Gene association analysis to determine the causal relationship between immune cells and juvenile idiopathic arthritis

BACKGROUND

Juvenile idiopathic arthritis (JIA) is a type of chronic childhood arthritis with complex pathogenesis. Immunological studies have shown that JIA is an acquired self-inflammatory disease, involving a variety of immune cells, and it is also affected by genetic and environmental susceptibility. However, the precise causative relationship between the phenotype of immune cells and JIA remains unclear to date. The objective of our study is to approach this inquiry from a genetic perspective, employing a method of genetic association analysis to ascertain the causal relationship between immune phenotypes and the onset of JIA.

METHODS

In this study, a two-sample Mendelian randomization (MR) analysis was used to select single nucleotide polymorphisms (SNPs) significantly associated with immune cells as instrumental variables to analyze the bidirectional causal relationship between 731 immune cells and JIA. There were four types of immune features (median fluorescence intensity (MFI), relative cellular (RC), absolute cellular (AC), and morphological parameters (MP)). Finally, the heterogeneity and horizontal reproducibility of the results were verified by sensitivity analysis, which ensured more robust results.

RESULTS

We found that CD3 on CM CD8br was causally associated with JIA at the level of 0.05 significant difference (95% CI = 0.630 ~ 0.847, P = 3.33 × 10-5, PFDR = 0.024). At the significance level of 0.20, two immunophenotypes were causally associated with JIA, namely: HLA DR on CD14+ CD16- monocyte (95% CI = 0.633 ~ 0.884, P = 6.83 × 10-4, PFDR = 0.16) and HLA DR on CD14+ monocyte (95% CI = 0.627 ~ 0.882, P = 6.9 × 10-4, PFDR = 0.16).

CONCLUSION

Our study assessed the causal effect of immune cells on JIA from a genetic perspective. These findings emphasize the complex and important role of immune cells in the pathogenesis of JIA and lay a foundation for further study of the pathogenesis of JIA.

[The mechanism of S100A7 inducing the migration and invasion in cervical cancer cells]

Objective: To investigate the mechanism of S100A7 inducing the migration and invasion in cervical cancers. Methods: Tissue samples of 5 cases of cervical squamous cell carcinoma and 3 cases of adenocarcinoma were collected from May 2007 to December 2007 in the Department of Gynecology of the Affiliated Hospital of Qingdao University. Immunohistochemistry was performed to evaluate the expression of S100A7 in cervical carcinoma tissues. S100A7-overexpressing HeLa and C33A cells were established with lentiviral systems as the experimental group. Immunofluorescence assay was performed to observe the cell morphology. Transwell assay was taken to detect the effect of S100A7-overexpression on the migration and invasion of cervical cancer cells. Reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) was used to examine the mRNA expressions of E-cadherin, N-cadherin, vimentin and fibronectin. The expression of extracellular S100A7 in conditioned medium of cervical cancer cell was detected by western blot. Conditioned medium was added into Transwell lower compartment to detect cell motility. Exosomes were isolated and extracted from the culture supernatant of cervical cancer cell, the expressions of S100A7, CD81 and TSG101 were detected by western blot. Transwell assay was taken to detect the effect of exosomes on the migration and invasion of cervical cancer cells. Results: S100A7 expression was positively expressed in cervical squamous carcinoma and negative expression in adenocarcinoma. Stable S100A7-overexpressing HeLa and C33A cells were successfully constructed. C33A cells in the experimental group were spindle shaped while those in the control group tended to be polygonal epithelioid cells. The number of S100A7-overexpressed HeLa cells passing through the Transwell membrane assay was increased significantly in migration and invasion assay (152.00±39.22 vs 105.13±15.75, P<0.05; 115.38±34.57 vs 79.50±13.68, P<0.05). RT-qPCR indicated that the mRNA expressions of E-cadherin in S100A7-overexpressed HeLa and C33A cells decreased (P<0.05) while the mRNA expressions of N-cadherin and fibronectin in HeLa cells and fibronectin in C33A cells increased (P<0.05). Western blot showed that extracellular S100A7 was detected in culture supernatant of cervical cancer cells. HeLa cells of the experimental group passing through transwell membrane in migration and invasion assays were increased significantly (192.60±24.41 vs 98.80±47.24, P<0.05; 105.40±27.38 vs 84.50±13.51, P<0.05) when the conditional medium was added into the lower compartment of Transwell. Exosomes from C33A cell culture supernatant were extracted successfully, and S100A7 expression was positive. The number of transmembrane C33A cells incubated with exosomes extracted from cells of the experimental group was increased significantly (251.00±49.82 vs 143.00±30.85, P<0.05; 524.60±52.74 vs 389.00±63.23, P<0.05). Conclusion: S100A7 may promote the migration and invasion of cervical cancer cells by epithelial-mesenchymal transition and exosome secretion.

Causal roles of daytime sleepiness in cardiometabolic diseases and osteoporosis

OBJECTIVE

Daytime sleepiness has some association with cardiometabolic diseases and osteoporosis, but it is unknown whether their relationship is causal. This two-sample Mendelian randomization (MR) study aims to explore their causal relationship.

MATERIALS AND METHODS

We included the largest genome-wide association studies (GWASs) associated with daytime sleepiness, cardiometabolic diseases and osteoporosis. 34 single nucleotide polymorphisms (SNPs) were used as the instrumental variables of daytime sleepiness.

RESULTS

Genetic predisposition to excessive daytime sleepiness was strongly associated with increased risk of coronary artery disease (beta-estimate: 0.610, 95% confidence interval [CI]: 0.128 to 1.093, standard error [SE]: 0.246, p-value=0.013) and may increase the incidence of type 2 diabetes (beta-estimate: 0.614, 95% CI: 0.009 to 1.219, SE: 0.309, p-value=0.047). We found no causal influence of daytime sleepiness on heart failure, atrial fibrillation, cerebral ischemia, intracerebral hemorrhage, forearm bone mineral density (FA-BMD), femoral neck BMD (FN-BMD), and lumbar spine BMD (LS-BMD).

CONCLUSIONS

This study suggested that excessive daytime sleepiness was causally associated with increased risk of coronary artery disease, which may benefit to prevent this disease.

