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Biomedical subjects

K Wood

Publications and source records attributed to K Wood.

At least 55 records · Page 3Linked to original sources
PubMed1997

Effect of a centralizing device on cement mantle deficiencies and initial prosthetic alignment in total hip arthroplasty.

Sixty consecutive patients undergoing a primary hybrid total hip arthroplasty were randomized to receive a femoral component either with or without a distal centralizing device. The group with a centralizer had significantly fewer patients with cement mantle deficiencies (excessively thin areas of cement) than the group without a centralizer (P < .001). Furthermore, the centralizer group was, on average, in a neutral alignment, whereas the group without a centralizer was in a varus alignment (P < .001). It was concluded that the distal centralizing device significantly decreases the incidence of cement mantle deficiences and reproducibly aids in achieving a more neutral prosthetic alignment.

Bone Cements↗
PubMed1997

Barriers to cervical screening: women's and health workers' perceptions.

Cancer of the cervix is the most common cause of cancer mortality among Black South African women. Mortality can be reduced by an effective screening programme. Such a programme is being considered for implementation in South Africa. It is important that the implementation of a national screening programme be based on solid understanding of the current situation as well as the anticipated barriers to the effectiveness of the programme. This qualitative study was done at three rural sites in order to explore the barriers to effective utilisation of cervical screening from the perspectives of women and health workers. The aim was to inform the local service organisers as well as the policy process when planning the new screening programme. There were interesting similarities and differences between the barriers that were identified by the health workers and those by the women. Those identified by the health workers included several structural problems associated with the service such as busy clinics and problems of access including lack of transport, the mobility of the people and opposition from men. None of the women spoke of these service and access factors. Women emphasised issues surrounding the actual procedures which were based on their experiences and information they had gained from friends and other community networks. The barriers identified by women are amenable to change through careful attention to health education and the circumstances of the test. If the new screening policy is to be implemented nationally and be successful in recruiting cervical cancer cases, nurses will have a key role in identifying and overcoming barriers to smear uptake at a local level. This study has shown the importance of listening to patients in this process.

Adult↗
PubMed1997

The use of surface EMG power spectral analysis in the evaluation of back muscle function.

The rate of decline in the median frequency (MF) of the surface EMG power spectrum (MFgrad) has been evaluated for its use in monitoring the fatigability of the erector spinae muscles during the performance of submaximal isometric contractions. MFgrad consistently displayed a highly significant relationship with endurance time for the task (p < 0.05), giving a slightly better correlation for contractions performed in lordotic postures, with the back muscles in a shortened position, than in flexed postures. No significant difference existed between mean MFgrad values recorded from the right and left erector spinae muscles, at either thoracic or lumbar levels. The back extensor muscles of men were more fatigable than those of women, and this has been discussed in relation to corresponding differences in muscle fiber type relative size. Greater erector spinae muscle fatigability was associated with both the existence of, and the risk of developing, serious low back pain. Possible mechanisms for the association, from retrospective and prospective points of view, have been advanced.

Analysis of Variance↗
PubMed1997

Backstreet abortion: women's experiences.

AIM: This was a descriptive study aimed at exploring the personal experiences of women who induce abortion and the circumstances surrounding induced abortion. METHODS: The study was conducted in six public hospitals in four different provinces: Baragwanath (Gauteng), Groote Schuur and Tygerberg (Western Cape), King Edward and R.K. Khan (Kwa-Zulu/Natal) and Livingstone (Eastern Cape). In-depth interviews were conducted with 25 African, Indian and Coloured women admitted to the hospitals following backstreet abortions. The study gave women the opportunity to "speak for themselves" about "why" and "how" and the context in which the unsafe induced abortions occurred. RESULTS: The findings show that a host of factors were important in the circumstances leading to unwanted pregnancy and induced abortion: socio-economic, cultural, psychological and societal. Disempowerment in relationships combined with financial pressures constituted the background as to why women felt forced to terminate their pregnancies. The perceived need for termination was found to over-ride all other considerations, including religious ones. The ways in which women attempted to procure abortion, both through legal and illegal routes, are presented. Wider social and legal discourses an abortion were found to be an important factor in how women experienced their situation.

Abortion, Induced↗
PubMed1996

A phase-I study of the safety, pharmacokinetics, and antiviral activity of combination didanosine and ribavirin in patients with HIV-1 disease. AIDS Clinical Trials Group 231 Protocol Team.

