Biomedical subjects

K Wilhelm

Publications and source records attributed to K Wilhelm.

At least 91 records · Page 5Linked to original sources

PubMed1998

[TIPSS: technical and clinical results after 4 years].

PURPOSE: Retrospective analysis of the technical and clinical results after transjugular portosystemic stent shunt (TIPSS) procedure. METHOD: Between 1992 and 1996 we tried to establish a TIPSS in 90 patients. The indications were: recurrent variceal haemorrhage (n = 74), refractory ascites (n = 12), hepatorenal syndrome (HRS) (n = 4). Due to advanced liver cirrhosis 16 patients suffered of severe renal dysfunction (HRS). 57 patients had ascites. RESULTS: TIPSS implantation was technically successful in 96.7% (1992-1994: 5.1%, 1995-1996: 100%) of the patients. Complications occurred in 14.9% (1992-1994: 25.6%, 1995-1996: 6.3%). TIPSS-associated mortality was 2.3% (1992-1994: 5.1%, 1995-1996: 0%). 76.1% of the patients required reinterventions. 85.3% of reinterventions were necessary in the first year after TIPSS placement. The survival rate without reintervention was 28%, 21% and 9% for Child A, B, and C patients, respectively. Recurrent variceal haemorrhage occurred in 12.7%. De novo hepatic encephalopathy developed in 13.8%. Ascites improved in 79.2% and renal function in 75% of the patients. CONCLUSION: TIPSS is an effective method to treat recurrent variceal haemorrhage, refractory ascites and HRS. Complication and mortality rate depend on the investigator's experience and on the technique used.

Adult↗

PubMed1998

[Visualization of renal arteries and value of color-coded duplex sonography in renal artery stenoses using an ultrasound signal enhancing agent].

PURPOSE: To assess whether the use of an echo-enhancing agent reliably allows the diagnosis of renal artery stenosis with colour-coded Doppler sonography. MATERIALS AND METHODS: We examined the main, segmental, and, if present, the accessory renal arteries of 31 patients before and after intravenous injection of Levovist using colour-coded Doppler sonography and compared the results with digital subtraction angiography. A rise in peak systolic velocity in the main renal artery and a reduction of the acceleration index in segmental arteries were used as parameters to detect renal artery stenosis. RESULTS: After i.v. administration of Levovist the main stem of the renal arteries could be well delineated in 36 of 62 cases (58%) during colour-coded Doppler sonography against 31 cases without Levovist. Taking only the visible cases in account the sensitivity of native as well as of enhanced colour-coded Doppler sonography of the renal main stem was 100%, the specificity was 96% and 94%, respectively. Only one of 11 accessory renal arteries was identified after echo enhancement. The segmental arteries were seen only after echo enhancement in 12 cases so that 60 of the total of 62 renal arteries (95%) could be evaluated. The sensitivity and specificity of the native examination were 67% and 70%. After echo enhancement sensitivity was 75% and specificity was 81%. CONCLUSION: Using an echo-enhancing agent the sensitivity and specificity for detection of relevant renal artery stenosis could only be slightly improved compared to the native examination.

Aged↗

PubMed1998

Male sterility and meiotic drive associated with sex chromosome rearrangements in Drosophila. Role of X-Y pairing.

In Drosophila melanogaster, deletions of the pericentromeric X heterochromatin cause X-Y nondisjunction, reduced male fertility and distorted sperm recovery ratios (meiotic drive) in combination with a normal Y chromosome and interact with Y-autosome translocations (T(Y;A)) to cause complete male sterility. The pericentromeric heterochromatin has been shown to contain the male-specific X-Y meiotic pairing sites, which consist mostly of a 240-bp repeated sequence in the intergenic spacers (IGS) of the rDNA repeats. The experiments in this paper address the relationship between X-Y pairing failure and the meiotic drive and sterility effects of Xh deletions. X-linked insertions either of complete rDNA repeats or of rDNA fragments that contain the IGS were found to suppress X-Y nondisjunction and meiotic drive in Xh-/Y males, and to restore fertility to Xh-/T(Y;A) males for eight of nine tested Y-autosome translocations. rDNA fragments devoid of IGS repeats proved incapable of suppressing either meiotic drive or chromosomal sterility. These results indicate that the various spermatogenic disruptions associated with X heterochromatic deletions are all consequences of X-Y pairing failure. We interpret these findings in terms of a novel model in which misalignment of chromosomes triggers a checkpoint that acts by disabling the spermatids that derive from affected spermatocytes.

