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Biomedical subjects

M Baron

Publications and source records attributed to M Baron.

At least 199 records · Page 11Linked to original sources

Platelet monoamine oxidase activity and genetic vulnerability to schizophrenia.

Platelet monoamine oxidase (MAO) activity, determined in 102 patients with chronic schizophrenia, 223 first-degree relatives, and 88 normal control subjects, was shown to be a heritable and stable trait and was significantly lower in patients than in normal control subjects. Within families, MAO activity distinguished ill from well relatives. However, the considerable overlap in enzyme activity between affected and unaffected individuals limits the usefulness of low MAO activity as a major risk factor in schizophrenia.

Adolescent↗

Effect of calcium mineral solutions on the histamine release from human peripheral leukocytes.

Histamine release from human peripheral leukocytes was studied in patients with urticaria, pollinosis, and psoriasis and compared with the release in normal healthy donors using anti-IgE or the calcium-ionophore A 23187 as stimuli in the presence of three calcium mineral solutions (Frubiase Calcium). It was observed that among 35 donors 29 revealed a calcium dependent inhibition of histamine release. The inhibition was also evident when calcium mineral solution was added to an ongoing histamine release. The membrane biochemical effects of calcium mediated inhibition are currently under investigation.

Basophils↗

Segregation analysis of schizophrenia and related disorders.

Segregation analysis was applied to 79 nuclear families ascertained through chronic schizophrenic probands. Analysis was performed on the diagnosis of schizophrenia alone and on schizophrenia and schizotypal personality disorder (milder phenotype) combined. The models used were the transmission probability model and the mixed model. Because the disease is associated with reduced fertility, all likelihoods were calculated conditional on parental phenotypes. However, compatibility of the mating-type distribution predicted by each model with the observed was also examined. In all analyses, results suggested consistency with genetic transmission. In the analysis of schizophrenia alone, discrimination among models was difficult. In the analysis including the milder phenotypes, all single-locus models without polygenic background were excluded, while pure polygenic inheritance could not be eliminated. The polygenic model also gave good agreement with supplementary observations (lifetime disease incidences, mating-type distribution, and monozygotic twin concordance). The estimated components of variance for the polygenic model were: polygenes (H) 81.9%; common sib environment (B) 6.9%; random environment (R) 11.2%. Although the polygenic model was parsimonious, segregation analysis and the supplementary observations were also consistent with a mixed model, with a single major locus making a large contribution to genetic liability. Such a locus is more likely to be recessive than dominant, with a high gene frequency and low penetrance. The most likely recessive mixed model gave the following partition of liability variance: major locus, 62.9%; polygenes, 19.5%; common sib environment, 6.6%; and random environment, 11.0%.

Adolescent↗

Plasma amine oxidase and genetic vulnerability to schizophrenia.

Plasma amine oxidase (PAO) activity was studied in 52 chronic schizophrenics, 130 first-degree relatives, and 36 normal control subjects. Enzyme activity was shown to be a heritable and stable characteristic. Age and sex effects were not present. Patients had lower PAO activity than did control subjects, although the difference fell short of statistical significance. Within families, reduced PAO activity was associated with schizophrenia spectrum disorders.

Adolescent↗

67Gallium lung scans in progressive systemic sclerosis.

67Gallium lung scans were performed in 19 patients with progressive systemic sclerosis (scleroderma). Results were expressed quantitatively as the 67Gallium Uptake Index. The mean total pulmonary 67Gallium Uptake Index in patients was significantly higher than that in controls (41 versus 25), and 4 patients (21%) fell outside the normal range. There were no clinical or laboratory variables that correlated with the 56gallium uptake. Increased pulmonary 67gallium uptake in scleroderma may prove useful as an index of pulmonary disease activity.

Adolescent↗

Heterocyclic Quinones. 4. A new highly cytotoxic drug: 6,7-bis(1-aziridinyl)-5,8-quinazolinedione.

With the aim of obtaining new antitumoral agents, a series of 5,8-quinazolinediones was prepared. 5-Amino-6-methoxyquinazoline was oxidized by Fremy's salt to give 6-methoxy-5,8-quinazolinedione. Nucleophilic substitution reaction at C6, electrophilic substitution at C7, and synthesis of 7-amino-6-methoxy-5,8-quinazolinedione, the parent compound of streptonigrin, were studied. These compounds were tested for cytotoxic properties on L1210 leukemia cells in vitro. One of them, 6,7-bis(1-aziridinyl)-5,8-quinazolinedione, which exhibits a high cytotoxic activity (ID50 = 0.08 microM), was further screened in standard antitumor systems, including L1210 leukemia, P388 lymphocytic leukemia, sarcoma 180, and B16 melanocarcinoma. This drug gives a significant antitumoral effect on P388 leukemia but is inactive on other experimental models. Moreover, this compound was found to be highly mutagenic for Salmonella typhimurium TA98 and TA100 strains (Ames test), suggesting that DNA damage could be responsible for its cytotoxicity.

Animals↗

Platelet monoamine oxidase and plasma amine oxidase: effect of anticoagulant and centrifugation technique on platelet yield and enzyme activity.

