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Biomedical subjects

L Mosca

Publications and source records attributed to L Mosca.

At least 73 records · Page 4Linked to original sources
PubMed1994

Some biochemical properties of melanins from opioid peptides.

Opioid peptides are converted by mushroom tyrosinase into melanin-like compounds retaining the peptide moiety (opio-melanins). Opio-melanins, owing to the presence of the linked aminoacids and in contrast with DOPA-melanin, are soluble compounds. The enkephalin-generated melanins are cleaved by carboxypeptidase A and pronase whereas aminopeptidase M cannot remove aminoacids from the pigment. Enkephalins, as well as other opioid peptides, (alpha-endorphin, kyotorphin, esorphins) if oxidized in presence of DOPA and tyrosinase are readily incorporated into DOPA-melanin. The resulting mixed-melanins (opio-melanin + DOPA-melanin) can be solubilized in hydrophilic solvents. Melanin from leu-enkephalin exhibits paramagnetism as evidenced by an EPR spectrum identical to that of DOPA-melanin, but unlike the latter pigment, it does not appear to oxidize NADH, probably for the presence of the peptide moiety that exerts a hampering effect on the oxidizing capacity.

Amino Acid Sequence↗
PubMed1994

Early detection of abnormal coronary flow reserve in asymptomatic men at high risk for coronary artery disease using positron emission tomography.

BACKGROUND: The objective of this study was to compare coronary flow reserve (CFR) as a measure of vascular integrity in asymptomatic middle-aged men with family history of coronary artery disease (CAD) and a high-risk lipid profile with men without risk factors for CAD using positron emission tomography (PET). Previous studies suggested that the assessment of CFR is a sensitive means to detect vascular abnormalities before angiographic appearance of CAD. N-13 ammonia PET scanning allows noninvasive evaluation of regional and global myocardial blood flow and thereby quantification of CFR. METHODS AND RESULTS: We used dynamic N-13 ammonia PET imaging in conjunction with intravenous adenosine to assess regional and global CFR in asymptomatic middle-aged men with high risk (group 1, n = 16) and men without any known risk factors (group 2, n = 11) for CAD. Group 1 patients were selected based on positive family history of CAD, one or more lipid abnormalities, and a normal stress test. No patient had history of diabetes or hypertension. A three-compartment tracer kinetic model developed and validated in our institution was used to calculate myocardial blood flow. Absolute myocardial blood flow (mL/100 g per minute) was calculated in five territories for each patient. CFR was defined as the ratio of blood flow during maximum pharmacological vasodilatation to blood flow at rest. Comparisons of CFR between the two groups of patients were performed. The mean age was similar between groups (group 1, 49.3 +/- 0.5 years; group 2, 48.1 +/- 8.7 years; P = NS). Group 1 had higher total cholesterol (mg/dL) (241 +/- 43 versus 173 +/- 34, P < .001), total cholesterol to high-density lipoprotein cholesterol ratio (6.4 +/- 1.6 versus 4.1 +/- 1.4, P < .001), and low-density lipoprotein cholesterol (mg/dL) (167 +/- 33 versus 107 +/- 32). No group 1 patient had evidence of ischemia by exercise ECG or exercise of pharmacological radionuclide perfusion studies. The mean global absolute myocardial blood flow at rest was not significantly different among groups (group 1, 76 +/- 18; group 2, 66 +/- 8; P = NS; (in mL/100 g per minute). However, blood flow after adenosine infusion was higher for group 2 (group 1, 217 +/- 56; group 2, 264 +/- 39; P < .001), which resulted in a larger CFR for group 2 (group 1, 2.93 +/- 0.86; group 2, 4.27 +/- 0.52; P < .001). Univariate linear regression analysis revealed significant negative correlation of CFR to total cholesterol (P < .05, r = -.41), low-density lipoprotein (P < .05, r = -.38), and total cholesterol to high-density lipoprotein cholesterol ratio (P < .05, r = -.47). CONCLUSIONS: Noninvasive quantification of absolute myocardial blood flow by N-13 ammonia PET allows the detection of abnormal vasodilatory response to intravenous adenosine in male patients with family history of CAD and high-risk lipid profiles. Early assessment of alterations of vascular reactivity to adenosine in relation to high-risk lipid profiles in asymptomatic men may allow early detection of preclinical atherosclerosis and may initiate modification and/or elimination of risk factors that may slow, retard, or even reverse the progression of CAD.

