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Biomedical subjects

V White

Publications and source records attributed to V White.

At least 55 records · Page 3Linked to original sources

Pyrido[2,3-d]pyrimidine angiotensin II antagonists.

A series of pyrido[2,3-d]pyrimidine angiotensin II (A II) antagonists was synthesized and tested for antagonism of A II. Compounds with a biphenylyltetrazole pharmacophore and small alkyl groups at the 2- and 4-positions of the pyridopyrimidine ring were found to be the most potent in an AT1 receptor binding assay and in blocking the A II pressor response in anesthetized, ganglion-blocked A II-infused rats. 5,8-Dihydro-2,4-dimethyl-8-[(2'-(1H-tetrazol-5-yl) [1,1'-biphenyl]-4-yl)methyl]pyrido[2,3-d]pyrimidin-7(6H)-one (4a) was one of the more potent compounds in the binding assay and was the most efficacious compound in the A II-infused rat model. Further study of 4a in Goldblatt (2K-1C) rats showed the compound to have oral bioavailability and to be an efficacious and potent compound in a high renin form of hypertension.

Animals↗

Genetic and environmental variation in Eysenck Personality Questionnaire scales measured on Australian adolescent twins.

The Eysenck Personality Questionnaire was administered to 1400 Australian twin pairs aged 11 to 18, and the data were analyzed by a multivariate normal model using the software FISHER. For each scale, attempts were made to transform to normality, about a mean modeled separately for each sex as a quadratic function of age. Variances and covariances were estimated for each sex-zygosity group as a monotone function of age. Evidence for genetic sources of variation were assessed in part by fitting models which allowed for age-dependent, sex-specific, and correlated additive genetic factors, and age-dependent and sex-specific environmental factors, under the assumption that effects of environmental factors common to twin pairs are independent of zygosity. Evidence for genetic factors independent of age and sex was most compelling for Psychoticism and Neuroticism. For Extraversion, if genetic factors exist they would be mostly sex-specific and age-dependent. For the Lie scale there was evidence for, at most, a small component of genetic variation.

Adolescent↗

Idiopathic sclerosing inflammation of the orbit. A distinct clinicopathologic entity.

BACKGROUND: Idiopathic sclerosing inflammation of the orbit is a poorly delineated, fibrosing, immune-mediated entity resulting in significant ocular disability. To characterize this process and propose more specific and effective therapy, clinical and pathologic findings in 16 cases are reviewed. METHODS: The clinical records of 16 patients with biopsy-proven disease were retrospectively reviewed to determine demographic and clinical features, radiologic features, course, management, and outcome. These findings were correlated with pathologic features to describe this unique entity. Immunohistologic characteristics were compared with those of a clinically and histopathologically similar process, retroperitoneal fibrosis. RESULTS: The study included 11 male and 5 female patients, ranging in age from 8 to 81 years. Disease onset was usually unilateral (14/16) and chronic (11/15), with two distinct anatomic presentations, lacrimal (11/16) and apical (3/16), characterized by infiltration (15/16), mass effect (12/16), and visual loss (3/16). The most common signs and symptoms were dull pain (13/16), proptosis (11/16), mild inflammation (11/16), restricted motility (9/16), swelling (9/16), and diplopia (8/16). Two features, a sparse, chronic inflammatory infiltrate, the immunopathologic characteristics of which suggested a cell-mediated process, and a desmoplastic stroma of early onset, dominated the pathologic picture. Treatment with corticosteroids (11/16), radiotherapy for steroid failures (8/11), and observation alone (3/16) was inadequate, resulting in blindness in 3/16 cases, restricted movement in 10/16, and complete resolution in only 2/16 patients. CONCLUSION: Idiopathic sclerosing inflammation of the orbit is a unique clinicopathologic entity, similar to retroperitoneal fibrosis, that is characterized by primary, chronic, and immunologically mediated fibrosis, poor response to corticosteroid treatment or radiotherapy, and frequent visual disability. Early and aggressive immunosuppressive therapy is recommended.

Adolescent↗

Panstromal Schnyder corneal dystrophy. A clinical pathologic report with quantitative analysis of corneal lipid composition.

