Biomedical subjects

C Weiss

Publications and source records attributed to C Weiss.

At least 55 records · Page 3Linked to original sources

PubMed1998

Acute effects of haemodialysis on cutaneous microcirculation in patients with peripheral arterial occlusive disease.

BACKGROUND: Peripheral arterial occlusive disease (PAOD) is an increasing problem in patients on maintenance haemodialysis. Alterations in microvascular perfusion accompany and complicate arteriosclerosis of large vessels and might contribute to the disease process. The aim of the study was to investigate the acute effects of haemodialysis on the cutaneous microcirculation in 26 patients with and without intermittent claudication. METHODS: Cutaneous perfusion was assessed by measuring transcutaneous oxygen pressure (tcPO2) and skin temperature at the dorsum of the foot. After standardized cooling to 15 degrees C of a 2cm2 skin area, the time to reach baseline skin temperature was evaluated as an indirect parameter of reactive hyperaemia. RESULTS: During haemodialysis, tcPO2 dropped significantly in both groups. The decrease in tcPO2 was more pronounced in patients with PAOD (20% vs 15% n.s.). The reactive hyperaemia response was reduced significantly in patients with intermittent claudication indicated by a prolonged time to reach baseline skin temperature after cooling. Values of tcPO2 and reactive hyperaemia did not reach baseline values at the end of haemodialysis in either group. CONCLUSIONS: Nutritive skin perfusion is impaired during haemodialysis. These changes are more pronounced in patients with PAOD and persist after dialysis. These findings are relevant for the treatment of patients with vascular disease on maintenance haemodialysis.

Adult↗

PubMed1998

Coagulation and fibrinolysis after moderate and very heavy exercise in healthy male subjects.

To examine the relationship between exercise intensity and activation of coagulation and fibrinolysis, we measured markers of thrombin, fibrin, and plasmin formation in 12 male subjects (mean 24+/-4 yr (SD)) before and after running on a treadmill for 1 h at two different intensities corresponding to moderate (82% maximal heart rate (HR), 68% VO2max) and very heavy (94% maximal HR, 83% VO2max) exercise. During moderate exercise plasma levels of tissue plasminogen activator (t-PA) antigen rose from 3.7+/-0.5 (mean+/-SE) to 14.6+/-1.8 ng x mL[-1] (P < 0.01) and of plasmin-alpha-antiplasmin (PAP) complexes from 2.1+/-0.3 to 4.2+/-0.7 nmol x L[-1] (P < 0.01), whereas prothrombin fragment 1+2 (PTF1+2), thrombin-antithrombin III (TAT) complexes and fibrinopeptide A (FPA) did not change significantly. In response to very heavy exercise, mean plasma levels of t-PA antigen and PAP complexes exceeded the upper limit of normal values 2.5- (P < 0.01) and two-fold (P < 0.01), respectively, while significant increases of plasma levels of PTF1+2 (P < 0.01), TAT (P < 0.05), and FPA (P < 0.01) occurred within the range of normal. We conclude that in healthy young individuals, exercise-induced activation of coagulation is well balanced by activation of the fibrinolytic system, since moderate exercise results in increased plasmin formation only, while at very heavy exercise generation of plasmin seems to exceed that of thrombin and fibrin.

Adult↗

PubMed1998

Coagulation and thrombomodulin in response to exercise of different type and duration.

