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Biomedical subjects

Y Kohli

Publications and source records attributed to Y Kohli.

At least 55 records · Page 3Linked to original sources
PubMed1995

Genetic differences between duodenal ulcer patients who were positive or negative for Helicobacter pylori.

This study investigated genetic differences between Helicobacter pylori-positive and -negative duodenal ulcer patients. Seventy-two patients with duodenal ulcer (61 H. pylori positive and 11 H. pylori negative) were examined for HLA-DQA1 genotype. The allele frequency of DQA1*0102 was higher in H. pylori-negative than in H. pylori-positive patients. Moreover, the genotypes that possessed the DQA1*0102 allele were significantly more common in H. pylori-negative than in H. pylori-positive patients. In contrast, the allele frequency of DQA1*0301 was lower in H. pylori-negative than H. pylori-positive patients. The genotypes that possessed DQA1*0301 were significantly more common in H. pylori-positive than in H. pylori-negative patients. These results suggest that there are genetic differences between H. pylori-positive and -negative duodenal ulcer patients and that immunogenetic factors for susceptibility or resistance to H. pylori infection exist in the host.

Adolescent↗
PubMed1994

Secretion of human intracellular aspartic proteinase cathepsin E expressed in the methylotrophic yeast, Pichia pastoris and characterization of produced recombinant cathepsin E.

The human gastric cathepsin E (CTSE), a dimeric aspartic proteinase, was expressed in the methylotrophic yeast Pichia pastoris by placing the CTSE cDNA under the control of the methanol inducible alcohol oxidase promoter. The human CTSE expressed in P. pastoris was secreted into the culture medium as an active enzyme directed by its native signal sequence despite its intracellular localization in mammalian cells. The time course analysis of the culture supernatant of the P. pastoris transformant expressing human CTSE revealed that the recombinant human CTSE was secreted as a 90 kDa molecule and then converted via an 84 kDa intermediate to an 82 kDa mature molecule. A large-scale culture of the transformant was performed in a high cell density fermentor and the recombinant human CTSE was highly purified from the culture supernatant. The purified recombinant cathepsin E had the molecular mass of 82 kDa with the amino-terminal sequence starting with Ile37 of the sequence deduced from its cDNA sequence, suggesting that the human cathepsin E was accumulated in the culture supernatant as mature dimeric enzyme. The result of endoglycosidase-H digestion followed by Western blot analysis of the purified recombinant cathepsin E suggested that the human cathepsin E expressed in P. pastoris received N-linked high-mannose type glycosylation. The enzymatic properties of the recombinant enzyme were comparable to those of natural human CTSE.

Base Sequence↗
PubMed1994

High prevalence of neutralizing activity to Helicobacter pylori cytotoxin in serum of gastric-carcinoma patients.

Helicobacter pylori infection is causally related to chronic type-B gastritis, and may also be associated with an increased risk of gastric carcinoma. Vacuolating cytotoxin, which is an 87-kDa protein secreted by H. pylori, induces eukaryotic cell vacuolation in vitro. To determine whether there is an association between H. pylori vacuolating cytotoxin and gastric carcinoma, we investigated several characteristics of H. pylori infection, i.e., isolation of H. pylori from gastric biopsies, antibodies specific for H. pylori, detection of neutralizing activity to vacuolating cytotoxin in serum and immunological detection of cytotoxin by serum. Out of 6 sera from gastric-carcinoma patients, all showed the neutralizing activity to vacuolating cytotoxin, in contrast to 3 of 5 sera from peptic-ulcer patients. Normal individuals showed no neutralizing activity. All sera possessing the neutralizing activity recognized an 87-kDa protein band by Western blot analysis. Our results confirmed that cytotoxin-neutralizing activity in human sera was associated with immunodetection of an 87-kDa protein. To further evaluate neutralizing activity in serum from gastric-carcinoma patients, we retrospectively analyzed frozen-stocked serum samples from 22 gastric-carcinoma patients. Sera from 21 of these 22 patients exhibited neutralizing activity. These sera were also checked for antibodies to H. pylori, using an ELISA; 16 sera showed positive results. Our results indicate that detection of cytotoxin-neutralizing activity in sera is strongly associated with H. pylori infection, and probably with gastric carcinoma, and is also of interest in the diagnosis of H. pylori infection.

Adult↗
PubMed1994

Influence of ammonia solution on gastric mucosa and acetic acid induced ulcer in rats.

