Search PubMed⌕ Search

Biomedical subjects

G Salvatore

Publications and source records attributed to G Salvatore.

At least 55 records · Page 3Linked to original sources
PubMed1996

Prognostic significance of nucleolar organizer regions in meningiomas.

The argyrophilic method for the demonstration of nucleolar organizer region-associated proteins (AgNOR's) was applied to paraffin-embedded histologic sections of 30 meningiomas. These were divided into three groups: 1) group I comprising 10 primary tumors which subsequently recurred within five years; 2) group II including the relative recurrences of the above mentioned primary tumors; 3) group III consisting of 10 nonrecurrent tumors over a follow-up of at least five years. The means of AgNOR counts were 1.58 with a SD of 0.67 for the group I, 1.47 with a SD of 1.04 for the group II, and 1.42 with a SD of 0.62 for the group III. A statistical analysis of these data using the Student's "t" test showed no significant difference between primary tumors and relative recurrences, as well as between primary and nonrecurrent tumors. However, when the AgNOR number was > 2.0 there was a statistically significant difference between primary and nonrecurrent meningiomas. These results are discussed in light of the findings previously reported by the literature.

Humans↗
PubMed1994

An assessment of the in vivo clastogenicity of erythrosine.

In an investigation of the in vivo clastogenic potential of the food colouring erythrosine (ER), male B6C3F1 mice were treated by ip injection at doses of 50, 100 and 200 mg/kg, repeated 24 hr apart. Signs of toxicity were observed at the highest dose of ER administered. The three cytogenetic endpoints analysed were sister chromatid exchanges (SCEs) in peripheral blood lymphocytes (PBLs), micronuclei in bone marrow polychromatic erythrocytes (PCEs), and micronuclei in peripheral blood reticulocytes (PBRs). SCE frequencies in PBLs were 4.13, 4.58, 4.33 and 4.60 SCE/cell at 0, 50, 100 and 200 mg ER/kg, respectively. At the same doses, the frequencies of micronucleated PCEs were 3.5, 3.2, 2.0 and 2.5/1000 PCEs. Micronuclei in PBRs ranged from 1.2 to 3.6 and from 1.4 to 3.0/1000 PBRs in control and treated mice, respectively. These results indicate that ER is inactive as a clastogen in mouse blood and marrow cells. This result supports the hypothesis of a non-genotoxic mechanism for ER carcinogenicity.

Animals↗
PubMed1993

Preferential sites of proteolytic cleavage of bovine, human and rat thyroglobulin. The use of limited proteolysis to detect solvent-exposed regions of the primary structure.

The sites and the sequence of the proteolytic cleavages of bovine, human and rat thyroglobulin, during the limited proteolysis with thermolysin and trypsin, were determined by sequencing the NH2 termini of the peptides produced and comparing them to the cDNA-derived sequences of bovine, human and rat thyroglobulin. Major cleavage sites of bovine thyroglobulin included residues 240, 502, 993, 1218, 1784 with thermolysin, and 240, 520, 1142, 1783, 2515 with trypsin. Cleavage sites of human thyroglobulin included residues 503, 982, 990, 1405, 1831 with thermolysin, and 522, 1627, 2513 with trypsin. Those of rat thyroglobulin included residues 501, 1776, 1784 with thermolysin, and 522, 1771, 1825, 2515 with trypsin (numbered as in bovine thyroglobulin). Thus, thyroglobulin from various species presents well localized and conserved regions particularly sensitive to proteolysis. The most sensitive region extended for 30 residues after residue 500. Another major cluster of cleavages was centered around residue 1800; this region was only partially sensitive in human thyroglobulin. A conserved tryptic site lay at the COOH terminus of the molecule. Most cleavage sites occurred within the inserted sequences that disrupt the Cys-rich, tandem repeats of thyroglobulin and either contain or are located near exon-intron junctions. Several cleavage sites lay in proximity of early iodinated or hormonogenic tyrosyl residues or of putative N-linked glycosylation sites. While a predominantly beta-type secondary structure and a rigid three-dimensional structure were predicted for the Cys-rich repeats, stretches of predicted alpha-helices, beta-strands and irregular structure were interspersed in the regions surrounding the cleavage sites. These data demonstrate the existence of conserved regions of thyroglobulin inherently sensitive to proteolysis, which most likely represent solvent-exposed regions of the primary structure, possibly forming loops at the surface of thyroglobulin.

