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Biomedical subjects

C Romeo

Publications and source records attributed to C Romeo.

At least 55 records · Page 3Linked to original sources
PubMed1994

Association of Raf with the CD3 delta and gamma chains of the T cell receptor-CD3 complex.

Protein kinases and phosphatases play an important role in signal transduction. In the T cell, activation via the T cell receptor-CD3 complex results in rapid tyrosine phosphorylation of proteins, as well as subsequent increases in serine/threonine phosphorylation. The Raf serine/threonine kinase has been implicated in many receptor signaling pathways, including those of platelet-derived growth factor, epidermal growth factor, insulin, and interleukin-2 receptors. We show here that Raf is associated with the T cell receptor-CD3 complex in unstimulated murine T cells. Using a COS cell expression system, we show that a hypophosphorylated form of Raf specifically associates with the CD3 gamma and delta chains but not with the CD3 epsilon or zeta chains. These results suggest that Raf mediates signal transduction from the gamma and delta chains of the T cell receptor-CD3 complex, analogous to the role played by ZAP-70 in signal transduction mediated by the zeta chain.

Animals↗
PubMed1994

[Fetal cystic neuroblastoma].

Neuroblastoma is the most common malignant solid tumor in infants less than 1 year old. A case of adrenal cystic neuroblastoma detected by ultrasound in the 37 th week of pregnancy, is reported. The sonographic features of fetal neuroblastoma range from solid to cystic or complex lesions. Early detection of the tumor by prenatal ultrasound permits prompt neonatal treatment and a better outcome.

Adrenal Gland Neoplasms↗
PubMed1993

T cell activation by clustered tyrosine kinases.

Many cellular recognition events in the immune system are initiated by aggregation of cell surface receptors that lack intrinsic protein-tyrosine kinase activity. Receptor-associated kinases related to the src protooncogene product have been found to be essential for cellular activation and may interact with the cytoplasmic domains of the antigen receptor chains. We show here that anti-CD16 antibody-mediated clustering of chimeric transmembrane proteins bearing a CD16 extracellular domain and a Src family kinase intracellular domain is not sufficient to initiate a cellular activation signal in T cells, whereas clustering of similar chimeras bearing Syk or ZAP-70 kinase sequences triggers calcium mobilization. Aggregation of the Syk chimera alone, or coaggregation of chimeras bearing Fyn and ZAP-70 kinases, suffices to initiate cytolytic effector function. The pattern of tyrosine phosphorylation induced by clustering of the Syk chimera is similar to the pattern induced by aggregation of T cell receptor.

Amino Acid Sequence↗
PubMed1992

Sequence requirements for induction of cytolysis by the T cell antigen/Fc receptor zeta chain.

The zeta chain of the T cell antigen receptor is a dimeric transmembrane protein with a very short extracellular domain and an extended cytoplasmic tail that triggers T cell effector function when aggregated by extracellular stimuli. We have reduced the active site of zeta to an 18 residue motif that can be appended to the intracellular domain of other transmembrane proteins to endow them with receptor-like activity. The compact size of the motif appears to eliminate zeta mechanisms based on enzymatic activity and suggests that one or at most a few cellular proteins interact with the zeta intracellular domain to initiate signal transduction. Analysis of individual amino acids within the 18 residue element reveals two phylogenetically conserved tyrosines that are absolutely required for activity and other residues that are less essential but contribute to the efficacy of receptor-directed cytolysis.

Amino Acid Sequence↗
PubMed1992

Lineage-independent activation of immune system effector function by myeloid Fc receptors.

An emerging theme in immunology finds receptors which initiate cellular effector programs forming multichain complexes in which the ligand recognition elements associate with one or more 'trigger molecules' whose aggregation initiates a signal transduction cascade. The sequence motifs constituting the active sites of these trigger molecules are found in the T cell and B cell antigen receptors, and some Fc receptors, and appear to be central to effector function activation. For example, of the many molecules that mimic or potentiate the action of the T cell antigen receptor (TCR), none have yet been found to initiate effector programs autonomously in cells lacking TCR. We have devised two strategies to study activation mediated by myeloid Fc receptors, which appear not to associate with trigger molecules: the use of primary human cytolytic T cells as surrogate effector cells for genetically delivered receptors, and the use of vaccinia virus vectors to introduce genetically modified receptors into primary human monocytes. Using these approaches, we have found that the cytoplasmic domains of two Fc receptors show comparable function to equivalent domains of the trigger molecule family, but are not homologous to members of that family.

Amino Acid Sequence↗
PubMed1992

[The adenosine test in association with 99m-technetium sestamibi tomoscintigraphy in the diagnosis of coronary pathology].

