The chemokine CXCL6 restricts human trophoblast cell migration and invasion by suppressing MMP-2 activity in the first trimester

STUDY QUESTION

Can the chemokine CXCL6 affect trophoblast cell migration and invasion in human first-trimester placenta?

SUMMARY ANSWER

Chemokine CXCL6 inhibits trophoblast cell migration and invasion by suppressing matrix metalloproteinase (MMP)-2 activity in human first-trimester placenta.

WHAT IS KNOWN ALREADY

Several chemokines including CXCL8, CXCL12, CXCL14, CXCL16, CX3CL1, CCL14 and CCL4 can promote or inhibit trophoblast cell migration and invasion in human first-trimester placenta.

STUDY DESIGN, SIZE, DURATION

We used the trophoblast cell line HTR8/SVneo cells, primary trophoblast cells and villi explants to investigate the effect of rhCXCL6 on trophoblast cell migration and invasion.

PARTICIPANTS/MATERIALS, SETTING, METHODS

First, the CXCL6 RNA transcript level was detected in HTR8/SVneo cells derived from human first-trimester, second-trimester and third-trimester placenta by RT-PCR. Protein expression of CXCL6 and its receptors was tested in first-trimester placenta by immunohistochemistry. Secreted CXCL6 protein was detected in HTR8/SVneo cell supernatants by enzyme-linked immunosorbent assay. Secondly, the effect of rhCXCL6 on HTR8/SVneo cell proliferation was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Thirdly, the effect of rhCXCL6 on cell migration and invasion of HTR8/SVneo cells, primary trophoblast cells and villi explants was tested by transwell migration and invasion assays, respectively. Last, MMP-2 and MMP-9 activity in the supernatants of HTR8/SVneo and primary trophoblast cells treated by rhCXCL6 in the invasion assay was assessed by gelatin zymography.

MAIN RESULTS AND THE ROLE OF CHANCE

Abundance of the CXCL6 RNA transcript increased with pregnancy development. CXCL6 and its receptor were expressed in several cells at the human maternal-fetal interface. RhCXCL6 inhibited trophoblast cell migration and invasion by suppressing MMP-2 activity.

LIMITATIONS, REASONS FOR CAUTION

These experiments are only in vitro.

WIDER IMPLICATIONS OF THE FINDINGS

According to the literature, CXCL6 could promote tumour cell migration and invasion by accelerating MMP-9 activity. However, CXCL6 inhibited trophoblast cell migration and invasion by suppressing MMP-2 activity in human first-trimester interface. These data suggest that strict regulation of CXCL6 is required for normal migration and invasion of cells, such as those involved at the maternal-fetal interface.

Reliability and validity of the overactive bladder symptom score in Hong Kong Chinese

OBJECTIVE

To validate the Hong Kong Chinese translation of the Overactive Bladder Symptom Score questionnaire (OABSS-HKC).

DESIGN

Cross-sectional study.

SETTING

Five urology clinics of different regional hospitals in Hong Kong.

PARTICIPANTS

The Overactive Bladder Symptom Score questionnaire was translated and culturally adapted for Hong Kong Chinese, according to the Principles of Good Practice for the Translation and Cultural Adaptation Process for Patient-Reported Outcomes Measures. Chinese-speaking patients with overactive bladder symptoms were recruited from five urology clinics. The patients completed the OABSS-HKC, a 3-day micturition diary, International Prostate Symptom Scores, and the Patient Perception of Bladder Condition questionnaires (visit 1), and again after a 2-week interval (visit 2). Test-retest reliability was evaluated by the intraclass correlation coefficient and weighted Kappa coefficient. The relationship between OABSS-HKC total scores and items in the comparison measures was evaluated using Spearman's correlation coefficients.

RESULTS

The OABSS-HKC was successfully translated and culturally adapted. Fifty-one patients completed the validation study. A high level of reliability was observed between the OABSS-HKC total score answered at visit 1 and 2 for all subjects (intraclass correlation coefficient, 0.82) and among the four items answered (weighted Kappa coefficients, 0.57-0.75). The OABSS-HKC total score correlated significantly with numbers of micturitions, incontinence and urgency episodes recorded in the 3-day micturition diary, as well as the total International Prostate Symptom Scores and the Patient Perception of Bladder Condition score. However, the OABSS-HKC total score was not significantly associated with nocturia episodes, total voided volume, or number of pads used.

