Search PubMed⌕ Search

Biomedical subjects

G Robinson

Publications and source records attributed to G Robinson.

233 records · Page 13Linked to original sources
PubMedDate not supplied

In vitro HIV1 infection of human cervical tissue.

Heterosexual intercourse is the major mode of transmission of the human immunodeficiency virus (HIV) worldwide. Heterosexual transmission of HIV is particularly important in Africa and is increasing in the developed world. The mechanism of HIV infection of the female genital tract with HIV and subsequent events leading to clinical infection are not fully understood. In particular, the primary cellular targets of HIV infection in the female genital tract have not been determined. We have established an in vitro model for studying HIV infection of the human adult cervix by HIV. Human cervical mucosal explants were briefly exposed to HIV strains of different tropism and maintained in organ culture for 7 days. HIV infection detected by immunohistochemistry and in situ hybridization was only observed in cervical explants exposed to macrophage tropic strain HIV1Ba-L. HIV-infected cells were located in submucosa and had the morphology and distribution of macrophages. While CD4+/CD3+ T cells were still present at day 7 in the organ culture tissue, no infection of cervical explants was seen with T cell tropic strains even in the presence of phytohaemagglutinin and IL2. This model system will enable study of the dynamics of HIV infection of the human cervix and analysis of possible prophylactic or therapeutic strategies.

Adult↗
PubMedDate not supplied

The localization and expression of the renin-angiotensin system in the human placenta throughout pregnancy.

All the components of the renin-angiotensin system (RAS), including the AT(1)receptor, have previously been shown to be present in the human term placenta. However, the presence of the RAS components has not been fully investigated in the human placenta throughout pregnancy. The aim of this study was to examine the localization of the angiotensin receptors AT(1)and AT(2)using immunocytochemistry and the expression of prorenin, angiotensinogen and the AT(1)and AT(2)receptor mRNA using RT-PCR in the human placenta in the first, second and third trimesters of pregnancy. Localization of the AT(1)receptor was shown throughout gestation in the syncytiotrophoblast, cytotrophoblast, Hofbauer cells and the fetal vascular endothelium. Expression of mRNA for prorenin, angiotensinogen and the AT(1)receptor was shown in the placenta throughout gestation. However, localization or mRNA expression of the AT(2)receptor was not detected in any of the placental samples studied. These results clearly show the expression of a majority of the components of the RAS in the placenta from early gestation onwards. Therefore, these results suggest that the RAS may have a role in the human placenta throughout gestation.

Angiotensin II↗
PubMedDate not supplied

Comparison of serum beta-hexosaminidase isoenzyme B activity with serum carbohydrate-deficient transferrin and other markers of alcohol abuse.

We have compared beta-hexosaminidase (beta-Hex) activity, carbohydrate-deficient transferrin (CDT), mean corpuscular volume (MCV), gamma-glutamyltransferase (GGT), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values in serum from male alcoholic patients with the corresponding values in moderate and non-drinking subjects. The total beta-Hex activity was 2.5 times higher in the alcoholics than in the moderate drinkers and this increase was mainly due to a 5-fold increase in the activity of the B-isoform of the enzyme. This was expressed as a percentage of the total beta-Hex activity and called 'beta-Hex B%'. Strong correlations were found between alcohol consumption (g/ day) and beta-Hex B% (r = 0.757, P < 0.001, n = 42), alcohol consumption and CDT (r = 0.671, P < 0.001, n = 42), and beta-Hex B% and CDT (r = 0.628, P < 0.001, n = 57). Serum beta-Hex B% had a sensitivity of 94% and a specificity of 91% in detecting alcoholic drinking of > 60 g/day. As a single marker of alcoholic drinking, it was markedly more sensitive than MCV and the liver enzymes GGT, AST and ALT, and slightly more sensitive than serum CDT (94 vs 83%). At the CDT cut-off level of 20 U/l, 17% of the moderate and non-drinkers would have been classified as alcoholic drinkers and 17% of the alcoholics would have been classified as moderate drinkers. Some of these misclassifications were eliminated if the beta-Hex B% results were taken into account. We suggest that serum beta-Hex B% can be a useful and inexpensive laboratory test for alcohol abuse.

Adult↗
PubMedDate not supplied

Anger, harassment, and cardiovascular reactivity among Chinese and Indian men in Singapore.

OBJECTIVE: This experiment examined psychological and cardiovascular responses to experimental harassment among Chinese and Indian men in Singapore who differed in levels of dispositional anger. METHODS: Eighty-four Chinese and Indian men participated in a laboratory experiment on cardiovascular reactivity in which mood was rated and heart rate and blood pressure were measured during computer tasks in which they were either harassed or allowed to complete the tasks without interruption. RESULTS: Comparison of systolic reactivity to harassment and nonharassment indicated, as expected, that reactivity was greater after harassment. Furthermore, a significant race by dispositional anger by harassment effect was obtained for systolic reactivity that indicated different patterns of reactivity for Chinese and Indian participants. In the absence of harassment, Chinese participants showed low systolic reactivity regardless of their level of dispositional anger, whereas systolic reactivity increased as a function of dispositional anger when they were harassed. For Indians, however, systolic reactivity was a positive function of dispositional anger both when they were harassed and not harassed. CONCLUSIONS: These results suggest stronger cardiovascular reactivity to stress among Indian than among Chinese men. This seems to be particularly true for Indians high in dispositional anger.

