Associations between glutathione peroxidase-1 Pro198Leu polymorphism, selenium status, and DNA damage levels in obese women after consumption of Brazil nuts

Objective

Alterations in selenium (Se) status may result in suboptimal amounts of selenoproteins, which have been associated with increased oxidative stress levels. The Pro198Leu polymorphism at the glutathione peroxidase-1 (GPx1) gene is supposed to be functional. The response of Se status, GPx activity, and levels of DNA damage to a Se supplementation trial between the genotypes related to that polymorphism was investigated.

Methods

A randomized trial was conducted with 37 morbidly obese women. Participants consumed one Brazil nut, which provided approximately 290 μg of Se a day, for 8 wk. Blood Se concentrations, erythrocyte GPx activity, and DNA damage levels were measured at baseline and at 8 wk. The results were compared by genotypes.

Results

The genotype frequencies were 0.487, 0.378, and 0.135 for Pro/Pro (the wild-type genotype), Pro/Leu, and Leu/Leu, respectively. At baseline, 100% of the subjects were Se deficient, and after the supplementation, there was an improvement in plasma Se (P < 0.001 for Pro/Pro and Pro/Leu, P < 0.05 for Leu/Leu), erythrocyte Se (P = 0.00 for Pro/Pro and Pro/Leu, P < 0.05 for Leu/Leu), and GPx activity (P = 0.00 for Pro/Pro, P < 0.00001 for Pro/Leu, P < 0.001 for Leu/Leu). In addition, the Pro/Pro group showed a decrease in DNA damage after Brazil nut consumption compared with baseline (P < 0.005), and those levels were higher in Leu/Leu subjects compared with those with the wild-type genotype (P < 0.05).

Conclusion

Consumption of one unit of Brazil nuts daily effectively increases Se status and increases GPx activity in obese women, regardless of GPx1 Pro198Leu polymorphism. However, the evaluated biomarkers showed distinct results in response to the supplementation when the polymorphism was considered.     

N-[2(S)-hydroxy-4-methylpentyl] tripeptide derivatives as inhibitors of renin

The following N-2(S)-hydroxy-4-methylpentyl derivatives of GlyValPheOMe and LeuValPheOMe were designed as analogues of the transition state of the renin—angiotensinogen reaction: N-[2(S)-hydroxy-4-methylpentyl] GlyValPheOMe 2 and N-[2(S-hydroxy-4-methylpentyl] LeuValPheOMe 3. Once synthesized they were tested for their abilities to inhibit hog kidney renin. The two compounds were found to have comparable activity to the known tetrapeptide inhibitors LeuGlyValPheOMe and LeuLeuValPheOMe. The type of kinetic behavior for each of the synthesized compounds was the same as that of the respective parent tetrapeptide; being competitive in the case of 2 and non-competitive in the case of 3.     

Association between GPx1 Pro198Leu polymorphism, GPx1 activity and plasma selenium concentration in humans

Background

Glutathione peroxidase 1 (GPx1) is an antioxidant selenoenzyme that protects the cells against reactive oxygen species. Its activity depends on the concentration of selenium (Se) which is present in the active centre of the enzyme. The genetic polymorphism of GPx1 encoding gene (GPx1) associated with the proline (Pro) to leucine (Leu) change at codon 198 is supposed to be functional. An in vitro study performed on human breast carcinoma cell line showed that GPx1Leu allele was associated with a lower responsiveness of the enzyme to Se added to the culture medium. Some authors observed a decrease in GPx1 activity associated with GPx1 Leu allele in humans; however, there were no findings on how GPx1 activity changes with Se concentration in individuals with different GPx1 genotypes.

Aim of the study

To assess whether GPx1 activity that depends on the Se status may be influenced by GPx1 polymorphism through studying this relationship in the blood of healthy individuals.

Methods

The association between the Se status, GPx1 activity and GPx1 genotype was assessed in 405 individuals of Polish origin. GPx1 activity in red blood cells was measured by the spectrophotometric method by Paglia and Valentine, using t-butylhydroperoxide as the substrate. Plasma Se concentration was measured using graphite furnace atomic absorption spectrometry. GPx1 Pro198Leu polymorphism was determined with the Molecular Beacon Real-Time PCR assay.

