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Biomedical subjects

B Williams

Publications and source records attributed to B Williams.

At least 181 records · Page 10Linked to original sources
PubMed1999

Vascular endothelial growth factor and microvascular permeability.

Vascular Endothelial Growth Factors (VEGFs) are endogenously produced vascular cytokines which result in angiogenesis, vasodilatation, and increased microvascular permeability in vivo. They are endothelial specific and result in mitosis, migration, stress fiber formation and increased permeability of endothelial cells in culture. They have been critically implicated in a host of pathological conditions including solid tumor growth and diabetes, and been proposed as a therapy for coronary and peripheral ischemic disease. However, the potent permeability-enhancing properties of VEGFs are very poorly understood. The pharmacology, signal transduction pathways, intracellular signaling mechanisms, and ultrastructural changes which result in increased permeability are still not clear. This review discusses the available evidence for how VEGFs increase permeability in vivo, and some of the pitfalls in interpreting experiments which do not take into account the vasoactive properties of VEGFs. It also discusses the clinical implications of the permeability enhancing effect of VEGFs, and the relevance of these studies to development of new therapies.

Animals↗
PubMed1999

Women in medicine: still a long way to go, baby.

No doubt about it, women have come a long way in the medical profession. The average female enrollment in our nation's medical schools is 42% and growing. Women physicians are entering more non-traditional fields and are running successful practices. They're working to change attitudes and overcome obstacles that have traditionally barred them from thriving in such a demanding field. They're getting creative with options that allow them to pursue their dream while raising a family. But the bars are still up on some windows, namely the ones that peek into the halls of organized medicine. Professional organizations and medical schools are still largely run by men. The Tennessee Medical Association recognizes the discrepancy and is working to make some changes. TMA's Executive Assistant for Membership Services Phyllis Franklin says leadership is rethinking the entire structure of the Association in the light of changing demographics. "We're looking at younger physicians, minorities, female physicians, academicians, and students; we want to get them involved in organized medicine," she says. The leadership structure is one area that is slowly changing. Franklin admits while the hierarchy has been male-dominated, the Association can now claim its first female vice president, Dr. Phyllis Miller of Chattanooga. "We don't have a lot of women leaders, but it's getting better, and there are a lot more opportunities in the committee structure." TMA officials say surveys are forthcoming that will help them gauge the needs and wants of its female membership and hopefully increase further that 11% number, up from 8.9% two years ago. In the meantime, Franklin encourages women physicians to make their wishes known. "Instead of not joining the TMA because of perceived barriers or stumbling blocks, we would certainly prefer that they help us identify obstacles and give us the opportunity to do what we can to make membership more appealing," she says. "This Association is truly for all physicians."

Attitude of Health Personnel↗
PubMed1999

Spreading the word.

Explore the source record for details and available documents.

Marketing of Health Services↗
PubMed1998

Risk factors for development of sexually abusive behaviour in sexually victimised adolescent boys: cross sectional study.

OBJECTIVE: To identify factors that may increase the risk of a sexually victimised adolescent boy developing sexually abusive behaviour. DESIGN: Sexually victimised boys who had sexually abused other children were compared with sexually victimised boys who had not done so. SETTING: Social services departments in south east England were invited to refer sexually abused and sexually abusing boys to a London postgraduate teaching hospital. SUBJECTS: 25 adolescent boys aged between 11 years and 15 years and 11 months. MAIN OUTCOME MEASURES: Adjusted odds ratios estimated from unconditional logistic regression. RESULTS: Unadjusted odds rations for witnessing (8.1) as well as experiencing (18.0) intrafamilial violence and discontinuity of care (7.2) discriminated boys who had sexually abused from others who were solely victims of sexual abuse. Only the adjusted odds ratios for witnessing intrafamilial violence (39.7) discriminated the two groups. CONCLUSIONS: The risk of adolescent boys who have been victims of sexual abuse engaging in sexually abusive behaviour towards other children is increased by life circumstances which may be unrelated directly to the original abusive experience, in particular exposure to a climate of intrafamilial violence. Our findings have implications for the management of boys found to have been sexually abused and raise important questions about the possibility of secondary prevention of subsequent abusive behaviour in those at greatest risk.

