[Regulation mechanism of the quorum sensing regulator AphA on the type Ⅵ secretion system VflT6SS2 in Vibrio fluvialis]

Objective: To explore the regulation mechanism of the quorum sensing regulator AphA on the functional activity of type Ⅵ secretion system VflT6SS2 in Vibrio fluvialis. Methods: Western Blot analysis was used to detect the relative expression and secretion of VflT6SS2 signature component hemolysin-coregulated protein (Hcp) in wild type (WT), ΔaphA, and corresponding complementary strains. Quantitative reverse transcription PCR and luminescence activity assay of the promoter-lux fusion system was used to measure the mRNA expression levels and promoter activity of the VflT6SS2 core and accessory gene-cluster representative genes tssB2, hcp (tssD2) and vgrG (tssI2), and the quorum sensing regulator HapR in WT and ΔaphA strains. A point mutation experiment combined with a luminescence activity assay was used to verify the regulatory binding site of AphA in the tssD2b promoter region. Electrophoretic mobility shift assay (EMSA) was used to determine AphA binding to the hapR promoter. Results: The mRNA expression levels of tssB2, hcp(tssD2), vgrG (tssI2), and hapR as well as the protein expression and secretion levels of Hcp in ΔaphA strain, were significantly higher than those in the WT strain. The promoter activities of the VflT6SS2 core cluster, tssD2a, tssI2a, and hapR were higher in ΔaphA strain than in the WT strain, while the promoter activity of tssD2b showed the opposite trend. The promoter sequence analysis of tssD2a and tssD2b found significant differences in the region from -335 bp to -229 bp, and two potential AphA binding sites on tssD2b. The promoter activity of tssD2b decreased significantly after the point mutation of the two potential AphA binding sites. EMSA results showed that AphA binds directly to the promoter region of hapR. Conclusions: AphA indirectly inhibits the regulation of the VflT6SS2 core and accessory gene clusters at the promoter level by directly repressing the expression of hapR. AphA showed opposite regulation patterns for tssD2a and tssD2b, and AphA could positively regulate the expression of tssD2b by directly binding to the tssD2b promoter region (-335 bp to -229 bp).

Effects of gonadotropin-inhibitory hormone on testicular development and reproduction-related gene expression in roosters

Gonadotropin-inhibitory hormone (GnIH) plays a crucial role in regulating reproduction in the hypothalamus of poultry and has been intensely investigated since its discovery. This study aimed to assess the effects of GnIH on testicular development, as well as on reproduction-related hormone release and gene expression levels in roosters. The administration of exogenous GnIH resulted in a significant reduction in testis weight, testis volume and semen quality (p < 0.05). Additionally, exogenous GnIH significantly up-regulates the expression of GnIH, and down-regulates the expression of PRL (p < 0.05). GnIH application also decreased the GnRH, vasoactive intestinal peptide (VIP) and luteinizing hormone β subunit(LHβ)gene expression levels. Meanwhile, by neutralizing the effects of endogenous GnIH through immunization, testicular development on day 150 in roosters was significantly promoted. Compared to the control condition, GnIH immunization significantly down-regulated the expression of the VIP and PRL genes (p < 0.05). In conclusion, we found that exogenous GnIH treatment inhibited testicular development, reduces PRL gene expression, and suppressed reproductive performance in roosters. Conversely, GnIH immunization down-regulated VIP and PRL genes, activates the reproductive system, and promotes the reproductive activity and testicular development of roosters.

[Clinical features of SF3B1 mutation in patients with myelodysplastic syndrome with excess blasts]

Objective: To exploring the clinical features of SF3B1-mutated myelodysplastic syndrome with excess blasts (MDS-EB) and analyzing the association between SF3B1 mutation, and efficacy and prognostic significance for patients with MDS-EB. Methods: This was a retrospective case series study. The clinical data of 266 patients with MDS-EB diagnosed in the First Affiliated Hospital of Zhengzhou University between April 2016 and November 2021 were analyzed. The observed indicators included blood routine counts, mutated genes, overall response rate (ORR), overall survival (OS), progression-free survival (PFS), and leukemia-free survival (LFS). The Kaplan-Meier method was used to depict the survival curves. The Log-rank test method was equally used to compare survival across groups and performed the Cox proportional hazard regression model for prognostic analysis. Results: In 266 patients with MDS-EB, 166 (62.4%) were men, and the median age was 57 (17-81) years. Moreover, there were included 26 and 240 patients in the SF3B1-mutated and SF3B1 wild-type groups. Patients in the SF3B1-mutated group were older [median age 65 (51, 69) years vs. 56 (46, 66) years, P=0.033], had higher white blood cell (WBC) counts [3.08 (2.35, 4.78) × 10⁹/L vs. 2.13 (1.40, 3.77) × 10⁹/L], platelet (PLT) counts [122.5 (50.5, 215.0) ×10⁹/L vs. 49.0 (24.3, 100.8) × 10⁹/L], absolute neutrophil counts (ANC) [1.83 (1.01, 2.88) × 10⁹/L vs. 0.80 (0.41, 1.99) × 10⁹/L]and occurrence of DNMT3A mutation [23.1% (6/26) vs. 6.7% (16/240)] (all P<0.05). The ORR were similar in both groups after 2 and 4 cycles of therapy (P=0.348, P=1.000). Moreover, the LFS (P=0.218), PFS (P=0.179) and OS (P=0.188) were similar across the groups. Univariate Cox analysis revealed that SF3B1 mutation did not affect the prognosis of patients with MDS-EB (OS: P=0.193; PFS: P=0.184). Conclusions: Patients with SF3B1 mutation were older, with greater WBC, PLT, and ANC, and SF3B1 mutation easily co-occurred with DNMT3A mutation. From this model, there were no significant differences in efficacy and survival of MDS-EB with or without SF3B1 mutation.

