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Biomedical subjects

W Klein

Publications and source records attributed to W Klein.

At least 217 records · Page 12Linked to original sources
PubMed1994

[First aid measures by lay persons in cardiovascular arrest].

The efficiency of first aid resuscitation is affirmed by many publications. In a questionnaire of the division of Cardiology of the Department of Internal Medicine, Graz and the Styrian Heart Patient Society distributed during the course of the Graz spring fair 1993 the population was approached as to first aid in cardiac arrest. 550 subjects responded to answer this circular for assessment dividing the population statistically in 4 different age groups showing differences among male and female and country and city dwellers. It has been shown that general first aid resuscitation has been known sufficiently, whereas special cardiorespiratory procedures (such as artificial respiration or cardiac massage) were unknown to most.

Adolescent↗
PubMed1994

"Non-dipping" related to cardiovascular events in essential hypertensive patients.

About 1 third of all patients with essential hypertension reveal an impaired circadian pattern of blood pressure. This phenomenon called "non-dipping" (i.e. a lack of the normal nocturnal fall in blood pressure) is related to a higher incidence of end-organ damage such as left ventricular hypertrophy. It is the purpose of this study to evaluate, whether or not non-dipping of blood pressure may worsen the prognosis of hypertensive subjects. 116 consecutive hypertensives underwent an ambulatory blood pressure monitoring (ABPM) using the Spacelabs 2000 device. 2 groups were established: Group I (n = 87) were "dippers", group II (n = 29) "non-dippers" showing a diminished or even lack of nocturnal fall in blood pressure. No difference was seen concerning sex, mean 24-hour systolic blood pressure, systolic and diastolic causal blood pressure and heart rate. However, a significant difference in age and mean 24-hour diastolic blood pressure could be observed. In a follow-up investigation after approximately 31 months all patients and/or their physicians were contacted concerning cardiovascular events during the time since the ABPM was performed. In Group I only 1 transient ischemic attack occurred, but in group II 4 patients showed major cardiovascular events: 3 deaths occurred (2 of which caused by myocardial infarction, 1 by apoplexy), while 1 suffered from a transient ischemic attack (p < 0.001). Thus, in essential hypertension non-dipping of blood pressure is associated with an increased occurrence of cardiovascular events, and, therefore, the circadian blood pressure profile should be carefully monitored.

Adolescent↗
PubMed1994

[10-year-follow-up of patients with silent Cohn type 1 myocardial ischemia].

Prevalence of type 1 silent myocardial ischemia (SMI; completely asymptomatic patients) is reported to appear 2 to 4% of the general population. The prognosis of these patients is said to be similar to that of patients with angina pectoris. Our study investigated a 10-year follow up of silent myocardial ischemia detected by bicycle exercise testing in comparison to a comparable control group. 10 years later 127 patients were reinvestigated by bicycle ergometry, 33 patients out of the SMI-group (group A) and 84 patients out of the control group (group B). Mean age in group A was 62 +/- 7 years (range 42 to 71 years), in group B 56 +/- 7 years (range 29 to 69 years). After 10 years there was no statistical significant difference between the 2 groups on using beta-blockers, calciumchannel-blockers and nitrates, on arterial hypertension, diabetes mellitus, smoking history and positive family-history as well as in total cholesterol, HDL- and LDL-cholesterol, triglycerides, blood glucose and uric acid. 1 patient of A and 2 of B died from a sudden cardiac death, 2 of A and 7 of B survived a myocardial infarction, 11 of A and 11 of B developed angina pectoris (p < 0.05). A statistical significant difference was found in the ergometric working capacity (maximal workload in Watt) between the 2 groups (p < 0.001) that did not change over the 10 years, the control group worked better in both investigations. SMI type 1, detected by bicycle ergometry seems to be only a risk factor for developing "loud ischemia" (= angina pectoris) but not for "hard events". A routine screening of completely asymptomatic persons with bicycle ergometry seems to have no prognostic relevance.

