GHRELIN LEVEL IN PATIENTS WITH LIVER CIRRHOSIS.

BACKGROUND: Ghrelin is a gastro-duodenal hormone which plays a major role in the regulation of food intake, energy balance and gastrokinesis. Ghrelin represents a novel biological marker for assessment of the presence as well as the severity of liver cirrhosis. We aimed to measure the level of plasma ghrelin in patients with liver cirrhosis (compensated and decompensated) and to correlate its level with different studied clinical and laboratory parameters. SUBJECTS AND METHODS: 40 cirrhotic patients were included in a cross-sectional study and divided equally according to the Child-Pugh classification into Group I: patients with compensated liver cirrhosis (Child A), and Group II: patients with decompensated liver cirrhosis (Child B|C). Also, 20 age and sex matched healthy subjects were included as a control group (Group III). All patients were subjected to: full history taking, full clinical examination, routine biochemical studies together with estimation of plasma ghrelin level, assessment of the severity of liver disease according to Child-Pugh classification, also, abdominal ultrasonography was done. RESULTS: Plasma ghrelin level was low among cirrhotic patients (both compensated and decompensated) in comparison to normal control subjects. CONCLUSION: Ghrelin can be used as a serum biomarker for detection and assessment of the severity of liver cirrhosis.

Tyrosine phosphorylation of the vav proto-oncogene product links FcepsilonRI to the Rac1-JNK pathway.

Stimulation of high affinity IgE Fc receptors (FcepsilonRI) in basophils and mast cells activates the tyrosine kinases Lyn and Syk and causes the tyrosine phosphorylation of phospholipase C-gamma, resulting in the Ca2+- and protein kinase C-dependent secretion of inflammatory mediators. Concomitantly, FcepsilonRI stimulation initiates a number of signaling events resulting in the activation of mitogen-activated protein kinase (MAPK) and c-Jun NH2-terminal kinase (JNK), which, in turn, regulate nuclear responses, including cytokine gene expression. To dissect the signaling pathway(s) linking FcepsilonRI to MAPK and JNK, we reconstructed their respective biochemical routes by expression of a chimeric interleukin-2 receptor alpha subunit (Tac)-FcepsilonRI gamma chain (Tacgamma) in COS-7 cells. Cross-linking of Tacgamma did not affect MAPK in COS-7 cells, but when coexpressed with the tyrosine kinase Syk, Tacgamma stimulation potently induced Syk and Shc tyrosine phosphorylation and MAPK activation. In contrast, Tacgamma did not signal JNK activation, even when coexpressed with Syk. Ectopic expression of a hematopoietic-specific guanine nucleotide exchange factor (GEF), Vav, reconstituted the Tacgamma-induced, Syk- and Rac1-dependent JNK activation; and tyrosine-phosphorylation of Vav by Syk stimulated its GEF activity for Rac1. Thus, these data strongly suggest that Vav plays a critical role linking FcepsilonRI and Syk to the Rac1-JNK pathway. Furthermore, these findings define a novel signal transduction pathway involving a multimeric cell surface receptor acting on a cytosolic tyrosine kinase, which, in turn, phosphorylates a GEF, thereby regulating its activity toward a small GTP-binding protein and promoting the activation of a kinase cascade.

Altered leukotriene generation in leukocytes from cystinotic children.

Upon in vitro stimulation with 10 microM ionophore A 23187 for 5 min at 37 degrees C, the generation of leukotriene (LT) C4 in polymorphonuclear leukocytes (PMNL) from nine untreated cystinotic children was significantly increased compared with that in eight control children (p < 0.01) and 25 normal adults (p < 0.001) (417.4 +/- 70.0 versus 177.0 +/- 30.9 and 164.9 +/- 19.5 pmol/l x 10(7) cells, respectively). Concomitantly with the increased generation of LTC4, LTB4 production in PMNL from untreated cystinotic children was decreased compared with controls, whereas the total amount of LTA4 derivatives was similar in the three groups. The increase in LTC4 production was not related to the number of eosinophils present in the PMNL preparations from cystinotic children, which was similar to that of control subjects. PMNL from cystinotic children treated with cysteamine, an aminothiol compound that decreases the intracellular cystine content, generated smaller amounts of LTC4 upon ionophore A 23187 stimulation than PMNL from untreated cystinotic children. In addition, abrogation of the cysteamine treatment for 3 or 4 d led to an increase in LTC4 production. These findings suggest that the metabolic abnormalities taking place in infantile cystinosis may favor the biosynthesis of LTC4 from PMNL.

