Polymorphisms of PXK are associated with autoantibody production, but not disease risk, of systemic lupus erythematosus in Chinese mainland population

Systemic lupus erythematosus (SLE) is a complex immune disease. The genetic variation in the PXK gene was found to associate with SLE in Caucasian populations. However, the association of rs6445975 with SLE has not been extensively studied in a Chinese mainland population. A total of 288 SLE patients and 357 controls were recruited. Unlabeled probe-based high-resolution melting analysis (HRMA) was used in genotyping. HRMA with unlabeled probe successfully distinguished all genotypes. Neither genotype nor allele frequencies of SNP rs6445975 showed statistically significant differences between SLE patients and controls. The association of SNP rs6445975 with the diagnostic criteria of SLE was also examined. No obvious association was observed between rs6445975 and the incidence of clinical symptoms. However, the minor allele (G) of rs6445975 was found to significantly associate with increased abnormalities of anti-Smith (p = 0.004, odds ratio (OR) = 1.95, 95% confidence interval (CI) = 1.22-3.09), anti-Ro (p = 0.015, OR = 1.69, 95% CI = 1.10-2.58), anti-La (p = 0.008, OR = 1.86, 95% CI = 1.17-2.93) and C3C4 (p = 0.007, OR = 1.79, 95% CI = 1.17-2.74). Polymorphisms of rs6445975 in the PXK gene were associated with autoantibody production, but not disease risk, of systemic lupus erythematosus in a Chinese population.

High-resolution melting analysis of PCDH10 methylation levels in gastric, colorectal and pancreatic cancers

Protocadherins are celladhesion molecules with 6 or 7 cadherin motifs in their extracellular domain and various cyotoplasmic domains. PCDH10 was characterized a novel tumor suppressive gene in and was epigenetically silenced in multiple haematologic malignancies as well as some solid tumors such as gastric cancer, nasopharyngeal carcinoma and esophageal carcinoma. High-resolution melting (HRM) analysis has been used as a novel tool for analysis of promoter methylation. In our study, we used HRM analysis to detect the methylation levels of PCDH10 gene in 100 gastric cancers, 100 colorectal cancers, 70 pancreatic cancers and equal number of adjacent normal tissues. The frequency of PCDH10 methylation in all three types of cancers was significantly higher than that in normal tissues. Consistent with previous reports, expression levels of PCDH10 were inversely correlated with methylation levels. But we didn't find significant association between PCDH10 methylation status and TNM staging in all three types of cancers. In summary, application of HRM analysis to large amount of clinical samples proves to be a fast and high-throughput way to investigate the epigenetic status of PCDH10. And this is the first study to evaluate the prevalence of PCDH10 methylation based on large amount of tumor samples, showing that epigenetic regulation of PCDH10 was associated with carcinogenesis.

All-electric quantum point contact spin-polarizer

The controlled creation, manipulation and detection of spin-polarized currents by purely electrical means remains a central challenge of spintronics. Efforts to meet this challenge by exploiting the coupling of the electron orbital motion to its spin, in particular Rashba spin-orbit coupling, have so far been unsuccessful. Recently, it has been shown theoretically that the confining potential of a small current-carrying wire with high intrinsic spin-orbit coupling leads to the accumulation of opposite spins at opposite edges of the wire, though not to a spin-polarized current. Here, we present experimental evidence that a quantum point contact -- a short wire -- made from a semiconductor with high intrinsic spin-orbit coupling can generate a completely spin-polarized current when its lateral confinement is made highly asymmetric. By avoiding the use of ferromagnetic contacts or external magnetic fields, such quantum point contacts may make feasible the development of a variety of semiconductor spintronic devices.

Transformation of nitrogen and distribution of nitrogen-related bacteria in a polluted urban stream

Most researchers focused on either nitrogen species or microbial community for polluted urban stream while ignoring the interaction between them and its effect on nitrogen transformation, which restricted the rational selection of an effective and feasible remediation technology. Taking Buji stream in Shenzhen (China) as target stream, the distribution of nitrogen-related bacteria was investigated by most probable number (MPN) besides analysis of nitrogen species etc. The nitrogen-related bacteria in sediment were 10(2) times richer than those in water. Owing to their faster growth, the MPN of ammonifying bacteria and denitrifying bacteria were 10(5) and 10(2) times higher than those of nitrifying bacteria, respectively. The ammonifying bacteria numbers were significantly related to BOD5 in water, while nitrifying bacteria in sediment correlated well with nitrate in water. Thus, nitrification occurred mainly in sediment surface and was limited by low proportion of nitrifying bacteria. The denitrifying bacteria in sediment had good relationship with BOD5 and nitrite and nitrate in water. Low DO and rich organic compounds were beneficial to denitrification but unfavourable to nitrification. Denitrification was restricted by low nitrite and nitrate concentration. These results could be served as a reference for implementing the remediation scheme of nitrogen polluted urban stream.

BML-111, a lipoxin receptor agonist, modulates the immune response and reduces the severity of collagen-induced arthritis

OBJECTIVE

Lipoxins (LXs) are endogenous antiinflammatory and pro-resolving eicosanoids generated during various inflammatory conditions. Recent research has revealed the novel immunomodulatory function of LXs. The aim of this study is to investigate whether LXs modulate the pathogenesis of collagen-induced arthritis (CIA), a typical chronic immune-mediated inflammatory disease.

METHODS AND RESULTS

CIA was induced in DBA/1 mice and BML-111, a lipoxin A4 receptor agonist, was administrated. Results indicated that compared with untreated CIA mice, both clinical disease activity scores and histological destruction of joint were significantly reduced in BML-111-treated CIA mice. The dampened joint injury was accompanied by decreased concentrations of serum pro-inflammatory cytokines tumor necrosis factor alpha and interleukin-6 in BML-111-treated CIA mice. In addition, proliferation of isolated spleen cells, as well as circulating levels of antibody to type II collagen, were reduced significantly in BML-111-treated CIA mice.

