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H H Yoshimura

Publications and source records attributed to H H Yoshimura.

13 recordsLinked to original sources
PubMed1993

DNA-DNA hybridization demonstrates apparent genetic differences between Helicobacter pylori from patients with duodenal ulcer and asymptomatic gastritis.

We asked whether different clinical outcomes of Helicobacter pylori infection might be a reflection of genetic differences in infecting organisms. Using DNA-DNA hybridization we examined whether hybridization levels grouped H. pylori isolates corresponding to the type of disease (gastric ulcer, duodenal ulcer, asymptomatic gastritis) from which they were recovered. Target DNAs were prepared from H. pylori strains cultured from gastric biopsy specimens of 25 patients; 5 with gastric ulcers, 9 with duodenal ulcers, and 11 from asymptomatic volunteers endoscopically proven not to have peptic ulcer disease. DNA-DNA hybridization was performed with whole genomic probes made from an isolate from each of the three disease categories. Using a DNA probe from an isolate from a duodenal ulcer patient, we found that isolates from patients with duodenal ulcer and nonulcer gastritis yielded significant differences in levels of hybridization. The levels of hybridization of DNA from H. pylori isolates from duodenal ulcer patients, gastric ulcer patients, and nonulcer gastritis controls were 85.5% +/- 7%, 83% +/- 3%, and 78.3% +/- 5%, respectively (mean +/- SD), and the difference between the hybridization levels obtained with duodenal ulcer and nonulcer control target DNAs was statistically significant (P = 0.025). These data suggest that the outcome of infection (eg, ulcer or no ulcer) may be due to virulence factors encoded by genomic DNA. If such differences exist, it should be possible to produce probes that would identify the ulcer virulence gene(s) and clearly distinguish between ulcerogenic and nonulcerogenic strains of H. pylori.

DNA Probes↗
PubMed1989

In vivo susceptibility of Campylobacter pylori.

Campylobacter pylori infection has been associated with duodenal ulcer, gastric ulcer, and non-ulcer dyspepsia. Although in vitro studies have shown that C. pylori is susceptible to most commonly used antibiotics, predictions from in vitro sensitivity studies have not led to a safe and generally effective therapy; C. pylori has proved to be very difficult to eradicate in vivo. We used the urea breath test to assess the susceptibility of C. pylori in vivo to various drugs. C. pylori was susceptible to bismuth subsalicylate, bismuth subnitrate, and furazolidone. C. pylori was not susceptible (i.e., urease activity remained despite administration of the drug) to the following drugs: 1) antiulcer agents (cimetidine, ranitidine, famotidine, omeprazole, misoprostol, sucralfate, liquid antacids); 2) NSAIDs (aspirin, indomethacin, ibuprofen, naproxen, tolmetin); 3) antibiotics (oral penicillin V, trimethoprim-sulfamethoxazole, dicloxacillin); 4) salts (lithium, ferrous sulfate, gold); 5) miscellaneous (acetaminophen, phenytoin, hydrochlorothiazide, propranolol, metoprolol, metoclopramide, ursodeoxycholic acid). Oral antimicrobials can be administered directly onto the site of infection, so that a very low oral dose will provide many multiples of the in vitro minimal inhibitory concentration. Furazolidone suspension (7 mg) was administered seven times daily (daily dose 49 mg) to three individuals infected by C. pylori during suppression of gastric acid secretion with famotidine (40 mg bid). After 4 days, all subjects had significant reductions in urease activity (two to normal and one to a borderline value). This response suggested that very low-dose therapy may be useful either alone or combined with bismuth. Conclusive establishment of an etiologic (or major contributory) relationship of C. pylori to ulcer disease will require a safe and reliable method to eradicate the organism from the stomach and duodenum.

Anti-Bacterial Agents↗
PubMed1988

Nucleic acid hybridization studies of mycobactin-dependent mycobacteria.