A phase-I study was conducted to examine the safety, pharmacokinetics, and activity of combination 2',3'-dideoxyinosine (ddI) and ribavirin against human immunodeficiency virus type 1 (HIV-1)-positive individuals with CD4+ cell counts of < or = 500/microliter. Nineteen patients were enrolled into the study in which ddI monotherapy (200 mg p.o.b.i.d.) was administered for the first 4 weeks, followed by the coadministration of ribavirin (600 mg p.o.q.d.) and ddI (200 mg p.o.b.i.d.) for 8 or 20 additional weeks. The combination regimen was safe and well tolerated. Three patients did not complete 12 weeks of the study because of adverse events or voluntary withdrawal. The pharmacokinetic studies performed at weeks 4, 6, and 12 on specimens collected from the 15 individuals who completed 12 weeks of therapy revealed no pharmacokinetic interaction between ddI and ribavirin. A significant decline from baseline in HIV-1 titer as measured by quantitative HIV-1 culture was detected both during the ddI-monotherapy phase (week 4, p < 0.001) and during the combination-therapy ddI + ribavirin phase (week 12, p < 0.001); the median drop observed was 0.90 log10 at week 4 and 0.92 log10 at week 12. While the addition of ribavirin did not result in further reductions in viremia in the following weeks on study treatment, 13 (81%) of the 16 patients had at least a -0.5 log10 change in viral titer at week 12. The median decline in plasma viral RNA was 0.68 log10 at week 4(p < 0.001) and 0.67 log10 at week 12 (p = 0.005). CD4+ cell counts increased above baseline significantly during the ddI-monotherapy phase of the study (p = 0.0038). The median increase was +26 cells/mm3 at week 4 and +11 cells/mm3 at week 12; for patients who remained on treatment through 24 weeks, the median CD4+ cell count increase was +10 cells/mm3. The L74V ddI resistance-conferring HIV-I reverse-transcriptase mutation emerged in 53% of the patients. Patients with non-syncytium-inducing HIV variants demonstrated greater responses to treatment with larger decreases in virus load and greater increases in CD4+ cell count. Our results reveal that the combination of ddI and ribavirin in HIV-positive patients is safe, well tolerated, without adverse pharmacologic interaction, and associated with significant and sustained declines in virus load over 12 weeks of therapy.

Adult↗
PubMed1996

Immunosuppression with monoclonal antibodies and CTLA4-Ig after myoblast transplantation in mice.

Various combinations of monoclonal antibodies specific for lymphocyte cell surface antigens and a recombinant molecule (CTLA4-Ig) were used to immunosuppress mice after transplantation of MHC-incompatible myoblasts. To assess the effectiveness of the immunosuppression, the donor myoblasts were obtained from a transgenic mouse (TnI LacZ1/29) containing a beta-galactosidase (beta-gal) reporter gene under the control of a muscle-specific promoter. No muscle fibers expressing beta-gal were observed 1 month after the myoblast transplantation, when the animals were not immunosuppressed or were treated with CTLA4-Ig alone. Approximately 50% of the muscle fibers expressed the beta-gal reporter gene 1 month after transplantation in mice treated with CTLA4-Ig combined with an anti-CD4 monoclonal antibody and in mice treated with a combination of anti-CD4, anti-CD8, and anti-lymphocyte function-associated antigen-1. The percentage of beta-gal-labeled muscle fibers increased to 94% when this combination of the three monoclonal antibodies was administrated weekly for 3 weeks. Although excellent graft survival rates were obtained 1 month after transplantation, reflecting an effective immunosuppression by these three treatments, no beta-gal-positive fibers were found 2 months after the transplantation, indicating the inability of these immunosuppressive agents to maintain long-term graft survival and induce tolerance to the myoblasts and muscle fibers of donor origin.

Abatacept↗
PubMed1996

The Th1/Th2 paradigm and the allograft response.

Although Th1- and Th2-type cytokine profiles have been associated with rejection and tolerance respectively, this paradigm may not be completely accurate. Instead, recent studies suggest that there could be a hierarchy of T-cell growth factors with regard to their ability to block tolerance and induce rejection (rather than a polarized Th1/Th2 demarcation).

Animals↗
PubMed1996

Current research on the immunomodulatory effect of allogeneic blood transfusion.

This review summarizes three aspects of current research on the immunomodulatory effect of allogeneic transfusion. Representatives of three laboratories-each of which is actively engaged in research on transfusion-induced immunomodulation-summarize their current investigative approach. First, current animal models of transfusion-induced immunomodulation are presented and research on the tumor growth-promoting effect of allogeneic transfusion is described. Second, mechanisms underlying an immunomodulatory effect of transfusion are summarized and experiments on the induction of transplant tolerance by selective introduction of donor-type MHC antigens is presented. Third, the potential clinical impact of increased infection and tumor recurrence resulting from transfusion-induced immunomodulation is assessed. The potential role of donor-derived hematopoietic stem cells is presented as an area of future investigation in the area of transfusion-induced immunomodulation.

Adoptive Transfer↗
PubMed1996

A community based approach to bicycle helmet use counts.

