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Biomedical subjects

N P Ferreira

Publications and source records attributed to N P Ferreira.

At least 19 recordsLinked to original sources
PubMed2004

Measurement of Ki-67 antigen in 159 pituitary adenomas using the MIB-1 monoclonal antibody.

Pituitary adenomas sometimes show rapid growth and recurrence, and about one third invade the structures surrounding the sella turcica. In an attempt to determine aggressive behavior at an early stage, we used the MIB-1 antibody to identify the Ki-67 antigen. The present study was designed to evaluate pituitary adenomatous tissue in terms of secretion and proliferation and to correlate the Ki-67 index with hormone phenotype and invasive behavior. Material from 159 patients submitted to one or more resections of pituitary adenomas was evaluated. Forty-two non-secretory adenomas and 43 adenomas immunoreactive for growth hormone, 19 for prolactin, 18 for growth hormone and prolactin, 16 for adrenocorticotropic hormone (ACTH), and 21 cases of plurihormonal/gonadotropin adenomas were detected by immunohistochemistry. The MIB-1 antibody was positive in 139 samples and the Ki-67 index ranged from 0.16 to 15.48% (mean = 1.22 +/- 2.09%), with no significant difference between genders, age groups, or secretory and non-secretory status. The Ki-67 index was higher in ACTH-secreting adenomas. Invasive pituitary adenomas had a significantly higher Ki-67 index (2.01 +/- 3.15%) than macroadenomas with or without supra-sellar extension (1.12 +/- 1.87%; P = 0.02). The index was not significantly different in the subgroup of adenomas with invasion of the cavernous sinus compared to groups with other types of invasion. We conclude that tumoral proliferative activity evaluated by the detection of the Ki-67 antigen is significantly higher in invasive than noninvasive adenomas, information which can be useful in therapeutic postoperative management since index cut-off values associated with aggressive behavior can be established.

Adenoma↗
PubMed2004

Dynamics of serum cortisol levels after transsphenoidal surgery in a cohort of patients with Cushing's disease.

Transsphenoidal pituitary surgery is the treatment of choice for Cushing's disease (CD). Despite the widespread acceptance of this procedure, there is no agreement regarding the definition of successful treatment. We prospectively studied postoperative serum cortisol dynamics in 41 patients with CD (including a total of 45 surgeries). The mean postoperative follow-up period was 4.8 yr. Remission was defined as clinical and laboratory signs of adrenal insufficiency, glucocorticoid dependence, and serum cortisol suppression on overnight oral 1-mg dexamethasone suppression test. Serum cortisol was measured preoperatively and postoperatively at 6, 12, and 24 h (28 surgeries) and at 10-12 d (45 surgeries). No statistical difference was detected in mean preoperative and 6-h postoperative cortisol levels between surgically induced remission patients [22.1 +/- 7.73 microg/dl (610 +/- 213.3 nmol/liter) and 25.2 +/- 19 microg/dl (695.2 +/- 524.4 nmol/liter)] and surgical failure patients [23.6 +/- 6.95 micro g/dl (651.4 +/- 161.8 nmol/liter) and 37.5 +/- 18.1 microg/dl (1035 +/- 499.6 nmol/liter); P = 0.50 and P = 0.17]. At 12 and 24 h after surgery, the difference was significant (P = 0.009 and P < 0.0001). Mean cortisol levels were 12.44 +/- 13.3 microg/dl (343.3 +/- 367.1 nmol/liter) and 4.72 +/- 6.72 microg/dl (130.3 +/- 185.5 nmol/liter) in the remission group and 26.3 +/- 7.06 microg/dl (725.9 +/- 194.8 nmol/liter) and 23.5 +/- 6.86 microg/dl (648.6 +/- 189.3 nmol/liter) in the failure group (P = 0.009; P < 0.0001). At 10-12 d after the procedure, the difference was also significant (P < 0.0001): cortisol levels were 2.52 +/- 3.32 microg/dl (69.5 +/- 91.6 nmol/liter) in the remission group and 24.9 +/- 13.3 microg/dl (687.2 +/- 367.1 nmol/liter) in the failure group. In conclusion, in the immediate postoperative period of transsphenoidal surgery, remission of CD is not necessarily defined by undetectable serum cortisol. During the first 10-12 d after surgery, cortisol nadir correctly classified the remission [cortisol, 7.0 microg/dl (193.2 nmol/liter) or less] and the failure groups [cortisol, 8.0 microg/dl (220.8 nmol/liter) or more]. Glucocorticoid should be administered only after laboratory and/or clinical evidence of adrenal insufficiency.

