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Y Niv

Publications and source records attributed to Y Niv.

At least 55 records · Page 3Linked to original sources
PubMed2000

Epidemiology of ulcerative colitis in Israel: a survey of Israeli kibbutz settlements.

OBJECTIVE: The incidence of ulcerative colitis ranges from 3 to 15 cases per 100,000 persons per year with a prevalence of 50-80 cases per 100,000, and the disease is 3-5 times more common among Jews. In Israel, Ashkenazi Jews have a higher incidence than Sephardi Jews, but a lower incidence than Ashkenazi Jews in the United States or Northern Europe. The aim of this study was to examine the prevalence, mean annual incidence, and clinical patterns of ulcerative colitis in a stable population of communal settlements (kibbutz). METHODS: We repeated a community-based survey in 124,400 kibbutz residents, 10 yr after our first study. This population represents 2.5% of the Jewish population of Israel. All ulcerative colitis patients were located by contacting the kibbutz clinics of the 269 kibbutz settlements (100% compliance). Data were updated to December 31st, 1997, which was designated the point prevalence date, and included information on gender, age, origin, education, profession, extent of the inflammatory process, clinical spectrum of the disease, therapy, complications of the disease, and treatment. The mean annual incidence for the 10 yr was calculated from the prevalence data. Only cases with a definite diagnosis of ulcerative colitis made in a recognized gastroenterology unit were accepted into the study. RESULTS: There were 208 confirmed cases of ulcerative colitis disease, 113 women and 95 men (female:male ratio = 1.19). The prevalence rate rose from 121.0/100,000 in 1987 to 167.2/100,000 in 1997 (p < 0.001). The prevalence rates were higher in women than men. Prevalence was highest in Israeli-born members in 1987 but in European/American-born members in 1997. The average annual incidence rate for the 10-yr period was 5.04/100,000/yr. In 1987, 146 cases of ulcerative colitis were collected. During 10 yr of surveillance 17 patients left the kibbutz, 12 died, and 62 new cases were added. The mean age at presentation of the disease was lower in 1987 than in 1997, 46.14 +/- 11.10 and 51.43 +/- 16.67 yr, respectively. Prevalence was highest in men with >16 yr and in women with 9-10 yr of education, 259.3 and 242.9/100,000, respectively. CONCLUSIONS: The prevalence of ulcerative colitis in this Israeli population increased and has reached the upper range for European and American populations. The mean annual incidence rate of ulcerative colitis is in the lower range of that reported for the Western countries.

Adolescent↗
PubMed2000

Portal hypertension induces sodium channel expression in colonocytes from the distal colon of the rat.

Cellular mechanisms for Na(+) retention in portal hypertension are undefined, but epithelial Na(+) channels (ENaC) may be involved. Under high-salt diet, ENaC are absent from distal colon of rat but can be induced by mineralocorticoids such as aldosterone. Presence of rat ENaC was determined by amiloride inhibition of (22)Na(+) uptake in surface colonocytes 7 and 14 days after partial portal vein ligation (PVL) or sham surgery. At both times, uptake inhibition was significantly increased in PVL rats. Presence of mRNA transcripts, determined by RT-PCR, demonstrated that channel alpha- and gamma-subunits were similarly expressed in both groups but that beta-subunit mRNA was increased in PVL rats. This confirms that there was induction of rat ENaC and indicates that beta-subunit has a regulatory role. Urinary Na(+) was decreased for 3 days after PVL but was not different at other times, and serum aldosterone levels were elevated at 7 days, at a time when urinary Na(+) output was similar to that of sham-operated rats. We conclude that PVL leads to induction of ENaC in rat distal colon. An increase in aldosterone levels may prevent natiuresis and is probably one of several control mechanisms involved in Na(+) retention in portal hypertension.

Aldosterone↗
PubMed1999

In colorectal carcinoma patients, serum vitamin D levels vary according to stage of the carcinoma.

