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Biomedical subjects

M Studer

Publications and source records attributed to M Studer.

At least 19 recordsLinked to original sources
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↗
PubMed1989

[Blood saving measures in heart surgery].

Retransfusion of mediastinal shed blood after cardiopulmonary bypass has markedly reduced requirements of homologous blood or blood products. It also decreased the incidence of early reoperation for bleeding. The additional use of a cell saver has not further reduced blood requirements but it improved the patient's perioperative water balance.

Adolescent↗
PubMed1988

Lumbosacral plexus lesions: correlation of clinical signs and computed tomography.

Neurological signs and computed tomographic morphology were compared in 60 patients. The primary neurological deficit was most commonly located in the sacral (n = 31) or lumbar plexus (n = 23) and was most commonly caused by a neoplasm (n = 40). In 78% of the patients it correlated with the lesions detected by computed tomography (CT). CT reliably demonstrates extraspinal mass lesions, but only moderately well predicts functional signs.

Fecal Incontinence↗
PubMed1985

[Surgical treatment of type I and II dissecting aortic aneurysms].

Over a period of 15 years, 89 patients (70 male, 19 female) aged 15-76 (mean 48) underwent surgery for acute (64) or chronic (25) dissecting aneurysm type I or II. Early mortality was 18% (16 patients); 8 patients died late (2.8% per year); 8 patients had to be reoperated because of late complications on the aorta. Although very often it is not possible to remove or replace the entire diseased aorta, the goal of the operative procedure is to reduce the risk of rupture by replacing the entry site with a dacron graft. Late reoperation has to be considered if dissection progresses or a new aneurysm develops.

Adolescent↗
PubMedDate not supplied

A convenient and flexible approach for introducing linkers on bifunctional chelating agents.

The synthesis of a protected bifunctional analog of ethylenediaminetetraacetic acid (EDTA) is described. The molecule contains an aminobenzyl moiety that allows the easy attachment of the chelating agent to a wide variety of groups. Examples of reaction with the C-termini of two peptides are given. In the following paper, the two peptides are used to study the enzymatic cleavage of metal chelates from a monoclonal antibody.

Amino Acid Sequence↗