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Biomedical subjects

B E Walker

Publications and source records attributed to B E Walker.

At least 55 records · Page 3Linked to original sources
PubMed1988

Vaginal tumors in mice from methylcholanthrene and prenatal exposure to diethylstilbestrol.

To test the hypothesis that mice exposed prenatally to diethylstilbestrol (DES) develop adenocarcinomas due to sensitivity of vaginal and cervical adenosis to carcinogens, sponges impregnated with methylcholanthrene (MCA) were lodged against the cervix and vaginal fornices of 6-month-old strain CD-1 mice exposed prenatally to DES. Only squamous cell carcinomas developed in these mice, but at a significantly higher rate than in MCA-treated mice not exposed prenatally to DES. An adenosquamous carcinoma and a precursor of adenocarcinoma developed in DES-exposed mice with control sponges.

Adenocarcinoma↗
PubMed1988

Leucocyte zinc in non-Hodgkin's lymphoma and Hodgkin's disease.

Zinc status and the effect of zinc supplementation were assessed in groups of patients with non-Hodgkin's lymphoma and Hodgkin's disease; patients were either untreated or in remission. In the patients in remission, plasma zinc was normal; and whereas 30% of untreated patients had low plasma zinc, the group as a whole did not differ from normal. For mononuclear cell zinc, the range of values in the disease group was far wider than in controls, but there was no significant difference between the means of the groups. Granulocyte zinc was significantly lower in both the groups of patients in remission from non-Hodgkin's lymphoma and Hodgkin's disease compared with the control group. Significant increases were found in the plasma copper, ceruloplasmin, and the copper-to-zinc ratio in several of the patient groups. Plasma zinc increased by 23% with zinc supplementation (50 mg elemental Zn/day), but there was no effect on mononuclear cell or granulocyte zinc. Apart from granulocyte zinc, there is little evidence of zinc deficiency in non-Hodgkin's lymphoma or Hodgkin's disease. However, the presence of depleted granulocyte zinc levels could modify the immune function of this cell population.

Adult↗
PubMed1987

Ovariectomy of adult mice exposed prenatally to diethylstilbestrol.

Mice exposed prenatally to diethylstilbestrol (DES) were ovariectomized at 5-10 weeks of age, or at 15 months of age. They were maintained to old age and studied for incidence of DES-related pathologic changes. Uterine metaplasia and adenomyosis were not seen after early ovariectomy, but adenomyosis persisted after late ovariectomy. No adenocarcinomas of the genital tract were found in 30 mice ovariectomized early, or in 18 mice ovariectomized at 15 months of age. This result is significantly different from the 14% frequency of genital tract adenocarcinomas reported previously in non-ovariectomized mice of this strain exposed prenatally to DES.

Age Factors↗
PubMed1987

Plasma and leucocyte zinc concentrations and their response to zinc supplementation in an elderly population.

Plasma, mononuclear cell and granulocyte zinc were assessed in a group of 15 institutionalised elderly female patients, and the effect of different levels of zinc supplements (50, 100, 150 mg elemental zinc/day) on these parameters was measured. Plasma but not cellular zinc was lower in the elderly compared with a young control group, but a diminished serum albumin may explain the plasma results. Plasma zinc increased with supplementation, but only when the daily intake was 100 or 150 mg/day; the greatest response was with the higher dose. Mononuclear cell zinc did not respond to zinc supplements. There was a decrease in granulocyte zinc at all levels of zinc supplements, the greatest decrease being found with the highest dose (150 mg/day). The decrease in granulocyte zinc at high intakes may have implications in phagocytosis and chemotaxis.

Aged↗
PubMed1986

Nutrition and cellular immunity in hospital patients.

1. The interrelations between nutritional and cellular immune function measurements were studied in seventy patients suffering from various degrees of malnutrition. They included patients with liver disease, inflammatory bowel disease, neoplastic disease, neurological patients, post-operative surgical patients and patients with respiratory problems. 2. Nutritional measurements included: anthropometry, serum proteins, various vitamins and trace elements, and a prognostic nutritional index (PNI) was calculated. 3. Immunological measurements included: (1) natural killer (NK) cell activity, (2) antibody-dependent cellular cytotoxicity (ADCC), (3) lymphocyte proliferation in response to the mitogens concanavalin A (Con A), phytohaemagglutinin (PHA) and pokeweed mitogen (PWM) in both AB and autologous serum. 4. There was no association between anthropometric measurements and tests of immune function. 5. The lymphocyte proliferation in response to mitogenic stimulation in the malnourished patients was depressed in autologous serum compared with the response of the same lymphocytes in pooled AB serum. The lymphocyte proliferation in response to Con A correlated with transferrin in autologous serum (r 0.46, n 49, P less than 0.01) and to a lesser extent in AB serum (r 0.33, n 51, P less than 0.05). There was a difference in the Con A-stimulated tritiated-thymidine uptake between patients with low and normal serum zinc levels (P less than 0.05) for cultures performed in autologous serum, but not AB serum. 6. There was a significant correlation between NK cell activity and vitamin C (r 0.43, n 60, P less than 0.01). There was no relation between nutritional measurements and ADCC or the lymphocyte response to stimulation with PHA or PWM. 7. The results suggest that the severity of overall malnutrition does not influence several different aspects of the cellular immune response. However, the results do suggest that certain individual nutrients, particularly vitamin C and Zn, do influence the immunoreactivity of different lymphocyte subpopulations.

