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Biomedical subjects

M Klein

Publications and source records attributed to M Klein.

At least 523 records · Page 29Linked to original sources
PubMed1989

[Echographic localization diagnosis of enlarged parathyroid glands].

The authors report on their own experience with the localization of enlarged parathyroid glands by sonography. In a study of 248 patients with hyperparathyroidism, they obtained a sensitivity of 57% and a specificity of 81%, with an overall accuracy of 74%. These results are discussed in detail.

Humans↗
PubMed1989

Juxtacortical liposarcoma. A case report and review of the literature.

Juxtacortical liposarcoma is an uncommon entity. The purpose of this paper is to report the case of a 63-year-old man with juxtacortical liposarcoma. Liposarcomas arising as surface lesions of bone are extremely rare. Histologically, juxtacortical liposarcoma is composed of myxoid and round-cell areas. Because of the extent of compartmental involvement and the high-grade malignancy, limb-sparing surgery was not considered for the patient. A review of the English literature on diagnosis and treatment indicates a grave prognosis.

Femoral Neoplasms↗
PubMed1988

[Metachronous double carcinoma of the large intestine].

Seven patients developed two separate carcinomas of the colon over an average interval between the two of 8.5 years. Five of the second tumours were discovered during routine endoscopic follow-up of the first. Ten of the 14 tumours were located in the left colon. These seven cases represent an incidence of metachronous double carcinoma of the colon of 0.9% among a total of 762 patients with carcinoma of the colon seen during the same period. Two patients died of the malignancy seven and 24 months, respectively, after the operation. The others have so far remained clinically free of tumour.

Aged↗
PubMed1988

Combination chemotherapy and alpha-interferon in the treatment of Kaposi's sarcoma associated with acquired immune deficiency syndrome.

Thirteen men with a median age of 37 (range 28 to 46) years who had extensive Kaposi's sarcoma associated with acquired immune deficiency syndrome (AIDS) were treated with combination chemotherapy and alpha-interferon. Four patients had stage III disease and nine had stage IV disease (one with pulmonary and eight with gastrointestinal involvement). Treatment consisted of monthly courses of actinomycin D, 1 mg/m2, and vinblastine sulfate, 6 mg/m2, given intravenously on day 1, bleomycin, 10 mg/m2 given intravenously on days 1 and 8, and human lymphoblastoid (alpha-) interferon, 10 million U/m2 given subcutaneously three times a week for six doses starting on day 14. Forty-one treatment cycles (median 3, range 1 to 12) were administered. The median granulocyte and platelet counts on day 14 before the start of interferon therapy were 600 X 10(9)/L and 134 X 10(9)/L respectively; the counts did not fall further during interferon therapy. There was no difference in T-cell subsets, 2',5'-oligoadenylate synthetase level or results of blastogenesis studies after interferon therapy. Four patients required admission to hospital for neutropenia-associated fever. A complete response (of 24 weeks' duration) was seen in one patient and a partial response (of 14 to 44 weeks' duration) in four. One patient had a mixed response, with regression of skin involvement but progression of pulmonary disease. The median length of survival was 48 (range 4 to 143) weeks. Eleven patients died of progressive Kaposi's sarcoma, one of lymphoma and one of Pneumocystis carinii pneumonia. The results suggest that this form of therapy is not appropriate for patients with Kaposi's sarcoma associated with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Dextromethorphan binding sites in the guinea pig brain.

1. Dextromethorphan (DM), a dextrorotatory nonopioid antitussive, binds to specific high-affinity sites in the central nervous system. These sites are distinct from the opioid and other known neurotransmitter receptor sites. Antitussives such as carbetapentane and caramiphen also bind to DM sites with a nanomolar affinity. 2. The anticonvulsant drugs phenytoin and ropizine produce an allosteric enhancement of the binding of [3H]DM to guinea pig brain. DM, carbetapentane, and caramiphen also are efficacious anticonvulsant agents in the rat maximal electroshock seizures test, and DM enhances the anticonvulsant effects of phenytoin (PHT). 3. These results suggest that drugs that bind to the DM sites could be used alone as anticonvulsants or in combination with PHT to lower its effective dose and reduce its side effects. 4. The investigation of the DM binding sites may help to open new approaches for the treatment of convulsive disorders and to explain further some of the molecular mechanisms of neutronal excitability.

