Bayesian Regression Quantifies Uncertainty of Binding Parameters from Isothermal Titration Calorimetry More Accurately Than Error Propagation.

We compare several different methods to quantify the uncertainty of binding parameters estimated from isothermal titration calorimetry data: the asymptotic standard error from maximum likelihood estimation, error propagation based on a first-order Taylor series expansion, and the Bayesian credible interval. When the methods are applied to simulated experiments and to measurements of Mg(II) binding to EDTA, the asymptotic standard error underestimates the uncertainty in the free energy and enthalpy of binding. Error propagation overestimates the uncertainty for both quantities, except in the simulations, where it underestimates the uncertainty of enthalpy for confidence intervals less than 70%. In both datasets, Bayesian credible intervals are much closer to observed confidence intervals.

The rate of transmission possibility of KPC and NDM-1 producing Klebsiella pneumoniae in ICU: the need for strengthened infection control measures.

OBJECTIVE: This study aims to characterize the rate of two specific resistance genes (KPC and NDM-1) and determine the route of transmission between the sites to implement infection control measures effectively. PATIENTS AND METHODS: This study was carried out at Viet Duc hospital in Vietnam. Bacterial isolates (Klebsiella pneumoniae) were collected between January 2018 and June 2019. Bacterial strains and antimicrobial susceptibility testing were performed in the VITEK 2 system. RESULTS: A total of 100 samples from 25 patients were taken. From each patient, we collected 4 samples from 4 sites. 25 isolated strains resisted 100% to amoxicillin/acid clavulanic, piperacillin/Tazobactam, and antibiotics in the cephalosporine group. Particularly in the carbapenem group, they resisted 100% to ertapenem, 96% to imipenem, and eropenem (rest was intermediate level). They have 76% sensitivity to aminoglycosides, 76% to amikacin, 60% to gentamycin, and 60% to tigecycline. Klebsiella pneumoniae carbapenemase (KPC) (+) was 24% and NDM-1 (+) was 28%. There was no case in all four sites. Positive-KPC strains were mainly in two sites (4/6 = 66.67%) and positive-NDM-1 strains were mainly in three sites (4/7 = 57.14%). Negative to both KPC and NDM-1 strains were in one site (4/12 = 33.3%) and two sites (6/12 = 50%). CONCLUSIONS: The rate of KPC and NDM-1 was 24% and 28%. In accordance with high antibiotic resistance rates to common antibiotics used in Vietnam, the high rate of transmission possibility between the sites contributed to strengthen the implementation of infection control measures in the ICU setting.

Bayesian regression and model selection for isothermal titration calorimetry with enantiomeric mixtures.

Bayesian regression is performed to infer parameters of thermodynamic binding models from isothermal titration calorimetry measurements in which the titrant is an enantiomeric mixture. For some measurements the posterior density is multimodal, indicating that additional data with a different protocol are required to uniquely determine the parameters. Models of increasing complexity-two-component binding, racemic mixture, and enantiomeric mixture-are compared using model selection criteria. To precisely estimate one of these criteria, the Bayes factor, a variation of bridge sampling is developed.

[Feasibility and security of laparoscopic (± robotic) total hysterectomy in outpatient surgery: A French multicenter retrospective study]. / Faisabilité et sécurité de l'hystérectomie totale par voie cœlioscopique (± robot assisté) en chirurgie ambulatoire : une étude rétrospective multicentrique française.

OBJECTIVE: To assess the feasibility and safety of total hysterectomy by laparoscopic approach (± robot assisted) in ambulatory. MATERIALS AND METHODS: French three-center retrospective study including 165 patients who had laparoscopic (± robot assisted) total hysterectomy scheduled as outpatients from January 2016 to December 2020. Clinical and perioperative data were collected. Factors associated with outpatient failure and rehospitalization were evaluated. RESULTS: The outpatient success rate was 92.7%. Factors associated with outpatient failure were incision time>13:00, large volume of blood loss, intraoperative complications with Oslo score≥2, uterine weight≥250g, indication for benign pathology, and robot-assisted approach. Among patients managed as outpatients, 7.2% were rehospitalized at a mean of 10 days from surgery. The factors associated with rehospitalization were the use of an effective antiaggregant or anticoagulant treatment and the use of intraoperative adhesiolysis. Four patients (2.6%) underwent revision surgery. CONCLUSION: Minimally invasive hysterectomy can be performed as an outpatient procedure even in cases of malignant pathology. Age and body mass index are not associated with an increased risk of failure or re-hospitalization within one month.