BACKGROUND: The pathogenesis of Schnyder dystrophy is thought to be a primary abnormality of corneal lipid metabolism resulting in opacification secondary to lipid accumulation. Histochemical investigations have suggested the accumulated lipid includes unesterified cholesterol; however, quantitative analysis has not been done. METHODS: Quantitative biochemical analysis was performed on a corneal button obtained from a patient with clinically and pathologically proven Schnyder dystrophy. Results were compared with four age-, sex-, and size-matched corneal buttons obtained from cadaveric eyes. RESULTS: Corneal lipid accumulated in Schnyder dystrophy predominantly is composed of phospholipid, free cholesterol, and cholesterol ester. These constituents were markedly elevated in the Schnyder cornea when compared with cadaveric control corneas as follows: (1) phospholipid, 23.6 versus 4.05 mg/g; (2) unesterified cholesterol, 6.99 versus 0.52 mg/g; and (3) cholesterol ester, 3.16 versus 0.26 mg/g. CONCLUSION: Phospholipid, unesterified cholesterol and cholesterol ester are the predominant lipids in Schnyder dystrophy. The pathogenesis may be a primary disorder of corneal lipid metabolism.

Chromatography, Gas↗

Changes in sun-related attitudes and behaviours, and reduced sunburn prevalence in a population at high risk of melanoma.

This study aimed to determine trends in exposure to sunlight in the context of a melanoma prevention programme by monitoring the prevalence of sunburn and sun-related attitudes and behaviours. Telephone interviews were conducted in a baseline summer (December 1987 to February 1988) and two subsequent summers after the introduction of the SunSmart health promotion campaign. Interviewing a sample of 4,428 adult residents of the Australian city of Melbourne took place throughout summer on Monday evenings. Behavioural and sunburn data were reported for the previous weekend and relevant attitudinal data were collected. After adjusting for ambient ultraviolet radiation levels and temperature, survey month, age, sex and skin type, a significant reduction in sunburn was found. The crude proportion of sunburnt dropped from 11% to 10% to 7% over 3 years and the adjusted odds ratios (and 95% confidence intervals) were as follows: Year 1/Year 2; 0.75 (CI 0.57-0.99) and Year 1/Year 3; 0.59 (CI 0.43-0.81). Substantial attitudinal shifts occurred over the 3 years. Hat wearing increased significantly each year (19%, 26%, 29%), as did sunscreen use (12%, 18%, 21%). However, the trends in mean proportion of body surface area covered by clothing were less clear cut (0.67, 0.64, 0.71). It is concluded that melanoma risk factor exposure of populations can change fairly rapidly and that well-conducted health promotion campaigns can play a part in producing such change.

Adolescent↗

Self-reported sexually transmitted diseases among family planning clients: ethnic differences in sexual risk behavior and HIV risk reduction.

The relationship between sexually transmitted diseases (STDs) and risk for human immunodeficiency virus (HIV) has been established. Little is known, however, about the relationship between being infected with an STD and initiating HIV risk-reduction behavior. We interviewed 267 young women who were family planning clients of the San Francisco Bay-Area Planned Parenthood clinics, of whom 40% were white, 37% African American, and 23% women of other ethnic origins. Fifty-three percent of the women surveyed reported having been diagnosed with an STD, and 22% reported two or more episodes of infection. African-American women who reported lower educational attainment and being unemployed were more likely to report having been infected with an STD than were women from other ethnic and demographic groups. Ethnic differences were also found in the prevalence of the risk behaviors associated with the self-reported STDs and in the relationship between reporting a history of STD and practicing HIV risk-reduction behavior. Women who reported an STD were significantly more likely to report having a nonmonogamous primary partner. Risk-reduction behaviors associated with a personal history of STD included being less likely to report having asked a sexual partner about his number of previous partners and being more likely to have been tested for antibodies to HIV. Results from this survey suggest that these family planning clients report a frequent history of STDs and that while some have attempted to reduce their risk, these efforts are inadequate. These data underscore a need for ethnically relevant HIV risk-reduction interventions for this population.

Adolescent↗

Melanoma prevention: behavioral and nonbehavioral factors in sunburn among an Australian urban population.

BACKGROUND: To determine the independent contribution of behavioral factors to the occurrence of sunburn, sun protection behavior was assessed over 13 successive summer weekends in a total of 1,655 adults in Melbourne, Australia. METHODS: Telephone survey respondents provided detailed accounts of activities engaged in, time spent outside, and hat, clothing, and sunscreen coverage in the 4 hr around the solar midday on both weekend days, as well as skin type, sociodemographic descriptors, and degree of sunburn experienced. Independent measures of atmospheric temperature and ambient ultraviolet radiation (UVR) were added to individual records. RESULTS: The (mostly recreational) weekend sunburn in this urban sample was strongly associated with UVR, as expected. Temperature at 3 PM, sensitive skin type, youthfulness, and being male were also independently associated with sunburn. After all other predictors were controlled for, the body exposure index (which took into account time outside and hat, clothing, and sunscreen coverage) made a strong independent contribution to the explanation of sunburn (P < 0.001). CONCLUSION: It was concluded that behavior change strategies to prevent malignant melanoma of the skin are warranted.

