PubMed Health⌕ Search

Biomedical subjects

A Palmer

Publications and source records attributed to A Palmer.

At least 73 records · Page 4Linked to original sources
PubMed1997

Drug use and its relationship to other behavior disorders and maladjustment signs among adolescents.

Based on a representative sample of 1,312 students 13 to 19 years of age from Mallorca, Spain, we used 19 variables from an anonymous questionnaire to define three groups of problems frequently found in adolescents: depression, deviant behaviors, and the use of alcohol, tobacco, and illicit drugs. We have found a close relationship between drug use and deviant behaviors which shows no relationship with depressive symptoms. There is a small group which uses drugs with no relationship to deviant behaviors. There are also relationships between these problem behaviors and sleeping difficulties, enuresis, weight problems, family difficulties, etc., which leads us to think of a network of connections with other problems of the adolescent and his family.

Adolescent↗
PubMed1997

Predictors of a fatal outcome following childhood cerebral malaria.

Despite prompt treatment with an effective anti-malarial drug, cerebral malaria still has a mortality of 20-30%. To identify factors that may contribute to this high fatality rate, we have studied the relationship between clinical and laboratory features and a fatal outcome in 624 Gambian children with strictly defined cerebral malaria. One hundred twenty-four children (21.5%) died. Three-quarters of the deaths occurred within 24 hr of admission. Multiple logistic regression analysis showed that a cold periphery (odds ratio [OR] = 2.7), a deep coma (OR = 2.0), and hypoglycemia (OR = 4.1) were the clinical signs and laboratory parameters that predicted death most strongly. More than 90% of the children who died had at least one of these conditions. Also, children with elevated urea levels on admission or those who experienced multiple episodes of hypoglycemia or multiple convulsions subsequently were more likely to die. A combination of clinical and laboratory abnormalities can identify a group of children with cerebral malaria who are most at risk of dying, who require intensive care and who are candidates for new forms of therapy.

Age Factors↗
PubMed1997

Moving from hospital into a care home--the nurse's role in supporting older people.

Discharge planning has received much attention in the nursing literature over the past few years, and there has been particular concern over the discharge of older people back into their domestic environment. The practical and logistical problems of managing such a discharge are considerable, but in this paper we argue that discharging older people from hospital to care homes is equally problematic, though in different ways. This is a neglected area of research, perhaps because discharge into a care home seems to present fewer organizational problems. There is, however, an extensive body of literature from a range of different disciplines which suggests that the loss of home and entry into a strange environment can be very stressful. This paper outlines this literature and explores the implications for nursing practice.

Aged↗
PubMed1997

Pallor as a clinical sign of severe anaemia in children: an investigation in the Gambia.

Anaemia associated with malaria is a major public health problem in African countries. Since most primary health facilities have to rely on physical signs and not laboratory tests to detect anaemic patients who need referral for blood transfusion, we have assessed the reliability of simple clinical signs to predict severe anaemia. A trained field assistant examined 368 children admitted to a tertiary care hospital, assessing the pallor of their eyelids (conjunctiva), palms and nailbeds, counting the respiratory rate, and looking for signs of respiratory distress. After the children's admission, their packed cell volume (PCV) was measured, and the need for transfusion and the outcomes were noted. A second observer examined 173 of these children so that interobserver variability in the detection of clinical signs could be assessed. A total of 27% of the 368 children had a PCV of < 15%. In a multiple regression analysis, definite pallor of the conjunctiva, definite pallor of the palms, and a "sick" appearance of the child were identified as independent significant predictors of a PCV of < 15%. The best predictor was a combination of definite pallor of the conjunctiva and pallor of the palms, with a sensitivity of 80% and a specificity of 85%. Inclusion of signs of respiratory distress did not improve the prediction. Pallor was a reproducible sign (weighted kappa statistic for the comparison between two observers: kappa = 0.6 for conjunctival pallor). We conclude that pallor can be used as a sign for referring children who may require blood transfusion.

Anemia↗
PubMed1996

A trial of artemether or quinine in children with cerebral malaria.

