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Biomedical subjects

F Simon

Publications and source records attributed to F Simon.

At least 199 records · Page 11Linked to original sources
PubMed1990

[Classification of retroviruses].

The retroviridae comprise a large number of viruses. In both nature and laboratories these viruses are associated with numerous diseases, including rapid or long latency malignancies, neurological disorders and immunodeficiency. The replication cycle is characterized by integration of the viral DNA into the host's genome after the reverse transcriptase copied the viral RNA into DNA. The discovery of human retroviruses had a late start. It was not until 1980 that the first oncovirus, the human T-leukaemia virus 1 (HTLV-1), was identified. The human immunodeficiency viruses (HIV-1 and HIV-2), belonging to the lentivirus subfamily, cause AIDS. Several simian virus, called simian immunodeficiency viruses (SIV) and related to HIV-1 and/or HIV-2 have been identified in monkeys and chimpanzees.

Animals↗
PubMed1990

[HIV infection and malaria].

In sub-Saharian Africa, most HIV seropositive subjects carry either haematozoa (especially children) or antimalarial antibodies. Despite a transient decrease in cell-mediated immunity during malarial paroxysms, Plasmodium falciparum malaria does not seem to influence the course of the HIV infection. Paroxysms may be slightly more frequent or slightly more severe in HIV seropositive subjects, but they raise no diagnostic or therapeutic problem. Some cases of HIV contamination have been attributed to the blood transfusions required by malaria-induced anaemia. Prophylactic measures include early chemotherapy of malaria and detection of dangerous blood donors, if necessary by quick tests. Modern HIV tests avoid most of the false-positive reactions sometimes observed during malaria.

Africa, Northern↗
PubMed1990

[Effect of the weather on acute hospital admissions. Observations at a neurologic clinic].

In 1,286 acute admissions to a neurological department in 1987/88, the relationship between admission rate and the continuously recorded meteorological parameters air pressure, temperature, and humidity, together with their differences over 24 hours (previous day and next day), as well as subjective weather effects, were submitted to factor analysis. No correlation was found between admission rate and absolute meterological parameters, but there was a relationship between admission rate and 24-hour differences, which was age-dependent and decreased from younger to older patients. This was considered to show that in the elderly, the usual course of their disease is more decisive than any influences of the weather. This contrasts with the results of demoscopic polls that show an increase in weather-dependent complaints with age.

Adolescent↗
PubMed1990

Lampbrush W and Z heterochromosome characterization with a monoclonal antibody and heat-induced chromosomal markers in the newt Pleurodeles waltl: W chromosome plays a role in female sex determination.

Two subsets of lateral loops scattered on lampbrush chromosomes of the newt Pleurodeles waltl were characterized. One group was identified by labelling with a monoclonal antibody (A1). The second group was identified by the ability of the loops to be induced by heat treatment. Three loops of each subset were mapped on a short region of the two homologues of lampbrush bivalent IV. These regions appear to be heteromorphic because the six loops are always heterozygous. Five loops are found on one homologue and the sixth on the partner. The distribution of these markers in phenotypic females corresponding to the three sexual genotypes ZW, WW and ZZ shows an absolute correlation of the five loop group with the W chromosome and of the other loop with the Z chromosome. Therefore the heteromorphic regions of the homologues correspond to the differential segments of the heterochromosomes. The identification of a trisomic ZZW female suggests that the W chromosome bears female sex determinants. Furthermore the results show that heat induces loop development and that under normal conditions giant loop development is influenced by the sexual genotype.

Animals↗
PubMed1990

Prospective study of the occurrence of monoclonal gammapathies following bone marrow transplantation in young children.

We have prospectively studied the occurrence of monoclonal serum immunoglobulins in 38 recipients of BMT. Patients were young children with primary immunodeficiencies (n = 31), other inherited diseases (n = 4), leukemia (n = 2), or aplastic anemia (n = 1). Twenty-nine received an HLA-nonidentical marrow and nine an HLA-identical marrow. Serum monoclonal immunoglobulins were detected by the immunofixation method. Monoclonal immunoglobulins were found in 26 patients. Monoclonal components were more frequently detected in patients with primary severe T cell deficiencies (21/25) rather than in the other patients (6/13). In 7 of 29 recipients of HLA-nonidentical transplants, versus 0 out of 9 recipients of HLA-identical transplants, serum monoclonal immunoglobulins were found associated with a B lymphocyte proliferation syndrome due to an Epstein-Barr virus infection. In this group, monoclonal immunoglobulins were detected early, prior to the onset of the clinical syndrome. The simultaneous occurrence of several monoclonal immunoglobulins was more frequent in these patients, while monoclonal immunoglobulin concentrations increased faster, especially those of IgM isotype. These characteristics may allow in patients at risk (recipients with primary T cell immunodeficiencies and receiving HLA-nonidentical transplantation) an earlier diagnosis of B lymphocyte proliferative syndrome that may eventually lead to early and more efficient therapy.

Bone Marrow Transplantation↗
PubMed1990

Varicella in patients infected with the human immunodeficiency virus.