Animals↗

PubMed1998

Psychosocial factors associated with depression: a study of socially disadvantaged women with young children.

This study aims to use valid measures to a) estimate the prevalence of depressive disorder and b) identify psychosocial factors associated with depression in a sample of socially disadvantaged women with children. One hundred ninety-three women, recruited through a doorknock of public housing estates completed an interview that included the Diagnostic Interview Schedule to identify cases of depression and the Mannheim Interview for Social Support. The women also completed self-report questionnaires assessing psychological morbidity, life events, perceptions of intimate relationships, and personality factors. The 6-month prevalence of major depression was 17% and the lifetime prevalence 29%. Major depression was associated with perceptions of low parental care during childhood and low care from current partner, vulnerable personality style, increased reporting of life events, and an unsatisfactory social support network.

Adolescent↗

PubMed1998

On modelling personality disorders: are personality style and disordered functioning independent or interdependent constructs?

Current descriptors of personality disorder (PD) are an amalgam of two constructs, personality style and/or disorder. We seek to determine whether their intrinsic personality style descriptors are proxy measures of, or independent of, disordered personality functioning. In a sample of depressed patients, psychiatrists rated 16 differing PD personality style vignettes and assessed eight differing manifestations of disordered functioning. When "personality" vignettes and identified personality clusters were intercorrelated with "disorder" variables, interdependence was generally evident, suggesting that the personality descriptors underpinning current definition of the PDs actually act as proxy criteria for assessing disorder because they are, in and of themselves, descriptors of pathological functioning. The obsessional personality vignette provided an exception, seeming to be independent of disordered function. Such results assist consideration of how best to model, define and measure the personality disorders.

Adolescent↗

PubMed1998

Pulmonary infiltrates in neutropenic patients with acute leukemia during chemotherapy: outcome and prognostic factors.

STUDY OBJECTIVE: To determine predictors of mortality from pulmonary infiltrates in neutropenic patients with acute leukemia during chemotherapy, and the significance of those factors related to the underlying malignancy and its therapy as well as of those related to the severity of the illness associated with pulmonary infiltrates. DESIGN: A historical cohort study. SETTING: A university teaching hospital and tertiary referral center. PATIENTS AND METHODS: Overall, 53 patients with neutropenia during chemotherapy and with first episodes of pulmonary infiltrates during a 4-year period were studied. Prognostic analysis included 38 variables. Multivariate analyses were performed by logistic regression. RESULTS: The survival rate from pneumonia was 57% (30/53). The following eight parameters were significantly associated with death in univariate analysis: comorbidity present; development of "late" pulmonary infiltrates (> or = 14 days after hospital admission); heart rate > or = 100 beats/min; a ratio heart rate/systolic blood pressure (HR/SBP) > or = 1.2; urea nitrogen > 7 mmol/L; radiographic score > or = 3; neutropenia < 1.0x10(9)/L at the treatment end point; and failed complete remission. In a multivariate model including only parameters available at diagnosis of pulmonary infiltrates, the presence of a ratio HR/SBP > or = 1.2 and of a radiographic score > or = 3 remained independently associated with death. In a second model also including the evolutionary parameter neutropenia < or = 1.0x10(9)/L at the treatment end point, both parameters remained significant together with neutropenia <1.0x 10(9)/L at the treatment end point. The presence of a ratio HR/SBP > or = 1.2 was a strong marker of early death. CONCLUSION: Both therapy- and malignancy-associated neutropenia as well as the severity of illness associated with pulmonary infiltrates are independent prognostic factors. Patients with a ratio HR/SBP > or = 1.2 at diagnosis of pulmonary infiltrates suffer from potentially reversible acute illness, are at risk for early death and, therefore, may be appropriate candidates for treatment in an ICU.

