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Biomedical subjects

P Probst

Publications and source records attributed to P Probst.

At least 19 recordsLinked to original sources
PubMed1992

A decrease in plasminogen activator inhibitor-1 activity after successful percutaneous transluminal coronary angioplasty is associated with a significantly reduced risk for coronary restenosis.

To determine a possible relation of changes in plasma levels of plasminogen activator inhibitor 1 (PAI-1) and tissue plasminogen activator (t-PA) to the development of coronary restenosis after successful coronary angioplasty (PTCA), we followed 104 patients with a low grade residual stenosis after PTCA (less than 30%) for a period of 12 months. PAI-1 plasma levels (functional activity) and t-PA antigen were determined 1 day before PTCA and 3 days, 3 months and 6 months thereafter. Thirty-four patients (32.69%) developed angiographically proven coronary restenosis (group A) within a time range of 4-48 weeks (median 12.5 weeks) after PTCA while the remaining patients (group B) had neither clinical signs nor angiographic evidence of restenosis after 6 months. No significant differences could be demonstrated in t-PA antigen or PAI-1 activity (plasma levels between the two groups of patients the day before PTCA). During the whole observation period t-PA plasma levels were not significantly different between the two groups; however, PAI-1 plasma levels were significantly higher at 3 months and 6 months after PTCA in patients of group A (p less than 0.005). When the pattern of PAI-1 plasma levels over time (increase or decrease between two consecutive time points of blood collection) was used to discriminate between the two study groups only 3.5-18% of patients with a decrease in PAI-1 developed coronary restenosis within the following observation period in contrast to 25-58% of patients with an increase in PAI-1 plasma levels (p less than 0.05 to p less than 0.0005).

Aged↗
PubMed1992

Predominance of Th1-type T cells in synovial fluid of patients with Yersinia-induced reactive arthritis.

The pathogenetic mechanisms underlying the development of reactive arthritis and the functional capacities of synovial T cells specific for Yersinia enterocolitica are still unclear. In this study we have determined the cytokine secretion patterns of 24 CD4+ synovial fluid (SF)-derived T cell clones from 2 patients with Yersinia-induced reactive arthritis, 16 clones specific for different Yersinia antigens and 8 clones as controls. The clones specific for Yersinia antigens predominantly belong to the T helper cell 1 (Th1) subset with production of interferon (IFN)-gamma and interleukin (IL)-2, but no IL-4, whereas SF T cells not reactive with Yersinia antigens produce IL-2, IL-4 and IFN-gamma and thus belonged to the Th0 subset. Moreover, short-term T cell lines established from SF and peripheral blood showed the same pattern. To further analyze the functional relevance of these data we investigated the influence of IFN-gamma and IL-4 on the intracellular killing of Yersinia in a human glioblastoma cell line. Our data show that the Th1 cytokine IFN-gamma promotes intracellular killing of Yersinia, whereas this effect is antagonized by the Th2 cytokine IL-4. Furthermore, the Th2 cytokine IL-10 inhibited the antigen-specific proliferative response and IFN-gamma and IL-2 production by the Th1 cells. These results provide insight into the antibacterial mechanisms at work in reactive arthritis after infection with Yersinia enterocolitica and, for the first time, reveal the cross-regulatory properties of cytokines derived from Th1 and Th2 cells in a human immune response to bacterial antigens.

Adult↗
PubMed1992

Stimulation of synovial fluid mononuclear cells with the human 65-kD heat shock protein or with live enterobacteria leads to preferential expansion of TCR-gamma delta+ lymphocytes.

