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R Bell

Publications and source records attributed to R Bell.

At least 199 records · Page 11Linked to original sources
PubMed1993

The evaluation of the isolated perfused liver as a model for the assessment of liver preservation.

An ex vivo isolated perfused porcine liver model was tested to assess its suitability for rapid, reliable and relatively cheap testing of organ preservation solutions for liver transplantation. The model consists of a machine driven recirculating system incorporating an organ chamber, blood pump and membrane oxygenator. Autologous blood was used for perfusion for a period of 2 h at a temperature of 37 degrees C. The model was tested with five groups of livers which had sustained varying degrees of injury ranging from minimally damaged to those known to be incapable of sustaining life when used for liver transplantation. The groups of livers were: (i) controls; (ii) preserved in University of Wisconsin solution (UW) for 6 h; (iii) preserved in an albumin-based extracellular fluid (ALB) for 6 h; (iv) preserved in UW for 18 h; and (v) preserved in ALB for 18 h. Bile production was found to be a reliable parameter of preservation damage. Changes in perfusate levels of aspartate aminotransferase, potassium, glucose and calcium also occurred in relationship to preservation damage. In contrast, weight gain of the liver, sequestration of the white cells and platelets in the liver, urea production and oxygen consumption were unreliable predictors of liver damage. Histology of biopsy specimens revealed apparently well preserved livers in all cases after preservation but before perfusion, but serious abnormalities after perfusion in long preserved livers, with features in these suggestive of damage to the sinusoidal endothelium. We believe that the model is a worthwhile adjunct to research into liver preservation.

Adenosine↗
PubMed1993

Clinical features and management of recurrent balanitis; association with atopy and genital washing.

OBJECTIVE: To evaluate clinical features and diagnostic investigations in patients with recurrent or unresponsive balanitis in order to institute rational management. DESIGN: Forty-three patients presenting to a genitourinary medicine clinic with recurrent or persistent balanitis were studied. All patients were asked whether they had a history of atopic illness and about their practice of genital washing. All patients were investigated by taking a swab specimen from the preputial area for bacterial and viral culture and 30 underwent biopsy of the affected skin. Follow-up was between three and six months. SETTING: Outpatient genitourinary medicine clinic, St Mary's Hospital, London, UK. RESULTS: In 31 (72%) of the patients a diagnosis of irritant dermatitis was made. In comparison with the remaining patients, they had a greater lifetime incidence of atopic illness and more frequent daily genital washing with soap. For 28 (90%) of these patients, use of emollient creams and restriction of soap washing alone controlled symptoms satisfactorily. For the remaining 12 patients, a variety of diagnoses were made. Biopsy proved a well tolerated and diagnostic investigation, but the isolation of microbial pathogens from preputial swabs was irrelevant to management. CONCLUSION: A history of atopic illness and of the practice of penile washing are important aspects in the evaluation of patients with recurrent balanitis. Biopsy is an important investigation in the condition when it does not seem to be caused by irritant dermatitis.

Adult↗
PubMed1993

Laying the groundwork for a smooth transition to TQM.

The increasingly popular corporate philosophy of total quality management (TQM) can (and should) be applied to the healthcare industry--as structured and bureaucratic a system as can be found. Yet one does not begin by running, but by learning how to walk. So, too, with TQM. In this article, the author makes several suggestions that will enable healthcare managers to take those first few steps toward better quality service and patient care.

Attitude of Health Personnel↗
PubMed1993

The febrile child.

Explore the source record for details and available documents.

Bacterial Infections↗
PubMed1993

Percutaneously placed dual-lumen silicone catheters for long-term hemodialysis.

Dual-lumen Dacron-cuffed silicone hemodialysis catheters placed percutaneously under fluoroscopic control have been used by us in 200 patients since July 1986. A total of 246 catheters were placed in 4 years, of which 172 were for long-term hemodialysis in place of prosthetic tube bridge arteriovenous shunts. One-year catheter survival estimate by Kaplan-Meier life table was 57 per cent, and mean survival estimate was 16.3 months. There were a combined 76 patient years of catheter experience, with some catheters lasting as long as 2 1/2 years. Catheter thrombosis occurred in 92 catheters, but 83 per cent of cases responded to thrombolytic therapy. There were exit site infections with thirty-nine catheters, but 90 per cent resolved with antibiotic therapy. Twenty-two bacteremias occurred with 19 catheters, which resulted in 15 catheter removals. The remaining seven cases of bacteremia responded to antibiotic therapy without catheter removal. Subclavian vein or superior vena cava thrombosis has not been a problem. Silicone catheters are a practical alternative to prosthetic tube bridge arteriovenous shunts for long-term hemodialysis.

