Association between physical activity and the prevalence of tumorigenic bacteria in the gut microbiota of Japanese adults: a cross-sectional study.

Escherichia coli harboring polyketide synthase (pks+ E. coli) has been suggested to contribute to colorectal cancer development. Physical activity is strongly associated with lower colorectal cancer risks, but its effects on pks+ E. coli remain unclear. The aim of this study was to investigate the association between pks+ E. coli prevalence and physical activity. A cross-sectional study was conducted on 222 Japanese adults (27-79-years-old, 73.9% female). Triaxial accelerometers were used to measure light-intensity physical activity, moderate-to-vigorous intensity physical activity, the physical activity level, step-count, and time spent inactive. Fecal samples collected from participants were used to determine the prevalence of pks+ E. coli. Multivariate logistic regression analysis and restricted cubic spline curves were used to examine the association between pks+ E. coli prevalence and physical activity. The prevalence of pks+ E. coli was 26.6% (59/222 participants). The adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the highest tertile with reference to the lowest tertile of physical activity variables were as follows: light-intensity physical activity (OR 0.63; 95% CI 0.26-1.5), moderate-to-vigorous intensity physical activity (OR 0.85; 95% CI 0.39-1.87), physical activity level (OR 0.69; 95% CI 0.32-1.51), step-count (OR 0.92; 95% CI 0.42-2.00) and time spent inactive (OR 1.30; 95% CI 0.58-2.93). No significant dose-response relationship was found between all physical activity variables and pks+ E. coli prevalence. Our findings did not suggest that physical activity has beneficial effects on the prevalence of pks+ E. coli. Longitudinal studies targeting a large population are needed to clarify this association.

Effects of Mild Orthostatic Stimulation on Cerebral Pulsatile Hemodynamics.

The augmented cerebral hemodynamic pulsatility could lead to the elevated risk of cerebrovascular disease. To determine the impact of an acute orthostatic challenge on a pulsatile component of cerebral hemodynamics, mild lower body negative pressure (LBNP, -30 mmHg) was applied to 29 men. Middle cerebral artery blood flow velocity (MCAv) was measured by transcranial Doppler technique. Stroke volume (SV) was estimated by the Modelflow method with adjustment by the Doppler ultrasound-measured SV at rest. SV, peak and pulsatile MCAv, and pulsatility index were significantly lower during the LBNP stimulation than those at the baseline (e.g., supine resting) (P < 0.05 for all), whereas mean arterial pressure and mean MCAv remained unchanged. The change in SV with the LBNP stimulation significantly correlated with corresponding changes in peak and pulsatile MCAv (r = 0.617, P < 0.001; r = 0.413, P = 0.026, respectively). These results suggest that pulsatile components of cerebrovascular hemodynamics are dampened during the transient period of orthostatic challenge (as simulated using LBNP) when compared to supine rest, and which is partly due to the modified SV.

Relationship between content of pharmacological components and grade of Japanese Angelica radixes.

AIM OF THE STUDY: Japanese Angelica radix (Angelicaacutiloba Kitagawa radix; Yamato-toki), is classified into one of the three grades: excellent-, middle- and low-grade. Even though herbal doctors and Kampo pharmacists have observed that radix grades correspond to their pharmacological response in clinical experience, these observations has not been documented with supporting scientific evidence in the literature. In the current study, relationship between content of pharmacological components and the grade of radixes was reported. MATERIALS AND METHODS: Pharmacological effect of methanol extracts of excellent- and low-grade radixes was compared using assay of inhibition of acetylcholine-induced contraction in guinea pig ileum. Pharmacological contents of the radix were quantitatively measured by HPLC analysis. RESULTS: Excellent-grade radixes showed lower activity than low-grade radixes on the inhibition assay for ileum contraction. (Z)-Ligustilide content of the excellent-grade radixes was statistically significantly lower than that of other grades of radixes (p-value by Student's t-test: 6.9x10(-4)). A regression equation was obtained from assessing the inhibitory activity of a (Z)-ligustilide standard at various concentrations. Comparison of the inhibitory activity values, which were estimated by the regression equation, and the actual activity values, which were determined using the assay, indicated that ligustilide is the factor that dominantly affects the activity. The ligustilide concentration of hot water extracts of radixes was determined. The concentration in the hot water extracts and the content of the radixes was positively correlated based on a Pearson correlation test. This result suggests that ligustilide extracted by infusion depends on its radix content. CONCLUSIONS: There are differences in (Z)-ligustilide content and its pharmacological activity depending on the grade of Japanese Angelica radix.

Expression of randomly integrated single complete copy transgenes does not vary in Arabidopsis thaliana.

The high variability of transgene expression is frequently observed in independent transgenic lines. Variability of transgene expression has been attributed to several factors, including differences in chromosome position, repeat sequences and copy number. The eukaryotic genome, with a heterogeneous chromatin structure, is not homogeneous for transcriptional activity. Chromatin structure at the site of integration can affect transgene expression; this phenomenon is called the position effect. In this study, we investigated whether position effects confer variability of transgene expression in Arabidopsis thaliana. We analyzed the expression of randomly integrated single 'complete' (intact, non-truncated, non-rearranged) copy transgenes in A. thaliana. Ten independent lines containing single complete copies of the transgene located at different chromosome positions showed very similar levels of transgene expression, and variability of transgene expression was not observed. This result indicates that position effects may not generally be a major cause of variability of transgene expression in A. thaliana.