Picropodophyllin induces downregulation of the insulin-like growth factor 1 receptor: potential mechanistic involvement of Mdm2 and β-arrestin1

The insulin-like growth factor 1 receptor (IGF-1R) is crucial for growth and survival of malignant cells. Experience in targeting IGF-1R in cancer models has shown that strategies promoting downregulation of the receptor are much more efficient in inducing apoptosis than those inhibiting the IGF-1R activity. Recently, we found that the cyclolignan picropodophyllin (PPP) inhibits phosphorylation of IGF-1R and activation of downstream signaling without interfering with the highly homologous insulin receptor (IR). Furthermore, PPP treatment caused strong regression of tumor grafts and prolonged survival of animals with systemic tumor disease. Here we demonstrate that PPP also downregulates the IGF-1R, whereas the IR and several other receptors were not affected. PPP-induced IGF-1R downregulation required expression of the MDM2 E3 ligase, which recently was found to ubiquitinate and cause degradation of the IGF-1R. In addition knockdown of beta-arrestin1, the adaptor molecule known to bridges MDM2 and IGF-1R, prevented downregulation of the receptor and significantly decreased PPP-induced cell death. All together these data suggest that PPP downregulates IGF-1R by interfering with the action of beta-arrestin1/MDM2 as well as the achieved receptor downregulation contributes to the apoptotic effect of PPP.

Genetic polymorphisms involved in toxicant-metabolizing enzymes and the risk of chronic benzene poisoning in Chinese occupationally exposed populations

Benzene is a recognized haematotoxin and leukaemogen, but its mechanism of action and the role of genetic susceptibility are still unclear. Cytochrome P450 2E1 (CYP2E1) and myeloperoxidase (MPO) are involved in benzene activation; and NAD (P)H:quinine oxidoreductase 1 (NQO1), glutathione S-transferase theta 1 (GSTT1) and glutathione S-transferase mu 1 (GSTM1) participate in benzene detoxification. The common, well-studied single-nucleotide polymorphisms (SNPs) were analysed in these genes drawn from the toxicant-metabolizing pathways. A total of 100 workers with chronic benzene poisoning (CBP) and 90 controls were enrolled in China. There was a 2.82-fold (95% CI = 1.42-5.58) increased risk of CBP in the subjects with the NQO1 609C > T mutation genotype (T/T) compared with those carrying heterozygous (C/T) and wild-type (C/C). The subjects with the GSTT1 null genotype had a 1.91-fold (95% CI = 1.05-3.45) increased risk of CBP compared with those with GSTT1 non-null genotype. There was no association of CYP2E1 and MPO genotype with CBP. A three genes' interaction showed that there was a 20.41-fold (95% CI = 3.79-111.11) increased risk of CBP in subjects with the NQO1 609C > T T/T genotype and with the GSTT1 null genotype and the GSTM1 null genotype compared with those carrying the NQO1 609C > T C/T and C/C genotype, GSTT1 non-null genotype, and GSTM1 non-null genotype. The study provides evidence of an association of a gene-gene interaction with the risk of CBP.

Cyclobakuchiol C, a new bakuchiol derivative from Psoralea coryllfolia

A new compound, cyclobakuchiol C (1), together with four known bakuchiol derivatives, 2-5, was isolated from the non-polar fraction of the seeds of Psoralea corylifolia, and compounds 3-5 were identified from this plant for the first time. The structure of 1 was determined by spectroscopic methods, especially 2D NMR experiments.

Wurtzite-to-Rocksalt Structural Transformation in Nanocrystalline CoO

Hexagonal CoO nanocrystals are coarsened under hydrothermal conditions to investigate the effect of particle size on phase transformation and stability property. Structural stability and phase transformation of the hexagonal CoO phase have been investigated by X-ray powder diffraction with Rietveld refinement, transmission electron microscopy, X-ray absorption fine structure, and differential scanning calorimeter. It is found that the hexagonal CoO phase is a metastable phase, which increases its grain size from 50 to 250 nm for refluxing times from 1 to 6 h at 200 degrees C. After 12 h, cubic-structured CoO grains with an average grain size of 20 nm are observed, which spread around big hexagonal CoO grains. After about 24 h, only the cubic CoO phase with an average grain size of 25 nm is detected. The onset temperature of hexagonal-to-cubic phase transformation in CoO is estimated to be 378 degrees C by DSC, using a heating rate of 20 deg/min. The results obtained indicate that the hexagonal-to-cubic phase transformation in nanocrystalline CoO is by nucleation and growth mechanism, starting from the surface to the center of the hexagonal grains.

