Biomedical subjects

M Studer

Publications and source records attributed to M Studer.

At least 37 records · Page 2Linked to original sources

PubMed1994

Role of a conserved retinoic acid response element in rhombomere restriction of Hoxb-1.

After activation in mesoderm and neuroectoderm, expression of the Hoxb-1 gene is progressively restricted to rhombomere (r) 4 in the hindbrain. Analysis of the chick and mouse Hoxb-1 genes identified positive and negative regulatory regions that cooperate to mediate segment-restricted expression during rhombomere formation. An enhancer generates expression extending into r3 and r5, and a repressor limits this domain to r4. The repressor contains a conserved retinoic acid response element, point mutations in which allow expression to spread into adjacent rhombomeres. Retinoids and their nuclear receptors may therefore participate in sharpening segment-restricted expression of Hoxb-1 during rhombomere boundary formation.

Animals↗

PubMed1994

A conserved retinoic acid response element required for early expression of the homeobox gene Hoxb-1.

Within the Hoxb homeobox gene complex, Hoxb-1 is the earliest member expressed in the mesoderm and neuroectoderm of primitive streak and presomite embryos, preceding rhombomere-restricted expression in the hindbrain. Ectopic exposure of embryos to retinoic acid alters spatial aspects of Hox gene expression patterns. However, the role of retinoids in regulating these genes during normal development is unclear. We have now identified two enhancers, 3' of the mouse Hoxb-1 gene, which together reconstruct the early endogenous expression pattern and mediate the early ectopic response to retinoic acid. Furthermore, these regions are functionally conserved in both chicken and pufferfish (Fugu rubripes) Hoxb-1 genes. The enhancer that controls the retinoic acid response, and regulates expression predominantly in neuroectoderm, contains a retinoic acid response element (RARE). Point mutations in the RARE abolish expression in neuroectoderm. Therefore, this RARE is not only involved in the ectopic response to retinoic acid, but is also essential for establishing aspects of the early Hoxb-1 expression pattern.

Animals↗

PubMed1994

[Quality assurance in nursing: nursing standard. Nausea, gagging and vomiting during emetogenic cytostatic therapies. Report of research into the development and introduction of nursing standards].

This report documents the introduction of standard-setting in the haemato-oncological reverse-isolation unit of the Kanton hospital, Basle. The topic is the prevention or reduction of nausea, choking and vomiting, and the treatment of patients who are receiving prolonged chemotherapy. The objective was quality assurance in nursing care. The definition of the desired outcome was the well-being and safety of patients. In addition the wish of the staff to increase their security in dealing with antiemetics was taken into consideration. The authors describe the basic problems they encountered in their strategies and actions for standard setting. By extensive use of measurement and evaluation it was possible, in cooperation with medical leadership, to develop instructional leaflets and checklists. Approximation to the intended outcome was achieved. The well being of patients and satisfaction of the safety-needs of staff and patients reached a high level. The report shows that the introduction of nursing standards requires great effort and a high level of commitment of the entire team. It also shows that the effort is worthwhile for patients and staff.

Antineoplastic Agents↗

PubMed1993

[Work load in occupations].

Fewer subjects return to work after acute myocardial infarction or a cardiac surgical procedure than one would expect from the results of their medical examinations and cardiac tests. To decide whether a patient is able to return to work, one has to assess his individual prognosis and measure his maximal physical working capacity without cardiac dysfunction. Psychological and socioeconomic aspects have also to be considered. Recommendations are presented for practical procedure in assessing the ability of a patient to return to work.

Adaptation, Psychological↗

PubMed1993

Hox homeobox genes and regionalisation of the nervous system.

The Hox family of homeobox-containing genes are intimately associated with the processes of axial patterning in vertebrate embryos. This family of transcription factors is widely conserved in evolution and by analogy with their Drosophila counterparts, the HOM-C homeotic genes, may play a role in establishing regional identity in a number of embryonic systems, including the CNS. The patterns of expression of these genes are linked with the generation of rhombomeres and neural crest in the developing hindbrain, and suggest that they provide a molecular system for generating a combinatorial patterning mechanism. Analysis of mouse Hox mutants generated by homologous recombination have clearly demonstrated that the genes have important roles in normal regionalisation of the hindbrain and branchial arches, and this has lead to interest in how their early patterns are established in the nervous system. The Hox genes and their relation to hindbrain segmentation therefore provide a means of examining the cascade of events which regulates pattern formation in early neural development.

