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Biomedical subjects

M Di Cola

Publications and source records attributed to M Di Cola.

10 recordsLinked to original sources

Possible role for Ca(2+) calmodulin-dependent protein kinase II as an effector of the fertilization Ca(2+) signal in mouse oocyte activation.

The present study shows that Ca(2+) calmodulin-dependent protein kinase II (CaM kinase II) is physiologically activated in fertilized mouse oocytes and is involved in the Ca(2+) response pathways that link the fertilization Ca(2+) signal to meiosis resumption and cortical granule (CG) exocytosis. After 10 min of insemination, CaM kinase II activity increased transiently, then peaked at 1 h and remained elevated 30 min later when most of the oocytes had completed the emission of the second polar body. In contrast, in ethanol-activated oocytes the early transient activation of CaM kinase II in response to a monotonic Ca(2+) rise was not followed by any subsequent increase. Inhibition of CaM kinase II by 20 micromol/l myristoylated-AIP (autocamtide-2-related inhibitory peptide) negatively affected MPF (maturing promoting factor) inactivation, cell cycle resumption and CG exocytosis in both fertilized and ethanol-activated oocytes. These results indicate that the activation of CaM kinase II in mouse oocytes is differently modulated by a monotonic or repetitive Ca(2+) rise and that it is essential for triggering regular oocyte activation.

Animals↗

Cytogenetic findings in terminal large cell transformation in a case of Sézary syndrome.

A long-lasting case of Sézary syndrome, whose chromosomal pattern had been repeatedly investigated during a follow-up period of several years, was studied in the terminal transforming phase, which took place more than 5 years after the initial diagnosis. To the best of the authors' knowledge, this appears to be the first instance of cytogenetic studies carried out in a large cell transformation of cutaneous T-cell lymphoma. The results clearly indicate that the atypical large cells seen in the transforming phase were clonally derived from the pre-existing cerebriform cells. Newly detected relevant cytogenetic findings were: a) drop of tumor cell ploidy from hypotetraploid to hypotriploid, with striking chromosomal imbalance; b) additional structural aberrations of chromosomes 2 and 7, which had been already preferentially involved in the earlier phases, and involvement of the previously unaffected chromosomes 1, 3, and X; and c) presence in 100% of the abnormal metaphases of a large HSR on the long arm of chromosome 17.

Aged↗

Paracentric inversion of chromosome 15(q15q24): description of three families.

Three unrelated families with paracentric inversion of chromosome 15(q15q24) are reported. An additional pericentric inversion of chromosome 9 with breakpoints in p11.2q13 was also observed in one of the three families. Reproductive problems, such as stillbirths, spontaneous abortions and two live-born children with multiple abnormalities, were present.

Adult↗

Nonrandom chromosome changes in multiple sclerosis.

In order to study the role of genetic factors in multiple sclerosis, cytogenetic analysis was performed on 48 patients with the clinically defined disease. We found a high incidence of subjects (50%) with abnormal chromosomes, showing premature centromere division of the X chromosome and structural aberrations, translocations, or deletions that could suggest preferential breakpoints. Correlation between clinical and cytogenetic data showed that cytogenetic abnormalities were more common in patients with high frequency of relapse or with a progressive form of the disease.

Adolescent↗

Cytogenetic follow-up in a case of Sézary syndrome.

A cytogenetic follow-up study was performed for a 3-year period on a 70-year-old patient with Sézary syndrome (SS). The results showed formation of hypotetraploid cell clones with 60 to 89 chromosomes and 19 markers, some of which appeared during the period of study and stabilized thereafter. The incidence of these clonal cells increased from 29% to 85% during the follow-up study. The results confirm the presence of hypotetraploid cell clones, especially in the more advanced stages of SS. Moreover, some marker chromosomes in our patient (M2 and M3), derived from chromosome 2, were similar to those observed in SS by other investigators. According to our data and to those in the literature, SS appears to involve preferentially chromosomal regions 2p12-13, 2p21-22, 2q37, 17p13, 13q1, 9q11, 10p13, 14q11, 14q32, 7p1 and, to a lesser extent, 5q and 6q.

Aged↗

Possible genotoxicity of melanin synthesis intermediates: tyrosinase reaction products interact with DNA in vitro.

The actual cellular target of the cytotoxic intermediates of melanin synthesis is not yet known. In the present paper it is shown that eukaryotic DNA binds in vitro to soluble reaction products of tyrosinase (EC 1.14.18.1) and is physically modified, as ascertained by the following criteria: (a) buoyant density in cesium chloride density gradients; (b) polyacrylamide gel electrophoresis; (c) deoxyribonuclease (EC 3.1.4.5) test; (d) electron microscopy. The results reported here support the view that DNA itself may be a target for the cytotoxic intermediates of melanin synthesis.

Animals↗

Some properties of Bufo bufo tyrosinase during development.

Tyrosinase expression during Bufo bufo development has been investigated. Until stage 19, only 1 electrophoretic band is detectable, but at a later stage (25) 3 bands appear. The Km for L-3,4-dihydroxyphenylalanine (L-dopa) was also determined.

Animals↗