Adult↗
PubMed1994

[Follow-up of fracture healing--indications and clinical relevance of direct radiographic magnification in comparison with conventional roentgen imaging].

Comparison of 83 magnification radiographs with corresponding conventional X-rays showed that direct radiographic magnification (DIMA) yielded additional information in 39 cases (47%), which had implications for the treatment in 19 cases (22.9%). In 11 cases callus was first visualized in magnification radiography; the earliest evidence of callus was found 14 days after surgery. Since magnification radiography means the region that can be examined is smaller, conventional radiographs were necessary in 32.5% of cases to find the position of the fracture in long bones. For statistical evaluation interobserver analysis was performed, anatomical and pathological structures being graded according to four levels. Magnification radiography proved superior in all structures examined. Magnification radiography can be recommended as an additional method to monitor fracture healing. Computed radiography was used together with magnification radiography to reduce the radiation dose and to perform image processing including simulation of conventional technique and edge enhancement. DIMA is a valuable tool in the evaluation of fracture stability and in the adjustment of distraction rates in limb-lengthening procedures.

Adult↗
PubMed1994

[Coronary heart disease as the initial manifestation of primary hyperparathyroidism].

Due to unstable angina pectoris coronary arteriography was performed in a 57 year-old female, showing diffuse 3-vessel disease; aortocoronary bypass surgery was recommended. During routine pre-operative examination hypercalcemia, as well as an elevated value of parathormone were observed. Ultrasonography of the parathyroid glands showed two enlarged cranial glands. In a simultaneous surgical procedure 4 bypass grafts were performed and 4 hyperplastic parathyroid glands were removed, one of which was re-operated as an autotransplantation in the left musculus adductor magnus. Histological examination showed water clear cell hyperplasia of the parathyroid glands. Though the patient had suffered from stomach and duodenal ulcers and nephrolithiasis over several years, primary hyperparathyroidism was diagnosed only after angiographically proven coronary artery disease.

Combined Modality Therapy↗
PubMed1994

[Familial dysalbuminemic hyperthyroxinemia in long-term amiodarone treated patients].

A serum sample of an outpatient, under long-term amiodarone (AM) treatment was submitted for routine checkup of thyroid function parameters. It revealed the pattern of euthyroid dysalbuminemic hyperthyroxinemia. Since no results have been published so far covering the influence of amiodarone on the specific thyroxine binding proteins, we undertook a prospective study to investigate 28 amiodarone patients, comparing these with a series of age and sex matched euthyroid subjects. Not one amiodarone patient showed changed radio-T4 distribution against the normal group. Yet, in 3 relatives of the propositus, familial screening revealed the typical pattern of thyroid function tests and of T4 distribution in radio immune ice gel electrophoresis, respectively, proving familial dysalbuminemic hyperthyroxinemia syndrome. Thus, it is most likely that this syndrome has been prevalent already prior to the amiodarone administration and consequently amiodarone was of no influence on thyroxine transport protein patterns.

Adult↗
PubMed1994

[Physical activity at intermediate altitude by healthy probands and patients with coronary sclerosis].

For the majority of the population, exposure to altitudes higher than 2000 m above sea level constitutes a situation of pronounced stimulation of the organism. The question comes in of the health relevance of physical activity at intermediate altitudes for the healthy subjects, but above all for people with heart problems. At first, there is an acute adaption on the cardiovascular and the respiration system as well as the system of oxygen carriage, until the chronic adaption processes of the same systems are completed. Doubtlessly, these adaption processes at intermediate altitudes and in particular training in such regions considerably improve the endurance capacity under conditions of the kind mentioned. However there is little evidence, for an absolute improvement of the maximal aerobic capacity. As a rule, the effects of adaption to higher altitudes can also be expected in patients with coronary sclerosis. But a lowered level of capacity must be taken into account in these cases. Accordingly, the medication as well as the intensity of stress should be adapted to altered conditions of this kind. Training intensity must be reduced according to altitude, and any treatment for angina, must be intensified. It may be necessary to re-determine the appropriate training intensity as well as the dosage in pharmacotherapy by ergometric methods to match the new requirements. However, when a comparison is tried to kinetotherapy under normal conditions, an immediate therapeutical effect of exposition to higher altitudes appears to be at least doubtful.

