Biomedical subjects
Publications and source records attributed to M Albers.
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OBJECTIVES: To compare the walking ability and the quality of life of patients with severe limb ischaemia treated with an arterial reconstruction (AR) or a primary below-knee amputation (BKA). DESIGN: A cohort study of patients with the first episode of ischaemia. SETTING: University tertiary referral centre. PATIENTS: Thirty-eight (AR 22, BKA 16) patients were studied over a 12-month period with a complete follow-up. CHIEF OUTCOME MEASURES: Walking ability was assessed with a subjective scale and quality of life was measured with the Spitzer QL-INDEX. The results were assessed for patients still alive (Step 1) as well as for all patients (Step 2). RESULTS: Walking ability was better in the AR group at 3 (OR = 10.37; CI 2.12; 50.74; p = 0.004), 6 (OR = 6.47; CI 1.83, 22.79; p = 0.004), and 12 (OR = 3.82; CI 1.20, 12.15; p = (0.03) months. Quality of life was significantly better for AR patients at 3 (OR = 4.32; CI 1.55, 12.02; p = 0.005) and 6 (OR = 4.40; CI 1.68, 11.53; p = (0.003) months, but not at 12 months (OR = 2.44; CI 0.95, 6.26; p = 0.06). the 12 month foot salvage rate was 68%. CONCLUSION: Walking ability and quality of life are better for AR patients than for BKA patients, even with a moderate food salvage rate.
A fifty-two-year-old male renal transplant patient underwent aortoiliac reconstruction with a bifurcated prosthesis for treatment of hypertension and deteriorating allograft function. A modified technique was used that reduced aortic cross-clamping time to twelve minutes. This simple technique is applicable to most patients, reduces warm ischemia to a minimum, and saves time for a careful aortoiliac reconstruction.
OBJECTIVE: To determine the influence of diabetes on the use of arterial reconstruction, the rate of amputation and death, and the quality of life of patients with severe limb ischaemia. DESIGN: A prospective study of patients with the first episode of ischaemia. SETTING: University tertiary referral centre. METHODS: Thirty-seven patients with diabetes and 50 without diabetes, were studied over a 12 month period with complete follow-up. MAIN OUTCOME MEASURES: The proportion of patients undergoing an arterial reconstruction, amputation rate, death rate, and quality-of-life scores. RESULTS: Patients with diabetes underwent an arterial reconstruction less often than patients without diabetes (7/37 vs. 18/50). The odds of patients with diabetes having a higher incidence of adverse outcome was 1666:1 for minor amputation, 26:1 for major amputation, and 4.7:1 for death. There was a tendency towards a lower quality of life for patients with diabetes at 3 (OR 1.94, p = 0.036), 6 (OR 1.58, p = 0.117), and 12 (OR 1.47, p = 0.185) months. CONCLUSIONS: In patients with diabetes, (1) the opportunity of undergoing an arterial reconstruction is lower, (2) morbidity and mortality are higher, and (3) the quality of life tends to be worse.
Structural and functional brain imaging have contributed significant data to our understanding of schizophrenia, but we are still unable to understand the presumably heterogeneous neuronal dysfunctions of schizophrenic disorders. Current disease models define schizophrenia as an exclusively forebrain disorder. Nevertheless, morphological and functional data support the authors' view that cerebellar dysfunction may contribute to schizophrenic disorders. This article presents a critical review of neurological signs, including results of a clinical study performed by the authors, as well as postmortem and neuroimaging findings of cerebellar pathology in schizophrenia patients and studies on other psychiatric features associated with cerebellar lesions. In addition, anatomical, physiological, and behavioral data are reviewed that argue in favor of cerebellar involvement in nonmotor brain functions. A particular cerebellar region, the anterior vermis and corresponding fastigial nucleus, is assumed to be important in schizophrenic disorders, and the neurochemistry and vermian-fastigial-forebrain pathways are shown to correspond well with current hypotheses on neurotransmitter imbalances in schizophrenia. Therapeutic implications are outlined.