Adenosine↗
PubMed1992

Melanins production from enkephalins by tyrosinase.

Leu-enkephalin and Met-enkephalin are oxidized in vitro by mushroom and sepia tyrosinase giving rise to synthetic melanins whose production is dependent on incubation time and on enzyme concentration. The Enk-melanins formed are acid-insoluble brownish or reddish pigments showing a continuous absorbance in the visible region when dissolved in basic solution. The presence of the amino acid chain makes them fully soluble in pH 7.4 0.05 M phosphate buffer and methanol.

Amino Acids↗
PubMed1992

Hypophyseal pathology in AIDS.

One hundred and eleven pituitary glands of patients (93 males, 18 females; mean age 32 years, 5 months) who died of fully developed AIDS or ARC were examined under light microscopy with the aid of immunohistochemistry. On post mortem (p.m.) examination a wide series of multiorgan alterations was noticed. Microscopically various lesions in both adeno- and neurohypophysis were seen. These ranged from vessel damage to secondaries to systemic infections, neoplasms and functional derangements. Necrotic lumps due to recent infarction could appear in both parts of the gland, while old fibrous scars sustained a previously overcome necrosis. Different pathogens (mainly fungi) could be seen either within the gland or arising from its meningeal surroundings. Examples of tumour pathology were provided by microadenomas, gliosis/gliomas; the frequency of adenomas (11.7%) was similar to that typical of senility. The functional impairment was mainly connected with ACTH cell hyperplasia, which seems in keeping with corticoadrenal or ACTH-receptor damage.

AIDS-Related Complex↗
PubMed1990

Bronchial carcinoids with S-100 positive sustentacular cells. A comparative study with gastrointestinal carcinoids, pheochromocytomas and paragangliomas.

Fourty-six bronchial carcinoids, twelve tumourlets and twenty areas of neuroendocrine cell dysplasia (NED) were immunohistochemically evaluated for various neuroendocrine markers, S-100 protein (S-100), myelin basic protein, intermediate filaments, actin, Leu-7 and several neurohormonal polypeptides. Eighteen of the bronchial carcinoids (39.1%) showed a biphasic cell pattern, with abundant stellate-shaped S-100 positive cells (SC). SC were not reactive for chromogranin A, myelin basic protein, cytokeratins, neurofilaments, glial fibrillary acidic protein or actin, and were only occasionally weakly positive for vimentin. SC were not detected in the tumourlets nor in the NED observed. For comparison a group of other neuroendocrine tumours (11 gastrointestinal carcinoids, 4 pheochromocytomas and 4 paragangliomas) were immunostained for S-100, chromogranin A and actin. SC similar to the ones detected in the bronchial carcinoids could be detected in appendiceal carcinoids, paragangliomas and in two out of four pheochromocytomas. Our present data are in keeping with a Schwannian/sustentacular nature of SC rather than that of a histiocytic or myoepithelial nature. We suggest that SC-rich bronchial carcinoids are biphasic tumours, which could be designed "paraganglioid" bronchial carcinoids. The relationship between SC-rich bronchial carcinoids and tumourlets/NED is a matter of further investigation: SC-rich bronchial carcinoids may either differentiate in a biphasic pattern during tumoural growth or may not be histogenetically related to tumourlets.

Adrenal Gland Neoplasms↗
PubMed1989

Large cell neuroendocrine carcinoma of the lung.

Large cell neuroendocrine (LCNE) carcinomas of the lung are a newly recognized, highly aggressive and frequently misdiagnosed entity. We report a case of stage I LCNE lung carcinoma initially misdiagnosed as large cell undifferentiated carcinoma or poorly differentiated adenocarcinoma. The tumor was very extensively necrotic and its neuroendocrine differentiation was only demonstrable with immunohistochemical staining with PHE-5 monoclonal antibody and with antisera against synaptophysin and calcitonin. ACTH, somatostatin and neurofilaments were not demonstrable. The clinical course was ominous and the patient died within 17 months. The reason for this rapid fatal outcome could be ascribed either to the neuroendocrine phenotype of the tumor, or to the extensive necrosis, or both.

