Showing papers by "World Health Organization published in 1971"
235 citations
TL;DR: A ribonucleic acid (RNA)-dependent RNA polymerase has been demonstrated in Kern Canyon virus (KCV) particles and its properties have been characterized and compared with those of vesicular stomatitis virus (VSV).
Abstract: A ribonucleic acid (RNA)-dependent RNA polymerase has been demonstrated in Kern Canyon virus (KCV) particles. The RNA product of the KCV polymerase hybridizes to KCV viral RNA. The properties of this viral enzyme have been characterized and compared with those of vesicular stomatitis virus (VSV). RNA polymerases from both viruses require similar conditions of temperature, pH, and detergent and magnesium concentrations for maximal synthesis of RNA. The RNA polymerase contained in the virion of KCV was more dependent on the presence of a sulfhydryl agent than was the VSV enzyme. Under optimal conditions, the specific activity of the VSV polymerase is about twenty-five times as great as that of KCV.
61 citations
TL;DR: Examining some of the properties of a genetical system in which the genotypic viabilities differ between females and males as well as between the genotypes themselves and showing that, in this situation, it is possible for two distinct stable equilibrium states to exist.
Abstract: FOLLOWING the derivation by Haldane (1924, 1926) of the basic equations describing the changes in gene frequency with random mating for various methods of selection, Owen (1952, 1953) developed the idea of a genetical system in which the genotypic viabilities differ between females and males as well as between the genotypes themselves. In particular, he showed that, in this situation, it is possible for two distinct stable equilibrium states to exist. Some special cases of such a system have been investigated and discussed by Li (1963, 1967), and Bodmer (1965) has analysed the situation in considerable detail; however, apart from these contributions, Owen's interesting model has been given relatively little attention. It is the purpose of this paper to examine, in a general way and on the basis of the equations obtained by Owen, some of the properties of such a system.
34 citations
TL;DR: Four recent meetings have been directed to a study of “standardization” in immunofluorescence, which has meant the attempt to measure the amount or activity of reagents in various immun ofluorescence reactions.
Abstract: Four recent meetings have been directed to a study of “standardization” in immunofluorescence.’ Essentially this has meant the attempt to measure the amount or activity of reagents in various immunofluorescence reactions. For example, the measurement of antinuclear factor is useful in diagnosis of and research on autoimmune diseases, particularly lupus erythematosus. It was thought that the precision and reliability of such measurement would be increased by the use of a standard reference material for this activity. In collaboration with Dr. H. C. Goodman of the Immunology Unit, WHO, Geneva, this division has been developing research standards for a number of human autoimmune antibodies and other materials. When sufficient information has been obtained about any one of these preparations, it will be issued from this division for general use in any country and will be designated a research standard and probably be given a unitage. A research standard is issued in order to serve the needs of an expanding field of research, and the type or quality of standards needed may change as further knowledge is gained. I t is therefore accepted that such standards may need to be replaced or changed from time to time. When further experience has been gained and/or when adequate collaborative studies have been completed, and if the research standard has been shown to meet a real need, information about the research standard may be presented to the Expert Committee on Biological Standardization of WHO, and the material may then be offered to WHO for consideration as an international standard or an international reference preparation. The proposed research standard for antinuclear-factor serum (homogeneous) 661233 is a freeze-dried pooled serum dispensed in glass-sealed ampuls. The source material was a pool of serum from six patients in the United Kingdom and The Netherlands all diagnosed as suffering from lupus erythematosus. The serum pool was poured into glass ampuls on the 2nd of August, 1967, prefroZen, and freeze-dried. On the 7th of August the ampuls were fitted with plastic capillary plugs and the contents were dried to constant weight by secondary desiccation over phosphorus pentoxide at a vacuum of 0.03 torr. On the 10th of August the ampuls were filled with pure dry nitrogen and sealed by fusion of glass. After being tested for pinholes and leaks, the ampuls were stored at 20” C in the dark. During filling, 86 ampuls out of a total of 4,150 were tested for wet weight of coaents. The mean weight was 213 mg, and the range*3.29%. The dry weight of freeze-dried material was estimated in 18 ampuls. The
26 citations
TL;DR: A method of using maximum likelihood to estimate the two unknown parameters, the contact rate and the removal rate, in the general stochastic epidemic, using only the observed interremoval times and the total number of cases occurring is provided.
25 citations
TL;DR: After fractionation of treated virus by velocity centrifugation in a sucrose density gradient, the amount of residual glycop protein recovered in the "core" particle fraction and the extent of contamination of the glycoprotein fraction by other viral components were dependent on the ratio of detergent to viral protein used.