Hospitalization↗
PubMed1986

Essential element nutritional status in cystic fibrosis.

Serum calcium, magnesium, iron, copper and zinc were measured in 117 patients with cystic fibrosis. Apart from serum iron levels, all the other essential element levels were well maintained and there was no evidence of a need for supplementation. Serum iron was frequently low and the need for iron supplements must be considered after further investigation. The subjects studied covered a wide age range, had widely varying fat malabsorption and clinical grading, and also varying degrees of pulmonary involvement. We found no evidence that any of these parameters directly influenced essential element status as assessed by serum levels.

Adolescent↗
PubMed1984

Tumors of female offspring of mice exposed prenatally to diethylstilbestrol.

Strain CD-1 female mice exposed prenatally to diethylstilbestrol (DES) (CAS: 56-53-1; alpha,alpha'-diethyl-4,4'-stilbenediol) were mated to unexposed males. Female offspring of these matings were raised to the stage of terminal illness. They were never exposed to DES and so have been referred to as "DES-lineage mice." Ten uterine adenocarcinomas and 5 ovarian cystadenocarcinomas were found in 40 DES-lineage mice. These findings were significantly different from the absence of such tumors in 24 "vehicle-lineage" mice whose mothers had received injections only of oil and alcohol. The types of tumors that commonly occur spontaneously in the CD-1 strain appeared with comparable frequency in the 2 groups of mice. The DES-lineage mice did not show the increased frequency of adenomyosis and squamous metaplasia of the uterus, nor the reduced frequency of corpora lutea seen in mice exposed prenatally to DES.

Adenocarcinoma↗
PubMed1983

Complications of pregnancy in mice exposed prenatally to DES.

Women exposed prenatally to diethylstilbestrol (DES) develop a variety of reproductive tract anomalies. Most of these anomalies have been replicated in strain CD-1 mice after similar DES exposure. Recently, impaired reproductive performance in DES-exposed women has been reported. To see whether the mouse model also replicates this defect, a study of reproduction was performed. Pregnant CD-1 mice were injected with DES and their female offspring were raised to breeding age. The latter were then exposed continuously to untreated males for a maximum of 4 months. Among 74 mated mice, 34 became pregnant and 11 of these pregnancies ended in abortion or stillbirth. Other anomalies encountered were: two fetuses with compressed heads, one of which seemed blocked from delivery by a vaginal adenocarcinoma; two uterine tumors, one of which was a teratocarcinoma; two teratomas located in uterine lumina; and two uteri containing placentas without embryos. Since the frequency of successful pregnancies in the DES-exposed mice was reduced below control levels to a degree similar to that reported for DES-exposed women, the validity of the mouse model has been confirmed for this characteristic.

Animals↗
PubMed1983

Nutritional and immunological assessment of patients with anorexia nervosa.

The nutritional and immunological status of patients with anorexia nervosa was assessed. Anthropometric measurements were found to be lowered as were the serum levels of zinc (p<0.01), copper (p<0.01) and ceruloplasmin (p<0.05) in comparison with the control group. However the serum levels of albumin, pre-albumin, transferrin and retinol binding protein, vitamins A and D and leucocyte vitamin C were generally found to be within normal limits. Lymphocyte transformation was measured in response to stimulation with the mitogens Con A, PHA and PWM. Responses were normal in all patients with the exception of one who showed a depressed response to Con A. Natural killer cell activity was measured against the target cell line K562 and was not found to differ significantly from controls. It is suggested that the relatively normal protein and vitamin status is responsible for maintaining the apparently normal cellular immune function in patients with anorexia nervosa.

Journal Article↗
PubMed1983

Zinc, vitamin A and prostatic cancer.