[Influencing factors of suicidal ideation among men who have sex with men]

Objective: To investigate the prevalence of suicidal ideation among MSM, and to explore the influence of perceived social support and depression on suicidal ideation and the possible pathway. Methods: MSM who are ≥18 years, HIV-negative, and ever had sex with men (oral sex/anal sex) in the last year participated in is study. Cross-sectional survey and convenient sampling method were used to recruit MSM through a male social interaction platform Blued 7.5 software from December 2020 to March 2021, with a questionnaire survey. Demographic questionnaire, Perceived Social Support Questionnaire and Center for Epidemiologic Studies Depression Scale were employed to collect data. Mplus 8.3 was used for data analysis. Results: Among 1 394 eligible MSM participants, 25.7% (358/1 394) had suicidal ideation. Perceived social support could have a direct effect on suicidal ideation (β=-0.11, P=0.009), and an indirect effect on suicidal ideation through depression (β=-0.18, P<0.001). Conclusions: Suicidal ideation was found to be lower in MSM with a higher level of perceived social support and a lower level of depression. Using social media to improve MSM's perceived social support and reduce depressive symptoms might be an effective means to prevent suicidal ideation.

The Inactivated gE/TK Gene-Deleted Vaccine Against Pseudorabies Virus Type II Confers Effective Protection in Mice and Pigs

The highly virulent and antigenic variant of Pseudorabies virus (PRV) that emerged from classical Bartha-K61-vaccinated pig herds has caused substantial economic losses to the swine industry in China since 2011. A safe and more effective vaccine is most desirable. In this study, a gE/TK gene-deficient PRV, namely, HD/c, was constructed based on a PRV type II DX strain isolated from a commercial vaccine-immunized farm and the HD/c-based inactivated vaccine was formulated and evaluated for its safety, immunogenicity, and protective efficacy in mice and piglets. The resulting PRV HD/c strain has a similar growth curve to the parental DX strain. After vaccination, the inactivated HD/c vaccine did not cause any visible gross pathological or histopathological changes in the tissues of mice and piglets and provided rapid and potent protection against the challenge of the classical and variant PRVs at day 21 post-vaccination in mice. A single immunization of 10^8.5TCID₅₀ inactivated PRV HD/c strain-elicited robust immunity with high titer of neutralizing antibody and provided complete protection from the lethal challenge of PRV DX strain in piglets. These results indicated that the inactivated PRV HD/c vaccine with the deletion of gE/TK genes was a safe and effective PRV vaccine candidate for the control of PRV.

[Sustainable development roadmap of Chinese antimalarial products]

As the first country that has been certified malaria-free in the WHO Western Pacific Region for more than 3 decades, China should share its successful experiences of malaria control and provide globally recognized anti-malaria products by making full uses of its advantages in provision and production capacity of artemisinin raw materials, to fill the gaps of international demands for mosquito nets, rapid diagnostic reagents and antimalarial compounds. Increasing the investment of research and development of antimalarial products, building overseas bases for artemisinin raw material production, establishing international regulatory authority and promoting the local production of antimalarial products are needed to further promote the internationalization of Chinese antimalarial products, so as to achieve the equity and accessibility of Chinese antimalarial products in highburden regions for malaria.

Hydroxytyrosol Dimers from Medicinal Insect Blaps Rynchopetera and the in Vitro Cytotoxic Activity

The edible Blaps rynchopetera Fairmaire is widely used for its various medicinal effects. From its ethyl acetate fraction, three new hydroxytyrosol dimers, rynchopeterine H (1), rynchopeterine I (2) and trans-2-(3,4-dihydroxy-phenyl)-3-hydroxy-7-(2-hydroxyethyl)-1,4-benzdioxane (3), together with four known similar dimers were obtained by chromatography of silica gel and Sephadex LH-20. Their structures were identified by HRESIMS, 1D and 2D NMR spectra analysis. Compounds 1-4 were obtained as a mixture, and cytotoxicity screening for HepG2, Caco-2, U251, AGS, B16 and Bel-7402 cell lines showed that the mixture of compounds 1-4 exhibited significantly selective cytotoxicity and good inhibitory activity on the proliferation of mouse melanoma cells (B16) with an IC50 value of 27.37 μg·mL−1.