PURPOSE: The present study was conducted to evaluate the role of the duration of exercise and the impact of the exercise type for exercise-induced activation of coagulation. METHODS: Eleven male triathletes were subjected to stepwise maximal (17 min) and 1-h maximal exercise in swimming, cycling, and running. Changes of hemostatic variable sand of plasma thrombomodulin, a marker of endothelial cell activation, were monitored. RESULTS: Irrespective of the type of exercise, alterations in markers of thrombin (prothrombin fragment 1 + 2, thrombin-antithrombin III complexes) and fibrin formation (fibrinopeptide A) were more pronounced after 1-h exercise than after stepwise maximal exercise. Hemostatic parameters rose to the highest levels after running resulting in substantial fibrin formation as indicated by fibrinopeptide A increasing from 1.33 ng.mL-1 to 2.25 ng.mL (P < 0.05) after 1-h exercise testing. Significant changes of plasma thrombomodulin were detected exclusively after running with increases from 38.2 ng.mL-1 to 44.2 ng.mL-1 (1 h, P < 0.01). CONCLUSIONS: The data demonstrated that prolonged exercise is necessary for exercise-induced activation of coagulation resulting in thrombin and fibrin formation and suggested that endothelial cell activation possibly due to mechanical factors associated with running might play a role.

Adult↗

PubMed1998

Interleukin-9 promotes allergen-induced eosinophilic inflammation and airway hyperresponsiveness in transgenic mice.

Human atopic asthma is a complex heritable inflammatory disorder of the airways associated with clinical signs of allergic inflammation and airway hyperresponsiveness. Recent studies demonstrate that the degree of airway responsiveness is strongly associated with interleukin (IL)-9 expression in murine lung. To investigate the contribution of IL-9 to airway hyperresponsiveness, and to explore directly its relationship to airway inflammation, we studied transgenic mice overexpressing IL-9. In this report we show that IL-9 transgenic mice (FVB/N-TG5), in comparison with FVB/NJ mice, display significantly enhanced eosinophilic airway inflammation, elevated serum total immunoglobulin E, and airway hyperresponsiveness following lung challenge with a natural antigen (Aspergillus fumigatus). These data support a central role for IL-9 in the complex pathogenesis of allergic inflammation.

Allergens↗

PubMed1998

Neutrophil function in peripheral arterial occlusive disease: the effects of prostaglandin E1.

The role of polymorph nuclear neutrophils (PMN) in limb ischemia and reperfusion has been recognized only in recent years. The present study aimed to investigate the systemic and local (in femoral venous blood) effects of intra-arterially or intravenously applied prostaglandin E1 (PGE1) on systemic and ischemia-induced local changes in neutrophil function. Thirty patients with intermittent claudication were randomly assigned to intra-arterial or intravenous infusion of prostaglandin E1 (10 microg i.a. or 15 microg i.v. over 30 min). Prior to infusion femoral arterial and venous blood samples were obtained from the predominantly affected leg under resting conditions and immediately after a 3-min period of ischemia induced by suprasystolic thigh compression. After 24 h additional blood samples were obtained at baseline, following infusion of prostaglandin E1, and again after another 3-min period of ischemia following the prostaglandin E1 infusion. Intra-arterially administered prostaglandin E1 caused an increase in the PMN count by 3.5 +/- 2% (p<0.05) and a decrease in free oxygen radical production by 13 +/- 8% (p<0.05) measured by whole blood chemiluminescence. Additionally, a trend for lower PMN filterabilities (9 +/- 12%, NS) was observed. Intra-arterially infused prostaglandin E1 significantly reduced the ischemia-induced decrease in neutrophil filterability (arterial and venous blood difference after ischemia -- control: 22 +/- 17% (p<0.05); IA PGE1: 8 +/- 11% (NS), each compared to baseline). Intravenously administered prostaglandin E1 showed similar systemic effects as the intra-arterial application, but did not affect the ischemia-induced changes in neutrophil filterability. In conclusion, prostaglandin E1 reduces PMN activation in patients with peripheral arterial occlusive disease.

Aged↗

PubMed1998

[Electrophysiologic study and endocardial ECG mapping in the detection of causes of heart rhythm disorders].

