Evaluations on the R Wave in asymptomatic subjects: a preliminary report

This preliminary cross-sectional survey on the R wave of the 12-lead electrocardiogram (ECG) was undertaken to evaluate the normal R wave duration and amplitude of the young adult Nigerian from Jos; to ascertain significant correlation coefficients for R wave duration and amplitude, age and anthropometric measurements and to derive prediction equations. The study population consisted of one hundred and nine (109) subjects aged nineteen to thirty years (mean age 21.7 years). The range for the mean R wave duration was 0.022 ± 0.006 second in V1 to 0.315 ± 0.021 second in V5. The range for the mean R wave amplitude was 0.196 ± 0.103 mV in aVL to 1.078 ± 0.515 mV in V4. Significant inverse correlation was found between R wave duration and: age, height and systolic blood pressure. Significant inverse correlation was found between R wave amplitude and: age, height and systolic blood pressure. Significant correlation was found between R wave amplitude and: height, systolic blood pressure, diastolic blood pressure and chest circumference. Significant correlation was found between R wave duration and weight, diastolic blood pressure and chest circumference. Prediction equations were derived for the mean R wave duration and: age, systolic blood pressure, height and diastolic blood pressure. Prediction equations were derived for R wave amplitude and: height, age, systolic blood pressure and diastolic blood pressure. The study has estimated the mean values for the R wave duration and amplitude in the 12-lead ECG as well as the normal range. It has also documented some derived predictable equations. The results can provide invaluable guidance about the interpretation of normal R wave duration and amplitude in this setting in particular and in Nigeria at large. Nigerian Journal of Health and Biomedical Sciences Vol. 7 (1) 2008 pp. 7-1

Evaluation of antioxidant and antibacterial activities of the stems of Flammulina velutipes and Hypsizygus tessellatus (white and brown var.) extracted with different solvents

Mushrooms are rich in pharmacologically-important phytochemicals with reported medicinal values. In this study, the antibacterial activity of Flammulina velutipes (Enoki), Hypsizygus tessellatus (brown (Buna shimeji) and white (Bunapi shimeji) variants) stem extracts prepared with different solvents (water, methanol, acetone, and ethyl acetate) was investigated against Escherichia coli (E. coli ATCC 25922), Serratia marscenscens (S. marscenscens ATCC14756), Bacillus subtilis (B. subtilis ATCC 23857), and Staphylococcus aureus (S. aureus ATCC 25923). Their antioxidant activities were evaluated using radical scavenging assays of 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydrogen peroxide (H2O2) and ferric reducing power (FRP). The water extracts of Enoki, Buna shimeji, and Bunapi shimeji showed bacterial growth inhibition in a concentration-dependent manner. From the obtained results, all the Enoki extracts showed a significant inhibition of the gram positive bacterial species (E. coli and S. marcescens > 68%) and a reduced inhibition of the gram negative bacterial species (B. subtilis and S. aureus < 45%, p < 0.05) after 24 h of incubation, while water extracts of Buna shimeji showed a significantly lower bacterial growth inhibition (< 60%) against all the studied bacteria. Bunapi shimeji extract inhibited S. marscenscens, E. coli, B. subtilis, and S. aureus by 54, 67, 46, and 44%, respectively. Methanol, acetone and ethyl acetate extracts showed significantly lower antibacterial activities (p < 0.05) compared to water extracts. Similarly, water extracts of Enoki, Bunapi shimeji and Buna shimeji showed significant antioxidant activities using DPPH (67.37 ± 0.01, 66.30 ± 0.18 and 42.44 ± 0.18%, respectively), hydrogen peroxide (67.87 ± 0.000, 45.52 ± 0.160 and 52.08 ± 0.000% respectively), and FRP (0.891 ± 0.001, 0.413 ± 0.001 and 0.491 ± 0.001, respectively) at the concentration of 1 mg/mL, compared to their respective methanol, acetone and ethyl acetate fractions. Upon LC-MS analysis of the most potent fraction (Enoki water extract), several phenolic compounds were identified, of which chromogenic acid, Methyl-5-O-caffeoylquinate, Kukoamine A, Kushenol K, Methyl Kushenol C, Glabrol, Sanggenon J, Corylin, and Moracenin C were confirmed. The antioxidant activities of the water extracts of Enoki, Buna shimeji and Bunapi shimeji correlated with their total phenolic and flavonoid contents, which were (166.56 ± 1.50, 108.13 ± 0.32 and 116.71 ± 0.01 µg gallic acid equivalent (GAE)/mg, respectively) and (96.33 ± 0.03, 82.18 ± 0.20 and 91.37 ± 0.15 µg quercetin equivalent (QE)/mg, respectively). Collectively, the study results have shown the studied mushrooms as potential natural sources of pharmacological agent