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G Boccoli

Publications and source records attributed to G Boccoli.

27 records · Page 2Linked to original sources
PubMed1989

Three new class I HLA alleles: structure of mRNAs and alternative mechanisms of processing.

Sixteen HLA class I clones have been isolated from a SV40-transformed human fibroblast line (GM637) cDNA library. The clones, characterized by hybridization to ABC locus-specific probes and sequence analysis, correspond to transcripts from four different class I genes: A2, A10, Cw4, and Cw6 (or Cw7), as implied by cell typing. Only the A2 sequence was known. The nucleotide and deduced amino acid sequence of the new alleles are reported here, and their structural features are discussed. Two independent cDNAs of A2 specificity display an unusual polyadenylation site located 100 bp upstream from the canonical one. Moreover, two cDNAs pertaining to the same C allele display two alternative mechanisms of splicing, which cause either presence or absence in mature transcripts of the transmembrane exon 5 sequence. Transcripts missing this region are predicted to synthesize a nonmembrane-bound, secreted antigen. A soluble protein, specifically reacting with class I-specific HLA antibodies, is found in the supernatant of the GM637 cells. The significance of HLA class I transcripts generated by differential processing is discussed.

Alleles↗
PubMed1989

A device to perform percutaneous cervical pharyngostomy (PCP) for enteral nutrition.

Percutaneous Cervical Pharyngostomy (PCP) is a technique of proven usefulness in Enteral Nutrition and has been used for over 20 years. The procedure has been modified to make it less traumatic and easier to perform. To further improve the technique we have developed a special device, with which it can be performed with minimum trauma under local anaesthesia, and with a smaller number of manoeuvres when compared with previous techniques. In addition, it gives rise to less occupation of the pharyngostomic passage by the nutritional tube (8 Fr.). We have successfully utilised this device on 37 patients, in whom the procedure took no more than 15 minutes. We had no technical complications. Based on our experience, we think that the use of this device makes the application of PCP easier in Enteral Nutrition.

Journal Article↗
PubMed1989

Zinc modulates the mitogenic activation of human peripheral blood lymphocytes.

In the present study we have investigated the effect of Zn salts on the mitogenetic activation of human peripheral blood lymphocytes (PBL). Our results show that Zn2+ enhances the level of DNA synthesis in human T lymphocytes stimulated by a mitogenic lectin, phytohemagglutinin (PHA); this effect seems to be mediated through an enhanced expression of both interleukin-2 (IL-2) and transferrin (Trf) receptors. We have also analyzed the mitogenic effect of Zn2+ alone on PBL, in the absence of other mitogenic stimuli. In this regard we have identified large light density T lymphocytes as the PBL population which is activated to proliferate by Zn2+. Finally, we showed that Zn2+ stimulates natural killer (NK) activity; this effect is apparently not due to a direct action on NK lymphocytes, but is related to endogenous cytokines released by accessory cells which in turn stimulate the cytolytic activity of NK lymphocytes.

Humans↗
PubMed1988

Effect of endogenous and exogenous interferons on the differentiation of human monocyte cell line U937.

The effect of interferons (IFNs) on the differentiation of hematopoietic cells was examined with the human monocyte cell line U937. The differentiation of U937 was induced by hydroxyvitamin D3 and was evaluated through the study of specific markers. The induction of the U937 differentiation was associated with a production of IFN and with a marked increase in (2'5') oligoadenylate synthetase. Addition of anti-IFN-alpha/beta antibodies inhibited the enhancement of (2'5') oligoadenylate synthetase and reduced the inhibitory effect of hydroxyvitamin D3 on cell growth. Nevertheless, neutralization of endogenous IFN excreted during U937 cell maturation did not modify the expression of the differentiation markers examined. Exogenous natural IFN-alpha, IFN-beta, or recombinant (r) IFN-gamma, when added to the culture medium, did not promote a "global" U937 differentiation. Most of the differentiation markers, except for reduction of nitroblue-tetrazolium, were not induced by IFN-alpha or -beta. However, rIFN-gamma was able to induce the appearance of several monocytic membrane markers at an extent comparable or slightly inferior to that elicited by hydroxyvitamin D3. Different effects on the expression of HLA antigens were obtained with these IFNs: IFN-alpha or -beta enhanced mainly class I HLA antigen expression, whereas rIFN-gamma increased selectively the expression of class II HLA DC1 but not HLA DR antigens. In contrast, phytohemagglutinin-leukocyte conditioned medium elicited a marked and selective enhancement of the expression of HLA-DR antigens. This induction of HLA DC1 antigens by rIFN-gamma was not observed in two other leukemic cell lines (HL60 and HEL). The present study shows that IFN-alpha or -beta may participate in the antiproliferative effect occurring during cellular differentiation, while IFN-gamma may be involved in the induction of the expression of specific monocytic markers involved in cellular immunoregulation.