High-Efficiency Arbitrary Quantum Operation on a High-Dimensional Quantum System

The ability to manipulate quantum systems lies at the heart of the development of quantum technology. The ultimate goal of quantum control is to realize arbitrary quantum operations (AQUOs) for all possible open quantum system dynamics. However, the demanding extra physical resources impose great obstacles. Here, we experimentally demonstrate a universal approach of AQUO on a photonic qudit with the minimum physical resource of a two-level ancilla and a log_{2}d-scale circuit depth for a d-dimensional system. The AQUO is then applied in a quantum trajectory simulation for quantum subspace stabilization and quantum Zeno dynamics, as well as incoherent manipulation and generalized measurements of the qudit. Therefore, the demonstrated AQUO for complete quantum control would play an indispensable role in quantum information science.

Experimental Implementation of Universal Nonadiabatic Geometric Quantum Gates in a Superconducting Circuit

Using geometric phases to realize noise-resilient quantum computing is an important method to enhance the control fidelity. In this work, we experimentally realize a universal nonadiabatic geometric quantum gate set in a superconducting qubit chain. We characterize the realized single- and two-qubit geometric gates with both quantum process tomography and randomized benchmarking methods. The measured average fidelities for the single-qubit rotation gates and two-qubit controlled-Z gate are 0.9977(1) and 0.977(9), respectively. Besides, we also experimentally demonstrate the noise-resilient feature of the realized single-qubit geometric gates by comparing their performance with the conventional dynamical gates with different types of errors in the control field. Thus, our experiment proves a way to achieve high-fidelity geometric quantum gates for robust quantum computation.

A new adaptation for in vitro co-culture of single porcine parthenogenetic embryos using feeder cells

Feeder cells can promote cell proliferation and help overcome the developmental arrest of early embryos by producing growth factors. The objective of this study was to evaluate the effects of feeder cells on the development of all single porcine parthenogenetic embryos in vitro. Firstly, we showed that the cleavage and blastocyst formation rate of all single procine parthenogenetic embryos co-cultured with feeder cells increased in contrast to those cultured without feeder cells (p⟨0.05). However, no statistically significant differences were observed between the blastocyst formation rate in the embryos co-cultured with 3 different kinds feeder cells namely oviduct epithelial feeder cells, granulose feeder cells and porcine fetal fibroblast feeder cells (p>0.05). Secondly, highly significant differences were observed between the cleavage and blastocyst formation rate (p⟨0.05) when the embryos were co-cultured with oviduct epithelial feeder cells in different volume drops ranging from 3 to 20 μL and the cleavage rate were the highest when cultured in 5 μL drops. Thirdly, the tempospacial pattern of the development of single embryos co-cultured with oviduct epithelial feeder cells was consistent with that of traditional multi-embryo culture, indicating that the co-culturing does not affect the developmental competence of the porcine parthenogenetic embryos. Finally, highly significant differences were observed between the cleavage and blastocyst formation rate with and without zona pellucida in vitro (p⟨0.05). In this study, a new adaption of in vitro co-culture of single porcine parthenogenetic embryos using feeder cells has been successfully established and this will facilitate further investigations to discover the mechanistic mode of developmental arrest of porcine embryos.

Knockdown of microRNA-181a inhibits osteosarcoma cells growth and invasion through triggering NLRP3-dependent pyroptosis

OBJECTIVE

This study aimed to investigate the physiological function and molecular mechanism of microRNA-181a (miRNA-181a) in the carcinogenesis of osteosarcoma.

MATERIALS AND METHODS

The relative expression of miRNA-181a in tissues and cultured cells was detected by quantitative real time-polymerase chain reaction (qRT-PCR). MiR-181a inhibitor and miR-181a mimics were used to manipulate its level in cells. Cell proliferation and invasion were measured using Cell Counting Kit-8 (CCK-8) assay and transwell assay, respectively. The protein levels of the targeted genes were detected by Western blotting and immunohistochemistry. Terminal Deoxynucleotidyl Transferase (TdT)-mediated dUTP Nick-End Labeling (TUNEL) assay was employed to detect cell apoptosis. Moreover, a xenograft tumor bearing mice model was used to evaluate the effect of miR-181a in vivo.

RESULTS

We found that miRNA-181a was aberrantly elevated in osteosarcoma tissues and cells. Moreover, the overexpression of miRNA-181a could facilitate cell proliferation and migration. By contrast, miRNA-181a knockdown reverses these effects. Additionally, downregulation of miRNA-181a could activate NOD-like receptor protein 3 (NLRP3)-dependent pyroptosis, as evidenced by the increase of pyroptosis-related genes (NLRP3, caspase-1, interleukin-18, and interleukin-1β) in miRNA-181a inhibitor transfected cells compared with the control. Further mechanistic studies identified that miRNA-181a knockdown suppresses cell proliferation and invasion by activating NLRP3-dependent pyroptosis. Silencing NLRP3 could effectively reverse the effects mediated by miRNA-181a inhibitor. Consistently, in vitro results also demonstrated that blockade of miRNA-181a notably suppresses tumor growth via activating pyroptosis.

CONCLUSIONS

These results provide that miRNA-181a might serve as potential therapeutic target for osteosarcoma patients.

CO2 concentration affects in vitro pig embryo developmental capacity

Culture gas atmosphere is one of the most important factors affecting embryo development in vitro. The main objective of this study was to compare the effects of CO concentration on the subsequent pre-implantation developmental capacity of pig embryos in vitro, including embryos obtained via parthenogenesis, in vitro fertilization (IVF), and intracytoplasmic sperm injection (ICSI). Pig embryos were developed in four different CO2 concentrations in air: 3%, 5%, 10%, or 15%. The cleavage rate of pig parthenogenetic, IVF, or ICSI embryos developed in CO2 concen- trations under 5% was the highest. There were no significant differences in the oocyte cleavage rate in ICSI embryos in CO2 concentrations under 3% and 5% (p>0.05). However, as CO2 levels increased (up to 15%) the blastocyst output on day 7, from parthenogenetic, IVF, and ICSI em- bryos, decreased to 0%. These findings demonstrate that CO2 positively affects the developmen- tal capacity of pig embryos. However, high or low CO2 levels do not significantly improve the developmental capacity of pig embryos. The best results were obtained for all of the pig embryos at a 5% CO2 concentration.

