弥漫性轴索损伤病人的护理

弥漫性轴索损伤 (DAI) ,在脑损伤中发生率高 ,病死率高 ,占脑外伤死亡病人总数的 3 5 %。全部DAI病人中植物生存率为 15 % ,重残 14 % [1] 。为了降低病死率 ,提高病人的生存质量 ,现将 1999年 1月— 2 0 0 2年 1月我院收治的 5 5例DAI昏迷病人的护理体会总结如下。1　临床资料　　本组 5 5例 ,男 3 8例 ,女 17例 ,年龄 6岁～ 68岁 ,平均 40 .9岁。格拉斯哥 (GLS)计分均 <8分 ,其中评分为 3分～ 5分的特重型病人 3 2例。致伤原因 :车祸 44例 ,高处坠落 8例 ,打击伤 3例。 5 5例病人中有 17例因合并颅内血肿而行开颅手术 ,其他病人为保…     

Synthesis and Purine P2X Receptor Antagonist Activity of Thiazole Derivatives

The ability of 12 new thiazole derivatives to influence the muscle contractility mediated by purine P2X receptors has been studied in vitro using isolated tissues of rats and guinea pigs. Most of the synthesized compounds did not cause significant effects, but two compounds exhibited pronounced antagonism with respect to P2X-mediated contractility response. These compounds offer a good starting point for the synthesis of new effective antagonists of P2 receptors. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 39, No. 6, pp. 22 – 25, June, 2005.     

Effect of kanamycin on the cochleas in guinea pigs

Kanamycin (400 mg/kg) was injected daily for 5 days in guinea pigs, the changes in CM and AP responses were recorded. The CM threshold was elevated in 34.5% of the animals and the CM amplitude was reduced when compared with normal animals (P less than 0.005). The AP threshold was elevated in 13.8%. The latency of N1 was increased (P less than 0.001) and the amplitude of N1 reduced at 80 dB (S-L) (P less than 0.001).cAMP and cGMP levels in the organ of Corti and stria vascularis spiral ligament decreased, and the decrease correlated with the changes in auditory function. We consider the reduction of cyclic nucleotides in the cochlea may be important in kanamycin ototoxicity.     

Intraocular pressure and axial length in children

The intraocular pressure and the anteroposterior length of the eye are of great clinical importance for the diagnosis and management, before and after surgery, of congenital glaucoma. It is well-known that normal intraocular pressure in children is different from the normal levels in adults. We performed measurements of intraocular pressure and axial length in 141 children who had been admitted for eye problems other than glaucoma. The intraocular pressures were measured with the Perkins hand-held applanation tonometer at the beginning of general anesthesia. Simultaneously, A-scan ultra-sound measurements of the axial lengths of the eyes were made. In 10 children under the age of two years, the intraocular pressure was 11.85 +/- 1.35 mmHg. In 79 children from two to seven years, the intraocular pressure was 12.80 +/- 1.73 mmHg. In 52 children from seven to 15 years, the intraocular pressure was 13.31 +/- 1.79 mmHg. The axial lengths of the eyes in children under the age of two years, from two to seven years, and from seven to 15 years, were 21.31 +/- 0.97 mm, 22.04 +/- 0.92 mm, and 23.22 +/- 1.00 mm, respectively. These results were considered to be guidelines for measuring intraocular pressure and axial length in children suspected of having congenital glaucoma. The differences of intraocular pressures stated by other authors are due to early measurement of the intraocular pressure at the beginning of general anesthesia.     

Activity-dependent Decay of Early LTP Revealed by Dual EPSP Recording in Hippocampal Slices from Young Rats

The early maintenance of long-term potentiation (LTP) was studied in the CA1 region of hippocampal slices from 12- to 18-day-old rats in a low-magnesium solution (0.1 mM). The α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptor-mediated components of the field excitatory postsynaptic potential were estimated in parallel using early and late measurements of the composite potential. At the normal test stimulus frequency of 0.1 Hz, LTP was seen initially as a predominant increase in the AMPA component, but converted, via a substantial decay of this component and a gradual growth of the NMDA component, into nearly equal changes of the two components. Interrupting the test stimulation for 10 min, changing the test stimulus frequency to 1/60 Hz after LTP induction, or using a test stimulus frequency of 1/60 Hz during the entire experiment significantly reduced the decay of the potentiation of the AMPA component while enhancing the potentiation of the NMDA one. The ratio between the magnitudes of the two excitatory postsynaptic potential (EPSP) components showed a decaying time course that was independent of the manipulations used. Application of the NMDA antagonist D(-)-2-amino-5-phosphonopentanoic acid (50μM) after LTP induction stabilized the LTP of the AMPA component until washout was started. On the other hand, the phosphatase inhibitor okadaic acid (1 μM) resulted in decay of the potentiation of both EPSP components back to around baseline and altered the time course of the ratio between the components. Our results show that the early maintenance of LTP is controlled in an activity-dependent and NMDA-dependent manner. This process accelerates the decay of LTP of both AMPA and NMDA components in parallel, suggesting that it is similar to homosynaptic long-term depression, although it operates at the normal test stimulus frequency. The data support a scenario in which LTP ensues as a selective AMPA receptor modification and subsequently converts to another modification, possibly a presynaptic one.