Adolescent↗

Demographic characteristics and knowledge of BSE of women electing to attend a BSE training program in Victoria, Australia.

Participants in the Mammacheck breast self-examination (BSE) training program were surveyed to assess the characteristics of women choosing to attend BSE training sessions, as well as to assess the factors that related to their BSE practice prior to attending the session. In all, 5,673 women completed questionnaires. In comparison with the general population, women who attended Mammacheck tended to be younger, married, and more highly educated, but did not differ in relation to prior experience of breast problems. Previous BSE practice related predominantly to the amount of knowledge about BSE the women reported that they had acquired before attending a training session. The findings highlight the importance of education and raised the important question of how to teach women with lower education levels and little or no knowledge about BSE. Recommendations are made.

Adult↗

The basis of the histamine assay in skin.

1. The assay of wheal response to histamine injected sub-epidermally has been reviewed. Several discrepant claims were found in earlier work. 2. The saline control injection may evoke a wheal, which if present should be allowed for in the assay procedure. 3. There was no evidence for a limb dominance effect. 4. Using a 3.26 mM (1 mg ml-1) standard solution of histamine acid phosphate (1.18 mM as free base) and 0.1 ml injections, the straight central portion of the assay curve was found to be between 0.3 and 2.3 x 10(-3) mM, as free base, with an ED50 of about 0.018 mM histamine base.

Histamine↗

Cancer-related beliefs and behaviours in Australia.

A sample of 3527 adults aged 16 years and over was interviewed in their homes to obtain Australian data on selected behavioural risk factors for cancer. Four fifths of those interviewed nominated at least one step that individuals may take to reduce their risk of cancer, while 14 per cent believed there were no preventive measures available. Most salient among the preventive steps mentioned were 'not smoking' (58 per cent), dietary measures (30 per cent) and protection of the skin against the sun (13 per cent). Various psychological factors were mentioned by 7 per cent. Beliefs about dietary factors associated with cancer and the direction of the relationship tended to be accurate but there appeared to be some confusion with heart disease dietary risk factors. One third of respondents had at some time noticed a skin sign they thought might be cancer, and this was related (as expected) to latitude of residence. Nearly half had at some time systematically checked their skin for lesions, and 13 per cent said they had done this at least six times in the preceding year. Overall, 78 per cent of women respondents said they had been screened for cervical cancer, and 51 per cent said this had taken place in the past two years. Twelve per cent reported having had a mammogram, 7 per cent that were apparently diagnostic and 5 per cent that were reported to be routine screening mammograms. Overall, 78 per cent said they had done systematic breast self-examination at least once, including 41 per cent who said they had done breast self-examination in the past month and 23 per cent who reported having done it monthly over the previous year.

Adolescent↗

Harderian gland pathology in transgenic mice carrying the MMTV/v-Ha-ras gene.

Twenty-four Harderian glands from 16 transgenic mice carrying a v-Ha-ras gene under the control of the mouse mammary tumor virus promoter were examined histologically upon death of the animals. Eight glands were histologically normal and eleven were hyperplastic. Four additional glands showed predominantly hyperplasia, but also contained foci of dysplasia and in situ carcinoma. One gland contained an adenocarcinoma. The range of pathology observed in the Harderian glands of these transgenic mice was similar to that which arises spontaneously, although hyperplasia, and not adenoma, occurred in these mice as the benign tumor.

Adenocarcinoma↗

Mesectodermal leiomyoma of the ciliary body: case report.

The clinical, light microscopical, and electron microscopical features of a mesectodermal leiomyoma of the ciliary body are presented. This exceptionally rare and apparently benign tumour is considered to be of neural crest origin. In the case described the tumour cells were seen to contain thin filaments with focal densities and conspicuous numbers of mitochondria, and smooth muscle protein was demonstrated by immunohistochemical means.

Adult↗

Usher syndrome: clinical findings and gene localization studies.