Attenuated Salmonella VNP20009 mutant (ΔhtrA) is a promising candidate for bacteria-mediated tumour therapy in hosts with TNFR1 deficiency

VNP20009 is a genetically modified strain of Salmonella typhimurium and has a good anticancer effect wildly used in tumour therapy on animal models. For its clinical application, an accurate bio-safety assessment on sensitive models is necessary. In this study, we use TNFR1 KO mice as a susceptive model to assess the virulence of bacterial VNP20009 and its derivative ΔhtrA. By intraperitoneal administration of Salmonella, the increased lethality was observed in TNFR1 KO mice infected with VNP20009, but not with ΔhtrA. We performed a systemically comparative analysis of their toxicity, and ΔhtrA shows a better bio-safety for TNFR1 KO mice. Since the macrophages with TNFR1 deficiency exhibit a reduced ability of bacteria clearance, ΔhtrA with lower survival ability in normal macrophages restores its viability in TNFR1 KO macrophages. Thus, ΔhtrA was further tested for its antitumour effect in TNFR1 KO mice bearing a B16F10 melanoma model. It displays a moderate antitumour effect, suggesting ΔhtrA instead of VNP20009 might be a promising candidate for bacteria-mediated tumour therapy specific to those with low immunity.

SIGNIFICANT AND IMPACT OF THE STUDY

VNP20009 is attenuated Salmonella with a good safety widely used for tumour-targeting bacterial therapies. Little is known about its toxicity in hosts with low immunity. This study is the first systemically comparative analysis of their toxicity of VNP20009 and its mutant ΔhtrA in TNFR1-KO mice. Research on toxicity of tumour-targeting Salmonella in mice with immunodeficiency can facilitate the optimization of bacterial therapies with reduced adverse effects in future clinical trials.

[S100A7 promotes the metastasis and epithelial-mesenchymal transition on HeLa and CaSki cells]

Objective: To elucidate the impact of over-expression of S100A7 on migration, invasion, proliferation, cell cycle, and epithelial-mesenchymal transition (EMT) in human cervical cancer HeLa and CaSki cells. Methods: (1) Immunohistochemistry of SP was used to examine the expression of S100A7 in 40 cases of squamous cervical cancer tissues and 20 cases of normal cervical tissues. (2) The vectors of pLVX-IRES-Neo-S100A7 and pLVX-IRES-Neo were used to transfect human cervical cancer HeLa and CaSki cells, and the positive clones were screened and identified. Next, transwell migration assay, cell counting kit-8 (CCK-8) assay and fluorescence activating cell sorter (FACS) were used to detect the effect of S100A7-overexpression on the migration, invasion, proliferation and cell cycle of cervical cancer cells. Furthermore, western blot was performed to observe the expression of epithelial marker (E-cadherin) and mesenchymal markers (N-cadherin, vimentin, and fibronectin) of EMT. Results: (1) S100A7 expression was significantly higher in cervical squamous cancer tissues (median 91.6) than that in normal cervical tissues (median 52.1; Z=-2.948, P=0.003) . (2) Stable S100A7-overexpressed cells were established using lentiviral-mediated gene delivery in HeLa and CaSki cells. S100A7 was detected by real-time quantitative reverse transcription PCR, S100A7 mRNA of S100A7-overexpressed cells were 119±3 and 177±16, increased significantly compared with control groups of median (P<0.01) . Compared with the control cells, the number of S100A7-overexpressed HeLa and CaSki cells that passed the transwell membrane assay were increased significanatly (572±51 vs 337±25, P<0.01; 100±8 vs 41±4, P<0.01) .Matrigel invasion assay showed that the number of S100A7-overexpressed HeLa and CaSki cells that passed the transwell membrane were respectively 441±15 and 110±14, elevated significantly compared with control cells (156±21 and 59±7; P<0.05) . However, S100A7 overexpression didn't influence the proliferation and cell cycle progression of HeLa and CaSki cells (P>0.05) . Expression of E-cadherin was dramatically decreased, while N-cadherin, vimentin, and fibronectin increased in S100A7-overexpressed cells. Conclusion: S100A7 enhances the migration, invasion and EMT of HeLa cells and CaSki cells, and may be plays an important role in the development of cervical cancer.

A protective role for FADD dominant negative (FADD-DN) mutant in trinitrochlorobenzene (TNCB)-induced murine contact hypersensitivity reactions

BACKGROUND

Fas-associated protein with death domain (FADD) is a classic adaptor protein in apoptosis. Increasing evidence has shown that FADD is also implicated in T-cell development, activation and proliferation. The role of FADD in inflammatory disorders remains largely unexplored.

AIM

To assess the role of FADD in inflammatory disorders.

METHODS

We established an experimental model of contact hypersensitivity (CHS) by using 2,4,6-trinitrochlorobenzene (TNCB) on transgenic mice expressing a dominant negative mutant of FADD (FADD-DN), RESULTS: CHS responses were clearly attenuated in FADD-DN mice compared with control mice. In the retroauricular lymph nodes, the ratio of CD8+ T cells was also decreased.

CONCLUSION

FADD-DN appears to play a protective role in TNCB-induced CHS reactions.

Constraints on cosmic strings from the LIGO-Virgo gravitational-wave detectors

Cosmic strings can give rise to a large variety of interesting astrophysical phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by cusps are a promising observational signature. In this Letter we present a search for GWs from cosmic string cusps in data collected by the LIGO and Virgo gravitational wave detectors between 2005 and 2010, with over 625 days of live time. We find no evidence of GW signals from cosmic strings. From this result, we derive new constraints on cosmic string parameters, which complement and improve existing limits from previous searches for a stochastic background of GWs from cosmic microwave background measurements and pulsar timing data. In particular, if the size of loops is given by the gravitational backreaction scale, we place upper limits on the string tension Gμ below 10(-8) in some regions of the cosmic string parameter space.