T lymphocyte responses to heterologous or self 65-kD heat shock protein (hsp) have been implicated in the pathogenesis of various forms of arthritis. To delineate the relationship of 65-kD hsp to different synovial fluid (SF) T cell subsets, we stimulated synovial fluid (SFMC) and peripheral blood mononuclear cells (PBMC) from patients with different inflammatory rheumatic diseases and from healthy controls with human or mycobacterial 65-kD hsp, tetanus toxoid (TT), heat-killed or live Yersinia enterocolitica. Phenotyping of the resulting T cell lines revealed an increase of up to 97% TCR-gamma delta+ lymphocytes in the 65-kD hsp-stimulated SF-derived lines. This expansion of TCR-gamma delta+ cells was less pronounced with cultures of PBMC. A preferential expansion of TCR-gamma delta+ cells was also shown after SFMC stimulation with live, but not with heat-killed Yersinia or with TT. We conclude that a common mechanism is involved in the selective expansion of TCR-gamma delta+ lymphocytes upon SFMC infection with live Yersinia or upon contact with 65-kD hsp. Out of a panel of TCR-gamma delta+ T lymphocyte clones (TLC) derived from a human 65-kD hsp-stimulated line, only a minority of TLC proliferated weakly upon restimulation with this antigen in the presence of autologous monocytes, whereas TCR-alpha beta+ TLC responded vigorously to the human 65-kD hsp and in some cases also cross-recognized the mycobacterial hsp homologue and/or heat-killed Yersinia. This implies that additional factors or cells may be present in the milieu of SFMC cultures that propagate the expansion of TCR-gamma delta+ cells in response to 65-kD hsp or live bacteria.

Cell Line↗
PubMed1991

The influence of the presence of collaterals on restenoses after PTCA.

To assess the influence of collaterals on the long-term follow-up after successful percutaneous transluminal coronary arteriography (PTCA), 120 consecutive patients were studied. Of these, 104 (87%) had an adequate reangiogram and were included. At the time of PTCA the collaterals were estimated by a scoring system. In addition, the coronary wedge pressure was measured in 49 patients six months after PTCA, a follow-up angiogram was performed, and the patients were split up into a group with restenoses (stenosis greater than 50%), 34 patients (32.7%); and a group without restenoses (stenosis less than 50%), 70 patients (67.3%). A total of 35 patients (30.7%) had collaterals. A comparison between both groups showed no significant differences in clinical parameters (age, angina duration, vessel involvement, lipids, blood sugar, and blood pressure), and stenoses-related parameters (degree of stenoses, eccentricity, balloon size, inflation pressure, dissection, gradient after dilatation, and residual stenoses). Patients with collaterals had a significantly higher incidence of restenoses than those without collaterals (45.7% vs. 26.1%, p less than 0.05). Patients with wedge pressure of less than 45 mmHg (n = 30) had a significantly lower restenosis rate (23.3%) than patients with a coronary wedge pressure of greater than 45 mmHg (n = 19) (restenosis rate 52.6%). It is concluded that the presence of collaterals indicates a high restenosis rate after PTCA within 6 months.

Adult↗
PubMed1991

Synovial fluid-derived Yersinia-reactive T cells responding to human 65-kDa heat-shock protein and heat-stressed antigen-presenting cells.

Humoral and cellular immune reactions to heat-shock proteins have been implicated in the pathogenesis of arthritis. Heat-shock proteins occur in bacteria as well as all eukaryotes and have been highly conserved during evolution. Cross-reactivity between bacterial and human heat-shock proteins induced at the site of inflammation may underlie the pathogenesis of some forms of arthritis. In order to test this hypothesis, we raised and cloned a Yersinia-specific T cell line from the synovial fluid lymphocytes of a patient with Yersinia-induced reactive arthritis. From this line we obtained a CD4+ T cell clone that proliferated in response to Yersinia antigens and both to the mycobacterial and the human 65-kDa heat-shock protein. This T cell clone also proliferated in response to autologous heat-stressed antigen-presenting cells as well as to synovial fluid mononuclear cells from the inflamed joint, thus showing true autoreactivity against endogenously synthetized self-antigen. These results demonstrate the induction of an autoimmune T cell response by a natural bacterial infection and support the important role of heat-shock proteins in the pathogenesis of immune-mediated arthritis.

Adult↗
PubMed1991

Identification of a subgroup of Graves' disease patients at higher risk for severe ophthalmopathy after radioiodine.

We have analyzed retrospectively the records of 89 patients with Graves' disease who were treated with radioiodine between 1980-88 and whose ophthalmopathy was recorded in a uniform manner initially and after 5 and 12 months. Moreover information on progression of eye disease was obtained by telephone for all patients after an average of 72 months. Pretreatment endocrine ophthalmopathy (class greater than or equal to 1 of classification of American Thyroid Association) was present in 34% of the patients. Eight patients developed proptosis over 20 mm, 7 patients severe ophthalmopathy (classes 4 to 6), 5 patients required special treatment for eye disease. Among the 30 patients with initial ophthalmopathy, severe ophthalmopathy (5 of 30; p less than 0.05) and proptosis greater than 20 mm 16 of 30; p less than 0.05) developed in significantly more cases than in patients with no pretreatment ophthalmopathy. The data suggest that hyperthyroid patients with pretreatment ophthalmopathy are at risk for developing severe ophthalmopathy after 131I treatment.

