Systemic cytokine response in murine anthrax

Systemic pro-inflammatory cytokine release has been previously implicated as a major death-causing factor in anthrax, however, direct data have been absent. We determined the levels of IL-1 beta, IL-6 and TNF-alpha in serum of mice challenged with virulent (Ames) or attenuated (Sterne) strains of Bacillus anthracis. More than 10-fold increase in the IL-1beta levels was detected in Ames-challenged Balb/c mice, in contrast to more susceptible C57BL/6 mice, which showed no IL-1beta response. Balb/c mice have also responded with higher levels of IL-6. The A/J mice demonstrated IL-1beta and IL-6 systemic response to either Ames or Sterne strain of B. anthracis, whereas no increase in TNF-alpha was detected in any murine strain. We used RT-PCR for gene expression analyses in the liver which often is a major source of cytokines and one of the main targets in infectious diseases. A/J mice challenged with B. anthracis (Sterne) showed increased gene expression for Fas, FasL, Bax, IL-1 beta, TNF-alpha, TGF-beta, MIP-1alpha, KC and RANTES. These data favour the hypothesis that apoptotic cell death during anthrax infection causes chemokine-induced transmigration of inflammatory cells to vitally important organs such as liver. Administration of caspase inhibitors z-VAD-fmk and ac-YVAD-cmk improved survival in Sterne-challenged mice indicating a pathogenic role of apoptosis in anthrax.     

The effects of lycopene on hepatic ischemia/reperfusion injury in rats

There is a very little information about the protective effect of lycopene (LYC) against hepatic ischemia–reperfusion injury. The present study was designed to examine the possible protective effect of the strong antioxidant and anti-inflammatory agent, LYC, on hepatic ischemia/reperfusion injury. For this purpose, rats were subjected to 45 min of hepatic ischemia followed by 60 min of reperfusion period. LYC at the doses of 2.5 and 5 mg/kg body weight (bw) were injected intraperitoneally, 60 min prior to ischemia. Upon sacrification, hepatic tissue samples were used for the measurement of catalase (CAT) activity and malondialdehyde (MDA) levels. Also, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) were assayed in serum samples. As a result of the use of LYC at the doses of 2.5 and 5 mg/kg bw; while improvements of the ALT, AST, LDH and MDA values were partial and dose-dependent, the improvement of CAT activity was total and dose-independent (p < 0.05). Our findings suggest that LYC has a protective effect against ischemia/reperfusion injury on the liver.     

AIDA-1 Moves out of the Postsynaptic Density Core under Excitatory Conditions

AIDA-1 is highly enriched in postsynaptic density (PSD) fractions and is considered a major component of the PSD complex. In the present study, immunogold electron microscopy was applied to determine localization as well as the activity-induced redistribution of AIDA-1 at the PSD using two antibodies that recognize two different epitopes. In cultured rat hippocampal neurons under basal conditions, immunogold label for AIDA-1 is mostly located within the dense core of the PSD, with a median distance of ~30 nm from the postsynaptic membrane. Under excitatory conditions, such as depolarization with high K⁺ (90 mM, 2 min) or application of NMDA (50 μM, 2 min), AIDA-1 label density at the PSD core is reduced to 40% of controls and the median distance of label from the postsynaptic membrane increases to ~55 nm. The effect of excitatory conditions on the postsynaptic distribution of AIDA-1 is reversed within 30 minutes after returning to control conditions. The reversible removal of AIDA-1 from the PSD core under excitatory conditions is similar to the redistribution of another abundant PSD protein, SynGAP. Both SynGAP-alpha1 and AIDA-1 are known to bind PSD-95. Activity-induced transient translocation of these abundant proteins from the PSD core could promote structural flexibility, vacate sites on PSD-95 for the insertion of other components and thus may create a window for synaptic modification.     

Molecular epidemiology of methicillin-resistant Staphylococcus aureus isolates from clinical specimens of patients with nosocomial infection: are there unnoticed silent outbreaks?

Bacteriological and epidemiological studies were carried out on 90 isolates of methicillin-resistant Staphylococcus aureus (MRSA) at Turgut Ozal Medical Center of In?nü University, (Malatya/Turkey). MRSA isolates were obtained from patients with nosocomial infections. Staphylococcus aureus clinical isolates were collected between May 2004-May 2005. Isolates were tested for resistance to methicillin. Antimicrobial susceptibility testing and slime production evaluation was performed. Genotype studies were carried out by arbitrarily primed polymerase chain reaction (AP-PCR) and consequent cluster analysis. All of the isolates were mecA-positive in a PCR-based assay; all exhibited resistance to oxacillin, by agar dilution (MICs > or = 4 mg/L) and disc diffusion methods, and multiple antibiotics. Most MRSA isolates were collected in intensive care units. Of 90 samples, 53 were found to be unrelated to the others while the remaining 37 strains were either identical or closely related. Dendrogram analysis identified nine major clusters. These data support the opinion that MRSA are significant nosocomial pathogens in intensive care units and that resistant clones may be transmitted between patients. Molecular epidemiological tools are helpful for understanding transmission patterns and sources of infection, and are useful for measuring outcomes of intervention strategies implemented to reduce nosocomial MRSA.     

