Showing papers by "Maastricht University published in 1983"

Productivity and R&D at the Firm Level in French Manufacturing

Abstract: In a companion study to that of Griliches and Mairesse for the United States, we have investigated the relationship between output, labor, and physical and RD it is less so in the time dimension. However, the within-firm estimates are still significant and of a likely order of magnitude.In this respect, they are more satisfactory than the U.S. ones. We show that this is largely due to a better measurement of the variables: (1) the fact that we can use a value-added measure of output instead of sales (or equivalently that we include materials among the factors of the production function); (2) the fact that we can correct the measures of labor, physical capital and output for the double counting or expensing out of the labor, capital and materials components of R&D expenditures.

Infection of laboratory rats with a new cytomegalo-like virus

Abstract: This report described the infection of two strains of laboratory rats with a rativirus (RA-1) with cytomegalovirus-like characteristics. The virus was detected in the spleens and kidneys during the first week post infection. In the salivary glands maximal virus titer was reached at one month post infection; thereafter the titer declined. In Lewis rats virus could be detected in the salivary homogenate of most animals at more than 12 months post infection. In BN rats, in contrast, virus became undetectable in the salivary glands of most animals 5 months after inoculation. However, adminstration of cyclophosphamide or X-irradiation resulted in reactivation of the virus in virtually all animals. Co-cultivation of spleen cells from either latently or chronically infected animals resulted in recovery of virus. The animals developed antibodies and a T-cell mediated virus specific cytotoxicity.

Epilepsy and alcohol : the influence of social alcohol intake on seizures and treatment in epilepsy