A comparison of prokaryote communities inhabiting sponges, bacterial mats, sediment and seawater in Southeast Asian coral reefs

In the present study, we used Illumina sequencing to explore the prokaryote communities of 17 demosponge species and how they compare with bacterial mat, sediment and seawater samples (all sampled from coral reef habitat in Taiwan and Thailand). The studied sponge species formed three clusters. Operational taxonomic unit (OTU) richness and evenness were by far highest in the sediment and bacterial mat biotopes. There were pronounced differences in OTU richness and evenness among clusters and also considerable variation among certain host species within clusters. Additionally, the relative abundance of some prokaryotic taxa also differed among clusters with Poribacteria, e.g., being recorded in all sponge species, but with very low relative abundances in species of two of the three clusters. This sponge-associated phylum was, however, recorded at relatively high mean abundance in bacterial mat samples, which also housed relatively high abundances of actinobacterial and Chloroflexi members. Our results support high microbial abundance (HMA) status of the species Aaptos lobata, Hyrtios erectus, Pseudoceratina purpurea and Xestospongia testudinaria and low microbial abundance (LMA) status of the species Acanthella cavernosa, Echinodictyum asperum, Jaspis splendens, Ptilocaulis spiculifer, Stylissa carteri and Suberites diversicolor. Other species (Agelas cavernosa, Agelas nemoechinata, Acanthostylotella cornuta, Paratetilla sp., Hymeniacidon sp. and Haliclona cymaeformis) deviated somewhat from the typical HMA/LMA dichotomy and formed a strongly supported cluster.

[COVID-19 pandemic: global epidemiological trends and China's subsequent preparedness and responses]

The outbreak of COVID-19 has spread quickly across 114 countries/territories/areas in six continents worldwide and has been announced as a pandemic by WHO. This study analyzed global COVID-19 epidemiological trends, examined impact of the pandemic on global health security, diplomacy, and social environment in China, and provided short- and long-term strategic policy recommendations for China's subsequent preparedness and responses.

Prednisolone dose during treatment of tuberculosis might be a risk factor for mortality in patients with systemic lupus erythematosus: a hospital-based cohort study

Patients with systemic lupus erythematosus (SLE) are at high risk of tuberculosis (TB) because of their immunocompromised status and the use of immunosuppressive drugs. In endemic regions, TB complicates the diagnosis and treatment of SLE, but the risk factors of mortality in these patients have not been investigated. In this study, we reviewed medical records during 2006–2016. Patients who fulfilled the 1997 American College of Rheumatology SLE criteria and presented with definite TB were enrolled. The primary outcome was mortality during TB treatment. There were 5388 SLE patients screened, and 30 patients were enrolled. Seven patients died during follow-up. Compared with the survival group, patients in the mortality group had significantly more central nervous system involvement of TB, higher Systemic Lupus Erythematosus Disease Activity Index-2000 scores and more cyclophosphamide use before TB, and higher prednisolone dose before and during TB treatment. Cox regression showed that prednisolone dose during TB treatment was an independent risk factor for mortality (per 10 mg/day increase, hazard ratio (HR) 1.61, p = .019). For SLE patients, prednisolone dose during TB treatment is an independent risk factor for mortality. Keeping prednisolone dose at less than 25 mg per day during TB treatment might be a reasonable strategy in these patients.

Analysis of EEG Lemple-Ziv complexity and correlative aspects before and after treatment of anti-syphilis therapy for neurosyphilis

Objective To investigate the diagnostic value of electroencephalogram (EEG) complexity in patients with neurosyphilis by comparing the changes of electroencephalogram Lempel-Ziv complexity (EEG-LZC) before and after anti-syphilis treatment. Methods The EEG complexity of neurosyphilis patients diagnosed in our hospital from July in 2015 to June in 2017 was analyzed and compared with other diagnostic results such as serology examination and cerebrospinal fluid examination. Results A total of 27 patients were diagnosed, including 19 males and 8 females, of which 6 were mesenchymal(cerebrospinal membrane and meningeal vascular), 16 were parenchymal(paralytic dementia, spinal cord tuberculosis and optic neuropathy), and 5 were asymptomatic. After intensive anti-syphilis therapy, the LZC increased significantly in all patients while the trend and degree of change were consistent with other diagnostic results. Conclusion The LZC can be used as one of the diagnostic indexes meanwhile the trend and degree of its change can be used as the reference index of curative effect to neurosyphilis.

