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Biomedical subjects

A Castelli

Publications and source records attributed to A Castelli.

At least 91 records · Page 5Linked to original sources
PubMedDate not supplied

[Advanced gastric adenocarcinoma with RER+ phenotype presents a good prognosis after 5 years of curative resection].

Microsatellite instability (MIN) has been found both in advanced and early gastric cancer. To find out the step played by MSI in gastric carcinogenesis, links between RER+ phenotype and clinical and pathological aspects have been studied. In this work our purpose is to analyze the relationship between MIN+ advanced gastric cancer and prognosis at 5 years after radical surgery. We investigated 34 patients affected by gastric cancer who underwent R0 surgical resection from February 1991 to October 1994. After that, they underwent a four-monthly follow-up for a minimum of 5 years. Genetic abnormalities have been searched including (a) those occurring in common-type CIN carcinomas and (b) those characteristic of MIN cancers. DNA extraction showed the presence of microsatellite instability (MIN) in 9 (26%) of the samples (vs. 74% of chromosomal instability CIN); none of them was M+ (vs. 12% of CIN cancers). Recurrence occurred in 2 out of 9 of the MIN cancers (22%) and in 21 out of 25 CIN cancers (84%). In conclusion, our data suggest that advanced gastric cancers with mutator phenotype show a better outcome at 5 years than the CIN phenotype.

Adaptor Proteins, Vesicular Transport↗
PubMedDate not supplied

[Results of the surgical treatment of primary gastric lymphoma].

The aim of the study was to verify the long term results obtained in primary gastric lymphoma with a strategy consisting in surgery as first-line treatment. Over the period from January 1988 to December 1999, 44 patients with histologically proven primary gastric lymphoma underwent surgical treatment in the First Department of General Surgery of the University of Verona. Tumours were staged according to the Ann Arbor classification and divided, according to the Kiel classification, into high- and low-grade lymphoma. Patients received adjuvant chemotherapy depending on the grade of malignancy and/or completeness of resection. Of the 44 patients, 40 (90.9%) underwent curative resections, i.e. with complete macroscopic and microscopic tumour removal (R0), consisting in total gastrectomy in 34 cases and subtotal gastrectomy in 6. Twenty-five of 40 patients had stage IE and 15 stage IIE tumours. Adjuvant chemotherapy was given to 33 patients (30 high-grade lymphomas and 3 low-grade lymphomas with N2 metastases). The overall cumulative 10-year survival rate in patients who underwent R0 resection was 79% without any significant differences in 10-year survival between patients with high- and low-grade malignancy (both 79%; P = 0.582) or between patients with or without lymph node metastases (91% and 70%, respectively; P = 0.426). In conclusion, the present investigation suggests that surgery yields prolonged complete remission in a high percentage of patients affected by gastric lymphoma irrespective of histopathologic grade of the disease and nodal involvement.

Adult↗
PubMedDate not supplied

[Significance of health education in schools. Strategy for the prevention of cardiovascular diseases].

Cardiovascular diseases are the first cause of death in our Country. They mainly manifests in adult age but it is the result of initiated lesions since the young age and imputable often to errors of behaviours and to non appropriate styles of life. The knowledges related to the prevention of some illnesses, allows a reduction of the incidence of these, a reduction of the mortality, with consequent reduction of the health and social costs related to the care and to the rehabilitation. In our educational system, unlike what happens in the most greater part of the other European countries, these themes are only partially present and however treated in sporadic and insufficient way. For these raisons Pronto Cuore onlus Association has decided to start, in collaboration with the Regione Lazio, a project of health education to the high schools students considering that a more informed population has a longer expectancy of life and a better life quality. This job wants to underline the necessity to undertake a health education program to teach and inform students and teachers: to recognize some factors of risk as principal causes of cardiovascular diseases; to change life style; to recognize critical situations and behaviours to be adopted.

