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Biomedical subjects

U Schulz

Publications and source records attributed to U Schulz.

At least 91 records · Page 5Linked to original sources
PubMed1982

Flow-cytometric analysis of glucose induced changes of the transmembrane potential and optical density in pancreatic islet cell suspensions.

Glucose-induced insulin release of beta cells of pancreatic islets is associated with islet cell membrane electrical activity. We measured the membrane potentials of neonatal rat islet cell suspensions by means of "optical probes" by flow cytometry. Moreover, we determined the narrow angle light scattering and light absorption in direction of the laser beam, respectively. In both these cases two or three clusters of the whole cell population showing different responses to glucose could be distinguished. Glucose-dependent depolarization as well as loss in optical density of cells of pancreatic islets should be associated with the physiological function of insulin producing beta-cells. It is concluded that changes of the membrane potential and/or optical density of islet cells produced by insulin secretagogues can be analysed by flow cytometry which might provide the basis for sorter experiments to separate specific subpopulations of cells of pancreatic islets.

Absorption↗
PubMed1982

[Combined surgical and radiologic treatment of anal cancer].

The different ways of metastases of carcinoma of the anus can hardly be removed by radical surgery and require other procedures than the lower carcinoma of the rectum. In comparing Miles operation in T3/T4 carcinomas of the anus with the combined therapy of local excision and radiotherapy results showed no great difference in T1/T2 tumors the Miles operation is not necessary. In T3/T4 carcinomas irradiation derives its worth from the few possible procedures ro radical surgery. In T1/T2 tumors irradiation can be an alternative (T1) or an additional treatment (T2) to the local excision.

Adenocarcinoma↗
PubMed1982

Histamine-receptor bearing lymphocytes. II. The use of flow cytofluorometric analysis of histamine-receptors on mouse lymphocytes of different organs.

The histamine binding capacity of cells in various lymphoid organs has been determined by flow cytofluorometric (FCF) analysis of histamine receptors. Using fluoresceinated bovine serum albumin conjugated to histamine (HIS-BSA-FITC) as a staining reagent two distinct lymphocyte subpopulations of differing fluorescence intensity have been identified in each organ investigated. The thymus has a low number of histamine-receptor bearing cells, while bone marrow, lymph nodes and spleen reveal increasing binding capacities to the histamine conjugate. It is suggested that there exists a different susceptibility of distinct lymphocyte subpopulations for histamine, thereby enabling its controlled immunoregulatory activity.

Animals↗
PubMed1982

[Clinical significance of time dose distribution in radiotherapy].

A survey is given of the mathematical and empirical methods allowing to compare different chronological dose distributions; their possibilities and limits are described. The experimental bases of hyper- and superfractionation and the clinical experiences gained hitherto with multiple daily irradiations are communicated; radiotherapy with high individual fractions and long term irradiation are shortly explained. Finally some hints are given for the further development and the practical use of not typical fractionation schemes.

Humans↗
PubMed1981

[Possibilities and limitations of radiotherapy in neoplasms of the anterior cranial fossa].

Primary and secondary tumors of the anterior cranial fossa are discussed in clinic-therapeutical survey and mainly the role of radiation therapy of some of these tumors is stressed. The possibilities of additional use of radiosensitizing substances and possible combinations with chemotherapeutic agents are related. Statistical results of our own concerning malignant glioma and retinoblastoma are shown; the last mentioned tumors are a grateful and demanding indication area of radiation therapy. Casuistic experiences with malignant melanoma of the orbital region are discussed; detailed recommendations as to radiotherapeutic management of intraorbital tumors are given.

Brain Neoplasms↗
PubMed1981

[Radiotherapy in case of intracerebral formation of metastases of non-seminomatous testicle tumors (author's transl)].

The subject of this study were non-seminomatous testicle tumors with cerebral formation of metastases. Despite the relatively low radiosensitivity of the primary tumors and their regional metastases eighteen of twenty patients were free of symptoms, and a complete regression of the intracerebral tumors was shown by computed tomography and/or scintigraphy in ten of twenty cases. This regression was obtained within two or three weeks by an irradiation of the skull with a focal dose of 30 to 40 Gy. Due to the small number of patients (20), it was not possible to demonstrate a statistically different receptiveness of the cerebral metastases according to their histological subentity. Because of the subjective stress, the duration of radiotherapy should be as short as possible (e.g. 30 Gy in 10 fractions over a period of two weeks). In our opinion, irradiation is clearly indicated in case of testicle teratomas with cerebral formation of metastases. Practically the only contra-indications are a strong intracranial hypertension as well as hyperkinesia. The entire prognosis of the patient, however, is not determined by the cerebral formation of metastases but by the pulmonary metastatic extension, so that radiotherapy is an important palliative factor with regard to the survival time of these patients.

Adolescent↗
PubMed1981

[On the problem of radiotherapeutic measures in addition to chemotherapeutic treatment of the microcellular bronchial carcinoma: analysis of recurrence rates (author's transl)].

83 patients with small-cell bronchial carcinomas were treated with a combination of cytostatic chemotherapy ("ACO II" = adriamycine, cyclophosphamide, vincristine) and irradiation of the mediastinum, the tumor umbra and the affected hilum with a focal dose of 30 Gy administered within a period of three to four weeks. During the same period, those patients presenting the favorable initial stage "limited disease" (LD) were additionally submitted to a prophylactic total brain irradiation with a dose of 30 Gy. 42 among 55 patients of stage LD had a complete remission. Among these 42 patients, fourteen had an intrathoracic recurrence, nine of them within the irradiation field. A cerebral recurrence after prophylactic brain irradiation was found in five of 42 cases. The conclusion is drawn that the irradiation dose which has to be administered into little intrathoracic fields must be increased. A dose of 45 Gy within 4 1/2 weeks is desirable. It seems that a prophylactic brain irradiation is only efficient in patients with a favorable prognosis (LD, CR).