[Clinical applications of intelligent pressure control flexible ureteroscope for the treatment of renal calculi ≤2 cm]

Objective: To evaluate the effectiveness and safety of intelligent pressure control flexible ureteroscope for management of renal stones ≤2 cm. Methods: The clinical data of 267 cases of renal calculi treated with flexible ureteroscope lithotripsy at Department of Urology, Ganzhou People's Hospital from June 2015 to December 2017 were analyzed retrospectively. There were 129 male and 138 female patients, with a mean age of 51.2 years (ranging from 19 to 76 years). Among them, 145 patients underwent intelligent pressure control flexible ureteroscope (intelligent control group) and 122 patients underwent flexible ureteroscope ordinary (ordinary group). The t test, χ² test or Fisher exact test were used for statistical analysis. The success rate of stone seeking, the stone free rates, the incidence of complications, the average operation time, the average hospital stay after operation were compared between the two groups. Results: The average mean operative time of the patients with intelligent control group was (26.17 ± 8.64) minutes, significantly shorter than (47.23±18.35) minutes of the ordinary group (t=1.968, P=0.000). The stone free rate of the patients with intelligent control group was 97.2%, it was higher than 86.0% of ordinary group (χ²=0.069, P=0.004). The complication rate of the patients with intelligent control group was 2.7%, which was significantly shorter than 18.0% of the ordinary group (χ²=17.586, P=0.000). However, there was no significant difference between the two groups in the success rate of stone seeking and postoperative hospital stay (P>0.05). Conclusion: Intelligent controlled pressure ureteral flexible ureteroscope has the advantages of short operation time, high stone free rate and less complications in the treatment of renal calculi ≤2 cm compared with flexible ureteroscope ordinary.

[Assessment of Height Prediction Model Based on SNPs Loci]

OBJECTIVES

To establish a height prediction model of Chinese Han male based on the reported 547 height-associated single nucleotide polymorphisms （SNPs） loci in Europeans, and assess its accuracy for height estimation.

METHODS

The DNA typing was analyzed in 59 Han male samples of Shandong province by Affymetrix SNP Array 6.0 chip and HiSeq 4000 sequencing platform. Prediction model was established using 547 height-associated SNPs loci as predictors and weight allele sums （WAS） as computing method. The accuracy of height prediction model was analysed using receiver operating characteristic （ROC） curve and area under curve （AUC）.

RESULTS

There was no height-associated SNPs locus was found by genome-wide association studies. In present study, height prediction model was established by WAS and obtained an AUC of 0.67 （95% CI: 0.53-0.90）.

CONCLUSIONS

It has reference value for predicting the height of Han male in Shandong province by WAS model based on 547 SNPs loci, while it is still necessary to further promote the accuracy of the prediction model by screening more height-associated SNPs loci with population heterogeneity.

Sponge Prokaryote Communities in Taiwanese Coral Reef and Shallow Hydrothermal Vent Ecosystems

Previously, it was believed that the prokaryote communities of typical 'low-microbial abundance' (LMA) or 'non-symbiont harboring' sponges were merely subsets of the prokaryote plankton community. Recent research has, however, shown that these sponges are dominated by particular clades of Proteobacteria or Cyanobacteria. Here, we expand on this research and assess the composition and putative functional profiles of prokaryotic communities from LMA sponges collected in two ecosystems (coral reef and hydrothermal vent) from vicinal islands of Taiwan with distinct physicochemical conditions. Six sponge species identified as Acanthella cavernosa (Bubarida), Echinodictyum asperum, Ptilocaulis spiculifer (Axinellida), Jaspis splendens (Tetractinellida), Stylissa carteri (Scopalinida) and Suberites sp. (Suberitida) were sampled in coral reefs in the Penghu archipelago. One sponge species provisionally identified as Hymeniacidon novo spec. (Suberitida) was sampled in hydrothermal vent habitat. Each sponge was dominated by a limited set of operational taxonomic units which were similar to sequences from organisms previously obtained from other LMA sponges. There was a distinct bacterial community between sponges collected in coral reef and in hydrothermal vents. The putative functional profile revealed that the prokaryote community from sponges collected in hydrothermal vents was significantly enriched for pathways related to DNA replication and repair.

