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Biomedical subjects

R Bell

Publications and source records attributed to R Bell.

At least 109 records · Page 6Linked to original sources

Hypothermic ischaemia of the liver: a re-perfusion phenomenon.

BACKGROUND: The effects of hypothermic injury to the liver were investigated on an isolated perfusion circuit by comparing porcine livers with varying degrees of preservation injury. METHODS: A group of unstored livers (n = 5) were compared to livers stored in University of Wisconsin (UW) solution for 18 h (n = 5), and a group of livers stored in Hartmann's solution for 18 h (n = 5). RESULTS: We observed that the degree of platelet sequestration was directly related to the severity of the preservation injury. After 2 h of isolated liver perfusion, the perfusate platelet count fell from 148 +/- 14 x 10(9)/L to 84 +/- 13 x 10(9)/L for control livers. In comparison for livers stored in UW solution, the platelet count fell from 173 +/- 43 x 10(9)/L to 61 +/- 14 x 10(9)/L representing a 64.8% fall, while for those stored in Hartmann's solution, an even more profound fall from 152 +/- 36 x 10(9)/L to 19 +/- 9 x 10(9)/L (87.5% fall) was observed. The difference between the UW-stored and Hartmann's-stored livers was significant (P < 0.05). However, using this model, the degree of leukocyte sequestration did not differentiate the groups. Both histological and ultrastructural examination of liver biopsies taken immediately following revascularization demonstrated that for mild degrees of preservation injury following hypothermic storage, changes occur to the sinusoidal lining cells well before changes to the parenchymal elements. CONCLUSIONS: These findings substantiate the hypothesis that the primary injury associated with hypothermia involves the sinusoidal lining cells (non-parenchymal elements), that it is predominantly a reperfusion phenomenon and that efforts at improving preservation should therefore be targeted primarily at these cells and not the hepatocytes.

Adenosine↗

Charting patient satisfaction.

The importance of maintaining high levels of patient satisfaction has been well researched and thoroughly documented. Patient satisfaction can be measured, changed, controlled, and managed effectively to aid in improvement quality. Nevertheless, little research has been conducted to determine how patient satisfaction affects quality or how satisfaction strategies affect patients' perceptions. The authors of this study view patient satisfaction as a value-added component. They present a statistical process control-chart method that can help implement and evaluate a CQI strategy for improving patient satisfaction. The study illustrates how to measure patient satisfaction, create control charts, interpret the results, and develop administrative applications aimed at fulfilling a CQI strategy.

Data Collection↗

The Erlangen Hospital Communication Hub: migration from proprietary to standardised communication.

The Erlangen communication hub allows medical subsystems to exchange data by two completely different methods. Since 1995 a communication data base, which is implemented using the relational data base system ADABAS D, contains data from the most important hospital systems. This data can be accessed by other medical systems. Thus, the communication data base allows subsystems which do not have a standardised interface to implement proprietary system interconnections via access based on SQL. The capabilities of this interconnection are dependent on both the implementation and the data which is made available by the communication data base. This contains mainly basic patient data and the results of tests performed by various laboratory systems. In addition to this proprietary communication system we have since the end of 1996 a communication server which can also handle standardised message formats such as HL7, EDIFACT, DICOM3. Future subsystems which possess standard interfaces will be connected via this server. The connection of the patient management system IS-H and the central laboratory system to the database has been proceeding since the beginning of 1997.

Computer Communication Networks↗

Intra-abdominal fluid collections after liver transplantation.

Fluid collections are commonly seen following orthotopic liver transplantation. The majority of these collections are not infected and resolve spontaneously. However, infected collections are associated with significant morbidity and mortality and usually require drainage. Clinical signs of infection are frequently masked following transplantation due to immunosuppression. Intrahepatic collections usually represent abscesses or bilomas and invariably require intervention. Altered anatomical relationships result in signs that frequently help to differentiate these from loculated fluid within hepatic fissures. Other imaging features indicating infection include the presence of gas where none was seen previously, the development of a discrete wall and changes in the surrounding liver.

Ascites↗

Correlates of college student marijuana use: results of a US National Survey.

This study examines which personal student background and college characteristics are associated with marijuana use. A self-administered survey was mailed to a national representative sample of 17592 students at 140 American colleges. One of four (24.8%) students reported using marijuana within the past year. Rates of use among the colleges ranged from zero per cent at the lowest use schools to 54% at the highest use schools. Multiple regression models, constructed to determine the college and student characteristics predicting marijuana use, suggest that use was higher among students at non-commuter colleges and at colleges with pubs on campus. Student characteristics associated with marijuana use included being single, white, spending more time at parties and socializing with friends, and less time studying. Marijuana use was higher among students who participate in other high risk behaviors such as binge drinking, cigarette smoking and having multiple sexual partners, and among students who perceived parties as important, and religion and community service as not important. The study points to the social nature of drug use in college, and demonstrates that this behavior is of continuing concern for public health.

