A system for continuous digitizing and evaluation of 32 biosignals from all-night sleep leads

In all-night sleep recordings usually 12 to 16 channel electroencephalographs are used to record the electrical activity of the brain. A detailed analysis of EEG sleep activity, however, requires the inclusion of at least 19 electrodes placed according to the international 10-20 system in order to compare the variations of the activities in different brain areas. In addition polygraphic parameters such as ECG, respiration and actogram, to mention just a few, have to be recorded depending on the type of study. Therefore the number of recording channels has to be increased for a complete polygraphic investigation. We developed a 32 channel unit with a personal computer and corresponding hardware interfaces allowing the continuous digitalization of up to 32 bioelectrical signals throughout the whole night (8 hours). The recorded data can be presented graphically and evaluated according to the usual methods such as power spectrum, coherence and periodicity analysis. Additionally the use of algorithms for pattern detection permits automatic analysis of EEG segments regarding particular sleep patterns e.g. sleep spindles and K-complexes.     

TD清洗消毒剂对口腔科器械消毒效果探讨

通过实验室和口腔科临床观察表明:TD清洗消毒剂(氯化磷酸三钠)对金黄色葡萄球菌、绿脓杆菌和枯草杆菌黑色变种的平均杀菌率为100.0％,对口腔科器械消毒无菌率为100％,对被HBsAg阳性血清污染的器械浸泡30分钟转阴率为98.1％。其消毒效果优于新洁尔灭,与戊二醛相同。在口腔科使用两年,未见金属器械有锈斑生成。     

激光光凝治疗黄斑水肿

应用氩绿激光治疗视网膜血管性疾病所致黄斑水肿50例,73只眼。治疗后,有20.5％(15/73)的患眼视力提高2行以上,76.8％(56/73)的患眼视力保持稳定。局部性和/或非囊样黄斑水肿患眼的视力预后较好,水肿易于吸收。弥漫性和/或囊样黄斑水肿患眼的视力预后较差,水肿较难吸收。术前视力可影响预后。对激光光凝治疗本病的疗效、影响因素、激光治疗技术及其机理,也进行了讨论。     

Influence of Polyethylene Glycol Superoxide Dismutase/Catalase on Altered Opioid-induced Pial Artery Dilation after Brain Injury

Background: The current study was designed to investigate the influence of pretreatment with the oxygen radical scavengers polyethylene glycol superoxide dismutase and catalase (SODCAT) on altered opioid-induced pial artery dilation after fluid percussion brain injury (FPI) in the newborn pig. It has been observed previously that brain injury produces pial artery vasoconstriction in the piglet associated with elevated cerebrospinal fluid opioid levels. Furthermore, opioid-induced vasodilation and cyclic guanosine monophosphate production are attenuated following brain injury. Finally, oxygen free radicals have been implicated in the pathogenesis of brain injury.

Methods: Anesthetized piglets equipped with a closed cranial window were connected to a percussion device consisting of a saline-filled cylindrical reservoir with a metal pendulum. Fluid percussion brain injury of moderate severity (1.9-2.3 atm) was produced by allowing the pendulum to strike a piston on the cylinder. Superoxide dismutase-inhibitable nitroblue tetrazolium reduction was determined as an index of superoxide generation.

Results: Superoxide dismutase-inhibitable nitroblue tetrazolium was increased markedly after FPI and these increases were blunted by SODCAT (1,000 U/kg and 10,000 U/kg, respectively) treatment 30 min before FPI (1 +/-1 vs. 14+/-2 vs. 1+/-1 pmol/mm2 for control, FPI, and FPI pretreated with SODCAT, respectively). Methionine enkephalin, an endogenous micro opioid agonist, produced vasodilation that was attenuated by FPI and partially restored by SODCAT pretreatment (17 +/-1, 8+/-1, and 14+/-1% for methionine enkephalin 10 sup -6 M during control conditions, after FPI and after FPI pretreated with SODCAT, respectively). Methionine enkephalin-induced dilation was associated with increased cerebrospinal fluid cyclic guanosine monophosphate and these biochemical changes were likewise blunted by FPI and partially restored by SODCAT (342+/-12 and 640 +/-13 vs. 267+/-6 and 321+/-17 vs. 301 +/-9 and 504+/-43 fmol/ml for resting conditions and 10 sup -6 M methionine enkephalin during control, after FPI, and after FPI pretreated with SODCAT, respectively). Leucine enkephalin, an endogenous delta agonist, induced pial dilation and associated changes in cerebrospinal fluid cyclic guanosine monophosphate, which were similarly altered by FPI and partially restored by SODCAT. Dynorphin, an endogenous kappa agonist, which has been shown to revert from a dilator to a constrictor after FPI, was restored to a vasodilator by SODCAT (18 +/-1, -11+/-4, and 17+/-5% for dynorphin 10 sup -6 M during control conditions, after FPI, and after FPI pretreated with SODCAT, respectively). Dynorphin-induced vasodilation was associated with a large increase in cerebrospinal fluid cyclic guanosine monophosphate, which was blunted by FPI and partially restored by SODCAT.     

Neutralization Susceptibility of B Subtype Variant B' Primary HIV-1 Isolates

Susceptibility to autologous and heterologous neutralization of primary human immunodeficiency virus (HIV)-1 isolates belonging to subtype B, to the B'-variant of subtype B or to subtype F from infected individuals residing in Rio de Janeiro was assayed. A lower infectivity of the B'- and F isolates when compared to the classical B-subtype HIV-1 isolates was observed. Comparisons of neutralization susceptibilities were carried out for 19 B-subtype, 11 B'-variant and two F-subtype HIV-1 isolates with plasma from autologous and heterologous samples. Frequency of autologous neutralization was slightly lower for B-subtype isolates in comparison to B'-variant isolates. Heterologous intra-subtype neutralization was significantly lower for B-subtype than for the B'-variant or the F-subtype isolates. While B-subtype isolates were neutralized by most anti-F-subtype plasma, F-subtype isolates, although most susceptible to F-subtype antibodies, were highly susceptible to neutralization by anti-B-subtype antibodies. Cross-neutralization for B'-variant and B-subtype isolates was not as extensive as observed for B- and F-subtype isolates. However, the results presented indicate a quite extensive cross-neutralization between Brazilian HIV-1 isolates.