Effects of natural resistance-associated macrophage protein 1 and toll-like receptor 2 gene polymorphisms on post-weaning piglet survivability

Predicting resistance or susceptibility to infectious diseases on the basis of the genotypes of animals regarding disease or immune related genes could be important in animal production. We evaluated the potential influence of the genetic polymorphisms of four immune related genes, porcine beta defensin 4, interferon-induced GTP-binding protein Mx1, natural resistance-associated macrophage protein 1 (Nramp1), and Toll-like receptor 2 (TLR2) on post-weaning piglet survivability in farms. We selected a single SNP that satisfied the criteria of non-synonymous substitutions and the minor allele frequency >0.1 from each gene, and performed PCR–RFLP. Distributions of allele and genotype frequencies of the SNPs were, in general, significantly different among the five breeds (Berkshire, Yorkshire, Duroc, Landrace, and Korean native pigs. Initially, 371 randomly collected Yorkshire × Landrace F1 piglets consisting of post-weaning survival (n = 185) and non-survival groups (n = 186) were genotyped for the selected SNPs. For the Nramp1 and TLR2 SNPs, genotype frequencies were significantly different between the two groups (P < 0.05). To confirm the results, additional animals that were collected in a different time-period were genotyped for the Nramp1 (n = 390) and TLR2 (n = 240) SNPs. The results using the combined samples (n = 761) were consistent with the initial analysis (P < 0.01), suggesting that the genetic polymorphisms of Nramp1 and TLR2 affect post-weaning piglet survivability. The relative risks, i.e. odds ratios, between the beneficial and non-beneficial genotypes to piglet survivability were 4.88 and 29.65 for the Nramp1 and TLR2 SNPs, respectively.     

Effects of Hydrogen Peroxide on Wound Healing in Mice in Relation to Oxidative Damage

It has been established that low concentrations of hydrogen peroxide (H₂O₂) are produced in wounds and is required for optimal healing. Yet at the same time, there is evidence that excessive oxidative damage is correlated with poor-healing wounds. In this paper, we seek to determine whether topical application of H₂O₂ can modulate wound healing and if its effects are related to oxidative damage. Using a C57BL/6 mice excision wound model, H₂O₂ was found to enhance angiogenesis and wound closure at 10 mM but retarded wound closure at 166 mM. The delay in closure was also associated with decreased connective tissue formation, increased MMP-8 and persistent neutrophil infiltration. Wounding was found to increase oxidative lipid damage, as measured by F₂-isoprostanes, and nitrative protein damage, as measured by 3-nitrotyrosine. However H₂O₂ treatment did not significantly increase oxidative and nitrative damage even at concentrations that delay wound healing. Hence the detrimental effects of H₂O₂ may not involve oxidative damage to the target molecules studied.     

Longitudinal Liver Stiffness Assessment in Patients with Chronic Hepatitis C Undergoing Antiviral Therapy

Background/Aims

Liver stiffness (LS) measurement by means of transient elastography (TE) is accurate to predict fibrosis stage. The effect of antiviral treatment and virologic response on LS was assessed and compared with untreated patients with chronic hepatitis C (CHC).

Methods

TE was performed at baseline, and at weeks 24, 48, and 72 in 515 patients with CHC.

Results

323 treated (62.7%) and 192 untreated patients (37.3%) were assessed. LS experienced a significant decline in treated patients and remained stable in untreated patients at the end of study (P<0.0001). The decline was significant for patients with baseline LS ≥ 7.1 kPa (P<0.0001 and P 0.03, for LS ≥9.5 and ≥7.1 kPa vs lower values, respectively). Sustained virological responders and relapsers had a significant LS improvement whereas a trend was observed in nonresponders (mean percent change −16%, −10% and −2%, for SVR, RR and NR, respectively, P 0.03 for SVR vs NR). In multivariate analysis, high baseline LS (P<0.0001) and ALT levels, antiviral therapy and non-1 genotype were independent predictors of LS improvement.

Conclusions

LS decreases during and after antiviral treatment in patients with CHC. The decrease is significant in sustained responders and relapsers (particularly in those with high baseline LS) and suggests an improvement in liver damage.     

