RFLP and RAPD analysis of in vivo genetic interactions between strains of Helicobacter pylori.

BACKGROUND: The nature of the in vivo interactions between co-colonizing strains of Helicobacter pylori has not been well studied. This study was designed to investigate the in vivo interaction between strains of H. pylori using restriction fragment length polymorphism analysis (RFLP) and random amplified polymorphic DNA fingerprinting (RAPD) analysis. MATERIALS AND METHODS: Mice were orally inoculated with either a single strain or a mixture of strains, and killed at various time intervals up to 12 months after inoculation. RESULTS: Inoculum and recovered bacteria were identified by RAPD and RFLP. After 12 months of colonization, bacteria recovered from mice given a single strain were identical to the inoculum. In contrast, bacteria recovered from mice given a mixture of strains developed minor but consistent differences in their RAPD patterns. This variation occurred in spite of the fact that only single strains were recovered from mice given a mixture of strains. CONCLUSION: These findings support the development of genetic heterogeneity of H. pylori during long-term colonization either by genetic drift or by in vivo recombination. Such genomic modification in vivo could explain the naturally occurring heterogeneity of H. pylori.

Adenocarcinoma at ureterosigmoidostomy junction in a renal transplant recipient 15 years after conversion to ileal conduit.

In recent years, adenocarcinoma of the colon mucosa has become a recognized complication of ureterosigmoidostomy and in most cases the tumor arises at the site of ureterocolonic anastomosis. We report a case of a 29-year-old renal transplant recipient who developed two colonic carcinomas at the site of ureterosigmoidostomy 25 years after the urinary diversion and 15 years after conversion to an ileal conduit. This case emphasizes the need for a careful life-long follow-up of all patients who undergo ureterosigmoidostomy.

Effect of interferon alpha IIb on the activity of sialyltransferase in testis homogenates of adult rats.

Interferon alpha IIb was injected to adult male rats at doses ranging from 10,000 to 200,000 units. Animals were dissected at intervals of 12 h, 24 h, and 5 days. The activity of the enzyme sialyltransferase in testis homogenates was estimated. In the majority of experiments enzyme activity decreased in comparison to controls.

Frequency and activity of autorosette forming cells in Con-A activated PBL from women with hyperplasia or carcinoma of the endometrium--possible role of estrogens.

In a previous study we showed that endometrial carcinoma (EC) patients have a T cell deficiency manifested in a reduced ability to be stimulated in vitro by PHA and to produce IL-2. In an attempt to understand the mechanism responsible for this alteration we present in this paper a study on T cells characterized by the ability to form rosettes, with human erythrocytes, following Con-A activation (designated auto-rosette forming cells--ARFC). These cells are also known to manifest suppressive activity. We show that the frequency of ARFC in con-A activated peripheral blood leukocytes (PBMC) of EC patients is significantly (2-5 fold) higher than that of healthy age-matched controls or that of patients with stage--I colon or vaginal cancer. Endometrial carcinoma is known to be associated with long term exposure to estrogens unopposed by progestins. Examining the possible role of estrogens in increasing the frequency of ARFC from EC patients, we found that in vitro addition of estradiol to Con-A stimulated PBMC from healthy donors increased the frequency of ARFC to levels found in EC patients. Tamoxifen, an anti estrogen drug, reduced the frequency of the estrogen stimulated ARFC to the original low level. Our results suggest a dual role for estrogen in carcinogenesis as well as in immunomodulation.

Familial Budd-Chiari syndrome due to membranous obstruction of the right hepatic vein treated with transluminal angioplasty.

We report on a 30-yr-old man with Budd-Chiari syndrome due to right hepatic vein membranous obstruction. The patient's older brother also suffered from Budd-Chiari syndrome, and died after emergent portocaval shunt operation. To the best of our knowledge, familial occurrence of this syndrome has not been described before. The patient reported herein was successfully treated with transluminal angioplasty, and 12 months after the procedure, there are no signs of portal hypertension. Transluminal angioplasty has been used rarely for dilatation of isolated hepatic vein obstruction. This procedure should be considered as the treatment of choice for Budd-Chiari syndrome due to hepatic vein membranous obstruction.