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Biomedical subjects

A Lowenthal

Publications and source records attributed to A Lowenthal.

At least 109 records · Page 6Linked to original sources
PubMed1981

Isolation and identification of 2-oxo-5-guanidinovaleric acid in urine of patients with hyperargininaemia by chromatography and gas chromatography/mass spectrometry.

An unknown guanidino-positive peak has been identified in urines of three sisters affected with hyperargininaemia. Identification was made on the basis of its similarity with the liquid and thin-layer chromatographic characteristics of enzymatically synthesized 2-oxo-5-guanidinovaleric acid. Identification was also made by combined gas chromatography-mass spectrometry of the unknown compound peak. The synthesis of enzymatically formed 2-oxo-5-guanidinovaleric acid was controlled by nuclear magnetic resonance and combined gas chromatography-mass spectrometry.

Amino Acid Metabolism, Inborn Errors↗
PubMed1980

Immunochemical determination and immunocytological localization of brain-specific protein alpha-albumin (GFA) in isolated astrocytes.

Astrocyte- and neuron-enriched fractions were isolated by preparative centrifugatin from rat brain and human brain, obtained at autopsy. The brain-specific protein alpha-albumin (GFA) was studied in these fractions by quantitative immunoradiochemical and by immunocytological methods. It is concluded that morphologically intact astrocytes can be isolated not only from rat, but also from human brain. In the rat, alpha-albumin (GFA) is only found in the astrocyte-enriched fractions; this shows that detemination of alpha-albumin (GFA) is useful for the evaluation of cell separation methods for the brain. From the astrocyte-enriched fractions, four times more alpha-albumin (GFA) can be extracted when detergent (0.1% SDS) is used, than when an aqueous extract is made. About +/- 0.15 X 10(-6) particles were extracted in 1 ml of either PBS or SDS/PBS. This suggests that alpha-albumin (GFA) exists in at least two forms, one hydrosoluble, and one detergent soluble, possibly structurally bound, form.

Albumins↗
PubMed1979

A two-site immunoradiometric assay for the determination of alpha-albumin.

A two-site immunoradiometric assay for a brain specific protein (alpha-albumin or glial fibrillary acidic protein) is described which may be applied to other proteins. The assay variables studied are immunoadsorbent dilution, temperature, incubation times, reactivity of the labelled antibodies and effect of the washing. Each of these factors is optimalised, resulting in a sensitive, specific, reliable assay. The working range is 5--5000 ng/ml, the within-assay variance is 5%. No high dose hook effect is seen in this range. The method is applied for the measurement of alpha-albumin present in cerebrospinal fluid, nervous tissue extracts and cell cultures.

Albumins↗
PubMed1979

Familial cerebellar ataxia with hypogonadism.

A brother and sister with congenital cerebellar ataxia, anosmia, oligophrenia, hypogonadism and anomalies of amino acid distribution are reported. Ties between the different symptoms are difficult to establish. It seems to be a new syndrome rather than a new disease. Once more these associations emphasize the need for metabolic and biochemical research in heredodegenerative diseases. The evolution of the disease in these cases might make it possible to classify and locate it more accurately.

Adult↗
PubMed1979

Diagnostic value of brief microzone electrophoresis of unconcentrated CSF and agar gel electrophoresis of concentrated and unconcentrated CSF.

This paper reports a comparison between brief microzone electrophoresis and agar gel electrophoresis of CSF proteins; 41 different CSFs were examined simultaneously by all three methods. Fractionation of gamma-globulins was found by brief microzone electrophoresis in 53.7% of unconcentrated CSF. This fractionation was found in 63.4% of unconcentrated CSF after agar gel electrophoresis, in 48.8% of concentrated CSF. Serum-like pherogram and the rapid alpha-globulin type were found equally often.

Cerebrospinal Fluid Proteins↗
PubMed1979

Arginase and free amino acids in hyperargininemia: leukocyte arginine as a diagnostic parameter for heterozygotes.

Arginase activity and free amino acids were measured in plasma, erythrocytes and leukocytes of patients with hyperargininemia and in controls. There is no arginase activity in the leukocytes and erythrocytes of homozygous patients; in heterozygotes it is normal to low. The activity is 50 to 100 times higher in leukocytes than in erythrocytes. In controls as well as in patients and heterozygotes, the amino acid concentrations are higher in leukocytes than in plasma and erythrocytes. In addition to the increased arginine in the three blood compartments (the result of an arginase deficiency), there is also an obvious decrease of aspartic acid in the erythrocytes of the patients. The arginine concentration in leukocytes of heterozygotes is as high as in homozygotes and can therefore be used as a diagnostic parameter for heterozygotes.