Abstract: Summary: People suffering from epileptic seizures are often confronted with restrictions resulting from their attacks, such as exclusion from several professions and from some sports, not being allowed to drive a car, and prohibition of alcohol. Consultation of manuals to trace the literature studies on which this last prohibition was based was unsuccessful since there was no mention of the original research from which it appeared that alcohol was provocative of seizures. To be able to give a well-founded judgment on the influence of social alcohol intake on epilepsy, research was undertaken with epileptic patients who had never before or very sporadically used alcohol. During 16 weeks, twice a week, in a clinical setting, 1–3 glasses of an alcoholic beverage were consumed within a period of 2 h. The examination could be carried out double-blind since the drink that was chosen, vodka, is odorless and cannot be tasted when mixed with orangeade. We concluded the following, (a) No influence of social alcohol use on tonic-clonic convulsions or partial complex seizures is demonstrable, (b) Blood levels of carbamazepine, phenobarbital, and phenytoin are not influenced by alcohol intake. The valproic acid concentration is possibly slightly increased. However, this needs further examination before judgment can be made, (c) Both in frequency bands and in the amount of epileptic activity, no change is produced by alcohol use. RESUME Les gens souffrant de crises epileptiques sont sou-vent soumis a des restrictions a cause de leurs crises: exclusion de certaines professions, interdiction de conduire une voiture, exclusion de certains sports, interdiction de boire de L'alcool. Une recherche biblio-graphique afin de retrouver dans la litterature les etudes sur lesquelles se fondait cette derniere interdiction a ete infructueuse puisque L'on n'a trouve aucune trace L'une recherche prouvant que L'alcool provoquait des crises. Pour pouvoir donner une appreciation valable sur L'influence de L'absorption L'alcool en reponse a des obligations sociales sur L'epilepsie, une recherche a ete entreprise chez des patients epileptiques qui n'avaient jamais bu L'alcool auparavant ou en avaient bu tres sporadiquement. Pendant 16 semaines, 2 fois par semaine, on leur a fait boire 1 a 3 verres L'une boisson alcoolisee pendant une periode de 2 heures. L'essai a pu etre fait en double-aveugle en choisissant un alcool inodore, la vodka, ne pouvant etre decele par le gout quand il est melange a de L'orangeade. Conclusions: (a) II n'a pu etre demontre aucune influence de L'absorption L'alcool en societe sur les crises tonico-cloniques et les crises partielles. (b) Les taux seriques de carbamazepine, phenobarbital et phenytoine n'e-taient pas influencees par cette absorption L'alcool. La concentration en acide valproique pourrait etre le-gerement augmentee, mais ceci ne peut etre encore affirmed (c) L'alcool ne provoque aucun changement dans les bandes de frequence ni dans la quantite L'activitea epileptique. RESUMEN Los enfermos que sufren epilepsyia deben frecuente-mente enfrentarse con las restricciones que resultan de sus ataques: exclusion de varias profesiones, falta de permisos para conducir automoviles, exclusion de algunos deportes y prohibicion de ingerir bebidas al-coho1icas. La consulta de libros y publicaciones, en los que estaultima prohibicion se basa, no ha tenido exito puesto que no aparece mencion alguna de la in-vestigacion original en la que conste que el alcohol provoca ataques. Para emitir un pronunciamiento con fundamento sobre la influencia de la ingesta social de alcohol en la epilepsyia, se han estudiado enfermos epi-lepticos que nunca bebieron alcohol o que lo hacian muy esporadicamente. Durante 16 semanas, dos veces por semana y en ambiente clinico, se administraron de 1 a 3 vasos de bebidas alcoholicas en un periodo de 2 horas. Este estudio puede considerarse como doble ciego puesto que como bebida se utilizo el vodka que es inodoro e insipido si se mezcla con la naranjada. Se llego a las siguientes conclusiones: (a) No se de-mostro influencia alguna del uso social de alcohol sobre las convulsiones t#onico-clonicas o las crisis parciales complejas. (b) Los niveles plasmaticos de carbamaze-pina, fenobarbital y fenitoina no se modificaron con la ingesta de alcohol, observandose un posible incre-mento de los niveles de acido valproico, aunque estos datos necesitan mas examenes antes de ser confir-mados. (c) El uso de alcohol no produjo ninguna al-teracion en la banda de frecuencia ni se aumento la actividad epileptica. ZUSAMMENFASSUNG Menschen, die an epileptischen Anfallen leiden, un-terliegen haufig Restriktionen im Gefolge ihrer An-falle: Berufliche Einschrankungen, Verbote ein Auto zu fuhren, Ausschlus von einigen Sportarten und Verbote des Alkohols. Sichtet man das Schrifttum, um Literaturstudien zu fmden, auf denen das Alkohol-verbot basiert, so ist das wenig erfoigreich, denn die Orginalarbeiten, aus denen hervorgehen soil, das Al-kohol anfallsprovokativ wirkt, werden nicht erwahnt. Um in der Lage zu sein, eine wohl begrundete Ansicht uber den Einflus des “sozialen” Alkoholkonsums auf die Epilepsie abzugeben, wurde eine Untersuchung an epileptischen Patienten angestellt, die niemals vorher oder sehr sporadisch Alkoho! getrunken haben. Wah-rend 16 Wochen–zweimal je Woche–wurden in klin-ischer Umgebung ein bis drei Glas eines alcoholischen Getranks wahrend einer 2 stundigen Periode getrunken. Die Untersuchungen konnten im Doppel-blindversuch durchgefuhrt werden, da das gewahlte Getrank–Wodka–geruchlos ist und nicht gesch-meckt warden kann, wenn es mit Orangade vermischt wird. Folgende Schlusse konnen gezogen werden: (a) Es ist kein Enflus des “sozialen” Alkoholkonsums auf tonisch-klonische Krampfe oder komplexe Partialan-falle zu erkennen. (b) Die Blutspiegel von Carbama-zepin, Phenobarbital, Phenytoin werden durch Al-kohol nicht beeinflusst. Die Valproinsaure-konzentra-tion wird moglicherweise geringfugig erhoht; dieser Punkt bedarf weiterer Untersuchungen ehe ein Urteil abgegeben werder kann. (c) Weder im Frequenzspec-trum noch im Gehalt an epileptischer Aktivitat werden Veranderungen durch Alkohol hervorgerufen.

Symptomatic and asymptomatic rotavirus infections in hospitalized children.

