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Biomedical subjects

J Zimmerman

Publications and source records attributed to J Zimmerman.

At least 19 recordsLinked to original sources
PubMed1992

Drug interactions in intestinal transport of folic acid and methotrexate. Further evidence for the heterogeneity of folate transport in the human small intestine.

The effect of sulfasalazine and olsalazine on the transport of [3H]folic acid and of [3H]methotrexate (MTX) was investigated in organ-cultured endoscopic biopsy specimens of small intestinal mucosa from normal subjects. Biopsy specimens obtained from patients undergoing routine diagnostic upper gastrointestinal endoscopy were organ-cultured at pH 5.5 and the effect of these two drugs on the initial rate of uptake of the two folates was determined. Both drugs inhibited the transport of [3H]folic acid with similar Ki values (1.38 and 1.32 mM for sulfasalazine and olsalazine, respectively). However, the uptake of [3H]MTX was only partially inhibited by sulfasalazine and was unaffected by olsalazine. Sulfasalazine inhibited 26.2% of the total flux of MTX, in close agreement with the fraction of MTX flux that has been shown previously to be inhibited by folic acid. These data corroborate previous findings of heterogeneity of transport of MTX in the mucosa of the human small intestine.

Aminosalicylic Acids↗
PubMed1992

Methotrexate transport in the human intestine. Evidence for heterogeneity.

The transport of methotrexate (MTX) was investigated in organ-cultured endoscopic biopsy specimens of intestinal mucosa from normal subjects. In biopsy specimens from the proximal small intestine incubated with [3H]MTX (0.1 microM) for 2 hr at pH 5.5, [3H]MTX accumulated in the intracellular fluid to a concentration 3.5-fold higher than that of the medium, but at pH 6.5 and 7.5, the concentration was the same as that of the medium. In biopsy specimens from the cecum incubated under similar conditions, no accumulation against a concentration gradient was found. However, the accumulation of MTX was significantly higher at pH 5.5 than at 7.5. At [MTX] = 0.1 microM, the initial rate of MTX transport in the small intestine was significantly affected by medium pH and was optimal at pH 5.5. The relationship between the initial rate of uptake and medium [H+] was hyperbolic, suggestive of saturability with respect to [H+] with a Km of 132.2 nm [H+], corresponding to a medium pH of 6.88. At medium [MTX] = 10 microM, this effect was abolished. At pH 5.5, the relationship between the initial rate of uptake and medium [MTX] was sigmoidal, suggestive of a positive cooperativity, with napp of 1.8. [MTX] at 0.5 Vmax was 20.37 microM. Folic acid inhibited 37% of MTX flux. At pH 7.5, the relationship between the initial rate of uptake of MTX and medium [MTX] was linear. These data indicate the presence of a proton-dependent active transport of MTX in the human proximal small intestine, which is partially shared with folic acid.

Biological Transport↗
PubMed1992

Decreased levels of soluble amyloid beta-protein precursor in cerebrospinal fluid of live Alzheimer disease patients.

The amyloid beta-protein is deposited in senile plaques and the cerebrovasculature in Alzheimer disease (AD). Since it is derived from proteolytic processing of its parent protein, the amyloid beta-protein precursor (APP), we investigated whether levels of the secreted forms of APP are altered in cerebrospinal fluid (CSF) of AD patients. Quantitative immunoblotting studies with the anti-APP monoclonal antibody P2-1 revealed that probable AD patients had markedly lower CSF APP levels than did demented non-Alzheimer-type patients and healthy control subjects. Using antibody P2-1 in an enzyme-linked immunosorbent assay, we measured CSF levels of APP in a larger population consisting of 13 patients diagnosed with probable AD, 18 patients diagnosed with dementia (non-Alzheimer type), and 16 nondemented, healthy controls. Mean CSF levels of APP were approximately 3.5-fold lower in the live patients diagnosed with probable AD compared to the demented non-Alzheimer-type controls or the nondemented, healthy individuals. These findings suggest that abnormal metabolism of APP is reflected in the extracellular fluids of the central nervous system and that CSF levels of soluble APP provide a useful biochemical marker to assist in the clinical diagnosis of AD.

Alzheimer Disease↗
PubMed1992

Families with adolescents: escaping problem lifestyles.

Using the concepts of "restraints" and reciprocal patterns, a specific approach for understanding and working with families of adolescents is offered. The organizing idea is the "restraint" that revolves around a difficulty both parents and youngsters have in making a distinction between what parents want for their youngsters and what the young person might want. This difficulty may come from the parents' ideas and beliefs about parenting and from their own growing-up experience, from the adolescent's "not completely storied" lives, and/or from societal discourse about adolescence. Restraint of ideas can be constructed as reciprocal patterns and located in dominant narratives that families may have about themselves. A restorying process allows families to separate from the problem pattern and focus on the youngsters' willingness to have ideas for themselves.

Adolescent↗
PubMed1992

Seasonal fluctuations in acute upper gastrointestinal bleeding: lack of effect of nonsteroidal anti-inflammatory drugs.