CONCLUSION

BML-111 attenuated CIA in part by negatively regulating the immune response, which implicates the potential pharmacological value of LXs in the treatment of chronic immune-mediated inflammatory diseases such as RA.

The new water-soluble artemisinin derivative SM905 ameliorates collagen-induced arthritis by suppression of inflammatory and Th17 responses

BACKGROUND AND PURPOSE

Our previous study showed that SM905, a novel artemisinin derivative, exhibited potent immunosuppressive activity. In this study, we evaluate preventive and therapeutic effect of SM905 on collagen-induced arthritis (CIA) in DBA/1 mice, and investigate its mechanisms both in inflammatory and autoimmune aspects of the disease.

EXPERIMENTAL APPROACH

CIA was induced by type II bovine collagen (CII) in DBA/1 mice. SM905 was given orally either before (continuously 1 day before booster immunization) or after disease onset (continuously 14 days after booster immunization). Disease incidence and severity were monitored, mRNA expression of proinflammatory mediators was determined by real-time PCR, purified T cell proliferation was assessed using [(3)H]-thymidine incorporated assay, and T helper (Th) 17/Th1/Th2 type cytokine production was examined by ELISA.

KEY RESULTS

Oral treatment with SM905 delayed disease onset, reduced arthritis incidence and severity, and suppressed the enhanced expression of pro-inflammatory cytokines, chemokines and chemokine receptors in draining lymph nodes. The CII-induced T cell proliferation and production of interleukin (IL)-17A by T cells were strikingly inhibited. Correspondingly, the mRNA expression of IL-17A and RORgamma t (a specific transcription factor for Th17) was also reduced. This effect was coupled with a striking reduction of IL-6 production, which has a critical role in Th17 development. In established arthritis, SM905 profoundly inhibited disease progression, reduced IL-17A and RORgamma t mRNA expression, and suppressed pro-inflammatory mediator expression in arthritic joints.

CONCLUSIONS AND IMPLICATIONS

SM905 had beneficial effects on CIA by suppressing inflammatory and pathogenic Th17 responses.

Influence of substrate conductivity on circulation reversal in evaporating drops

Nonuniform evaporation from sessile droplets induces radial convection within the drop, which produces the well-known "coffee-ring" effect. The evaporation also induces a gradient in temperature and consequently a gradient in surface tension, generating a Marangoni flow. Here we investigate theoretically and experimentally the thermal Marangoni flow and establish criteria to gauge its influence. An asymptotic analysis indicates that the direction of the flow depends on the relative thermal conductivities of the substrate and liquid, k_{R} identical withk_{S}/k_{L}, reversing direction at a critical contact angle over the range 1.45<k_{R}<2. We corroborate the theory experimentally and demonstrate that the Marangoni flow can significantly influence the resulting patterns of particle deposition.

The association of epidermal growth factor receptor (EGFR) polymorphisms and clinicopathological factors with skin rash on gefitinib use

18118

Background: Skin rash is the most common toxicity of EGFR-targeted therapy. Skin rash of EGFR inhibitor is associated with longer survival or tumor response. However, the clinical and genetic factors associated with this skin rash are not well understood. Methods: Fifty-two non-small-cell lung cancer patients enrolled in a prospective clinical trial of first-line gefitinib treatment were genotyped for EGFR intron 1 CA repeat polymorphism (CAn) and single nucleotide polymorphisms at promoters G-216T, C-191A, and R521K. Grade 2 to 3 skin rash within 4 weeks of treatment (early G2/3 rash) was correlated with the genotype and clinicopathological features of the patients by multivariate logistic regression. Results: Seventeen patients (32.7%) developed early G2/3 rash. In multivariate logistic regression analysis, only the CAn genotype was associated with early G2/3 rash and the effect was modified by patient age. Early G2/3 rash developed in 21% of patients with homozygous long allele (19 to 22 repeats, L) genotype (4/19), 31% of heterozygous short allele (15 to 18 repeats, S) / L genotype (8/26), and 71% of S/S genotype (5/7), respectively. The median ages of patients with early G2/3 rash and patients without early G2/3 rash were 57 years (range: 39–77) and 69 years (range: 43–86), respectively. The estimated logarithm of odds ratio (ln OR) for early G2/3 rash, as compared to S/S genotype, for S/L genotype was -0.038 multiplied by patient age (P = 0.011); and the ln OR for L/L genotype was -0.050 multiplied by patient age (P = 0.004). Fifty patients were evaluable for response. In logistic regression analysis, early G2/3 rash correlated with tumor response (P = 0.027). However, the CAn genotype was not significantly correlated with tumor response (P = 0.43). Conclusions: Homozygous short allele of EGFR CAn is more likely to develop skin rashes on gefitinib treatment. Genotyping of EGFR CAn appears to be a useful predictive marker for development of skin rashes on gefitinib use.

[Table: see text]

Comparison of the effects of acylation and amidation on the antimicrobial and antiviral properties of lactoferrin

AIMS

To compare amidation and acylation of lactoferrin (LF) from bovine milk, as a means of enhancing its antimicrobial and antiviral properties.

METHODS AND RESULTS

LF was chemically modified by amidation with a 1-ethyl-3-[3-(dimethylamino) propyl] carbodiimide (EDC) in the presence of ammonium ions or by acylation with either succinic or acetic anhydride. In the test systems used, amidation substantially enhanced the activity of LF against Pseudomonas fluorescens in comparison with native LF. However, increasing the net negative charge of LF by acylation had no effect on the activity of LF against P. fluorescens, and abrogated the antimicrobial activity of LF against Bacillus subtilis and Saccharomyces cerevisiae. Increasing the net negative charges of LF by acylation eliminated its antimicrobial and antiviral effects against poliovirus and feline calicivirus (nonenveloped viruses).

CONCLUSIONS

The addition of positive charges to LF via amidation enhanced antimicrobial properties in contrast to increasing the negative charges by acylation, which abolished both the antimicrobial and antiviral properties of LF.