Accessory pathways and ectopic heart focuses tachycardias are often cause of tachycardias. AV reentry tachycardias are great diagnostic and therapeutic problems. Using the electrophysiological investigation and ECG mapping, there is possibility to find out abnormal pathways and ectopic atrial and ventricular focuses. In electrophysiological investigations we can use bipolar, threepolar and multipolar electrodes and mapping electrodes, as well. The ablation catheter is introduced by transveins way in electrophysiological investigation of right atrium and ventricle, and via the femoral artery to the left atrium and ventricle. We investigated 45 patients, who are hospitalised at the Cardiology clinic Ependorf, of the University in Hamburg Accessory pathways were found out in 37 (82.22%) patients. Successful RF catheter ablation was done in 34 (91.89%) patients and unsuccessful in 3 (8.10%). Ectopic focuses were found out in patients with left ventricle aneurysm. It was indication for aneurysmectomia in two cases and for implantation of antitachycardia pacemaker in one case.

Adult↗

PubMed1998

[The Richard classic nail (intramedullary hip screw, IMHS) as unreamed intramedullary nail in osteosynthesis treatment of pertrochanteric fractures].

The treatment of 85 patients with pertrochanteric femoral fractures (average age 82.3 years) with the Richards classic nail allowed full weight-bearing in 94.1% and unreamed implantation in 91.8%. In the follow-up period (11.2 months post-operatively) few complications (1.2% infections, 1.2% cutting out) could be documented. The Sanders and Regazzoni score revealed that 66% of the patients reached their preoperative status again. Statistical analysis showed a negative influence of patient age and fracture type on the postoperative walking ability.

Aged↗

PubMed1997

Attenuated progression of coronary artery disease after 6 years of multifactorial risk intervention: role of physical exercise.

BACKGROUND: It was the aim of this study to assess the long-term effects of physical exercise and low-fat diet on the progression of coronary artery disease. At the beginning of the study, 113 male patients with coronary artery disease were randomized to an intervention group (n=56) or a control group (n=57); 90 patients (80%) could be reevaluated after 6 years. METHODS AND RESULTS: Patients in the intervention group (n=40) showed a reduction in total serum cholesterol (6.03+/-1.03 versus 5.67+/-1.01 mmol/L; P<.03) and triglyceride levels (1.94+/-0.8 versus 1.6+/-0.89 mmol/L; P<.005) and maintained their initial body mass index (26+/-2 versus 27+/-2 kg/m2; P=NS), but results were not statistically different from the control group (n=50) (total serum cholesterol, 6.05+/-1.02 versus 5.79+/-0.88 mmol/L; triglycerides, 2.25+/-1.28 versus 1.85+/-0.96 mmol/L [both P=NS]; body mass index, 26+/-2 versus 28+/-3 kg/m2 [P<.0001]). In the intervention group, there was a significant 28% increase in physical work capacity (166+/-59 versus 212+/-89 W; P<.001), whereas values remained essentially unchanged in the control group (165+/-51 versus 170+/-60 W; P=NS; between groups, P<.05). In the intervention group, coronary stenoses progressed at a significantly slower rate than in the control group (P<.0001). Energy expenditure during exercise was assessed in a subgroup; patients with regression of coronary stenoses spent an average of 1784+/-384 kcal/wk (approximately 4 hours of moderate aerobic exercise per week). Multivariate regression analysis identified only physical work capacity as independently contributing to angiographic changes. CONCLUSIONS: After 6 years of multifactorial risk intervention, there is significant and persistent improvement in lipoprotein levels and physical work capacity, which results in a significant retardation of disease progression. These beneficial effects appear to be largely due to chronic physical exercise.

Adult↗

PubMed1997

[Resuscitation in ventricular fibrillation as the first manifestation of Bland-White-Garland syndrome in adulthood].

CASE REPORT: This case presents a 31-year-old male patient with anomalous origin of the left coronary artery from the pulmonary trunc. First symptom of the disease was a survived sudden cardiac death. Subsequent angiographic and echocardiographic studies demonstrated the anomalous origin of the left coronary artery from the pulmonary artery. There were no signs of prior myocardial infarction. After reimplantation of the anomalous originating left coronary artery no myocardial ischemia could be detected in the thallium-201 myocardial imaging, which was present before surgical correction. In this case myocardial ischemia was the only potential triggering mechanism responsible for the sudden cardiac death, which was no longer detectable after surgical correction. Therefore no additional pharmacological and nonpharmacological antiarrhythmic treatment was initiated. CONCLUSION: In rare cases the first manifestation of Bland White Garland syndrome in the adult patient could be sudden cardiac death due to ventricular fibrillation.