BACKGROUND: Epidemiologic studies have demonstrated an inverse correlation between dietary calcium and vitamin D intake and the incidence of colorectal carcinoma. Elevated serum levels of 25-hydroxyvitamin D3 (25-OH-D3) are associated with a major reduction in the incidence of this neoplasm. The reduction in tumor size and number induced by calcium supplements in an experimental carcinogenesis model was neutralized by vitamin D3 deficiency. To the authors' knowledge, vitamin D serum levels have never been determined previously in colorectal carcinoma patients. They compared serum 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), 25-OH-D3, and parathyroid hormone (PTH) levels of colorectal carcinoma patients with those of healthy controls. METHODS: Serum 1,25(OH)2D3, 25-OH-D3, and PTH levels were determined in 84 colorectal carcinoma patients (10 with Stage I, 29 with Stage II, 25 with Stage III, and 20 with Stage IV) and 30 healthy controls, all of whom were normocalcemic and not taking calcium or vitamin D supplements. RESULTS: 25-OH-D3 serum levels were higher in cancer patients than controls, irrespective of stage. Serum 1,25(OH)2D3 decreased with advancing stage: 73 +/- 18, 48 +/- 16, 39 +/- 12, 34 +/- 13, and 75 +/- 20 pg/mL in Stages I, II, III, IV, and controls, respectively. There was a corresponding increase in serum PTH levels: 58.0 +/- 9.4, 73.7 +/- 14.4, 79.0 +/- 21.3, 100.4 +/- 30.9, and 51.2 +/- 3.9 pg/mL in Stages I, II, III, IV, and controls, respectively. Serum vitamin D metabolite levels did not correlate with gender, age, tumor localization, or histologic grade. CONCLUSIONS: An inverse correlation between serum levels of the active metabolite of vitamin D and colorectal carcinoma stage has been demonstrated for the first time, to the authors' knowledge, in colorectal carcinoma patients. Because 1,25(OH)2D3 has been shown to inhibit proliferation of colonic epithelial cells, decreased serum levels may facilitate the growth of colorectal carcinoma and influence its biologic behavior.

Aged↗
PubMed1999

[Intestinal transplantation--world experience and future perspective].

Intestinal transplantation, which until recently has been considered an experimental procedure, is now undergoing considerable change and becoming a standard treatment for patient with intestinal failure. The major improvement in results is due to the introduction of new immunosuppressive agents that have led to significant reduction in acute rejection. Nevertheless, reduction in severe infectious complications, which are the main cause of mortality after transplant, as well as improved techniques for early diagnosis of rejection are needed before intestinal transplantation can be widely used. We describe our experience in post-transplant follow-up of a woman, aged 32-years, who had undergone intestinal transplantation for short bowel syndrome after extensive bowel resection.

Adult↗
PubMed1999

Seroprevalence of Helicobacter pylori and length of stay in a nursing home.

BACKGROUND: Helicobacter pylori infection appears to be contracted mainly in childhood, and it is associated with disadvantaged socioeconomic conditions, overcrowding, and living in institutions. In this study we determined the seroprevalence of H. pylori among elderly patients (age > or = 70 years) admitted to a major medical center in Israel, and studied the relationship between seroprevalence of H. pylori and the duration of stay in a nursing home prior to the admission. PATIENTS AND METHODS: Whole blood from 182 consecutive patients hospitalized at the Rabin Medical Center was tested for the presence of anti-H. pylori IgG using Helisal Rapid Blood Test kit (Cortecs Diagnostics). Multivariate logistic regression analysis was used to study the relation between H. pylori seropositivity and possible predictive factors such as age, gender and duration of stay in a nursing home. RESULTS: Of the 182 patients included in the study, 80 (44%) were living in nursing homes (NH) and 102 (56%) were living in their own homes (H) prior to admission. Subjects that stayed in nursing homes for more than 15 months were significantly more likely to be seropositive than subjects with a shorter duration of stay (84% and 63% respectively, p = 0.03). Using a multivariate logistic regression analysis on both the NH group and the whole group, seropositivity was found to be significantly associated with duration of stay in a nursing home (p = 0.03 and p = 0.01 respectively). Seropositivity was not associated with age in either group. CONCLUSIONS: Living in a nursing home is associated with increased risk for H. pylori infection in the elderly. There is a strong correlation between the duration of stay in a nursing home and the prevalence of H. pylori infection.