Aqueous ammonia in concentrations of 0.02 or 0.1% was continuously administered to rats to study its effect on the gastric mucosa histologically and cell kinetically. Furthermore, acetic acid ulcer, which is a model of chronic gastric ulcer, was experimentally induced in the stomachs of rats to assess the influence of 0.02% ammonia on the course of this ulcer. Male Donryu rats were divided into three groups given 0.02% ammonia, 0.1% ammonia or tap water. On several occasions (1, 3 and 5 days and 1, 4, 8, 12 and 24 weeks from the beginning of the experiment), the gastric mucosa in the fundic gland region and the antrum was examined histologically, and from the viewpoint of cell kinetics. The assessment in the 8th and 24th weeks employed the double labeling technique with bromodeoxyuridine and 3H-thymidine. The assessment on the other occasions used the flash labeling technique with bromodeoxyuridine. Both the 0.02% and 0.1% ammonia treatment groups showed a decrease in PAS-positive mucus and an enhanced cell cycling in the early stage of the experiment. After long periods of treatment, these groups showed a reduction in the gland height, a recovery in PAS-positive mucus and a suppression of cell cycle, suggesting direct toxicity of ammonia on the gastric mucosa. Although glandular atrophy was observed in these animals, infiltration of inflammatory cells was not observed. Thus, the relationship between ammonia and gastritis remained obscure. No ulcer developed in any group. Subsequently, we experimentally induced Ul-IV or Ul-V acetic acid ulcers in the stomachs of rats, according to the method of Okabe et al. (1971, 1972). These rats were divided into two groups given 0.02% ammonia or tap water. In the 4th and 8th weeks of the experiment, the stomachs of these rats were examined histologically and from the viewpoint of cell kinetics. The 0.02% ammonia treatment group showed a significant increase in the ulcer index (long diameter x short diameter; mm2) in the 4th and 8th weeks. This group also showed suppressed cell cycling of the regenerative epithelium and fibroblasts in the ulcer margin, suggesting direct toxicity of ammonia. Thus, healing of peptic ulcer was delayed by continuous administration of 0.02% ammonia.

Acetates↗
PubMed1994

[Effectiveness of interferon, glycyrrhizin combination therapy in patients with chronic hepatitis C].

SNMC (stronger Neominophagen C), whose active component is glycyrrhizin (a saponin extracted from licorice) has been utilized to improve the liver function in Japan. To assess the effectiveness of interferon (IFN), SNMC combination therapy in patients, who did not respond to IFN therapy alone, we investigate 28 patients with histology of CAH 2B at 12 weeks after IFN administration. 15 patients received IFN alone continuously (group A), and 13 patients received IFN with SNMC (group B) for 12 weeks thereafter. Normalization of serum ALT level was observed in 33.3% of group A and in 64.3% of group B. Disappearance of serum HVC RNA was 13.3% in group A and 38.5% in group B. But these data were not significant statistically. Histological improvement was not significant, between group A and B by Knodel's HAI score, but reversal of histological grade (Europe classification) was noted more frequently in group B. A case of posttransfusion hepatitis type C, exacerbated by IFN therapy is reported. HLA class I antigen was strongly expressed in the liver tissue after administration of IFN. In this case, potentiation of cellular immunity was thought to be the cause of the exacerbation and IFN, SNMC combination therapy was useful in improving liver function.

Adult↗
PubMed1994

Early progression stage of malignancy as revealed by immunohistochemical demonstration of DNA instability; I, Human gastric adenomas.

The degree of DNA-instability as revealed by the immunohistochemical staining with monoclonal anti-single-stranded DNA antibody after acid hydrolysis (DNA-instability test) was used as the marker of malignancy. This was applied to human gastric regenerative epithelium in chronic peptic ulcer (5 cases), adenoma (35 cases), and well differentiated tubular adenocarcinoma (5 cases). Proliferative activity was evaluated by proliferating cell nuclear antigen (PCNA) immunohistochemistry, and the quantitative analyses of the mean number and mean area of silver-stained nucleolar organizer regions (AgNORs) per one nucleus were performed for all these cases. All cancers and adenomas were positively stained by the DNA-instability test diffusely, indicating the malignant character of the latter from the view point of DNA-instability, in contrast to the negative stainability of all regenerative epithelium. The percent number of PCNA-positive cells and mean number and mean area of AgNORs tended to be larger in adenoma and cancer than in regenerative epithelium, although the differences were not usually statistically significant. Supporting the malignant character of adenoma, single cell necroses and abnormal mitoses were almost always present in the lesion. In conclusion, all adenoma lesions were regarded as malignant in nature, namely, in-situ carcinoma, existing at an early stage of progression of malignancy.

3,3'-Diaminobenzidine↗
PubMed1994

Vacuolating cytotoxin production by Helicobacter pylori isolates from peptic ulcer, atrophic gastritis and gastric carcinoma patients.

