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Biomedical subjects

W Braun

Publications and source records attributed to W Braun.

414 records · Page 23Linked to original sources
PubMedDate not supplied

Prevalence of antibodies to human herpesviruses and hepatitis B virus in patients at different stages of human immunodeficiency virus (HIV) infection.

The results of antibody assays for viruses of the herpes group (HSV, EBV, VZV and CMV) and for hepatitis B virus (HBV) were retrospectively evaluated in 439 HIV-seropositive patients classified into different stages of HIV infection. The prevalence of specific IgG, IgM and IgA antibodies in these groups was compared with that of a control group of HIV-negative unselected hospital patients. Antibodies to herpes viruses and HBV were more prevalent amongst HIV-seropositives, especially LAS and AIDS patients than in controls. However, marked differences were found only with CMV-IgG and anti-HBc-IgG, both with a comparatively low prevalence in HIV-negative persons (64.5% and 23.2%). Significantly more seropositives were found among asymptomatic HIV carriers (83.3% and 50%) and still more in patients with full-blown AIDS (95.4% and 82.5%). The increased frequency of CMV and HBV antibodies, already seen in asymptomatic HIV patients reflects their higher risk for sexually transmitted infections. Moreover, IgA antibodies to CMV were detected in 25.4% of LAS and 37.3% of AIDS patients, respectively, but only in 7.6% of the controls. Elevated CMV-IgA titres were found exclusively in HIV-infected persons. The differences in the antibody patterns found in this cross-sectional study may reflect the progression of the HIV disease. However, prospective follow-up studies are required to assess the value of these markers as indicators of prognosis in HIV-infected subjects.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Detection of cytomegalovirus in bronchial lavage and urine using a monoclonal antibody to an HCMV early nuclear protein.

Laboratory diagnosis of 24 cases of human cytomegalovirus (HCMV) infection in patients with the acquired immunodeficiency syndrome, renal transplant recipients and premature infants was achieved. These results were obtained by a rapid, sensitive and versatile HCMV-antigen detection method, which combined cell culture and immunoperoxidase staining with a monoclonal antibody to an HCMV "early" nuclear protein. The results were compared with HCMV isolation by the conventional cell culture method. While some of these immunocompromised patients lacked a significant antibody response, infective HCMV could be detected in the patients' urine and bronchial lavage fluid. The diagnostic procedure took no longer than 24 h. The usefulness of this antigen test for an effective diagnosis in immunocompromised individuals was demonstrated. We recommend routine analysis of various specimens, since recent developments in chemotherapy of HCMV infection and the risks of long-term damage demand immediate management of the patients concerned.

Adult↗
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Improvement of serological diagnosis of human cytomegalovirus infection in renal transplant recipients by testing for specific immunoglobulin E by ELISA.

The kinetics of human cytomegalovirus (HCMV)-specific immunoglobulin E (IgE), M (IgM), A (IgA) and G (IgG) were studied in 421 sera obtained from 19 renal allograft recipients by enzyme-linked immunosorbent assay (ELISA). Cytomegalic inclusion disease (CID) occurred in 11 (57.9%) patients. HCMV infection was diagnosed in all (100%) of these patients by testing for specific IgE. In contrast, increased levels of IgM and IgA class antibody against HCMV were detected in only 45.5% and 18.2% patients suffering from primary or recurrent HCMV infection, respectively. Concerning the time interval between the onset of clinical symptoms and the first positive test, no significant differences in the kinetics of HCMV-specific immunoglobulins E, M, A and G were observed. Elevated specific IgE levels persisted for longer time intervals than the other immunoglobulin classes. As shown by the present study, specific IgE proved to be a more reliable serologic marker than IgM and IgA for the serologic detection of HCMV infection in renal allograft recipients.

Adult↗
PubMedDate not supplied

Arrhythmias and infarction in the ischemic pig heart are not mediated by xanthine oxidase-derived free oxygen radicals.