BACKGROUND: The exogenous adenosine is able to provoke a coronary vasodilation, which is the same as the one provoked by the papaverine and greater than the one provoked by the dipyridamole. We report our experience in using exogenous adenosine in association with technetium-99m-sestamibi tomoscintigraphy for a diagnostic test on the coronary artery disease (CAD). METHODS: We considered 22 patients (18 male and 4 female, mean age 57 years) affected by angiographically demonstrated coronary artery disease (stenoses > or = 50%). Adenosine was infused at a dosage of 0.070 mg/kg/min for 3 minutes and, if well tolerated, the dosage was increased to 0.140 mg/kg/min; in the third minute of the major dosage the radioisotope was injected. The myocardial perfusion imaging at rest was evaluated on the following day. RESULTS: The test was completed on 21 of the 22 patients, and 20 of the latter were subjected to the maximal dosage of the adenosine infusion. Clinically irrelevant adverse effects were observed in 20 cases; only one patient developed a II degree type 1 AV block. Angina occurred in 19 patients. Coronary angiography demonstrated significant stenosis of 35 vessels: the left anterior descending (LAD) in 14 patients, the left circumflex (LCx) in 8 and the right coronary artery (RCA) in 13. In detecting CAD, the test in our study demonstrated a sensitivity of 85% in the LAD disease, of 89% in the LCx disease and of 77% in RCA disease. CONCLUSIONS: The adenosine infusion associated with technetium-99m-sestamibi tomoscintigraphy demonstrated an elevated incidence of adverse effects which are of short duration and clinically irrelevant. The method was shown to be highly sensitive in detecting the CAD.

Adenosine↗
PubMed1991

Cellular immunity to HIV activated by CD4 fused to T cell or Fc receptor polypeptides.

We describe functional simplified T cell and Fc receptor chimeras that are capable of directing CD8+ cytotoxic T lymphocytes (CTLs) to specifically recognize and lyse cells expressing HIV envelope proteins. Target cells bearing HLA-DR molecules are not recognized by CTL armed with the chimeras. The variety of cell types in which the native receptors are active suggests multiple possibilities for antiviral intervention through genetic means.

Amino Acid Sequence↗
PubMed1987

Disorders of the esophageal motor activity in atresia of the esophagus.

Esophageal dysfunction has been reported after successful repair of esophageal atresia but its nature has not been clearly defined. We studied esophageal motility in 20 newborns with esophageal atresia by recording intraluminal pressure of both proximal and distal segments. The investigation was made by pressure monitoring of the upper pouch via the mouth and of the distal segment via the gastrostomy. In all cases we found motility disorders. Two patients (12.5%) showed incomplete relaxation of the upper esophageal sphincter. The resting pressure of the esophageal body in both segments was constantly positive in all cases. Lower esophageal sphincter (LES) function was normal in all but two patients (16.7%) in whom the LES pressure was reduced and one case (8.4%) with incomplete relaxation of the LES. These studies suggest that motility disorders are also present in esophageal atresia before surgery.

Esophageal Atresia↗
PubMed1983

[Sternal cleft. Surgical treatment in the newborn].

The lack of total sternal fusion without other anomalies of the chest wall is extremely rare. We present the case of one 24 h. old female, clinically asymptomatic with complete sternal cleft without other symptoms. She was operated on within the first week of life, a sternal primary suture with costal condrotomy and alternate costal suture were performed. Good thoracic stability was obtained. We agree with other authors about the need for surgical correction during the neonatal period.

Female↗
PubMed1981

[Experiences in the decentralization of the medical welfare activities in the Turin commune].

The welfare and medical activities in the town of Turin which have been decentralized in the quarters or in grouped quarters in order to answer better to the demands of the users, are analysed and explained here. Also a sample of building structure realized in Turin too, as a standard sample of social and medical centre and of basis services on its territory, is presented.

Community Health Services↗
PubMed1980

Antiallergic agents. IV - Substituted 2-benzylidene-3(2H)-benzofuranone-5-carboxylic acids.

A series of substituted 2-benzylidene-3(2H)-benzofuranone-5-carboxylic acids were synthetized and tested for antiallergic activity by the passive cutaneous anaphylactic reaction in the rat. Many compounds display an antiallergic activity comparable to that of disodium chromoglycate when administered parenterally: in addition some derivatives are effective when given by mouth.

Animals↗
PubMedDate not supplied

[McKusick-Kaufman syndrome: diagnostic and therapeutic problems].

Mc Kusick-Kaufman Syndrome (SMK) is an autosomal recessive multiple malformation Syndrome characterized by hydrometrocolpos and polydactyly. This Syndrome is more frequent in females, whose parents are first-degree cousins (frequency 1:8 liveborn). We describe two cases of SMK: a male and a female. Patients were siblings and their parents were first cousins. The first child presented postaxial hexadactily, of the hands and feet, cardiovascular malformation and Arnold-Chiari II malformation. The baby died on the 17th day of life, for neurosurgical complications. Second baby, in which a prenatal ultrasonography showed a large cystic dilatation in the pelvis, presented with urinary hydrometrocolpos associated with persistent urogenital sinus (UGS) and polydactyly. The patient was temporary treated with intermittent vaginal catheterization. At age of 6 months she underwent reconstructive surgery via the anterior sagittal transanorectal approach (ASTRA), previous creation of a colostomy. Thirty-two months of the operation, the patient is continent for stool and urine and the vagina looks normal.

Abnormalities, Multiple↗