Animals↗
PubMed1988

Gamma-vinyl GABA: comparison of neurochemical and anticonvulsant effects in mice.

Biochemical and pharmacological effects of gamma-vinyl GABA (Vigabatrin, GVG), and irreversible enzyme-activated inhibitor of 4-aminobutyrate: 2-oxoglutarate aminotransferase (EC 2.6.1.19; GABA-T), were measured in mice. This anticonvulsant produced a time- and dose-dependent elevation of the GABA, phenylalanine and lysine contents of cortical tissue and simultaneously decreased glutamate, aspartate and alanine levels. In addition, GVG caused a biphasic change in glutamine concentrations (a decline 1-4 hours after administration, followed 20 hours later by an increase). Moreover, we found a new, as yet unidentified amino acid in the brain eluting with the same retention time as alpha-aminoadipic acid from an HPLC cation-exchange column. The level of this novel chemical entity was greatly increased by GVG 20 hours after injection of the drug. At all tested intervals between 1 and 60 hours after injection, GVG was ineffective against maximal electroshock. The GABA-T inhibitor dose-dependently protected mice against isoniazid-induced seizures, simultaneously causing an increase in brain GABA concentrations. However, this apparent correlation applied only until 4 hours after treatment. To better define the anticonvulsant profile of GVG, groups of mice were treated, 1, 2, 4, and 24 hours prior to challenge with convulsant doses of strychnine, pentetrazole (PTZ), and picrotoxin, and brain amino acid levels, including brain concentrations of GVG, were measured. In all instances, the time dependency of the anticonvulsant effects of GVG and of increases in brain GABA levels differed. Amino acid concentrations in animals treated only with GVG were similar to those in animals given GVG and a chemical convulsant. GVG showed no selectivity for seizures produced by impairment of GABA-ergic neurotransmission. Although GVG is an effective GABA-T inhibitor, it apparently affects several other pyridoxal-phosphate-dependent cerebral enzymes and/or interacts with other neurotransmitter systems as well.

4-Aminobutyrate Transaminase↗
PubMed1988

Evaluation of the anticonvulsant and biochemical activity of CGS 8216 and CGS 9896 in animal models.

CGS 8216, a benzodiazepine-receptor ligand with inverse agonistic properties, and CGS 9896, which possesses partial agonistic or mixed agonist-antagonist properties were compared in a number of epilepsy models. The effect of CGS 9896 on the decrease in GABA levels induced by isoniazid was also investigated. CGS 9896 inhibited the kindling process in rats in that it delayed the development of overt seizures and the increase in the duration of afterdischarges. In a genetic rat model characterized by absence-like EEG patterns, CGS 9896 dose-dependently suppressed these spontaneously occurring discharges, while CGS 8216 had no effect. However, CGS 8216 antagonized the anticonvulsant action of CGS 9896. CGS 9896 protected mice against seizures induced by beta-vinyllactic acid, whereas CGS 8216 shortened the latency period before convulsions occurred. CGS 9896 retarded the onset of convulsive fits caused by isoniazid without preventing the decrease in GABA levels produced by that drug. These results confirm the anticonvulsant activity of CGS 9896 and demonstrate the inverse agonistic activity of CGS 8216. The profile of CGS 9896 in the above tests suggests that it might be an effective anticonvulsant, primarily in absence-type seizures.

Animals↗
PubMed1988

Conjunctival oxygen tension monitoring during a controlled phlebotomy.

