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Biomedical subjects

M Barrett

Publications and source records attributed to M Barrett.

At least 19 recordsLinked to original sources
PubMed1999

Relative validity of a food frequency questionnaire among tin miners in China: 1992/93 and 1995/96 diet validation studies.

OBJECTIVE: Diet validation research was conducted to compare the respondents' reporting of dietary intake in a food frequency questionnaire (FFQ) with intake reported in food recalls. Because the population received annual salary increments that could modify food intake, diet validation studies (DVSs) were conducted during two time intervals. DESIGN: A 99-item FFQ was administered by an interviewer twice in a 1-year interval, and responses to each FFQ item were compared with 28 days of interviewer-administered food recalls that were collected in four 1-week intervals during each season of 1992/93. The second validation study in 1995/96 had a similar design to the earlier one. SETTING: A prospective cohort study of lung cancer among tin miners in China was initiated in 1992, with dietary and other risk factors updated annually. SUBJECTS: Among a cohort of high risk tin miners for lung cancer, two different samples (n = 141 in 1992/93, and n = 113 in 1995/96) for each diet validation study were randomly selected from four mine units, that were representative of all worker units. RESULTS: Miners reported a significantly higher average frequency of intake of foods in the food recalls than the FFQ, with few exceptions. Deattenuated Pearson correlation coefficients of the frequency of food intake between the FFQ and food recalls were in the range of -0.40 to 0.72 in both studies, with higher positive correlations for beverages and cereal staples than for animal protein sources, vegetables, fruits and legumes. The percentage of individuals with exact agreement in the extreme quartiles of intake in the food recalls and FFQ ranged from 0 to 100% in both studies. CONCLUSIONS: Among Chinese miners, the range in correlations between the food recalls and the FFQ were due to: (i) market availability of foods during the food recall weeks compared to their annual reported intake in the FFQ; (ii) cultural perception of time; and (iii) differences in how the intake of mixed dishes and their multi-ingredient foods were reported in the recalls vs. the FFQ. The range in the percentage of agreement in the same quartiles and the changes in food intake over time may have implications for the analysis of the diet-disease relationship in this cohort.

Analysis of Variance↗
PubMed1999

Depletion of cutaneous peptidergic innervation in HIV-associated xerosis.

Severe xerosis occurs in approximately 20% of human immunodeficiency virus seropositive patients. Changes in cutaneous innervation have been found in various inflammatory skin diseases and in xerotic skin in familial amyloid. We have therefore carried out a quantitative examination of the cutaneous peptidergic innervation in human immunodeficiency virus-associated xerosis. Immunohistochemistry and image analysis quantitation were used to compare total cutaneous innervation (protein gene product 9.5), calcitonin gene-related peptide, substance P, and vasoactive intestinal peptide peptidergic fibers, at two sites in the skin of human immunodeficiency virus-associated xerosis patients (upper arm, n = 12; upper leg, n = 11) and site-matched seronegative controls (upper arm, n = 10; upper leg, n = 10). Measurement of lengths of fibers of each type was carried out for each subject in the epidermis and papillary dermis, and around the sweat glands. Immunostained mast cells in these areas were counted. Epidermal integrity and maturation were assessed by immunostaining for involucrin. There were significant (Mann-Whitney U test; p < 0.02) decreases in total lengths of protein gene product 9.5 fibers in both epidermis/papillary dermis and sweat gland fields; of calcitonin gene-related peptide innervation in the epidermis/papillary dermis; and of substance P innervation of the sweat glands. There were no differences in the distribution of mast cells, or in the epidermal expression of involucrin. Depletion of the calcitonin gene-related peptide innervation may affect the nutrient blood supply of the upper dermis, and the integrity and function of basal epidermis and Langerhans cells. Diminished substance P innervation of the sweat glands may affect their secretory activity. Both of these changes may be implicated in the development of xerosis.

Adult↗
PubMed1999

Enhancing safety in a pediatric unit.

This descriptive study demonstrates how a group of nurses in the clinical setting can identify and implement a safe sharps disposal strategy to enhance safety. The aim of this small study was to determine a safer method of disposing used sharp items. The findings indicated that many factors can contribute to inappropriate disposal of used sharp items. Changes in practice were implemented following the findings of this study and resulted in enhanced safety in this paediatric unit. In addition, results of the study were utilised to contribute to evidence based nursing practice.