Results

In the subjects examined, the mean plasma Se concentration was 54.4 ± 14.2 mcg/L. The mean GPx1 activity was 15.1 ± 4.7 U/g Hb. No difference regarding both the parameters was found between individuals with different GPx1 genotype. However, the association between GPx1 activity and Se concentration, analyzed separately for each genotype group, was not the same. The correlation coefficients amounted to r = 0.44 (p < 0.001) for Pro/Pro, r = 0.35 (p < 0.001) for Pro/Leu and r = 0.25 (p = 0.45) for Leu/Leu group, which indicates that the correlation strength was as follows: Pro/Pro > Pro/Leu > Leu/Leu. Notably, statistically significant difference in this relationship (analyzed as difference between correlation coefficients for linear trends) was found between genotypes Pro/Pro and Leu/Leu (p = 0.034).

Conclusions

The findings of the present study provide evidence for the hypothesis based on in vitro studies which assumes that GPx1 Pro198Leu polymorphism has a functional significance for the human organism and that this functionality is associated with a different response of GPx1 activity to Se. They also point to the importance of the genetic background in the assessment of the Se status with the use of selenoprotein biomarkers such as GPx1 activity.     

Role of Leu72Met of GHRL and Gln223Arg of LEPR Variants on Food Intake,Subjective Appetite,and Hunger-Satiety Hormones

Appetite regulation has been recognized as a promising target for the prevention of obesity, which has become a worldwide health issue. Polymorphisms in the genes of hormones or receptors including Leu72Met for ghrelin and Gln223Arg for the leptin receptor could play a role in dietary intake, hunger, and satiety process. The aim of this study was to analyze subjective appetite assessments, dietary intake, and appetite hormones in relationship to these polymorphisms. Subjects (n = 132) with normal BMIs were enrolled. Dietary intake was analyzed with 3-day diet records. Subjective appetite was measured by visual analogue scales. Biochemical parameters were measured after 12 h of fasting and 120′ following ingestion of a test meal. Ghrelin and leptin levels were measured by ELISA assay (enzyme-linked immunosorbent assay) and insulin by chemiluminescence assay. The polymorphisms were determined by allelic discrimination using TaqMan^® probes. Fasting ghrelin levels differed significantly between men and women. The consumption of fruit and bread/starch with added sugar servings, as indicated by dietary records, and measured ghrelin levels were higher in carriers of Leu72Met/Met72Met compared to Leu72Leu carriers; total sugar intake was higher in Gln223Gln carriers than in Gln223Arg/Arg223Arg carriers. In conclusion, the Leu72Met and Gln223Arg polymorphism in ghrelin and LEPR may contribute to differential responses to a standardized meal as evidenced by higher postprandial levels of ghrelin and may also contribute to a higher dietary sugar intake.     

3H-leucine single-injection method for determining endogenous amino acid losses of broilers

ObjectiveA ³H-leucine (³H-Leu) single-injection method was proposed for determining the endogenous amino acid losses of broilers. This method was based on the hypothesis that the ratio of the specific radioactivity (SR) of endogenous Leu in excreta (SR_e) to that of free Leu in trichloroacetic acid–soluble plasma (SR_p) remains constant after a single subcutaneous injection of ³H-Leu into birds fed different diets.MethodsTwo experiments were designed to clarify this hypothesis. In experiment 1, 40 female broilers were randomly divided into four groups and were force-fed a nitrogen-free diet (NFD), NFD plus enzyme-hydrolyzed casein (EHC), 5% crude protein (CP) and SBM (soybean meal), or 20% CP-SBM. In experiment 2, 24 broilers were randomly divided into four groups and were fasted or force-fed the NFD, 20% CP-SBM, or 20% CP and cottonseed meal (CSM) diet. After the forced feeding, broilers were administered ³H-Leu by a single subcutaneous injection at a rate of 30 μCi/kg of body weight. Blood samples were taken at 5 min, 30 min, 4 h, 24 h, 36 h, and 48 h after the injection. The excreta were totally collected and pooled over the 48-h experiment.ResultsThe ratios of SR_e to SR_p remained the same for the birds force-fed the NFD, NFD + EHC, and 5% CP-SBM diets in experiment 1 and for the birds fasted and force-fed the NFD diet in experiment 2. The proportions of endogenous Leu to total Leu in excreta were 72.8%, 61.4%, and 57.5% for birds force-fed with the 20% CP-SBM diet in experiment 1 and 20% CP-SBM and 20% CP-CSM diets in experiment 2, respectively. Broilers fed the 5% CP-SBM and 20% CP-SBM diets excreted more (P < 0.05) endogenous Leu than those fed the NFD and NFD + EHC diets in experiment 1. Broilers fed the 20% CP-SBM diet excreted more (P < 0.05) endogenous Leu than those fed the NFD diet and fasted and the 20% CP-CSM diet was intermediate (P > 0.05) in experiment 2.ConclusionThe present study verified the hypothesis that the ratio of SR_e to SR_p remains constant after a single subcutaneous injection of ³H-Leu into broilers and proposes a new method to determine endogenous amino acid losses of broilers.     

