Characterization of unique ADTN-catecholamine binding sites in the iris root-ciliary body of rabbits

A binding site for tritiated 2-amino-6, 7-dihydroxy-1, 2,3,4-tetrahydronaphthalene (ADTN) has been partially characterized in the rabbit iris root-ciliary body. Binding of ADTN is proportional to protein content and requires at least 60 minutes to reach equilibrium. Binding is saturable, with a Kd of 27 +/- 1 nM and a Bmax of 2.1 +/- .3 pmol/mg protein (mean +/- SEM). Dopamine competes for this site with a Ki of 100 nM and apomorphine with a Ki of 180 nM. This site is not blocked by L-timolol, phenoxybenzamine, or by several DA1 and DA2 antagonists. It appears to be a new type of catecholamine binding site, of a type not observed outside the anterior eye. It is possible that some of the effects of dopamine on intraocular pressure are mediated through this binding site.     

Structure-activity relationship (SAR) between some natural flavonoids and ocular blood flow in the rabbit.

PURPOSE: Flavonoids with two to five hydroxy groups, with or without sugar, and/or methoxy groups were studied on their effects to affect ocular blood flow. METHODS: Colored microsphere technique was used to determine the ocular blood flow in rabbit eyes. RESULTS: Flavonoids with three free hydroxy (OH) groups seemed to produce the optimal effects in increasing ocular blood flow (naringenin and hesperitin, Pfalts and Bauer, Waterbury, CT). Whether the OH groups are below three (naringenin, hesperitin, Pfalts and Bauer, Waterbury, CT) or above four (Quercetin, Pfalts and Bauer, Waterbury, CT), they produced no effects on the ocular blood flow. When OH groups are four (rutin, Aldrich, Milwaukee, WI), it produced mixed effects on ocular blood flow. The attachment of rutinose and/or methoxy group in the structure did not affect the ocular blood flow one way or the other. CONCLUSION: The ocular blood flow is increased significantly by the number of OH group in the molecule, with three the best to increase the ocular blood flow.     

Astragalus membranaceus flavonoids (AMF) ameliorate chronic fatigue syndrome induced by food intake restriction plus forced swimming

Aim of the study

Alteration of immune function may be associated with chronic fatigue syndrome (CFS) and this study reveals the immunoregulatory effect of Astragalus membranaceus flavonoids (AMF).

Materials and methods

CF rats were induced by food intake restriction plus forced swimming for 6 weeks.

Results

An atrophied spleen associated with a significantly decreased spleen/body weight ratio and a reduced spleen cells proliferation was found in CF rats when compared with home cage controls. AMF given orally at 20, 50 and 100 mg/kg body weight once a day consecutively for 6 weeks could recover the reduced cell proliferation. A switch to Th1-dominated immune regulation was observed in CF rats as the cultured splenocytes produced more interleukin-2 (IL-2) but less IL-4 when compared with controls. Supplementation with AMF could significantly counteract the aberrant cytokine production and rats received AMF exhibited higher endurance capacity to swim when compared with those without AMF administration. Checking the spectrum signals confirmed that the three major isoflavones contained in AMF were ononin, formononetin, and demethylhomopterocarpin.

Conclusion

Alterations of immune function may be associated with CFS and the tonic effects of AMF against CF may be attributable to balance the abnormal cytokine level by isoflavones.     

Pediatric traumatic brain injuries in Taiwan: an 8-year study.

Background. This study is intended to determine the causes of pediatric traumatic brain injuries (PTBI) in children aged 14 years or less, and to identify various types of craniocerebral damage resulting from different mechanisms of injury.Methods. From July 1, 1993 to June 30, 2001, a survey on PTBI was conducted in Taiwan. The data of patients used in this study were collected from 56 major hospitals among the age group of 0-14 years. The items in the traumatic brain injury survey included sex, age, causes of injuries, severity, and the eventual outcome.Results. A total of 5349 cases were identified. The male-to-female ratio was 1.69: 1. The incidence rate was higher in the age groups of 4-9 years and 10-14 years. The main cause of PTBI was traffic injury, which accounted for 2537 of the cases (47.3%), followed by falls, 2160 (40.3%). Of all traffic injuries, motorcycle-related injury had the highest incidence, followed by the pedestrian and bicycle-related injury. This study also showed that 83.2% of the patients had mild injury, 9.8% had moderate injury, and 7.0%, severe injury.Conclusions. The results of this study suggest that it is important to decrease all the risk factors in the environment of homes and public areas as much as possible. Helmet wearing and the development of public transportation are essential for the prevention of head injury.     

异落新妇甙的结构研究

从百合科菝葵属植物土茯苓(Smilaxg labra Roxb.)根茎的乙醇提取物中分得一个新的天然化合物(I),命名为异落新妇甙(isoastilbin)。根据元素分析,UV,IR,¹H-NMR,¹³C-NMR,2DNMR及FAB-MS,确定化合物I的结构为5,7,3',5'-四羟基二氢黄酮醇-3-O-α-L-鼠李糖甙。     

Effects of epinephrine on retinal and choroidal blood flow through different routes of drug administration

Epinephrine (1, 3 and 10 micrograms/kg) was found to increase retinal and choroidal blood flow (22, 49 and 67%) when it was administered intravenously. The increase in retinal and choroidal blood flow coincided well with the increase in systemic blood pressure (44, 65 and 96%, respectively). When epinephrine (2%) was instilled to the eyes topically the retinal and choroidal blood flow decreased (15%) while systemic blood pressure remained unchanged. It is suggested that the decrease in retinal and choroidal blood flow by topical epinephrine could be the cause of epinephrine maculopathy reported previously. L-Timolol (0.25%, topically) did not affect retinal and choroidal blood flow significantly.     

LHRH-A对孕中期大鼠抗妊娠作用的研究

本文观察了[D-Ala⁶,Pro⁹-Ethylamide¹⁰]-LHRH(LHRH-A)对孕中期大鼠的抗妊娠作用。结果显示:在孕9～11d sc 200μg/d LHRH-A,血浆孕酮水平自第二次给药后明显下降(P<0.05),给药大鼠均流产终止妊娠;LHRH-A的抗妊娠作用可被醋酸甲地孕酮所拮抗;LHRH-A对体外培养的假孕大鼠和孕d 9大鼠黄体细胞分泌孕酮有明显的直接抑制作用。