Acclimatization↗
PubMed1994

[Distal diaphyseal fracture of the humerus].

Fractures of the distal humeral diaphysis are rare and have not been reported very often in the literature, although therapeutic management is more difficult than that of midshaft humeral fractures. As they are so near to the elbow, these fractures are not suitable for bracing, because pro/supination movements cannot be eliminated. Muscular forces, especially of the pronator teres muscle, force the fracture into a varus position with every supination movement. From 1974 to 1990 we treated 174 fractures of the humeral diaphysis by operative means; 31 of these were located in the distal third. According to the AO classification, 8 were graded as less difficult type A fractures, 15 as type B and 7 as type C fractures. In 22.6% of the patients primary radial palsy was present. In all, 15 fractures were treated by plating, 9 with Hackethal's bundle nails and 6 with monolateral fixators. These last patients had sustained either multiple trauma or severe soft tissue injury or both. The plated cases included 1 with non-union and with superficial infection, both in type C comminuted fractures. In 1 case the fracture was not suitable for plating, and in the other case technical errors led to failure. In the 9 cases treated with Hackethal nails there were no complications. The advantage of the method is that the nails are inserted far distant from the fracture site. Anatomical reduction is not necessary, which means there is no danger of devitalizing fragments; the technique is also quick. In the "fixator" group, we saw 1 case of non-union and 1 of refracture, both following compound fractures.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone Plates↗
PubMed1994

[Toxoplasmosis peri-myocarditis as initial manifestation of highly malignant non-Hodgkin's lymphoma].

A case report of a 28-year-old mother of two children with FUO is presented. Physical examination revealed an anemic and febrile woman, who lost 10 kg of weight during the past 3 months. Furthermore, two lymphatic nodes with diameters below 1 cm were detected at the neck and inguinal region. A search for origin of fever including evaluation of foci, malignancies and laboratory investigations was primarily unsuccessful. At day 7 after admission a pericardial murmur could be heard. Echocardiography revealed a pericardial effusion, which increased up to 4 cm during the following days, leading to hemodynamic impairment and asystole. Immediate CR was successful, pericardial effusion was aspirated. Looking for etiology of fever the presence of IgM-antibodies against toxoplasma gondii by an ELISA test was possible. Therefore, toxoplasmosis was diagnosed and a treatment-regimen comprising pyrimethamin and sulfadiazin was initiated. Because of the threat to life and very high titers of C-reactive protein, antibiotic therapy (imipenem) was given additionally. An immunologic impairment was excluded by normal ratio of CD4:CD8 of lymphocytes, normal HIV-test and a nonsuspicious Jamshidi-biopsy of the bone marrow. However, in week 9 after admission lymphatic node-tumors suddenly appeared at the neck and pulmonary hilus. After diagnostic exstirpation a malignant non-Hodgkin-lymphoma (T-cell-type) was diagnosed. It is concluded that in obscure pericardial effusion toxoplasmosis should be considered and that this manifestation may be a precursor of malignant non-Hodgkin-lymphoma.

Adult↗
PubMed1994

[Arthroscopic partial double meniscectomy].

