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Biomedical subjects

P Manowitz

Publications and source records attributed to P Manowitz.

At least 37 records · Page 2Linked to original sources

Neuropsychological deficits in obligatory heterozygotes for metachromatic leukodystrophy.

Two groups of heterozygotes, one for metachromatic leukodystrophy (MLD) and the other for Tay-Sachs disease, were given a battery of neuropsychological tests, a standard neurological examination, and an EEG. Neurological and EEG findings were unremarkable for both groups. The MLD heterozygotes showed deficits in the neuropsychological tests involving spatial or constructional components, but not in tests involving language skills. The Tay-Sachs heterozygotes showed no consistent deficit on any component of the neuropsychological tests.

Electroencephalography↗

A new electrophoretic variant of arylsulfatase A.

Previous work in this laboratory has identified electrophoretic variant forms of arylsulfatase A in leucocyte plus platelets. During a study to replicate and extend these findings, a new seven-band variant of arylsulfatase A has been identified. Purified platelets gave a clearer, more distinct electrophoretic banding pattern than the leucocyte and platelet preparations.

Adult↗

Attention deficit disorder and pathological gambling.

To examine the possibility that pathological gambling is related to the deficits in impulse control associated with attention deficit disorder, 14 pathological gamblers and 16 controls were administered questionnaires concerning their childhood behaviors. These self-reports indicated a strong correlation between pathological gambling and childhood behaviors related to attention deficit disorder.

Adult↗

Dopamine and schizophrenia: an analysis of the theory.

The postulated relationship of dopamine to schizophrenia ranks among the most important contemporary theories pertinent to the biological bases of behavior. However, as an examination of the relevant research literature makes clear, the theory has not yet been convincingly validated. This lack of validation is due, in part, to a failure to address the following questions: Is dopamine hyperactivity an etiological and/or a symptom factor in schizophrenia; do laboratory measures used to test the theory truly parallel the relevant clinical phenomena; is attenuated dopamine activity a necessary and/or sufficient condition for remission of schizophrenic symptoms? Analysis of these questions not only provides a departure point for examining the theory, but sets the stage for a reformulation of the theory itself.

Adenylyl Cyclases↗

Differential response of plasma glucose, amino acids and nonesterified fatty acids to insulin in depressed patients.

Levels of plasma glucose, nonesterified fatty acids and total amino acids at various times after insulin administration were determined in patients with either major depressive disorder or dysthymic disorder and in normal control subjects. For the first 30 min following insulin administration, the rate of change in glucose levels was significantly less among the patients with major depressive disorder than among either the patients with dysthymic disorder or the normal control subjects. However, during the same time period, the rates of decline in nonesterified fatty acids and total amino acids were indistinguishable among the three subject groups. Therefore, the insulin resistance in terms of glucose levels that is observed in patients with major depressive disorder is not generalized to other substances affected by insulin.

Adult↗

Free tryptophan response to intravenous insulin in depressed patients.

Levels of free plasma tryptophan, total plasma tryptophan, and total amino acids were determined at various times after insulin administration in patients with either major depressive disorder or dysthymic disorder and normal control subjects. Prior to insulin administration, there were no significant differences among the three groups in any of the parameters. However, following insulin, free plasma tryptophan levels fell significantly among the patients with major depressive disorder for the first 30 min, but not among normal controls. The rate of decline among the patients with dysthymic disorder was intermediate between those of the patients with major depressive disorder and normal controls. The levels of total tryptophan and amino acids following insulin did not differ significantly among the three groups.

Adult↗

Arylsulfatase A activity and electrophoretic banding patterns from isolated human blood fractions.

Arylsulfatase A (ASA) activity was studied from five blood fractions, leukocytes plus platelets (LKPL), leukocytes (LK), neutrophils (N), lymphocytes (LYM), and platelets (PL). No significant difference was found among the mean ASA specific activity values for the fractions. Electrophoretic examination revealed four distinct activity bands for the LKPL and PL fractions, while the LK, N, and LYM fractions showed only a single, broad peak, which indicates that the four-band pattern is associated with enzyme obtained from platelets. The PL fraction gave a clearer, more distinct banding pattern than the other four fractions. This clearly resolved electrophoretic banding pattern of ASA from pure platelet preparations was demonstrated for variant human ASA as well. These findings may be significant to future work investigating the biochemical genetics of ASA.

Arylsulfatases↗

Clinical course of adult metachromatic leukodystrophy presenting as schizophrenia. A report of two living cases in siblings.

Adult metachromatic leukodystrophy is a demyelinating disease due to an inherited lack of arylsulfatase A activity. The purpose of this paper is to present the characteristics of this disorder as they occurred chronologically in two siblings, prior to and subsequent to the appearance of gross neurological deficits. A deficit in spatial relationships, as contrasted with verbal abilities, was observed initially in both cases at age 13. Initial psychiatric symptoms were noted at age 16 and 18, with both patients being diagnosed subsequently as schizophrenic. Gross neurological deficits were observed 2 and 13 years, respectively, after the appearance of psychiatric symptoms. A deficit in spatial relationships may be a very sensitive early indicator of adult metachromatic leukodystrophy.

Adolescent↗

Rat brain and serum lithium concentrations after acute injections of lithium carbonate and orotate.

Eight hours after intraperitoneal injections of 1.0, 2.0, and 4.0m equiv Li kg-1, the serum and brain lithium concentrations of rats were significantly greater after lithium orotate than after lithium carbonate. While little serum lithium remained at 24 h after injection of 2.0 m equiv kg-1 lithium carbonate, two-thirds of the 2 h serum lithium concentration was present 24h after lithium orotate. Furthermore, the 24 h brain concentration of lithium after lithium orotate was approximately three times greater than that after lithium carbonate. These data suggest the possibility that lower doses of lithium orotate than lithium carbonate may achieve therapeutic brain lithium concentrations and relatively stable serum concentrations.

Animals↗

The reaction of 5-hydroxyindoleacetic acid with ortho-phthalaldehyde and cysteine.

The metabolite 5-hydroxyindoleacetic acid, the major metabolic product of serotonin, can be measured by reacting it with orthophthalaldehyde to form a highly fluorescent product. The inclusion of cysteine in this reaction causes an increase in the amount of fluorescence. The rate of fluorescence formation for reaction containing cysteine is much faster than the rate for the reaction without cysteine. The differences observed for both excitation and remission maxima between reaction products formed in the presence and absence of cysteine indicate that these products are different. Furthermore, the significant difference in the regression coefficients of fluorescence of the reaction products versus HC1 concentration adds further evidence that the reaction products formed in the presence and absence of cysteine are different. HC1 appears to influence the reaction of 5-HIAA, OPT and cysteine in several ways: by causing the destruction of 5-HIAA, by affecting the fluorescence of the product formed, and by influencing the amount of reaction product formed.

Aldehydes↗