The quantity of rhodopsin in human eyes

The content of rhodopsin in the eyes of 15 donors (30 eyes) was determined. Both retinal and pigment epithelial fractions were collected from each globe, extracted using 1% CTAB, and the rhodopsin difference spectrum of each fraction was obtained separately. The total amount of rhodopsin, obtained by summing the amounts recovered from the retinal and PE fractions, ranged from 2.00 to 11.94 (median: 6.40) nmoles/eye. Previously reported mean values of about 3.5 to 4.0 nmoles per retina have been obtained using a variety of methods. The present higher values, perhaps largely dependent on procedural details described herein, appear plausible given the known concentrations of rhodopsin in rod outer segments, rod outer segment volumes, and number of rods in the human retina.     

Carney's triad

A 26 year old female presented with partial expression of Carney's triad. This is the first Australian report of the condition. The role of surgery and the need for vigilance to detect the occurrence of the complete triad are stressed.     

CARNEY'S TRIAD

A 26 year old female presented with partial expression of Carney's triad. This is the first Australian report of the condition. The role of surgery and the need for vigilance to detect the occurrence of the complete triad are stressed.     

血脂监测在防治Ⅱ型糖尿病患者继发动脉粥样硬化中的意义

目的探讨血脂代谢紊乱跟Ⅱ型糖尿病(ⅡDM)患者继发动脉粥样硬化并症的关系。方法采用奥林巴斯Au-640全自动生化分析仪,测定Ⅱ型糖尿病患者和健康对照组的空腹血糖(GLU)、胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白(HDL-C)、载脂蛋白Al(ApoAl)和载脂蛋白B100(ApoBloo),并进行统计、比较并与患者的病情进行对比分祈,并对高血糖、血脂组患者跟踪观察、治疗。结果Ⅱ型糖尿病组同健康对照组比较、Ⅱ型糖尿病患者中有合并症组跟无合并症组、高血糖组跟血糖正常组比较,CHO、TG和ApoBloo的含量均升高(P<0.05),而HDL-C和ApoAI含量降低(P<0.05)。而高血糖、血脂组患者,已经初步出现或在随后的观察中出现了动脉粥样硬化等相关的临床表征,且治疗效果不佳。结论Ⅱ型糖尿病患者血脂的异常,特别是CHO、TG的大幅升高,提示患者在出现动脉硬化性心血管合并症之前,体内已经具备了诱发合并症的生化基础,应早期采取针性治疗和预防措施。     

Strontium and quantal release of transmitter at the neuromuscular junction

1. Previous work has shown that in calcium-free solutions nerve impulses invade the motor nerve terminals at the neuromuscular junction, but fail to release transmitter. In these conditions, strontium ions applied iontophoretically to a minute part of a junction, or to the whole muscle by bath application, restore to the nerve impulse its ability to release transmitter.2. As with calcium, the transmitter released in the presence of strontium is in the form of packages (quanta) whose release can be predicted from Poisson's Theorem.3. The mean number of quanta released by a nerve impulse increases with the concentration of strontium. Strontium is much less effective than calcium in equimolar concentrations.4. Transmitter quanta released in the presence of strontium evoke larger unit potentials than quanta released in the presence of calcium. The larger size of the Sr-unit potentials is caused by a prolongation of transmitter action, presumably due to a post-synaptic effect of strontium.5. Neuromuscular transmission was blocked in some fibres when the concentration of strontium was raised beyond 10 mM. This junctional block was presumably due to a failure in the propagation of nerve impulses.6. The post-stimulation increase in the frequency of miniature end-plate potentials, which is normally seen in calcium solutions, is also observed when calcium is substituted by strontium. The post-stimulation effect increases with the concentration of strontium.7. It is concluded that strontium can substitute for calcium in the process of quantal release of transmitter. The physico-chemical mechanism of this substitution remains unknown.