Using molecular techniques, specifically, DNA-DNA hybridization in solution and measurement of the thermal stabilities of hybrids, we examined the genetic relationships among mycobactin-dependent mycobacteria and between such organisms and other (mycobactin-independent) mycobacteria. The mycobactin-dependent mycobacteria examined included five strains of Mycobacterium paratuberculosis, two wood pigeon isolates, and one bovine isolate that was biochemically identified as Mycobacterium avium. All mycobactin-dependent mycobacteria were found to belong to the same hybridization group and to be closely related to organisms in M. avium complex serovars 2, 8, and 9, but more distantly related to organisms in serovars 7 and 19. Relatively low levels of hybridization were observed with other mycobacterial species examined. Thus, these results provide genetic evidence to support previous biochemical and cultural evidence that indicated that mycobactin-dependent mycobacteria constitute a closely related group of organisms within the M. avium complex.

Animals↗
PubMed1988

Progress in culture and subculture of spheroplasts and fastidious acid-fast bacilli isolated from intestinal tissues.

The efficiency of culture media was compared for the culture and subculture of very slowly growing acid-fast bacilli and spheroplast forms obtained from intestinal tissues of patients with Crohn's disease and ulcerative colitis and from controls without inflammatory bowel disease. Media were developed by modifying a nutrient broth medium based on veal infusion broth and yeast extract. We evaluated the effects of pH and the addition of Tween 80, Dubo oleic albumin complex, an extract from intestinal tissue from a patient with Crohn's disease, horse serum, sucrose, magnesium sulfate, ferrous ammonium sulfate, and sodium citrate. All media contained mycobactin J (2 micrograms/ml). We developed a medium (MG3) which was highly successful in promoting the growth of very fastidious organisms and promoted reversion of spheroplasts to acid-fast rods. MG3 contained veal infusion broth, 1% yeast extract, 10% horse serum, 0.3 M sucrose, 0.2% MgSO4, 0.1% ferrous ammonium sulfate, 0.1% sodium citrate, and 2 mg of mycobactin J per liter. We were able to obtain quantities of organisms sufficient for examination of the organisms by molecular techniques. Successful cultivation of all isolates and reversion of spheroplasts to acid-fast forms encourage further studies of the possibility of a complex association of mycobacteria and Crohn's disease.

Crohn Disease↗
PubMed1988

Epidemiology of Campylobacter pylori infection: ethnic considerations.

A proper perspective of the association of Campylobacter pylori with various diseases can be achieved only when the incidence of C. pylori infection in the normal population is known. We used the 13C urea breath test (a simple, specific, noninvasive, safe, and reproducible method to assess the presence of active C. pylori infection) to compare the frequency of C. pylori infection in healthy young adults from three areas of the world. We studied 26 women and 32 men (ages 20 to 29): 29 from the United States, 10 from China, 6 from Mexico, and 13 from India. All foreign nationals had been in the United States 5 years or less. The frequency of C. pylori infection was 21%, 67%, 33% and 46%, for those from the U.S., China, Mexico and India, respectively. Although, we found no difference in the frequency of C. pylori infection among ethnic groups from North America (U.S. citizens compared with citizens of Mexico), all individuals studied were of middle to upper class socioeconomic status. Subsequent studies will investigate whether the prevalence of C. pylori infection is different in economically disadvantaged populations. Our results suggest that there may be major differences in the age-related frequency of C. pylori infection in individuals from different parts of the world.

Adult↗
PubMed1988

Iatrogenic Campylobacter pylori infection is a cause of epidemic achlorhydria.