NADH Dehydrogenase Subunit-2 237 Leu/Met Polymorphism Modulates the Effects of Coffee Consumption on the Risk of Hypertension in Middle-Aged Japanese Men

Background

Habitual coffee consumption has been reported to lower blood pressure in the Japanese population. The NADH dehydrogenase subunit-2 237 leucine/methionine (ND2-237 Leu/Met) polymorphism is associated with longevity and modifies the effects of alcohol consumption on blood pressure in the Japanese population. The objective of this study was to determine whether this polymorphism also modifies the effects of coffee consumption on blood pressure or the risk of hypertension in middle-aged Japanese men.

Methods

A total of 398 men (mean age ± standard deviation, 53.8 ± 7.8 years) were selected from among individuals visiting the hospital for regular medical check-ups. Hypertension was defined as a systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, or antihypertensive drug treatment. Polymerase chain reaction-restriction fragment length polymorphism using the restriction enzyme AluI was performed to determine ND2-237 Leu/Met genotype.

Results

In subjects with ND2-237Leu, coffee consumption was significantly and negatively associated with diastolic blood pressure (P = 0.007). The odds ratio (OR) for hypertension was significantly lower in subjects with ND2-237Leu who consumed 2 or 3 cups of coffee per day than in those who consumed less than 1 cup of coffee per day (OR, 0.517; 95% confidence interval [CI], 0.276 to 0.968; P = 0.039). After adjustment, the OR remained significant (OR = 0.399; 95% CI, 0.184 to 0.869; P = 0.020). Moreover, after adjustment, the OR was significantly lower in subjects with ND2-237Leu who consumed more than 4 cups of coffee per day than in those who consumed less than 1 cup of coffee per day (OR, 0.246; 95% CI, 0.062 to 0.975; P = 0.046). However, the association between ND2-237Met genotype and hypertension did not depend on coffee consumption.

Conclusions

The present results suggest that the ND2-237 Leu/Met polymorphism modulates the effects of coffee consumption on hypertension risk in middle-aged Japanese men.Key words: coffee consumption, hypertension, NADH dehydrogenase, polymorphism, personalized preventive medicine     

The Val34Leu genetic variation in the A Subunit of Coagulation Factor XIII in recurrent spontaneous abortion

The present study was carried out to assess the frequencies of factor XIII (FXIII) Val34Leu genetic variation in the patients with recurrent spontaneous abortion and healthy fertile women of Azeri Turkish origin. A total of 54 patients with recurrent spontaneous abortion and 46 healthy fertile women as controls were studied for the FXIII Val34Leu genetic variation by a RFLP-PCR method. Statistical analysis showed that patients (χ²?=?2.4, p value?=?0.292) and controls (χ²?=?1.035, p value?=?0.596) were in agreement with Hardy-Weinberg equilibrium. The Leu allele frequency was 0.18 and 0.13 in patients and controls, respectively. FXIII Leu34Leu (homozygous for 34Leu) genotype was not found in patients and controls. FXIII Val/Leu and Val/Val genotype frequencies were 19 (35.19%) and 31 (64.81%) in patients and 12 (26.09%) and 34 (73.91%) in controls, respectively. FXIII 34Leu allele and Val34Leu genotypes were more common in the case group containing individuals with unexplained RSA but the differences of FXIII Val34Leu (G/T genotype) (odds ratio?=?0.65 (0.25?<?OR?<?1.67) corresponding to 95% CI, χ²?=?0.96, p value?=?0.32) and FXIII 34Leu (T allele) (odds ratio?=?0.70 (0.30?<?OR?<?1.64) corresponding to 95% CI, χ² ₌ 0.78, p value?=?0.37) was not statistically significant. These results suggest that factor XIII Val34Leu genetic variation is not associated with recurrent spontaneous abortion.     