The serum zinc, vitamin A, albumin, copper and retinoid-binding protein content was measured in 27 patients with benign prostatic hyperplasia and 19 patients with carcinoma of the prostate. A significantly lower (P = less than 0.05) level of serum zinc was found in the cancer group as well as a significant zinc/vitamin A correlation (P = less than 0.05). The possible significance of this in relation to the pathogenesis of carcinoma of the prostate is discussed.

Aged↗
PubMed1983

Uterine tumors in old female mice exposed prenatally to diethylstilbestrol.

Pregnant strain CD-1 mice were treated with diethylstilbestrol (DES) or vehicle. Their female offspring were raised to old age and autopsied when terminally ill. Squamous metaplasia and adenomyosis were more common in uteri of these old mice exposed prenatally to DES than in control mice. Tumors of the uterine horns were seen in 17 of 143 DES-exposed mice and in 3 of 64 control mice. The controls had only leiomyomas, whereas 14 of the DES-exposed mice had adenocarcinomas. There were 5 cervical adenocarcinomas and 1 vaginal adenocarcinoma among treated mice but none in the control mice. Thus the effects of prenatal exposure to DES interacted with the effects of aging to produce a relatively high frequency of uterine adenocarcinoma.

Adenocarcinoma↗
PubMed1979

Serum-calcium.

Explore the source record for details and available documents.

Calcium↗
PubMed1979

The effect of wheat bran and pectin on paracetamol absorption in the rat.

1. The absorption of an oral dose of paracetamol was measured in rats given either a basal fibre-free diet, or the basal diet with either pectin or bran added. 2. Urinary excretion of the oral dose was significantly greater during the first 8 h in the pectin-fed rats compared with those on basal diet, though cumulative excretion after 72 h was the same. 3. Free paracetamol levels in the plasma were significantly higher in the pectin-fed rats compared with those on basal diet at 30, 60, 90 and 120 min after the oral dose. 4. The plasma half-life of intravenously-injected paracetamol was shorter in the pectin-fed rats than in those on basal diet alone, but the antipyrine half-lives were not significantly different. 5. Pectin feeding had no effect on either the apparent volume of distribution of paracetamol and antipyrine, or on the rate of gastric empyting. 6. Perfusion of the whole length of the small bowel showed a significantly greater capacity for paracetamol absorption in the pectin-fed rats. 7. Bran had no effect on paracetamol absorption. 8. It was concluded that dietary fibre intake affects drug absorption and that the effect varies with the type of fibre. Unexpectedly pectin accelerates rather than retards absorption of paracetamol, though the mechansim of this effect is unknown.

Acetaminophen↗
PubMed1979

The gastrointestinal absorption of paracetamol in the rat.

The absorption of [3H]paracetamol by rat small intestine, colon and stomach was studied in vivo and in vitro. Small intestinal in vivo studies, using a wide range of drug concentrations, showed that absorption was efficient and uniform throughout the small bowel, no site showing preferential absorption. Double reciprocal and direct plots indicated first order kinetics. The pattern was not observed when uptake was occurring from high concentrations of paracetamol in suspension. Gastric and colonic in vivo studies showed that there was appreciable absorption of [3H]paracetamol from these sites. In vitro studies using everted intestinal sacs showed no effect on paracetamol transfer when the incubation temperature was lowered to 10 degrees C or when iodoacetate (5 X 10(-2)M) and 2.4 dinitrophenol (5 X 10(-4)M) was added to the incubation medium. There was, however, a significant reduction in transfer of paracetamol against a concentration gradient of 10:1 applied across the mucosa. These data suggest that the uptake of paracetamol is by a passive transport process and confirm the efficiency of paracetamol absorption observed indirectly by others.

Acetaminophen↗
PubMed1979

Adjusted calcium conflict resolved? Differing effects on plasma total calcium of changes in plasma albumin after venous stasis or myocardial infarction.

Others have challenged the concept of adjusting total plasma calcium for albumin concentration on the grounds that after the application of a tourniquet the increase in calcium for a given increase in albumin differs significantly between normal individuals. We have confirmed this finding. In contrast, we have found that after myocardial infarction the fall in calcium for a given fall in albumin does not differ significantly between patients. Thus the adjustment of calcium for albumin using a single equation remains valid in patients with changes in albumin due to disease. We recommend that for consistent results blood should be taken with the minimum of venous stasis even though the patient's calcium is to be adjusted for albumin.

Blood Flow Velocity↗
PubMed1979

Palate morphology and fetal movements in mice after DPH.

Effects of DPH on fetal development were studied using a dose which produced 65% cleft palate in the CD-1 strain. Generalized developmental retardation and diminution of fetal muscular movements occurred at the early fetal stage. Intermediate stages of palate closure persisted to term, indicating interference with palatine shelf rotation.

Animals↗