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Biomedical subjects

L Jones

Publications and source records attributed to L Jones.

At least 181 records · Page 10Linked to original sources
PubMed1997

Social support and the cancer patient--a need for clarity.

This paper addresses the importance of social support to the health of cancer patients, drawing upon the relevant literature from medical, psychological and social research. The development of a measure of social support for cancer patients for use in guiding health care and assessing the effects of social support on the patients health statues are needed. Various definitions of social support are considered and the difficulties of adequately defining the concept are discussed. Given the lack of a uniformed definition and emphasis on multiple aspects of social support it is argued that research should address the experiences and needs of patients with cancer. Specifically, with a view to providing a clinical measure of social support. The development of the Bottomley Social Support Scale is outlined and suggestions made for ways forward in researching and understanding social support.

Health Status↗
PubMed1997

The psychopathic individual: a lack of responsiveness to distress cues?

In this study, we investigated the psychophysiological responsiveness of psychopathic individuals to distress cues and to threatening and neutral stimuli. Eighteen psychopathic individuals and 18 incarcerated control individuals, identified using the Revised Psychopathy Checklist (Hare, 1991, The Hare Psychopathy Checklist-Revised, Toronto: Multi-Health Systems), were shown slides of these three types of stimuli, and their electrodermal responses were recorded. The psychopathic individuals showed (relative to the controls) reduced electrodermal responses to the distress cues. In contrast, the two groups did not differ in their electrodermal responses to the threatening stimuli and to the neutral stimuli. The results are interpreted within the Violence Inhibition Mechanism model (Blair, 1995, Cognition, 57, 1-29) of the psychopathic individual.

Adult↗
PubMed1997

Expression of gamma interferon by simian immunodeficiency virus increases attenuation and reduces postchallenge virus load in vaccinated rhesus macaques.

Simian immunodeficiency virus (SIV) infection of macaques is a model for human immunodeficiency virus (HIV) infection. We have previously reported the construction and characterization of an SIV vector with a deletion in the nef gene (SIV(delta nef)) and expressing gamma interferon (SIV(HyIFN)) (L. Giavedoni and T. Yilma, J. Virol. 70:2247-2251, 1996). We now show that rhesus macaques vaccinated with SIV(HyIFN) have a lower viral load than a group similarly immunized with SIV(delta nef). Viral loads remained low in the SIV(HyIFN)-vaccinated group even though SIV expressing gamma interferon could not be isolated after 6 weeks postimmunization in these animals. All immunized and two naive control macaques became infected when challenged with virulent SIV(mac251), at 25 weeks postvaccination. In contrast to the two naive controls that died by 12 and 18 weeks postchallenge, all vaccinated animals remained healthy for more than 32 weeks. In addition, postchallenge cell-associated virus load was significantly lower in SIV(HyIFN)-immunized animals than in the group vaccinated with SIV(delta nef). These findings indicate that cytokine-expressing viruses can provide a novel approach for development of safe and efficacious live attenuated vaccines for AIDS.

Animals↗
PubMed1997

The amino terminus of the F1-ATPase beta-subunit precursor functions as an intramolecular chaperone to facilitate mitochondrial protein import.

Mitochondrial import signals have been shown to function in many steps of mitochondrial protein import. Previous studies have shown that the F1-ATPase beta-subunit precursor (pre-F1beta) of the yeast Saccharomyces cerevisiae contains an extended, functionally redundant mitochondrial import signal at its amino terminus. However, the full significance of this functionally redundant targeting sequence has not been determined. We now report that the extended pre-F1beta signal acts to maintain the precursor in an import-competent conformation prior to import, in addition to its previously characterized roles in mitochondrial targeting and translocation. We found that this extended signal is required for the efficient posttranslational mitochondrial import of pre-F1beta both in vivo and in vitro. To determine whether the pre-F1beta signal directly influences precursor conformation, fusion proteins that contain wild-type and mutant forms of the pre-F1beta import signal attached to the model passenger protein dihydrofolate reductase (DHFR) were constructed. Deletions that reduced the import signal to a minimal functional unit decreased both the half-time of precursor folding and the efficiency of mitochondrial import. To confirm that the reduced mitochondrial import associated with this truncated signal was due to a defect in its ability to maintain DHFR in a loosely folded conformation, we introduced structurally destabilizing missense mutations into the DHFR passenger to block precursor folding independently of the import signal. We found that the truncated signal imported this destabilized form of DHFR as efficiently as the intact targeting signal, indicating that the primary defect associated with the minimal signal is an inability to maintain the precursor in a loosely folded conformation. Our results suggest that the loss of this intramolecular chaperone function leads to defects in the early stages of the import process.

