Mechanisms for experimental buprenorphine hepatotoxicity: major role of mitochondrial dysfunction versus metabolic activation.

Background/aims: Although sublingual buprenorphine is safely used as a substitution drug in heroin addicts, large overdoses or intravenous misuse may cause hepatitis. Buprenorphine is N-dealkylated to norbuprenorphine by CYP3A.

Methods: We investigated the mitochondrial effects and metabolic activation of buprenorphine in isolated rat liver mitochondria and microsomes, and its toxicity in isolated rat hepatocytes and treated mice.

Clean conditions for the determination of ultra-low levels of mercury in ice and snow samples.

Laboratory facilities and methods are presented for the determination of ultra-low levels of mercury (Hg) in ice and snow samples originating from polar ice caps or temperate regions. Special emphasis will be given to the presentation of the clean laboratory and the cleaning procedures. The laboratory is pressurized with air filtered through high efficiency particle filters.

Idiotypic regulation of anti-factor VIII antibodies.

This review focuses on the relationship between natural autoreactivity, autoimmunity in disease and antigen-driven immune responses to factor VIII and on idiotype-mediated immune regulation of anti-factor VIII antibodies in health and disease.

Factor VIII inhibitor with catalytic activity towards factor VIII.

Hemophilia A is an X chromosome-linked recessive disorder resulting in defective or deficient factor VIII (FVIII) molecules, which, in its severe form, is a life-threatening, crippling hemorrhagic disease. Infusion of purified FVIII to patients with severe hemophilia A results in approximately 25% of the cases in the emergence of anti-FVIII antibodies (inhibitors) that are known to neutralize the procoagulant activity of FVIII by steric hindrance. We recently reported on the proteolysis of FVIII by alloantibodies in the plasma of two high responder patients with severe hemophilia A, demonstrating a new mechanism by which FVIII inhibitors may prevent the pro-coagulant function of FVIII.

Prevention of acute rejection with antithymocyte globulin, avoiding corticosteroids, and delaying cyclosporin after renal transplantation.

Background: Despite their well-known side-effects, corticosteroids (Cs) are currently used after kidney transplantation. Avoidance of Cs may improve patient quality of life and eventual long-term survival. We report on a regimen using antithymocyte globulin (ATG) and mycophenolate mofetil (MMF) for induction, and cyclosporin (CsA) plus MMF for maintenance treatment of recipients of primary kidney transplantation.

Natural antibodies to factor VIII.

Anti-factor VIII antibodies represent a unique model to study the relationship between natural autoreactivity (natural antibodies to factor VIII of healthy individuals), disease-associated autoimmunity ("spontaneous" factor VIII inhibitors of patients with anti-factor VIII autoimmune disease) and antigen-driven immune responses (immune inhibitors in multitransfused patients with hemophilia A) to a single human protein antigen. Although natural and disease-associated anti-factor VIII antibodies are not readily distinguished based on the comparison of their isotypic distribution and epitope mapping, available studies of cross-reacting idiotypes suggest that factor VIII inhibitors in patient's plasma encompass two populations of anti-factor VIII antibodies. Some antibodies result from the clonal expansion of B lymphocytes that exist before treatment with factor VIII and secrete anti-factor VIII antibodies with properties similar to those of natural anti-factor VIII antibodies present in healthy individuals; other inhibitors are produced by B cell clones that have undergone affinity maturation and hypermutation of the V regions of the antibodies they produce.

Cytochrome P450-generated reactive metabolites cause mitochondrial permeability transition, caspase activation, and apoptosis in rat hepatocytes.

Although cytochrome P-450 (CYP)-generated reactive metabolites can cause hepatocyte apoptosis, the mechanism of this effect is incompletely understood. In the present study, we assessed the hepatotoxicity of skullcap, a diterpenoid-containing herbal remedy. Male rat hepatocytes were incubated for 2 hours with skullcap diterpenoids (100 microg/mL).

IgG-secreting lymphoplasmacytoid leukaemia: a B-cell disorder with extensively mutated VH genes undergoing Ig isotype-switching frequently associated with trisomy 12.

