Biomedical subjects
B Williams
Publications and source records attributed to B Williams.
The Sophy valve and the el-Shafei shunt system for adult hydrocephalus.
A selected series of 22 adult patients with hydrocephalus were treated by a shunt system incorporating a variable pressure Sophy valve or by ventriculojugular shunting against the direction of blood flow using the El-Shafei system. One patient had insertion of two Sophy valves and an El-Shafei shunt. Patient selection was reserved to those with hydrocephalus thought to be at high risk when shunted with systems containing a conventional unipressure valve. None of the eight patients who had ventriculojugular shunting by the El-Shafei method demonstrated any notable clinical or radiological improvement subsequent to shunt insertion. Of the 16 Sophy devices inserted only seven produced a satisfactory result. The current evaluation of shunt malfunction could be improved by support for a national register.
Angiotensin II increases vascular permeability factor gene expression by human vascular smooth muscle cells.
Angiotensin II (Ang II) has been implicated in the pathogenesis of the vascular injury associated with hypertension and diabetes mellitus. Increased vascular permeability is an important early manifestation of endothelial dysfunction and the pathogenesis of atherosclerosis. How Ang II contributes to endothelial dysfunction and promotes an increase in vascular permeability is unknown but is classically attributed to its pressor actions. We demonstrate that human vascular smooth muscle cells express abundant mRNA for vascular permeability/endothelial growth factor. Vascular permeability factor is a 34- to 42-kD glycoprotein that markedly increases vascular endothelial permeability and is a potent endothelial mitogen. Ang II potently induced a concentration-dependent (maximal, 10(-7) mol/L) and time-dependent increase in vascular permeability factor mRNA expression by human vascular smooth muscle cells that was maximal after 3 hours and diminished by 24 hours. Ang II-induced vascular permeability factor mRNA expression by human vascular smooth muscle cells was inhibited by the specific Ang II receptor antagonist losartan (DuP 753), confirming that this is an Ang II receptor subtype 1-mediated event. These results describe a new action of Ang II on human vascular smooth muscle, notably the induction of vascular permeability factor mRNA expression. The wide spectrum and potent activity of vascular permeability factor suggest a novel mechanism whereby Ang II could locally and directly influence the permeability, growth, and function of the vascular endothelium independent of changes in hemodynamics.
Chronic generalized obliterative arteriopathy in cattle: a sequel to sheep-associated malignant catarrhal fever.
Malignant catarrhal fever (MCF) in cattle is generally associated with a short clinical course and a high case fatality rate (90-95%). The lesions in cattle that survive acute MCF for a prolonged period or appear to recover have not been documented. In a naturally occurring outbreak of MCF in a herd of beef cattle in Wyoming, 7 of 84 yearling heifers (8.3% of replacement herd) and 2 of 230 cows (0.9% of cow herd) developed clinical signs of pyrexia, mucopurulent discharge, bilateral keratitis, and weight loss following contact with ewes that had lambed 34-62 days earlier. Six of 9 affected cattle were examined postmortem following clinical signs (CS) that developed 2-150 days earlier. Three cattle with CS for < or = 39 days had lesions of regional lymphadenopathy and widespread severe segmental lymphoid arteritis-phlebitis that were typical of acute MCF, and proliferative intimal lesions were present in a small proportion of arteries at days 20 and 39 of CS. By contrast, 3 cattle that survived to 90, 105, and 150 days after clinical onset had distinctive arterial lesions in multiple organs, characterized by proliferative concentric fibrointimal plaques, disrupted inner elastic lamina, focally atrophic tunica media, and vasculitis of variable severity. Immunohistochemical and ultrastructural examination of intimal plaques identified the predominant cellular component to be smooth muscle cells with a contractile phenotype. No viral structures were seen. Serologic studies, using a competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA) that detects antibody to an epitope broadly conserved among isolates of the MCF virus, found that 2 chronically affected cattle were serologically positive between days 42 and 100 of CS, with seroconversion in 1 animal between days 52 and 73 of CS. Seroprevalence was 7.9% in the 76 remaining healthy animals of the replacement heifer herd and 40% (75% in adult sheep and 4% in lambs) in the in-contact sheep flock 77 days after onset of CS in the index case. This episode suggests that, in addition to the common and well recognized acute form of MCF in cattle, this viral infection encompasses a disease spectrum that includes chronic disease and partial to "complete" clinical recovery, and in recovered animals chronic obliterative arteriopathy is the preeminent lesion.
