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Biomedical subjects

J J Ballet

Publications and source records attributed to J J Ballet.

At least 37 records · Page 2Linked to original sources
PubMed1999

IgE multiple myeloma.

IgE multiple myeloma is a rare disease characterized by a high frequency of Bence-Jones proteinuria and plasma cell leukaemia when compared to other isotypes of monoclonal proteins. Only 35 cases have been reported. We describe a 70-year-old woman with a stage III IgE kappa multiple myeloma presenting with a sacral plasmacytoma. Immunological and biochemical studies showed IgE kappa producing tumoral plasma cells. Serum total IgE was high without clinical symptoms suggesting an hyperIgE syndrome or mast cell activation. The patient underwent surgical removal of the sacral tumor and monthly melphalan-prednisone treatment together with intravenous pamidronate infusions. Magnetic Resonance Imaging (MRI) of the dorsolumbar spine revealed an epidural process leading to T6-T9 radiotherapy. Bone densitometry showed a decreased bone mineral content supporting the management of myeloma-related osteoporosis with bisphosphonate infusions. A good partial response with plateau-phase and increase of bone mineral content was achieved after 1 year of treatment and still persists after a 28 months follow-up.

Aged↗
PubMed1999

In vitro evaluation of B-CLL cells apoptotic responses to irradiation.

Defective apoptosis is a mechanism which could possibly explain B chronic lymphocytic leukemia (B-CLL) cell accumulation. Differences in evolution and prognosis of B-CLL patients may be due to heterogeneity in apoptotic cell death. We studied the apoptotic response to in vitro gamma radiation of blood mononuclear cells from 18 untreated B-CLL patients. In cells irradiated with 2, 4 or 8 Gy and then cultured for 20 hours, the percentage of trypan blue excluding (viable) cells was not modified (>92%). An apoptotic response to irradiation was detected in the majority of the patients, but the individual percentage of apoptotic cells varied widely (8 to 81% after 8 Gy irradiation) in individual cases. The flow cytometric analysis of nick-end DNA labeling demonstrated a dose effect of irradiation, particularly in patients with an apoptotic response of over 20%. In the future, a valuable clue to the selection of irradiation regimens for B-CLL patients may be the investigation of correlations between in vitro radiation-induced apoptosis and the in vivo response to radiation therapy.

Aged↗
PubMed1998

High frequency of IgG antagonizing follicle-stimulating hormone-stimulated steroidogenesis in infertile women with a good response to exogenous gonadotropins.

OBJECTIVE: To investigate the presence of FSH-blocking IgG in infertile women. DESIGN: Retrospective study. Sera from patients and controls were processed for IgG purification, and purified IgG were tested at various concentrations for their ability to inhibit the recombinant human FSH-induced P production in vitro by human granulosa cells. SETTING: Departments of Endocrinology, and Obstetrics and Gynecology, University of Caen. PATIENT(S): Fifty-seven infertile women including 14 women with premature ovarian failure (POF), 29 women with a poor response to IVF-ET, and 14 women with a good response to IVF-ET. Controls consisted of 22 healthy age-matched women. INTERVENTION(S): IVF-ET allowed human granulosa cell pooling and culture for FSH bioassay. MAIN OUTCOME MEASURE(S): Inhibition by purified IgG of the in vitro recombinant human FSH-induced P production by human granulosa cells. RESULT(S): Blocking IgG were identified in only 3 of 14 POF and in 2 of 29 women with a poor response to IVF-ET. In contrast, IgG from women with a good response to IVF-ET inhibited significantly P production, and blocking IgG were detected in 85% women with a good response to IVF-ET. CONCLUSION(S): This study identified FSH-blocking IgG in a high proportion of women with a good response to IVF-ET. The significance of this remains questionable.

Adult↗
PubMed1998

Hydrogen peroxide gas plasma sterilization is effective against Cryptosporidium parvum oocysts.

The aim of this work was to evaluate in an immunosuppressed rat cryptosporidiosis model a new method that combines vacuum and low-temperature hydrogen peroxide gas plasma for sterilization of endoscopic material contaminated by Cryptosporidium parvum. Rats were challenged with oocysts either air-dried or air-dried and treated with vacuum alone or associated with gas plasma. No rat was found infected after gas plasma exposure of oocysts, whereas vacuum or air-drying alone resulted only in a decreased infectivity.

Animals↗
PubMed1998

In vitro evaluation of drug susceptibilities of Babesia divergens isolates.