OBJECTIVE: We investigated the production of vacuolating cytotoxin by Helicobacter pylori isolates from patients with peptic ulcer, atrophic gastritis or gastric carcinoma in order to examine the pathophysiological significance of vacuolating cytotoxin in these diseases. METHODS: H. pylori was isolated from 18 patients (five with peptic ulcers, seven with atrophic gastritis and six with gastric carcinoma). Culture supernatants of H. pylori isolates, concentrated 20-fold, were serially diluted and then analyzed for cytotoxin activity semi-quantitatively using A431 cells as indicator cells. The relative activity of vacuolating cytotoxin was defined according to the maximum dilution. RESULTS: Cytotoxin production was observed in two out of five, six out of seven and six out of six isolates from peptic ulcer, atrophic gastritis and gastric carcinoma patients, respectively. The mean relative activity was calculated as 0.80, 2.71 and 2.50 in CONCLUSION: These results suggest that vacuolating cytotoxin-producing H. pylori is strongly associated with both atrophic gastritis and gastric carcinoma.

Adult↗
PubMed1994

Helicobacter pylori an chronic atrophic gastritis.

Phenol red dye spraying endoscopy, in addition to a biopsy study, was employed for the determination of Helicobacter pylori distribution on the gastric mucosa of 108 patients with no gross gastric findings. The sensitivity of this method was 100%, and its specificity was 84.6%. In patients with a C0 pattern of the fundic-pyloric (F-P) border, the H. pylori-positive rate was only 21%, but this increased with the spread of atrophic mucosa, to approximately 90%. However, in patients with an O3 pattern, H. pylori could not be found. In addition, in 24 (80.0%) of 30 patients with no glandular atrophy, this organism was not found, while, in contrast, the organism was demonstrated in 54 (85.8%) of 63 patients with a slight degree of glandular atrophy. In patients with severe mucosal atrophy accompanying intestinal metaplasia, however, the organism was not found. One-half of the patients examined were followed up, using this technique. In those who were H. pylori-negative, glandular atrophy remained unchanged, while advanced glandular atrophy was seen in 10 (28.6%) of 35 H. pylori-positive patients. A cephalad shift of the F-P border was observed in 20 (57.1%) of these 35 H. pylori-positive patients, while in those who were negative, the F-P border remained unchanged, with one exception.

Adult↗
PubMed1993

Meiotic behavior and linkage relationships in the secondarily homothallic fungus Agaricus bisporus.

This study followed the transmission of 64 segregating genetic markers to 52 haploid offspring, obtained from both homokaryotic and heterokaryotic meiospores, of a cross (AG 93b) of Agaricus bisporus, the commonly cultivated "button mushroom." The electrophoretic karyotypes of the AG 93b component nuclei were determined concurrently (n = 13). Eleven distinct linkage groups were identified by two-point analysis. DNA-DNA hybridization showed that nine of these corresponded to unique chromosome-sized DNAs. Two other chromosomal DNAs were marked with nonsegregating markers, including the rDNA repeat. Two remaining chromosomes remained unmarked but hybridized to repeated-sequence probes. Cross 93b had an essentially conventional meiosis in which both independent assortment and joint segregation of markers occurred, but in which crossing over was infrequent over much of the mapped genome. The 48 homokaryotic spore-offspring had overall crossover frequencies that were similar to, but possibly slightly less than, those of three homokaryon constituents of heterokaryotic spore-offspring. These daa provide support for our earlier cytogenetic model of sporogenesis in A. bisporus, that explains why heterokaryotic spore-offspring usually appear to exhibit no recombination. No evidence favoring an alternative, mitotic model of sporogenesis was found. The resulting genetic map appears to survey the genome extensively and for the first time permits localization of loci determining economically important traits in this fungal crop species. Large differences in the vigor of homokaryotic offspring were correlated with the inheritance of certain chromosome segments and were also often associated with significant departures from Mendelian segregation ratios.

Agaricus↗
PubMed1993

Early progression stage of malignancy of human colon border-line adenoma as revealed by immunohistochemical demonstration of increased DNA-instability.

The degree of DNA-instability was used as the marker of malignancy and applied to adenoma (7 benign cases and 17 border-line cases) and cancer (8 carcinoma-in-adenoma cases and 17 invasive cancer cases) of human colon. Proliferative activity by PCNA index and the activity of protein synthesis by AgNORs were also estimated for all cases as the supporting markers of malignancy. In all border-line cases, the following findings were obtained: (1), the degree of DNA-instability as revealed by immunohistochemical staining with anti-single-stranded DNA antiserum after acid hydrolysis was increased in border-line adenoma to the level of invasive overt cancer, indicating its malignancy with marked DNA-instability; (2), reflecting the malignant character, abnormal mitosis and single cell necrosis were usually observed in all border-line adenomas by fluorescent Feulgen staining, indicating the DNA alterations; (3), not only the parenchymal but also the stromal PCNA indices were statistically larger in border-line adenoma than in benign adenoma, indicating the "stromal activation" in malignancy; (4), the volumes of AgNORs were much increased in border-line adenoma in comparison with those in benign adenoma, and these showed further increases with the progression of malignancy to the invasive overt cancer. These findings indicate that border-line adenoma of human colon has already malignant character at the early progression stage, although no apparent epithelial atypia, or destructive invasion, is taking place.

