Calcium-binding proteins in the circadian centers of the common marmoset (Callithrix jacchus) and the rock cavy (Kerodon rupestris) brains.

The hypothalamic suprachiasmatic nucleus (SCN) and the thalamic intergeniculate leaflet (IGL) are considered to be the main centers of the mammalian circadian timing system. In primates, the IGL is included as part of the pregeniculate nucleus (PGN), a cell group located mediodorsally to the dorsal lateral geniculate nucleus. This work was carried out to comparatively evaluate the immunohistochemical expression of the calcium-binding proteins calbindin D-28k (CB), parvalbumin (PV), and calretinin (CR) into the circadian brain districts of the common marmoset and the rock cavy. In both species, although no fibers, terminals or perikarya showed PV-immunoreaction (IR) into the SCN, CB-IR perikarya labeling was detected throughout the SCN rostrocaudal extent, seeming to delimit its cytoarchitectonic borders. CR-IR perikarya and neuropil were noticed into the ventral and dorsal portions of the SCN, lacking immunoreactivity in the central core of the marmoset and filling the entire nucleus in the rock cavy. The PGN of the marmoset presented a significant number of CB-, PV-, and CR-IR perikarya throughout the nucleus. The IGL of the rocky cavy exhibited a prominent CB- and CR-IR neuropil, showing similarity to the pattern found in other rodents. By comparing with literature data from other mammals, the results of the present study suggest that CB, PV, and CR are differentially distributed into the SCN and IGL among species. They may act either in concert or in a complementary manner in the SCN and IGL, so as to participate in specific aspects of the circadian regulation.

Percutaneous fetal surgery using epidural catheter: preliminary experience acquired from 24 cases.

OBJECTIVE: The objective of the following study is to report the experience acquired from 24 percutaneous fetal surgeries for cavity drainage using epidural catheter instead of the commercially available catheter. METHODS: Twenty-four percutaneous fetal surgeries for cavity drainage were performed, due to the following anomalies: 13 cases of lower urinary tract obstruction, nine cases of pleural effusion, and two cases of pulmonary cystic adenomatoid malformation type I. In order to verify that catheter adequacy, technical and obstetric complications derived from its use were assessed. Technical complications were difficulty in inserting the catheter and/or its functionality; and obstetric complications were the presence of bleeding, amniotic infection, preterm labor or premature rupture of membranes. RESULTS: The technical complications were the following: difficulty in passing the catheter through epidural needle in one case; one case of catheter drawn back with the needle; two cases of catheter dislodgment; and four cases of non-functionality of the catheter. Among the obstetric complications, there was only one case of preterm labor, and except from one fetus with chromosomal pathology, all the other 23 newborns were alive after 1 week. CONCLUSIONS: The use of the epidural catheter can be seen as a viable alternative to percutaneous surgeries of fetal cavity shunting, due to its low cost and similar complications to the use of the conventional catheter.

[Therapy of the chronic phase of the experimental infection by Trypanosoma cruzi with benzonidazole and nifurtimox]. / Terapêutica da fase crônica da infeccao experimental pelo Trypanosoma cruzi com o benzonidazol e o nifurtimox.

Fifty-eight mice, chronically infected with different T. cruzi strains (Types II and III) were submitted to chemotherapy either with Nifurtimox (Bay 2502) or Benznidazole (Ro 7-1051). Twenty one mice were not treated and were used as infected controls. The duration of infection was from 90 to 400 days. Inocula varied from 1 x 10(4) to 5 x 10(4) blood forms. Treatment lasted for 90 days, doses being 200mg/kg/day during 4 days, followed by 50mg/kg/day for Nifurtimox and 100mg/kg/day for Benznidazole. Parasitological tests (xenodiagnosis, inoculations into baby mice and hemoculture) showed 85.3% negativation for Type II strains and 43% for Type III in animals treated with Benznidazole. As for Nifurtimox, there were 71.4% of parasitological negativation for the animals infected with Type II strains and 66% for those infected with Type III. IFA tests remained positive in 90% of treated and cured animals. Disappearance or marked regression of myocardial and skeletal muscle lesions was seen in the treated and parasitologically negative animals. The conclusion is that the treatment in the chronic phase of T. cruzi infection can result in parasitological cure in a high percentage of cases with regression of histopathological lesions, although with persistence of positivity of the IFA tests.

