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Biomedical subjects

G De Luca

Publications and source records attributed to G De Luca.

At least 235 records · Page 13Linked to original sources
PubMedDate not supplied

Cysteic and cysteine sulphinic acid decarboxylase activity in rat tissues during postnatal growth.

1) Cysteic and cysteine sulphinate decarboxylase activities have been determined in rat retina, brain, liver, kidney, lung and spleen during postnatal growth. 2) The two enzymic activities increase as function of age in retina, brain and liver. 3) In contrast the cysteic and cysteine sulphinate decarboxylase activities decrease with age in kidney, lung and spleen. 4) The rate of decarboxylation of cysteine sulphinate is higher than cysteic acid and the ratio of the two decarboxylating activities for each tissue is constant; this uniformity may exclude the existence of two separate enzymes.

Aging↗
PubMedDate not supplied

Collagenase-extractable proteoglycans from lesion-free areas of human aorta.

Different proteoglycan (PG) populations were isolated from normal human aorta by extraction of minced tissue with 4M GuHCl and by further digestion of the residue with collagenase. Dissociative extraction induced a complete disappearance of Alcian Blue positive material, which was demonstrable by transmission electron microscopy before the treatment around collagen fibrils and in pericellular areas. However, 4M GuHCl extraction solubilized only an average of 60% of aorta total hexuronate content. Collagenase treatment of the residue resulted in a complete loss of collagen fibril organization, which was coupled with a further hexuronate recovery, accounting for about one third of total tissue content. The bulk of PGs obtained in collagenase digest was retained by Sepharose CL-4B column. Their sulphated glycosaminoglycan (GAG) composition differed from PGs extracted with 4M GuHCl, containing only chondroitin sulphate (CS) and heparan sulphate (HS), without detectable traces of dermatan sulphate (DS). Moreover, they contained hyaluronic acid. The results obtained by agarose polyacrylamide gel electrophoresis (APGE) and Octyl-Sepharose chromatography, followed by further APGE and Sepharose CL-4B gel-filtration, carried out before and after treatment with Chondroitinase ABC and AC and Heparinase I and III, suggested that collagenase digest contained different PG populations, carrying mainly either CS or HS chains. Moreover, HS containing PGs showed higher hydrodynamic size and stronger properties of hydrophobic interactions than CS containing PGs.

Adult↗
PubMedDate not supplied

LDL interaction with proteoglycans isolated from human aortas with different atherosclerotic involvement.

BACKGROUND: Proteoglycan (PG)-LDL interaction is likely to be involved in lipid deposition in arterial wall. The relative content and the structural properties of different PG populations change in human aorta with atherosclerotic degeneration. Therefore, we extracted and separated these PGs from human aorta samples with increasing severity of atherosclerotic involvement and studied their interactions with human LDL. MATERIALS AND METHODS: PGs were extracted with 6 M urea, purified by ion-exchange chromatography and separated into two different populations (PGI and PGII) on the basis of hydrodynamic size and glycosaminoglycan composition. The interaction of both PGI and PGII with LDL was studied separately by precipitation assay. RESULTS: The ratio PGI/PGII decreased markedly with increasing severity of the disease. Both PGI and PGII formed insoluble complexes with LDL. However, the shape of saturation curves was markedly different. An excess of PGI from normal or intermediately affected aorta inhibited insoluble complex formation with LDL. On the contrary, an excess either of PGII or of PGI from severely affected aorta did not inhibit insoluble complex formation. In the case of PGII, the maximum of percentage cholesterol precipitated was higher when PGII from severely affected aorta was used. CONCLUSIONS: The different interactions of LDL with either PGI or PGII are likely to depend on the different structural properties of PGs. The decrease of PGI/PGII ratio following atherosclerotic degeneration could play an important role in lipid deposition in arterial wall.

Adult↗
PubMedDate not supplied

[Natural history of breast cancer: lobular carcinoma versus ductal carcinoma in our experience].

