Endothelial leukocyte adhesion molecule-1-dependent adhesion of colon carcinoma cells to vascular endothelium is inhibited by an antibody to Lewis fucosylated type I carbohydrate chain.

Endothelial leukocyte adhesion molecule-1 (ELAM-1) has been determined to be the mediator of adhesion of colon carcinoma cells to interleukin-1 (IL-1)-activated endothelial cells. To identify ELAM-1 ligand in colon carcinoma cells, we have screened a series of 11 monoclonal antibodies directed to these cells and found that only one MBr8 was able to inhibit the IL-1-induced increment in adhesion of HT29 and of SW948 colon carcinoma lines to endothelial cells. In contrast, MBr8 did not bind to polymorphonuclear cells, monocytes, and lymphocytes and did not inhibit polymorphonuclear adhesion to IL-1-activated endothelial cells. As expected, an ELAM-1 monoclonal antibody strongly inhibited IL-1 induced increment of adhesion of HT29, SW948, and polymorphonuclear cells. As negative control, MG63 osteosarcoma cells were used. These cells adhere more efficiently to IL-1 activated endothelial cells but MBr8 and ELAM-1 monoclonal antibodies did not affect their adhesion. The effect of MBr8 was also tested in an experimental system in vivo. As described previously, radiolabeled HT29 cell retention in the lung of nude mice was increased in animals given IL-1. MBr8 administration to nude mice or pretreatment of tumor cells with it inhibited this effect. These data suggest that cell adhesion to ELAM-1 might be mediated by different, cell type specific, sugar ligands.     

Characterization of the epitope recognized by a mAb that reacts differentially with murine suppressor T cells

Although reliable antibodies are available that distinguishhuman suppressor T (T_s) cells from CTL and other T cells, feware available for murine T_s cells. We have developed a mAb (984D4.6.5)that, in the presence of complement, depletes alloantigen-specificT_s cells but not CTL. This antibody recognizes activated TT_scells but not their precursors. In these studies, flow cytometricanalysis demonstrates that 984D4.6.5 reacts with several T_scell hybridomas, cloned T_h cell lines and WEHI-3 (a myelomonocytictumor cell line). Reactivity was not detected with BW5147, T_hcell hybridomas, cloned T_h cells, CTL lines and hybridomas,B cell lines, thymocytes, splenocytes, bone marrow cells nora variety of tumor cells. Among 984D4.6.5 positive lines, expressionis heterogeneous and the number of cells expressing high levelsof the epitope is increased when the hybridomas are maintainedat a relatively high cell density. Neuriminidase and pronasedeplete the epitope recognized by mAb 984D4.6.5. Protein synthesisand glycosylation inhibitors also reduce expression of thisepitope. These observations suggest that the epitope recognizedby 984D4.6.5 is a carbohydrate linked to a polypeptide. Thisantibody was tested by ELISA for binding to a large panel ofcarbohydrates and glycollpids coupled to BSA. The only one thatbound 984D4.6.5 was LS tetrasaccharide c (NeuNAc2-6Galpß1-4GIcNAcß1-3GaIß1-4Glc),an O-linked carbohydrate. Comparative analysis shows that boththe sequence and the linkage of these sugars are essential tothe reactivity with the 984D4.6.5 antibody. This epitope isexpressed by a glycoprotein of-200 kDa, as shown by Westernblots. The identity of this glycoprotein remains to be determined,but indirect evidence suggests that it is not CD45.     

Potential of Gene Therapy in Bone Marrow Transplantation

Gene therapy, initiated as a treatment for inherited disorders such as adenosine deaminase deficiency, is now a promising therapeutic strategy for malignancies and other acquired diseases. In particular, in the field of bone marrow transplantation (BMT) for haematological malignancies, the gene transfer of the suicide gene HSV-TK into donor lymphocytes allows control of the severe complication graft-versus-host disease (GvHD). The transfer of the HSV-TK suicide gene confers selective sensitivity to the drug ganciclovir, allowing in vivo elimination of the donor T-cells if severe GvHD occurs. In Italy, the first pilot study on delayed infusion of genetically engineered donor lymphocytes after T-depleted allogeneic BMT documented efficacy of engineered donor lymphocytes in terms of anti-tumour activity and efficiency of the suicide system. GvHD developed in 3 out of 8 patients and was successfully treated by ganciclovir administration.     

Modulation of feeding-induced activation of mesolimbic dopamine transmission by appetitive stimuli and its relation to motivational state