Animals↗

PubMed1993

The internal mammary artery 'string phenomenon'. Analysis of 10 cases.

The internal mammary artery (IMA) string sign has been described as a narrowing of IMA grafts in the late course after coronary artery bypass grafting. It has been assumed that this phenomenon was due to competitive flow in grafts connected to only mildly stenosed coronary arteries. We analyzed 10 cases of IMA string sign operated on between March 1988 and June 1991. Bilateral IMA was used in six cases and unilateral IMA in four. The mean interval between operation and reangiography was 14 +/- 11 months. String sign of the whole length of the IMA was detected in nine cases, and of the distal part between two sequential anastomoses in one. In all cases, the stenosis of the vessel bypassed with the narrowed graft proved to be only mild (50% or less) at reangiography. In all six cases with bilateral IMA grafts, the contralateral IMA was widely patent. These were all connected to highly stenosed or occluded coronary arteries. With respect to this observation, there is a high index of suspicion that the string phenomenon occurs due to competitive flow in only mildly stenosed coronary arteries. We decided, for our strategy in coronary artery surgery, still to aim at complete revascularization using IMAs as much as possible, but to avoid connecting IMA grafts to only mildly or moderately stenosed coronary arteries.

Coronary Angiography↗

PubMed1992

Similar endothelium-dependent relaxation, but enhanced contractility, of the right gastroepiploic artery as compared with the internal mammary artery.

The right gastroepiploic artery is an alternative coronary bypass graft. The excellent graft function of the internal mammary artery has been related to its physiologic properties, particularly to endothelial function. Isolated artery rings were suspended in organ chambers for recording of isometric tension. Norepinephrine and potassium chloride evoked threefold greater contractions in the gastroepiploic artery than in the mammary artery (p less than 0.01 to 0.05), whereas the sensitivity to the catecholamine was comparable. Acetylcholine induced endothelium-dependent relaxations, but the sensitivity (pD2: 6.7 +/- 0.3) and maximal relaxation (81% +/- 9%) were slightly less in the gastroepiploic artery than in the mammary artery (pD2: 7.6 +/- 0.2; 100% +/- 0%; p less than 0.05). Histamine induced endothelium-dependent relaxations with a similar sensitivity (pD2: 7.5 +/- 0.3 and 7.2 +/- 0.1), whereas the maximal relaxation was slightly enhanced in the gastroepiploic artery. The relaxation to the nitric oxide donor SIN-1 was identical in the two arteries. Thus the right gastroepiploic artery exhibits better contractility than the internal mammary artery but comparable endothelium-dependent and endothelium-independent relaxations. The good endothelial function of the gastroepiploic artery might be important for graft function and patency, whereas the enhanced contractility may facilitate vasospasm, especially in the presence of high circulating levels of catecholamines.

Acetylcholine↗

PubMed1991

Characterization of a second promoter for the mouse liver/bone/kidney-type alkaline phosphatase gene: cell and tissue specific expression.

The second leader exon and the relative promoter of the mouse liver/bone/kidney-type alkaline phosphatase gene were identified and characterized. The transcription initiation site was determined by S1 mapping analysis. The differential expression of the two alternatively spliced transcripts was assessed in cell lines of different origin and in various tissues by polymerase chain reaction and RNase mapping analysis. The first promoter is active in embryo derived cells, whereas the second promoter is silent in basal conditions but it is activated by dibutyryl cAMP in fibroblastic cells. In the whole animal, the transcript driven by the first promoter is found in most tissues albeit at different levels, while the one driven by the second promoter is specifically expressed at high levels only in the heart.

Alkaline Phosphatase↗

PubMed1991

[Developments in mitral valve surgery].

Between 1987 and 1990 we operated on 104 patients for mitral valve disease. If possible the valve was reconstructed according to CARPENTIER's technique: 8 of 28 stenotic, 43 of 57 regurgitant and 2 of 7 mixed lesions were repaired. Twelve patients underwent re-replacement of a previously inserted mitral prosthesis. Six patients died early (7.8% after replacement, 8% after isolated replacement, 3.7% after repair and 2% after isolated repair). Five of these six patients were in NYHA class IV preoperatively. Seven patients died late after a mean observation period of 18 months (5 after replacement, 1 after double valve replacement and 1 after repair and multiple coronary bypass surgery). Prognosis is best for patients whose valve can be repaired and who are not already in NYHA class IV. The postoperative NYHA class for surviving patients is excellent (1.3 in the replacement group and 1.2 after repair).

