Quality variations in black musli (curculigo orchioides gaertn.).

Black musli (Curculigo orchioides Gaertn.) one of the ayurvedic dasapushpa and a rejuvenating and aphrodisiac drug. Is on the verge of extinction and needs to be conserved and cultivated. Large variations are also observed in the quality of the crude drug available in the market. Study on the quality of C. orchioides in natural habitat, under cultivation and in trade in south India showed that there was considerable variation with biotypes and habitats. Drugs collected form the natural habitat was superior in quality to that produced by cultivation. Among the market samples collected from the various Zones of kerala, those from the High Ranges were superior in most of the quality parameters, which indicated its superiority for high quality drug formulation. Among the southern states, Tamil Nadu samples ranked next to High Range samples in this respect. There exists large variability in the market samples and there is felt-need for proper standardization of the crude drug for ensuring quality in the drug formulations.

The role of pacemaker therapy in the prevention of atrial fibrillation.

Atrial fibrillation (AF) has been recognized, with increasing concern, as a potentially disabling illness, occurring either as a symptom of many cardiac diseases or as an isolated disorder. It can independently contribute to mortality and morbidity and may have serious prognostic importance in acute or chronic cardiac disease. In patients with symptomatic drug refractory atrial fibrillation, ventricular rate control by atrioventricular nodal ablation or modification commonly results in pacemaker implantation. The concept of AF prevention by pacemaker therapy has been introduced in patients with bradycardia-tachycardia syndrome or vagally mediated bradycardia-dependent AF. In patients with sick sinus syndrome, atrial pacing has proved to be more effective than VVI pacing in maintaining the electrical stability of the atrium in long-term follow up. Recently, the development of new techniques of atrial pacing employing pacing at two atrial sites may improve the effectiveness of the AF prevention by pacemaker therapy. Dual-site right atrial pacing using overdrive stimulation activates simultaneously the high right atrium and the left atrium via the ostium of the coronary sinus. Two main mechanisms have been proposed to explain the favourable effect of this technique. One is the suppression of atrial premature beats initiating AF by the overdrive pacing. The second is the alteration of atrial activation pattern by preexcitation of the area of the coronary sinus ostium which permits earlier recovery of excitability in sites of atrial conduction delay. The combination of drug therapy and pacing is essential for effective AF control. We have hitherto studied 30 patients with single- and dual-site pacing. Single-site pacing was performed at the high right atrium or coronary sinus ostium. The dual-site pacing mode increased the arrhythmia-free intervals, decreased patients' arrhythmia-related symptoms and anti-arrhythmic drug use as compared to the period preceding institution of pacing and incrementally over conventional high right atrial pacing alone. A multicentre randomized trial, Dual-site Atrial Pacing for Prevention of Atrial Fibrillation (DAPPAF), evaluating three pacing modes (dual-site, single-site and support pacing), is now in progress.

Prevention of recurrent atrial fibrillation with chronic dual-site right atrial pacing.

OBJECTIVES: We investigated 1) the feasibility, safety and efficacy of multisite right atrial pacing for prevention of atrial fibrillation (AF); and 2) the ability of atrial pacing in single- and dual-site modes to increase arrhythmia-free intervals in patients with drug-refractory AF. BACKGROUND: We recently developed and applied a novel technique of dual-site right atrial pacing in an unselected group of consecutive patients with AF requiring demand pacing. A prospective crossover study design was used to evaluate single- and dual-site right atrial pacing modes. METHODS: The frequency of AF during the 3 months before pacemaker implantation was analyzed. Consecutive consenting patients underwent insertion of two atrial leads and one ventricular lead with a DDDR pulse generator. Patients were placed in a dual-site pacing mode for the first 3 months and subsequently mode switched to single site pacing for 3 months. Mode switching was repeated at 6-month intervals thereafter. RESULTS: Atrial pacing resulted in a marked decline in AF recurrences (p < 0.001). During dual-site pacing with an optimal drug regimen, there was no AF recurrence in any patient compared with five recurrences in 12 patients during single-site pacing (p = 0.03). The mean (+/-SD) arrhythmia-free interval before pacing (14 +/- 14 days) was prolonged with dual- (89 +/- 7 days, p < 0.0001) and single-site pacing (76 +/- 27 days, p < 0.0001). Symptomatic AF episodes showed a declining trend during dual- and single-site pacing compared with those during the preimplantation period (p = 0.10). Mean antiarrhythmic drug use for all classes declined from 4 +/- 1.9 drugs before implantation to 1.5 +/- 0.5 (p < 0.01) drugs after implantation. Twelve (80%) of 15 patients remained in atrial paced rhythm at 13 +/- 3 months. CONCLUSIONS: We conclude that multisite right atrial pacing is feasible, effective and safe for long-term application. Atrial pacing significantly prolongs arrhythmia-free intervals in patients with drug-refractory paroxysmal AF. Dual-site right atrial pacing may offer additional benefits and should be considered either as the primary mode or in patients unresponsive to single-site pacing.

