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Biomedical subjects

W M Weinstein

Publications and source records attributed to W M Weinstein.

At least 73 records · Page 4Linked to original sources

Human cryptosporidiosis in immunocompetent and immunodeficient persons. Studies of an outbreak and experimental transmission.

Infection with cryptosporidium occurred in 12 immunocompetent persons who had direct contact with the feces of infected calves during three unrelated outbreaks of calf cryptosporidiosis. Nine of the twelve subjects had diarrhea and abdominal cramps that lasted 1 to 10 days. Infections were diagnosed and monitored by detection of oocysts in feces, with a modified Sheather's flotation technique and phase-contrast microscopy. Oocysts of cryptosporidium were isolated from calves but not from other animals with which these subjects had been in contact. Oocysts of cryptosporidium were also detected during repeated examinations of feces from two immunodeficient patients with persistent cryptosporidiosis. An apparently identical infection was transmitted to calves and mice, using oocysts from infected calves and human beings. Oocysts from an immunodeficient person also produced infections in kittens, puppies, and goats. This study shows that cryptosporidium may produce a moderate self-limited illness in immunocompetent persons, which contrasts sharply with the prolonged severe diarrhea in immunocompromised patients who contract cryptosporidiosis. Calves with diarrhea should be considered a potential source of human infection, and immunocompromised persons should avoid contact with such animals.

Acquired Immunodeficiency Syndrome↗

Intestinal uptake of fatty acids and cholesterol in four animals species and man: role of unstirred water layer and bile salt micelle.

The uptake (Jd) of fatty acids (FA), fatty alcohols (Alc) and cholesterol (C) into the jejunum of rats (R, Rattus norvegicus), rabbits (RAB, Oryctolagus cuniculus), guinea pigs (GB, Cavia porcellus), and hamsters (H, Mesocricetus auratus) was assessed in vitro. Using jejunal discs the Jd of Alc was H greater than R = GP greater than RAB, the Jd of FA was H-RAB greater than R greater than GP, but the Jd of C was R greater than H greater than RAB greater than GP. The Jd of FA was quantitatively and qualitatively different when using jejunal biopsies; in man the Jd of FA into biopsies was greater than in the other animal species, but there was no difference in Jd of FA into normal human jejunal biopsies and those showing severe abnormalities in villus architecture. There are marked species differences in the passive permeability properties of the jejunum and in the effective resistance of the overlying unstirred water layer, but these differences do not explain the species variations in the uptake of cholesterol.

Adolescent↗

Dysfunction of the continent ileostomy: clinical features and bacteriology.

The pathogenesis and treatment of dysfunction of the continent ileostomy was investigated in 12 patients, five of whom had asymptomatic malabsorption and seven of whom had acute complaints. The number of anaerobic bacteria in jejunal aspirates was increased in patients with pouch malfunction (range 10(3) to 10(8)/g aspirate), but the microbiology of ileal effluent and the morphology of the ileal mucosa could not be correlated with dysfunction. Bile acid breath tests and lactose tolerance tests were not, however, reliable indicators of jejunal bacterial overgrowth. The symptoms, the malabsorption, and the number of jejunal and ileal anaerobic bacteria decreased in patients during treatment with metronidazole, implicating overgrowth of anaerobic bacterial flora in the pathogenesis of the syndrome.

Adolescent↗

The acquired immunodeficiency syndrome.

Recently, a new epidemic illness, the acquired immunodeficiency syndrome, has dramatically emerged in the United States, Europe, and Haiti. The syndrome represents an unprecedented epidemic form of immunodeficiency involving prominent defects of the T-lymphocyte arm of the immune system. Pneumocystis carinii pneumonia, other opportunistic infections, and the previously rare cancer, Kaposi's sarcoma, are the most conspicuous illnesses that have this profound state of immune compromise as their underlying basis. Two years after the onset of clinical illness the case-fatality rate may exceed 90%. A steadily growing body of epidemiologic evidence indicates an infectious (probably viral) cause of the immunodeficiency although the responsible agent(s) remains obscure. Critical issues surrounding the diagnosis, screening of blood products, treatment of complicating infections and cancers, and prognosis for immunologic recovery in affected persons are unresolved. The identification of the cause of acquired immunodeficiency syndrome and the institution of effective preventive measures require the urgent attention of the medical and scientific community worldwide.

Acquired Immunodeficiency Syndrome↗

Rubella outbreak in a prenatal clinic: management and prevention.

