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Biomedical subjects

M Di Carlo

Publications and source records attributed to M Di Carlo.

33 records · Page 2Linked to original sources

Spatial distribution of two maternal messengers in Paracentrotus lividus during oogenesis and embryogenesis.

We demonstrated that two mRNAs that are synthesized during the vitellogenic period of oogenesis and that code for cell surface proteins are asymmetrically distributed in the unfertilized egg of Paracentrotus lividus. At fertilization, these RNAs rapidly localize in the cortical zone at the animal pole of the egg. They are then detected in the mesomeres and the macromeres, but not in the micromeres, and thereafter are found in the ectoderm but not in the vegetal plate, mesenchyme cells, or early intestine. They disappear in late gastrula. The proteins synthesized by these mRNAs show the same territorial location during the period examined here, which included the unfertilized egg and the 16-blastomere stage. These conclusions were reached on the basis of in situ hybridization and immunostaining experiments, as well as Northern and Western blot analyses of isolated blastomeres. The possible significance of this asymmetric distribution of these two mRNAs and proteins in the establishment of the animal/vegetal axis is discussed.

Animals↗

Cloning and sequencing of a cell surface protein-encoding gene conserved in sea urchin species.

We report the nucleotide sequence of a fragment of DNA derived from a sea urchin genomic clone containing the cell surface Bep4 (butanol-extracted protein 4)-encoding gene. The structural gene is interrupted by four introns and the promoter region contains TATA and CAAT consensus motifs. The transcription start point (tsp) was also determined. Remarkable homologies, between Bep4 and other proteins known to be involved in cell interactions, were observed regarding two potential Ca(2+)-binding sites and the corresponding DNA consensus sequences. We also report the conservation of the bep4 gene and its corresponding Bep4 protein between various sea urchin species by way of Southern and Western blotting.

Amino Acid Sequence↗

Identification of a protein encoded by a mouse simple repeated sequence.

In order to study the possibility that a mouse repeated 'simple sequence', containing an ORF, could encode a protein, we inserted a fragment of a cDNA clone into the expression vector pEX31C. The fragment containing the short sequence 'CAGAGAGG' was expressed as MS2 polymerase fusion protein in Escherichia coli. This fusion protein (H5fp) was injected subcutaneously into rabbit and the corresponding polyclonal antibodies generated. Western blot analysis of proteins extracted from different mouse tissues established that anti H5fp antibodies recognized, in vivo, an antigen of 28 KDa. Immunolocalization with anti H5fp antibodies showed the presence of the related antigen in the cytoplasm of the examined sections. An hypothetical secondary structure for the protein was predicted by the Chou and Fasman method.

Amino Acid Sequence↗

Characterization of bep1 and bep4 antigens involved in cell interactions during Paracentrotus lividus development.

We have identified and partially characterised two antigens, extracted with 3% butanol, from Paracentrotus lividus embryos dissociated at the blastula stage, and encoded by the cDNA clones previously described as bep1 and bep4 (bep-butanol extracted proteins). The cDNA fragments containing the specific central portions of bep1 and bep4 were expressed as MS2 polymerase fusion proteins in Escherichia coli. These two fusion proteins, called 1C1 (bep1) and 4A1 (bep4), were injected subcutaneously into rabbits and the corresponding polyclonal antibodies generated. Western blot analysis of proteins, extracted with 3% butanol, from sea urchin embryos at the blastula stage (b.e.p.), established that both antibodies recognize two 33 KDa proteins. Reducing and non-reducing electrophoretic conditions show that both antibodies against bep1 and bep4 related proteins react also with a protein band of a molecular weight 66 KDa, indicating that these two antigens probably exist as dimers. Immunolocalization with anti 1C1 and 4A1 antibodies shows the presence of the related antigens also on the cell surface. Fab fragments of the polyclonal antibodies against 1C1 and 4A1 inhibited reaggregation of sea urchin embryonic cells, dissociated from blastula stage embryos. This prevention of reaggregation indicates that these proteins probably play a role in cell interaction during sea urchin embryonic development.

Animals↗

A mouse repeat sequence conserved in eukaryotic genomes.

To study the biological role of simple repetitive DNA sequences, we analysed a clone isolated from a mouse macrophage cDNA library called T2. This clone contains two simple repetitive sequences: a new sequence, 'CAGAGAGG', and a sequence previously described, 'GATA'. By sequencing analysis, an open reading frame, coding for 225 amino acids, is detected in the T2 clone. The new simple sequence is present thousands of time in the mouse genome, associated or not with the sequence 'GATA'. The sequence 'CAGAGAGG' is transcribed in messenger RNAs. Northern blots of RNAs extracted from adult tissues and from differentiated or non differentiated cell lines show a large number of transcripts that quantitatively decrease when in vitro differentiation occurs. Moreover, Southern blots of DNA extracted from different organisms, hybridize with a fragment containing only the 'CAGAGAGG' sequence, demonstrating that this sequence is represented in the genome of phylogenetically distant eukaryotes, and is highly conserved during eukaryotic evolution.

Amino Acid Sequence↗

Sequence of a sea urchin hsp70 gene and its 5' flanking region.

We report the nucleotide sequence of a 4470-bp fragment derived from a sea urchin genomic clone containing part of a heat-shock protein 70 (Hsp70)-encoding gene. This fragment, named hsp70 gene II, contains 1271 bp of the flanking region and 3299 bp of structural gene sequence interrupted by five introns and encoding the N-terminal 371 amino acids (aa) of the protein. The 5' flanking region contains a putative TATA element, two CCAAT boxes, four heat-shock consensus sequence elements (hse) and one consensus sequence for binding of Sp1. Remarkable homologies were observed for deduced aa sequence and intron-exon organization between hsp70 gene II and rat hsc73 gene.