[Isoenzymatic pattern of Trypanosoma cruzi Y strain after specific chemotherapy]. / Padrao isoenzimático da cepa Y do Trypanosoma cruzi após quimioterapia especifica.

The isoenzyme pattern of the Trypanosoma cruzi Y strain recovered from mice inoculated with 15 x 10(4) blood trypomastigotes and previously treated with either Bay 2502 (Nifurtimox) or Ro 7-1051 (Benzonidazol) was analyzed in the following situations: a) strain resistant to Bay 2502 and again treated with the same drug; b) strain resistant to Bay 2502 and treated with Ro 7-1051; c) strain resistant to Ro 7-1051 and treated with that same drug. Although marked drug resistance was noted in all cases, the isoenzyme pattern of the Y strain for GPI, PGM, ALAT and ASAT remained throughout the same. The pattern was similar to that of the Peruvian strain, which also belongs to the same strain Type of the Y strain, but differed from those of the 21 SF (Type II) and Colombian (Type III) strains. Thus, the appearance of drug resistance in T. cruzi strain was not associated with a change in its isoenzymatic pattern.

Evaluation of chemotherapy with benznidazole and nifurtimox in mice infected with Trypanosoma cruzi strains of different types.

A test was made of the susceptibility of 30 strains of Trypanosoma cruzi to chemotherapy with nifurtimox (Bay 2502) and benznidazole (Ro 7-1051). The strains had previously been classified as type I, II, or III according to their morphobiological and isoenzymic characteristics. Three type I strains, 14 type II strains, and 13 type III strains were studied. Mice were infected with 2 x 10(5) blood forms of these parasites and treated for 90 days with benznidazole or nifurtimox. All the surviving mice were submitted to parasitological tests (direct parasitaemia, xenodiagnosis, inoculation in new-born mice, and haemoculture) and serological tests (indirect immunofluorescence). As the latter remained positive in about 80% of the parasitologically negative animals, the cure rates were based on the more reliable parasitological tests. Type I strains displayed high susceptibility, type II strains showed medium to high susceptibility, and type III strains were highly resistant to both drugs. The fact that a particular strain type, with its own level of susceptibility, usually predominates in a given geographical area may explain the contradictory results after chemotherapy from different endemic areas.

[Behavior of the Y and Peruvian strains of Trypanosoma cruzi in mice, after passage through various media]. / Comportamento das cepas Y e Peruana do Trypanosoma cruzi no camundongo, após passagem em diferentes meios.

The behavior of two strains of Trypanosoma cruzi (Y and Peruvian strains) in experimental mouse infection, after being passed through different conditions of maintainance and cultivation was studied. The conditions were: Warren's acellular culture medium, cryopreservation in liquid Nitrogen, passage through the insect vector and direct blood passage from mice to mice. The parameters considered for comparative study were as follows: parasitemia, mortality rate, maximum survival time, morphology of parasites in peripheral blood, tissue tropism and histopathological lesions. Each experimental group consisted of two sub-groups according to the inocula: 10.000 or 50.000 trypomastigotes. The basic characteristics of the strains remained unchanged. These were macrophagotropism, predominance of slender forms of the parasite in early infection and 100 per cent mortality rate in the acute phase of the infection. However, decrease in the virulence was observed when the culture forms were used or when the infection with low inoculum was used (10.00 forms). Therefore the main biological characteristics of the strains tended to remain the same, regardless of the conditions used for maintainance and cultivation.