Wavelength division scanning for two-photon excitation fluorescence imaging

We investigate wavelength division scanning for two-photon excitation fluorescence imaging. Two-photon imaging using lateral wavelength division scanning is demonstrated. In addition, we theoretically analyse the spatial and temporal properties of a femtosecond laser beam focused by a Fresnel lens and investigate the feasibility of axial scanning using wavelength division.

Parthenogenetic Activation of Porcine Oocytes by Calcium Ionophore A23187

Abstract. This study was designated to clarify the influence of activation of porcine matured oocytes by calcium ionophore on in vitro development of the parthenotes. The follicular oocytes were matured, activated and cultured in North Carolina State University-23 (NCSU-23) medium supplemented with 10% porcine follicular fluid (pFF). The in vitro-matured oocytes were exposed to calcium ionophore at concentrations of 12.5, 25 or 50 μM for 3, 5, 7 or 9 min. The activation rate of the oocytes increased as concentration of ionophore decreased, being at 27–33 and 68–77 % for the oocytes treated with 50 and 12.5 μM ionophore, respectively. Almost all activated oocytes were haploid. The highest cleavage rate (76%) and developmental rate to morula (41%) were observed in the oocytes treated with 12.5 μM ionophore for 5 min. However, development to blastocyst was observed only in the oocytes treated with 25 μM ionophore for 3 and 5 min (3 and 4% of treated oocytes, respectively). We concluded that the activation treatment of the porcine oocytes with 12.5 μM ionophore for 5 min provided the highest develop-mental rate to morula, but this treatment is not sufficient to overcome a developmental block at the morula stage.

Human myometrial genes are differentially expressed in labor: a suppression subtractive hybridization study

Human parturition is effected by a cascade of factors, of which many are unknown. We aim to identify the genes that are changed by labor in the human myometrium by suppression subtractive hybridization. We also seek to ascertain whether these genes are differentially expressed in the myometrium at the upper or fundal and lower segments of the uterus. Term myometrial tissues were obtained from laboring and nonlaboring women undergoing cesarean section after obtaining informed consent. Total RNA was used in suppression subtractive hybridization (CLONTECH PCR Select) to produce two subtracted cDNA libraries enriched for genes expressed during or before labor, labor and not-in-labor libraries, respectively. Dot blot screening of 400 positive clones, constituting 20% of the two subtracted libraries, revealed 30 differentially expressed clones, 14 of which were up-regulated by labor. Among the 10 known genes that were up-regulated in labor, 6 had apparent immune regulatory and inflammatory roles. Three are well-known inflammatory mediators and modulators that were previously linked with parturition: IL-8, manganese superoxide dismutase (MnSOD), and metalloproteinase-9. Three others, interferon-inducible 1-8d gene, elongation factor 1alpha, and nucleophosmin, have not been previously linked with labor. Constitutively expressed genes, including cyclophilin and alpha-actin, were found to be altered by labor. Quantitative real-time RT-PCR using Taqman probes further confirmed the up-regulation of some of these genes. The amounts of the specific genes assayed were standardized to 18S ribosomal RNA and are expressed as mean +/- SEM. Quantitative real-time RT-PCR showed that IL-8 mRNA rose from 0.003 +/- 0.002 in nonlaboring samples (n = 38) to 0.24 +/- 0.11 (n = 20) in gestational-age-matched spontaneously laboring women (P = 0.035). Similarly, MnSOD rose from 0.11 +/- 0.02 (n = 24) to 1.23 +/- 0.56 (n = 24) in gestational-age-matched women (P = 0.047). Additionally, cyclophilin, often used as a constitutive or housekeeping gene marker, increased from 0.0008 +/- 0.0002 (n = 6) to 0.002 +/- 0.0004 (n = 6; P = 0.008) during labor. Notably, MnSOD mRNA was differentially distributed between the upper (0.63 +/- 0.18) and lower (0.15 +/- 0.05; n = 15; P = 0.022) segments of the uterus, but IL-8 was not (n = 17; P = 0.97). Induced labor further showed significantly higher levels of IL-8 (0.63 +/- 0.21; n = 14) than spontaneous labor (0.22 +/- 0.11; n = 20; P = 0.046), but not MnSOD (P = 0.1). This work identifies novel as well as known genes that were not previously associated with parturition. It extends previous data indicating that there is differential expression of some, but not all genes within the gravid human uterus. Inflammatory genes constitute a major proportion of the known genes found to be up-regulated in labor, lending support to the hypothesis of an inflammatory mechanism for human parturition. This work further indicates that many factors associated with human labor and their complex interactions remain to be elucidated.

