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Biomedical subjects

G Bravo

Publications and source records attributed to G Bravo.

At least 91 records · Page 5Linked to original sources
PubMed1989

The protective action of R56865 against ouabain-induced intoxication in rat heart isolated atria and ventricles.

The action of R56865 has been examined on the contractile effects produced by ouabain concentrations interacting with high (3 microM) and low (300 microM) affinity digitalis receptors on electrically stimulated ventricular strips isolated from rat. R56865 1 microM reduced the increase in resting tension produced by ouabain 300 microM and left unalterated the inotropic effect evoked by ouabain 3 and 300 microM that was reduced by higher concentrations (3 and 6 microM) of R56865. The action of R56865 was also studied on ouabain-induced intoxication in electrically stimulated and spontaneously beating atria of rat. On electrically stimulated (3 Hz) whole atria, R56865 0.3 microM reduced the maximal increase in resting tension produced by ouabain 300 microM and delayed the time to onset of the ouabain-induced arrhythmias but did not affect ouabain's inotropic effect. Higher concentrations of R56865 were required to reduce the inotropic effect of ouabain. The protective action of R56865 against ouabain-induced intoxication was most pronounced on spontaneously beating atria where it reduced spontaneous rate of beats. Experiments in electrically driven left atria indicated that only a part of the protective effect of R56865 could be related to its bradycardic action. The effect of R56865 was also examined on ouabain-induced inhibition of sodium pump in human red blood cells. R56865 6 microM did not modify the inhibition produced by ouabain (from 0.3 to 10 nM), this indicates that the protective action of R56865 against ouabain-induced intoxication is not due to an interaction with the inhibitory effect of ouabain on sodium pump.

Animals↗
PubMed1989

Preparation of adrenal medullary tissue for transplantation in Parkinson's disease: a new procedure. Technical note.

The authors describe a technique by which adrenal medullary tissue can be easily dissected from the adrenal cortex. The method involves perfusion with Locke's modified buffer, dissection of adrenal gland in buffer free of calcium or magnesium, and storage in a culture medium before implantation into the caudate nucleus of patients with Parkinson's disease. This method seems to increase the viability and purity of adrenal medullary tissue. The results obtained in 15 parkinsonian patients implanted with perfused adrenal medulla indicate the potential value of this technique.

Adrenal Medulla↗
PubMed1988

Symptomatic glial cysts of the pineal gland.

Two cases of symptomatic glial cysts of the pineal gland are reported. An origin similar to that proposed for paraventricular glial cysts of the brain is accepted. These unusual lesions could be considered in the differential diagnosis of cystic pineal masses.

Adult↗
PubMed1987

Cavernomas of the central nervous system: clinical syndromes, CT scan diagnosis, and prognosis after surgical treatment in 25 cases.

We present our clinical experience and the results of surgical management with 25 cavernomas of the CNS, treated in our hospital in the last 10 years. The location of the lesion assessed by clinical and CT scan examinations, proved to be the most significative factor determining the prognosis of cavernomas of the CNS, after surgical removal. The symptoms started in most of the cases in the third decade of life. 19 cases were located in the cerebral hemispheres and produced three well defined clinical syndromes: Irritative syndrome (seizures) present in 70% of the cases. Space-occupying lesion syndrome (20%) and haemorrhagic syndrome (10%). The remaining six cases were located within the basal ganglia, brainstem, pineal region, cerebellum and spinal cord, showing a progressive course. CT scan studies were performed on 24 cases. The characteristic image of a cavernoma is represented by a moderately hyperdense nodule with discreet contrast uptake. Calcification was observed in and around the lesions in 33% of the cases. Perilesional hypodensities suggestive of brain tissue atrophy were noted in 22% of the CT scans. On the other hand, 12% of cerebral hemisphere cavernomas showed atypical CT scan images that suggested an erroneous diagnosis of cystic gliomas. Radical surgical removal was performed in all cases. The postoperative results varied according to the location of the lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Posterior fossa epidermoid cysts.

The authors present their clinical and surgical experience with 18 posterior fossa cholesteatomas, including three cases with atypical CT scan appearances that corresponded to calcification, haemorrhage or malignant change into an epidermoid carcinoma, respectively.

Adolescent↗
PubMed1986

Clinical and CT scan assessment of benign versus fatal spontaneous cerebellar haematomas.

