Biomedical subjects
Publications and source records attributed to M Foley.
The five freshman congressmen we're profiling in this issue have a lot more going for them than Mr. Smith did; most importantly, all bring strong community health and welfare concerns to Capitol Hill. A look at representatives of a sometimes surprising new crop of citizen-lawmakers.
In order to determine the effect of family support on the psychological well-being of heterosexual couples with at least one HIV-seropositive, family support data were obtained from couples, who were separately interviewed. Two hundred heterosexuals were interviewed (97 males, 103 females). 182 were partners in HIV serodiscordant couples (18 members were in 10 couples concordant for HIV-seropositivity). Overall, there were 76 HIV+ males and 30 HIV+ females. The Brief Symptom Inventory (BSI) was used to measure psychological distress. Sixty-five per cent of the subjects had family members aware of partners' HIV infection, but only 50% of aware families were reported as supportive. Family support was not a significant predictor of distress. Gender was the most significant predictor of psychological distress as measured by the BSI subscales. Both HIV positive and HIV negative females had more distress than their male counterparts on several dimensions (somatization, obsessive-compulsive, interpersonal sensitivity, depression, anxiety, phobic anxiety and paranoia), and on the General Severity Index (GSI) of the BSI (HIV-positives: p = 0.003; HIV-negatives: p = 0.01). Despite the general lack of association of family support with psychological distress, women in couples affected by HIV had more distress than men. The mental health needs of women clearly differ from men, and continued gender comparisons should be done to develop appropriate and effective interventions for these groups.
The world-wide incidence of Caesarean section continues to rise with dystocia recognized as the major indication. Active management of labour has been proposed as an alternative treatment to Caesarean section for dystocia. At the National Maternity Hospital, Dublin, a recent increase in the Caesarean section rate has been observed. This retrospective review reveals this to be due to other indications.
This study assesses second-year medical students' views of the nurse and compares them to those commonly held by the lay public. Using a modified version of the American Nurses Association National Commission's "Nursing Implementation Project Survey," views of the role of the registered professional nurse were elicited from second-year medical students in 1992 (n = 38), 1993 (n = 50), and 1994 (n = 70) during workshops designed for them to enhance nurse-physician collegiality. Misconceptions about the nursing profession and the scope of the nurse's role to ensure positive patient outcomes, were elucidated. Medical students welcomed opportunities within the curriculum to redefine their conceptions of the image of registered professional nurses. Nurses' advanced professional capabilities and interdisciplinary collegiality deserve continued attention throughout the medical school curriculum.
Erythrocytes infected with mature-stage malaria parasites accumulate phospholipids from exogenous sources. We show that the transport of N-(7-nitrobenzy-2-oxa-1,3-diazol-4-yl)-1,2- dipalmitoyl-sn-glycero-3-phosphatidylethanolamine (N-NBD-DPPE), from the erythrocyte membrane to the intracellular malaria parasite, is dependent upon metabolic energy. A photoreactive phospholipid analogue, N-[125I]iodo-4-azidosalicylamidyl-1, 2-dilauryl-sn-glycero-3-phosphatidylethanolamine (N-125I-ASA-DLPE), has been synthesised and used in an attempt to identify proteins involved in phospholipid trafficking in malaria-infected erythrocytes. This photoreactive probe was found to preferentially label a protein with an apparent molecular weight of 22 kDa. Photolabelling of the 22-kDa protein was enhanced upon ATP depletion of malaria-infected erythrocytes.
A cDNA clone encoding part of a novel polymorphic merozoite antigen from Plasmodium falciparum was isolated by screening a cDNA library with human immune serum from Papua New Guinea. Immunofluorescence microscopy and immunoblotting with affinity-purified antibodies recognized a highly polymorphic antigen, Ag956, present in schizonts and merozoites. Biosynthetic labeling and immunoprecipitation experiments demonstrated that Ag956 is proteolytically cleaved during merozoite maturation. The complete genomic sequence of Ag956 from the D10 clone of P. falciparum isolate FC27 encodes a secreted protein of calculated molecular mass 43,243 that is very hydrophilic and contains a region of unusual heptad repeats of the general structure AXXAXXX. This antigen has been named the secreted polymorphic antigen associated with merozoites (SPAM). The sequence of a second SPAM allele from the 3D7 clone of isolate NF54 reveals that the alanine heptad repeats and the hydrophilic C-terminal half of the protein are conserved. Variation among SPAM alleles is the result of deletions and amino acid substitutions in non-repetitive sequences within and flanking the alanine heptad-repeat domain. Heptad repeats in which the a and d position contain hydrophobic residues generate amphipathic alpha-helices which give rise to helical bundles or coiled-coil structures in proteins. Thus, SPAM is the first example of a P. falciparum antigen in which a repetitive sequence has features characteristic of a well-defined structural element.