Eye Diseases↗
PubMed1991

Plasma propafenone concentration in the evaluation of anti-arrhythmic efficacy.

The anti-arrhythmic drug efficacy of oral propafenone therapy (300 mg to 900 mg per day) was studied in relation to propafenone and hydroxy-propafenone plasma concentrations in 70 outpatients (46 males, 24 females, mean age 57 +/- 12 years) followed up for 24 +/- 32 months. On average 1.7 plasma concentration measurements were performed per patient. The arrhythmias were effectively controlled in 32 patients, but in another 32 patients propafenone therapy was ineffective; in six patients the evaluation was unclear. The therapy was effective in 66% of patients with ventricular premature beats, in 50% with complex ventricular arrhythmias, in 40% with ventricular tachycardia and in 20% with supraventricular tachycardia. Fifty per cent of patients with coronary heart disease and electrical disease, but only 20% with dilated cardiomyopathy and Wolff-Parkinson-White syndrome were effectively treated. Measurement of peak plasma propafenone levels performed 4.5 +/- 2 h after oral drug administration revealed no statistically significant dose-plasma concentration relation. Optimal propafenone drug efficacy was documented at propafenone plasma concentrations ranging from 0.20 to 0.60 micrograms/ml (63% of patients considered as effectively treated). There was a trend to decrease propafenone efficacy at plasma concentrations below 0.20 micrograms/ml and above 0.60 micrograms/ml. Analysis of hydroxypropafenone identified four patients as poor metabolizers with unusually high propafenone and low hydroxypropafenone plasma concentrations; only one of these four patients showed drug efficacy. Monitoring of propafenone and hydroxypropafenone plasma concentrations was a practical procedure to assess patient's compliance, to identify poor metabolizers and to guide anti-arrhythmic drug therapy.

Adult↗
PubMed1991

Determinants of subsidiary ventricular pacemaker suppression in man.

To investigate the relative contribution of the duration and rate of overdrive to subsidiary ventricular pacemaker suppression, in six patients with complete heart block after His-bundle ablation, ventricular overdrive stimulation studies were performed. The studies, which were spread over a mean follow-up period of 745 days, were carried out invasively with a temporary lead (one patient) as well as noninvasively with the implanted pacemakers and chest wall inhibition (five patients). The overdrive pacing rate was increased in steps of 10 beats/min, and the pacing duration was 15, 30, 60, 90, and 120 seconds at each level. A recovery period of 2 minutes was allowed after each overdrive stimulation. Incremental ventricular overdrive stimulation at increasing pacing durations consistently caused progressive suppression of ventricular impulse formation. Nonparametric variance analysis demonstrated a significant (P less than 0.0001) influence of both the pacing rate and duration on ventricular recovery time. Nonlinear regression showed an exponential increase in recovery time with incremental pacing rate and a biphasic increase in recovery time with incremental pacing duration. Beyond a pacing duration of 60 seconds ventricular impulse suppression was primarily dependent upon the pacing rate. A nonlinear regression model was applied to predict the number of beats required for return of the escape rhythm toward prepacing control values. The predicted maximum mean number of beats was 15.4 +/- 5.9 and independent of the rate and duration of pacing, although, the initial temporary instability of the escape rhythm was directly related to the degree of overdrive.

Adult↗
PubMed1991

Transient myocardial perfusion abnormalities during cold provocation test in patients with arterial hyperreactivity.