BACKGROUND: Cerebral malaria has a mortality rate of 10 to 30 percent despite treatment with parenteral quinine, a situation that may worsen with the spread of quinine resistance. Artemether is a new antimalarial agent that clears parasites from the circulation more rapidly than quinine, but its effect on mortality is unclear. METHODS: We conducted a randomized, unblinded comparison of intramuscular artemether and intramuscular quinine in 576 Gambian children with cerebral malaria. The primary end points of the study were mortality and residual neurologic sequelae. RESULTS: Fifty-nine of the 288 children treated with artemether died in the hospital (20.5 percent), as compared with 62 of the 288 treated with quinine (21.5 percent). Among the 418 children analyzed at approximately five months for neurologic disease, residual neurologic sequelae were detected in 7 of 209 survivors treated with artemether (3.3 percent) and 11 of 209 survivors treated with quinine (5.3 percent, P = 0.5). After adjustment for potential confounders, the odds ratio for death was 0.84 (95 percent confidence interval, 0.53 to 1.32) in the artemether group, and for residual neurologic sequelae, 0.51 (95 percent confidence interval, 0.17 to 1.47). There were fewer local reactions at the injection site with artemether than with quinine (0.7 percent vs. 5.9 percent, P = 0.001). CONCLUSIONS: Artemether is as effective as quinine in the treatment of cerebral malaria in children.

Antimalarials↗
PubMed1996

Subpopulations of proteasomes in rat liver nuclei, microsomes and cytosol.

Mammalian proteasomes are composed of 14-17 different types of subunits, some of which, including major-histocompatibility-complex-encoded subunits LMP2 and LMP7, are non-essential and present in variable amounts. We have investigated the distribution of total proteasomes and some individual subunits in rat liver by quantitative immunoblot analysis of purified subcellular fractions (nuclei, mitochondria, microsomes and cytosol). Proteasomes were mainly found in the cytosol but were also present in the purified nuclear and microsomal fractions. In the nuclei, proteasomes were soluble or loosely attached to the chromatin, since they could be easily extracted by treatment with nucleases or high concentrations of salt. In the microsomes, proteasomes were on the outside of the membranes. Further subfractionation of the microsomes showed that the proteasomes in this fraction were associated with the smooth endoplasmic reticulum and with the cis-Golgi but were practically absent from the rough endoplasmic reticulum. Using monospecific antibodies for some proteasomal subunits (C8, C9, LMP2 and Z), the composition of proteasomes in nuclei, microsomes and cytosol was investigated. Although there appear not to be differences in proteasome composition in the alpha subunits (C8 and C9) in the different locations, the relative amounts of some beta subunits varied. Subunit Z was enriched in nuclear proteasomes but low in microsome-associated proteasomes, whereas LMP2, which was relatively low in nuclei, showed a small enrichment in the microsomes. These differences in subunit composition of proteasomes probably reflect differences in the function of proteasomes in distinct cell compartments.

Animals↗
PubMed1996

Humidification of oxygen with unheated humidifiers in tropical climates.

In developing countries, oxygen therapy in hospitals is frequently humidified with unheated bubble-through humidifiers. We assessed the efficacy of humidification under such circumstances. The water temperature in the humidifier and the ambient air temperature were measured and compared to the oxygen flow rate. It was calculated that oxygen was cooled in the humidifier by 6.12 degrees C (95% CI: 5.88; 6.35) per liter of flow for flow rates up to 2 l/min. Using the average temperatures on the hospital ward in January and August, and the WHO-recommended flow rates of 0.5 l/min and 1 l/min, the relative humidity of the oxygen delivered to a child was estimated to be between 34% and 56%. We conclude that unheated bubble-through humidifiers achieve low humidity in oxygen in tropical climates. Some of the complications associated with the use of nasopharyngeal catheters for the delivery of oxygen might be explained by this, as oxygen of low humidity and temperature is delivered directly into the posterior nasopharynx.

Acute Disease↗
PubMed1996

Haemophilus influenzae type b disease in the western region of The Gambia: background surveillance for a vaccine efficacy trial.

