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Biomedical subjects

K Schmidt

Publications and source records attributed to K Schmidt.

At least 523 records · Page 29Linked to original sources
PubMed1982

The effect of stimulant medication in childhood-onset pervasive developmental disorder--a case report.

Pharmocological treatment with stimulant medication in childhood schizophrenia and pervasive developmental disorders often renders poor, but occasionally encouraging results. This report describes a case of childhood-onset pervasive developmental disorder in which long-term treatment with 40 mg methylphenidate per day brought about an initial improvement but subsequent deterioration of the child's behavior. Theoretical and practical issues concerning the use of stimulants in pervasive developmental disorder are discussed.

Attention Deficit Disorder with Hyperactivity↗
PubMed1982

[Hereditary drusen of Bruch's membrane. II: Studies of semi-thin sections and electron microscopy results].

Examination of a bulbus from a patient with hereditary drusen of Bruch's membrane revealed gradual development of drusen from fingerlike and fungous projections of the basal membrane of the retinal pigment epithelium culminating in large deposits with a conspicuous radial and laminar arrangement. The granular material which formed the drusen contained cellular debris as well as fragments of the fibrous long-spacing collagen. Cells of the pigment epithelium proliferated as metaplastic glial cells with formation of a new stratum separating the layer of cones and rods from Bruch's membrane. Transmembranous fibrovascular proliferation from the choroid into the periretinal space was not encountered and does not seem to play a decisive role in the pathogenesis of the disease.

Choroid↗
PubMed1981

[Different effect of taurolithocholate and chenodeoxycholate on structure and function of isolated hepatocytes (author's transl)].

Alterations of cellular membranes under the influence of bile acids seem to be of pathophysiological importance in cholestasis. The effect of taurolithocholic acid (TLCA) and chenodeoxycholic acid (CDCA) on membrane structure and release of cellular enzymes was studied on isolated rat hepatocytes. The response of urea synthesis to glucagon was used as a parameter of membrane function. The threshold dose of TLCA, marked by rapidly increasing enzyme release, was about 100 micrometers, whereas that of CDCA was between 500 and 1,000 micrometers. Addition of albumin (1 g-%) increased the threshold dose of CDCA; this occurred for TLCA only 8 g-%. Electron-microscopical alterations of the endoplasmic reticulum and submembranous areas were found with concentrations below these threshold doses even in the presence of albumin. These alterations are interpreted as disturbance of cellular transport and energy metabolism. TLCA inhibited glucagon response of cells in concentrations below 100 micrometers. These results demonstrate an influence of the bile acids studied on structure and function of liver cell membranes, which may be of importance in the pathogenesis of cholestasis. The rough endoplasmic reticulum could be another cellular structure which is affected by these bile acids.

Animals↗
PubMed1981

Asbestos-related diseases in the Federal Republic of Germany.

Until recently, in the Federal Republic of Germany there has been a lack of epidemiological data on asbestos-related tumors. Only the numbers of occupational diseases accepted for compensation by the German industrial injuries insurance institutes (Berufsgenossenschaften) can be stated. These show, for 1979, 94 cases of asbestosis, 21 cases of asbestosis associated with lung cancer, and 34 cases of mesothelioma. Since 1972 employees exposed to asbestos dust have been included in a central register by the industrial injuries insurance institutes and are medically examined periodically. By December 31, 1979, 28,476 persons were registered. Of those, 6,582 were still being followed medically, although they were no longer working with asbestos dust exposure. In January 1, 1977, a prospective epidemiological study was started with these people who were formerly exposed to asbestos dust. Up to December 31, 1980, altogether 2,944 people were enrolled in the study. Besides several other enrollment criteria, the individual's permission was required to evaluate his personal data. Of the people enrolled, 85 had died by December 31, 1980. Even if five questionable cases of lung cancer are excluded (n = 80), the observed rates of about 43% tumours of all sites, with 15% lung cancer and 6% mesothelioma, seem to be comparable to the international epidemiological mortality pattern.

Adult↗
PubMed1981

Localization of exogenous 14C-oxalate in rats determined by whole-body- and microautoradiography.

A single dose of 14C-oxalate was given to Wistar rats using a throat probe. The animals were sacrificed and the oxalate distribution was determined using whole-body-autoradiography. The results showed that a large portion of the absorbed oxalate had reached the bladder 30 min after administration. It is possible that this rapid renal excretion could lead to a short-term oxalate peak in the urine. The oxalate also showed a great affinity for bone. This suggests that there is a deep compartment for oxalate in bone. At the light microscopic level, the localization of 14C-oxalate in bone and in the gastric wall was demonstrated using microautoradiography. This appears to show that there is gastric excretion of absorbed oxalate. Further pharmacokinetic investigations are necessary to confirm this conclusion.

Animals↗
PubMed1981

[Stereotaxic brain operations in erethitic imbecility (author's transl)].

Long-term results of stereotaxic operations in 23 patients with severe erethitic (aggressive-destructive) imbecility were evaluated. Target areas in the thalamus, electrocoagulated in separate bilateral operations, were the dorsomedial nucleus and the internal medullary lamina. Definite tranquilization was achieved in 50% and acquiescence in 27% of patients, resulting in a positive effect on more than 75% of patients. The postoperative course showed a constant level of quiet behavior in only 25% of patients ("static course"), whereas 50% of patients showed an oscillating course leading to subsequent improvement and later stabilization ("undulant course"). The final outcome was improvement and later stabilization ("undulant course"). The final outcome was not improved in 25% of patients. Additional therapeutic measures involving adaptation of psychopharmacotherapy improvements in surroundings, and play and working therapy were occasionally effective (Fig 3). In the pneumoencephalograms of these patients a new distinctive variant was encountered that awaits confirmation: typically, a definite increase in thalamic height, a decrease in ventricular width, and a relative diminution of base line length was found. Stereotaxic thalamotomy in erethitic imbeciles is a therapeutic method with a 75% long-term effectiveness and should be considered a proven therapeutic alternative.