Xanthine oxidase activities of pig myocardium and blood during and following myocardial ischemia were measured using HPLC, and electrochemical detection of hypoxanthine, xanthine and uric acid. Myocardial ischemia was produced by occluding the anterior descending coronary artery two-thirds of the way from its origin. There was no accumulation of either xanthine or urate in the ischemic pig myocardium during occlusion periods of 90 min, but there was a substantial accumulation of hypoxanthine. Similarly, there was no increase in myocardial xanthine or urate during the 30 min reperfusion following coronary artery occlusion periods of 15, 30, 60 or 90 min. Following in vitro incubation at pH 8 of myocardial homogenates or blood with either hypoxanthine or xanthine and NAD, no urate production was detectable. In contrast, significant amounts of xanthine and/or urate were produced, following addition of xanthine oxidase to the reaction mixtures. Additional in vitro experiments showed that the following pig tissues were lacking xanthine oxidase activity: left and right atrial appendage, left and right ventricle, interventricular septum, anterior descending and circumflex coronary arteries, ascending aorta, lung, and blood. Large amounts of xanthine oxidase (9.3 +/- 1.8 SEM mU/g wet weight, n = 7) were found in pig liver. In the ischemic pig heart, transmural infarction developed within 60 min of ischemia. Ventricular arrhythmias and fibrillation occurred most frequently within 45 min of ischemia and within seconds after reperfusion. These results showed that the pig heart and blood were xanthine oxidase deficient, suggesting that xanthine oxidase-derived free oxygen radicals were not involved in the cytotoxic and arrhythmogenic effects brought about by myocardial ischemia and/or reperfusion in the pig.

Animals↗
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Effect of brief periods of paced ventricular tachycardia on coronary blood flow in dogs before and after graded coronary stenosis.

The effect of short bouts (1 min) of electrically induced ventricular tachycardias (VT) of increasing rates (160-240/min) was studied in 8 anesthetized dogs before and after graded constrictions of the left anterior descending (LAD) and the circumflex (CCA) coronary arteries. In the absence of coronary stenosis, paroxysmal VT caused a significant decrease in tension-time index (TTI), coronary blood flow (CBF) and coronary vascular resistance (CVR). Single and combined coronary stenosis caused relatively small alterations of the VT-induced depression of the systemic hemodynamics but reversed the effect of paroxysmal VT on the CVR. In the presence of single 90% LAD stenosis, VT resulted in an increase in CVR-LAD and a decrease in F-LAD associated with a fall in CVR-CCA and a rise in F-CCA. Combination of 90% LAD plus 70% CCA stenosis abolished the compensatory fall of CVR-CCA resulting in a pronounced reduction of F-CCA during VT. The results support the concept that in the presence of severe coronary stenosis brief paroxysmal ventricular tachycardias do increase myocardial nutritional demand but rather decrease nutritional supply.

Animals↗
PubMedDate not supplied

Role of some components of ischemia in the genesis of spontaneous ventricular arrhythmias.

The importance of single components of ischemia including hypoxia, lactic acidosis, high potassium, and sympathetic stimulation to the spontaneous occurrence of ventricular arrhythmias was studied in chloralose-anesthetized cats using systemic and local intracoronary administration. Hypoxia and acidosis provoked no spontaneous arrhythmias regardless of systemic or regional administration. Systemic or local hyperpotassemia induced regularly ventricular ectopic activity including recurrent ventricular tachycardias that were characterized by a sudden onset and termination and by a stable rate. Stimulation of the left, right or bilateral stellate ganglia failed to provoke ventricular arrhythmias during hypoxia or acidosis and had also no influence on the initiation or rate of K+-induced ventricular tachycardias. The results indicate that high extracellular K+ may be the predominant arrhythmogenic factor of the components of ischemia we studied and that sympathetic ganglia stimulation does not affect K+-induced ventricular tachycardia.