Adenosine 5'-monophosphate ameliorates D-galactosamine/lipopolysaccharide-induced liver injury through an adenosine receptor-independent mechanism in mice

D-galactosamine (GalN)/lipopolysaccharide (LPS)-induced lethality and acute liver failure is dependent on endogenously produced inflammatory cytokines. Adenosine has been proven to be a central role in the regulation of inflammatory response. It is not entirely clear that which adenosine action is actually crucial to limiting inflammatory tissue destruction. Here we showed that GalN/LPS challenge elevated hepatic adenosine and induced lethality in adenosine receptor-deficient mice with equal efficiency as wild-type mice. In GalN/LPS-treated mice, pretreatment with adenosine 5'-monophosphate (5'-AMP) significantly elevated hepatic adenosine level and reduced mortality through decreasing cytokine and chemokine production. In RAW264.7 cells, 5'-AMP treatment inhibited the production of inflammatory cytokines, which is not mediated through adenosine receptors. 5'-AMP failed to attenuate LPS-induced nuclear factor-κB (NF-κB) p65 nuclear translocation, but reduced LPS-induced recruitment of NF-κB p65 to inflammatory gene promoters and decreased LPS-induced enrichment of H3K4 dimethylation at the tumor necrosis factor-α (TNF-α) promoter, which was involved in 5'-AMP-induced elevation of cellular adenosine and a decline of methylation potential. In vitro biochemical analysis revealed that adenosine directly attenuated recruitment of NF-κB to the TNF-α and interleukin-6 promoters. Our findings demonstrate that 5'-AMP-inhibiting inflammatory response is not mediated by adenosine receptors and it may represent a potential protective agent for amelioration of LPS-induced liver injury.

Evaluation of CT coronary artery angiography with 320-row detector CT in a high-risk population

OBJECTIVES

The aim of this article was to prospectively evaluate the accuracy and radiation dose of 320-detector row dynamic volume CT (DVCT) for the detection of coronary artery disease (CAD) in a high-risk population.

METHODS

60 patients with a high risk of CAD underwent DVCT without preceding heart rate control and also underwent invasive coronary angiography (ICA), which served as the standard reference.

RESULTS

On a per segment analysis, overall sensitivity was 95.3%, specificity was 97.6%, positive predictive value was 90.6%, negative predictive value was 98.8% and Youden index was 0.93. In both heart rate subgroups, diagnostic accuracy for the assessment of coronary artery stenosis was similar. The accuracy of the subgroup with an Agatston score ≥100 was lower than that for patients with an Agatston score <100. However, the difference between DVCT and ICA results was not significant (p=0.08). The mean estimated effective dose of CT was 12.5 ± 9.4 mSv. In those patients with heart rates less than 70 beats per minute (bpm), the mean radiation exposure of DVCT was 5.2 ± 0.9 mSv. The effective radiation dose was significantly lower than that of ICA (14.1 ± 5.9 mSv) (p<0.001). When the heart rate was >70 bpm, a significantly higher dose was delivered to patients with DVCT (22.6 ± 5.2 mSv, p<0.001) than with ICA (15.0 ± 5.3 mSv, p<0.001).

CONCLUSION

DVCT reliably provides high diagnostic accuracy without heart rate/rhythm control. However, from a dosimetric point of view, it is recommended that heart rate should be controlled to <70 bpm to decrease radiation dose.

Therapeutic effects of anticoagulant agents on preeclampsia in a murine model induced by phosphatidylserine/phosphatidylcholine microvesicles

Preeclampsia (PE) is a placenta-mediated pregnancy complication that results in high maternal and neonatal mortality and morbidity worldwide. Currently, there is no satisfactory pharmacotherapeutic treatment to stop the PE progression. In this study, we investigated the therapeutic effects of anticoagulant agents, including annexin V, heparin, and a fusion protein of annexin V and hirudin (AND), in a murine PE model induced by intravenous injection of phosphatidylserine/phosphatidylcholine (PS/PC) microvesicles. Compared with the control pregnant animals, the pregnant mice injected with PS/PC presented PE-like symptoms, including elevated systolic blood pressure, proteinuria, and reduction of antithrombin III and blood platelets. However, the PE-like symptoms were significantly alleviated after the PS/PC-injected mice were treated with annexin V, AND, or heparin. Furthermore, fibrin deposition in the placentas in the anticoagulant treated mice was remarkably improved, compared with that in the mice injected with PS/PC alone. The data demonstrate that anticoagulants are effective to prevent the occurrence of PE in the murine model and also suggest that hypercoagulation in the placenta is a contributing factor in the pathogenesis of PE.

Treatment of Chronic Idiopathic Urticaria with Levamisole: A Multicentre, Randomized, Double-Blind, Controlled Trial

The objective of this study was to evaluate the efficacy of treating chronic idiopathic urticaria (CIU) with levamisole in combination with levocetirizine. This was a multicentre, randomized, double-blind, controlled trial that included 132 patients with active CIU who were treated for 6 weeks with either levocetirizine alone (control group; n = 65) or levamisole plus levocetirizine (treatment group; n = 67). Response to therapy was evaluated by measuring the efficacy rate. After 2 weeks of treatment, there was no significant difference in the efficacy rate between the treatment and control groups (54.84% and 42.37%, respectively). After 6 weeks of treatment, a statistically significant difference in the efficacy rate was observed between the groups (76.27% and 54.39% for the treatment and control groups, respectively). This study demonstrated that a combination of levamisole plus levocetirizine is more effective than levocetirizine alone and potentially provides a new, promising approach to the treatment of CIU.