Adolescent↗
PubMed1998

Cooperative interactions between the central spindle and the contractile ring during Drosophila cytokinesis.

We analyzed male meiosis in mutants of the chickadee (chic) locus, a Drosophila melanogaster gene that encodes profilin, a low molecular weight actin-binding protein that modulates F-actin polymerization. These mutants are severely defective in meiotic cytokinesis. During ana-telophase of both meiotic divisions, they exhibit a central spindle less dense than wild type; certain chic allelic combinations cause almost complete disappearance of the central spindle. Moreover, chic mutant spermatocytes fail to form an actomyosin contractile ring. To further investigate the relationships between the central spindle and the contractile ring, we examined meiosis in the cytokinesis-defective mutants KLP3A and diaphanous and in testes treated with cytochalasin B. In all cases, we found that the central spindle and the contractile ring in meiotic ana-telophases were simultaneously absent. Together, these results suggest a cooperative interaction between elements of the actin-based contractile ring and the central spindle microtubules: When one of these structures is disrupted, the proper assembly of the other is also affected. In addition to effects on the central spindle and the cytokinetic apparatus, we observed another consequence of chic mutations: A large fraction of chic spermatocytes exhibit abnormal positioning and delayed migration of asters to the cell poles. A similar phenotype was seen in testes treated with cytochalasin B and has been noted previously in mutants at the twinstar locus, a gene that encodes a Drosophila member of the cofilin/ADF family of actin-severing proteins. These observations all indicate that proper actin assembly is necessary for centrosome separation and migration.

Actins↗
PubMed1998

Treatment of rheumatoid arthritis with recombinant human interleukin-1 receptor antagonist.

OBJECTIVE: To evaluate the efficacy and safety of interleukin-1 receptor antagonist (IL-1Ra) in patients with rheumatoid arthritis (RA). METHODS: Patients with active and severe RA (disease duration <8 years) were recruited into a 24-week, double-blind, randomized, placebo-controlled, multicenter study. Doses of nonsteroidal antiinflammatory drugs and/or oral corticosteroids (< or =10 mg prednisolone daily) remained constant throughout the study. Any disease-modifying antirheumatic drugs that were being administered were discontinued at least 6 weeks prior to enrollment. Patients were randomized to 1 of 4 treatment groups: placebo or a single, self-administered subcutaneous injection of IL-1Ra at a daily dose of 30 mg, 75 mg, or 150 mg. RESULTS: A total of 472 patients were recruited. At enrollment, the mean age, sex ratio, disease duration, and percentage of patients with rheumatoid factor and erosions were similar in the 4 treatment groups. The clinical parameters of disease activity were similar in each treatment group and were consistent with active and severe RA. At 24 weeks, of the patients who received 150 mg/day IL-1Ra, 43% met the American College of Rheumatology criteria for response (the primary efficacy measure), 44% met the Paulus criteria, and statistically significant improvements were seen in the number of swollen joints, number of tender joints, investigator's assessment of disease activity, patient's assessment of disease activity, pain score on a visual analog scale, duration of morning stiffness, Health Assessment Questionnaire score, C-reactive protein level, and erythrocyte sedimentation rate. In addition, the rate of radiologic progression in the patients receiving IL-1Ra was significantly less than in the placebo group at 24 weeks, as evidenced by the Larsen score and the erosive joint count. IL-1Ra was well tolerated and no serious adverse events were observed. An injection-site reaction was the most frequently observed adverse event, and this resulted in a 5% rate of withdrawal from the study among those receiving IL-1Ra at 150 mg/day. CONCLUSION: This study confirmed both the efficacy and the safety of IL-1Ra in a large cohort of patients with active and severe RA. IL-1Ra is the first biologic agent to demonstrate a beneficial effect on the rate of joint erosion.