Adenocarcinoma↗
PubMed1989

Bronchial carcinoid with paranuclear fibrillary inclusions related to cytokeratins and vimentin.

A bronchial carcinoid with globular intracytoplasmic inclusions is reported. The inclusions stain brown with Grimelius silver impregnation and some show distinct immunoreactivity for chromogranin A. Tumour cells stain positively with antisera to neuron specific enolase, chromogranin A and not with antisera against ACTH, somatostatin or S-100 protein. The cells show distinct immunoreactivity for cytokeratins and vimentin, which is particularly intense in the intracytoplasmic inclusions. Desmin and glial fibrillary acidic protein are absent. Ultrastructural analysis reveals that the inclusions are composed of aggregates of filaments of 8-10 nm of diameter, intrapping a few neurosecretory granules. Immunohistochemical and ultrastructural data support the hypothesis that the inclusions are composed of intermediate filaments, whose metabolism and synthesis have somehow been deranged.

Bronchial Neoplasms↗
PubMed1989

Mediastinal malignant carcinoid with Cushing's syndrome: immunohistochemical and ultrastructural study.

A case of thymic atypical carcinoid with Cushing's syndrome and unfavorable clinical course is reported. Immunohistochemical analysis reveals distinct staining of tumor cells for ACTH, neuron-specific enolase, chromogranins (CG) and S-100 protein and with PHE-5 monoclonal antibody. At an ultrastructural level, the cells are undifferentiated with only a few neurosecretory granules. In the present case, immunohistochemical stainings for CG and with PHE-5 antibody seem reliable diagnostic tools, easily demonstrating the neuroendocrine nature of the neoplasm. NSE immunoreactivity can be an additional criterion. S-100-positive cells, which are present throughout the tumor, recall 'sustentacular cells', described in other neuroendocrine tumors.

Adrenocorticotropic Hormone↗
PubMed1988

Bronchial carcinoid with S-100 positive sustentacular cells.

A case of double bronchial typical carcinoid of the central type, with a nodal metastasis and paraneoplastic Cushing syndrome is reported. The case is remarkable because both the primary tumors and nodal metastasis were composed of a double cell population: one was arranged in nests, was argyrophilic, immunostained with PHE-5 monoclonal antibody, and contained neurosecretory granules; the other one was neither argyrophilic nor PHE-5-immunoreactive, but was strongly immunoreactive for S-100 protein, had a stellate morphology and was at the periphery of the nests of the other cells. The S-100 immunoreactive cells were regarded as a sort of "sustentacular" or "satellite" cells, which are themselves neoplastic. Bronchial carcinoids with S-100 positive cells, although strictly related with other bronchial carcinoids, may in fact represent a group of tumors with different histogenesis and/or differentiative pattern. More work should be done to elucidate whether there is any relevant clinical difference between bronchial carcinoids with or without S-100 reactive cells.

Adolescent↗
PubMed1988

Neuroendocrine lung structures and tumours: immunohistochemical study by specific markers.

Out of 360 lungs or lobes surgically removed, 13 non neoplastic specimens and 16 neuroendocrine (NE) tumours are investigated with immunohistochemical methods, in order to evaluate the presence of NE structures in normal and pathological human lungs. The markers used are neuron specific enolase (NSE), chromogranin (CG) and the 80 kd antigen (80 kdAg) of NE secretory granules detected by the new monoclonal Phe-5 antibody. In non-neoplastic lung specimens, clearcut immunoreactivity for all three markers appears in NE cells, neuroepithelial bodies (NEB), NE cell-hyperplasias and dysplasias. In the same specimens 4 tumourlets with analogous clearcut immunoreactivities were also observed. The NE tumours show distinct immunoreactivity for all three antisera in the 8 well differentiated cases. The 8 poorly differentiated tumours are variably immunoreactive for NSE and present low to nil staining with antisera to CG and 80 kdAg. The immunohistochemical data are interpreted according to current views about a possible relationship between NE tumours and parent normal NE lung structures.