Report on a workshop convened to discuss the pathological and staging classifications of gastrointestinal tract lymphoma.

It was considered timely to review the pathological and staging classifications of GI tract lymphoma. This meeting specifically did not address the question of treatment; the management of GI tract lymphoma could perhaps form the basis for a further workshop. The following recommendations were made: to adopt the Isaacson histological classification, that all patients with GI tract lymphoma be investigated uniformly, to record the prognostic factors described above, to use the staging classification shown above. It is hoped that these recommendations will be taken into account in the design of future clinical trials of therapy for GI tract lymphoma.

Involvement of p72syk, a protein-tyrosine kinase, in Fc gamma receptor signaling.

Previous studies have demonstrated that multichain immune recognition receptors, such as the T-cell receptor, signal their occupancy by inducing tyrosine phosphorylation of cellular protein substrates. Type I and II receptors for the Fc portion of IgG are single-chain immune recognition receptors having external, transmembrane, and cytoplasmic domains. In the present study, we have investigated the possibility that, upon engagement, Fc gamma receptors induce protein-tyrosine phosphorylation. Our findings reveal increased phosphorylation of a number of proteins on tyrosine residues after cross-linking of either high (Fc gamma RI) or low (Fc gamma RII) affinity receptors expressed on HL60 cells. Engagement of Fc gamma RII induced rapid tyrosine phosphorylation that decayed to basal levels by 40 min. In contrast, phosphorylation induced by Fc gamma RI cross-linking was more delayed, peaking at 5-10 min, and returning to basal levels by 60 min. Kinase assays of cellular proteins immunoprecipitated from lysates of activated cells by antibody to phosphotyrosine revealed phosphorylation of a 72-kDa molecule that was not present in lysates of resting cells. This phosphoprotein was identified as p72syk by immunoprecipitation with antibodies directed against two different regions of the syk gene product. Immunoprecipitation with antibodies against p72syk followed by immunoblotting with anti-phosphotyrosine antibodies revealed an activation-dependent tyrosine phosphorylation of p72syk. Thus, our present findings demonstrate induction of protein-tyrosine phosphorylation following engagement of monomeric immune recognition receptors and identify p72syk as a tyrosine kinase substrate involved in signaling by Fc gamma RI and Fc gamma RII.

Single-dose murine monoclonal antibody ricin A chain immunotoxin in the treatment of metastatic melanoma: a phase I trial.

To determine the maximally tolerated dose of a ricin A chain-conjugated antimelanoma antibody (XomaZyme-Mel), 20 patients with metastatic melanoma were treated with escalating doses of the murine immunotoxin given as single intravenous infusion over 30 minutes. The starting dose was 0.6 mg/kg and was escalated in five groups to a maximum of 1.6 mg/kg. The maximally tolerated dose was 1.25 mg/kg as three of six patients treated at 1.6 mg/kg developed unacceptable toxicity. The dose-limiting toxicity consisted of profound fatigue, myalgias, and arthralgias. These occurred within 4 days and resolved in 7 to 10 days. Other non-dose-limiting toxicities encountered consisted of hypoalbuminemia, weight gain, peripheral edema, mild hypotension, and flu-like syndrome; the severity of these was also dose related. In addition, two allergic reactions occurred, one severe. There was one durable complete response of 12+ months' duration and one brief mixed response lasting 3 months. We conclude that the maximum tolerated single dose of XomaZyme-Mel is 1.25 mg/kg. Phase I studies evaluating 1.25 mg/kg given in multiple doses at 2- to 4-week intervals and phase II studies to determine the response rate of a single 1.25 mg/kg dose are warranted.

