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Biomedical subjects

T Shanahan

Publications and source records attributed to T Shanahan.

13 recordsLinked to original sources
PubMed2000

Frequency, potential risk and therapeutic intervention in end-stage renal disease patients with antiphospholipid antibody syndrome: a multicenter study.

BACKGROUND: Antiphospholipid antibody syndrome (APAS) is characterized by the presence of anticardiolipin antibodies (ACA) in association with thrombotic disorders of arterial and/or venus systems, spontaneous abortion(s) or thrombocytopenia. METHODS: In this multicenter study, 502 end-stage renal disease (ESRD) patients awaiting renal transplants were screened to determine the frequency of APAS, the potential risk associated with APAS, and strategies for therapeutic intervention. Ninety-three patients (19%) had high titers of ACA. Twenty-three patients had documented evidence of one or more of the thrombotic disorders such as lupus, frequent abortions, frequent thrombosis of arteriovenous shunts, biopsy-proven microrenal angiopathy, or thrombocytopenia and thus were diagnosed with APAS. Of these 23 patients, 11 received kidney transplants either with (4 patients) or without (7 patients), concomitant anticoagulation therapy. RESULTS: All seven of the patients with APAS not treated with anticoagulation therapy lost their allografts within 1 week as a result of renal thrombosis. In contrast, three out of four transplant patients with APAS treated with anticoagulation therapy maintained their allografts for over 2 years. The fourth patient lost his graft within a week because of thrombosis. Of the remaining 70 patients with high titers of ACA but no evidence of thrombotic disorders, 37 received kidney transplants. None lost their allografts as a result of thrombosis. Our data suggest that, although 19% of our ESRD patients exhibit high titer of ACA, only 5% of the patients have APAS. CONCLUSION: In conclusion, our data suggest that the patients with APAS are at high risk of posttransplant renal thrombosis. Anticoagulation therapy could prevent patients from posttransplant thrombosis in patients with APAS.

Antibodies, Anticardiolipin↗
PubMed1999

Evolutionary progress from Darwin to Dawkins.

Is evolution 'progressive'? Biologists have been deeply divided in their answers to this question for over a century and a half. Darwin addressed the question in On the Origin of Species, prominent evolutionists debated the issue again in the middle decades of this century, and the issue has attracted renewed attention recently. Remarkably, the seeds of a solution to the problem may lie in Darwin's earliest private reflections on simplicity, complexity and the evolution of life.

Animals↗
PubMed1995

The relationship of patients' cognitive status and therapists' ratings of psychological distress among psychoactive substance users in long-term residential treatment.

Patients in a long-term residential substance abuse treatment program (N = 168) were asked to complete the Symptom Checklist-90-Revised (SCL-90-R), a brief inventory that measures psychological distress in nine symptom areas. Using the Symptom Checklist-90 Analogue (SCL-90 Analogue), which allows raters to assess patients along the same dimensions measured by the SCL-90-R, therapists also estimated the degree of psychological distress they observed in their patients. Significantly larger discrepancies were found between therapists' ratings of their patients and patients' ratings of themselves when patients were cognitively impaired (N = 57) than when patients did not display these decrements (N = 111). Furthermore, these patient-therapist assessment differences were negatively related to measures of patients' participation in treatment and length of stay in the program. Clinical and research implications of these findings are discussed.

Adaptation, Psychological↗
PubMed1993

Oropharyngeal swallowing after stroke in the left basal ganglion/internal capsule.

One of the foci of Martin Donner's work was the neural control of swallowing. This present investigation continues that work by examining oropharyngeal swallowing in 8 patients identified with a single, small, left-basal ganglion/internal capsule infarction and 8 age-matched normal subjects. Stroke patients were assessed with a bedside clinical and radiographic swallowing assessment, and normal subjects received only the radiographic study. Results revealed disagreement between the bedside and radiographic assessments in one of the 8 stroke patients. Stroke and normal subjects differed significantly on some swallow measures on various bolus viscosities, but behaved the same as normal subjects on a number of measures. Differences in swallowing in the stroke subjects were not enough to prevent them from eating orally. The significant differences seen in the basal ganglia/internal capsule stroke subjects may result from damage to the sensorimotor pathways between the cortex and brainstem. These differences emphasize the importance of cortical input to the brainstem swallowing center in maintaining the systematic modulations characteristic of normal swallowing physiology.

Adult↗
PubMed1993

Resource utilization. High dose rate versus low dose rate brachytherapy for gynecologic cancer.

A comparative analysis of anesthesia use, perioperative morbidity and mortality, capital, and treatment cost of high dose rate versus low dose rate intracavitary brachytherapy for gynecologic malignancy is presented. To assess current anesthesia utilization, application location, and high dose rate afterloader availability for gynecologic brachytherapy in private and academic practices, a nine-question survey was sent to 150 radiotherapy centers in the United States, of which 95 (63%) responded. Of these 95 respondents, 95% used low dose rate brachytherapy, and 18% possessed high dose rate capability. General anesthesia was used in 95% of programs for tandem + ovoid and in 31% for ovoids-only placement. Differences among private and academic practice respondents were minimal. In our institution, a cost comparison for low dose rate therapy (two applications with 3 hospital days per application, operating and recovery room use, spinal anesthesia, radiotherapy) versus high dose rate treatment (five outpatient departmental applications, intravenous anesthesia without an anesthesiologist, radiotherapy) revealed a 244% higher overall charge for low dose rate treatment, primarily due to hospital and operating room expenses. In addition to its ability to save thousands of dollars per intracavitary patient, high dose rate therapy generated a "cost-shift," increasing radiotherapy departmental billings by 438%. More importantly, perioperative morbidity and mortality in our experience of 500+ high dose rate applications compared favorably with recently reported data using low dose rate intracavitary treatment. Capital investment, maintenance requirements, and depreciation costs for high dose rate capability are reviewed. Application of the defined "revenue-cost ratio" formula demonstrates the importance of high application numbers and consistent reimbursement for parity in high dose rate operation. Logically, inadequate third-party reimbursement (e.g., Medicare) reduces high dose rate parity and threatens the future availability of high dose rate technology.

