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Biomedical subjects

R Schmidt

Publications and source records attributed to R Schmidt.

At least 415 records · Page 23Linked to original sources
PubMed1993

[Correlation of serum prolactin and cortisol values with paroxysmal disorders of epileptic and non-epileptic origin and their clinical value].

In 95 patients (44 women and 51 men, aged 14 to 86 yrs., average 44.9 yrs.) the serum levels of prolactin, cortisol and uric acid were investigated 30, 60 and 120 min after seizure-like events. There were 53 fits of epileptic aetiology (EE), mainly tonic-clonic, and 42 attacks of non-epileptic aetiology (NEE). The uric acid of the epileptic patients 30 min postictally revealed significantly higher ratings (p < 0.05) compared to the control group (n = 36), but not compared to the NEE group. Serum cortisol was significantly higher after all investigated disturbances without differences in the EE and NEE group. After epileptic and non-epileptic attacks prolactin was significantly (p < 0.05) elevated in comparison to the baseline. The increase of 3 times the amount of the individual baseline and at the same time exceeding the range of reference were found in 73% of the epileptic and only in 7% of the non-epileptic patients. As hypothesis to the postictal prolactin rise we discuss disturbances in the neurotransmitter equilibrium within the hypothalamic-hypophyseal axis. We regard prolactin as a biochemical marker, which is a valuable aid in the differential diagnosis of epileptic and non-epileptic fits.

Adolescent↗
PubMed1993

Ultrasound measurement of quadriceps muscle in the first year of life. Normal values and application to spinal muscular atrophy.

Using real-time ultrasound imaging normal values were obtained for quadriceps muscle thickness and subcutaneous tissue depth in the first year of life from 120 normal infants. These values were corrected for weight and height by introduction of a "correcting factor". In addition, a "modified muscle index" was calculated by multiplying the ratio of muscle to subcutaneous tissue thickness with the correcting factor and showed a steady increase from birth (mean 2.1) to the end of the first year (mean 4.8). The study of 12 patients with spinal muscular atrophy type I (SMA I) revealed that 9 out of 12 SMA I patients failed to reach the 3rd percentile for the muscle to subcutaneous tissue ratio and 10 out of 12 were well below the 3rd percentile for the modified muscle index due to their muscle atrophy. Only the two youngest SMA I patients aged 4 and 6 weeks reached values on the 3rd percentile. In contrast, 10 patients with myopathy and one patient with holoprosencephaly showed values within the normal percentiles even in the presence of severe clinical muscle weakness and signs of atrophy on muscle histology. In the differential diagnosis of early onset myopathy, atrophy of the quadriceps muscle during the first months of life in the absence of markedly increased echodensity seems to be a pathognomonic finding for SMA.

Body Weight↗
PubMed1993

Influence of the pretransplant hematocrit level on early graft function in primary cadaveric renal transplantation.

Although use of human recombinant erythropoietin has alleviated symptoms of anemia in renal failure, effects of increased hematocrit (HCT) on early post-transplant renal function are unknown. Of 244 consecutive primary cadaveric kidney recipients transplanted over 74 months, 43% had HCT > or = 30% and 57% had HCT < 30% at transplantation. The incidence of delayed graft function (DGF) was greater in recipients with HCT > or = 30% (61%) than in recipients with HCT < 30% (33%; P = 0.0001). Ten percent of recipients with HCT > or = 30% experienced primary nonfunction (PNF) of the allograft (P = 0.0001). No recipient with HCT < 30% had PNF. Absolute rises in HCT over the 3 months preceding transplantation were greatest in those with PNF (2.5 +/- 2.4) followed by those with DGF (2.0 +/- 3.1) and immediate graft function (IGF) (0.2 +/- 5.2; P = 0.0328). Logistic regression analysis identified HCT > or = 30% (P = 0.0014), cold storage > or = 24 hr (P = 0.0006) and rising HCT (P = 0.0090) as independent predictors of DGF with relative risks of 3.1-, 3.3-, and 2.7-fold, respectively. Recipients with rising pretransplant HCTs who underwent dialytic fluid removal within 24 hr before transplantation had DGF with greater frequency (67%) than nondialyzed recipients with rising HCTs (45%). Primary cadaveric kidney recipients with HCT > or = 30% at transplantation have significantly greater risk for DGF and PNF. Rising pretransplant HCT levels may predispose recipients to DGF; this risk may be heightened in those undergoing hemodialysis shortly before transplantation.

