Effects of neuromuscular electrical stimulation parameters on specific tension

This study examined the effects of altering surface neuromuscular electrical stimulation (SNMES) parameters on the specific tension of the quadriceps femoris muscle. Seven able-bodied subjects had magnetic resonance images taken of both thighs prior to and immediately after four SNMES protocols to determine the activated muscle cross-sectional area (CSA). The four protocols were: (1) research (RES, 100 Hz, 450 μs, and amplitude set to evoke 75% of maximal voluntary isometric torque, MVIT); (2) pulse duration (PD, 100 Hz, 150 μs, same current as in RES); (3) frequency (FREQ, 25 Hz, 450 μs, and same current as in RES); (4) amplitude (AMP, 100 Hz, 450 μs, and current set to evoke the average of the initial torques of PD and FREQ, 45 ± 9% of MVIT). Reducing the amplitude of the current from 75 to 45% of MVIT did not alter specific tension, 25 ± 8 N/cm², suggesting that the amplitude probably affects torque and the area of activated muscle proportionally. Shortening the pulse duration from 450 to 150 μs caused specific tension to drop from 25 ± 6 to 20 ± 6 N/cm² (P < 0.05), indicating that pulse duration increased torque and the activated CSA disproportionally. Alternatively, reducing the frequency from 100 to 25 Hz decreased specific tension from 25 ± 6 to 17 ± 4 N/cm² (P < 0.05), suggesting that the frequency increased torque without affecting the activated CSA. Clinicians who administer SNMES should be aware of the magnitude of adaptations to a given amplitude, pulse duration, and frequency.     

Integration of antiretroviral treatment within antenatal care in Gauteng Province, South Africa

BACKGROUND: Antenatal clinics are a key entry point into HIV treatment and care, together with interventions to reduce mother-to-child transmission (MTCT). Further evaluation is needed of interventions linking antenatal with antiretroviral (ARV) treatment services and effectiveness of triple-ARV regimens for reducing MTCT in resource-constrained settings. METHODS: Data were gathered from HIV-infected women attending antenatal care from June 2004 to July 2005 at Coronation Women and Children Hospital, South Africa. After a patient record review, interventions were implemented to strengthen service linkages and integrate ARV treatment within antenatal care. Laboratory investigations were streamlined, including CD4 cell count testing at the first antenatal visit. MTCT risk for women initiating ARV treatment is compared with that of women-infant pairs receiving single-dose nevirapine (sd-NVP). RESULTS: In total, 164 pregnant women initiated ARV treatment and 863 received sd-NVP. After changes to service delivery, time-to-treatment initiation was reduced from a median of 56 days to 37 days (P = 0.041). The risk of MTCT for women receiving ARV treatment (5 [4.3%] of 116 women) was lower than for those given sd-NVP (74 [10.7%] of 692 women; P = 0.032). CONCLUSIONS: Strengthening linkages and integrating key components of ARV treatment within antenatal care reduces time-to-treatment initiation. In this setting, among women with a high MTCT risk, triple-ARV regimens are effective in reducing HIV infection in infants.     

Targeting the heme-oxidized nitric oxide receptor for selective vasodilatation of diseased blood vessels

ROS are a risk factor of several cardiovascular disorders and interfere with NO/soluble guanylyl cyclase/cyclic GMP (NO/sGC/cGMP) signaling through scavenging of NO and formation of the strong oxidant peroxynitrite. Increased oxidative stress affects the heme-containing NO receptor sGC by both decreasing its expression levels and impairing NO-induced activation, making vasodilator therapy with NO donors less effective. Here we show in vivo that oxidative stress and related vascular disease states, including human diabetes mellitus, led to an sGC that was indistinguishable from the in vitro oxidized/heme-free enzyme. This sGC variant represents what we believe to be a novel cGMP signaling entity that is unresponsive to NO and prone to degradation. Whereas high-affinity ligands for the unoccupied heme pocket of sGC such as zinc-protoporphyrin IX and the novel NO-independent sGC activator 4-[((4-carboxybutyl){2-[(4-phenethylbenzyl)oxy]phenethyl}amino) methyl [benzoic]acid (BAY 58-2667) stabilized the enzyme, only the latter activated the NO-insensitive sGC variant. Importantly, in isolated cells, in blood vessels, and in vivo, BAY 58-2667 was more effective and potentiated under pathophysiological and oxidative stress conditions. This therapeutic principle preferentially dilates diseased versus normal blood vessels and may have far-reaching implications for the currently investigated clinical use of BAY 58-2667 as a unique diagnostic tool and highly innovative vascular therapy.     