IL-18-binding protein protects against lipopolysaccharide- induced lethality and prevents the development of Fas/Fas ligand-mediated models of liver disease in mice

IL-18-binding protein (IL-18BP) is a natural IL-18 inhibitor. Human IL-18BP isoform a was produced as fusion construct with human IgG1 Fc and assessed for binding and neutralizing IL-18. IL-18BP-Fc binds human, mouse, and rat IL-18 with high affinity (K(D) 0.3-5 nM) in a BIAcore-based assay. In vitro, IL-18BP-Fc blocks IL-18 (100 ng/ml)-induced IFN-gamma production by KG1 cells (EC(50) = 0.3 microg/ml). In mice challenged with an LD(90) of LPS (15 mg/kg), IL-18BP-Fc (5 mg/kg) administered 10 min before LPS blocks IFN-gamma production and protects against lethality. IL-18BP-Fc administered 10 min before LPS blocks IFN-gamma production induced by LPS (5 mg/kg) with ED(50) of 0.005 mg/kg. Furthermore, IL-18BP-Fc (5 mg/kg) abrogates LPS (5 mg/kg)-induced IFN-gamma production even when administered 6 days before LPS but shows no effect when administered 9 or 12 days before LPS. Given 10 min before LPS challenge to mice primed 12 days in advance with heat-killed Propionibacterium acnes, IL-18BP-Fc prevents LPS-induced liver damage and IFN-gamma and Fas ligand expression. Given at the moment of priming with P. acnes, IL-18BP-Fc decreases P. acnes-induced granuloma formation, macrophage-inflammatory protein-1alpha and macrophage-inflammatory protein-2 production and prevents sensitization to LPS. IL-18BP-Fc also prevents Con A-induced liver damage and IFN-gamma and Fas ligand expression as well as liver damage induced by Pseudomonas aeruginosa exotoxin A or by anti-Fas agonistic Ab. In conclusion, IL-18BP can be engineered and produced in recombinant form to generate an IL-18 inhibitor, IL-18BP-Fc, endowed with remarkable in vitro and in vivo properties of binding and neutralizing IL-18.

[Effects of supplementing calcium, iron and zinc on the fetus development and growth during pregnancy]

OBJECTIVES

The purpose of the present study is to determine the effects of supplementing the biscuits fortified with calcium (Ca), iron (Fe) and zinc (Zn) for pregnant women from the 5th month of gestation until delivery on the growth and development of fetus and to explore the best way to improve infant growth.

METHODS

A total of 313 healthy and primary pregnant women were enrolled and divided into five study groups based on their order visiting the hospitals for prenatal care. Each woman of the study groups was given three pieces of biscuit fortified with VD, Ca and VD, Ca, Zn and VD (Ca + Zn + VD), Ca, Fe, VC and VD (Ca + Fe + VD), Ca, Fe, VC, Zn and VD (Ca + Fe + Zn + VD), respectively, from the 5th month of gestation until delivery (24 weeks in total) daily. The fortified levels were 10 micrograms Ca from carbonate calcium, 10 mg Zn from lactate zinc, 10 mg Fe from ferrous lactate, and 50 mg VC, respectively. A parturient women was selected from the same hospital as control after one trial subject for each study groups selected. Placenta was weighed and umbilical cord venous blood and placenta tissue samples were collected after delivery for measuring Ca and other trace elements. Body weight and height of the new-born babies were measured.