A neonate with bilateral refractory chylothorax--a case report.

A thirty six week gestation male baby weighing three kilogram was born to a twenty five year old mother by spontaneous vaginal delivery. At four hours of life, the baby developed respiratory distress with cyanosis and was admitted to the neonatal intensive care unit. There was clinical and radiological evidence of bilateral pleural effusion. Thoracentesis revealed a transudate. Repeated thoracentesis was necessary to relieve the respiratory distress. Subsequently, multi resistant Klebsiella aerogenes was isolated from the blood. The baby expired due to gram negative sepsis.

Regression of hepatic metastases from gastrointestinal leiomyosarcoma after hepatic arterial chemoembolization.

Two patients with gastrointestinal leiomyosarcoma metastatic to the liver were treated by hepatic chemoembolization with cisplatin and polyvinyl sponge followed by hepatic arterial infusion of vinblastine. Effective palliation in terms of durable tumor regression was achieved in both patients after two chemoembolization-infusion procedures. These results suggest that regional therapy may offer new hope for the subset of sarcoma patients who have liver metastases resistant to combination systemic chemotherapy.

Immunoregulatory functions of paf-acether. III. Down-regulation of CD4+ T cells high-affinity IL-2 receptor expression.

In the present report, we further explored the mechanisms by which 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine (paf-acether), a phospholipid mediator of inflammation inhibited PHA-induced CD4+ cell proliferation. Evidence was obtained that CD4+ cells stimulated with either PHA or immobilized OKT3 in the presence of paf at concentrations that block CD4+ cell proliferation, exhibited a marked decrease in high affinity IL-2R expression. Importantly, paf did not prevent the binding of IL-2 to its receptor. Scatchard analysis of the binding data indicated that paf caused more than 50% decrease in the number of IL-2 high affinity sites per cell, whereas the receptor ligand affinity remained essentially constant. Moreover, the down-regulation of high affinity IL-2R was also accompanied by a loss of IL-2-dependent proliferative capacity. Together these data suggest that decreased expression of high affinity IL-2R may contribute to the diminished proliferative activity observed in CD4+ cells stimulated with PHA or immobilized OKT3 in the presence of paf. They further emphasize the potential role of lipid proinflammatory mediators such as paf in the regulation of T cell activation.

Splenic versus hepatic artery infusion of interleukin-2 in patients with liver metastases.

In an attempt to improve the therapeutic index of recombinant interleukin-2 (rIL-2) by generating or activating lymphokine-activated killer (LAK) cells and tumor-infiltrating lymphocytes (TIL) regionally and/or in situ, we randomly assigned 28 patients with liver metastases to receive rIL-2 by continuous infusion for 5 days via either the splenic artery or the hepatic artery. Clinically significant and lasting tumor regression was observed only in two of 28 patients (7%), one in each of the two treatment arms. The maximum-tolerated daily dosage of rIL-2 was 3 x 10(6) U/m2; beyond this dosage, toxicity was excessive. Peripheral LAK cell activity measured in vitro and clinical tumor regression did not correlate. This observation, coupled with the equal distribution of regressions between the two treatment arms, raises the possibility that tumor regression, rare though it may be in response to rIL-2 administration, is largely mediated by TIL activation and not by LAK cell generation.

