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Biomedical subjects

A Mastro

Publications and source records attributed to A Mastro.

14 recordsLinked to original sources
PubMed2003

Influence of muscle strength and total work on exercise-induced plasma growth hormone isoforms in women.

The purpose of this investigation was to determine the influence of physical strength and the ability to do more total work on human growth hormone (GH) variants to a heavy resistance exercise protocol in untrained women. From a distribution of 100 healthy, untrained women, the strongest 10 women (S) and the weakest 10 women (W) were compared for GH responses pre- and post an acute heavy resistance exercise test (AHRET, 6 sets of 10 RM squats, 2 minutes rest between sets). Blood samples were obtained pre-exercise and immediately post-exercise and subsequently analysed in total as well as fractionated by Sephacryl S-100R column chromatography into three molecular weight size classes: fraction A: > 60 kD, fraction B: 30-60 kD, fraction C: < 30 kD. For each total sample as well as each fraction, immunoreactive GH was measured via the Nichols IRMA, while bioactive GH was measured via the hypox rat tibial line bioassay and Diagnostic Systems Laboratory's immunofunctional GH ELISA. No exercise-induced changes or differences between groups were observed in the tibial line bioassay. However, the S group displayed a significantly higher pre-exercise resting value in the total fraction than the W group. Conversely, the W group exhibited a significantly higher pre-exercise value in the smaller molecular weight fraction C. With regards to the immunofunctional and immunoreactive assays, the total fraction, fraction A, and fraction B demonstrated significant (P < or = 0.05) exercise-induced increases in both the S and W group despite no group differences. For the Nichols and immunofunctional assays significant exercise-induced changes were observed in the smaller molecular weight C fraction in the W group but not the S group. However, the S group displayed a significantly higher pre-exercise value in fraction C relative to the W group. These data demonstrate for the first time that differences exist in the GH molecular weight variants between strong and weak untrained women, with the lower molecular weight variants seemingly less responsive to greater amounts of exercise in stronger women, thus suggesting differential regulation of GH molecular weight variants during resistance exercise due to pre-existing physical parameters.

Animals↗
PubMed2000

The isolation and properties of the dimeric subunit of concanavalin A.

Concanavalin A (Con A) was dissociated into dimeric and monomeric subunits by incubation at 37 degrees C in acetate buffer of pH 3.8 containing 0.5% sodium dodecyl sulfate. The dimer was isolated in pure form by a density gradient ultracentrifugation method. Several properties of the dimer were determined including the formation of a precipitin with anti-Con A antibodies, the molecular weight, the lack of a binding site for glycogen, the lack of mitogenic activity for spleen lymphocytes, and the lack of inhibition by alpha-methyl D-glucoside. The latter findings differ from results reported by other investigators.

Chromatography, Affinity↗
PubMed1998

Detection of high mobility group I HMGI(Y) protein in the diagnosis of thyroid tumors: HMGI(Y) expression represents a potential diagnostic indicator of carcinoma.

Hyperplastic or neoplastic proliferative lesions of thyroid follicular epithelium consist of a spectrum, ranging from nodular hyperplasia to undifferentiated (anaplastic) carcinoma, and usually present as palpable thyroid nodules. Thyroid nodules are a common occurrence in the general population, but only a small proportion of them are eventually diagnosed as carcinoma. The difficulty in objectively identifying those thyroid nodules that are malignant to avoid unnecessary surgery, combined with the range and effectiveness of the available therapeutic options in those patients who do, indeed, have thyroid carcinoma, has prompted the search for tumor markers and prognostic indicators. The high mobility group I (HMGI) proteins represent a class of nuclear proteins involved in the regulation of chromatin structure and function. HMGI(Y), one of the members of this class, is expressed at high levels during embryogenesis and in malignant tumors but at generally low levels in normal adult human tissues. Previous work on a limited number of thyroid samples suggested that the detection of the HMGI(Y) proteins may provide a clinically useful diagnostic tool. To verify this assumption, we analyzed HMGI(Y) expression by a combination of immunohistochemistry and reverse transcription-PCR in 358 thyroid tissue samples that were representative of the spectrum of thyroid tumor pathology. HMGI(Y) was detectable in 18 of 19 follicular carcinomas, 92 of 96 papillary carcinomas, and 11 of 11 undifferentiated (anaplastic) carcinomas but in only 1 of 20 hyperplastic nodules, 44 of 200 follicular adenomas, and 0 of 12 normal tissue samples. The correlation between HMGI(Y) expression and a diagnosis of carcinoma was highly significant (P < 0.0001). We also prospectively collected and analyzed for HMGI(Y) expression by immunohistochemistry and reverse transcription-PCR in 12 fine needle aspiration biopsies from 10 patients who subsequently underwent surgical removal of a solitary thyroid nodule. HMGI(Y) was detectable only in the four fine needle aspiration biopsies, corresponding to the thyroid nodules that were definitively diagnosed as carcinomas after surgery (two follicular carcinomas and two papillary carcinomas). The remaining eight samples (six follicular adenomas and two samples consisting of normal follicular cells) were negative. The findings of this study confirm the differential expression of HMGI(Y) in thyroid neoplasia and indicate the HMGI(Y) protein as a potential marker for thyroid carcinoma.