Cardiovascular Diseases↗
PubMedDate not supplied

(Na+-K+)-ATPase interaction with L-ascorbic acid. Effect on p-nitrohenylphosphatase partial reaction.

L-ascorbic acid preincubation with rabbit kidney (Na+-K+)-ATPase inhibits the activity of p-nitrophenylphosphatase partial reaction with a pseudo-first order decay. The presence of the pseudosubstrate, p-nitrophenylphosphate, counteracts the inhibiting effect. During the reaction course, the kinetic rate is enhanced at ascorbic acid concentrations below 0.7 mmol/1, but is inhibited above that amount. The intrinsic fluorescence of the enzyme in E1 and E2 conformations is modified suggesting the occurrence of ascorbate-induced intermediate forms, distinct from those provoked by the addition of cations, magnesium and phosphate. These destabilized forms appear easier to be converted into catalytically active or increasingly inhibited states.

4-Nitrophenylphosphatase↗
PubMedDate not supplied

The kinetics of concurrent instantaneous and time dependent inhibition of alkaline phosphatase by urea and related compounds.

Urea, thiourea and guanidine-HCl greatly inhibit bone Alkaline Phosphatase activity. The inhibition displays saturation kinetics, fitting a model for the reaction sequence in which formation of complexes with increasing affinity occurs. The time dependent inactivation by urea and guanidine follows pseudo-first order kinetics, while thiourea behaviour is better described by a biexponential equation. The pH variation strongly affects the activity, the instantaneous inhibition and the time dependent inactivation. At the pH optimum the three compounds display their strongest effect. Data analysis suggests a three-stage model for the kinetics of Alkaline Phosphatase inhibition by urea and related compounds, involving a consecutive binding process with several sites of the protein and the production of different and interchanging inhibitor-enzyme complexes, leading to irreversibly inactivated forms.

Alkaline Phosphatase↗
PubMedDate not supplied

Comparison of kinetic and optical changes during guanidine denaturation of intestinal alkaline phosphatase.

The modifications of the activity of calf intestinal Alkaline Phosphatase treated with moderate amounts of guanidinium chloride are compared with the conformational changes observed by ultraviolet absorbance and intrinsic fluorescence. The time course of catalytic and optical properties of the treated enzyme develops through two distinct steps: an instantaneous and a time-dependent one. The immediate effect of guanidine is to lower emission yield, to shift the emission maximum of the enzyme to longer wavelengths and to enhance the absorbance of the protein. The rapid conformational transition determines a paradoxical activation at low effector concentration (below 0.88 M) and an inhibition at higher amounts. The following marked decay of enzyme activity with time is related to spectroscopically detectable changes. Temperature influences both kinetic and structural aspects of the process and facilitates guanidine action.

Alkaline Phosphatase↗
PubMedDate not supplied

Vitamin C-bovine serum albumin binding behaviour.

The binding of ascorbic acid and dehydroascorbic acid to bovine serum albumin is greatly heterogeneous. The Hill plots, as evaluated from the fluorescence quenching measurements, clearly show a biphasic behaviour. Scatchard analysis moreover indicates that the potency and the pattern of the binding can change gradually in the process of occupation of various sites because of albumin structural modifications.

Ascorbic Acid↗
PubMedDate not supplied

Modification of arginine residues in calf intestinal alkaline phosphatase.

Calf intestinal alkaline phosphatase is inactivated by 2,3-butanedione and phenylglyoxal. The reaction with either reagent results in a biphasic loss of enzymatic activity. Inactivation by 2,3-butanedione in borate buffer can be reversed after gel-filtration in Tris buffer but no enzyme reactivation is observed after phenylglyoxal treatment. Phosphate, ATP and NADH protect the enzyme from both compounds while no protection is displayed by L-phenylalanine. The selective chemical modification indicates that two differently reacting types of arginines are present in the active site domains of the dimeric enzyme.

Alkaline Phosphatase↗