[Sentinel lymph node biopsy in the management of early-stage ovarian cancer: A systematic review of the literature]. / Place du ganglion sentinelle dans la prise en charge du cancer de l'ovaire de stade précoce : revue de la littérature.

The initial management of early-stage ovarian cancer consists of staging surgery including pelvic and para-aortic lymphadenectomy. The use of the sentinel lymph node (SLN) procedure in this setting may decrease the morbidity associated with this surgery. The objective of this review was to evaluate the feasibility of the SLN procedure in ovarian cancer diagnosed at an early stage by comparing the different techniques used and their accuracy. A systematic literature search was performed on PubMed and ClinicalTrials.gov for articles in English or French about the SLN technique in ovarian cancer. Ten studies were included in the analysis, with a total of 179 patients. The main tracers used were Technetium-99m, indocyanine green, and patent blue, and the most common site of injection was the proper ovarian and unfundibulopelvic ligaments. The overall detection rate was 87.7%. Of the small number of cases of lymph node metastasis reported, the SLN procedure had a sensitivity of 90.9% and a negative predictive value of 98.8%. The sentinel node procedure appears to be feasible and safe and could be reliable in determining the lymph node status of patients with early-stage ovarian cancer.

Fish-borne trematode metacercariae detected in fish commonly used for raw consumption in Ninh Binh Province, Vietnam.

Raw or undercooked fish dishes are the major sources of human infection of fishborne trematodes (FBT) and the situation of metacercarial infection in fish greatly affect the prevalence in humans, especially those fish that are commonly used for raw consumption. To investigate the situation of infection with metacercaria of FBT in fish often used to prepare raw fish dishes by local people to assess the risk of infection to humans in Ninh Binh province, Vietnam. 345 fish belonging to five species of freshwater and one species of brackish water fish were collected from fishermen or small-scale fish dealers in Kim Son and Yen Khanh districts, Ninh Binh province between May 2017 and May 2018. Metacercaria of FBT was discovered by pepsin and hydrochloric acid digestion techniques and identified by the morphological and molecular analysis. Among examined fish, 44.06% infected with FBT metacercaria and the highest prevalence was in Cyprinus carpio (86.54%), Ctenopharyngodon idellus (78.43%) and Hypophthalmichthys molitrix (66.67%) while Konosirus punctatus - the brackish water fish - were free from infection. Three species of FBT were found; namely Haplorchis pumilio (accounting for 99.84% of collected metacercariae), Haplorchis taichui and Clonorchis sinensis. The average density was 1.06 metacercariae per gram of freshwater fish and the highest number was of C. idellus (6.38 cysts/gram) followed by Cirrhinus molitorella and C. carpio. Results of the study show the high prevalence of infection of FBT metacercariae among freshwater fish often used to prepare raw fish dishes in Ninh Binh province. These findings suggest the need for greater awareness of the risk from raw fish dishes among public health authorities and people.

Fish-borne trematode metacercariae detected in fish commonly used for raw consumption in Ninh Binh Province, Vietnam

@#Raw or undercooked fish dishes are the major sources of human infection of fishborne trematodes (FBT) and the situation of metacercarial infection in fish greatly affect the prevalence in humans, especially those fish that are commonly used for raw consumption. To investigate the situation of infection with metacercaria of FBT in fish often used to prepare raw fish dishes by local people to assess the risk of infection to humans in Ninh Binh province, Vietnam. 345 fish belonging to five species of freshwater and one species of brackish water fish were collected from fishermen or small-scale fish dealers in Kim Son and Yen Khanh districts, Ninh Binh province between May 2017 and May 2018. Metacercaria of FBT was discovered by pepsin and hydrochloric acid digestion techniques and identified by the morphological and molecular analysis. Among examined fish, 44.06% infected with FBT metacercaria and the highest prevalence was in Cyprinus carpio (86.54%), Ctenopharyngodon idellus (78.43%) and Hypophthalmichthys molitrix (66.67%) while Konosirus punctatus – the brackish water fish – were free from infection. Three species of FBT were found; namely Haplorchis pumilio (accounting for 99.84% of collected metacercariae), Haplorchis taichui and Clonorchis sinensis. The average density was 1.06 metacercariae per gram of freshwater fish and the highest number was of C. idellus (6.38 cysts/gram) followed by Cirrhinus molitorella and C. carpio. Results of the study show the high prevalence of infection of FBT metacercariae among freshwater fish often used to prepare raw fish dishes in Ninh Binh province. These findings suggest the need for greater awareness of the risk from raw fish dishes among public health authorities and people.