Amino Acid Sequence↗
PubMed1993

Immortalization of a cell line showing some characteristics of the oligodendrocyte phenotype.

We have used the polyoma middle T oncogene to immortalize cells from rat embryo encephalon. Immunostaining experiments with monoclonal antibodies demonstrated that the cells of one of the obtained lines, named CEINGE CL3, are stained by anti-vimentin and anti-S100 antibodies, are not stained by anti-neurofilaments (NF) or anti-glial fibrillary acidic-protein (GFAP) antibodies. Only a subset of the CEINGE CL3 cells (20-30%) is stained by an anti-galactocerebroside antibody. Northern blot analysis demonstrated that these cells express low levels of proteolipid protein mRNA, whereas polymerase chain reaction (PCR) amplification failed to evidentiate the presence of both NF and GFAP mRNAs. Either retinoic acid or forskolin treatments or a combination of them are able to induce morphological changes that are accompanied by a complete growth arrest.

Animals↗
PubMed1993

p53 protein in aggressive and non-aggressive basal cell carcinoma.

Basal cell carcinoma (BCC) is the most frequent cutaneous neoplasm, with a generally favorable clinical behavior. Sometimes, indeed, it recurs after therapy and/or metastasizes. As point mutations in the coding sequence of the p53 tumor suppressor gene have been implicated in the progression of many human tumors, we studied the expression of p53 protein on this neoplasia. We tested immunohistochemically the positivity for p53 protein (NCL-p53-CM1, YLEM) on 19 cases of morphologically "non aggressive" BCC (BCC1) and on 19 "aggressive" BCC (BCC2), all with one or more relapses and 3 with distant metastases also. Results were related to clinico-pathological and follow-up data. All but one BCC2 were found positive for p53 protein. Conversely, only 2 cases of BCC1 exhibited low immunoreactivity for p53 protein, with high statistical differences between the two groups. No correlation was found between the immunoreactivity, age of patients, and site of the lesions. The availability of immunohistochemistry and the relatively easy interpretation of the results make screening for p53 protein a possibly useful tool in the prognostic evaluation of BCC.

Adult↗
PubMed1992

The origin of the electrophoretic doublet of thyroglobulin.

Bovine and human thyroglobulin show two closely migrating bands in reducing SDS-PAGE. Limited digestion with chymotrypsin, trypsin and thermolysin converted the slower band of the doublet into a peptide identical to the faster band, with an apparent mass of 270 kDa, in both species. The starting point of the faster band of the doublet was established at Ileu 520 with native bovine Tg and at Ser 503 with native human Tg, and at Ser 503 and Ser 504 with chymotrypsin-digested bovine and human Tg, respectively. These data explain the electrophoretic heterogeneity of thyroglobulin and unveil a region highly susceptible to proteolysis at about 500 residues from the NH2-terminus of the molecule.

Amino Acid Sequence↗
PubMed1992

Nucleolar organizer regions in aggressive and nonaggressive basal cell carcinoma of the skin.

Nucleolar organizer regions (NOR) were investigated on routine paraffin-embedded histologic sections of 11 aggressive basal cell carcinomas that recurred and/or metastasized (BCC2) and 11 nonaggressive basal cell carcinomas (BCC1). The absolute number of NOR per nucleus was higher in BCC2 than in BCC1, and their distribution pattern was also different. In fact, the means of argyrophilic staining of NOR (AgNOR) counts in the two groups of tumors by two observers were 6.56 with a SD of 1.98 for the nonaggressive and 9.48 with a SD of 2.12 for the aggressive basal cell carcinomas. A statistical analysis of these data using the Student's t test confirmed these observations (t = 64.49). Problems in the evaluation of NOR and possible comparison with other experiences are also discussed. The authors conclude that a quantitative assay of AgNOR and perhaps their distribution pattern may provide information useful to recognize BCC2 and hence may be of help in their prognostic prediction.