Effect of dendritic cell vaccine against a tongue squamous cell cancer cell line (Tca8113) in vivo and in vitro

Dendritic cells (DCs), as primary antigen-presenting cells with the capacity to activate naïve T lymphocytes, are considered to be promising adjuvants for immunity against cancer. In this study, the effect of T lymphocyte-mediated immunity induced by a DC vaccine against Tca8113 cells in vivo and in vitro was evaluated. DCs were from human peripheral blood monocytes cultured in the presence of granulocyte-macrophage colony stimulating factor, interleukin 4 and/or tumour necrosis factor alpha, and stimulated with Tca8113 cell lysate prepared by the freeze-thaw method. The autologous T cells activated by these DCs were used in an in vitro MTT assay to detect their tumouricidal activity and investigated for their anti-tumour effect in vivo by administration to nude mice with implanted tumours (Tca8113). An adequate number of DCs were successfully generated from the monocytes. The T cells activated by the DC-based vaccine killed Tca8113 cells in vitro (P<0.01), postponed tumour doubling time of the implanted tumours in nude mice (P<0.01) and inhibited the growth of the tumours (P<0.05). These results show that DCs from monocytes induce a lymphocyte-mediated immune response against tongue squamous carcinoma, and could be used as a vehicle for tumour antigens.

[Exploration on statistical method for calculating intensity of the infection in residents in nationwide sampling survey of schistosomiasis]

AIM

To set up statistical methods for calculation of intensity of schistosome infection in residents in nationwide sampling survey of schistosomiasis.

METHODS

Based on the epidemiological survey of schistosomiasis and according to the medical statistics for multiple stratifying and clustering random sampling, the calculation method on intensity of schistosome infection was inferred.

RESULTS AND CONCLUSION

Nine formulas were worked out for the calculation of the intensity of schistosome infection in different endemic provinces with different ecotypes. These formulas are of practical value.

The crystal structure of bar-headed goose hemoglobin in deoxy form: the allosteric mechanism of a hemoglobin species with high oxygen affinity

The crystal structure of a high oxygen affinity species of hemoglobin, bar-headed goose hemoglobin in deoxy form, has been determined to a resolution of 2.8 A. The R and R(free) factor of the model are 0.197 and 0.243, respectively. The structure reported here is a special deoxy state of hemoglobin and indicates the differences in allosteric mechanisms between the goose and human hemoglobins. The quaternary structure of the goose deoxy hemoglobin shows obvious differences from that of human deoxy hemoglobin. The rotation angle of one alphabeta dimer relative to its partner in a tetramer molecule from the goose oxy to deoxy hemoglobin is only 4.6 degrees, and the translation is only 0.3 A, which are much smaller than those in human hemoglobin. In the alpha(1)beta(2) switch region of the goose deoxy hemoglobin, the imidazole ring of His beta(2)97 does not span the side-chain of Thr alpha(1)41 relative to the oxy hemoglobin as in human hemoglobin. And the tertiary structure changes of heme pocket and FG corner are also smaller than that in human hemoglobin. A unique mutation among avian and mammalian Hbs of alpha119 from proline to alanine at the alpha(1)beta(1 )interface in bar-headed goose hemoglobin brings a gap between Ala alpha119 and Leu beta55, the minimum distance between the two residues is 4.66 A. At the entrance to the central cavity around the molecular dyad, some residues of two beta chains form a positively charged groove where the inositol pentaphosphate binds to the hemoglobin. The His beta146 is at the inositol pentaphosphate binding site and the salt-bridge between His beta146 and Asp beta94 does not exist in the deoxy hemoglobin, which brings the weak chloride-independent Bohr effect to bar-headed goose hemoglobin.

The nuclear localization signal of zebrafish terra is located within the DM domain

Zebrafish Terra is a member of the DM domain-containing transcription factor family and is involved in somitogenesis. The other known members of this family play a role in sex differentiation across species from Caenorhabditis elegans to human. Using the green fluorescence protein-Terra fusion constructs, we have identified the nuclear localization signal (NLS) of terra by transfecting human HeLa cells. The terra NLS is located between the two intertwined zinc-binding sites of the DNA-binding domain. However, the nuclear translocation of terra is independent of the structure required for DNA binding. Mutational analysis demonstrates that basic residues K77 and R78 within the DM domain are absolutely required for the translocation of Terra into the nuclei. Sequence comparison discloses that the NLS of Terra is also present in the other known members of the DM family, indicating the conservative nature of the NLS of this family during evolution.

[Characteristics of granular sludge during start-up of the internal circulation]

The quick start-up of the laboratory scale IC reactor and the characteristics of granular sludge during start-up were studied in this paper. The results showed that the first start-up of IC reactor could be finished in 20 days, while secondary start-up only needed 15 days with COD loading rate of 12-15 kg.(m3.d)-1 and COD removal larger than 85%. During start-up, the characteristics of granular sludge changed greatly: average granular diameter was increased from 0.88 mm to 1.25 mm; average settling velocity was enhanced from 35.4 m.h-1 to 105.17 m.h-1; methanogenic activities of the granular increased up to 4 times as large as the seeded sludge; the main methanobacteria was changed from Methanothrix to Methanococcus and Methanobacterium.

Identification of a new human CYP2A gene fragment with close linkage to CYP2GP1

Human genomic libraries were screened to identify CYP2G-related cytochrome P450 genes. A genomic fragment comprising exons 7 through 9 of CYP2GP1 and exons 6 through 9 of a previously unidentified CYP2A gene, designated CYP2A7P2, was isolated from an EMBL3 library; the two genes were arranged in outward opposite directions with about 8 kbp of intervening sequence. The same structure was also detected in a bacteriophage P1 clone, which contained a full-length CYP2GP1 gene, exons 6 through 9 of CYP2A7P2, and the CYP2B7 gene. However, additional CYP2A-related exons as well as other CYP2A genes, CYP2A7P1, CYP2B6, CYP2F1, and CYP2GP2 were not detected. These results indicate that CYP2A7P2 is located near CYP2B7 in the middle of the CYP2A-2B-2F gene cluster on chromosome 19. Furthermore, an analysis of CYP2A sequence alignment suggests that CYP2A7P2 may be derived from the same ancestral gene that gave rise to CYP2A7P1, which was corrupted by a large insertion at intron 5.

