Biomedical subjects
J Short
Publications and source records attributed to J Short.
Spontaneous mutants recovered from liver and germ cell tissue of low copy number lacI transgenic rats.
The finding of a large discordance between animal species in their response to a carcinogenic challenge, has led to the realization that the useful extrapolation of animal test data to humans requires a better understanding of animal interspecies differences. With the development of transgenic shuttle vector based animal systems we are now able to study mutation of the same genetic target in both mice and rats. We have begun to analyze mutants recovered from rat lines carrying low copy numbers of the same lambda/lacI constructs carried by the Big Blue mouse. A large database on mutations in lacI transgenic mice is already available for comparison. The data indicate that the differences between the mutations recovered from rat liver and germ cell tissues are similar to those recovered from transgenic mice, but when compared with a large database of mutations available for mice, some site-to-site differences may exist. This study represents the first interspecies look into the molecular nature of mutations in the lacI transgenic rodents.
Case study: anorexia nervosa and autistic disorder in an adolescent girl.
The development of anorexia nervosa in a high-functioning, early adolescent, autistic female is described. This case raises the issue of co-occurrence of childhood-onset disorders sharing the phenomena of obsessions and compulsions. The role of dysregulation of the serotonergic neurotransmitter system as a common underlying mechanism in these disorders is suggested. Psychoactive agents affecting the serotonin system and in particular the atypical neuroleptic risperidone may be of value in these disorders. There is added benefit to the combined use of biological and behavioral therapies.
Vaginal wall sling for anatomical incontinence and intrinsic sphincter dysfunction: efficacy and outcome analysis.
PURPOSE: A prospective cohort study was done to determine the efficacy and clinical outcome of a new technique for anterior vaginal wall sling construction to treat urinary incontinence due to intrinsic sphincter dysfunction or anatomical incontinence. MATERIALS AND METHODS: Preoperative evaluation included lateral cystography, video urodynamics, cystoscopy and incontinence staging. Postoperative subjective and objective staging outcome measures were prospectively assigned at predetermined regular intervals by a third party. RESULTS: Of the patients 95 had intrinsic sphincter dysfunction and 65 had anatomical incontinence. The repair failed in 7% of the 160 patients who had recurrent incontinence during followup and 9% had de novo urgency incontinence. Time to failure comparing patients with intrinsic sphincter dysfunction and anatomical incontinence was modeled using Kaplan-Meier survival curves, and the log rank test showed no significant difference between the groups (p > 0.05). Logistic regression covariates revealed no significant predictive factors for postoperative failures. Preoperative patient age was the only predictive factor for de novo instability (logistic regression model p < 0.05). CONCLUSIONS: Our initial results indicate that the 2 groups are indistinguishable to date based on current clinical and experimental statistics except for time to full recovery of postoperative voiding and incidence of postoperative instability (regression model p < 0.05).
Pharmacologically induced regression of chronic transplant rejection.
Chronic rejection, characterized by a progressive obliterative arteriopathy, is a major cause of graft failure in long-surviving human transplants for which there is no effective treatment. Leflunomide, an isoxazol derivative, has been shown to be a novel immunomodulatory drug that profoundly suppresses the immune response. In this study, 58 Fisher-344 rats received cardiac transplantation from Lewis rats. All the recipients were given CsA at 2.5 mg/kg for 5 days postoperatively. Without further treatments, the arterial intima was progressively injured by mononuclear cell infiltration and Ab deposition. Smooth muscle cell and fibroblast proliferation in the intima became a predominant phenomenon by day 90. CsA was ineffective in controlling the progress of arterial intimal thickening when treatment began on day 30. Leflunomide at 5 mg/kg failed to control arterial intimal thickening by day 60 when therapy began on day 30. However, the progress of arterial intimal thickening was significantly inhibited by day 90 when the dosage of leflunomide had been increased to 10 mg/kg on day 60. Combined therapy with leflunomide and CsA at 5 mg/kg for 30 days dramatically reversed the arterial thickening by day 60. After increasing the dosages of both leflunomide and CsA to 10 mg/kg on day 60, the combination therapy steadily controlled the chronic rejection. Only the combination therapy significantly down-regulated circulating antidonor IgM and IgG titers. In rat smooth muscle cell culture, this same drug combination had a synergistic inhibitory effect on proliferation. Therefore, the combination therapy of leflunomide and CsA could reverse and control the progress of chronic rejection, while leflunomide, at higher dosage as a monotherapy, could stabilize chronic rejection in this model. The mechanism of the regression of chronic rejection by leflunomide and cyclosporine may be related to their in vitro abilities to control not only lymphocyte but smooth muscle cell proliferation, as well. The synergistic effect of these two drugs on vascular smooth muscle cell proliferation in vitro may be an important part of this novel activity. This unique feature holds intriguing possibilities for treating established chronic rejection.
Small bowel obstruction caused by a retained percutaneous endoscopic gastrostomy gastric flange.
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Failure in community care. Supervision register needs rethinking.
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LA earthquake shakes foodservice foundations.
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Planning a continuing education program: the model for health education planning.
1. Development of CE programs for occupational health nurses is integral to professional development. Occupational health nurses are constantly being required to increase and upgrade skills. 2. Evolving issues in health care reform reflect an emphasis on the cost effective, quality care provided by well prepared occupational health nurses. Thus, the need for providing high quality programs and resources for occupational health nurses becomes a challenge for CE providers. 3. The Model for Health Education Planning (MHEP) is used to describe the development of a program. The MHEP includes six phases: initiation, needs assessment, goal setting, planning/programming, implementation, and evaluation. 4. Use of the MHEP ensures that the program planning process is achieved in an appropriate manner. The focus is on meeting the needs of the learner.