We investigated 16 patients with elevated serum monoclonal IgG and a leukaemic B-cell lymphocytic disorder different from multiple myeloma. Their clinical history was that of a non-aggressive disease with dominant splenomegaly and long survival. Whereas abnormal blood and bone marrow cells were predominantly small lymphocytes with a few lymphoplasmacytoid cells, histopathological features included a lymphoplasmacytic infiltrate in eight cases.

Salvage extended-field irradiation in follicular non-Hodgkin's lymphoma after failure of chemotherapy.

Purpose: To evaluate the efficacy of total abdominopelvic (TAI) and total body irradiation (TBI) in heavily pretreated follicular non-Hodgkin's lymphoma (NHL).

Patients And Methods: From 1983 to 1998, 34 patients received TAI (n = 22) or TBI (n = 12). All had Stage III or IV, Class B, C, D NHL in the working formulation and failed after receiving 1-5 regimens of chemotherapy.

Antibodies to the FVIII light chain that neutralize FVIII procoagulant activity are present in plasma of nonresponder patients with severe hemophilia A and in normal polyclonal human IgG.

We have analyzed the properties of anti-factor VIII (FVIII) immunoglobulin (Ig) G recovered by affinity chromatography on FVIII-Sepharose from the IgG fraction of the plasma of healthy individuals and nonresponder patients with hemophilia A. Affinity-purified anti-FVIII antibodies were found to neutralize FVIII activity and to bind to FVIII with an affinity similar to that of anti-FVIII IgG that had been affinity-purified from the plasma of inhibitor-positive hemophilia patients and of patients with anti-FVIII autoimmune disease. The antibodies also exhibited patterns of reactivity with thrombin-digested FVIII similar to those of FVIII inhibitors and preferentially recognized epitopes located in the light chain of FVIII.

Opening of the mitochondrial permeability transition pore causes matrix expansion and outer membrane rupture in Fas-mediated hepatic apoptosis in mice.

Although Fas stimulation has been reported to cause outer mitochondrial membrane rupture in Jurkat cells, the mechanism of this effect is debated, and it is not known if outer membrane rupture also occurs in hepatocyte mitochondria. We studied the in vivo effects of Fas stimulation on ultrastructural lesions and mitochondrial function in mice. Four hours after administration of an agonistic anti-Fas antibody (8 microg/animal), caspase activity increased 5.

Interaction of anti-HLA antibodies with pig xenoantigens.

Background: Many patients with renal failure are condemned to long-term dialysis with little prospect of transplantation because they are highly sensitized with immunoglobulin G (IgG) directed against class I human leukocyte antigens (HLA) of virtually all donors. Xenotransplantation could represent an attractive solution providing their alloantibodies (alloAb) do not recognize porcine motifs. Hitherto there has been no in vivo demonstration of any cross-reactivity and the objective of this work was to investigate this problem using a technique of extracorporeal pig kidney perfusion as a model of clinical xenografting.

Highly altered V beta repertoire of T cells infiltrating long-term rejected kidney allografts.

Chronic rejection represents a major cause of long-term kidney graft loss. T cells that are predominant in long-term rejected kidney allografts (35 +/- 10% of area infiltrate) may thus be instrumental in this phenomenon, which is likely to be dependent on the indirect pathway of allorecognition only. We have analyzed the variations in T cell repertoire usage of the V beta chain at the complementary determining region 3 (CDR3) level in 18 human kidney grafts lost due to chronic rejection.

Catalytic activity of antibodies against factor VIII in patients with hemophilia A.

Hemophilia A is an X chromosome-linked recessive disorder resulting in defective or deficient factor VIII (FVIII) molecules, which, in its severe form, is a life-threatening and crippling hemorrhagic disease. Infusion of homologous FVIII to patients with severe hemophilia A results, in 25% of patients, in the emergence of alloantibodies against FVIII (inhibitors)( ref. 1) that inhibit FVIII procoagulant activity by steric hindrance of the interaction of FVIII either with stabilizing molecules, with molecules essential for its activity or with activating molecules.

Multiple rheumatoid bursitis with migrating chylous cysts. Report of a case in a European woman and review of the literature.

We report a case of recurrent multiple bursitis (19 episodes at nine sites) requiring seven surgical procedures in a European women with a 38-year history of severe, nodular, destructive seropositive rheumatoid arthritis unresponsive to second-line drugs. The episodes of bursitis were not correlated with activity of the joint disease. Some cysts migrated over a considerable distance.