In preparation for a field trial of an Haemophilus influenzae type b conjugate vaccine in the Western Region of The Gambia, a 3-year prospective study was undertaken to determine the incidence of Hib disease and the vaccination status of affected children. One hundred and eighty-two children with invasive Hib disease were found; 141 (77%) had meningitis, 31 (17%) pneumonia and 10 (6%) other forms of invasive disease. The estimated annual incidence rates for all invasive Hib diseases were 274 and 73 per 100,000 in children aged < 1 and < 5 years, respectively. For meningitis, the rate was 222 per 100,000 per year in children aged < 1 year. Children with meningitis were significantly younger than those with pneumonia (median age 7 months, interquartile range [IQR] 5-9, vs 12 months, IQR 6-15 (P = 0.002)) and younger than those with other forms of Hib disease. Of 142 children for whom vaccination status was known, 18 had received no DPT, 36 had received one, 40 had received two and 48 had received three doses. This study confirmed the high incidence of systemic Hib disease among Gambian children and the need to vaccinate at an early age. It provided the background epidemiological data required for the successful planning of an Hib vaccine trial which is now in progress.

Age Distribution↗
PubMed1996

The effect of a monoclonal antibody to tumor necrosis factor on survival from childhood cerebral malaria.

Tumor necrosis factor (TNF) is thought to play a key role in the pathogenesis of cerebral malaria. A double-blind, placebo-controlled trial of an anti-TNF monoclonal antibody (B-C7) comprised 610 Gambian children with cerebral malaria, with mortality and residual neurologic sequelae as primary study end points. Sixty (19.9%) of 302 children who received B-C7 died compared with 64 (20.8%) of 308 children who received placebo (adjusted odds ratio [OR], 0.90; 95% confidence interval [CI], 0.57-1.42). Residual neurologic sequelae were detected in 15 (6.8%) of 221 survivors from the B-C7 group and in 5 (2.2%) of 225 survivors of the placebo group (adjusted OR, 3.35; 95% CI, 1.08-10.4). The monoclonal antibody used in this study did not improve survival in cerebral malaria and was associated with a significant increase in neurologic sequelae. A possible explanation of the latter observation is that the antibody acts to retain TNF within the circulation and thereby prolongs its effects on vascular endothelium.

Antibodies, Monoclonal↗
PubMed1995

Inhibition of the pig to human xenograft reaction, using soluble Gal alpha 1-3Gal and Gal alpha 1-3Gal beta 1-4GlcNAc.

Natural anti-carbohydrate antibodies are central to hyperacute rejection in ABO-incompatible allotransplantation and in discordant xenotransplantation. ABO-incompatible rejection has been inhibited successfully using intravenous soluble carbohydrates as antibody inhibitors. The approach has been less successful previously in pig to primate xenotransplantation, where the necessary concentrations of a partial inhibitor (Gal alpha 1-6Glc) proved highly toxic. In this study, we have identified more effective inhibitors of the dominant human anti-pig antibodies that bind to the pentasaccharide Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-. The inhibitors are the terminal disaccharide (Gal alpha 1-3Gal) and terminal trisaccharide (Gal alpha 1-3Gal beta 1-4GlcNAc) of the target pentasaccharide. Twelve sera (3 from each ABO blood group) were tested in 3 different assays: lymphocytotoxic, lymphocyte flow cytometry, and solid-phase antigen ELISA. Fifty percent to 75% inhibition of human IgG and IgM was achieved using the disaccharide and trisaccharide inhibitors in the range of 10-50 mM. Disaccharide (70 mM) was used to inhibit hyperacute thrombosis in pig kidneys perfused for 40 min with heparinized human AB whole blood. The disaccharide completely inhibited red cell occlusion of glomerular but not of intertubular capillaries, although there was residual platelet thrombus in glomeruli. Disaccharide and trisaccharide can, therefore, be used in concentrations shown for other carbohydrate inhibitors to be nontoxic, for inhibition of hyperacute pig-to-human xenograft rejection. The inhibition is incomplete, however, and other antigen specificities and other rejection mechanisms are likely to be involved.

ABO Blood-Group System↗
PubMed1995

Degradation of proteasomes by lysosomes in rat liver.

