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Biomedical subjects

M Singer

Publications and source records attributed to M Singer.

At least 181 records · Page 10Linked to original sources
PubMed1990

Cognitive correlates of adolescents' aspirations to leadership: a developmental study.

The study examined age and gender differences in leadership aspirations among teenage adolescents. It was hypothesized that adolescents' valence, self-efficacy and attribution perceptions about leadership would be predictive of their aspirations to leadership. Altogether 52 fourth form and 78 seventh form high school students completed a questionnaire measuring (a) overall leadership aspirations, (b) 13 valence-instrumentality expectancies for 13 leadership outcomes, (c) self-efficacy perceptions, and (d) attributions of effective leadership. The results revealed significant gender differences in valence scores and significant age differences in self-efficacy and attribution measures. Regression analyses indicated that fourth formers' leadership aspirations were significantly predicted from their "ease-of-success" self-efficacy expectation; whereas seventh formers from either valence perceptions (males) or self-efficacy and attribution scores (females). These results were discussed in the context of the valence and self-efficacy models of career decision-making processes and attribution theory.

Adolescent↗
PubMed1990

Reinventing medical anthropology: toward a critical realignment.

Responding to the narrow focus, medicalization, and inattention to political-economy within conventional medical anthropology, a growing number of researchers are participating in a significant restructuring of the subdiscipline. The paper examines several shortcomings of contemporary medical anthropology and, building on the work of the emergent critical trend, identifies key areas of theory and practice for furthering the critical realignment of medical anthropology.

Anthropology↗
PubMed1990

Enhanced c-myc gene expression during forelimb regenerative outgrowth in the young Xenopus laevis.

Analysis of the expression of the c-myc protooncogene has been carried out in the forelimb regenerate of the Xenopus laevis froglet. Northern blot hybridization analysis revealed the presence of a 2.5-kilobase c-myc transcript in the regenerate forelimb at a level at least 7-fold more than the one found in nonregenerating forelimbs or stumps of regenerating forelimbs. In situ hybridization analyses confirmed the relative abundance of c-myc RNA in the regenerate forelimb and provided evidence of spatial localization of high levels of c-myc RNA in specific cell layers. The deepest layers of the wound epithelium of epidermal origin showed a strong signal, whereas virtually no c-myc RNA was detected in the outermost layers. Labeling was also observed in mesenchymal cells of the blastema where it was relatively evenly distributed. This pattern of c-myc RNA in the regenerate might indicate that the expression of c-myc plays a role in the regulation of the continued proliferation of specific cells of the regenerate, whereas repression of this gene in the epidermis correlates with terminal differentiation of keratinocytes.

Amputation, Surgical↗
PubMed1990

Postmodernism and medical anthropology: words of caution.

Of late, discourse in anthropology increasingly has been set within the frame of postmodernism. While debate continues as to whether postmodernism represents a particular period or an historically conditioned perspective (or interrelated set of perspectives) within the social sciences and beyond, it is clear that assessment is needed of the impact of postmodernism on work within the field. This paper represents a critique of the potential effect of postmodernism within medical anthropology. It is the argument of this paper that despite the postmodern eschewal of so-called grand theory, postmodern writers in anthropology smuggle a theoretical perspective into their work. The problems of this perspective in terms of the critical turn within medical anthropology are examined.

Anthropology↗
PubMed1990

Severe anaphylactoid reaction to hydroxyethyl starch.

A case is presented of a severe anaphylactoid reaction to hydroxyethyl starch solution that occurred peri-operatively and required extended intensive management of the resultant bronchospasm and hypotension. Subsequent intradermal injection of hetastarch produced a delayed positive response, suggestive of a complement-mediated mechanism.

Aged↗
PubMed1990

Expression of two molecular forms of the complement decay-accelerating factor in the eye and lacrimal gland.

Complement is present in ocular fluids, but the molecular mechanism(s) restricting its activation to exogenous targets and not to autologous ocular cells are currently unknown. To clarify how this control is achieved, monoclonal antibody (mAb)-based techniques were used to examine the eye, the lacrimal gland, and ocular fluids for the decay-accelerating factor (DAF), a membrane regulatory protein which protects blood cells from autologous complement activation on their surfaces. Immunohistochemical staining of tissue sections revealed DAF antigen on corneal and conjunctival epithelia, corneal endothelium, trabecular meshwork, and retina, as well as on lacrimal gland acinar cells and in adjacent lumens. By flow cytometry, cultures of conjunctival epithelium exhibited the highest DAF levels and levels on corneal epithelium greater than corneal endothelium greater than conjunctival fibroblasts. Biosynthetic labeling of corneal endothelium yielded de novo DAF protein with an apparent molecular weight (Mr) of 75 kD, approximating that of blood cell DAF protein, and digestions of conjunctival epithelium with phosphatidylinositol-specific phospholipase C (PI-PLC), an enzyme which cleaves glycoinositolphospholipid membrane anchors, released approximately 70% of the ocular surface DAF protein similar to leukocyte surface DAF protein. Quantitations of DAF by radioimmunometric assay employing mAbs against two DAF epitopes revealed 325 ng/ml (n = 12), 4.8 ng/ml (n = 10), and 22.0 ng/ml (n = 8) of soluble DAF antigen in tears, aqueous humor, and vitreous humor, respectively. Western blot analyses of the tear DAF antigen revealed two DAF forms, one with an apparent Mr of 72 kD resembling membrane DAF forms in other sites, and a second with an apparent Mr of 100 kD, which is previously undescribed. Since DAF activity is essential physiologically in protecting blood cells from autologous complement attack, the identification of DAF on the ocular surface, intraocularly, in the lacrimal gland, and in tears suggests that DAF-mediated control of complement activation is also required in these locations.

