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Biomedical subjects

R Kleinert

Publications and source records attributed to R Kleinert.

At least 91 records · Page 5Linked to original sources
PubMed1986

[Chronic tuberculous meningoencephalitis as a cause of cerebrovascular insufficiency--a differential diagnostic problem].

The often complicated diagnosis in the reason of uncertain primary clinical symptoms, in a chronical prolonged tuberculous meningoencephalitis, in correlation with the demonstration of an exemplary case, in the present study is reported. In addition, in this case the morphological and clinical signs are very uncommon also in cause of uncharacteristically and misleadingly clinical symptoms. The findings in computed tomography and finally also the rarely autopsy findings, like tuberculous ventriculitis and vasculitis are presented. The possibilities of different diagnosis will be discussed, in regard to the literature. The present study should be understood as a contribution to a quick and certain diagnose in tuberculous meningoencephalitis.

Brain Ischemia↗
PubMed1985

Carcinomatous meningeosis as exclusive metastasizing pattern in a malignant thymoma.

In a 57-year-old male patient meningitic symptoms occurred. CSF cytology exhibited carcinoma cells, thus establishing the diagnosis of carcinomatous meningeosis. The primary site of the tumor or metastases were not detected intra vitam. The autopsy revealed a malignant thymoma with an exclusive metastatic participation of the leptomeninges except for some few regional lymph nodes. Cerebral metastases of malignant thymoma is an extremely rare condition.

Brain↗
PubMed1985

Alveolar rhabdomyosarcoma in a young female patient metastasizing to the brain.

A case of 14-year-old girl is reported in whom an alveolar rhabdomyosarcoma occurred in the soft tissues of the left forearm 4 years prior to death. Despite extensive surgery as well as chemotherapy and radiotherapy the tumor recurred locally and produced extensive metastases including a metastasis to the brain. Cerebral metastases have not yet been reported in the literature despite extensive reports on the pathology of alveolar rhabdomyosarcoma. The morphological diagnosis of rhabdomyosarcoma was supported by the immunohistochemical demonstration of desmin, myosin, and myoglobin in the tumor cells.

Adolescent↗
PubMed1983

[Fatal bee sting: 1st report of IgG4-mediated anaphylactic shock].

The author reports on a 39 year-old male patient with allergic asthma who died several hours after a bee sting in a state of shock. While IgE antibodies were not present, distinct deposits of IgG4 antibodies in the kidney and lung were demonstrated for the first time after a bee sting. The intention of this report is to stress the importance of hyposensibilisation of patients with an allergic condition after determination of the relevant class or subclass of immunoglobulins.

Adult↗
PubMed1983

Mitochondrial reaction in skeletal muscle to induced activity.

The purpose of the present study was to investigate the structure of muscle mitochondria for a possible early response to electrically induced short- and medium-term activity. Rats were anesthetized with Na-pentobarbital. Both parts of the triceps surae muscle were stimulated by direct electrical impulses for periods between 2 and 60 min. Biopsies were taken and prepared for histological, enzyme-histochemical, and electron-microscopic examinations. Enzyme histochemistry demonstrated an increase of oxidative activity and an increase of RNA by NADH-tetrazolium reductase and modified Gomori's trichrome staining or acridine orange-induced fluorescence, respectively. These changes appeared especially within type I fibers, as shown by ATPase reactions, and corresponded to an increase in number and size of muscle mitochondria, followed by alterations of the mitochondrial structure. The mitochondria reacted immediately to the electrical stimulation of the muscle, and the degree of alteration depended on the duration of the experiments. These results suggest that mitochondria have a certain capacity for adapting rapidly to changes in the energy metabolism. Beginning energetic decompensation may be responsible for the alterations of the mitochondrial structure.

Animals↗
PubMed1980

Assessment of emetine cardiotoxicity in a subacute toxicity experiment in rats.

We explored the usefulness of cardiovascular function studies for the detection and characterization of emetine cardiotoxicity in a subacute toxicity experiment. Rats received 1 mg/kg, s.c., emetine five times weekly for up to 7 weeks. In unanesthetized animals, statistically significant changes of the electrocardiogram (EKG) appeared in the following sequence: prolongation of QRS interval (5th day), flattening of T wave (beginning of 4th week), and prolongation of PR interval (end of 4th week). Terminal cardiovascular studies were conducted under urethane anesthesia. EKG changes were comparable to those recorded in conscious rats, but no decrease in T wave voltage occurred. Blood pressure and heart rate remained unchanged. Cardiac output was decreased after 5 and 7 weeks of treatment, when heart weights were also significantly reduced. The response of cardiac output and mean arterial blood pressure to intravenously injected norepinephrine and epinephrine remained unchanged. Catecholamine-induced arrhythmias occurred less frequently in emetine-treated animals than in controls. No significant structural lesions of the heart muscle were detected by light microscopy. The cardiotoxic effects observed in rats were similar to those reported in humans receiving the usual therapeutic dose of approximately 1 mg/kg/day. We conclude that cardiovascular function studies can make an important contribution to the predictive value of animal toxicity experiments.

Anesthesia↗
PubMedDate not supplied

Lectin binding in meningiomas.