Abstract: Treatment of rabies virus with the nonionic detergent Nonidet P-40 resulted in solubilization of viral lipids and in a preferential release of the envelope glycoprotein. The other viral proteins and the viral ribonucleic acid remained associated in “core” particles sedimenting at a rate similar to that of intact virions. After fractionation of treated virus by velocity centrifugation in a sucrose density gradient, the amount of residual glycoprotein recovered in the “core” particle fraction and the extent of contamination of the glycoprotein fraction by other viral components were dependent on the ratio of detergent to viral protein used.
23 citations
TL;DR: The use of chromic chloride as a coupling reagent has made it possible to coat red cells with rhinovirus protein, shown by immunofluorescence, electron microscopy and immunocolloidal experiments.
Abstract: The use of chromic chloride as a coupling reagent has made it possible to coat red cells with rhinovirus protein. This is shown by immunofluorescence, electron microscopy and immunocolloidal experiments.
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14 citations
TL;DR: Most countries of the world there is evidence of a general regression of syphilis in the last 100 years, notwithstanding intermittent recurrences and epidemic outbreaks associated with wars, economic upheavals or social unrest.
Abstract: most countries of the world there is evidence of a t general regression of syphilis in the last 100 years, notwithstanding intermittent recurrences and epidemic outbreaks associated with wars, economic upheavals or social unrest. This long-term downward trend is illustrated inter alia by data on acquired syphilis reported in the capitals of the Scandinavian countries of Denmark, Norway and Sweden between 1880 and 1969 (Figure 1) A major recurrence of early infectious syphilis took place in most parts of the world during the Second World War, lasting into the immediate post-war period. This phase was followed by a rapid decline which reached an all-time nadir during 1956/58 in most countries (Figure 2). Then came a new period of recrudescence, which still continues although with minor variations in reported cases in some countries in the last 2-3 years. Although cases of serious late syphilis are by no means rare, a decline of late syphilis, including cardiovascular and
TL;DR: The susceptibility to drying of Paracoccidioides brasiliensis growing on sterilized soils, was investigated using 2 strains with different sporulating capacities, and the sporulating strain seemed to resist the deteriorative effect more than did the non-sporulating strain.
Abstract: The susceptibility to drying of Paracoccidioides brasiliensis growing on sterilized soils, was investigated using 2 strains with different sporulating capacities. Decreased fungal viability was noted during the 31 day experimental periods. The sporulating strain surpassed its initial viability at the fifth day when 75 days old culture was used, but not with 135 days old culture. Higher water losses, as observed at the 12th and 31st days, were not tolerated by any of the strains. Some viable particles resisted desiccation for at least 31 days and maintained their pathogenicity for hamsters. Colonies developed on small pieces of wood in the inoculum.A progressive drop of viability of the fungus was observed when exposed to a 2°C. environmental temperature with 100% relative humidity. The sporulating strain seemed to resist the deteriorative effect more than did the non-sporulating strain.
TL;DR: Together with the changing environment, malnutrition in the young will probably change from the pre‐school kwashiorkor‐type to the infant marasmus‐type, and purely nutritional measures cannot be expected to cope with infant malnutrition as it is seen today in the fast‐growing urban agglomerations of the economically underdeveloped countries.
Abstract: Together with the changing environment (urbanisatior of the rural population, industrialization, loss of taditional pattern of life), malnutrition in the young will probably change from the pre‐school kwashiorkor‐type to the infant marasmus‐type. Because of the complex nature of the factors conditioning this change, purely nutritional measures cannot be expected to cope with infant malnutrition as it is seen today in the fast‐growing urban agglomerations of the economically underdeveloped countries. Early malnutrition carries the risk of permanent physical and mental damage. If it is not prevented, affected populations could have a greater impairment of their physical and mental capabilities which could prove to be an unsurmountable obstacle to the progress of the developing nations.
TL;DR: Mechanical hoods preventing inhalation of lead fumes and manufacture of low-cost cells or whole batteries were suggested as possible control measures.
Abstract: Urinary δ-aminolevulinic acid (ALA) levels were measured in 71 indigenous workers who charged batteries. The group consisted of 21 masters, four “free” workers, and 46 apprentices from 25 workshops in two districts of Lagos, Nigeria. Twenty adult male and female medical students of comparable age were controls. Abnormally high urinary ALA levels were found in about half the workers. The mean level was significantly higher than in controls, values being 1.49 mg/100 ml and 0.29 mg/100 ml,. respectively. The highest mean level, 3.60 mg/100 ml, occurred in masters repairing more than three batteries per month, and the highest individual reading, 7.75 mg/100 ml, was one master in this trade for 15 years. Mechanical hoods preventing inhalation of lead fumes and manufacture of low-cost cells or whole batteries were suggested as possible control measures.
