Preliminary results in surgery of Parkinson's disease.

The authors present the preliminary results of 20 patients selected to be operated on between January 1996 and April 1997. These patients presented one of the present indications for stereotactic posteroventral pallidotomy (PVP), such as: rigidity, akinesia/bradykinesia, gait dysfunction, drug induced dyskinesias and tremor. Every patient of this protocol was evaluated by: UPDRS score, Schwab and England scale, Hoehn and Yahr Staging Scale before and after surgery. The results in 3 months showed a remarkable improvement after PVP (P < 0.01) in all functional assessments, except for facial expression, speech and posture. The morbidity was 5%. 5 patients (25%) who were in Hoehn and Yahr 5 underwent a bilateral simultaneous PVP. In 5 patients (25%), who had tremor, during the PVP, VIM thalamotomy was added. These preliminary results, suggest that PVP is highly effective for PD symptoms.

[Image-guided stereotaxic biopsy of central nervous system lesions]. / Biópsia estereotáxica guiada por imagem nas lesões do sistema nervoso central.

In a series of 44 image guided stereotactic biopsy from August 1995 until March 1997, findings were as follows (frequency order). Tumors, glioblastoma was the most frequent. Primary lymphoma and other conditions associated to AIDS. Metastasis, three cases, Vasculites, two cases, Arachnoid cyst, Creutzfeldt-Jakob, cortical degeneration, inespecific calcification (one case each). The age varied from 1 to 83 years. Forty one lesions were supratentorial, two infratentorial, and one was outside the brain (dura and skull) and we used stereotaxy to localize it. There was no mortality and morbidity was 2.3%. The literature is reviewed. We conclude that this procedure is safe and highly diagnostic.

[Stereotaxic brain biopsy in AIDS patients with neurological manifestations]. / Biópsia cerebral estereotáxica em pacientes com AIDS com sintomas neurológicos.

Prospective series showing the importance of computerized stereotactic brain biopsy in the management of AIDS patients neurologically symptomatic and confirmed by images. Patients undergone an algorithm step by step done by their own doctors and referred to us for stereotactic biopsy. Our protocol was opened in August 1995 and closed in December 1996. Twenty patients were biopsied. This protocol is similar to the Levy's one (Chicago IL, USA). We have got diagnosis in all cases. Lymphoma was predominant and followed by toxoplasmosis, progressive multifocal leukoencephalopathy and HIV encephalopathy. We included one patient with diploic giant cells lymphoma. Our mortality and morbidity was zero. By these results we conclude that stereotactic biopsy in AIDS patients is safe and effective.

Insulin-like growth factors (IGFs) stimulate the release of alpha 1-antichymotrypsin and soluble IGF-II/mannose 6-phosphate receptor from MCF7 breast cancer cells.

The growth of hormone-responsive MCF7 human breast cancer cells is controlled by steroid hormones and growth factors. By metabolic labeling of cells grown in steroid- and growth factor-stripped serum conditions, we show that insulin-like growth factors (IGF-I and IGF-II) increase by approximately 5-fold the release of several proteins including cathepsin D, alpha 1-antichymotrypsin, and soluble forms of the multifunctional IGF-II/mannose 6-phosphate (M6P) receptor. Two soluble forms of IGF-II/M6P receptors were detected, one major (approximately 260 kilodaltons) and one minor (approximately 85 kilodaltons) that probably represents a proteolytic fragment of the larger soluble molecule. IGFs increased receptor release in a dose-dependent fashion with 50-60% of newly synthesized receptor released at 5-10 nM IGFs. The release of IGF-II/M6P receptors correlated with the levels of secreted cathepsin D in different human breast cancer cells or in rats stable transfectants that are constitutively expressing variable levels of human cathepsin D. IGFs had a stronger effect on IGF-II/M6P receptor release, whereas estradiol treatment preferentially enhanced the release of protease and antiprotease. We thus demonstrate that in human breast cancer cells, IGFs not only act as strong mitogens but also regulate release of alpha 1-antichymotrypsin, IGF-II/M6P-soluble receptor, and cathepsin D; three proteins that potentially regulate cell proliferation and/or invasion.

Thyroid hormone promotes transient nerve growth factor synthesis in rat cerebellar neuroblasts.

Primary cultures of cerebellum from 5-day-old rats indicated that proliferating neuroblasts synthesize and release nerve growth factor (NGF). Since NGF promotes DNA synthesis in these cells, our findings demonstrate that the early developing cerebellum is a suitable physiological model for studying the autocrine mitogenic action of NGF. Thyroid deficiency led to a greater reduction in the NGF content of the cerebellum than of the olfactory bulbs or hippocampus. Cerebellar NGF mRNA was also very sensitive to hormone deprivation. Physiological amounts of thyroid hormone stimulated both the mitotic activity and NGF production of cultured cerebellar neuroblasts. A lack of thyroid hormone is known to markedly alter cell formation in the cerebellum where postnatal neurogenesis is highly significant, in contrast to the olfactory bulbs and hippocampus. Taken together, these results suggest that the hormonal control of cell formation in the cerebellum is, at least partly, mediated by the autocrine mitogenic action of NGF. The thyroid hormone could temporally regulate the transient NGF synthesis by cerebellar neuroblasts directly and/or through its ontogenetic action, and hence all the NGF-dependent trophic effects.

Nerve growth factor enhances DNA synthesis in cultured cerebellar neuroblasts.

The cerebellar neuroblasts in primary cultures from five-day-old rats bore NGF receptor immunoreactivity, suggesting a potential responsive to NGF. At low plating density, NGF was found to enhance DNA synthesis in these cells in a dose-dependent manner. As these cells synthesize NGF, one possibility to account for the lack of response of neuroblasts plated at high density is that the amount of endogenous trophic agent produced in this culture condition is sufficient to ensure an optimal effect. The results demonstrate that premitotic neuroblasts in the CNS, as well postmitotic neurons, are responsive to NGF. At the early stage of its development, the cerebellum therefore appears to be a very good autocrine model of NGF action.