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Biomedical subjects

J M Clark

Publications and source records attributed to J M Clark.

At least 127 records · Page 7Linked to original sources
PubMed1993

Nurse managers' perceptions of contracting for nurse education, Part 2: Contracting and post-registration education.

The introduction of the 'purchaser/provider' split into nurse education alters the relationship between service units (or the education purchasers) and colleges of health studies (the education providers). This is the second of two papers, and focuses on senior health service managers views on the purchasing and provision of post-registration nurse education. 24 managers from one region were interviewed. The aim was to identify their post-registration education needs, the criteria they use to choose between post-registration courses held in different colleges, and how they identify 'value for money' in post-registration education. The findings showed a limited understanding of the financial issues involved and considerable variation in opinion regarding the purpose, type and academic level of post-registration education. Cost emerged as a potentially more influential factor than quality in determining which courses managers will purchase. The managers interviewed are predominantly looking to contract with colleges who will be communicative, receptive to their needs, and willing to work in partnership with them.

Attitude of Health Personnel↗
PubMed1993

Nurses' experiences of caring for ethnic-minority clients.

This paper describes a research study designed to explore the experiences of nurses caring for ethnic-minority clients and to identify any specific problems nurses encounter when caring for these clients. Data were collected through a process of in-depth interviews with 18 trained nurses. The findings of the study suggest that nurses caring for ethnic-minority clients share many common experiences, problems and challenges. Difficulties in communication with clients and a lack of knowledge about cultural differences were highlighted by all respondents. The lack of holistic care and the inability to develop a therapeutic relationship were identified as major areas of frustration and stress. The study demonstrates that there is an urgent need to develop cultural knowledge in nurse education programmes and that nurses need help and support with communication difficulties. Interpreting services and dietary facilities available for ethnic-minority clients were also found to be inadequate and it is suggested that there is a need to review these facilities within hospitals.

Attitude of Health Personnel↗
PubMed1993

Survey of the Anopheles maculatus complex (Diptera: Culicidae) in peninsular Malaysia by analysis of cuticular lipids.

Anopheles maculatus Theobald sensu lato is a species complex now consisting of eight sibling species; An. maculatus is still represented by two cytologically distinct forms; i.e., the widely distributed sensu strictu or B, and E from southern Thailand and adjacent areas in northern Malaysia. Cuticular lipid profiles in conjunction with principal component analysis was used to separate An. maculatus form E from sensu stricto form B in a preliminary survey of the An. maculatus complex at five locations spanning peninsular Malaysia. The relative rank orders, from the areas of the five gas chromatographic peaks used to determine lipid differences for specimens from peninsular Malaysia, matched well with those from cytogenetically identified colony specimens of An. maculatus forms B and E. The two-dimensional principal component pattern of specimens identified as form E was highly clumped, which indicated that very similar cuticular lipids were present within this putative malaria vector. Both forms coexisted in peninsular Malaysia, but form E may be dominant except in the south.

Animals↗
PubMed1992

N-methyl-D-aspartate lesions of the lateral hypothalamus do not reduce amphetamine or fenfluramine anorexia but enhance the acquisition of eating in response to tail pinch in the rat.

These experiments examine the acquisition of tail pinch-induced eating and responses to the anorectic agents d-amphetamine and d,l-fenfluramine by rats bearing N-methyl-D-aspartate (NMDA) lesions of the lateral hypothalamus. Lesioned rats lost weight following surgery but had no significant eating or drinking difficulties in the home cage (Clark et al. 1990). The acquisition of eating in response to tail pinch was enhanced in lateral hypothalamic-lesioned rats: they ate on earlier test sessions than controls and less pressure was required to elicit eating. Home cage food intake over the period when tail pinch was being examined was not affected by the lateral hypothalamic lesions. There were no significant differences between lateral hypothalamic-lesioned and control rats in terms of their anorectic responses to either d-amphetamine or d,l-fenfluramine, though the lesioned rats had a lower baseline intake. These data suggest that the lateral hypothalamus is not an important site for the mediation of amphetamine or fenfluramine anorexia but is involved in the acquisition of tail pinch-induced eating. The disinhibition of responding to tail pinch by lateral hypothalamic lesions is discussed in terms of the possible role the lateral hypothalamus plays in regulating cortical activity. The role of the medial hypothalamus and non-hypothalamic systems in the response to anorectic drugs and tail pinch is discussed.

