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Biomedical subjects

R Schaaf

Publications and source records attributed to R Schaaf.

8 recordsLinked to original sources
PubMed1993

A non-flight muscle isoform of Drosophila tropomyosin rescues an indirect flight muscle tropomyosin mutant.

The tropomyosin I(TmI) gene of Drosophila melanogaster encodes two isoforms of tropomyosin. The Ifm-TmI isoform is expressed only in indirect flight and jump muscles; the Scm-TmI isoform is found in other muscles of the larva and adult. The level of Ifm-TmI is severely reduced in the flightless mutant Ifm(3)3, which also is unable to jump. To explore the functional significance of tropomyosin isoform diversity in Drosophila, we have used P element-mediated transformation to express Scm-TmI in the indirect flight and jump muscles of Ifm(3)3 flies. Transformants gained the ability to jump and fly. The mechanical properties of isolated indirect flight muscle myofibres, and the ultrastructure of indirect flight and jump muscles from the transformants were comparable to wildtype. Thus, the Scm-TmI isoform can successfully substitute for Ifm-TmI in the indirect flight and jump muscles of the Ifm(3)3 strain.

Adenosine Triphosphatases↗
PubMed1993

A curriculum based on systems theory.

This paper describes an entry-level curriculum based on systems theory that was designed to promote integrated thinking and a shared image of practice among all of the members of an educational community that included students, faculty, and clinicians. Initiated in 1983, the program integrates occupational therapy theory, critical thinking, and knowledge about person-environmental transactions with traditional medical, biological, psychological, and sociological course work to create a unique educational experience. The curriculum model is based on a spiral learning process that encourages integrated thinking. Furthermore, all concepts are systematically tied to the occupation core, the central theme of the program. Fieldwork is used to reinforce ideas presented in the classroom and features discrete learning experiences where students demonstrate their integration of knowledge and skills. In an evaluation of the program, responses from 78 clinician, 51 alumni, and 132 student questionnaires; feedback from 132 fieldwork supervisors; and longitudinal data from 33 alumni confirmed that graduates are critical thinkers who appreciate the diverse needs of clients while demonstrating an appreciation for the curative effect of meaningful, goal-directed activities.

Curriculum↗
PubMed1982

[Myocardial infarction due to acute right coronary thrombosis. Treatment with in situ fibrinolysis, absence of angiographic residual stenosis].

The case of a 44 year old patient with inaugural postero-diaphragmatic myocardial infarction is reported. Coronary angiography performed at the 3 rd hour showed total occlusion of the right coronary artery at the level of its second segment. A streptokinase perfusion through a Judkins' catheter positioned in the ostium of the right coronary artery using Rentrop's technique, resulted in recanalisation of the vessel at the 45 th minute. Control coronary angiography on the 10 th day showed an angiographically normal right coronary circulation. The clinical course was complicated by a recurrence on the 12 th day with a new occlusion at the same level. This observation confirms: - the reality of acute coronary thrombosis as a mechanism of myocardial infarction in the absence of significant underlying atherosclerotic stenosis. - the value of early fibrinolytic therapy in situ for limitation of the infarcted myocardial tissues.

Adult↗
PubMed1980

Contrast-induced acute renal failure: persistent nephrogram as clue to early detection.

Renal failure from urographic contrast media is a serious potential hazard of excretory urography and is usually recognized by the clinician 24--48 hr after the procedure. The association of an abnormally increasing nephrogram with development of oliguric renal failure in children was described in 1969, but in 112 subsequent reported cases of contrast-induced renal failure, a persistent nephrographic pattern was described only once. With special attention to the abnormally persistent nephrogram, we were able to detect nine cases of contrast-induced renal failure after excretory urography. Two of these cases are discussed in detail and pertinent data on the other seven are presented.

Acute Kidney Injury↗
PubMedDate not supplied

Solid-phase acyl donor as a substrate pool in kinetically controlled protease-catalysed peptide synthesis.

Recently we have demonstrated the advantage of solid-phase substrate pools mainly in equilibrium controlled protease-catalysed peptide syntheses. The extension of this approach to protease-catalysed acyl transfer reactions will be presented. The model reaction was systematically investigated according to both the influence of solid phases present in the system on enzyme activity as well as nucleophile concentration on peptide yield. The key parameter for obtaining high peptide yield via acyl transfer is the ratio between aminolysis and hydrolysis. We combined high nucleophile concentrations with solid-phase acyl donor pools. This approach enabled us to supply ester substrate and nucleophile in equimolar amounts in a high-density media without the addition of any organic solvent. Several multi-functional di- to tetrapeptides were obtained in moderate to high yields.

Acylation↗
PubMedDate not supplied

[Duration of action of trandolapril in mild to moderate hypertensive patients evaluated by ambulatory measurement of blood pressure].

The duration of the antihypertensive action of transdolapril, a new angiotensin converting enzyme inhibitor, was studied in 23 patients using ambulatory blood pressure monitoring (ABPM) over 48 hours. After a 20-day placebo period (D1 to D20), mild to moderate hypertensive patients received 2 mg trandolapril once daily for 30 days (D21 to D50). The first 24-hour ABPM recording was performed on day 14, during the placebo run-in period. Two additional recordings were done successively on days 50 and 51 corresponding to a normal dosing day and a following day with a simulated missed dose, respectively. The three blood pressure recordings (placebo, treatment, missed dose) were compared. The average 24-hour systolic (SBP) and diastolic (DBP) blood pressure were significantly decreased by trandolapril. The mean +/- s.d. decrease between day 14 and day 50 were - 8.0 +/- 7.2 mmHg for the DBP and -13.3 +/- 7.8 mmHg for the SBP. Blood pressure was also consistently decreased during the daytime period (-8.7 +/- 7.9 mmHg for the DBP and - 15.6 +/- 8.5 mmHg for the SBP), nighttime period (-5.6 +/- 9.1 mmHg for the DBP and - 8.5 +/- 11.3 mmHg for the SBP) and early morning (- 12.3 +/- 9.7 mmHg for the DBP and - 15.9 +/- 15.1 mmHg for the SBP). The normal circadian pattern of blood pressure was maintained under treatment. The antihypertensive effect of trandolapril was sustained beyond 24 hours after the last intake: there were no significant difference beetween days 50 and 51 in terms of 24-hour, daytime and nighttime average blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Ambulatory Care↗