Arthroscopic treatment of meniscal pathology has become a routine procedure within the last 10 years. In our patients who underwent arthroscopic surgery for multiple reasons we found 226 cases with combined lesions of the medial and lateral menisci. Eliminating the patients with instabilities, chondral lesions grade IV and general diseases like rheumatoid arthritis and those who had had surgery previously, 71 patients were left. Forty-four (62%) were male and 27 (38%) female. The average age was 52 years. The lesion was located in the right knee in 41 cases (58%) and in 31 cases (42%) in the left one. The duration of symptoms was more than 3 months in most cases. Eleven patients (15%) had a trauma in their history. A standardized interview according to the Tapper and Hoover score was carried out in each patient. Out of the 77 patients with partial double meniscectomy we were able to examine 55 patients. According to the Tapper and Hoover score the following results were evaluated: 17 patients (31%) rated excellent. In 28 cases (51%) the result was good. 8 patients (15%) showed fair results. The main cause in this group was a slight feeling of instability and a mild loss of function (lack of flexion < 5 degrees, lack of extension < 10 degrees). Two patients (3.6%) were rated poor. Of the patients 89% were satisfied with this surgical procedure and would choose it again. Only 11% (n = 6) were not satisfied with the outcome of the procedure and would prefer arthrotomy. Our follow-up study indicates that arthroscopic double partial meniscectomy gives good results.(ABSTRACT TRUNCATED AT 250 WORDS)

Arthroscopy↗
PubMed1993

Stereoselective features of (R)- and (S)-atenolol: clinical pharmacological, pharmacokinetic, and radioligand binding studies.

In a randomized, double-blind, cross-over study in 12 healthy volunteers, the effects of single oral doses of 100 mg rac-atenolol were compared during exercise to those of equal amounts of the optically pure enantiomers, i.e., 50 mg (R)- and 50 mg (S)-atenolol. The mean rate pressure product decreased with rac-atenolol (-37%; P < 0.01) and half-dosed (S)-atenolol (-35%; P < 0.01) to the same extent, whereas (R)-atenolol caused no effect. Radioligand binding studies in beta-adrenergic receptors of the guinea pig heart yielded a eudismic ratio of 46 for (S)- to (R)-atenolol. The mean AUCs, maximal plasma concentrations, and plasma half-lives of the enantiomers were similar regardless of whether they were administered as optically pure enantiomers or as racemic mixture. On the other hand, the AUC of (R)-atenolol was 1.08-fold greater (P < 0.01) than that of the (S)-enantiomer. The reason for this finding remains unclear. We conclude that only (S)-atenolol, but not (R)-atenolol, contributes to the beta-blocking effect of currently used rac-atenolol since the same effect can be elicited with the (S)-enantiomer alone.

Adult↗
PubMed1993

Correlation between inflection of heart rate/work performance curve and myocardial function in exhausting cycle ergometer exercise.

The heart rate/work performance (fc/W) curve is usually S-shaped but a flattening at the top is not always seen. By means of radionuclide ventricular scintigraphy, the left ventricular ejection fraction (LVEF) of 15 sports students was investigated. The behaviour of the fc/W curve during cycle ergometry with increasing exercise intensities was examined. During exercise, the LVEF showed a distinct initial increase reaching roughly constant values at stress levels below-maximum, and sometimes even falling again. The inflections of the fc/W curve and left ventricular ejection fraction/performance curve (LVEFPC) were calculated from a second degree polynomial fit. From this function, the slopes of the tangents at the points of aerobic threshold and maximum performance were calculated together with the differences of the angles as a measure of the fc/W curve and LVEFPC inflections. It follows that the fc/W curve inflection became less pronounced or was even absent altogether when the decrease in LVEF towards the end of the ergometer exercise became more distinct. A significant negative correlation was found between the existence and extent of the fc/W curve inflection and the stress-dependent myocardial function, expressed as the inflection of the LVEFPC (P < 0.01, r = 0.673). Thus, it would seem that the absence of a fc/W curve inflection was related to a diminished stress-dependent myocardial function.

Adult↗
PubMed1993

Bilateral vulvar basal cell carcinomata.

Vulvar basal cell carcinoma is rare, accounting for less than 5% of vulvar neoplasms. There is great variation in the clinical appearance of this neoplasm, which occurs most commonly in older women. Metastasis seldom occurs, but the tumor may extend deeply into local tissues. We report the first case of bilateral vulvar basal cell carcinomata in a 66-year-old woman who had received radiotherapy for urethral carcinoma 35 years earlier. Both tumors were treated with Mohs micrographic surgery and have not recurred after 13 years.