Anesthesia↗
PubMed1991

Chance as an explanatory factor in evolutionary biology.

Darwinian evolutionary biology has often been criticized for appealing to the notion of 'chance' in its explanations. According to some critics, such appeals exhibit the explanatory poverty of evolutionary theory. In response, defenders of Darwinism sometimes downplay the importance of 'chance' in evolution. I believe that both of these approaches are mistaken. The main thesis of this paper is that the term 'chance' encompasses a number of distinct concepts, and that at least some of these concepts serve essential explanatory functions in evolutionary biology. This claim is defended by way of an historical survey of the major concepts of 'chance' in the history of evolutionary biology, especially the concepts used by Jean Baptiste Lamarck, Charles Darwin, and Sewall Wright. An examination of their biologies shows how the concepts of 'chance' used cohere with their major scientific objectives and methods. These concepts survive and continue to function as important explanatory factors in contemporary evolutionary biology. Examples of such usage are given, and the explanatory status of 'chance' assessed.

Adaptation, Biological↗
PubMed1990

The effect of a bacterial vaccine on tumors and the immune response of ICR/Ha mice.

This study examined the effect of mixed bacterial vaccine (MBV), a biological response modifier prepared from Streptococcus pyogenes and Serratia marcescens, on the immune system of mice and on the regression of a transplantable mouse tumor sarcoma 37. The study examined MBV's biological properties and analyzed its chemical composition. The chemical composition varied with the growth media. A typical centrifuged, dialyzed supernate of the serum-containing preparation was found to consist mainly of protein and minimal amounts of carbohydrate and endotoxin, while MBV made with synthetic medium contained similar amounts of all three. MBV was nontoxic for mice, which gained weight following the injection of 0.5-1.0 ml of MBV. MBV caused regression of 20-100% of well-established mouse tumors without appreciable toxicity. MBV also had a striking effect on the immune response of mice to sheep red blood cells. When administered simultaneously with antigen injection, MBV increased the number of antibody-secreting splenocytes measured by the plaque-forming assay threefold. Serum antibody levels also increased two- to threefold. MBV did not enhance the immune response to pneumococcal polysaccharide type III, a B-cell-dependent response. However, the in vivo administration of MBV increased the in vitro response to MBV and the B-cell mitogen lipopolysaccharide. MBV compares favorably with other biological response modifiers because of its enhancing effect on the immune response and its oncolytic properties at nontoxic levels.

Animals↗
PubMed1985

A descriptive analysis of high school seniors with speech disabilities.

Of over 26,000 high-school seniors for whom survey data from the recent High School and Beyond study were complete, 278 identified themselves as having speech disabilities. The data on these latter students were compared to those on their nonimpaired peers with regard to demographic variables and measures of achievement, personal characteristics, and relationship to school and work. These orally handicapped pupils tended to be older, more often from linguistic minority groups, and tended to present more additional handicapping conditions. The data also showed the impaired group at a disadvantage regarding achievement, self-image, motivation, and career aspirations. Some possibilities for ameliorating these conditions are suggested.

Achievement↗
PubMed1983

Behavior of single- and mixed-sex infections of Nippostrongylus brasiliensis in fed and fasted mice.

The behavior of male and female Nippostrongylus brasiliensis differed in the intestines of mice. Intraintestinal insertion of female worms at sites that represented 5 or 20% of the pyloric-caecal distance revealed localization at those sites, whereas male populations dispersed over 50% of the intestinal length. However, introduction of females at 40% of the intestine showed a wider distribution that was similar to the male's behavior at all three locations in the intestine. Insertions of both sexes reduced the male's dispersal behavior and arrested the female's preferential localization at the 5 and 20% intestinal sites. Females that were posterior in the intestine showed no dose-dependent movement toward males that were more anterior over various distances or with various combinations of ages of males and females. Food deprivation altered the behavior of females, but this change was inhibited, apparently by males, in bisexual groups. Dispersal of bisexual populations in the intestine was independent of helminth density after fasting of the host.

Animals↗
PubMedDate not supplied

Application of flow cytometry in transplantation medicine.

Immunological rejection remains a major barrier to successful organ transplantation. Consequently, immunosuppressive intervention to prevent or control the rejection process renders the transplant recipient susceptible to infectious diseases. Flow cytometry has become a useful tool for monitoring immunological responses in transplant recipients. There are three areas of clinical transplantation immunology that may benefit from this technology. First, characterizing and classifying alloreactive antibodies by flow cytometry identifies high-risk donor and recipient combinations with greater precision. Second, the ability to detect subtle changes in the cellular components of the immune system cytometrically may facilitate the differential diagnosis of rejection, infection, and iatrogenic toxicity. Finally, the ease with which flow cytometry determines the adequacy or inadequacy of immunosuppressive therapy through T cell receptor analyses serves to maximize the beneficial effects of engraftment.

Flow Cytometry↗
PubMedDate not supplied

Bellyboard device reduces small bowel displacement.

The ability to cure several pelvic malignancies is hampered by the inability to deliver doses greater than 45 to 50 Gy, beyond which radiation enteritis becomes dose-limiting. The design and fabrication of a device that allows exclusion of small bowel from the pelvis during radiation therapy are described in this study. A prospective dose-volume analysis conducted on 30 patients reveals a 66 percent reduction in the volume of small bowel within the radiation portals.

Equipment Design↗