Platelet recovery and activity of platelet monoamine oxidase (MAO) and plasma amine oxidase (PAO) were determined using different centrifugation procedures (125 g for 15 min vs. 600 g for 2.5 min) and anticoagulants. With either centrifugation procedure, the use of ethylenediaminetetraacetate (EDTA) as anticoagulant resulted in higher platelet yields and MAO activity compared to acid-citrate-dextrose (ACD). However, PAO activity was lower with EDTA as anticoagulant than with ACD. There was a trend toward higher platelet yields and higher activity levels of MAO and PAO with the 125 g centrifugation method than with the 600 g technique regardless of the anticoagulant used. The implications for MAO studies in psychiatric research were discussed.

Adult↗

Age-of-onset in schizophrenia and schizotypal disorders. Clinical and genetic implications.

Age-of-onset data were gathered on 93 chronic schizophrenic probands and 57 affected (mainly schizotypal) siblings. 55% of affected individuals were ill before age 20 and 14% had their onset before age 14. The risk period for schizophrenia and schizotypal personality disorders terminated at age 40. Age-of-onset did not distinguish paranoid from nonparanoid schizophrenics, or definite from probable schizotypal personalities. Schizophrenic and schizotypal subjects were similar in their age-of-onset patterns. Sex effect on age-of-onset was not present. A square-root normal distribution gave the best fit to the data. The implications of these findings for schizophrenia research were discussed.

Adolescent↗

Polarity and sex effect in genetic transmission of affective disorders. The single major locus hypothesis.

A single major locus model of inheritance that incorporates polarity (bipolar-unipolar distinction) and sex effect was applied to family study data on bipolar and unipolar affective disorders. In the model tested, clinical polarity and sex-related thresholds determined a differential liability to major affective illness, whereby unipolar females and bipolar males represented two extremes on a genetic-environmental continuum. Bipolar males were more deviant, and unipolar females were less deviant genetically than bipolar females and unipolar males. The major locus hypothesis did not provide an acceptable fit to the data. The implications of these findings for genetic and biological research in affective disorders are discussed.

Female↗

Familial relatedness of schizophrenia and schizotypal states.

The types and expectancy of mental disorders in the siblings of 74 probands with chronic schizophrenia were examined. The siblings were classified according to whether 1) both parents had schizotypal personality disorder, 2) one parent had the disorder and one was normal, or 3) both parents were normal. Siblings whose parents both had the disorder were at significantly greater risk for schizophrenia and schizotypal personality disorder than siblings with at least one normal parent. Similarly, the expectancy of schizotypal personality disorder alone and combined with schizophrenia was higher among siblings with one parent with the disorder than in siblings with two normal parents. The data suggest that schizotypal traits may be genetically related to schizophrenia.

Adoption↗

Heterotopic ossification heralded by a knee effusion.

A knee effusion suddenly appeared in a 44-year-old woman one month after she suffered a neurological catastrophe. Heterotopic ossification (HO) subsequently developed above her knee. Because treatment of HO with disodium etidronate may be successful if started early, awareness of the association between acute arthritis and new bone formation in certain clinical settings is important.

Adult↗

3H-imipramine platelet binding sites in unipolar depression.

High-affinity 3H-imipramine binding to platelets was determined in 15 drug-free unipolar depressed women and 15 normal controls. The maximum number of binding sites (Bmax) was lower in the depressed population, but the difference fell short of statistical significance (p = 0.07). The dissociation constant for imipramine binding (Kd) was found to be significantly lower among patients than in controls (p = 0.02). The various factors that can affect the in vitro platelet assay, and the implications for affective disorder research, were discussed.

Adult↗

Differential fertility in bipolar affective illness.

The fertility of 134 bipolar probands (60 males, 74 females) was compared with national census data and examined for sex and age-of-onset effects. Fertility was markedly reduced in certain age cohorts in both females and males. When illness onset was taken into account, significant reductions in fertility were observed in the two sexes both before and after onset. The overall reduction in females remained constant over time, but was greater after onset among males. The role of selective forces maintaining affective disorders in the population was discussed in light of genetic and sociodemographic hypotheses.

Adolescent↗

Diagnostic overlap in schizophrenia research: relation to outcome predictors and family history.

Five sets of criteria for the diagnosis of schizophrenia were compared on 47 hospitalized patients who fit New York Research Diagnostic Criteria (RDC) for chronic schizophrenia. The other diagnostic systems used were the Flexible System. Feighner Criteria, New Haven Schizophrenia Index (NHSI), and Taylor-Abrams (TA) Criteria. The NSHI, the broadest system examined, fit all of the patients studied. In contrast, only 30 patients (63% of the sample) were diagnosed schizophrenic using TA Criteria. When the Strauss-Carpenter prognostic scale was used, patients who fit TA Criteria for schizophrenia did not differ in the prognostic scores from the remainder of the sample. In addition, the two groups did not differ in the familial rate of schizophrenia spectrum disorders. The usefulness of narrow versus broad diagnostic criteria in schizophrenia research is discussed.

Adult↗