We have studied 15 cases of spontaneous intracerebellar haematomas in 9 males and 6 females. A significant correlation between the clinical presentation and the CT scan features of benign and fatal haemorrhages of the cerebellum is presented. Diagnostic computerized tomographic studies were performed in a mean interval of 31 hours after the initial symptoms. 60% were diagnosed and treated in less than 24 hours; 11 patients had haematomas larger than 3 cm, and 5 (45%) of these cases died with evidence of irreversible brain-stem damage. Twelve (80%) showed compression of the fourth ventricle, 9 (60%) obliteration of the brain-stem cisterns and 8 (53%) ventricular dilatation. 8 cases were treated with surgery; 50% of them showed neurological improvement, including two cases with signs of brain-stem compression. 7 patients who were treated conservatively were followed closely with repeated CT scans, which showed that resolution of the mass effect and isodensity of the haematomas larger than 3 cm (73%), hydrocephalus (45%) and intraventricular haemorrhage (40%). Smaller haematomas without CT scan evidence of obliteration of the brain-stem cisterns or hydrocephalus had a better outcome.

Adult↗
PubMed1986

Traumatic false aneurysms of the middle meningeal artery.

The authors report a rare case of traumatic false aneurysm of the middle meningeal artery associated with a delayed contralateral extradural hematoma. The extradural hematoma was evacuated, and the pseudoaneurysm was removed to avoid delayed rupture. The literature on traumatic aneurysms is reviewed.

Adult↗
PubMed1986

Choroid plexus papilloma with chondroma: case report.

The authors report the successful total removal of a rare intracranial tumor in the right lateral ventricle of a 15-year-old girl with epileptic seizures. Histopathological examination showed a benign tumor formed by mature cartilage and choroid plexus papilloma. From our review of the literature, a mixed tumor with these histological features has not been reported previously in this location. The diagnosis, surgical approach, etiology, and prognosis of this lesion are discussed.

Adolescent↗
PubMed1984

Intracranial gangliogliomas.

Five cases of intracranial gangliomas in their clinical, diagnostic and surgical aspects are presented. In four cases we arrived at the diagnosis by CT-scan, which showed in all of them, calcified lesions without a mass effect. Total surgical resection was performed in four cases, and there is no evidence of recurrence either clinically or in the CT-scan after different follow-up periods. Although infrequent, these kinds of tumours should enter the differential diagnosis at any time when there a calcified mass exists in children or young patients with a long history of seizures. In our experience, seizures were the most important sign in all cases with supratentorial gangliogliomas.

Adult↗
PubMed1983

Estrogen- and progesterone-receptor proteins in intracranial tumors.

Estrogen and progesterone receptors have been measured in 13 intracranial tumors (eight meningiomas, two acoustic neurinomas, one primary tumor of neuroectodermal origin, one giant-celled glioblastoma, and one metastasis of carcinoma). Evidence is provided of the presence of progesterone receptors in meningiomas (87.5%). We could not find clear evidence of estrogen receptors in any tumor of this series. Presence of progesterone receptors in meningiomas suggests an explanation for the greater incidence of these tumors in women and their rapid growth during pregnancy.

Adult↗
PubMed1983

Meningiomas of the posterior fossa.

Clinical and surgical results in 38 cases of posterior fossa meningiomas are presented. All cases have been diagnosed and operated upon during the last 12 years in this department. We have identified five locations for these tumors: cerebellopontine angle, cerebellar convexity, tentorium, peritorcular, and clivus. Clinical features of these tumors and their surgical management are described. Sixty-eight percent of the cases presented have been diagnosed by computed tomography scan. All cases were operated upon with a 15.78% postoperative mortality; 36.85% of the patients remained symptom-free; 26.32% suffered mild neurological deficits; and 21.05% suffered severe neurological deficits. Total resection had been accomplished in 84.22% of the cases. Computed tomography scans allow earlier and more accurate diagnosis of these tumors, which in our opinion has modified the surgical results for the better. We discuss our findings and compare them with other published articles.

Adult↗
PubMed1983

Chordoma.

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Adult↗
PubMed1983

Cavernomas of the brain.

Our clinical and surgical experience with 16 cases of cavernous hemangioma (cavernoma) of the brain is presented. In 50% of the cases, symptoms appeared during the 3rd decade of life. The clinical picture included seizures in 50% of the cases and a brain tumor-like syndrome in 37.5%, and 12.5% of the cases began with an intracerebral hemorrhage. In our series females predominated over males by 2:1. Computed tomographic (CT) scanning is the best procedure for the diagnosis of cavernomas. However, exact preoperative diagnosis of these lesions is infrequent because cavernomas are generally accepted to be very rare. A slightly hyperdense nodule, poorly enhanced after contrast administration, is the prominent feature on the CT scan. A small, hypodense zone surrounding the lesion and calcifications within the nodule are also found. An excellent result after operation was obtained in all cases of cavernoma located in the brain hemispheres. In deeply placed cavernomas (basal ganglia or brain stem), the surgical prognosis is doubtful, and features such as the size of the lesion and its anatomical location are important.

Adult↗