The susceptibilities of three bovine and two human Babesia divergens isolates to antimicrobial agents were evaluated in vitro by a tritiated hypoxanthine incorporation assay. The MICs at which 50% of isolates are inhibited (MIC50s) for mefloquine (chlorhydrate), chloroquine (sulfate), quinine (chlorhydrate), clindamycin (phosphate), pentamidine (isethionate), phenamidine (isethionate) plus oxomemazine (chlorhydrate), lincomycin (chlorhydrate monohydrate), and imidocarb (dipropionate) were determined. Except for imidocarb, the MIC50s observed for the different isolates were close. Imidocarb and the combination of phenamidine plus oxomemazine exhibited the highest in vitro activity, while antimalarial agents such as mefloquine, choroquine, and quinine were inactive. Other drugs had intermediate activities. The data support further in vitro evaluation of antimicrobial agents active against B. divergens for the improvement of therapeutic strategies.

Animals↗
PubMed1998

Viability of Cryptosporidium parvum oocysts in natural waters.

Water-borne transmission of the coccidium Cryptosporidium parvum Tyzzer, 1912 is frequently responsible for outbreaks of human cryptosporidiosis. One of the most important was reported in 1993 in Milwaukee in the United States, where 403,000 cases were recorded. The determination of the percentage of oocysts excystated is the first step in evaluating their viability, but it alone is not sufficient. This percentage depended on the conditions of storage and also the presence of oxidant or disinfectent agents in water. The percentage of excystation is not always related to viability. Therefore, determination of the viability of excysted sporozoites by determining their infectivity for enterocytic Caco2 cell lines in culture provides information essential for evaluating the risk of contaminated drinking water.

Animals↗
PubMed1996

Biliary tract cryptosporidiosis immunosuppressed rat model.

Rats immunosuppressed by hydrocortisone acetate and a low protein diet were challenged with Cryptosporidium Parvum oocysts and studied on days 10, 35 and 70 post-infection. The biliary tract was found to be a major site of parasite infection. C. parvum was visible in the biliary papillary area in association with a proliferation of highly convoluted tubular glands. The papillary lumen was narrowed, and an upstream dilation with bacterial proliferation was seen. The liver was initially free of lesions, and subsequently exhibited late lesions of cholestasis. Parasites were not found in the pancreatic duct, although pancreatitis was frequently observed. Oocysts were consistently present in the distal portion of the ileum. Both challenged and unchallenged immunosuppressed rats, exhibited widespread focal hepatic infarcts and pyelonephritis. Other organs appeared free of lesions. In addition to the intestine, data identified the biliary tract as a major site of C. parvum infection and as a potential protected reservoir which may sustain a chronic infection.

Animals↗
PubMed1995

Respiratory tract cryptosporidiosis in immunosuppressed rat is associated with an epithelial metaplasia.

Cryptosporidium parvum is an opportunistic protozoa that chronically infects the digestive tract of immunocompromised hosts. Respiratory cryptosporidiosis, which was reported in AIDS patients, is an uncommon feature of mammalian cryptosporidiosis models. In this study, we document the respiratory lesion; observed in an immunosuppressed rat model of cryptosporidiosis. Twenty rats were immunosuppressed with corticosteroids and low protein diet. They were challenged intratracheally with 10(6) C. parvum sporozoites. Lungs and ileums were examined on D3, D6, D10, D14. On D10 and D14, C. parvum were present in the respiratory tract of all animals in association with the progressive appearance of an immature malpighian metaplasia. On D14, an intestinal infection was also detected in 2/4 animals. The respiratory tract appears to be a fully permissive area for the protozoa in immunosuppressed rats. Introduction of parasites on the respiratory mucosa seems a requisite to induce respiratory cryptosporidiosis. This experimental protocol yields a low mortality rate, and so modelizes late and/or chronic stages of respiratory cryptosporidiosis.

Animals↗
PubMed1994

Human TcR gamma delta+ lymphocyte response on primary exposure to Plasmodium falciparum.

