Biomedical subjects
Publications and source records attributed to B Thomas.
Two children with diabetes insipidus secondary to a chronic inflammatory infiltrate of the infundibulum - infundibuloneurohypophysitis - are presented. Features unique to these cases are contrasted with prior case reports. The differential diagnoses of diabetes insipidus and inflammatory pituitary disorders are discussed. Recommendations for diagnosis and treatment are proposed.
The incidence of heart failure (HF) is increasing while numerous pharmacological breakthroughs have been accomplished in the last two decades. Mortality remains high and is comparable to mortality due to oncologic disease. Coronary artery disease and hypertension are the primary causes of heart failure in Western societies while valvular heart disease is a significant cause in economically underdeveloped societies. While there are many pharmacological therapies for systolic disfunction, little is known about the optimal way to treat diastolic dysfunction. Although William Withering described the properties of digitalis in 1785, two hundred years passed before a scientific trial documented its benefit in HF. Skilled dissection and probing of the molecular basis of cardiac muscle contraction led to the development of numerous compounds postulated to be more effective than digitalis, only to disappoint repeatedly in numerous trials. In contrast, ACE inhibitors (ACEI) revolutionized the management of HF and it is unlikely that another class of agents will show dramatic improvements like the ACEI. Therefore, the pharmacological therapy of HF is proving to be more an art than a science, as numerous agents have to be tuned against each other to produce an overall effect that is beneficial.
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This retrospective study was undertaken to investigate the patency and limb salvage rates of 308 PTFE infrainguinal bypasses in 272 patients over a 5-year period. In addition a univariate analysis was performed to identify factors that could predict the outcome of these operations. Long-term survival was 83% and 50% at one and five years respectively. For the whole series the primary cumulative patency at one and five years was 70% and 41% respectively. Graft revision for failed or failing grafts resulted in secondary patency rates of 78% and 43% for the same periods. The limb salvage rates were 93% and 84% at one and five years. Patency rates showed no statistical significant difference for gender, age at operation or the use of a venous cuff at the distal anastomosis. Although there was a tendency towards better results for above the knee operations, this difference failed to achieve statistical significance. Only redo operations were associated with a significant worse outcome.
OBJECTIVES: To compare prostaglandin production and cyclooxygenase activity in high-density primary cultures of chondrocytes from patients with osteoarthritis and from healthy controls. METHODS: Chondrocytes harvested from operative specimens obtained during hip or knee arthroplasty were cultured at a very high density for 48 h. Cyclooxygenase activity was evaluated based on prostaglandin E2 levels (radioimmunological assay) after addition of arachidonic acid. The chondrocytes were cultured with and without IL-1 beta and TNF alpha. RESULTS: Prostaglandin E2 production and cyclooxygenase activity were significantly higher in cultures of chondrocytes from osteoarthritic than from healthy joints. Adding IL-1 beta to the osteoarthritic chondrocyte cultures further increased the high cyclooxygenase activity, whereas adding TNF alpha alone had no effect. CONCLUSION: Cultured chondrocytes from osteoarthritic joints showed increased prostaglandin E2 production and cyclooxygenase activity.
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This paper highlights the accreditation issues raised by new and emerging models of baccalaureate nursing education and program delivery in Canada. It suggests ways of adapting the accreditation process to address recent changes. Nursing degree programs now offered by universities include programs at several sites, collaborative programs with partner institutions at multiple sites, and programs offered primarily through distance education. The accreditation program developed by the Canadian Association of University Schools of Nursing (CAUSN) provides a mechanism for monitoring the quality of a nursing education program and promoting the growth of the school that offers the program. Since the decision to undergo accreditation signifies a major commitment on the part of a nursing program, it is essential that the accreditation process be adaptable to meet the needs of evolving nursing education and program delivery models, and that it be fair, equitable, and credible.
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Initiating a collaborative health education program about breast health required talent, expertise, and workload contributions from all involved including university researchers, a regional breast screening agency, and local industries. The credibility and opinions of liaisons or key informants were valued highly, and their support was critical to the success of the project. Participation in any collaborative project is predicated on benefits perceived by each of the partners. The community agency reaped the benefits of greater dissemination of their educational materials through the interventions. The project increased corporate and union awareness of the resources of this agency and in this community. Throughout the project, meetings and telephone conferences were held on a weekly or biweekly basis with the liaisons. Liaisons disseminated updates to management and union representatives.