Adolescent↗
PubMed1999

Effect of vitamin intervention on the relationship between GSTM1, smoking, and lung cancer risk among male smokers.

The GSTM1 (glutathione S-transferase mu-1) null genotype is suspected of increasing an individual's susceptibility to tobacco smoke carcinogens because of impaired carcinogen detoxification. We were interested in whether there were differences in lung cancer susceptibility to smoking within the GSTM1 genotypes and the impact of antioxidant supplementation on this. For this purpose, we conducted a nested lung cancer case-control study and evaluated the role of GSTM1 within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. GSTM1 genotype status was determined for 319 cases and 333 controls using a PCR-based approach. GSTM1 was evaluated as an independent risk factor and as an effect modifier of smoking using logistic regression analyses. The GSTM1 null genotype itself was unrelated to risk of lung cancer, odds ratio (OR) = 1.09 and 95% confidence interval (CI), 0.79-1.50, but it may have modified the effect of smoking. There was a suggestion for a stronger association between years of smoking and lung cancer among the GSTM1 null genotype, but the differences between GSTM1 null and present genotypes were not statistically significant (P = 0.12). Furthermore, the smoking association was strongest among those with the GSTM1 null genotype not receiving alpha-tocopherol supplementation, whereas among those receiving alpha-tocopherol, there was no modification by GSTM1 on the association between smoking duration and lung cancer risk. Beta-carotene supplementation did not modify the relationship between GSTM1, smoking years, and lung cancer risk. In conclusion, GSTM1 is not associated with lung cancer risk in male smokers but may confer a higher susceptibility to cumulative tobacco exposure. This association may be attenuated by alpha-tocopherol but not by beta-carotene supplementation.

Adult↗
PubMed1998

Pathogenicity and immunogenicity of different isolates of Teladorsagia circumcincta.

The effects on liveweight gain and development of immunity were studied in lambs trickle infected for 8 weeks with either a benzimidazole-resistant isolate (Moredun ovine resistant isolate, MORI), a multiple benzimidazole + ivermectin-resistant isolate (Moredun caprine resistant isolate, MCRI) or an unselected susceptible isolate (Moredun ovine susceptible isolate, MOSI) of Teladorsagia circumcincta. Plasma pepsinogen concentrations of infected groups were significantly elevated compared to an uninfected control group (P < 0.001) by day 14. The liveweight gains varied markedly but there were no statistical differences between the infected and uninfected control groups at any point in time during the study. Lambs infected with the MORI had significantly lower faecal consistency scores than the other challenged groups on days 7 and 14 (P < 0.05) but from day 21 onwards, faecal consistencies were similar in all of the groups. There was a notable difference in the pre-patent periods of the different isolates with the MOSI producing positive faecal egg counts (FECs) by day 14 of the study. The FECs remained reasonably low once infections had reached patency and there were no further differences between the groups. Following administration of anthelmintic to remove residual worms from the trickle infection, no differences between the infected groups in terms of worm burden or mucosal mast cell numbers were evident as a consequence of a single challenge infection. The changes in genetic code associated with enhanced resistance against anthelmintics do not appear to have resulted in any fundamental alteration of the pathogenicity and immunogenicity of these three isolates of Teladorsagia.

Animals↗
PubMed1998

Antiviral phenylpropanoid glycosides from the medicinal plant Markhamia lutea.

Three new phenylpropanoid glycosides, named luteoside A (3), luteoside B (4), and luteoside C (5), were isolated together with the known compounds verbascoside (1) and isoverbascoside (2) from the roots of the medicinal plant Markhamia lutea. The structures of the new compounds were determined to be 1-O-(3, 4-dihydroxyphenyl)ethyl beta-D-apiofuranosyl(1-->2)-alpha-l-rhamnopyranosyl(1-->3)-4-O- caffeo yl-6-acetyl-beta-d-glucopyranoside, 1-O-(3,4-dihydroxyphenyl)ethyl beta-d-apiofuranosyl(1-->2)-alpha-l-rhamnopyranosyl(1-->3)-6-O- caffeo yl-beta-d-glucopyranoside, and 1-O-(3,4-dihydroxyphenyl)ethyl beta-D-apiofuranosyl(1-->2)-alpha-l-rhamnopyranosyl(1-->3)-6-O- ferulo yl-beta-d-glucopyranoside, respectively, on the basis of chemical and spectroscopic data. All five phenylpropanoid glycosides exhibited potent in vitro activity against respiratory syncytial virus.

