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G Kang

Publications and source records attributed to G Kang.

At least 37 records · Page 2Linked to original sources

Characterisation of rotavirus G9 strains isolated in the UK between 1995 and 1998.

G9P[6] and G9P[8] rotavirus strains were identified during 1995/96 through the molecular epidemiological surveillance of rotavirus strains circulating in the UK between 1995 and 1998. An increase in the incidence and spread of sporadic infections with rotavirus genotype G9P[8] across the UK was detected in the two following seasons. Partial sequencing of the VP7 gene showed that all the UK strains shared a high degree of homology and were related very closely to G9 strains from the US and from symptomatic infections in India (> or =96% homology). The UK strains were related more distantly to the apathogenic Indian strain 116E (85-87.8% homology). Phylogenetic analysis revealed clustering of the UK strains into 3 different lineages (I to III) and into two sub-lineages within lineage I. There were correlations between VP7 sequence clustering, the P type and the geographical origin of the G9 strains. Partial sequencing of the VP4 gene showed high degree of homology (>98%) among all the P[6] strains, and the sequences obtained from the P[8] strains clustered into 2 of the 3 global lineages described for P[8] strains associated with other G types. These data suggest that G9 strains may be a recent importation into the UK, and that G9P[8] strains may have emerged through reassortment in humans between G9P[6] strains introduced recently and the more prevalent cocirculating G1, G3 and G4 strains that normally carry VP4 genes of P[8] type.

Aged↗

Familial intrahepatic cholestatic cirrhosis with positive antimitochondrial antibody: familial primary biliary cirrhosis.

We present three siblings (out of four) with intrahepatic cholestatic disease and cirrhosis. Two of the siblings, a 33-year-old woman and a 34-year-old man had advanced liver disease- with the liver histology showing established cirrhosis with chronic cholestasis and excess copper accumulation. Both died two years later due to hepatic encephalopathy. The third sibling, a 37-year-old man on routine check-up was found to have abnormal liver functions. The liver biopsy showed marked bile ductular proliferation with bridging fibrosis, reduction in interlobular bile ducts, and excess copper accumulation. The presence of antimitochondrial antibody in the serum in 1 in 320 dilutions in all three patients and 1 in 80 dilutions in the oldest healthy sibling and hypergammaglobulinemia in all the siblings confirmed the diagnosis of familial primary biliary cirrhosis. Antinuclear and smooth muscle antibodies were not present. Clinical and biochemical improvement has been noted in the third sibling after therapy with ursodeoxycholic acid.

Adult↗

Rat hepatocellular apoptosis induced by glycodeoxycholate.

OBJECTIVE: To explore the relationship between glycodeoxycholate (GDC) and rat hepatocellular apoptosis. METHODS: GDC was used to treat rat hepatocytes cultured in vitro and the apoptotic cells were observed and analyzed with light microscope, transmission electron microscope, TUNEL in situ hybridization, DNA agarose gel electrophoresis and flow cytometry. RESULTS: When rat hepatocytes were incubated with GDC (final concentration of 100 micromol/L) for 2h, apoptotic hepatocytes were observed with light and transmission electron microscope, and TUNEL in situ hybridization. When the hepatocytes were incubated with GDC (final concentration of 50, 100, 150 micromol/L, respectively) for 2h, or with GDC (final concentration of 100 micromol/L) for 2, 4, 6, 8h, respectively, agarose gel electrophoresis of the hepatocytes DNA demonstrated the typical ladder patterns. CONCLUSION: GDC with final concentration of 50, 100, 150 micromol/L could induce rat hepatocellular apoptosis.

Animals↗

[Glycodeoxycholic acid changes the membrane fluidity and superoxides of lipids in hepatocytes].

OBJECTIVES: To explore the mechanisms of hepatocyte injury caused by glycodeoxycholic acid (GDCA) through studies on the roles of GDCA to membrane fluidity and superoxides of lipids of hepatocyte. METHODS: GDCA was used to treat hepatocytes of rat cultured in vitro and changes in cell membrane fluidity and malondialdehyde(MDA) were observed. RESULTS: In the presence of GDCA (final concentration of 250 mumol/L), the concentration of hepatocyte MDA of GDCA increased significantly (P < 0.001) and membrane fluidity decreased (P < 0.02) after culture of 1 or 4 hours. ALT was directly related to MDA and fluorescence polarization (P), r was 0.945 and 0.986, respectively. CONCLUSION: GDCA can induce the increase of MDA and decrease of fluidity of hepatocyte membrane, and finally cause hepatocyte injury.