Adult↗
PubMed1997

Dextrous hands: human, prosthetic, and robotic.

The sensory and motor capacities of the human hand are reviewed in the context of providing a set of performance characteristics against which prosthetic and dextrous robot hands can be evaluated. The sensors involved in processing tactile, thermal, and proprioceptive (force and movement) information are described, together with details on their spatial densities, sensitivity, and resolution. The wealth of data on the human hand's sensory capacities is not matched by an equivalent database on motor performance. Attempts at quantifying manual dexterity have met with formidable technological difficulties due to the conditions under which many highly trained manual skills are performed. Limitations in technology have affected not only the quantifying of human manual performance but also the development of prosthetic and robotic hands. Most prosthetic hands in use at present are simple grasping devices, and imparting a "natural" sense of touch to these hands remains a challenge. Several dextrous robot hands exist as research tools and even though some of these systems can outperform their human counterparts in the motor domain, they are still very limited as sensory processing systems. It is in this latter area that information from studies of human grasping and processing of object information may make the greatest contribution.

Artificial Limbs↗
PubMed1997

Lipid and protein deposition of N-vinyl pyrrolidone-containing group II and group IV frequent replacement contact lenses.

PURPOSE: The purpose of this study was to investigate the degree of protein and lipid deposition that occurs on N-vinyl-2-pyrrolidone (NVP) containing group II (non-ionic, high water content) and NVP containing group IV (ionic, high water content) frequent replacement hydrogel contact lens materials. METHODS: Twenty subjects were fitted with Group II (Vasurfilcon A) and Group IV (Vifilcon A) contact lenses, which were replaced monthly. The lenses were worn as a contralateral pair for 3 consecutive monthly periods. At the end of each monthly period, the lenses were collected for analysis of protein and lipid deposits. Protein deposition (following extraction) was examined by transmission UV and lipoidal deposition was examined using fluorescence spectrophotofluorimetry. RESULTS: There was a significant difference in the lipid and protein deposition profiles between the two materials. The Group II lens deposited approximately 2x more lipid (38 versus 73 fluorescence units; P < 0.0001) and the Group IV lens deposited approximately 17x more protein (488 micrograms versus 28 micrograms; P < 0.0001). Whilst the mean results across months were not significantly different for either protein or lipid (P = NS), the results revealed significant inter- and intra-subject variation. CONCLUSIONS: Protein deposition was predominantly controlled by the ionic charge of the lens materials, whereas the lipid deposition was predominantly determined by the NVP content. This study demonstrates that inter-subject variation and material characteristics significantly influence the deposition profile of hydrogel contact lens materials.

Adolescent↗
PubMed1997

Schizophrenia.

The success of treatment for people with schizophrenia can depend to a large extent on their understanding of the condition. Nurses have an important role to play in the education and support of individuals as well as their families and carers.

Antipsychotic Agents↗
PubMed1997

Protective vaccination of ferrets against canine distemper with recombinant pox virus vaccines expressing the H or F genes of rinderpest virus.

OBJECTIVE: To investigate the ability of rinderpest virus (RPV) antigens, expressed in pox virus vectors, to protect against canine distemper virus (CDV) infection in ferrets. ANIMALS: Ferrets (Mustela putorius; n = 27) with no previous exposure to CDV. PROCEDURE: Ferrets were inoculated intradermally with recombinant vaccinia viruses expressing the H gene of RPV, the F gene of RPV, the H and F genes of RPV, or fowlpox virus recombinant expressing both genes. Two ferrets were vaccinated s.c. with CDV vaccine as positive controls, and 1 group was left unvaccinated as a negative control. Blood was obtained from ferrets biweekly; antibody titer to RPV was detected by ELISA, and CDV antibody titer was measured by serum neutralization testing and ELISA. RESULTS: Partial protection was seen in all groups, with vRVFH vaccination being the most protective (60%). CONCLUSIONS AND CLINICAL RELEVANCE: A single inoculation with a vaccinia virus expressing the H and F genes of RPV was able to protect 60% of the vaccinated ferrets challenge exposed with a high dose of CDV. These results indicate the ability of RPV antigens expressed by vaccinia virus to protect ferrets against a related morbillivirus. Further, they document the safety and efficacy of a recombinant vaccinia virus vaccine for ferrets. Such vaccines may be useful given the susceptibility of ferrets to CDV and the problem of maternal antibody interfering with vaccination of young animals.

