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Biomedical subjects

P Vogt

Publications and source records attributed to P Vogt.

At least 91 records · Page 5Linked to original sources
PubMed1997

Effect of high intensity exercise training on central hemodynamic responses to exercise in men with reduced left ventricular function.

OBJECTIVES: The aim of this study was to evaluate the effects of high intensity exercise training on left ventricular function and hemodynamic responses to exercise in patients with reduced ventricular function. BACKGROUND: Results of studies on central hemodynamic adaptations to exercise training in patients with chronic heart failure have been contradictory, and some research has suggested that training causes further myocardial damage in these patients after a myocardial infarction. METHODS: Twenty-five men with left ventricular dysfunction after a myocardial infarction or coronary artery bypass graft surgery were randomized to an exercise training group (mean age +/- SD 56 +/- 5 years, mean ejection fraction [EF] 32 +/- 7%, n = 12) or a control group (mean age 55 +/- 7 years, mean EF 33 +/- 6%, n = 13). Patients in the exercise group performed 2 h of walking daily and four weekly sessions of high intensity monitored stationary cycling (40 min at 70% to 80% peak capacity) at a residential rehabilitation center for a period of 2 months. Ventilatory gas exchange and upright hemodynamic measurements (rest and peak exercise cardiac output; pulmonary artery, wedge and mean arterial pressures; and systemic vascular resistance) were performed before and after the study period. RESULTS: Maximal oxygen uptake (VO2max) increased by 23% after 1 month of training, and by an additional 6% after month 2. The increase in VO2max in the trained group paralleled an increase in maximal cardiac output (12.0 +/- 1.8 liters/min before training vs. 13.7 +/- 2.5 liters/min after training, p < 0.05), but maximal cardiac output did not change in the control group. Neither stroke volume nor hemodynamic pressures at rest or during exercise differed within or between groups. Rest left ventricular mass, volumes and EF determined by magnetic resonance imaging were unchanged in both groups. CONCLUSIONS: High intensity exercise training in patients with reduced left ventricular function results in substantial increases in VO2max by way of an increase in maximal cardiac output combined with a widening of maximal arteriovenous oxygen difference, but not changes in contractility. Training did not worsen hemodynamic status or cause further myocardial damage.

Cardiac Output↗
PubMed1997

Aortobronchial and aortoesophageal fistulae as risk factors in surgery of descending thoracic aortic aneurysms.

OBJECTIVE: Assess outcome of patients with descending thoracic aortic aneurysms complicated by aortobronchial and aortoesophageal fistulae in comparison to patients undergoing repair of aortic aneurysms without fistulae. METHODS: In a consecutive series of 145 patients (age 60 +/- 12 years) with repair of descending thoracic and thoracoabdominal aortic aneurysms, 11 patients (8%; age 63 +/- 9; NS) primarily presented for hematemesis and/or hemoptysis. In 8/11 patients (73%) an aortobronchial fistula was identified, and 3/11 patients (27%) suffered from an aortoesophageal fistula. Five of 11 patients (45%) had undergone previous aortic surgery in the same region. RESULTS: Extent of aortic segments (range 1-8) replaced was 3.1 +/- 1.4 for all versus 2.6 +/- 0.9 for fistulae (NS). Aortic cross clamp time was 38 +/- 22 min for all versus 45 +/- 15 min for fistulae (NS). Mortality at 30 days was 18/145 (12%) for all versus 16/134 (12%) without fistulae versus 2/11 (18%) with fistulae (NS). Paraparesis and or paraplegia was observed in 11/145 (8%) for all versus 10/134 (7%) without fistulae versus 1/11 (9%) for cases with fistulae (NS). Nine additional patients died after hospital discharge, seven without fistulae and two with fistulae (days 80, and 120) bringing the 1-year mortality up to 23/134 (17%) without fistulae versus 4/11 (36%) with fistulae (NS). Further analysis shows that the 1-year mortality accounts for 1/8 patients (13%) with aorto-bronchial fistulae versus to 3/3 patients (100%) with aorto-esophageal fistulae (esophageal versus bronchial fistula: P = 0.018; esophageal versus no fistula: P = 0.006). CONCLUSIONS: Outcome of patients suffering from descending thoracic aortic aneurysms complicated by aorto-bronchial fistulae can be similar to that without fistulae, whereas for cases complicated by aorto-esophageal fistulae the prognosis seems to remain poor even after successful hospital discharge.

