Long-term remodeling of rat pial microcirculation after transient middle cerebral artery occlusion and reperfusion.

OBJECTIVE: The aim of this study was to assess the in vivo structural and functional remodeling of pial arteriolar networks in the ischemic area of rats submitted to transient middle cerebral artery occlusion (MCAO) and different time intervals of reperfusion. METHODS AND RESULTS: Two closed cranial windows were implanted above the left and right parietal cortex to observe pial microcirculation by fluorescence microscopy. The geometric characteristics of pial arteriolar networks, permeability increase, leukocyte adhesion and capillary density were analyzed after 1 h or 1, 7, 14 or 28 days of reperfusion. MCAO and 1-hour reperfusion caused marked microvascular changes in pial networks. The necrotic core was devoid of vessels, while the penumbra area presented a few arterioles, capillaries and venules with severe neuronal damage. Penumbra microvascular permeability and leukocyte adhesion were pronounced. At 7 days of reperfusion, new pial arterioles were organized in anastomotic vessels, overlapping the ischemic core and in penetrating pial arterioles. Vascular remodeling caused different arteriolar rearrangement up to 28 days of reperfusion and animals gradually regained their motor and sensory functions. CONCLUSIONS: Transient MCAO-induced pial-network remodeling is characterized by arteriolar anastomotic arcades. Remodeling mechanisms appear to be accompanied by an increased expression of nitric oxide synthases.

[Hospital day-surgery: comparative evaluation of 3 general anesthesia techniques]. / Day hospital chirurgico: valutazione comparativa di tre tecniche di anestesia generale.

For the voluntary interruption of pregnancy, three anaesthetic techniques have been compared being a random assigned to three groups of 40 patients. Induction of anaesthesia was based on fentanyl 0.005 mg/kg+midazolam 0.2 mg/kg or fentanyl 0.005 mg/kg = propofol 2.5 mg/kg or ketamina 0.5 mg/kg+propofol 2.0 mg/kg. Anaesthesia was maintained delivering in spontaneous-assisted ventilation N2O 70% in O2. In addition to the intraoperative conditions, quality and rapidity of some neurofunctional aspects of the recovery have been evaluated using the Steward Score and the Coin Counting Test respectively. Our data suggest fentanyl-propofol association as the safest one as regards the needs of one-day surgery.

Long-term follow-up evaluation in HCV chronic hepatitis treated with alpha-2b interferon. A comparison of two protocols.

In a long-term study (27 months) of patients affected by C-virus active hepatitis we have evaluated the effect of decreasing the dose of interferon by 50% and by 75% with respect to the initial efficacious dose (6 MU tiw). Sixty patients received recombinant interferon alpha-2b(r-IFN- alpha-2b) 6 MU tiw for two months followed by 3 MU for seven months (Group A), and 60 patients received r-IFN alpha-2b 6 MU tiw for two months followed by 1.5 MU for seven months (Group B). Three patients in group B failed to return to follow-up and were not considered in subsequent evaluations. Side effects such as to cause suspension of treatment occurred only during the first two months of the study at 6 MU of interferon (3 patients in group A and 6 in group B). During the two months at 6 MU, transaminase values returned to normal in 94 patients (80%). At the end of follow-up, 49 of these patients (42% of the 117 patients examined; or 48.3% in group A and 35.1% in group B) had normal transaminase levels. In no case did the anti-HCV test become negative. On a reduced dose of interferon, relapses occurred more frequently in group B (21.4%) than in group A (9.6%), but the difference was not significant. No difference between responders and non-responders, including relapsing patients, was observed in relation to gender, age, presence of cirrhosis, presence of B-virus antibodies and initial levels of serum transaminase.