Aged↗
PubMed1993

Induction of the lambda receptor is essential for effective uptake of trehalose in Escherichia coli.

Trehalose transport in Escherichia coli after growth at low osmolarity is mediated by enzyme IITre of the phosphotransferase system (W. Boos, U. Ehmann, H. Forkl, W. Klein, M. Rimmele, and P. Postma, J. Bacteriol. 172:3450-3461, 1990). The apparent Km (16 microM) of trehalose uptake is low. Since trehalose is a good source of carbon and the apparent affinity of the uptake system is high, it was surprising that the disaccharide trehalose [O-alpha-D-glucosyl(1-1)-alpha-D-glucoside] has no problems diffusing through the outer membrane at high enough rates to allow full growth, particularly at low substrate concentrations. Here we show that induction of the maltose regulon is required for efficient utilization of trehalose. malT mutants that lack expression of all maltose genes, as well as lamB mutants that lack only the lambda receptor (maltoporin), still grow on trehalose at the usual high (10 mM) trehalose concentrations in agar plates, but they exhibit the half-maximal rate of trehalose uptake at concentrations that are 50-fold higher than in the wild-type (malT+) strain. The maltose system is induced by trehalose to about 30% of the fully induced level reached when grown in the presence of maltose in a malT+ strain or when grown on glycerol in a maltose-constitutive strain [malT(Con)]. The 30% level of maximal expression is sufficient for maximal trehalose utilization, since there is no difference in the concentration of trehalose required for the half-maximal rate of uptake in trehalose-grown strains with the wild-type gene (malT+) or with strains constitutive for the maltose system [malT(Con)]. In contrast, when the expression of the lambda receptor is reduced to less than 20% of the maximal level, trehalose uptake becomes less efficient. Induction of the maltose system by trehalose requires metabolism of trehalose. Mutants lacking amylotrehalase, the key enzyme in trehalose utilization, accumulate trehalose but do not induce the maltose system.

Bacterial Outer Membrane Proteins↗
PubMed1993

Evaluation of ketanserin in the prevention of restenosis after percutaneous transluminal coronary angioplasty. A multicenter randomized double-blind placebo-controlled trial.

BACKGROUND: Ketanserin is a serotonin S2-receptor antagonist that inhibits the platelet activation and vasoconstriction induced by serotonin and also inhibits the mitogenic effect of serotonin on vascular smooth muscle cells. METHODS AND RESULTS: We conducted a randomized, double blind, placebo-controlled trial to assess the effect of ketanserin in restenosis prevention after percutaneous transluminal coronary angioplasty (PTCA). Patients received either ketanserin (loading dose, 40 mg 1 hour before PTCA; maintenance dose, 40 mg bid for 6 months) or matched placebo. In addition, all patients received aspirin for 6 months. Coronary angiograms before PTCA, after PTCA, and at 6 months were quantitatively analyzed. Six hundred fifty-eight patients were entered into the intention-to-treat analysis. The primary clinical end point of the study was the occurrence between PTCA and 6 months of any one of the following: cardiac death, myocardial infarction, the need for repeat angioplasty, or bypass surgery. It also included the need for revascularization actuated by findings at 6-month follow-up angiography. The primary clinical end point was reached by 92 (28%) patients in the ketanserin group and 104 (32%) in the placebo group (RR, 0.89; 95% CI, 0.70, 1.13; P = .38). Quantitative angiography after PTCA and at follow-up was available in 592 patients (ketanserin, 287; control, 305). The mean difference in minimal lumen diameter between post-PTCA and follow-up angiogram (primary angiographic end point) was 0.27 +/- 0.49 mm in the ketanserin group and 0.24 +/- 0.52 mm in the control group (difference, 0.03 mm; 95% CI, -0.05, 0.11; P = .50). CONCLUSIONS: Ketanserin at the dose administered in this trial failed to reduce the loss in minimal lumen diameter during follow-up after PTCA and did not significantly improve the clinical outcome.