The effect of peripheral cold provocation on myocardial perfusion was evaluated utilizing thallium-201 perfusion imaging in 13 selected patients with arterial hyperreactivity (Raynaud's phenomenon: n = 8; migraine: n = 6) and angiographically documented coronary artery spasm. Eleven out of 13 subjects with coronary arterial spasm--but none of a group of patients with obstructive coronary artery disease--had transient myocardial perfusion defects during cold provocation. The localization of transient perfusion abnormalities during myocardial scintigraphy correlated with the myocardial areas distal to the spontaneous or ergonovine-induced coronary arterial spasm detected by angiography. Transient reduction of tracer uptake during cold provocation and normalization of myocardial perfusion by redistribution imaging was paralleled by areas of hypokinesia observed during the test by contrast ventriculography (n = 8). The described findings in the coronary system during peripheral cold pressor test occurred independently of the presence of Raynaud's phenomenon, and without achieving the ischemic threshold.

Adult↗
PubMed1991

[Depersonalization and déjà vu experiences: prevalences in nonclinical samples].

According to the relevant psychological and psychiatric literature, depersonalization and déjà vu experiences are usually viewed as symptoms of severe psychiatric or neurological disorders, especially in schizophrenia, depression and epilepsy. Studies of these phenomena in non-clinical populations are rate. In this article we present the results of several epidemiological investigations. On the basis of survey and interview research, quantitative and qualitative aspects of both phenomena were assessed, as well as the relations with personality variables like emotionality. The results indicate prevalence rates up to 80 percent in non-clinical populations. Based on epidemiological considerations, the question of differentiation between clinical and non-clinical forms of depersonalization and déjà vu is discussed.

Adolescent↗
PubMed1991

[Recanalization of an iliac artery occlusion from the contralateral side using "low-speed rotational angioplasty"].

This paper demonstrates the applicability of "low-speed rotational angioplasty" in antegrade direction for recanalization of the common iliac artery. After recanalization, a 4-mm PTCA balloon was used to dilate in antegrade direction using a PTCA exchange wire. After 5 weeks the femoral artery could be punctured and a residual stenosis dilated in retrograde direction.

Angioplasty, Balloon↗
PubMed1991

[Time-limited contacts with psychosomatic-psychotherapeutic ambulatory care. I. Retrospective evaluation by patients].

Despite of the relevance of psychosomatic-psychotherapeutic outpatient services there is a lack of empirical studies concerning their effectiveness and compliance from the patients' point of view. This study describes the retrospective judgements of a maximum of three outpatient consultations, given by 125 patients after a mean follow-up period of 14 months. These patients completed a comprehensive questionnaire, comparable with instruments used in follow-up studies of longterm psychotherapies. The questionnaire covered demographic data, a detailed description of the consultations (including the atmosphere of the contact and the therapeutic alliance), their consequences as well as the present life situation and -quality. The results first indicate that patients who refused their participation in the study received more unspecific recommendations by the therapist, and were more commonly referred by other clinics. The judgements of the consultations were predominantly negative. Patients criticized for example a lack of activity by the therapist and of practical advice. The overall rate of compliance (i.e. number of patients who followed the therapist's recommendations) was 49%. Compliance was higher with respect to individual therapy and lowest with respect to inpatient psychotherapy. As far as the present life situation was concerned, the patients answers indicate a slight decrease of their complaints as well as an increase of life quality as compared to the time of the consultation. Potential reasons for the negative view of time limited contacts with a psychosomatic outpatient unit are finally discussed.

Adolescent↗
PubMed1991

[Time-limited contacts with psychosomatic-psychotherapeutic ambulatory care. II. Potential determinants of compliance with therapeutic recommendations].

In a detailed analysis of the data from a follow-up study with 125 patients of a psychosomatic outpatient unit, possible determinants of the utilization of therapeutic recommendations (which was seen as an indicator of compliance) have been analysed. The overall compliance-rate in the sample was 49%. Comparisons of the patients who were compliant or noncompliant (61 vs 37) revealed that demographic as well as diagnostic characteristics hardly differentiated between the two groups. The compliance-rate seems to be higher in patients who had been judged as motivated by their therapist during the time of their contacts with the unit. Besides that, the perception of the atmosphere of the contacts as well as the therapeutic alliance during a maximum of three consultations differed between both groups. Patients who were compliant assessed their life quality more positively at the time of the follow up than the other group. In a second step of the analysis, an attempt was made, by means of cluster analyses, to investigate the relationship between the compliance-rates, and the mode of referral as well as diagnostic characteristics on the one, the judgement of qualitative aspects of the consultations on the other hand. The analysis of the first relationship indicated a tendency for noncompliance in older patients and those suffering from addictions, whereas compliance seemed to be high in younger patients who came to the consultation of their own accord. Multivariate analyses further confirmed the significance of the therapeutic alliance for the prediction of compliance-rates and the importance of several other qualitative aspects of the contacts.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Psychological↗
PubMed1990

Plasminogen activator inhibitor-1 levels in patients with chronic angina pectoris with or without angiographic evidence of coronary sclerosis.