Patient satisfaction in mental health care. Evaluating an evaluative method.
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Friends in passing: social interaction at an adult day care center.
This study explores the social interactions and friendships that exist among cognitively impaired adult day care participants. A five month participant observation of an adult day care center was conducted, involving fifty-three clients ranging in age from sixty-six to ninety-three. Findings indicate that the clients engage in a variety of social interactions and friendships, enabling them to maintain a sense of self as well as to adjust to the norms of the group. Specific areas to be discussed are: general socializing, enduring friendships, helping relationships and client integration. A descriptive approach such as this provides the opportunity to examine the complexity of social interactions, including the positive relationships available to the cognitively impaired elderly.
A critical appraisal of drainage in syringomyelia.
The use of drains in the treatment of syringomyelia has a simple and immediate appeal and has been practiced widely since the report of Abbe and Coley over 100 years ago. Good short-term results have been claimed in the past, but long-term outcome is largely unknown. An experience in Birmingham, England is reviewed in which 73 patients who had had some form of syrinx drainage procedure performed were subsequently followed up. In these cases, a total of 56 syringopleural and 14 syringosubarachnoid shunts had been inserted. Ten years after the operations, only 53.5% and 50% of the patients, respectively, continued to remain clinically stable. A 15.7% complication rate was recorded, including fatal hemorrhage, infection, and displacement of the drain from the pleural and syrinx cavities. At second operation or necropsy, at least 5% of shunts were discovered to be blocked. The effect of other drainage procedures that do not use artificial tubing, such as syringotomy and terminal ventriculostomy, was analyzed but found not to offer any substantial benefit. These results indicate that drainage procedures are not an effective solution to remedying the progressive, destructive nature of syringomyelia. It is suggested that, rather than attempting to drain the syrinx cavity, disabling the filling mechanism of the syrinx is more appropriate. Most forms of syringomyelia have a blockage at the level of the foramen magnum or in the subarachnoid space of the spine. Surgical measures that aim to reconstruct the continuity of the subarachnoid space at the site of the block are strongly recommended. Lowering the overall pressure of the cerebrospinal fluid is advocated when reestablishment of the pathways proves impossible. Syrinx drainage as an adjuvant to more physiological surgery may have a place in the treatment of syringomyelia. If two procedures are done at the same time, however, it is difficult to ascribe with certainty a success or failure, and it is suggested that the drainage procedure be reserved for a later attempt if the elective first operation fails.
Recovery of mitochondrial and nuclear DNA from archived allozyme samples.
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Medicine and health care: marital status uncertain.
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Insulin resistance: the shape of things to come.
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Doctors and homosexuality. Homosexuals deserve better from doctors.
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Rural access line: a tool for improving communication between rural GPs and hospital specialists in Western Australia.
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Valvular factors in hydrocephalus.
Various ways in which blockage of cerebrospinal fluid pathways can lead to increasing intracranial pressure and enlargement of the ventricles are discussed. The necessity of understanding the valvular morphology involved is stressed as fundamental to the search for optimal treatment methods.
An updated review of the clinical development of coumarin (1,2-benzopyrone) and 7-hydroxycoumarin.