Adult↗
PubMed1993

Wolfram's (DIDMOAD) syndrome and its urological manifestation.

We report 2 patients with DIDMOAD syndrome (diabetes insipidus, diabetes mellitus, optic atrophy and neural deafness), with emphasis on the urological aspects and their management. Both patients underwent thorough radiological endoscopic and urodynamic evaluation, in addition to detailed evaluation of other systems involved. Each had the characteristic hyper-reflexive neurogenic bladder with sphincteric dyssynergia, which resulted in severe urinary tract dilation. One patient was diagnosed at this institution and managed conservatively with clean intermittent catheterisation and anticholinergic medication; the second patient was referred to us after several attempts at surgical correction. The presentation, details of the urological evaluation with special emphasis on the urodynamic findings, and the outcome of different means of management are discussed.

Adult↗
PubMed1993

Dialysis against a recycled albumin solution enables the removal of albumin-bound toxins.

The removal of protein-bound substances of pathogenetic relevance from blood is of therapeutic interest for drug intoxications, renal and liver failure, and metabolic disorders. Current methods using adsorbents are effective but often not specific enough. This work presents an alternative method that enables the dialyzability of albumin-bound toxins from plasma by the use of a high-flux dialyzer (F 60 Fresenius) and an albumin solution circulating on the dialysate side to increase selectively the affinity for albumin-bound toxins. This method resulted in effective removal of unconjugated bilirubin, drugs with a high protein-binding ratio (sulfobromophthalein, theophylline), and a protein-bound toxin (phenol). The additional removal of PBS could extend the applicability of dialysis, for example, to drug intoxications and liver failure or could improve the elimination of protein-bound uremic toxins in chronic renal failure.

Adsorption↗
PubMed1993

Bilateral medial medullary infarction: magnetic resonance imaging and correlative histopathologic findings.

Bilateral medial medullary infarction is a rare event which clinically presents with flaccid tetraplegia sparing the face, bilateral disturbance of deep sensation, hypoglossal nerve palsy and respiratory failure. We here report a patient with such symptoms in whom magnetic resonance imaging enabled the detection of signal abnormalities in the lower brainstem as soon as 9 h after onset. Results of a control study 3 weeks later correlated well with the extent of infarction that was seen at autopsy. Early lesion detection in the lower medulla by magnetic resonance imaging and the unfavorable prognosis of patients with ischemic damage at that location may provide the rationale for aggressive therapeutic strategies in such a condition.

Cerebral Infarction↗
PubMed1993

Brain stem infarction and diaschisis. A SPECT cerebral perfusion study.

BACKGROUND AND PURPOSE: We studied six patients suffering from pure, unilateral brain stem infarction to explore the association of remote cerebral and cerebellar blood flow changes with damage at different sites of this region of the brain. METHODS: We used single-photon emission computed tomography and [123I]iodoamphetamine to measure regional differences in tracer uptake. Qualitative image analysis and calculated asymmetry indexes were correlated to the location of the infarcted area on magnetic resonance imaging and to the patients' clinical findings. RESULTS: Significant perfusion asymmetries were noted in the two patients with infarction in the upper pons but not in those with lesions below this level. They comprised a contralateral cerebellar and ipsilateral supratentorial hypoactivity that was most marked in the frontoparietal cortex. There was no clear relation between the patterns of cerebral or cerebellar tracer uptake and specific neurological findings. CONCLUSIONS: Remote perfusion changes after pure brain stem infarction may be seen both infratentorially and supratentorially and depend on the lesion site rather than on the neurological deficit. In this context, our study confirmed damage to the corticopontocerebellar pathways as the key event in the genesis of a crossed cerebellar diaschisis. The exact mechanisms causing ipsilateral cerebral hemispheric diaschisis await further clarification.

Aged↗
PubMed1993

Neuropsychologic correlates of MRI white matter hyperintensities: a study of 150 normal volunteers.