CuO and CeO2-doped catalytic material synthesized from red mud and rice husk ash for p-xylene deep oxidation.

CuO-CeO2 catalysts supported on material synthesized from red mud and rice husk ash (CuO-CeO2/ZRM) were prepared by co-impregnation method. The role of CeO2 additive in the improvement of physicochemical properties and catalytic activity of CuO-CeO2/ZRM catalysts were emphasized. Several techniques, including Brunauer-Emmett-Teller Nitrogen physisorption measurements, X-ray powder diffraction, hydrogen temperature programed reduction, scanning electron microscopy and transmission electron microscopy (TEM) were used to investigate the properties of catalysts. Crystallite size calculated by Scherrer' equation was 17.4 - 21.8 nm. Modification of 5 wt% CuO/ZRM catalyst with CeO2 had reduced the size of the nanoparticles leading to a significant enhancement of the catalytic activity in p-xylene deep oxidation at temperature range of 275 - 400 °C. The 5 wt% CuO/ZRM sample promoted by 3 wt% of nanoparticle CeO2 with the average size of 17.5 nm and BET surface area of 31.3 m2 g-1 exhibited the best activity for p-xylene deep oxidation. In this sample, the conversion of p-xylene reaches to 90% at 350 °C.

OsABCG9 Is an Important ABC Transporter of Cuticular Wax Deposition in Rice.

The importance of the cuticular layer in regulating a plant's water status and providing protection from environmental challenges has been recognized for a long time. The cuticular layer in plants restricts non-stomatal water loss and protects plants against damage from pathogen infection and UV radiation. Much genetic and biochemical research has been done about cutin and wax transportation in Arabidopsis thaliana, but little is known about it in rice. Here, we report that a rice ATP-binding cassette (ABC) transporter, OsABCG9, is essential for normal development during vegetative growth and could play a critical role in the transportation of epicuticular wax in rice. Rice phenotypes with mutated OsABCG9 exhibited growth retardation and sensitivity to low humidity. The total amount of cuticular wax on the leaves of the osabcg9-1 mutant diminished by 53% compared with the wild type, and wax crystals disappeared completely in osabcg9-2 mutant leaves. However, OsABCG9 does not seem to be involved in cutin transportation, even though its ortholog in Arabidopsis, AtABCG11, transports both wax and cutin. Furthermore, the osabcg9-1 mutant had increased leaf chlorophyll leaching and more severe drought susceptibility. This study provides new insights about differences between rice and A. thaliana in wax and cutin transportation associated with the ABCG family during evolution.

A Systematic View of the MLO Family in Rice Suggests Their Novel Roles in Morphological Development, Diurnal Responses, the Light-Signaling Pathway, and Various Stress Responses.

The Mildew resistance Locus O (MLO) family is unique to plants, containing genes that were initially identified as a susceptibility factor to powdery mildew pathogens. However, little is known about the roles and functional diversity of this family in rice, a model crop plant. The rice genome has 12 potential MLO family members. To achieve systematic functional assignments, we performed a phylogenomic analysis by integrating meta-expression data obtained from public sources of microarray data and real-time expression data into a phylogenic tree. Subsequently, we identified 12 MLO genes with various tissue-preferred patterns, including leaf, root, pollen, and ubiquitous expression. This suggested their functional diversity for morphological agronomic traits. We also used these integrated transcriptome data within a phylogenetic context to estimate the functional redundancy or specificity among OsMLO family members. Here, OsMLO12 showed preferential expression in mature pollen; OsMLO4, in the root tips; OsMLO10, throughout the roots except at the tips; and OsMLO8, expression preferential to the leaves and trinucleate pollen. Of particular interest to us was the diurnal expression of OsMLO1, OsMLO3, and OsMLO8, which indicated that they are potentially significant in responses to environmental changes. In osdxr mutants that show defects in the light response, OsMLO1, OsMLO3, OsMLO8, and four calmodulin genes were down-regulated. This finding provides insight into the novel functions of MLO proteins associated with the light-responsive methylerythritol 4-phosphate pathway. In addition, abiotic stress meta-expression data and real-time expression analysis implied that four and five MLO genes in rice are associated with responses to heat and cold stress, respectively. Upregulation of OsMLO3 by Magnaporthe oryzae infection further suggested that this gene participates in the response to pathogens. Our analysis has produced fundamental information that will enhance future studies of the diverse developmental or physiological phenomena mediated by the MLO family in this model plant system.