Amphetamine↗
PubMed1992

NMDA lesions of lateral hypothalamus enhance the acquisition of schedule-induced polydipsia.

Schedule-induced polydipsia (SIP) is affected by damage to various limbic structures that have connections with the lateral hypothalamus. The present experiment sought to determine whether or not SIP could be induced in rats bearing NMDA-induced lesions of the lateral hypothalamus. Following surgery, lesioned rats lost weight and were hypophagic and hypodipsic. Drinking, in response to systemic injection of hypertonic saline, was impaired in lesioned rats. Prior to testing for SIP, all rats were placed on a food-restriction regime to maintain body weight at 85% of normal. There was no statistically significant difference in mean body weight between lesioned and control groups before deprivation began, though lesioned rats were hypodipsic in their home cages. The lateral hypothalamic-lesioned rats acquired SIP significantly more rapidly than controls over the first six sessions, but over four following sessions no differences were present. The enhanced acquisition of SIP by lateral hypothalamic-lesioned rats cannot be accounted for by postoperative recovery of body weight or by hypodipsia in the home cage, neither of which correlated with SIP. It is suggested that the lateral hypothalamus has a role in cueing appropriate and inhibiting inappropriate behavior in conditions of motivational excitement. SIP is suggested to have two CNS components--one excitatory and one inhibitory.

Animals↗
PubMed1992

Dynamic heterogeneity of cerebral hypoperfusion after prolonged cardiac arrest in dogs measured by the stable xenon/CT technique: a preliminary study.

After prolonged cardiac arrest and reperfusion, global cerebral blood flow (gCBF) is decreased to about 50% normal for many hours. Measurement of gCBF does not reveal regional variation of flow or permit testing of hypotheses involving multifocal no-flow or low-flow areas. We employed the noninvasive stable Xenon-enhanced Computerized Tomography (Xe/CT) local CBF (LCBF) method for use in dogs before and after ventricular fibrillation (VF) cardiac arrest of 10 min. This was followed by external cardiopulmonary resuscitation (CPR) and control of cardiovascular pulmonary variables to 7 h postarrest. In a sham (no arrest) experiment, the three CT levels studied showed normal regional heterogeneity of LCBF values, all between 10 and 75 ml/100 cm3 per min for white matter and 20 and 130 ml/100 cm3 per min for gray matter. In four preliminary CPR experiments, the expected global hyperemia at 15 min after arrest, was followed by hypoperfusion with gCBF reduced to about 50% control and increased heterogeneity of LCBF. Trickle flow areas (LCBF less than 10 ml/100 cm3 per min) not present prearrest, were interspersed among regions of low, normal, or even high flow. Regions of 125-500 mm3 with trickle flow or higher flows, in different areas at different times, involving deep and superficial structures migrated and persisted to 6 h, with gCBF remaining low. These preliminary results suggest: no initial no-reflow foci (less than 10 ml/100 cm3 per min) larger than 125 mm3 persisting through the initial global hyperemic phase; delayed multifocal hypoperfusion more severe than suggested by gCBF measurements; and trickle flow areas caused by dynamic factors.

Animals↗
PubMed1992

The effects of smoking in pregnancy: a review of approaches to behavioural change.

A substantial body of evidence has now been accumulated which suggests that cigarette smoking during pregnancy can result in an increased incidence in the number of babies born of lower birth weight. There is also an increase in perinatal mortality in babies born to smoking mothers, as well as a higher incidence of spontaneous abortion, greater mortality and morbidity during the first year of life and a lower rate of growth and reduction in mental aptitude into late adolescence. Despite this compelling evidence it has been found that only a relatively small proportion of women who smoke actually stop when they become pregnant. It has been found that knowledge of the potential effects of smoking does not appear to exert a major influence on pregnant women's smoking behaviour. There is also relatively little research which addresses the reasons why some pregnant women continue to smoke during pregnancy. The issue is clearly complex and the evidence that does exist points to the need for health professionals to adopt more sophisticated interventions with pregnant women, which move beyond a simple educational approach.