Post-Meal Responses of Elongation Factor 2 (eEF2) and Adenosine Monophosphate-Activated Protein Kinase (AMPK) to Leucine and Carbohydrate Supplements for Regulating Protein Synthesis Duration and Energy Homeostasis in Rat Skeletal Muscle

Previous research demonstrates that the anabolic response of muscle protein synthesis (MPS) to a meal is regulated at the level of translation initiation with signals derived from leucine (Leu) and insulin to activate mTORC1 signaling. Recent evidence suggests that the duration of the meal response is limited by energy status of the cell and inhibition of translation elongation factor 2 (eEF2). This study evaluates the potential to extend the anabolic meal response with post-meal supplements of Leu or carbohydrates. Adult (~256 g) male Sprague-Dawley rats were food deprived for 12 h, then either euthanized before a standard meal (time 0) or at 90 or 180 min post-meal. At 135 min post-meal, rats received one of five oral supplements: 270 mg leucine (Leu270), 80:40:40 mg leucine, isoleucine, and valine (Leu80), 2.63 g carbohydrates (CHO2.6), 1 g carbohydrates (CHO1.0), or water (Sham control). Following the standard meal, MPS increased at 90 min then declined to pre-meal baseline at 180 min. Rats administered Leu270, Leu80, CHO2.6, or CHO1.0 maintained elevated rates of MPS at 180 min, while Sham controls declined from peak values. Leu80 and CHO1.0 treatments maintained MPS, but with values intermediate between Sham controls and Leu270 and CHO2.6 supplements. Consistent with MPS findings, the supplements maintained elongation activity and cellular energy status by preventing increases in AMP/ATP and phosphorylation of adenosine monophosphate-activated protein kinase (AMPK), acetyl-CoA carboxylase ACC and eEF2. The impact of the supplements on MPS and cellular energy status was in proportion to the energy content within the individual treatments (i.e., Leu270 > Leu80; CHO2.6 > CHO1.0), but the Leu supplements produced a disproportionate anabolic stimulation of MPS, eEF2 and energy status with significantly lower energy content. In summary, the incongruity between MPS and translation initiation at 180 min reflects a block in translation elongation due to reduced cellular energy, and the extent to which Leu or carbohydrate supplements are able to enhance energy status and prolong the period of muscle anabolism are dose and time-dependent.     

Molecular characterization of a clinical Haemophilus parainfluenzae isolate with cefotaxime resistance and decreased susceptibility to fluoroquinolones

We report an H. parainfluenzae clinical isolate resistant to cefotaxime and with decreased susceptibility to ciprofloxacin recovered from a patient with cystic fibrosis. The isolate had elevated MICs of ampicillin (256 mg/L), amoxicillin-clavulanate (8 mg/L), cefuroxime (8 mg/L) and cefotaxime (4 mg/L), and showed a β-lactamase-producing amoxicillin-clavulanic acid-resistant (BLPACR) phenotype. A bla_TEM-1 plus five amino acid substitutions in the PBP3 were found: Ser385Thr, Val511Ala, Ile519Val, Asn526Lys and Asp551Leu. MIC of ciprofloxacin was 0.5 mg/L, and substitutions in gyrA (Ser84Tyr) and parC (Ser84Phe) genes were detected.     

