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Biomedical subjects

N Nicolau

Publications and source records attributed to N Nicolau.

At least 19 recordsLinked to original sources
PubMed2000

Recovery of growth hormone secretion following cabergoline treatment of macroprolactinomas.

OBJECTIVE: Cabergoline therapy normalizes prolactin levels and reduces the size of macroprolactinomas. However there are no data indicating whether cabergoline can normalize growth hormone secretion in patients who were growth hormone deficient at the time of diagnosis of a macroprolactinoma. SUBJECTS AND METHODS: We studied nine patients with biochemical and radiological evidence of a macroprolactinoma who were also growth hormone deficient (peak growth hormone response to insulin-induced hypoglycaemia < 10 mU/l). Patients were assessed before and after cabergoline therapy to assess their growth hormone secretory status, IGF-I levels, cortisol response and change in tumour size. RESULTS: Treatment with cabergoline was associated with a significant reduction in prolactin concentration (74341 +/- 31939 mU/l vs. 265.9 +/- 86.3, P = 0.009). The mean change in peak growth hormone response to insulin-induced hypoglycaemia was significantly greater following cabergoline therapy compared with pretreatment levels (33.5 +/- 11.8 mU/l vs. 4. 34 +/- 1.21 mU/l, P = 0.022). However IGF-I levels were not different after treatment when compared with baseline although a nonsignificant trend towards improvement was noted (24.2 +/- 3.97 nmol/l vs. 18.4 +/- 4.94 nmol/l, P = 0.058). The mean peak cortisol concentration was 407.7 +/- 64.1 nmol/l before treatment with a nonsignificant rise to 477.4 +/- 84.8 nmol/l, P = 0.813 after treatment. These changes were associated with a significant reduction in mean maximal tumour diameter (21.2 +/- 2.9 mm vs. 29.1 +/- 2.8 mm, P = 0.009). There was no significant difference in either prolactin concentration or tumour size pre- or post-treatment between those who recovered growth hormone secretion and those that did not. Six of the nine (67%) patients recovered a normal growth hormone response (> 10 mU/l) after cabergoline therapy. Those that remained growth hormone deficient after treatment were all panhypopituitary at baseline while those that recovered showed only partial anterior hypopituitarism. CONCLUSION: These data indicate that growth hormone secretion may recover following successful reduction of prolactin levels after cabergoline therapy for a mean of 22 months (range 6-28 months) in most but not all subjects with a macroprolactinoma. It is therefore advisable that individuals with a macroprolactinoma in whom growth hormone replacement therapy is being considered undergo repeat assessment of growth hormone secretion following medical treatment.

Adolescent↗
PubMed1975

Ultrastructural investigations on the lysosomal system of lymph node lymphocytes in transplantation immunity.

Activation of the lysosomal system in T lymphocytes is demonstrated in connexion with immune stimulation, by electron microscopic study of the lymph nodes draining skin allografts. The development of primary lysosomes from enlarged Golgi apparatus, their fusion with autophagic and secretory vacuoles forming secondary lysosomes, of the cytolysome and crinophagosome type, were identified by the ultrahistochemical acid phosphatase reaction, suggesting the involvement of these organelles either in blastic transformation or in the effector function of lymphocytes, in connexion with the elaboration of active factors and cytotoxic events.

Animals↗
PubMedDate not supplied

Morphophysiopathological correlations in pulmonary hypertension of cardiac origin.

100 patients with congenital malformation and acquired cardiac diseases were studied on preoperatory pulmonary biopsies to estimate the pulmonary hypertension by correlating the data obtained by modern multidisciplinary investigation: histological, histoenzymological, ultrastructural, physiological and clinical techniques. The morphological pictures show a range of vascular lesions similar to those found in Heath and Edwards' classification and they are especially thickenings of the intima, hypertrophies of the media, narrowings of vascular lumen and later some plexiform lesions and hemosiderosis. Progressive fibrosis processes as well as immune pulmonary reactions were made evident. The electron microscopical examinations provided new data regarding the thickening of the capillary and alveolary basal lamina, the activity of pneumocytes and macrophages that were also certified from the histoenzymological point of view by increase of peroxidases and acid phosphatases activity. The investigation carried out proved the importance of the cardiac preoperatory catheterism in order to establish the grade of the pulmonary hypertension while the concordance index is more increased than in the cases that were investigated only by non-bleeding techniques.

Capillaries↗
PubMedDate not supplied

Histochemical and ultrastructural alterations of lysosomes and acid phosphatase reaction in human chronic hypoxic myocardium.

Histochemical and ultrastructural alterations of lysosomes and acid phosphatase reaction were assayed in myocardial human specimens from patients with some acquired and congenital cardiac affections and cardiac failure class II-IV (after NYHA classification). The optic and electron microscopic study of the acid phosphatase (the main lysosomal marker) activity reveals that the intensity and the distribution of the reaction were correlated with the degree of heart failure, being maximum at the IVth degree. The electron microscopic analysis of the lysosomal vacuolar apparatus emphasizes various changes also correlated with the intensity of hypoxia.