Acidosis↗
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Antibodies against human CMV-induced "early" antigens detected by immunoblotting are not exclusively associated with active infection.

We investigated the correlation between the prevalence of antibodies against human cytomegalovirus (HCMV) "early" proteins and the state of infection. Two hundred and twenty-eight HCMV-IgG-positive (HCMV late-antigen ELISA) sera, drawn from subjects with active and non-active HCMV infections, were tested for specific IgG antibodies against HCMV "early" antigens by a Western blotting micromethod. Applying virus strain AD-169, we found antibodies to HCMV "early" antigens in 59% of all cases, irrespective of origin. Subjects with an elevated risk of cytomegalic inclusion disease (renal transplantation patients, AIDS patients) revealed significantly broader immune reactions when compared with healthy HCMV-antibody carriers. However, in follow-up studies we detected one patient who lacked an immune response to HCMV "early" antigens during active infection and subsequent convalescence. Our results indicate that active HCMV infection is not necessarily associated with the formation of antibodies against "early" antigens. Moreover, these antibodies may persist during non-active infection.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

[Stabilization of interligamentous valgus procedure in tibial head osteotomy using staples].

In patients with painful post-traumatic or idiopathic varus gonarthrosis we perform interligamentous valgization osteotomy of the tibial head if arthroscopy shows the lateral joint surfaces to be in sufficiently good condition. Between 1989 and 1993, a total of 75 osteotomies were performed in symptomatic varus gonarthrosis, including 52 cases of idiopathic and 22 cases of post-traumatic gonarthrosis, and one case following infection of the knee joint. The corrections were stabilized exclusively with osteotomy staples (e.g. Richards). The stability thus achieved permits mobilization without plaster with partial loading up to 15 kg from the first postoperative day on. If the indication is adhered to, the operation correctly performed and the complication rate low, we regard the described procedure as appropriate for treating monocondylar varus gonarthrosis.

Adult↗
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[Effect of shock waves on the strength of connection between bone and polymethylmethacrylate. An in vitro study of human femur segments].

The increasing number of revision surgery for failed total arthroplasty including the most difficult aspects of cement removal has lead to various developments of new instruments and techniques to facilitate this procedure. In this in vitro study the effect of extracorporeal shockwaves on the bone-cement interface under this view was investigated. At first the pressure reduction of bounding shockwaves in their progress through compounds consisting of cortical bone-PMMA and cancellous bone-PMMA by means of a needle pressure probe was measured. In the second part of the experiments the mechanical and morphological effects of ESW on the PMMA-Bone-Interface of human femoral segments was tested. Using bone cement cadaveric femoral segments were implanted with stainless steel rods within the medullary canal and the PMMA-Bone-interface was treated with ESW. After treatment the segments were examined mechanically, radiologically and by microscopy. Between the treated and the control group no difference was found which could give any a reference to the disruption of the Cement-Bone-Interface caused by ESW. However, there were observations which indicated that ESW induces a increasing risk of intravasation of bone marrow. Considering these facts ESW seems not to be a good clinical adjunct in revision surgery.

Biomechanical Phenomena↗
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[15N]methacetin urine test to measure liver function: methodology for application in pediatrics.

A simple, noninvasive test is proposed to measure the activity of the hepatocellular monooxygenase system in vivo. Elimination rates of the stable isotope 15N are measured in urine after an oral dose of the 15N-labeled phenacetin homologue [15N]methacetin. Different forms of obtaining and expressing results are investigated in order to determine optimum methodology and differentiation for clinical application in pediatrics. The best discriminating power and reliability of results are seen with the measurement of 15N elimination half-life. For follow-up, a more easily measured parameter--eliminated dose over 9 h--is sufficient. In the latter case, only total nitrogen and 15N contents of a collective urine sample are measured.

Acetamides↗
PubMedDate not supplied

Aminotransferase levels and silymarin in de novo tacrine-treated patients with Alzheimer's disease.

