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.     

~(125)Ⅰ眼镜蛇毒及抗眼镜蛇毒血清在小白鼠体内分布的比较观察

用氯胺-T法125I标记眼镜蛇毒示踪液及抗眼镜蛇毒血清。小白鼠分二组，用125I-眼镜蛇毒、125I-抗眼镜蛇毒血清分别给小白鼠尾静脉注射，于注射后的不同时间测定血、颈部肌肉、肝、肺、肾、心等脏器放射性分布。结果发现：125I-眼镜蛇毒在肌肉及肝、肺等器官中于注射后2小时过高峰，在肾脏中浓度高，在脑未见放射性分布，抗眼镜蛇毒血清与眼镜蛇毒分布相似但在肌肉及肺脏有更高的分布。证明抗眼镜蛇毒血清能跟踪分布眼镜蛇毒。     

Central circulation in rats with different tolerance to acute blood loss

Study of the dynamics of cardiac output in rats with different tolerance to acute massive blood loss showed that the pumping ability of the heart remains intact during the entire posthemorrhagic period in all high-resistant and in 65% low-resistant rats. In 35% rats that were low-resistant to blood loss, the cardiac output deficiency syndrome developed after cessation of bleeding against the background fall in arterial pressure and a decrease in the hepatic blood flow, which are the signs of rapid variant of the dysfunction produced by acute blood loss. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 10, pp. 384–388, October, 1998