Adenoma↗
PubMed1993

[Endoscopic diagnosis of Helicobacter pylori distribution in human gastric mucosa by phenol red dye spraying method].

Helicobacter pylori (H. pylori) is known to show an uneven and patchy distribution on human gastric mucosa, close association with chronic gastritis and peptic ulcer diseases. The aim of this study was to clarify the distribution of this organism under direct vision by phenol red dye spraying endoscopy. In order to maintain gastric pH around pH 4.0 to 5.0, premedication was necessary either by intravenous injection of H2-blocker, 30 min before the test, or by oral administration of Omeprazole 20 mg or a half dose of H2-blocker before bedtime the day before the test. After that, 0.05% phenol red solution, containing 0.5 M urea, was sprayed onto the gastric mucosal via a teflon tube inserted through the endoscope. This technique was useful to clarify the distribution of H. pylori in the stomach in vivo and, it was possible to clinically study the role of H. pylori in upper G-I tract disorders, by this new technique.

Chronic Disease↗
PubMed1992

A case of duodenal carcinoma presenting as a submucosal tumor.

This paper describes a patient with duodenal carcinoma showing the features of a submucosal tumor, leading to difficulty in making an accurate preoperative diagnosis. A 63-year-old woman was admitted for investigation of a duodenal mass. An examination of the upper gastrointestinal tract revealed a semicircular compression of the stomach and the duodenum. Endoscopy of the stomach and duodenum disclosed a hemispherical tumor with a deep ulcer in the apex. Computer tomography revealed a tumor of about 5 cm in diameter at the same site. Laparotomy was performed under the tentative diagnosis of a submucosal tumor. A tumor was found occupying the duodenum, which compressed the gastric antrum exteriorly, and was also adherent to the head of the pancreas by direct invasion. A curative resection was performed by combining a pancreatoduodenectomy with a transverse colectomy along with regional lymph node clearance. A microscopic examination showed that the tumor contained neoplastic cells growing in a tubular pattern, particularly in its peripheral regions. Thus, this lesion was finally diagnosed as primary adenocarcinoma of the duodenum.

Adenocarcinoma↗
PubMed1992

Importance of acidic mucin secretions by foveolar and mucous neck cells of rat fundic mucosa as the defence mechanisms against HCl as revealed by fasting.

The localization of neutral mucin and acidic mucins in both control and fasted rat gastric fundic mucosa were examined by microscopic and electron microscopic histochemical methods. By Carnoy's fixation, the surface mucous coat of the control rat gastric fundic mucosa was found to be composed of alternating layers of acidic mucins and neutral mucin, indicating the synchronous and cyclic secretions of them. In many gastric pits of the fundic glands, the acidic mucins were found to spring out from the deep foveolar regions like volcanoes. This phenomenon may suggest that the acidic mucins play a fundamental role in protecting the pit cells against HCl during its passage, and the layers of neutral mucin and acidic mucins in the surface coat is the safeguard against the HCl and digestive enzymes in the gastric lumen. In the fasting rat gastric fundic mucosa, the acidity and the amount of the gastric juice were markedly decreased, indicating the suppressed secretions of mucins and HCl. The decreased production of sulfomucin was directly demonstrated by 35SO4-autoradiography. Many mucous neck cells existing in close association with the parietal cells were ballooned due to accumulation of alcian blue (AB)-positive but high iron-diamine (HID)-negative sialomucin, which was not demonstrable in the control. The secretory granules of sialomucin contained in the ballooned mucous neck cells were positively stained ultrastructurally with cacodylate-ferric colloid to stain acid mucopolysaccharides.

Acid Phosphatase↗
PubMed1992

Genetic disease patterns in Japan: a review.

Comprehensive genetic studies in which the genetic structure of a population is considered against the background of ecological factors, including environmental and social variables, often supply valuable information for the solution of a number of problems in human biology, including reproductive compensation and inbreeding depression. In the first section of this paper we consider the incidence of genetic diseases in Japan in reference to other populations. Some of the genetic disorders found elsewhere do not occur or are of lower frequencies in Japan. On the other hand, a number of genetic diseases occur at higher than usual frequencies, leading to an incidence of genetic disease of the order of about 1 per 100 in newborn Japanese. We next review the studies of consanguinity in Japan and report evidence of very high levels, ranging from 8.6% to 58.0%, for villages during the early part of the twentieth century. The rates are declining rapidly for the country but, because of traditional social values, inbreeding rates remain significant in many small villages. In the final section we consider the probable trends in the frequency of inbreeding on a worldwide basis and point out that frequencies of certain genetic diseases are likely to remain high and even increase in some societies because of various socially prescribed mating patterns.

Consanguinity↗