Immunoregulatory functions of paf-acether. IV. Enhancement of IL-1 production by muramyl dipeptide-stimulated monocytes.

paf-Acether (paf) is a phospholipid mediator of inflammation released from monocytes along with IL-1. In this study, we have examined the role of paf on IL-1 production by human monocytes. When paf from 1 nM to 5 microM, but not its precursor lyso paf, was added to monocytes in the presence of muramyl dipeptide (MDP) or LPS, a marked increase in IL-1 activity over the value with MDP alone was observed. In contrast, paf alone had minimal activity over the same dose range. Antibodies against rHu IL-1 alpha and rHu IL-1 beta neutralized the increased IL-1 activity. Interestingly, MDP that prompts monocytes to synthesize IL-1, induced the synthesis of paf, as well. Most of the paf produced remained cell-associated and always preceded IL-1 synthesis. When the paf receptor antagonist, L-652,731 was added to monocytes, it prevented the enhancement of IL-1 activity induced by exogenous paf. In contrast, L-652,731 had little effect on MDP-induced IL-1 synthesis in the absence of exogenous paf. This may indicate that there are alternative mechanisms involved in the sequences of events leading to IL-1 production. It is also conceivable that the paf receptor antagonist is not able to compete or inhibit endogenous paf as well as it does for exogenous paf. Nevertheless, exogenous paf in association with a second signal, modulates IL-1 production from human monocytes in a positive manner. This may constitute another means through which paf can modulate inflammatory and immune reactions.

Malignant struma ovarii: report of two cases and selected review of the literature.

Malignant struma ovarii is an extremely rare tumor. Two new cases are described and current perspectives provided. Both cases are examples of the mixed form of the disease, and both were treated by surgery alone. One patient underwent total hysterectomy and bilateral salpingooophorectomy; the other had unilateral salpingo-oophorectomy. Both patients remained free of recurrent disease at 20 and 33 months from diagnosis. The controversies relating to therapy and diagnosis are discussed in detail.

Presence of paf-acether in human thymus.

Paf-acether (paf) is a phospholipid mediator of inflammation endowed with major immunoregulatory properties. The present study demonstrates that human thymus contains large amounts of paf, as well as paf precursors. In addition, isolated thymic cells produced paf under ionophore stimulation. Paf from thymus exhibited the same biological and physiochemical properties as synthetic paf. The purity and molecular structure of paf from thymus were further characterized by reverse-phase HPLC and gas chromatography with electron-capture detection. These findings may have important implications since thymus microenvironment is essential in the proper development of bone marrow progenitors committed to the T cell lineage into thymocytes capable of emigrating to the periphery as functional T lymphocytes.

Malignant cardiac fibrous histiocytomas and angiosarcomas: MR features.

Primary tumors of the heart are rare, and one-third of them are malignant. The magnetic resonance (MR) features, their specificity, and significance in two patients with malignant fibrous histiocytoma and three patients with angiosarcoma are presented and the literature briefly reviewed. Malignant fibrous histiocytoma occurred in the left atrium and demonstrated slightly heterogeneous intermediate signal intensity on T1-weighted images and high signal intensity on T2-weighted images. The angiosarcomas involving primarily the right heart were more varied in MR appearance with heterogeneous signals. The extensive angiosarcomas almost circumferentially involving the epicardium and pericardium showed the "cauliflower" appearance with focal areas of increased signal intensity probably related to thrombosis or hemorrhage. Magnetic resonance provided detailed anatomic information and characterization of malignant cardiac tumors.

Biochemical and morphological modifications in dexamethasone-treated mouse bone marrow-derived mast cells.

