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Biomedical subjects

J Grenier

Publications and source records attributed to J Grenier.

At least 73 records · Page 4Linked to original sources
PubMed1989

Detection of beta-1,3-glucanase activity after native polyacrylamide gel electrophoresis: application to tobacco pathogenesis-related proteins.

Beta-1,3-Glucanase (laminarinase) activity was detected after polyacrylamide gel electrophoresis under native conditions by using laminarin as substrate. Following incubation of gels, laminarin was stained with Aniline Blue. Under UV illumination, lysis zones appeared as dark bands against a fluorescent background. As low as 0.001 unit of commercial Penicillium laminarinase could be observed after incubating the polyacrylamide gel for 45 min at pH 5.0. Extracts of commercial Penicillium laminarinase exhibited four bands with lytic activity towards laminarin. Analysis of intercellular fluid extracts of tobacco mosaic virus-infected tobacco leaves revealed four beta-1,3-glucanases corresponding to three acidic pathogenesis-related proteins, b4 (2), b5 (N) and b6b (0), and one basic protein. The presence of laminarin in gels retarded the migration of some proteins with beta 1,3-glucanase activity. This change in electrophoretic mobility could be used as a complementary affinity test for identifying proteins with beta-1,3-glucanase activity.

Electrophoresis, Polyacrylamide Gel↗
PubMed1989

The defect in peripheral blood B-cell activation in patients with multiple myeloma is not due to a deficiency in the production of B-cell growth and differentiation factors.

The suppression of B lymphopoiesis is a major feature of multiple myeloma (MM). In this disease, there is a striking defect in the response of peripheral blood B cells to pokeweed mitogen (PWM). Normally, B-cell activation depends on B-cell growth factors (BCGFs) and B-cell differentiation factors (BCDFs), produced by peripheral blood mononuclear cells. We therefore evaluated whether the production of these cytokines was defective in patients with MM. We have studied the production of BCGFs (using the anti-mu assay) and, particularly, interleukin-2 and interferon-gamma, two well-documented BCGFs. No defect in the production of BCGFs, interleukin-2, and interferon-gamma was found in patients with active (N = 14) or stable (N = 10) MM, compared with healthy donors (N = 13). The production of BCDFs (i.e., overall activity) was also evaluated and, more particularly, that of interleukin-6 (IL-6). This cytokine is a potent BCDF which is essential in the PWM-induced activation of B cells, acting at the terminal stages of B-cell differentiation. Again, no defect in the production of BCDFs and IL-6 was found in patients with MM. Therefore, the ability to secrete cytokines controlling the process of B-cell activation is not affected in such patients. This indicates that the profound failure of humoral immune response is not due to deficiency of peripheral blood mononuclear cells producing these factors.

B-Lymphocytes↗
PubMed1989

[Quantitation of plasma 17-beta estradiol using an immunoenzyme method. Comparison with a specific radioimmunoassay].

Estradiol-17 beta (E2) was assayed on plasma samples with an enzyme immunoassay kit and results were compared with values obtained from a specific radioimmunoassay. An overall and specimen-dependent underestimation is found, confirmed by cold E2 recovery experiments. Such a kit is not entirely reliable in ovulation induction monitoring, specially for definition of hCG administration timing.

Chorionic Gonadotropin↗
PubMed1989

Lysozyme activity in animal extracts after sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

1. Lysozyme activity was detected after electrophoresis in sodium dodecyl sulfate-polyacrylamide gels containing 0.2% (W/V) autoclaved Micrococcus lysodeikticus cells as substrate. 2. Lysozyme activity appeared as clear lysis zones after incubation of opaque gels at 37 degrees C in buffered Triton X-100. 3. As low as 0.1 pg of purified hen egg white lysozyme could be detected after 16 hr incubation at pH 6.5. 4. Bands with lytic activity from kidney and pancreas acetone powders, bird's egg whites and vitelline membranes, animal sera and human saliva corresponded to c-type (Mr 14,500), g-type (Mr 20,500) or both lysozymes as far as molecular weight is concerned. 5. Some extracts, like porcine kidney, exhibited more than two bands. 6. Bands with lytic activity migrating at the level of g-type lysozymes were detected in some kidney and pancreas extracts.

