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We have studied the in vitro transfection of a plasmid DNA with thelacZgene to HeLa-S3 cells and hemolysis in a red blood cell (RBC) suspension under pulsed ultrasound with duty cycles?of 10, 20 and 30% using a digital sonifier at a frequency of 20 kHz and an intensity of 6.2 W/cm2 on the surface of a horn tip. Cultured HeLa-S3 cells in suspension were exposed to pulsed ultrasound for an apparent exposure timet' from 0 to 60 s. HeLa-S3 viability decreased as a single exponential function of the total exposure timet=?t' with a common time constantt=3.8 s for three duty cycles. Transfection was evaluated by counting the number of ß-galactosidase(ß-Gal)-positive cells relative to the total number of cells. Pulsed ultrasound provided an enhanced transfer of the ß-Gal plasmid to HeLa-S3 cells, 3.4-fold as compared with that in the case of the control. The optimal transfection efficiencies were 0.75, 0.80 and 0.74% neart=twith?=10, 20 and 30%, respectively. The number ratio of ß-Gal-positive cells to the surviving cells after exposure increased witht' according to a modified logistic equation. The degree of hemolysis also increased exponentially witht' at a time constantt'=t0/?for the RBC suspension in physiological saline at a hematocrit concentration of 0.5% witht0=0.9 s. Thus the total exposure time for the optimal transfection efficiency wast, that is, nearly four times oft0. Hemolysis in the RBC suspension may be a useful model for determining optimal transfection by pulsed ultrasound of various duty cycles. [ABSTRACT FROM AUTHOR]

In patients with severe hypertension, chronic heart failure or a history of stroke, the lower limit of autoregulation of cerebral blood flow (CBF) is shifted to higher levels of blood pressure (BP) than those observed in healthy subjects. The aim of pharmacotherapy for hypertensive patients with an impaired autoregulation of CBF should be to reduce BP while preserving an appropriate CBF. In the present study, 16 hypertensive patients who had had an episode of stroke more than 4 weeks previously were administered the angiotensin II (AT1) receptor antagonist losartan at daily doses of 25-100?mg for 4 weeks. Systolic and diastolic blood pressures were recorded for 24?h using an ambulatory BP monitoring system. CBF in both hemispheres of the cerebrum and cerebellum was quantified using single photon emission tomography with N-isopropyl-p-[123I]iodoamphetamine. At baseline, CBF was 29.7±6.7?ml/min/100?g in the cerebrum and 31.5±7.5?ml/min/100?g in the cerebellum. At the end of treatment, BP was lower, while CBF increased by 7.7%in the cerebrum, and remained at the baseline level in the cerebellum. Thus, CBF was preserved despite the reduction in BP. We consider the use of losartan is advantageous for hypertensive patients with a history of stroke in whom autoregulation of CBF is potentially impaired.Journal of Human Hypertension (2004) 18, 693-699. doi:10.1038/sj.jhh.1001735 Published online 6 May 2004 [ABSTRACT FROM AUTHOR]

Little is known about the ecology of insect species in the hyporheic zone of rivers, despite its importance in understanding how species survive in specialized habitats. We report on the life history and trophic characteristics of the hyporheic stonefly species Alloperla ishikariana Kohno, 1953 (Order: Plecoptera, Family: Chloroperlidae) in a gravel-bed river in northern Japan, using year-round sampling of both benthic and hyporheic larvae, as well as flying adults in the riparian zone. Adults emerged between May and August, and the larval cohort structure consisted of three sized groups with some sex dimorphism in their body size, with an average growth rate of 0.0043 mg/day. Diet analyses based on C and N stable isotope ratios indicated minimal ontogenetic diet shifts. In contrast, the temporal diet shift was more apparent with higher dependence on Oligochaeta in winter, with an increasing dependence on Chironomidae in spring and early summer. Other insect taxa, namely, Leuctridae and small-sized Lepidostoma, demonstrated a high to moderate affinity for the hyporheic zone. Alloperla ishikariana spent most of its larval stage in the hyporheic zone. With adults living from 7 to 10 days, A. ishikariana completes a life span of approximately 3 years with its larval stage in the dark. [ABSTRACT FROM AUTHOR]

