Can improvements in water supply reduce childhood diarrhoea?

The effects of improving the water supply on the incidence ofdiarrhoea in 1096 children from three neighbouring villagesof the Kirotshe rural health district. Northern Kivu, Zairewere investigated. Two of these villages had piped water, whilethe third village had no such facility. Children aged underfour years on registration were visited fortnightly for oneyear. Median diarrhoea incidence per two weeks proved to besignificantly lower in the two intervention villages than inthe control village. In the two intervention villages, mediandiarrhoea incidence per two weeks was halved in children wholived in households located less than a five-minute walk fromthe public standpipe, or in households using more than 50 litresof water a day. The association between diarrhoea incidenceand facility use did not differ after stratification by socioeconomicvariables. These findings underscore the fact that children in householdsthat use standpipes are exposed to a lower risk of diarrhoea.Therefore, it is important to stress that those in charge ofthe planning and implementation of water supply interventionsinvestigate the access to, and use of, water amongst the targetpopulation.     

Leukaemic non-Hodgkin's lymphomas with hyperdiploid cells and t(ll;14)(ql3;q32): a subtype of mantle cell lymphoma?

The present study describes five patients with leukaemic non-Hodgkin's lymphoma (NHL) detected on the basis of particular morphology and cytogenetic findings. With respect to histological, immunological and cytogenetic features these NHL are closely related to mantle cell Iymphoma/intermediate differentiated lymphocytic lymphoma. However, the presence of unusual large cells associated with the t(ll;14)(ql3;q32) translocation and numerical chromosome changes, in the near triploid or near tetraploid range, could delineate a particular subtype of mantle cell lymphoma.     

Cerebrospinal fluid histamine levels are decreased in patients with narcolepsy and excessive daytime sleepiness of other origin

Histaminergic neurons of the hypothalamic tuberomammillary nucleus constitute a major wake‐promoting system. In animals, cerebrospinal fluid (CSF) histamine levels are increased during wakefulness and after sleep deprivation and decreased during sleep. An involvement of the histamine system in human disorders has not, to our knowledge, been reported. We measured hypocretin‐1 and histamine levels in the lumbar CSF of 28 patients with and without excessive daytime sleepiness (EDS) as assessed by the Epworth Sleepiness Scale (ESS). There were 10 patients with EDS (ESS > 10, mean ESS = 14). Diagnoses included narcolepsy (n = 4), idiopathic hypersomnia (n = 2), sleep apnoea (n = 2) and multiple sclerosis (n = 2). Three patients were treated with stimulants. Their mean CSF histamine was 258 ± 159 PM. There were 18 patients without EDS (ESS < 9, mean ESS = 5). No patients were treated with stimulants. Their mean CSF histamine was significantly higher (624 ± 481 PM, P = 0.007). There was a significant inverse correlation (r = ?0.48, P = 0.02) between ESS and both CSF histamine and hypocretin‐1 levels. These observations suggest that narcolepsy and EDS of other origin are associated in humans with lower CSF histamine levels and therefore with a reduced activity of the wake‐promoting histaminergic neuronal system.     

Spontaneous Echo Contrast in Patients with Sinus Rhythm but Poor Atrial Contraction

Spontaneous echo contrast in the left atrium in patients with sinus rhythm is unusual. The aim of this study was to assess the mechanism of this phenomenon and any clinical implications. We studied 90 consecutive patients using transesophageal echocardiography. Spontaneous echo contrast was seen within the left atrium in 29 patients, 11 of whom were in sinus rhythm. In patients with spontaneous contrast and sinus rhythm, the underlying diseases were: mitral insufficiency (5), mitral stenosis (1), mitral prostheses (2), congestive cardiomyopathy (1), hypertrophic cardiomyopathy (1), and heart transplantation (1). Spontaneous echo contrast tended to be faint in this group (10/11). The left atrium was enlarged in all, with subjective poor atrial contraction. Furthermore, reduced mitral A wave suggested an impairment of left atrial contractility. Holter monitoring demonstrated paroxysmal atrial fibrillation in five subjects. Two patients had a history of transient ischemic attacks. No atrial thrombus was observed in any patient. The demonstration of spontaneous echo contrast with transesophageal echocardiography does not seem uncommon even in patients in sinus rhythm. This may indicate an increased risk of thromboembolism.     

Sudden Cardiac Death, Implanted Defibrillation, and Clinical Electrophysiology

A mere 25 years ago, the technique of external defibrillation became the starting point for the development of clinical electrophysiology by permitting routine use of endocavitary programmed electrical stimulation of the heart without undue risk. Major advances in knowledge of clinical arrhythmias and the understanding of their mechanisms were, thus, permitted. Mirowski's implanted defibrillator also constituted a major breakthrough therapeutically; unfortunately, however, some 10 years later, it has not yet induced similarly hoped for consequences in terms of progressing knowledge concerning lethal arrhythmias, largely due to the absence of Holter functions in the implanted devices. As a result of this, in our opinion, better established therapeutic indications are still needed. The reasons for the present situation, we believe, may be partly technical but are conceptual as well. The key point is that even the clear demonstration of the great practical efficacy of a therapeutic tool does not exempt us from the obligation of determining the mechanisms of this effect.     