RESULTS

The weight of placenta in control group (551.1 +/- 64.2) g was significantly (P < 0.05) heavier than other trial groups with Ca + Fe + Zn + VD (467.1 +/- 36.6) g, but contents of Ca and other trace elements in placenta of the control group were lower, which probably because of the lower nutrients intake of mothers in control group that would result in a compensation enlargement of placenta to get enough nutrients for fetus from mother. The Hb level in cord venous blood was significantly higher than that of maternal blood. There was no significant difference in activity of alkaline phosphatase between cord venous blood and material blood. The contents of Ca, Fe and Zn in cord venous plasma were all significantly higher than those in maternal plasma. Birth weight and height in Ca + Fe + Zn + VD group were the highest in all the groups, with birth weight of (3.53 +/- 0.33) kg, as compared with (3.28 +/- 0.54) kg in the control group. There was significant correlation between birth weight, weight for age and intake of Ca, Fe and Zn during pregnancy.

CONCLUSION

Supplementation of Ca + Fe + Zn + VitD during pregnancy is the best way to improve infant development and growth, based on the current Recommended Dietary Allowances (RDA) for pregnant women.

[Effects of supplementing of calcium, iron and zinc on women's health during pregnancy]

OBJECTIVES

To determine the effects of supplementing biscuits fortified with calcium (Ca) and vitamin D (VD), iron (Fe), vitamin C (VC) and zinc (Zn) to pregnant women from the 5th month of gestation until delivery on their health, and to explore a way to improve their Ca, Fe and Zn nutritional status during pregnancy.

METHODS

A total of 313 healthy and primary pregnant women were enrolled and divided into five study groups based on their order visiting the hospitals for prenatal care. Each woman of the study groups was given three pieces of biscuit fortified with VD, Ca and VD, Ca, Zn and VD (Ca + Zn + VD), Ca, Fe, VC and VD (Ca + Fe + VD), Ca, Fe, VC, Zn and VD (Ca + Fe + Zn + VD), respectively, from the 15th month of gestation until delivery (24 weeks in total) daily. The fortified levels were 10 micrograms VD, 400 mg Ca from carbonate calcium, 10 mg Zn from lactate zinc, 10 mg Fe from ferrous lactate, and 50 mg VC, respectively. A parturient women was selected from the same hospital as control after one trial subject for each study groups selected.

RESULTS

The daily dietary intakes of Ca, Zn and Fe in pregnant women were only 47.7%, 54.7% and 86.7% of the Recommended Dietary Allowances for Chinese. Incidence of anemia for mid-term pregnant women was 35.2%, and Fe-supplementation could significantly improved their hemoglobin level (P < 0.05). Prevalence of anemia in the groups of Ca + Fe + Zn + VD and Ca + Fe + VD was 35.3% and 40.7%, respectively, before Fe supplementation and reduced to zero and 4.0%, respectively, after Fe supplementation. Whereas, prevalence of anemia in the other groups without Fe supplementation still kept in a relatively high level. In the groups supplemented with Ca, their plasma Ca level increased, especially with the best results in Ca + VD group. Plasma level of Zn declined with length of gestation, which could be improved by Zn supplementation. Serum level of alkaline phosphatase activity increased a little bit with length of gestation. There was no significant difference in radial and ulnar bone mineral density (BMD) between trial groups and controls two months after delivery. Maternal radial and ulnar BMD correlated significantly with their dietary Ca intakes in Ca + VD group.

CONCLUSION

The best way to improve maternal nutritional status is supplementation of Ca + Fe + Zn + VitD, based on the Recommended Dietary Allowances for Chinese.

Technical note: reference values of haematocrit in young people and relationship with altitude

The purpose of this paper is to provide scientific basis for a unified standard reference value of haematocrit in young people in China. The reference values of haematocrit levels in healthy young people have been collected according to the Wintrobe methods; the relationship between the reference values of haematocrit in young people and altitude has been tested in this paper. It has been found that the reference value of haematocrit in young people increases when the altitude gradually increases, and such relationship is quite significant, The method of mathematical univariate regression analysis is used to deduce two regression equations: Y1 = 44.3 + 0.00357X +/- 3.7, and Y2 = 39.7+0.00318X +/- 2.6. If the altitude value of a s known, the particular area of China is known, the reference value of haematocrit in young people there can be calculated by means of the regression equations. Furhermore depending on the altitude, China can be divided into three districts: Qingzang District, Central District and Eastern District.