TL;DR: The nucleotide composition of the ribonucleic acid of three strains of rabies virus was determined and found to be similar to that of vesicular stomatitis virus as discussed by the authors.
Abstract: The nucleotide composition of the ribonucleic acid of three strains of rabies virus was determined and found to be similar to that of vesicular stomatitis virus.
TL;DR: Since 1957, the World Health Organization has been involved in a programme aimed at developing a uniform, internationally acceptable morphological classification of tumours, which would facilitate communications between those engaged in studies on cancer.
Abstract: Since 1957, the World Health Organization has been involved in a programme aimed at developing a uniform, internationally acceptable morphological classification of tumours, which would facilitate communications between those engaged in studies on cancer.
TL;DR: A freeze-dried preparation of human serum, coded 67/86, has been assessed for use as a standard for measurements ofhuman serum immunoglobulins IgG, IgA, and IgM b y technics of immunodiffusion.
01 Jan 1971
01 Apr 1971
TL;DR: E stato inoltre dimostrato che i topolini timectomizzati producono meno anticorpi dei topolini normali verso l’HSA e che 1a riduzione delia quantita totale di anticorpi e dovuta ad una Riduzione degli anticorri IgGi.
Abstract: Anticorpi verso l’HSA e 1a KLH sono stati dimostrati in tutte e cinque 1e classi immunoglo-buliniche di topolini Balb/c. E stato dimostrato che 1aB. pertussis e piu efficace nello stimolare 1a produzione di anticorpi verso l’HSA che verso 1a KLH e che gli anticorpi IgGi e IgG2b sono stimolati piu di quelli delle altre classi. E stato inoltre dimostrato che i topolini timectomizzati producono meno anticorpi dei topolini normali verso l’HSA e che 1a riduzione delia quantita totale di anticorpi e dovuta ad una riduzione degli anticorpi IgGi.
TL;DR: In this article, the authors used maximum likelihood to estimate the two unknown parameters, the contact rate and the removal rate, in the general stochastic epidemic, using only the observed interremoval times and the total number of cases occurring.
Abstract: This paper provides a method of using maximum likelihood to estimate the two unknown parameters, the contact rate and the removal rate, in the general stochastic epidemic, using only the observed interremoval times and the total number of cases occurring. A goodness-of-fit test is discussed, and the methods described are illustrated by means of data on an actual smallpox epidemic in a restricted community in southeastern Nigeria.
01 Jan 1971
TL;DR: Le déséquilibre de l'apport en oligo-éléments résultant des modifications artificielles du milieu and des denrées alimentaires peut aussi jouer un rôle dans the fonction cardio-vasculaire dans les pays en voie de développement.
Abstract: On a evalue statistiquement la relation entre la mortalite par cardiopathies coronariennes et la consommation per capita des graisses totales et saturees, du saccharose, des sucres simples et complexes, des proteines, et l'apport des calories pour 37 pays. On a trouve une forte correlation positive entre le taux de mortalite, la consommation des graisses totales et saturees, et le niveau de bien-etre materiel. Les correlations avec l'apport des calories et avec la consommation de saccharose et des sucres simples sont moins nettes. Il n'y a presque pas de correlation entre mortalite et consommation des proteines. La correlation negative existant entre le taux de mortalite par cardiopathies coronariennes et la consommation des sucres complexes est vraisemblablement secondaire. Des resultats similaires ont ete obtenus par l'analyse de donnees relatives a la decennie precedente. La correlation entre l'evolution des taux de mortalite par cardiopathies coronariennes et l'evolution des differents facteurs dietetiques au cours des annees dans un pays donne est tres faible. Il semble bien etabli que la consommation exageree des graisses, et surtout des graisses saturees, favorise le developpement des cardiopathies coronariennes, mais une telle tendance ne se manifeste pas dans plusieurs groupes de population, et en particulier dans les pays en voie de developpement. Il faut tenir compte aussi du degre d'activite physique, des tensions psycho-sociales, et du niveau de vie en general. Le desequilibre de l'apport en oligo-elements resultant des modifications artificielles du milieu et des denrees alimentaires peut aussi jouer un role dans la fonction cardio-vasculaire. Les resultats de cette analyse sont examines aussi a la lumiere des observations faites par d'autres chercheurs.