data collected from all five samples, and the lack of specific radiation damage in the structures obtained in this study, confirm that the current capabilities at the beamline enables atomic resolution determination of protein structures from microcrystals as small as 15 µm using viscous jets at room temperature. Thus, BL13-XALOC can provide a feasible alternative to X-ray free-electron lasers when determining snapshots of macromolecular structures.

Serial macromolecular crystallography at ALBA Synchrotron Light Source. Erratum.

A revised version of Table 2 of Martin-Garcia et al. [J. Synchrotron Rad. (2022). 29, 896-907] is provided.

Prognostic impact of changes in aortic stiffness for cardiovascular and mortality outcomes in individuals with type 2 diabetes: the Rio de Janeiro cohort study.

BACKGROUND: The prognostic importance of changes in aortic stiffness for the occurrence of adverse cardiovascular outcomes and mortality has never been investigated in patients with type 2 diabetes. We aimed to evaluate it in a cohort of 417 patients. METHODS: Changes in aortic stiffness were assessed by 2 carotid-femoral pulse wave velocity (CF-PWV) measurements performed over a 4-year period. Multivariable Cox analysis examined the associations between changes in CF-PWV, evaluated as a continuous variable with splines and as categorical ones (quartiles and stable/reduction/increase subgroups), and the occurrence of total cardiovascular events (CVEs), major adverse CVEs (MACEs), and all-cause and cardiovascular mortality. RESULTS: Over a median follow-up of 8.2 years after the 2nd CF-PWV measurement, there were 101 total CVEs (85 MACEs) and 135 all-cause deaths (64 cardiovascular). As a continuous variable, the lowest risk nadir was at -2.5%/year of CF-PWV change, with significantly higher risks of mortality associated with CF-PWV increases, but no excess risks at extremes of CF-PWV reduction. Otherwise, in categorical analyses, patients in the 1st quartile (greatest CF-PWV reductions) had excess risks of all-cause and cardiovascular mortality (hazard ratios [HRs]: 2.0-2.7), whereas patients in 3rd quartile had higher risks of all outcomes (HRs: 2.0-3.2), in relation to the lowest risk 2nd quartile subgroup. Patients in the 4th quartile had higher risks of all-cause mortality. Categorization as stable/reduction/increase subgroups was confirmatory, with higher risks at greater reductions (HRs: 1.7-3.3) and at greater increases in CF-PWV (HRs: 1.9-3.4), in relation to those with stable CF-PWV. CONCLUSIONS: Changes in aortic stiffness, mainly increases and possibly also extreme reductions, are predictors of adverse cardiovascular outcomes and mortality in individuals with type 2 diabetes.

CT angiography for diagnosis of carotid near-occlusion: a digital subtraction angiography validation study.

INTRODUCTION: Carotid near-occlusion (CNO) is a variant of severe stenosis where there is a distal luminal collapse of the internal carotid artery (ICA) beyond a tight stenosis. This study aimed to validate new visual extracranial diagnostic CT angiography (CTA) criteria, for the diagnosis of CNO. The new criteria include distal ICA diameter smaller than contralateral ICA and distal ICA diameter less than or equal to the ipsilateral external carotid artery (ECA). We also assessed the previously described CTA criteria: stenosis ≤ 1.3 mm, ipsilateral distal ICA ≤ 3.5 mm, ipsilateral distal ICA/contralateral distal ICA ratio ≤ 0.87, ipsilateral distal ICA/ipsilateral ECA ≤ 1.27. METHODS: Fifty-eight patients with ICA stenosis (including the near-occlusion variant) or occlusion on digital subtraction angiography (DSA) were included. These patients had DSA and CTA studies completed within 30 days of each other. DSA was considered the reference test. Two neuroradiologists blinded to the DSA results assessed the CTA images and evaluated the new and previously published CNO diagnostic criteria. RESULTS: Twenty-eight CNO were identified with DSA. The "distal ICA diameter less than or equal to the ipsilateral ECA" criterion had 79% sensitivity and 83% specificity with excellent interobserver agreement (kappa = 0.80), while three or more of the previously published criteria reached 82% sensitivity and 90% specificity, with a good interobserver agreement (kappa = 0.64). CONCLUSIONS: CT angiography may be useful for CNO diagnosis. The new visual diagnostic criteria provide acceptable results of sensitivity and specificity with an excellent interobserver agreement. However, false-negative and positive results persist.

