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Biomedical subjects

H Siemes

Publications and source records attributed to H Siemes.

At least 37 records · Page 2Linked to original sources
PubMed1983

Succinic semialdehyde dehydrogenase deficiency: an inborn error of gamma-aminobutyric acid metabolism.

Gamma-hydroxybutyric aciduria is a disorder of gamma-aminobutyric acid metabolism in which a compound of known neuropharmacologic activity accumulates. We have studied two patients in whom high levels of gamma-hydroxybutyric acid were found in blood, urine and cerebrospinal fluid. A coupled assay has been developed which estimates succinic semialdehyde dehydrogenase activity in isolated human lymphocytes. The mean activity of succinic semialdehyde dehydrogenase in a control and the four parents and two healthy siblings of these patients was 8.8 +/- 1.9 pmol . min-1 . mg-1 protein. In the patients the activities were 0.8 and 1.1 pmol . min-1 . mg-1 protein, approximately 9-13% of control. In the presence of saturating amounts of NAD+, lymphocyte sonicates, derived from the patients accumulated a significant amount of 14C-succinic semialdehyde from 14C-gamma aminobutyric acid, whereas none could be detected in controls. The data suggest a deficiency of succinic semialdehyde dehydrogenase in these patients, the first documented defect of the metabolism of gamma-aminobutyric acid in man.

4-Aminobutyrate Transaminase↗
PubMed1983

Low CSF GABA concentration in children with febrile convulsions, untreated epilepsy, and meningitis.

In 14 children with epilepsy, 51 with febrile convulsions and 22 with meningitis gamma-aminobutyric acid (GABA) concentrations in lumbar CSF were determined. While the mean for CSF GABA concentrations for all epileptic children was unchanged [144 (range: 73-285) pmol/ml; controls: 148 (range: 90-243) pmol/ml] extraordinarily high GABA levels were found in the CSF of two children on valproate (525 and 557 pmol/ml) and remarkably low GABA concentrations in hitherto untreated epileptic children [109 (range: 67-176) pmol/ml]. Children with febrile convulsions [103 (range: 63-170) pmol/ml] and acute meningitis [105 (range: 65-171) pmol/ml] had significantly decreased CSF GABA concentrations (P less than 0.001 and P less than 0.02 compared with controls). The data indicate that valproate intake increases dramatically the GABA concentrations in the CSF of epileptic children. Furthermore, the study supports the concept that low GABAergic activity within the CNS may be one cause for an increased seizure frequency.

Adolescent↗
PubMed1981

GABA in cerebrospinal fluid of children with febrile convulsions.

In 23 children with febrile convulsions the concentration of gamma-aminobutyric acid (GABA) in lumbar cerebrospinal fluid (CSF) was measured by a radioreceptor assay. The mean CSF GABA concentration of 134 (range, 73-294) pmoles/ml was significantly lower than that of 16 seizure-free children serving as controls, who had 210 (range, 117-475) pmoles/ml. The reduction in CSF GABA levels in patients with febrile convulsions was not reflected in plasma GABA concentrations. These data provide further evidence that impairment of GABA neurotransmission may contribute to an increased seizure propensity.

Child, Preschool↗
PubMed1981

Occurrence of oligoclonal gammaglobulin in the CSF of children with prolonged and chronic CNS-infections.

CSF-proteins of 1770 children and adolescents with different neurological diseases and of 75 controls were examined by zone electrophoresis in agarose gel electrophoresis and by immunofixation electrophoresis. The quantitative evaluation of the phoretograms by an analog computer revealed oligoclonal changes of the gamma-globulin profile in 53 patients with subacute or chronic CNS-infections and in 5 children with a medulloblastoma. Seventeen of 37 children with congenital infections had 1--5 oligoclonal gamma-fractions consisting of IgG. Five to seven oligoclonal IgG fractions were detected in each of 16 children with SSPE. All 6 adolescents with multiple sclerosis had 2--5 oligoclonal IgG fractions. One to five oligoclonal gamma-bands occurred transiently in the CSF of 4 children with prolonged meningoencephalitis caused by different viruses, in 3 children with a prolonged non-bacterial meningitis of probable viral origin, in 2 infants with prolonged bacterial meningitis after corticosteroid therapy, and in 1 child with prolonged bacterial meningitis during cytostatic therapy. Four to six oligoclonal gamma-subfractions were found at different times during progressive viral encephalitis that developed during maintenance therapy of acute lymphoblastic leukaemia, and in 2 patients with chronic meningoencephalitis of unknown origin. Since oligoclonal gamma-globulin was detected almost invariably in the CSF of patients with prolonged or chronic neurologic infections, this finding implies persistence of antigens in the CNS and pathologic invasion of lymphocytes with selective proliferation of antigen-stimulated clones.