A simple copper(II)-L-histidine system for efficient hydrolytic cleavage of DNA

Copper(II)-L-histidine complexes effectively promote the cleavage of plasmid DNA and dideoxynucleotide dApdA at physiological pH and temperature. Studies of the mechanism of plasmid DNA cleavage by added radical scavengers, using rigorously anaerobic experiments, analyses for malondialdehyde-like products, religation assays, and HPLC analyses, indicate that DNA cleavage mediated by Cu(L-His) occurs via a hydrolytic path. The hydrolytic cleavage rate constants at 37 degrees C are estimated to be 0.76 h-1 for the decrease of form I and 0.25 h-1 for the increase of form III. The phosphoimager picture reveals that Cu(L-His) cleaves DNA with a certain sequence specificity (preferentially at 5'-GT-3'). The dinucleotide hydrolysis shows, with [Cu(L-His)] = 0.8 mM, rate enhancement factors of > 10(8). Interestingly, histidine-metal ion interactions (with Cu(II), Ni(II), Zn(II), etc.) have been used for various applications, e.g., protein purification, cross-linking, and targeting proteins to lipid bilayers. Our findings may provide the basis for developing new applications and new ways to design more effective and useful catalysts for DNA cleavage. Cu(L-His) is one of only a few well-defined metal complexes demonstrated to hydrolytically cleave dideoxynucleotides and DNA.

Characterization of human CYP2G genes: widespread loss-of-function mutations and genetic polymorphism

CYP2G1 is an abundant, olfactory mucosa-specific cytochrome P450 enzyme active in the metabolism of sex steroids and xenobiotic substrates in mammalian animals. Two different human CYP2G genes, CYP2GP1 and CYP2GP2, were characterized in the present study. Polymorphisms in these genes were also studied. CYP2GP1 contained a single nucleotide deletion in exon 2 (deltaC) and a 2.4-kb deletion between exons 3 and 7 (deltaE4-6), whereas CYP2GP2 contained a nonsense mutation in exon 1 and another in exon 3. The coding region sequences in exons 1-3 and 7-9 of the two genes were 96.7% identical. Both genes were localized to human chromosome 19, and Southern blot analysis of human genomic DNA did not detect any additional copies of the CYP2G gene. The occurrence of these loss-of-function mutations was analysed by polymerase chain reaction-based genotyping in more than 200 individuals. The deltaE4-6 deletion in CYP2GP1 was detected in 94% of subjects (either homozygous or heterozygous), and an allele which does not contain this deletion was detected in 11.6% of individuals. The nonsense mutation in CYP2GP2 exon 3 was detected in 86% of individuals (either homozygous or heterozygous); however, a potentially functional CYP2GP2 allele based on the absence of the nonsense mutation in exon 3 was also detected in 31% of individuals. These results indicate that a functional CYP2G allele is rare in humans. Analysis of the allelic distribution in different ethnic groups suggested that a functional CYP2G allele, if present, is more likely to be found in Black and Hispanic subjects.

Phonological systems of a set of Putonghua-speaking twins

Impaired phonology is reported to be the most salient characteristic of the communication profiles of twin children. However, little is known about the phonological development of twins speaking languages other than English. This case study described the phonological systems of a set of Putonghua-speaking twins, using quantitative and qualitative measures. The analyses indicated that the phonological systems of the co-twins were not identical, though both evidenced characteristics of delayed or disordered phonological development and shared some error patterns. They comprehended both adult and their sibling's phonological forms, suggesting a dual phonological representation in their mental lexicon for some words. These results confirmed Dodd and McEvoy's (1994) research findings for English-speaking twins.

[Anatomy in relation to posterior maxillary osteotomy]

OBJECTIVE

The most common site of haemorrhage in maxillary osteotomies is the posterior maxilla. Better understanding of the anatomy of this region would minimize possible vascular complications. The aim of this study is to investigate the anatomy of posterior maxilla and establish safety guidelines for Le Fort I osteotomy.

METHOD

Thirty dry human skulls were selected for direct measurement and computerized image analysis.

RESULTS

Synosteosis of the pterygomaxillary junction was noted in 10% of the samples. The height of the pterygomaxillary junction was 13.15 mm. The height from the inferior point of the pterygomaxillary junction to the inferior point of the maxillary tuberosity was 5.25 mm. The height from the superior point of the pterygomaxillary junction to the inferior point of the maxillary tuberrosity was 18.05 mm. The average distance from the piriform rim to the descending palatine canal was 35.25 mm. The width of the pterygoid process was 12.34 mm. The average length from the zygo-alveolar ridge to the pterygomaxillary junction was 25.47 mm. The average length from anterior nasal spine to the posterior nasal spine was 46.27 mm, and the angle between the descending palatine canal and the palate plane was 58 degrees 47'.

CONCLUSIONS

The study is to provide further understanding of the posterior maxillary anatomy in relation to the bone-cut design of Le fort I osteotomy and to create clinical safety guidelines in order to avoid damaging the descending palatine vessels.

p53 mutation, EGFR gene amplification and loss of heterozygosity on chromosome 10, 17 p in human gliomas

OBJECTIVE

To further illustrate the roles of p53 gene, epidermal growth factor receptor (EGFR) gene and loss of heterozygosity (LOH) on chromosome 10 and 17 p in human glioma progression.

METHODS

p53 mutations were scanned in 50 gliomas with various malignant grades using the polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) assay, and were confirmed by direct sequencing. LOH for chromosome 10, 17 p and amplification of the EGFR gene were also assessed using Southern blot analysis.

RESULTS

p53 mutations were found in 9 of 17 high-grade astrocytomas (53%), 1 of 15 low-grade astrocytomas (7%), and the only subject of eppendymoblastoma but in none of the 10 medulloblastomas and 7 eppendymomas. The majority of gliomas (38/50) analyzed here retained both 17 p alleles. The frequency of p53 mutations was 13% in this group of tumors and increased to 50% (6/12) in tumors with one 17 p allele (P < 0.025). LOH on chromosome 10 was found in 35% (6/17) of high-grade astrocytomas, in 10% (1/10) of medulloblastomas, but in 0% of low-grade gliomas. EGFR gene amplification was found in 9 high-grade gliomas, 60% (6/9) of which also presented LOH for chromosome 10.