The arousal hypothesis of the trial-spacing effect suggests that spaced-trial training increases emotional arousal and thus invigorates Pavlovian behavior, relative to massed-trial conditions. Emotional arousal was manipulated by varying reinforcer magnitude during training (either one or five food pellets/trial, across groups). In addition, autoshaping training was administered either in the morning (0900 h) or in the evening (1700 h). Rats were housed in an enclosed colony room and exposed to a regular light:dark cycle (light from 0700 to 1900 h). Available evidence indicates that reinforcer magnitude and time of day are related to arousal levels. As expected, a larger reinforcer magnitude led to a highly significant trial spacing effect. Evening training led to a higher response rate than morning training, but the trial-spacing effect was equally strong whether training was administered in the morning or in the evening. These results provide partial support for the arousal hypothesis and are discussed in the context of research on schedule-induced behavior.
CONTEXT: Human immunodeficiency virus (HIV) infection has been associated with an increasing incidence of malignancy, and HIV-infected persons have an increased incidence of primary lung carcinoma compared with the general population. OBJECTIVE: To investigate the molecular changes present in HIV-associated lung tumors and compare them with those present in lung carcinomas arising in HIV-indeterminate subjects ("sporadic tumors"). DESIGN: Convenience sample. SUBJECTS: Archival tissues from 11 HIV-positive persons and from 35 persons of indeterminate HIV status. SETTING: University-based medical centers and affiliated hospitals. MAIN OUTCOME MEASURES: Analysis of frequency of loss of heterozygosity (LOH) and microsatellite alteration (MA) using polymerase chain reaction and 16 polymorphic microsatellite markers at 8 chromosomal regions frequently deleted in lung cancer. Presence of HIV and human papillomavirus (HPV) sequences. RESULTS: The overall frequency of LOH at all chromosomal regions tested and the frequencies at most of the individual regions were similar in the 2 groups. Frequency of MA present in the HIV-associated tumors (0.18) was 6-fold higher than in sporadic tumors (0.03) (P<.001). At least 1 MA was present in 10 (91%) of 11 HIV-associated tumors vs 17 (48%) of 35 sporadic tumors (P=.02). Molecular changes were independent of tumor stage and gender. HIV and HPV sequences were not detected in the HIV-associated lung carcinomas. CONCLUSIONS: Microsatellite alterations, which reflect widespread genomic instability, occur at greatly increased frequency in HIV-associated lung carcinomas. Although the mechanism underlying the development of increased MAs is unknown, it may play a crucial role in the development of many HIV-associated tumors.
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The subchronic toxicity of antimony in drinking water was studied in the rat. Male and female Sprague-Dawley rats (127-135 g body weight, 15 animals per group) were exposed to a soluble trivalent antimony salt, potassium antimony tartrate, in drinking water at concentrations of 0.5, 5, 50 and 500 ppm for 13 wk. Control rats received tap water as drinking water. An additional 10 male and 10 female rats were included in each of the control and 500 ppm groups and were given tap water for a further 4-wk recovery period after the 13-week treatment period. During treatment, the highest dose animals of both sexes consumed significantly less water and showed suppressed body weight gain. During recovery, water intake was quickly restored to that of the control groups and body weight gain was accelerated. At termination, one highest dose male had a cirrhotic liver, and three highest dose males exhibited gross haematuria. Female rats showed a dose-related decrease in serum glucose starting at 5 ppm, and rats of both sexes in the highest dose group had slightly decreased alkaline phosphatase activity and creatinine. The highest dose males had decreased red blood cell and platelet counts and increased mean corpuscular volume. Hepatic glutathione S-transferase activity was increased in the highest dose males and females and ethoxyresorufin-O-deethylase activity was increased in the highest dose males. In the highest dose groups, mild adaptive histological changes were observed in the thyroid, liver and pituitary gland of both sexes, and in the spleen of male rats and thymus of female rats. After a 4-wk recovery period, the pituitary gland of both sexes appeared normal and the changes in the liver and thyroid of both sexes became less severe. On the other hand, minimal changes persisted in the spleen of both sexes and in the thymus of males. Tissue antimony levels were dose-related and follow the order: red blood cells > > spleen, liver > kidney > brain, fat > serum. After the recovery period, antimony level in the highest dose animals decreased for all tissues except the spleen, which remained the same as before recovery. A NOAEL of 0.5 ppm antimony in drinking water, equivalent to an average intake of 0.06 mg/kg body weight/day, was established on the basis of the histological and biochemical changes observed at 5.0 ppm.