Cadmium exposure and growth differentiation factor-15 (GDF-15) levels in non-smoking older adults.

BACKGROUND: Cadmium (Cd) exposure is a risk factor for cardiovascular disease (CVD); however, understanding the effects of Cd at the cellular level remains incomplete. Since growth differentiation factor-15 (GDF-15) is a cytokine produced in many cell types in response to tissue injury and inflammation that may capture several pathways between Cd and CVD, this study examined the relationship between blood Cd levels and serum GDF-15 concentrations in community-dwelling older adults. METHODS: Cd and GDF-15 were measured in 1942 non-smoking individuals aged 65+ with no previous history of CVD. The association of Cd with GDF-15 was evaluated in linear regression models that adjusted for sociodemographic, lifestyle and biological risk factors, inflammatory biomarkers (IL-6, C-reactive protein and neutrophil to lymphocyte ratio), and markers of vascular damage (NTproBNP and cTnT-hs). RESULTS: Geometric mean Cd exposure was 0.11 µg/L (0.09 in never- and 0.15 in former-smokers) and geometric mean GDF-15 was 1186.21 pg/mL (1182.67 in never- and 1191.66 in former-smokers). In multivariable analyses, we found a dose-response association between Cd levels and GDF-15: adjusted mean percentage differences in GDF-15 (95% confidence interval) per 2-fold increase in Cd concentrations in the overall non-smoking population and in never smokers were, respectively, 2.54% (1.01, 4.06) and 2.50% (0.47, 4.54). In spline regression, the dose-response relationship was progressive over the range of Cd concentrations with no significant departures from linearity. CONCLUSIONS: Cd exposure may be related to enhanced GDF-15 expression. Future studies with repeated GDF-15 measurements should confirm the present findings to better understand the biological mechanisms underlying this association.

Metal exposure and biomarker levels among e-cigarette users in Spain.

The use of electronic cigarettes (e-cigarettes) has increased due to the belief that they are healthier than tobacco cigarettes. E-cigarettes contain a metallic heating coil (composed of Ni, Cr, Al and other metals) to heat a solution (commonly called e-liquid) and convert it into an aerosol. This aerosol is inhaled (vaped) by the users who can be potentially exposed to a wide variety of metals. We investigated the possible transfer of metals from the coil to the e-liquid and the generated aerosol, and how the exposure to this aerosol can increase metal body burden in e-cigarette users. We recruited 75 e-cigarette users (50 who only vaped and 25 dual users who vaped and smoked) and 25 controls who neither vaped nor smoked. E-liquid samples before (dispenser e-liquid) and after (tank e-liquid) being added to their devices were collected. Aerosol samples were collected using a condensation method. All participants provided urine and hair samples. All samples were analyzed for metals by ICP-MS. We observed higher metal concentrations in the aerosol and tank e-liquid (in contact with the coil) compared to the dispenser e-liquid (before contact with the coil). The median concentrations for some of the metals with the most remarkable increases in aerosol and tank e-liquid vs. dispenser e-liquid were 36.90 and 62.73 vs. 18.29 µg/kg for Al; 6.71 and 28.97 vs. 0.98 µg/kg for Cr; 91.39 and 414.47 vs. 1.64 µg/kg for Ni; 738.99 and 744.24 vs. 16.56 µg/kg for Zn; and 10.17 and 22.31 vs. 0.88 µg/kg for Pb. We also found detectable and potentially high concentrations of other metals such as Mn, Cu, Sb and Sn. In urine, increases in the median levels (µg/g creatinine) in vapers/duals vs. controls were observed for some metals, including Cr (0.34/0.28 vs. 0.20), Cu (1.72/2.36 vs. 1.46), Sn (0.26/0.31 vs. 0.18) and Pb (0.39/0.44 vs. 0.22). In hair, there were no differences in metal concentrations among the three groups. In conclusion, e-cigarettes are likely a source of metals such as Cr, Cu, Ni, Pb or Sn. These metals come from the device, likely the heating resistance, as their concentrations were low in the dispenser e-liquid and higher in the aerosol and the e-liquid left in the tank. Although the exposure to e-cigarette aerosol can have an influence in the body burden of metals, aerosol metal levels were not clearly associated with metal levels in biological samples such as urine or hair in e-cigarette users in this study.

The cis-encoded antisense RNA IsrA from Salmonella Typhimurium represses the expression of STM0294.1n (iasE), an SOS-induced gene coding for an endoribonuclease activity.