FAMLF is a target of miR-181b in Burkitt lymphoma

Burkitt lymphoma (BL) is a highly malignant non-Hodgkin's lymphoma that is closely related to the abnormal expression of genes. Familial acute myelogenous leukemia related factor (FAMLF; GenBank accession No. EF413001.1) is a novel gene that was cloned by our research group, and miR-181b is located in the intron of the FAMLF gene. To verify the role of miR-181b and FAMLF in BL, RNAhybrid software was used to predict target site of miR-181b on FAMLF and real-time quantitative PCR (RQ-PCR) was used to detect expression of miR-181b and FAMLF in BL patients, Raji cells and unaffected individuals. miR-181b was then transfected into Raji and CA46 cell lines and FAMLF expression was examined by RQ-PCR and western blotting. Further, Raji cells viability and proliferation were detected by MTT and clone formation, and Raji cell cycle and apoptosis were detected by flow cytometry. The results showed that miR-181b can bind to bases 21–42 of the FAMLF 5′ untranslated region (UTR), FAMLF was highly expressed and miR-181b was lowly expressed in BL patients compared with unaffected individuals. FAMLF expression was significantly and inversely correlated to miR-181b expression, and miR-181b negatively regulated FAMLF at posttranscriptional and translational levels. A dual-luciferase reporter gene assay identified that the 5′ UTR of FAMLF mRNA contained putative binding sites for miR-181b. Down-regulation of FAMLF by miR-181b arrested cell cycle, inhibited cell viability and proliferation in a BL cell line model. Our findings explain a new mechanism of BL pathogenesis and may also have implications in the therapy of FAMLF-overexpressing BL.

Expression of T-lymphoma invasion and metastasis factor on the occurrence of oral squamous cell carcinoma

In recent years, many studies have found that tumor metastasis-related gene T-lymphoma invasion and metastasis-inducing factor 1 (TIAM1) had abnormal high expression in a variety of tumor cells; however, there are few studies regarding its expression in oral squamous cell carcinoma (OSCC). This study aimed to observe the expression of TIAM1 in OSCC and investigated its clinical significance. The expression of TIAM1 in tissues from 120 cases of OSCC and oral mucosa from 40 normal cases was detected by immunohistochemistry, and the relationship between the expression of TIAM1 and the clinicopathological parameters of OSCC was analyzed. The positive expression rate of TIAM1 in the OSCC tissues was significantly higher than that in the normal oral mucosa (92.5% vs 0%). With the decrease of histological differentiation of OSCC, the increase of tumor node metastasis (TNM) stage and the occurrence of lymph node metastasis, the TIAM1 staining positive rate was gradually increased, and the difference was statistically significant (P less than 0.05). However, the expression of TIAM1 in the OSCC tissues was in no correlation with the gender and age of the patients. The expression of TIAM1 is closely related to the occurrence, development and metastasis of OSCC, and it can be used as a new marker for reflecting its biological behaviors.

Important modifications by sugammadex, a modified γ-cyclodextrin, of ion currents in differentiated NSC-34 neuronal cells

BACKGROUND

Sugammadex (SGX) is a modified γ-cyclodextrin used for reversal of steroidal neuromuscular blocking agents during general anesthesia. Despite its application in clinical use, whether SGX treatment exerts any effects on membrane ion currents in neurons remains largely unclear. In this study, effects of SGX treatment on ion currents, particularly on delayed-rectifier K⁺ current [I _K(DR)], were extensively investigated in differentiated NSC-34 neuronal cells.

RESULTS

After cells were exposed to SGX (30 μM), there was a reduction in the amplitude of I _K(DR) followed by an apparent slowing in current activation in response to membrane depolarization. The challenge of cells with SGX produced a depolarized shift by 15 mV in the activation curve of I _K(DR) accompanied by increased gating charge of this current. However, the inactivation curve of I _K(DR) remained unchanged following SGX treatment, as compared with that in untreated cells. According to a minimal reaction scheme, the lengthening of activation time constant of I _K(DR) caused by cell treatment with different SGX concentrations was quantitatively estimated with a dissociation constant of 17.5 μM, a value that is clinically achievable. Accumulative slowing in I _K(DR) activation elicited by repetitive stimuli was enhanced in SGX-treated cells. SGX treatment did not alter the amplitude of voltage-gated Na⁺ currents. In SGX-treated cells, dexamethasone (30 μM), a synthetic glucocorticoid, produced little or no effect on L-type Ca²⁺ currents, although it effectively suppressed the amplitude of this current in untreated cells.

CONCLUSIONS

The treatment of SGX may influence the amplitude and gating of I _K(DR) and its actions could potentially contribute to functional activities of motor neurons if similar results were found in vivo.

Effect of bosentan is correlated with MMP-9/TIMP-1 ratio in bleomycin-induced pulmonary fibrosis

Pulmonary fibrosis (PF) is a life-threatening non-tumorous disease characterized by progressive fibrosis and worsening lung function. Various drugs, such as bleomycin, can contribute to lung injury and PF, with lung injury potentially occurring in 10% of bleomycin users. Bleomycin is the most commonly used drug in the establishment of an animal model of PF in rats. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) serve an important role in controlling tissue organization and fibrosis following injury. The present study examined the effect of bosentan on fibrotic lung tissue in rats administrated with bleomycin. In total, 48 Wistar rats were administrated with bleomycin, with or without bosentan, while the control rats received saline. The lung tissues were microscopically examined by staining with hematoxylin and eosin and Masson's trichome. ELISA was also used to detect the MMP-9 and TIMP-1 concentrations in the plasma. The results indicated that the bosentan-treated groups on the next day and the 15th day showed significant reversal of pathological findings. In addition, the concentrations of MMP-9 and TIMP-1 appeared to be altered following bosentan treatment, improving the bleomycin-induced PF. Masson's trichome staining showed high collagen deposition in the lung tissue sections, which may be a direct result of the activity of MMP-9 and TIMP-1. Furthermore, the deposition of collagen was significantly inhibited in bosentan-treated groups. In conclusion, these results demonstrated that bosentan inhibited lung fibrosis induced by bleomycin and it may be used as an inhibitor of PF.