Antibodies, Monoclonal↗
PubMed1989

Tumour necrosis factor in bronchopulmonary secretions of patients with adult respiratory distress syndrome.

Tumour necrosis factor (TNF) concentrations were measured in the bronchopulmonary secretions of 5 patients with the adult respiratory distress syndrome. Each patient underwent fibreoptic bronchoscopy and bronchopulmonary aspiration, and control samples were obtained in an identical manner from 24 patients who underwent bronchoscopy for other reasons (8 had tuberculosis, 6 had sarcoidosis, and 10 had haemoptysis but no abnormal findings). Aspirated fluid was assayed for the presence of TNF by use of an enzyme-linked immunosorbent assay. In the 5 patients with adult respiratory distress syndrome, TNF concentrations exceeded 500 U/ml (12.5 ng/ml), whereas in the control samples no TNF was detected.

Bronchoalveolar Lavage Fluid↗
PubMed1989

Optimisation of positive and expiratory pressure for maximal delivery of oxygen to tissues using oesophageal Doppler ultrasonography.

OBJECTIVE: To assess oesophageal Doppler ultrasonography as a convenient means of optimising positive end expiratory pressure for maximal delivery of oxygen to tissues. DESIGN: Measurements of blood flow, arterial oxygen saturation, and cardiac output by thermodilution (when available) at baseline and at 20-30 minutes after each incremental increase (2.5-5.0 cm H2O) in positive and expiratory pressure to a maximum of 20.0 cm H2O. If the cardiac output fell by more than 15% measurements were repeated after stepwise decreases in positive end expiratory pressure. No other manoeuvre such as endotracheal suction or changing ventilator settings, drug or fluid dosage, or the patient's position was performed for at least one hour before the start of the study or during it. SETTING: Intensive care unit. PARTICIPANTS: 10 Patients being mechanically ventilated for acute respiratory failure who had stable haemodynamic and blood gas values and required a fractional inspired oxygen concentration of greater than or equal to 0.45. They were assessed on a total of 11 occasions. INTERVENTIONS: Incremental increases in positive end expiratory pressure followed when indicated by stepwise decreases. END POINT: The positive end expiratory pressure providing maximal delivery of oxygen to tissues. MEASUREMENTS AND MAIN RESULTS: Arterial oxygen saturation increased with positive end expiratory pressure in all patients by an average of 6.1%. In nine of the 11 studies, however, cardiac output fell by 15% to 30% after the second increment. On the two other occasions cardiac output and oxygen delivery rose by up to 54%. Positive end expiratory pressure was decreased on seven occasions; there was considerable individual variation in the time taken for cardiac output to rise and arterial oxygen saturation to fall. In six patients good agreement was seen between the results from Doppler ultrasonography and thermodilution, the mean of the differences being -0.3% with narrow limits of agreement (-14.4% to 13.9%). CONCLUSIONS: Oesophageal Doppler ultrasonography is a rapid, safe, and reliable technique for optimising positive end expiratory pressure to obtain maximal delivery of oxygen to tissues. The results show the need to consider haemodynamic consequences when altering positive end expiratory pressure.

Acute Disease↗
PubMed1989

Multiple carpo-metacarpal dislocations.

Ten patients with closed multiple carpo-metacarpal dislocations have been reviewed. Closed manipulation was found to be successful if performed within two days of the injury. Plaster cast immobilisation supplemented by percutaneous Kirschner wire fixation is recommended to maintain the reduction, due to the unstable nature of the dislocation. Early appropriate treatment of these injuries carries a good prognosis.

Bone Wires↗
PubMed1989

The coming of age of critical medical anthropology.

This paper reviews the development over the last 15 years of a broadening critical trend in the field of medical anthropology by: (1) examining shortcomings of conventional medical anthropology that led to interest in critical alternatives; (2) examining historical and occupational factors that tend to conservatize the subdiscipline; (3) reviewing the body of literature produced thus far by its adherents; and (4) suggesting directions for future work.

Anthropology↗