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Biomedical subjects

D Crawford

Publications and source records attributed to D Crawford.

At least 109 records · Page 6Linked to original sources
PubMed1987

Effects of human immunodeficiency virus (HIV) on the cytotoxic response to Epstein Barr virus (EBV) transformed B lymphocytes.

The human immunodeficiency virus (HIV) may interact with the Epstein Barr virus (EBV) indirectly by effects on the T4 lymphocyte or directly by effects on EBV transformed B lymphocytes. We have confirmed the susceptibility of EBV transformed B lymphocytes to productive HIV infection, and have evaluated the cytotoxic activity of HIV seronegative and seropositive donors after sensitization by their autologous EBV infected (monoinfected) or EBV and HIV infected (coinfected) transformed cell lines in a 51Cr release cytotoxicity assay. When sensitized by the coinfected cell line and assayed against monoinfected and coinfected cell lines, the cytotoxic activity of the seronegative donors was inhibited when compared to the cytotoxic effectors sensitized by the monoinfected B cell line. The inhibition appeared to be unrelated to direct HIV infection of the T4 effector cells and was reversible by addition of recombinant interleukin-2. Although deficient in their EBV cytotoxic activity in comparison to the seronegative donors, the HIV seropositive donors lysed the coinfected cell line better than the monoinfected cell line, whether or not HIV superinfected cells were used during the sensitization phase. In HIV seronegative donors, HIV may inhibit the immune response to EBV transformed B lymphocytes. This inhibition is not observed in HIV seropositive donors. These studies suggest the development of cytolytic effector mechanisms directed at HIV infected cells during HIV infection.

B-Lymphocytes↗
PubMed1987

Nutrition awareness, health practices and dietary supplementation.

A detailed questionnaire was administered by mail to a random sample of 1000 Melbourne residents in June 1984 in order to assess their understanding of the Australian dietary guidelines. Seven hundred and thirty people returned questionnaires. The respondents were categorized as regular dietary supplementers (RS, n = 245); irregular dietary supplementers (IS, n = 84), or non-supplementers (NS, n = 370). Comparisons of the responses of these groups showed that more RS and IS women reported that they drank alcohol and experienced occupational stress; more RS and IS practised meditation-relaxation, and fewer RS were smokers. More of the RS expressed satisfaction with their nutrient status, whereas more of the IS and NS were dissatisfied about their intakes of fibre, starch, salt, sugar and calories. More of the RS practised a range of specific activities related to both orthodox and non-orthodox dietary recommendations, and they attached greater importance to them for their health. They had also referred to more sources of nutrition information in the year preceding the study. The results suggest that regular dietary supplementers are more oriented toward both orthodox and 'alternative' nutrition information than other people. However, they are likely to be a more receptive audience for nutritional or dietary recommendations, such as the dietary guidelines, than other sections of the general population.

Australia↗
PubMed1987

The mouse bioassay for the detection of estrogenic activity in rodent diets: III. Stimulation of uterine weight by dextrose, sucrose and corn starch.

We have shown previously that mice fed the American Institute of Nutrition (AIN-76A) purified diet experience a significant increase in uterine:body weight (U:BW) ratios when compared to the U:BW ratios of mice fed a closed formula natural ingredient diet (Certified Rodent Chow #5002) for 7 days. The AIN-76A purified diet contains 5% corn oil and 65% carbohydrates with 50% of the carbohydrates coming from sucrose or dextrose and 15% from corn starch. The objective of this study was to determine whether the fat and carbohydrate content contributed to the unexpected uterine growth promoting activity observed in mice fed the AIN-76A diet. Estrogen bioassays were performed using CD-1 mice weaned at 15 days of age and assigned randomly to the negative control diet (Certified Rodent Chow #5002) or to the positive control diet (#5002) containing 4 or 6 ppb DES for comparison or to the test diets. The test diets were prepared by adding sucrose, dextrose, corn starch, corn oil or soybean oil to the #5002 negative control diet at 10% w/w concentration. Uterine:BW ratios were determined at 7 days post-feeding. The uterine weights and the U:BW ratios of mice fed the test diets containing dextrose, corn starch, or corn oil, were increased significantly (P less than 0.05) over those of mice fed the negative control diet. The uterine weights and U:BW ratios of mice fed the test diets containing sucrose or soybean oil also were increased over those of mice fed the negative control diet. These increases in uterine weights and U:BW ratios were similar to the increases in uterine weights and U:BW ratios of mice fed the positive control diet containing 4 ppb DES. It was concluded that the fats and carbohydrates caused preferential increases in uterine weights and in U:BW ratios and may account for the estrogen-like uterine growth promoting activity observed in mice fed the AIN-76A purified diet.

Animal Feed↗
PubMed1986

Adjuvant radiotherapy and chemotherapy in breast cancer.