Detection of rifampicin resistance of Mycobacterium tuberculosis using multiplex allele specific polymerase chain reaction (MAS-PCR) in Pakistan

Drug resistance in tuberculosis (TB) is a major public health challenge in developing countries such as Pakistan. Multiplex allele specific polymerase chain reaction (MAS-PCR) is a DNA amplification method that could contribute to rapid detection and control of drug resistant tuberculosis (DR-TB) in Pakistan. The purpose of this study was to test the utility of MAS-PCR to detect resistance in Pakistan. Drug susceptibility testing (DST) was used to identify rifampicin resistant and susceptible clinical isolates from TB cases in Pakistan. MAS-PCR was used to detect the most frequent mutations in the gene rpoB among 213 resistant and 37 susceptible isolates. Among 213 clinical isolates, MAS-PCR identified mutation D435Y (Asp435Tyr) in 24 (11.3%) cases, H445Y (His445Tyr) in 14 (6.6%), S450L (Ser450Leu) in 124 (58.2%) and S450W (Ser450Trp) in 18 (8.4%) cases. MAS-PCR did not detect known mutations in 33 (15.5%) cases. Among 12 cases, a novel mutation at codon 434 (Met434Ile) and a common variant at codon 435 (Asp435Tyr) was detected in rpoB gene which is indicative of double mutation. In 4 isolates, a novel mutation at codon 432 (Gln432Pro) was identified. In an additional 4 isolates, mutations Met434Val and His445Asn were identified. Moreover, a mutation in rpoB (Leu452Pro) was found in 5 isolates. DNA sequencing confirmed the absence of mutations in rpoB in the 8 remaining isolates. MAS-PCR had 88.3% sensitivity and 100% specificity using DST as the reference, which suggested that this method could be implemented as an initial marker for screening of multi-drug resistant tuberculosis (MDR-TB) in Pakistan.     

Effects of whey protein and leucine supplementation on insulin resistance in non-obese insulin-resistant model rats

ObjectiveWhey protein (WP) has been reported to reduce body weight gain and improve glucose metabolism in obese individuals. This study aims to assess and compare the effects of WP and its hydrolysate-leucine (Leu) supplementation in non-obese, insulin-resistant (IR) rat models, particularly the effects on insulin sensitivity, lipid profile, and antioxidant activity.MethodsWistar rats were fed a diet consisting of 38.5% fat for 12 wk and 51.3% fat for an additional 4 wk to establish non-obese IR rats. The IR rats were then switched to regular AIN-93 diet containing 0% WP, 5% WP, 15% WP or 1.6% Leu for 8 wk. The Leu content was the same in the 15% WP and 1.6% Leu groups based on high-performance liquid chromatography. The IR rats' body weight, fasting blood glucose, fasting insulin, and homeostasis model assessment-insulin resistance were measured before and after supplementation. An oral glucose tolerance test was performed after supplementation. Body composition, plasma concentrations of the lipids profile, and antioxidant index also were analyzed.ResultsNo significant difference was observed in body weight, energy intake, and fasting blood glucose in the non-obese IR rats at the end of the experiment. Compared with the 0% WP group, the fasting insulin and homeostasis model assessment-insulin resistance significantly decreased in the 15% WP and 1.6% Leu groups. Furthermore, the blood glucose area under the curve of the oral glucose tolerance test was significantly less in the 15% WP and 1.6% Leu groups. There were no differences in the lipids profile, except for the increase in the high-density lipoprotein cholesterol in the 15% WP and 1.6% Leu groups. For the antioxidant index, the 15% WP group had significantly increased plasma levels for total antioxidation capacity, superoxide dismutase, and glutathione, and a decreased malondialdehyde concentration. The 1.6% Leu group was shown to have the same effect as the 15% WP group, except for the glutathione.ConclusionOur findings demonstrate that the supplementation of WP and Leu may improve IR and antioxidant stress without resulting in changes in body weight and energy intake in non-obese IR rats.     

Resistance to Fluoroquinolone by a Combination of Efflux and Target Site Mutations in Enteroaggregative Escherichia coli Isolated in Korea

