Genotype characterization and phylogenetic analysis of hepatitis B virus isolates from Iranian patients

Hepatitis B virus (HBV) is one of the major causative agents of acute and chronic liver disease worldwide and is believed to be responsible for a million deaths annually. Eight genotypes of HBV, A to H, have been described on the basis of similarity of the complete genomes sequence. Although, it is reported that the predominant HBV genotype in the Mediterranean area and the middle east is genotype D, there are no reports on HBV genotypes prevalent in Iran. In this study, the C and S regions of HBV from 26 chronic hepatitis B Iranian patients were amplified and sequenced. Phylogenetic analysis revealed that all Iranian HBV isolates sequences were classified into genotype D with bootstrap values of 100%, 73%, and 100% (1,000 replicates each) for S, C, and preS2 regions, respectively. The mean percent intra-distance of S and C regions were 0.8% and 2.3%, respectively. The mean percent inter-distance of S and C regions between Iranians and genotype D isolates were 1.7% and 3.0%, respectively, and the range of mean percent nucleotide distance of S and C regions between Iranians and the other reference isolates were 7.9%-17.5% and 4.8%-14.7%, respectively. Thirteen out of 23 HBV C region sequences showed nucleotide "A" at position 1896 (precore mutant) in C region. Nucleotide 1858 showed presence of "T" in all isolates. No insertion or deletion was found in both regions. SimPlot and BootScanning analyses did not show any recombination between Iranian isolates and other genotypes in both regions.     

Treatment with atorvastatin ameliorates hepatic very-low-density lipoprotein overproduction in an animal model of insulin resistance, the fructose-fed Syrian golden hamster: evidence that reduced hypertriglyceridemia is accompanied by improved hepatic insulin sensitivity

A novel animal model of insulin resistance, the fructose-fed Syrian golden hamster has been previously documented to exhibit considerable hepatic very-low-density lipoprotein (VLDL) overproduction concomitant with the development of whole body insulin resistance. Here, we investigated whether hepatic lipoprotein overproduction can be ameliorated by treatment with a hydroxymethyl glutaryl conenzyme A (HMG-CoA) reductase inhibitor, atorvastatin, using a series of ex vivo experiments. Hamsters were fed a fructose-enriched diet for 14 days to induce a state of insulin resistance, and then continued on a fructose-enriched diet supplemented with or without 40 mg/kg atorvastatin per day for 14 days. Fructose feeding in the first 2 weeks caused a significant increase in plasma total cholesterol and triglyceride levels. There was a significant decline in plasma triglyceride levels following supplementation with the inhibitor (50% to 59%; P <.05). Experiments with primary hepatocytes revealed a decreased VLDL-apolipoprotein B (apoB) production (37.4% +/- 10.4%; P <.05) in hamsters treated with atorvastatin. Interestingly, atorvastatin treatment partially attenuated (by 23%) the elevated hepatic level of microsomal triglyceride transfer protein (MTP) induced by fructose feeding. There was molecular evidence of improved hepatic insulin sensitivity with atorvastatin treatment based on assessment of the phosphorylation status of the insulin receptor and the expression of protein tyrosine phosphatase-1B. The improvement in insulin signaling was not mediated by a change in hepatic triglyceride accumulation as no significant difference was observed in liver triglyceride levels. Taken together, these data suggest that statins can ameliorate the VLDL-apoB overproduction state observed in a fructose-fed, insulin-resistant hamster model, and may potentially contribute to an enhanced hepatic insulin sensitivity.     

