RESUMEN

BACKGROUND: Dentine hypersensitivity is a common problem attributed by patent dentinal tubules. Ingredients incorporated in toothpastes aim to occlude patent dentinal tubules to minimize the dentine hypersensitivity. However, frequent consumption of acidic soft drinks may reverse the dentinal tubules' occlusion. In this in vitro study, the efficacy of dentinal tubules occluded by commercially available toothpastes to withstand different durations of an acidic soft drink challenge was investigated. METHODS: One hundred and twenty dentine discs were divided into three groups. The discs from each group were brushed with toothpaste containing bioactive glass, arginine and control toothpaste. Each group was then divided into four subgroups and exposed to acidic soft drink over four different time durations. RESULTS: The scoring and the percentage of occluded dentinal tubules by Novamin-containing toothpaste was significantly better compared with arginine or the control toothpaste. Acidic soft drink challenge reduced the extent of dentinal tubules occlusion along with time. Dentinal tubules occluded by Novamin-containing toothpaste withstand the acidic challenge comparatively for a longer period. CONCLUSIONS: The findings demonstrated that occlusion of dentinal tubules is more efficient by the bioactive glass-containing toothpaste and thus may contribute to its better resistance to acidic soft drink challenge.

Asunto(s)

RESUMEN

OBJECTIVE: A study was conducted to assess the bioequivalence of two limaprost alfadex 5 microg tablets, a moisture-resistant tablet (dextran formulation) and a standard tablet (lactose formulation). MATERIALS AND METHODS: The clinical investigation was designed as a randomized, open-labeled, two-part, two-treatment, two-period crossover study, in 120 healthy male volunteers. One tablet of either formulation was administered with 200 ml of water after 10-hour overnight fast. After dosing, serial blood samples were collected for a period of 6 hours. Plasma harvested from blood was analyzed for limaprost by a validated LC/MS/MS method. The peak plasma concentration (Cmax) values and time associated with the maximal concentration (tmax) were obtained from the observed data. The elimination rate constant (lambda z) was obtained as the slope of the linear regression of the log-transformed concentration values vs. time data in the terminal phase, and the elimination half-life (t1/2) was calculated as 0.693/lambda z. The area under the curve to the last measurable point (AUC0-t) was estimated by the linear trapezoidal rule. The analysis of variance (ANOVA) was carried out using log-transformed AUC0-t, AUC0-A yen and Cmax and untransformed tmax, and 90% confidence intervals for AUC0-t and Cmax were calculated. If the 90% confidence intervals (CI) for both AUC0-t and Cmax fell fully within the interval 80 - 125%, the bioequivalence of the two formulations was established. RESULTS: The means of AUC0-t were 0.779 vs. 0.754 pg x h/ml (test vs. reference), and the means of the Cmax were 1.26 vs. 1.12 pg/ml (test vs. reference). The geometric mean ratios of the test formulation to reference formulation for AUC0-t and Cmax were 104.0 and 112.4%, respectively, and the 90% CI for AUC0-t and Cmax were 100.7 - 107.4% and 105.6 - 119.6%, respectively. Both 90% CI for AUC0-t and Cmax fell within the Ministry of Health, Labour and Welfare of Japan accepted bioequivalence range of 80 - 125%. CONCLUSIONS: Based on the results, the moisture-resistant tablet was determined to be bioequivalent to the standard tablet.

Asunto(s)

RESUMEN

We performed optical-pump terahertz-probe measurements of a Mott insulator YTiO(3) and a band semiconductor Si using a laser diode (1.47 eV) and a femtosecond-pulse laser (1.55 eV). Both samples possess long energy-relaxation times (1.5 ms for YTiO(3) and 15 µs for Si); therefore, it is possible to extract terahertz complex conductivities of photoinduced carriers under equilibrium. We observed highly contrasting behaviour-Drude conductivity in Si and localized conductivity possibly obeying the Jonscher law in YTiO(3). The carrier number at the highest carrier-concentration layer in YTiO(3) is estimated to be 0.015 per Ti site. Anisotropic conductivity of YTiO(3) is determined. Our study indicates that localized carriers might play an important role in the incipient formation of photoinduced metallic phases in Mott insulators. In addition, this study shows that the transfer-matrix method is effective for extracting an optical constant of a sample with a spatially inhomogeneous carrier distribution.