CONCLUSIONS

The OABSS-HKC total scores are reliable and moderately valid for the quantitative evaluation of overactive bladder symptoms in Hong Kong Chinese-speaking adults.

D2 lymphadenectomy can disseminate tumor cells into peritoneal cavity in patients with advanced gastric cancer

We sought to determine the dissemination of gastric cancer cells before and after radical D2 surgery and to determine the effectiveness of EIPL in preventing post-operative peritoneal metastasis. 64 patients were recruited with advanced gastric cancer for our final analysis. Complete curative gastrectomy with D2 lymphadenectomy was performed on the 64 patients. Before surgery, peritoneal lavage fluid was collected for cytological analysis by cell smearing and immunohistochemistry to detect disseminated cancer cells (S1). Following tumor and lymph node resection, peritoneal lavage fluid was collected for cytological examination (S2). The patients were treated by extensive intra-operative peritoneal lavage (EIPL) with normal saline (n = 31) or distilled water (n = 33). The peritoneal lavage fluid was collected for cytological examination (S3). At S1 stage, 18 patients (28.1%) were positive for disseminated cancer cells in their abdominal fluid. After D2 lymphadenectomy, 34 patients (53.1%) had disseminated cancer cells in their abdominal fluid at stage S2, which indicated that the D2 lymphadenectomy caused in an additional 16 (16/46, 34.8%) patients positive for disseminated cancer cells. After EIPL with either normal saline or distilled water at the S3 stage), all the patients were negative for disseminated cancer cells in their abdominal fluid. A total of six patients died, and four patients had recurrencent cancer. These findings indicate that D2 lymphadenectomy can disseminate gastric cancer cells, and post-operative lavage of the abdominal cavity can eliminate cancer cell dissemination and decrease the risk of peritoneal metastasis.

Expression of pigment epithelium-derived factor in human cutaneous appendages

BACKGROUND

Pigment epithelium-derived factor (PEDF), a 50-kDa glycoprotein and a member of the serine protease inhibitor gene family, is well known as a potent endogenous inhibitor of angiogenesis. However, the expression of PEDF in human cutaneous appendages has not yet been determined.

AIM

To investigate the expression of PEDF in human cutaneous appendages.

METHODS

Immunohistochemical staining was used to detect the expression of PEDF in human cutaneous appendages. Reverse transcriptase PCR, western blotting and indirect immunofluorescence were used to determine the mRNA and protein expression of PEDF on cells of the outer root sheath (ORS). A wound-healing assay was used to determine the effect of different concentrations of PEDF on the migration of ORS cells.

RESULTS

PEDF was expressed in the hair follicle (including epidermal matrix, inner root sheath, ORS and fibrous root sheath), sebaceous glands and eccrine sweat glands. Both protein and RNA expression of PEDF was detected, and expression was localized to both cytoplasm and nucleus of ORS cells. Both interleukin (IL)-4 and IL-17 at 25 ng/mL upregulated the expression of PEDF of ORS cells, with IL-4 having the greater effect. PEDF 50 ng/mL decreased migration of ORS cells.

CONCLUSIONS

PEDF is expressed in human cutaneous appendages and may play a modulatory role in the physiology of ORS cells.

SLICC/ACR damage index independently associated with left ventricular diastolic dysfunction in patients with systemic lupus erythematosus

