Publications by authors named "Vollrath V"

spp. is an emerging cause of infectious diarrhea worldwide. In South American countries such as Chile, its prevalence is underestimated due to inadequate detection methods.

View Article and Find Full Text PDF

Background:: A poor or unhealthy diet is responsible for an important fraction of ischemic stroke risk. Adherence to dietary patterns, such as the Mediterranean diet, rich in monounsaturated fatty acids mainly from olive oil, is associated with a lower stroke risk. Furthermore, lowering low-density cholesterol (LDL-C) levels decreases stroke recurrence.

View Article and Find Full Text PDF

Background: Real-Time Reverse-Transcription Polymerase Chain Reaction (RT-PCR) is currently the only recommended diagnostic method for SARS-CoV-2. However, rapid immunoassays for SARS-CoV-2 antigen could significantly reduce the COVID-19 burden currently weighing on laboratories around the world.

Methods: We evaluated the performance of two rapid fluorescence immunoassays (FIAs), SOFIA SARS Antigen FIA (Quidel Corporation, San Diego, CA, USA) and STANDARD F COVID-19 Ag FIA (SD Biosensor Inc.

View Article and Find Full Text PDF

Acute respiratory infections (ARI) are an important cause of morbidity and mortality worldwide, affecting mainly children and the elderly. They are associated with a high economic burden, increased number of medical visits and hospitalizations. The surveillance of the circulation of respiratory viruses can reduce the health care associated costs, and to optimize the health response.

View Article and Find Full Text PDF

Objectives: In the context of the coronavirus disease 2019 (COVID-19) pandemic, the development and validation of rapid and easy-to-perform diagnostic methods are of high priority. This study was performed to evaluate a novel rapid antigen detection test (RDT) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in respiratory samples.

Methods: The fluorescence immunochromatographic SARS-CoV-2 antigen test (Bioeasy Biotechnology Co.

View Article and Find Full Text PDF

Invasive amoebiasis is a life-threatening infection requiring immediate detection and treatment. However, diagnosis is challenging because conventional methods such as light microscopy and serology are unreliable. Molecular techniques are therefore considered the new diagnostic reference standard, but most of the developed assays are research tools and not widely available.

View Article and Find Full Text PDF

Background: Thiopurines (azathioprine and 6-mercaptopurine) are highly effective medications but with potential adverse effects. Thiopurine methyltransferase (TMPT) is the key enzyme in their pharmacokinetics and is genetically regulated. A low activity of TPMT is associated with myelotoxicity.

View Article and Find Full Text PDF

Background: The plasminogen activator inhibitor type-1 (PAI-1) has been implicated in the regulation of fibrinolysis and extracellular matrix components. The single base pair guanine insertion/deletion polymorphism (4G/5G) within the promoter region of the PAI-1 gene influences PAI-1 synthesis and may modulate hepatic fibrogenesis.

Aim: To evaluate the influence of PAI-1 serum levels and 4G/5G polymorphism on the risk of liver fibrosis associated to non-alcoholic fatty liver disease (NAFLD) in morbidly obese patients.

View Article and Find Full Text PDF

The HCV internal ribosome entry site (IRES) spans a region of approximately 340 nt that encompasses most of the 5' untranslated region (5'UTR) of the viral mRNA and the first 24-40 nt of the core-coding region. To investigate the implication of altering the primary sequence of the 5'UTR on IRES activity, naturally occurring variants of the 5'UTR were isolated from clinical samples and analyzed. The impact of the identified mutations on translation was evaluated in the context of RLuc/FLuc bicistronic RNAs.

View Article and Find Full Text PDF

HCV is primarily hepatotropic, but there is mounting evidence pointing to infection and replication of extrahepatic sites. Here we evaluated the occurrence of HCV infection of peripheral blood mononuclear cells (PBMC) and explored the possible association between viral extrahepatic infection and the natural history of the disease. Forty seven Chilean, HCV infected, treatment naïve patients were included in the study.

View Article and Find Full Text PDF

The properties of bucillamine, a synthetic antioxidant, have been attributed mainly to the donation of thiol groups to glutathione (GSH). We recently demonstrated that glutamate-cysteine ligase catalytic subunit (GCLC), the rate-limiting enzyme of GSH biosynthesis, and the multidrug-resistance-associated protein 2 (Mrp2/MRP2) are coordinately induced in response to xenobiotic through the activation of the antioxidant-response element (ARE) by nuclear factor-erythroid 2 p45-related factor (Nrf2). We tested the hypothesis that bucillamine and its oxidized metabolite SA 981 also activate the Nrf2 pathway, thereby increasing glutathione biosynthesis in human HepG2 and murine Hepa 1-6 hepatoma cell lines, through the induction of the GCLC enzyme as well as the Mrp2/MRP2 transporter, which mediates the excretion of glutathione and its conjugates from hepatocytes.

View Article and Find Full Text PDF

Purpose: To study the C(-106)T polymorphism in the promoter of the aldose reductase (ALR2) gene: (a) its local prevalence and (b) its modulation of the susceptibility for developing retinopathy.

Methods: DNAs of 96 control subjects and 53 long-standing (duration 17.9+/-5.

