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Biomedical subjects

A Burton

Publications and source records attributed to A Burton.

At least 19 recordsLinked to original sources

Role of autobiographical memory in social problem solving and depression.

Depressed patients frequently exhibit deficiencies in social problem solving (SPS). A possible cause of this deficit is an impairment in patients' ability to retrieve specific autobiographical memories. A clinically depressed group and a hospital control group performed the Means-End Problem-Solving (MEPS; J. J. Platt & G. Spivack, 1975a) task, during which they were required to attend to the memories retrieved during solution generation. Memories were categorized according to whether they were specific, categoric, or extended and whether the valence of the memories was positive or negative. Results support the general hypothesis that SPS skill is a function of autobiographical memory retrieval as measured by a cuing task and by the types of memories retrieved during the MEPS. However, the dysfunctional nature of categoric memories in SPS, rather than the importance of specific memories, was highlighted in the depressed group. Valence proved to be an unimportant variable in SPS ability. The cyclical links among autobiographical memory retrieval, SPS skills, and depression are discussed.

Adaptation, Psychological

Hantavirus serologies in patients hospitalized with community-acquired pneumonia.

In many patients, the etiology of community-acquired pneumonia is not known but may be caused by previously undescribed pathogens in some cases. The recently identified hantavirus Sin Nombre (SN) causes hantavirus pulmonary syndrome. Because sporadic cases have occurred outside the range of its reservoir (the deer mouse Peromyscus maniculatus), an investigation sought to determine whether hantaviruses contributed to cases of community-acquired pneumonia in a large Baltimore hospital. Acute-phase sera from 385 hospitalized patients with pneumonia were examined using an IgG ELISA technique with antigens prepared from several hantaviruses: prototype Hantaan (HTN), Seoul (SEO), Puumala (PUU), Convict Creek (HN107), and SN. Of 385 sera, 8 (2.1%) showed some reactivity with one or more HTN, SEO, or PUU antigens but none had detectable specific IgM antibodies. No sera were reactive with SN or HN107 antigens. Thus, hantaviruses are an uncommon cause of community-acquired pneumonia in the Baltimore area.

Adult

Community-acquired pneumonia: impact of immune status.

This cross-sectional and prospective one year study evaluated adults admitted to an inner city hospital with community-acquired pneumonia. The study used extensive diagnostic methods to evaluate the etiologies of community-acquired pneumonia in hospitalized patients with differing immunologic status. Of 385 study patients, concurrent problems associated with immunosuppression were noted in 221 (57%) patients, 180 of whom were human immunodeficiency virus (HIV)-infected. The five most common causes of community-acquired pneumonia were: Streptococcus pneumoniae, Pneumocystis carinii, aspiration, Hemophilus influenzae, and gram-negative bacilli. Only 8.3% of patients had either Legionella, Chlamydia pneumoniae or Mycoplasma pneumoniae. Despite use of state-of-the-art diagnostic techniques, no diagnosis was made in 46 of 180 (25.6%) HIV-infected patients, 56 of 164 (34.1%) immunocompetent patients, and 20 of 41 (48.8%) non-HIV-infected immunosuppressed patients. The diagnostic yield of pre-antibiotic sputum culture for conventional bacteria was 99/155 (63.9%) compared to 52 of 169 patients (32.7%) with adequate post-antibiotic sputum culture (p < 0.0001). Although S. pneumonia continues to be the most commonly identified etiologic agent of community-acquired pneumonia, it is surpassed by P. carinii in the HIV-infected patient population. The apparent decline in the frequency of S. pneumoniae in our series presumably reflects administration of antibiotics prior to procurement of sputum culture. The paucity of atypical agents in this study support the current American Thoracic Society guidelines for selective use of macrolide therapy in immunocompetent adults hospitalized with community-acquired pneumonia.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Opportunistic Infections

The effects of two matched memory tasks on concurrent finger tapping.

In a dual task experiment, subjects were instructed to perform a single finger tapping task whilst either, concurrently memorizing words appearing randomly on a screen in front of them, or concurrently memorizing the positions of the words. Analysis of percentage change scores revealed a significant tapping hand by task interaction; subjects showed a significantly larger left- than right-hand decrement when the task required memorizing the positions of the words and a non-significantly larger right- than left-hand decrement when the task required memorizing the words. These results suggest that the nature of the task demands determined the pattern of interference observed.

Attention

The global HIV pandemic.

The paper reviews the distribution, transmission patterns, and likely impacts of the HIV pandemic at the beginning of 1993. As of early 1993, a cumulative total of 611,589 cases of AIDS were reported to the World Health Organization (WHO); however, because of less than complete diagnosis and reporting, the WHO estimates that a total of 2.5 million cases of AIDS had actually occurred. As of early 1993, the WHO estimates that there have been approximately 13 million infections, of which about 1 million have been in children. By the year 2000 the WHO predicts that there will be 30-40 million cumulative infections in the world, of which 90% will be in developing countries and almost half will be among women. The epidemic of HIV infection in the decade of the 1980s will result in an epidemic of AIDS in the 1990s, which will place great social and economic strains on many countries, particularly those in many areas of the developing world.