ObjectivesEnteroaggregative Escherichia coli (EAEC) was recently reported as a major diarrheagenic pathogen in infant and adult travelers, both in developing and developed countries. EAEC strains are known to be highly resistant to antibiotics including quinolones. Therefore in this study we have determined the various mechanisms of quinolone resistance in EAEC strains isolated in Korea.MethodsFor 26 EAEC strains highly resistant to fluoroquinolone, minimal inhibitory concentrations for fluoroquinolones were determined, mutations in the quinolone target genes were identified by PCR and sequencing, the presence of transferable quinolone resistance mechanism were identified by PCR, and the contribution of the efflux pump was determined by synergy tests using a proton pump inhibitor. The expression levels of efflux pump-related genes were identified by relative quantification using real-time PCR.ResultsApart from two, all tested isolates had common mutations on GyrA (Ser83Leu and Ser87Gly) and ParC (Ser80Gln). Isolates EACR24 and EACR39 had mutations that have not been reported previously: Ala81Pro in ParC and Arg157Gly in GyrA, respectively. Increased susceptibility of all the tested isolates to ciprofloxacin and norfloxacin in the presence of the pump inhibitor implies that efflux pumps contributed to the resistance against fluoroquinolones. Expression of the efflux pump-related genes, tolC, mdfA, and ydhE, were induced in isolates EACR 07, EACR 29, and EACR 33 in the presence of ciprofloxacin.ConclusionThese results indicate that quinolone resistance of EAEC strains mainly results from the combination of mutations in the target enzyme and an increased expression of efflux pump-related genes. The mutations Ala81Pro in ParC and Arg157Gly in GyrA have not been reported previously; the exact influence of these mutations should be investigated further.     

TIRAP (MAL) S180L polymorphism is a common protective factor against developing tuberculosis and systemic lupus erythematosus.

Background and aimThe involvement of Toll-like receptor (TLR)-mediated pathways in infectious and autoimmunity has been suggested. The MyD88 adaptor-like (Mal) protein, also known as the TIR domain-containing adaptor protein (TIRAP), is implicated in the TLR2- and TLR4-mediated MyD88-dependent signaling pathway. The aim of this study was to investigate the influence of the functional TIRAP (MAL) S180L polymorphism on tuberculosis (TB) and four autoimmune diseases namely: rheumatoid arthritis (RA), primary Sjögren's syndrome (pSS), systemic lupus erythematosus (SLE) and type 1 diabetes mellitus (T1D).MethodsThis was a case–control and family based association study in which 1325 individuals from a well-defined Colombian population were involved. TIRAP (MAL) S180L genotyping was done by using a polymerase chain reaction-restriction fragment length polymorphism technique and by direct sequencing.ResultsLeu180 allele was found to be a protective factor against developing TB (odd ratio (OR): 0.53, 95% confidence interval (CI): 0.29–0.97) and SLE (OR: 0.29, 95% CI: 0.14–0.61) while no significant influence on RA, pSS and T1D was observed.ConclusionThese results support the influence of TIRAP (MAL) S180L polymorphism on TB and indicate that TB and SLE might share a common immunogenetic pathway in the innate immune response.     

Peptidyl and azapeptidyl methylketones as substrate analog inhibitors of papain and cathepsin B

Peptidyl methylketones containing Phe, Tyr, Tyr(I), Tyr(I₂), Leu and Ile in P₂ were synthesized and tested as substrate analog reversible inhibitors of papain and bovine spleen cathepsin B. The most effective cathepsin B inhibitor contained Tyr(I₂) and displayed an inhibition constant of 4.7 μM at pH 6.8 and 25°C, while Leu or Ile gave practically inert analogs. Replacement of the amino acids in P₂ with the analogous α-azaamino acids, as well as the glycine in P₁ with α-azaglycine, led to complete loss of inhibiting activity. Introducing alkoxy substituents at the methyl adjacent to the ketone group generally resulted in more effective inhibitors, with inhibition constants in the micromolar range for both papain and cathepsin B.     

Association between TLR3 rs3775291 and resistance to HIV among highly exposed Caucasian intravenous drug users