Adult↗

PubMed1998

"Acting out" and "acting in" as behavioral responses to stress: a qualitative and quantitative study.

In a sample of 270 depressed patients, we describe some behaviors in response to stress. One third acknowledged "acting out" behaviors--angry, destructive acts and "out of control" behaviors. Four fifths acknowledged "acting in" behaviors--most commonly withdrawal. As a percentage of subjects acknowledged both response styles (with alternate expression influenced by situation), we developed a dimensional self-report measure within a subsample of 177 who attended a follow-up reassessment. Assignment to four groups with contrasting expressions of "acting out" and "acting in" scores demonstrated differences in age, diagnostic status, age of onset of depression, and self-injurious behaviors.

Acting Out↗

PubMed1998

An aetiological model of non-melancholic depression: study design and validity of the measures.

OBJECTIVE: The aim of this paper is to describe an approach to sub-typing non-melancholic depression and to determine which raters from a variety of backgrounds provided the most valid information on study variables. METHOD: A sample of non-melancholic depressed patients is described. Multiple raters (i.e. patients, psychiatrists, referrers and corroborative witnesses) completed measures of the patient's trait anxiety levels, severity of recent life event stressors and personality functioning. RESULTS: The study and representative data are reported. Congruence between several measures employed indicated that psychiatrist rating of disordered personality was superior to corroborative witness report. Assessment of anxiety traits indicated reasonable agreement between referrers and corroborative witnesses but poor agreement between those ratings and interview-elicited ratings. There were also discrepancies in quantifying 'severity' of life event stress, with patients and their corroborative witnesses rating such events as more severe than either the interviewing psychiatrist or psychiatrists involved in consensus rating sessions. Importantly, the psychiatrists' capacity to quantify the relative contribution of disordered personality, anxiety and life-event stress to the particular depressive episode was supported. CONCLUSIONS: Results indicate some of the difficulties in operationalising determinants that may contribute to and sub-type the non-melancholic depressions, and demonstrate the advantages of using a range of rating strategies and raters. In this study, psychiatrist-generated judgements are clearly favoured, although the advantages of also assessing trait anxiety and life-event stress impact by self-report strategies are conceded. Some techniques for estimating the contribution of disordered personality function, anxiety and life-event stress are offered for both their research and their clinical utility.

Adjustment Disorders↗

PubMed1998

Neural network subtyping of depression.

OBJECTIVE: To examine the applicability of a neural network classification strategy to examine the independent contribution of psychomotor disturbance (PMD) and endogeneity symptoms to the DSM-III-R definition of melancholia. METHOD: We studied 407 depressed patients with the clinical dataset comprising 17 endogeneity symptoms and the 18-item CORE measure of behaviourally rated PMD. A multilayer perception neural network was used to fit non-linear models of varying complexity. A linear discriminant function analysis was also used to generate a model for comparison with the non-linear models. RESULTS: Models (linear and non-linear) using PMD items only and endogeneity symptoms only had similar rates of successful classification, while non-linear models combining both PMD and symptoms scores achieved the best classifications. CONCLUSIONS: Our current non-linear model was superior to a linear analysis, a finding which may have wider application to psychiatric classification. Our non-linear analysis of depressive subtypes supports the binary view that melancholic and non-melancholic depression are separate clinical disorders rather than different forms of the same entity. This study illustrates how non-linear modelling with neural networks is a potentially fruitful approach to the study of the diagnostic taxonomy of psychiatric disorders and to clinical decision-making.

Behavioral Symptoms↗

PubMed1998

[Stress on the wrist joint in semilunar bone necrosis--a morphologic study in vivo].