Left ventricular (LV) diastolic dysfunction has been reported in both active and inactive systemic lupus erythematosus (SLE) patients without clinical evidence of cardiovascular disease. However, the relationship between the long-term inflammatory burden reflected by the SLICC/ACR damage index and LV diastolic function has not been studied. Eighty-two SLE patients and 82 controls matched for age, sex, body mass index, blood pressure and heart rate underwent echocardiography with tissue Doppler imaging (TDI). LV diastolic function was estimated by the myocardial early diastolic velocity (E') at the lateral annulus. There were 51 patients (62.2%) with nephritis, 23 patients (28.0%) with hypertension, 21 patients (25.6%) with vasculitis, 16 patients (19.5%) with pulmonary hypertension, 4 patients (4.9%) with cerebrovascular disease and 2 patients (2.4%) with diabetes mellitus. Sixty-two patients (75.6%) were taking prednisone and 35 patients (42.7%) used a immunosuppressant. Forty-five patients (54.8%) had active disease and suffered from disease-related end-organ damage. Patients with SLICC/ACR damage index ≥1 had more evidence of LV diastolic dysfunction with lower lateral annulus E' (9.6 ± 3.4 vs 12.9 ± 3.5 cm/s, p < 0.001) than those without. In addition, the proportion of patients with abnormal LV myocardial relaxation (defined as lateral E' < 10.0 cm/s) (51.1% vs 16.2%, χ(2) = 10.8, p = 0.001) were significantly higher. Multivariate analysis showed that the SLICC/ACR damage index ≥1 was independently associated with LV diastolic dysfunction (OR = 3.80, 95%CI: 1.21-11.95, p = 0.023) after adjusting for hypertension, disease duration and medical therapy. This may suggest that the overall inflammatory burden in SLE, as reflected by SLICC/ACR damage index, is associated with the development of diastolic dysfunction in SLE patients.

HrpZ harpins from different Pseudomonas syringae pathovars differ in molecular interactions and in induction of anion channel responses in Arabidopsis thaliana suspension cells

HrpZ, a type three secretion system helper protein from the plant-pathogen Pseudomonas syringae, can be recognized by many plants as a defence elicitor. Responses of Arabidopsis thaliana suspension cells to different HrpZ variants were studied by electrophysiological methods and cell death assay. Purified HrpZ originating from a compatible pathogen P. syringae pv. tomato DC3000 (HrpZ(Pto)) and incompatible P. syringae pv. phaseolicola (HrpZ(Pph)) both promoted Arabidopsis cell death. As an early response, both HrpZ variants induced an increase in time dependent K(+) outward rectifying current. In contrast, the effects of HrpZ proteins on anion currents were different: HrpZ(Pph) had no effect, and HrpZ(Pto) induced an anion current increase. This suggests that the observed responses of the K(+) channels and anion channels resulted from different and separable interactions and that the interaction implied in anion current modulation is host-specific. HrpZ(Pto) and HrpZ(Pph) also had a different sequence preference in phage display screen for peptide-binding. These peptides presumably represent a part of a putative target protein in the host, and HrpZ proteins of different P. syringae pathovars might have different binding specificities to match the allelic variation between plant species. Supporting the idea that the peptide-binding region of HrpZ is important for interactions with host cell components, we found that a mutation in that region changed the anion channel response of Arabidopsis cells.

Optimally enhanced optical emission in laser-induced breakdown spectroscopy by combining spatial confinement and dual-pulse irradiation

In laser-induced breakdown spectroscopy (LIBS), a pair of aluminum-plate walls were used to spatially confine the plasmas produced in air by a first laser pulse (KrF excimer laser) from chromium (Cr) targets with a second laser pulse (Nd:YAG laser at 532 nm, 360 mJ/pulse) introduced parallel to the sample surface to re-excite the plasmas. Optical emission enhancement was achieved by combing the spatial confinement and dual-pulse LIBS (DP-LIBS), and then optimized by adjusting the distance between the two walls and the interpulse delay time between both laser pulses. A significant enhancement factor of 168.6 for the emission intensity of the Cr lines was obtained at an excimer laser fluence of 5.6 J/cm(2) using the combined spatial confinement and DP-LIBS, as compared with an enhancement factor of 106.1 was obtained with DP-LIBS only. The enhancement mechanisms based on shock wave theory and reheating in DP-LIBS are discussed.

Quantum dot-based nanocomposites for biomedical applications

Quantum dot (QD) has been extensively investigated as a nanoprobe to replace conventional organic dyes due to its unique optical properties. However, nanotoxicity of QD greatly hampers its biomedical applications, particularly in in vivo imaging. It is critical to functionalize QD and/or composite QD with other functional materials for biocompatibility, multifunction and expanded applications. In this review, advances of QD-based nanocomposites are addressed with emphasis of their synthesis, fundamental understanding and applications in biosensor, multimodal imaging, drug delivery, diagnostics and cancer therapy. Some specific QD-based bionanosystems and future development directions are also discussed.

