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Biomedical subjects

L Calegari

Publications and source records attributed to L Calegari.

36 records · Page 2Linked to original sources
PubMed1982

[Experimental pathogenicity of isolates of Nocardia asteroides, Nocardia brasiliensis and Nocardia caviae from different sources].

The experimental pathogenicity of 14 isolates of Nocardia brasiliensis, 15 of N. asteroides, and 5 of N. caviae was investigated for the white Swiss mice inoculated intraperitoneally and in the foot pad, and for the guinea-pig and the hamster (Mesocricetus auratus) both inoculated intratesticularly. The guinea-pig was remarkably sensitive to N. asteroides, with an apparent relationship between pathogenicity and thermotolerance, confirming previous observations. Mice were in general less susceptible to this species. In both guinea-pigs and hamsters it was possible to observe typical granules with or without clubs. N. caviae was highly pathogenic for the guinea-pig and the hamster but no mycetomas were produced in the mice inoculated in the foot pad. Isolates of N. brasiliensis from natural sources were scarcely virulent for the different animals. Those of human origin produced significant lesions in the mice inoculated intraperitoneally with granules. Foot pad inoculation of mice with N. brasiliensis caused mycetomas in several animals.

Animals↗
PubMed1981

Diagnosis of human rotavirus infections: comparison of an electrophoretic method, a modified complement fixation test and electron microscopy for rotavirus detection.

A modified complement fixation test and a counter-immuno-electrophoresis on cellulose acetate were compared to electron microscopy, in detecting Rotavirus from stool specimens. Out of 75 samples from patients with acute gastroenteritis, 40 per cent yielded positive results. The main advantages of the above two methods in routine diagnosis are discussed.

Complement Fixation Tests↗
PubMed1979

Paracoccidioidal infection in the wife of a patient with paracoccidioidomycosis.

Three agar immunoprecipitin techniques (double immunodiffusion, immunoelectrophoresis and immunoelectroosmophoresis-immunodiffusion) made with paracoccidioidin and serum of a paracoccidioidomycosis patient's wife, permitted us to observe a specific band in 6 successive samples of blood taken from the wife over a period of 21 months. The case represents an example of a subclinical paracoccidioidomycosis infection that is usually diagnosed in its disseminated, progressive form. Three possible sources of infection are discussed. But an interhuman contagion appears to be the most feasible.

Antibodies, Fungal↗
PubMed1978

[Comparative study of immunoelectrophoresis (IEF) and immunoelectroosmophoresis-immunodiffusion (IEOF-ID) used in the diagnosis of paracoccidioidomycosis].

Immunoelectroporesis (IEF) and immunoelectroosmophoresis-immunodiffusion (IEOP-ID) (1) were comparatively used in the diagnosis of 16 patients with mycologically proved paracocidioidomycosis. In IEF, 5 different precipitin arcs were found and identified with arabic numbers. Arc. '1', cathodic, present in all the patients, is assimilated to specific arcs previously described by other authors. In IEOP-ID both 'cathodic' and 'anodic' arcs were observed in all the sera. A high number of precipitin arcs were revealed by IEOP-ID technique in comparison to IEF in every case. This should be due to the presence of cathodic arcs 'I' and '2' of the immunoelectrophoregram at both sides of the IEOP-ID preparate.

Antigens, Fungal↗
PubMed1978

Lysogenic conversion in Klebsiella pneumoniae: system which requires active immunity regulation for expression of the conversion phenomenon.

We have previously described Klebsiella pneumoniae MirM7b, which, although stably lysogenic for the inducible and nondefective phages FR2 and AP3, is not immune to superinfection by these same viruses. MirA12b, a strain which is lysogenic for FR2 and AP3 and immune to superinfection, has been derived from MirM7b. The sensitivity of this strain and that of the nonimmune parent to several bacteriophages have been compared in this work. It has been found that, whereas MirM7b is sensitive to coliphages P1, T3, T7, and phiI, MirA12b is fully resistant to all of them. It is shown that phages FR2 and AP3 convert Klebsiella strains to resistance to coliphage P1 and coliphages T3, T7, and phiI, respectively, and cause loss of surface antigens in lysogenic cells. To determine such a conversion, both FR2 and AP3 require expression of immunity to superinfection. This explains the differences that exist between MirM7b and MirA12b in both phage sensitivity and surface antigens. Hypotheses are presented to explain the peculiar need for an active superinfection repressor to express lysogenic conversion.

Antigens, Bacterial↗
PubMed1978

The peculiar behaviour of coliphage P1vir mutants on restricting hosts.

