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Biomedical subjects

S Obrador

Publications and source records attributed to S Obrador.

At least 19 recordsLinked to original sources

Computerized axial tomography for the diagnosis of cerebral cysticercosis.

Computerized Axial Tomography (CAT) has proved extremely useful for the diagnosis of cerebral cysticercosis. The calcified small, multiple, and scattered cysts provide a typical image on CAT. The collection of non-calcified cysts in the subarachnoid spaces (racemose form) or in the ventricles may produce areas of low density similar to that of the cerebrospinal fluid. The dilatation of the ventricular system, extreme degrees of hydrocephalus, areas of cerebral atrophy, and other related changes induced by the cysts in the subarachnoid spaces are also clearly shown in the CAT. Four personal cases are reported.

Adult↗

Biological factors involved in the clinical features and surgical management of cerebellar hemangioblastomas.

Sixty-five personal cases of cerebellar hemangioblastomas plus others from the literature making a total of 539 cases are reviewed regarding their clinical, biological and surgical aspects. A variable genetic blastomatous growth potential seems to determine the individual biological behavior of these tumors. Retinal angiomatosis, family incidence, multicentric tumors in the central nervous system and in other organs, and some of the so-called recurrences, are considered within this concept.

Adult↗

Surgical management of tumours of the pineal region.

Tumours of the pineal region and posterior part of the third ventricle are rare in European and American series (0.5 to 1% of space-occupying lesions). Personal experience is usually limited and thus cooperative studies or critical reviews of reported cases are necessary to establish therapeutic criteria. We have studied 50 cases from our own material of more than 5,000 brain tumours and intracranial space-occupying lesions operated on during the last 30 years. Another 6 verified cases from Dr. F. Isamat, and more than 200 verified tumours from the literature are added. Histological distribution shows that 24% of the tumours in this locality are benign. The different surgical techniques fro reaching the pineal region are reviewed. The results of palliative operations, or partial removals together with radiotherapy, and total removals are presented in 200 verified cases (Table 1), as well as the results obtained by the different surgical approaches (Table 2). Finally, some conclusions are reached regarding the surgical management of these tumours. More than two thirds are radiosensitive, and in about 50 to 70% good results may be obtained with palliative operations and radiotherapy. The remainder of the pineal tumours (about 20%) should be treated by a direct surgical approach. Recent technical improvements and the use of the surgical microscope have reduced the mortality of pineal surgery and allow verification of the histological nature of the tumour in order to establish more rational treatment.

Brain Neoplasms↗

Heterologous antibodies in human and rat's glioblastoma.

IgG from immunized rabbits was labelled with Fluorescein Isothiocyanate, and conjugated in vitro with human and with rat glioblastoma. After absorption of the antisera with normal brain and liver, a heavy concentration of antibody was found in the rat tumour cells. A great amount of antibody was also found in the human neoplastic cells. The incorporation of this antibody in glioma cells of different rats developing new tumours indicates that transplantation antigens of the H-2 type are not the only ones capable of inducing specific antibody attachment.

Animals↗

Benign cystic tumours of the cerebellum.

In a series of 4.915 surgically treated intracranial tumours and other space-occupying lesions, excluding those due to trauma, the two main groups of benign cerebellar tumours were found to be the astrocytomas (172) and the cystic haemangioblastomas (35). Cerebellar astrocytomas represented 3.5% of all the brain tumour material and 8% of the total number of gliomas. The clinical features are reviewed, and the necessity for surgical and histological verification of the posterior fossa tumours of childhood and youth is emphasized. Preoperative positive contrast ventriculography was usually performed followed by temporal ventricular drainage or ventriculo-peritoneal shunting. Cystic astrocytomas predominated. Radical removal of the solid part of these should be carried out. Total post-operative case mortality varied between 16 and 22% but has become lower in recent years. Good late results varied between 40 and 70%. Angioblastomas of the cerebellum are usually benign tumours, with a cystic component in 70% or more. Usually they represent the most important part of the so-called Lindau complex with possible associated angiomatosis of the retina (von Hippel-Lindau disease) and, more rarely, visceral lesions or haemangioblastomas of the spinal cord. Cystic cerebellar angioblastomas represented 0.7% of all brain tumours. The proportion of male patients was double that of females and the age peak appeared between 30 and 40 years. An increase of red blood cells above five million per mm3 appeared in 9% of our cases. The value of vertebral angiography is emphasized. After emptying the cyst careful removal of the nodule gives a good late result in more than 70% of patients. However, recurrences have been noted in the literature in about 14% of patients due to the frequency of multiple tumour nodules in the posterior fossa (10% in some vertebral angiographic series). Finally, a most careful clinical and radiological search for other lesions in the rest of the body is imperative in these patients.

Adolescent↗

Comatose state maintained during eight years following a vascular ponto-mesencephalic lesion.

A 24-year-old man survived for 8 years after a vascular lesion of the pons and midbrain. During these years a subresponsive comatose state with neurological signs extending from the oculomotor nuclei to the trigeminal and facial nuclei levels was present. A decorticated type of rigidity, with bilateral paralysis of the limbs accompanied by pyramidal signs, was also present. The EEG during the first months showed slow activity which afterwards gradually changed towards fast and alpha activities, maintained in the course of the years. The pathological diagnosis was a fibrous endarteritis, mainly in the territory of the basilar and vertebral arteries. The pons and midbrain, presenting a large cystic infarct, were serially studied to determine the anatomical extent of the lesion. After reviewing other examples from the literature, the clinical features of our case are discussed. The evolution of the EEG is related to different structures of the ponto-mesencephalic region with different functional activities.

Adult↗

Clinical syndromes of arteriovenous malformations of the transverse-sigmoid sinus.

Arteriovenous malformations or fistulae shunting arterial blood from branches of the external and internal carotid and vertebral arteries into the transverse-sigmoid sinus may produce different clinical syndromes. The literature is reviewed with 96 patients including six personal cases. Usually these malformations have a congenital origin and only in 4% of the series was there a previous history of a severe head injury. Clinical groups are defined and the role of angiography assessed. Direct surgical approach with occlusion or removal of the vascular malformation is the treatment of choice. Possible methods of treatment by selective embolization are discussed.

Adult↗