Elimination of latently HIV-1-infected cells by lymphoblasts armed with bifunctional antibody

The Fab' fragment of a monoclonal antibody (mAb) to CD3 and the F(ab')2 fragment of a mAb to human immunodeficiency virus 1 (HIV-1) gp41 were combined to generate a bifunctional antibody (BFA). The mAb to gp41 (IV1-4G6) has previously been shown to react with a number of HIV-1 strains and T-lymphoblastoid cells (TLBC) armed with the BFA (BFA-TLBC) effectively inhibited HIV-1 in primarily cultured lymphoblasts infected with the clinically isolated virus which was reactive to the mAb. Although BFA-TLBC could not cause cytolysis of 51Cr-labeled latently infected cells (OM-10.1) in 6 hr incubation, cocultivation of OM-10.1 cells with BFA-TLBC for 3 days or more eliminated the latently infected cells making the cells susceptible to BFA-TLBC. Therefore, BFA-TLBC may be beneficial for HIV-infected patients in eradicating latently infected cells which can not be eliminated even with highly active antiretroviral therapy (HAART).

Changes in serum leptin levels in chronic renal failure patients with metabolic acidosis

OBJECTIVE

To examine the relationship between serum leptin levels (SLL) and metabolic acidosis in patients with chronic renal failure (CRF).

DESIGN

SLL in control patients and in predialysis patients with CRF were measured and compared. SLL before and after correction of acidosis in patients with CRF were also compared.

PATIENTS AND CONTROLS

Twenty-five patients with CRF (10 men and 15 women) aged 51.2 +/- 10.4 years and control patients (healthy subjects, 23 men and 25 women) aged 42.1 +/- 12.6 years were studied.

INTERVENTION

Five percent sodium bicarbonate (NaHCO(3), 2 to 3 mL/kg) was intravenously infused on the morning of the first day of treatment. NaHCO(3) was taken orally at a dosage of 50 to 200 mg/kg/d for 3 to 5 days thereafter.

MAIN OUTCOME MEASURE

SLL before and after NaHCO(3) treatment was measured by radioimmunoassay, and blood gas was measured before and after correction of metabolic acidosis in patients with CRF.

RESULTS

SLL in the normal control group (n = 48) was 10.04 +/- 7.0 ng/mL and was realated to body mass index (BMI) (P =.0331). SLL in men (n = 23) was lower than that in female controls (n = 25, P <.01). SLL in patients with CRF (n = 25) before (plasma HCO(3)(-), 13.03 +/- 3.05 mmol/L) and immediately after improvement of metabolic acidosis (plasma HCO(3)(-), 18.35 +/- 4.21 mmol/L) was 14.52 +/- 9.27 ng/mL and 15.34 +/- 11.89 ng/mL (P >.05), respectively. SLL measured 3 to 5 days after treatment for metabolic acidosis (plasma HCO(3)(-), 20.46 +/- 4.03 mmol/L) was 19.33 +/- 14.58 ng/mL, which was significantly higher than that in the normal control group and that in acidotic patients before NaHCO(3) treatment (P <.01).

CONCLUSIONS

SLL in acidotic patients with CRF were comparable to that in control subjects, and SLL was significantly increased after correction of metabolic acidosis in patients with CRF. The preliminary results suggest that hyperleptinemia in patients with CRF may be masked by metabolic acidosis and that metabolic acidosis may inhibit leptin synthesis or secretion. Further studies are needed to clarify the mechanisms.

Over-expression of beta-1,4-galactosyltransferase I, II, and V in human astrocytoma

PURPOSE

beta-1,4-Galactosyltransferase (beta-1,4-GalT) I, II, and V are the enzymes responsible for the biosynthesis of N-acetyllactosamine on N-glycans by transferring UDP-galactose to the terminal N-acetylglucosamine (N-GlcNAc) residues with the formation of a beta-1,4-linkage. Neoplasms undergo various changes in the carbohydrate of their glycoconjugates, indicating the possible changes in glycosyltransferases themselves.

METHOD

Therefore, we compared the expression of beta-1,4-GalTs between astrocytoma and normal brain tissues.

