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Biomedical subjects

W Lederer

Publications and source records attributed to W Lederer.

At least 37 records · Page 2Linked to original sources
PubMed2000

Tachyarrhythmias in a surgical intensive care unit: a case-controlled epidemiologic study.

OBJECTIVE: Incidence, types, and factors associated with new onset tachyarrhythmias (TA) in surgical intensive care patients. DESIGN: Pairwise-matched case-controlled study. SETTING: Surgical intensive care unit (ICU) with nine intensive care beds. PATIENTS: During a 1-year period, all TA patients (n = 89) were included in the study. Control patients (n = 82) without TA were matched according to age, sex, and surgical region. METHODS: TA workup included: 12-lead ECG, arterial blood gas, serum electrolyte (K+, Mg2+), and serum CK/CKMB isoenzyme analysis. Pre-existing cardiovascular and pulmonary disease, cardiovascular risk factors, preoperative regular medication, and admission SAPS were recorded in all patients. A multiple organ dysfunction syndrome (MODS) score, the presence or absence of SIRS or sepsis, and hemodynamics (MAP and CVP) before onset of TA were evaluated in TA patients, while in control patients highest MODS-score, the presence or absence of SIRS or sepsis, mean hemodynamic and laboratory values calculated from highest and lowest readings during ICU stay were used for statistical comparison. Logistic regression analysis was performed to identify variables multivariately associated with TA. RESULTS: Eighty-nine (14.8%) of 596 patients developed TA. Atrial fibrillation was most frequent (60.7%). Presence of SIRS or sepsis (adj. OR = 36.45; 95% CI: 11.5-115.5), high admission SAPS (adj. OR = 1.25/point; 95% CI: 1.08-1.44), high CVP (adj. OR = 1.27/mmHg; 95% CI: 1.09-1.48), and low arterial oxygen tension (adj. OR = 0.97/mmHg); 95% CI: 0.95-0.99) were found to be significant predictors for development of TA. CONCLUSIONS: In surgical patients hypoxia, high cardiac filling pressures, a greater degree of physiologic derangement at admission, and the presence of SIRS and sepsis are independent risk factors for the development of TA.

Aged↗
PubMed2000

Further evidence that behavioral tests and neuropeptide mRNA and tissue level alterations can differentiate between typical and atypical antipsychotic drugs.

This study was designed to compare some behavioral and biochemical effects of chronic treatment with a range of antipsychotic drugs. Gene expression of enkephalin, chromogranin A, chromogranin B, and secretogranin II and their respective peptide products were studied with in situ hybridization and radioimmunoassays after daily oral administration of haloperidol, clozapine, risperidone, or zotepine for 21 days. In behavioral tests, significant catalepsy was induced by haloperidol only. All four antipsychotic drugs increased hind paw retraction time but only haloperidol also increased forelimb retraction time. In the caudate putamen, haloperidol increased both enkephalin mRNA expression and enkephalin tissue levels. Neither of these parameters was altered by the other three drugs. In the prefrontal cortex, antipsychotic drugs generated a distinct pattern of gene expression in two regards. First, the dopamine D(2) receptor antagonist, haloperidol, did not significantly alter synaptic protein levels or their encoding mRNAs. Secondly, there was a differential change in tissue levels and mRNA expression since secretogranin II was not affected by any tested antipsychotic drug. This study shows that different types of antipsychotic drug induce distinct behavioural effects as well as differential changes in the biosynthesis of synaptic proteins and their encoding mRNAs. The data reinforce the notion that haloperidol can be classed as a typical antipsychotic drug whilst clozapine, zotepine, and risperidone reflect their atypical classification.

Animals↗
PubMed1999

Successful treatment of severe myocardial failure after postpartum haemorrhage with the use of an intra-aortic balloon pump.

We report a 29-year-old primigravid who developed cardiac failure following postpartum haemorrhage unresponsive to volume resuscitation and therapy with catecholamines and phosphodiesterase-inhibitors. Transoesophageal echocardiography (TEE) demonstrated left atrial and ventricular dilatation and global left ventricular hypokinesis. No elevation of serum MB-isoenzyme fraction was detected and other organ functions remained stable. Although emergency cardiac transplantation was considered in the presented patient, the institution of intra-aortic counterpulsation was decided on as a first treatment option. Intra-aortic balloon counter-pulsation rapidly improved cardiac function and led to weaning from pharmacological cardiac support within a few days. Mechanical circulatory assist devices can be life-saving in postpartum-haemorrhage-associated cardiac failure.

Adult↗
PubMed1996

[Cryptosporidia associated gastroenteritis: epidemiologic study of children in Tyrol and Vorarlberg].

Stool samples from 523 children aged between 3 months and 6 years were examined for Cryptosporidium parvum by means of the direct immunofluorescence technique in March 1996. The specimens were sent to the Federal Public Health Laboratory in Innsbruck from general practitioners and pediatricians and from hospitals in Tyrol and Vorarlberg. The study was performed during the cold season in an area that does not employ surface water for the production of drinking water. Oocysts of cryptosporidia were detected as the sole agent in 4 out of 294 samples (1.4%) taken from children suffering from diarrheal disease, as well as in 1 out of 229 samples (0.4%) of children in the control group. Duration of diarrheal disease varied from 2 days to 4 weeks. In addition, a 75 stool samples from Tyrolean calves were examined for cryptosporidia. Oocysts were detected in 3 out of 75 stool samples (4.0%). Routine examinations for Cryptosporidium parvum in stool specimens of immunocompetent children with diarrhea do not seem to be necessary in Western Austria during the cold season due to the self-limiting course of the infection.

