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Biomedical subjects

C C Leite

Publications and source records attributed to C C Leite.

16 recordsLinked to original sources
PubMed2001

Parkinsonism after glycine-derivate exposure.

This 54-year-old man accidentally sprayed himself with the chemical agent glyphosate, a herbicide derived from the amino acid glycine. He developed disseminated skin lesions 6 hours after the accident. One month later, he developed a symmetrical parkinsonian syndrome. Two years after the initial exposure to glyphosate, magnetic resonance imaging revealed hyperintense signal in the globus pallidus and substantia nigra, bilaterally, on T2-weighted images. Levodopa/benserazide 500/125 mg daily provided satisfactory clinical outcome.

Antiparkinson Agents↗
PubMed2001

Diffusion-weighted MR imaging of cystic lesions of neurocysticercosis: a preliminary study.

Neurocysticercosis is an endemic disease in some developing countries. It has pleomorfic clinical and imaging findings, which are variable from patient to patient. In this preliminary note, we studied the magnetic resonance (MR) diffusion-weighted images (DWI) of sixteen patients presenting with cystic lesions of this disease diagnosed by clinical and laboratorial findings. All the lesions had hypointense signal and the similar apparent diffusion coeficient (ADC) values as the cerebrospinal fluid (CSF).

Adult↗
PubMed2000

Magnetic resonance imaging of the temporal bone in patients with Ménière's disease.

Ménière's disease (MD) is still controversial in several aspects. The vestibular aqueduct, the osseous channel that carries the endolymphatic duct and sac, has previously been studied by tomography and computed tomography, with shortening and narrowing of this structure observed. These findings are apparently correlated to the development of the endolymphatic hydrops present in MD and related to its episodic symptoms. In studying the endolymphatic duct, the key structure in the pathology of this disease, magnetic resonance imaging (MRI) studies of the temporal bone were performed in 12 patients with unilateral MD and in 9 bilateral cases; the results were compared with images obtained from 30 normal ears. The endolymphatic duct appeared to be statistically less visible in MD patients, with no difference between symptomatic and asymptomatic ears in the presence of unilateral disease. No relationship was found between visualization of the endolymphatic duct and time of evolution or response to clinical treatment in these cases. The distance from the posterior semicircular canal to the posterior temporal border was found to be bilaterally reduced in MD. The authors conclude that although the demonstration of endolymphatic hydrops "in vivo" is not yet possible by MRI, some features can be observed that can support a clinical hypothesis of MD.

Adult↗
PubMed2000

Radiation therapy and high-dose tamoxifen in the treatment of patients with diffuse brainstem gliomas: results of a Brazilian cooperative study. Brainstem Glioma Cooperative Group.

PURPOSE: The efficacy of radiation therapy (RT) combined with tamoxifen (TX) was tested in patients diagnosed with diffuse brainstem gliomas in a multicenter trial. PATIENTS AND METHODS: TX was administered orally (maintenance dose: 200 mg/m(2) per day) along with conventional local RT and then continued for 52 additional weeks. Survival, tumoral radiologic response, and toxicity were evaluated. Compliance was assessed using pharmacokinetic measurements. RESULTS: Of 29 patients, 27 completed RT (median dose, 54 Gy). Of 22 assessable patients, 11 (50%) had an objective radiologic response. The mean TX steady-state serum level was 2.44 micromol/L +/- 1.02 micromol/L. Only three patients completed the entire course of treatment without tumoral progression or significant toxicity. Common side effects included nausea and vomiting. Hepatotoxicity (five patients), neurotoxicity (two patients), venous thrombosis (one patient), bilateral ovarian cysts (two patients), and transient neutropenia (one patient) were also observed. Median survival was 10.3 months. Only four patients remain alive without tumoral progression. The 1-year survival rate (mean +/- SD) was 37.0% +/- 9.5%. CONCLUSION: This treatment combination produced no significant change in the overall poor prognosis of these patients. Most tumors responded initially to treatment but recurred as the study progressed. A minority of patients seemed to benefit from the extended use of TX. Generally, treatment was well tolerated, with good patient compliance, but we recommend continuous close monitoring for side effects. Based on our poor results, we recommend that alternative treatments be tested in patients with this type of tumor.