Selective Upregulation of Brain-Derived Neurotrophic Factor (BDNF) Transcripts and BDNF Direct Induction of Activity Independent N-Methyl-D-Aspartate Currents in Temporal Lobe Epilepsy Patients with Hippocampal Sclerosis

Brain-derived neurotrophic factor (BDNF) plays a critical role in many aspects of neuronal biology and hippocampal physiology and pathology, and has been implicated as a potential therapeutic target in temporal lobe epilepsy (TLE). BDNF total mRNA and its six transcripts were compared in the hippocampal tissue of TLE patients with or without hippocampal sclerosis (HS) by real-time fluorescence quantitative polymerase chain reaction. Excitatory actions induced by BDNF on hippocampal cells were investigated by whole-cell patch-clamp recordings. Statistically significant increases in three human BDNF mRNA transcripts were observed in TLE patients with HS compared with those without HS (transcripts 2, 3 and 5 exhibited 2.1-, 2.3-and 4.1-fold increases, respectively); there were no significant increases in other transcripts. BDNF directly induced N-methyl-d-aspartate currents in dentate granule cells of TLE patients with HS. These results demonstrated that BDNF transcripts were selectively upregulated in TLE patients with HS compared with those without HS. Moreover, BDNF induced excitability of dentate granule cells in TLE patients with HS.

Enhancement of optical emission from laser-induced plasmas by combined spatial and magnetic confinement

To enhance optical emission in laser-induced breakdown spectroscopy, both a pair of permanent magnets and an aluminum hemispherical cavity (diameter: 11.1 mm) were used simultaneously to magnetically and spatially confine plasmas produced by a KrF excimer laser in air from pure metal and alloyed samples. High enhancement factors of about 22 and 24 in the emission intensity of Co and Cr lines were acquired at a laser fluence of 6.2 J/cm2 using the combined confinement, while enhancement factors of only about 11 and 12 were obtained just with a cavity. The mechanism of enhanced optical emission by combined confinement, including shock wave in the presence of a magnetic field, is discussed. The Si plasmas, however, were not influenced by the presence of magnets as Si is hard to ablate and ionize and hence has less free electrons and positive ions. Images of the laser-induced Cr and Si plasmas show the difference between pure metallic and semiconductor materials in the presence of both a cavity and magnets.

Generation of high-temperature and low-density plasmas for improved spectral resolutions in laser-induced breakdown spectroscopy

Improved spectral resolutions were achieved in laser-induced breakdown spectroscopy (LIBS) through generation of high-temperature and low-density plasmas. A first pulse from a KrF excimer laser was used to produce particles by perpendicularly irradiating targets in air. A second pulse from a 532 nm Nd:YAG laser was introduced parallel to the sample surface to reablate the particles. Optical scattering from the first-pulse plasmas was imaged to elucidate particle formation in the plasmas. Narrower line widths (full width at half maximums: FWHMs) and weaker self-absorption were observed from time-integrated LIBS spectra. Estimation of plasma temperatures and densities indicates that high temperature and low density can be achieved simultaneously in plasmas to improve LIBS resolutions.

Measurement of w-InN/h-BN Heterojunction Band Offsets by X-Ray Photoemission Spectroscopy

X-ray photoelectron spectroscopy has been used to measure the valence band offset (VBO) of the w-InN/h-BN heterojunction. We find that it is a type-II heterojunction with the VBO being -0.30 ± 0.09 eV and the corresponding conduction band offset (CBO) being 4.99 ± 0.09 eV. The accurate determination of VBO and CBO is important for designing the w-InN/h-BN-based electronic devices.

Multifunctional CuO nanowire devices: p-type field effect transistors and CO gas sensors

We report the properties of a field effect transistor (FET) and a gas sensor based on CuO nanowires. CuO nanowire FETs exhibit p-type behavior. Large-scale p-type CuO nanowire thin-film transistors (10(4) devices in a 25 mm(2) area) are fabricated and we effectively demonstrate their enhanced performance. Furthermore, CuO nanowire exhibits high and fast response to CO gas at 200 degrees C, which makes it a promising candidate for a poisonous gas sensing nanodevice.