Animals↗

Enteric pathogens in southern Indian HIV-infected patients with & without diarrhoea.

This study was undertaken to determine the carriage rate of various enteric pathogens in southern Indian patients with HIV infection, both with and without diarrhoea. Stool from 111 consecutive HIV-positive patients (50 without and 61 with diarrhoea) was examined by microscopy and culture. Jejunal biopsy and fluid examination were carried out if diarrhoea persisted, with negative stool examination. Enteric pathogens were detected from stool in 57.4 per cent of diarrhoeal patients compared to 40 per cent of those without diarrhoea (P > 0.05). Jejunal biopsy and fluid examination provided 11 additional diagnoses. Protozoa accounted for 71.8 per cent of all pathogens isolated. Isospora was significantly more common in patients with (11/61) than in those without (2/50) diarrhoea (P < 0.05). Bacterial pathogens were isolated more commonly from patients with diarrhoea (12/61 compared to 2/50, P < 0.05). Isolation rate of pathogens was higher from patients with diarrhoea for more than 2 wk, compared to those with less than 2 wk duration. Remission of diarrhoea either spontaneously or with symptomatic therapy was observed in 22 patients with acute diarrhoea. A high enteric carriage of a number of pathogens was noted in HIV patients without diarrhoea, but I. belli and bacterial enteropathogens were more likely to be associated with diarrhoea.

Adult↗

Prevalence of enteroaggregative and other HEp-2 cell adherent Escherichia coli in asymptomatic rural south Indians by longitudinal sampling.

Enteroaggregative and other HEp-2 cell adherent Escherichia coli can produce acute and persistent diarrhoea in children and adults, but their prevalence in asymptomatic individuals in the community is not known. In this study, faecal specimens were obtained at 3-4 monthly intervals from 349 subjects constituting a 20% age-stratified sample of a rural community for a period of two years. HEp-2 cell adherent E. coli were found in 210 subjects, and repeat isolations of enteroaggregative E. coli belonging to the same serogroup were found in 12.6% of children less than 12 years of age, indicating that this organism can asymptomatically colonise the intestinal tract. These children may act as a reservoir of infection for the community.

Adolescent↗

Use of serology, the urease test & histology in diagnosis of Helicobacter pylori infection in symptomatic & asymptomatic Indians.

Age-specific prevalence of IgA and IgG antibodies in 714 subjects without gastrointestinal complaints aged 6 months to 90 yr was measured by an enzyme linked immunoassay using an acid-glycine extract of H. pylori as the antigen. The urease test and histology were used for the diagnosis of H. pylori infection in 83 subjects with a clinical diagnosis of dyspepsia, and these results were compared with measurement of IgG, IgA and IgM antibodies. The age specific prevalence of IgG and IgA antibodies respectively was 57 and 43 per cent for subjects aged 6 months to 4 yr and showed an increase with age to a maximum of 90 per cent for IgG in subjects > 60 yr of age and to 87 per cent for IgA in subjects between 51 and 60 yr. In symptomatic patients, there was a high degree of correlation between severity of H. pylori infection on histopathological examination and IgG (P < 0.02) levels. The use of IgG and IgA estimation could have identified H. pylori infection without endoscopy in 50 of the 83 patients. Serology for IgG and IgA antibodies against H. pylori may play a major role in decreasing the need for endoscopy, but cut-off values must be determined for each assay based on the prevalence of antibodies in the population.

Adolescent↗

Salicylate inhibits fimbriae mediated HEp-2 cell adherence of and haemagglutination by enteroaggregative Escherichia coli.