Adenoma↗
PubMed2002

Expression of p53 protein in pituitary adenomas.

Inactivating mutations of TP53, a tumor suppressor gene, are associated with abnormal cell proliferation. Although p53 expression is common in many human malignancies, p53 protein has seldom been evaluated in pituitary tumors. When detected, the percentage of p53-positive cells is low, and, in general, it is exclusive for invasive lesions. The aim of the present study was to use immunohistochemistry to determine the presence of p53 protein in pituitary adenomas from tumor samples of 163 surgeries performed in 148 patients (40% male, 60% female). In 35% of the cases the adenoma was nonfunctional, while in the others it was associated with PRL, GH and/or ACTH endocrine hypersecretion syndrome. Macroadenomas were observed in 83.2% of the cases with available neuroimage evaluation, of which 28% invaded the cavernous, sphenoid and/or ethmoidal sinus, bone, third ventricle or subfrontal lobe. p53 protein was detected in 2/148 patients (1.3%). Immunohistochemistry was positive for PRL and GH in these cases. Due to the high percentage of invasive pituitary adenomas found in our study, the low frequency of p53 detection suggests that it is inadequate as a routine marker for aggressiveness and as a predictive factor of tumor behavior.

Adenoma↗
PubMed2000

Risk factors of neurological lesions in low cervical spine fractures and dislocations.

Eighty-nine patients with lower cervical spine fractures or dislocations were evaluated for risk factors of neurological lesion. The age, sex, level and pattern of fracture and sagittal diameter of the spinal canal were analysed. There were no significant differences on the age, gender, level and Torg's ratio between intact patients and those with nerve root injury, incomplete or complete spinal cord injuries. Bilateral facet dislocations and burst fractures are a significant risk factor of spinal cord injury.

Adult↗
PubMed1994

Lipoma of the cerebellopontine angle. Case reports and literature review.

Two patients with cerebellopontine angle (CPA) lipoma were studied. They were submitted to surgical treatment. Available literature was reviewed and 29 cases with same lesion were identified which had been treated by surgery. Clinical manifestations, possibility of diagnostic methods, surgical indications and treatment strategies are discussed. Attention is called to the peculiarities of CPA lipomas and the doubtful validity of attempting complete excision in all cases.

Adult↗
PubMed1992

Optic nerve apoplexy caused by a cavernous angioma: case report.

A case of a cavernous angioma of the optic nerve is presented. The abrupt onset of monocular visual symptoms was accompanied by an intense bitemporal headache, indicating apoplexy of the optic nerve. The surgical and histological findings demonstrated a cystic cavernous angioma. The lesion was removed completely without any noticeable bleeding. The preoperative visual deficit persisted.

Cerebrovascular Disorders↗
PubMed1992

[Spontaneous intraparenchymatous hematomas. Experience with 134 cases].

One hundred thirty four cases of spontaneous intraparenchymatous hematomas have been studied. They were separated into six groups according to criteria related to topography, level of consciousness, and hematoma volume. Treatment protocols--conservative, conservative with I.C.P. monitoring, and surgical--were different in each group. Results have shown an increased mortality (p < 0.05) among patients whose level of consciousness were more severely compromised, in those older than 50 years old, and in those harbouring quadrilateral, intraventricular or brainstem hematomas. Overall mortality was 26.1%.

Adolescent↗
PubMed1992

[Macroprolactinoma at 6 years of age: diagnostic difficulties].

Prolactinoma is rare in childhood and adolescence. The earliest known diagnosis was reported in a patient at 8 years of age. We report the case of a sellar tumor found in a 6 years old girl. After a long symptomatic period she was brought for treatment. At this time she had partial papillar atrophy, hyperprolactinemia, and diminished reserve of growth hormone and cortisol. Due to rapid visual deterioration, she was submitted to a frontotemporal craniotomy for suspected craniopharyngioma. The tumor tissue immunohistochemistry was positive for prolactin. It is concluded that prolactinoma must be considered in differential diagnosis of sellar tumors in childhood since it benefits from a less aggressive therapy.

Child↗
PubMed1991

[Massive intratumor hemorrhage in tuberous sclerosis. Autopsy study of a case].