A Snapshot of Lipid-Reporting Practices in Canadian Clinical Laboratories: An Urgent Need for Harmonisation

To effectively implement the Canadian Cardiovascular Society (CCS) guidelines for dyslipidemia management into clinical laboratories, clear recommendations for lipid reporting are essential. In this study, the Canadian Society of Clinical Chemists Working Group on Reference Interval Harmonisation surveyed Canadian laboratories on adult lipid reporting practices to set a foundation for the development and implementation of harmonised lipid reporting across Canada. Key aspects of the survey asked laboratories: what reporting parameters were in place to assess lipid results; what interpretative comments were provided; whether nonfasting lipids were permitted and, if so, what strategy was used to document fasting status; and whether there was interest in implementing a harmonised lipid report. A total of 101 laboratories were represented by 24 respondents, as many responses were submitted by laboratory networks that included more than 1 laboratory. There was at least 1 response from 9 Canadian provinces and representation across 5 testing platforms. Upper and lower limits for lipid parameters and referenced source of limits varied substantially across laboratories, with only 56% of laboratories (9 respondents) referencing the 2016 CCS guidelines. Eighty-six percent of laboratories (19 respondents) report nonfasting lipids, although the method of documenting nonfasting status varied. Overall, 36% of laboratories (8 respondents) reported interest in implementing a harmonised lipid report. Assessment of current lipid-reporting practices supports the need for harmonised lipid reporting across Canada. Development of a harmonised lipid report for the adult population, consistent with up-to-date Canadian guidelines, will improve continuity of lipid test interpretation across Canada and improve clinical decision making.     

Incidence of cystoid macular oedema with intracameral cephalosporin or vancomycin in cataract surgery

Abstract

Purpose: To compare the incidence of pseudophakic cystoid macular oedema (CME) in patients who receive intracameral cephalosporin versus intracameral vancomycin during cataract surgery.

Methods: A retrospective chart review was conducted on subjects with the diagnosis of CME between January 1 2010 and July 31 2017. Inclusion criterion was the documentation of CME after cataract extraction. Exclusion criteria were intraoperative complication, prior history of macular oedema, epiretinal membrane, uveitis, other pre-existing retinal pathology, or other post-operative pathology including other ocular surgery in the post-operative period.

Results: The final analysis included 89 eyes with optical coherence tomography (OCT) proven CME. The incidence of pseudophakic CME in our population of 10,165 cataract surgeries after applying the above-stated exclusion criteria was 0.88%. The incidence of pseudophakic CME in subjects who received intracameral cephalosporin was 0.87% (mean age in years 69?±?11; 31 male [39%], 48 female [61%]). The incidence of pseudophakic CME in subjects who received intracameral vancomycin was 0.96% (mean age in years 66?±?13; 4 male [40%], 6 female [60%]). Pearson’s chi-square test demonstrated no significant difference between these groups (p?=?0.7705).

Conclusions: There was no statistical difference in the incidence of pseudophakic CME in subjects who received intracameral cephalosporin versus intracameral vancomycin during cataract surgery.     

Intestinal lipoprotein overproduction, a newly recognized component of insulin resistance, is ameliorated by the insulin sensitizer rosiglitazone: studies in the fructose-fed Syrian golden hamster

We investigated whether intestinal lipoprotein overproduction in a fructose-fed, insulin-resistant hamster model is prevented with insulin sensitization. Syrian Golden hamsters were fed either chow, 60% fructose for 5 wk, chow for 5 wk with the insulin sensitizer rosiglitazone added for the last 3 wk, or 60% fructose plus rosiglitazone. In vivo Triton studies showed a 2- to 3-fold increase in the large (Svedberg unit > 400) and smaller (Sf 100-400) triglyceride-rich lipoprotein particle apolipoprotein B48 (apoB48) but not triglyceride secretion with fructose feeding in the fasted state (P < 0.01) and partial normalization with rosiglitazone in fructose-fed hamsters. Ex vivo pulse-chase labeling of enterocytes confirmed the oversecretion of apoB48 lipoproteins with fructose feeding. Intestinal lipoprotein oversecretion was associated with increased expression of microsomal triglyceride transfer protein expression. With rosiglitazone treatment of fructose-fed hamsters, there was approximately 50% reduction in apoB48 secretion from primary cultured enterocytes and amelioration of the elevated microsomal triglyceride transfer protein mass and activity in fructose-fed hamsters. In contrast, in the postprandial state, the major differences between nutritional and drug intervention protocols were evident in triglyceride-rich lipoprotein triglyceride and not apoB48 secretion rates. The data suggest that intestinal lipoprotein overproduction can be ameliorated with the insulin sensitizer rosiglitazone.     