Phosphoproteomics identified Endofin, DCBLD2, and KIAA0582 as novel tyrosine phosphorylation targets of EGF signaling and Iressa in human cancer cells

With the completion of the human genome project, analysis of enriched phosphotyrosyl proteins from epidermal growth factor (EGF)-induced phosphotyrosine proteome permits the identification of novel downstream substrates of the EGF receptor (EGFR). Using cICAT-based LC-MS/MS method, we identified and relatively quantified the tyrosine phosphorylation levels of 21 proteins between control and EGF-treated A431 human cervical cancer cells. Of these, Endofin, DCBLD2, and KIAA0582 were validated to be novel tyrosine-phosphorylation targets of EGF signaling and Iressa, a highly selective inhibitor of EGFR. In addition, EGFR activity was shown to be necessary for EGF-induced localization of Endofin, an FYVE domain-containing protein regulated by phosphoinositol lipid and engaged in endosome-mediated receptor modulation. Although several groups have conducted phosphoproteomics of EGF signaling in recent years, our study is the first to identify and validate Endofin, DCBLD2, and KIAA0582 as part of a complex EGF phosphotyrosine signaling network. These novel data will provide new insights into the complex EGF signaling and may have implications on target-directed cancer therapeutics.     

Cost-Effectiveness and Cost Thresholds of Generic and Brand Drugs in a National Chronic Hepatitis B Treatment Program in China

Chronic liver disease and liver cancer associated with chronic hepatitis B (CHB) are leading causes of death among adults in China. Although newborn hepatitis B immunization has successfully reduced the prevalence of CHB in children, about 100 million Chinese adults remain chronically infected. If left unmanaged, 15–25% will die from liver cancer or liver cirrhosis. Antiviral treatment is not necessary for all patients with CHB, but when it is indicated, good response to treatment would prevent disease progression and reduce disease mortality and morbidity, and costly complications. The aim of this study is to analyze the cost-effectiveness of generic and brand antiviral drugs for CHB treatment in China, and assessing various thresholds at which a highly potent, low resistance antiviral drug would be cost-saving and/or cost-effective to introduce in a national treatment program. We developed a Markov simulation model of disease progression using effectiveness and cost data from the medical literature. We measured life-time costs, quality adjusted life years (QALYs), incremental cost-effectiveness ratios (ICERs), and clinical outcomes. The no treatment strategy incurred the highest health care costs ($12,932-$25,293) per patient, and the worst health outcomes, compared to the antiviral treatment strategies. Monotherapy with either entecavir or tenofovir yielded the most QALYs (14.10–19.02) for both HBeAg-positive and negative patients, with or without cirrhosis. Threshold analysis showed entercavir or tenofovir treatment would be cost saving if the drug price is $32–75 (195–460 RMB) per month, highly cost-effective at $62–110 (379–670 RMB) per month and cost-effective at $63–120 (384–734 RMB) per month. This study can support policy decisions regarding the implementation of a national health program for chronic hepatitis B treatment in China at the population level.     

Speedy/RINGO protein interacts with ERK/MAPK and PI3K/AKT pathways in SH-SY5Y neuroblastoma cells

Molecular and Cellular Biochemistry - Pro-inflammatory cytokines prevent bone regeneration in vivo and activation of nuclear factor-κB (NF-κB) signaling has been proposed to lead to...     

P53 related apoptosis in kidneys in CO2 pneumoperitoneum rat model: an immunohistochemical study

Laparoscopic surgery techniques have been increasingly preferred to classic laparotomy by surgeons since 1987. However, this method may have some side effects on different intraabdominal organs including kidneys. The aim of this study is to evaluate the effects of different pressures of CO₂ on p53 related apoptosis in kidneys. Totally 24 male rats were divided into four equal groups. CO₂ is insufflated into rats’ intraabdominal cavity in two different pressures of 10 and 20 mmHg during 1 h. However, in sham group, only cannula was inserted, but no gas was insufflated. After 1 h, 30 min reperfusion was applied. At last, the kidneys were excised and p53 expression and apoptosis were evaluated immunohistochemically. All the data revealed that the number of apoptotic cell in kidney’ tubular cells significantly increases in proportion to CO₂ pressure level. On the other hand, p53 expression was detected only in the highest pressure. Because the low CO₂ pressured group’ rats had no p53 expression in kidneys, we suggest that this method can be safely used for abdominal surgery. At the same time, increasing in the number of apoptotic cells parallel to pressure also suggest that CO₂ pressure level and application time are very important parameters during CO₂ pneumoperitoneum.     

Molecular mechanisms underlying adhesion and migration of hematopoietic stem cells

Hematopoietic stem cell transplantation is the most powerful treatment modality for a large number of hematopoietic malignancies, including leukemia. Successful hematopoietic recovery after transplantation depends on homing of hematopoietic stem cells to the bone marrow and subsequent lodging of those cells in specific niches in the bone marrow. Migration of hematopoietic stem cells to the bone marrow is a highly regulated process that requires correct regulation of the expression and activity of various molecules including chemoattractants, selectins and integrins. This review will discuss recent studies that have extended our understanding of the molecular mechanisms underlying adhesion, migration and bone marrow homing of hematopoietic stem cells.