Azithromycin and Ciprofloxacin Resistance in Salmonella Bloodstream Infections in Cambodian Adults

Background

Salmonella enterica is a frequent cause of bloodstream infection (BSI) in Asia but few data are available from Cambodia. We describe Salmonella BSI isolates recovered from patients presenting at Sihanouk Hospital Centre of Hope, Phnom Penh, Cambodia (July 2007–December 2010).

Methodology

Blood was cultured as part of a microbiological prospective surveillance study. Identification of Salmonella isolates was performed by conventional methods and serotyping. Antibiotic susceptibilities were assessed using disk diffusion, MicroScan and E-test macromethod. Clonal relationships were assessed by Pulsed Field Gel Electrophoresis; PCR and sequencing for detection of mutations in Gyrase and Topoisomerase IV and presence of qnr genes.

Principal Findings

Seventy-two Salmonella isolates grew from 58 patients (mean age 34.2 years, range 8–71). Twenty isolates were identified as Salmonella Typhi, 2 as Salmonella Paratyphi A, 37 as Salmonella Choleraesuis and 13 as other non-typhoid Salmonella spp. Infection with human immunodeficiency virus (HIV) was present in 21 of 24 (87.5%) patients with S. Choleraesuis BSI. Five patients (8.7%) had at least one recurrent infection, all with S. Choleraesuis; five patients died. Overall, multi drug resistance (i.e., co-resistance to ampicillin, sulphamethoxazole-trimethoprim and chloramphenicol) was high (42/59 isolates, 71.2%). S. Typhi displayed high rates of decreased ciprofloxacin susceptibility (18/20 isolates, 90.0%), while azithromycin resistance was very common in S. Choleraesuis (17/24 isolates, 70.8%). Two S. Choleraesuis isolates were extended spectrum beta-lactamase producer.

Conclusions and Significance

Resistance rates in Salmonella spp. in Cambodia are alarming, in particular for azithromycin and ciprofloxacin. This warrants nationwide surveillance and revision of treatment guidelines.     

Transient association of MCM complex proteins with the nuclear matrix during initiation of mammalian DNA replication

The minichromosome maintenance complex (MCM2-7) is the putative DNA helicase in eukaryotes, and essential for DNA replication. By applying serial extractions to mammalian cells synchronized by release from quiescence, we reveal dynamic changes to the sub-nuclear compartmentalization of MCM2 as cells pass through late G1 and early S phase, identifying a brief window when MCM2 becomes transiently attached to the nuclear-matrix. The data distinguish 3 states that correspond to loose association with chromatin prior to DNA replication, transient highly stable binding to the nuclear-matrix coincident with initiation, and a post-initiation phase when MCM2 remains tightly associated with chromatin but not the nuclear-matrix. The data suggests that functional MCM complex loading takes place at the nuclear-matrix.     

A Quantitative,Comparative Study of Element Variations Found within the Range of Blood Cells from the Tropical Ascidian Phallusia philippinensis,using the Nuclear Microscope

The present study examines the concentrations of vanadium, bromine and sulphur contained within cryofixed/freeze-dried blood cells of the ascidian Phallusia philippinensis. Elemental profiles of seven cell types were obtained using the National University of Singapore nuclear microscope, in order to ascertain the cell types predominantly involved in accumulation. Morula cells were found to contain the following mean values (in ppm dry weight); 7878 vanadium, 34484 bromine and 61078 sulphur. Signet ring cells contained 5191 vanadium, 23945 bromine and 15281 sulphur. Compartment cells had 606 vanadium, 20700 bromine and 24309 sulphur. Other less abundant cell types such as lymphocytes, macrogranular amoebocytes, carotenoid pigment cells and granular amoebocytes were also analysed and found to contain (in ppm) 4384, 6652, 2366 and 10246 vanadium, 19652, 15630, 5964 and 11735 bromine and 13289, 15309, 3106 and 42968 sulphur, respectively. Sulphur occurred in high levels in all cell types, which could indicate its involvement in the vanadium concentration process, while bromine, incorporated into complexes, may be utilised for anti-fouling rather than as a deterrent to predators.     