In a retrospective study of 421 patients infected with human immunodeficiency virus, 15 (3.5%) had varicella. Twelve patients had a typical varicella. Complications were as follows: profuse eruption, 6; hemorrhagic eruption, 1; hepatitis, 5; and pulmonary involvement, 1; 1 patient developed an intravascular disseminated coagulation and died of varicella. Three patients with acquired immunodeficiency syndrome, having a history of varicella, presented with an atypical form of varicella with a small number of disseminated cutaneous poxlike lesions; 1 of these patients experienced three relapses of atypical varicella. Assay of serum antibodies to varicella zoster virus showed that, while typical varicella was the primary varicella zoster virus infection, atypical varicella was a reactivation of varicella zoster virus infection. Acyclovir was given to 11 patients and vidarabine to 1 patient. The one patient who died and the one who suffered a relapse had received acyclovir. Thus, varicella in patients infected with human immunodeficiency virus may be complicated and even lethal. Atypical forms of varicella could be, as is the case with herpes zoster, a reactivation of endogenous varicella zoster virus.

Adolescent↗
PubMed1990

Target animal safety test of a dexamethasone-prednisolone combination in horses.

The target animal safety of a dexamethasone-prednisolone combination was studied on 12 horses divided into two groups of six each. One group of horses received the therapeutic dose of the combination (25 mg/animal dexamethasone pivalate and 75 mg/animal prednisolone) and the second group was given the threefold dose of it. The preparation was administered intravenously for 2 consecutive days. For assessment of safety a wide range of clinical, haematological, biochemical and urine variables were tested as laid down in the guidelines of the FDA. All horses treated by the therapeutic or the threefold therapeutic doses of the preparation remained in good health throughout the entire study. No signs of clinical abnormalities occurred in either group. The physiological variables tested failed to reveal any significant alteration as a consequence of the medications. Of the haematological and biochemical parameters leucocyte, neutrophil, eosinophil and lymphocyte counts, aspartate aminotransferase activity, glucose, phosphor, total and conjugated bilirubin and creatinine concentrations were significantly affected in both groups. In some animals a transient glucosuria occurred. From the direction and magnitude of these changes it was concluded that they did not reflect any toxic actions of the preparation. Nevertheless, the combination is to be administered only with exact therapeutic indications and the uncontrolled misuse of it must be avoided.

Animals↗
PubMed1990

[The effect of monensin, tiamulin and the simultaneous administration of both substances on the microsomal mixed function oxidases and on the peroxide formation in broilers].

The influence of Monensin, Tiamulin and the simultaneous administration of the two substances on the microsomal, mixed function oxidases was studied on cockerels. Monensin was seen to cause a slight depression in the amount of cytochrome P-450 and cytochrome b5 as well as in the activities of aniline-p-hydroxylase, p-nitrophenol-hydroxylase and p-nitroanisole-O-demethylase. Tiamulin induced a moderate increase in the amount of cytochrome P-450 and in the activities of aniline-p-hydroxylase, p-nitrophenol-hydroxylase and aminopyrine-N-demethylase. The combined administration of monensin and tiamulin resulted in marked induction of the microsomal enzymes; the amount of cytochrome P-450 reduced by metyrapone or carbon monoxide increased 2.5 or 2-times, respectively, and the activities of the tested microsomal hydroxylases and demethylases showed also an expressed increase. At the same time the formation of lipid peroxides also markedly increased and the GSH concentration was reduced. In conclusion, the results of the investigations indicate that the simultaneous application of monensin and tiamulin cause a marked induction of the drug-metabolizing microsomal enzymes and a significant increase in the lipid peroxide formation.

Animals↗
PubMed1989

Interpretation of antibodies reacting solely with human retroviral core proteins in western equatorial Africa.

Out of 4176 sera from asymptomatic adults originating from Chad, equatorial Guinea and Gabon tested for HIV-1 antibodies, 146 (3.5%) were positive by an enzyme immunoassay (EIA). By Western blot (WB), 20 (0.5%) were positive, i.e. with antibodies to the core and the envelope proteins, 96 (2.3%) were indeterminate, i.e. with antibodies to the viral core proteins only and 30 (0.7%) were negative. On testing for HIV-2 by WB, two of the 96 indeterminate sera had antibodies to the HIV-2 envelope glycoproteins. Two complementary tests were used: a radioimmunoprecipitation assay (RIPA) and a HIV EIA recombinant assay (ENVACOR) to check 53 of these indeterminate sera. Forty-one were positive for the p25 protein in RIPA, of which 34 were negative in ENVACOR; six were positive for core proteins only and one was positive for envelope and core proteins using this assay. Twelve of the 53 indeterminate sera were negative in RIPA, of which 11 were negative and one positive for core proteins in ENVACOR. Thus, 42 of these sera remained indeterminate even after the two additional tests which did not allow a distinction between retroviral infection or non-specific reactions. We were able to isolate an unusual HIV-1 virus from lymphocyte cultures of two subjects presenting antibodies directed only against the core proteins.

Africa, Western↗
PubMed1989

[Not Available].

Explore the source record for details and available documents.

France↗
PubMed1989

Clinical investigations of medetomidine in dogs.

Experiments with 3 doses of medetomidine (20, 40 and 80 micrograms/kg, iv. and im., respectively) were carried out on 90 dogs of 16 breeds in the Small Animal Surgery of the University of Veterinary Science, Budapest. Changes in hematology as well as in AST, AP, BUN, creatinine were studied. Medetomidine administered iv deepened the sedation and lengthened tranquillization dose-dependently. After im administration the sedative effect was still dose-dependent, but the duration of its clinical effectiveness could not be lengthened significantly. The development of the sedation could however, be quickened. The iv administration increased the level of analgesia in proportion to dosage; the im application could change the level of pain-killing effect of the drug, but could not lengthen it. According to the laboratorical determinations, regardless of the dosage and the route of application, medetomidine did not affect the AST and AP enzyme activities, or the BUN and creatinine values.

Adrenergic alpha-Agonists↗