To determine the effects of MRI white matter hyperintensities (WMH) on cognitive functioning, we used neuropsychologic tests and MRI to study 150 elderly volunteers free of neuropsychiatric or general disease. There were 76 (50.3%) individuals without and 74 (49.7%) with WMH. The latter subset was older (61.3 +/- 6.6 years versus 58.5 +/- 5.8 years, p = 0.005), had a higher mean arterial blood pressure (103.7 +/- 11.4 mm Hg versus 99.9 +/- 10.3 mm Hg, p = 0.03), and a larger ventricular-to-intracranial-cavity ratio (6.3 +/- 5.6% versus 4.7 +/- 1.6%, p = 0.02). Individuals with WMH performed worse than their counterparts without such abnormalities on all tests administered. After adjusting for the group differences in age, arterial blood pressure, and ventricular size, we noted statistically significant results on form B of the Trail Making Test (121.8 +/- 37.8 msec versus 100.3 +/- 47.9 msec, p = 0.04), a complex reaction time task (680.8 +/- 104.9 msec versus 607.1 +/- 93.9 msec, p = 0.001), and the assembly procedure of the Purdue Peg-board Test (27.5 +/- 5.8 versus 30.6 +/- 5.9, p = 0.02). Partial correlations did not reveal any relationship between test scores and the semiautomatically assessed total area of WMH. Our data suggest that the presence of WMH exerts a subtle effect on neuropsychologic performance of normal elderly individuals, which becomes particularly evident on tasks measuring the speed of more complex mental processing.

Adult↗
PubMed1993

Brain magnetic resonance imaging in coronary artery bypass grafts: a pre- and postoperative assessment.

We undertook a study to determine (1) the frequency and prognostic significance of preexisting MRI brain abnormalities in patients undergoing coronary artery bypass grafts (CABG) and (2) whether MRI can detect surgery-related brain damage in 31 neurologically asymptomatic CABG patients (mean age, 61.0 +/- 6.6 years). MRIs were performed within 7 days before and 8 to 17 days after surgery. When we compared the preoperative images with those of 31 age- and risk factor-matched neurologically asymptomatic controls free of cardiac disease (mean age, 60.3 +/- 6.1 years), higher rates of thromboembolic infarcts (16% versus 0%), lacunes (58.1% versus 32.3%), and brainstem lesions (22.6% versus 3.8%) were noted. Subjective rating demonstrated significantly larger ventricles in patients than in controls (p = 0.002). CABG candidates also had significantly increased ventricular-to-intracranial cavity ratios (VICR) as determined by semiquantitative volumetric measurements (6.9 +/- 2.5% versus 4.9 +/- 1.6%; p = 0.0004). Eleven patients had postsurgical complications, with eight having symptoms consistent with diffuse encephalopathy. The only MRI finding that separated encephalopathic from complication-free patients was ventricular size (VICR 9.0 +/- 2.5% versus 4.9 +/- 1.6%; p = 0.006). This difference remained statistically significant after adjustment for the effects of age (p = 0.04). Postoperative MRI consistently failed to demonstrate surgery-related brain damage responsible for the encephalopathy.

Aged↗
PubMed1993

Assessment of MRI criteria for a diagnosis of MS.

To test the reliability of four previously proposed MRI criteria for the diagnosis of MS, we reviewed 1,500 consecutive brain scans for the presence, number, size, and location of areas of increased signal (AIS) on proton-density and T2-weighted images, unaware of the patients' clinical presentations and ages. This series included 134 subjects with a clinical diagnosis of MS. Relying exclusively on the presence of at least three or four AIS for a positive diagnosis of MS resulted in high sensitivity (90% for three AIS and 87% for four) but inadequate specificity (71% for three AIS and 74% for four) and positive predictive value (23% for three AIS and 25% for four). If one of these lesions was required to border the lateral ventricles, specificity was 92% and positive predictive value was 50% at a sensitivity of 87%. Using the Fazekas criteria (at least three AIS and two of the following features: abutting body of lateral ventricles, infratentorial lesion location, and size > 5 mm) led to a further highly significant improvement of specificity (96%; p = 0.0000) and increase of the positive predictive value (65%) at the expense of a less significant decrease in sensitivity (81%; p < 0.01).

Adolescent↗
PubMed1993

Pathologic correlates of incidental MRI white matter signal hyperintensities.