Three hundred and twenty-two women with involvement of axillary lymph nodes following surgery for operable breast cancer were randomized to receive either postoperative radiotherapy, chemotherapy (CMF) or radiotherapy followed by chemotherapy. There was an increase in disease free interval in pre- and postmenopausal patients receiving radiotherapy and chemotherapy regardless of the number of nodes involved. However, there was a trend towards an improvement in disease related survival only in those patients with more than three nodes involved.

Aged↗
PubMed1985

Separation of immature and adult rat hepatocytes into distinct subpopulations by centrifugal elutriation.

Several subpopulations of hepatocytes with increasing cell diameters were isolated, the smaller cells were attributed to the periportal area, the larger ones to the perivenous region. Profiles of total cytochrome P-450, benzphetamine N-demethylation and ethoxyresorufin O-deethylation, cytochrome c-reductase, glucose-6-phosphatase and GPT activities were determined. With adult hepatocytes an increasing cytochrome P-450 concentration with increasing cell diameter could be observed, paralleled by increasing activities of monooxygenases. Glucose-6-phosphatase and GPT also revealed increasing activities with increasing cell diameter, but cytochrome c-reductase did not show a distinct zonation. Immature hepatocytes (age 11-15 days) were smaller, more fragile, and could not be isolated with the same enzyme solution as adult hepatocytes. They did not show any zonation of cytochrome P-450 whereas the zonation of the monooxygenases was almost fully developed. For cytochrome c-reductase a zonation with higher activities in the perivenous cells could be demonstrated, in contrast to the lack of zonation in adult rats. Glucose-6-phosphatase showed a decline with increasing cell diameter in immature hepatocytes, whereas GPT did not show any zonation. In rats aged 20 days the zonation of these parameters in liver was in between younger and older animals.

Alanine Transaminase↗
PubMed1985

Demonstration of a leukemia-associated antigen (CAMAL) in peripheral blood leucocytes of bone marrow transplant patients prior to relapse.

We have previously described a monoclonal antibody (CAMAL-1) that reacts in an indirect immunoperoxidase slide test at high frequency with cells of patients with acute nonlymphoblastic leukemia (ANLL), both at presentation and in remission (1). This article reports on a 12-month blind study carried out on peripheral blood leukocytes (PBL) of patients who had received bone marrow transplants for acute leukemias. PBL of patients attending the Royal Marsden Hospital were sent as cytospins to the University of British Columbia for staining and screening. Results of this study showed the following: of the 15 patients who remained in remission during the period of the study, 13 showed no abnormal increase in reactivity with CAMAL-1 (2 patients did show increased levels of reactivity over time); of the four patients relapsing but surviving within this period with ANLL, all showed elevated numbers of cells reactive with CAMAL-1 as long as 3 months prior to relapse (the two relapsing patients who had acute undifferentiated leukemia and acute lymphoblastic leukemia did not show elevations of CAMAL-1-reactive cells); of the 14 patients dying during this time of causes other than leukemia, none had elevated levels of CAMAL-1-reactive cells--and, of 4 patients dying in relapse, all had extremely elevated levels of CAMAL-1-reactive cells as long as 4 months prior to relapse. The implications of these observations are discussed.

Acute Disease↗
PubMed1985

The assessment of persistent bradycardia in prenatal life.

Twelve patients with persistent fetal bradycardia were referred for echocardiographic assessment; in 10 patients the fetus had complete heart block, six isolated and four with associated structural heart disease. In the remaining two patients an atrial arrhythmia was producing a fetal sinus bradycardia. Complete heart block with structural heart disease has a poor prognosis. Isolated complete heart block has a good prognosis if the pregnancy is carefully managed. A sinus bradycardia due to atrial ectopic beats is a benign arrhythmia. Echocardiographic assessment of the heart can give an accurate prognosis in fetal bradycardia and provide a basis for appropriate obstetric management.

Arrhythmias, Cardiac↗
PubMed1984

Australian dietary supplementation practices. Health and dietary supplements.

A random mail survey of 726 adults living in the Adelaide metropolitan area was carried out to determine the prevalence of dietary supplementation and its relationship to health. In the month before the survey, 37% of men and 53% of women had taken some form of supplement. The most popular supplements were bran, multivitamins, B-complex vitamins, vitamin C and wheatgerm. Most supplementation was used regularly (daily or almost daily) and over a prolonged period. Although the subjects who took supplements did not use medical facilities more often than those who took none, they reported having more bouts of minor illness in the preceding year. They also reported the more frequent occurrence of minor symptoms, and took more unprescribed medications than did those who did not use dietary supplements.

Australia↗
PubMed1984

Electron microscopy of urinary calculi--some facts and artefacts.

