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Biomedical subjects

J P Albert

Publications and source records attributed to J P Albert.

At least 19 recordsLinked to original sources

Worldwide prevalence of lentivirus infection in wild feline species: epidemiologic and phylogenetic aspects.

The natural occurrence of lentiviruses closely related to feline immunodeficiency virus (FIV) in nondomestic felid species is shown here to be worldwide. Cross-reactive antibodies to FIV were common in several free-ranging populations of large cats, including East African lions and cheetahs of the Serengeti ecosystem and in puma (also called cougar or mountain lion) populations throughout North America. Infectious puma lentivirus (PLV) was isolated from several Florida panthers, a severely endangered relict puma subspecies inhabiting the Big Cypress Swamp and Everglades ecosystems in southern Florida. Phylogenetic analysis of PLV genomic sequences from disparate geographic isolates revealed appreciable divergence from domestic cat FIV sequences as well as between PLV sequences found in different North American locales. The level of sequence divergence between PLV and FIV was greater than the level of divergence between human and certain simian immunodeficiency viruses, suggesting that the transmission of FIV between feline species is infrequent and parallels in time the emergence of HIV from simian ancestors.

Amino Acid Sequence

Putative site for the acquisition of human herpesvirus 6 virion tegument.

The virion of human herpesvirus 6 (HHV-6) contains a very distinct tegument layer, occupying the space between the nucleocapsid and the virion envelope. Ultrastructural analyses of thymocytes infected with HHV-6 revealed the presence of intranuclear spherical compartments, approximately 1.5 microns in diameter, in which tegumentation seems to take place. These compartments, termed tegusomes, were bounded by two membranes and contained ribosomes, consistent with their derivation by cytoplasmic invagination into the nucleus. Capsids located within the nucleus outside the tegusomes were all naked, while those located in the cytoplasm were uniformly tegumented. In contrast, capsids present inside the tegusomes contains teguments of variable thicknesses. In addition, nucleocapsids were documented in the process of budding into the tegusomes. We thus suggest that the tegusomes represent a cellular site in which HHV-6 virions acquire their tegument.

Cell Nucleus

[Effect of x-ray contrast media on the blood coagulation and fibrinolysis systems].

The intravenous application of x-ray contrast media during arteriographies resulted in a small, statistically significant, however clinically and biologically not relevant prolongation of the thromboplastin time and of the thrombincoagulase time. Contrast media applied for the examination of the kidneys and of the gall bladder did not induce any comparable changes of coagulation parameters. In vitro addition of iodinated contrast media to citrated plasmas was inhibitory to the coagulation process. Further analysis demonstrated that contrast media did not influence coagulation by enzyme inhibition but by inhibition of fibrin polymerization. Euglobulin lysis time was not only shortened by diagnostic applications of contrast media but also by other diagnostic procedures (gastroscopies, rectoscopies, laparoscopies) which involved physical exercise and thereby activation of the fibrinolytic system. Finally it is discussed that thrombotic complications following angiographies might be induced by the punction and injury of the vessel with the liberation of thrombokinase and subendothelial collagen.

Angiography

[Does low-dosage heparin treatment require serial haematological controls? (author's transl)].

Blanket serial controls are not necessary in low-dosage heparin treatment. It would, in any case, be difficult under normal clinical conditions and would run counter to the whole conception of low-dose heparin treatment. However, in problem cases with an increased thrombo-embolic risk, sensitive methods for monitoring the heparin effect are recommended. A study on 150 patients has indicated that the most sensitive method is the use of chromogenic substrates. Thrombin time, using low-concentration thrombin solution of 1.5 NIH units/ml, thrombelastogram and activated partial thromboplastin time are less sensitive. Antithrombin III levels should be determined in all cases of increased heparin tolerance. With reduced antithrombin III levels and higher body weight an increase of the standard dose from 5000 U.S.P. units heparin t. i. d. subcutaneously to 7500 U.S.P. units t. i. d. should be considered.

Antithrombins

[Plasma aldosterone and electrolytes in primary and secondard aldosteronism (author's transl)].

Plasma aldosterone levels and the serum electrolytes potassium, sodium and magnesium of 38 patients with healthy adrenals were determined. Under physiological conditions there were no significant correlations between these parameters. In two patients with an aldosterone producing adenoma of the adrenals (syndrome of Conn) we found very low levels of potassium and low levels of magnesium. The levels of sodium lay in the upper normal range. Plasma aldosterone levels are raised strongly. After resection of the tumors the mentioned parameters normalized. In 16 patients with cirrhosis and ascites we generally found values of aldosterone, potassium, sodium and magnesium which lay in the lowest normal range. Under treatment with spironolactone the aldosterone levels raised and reached values which are characteristical of the syndrome of Conn. Potassium raised to the upper normal range, magnesium raised significantly, sodium diminished slightly.

