Ancylostoma ceylanicum infections in humans in Vietnam

Ancylostoma ceylanicum is recognized as the only zoonotic hookworm species that is able to mature into adult stage in the human intestine. While human infections caused by this hookworm species have been reported from neighboring countries and this hookworm is prevalent in dogs in Vietnam, human infection has never been reported in Vietnam. The present study, therefore, aimed to identify human infections with A. ceylanicum in Vietnam. A total of 526 fecal samples from the residents in Long An Province were collected and the presence of hookworm eggs was detected by the Kato-Katz method. The results indicated that the overall prevalence of human hookworm infection was 85/526 (16.2%). After filter paper culture, 3rd stage larvae were successfully obtained from 48 egg-positive samples. The larvae were identified for their species using semi-nested PCR-RLFP on the cox1 gene. As a result, two hookworm species were confirmed; single species infections with Necator americanus or A. ceylanicum, and mixed infections with both species were found in 47.9%, 31.3%, and 20.8% of the samples, respectively.

The effects of different types of statins on proliferation and migration of HGF-induced Human Umbilical Vein Endothelial Cells (HUVECs)

BACKGROUND AND AIM

Statins are HMG-CoA reductase inhibitors within the framework of cholesterol biosynthesis and used to lower the low-density lipoprotein (LDL). There are other aspects of statins can deploy a protective effect, even without the LDL's lowering. The aim of this study is to investigate the effects of different type of statins on proliferative and migrative behaviors of Hepatocyte Growth Factor (HGF) induced human umbilical vein endothelial cells (HUVECs).

MATERIALS AND METHODS

Human umbilical vein endothelial cells were isolated and cultured. Groups were designed in order to observe the effects of every individual substance. HUVECs were stimulated with HGF, statins and farnesylpyrophosphat ammonium salt (FPP) or geranylgeranyl-pyrophosphate (GGPP), respectively. Cell proliferations were counted 48 hours after initial stimuli and distances between migration fronts were used in migration analyses.

RESULTS

All types of statins showed significant anti-migrative and anti-proliferative characters. Simvastatin and fluvastatin but not cerivastatin, were able to inhibit the HGF-depending migration and showed a significant effect on the inhibition of the isoprenylation (GGPP). Only simvastatin influenced the HGF-depending migration via inhibiting the isoprenylation process through GGPP. Cerivastatin significantly decreased the proliferation and Fluvastatin significantly enhanced the migration behaviors of HUVECs when they were co-incubated with methyl-8-cyclodextrin (MCD).

CONCLUSIONS

Statins countermand the proproliferative and as well as the promigrative effect of HGF on HUVECs. The mechanisms which provoke this effect are dependent on the type of statin. Direct interactions of statins with lipid rafts play a significant role in the endothelial cell mechanisms.

A domain in TNF receptors that mediates ligand-independent receptor assembly and signaling

A conserved domain in the extracellular region of the 60- and 80-kilodalton tumor necrosis factor receptors (TNFRs) was identified that mediates specific ligand-independent assembly of receptor trimers. This pre-ligand-binding assembly domain (PLAD) is physically distinct from the domain that forms the major contacts with ligand, but is necessary and sufficient for the assembly of TNFR complexes that bind TNF-alpha and mediate signaling. Other members of the TNFR superfamily, including TRAIL receptor 1 and CD40, show similar homotypic association. Thus, TNFRs and related receptors appear to function as preformed complexes rather than as individual receptor subunits that oligomerize after ligand binding.

The sensitivity and specificity of two methods for detecting Fasciola infections in cattle

Counts of Fasciola spp. eggs in faeces and measurements of antibody concentration to the excretory/secretory antigens of Fasciola spp. by ELISA were related to the numbers of flukes in the livers of 92 cattle killed in the abattoirs of Hanoi City, Vietnam. In this population, about 22% of the cattle had no flukes, another 22% had between 1 and 10 flukes, 44% between 11 and 100 flukes and 12% had more than 100 flukes in their livers. Of the 14 animals less than 2 years of age, only three were infected. At 2 years of age the mean number of flukes per liver was 10 whereas at 3 years and older, the mean varied between 60 and 80 flukes. Prevalence of infection was 78.3%. No eggs of Fasciola spp. were detected in the faeces of one third of infected cattle and 60% of the counts were less than 100 eggs per gram. The sensitivity of the egg counting method was 66.7% and specificity 100%, overall accuracy was 73.9%. Corresponding values for the ELISA method were 86.1, 70 and 82.6%, respectively. The positive and negative predictive values for the egg counting method were 100 and 45.5% and for the ELISA method were 91.2 and 58.3%, respectively.