Toxin-antitoxin systems are known to be involved in many bacterial functions that can lead to growth arrest and cell death in response to stress. Typically, toxin and antitoxin genes of type I systems are located in opposite strands, where the antitoxin is a small antisense RNA (sRNA). In the present work we show that the sRNA IsrA from Salmonella Typhimurium down-regulates the expression of its overlapping gene STM0294.1n. Multiple sequence alignment and comparative structure analysis indicated that STM0294.1n belongs to the SymE toxin superfamily, and the gene was renamed iasE (IsrA-overlapping gene with similarity to SymE). The iasE expression was induced in response to mitomycin C, an SOS-inducing agent; conversely, IsrA overexpression repressed the iasE expression even in the presence of mitomycin C. Accordingly, the inactivation of IsrA with an anti-IsrA RNA expressed in trans abrogated the repressive effect of IsrA on the iasE expression. On the other hand, iasE overexpression, as well as the blockage of the antisense IsrA function, negatively affected bacterial growth, arguing for a toxic effect of the iasE gene product. Besides, a bacterial lysate obtained from the iasE-overexpressing strain exhibited endoribonuclease activity, as determined by a fluorometric assay based on fluorescent reporter RNAs. Together, these results indicate that the IasE/IsrA pair of S. Typhimurium constitutes a functional type I toxin-antitoxin system.

Clostridium difficile exosporium cysteine-rich proteins are essential for the morphogenesis of the exosporium layer, spore resistance, and affect C. difficile pathogenesis.

Clostridium difficile is a Gram-positive spore-former bacterium and the leading cause of nosocomial antibiotic-associated diarrhea that can culminate in fatal colitis. During the infection, C. difficile produces metabolically dormant spores, which persist in the host and can cause recurrence of the infection. The surface of C. difficile spores seems to be the key in spore-host interactions and persistence. The proteome of the outermost exosporium layer of C. difficile spores has been determined, identifying two cysteine-rich exosporium proteins, CdeC and CdeM. In this work, we explore the contribution of both cysteine-rich proteins in exosporium integrity, spore biology and pathogenesis. Using targeted mutagenesis coupled with transmission electron microscopy we demonstrate that both cysteine rich proteins, CdeC and CdeM, are morphogenetic factors of the exosporium layer of C. difficile spores. Notably, cdeC, but not cdeM spores, exhibited defective spore coat, and were more sensitive to ethanol, heat and phagocytic cells. In a healthy colonic mucosa (mouse ileal loop assay), cdeC and cdeM spore adherence was lower than that of wild-type spores; while in a mouse model of recurrence of the disease, cdeC mutant exhibited an increased infection and persistence during recurrence. In a competitive infection mouse model, cdeC mutant had increased fitness over wild-type. Through complementation analysis with FLAG fusion of known exosporium and coat proteins, we demonstrate that CdeC and CdeM are required for the recruitment of several exosporium proteins to the surface of C. difficile spores. CdeC appears to be conserved exclusively in related Peptostreptococcaeace family members, while CdeM is unique to C. difficile. Our results sheds light on how CdeC and CdeM affect the biology of C. difficile spores and the assembly of the exosporium layer and, demonstrate that CdeC affect C. difficile pathogenesis.

Association of urinary metal concentrations with blood pressure and serum hormones in Spanish male adolescents.