Adolescent↗
PubMed1998

Phylogenetic analysis of anthropoid relationships.

The relationships of anthropoids to other primates are currently debated, as are the relationships among early fossil anthropoids and crown anthropoids. To resolve these issues, data on 291 morphological characters were collected for 57 taxa of living and fossil primates and analyzed using PAUP and MacClade. The dental evidence provides weak support for the notion of an adapid origin for anthropoids, the cranial evidence supports the tarsier-anthropoid hypothesis, and the postcranial evidence supports a monophyletic Prosimii and a monophyletic Anthropoidea. Combining these data into a single data set produces almost universal support for a tarsier-anthropoid clade nested within omomyids. Eosimias and Afrotarsius are certainly members of this clade, and probably basal anthropoids, although the Shanghuang petrosal may not belong to Eosimias. The tree derived from the combined data set resembles the tree derived from the cranial data set rather than the larger dental data set. This may be attributable to relatively slower evolution in the cranial characters. The combined data set shows Anthropoidea to be monophyletic but the features traditionally held to be anthropoid synapomorphies are found to have evolved mosaically. Parapithecines are the sister taxon to crown anthropoids; qatraniines and oligopithecids are more distantly related sister taxa. There is support for a relationship of a Tarsius + Anthropoidea clade with either washakiines on Uintanius. These elements of tree topology remain fairly stable under different assumptions sets, but overall, tree topology is not robust. Previously divergent hypotheses regarding anthropoid relationships are attributable to the use of restricted data sets. This large data set enables the adapid-anthropoid hypothesis to be rejected, and unites Tarsius, Anthropoidea and Omomyiformes within a clade, Haplorhini. However, relationships among these three taxa cannot be convincingly resolved at present.

Animals↗
PubMed1998

The meaning and management of neuroleptic medication: a study of patients with a diagnosis of schizophrenia.

The meaning of medication and the way in which people use medicines has been the focus of a number of studies in recent years. However, there has been little attention directed to the meaning and management of neuroleptic medication by people who have received a diagnosis of schizophrenia. This topic is highly relevant to policy because of the central role given to neuroleptics in contemporary mental health and community care services. Using data from in-depth interviews with people with a diagnosis of schizophrenia we explore patients reasons for taking neuroleptics and the ways in which patients self-regulate their medication. The data suggest that the main utility of taking neuroleptic medication is to control specific symptoms and to gain personal control over managing symptoms. The costs of taking medication were side-effects which at times equalised or outweighed the positive gains of the neuroleptic medication. Patient accounts suggest that everyday medication practices are to a significant degree related to a policy context which stresses the need to survey and control the behaviour of people living in the community and the wider meaning and symbolic significance that schizophrenia has for patients in their everyday lives. For this reason, self regulatory action in this group of patients tends to be less evident and the threat of external social control greater than patients taking medication for other chronic conditions. The findings suggest the need to develop a collaborative patient-centred model of medication management for patients diagnosed with schizophrenia.

Adaptation, Psychological↗
PubMed1998

The meaning of patient satisfaction: an explanation of high reported levels.

The social policy background to the proliferation of patient satisfaction surveys is a desire for increased patient representation and participation. Within this context, it is assumed that satisfaction surveys embody patients' evaluations of services. However, as most surveys report high satisfaction levels, the interpretation of satisfaction as the outcome of an active evaluation has been called into question. The aim of this study is to identify whether and how service users evaluate services. This was made possible through unstructured in-depth interviews with users of mental health services and through more structured discussion around their responses on a patient satisfaction questionnaire (CSQ 18B) whose psychometric properties has been well documented. Twenty-nine people with current or recent contact with mental health services within the British National Health Service were interviewed. The data revealed that service users frequently described their experiences in positive or negative terms. However, the process by which these experiences were transformed into "evaluations" of the service was complex. Consequently, many expressions of "satisfaction" on the CSQ 18B hid a variety of reported negative experiences. An explanation for this lack of correspondence is outlined.

Bias↗