RESUMEN

In this cross-sectional study, we investigated the effect of daily walking steps on ultrasound parameters of the calcaneus in elderly Japanese women. The subjects were 143 community-dwelling elderly women aged 61-87 years (mean age 71.4+/-5.5 years). The speed of sound (SOS), broadband ultrasound attenuation (BUA) and the stiffness index (Stiffness) of the calcaneus were measured. Walking steps were recorded using a pedometer for 7 consecutive days as an outcome measure of physical activity. In univariate analyses, steps/day significantly decreased with aging. SOS, BUA and Stiffness showed negative correlations with age and positive correlations with weight. Linear relationships were not seen between any of the ultrasound parameters and daily walking steps. Then, the ultrasound parameters were adjusted for age and/or weight using multiple regression models, and the relationships between the adjusted ultrasound measurements and walking steps were examined using quadratic regression models. Walking activity up to approximately 12,000 steps/day was positively associated with the adjusted ultrasound measurements, above which additional walking steps had no positive effect. We conclude that daily walking steps may be suitable for evaluating the relationship between ultrasound parameters and physical activity in elderly women, but further research is needed to confirm the effect of daily walking steps on the rate of bone loss.

Asunto(s)

RESUMEN

Late positive ERP components elicited by omitted somatosensory stimuli in passive paradigm (passive MSPP) and in active time-estimation paradigm (active MSPP) were studied in healthy subjects with single-trial analysis and conventional averages. The active MSPP was also compared with P3 component elicited by somatosensory target stimuli (target P3). Single-trial analysis showed clearly discernible passive MSPP in response to omitted stimuli of the median nerve, whereas passive MSPP was hardly detected in response to omitted stimuli of the index finger. The subjects might pay passive attention to absence of somatosensory stimuli together with absence of the thumb muscle twitches. Single-trial analysis revealed a significantly greater latency fluctuation in passive MSPP than in active MSPP. The active MSPP showed a greater latency fluctuation than the target P3. The active MSPP showed a significantly longer latency and a smaller amplitude than the target P3 in conventional averages. Topography of active MSPP showed a symmetric central-parietal maximal distribution similar to that of target P3.

Asunto(s)

RESUMEN

Autonomic neuropathy, especially sympathicopathy, a life-threatening complication of diabetes mellitus, has been difficult to evaluate, and remains undetermined. We studied the thermographic patterns of 62 patients (50-69 years old), revealing the vasodilated activities of one leg by immersing the other leg in a warm water bath, for the detection of sympathetic neuropathy, using Thermoviewer MDJTG-MD. The normal pattern shows an increase in skin temperature, while the flat pattern shows no rise or even a paradoxical decrease. The latter had a significantly longer duration of diabetes and poor blood sugar control. The thermographic pattern is closely related to microangiopathy, R-R interval variation and motor nerve conduction velocity. However, R-R interval variation is often abnormal in patients with normal thermographic patterns, showing vasosympathetic abnormalities appearing far later in the development of diabetic neuropathy. The flat pattern develops slowly after at least several years of poor blood sugar control. Change in the pattern is also gradual and slow. The reproducibility of the pattern is excellent and requires relatively simple and noninvasive techniques. Thermography is one of the most reliable, reproducible and noninvasive indexes for finding and following diabetic sympathetic abnormalities.

Asunto(s)

Asunto(s)

Asunto(s)

RESUMEN

General pharmacological properties of enflurane (E) and halothane (H) were investigated. Maximum blood concentrations of both drugs reached 30 min after inhalation. E showed lower maximum blood concentration, initial velocity of uptake and shorter half life than H. Neither drug had any effect on neuromuscular junction, but E increased N-M effect of succinylcholine. Both drugs decreased tension of uterine and intestine muscles. Poly- and monosynaptic reflexes were inhibited more by H. ED50's of E and H for intestine muscles. Poly- and monosynaptic reflexes were inhibited more by H. ED50's of E and H for righting reflux were 1.25 and 1.40%, respectively. Tonic and clonic convulsions and death induced by electric shock were inhibited more by E. Almost equal anticonvulsive potency was observed for chemoshocks. Death due to electric and chemoshock was remarkably inhibited by both drugs. Spontaneous EEG was altered in a different manner, although flattened with spikes at 4% concentration of both drugs. E altered rhythmicity of recruiting response and both drugs inhibited this response. H inhibited more remarkably the augmenting response and E inhibited the arousal response. E increased negative potentials of the primary response evoked by sensory stimulation, while H decreased these potentials. Both drugs completely inhibited the secondary response.

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)