Antioxidant,anti-microbial and antimutagenicity activities of pistachio (Pistachia vera) green hull extract

Antioxidant, anti-microbial and antimutagenicity activities of pistachio (Ahmadaghaei variety) green hull extracts (crude and purified extracts) were studied. At first, different solvents were compared for determining of the best solvent for extraction of phenolic compounds from pistachio green hull. Water and acetonitrile with 49.32 and 6.22 (mg of gallic acid equivalents/g sample) were the best and the worst solvent in the extraction of phenolic compounds, respectively. The antioxidant capacity of crude and purified extracts were assessed through ABTS assay, DPPH assay and β-carotene bleaching (BCB) method. A concentration-dependent antioxidative capacity was verified in ABTS, DPPH assays and BCB method. The anti-microbial capacity was screened against Gram positive and Gram negative bacteria, and fungi. Aqueous and purified extracts inhibited the growth of Gram positive bacteria; Bacillus cereus was the most susceptible one with MIC of 1 mg/mL and 0.5 mg/mL for the crude and purified extracts, respectively. The results of antimutagenicity test showed that phenolic compounds of pistachio green hull have antimutagenicity activity against direct mutagen of 2-nitrofluorene. The results obtained indicate that pistachio green hull may become important as a cheap and noticeable source of compounds with health protective potential and anti-microbial activity.     

Potential testicular toxicity of sodium nitrate in adult rats

Nitrate is a common contaminant in groundwater aquifers. Current study aimed at evaluating the potential testicular toxicity of sodium nitrate in rats. Sodium nitrate was given orally to rats at doses of 50, 100 or 200 mg/kg/day for 60 consecutive days. Sperm count and motility, daily sperm production and testis weight were significantly decreased specially at high doses. Testicular activity of lactate dehydrogenase-X, glucose-6-phosphate dehydrogenase, and acid phosphatase were inhibited in a dose-related manner. Lipid peroxides and hydrogen peroxide production were significantly increased in all treated animals. This was accompanied by inhibition of testicular activities of superoxide dismutase and glutathione peroxidase. Fifty mg/kg of sodium nitrate did not significantly alter catalase or glutathione reductase activity. Glutathione was significantly decreased by sodium nitrate in a dose-related manner. The decrease in sperm count and motility and daily sperm production was confirmed by histopathological studies which indicated chromatolysis, pyknosis and necrosis in spermatocytes. In conclusion, subchronic exposure of rats to sodium nitrate results in testicular toxicity as evidenced by decreased sperm count and motility, daily sperm production and testis weight, inhibited activity of enzyme markers of spermatogenesis and induction of histopathological changes. These effects are attributed, at least partly, to testicular oxidative stress.     

Quality of life assessment in survivors of breast cancer

Aim: The aim was to assess the health-related quality of life (HRQOL) and its temporal variation at first visit and subsequent visits among breast cancer patients. Design and Setting: The prospective study was carried out in Outpatient Department of Radiation Oncology, University Teaching and Tertiary Referral Hospital. Material and Methods: After clearance from the ethical committee and EORTC group, 81 surgically treated female breast cancer patients referred to the Outpatient Department of Radiation Oncology for chemoradiation and hormonal therapy were included in the study after informed written consent, irrespective of the age and stage of disease. The patients were interviewed as per the EORTC QLQ-C30 Questionnaire module at four levels at the first visit and at subsequent follow-up visits at 6, 12, and 24 months, respectively, and are still on follow-up. Statistical Analysis: The data collected were expressed as mean/raw score (RS), standard deviation (SD), and percent mean/scale score expressed on the linear transformation scale, derived as per the calculations and equations of the EORTC QLQ-C30 Scoring Manual. Intragroup comparison (IGC) was done at four levels/visits, a, b, c and d. A P-value of <0.05 was considered significant. Results: The mean age at presentation was 46.6 ± 10.2 years. The study showed that the physical functioning, role functioning, cognitive functioning, emotional functioning, social functioning, global health status, and symptomatology showed statistically significant improvement over time (P < 0.001). Conclusion: The survivors of female breast cancer over the long-term follow-up showed significant improvement and coping mechanisms involved in a majority of HRQOL parameters.     

Calcium mobilization by the plant estrogen ferutinin does not induce blood platelet aggregation

Platelet activation is closely associated with an increase in intracellular Ca(2+) concentration. Various compounds including Ca(2+) ionophores are able to trigger platelet aggregation by increasing intracellular Ca(2+) concentration in platelets. In the present study, we monitored the effect of the phytoestrogen ferutinin, which acts as a Ca(2+) ionophore in human blood platelets; its ionophore-like properties include upregulation of [Ca(2+)](in), activation of fibrinogen receptors and increased fibrinogen binding. Using spectrofluorometry and triple-color flow cytometry, we demonstrate that ferutinin increases [Ca(2+)](in) in both isolated platelets and platelets in whole blood from humans. This effect was almost completely blocked by the Ca(2+) chelator EGTA and was not sensitive to either Gd(3+) or econazole, which inhibit VOC and SOC channels, respectively. Nor was the effect sensitive to thapsigargin, an inhibitor of endoplasmic reticulum Ca(2+) ATPases. Ferutinin stimulated the expression of the active form of the GPIIb-IIIa complex and whole blood platelet aggregation only weakly and had no statistically significant effect on the binding of fibrinogen. These results demonstrate apparently inconsistent effects of ferutinin, which raises intraplatelet Ca(2+) concentration but fails to have an effect on spontaneous blood platelet aggregation. This pattern of responses may be caused by the combination of ferutinin's Ca(2+) ionophoric and estrogenic properties.