Adult↗

PubMed1991

Retinoic acid induces liver/bone/kidney-type alkaline phosphatase gene expression in F9 teratocarcinoma cells.

All-trans retinoic acid (RA) induces alkaline phosphatase (ALP) activity by 3-8-fold in murine F9 teratocarcinoma cells, in parallel with their differentiation towards primitive endoderm. The elevation of ALP activity is associated with increases in the amounts of liver/bone/kidney-type ALP protein and the respective transcript. These effects of RA are due to activation of ALP gene transcription rather than to an increase in the half-life of the mRNA. Induction of ALP mRNA does not require de novo protein synthesis, since it is not blocked by treatment with cycloheximide. Dibutyryl cyclic AMP, which is known to induce further differentiation of F9 cells from the primitive to the parietal endoderm, blocks the induction of ALP mRNA by RA.

Alkaline Phosphatase↗

PubMed1991

[Use of the right gastroepiploic artery as a coronary bypass graft. Indications, technique and early results].

435 isolated coronary artery procedures have been performed between January and December 1989 at the HerzZentrum Hirslanden. In 93% of the cases, one or two internal mammary arteries (IMA) and in 7%, saphenous vein grafts only were used as a bypass conduit. In 12 patients, the right gastroepiploic artery (RGE) was used as a free (3) or pedicled (9) graft to the posterior surface of the heart. This group of 12 patients was analyzed in a retrospective study. Postoperative complications in this group included one myocardial infarction and reexploration for intraabdominal bleeding in the same patient. All patients were discharged from hospital after an average of 9.7 days. After a mean follow-up time of 5 months, all patients are in NYHA-functional class I without antiischemic drugs. Postoperative angiography in 7 patients (mean postoperative interval 4 months) showed all 13 IMA-grafts and 5 RGE-grafts patent, 1 RGE-conduit is occluded, 1 RGE-graft could not been assessed for technical reasons. The RGE is an viable additional arterial bypass conduit and an alternative to other grafts. Indications for use of the RGE are lack of sufficient other conduits, calcified ascending aorta, coronary reoperation after vein graft failure and probably young patients with severe hyperlipidemia.

Arteries↗

PubMed1991

[Effect of electrically powered dental devices on cardiac parameter function in humans].

Electrically powered devices represent a hazard for patients with cardiac pacemakers. The aim of the present investigation was an in vivo evaluation of possible interactions between electrically powered dental instruments and the function of artificial pacemakers in humans. In 26 patients with artificial pacemakers, different dental instruments were applied, including air scaler, ultrasonic curets, electric pulp tester and electrotome. These devices were applied at highest intensity. Immediately prior to, during, and immediately after applications of these instruments, the pulse rate and the electrocardiogram (EKG) were recorded. The EKG recordings were assessed for irregularities in the distances between the pacemaker peaks. The dental devices were assessed for magnetic fields or induction tension. The results showed that none of the dental devices caused an irregularity in the pacemaker function. The air scaler, Piezon ultrasonic curet and the electric pulp tester caused no measurable magnetic fields. The Sonus 2 ultrasonic curet and the electrotome magnetic fields were measured up to 60 and 50 cm, respectively. All dental devices caused induction tension. The highest value was produced by the electrotome. It seems that cardiac pacemaker function is not affected by electrically powered dental devices. However, there remains a risk in relation to older pacemakers or defective dental devices.

Adult↗

PubMed1991

[Emergency surgery for PTCA complications: tactics and results].

Incidence, risk and results of emergency coronary bypass surgery after failed percutaneous transluminal coronary angioplasty (PTCA) have been analyzed in a retrospective study. Failed PTCA has been defined as visible pathology (dissection, occlusion) of the dilated vessel associated with acute chest pain and ECG changes. From 3-1-1987 to 11-30-1990, 23 patients of 433 (5%) underwent emergency surgery for failed PTCA (19 male, 4 female, mean age 55 +/- 8 years). PTCA was performed in 16 cases of one-vessel-disease, 3 cases of two-vessel-disease and 4 cases of three-vessel-disease. All had an ejection fraction beyond 40%. 19 patients remained in stable hemodynamic condition. In average 2.1 vessels have been bypassed; in 13 cases the internal mammary artery (IMA) has been used, in 10 cases the saphenous vein (VSM) only. No early nor late death occurred. The perioperative infarction rate is 30%. Comparing the group with IMA and the group with VSM only, no difference could be found regarding the number of unstable hemodynamics, the use of catecholamines nor the perioperative infarction rate. After a mean follow-up period of 14.3 months, 21 patients are in NYHA class I, 2 in NYHA class II. Emergency coronary bypass surgery can be performed with low risk and favorable results, if the operation is timed without delay after the onset of acute chest pain and ECG changes in failed PTCA. The infarction rate is remarkably higher than in elective coronary surgery. The use of the IMA seems to be no additional risk factor.