Could Guillain–Barré syndrome be triggered by COVID‐19 vaccination?

Due to SARS‐COV‐2 (COVID‐19) pandemic and its catastrophic impact on society, the FDA granted emergency use authorization for some vaccines. Possible rare side effects could not have been observed in this relatively short period. We are reporting an elderly lady with multiple comorbidities who presented with progressive lower limb weakness that started seven days after receiving the first dose of the COVID‐19 vaccine. The electrodiagnostic study showed demyelinating polyneuropathy with secondary axonal degeneration consistent with Guillain–Barré syndrome. We ruled out other possible causes for GBS, suggesting a postvaccine nature for her presentation. The patient received intravenous immunoglobulin (IVIG) for five days and gradually improved, which supports our initial diagnosis.     

Validity of establishing pediatric reference intervals based on hospital patient data: A comparison of the modified Hoffmann approach to CALIPER reference intervals obtained in healthy children

Objectives

To compare pediatric reference intervals calculated using hospital-based patient data with those calculated using samples collected from healthy children in the community as part of the CALIPER study.

Methods

Hospital-based data for 13 analytes (calcium, phosphate, iron, ALP, cholesterol, triglycerides, creatinine, direct bilirubin, total bilirubin, ALT, AST, albumin and magnesium), measured on the Vitros 5600, collected between 2007 and 2011 were obtained. The data for each analyte were partitioned by age and gender as previously defined by the CALIPER study. Outliers in each partition were removed using the Tukey method. The cumulative distribution function (cdf) was then determined for each analyte value following which, the inverse cdf values of a standard Gaussian distribution were calculated. The analyte values were plotted against the inverse cdf of the standard Gaussian distribution. Piece-wise regression determined the linear portion of the resulting graph using the statistical software R. Linear regression determined an equation for the linear portion in each partition and reference intervals were calculated by extrapolating to identify the 2.5th and 97.5th centiles in each partition based on the inverse cdf values (which would correspond to the values − 1.96 and 1.96 of the Gaussian distribution). Using the 90% confidence intervals for the reference intervals defined by CALIPER and the Reference Change Value (RCV) as the criteria, these calculated reference intervals were compared to those reported previously by CALIPER. Reference samples were also measured on the Vitros 5600 analyzer in an attempt to validate the calculated reference intervals.

Results

In general, the reference intervals calculated from hospital-based data were generally wider than those calculated by CALIPER. None of the reference intervals calculated using the Hoffmann approach fell completely within the 90% confidence intervals calculated by CALIPER.

Conclusions

These results suggest that calculating pediatric reference intervals from hospital-based data may be useful, as a guide, in some cases but will likely not replace the need to establish reference intervals in healthy pediatric populations.     

Protective effects of a magnesium magnetic isotope (Mg25)‐exchanging nanoparticle (25MgPMC16) on mitochondrial functional disorders in esmolol‐induced cardiac arrest in rats