SIGNIFICANCE AND IMPACT OF THE STUDY

The effects of charge alteration of LF determined in this study provides a basis for further development of LF formulations with enhanced antimicrobial effectiveness for use in food process hygiene, veterinary and health-care applications.

Investigation of the immunosuppressive activity of artemether on T-cell activation and proliferation

BACKGROUND AND PURPOSE

Artemisinin and its derivatives exhibit potent immunosuppressive activity. The purpose of the current study was to examine the immunosuppressive activity of artemether directly on T lymphocytes and to explore its potential mode of action.

EXPERIMENTAL APPROACH

In vitro, T-cell proliferation was measured using [(3)H]-thymidine incorporation assay in cells stimulated with ConA, alloantigen and anti-CD3 antibody. CFSE-labeled cell division and cell cycle distribution were monitored by flow cytometry. In vivo, the effects of artemether were evaluated in delayed-type hypersensitivity (DTH) and purified T-cell responses to ovalbumin in ovalbumin-immunized mice. The activation of extracellular signal-regulated kinase1/2 (ERK1/2) and Raf1 were assessed by Western blot analysis and the activation of Ras was tested in pull-down assays.

KEY RESULTS

We show that, in vitro, artemether suppressed ConA- or alloantigen-induced splenocyte proliferation, influenced production of the cytokines IL-2 and IFN-gamma and inhibited cell cycle progression through the G0/G1 transition. In vivo, administration of artemether attenuated CD4 T-cell-mediated DTH reaction, and suppressed antigen-specific T-cell response in immunized mice. Further experiments showed that, treatment with artemether impaired both antigen- and anti-CD3-induced phosphorylation of ERK. In primary T cells, artemether profoundly inhibited anti-CD3-induced phosphorylation of Raf1 and activation of Ras.

CONCLUSIONS AND IMPLICATIONS

This study provided experimental evidence of the immunosuppressive effects of artemether directly on T cells both in vitro and in vivo. Its immunosuppressive mechanism involved inhibition of the activation of the Ras-Raf1-ERK1/2 protein kinase cascade in T cells.

Investigation of peptomimetics of GD2 antibodies as targeted therapy against human small cell lung cancer in-vitro

13128

Background: GD2 is a well-established target that has been validated for neuroblastoma and small cell lung cancer. The therapeutic and diagnostic use of monoclonal antibodies directed to GD2 in small cell lung cancer is well documented. It has been shown that the binding of GD2 monoclonal antibodies alone can induce growth suppression and cell death of small cell lung cancer cells in-vitro. Our laboratory has developed synthetic small molecule peptomimetics as ligands of GD2. Peptomimetics have favorable in-vivo pharmacological properties compared to antibodies with no immunogenicity, longer half-lives, low toxicity, good tissue penetration, biodistribution and high target selectivity. This study proposed to determine the efficacy of peptomimetics of GD2 antibodies against small cell lung cancer cells in-vitro. Methods: 2 human cell lines were studied. H69 is a classic small cell lung cancer and H82 is a morphological variant small cell lung cancer both of which have been reported in the literature to express GD2. Cell surface expression of ganglioside GD2 was analyzed by flow cytometry (FACScan, BD Biosciences) using GD2 mAB 3F8 and GD2 mAB ME361. Cell proliferation was assessed using standard MTT assays with serum containing medium and cultured for approximately 3 doubling times for each cell line. The cell lines were exposed to increasing doses of GD2 specific peptomimetic to a maximum of 25 uM with controls including serum containing media with and without a GD2 negative peptomimetic and assessed for cell proliferation. Results: GD2 expression was confirmed for both cell lines- H69 and H82 using FACs. Exposure of the GD2 specific peptomimetic clearly caused growth suppression on the range of 35–40% when compared to controls. A dose response relationship was demonstrated with a plateau beyond 10 uM concentrations. Each experiment repeated ≥ 3 occasions. Conclusions: We have shown that attachment of GD2 specific peptomimetics can cause decreased cell proliferation in 2 small cell lung cancer cell lines H69 and H82. We have shown that there is a dose response relationship by which these compounds reduce cell viability. Peptomimetics of GD2 antibodies show promise as a targeted therapy for small cell lung cancer in-vitro and warrant further study.

[Table: see text]

Estrogen receptor β represses breast tumor growth and angiogenesis in vivo

10101

Background: Estrogens are well known stimulators of breast cancer cell growth in vitro as well as in vivo. Two different estrogen receptors exist, namely estrogen receptor (ER) α and β. ERα mediates the proliferative effect of estrogen in breast cancer cells and we have earlier shown that ERβ inhibits cell-cycle progression in vitro. Estrogens are well known stimulators of in vivo breast cancer cell growth as well as angiogenesis, and the effect is mediated through ERα. The function of ERβ in this context is not well understood. Methods: We have used ERα-positive T47D breast cancer cells stably transfected with a Tet/Off regulated ERβ expression vector system. The ERβ-inducible tumor cells are studied in vitro as well as in vivo. Results: By transplanting ERβ-inducible breast cancer cells into SCID-mice, we show that ERβ inhibits tumor growth and reduces the volume of established tumors. Furthermore, we show by immunohistochemistry, that the number of blood microvessels in the tumor periphery is decreased by ERβ expression, counteracting the well-known pro-angiogenic effect of ERα. By Western blot analysis on tumor extracts, we show that the concentration of the important pro-angiogenic growth factors VEGF and bFGF, normally expressed by breast tumor cells, is decreased in the ERβ-expressing tumors compared to the normal tumors. To exclude that the observed anti-angiogenic effect is just a result of reduced tumor growth, we incubated Tet/Off regulated ERβ expressing cells in vitro, during non-hypoxic conditions. We found that the expression of ERβ leads to decreased expression of VEGF and PDGFβ at the mRNA and protein-levels. In transient transfection assays, we found estrogen-ERα mediated up regulation of VEGF, PDGFβ and bFGF-promoter activities in T47D cells, and these activities were all suppressed following co-transfection with an ERβ-expression vector. Conclusions: We conclude that ERβ inhibits growth factor expression at transcriptional level in breast cancer cells; taken together, our data indicates that ERβ inhibits growth and angiogenesis of tumors formed by T47D breast cancer cells. This makes ERβ an interesting therapeutic target in breast cancer and perhaps treatment with the newly designed ERβ-selective ligands might work as a new anti-proliferative and anti-angiogenic therapy.

