Comparison of tissue-cultured bovine endothelial cells from aorta and saphenous vein

Endothelial cells were harvested from bovine aorta and saphenous vein with collagenase and cultured in McCoy's 5a medium (modified GIBCO) supplemented with 10% fetal bovine serum. The cells were subcultured through 17 passages over 4 to 5 months. The growth properties in culture of the two cell types were compared. Morphological comparisons included phase microscopy and scanning and transmission electron microscopy. Comparisons with cultured aortic smooth-muscle cells were made using phase and scanning electron microscopy. No differences were found between cultured endothelial cells from aorta and saphenous vein. Differences in growth patterns in culture clearly distinguished both endothelial cell types from smooth-muscle cells. The presence of Weibel-Palade bodies identified the cells from both sources as endothelial.     

Incidence of retained placenta following induction of parturition with corticoids or prostaglandins

Three trials involving 214 cows were conducted to 1) compare the timing of events during normal parturition with parturition induced with a corticoid or a prostaglandin; 2) determine if synchrony could be improved by injection of steroids either concurrently or after injection of a corticoid or a prostaglandin; 3) determine if the incidence of retained placenta could be reduced; and 4) explore methods of treating retained placenta. The timing of events following induction of parturition was compared with that following a normal parturition in 76 heifers. The time from onset of labor to appearance of the placenta, abdominal press, appearance of feet and expulsion of the fetus did not differ between normal and induced parturition. The time from onset of labor to calf standing was increased from 2.3 +/- 2.0 hours in normal parturition to 5.8 +/- 5.5 hours in cows receiving 10 mg of flumethazone (P<0.05). The interval from onset of labor to calf nursing also tended to be longer (P>0.05<0.01). All control cows expelled fetal membranes by 48 hours after onset of labor, but the proportion expelled by the treatment groups varied from 24 to 76%. None of the treatments used in this study significantly increased placental expulsion over that noted when flumethazone or prostaglandins were used alone. No difference in placental expulsion time was noted in cows douched with nolvasan or injected with 30 cc oxytetracycline. None of the treatments used in the three trials reported in this study improved synchrony of parturition over that noted in the cows receiving only an injection of flumethazone or prostaglandins.     

ParA encoded on chromosome II of Deinococcus radiodurans binds to nucleoid and inhibits cell division in Escherichia coli

Bacterial genome segregation and cell division has been studied mostly in bacteria harbouring single circular chromosome and low-copy plasmids. Deinococcus radiodurans, a radiation-resistant bacterium, harbours multipartite genome system. Chromosome I encodes majority of the functions required for normal growth while other replicons encode mostly the proteins involved in secondary functions. Here, we report the characterization of putative P-loop ATPase (ParA2) encoded on chromosome II of D. radiodurans. Recombinant ParA2 was found to be a DNA-binding ATPase. E. coli cells expressing ParA2 showed cell division inhibition and mislocalization of FtsZ-YFP and those expressing ParA2-CFP showed multiple CFP foci formation on the nucleoid. Although, in trans expression of ParA2 failed to complement SlmA loss per se, it could induce unequal cell division in slmAminCDE double mutant. These results suggested that ParA2 is a nucleoid-binding protein, which could inhibits cell division in E. coli by affecting the correct localization of FtsZ and thereby cytokinesis. Helping slmAminCDE mutant to produce minicells, a phenotype associated with mutations in the ‘Min’ proteins, further indicated the possibility of ParA2 regulating cell division by bringing nucleoid compaction at the vicinity of septum growth.     

AT-rich islands in genomic DNA as a novel target for AT-specific DNA-reactive antitumor drugs

Interstrand cross-links at T(A/T)4A sites in cellular DNA are associated with hypercytotoxicity of an anticancer drug, bizelesin. Here we evaluated whether these lethal effects reflect targeting critical genomic regions. An in silico analysis of human sequences showed that T(A/T)4A motifs are on average scarce and scattered. However, significantly higher local motif densities were identified in distinct minisatellite regions (200-1000 base pairs of approximately 85-100% AT), herein referred to as "AT islands." Experimentally detected bizelesin lesions agree with these in silico predictions. Actual bizelesin adducts clustered within the model AT island naked DNA, whereas motif-poor sequences were only sparsely adducted. In cancer cells, bizelesin produced high levels of lesions (approximately 4.7-7.1 lesions/kilobase pair/microM drug) in several prominent AT islands, compared with markedly lower lesion levels in several motif-poor loci and in bulk cellular DNA (approximately 0.8-1.3 and approximately 0.9 lesions/kilobase pair/microM drug, respectively). The identified AT islands exhibit sequence attributes of matrix attachment regions (MARs), domains that organize DNA loops on the nuclear matrix. The computed "MAR potential" and propensity for supercoiling-induced duplex destabilization (both predictive of strong MARs) correlate with the total number of bizelesin binding sites. Hence, MAR-like AT-rich non-coding domains can be regarded as a novel class of critical targets for anticancer drugs.     

