GENDER DIFFERENCES IN THE RELATIONSHIP BETWEEN QUADRICEPS MVIC AND HAMSTRING TO QUADRICEPS RATIO

No previous research has evaluated the relationship between degree of Q activation and its’ effect on H:Q ratio, despite the fact that Q dominance and low H:Q ratios are thought to increase the risk of H and ACL injury (Baratta et al., 1988; Hewitt et al., 2001). Compared to males, females may be at greater risk, due to higher Q co-activation (Colliander and Tesch, 1989; White et al., 2003). The purpose of this study was to evaluate gender differences in the relationship between Q activation and it’s effect on H:Q ratios

ELECTROMYOGRAPHICAL ANALYSIS OF HAMSTRING RESISTANCE TRAINING EXERCISES

This study evaluated the EMG activity of the hamstring and quadriceps muscle groups during resistance training exercises commonly used for training the hamstrings. Subjects included 34 collegiate athletes. Hamstring and quadriceps MVIC and 6 repetition maximum loads were determined. Data were collected 72 hours later, during the performance of 6 randomly ordered exercises, including back squats, seated leg curls, stiff leg dead lifts, single leg dead lifts, good mornings, and “Russian curls.” Data were analyzed using RMS values normalized to MVIC. A one way repeated measures ANOVA revealed that significant differences existed between several exercises. Additionally, the ratio of hamstring to quadriceps co-activation was significantly different between all exercises

Impaired Nuclear Nrf2 Translocation Undermines the Oxidative Stress Response in Friedreich Ataxia

BACKGROUND: Friedreich ataxia originates from a decrease in mitochondrial frataxin, which causes the death of a subset of neurons. The biochemical hallmarks of the disease include low activity of the iron sulfur cluster-containing proteins (ISP) and impairment of antioxidant defense mechanisms that may play a major role in disease progression. METHODOLOGY/PRINCIPAL FINDINGS: We thus investigated signaling pathways involved in antioxidant defense mechanisms. We showed that cultured fibroblasts from patients with Friedreich ataxia exhibited hypersensitivity to oxidative insults because of an impairment in the Nrf2 signaling pathway, which led to faulty induction of antioxidant enzymes. This impairment originated from previously reported actin remodeling by hydrogen peroxide. CONCLUSIONS/SIGNIFICANCE: Thus, the defective machinery for ISP synthesis by causing mitochondrial iron dysmetabolism increases hydrogen peroxide production that accounts for the increased susceptibility to oxidative stress

Vitamin D3 inhibits p38 MAPK and senescence-associated inflammatory mediator secretion by senescent fibroblasts that impacts immune responses during ageing.

Vitamin D3 replacement in older insufficient adults significantly improves their antigen-specific varicella zoster virus (VZV) cutaneous immunity. However, the mechanisms involved in this enhancement of cutaneous immunity are not known. Here, we show for the first time that vitamin D3 blocks the senescence-associated secretory phenotype (SASP) production by senescent fibroblasts by partially inhibiting the p38 MAPK pathway. Furthermore, transcriptomic analysis of skin biopsies from older subjects after vitamin D3 supplementation shows that vitamin D3 inhibits the same inflammatory pathways in response to saline as the specific p38 inhibitor, losmapimod, which also enhances immunity in the skin of older subjects. Vitamin D3 supplementation therefore may enhance immunity during ageing in part by blocking p38 MAPK signalling and in turn inhibit SASP production from senescent cells in vivo

Long-term follow-up of residual masses after chemotherapy in patients with non-seminomatous germ cell tumours

This retrospective study was undertaken to determine the outcome of patients with non-seminomatous germ cell tumour who achieved a serological complete response but who had residual radiologic abnormalities upon completion of primary platinum-based chemotherapy. This was an analysis of 76 consecutive patients treated at Mount Vernon Hospital between 1983 and 1997. The patients were placed into two groups based upon whether they had surgical resection (surgery group, 48 patients) or observation (observation group, 28 patients) of residual radiologic masses on completion of initial chemotherapy (to enter the surgery group, complete surgical resection must have been achieved). The primary end-points were progression-free and overall survival. The percentage of patients alive with median follow-up 66 months was 90% for the surgery group and 80% for the observation group (P= 0.53, not significant). The percentage of patients continuously disease-free was 70% in the surgery group and 80% in the observation group (P= 0.31, not significant). In the small sub-group of patients with differentiated teratoma (TD) in the primary lesion who were observed, there was no excess risk of relapse or death. Patients who achieve a serological complete response after primary chemotherapy, but are left with ≤ 2 cm radiological masses that are not cystic and have responded, can be safely observed with diligent follow-up. © 2000 Cancer ResearchCampaig

Sinnvoller Einsatz von Tumormarkern

Tumor markers refer to all detectable and measurable analytes which are able to indicate a solid tumor or contribute to its characterization or judgment concerning tumor spread and therapy efficacy. Among the markers, humoral circulating tumor substances, such as precursors of normal antigens, ectopically produced hormones or enzymes, ontogenetic old reactivated antigens, hybridoma-defined mucins and cytokeratins are of special interest. Up to now, no tumor specific biomarker has been detected, all markers known so far are physiological components of blood; thus, their diagnostic capacity is more related to quantity than to quality. The tumor marker concentration depends on the tumor blood supply and reflects tumor mass and tumor spread as a sum of marker expression, synthesis, release, the catabolism of the organism, as well as the marker excretion. Changes in biomarker levels without correlation to tumor load can be due to impairment of the liver and kidney function or due to invasive diagnostic methods (endoscopy, biopsy, ureteral catheter) or due to acute reactions on treatment (surgery, radio-chemotherapy). Due to problems with standardization between assays from different producers measuring the same antigen, interpretation of biomarkers of single measurements, such as PSA (prostate specific antigen), must be performed using assay specific reference ranges and interpretation of serial measurements must be performed using the identical assay. The test result has to be indicated together with the assay used (kit and producer). Among the potential indications for tumor marker determinations, the early detection or screening of a tumor is unrealistic - except PSA in prostate cancer detection. In rare cases, biomarkers can be helpful in tumor localization (HTG (human thyreoglobuline), PSA) and support of primary diagnosis, the knowledge about their prognostic relevance is increasing, the most widely used indication is therapy control and follow-up care in context with medical imaging. Provided that markers are critically selected following the localization of the tumor, that serial determinations are performed using the identical assay and that the clinical question is relevant, tumor markers contribute to a significant degree to diagnosis, prognosis, therapy control and early detection of metastatic or recurrent disease. Especially in the field of diagnostic oncology, the quality of the investigator is significantly linked to the quality of the test result