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Biomedical subjects

W Richardson

Publications and source records attributed to W Richardson.

At least 37 records · Page 2Linked to original sources
PubMed1994

The first t-test.

The data with which Student illustrated the application of his famous distribution are examined from a number of aspects. Central to the discussion is the within-patient clinical trial at Kalamazoo whose results were published by Cushny and Peebles and misquoted by Student and Fisher. This trial is discussed from historical, pharmacological and statistical perspectives. Student's and Fisher's analyses and a more modern analysis by Preece are considered as is Cushny's and Peebles's interpretation. Brief biographies of the five physicians involved in running the trial are presented.

Animals↗
PubMed1994

Sclerosing peritonitis.

Sclerosing peritonitis (SP) is an uncommon and devastating problem which involves the visceral and parietal peritoneal surfaces of the abdominal cavity. SP has been reported in association with peritoneal dialysis, with medications, and following peritonitis. No clear etiology or preventative treatment exists for this unusual problem. Herein, we report 3 cases with the unusual aspect of apparent progression of this fibrotic and sclerosing process after the termination of the peritoneal dialysis and successful renal transplantation. Each of these cases resulted in a mechanical small bowel obstruction secondary to a densely fibrosing and encasing peel of reactive connective tissue visibly different from the usual postoperative adhesions. Sclerosing peritonitis should be included in the differential diagnosis of a current peritoneal dialysis patient who exhibits signs of partial small bowel obstruction with a continual decrease in peritoneal clearance and/or successfully transplanted patients who had utilized peritoneal dialysis therapy in the past and now exhibit signs and symptoms of a mechanical small bowel obstruction.

Adult↗
PubMed1993

Synthesis of tumour necrosis factor-alpha and interferons by mononuclear cells from Theileria annulata-infected cattle.

Bovine macrophage-derived tumour necrosis factor-alpha/cachectin (TNF-alpha) was synthesized when peripheral blood mononuclear cells (PBMC) and purified adherent PBMC from naive and Theileria annulata-infected cattle were incubated in vitro with concanavalin A (Con-A) or bovine recombinant interferon gamma (Bo rIFN-gamma). TNF-alpha production was also induced when adherent PBMC were cultured with T. annulata macroschizont-infected cells. In contrast, non-adherent PBMC from sublethally infected cattle produced interferon (IFN) when incubated with Hu rIL-2, Con-A, phytohaemagglutinin (PHA) or T. annulata macroschizont-infected cells growing as cell lines in vitro. Whilst PBMC from lethally infected cattle spontaneously produced IFN-gamma during advanced stages of infection, the sera of such animals contained type 1 IFN (alpha/beta). IFN was also produced by T. annulata macroschizont-infected cell lines maintained in vitro. This work suggests that cytokines serve as crucial links between proliferating Theileira-infected cells and the characteristic clinical symptoms of tropical theileriosis.

Animals↗
PubMed1992

Tropical theileriosis in Bos taurus and Bos taurus cross Bos indicus calves: response to infection with graded doses of sporozoites of Theileria annulata.

This work extends basic knowledge of tropical theileriosis in taurine and crossbred cattle. Infection of Bos taurus and Bos taurus cross Bos indicus (Sahiwal) calves with graded doses of sporozoites of Theileria annulata (Hissar), an Indian stock of the parasite, showed the following to be dose dependent in both cattle types: the time to appearance and population size of macroschizonts, microschizonts and piroplasms, time and severity of pyrexia, anaemia manifested by erythrocyte counts and haematocrit. All infections were accompanied by a prompt and severe panleucopenia. This effect was dose related in both the taurine and the Sahiwal crossbred calves. Lymphocyte counts returned to preinfection levels in the blood of animals which recovered, but death from theileriosis was characteristically accompanied by a persistent and severe lymphocytopenia. Flow cytometry using monoclonal antibodies to bovine mononuclear cells was used to identify the lymphocyte subsets involved in lymphocytopenia. The outcome of infection was dose dependent in the crossbred calves but not in taurine calves. Although the results obtained did not differ qualitatively between the two cattle types, they provided some preliminary evidence for resistance to tropical theileriosis in Sahiwal crossbred calves.

Animals↗
PubMed1992

Cytokines inhibit the development of trophozoite-infected cells of Theileria annulata and Theileria parva but enhance the proliferation of macroschizont-infected cell lines.

The following bovine (Bo) and human (Hu) cytokines--Bo rTNF-a, Bo rIFN-g, Hu IFN-a, Hu rIL-1, Hu rIL-2--significantly inhibited the in vitro development of trophozoite-infected cells of three stocks of Theileria annulata and of Theileria parva (Muguga). However, none of these cytokines inhibited the proliferation of established T. annulata or T. parva macroschizont-infected cell lines. Indeed, Bo rTNF-a and Hu rIL-2 consistently enhanced the proliferation of macroschizont-infected cell lines of both species and the blastogenesis of uninfected lymphocytes in trophozoite-infected cultures. These results suggest that cytokines could help in resistance to challenge infections by preventing the further development of trophozoite-infected cells but provide no evidence that any of the above cytokines directly help to resolve primary infections by inhibiting the growth of macroschizont-infected cells. These findings also suggest that both TNF-a and IL-2 could play a role in the pathogenesis of Theileria infections by promoting the proliferation of macroschizont-infected cells and the associated lymphoid hyperplasia.

Animals↗
PubMed1992

Clinical improvement of the myopathy in eosinophilia-myalgia syndrome with steroids and rehabilitative therapy.