Brain Neoplasms↗
PubMed1980

[Late results of reconstructive surgery for supraaortic occlusions (author's transl)].

Internal carotid endarterectomy is an effective and longlasting means of preventing cerebrovascular accidents. After 1-16 years it was entirely successful in 97.8% of asymptomatic patients; 79.3% of patients with transient ischemic attacks experienced no further symptoms, 13% were improved. In patients with acute strokes 20% were cured, 70% improved, and 10% unchanged. The follow-up of patients with completed stroke yielded no further neurological deficit. The late results 1-14 years ater reconstruction of the other supraaortic vessels were good in 92,5% of cases.

Adult↗
PubMed1980

Postmortem changes in stereological parameters of cerebral neurons.

The form and size of neurons in the cat cerebral cortex were stereologically investigated intravitally, and 30 sec., 5 hours, and 22 hours postmortem. For comparison, the human cerebral cortex of a 60 year old male subject was deep frozen 16 hours postmortem, and fixed in formalin. The stereologic parameters of the cat experiment included neuronal surface Ai, perimeter LPi, and formfactor fi. In our experiment, the neurons showed swelling and metachromasia 30 sec. postmortem, which disappeared with progressive autolysis. Postmortem neuronal swelling was attributed to circulatory disturbances in the course of fatal cardiac arrest, whereas metachromasia of nucleoli and Nissl bodies appeared together with increased lysosomal acid phosphatase activity. "Dark neurons were only found in the human cerebral cortex fixed by immersion, and are thus recognized as artefact due to fixation. The intravital occurence of "dark" neurons could not be excluded, however. Size and form determinations of the neuronal perikaryon are expected to give additional information on pathologic changes during the aging process of the human brain, especially in senile dementia and organic brain syndrome.

Acid Phosphatase↗
PubMed1980

Comparative studies of neuronal perikaryon size and shape in the aging cerebral cortex.

The stereological investigation comprised three groups of people aged 19 to 44, 65 to 74 and 85 to 94. Perikaryal area and circumference of cortical neurons in the superior part of the cerebral precentral gyrus were determined. Opening classes of single neurons were measured with the Leitz texture analyzer to calculate size and shape. A multivariate statistical procedure allowed comparison of the neuronal parameters between all groups. The measurements yielded smaller perikarya in the oldest group as opposed to larger ones in the young subjects. No differences were seen between young subjects and the 65 to 74-year-old group, which, in contrast, revealed as only group age-dependent changes in cerebral capillaries and small blood vessels. The differences in perikaryal size indicated that senile atrophy of neurons was most apparent in the external pyramidal layer. An influence of decreased motor impulses from the periphery on the atrophic process of neurons with predominant receptor function cannot be excluded.

Adult↗
PubMed1980

Lack of correlation between carcinoembryonic antigen content of tumor extracts and leukocyte migration reactivity of tumor patients.

Tumor extracts varying in carcinoembryonic antigen (CEA) content (0.4--2,280 ng/mg protein) did not affect the reactivity of cancer patients' leukocytes in the leukocyte migration inhibition test (LMIT). In addition, variations in the plasma CEA levels of tumor-bearing leukocyte donors did not influence the frequency of significant LMIT reactivity.

Adenocarcinoma↗
PubMed1980

[Efficiency of postoperative electron therapy for localized cancer of the vulva (author's transl)].

The results from 198 own patients with squamous cell carcinoma of the vulva, having undergone surgical treatment and postoperative irradiation with high-energy electrons and photons, are represented and analysed. The own results are compared to results from the literature obtained by means of larger collectives and of various techniques. A differentiated concept for therapy is presented, taking into account the prognostically important parameters, and integrating surgical and radiation treatment.

Carcinoma, Squamous Cell↗
PubMed1980

[Quantitative-morphological changes of capillaries and neurons in the aging human putamen (author's transl)].

Stereological investigations (Classimat) of the capillary net of 4 age-groups, ranging between 19 and 94 years, revealed significant increase of capillary volume and total length, and decreased intercapillary distances in the aging putamen. Neuronal size and shape measurements (Texture-Analyzer-System) of the same brain region showed significant changes between the young (19-44 y.) and oldest (85-94 y.) group, indicating senile atrophy of the neuronal perikarya. Quantitative image-analysis facilitates to evaluate new morphometrical data of the aging process in the human brain, which are important for a pharmacological concept of treating cerebral insufficiency symptoms.

Adult↗
PubMed1980

[Capillary changes in the brain in aging men and their pathophysiological significance].

In autoptic brains of neurologically and psychiatrically healthy patients, aged between 19 and 94 years, structural changes of capillaries and neurons were stereologically investigtaed in different parts of the brain. The results of the putamen reveal a significant increase of the capillary volume and a decrease of the neuronal perikaryon area with age. The cerebral cortex shows only a slight increase of the capillary length, while the nerve cells are significantly smaller. These results lead to the assumption that a decrease of cerebral circulation in old age might be on one hand a symptom of a decreased nerve cell activity but on the other hand the results of changed stereological capillary parameters due to changes of the volume particularly of subcortical brain structures. In animal experiments with functional changes of the brain by hypovolemic oligemia, ischemia and respiratory hypoxia a correlation between electrical brain activity, oxygen consumption, microcirculation and morphometrical capillary parameters could be demonstrated.

Adult↗