A dynamical point process model of auditory nerve spiking in response to complex sounds

In this paper, we develop a dynamical point process model for how complex sounds are represented by neural spiking in auditory nerve fibers. Although many models have been proposed, our point process model is the first to capture elements of spontaneous rate, refractory effects, frequency selectivity, phase locking at low frequencies, and short-term adaptation, all within a compact parametric approach. Using a generalized linear model for the point process conditional intensity, driven by extrinsic covariates, previous spiking, and an input-dependent charging/discharging capacitor model, our approach robustly captures the aforementioned features on datasets taken at the auditory nerve of chinchilla in response to speech inputs. We confirm the goodness of fit of our approach using the Time-Rescaling Theorem for point processes.     

Aerobic training increases the expression of adiponectin receptor genes in the peripheral blood mononuclear cells of young men

Little is known about the effect of exercise training on the expression of adiponectin receptor genes in peripheral blood mononuclear cells (PBMCs). In this study, we investigated the effects of aerobic training on the expression of AdipoR1 and AidpoR2 mRNAs in PBMCs, whole body insulin sensitivity, and circulating adiponectins in men. Thirty young men were randomly assigned to either a control (n=15) or an exercise (n=15) group. Subjects assigned to the exercise group underwent a 12-week jogging and/or running programme on a motor-driven treadmill at an intensity of 60%-75% of the age-based maximum heart rate with duration of 40 minutes per session and a frequency of 5 days per week. Two-way mixed ANOVA with repeated measures was used to test any significant time-by-group interaction effects for the measured variables at p=0.05. We found significant time-by-group interaction effects for waist circumference (p=0.001), VO_2max (p<0.001), fasting insulin (p=0.016), homeostasis model assessment for insulin resistance (HOMA-IR) (p=0.010), area under the curve (AUC) for insulin response during the 75-g oral glucose tolerance test (p=0.002), high-molecular weight (HMW) adiponectin (p=0.016), and the PBMC mRNA levels of AdipoR1 (p<0.001) and AdipoR2 (p=0.001). The exercise group had significantly increased mRNA levels of AdipoR1 and AdipoR2 in PBMCs, along with increased whole body insulin sensitivity and HMW adiponectin, decreased waist circumference, and increased VO_2max compared with the control group. In summary, the current findings suggest that exercise training modulates the expression of AdipoR1 and AdipoR2 mRNAs in PBMCs, implying that manipulation of the expression of these genes could be a potential surrogate for lifestyle intervention-mediated improvements of whole body insulin sensitivity and glucose homeostasis.     

Similar hypotensive responses to resistance exercise with and without blood flow restriction

Low intensity resistance exercise (RE) with blood flow restriction (BFR) has gained attention in the literature due to the beneficial effects on functional and morphological variables, similar to those observed during traditional RE without BFR, while the effects of BFR on post-exercise hypotension remain unclear. The aim of the present study was to compare the blood pressure (BP) response of trained normotensive individuals to RE with and without BFR. In this cross-over randomized trial, eight male subjects (23.8 ± 4 years, 74 ± 3 kg, 174 ± 4 cm) completed two exercise protocols: traditional RE (3 x 10 repetitions at 70% one-repetition maximum [1-RM]) and low intensity RE (3 x 15 repetitions at 20% 1-RM) with BFR. Blood pressure measurements were performed after 15 min of seated rest (0), immediately after and 10 min, 20 min, 30 min, 40 min, 50 min and 60 min after the experimental sessions. Similar hypotensive effects for systolic BP (SBP) were observed for both protocols (P < 0.05) after exercise, with no differences between groups (P > 0.05) and no statistically significant difference for diastolic BP (P > 0.05). These results suggest that in normotensive trained individuals, both traditional RE and RE with BFR induce hypotension for SBP, which is important to prevent cardiovascular disturbances.