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Biomedical subjects

A M Smith

Publications and source records attributed to A M Smith.

At least 181 records · Page 10Linked to original sources
PubMed1996

Unilateral hip replacement causes bilateral changes in tibial bone mineral content in a canine model.

The presence of asymmetry in tibial bone mineral content (BMC) of the operated and control limbs at the end of the experimental period following unilateral hip replacement surgery is used as a marker of limb function. The goal of the present study was to determine the contribution of ipsilateral and contralateral bone gain and loss to control-treated side differences in BMC of the tibia in dogs following unilateral hip replacement surgery. Seven animals were followed longitudinally with single beam photon absorptiometry for 6 months after unilateral hip hemiarthroplasty. Bone loss, compared with preoperative baseline values, was observed in both limbs, with recovery in bone mass beginning 1 month after surgery in the contralateral tibia and 3 months after surgery in the ipsilateral tibia. Thus, the asymmetry in tibial BMC frequently seen after unilateral experimental hip replacement in the canine appears to be caused by differential timing of recovery of bone mass following a transient loss in both limbs. The mechanism defined in this study is in contrast to an alternative mechanism involving bone loss in the treated limb coupled with bone gain in the control limb.

Animals↗
PubMed1996

Transfer of a pertussis toxin expression locus to isogenic bvg-positive and bvg-negative strains of Bordetella bronchiseptica using an in vivo technique.

Bordetella pertussis is the causative agent of whooping cough, a contagious childhood respiratory disease, increasing public concern over the safety of current whole-cell vaccines has led to decreased immunization rates and a subsequent increase in the incidence of the disease. The preparation of safer vaccines is at present concentrated on the production of detoxified virulence factors such as pertussis toxin (PT) for inclusion in acellular vaccine preparations. A permanently avirulent Bordetella bronchiseptica strain was previously engineered to constitutively produce PT. An in vivo cloning technique, based on the principles of conjugal mating and chromosome transfer was employed to transfer the PT expression locus of this strain to virulent and avirulent strains of B. bronchiseptica. This transfer was confirmed by Southern hybridization. An analysis of PT secretion in isogenic virulent and avirulent strains of B. bronchiseptica revealed that the PT produced was cell-associated and not secreted to the growth medium. This evidence suggests that B. bronchiseptica does not possess functional PT secretion (ptl) genes. Therefore, to achieve a PT expression and secretion system suitable for vaccine purposes in Bordetella bronchiseptica, functional ptl genes of B. pertussis are also required.

Bordetella bronchiseptica↗
PubMed1996

Mouse monoclonal antipeptide antibodies specific for cholesteryl ester transfer protein (CETP).

A synthetic peptide whose amino acid sequence corresponds to residues 131-142 of human cholesteryl ester transfer protein (CETP) was used as an immunogen to generate a panel of monoclonal antibodies (MAbs) specific for the intact CETP molecule. Spleen cells from BALB/c mice immunized with the peptide conjugated with keyhole limpet hemocyanin (KLH) were fused with SP2/0 myeloma cells. Two MAbs that bound fixed peptide in an enzyme-linked immunoabsorbent assay (ELISA) were partially characterized regarding their specificity and biological activity. ATM192 of the IgG1 subclass and J16-14 of the IgG3 subclass were used in a Western blot assay as well as in the ELISA. We have also shown through the use of immunoprecipitation that ATM192 can remove CETP enzyme activity from human serum without destroying the enzyme's activity. We have also shown that the antibodies can bind CETP from rabbits. The specificity studies and the lack of inhibition of enzymatic activity suggest that the MAbs bind a structural area of the CETP molecule not a part of the active binding site of the enzyme. We conclude that these antibodies can be valuable as tools for studying CETP levels in human serum as well as in tissue homogenates from rabbits and humans.

Animals↗
PubMed1996

Euthanasia: the law in the United Kingdom.

The regulation of euthanasia by the criminal law has tended to be one of the more contentious areas of medical law, and continues to be the subject of debate. Few areas of the criminal law have been so consistently the target of reformist pressure, and certainly few areas have so strongly resisted change. Understandably, legislators are unwilling to involve themselves in a matter of law reform which engenders such moral disagreement, and it is significant that only two jurisdictions-The Netherlands and the Australian Northern Territories-have made any substantial change in their legal practice in this area. In other countries, including the UK, the courts and legislators have consistently refused to remove the fundamental criminal law objection to the practice of euthanasia. This is not to say, of course, that the courts have failed to recognise the medical subtleties in medical treatment at the end of life; in several important decisions, the courts in Britain have considered the boundaries of the criminal law's protection of life and have offered guidelines for doctors facing the delicate issues associated with treating the dying patient. Yet, in spite of several helpful decisions from the courts, the basic principle remains firm: the criminal law does not countenance the taking of life, no matter how good the motive. This means that there are very clear legal limits to the extent to which doctors can follow their individual consciences in this area.

Adult↗
PubMed1996

Evidence that a 77-kilodalton protein from the starch of pea embryos is an isoform of starch synthase that is both soluble and granule bound.