Forty-two meningiomas of different morphological sub-type were examined to determine their pattern of binding to 11 different lectins which characterize cell surface components such as carbohydrate residues. Histiocytic and xanthoma cells within meningiomas could be demonstrated with six different lectins: wheat germ agglutinin (WGA), peanut agglutinin (PNA) Bauhinia purpurea agglutinin (BPA), Helix pomatia agglutinin (HPA), Vicia fava agglutinin (VFA) and Soyabean agglutinin (SBA). Vascular elements including endothelial cells and intimal cells, bound Ulex europaeus agglutinin type 1 (UEA 1), WGA and HPA. The fibrous stroma in fibrous and fibroblastic meningiomas bound PNA, Laburnum alpinum agglutinin (LAA) and SBA. Tumour cells in meningotheliomatous meningiomas and some areas of anaplastic meningiomas bound Concanavalin A, PNA, LAA and VFA whereas tumour cells in fibrous and fibroblastic meningiomas bound BPA, LAA and VFA. Lectin binding has proved to be of value in detecting histiocytic and xanthoma cells together with vascular elements within meningiomas. In addition, the different lectin binding patterns allow different histological sub-types of meningioma to be distinguished although the biological significance of the binding patterns is unclear.

Histiocytes↗
PubMedDate not supplied

Dysontogenetic brain tumours--proposal for an improved classification.

The International World Health Organisation (WHO) classification of central nervous system tumours does not give an extensive classification of germ cell tumours and other malformative tumours and tumour-like lesions. In the same way, no consistent classification of dysontogenetic brain tumours can be found in the classical handbooks. For an eventual new edition of the WHO classification, it is proposed to reconsider and improve the classification of these tumours, based on their ontogenetic relations.

Brain↗
PubMedDate not supplied

Pleural and bone marrow metastasis from supratentorial oligoastrocytoma grade III.

We report a 62-year-old man with symptomatic metastasis to the pleural cavity and the bone marrow from a supratentorial oligoastrocytoma grade III, 24 years after the initial symptoms. Before tumor dissemination, the patient underwent brain surgery four times in 5 years. Six months after the last treatment, extraneural dissemination to the right pleural cavity was discovered. Despite resection of the pleural metastasis, local and distant spread to the bone marrow developed. The patient died 5 months after the occurrence of extraneural tumor metastasis. It is speculated that repeated brain surgery and extended survival may promote extraneural dissemination of supratentorial oligoastrocytoma grade III.

Astrocytoma↗
PubMedDate not supplied

Prostaglandin E1 reduces the frequency of rejection after heart transplantation.

This retrospective study was carried out to evaluate the effect of prostaglandin E1 on the frequency of rejection in 36 heart transplant recipients who survived orthotopic heart transplantation for 60 days or longer. The therapy for both groups was the same except group 1 (n = 12) was given PGE1 for 6 to 14 days. Indication for the PGE1 was right ventricular mismatch or failure. The prostaglandin administration started during the transplantation procedure. The dosage was 28 to 64 ng/kg/min and was tapered down from 14.7 to 32 ng later. No major side effects related to PGE1 have been observed. During the first 60 days after heart transplantation, in the group treated with prostaglandin, rejection grade 2 or higher was evident in 0.91 biopsies/patient versus 2.2 in nontreated patients, (p less than 0.05). A prolonged interval free from rejection (p less than 0.05) was observed in the patients treated with prostaglandin.

Alprostadil↗
PubMedDate not supplied

The morphologic correlate of incidental punctate white matter hyperintensities on MR images.

Postmortem examinations were made of the brains of six patients, 52-63 years old, who exhibited incidental punctate white matter hyperintensities on MR images before death. Our aim was to unravel the morphologic correlate of such lesions. By repeating the MR study after fixation on four specimens, cutting the brain parallel to the MR imaging plane, and examining whole-hemisphere microscopic sections, we optimized lesion identification. The white matter signal abnormalities were better delineated on pre- than postmortem scans, and visual inspection of the brain slices was normal in all but one location. Histologically, we found areas of reduced myelination with atrophy of the neuropil around fibrohyalinotic arteries as well as different stages of perivenous damage. The latter ranged from spongiform transformation of the neuropil and scattered foci of demyelination to large perivenous areas with marked rarefaction of myelinated fibers. Edematous glial swelling in foci of ganglion cell heterotopia caused subcortical white matter hyperintensities in one case. Our results suggest minor perivascular damage but not infarction as the most likely substrate of punctate MR white matter hyperintensities in elderly brains. Histologic correlations with MR images obtained during life or with studies of unfixed material are necessary to analyze such small lesions.

Brain↗
PubMedDate not supplied

MR findings in methotrexate-induced CNS abnormalities.

MR of the brain was performed in eight patients (mean age, 14.9 years) with osteogenic sarcoma during or after IV treatment with high-dose methotrexate. MR detected brain abnormalities in four patients, three of whom had concomitant neurologic dysfunction. Pathologic findings demonstrated on MR were (1) chronic brain edema, demonstrable over a period of 3-14 months (proved by autopsy in one patient); (2) multifocal white matter necrosis; and (3) deep brain atrophy. MR appears to be valuable in the detection of abnormalities induced by treatment with high-dose methotrexate.

Adolescent↗