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Biomedical subjects

J F Nunes

Publications and source records attributed to J F Nunes.

At least 19 recordsLinked to original sources
PubMed1994

Calcitonin-producing insulinoma: clinical, immunocytochemical and cytogenetical study.

The case of a patient with a large goitre associated with hypercalcitoninaemia and fasting hypoglycaemia is reported. Pentagastrin (PG) test was negative. Repeated measurements of fasting glycaemia, insulin and C peptide established the diagnosis of insulinoma. After localization by endoscopic ultrasonography, a distal pancreatectomy was performed and a small insulinoma was recovered. Glycaemia and calcitonin (CT) became normal. The tumour cells displayed a strong immunoreactivity for insulin and CT. Cytogenetical evaluation of the tumour revealed a translocation t(1;9) (p13;p22).

Aged↗
PubMed1994

[Central neurocytomas].

Central neurocytomas are a well-characterized group of neuronal tumors usually arising in the supratentorial ventricular cavities. We describe the anatomical and clinical study of seven of these neoplasms. Patients were in the first four decades of life, and tumors were usually located in one of the lateral ventricles. Surgical resection was subtotal in 6 cases. Light microscopic examination revealed predominantly benign lesions with morphological features similar to the so-called ependymoma of the foramen of Monro, of the oligodendrogliomas, and of the neuroblastomas. Immunohistochemistry and electron microscopy confirmed the diagnosis in each case, showing expression of neuron specific enolase and synaptophysin and containing microtubuli, neurosecretory granules, and presynaptic vesicles. In agreement with the literature, the authors stress the benign behaviour of most of these tumors and the need for systematic immunohistochemical and ultrastructural study. The actual roles of the extent of resection and of postoperative radiotherapy are still a matter of discussion.

Adolescent↗
PubMed1993

Multihormonal response to CRH in a patient with Cushing syndrome and a pituitary adenoma producing ACTH and GH.

Preoperative bilateral and simultaneous catheterization of the inferior petrosal sinuses was performed in a patient with Cushing's syndrome. This procedure revealed parallel intersinus gradients for ACTH, PRL, GH and a response of all these hormones to CRH. The patient had transphenoidal surgery and a soft white-yellowish mass occupying the whole sella conditioned a total hypophysectomy. Morphologic studies and immunostaining techniques revealed a rare mixed pituitary adenoma of ACTH and GH containing cells and failed to demonstrate PRL immunoreactivity in the tumor cells. These results are of clinical and speculative interest. Whether GH and PRL secretion in response to CRH stems from the tumor or reflect hormone release by non-tumor cells via a paracrine effect remains to be defined.

Adenoma↗
PubMed1992

A kindred with multiple endocrine neoplasia type 2A associated with pruritic skin lesions.

BACKGROUND: A kindred affected by multiple endocrine neoplasia type 2A (MEN 2A), associated with symmetric, bilateral, scapular pruritic skin lesions (PSL), is reported. METHODS: There were 21 members, including the propositus, in four generations. Screening of 10 family members showed a palpable thyroid tumor in 1 and positive results for a pentagastrin test in 7 others. Two of these patients had surgically confirmed pheochromocytoma. Two others had a biochemical diagnosis of pheochromocytoma but did not have surgery. RESULTS: Medullary thyroid carcinoma was confirmed in five patients and nodular C-cell hyperplasia in another. In five affected adults, PSL were observed in the interscapular region, crossing the midline in some. These lesions were characterized by hyperkeratosis and hyperpigmentation. In all the patients, the pruritus had been present long before the clinical or biochemical diagnosis. Skin biopsies were performed in two of these patients. No amyloid deposits were found (Congo red stain and electron microscopic examination were used). Two children (14 and 6 years old) in the fourth generation complained of scapular pruritus, although skin lesions were not apparent. CONCLUSIONS: Localized PSL must be sought when screening for MEN 2A.

Adolescent↗
PubMed1987

Plasma cell granuloma of the tongue. Report of a case.

A case of plasma cell granuloma of the tongue in an otherwise symptomless 48-year-old caucasian female is reported. The polyclonal nature of the plasmocytes was revealed by immunostaining of kappa and lambda light chains. Electron microscopic observations showed typical mature plasmocytes. A parasitic etiology of this type of lesion is suggested.

Female↗
PubMed1982

[Role of seminal plasma in the in vitro survival of goat sperm].