Enteroaggregative Escherichia coli (EAggEC) are associated with both acute and persistent diarrhoea in children. Bowel colonisation due to fimbrial adherence factors appears to play a major role in the disease process. In this study, we investigated the effect of sodium salicylate and 5-aminosalicylic acid on adherence of a type strain and 40 clinical isolates of EAggEC to HEp-2 cells and erythrocytes from different species. Growth in the presence of 10 mM salicylate resulted in markedly decreased adherence to tissue culture cells with 33/40 (82.5%) isolates, and was also associated with inhibition of haemagglutination in 20/33 (60.6%) isolates. Complete or partial inhibition of adherence was also seen in two of five isolates showing localised adherence and three of five isolates with diffuse adherence. Decrease in adherence was associated with decreased or absent expression of fimbriae in 28/40 (70%) of the EAggEC isolates, although production of outer membrane proteins was not affected. Salicylates appear to inhibit adherence mediated by fimbrial adhesins.

Adult↗

Prevalence of intestinal parasites in rural Southern Indians.

OBJECTIVE: To determine the prevalence of intestinal protozoal and helminthic infection in a rural population. METHOD: Seventy-eight members of 15 families from a village were studied. Stool samples from all subjects were examined on alternate days for one month. RESULTS: The overall prevalence rate of various parasitic infections was 97.4%, with only 2 of 78 subjects not excreting parasites in any of their 15 samples. Eighteen (23.1%) persons had only one type of parasite, while 58 (74.3%) excreted multiple parasites. Giardia and Cryptosporidium were the commonest protozoan infections, affecting 42/78 (53.8%) and 31/78 (39.7%), respectively. Hookworm infestations were the commonest helminthic infections, seen in 48/78 (61.5%). Based on excretion patterns, the asymptomatic individuals could be divided into 2 groups of infrequent and frequent excretors, indicating that the host response may determine the level of parasite replication in the gut.

Adolescent↗

Prevalence, in-vitro secretory activity, and cytotoxicity of Aeromonas species associated with childhood gastroenteritis in Chennai (Madras), India.

An investigation on the prevalence of Aeromonas in gastrointestinal illnesses of pediatric inpatients 1 month to 3 years of age was conducted from February 1997 through January 1998 in Madras. Sixteen Aeromonas spp. were isolated from 11 male and five female children among the 341 pediatric inpatients suffering from acute diarrhoea. A. caviae, which was isolated from nine cases, was found to be the most predominant isolate, followed by A. veronii biovar sobria, isolated from six cases, and A. hydrophila, isolated from one case. Shigella flexneri was recovered along with Aeromonas veronii biotype sobria serotype 035 from one 5-month-old female child. We did not notice any seasonal pattern in the association between Aeromonas and childhood gastroenteritis. None of the 147 stool samples obtained from age-matched non-diarrhoeic control children yielded Aeromonas spp. Isolation of Aeromonas spp. from patients suffering from gastroenteritis was found to be significant (chi 2 = 7.1312; P = 0.008, < 0.01). Among the 16 Aeromonas isolates, seven isolates of A. caviae and two isolates of A. veronii biovar sobria induced a secretory response in rabbit intestinal mucosa mounted in Ussing chambers as demonstrated by a significant increase in the short circuit current. Nine of the 16 Aeromonas isolates, including three isolates of A. caviae, five isolates of A. veronii biovar sobria, and the solitary isolate of A. hydrophila were also cytotoxic to CHO cells. Five of the six isolates of A. veronii biovar sobria and the A. hydrophila isolate produced hemolysin. The results of this study indicate that Aeromonas species are important causative agents of diarrhoea in childhood gastroenteritis and are prevalent throughout the year in Madras.

Aeromonas↗

Oxidative stress response in Shigella & nonpathogenic gut bacteria.

The effect of oxidative stress in the form of exogenous H2O2 on the survival of four species of Shigella and two nonpathogenic Gram negative gut bacteria and the role of catalase as an antioxidant enzyme, neutralizing the effect of H2O2 were examined. A significant decrease in the number of colony forming units (CFUs) after exposure to exogenous H2O2 (122 +/- 37), compared to control bacteria (218 +/- 63, P < 0.001) was observed. There was an induction of catalase activity after exposure to exogenous H2O2 and the specific activity of catalase in H2O2 exposed bacteria was significantly increased (2.88 +/- 1.25), compared to control bacteria (1.5 +/- 0.44; P < 0.05). A direct correlation was observed between the decrease in bacterial counts and increase in catalase activity after exposure of H2O2 (regression coefficient (0.56). Gut bacteria appear to be susceptible to oxidative stress and inducible catalase activity may form an important part of the antioxidant defence mechanism against oxidative stress.