OBJECTIVE: To examine the association of urinary concentrations of arsenic (As), cadmium (Cd), mercury (Hg), nickel (Ni), lead (Pb), manganese (Mn), and chromium (Cr) with blood pressure (BP) and serum hormone levels in male adolescents. METHODS: Participants were selected from the INMA (Environment and Childhood)-Granada cohort at their follow-up visit when aged 15-17 years. Metal concentrations were measured in urine samples using inductively coupled plasma mass spectrometry. Outcomes were BP measurements (systolic, diastolic, and pulse pressure) recorded during the visit and concurrent serum levels of thyroid hormones, sex hormones, and adrenal hormones. Associations were assessed by regression analysis in a sub-sample of 133 boys with available data on urinary metals, outcomes, and relevant covariates. RESULTS: Models simultaneously adjusted for all metals and other potential confounders showed that urinary As and Cd were both associated with slight elevations in systolic BP (0.70 mmHg, 95%CI = 0.11; 1.29 and 1.47, 95%CI = 0.30; 2.63, respectively, per each 50% increase in metal concentrations), and urinary As was also associated with an increased risk of elevated systolic BP (≥120 mmHg) (OR = 1.28, 95%CI = 1.04; 1.56). The presence of detectable levels of 4 and 5 versus 2-3 non-essential metals (As, Cd, Hg, Ni, Pb) per boy was associated with elevations in systolic BP of 5.84 mmHg (95%CI = 0.40; 11.3) and 7.01 mmHg (95%CI = 1.01; 13.0), respectively (p-trend = 0.05). Significant associations were also found between Hg and increased testosterone and luteinizing hormone (LH) and decreased thyroid-stimulating hormone (TSH); between the combination of As and Hg and increased LH and insulin-like growth factor 1; between Cr and decreased TSH; and between Cd and increased adrenocorticotropic hormone. CONCLUSIONS: These findings suggest that combined exposure to toxic metals, especially As and Cd, may contribute to BP elevation in male adolescents and that exposure to Hg, As, Cd, and Cr may affect their hormone levels.

Heparin Attenuates Visceral Apoptosis in a Swine Model of Hemorrhagic Shock and Reperfusion Injury.

BACKGROUND: The use of unfractionated heparin in hypovolemic shock, aortic clamping, and visceral reperfusion is still not established, despite evidence of inhibition of early cell damage. This study investigated the potential protective effect of unfractionated heparin on hepatic and renal apoptosis in a porcine ischemia and reperfusion model. METHODS: Twenty-one male swine (Sus scrofa) were divided into 3 groups: sham (n = 5), heparin (n = 8), and nonheparin (n = 8). The heparin and nonheparin groups underwent hypovolemic shock for 30 min, supraceliac aortic clamping for 1 h and reperfusion for 3 h. Unfractionated heparin 200 mg/kg was administered to the heparin group during aortic clamping. Hemodynamic and laboratory parameters were monitored, including aminotransferase and serum urea. Histological lesion scores were applied to hematoxylin and eosin-stained liver and kidney sections. Apoptosis quantification was performed by caspase-3 immunohistochemistry. RESULTS: The proposed model caused a severe cardiocirculatory disturbance in the heparin and nonheparin groups, observed by the carotid-femoral pressure gradient and lactic acidosis. There was no significant difference in hemodynamic and laboratory parameters between these two groups. The mean values of liver and renal histological lesion scores did not present any significant differences. Caspase-3 immunoexpression was lower in the heparin than the nonheparin group for both liver and kidney. CONCLUSIONS: Attenuation of liver and kidney cell apoptosis in pigs undergoing systemic heparinization suggests a potential use for heparin in modulating cell death under critical hemodynamic conditions.

Effect of antibiotic to induce Clostridioides difficile-susceptibility and infectious strain in a mouse model of Clostridioides difficile infection and recurrence.

The anaerobic bacterium Clostridioides difficile is the leading cause of antibiotic-associated diarrhea that can culminate in life-threating colitis. During the C. difficile infection (CDI), C. difficile produces toxins that generate the clinical symptoms of the disease, and produce spores, which persist in the host during antibiotic treatment and can cause recurrent CDI (R-CDI). In this work, we aimed to compare three antibiotic regimens in the susceptibility of mice to CDI and R-CDI (i.e., antibiotic cocktail followed by clindamycin, 5 days of cefoperazone and 10 days of cefoperazone) with three different C. difficile isolates (i.e., strains 630; R20291, and VPI 10463). We observed that the severity of the clinical symptoms of CDI and R-CDI was dependent on the antibiotic treatment used to induce C. difficile-susceptibility, and that the three strains generated a different onset to diarrhea and weight loss in mice that were administrated with the same antibiotic treatment and which differed in comparison to the effect previously reported by other research groups. Our results suggest that, in our experimental conditions, in those animals treated with antibiotic cocktail followed by clindamycin, infection with strain R20291 had the highest diarrhea manifestation in comparison to strains 630 and VPI 10463. In animals treated with cefoperazone for 5 days, infection with strains R20291 or 630 had the highest diarrhea manifestation in comparison to VPI 10463, while in animals treated with cefoperazone for 10 days, infection with strain R20291 or VPI 10463, but not 630, had the highest diarrhea manifestation.

Biomarkers of oxidative stress in blood of workers exposed to non-cholinesterase inhibiting pesticides.