Aged↗
PubMed1997

VATS resection of an oesophageal leiomyoma in a patient with neurofibromatosis Recklinghausen.

A series of reports in the literature suggest an association of neurofibromatosis Recklinghausen with intestinal tumors as carcinoids, leiomyomas and leiomyosarcomas. We present a case of a 23-year-old man with severe cutaneous manifestation of neurofibromatosis. Dysphagia was the main symptom. CT scan suggested the diagnosis of an oesophageal leiomyoma. The oesophageal muscle layers were split and the tumor was enucleated by video assisted thoracoscopic surgery (VATS). The postoperative course was uneventful. The patient was drinking liquids from day 1 and was eating a normal diet from day 3 postoperatively. He was dismissed from the hospital on the 4th postoperative day. We conclude that in patients with neurofibromatosis and oesophageal symptoms an intestinal manifestation of the disease in the oesophagus has to be considered and that VATS resection of intramural and extrinsic oesophageal leiomyomas is the treatment of choice.

Adult↗
PubMed1997

Small-cell lung cancer is characterized by a high incidence of deletions on chromosomes 3p, 4q, 5q, 10q, 13q and 17p.

The genetic mechanisms that define the malignant behaviour of small-cell lung cancer (SCLC) are poorly understood. We performed comparative genomic hybridization (CGH) on 22 autoptic SCLCs to screen the tumour genome for genomic imbalances. DNA loss of chromosome 3p was a basic alteration that occurred in all tumours. Additionally, deletions were observed on chromosome 10q in 94% of tumours and on chromosomes 4q, 5q, 13q and 17p in 86% of tumours. DNA loss was confirmed by loss of heterozygosity (LOH) analysis for chromosomes 3p, 5q and 10q. Simultaneous mutations of these six most abundant genetic changes were found in 12 cases. One single tumour carried at least five deletions. DNA under-representations were observed less frequently on chromosome 15q (55%) and chromosome 16q (45%). The prevalent imbalances were clearly indicated by the superposition of the 22 tumours to a CGH superkaryogram. In our view, the high incidence of chromosomal loss is an indication that SCLC is defined by a pattern of deletions and that the inactivation of multiple growth-inhibitory pathways contributes in particular to the aggressive phenotype of that type of tumour.

Aged↗
PubMed1997

Salivary gland-like tumors of the sellar region.

Herein we present a group of rare tumors of the sella region that have not been previously recognized. Although clinically and radiographically the tumors resemble nonfunctioning pituitary adenomas, their histologic, immunohistochemical, and ultrastructural features differ and indicate a salivary gland origin. The lesions cover a morphologic spectrum that includes cellular pleomorphic adenoma, monomorphic adenoma, oncocytoma, and low-grade adenocarcinoma of the salivary gland. All tumors except the oncocytoma were immunoreactive for cytokeratin and were negative for pituitary hormones and synaptophysin. Ultrastructural characteristics in the cases examined include hypodense stromal material, basal lamina, and tonofilament bundles. The single oncocytoma was packed with mitochondria and lacked membrane-bound secretory granules. DNA ploidy based on image analysis and MIB-1 labeling indices showed diversity within this group of tumors, with labeling indices ranging from 0.06% to 15%. The presumed origin of these rare neoplasms is from salivary gland rests related to the normal pituitary gland. Despite their varied morphology, such tumors are easily confused with pituitary adenoma. Although rare, tumors of salivary gland origin should be considered in the differential diagnosis of unusual adenohypophyseal tumors.

Adenocarcinoma↗
PubMed1997

Molecular diagnosis of bacterial endocarditis by broad-range PCR amplification and direct sequencing.

