Reliability of an isokinetic test of muscle strength and endurance

Funding for this study was provided by the U.S. Army Medical Research and Development Command, Project No. 85PP5866, under the Joint Working Group on Drug Dependent Degradation in Military Performance Program. The opinions or assertions contained herein are private ones of the authors and are not to be construed as official or reflecting the views of the Department of Defense or the Uniformed Services University of the Health Sciences. The reliability of an isokinetic test of muscle strength and endurance was evaluated. Eleven males and 9 females underwent testing on three separate occasions, 2-4 days apart. The protocol included a velocity spectrum test (VST-5 repetitions at velocities ranging from 90-330 degrees /sec) and a muscle endurance test (number of contractions performed in 45 sec at 180 degrees /sec). In the VST, no significant within-subject test day differences were noted at any velocity. Reliability was generally higher at slower velocities and higher for knee extension than flexion. Mean intraclass correlation coefficients (ICCs) for peak torque across velocities were 0.88 for extension and 0.79 for flexion. For the endurance test, two reliable measures were total work performed and average power (ICCs = 0.92); relative endurance measures had ICCs of less than 0.80. Thresholds for demonstrating experimental effects and the number of subjects to test at different detection levels are-recommended.J Orthop Sports Phys Ther 1989;10(8):315-322.     

Prophylaxis in recurrent unipolar depression: a new indication for treatment studies

Antidepressants are used for long periods of time and until recently there were no formal requirements for establishing efficacy in the maintenance phase or the prophylactic phase of the treatment of depression. The CPMP guidelines advise regulatory authorities in the EEC to consider the efficacy of antidepressants in the medium and the long term separately from efficacy in the treatment of the acute episode. This paper reviews the efficacy of antidepressants in continuation treatment and prophylactic treatment of unipolar depression. Prophylactic studies are difficult and time consuming and it is important to adopt adequate trial methodology. The minimum criteria for the demonstration of prophylactic efficacy are presented.     

IL-6–174G/C genotype is associated with the bone mineral density response to oestrogen replacement therapy in post-menopausal women

A reduction in interleukin-6 (IL-6) activity may contribute to the beneficial effects of hormone replacement therapy (HRT) on the menopausal decline in bone mineral density (BMD). We have examined this hypothesis using a genetic strategy. The –174C (rather than G) IL-6 gene variant is associated with lower IL-6 expression. As such, we might anticipate the C allele to be associated with a greater response to HRT. We have tested this hypothesis. Mean three-site [spine (L1-L4), neck of femur, and Wards triangle] BMD was measured in 65 women in a 1-year randomised controlled trial of HRT with 0.625 mg oestrogen/day and 0.15 mg norgestrel (n=30). Baseline BMD was genotype-independent for both the control and HRT group. In the control group, the percentage change in BMD after 1 year was similar between genotypes (P=0.45). In contrast, in the HRT group, the rise was genotype-dependent. Those homozygous for the G allele showed a 3.62 (2.14)% increase in BMD compared with 10.44 (4.68)% for the C-homozygous group. Heterozygotes had an intermediate BMD increase of 5.6 (2.82)% [P=0.006 (P value for interaction between HRT and genotype was 0.04)] Although the study was limited by its small sample size, these are the first data to demonstrate the importance of IL-6 genotype in determining response to oestrogen therapy, rather than its physiological withdrawal.     

Socioeconomic disparities in intimate partner violence against Native American women: a cross-sectional study

Background

Intimate partner violence (IPV) against women is a global public health problem, yet data on IPV against Native American women are extremely limited. We conducted a cross-sectional study of Native American women to determine prevalence of lifetime and past-year IPV and partner injury; examine IPV in relation to pregnancy; and assess demographic and socioeconomic correlates of past-year IPV.

Methods

Participants were recruited from a tribally-operated clinic serving low-income pregnant and childbearing women in southwest Oklahoma. A self-administered survey was completed by 312 Native American women (96% response rate) attending the clinic from June through August 1997. Lifetime and past-year IPV were measured using modified 18-item Conflict Tactics Scales. A socioeconomic index was created based on partner's education, public assistance receipt, and poverty level.

Results

More than half (58.7%) of participants reported lifetime physical and/or sexual IPV; 39.1% experienced severe physical IPV; 12.2% reported partner-forced sexual activity; and 40.1% reported lifetime partner-perpetrated injuries. A total of 273 women had a spouse or boyfriend during the previous 12 months (although all participants were Native American, 59.0% of partners were non-Native). Among these women, past-year prevalence was 30.1% for physical and/or sexual IPV; 15.8% for severe physical IPV; 3.3% for forced partner-perpetrated sexual activity; and 16.4% for intimate partner injury. Reported IPV prevalence during pregnancy was 9.3%. Pregnancy was not associated with past-year IPV (odds ratio = 0.9). Past-year IPV prevalence was 42.8% among women scoring low on the socioeconomic index, compared with 10.1% among the reference group. After adjusting for age, relationship status, and household size, low socioeconomic index remained strongly associated with past-year IPV (odds ratio = 5.0; 95% confidence interval: 2.4, 10.7).