Dose-dependent effects of a nitric oxide biosynthesis inhibitor on hyperdynamic circulation in two models of portal hypertension in conscious rats

The role of nitric oxide (NO) in the hyperkinetic circulation in portal hypertension has not been clearly elucidated. Different doses of NO inhibitors, haemodynamic values and experimental conditions might explain the discrepant results. The aim of the present study was to investigate the acute effects of a specific biosynthesis inhibitor of NO, Nω-nitro-L-arginine (L-NNA), on the systemic and splanchnic circulation in normal conscious rats and rats with portal hypertension due to either partial portal vein stenosis or secondary biliary cirrhosis. The administration of L-NNA (15 to 960 (μg.kg^-1.min^-1) induced a significant dose dependent increase in arterial pressure which was not different among the three groups of rats. Following an acute and maximal vasopressive dose of L-NNA (1 mg.kg^-1.min^-1) cardiac index decreased more in portal vein stenosed and cirrhotic rats (-45 ± 3% and -45 ± 2%, respectively) than in normal rats (-31 ± 2%), and systemic vascular resistance increased more in the two groups of portal hypertensive rats than in normals (+161 ± 13% and + 154 ± 10% vs + 85 ± 6%, respectively). L-NNA caused a greater decrease in portal tributary blood flow in portal vein stenosed and cirrhotic rats (-63 ± 4% and -55 ± 4%, respectively) than in normal rats (-45 ± 6%). Similarly, the increase in portal territory vascular resistance was significantly more marked in portal vein stenosed and cirrhotic rats (+ 337 ± 62% and +214 ± 24%, respectively) than in normal rats (+153 ± 23%). Portal pressure did not change. Following the acute administration of L-NNA, no significant difference in splanchnic and systemic haemodynamics were noted between portal vein stenosed and normal rats, except for portal pressure. In cirrhotic rats, splanchnic and systemic values remained different from normal rats. This study confirms that NO plays a role in the haemodynamic changes in portal hypertension, and shows that NO inhibitors have a dose-dependent effect in conscious portal hypertensive rats.     

Anti TSH-receptor antibodies in pregnant patients with autoimmune thyroid disorder

Summary. The study was designed to test further the usefulness of the radioreceptor assay of thyroid stimulating hormone (TSH) binding inhibitory immunoglobulins (TBH) and the bioassay of thyroid stimulating antibodies (TSAb) or TSH stimulated cAMP response inhibitory antibodies (TBkAb) in the prediction of neonatal thyroid dysfunction. Of 63 pregnant women with a current or past history of autoimmune thyroid disorder, 11 (one with active and six with a past history of Graves'disease and four with autoimmune thyroiditis) gave birth to a baby with transient hyper or hypo-thyroidism. Only high maternal titres (which could persist after partial thyroidectomy) of anti TSH-receptor antibodies (TRAb) led to neonatal hyperthyroidism. Both types of assay were able to detect the antibodies responsible for transitory neonatal autoimmune thyroid disease. TBH values reflectcd TSAb titres so that there was a significant correlation between the results of both assays in women with Graves' disease and in neonatal sera. Positive TBII and TBkAb activities were present in 5 of the 28 women with autoimmune thyroiditis. Therefore, when TBII is positive, the functional characterization of the antibodies warrants the use of the bioassay.     

Dynamic Electrophysiology of Ventriculoatrial Conduction: Implications for DDD and DDDR Pacing

CAZEAU, S., ET AL.: Dynamic Electrophysiology of Ventriculoatrial Conduction: Implications for DDD and DDDR Pacing. The behavior of ventriculoatrial conduction (VAC) during exercise remains unknown. In order to determine its characteristics and the consequences it might have on dual chamber pacemaker technology and programming, 17 patients underwent an electrophysiological study (EPS) of atrioventricular conduction (AVC) and of VAC during a protocol including three steps: supine rest, upright position, and finally during cycloergometric exercise; the measurements were done at progressively increasing pacing rates. During a preimplantation EPS, Wenckebach points AVC-W and VAC-W and conduction times, AVCT and VACT (as a function of pacing rate), were measured in ten consecutive patients using temporary leads and an external device. In another study, AVCT, VACT, AVC-W, and VAC-W were measured by telemetric recordings under identical conditions in seven patients implanted earlier with a DDD pacemaker. A 1/1 VAC was observed in 7/17 patients (41%) at rest, and in 13/17 patients (76%) at the end of the protocol; VAC was never observed in 4/17 patients [23%], but occurred in six of the ten patients initially free, three standing at rest and three on exercise. For all patients, the VAC behavior remained of “nodal” type, indicated by a progressive increase in VACT as pacing rate rose up to the VAC-W point. Neither the existence of exercise-induced VAC nor the maximal VACT-W could be predicted from AVC or VAC data obtained at rest. However, at the same pacing rates, standing up and exercise induced a shortening effect on VACT, and improved the VAC-W by an average of 33%. These results suggest that the electrophysiological behavior of VAC does not obey any general rule and cannot be predicted individually. It would thus appear unwise to base pacemaker mediated tachycardia (PMT) protection solely on long postventricular atrial refractory period (PVARP) programming in DDD patients. This work also revealed the potential risks of a rate responsive auto-adaptive PVARP algorithm as proposed in certain new devices.