Adolescent↗
PubMed1981

[Reye's syndrome (author's transl)].

After a viral infection (Coxsackie-A-9) a twelve-year-old boy developed symptoms of acute encephalopathy and fatty degeneration of the liver. A fatal outcome could not be averted. Clinical course, laboratory data, light and electron microscopic examinations were typical for Reye's syndrome, a rare diagnosis in Central Europe.

Adolescent↗
PubMed1980

Changes of CSF-protein pattern in children with acute lymphoblastic leukemia during prophylactic CNS therapy (Berlin protocol).

The cerebral spinal fluid (CSF)-protein profiles of ten children with previously untreated acute lymphoblastic leukemia (ALL) were investigated by agarose gel electrophoresis. The profiles were determined at diagnosis and during the fifth to eighth week of treatment when preventive therapy for central nervous system (CNS) leukemia (skull irradiation, intrathecal methotrexate (ithMTX) was administered. The profiles were compared with those obtained from a control group of 67 children and those from 42 patients with acute aseptic meningitis. The data from the latter group demonstrated the CSF-protein pattern of partial blood-CSF barrier (B-CSF-B) breakdown. The children with ALL showed no or only minor signs of a B-CSF-B impairment at diagnosis and after four weeks of systemic treatment. However, CSF changes indicative of a lesion of the B-CSF-B increased in all children continuously during CNS prophylaxis. The protein profile at the end of combined chemotherapy and radiotherapy was very similar to that in patients with acute aseptic meningitis. These observations point to neurotoxic side effects on the CNS barrier system with the combination of cranial radiation and ithMTX. A striking finding was restricted heterogeneity of gamma-globulin, observed in the CSF of nine out of the ten children with ALL before or during treatment. The significance of this abnormality is unknown.

Antineoplastic Agents↗
PubMed1980

[Brain stem encephalitis (author's transl)].

Basing on a case of brain stem encephalitis in a girl of 7 1/2 years of age, the features of this disease pattern are described. The initially found disturbance of the blood brain barrier provides a clue to the possible pathogenesis of the disease in association with the pattern of clinical signs, namely, an inflammatory-hyperergic reaction of the neurovascular system in the brain stem.

Blood-Brain Barrier↗
PubMed1979

Occurrence of M-proteins in the CSF of a child with prolonged meningococcal meningitis.

CSF of a 4-month-old boy with prolonged, meningococcal meningitis revealed oligoclonal immunoglobulin G about 10 weeks after hospital admission. These proteins persisted for at least 4 months. In contrast to this child, a further 10 infants and young children with bacterial meningitis, whose CSF was examined between 4 weeks and 6 3/4 months subsequent to onset of the disease, showed no such abnormality. Since the presented boy was the only patient treated with a corticosteroid, his altered immune reaction could be related to the immunosuppressive effect of this drug.

Adolescent↗
PubMed1978

Febrile convulsions and blood-cerebrospinal fluid barrier.

Three single CSF proteins with different molecular size (albumin, immunoglobulin G, and alpha2-macroglobulin) were determined by the method of electroimmunoassay in 61 children with febrile convulsions (FC) in order to evaluate the permeability of the blood-CSF barrier (B-CSF-B). Forty-two children with acute extracerebral infection served as controls. In contrast to a group of 22 children who suffered from acute meningoencephalitis or encephalitis, the CSF values of 48 children with FC were within normal limits. Thus even a very mild form of inflammatory encephalopathy-undetectable with conventional CSF investigation-was excluded in the majority of the children with FC. In 11 patients, however, CSF concentrations of albumin and alpha2-macroglobulin were abnormally raised, indicating a B-CSF-B distrubance. Elevated albumin values were found most frequently. In several children with FC lasting more than 20-30 min, B-CSF-B damage was probably caused by prolonged seizure activity since there is a linear correlation between albumin concentration and duration of convulsions. Several other factors known to raise the children's risk of developing epilepsy in later life were associated with the protein pattern of B-CSF-B disturbance in some of the children. In these cases, the cause of abnormal permeability of B-CSF-B is unknown and the condition might have existed prior to the occurrence of seizures.

Albumins↗