Endothelial nitric oxide synthase deficiency influences normal cell cycle progression and apoptosis in trabecular meshwork cells

AIM

To clarify how the endothelial nitric oxide synthase (eNOS, NOS3) make effect on outflow facility through the trabecular meshwork (TM).

METHODS

Inhibition of NOS3 gene expression in human TM cells were conducted by three siRNAs. Then the mRNA and protein levels of NOS3 in siRNA-treated and negative control (NC) cells were determined, still were the collagen, type IV, alpha 1 (COL4A1) and fibronectin 1 by real-time PCR and Western blot analysis. In addition, NOS3 concentrations in culture supernatant fluids of TM cells were measured. Cell cycle and cell apoptosis analysis were performed using flow cytometry.

RESULTS

The mRNA level of NOS3 was decreased by three different siRNA interference, similar results were obtained not only of the relative levels of NOS3 protein, but also the expression levels of COL4A1 and fibronectin 1. The number of cells in S phase was decreased, while contrary result was obtained in G2 phase. The number of apoptotic cells in siRNA-treated groups were significant increased compared to the NC samples.

CONCLUSION

Abnormal NOS3 expression can make effects on the proteins levels of extracellular matrix component (e.g. fibronectin 1 and COL4A1). Reduced NOS3 restrains the TM cell cycle progression at the G2/M-phase transition and induced cell apoptosis.

A putative mechanism on remission of multiple sclerosis during pregnancy: estrogen-induced indoleamine 2,3-dioxygenase by dendritic cells

The basis for the reduced relapse rate of multiple sclerosis (MS) during pregnancy remains unexplained but, if defined, could create novel treatment options. Estrogen constitutes one candidate molecule, but the mechanism by which estrogen may affect MS during pregnancy is unclear. In this study, we used monocyte-derived dendritic cells (DCs) from MS patients to explore the estrogen (17-b-estradiol)-related pathway of immune modulation. Estrogen induced the expression of indoleamine 2,3-dioxygenase (IDO) on DCs, limiting T-cell proliferation and both Th1 and Th2 cytokine production. The suppression of T-cell proliferation mediated by estrogenexposed DCs was partly abolished by the IDO-inhibitor, 1-methyl-dl-tryptophan, indicating that estrogen-exposed DCs induced IDO-dependent T-cell suppression. Our data support the hypothesis that the change in the clinical course of MS observed in pregnancy may be related to the estrogen DC-IDO axis, which could represent a novel target for MS therapy.

Evidence for the Inhibition by Temozolomide, an Imidazotetrazine Family Alkylator, of Intermediate-Conductance Ca2+-Activated K+ Channels in Glioma Cells

Background: Temozolomide (TMZ), an oral alkylator of the imidazotetrazine family, is used to treat glioma. Whether this drug has any ionic effects in glioma cells remains largely unclear. Methods: With the aid of patch-clamp technology, we investigated the effects of TMZ on the ionic currents in U373 glioma cells. The mRNA expression of KCNN4 (KCa3.1) in U373 glioma cells and TMZ's effect on K+ currents in these KCNN4 siRNA-transfected U373 cells were investigated. Results: In whole-cell recordings, TMZ decreased the amplitude of voltage-dependent K+ currents (IK) in U373 cells. TMZ-induced IK inhibition was reversed by ionomycin or 1-ethyl-2-benzimidazolinone (1-EBIO). In cell-attached configuration, TMZ concentration-dependently reduced the activity of intermediate-conductance Ca2+-activated K+ (IKCa) channels with an IC50 value of 9.2 µM. Chlorzoxazone or 1-EBIO counteracted the TMZ-induced inhibition of IKCa channels. Although TMZ was unable to modify single-channel conductance, its inhibition of IKCa channels was weakly voltage-dependent and accompanied by a significant prolongation in the slow component of mean closed time. However, neitherlarge-conductance Ca2+-activated (BKCa) nor inwardly rectifying K+ (Kir) channels were affected by TMZ. In current-clamp mode, TMZ depolarized the cell membrane and 1-EBIO reversed TMZ-induced depolarization. TMZ had no effect on IK in KCNN4 siRNA-transfected U373 cells. Conclusion: In addition to the DNA damage it does, its inhibitory effect on IKCa channels accompanied by membrane depolarization could be an important mechanism underlying TMZ-induced antineoplastic actions.