Adenoma

[Investigations concerning the hypothalamic-hypophysial regulation of aldosterone secretion (author's transl)].

In 17 patients with retrospectively healthy adrenals we performed a LHRH-test, a TRF-test and an ACTH-test in the short modification. Additionally we determined plasma aldosterone and renine levels. Concerning the LHRH-tests and the TRF-tests we did not find any differences on the aldosterone values. Concerning the ACTH-tests in the short modification we found an increase of the aldosterone values which resembled that of the cortisol levels (increase of cortisol 104.7%, increase of aldosterone 93.3%). The renin values remained unchanged. Therefore the plasma aldosterone levels are modified in accordance with the cortisol levels by hypophysial influences.

Adrenocorticotropic Hormone

[Plasma aldosterone after rest and exercise: normal values, type of distribution, dependence upon age and sex (author's transl)].

We determined plasma aldosterone levels of patients with healthy adrenals after rest (n = 80) and exercise (n = 30) using a radioimmune assay with highly specific antibodies. The obtained normal values had a log-normal distribution. The normal values did not show any differences regarding sex and age. At rest they ranged between 50 pg/ml and 190 pg/ml, after exercise between 110 pg/ml and 310 pg/ml.

Adolescent

[Sudan-savanna and rain-forest onchocerciasis in West Africa: an epidemiological problem (author's transl)].

A Sudan-savanna and a rain forest onchocerciasis have been described in West Africa. These two patterns of onchocerciasis have in common many epidemiological features but in hyperendemic areas there is a very essential difference between the two. In savanna the prevalence of serious ocular lesions and blindness due to onchocerciasis are much higher than in forest. Therefore attempting to explain these differences five groups of factors (or working hypothesis) are reviewed: --factors related to the vectors; --onchocerca-simulium couples; --different Onchocerca volvulus strains; --factors related to the human-host; --other varied factors: nutritional factors, concomitant ocular infections, luminousness of savanna, periods of transmission... A critical examination of these hypothesis brings to the conclusion that according to our present knowledge the main difference between savanna and rain-forest onchocerciasis may be due to degrees in pathogenicity of different strains of O. volvulus but these hypothesis have not been proved formally. More the part of concomitant factors (co-factors), themselves related to bioclimactic zones must not be ruled out.

Adolescent

[Mode of action and control of "low dose heparin" (author's transl)].

Investigating the mechanism of action of "low dose heparin" it could be shown that this type of anticoagulation--in addition to other mechanisms--inhibits the contact phase of the intrinsic coagulation system. Thus "low dose heparin" would be directed against the hypercoagulability that arises via increased contact activation of the intrinsic system by inflammatory or degenerative processes of the vessel walls. Further the biological significance of "low dose heparin" was demonstrated by a prolongation of the half life of 125J-fibrinogen. In general a laboratory control of "low dose heparin"-prophylaxis is not required. In patients with an increased "tolerance" for heparin, however, the determination of the thrombin time with a thrombin-solution of low concentration (1 N.I.H.-unit/ml) might be useful to indicate whether the dosage of heparin has to be increased or not.

Arterial Occlusive Diseases

[Epidemiology of human and animal brucellosis in western Africa. The results of six studies in the Ivory Coast, Upper Volta, and Nigeria].

Brucellosis has a two-fold importance in public health: the transmission of the disease to man by contact with animals or ingestion of raw milk is of direct importance; of indirect importance is the loss of animal protein. The authors have carried out ten epidemiological investigations in different bio-climatic zones of West Africa. More than 120 villages were evaluated. In each village, 100 persons were chosen at random and all or part of the animal population was also studied. Three tests were used for man: the melitin intradermal reaction, the sero-agglutination test of Wright and the complement fixation test. Three tests were used for the animals, the "ring-test" and the same serologic tests used for humans. The results indicated that brucellosis in animals exists in all regions but with varying rates. The bovine species seems to be the most contaminated. The enzooty becomes more widespread towards the South. Human brucellosis was not found to be of great importance in the regions mainly populated by farmers. Shepherds and their families in these zones, however, were found to have been infected. The highest percentage of infected humans was found in the sahelian zone (in Dori 30% of the intradermal reactions and 10% of serologies were positive for humans) in spite of a rather low infection rate among animals (6%-8% ring-tests positive among cattle). The majority of the population are shepherds and close cohabitation with animals is common. A basic dietary constituent is milk, which is often consumed raw (variable according to ethnic group), and provides the principal source of animal protein. Adults were found to have a significantly higher intradermal reaction rate in most of the regions studied. The positivity rate was higher in men than in women. In non-pastoral areas the shepherds and their families had a singificantly higher positivity rate than the general population. Ethnic differences were found. Also considered in this paper are intradermal reaction sizes, the relation between intradermal and serologic results, the modes of human transmission of the disease, and the relationship between human and animal forms of brucellosis.