An obstetrician and two staff members developed rubella and exposed 56 susceptible pregnant women in a large prenatal and family planning clinic. Two women (3.6%) developed rubella at 27 and 38 weeks' gestation and delivered uneventfully. Sixteen hundred clinic and hospital employees were tested, with 79% of the total and 48 of 59 (81.4%) OB/GYN personnel showing prior infection and/or immunity (HAI titer greater than or equal to 1:8). Of those susceptible, all obstetrical and most other personnel were vaccinated and removed from high risk areas until immune. Our management of a rubella outbreak and recommendations on hospital and clinic policy to avoid potential health problems are discussed.

California↗

Comparison of kinetic constants of hexose uptake in four animal species and man.

1. The rate of in vitro uptake of glucose (gl), galactose (gal), 3-O-methyl glucose (MG), and fructose (fr) was determined using jejunal discs of hamster (ham), rat, rabbit (rab) and guinea pig (gp). 2. The maximal transport rates (Jdm) of each hexose were ham greater than rab greater than gp = rat; 3. The Michaelis constants were different for the four sugars; for gl the values were gp greater than rat greater than ham greater than rab. 4. The passive permeability coefficients (Pd) were similar for each sugar, and were greatest in ham and rat, and lowest in rat and gp. 5. The effective resistance of the intestinal unstirred water layer was lowest in ham and highest in gp and rat. 6. There were differences in the kinetic constants for gl estimated using discs and biopsies of jejunum, and the greater uptake into human biopsies than in the other species was due to the higher Jdm and Pd.

Animals↗

Artificial antigens. Antibody preparations for the localization of Lewis determinants in tissues.

High-titer antisera specific for the Lewis-a, -b, and -d determinants were obtained by the immunization of rabbits with artificial antigens prepared by coupling chemically synthesized haptens to bovine serum albumin. The use of the appropriate synthetic immunoadsorbents allowed the isolation of the desired antibodies from the sera and the elimination of cross-reactive antibody populations. The resulting refined antibodies proved highly effective for the localization by immunofluorescence staining of Lewis antigens in epithelial cells of gastric and duodenal tissue of H patients. Furthermore, the immunohistochemical procedures could be performed in conventionally prepared paraffin tissue sections. In erythrocyte Lewis-a and -b individuals, the strongest staining reactions were with the appropriate reagent. Lewis-a individuals were Lewis-d negative. Tissue from Lewis-a--b--secretors showed strong positivity in the epithelial cells of the stomach only with the Lewis-d reagent while none of the reagents showed strong reactions with the tissue from the one nonsecretor Lewis-a--b--patient. The significance of these results to the biogenesis of the Lewis antigens is discussed.

Animals↗

A therapeutic trial of 15 (R)-15-methyl prostaglandin E2 in rheumatoid arthritis patients with gastroduodenal lesions.

Thirteen patients who had rheumatoid arthritis and gastroduodenal lesion (erosions, ulcers) received 200 micrograms/d of 15(R)-15-methyl prostaglandin E2 (MPGE2) for one month in a controlled, randomized, double-blind crossover study. The patients continued their usual arthritis medications. Serial assessments were made with endoscopy and multiple antral biopsies. Seven patients improved on MPGE2 and 3 improved on placebo. Two patients worsened on MPGE2 compared with 3 on placebo. No dramatic benefit was observed after one month of therapy with MPGE2, although a moderate benefit could have been missed in a small study of this type. Our experience with this study suggests that future studies in rheumatoid arthritis should first establish the natural history of lesions in a given group of patients, that a cross-over design may actually hamper interpretation and that therapy should be more prolonged.

Adult↗

The diagnosis and classification of gastritis and duodenitis.

There are specific and nonspecific categories of gastritis and duodenitis. In each category, the mucosal pattern may be erosive or nonerosive. Specific refers to distinctive patterns of inflammation associated with defined clinical syndromes. These are rare in the stomach and include granulomatous disorders and hypertrophic gastropathies. In the duodenal bulb they include Crohn's disease and any other disorder that may affect the proximal small bowel. Endoscopy diagnoses nonspecific erosive disease of the stomach and duodenal bulb. Histology diagnoses nonspecific, nonerosive gastritis (NNG) and duodenitis (NND). The major interest in NNG and NND is in their potential as pathogenic risk factors for other disorders. Although NNG and NND may theoretically cause symptoms, provocative tests need to be devised to prove this. Confusion in the classifications of NNG and NND often arises because clinicians, radiologists, endoscopists, and pathologists use similar terms to mean different things.

Biopsy↗

Transport kinetics of D-glucose in human small intestinal mucosa: rate constants in histologically normal and abnormal mucosal biopsies.