No significant financial relationships to disclose.

The GATA site-dependent hemogen promoter is transcriptionally regulated by GATA1 in hematopoietic and leukemia cells

Hemgn (a gene symbol for hemogen in mouse, EDAG in human and RP59 in rat) encodes a nuclear protein that is highly expressed in hematopoietic tissues and acute leukemia. To characterize its regulatory mechanisms, we examined the activities of a Hemgn promoter containing 2975 bp of 5' flanking sequence and 196 bp of 5' untranslated region (5' UTR) sequence both in vitro and in vivo: this promoter is preferentially activated in a hematopoietic cell line, not in nonhematopoietic cell lines, and is sufficient to drive the transcription of a lacZ transgene in hematopoietic tissues in transgenic mice. Mutagenesis analyses showed that the 5' UTR including two highly conserved GATA boxes is critical for the promoter activity. GATA1, not GATA2, binds to the GATA binding sites and transactivates the Hemgn promoter in a dose-dependent manner. Furthermore, the expression of human hemogen (EDAG) transcripts were closely correlated with levels of GATA1 transcripts in primary acute myeloid leukemia specimens. This study suggests that the Hemgn promoter contains critical regulatory elements for its transcription in hematopoietic tissues and Hemgn is a direct target of GATA1 in leukemia cells.

CACNA1A mutations causing episodic and progressive ataxia alter channel trafficking and kinetics

BACKGROUND

CACNA1A encodes CaV2.1, the pore-forming subunit of P/Q-type voltage-gated calcium channel complexes. Mutations in CACNA1A cause a wide range of neurologic disturbances variably associated with cerebellar degeneration. Functional studies to date focus on electrophysiologic defects that do not adequately explain the phenotypic findings.

OBJECTIVE

To investigate whether some missense mutations might interfere with protein folding and trafficking, eventually leading to protein aggregation and neuronal injury.

METHODS

The authors studied the functional consequences of two pore missense mutations, C287Y and G293R, in two families with EA2, one newly discovered and the other previously reported. Both mutations caused episodic and interictal ataxia. The biophysical properties of mutant and wild type calcium channels were examined by whole-cell patch-clamp recordings in transfected COS-7 cells. The plasma membrane targeting was visualized by confocal fluorescence imaging on CaV2.1 tagged with green fluorescent protein.

RESULTS

The mutant channels exhibited a marked reduction in current expression and deficiencies in plasma membrane targeting.

CONCLUSIONS

In addition to altered channel function, the deficiency in protein misfolding and trafficking associated with the C287Y and G293R mutants may contribute to the slowly progressive cerebellar ataxia.

Mutation in the glutamate transporter EAAT1 causes episodic ataxia, hemiplegia, and seizures

BACKGROUND

Transporters, ion pumps, and ion channels are membrane proteins that regulate selective permeability and maintain ionic gradients across cell membranes. Mutations in CACNA1A encoding a neuronal calcium channel and ATP1A2 encoding an ion pump cause episodic ataxia, hemiplegic migraine, and seizures. Mutant gene products of both CACNA1A and ATP1A2 may affect neurotransmission of glutamate, the most abundant excitatory amino acid neurotransmitter.

METHODS

We examined our patient population with episodic ataxia and hemiplegic migraine but with no mutation in either CACNA1A or ATP1A2. We looked for mutations in SLC1A3, which encodes the glutamate transporter excitatory amino acid transporter (EAAT) 1 that is important in removing glutamate from the synaptic cleft.

RESULTS

A patient with episodic ataxia, seizures, migraine, and alternating hemiplegia has a heterozygous mutation in SLC1A3 that is not present in his asymptomatic parents and controls. Expression studies of the mutant EAAT1 showed decreased expression of the protein with a markedly reduced capacity for glutamate uptake. When coexpressed, the mutant EAAT1 decreased the activity of wild-type EAAT1 but not of two other transporters EAAT2 or EAAT3, suggesting that mutant EAAT1 specifically multimerizes with wild-type EAAT1 to exert its dominant negative effect.

CONCLUSION

Our data show that a heterozygous mutation in EAAT1 can lead to decreased glutamate uptake, which can contribute to neuronal hyperexcitability to cause seizures, hemiplegia, and episodic ataxia.

The risk of venous thromboembolic disease in patients with monoclonal gammopathy of undetermined significance

BACKGROUND

Recent evidence indicates that patients with multiple myeloma receiving combination chemotherapy containing thalidomide are at a significantly high risk for venous thromboembolic disease (VTD). However, information on the occurrence of VTD in a related disorder, benign monoclonal gammopathy of undetermined significance (MGUS), is limited.

PATIENTS AND METHODS

We prospectively investigated patients with MGUS for the occurrence of VTD. The diagnosis of MGUS was based on well known criteria for the disorder. The variables examined were sex, age, race, presence of underlying conditions, level and type of immunoglobulin [serum monoclonal (M)-protein] platelet counts and level of fibrinogen.

RESULTS

Of a total of 310 patients with MGUS, 19 (6.1%) developed VTD after a median follow-up of 44 months (range 12-67 months). In a univariate analysis, age >/=65 years (P=0.01), M-protein >/=16 g/l (P=0.001) and progression to plasma cell or lymphoproliferative disorders (28 of 310 patients; P=0.001) were significant risk factors for VTD. In multivariate analysis, M-spike >/=16 g/l [risk ratio (RR)=6.3; 95% confidence interval (CI) 2.25-17.6; P=0.001] and future development of plasma cell or lymphoproliferative disorder (RR = 4.2; 95% CI 1.64-10.7; P=0.003) were variables strongly associated with the occurrence of VTD. A total of 46 patients (14.8%) died during the follow-up period of the study.

