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Biomedical subjects

M Steiner

Publications and source records attributed to M Steiner.

At least 433 records · Page 24Linked to original sources
PubMed1981

Detection of platelet alloimmunity with a platelet-associated IgG assay.

A quantitative immunofluorescence PA-IgG assay was used to detect alloimmunity to platelets. The assay identified serum alloantibodies in 10 out of 14 multitransfused patients and for two of three infants with neonatal thrombocytopenia. The correct separation of all multitransfused patients into alloimmune and nonalloimmune groups by the PA-IgG assay was substantiated with chromium-51--labeled platelet survival studies. The allogeneic nature of the serum antibodies was demonstrated by progressive absorption of the antibody with increasing numbers of allogeneic platelets but not with autologous platelets. The sensitivity of the PA-IgG assay for detection of serum alloantibodies was superior to that of platelet aggregation, platelet serotonin release, and lymphocytotoxicity testing. In dilution experiments with alloimmune serum, elevated levels of serum PA-IgG could still be detected on donor platelets when platelet aggregation and serotonin release tests became negative. Platelet survival studies with selected platelets performed in the 10 alloimmunized, multitransfused patients confirmed the results of the PA-IgG assays, predicting alloimmunity to the donor platelets. In contrast, platelet aggregation, platelet serotonin release, and lymphocytotoxicity testing indicated alloimmunity for 50% or less of the patients. Reduced platelet survival times were also seen with HLA A- and HLA B-matched donor platelets when donor-recipient incompatibility was demonstrated by the PA-IgG assay. Thus the PA-IgG assay provides a sensitive method to detect serum platelet alloantibodies and may offer a technique in platelet crossmatching.

Absorption↗
PubMed1981

[Swiss studies on the effects of prophylactic treatment of dental caries in children (author's transl)].

The gradual introduction of various measures of fluoridation in different cantons facilitated studies of a quasi-experimental type on schoolchildren. The use of a standardized method for obtaining the customary indices of dental caries provided data suited for comparison between the experimental and the control communities. On a general basis, the strongest reduction of caries prevalence was obtained by means of fluoride in water (canton of Basle) and in salt at the optimal concentration of 250 mg/kg (canton of Vaud). At school age, prevention of caries should be combined with the prevention of periodontitis and necessitates the use of a comprehensive policy for dental health.

Adolescent↗
PubMed1980

Flourescence studies of platelet tubulin.

Temperature-related changes in tubulin conformation were investigated by several flourospectroscopic methods utilizing steady-state flourescence techniques. Tubulin was isolated from human platelets by three cycles of temperature-dependent polymerization-depolymerization. 8-Anilino-1-naphthalenesulfonate (ANS) was used as a probe of polarity of tryptophanyl fluorescence in tubulin. The microtubule protein displayed definite differences at 4 and 37 degrees C. While the total number of ligand sites was the same, differences in the binding affinity of ANS were noted. Acryamide, a discriminating and efficient quencher of intrinsic protein fluorescence, also revealed temperature-dependent changes in the exposure of trypthophanyl residues of tubulin. ANS-induced quenching was associated with a transfer of energy from tryptophanyl residues to this fluorophor which could be used to calculate a critical distance between the acceptor-donor pair. The temperature-related changes were not found to be contingent upon the presence of polymerized tubulin.

Anilino Naphthalenesulfonates↗
PubMed1980

Charcterization and measurement of normal platelet-associated immunoglobulin G by fluorospectrophotometry.

Platelet-associated immunoglobulin G of normal healthy subjects was measured and its binding characteristics studied by use of a newly developed assay which is rapid, quantitative, sensitive and inexpensive. The assay is based on fluorospectrophotometry. Fluorescein isothiocyanate was used as a fluorescent marker to label IgG. Measurement of platelet-associated IgG by this method showed that normal platelets have at least two types of binding sites for IgG of normal healthy subjects. High- and low-affinity binding sites numbering 410 +/- 200 and 1800 +/- 500, respectively, were identified. Specificity of binding was shown by competition between fluorescein isothiocyanate-labeled IgG and nonlabeled IgG. The effect of pH and temperature and the kinetics of binding were also investigated.

Binding Sites↗
PubMed1980

Persistently negative tuberculin reactions: their presence among children with culture positive for Mycobacterium tuberculosis (tuberculin-negative tuberculosis).

Mantoux tests were performed on 200 children with culture-proven Mycobacterium tuberculosis infections. A group of 28 patients initially had negative reactions to 5 TU PPD-S. Of these, 17 had had extensive or overwhelming tuberculous disease at the time of admission, seven of whom reacted to 250 TU PPD; after a course of chemotherapy, all the survivors had positive reactions to 5 TU PPD-S. The 11 with less severe disease had negative reactions to 5 TU PPD-S and 250 TU PPD, as well as to PPD-A/B/G; in only two could a ready explanation be found for the negative reactor state. In general, a small number of children without life-threatening forms of tuberculosis may have persistently negative tuberculin reactions without any apparent cause. In such cases, other criteria for diagnosis must be relied on, such as lymphocyte transformation, culture, and biopsy.

Adolescent↗
PubMed1980

Behavioral effects of dopamine agonists across the estrous cycle in rats.

The effects of apomorphine upon stereotypy and bromocriptine upon wheel running and intracranial reward were examined across the estrous cycle of female rats. Apomorphine elicited sterotypy in a dose-related fashion, but sterotypy was not reliably or systematically altered by estrous conditions. On the other hand, wheel running was augmented by bromocriptine in an estrous-specific fashion. Self-stimulation was increased by bromocriptine but this was not related to estrous cyclicity. These findings provide evidence for possible behavioral and motivational specificity of dopamine (DA) receptor-related estrous changes.