Antiviral Agents↗
PubMed1998

Children's subjective identification with the group and in-group favoritism.

Recent developments in social psychology have explained children's preference for members of the in-group in terms of processes of self-categorization and identification with the in-group. In contrast, this study, addressing nationality self-conceptions, examines the possibility that even before subjective identification with the group has occurred, as de facto group members, children will have been exposed to a great deal of positive information about their own national group, which is likely to encourage group-serving judgments. Children who had failed to identify themselves as members of their national group were required in this study to make evaluative judgments about 5 national groups, including their own. Significant preference for the in-group emerged on 2 of 3 measures. It is concluded that subjective identification with the in-group is not a necessary precondition for in-group favoritism.

Adolescent↗
PubMed1997

Thalidomide: a novel therapy for microsporidiosis.

BACKGROUND & AIMS: Microsporidiosis is a common cause of chronic diarrhea in human immunodeficiency virus (HIV)-seropositive individuals and often does not respond to treatment. Fecal tumor necrosis factor alpha (TNF-alpha) is elevated in microsporidiosis; therefore, thalidomide, an anti-TNF-alpha agent, was used as therapy. METHODS: Eighteen subjects with chronic diarrhea caused by Enterocytozoon bieneusi that had not responded symptomatically to albendazole and 1 untreated subject with Encephalitozoon intestinalis received 1 month of thalidomide, 100 mg nocte. Clinical response was assessed by stool frequency and body weight, histological response by light microscopy with villus height/crypt depth ratios and electron microscopy, and immunologic response by fecal TNF-alpha level. RESULTS: Seven subjects with chronic diarrhea due to E. bieneusi had a complete clinical response, and 3 had a partial response to thalidomide. There was a significant decrease in stool frequency from 5.3 to 3.1 per day (P = 0.001), and weight increased significantly by 1.2 kg (P < 0.02). Thalidomide significantly increased the villus height/crypt depth ratio (1.95 to 2.07; P = 0.045) and number of abnormal forms of microsporidia (P < 0.01). Fecal TNF-alpha level nonsignificantly decreased from 17.9 to 8.9 U/mL. There was apparent disruption of all stages of the life cycle of E. intestinalis. CONCLUSIONS: Thalidomide may be an effective therapy for diarrhea and weight loss from E. bieneusi.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Insecticide and Insecticide Metabolite Interactions with Cytochrome P450 Mediated Activities in Maize

In vitro assays were used to determine if organophosphate, carbamate, and synthetic pyrethroid insecticides affected the cytochrome P450 monooxygenase (P450) catalyzed hydroxylation of nicosulfuron, bentazon, cinnamic acid, or lauric acid in maize microsomes. All P450 activities were inhibited approximately 50% by carbaryl, and none were inhibited by permethrin. Hydroxylations of nicosulfuron, bentazon, lauric acid, and cinnamic acid were inhibited by malathion 83, 92, 38, and 0%, respectively. Terbufos was only moderately (36%) inhibitory of in vitro P450 hydroxylation of nicosulfuron. Nicosulfuron hydroxylation was more sensitive than bentazon hydroxylation to inhibition by the insecticides, and both herbicide hydroxylations were more sensitive than lauric acid or cinnamic acid hydroxylations to the insecticides. Since the oxidative metabolites of terbufos were shown to be more potent inhibitors of in vivo nicosulfuron metabolism than terbufos, we examined the effect of terbufos-sulfone on in vivo and in vitro herbicide metabolism. Terbufos-sulfone inhibited metabolism of nicosulfuron and imazethapyr, but not bentazon, in excised corn shoots. Microsomal hydroxylation of nicosulfuron, bentazon, chlorimuron ethyl, and imazethapyr, as well as the desulfuration of malathion, were strongly inhibited (>65%) by terbufos-sulfone. Cinnamic acid hydroxylase appeared to be different from the P450(s) responsible for the pesticide metabolism as it was not inhibited by terbufos-sulfone. However, the data also suggest that malathion, nicosulfuron, bentazon, chlorimuron ethyl, and imazethapyr all share a P450 in common with terbufos-sulfone. Alternatively, there may be separate P450s for the metabolism of the herbicides and malathion, all of which also metabolize terbufos-sulfone. These data show that the inhibition of P450 hydroxylation of nicosulfuron by terbufos-sulfone can explain the injury when maize is exposed to both terbufos and nicosulfuron. However, the insecticides that are the most potent in vitro P450 inhibitors are not necessarily the ones that cause the most herbicide injury in the field.