Seroepidemiology of rubella in Bahrain.

Although the Ministry of Health of the State of Bahrain has set priorities for vaccination against a number of communicable diseases including the six target diseases of the Expanded Program of Immunization, no such policy for rubella immunization exists. The incidence of rubella in Bahrain is not precisely known nor is the magnitude of the problem of Congenital Rubella Syndrome. A survey of schoolchildren and primigravidae attending antenatal clinics was undertaken in Bahrain to determine the level of natural immunity against rubella in these groups, which we hope would help us in formulating a vaccination policy. We have found that 67.8% of the 6-7 year old children are susceptible to rubella and that by the age of 18 years susceptibility drops to 10.4%. The decrease in susceptibility was significant until the age of 14 years after which the change became minimal. Efforts should ideally be focused on immunizing all susceptible females before they get married. However, at present, it would be more economical to vaccinate all girls premaritally than to screen and vaccinate those susceptible. When a cheaper screening test for assessing immunity against rubella becomes available, a policy of premarital and post-partum screening followed by vaccination of susceptibles should be put into practice.

Cholera in Bahrain: epidemiological characteristics of an outbreak.

In the period 10 August 1978-23 January 1979, 913 culture-confirmed cases of cholera caused by Vibrio cholerae, biotype El Tor, serotype Ogawa, occurred in Bahrain. After discovery of the initial cases, others occurred sporadically, and the incidence reached a peak of 25-35 cases per day during the seventh week of the outbreak (16-22 September). The overall attack rate (27 per 10 000) was low and the outbreak subsided without mass immunization campaigns or rigorous border control of persons and imports. Investigation of 746 culture-confirmed cases that occurred in the period 10 August-13 October 1978, showed that cases occurred throughout most areas of the country and mainly affected infants, young children, and adult working-age males. Symptoms were very mild; fewer than 20% of patients required specific rehydration therapy. The highest attack rate (84 per 10 000) occurred in infants less than 1 year of age. No common vehicle or mode of transmission was identified. A matched-pair study of 35 cases and controls showed that adult cases were more likely than controls to have consumed food or beverage outside of the home before becoming ill. V. cholerae was isolated from stored drinking water in the houses of 8 cases but not from numerous samples of food and tap-water. It was presumed that cholera transmission occurred through a complex interaction of mild and asymptomatically infected persons with food, water, and the environment.

Poliomyelitis survey in Middle-East countries.

The poliomyelitis survey was started in 1976 in Bahrain and Kuwait. For each paralytic case, diagnosis was done by virus isolation, neutralizing antibody titration and specific IgM characterization. More than 90% of the infants who were ill were less than 2 years old. In Bahrain, 17 paralytic cases in 1976 and 12 in 1977 occurred between January and July (annual incidence was respectively 7.7 and 5.4/100,000). The first epidemic was due to poliovirus type 2, the second one to poliovirus type1. From 29 cases, 13 occurred in vaccinated infants of which 9 received 3 or 4 oral vaccine doses. For 3 infants, paralysis occurred less than one month after vaccination. All the isolates were wild polioviruses (rct). In Kuwait, 119 cases were examined, and of them, 57 occurred between August 76 and May 77 (incidence 5.7/100,000). Poliovirus type 1 was responsible for 61% of cases, type 2 for 5% and type 3 for 12%. From October 1976 to December 1977, 350 stools samples were collected from contacts: 19% of them carried poliovirus (12% type 1, 1% type 2 and 6% type 3). All the viruses isolated from both paralytic cases and contacts were wild strains (rct). Of 119 cases, 35 occurred in vaccinated infants from which 4 had received 3 or 4 oral vaccine doses. For 11 infants paralysis occurred less than one month after vaccination. The virus spread was evaluated (i) just before vaccination in 337 infants or children from June to December 76: 8% carried poliovirus Sabin-like strains (and 18% non polioviruses), and (ii) one month after vaccination in 75 infants: 37% carried poliovirus Sabin-like strains.