CONCLUSION

This study demonstrates that patients with MGUS are at increased risk for VTD. Although a clear reason for the pre-thrombotic state in these patients is not currently evident, few risk factors were identified in the group of patients examined.

The effect of bovine lactoferrin and lactoferricin B on the ability of feline calicivirus (a norovirus surrogate) and poliovirus to infect cell cultures

AIMS

To characterize the effect of bovine lactoferrin and lactoferricin B against feline calicivirus (FCV), a norovirus surrogate and poliovirus (PV), as models for enteric viruses.

METHODS AND RESULTS

Crandell-Reese feline kidney (CRFK) cells were used for the propagation of FCV and monkey embryo kidney (MEK) cells for PV. The assays included visual assessment of cell lines for cytopathic effects and determination of the percentage cell death using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium] dye reduction assay. Incubation of bovine lactoferrin with CRFK cells either prior to or together with FCV inoculation substantially reduced FCV infection. In contrast, the interference of lactoferrin with the infection of cells with PV was demonstrated only when lactoferrin was present with cell lines and virus for the entire assay period. Using indirect immunofluorescence, lactoferrin was detected on the surface of both CRFK and MEK cells, suggesting that the interference of viral infection may be attributed to lactoferrin binding to the surfaces of susceptible cells, thereby preventing the attachment of the virus particles. Lactoferricin B, a cationic antimicrobial peptide derived from the N-terminal domain of bovine lactoferrin, reduced FCV but not PV infection.

CONCLUSION

Lactoferrin was shown to interfere with the infection of cells for both FCV and PV. However, lactoferricin B showed no interference of infection with PV and interference with infection for FCV required the presence of lactoferricin B together with the cell line and virus.

SIGNIFICANCE AND IMPACT OF THE STUDY

An in vitro basis is provided for the effects of bovine lactoferrin and lactoferricin B in moderating food-borne infections of enteric viruses.

Presynaptic failure of neuromuscular transmission and synaptic remodeling in EA2

OBJECTIVE

To further investigate the basis of abnormal neuromuscular transmission in two patients with congenital myasthenic syndrome associated with episodic ataxia type 2 (EA2) using stimulated single fiber EMG (SFEMG) and in vitro microelectrode studies.

METHODS

Two patients with genetically characterized EA2 previously shown to have abnormal neuromuscular transmission by voluntary SFEMG were studied with stimulated SFEMG and anconeus muscle biopsy with microelectrode studies and electron microscopy of the neuromuscular junction.

RESULTS

In vivo stimulated SFEMG showed signs of presynaptic failure, with jitter and blocking that improved with increased stimulation frequency. Additional evidence of presynaptic failure was provided by the in vitro microelectrode studies, which showed marked reduction of the end plate potential quantal content in both patients. Of note, the end plate potentials showed high sensitivity to N-type blockade with omega-conotoxin not seen in controls. The ultrastructural studies revealed some evidence of small nerve terminals apposed to normal or mildly overdeveloped postsynaptic membranes, suggesting an ongoing degenerative process.

CONCLUSIONS

The authors demonstrated presynaptic failure of neurotransmission in patients with heterozygous nonsense mutations in CACNA1A. The contribution of non-P-type calcium channels to the process of neurotransmitter release in these patients likely represents a compensatory mechanism, which is insufficient to restore normal neuromuscular transmission.

The Bcl-2 family pro-apoptotic molecule, BNIP3 regulates activation-induced cell death of effector cytotoxic T lymphocytes

BNIP3 is a recently described pro-apoptotic member of the Bcl-2 family and in BNIP3 cDNA-transfected cell lines, cell death occurs via a caspase-independent pathway with opening of the mitochondrial permeability transition (PT) pore and rapid loss of mitochondrial transmembrane potential (Delta psi m). However, its expression or function in physiologic cell types is not known. Our results using the T-cell receptor transgenic mice P14, specific for lymphocyte choreomeningitis virus (LCMV) glycoprotein, show that in contrast to the other Bcl-2 family pro-apoptotic molecules, BNIP3 is transcriptionally highly up-regulated in effector cytotoxic T lymphocytes (CTL). Because CTL have a propensity to undergo activation-induced cell death (AICD) upon restimulation, we tested for other features associated with BNIP3-induced cell death. AICD of CTL was caspase-independent as determined by measuring caspase activation during target cell killing as well as by lack of inhibition with caspase inhibitors. Moreover, similar to BNIP3-induced cell death, CTL apoptosis was associated with increased production of reactive oxygen species and decreased Delta psi m. Finally, retroviral transduction of BNIP3 antisense RNA diminished AICD in effector CTL. These results suggest that BNIP3 may play an important role in T-cell homeostasis by regulating effector CTL numbers.

Loss-of-function EA2 mutations are associated with impaired neuromuscular transmission

OBJECTIVE

To examine the functional consequences of episodic ataxia type 2 (EA2)-causing nonsense and missense mutations in vitro and to characterize the basis of fluctuating weakness in patients with E2A.

BACKGROUND

Mutations in CACNA1A encoding the Ca(v)2.1 calcium channel subunit cause EA2 through incompletely understood mechanisms. Although the Ca(v)2.1 subunit is important for neurotransmission at the neuromuscular junction, weakness has not been considered a feature of EA2.

METHODS

The disease-causing mutations in three unrelated patients with EA2 and fluctuating weakness were identified by mutation screening and sequencing. Mutant constructs harboring mutations R1281X, F1406C, R1549X were transfected into COS7 cells and expressed for patch clamp studies. Single-fiber electromyography (SFEMG) was performed in patients to examine synaptic transmission at the neuromuscular junction.

RESULTS

Functional studies in COS7 cells of nonsense and missense EA2 mutants demonstrated markedly decreased current densities compared with wild type. SFEMG demonstrated jitter and blocking in these patients with EA2, compared with normal subjects and three patients with SCA-6.