View Article and Find Full Text PDF

The Nrf2 (nuclear factor-erythroid 2 p45-related factor 2) transcription factor regulates gene expression of the GCLC (glutamate-cysteine ligase catalytic subunit), which is a key enzyme in glutathione synthesis, and GSTs (glutathione S-transferases) via the ARE (antioxidant-response element). The Mrp2 (multidrug-resistance protein 2) pump mediates the excretion of GSH and GSSG excretion as well as endo- and xeno-biotics that are conjugated with GSH, glucuronate or sulphate. Considering that Mrp2 acts synergistically with these enzymes, we hypothesized that the regulation of Mrp2 gene expression is also dependent on Nrf2.

View Article and Find Full Text PDF

Background: There are significant differences in drug responses among different ethnic groups. The multidrug transporter P-gp, encoded by the MDR1 gene, plays a key role in determining drug bioavailability, and an association between a polymorphism in exon 26 (C3435T) and lower P-gp expression has been found. The co-segregation of this polymorphism with the polymorphism in exon 12 (C1236T) and in exon 21 (G2677T/A) determines several MDR1 haplotypes in humans.

View Article and Find Full Text PDF

Extracellular adenosine triphosphate (ATP) may regulate hepatocyte and cholangiocyte functions, and under some conditions it may have deleterious effects on bile secretion and cause cholestasis. The canalicular membrane enzyme Ca2+/Mg2+-ecto-ATPase (ecto-ATPase) hydrolyzes ATP/adenosine diphosphate (ATP/ADP) and regulates hepatic extracellular ATP concentration. Changes in liver ecto-ATPase in estrogen-induced cholestasis were examined in male rats receiving 17alpha-ethinylestradiol (E groups) for 1, 3, or 5 days (5 mg/kg/day, sc) and compared with changes in rats subjected to obstructive cholestasis (O groups) for 1, 3, or 8 days.

View Article and Find Full Text PDF

A recent case-control study suggests that the allele (AC)23 of a variable number tandem repeat (VNTR) associated to the aldose reductase (ALR2) gene could be related to early retinopathy in Type 2 diabetics. By means of a longitudinal-retrospective study, we aimed to seek for a relationship between the rate of progression of retinopathy and the (AC)23 allele of the VNTR associated to the ALR2 gene. A random sample was obtained of 27 Type 2 diabetics (aged 68.

View Article and Find Full Text PDF

Background: Recent studies suggest that polymorphisms associated to the aldose reductase gene could be related to early retinopathy in noninsulin dependent diabetics (NIDDM). There is also new interest on the genetic modulation of coagulation factors in relation to this complication.

Aim: To look for a possible relationship between the rate of appearance of retinopathy and the genotype of (AC)n polymorphic marker associated to aldose reductase gene.

View Article and Find Full Text PDF

The canalicular multispecific organic anion transporter, cMoat, is an ATP-binding-cassette protein expressed in the canalicular domain of hepatocytes. In addition to the transport of endo- and xenobiotics, cMoat has also been proposed to transport GSH into bile, the major driving force of bile-acid-independent bile flow. We have shown previously that the herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), a peroxisome-proliferator agent, significantly increases bile-acid-independent bile flow in mice.

View Article and Find Full Text PDF

Ciprofibrate, an hypolipidaemic peroxisome proliferator, induced differentiation of HL-60 cells. The effect was greatly potentiated by phorbol 12-myristate 13-acetate at a concentration where neither phorbol ester nor ciprofibrate alone had any effect on these cells. As occurs for HL-60 cell differentiation induced by high phorbol ester concentration, the ciprofibrate-induced phorbol ester-dependent differentiation of HL-60 cells proceeded through the monocytic/macrophage pathway and induced the phosphorylation of proteins with similar molecular weights suggesting that increased protein kinase C activity may be involved in the effect.

View Article and Find Full Text PDF

Polymorphisms of cytochrome P450 genes show pronounced interethnic variation and have not been previously studied in the South-Amerindian population, which probably has an Asian origin. Therefore, a similar distribution of allelic and haplotype frequencies of cytochrome P450 genes to Asian populations might be expected in South-Amerindians. We analysed the allelic frequencies and haplotype distribution for CYP2D6, CYP1A1 and CYP2E1 genes in the South-Amerindian population of Chile (Mapuche, n = 84) by Southern blot or polymerase chain reaction-restriction fragment length polymorphism.

View Article and Find Full Text PDF

Objectives: To compare the diagnostic accuracy of the most widely available tests for diagnosis of Helicobacter pylori infection after antibiotic treatment.

Methods: A total of 59 H. pylori-positive, duodenal ulcer patients (mean age, 40.

View Article and Find Full Text PDF

Background: In mice, fibrates induce mdr2 gene expression, and its encoded P-glycoprotein in the canalicular domain of hepatocytes, as well as increasing biliary phospholipid output. It is not known whether this effect is restricted to fibrates or is a common property of peroxisome proliferators.

Aims: To test the effect of structurally unrelated peroxisome proliferators on mdr2 gene expression and biliary phospholipid output, and to explore the molecular mechanism(s) of mdr2 gene induction.

View Article and Find Full Text PDF