Adult↗

PubMed1997

GroES binding regulates GroEL chaperonin activity under heat shock.

Chaperonins GroEL14 and GroES7 are heat-shock proteins implicated in the molecular response to stress. Protein fluorescence, crosslinking and kinetic analysis revealed that the bond between the two otherwise thermoresistant oligomers is regulated by temperature. As temperature increased, the affinity of GroES7 and the release of bound proteins from the chaperonin concomitantly decreased. After heat shock, GroES7 rebinding to GroEL14 and GroEL14GroES7 particles correlated with the restoration of optimal protein folding/release activity. Chaperonins thus behave as a molecular thermometer which can inhibit the release of aggregation-prone proteins during heat shock and restore protein folding and release after heat shock.

Adenosine Triphosphatases↗

PubMed1997

Expression of the pair-rule gene odd Oz (odz) in imaginal tissues.

odd Oz (odz), the only pair-rule gene that does not encode a transcription factor, is expressed in every imaginal disc and imaginal tissue of Drosophila melanogaster, as assessed by immunocytochemical staining for the protein and by odz-enhancer trap line staining. The eye imaginal disc expresses odz at the morphogenetic furrow, in R7 photoreceptor cells, and in adepithelial cells. Genetic evidence indicates that odz is involved in furrow progression, and in R7 cell RTK receptor tyrosine kinase signalling. Expression in the wing pouch appears in a complex pattern that displays a symmetry axis at the dorsal-ventral boundary. In other dorsal thoracic disc sites, Odz appears at specific points of prospective thoracic integument and prospective proximal structures of the wing and haltere. Expression in the leg and antennal discs is strongest in prospective proximal segments at sites homologous between these discs. In addition, odz appears in sensory mother cells (SMCs) in all of the above-mentioned discs. This recurrence indicates the general importance of odz in the development of the peripheral nervous system (PNS), which complements the finding that it is expressed in the CNS, with striking optic lobe staining. odz must be involved in cellular signalling in pleiotropic roles in varied pathway contexts.

Animals↗

PubMed1997

Preoperative D-dimer plasma assay is not a predictor of clinical outcome for patients with advanced ovarian cancer.

D-dimer (DD) plasma levels are significantly higher in patients with ovarian cancer than in those with benign ovarian masses. The aim of this paper is to assess whether preoperative DD plasma assay has a prognostic relevance for 35 patients with advanced ovarian cancer receiving platinum-based chemotherapy. Preoperative DD levels ranged from 162 to 3720 ng/ml. The 25, 50, and 75% quartiles of DD levels were 1600, 1894, and 2069 ng/ml, respectively. Preoperative DD levels correlated neither with the common clinicopathological prognostic variables nor with the disease status at the end of first-line chemotherapy. Survival was related to residual disease after initial surgery (> or =2 cm vs <2 cm, P = 0.003), but not to preoperative DD levels. In conclusion, the present data seem to show that preoperative DD plasma assay is not a predictor of clinical outcome for patients with advanced ovarian cancer.

Adult↗

PubMed1997

Subthreshold stimulation in the region of the slow pathway during atrioventricular node reentrant tachycardia: correlation with effect of radiofrequency catheter ablation.