We related the histopathologic changes associated with incidental white matter signal hyperintensities on MRIs from 11 elderly patients (age range, 52 to 82 years) to a descriptive classification for such abnormalities. Punctate, early confluent, and confluent white matter hyperintensities corresponded to increasing severity of ischemic tissue damage, ranging from mild perivascular alterations to large areas with variable loss of fibers, multiple small cavitations, and marked arteriolosclerosis. Microcystic infarcts and patchy rarefaction of myelin were also characteristic for irregular periventricular high signal intensity. Hyperintense periventricular caps and a smooth halo, however, were of nonischemic origin and constituted areas of demyelination associated with subependymal gliosis and discontinuity of the ependymal lining. Based on these findings, our classification appears to reflect both the different etiologies and severities of incidental MRI signal abnormalities, if it is modified to treat irregular periventricular and confluent deep white matter hyperintensities together.

Aged↗
PubMed1993

Expression of stratum corneum chymotryptic enzyme in reconstructed human epidermis and its suppression by retinoic acid.

The aim of the present study was to investigate the presence of stratum corneum chymotryptic enzyme (SCCE) in human epidermis reconstructed in vitro on dead de-epidermized dermis and the effect of retinoic acid (RA) on its expression. SCCE is a recently discovered serine proteinase which has been purified from human stratum corneum, and evidence has been presented that it may play a role in stratum corneum turnover, especially in desquamation. The SCCE-specific monoclonal antibody TE-9B showed positive immunofluorescence staining of high suprabasal keratinocytes, mainly in the stratum granulosum, in normal non-palmo-plantar human epidermis as well as in reconstructed epidermis in the absence of RA. This staining was also seen in reconstructed epidermis cultured in the presence of 10(-8) M RA, a concentration at which the reconstructed epidermis still formed an orthokeratotic stratum corneum. At 10(-7) M RA, however, not only the formation of the stratum corneum but also SCCE expression was suppressed. These results support the hypothesis that SCCE expression is related to and may be part of the epidermis-specific differentiation program, where the enzyme may be involved in the homeostasis of the stratum corneum, possibly by degrading the intercorneocyte cohesive structures.

Cells, Cultured↗
PubMed1993

A German drug-monitoring study in general practice patients receiving cisapride for functional dyspepsia.

An open prospective drug monitoring study was undertaken to assess the efficacy and tolerability of 5 mg cisapride three times daily in 37,925 general practice patients with functional dyspepsia. Short-term (mean, 4 weeks) cisapride treatment was associated with a significant reduction in overall dyspeptic symptom scores and improvements in scores of all eight individual dyspeptic symptoms (epigastric discomfort, fullness, nausea, bloating, heartburn, acid regurgitation, loss of appetite, and vomiting). Physician's and patient's subjective global evaluations of antidyspeptic efficacy were good or very good in 80% to 90% of cases. The tolerability of cisapride was judged to be satisfactory, good or very good in approximately 95% of patients, with adverse drug reactions being documented in 4.8% of patients. Of these, diarrhea/loose stools (2.5% of all patients) and headache (0.7%) were most frequent. Premature treatment withdrawal due to poor tolerability was necessary in only 0.35% of patients.

Adolescent↗
PubMed1993

Prolonged biochemical and morphological stability of encapsulated liver cells--a new method.

In this work a new type of polyelectrolyte complex capsules is introduced as an artificial housing for liver cells. Male Wistar rat hepatocytes were encapsulated using cellulose sulphate and polydimethyldialyllammonium chloride as polyelectrolytes. Amino acid metabolism rate and urea synthesis of the cells increased over the investigation period in contrast to the decrease observed in control monolayer cultures. The encapsulated cells were morphologically characterized. The described procedure represents a sufficient method for the cultivation of living cells in mechanically stable semipermeable microcapsules.

Amino Acids↗
PubMed1993

Primary health care of diabetic patients in a specialized outpatient setting: a DIABCARE-based analysis.

To assure health care quality requires a tool for establishing the feedback between parameters of patient management and related standards. To assess the current situation and to evaluate the DIABCARE system as a potential monitoring instrument, a retrospective study was performed in 85 randomly assigned insulin-treated patients (72% type 2) who were regularly attending the diabetes outpatient unit (total of 3,595 patients) in a township of approximately 90,000 inhabitants. 1,195 records of sequential medical visits during the years 1987 and 1990 were analyzed. -Selected results (averages in 1987 vs. 1990): (1) Visits per year 6.9 vs 7.1; (2) intensified insulin treatment in 14 vs. 27% of all patients, they were on 4.0 vs. 4.5 injections per day applying doses of 0.8 vs. 0.6 IU kg-1 d-1; (3) glycaemic control: random blood glucose 6.0 vs. 5.8 mmol/l on conventional and 6.4 vs. 5.7 mmol/l on intensified regimes, HbA1 regular measurements in 2 vs. 21% of the patients; (4) body mass index 26.4 vs. 26.6 (conventional) and 24.7 vs. 25.9 (intensified) kg/(m)2; (5) retinopathy prevalence 30 vs. 29%, in 4 vs. 29% of the patients no information; (6) nephropathy prevalence 7 vs. 11%, in 75 vs. 68% of the patients no information; (7) foot complications prevalence 6 vs. 9%, in 91 vs. 84% of the patients no pathological findings. -The DIABCARE monitor proved appropriate but too laborious. The general level of care showed a tendency towards improvement between the two investigated periods but dit not yet meet the standards which must be attained to attain the St. Vincent Declaration.