BACKGROUND: The focused assessment for the sonographic examination of the trauma patient (FAST) is a rapid diagnostic test that sequentially surveys for hemopericardium and then the right upper quadrant (RUQ), left upper quadrant (LUQ), and pelvis for hemoperitoneum in patients with potential truncal injuries. The sequence of the abdominal part of the examination, however, has yet to be validated. The objectives of this multicenter study were as follows: (1) to determine where hemoperitoneum is most frequently identified on positive FAST examinations; and (2) to determine if a relationship exists between that areas and the organs injured. METHODS: Ultrasound registries from four Level I trauma centers identified patients who had true-positive FAST examinations. Demographic data, areas positive on the FAST, and organs injured were recorded; injuries were classified as multiple, single solid organ (liver or spleen), isolated hollow viscus, or retroperitoneal. Relationships between positive locations on the FAST examinations and the associations of organs injured to areas positive were assessed using McNamara's chi2 test; a p value < 0.05 was considered statistically significant. RESULTS: The RUQ was the most common site where hemoperitoneum was detected, and this was statistically significant compared with either the LUQ or the pelvis. Also, statistically significant correlations (p < 0.001) were observed between positive RUQ areas on the FAST and multiple injuries, single solid organ (liver or spleen) injury, and retroperitoneal injuries. CONCLUSION: Blood is most often found on the FAST in the RUQ area in patients with multiple intraperitoneal injuries or isolated injury to the liver, spleen, or retroperitoneum, but not when there is injury to a hollow viscus.
Grafting experiments between phytochrome B antisense and wild-type potato (Solanum tuberosum L. subsp. andigena [line 7540]) plants provide evidence that phytochrome B is involved in the production of a graft-transmissible inhibitor of tuberization, the level of which is reduced in the antisense plants, allowing them to tuberize in noninducing photoperiods.
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Previous studies have shown that toluene, which is commonly abused, depresses neuronal activity and causes behavioral effects in both animals and man similar to those observed for ethanol. In this study, the oocyte expression system was used to test the hypothesis that toluene, like ethanol, inhibits the function of ionotropic glutamate receptors. Oocytes were injected with mRNA for specific N-methyl-D-aspartate (NMDA) or non-NMDA subunits and currents were recorded using conventional two-electrode voltage clamp. To enhance the low water solubility of toluene, drug solutions were prepared by mixing toluene with alkamuls (ethoxylated castor oil) at a 1:1 ratio (v:v) and diluting this mixture to the appropriate concentration with barium-containing normal frog Ringer solution. Alkamuls, up to 0.1%, had no significant effects on membrane leak currents or on NMDA-induced currents. Toluene, up to approximately 9 mM, had only minor effects on membrane leak currents but dose-dependently inhibited NMDA-mediated currents in oocytes. The inhibition of NMDA receptor currents by toluene was rapid, reversible and the potency for toluene's effects was subunit dependent. The NR1/2B subunit combination was the most sensitive with an IC50 value for toluene-induced inhibition of 0.17 mM. The NR1/2A and NR1/2C receptors were 6- and 12-fold less sensitive with IC50 values of 1.4 and 2.1 mM, respectively. In contrast, toluene up to approximately 9 mM did not inhibit kainate-induced currents in oocytes expressing GluR1, GluR1(+)R2 or GluR6 subunits. These results suggest that some of the effects of toluene on neuronal activity and behavior may be mediated by inhibition of NMDA receptors.