RESULTS

Our reverse-transcription polymerase chain reaction (RT-PCR) results showed that beta-1,4-GalT I transcript was absent in normal adult brain but detectable in grade II, III, and IV astrocytomas; the level of beta-1,4-GalT II transcript was increased in grade II, III, and IV astrocytomas while only a trace amount was found in normal brain; beta-1,4-GalT V transcript existed in normal brain and increased in the process of astrocytoma progress, with the highest level in grade IV astrocytoma. By Ricinus communis agglutinin-1 (RCA-1) lectin blot assay, we also found the more extensive galactosylated bands in astrocytomas compared with normal brain. A major 61kD protein was galactosylated in astrocytoma but not in normal brain tissues.

CONCLUSION

These results indicate that the increase of galactosylation in astrocytomas may be caused by the alterations of gene expression of beta-1,4-GalT I, II, and V and that the malignant degree of astrocytoma is correlated with the expression of beta-1,4-GalT V.

Protein adducts of 1,4-benzoquinone and benzene oxide among smokers and nonsmokers exposed to benzene in China

Hemoglobin (Hb) and albumin (Alb) adducts of the benzene metabolites benzene oxide (BO) and 1,4-benzoquinone (1,4-BQ) were analyzed by gas chromatography-mass spectrometry in 43 exposed workers and 44 unexposed controls from Shanghai, China, as part of a larger cross-sectional study of benzene biomarkers. When subjects were divided into controls (n = 44) and workers exposed to </=31 ppm (n = 21) and >31 ppm (n = 22) of benzene, median 1,4-BQ-Alb adducts were 2110, 5850, and 13,800 pmol/g Alb, respectively (correlation with exposure: Spearman r = 0.762; P < 0.0001); median BO-Alb adducts were 106, 417, and 2400 pmol/g Alb, respectively (Spearman r = 0.877; P < 0.0001); and median BO-Hb adducts were 37.1, 50.5, and 136 pmol/g Hb, respectively (Spearman r = 0.757; P < 0.0001). To our knowledge, this is the first observation that adducts of 1,4-BQ are significantly correlated with benzene exposure. When compared on an individual basis, Alb adducts of 1,4-BQ and BO and Hb adducts of BO were highly correlated with each other and with urinary phenol and hydroquinone (P < 0.0001 for all of the comparisons). Although detectable in the assays, Hb adducts of 1,4-BQ and both Hb and Alb adducts of 1,2-BQ produced erratic results and are not reported. Interestingly, cigarette smoking increased Alb adducts of 1,4-BQ but not of BO, suggesting that benzene from cigarette smoke was not the primary contributor to the 1,4-BQ adducts.

[Clinical efficacy of lamivudine in the treatment of chronic hepatitis B]

OBJECTIVE

To study the clinical efficacy and safety of lamivudine in the treatment of chronic hepatitis B.

METHODS

72 patients with hepatitis B were randomly assigned into lamivudine (n = 54) and placebo groups (n = 18) for 12 weeks. Then, all the patients received lamivudine 100 mg daily until week 104. Clinical symptoms, liver function tests, serum HBV DNA and YMDD mutation were evaluated.

RESULTS

HBV DNA response rate of lamivudine group was higher than that of placebo group after 12 weeks treatment (61% vs 6%, P < 0.01). ALT sustained normalization rate of lamivudine group was higher than that of placebo group (65% vs 11%, P < 0.05). At week 52 and week 104, HBV DNA response rate was 78% and 36% respectively, whereas the normalization rate of ALT was 39% and 33% respectively. Proportion of HBeAg/anti-HBe seroconversion was both 6.1% at week 52 and 104. Overall YMDD mutation rate was 13.7% at week 52 and 39.7% at week 104. The incidence of adverse effects was similar for lamivudine and placebo group at week 12. There was no severe drug-related adverse events during 104 weeks treatment.

CONCLUSION

Lamivudine 100 mg daily could suppress HBV replication rapidly and be well tolerated. However, in some cases, YMDD mutation may lead to HBV DNA breakthrough.