Catalase↗

An epidemic of diarrhoea in south India caused by enteroaggregative Escherichia coli.

A diarrhoeal epidemic in a village close to Vellore was investigated in January 1996. Faecal samples were obtained from 20 subjects with diarrhoea and from 11 individuals without diarrhoea (controls) and were examined for bacterial, viral and parasitic enteropathogens. Water samples from all sources in the village were analysed. The epidemic affected all age groups (overall attack rate 15%). The mean duration of diarrhoea was 11 days. Individuals who consumed water exclusively from a borewell had a lower relative risk (RR) of disease (0.14, 95% Cl 0.02-1.01) compared to users of two open wells (RR 6.93, Cl 0.99-48.66 and RR 7.81, Cl 1.02-59.79, respectively). No conventional bacterial enteropathogens were isolated from the stool samples. Enteroaggregative Escherichia coli (EAggEC) were identified in the stool of 11 of 20 subjects with diarrhoea, and in 1 of 11 control samples (P = 0.02). All the EAggEC isolates from the patients had identical antibiotic sensitivity patterns and produced a toxin in Ussing chamber studies. Serotyping indicated that all the EAggEC from individuals with diarrhoea belonged to one or other of two serotypes. All water samples had high coliform counts and E. coli were cultured from the two open wells but not from the borewell. The evidence suggests that EAggEC was responsible for this outbreak of diarrhoea. EAggEC should be considered as a possible pathogen in unexplained diarrhoeal outbreaks in developing countries.

Adolescent↗

An outbreak of food poisoning in Tamil Nadu associated with Yersinia enterocolitica.

An outbreak of food poisoning in a Tamil Nadu village, affecting 25 of 48 individuals who participated in a feast, was investigated. The risk of developing illness was associated with consumption of buttermilk (relative risk 3.8). None of the food items consumed during the feast was available for analysis. Toxin-producing Y. enterocolitica (serotype 3, biotype 4) was grown from 1 of 11 stool samples from affected individuals, as well as from a water sample from the source used to dilute the buttermilk. High titres of antibody of Yersinia were detected in 2 of 12 patients but in neither of the two groups of controls. Toxin production was noted in buttermilk incubated for 6 h with Y. enterocolitica. This is the first report from India of a food poisoning outbreak associated with this organism.

Adolescent↗

Isolation of Vibrio cholerae O139 from the drinking water supply during an epidemic of cholera.

In mid-1994, the public water supply was investigated in a medium-sized town in south India during an epidemic of cholera due to Vibrio cholerae O139. Vibrio cholerae O139 was isolated from the public water supply including one of the wells supplying the town, the central overhead tank, and domestic taps connected to the public supply. Following chlorination, the organism was no longer isolated from the water supply and the epidemic subsided. This demonstration of V. cholerae O139 in the drinking water supply of a town underlines the need for adequate treatment of the water supply.

Adolescent↗

A comparison of five staining methods for detection of Cryptosporidium oocysts in faecal specimens from the field.

Five staining methods for identification of Cryptosporidium oocysts in faecal smears were evaluated using samples obtained from asymptomatic south Indian villagers of all ages. The safranine-methylene blue technique was used as the gold standard and compared with 2 methods each using auramine and mepacrine, with potassium permanganate and carbol fuchsin as counterstains. All five methods identified all samples containing cryptosporidium oocysts, however false positive identifications were obtained by the standard auramine-phenol-potassium permanganate method. The auramine-carbol fuchsin and the mepacrine-carbol fuchsin techniques are the simplest and most rapid of the five methods compared. The mepacrine-carbol fuchsin technique is recommended for screening large numbers of stools, since it does not stain yeasts, is cheaper and less toxic than auramine.

Animals↗