BackgroundTLR3 recognizes dsRNA and triggers immune responses against RNA and DNA viruses. A polymorphism in TLR3, rs3775291 (Leu412Phe), has been associated with the increased susceptibility to enteroviral myocarditis, protection against tick-borne encephalitis virus and HIV-1 infection. We investigated Caucasian intravenous drug users (IDUs) and blood donors in order to evaluate the associations between TLR3 genotypes and susceptibility to HIV infection.Materials and methodsA total of 345 Caucasian IDUs were recruited, 50% of them were HIV positive, 89% HCV and 77% HBV positive. Based on their history of needle sharing, 20 of the HIV negative IDUs were classified as highly exposed HIV seronegatives (HESNs), 68 as non-HESNs and 85 as unexposed. The control group consisting of 497 blood donors tested negative for all three viruses. TLR3 rs3775291 were determined by using TaqMan Allelic Discrimination Assay.ResultsThe TLR3 rs3775291 T allele frequency was similar among the HIV negative and HIV positive IDUs and blood donors – 36%, 31% and 34%, respectively. The frequency of persons possessing at least one TLR3 rs3775291 T allele was significantly higher in HESNs compared with blood donors and HIV positive IDUs (80% vs. 55%; p = 0.037 and 80% vs. 53%; p = 0.031, respectively). In the univariate analysis, persons who possessed at least one T allele had reduced odds of being HIV seropositive (OR = 0.29, 95% CI = 0.09–0.90). This association remained significant (OR = 0.25, 95% CI = 0.07–0.87) after the adjustment for other co-variates (HCV, HBV serostatus and duration of intravenous drug use).ConclusionsThe TLR3 rs3775291 T allele has a protective effect against HIV infection among HESNs IDUs.     

Iodo and diiodotyrosine epoxysuccinyl derivatives as selective inhibitors of cathepsin B

Eight new analogs of -trans-epoxysuccinyl- -leucylamido(3-methyl)butane (E-64-c) containing Phe, Tyr, Tyr(1) or Tyr(I₂) in place of Leu, were synthesized and tested as inhibitors of papain, bovine spleen cathepsin B, calpain I and II from porcine red cells and porcine kidney, respectively. By use of kinetic methods, the new E-64 analogs proved to irreversibly inactivate both papain and cathepsin B via reversible enzyme-inhibitor intermediates EI. Second-order rate constants for inactivation were in the range 3500-55 100 M⁻¹s⁻¹ for papain and 650–105 000 M⁻¹s⁻¹ for cathepsin B. For the inactivation of calpain I and II they ranged between 250 and 2000 M⁻¹s⁻¹ and were similar to those of the known E-64-c. The effectiveness of the amino acid contained in the inhibitors tested increased in the order Tyr(I) ≈ Tyr(I₂) < Tyr < Phe < Leu for papain and Phe < Tyr < Tyr(I) < Leu < Tyr(I₂) for cathepsin B inactivation. Replacement of the with the -trans-epoxysuccinyl unit caused a 10–100-fold decrease in inhibitor potencies.     

Amino Acid Profile in Malnourished Patients with Liver Cirrhosis and Its Modification with Oral Nutritional Supplements: Implications on Minimal Hepatic Encephalopathy

Low plasma levels of branched chain amino acids (BCAA) in liver cirrhosis are associated with hepatic encephalopathy (HE). We aimed to identify a metabolic signature of minimal hepatic encephalopathy (MHE) in malnourished cirrhotic patients and evaluate its modification with oral nutritional supplements (ONS) enriched with ß-Hydroxy-ß-methylbutyrate (HMB), a derivative of the BCAA leucine. Post hoc analysis was conducted on a double-blind placebo-controlled trial of 43 individuals with cirrhosis and malnutrition, who were randomized to receive, for 12 weeks, oral supplementation twice a day with either 220 mL of Ensure^® Plus Advance (HMB group, n = 22) or with 220 mL of Ensure^® Plus High Protein (HP group, n = 21). MHE evaluation was by psychometric hepatic encephalopathy score (PHES). Compared to the HP group, an HMB-specific treatment effect led to a larger increase in Val, Leu, Phe, Trp and BCAA fasting plasma levels. Both treatments increased Fischer’s ratio and urea without an increase in Gln or ammonia fasting plasma levels. MHE was associated with a reduced total plasma amino acid concentration, a reduced BCAA and Fischer´s ratio, and an increased Gln/Glu ratio. HMB-enriched ONS increased Fischer´s ratio without varying Gln or ammonia plasma levels in liver cirrhosis and malnutrition, a protective amino acid profile that can help prevent MHE.     