Acquired Immunodeficiency Syndrome

Interhemisphere transfer in males and females.

Sex differences in the speed of interhemisphere transfer of visual information were assessed by means of a modified version of a task on which Potter and Graves (1988) have recently reported significantly lower error rates in females. The main aim was to examine the effect of including a control condition in which stimuli are presented centrally. In the light of their results, it was predicted that any advantage to females would be restricted to the peripheral condition since central presentations do not necessarily require interhemisphere transfer. Response latencies and errors were measured. No interaction between sex and position of presentation was found to occur. It is suggested that the lower error rates observed by Potter and Graves in females may have been the result of sex differences in speed-error trade off rather than in interhemisphere transfer.

Adolescent

Hemisphere priming through practice in a musical chords task.

In a study of selective hemisphere activation, the performance of 30 subjects given either a "local" or "global" priming activity before and after a monoaurally presented chord analysis task was compared with an unprimed control group. The hypothesis was that ear advantage scores on the chords task would show increased left hemisphere involvement following local priming and increased right hemisphere involvement following global priming. The results failed to support this hypothesis. All subjects, however, regardless of priming condition, showed a very strong practice effect represented by a shift from a weak initial left ear (right hemisphere) advantage towards a significant right ear (left hemisphere) advantage (P less than 0.00006). The findings suggest that although the local/global priming activity did not lead to selective hemisphere activation, repeated exposure to the chords task resulted in increased use of analytic left hemisphere processing strategies as subjects became familiar with its processing requirements.

Adolescent

Attitudes toward smoking in 7- to 9-year-old children.

This study reports the results of a survey on smoking of 214 children aged 7 to 9 years and 182 children aged 15 to 17 years. It was found that 27.1% of the younger group and 79.5% of the older group had tried to smoke a cigarette (even if just a few puffs). The frequency of continued smoking, as expected, was much greater for the older group, with 55.1% of older smokers compared to 0.9% of younger smokers having puffed during the last 4 weeks. The attitudes of subjects to smoking were generally negative although smokers' attitudes were more positive. The effects of parental smoking habits and attitudes on the subject's decision to smoke were considered and seen to be significant. The need for a health education program aimed at the young who have not established a smoking pattern is suggested.

Adolescent

Mode of processing and hemisphere differences in the judgement of musical stimuli.

The relationship between processing strategy and ear asymmetry was examined in two experiments in which subjects were required to make judgements about monoaurally presented musical chords. In the first experiment, subjects without musical training showed a significant left ear advantage while in those with musical training a significant shift towards a right ear advantage was observed. Performance on the Embedded Figures Test (EFT) suggested a strong relationship between analytic processing style and right ear advantage which was significant in the musician groups. The effect of musical training status on ear asymmetry continued to be significant when the scores were adjusted for analytic processing. There was also a clear relationship between self-reported listening strategies and direction of ear asymmetry, with musicians generally reporting a much greater use of analytic strategies. The second experiment failed to demonstrate a significant influence of explicit instructions in how to carry out a chords task on the direction of ear advantages in musically untrained subjects. The results partially confirm earlier studies comparing subjects with and without musical training, and extend them by demonstrating a clear relationship between ear advantage and a separate measure of processing strategy. The findings of the second experiment, however, do not support clearly the hypothesis that differences in ear asymmetry are produced through the use of different processing strategies.

Adolescent

Stimulation by 17 alpha-hydroxyprogesterone of glycoprotein and glycosaminoglycan synthesis in human placenta in vitro.

The incorporation of 14C-glucosamine into glycoproteins (GP) and glycosaminoglycans (GAG), of 3H-leucine into protein, and the hexuronic acid (HA) content of polymerized GAG was determined in incubated placental tissue. In placentae of earlier gestational age (GA), incorporation of 14C-glucosamine was 2.6 times greater than other at 38-39 weeks GA. 19 of 26 placentae at 38-39 weeks GA responded by one or more parameters when incubated with 0.5-3 microM 17 alpha-OH-progesterone (17OHP). Those which did not respond were all of earlier GA; the placental content of GAG decreased in these from 31.1 +/- 1.8 nmol HA/mg protein to 16.4 +/- 1.5 nmol in placentae of GA 38-39 weeks. In the latter, 17OHP increased GAG by 42.5% to 24.4 +/- 2.5 nmol HA/mg protein in a 2-hour incubation. Progesterone, oestriol, cortisol and testosterone were without effect. It is concluded that synthesis of placental GAG decreases toward the end of gestation, but can be increased by 17OHP specifically. This indicates that 17OHP is a biologically active steroid and might have a role in maintaining placental function.

17-alpha-Hydroxyprogesterone