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Biomedical subjects

S Henderson

Publications and source records attributed to S Henderson.

At least 181 records · Page 10Linked to original sources
PubMed1977

An assessment of hostility in a population of adolescents.

In the course of an epidemiological survey of adolescents, the Hostility and Direction of Hostility Questionnaire was administered to 6,709 persons aged 13 to 18 years, representing 89% of secondary school students in Hobart, Tasmania. Extrapunitiveness was found to decrease substantially between the ages of 15 and 17 years in both sexes. Intropunitiveness also decreased, although to a lesser extent. Girls were less extrapunitive and more intropunitive than boys over the whole age range. These findings are discussed in relation to their clinical relevance and to the understanding of psychiatric disorder in adolescents.

Acting Out↗
PubMed1977

Coping behaviour after shipwreck.

A description is given of the coping behaviour of seven men who survived a shipwreck and were not rescued until 13 days later. The principal behaviours shown by the men were attachment ideation, drive to survive, modelling, prayer and hope. Particular attention is paid to the first of these, and consideration given to its likely origins in behavioural evolution. It is proposed as a hitherto inadequately recognized coping behaviour. A follow-up examination 12 to 24 months later showed that five of the seven men available had developed substantial psychiatric disorder, while by contrast one was not only well but claimed to have been enriched by the experience. Exposure to extreme adversity or disaster may have long-term effects on mental health. Further longitudinal studies of disaster victims are necessary for the design of informed after-care.

Adaptation, Psychological↗
PubMed1977

The social network, support and neurosis. The function of attachment in adult life.

The psychological function of the social network is considered in terms of attachment theory. Social bonds are proposed as essential for obtaining a commodity commonly but unsatisfactorily referred to as support. Requirements for this complex commodity can be discerned in a wide range of contexts. Examples considered are the evolutionary origin of the social network itself, the concept of psychosocial supplies, the distribution of neurosis in Western and non-Western populations, the use of medical consultations, psychotherapy and habitual responses to adversity or disaster. In these and other contexts, it is apparent that individuals have, quite simply, a requirement for affectively positive interaction with others. Under stressful conditions this interaction is called 'support'. When support is lacking there is evidence that psychiatric and perhaps medical morbidity rates increase. For reaseach, the objective must now be to determine whether depleted primary group interaction is causally related to morbidity, or whether it is only an associated or a secondary factor in aetiology, or indeed wholly unrelated. Elucidating more precisely why people need people constitutes an important new task for social psychiatry.

Female↗
PubMed1977

Towards a method for assessing social support systems.

Man is committed by his biological and cultural evolution to a social existence. While the social environment is the source of many stressors, it may also be protective. This latter function is called 'support'. Social bonds are to be found universally, but some cultural groups have the integrity of these bonds conspicuously endangered. The application of the affective component of the social network to psychiatry promises to be useful, but cannot progress further until an instrument is developed for assessing the support available to an individual. We have gone some way towards a method for assessing the components of primary group interaction. The task now is to determine if low social support, such as is seen in Western suburban wives, some migrant groups and some women in the Middle East and Asia, is causally related to some psychiatric disorders The principal appeal of this area is that we may be tapping something very fundamental about human social organisation, something which, unlike adversity, is subject to modification.

Community Psychiatry↗
PubMedDate not supplied

Inherited canine giant axonal neuropathy.

To date, a single case of canine giant axonal neuropathy (GAN) has been recorded. The present report describes the disease in 3 more dogs from the second litter produced by the parents of the original case. Regular clinical and electrophysiological examinations were carried out on all 11 dogs of the second litter. At 14--16 months of age, 3 dogs developed slight posterior ataxia which progressed to a severe lower motor neuron disturbance involving only the hind legs. During this period, each dog began to regurgitate food as a result of megaesophagus. From 12 months of age, there was a progressive reduction in the amplitude of the evoked muscle action potential. Biopsy of the tibial fascicular nerve at 16 months of age confirmed that all 3 dogs had GAN, with numerous swollen unmyelinated fibers and less frequent enlarged myelinated fibers containing accumulated neurofilaments.

Action Potentials↗
PubMedDate not supplied

A small angle X-ray scattering study of the binding of cyclosporin-A to calmodulin.