CONCLUSIONS

These results indicate that p53 inactivation is a common genetic event in astrocytoma progression that may be more strongly associated with the progression of astrocytomas than with their origin. Absence of p53 mutations in 50% of the tumors with one 17 p allele suggests that a tumor suppressor gene other than p53 may be located on chromosome 17 p and involved in progression to malignancy of some gliomas. The loss of alleles on chromosome 10 and the amplification of the EGFR gene appear to be restricted to high-grade tumors, suggesting that these events may be related to tumor progression rather than initiation.

[The anatomy of the pterygopalatine canal in relation to the Le Fort I osteotomy]

OBJECTIVE

The most common site of hemorrhage in maxillary osteotomies is the posterior maxilla. Better understanding of the anatomy in this region may minimize possible vascular complications. The aim of the study is to investigate the anatomy of posterior maxilla and establish safety guidelines for the Le Fort I osteotomy.

METHODS

Thirty dry human skulls were selected for direct measurement and analysis.

RESULTS

Results showed that the average distance from the piriform rim to the descending palatine canal was 35.25 mm, the average distance from the zygo-alveolar ridge to the descending palatine canal was 25.41 mm, the average distance from the descending palatine canal to the central line was 16.68 mm, the average distance from the piriform rim to the central line was 12.87 mm. The angle between the line from the piriform rim to the descending palatine canal and the central line was 6 degrees 14'.

CONCLUSIONS

The study is to provide further understanding of the posterior maxillary anatomy in relation to the bone cut design of Le Fort I osteotomy, and to create clinical safety guidelines in order to avoid damaging the descending palatine vessels.

JNK1 is inactivated during thiamine deficiency-induced apoptosis in human neuroblastoma cells

Thiamine deficiency results in selective neuronal damage. A number of mechanisms have been proposed to account for brain damage associated with thiamine deficiency and to account for the focal nature of the loss of neurons. One proposed mechanism is programmed cell death. We found efficient induction of apoptosis in human neuroblastoma cells when the cells were deprived of thiamine. Although extensive mitochondrial damage was seen, the release of cytochrome c was not the triggering mechanism for thiamine deficiency-induced apoptosis. Instead, the activity of the cJun amino terminal kinase Jnk1 was lost, and this loss correlated temporally with induction of apoptosis. The loss was specific for Jnk1; Jnk2/3 activity remained unchanged. Loss of Jnk1 activity was not found in lymphoblasts, a cell type that did not undergo apoptosis when deprived of thiamine. These findings suggest that thiamine deficiency results in a cellular stress that brings about the loss of Jnk1 activity and the loss of its function of protecting cells from programmed cell death. We postulate that focal sensitivity to thiamine deficiency results, in part, from specific neuronal cell types being susceptible to the inactivation of Jnk1 in response to depletion of cellular thiamine.

[The study of a computer aided artificial teeth arrangement of complete denture]

OBJECTIVE

To develop a system of computer aided complete denture design (CACDD).

METHODS

After 3 dimensional measurement, data process and making model of a edentulous model, artificial teeth and the maxillomandibular bite plate, on the position of centric relation, the artificial teeth were arranged according to the principle and demand of the complete denture's teeth arrangement. The relation of teeth and occlusion were adjusted by Affine and Projection transformation.

RESULTS

(1) The maxillomandibular visual base on the position of centric relation were made, its mathematics model is B-Spline curve surface of the double third power. (2) The artificial teeth arrangement and 3 dimensional show of the complete denture were achieved.

CONCLUSION

This system can provide a feasible tool for a computer aided complete denture design and teaching.

The phonological acquisition of Putonghua (Modern Standard Chinese)

The phonological acquisition of 129 monolingual Putonghua-speaking children, aged 1;6 to 4;6, is described. Putonghua (Modern Standard Chinese) syllables have four possible elements: tone, syllable-initial consonant, vowel, and syllable-final consonant. The children's errors suggested that Putonghua-speaking children mastered these elements in the following order: tones were acquired first; then syllable-final consonants and vowels; and syllable-initial consonants were acquired last. Phonetic acquisition of the 21 syllable-initial consonants was complete by 3;6 for 75% of children. By 4;6 the children were using the syllable-initial consonants correctly on two thirds of occasions (with the exception of four affricates). Simple vowels emerged early in development. However, triphthongs and diphthongs were prone to systematic errors. Tone errors were rare, perhaps because of their role in distinguishing lexical meaning. In contrast, acquisition of 'weak stress' and 'rhotacized feature' was incomplete in the oldest children assessed. Phonological processes used by the children were identified. Two of these processes, syllable-initial consonant deletion and backing, would be considered atypical error patterns in English. Existing theories of phonological acquisition (e.g. concepts of markedness, functional load, feature hierarchies) cannot account for some of the patterns revealed. A satisfactory explanation of the findings requires more attention to the specific characteristics of the linguistic system the children are learning. It is proposed that the saliency of the components in the language system determines the order of acquisition.

Mitochondrial gene variation in type 2 diabetes mellitus: detection of a novel mutation associated with maternally inherited diabetes in a Chinese family

OBJECTIVE

To explore the relationship between type 2 diabetes mellitus and the mutation(s) in mitochondrial DNA.

METHODS

According to the previous literature, the fragment of mitochondrial DNA from nucleotide 3153 to 3551, which had shown high frequency of point mutation, was scanned with the technique of polymerase chain reaction--single strand conformation polymorphism (PCR-SSCP) in Chinese normal control, type 2 diabetic population, and 12 families suffered from maternally inherited type 2 diabetes mellitus. Direct sequencing was applied to detect the fragments with abnormal conformation.

RESULTS

No special band was found in SSCP electrophoreses in Chinese normal control, and only one subject (No. 81) of diabetic population indicated the abnormality in SSCP study, which was affirmed to be a silent point mutation of T to C at nucleotide 3336 inducing no change in amino acid (ATT-->ATC, Ile). Pedigree 25,001 was the only family that exhibited strongly different SSCP characteristic from the other 11 ones, which was confirmed to be caused by a single point mutation mt3285T-->C/T in the coding region of tRNA(Leu(UUR)) gene by the technique of direct sequencing.