The distribution of subchondral mineralization of the distal articular surface of the radius was examined by CT osteoabsorptiometry in both wrists of twelve patients showing different stages of Kienböck's disease. The pattern of density distribution had already been demonstrated in previous studies to be an adequate parameter for assessing axial loading across the wrist joint in the patients. Contrary to the anticipated presence of predominant stress in the lunate compartment, some patients showed identical stress in the compartment of the scaphoid, and the balanced loading of both compartments, as before. Even when in early stages of the disease the lunate type of mineralization appeared more often, it was still not possible to demonstrate general excessive stress on the lunate. We have therefore concluded that the main stress in the scaphoid compartment might be a secondary effect, which is to be regarded as the expression of the advancing destruction of the lunate and consequent loss of load transmission through this compartment. This hypothesis is also supported by the fact that, in progressive stages of Kienböck's disease, the density maximum in the fovea lunata, generally present in healthy people, is absent. Furthermore, in patients with necrosis of the lunate, the total mineralization in terms of the maximal density values in the distal joint surface of the radius is in the majority of cases less than in the normal subject. In two cases, even the density maximum was absent from the fovea lunata of the contralateral wrist joint, without there being any clinical signs suggesting a possible lunate necrosis on this side. We interpret these pathological changes in the unaffected wrist joint as a further indication that we are dealing with a congenital predisposition which affects both wrist joints.

Absorptiometry, Photon↗

PubMed1998

[Callus distraction for lengthening of mid-hand and finger stumps in congenital hand abnormalities--personal results and review of the literature].

Distraction-lengthening technique is quite useful in a variety of congenital hand deformities with hypoplastic, or primary normal but secondary shortened (constriction ring syndrome) finger rays. It appears that around the age of two years is the earliest practical time to start distraction; certainly distraction and secondary surgical procedures to improve function should be completed before school entry age whenever possible. Between June 1990 and March 1993, nine distraction lengthening procedures (5 thumbs, 1 index, 3 little fingers) in five patients presenting with congenital hand deformities, were carried out. Although restoring length to the finger, lengthening does not provide normal circumference or, of course, interphalangeal joint motion. Amelioration in function seems to be more important than the esthetic gain. Distraction lengthening tolerates only few errors of indication, operative technique, and/or postoperative management. A high compliance of the patient and her/his parents as well as a close follow-up by an experienced surgeon, are mandatory for a good result. A variety of possible complications have been described. Generally, complication risk increases in cases of simultaneous and multiple level lengthening. Provided adequate operative technique and postoperative care, superficial pin infection and fracture in the region of distraction are the major complications. Contrary to adults, sufficient bone formation by distraction is the rule in children. Therefore, the distraction-lengthening technique is preferred to the distraction-interposition technique in the treatment of congenital hand deformities. The latter should only be used as a salvage procedure in the rare cases of insufficient callus formation. Because of the missing growth potential and reduced joint mobility, distraction lengthening is the therapy of second choice when compared to microvascular second toe transplantation.

Acrocephalosyndactylia↗

PubMed1998

[Radiologic changes following cement-free implantation of hip prostheses. 5-year follow-up and clinical experience with the cement-free hip prosthesis Autophor-900-S].

PURPOSE: To evaluate early reliable radiographic signs of loosening in cementless total hip arthroplasty compared to clinical follow-up. METHODS: Within a time interval of 5 years 89 patients with 101 hips underwent total hip arthroplasty using the Autophor 900 S-prosthesis. Clinical and radiographic follow-up were first performed retrospectively followed by a prospective investigation. RESULTS: Radiographic evaluation showed prosthesis fixation in 93%. Loosening of the prosthesis was identified in 4 cases of the acetabular component and in 4 cases of the femoral stem. Pain was associated with radiographically detectable loosening of the cementless arthroplastic components in only two cases. CONCLUSION: Within a follow-up period of up to five years, loosening of cementless total hip arthroplasty occurs in about 7%. The most reliable radiographic signs of loosening are complete radiolucent zones wider than 2 mm at the bone-component interface, progressive subsidence, migration, or tilt of the component. Pain and movement disorders are not specific symptoms and do not necessarily indicate a loosening of the prosthesis.

Adult↗

PubMed1997

Dysfunctional parenting: over-representation in non-melancholic depression and capacity of such specificity to refine sub-typing depression measures.