Conclusions

Native American women in our sample experienced exceptionally high rates of lifetime and past-year IPV. Additionally, within this low-income sample, there was strong evidence of socioeconomic variability in IPV. Further research should determine prevalence of IPV against Native American women from diverse tribes and regions, and examine pathways through which socioeconomic disadvantage may increase their IPV risk.

     

Cytostasis of different tumours by a murine PPD-reactive CD4+ T lymphocyte clone is mediated by interferon-gamma and tumour necrosis factor alone or synergistically.

We have shown that a murine CD4+ PPD-reactive T lymphocyte clone was weakly cytotoxic towards the syngeneic tumour B16 melanoma and MC6A fibrosarcoma which had been coated with PPD using a monoclonal antibody-PPD heteroconjugate. Cell-free supernatants produced by PPD-stimulated T lymphocyte clones were however highly cytostatic for the two tumour targets when assayed over 48-72 h. In this study we have demonstrated good titres of tumour necrosis factor (TNF) and interferon-gamma (IFN-gamma) in the supernatants, which accounted for their observed cytostatic activity on the tumour targets. The high level of cytostasis seen with the B16 melanoma using the supernatants could be attributed to their sensitivity to the cytostatic activity of IFN-gamma; the lower levels of cytostasis seen with the IFN-gamma-resistant MC6A target was the result of IFN-gamma increasing the sensitivity of this target to TNF. Antibodies to IFN-gamma were able to neutralize the majority of the cytostatic activity of the supernatants on both targets, consistent with the role demonstrated for this lymphokine.     

Factors associated with and predictive of persistence of donor-specific antibody after treatment with plasmapheresis and intravenous immunoglobulin

Antibody to donor HLA antigens is a significant barrier to both access to and outcome of allogeneic transplants. Many attempts have been made to desensitize patients with HLA-specific antibody, but the most effective and durable have been treatment with high-dose pooled human intravenous immunoglobulin (IVIg) and a combination of plasmapheresis and low-dose IVIg. Despite the success of these treatments, low levels of donor-specific antibody (DSA) persist in some patients. We examined factors that may be related to and used to predict the elimination of DSA. The most significant associations have been strength of antibody at initiation of treatment and antibody specificity, although other factors revealed a trend toward association. We demonstrate how the types of data generated here can be used to predict elimination or persistence of DSA.     

Telomere lengths of translocation-associated and nontranslocation-associated sarcomas differ dramatically

Sarcomas can be divided into those with specific translocations displaying monotonous cytomorphology, and those with complex karyotypes and marked cellular pleomorphism. Telomeres contain terminal DNA sequence repeats that maintain chromosomal stability. Telomeres shorten with cell division and may become dysfunctional leading to chromosomal instability. Using a fluorescence in situ hybridization/immunofluorescence method to assess telomere lengths in archival tissues we analyzed these two types of sarcomas using paraffin-embedded primary tumor specimens. Tissues from nine sarcomas with characteristic translocations (two synovial sarcomas, two alveolar rhabdomyosarcomas, two desmoplastic round cell tumors, and one each of infantile fibrosarcoma, myxoid liposarcoma, cellular congenital mesoblastic nephroma) and nine without (four malignant fibrous histiocytomas, two leiomyosarcomas, one pleomorphic rhabdomyosarcoma, one dedifferentiated chondrosarcoma, and one malignant peripheral nerve sheath tumor) were analyzed. In all (nine of nine) cases with specific translocations, which generally have few karyotypic abnormalities, telomere lengths were similar to or reduced compared to surrounding nonneoplastic tissues. In contrast, telomeres in cases lacking specific translocations, which generally contain complex karyotypes, were often found to be dramatically lengthened and heterogeneous. In addition to markedly elongated telomeres, seven of nine (78%) complex cases exhibited large brightly stained regions corresponding to a specific type of promyelocytic leukemia nuclear body found in immortalized cells that maintain telomeres in a telomerase-independent manner [alternative lengthening of telomeres (ALT) pathway]. This phenotype is unlike that of epithelial neoplasms that typically display complex karyotypes with abnormally short telomeres maintained by the enzyme telomerase. The discovery of heterogeneous telomere lengths and evidence of the ALT pathway in the majority of sarcomas with complex karyotypes supports the existence of a telomere maintenance pathway incapable of full karyotypic stabilization in pleomorphic sarcomas. These findings provide additional molecular-genetic evidence supporting the dichotomous grouping of sarcomas into those with characteristic signature translocations without extensive additional karyotypic abnormalities, and those without such signature translocations that typically display very complex karyotypes, and point to telomere dysfunction as a plausible contributor to the chromosomal aberrations found in complex sarcomas.