Small angle X-ray scattering (SAXS) was applied to the binding of the immunosuppressant drug cyclosporin-A to the protein calmodulin. Guinier analysis of the SAXS profiles yielded a radius of gyration, Rg, of 19.7 +/- 0.3 A for the native protein and 16.9 +/- 0.3 A for the drug/protein complex. Maximum entropy (maxent) methods of data analysis were used to calculate the distance distribution function, p(r). From this analysis, the Rg for the native protein is 20.9 +/- 0.1 A and that for the complex 16.7 +/- 0.1 A. The measured SAXS profiles and the derived p(r) for calmodulin agree with profiles calculated from the crystallographic structure of calmodulin. Major structural changes are induced in calmodulin on binding cyclosporin-A. A model consistent with the observed scattering profiles is an ellipsoid with major axes 55 and 36 A. Molecular modeling of the calmodulin molecule suggests that bond rotation in the flexible alpha-helix linker region produces models consistent with the above observations.

Animals↗
PubMedDate not supplied

Knowledge engineering using retrospective review of data: a useful technique or merely data dredging?

The process of extracting the knowledge or rules for medical decision making is not an easy task. One approach to knowledge engineering is to carefully review how decisions were made in the past with the goal of extracting the rules. The purpose of this project was to use previously collected data from ICU patients to derive the rules for the definition of hemodynamic stability. 97 ICU patients between 9/9/86 and 7/29/90 were included in the analysis. All of these patients had adult respiratory distress syndrome. Their mechanical ventilation was managed by a set of computerized protocols. We retrospectively searched the HELP system database for instructions that were not followed due to hemodynamic reasons. For each patient, we also chose one randomly selected therapy instruction which was followed to act as a control. For each instruction we then selected the corresponding hemodynamic data set. The data was then used in a stepwise logistic regression to determine the rules used for defining hemodynamic instability. We found that several of the hemodynamic parameters we had anticipated to be important were not even measured most of the time. The blood pressures and heart rate were almost identical between the hemodynamicly stable and unstable data sets. We conclude that the decision making process used by physicians has great variation, both between and within physicians. This makes knowledge engineering using retrospective techniques such as this prone to error and probably not very fruitful.

Bias↗
PubMedDate not supplied

A strategy for development of computerized critical care decision support systems.

It is not enough to merely manage medical information. It is difficult to justify the cost of hospital information systems (HIS) or intensive care unit (ICU) patient data management systems (PDMS) on this basis alone. The real benefit of an integrated HIS or PDMS is in decision support. Although there are a variety of HIS and ICU PDMS systems available there are few that provide ICU decision support. The HELP system at the LDS Hospital is an example of a HIS which provides decision support on many different levels. In the ICU there are decision support tools for antibiotic therapy, nutritional management, and management of mechanical ventilation. Computer protocols for the management of mechanical ventilation (respiratory evaluation, ventilation, oxygenation, weaning and extubation) in patients with adult respiratory distress syndrome ((ARDS) have already been developed and clinically validated at the LDS Hospital. These protocols utilize the bedside intensive care unit (ICU) computer terminal to prompt the clinical care team with therapeutic and diagnostic suggestions. The protocols (in paper flow diagram and computerized form) have been used for over 40,000 hours in more than 125 adult respiratory distress syndrome (ARDS) patients. The protocols controlled care for 94% of the time. The remainder of the time patient care was not protocol controlled was a result of the patient being in states not covered by current protocol logic (e.g. hemodynamic instability, or transport for X-Ray studies). 52 of these ARDS patients met extra corporal membrane oxygenation (ECMO) criteria. The survival of the ECMO criteria ARDS patients was 41%, four times that expected (9%) from historical data (p less than 0.0002).(ABSTRACT TRUNCATED AT 250 WORDS)

Attitude of Health Personnel↗
PubMedDate not supplied

Performance of computerized protocols for the management of arterial oxygenation in an intensive care unit.