CONCLUSION

EA2-causing missense and nonsense mutations in CACNA1A produced mutant channels with diminished whole cell calcium channel activity in vitro due to loss of function. Altered biophysical properties or reduced efficiency of plasma membrane targeting of mutant channels may contribute to abnormal neuromuscular transmission, manifesting as myasthenic syndrome.

[Anatomy structures of nasal cavity and paranasal sinus on virtual endoscopy and coronal image]

OBJECTIVE

To evaluate normal and bony anatomy of nasal cavity and paranasal sinus on the spiral CT virtual endoscopy(VE) and coronal scanning image.

METHOD

After patients were scanned on axial or coronal position by spiral CT, data were transferred to workstation. Structures such as ostium-meatal complex(OMC) were viewed by navigator software when threshold was changing.

RESULT

Turbinates, meatus and ostium-meatal complex were better viewed by virtual endoscopy compared with by coronal scanning image. To some extent, bony anatomy was clearer.

CONCLUSION

Virtual endoscopy is of value in realizing characteristics of nasal cavity and paranasal sinus anatomy.

Effector differentiation is not prerequisite for generation of memory cytotoxic T lymphocytes

The lineage relationship between short-lived effector T cells and long-lived memory cells is not fully understood. We have described T-GFP mice previously, in which naive and early activated T cells express GFP uniformly, whereas cells that have differentiated into effector cytotoxic T cells selectively lose GFP expression. Here we studied antigen-specific CD8 T cell differentiation using T-GFP mice crossed to the TCR transgenic (Tg) mice P14 (specific for the lymphocytic choriomeningitis virus glycoprotein peptide, gp33-41). After activation with antigenic peptide, P14XT-GFP CD8(+) T cells cultured in high-dose IL-2 developed into cells with effector phenotype and function: they were blastoid, lost GFP expression, expressed high levels of activation and effector markers, and were capable of immediate cytotoxic function. In contrast, cells cultured in IL-15 or low-dose IL-2 never developed into full-fledged effector cells. Rather, they resembled memory cells: they were smaller, were GFP(+), did not express effector markers, and were incapable of immediate cytotoxicity. However, they mediated rapid-recall responses in vitro. After adoptive transfer, they survived in vivo for at least 10 weeks and mounted a secondary immune response after antigen rechallenge that was as potent as endogenously generated memory cells. In addition to providing a simple means to generate memory cells in virtually unlimited numbers, our results suggest that effector differentiation is not a prerequisite for memory cell generation.

[The relationship between plasma tumor necrosis factor alpha levels and complications after allogeneic bone marrow transplantation]

OBJECTIVE

To ascertain the implication of tumor necrosis factor alpha (TNF alpha) in the pathogenesis of acute graft-versus-host disease (aGVHD).

METHODS

Plasma TNF alpha levels were assessed by ELISA in 243 sera samples from 40 patients who had undergone allogeneic bone marrow transplantation (BMT). Plasma TNF alpha levels were measured before BMT and at different time points after BMT. The results were correlated with aGVHD, infection and conditioning regimen.

RESULTS

Plasma TNF alpha levels were significantly higher in patients with grade II and grades III-IV aGVHD (0-4.90) micrograms/L and (0.25-4.21) micrograms/L, respectively than in those with grade 0 or I aGVHD, but there was no clear correlation between plasma TNF alpha levels in patients with grade II and grade III-IV aGVHD. Plasma TNF alpha levels in patients with infection were not statistically different from those in patients without infection. The conditioning regimen did not cause a significant rise in TNF alpha levels.

CONCLUSION

It is indicated that TNF alpha may be useful for the diagnosis of aGVHD and for differentiation between aGVHD and other BMT related complications such as infection.

Proteomic analysis of apoptosis initiation induced by all-trans retinoic acid in human acute promyelocytic leukemia cells

The irreversible destiny of apoptosis in its early stage might play a critical role in the apoptosis of human acute promyelocytic leukemia (APL) cell line induced by all-trans retinoic acid (ATRA). To characterize protein alterations during the apoptosis-initiation phase and to understand the metabolic status at that time, we investigated the protein profiles in the apoptosis-initiation phase of APL cell line HL-60 by proteomic analysis. ATRA-withdrawal was conducted to demonstrate that there was committed initiation phase of apoptosis triggered by 10(-6) M ATRA at day 3. Only after that time point, ATRA-treated cells irreversibly went to apoptosis. Also at that time point, the positive regulators of apoptosis such as STAT3 increased at protein level, whereas negative regulators (Bcl-2 and p-STAT3) decreased. In addition, caspase-3 also increased after that time. Furthermore, comparative proteomic analysis was utilized to examine the protein expression profiles during the initiation stage of apoptosis. Our results showed 12 upregulated and 7 downregulated proteins experiencing twofold alteration, including key regulators of signal transduction such as G-proteins and nucleic receptors, proteins related with metabolism, oxidation and reduction, proteins associated with the nucleus and cytoskeleton-related proteins. Some of them could be positive modulators to trigger apoptosis, whereas others could contribute to intracellular defense against apoptosis induced by exogenous triggers. The results above suggest that there is a subtle balance between apoptosis and the intracellular defense against apoptosis. Once the balance is disturbed, cells would irreversibly initiate to undergo the execution of apoptosis.

