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Biomedical subjects

A Marotta

Publications and source records attributed to A Marotta.

32 records · Page 2Linked to original sources
PubMed1995

Reduced bone mineral content and normal serum osteocalcin in non-steroid-treated patients with juvenile rheumatoid arthritis.

OBJECTIVES: To distinguish the effects of juvenile rheumatoid arthritis (JRA) on bone mineralisation from those possibly caused by steroid therapy. METHODS: Bone mineral status was evaluated in 20 children (five boys and 15 girls) with active JRA who never received steroids. Seven had oligoarticular, nine had polyarticular, and four had systemic JRA. Bone mineral content (BMC) was assessed by single beam photon absorptiometry and expressed as a Z score relative to normal values in healthy children. Serum calcium, phosphate, and alkaline phosphatase were measured by colorimetric methods. Whole parathyroid hormone was assayed by Immuno Radiometric Assay. Serum osteocalcin was measured by specific radioimmunoassay. Nutrient intake was assessed by a 24 hours dietary recall. BMC and nutrient intake were also assessed in an age and sex matched control group. RESULTS: BMC was -1.5 (SEM 0.8) Z scores in patients and 0.4 (0.3) in the control group (p = 0.02). BMC averaged -4.9 (2) Z scores in the systemic JRA group, -1 (0.6) in the polyarticular group and 0.3 (0.7) in oligoarticular JRA patients. Serum calcium, phosphate and osteocalcin values were normal in all patients. No significant difference was found between JRA patients and controls in calcium, phosphate, energy, and protein intake. CONCLUSION: JRA subjects have significantly reduced BMC even in the absence of any steroid therapy. Bone demineralisation appears to depend more on disease activity and on reduced motility than on reduced nutrient intake.

Adolescent↗
PubMed1991

Cerebrospinal fluid beta-2-microglobulin in HIV-1 infection, as a marker of neurological involvement.

Cerebrospinal fluid (CSF) and serum concentration of beta-2-microglobulin (beta-2-m) were evaluated in 30 patients in various stages of HIV-1 infection. CSF beta-2-m and CSF/serum ratio were significantly higher in patients with neurological complications respect to asymptomatic subjects. These findings indicate that CSF beta-2-m and CSF/serum ratio may be a useful marker of neurological involvement in HIV-1 infection.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Investigation of the Mek-MAP kinase-Rsk pathway in human breast cancer.

BACKGROUND: Mitogenic signaling through the principal growth factor receptor tyrosine kinase (RTK) pathway, i.e. RTK-->Ras-->Raf-->Mek-->MAPK has been implicated in the pathogenesis of human cancer. However, biochemical characterization of this has not been adequately assessed in human cancers. MATERIALS AND METHODS: Using extracts from 23 human breast cancers and control tissue from the same resected specimens, the protein levels, phosphotransferase activities and subcellular locations of the mitogen-activated protein (MAP) kinase isoforms p42 Erk2 and p44 Erk1 were examined, together with their phosphotransferase activities towards myelin basic protein (MBP) and a peptide substrate patterned after the Thr-669 site in the epidermal growth factor receptor (EGFR T669) that is phosphorylated by MAP kinase. RESULTS: Overexpression of both Erk2 and Erk1 isoforms was evident using specific antibodies. A universal activation of MBP and EGFR T669 peptide phosphotransferase activities was also found (up to 3-fold). MonoQ fractionation resolved the bulk of the EGFR T669 peptide phosphorylation from elution of the MAP kinase protein. Erk1 and Erk2 activities determined by specific immunoprecipitation were increased by up to only 2.5-fold in only 50% of tumors overall. Immunohistochemical studies, using a monoclonal antibody specific for Erk2 demonstrated that the cellular distribution of this MAP kinase was similar in both control and tumor tissues, and Erk2 was largely confined to normal and malignant acini, whilst the intensity of staining was actually reduced in the tumor tissue. Mek1 and especially Mek2 protein expression, as well as MAP kinase kinase activity as determined by phosphorylation of kinase-inactive Erk [GST-K71A] were increased in cancer samples. CONCLUSIONS: a) This confirms that MAP kinase activity is increased in human breast cancer. However, the frequency and magnitude of this change is dependent upon the chosen methodology (i.e. crude lysate assays versus specific immunoprecipitation). b) A MAP-kinase-independent source of increased EGFR T669 phosphotransferase activity in tumor extracts has been demonstrated for the first time in human breast cancer. c) By immunohistochemistry, Erk2 protein was actually found to exhibit lower intensity in tumor samples; the increased expression was most likely due to its increased distribution. d) Increased Mek protein expression and activation have been demonstrated for the first time in human breast tumors.

Anion Exchange Resins↗
PubMedDate not supplied

Differential cyclin-dependent kinase expression and activation in human colon cancer.

BACKGROUND: Abnormalities of the cyclin-dependent protein kinase (CDK) machinery have been linked to cancer development. Hyperphosphorylation of the retinoblastoma (Rb) protein results in release from inhibition of progression through the G1 phase of the cell cycle. Hyperexpression of CDK1 and CDK2 may enable progression through late G1, S and the G2 phases of the cell cycle. METHODS/RESULTS: To investigate tumor-associated protein kinase activities, control and tumor samples were fractionated by MonoS chromatography and tested for their ability to phosphorylate histone H1. Two major peaks of histone H1 phosphotransferase activity were resolved. The first appeared in the flow through fractions, and occasionally showed enhanced activity in the tumor samples, whilst the second was consistently increased and eluted at approximately 0.4 M NaCl. Western immunoblotting with CDK1 and PSTAIRE antibodies confirmed the co-elution of CDK1 and CDK2 with the second peak. Next, the phosphotransferase activities (following specific immunoprecipitation) and protein levels of CDK1, 2, 4, and 6 were determined in human colon cancer samples and their respective controls. CDK4 activity was elevated in only 3 of 7 tumor samples (range 40-160%) relative to control samples from the same patients, whereas a significant increase in CDK6 activity was observed in the same group (p < 0.05). This contrasted sharply with the universal activations of CDK1 (up to 18-fold, p < 0.01, n = 12) and CDK2 (up to 17-fold, p < 0.05) in the same groups. CONCLUSIONS: CDK1 especially, and to a lesser extent CDK2 and CDK6 demonstrate the most consistent biochemical activation in human colon cancer and may represent targets for pharmacological intervention. Cellular proliferation as gauged by MIB1 was not directly correlated with the amplitude of activation.

Antigens, Nuclear↗
PubMedDate not supplied

[Total quality: priority objective to improve the services of health facilities].

The increasing attention turned to the "total quality" inside health services is pointed out in the article. The development of this theme started in the United States and subsequently reached Europe. In Italy only since a few years we are noticing initiatives aiming both to the improvement of health services quality and to the relationship with clients. The main elements of the total quality management are pointed out: they are addressed to the satisfaction of clients expectations in an environment involving the whole health personnel towards the continuous quality improvement.

Europe↗