Teaching resuscitation techniques.
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The latest proposals for changing the British NHS: a health service manager's view of the White Paper.
The nature of the plans for change detailed in the National Health Service review White Paper, Working for Patients, which was presented to the British Parliament on 1 February 1989, are examined in this paper. Seven key measures are identified and outlined. The author extrapolates from the nature of the plans contained within the White Paper, the types of problems within the NHS that are attracting government attention. Questions are raised as to the appropriateness and likelihood of success of the White Paper plans in view of the problems currently besetting the NHS.
Effect of the hemopump left ventricular assist device on regional myocardial perfusion and function. Reduction of ischemia during coronary occlusion.
The Hemopump is a new 7-mm diameter left ventricular assist device that provides as much as 3.5 l/min of nonpulsatile cardiac output after fluoroscopic placement into the left ventricle through a femoral artery cutdown. The purpose of this study was to measure the effects of Hemopump assist on hemodynamics, left ventricular function, and perfusion in the presence and absence of ischemia. Eight dogs were instrumented under pentobarbital anesthesia with left ventricular, left atrial, and aortic catheters, a loose silk ligature around the midleft anterior descending coronary artery, and sonomicrometer crystals in midwall myocardium within the left anterior descending and circumflex perfusion territories. Hemodynamic variables, regional systolic fractional shortening, and myocardial perfusion after left atrial injection of 15-microns radiolabeled microspheres were measured in the presence and absence of Hemopump assist before and after left anterior descending artery occlusion. In the absence of ischemia, Hemopump left ventricular assist resulted in reduced left ventricular end-diastolic pressure while aortic mean pressure was maintained, and there was significant reduction in regional systolic fractional shortening (reflecting systolic unloading) that correlated with an 18% decline in regional myocardial perfusion. During left anterior descending artery occlusion, left ventricular systolic and diastolic pressures were reduced during Hemopump assist while aortic mean pressure was maintained. Perfusion rose in the ischemic territory (from 13.0 +/- 8.7% to 26.2 +/- 19.8% of nonischemic flow, p = 0.045). Reduced fractional shortening was again seen in nonischemic tissue with Hemopump assist during left anterior descending artery occlusion, and this was often correlated with reduced perfusion (r = 0.67).(ABSTRACT TRUNCATED AT 250 WORDS)
Replacements of lysine 32 in yeast cytochrome c. Effects on the binding and reactivity with physiological partners.
Lysine 32 has been previously implicated by chemical modification and modeling studies as a key component of the domain which controls recognition and binding of cytochrome c to its physiological partners, e.g. cytochrome b2, cytochrome c peroxidase, and cytochrome oxidase. In order to quantitate the importance of this residue, we have investigated the role of Lys-32 in the reactivity of cytochrome c in redox reactions in vitro and in vivo with protein partners by using a series of altered forms of iso-1-cytochrome c from the yeast Saccharomyces cerevisiae in which Lys-32 is replaced by Leu-32, Gln-32, Trp-32, and Tyr-32. Leu-32 and Gln-32 represent substitutions which change charge without seriously affecting the steric bulk of the side chain or the stability of the protein. For the Leu-32- and Gln-32-altered proteins, steady state kinetic studies with cytochrome c peroxidase, cytochrome b2, and cytochrome oxidase showed that neither of the steady state kinetic parameters, Km nor Vmax, were substantially modified by mutation. Studies of single turnover kinetics with a small molecule (ascorbate) or within bound complexes with either cytochrome b5 or cytochrome c peroxidase demonstrated that redox kinetics are only slightly affected by these substitutions. NMR experiments demonstrated that the Gln-32-altered protein can still bind strongly to a physiological partner, cytochrome c peroxidase. Growth in lactate medium demonstrated that the activity in vivo compared with the normal value was reduced to only 85% with the Gln-32- and Leu-32-altered proteins and to 65% with the Trp-32- and Tyr-32-altered proteins. These findings suggest that the evolutionary invariance of Lys-32 reflects only small quantitative changes in the binding and reactivity of cytochrome c.
Keeping up with the cockroaches.
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The effects of shift work on nurses: implications for Australian hospitals.
This review of Australian and international research on the effects of shift work on nurses reveals that there is neither a wide nor a growing body of information on shift work in nursing. Shift work in nursing has been the subject of only three substantial studies overseas, and none in Australia. Although research indicates that there are negative physiological, psychological and social consequences associated with shift work, it is not possible at the current time to favour any single shift or roster system, particularly in nursing where empirical research is wanting.
Treatment of loin pain/haematuria syndrome by renal autotransplantation.
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Replacement of the invariant lysine 77 by arginine in yeast iso-1-cytochrome c results in enhanced and normal activities in vitro and in vivo.
Oligonucleotide-directed mutagenesis of the yeast Saccharomyces cerevisiae was used to generate an abnormal iso-1-cytochrome c having an Arg-77 replacement of the normal Lys-77; this Lys-77 residue is evolutionarily conserved in most eukaryotic cytochromes c and is trimethylated in fungal and plant cytochromes c. Examination of strains having a single chromosomal copy of the gene encoding the Arg-77 protein indicated that the altered protein was synthesized at the normal rate and that it had normal or near normal activity in vivo. Examination of enzymatic activities in vitro with cytochrome b2, cytochrome c peroxidase, and cytochrome c oxidase indicated that the altered iso-1-cytochrome c has equal or enhanced catalytic efficiencies. Thus, replacement of the evolutionarily conserved residue Lys-77 produces no or only minor effects both in vivo and in vitro.
Validity of MCAT scores as predictors of preclinical grades and NBME Part I examination scores. Medical College Admission Test. National Board of Medical Examiners.
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