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V Macchia

Publications and source records attributed to V Macchia.

At least 37 records · Page 2Linked to original sources
PubMed1990

Epidermal growth factor receptor and thyrotropin response in human thyroid tissues.

The content of epidermal-growth-factor receptor (EGFr) and its relation to TSH-response were examined in 27 malignant thyroid tumors (5 follicular, 6 papillary, 5 medullary, 11 anaplastic carcinomas) and in 30 tumor-like lesions (21 hyperplastic goiters and 9 toxic adenomatous goiters). Normal 12 thyroid tissues adjacent to benign tumors with no evidence of macroscopic or microscopic abnormalities were used as control. All thyroid plasma membranes tested showed specific EGF binding. In membranes from toxic adenomas (2.18 +/- 0.73 fmoles/mg protein) and papillary carcinomas (2.80 +/- 0.80) the EGF binding was similar to that of normal thyroid membranes (2.32 +/- 0.73). Hyperplastic goiters showed an EGF binding (4.4 +/- 0.82) slightly higher than normal tissue. The highest and the lowest EGF binding values were found in anaplastic (11.8 +/- 2.78) and medullary (0.50 +/- 0.39) carcinomas, respectively. An inverse correlation between EGFr content and TSH-response was found when anaplastic thyroid tumors were compared to tumor-like lesions. However no correlation was observed in medullary carcinomas which also failed to respond to TSH and in papillary carcinomas which partially respond to thyrotropin.

Cell Membrane↗
PubMed1990

Gangliosides and phospholipids in human thyroids responsive and unresponsive to thyrotropin.

The patterns of gangliosides and phospholipids and their relation to TSH response were examined in twenty-six malignant thyroid tumors (4 follicular, 6 papillary, 5 medullary, 11 anaplastic carcinomas) and thirty-six hyperplastic goiters. Thirteen thyroid tissues adjacent to benign tumors with no evidence of macroscopic or microscopic abnormalities were used as normal tissue. In normal thyroids the major ganglioside was GD3 (44%) and GM3 was the second ganglioside (20%). In minor amounts GD1a (8.6%), GD1b (6.2%), GT1b (5.7%) and GM1 (5.6%) were present. In hyperplastic goiters and in follicular carcinomas the patterns of gangliosides were similar to that of normal tissue except for GM3 which, in the last tissue, was higher (34%). In papillary carcinomas low levels of GM3 (11%) and GT1b (0.8%) with a high level of GD1b (12.6%) were found. In anaplastic carcinomas GM3 was very high (47%) whereas GD3 was low (18%). In these tumors also a high percentage (14.0%) of GD1a was found. In medullary carcinomas the lowest levels of GM3 (4%) with the highest level of GD3 (64%) were found. Although large differences of the gangliosides distribution were clearly encountered in the various pathological human thyroid, no correlation between lack of TSH response and some individual ganglioside could be made. No differences in the individual phospholipid in the various tissues studied were found.

Adenocarcinoma↗
PubMed1989

Hepatitis B virus infection among health care workers at an urban teaching hospital in southern Italy: a low occupational hazard?

A prevalence study of HBV serologic markers was carried out among hospital employees of ten departments of the Second School of Medicine in Naples, an urban area with a high prevalence of HBV infection. Departments and occupational categories were selected to represent a spectrum of different exposure to B virus infection. Workers in a large electronic plant in the same geographical area were screened as controls. HBsAg prevalence was 4.8% in the hospital community and 4.0% in control group. It rises to 4.3% in the Campania Region, where all screened workers live, and in some specific areas of the same region it rises to 12%. But no significant difference among seropositivities for at least 1 marker of HBV, considered to be a better indicator of occupational hazard, was found among personnel of different departments or belonging to different occupational categories. None of the occupational and non-occupational risk factors studied was found to be significantly associated with HBV infection. Two years later, an incidence study was carried out among susceptible subjects. Seropositivity for 1 marker was 2.2% among hospital workers and 2.8% in the control group. These figures are lower than the annual attack rate (5%) required for an acceptable cost-benefit ratio of vaccination against hepatitis B. Our results indicate that in a geographical area with HBV endemicity the occupational hazard for B virus infection is low in hospital workers because of the high number of the high number of immunized subjects and the contacts with infected people out of the hospital.