Adolescent↗
PubMedDate not supplied

Impact of nutritional status on DRG length of stay.

A prospective audit of 100 admissions to a general medical unit was performed to determine the relationship of the initial nutritional status of the patients to the actual length of stay and hospital charges. These data then were compared with the allowed length of stay and estimated reimbursement under the prospective payment system of diagnosis-related groups (DRGs). Forty-five percent of the malnourished patients were hospitalized longer than that allowed under DRGs, compared to 30% for normal patients and 37% in the borderline group. The average length of stay was 15.6 +/- 2.2 days in the malnourished group compared to approximately 10 days in the other two groups (p less than 0.01). Although the estimated base DRG reimbursement was similar in all three groups ($4352-$5124), the actual hospital charges were significantly greater in the malnourished ($16,691 +/- 4389) and borderline ($14,118 +/- 4962) groups compared to normals ($7692 +/- 687), (p less than 0.01). The DRG system will have an adverse financial impact in the care of malnourished patients. It is suggested that early recognition of malnutrition and aggressive treatment may lead to a decrease in the length of stay and cost deficit incurred by malnourished patients.

Aged↗
PubMedDate not supplied

Application of a portable microprocessor-based system for electrophysiological field testing of neurotoxicity.

A portable microprocessor-based system designated PEARL II has been developed for neurotoxicity testing in human populations. PEARL II provides a flexible and powerful data acquisition capability to record sensory evoked potentials (auditory, visual and somatosensory), event-related slow potentials (CNV, P300) and behavioral measures. PEARL II has been mounted in a mobile laboratory to facilitate field testing. Data obtained in pediatric lead studies are provided for illustration.

Brain Stem↗
PubMedDate not supplied

Hepatitis B vaccination and screening for markers at a sexually transmitted disease clinic for men.

In Ontario, persons with multiple sexual partners became eligible for free hepatitis B vaccine in late 1991. From January 1992 to January 1993, a sexually transmitted disease (STD) clinic for men in Toronto was one site where the vaccine was delivered. The objectives of the study were to determine the seroprevalence of hepatitis B markers, the series completion rate for hepatitis B vaccine, and the seroprevalence of hepatitis B markers required before screening would be a cost-effective endeavour. The seroprevalence of anti-HBs in gay/bisexual men was 18.1% (95% CI: 15.3%-20.7%) and in heterosexual men was 5.1% (95% CI: 3.0-9.7%). HBsAg was detected in 0.9% (95% CI: 0.04%-1.8%) of gay/bisexual men and was undetected in heterosexual men. Completion of a full vaccine series was 47% for gay/bisexual men and 25% for heterosexual men (p = 0.04). A combined seroprevalence of HBsAg and anti-HBs of at least 30-64%, depending on cost figures used, was required to justify screening prior to completion of a full series.

Adolescent↗
PubMedDate not supplied

Insecure unit.

Explore the source record for details and available documents.

Female↗
PubMedDate not supplied

Breast cancer.

Explore the source record for details and available documents.

Authorship↗
PubMedDate not supplied

Differential sensitivity of human nonpregnant and pregnant myometrium to calcitonin gene-related peptide.

OBJECTIVES: Calcitonin gene-related peptide (CGRP) is a smooth muscle relaxant with potent vasodilating properties. To investigate its inhibitory effects on human myometrial contractions, we obtained excised human myometria from term pregnant, with and without spontaneous labor, and nonpregnant patients. METHODS: Myometrial strips were mounted in tissue baths in which contractile activity was recorded. Spontaneously contracting tissues in vitro were exposed to increasing concentrations of CGRP (10(-11)-10(-7) mol/L). Tissues without spontaneous contractions were induced to contract with either oxytocin or KCl before being exposed to CGRP. The IC25 (CGRP concentration required to inhibit contractility by 25%) was used as comparison between groups. RESULTS: Tissues with spontaneous or oxytocin-induced in vitro contractions responded equally to CGRP relaxation. Tissues induced to contract with KCl in vitro required approximately 2000 times more CGRP for equal relaxation. In tissues with spontaneous or oxytocin-induced in vitro contractions, those from pregnant unlabored patients were 60 times more sensitive to CGRP than those from pregnant labored or nonpregnant patients. The letter two groups responded equally to CGRP. CONCLUSIONS: The sensitivity of myometrial tissues to CGRP relaxation in vitro is increased from the nonpregnant to the pregnant term state. This increased sensitivity is lost once patients develop spontaneous term labor. The relative ineffectiveness of CGRP in relaxing KCl-induced in vitro contractions probably reflects its known mechanism of action, namely the hyperpolarization of cell membrane potentials via activation of membrane potassium channels.

Adult↗