2',5'-Oligoadenylate Synthetase↗
PubMed1986

Percutaneous vs. totally implantable catheters in home parenteral nutrition.

The technique of the implementation of Home Parenteral Nutrition (HPN) is improving continuously so carrying minimum risk of technical complications and supplying maximum comfort for the patient. For example the HPN benefits of the recent availability of Ethil-Vinil-Acetate (EVA) bags that permit the contemporary administration of all nutrients, lipids included, and of infusion pumps which are lighter, safer and more versatile and which have rechargeable batteries. Some new types of completely implantable catheters with a subcutaneous reservoir present a better rationale compared with complications and with patient's compliance in respect of traditional percutaneous catheters used in HPN. We wanted to verify these presuppositions in a retrospective study with a completely implantable catheter, Port-A-Cath (PAC) Pharmacia, with a group of six patients already under HPN for a period of 901 patient-days with a percutaneous catheter. We compared the two methods of treatment after 1114 patient-days with the PAC. Concerning complications, we have three catheter related sepsis (3.3 1000 days) with percutaneous catheter and 1 sepsis (0.9 1000 days) with the PAC. We also had one catheter obstruction in a patient with the PAC implanted in the Inferior Vena Cava. All the patients accepted the new technique and even if they did not have the same motivation, all of them particularly appreciated the possibility of the avoidance of any external device. Our experience leads us to report that the Port-A-Cath system may be useful in long-term parenteral nutrition but other research is needed to confirm its rationale.

Journal Article↗
PubMedDate not supplied

A potential mechanism of local anti-inflammatory action of alpha-melanocyte-stimulating hormone within the brain: modulation of tumor necrosis factor-alpha production by human astrocytic cells.

The proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) occurs in CNS tissue in neurological disorders, infection, and injury. Its excessive production is believed to contribute to local pathology, in which case modulation of TNF-alpha production should promote survival of neural tissue. The neuropeptide alpha-melanocyte stimulating hormone [alpha-MSH (1-13)] inhibits TNF-alpha production in vivo and in vitro, and in this research we tested the capacity of the peptide, and of an anti-inflammatory COOH-terminal tripeptide fragment of it, to inhibit TNF-alpha production induced by bacterial endotoxin in cells of a human glioma line (A-172, anaplastic astrocytoma cells). Both peptides were effective, although the alpha-MSH (1-13) sequence was more potent. Preincubation of the cells with alpha-MSH (1-13) markedly increased its effectiveness. The anticytokine effect of alpha-MSH in glioma cells may be mediated by human melanocortin-1 receptors; mRNA for this receptor subtype was isolated from resting A-172 cells. These results, combined with prior evidence of effectiveness of alpha-MSH molecules in modulating inflammatory processes and of their low toxicity, suggest that the molecules may be useful in the treatment of CNS disorders that have an inflammatory component.

Astrocytes↗
PubMedDate not supplied

IL-6/BSF-2 selectively stimulates the GO----S progression of CD8+ lymphocytes.

IL-6 preferentially promotes the DNA synthesis of human peripheral blood CD8+, rather than CD4+, lymphocytes in presence of PHA: this effect is observed in serum-free cultures of greater than 99% purified CD8+ lymphocytes. However, IL-6 is able to stimulate DNA synthesis of CD8+ lymphocytes triggered by a mitogenic anti-CD2 mAb, but not by anti-CD3 mAb: these results suggest that IL-6 selectively induces activation of CD8+ lymphocytes through the CD2 rather than the CD3 pathway. Limiting dilution analysis indicates that accessory cells are not required to mediate the action of IL-6 on CD8+ cells. Furthermore, this action is not blocked by addition of mAb neutralizing either IL-2 or IL2R, thus suggesting that IL-6 does not act via IL-2. CD8+ lymphocytes grown in the presence of PHA + IL-6 incorporate (3H)-thymidine to the same extent as those stimulated with PHA + IL-2, but do not increase in number until day 6 of culture. It is hence apparent that the stimulating activity of IL-6 on CD8+ lymphocytes is restricted to the GO----S phase progression, but does not lead to mitosis. IL-6 receptors are expressed on resting CD4+ and CD8+ lymphocytes: their expression is significantly enhanced on both activated CD4+ and CD8+ cells. Scatchard analysis of (125I)-IL-6 binding data showed the presence of high (Kd, 3 x 10(-10) M) and low (Kd, 6 x 10(-8) M) affinity IL6R on both lymphocyte populations. Similarly, mRNA encoding IL6R was detected in both CD4+ and CD8+ lymphocytes. Thus, our studies indicate that IL-6 directly and selectively stimulates the GO----S progression of CD8+ lymphocytes in the presence of mitogen and absence of IL-2: this phenomenon may be of interest for the elucidation of mechanisms activating cytotoxic T lymphocytes.

Antibodies, Monoclonal↗