Induction of immune interferon in mice treated with a bacterial immunopotentiator,OK-432

Summary When a bacterial immunopotentiator, OK-432, was injected to intact DDI mice, a viral inhibitor with the properties of immune interferon (IF) was induced in the circulation. The maximum titer of antiviral activity (10,240 units/ml) was observed 24 h after intraperitoneal (IP) injection of 50 KE OK-432/kg body weight. The possibility that the induction of immune IF may depend upon the action of thymus-derived (T) lymphocytes and macrophages was inferred from experiments with thymus-defective nude mice and DDI mice treated with either X-rays or immunosuppressive agents.     

Role of PPARα and HNF4α in Stress-Mediated Alterations in Lipid Homeostasis

Stress is a risk factor for several cardiovascular pathologies. PPARα holds a fundamental role in control of lipid homeostasis by directly regulating genes involved in fatty acid transport and oxidation. Importantly, PPARα agonists are effective in raising HDL-cholesterol and lowering triglycerides, properties that reduce the risk for cardiovascular diseases. This study investigated the role of stress and adrenergic receptor (AR)-related pathways in PPARα and HNF4α regulation and signaling in mice following repeated restraint stress or treatment with AR-antagonists administered prior to stress to block AR-linked pathways. Repeated restraint stress up-regulated Pparα and its target genes in the liver, including Acox, Acot1, Acot4, Cyp4a10, Cyp4a14 and Lipin2, an effect that was highly correlated with Hnf4α. In vitro studies using primary hepatocyte cultures treated with epinephrine or AR-agonists confirmed that hepatic AR/cAMP/PKA/CREB- and JNK-linked pathways are involved in PPARα and HNF4α regulation. Notably, restraint stress, independent of PPARα, suppressed plasma triglyceride levels. This stress-induced effect could be attributed in part to hormone sensitive lipase activation in the white adipose tissue, which was not prevented by the increased levels of perilipin. Overall, this study identifies a mechanistic basis for the modification of lipid homeostasis following stress and potentially indicates novel roles for PPARα and HNF4α in stress-induced lipid metabolism.     

Serum Metalloproteinases 2 and 9 as Predictors of Gait Status,Pressure Ulcer and Mortality after Hip Fracture

Introduction

The aim of this study is to evaluate the serum activity of metalloproteinases (MMPs) -2 and -9 as predictors of pressure ulcer (PU), gait status and mortality 6 months after hip fracture.

Methods

Eighty-seven patients over the age of 65 admitted to the orthopedic unit from January to December 2010 with hip fracture were prospectively evaluated. Upon admission, patient demographic information, including age, gender and concomitant diseases, was recorded. Blood samples were taken for analysis of MMP -2 and -9 activity by gel zymography and for biochemical examination within the first 72 hours of the patient’s admission, after clinical stabilization. The fracture pattern (neck, trochanteric or subtrochanteric), time from admission to surgery, surgery duration and length of hospital stay were also recorded.

Results

Two patients were excluded due to the presence of pathological fractures (related to cancer), and three patients were excluded due to the presence of PU before admission. Eighty-two patients, with a mean age of 80.4 ± 7.3 years, were included in the analysis. Among these patients, 75.6% were female, 59.8% had PU, and 13.4% died 6 months after hip fracture. All patients underwent hip fracture repair. In a univariate analysis, there were no differences in serum MMP activity between hip fracture patients with or without PU. In addition, the multiple logistic regression analysis models, which were adjusted by age, gender, length of hospital stay and C-reactive protein, showed that the pro-MMP-9 complexed with neutrophil gelatinase-associated lipocalin form (130 kDa) was associated with gait status recovery 6 months after hip fracture.

Conclusions

In conclusion, serum pro-MMP-9 is a predictor of gait status recovery 6 months after hip fracture.     

