Biomedical subjects
Publications and source records attributed to T Soldati.
Two cases of lipomatosis of the ileocaecal valve, causing intestinal obstruction are reported. Surgery was performed on an emergency basis. A careful assessment of clinical and radiological findings is important, in order to distinguish such as a disease from caecal carcinoma. In fact this is a benign disease, for which conservative surgery is indicated.
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The isoprotein-specific intracompartmental sorting of the three essential myosin light chains (LCs), the skeletal muscle LC-1f and LC-3f and the nonmuscle LC-3nm, was investigated. Epitope tagging was used to monitor the intracellular localization to different cytoskeletal structures of the exogenously introduced constructs in adult rat cardiomyocytes (ARCs), which exhibit both stress fibers and regenerating myofibrils. LC-1f and LC-3f bind almost exclusively to the sarcomeric myosin heavy chain (MHC) with high affinity, while the LC-3nm interacts with stress fibers and sarcomeres equally well. Sorting appears to be directed by a hierarchical order of different affinities. Domain mapping by deletion and by construction of a LC-1f/3nm chimera suggests that the LCs are composed of three functionally distinct domains: a basal MHC binding site in the C-terminus; the central part, modulating the preferential interaction with MHC isoforms; and the isoprotein-specific N-terminus of the essential LC, which is probably not involved in the sorting process.
In addition to the two monomer subunits of chicken brain-type creatine kinase (B-CK, EC, 2.7.3.2), termed Bb (basic) and Ba (acidic), another subspecies called Bb* was identified by chromatofocussing in the presence of 8 M urea (Quest et al., ). The latter low abundance protein species, isolated from tissue extracts, comigrated on 2D-gels with three minor species (Bb1-3), initially identified in immunoprecipitated, [35S]methionine labeled in vitro translation products of cDNA coding for the basic monomer Bb. During in vitro translation experiments in the presence of [32P]-gamma-ATP, Bb1-3 were labeled while phosphatase treatment eliminated these minor species. It is concluded that Bb* is identical to Bb1-3 and represents phosphorylated derivatives of Bb. B-CK dimer populations from different tissues were separated by ion-exchange chromatography and the Km values of the resulting fractions were determined under phospho-creatine (CP)-limiting conditions. In fractions containing only Bb and Bb* two kinetically different enzyme species were detected (Km values for CP = 1.6 mM and 0.8 mM), while fractions containing B-CK dimers composed of the major Ba and Bb monomers, but no Bb*, were homogeneous in this respect (Km for CP = 1.6 mM). Phosphorylation of Bb to yield Bb* is concluded to reduce the Km of B-CK dimers for CP by about 50%. This Km shift is within the range of CP concentrations found in tissues expressing the B-CK isoform and may therefore be of physiological relevance.
In the chicken, a high degree of heterogeneity at the protein level has been reported for the creatine kinase-type B (B-CK). Here we show that the two B-CK isoproteins, Ba- and Bb-CK, are encoded by two mRNAs, which are derived from a single copy gene by a stochastic alternative splicing mechanism. The transcription of the single hnRNA is directed by a complex promoter region containing a stretch of sequences which is highly conserved among all the B-CK genes known to date. This stretch encompasses a putative binding site for the TA-rich DNA-binding protein (Hobson, G. M., Mitchell, M. T., Molloy, G. R., and Pearson, M. L. (1988) Nucleic Acids Res. 16, 8925-8944) which is located in the distal part of the promoter region, while the proximal portion containing the TATA-box used in vivo is not conserved between chicken and mammals. The two isoproteins arising from this gene contain distinct N-terminal portions. According to comparative analysis, Bb-CK is the form which is homologous to the mammalian B-CKs, whereas Ba-CK shows some sequence features unique among all other vertebrate cytosolic creatine kinases characterized so far.
A series of 77 cases of rectum carcinoma observed in a six year period, is presented. Sixty-one patients underwent radical operation and 57 of them have been regularly followed up. The incidence of local relapses has been 12.28%, with a majority of perianastomotic forms. It turned out to be proportional to the aboral distance and to primitive neoplasm staging, but not to histologic differentiation degree. Staplers were used and therefore the choice between resection or amputation was determined by the degree of loco-regional infiltration of the neoplasm. The frequency of local relapses turned out not to be related to the type of operation, but the impossibility to the exeresis of perirectal tissues involved by neoplastic process.
In higher eukaryotes three different types of creatine kinases (CK) are expressed: the muscle-specific M-CK, the ubiquitous cytoplasmic B-CKs, and the mitochondrial Mi-CKs. They fulfill multiple tasks in cells with an intensive energy metabolism. Isolated chicken B-CK can be resolved by two-dimensional gel electrophoresis into a major acidic Ba-CK and a major basic Bb-CK protein species which are very likely produced from the unique chicken B-CK gene (Wirz, T., Hossle, J. P., Soldati, T., and Perriard, J.-C. (1989) Experientia (Basel) 45, 32 (abstr.]. However, close inspection of the gels indicates the presence of additional B-CK species. This additional heterogeneity is generated by two distinct post-transcriptional processes. Post-translational phosphorylation was shown to contribute to heterogeneity of both Ba- and Bb-CK isoproteins and appears to modulate their enzymatic activity (A. F. Q. Quest, H. M. Eppenberger, and T. Wallimann, manuscript in preparation). Alternative ribosomal initiation of Bb-CK synthesis at multiple sites was shown to occur in cell free systems as well as in vivo, resulting in proteins differing in the length of their amino termini. Using site-directed mutagenesis to "switch off" each of the first four methionine codons of a full length Bb-CK cDNA, we were able to correlate each protein product with one distinct translational start site. An additional protein species appears to be produced by initiation at a noncanonical start codon. We propose that a leucine codon may be used as a translational start site. Evidence is presented to support the role of these amino-terminal truncated subunits in the regulation of the enzyme.
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23 cases of multiple adenocarcinoma of the large intestine, 14 of them synchronous and 9 metachronous have been analysed. These represent 2.78% of all colon-rectum cancers (825) operated on during the period between 1958 and 1979 in the Surgery Division of the Turin General Hospital directed by Prof. C. Colombo. The classification, anatomo-pathological picture, and surgical treatment are presented, stress being laid in particular on pathogenetic hypotheses of multiple cancer of the large intestine.
A case of papilliferous cystadenocarcinoma of the body and tail of the pancreas marked by unusually slow progresion is presented. It is pointed out that total resection, of the tumour is always necessary. This is also true of cystadenoma, which has a tendency to become malignant.
The Authors describe a case of somatostatinoma in the pancreatic tail, characterized by the absence of a specific symptomatology, with the exception of a slight hyperglycaemia. The patient underwent a surgical operation of pancreatic resection and splenectomy, and now enjoys very good health. They have examined literature from 1977 to 1988, and overall the 30 cases of pancreatic localization, describing the symptomatology, the pathological anatomy, the therapy, and evaluating the malignity degree. Then the Authors could notice that the prognosis of these neoplasms is often fatal, both for the frequent tumor metastatization, and for the difficulties in making an early diagnosis. The therapy is essentially surgical.
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