Characterization of a bifunctional enzyme with (p)ppGpp-hydrolase/synthase activity in Leptospira interrogans.

Alarmone Guanosine 5'-diphosphate (or 5'-triphosphate) 3'-diphosphate [(p)ppGpp] is the key component that globally regulates stringent control in bacteria. There are two homologous enzymes, RelA and SpoT in Escherichia coli, which are responsible for fluctuations in (p)ppGpp concentration inside the cell, whereas there exists only a single RelA/SpoT enzyme in Gram-positive bacteria. We have identified a bifunctional enzyme with (p)ppGpp-hydrolase/synthase activity in Leptospira interrogans.

Establishment of a leptospirosis model in guinea pigs using an epicutaneous inoculations route.

Background: Leptospires are presumed to enter their host via small abrasions or breaches of the skin. The intraperitoneal route, although commonly used in guinea pig and hamster models of leptospirosis, does not reflect conditions encountered during natural infection. The aim of this study is to develop a novel leptospirosis guinea pig model through epicutaneous route and to elucidate the pathogenesis of leptospirosis in experimental guinea pigs by comparing the data from other studies using different infection routes.

Decrease of plasma platelet-activating factor acetylhydrolase activity in lipopolysaccharide induced mongolian gerbil sepsis model.

Platelet-activating factor (PAF) plays an important role in the pathogenesis of sepsis, and the level of plasma PAF acetylhydrolase (pPAF-AH), which inactivates PAF, decreases in sepsis patients except for the sepsis caused by severe leptospirosis. Usually, increase of pPAF-AH activity was observed in lipopolysaccharide (LPS)-induced Syrian hamster and rat sepsis models, while contradictory effects were reported for mouse model in different studies. Here, we demonstrated the in vivo effects of LPS upon the change of pPAF-AH activity in C57BL/6 mice and Mongolian gerbils.

[Expression of epithelial Na+ channel in human nasal polyp].

Objective: To evaluate the expression of epithelial sodium channel in nasal polyps and normal nasal mucosa and to characterize the ENaC-mediated Na(+) absorption and the mechanism of the liquid transport in human upper airway epithelia.

Methods: The tissue from 12 patients with nasal polyps (NP) and the normal ethmoid cornu mucosa (ECM) from 5 patients were obtained through endoscopic surgery. The expression of ENaC was detected by Immunofluorescence and the concentration of ENaC alpha, beta, gamma-mRNA were detected by RT real-time PCR.

[Analysis of discrepancies between clinical and autopsy diagnoses in 188 cases].

Objective: To analyze the discrepancies between clinical and autopsy diagnoses in hospitals of different grades and with respect to duration of hospitalization.

Methods: A total of 188 autopsy cases collected from hospitals of different grades were retrospectively reviewed and the discrepancies between clinical and autopsy diagnoses were analyzed.

Results: The overall rate of misdiagnosis was 48.

Serum activity of platelet-activating factor acetylhydrolase is a potential clinical marker for leptospirosis pulmonary hemorrhage.

Pulmonary hemorrhage has been recognized as a major, often lethal, manifestation of severe leptospirosis albeit the pathogenesis remains unclear. The Leptospira interrogans virulent serogroup Icterohaemorrhagiae serovar Lai encodes a protein (LA2144), which exhibited the platelet-activating factor acetylhydrolase (PAF-AH) activity in vitro similar to that of human serum with respect to its substrate affinity and specificity and thus designated L-PAF-AH. On the other hand, the primary amino acid sequence of L-PAF-AH is homologous to the alpha1-subunit of the bovine brain PAF-AH isoform I.

Expression of TGF-beta1, TbetaRII and Smad4 in colorectal carcinoma.

Background: Many colorectal carcinomas are resistant to the growth inhibitory response of transforming growth factor-beta (TGF-beta) due to alterations of components along the TGF-beta signaling pathway. The aim of this study was to examine the expression of TGF-beta1, TbetaRII and Smad4 in human colorectal carcinoma and their relationships with cancer growth.

Methods: Immunohistochemistry and in situ hybridization were performed in 38 cases of colorectal carcinoma.

In silico and microarray-based genomic approaches to identifying potential vaccine candidates against Leptospira interrogans.

Background: Currently available vaccines against leptospirosis are of low efficacy, have an unacceptable side-effect profile, do not induce long-term protection, and provide no cross-protection against the different serovars of pathogenic leptospira. The current major focus in leptospirosis research is to discover conserved protective antigens that may elicit longer-term protection against a broad range of Leptospira. There is a need to screen vaccine candidate genes in the genome of Leptospira interrogans.

Disordered beta-catenin expression and E-cadherin/CDH1 promoter methylation in gastric carcinoma.

Aim: To investigate the distribution of beta-catenin in nuclei or membrane/cytoplasm of gastric carcinoma cells, the relationship between E-cadherin gene methylation and its expression, and the role of beta-catenin and E-cadherin as potential molecular markers in predicting tumor infiltration.

Methods: Twenty-nine cases of gastric carcinoma, classified as diffuse and intestinal variants, were selected for study. Nuclear and cytoplasmic proteins were purified and beta-catenin content was detected by ELISA.

[Technique of detection of hepatitis C core antigen used in safety blood transfusion].

This study was purposed to investigate the feasibility to screen donor with HCV infection by means of HCV-cAg ELISA. The first and repeat assays were performed for detection of serum anti-HCV in 8677 donor's serum specimens from January 2003 to December 2005. All serum anti-HCV specimens with positive anti-HCV from first and repeat assays were finally identified by using HCV-cAg ELISA and HCV RT-PCR methods.

Thrombocytopenia in the experimental leptospirosis of guinea pig is not related to disseminated intravascular coagulation.

Background: Thrombocytopenia is commonly observed in severe leptospirosis. However, previous studies on coagulation alterations during leptospirosis resulted in inconsistent conclusions. Some findings showed that the prominent levels of thrombocytopenia observed in severe leptospirosis did not reflect the occurrence of disseminated intravascular coagulation (DIC) syndrome, while the others reached the conclusion that the hemorrhages observed in leptospirosis were due to DIC.