Age Factors↗
PubMed1999

Epidemiology of Crohn's disease in Israel: a survey of Israeli kibbutz settlements.

OBJECTIVE: The prevalence of Crohn's disease ranges from 10 to 70 cases per 100,000 population, and is 3-8 times more common among Jews. However, this excess risk is not evident in the Jewish population of Israel. Recently we have described a significant increase in the prevalence and incidence of Crohn's disease in the south of Israel. The aim of this study was to confirm this trend in a stable population found in communal (kibbutz) settlements. METHODS: We repeated a community-based survey in 124,400 kibbutz residents, 10 yr after our first study. This population represents 5% of the Jewish population of Israel. All Crohn's disease patients were located by contacting the kibbutz clinics of the 269 kibbutz settlements (100% compliance). Data was updated to December 31st, 1997, which was designated the point prevalence date, and included information on gender, age, origin, education, profession, extent of the inflammatory process, clinical spectrum of the disease, therapy, complications of the disease, and treatment. The average annual incidence for the 10 yr was calculated from the prevalence data. Only cases with a definite diagnosis of Crohn's disease made in a recognized gastroenterology unit were accepted into the study. RESULTS: There were 81 confirmed cases of Crohn's disease and the prevalence rate rose from 25.5/100,000 in 1987 to 65.1/100,000 in 1997 (p < 0.001). The mean annual incidence rate for this period (1987-1997) is 5.0/100,000/yr. Prevalence rates were higher in women than men, and in those born in Israel or Europe/America than in Asia/Africa. The mean age at presentation of the disease was lower in 1997 than in 1987, 37.4 +/- 17.0 and 45.0 +/- 17.0 yr, respectively (p = 0.041). Prevalence was highest in men with > 16 yr of education, and in women with 11-12 yr education, 119.7 and 100.3/100,000, respectively. CONCLUSIONS: During the decade 1987-1997, the prevalence of Crohn's disease has increased in Israel and is approaching the rates in Europe and America.

Adolescent↗
PubMed1999

Small bowel transplantation--a clinical review.

The results of small bowel transplantation improved in the last 5 yr because of the development of new immunomodulating drugs and surgical techniques, as well as better candidate selection. We still need much experience until this procedure will be in routine use for terminal intestinal insufficiency.

Adjuvants, Immunologic↗
PubMed1998

A comparison of new rapid urease tests for detection of Helicobacter pylori: test characteristics and factors affecting positivity and time to positivity.

We assessed two new rapid urease tests, the Helicobacter Urease Test (HUT, Astra, Sweden) and the Polish test, for accuracy, reaction time, and the effect of biopsy site and bacterial density on test characteristics and time to positivity. A prospective study was conducted in two groups of patients: 64 consecutive patients undergoing upper endoscopy for dyspepsia and 61 consecutive patients with duodenal ulcer on upper endoscopy. In the first group, test accuracy, time to positivity, and possible associations with biopsy site and bacterial density were assessed between the tests. In the second group, the two new tests were compared with the CLOtest for time to positivity and effect of bacterial density on test outcome. The Polish and HUT test had similar specificities (97%), but the Polish test was more sensitive (90.3% vs. 80.7%). The Polish test was positive within 10 minutes in 55% of the positive patients compared with 10% for the HUT test. There was no association between bacterial density (by histologic count) and reaction time in either test or in the CLOtest in the second group. The Polish test was more accurate and had a quicker time interval to positivity than the HUT. There was no significant association between bacterial density and reaction time in any of the urease tests assessed, and the biopsy site did not affect test accuracy in the HUT test.