The authors report a case of eosinophilia-myalgia syndrome with a progressive neuromyopathy. Progressive weakness, myalgia, and dermatitis developed in the patient described after chronic ingestion of high-dose L-tryptophan for insomnia. Laboratory, electrophysiologic, and muscle biopsy results support the diagnosis of an inflammatory myopathy consistent with that of eosinophilia-myalgia syndrome. The patient's weakness led to wheelchair dependency. A review of the literature regarding this disorder shows inconsistent results with steroid and other modes of therapy. After a course of high-dose steroids with long-term tapering and vigorous inpatient and outpatient rehabilitation, the patient was able to walk and function independently within 2 months.

Adult↗
PubMed1991

Surgical management of metastatic renal carcinoma of the spine.

A total of 33 patients with renal cell carcinoma metastatic to the spine underwent spinal decompression over a 5-year period; 20 were operated on for neurologic dysfunction, and the remainder for pain alone. Surgery was performed anteriorly in 21, posteriorly in 9, and combined in 3 cases. The surgical approach was determined by the preoperative anatomic localization of the tumor. Of these patients 88% had fusions with instrumentation and polymethylmethacrylate; 88% of patients had partial or complete relief of pain; and 64% of bedridden patients subsequently were able to walk. Neurologic function improved in 60% of patients with a neurologic deficit; however, only 36% of incontinent patients regained bladder control. Survival averaged 8.0 +/- 1.5 months. Survival correlated with the degree of neurologic dysfunction and the presence of other known metastases. Recurrent cord compression developed in 49% of patients, usually at the same level; 9 of these 16 patients had repeat decompression, with similar operative results as the primary procedure in terms of pain and neurologic function. Blood loss was variable but often significant. Preoperative embolization appeared to be beneficial. Precise tumor localization preoperatively directing the surgical approach and better patient selection would likely improve results and decrease morbidity. Good palliation appeared to be achieved in regards to both pain relief and improved neurologic function.

Bone Cements↗
PubMed1989

Expression of an embryonic spicule matrix gene in calcified tissues of adult sea urchins.

The sea urchin spicule is composed of CaCO3 associated with an organic matrix containing at least 10 proteins. We have previously shown that one of these proteins, a 50-kDa glycoprotein (SM 50), is encoded by a gene which is only transcribed in cells of the micromere-mesenchyme lineage. In this report we examined RNA from five adult tissues: ovary, coelomocytes, intestine, tube feet, and spine for the presence of SM 50 transcripts and protein. Only RNA from cells of spine and tube feet hybridized to a SM 50-specific probe on Northern blots. These same two tissues undergo biomineralization and contain a protein which is immunologically related to the SM 50 protein. The restricted accumulation of SM 50 transcripts and protein suggests that the differentiation of biomineralizing mesenchyme cells in embryonic and adult tissue may utilize the same genetic program.

Animals↗
PubMed1988

Physical disability: the role of the physical scientist in the health service. A report of the Institute of Physical Sciences in Medicine.

The Report of the Royal College of Physicians on Physical Disability in 1986 and Beyond gives details of a Medical Disability Service to redress the present imbalance in the provisions for the physically disabled. An integral part of this service should be the provision of adequate scientific and technical resources, which could be established by making four or five new Medical Physics and Clinical Engineering appointments annually in each Region for the next ten years.

Biomedical Engineering↗
PubMed1988

Long-term performance of Tec vaporizers. Basis for a rational maintenance policy.

We reviewed the maintenance records of Tec vaporizers which had been in clinical use for up to 4 years. Tec 4s and Enfluratec 3s were found to be extremely reliable, but Fluotec 3s suffered progressively from mechanical and calibration problems. Their most recurrent fault was sticking valves caused probably by thymol crystallizing on the valve faces. This fault did not occur with Fluotec 4s, which are designed to prevent liquid agent reaching the valve surfaces. We found, in a study of the effects of thymol accumulation, that only occasional draining of a Fluotec vaporizer is required to keep thymol concentration below the level at which its output is reduced. We conclude that, if regular field calibration checks are carried out as a safety measure, the service interval for Tec vaporizers could be extended beyond Ohmeda's present recommendation of one year.

Anesthesia, Inhalation↗
PubMed1986

Congenital pupillary-iris-lens membrane with goniodysgenesis (a new entity).

We encountered two clinically similar but genetically unrelated cases of a disorder characterized by an unusual white pupillary-iris-lens membrane with extension to a prominent Schwalbe's line, the membranes were vascularized and their appearance changed over time. In both cases the abnormality was unilateral. Anomalous chamber angles were seen on gonioscopy. The clinical appearance is similar to a combination of iridogoniodysgenesis and pupillary membrane. However, our two cases are unique and fit into neither category. We postulate that this is a new entity consisting of an anomalous chamber angle and iris-lens membrane resulting from a localized iris (pupillary membrane), infarct with secondary neovascularization, during formation of the chamber angle.

Anterior Chamber↗
PubMed1986

Evaluation of keyed fillers on TEC vaporizers.

Single and dual port versions of the keyed fillers fitted to TEC4 and TEC3 vaporizers, respectively, were examined. The single port filler performed satisfactorily, provided that it was correctly used and properly maintained. Design deficiencies in the dual-port keyed filler were found which accounted for many of the problems described by users. The keyed bottle adaptor could be improved by an increase in its length and the provision of two openings into the outer tube at the bottle end.

Anesthesia, Inhalation↗