Animals↗
PubMed1997

Biochemical analysis associated with HL-60 cells incubated with various ceramic materials.

The purpose of this experiment was to determine the effect of TCP, ALCAP, and HA ceramic particles on the viability and proliferation rate of HL-60 cells in culture. Previous experiments have suggested that growing cell lines such as macrophages, fibroblasts, and endothelial cells on discs made of TCP, ALCAP, and HA induced immunochemical and morphological changes. The effect of ceramic particles (< 38 um) on HL-60 cells in culture have never been investigated. A total of 1 x 10(5) (n = 5) cells were placed in culture with 2 mg of ALCAP, TCP, HA particles, or 10 micrograms/ml lipopolysaccharides (LPS). At the end of 24, 48, and 96 hours, the cells were evaluated morphologically and then counted. The supernatants were collected and biochemical analysis for LDH and immunochemical analysis for cytokines IL-1 was performed. The data from this investigation revealed the following: (1) At the end of the 24 hour phase, the cell number in wells containing HA and ALCAP particles were lower than the control cells, whereas cells in the presence of TCP were similar to the control. (2) Microscopic evaluation of cells treated with HA showed hydropic change at 24, 48 and 96 hours. (3) At 96 hours, there were no significant changes in cell number between the groups. This phenomenon could be attributed to the depletion of nutrients within the wells or possibly the cells reaching confluence. (4) The ease of ingestion of macrophages to CPB is as follows: TCP > ALCAP > HA. (5) Biochemical analysis of markers for cellular disturbances revealed that there were no significant differences between the different group at any time point (p < 0.05).

Aluminum Compounds↗
PubMed1997

The epidemiology of louping-ill, a tick borne infection of red grouse (Lagopus lagopus scoticus).

The epidemiology of louping-ill in red grouse was studied in northern Britain concentrating on the possible role of other species and mechanisms of disease persistence. This tick borne viral disease caused heavy mortality in red grouse, particularly chicks. Louping-ill induced mortality reduced the strength of the density dependence that generates the tendency of grouse populations to cycle and in some populations may cause population sinks. Four routes of transmission were examined and non-viraemic transmission of virus between ticks cofeeding on hares was considered significant. Field data supported the hypothesis that disease dynamics is influenced greatly by mountain hares, both as passive amplifiers and as hosts for the tick vector. Genetic variation in louping-ill within Britain was small.

Animals↗
PubMed1996

Costs and cost effectiveness of health checks conducted by nurses in primary care: the Oxcheck study.

OBJECTIVE: To measure the costs and cost effectiveness of the Oxcheck cardiovascular risk factor screening and intervention programme. DESIGN: Cost effectiveness analysis of a randomised controlled trial using clinical and economic data taken from the trial. SETTING: Five general practices in Luton and Dunstable, England. SUBJECTS: 2205 patients who attended a health check in 1989-90 and were scheduled for re-examination in 1992-3 (intervention group); 1916 patients who attended their initial health check in 1992-3 (control group). Participants were men and women aged 35-64 years. INTERVENTION: Health check conducted by nurse, with health education and follow up according to degree of risk. MAIN OUTCOME MEASURES: Cost of health check programme; cost per 1% reduction in coronary risk. RESULTS: Health check and follow up cost 29.27 pounds per patient. Estimated programme cost per 1% reduction in coronary risk per participant was between 1.46 pounds and 2.25 pounds; it was nearly twice as much for men as women. CONCLUSIONS: The cost to the practice of implementing Oxcheck-style health checks in an average sized practice of 7500 patients would be 47,000 pounds, a proportion of which could be paid for through staff pay reimbursements and Band Three health promotion target payments. This study highlights the considerable difficulties faced when calculating the costs and benefits of a health promotion programme. Economic evaluations should be integrated into the protocols of randomised controlled trials to enable judgments to be made on the relative cost effectiveness of different prevention strategies.

Adult↗