We examine the proposition that dysfunctional parenting is more likely to be experienced by those with non-melancholic (compared to melancholic) depression and that, as a consequence, such specificity allows the validity of varying definitions of melancholia to be examined and their utility sharpened. We study a sample of 245 non-psychotic patients meeting DSM-III-R criteria for a major depressive episode and assign them to melancholic and non-melancholic sub-sets according to five separate sub-typing measures (DSM-III-R; DSM-IV; Newcastle; 'Clinical' and CORE criteria). We assess dysfunctional parenting by use of the Parental Bonding Instrument (PBI), and by structured psychiatrist assessment and self-report ratings of a range of dysfunctional parental experiences, with independent assessment and self-report ratings of a range of dysfunctional parental experiences, with independent assessment of the last by reports from corroborative witnesses and from the patients' referring therapists. The five sub-typing measures assigned varying percentages of the sample (24-42%) to a 'melancholic' sub-type. When Newcastle Index assignments were examined, there was no evidence that dysfunctional parenting had any specificity to non-melancholic depression. Neither the DSM-III-R nor DSM-IV systems demonstrated specificity in relation to PBI scores, but several interview-assessed dysfunctional parenting characteristics were over-represented in their non-melancholic sub-sets. 'Clinical' definition showed the greatest over-representation of dysfunctional parenting to those assigned as having non-melancholic depression. The CORE measure, a behaviourally weighted measure of psychomotor disturbance, was the next most differentiating. Importantly, those assigned as having non-melancholic depression by all five measures were more likely to be rated by corroborative witnesses as being exposed to anomalous parenting, validating the subjects' self-reports, arguing against results being an artefact of clinician-based assessment, and supporting the specificity of dysfunctional parenting to a depressive sub-type.

Adolescent↗

PubMed1997

Subcortical hyperintensities on magnetic resonance imaging in patients with severe depression--a longitudinal evaluation.

In a longitudinal evaluation of 37 patients with severe depression who had undergone brain magnetic resonance imaging (MRI) 6 months-2 years (mean 14.1 months) previously, the degree of residual dysfunction was predicted by the extent of subcortical white matter hyperintensities (WMHS, p < .01), longer time elapsed since the MRI scan (p < .05), older age (p < .05), and older age at onset of affective disorder (p < .05). Ten (27%) patients developed "probable" dementia syndromes of the vascular type, with such syndromes being predicted by WMHS (p < .01) and older age of onset of affective disorder (p < .05). Institutionalization of patients was predicted largely by the combination of chronic depression, progressive cognitive decline, and advanced age. The study supports the notion that a subgroup of patients with late-onset depressive disorders, without a family history of depression, and with risk factors to cerebrovascular disease, have extensive WMHS on MRI, and that such structural brain changes predispose to chronic depression and progressive cognitive decline.

Adult↗

PubMed1997

Early onset depression: the relevance of anxiety.

The aim of this study was to determine risk factors that may differentiate early onset from late onset depression. A non-clinical cohort that had been assessed from 1978 to 1993 at 5 yearly intervals and that had a high prevalence rate of lifetime depression took part in the study. We established an appropriate age cut-off to distinguish early onset (i.e. before 26 years) of major and of minor depression, and examined the relevance of a number of possible determinants of early onset depression assessed over the life of the study. Despite several dimensional measures of depression, self-esteem and personality being considered, they generally failed (when assessed early in the study) to discriminate subsequent early onset depression, with the exception of low masculinity scores being a weak predictor of major and/or minor depression. Early onset depression was strongly predicted, however, by a lifetime episode of a major anxiety disorder, with generalised anxiety being a somewhat stronger and more consistent predictor than panic disorder, agoraphobia and minor anxiety disorders (ie social phobia, simple phobia). The possibility that anxiety may act as a key predispositional factor to early onset depression and to a greater number of depressive episodes is important in that clinical assessment and treatment of any existing anxiety disorder may be a more efficient and useful strategy than focussing primarily on the depressive disorder.

Adult↗

PubMed1997

[Functional electromyography analysis of radial replacement operation].