Adolescent↗
PubMed1981

Effect of two levels of induced hypocapnia on cerebral autoregulation in the acute phase of head injury coma.

In eight unconscious and artificially ventilated patients with severe head injury, cerebral autoregulation (CA) was tested during angiotensin infusion, before and after a reduction of Paco2. Intracranial pressure (ICP) and systemic arterial pressure (SAP) were continuously recorded. Regional cerebral blood flow (rCBF) was measured by the intracarotid Xe133 washout technique as initial slope index, stochastic and compartmental analysis. In contradistinction to previous human studies, we found a preserved CA during moderate hypocapnia (mean Paco2 34.2 mmHg) while the CA after a further decrease in Paco2 (mean value 23.1 mmHg) was lost. The apparently preserved CA may be a "false phenomenon" due to a regional increase in ICP. After a decrease in Paco2, an association between high CO2 reactivity and rCBF increase during angiotensin was disclosed, while a decreased or unchanged rCBF was observed in regions with inverse steal or abolished CO2 reactivity. The study indicates that the interpretation of CA is facilitated by performing the test during two levels of Paco2, but the presence of impaired autoregulation in the acute phase of head injury indicates that deliberate increase in SAP may be dangerous, as it may provoke an increase of regional ICP and brain oedema.

Adolescent↗
PubMed1981

[Therapy of toxin absorption in skin burns. Synthetic skin replacement or tannic acid (author's transl)].

The influence of toxic factors from burned skin on pathogenesis of burn disease has been demonstrated in recent years. For preparation for skin transplantation synthetic material is used. The present study was undertaken to investigate if such material could inhibit the resorption of toxic factors. Specific mitochondrial alterations, which are reproducibly found 5 days after skin burn or application of burn toxin, served as parameter. Rats, which were treated shortly after burn or later with tannic acid were used as controls. Glucose and urea were measured in serum to check the synthetic function. Therapy with Epigard resulted in a better general condition and normal values of glucose and urea, but no reduction of specific mitochondrial alterations. Treatment with tannic acid caused no improvement in general condition, glucose and urea levels were not significantly altered. Only the early application resulted in a reduction of mitochondrial alterations. An otherwise indicated therapy with a synthetic skin material is not suitable for inhibition of the resorption of toxic factors from burnt skin.

Animals↗
PubMed1980

Analytical isotachophoresis: a rapid and sensitive method for determination of urinary oxalate.

A variety of procedures have been described in the literature for quantitative determination of urinary oxalate concentrations. However, a rapid and sufficiently simple technique for routine determinations is lacking. This study presents an isotachophoretic technique for measurement of urinary oxalate. Complete separation of the oxalate anion from accompanying ions is achieved in a PTFE-capillary between two electrodes according to differences in the net mobility. Short analysis time, little pretreatment of the urine samples, and extremely high resolving power and accuracy are the significant advantages of this newly developed method. This new technique was shown to be of significant value in studying the role of oxalate in urinary stone disease.

Electrophoresis↗
PubMed1980

[Isolated liver cells of the rat under the influence of a toxic factor from burnt human and animal skin (author's transl)].

The existence of a burn toxin which could be responsible for the late burn disease has become increasingly accepted. The present study investigates both metabolism and ultrastructure of isolated rat hepatocytes both under the influence of a burn toxin isolated from burnt mouse and human skin and of its native nontoxic precursor. Cells from rats treated with toxin systematically were also investigated. The cells directly incubated with toxin showed no alterations of gluconeogenesis, but a reduced urea--and glycogensynthesis from most precursors used. Cells of pretreated rats were reduced in all functions and showed more distinct ultrastructural damage, while those incubated directly were significantly more altered. The results prove a direct toxic effect of a burn toxin on isolated liver cells.

Amino Acids↗
PubMed1980

Intracranial Saccular Aneurysms. Results of treatment in 851 patients.

The series studied comprises all 851 patients with symptom-producing intracranial saccular aneurysms admitted to the departments of neurosurgery in Denmark in the five-year period of 1970-1974. The series was divided into seven clinical stages according to Hunt's classification. More than half of the patients were grouped in stages IV and V (Hunt grade 2-3). Of the patients, 76% were found primarily suitable for operation. The mortality within the individual stages was to a great extent independent of the time of operation. A total of 94% of the aneurysms were localized within the region of the carotid artery, with a roughly equal distribution among the internal carotid, anterior communicating, and middle cerebral arteries. Multiple aneurysms were found in 19% of the patients subjected to panangiography. There was a distinct correlation between the severity of the spasms and the clinical condition. The course of operation was complicated in 49% of the patients, the complications being equally distributed within the various clinical stages. The mortality for the patients who underwent operation (total 567) was 32%, and 80% of the deaths were due to direct or indirect consequences of aneurysmal bleeding. At the follow-up performed two to seven years after operation, 52% of the survivors were fully capacitated, 20% were partly capacitated, and 28% were incapacitated. Based on a retrospective analysis, we have started a comprehensive prospective study with registration of available parameters in patients with saccular aneurysms admitted to all departments of neurosurgery in Denmark.

Adolescent↗