The Inhibition by Oxaliplatin, a Platinum-Based Anti-Neoplastic Agent, of the Activity of Intermediate-Conductance Ca²⁺-Activated K⁺ Channels in Human Glioma Cells

Oxaliplatin (OXAL) is a third-generation organoplatinum which is effective against advanced cancer cells including glioma cells. How this agent and other related compounds interacts with ion channels in glioma cells is poorly understood. OXAL (100 µM) suppressed the amplitude of whole-cell K+ currents (I(K)); and, either DCEBIO or ionomycin significantly reversed OXAL-mediated inhibition of I(K) in human 13-06-MG glioma cells. In OXAL-treated cells, TRAM-34 did not suppress I(K) amplitude in these cells. The intermediate-conductance Ca(2+)-activated K+ (IK(Ca)) channels subject to activation by DCEBIO and to inhibition by TRAM-34 or clotrimazole were functionally expressed in these cells. Unlike cisplatin, OXAL decreased the probability of IK(Ca)-channel openings in a concentration-dependent manner with an IC50 value of 67 µM. No significant change in single-channel conductance of IK(Ca) channels in the presence of OXAL was demonstrated. Neither large-conductance Ca(2+)-activated K+ channels nor inwardly rectifying K+ currents in these cells were affected in the presence of OXAL. OXAL also suppressed the proliferation and migration of 13-06-MG cells in a concentration- and time-dependent manner. OXAL reduced IK(Ca)-channel activity in LoVo colorectal cancer cells. Taken together, the inhibition by OXAL of IK(Ca) channels would conceivably be an important mechanism through which it acts on the functional activities of glioma cells occurring in vivo.

Inhibitory actions by ibandronate sodium, a nitrogen-containing bisphosphonate, on calcium-activated potassium channels in Madin-Darby canine kidney cells

The nitrogen-containing bisphosphonates used for management of the patients with osteoporosis were reported to influence the function of renal tubular cells. However, how nitrogen-containing bisphosphates exert any effects on ion currents remains controversial. The effects of ibandronate (Iban), a nitrogen-containing bisphosphonate, on ionic channels, including two types of Ca²⁺-activated K⁺ (K_Ca) channels, namely, large-conductance K_Ca (BK_Ca) and intermediate-conductance K_Ca (IK_Ca) channels, were investigated in Madin–Darby canine kidney (MDCK) cells. In whole-cell current recordings, Iban suppressed the amplitude of voltage-gated K⁺ current elicited by long ramp pulse. Addition of Iban caused a reduction of BK_Ca channels accompanied by a right shift in the activation curve of BK_Ca channels, despite no change in single-channel conductance. Ca²⁺ sensitivity of these channels was modified in the presence of this compound; however, the magnitude of Iban-mediated decrease in BK_Ca-channel activity under membrane stretch with different negative pressure remained unchanged. Iban suppressed the probability of BK_Ca-channel openings linked primarily to a shortening in the slow component of mean open time in these channels. The dissociation constant needed for Iban-mediated suppression of mean open time in MDCK cells was 12.2 μM. Additionally, cell exposure to Iban suppressed the activity of IK_Ca channels, and DC-EBIO or 9-phenanthrol effectively reversed its suppression. Under current-clamp configuration, Iban depolarized the cells and DC-EBIO or PF573228 reversed its depolarizing effect. Taken together, the inhibitory action of Iban on K_Ca-channel activity may contribute to the underlying mechanism of pharmacological or toxicological actions of Iban and its structurally similar bisphosphonates on renal tubular cells occurring in vivo.

Stimulation of electroporation-induced inward currents in glioblastoma cell lines by the heat shock protein inhibitor AUY922

Membrane electroporation (MEP) increases the electrical conductivity of the plasma membrane by addition of an external electrical field. Combining MEP-induced current (IMEP ) with antineoplastic agents has been increasingly considered as a new therapeutic manoeuvre, especially in the treatment of malignant gliomas. Thus, the aim of the present study was to evaluate the effect of AUY922 (AUY), a potent inhibitor of heat-shock protein 90 (HSP90), on IMEP in glioblastoma cells. The IMEP in glioblastoma cells (U373) was generated by repetitive hyperpolarization from -80 to -200 mV. The amplitude of IMEP was increased by AUY in a concentration-dependent manner, with an EC50 of 0.32 μmol/L. In addition AUY shortened the latency to IMEP generation. Before depolarization to +50 mV, hyperpolarization to -200 mV for 50 msec produced Ca(2+) influx and subsequently increased the amplitude of the Ca(2+) -activated K(+) current (IK(Ca) ). The amplitude of IK(Ca) and Ca(2+) influx was further increased by AUY through its ability to activate IMEP . Other HSP90 inhibitors, namely 17-(allylamino)-17-demethoxygeldanamycin (17-AAG; 1 μmol/L) and 6-chloro-9-[(4-methoxy-3,5-dimethylpyridin-2-yl)methyl]-9H-purin-2-amine (BIIB021; 1 μmol/L), only slightly (albeit significantly) increased the amplitude of IMEP in glioblastoma cells. A 50 msec depolarizing step elevated Ca(2+) influx and subsequently increased the amplitude of IK(Ca) in the presence of these three inhibitors. These data indicate that the AUY-mediated stimulation of IMEP and IK(Ca) in glioblastoma cells is independent of HSP90 inhibition. Moreover, these results indicate that AUY-stimulated IMEP and the subsequent activation of IK(Ca) may create important signalling events in glioblastoma cells. Thus, AUY is a drug that could potentially be used to augment the effectiveness of electrochemotherapy.

