Effect of Long-Term Estrogen Replacement on Bladder Function in Old Female Rats

The effects of estradiol (E2) on urodynamic parameters were studied with twenty 16-month-old female Wistar rats. They were divided into 4 groups, i.e., Group I: untreated; Groups II and III: treated with E2 for 4 and 8 weeks, respectively; Group IV: treated with a placebo for 8 weeks. After treatment, we measured their plasma E2 levels, and recorded their voiding behavior for 24 h. Cystometry was performed and urodynamic parameters were analyzed. Particularly, bladder capacity as well as voided volume and frequency were surveyed. The results obtained were compared among groups. Levels of bladder capacity in the E2-replaced groups (Groups II, 0.52 ± 0.14 mL and Groups III, 0.58 ± 0.09 mL) were significantly (P < 0.05) higher than in the other groups (Group I, 0.38 ± 0.09 mL and Group IV, 0.40 ± 0.11 mL) respectively. The average voided volume was significantly (P < 0.05) higher in the E2-replaced groups (Groups II, 1.06 ± 0.22 mL and Groups III, 1.01 ± 0.16 mL) than in Group IV (0.79 ± 0.15 mL), respectively. Concerning the number of daily micturition per day, a significant difference (P < 0.05) was observed only between Group III (14.2 ± 2.7) and Group IV (18.8 ± 3.7). This suggests that E2-replacement therapy positively affects bladder function

Effect of Estrogen Replacement Therapy on Bladder Circulation in Old Female Rats

The effect of estradiol (E2) on the urinary bladder of old female rats was investigated by examining the histology and blood flow in the bladders. A total of 20 female Wistar rats aged 16 months were divided into 4 groups: Group I, 5 normal controls; Group II, 5 rats treated with E2 for 4 weeks; Group III, rats treated with E2 for 8 weeks; and Group IV, 5 rats receiving a placebo for 8 weeks. After the treatment, we removed the bladders, then weighed and stained them with hematoxylin and eosin. The muscle content was analyzed with the Elastica-van Gieson method, and the number of blood vessels with the Masson's trichrome method. Blood circulation in the bladders was also measured. The E2-replaced groups showed higher levels than the other groups in terms of blood flow in the bladder (20.6 ± 1.8 mL/min for Group II and 23.4 ± 1.5 mL/min for Group III, both P < 0.05 versus Groups I and IV), muscle content (2.33 ± 0.47 and 3.11 ± 0.48 for Groups II and III, respectively, both P < 0.05 versus Groups I and IV) and bladder weight (185.3 ± 6.2 mg and 193.2 ± 23.5 mg for Groups II and III; Group III showed P < 0.05 versus Groups I and IV). Differences in body weight and number of blood vessels among groups were not significant. We observed an increase in blood circulation, muscle content and weight of the bladder: E2-replacement therapy positively affected bladder functions

Phase Noise Can Induce Stochastic Resonance?

We investigated stochastic resonance (SR) of ac-driven electroconvection (EC) in nematic liquid crystals by employing the phase noise of the ac field. The phase noise smoothly varies the threshold of EC, as the amplitude noise does it. Surprisingly, a kind of phase stochastic resonance (PSR) is discovered in appropriately colored phase noises; thus, it provides nonmonotonic behavior of the threshold in which a peak of the pattern amplitude of EC is found as a function of the phase noise intensity. The colored and white phase noises are discussed for understanding the PSR

Control of stochastic and inverse stochastic resonances in a liquid-crystal electroconvection system using amplitude and phase noises

Abstract Stochastic and inverse stochastic resonances are counterintuitive phenomena, where noise plays a pivotal role in the dynamics of various biological and engineering systems. Even though these resonances have been identified in various systems, a transition between them has never been observed before. The present study demonstrates the presence of both resonances in a liquid crystal electroconvection system using combined amplitude and phase noises, which correspond to colored noises with appropriate cutoff frequencies (i.e., finite correlation times). We established the emergence of both resonances and their transition through systematic control of the electroconvection threshold voltage using these two noise sources. Our numerical simulations were experimentally confirmed and revealed how the output performance of the system could be controlled by combining the intensity and cutoff frequency of the two noises. Furthermore, we suggested the crucial contribution of a usually overlooked additional phase noise to the advancements in various noise-related fields

Dual radioisotopes simultaneous SPECT of 99mTc-tetrofosmin and 123I-BMIPP using a semiconductor detector.

Objective(s): The energy resolution of a cadmium-zinc-telluride (CZT) solid-state semiconductor detector is about 5%, and is superior to the resolution of the conventional Anger type detector which is 10%. Also, the window width of the high-energy part and of the low-energy part of a photo peak window can be changed separately. In this study, we used a semiconductor detector and examined the effects of changing energy window widths for 99mTc and 123 I simultaneous SPECT. Methods: The energy “centerline” for 99mTc was set at 140.5 keV and that for 123I at 159.0 keV. For 99mTc, the “low-energy-window width” was set to values that varied from 3% to 10% of 140.5 keV and the “high-energy-window width” were independently set to values that varied from 3% to 6% of 140.5 keV. For 123I, the “low energy-window-width” varied from 3% to 6% of 159.0 keV and the high-energy-window width from 3% to 10% of 159 keV. In this study we imaged the cardiac phantom, using single or dual radionuclide, changing energy window width, and comparing SPECT counts as well as crosstalk ratio. Results: The contamination to the 123I window from 99mTc (the crosstalk) was only 1% or less with cutoffs of 4% at lower part and 6% at upper part of 159KeV. On the other hand, the crosstalk from 123I photons into the 99mTc window mostly exceeded 20%. Therefore, in order to suppress the rate of contamination to 20% or less, 99mTc window cutoffs were set at 3% in upper part and 7% at lower part of 140.5 KeV. The semiconductor detector improves separation accuracy of the acquisition inherently at dual radionuclide imaging. In, this phantom study we simulated dual radionuclide simultaneous SPECT by 99mTc-tetrofosmin and 123 I-BMIPP. Conclusion: We suggest that dual radionuclide simultaneous SPECT of 99mTc and 123I using a CZT semiconductor detector is possible employing the recommended windows

Dual radioisotopes simultaneous SPECT of 99mTc-tetrofosmin and 123I-BMIPP using a semiconductor detector.