OBJECTIVE: To ascertain the extent of family member support to heterosexual HIV-serodiscordant couples, and to identify associated sociodemographic and clinical characteristics. DESIGN: Discordant couples enrolled in a cohort study of heterosexual HIV transmission were interviewed with structured questionnaires to obtain sociodemographic data, family member awareness of HIV and perceived support from family members. Clinical characteristics were established by medical history, physical examination and laboratory tests. RESULTS: Awareness and support of family members were associated with sex of family member and HIV seropositivity, sex, education, and race of the partner. HIV-seropositive partners were more likely to have a sister aware than were HIV-negative partners (P = 0.01). More educated HIV-positive partners had fewer aware family members than less educated HIV-positive individuals (P = 0.02). Mothers of HIV-positive women were more often aware than mothers of all other partners (P = 0.04). Black HIV-negative partners had fewer aware family members than whites or Hispanics (P = 0.02). CONCLUSION: This research shows both encouraging and disturbing patterns of family awareness of HIV and support to serodiscordant partners.
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Providing efficacious, compassionate, and efficient medical care to persons with HIV infection is one of the greatest challenges that will face US hospitals this decade. Unfortunately, there have been almost no studies of how organizational arrangements are related to the quality of care. We developed an interview protocol and conducted a pilot study to evaluate the instrument's ability to detect differences in selected interpersonal aspects of care provided to persons with AIDS. We evaluated the care received in two different treatment models in a major teaching hospital: a designated AIDS unit and general medical beds. We assessed several areas of patient care that are clinically important and that patients can evaluate: communication between patients and providers, patient education, respect for patient preferences, emotional support, involvement of family and friends, trust and confidence, physical care, pain management, AIDS knowledge, perceived segregation, confidentiality, and financial information. Patients generally were very satisfied with their hospital care, but many reported problems with certain aspects of their care. The instrument used detected differences between the care reported by patients treated in general hospital beds and in a designated AIDS unit in several specific aspects of care.
The approach of term in the pregnancy of a diabetic woman is a time of anxiety for patient and physician alike. The impact of a conservative approach to the timing of delivery is outlined in this review of the clinical course and outcome of 276 pregnancies of diabetic women, delivered at the National Maternity Hospital, Dublin between 1981 and 1990. The mean gestation at delivery was 39 weeks, 229 patients (83%) delivered at or beyond 38 weeks and 112 patients (41%) delivered at or beyond 40 weeks. The overall induction of labour rate was 27% and the elective Caesarean section rate was 19%. Sixty seven percent of patients achieved a normal delivery, the forceps rate was 5%, and 28% of patients were delivered by Caesarean section. There were 16 perinatal deaths in the series, with 7 due to lethal malformations. There were 5 deaths of normally formed infants occurring at or beyond 38 weeks' gestation. All of these 5 deaths had been preceded by clinically apparent polyhydramnios or macrosomia and recognized poor control. This study stresses the value of strict diabetic control in the management of diabetic pregnancy and highlights the significance of polyhydramnios and macrosomia as indicators of risk approaching term in diabetic pregnancy.
The effects of diets differing in saturated, monounsaturated and polyunsaturated fatty acid composition (SAFA, MUFA and PUFA, respectively) on plasma lipoproteins and factor VIIc were investigated in 28 middle-aged men and women with mild to moderate hyperlipidaemia. The subjects were stabilized on a diet with a total fat content fairly typical of New Zealand, containing approximately 40% energy as fat, before entering a randomized cross-over trial of diets high in PUFA (20% energy; SAFA and MUFA 10% each) or a high MUFA diet (20% energy; SAFA and PUFA 10% each). After 6-week periods on each diet the subjects returned to a high SAFA diet. Body weight and blood pressure remained unchanged during the study. Total and LDL cholesterol, HDL cholesterol and the HDL2 subfraction were significantly lower on both the MUFA and the PUFA diet than on SAFA. However, there were no statistically significant differences in lipoprotein concentrations on the MUFA and PUFA diet. Factor VIIc concentrations were similar on the three diets. The proportion of PUFA in a MUFA diet appears to be a major determinant of the relative lipoprotein response to such a diet. In order to avoid a reduction in HDL-C when replacing SAFA with MUFA it may be necessary to ensure that PUFA does not provide more than about 8% total energy. Thus careful planning is needed to identify the most appropriate foods to replace those rich in SAFA in diets designed to reduce the lipoprotein-mediated risk of coronary heart disease.