Broad-range PCR amplification of part of the 16S rRNA gene followed by single-strand sequencing was applied to samples of 18 resected heart valves from patients with infective endocarditis. The PCR results were compared with those of cultures of valves and with those of previous blood cultures. For two patients there was agreement with the cultures of the valves; for nine patients there was agreement with the previous blood cultures, which were positive, while the cultures of the valves were negative; a Streptococcus sp. and Tropheryma whippelii each were found in one patient with negative cultures (valve and blood); for two patients the cultures of the valves as well as the PCR results were negative but the blood cultures were positive; for one patient amplification was inhibited; and for two patients the PCR results were positive but the amplicons could not be sequenced. It is concluded that broad-range PCR is a promising tool for patients with culture-negative endocarditis and allows the detection of rare, noncultivable organisms.

Actinobacteria↗
PubMed1997

Cardiac metastasis of an epitheloid leiomyoblastoma of the lung.

A 73-year-old patient underwent an extended pneumonectomy on the left side on account of a central malignant epitheloid leiomyoblastoma of the upper lobe. During this operation a tumor invasion of the pulmonary vein was discovered by chance. During the postoperative course the patient suffered from a tumor-caused morbus embolicus which led to his death. The autopsy showed cardiac metastasis. Four aspects are discussed: the morphology and biology of the malignant leiomyoblastoma, the incidence of cardiac metastases and their clinical diagnosis as well as the intraoperative embolism of tumor masses during lung resections.

Aged↗
PubMed1997

Functional and biochemical analysis of angiotensin II-forming pathways in the human heart.

Blockade of the renin-angiotensin system by inhibition of angiotensin-converting enzyme (ACE) is beneficial for the treatment of hypertension and congestive heart failure. However, it is unclear how complete the blockade by ACE inhibitors is and if there is continuing angiotensin II (Ang II) formation during chronic treatment with ACE inhibitors. Indeed chymase, a serine protease, which is able to form angiotensin II from angiotensin I (Ang I) and cannot be blocked by ACE inhibitors, has been shown to be present in human heart. The goal of the present study was to evaluate the extent of renin-angiotensin system blockade and the Ang II-forming pathways in cardiac tissue of patients chronically treated with ACE inhibitors or in patients without ACE inhibition therapy. Our studies indicate an incomplete ACE inhibition in human heart tissue after chronic ACE inhibitor therapy. Moreover, ACE contributes only a small portion to the total Ang I conversion, as shown in biochemical studies in ventricular and coronary homogenates or functionally as Ang I contractions in isolated rings of coronary arteries. A serine protease was responsible for the majority of Ang II production in both the membrane preparation and Ang I-induced contractions of isolated coronary arteries. In humans, the serine protease pathway is likely to play an important role in cardiac Ang II formation. Thus, drugs such as renin inhibitors and Ang II receptor blockers might be able to induce a more complete blockade of the renin-angiotensin system, providing a more efficacious therapy.

Adult↗
PubMed1997

[Immediate and mid-term clinical and angiographic results after implantation of AVE intracoronary micro-stents in 140 consecutive cases. An experience in Lausanne].

Two hundred AVE (Arterial Vascular Engineering) microstents measuring 4 to 30 mm were implanted in 140 patients aged 62 +/- 10 years with Class II to IV angina of the Canadian Cardiovascular Society Classification. The indications were: de novo lesions (30%), suboptimal angioplasty results (54%), acute occlusion (8%) or restenosis (8%). The stents of 3.0 to 4.0 mm diameter were implanted in the left main coronary artery (1%) the left anterior descending artery (20%), the left circumflex artery (19%), the right coronary artery (44%) or a venous bypass graft (7%) after intravenous injection of 15,000 IU of heparin. Daily treatment with aspirin 100 mg and ticlopidine 500 mg was instituted from the day of the procedure. The success rate was 98.5% with only 3 technical failures. The minimal luminal diameter and percentage stenosis ranged from 0.80 +/- 0.2 mm and 74 +/- 13% before to 2.66 +/- 0.38 mm and 15 +/- 7% after the procedure in vessels with an average reference diameter of 3.05 +/- 0.35 mm. There were 3% of stent-related immediate clinical complications. In February 1996, 97 patients had survived 6 months. With a 97% follow-up rate, the clinical event rate was 18%. The angiographic follow-up rate was 70% and the restenosis rate was 27%. The authors conclude that the AVE microstents are easy to implant and provide excellent immediate angiographic results with a low complication rate.