Adult↗
PubMed1990

The earliest site of iodination in thyroglobulin is residue number 5.

In most highly structured native proteins, as well as in thyroglobulin, the reactivity in vitro of the various tyrosyl residues toward iodine is widely different. The present work demonstrates that of nearly 70 tyrosyl residues present in rat thyroglobulin, there is one, residue number 5 from the NH2-terminal end, which has in vivo the highest affinity toward iodine, being the first one to be iodinated. In fact, when 6-(n-propyl)-2-thiouracil (PTU)-treated, iodine-deficient animals were injected with 125I and killed shortly after, we isolated from thyroid glands poorly iodinated thyroglobulin (about 1 iodine atom/thyroglobulin molecule), nearly 90% of the radioactivity of which was found as monoiodotyrosine. Although CNBr cleavage of this protein gave several fragments after gel electrophoresis only one of these, with apparent mass 27,000 Da, contained 125I. This fragment was isolated and fully characterized. Twelve cycles of automated Edman degradation were performed; the sequence found, i.e. N-I-F-E-X-Q-V-X-A-Q-X-L, indicated that the 27,000-Da fragment is the NH2 terminus of thyroglobulin. This portion of the polypeptide chain contains several tyrosyl residues which may well all be potentially involved in the early iodination of the protein. The observation that the removal of seven amino acids from the NH2 terminus is accompanied (at the fifth step) by the total disappearance of radioactivity in the resulting shortened peptide suggested that the fifth residue was the only one iodinated under these conditions. A second, more quantitative experiment was performed on thyroglobulin obtained from 6-(n-propyl)-2-thiouracil-treated animals whose death was postponed 24 h after the injection of 125I. In this case the radioactivity was found not only in a single CNBr fragment (27,000 Da) but also in other discrete species of lower molecular mass. The mixture of these peptides was subjected to seven steps of manual Edman degradation. Fragments before and after partial degradation were run in parallel on a polyacrylamide gel and the distribution of 125I compared. Besides some change in the background, the two profiles were identical except for the absence of the 27,000-Da species. This proves that all the 125I present in the 27,000-Da species was localized at the fifth residue, the same site at which the hormone molecule is preferentially synthesized under normal conditions. This result is not unexpected and is in accord with the known properties of thyroglobulin which has a polypeptide chain designed for efficient synthesis of the hormone even at low levels of iodination.

Amino Acid Sequence↗
PubMed1990

Cerebellar ataxia and hypogonadism. A clinicopathological report.

A female showed primary amenorrhea and slowly progressive ataxia of limbs and gait, that had started when she was 18 years old. Endocrine data were consistent with hypogonadotropic hypogonadism. She died at 35 years of age. Post mortem examination showed mucinous carcinoma of the lung, hypoplastic uterus, atrophic ovaries. The cerebellum was small, with the atrophy most marked in the vermis, and the pons was shrinked. There was almost complete Purkinje cell disappearance and neuronal loss in the granular layer and the inferior olives.

Adult↗
PubMed1990

Adult Fanconi syndrome and liver cirrhosis.

A female presenting primary adult Fanconi syndrome and liver cirrhosis of obscure aetiology is described. The only other report of this association appeared over four decades ago and concerned a male patient who, however, was subsequently diagnosed as having Wilson's cirrhosis, a well-known cause of acquired Fanconi syndrome. Therefore, the present report is the first account of primary Fanconi syndrome with authentic cryptogenic liver cirrhosis. Since the chronic urinary amino acid leakage is not a pathogenetic mechanism of the cirrhotic process, we believe that this association in fortuitous.

