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M Di Giulio

Publications and source records attributed to M Di Giulio.

41 records · Page 3Linked to original sources
PubMed1987

Absorbent Markov chains as a model for the study of the evolution of proteins.

The formalism of absorbent Markov chains, previously developed by Kemeny & Snell (1960) is used as a model for the study of the evolution of proteins. Within the limits of statistical analysis used, the amino acid substitution frequencies of McLachlan (1972) are explained by the numerical values derived from the model used. In addition, the amino acid composition of proteins is partially explained and the relative mutability of amino acids receives a new interpretation in the light of the above mentioned stochastic model. The results show that some basic aspect of protein evolution can be predicted by a stochastic model and therefore a significant component of protein evolution is driven by a random element.

Amino Acid Sequence↗
PubMed1982

Molecular parasitism in the Escherichia coli-Bdellovibrio bacteriovorus system: translocation of the matrix protein from the host to the parasite outer membrane.

During the intracellular maturation in Escherichia coli of the parasite Bdellovibrio bacteriovorus the outer membrane, major protein I of E. coli (i.e., the matrix protein) becomes associated with the outer membrane of the emerging parasite cells. The binding properties of this protein with the outer membrane of the host and of the parasite are identical. An analogous phenomenon also occurs during Bdellovibrio parasitism on Klebsiella pneumoniae and on Salmonella typhimurium. Possible roles for this scavenging action of Bdellovibrio, and similar phenomena in other parasitic systems, are discussed.

Bacterial Outer Membrane Proteins↗
PubMedDate not supplied

Intrahepatic metastatic nodules of hepatocellular carcinoma detected at lipiodol-CT: imaging-pathologic correlation.

BACKGROUND: The purpose of this study was to determine whether tiny (< 2 cm) areas of iodized-oil retention diagnosed as intrahepatic metastatic nodules of hepatocellular carcinoma (HCC) at computed tomography (CT) following intraarterial injection of Lipiodol (Lipiodol-CT) correlate with truly cancerous foci on the corresponding sectioned pathologic specimens. METHODS: Thirty-two consecutive patients with biopsy-proven HCC (26 men and six women, aged 41-72 years) underwent prospective evaluation with Lipiodol-CT before undergoing surgery (hepatic resection, 30 patients; liver transplantation, two patients). Imaging findings were correlated with intraoperative and pathologic findings. RESULTS: Twenty-one areas of retained Lipiodol (0.5-1.6 cm in diameter, mean +/- SD: 0.9 +/- 0.3 cm) had features consistent with intrahepatic metastatic nodules of HCC on Lipiodol-CT scans. Nineteen of the 21 areas correlated with tumor deposits at pathologic examination of the surgical specimens, whereas two of 21 were due to abnormal retention of iodized oil within noncancerous liver parenchyma. The positive predictive value of findings at Lipiodol-CT for the diagnosis of intrahepatic metastatic nodule of HCC was 90.5%. CONCLUSIONS: Findings at Lipiodol-CT enable a reliable diagnosis of intrahepatic metastatic nodules of HCC.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

On the relationships between the genetic code coevolution hypothesis and the physicochemical hypothesis.

This paper analyzes the relationships between the genetic code coevolution hypothesis and the physicochemical hypothesis by means of a comparative study of the precursor-product amino acid pairs on which the former hypothesis is based. Even if the coevolution between the biosynthetic relationships of amino acids and the organization of the genetic code is not questioned in this paper, the results and the arguments used lead us to believe that the selective pressures considered essential by the physicochemical postulates, played a more active role than that of the precursor-product relationships in defining the allocation of these amino acids in the genetic code. It is furthermore pointed out that the two evolutionary hypothesis might be aspects of the same selective pressure, and thus difficult to differentiate.

Amino Acids↗