Adenocarcinoma, Follicular↗
PubMed1995

RET/PTC oncogene activation is an early event in thyroid carcinogenesis.

RET/PTC oncogene activation occurs in about 20% of human thyroid papillary carcinomas. However, it is not known yet whether it is an early or late event in the process of thyroid carcinogenesis. Here we demonstrate, by using a combined immunohistochemical and reverse transcriptase-polymerase chain reaction based approach, that RET/PTC activation is present in 11 out of 26 occult thyroid papillary carcinomas analysed. Therefore, we conclude that it represents an early event in the process of thyroid cell transformation.

Base Sequence↗
PubMed1993

Immune changes in test animals during spaceflight.

Over the past two decades, it has become apparent that changes in immune parameters occur in cosmonauts and astronauts after spaceflight. Therefore, interest has been generated in the use of animal surrogates to better understand the nature and extent of these changes, the mechanism of these changes, and to allow the possible development of countermeasures. Among the changes noted in animals after spaceflight are alterations in lymphocytic blastogenesis, cytokine function, natural killer cell activity, and colony-stimulating factors. The nature and significance of spaceflight-induced changes in immune responses will be the focus of this review.

Animals↗
PubMed1970

DNA synthesis in the anterior pituitary of the male rat: effect of castration and photoperiod.

Castration increased incorporation of tritiated thymidine into total DNA in the anterior pituitary gland. Furthermore, there was a threefold increase in the percentage of labeled basophils 1 month after castration. Exposure of rats to constant light or dark also changed DNA synthesis; these changes depended on age of the animal and on exposure length. The results reflect physiologically induced mitotic activity in specific classes of pituitary cells and further suggest that neuroendocrine mechanisms may be involved in control of cell turnover in the gland.

Animals↗
PubMedDate not supplied

A multicentric phase II clinical trial on intra-arterial hepatic radiotherapy with 90yttrium SIR-spheres in unresectable, colorectal liver metastases refractory to i.v. chemotherapy: preliminary results on toxicity and response rates.

BACKGROUND: In patients locally progressing after two lines of chemotherapy, some locoregional approaches showed encouraging results in terms of local control of disease. The aim of our study was to evaluate toxicity, clinical response and quality of life in 48 patients with unresectable colorectal liver metastases submitted to selective internal radiotherapy (SIRT). MATERIALS AND METHODS: Up to now 35 patients with unresectable colorectal liver metastases, refractory to two lines of chemotherapy, underwent intra-arterial infusion of resin microspheres with yttrium-90 (SIR-spheres). Pre-treatment evaluation included a CT scan, blood tests, a PET scan and arteriography of celiac trunk, hepatic and superior mesenteric artery; extrahepatic uptakes and pulmonary shunts more than 10% were excluded by a Scinti-scan. The gastroduodenal artery was embolized before the SIR-spheres injection. Other exclusion criteria were liver dysfunction and anatomical vascular anomalies. The clinical response was evaluated by CT-scan following the RECIST criteria. Median follow-up was 4 months. RESULTS: Median number of metastases was 4 (range, 1-15), 38% of cases presenting hepatic involvement < 25%. The median SIRT dose delivered was 1.7 GBq. Median pulmonary shunt was 6%. No operative mortality occurred; early toxicity (within 48 hours) was 20.6%, shown as fever, acute pain and leucocytosis. The late toxicity was 24.1% with chronic pain, jaundice and nausea being the most frequent. All the toxic events were graded 2 or 3 according to the WHO scale. Preliminary results were available in terms of clinical response after 6 weeks: 12.5% had a partial response, 75% a stable disease, while progression of disease, was observed in 12.5% of the patients. CONCLUSION: SIRT is a safe treatment in terms of acute and late toxicity. Intra-arterial microspheres could represent a good therapeutic option for patients with progressing liver metastases only, after two lines of systemic chemotherapy.

Antineoplastic Agents↗