Objective(s): The energy resolution of a cadmium-zinc-telluride (CZT) solid-state semiconductor detector is about 5%, and is superior to the resolution of the conventional Anger type detector which is 10%. Also, the window width of the high-energy part and of the low-energy part of a photo peak window can be changed separately. In this study, we used a semiconductor detector and examined the effects of changing energy window widths for 99mTc and 123 I simultaneous SPECT. Methods: The energy “centerline” for 99mTc was set at 140.5 keV and that for 123I at 159.0 keV. For 99mTc, the “low-energy-window width” was set to values that varied from 3% to 10% of 140.5 keV and the “high-energy-window width” were independently set to values that varied from 3% to 6% of 140.5 keV. For 123I, the “low energy-window-width” varied from 3% to 6% of 159.0 keV and the high-energy-window width from 3% to 10% of 159 keV. In this study we imaged the cardiac phantom, using single or dual radionuclide, changing energy window width, and comparing SPECT counts as well as crosstalk ratio. Results: The contamination to the 123I window from 99mTc (the crosstalk) was only 1% or less with cutoffs of 4% at lower part and 6% at upper part of 159KeV. On the other hand, the crosstalk from 123I photons into the 99mTc window mostly exceeded 20%. Therefore, in order to suppress the rate of contamination to 20% or less, 99mTc window cutoffs were set at 3% in upper part and 7% at lower part of 140.5 KeV. The semiconductor detector improves separation accuracy of the acquisition inherently at dual radionuclide imaging. In, this phantom study we simulated dual radionuclide simultaneous SPECT by 99mTc-tetrofosmin and 123 I-BMIPP. Conclusion: We suggest that dual radionuclide simultaneous SPECT of 99mTc and 123I using a CZT semiconductor detector is possible employing the recommended windows

Optimization of Coronary Attenuation in Coronary Computed Tomography Angiography Using Diluted Contrast Material

Background: The purpose of this study was to evaluate a personalized protocol with diluted contrast material (CM) for coronary computed tomography angiography (CTA). Methods and Results: One hundred patients with suspected coronary artery disease underwent retrospective electrocardiogram-gated coronary CTA on a 256-slice multidetector-row CT scanner. In the diluted CM protocol (n=50), the optimal scan timing and CM dilution rate were determined by the timing bolus scan, with 20% CM dilution (5 ml/s during 10s) being considered suitable to achieve the target arterial attenuation of 350 Hounsfield units (HU). In the body weight (BW)-adjusted protocol (n=50, 222 mg iodine/kg), only the optimal scan timing was determined by the timing bolus scan. The injection rate and volume in the timing bolus scan and real scan were identical between the 2 protocols. We compared the means and variations in coronary attenuation between the 2 protocols. Coronary attenuation (mean +/- SD) in the diluted CM and BW-adjusted protocols was 346.1 +/- 23.9 HU and 298.8 +/- 45.2 HU, respectively. The diluted CM protocol provided significantly higher coronary attenuation and lower variance than did the BW-adjusted protocol (P<0.05, in each). Conclusions: The diluted CM protocol facilitates more uniform attenuation on coronary CIA in comparison with the BW-adjusted protocol

Qualitative and quantitative assessment of adenosine triphosphate stress whole-heart dynamic myocardial perfusion imaging using 256-slice computed tomography.

BACKGROUND: The aim of this study was to investigate the correlation of the qualitative transmural extent of hypoperfusion areas (HPA) using stress dynamic whole-heart computed tomography perfusion (CTP) imaging by 256-slice CT with CTP-derived myocardial blood flow (MBF) for the estimation of the severity of coronary artery stenosis. METHODS AND RESULTS: Eleven patients underwent adenosine triphosphate (0.16 mg/kg/min, 5 min) stress dynamic CTP by 256-slice CT (coverage: 8 cm, 0.27 s/rotation), and 9 of the 11 patients underwent coronary angiography (CAG). Stress dynamic CTP (whole-heart datasets over 30 consecutive heart beats in systole without spatial and temporal gaps) was acquired with prospective ECG gating (effective radiation dose: 10.4 mSv). The extent of HPAs was visually graded using a 3-point score (normal, subendocardial, transmural). MBF (ml/100g/min) was measured by deconvolution. Differences in MBF (mean ± standard error) according to HPA and CAG results were evaluated. In 27 regions (3 major coronary territories in 9 patients), 11 coronary stenoses (> 50% reduction in diameter) were observed. In 353 myocardial segments, HPA was significantly related to MBF (P 70%], 119 ± 69). CONCLUSION: The qualitative transmural extent of HPA using stress whole-heart dynamic CTP imaging by 256-slice CT exhibits a good correlation with quantitative CTP-derived MBF and may aid in assessing the hemodynamic significance of coronary artery disease