In this paper we provide further evidence about the nature of a 77-kD starch synthase (SSII) that is both soluble and bound to the starch granules in developing pea (Pisum sativum L.) embryos. Mature SSII gives rise to starch synthase activity when expressed in a strain of Escherichia coli lacking glycogen synthase. In transgenic potatoes (Solanum tuberosum L.) expressing SSII, the protein is both soluble and bound to the starch granules. These results confirm that SSII is a starch synthase and indicate that partitioning between the soluble and granule-bound fraction of storage organs is an intrinsic property of the protein. A 60-kD isoform of starch synthase found both in the soluble and granule-bound fraction of the pea embryos is probably derived by the processing of SSII and is a different gene product from GBSSI, the exclusively granule-bound 59-kD isoform of starch synthase that is similar to starch synthases encoded by the waxy genes of cereals and the amf gene of potatoes. Consistent with this, expression in E. coli of an N-terminally truncated version of SSII gives rise to starch synthase activity.

Amino Acid Sequence↗
PubMed1996

The major form of ADP-glucose pyrophosphorylase in maize endosperm is extra-plastidial.

Preparations enriched in plastids were used to investigate the location of ADP-glucose pyrophosphorylase (AGPase) in the developing endosperm of maize (Zea mays L.). These preparations contained more than 25% of the total activity of the plastid marker enzymes alkaline pyrophosphatase and soluble starch synthase, less than 2% of the cytosolic marker enzymes alcohol dehydrogenase and pyrophosphate, fructose 6-phosphate 1-phosphotransferase, and approximately 3% of the AGPase activity. Comparison with the marker enzyme distribution suggests that more than 95% of the activity of AGPase in maize endosperm is extra-plastidial. Two proteins were recognized by antibodies to the small subunit of AGPase from maize endosperm Brittle-2 (Bt2). The larger of the two proteins was the major small subunit in homogenates of maize endosperm, and the smaller, less abundant of the two proteins was enriched in preparations containing plastids. These results suggest that there are distinct plastidial and cytosolic forms of AGPase, which are composed of different subunits. Consistent with this was the finding that the bt2 mutation specifically eliminated the extraplastidial AGPase activity and the larger of the two proteins recognized by the antibody to the Bt2 subunit.

Alcohol Dehydrogenase↗
PubMed1996

Identification of the major starch synthase in the soluble fraction of potato tubers.

The major isoform of starch synthase from the soluble fraction of developing potato tubers has been purified and used to prepare an antibody and isolate a cDNA. The protein is 140 kD, and it is distinctly different in predicted primary amino acid sequence from other isoforms of the enzyme thus far described. Immunoinhibition and immunoblotting experiments and analysis of tubers in which activity of the isoform was reduced through expression of antisense mRNA revealed that the isoform accounts for approximately 80% of the activity in the soluble fraction of the tuber and that it is also bound to starch granules. Severe reductions in activity had no discernible effect on starch content or amylose-to-amylopectin ratio of starch in tubers. However, they caused a profound change in the morphology of starch granules, indicative of important underlying changes in the structure of starch polymers within the granule.

Amino Acid Sequence↗
PubMed1996

Changes in heterosexual university undergraduates' HIV-related knowledge, attitudes and behaviour: Melbourne, 1989-1994.

OBJECTIVE: To examine differences in the AIDS-related knowledge, attitudes and behaviours of first year university undergraduates in 1989 and 1994. DESIGN: Comparisons were made between cross-sectional surveys, conducted in 1989 and 1994, of first year undergraduates at three Melbourne universities. RESULTS: The 1994 cohort reported more positive attitudes toward, and better knowledge of, safe sex practices and less discrimination against perceived risk groups than did the 1989 cohort; however, this was due primarily to improvement among female undergraduates. Male undergraduates either demonstrated no improvement or a decline in pro-safe sex attitudes. A general increase was found in the proportion of respondents always using condoms for vaginal sex with casual and regular partners and for oral sex with casual and regular partners. CONCLUSIONS: While the extent of sexual behaviour among these young people has remained essentially unchanged over the past five years, the extent of self-reported condom use has increased markedly. The general decline in attitudinal measures among young men contrasts with a marked improvement among young women and suggests the need for education programs targeted specifically at this group.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Subjective scaling of smooth surface friction.

