Test for autonomic function to establish the norm: a useful tool for evaluation in various clinical disorders

Little information is available regarding the responses of the Jamaican population to the Valsalva manoevre (VM), a test to investigate the integrity of the autonomic nervous system (ANS). This study is aimed at investigating the cardiac autonomic control in the Jamaican population, to explore the range of responses and to establish the norm. Such an explorative investigation provides an important tool to uncover autonomic dysfunction in psychosomatic, cardiopulmonary, metabolic and neural disorders. Fifty male and fifty female Jamaicans, who were apparently healthy and did not indulge in any drug use and smoking, are asked to perform the VM in a semirecumbent position. A tachograph (Grass model) and standard electrocardiographic leads are used for the graphic presentation of the subjects' beat-to-beat heart rate changes. The Valsalva ratio (VR) is calculated by dividing maximum tachycardia and maximum bradycardia during the VM. The mean VR for the female (2.41ñ0.18) is greater than that for the male (1.63ñ0.27) (p<0.001). Female subjects exhibit a higher basal heart rate (88+6 as against 77ñ7 in the male) and a greater magnitude of bradycardia (33 as against 4 in the male). The values for VR are above the minimum of 1.5 proposed in the literature. Relative roles of the sympathetic and parasympathetic nervous systems may differ in the male and female subjects, thus accounting for a higher VR in the female. This test is simple, safe, noninvasive and reproducible and is useful to detect the abnormal autonomic function in various conditions, including states of pregnancy and stress (AU)

Test for autonomic function to establish the norm: a useful tool for evaluation in various clinical disorders

Little information is available regarding the responses of the Jamaica population to the Valsalva manoeuvre (VM), a test to investigate the integrity of the autonomic nervous system (ANS). This study is aimed at investigating the cardiac automonic control in the Jamaican population, to explore the range of responses and to establish the norm. Such an explorative investigation provides an important tool to uncover autonomic dysfunction in psychosomatic, cardiopulmonary, metabolic and neural disorders. Fifity male and fifty female Jamaicans, who were apparently healthy and did not indulge in any drug use and smoking, are asked to perform the VM in a semirecumbent position. A tachograph (Grass model) and standard electrocardiographic leads are used for the graphic presentation of the subjects' beat-to-beat heart changes. The Valsava ratio (VR) is calculated by dividing maximum tachicardia and maximum bradicardia during the VM. The mean VR for the female (2.41 ñ 0.18) is greater than for the male (1.63 ñ 0.27) p < 0.001). Female subjects exhibit a higher basal hearth rate (88 ñ 6 as aginst 77 ñ 7 in the male) and a greater magnitude of bradycardia (33 as against 4 in the male). The values for VR are above the minimum of 1.5 proposed in the literature. Relatice roles of the sympathetic and parasympathetic nervous systems may differ in the male and the female subjects, thus accounting for a higher VR in the female. This test is simple, safe, noninvasive and reproducible and is useful to detect the abnormal autonomic function in various conditions, including states of pregnancy and stress

Reproductive toxicity of marihuana smoke a three-generation study in female wistar rats

A three-generation study on the effects of marihuana smoke on female wistar rats was carried out. The mother/parent generation (Gm) and Gf(first generation) were each bred once to give rise to Gf and Gs(second generation) respectively. Reproductive indices studied included oestrous activity, fertility index,gestation of dams, gestation index, gestation survival index, number of pups born alive and pup birth weight. Reproductive toxicity was observed in this study as evidenced from the delayed onset of oestrous activity, frequently occurring oestrous cycles with shortened period of oestrous, reduced fertility index, premature parturition, diminished pup birth weight, reduced litter size as well as gestation survival index. This work shows that when marihuana is inhaled, neither oestrous activity nor ovarian activity is totally suppressed, but it is affected to a significant degree. Influence of marihuana smoke on excitability of uterine smooth muscle, transfer/utilization of nutrients and on hypothalamo-hypophyseal-ovarian axis was proposed to explain its reproductive toxicity. This study bears clinical implications and is useful in the counselling of female marihuana smokers (AU)

In vitro human placental perfusion studies cholinergic activity in normal subjects and in toxaemia of pregnancy

The present study was designed to investigate acetylcholine (ACh) concentration in normal and toxaemic placentae. The perfusate from placental lobules was collected at different time intervals and analysed, by bioassay, for ACh. The results showed that ACh concentration was time-dependent, attaining its highest value by 90 minutes (74.465 ñ 0.76 10-9 g/ min/g), which was maintained for up to 180 minutes placentae. Similar observations were made in the toxaemic samples, but the values were significantly lower, when compared to the control group (44.36 ñ 1.54 10-9g/min/gt at 90 minutes). This study demonstrated active secretion of Ach by the placentae and the occurrence of low ACh concentration in toxeamia. It is postulated that low ACh could probably interfere with local transport mechanism and account for low birth weights in toxaemia.(AU)