In occupational settings workers are often exposed to pesticides at relatively high doses compared to environmental exposures. Long-term exposure to pesticides has been associated with numerous adverse health effects in epidemiological studies, and oxidative stress is often claimed as one of the underlying mechanisms. In fact, different pesticides have been reported to induce oxidative stress due to the generation of free radicals and/or alteration in antioxidant defense enzymes. The present study examined greenhouse workers regularly exposed to diverse pesticides under integrated production system, and a group of controls of the same geographic area without any chemical exposure. Two different periods of the same crop season were assessed, one of high exposure (with greater use of pesticides) and other of low exposure (in which a less use of these compounds was made). Non-specific biomarkers of oxidative stress, e.g. thiobarbituric acid reactive substances (TBARS), ferric reducing ability of serum (FRAS), total thiol groups (SHT), gamma-glutamyl transpeptidase (GGT) and paraoxonase-1 (PON1) were measured in serum samples from all study subjects, alongside erythrocyte acetylcholinesterase (AChE). Results are suggestive of a mild increase in oxidative stress associated with pesticide exposure, which was compensated by an adaptive response to raise the antioxidant defenses and thus counter the detrimental effects of sustained oxidative stress. This response led to significantly increased levels of FRAS, SHT and PON1 in greenhouse workers relative to controls. Furthermore, AChE was decreased likely as a result of oxidative stress as workers did not use organophosphate insecticides.

Toxicological interactions of pesticide mixtures: an update.

Pesticides can interact with each other in various ways according to the compound itself and its chemical family, the dose and the targeted organs, leading to various effects. The term interaction means situations where some or all individual components of a mixture influence each other's toxicity and the joint effects may deviate from the additive predictions. The various mixture effects can be greatly determined by toxicokinetic and toxicodynamic factors involving metabolic pathways and cellular or molecular targets of individual pesticides, respectively. However, the complexity of toxicological interactions can lead to unpredictable effects of pesticide mixtures. Interactions on metabolic processes affecting the biotransformation of pesticides seem to be by far the most common mechanism of synergism. Moreover, the identification of pesticides responsible for synergistic interactions is an important issue for cumulative risk assessment. Cholinesterase inhibiting insecticides (organophosphates and N-methylcarbamates), triazole fungicides, triazine herbicides, and pyrethroid insecticides are overrepresented in the synergistic mixtures identified so far. Since the limited available empirical evidence suggests that synergisms at dietary exposure levels are rather rare, and experimentally occurred at unrealistic high concentrations, synergism cannot be predicted quantitatively on the basis of the toxicity of mixture components. The prediction of biological responses elicited by interaction of pesticides with each other (or with other chemicals) will benefit from using a systems toxicology approach. The identification of core features of pesticide mixtures at molecular level, such as gene expression profiles, could be helpful to assess or predict the occurrence of interactive effects giving rise to unpredicted responses.

Updates on Clostridium difficile spore biology.

Clostridium difficile is a Gram-positive, anaerobic spore former, and an important nosocomial pathogenic bacterium. C. difficile spores are the morphotype of transmission and recurrence of the disease. The formation of C. difficile spores and their subsequent germination are essential processes during the infection. Recent in vitro and in vivo work has shed light on how spores are formed and the timing of in vivo sporulation in a mouse model. Advances have also been made in our understanding of the machineries involved in spore germination, and how antibiotic-induced dysbiosis affects the metabolism of bile salts and thus impacts C. difficile germination in vivo. Studies have also attempted to identify how C. difficile spores interact with the host's intestinal mucosa. Spore resistance has also been revisited by several groups highlighting the extreme resistance of this morphotype to traditional food processing regimes and disinfectants used in clinical settings. Therefore, the aim of this review is to summarize recent advances on spore formation/germination in vitro and in vivo, spore-host interactions, and spore resistance that contribute to our knowledge of the role of C. difficile spores in the infectious process.

The evolution of gerontology and geriatrics in an era of a politics of aging.

The fields of gerontology and geriatrics are facing unprecedented changes, pressures, and opportunities. The 21st century requires that we utilize contemporary approaches to modernizing these disciplines for new populations, new cohorts and new social, economic and political demands. This article draws on the authors professional, academic, and public policy experiences to suggest initiatives and paradigms that can set a road map to both change the last centuries' notions of longevity and social supports to one that accounts for technology, varied cohorts, a public/private sector divide, and the nexus of aging and diversity.