Adhesion of B-Cell Chronic Lymphocytic Leukemia Cells to Marrow Stromal Cells is Mediated by α4ß1 but not ß2αL Integrin: MSC also Prevent Apoptosis of B-CLL Cells.

Interactions between MSC and B-CLL cells were investigated to better understand the role of adhesion proteins in the biology of B-CLL. The role of ß1 and ß2 integrins and CD44 in adherence of B-chronic lymphocytic leukemia (CLL) cells to bone marrow stromal cell (MSC) monolayers and the ability of MSC to prevent apoptosis of CLL cells was investigated. Peripheral blood mononuclear cells, from 8 patients with CD5-positive B-CLL, were effectively depleted of CD3-positive cells with an immunomagnetic column. Purity of B-CLL cells, as judged by coexpression of CD19 and CD5 on two-color fluor-ocytometry, was 92±4% (mean±SD) (n = 8). (51)Cr-labelled B-CLL cells, were incubated with isotype murine monoclonal antibodies or blocking MoAb's against the following adhesion proteins: integrins ß1, α4, and αL (chain of LFA-1), CD44 and CD106 (VCAM-1). The B-CLL cell adherence to marrow stromal cell (MSC) monolayers at 2hrs was 29±12% (mean±1SD). MoAb's against CD106, α4, and ß1 caused a significant inhibition of heterotypic adherence in 2/8, 3/8 and 4/8 experiments. Despite universal expression of αL on B-CLL cells, MoAb against αL did not influence adhesion of B-CLL cells in any of the eight experiments. MoAb's against CD44 caused an increase in B-CLL cell adherence to MSC in 1/8 experiments. No correlation between basal adhesion and intensity of α4 expression was noted. The absence of this correlation can be explained by the highly variable expression of α4 on the B-CLL cells from a limited number of patients. Notably, the intensity of α4 and ß1 expression, on the B-CLL cells correlated with the degree of inhibition by anti-α4 and anti-ß1 MoAb. A significant positive correlation was noted between baseline adhesion and intensity of ß1 expression. Thus, α4ß1 and its ligand VCAM-1 are important for adhesion of B-CLL cells to MSC. However, other ligands of α4 and other as yet undescribed adhesion proteins may also play a role in B-CLL cell adhesion to MSC. In addition, when B-CLL cells were cocultured in direct contact with MSC monolayers, the proportion of B-CLL cells undergoing apoptosis decreased significantly.

Elevated expression of hepatic proliferative markers during early hepatocarcinogenesis in hepatitis-B virus transgenic mice lacking mdr1a-encoded P-glycoprotein.

Recent studies have shown that expression levels of the multidrug resistance gene MDR1, which encodes the drug transporter P-glycoprotein, correlate with prognostic outcomes of certain tumor types. These findings suggest that expression of MDR1 may affect tumor behaviors. To address this issue further, we investigated the expression of mdr1a, a human MDR1 homolog, on the development of hepatocellular carcinoma in a transgenic mouse model carrying the liver-targeted expression of human hepatitis-B virus (HBV) surface antigen. The pathogenetic program was compared in HBV mice carrying either mdr1a(+/+) or mdr1a(-/-). We found that the expressions of proliferative activity markers, Ki67 nuclear antigen, and proliferating cell nuclear antigen were elevated in mdr1a(-/-) mice younger than 10 wk in comparison with those in the same age group of wild-type animals. Replication in the hepatic population as determined by bromodeoxyuridine incorporation tended to support observation that mdr1a(-/-) mice exhibited elevated labeling indices in this age group. Moreover, histologic staining and flow-cytometric analysis showed that the mdr1a(-/-) animals exhibited a higher cell population with polyploidy than did the mdr1a(+/+) counterparts of the same age. However, no significant differences in the expression of the liver-injury markers serum alanine transaminase and aspartate transaminase were observed. Although our results showed that absence of mdr1a expression is correlated with modest enhanced proliferative characteristics in the livers at stage before the development of hepatocellular carcinoma, the overall life spans between these two strains of mice were not significantly different. The implication of these findings to the role of P-glycoprotein in tumor development and cancer chemotherapy is discussed.