1. Six men and four women, 30-51 yr of age, were asked to use the tip of the washed and dried index finger to stroke six different featureless, flat surfaces mounted on a three-dimensional force platform. The six surfaces were rosin-coated glass, glass, satin-finished aluminum, poly-vinyl chloride (PVC) plastic, Teflon, and nyloprint (polyamide plastic). The subjects were requested to indicate where the sensation produced by each surface should be placed on an unidimensional scale represented by an 18cm line labeled at one end by the words "most slippery" and at the other end by the words "most sticky." The coefficients of friction for each surface and for each subject were subsequently assessed by asking each subject to stroke the surfaces as if they were assessing its slipperiness for 5 s. 2. The finger forces normal and tangential to the stroked surfaces were digitized at 250 Hz and stored on a laboratory computer. The ratio of the mean tangential force to the mean perpendicular force during stroking was used to calculate the mean coefficient of kinetic friction. The mean friction for all subjects ranged from 0.43 for the nyloprint surface to 2.79 for the rosin-coated glass. Correlation coefficients calculated between the subjective estimates of friction and the measured coefficients of friction for each subject individually resulted in a mean correlation of 0.85 (n = 10, P < 0.001). 3. These data indicate that subjects can accurately scale relative differences in the friction of macroscopically smooth, flat surfaces, by modulating the tangential force applied to the finger while keeping the normal force relatively constant. The fact that subjects maintained a relatively constant normal force and instead varied the tangential force across different surfaces suggests that receptors sensitive to these tangential forces are important in the perception of smooth surface friction.

Adult↗
PubMed1996

Friction, not texture, dictates grip forces used during object manipulation.

1. Three men and seven women, 25-40 yr of age, were asked to use the thumb and index fingers to grasp, lift, and hold the armature of a linear motor generating a 2.0-N opposing force (simulating an object weighing approximately 200 g) for 2 s. The surface in contact with the fingers was composed of smooth or polyamide plastic etched with 1.0-mm high Braille beads separated at 2.0- or 3.0-mm intervals measured from apex to apex. The surfaces were left either untreated or coated with talc, water, or sucrose films designed to change the coefficient of friction with the skin. Talc reduced the coefficient of friction, whereas water and sucrose both increased the friction against the skin. In all, 12 surface conditions were used to evaluate the effects of texture and friction on the grip force during lifting and holding. 2. For all subjects the inverse coefficient of friction was associated with proportionately scaled increases in grip force, regardless of surface texture. The peak lifting force as well as the static force used to hold the object stationary were significantly correlated with the inverse of the coefficient of friction. When coatings were applied to dissimilar surface textures to produce similar coefficients of friction, the grip force profiles were nearly identical. When strong adhesives increased the friction of the smooth surface compared with textured surfaces, grip forces decreased as friction increased. That is, although the untreated smooth surface had less friction than either of the two textured surfaces, the addition of sucrose increased the smooth surface friction to a higher level than either of the similarly treated textured surfaces. As a result, the effect of surface friction could be dissociated from the effect of either surface texture or coating. Friction appears to be a more important factor in determining the grip force than either texture or surface films at least for the range of textures and coatings examined in this study.

Adhesiveness↗
PubMed1996

Survey of hospice and palliative care inpatient units in the UK and Ireland, 1993.

A survey of the inpatient palliative care services throughout Great Britain and Ireland was undertaken, enquiring about activity for the year 1993. This is one in a series of annual surveys of the various aspects of palliative care. Questionnaires were sent out at the end of April 1994, and 174 replies were received from 200 initially sent (87%). Replies were analysed by the Hospice Information Service. The report gives details of admissions, deaths and discharges and considers length of patient stay and bed occupancy. A discussion of the apparent discrepancies in the reported statistics is included. Palliative care for children is separately considered, and admissions of noncancer patients are detailed.

Bed Occupancy↗
PubMed1996

Continuing education and short courses.

Requirements for healthcare professionals in the United Kingdom to undertake continuing education are discussed. For nurses, midwives and many career-grade doctors, formal arrangements are in place; for other professionals, continuing education is recommended but not yet a formal requirement. In order to explore what is available, courses, conferences and seminars advertised in the Hospice Information Service's publication Choices for the academic year September 1994 to July 1995 are reviewed in terms of number, intended audience, participants and duration. Comment is offered on size of events and their financing. Issues of approval, quality assurance and evaluation are addressed. Suggestions are offered with regard to future financing of courses, and co-ordination of planning and provision. It is suggested that the National Council for Hospice and Specialist Palliative Care might encourage increasing co-operation between units in the provision of education.

Cost-Benefit Analysis↗
PubMed1996

Psychological impact of injuries in athletes.

Although research on the psychological impact of injury is in its infancy, this article reviews relevant literature focusing on post-injury emotional response, self-esteem, and the effect of mood disturbance on rehabilitation from sport injury. Injury is often accompanied by depression, tension, anger and low self-esteem, particularly in competitive, seriously injured athletes. Mood disturbance seems to relate to the athlete's perceived progress in rehabilitation and has been shown to negatively relate to attendance at rehabilitation sessions. This article also describes how the Emotional Responses of Athletes to Injury Questionnaire (ERAIQ) serves as a guide for the initial interview of an injured athlete. Interventions such as positive self-talk, relaxation, goal setting and healing imagery, all used by a faster healing group of athletes, and although not well researched, seem appropriate to assist athletes in coping with injury. Modelling interventions during injury rehabilitation have also been shown to have a positive effect on rehabilitation and should be used. These relationships are described in more depth and in the context of a theoretical model. Directions for future research are suggested.

Adaptation, Psychological↗