Amino Acid Sequence↗

Analysis of the sequence and expression during sea urchin development of two members of a multigenic family, coding for butanol-extractable proteins.

Two cDNA clones related to Paracentrotus lividus butanol-extracted proteins, presumably belonging to cell surface proteins, were isolated by a lambda gt11 expression library of ovary poly A+ RNA. These clones, called bep1 and bep4, of 1,110 and 1,071 bp, respectively, belong to a multigene family. By sequencing analysis, a special structural organization in the coding region is detected. A single copy region is inserted between two regions different from each other but similar in the two clones, which constitute two perfectly preserved domains in the genome and are not always present together in the various members of this gene family. The bep1 and bep4 clones derive from two single genes that are polymorphic in the sea urchin genome. Expression of these clones was studied by Northern blot analysis. Both bep1 and bep4 are transcribed during oogenesis into mRNAs of 1.4 kb, which are stored in eggs and utilized during early embryogenesis. None of these RNAs is, in fact, detectable after the gastrula stage. Moreover, the transcripts of three other members of the family are present in eggs and at the 32 cell stage, but they are also synthesized in the early developmental stages.

Amino Acid Sequence↗

Clinicopathological features in patients with isolated C3 mesangial proliferative glomerulonephritis.

The clinicopathological picture of 'isolated C3 mesangial nephritis' was studied in our case records. Focal and segmental or generalised deposits of C3 in the mesangium were found in 12 of 157 (7.6%) patients with primary glomerulonephritis. The clinical picture, similar to Berger's disease, was characterised by episodes of gross haematuria and/or persistent or recurrent microhaematuria and/or proteinuria. Arterial hypertension and mild renal failure were observed in one case. Light-microscopy showed minor glomerular changes such as focal and segmental increase of mesangial matrix and mesangial hyperplasia. During the short-term follow-up (median 25.5 months) no deterioration of renal function was observed. The clinical course and short-term prognosis suggest that this form of glomerulonephritis is benign.

Adolescent↗

Structure and evolution of the 7SL RNA component of the signal recognition particle.

We have cloned and characterized cDNA copies of larval and adult Drosophila 7SL RNA. The Drosophila 7SL sequence shares 66.3% homology with that of human 7SL RNA. The homology is not evenly distributed along the sequence, but is concentrated in blocks in the central part of the molecule. We have analysed the secondary structure of Drosophila and human 7SL RNA free in solution by digestion with single and double strand specific nucleases. Similar experiments with the 7SL RNA bound to proteins within the signal recognition particle show essentially the same digestion pattern. A model of the secondary structure common to Drosophila and human 7SL RNA is presented.

Animals↗

Synthesis of heat shock proteins in dissociated sea urchin embryonic cells.

Embryos dissociated into cells retain the stage-specific response to heat shock. The dissociated cells, irrespectively of whether they are reaggregated or not, undergo the developmental changes in their ability to respond to heat shock, at the same time as the entire embryos. The conclusion of the present experiments is that sea urchin embryonic cells become responsive to heat shock and produce heat shock proteins even in the absence of cell interactions.

Animals↗

Heat-shock proteins in sea urchin embryos. Transcriptional and posttranscriptional regulation.

The production of heat-shock proteins in sea urchin embryos is accompanied by the appearance at the polysomal level of their relative mRNAs, as shown by their translation in a cell-free system; thus suggesting that the regulation of their production occurs at a transcriptional level. The mechanism for the inhibition of the bulk protein synthesis and for its reversal on the other hand should be looked for at a posttranscriptional level, since both these phenomena occur also in the presence of actinomycin D. The heat-shock proteins produced as early as at the mesenchyme blastula stage persist within the embryo at least till the pluteus stage.

Animals↗

[Clodronate and radiotherapy for the treatment of osteolysis caused by metastasis of breast carcinoma and non-small cell lung carcinoma. A retrospective study].

We have retrospectively examined 94 evaluable patients with metastatic osteolysis from breast cancer (BC) and non-small cell lung (NSCLC) cancer, who received RT from Nov. 88 to Nov. 89.27 (15 BC and 12 NSCLC) were in treatment with Clodronate for at least 3 days from the beginning of RT; of the remaining 67 treated with RT alone, 31 had NSCLC and 36 BC. We have evaluated: increase in pain (IP) occurring on the first days of RT, percentages of complete pain relief (CPR) at the end of RT and 4-6 weeks after. A decreased occurrence of IP was observed more in NSCLC patients receiving RT + Clodronate compared to those treated with RT alone (33.3% vs 41.9%). Both at the end of RT and 4-6 weeks after, we registered a significant difference in the percentages of CPR in the RT + Clodronate group (40.7 vs 20.9 and 70.3% vs 53.7%). We believe the points of interest focused in this paper-greater precision in centering and defining the target volume, decreased occurrence of IP during the first days of RT, increase in percentage of CPR--need a prospective confirmation.

Bone Neoplasms↗

[Pelvic carcinomatous neuropathy: clinical, radiologic, therapeutic implications].

Carcinomatous involvement of the pelvic nerves (Pelvic Carcinomatous Neuropathy-PCN-) causes disabling sensorial and motor disturbances of the lower extremities. Recurrent rectal carcinomas are the most common cause of PCN because surgical obliteration of the perirectal fascia. In 31 cases of PCN Authors describe the types of the neoplasm and the sites of involvement of the pelvic nerves evaluating clinical syndromes and Computed Tomography. The results of radiotherapy (doses between 36-56 Gy) in 14 cases of PCN by recurrent rectal cancer are also reported. Although the survival of such patients is poor, radiotherapy has obtained a good palliative result in 50% of them. Personalization of radiation treatment planning is advisable in order to avoid acute side-effects.

Humans↗