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H Moreno

Publications and source records attributed to H Moreno.

96 records · Page 6Linked to original sources
PubMedDate not supplied

Septal fetal tissue transplants restore long-term potentiation in the dentate gyrus of fimbria-formix-lesioned rats.

Two groups of Sprague-Dawley male rats received bilateral aspirative lesions of the fimbria fornix under chloral hydrate anesthesia. One group (n = 9) received no further treatment (lesioned). In the second group (n = 8), a piece of septal fetal tissue, obtained at day E15-16, was implanted into each lesion cavity (transplanted). A third group consisted of shamlesioned rats (controls, n = 14). Two months after the operations, a recording electrode was implanted in the hilar region of the dentate gyrus of each animal, and a bipolar stimulating electrode was implanted in the perforant path. Long-term potentiation at 400 Hz was induced and followed for two hours. FF-lesioned rats showed an impaired potentiation of the field excitatory post-synaptic potential, which rapidly declined to basal levels within 15 minutes. The transplanted rats showed a normal potentiation of this parameter, similar to that seen in the control animals. A decrease in choline acetyltransferase activity in the hippocampi of the lesioned animals showed a tendency toward recovery after septal fetal tissue transplantation. In all the dorsal hippocampal areas of the lesioned animals, acetylcholinesterase histochemistry showed an almost complete loss of enzymatic activity, which was partially restored by the transplants. The improved synaptic plasticity in the transplanted animals might be related to septal transplant-induced recovery of mnemonic functions.

Acetylcholinesterase↗
PubMedDate not supplied

[Effect of reinfection on the development of rats infected with Trypanosoma cruzi].

The present study was undertaken in order to demonstrate that reinfection could modify parasitemia, serum antibodies, electrocardiographic patterns and/or myocardial lesions already observed in a rat model. Experimental groups IG: rats infected at weaning with 1 x 10(6) T. cruzi; RG: same as IG plus reinoculations each 30 days until completion on day 150; IG1: 51 day old infected rats; C: controls. A high parasitemia was detected in IG and RG until day 20 showing a tendency to become negative on day 30. No parasites were observed in RG after the first reinoculation which could not be attributed to the old age of the host since there was no parasitemia in IG1. Xenodiagnosis were negative in all three groups. Serum antibodies were not significantly modified in RG in comparison with IG, except for 7S antibodies, since RG showed higher titres in some days under study. No distinct patterns of basal ECG were observed in infected rats. The ajmaline test reduced the heart rate (HR) showing no treatment dependence. The PR, QaT and QRS were significantly lengthened in all groups regarding the basal one (p less than 0.05), except for the QaT in C. Besides, the PR and QaT alterations were greater in the infected rats (p less than 0.05). There was also present a wide variety of electric axis orientations, regarding the basal value, accompanied by morphological changes more evident in the RG. The incidence of cardiac lesions histologically detected in the infected group was significantly higher than in C (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Ajmaline↗
PubMedDate not supplied

[Intraventricular neurocytoma. Report of 2 cases and analysis of the therapeutic possibilities].

Intraventricular or central neurocytoma is a recently described unusual benign cerebral tumor. Common features include: predominant occurrence in young adults, septum pellucidum and fornix localization, and signs of intracranial hypertension due to obstructive hydrocephalus. Histopathologically, this tumor is characterized by a uniform neoplastic cell population with features of neuronal differentiation. Radiologic findings such as calcification, well-circumscribed tumor mass and confinement to the lateral and third ventricles are common. An anterior transcallosal neurosurgical approach yielded good outcomes. Radiotherapy should be considered for residual and recurrent neurocytomas. However, the radiation sensitivity of intraventricular neurocytoma has not been established and further studies are required to determine susceptibility to irradiation.

Adult↗