Adolescent↗
PubMed2000

Clinics in diagnostic imaging (52). Spinal cord schistosomiasis.

A 2-year-old Brazilian boy presented with bilateral leg weakness and constipation, followed by development of progressive paraparesis and bladder dysfunction. Neurological examination revealed flaccid paraparesis. Blood tests and CSF analysis showed eosinophilia. The MR examination revealed a spinal cord mass extending from T9 to L1 levels, with a heterogeneously-enhancing solid component and a cystic component. Stool tests for Schistosoma mansoni eggs were positive. The patient underwent surgery, the intramedullary mass was partially resected, and the diagnosis of spinal cord infection by Schistosoma mansoni was confirmed. After surgery, the patient was treated with praziquantel and oxamniquine. He was discharged with partial improvement of the lower extremity weakness and bowel/bladder function. The clinical and imaging features of spinal cord schistosomiasis are reviewed.

Child, Preschool↗
PubMed1998

Autosomal recessive deficiency of combined pituitary hormones (except ACTH) in a consanguineous Brazilian kindred.

Familial hypopituitarism represents a clinically and genetically heterogeneous disorder. In a subset of these families, defects in Pit-I, a transcription factor essential for proper pituitary development have been identified as underlying molecular cause. These patients present extreme short stature, GH, PRL and TSH deficiency but intact ACTH, LH and FSH secretion. The pituitary is usually hypoplastic. In this report we describe a consanguineous family (the parents are first cousins) with thirteen siblings. Of the ten living siblings, four (two males and two females) have panhypopituitarism with severe growth failure. They had evidence of growth hormone, prolactin and gonadotropin deficiencies and developed central hypothyroidism late in life. ACTH secretion was normal. Bone age was retarded and dual-photon bone densitometry indicated severe osteoporosis. Combined provocative tests for pituitary hormones indicated blunted responses for GH, LH, FSH and a modest rise in serum PRL and TSH. A clonidine-test failed to induce pituitary GH response. A corticotropin-releasing factor (CRF) provocative test was conducted after 6 months without the use of prednisone with a normal ACTH response after CRF in the affected sibling. Plasma IGF-I and IGF-BP3 were below normal levels. Serum E2 (females) and serum testosterone (males) levels were very low. MRI evaluation of the pituitary indicated pituitary aplasia in all subjects. The phenotype described in this kindred is different from families reported with Pit-1 mutations. However, it resembles previously published kindreds with similar clinical and biochemical findings. The relative preservation of ACTH suggests a genetic defect early in pituitary gland development.

Adolescent↗
PubMed1998

MR of parenchymal spinal cord signal change as a sign of active advancement in clinically progressive posttraumatic syringomyelia.

Extensive MR signal change in the craniad spinal cord parenchyma was found to be an ancillary sign of disease advancement in three patients with clinically progressive posttraumatic syringomyelia. This craniad margin of parenchymal spinal cord T2 hyperintensity resolved after cystoperitoneal shunt placement. There was a concomittant reduction or disappearance of the cyst in each instance, a halt in the progression of neurologic deficit, and some reversal of signs and symptoms.

Adult↗
PubMed1997

Autosomal recessive deficiency of combined pituitary hormones (except ACTH) in a consanguineous Brazilian kindred.