The Val34Leu genetic variation in the A subunit of coagulation factor XIII in recurrent spontaneous abortion

The present study was carried out to assess the frequencies of factor XIII (FXIII) Val34Leu genetic variation in the patients with recurrent spontaneous abortion and healthy fertile women of Azeri Turkish origin. A total of 54 patients with recurrent spontaneous abortion and 46 healthy fertile women as controls were studied for the FXIII Val34Leu genetic variation by a RFLP-PCR method. Statistical analysis showed that patients (χ2?=?2.4, p value?=?0.292) and controls (χ2?=?1.035, p value?=?0.596) were in agreement with Hardy-Weinberg equilibrium. The Leu allele frequency was 0.18 and 0.13 in patients and controls, respectively. FXIII Leu34Leu (homozygous for 34Leu) genotype was not found in patients and controls. FXIII Val/Leu and Val/Val genotype frequencies were 19 (35.19%) and 31 (64.81%) in patients and 12 (26.09%) and 34 (73.91%) in controls, respectively. FXIII 34Leu allele and Val34Leu genotypes were more common in the case group containing individuals with unexplained RSA but the differences of FXIII Val34Leu (G/T genotype) (odds ratio?=?0.65 (0.25?相似文献   

Rodentizidresistenz und Konsequenzen

Resistance to anticoagulant rodenticides, such as warfarin was first described in 1958. Polymorphisms in the vitamin K epoxide reductase complex subunit 1 (VKORC1) gene and respective substitutions of amino acids in the VKOR enzyme are the major cause for rodenticide resistance. Resistant Norway rats in Germany are characterized by the Tyr139Cys genotype, which is spread throughout the northwest of the country. Resistant house mice with the VKOR variants Tyr139Cys, Leu128Ser and Arg12Trp/Ala26Ser/Ala48Thr/Arg61Leu (spretus type) are distributed over a number of locations in Germany. Resistance can reduce management attempts with consequences for stored product protection, hygiene and animal health. Anticoagulants of the first generation (warfarin, chlorophacinone, coumatetralyl) as well as bromadiolone and difenacoum are not an option for the control of resistant Norway rats. The same applies for house mice whereby the tolerance to compounds can be different between local incidences. Due to the higher toxicity and tendency to persist, the most potent anticoagulant rodenticides brodifacoum, flocoumafen and difethialone should be applied but only where resistance is known. In other cases less toxic anticoagulants should be preferred for rodent management in order to mitigate environmental risks. Resistance effects of further VKOR polymorphisms and their combinations, the spread of resistant rats and conditions supporting and reducing resistance should be investigated in order to improve resistance management strategies.     

Protein Redistribution From Skeletal Muscle to Splanchnic Tissue on Fasting and Refeeding in Young and Older Healthy Individuals

BackgroundDuring aging, a shift of protein metabolism from muscle to splanchnic tissue contributes to increased muscle protein loss after a period of metabolic stress (eg, fasting).ObjectiveTo study the adaptation of protein metabolism in the whole body and tissue (ie, skeletal muscle and splanchnic area) to metabolic stress, such as short-term fasting and refeeding, in aged people.Design and participantsWe studied splanchnic and muscle protein metabolism after 38 hours of fasting and refeeding in 7 young (5 men/2 women, 24.4 ± 2.0 years) and 8 elderly individuals (6 men/2 women, 70.6 ± 3.1 years).MeasurementsWe used intravenous (IV) L-[¹³C₆]phenylalanine, IV L-[²H₃]leucine, and oral L-[¹³C₁]leucine to obtain (1) whole-body protein kinetics, (2) muscle and albumin fractional synthesis rate (FSR, %/d; ¹³C₆-Phe, and ¹³C₁-Leu), and (3) splanchnic extraction during fasting and refeeding (%, ²H₃- and ¹³C₁-Leu).ResultsWhole-body protein breakdown was activated during fasting in young and older individuals (P < .01 vs fasted state). Muscle FSR remained unchanged in both groups and not stimulated by refeeding in either group with either IV ¹³C Phe or oral ¹³C Leu, probably because of high plasma levels of essential amino acids (EAAs) and branched-chain amino acids (BCAAs). Splanchnic extraction of leucine was 42% higher in the elderly individuals (P = .03 vs young) and was associated with an increased albumin synthesis rate in elderly individuals in the fed state (P < .05 vs young).ConclusionSplanchnic protein metabolism is modified by age, but this metabolic change is not associated with a lower synthesis rate of muscle protein, provided high plasma levels of essential EAAs are maintained. Our data also suggest that splanchnic protein synthesis is a metabolic priority during recovery after metabolic stress in healthy elderly persons and that it might be even more affected in polymedicated older individuals having chronic diseases.