The issue of genetic heterogeneity is a critical problem in the localization of the gene(s) for Usher syndrome. Based on the data obtained on families studied to date, the differences between type I and type II Usher syndrome appear quite distinct with regard to auditory and vestibular function. Although the majority of families can be confidently diagnosed as typical type I or type II, clinical investigations revealed four families with findings that did not fit into either of the two more common subtypes. These findings emphasize the critical importance of an in-depth clinical analysis concomitant with the linkage investigation to assure accurate subtyping of Usher syndrome. Based on an analysis of only those families with definite type I or type II Usher syndrome, approximately 17% of the genome can be excluded as a potential site of the gene for type I, and 14% can be excluded as the site for the type II gene. This study will continue until the Usher gene(s) is successfully localized.

Adolescent↗

Usher syndrome: an otoneurologic study.

Usher syndrome is an autosomal recessive disorder characterized by severe hearing loss or deafness and retinitis pigmentosa. Eleven families with 25 affected members were studied. The test battery included genetic studies, clinical examination, audiological, ophthalmologic, and otoneurological tests, and magnetic resonance imaging. Sixteen affected persons had profound hearing loss or were considered anacusic, with absent bilateral vestibular responses. These patients had varying degrees of retinitis pigmentosa. These 16 patients were considered to have type I Usher syndrome. Nine persons were diagnosed as Usher type II with a moderate to profound hearing loss, normal vestibular function, and retinitis pigmentosa of varying degree. Magnetic resonance imaging was normal in all cases. Otoneurological tests indicated no central nervous system disturbances. The conclusion is that hearing loss and balance problems in Usher syndrome are due to inner ear damage with no evidence of central nervous system disturbances. Furthermore, the ataxia seen in Usher type I is due to a combination of retinitis pigmentosa and bilateral peripheral vestibular deficiency.

Adolescent↗

Self examination of the breast: is it beneficial? Meta-analysis of studies investigating breast self examination and extent of disease in patients with breast cancer.

The question whether the aggregated published research suggests that breast self examination is beneficial was explored in a meta-analysis of 12 studies including a total of 8118 patients with breast cancer that related the practice of breast self examination to regional lymph node state or tumour diameter. Based on the six studies for which data were available, 39% of patients (1115/2852) who reported having done breast self examination at least once before their illness had evidence of cancer in the lymph nodes compared with 50% of women (1348/2713) who had not done the examination. Logistic regression analysis showed this difference to be significant (odds ratio 0.66, confidence interval 0.59 to 0.74). Combining six studies which reported the circumstances of detection disclosed that 42% of women (272/652) who found their tumour while doing breast self examination had evidence of cancer in the nodes compared with 46% of women (871/1901) who found the tumour accidentally; this difference was not significant. Analysis of eight studies which used the diameter of the tumour to indicate the extent of disease tended to confirm the findings on lymph node state, in particular the benefit of premorbid breast self examination. Significantly fewer women who had practised the examination before the illness (56%; 1205/2137) had tumours of 2 cm or more diameter compared with women who had not practised the examination (66%; 1500/2260). The combined odds ratio for that analysis was 0.56, confidence interval 0.38 to 0.81. These findings appear to be good evidence of the benefit of encouraging women to practise self examination of the breasts regularly.

Breast↗

Effect of seeding density and time in culture on vascular smooth muscle cell proteins.

The purpose of this work was to determine the effect of seeding density and time in culture on quantitative and qualitative characteristics of myosin in primary cultures of vascular smooth muscle cells (VSMCs). Enzymatically dispersed VSMCs from femoral arteries and saphenous veins of adult dogs were seeded at a density of 10(3)-10(5) cells/cm2 and assayed after 7 days or at 10(5) cells/cm2 and assayed between 1 and 10 days. Myosin, actin, and total protein contents as well as electrophoretic and immunoreactive characteristics of myosin heavy chains (MHCs) were determined. Total and contractile protein contents were independent of seeding density and increased with time in culture. Freshly dispersed cells exhibited two MHCs (MHC-1 and MHC-2) but, within 24 h after culturing, only cells attached to the dish expressed a third protein band (MHC-3), which had electrophoretic mobility and immunoreactivity similar to purified platelet MHC. MHC-3 appeared before onset of cell division and, by 4 days in culture when cells were proliferating, became the dominant MHC form. Loss of MHC-1 and MHC-2 could be prevented by growing cells in a serum-free, defined media that prevented proliferation. These data indicate that seeding density does not affect myosin content, but that with time in culture expression of a MHC with characteristics similar to nonmuscle myosin occurs. Expression of MHC-3 is associated with cell attachment, whereas loss of MHC-1 and MHC-2 requires proliferation.

Actins↗