Absence of intervening sequences and point mutations in the V domain within 23S rRNA in Campylobacter lari isolates

Although the absence of intervening sequences (IVSs) within the 23S rRNA genes in Campylobacter lari isolates has been described, there are apparently no reports regarding correlations between the nucleotide sequences of 23S rRNA genes and erythromycin (Ery) susceptibility in C. lari isolates. Here, we determined the minimum inhibitory concentrations of 35 C. lari isolates [n?=?19 for urease-positive thermophilic Campylobacter (UPTC); n?=?16 urease-negative (UN) C. lari] obtained from Asia, Europe, and North America. We found that the 18 isolates were resistant to the Ery (defined as ≧8 μg/mL), and three isolates, UPTC A1, UPTC 92251, and UPTC 504, showed increased resistance (16 μg/mL). No correlations between the IVSs in the helix 45 region within the 23S rRNA gene sequences and Ery resistance were identified in the C. lari isolates examined. In addition, no point mutations occurred at any expected or putative position within the V domain in the isolates. In conclusion, antibiotic resistance against the macrolide erythromycin is mediated through an alternative pathway to that described above.     

A CD4 mimic as an HIV entry inhibitor: Pharmacokinetics

To date, several small molecules of CD4 mimics, which can suppress competitively the interaction between an HIV-1 envelope glycoprotein gp120 and a cellular surface protein CD4, have been reported as viral entry inhibitors. A lead compound 2 (YYA-021) with relatively high potency and low cytotoxicity has been identified previously by SAR studies. In the present study, the pharmacokinetics of the intravenous administration of compound 2 in rats and rhesus macaques is reported. The half-lives of compound 2 in blood in rats and rhesus macaques suggest that compound 2 shows wide tissue distribution and relatively high distribution volumes. A few hours after the injection, both plasma concentrations of compound 2 maintained micromolar levels, indicating it might have promise for intravenous administration when used combinatorially with anti-gp120 monoclonal antibodies.     

Structural transition of a 15 amino acid residue peptide induced by GM1

The ganglioside GM1-binding peptide, p3, with a sequence of VWRLLAPPFSNRLLP, displayed a clear structural alteration depending on the presence or absence of GM1 micelles. The three-dimensional structures of the p3 peptide in the free and GM1 bound states were analyzed using two-dimensional NMR spectroscopic experiments with distance-restrained simulated annealing calculations. The NMR experiments for the p3 peptide alone indicated that the peptide has two conformers derived from the exchange of cis and trans forms at Pro(7)-Pro(8). Further study with theoretical modeling revealed that the p3 peptide has a curb conformation without regular secondary structure. On the other hand, the NMR studies for the p3 peptide with the GM1 micelles elucidated a trans conformer and gave a structure stabilized by hydrophobic interactions of beta- and helical turns. Based on these structural investigations, tryptophan, a core residue of the hydrophobic cluster, might be an essential residue for the recognition of the GM1 saccharides. The dynamic transition of the p3 peptide may play an important role in the function of GM1 as a multiple receptor as in the traditional pathway of the infection by cholera toxin.     

8-Oxoguanosine and uracil repair of nuclear and mitochondrial DNA in red and white skeletal muscle of exercise-trained old rats.

Oxoguanine DNA glycosylase (OGG1) and uracil DNA glycosylase (UDG) are two of the most important repair enzymes that are involved in the base excision repair processes to eliminate oxidative damage from mammalian DNA, which accumulates with aging. Red and white skeletal muscle fibers have very different antioxidant enzyme activities and resistance to oxidative stress. In this paper, we demonstrate that the activity of OGG1 is significantly higher in the red type of skeletal muscle compared with white fibers from old rats. Exercise training resulted in increased OGG1 activity in the nuclei of red fibers and decreased activity in nuclei of white fibers and in the mitochondria of both red and white fibers. The activities of UDG were similar in both red and white muscle fibers. Exercise training appears to increase the activity of UDG in the nuclei and mitochondria. However, exercise training affects the activity of OGG1 in nuclei and mitochondria differently, suggesting different regulation of the enzymes. In contrast, UDG showed similar activities in nuclei and mitochondrial extracts of exercise-trained animals. These data provide evidence for differential regulation of UDG and OGG1 in maintaining fidelity of DNA in oxidatively stressed cells.