Computerized protocols were created to direct the management of arterial oxygenation in critically ill ICU patients and have now been applied routinely, 24 hours a day, in the care of 80 such patients. The protocols used routine clinical information to generate specific instructions for therapy. We evaluated 21,347 instructions by measuring how many were correct and how often they were followed by the clinical staff. Instructions were followed 63.9% of the time in the first 8 patients and 92.3% in the subsequent 72 patients. Instruction accuracy improved after the initial 8 patients, increasing from 71.5% of total instructions to 92.8%. Instruction inaccuracy was primarily caused by software errors and inaccurate and untimely entry of clinical data into the computer. Software errors decreased from 7.2% in the first 8 patients to 0.8% in subsequent patients, while data entry problems decreased from 7.5% to 4.2%. We also assessed compliance with the protocols in a subset of 12 patients (2637 instructions) as a function of 1) the mode of ventilatory support, 2) whether the instruction was to increase or decrease the intensity of therapy or to wait for an interval of time and 3) whether the instruction was 'correct' or 'incorrect'. The mode of ventilatory support did not affect compliance with protocol instructions. Instructions to wait were more likely to be followed than instructions to change therapy. Ninety-seven percent of the correct instructions were followed and 27% of the incorrect instructions were followed.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Gas Analysis↗
PubMedDate not supplied

Differential effects of ninaC proteins (p132 and p174) on light-activated currents and pupil mechanism in Drosophila photoreceptors.

The Drosophila ninaC locus encodes two retinal specific proteins (p132 and p174) both consisting of a protein kinase joined to a myosin head domain and a C terminal with a calmodulin-binding domain. The role of p132 and p174 was studied via whole-cell recording and through measurements of the pupil mechanism, i.e. the pigment migration in the photoreceptor cells, in the ninaC mutants, P[ninaC delta 132] (p132 absent), P[ninaC delta 174] (p174 absent), and ninaCP235 (null mutant). Voltage-clamped flash responses in P[ninaC delta 174] and ninaCP235 showed delayed response termination. In response to steady light, plateau responses in both P[ninaC delta 174] and ninaCP235 were also large. In both cases the defect was significantly more severe in ninaCP235. Responses in P[ninaC delta 132] were apparently normal. P[ninaC delta 174] and ninaCP235 were also characterized by spontaneous quantum bump-like activity in the dark and by larger and longer light-induced quantum bumps. The turn-off of the pupil mechanism in P[ninaC delta 174] and ninaCP235 was also defective, although in this case the rate of return to baseline in both mutants was more or less the same. In all ninaC mutants, the amplitudes of the pupillary pigment migration were distinctly smaller than that in the wild type. The reduction of the amplitude was largest in P[ninaC delta 174]. The light sensitivity of the pupil mechanism of P[ninaC delta 174] compared to that of wild type was reduced by 1.3 log units. Remarkably, the light sensitivity of P[ninaC delta 132] and ninaCP235 was ca. 0.5 log units higher than that of the wild type. The results suggest that the p174 protein is required for normal termination of the transduction cascade. The diverse phenotypes observed may suggest multiple roles calmodulin distribution for controlling response termination and regulating pigment migration in Drosophila photoreceptors.

Animals↗
PubMedDate not supplied

Molecular genetics and the epidemiology of common mental disorders: new opportunities.

AIM: To describe the rationale for introducing molecular genetic analyses to psychiatric epidemiology. This offers new possibilities for aetiological research on common mental disorders. METHODS: In addition to the traditional variables used in field surveys, it is now possible to include molecular genetic information. This is currently done by looking for allelic associations rather than by linkage analysis, and can be directed either at traits conferring susceptibility or at states. The purpose is to identify quantitative trait loci (QTLs) by examining candidate genes. An alternative strategy is genome scanning, which can identify genes by their chromosomal position with increasing resolution. RESULTS: Some associations have already been reported in the literature, linking personality traits with particular alleles extraversion or novelty-seeking with a polymorphism of the dopamine DRD4 receptor gene; and neuroticism with a polymorphism of the serotonin transporter gene. CONCLUSIONS: These findings are of major interest, but cannot yet be looked upon as confirmed. What is significant for epidemiology is the opportunity to link behavioural and psychiatric variables with genes influencing biochemical and physiological processes in the brain, and to do so at the population level. For further allelic association studies, there are four principal requirements: valid measures of phenotypes; replication of findings across diverse populations; more candidate genes; and exploration of the interaction between genotype and environmental exposures from conception to late life. Through such research, psychiatric epidemiology can now investigate biopsychosocial phenomena.

Humans↗