The seasonal pattern of community-based acute bleeding from the upper gastrointestinal (UGI) tract was studied prospectively in 1988-1991. Out of 3343 emergency admissions to the Departments of General Surgery, 321 (9.6%) were due to acute UGI bleeding. There was a significant monthly variation in the total number of admissions, as well as in the number of admissions due to acute UGI bleeding (p < 0.0001). However, there was no correlation between the two. Significant seasonal fluctuations were noted both in the absolute number of admissions due to acute UGI bleeding and in the percentage of UGI bleeding admissions of the total number of admissions to the Departments of General Surgery (p = 0.0002). During summer (July through September), the incidence declined significantly to a nadir of 5.5% of total number of admissions in July. The seasonal fluctuation correlated closely with the incidence of duodenal ulcer, but not with that of gastric ulcer. The seasonal pattern was consistent both in patients who had used aspirin or other nonsteroidal anti-inflammatory drugs as well as in those who had not.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1992

Sigmoid volvulus presenting as chronic secretory diarrhea responsive to octreotide.

Secretory diarrhea can be seen in a variety of pathologic states; however, intermittent colonic obstruction usually is not considered as a possible cause. We report a 68-yr-old patient with chronic secretory diarrhea and hypokalemia due to intermittent sigmoid volvulus. Because the volvulus was not originally diagnosed, the patient was treated with the long-acting somatostatin analogue octreotide for 1 yr, with marked clinical improvement. Surgical resection of the redundant sigmoid responsible for the volvulus resulted in prompt and complete resolution of all signs and symptoms. Detailed macroscopic and microscopic examination of the resected specimen was normal. The patient continues to be asymptomatic 12 months after surgery. Increased colonic fluid and electrolyte secretion was caused by intermittent sigmoid volvulus and resulted in chronic secretory diarrhea.

Aged↗
PubMed1991

Measurement of tissue lithium concentration by lithium magnetic resonance spectroscopy in patients with bipolar disorder.

Measurements of the lithium concentration in the occipital pole of the head and calf muscle of nine patients with bipolar disorder in remission were performed using in vivo lithium-7 nuclear magnetic resonance spectroscopy (7Li NMR). 7Li NMR measurements were performed on a 1-m-bore, 1.85-T, superconducting magnet supplemented with a multinuclear spectrometer, using 11.5-cm-diameter surface coils. The average lithium concentration in the occipital pole was 0.36 +/- 0.10 mEq/L, whereas in the muscle it was 0.50 +/- 0.17 mEq/L, both lower than the average serum lithium concentration (0.79 +/- 0.23 mEq/L). The average brain/serum lithium concentration ratio was 0.47 +/- 0.12 whereas the average muscle/serum lithium concentration ratio was 0.66 +/- 0.20. There was a positive correlation between the brain versus serum and brain versus muscle lithium concentrations. The hypothesis is advanced that the minimal effective concentration of brain lithium concentration for maintenance treatment of bipolar disorder is around 0.2-0.3 mEq/L.

Adult↗
PubMed1991

Prevalence of inflammatory bowel disease in family members of Jewish Crohn's disease patients in Israel.

A familial study of 189 Jewish Crohn's disease patients was conducted in order to evaluate the risk for inflammatory bowel disease (IBD) in relatives of the patients and to try to understand better the genetic component in the etiology of the disease among Jews. One hundred fifty-seven patients filled out questionnaires that were verified by personal interviews. In 10 families (6.6%), a first-degree relative of the propositus was found to have IBD, seven Crohn's disease and three ulcerative colitis. Among first-degree relatives, siblings were more frequently affected: of 400, five had Crohn's disease and one ulcerative colitis. Among 304 parents, two had Crohn's disease and two ulcerative colitis, while none of the propositi's children had IBD. The prevalence of first-degree relatives with Crohn's disease was similar in the 98 and 45 families of Ashkenazi and non-Ashkenazi origin: 5.1% and 4.4%, respectively. The risk for siblings of the probands to be affected were also similar in the two groups: 1.5% and 1.8%; while parents of the probands were affected only in the group of Ashkenazi Jews.

Adolescent↗
PubMed1991

Comparison of the rates of adverse drug reactions. Ionic contrast agents, ionic agents combined with steroids, and nonionic agents.

The influence of ionic agents alone, of diatrizoate plus two oral doses of methylprednisolone premedication, and of a nonionic agent (iohexol) upon the frequency and severity of adverse drug reactions (ADRs) was compared in ten hospitals during three separate time periods from 1985 to 1989. Nonionic agents were found to reduce significantly total ADRs; 52 of 8857 patients receiving nonionic agents experienced reactions, versus 263 of 6006 patients for ionics (P less than .0001). The frequency of reactions classed as mild (2.9% for ionic agents versus 0.476 for nonionic agents: P less than .001), moderate (1.2% versus 0.1%; P less than .001), or severe (0.37% versus 0.01%; P less than .001), also favored nonionic agents. Steroid premedication provided some protection, but iohexol was significantly better with respect to mild reactions (2.9% versus 0.4%, P less than .001), moderate reactions (0.9% versus 0.1%, P less than .01), and severe reactions (0.25% versus 0.01%, P less than .01). The contrast medium was the greatest risk factor for adverse reaction (odds ratio 7.3), while prior contrast reaction (odds ratio 6.25), and hay fever (odds ratio 2.3) were found to be significant independent risks. We conclude that nonionic agents are safer for intravenous use than ionic agents given alone or with corticosteroid premedication.