Female↗
PubMed1992

The role of the paid non-professional nursing helper: a review of the literature.

This paper presents an overview of research into the role of paid non-professional nursing helpers. This term refers to auxiliaries, ward clerks, healthcare assistants and support workers. The focus of the review is on work carried out on attitudes of qualified staff to the role of the helper, role descriptions and the role of the helper in different organizational modes of work. Some of the research reviewed in relation to the role description and attitudes to the helper date back to 1978. However, the emphasis of the paper is on research published in the past 3 years. The research is reviewed against the background of two theoretical frameworks, both of which are perceived to be useful in analysing the division of labour between the nurse, the patient and the helper.

Attitude of Health Personnel↗
PubMed1992

Health education in nursing: perceptions of practice in acute settings.

A postal questionnaire survey design was utilized to establish a national overview of perceptions of health education practice in general acute ward settings. Questionnaires were sent to individuals identified as the most senior nurse within each district health authority in England (n = 195). Respondents were asked to specify--with the help of their nursing teams--the progress made on wards within their respective district health authorities in relation to a range of health education activities. A response rate of 73% (n = 142) was achieved. The majority of responses reflected the perceptions of senior nurse managers or their deputies. The data showed that respondents felt health education activities generally are a feature of nursing practice on acute wards. However, on the majority of wards, they were seen as only partially included into some areas of nursing practice. On only a small proportion (4%) of wards was health education of any type reported not to be a feature of practice. Of the five specific health education areas explored in the questionnaire, 'patient education' and 'information-giving' were felt to be occurring on a significantly greater number of wards and significantly more frequently than 'encouraging patients and their families to participate in care'. Data analysis also showed that all the activities specified--that is, patient education, information-giving, healthy lifestyle advice and encouraging patient and family participation in care--were positively correlated.

Attitude of Health Personnel↗
PubMed1992

The use of postoperative suction drainage in total hip arthroplasty.

Two hundred eight primary total hip arthroplasties were reviewed to evaluate the effect of closed suction drainage. This review included 45 hips in which closed drains were used and 163 hips in which drains were not used. These two groups were compared for possible differences in wound problems, temperature elevations, changes in Hgb/Hct, and the need for transfusions. There was no statistically significant difference in postoperative temperatures or decrease in Hgb. However, there were four superficial wound infections in the drained group and three superficial wound infections in the non-drained group (P < .025). There were no deep infections in either group. These findings suggest closed suction drainage provides no apparent advantage in uncomplicated primary total hip arthroplasty.

Aged↗
PubMed1992

10'-Desmethoxystreptonigrin, a novel analog of streptonigrin.

10'-Desmethoxystreptonigrin, a novel analog of streptonigrin produced by Streptomyces albus, was discovered in a screen for inhibitors of farnesylation of RAS p21 protein. The compound was isolated from the fermentation broth and its structure determined. It is markedly cytotoxic to several human tumor cell lines and also exhibits potent broad-spectrum antibacterial activity.

Animals↗
PubMed1992

Tendons, ligaments, and capsule of the rotator cuff. Gross and microscopic anatomy.

We investigated the structure of the myotendinous rotator cuff in thirty-two grossly intact cuffs from thirty fresh cadavera of subjects who had been seventeen to seventy-two years old at the time of death. We studied the gross anatomy of the capsule and ligaments of the cuff, as well as histological sections of the tendons of the subscapularis, supraspinatus, and infraspinatus muscles. The tendons were found to splay out and interdigitate to form a common, continuous insertion on the humerus. The biceps tendon was ensheathed by interwoven fibers derived from the subscapularis and supraspinatus tendons. The anterior margin and bursal surface of the supraspinatus tendon were enveloped by a thick sheet of fibrous tissue derived from the coracohumeral ligament. Fibers from the coracohumeral and glenohumeral ligaments were found concentrated in a plane between the capsule and the tendons of the cuff. Microscopically, in the region of the supraspinatus and infraspinatus tendons, the cuff was composed of five layers defined by the attachments and orientations of the fibrous elements in each of these layers.