Addition of 1 microM dexamethasone (DM) to bone marrow-derived mast cells (BMMC) induced a time-dependent increase in cell histamine content. The latter reached a plateau of 2.5 micrograms/1 x 10(6) cells after 11 days in culture, compared with 100 ng/1 x 10(6) for untreated BMMC. Steroids, such as beta-estradiol, androsterone, and testosterone (1 microM), did not alter the histamine content of BMMC, whereas progesterone (1 microM) induced a moderate increase. Other glucocorticosteroids also enhanced histamine content, suggesting that the observed increase was specific for glucocorticosteroid. Treatment of BMMC with 1 microM DM for 14 days inhibited the Ag-induced, IgE-mediated release of histamine, beta-hexosaminidase, platelet-activating factor-acether, LTB4, and LTC4 by 65 +/- 3%, 66 +/- 1%, 93 +/- 3%, 66 +/- 2%, and 74 +/- 10%, respectively (mean +/- 1 SD, n = 3). In contrast with untreated cells which produce less than 2 ng/1 x 10(6) cells PGD2 after Ag challenge, DM-treated BMMC generated 16.8 +/- 0.3 ng/1 x 10(6) cells PGD2. Moreover, most of DM-treated BMMC became Alcian blue+/safranin+ and by ultrastructure, exhibited numerous cytoplasmic granules filled with abundant and uniform electron-dense matrix. The present results indicate that DM-treated BMMC exhibit biochemical and functional properties different from immature untreated cells, suggesting that a maturation-like process occurred in vitro during DM treatment.

Immunoregulatory functions of paf-acether. II. Decrease of CD2 and CD3 antigen expression.

Paf-acether (platelet-activating factor) is a phospholipid initially described as a potent platelet-aggregating compound. It is produced by numerous cell types and is now considered as an important mediator of cell-cell interactions. The effect of paf-acether on the expression of CD2 and CD3, two human T cell surface glycoproteins, was investigated by indirect immunofluorescence and flow cytometry. Paf-acether partially down-regulated, in a time- and dose-dependent manner, CD2 and CD3 but not HLA class I antigen expression on peripheral human T cells and Jurkat cells. Lysophosphatidylcholine, a phospholipid closely related to paf-acether, had no detectable modulatory effect on CD2 and CD3 expression. In addition to CD2/CD3 modulation, paf-acether markedly inhibited T cell proliferative response not only to phytohemagglutinin or concanavalin A but also to anti-CD3 or a stimulatory combination of anti-CD2 monoclonal antibodies. These data demonstrate for the first time that lipid mediators such as paf-acether might be involved in the regulation of the expression of cell surface glycoproteins that are essential in the execution of T cell function.

VP-16-based regimen in adult acute nonlymphoblastic leukemia.

A new VP-16-based drug combination was utilized in the treatment of 3 adult patients with acute nonlymphoblastic leukemia. Marrow aplasia was noted in all patients on day 7. While myeloid regeneration was noted on day 14, there was no evidence of regeneration of the erythroid series before day 21 in any of the 3 patients, and maturation of this cell line was never complete before day 35. Such prolonged suppression of the erythroid series has not been described with standard chemotherapy. Because of this protracted suppressive effect of the above regimen on erythroid cells, we propose to explore its therapeutic potential in a pilot study employing such a regimen in the treatment of erythroleukemia.

Immunoregulatory functions of paf-acether. I. Effect of paf-acether on CD4+ cell proliferation.

Paf-acether or platelet-activating factor (1-0-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is a phospholipid mediator of inflammation initially described as a potent platelet-aggregating compound. It is newly formed by a variety of cells including monocytes and is now recognized as a major mediator of cell-cell interactions. The present studies were undertaken to determine whether paf-acether could modulate T cell function. We found that addition of paf-acether to CD4+ cells cultured with phytohemagglutinin markedly inhibited the proliferative response in a dose-dependent manner. Maximal inhibition occurred when paf-acether was present during the first 24 hr of cell culture and the presence of paf-acether did not alter the kinetics of CD4+ cell proliferation. Importantly, the mechanism by which paf-acether inhibited the proliferative response was not related to inhibition of interleukin 2 (IL-2) secretion since the amount of IL-2 in cultures was not altered and addition of exogenous IL-2 failed to restore the CD4+ cell proliferative response. Further, as judged by indirect immunofluorescence, paf-acether did not inhibit IL-2 receptor expression. Taken together, these data indicate that paf-acether interferes with some processes leading to CD4+ cell proliferation. This new role for the chemically defined monokine paf-acether emphasizes the potential role of inflammatory lipid mediators in the regulation of T cell response.