Abstract: . During one year, 871 infants and children admitted to a Dutch paediatric ward were examined weekly for rotavirus. Rotavirus was detected in the stools of 64/129 (49.6%) children with diarrhoea and in 283/742 (38.1%) controls. The incidence of asymptomatic rotavirus excretors increased from 14.5% in infants 0 to 6 months of age to 65.8% in children of 6 years and over, a feature not yet reported. Possible explanations may be the methodology used, the age groups studied, the local hospital (and community) situation and the geographical location. Routine bacteriology revealed enteropathogens in 25.6% of the children with diarrhoea: Salmonellae in 20.9%, Campylobacter jejuni in 3.9%, Yersinia enterocolitica in 1.5%, Shigella sonnei in 0.8% and enteropathogenic E. coli in 0.8% of the patients.

Hemodynamic Actions of Diuretic Agents

Abstract: The blood pressure lowering effect of diuretics in hypertensive disease is well documented. The hemodynamic actions underlying this antihypertensive effect differ in the early phase from the effects observed during long-term treatment. This article first describes new experiments on the hemodynamic effects of three diuretics, viz. hydrochlorothiazide, chlorthalidon and furosemide in conscious, chronically instrumented spontaneously hypertensive rats. This animal model was chosen in view of its good applicability for the study of the hemodynamics of antihypertensive drug action. Results show a marked early fall in stroke volume and cardiac index with all three diuretics. Mean arterial blood pressure was decreased only after a delay of several hours, because of an early large increase in total peripheral resistance. This article furthermore discusses possible mechanisms involved in the long-term return of peripheral resistance close to or below pre-treatment values. On the basis of data in the literature it is concluded that adaptation of baroreceptor reflexes, auto-regulatory responses of the peripheral vascular resistance and enhanced production of endogeneous vasodilator substances play an increasingly important role during the long-term hemodynamic actions of diuretic agents.

Blood pressure response to chronic low-dose intrarenal noradrenaline infusion in conscious rats.

Abstract: Sodium chloride solution (0.9%) or noradrenaline in doses of 4, 12 and 36 micrograms h-1 kg-1 was infused for five consecutive days, either intrarenally (by a new technique) or intravenously into rats with one kidney removed. Intrarenal infusion of noradrenaline caused hypertension at doses which did not do so when infused intravenously. Intrarenal compared with intravenous infusion of noradrenaline caused higher plasma noradrenaline concentrations and a shift of the plasma noradrenaline concentration-blood pressure effect curve towards lower plasma noradrenaline levels. These results suggest that hypertension after chronic intrarenal noradrenaline infusion is produced by relatively higher levels of circulating noradrenaline and by triggering of an additional intrarenal pressor mechanism.

The influence of bilirubin, alcohol and certain drugs on the kinetics of 99mTc-Diethyl IDA (EHIDA) in humans.

Abstract: On the basis of the mathematical analysis of 99mTc-EHIDA hepatobiliary time-activity curves of normal individuals two rate constants, one related to accumulation of radioactivity (uptake) and the other to excretion, were calculated indicating a two-compartmental model. By means of computerized fitting the rate constant of excretion (Kb), the time of maximum uptake (Tmax) and the rate constant of uptake (Ka) were calculated. In severely jaundiced patients (serum bilirubin concentrations>140μmol/l) a markedly decreased or absent uptake of 99mTc-EHIDA was observed. In moderately jaundiced patients a low Kb was invariably observed; in obstructive jaundice due to malignant disease—but not in jaundice of benign obstructive of hepatocellular origin—an increase in Ka was frequently present. This latter finding was not always present, however, and consequently kinetic studies do not unequivocally differentiate between jaundice of obstructive and hepatocellular origin. A markedly increased uptake (a high Ka) was noticed in alcoholics and patients taking phenobarbital and diphenylhydantoin possibly because of drug-induced membrane alterations. When the alcoholics developed hepatocellular injury the Ka converted to normal values. Thus, 99mTc-EHIDA kinetics may be useful in the follow-up of patients with established or suspected alcoholism by virtue of the fact that it appears to be a sensitive monitor of functional changes in hepatocyte plasma membrane properties.

Incessant Dual Supra ventricular Tachycardia in a Child

Abstract: A 5-year-old boy was studied because of incessant supraventricular tachycardia He was shown to have two forms of supraventricular tachycardia each of which could be incessant The interplay between the two tachycardias caused interesting periodic sequences in the surface electrocardiogram Our study illustrates the value of careful analysis of the surface P wave morphology and the usefulness of programmed electrical stimulation of the heart in determining the mechanism of tachycardia