In 29 patients experiencing their first P. falciparum malarial attack, blood levels of TcR gamma delta+ lymphocytes were studied from the onset of infection to up to 6-9 months later. Blood TcR gamma delta+ lymphocytes, revealed using the TcR delta 1 monoclonal antibody (MoAb), were increased both in absolute and relative numbers. Alterations lasted for up to 3-4 months following the attack. A Ti gamma A/BB3 reactive V gamma 9 subset was preferentially amplified. In vitro, TcR gamma delta+ lymphocytes from both malaria-sensitized and unprimed donors responded to P. falciparum schizont extract (PFSE). PFSE-stimulated polyclonal T cell lines consisted principally in TcR gamma delta+ cells with a Ti gamma A+/BB3+ phenotype. Several TcR gamma delta+ T cell clones obtained from patients recovering from acute malarial attack were maintained in the presence of PFSE and autologous irradiated PBL. They belong to the V gamma 9 subset. In long-term cultures, TcR gamma delta+ clones progressively lost their capacity to react to PFSE antigen while they were able to proliferate and to exert cytotoxic activity in response to autologous TcR alpha beta+, PFSE-specific T lymphocyte clones. This suggests that regulatory interactions occur between activated TcR gamma delta+ and TcR alpha beta+ cells generated by P. falciparum. Sequential variations in blood TcR gamma delta+ and TcR alpha beta+ lymphocyte levels after primary exposure to P. falciparum suggest that such regulatory interactions may occur in vivo.

Acute Disease↗
PubMed1994

An immunosuppressed rat model for evaluation of anti-Cryptosporidium activity of sinefungin.

Cryptosporidium parvum causes life-threatening diarrhoea in immunocompromised, especially AIDS patients and the efficiency of proposed anti-cryptosporidial therapies is limited or doubtful. An immunosuppressed adult rat model of C. parvum infection was developed for screening molecules candidate for curative and preventive activity in human cryptosporidiosis. Among 31 drugs tested, lasalocid (2-10 mg/kg/24 h), and sinefungin (2-10 mg/kg/24 h), exhibited some activity against C. parvum infection. Oral sinefungin therapy resulted in a dose related suppression of oocysts shedding, which correlated with oocyst disappearance from ileum sections and was also efficient in preventing infection. Relapses were observed after discontinuation of curative sinefungin therapy, which suggests that the biliary tract, a major location and parasite reservoir which sustains persisting infection, was not cleared of parasites by the drug. Improved therapeutic procedures with sinefungin (or analogues) will result from current pharmacological studies.

Adenosine↗
PubMed1993

[Cell-mediated immunity and protection against blood stages of Plasmodium falciparum].

In recent years, cell-mediated immunity against malaria has been the subject of intensive investigation either in humans from malaria endemic areas, or experimental models. Cellular immune mechanisms have been regarded as secondary to humoral immunity but, there is increasing evidence that shows its critical role in protection against blood stage plasmodium parasites. In the context of a large humoral-cellular interaction, T helper lymphocytes and monocytes/macrophages may play a key role in the elimination of plasmodial blood stages, particularly P. falciparum. IL-2, IL-4, IL-5, IFN-gamma cytokines secreted principally by CD4+ T lymphocytes and oxygen and nitrogen radicals produced by activated macrophages, are involved in the control of plasmodial infection. The spleen also plays a very important function in the anti-malarial protection by its increased capacity for filtration/destruction of parasitized red blood cells and by induction of B and T memory lymphocytes. Successful vaccination against malaria needs a choice of plasmodial antigens or B and T immunodominants epitopes able to stimulate plasmodium-specific lymphocytes and functional modification in the spleen.

Antibodies, Protozoan↗
PubMed1993

Decreased blood TcR gamma delta+ lymphocytes in AIDS and p24-antigenemic HIV-1-infected patients.

The significance of blood TcR gamma delta+ lymphocyte level was evaluated in the context of immunodeficiency and infections in 209 HIV-1-infected patients. Blood TcR gamma delta+ lymphocyte values were found higher in patients belonging to the CDC group II/III than those in the CDC groups IV C1 and IV D (P < 0.001) and P < 0.01, respectively). TcR gamma delta+ lymphocyte counts were lower in patients with oral candidiasis (P < 0.01), and in association with pneumocystosis or toxoplasmosis (P < 0.001). In 81 patients with a detectable HIV-1 p24 antigenemia, TcR gamma delta+ lymphocyte counts were lower than those in nonantigenemic patients (P < 0.001). In the CDC II/III group, p24-antigenemic patients exhibited lower TcR gamma delta+ cell counts than those in patients without antigenemia (P = 0.06). Data suggest that depletion of the TcR gamma delta+ lymphocyte subset characterizes HIV-1-infected patients with oral candidiasis, pneumocystosis, toxoplasmosis, and/or HIV-1-antigenemia.

AIDS-Related Opportunistic Infections↗