Adolescent↗
PubMed1991

DNA synthesis on discontinuous templates by DNA polymerase I of Escherichia coli.

DNA polymerases normally catalyze DNA synthesis in a template-directed manner. Generally, the continuity of the phosphodiester backbone of the template strand was thought to be an absolute requirement for DNA synthesis. Here, I demonstrate that a 3'-exonuclease-deficient derivative of the Klenow (large) fragment of Escherichia coli DNA polymerase I (PolIk) can carry out DNA synthesis on discontinuous templates in vitro. Addition of multiple nucleotides (nt) to the 3' end of a blunt-end duplex, templated by unlinked single-stranded oligodeoxyribonucleotides (oligos), was monitored electrophoretically. The reaction was demonstrable with either homopolymers or mixed-sequence oligos, but showed a requirement for complementarity between the first nt added to the duplex and the 3' nt of the unlinked oligo. These results demonstrate that continuity of the phosphodiester backbone of the template strand is not absolutely required for in vitro DNA synthesis by a 3'-exonuclease-deficient form of PolIk.

Base Sequence↗
PubMed1991

Variation of collagen fiber alignment in a joint surface: a scanning electron microscope study of the tibial plateau in dog, rabbit, and man.

To determine if articular cartilage collagen fiber organization differs with location on the tibial plateau, specimens from dogs, humans, and rabbits were studied by scanning electron microscopy. Joint surfaces were fixed, dehydrated, and fractured radially so that the periphery could be compared with the center on single specimens. Generally, fibers were more tightly packed in the lateral side than in the medial and the periphery as compared with the center, where the cartilage was consistently thicker and the radial zone was dominant and composed of straight vertical fibers. In the periphery, the tangential and transitional zones were better developed and contributed up to 50% of the cartilage depth in comparison to only 5% centrally. The soft, dull, malacic appearance of the center results from lack of a true surface layer of tangential collagen fibers.

Adult↗
PubMed1991

Cell patterns in the surface of rabbit articular cartilage revealed by the backscatter mode of scanning electron microscopy.

To study the distribution of cells in the surface layer of articular cartilage, rabbit hip and knee specimens were stained with silver and studied by scanning electron microscopy (SEM). The cartilage was treated en bloc using the Gomori methenamine silver technique, which stains the nuclei of exposed cells with reduced silver. The intact surface was then studied with a binocular microscope and SEM in the backscatter mode Only those cells within 30 microns of the surface stained, permitting that population to be imaged selectively. Depressions in the surface were related to groups of cells in clusters or rows bounded by collagen fibers. This study demonstrates the effectiveness of backscatter imaging in the study of chondrocytes. The relationship between surface contours and underlying cells is more complex than previously described.

Animals↗
PubMed1991

Response of cortical bone to local controlled release of sodium fluoride: the effect of implant insertion site.

In a previous experiment, sodium fluoride in a biodegradable polymer matrix was introduced into the femoral canal of the rabbit and bone formation was compared with contralateral controls. We noted significant bone formation, but only in the distal third of the periosteal surface of the femur. This experiment was performed to distinguish fluoride-induced periosteal bone formation from that due to the reactive osteogenic changes associated with local injury caused by the process of implantation. A proximal approach on the right leg and a distal approach on the left were used for the insertion of the implants in rabbits. Femurs were removed after 30 days and tested for stiffness and load to failure. The cross-sectional area of mineralized bone was determined at proximal, midshaft, and distal locations. Fluorescent bone tissue growth labels were injected at weekly intervals to measure the rate of new periosteal bone formation. The results were compared with a control group that received sham implants. Results showed no difference between measured properties in right and left femurs in the control group or in those exposed to fluoride. A significant increase was found in the fluoride group in load to failure, along with cross-sectional area of mineralized bone, and periosteal growth rates compared with the control group, but no difference was seen in stiffness. No difference was detected between the response proximally and distally in the fluoride group regardless of the location of insertion. There were no detectable changes in serum fluoride level after implantation of the poly L-lactic acid/sodium fluoride matrix. These results show that fluoride exerts its osteogenic effects equally at proximal, midshaft, and distal regions of diaphyseal bone and is uninfluenced by the site of local injury due to insertion of the implant.

Animals↗