Aim of the study is to evaluate the biology, the clinical evolution and the prognosis of lobular carcinoma of the breast. We retrospectively evaluated the patients treated in our institution during the last 13 years. 117 patients with lobular carcinoma of the breast and 117 patients, randomized out of 397 patients with 'classical' pattern of ductal carcinoma were compared. Age distribution, type of surgery, tumor size, TNM stage, axillary lymph node involvement, multifocality, multiple breast cancers, local and distant recurrences, overall survival and disease-free survival have been evaluated. There was not a significant difference in tumor size, lymph node involvement, stage distribution, estrogens and progesterone receptors status, local and distant recurrences. The only significant differences were found in multifocality and multiple breast cancers. The said difference does not seem to modify the overall survival and the disease-free survival that are the same in the two groups. Our research shows that tumor size and axillary lymph node status are the only elements that have to be considered in the choice of the surgical treatment and prognosis. It seems that the difference in distant metastatic pattern between lobular and ductal carcinoma is the distinctive feature in the follow-up of these patients.

Breast Neoplasms↗
PubMedDate not supplied

Solitary hepatocellular adenoma in infancy.

Here is presented an exceptional case of liver cell adenoma in a five-year-old child. The neoplasm was diagnosed when the child was taken to hospital in a state of shock and coma because of the contemporary laceration of the neoplasm and of the spleen in consequence of a causal falling. The neoplasm is histologically defined, possible clinical pictures are described as well as the differential diagnosis and the tests useful for the diagnosis.

Accidental Falls↗
PubMedDate not supplied

[Our experience in the surgical treatment of early breast cancer. Results of a prospective study of 204 cases].

The authors report the results of a prospective study on 204 patients (1980-1993) affected by early infiltrating breast cancer (size pounds 2 cm) as a part of a surgical series of 608 cases. 53 cases who underwent QUART (25.9%) and 151 cases (74.1%) who underwent mastectomy modified according to Patey have been collected. 10 years actuarial survival has been respectively 79% after extensive surgery and 78% after conservative treatment. Local recurrences have been observed in 9 cases after meticulous follow-up (median 74.8 months, range 12-178): 3 (5.66%) patients after QUART and 6 (3.97%) after mastectomy; furthermore 1 patients after a conservative treatment (1.88%) has developed a second tumor at the same side probably dependent on the presence in the primary tumor of an extensive intraductal component. No correlations between histological features, grading, positive nodes, receptor status and local recurrences have been found. Only the age of patients looks significantly correlated with frequency of recurrences: 44.45% of local recurrences have been observed in patients less than 45 years old. Local recurrences after QUART have obliged, in all cases, to a radical mastectomy. Furthermore, frequency of distant metastases has been considered: after QUART percentage is lower (9.43%) than after radical mastectomy (13.9%). This consideration looks correlated with the longer follow-up of the later group. A multidisciplinary approach is advised but the most important role is played by surgery. In conclusion it is outlined that conservative surgery is addressed to selection and consenting patients.

Actuarial Analysis↗
PubMedDate not supplied

[Primary lymphoma of the breast. Three cases of non-Hodgkin lymphoma].

Primary and sole breast lymphoma is a very rare disease. With the review of our series of 616 cases operated on for breast cancer, only 3 cases (0.48%) of primary breast non-Hodgkin lymphoma (LNH) have been observed. The authors outline the problems concerning diagnosis and therapy of this rare disease: pathological and immunohistochemical aspects are discussed. They stress the importance of staging in order to plan a correct multidisciplinary approach.

Aged↗
PubMedDate not supplied

Cathechol-O-methyl transferase activity in the individual human platelet populations.

COMT activity is present in many animal tissues, but there is no evidence on the presence or the functional role of COMT activity in platelets. The present work reports the results obtained on COMT activity in the individual platelet populations separated by a discontinuous sucrose density gradient. In the young platelet populations the activity is remarkable higher than in the old and light populations. Low values of COMT activity in the old platelets may reflect platelet senescence.

Blood Platelets↗