Adolescent↗
PubMed1993

Soft tissue sarcomas: a plea for proper management.

Although soft tissue sarcomas are relatively uncommon, they often occur in young patients and if properly treated are often curable. Unfortunately, inappropriate approaches to biopsy before adequate staging may compromise a successful outcome. The roles of diagnostic imaging (particularly magnetic resonance imaging) in adequate preoperative evaluation and staging and the fundamental principles of surgical management are discussed.

Adolescent↗
PubMed1992

Inhibition of metastatic behavior of murine osteosarcoma by hypophysectomy.

BACKGROUND: We recently reported that human osteogenic sarcoma cells are mitogenically responsive in tissue culture to insulin-like growth factor I (IGF-I), a mitogen important in the regulation of cellular proliferation of many tissues, including bone. PURPOSE: The present study was designed to determine whether these in vitro observations could be extended to an in vivo experimental system and whether reduction of IGF-I levels by hypophysectomy could inhibit the aggressive metastatic behavior of osteosarcoma. METHODS: We used standard competitive binding and affinity-labeling techniques to characterize the IGF-I-binding sites of MGH-OGS, a model of human osteosarcoma. Radioimmunoassay of serum, preprocessed to remove IGF-binding proteins, was used to quantitate IGF-I levels. In vitro proliferative response of MGH-OGS cells to IGF-I and other pituitary-dependent factors was determined by thymidine-incorporation experiments. In vivo growth of the neoplasm in 12 hypophysectomized C3H mice and in 14 control C3H mice was determined by serial measurements of implanted tumors and by gross and microscopic examination of the lungs for metastases. RESULTS: MGH-OGS exhibited specific binding sites for 1.39 pmol IGF-I per milligram MGH-OGS cellular membrane protein, a concentration similar to that which we previously reported for human osteosarcoma. In tissue culture, MGH-OGS exhibited mitogenic response to IGF-I (P less than .01) but not to other pituitary-dependent factors. Hypophysectomy reduced levels of circulating IGF-I to 15% of control, significantly inhibited local growth of MGH-OGS tumors (increased time for growth to 1 cm3 from 49 to 84 days, P less than .001), and profoundly inhibited metastatic behavior (decrease in mean number of metastases per host from 16 to less than one; P less than .001). CONCLUSIONS: This study is the first to document the profound inhibitory effect of hypophysectomy on the metastatic behavior of an experimental sarcoma. We conclude that the metastatic behavior exhibited by MGH-OGS osteosarcoma is dependent on pituitary factors, and we suggest that the inhibitory effects of hypophysectomy are related, at least in part, to the reduction of IGF-I levels.

Animals↗
PubMed1992

Hippocampal NCAM180 transiently increases sialylation during the acquisition and consolidation of a passive avoidance response in the adult rat.

Synaptic connectivity change is a consistent anatomical feature of memory formation and the possibility that this is mediated by a replay of neurodevelopmental events has been investigated by measuring change in neural cell adhesion molecule sialylation state during the acquisition and consolidation of a passive avoidance response in the adult rat. The avoidance response was always generated after two to three trials and the animals remained on the platform for the criterion time of 5 min. In all cases training was complete within 5-8 min. Change in sialylation state was monitored following intraventricular infusion of the 3H-ManNAc precursor at 4 hr prior to the reference point. No task-specific change in general glycoconjugate sialylation was apparent in hippocampal P2 pellets at increasing times following training. Increased sialylation state was observed only in neural cell adhesion molecule (NCAM) immunoprecipitates of hippocampal membrane fractions at 12 and 24 hr after training. Change in hippocampal sialylation state could not be attributed to an increased accumulation of NCAM as detected by an immunoabsorbent assay. Immunoblotting of antibody precipitated NCAM demonstrated the 3H-ManNAc to be incorporated into the synapse-specific, 180 kDa isoform of NCAM and a novel 210 kDa isoform. Immunoprecipitation and immunoblotting procedures with an antibody specific for a2-8-polysialic acid showed the 180 and 210 kDa isoforms to be polysialylated. The role of NCAM180 sialylation as a mechanism for synapse selection in information storage is discussed.

Animals↗
PubMed1992

Intraventricular infusions of anti-neural cell adhesion molecules in a discrete posttraining period impair consolidation of a passive avoidance response in the rat.