Aged↗
PubMed1996

[Heart surgery in acute heart infarct. Indications and results].

The therapy of acute myocardial infarction has made major advances in the last 10 years. Cardiac surgeons have to adapt their strategies to the more aggressive management of acute myocardial infarction. Only in mechanical complications of acute myocardial infarction is cardiac surgery nowadays the therapy of choice. In cardiac rupture and ventricular septal defect, surgery is the only therapeutic option. In ischemic mitral regurgitation, cardiac surgery is required in the event of concomitant cardiogenic shock and pulmonary edema after intra-aortic balloon pump placement. Coronary artery bypass surgery my be indicated at low risk in patients with unstable angina pectoris when PTCA is not feasible or has failed, or in catheter emergencies.

Acute Disease↗
PubMed1996

Temporal study of the activity of matrix metalloproteinases and their endogenous inhibitors during wound healing.

The restoration of functional connective tissue is a major goal of the wound healing process. This regenerative event requires the deposition and accumulation of collagenous and noncollagenous matrix molecules as well as the remodelling of extracellular matrix (ECM) by matrix metalloproteinases (MMPs). In this study, we have utilized substrate gel electrophoresis, radiometric enzyme assays, and Western blot analyses to determine the temporal pattern of appearance and activity of active and latent MMPs and their inhibitors during the entire healing process in a partial thickness wound model. Through the use of substrate gel electrophoresis, we studied the appearance of proteolytic bands whose molecular weight was consistent with their being members of the MMP family of enzymes. Proteolytic bands whose molecular weight is consistent with both the active and latent forms of MMP-2 (72 kDa, Type IV gelatinase) were detected in wound fluid of days 1-7 after wounding. The number of active MMP-2 species detectable in wound fluid was greatest during days 4-6 after wounding. The most prominent proteolytic band detected each day migrated with a molecular weight consistent with it being the latent form of MMP-9 (92 kDa, Type V pro-collagenase). In contrast to MMP-2, the active form of this enzyme was never detected. The presence of MMP-1 (interstitial collagenase) was detected by immunoblot in the wound fluid from days 1-6 post-injury. Using a radiometric enzyme assay for collagenase inhibitory activity we have also determined the time course of activity of endogenous matrix metalloproteinase inhibitors. We have correlated these data to the known cellular events occurring in the wound during this time period as well. This study establishes a prototypical pattern of MMP appearance in normal wound healing. It may also provide potential intervention sites for the therapeutic use of inhibitors of aberrant MMP activities which characterize chronic wounds.

Animals↗
PubMed1996

[Coronary angioplasty in elderly patients].

Percutaneous transluminal coronary angioplasty (PTCA) is a widely accepted treatment of symptomatic coronary heart disease providing prompt and prolonged clinical, improvement in most patients. We have examined the value of this therapy in a group of 91 patients in their eighth decade treated by 133 consecutive angioplasties. Most patients had refractory or instable angor in spite of optimal pharmacotherapy. Multivessel disease was present in 67% and maintained left-ventricular function in 92% of the patients. The angiographic success rate of PTCA was 84%; technical failures occurred in 12% and adverse events in 14%. Two patients died. The rate of symptomatic restenosis was 24%. Survival and patients free of myocardial events were at 89% and 60%, respectively, estimated by Kaplan-Meier analysis. PTCA is an efficient and acceptable treatment for the elderly patient with severe and drug-resistant angina. Two years after PTCA the majority of patients was asymptomatic.

Aged↗
PubMed1996

Placement of multiple and different stent types for very long dissections during coronary angioplasty.

We have been investigating the safety and efficacy of multiple and different stent types placed in the unfavorable situation of a very long dissection (> 20 mm) after coronary angioplasty. We report our preliminary experience in 20 patients who were treated by the following combinations: Palmaz-Schatz and Micro stent (14 patients). Wallstent and Micro stent (4 patients); Wiktor and Micro stent (1 patient); and Palmaz-Schatz, Micro and Wallstent (1 patient). Normal distal flow was restored in all except one (no reflow phenomenon) patient and complete covering of the dissection was obtained in all but two patients. Event-free survival at 30 days was 90% (18 of 20 patients). During follow-up (mean period: 8 +/- 3 months), two patients died. Of the 18 other patients, 16 remained asymptomatic and free of complications. Symptomatic restenosis was treated by standard angioplasty in the two remaining patients. In conclusion, placement of different stent types seems a feasible, safe, and efficient treatment for very long dissections caused by standard angioplasty.