Family↗
PubMed1986

Alteration in the transmission of TSH-message to thyroid target in a transplantable rat thyroid tumor.

Plasma membranes derived from a transplantable rat thyroid tumor (line 1-5G in Wollman's classification), which is unresponsive to thyrotropin (TSH) but is responsive to dibutyryl 3', 5' cAMP, have been evaluated to localize the defect. TSH binding in tumor plasma membrane is slightly lower than in normal rat thyroid membranes. No change in affinity, but simply a lower capacity was observed. The glycoprotein component of the TSH receptor exhibits similar binding and solubilization properties to the glycoprotein component derived from normal rat thyroid. Analogously to normal rat thyroid membranes, gangliosides more complex than N-acetylneuraminylgalactosylglucosyl-ceramide (GM3) are also present in tumor line 1-5G membranes. Phospholipid content of tumor line 1-5G is 50% lower than that of normal rat thyroid. At variance also with normal rat thyroid, 32P incorporation in tumor line 1-5G phospholipids such as phosphatidylserine and phosphatidylethanolamine is not modified after in vitro incubation with TSH. An even more pronounced effect by TSH on 32P incorporation into phosphatidylinositol is evident in tumor line 1-5G by comparison to normal. The 1-5G thyroid tumor membranes has a 12-fold higher basal adenylate cyclase activity than that of rat thyroid membranes. The high basal adenylate cyclase activity is associated with high ADP ribosylation activity. Both enzymes of tumor are only slightly responsive to TSH. These results suggest that the block in the transmission of TSH message to the cell machinery is localized to the regulatory domains between TSH receptor and adenylate cyclase catalytic subunit.

Adenosine Diphosphate Ribose↗
PubMed1986

In vitro activation of adenylate cyclase of atrophic celiac intestinal mucosa by wheat gliadin-derived peptides.

In order to demonstrate that gliadin peptides may interact with cell membranes of celiac small intestinal mucosa, the capacity of these peptides to activate the cell membrane enzyme adenylate cyclase was tested. The addition of peptides from bread wheat purified A-gliadin and whole gliadin (proteins that are toxic for celiac patients) enhanced the adenylate cyclase activity of crude cell membrane preparations obtained from atrophic small intestinal mucosa of celiac patients. No activation of adenylate cyclase of this tissue was observed with peptides from proteins nontoxic for celiac patients (bread wheat albumin and maize prolamin). Gliadin peptides did not activate adenylate cyclase of morphologically normal small intestinal mucosa from normal subjects or from celiac patients in remission. These results, therefore, suggest that peptides from bread wheat gliadin may interact with cell membrane of atrophic small intestinal mucosa of celiac patients.

Adenylyl Cyclases↗
PubMed1985

Hepatitis B immunisation with a reduced number of doses in newborn babies and children.

74 healthy babies born to mothers positive for hepatitis B surface antigen (HBsAg) were randomly divided at birth to receive either HB immunoglobulin and 2 doses of HB vaccine 2 months apart, or HB immunoglobulin and 3 doses of HB vaccine 1 month apart. 80 healthy babies born to HBsAg, anti-HBs, and anti-HB core (c) negative mothers were randomly divided at birth to receive either 2 doses of vaccine 2 months apart or 3 doses 1 month apart. The seroconversion rates and the geometric means of anti-HBs titres were lower in both groups of babies given 2 doses of vaccine than in the groups given 3 doses. 60 pairs of children at risk, aged 1 to 12 years and HBsAg, anti-HBs, and anti-HBc negative, were randomly divided to receive either the 2-dose regimen or the 3-dose regimen. The seroconversion rates and the geometric means of anti-HBs titres were satisfactory in both groups.

Child↗
PubMed1984

Diamine oxidase in rat small bowel: distribution in different segments and cellular location.