The aim of this electromyographic study was to evaluate the functional result of tendon transfers for radial palsy. Eighteen patients were compared to 16 healthy volunteers. The intramuscular emg of four muscles was recorded in parallel during extension-flexion movements of the wrist and fingers. The data were stored on FM tape and evaluated off-line. Contrary to expectations, transferred flexor muscles revealed only part of their overall emg activity during extension. Therefore, an "extensor quota" (EQ) was calculated for each muscle. It reflects its emg activity during extension as part of its entire emg activity. In non-transferred flexors EQ was low (11-27%). High EQ values (69-91%) were seen in genuine extensors of healthy persons. In only 6 of 18 patients did transferred flexors show an EQ equivalent to genuine extensors (> or = 69%). Best functional results were seen in transferred flexor carpi ulnaris (median EQ 68%). The EQ of transferred pronator teres was low (median 18%) and minor to flexor carpi ulnaris in each patient (P < 0.05). It is concluded that in cases of radial palsy, pronator teres is not suitable for replacing extensor muscles. Superficial flexors of the fingers, however, work in synergy with extensors of the wrist. According to the la reflex connections involved, these muscles should be a good choice for regaining extension of the wrist.

Brachial Plexus↗

PubMed1997

[Clinical experiences with a new Wiedemann method of radial replacement operation].

Many modifications of tendon transfers have been described in the treatment of radial nerve palsy. Controversy persists over the muscles of choice to get the best results in motion of wrist and fingers. Patients with radial nerve palsy and treated by the method of Merle d'Aubigne in neurophysiological tests showed that the pronator teres did not work very well for extending the wrist. Thinking about the neurophysiologic principles it seemed that the flexor digitorum superficialis of the middle and ring fingers would make a better substitute for the wrist extension. From 1994 to 1997 four patients with radial nerve palsy had a transfer of the flexor digitorum superficialis tendons from the middle and ring fingers to the tendons of extensor carpi radialis longus and brevis additional the flexor carpi ulnaris and palmaris longus transfers. The functional recovery of two patients has been tested. The functional range of wrist motion of this two patients has been better than in patients with pronator teres transfers. It can be concluded that the new modification of tendon transfers is a good way of treatment of radial nerve palsy and should be done further.

Adult↗

PubMed1997

The scapholunate interosseous ligament in MR arthrography of the wrist: correlation with non-enhanced MRI and wrist arthroscopy.

OBJECTIVE: To compare three-compartment MR wrist arthrography with non-enhanced MRI in correlation with wrist arthroscopy, and to evaluate the potential of MR arthrography for consistently visualizing all parts of the scapholunate interosseous ligament of the wrist (SLIL) and exactly diagnosing the site and extent of SLIL defects. DESIGN AND PATIENTS: In 41 patients with wrist pain (34 patients with wrist pain for more than 6 months) plain radiographs, stress views, non-enhanced MRI and three-compartment MR arthrography were done within 2 h of each other, using three-dimensional volume acquisition (0.6-1.0 mm effective slice thickness) with a gradient-recalled echo sequence and a 1.5-T magnet. The MR arthrography findings were compared with the findings from non-enhanced MRI and correlated with the arthroscopic findings in all patients. RESULTS: The dorsal, central and palmar segments of the SLIL could be delineated exactly by MR arthrography in 95% of the patients; with non-enhanced MRI only 28% of SLIL segments were seen consistently. Demonstration of SLIL defects was possible with high diagnostic confidence in 42% of SLIL segments by non-enhanced MRI and in 94% by MR arthrography. With wrist arthroscopy as the standard of reference, sensitivity and specificity values for SLIL perforations were 52%/34% for non-enhanced MRI and 90%/87% for MR arthrography. CONCLUSIONS: MR arthrography, using three-dimensional volume acquisition with thin slices (0.6-1.0 mm), combines the advantages of three-compartment arthrography and non-enhanced MRI. It shows the precise location and magnitude of ligamentous defects of all parts of the SLIL, correlates well with wrist arthroscopy and has potential implications for diagnosis and treatment planning.

Adult↗