Improving the quality of ulcer healing (QOUH) is one of the valid methods of prevention of relapse of gastric ulcers. We investigated the effect of lafutidine on the QOUH of gastric ulcer compared with famotidine in a randomized, multi-centre controlled trial. Consecutive 80 patients with a gastric ulcer were randomly assigned to receive twice daily either lafutidine (10 mg) or famotidine (20 mg) for 12 weeks. Esophagogastroduodenoscopy was performed to examine the ulcer healing rate and rate of fl at type ulcer scars using dye-contrast. The gastric ulcer healing rate was 92.1% in the lafutidine group (35/38) and 94.7% in the famotidine group (36/38). The rate of flat-type ulcer scars was significantly higher in the lafutidine group (68.4%, 26/38) than in the famotidine group (42.1%, 16/38) (P = 0.021). In conclusion, the present study demonstrated that lafutidine, as compared to famotidine, yields a signifi cantly superior QOUH in patients with gastric ulcers in the clinical setting. [ABSTRACT FROM AUTHOR]

Background: Crohn's colitis, frequently accompanied by stenosis or narrowing, can be difficult to assess through conventional methods. We evaluated the usefulness of virtual computed tomographic colonography (CTC) for the detection of colonic lesions due to Crohn's disease.Methods: Forty-two lesions in 33 patients with Crohn's disease were examined by CTC and barium enema (BE). Twenty-two patients also were examined by colonoscopy (CS). The visualization ability of CTC was compared with those of the other two methods.Results: In the visualization of elevated lesions, there was no significant difference between CTC and BE (18 of 20, p = 0.487) or between CTC and CS (15 of 16, p = 0.99); however, ulcerative lesions were less often visualized by CTC. However, CTC enabled identification of serious lesions in the colon proximal to the stenosis in nine patients and was superior to BE and CS in terms of its ability to visualize the proximal site of the stenosis (p = 0.003).Conclusion: CTC is clinically useful for the evaluation of Crohn's colitis, especially those with stenotic lesions. [ABSTRACT FROM AUTHOR]

Background: The prevalence of Helicobacter pylori infection in Crohn's disease (CD) patients was investigated to determine whether the presence and severity of gastroduodenal lesions were related to H. pylori infection.Methods: Infection rates were compared between CD group (n = 90) and the control group (n = 525). Correlations between endoscopically detected lesions and H. pylori positive rates were investigated. The relationship between drug therapy and the prevalence of H. pylori infection was also analyzed.Results: H. pylori-positive rate of the 90 CD patients attending our clinic was 16.7%, significantly lower than the rate in healthy controls (40.2%) (P = 0.0001). The involvement of H. pylori infection in the gastroduodenal lesions of CD patients was also examined. The prevalence of gastroduodenal lesions in all CD patients was high, 92.2%. The lesions observed included ulcers, erosion, and "bamboo joint-like lesions" of the stomach, and ulcers, erosion, stenosis, and elevated lesions of the duodenum. None of these lesions were found to be related to H. pylori infection. However, H. pylori infection was found to exacerbate gastric ulcers (P = 0.036). The analysis of a possible relationship between a history of drug therapy and the low prevalence of H. pylori infection in CD patients showed that the prevalence of H. pylori infection was significantly lower in patients who had received antibiotics for 2 weeks or more (P = 0.002).Conclusions: The results suggest that H. pylori infection is essentially unrelated to the gastroduodenal lesions observed in CD. It seems likely, however, that H. pylori infection may exacerbate gastric ulcers and that H. pylori can be eradicated by prolonged use of antibiotics. [ABSTRACT FROM AUTHOR]