Using D-glucose as the probe molecule, we analysed conditions which must be fulfilled in mucosal biopsy studies before the kinetic nature of the transport process can be established. Mucosal biopsies were obtained from the region of the ligament of Treitz from four healthy volunteers and from 47 patients: 29 of the 47 had histologically normal mucosa; seven had mild abnormalities; and 11 had moderate or severe ("flat") abnormalities in villus architecture. The rate of uptake of 40 mM glucose was constant only between 4 and 10 min, extrapolating through zero uptake at zero time with a constant adherent mucosal fluid volume. Incubation for shorter or longer periods was associated with over- or underestimation of the rate of uptake. Failure to use a nonabsorbable marker was also associated with overestimation of the rate of uptake. When biopsies were incubated for 6 min, a curvilinear relationship was observed between uptake rate and concentration. In biopsies with moderate and severe abnormalities, there was a marked reduction in the magnitude of the maximal transport rate and the apparent passive permeability coefficient, with little change in the magnitude of the apparent affinity constant. When human mucosal biopsies are used to study nutrient absorption, certain criteria must be fulfilled to establish valid rate constants and to make comparisons between normal and abnormal mucosa.

Adolescent↗

Campylobacter fetus infection in human subjects: association with raw milk.

Within a three week period, four cases of Campylobacter fetus infection were identified in a hospital in Los Angeles County. Three of the four patients had drunk large quantities of an identical brand of commercially available certified raw milk. Campylobacter fetus subspecies jejuni was isolated from the blood of these three patients. The fourth patient, who did not drink raw milk, had Campylobacter fetus subspecies intestinalis isolated from his blood. A telephone survey comparing cases and controls for possible risk factors associated with Campylobacter fetus infection confirmed the association with raw milk (P = 0.003). In a serologic survey, evidence suggested that Campylobacter fetus infection was associated with raw milk consumption.

Adolescent↗

Simultaneous visualization of two antigens in the same tissue section by combining immunoperoxidase with immunofluorescence techniques.

A simple method was developed whereby immunoperoxidase and immunofluorescence techniques were applied in consecutive steps to demonstrate the presence of two antigens in the same tissue section. This method was applied in three model, two antigens were shown: a) each (gastrin and pepsinogen II) inside one of two different cell types (gastrin (G) and antral peptic cells), b) each (kappa or gamma light chains) inside different cells of the same type (plasma cells); also, both (kamma and gamma light chains) inside the same cell (Reed-Sternberg cell), and c) both (pepsinogen I and II) inside the same cell (chief cell of oxyntic glands). The results could be viewed and photographed either simultaneously, when the antigens were in different cells, or sequentially, when the antigens were in the same cells.

Antigens↗

Drug sequence-dependent toxicity and small bowel mucosal injury in mice treated with low doses of 3-deazauridine and 1-beta-D-arabinofuranosylcytosine.

The toxicity to mice of combinations of 1-beta-D-arabinofuranosylcytosine and 3-deazauridine was investigated. The drugs were administered daily i.p. on Days 1 to 5, each drug at 10 mg/kg body weight; these dosages are small fractions of the dosages at which 10% of the treated animals died when either drug was administered alone on the foregoing schedule. This drug combination was severely toxic when 3-deazauridine was administered 2 to 8 hr prior to 1-beta-D-arabinofuranosylcytosine; most mice treated in this way died within 3 days of the last treatment. Histological examination showed that severe damage to the small bowel mucosa resulted from treatment with the drugs in the above, lethal sequence. In contrast, treatments with this drug combination at the same dosages were tolerated when the two agents were administered simultaneously or when 1-beta-D-arabinofuranosylcytosine preceded 3-deazauridine. Under the latter conditions, small bowel mucosal injury was much less severe. Female mice were more sensitive to the toxic treatment regimen than were male mice and were protected against the latter when either the 3-deazauridine or the 1-beta-D-arabinofuranosylcytosine component was preceded by treatment with nitrobenzylthioinosine (100 mg/kg), a potent inhibitor of nucleoside transport.

3-Deazauridine↗

Prostatic abscesses involving anaerobic bacteria.

Anaerobic bacteria have seldom been reported in prostatic abscesses. The present study concerns four cases in which the exudate was cultured with optimal microbiological techniques. Our results showed a complex aerobic-anaerobic flora in each instance, with a total of 21 isolates, including seven aerobes and 14 anaerobes. This experience has important implications concerning culture practices and empiric antimicrobial treatment for patients with prostatic abscess.

Abscess↗