Mesolimbic deficits exacerbate amphetamine treatment: clinical implications for drug abusers

Amphetamine, a common drug used by abusers, is able to produce a schizophreniform psychosis in man. The experiment reported here examined amphetamine in relation to its role in the nucleus accumbens septi (NAS) and the globus pallidus. The effects produced by apomorphine, a direct dopamine (DA) agonist, were compared with those of amphetamine, a known indirect DA agonist. The data revealed that amphetamine in NAS-lesioned animals produced very active stereotypy which intensified with time. This effect was blocked by pallidal lesioning. Apomorphine in pallidectomised rats produced persistent stereotypy, but of diminished intensity. The results are discussed in terms of the mediating roles of the NAS and globus pallidus on behavioural sequelae. (AU)

Abdominal hysterectomies at area hospital, Point Fortin, Trinidad, West Indies

A retrospective analysis of abdominal hysterectomies (3.08 percent of major operations) at the Area Hospital (52 beds), over a 5-year period revealed that the majority of the patients were multiparous in the reproductive age group. Menstrual irregularity is the most frequent indication, however, hysterectomy in these cases is not justified. High febrile morbidity (38 percent), blood transfusions and prolonged hospitalization were observed. Peer review, prophlactic antibodies and survey of the Island hospitals are recomended to make hysterectomy approprite, safe and to explain any racial variation.(AU)

Review of the effects of Cannabis on mental and physiological functions: justification for an Intensive and Comprehensive Programme for the health of the Caribbean people

This paper draws on scientific work done in the English-speaking Caribbean in an attempt to assess the specific effects of the chronic use of Cannabis on psychological and physiological processes. Evidence is reviewed concerning the interaction of this psychotomimetic compound on cognitive functioning and the possible sequelae of altered mental states giving rise to psychopathology. The physiological work evaluates studies relating to Cannabis smoke and lung function. In addition, the work reveals some exciting findings of the impact of Cannabis on the reproductive process. The implications of these findings are discussed in view of our knowledge of the chronic use of Cannabis in Jamaica, and focuses attention on the long-term effects of this substance in the context of the abusing population (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 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)

Evidence to support the influence of the nucleus accumbens on drug-induced psychopathology

This study was designed to evaluate the hypothesis that the mesolimbic dopamine pathways are involved in the manifestations of psychotic symptoms. Rats were injected with amphetamine (5.0 mg/kg) and apomorphine (1.0 mg/kg) following bilateral lesions of the nucleus accumbens. The results showed high levels of stereotypy following amphetamine administrations in contrast to the low levels seen after the administration of apomorphine. These results, in conjunction with previous experiments involving the globus pallidus, were evaluated in terms of the accumbens' influence on drug-induced psychosis (AU)

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)

Long-term effects of marihuana smoke on uterine contractility and tumour development in rats

The present investigation considered the role of acute and chronic marihuana smoking, as well as crude extracts of marihuana (ME), on uterine contractions and tumour development. The contractions and the electrical activity were recorded on isolated superfused rats' uteri. Enhanced spontaneous activity and contractile responses were observed following exposure to marihuana smoke. Atropine failed to block contractile responses with ME following chronic smoke exposure. It is suggested that ME contains both contractile and relaxing properties. Chronic exposure to marihuana smoke resulted in appearance of various tumours in 50 percent of experimental animals. This study suggested far-reaching consequences on reproductive activity following chronic use of marihuana (AU)

Socio-economic status and lung function in Jamaican children

A study was carried out in Afro-Jamaican children of both sexes, 6 to 15 years of age, to examine the role of socio-economic status on various pneometric tests such as forced vital capacity (FVC), mid-expiratory flow rate (MEFR 0.2-1.2), mean transit time (MTT), peak expiratory flow rate (PEFR), forced expiratory volume (FEV 1.0) and FEV 1.0 percent. Based on the annual income of the parents, the children were subdivided into 3 groups (I,II,III). Statistical analysis of the data revealed significant differences in all pulmonary function tests in children >10 years of age in both sexes and in all the groups, except PEFR in girls and MEFR 0.2-1.2 in boys <10 years of age in group II. The girls belonging to the same groups had higher values for all lung functions except significantly lower values of MTT. The study suggests differences in both central and peripheral airway function, with poorer function in the lower income group children who may be more susceptible to subclinical infections, probably due to malnutrition. The lower lung function in boys was attributed inter alia to lower mean values of height and weight than in girls (AU)

Contractile response of uterine smooth muscle to acetylcholine and marijuana extract

Marijuana extract (ME) is known to influence smooth muscle activity. This study was designed to investigate the effect of crude ME on rat uterine muscle and to explain the mechanism of action using antagonists such as atropine, ergometrine and propranolol. The contractions and the electrical activity were recorded on isolated superfused rat uteri. It is speculated that ME by its uterine stimulation action compromise uterine blood and may affect oxygen/nutrient transfer. The implication of this to the fetus is discussed. (AU)

Uterine stimulatory action of marihuana extract - abstract

Marihuana extract (ME) is known to influence the smooth muscle activity. This study was desinged to investigate the effect of crude ME on rat uterine muscle and to explain the mechanism of action using antagonists such as atropine, ergometrine and propranolol. The contractions and the electrical activity were recorded on isolated superfused rat uterus. Spontaneous contractions were observed during superfusion with Nañ-Kerb's solution (KrM) which were abolished in Nañ-free Li medium (LiM) but with persistent electrical activity. Acetylcholine (ACH0 and ME produced contractions inKrM and LiM. The magnitude of these responses were reduced by 24 percent to 55 percent in Lim. Atropine blocked the effect of Ach and ME in Lim and KrM, whereas ergometrine and propranolol abolished the responses in the former and in the latter the response was attenuated by 65 percent. The results suggested that the action of ME is similar to that of Ach. Absence of spontaneous activity in LiM could be due to reversal of Nañgradient. Inability to refill Ca++ store could partially explain the total absence of responses with alpha and bet receptor antagonists in LiM. It is speculated that ME by its uterine stimulatory action compromises uterine blood and may affect oxygen/nutrient transfer, thereby affecting the foetal development(AU)