Biomarkers↗
PubMed1987

A study of the interface between human bone and hydroxylapatite. A morphological and morphometric investigation.

The results are reported of clinical experiments conducted on four volunteers suffering from fractures of the tibia. Dense hydroxylapatite screws were used in association with conventional internal fixation. On removal of the plates and screws at periods varying from 4 to 12 months after implantation, the hydroxylapatite screws were removed together with a core of surrounding bone in order to study the bone hydroxylapatite relationship. Conventional and scanning electron microscopy was used, as well as dichromatic bone mineralometric tests. The results confirmed the excellent biocompatibility of hydroxylapatite with human bone. Arising out of this, the possible future clinical application of dense hydroxylapatite is discussed.

Adult↗
PubMed1987

Cytogenetics and acute non lymphocytic leukemia.

The authors report haematologic and cytogenetic data from 47 patients with ANLL, demonstrating the usefulness of cytogenetic studies for the classification as well as for the prognosis of this disorder. Chromosome studies also permitted the classification of marrow cellularity in: all diploid metaphases (NN), diploid and aneuploid metaphases (AN), and all aneuploid metaphases (AA). The remission rate for patients in whom only normal metaphases were detected (NN patients) was 83% while the remission rates were 67% and 33% respectively for patients in whom both normal and abnormal metaphases were seen (AN patients) and for those in whom only abnormal metaphases were noted (AA patients). In all FAB subgroups, complete remission was related to chromosomal abnormalities, except for M4 patients who evidenced a large number of complete remissions, although presenting more chromosomal abnormalities. The longer survival in this subgroup may be related to rearrangements of chromosome 16, which is associated with a better prognosis.

Acute Disease↗
PubMed1986

Neuroendocrine structures in normal and diseased human lung.

The increasing amount of histological, immunohistochemical and ultrastructural information on some endocrine secretions in human lung cancers suggest the need to revise the classification of neuroendocrine lesions on surgical material. The aim of the present investigation based on lung specimens removed surgically is to give further support to recent proposal for an updated classification of neuroendocrine lung carcinomas. Our study includes 58 squamous cell carcinomas, 58 adenocarcinomas, 6 large cell carcinomas, 27 neuroendocrine carcinomas, and 30 nontumourous cases. Using histological methods (HE, Alcian PAS, Grimelius silver impregnation), we illustrate the presence of neuroendocrine cells and neuroepithelial bodies with their pathological evolutions, ranging from hyperplasia, to dysplasia, and overt neoplasia. On the basis of our experience we propose the following classification of neuroendocrine carcinomas (NEC): typical carcinoids (NECNID), peripheral carcinoid or well-differentiated NEC (NECWED), NEC of intermediate or poorly differentiated type (NECINT) and NEC of small celled or microcytoma type (NECMIC).

Adenocarcinoma↗
PubMed1986

Ring chromosome 11. A case report and review of the literature.

A female infant with severe growth-weight retardation and with a ring chromosome 11, associated with trisomy X in 15% of metaphases, has been reported. A literature review of cases of r(11) shows that the clinical features of these patients, although showing different frequencies, are similar to those of the del(11q) syndrome. It has been suggested that the variability of the mental retardation in r(11) patients is attributable to the unstability of the ring and to the different break points in these two chromosomal rearrangements. The origin of the r(11) was also addressed by studying fragile sites of the parents at 11p15 and 11q25.

Abnormalities, Multiple↗
PubMed1985

Multiple sebaceous tumors and carcinomas of the colon. Torre syndrome.

The association of multiple tumors of the sebaceous glands with primary visceral carcinomas was described for the first time by Torre in 1967. Another 26 cases with similar features have been subsequently reported in the literature. In 12 of these patients isolated or multiple keratoacanthomas and in 8 intestinal polyps were also found. The authors add the report of a personal case. The patient is a 54-year-old man who, during a period of 8 years, has shown multiple sebaceous tumors, 1 keratoacanthoma, and 3 primary adenocarcinomas of the colon. The outline and nosologic position of this pathologic conditions are discussed.

Adenocarcinoma↗