Material in urinary calculi is prone to irradiation damage during electron microscopy and this suggests the need for care in the interpretation of data. It is shown, however, that minimum-dose transmission microscopy is feasible for single-crystal electron diffraction work, and that although internal damage in severe, morphological artefacts are unlikely in the SEM unless the incident electron flux is greater than 10(-13) A nm-2. During EDX microanalysis, the detection of light elements is impaired by irradiation effects unless a minimum-dose procedure is used. For the preparation of SEM samples, artefacts can be created by cleaving air-dried material - and it is therefore important to consider more lengthy preparation methods such as cryogenics.

Calcium Oxalate↗
PubMed1984

New storage procedure for human tumor biopsies prior to estrogen receptor measurement.

Breast tumor biopsies required for steroid receptor determination are normally frozen in liquid nitrogen and stored until assay. However, some limitations of this type of storage exist. To try to both eliminate the need for liquid nitrogen and as part of a study of serial assays on a single tumor biopsy, alternative storage media were investigated. This study shows that storage of breast tumor biopsies at -20 degrees in sucrose buffer made 50% in glycerol prevented the tissues from freezing, yet retained the specific estrogen receptor content both quantitatively and in terms of molecular form (8S:4S ratio). Receptor was stable for up to 100 days, and individual samples could be successfully reassayed throughout this period. Forty-four biopsies from 40 patients were halved, and one section from each was stored in liquid nitrogen, while the other was stored in sucrose:glycerol. Overall, the correlation of receptor content between the two storage methods was good. Using a clinical cutoff value of 20 fmol/mg cytosol protein, only one sample of the 44 would have been classified differently after storage in the two media. Progesterone receptor in biopsies stored in sucrose:glycerol also appears to be stable for at least a limited period.

Biopsy↗
PubMed1984

Slim and obese children's perceptions of physical activities.

Two studies of children's perceptions of physical activities were carried out. The first examined the views of 600 ten-year-olds drawn from seven regions of Australia; the second examined the views of 528 ten-year-olds from South Australia. Both studies revealed consistent differences between the perceptions of obese and slim children. Obese children evaluated endurance activities more negatively and flexibility-coordination activities more positively than slim children. These differences were highly stable between samples and over time.

Attitude↗
PubMed1982

Alcohol dependence and taste-mediated learning in the rat.

Alcohol dependence and taste-mediated learning were investigated in the rat using intubation procedure to produce dependence, an experimenter-controlled conditioned stimulus (CS) flavor infusion procedure, and behavioral criteria to assign conditioning alcohol dosage. Stress produced by the experimental procedures (e.g., handling, stomach distention) produced flavor aversions, and these aversions were attenuated by small alcohol doses. When stress was reduced and made less associable with the flavor CS, alcohol dependence, by itself, did not protect against the development of alcohol-induced taste aversions. Alcohol withdrawal produced aversions for an associated flavor, but these aversions were attenuated by pairing the flavor with small doses of alcohol. Thus, the relief of alcohol withdrawal illness did not produce preferences for associated flavors, but it did protect against the development of taste aversions.

Alcoholism↗
PubMed1981

Oestrogen-receptor status and endocrine therapy of breast cancer: response rates and status stability.

The concentration of cellular oestrogen receptor (RE) was measured in both the soluble and nuclear-pellet fractions of biopsies from 1,000 breast cancers. Data suggest that functional steroid RE is always in equilibrium between the soluble and nuclear fractions. However, biopsies from only one-third of patients contained detectable amounts of high-affinity RE in both fractions. Thirty patients out of 42 (71%) whose biopsies contained RE in both fractions, showed objective remission after receiving some form of hormonal manipulation as sole treatment. Response rates in the other categories ranged from 9% for those whose biopsies contained no detectable RE to 24% for those who displayed soluble RE alone. The presence of RE in both fractions of primary disease, whereas RE-negativity was maintained during progression from primary to secondary disease. Other aspects of RE status in relation to stage of disease are analysed.

Adult↗
PubMed1981

Detection of placental protein five (PP5) and pregnancy-specific glycoprotein (SP1) in benign and malignant breast disease.

Sensitive radioimmunoassays for the placental proteins PP5 and SP1 were used to investigate possible ectopic synthesis of these proteins by breast tumors. Elevated serum levels of the proteins were found in a small proportion of patients who had undergone mastectomy for malignant tumors, but little useful information on tumor spread could be gained from such measurements. In two patients with elevated pre-operative serum PP5, the levels fell to normal upon resection of the tumor, suggesting that PP5 may be a product of the tumor. PP5 and SP1 were found to be present in the majority of homogenates of malignant and benign breast lesions; the highest concentrations of SP1 were found in malignant tumors, whereas with PP5, especially high levels were found in cases of simple cystic disease.

Adenofibroma↗