The sensitivity of two vir coliphage P1 mutants, to the host-specificity systems A, K, RII, and B of Escherichia coli, and to the newly identified host-specificity systems Mir and 59 of Klebsiella pneumoniae has been studied. Both 1 vir phages were completely resistant to the E. coli K, but were restricted 10(-5) by the B, mir and 59 systems. The P1 parent, on the contrary, was restricted 10(-2) by all of the above mentioned hosts. The possible role of phage coded proteins in the altered sensitivity of the vir strains has been studied by analysing the sensitivity of both P1, and P1vir to the various systems in the presence of chloramphenicol. Protein synthesis inhibition by chloramphenicol did not significantly influence the sensitivity of P1 and P1vir to various restricting hosts. It is concluded that the altered sensitivity of vir mutants depends on the different affinities of the mutated phage DNA sequence for the enzymes of the various restriction and modification systems. The possibility that the phage repressor contributes to the regulation of the restriction and modification enzymes is also discussed.

Chloramphenicol↗
PubMedDate not supplied

Treatment of human cutaneous sporotrichosis with itraconazole.

Eighteen adult white male patients with cutaneous sporotrichosis were treated with itraconazole following different daily dose schemes. Cure was obtained in all cases after periods of 15-75 days (median 44 days) with total doses between 3.1 and 14.8 g (median 8.4 g). No serious side effects were observed and no relapses occurred in the follow-up period of between 1 and 26 months (median 14.7). These results show that itraconazole represents a safe and effective drug for the treatment of sporotrichosis. Comparison with other studies leads us to consider a daily dose of 200 mg as the most appropriate. A concomitant warming of the affected limbs should be recommended.

Adult↗
PubMedDate not supplied

[Feeding pattern of Triatoma rubrovaria (Blanchard, 1843) (Hemiptera, Triatominae) in peridomiciliary habitats, of a rural area of Uruguay].

It has been studied the feeding patterns of Triatoma rubrovaria (wild triatominae bug, and intradomiciliary secondary vector of T. cruzi) in a rural area of "La Bolsa" (Department of Artigas). Agar double diffusion test were used for analyze the blood meal, from 120 insects, which were confronted to 13 antisera. It has 251 identify blood meals, and the most frequently was mammalian host (73%), but it has a variable source of feeding (mammals, birds, reptiles and cockroach), including humans rate 8% of the total. The identify of haemolimphe as feed, place this triatominae bug as an intermediary vector between predator and haematophagous. The most usual mammals are dasypodides and bovines. The frequence of human blood meal near the dwellings, shows its potentiality as vectors. Therefore, the peridomicile is an area of interaction between, domestic, wild and sinantropic host. The trypanosomic infection's rate at peridomiciles was lesser those at wild areas.

Animals↗
PubMedDate not supplied

Ecology of Triatoma rubrovaria (Hemiptera, Triatominae) in wild and peridomestic environments of Uruguay.

This paper describes population structure, spatial distribution and habitat selection of wild and peridomestic populations of Triatoma rubrovaria (Blanchard, 1843). Field studies were carried out at Las Piedras and La Bolsa in the Northern Department of Artigas, Uruguay. A semicircular sampling area, divided in seven or eight triangular sectors was sequentially examined from October 1990 to November 1991. At Las Piedras (typical wild habitat) 1063 T. rubrovaria bugs were collected from 84% of the rocky outcroops ("pedregales"). Abundance varied by season peaking in October-November (spring). Throughout the year, most of the population was made up of third, fourth and fifth instar nymphs; adults were found from October to March. In the peridomestic environment of La Bolsa, however T. rubrovaria was less common and showed a more irregular instar distribution. Colonized ecotopes, were those close to houses. In both sites T. rubrovaria was mainly associated with the geckonid Homonota uruguayensis and the cockroach Blaptica dubia.

Animals↗
PubMedDate not supplied

[Seroprevalence of T. cruzi infection in 6- and 12- year-old school children from three Uruguayan endemic departments].

The last national survey on seroprevalence of T. cruzi human infection in Uruguay, showed a 3.4% in adults from endemic areas. Since 1983, antivectorial actions of the control program have been carried out continually. In consequence, household infestation by Triatoma infestan, the main vector of T. cruzi in Uruguay, decreased in all endemic areas and was completely eliminated in some of them. The objectives of the present work are to evaluate the new seroepidemiological situation. A representative sampling of rural and urban population was undertaken, to include six and twelve year-old school children from three departments: Artigas, Rivera and Tacuarembo. The whole sample included 4,722 school children, evaluated by the indirect immunofluorescence (IFI) test for Chagaś disease. The seroprevalence of T. cruzi infection in the six year-old group was 0.3% in Artigas, 0.6% in Rivera and 1.0% in Tacuarembo. The seropositive children with seropositive mothers support the possible congenital transmission.

Animals↗