Intraventricular infusions of anti-neural cell adhesion molecule (anti-NCAM) are demonstrated to inhibit consolidation of a passive avoidance response when administered in the 6-8 h posttraining period. Anti-NCAM was ineffective when administered during training or at any other time up to 10 h thereafter, and no amnesic effects were observed with absorbed anti-NCAM or anti-neurofilament protein. Amnesia was observed only at the 48-h recall time, and this could not be attributed to poor antibody penetration or a prolonged residence time, as studies with 125I-labelled anti-NCAM in trained animals demonstrated a rapid accumulation into all brain regions, and this was marked in the olfactory bulb and hippocampus, areas showing an inherent and paradigm-specific increase in NCAM sialylation state, respectively. The lack of an amnesic action at the 24-h recall time is attributed to anti-NCAM-impaired synapse structuring becoming apparent following the paradigm-specific increases in NCAM sialylation state.

Amnesia↗
PubMed1992

Low birthweight and socioeconomic status, Victoria 1982 to 1986.

The aim of this study was to evaluate the association between the incidence of low birthweight and socioeconomic status, in particular whether the relationship was different for very low birthweight (less than 1500 g) and moderately low birthweight (1500 to 2499 g). The study population was births from 1982 to 1986 to women resident in Victoria (300,704). Data on socioeconomic status were derived from an indicator developed by the Australian Bureau of Statistics from the 1981 census and applied to postcodes. Using the rates of very low birthweight and moderately low birthweight in the highest socioeconomic status decile as the reference value we found that the relative risk for very low birthweight was significantly raised in only the lowest socioeconomic status decile (relative risk = 1.29, 95% confidence interval (CI) 1.17 to 1.42). The relative risk for moderately low birthweight was increased in the two lowest deciles: 1.19 (CI 1.12 to 1.26) and 1.09 (CI 1.01 to 1.17) respectively. Women not married at the time of the birth had a higher rate of low birthweight and were more likely to live in the lower socioeconomic status postcode areas. The relationships between very low birthweight, moderately low birthweight and socioeconomic status were attenuated but still significant when this factor was taken into account. Differences in low birthweight by socioeconomic status decile were not apparent for nonsmoking women. The relationship between smoking and low birthweight was different in the two lowest socioeconomic status deciles: the relative risk of low birthweight in smokers was 2.60 (CI 1.73 to 3.91) compared with a relative risk of 1.64 (CI 1.33 to 2.03) in deciles 3 to 10.

Australia↗
PubMed1992

All-trans retinoic acid in the treatment of acute promyelocytic leukaemia.

All-trans-retinoic acid (ATRA) is known to induce differentiation of promyelocytes in vitro and also to induce remission of acute promyelocytic leukaemia in vivo. We treated 11 patients with poor prognosis acute promyelocytic leukaemia (APL) with ATRA and obtained seven complete and one partial remission. Remissions took one to three months to achieve and were associated with adverse effects including dry skin and bone pain. In eight patients the white cell count rose above 20 x 10(9)/L within the first ten days of retinoic acid treatment and this was associated with the development of pulmonary leukostasis in three patients which was fatal in one. Another two patients died of intracranial haemorrhage also within the first ten days. ATRA is a promising new agent in the induction therapy of this particular category of acute leukaemia.

Adult↗
PubMed1991

T-cell receptor V beta gene expression differs in tumor-infiltrating lymphocytes within primary and metastatic melanoma.

Expression of T-cell receptor (TCR) gene rearrangements in tumor-infiltrating lymphocytes (TILs) within primary and metastatic melanoma specimens was studied. In order to analyze TCR gene transcription in TILs within these tissues, we analyzed reverse transcribed complementary DNA from mRNA directly from tissues using the polymerase chain reaction. The polymerase chain reaction-amplified products were confirmed by dot or Southern blot hybridization with C alpha or C beta oligoprobes. First, we investigated the diversity of TCR V alpha and V beta gene usage in human malignant melanoma patients with multiple metastasis. We found in one patient, bearing multiple skin lesions, that the patterns of TCR V alpha and V beta repertoires in different sites of the skin (leg and chest wall) were almost the same. However, in another patient with skin and brain melanomas, different TCR repertoires were presented. Next, we examined the usage of murine TCR V beta genes in TILs within the primary and metastatic sites (liver, lung, and brain) of C57BL/6 mice bearing B16-F10 murine melanoma. The population of TILs in each primary and metastatic site expressed from one to four TCR V beta genes. In each metastatic site, the profile of TCR V beta gene expression was different. A different TCR V beta usage in TILs distributed within metastases of various organs may reflect differences in tumor antigenicity at these sites or may be due to differential homing patterns to these tumors.

Animals↗