Acid Phosphatase↗
PubMedDate not supplied

Electronmicroscopic and histoenzymological researches regarding myocardial biology in some malformations.

A number of 65 heart malformations, taken from intraoperatory biopsies at different degrees of congestive heart failure were histological, histoenzymological and electronmicroscopical analyzed. It was followed the pathogenesis of the lesions determined by the hemodynamic and hypoxic intracardiac disorders. These hadn't specificity and were disseminated in different evaluative degrees, being predominant in certain myocardial areas. Initially, cardiomyocytes hypertrophical changes appear, and also changes of the edematous matrix. Then, the nuclear lesions, the apoptosis processes and the hypoxic alterations increased to cytolysis. In succession, after the matrix edema was organized, immune lesions and myocardial sclerosis processes appeared. Out of the various lesions, we mention: the sarcoplasmatic fuchsinophilia and alcianophilia, the glycogenic depletion, the decrease of SDH, LDH reactions, the increase of the cytolitic enzymes, especially of the kathepsine B. Out of the ultrastructural changes, we mention: the mitochondrial, sarcotubular lesions and, the lysosomial activations, the interstitial organelles, including the natriuretic granules, synthesized in the ventricular myocytes, details regarding the matrix changes with tendency to fibrosclerosis.

Adolescent↗
PubMedDate not supplied

Morphological and immunohistochemical features of tumor infiltrating lymphocytes (TIL) in carcinomas. Note I.

Some malignant tumours like testicular seminomas and ovarian dysgerminomas or medullar carcinoma of the breast, present an unusually lympho-histiocytic (TIL) rich stroma. Many reports have concluded that the prognosis for these patients is correlated with the intensity of TIL. Recently, some analyses consider that tumour-host interactions have a significant prognostic role in many other neoplasms. The presence of TIL may be a sign of less aggressive behaviour of some epithelial neoplasm like gastro-intestinal, pulmonary, mammary, urinary or cutaneous carcinomas (Wilson et al.). The aim of this study is a morphological and immunohistochemical (IHC) characterisation of the lympho-histiocytic populations of TIL in some gastro-intestinal and mammary carcinomas. The two localisation were chosen for their different contact with the exogene antigens and their possible different type of host's immune response.

Adenocarcinoma↗
PubMedDate not supplied

Histochemical investigation of myocardial proteases in heart anoxia, under protection with cardioplegic solution and protease inhibitors.

We studied the histochemical behaviour of neutral non-lysosomal and acid lysosomal proteases of the myocardium in heart anoxia by aorta-clamping, using an experimental model alike to the open heart surgery conditions. After one hour of blood deprivation we found destabilization, conglomeration, diffusion and extracellular release of the histochemical reactions for neutral BANA-reactive proteases, cathepsin B, acid and neutral gelatinases in monkey, rat and mice myocardium, in connection with lytic ultrastructural lesions. Intracardiac perfusion with cardioplegic solution exerted a partial protective effect which is improved by adding Trasylol, a protease inhibitor. Administration of Trasylol by intravenous injections preceding aorta clamping, or/and by intracardiac perfusion after aorta clamping, normalized the histochemical reactions of proteases together with the ultrastructural organization of the myocardial fibres. Acting especially by the inhibition of membrane serine proteinases, Trasylol may intercept membrane permeabilization events, impairing the proteolytic cascades triggered by anoxia.

Animals↗
PubMedDate not supplied

Histochemical reactions of myocardial proteases during open heart surgery.

Histochemical analysis of some lysosomal and sarcoplasmic proteolytic enzymes was assayed in human myocardial biopsies taken from 26 cardiopathic patients subjected to open heart operations, under extracorporeal circulation and protection with cardioplegic solution and hypothermia. The investigated myocardial proteases were: cathepsin B, cysteine aminopeptidase, acid gelatinases, trypsin-like endopeptidase, chymotrypsin-like endopeptidase and neutral gelatinases. The effects of surgical interventions appreciated by comparing the myocardium fragments harvested before, and at various intervals after aorta clamping (6-90 minutes) revealed disorders in the activity and compartmentalization of all the investigated proteases, whose histochemical reactions increased between 10 and 20 minutes after aorta clamping and manifested a lowering tendency with sarcoplasmic diffusion and extracellular release at longer periods than 20 minutes. The early activation of the neutral proteases and their sarcolemmal expression even before 10 minutes after aorta clamping, suggested the involvement of the nonlysosomal proteases in the first proteolytic events implied in the molecular membrane damage of the myocardial fibre. Sequential proteolytic cascades of abnormal neutral and acid proteases were emphasized as possible mediators and effectors of molecular and subcellular damages suffered by the myocardial fibers during the open heart operations, even under cardioplegic and hypothermic protection.

Cardiac Surgical Procedures↗