Evolution of the clock from yeast to man by period-doubling folds in the cellular oscillator

Analysis of genome-wide oscillations in transcription reveals that the cell is an oscillator and an attractor and that the maintenance of a stable phenotype requires that maximums in expression in clusters of transcripts must be poised at antipodal phases around the steady state-this is the dynamic architecture of phenotype. Plots of the path through concentration phase space taken by all of the transcripts of Saccharomyces cerevisiae yield a simple three-dimensional surface. How this surface might change as period lengthens or as a cell differentiates is at the center of current work. We have shown that changes in gene expression in response to mutation or perturbation by drugs occur through a folding or unfolding of the surface described by this circle of transcripts and we suggest that the path from this 40-minute oscillation to the cell cycle and circadian rhythms takes place through a series of period-two or period-three bifurcations. These foldings in the surface of the putative attractor result in an increasingly dense set of nested trajectories in the concentrations of message and protein. Evolutionary advantage might accrue to an organism that could change period by changes in just one or a few genes as day length increased from 4 hours in the prebiotic Earth, through 8 hours during the expansion of photoautotrophs, to the present 24 hours.

Improving interval estimation of binomial proportions

In this paper, we propose one new confidence interval for the binomial proportion; our interval is based on the Edgeworth expansion of a logit transformation of the sample proportion. We provide theoretical justification for the proposed interval and also compare the finite-sample performance of the proposed interval with the three best existing intervals-the Wilson interval, the Agresti-Coull interval and the Jeffreys interval-in terms of their coverage probabilities and expected lengths. We illustrate the proposed method in two real clinical studies.

Effect of inhaled formaldehyde on learning and memory of mice

In this study, we investigated the effect of inhaled formaldehyde on learning and memory capacity. After exposure to 0 (control), 1 and 3 mg/m(3) of gaseous formaldehyde respectively, the behavior of mice in a Morris water maze, the expression of NR1, NR2B mRNA and oxidative damage levels in mice brain were analyzed. The water maze performance, the activities of dismutase superoxide (SOD) and levels of glutathione (GSH) decreased significantly in 3 mg/m(3) group (P < 0.01, compared with control group); while malondialdehyde (MDA) contents and expression of NR1 and NR2B genes increased significantly after exposure to 3 mg/m(3) of gaseous formaldehyde (P < 0.05, <0.01, <0.01, compared with control group). These findings indicate that inhaled formaldehyde negatively affects learning and memory at 3 mg/m(3) of gaseous formaldehyde but not at lower levels. Oxidative stress-induced neuron damages in the brain may be the possible mechanism for these effects.

PRACTICAL IMPLICATIONS

This study indicates that inhaled formaldehyde starts to negatively affect learning and memory at a middle concentration of formaldehyde without interference of other indoor air pollutants. Oxidative damage, and the alteration of NMDA receptor expression, which were induced by formaldehyde inhalation, may be the possible mechanism for gaseous formaldehyde-induced neurotoxicity.

Continuous veno-venous haemofiltration attenuates myocardial mitochondrial respiratory chain complexes activity in porcine septic shock

Increasing evidence indicates that mitochondrial dysfunction plays an important role in modulating the development of septic shock. In the present study, we investigated whether continuous veno-venous haemofiltration (CVVH) with high-volume might improve myocardial mitochondrial dysfunction in a porcine model of peritonitis-induced septic shock. Sixteen male Landrace pigs weighing 31 +/- 5 kg were randomly assigned to normal control group (n = 4), peritonitis group (n = 6) and peritonitis plus CVVH group (n = 6). All animals were anaesthetised and mechanically ventilated. After baseline examinations, the peritonitis group and the peritonitis plus CVVH group underwent induction of peritonitis. One hour later, the animals in the peritonitis plus CVVH group received treatment with high-volume CVVH. Twelve hours after treatment, the animals were sacrificed. Animals in the peritonitis group were killed 13 hours after induction of peritonitis. Peritonitis challenge induced septic shock associated with increased blood lactate and high-volume CVVH improved lactate acidosis. Compared with the peritonitis group, cardiac output, stroke volume and mean arterial pressure were better maintained in peritonitis plus CVVH group. More importantly, high-volume CVVH improved myocardial mitochondrial complex I activity (0.22 +/- 0.03 vs. 0.15 +/- 0.04, P = 0.04). These results suggest that high-volume CVVH improves haemodynamics and heart dysfunction in septic shock and the improvement may be attributed to amelioration of myocardial mitochondrial dysfunction.

