Effect of gradual rise in plasma calcium concentration on the impairment of atrioventricular nodal conduction due to verapamil

The possible reversal by calcium of the inhibitory action of verapamil on the atrioventricular (AV) node was investigated in anesthetized, atropinized dogs, with cardiac pacing. The His bundle potentials were recorded by endocavitory electrode and the AV node effective refractory period measured by the extrastimulus method. Calcium infusion was effective against the impairment of AV nodal conduction induced by verapamil, provided it remained moderate: the gradual rise in the plasma calcium concentration counteracted the effects of an infusion of verapamil on conduction time and effective refractory period in the AV node, as long as it did not exceed 5 mmol/L. However, beyond this level, calcium appeared less and less capable of reversing the effects of verapamil. Thus, the protective action of calcium had a bell-shaped dose-response curve, with the optimum at 5 mmol/L. This biphasic influence is consistent with the opposite opinions previously given concerning the antagonism between calcium and calcium blockers, depending on whether hypercalcemia brought into play was mild or major. In any case, the prominent role played by calcium in the slow inward current in the AV node accounts for the antagonism, observed in vivo, between calcium and verapamil. The pacemaker activity of the sinoatrial (SA) node was less influenced by both calcium blocker and calcium.     

The cytochromes P-450 concentrations in microsomes of liver, kidney and duodenal mucosa of the camel, sheep and goat

The concentration of microsomal cytochromes P-450, and of protein in the homogenate, cytosol and microsomes were measured in the liver, kidney and duodenal mucosa of healthy well-fed male and female camels, sheep and goats. For comparison, data from the liver of male and female rats were also obtained. The protein concentrations in the tissues of adult animals were broadly similar in the four species. The concentration of cytochromes P-450 was highest in the liver, followed by the kidney, then the duodenal mucosa in all the species. No cytochromes P-450 were detected in the tissues of immature (less than 1 mo) male goats, whereas the female goat had the highest concentrations of these enzymes in the liver and kidney when compared with the respective tissues in the other species studied. Males had higher activity of cytochromes P-450 than females in the three tissues, except in the duodenal mucosa of sheep, where males had lower activity than females. In camel liver and sheep kidney, the amount of cytochromes P-450 were similar in the two sexes. The present results suggest that the mature female goat is the species best equipped to handle xenobiotics which are detoxified by the cytochromes P-450 and other drug metabolizing enzymes in diseased or malnourished animals is suggested as these two conditions are known to modify drug metabolizing enzymes.     

Specific rubella virus IgG and IgM in umbilical cord sera in Saudi Arabia.

The sensitive ELISA assay was used to measure the specific rubella virus IgG & IgM, and also the total IgM in the umbilical cord sera taken from 182 Saudi mothers during delivery in the Maternity Department at Al Ali General Hospital, Riyadh, Saudi Arabia. Nearly 84.6% (154 out of 182) Saudi women tested were found to be immune to rubella virus.     

Sudden coronary death in Glasgow: the severity and distribution of chronic coronary atherosclerotic stenoses.

A detailed analysis of the extent of coronary artery atherosclerosis was made in 92 white subjects (66 men and 26 women) who died suddenly from ischaemic heart disease. Stenoses resulting in loss of greater than or equal to 75% of luminal cross sectional area (significant stenosis) were found in 90 subjects and these were more extensive in the proximal coronary tree than in the distal. Thirty nine per cent had triple vessel disease, 37% had double vessel disease, and 23% had single vessel disease. In addition one man had an isolated significant stenosis affecting the left main coronary artery. The frequency of significant stenoses in the left main coronary artery was greater in men than in women. The arteries that were least affected were the distal branches of the right coronary artery. A notable feature was the widespread nature of the coronary atherosclerosis: only 26 of the total of 1840 segments of coronary artery examined in the 92 victims could be described as having a normal intima (less than or equal to 10% loss of the area within the internal elastic lamina).     

Enhanced progesterone and testosterone secretion and depressed estradiol secretion in vitro from small white follicle cells of incubating turkey hens

This study was conducted to determine if lower steroid secretion by the small white follicles in incubating turkey hens contributes to lower circulating steroid concentrations during this time. Turkey hens were grouped as either laying or incubating. Serum samples and the ovarian small white follicles (SWF; 2-7 mm diameter) were collected from each hen. The SWF were pooled for each group and their cells were dispersed by trypsin digestion. Serum-luteinizing hormone (LH), progesterone (P), testosterone (T), and estradiol (E) concentrations were lower and serum prolactin concentration was higher during incubation than during egg laying. SWF cells from incubating hens secreted more P and T and less E in response to ovine luteinizing hormone (oLH) than did similar cell suspensions from laying hens. The incubating hens' SWF cells' capacity to secrete E but not their capacity to secrete P or T in vitro is consistent with the observed circulating levels. It is hypothesized that lower levels of circulating LH and/or higher levels of prolactin found in incubating hens may have a depressing effect on aromatase activity and/or an up-regulating effect on LH-induced P and T secretion by the SWF cells.     

The course of pregnancy among mothers above 35 years and its outcome in Kafr-El-Zayat.

A group of pregnant mothers above 35 years old were collected from the MCH centre in Kafr-El Zayat during a period of 10 months (82). A control group of mothers aged 20-30 years old were also selected during the same period (62). Those with specific diseases from both groups were excluded. During the repeated visits of those mothers to the MCH centre they were subjected to complete history taking, physical examination plus urine analysis & haemoglobin levelling. A special visit was performed by the researcher to the mothers on 7th day after labour to report on the outcome of labour. The present study revealed significant differences between mothers over 35 years and those of 20-30 years in the course of pregnancy, labour and their outcomes where the former group showed greater tendency to be at a higher risk.     

Oral and subcutaneous sumatriptan in the acute treatment of migraine: an open randomized cress-over study

In an open, randomized cross-over study in 124 patients, we compared the efficacy, safety and patient preference of oral and subcutaneous sum triptan in the acute treatment of migraine. Patients were treated for 3 attacks or 3 months and then crossed over. Primary clinical efficacy was defined as a reduction in headache severity on a four-point self-rating scale from severe (3) or moderate (2) to mild (1) or none (0), or mild (1) to none (0). Efficacy was evaluated 2 h after the administration of subcutaneous and 4h after the administration of oral sumatriptan. Subcutaneous sumatriptan was significantly more effective than oral sumatriptan in relieving headache (over all three attacks 78% vs 61% improvement), improving clinical disability (55% vs 41 % improvement) and relieving nausea (69% vs 53%), vomiting (72% vs 32%) and phono- or photophobia (67% vs 49%). Median time to recurrence was shorter after subcutaneous (12.5 h) than after oral sumatriptan (18 h); the number of patients experiencing a recurrence was similar Patients reported more adverse events after subcutaneous sumatriptan (1.32 per attack) than after the oral form (0.85 per attack), but all adverse events were mild to moderate in intensity and of short duration. Patient opinion was more often positive after subcutaneous sumatriptan. These results may be useful in counselling patients to choose between the available marketed formulations of sumatriptan.     

蝮蛇抗栓酶与肝素抗凝治疗小儿肾病的疗效比较

本文对60例小儿肾病患儿随机分为3组,蝮蛇抗栓酶治疗组,肝素治疗组,常规治疗组(对照组),结果总有效率分别为95％,90％,60％。蝮蛇抗栓酶组与对照组比较,差异有极显著性(P<0.01),肝素组与对照组比较,差异有显著性(P<0.05)。结果提示抗凝治疗对小儿肾病高凝状态有明显改善作用,能增加临床疗效。蝮蛇抗栓酶抗凝效果优于肝素。