Gene expression profiling in human fetal liver and identification of tissue- and developmental-stage-specific genes through compiled expression profiles and efficient cloning of full-length cDNAs

Fetal liver intriguingly consists of hepatic parenchymal cells and hematopoietic stem/progenitor cells. Human fetal liver aged 22 wk of gestation (HFL22w) corresponds to the turning point between immigration and emigration of the hematopoietic system. To gain further molecular insight into its developmental and functional characteristics, HFL22w was studied by generating expressed sequence tags (ESTs) and by analyzing the compiled expression profiles of liver at different developmental stages. A total of 13,077 ESTs were sequenced from a 3'-directed cDNA library of HFL22w, and classified as follows: 5819 (44.5%) matched to known genes; 5460 (41.8%) exhibited no significant homology to known genes; and the remaining 1798 (13.7%) were genomic sequences of unknown function, mitochondrial genomic sequences, or repetitive sequences. Integration of ESTs of known human genes generated a profile including 1660 genes that could be divided into 15 gene categories according to their functions. Genes related to general housekeeping, ESTs associated with hematopoiesis, and liver-specific genes were highly expressed. Genes for signal transduction and those associated with diseases, abnormalities, or transcription regulation were also noticeably active. By comparing the expression profiles, we identified six gene groups that were associated with different developmental stages of human fetal liver, tumorigenesis, different physiological functions of Itoh cells against the other types of hepatic cells, and fetal hematopoiesis. The gene expression profile therefore reflected the unique functional characteristics of HFL22w remarkably. Meanwhile, 110 full-length cDNAs of novel genes were cloned and sequenced. These novel genes might contribute to our understanding of the unique functional characteristics of the human fetal liver at 22 wk.

[Quantitative assay of metabolic rate of para-aminobenzoic acid combining glycine for the assessment of rabbit liver function]

OBJECTIVE

To evaluate liver function by the assessment of the capacity of glycine combining para-aminobenzoic acid (PABA) to form hippuric acid in rabbits with acute liver injury.

METHODS

Thirty rabbits were randomly divided into two groups: experiment group (n=20) received D-galactosamine to be subject to acute liver necrosis, and control group (n=10) received saline as placebo. Serum concentrations of PABA, para-aminohippuric acid (PAHA), para-acetamidobenzoic acid (PAABA), and para-acetamidohippuric acid (PAAHA) were measured by high pressure liquid chromatography (HPLC).

RESULTS

Compared with control group, the serum concentrations of PAHA and PAAHA were significantly reduced in experimental group, which were correlated with the degree of liver injury.

CONCLUSIONS

The metabolic rate of glycine combining PABA is a sensitive index for quantitative test of liver function and assessment of acute liver necrosis.

Chromium diffusion and reduction in soil aggregates

The distribution of metal contaminants such as chromium in soils can be strongly localized by transport limitations and redox gradients within soil aggregates. Measurements of Cr(VI) diffusion and reduction to Cr(III) were obtained in soil columns representing transects into soil aggregates in order to quantify influences of organic carbon (OC) and redox potentials on Cr transport distances and microbial community composition. Shifts in characteristic redox potentials, and the extent of Cr(VI) reduction to Cr(III) were related to OC availability. Depth profiles of Cr(VI, III) obtained with micro X-ray absorption near edge structure (micro-XANES) spectroscopy reflected interdependent effects of diffusion and spatially dependent redox potentials on reduction kinetics and microbial community composition. Shallow diffusion depths (2-10 mm) and very sharply terminated diffusion fronts in columns amended with OC (80 and 800 ppm) reflected rapid increases in Cr reduction kinetics over very short (mm) distances. These results suggest that Cr contamination in soils can be restricted to the outsides of soil aggregates due to localized transport and rapid reduction and that bulk sample characterization is inadequate for understanding the controlling biogeochemical processes.

Proteomic characterization of early-stage differentiation of mouse embryonic stem cells into neural cells induced by all-trans retinoic acid in vitro

Embryonic stem (ES) cells are totipotent stem cells, which can differentiate into various kinds of cell types, including neurons. They are widely used as a model system for investigating mechanisms of differentiation events during early mouse development. In this study, proteomic techniques were used to approach the protein profile associated with the early-stage differentiation of ES cells into neuronal cells induced by all-trans retinoic acid (ATRA) in vitro. In comparison of the protein profile of parent ES cells with that of ES-derived neural-committed cells, which was induced by ATRA for four days, 24 differentially displayed protein spots were selected from two-dimensional electrophoresis (2-DE) gels for further protein identification by pepide mass fingerprinting (PMF). Nine proteins were known to being involved in the process of neural differentiation and/or neural survival. Of those, alpha-3/alpha-7 tubulin and vimentin were down-regulated, while cytokeratin 8, cytokeratin 18, G1/S-special cyclin D2, follistatin-related protein, NEL protein, platelet-activating factor acetylhydrolase IB alpha-subunit, and thioredoxin peroxidase 2 were upregulated during differentiation of ES cells to neural cells. Additionally, other 12 protein (five upregulated and seven downregulated) spots associated with ES cell differentiation into neuronal cells were not matched to known proteins so far, implicating that they might be novel proteins. The results above indicated that the molecular mechanisms of differentiation of ES cells to neural cells in vitro might be similar to those of other neural systems in vitro and identified that proteomic analysis is an effective strategy to comprehensively unravel the regulatory network of differentiation.

Serum TNFalpha levels in patients with acute graft-versus-host disease after bone marrow transplantation

Tumor necrosis factor alpha (TNFalpha) has been implicated in the pathogenesis of graft-versus-host disease (GVHD). In this study, serum levels of TNFalpha were assessed by ELISA in 243 sera samples from 40 patients who had undergone allogeneic bone marrow transplantation (BMT). Serum TNFalpha levels were measured before BMT and at different time points after BMT. The results were correlated with acute GVHD (aGVHD), infection and conditioning regimen. Serum TNFalpha levels were significantly higher in patients with grades II-IV aGVHD than in those with grade 0 or I aGVHD, but there was no clear correlation between serum TNFalpha and severity of aGVHD. Serum TNFalpha levels in infected patients were not statistically different from those in patients without infection. The conditioning regimen did not cause a significant rise in TNFalpha levels. These results indicate that TNFalpha may be useful for the diagnosis of aGVHD and for differentiating between aGVHD and other BMT-related complications, such as infection.

[Clinical features of acute myocardial infarction in the young and middle-aged patients: analysis of 68 cases of coronary artery angiography]

OBJECTIVE

This study was to evaluate the clinical features of acute myocardial infarction (AMI) in young and middle-aged patients.