Construction and characterization of two bacterial artificial chromosome libraries of pea (Pisum sativum L.) for the isolation of economically important genes

Pea (Pisum sativum L.) has a genome of about 4 Gb that appears to share conserved synteny with model legumes having genomes of 0.2-0.4 Gb despite extensive intergenic expansion. Pea plant inventory (PI) accession 269818 has been used to introgress genetic diversity into the cultivated germplasm pool. The aim here was to develop pea bacterial artificial chromosome (BAC) libraries that would enable the isolation of genes involved in plant disease resistance or control of economically important traits. The BAC libraries encompassed about 3.2 haploid genome equivalents consisting of partially HindIII-digested DNA fragments with a mean size of 105 kb that were inserted in 1 of 2 vectors. The low-copy oriT-based T-DNA vector (pCLD04541) library contained 55 680 clones. The single-copy oriS-based vector (pIndigoBAC-5) library contained 65 280 clones. Colony hybridization of a universal chloroplast probe indicated that about 1% of clones in the libraries were of chloroplast origin. The presence of about 0.1% empty vectors was inferred by white/blue colony plate counts. The usefulness of the libraries was tested by 2 replicated methods. First, high-density filters were probed with low copy number sequences. Second, BAC plate-pool DNA was used successfully to PCR amplify 7 of 9 published pea resistance gene analogs (RGAs) and several other low copy number pea sequences. Individual BAC clones encoding specific sequences were identified. Therefore, the HindIII BAC libraries of pea, based on germplasm accession PI 269818, will be useful for the isolation of genes underlying disease resistance and other economically important traits.

Spectral power distribution and quantum yields of Sm3+-doped heavy metal tellurite glass under the pumping of blue lighting emitting diode

Quantum yields for multichannel transition emissions have been determined in Sm3+-doped heavy metal tellurite glass under the pumping of blue lighting emitting diode for the first time. To achieve this goal, the necessary fluorescence spectra were measured and calibrated in an integrating sphere, which was connected to a CCD detector with a 400 microm-core optical fiber. The spectral power distribution of the sample under the blue LED pumping was derived from the measured spectra firstly, and then the quantum yields for the visible emissions of Sm3+ were calculated based on the distribution and the total quantum yields in visible region is 7.55%. For accurate measurements, integrating sphere method is proved to be a reliable and reproducible way to characterize luminescence and laser materials.

Exciton dissociation in organic light emitting diodes at the donor-acceptor interface

Experimental in situ photoluminescence and transient photovoltage results show that the interface formed by N, N{'}-Bis(naphthalene-1-yl)-N, N{'}-bis(phenyl) benzidine (NPB) and tris(8-hydroxyquinoline) aluminum (Alq{3}) acts as an exciton dissociation site. Because of this dissociation effect, excitons formed in NPB at or within a diffusion length of the interface tend to dissociate before they radiatively decay to generate blue light. This suggests that the action of the "hole-blocking layer" used in indium tin oxide\NPB\hole-blocking layer\Alq{3}\aluminium to promote blue light emission from the NPB is more "exciton dissociation inhibition" than "hole blocking."

Performance of silicon nanocrystal non-volatile memory devices under various programming mechanisms

Non-volatile memory devices based on silicon nanocrystal synthesized with very low energy Si+ implantation are fabricated. Memory performance under various programming mechanisms including Fowler-Nordheim (FN), drain-bias channel-hot-electron (DCHE), and source-bias channel-hot-electron (SCHE) has been investigated. It is observed that the DCHE yields the largest memory window among the three programming mechanisms. The DCHE and SCHE have similar endurance characteristics, but the SCHE has a longer retention time than the DCHE. Both the DCHE and SCHE have a larger memory window, a better endurance and a longer retention time as compared to the FN. Explanations to the phenomena are given.