On a number of occasions, there have been descriptions of epidemic achlorhydria in subjects undergoing repeated gastric secretory studies, typically as part of research protocols. We observed a case in a 37-yr-old healthy man undergoing weekly gastric analyses, along with endoscopy and gastric biopsy, as part of a research protocol studying gastric adaptation to aspirin. In the middle of the 2nd wk of aspirin administration, he developed severe nausea and epigastric discomfort. Aspirin administration was discontinued, but, as per protocol, gastric analyses, endoscopies, and biopsies were continued. Compared to the week preceding the acute illness, biochemical analyses showed a transient 7.4-fold increase in basal gastric acid, 3.6-fold increase in pepsin secretion, 8.8-fold increase in DNA loss, 5.6-fold increase in mucus secretion, and 12-fold increase in gastric bleeding. Basal acid secretion was zero, and pepsin secretion was one-third of control during the 2nd wk of the infection. Endoscopy at the time of symptoms showed erosions in the gastric body and antrum, as well as numerous mucosal hemorrhages and an acute ulcer in the antrum. Endoscopy 7 days later revealed that the gastric mucosa had almost completely recovered, with only a shallow erosion seen at the site of the previous ulcer. Gastric biopsies were normal before and during the first 2 wk of aspirin ingestion. Gastric biopsies taken at the time of the acute illness (associated with increased basal acid secretion) showed marked acute inflammation of the antrum with many Campylobacter pylori bacilli. At that time, neither acute inflammation nor C. pylori were found in biopsies from the body of the stomach. Biopsies obtained 1 wk later (zero basal acid) showed acute inflammation of both the gastric body and antrum. One week later, biopsies from the gastric body showed mild focal acute inflammation, moderate chronic inflammation, and an occasional lymphoid follicle; the gastric antrum showed chronic inflammation. Antral biopsies obtained 2 yr later showed persistent chronic gastritis with prominent lymphoid follicles and scattered foci of acute inflammatory cells; C. pylori bacilli were still present, but were less apparent. We believe that the syndrome of acute (epidemic) gastritis is often iatrogenic C. pylori infection. Our case shows that increased basal acid and pepsin secretion occur before onset of basal acid hypochlorhydria in the acute phase of C. pylori infection.

Achlorhydria↗
PubMed1987

Mycobacteria and inflammatory bowel disease. Results of culture.

We have been able to isolate mycobacteria from intestinal specimens obtained by surgical resection or endoscopic biopsy from patients with Crohn's disease, ulcerative colitis, and noninflammatory bowel diseases. Nineteen slow-growing (Runyon groups I and III) and 17 rapid-growing (Runyon group IV) mycobacterial isolates were obtained. Slow-growing mycobacteria were recovered from approximately one-third of intestinal biopsy specimens from Crohn's disease, one-quarter of ulcerative colitis biopsies, and 40% of biopsies from noninflammatory bowel disease patients. Isolates were most commonly members of the Mycobacterium avium-complex. One isolate (from an ulcerative colitis patient) was biochemically similar to the Mycobacterium strain previously associated with Crohn's disease, and one from a Crohn's disease patient was Mycobacterium kansasii. The rapid-growing organisms were members of the Mycobacterium fortuitum-complex. In addition to conventional mycobacteria, spheroplasts (cell wall-defective forms) were isolated from 12 patients with Crohn's disease (most often from surgically resected colon) and 3 patients with ulcerative colitis; none were isolated from non-inflammatory bowel disease patients. We have been unable to identify a consistent relationship between the presence, or the species, of Mycobacterium and Crohn's disease. Our results do not support the proposed role of a specific mycobacterium in the pathogenesis of Crohn's disease. The cause of Crohn's disease remains unclear.

Colitis, Ulcerative↗
PubMed1987

Investigation of association of mycobacteria with inflammatory bowel disease by nucleic acid hybridization.

We used DNA-DNA hybridization to characterize a mycobacterial isolate, strain Linda, that was obtained from a patient with Crohn's disease and that has been reported to cause ileitis in experimental animals. We also investigated the association of this mycobacterium with Crohn's disease. Our results identified Mycobacterium strain Linda as a strain of Mycobacterium paratuberculosis, the etiologic agent of Johne's disease, a disease of ruminants that has some superficial resemblance to Crohn's disease. Sequences that hybridized with strain Linda DNA probes were detected in DNA extracted from human intestinal tissues from patients with Crohn's disease, ulcerative colitis, and noninflammatory bowel disease. These hybridizing DNA sequences were more prevalent in the muscle layers than in the intestinal mucosa, making it unlikely that they represented DNA from bacterial contaminants in the intestinal lumen. Measurement of the melting temperatures of the DNA-DNA hybrids formed between strain Linda probes and tissue DNAs indicated that the related sequences detected were of mycobacterial origin but were not identical to each other or to strain Linda DNA. These results do not support the proposed specific relationship between Mycobacterium strain Linda and Crohn's disease. The possible etiologic role of mycobacteria in Crohn's disease is discussed.