The situation of malaria along the Vietnam-Lao PDR border and some related factors.

This was a descriptive cross sectional study. It was done in 4 communes along the Vietnam-Lao PDR border of two mountainous provinces: Sonla and Nghean. The cluster multistage sampling technique was applied to choose the study sites. The results of the study show: Among the 2,441 persons given blood tests to find malaria parasites, 0.7% of them carry malaria parasite, of whom 0.6% carry P. falciparum and 0.1% carry P. vivax. The malaria morbidity in the year was 6.9%. The mortality due to malaria is 1.59 per 100,000 population per year. Among the 106 hamlet motivators being interviewed, only 75.5% knew that malaria is transmitted by mosquitos, 71.7% knew that malaria patients are a source of transmission, over 50% of the motivators have mistaken understanding about the living environment of malaria mosquitos. Most of them have had mistakes in diagnosis, treatment of malaria, mosquito-killing spraying. Among the 729 adults being interviewed, 59.0% did not know about the causes of malaria, 30.7% did not take part in malaria control activities. Only 69.3% of the adults regularly sleep inside mosquito nets, 68% of adults buy medicine to cure malaria, 39.9% referred patients to health facilities for cure, and 25% use forest herbs to cure malaria. The factors that increased the malaria morbidity in communes along Vietnam-Lao PDR border have been identified.

Silymarin suppresses TNF-induced activation of NF-kappa B, c-Jun N-terminal kinase, and apoptosis.

Silymarin is a polyphenolic flavonoid derived from milk thistle (Silybum marianum) that has anti-inflammatory, cytoprotective, and anticarcinogenic effects. How silymarin produces these effects is not understood, but it may involve suppression of NF-kappa B, a nuclear transcription factor, which regulates the expression of various genes involved in inflammation, cytoprotection, and carcinogenesis. In this report, we investigated the effect of silymarin on NF-kappa B activation induced by various inflammatory agents. Silymarin blocked TNF-induced activation of NF-kappa B in a dose- and time-dependent manner. This effect was mediated through inhibition of phosphorylation and degradation of Iota kappa B alpha, an inhibitor of NF-kappa B. Silymarin blocked the translocation of p65 to the nucleus without affecting its ability to bind to the DNA. NF-kappa B-dependent reporter gene transcription was also suppressed by silymarin. Silymarin also blocked NF-kappa B activation induced by phorbol ester, LPS, okadaic acid, and ceramide, whereas H2O2-induced NF-kappa B activation was not significantly affected. The effects of silymarin on NF-kappa B activation were specific, as AP-1 activation was unaffected. Silymarin also inhibited the TNF-induced activation of mitogen-activated protein kinase kinase and c-Jun N-terminal kinase and abrogated TNF-induced cytotoxicity and caspase activation. Silymarin suppressed the TNF-induced production of reactive oxygen intermediates and lipid peroxidation. Overall, the inhibition of activation of NF-kappa B and the kinases may provide in part the molecular basis for the anticarcinogenic and anti-inflammatory effects of silymarin, and its effects on caspases may explain its role in cytoprotection.

Tetanus antibodies measured by the toxin binding inhibition test (ToBI) in mothers and children in the Neonatal Tetanus Program in Vietnam.

The immunoresponse to vaccination in the Neonatal Tetanus Program (NNT) for pregnant women was studied in Vietnam using the Toxin Binding Inhibition Test (ToBI). The vaccination schedule consisted of two primary doses of adsorbed tetanus toxoid (TT) vaccine given with a one month interval. The seroconversion rate in the women was 98%. Two and a half months after birth, 63% of the children born from these women had tetanus antibody values higher than 0.01 IU/ml. Four women who had anti-tetanus titres < 0.01 IU/ml at delivery, despite two doses of primary vaccination, received a third booster with vaccine one year after the first injection. Their antibody levels were well above 0.01 IU/ml one month after this additional booster, suggesting that (when economically feasible) a third TT injection could be considered into the NNT to confer optimal anti-tetanus antibody levels in women for subsequent pregnancies. This study confirmed the effectiveness of the TT vaccines investigated and indicates their potential to replace, in immunosurveillance studies under field conditions, the in vivo mouse neutralisation test by in vitro alternative methods such as the ToBI test.