OBJECTIVE: Bicycle helmet use has become an important measure of the effectiveness of bicycle safety programs and the effectiveness of helmet legislation. Accounts of analytical comparisons of observation site selection methods are scarce. This report addresses this gap by reporting the relative effectiveness and costs of two alternative approaches to the selection of observation sites for helmet use counts. METHODS: The community based (COBA) method of site selection entailed asking community informants to identify locations frequented by young bicycle riders. In the bicycle club/map (CLMA) method, site selections were based on recommendations from club members of sites at which cyclists were likely to be found and through examination of maps, keying on local features. These alternative site selection methods were compared in terms of their overall and cost effectiveness in locating youth riders. RESULTS: Despite fewer observer hours and fewer sites in a sparsely populated rural county, the COBA method yielded greater numbers of riding youth and from 1.9 to 4.6 times more youth riders per observer hour than did the CLMA method in two densely populated suburban counties. In addition, costs per youth rider observed associated with the COBA method were 2.9 to 7.0 times lower than those associated with the CLMA method. CONCLUSIONS: Community based site identification is both more efficient in locating youth riders and more cost effective.

Bicycling↗
PubMed1996

Synergy, activity and tolerability of zidovudine and interferon-alpha in patients with symptomatic HIV-1 infection: AIDS Clincal Trial Group 068.

Thirty-four subjects with symptomatic HIV-1 infection, p24 antigenaemia, and CD4 cell counts > 200/mm3 were randomly assigned to receive treatment with either zidovudine (ZDV) orally, interferon-alpha (IFN-alpha) subcutaneously, or both at respective low (200 mg ZDV/ 2 million international units IFN-alpha (MIU)), middle (400 mg/4 MIU) or high (600 mg/6 MIU) daily dose levels for 12 weeks. Thereafter, all patients received combination therapy at the initially assigned dose level to a total of 96 weeks. This design permitted analysis by the combination index (CI) method, which demonstrated antiretroviral synergy between ZDV and IFN-alpha with respect to p24 antigen suppression. Over the first 12 weeks, combination therapy was acceptably tolerated, more so than IFN-alpha monotherapy, and it was significantly more active in suppressing antigenaemia than either of the monotherapies. Similarly, the high-dose combination was the most active dose level over weeks 12 to 96. Combination ZDV/IFN-alpha at the optimal dose level defined by this trial merits further study. In addition, the CI design strategy employed here may be useful for the investigation of new antiretroviral combinations.

Administration, Cutaneous↗
PubMed1995

The effect on hospital admissions of psychiatric case management involving general practitioners: preliminary results.

A two year follow-up of two matched groups of subjects with chronic severe mental illness was performed in order to evaluate a new psychiatric case management system. One group (n = 59) received care through psychiatric case management, using an assertive community treatment model that directly involved general practitioners. The other group, matched for age, sex, diagnostic group and number of hospital admissions, received standard outpatient care. Comparing the two years before and after case management, the experimental group showed a dramatic fall in inpatient admission days while the control group admission days remained the same (median difference in admission days across matched subject pairs = 64.5, 95% C.I. from 134.5 to 16). The experimental group remained out of hospital longer before first readmission (Kaplan-Meier survival analysis, P = 0.002). This type of case management programme can shorten or prevent admissions to psychiatric hospitals of patients with chronic mental illness, and increase their time before readmission.

Adolescent↗
PubMed1995

Significance of touch for perceptions of parenting and psychological adjustment among adolescents.

OBJECTIVE: This pilot study set out to investigate whether a relationship exists between differential quality and quantity of physical contact experience and perceptions of parenting, psychological adjustment, and suicidal behavior among adolescents. METHOD: A self-report questionnaire assessed individuals' perceptions of how frequently they experienced pleasant (positive) and unpleasant (negative) touch from family and friends. Together with the Achenbach Youth Self-Report and the Parental Bonding Instrument, this questionnaire was administered to 142 male and 129 female students aged between 13 and 15 years (mean = 13.54, SD = 0.56) attending a randomly chosen metropolitan state high school and a coeducational private school. RESULTS: The major findings indicated that differential quality and quantity of physical contact experience was related to perceptions of parenting, psychological adjustment, and suicidal behavior, although a gender difference was observed. CONCLUSIONS: The findings suggest that physical contact experiences may reflect different parenting styles and may be a vulnerability factor for a range of difficulties among adolescents.

Adaptation, Psychological↗
PubMed1995

Mechanisms and clinical manifestations of supraventricular tachycardias.

Supraventricular tachycardia (SVT) is used as a general label for a variety of fast heart rhythms originating in any part of the conduction system above the ventricles. Supraventricular tachycardia encompasses subclasses of tachycardias such as: atrioventricular nodal reentrant tachycardia (AVNRT), atrioventricular reciprocating tachycardia (AVRT), atrial tachycardia, and atrial flutter. Nurses may encounter patients with these common types of dysrhythmias in inpatient or outpatient settings. Supraventricular tachycardia causes numerous symptoms which may make life difficult for these patients. This article reviews the mechanisms, prevalence, clinical manifestations, and treatment options for each of the major types of supraventricular tachycardia. Radiofrequency ablation has currently made the treatment options more optimistic for these patients than in past years. Further research needs to be done on if, or how, these patients' symptoms and quality of life change after ablation.

Catheter Ablation↗