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J Pereira

Publications and source records attributed to J Pereira.

172 records · Page 10Linked to original sources

Testing the precision of stereotactic planning systems.

The implementation of effective methods of testing the precision of computations, is essential for the development of medical systems, such as the stereotactic planning software for neurosurgery. During the development of our planning system we designed, in addition to the traditional phantom test, some tests based on digitally constructed images. These tests give quantitative and qualitative measurement of the precision and stability of the calculations, and are easy to implement and isolate the program error from the mechanical and image acquisition errors. The verification of our software shows good precision in coordinates calculation and a significant impact of pixel size and interscan spacing on the precision.

Brain↗

Relationship between digestive and killing abilities of neutrophils against Paracoccidioides brasiliensis.

Peripheral blood neutrophils (PMN) from patients with paracoccidioidomycosis killed and digested Paracoccidioides brasiliensis much less than did PMN from normal individuals or from patients with other diseases. However, deficiency in killing ability was less specific than digestive deficiency and correlated poorly with it. We conclude that the capacities of PMN to digest and kill P. brasiliensis are not intimately related phenomena, and that in paracoccidioidomycosis the key deficiency of neutrophil function is that of digestion of P. brasiliensis.

Adult↗

Specific digestive deficiency of phagocytes in paracoccidioidomycosis. Its absence in peripheral blood neutrophils of members of the nuclear family of patients. An initial report.

Paracoccidioidomycosis (PARA) affects only a minority of individuals, who have presumably been exposed to the causative fungus (Paracoccidioides brasiliensis). Neutrophils (PMNs) from patients with PARA show a significant and specific digestive deficiency phagocytosed P. brasiliensis in vitro. It is not known whether the defect is acquired after contact with the fungus, or precedes it. We studied the spouses and offspring of three patients with PARA. Individuals studied stayed in the same house as their husband or father. None of the relatives had evidence of PARA, and their PMNs showed no defect in their ability to digest or kill the fungus. Relatives showed no indication of sensitization against P. brasiliensis. These results are compatible with the view that effective contact with P. brasiliensis may occur only under restricted conditions and that the defect in digestive ability is an infrequent and specific occurrence.

Adolescent↗

Mediastinal and pulmonary entomophthoromycosis with superior vena cava syndrome: case report.

The first case of mediastinal and pulmonary entomophthoromycosis with superior vena cava syndrome is reported. The patient presented with a history of edema of the face, neck and upper limbs as well as collateral circulation in the anterior wall of the chest. Histological examination of tissue from mediatinum revealed a granulomatous reaction with microabscesses surrounded by eosinophilic amorphous material and with broad hyphae in the center. Culture was not performed because a preliminary diagnosis of non-Hodgkin's malignant lymphoma was made. Surgical correction of the obstructed area was performed and the patient was successfully treated with potassium iodide. The authors propose that mediastinal entomophthoromycosis must be considered in the differential diagnosis of diseases causing superior vena cava syndrome in tropical and sub-tropical regions. This case enlarges the spectrum of clinical manifestations of the zigomycosis caused by Entomophthoraceae.

Adult↗

[Hematuria].

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Adolescent↗

[Craniopharyngiomas. Clinicopathological aspects in different age groups].

Craniopharyngiomas are rare brain tumors of the hypothalamo-pituitary region, developing from embryonic remnants of Rathke's pouch and sac. Their overall incidence is 0.13 per 100,000 person years. Most frequently, they are suprasellar, start growing in childhood and originate neurological and hormonal symptoms. We retrospectively studied patients treated in our institution for craniopharyngioma in the last 10 years, in order to evaluate their clinical, imaging and pathological characteristics. Of the 32 patients analysed, 18 were females and 14 males with ages ranging between 6 and 81 years (early onset group--EOG aged 5-14 years: 7 patients; middle age onset group--MAOG aged 15-49 years: 15 patients; late age onset group--LOG aged > or = 50 years: 10 patients). Visual impairment was the most frequent presenting clinical feature in EOG (71.4%) and MAOG (86.6%), while in the LOG personality and cognitive changes including memory loss predominated (60%). Headaches were very frequent in all groups (EOG 42.8%, MAOG 60%, LOG 40%). Meningitis and seizures were presenting features, each in one patient. Regarding endocrine symptoms and signs, growth failure was present in 57.2% of the EOG. Amenorrhea was present in 5 of 10 female patients of the MAOG. Preoperatively, TSH was deficient in 25%, ACTH in 15.6% and gonadotropin in 25% of the patients. There were no cases of diabetes insipidus. Preoperative CT and MR revealed a calcified mass in 12 (37.5%), a partially cystic mass in 20 (62.5%) and a lesion involving or extending into the third ventricle in 7 (21.9%) patients. Twenty seven (84.4%) patients were treated primarily by surgery. In 4 (12.5%) cases the tumour was considered inoperable and 1 (3.1%) patient refused surgery; all were in the LOG. Surgical approach was transsphenoidal in 2/27 (7.4%) (all of them in the LAOG) and by craniotomy in the others. The tumour removable was considered complete in 10 (37%--EOG 2/7, MAOG 6/15, LOG 2/5) and subtotal in 17 (62.9%) patients. Eight (29.6%) patients were reoperated for recurrent tumour. Postoperative radiotherapy was administered in 12 cases with residual tumor, and 3 inoperable tumors were treated primarily by conventional external radiotherapy. Pathological study revealed the adamantinomatous type in 25 (92.6%) and the papillary type in 2 (7.4%--all men in the MAOG) tumors. The average follow-up was longer in the EOG (82.6 +/- 40.7 months) than in MAOG (57.2 +/- 48.5 months) and in LOG (48 +/- 92 months). Four (12.5%) patients died, 1 during the follow-up period due to a radiation-induced astrocytoma and 3 in the postoperative period because of cerebral hemorrhage and hydrocephalus (1 in the EOG and 2 in the LOG). In summary, we found the clinical presentation to be different in the 3 age groups, with a large number of patients in the MAOG. In this group were the only examples of the papillary form. Better prognosis was associated with a total resection at initial surgery.

Adolescent↗

[The use of computed tomography in assessing parotid masses].

Thirty-one patients with suspected parotid masses have been studied by computed tomography (CT) without and with contrast to demonstrate the existence of this and to value possible relation between degrees of malignancy and the morphological characteristics of the masses.

Adolescent↗

[Phagocytic function of polymorphonuclear leukocytes and lymphocyte subpopulations in patients with amebiasis].

We initiated a pilot study to evaluate the functions of polymorphonuclear leukocytes and also to analyze the behavior of lymphocyte subpopulations in patients with different clinical forms of amoebiasis. We found significant differences in many aspects as NBT reduction, Candida digestion, CD4/CD8 relation, Ia expression. We suggest a wider investigation of the mechanism of cell mediated immunity in patients with amoebiasis.

Adolescent↗