Structural analysis of the C-CAM1 molecule for its tumor suppression function in human prostate cancer.

BACKGROUND: Recently, we demonstrated that expression of C-CAM1, an immunoglobulin (Ig)-like cell adhesion molecule (CAM), was diminished in both prostate intraepithelial neoplasia and cancer lesions, indicating that loss of C-CAM1 expression may be involved in the early events of prostate carcinogenesis. Also, increased C-CAM1 expression can effectively inhibit the growth of prostate cancer. Structurally, C-CAM1 represents a unique CAM with a potential signal transducing capability. In this study, we further analyzed the functional domain of C-CAM1 for controlling its tumor suppression function. METHODS: Recombinant adenoviruses expressing a series of C-CAM1 mutants were generated, such as AdCAMF488 (mutated C-CAM1 containing Tyr-488 --> Phe-488), AdCAMH458 (intracellular domain deletion mutant containing 458 amino acids), AdCAMG454 (intracellular domain deletion mutant containing 454 amino acids), and AdCAMDeltaD1(C-CAM1 mutant containing first Ig domain deletion). After in vitro characterization of each virus, human prostate cancer cells infected with these viruses were subcutaneously injected into athymic mouse. Both tumor incidence and volume were measured for determining the tumor suppression function for each mutant. RESULTS: In vivo tumorigenic assay indicated that AdCAMDeltaD1 without cell adhesion function still retained its tumor suppression activity. In contrast, both AdCAMH458 and AdCAMG454 decreased or lost their tumor suppression activity. CONCLUSIONS: Our data indicate that the intracellular domain of the C-CAM1 molecule is critical for inhibiting the growth of prostate cancer, suggesting that C-CAM1 interactive protein(s) may dictate prostate carcinogenesis.

Quantitation of minimal residual disease in acute myelogenous leukemia and myelodysplastic syndromes in complete remission by molecular cytogenetics of progenitor cells.

Detection of karyotypic clonal abnormalities are prognostically useful in patients with acute myelogenous leukemia (AML) and myelodysplastic syndromes (MDS), but cytogenetic methods are not sensitive enough to detect low numbers of residual leukemic cells in patients who have achieved complete remission (CR). Fluorescence in situ hybridization (FISH) and fluorescence activated cell sorting (FACS) were used to investigate the frequency and presence of minimal residual disease (MRD) in AML and MDS patients (n = 28) with monosomy of chromosomes 7, 17 and 18 and trisomy of chromosomes 6, 8, 9 and 10 in CR. MRD was detected in all patients with monosomy 7 (n = 10) and followed by relapse in eight patients after 4.8 +/- 3.1 months. In contrast, persistent leukemic cells occurred in 11/12 patients with trisomy 8, but only three of them relapsed after 7.7 +/- 4.0 months. Cox regression analysis showed that cytogenetic class and levels of clonal cells at CR were related to time to relapse (P = 0.001). The level of MRD identified patients at high and low risk of relapse. High absolute levels of proliferating residual leukemic cells correlated with monosomy 7 and high risk of relapse.

Expression of multidrug resistance protein/GS-X pump and gamma-glutamylcysteine synthetase genes is regulated by oxidative stress.

