Screening for inborn errors of metabolism in high-risk children from Rio de Janeiro, Brazil.

From 1988 to 1995, our laboratory at the Institute of Chemistry of the Federal University of Rio de Janeiro, in Rio de Janeiro, screened 2650 samples from 2000 high-risk patients (mostly children) for Inborn Errors of Metabolism (IEM). Chemical tests, various chromatographic techniques and enzyme assays were performed on urine, plasma and in some cases, cerebrospinal fluid (CSF). A total of 145 cases of IEM (7.2%) was identified. These were related to: the metabolism of amino acids (41) and carbohydrates (17), organic acids (7), lysosomal enzymes (61), membrane transport system (16), metals (2), intestinal disaccharidases (1) and porphyrin metabolism (3). Furthermore, a relevant number of patients with abnormal findings is still under investigation. Biochemical results and clinical symptoms are presented and the importance of reference laboratories for the detection of IEM is stressed.

[Tumors of the brain stem: anatomo-pathologic study of 35 necropsy cases]. / Tumores do tronco cerebral: estudo anatomopatológico em 35 casos de necrópsia.

Brain stem tumors are rare and are usually treated without histological diagnosis. Its incidence varies in literature between 1.09% and 17.5% of all cerebral tumors. The objective of our study is to present a casuistic of these tumors in 28500 necropsies performed from 1952 till 1985 at the Department of Pathology, Santa Casa Hospital, São Paulo. We emphasize neuropathologic aspects, and compare our cases with those of other series. Also, we point out those tumors which are most frequent in this region, with the aim of possibly contributing to a better therapeutic approach. We used some clinical data and pathological diagnosis, and localized the tumor in the brain stem. Its microscopic diagnosis was determined according to the World Health Organization criterion. Among 428 intracranial tumors observed, 35 were localized in the brain stem. Intrinsic tumors and metastasis were included, and excluded those tumors which infiltrated the brain stem. Greatest incidence occurred in the first decade and cerebral edema was the predominant cause of death. Preferential topography was in the pons and the most frequent tumor was glioblastoma multiformis (19 cases). Metastasis ranked second (9 cases), being mostly from lungs. Some authors oppose tumor biopsy in this region because of high surgical risk. We do not agree with this opinion. We believe that the diagnosis of glioma is important to rule out the characteristics of malignancy. We can not leave without considering the diagnosis of other pathologies which can cause expansion in the brain stem. Therapeutical approach can be more adequate with the histological diagnosis of glioma or of other possibilities as shown here.

Seizures in Chédiak-Higashi syndrome. Case report.

Chédiak-Higashi syndrome is a rare hematological disease characterized by increased fusion of cytoplasmatic granules. Neurological symptoms occur in approximately half of the patients. We describe the clinical, eletrophysiological, hematological and radiological findings in a girl who had Chédiak-Higashi syndrome and seizures.

Lipoma of the right atrium.

The patient is a 54-year-old asymptomatic male with a tumor in the right atrium that was diagnosed on transesophageal echocardiography and confirmed as a lipoma of the right atrium on computerized tomography. The patient underwent surgical repair with extracorporeal circulation. The tumor was resected, and its base of implantation in the atrium was repaired with a flap of bovine pericardium. The diagnosis of lipoma was confirmed on histopathological examination. Locating of the tumor with the aid of transesophageal echocardiography was very useful in the strategy of cannulation of the venae cava for installation of the circuit of extracorporeal circulation. The patient had a good postoperative evolution.

Mouse kidney trehalase: purification and properties.

Trehalase (E.C.3.2.1.28) was isolated from mouse kidney and purified to homogeneity. The enzyme was solubilized with n-octanol and activated by freezing and thawing before precipitation with ammonium sulfate. A 1700-fold purification was achieved by chromatography on DEAE-cellulose, SP-Sephadex, followed by gel filtration on Sephadex G-200. Only a single form of enzyme activity was shown throughout the fractionation as confirmed by gel electrophoresis of the final preparation. The enzyme was specific for trehalose and its estimated molecular weight by filtration on Sephadex G-200 was 73,000. The Km for trehalose was shown to be 2.67 x 10(-3)M and the optimum pH was in the range of 5.5-5.6. We have also shown that the optimum temperature of the enzyme is 60 degrees C, but in the absence of substrate, thermal inactivation occurred at 55 degrees C.