The in vitro survival of ejaculated and epididymal goat sperm was measured in a milk diluent while being incubated at + 37 degrees C and after having been exposed to seminal plasma or to its components. Non-breeding season seminal plasma had a negative effect on sperm survival whether the cells were cooled to + 20 degrees C, chilled to + 4 degrees C or deep-frozen (- 196 degrees C) before being incubated at + 37 degrees C. Bulbo-urethral gland secretions also had a deleterious effect on the survival of washed ejaculated and epididymal sperm cooled to + 20 degrees C. The deleterious effect of the bulbo-urethral secretions on sperm survival and motility was significantly inhibited by the vesicular secretions. Non-breeding season seminal plasma contained bulbo-urethral but little or no vesicular secretions. The non-inhibition of their negative effect(s) may explain that of non-breeding season seminal plasma. Breeding season and non-breeding season washed ejaculated sperm had a better survival and a better motility than those incubated with breeding season seminal plasma. The mild washing procedure used may be responsible for the incomplete removal of seminal plasma from the sperm environment, namely that of the negative factors of the bulbo-urethral secretions. Breeding season seminal plasma would thus simply inhibit the effect of these negative factors or the factors themselves. This hypothesis is supported by the fact that breeding season seminal plasma had no effect on the survival of epididymal sperm.

Animals↗
PubMed1981

Photographic defocusing: a means to render recognizable line traced models of negatively stained biological specimens.

A simple method of obtaining analogue images from traced models of biological specimens is presented. It consists of the photographic defocusing of traced models and it is illustrated with negatively stained cylindrical forms of the ASFV; the black lines of the trace in the model correspond to the negative stain surrounding the viral morphological subunits as seen in the electron micrograph. The photographic defocusing is the means by which the traced model is filtered and is used to introduce grey levels on an otherwise black and white image. The right amount of defocusing is attained when the width of the trace of the model equals the width of the rim of the negative stain appearing between the morphological subunits in the electron micrograph.

African Swine Fever Virus↗
PubMed1980

Neuronal ceroid-lipofuscinosis: ultrastructural study of lymphocytic dense bodies.

We studied the ultrastructural alterations of the dense bodies of peripheral blood lymphocytes in one case of neuronal ceroid-lipofuscinosis. These cytoplasmic vesicles were characterized by vacuolar transformation and "fingerprint" content. When we tilted the specimens, the "fingerprint" arrangement was shown to be the same as the arrangement of the crystalloid inclusions found in the same cells. Both vacuoles and periodic cytoplasmic inclusions could be due to a disorder of secondary lysosomes--the lymphocytic dense bodies.

Ceroid↗
PubMed1979

Micro-buffy coats of whole blood: a method for the electron microscopic study of mononuclear cells.

A method for the electron microscopic study of human peripheral lymphocytes by which very small buffy coats are obtained through centrifugation of heparinized whole blood in glass or plastic microhematocrit tubes is presented. This method is time saving and efficient, yielding well preserved material and a comparatively large number of mononuclear cells (mainly lymphocytes) in each thin section.

Cell Separation↗
PubMed1978

Autophagy in mouse hepatocytes induced by lysine acetylsalicylate.

I.v. administration of lysine acetylsalicylate inces autophagy in mouse liver cells. Single and multiple membrane-bounded vacuoles were found. The latter seems to be an unusual morphological form of the sequestration process. These findings could express a transitory sublethal liver cell injury induced by the drug.

Animals↗
PubMed1975

The effects of chronic cannabis treatment upon brain 5-hydroxytryptamine, plasma corticosterone and aggressive behavior in female rats with different hormonal status.

Ovariectomized rats, chronically treated with cannabis extract or control solution, were given different hormonal treatments. Results indicated that both cannabis-treated and estrogen-treated animals were more aggressive than controls. Furthermore, aggressiveness was virtually abolished when cannabis-treated females were made sexually receptive by estrogen and progesterone treatments. After 25 days of cannabis or control solution treatment, all subjects were sacrificed. The levels and turnover rate of brain 5-HT and peripheral plasma corticosterone were then assayed. Data indicated both a significant inverse relationship between plasma corticosterone and whole brain levels of 5-HT(r = -0.742 to -0.985) for all groups and a significant positive relationship between aggressive behavior and plasma corticosterone (r = +0.675 to +0.946) in all groups that were fighting prior to decapitation. Results are tentatively explained, suggesting that the variability of the female response to stress during the different phases of the estrus cycle, permitted them to perform differently after chronic cannabis treatment. 5-HT is apparently involved, either directly in its effects on aggressive behavior or indirectly through the pituitary-adrenocortical axis activation.

Aggression↗