Several authors have demonstrated that coumarin (1,2-benzopyrone) in combination with cimetidine can produce objective antitumor responses in some patients with advanced renal cell carcinoma. The purpose of this report is to review the clinical development of coumarin, with or without cimetidine, with special reference to renal cell carcinoma (RCC). Previously unpublished data concerning the survival of a population of patients with RCC, who were treated on a phase I trial of coumarin and cimetidine, are presented. The rationale and study design of an active randomized, double-blinded, placebo-controlled trial of coumarin for RCC are discussed. A progress report is given for an ongoing phase I trial of oral 7-hydroxycoumarin, the major human metabolite of coumarin.
Patient satisfaction: a valid concept?
Over the past 10 yr consumer satisfaction has gained widespread recognition as a measure of quality in many public sector services. This has become manifest in the NHS in the call by the 1983 NHS Management inquiry to ascertain how well the service is being delivered at local level by obtaining the experience and perceptions of patients and the community. Patient satisfaction is now deemed an important outcome measure for health services; however, this professed utility rests on a number of implicit assumptions about the nature and meaning of expressions of 'satisfaction'. Through a review of past research findings this paper suggests that patients may have a complex set of important and relevant beliefs which cannot be embodied in terms of expressions of satisfaction. Consequently, many satisfaction surveys provide only an illusion of consumerism producing results which tend only to endorse the status quo. For service providers to meaningfully ascertain the experience and perceptions of patients and the community then research must first be conducted to identify the ways and terms in which those patients perceive and evaluate that service.
A physical map and candidate genes in the BRCA1 region on chromosome 17q12-21.
We have constructed a physical map of a 4 cM region on chromosome 17q12-21 that contains the hereditary breast and ovarian cancer gene BRCA1. The map comprises a contig of 137 overlapping yeast artificial chromosomes and P1 clones, onto which we have placed 112 PCR markers. We have localized more than 20 genes on this map, ten of which had not been mapped to the region previously, and have isolated 30 cDNA clones representing partial sequences of as yet unidentified genes. Two genes that lie within a narrow region defined by meiotic breakpoints in BRCA1 patients have been sequenced in breast cancer patients without revealing any deleterious mutations. These new reagents should facilitate the identification of BRCA1.
Comparison of services among different types of home health agencies.
Past and proposed public policy reforms in home care have presumed that similar services are provided by different types (e.g., public, proprietary) of home health agencies under a uniform benefit. To examine this presumption, the author used Medicare billing data and interview information for a nationally representative sample of 921 home health patients from the 1984 National Long Term Care Survey, supplemented with data on agency type from the Health Care Financing Administration. In multivariate linear regression models that included patient demographics, marital status, insurance status, living arrangement, urban/rural location, informal support, and functional status, patients of public home health agencies and Visiting Nurse Associations (VNAs) had lower total charges and fewer visits per episode of enrollment than patients of hospital-based, private nonprofit, or proprietary agencies. Public home health agency patients had the lowest and proprietary agency patients the highest number of visits per week of enrollment. Model R2 ranged from 0.13 to 0.22. These results indicate that, for example, similar patients could be expected to incur nearly four times the total charges, and receive three times the total visits and twice the number of visits per week at proprietary as compared with public home health agencies. Patients enrolled in home health agencies with greater incentives to generate revenue incurred more charges, and received more total and more frequent visits than patients enrolled in agencies that can cross-subsidize services. The amount of services and total cost of current proposals to expand the provision of supportive home care services may be strongly influenced by the implicit mix of provider types.
An unusual vascular hamartoma on the gingiva of an 11-year-old boy.
A case is reported of an unusual vascular lesion on the gingiva of an 11-year-old boy which clinically and histopathologically did not fit well into any current classification of vascular lesions. The lesion presented as a firm nodular swelling of the buccal and lingual gingiva which had been present for 9 years. The term endovascular papillary haemangioma is suggested. Histopathologically it had features in common with a number of benign vascular lesions, as well as with some more sinister locally-aggressive vascular tumours and angiosarcomas. It is stressed that, although some of these lesions may display features suggestive of malignancy, care should be exercised when making this diagnosis, as in recent years there has been an increase in the recognition and characterization of benign vascular lesions which exhibit unusual features.