METHODS

Eighty-seven patients were classified into two groups according to the age. Among them, 61 patients were 60 years old and above, 26 patients below 50 year old. Selective coronary artery angiography was performed on 68 cases and a scoring method which reflects the extent of narrowing of coronary artery was also used.

RESULTS

The older group had more risk factors than the young group. The angina pectoris in the young group was less than the older group. The incidence of acute heart failure in the young group was higher than the older group. The mortality of both two groups had no significant differences.

CONCLUSION

The high risk of AMI in the young and middle-aged patients should be paid more attention in the clinic.

[A multiple variable analysis about the risk factors of breast cancer in women]

A comprehensive investigation to the risk factors of breast cancer was carried out in 146 pairs of women subjects, with the method of 1:1 matched case-control study, and of logistic regression analysis and principal component analysis. As a result, a regression equation which includes 5 independent variables has been established by logistic regression analysis; Ten principal components were extracted from 22 risk factors of breast cancer through principal component analysis, and the cumulative contribution of variances of the 10 principal components is 64.8%. The result combining the mono-factor analysis and the multiple variables analysis indicated that the principal risk factors of breast cancer are cadre occupation, the age of primiparity and late marriage, more intake of salted meat and sausage, passive smoking, having the history of family tumor, of breast benign tumor, and of the mastadenitis; but the more number of giving births, longer period of time of lactation, more vegetable intake, and taking more vitamin may have preventive effect for breast cancer.

Removal of uranium(VI) from contaminated sediments by surfactants

Uranium(VI) sorption onto a soil collected at the Melton Branch Watershed (Oak Ridge National Laboratory, TN) is strongly influenced by the pH of the soil solution and, to a lesser extent, by the presence of calcium, suggesting specific chemical interactions between U(VI) and the soil matrix. Batch experiments designed to evaluate factors controlling desorption indicate that two anionic surfactants, AOK and T77, at concentrations ranging from 60 to 200 mM, are most suitable for U(VI) removal from acidic soils such as the Oak Ridge sediment. These surfactants are very efficient solubilizing agents at low uranium concentrations: ca. 100% U(VI) removal for [U(VI)]o,sorbed = 10(-6) mol kg-1. At greater uranium concentrations (e.g., [U(VI)]o,sorbed = ca. 10(-5) mol kg-1), the desorption efficiency of the surfactant solutions increases with an increase in surfactant concentration and reaches a plateau of 75 to 80% of the U(VI) initially sorbed. The most probable mechanisms responsible for U(VI) desorption include cation exchange in the electric double layer surrounding the micelles and, to a lesser extent, dissolution of the soil matrix. Limitations associated with the surfactant treatment include loss of surfactants onto the soil (sorption) and greater affinity between U(VI) and the soil matrix at large soil to liquid ratios. Parallel experiments with H2SO4 and carbonate-bicarbonate (CB) solutions indicate that these more conventional methods suffer from strong matrix dissolution with the acid and reduced desorption efficiency with CB due to the buffering capacity of the acidic soil.

[Relationship between soluble Fas ligand levels and complications after allogeneic bone marrow transplantation]

OBJECTIVE

To evaluate the implications of soluble Fas ligand (sFasL) in acute graft-versus-host disease (aGVHD) and discriminating symptoms of aGVHD from those of infection.

METHODS

Plasma levels of sFasL were assessed in 84 plasma samples from 13 patients after allogeneic BMT using a sandwich enzyme-linked immunological assay (ELISA). Plasma sFasL levels of the patients before BMT and at different time points in the post-BMT period were measured. The results were analysed for correlation with aGVHD and infections.

RESULTS

Plasma sFasL levels were significantly higher in patients with grade II - IV aGVHD than that in those with grade 0 - I aGVHD (P = 0.02). There was no statistic difference in plasma sFasL levels between the infectious and non-infectious patients. In the seven grade II - IV aGVHD patients, the plasma sFasL levels pre-BMT were much lower than that in the six grade 0 - I aGVHD patients.

CONCLUSIONS

sFasL may be useful for the diagnosis of aGVHD and for differentiating aGVHD from other BMT related complications. The high level of plasma sFasL pre-BMT may be of importance in decreasing the occurrence of aGVHD after BMT.

Apoptosis of PC12 cells by 4-hydroxy-2-nonenal is mediated through selective activation of the c-Jun N-terminal protein kinase pathway

Cytotoxic lipid peroxides such as 4-hydroxy-2-nonenal (HNE) are produced when cells are exposed to toxic chemicals. However, the mechanism by which HNE induces cell death has been poorly understood. In this study, we investigated the molecular mechanism of HNE-induced apoptosis in PC12 cells by measuring the activities of the mitogen-activated protein (MAP) kinases involved in early signal transduction pathways. Within 15-30 min after HNE treatment, c-Jun N-terminal protein kinase (JNK) was maximally activated, before returning to control level after 1 h post-treatment. In contrast, activities of extracellular signal regulated kinase (ERK) and p38 MAP kinase remained unchanged from their basal levels. SEK1, an upstream kinase of JNK, was also activated (phosphorylated) within 5 min after HNE treatment and remained activated for up to 60 min. Marked activation of the JNK pathway through SEK1 was demonstrated by the transient transfection of cDNA for wild type SEK1 and JNK into COS-7 cells. Furthermore, significant reductions in JNK activation and HNE-induced cell death were observed when the dominant negative mutant of SEK1 was co-transfected with JNK. Pretreatment of PC12 cells with a survival promoting agent, 8-(4-chlorophenylthio)-cAMP, prevented both the HNE-induced JNK activation and apoptosis. Nonaldehyde, a nontoxic aldehyde, caused neither apoptosis nor JNK activation. Pretreatment of PC12 cells with SB203580, a specific inhibitor of p38 MAP kinase, had no effect on HNE-induced apoptosis. All these data suggest that the HNE-mediated apoptosis of PC12 cells is likely to be mediated through the selective activation of the SEK1-JNK pathway without activation of ERK or p38 MAP kinase.