OBJECTIVES: The present study sought to investigate the role of subthreshold stimulation in patients with atrioventricular node reentrant tachycardia (AVNRT) undergoing catheter ablation of the slow pathway. BACKGROUND: Subthreshold stimulation applied to right atrial sites has been demonstrated to terminate AVNRT but has not been correlated with the effects of radiofrequency current delivery to the area of the slow pathway. METHODS: Eighteen patients with common AVNRT were prospectively included in the study. Sustained AVNRT was reproducibly inducible in all patients (cycle length 334 +/- 58 ms). Anatomic and electrogram guided mapping of the slow pathway was started posteroseptally and continued to more midseptal sites if required. Subthreshold stimulation (3 s, up to 5 mA) during induced AVNRT was performed at each site eligible for slow pathway ablation until termination of AVNRT or capture was observed. Irrespective of the effect of subthreshold stimulation, radiofrequency current was delivered at each site after exclusion of catheter dislocation. RESULTS: Termination of AVNRT due to block of the anterograde slow pathway induced by subthreshold stimulation occurred without apparent capture in 15 of 18 patients. This phenomenon was exclusively observed at successful posteroseptal to midseptal ablation sites. Subthreshold stimulation was not successful at any of 30 target sites with ineffective radiofrequency current delivery. Thus, subthreshold stimulation identified successful target sites with 83% sensitivity and 100% specificity. Atrioventricular node reentrant tachycardia was abolished in all patients after a median of two (range one to nine) radiofrequency current applications. CONCLUSIONS: Subthreshold stimulation delivered to the region of the slow pathway terminates AVNRT with high safety and efficacy. High sensitivity and specificity for prediction of the effect of radiofrequency current application suggest that subthreshold stimulation may become a new tool for identifying target sites for slow pathway ablation.

Adult↗

PubMed1997

Characterization of the myosin heavy chains of avian adult fast muscles at the protein and mRNA levels.

High resolution anion-exchange chromatography of myosin subfragment-1 in avian fast muscles revealed five fast heavy chains (I-V) expressed in muscle-specific patterns. Sequence analysis of a unique peptide established that the proteins differed in primary structure and suggested correlation with heavy chain genes identified independently by Robbins and coworkers. The identities of the isoforms and their expression patterns were confirmed at the mRNA level by a reverse-transcription, 5'-anchored PCR procedure. The fast white pectoralis major muscle possessed heavy chain I, the posterior latissimus dorsi muscle, of similar fibre type, expressed heavy chains I, III and IV. The fast red adductor superficialis muscle expressed either, or both, of heavy chains II and IV. The lateral gastocnemius muscle, of mixed fibre type, expressed heavy chains II-V. In general, heavy chains I, III and V appeared to be favoured in fast white fibres, while heavy chains II and IV were characteristic of fast red fibres. These results imply a greater subtlety of fast muscle function than has previously been appreciated.

Amino Acid Sequence↗

PubMed1997

Tachyarrhythmias following coronary artery bypass graft surgery: epidemiology, mechanisms, and current therapeutic strategies.

The distribution pattern of perioperative complications of coronary artery bypass graft surgery (CABG) is currently changing, due to the fact that it has become a routine operation with an increasing proportion of patients older than 70 years. Supraventricular and ventricular tachyarrhythmias are among the most commonly observed postoperative adverse events following CABG. The aim of this review is to give an update on epidemiology and mechanisms of postoperative arrhythmias and to present current diagnostic tools and therapeutic strategies.

Anti-Arrhythmia Agents↗

PubMed1997

Triazine dyes inhibit HIV-1 entry by binding to envelope glycoproteins.

We have attempted to purify envelope (Env) glycoproteins of human immunodeficiency virus (HIV) from the culture supernatants of CHO-Sec cells that secreted truncated 140-kDa precursor and mature 120-kDa Env glycoproteins. The concentrated culture supernatants were applied to a column coupled with cibacron blue 3GA (CB3GA) to separate albumin from the Env proteins because CB3GA, a triazine dye, has been known to have a high affinity to albumin. Unexpectedly, Env proteins as well as albumin bound to the column, and the bound Env proteins were eluted by increasing the ionic strength using KCl. Gp120 was eluted at 0.5-0.9 M of KCl, while a higher concentration (0.9-1.5 M) was necessary for the elution of gp140. The agarose gel coupled with reactive red 120 (RR120), another triazine dye with similar characteristics, also retained both Env proteins, and the bound Env proteins could be eluted in a similar manner. In addition, these agents inhibited syncytium formation caused by HTLV-IIIB and HTLV-IIIMN. Inhibition was also seen when a virus-free fusion assay between Env protein expressed in CHO cells and fluorescent labeled SupT1 cells were used. These findings indicate that triazine dyes bind to the functional regions of Env proteins of HIV-1 that play important role(s) for HIV infection.