A decrease in the conjunctival oxygen tension (Pcjo2) and conjunctival index (Pcjo2/Pao2) has been shown to be an early marker of acute blood loss. We sequentially measured Pcjo2, Pcjo2/Pao2, blood pressure, and pulse rate in five healthy adults after controlled phlebotomy of 450 mL and after intravenous fluid repletion. No significant changes occurred in either the Pcjo2 or Pcjo2/Pao2 after phlebotomy or after fluid replacement. We conclude that a blood loss of 450 mL in healthy, euvolemic adults is insufficient to perturb the conjunctival index. The lower limits of sensitivity of changes in Pcjo2 and Pcjo/Pao2 in response to acute blood loss remain to be established.

Adult↗
PubMed1988

[Methodologic studies for the measurement of kinetic parameters of the metabolism of whole body protein in association with measurements of energy metabolism in rats].

In 3 successive experiments with growing rats the suitability of pulse labelling with [15N]glycine, linked with a 14C labelling by means of [14C]lysine (experiment 3), was tested for the determination of kinetic parameters of the protein metabolism of the whole body by the application of the compartment model in comparison with pulse labelling with a 15N amino acid mixture (experiment 2) and long-time labelling with 15N with 15N labelled wheat in the feed (experiment 1) under standardized experiment conditions. In simultaneously carried out measurings of energy metabolism with parallel groups of animals the comparability of the metabolic development was studied. The ascertained values of protein synthesis rate, protein catabolism rate and re-utilization rate showed insignificant differences only between the 3 15N tracer variants (with certain limitations for the 'protein turnover' (P)-group of experiment 2) in comparison with errors of the applied methods, from which conclusions can be drawn for the suitability of [15N] glycine as tracer, at least under the experiment conditions tested. The protein synthesis and degradation rates ascertained from 14CO2 excretion in experiment 3 were clearly below those average values ascertained with 15N. The differences in the average heat production between the main periods of the 3 experiments were statistically insignificant.

Animal Feed↗
PubMed1988

Anticonvulsant-induced marrow suppression and immune thrombocytopenia.

Phenytoin and carbamazepine are rarely associated with serious hematologic side effects but can include impairment of either humoral or cell-mediated immunity. We describe a patient who developed severe granulocytopenia while taking phenytoin. The phenytoin was replaced by carbamazepine and the patient subsequently developed erythroid hypoplasia, neutropenia and persistent thrombocytopenia. In vitro studies demonstrated a phenytoin-dependent antigranulocyte antibody directly implicating phenytoin in the leukopenia. An extremely high titre of platelet-associated IgG was found which was independent of the presence of carbamazepine. Autoantibodies directed against the patient's red cells, granulocytes and lymphocytes were also demonstrated. In vitro marrow culture studies failed to detect cellular or humoral inhibitors and were suggestive of a stem cell defect. These studies indicate that anticonvulsant therapy can result in sustained humoral abnormalities as well as in nonimmune mediated marrow suppression.

Antigen-Antibody Complex↗
PubMed1988

Reduction of neonatal blood eliminates the error induced by oxygen saturation in the spectrophotometric measurement of carboxyhaemoglobin.

Blood carboxyhaemoglobin (COHb) is a sensitive index of haemolysis and has been used in assessing the cause of different types of neonatal jaundice. Although the introduction of automated spectrophotometry provides rapid and accurate measurement in adult blood, in neonates oxygenated foetal haemoglobin (HbF) is thought to interfere with COHb measurement. In an attempt to eliminate this problem, the haemoglobin in neonatal blood was reduced with sodium dithionite. Cord blood from 50 infants was measured before and after reduction using an IL-282 co-oximeter; COHb levels fell after reduction. A significant positive correlation was found between apparent COHb% and oxygenation of cord blood. In contrast, no significant correlation was found between these parameters in adult blood where COHb values remained the same or rose slightly after reduction. In 20 healthy non-icteric neonates the mean reduced blood COHb value was not significantly different from the mean COHb value of 23 healthy non-smoking adults. We suggest that COHb in neonatal blood can be simply and accurately measured by the IL-282 co-oximeter provided that the blood is fully reduced.

Adult↗