Adult

[Bases for control of arthropod vectors: I--Definitions, bioecology of vectors (author's transl)].

Arthropoda form the most diversified and multitudinous phyllum of the animal kingdom. In this "arthropod world", the authors give the respective position of the arthropoda: a) detrimental to crops, b) venomous and noxious for human being, but mainly those who are vectors of human diseases, say about a hundred species. Biological, ecological and environmental main features of the most important arthropod vectors of human tropical diseases are reviewed. Various factors acting on the relation between pathological agent and vector and between vector and man are considered. Importance and complexity of entomological surveys are emphasized with, as a consequence, the necessity of specialized medical entomologists to manage them.

Acari

[Current aspects of human salmonellosis in Upper Volta. Study carried out at Centre Muraz (Bobo-Dioulasso) from 1966 to 1977: isolation of 1,013 Salmonella strains].

In a long term research programme of Centre Muraz a study on salmonellosis in Upper Volta has been carried out, at Bobo-Dioulasso, from 1966 to 1977. Investigations have been executed at Centre Muraz, at Bobo-Dioulasso hospital and at Ouagadougou hospital. All the strains of Salmonella were collected at Centre Muraz by biology laboratory, which is a reference service for Upper Volta. This country is include; among the 32 countries which collaborate with W.H.O. and are involved in the world epidemiological surveillance of salmonellosis. For twelve years, 1.013 Samonella strains have been isolated : 1.002 from man and only 11 from animals. The study, which is presented, deals with human salmonellosis. These diseases have been considered from several points of view : bacteriology, clinic, treatment and epidemiology. The various origins of these strains have been specified. The different technics used for diagnosis are discussed briefly : hemoculture (for typhoïd fever and few other types of salmonellosis), coproculture (for "minor" salmonellosis) are the most common and useful methods. Among the 1.013 which have been found, S. typhi is highly predominant (67 p. 100). In the other hand, S. dublin and S. typhi murium play an important role in the various serotypes which occured. A total of 76 serotypes, already known elsewhere, but found for the first time in Upper Volta, have been observed. Three new serotypes have been described : S. bobo, S. kua and S. farakan. As far as clinical problem is concerned, two main aspects are frequent : either typhoid fever syndrome (caused by S. typhi and, scarcely, by other germs, like S. dublin) or gastrointestinal infections, which present different forms and are more or less severe. Up to now, one single strain of S. typhi murium, suspected to be resistant to chloramphenicol has been isolated in 1977. Such a problem would need more complete research in a reference centre. Otherwise, no epidemic multiresistance has been observed. Checking strictly all the strains by systematic antibiograms is now absolutly essential in the plan of a steady epidemiological surveillance.

Adult

[Initial observations in Upper-Volta on 41 serotypes of Salmonella isolated at Muraz Center].

Among 186 Salmonella strains isolated at the Muraz Center from 1966 to 1976, representing 45 serotypes, the authors describe 41 serotypes identified for the first time in Upper-Volta, 3 of which constituting new serotypes: S. bobo, S. kua, S. farakan. A few remarks show the significance of Salmonella circulation in a west-africa area where the incidence of bacterial enteric diseases is a constant problem of public health.

Burkina Faso

[Bases for control of arthropod vectors: II--Present means (author's transl)].

A review of the present means of control of arthropod vectors in which the authors consider:--individual means aimed at the prevention of bites by utilizing clothes, repellents, mosquito nets and insecticide sprays,--collective means which are either physical, biological or chemical. Physical means are specially used for water control either in "peridomestic actions" or in large scale campaign's related to rural or industrial development scheme. Actually biological means are represented only by larvivorous fishes. The chemical control is the most important, its various requisites, and techniques are given.

Animals