Stimulatory effects of B7-related protein-1 on cellular and humoral immune responses in mice

Inducible costimulator (ICOS) and B7-related protein-1 (B7RP-1) constitute a receptor-ligand pair involved in T cell costimulation. In this study, the stimulatory effects of B7RP-1 on cellular and humoral immune responses were investigated giving mice a construct with the extracellular domain of murine B7RP-1 fused with human IgG1 Fc (B7RP-1-Fc). B7RP-1-Fc stimulated contact hypersensitivity (CH) given near either the time of sensitization or challenge with oxazolone. When given near challenge time, B7RP-1-Fc stimulated CH more than a construct containing the extracellular domain of murine B7.2 and Fc (B7.2-Fc). B7RP-1-Fc increased the number of cells in lymph nodes draining the skin sensitized with oxazolone, especially activated T cells. B7RP-1-Fc also increased the ability of the cells in these lymph nodes to induce CH when transfused into naive mice. B7RP-1-Fc stimulated the production of anti-keyhole limpet hemocyanin (KLH) Ab, increasing anti-KLH IgG, IgG2a, and IgE, whereas B7.2-Fc did not affect this production. B7RP-1-Fc also increased the number of cells in lymph nodes draining the skin immunized with KLH and their production of IFN-gamma, IL-4, and IL-10 in response to KLH. Finally, B7RP-1-Fc increased the presence of eosinophils in the bronchoalveolar lavage and lungs of mice sensitized and challenged with OVA so to mount an asthmatic reaction. B7RP-1-Fc stimulates both cellular and humoral immune responses in vivo by increasing number and function of T and B cells reacting to Ag exposure.

Biomarker risk assessment and bladder cancer detection in a cohort exposed to benzidine

BACKGROUND

Cancer screening with highly sensitive, specific biomarkers that reflect molecular phenotypic alterations is an attractive strategy for cancer control. We examined whether biomarker profiles could be used for risk assessment and cancer detection in a cohort of Chinese workers occupationally exposed to benzidine and at risk for bladder cancer.

METHODS

The cohort consisted of 1788 exposed and 373 nonexposed workers, followed from 1991 through 1997. We assayed urothelial cells from voided urine samples for DNA ploidy (expressed as the 5C-exceeding rate [DNA 5CER]), the bladder tumor-associated antigen p300, and a cytoskeletal protein (G-actin). Workers were stratified into different risk groups (high, moderate, and low risk) at each examination based on a predefined biomarker profile. For workers who developed bladder cancer, tumor risk assessment was analyzed from samples collected 6-12 months before the cancer diagnosis. The associations between risk group and subsequent development of bladder cancer were analyzed by Cox proportional hazards regression analysis and logistic analysis, after adjustment. All statistical tests were two-sided.

RESULTS

Twenty-eight bladder cancers were diagnosed in exposed workers and two in nonexposed workers. For risk assessment, DNA 5CER had 87.5% sensitivity, 86.5% specificity, an odds ratio (OR) of 46.2 (95% confidence interval [CI] = 8.1 to 867.0), and a risk ratio (RR) of 16.2 (95% CI = 7.1 to 37.0); p300 had 50.0% sensitivity, 97.9% specificity, an OR of 40.0 (95% CI = 9.0 to 177.8), and an RR of 37.9 (95% CI = 16.8 to 85.3). The risk of developing bladder cancer was 19.6 (95% CI = 8.0 to 47.9) times higher in workers positive for either the DNA 5CER or p300 biomarkers than in workers negative for both biomarkers and 81.4 (95% CI = 33.3 to 199.3) times higher in workers positive for both biomarkers. G-actin was a poor marker of individual risk.

CONCLUSIONS

Occupationally exposed workers at risk for bladder cancer can be individually stratified, screened, monitored, and diagnosed based on predefined molecular biomarker profiles.

Novel structures and properties of gold nanowires

The structures of free-standing gold nanowires are studied by using molecular-dynamics-based genetic algorithm simulations. Helical and multiwalled cylindrical structures are found for the thinner nanowires, while bulk-like fcc structures eventually form in the thicker nanowires up to 3 nm in diameter. This noncrystalline-crystalline transition starts from the core region of nanowires. The vibrational, electronic, and transport properties of nanowires are investigated based on the optimal structures. Bulklike behaviors are found for the vibrational and electronic properties of the nanowires with fcc crystalline structure. The conductance of nanowires generally increases with wire diameter and depends on the wire structure.