Adolescent↗

Generation of an integrated transcription map of the BRCA2 region on chromosome 13q12-q13.

An integrated approach involving physical mapping, identification of transcribed sequences, and computational analysis of genomic sequence was used to generate a detailed transcription map of the 1. 0-Mb region containing the breast cancer susceptibility locus BRCA2 on chromosome 13q12-q13. This region is included in the genetic interval bounded by D13S1444 and D13S310. Retrieved sequences from exon amplification or hybrid selection procedures were grouped into physical intervals and subsequently grouped into transcription units by clone overlap. Overlap was established by direct hybridization, cDNA library screening, PCR cDNA linking (island hopping), and/or sequence alignment. Extensive genomic sequencing was performed in an effort to understand transcription unit organization. In total, approximately 500 kb of genomic sequence was completed. The transcription units were further characterized by hybridization to RNA from a series of human tissues. Evidence for seven genes, two putative pseudogenes, and nine additional putative transcription units was obtained. One of the transcription units was recently identified as BRCA2 but all others are novel genes of unknown function as only limited alignment to sequences in public databases was observed. One large gene with a transcript size of 10.7 kb showed significant similarity to a gene predicted by the Caenorhabditis elegans genome and the Saccharomyces cerevisiae genome sequencing efforts, while another contained a motif sequence similar to the human 2',3' cyclic nucleotide 3' phosphodiesterase gene. Several retrieved transcribed sequences were not aligned into transcription units because no corresponding cDNAs were obtained when screening libraries or because of a lack of definitive evidence for splicing signals or putative coding sequence based on computational analysis. However, the presence of additional genes in the BRCA2 interval is suggested as groups of putative exons and hybrid selected clones that were transcribed in consistent orientations could be localized to common physical intervals.

BRCA2 Protein↗

Local intestinal immune responses to infections with Trichinella spiralis. Real-time, continuous assay of cytokines in the intestinal (afferent) and efferent thoracic duct lymph of rats.

Levels of IL-4, IL-5, TNF-alpha, and IFN-gamma were quantitated in the intestinal (afferent) and efferent thoracic duct lymph of rats during the course (0 to 289 h) of an infection with Trichinella spiralis. Intestinal lymph was collected by cannulating thoracic ducts of mesenteric lymphadenectomized animals. These studies showed that cytokines typical of a Th2 type (IL-4 and IL-5) and a Th1 type (IFN-gamma) were simultaneously detected in the intestinal lymph during the first 8 days after infection. Worm expulsion (day 11 to 12) was associated with increased levels of IL-4 and IL-5 in the intestinal lymph. IL-5 levels rose as early as 15 to 20 h and remained elevated throughout the infection. IL-4 activity appeared in intestinal lymph 60 h after infection and reached peak levels during worm expulsion. Despite the predominantly Th2 nature of cytokine response, IFN-gamma levels showed several cycles of high and low production during the course of infection. A comparison of cytokine levels between intestinal and efferent lymph values showed no significant differences in IL-4 or IL-5 levels suggesting no contribution by the mesenteric node to efferent lymph. However, IFN-gamma and TNF-alpha levels were lower in efferent lymph compared with intestinal lymph suggesting mesenteric node consumption. Adoptive transfer experiments showed that protective CD4+CD45RC- cells primed the gut for a more rapid TH2-type response that was faster than in a primary infection. In contrast, adoptive transfer of CD4+CD45RC+ cells primed the gut for a more rapid Th1-type(IFN-gamma) response. These studies demonstrate a novel method for measuring real-time changes in cytokine levels in the gut during the course of an active infection.

Animals↗

Efficacy of pamidronate in reducing skeletal events in patients with advanced multiple myeloma. Myeloma Aredia Study Group.