For over a decade there has been a consensus that the diagnosis of schizophrenia should rest upon the presence of positive symptoms. Recently it has been suggested to give negative symptoms, which have played a prominent role in research, more diagnostic importance again. This study investigated the usefulness of that suggestion. In a sample of 489 inpatients covering the whole range of psychiatric diagnoses, the frequencies and prevalences of positive and negative symptoms were determined. Analyses of variance were calculated to assess the diagnostic validity of the different classes of symptoms. The study demonstrates that positive symptoms are of much higher diagnostic value than negative symptoms. A change of diagnostic procedures giving more importance to negative symptoms is discouraged.
Neurological soft signs are considered to be non-localizing findings and clinical neurodysfunctional correlates of schizophrenia. Sensory signs in 21 chronic schizophrenic patients were compared with those of healthy subjects. The schizophrenic patients differed significantly from the controls in graphesthesia testing; there was no clear-cut impairment of other somatic sensory modalities. The graphesthesia learning effect was weaker in the patient group. No unequivocal correlation could be found between psychopathology or course variables and dysgraphesthesia. The authors hypothesize that an impairment in graphesthesia testing may reflect a working memory deficit in schizophrenics.
The present study compared the performance on apraxia tests and additional motor tasks between medicated chronic schizophrenic inpatients (n = 21) and healthy subjects (n = 21). Praxis testing did not reveal a clear-cut apractic syndrome in the patient group. The most striking difference between patients and healthy controls was the more frequent use of body parts as object (BPO) by schizophrenic patients (P < 0.0003). There was no significant difference in psychopathology between subgroups classified according to their BPO performance, although a tendency towards a difference in duration of illness and the actual hospitalization period existed between BPO subgroups. Schizophrenic patients performed more poorly than controls in frontal motor tasks: sequencing, including oral sequential movements, and reciprocal innervation. Frontal motor task performance tended to be related to the negative dimension of schizophrenia in accordance with previous studies. The data do not support the assumption that BPO performance is part of a multidimensional concrete attitude in schizophrenic patients. Nevertheless, this peculiarity in motor behaviour might be a link between neurophysiology and psychopathological phenomenology in schizophrenia. We therefore suggest further investigation focusing the performance of object-related pantomime movements in schizophrenic patients.
Due to the anticipated revisions concerning diagnostic criteria for schizophrenia in DSM-IV, recent Anglo-American research has been particularly concerned with the controversial problem whether positive or negative symptoms are more suited for the determination of these criteria. We addressed this problem in an empirical study. A total of 489 consecutive admissions to the Department of Psychiatry at the RWTH University, Aachen were assessed for the distribution of positive, negative and basic symptoms according to six ICD-10 double-digit diagnostic categories. Positive symptoms were shown to be more useful for diagnosis than the negative or basic symptoms. Basic symptoms, however, had a pattern of distribution which supports the notion that they may also be useful for the early diagnosis of schizophrenia.
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UNLABELLED: The activity of phospholipase A2 (PLA2), an enzyme that, besides a number of other functions, is involved in prostaglandin synthesis, regulation of membrane stability, and presynaptic neurotransmitter release, has been reported to be greater in the serum and plasma of schizophrenic patients than in that of other psychiatric patients and normal controls. Furthermore, it is said to be significantly reduced by haloperidol treatment. We decided to replicate these findings in an independent sample of patients by using a highly sensitive assay for determining PLA2 activity.-- METHODS: Of 167 consecutive male admissions giving informed consent 35 were found never to have received neuroleptics previously. Ten had DSM-III diagnoses of schizophrenia, schizophreniform disorder, or atypical psychosis, eight of other psychiatric disorders and 17 of alcohol or drug dependence (Table 1). Blood samples were drawn before medication was initiated. For patients still in hospital (Table 3), this was repeated after 21 days of treatment (n = 10). Samples from 10 healthy subjects were also obtained. PLA2 activity was determined according to Märki and Franson (1986), using a radiochemical assay.-- RESULTS: On day 0, there were no statistically significant intergroup differences in PLA2 serum activity. After 21 days, it was not possible to detect any significant decrease in PLA2 activity (Table 4). The PLA2 activity of the patient groups did not differ from that of the group of healthy subjects (Table 5).-- CONCLUSION: It was not possible to replicate the finding of increased PLA2 activity in schizophrenic patients in our sample of patients never treated with neuroleptics before.(ABSTRACT TRUNCATED AT 250 WORDS)
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The purpose of this cohort study was to assess the quality of life of patients with severe ischemia as a result of infrainguinal arterial occlusive disease. Spitzer's QL-INDEX was selected to measure quality of life at baseline and at 3, 6, and 12 months. On the basis of initial treatment, 61 patients were grouped as follows: IC (conservative, n = 31), IR (arterial reconstruction, n = 14), and IA (major amputation, n = 16). After 12 months of follow-up, 48 patients were similarly regrouped according to ultimate treatment as follows: UC (n = 19), UR (n = 9), and UA (n = 20). At 12 months the mean score was significantly higher than the baseline in IC (6.43 vs 3.84, p less than 0.0001) as well as IR (5.64 vs 3.57, p less than 0.01), but not in IA (4.43 vs 3.62). The QL-INDEX mean score was lower in UA than in UC (4.15 vs 6.58, p less than 0.01) or UR (4.15 vs 7.11, p less than 0.0001). The correlation between QL-INDEX and an arbitrary scale was also high (r = 0.726, p less than 0.001). In conclusion, quality of life of patients with limb ischemia can be confidently assessed, improves during the first year of follow-up if major amputation is avoided, and improves and is sustained by a functioning graft.