Diatrizoate Meglumine↗
PubMed1991

The beginning development of a model for joint research between a hospital social work department and a school of social work.

Efforts of agencies and schools of social work to encourage goals of research and professional writing among their staff and faculty have brought uneven results. A medical center and a graduate school of social work are in the process of implementing a joint research model which encourages practice based research and publication. This paper describes the beginning structures of the model and the questions addressed in the formative process.

Humans↗
PubMed1991

Crohn's colitis complicated by superimposed invasive amebic colitis.

The clinical characteristics and endoscopic appearance of inflammatory bowel disease (IBD) may be very similar to those of amebic colitis. Physicians, especially in areas in which amebiasis is endemic, are familiar with this difficulty. Moreover, in individual cases, it may even be impossible to distinguish between the two conditions, since stool specimens, bowel biopsies, and serological studies may be negative for Entamoeba histolytica, even in the presence of invasive amebic colitis. Invasive amebiasis may rarely be superimposed on IBD, which further complicates the issue. We report here a young patient with a 7-yr history of Crohn's colitis proven histologically who developed invasive amebic colitis during steroid and 6-mercaptopurine treatment for active disease. Stool specimens, mucosal biopsies, and serological studies were negative for E. histolytica, and the diagnosis was established on pathological examination of a surgically resected bowel. Anti-amebic therapy should be considered in endemic areas in cases of persistent IBD.

Adult↗
PubMed1991

Chronic diuretic therapy with moderate doses of triamterene is not associated with folate deficiency.

The diuretic drug triamterene has previously been shown to be a competitive inhibitor of folate absorption in the rat intestine (J Lab Clin Med 1986;108:272-6). We therefore investigated whether human subjects who are taking the drug on a long-term basis are at increased risk of folate deficiency. In each of two free-living populations, a study was performed to compare the folate status of triamterene users with those not taking the drug. The first population consisted of 272 elderly individuals not living in institutions who were participants in a nutrition status survey and who were taking a variety of antihypertensive medications; 32 of these individuals were daily users of triamterene. The hemoglobin concentration, red blood cell (RBC) count, and mean corpuscular volume (MCV) values were not significantly different between the triamterene users and nonusers. The female triamterene users had a slightly higher serum folate level than the female nonusers (p less than 0.04); a similar pattern was observed among the men, although the difference was not statistically significant. The second population consisted of 27 individuals attending a hypertension clinic; 18 subjects were taking 50 to 150 mg of triamterene per day and nine were taking antihypertensive drugs other than triamterene. The hemoglobin concentration, RBC count, MCV, serum folate values, and RBC folate values were found to not differ significantly between the triamterene users and the hypertensive controls (p greater than 0.05). These data suggest that chronic triamterene administration in individuals not living in institutions, at the doses examined in this study, is not associated with indications of folate deficiency.

Aged↗
PubMed1990

Folic acid transport in organ-cultured mucosa of human intestine. Evidence for distinct carriers.

The transport of folic acid was investigated in organ-cultured endoscopic biopsy specimens of intestinal mucosa from normal subjects. In the proximal small intestine at pH 5.5 and 6.5, [3H]folic acid accumulated to concentrations 2.64- and 2.17-fold higher than those of the medium, respectively, but at pH 7.5 the concentration was same as that of the medium. Saturability of initial rates of uptake was demonstrable with respect to luminal concentrations of [H+] and folic acid. Two proton-dependent transport mechanisms were evident: (a) a carrier with a low affinity for H+ and a low capacity for folic acid, and (b) a high-affinity, high-capacity carrier (Km, 635 and 54.6 nmol/L [H+]; Vmax, 0.066 and 2.583 pmol folic acid/microL intracellular water per 10 minutes, respectively). Kinetic studies of folic acid uptake at pH 5.5 and 7.5 revealed a difference in Km for folic acid (15.76 and 34.38 mumol/L, respectively) with no change in Vmax. In the colon, folic acid did not accumulate against a concentration gradient, and the initial rate of uptake was not affected by luminal pH. The accumulation of folic acid in colonic mucosa was significantly higher at pH 5.5 than at 7.5 and showed significant regional variation, with optimal uptake in the sigmoid colon. Methotrexate inhibited folic acid uptake competitively both in the proximal small intestine and in the cecum (inhibition constant 6.9 and 54 mumol/L, respectively, at pH 5.5). These data indicate the presence of a proton-dependent, active transport of folic acid in the proximal small intestine at pH 5.0-6.5. At pH 7.5 and in the mucosa of the colon, uptake of folic acid proceeds by facilitated diffusion through a low-affinity carrier.

Biological Transport, Active↗