BACKGROUND: Skeletal complications are a major clinical manifestation of multiple myeloma. These complications are caused by soluble factors that stimulate osteoclasts to resorb bone. Bisphosphonates such as pamidronate inhibit osteoclastic activity and reduce bone resorption. METHODS: Patients with stage III multiple myeloma and at least one lytic lesion received either placebo or pamidronate (90 mg) as a four-hour intravenous infusion given every four weeks for nine cycles in addition to antimyeloma therapy. The patients were stratified according to whether they were receiving first-line (stratum 1) or second-line (stratum 2) antimyeloma chemotherapy at entry into the study. Skeletal events (pathologic fracture, irradiation of or surgery on bone, and spinal cord compression), hypercalcemia (symptoms or a serum calcium concentration > or = 12 mg per deciliter [3.0 mmol per liter]), bone pain, analgesic-drug use, performance status, and quality of life were assessed monthly. RESULTS: Among 392 treated patients, the efficacy of treatment could be evaluated in 196 who received pamidronate and 181 who received placebo. The proportion of patients who had any skeletal events was significantly lower in the pamidronate group (24 percent) than in the placebo group (41 percent, P < 0.001), and the reduction was evident in both stratum 1 (P = 0.04) and stratum 2 (P = 0.004). The patients who received pamidronate had significant decreases in bone pain and no deterioration in performance status and quality of life. Pamidronate was tolerated well. CONCLUSIONS: Monthly infusions of pamidronate provide significant protection against skeletal complications and improve the quality of life of patients with stage III multiple myeloma.

Aged↗

Effects of the 5-HT1A antagonist (+)-WAY-100135 on murine social and agonistic behavior.

Compounds previously identified as 5-HT1A antagonists have subsequently been demonstrated to possess partial agonistic properties in models assessing somatodendritic autoreceptor function. This study examined the influences of (+)-WAY-100135, claimed to be the first selective 5-HT1A antagonist, on offensive behaviour in male mice. Employing a resident-intruder paradigm, administration of (+)-WAY-100135 (1.0-10.0 mg/kg s.c.) enhanced elements of resident offensive behaviour at 2.5 and 5.0 mg/kg but reduced such behaviour at 10.0 mg/kg. In comparison, resident defensive postures remained unchanged except for a significant increase in defensive sideways behaviour at 10.0 mg/kg. These effects were accompanied by reduced rearing behaviour across the dose range tested. Attend/approach behaviour was significantly reduced at the lowest, but increased at the highest, doses tested. Such results may reflect response competition rather than concomitant motor impairment. Given the dynamic behavioural interactions occurring in this paradigm, the increased offensive behaviour of the resident mice leads to enhanced defence and counter-attack by the intruder conspecifics. The results are discussed with reference to the current literature concerning the behavioural effects of other 5-HT1A antagonists.

Agonistic Behavior↗

Soft tissue sarcoma of the extremity. Limb salvage after failure of combined conservative therapy.

PURPOSE: To assess the results of salvage therapy using surgery alone or surgery and re-irradiation for patients with locally recurrent extremity soft tissue sarcoma (STS) following conservative surgery and radiotherapy. MATERIALS AND METHODS: 25 patients with locally recurrent STS after conservative surgery and irradiation were assessed between 1990 and 1995. Two patients with concurrent systemic relapse were treated palliatively. Seven patients were not candidates for conservative re-excision and underwent amputation, 11 patients underwent conservative resection without irradiation. Seven of these patients relapsed, and five went on to receive combined conservative surgery and re-irradiation. A further five patients initially received combined retreatment, for a total of ten patients treated with combined conservative surgery and re-irradiation. Six of these ten patients were treated with brachytherapy alone, one with brachytherapy and external beam therapy, and three with external beam therapy alone. The median retreatment dose was 49.5 Gy (range 35-65 Gy), and the median cumulative soft tissue dose was 100 Gy (range 93-120 Gy). RESULTS: The median follow-up from the most recent treatment is 24 months (range 7-42 months). At the last follow-up 14 patients are alive and disease free; two are alive with local disease and four with systemic disease, and five are dead of disease. Overall local control is 19/23 (91%). The local control for patients treated with conservative excision without irradiation is 4/11 (36%) and for conservative excision with re-irradiation 10/10 (100%). Six (60%) of these patients experienced significant post-irradiation would-healing complications, but three have recovered fully. Functional scores for the entire treated group are significantly lower after treatment, as are those for patients undergoing combined surgery and re-irradiation, but 70% of those treated with conservative surgery and re-irradiation and a good or excellent post-treatment functional score. CONCLUSIONS: Combined conservative surgery and re-irradiation provided superior local control to local re-excision alone and a functional outcome superior to amputation. Combined treatment with re-irradiation should be considered the primary salvage therapy for patients who fail combined therapy and who are suitable for conservative re-excision. Systemic relapse is a significant problem, and optimal therapy should minimize the risk of local relapse after the initial therapy. Eighteen patients (72%) had a history of intralesional excision as their initial intervention, and suggests that inappropriate initial management is a risk factor for relapse after combined conservative therapy. Improvements in therapy must include the appropriate education of the primary care physicians.

Adult↗