Animals↗
PubMed1980

Diagnosis of endogenous depression. Comparison of clinical, research and neuroendocrine criteria.

Eighty-nine depressed outpatients were studied by clinical criteria, Research Diagnostic Criteria (RDC), and the dexamethasone suppression test (DST) of neuroendocrine regulation. A simple outpatient version of the DST, requiring only one blood sample, correctly identified 40% of patients diagnosed clinically as endogenous depression (ED), with a specificity of 98% and a diagnostic confidence of 95%. Differences in age, sex, or severity of symptoms between endogenous and non-endogenous depressives did not account for these results. By comparison, the diagnostic performance of the DST was weaker for the RDC categories Major Depressive Disorder (MDD) and primary MDD. These were less selective and more heterogeneous than the clinical category ED. The clinical diagnoses of ED were supported in 98% of cases by the RDC, but 22% of RDC endogenous MDD diagnoses were not supported by the clinical diagnoses. Abnormal DST results were found only in patients with both the clinical diagnosis of ED and the RDC diagnosis of endogenous MDD. Patients with definite endogenous MDD had a significantly higher frequency of abnormal DST results (42%) than those with probable endogenous MDD (14%), or those with other RDC diagnoses (3%). A significant association was found between positive DST results and a positive family history of depression. These results support other evidence for use of a positive DST result as an external validating criterion for ED. The category MDD contained all cases diagnosed clinically as ED, but was diluted by cases diagnosed clinically as non-endogenous depression who had no neuroendocrine disturbance. The results also confirmed that the endogenous/non-endogenous and primary/secondary classifications of depression are not identical. We conclude: (1) that the DST can be used in the differential diagnosis of depressed outpatients as well as inpatients; (2) that the RDC category primary MDD and the Washington University category primary depression are more heterogeneous and probably less valid than the clinical category ED; (3) that the RDC for endogenous MDD have only moderate validity; (4) that RDC diagnoses cannot substitute for careful clinical diagnoses in research studies; (5) that the best use of the RDC is to support clinical diagnoses, but not to generate diagnoses independently as a free-standing system; (6) that the concept of endogenous or endogenomorphic depression has validity and should be retained in research studies of depression.

Adult↗
PubMed1980

Neuroendocrine dysfunction in genetic subtypes of primary unipolar depression.

Disinhibited activity of the hypothalamic-pituitary-adrenocortical (HPA) neuroendocrine system, characterized most specifically by abnormal responses to the dexamethasone suppression test (DST), is observed in 40-50% of patients with endogenous depression. The heterogeneity of endogenous depressives with respect to this neuroendocrine marker is so far unexplained. A recent report from Iowa suggested that genetic factors could account for this heterogeneity, since abnormal DST reponses were found with widely differing frequencies among primary unipolar depressives subtyped by the genetic criteria of Winokur. We studied 14 patients with primary endogenous delusional unipolar depression. Abnormal DST responses were found in 79% of the entire group, and with similar frequencies among each of the Winokur subtypes. In particular, five of six patients (83%) with depression spectrum disease had abnormal DST results. This contrasts with a frequency of 4% reported by the Iowa group. We conclude that disinhibited HPA activity does occur in depression spectrum disease when a delusional endogenous depression is present. Our results and those of the Iowa study could both be consistent with a threshold model of HPA activation. The high frequency of positive DST results in delusional endogenous depressives may be determined by disinhibited central pain mechanisms. Variations in this clinical dimension, combined with variations in threshold for HPA activation by pain mechanisms, could account for the heterogeneity of DST responses among endogenous depressives.

Delusions↗
PubMed1980

Multimodal treatment of a case of obsessive-compulsive neurosis.

A severe incapacitating case of obsessive-compulsive neurosis was treated in hospital with an intense multimodal approach including individual, conjoint marital, and group psychotherapy, behavioral therapy, occupational and recreational therapy, milieu therapy, and medications. The separate treatments appeared to have a synergistic effect. The patient's symptoms decreased dramatically, and he resumed his normal occupational and family functions and responsibilities. At 2-year follow-up, the patient remained well.

Adult↗
PubMed1980

Treatment of premenstrual tension with lithium carbonate. A pilot study.

Some previous reports have suggested that lithium treatment is of benefit to women with the premenstrual tension syndrome (PMTS). In this study 15 women carefully selected for severe PMTS were given lithium carbonate (600-900 mg/day) continuously for three menstrual cycles. Lithium did not affect physical premenstrual symptoms and was ineffective in most women against behavioral premenstrual symptoms. Despite the low dosage most women also experienced significant drug-related side effects. Although a statistically significant improvement was recorded by several symptom rating instruments, this benefit was of no practical clinical value. The three women who responded best to lithium, and who requested continued treatment beyond 3 months, met diagnostic criteria for subsyndromal affective (cyclothymic) disorder. Lithium is not recommended for the average woman with PMTS.

Adult↗
PubMed1980

Premenstrual tension syndrome: the development of research diagnostic criteria and new rating scales.

Research diagnostic criteria for premenstrual tension syndrome (PMTS) are developed using data collected from a study of 42 women who were suffering from severe PMTS but were well at other times. Two specific scales are also devised for rating the severity of PMTS, a 36-item self-report questionnaire and a 10-item scale for use by therapist/researcher. It is proposed that after further evaluation and validation, these instruments may permit more useful comparisons of data on the etiology and treatment of this disorder.

Adult↗