Specific serum IgG, but not IgA, antibody against purified Opisthorchis viverrini antigen associated with hepatobiliary disease and cholangiocarcinoma

Opisthorchiasis caused by Opisthorchis viverrini infection induces hepatobiliary disease (HBD)-associated cholangiocarcinoma (CCA) via a chronic inflammatory immune response. Here, we evaluated specific IgG and IgA antibodies against different fractions of O. viverrini antigen in residents from an endemic community in Northeast Thailand with varying hepatobiliary abnormalities. Crude somatic O. viverrini antigen was purified into three fractions (viz., P1, P2 and P3) by gel infiltration chromatography and these served as antigens for detection of fluke-specific IgG and IgA antibodies by enzyme-linked immunosorbent assay (ELISA). The results revealed fluke-specific IgG and IgA antibody levels—against these antigens from subjects with O. viverrini-positive HBD—higher than in subjects with O. viverrini-negative HBD. Interestingly, the rank of fluke-specific IgG (and not IgA) antibody levels against crude extract and P1 antigens was CCA > severe HBD > mild HBD > healthy individuals. Purified antigens reduced cross-reactivity with other parasites compared to the crude antigen. Multiple linear regression analysis showed that HBD status was significantly associated with the liver fluke-specific IgG antibody against purified antigens. These results suggest that purified O. viverrini-antigen improves serodiagnosis for the evaluation of opisthorchiasis-associated HBD, and may be useful in the screening of opisthorchiasis in subjects at risk of developing CCA.     

Water-soluble polysaccharides with pharmaceutical importance from Durian rinds (Durio zibethinus Murr.): isolation, fractionation, characterisation and bioactivity

Crude, pharmaceutically useful water-soluble polysaccharides have been isolated from durian rinds (Durio zibethinus) by hot water extraction followed by ethanol precipitation. The polysaccharides were fractionated by anion exchange chromatography and size exclusion chromatography. Characterisation of the sub-fractions by methanolysis, methylation analysis and NMR spectroscopy revealed that the principal components were pectic polysaccharides with starch as a contaminant. Physical features namely molecular weight (M_w) and intrinsic viscosity of the main fractions were investigated by size exclusion chromatography coupled to multi angle laser light scattering (SEC/MALLS) and capillary viscometer, respectively. The main fractions were subjected to the complement-fixation assay and the relationship of the chemical features of the polysaccharide fractions with their activity was also considered.     

A Novel Anti-cancer Peptide Extracted from Gynura pseudochina Rhizome: Cytotoxicity Dependent on Disulfide Bond Formation

International Journal of Peptide Research and Therapeutics - As current anticancer drugs have limitations, researchers have sought novel anti-cancer agents with high specificity and fewer side...     

Antimicrobial resistance markers as a monitoring index of gonorrhoea in Thailand

Multiplex PCR was applied to explore the antimicrobial-resistance profiles of 145 gonococci isolated from Bangrak Hospital, Thailand in 2007. All isolates were clearly identified for the plasmid-mediated resistant types of penicillin (Asia, Africa and Toronto) and tetracycline (American and Dutch). This method can also predict the decreased susceptibility to ciprofloxacin by detection of Ser-91 mutation. Prevalence rates of penicillinase-producing Neisseria gonorrhoeae (PPNG) and high-level tetracycline-resistance N. gonorrhoeae (TRNG) were shown to be high as 82.1% and 84.1%, respectively. Most PPNG carried the Africa-type (78.2%) while the American-type (61.8%) was harboured in most TRNG. Mono- and triple-resistance patterns were presented in 2.6% and 79.5% of male, 20.7% and 62.1% of men who have sex with men (MSM), 0% and 75.0% of female, and 10% and 70% of female sex workers (FSW). Additionally, the rate of the Dutch type was high in patients among the age of 35-44 years (57.1%) and female patients (43.8%). The changing types of plasmids have been noticed during the time period of study. The multi-resistance patterns of the gonococcal isolates can be used as an epidemiological index of gonorrhoea and human sexual behaviours. This information will support the management of individual patients as well as the public health surveillance.     

Hemoglobin Constant Spring: hemoglobin synthesis in heterozygous and homozygous states.

Thirteen adult and one newborn heterozygotes, and three homozygotes for hemoglobin Constant Spring were examined for globin chain synthesis. Reticulocytes from venous blood were incorporated with [³H]-leucine in an incubation mixture for 3 hours. Globin prepared from the radioactive, washed red cells was fractionated by CM-cellulose chromatography in 8 M urea and the total radioactivity of each globin chain was determined. The mean of $\text{α}\text{β}$ ratio in the heterozygotes was 1.34 ± SD 0.08, which is significantly different from that of 1.07 ± SD 0.03 in eleven normal controls. The $\text{α}\text{β+γ}$ ratio in the heterozygous neonate was also 1.39. The $\text{α}\text{β}$ ratios in the three homozygotes were around 1.6. The α-Constant Spring chain appears to be over produced, but it may be unstable or labile, not fully available for conjugation with the non alpha chains.     

Studies on the immunomodulatory effect of polysaccharide gel extracted from Durio zibethinus in Penaeus monodon shrimp against Vibrio harveyi and WSSV

Oral administration of polysaccharide gel (PG) in shrimp diets revealed immunostimulating potential and disease resistance in Penaeus monodon (black tiger shrimp). PG from the fruit-rind of Durio zibethinus has been characterized to be a pectic polysaccharide with immunomodulating and antibacterial activities. PG inhibited growth of the shrimp bacterial pathogen, Vibrio harveyi 1526, by agar diffusion and broth microdilution tests. Clear inhibition zones on agar plates were observed at the lowest PG concentration of 3.1 mg/ml, where minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values for PG were 6.3 and 12.5 mg/ml, respectively. Each group of juvenile shrimps, initial mean body weight 0.29 ± 0.04 g, was housed in a closed-recirculating treated water system and was fed with PG-supplemented diets containing 1, 2 and 3% PG or shrimp basal diet in the control group for 8 and 12 weeks. PG-supplemented diets did not contribute to the overall growth of black tiger shrimp. The immune response was evaluated by analysis of prophenoloxidase activity and total hemocyte count in the shrimp fed PG-supplemented diets for 12 weeks. Prophenoloxidase activity in shrimp fed the 1, 2 and 3% PG-supplemented diet and total hemocyte count in shrimp fed the 1 and 2% PG-supplemented diet were higher (P < 0.05) than those of the control group. The percent survival was higher in groups fed the 1–3% PG-supplemented diets in challenge tests with either white spot syndrome virus (WSSV) or the bacterium V. harveyi 1526 than that of the control group. Relative percent survival (RPS) values in groups fed the 2% PG-supplemented diet showed the highest RPS value for disease resistance of 100% (at Day 6) and 36% (at Day 4) in treated shrimp against viral and bacterial infection, respectively. Mortality of PG-supplemented diets in treated shrimps against WSSV infection was also found to be much lower (P < 0.05) than that of the control group.