Colitis, Ulcerative↗
PubMed1986

Mycobacterial aetiology of Crohn's disease: serologic study using common mycobacterial antigens and a species-specific glycolipid antigen from Mycobacterium paratuberculosis.

Crohn's disease is a granulomatous form of enteritis superficially similar to Johne's disease (paratuberculosis) of ruminants. Recently, a Mycobacterium sp closely related to Mycobacterium paratuberculosis was cultured from tissues of patients with Crohn's disease suggesting that M paratuberculosis may be the aetiologic agent in some cases. In addition, greater seroreactivity to M paratuberculosis has been reported in patients with Crohn's disease. In the present study, we have evaluated the serum antibody response to disrupted M paratuberculosis using ELISA and serum specimens from 33 people with Crohn's disease, 21 with ulcerative colitis, and 12 non-inflammatory bowel disease controls. We failed to find a consistent IgG, IgM, or IgA antibody response to Mycobacterium paratuberculosis. The results indicate that, as in bovine paratuberculosis, serum seroreactivity is not a reliable tool for examining the relationship between human intestinal disease and mycobacteria.

Antibody Formation↗
PubMed1984

Search for evidence of a viral aetiology for inflammatory bowel disease.

The aetiology of the inflammatory bowel diseases. Crohn's disease, and ulcerative colitis, is still obscure. A viral aetiology has been proposed, based in part on reports that filtrates prepared from tissues of patients with inflammatory bowel disease induce cytopathic effects in tissue culture cells. Our attempts to culture viruses in many cell lines from filtrates prepared from the tissue of 95 patients have been negative, except for one case in which cytomegalovirus was isolated from the tissue of a Crohn's disease patient. Our studies confirm previous reports that intestinal tissue filtrates induce cytopathic effects in inoculated cell cultures, but the effect we observed is non-specific; cytopathic effects were induced in most cell lines tested and with similar frequency irrespective of whether the intestinal filtrates were prepared from Crohn's disease patients, ulcerative colitis patients, or non-inflammatory bowel disease controls. Electron microscopy studies of tissue culture cells exhibiting cytopathic effects have not revealed virus particles. Characterisation of the cytopathic effect inducing factor showed that it was incapable of serial passage in tissue culture, too small to be a conventional virus, resistant to inactivation by ultraviolet light, and heat stable. Our results suggest that the observed cytopathic effect was caused by a non-replicating cytotoxic factor, or factors, released from intestinal tissues of both inflammatory bowel disease and non-inflammatory bowel disease patients.

Animals↗
PubMed1983

DNA hybridization studies of the association of Pseudomonas maltophilia with inflammatory bowel diseases.

An infectious etiology has been suggested for the inflammatory bowel diseases, Crohn's disease and ulcerative colitis, and an association of cell wall-defective variants of Pseudomonas maltophilia and Pseudomonas-like group Va bacteria with Crohn's disease has been reported by Parent and Mitchell. Seven of the Parent-Mitchell isolates were compared by using DNA hybridization and six were identical and similar, but not identical, to a type strain of P. maltophilia. The seventh isolate showed extensive homology with VARC, a reference strain of group Va organism, but not with P. maltophilia. Pseudomonas DNAs were radiolabeled by nick translation and used as probes for homologous DNA in hybridization experiments involving 48 different tissues. The presence of DNA with sequences homologous to those of P. maltophilia was detected in three of 23 Crohn's disease samples, two of 10 ulcerative colitis samples, and none of 15 control samples. There was no hybridization with VARC or Pseudomonas aeruginosa probes. We were unable to culture cell wall-defective organisms from patients' tissues but have detected pleomorphic organisms in hypertonic cultures of 14 of 53 Crohn's disease specimens, none of six ulcerative colitis specimens, and none of 11 control specimens. None reverted to normal bacteria. These results do not support an exclusive association of P. maltophilia with Crohn's disease but rather suggest a possible association of P. maltophilia with IBD. Technical limitations currently preclude definitive conclusions regarding the significance of this association. Although we demonstrated the presence of DNA sequences with homology to P. maltophilia DNA in tissues of some patients with IBD, the role, if any, of these bacteria in the pathogenesis of IBD has yet to be established.

Base Sequence↗