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The malaria parasite Plasmodium falciparum synthesises a protein, RESA, which associates with the membrane of newly invaded erythrocytes. Using spent supernatants from P. falciparum growing in culture as a source of soluble RESA we have developed an assay to examine the characteristics of RESA binding to the erythrocyte membrane in vitro. RESA associated with the Triton X-100 insoluble proteins on the inner face of the host erythrocyte membrane but did not bind to the outer surface of intact erythrocytes. Other proteins present in culture supernatants did not bind to the erythrocyte membrane. RESA was co-sedimented with the ternary complex formed between actin, spectrin and band 4.1 and co-precipitated with spectrin precipitated with anti-spectrin antibodies. The extent of association between RESA and the inner face of the erythrocyte membrane was reduced by the inclusion of excess purified spectrin in the assay. Thus, RESA appears to be associated with spectrin in the erythrocyte membrane skeleton.
This study reevaluated the link between the rate of CO2 flow to the pulmonary circulation and changes in cardiac output to the respiratory responses following leg lifting in normal man subjects. Thirty healthy subjects (mean age = 22.2 years) were subjected to the experimental maneuver which increased venous return to the right heart. Cardiac output was significantly increased and with it a significant increase in CO2 output by the lungs was found. These results were associated with a significant increase in expired ventilation. The rapidity of the ventilatory response to the increase in cardiac output suggests the existence of pressoreceptors localized in the pulmonary circulation which, when activated, results in the elicitation of respiratory reflexes. The end result is an adjustment in the respiratory response in accordance with venous return.
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Time-resolved phosphorescence anisotropy was used to study the molecular organisation of band 3 in the erythrocyte membrane. Three different rotational relaxation regimes of mobile band 3 were resolved. These populations may represent different aggregation states of band 3 within the membrane, or they may result from association of band 3 with other proteins at the cytoplasmic surface. The polycation spermine decreases the apparent mobility of band 3 by a mechanism that does not involve the underlying cytoskeleton. A monoclonal antibody directed against the cytoplasmic portion of band 3 can also cause an increase in the immobile fraction of band 3 molecules. This monoclonal antibody will inhibit invasion of erythrocytes by malaria parasites. Membranes prepared from erythrocytes infected with mature stages of the malaria parasite, Plasmodium falciparum, show altered dynamic properties corresponding to a marked restriction of band 3 mobility.
The ring-infected erythrocyte surface antigen (RESA) is a 155-kDa malarial polypeptide which is released from merozoites and becomes associated with the erythrocyte membrane at the time of invasion. Inside-out vesicles (IOVs) prepared from Plasmodium falciparum-infected erythrocytes contain RESA, presumably bound to the membrane skeleton, as it is largely insoluble in Triton X-100. When these IOVs were incubated with [gamma-32P]ATP, a 155-kDa polypeptide was labeled in IOVs from infected, but not from uninfected erythrocytes. Immunoprecipitation using specific rabbit antisera confirmed that RESA is indeed a phosphoprotein. Phosphoamino acid analysis revealed phosphoserine and a small amount of phosphothreonine, but no phosphotyrosine. Labeling of intact parasitized erythrocytes with inorganic [32P]phosphate for several hours in culture resulted in RESA in Triton-insoluble extracts being phosphorylated. Labeling of synchronized parasites showed that RESA was phosphorylated only when it became associated with the erythrocyte membrane, and although RESA was abundant in mature parasites, it was not phosphorylated. RESA, released into the culture supernatants during the growth of P. falciparum, bound to IOVs prepared from normal uninfected erythrocytes, and subsequent labeling with [gamma-32P]ATP resulted in the phosphorylation of RESA. The evidence suggests that RESA is phosphorylated by an erythrocyte membrane kinase and probably not by a parasite-encoded enzyme.
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