BACKGROUND: Silymarin is a well-known hepatoprotective agent. Tacrine, the first drug marketed for Alzheimer's disease (AD), induces an elevation of serum liver transaminase prohibiting an effective dosage in many patients. This 12-week randomised, double-blind, placebo-controlled study was undertaken to evaluate the ability of silymarin to antagonise or prevent the hepatotoxic effects of tacrine and to analyse its action on tacrine efficacy and tolerability. METHODS: Outpatients suffering from mild-to-moderate dementia of the Alzheimer type were randomly assigned to two treatment groups: tacrine + silymarin and tacrine + placebo. The study was double-blind for silymarin and open for tacrine and was conducted in 22 French neurology and geriatric centres. Silymarin (420 mg/day) was given first (1 week) and tacrine was added at 40 mg/day for 6 weeks, then increased to 80 mg/day (6 weeks). Serum ALAT was the main evaluation criterion (> upper limit of normal, ULN). Serum ASAT as well as adverse side effects and cognitive performance assessed by MMSE and the Syndrome Kurtz test (SKT) were secondary evaluation criteria. Null hypotheses were evaluated with Fisher's exact test. FINDINGS: 222 patients were recruited and received silymarin and tacrine (110 patients) or placebo and tacrine (112 patients). 28 patients dropped out; 217 were included in the intent-to-treat analysis. No statistical difference was observed between the two groups for serum ALAT (p = 0.39). Fewer patients had ALAT levels >5 ULN in the silymarin group (-33.3%). Side effects and notably gastrointestinal disorders were much less frequent in the silymarin group. Cognitive performance remained unchanged in both groups. INTERPRETATION: Silymarin does not prevent tacrine-induced ALAT elevation but does reduce the rate of gastrointestinal and cholinergic side effects without any impact on cognitive status. As a consequence, silymarin (420 mg/day) could be co-administered with tacrine to improve tolerability in the initial phases of AD treatment.

Aged↗
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The influence of renal function on plasma concentration, urinary excretion and antihypertensive effect of guanfacine.

18 hypertensive patients with a glomerular filtration rate (GFR) between 3.8 and 113ml/min received guanfacine as single intravenous and multiple oral dose treatment. Mean plasma concentrations of guanfacine on the fifth day or oral treatment ranged from 6.5 to 8.6ng/ml in patients with normal renal function (GFR > 90ml/min), as well as in those with a moderate degree of renal impairment (GFR 30 to 10ml/min) and in uraemic patients (GFR < 10ml/min). During guanfacine treatment plasma concentrations and fall in blood pressure did not differ in a statistically significant fashion among patients with varying degrees of renal function. Independent of renal function, in all investigated patients the elimination rate constant obtained from serum and urine values were close to 0.05h-1. Mean half-life of guanfacine was calculated to be 14h. The cumulative urinary excretion up to 48h fell from 57% in patients with normal renal function to 7.5% in uraemic patients. Thus, non-renal excretion plays an importat role in patients with impaired renal function.

Adult↗
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[Reliability of duplex sonography in non-quantitative determination of blood flow in comparison to inductive flow measurement--an in vitro study].

Using an experimental design permitting generation of a pulsatile "flow-velocity waveform" corresponding to the fetal aortic signal, the influence of measurement depth, the angle between the Doppler beam and the vessel, the high-pass filter and the extent of overlap between the "sample volume" and the vessel cross-section were studied in vitro. The Resistance Index showed the best relation to inductive flow measurement, which was defined as standard. Considering the conditions prevailing during clinical studies, good reliability is likely at angles of between 0 degrees and 60 degrees (120 degrees-180 degrees) over the entire range of measuring depths (4-13 cm) and when using 100-200 Hz high-pass filters. The magnitude and location of the sample volume does not seem to play a decisive role provided a part of it is within the sonographically imaged "vessel" and there is no likelihood of interference from vessels in the immediate vicinity in which blood flow is in the same direction.

Aorta↗