Glycation improves the thermostability of trypsin and chymotrypsin

A novel glycation procedure, in vacuo glycation, was used to attach glucose covalently to the lysine residues of trypsin and chymotrypsin. Glycated trypsin and glycated chymotrypsin have greatly increased thermostability compared to the native enzymes. For example, glycated bovine trypsin, incubated at 50 degrees C and pH 8.0 for 3 h, retained more than 50% of its original activity whereas the native enzyme was inactivated under the same conditions. Similarly, after incubation at 50 degrees C and pH 8.0, glycated bovine chymotrypsin retained 45% of its original activity and the native enzyme was inactivated. Glycated porcine trypsin is exceptionally thermostable and could be used to digest native ribonuclease at 70 degrees C without the need for prior denaturation. The apparent increase in the thermal stability of the glycated proteins observed in activity measurements is also reflected by an increase in the T(m) values determined with differential scanning calorimetry (DSC) and circular dichroism (CD). The glycation does not alter the activity or specificity of these enzymes.     

8-aminoquinolines as anticoccidials - Part III.

Analogues of the antimalarial pentaquine, 1, in which the nature of the side-chain on the 8-amino position was varied, were prepared and evaluated for anticoccidial activity both in vitro and in vivo. Specifically, both the inter-nitrogen distance and the nature of the terminal amino group were investigated. Novel analogues of equal or improved efficacy in vitro and in vivo to pentaquine were discovered.     

Inducible cytochrome P450 activities in renal glomerular mesangial cells: biochemical basis for antagonistic interactions among nephrocarcinogenic polycyclic aromatic hydrocarbons

BACKGROUND: Benzo(a)pyrene (BaP), anthracene (ANTH) and chrysene (CHRY) are polynuclear aromatic hydrocarbons (PAHs) implicated in renal toxicity and carcinogenesis. These PAHs elicit cell type-specific effects that help predict toxicity outcomes in vitro and in vivo. While BaP and ANTH selectively injure glomerular mesangial cells, and CHRY targets cortico-tubular epithelial cells, binary or ternary mixtures of these hydrocarbons markedly reduce the overall cytotoxic potential of individual hydrocarbons. METHODS: To study the biochemical basis of these antagonistic interactions, renal glomerular mesangial cells were challenged with BaP alone (0.03 - 30 microM) or in the presence of ANTH (3 microM) or CHRY (3 microM) for 24 hr. Total RNA and protein will be harvested for Northern analysis and measurements of aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin-O-deethylase (EROD) activity, respectively, to evaluate cytochrome P450 mRNA and protein inducibility. Cellular hydrocarbon uptake and metabolic profiles of PAHs were analyzed by high performance liquid chromatography (HPLC). RESULTS: Combined hydrocarbon treatments did not influence the cellular uptake of individual hydrocarbons. ANTH or CHRY strongly repressed BaP-inducible cytochrome P450 mRNA and protein expression, and markedly inhibited oxidative BaP metabolism. CONCLUSION: These findings indicate that antagonistic interactions among nephrocarcinogenic PAHs involve altered expression of cytochrome P450s that modulate bioactivation profiles and nephrotoxic/ nephrocarcinogenic potential.     

Genetic diversity of Salmonella enterica serovar Paratyphi A from different geographical regions in Asia

AIMS: Subtyping of Salmonella Paratyphi A isolates from India, Pakistan, Indonesia and Malaysia was carried out by pulsed-field gel electrophoresis (PFGE) to assess the extent of genetic diversity of these isolates from different endemic countries. METHODS AND RESULTS: A total of 39 human isolates of Salmonella Paratyphi A from Pakistan, India, Indonesia and Malaysia were studied using PFGE analysis following digestion of chromosomal DNA with XbaI. Seven isolates from Pakistan were resistant to ampicillin, tetracycline and cotrimoxazole. It was noted that Salmonella Paratyphi A isolates obtained from outbreaks in India had limited genetic diversity and probably belonged to closely related clones. Significant genetic homogeneity was observed among antimicrobial-resistant isolates from Pakistan and antimicrobial-sensitive isolates from Pakistan and Indonesia, respectively. CONCLUSIONS: PFGE was a useful subtyping technique to differentiate Salmonella Paratyphi A from different endemic countries. However, it fails to differentiate the antimicrobial-resistant and -sensitive strains. SIGNIFICANCE AND IMPACT OF THE STUDY: The findings of the present study verify the usefulness of PFGE in characterizing and comparing strains of Salmonella Paratyphi A. Our study suggests that a limited number of clones are responsible for paratyphoid fever in these countries.