Animals↗
PubMed1989

Immunogold localization of beta-1,3-glucanases in two plants infected by vascular wilt fungi.

An antiserum raised against a purified tobacco beta-1,3-glucanase (PR-N) was used to study the subcellular localization of enzyme in fungus-infected plant tissues by means of post-embedding immunogold labeling. In susceptible tomato plants, the enzyme accumulation was found to occur as a result of successful tissue colonization, whereas it appeared to be an early event associated with limited spread of the fungus in resistant tissues. Although marked differences between susceptible and resistant tomato cultivars were observed in the rate of production of beta-1,3-glucanase, the pattern of enzyme distribution was similar. The enzyme was found to accumulate predominantly in host cell walls and secondary thickenings of xylem vessels. By contrast, a very low amount of enzyme was associated with compound middle lamellae. The occurrence of beta-1,3-glucanase at the cell surface of invading fungi was an indication of their possible antifungal activity. A low enzyme concentration was detected in vacuoles of both healthy and infected tissues. In infected eggplant tissue, the pattern of beta-1,3-glucanase distribution was similar to that observed with tomato. Whether these hydrolases accumulate first in vacuoles and are subsequently conveyed toward the outside to participate in fungal wall lysis remains to be determined.

Antibody Specificity↗
PubMed1989

Substance P activation of bronchoalveolar macrophages from asthmatic patients and normal subjects.

The role of substance P in the pathogenesis of asthma is unclear. Animal studies suggest that it may be important, whereas human studies do not confirm this. Alveolar macrophages can be recovered easily by bronchoalveolar lavage (BAL) and stimulated in vitro. To assess the role of substance P in humans, we tested its ability to stimulate alveolar macrophages from six normal subjects and seven asthmatic patients. BAL cells were separated by adherence and alveolar macrophages constituted 95% of the adherent cell population. Four concentrations of substance P were used (10(-7), 10(-6), 10(-5), 10(-4) M). To assess the non-specific activation of alveolar macrophages we used three concentrations of lipopolysaccharides (LPS) (5, 10, 20 micrograms/ml). The stimulation of alveolar macrophages was assessed by the release of thromboxane B2 by radioimmunoassay. This study indicates that alveolar macrophages are stimulated by LPS but are poorly activated or not at all by substance P.

Adolescent↗
PubMed1989

[Thyroid function in normal aged subjects or with auricular fibrillation].

Free T4, free T3 and TSH before and 30 min after TRH administration have been evaluated in 35 elderly patients with atrial fibrillation (AF), in 35 elderly normal subjects (AN) and compared with results obtained in 36 young men (YN). No significant differences were evidenced between AF and AN, especially no mild hyperthyroidism was discovered in AF. In comparison with YN, there was no alteration of free T4 with age but free T3 is dramatically decreased; concerning TSH, there is a significant decrease before and after TRH in AN males whereas TSH levels in other subgroups are similar to those in YN.

Aged↗
PubMed1988

Production of B-cell growth factor interleukin 2 and gamma interferon by peripheral blood lymphocytes from patients with chronic lymphocytic leukemia of B-cell type.

Chronic lymphocytic leukemia of B-cell type (B-CLL) is a malignant disease characterized by monoclonal proliferation of small lymphocytes of B-cell origin, usually associated with suppression of polyclonal B-cell activation (i.e., proliferation and differentiation). Normal human B-cell proliferation is controlled by different T-cell-derived lymphokines, including interleukin 2 (IL2) and gamma interferon (gamma-IFN), that account for the majority of the B-cell growth factor (BCGF) activity produced by mitogen-activated peripheral blood mononuclear cells (PBMCs). We have previously shown an increased and dysregulated secretion of IL2 in peripheral blood from patients with B-CLL. BCGF, IL2, and gamma-IFN productions by phytohemagglutinin (PHA)-stimulated PBMCs were investigated in 13 patients with active untreated B-CLL and 11 healthy donors. B-CLL PBMCs produced a significant amount of BCGF (6 U/ml) despite the low percentage of T cells (10%) associated with this disease as compared with that found in healthy donors (61%). BCGF production in normal controls and B-CLL patients was tripled after irradiation of PBMCs or addition of indomethacin. gamma-IFN secretion in B-CLL patients was decreased when compared with normal controls. Therefore, when gamma-IFN was calculated per fixed number of T cells, production was significantly higher in B-CLL patients than in normal controls, showing a dilution of the productive cells. This study suggests that T cells from B-CLL patients are functional in terms of BCGF production despite their decreased percentage and abnormalities in surface markers.