Amino Acid Metabolism, Inborn Errors↗
PubMed1978

Multiple sclerosis: oligoclonal IgG, kappa-lambda light chain distribution and measles antibodies in brain extracts.

The presence of measles antibodies in white and grey brain material and in 8 demyelination plaques from 6 patients affected with multiple sclerosis was investigated with the hemagglutination inhibition (HI) and complement fixation (CF) techniques. White and grey matter of 5 controls were run in parallel. No measles antibodies could be detected, except for one plaque, where the answer could be considered as doubtful. The immunoglobulin G (IgG) content and the kappa/lambda light chain ratios of all the samples were evaluated. No unique monoclonal immunoglobulin population could be detected, but kappa or lambda predominant oligoclonal populations appeared in controls as well as in MS IgG.

Antibodies, Viral↗
PubMed1978

Oligoclonal immunoglobulins, light chain ratios and free light chains in cerebrospinal fluid and serum from patients affected with various neurological diseases.

Several immunological parameters, of which the most important are the kappa-lambda ratios, the presence of free light chains and the double ring formation for kappa-chains in single radial immunodiffusion, were investigated in the cerebrospinal fluid and serum of patients affected with different neurological diseases. Parallels were run either with multiple sclerosis or subacute sclerosing panencephalitis. There seems to be a correlation between the frequency of the presence of free light chains and the degree of severity of the immunological process.

Humans↗
PubMed1978

[Non-leukemic disease of the central nervous system in children with acute lymphoblastic leukemia. III. Subacute sclerosing panencephalitis (author's transl)].

Diseases of the central nervous system (CNS) occurring during treatment of acute lymphoblastic leukemia (ALL) may be of leukemic or nonleukemic origin. Well known examples for CNS disease of nonleukemic origin are somnolence following prophylactic CNS irradiation, methotrexate-induced encephalopathy and acute infections caused by bacteria, viruses and toxoplasma gondii. Less known is the fact that also subacute CNS infections may occur in patients undergoing cytostatic therapy. Progressive multifocal leukoencephalopathy and subacute sclerosing panencephalitis (SSPE) are examples of this category of disease. Up to now 11 well documented cases of SSPE were reported occurring during treatment of ALL. Main clinical features were disorders of behaviour, consciousness and speach, seizures, paresis and inappropriate secretion of ADH. Several authors were able to demonstrate a deficiency of cellular immunity in patients with SSPE. In some cases this deficiency was consistent with reduced reactivity of T-lymphocytes against measles antigen only. The presence of inhibiting factors may be responsible for this phenomenon. Other authors found a normal or increased function of cellular immunity in SSPE; In hamsters occurrence of SSPE is induced by the simultaneous injection of hamster-adapted SSPE virus and antihamster lymphocyte serum. We, therefore, conclude that also in humans SSPE appearing during treatment of ALL is due to immunosuppression.

Animals↗
PubMed1977

A morphological and chemical study of calcification of the choroid plexus.

Human choroid plexus was submitted to low temperature ashing (LTA) in order to isolate the calcification. The ashing residue was then subjected to morphological, chemical and structural studies using technics such as scanning electron microscopy, flame and flameless atomic absorption spectrometry, infrared spectrometry and X-ray diffraction. Morphologically, the calcification consisted of wound-up fibers forming granules with a diameter of 0.05 to 0.15 mm. The concretions were identified as cristalline Ca3(PO4)2 and hydroxylapatite. The content of trace elements was high, but within the limits found in other biological apatites. In some cases, however, the Fe content exceeded these limit values.

Calcinosis↗
PubMed1977

A heat stable serum inhibitor of an antigen antibody reaction of subacute sclerosing panencephalitis.

A factor which inhibits the antigen antibody reaction was isolated from the sera of patients affected with subacute sclerosing panencephalitis (SSPE), multiple sclerosis (MS) and also of control subjects. This factor inhibits the immune reaction between SSPE serum IgGs and measles virus. This inhibiting factor was detected in the alpha globulin region after agar gel electrophoresis, and is heat stable at 100 degrees C for ten minutes.

Antigen-Antibody Reactions↗
PubMed1977

A morphological and chemical study of calcification of the pineal gland.

A general scheme of analysis for the investigation of minute calcification is presented. After low temperature ashing, the samples are subjected to chemical, structural and morphological study, using atomic absorption spectrometry, infrared spectrometry, X-ray diffraction and scanning electron microscopy. Details about the calcification of the human pineal gland are given. The content of trace elements is very high, but within the limits found in other biological apatites. It is concluded that calcification of the pineal is a more general occurence than has been realized.

Brain Diseases↗