1 In cardiac surgery, agents are needed to produce temporary cardiac arrest (cardioplegia). One of these agents is esmolol (ESM) which is a short‐acting selective beta‐1 adrenergic receptor antagonist and its overdose causes diastolic ventricular arrest. 2 The ²⁵MgPMC₁₆ (porphyrin adducts of cyclohexil fullerene‐C60) is known as a nanoparticle which has a cardioprotective effect when the heart is subjected to stressful conditions. 3 In this study, we aimed to confirm the deleterious effects of ESM overdose on cardiac mitochondria and identify any protective effects of ²⁵MgPMC₁₆ in male Wistar rats. Esmolol 100 mg kg^?1 (LD50 = 71 mg kg^?1) was injected intravenously (i.v.) into tail vein to induce cardiac arrest. This dose was obtained from an ESM dose–response curve which induces at least 80% arrest in rats. 4 ²⁵MgPMC₁₆ at three different doses (45, 90 and 224 mg kg^?1) was injected i.v. as pretreatment, eight hours before ESM injection. ²⁵MgCl₂ or ²⁴MgPMC₁₆ were used as controls. Following cardiac arrest, the heart was removed and the mitochondria extracted. Mitochondrial viability and the adenosine 5′‐diphosphate sodium salt hydrate/Adenosine 5′‐triphosphate disodium salt hydrate (ADP/ATP) ratio were measured as biomarkers of mitochondrial function. 5 Results indicate that ²⁵MgPMC₁₆ caused a significant increase in mitochondrial viability and decrease in ADP/ATP ratio. No significant changes were seen with ²⁴MgPMC₁₆ or ²⁵MgCl₂. It is concluded that cardiac arrest induced by ESM overdose leads to a significant decrease in mitochondrial viability and their ATP levels, whereas pretreatment by ²⁵MgPMC₁₆ can protect mitochondria by increasing ATP level through liberation of Mg into cells and the improvement of hypoxia.     

The chalcone xanthohumol inhibits triglyceride and apolipoprotein B secretion in HepG2 cells

The present study examined the role of xanthohumol (XN), a plant chalcone, on apolipoprotein B (apoB) and triglyceride (TG) synthesis and secretion, using HepG2 cells as the model system. The data indicated that XN decreased apoB secretion in a dose-dependent manner under both basal and lipid-rich conditions (as much as 43% at 15 micromol/L). This decrease was associated with increased cellular apoB degradation. To determine the mechanism underlying this effect, we examined triglyceride availability, a major factor in the regulation of apoB secretion. XN inhibited the synthesis of TG in the microsomal membrane and the transfer of this newly synthesized TG to the microsomal lumen (decreases of 26 and 64%, respectively, under lipid-rich conditions), indicating that TG availability is a determining factor in the regulation of apoB secretion under the experimental conditions. The inhibition of TG synthesis was caused by a reduction in diacylglycerol acyltransferase (DGAT) activity, which corresponded to a decrease in DGAT-1 mRNA expression, but not DGAT-2 expression. Microsomal triglyceride transfer protein (MTP) may also control the rate of TG transfer from the microsomal membrane to the active lumenal pool. XN decreased MTP activity in a dose-dependent manner (as much as 30%). Whether the reduction in TG accumulation in the microsomal lumen is predominantly due to DGAT and/or MTP activity remains unknown. In summary, the data suggest that xanthohumol is a potent inhibitor of apoB secretion.     

Emergence of the metabolic syndrome in childhood: an epidemiological overview and mechanistic link to dyslipidemia

Insulin resistance and type 2 diabetes are rapidly emerging as major disorders of childhood and adolescence. This appears to be closely linked to a rapid rise in the prevalence of obesity in the pediatric population. The development of insulin resistance appears to lead to a "metabolic syndrome" which includes a number of major complications such as dyslipidemia and hypertension. Childhood metabolic syndrome promotes the development of premature atherosclerosis and significantly increases cardiovascular disease risk early in life. The mechanisms linking obesity, insulin resistance, and metabolic dyslipidemia are not fully understood. This review will attempt to discuss some of the key mechanistic issues surrounding insulin resistance and its association with metabolic dyslipidemia. Most of the recent progress in this field has come from the use of genetic and diet-induced animal models of insulin resistance. New data from these animal studies particularly the fructose-fed hamster, a model of metabolic syndrome and dyslipidemia, will be reviewed. Evidence from both animal and human studies suggest a key role for insulin sensitive tissues such as adipose tissue, liver, and intestine in the development of an insulin resistant state and its associated lipid and lipoprotein disorders. The critical interaction of metabolic signals among these tissues appears to govern the transition from an insulin sensitive to an insulin resistant state that underlies dyslipidemic conditions.