Journal Article↗
PubMed1996

Intestinal inflammation, ileal structure and function in HIV.

OBJECTIVES: This study examines small intestinal absorption-permeability, intestinal inflammation and ileal structure and function in HIV-positive male homosexuals. METHODS: Thirty HIV-seropositive male homosexuals at various stages of disease underwent intestinal absorption permeability and 111indium leukocyte studies (for quantification of intestinal inflammation). Twenty-six men with AIDS had a dual radioisotopic ileal function test (whole body retention of tauro 23-[75Se]-selena 25-homocholic acid and 58cobalt-labelled cyanocobalamine), and 17 underwent ileocolonoscopy with terminal ileal biopsy. RESULTS: Well, HIV-infected, subjects had normal intestinal absorption-permeability, but both functions were impaired upon the development of AIDS. The median faecal excretion of 111indium in well patients (0.66%) did not differ significantly (P > 0.5) from controls (0.46%), but subjects with AIDS who were well or who had diarrhoea had significant (P < 0.005) intestinal inflammation (1.33% and 2.18%, respectively). The median 7-day retention of tauro 23-[75Se]-selena 25-homocholic acid in well patients with AIDS (38.9%) did not differ significantly (P > 0.2) from controls (39.3%), whereas the absorption of 58cobalt-labelled cyanocobalamine was significantly (P < 0.05) lower than controls (32.1% and 59.4%). Patients with AIDS-diarrhoea had significant (P < 0.001) malabsorption of both the bile acid (7.7%) and vitamin B12 (8.9%) which was more severe than in Crohn's ileitis (14.2% and 30.3%, respectively). Morphometric analyses of ileal biopsies were unremarkable in AIDS. CONCLUSIONS: These studies demonstrate a low-grade enteropathy in patients with AIDS, severe ileal malabsorption in patients with AIDS diarrhoea and relatively minor ileal morphologic changes. Malabsorption of bile acids may play a pathogenic role in patients with AIDS and diarrhoea.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Agreement between emergency physicians and psychiatrists regarding admission decisions.

OBJECTIVE: To determine the level of agreement between emergency physicians (EPs) and psychiatrists regarding the need for acute psychiatric hospitalization and treatment for patients presenting with alleged psychiatric complaints. METHODS: A prospective, cross-sectional assessment of concordance between EPs and psychiatrists in psychiatric admission decisions was performed at an urban county, teaching hospital ED. The participants had been brought to the ED for psychiatric evaluation. The patients were interviewed by an attending EP or a senior-level resident, and a tentative impression and disposition were determined prior to an independent examination and final disposition by a psychiatrist. Strength of physician group agreement was determined using the kappa statistic. RESULTS: The patient mean age was 37.5 +/- 15 years; 51% were men. The most common reasons for evaluation were disruptive behavior (28%), overdose (24%), and danger to self (23%). Of the 156 patients, 47 (28.7%) were sent home without treatment, 10 (6.3%) were determined to need only medical treatment, and 6 (3.7%) were released with outpatient psychiatric treatment. There were 84 (55.7%) patients admitted for psychiatric treatment. The EPs and psychiatrists had only moderate agreement regarding danger to self (kappa = 0.44), danger to others (kappa = 0.40), substance abuse as the primary problem (kappa = 0.50), and need for psychiatric hospitalization (kappa = 0.54). CONCLUSION: Moderate agreement between EPs and psychiatrists in key impressions and admission decisions suggests that shared training in psychiatric decision making, especially during residency training, is desired in this setting.

Adult↗
PubMed1995

Metabolism of herbicides by cytochrome P450 in corn.

Cytochrome P450 monooxygenases (P450) have long been considered a potentially important enzyme system for the detoxification of herbicides in corn and other crop plants. Only recently has herbicide metabolism by P450 in corn microsomes been conclusively demonstrated. Fourteen herbicides in six chemical families have been shown to be metabolized by P450 in corn. P450 is now considered of equal importance to glutathione S-transferases for the metabolism of herbicides in corn. P450 metabolism of herbicides in corn is characterized as an inducible enzyme activity which primarily catalyses hydroxylations and demethylations of the herbicide substrates. Induction of the herbicide metabolizing activity is specific, with only slight changes in the total P450 level accompanying several-fold induction of herbicide metabolism. Turnover rates for herbicide metabolism can equal those for drug metabolism. Microsomes isolated from both shoots and roots metabolize herbicides, although the majority of activities are most fully characterized in microsomes isolated from shoots of young etiolated seedlings. Many questions concerning the P450 metabolism of herbicides in corn remain. These include determining how many P450s are involved in herbicide metabolism and how their levels are regulated. Evidence is gathering that, for a number of the herbicides presently known to be metabolized by P450 in corn, there may be relatively few or even one P450 which metabolizes all the herbicide substrates.