Adult↗
PubMed1993

Cerebrovascular risk factors in an elderly Austrian population: first year results of the Austrian Stroke Prevention Study (ASPS).

During the first year the Austrian Stroke Prevention Study enrolled 599 volunteers without clinical signs or symptoms of cerebrovascular disease aged 50 to 70 years. Study participants were randomly selected from the official register of the city of Graz. The rate of positive response was 26.9 percent. All subjects underwent an extensive risk factor screening with Duplex scanning of the carotid arteries obtained from a subset of 176 individuals. The prevalence of well-documented cerebrovascular risk factors was 40.6% for arterial hypertension, 35.4% for cardiac disease, 8.5% for diabetes mellitus und 3% for elevated haematocrit. The less well-documented cerebrovascular risk factors dyslipidemia, overweight, physical inactivity, hyperfibrinogenemia and smoking were noted in 75%, 33.7%, 27.2%, 14.9% and 12.2% of subjects, respectively. Multiple well-documented risk factors were noted in 23.7% of the examined volunteers. Multiple linear regression analysis revealed body mass index (p < 0.0001) and age (p < 0.0001) as independent predictors of the frequency of well-documented risk factors observed in any individual. Atherosclerotic carotid disease occurred in 61.9% of study participants investigated by Doppler sonography and was significantly associated with age (p < 0.00001), life-time tobacco consumption (p < 0.0001) and the concentration of apolipoprotein B (p < 0.05). This study demonstrates high prevalence rates of vascular risk factors in an elderly Austrian community. Implications for stroke prevention result from the conjunction of overweight and frequency of risk factors noted in any study participant, as well as from the relationship of carotid atherosclerosis to smoking and dyslipidemia.

Aged↗
PubMed1993

Surfactant inhibition by plasma proteins: differential sensitivity of various surfactant preparations.

Leakage of plasma proteins into the alveolar space may inhibit surfactant function. We compared the surface properties and the sensitivity to inhibitory proteins of different organic solvent surfactant extracts and a synthetic surfactant. Experiments were performed in the pulsating bubble surfactometer, with surfactant concentrations ranging between 0.1 and 2 mg.ml-1. Inhibition profiles towards fibrinogen, albumin and haemoglobin were obtained from calf lung surfactant extracts (CLSE), Alveofact, Curosurf and Survanta (all used in clinical, replacement studies in respiratory distress syndrome (RDS) and of an apoprotein-based synthetic phospholipid mixture (PLM-C/B; DPPC:PG:PA = 68.5:22.5:9, supplemented with 2% wt/wt non-palmitoylated human recombinant SP-C and 1% t/wt natural bovine SP-B). In the absence of inhibitory proteins, all surfactants exhibited dose-dependent rapid adsorption (rank order of relative efficacy PLM-C/B = CLSE > Alveofact > Curosurf > Survanta). Minimal surface tension was reduced to near zero values under dynamic compression (rank order PLM-C/B > CLSE > Alveofact = Curosurf) and to approximately 4 mN.m-1 (Survanta). Curosurf and Survanta were dose-dependently inhibited by fibrinogen > haemoglobin > albumin, with far-reaching loss of surface activity at protein-surfactant ratios above 1:1. In contrast, CLSE and Alveofact were only moderately inhibited by fibrinogen, and were not affected by haemoglobin and albumin, up to protein-surfactant ratios of 2:1. PLM-C/B exhibited resistance to fibrinogen, intermediate sensitivity to albumin, and was severely inhibited by haemoglobin. We conclude that various natural surfactant extracts and an apoprotein-based synthetic surfactant mixture markedly differ in their sensitivity to inhibitory plasma proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