Impaired functional recovery after stroke in the stroke-prone spontaneously hypertensive rat

<p><b>Background and Purpose:</b> To identify if the stroke-prone spontaneously hypertensive rat (SHRSP) exhibits impaired functional recovery after stroke compared with its normotensive reference strain, the Wistar Kyoto rat (WKY).</p> <p><b>Methods:</b> In study 1, a 2-mm distal middle cerebral artery occlusion (middle cerebral artery occlusion) was performed in both strains and recovery assessed using a 33-point neurological score. Because SHRSPs displayed much larger infarcts than WKYs, study 2 and study 3 involved extending the length of middle cerebral artery (MCA) occlusion in the WKY to increase the volume and distribution of infarction to comparable levels with SHRSP. Animals were assessed with the neurological score, tapered beam walk, and cylinder tests.</p> <p><b>Results:</b> In study 1, infarct volume (expressed as a percent of contralateral hemisphere) was WKY 13.1&#177;3% and SHRSP 19.8&#177;1%. Initial neurological deficit was greater (WKY 25&#177;1, SHRSP 22&#177;1, out of a possible 33) and subsequent recovery was poorer in SHRSP. In studies 2 and 3, infarct volume and distribution (study 2, WKY 21.8&#177;1.3%, SHRSP 22.9&#177;3%; study 3, WKY 17.2&#177;2%, SHRSP 16.5&#177;3%) and initial neurological deficit at 2 hours after middle cerebral artery occlusion (study 2 WKY 23&#177;1, SHRSP 22&#177;2; study 3 WKY 25&#177;1 and SHRSP 23&#177;1; mean&#177;SEM) were comparable between strains. However, whereas WKY recovered toward normal scores, SHRSP scored significantly lower 2 weeks (study 2) and 4 weeks (study 3) after middle cerebral artery occlusion. Beam walk data revealed long-term impairment in SHRSP contralateral limb use, compared with WKY, at days 3, 7, and 28 (P&#60;0.05).</p> <p><b>Conclusions:</b> SHRSP exhibit impaired functional recovery after stroke compared with WKY.</p

Differential effects of 17beta-estradiol upon stroke damage in stroke prone and normotensive rats

We previously reported that during pro-estrus (high endogenous estrogen levels), brain damage after middle cerebral artery occlusion (MCAO) was reduced in stroke-prone spontaneously hypertensive rats (SHRSP) but not in normotensive Wistar Kyoto rat (WKY). In the present study, we examined the effect of exogenous estrogen on brain damage after MCAO in SHRSP and WKY. A 17beta-estradiol (0.025mg or 0.25mg, 21 day release) or matching placebo pellet was implanted into ovariectomized WKY and SHRSP (3 to 4 months old) who then underwent distal diathermy-induced MCAO 2 weeks later. Plasma 17beta-estradiol levels for placebo and 17beta-estradiol groups were as follows: WKY 0.025 mg 16.4 plusminus 8.5 (pg/mL, mean plusminus SD) and 25.85 plusminus 12.6; WKY 0.25 mg 18.2 plusminus 9.0 and 69.8 plusminus 27.4; SHRSP 0.25 mg 20.7 plusminus 8.8 and 81.0 plusminus 16.9. In SHRSP, infarct volumes at 24 hours after MCAO were similar in placebo and 17beta-estradiol groups: SHRSP 0.025 mg 126.7 plusminus 15.3 mm3 (n = 6) and 114.0 plusminus 14.1 mm3 (n = 8) (not significant); SHRSP 0.25 mg 113.5 plusminus 22.3 mm3 (n = 8) and 129.7 plusminus 26.2 mm3 (n = 7) (not significant), respectively. In WKY, 17beta-estradiol significantly increased infarct volume by 65% with 0.025mg dose [36.1 plusminus 20.7 mm3 (n = 8) and 59.7 plusminus 19.3 mm3 (n = 8) (P = 0.033, unpaired t-test)] and by 96% with 0.25 mg dose [55.9 plusminus 36.4 mm3 (n = 8) and 109.7 plusminus 6.7 mm3 (n = 4) (P = 0.017)]. Thus, 17beta-estradiol increased stroke damage in normotensive rats with no significant effect in stroke-prone rats. Despite being contrary to our hypothesis, our findings add substance to the recently reported negative effects of 17beta-estradiol in clinical studies

An MRI-histological study of white matter in stroke-free SHRSP

Hypertension is associated with cerebral small vessel disease (SVD) and with diffuse white matter hyperintensities (WMH) on T&lt;sub&gt;2&lt;/sub&gt;-weighted magnetic resonance imaging (MRI). We tested whether stroke-prone spontaneously hypertensive rats (SHRSP), a model of chronic hypertension, exhibit WMH. Male SHRSP (age 10 months) without stroke symptoms were compared with age-matched male WKY rats. Stroke-prone spontaneously hypertensive rats exhibited no WMH on MRI scans (T&lt;sub&gt;2&lt;/sub&gt;, T&lt;sub&gt;2&lt;/sub&gt;*, diffusion tensor imaging) and no neuropathological lesions. While leptomeningeal arteries exhibited fibrohyaline wall thickening, with decreased smooth muscle actin relative to WKY, deep penetrating arterioles within the caudate nuclei had no vasculopathy. We conclude that WMH are not an obligate feature of stroke-free SHRSP aged up to 10 months

Mutation (variation) databases and registries: a rationale for coordination of efforts

Genomics, epigenetics, population genetics and bioinformatic

Open compared with closed haemorrhoidectomy: meta-analysis of randomized controlled trials

Aims: This review compares the most popular techniques in managing the wounds after excisional haemorrhoidectomy, which are either to lay the wounds open or to close them.\ud Methods Randomized controlled trials were identified from the major electronic databases using the search terms “hemorrhoid*” and “haemorrhoid*.” Duration of operation, pain, length of hospital stay, time off work, time for wound healing, patient satisfaction, continence, manometry findings and complications were assessed. Quantitative meta-analysis was performed as appropriate or possible.\ud Results: Six trials including 686 patients met the inclusion criteria. The median follow-up time ranged from 1.5 to 19.5 months. Quantitative meta-analysis showed that there was no significant difference in cure rates between the two techniques (relative risk, 1.4; 95% CI, 0.86 to 2.2; p=0.191). Open haemor-rhoidectomy was more quickly performed (weighted mean difference, 1.03 min; 95% CI, 0.51 to 1.54; p<0.001). Closed haemorrhoidectomy wounds showed faster healing (weighted mean difference, 1.2 weeks; 95% CI, 0.88 to 1.55; p<0.001). Hospital stay, maximum pain score, total and individual complication rates were not significantly different.\ud Conclusions: Apart from faster wound healing after closed haemorrhoidectomy, open and closed techniques appeared equally effective and safe. However, there were only a few studies which presented information in different ways, and statistical heterogeneity was high.\u