Proteasomes are high-molecular-mass multisubunit complexes which are believed, either by themselves or as a part of the 26S proteinase complex, to play a central role in extralysosomal pathways of intracellular protein breakdown. We have addressed the degradation of proteasomes in rat liver, investigating the possible role of lysosomes. Affinity-purified antibodies against rat liver proteasomes were used for immunoblot analysis of isolated lysosomes. Although proteasomes are not found in lysosomes from normally fed rats, they were found to accumulate in lysosomes of rats treated with leupeptin (an inhibitor of lysosomal proteases) and could also be detected in lysosomes isolated from livers of starved (24 h) rats. Proteinase-K treatment of these fractions, as well as immunogold procedures, show that a proportion of the proteasomes are inside lysosomes. Comparison of the amount of proteasomes found in lysosomes by immunoblotting with their experimentally determined half life (8.3 days) is consistent with an important role of these organelles in the degradation of rat liver proteasomes. Nevertheless, these data do not exclude the possibility that some nonlysosomal degradation of proteasome components also occurs. Since proteasomes were localized in autophagic vacuoles, it is likely that they are taken up mainly by nonselective autophagy. However, using an in vitro system, it was found that, under conditions of starvation, proteasomes may also be taken up into lysosomes and degraded via the heat-shock cognate protein of 73 kDa (hsc73)-mediated transport.

Animals↗
PubMed1995

Homology modeling of histidine-containing phosphocarrier protein and eosinophil-derived neurotoxin: construction of models and comparison with experiment.

Homology modeling methods have been used to construct models of two proteins--the histidine-containing phosphocarrier protein (HPr) from Mycoplasma capricolum and human eosinophil-derived neurotoxin (EDN). Comparison of the models with the subsequently determined X-ray crystal structures indicates that the core regions of both proteins are reasonably well reproduced, although the template structures are closer to the X-ray structures in these regions--possible enhancements are discussed. The conformations of most of the side chains in the core of HPr are well reproduced in the modeled structure. As expected, the conformations of surface side chains in this protein differ significantly from the X-ray structure. The loop regions of EDN were incorrectly modeled--reasons for this and possible enhancements are discussed.

Algorithms↗
PubMed1995

Magnetic resonance angiography of renal artery stenosis.

Renal artery stenosis is a common cause of renal impairment which in many cases may be potentially reversible. The diagnosis and follow-up of this condition is commonly carried out using the relatively invasive technique of intra-arterial angiography. Magnetic resonance angiography (MRA) is emerging as a possible alternative technique to conventional angiography. We have studied 60 patients who were referred for investigation of possible renal artery stenosis using both 3-D phase contrast MRA techniques and conventional digital arteriography. Studies were assessed prospectively and conventional angiography was assumed to be the gold standard for the purposes of this study. Calculated sensitivity and specificity results were 84% and 91% respectively, for 3-D phase contrast MRA of the renal arteries. We conclude that 3-D phase contrast MRA is a very promising technique for the noninvasive investigation of renal artery stenosis with high sensitivity and specificity levels acting as a screening test in the future for patients with this potential diagnosis, diminishing the amount of conventional angiograms that are performed.

Adult↗
PubMed1995

Comparison of nasal prongs and nasopharyngeal catheter for the delivery of oxygen in children with hypoxemia because of a lower respiratory tract infection.

OBJECTIVE: To determine the best method of oxygen delivery for children in developing countries who have hypoxemia caused by acute lower respiratory tract infection. METHODS: One hundred eighteen children between 7 days and 5 years of age with a lower respiratory tract infection and arterial hemoglobin oxygen saturation (Sao2) less than 90% were randomly selected to receive oxygen by nasopharyngeal (NP) catheter (n = 56) or nasal prongs (n = 62). A crossover study to determine the flow rate necessary to achieve an Sao2 of 95% was performed in 60 children. RESULTS: One hundred twelve children could be oxygenated by the allocated method; in six oxygenation was poor with either method. The mean duration of therapy was 87.5 hours for the prongs and 94.9 hours for the NP catheter (not significant). The median oxygen consumption was 2142 L for prongs and 1692 L for the NP catheter (not significant). In the crossover study the prongs needed, on average, 26% higher oxygen flow rates than the NP catheter to obtain an Sao2 of 95% (p = 0.003). Complete nasal obstruction was observed in 24 of the children (44%) in the NP catheter group and in 8 (13%) in the prongs group (p < 0.001). Eighteen children died, 11 with NP catheter and 7 with prongs (not significant). CONCLUSIONS: Because nasal prongs are less prone to complications, and oxygenation in children is equally effective, they are a more appropriate method than the NP catheter for oxygen delivery to children in developing countries with acute lower respiratory tract infections.

Catheterization, Peripheral↗