Albumins↗

PubMed1997

Mapping of the coronary sinus and great cardiac vein using a 2-French electrode catheter and a right femoral approach.

INTRODUCTION: Local electrograms recorded from the coronary sinus and great cardiac vein provide important information for the diagnosis of various arrhythmias and identification of target sites for ablation of left-sided accessory pathways. One limitation of present techniques is the inability, in many cases, to probe the great cardiac vein at the anterior mitral annulus. We tested the feasibility of a new technique for catheterization of the coronary sinus and great cardiac vein by means of a small-diameter electrode catheter advanced via a right femoral approach through an angiography catheter. METHODS AND RESULTS: Of 22 patients (12 men and 10 women; ages 44.5 +/- 13.4 years) undergoing radiofrequency ablation of a supraventricular tachycardia, cannulation of the coronary sinus orifice using a 6-French 1L or 2L Amplatz catheter was achieved in 20 patients (91%) within 0.9 +/- 0.6 minutes; after cannulation, a 2-French octapolar electrode catheter with a soft radiopaque tip and a 3-mm interelectrode distance could be advanced in all 20 patients through the guiding catheter to the great cardiac vein in the anterior region of the AV sulcus within 0.8 +/- 0.7 minutes. Atrial and ventricular local potentials were recorded all along the mitral annulus during sinus rhythm, atrial and ventricular pacing, or supraventricular tachycardia. Variation of local potential amplitude never exceeded 20% of the mean and presented similar stability at all annular regions. The arrhythmogenic substrate was identified in all patients. Of 18 patients with 21 left-sided accessory pathways, an accessory pathway potential could be recorded at the ablation site by one or more adjacent epicardial electrode pairs in 10 pathways. No procedure-related complications were observed. CONCLUSIONS: The technique introduced in this study proved feasible in 91% of patients. Its main advantages are the simplicity and rapidity of coronary sinus cannulation and the ability to advance the electrode catheter to the anterior cardiac vein. In addition, closely spaced bipolar electrograms resulted in enhanced atrial, ventricular, and accessory pathway potential resolution.

Adult↗

PubMed1997

Decreased plasma glutamine level and CD4+ T cell number in response to 8 wk of anaerobic training.

The purpose of the present study was to investigate the role of plasma amino acids and glutathione (GSH) on the absolute number of leukocyte and lymphocyte subpopulations in response to different training programs. Healthy untrained subjects were randomly assigned to an 8-wk aerobic (AET) or anaerobic (ANT) exercise training program. Absolute number of cell counts did not significantly change in AET, whereas a decrease of CD4+ T cell counts (P < 0.05), a fall in cells expressing CD45RA+ antigen (P < 0.05), and a marked increase in CD8+ T cell numbers (P < 0.01) were noted in ANT at the end of the training period compared with baseline values. Furthermore, ANT demonstrated a marked rise (P < 0.001) in plasma glutamate from 27.6 +/- 2.8 to 49.8 +/- 5.2 microM and a considerable reduction (P < 0.001) of the plasma glutamine pool from 713 +/- 22 to 601 +/- 30 microM after 8 wk of training. The decrease in glutamine showed a strong positive correlation to the individual loss of CD4+ T cells (r = 0.67, P < 0.001). AET demonstrated a rise (P < 0.05) in GSH from 20.7 +/- 2.5 to 28.1 +/- 1.5 nmol/mg protein at terminal examination. In conclusion, our data indicate impairment of the number and activity of CD4+ T cells in response to 8 wk of ANT, which might be linked to metabolic factors such as glutamine.

Adult↗