Cytochrome P-450 Enzyme Inhibitors↗
PubMed1994

Physical activity and risk of breast cancer in the Framingham Heart Study.

The authors analyzed data from the Framingham Heart Study to evaluate the association between physical activity and breast cancer risk. Physical activity was ascertained by a physician-administered questionnaire from 2,321 women at the fourth biennial examination conducted in 1954-1956. Breast cancers were identified by self-report, surveillance of admissions to Framingham Union Hospital, and review of death records; all but one were histologically confirmed. During 28 years of follow-up, 117 breast cancer cases were diagnosed among the 2,307 women with data on physical activity and reproductive history (a potential confounder). Analysis was performed using Cox proportional hazards models with age as the underlying time variable. Models were adjusted for age at physical activity assessment, menopausal status, age at first pregnancy, parity, education, occupation, and alcohol ingestion. We observed a gradient of increasing risk of breast cancer with increasing physical activity (trend p = 0.06). The relative risk for women in the highest versus lowest activity quartile was 1.6 (95% confidence interval 0.9-3.0; p = 0.13). Although both moderate-to-heavy leisure and occupational activities were associated with an increased risk, the association was marginally significant only for leisure activity (p = 0.06). Our findings do not support a protective effect of physical activity during adulthood for breast cancer, but suggest an increased risk among more active women.

Adult↗
PubMed1994

The drawings of children and young people with Down's syndrome: a case of delay or difference?

This study compared the performance of 29 children and young people with Down's Syndrome with the performance of 29 verbal-mental-age-matched children without learning difficulties on four drawing tasks and four picture-selection tasks. All eight tasks involved the graphic depiction of a perceptually-present array in which one object was partially occluded by another object. It was found that all participants performed better on the picture-selection tasks than on the drawing tasks, and that the individuals with Down's Syndrome performed significantly worse than the children without learning difficulties on all eight tasks. However, it was also found that the performance of the children without learning difficulties correlated strongly with their verbal mental age, but that the performance of the individuals with Down's Syndrome did not show the same correlation with verbal mental age. Other systematic differences between the drawings of the individuals with Down's Syndrome and those of the children without learning difficulties also occurred. The findings suggest that the drawing development of children and young people with Down's Syndrome may not just be delayed relative to that of children who do not have learning difficulties but may exhibit a qualitatively different pattern.

Adolescent↗
PubMed1993

Cancer associated haemolytic uraemic syndrome developing prior to treatment with cytotoxic agents.

The haemolytic uraemic syndrome has been reported in children and adults with neoplasias treated with mitomycin C and occasionally in adults prior to chemotherapeutic treatment, but it has not been reported in a child prior to the use of cytotoxic drugs. This case report concerns the development of the haemolytic uraemic syndrome in a 7-year-old male child with a metastatic hepatocellular carcinoma. The child had persisting haemolysis and renal impairment, and died three weeks after presentation. Though our experience with similar tumours suggested the outlook would be poor, we had hoped to provide palliative chemotherapy. This proved impossible as optimal chemotherapy could not be used because of the renal impairment.

Anemia, Hemolytic↗
PubMed1991

Early lexical development and maternal speech: a comparison of children's initial and subsequent uses of words.

In Harris, Barrett, Jones & Brookes (1988), we reported the results of a detailed analysis of the initial uses of the first 10 words which were produced by four children. The present paper reports the results of an analysis of the subsequent uses of these 40 words. This analysis reveals that seven qualitatively different patterns of change occurred between the children's initial and subsequent uses of these words; the particular patterns of change which occurred support Barrett's (1986) model of early lexical development. In addition, it was found that, although there was a strong relationship between maternal speech and the children's initial word uses, the relationship between maternal speech and the children's subsequent word uses was very much weaker. These findings indicate that the role of linguistic input in early lexical development may decline quite sharply once the child has established initial uses for words.

Child Language↗