Mutated cytochrome b as a determinant of a new monoclonal antibody (H8.98) on renal carcinoma cell lines recognized by a Vgamma3Vdelta1(+) T-cell clone.

We generated a monoclonal antibody (MAb), H8.98, that recognizes an antigen shared by 50% of examined renal carcinoma cell (RCC) lines and is susceptible to lysis by a Vgamma3Vdelta1(+) T-cell clone derived from RCC tumor-infiltrating lymphocytes. H8.

Interleukin 1 and interleukin 1beta converting enzyme (caspase 1) expression in the human colonic epithelial barrier. Caspase 1 downregulation in colon cancer.

Background: Interleukin (IL) 1beta converting enzyme (now known as caspase 1) is able to process pro-IL-1beta into its active form and is involved in proapoptotic signalling.

Aims: To characterise IL-1 and caspase 1 expression in human colonic epithelial cells.

Methods: Intracellular IL-1 content (IL-1alpha and IL-1beta) was measured by ELISA in freshly isolated human normal colonocytes.

Prolongation of heart xenograft survival in a hamster-to-rat model after therapy with a rationally designed immunosuppressive peptide.

Background: Modification of the aminoacid sequence of peptides derived from the HLA class I heavy chain in combination with computer rational design resulted in the development of a peptide, RDP1258, with enhanced immunosuppressive activity.

Methods: We evaluated the activity of this peptide, analyzing infiltrate by immunohistology and cytokine transcripts by reverse transcriptase-polymerase chain reaction method, in a hamster-to-rat xenograft model where recipients were treated with cobra venom factor (CVF) and peptide.

Results: Although CVF or peptide alone had no effect, a combination of CVF/peptide RDP1258 resulted in a significant prolongation of graft survival (7.

An alcoholic binge causes massive degradation of hepatic mitochondrial DNA in mice.

Background & Aims: Ethanol causes oxidative stress in the hepatic mitochondria of experimental animals and mitochondrial DNA deletions in alcoholics. We postulated that ethanol intoxication may cause mitochondrial DNA strand breaks.

Methods: Effects of an intragastric dose of ethanol (5 g/kg) on hepatic mitochondrial DNA levels, structure, and synthesis were determined by slot blot hybridization, Southern blot hybridization, and in vivo [3H]thymidine incorporation, respectively.

Detection of translocation t(11;14)(q13;q32) in mantle cell lymphoma by fluorescence in situ hybridization.

To assess an unequivocal diagnosis of mantle cell lymphoma (MCL), we have developed a fluorescence in situ hybridization (FISH) assay, enabling the demonstration of t(11;14)(q13;q32) directly on pathological samples. We have first selected CCND1 and IGH probes encompassing the breakpoint regions on both chromosomes. Then, we have defined experimental conditions enabling us to obtain bright clear-cut signals in all of the samples, independently of the initial fixation conditions.

[Physiopathology of tumor-induced osteolysis].

Osteolysis, the most common expression of bone tumor, can cause pain, pathological fracture, epidural spinal cord compression and hypercalcemia. Multinucleated osteoclast-like cells, the main agents in bone resorption, are numerous in benign giant cell tumor of bone and can be recruited and activated by various carcinoma cell lines in vitro in animal models. Polykarion macrophages are also able to resorb bone matrix in a favourable tumoral environment.

Expression of leukemia inhibitory factor by cartilage-forming tumors of bone: an immunohistochemical study.

Recent studies have implicated leukemia inhibitory factor in connective-tissue metabolism involving the remodeling of bone and the destruction of cartilage tissue. This cytokine, which has also been implicated in the proliferation of solid tumor, is expressed by osteotropic tumor cell lines. The present study investigated the presence of leukemia inhibitory factor in cartilage tissue harvested from cartilage-forming bone tumors.

Epstein-Barr virus-associated B cell lymphoproliferative disease after non-myeloablative allogeneic stem cell transplantation.

There is a growing interest in the evaluation of non-myeloablative conditioning therapy for allogeneic stem cell transplantation. Such regimens are expected to produce less toxicity while allowing both engraftment and a graft-versus-disease effect from the large number of donor-derived immunocompetent T lymphocytes given with the stem cells. Heavy immunosuppression used in recipients may have unexpected consequences.