We have previously shown in non-deprived rats that feeding of an unfamiliar palatable food (Fonzies(R)) phasically stimulates in vivo dopamine (DA) transmission in the medial nucleus accumbens (NAc) and this effect undergoes habituation after a previous (24 h) Fonzies meal (Bassareo & Di Chiara 1997, J. Neurosci., 17, 851-861). The present study shows that an unfamiliar food (Kinder(R)) with a taste and composition (milk chocolate) different from that of Fonzies, also induces a release of DA in the NAc subjected to one-trial habituation. Habituation was taste specific as no cross-habituation was observed between Fonzies and Kinder. In undeprived rats, a 40-min exposure to an intrinsic appetitive stimulus (food smell arising from a Fonzies-filled plastic box) also prevented the increase in dialysate DA associated with Fonzies feeding, and this effect was partially reversed by food deprivation. Food deprivation also prevented habituation of Fonzies-induced increase of dialysate DA in the NAc. Predictive association of an empty plastic box to Fonzies feeding resulted in the acquisition of appetitive properties by the box and in facilitation (rather than inhibition) of the phasic responsiveness of DA transmission to Fonzies feeding. A 10-min pre-exposure to appetitive olfactory stimuli intrinsic to Fonzies still prevented, like a 40-min pre-exposure, the NAc DA response to Fonzies feeding; however, a 5-min pre-exposure to these appetitive stimuli did not prevent the DA response in the NAc. These results show that the phasic responsiveness of NAc DA transmission to an unfamiliar palatable food is under strong modulatory control by primary (consummatory) and secondary (appetitive) stimuli, and that the sign and extent of this control depends on the nature of the appetitive stimulus, delay of reward and motivational state (deprivation).     

Extension of necrosis in the acute phase of myocardial infarct. Clinical picture and prognosis

In a consecutive series of 297 patients prospectively evaluated at the time of admission for an acute myocardial infarction, the extension of necrosis was found to occur in 16,4% of the cases. The electrocardiographic site of extension was the same as during the initial episode in over 75% of cases suggesting the possibility of a similar pathogenetic mechanism and the involvement of the same coronary district. Patients in Killip class I were respectively 61% and 45% before and after the extension, in class II 33% and 14%, in class III 6% and 14%, in class IV 0 and 27% (p less than 0,001). In-hospital mortality was 16,1% without and 38,8% with extension (p less than 0,001). The peak level of CPK-MB was an average of 110 +/- 45 U/1 before and 96 +/- 34 after the extension (p = N.S.). It was not possible to recognize the patients at risk of extension according to the traditional clinical parameters (age, sex, site of necrosis, transmural involvement, residual angina, Norris index and Killip class before the extension). It is concluded that the protection of the myocardium at risk is of primary importance in the setting of acute myocardial infarction, regardless of the possibility of saving areas already compromised at the time of admission or the hypothetical "border zone".     

The pediatric emergency department: assessment of clinical activity and interaction with local health authorities]

A perspective study was carried out at the Emergency Department of the Gaslini Institute on a sample of the children admitted from May to September 1990. The study aimed to describe types and modalities of admission. "G. Gaslini" Institute is a multidisciplinary children's hospital: 45% of patients admitted in the hospital come from the southern regions of Italy, while the admission at the Emergency Department were local in 82%. Among all children considered, 2080 (71.9% were admitted on request of their parents, who did not ask previously any physician; of those cases, 356 (17%) were hospitalized, 474 (25%) were either examined by specialist or treated and then discharged. In the remaining cases, no intervention was necessary. As a consequence, 58% of children were admitted without any clinically plausible reason. Parents' anxiety clearly played an important role in most cases. 840 children were addressed to the Emergency Department by a physician, 652 (22.3%) by the doctor in charge, 213 (32.7%) of which were sent back home by the doctor on duty, who did not think it necessary any treatment. Of the 120 (4.1%) children sent by different Emergency Departments, 95 (79.1%) were hospitalized. The reason why physicians addressed quite a large number of children to the Emergency Department, when they didn't need any intervention remain nucleo. Their diagnosis, in fact, agreed with those of the doctor on duty in 83% of cases. In conclusion, it is difficult to imagine a diagnostic or therapeutic problem which needs specific structures. Cooperative programs with physicians working in our region will be carried out in order to control, where possible, admission to Emergency Departments.     

The activities of a pediatric emergency department. The emergency problems]

The authors reviewed records of admission at the Fist Ais-Emergency Service of "G. Gaslini" Children's Hospital, data referring both to in and outpatients. First of all we took into account epidemiological data analysing occurrence and types of diseases; at the same time a demographic study, which aimed to show a decrease in the child population in Genova, was performed. Secondly we compared these data with the real number of admitted patients: collected data showed that this service has been used excessively.     

Surgery for colorectal cancer guided by radiodetecting probe. Clinical evaluation using monoclonal antibody B72.3.

Radioactive antibodies that react with tumour-associated antigens to "tag" antigen-positive tumour cell deposits were given to 20 patients with primary or recurrent colorectal cancer. The tumour associated antigen TAG 72-specific monoclonal antibody B72.3 labelled with 125-Iodine was used, and the radioactivity in the tumour was sought during operation with a hand-held gamma detecting probe. Tumour was detected by the probe in 7 of 15 patients with primary cancer, with a mean tumour: normal tissue ratio of 3.9, and in 4 of 5 patients with recurrent disease, with a mean tumour: normal tissue ratio of 2.0. Immunohistochemical analysis of surgical specimens confirmed the results of the intraoperative detection. The incidence of TAG 72-positive tumours (11/20, 55%), detected by immunohistochemistry, was lower than the 80% in the other series, possibly because of sampling errors or because the cases studied were uncomplicated with small primary tumours. Results obtained with the probe were instrumental in modifying the operation in two of the four "positive" patients with recurrences, allowing the removal of tumour masses that would otherwise have been overlooked.