CONCLUSIONS

The variation within mt DNA 3153-3551 is not the major cause of type 2 diabetes in Chinese population suffered from this disease in this study. The point mutation T-->C/T at the mitochondrial nucleotide 3285, which was found in pedigree 25,001, is located in the highly conservative region of tRNA(Leu(UUR)) gene. It is strongly suggested that this mutation cause the conversion in the 3-dimentional structure of tRNA(Leu(UUR)), which might disturb the normal translation and lead to the impairment in mitochondrial oxidative phosphorylation characterized by the defects of the polypeptides involved in the respiratory chain. Thus, insulin secretion deficiency and insulin resistance might occur.

[Minimally invasive approach for heart valve replacement: report of 73 cases]

OBJECTIVE

To report a new minimally invasive approach for heart valve operation.

METHODS

Through right minimal vertical infra-axillary thoracotomy incision (by intercostal space), 68 patients with rheumatic heart disease, 2 patients with subacute endocarditis, and 3 patients with congenital heart disease underwent heart valve replacement from March 1997 to Spring 1998.

RESULTS

30 double valve replacements, 33 mitral valve replacements, 10 aortic valve replacements and 14 DeVega tricuspid annuloplasty were performed. The length of the incision averaged (8.5 +/- 0.9) cm, arrest times averaged (88.6 +/- 33.8) min, cardiopulmonary bypass times averaged (117.0 +/- 45.9) min. Five mitral valve replacements were performed with ventricular fibrillation. Ventilator periods averaged (9.6 +/- 3.6) h, chest tube drainage averaged (264.5 +/- 184.3) ml. One patient died of cerebral bleeding in hospital. Two patients suffered SBE and one of them died. The results of follow up for other patients were fine.

CONCLUSIONS

This minimally incisive valve operation is a new safe, small wounded and cosmetic approach for heart valve replacement.

[Inhibition of guan-fu base A on delayed rectifier current (Ik) in guinea pig ventricular myocytes]

Guan-fu base A (GFA) is a terpenoid alkaloid isolated from the tuber of Aconitum coreanum, which has been shown to prolong cardiac repolarization in vivo and in vitro. In the present study, the effects of GFA on the delayed rectifier current (Ik) were investigated using the whole cell patch-clamp technique in isolated guinea pig ventricular myocytes. In the presence of CdCl2 100 mumol.L-1, Ik was observed upon depolarizing pulses to +50 mV from a holding potential -40 mV for variable duration (550, 1100, 1650, 2200, 2750, 3300, 3850 ms). The magnitude of Ik after a 2200 ms pulse was 293 +/- 90 pA prior to drug and 227 +/- 59 pA in the presence of GFA 100 mumol.L-1. In a 3850 ms pulse, the magnitude of Ik decreased from 290 +/- 90 to 231 +/- 66 pA after exposure to GFA. The inhibitory effects of GFA on Ik was not dependent on the duration of depolarization. The inward rectifier current (Ik1) was not affected by GFA 100 mumol.L-1. It is concluded that GFA has inhibitory effects on Ik, which may contribute to its prolongation of cardiac repolarization.

[The mechanisms of progesterone treatment on endometrial carcinoma]

OBJECTIVE

To study the mechanisms of the exogenic progestrerone treatment on endometrial carcinoma.

METHODS

We observed the morphologic changes of the endometrial cancer cells treated by exogenic progesterone with light and electronic microscopy.

RESULTS

The main changes of the tumor cell treated were well differentiation, increase in secretory activity and apoptosis of tumor cells.

CONCLUSIONS

Progesterone may directly affect tumor cells, inhibit the growth of tumor cells and lead to well differentiation. Clinically with preoperative and postoperative progesterone therapy, it can decrease the peritoneum implantation and metastasis, and also decrease the recurrence after operation.

Fusion expression of mutated cecropin CMIV inE. coli

A cDNA coding mutated cecropin CMIV fromBombyx mori was synthesized according to its amino acid sequence usingE. coli biased codons. The gene was cloned into the fusion expression vector pEZZ318 and was expressed inE. coli HB101. The fusion protein produced was purified by affinity chromatography to yield 26 mg/L fusion product. The anti-bacterial activities of recombinant cecropin CMIV were recovered after cleavage by chemical method.

cDNA cloning, heterologous expression, and characterization of mouse CYP2G1, an olfactory-specific steroid hydroxylase

CYP2G1 is expressed specifically in the olfactory mucosa in rabbits and rats. In the present study, a full-length cDNA for mouse CYP2G1 was obtained using a PCR approach with RNA preparations from the olfactory mucosa of C57BL/6 mice. Sequence comparisons indicated that mouse CYP2G1 is highly homologous in deduced amino acid sequence to rabbit (82.4% identity) and rat CYP2G1 (94.9% identity). RNA blot and immunoblot analyses indicated that mouse CYP2G1 is expressed only in the olfactory mucosa. The coding region of the mouse CYP2G1 cDNA was cloned into a baculoviral expression vector for heterologous production of the enzyme in cultured insect cells. Heterologously expressed mouse CYP2G1 was active in a reconstituted system toward testosterone and progesterone, producing all the major metabolites detected in olfactory microsomal reactions, including 15 alpha-, 15 beta-, and 2 beta-hydroxytestosterone from testosterone and two unidentified metabolites from progesterone. Kinetic analysis indicated that mouse CYP2G1 has relatively high affinities toward the steroid substrates, with K(m) values in the micromolar range for both testosterone and progesterone. At a substrate concentration of 10 microM, microsomes of olfactory mucosa had much higher turnover numbers toward testosterone and progesterone than hepatic microsomes, consistent with the olfactory-specific expression of a high-affinity sex steroid hydroxylase. These findings will facilitate further molecular genetics studies on the biological function of CYP2G1 in a mouse model.

[Anterior segmental maxillary osteotomies (ASMO)]

Anterior segmental maxillary osteotomies (ASMO) were performed with both the Wassmund and downfracture methods in 15 patients and folloned-up regularly for 12 months The postoperative maxillary incisor edge point "Is" movements and complications were examined. The results indicated that the point "Is" movement was 1.66 +/- 0.77 mm postoperatively. No major complications occurred, The stability of anterior segmental maxillary osteotomies was found to be acceptable.