Sensitive electrochemical enzyme immunoassay microdevice based on architecture of dual ring electrodes with a sensing cavity chamber

A novel electrochemical detection architecture was investigated for enzyme immunoassay sensors. Microchips with dual-ring working and counter electrodes, and a sensing cavity chamber were made on glass slides. The glass surface of the microchip was coated by 3-aminopropyltriethoxysilane (APTES). Goat IgG, as a example, was covalently captured on APTES-modified glass surfaces through glutaraldehyde (GA) as a cross-linker. Enzyme substrate, p-aminophenyl phosphate (PAPP) was prepared by electrolysis. The enzyme conversion from home-synthetic PAPP to p-aminophenol (PAP) was examined by differential pulse voltammetry (DPV). A competitive inhibition enzyme-linked immunosorbant assay (ELISA) was designed to test the system. Experimental results demonstrate that a detection limit of 118 fg/ml of goat IgG and a dynamic range of 118 fg/ml to 1.18 ng/ml, up to five orders of magnitude could be achieved. Due to its novel architecture design and electronic detection scheme, the method can be used to fabricate portable electrochemical ELISA lab-on-chip systems. The technology could have great potential in clinical diagnostic applications.

Changes in the expression of Fas on T lymphocytes after allogeneic fetal thymus transplantation in systemic lupus erytematosus mice

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disorder that can produce inflammation in many organ systems. The rate of spontaneous apoptosis in lymphocytes from human SLE patients has been reported to be increased both in vivo and in vitro. Studies of fetal thymus transplantation in an autoimmune syndrome indicate that cellular immunity can be reconstituted and regulatory T cell functions can be normalized.

OBJECTIVES

The aim of this study was to assess changes in Fas expression on T lymphocytes following fetal thymus transplant.

METHODS

(B/CxB6) F1 (H-2d/h) female F1 mice were assigned to groups designated transplantation, normal, and control. Mice in the transplantation and control groups received parental BALB/c lymphocytes intravenously. Thirty days after injection of the lymphocytes, each F1 mouse in the transplantation group received a fetal thymus graft under the right renal capsule. Mice in the control group did not receive thymus transplant and mice in the normal group received neither parental lymphocytes nor a fetal thymus graft. All mice received cyclosporin A at 2 mg/kg daily for the first 12 days after transplantation or starting on the corresponding day. Thirty days after thymus transplantation, F1 mice were sacrificed and expression of Fas in peripheral blood lymphocytes was analyzed by flow cytometry.

RESULTS

The percentage of CD4Fas+ T lymphocytes was significantly increased in the control group and the transplantation group compared with the normal group. Corresponding significant differences were observed for CD8Fas+, CD4CD25Fas', and CD45RB(low)Fas+ T lymphocytes.

CONCLUSIONS

In this study, we found that fetal thymus transplantation had a significant effect on the expression of Fas by T cell subtypes in SLE mice.

Type II vanilloid receptor signaling system: one of the possible mechanisms for the rise in asthma cases

The prevalence of asthma keeps on increasing worldwide, especially in western societies over last 40 years. The mechanism of asthma is unclear. Recently, concern about indoor air pollution as a risk factor for asthma has been arisen. In present study, 25 Kun Ming male mice were placed in an air chamber containing respective formaldehyde (FA) concentration of 0, 0.5, 1.0, 3.0 mg/m3,and 3.0 mg/m3 with Capsazepine (CPZ, a specific antagonist of vanilloid receptor)-pretreatment in five testing groups (n=5 per group) for inhale experiments. The inhaled groups were exposed to gaseous FA for 6 hours each day in 10 successive days. After exposure, the concentrations of IL4 in blood serum and broncho alveolar lavage fluid (BALF) were measured. Experimental results showed that the IL4 level in serum was too low to be detected; and the concentrations of IL4 in BALF increased in a dose-dependent manner. However, for the CPZ-pretreated group the IL4 level in BALF decreased significantly (compared with 3.0 mg/m3 FA inhaled group, p<0.01). This paper describes experimental animal methods to probe IL4 level, an important indicator for IgE response. The studies in this paper indicated that gaseous FA might induce acquired atopy by type II VR1 signaling system. These findings suggested that indoor air pollutants such as FA might be key risk factors for the rise in asthma cases, and type II VR1 signaling system might be one of the mechanisms for the rise.