Adult↗
PubMed1998

Comparison of two bowel preparations for colonoscopy: sodium picosulphate with magnesium citrate versus sulphate-free polyethylene glycol lavage solution.

OBJECTIVES: Adequate preparation of the bowel is essential for accurate colonoscopic examination. We compared colonic preparation with sodium picosulphate plus magnesium citrate (SPS-Mg) with sulphate-free polyethylene glycol electrolyte lavage (PEG-EL) solution before colonoscopy, for quality of bowel cleansing, patient discomfort, and side effects. METHODS: Sixty-eight consecutive patients were randomly assigned to receive either 3 sachets of SPS-Mg (16.5 g each) (n = 39) or 3 L of PEG-EL (n = 29) on the day before colonoscopy. Shortly before the procedure each patient was interviewed to determine the degree of discomfort (1 = none or mild, 2 = moderate, 3 = severe) and side effects. The quality of bowel cleansing was graded by a gastroenterologist who was unaware of the method of preparation (from 1 = poor to 4 = excellent). RESULTS: Of the 29 PEG-EL patients, four (14%) did not complete the preparation because of side effects. The degree of discomfort was significantly greater with PEG-EL (mean score, 2.3 +/- 0.7) than with SPS-Mg (mean score, 1.4 +/- 0.5; p < 0.01). Nausea and vomiting were significantly more common in the PEG-EL group (38% vs 13%; p < 0.05). Using intention-to-treat analysis, bowel cleansing proved to be significantly better with SPS-Mg than with PEG-EL (mean score +/- SD, 3.05 +/- 0.9 and 2.57 +/- 1.0, respectively; p = 0.036). CONCLUSIONS: Colonic preparation with SPS-Mg is better tolerated, associated with significantly fewer side effects, and results in higher quality bowel cleansing than preparation with PEG-EL.

Adult↗
PubMed1997

Characterization of sodium and chloride conductances in preneoplastic and neoplastic murine colonocytes.

Glucocorticoids, such as dexamethasone, induce amiloride-sensitive Na+ conductances in rat distal colon epithelium. The activity of these conductances diminishes from the surface to the base of the crypt whereas cAMP-stimulated Cl- secretion decreases from the crypt base to the surface. These gradients are likely to be perturbed during carcinogenesis. We therefore determined the magnitude of Na+ and Cl- conductances in colonocytes isolated from normal and carcinogen-treated rats. Colon carcinogenesis was induced by injection of dimethylhydrazine (DMH) (18 mg/kg) for 5 weeks. Before sacrifice animals were treated for 3 days with dexamethasone. Colonocyte populations from the surface to the crypt base (C1-C5) were harvested from the distal colon by a Ca2+-chelating procedure. The activity of Na+ conductances was determined by uptake of 22Na+ by surface and crypt colonocyte populations and by membrane vesicles in the presence and absence of 10 microM amiloride. In control rats Na+ conductance was highest in surface colonocytes and absent in the crypt base. As early as 2 weeks after initiation of DMH treatment amiloride-inhibited Na+ uptake was virtually absent in the upper crypt. Transcriptional assessment of the alpha-, beta- and gamma-subunits that constitute the epithelial Na+ channel revealed that DMH treatment reduces the expression of beta-subunit mRNA. We then examined 36Cl- efflux from isolated colonocytes of normal and carcinogen-treated rats in response to forskolin (0.01 mM). Forskolin induced a marked rise in cAMP in lower crypt cells concomitant with a significant stimulation of 36Cl- efflux. Intracellular cAMP increased in upper crypt cells in response to forskolin without an increase in 36Cl- efflux. By contrast, upper crypt colonocytes from DMH-treated rats showed forskolin-stimulated efflux beginning 4 weeks after initiation of treatment. We conclude that induction of Na+ conductances by glucocorticoids is inhibited during the early stages of chemical carcinogenesis due to lack of induction of the beta-subunit of the channel. By contrast, Cl- transport is stimulated both in surface and lower crypt cell compartments during different stages of chemical carcinogenesis.

Amiloride↗