Angioplasty, Balloon, Coronary↗

PubMed1990

Isolation and characterization of the mouse liver/bone/kidney-type alkaline phosphatase gene.

The gene coding for the mouse alkaline phosphatase expressed in liver, bone, kidney and placenta (liver/bone/kidney-type alkaline phosphatase, L/B/K-ALP) was isolated and characterized. This gene consists of 12 exons and it is at least 49 kb long. The first two exons are separated by a long intron which is at least 32 kb in size, whereas the other exons span within the remaining 17 kb. Primer extension and S1-nuclease mapping analyses with placental mRNA demonstrate a single major transcription start site, which is preceded by a G + C-rich region containing a TATA-like sequence and three copies of the consensus binding site for the transcription factor Sp1. Transfection experiments using two different reporter genes show that the 5'-flanking region of the gene is active as a promoter in undifferentiated F9 teratocarcinoma cells, but not in 3T3 fibroblasts, consistent with the L/B/K-ALP mRNA level in the two cell lines. As expected from the sequence similarity at the cDNA level, the structural organization of the mouse gene is similar to that of the human and rat L/B/K-ALP genes, suggesting that they all derive from a single ancestral gene.

Alkaline Phosphatase↗

PubMed1990

Refinement of the Iowa Self-Assessment Inventory.

Two samples of older respondents (N = 1,153 and N = 420) were used in the refinement of the Iowa Self-Assessment Inventory (ISAI). Factor analyses based on data obtained from these samples resulted in modification of the original six-scale inventory to an inventory of seven scales: economic resources, anxiety/depression, physical health, alienation, mobility, cognitive status, and social support. The original ISAI was shortened from 120 to 56 items.

Activities of Daily Living↗

PubMed1990

[Heart center surgery in the private hospital: heart surgery in the hospital with covering physicians].

Based upon the experiences at the "Herzzentrum Hirslanden" Zurich it is demonstrated that heart surgery and invasive cardiology, including cardiac catheterization and PTCA, can readily be performed by surgeons and cardiologists in private practice at a private hospital not receiving any government funds. The needs for additional heart surgical beds in the greater area of Zurich is confirmed. Manpower needed and necessary apparative infrastructure are discussed and present activities at the "Herzzentrum Hirslanden" illustrated. Finally problems with medical insurance companies covering the cost are dealt with.

Cardiac Surgical Procedures↗

PubMed1989

Isolation and characterization of variant cDNAs encoding mouse tyrosinase.

Two different cDNA clones encoding mouse tyrosinase (monophenol oxygenase, E.C. 1.14.18.1) were isolated from B16 melanoma cells, and their primary structure was determined. One of the cDNAs consists of 3309 nucleotides with an open reading frame coding for a peptide of 533 amino acids. The other cDNA is approximately 1600 nucleotides long, with a shorter 3'-untranslated region and a deduced in-frame deletion of 77 amino acid residues with respect to the former clone. Neither of these clones is structurally identical to other described mouse tyrosinase cDNAs (1-3). RNA blotting analysis demonstrates that multiple tyrosinase mRNA species are not only present in B16 melanoma, but also in normal skin melanocytes.

Amino Acid Sequence↗

PubMed1989

Incidence, prevalence, and variables associated with low back pain in staff nurses.

The morbidity, lost work time, and interference with effective work due to low back pain are markedly underestimated when only employee health service data are used. Injured subjects averaged more years of generic, orthopedic, and rehabilitation nursing experience than the non-injured group. Of the studied nurses who experienced work related low back pain within the past 6 months, 78% did not report it to management. More attention should be given to adequate staff availability for shared lifting activities, better design and use of mechanical lifting aids, and further research in how to safely perform tasks from the side of the bed.

Adult↗