Increased plasma levels of plasminogen activator inhibitor-1 (PAI-1) have been shown to exist in 40 to 60% of patients with stable coronary artery disease and have been suggested to be responsible for the development of coronary thrombotic complications. However, it is also discussed whether PAI-1 elevation might mainly be due to variables like increased age or to reactive mechanisms caused e.g. by the chest pain itself. To exclude age dependent or pain related influences, age-matched patients with stable angina pectoris (NHYA II) and angiographically proven coronary artery disease (CAD, n = 16) or without evidence for coronary sclerosis (variant angina, n = 10; angina-like syndrome with normal coronary angiogram, n = 5; non-CAD, n = 15) have been investigated for their plasma PAI-1 activity and t-PA antigen levels. The mean PAI activity in CAD patients (17.5 U/ml) was significantly higher than in non-CAD patients (9.6 U/ml) (p less than 0.0001). In the CAD patients no significant variation in plasma PAI-1 values could be demonstrated when related to the extent of the disease or to a history of previous myocardial infarction. t-PA antigen was also elevated in CAD patients as compared to the non-CAD group (p less than 0.02). The results suggest therefore a strong correlation between coronary artery disease itself and elevated levels of components of the plasma fibrinolytic system.

Angina Pectoris↗
PubMed1989

Heparin induced increase of t-PA antigen plasma levels in patients with unstable angina: no evidence for clinical benefit of heparinization during the initial phase of treatment.

Patients with unstable coronary artery disease were randomly treated either with a combination therapy consisting of nitrates and calcium-channel blockers without or with addition of clinical grade heparin administered subcutaneously; in order to evaluate the effect of heparin treatment on the fibrinolytic system, tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) plasma levels were related to the clinical course of the disease. In heparinized patients thrombin time was prolonged more than 3-fold the normal range indicating effective heparin treatment. Heparinization led to a significant increase in t-PA antigen plasma levels (p less than 0.0001) within approximately four hours while PAI-1 activities remained unaltered. However, the measurable increase of the anticoagulant and pro-fibrinolytic activities of heparin did not result in a short-term benefit for the heparinized patients because the number of further ischemic attacks per patient during the observation period of three days was not different between the two study groups.

Aged↗
PubMed1989

[Radiological methods for visualization of the urinary tract].

The methods of radiologic investigation of the urinary tract have radically altered. Sonography has established itself as the basic method of demonstrating the size and shape of the kidney. Ultrasound reliably identifies cysts among renal tumors. It is increasingly used as the primary method in the search for nephrolithiasis or ureteral stones. Urography offers the highest resolution for the delineation of pathologic changes in the renal pelvis. It is no longer available as a screening method in suspected renovascular hypertension. CT serves to clarify doubtful sonographic renal findings. It is the method of choice for staging of renal tumors and the definition of parenchymal as well as perirenal damage after trauma. Angiography, especially as regards the diagnostic value of digital subtraction angiography, is the diagnostic method of choice in suspected renovascular hypertension. The diagnostic value of magnetic resonance imaging in nephrology and urology cannot yet be finally assessed.

Angiography↗
PubMed1989

Hemodynamic effects of mexiletine and disopyramide after cardioplegic arrest.

To study the hemodynamic side effects of mexiletine and disopyramide when administered before cardioplegic arrest 15 dogs underwent sham cardiac surgery with a 90-min period of aortic cross-clamping. 5 dogs served as control, 5 were given 8 mg/kg/day mexiletine and another five 11 mg/kg/day disopyramide for 1 week before surgery. On the day of surgery a continuous infusion was started. After reperfusion treated animals exceeded their preischemic blood pressure and regained their preoperative cardiac output. Compared to control animals left ventricular work was higher in the treated animals after reperfusion. The two tested type I antiarrhythmics tend to add to myocardial protection when given before cardioplegic arrest and do not exhibit negative inotropic side effects.

Animals↗