Aged↗
PubMed1988

Regulation of plasma sex-steroid-binding protein in adult cynomolgus monkeys (Macaca fascicularis) during different reproductive states.

Levels of the sex-steroid binding protein (mSBP) have been characterized in Cynomolgus monkeys, during different stages of reproduction and under hormonal treatments, by an immunoassay allowing a specific and accurate measurement of the protein itself. Using an antiserum specific for native human SBP, we have determined the mSBP level by electroimmunodiffusion. This method correlates closely with the binding capacity measured by a steady-state polyacrylamide electrophoresis. The levels are lower in males (M = 88 +/- 8.6 nmoles/1, n = 6) than in females in the follicular phase (M = 123 +/- 4.4 nmoles/1, n = 5, p less than 0.001) and in castrated males (M = 172 +/- 13.3 nmoles/1, n = 3, p less than 0.001). During gestation, the SBP level decreases (M = 69 +/- 16.3 nmoles/1, n = 7, in the latter part of pregnancy), but during lactation, it is similar to follicular values. Estrogen treatment fails to increase SBP levels in castrated animals, but the values are reduced by testosterone treatment. Since these results are different from those observed in women, we question the validity of using monkeys as models for understanding the mechanisms controlling the concentration of SBP in human blood.

Animals↗
PubMed1988

Platelet serotonin content and plasma tryptophan in peri- and postmenopausal women: variations with plasma oestrogen levels and depressive symptoms.

Platelet serotonin content was measured by high pressure liquid chromatography in 56 peri- and postmenopausal women, in order to study variations of this parameter with hormonal status and depressive mood symptoms. Clinical symptoms were assessed by a self-report depression symptom scale (CES-D of NIMH). Thirty-eight women with a score of 16 or more were considered as presenting depressive symptoms (mean score +/- SD = 28.8 +/- 10.5), while the others formed the control group (n = 18, score = 4.4 +/- 4.2). Platelet serotonin contents were significantly lower in the 'depressed' group (0.302 +/- 0.010 vs. 0.366 +/- 0.020 nmol 10(-8) platelets, means + SEM, P less than 0.001 by Mann-Whitney U-test). In 'depressed' women who had been treated for one or more depressive episodes, platelet 5-HT contents (0.283 +/- 0.023, n = 18, P less than 0.01) were significantly lower with respect to controls. In patients without previous episodes of depression, serotonin expressed in nmol 10(-8) platelets did not differ significantly from controls but serotonin expressed in nmol ml-1 of blood was slightly lower than control values (0.890 +/- 0.085, n = 20 vs. 1.088 +/- 0.090 nmol ml-1, n = 18, P less than 0.02). Platelet serotonin content was positively correlated to plasma oestrone and oestradiol concentrations among the control group but not in the 'depressed' group.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Platelets↗
PubMed1988

In vitro production of beta 2 microglobulin by human myeloma cells.

Serum beta 2 microglobulin (B2M) has recently been shown to be a powerful, although nonspecific, marker of multiple myeloma (MM) disease activity. Since the nature of cells producing high levels of B2M remains obscure in MM, we measured (in vitro) the spontaneous secretion of free B2M in 58 culture samples from 52 patients with MM. In comparison with samples from normal individuals and from individuals with monoclonal gammopathy of unknown significance, an abnormal secretion of B2M was found in 83% of samples containing myeloma cells. Levels of secretion significantly correlated with the percentage of tumor cells, tumor progression, and moreover, with the immunoglobulin type of the tumor. The highest levels of secretion were noted in IgG and IgA MM. Our present results would favor the hypothesis of a direct secretion of B2M by myeloma cells and emphasize the interest of B2M as a marker in a majority of (but not all) patients with MM.