Diamine oxidase (DAO) is an enzyme with high activity found in the small bowel mucosa of the rat and man, and only with very low activity in all other tissues. The present study was designed to investigate the enzymatic distribution along 8 consecutive small bowel segments of mucosa and to test the DAO concentration on brush border membranes obtained from whole mucosal homogenate in Wistar rats. Our data document that DAO activity is mainly distributed in intermediate and distal small bowel segments and is not significantly associated with enterocyte brush border.

Amine Oxidase (Copper-Containing)↗
PubMed1981

Cyclic nucleotide metabolism in differentiated and undifferentiated epithelial thyroid cells in culture.

A highly differentiated thyroid cell line (FR-RL) was compared with a less differentiated (FR-T Cl1) and an undifferentiated (1-5G) cell line. FR-TL is modulated in vivo and in vitro by thyrotropin and has the lowest adenylate cyclase and guanylate cyclase and the highest phosphodiesterase activities. In contrast, 1-5G tumor cells do not respond to thyrotropin and have the highest adenylate cyclase guanylate cyclase and lowest hydrolyzing enzyme activities. Intermediate enzyme activities were found in FR-T Cl1 cells. The differences between the two normal rat thyroid cell lines are not due to differences in the composition of the growth medium.

Adenylyl Cyclases↗
PubMed1981

Guanylate cyclase activity in Escherichia coli mutants defective in adenylate cyclase.

Guanylate cyclase, which catalyzes the synthesis of guanosine 3',5'-monophosphate, has been assayed in several strains of Escherichia coli. They include wild-type cells and mutants defective in adenylate cyclase, which is responsible for the synthesis of adenosine 3',5'-phosphate. Our results demonstrate that adenylate cyclase and guanylate cyclase are two different enzymes in E. coli and suggest that the gene that encodes adenylate cyclase also plays a regulatory role in the synthesis of guanylate cyclase.

Adenylyl Cyclases↗
PubMed1978

The adenylate cyclase-cyclic AMP-phosphodiesterase system in pathological human thyroid.

The adenylate cyclase-cyclic AMP-phosphodiesterase system of human thyroid tissues adjacent to cold nodules (control), two follicular adenomas, one hyperplastic thyroid and one hyperfunctioning follicular carcinoma have been compared. In the hyperfunctional follicular carcinoma the basal adenylate cyclase is much higher than in control tissue, carcinoma adenylate cyclase does not respond to TSH and prostaglandin E1, whereas it responds normally to fluoride. In the hyperplastic, but hypofunctional thyroid the basal adenylate cyclase is higher than in normal tissue whereas the response to TSH, PGE1, and fluoride is normal. No difference between the follicular adenomas and normal thyroid stimulated and unstimulated adenylate cyclase was observed. Furthermore in various thyroid tissues no changes in the level of cyclic AMP phosphodiesterase was found. Our data indicate a greater change in the synthesis rather than in degradation of cyclic AMP in the human pathological thyroids studied.

Adenocarcinoma↗
PubMed1978

[Guanyl cyclase in Escherichia coli. II. Identification and characteristics on the enzyme inhibitor].

The activity of guanylate cyclase and that of its inhibitor present in E. coli extract, have been separated through a linear KCl gradient on DEAE-cellulose column. The activity of the inhibitor is lost after ribonuclease treatment, whereas is strengthened by addition of poly (C). Other types of RNA synthetic homopolymers do not affect the inhibitor's activity. Chromatographic analysis of the products of guanylate cyclase measured in the presence of FI and FI plus poly (C), indicated that the inhibitor has a poly (C) dependent GTPase activity.

Deoxyribonucleases↗
PubMed1978

[Guanylate cyclase in E. coli. III. Purification and possible physiological role of GTPase].

A phosphohydrolase with a preferential activity for GTP has been isolated and partially purified from E. coli extracts. The enzyme purification has been achieved through precipitation by ammonium sulfate and chromatography on DEAE-cellulose, DEAE-Sephadex, Ultragel and a second DEAE-cellulose column. The phosphohydrolase activity is poly (C) dependent. The chromatographic analysis on PEI-cellulose has shown that the main product of GTP hydrolysis is GDP. The possibility that the enzyme partially purified in this work has an important role in the control of GTP availability as substrate for guanylate cyclase into the cells has been discussed.

Chromatography, DEAE-Cellulose↗