Adult↗
PubMed1993

Vasodilative response to hypoxia and simulated ischemia is mediated by ATP-sensitive K+ channels in guinea pig thoracic aorta.

Local vasodilation in response to hypoxia or ischemia improves perfusion and O2 supply of the affected tissue. This local vasodilation thus constitutes the most important mechanism in the prevention of ischemic cell injury. The regulation of vascular tone has mainly been attributed to changes of cytoplasmatic Ca2+ ((Ca2+)i) concentrations in vascular smooth muscle cells. The mechanism underlying these changes has not, however, been elucidated so far. Using aortic strips of guinea pigs (transversally cut in spirals; normal Tyrode, in mM: NaCl 150, KCl 4.5, MgCl2 2, CaCl2 2.5, glucose 10; buffered with 10 mM HEPES at pH 7.4; equilibrated with 100% O2 at 31 degrees C) the authors could show that metabolic blockade (glucose replaced by 10 mM 2-deoxyglucose (DOG) led to a relaxation of the preparation. Thus, in four experiments, resting tension decreased from 0.75 g by 27% +/- 12% within two hours (% of maximal contractile force developed by each preparation when depolarized with 43 mM KCl and 101.5 mM NaCl). When the same experiment was carried out in the presence of 1 mM tolbutamide (a known blocker of ATP-dependent K+ channels) in vascular smooth muscle no such relaxation could be seen (n = 4). Furthermore, in the same type of preparation, similar results have been obtained upon hypoxic relaxation (100% O2 replaced by 100% N2), where 1 mM tolbutamide also prevented vasodilation. Thus, hypoxic/ischemic vasodilation in response to glycolytic inhibition (DOG) and hypoxia (N2) is based upon the opening of K+ ATP channels and hence can be prevented by sulfonylureas (the opening of K+ ATP channels would lead to hyperpolarization (increased K+ conductance, Goldmann equation), thus diminishing the open probability of voltage-gated Ca2+ channels with subsequent vasodilation). This inhibition by sulfonylureas of vasodilative response to ischemia may also constitute the so far unknown cause of the increased cardiovascular mortality seen under sulfonylurea treatment.

Adenosine Triphosphate↗
PubMed1993

Observations on plasma ANP levels during short-term transient myocardial ischemia produced by PTCA in patients with LAD stenosis.

Ten patients with coronary artery disease and stable angina (mean age fifty-seven) were included in the study. Five of the patients had normal left ventricular function, 5 had local hypokinesia or akinesia; 8 had one-stem and 2 had two-stem disease, but all had left anterior descending (LAD) lesions ranging from 75% to 100%. Ejection fraction varied between 35% and 75% (mean 59%). Immunoreactive atrial natriuretic polypeptide (ANP) levels in the femoral vein (FV) and the coronary sinus (CS) were measured before, immediately after, and up to twenty-four hours after percutaneous transluminal coronary angioplasty (PTCA) of the LAD. ANP secretion increased by 83% (FV) and 11% (CS) within minutes after PTCA and reached control levels after thirty to sixty minutes. In patients with hypokinesia of the anterior wall, ANP secretion was significantly lower, 48% (FV) and 11% (CS) respectively. ANP secretion during PTCA was higher in patients with concomitant increase in pulmonary capillary pressure (PCP) but was also observed without an increase of PCP, suggesting ventricular ANP secretion. IN conclusion, transient myocardial ischemia leads to immediate ANP secretion even in the absence of significant pressure elevation in the left atrium. As a part of the continuous medical education program of the American College of Angiology the second part of the paper reviews the mechanisms that allow the ischemic heart to counteract the ischemic condition and thus to escape from myocardial infarction. A review of this subject is presently not available in the literature.

Angina Pectoris↗