Animals↗
PubMed1995

[A prospective study of early diagnosis of lunate necrosis by means of MRI].

AIM: Early recognition of lunate necrosis by means of MRI. METHODS: 49 patients with typical symptoms and normal radiographs were examined. Coronary T1 and T2 weighted images were obtained. In addition, an attempt was made to quantify fluid shift and measure of bone marrow oedema by means of extreme T2 weighting (TR 5950 ms, TE 150 ms). RESULTS: Three instances of necrosis were found; in two cases it was possible to demonstrate marrow oedema. Oedema preceding necrosis could not be demonstrated by quantifying a grey scale. CONCLUSIONS: The pattern of pain in the region of the lunate is not typical and is usually not of bone origin. Early MRT will show lunate necrosis only rarely; nevertheless, the therapeutic consequences justify the examination if pain persists for several weeks. Extreme T2 weighting for quantifying a grey scale to demonstrate early marrow oedema has not proved useful. Our experience suggests that T2 weighting is adequate and is the method of choice for the early recognition of necrosis of the lunate.

Adult↗
PubMed1995

[The magnetic resonance tomographic optimization of hip joint cartilage visualization by the selection of a T1-volume gradient-echo sequence and the use of hip-joint traction].

PURPOSE: The purpose of this study was to examine the accuracy of MR imaging of the healthy and the arthrotically altered articular hip cartilage with in vivo and in vitro separation of femoral head cartilage and acetabular cartilage. MATERIAL AND METHODS: Images of three animal cadaver hips, 8 dissected patient femoral heads and 18 hip joints of human corpses, all either with arthrosis stage I-III or artificial cartilage defects, were compared with their corresponding anatomic sections. Additional histomorphologic examinations of the arthrotic cartilages were conducted, and MR-Imaging of 20 healthy and 21 arthrotic patient hips was performed using a specific traction method. RESULTS: Using a T1-weighted 3-dimensional gradient-echo sequence and a traction of the hip joint, it was possible due to the low-signal imaging of the joint space to separate in vivo the high-signal femoral head cartilage from the high-signal acetabular cartilage. In horizontal position of the phase-encoding parameter, minimisation of the chemical-shift artifact, mainly in the ventro-lateral areas, was accomplished. MRI measurements of the articular cartilage widths showed significant correlations (p < 0.001) with the corresponding anatomic sections. At the same time the T1 3-dimensional gradient-echo sequence of the lateral femoral head with r = 0.94 showed the lowest deviations of the measurements. It was possible with MR imaging to distinguish four cartilage qualities. CONCLUSIONS: Using these MR-examinations, an improved imaging of early stage arthrotic cartilage defects is possible, and the status of the arthrotic hip cartilage with regard to intertrochanteric osteotomy can also be assessed.

Animals↗
PubMed1994

Practical suggestions for improving MRI throughput and quality.

As the use of MRI increases, radiology managers and healthcare providers will need to use a variety of methods to decrease patient anxiety and minimize on-site cancellations. This article describes some practical methods and devices which can help patients tolerate lengthy exams in confining equipment, inspire return visits from repeat patients, and gain referrals from physicians and patients.

Anxiety↗
PubMed1992

[The potentials and limits of blood-flow quantification in the peripheral arteries with MRT using a phase-mapping procedure].

MRT is able to demonstrate arteries while MR angiography can quantify blood flow by a noninvasive method. In the present paper blood flow measurements were carried out in four selected cases on the basis of phase mapping. In 3 patients with lesions in the pelvis or thigh, angiography was performed in order to localise the stenosis or occlusion and this was followed by quantitative blood flow measurements. The results showed that angiography may not always provide all necessary information concerning a haemodynamically significant stenosis. The method may also be used for quantifying blood flow in the renal arteries and that it has significant advantages over the colour Doppler method.

Aorta, Abdominal↗
PubMed1989

[The value of the transbrachial approach for arterial visualization using a 4-F catheter].

To assess the safety of nonselective intraarterial digital subtraction angiography (DSA) performed from a transbrachial approach with 4-French-catheters, the complications occurring in 158 examinations were studied. Two patients developed local thrombosis and in four patients there were temporary pulse deficits. Three brachial artery catheterisations were unsuccessful due to transient arterial spasm. Our data support the conclusion that nonselective transbrachial DSA is a safe and accurate method, easily employed in an outpatient population.

Adult↗
PubMed1989

Enterotoxigenic Escherichia coli associated diarrhea: the clinical pattern in Khmer children.

One hundred and fourty eight children with diarrhea of less than 1 week duration, admitted to hospital, were studied. Sixteen cases with enterotoxigenic Escherichia coli (ETEC) associated diarrhea and 132 cases from whom ETEC was not isolated were compared. Age, nutritional status and duration of illness were similar in both groups. Children with ETEC infections passed more loose stools (P = 0.006), were more severely dehydrated (P = 0.0007) and were more lethargic (P = 0.04) on admission than children without ETEC infections. Complications were more often observed in the ETEC group. Six children with ETEC infections had severe hypotension and required intravenous rehydration therapy (P = 0.005). Four of them developed hypovolaemic shock (P = 0.002). Multiple antibiotic resistance was observed in 75% of ETEC isolated from children with diarrhea. Seasonal variation of ETEC shows a bimodal distribution before and after the rainy season. Concomitant infections were diagnosed in 71% of children, 66% got antibiotic treatment and 93% received oral rehydration solution (ORS). Two children died during hospitalization. Case fatality rate was 1.35 per cent. The findings of this study indicate that ETEC is a common cause of diarrhea in Khmer children and can cause severe disease.

Child, Preschool↗