Starting from the observation that using a conventional potential clamp device for membrane current measurements in Ranvier nodes neither the kinetics of sodium currents nor the constant field concept agree satisfactorily with the Hodgkin-Huxley-Frankenhaeuser (HHF)-formalism, an extendend measuring system has been developed. The extensions introduced base largely on physical implications of myelinated nerve fibres which give rise 1. to systematic distortions of any current records at the high frequency end and 2. to current proportional deviations of the membrane potential from desired potential values. In addition, we provided to meet any unwanted current load during membrane current measurements and to push the time resolution of the measuring system to the highest possible value. After having tested thoroughly the new circuitry by appropriate physical methods, from sodium current measurements the following conclusions were drawn: 1. Occasional deviations of sodium current kinetics near the sodium equilibrium potential from the predictions of the HHF-formalism are measurement errors. 2. The constant field formalism holds for sodium currents in the potential range of biological relevance only. 3. Instantaneous sodium current measurements, however, are of unsatisfactory significance because for this kind of experiments the time resolution of the measuring system used might be still too low.
Based on a sample of 42 chronic schizophrenic patients and 42 carefully matched controls, we investigated potential relationships between acoustic variables on the one hand, and negative syndromes, positive syndromes and affective disturbances, on the other. A set of 12 acoustic variables automatically assessed in a standardized experimental setting allowed an almost perfect discrimination between schizophrenic patients and normal subjects. Acute side-effects of medication did not explain this finding. However, the question of whether the observed changes in speaking behavior and voice sound characteristics were caused by long-term neuroleptic treatment, for example, as a consequence of tardive dyskinesia, could not be answered by our investigation. In view of a biological validation of the negative-positive model of schizophrenia, the reliability of various psychopathological subscales was tested through repeated assessments at 14 day intervals. We found most psychopathology scores to be sufficiently stable and reproducible over time, thus representing a suitable basis for the estimation of severity with respect to the negative and positive component of schizophrenia. Using the first measurements as training samples and the second measurements of 14 days later as test samples, discriminant analysis yielded conclusive proof of a close relationship between acoustic variables and the severity of the negative and positive component of schizophrenia. In particular, by means of "objective" acoustic variables and under the constraint of reproducibility, 75.9% of patients were correctly classified as low or high scorers with respect to the negative syndrome, 71.9% of patients with respect to the positive syndrome, and 79.4% of patients with respect to their depressive symptomatology.
Doctors as researchers often resort to hypothesis testing and confidence intervals in the statistical analysis of study results. On the one hand, the use of statistical software has made this task easier. On the other hand, this has not contributed to neither a better understanding of statistical concepts nor to a seminal cooperation between doctors and statisticians. This note shows that the classical statistical theory, also called frequentist or Fisherian, offers probability statements that are very indirect ones. Bayesian statistics, on the other hand, gives a probability statement which is a more direct answer to the research question. Of course, this latter approach would hardly be considered without a close cooperation with an statistician. An improvement in the meaning of the probability statements may be seen as a gain in quality. An effective cooperation with statisticians, an issue that is more ethical than methodological, is directed to achieving a research of a better quality, so avoiding the scandal of poor medical research.