A case of a 13-year-old boy with tuberous sclerosis manifested with the complete syndrome that died with a massive intratumoral hemorrhage is presented. The post mortem examination of the brain disclosed a massive left parenchymatous brain hemorrhage with intraventricular component. In the hemorrhage, near the lateral ventricle wall, a subependymal giant cell astrocytoma was found. This is the second case in the literature of tuberous sclerosis which cause of death was an intratumoral massive hemorrhage.

Adolescent↗
PubMed1989

Anatomoradiological correlation of the intersection of the carotid siphon with the dura mater.

In order to obtain frames of reference to determine the place of intersection of the carotid siphon with the dura mater in conventional arteriograms, a debated topic lacking general agreement in the literature, 34 cadaveric sphenoids were prepared with the injection of radiopaque medium in both internal carotid arteries. After having marked the dura mater with steel wire, the pieces were radiographed in lateral view. The points of intersection of the clinoclinoid line and the sphenoidal line with the internal carotid artery as well as the emergence of the ophthalmic artery and its posterior projection were marked on the radiographs obtained. The distances between the various points were measured and submitted to statistical treatment. The results showed multiple regressions with a strong correlation coefficient in two equations. A table was built in which, knowing the distances between the points of the clinoclinoid and the sphenoidal plane lines and those of the ophthalmic artery and its projection, the position of the dura mater which covers the cavernous sinus may be estimated in arteriograms.

Carotid Arteries↗
PubMed1989

[Pituitary adenomas: immunohistochemical study of 167 cases].

One hundred and sixty seven cases of pituitary adenoma were analysed using the immunocytochemical method of the Avidin-Biotin Complex (ABC), described by Hsu et al. (1981). Six pituitary anti-hormones were utilized: anti-prolactin (aPRL) at a 1:1,500 dilution; anti-growth hormone (aHGH) at a 1:4,000 dilution: anti-adrenocorticotrophic hormone (aACTH) at a 1:3,000 dilution; anti-thyrothrophic hormone (aTSH) at a 1:3,000 dilution; anti-luteinizing hormone (aLH) at a 1:1,000 dilution; and a anti-follicle-stimulating hormone (aFSH) at a 1:300 dilution. Incubation period was 14 to 16 hours at 4 degrees C. The survey of clinical, laboratory and radiological data of cases of pituitary adenomas was performed after reading the stained slides using the immunocytochemical method. Of the 167 cases of pituitary adenomas, 136 (81.4%) disclosed a positive immunoreaction to one or more anti-hormones, and the positivity index of neoplastic cells varied from 1 to 90%. The immunoreaction was positive exclusively to one anti-hormone in 80 cases (58.8%) and to two or more anti-hormones in 56 cases, and the association most frequently found was between both aPRL and aHGH. The positivity to the immunoreaction was distributed as follows: -100 cases were positive for aPRL, exclusively in 4 cases; -65 cases were positive for aHGH, exclusively in 22 cases; -31 cases were positive for aACTH, exclusively in 8 cases; -5 cases were positive for aTSH, exclusively in one case; -one patient presented an adenoma positive to aLH and another patient to aFSH.

Adenoma↗
PubMed1985

Characterization of phages derived from strains of Rhodococcus australis and R. equii.

Rhodococcus australis strain CSIR-A201 and R. equii strain CSIR-A655 spontaneously liberated phages A and B, respectively. The phages have different host ranges, but both infect R. rubropertinctus ATCC 14352. phage infection of strains resulted in stable lysogeny. The phages have similar morphologies and belong to the family Styloviridae. The DNA restriction enzyme patterns of the phages differ and do not correspond to those of actinophage phi EC. These temperate phages did not transduce prototrophic or antibiotic resistance markers to appropriate hosts.

Actinomycetales↗
PubMed1981

[Spinal tumors: apropos of 100 cases].

One hundred cases of spinal tumors are studied concerning to the histological type, age, topography and evolution of the clinical manifestation. In the given material was identified a predominance of the tumors of the neural tissue and associated structures: neurinomas (16%), meningiomas (15%), ependymomas (4%) and astrocytomas (2%); following metastatic tumors (32%), tumors of mesenchymal tissue (16%): fibroma (2%), lipomas (2%), haemangioblastoma (4%), angiosarcoma (2%), angioma (1%), angioblastoma (1%), chordomas (2%), osteoblastoma (1%) and adamantinoid tumor (1%); tumors of lymphatic and haematopoietic tissue: plasmacytoma (6%), histiocytic lymphoma (3%), lymphocytic lymphoma (2%), Hodgkin (1%) and unclassified lymphomas (1%); teratomas: differentiated teratoma (1%).

Age Factors↗