Aged↗
PubMed1996

[Anesthesia and intensive care management of severely burned children of Jehovah's Witnesses].

A 3.5-year-old girl suffered from a thermal injury affecting 37% of the body surface area. The parents, being Jehovah's witnesses, refused permission for their child to receive blood transfusions. As the haemoglobin level was only 7.5% and a necrectomy was planned, the patient was likely to need blood transfusions. Indications for transfusion were defined as clinical signs of hypoxia and/or cardiovascular instability. A judicial declaration was proposed. Hb decreased during the therapy. To stimulate the erythropoiesis erythropoietin and iron were administered. During the clinical course the anaemia worsened. First, a conservative treatment with polyvidoniodine ointment for tanning was started, to avoid an operation during the acute phase after the injury, as in this case it was thought a blood transfusion would definitely be necessary. On the 19th day after the injury a necrectomy of 10% of the body surface was necessary because of fever and leucocytosis not responding to antibiotics. The most likely cause of the symptoms was an infection of the burned area. Hb was 4.6 g/dl%. General anaesthesia was performed with midazolam, ketamine and vecuronium and mechanical ventilation. No blood transfusion was required during the operation. Vital signs were stable during the preoperative period, during anaesthesia and following the operation. There were no signs of tissue hypoxia. Peripheral oxygen saturation ranged between 98% and 100%, lactate and arterial blood gas samples were normal, and the child was awake and cooperative before and after anaesthesia. The lowest Hb was 3.3 g/dl on the 22th day after injury (3rd postoperative day). In this phase the patient was still playing and riding a tricycle. On the 45th day after injury the child was discharged home with Hb of 10.9 g/dl and reticulocytosis of 33%.

Anemia↗
PubMed1996

[Plastic soft tissue coverage in defect fractures of the tibia].

Sequential radical debridement and early soft-tissue reconstruction have considerably decreased the amputation rate, length of hospital stay, chronic osteitis, the rehabilitation period and secondary reconstructive procedures in lower leg injuries. The introduction of distraction osteotomy and "biologic osteosynthesis procedures" have led to shorter and safer osteoplastic methods. The indication, tactics and technical pitfalls of current interdisciplinary treatment options requiring modifications in soft-tissue coverage are presented.

Bone Lengthening↗
PubMed1996

Comparison of elective Wiktor stent placement with conventional balloon angioplasty for new-onset lesions of the right coronary artery.

This study compared the clinical and angiographic outcome, during a 6-month follow-up period, of 84 patients with new-onset lesions of the right coronary artery randomized to either Wiktor stent implantation (42 patients) or conventional balloon angioplasty (42 patients). At hospital discharge, three patients in each group (7%, p = not significant [NS]) reached a clinical end point. At 6 months, these proportions were 24% (10 patients with stents) and 29% (12 patients with angioplasty) (p = NS). There were no incidents of death or myocardial infarction. Despite a larger minimal luminal diameter after stenting (2.87 mm [95% confidence interval; 2.66 to 2.96 mm] vs 2.37 mm [2.23 to 2.61 mm for angioplasty] [p = 0.001]), no difference was observed at 6 months of follow-up (1.75 mm [1.43 to 2.18 mm] vs 1.74 mm [1.45 to 2.03 mm] [p = NS], respectively). Accordingly, angiographic restenosis rates were 47.5% (19 of 40 patients with stents) and 35% (14 of 40 patients with angioplasty) (p = NS). Elective stenting with the Wiktor stent and conventional balloon angioplasty are safe and immediately effective therapeutic options for symptomatic, obstructive right coronary artery disease. At 6 months of follow-up, clinical and angiographic outcome did not differ. The role of Wiktor stent placement in primary restenosis prevention remains to be determined for lesions of the right coronary artery.

Angioplasty, Balloon, Coronary↗