Familial hypopituitarism represents a clinically and genetically heterogeneous disorder. In a subset of these families, defects in Pit-I, a transcription factor essential for proper pituitary development have been identified as underlying molecular cause. These patients present extreme short stature, GH, PRL and TSH deficiency but intact ACTH, LH and FSH secretion. The pituitary is usually hypoplastic. In this report we describe a consanguineous family (the parents are first cousins) with thirteen siblings. Of the ten living siblings, four (two males and two females) have panhypopituitarism with severe growth failure. They had evidence of growth hormone, prolactin and gonadotropin deficiencies and developed central hypothyroidism late in life. ACTH secretion was normal. Bone age was retarded and dual-photon bone densitometry indicated severe osteoporosis. Combined provocative tests for pituitary hormones indicated blunted responses for GH, LH, FSH and a modest rise in serum PRL and TSH. A clonidine-test failed to induce pituitary GH response. A corticotropin-releasing factor (CRF) provocative test was conducted after 6 months without the use of prednisone with a normal ACTH response after CRF in the affected sibling. Plasma IGF-I and IGF-BP3 were below normal levels. Serum E2 (females) and serum testosterone (males) levels were very low. MRI evaluation of the pituitary indicated pituitary aplasia in all subjects. The phenotype described in this kindred is different from families reported with Pit-1 mutations. However, it resembles previously published kindreds with similar clinical and biochemical findings. The relative preservation of ACTH suggests a genetic defect early in pituitary gland development.

Adolescent↗
PubMed1997

MRI of cervical facet dislocation.

The MRI examinations of eight patients with cervical vertebral dislocation demonstrated by conventional radiography were reviewed. All patients had axial and sagittal T1- and T2-weighted imaging on a 1.5-T Unit. This revealed unilateral partial facet dislocation (in two patients), bilateral partial facet dislocation (in two), unilateral complete dislocation (in two) and bilateral complete facet dislocation (in two). In six patients there was cord contusion, three had focal disc protrusions and four unilateral absence of normal flow void in one of the cervical vertebral arteries. In all cases, the dislocated facets were shown well on the far-lateral sagittal images.

Adolescent↗
PubMed1997

MR imaging of intramedullary and intradural-extramedullary spinal cysticercosis.

OBJECTIVE: The purpose of our study was to retrospectively review the MR imaging findings in a group of patients with clinically proven cysticercosis involving the spinal cord, the spinal subarachnoid space, or both. MATERIALS AND METHODS: We retrospectively reviewed images of 16 patients with clinically diagnosed spinal cysticercosis to summarize the imaging characteristics. All patients underwent T1- and T2-weighted sagittal, axial, or both sagittal and axial MR imaging before i.v. administration of paramagnetic contrast media. Thirteen patients also underwent sagittal, axial, or both sagittal and axial T1-weighted MR imaging after i.v. gadolinium administration. In addition, all patients underwent cranial CT, MR imaging, or both to reveal possible evidence of cranial cysticercosis. RESULTS: MR imaging revealed isolated intradural-extramedullary involvement (n = 9), isolated intramedullary involvement (n = 3), combined intradural-extramedullary and intramedullary involvement (n = 3), and/or syringomyelia caused by infection and associated with chronic spinal arachnoiditis (n = 2). Evidence of intradural-extramedullary disease included cystic structures within the subarachnoid space or homogeneous sheetlike enhancement within the subarachnoid space over the surface of the spinal cord. Evidence of intramedullary disease included focal cystic lesions or syringomyelic cavitation of the spinal cord. All patients had evidence of simultaneous intracranial cysticercosis as shown on cranial CT, MR imaging, or both. CONCLUSION: In the absence of scolex visualization, cysticercotic involvement of the spinal cord or spinal subarachnoid space has a nonspecific appearance on MR imaging. On the basis of the findings in this group of patients, we believe that spinal cysticercosis is most often accompanied by intracranial disease.

Adult↗
PubMedDate not supplied

Pleomorphic xanthoastrocytoma of the cerebellum.

We report a clinicopathologic case of a pure cerebellar pleomorphic xanthoastrocytoma occurring in a 68-year-old male patient. The occurrence of pleomorphic xanthoastrocytoma outside the cerebral hemispheres is exceedingly rare. In the cerebellum only five cases have been reported so far, four of which are composite pleomorphic xanthoastrocytoma-gangliogliomas. This observation reinforces the argument that pleomorphic xanthoastrocytomas should be included in the differential diagnosis of cerebellar neoplasms.

Aged↗