Expression of the MRP1 gene encoding the GS-X pump and of the gamma-GCSh gene encoding the heavy (catalytic) subunit of the gamma-glutamylcysteine synthetase is frequently elevated in many drug-resistant cell lines and can be co-induced by many cytotoxic agents. However, mechanisms that regulate the expression of these genes remain to be elucidated. We report here that like gamma-GCSh, the expression of MRP1 can be induced in cultured cells treated with pro-oxidants such as tert-butylhydroquinone, 2,3-dimethoxy-1, 4-naphthoquinone, and menadione. Intracellular reactive oxygen intermediate (ROI) levels were increased in hepatoma cells treated with tert-butylhydroquinone for 2 h as measured by flow cytometry using an ROI-specific probe, dihydrorhodamine 123. Elevated GSH levels in stably gamma-GCSh-transfected cell lines down-regulated endogenous MRP1 and gamma-GCSh expression. ROI levels in these transfected cells were lower than those in the untransfected control. In the cell lines in which depleting cellular GSH pools did not affect the expression of the MRP1 and gamma-GCSh genes, only minor increased intracellular levels of ROIs were observed. These results suggest that intracellular ROI levels play an important role in the regulation of MRP1 and gamma-GCSh expression. Our data also suggest that elevated intracellular GSH levels not only facilitate substrate transport by the MRP1/GS-X pump as previously demonstrated, but also suppress MRP1 and gamma-GCSh expression.

Minimal residual disease in acute myelogenous leukaemia and myelodysplastic syndromes: a follow-up of patients in clinical remission.

The majority of patients with acute myelogenous leukaemia (AML) and myelodysplastic syndromes (MDS) relapse, especially those with unfavourable cytogenetics. This study was designed to investigate the presence and frequency of minimal residual disease (MRD) in patients with AML or MDS (n=35) and numerical abnormalities of chromosomes 6, 7, 8, 9, 10, 17 and 18 in clinical remission by using a combination of fluorescence activated cell sorting (FACS), fluorescence in-situ hybridization (FISH) and labelling with bromodeoxyuridine (BUdR). The technique enables the detection of as few as three leukaemic cells in 10(5) normal cells. MRD was detected in 33/35 patients in complete remission (CR). 16 patients relapsed (8/11 with monosomy 7, 4/17 with trisomy 8, and 4/7 with other cytogenetic abnormalities) after a median of 4.8 months (range 3-13). Levels of MRD (P=0.007) and proliferation index (P=0.011) were significantly higher in patients with monosomy 7 than in patients with trisomy 8 or other cytogenetic abnormalities. The percentage of cells in S-phase, the number of abnormal cells and cytogenetic class were related to time to relapse (P=0.001) with S-phase being the single most important prognostic factor (P=0.0001). We conclude that the combination of FACS/FISH/BUdR, which determines the number, phenotype and proliferation rate of very rare leukaemic cells in patients with AML or MDS in clinical remission, provides information that is useful in the identification of patients with high and low likelihood of relapse.

During development, 17alpha-estradiol is a potent estrogen and carcinogen.

Neonatal administration of estradiol-17beta (E2-17beta) increases the nuclear DNA content in the mouse reproductive tract. Similar responses have been demonstrated for synthetic estrogens such as diethylstilbestrol. One of the questions raised regarding environmental estrogens such as organochlorines is whether they are potent enough to result in abnormal changes such as those demonstrated by both natural and synthetic estrogens. To test this hypothesis, female BALB/c mice were treated neonatally (days 1-5) with either E2-17beta or estradiol-17alpha (E2-17alpha), an inactive stereoisomer in adult reproductive tissues. We also proposed whether neonatal administration of (E2-17alpha) was tumorigenic and whether the effects were age dependent. To answer these questions, one set each of 10 day-old treated and control mice received short-term secondary administration of E2-17beta, E2-17alpha, or cholesterol. Cervicovaginal tracts from intact BALB/c mice were examined histologically and by flow cytometry at 70 days of age and by histology alone at 18 to 22 months of age. The results include several important findings: a) like E2-17beta, neonatal E2-17alpha treatment induced persistent vaginal cornification, hypospadias, vaginal concretions, and hyperproliferation in nearly 100% of the animals regardless of the secondary treatment for most groups; b) neonatal E2-17alpha treatment increased the nuclear DNA content of cervicovaginal epithelium at one-half both the level (mean DNA index of 1.02 vs 1.04) and incidence (22 vs 46% of the animals) of E2-17beta; c) short-term secondary treatment with E2-17alpha, unlike E2-17beta, did not significantly augment the increase in DNA content (13% for E2-17alpha vs 37 and 56% for control and E2-17beta, respectively); and d) neonatal administration with E2-17alpha induced adenosquamous tumors in the reproductive tract in 25% of the animals. Therefore, the biological effects (estrogenic potency) of E2-17alpha may be age dependent.