Biomarkers, Tumor↗
PubMed1987

The antiprogestin RU486 in advanced breast cancer: preliminary clinical trial.

Twenty-two oophorectomized or postmenopausal women with metastatic breast cancer resistant to several medical therapies (tamoxifen, or other endocrine therapy, and chemotherapy) were treated in a first trial with 200 mg per day of RU486 for 1 to 3 months. The long-term tolerance was good but there was a moderate decrease in plasma potassium. Plasma cortisol was increased 2-fold without clinical hypo- or hypercorticism. Twelve patients had a partial response or a stabilization of secondary deposits for 6 weeks but the response rate at 3 months was 18%. When available, estrogen and progesterone receptor levels were positive in these patients. This preliminary trial shows for the first time that the antiprogestin RU486 is well tolerated for medium term treatment. It suggests that it might be active on advanced breast cancer becoming resistant to tamoxifen.

Breast Neoplasms↗
PubMed1987

Variations of growth factors in pregnant women during labor and in newborns at delivery.

To study physiological variations in serum growth factors during peripartal period, we have measured levels of a serum growth-promoting activity (thymidine activity, TA) and radioimmunoassayable somatomedin C (Sm-C) during labor in 39 women who delivered spontaneously (group A), by caesarean section (group B) and by legal abortion (LA) (group C). TA values were higher in the group A than in the group B and C, suggesting an important effect of uterine contractions in TA generation. A major role in Sm-C production seems to be played by the length of gestation since Sm-C concentrations were significantly higher in mothers delivered by caesarean section than in LA women. During labor influence of estrogens and progesterone in growth factor production seems unlikely because of the lack of correlation with TA and Sm-C levels. The lower TA values in placental flow than in the capillary blood of newborn suggest that serum growth factors, measured as TA, are produced by the newborn and do not cross through the placenta. These data suggest that the absolute dependence of the fetus on the mother does not preclude instances of fetal autonomy.

Abortion, Legal↗
PubMed1986

[Role of the assay of serum beta 2 microglobulin in the clinical evaluation of myeloma].

The survival of individual patients with multiple myeloma ranging from a few weeks to several years, careful pretreatment evaluation of prognostic factors is extremely important. Several methods of stratification are available, but in spite of their validity they present a number of problems, particularly with regard to their inter-reproducibility. In addition, they are of no help to evaluate response to chemotherapy, quality of remission, plateau phase or kinetics of relapse. Recent studies have clearly demonstrated that serum beta-2 microglobulin, as a single variable, is the best individual determinant as a prognostic marker in multiple myeloma. Using this assay and serum albumin as prognostic determinants, a simple stratification, superior to the three previously available methods, was developed. Serum beta-2 microglobulin is a very useful marker in the follow-up of most multiple myeloma patients. It appears to be a key measurement for assessing the prognosis and response to treatment of these patients.

Humans↗
PubMed1986

Prognostic factors and staging in multiple myeloma: a reappraisal.

To assess the important factors in the prognosis and staging of multiple myeloma (MM), we have correlated the presenting clinical features of 147 previously untreated patients with MM with the survival duration using multiple regression analyses. We have included the three major available myeloma-staging systems (MSS), ie, Durie-Salmon (DS), Medical Research Council (MRC), and Merlini-Waldenström-Jayakar (MWJ), plus two new variables related to disease activity: the serum beta 2-microglobulin level (S beta 2M) and the instantaneous rate of bone resorption. Our study confirms the validity of the three MSS in the prediction of survival duration, with a slight but significant advantage for the DS MSS. Among single variables, S beta 2M was the most powerful indicator of prognosis (P less than .0001), serum albumin level being the only variable adding to this significantly (P = .02). Of major interest, S beta 2M alone was a better indicator than MRC and MWJMSS. Finally, S beta 2M and the serum albumin level, variables not included in the three MSS, were better indicators than the classical DS MSS and could be combined simply to give a very powerful system of stratification.

Calcium↗
PubMed1986

[Not Available].

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France↗