Fanconi Syndrome↗
PubMed1988

Macro- and microscopic alterations in 2 rabbit skin regions following topically repeated applications of benzoic acid n-alkyl esters.

This paper explores the irritancy potential of n-alkyl benzoate preservatives (methyl benzoate, MB; ethyl benzoate, EB; n-propyl benzoate, n-PB; n-butyl benzoate, n-BB), allowable in cosmetic formulations. Comparative experiments were carried out involving repeated daily application for all compounds (up to maximum of 6 days) on clipped rabbit skin in 2 distinct regions: the dorsum (0.5 ml per treatment) and the external surface of the outer ear (0.2 ml per treatment). According to the different anatomo-physiological features, benzoates elicited dissimilar reactions in the dorsum and the external ear. In the first mentioned area, there were widespread inflammatory reactions accompanied, in some cases, by necrotic changes and slight epidermal hyperplasia; on the other hand, hyperplasia was the most prominent and earliest alteration in the ear. The irritancy potential was closely related to the duration of treatment as well to the increase in the molecular weight of benzoates.

Administration, Topical↗
PubMed1985

Coated vesicles from the thyroid gland: isolation, characterization, and a search for a possible role in thyroglobulin transport.

We report the first isolation of purified coated vesicles (CVs) from thyroid gland. Bovine thyroid CVs were isolated by differential centrifugation, including a step through sucrose-D2O, using a modification of the method described by Nandi et al. (1) for bovine brain CVs. The CVs were characterized by electron microscopy, sedimentation properties, and SDS-PAGE of the protein components. Thyroglobulin (Tg) was found to be associated with the purified CVs. When the thyroid CVs were exposed to conditions known to remove the protein coat from brain CVs, such as low ionic strength at pH 8.5, most of the Tg dissociated from the vesicles along with the coat proteins. Moreover, the Tg remaining with the uncoated vesicles (UVs) was trypsin sensitive, and therefore judged to be associated with the external surface of the vesicle. Since ligand-receptor complexes are normally located within CVs and not on their outer surface, no evidence was found for Tg-receptor complexes within thyroid CVs. Thyroid slices were incubated in the presence of [35S] methionine with subsequent isolation of labeled CVs in order to study the incorporation of newly-synthesized proteins into these structures. At 0.5 and 2 hours of incubation, the 180K MW subunit of clathrin, as well as other proteins, but not Tg, had become labeled in the purified CVs. Extracellular 19S-[35S] thyroglobulin was isolated from the incubation medium, however, demonstrating release of newly-synthesized Tg (presumably into cut follicles). It is concluded that thyroid CVs do not seem to be involved in the secretion of newly-synthesized Tg from the rough endoplasmic reticulum into the follicular lumen. While a possible role of thyroid CVs in the reabsorption of small quantities Tg by micropinocytosis cannot be completely excluded, the present data do not support a primary role for thyroid CVs in either endocytosis or exocytosis of Tg.

Animals↗
PubMed1985

Effects of an overload of animal protein on the rat: brain DNA alterations and tissue morphological modifications during fetal and post-natal stage.

On account of many literature reports about the definite correlation between high animal protein intake and cardiovascular diseases, we have studied the effect of a hyperproteic purified diet (casein 40%, lactalbumin 20%) on fetal and post-natal (not further than 40th day) stage of the rat, when cell subdivision process is faster and therefore damage by nutritional imbalance is certainly more serious. Litters of rats were grouped according to mother's (either hyperproteic or common basic) and rat's (after lactation) diet. Brain DNA and histology of various organs were studied. Hyperproteic diet during fetal stage and lactation would inhibit brain cell subdivision since overall content of brain DNA would be decreased on autoptic finding. Structural changes were also shown in liver, heart, kidney and adrenal cortex, especially when hyperproteic diet was continued even after lactation.

Adrenal Cortex↗