Arecoline inhibits intermediate-conductance calcium-activated potassium channels in human glioblastoma cell lines

Arecoline (ARE) is an alkaloid-type natural product from areca nut. This compound has numerous pharmacological and toxicological effects. Whether this agent interacts with ion channels to perturb functional activity of cells remains unknown. The effects of ARE on ionic currents were studied in glioma cell lines (U373 and U87MG) using patch-clamp technique. Like TRAM-34(1-[(2-chlorophenyl)-diphenylmethyl]pyrazole), ARE suppressed the amplitude of whole-cell voltage-gated K(+) currents in U373 cells elicited by a ramp voltage clamp. In cell-attached configuration, ARE did not modify the single-channel conductance of intermediate-conductance Ca(2+)-activated K(+) (IKCa) channels; however, it did reduce channel activity. Its inhibition of IKCa channels was accompanied by a significant lengthening in the slow component of mean closed time of IKCa channels. Based on minimal kinetic scheme, the dissociation constant (KD) required for ARE-mediated prolongation of mean closed time was 11.2µM. ARE-induced inhibition of IKCa channels was voltage-dependent. Inability of ARE to perturb the activity of large-conductance Ca(2+)-activated K(+) (BKCa) channels was seen. Under current-clamp recordings, ARE depolarized the membrane of U373 cells and DCEBIO reversed ARE-induced depolarization. Similarly, ARE suppressed IKCa-channel activities in oral keratinocytes. This study provides the evidence that ARE block IKCa channels in a concentration, voltage and state-dependent manner. ARE-induced block of IKCa channels is unrelated to the binding of muscarinic receptors. The effects of ARE on these channels may partially be responsible for the underlying cellular mechanisms by which it influences the functional activities of glioma cells or oral keratinocytes, if similar findings occur in vivo.

Investigations on contribution of glial inwardly-rectifying K(+) current to membrane potential and ion flux: an experimental and theoretical study

The inwardly rectifying K(+) current [IK(IR)] allows large inward K(+) currents at potentials negative to K(+) equilibrium potential (EK) and it becomes small outward K(+) currents at those positive to EK. How changes of such currents enriched in glial cells can influence the functions of glial cell, neurons, or both is not clearly defined, although mutations of Kir4.1 channels have been demonstrated to cause serious neurological disorders. In this study, we identified the presence of IK(IR) in human glioma cells (U373 and U87 cells). The amplitude of IK(IR) in U373 cells was subject to inhibition by amitriptyline, arecoline, or BaCl2. The activity of inwardly rectifying K(+) channels was also clearly detected, and single-channel conductance of these channels was calculated to be around 23 pS. Moreover, based on a simulation model derived from neuron-glial interaction mediated by ion flux, we further found out that incorporation of glial IK(IR) conductance into the model can significantly contribute to regulation of extracellular K(+) concentrations and glial resting potential, particularly during high-frequency stimulation. Glial cells and neurons can mutually modulate their expression of ion channels through K(+) ions released into the extracellular space. It is thus anticipated that glial IK(IR) may be a potential target utilized to influence the activity of neuronal and glial cells as well as their interaction.

Effects of ibandronate sodium, a nitrogen-containing bisphosphonate, on intermediate-conductance calcium-activated potassium channels in osteoclast precursor cells (RAW 264.7)

Ibanonate sodium (Iban), a nitrogen-containing bisphosphonate, is recognized to reduce skeletal complications through an inhibition of osteoclast-mediated bone resorption. However, how this drug interacts with ion channels in osteoclasts and creates anti-osteoclastic activity remains largely unclear. In this study, we investigated the possible effects of Iban and other related compounds on ionic currents in the osteoclast precursor RAW 264.7 cells. Iban suppressed the amplitude of whole-cell K(+) currents (I K) in a concentration-dependent manner with an IC50 value of 28.9 μM. The I K amplitude was sensitive to block by TRAM-34 and Iban-mediated inhibition of I K was reversed by further addition of DCEBIO, an activator of intermediate-conductance Ca(2+)-activated K(+) (IKCa) channels. Intracellular dialysis with Iban diminished I K amplitude and further addition of ionomycin reversed its inhibition. In 17β-estradiol-treated cells, Iban-mediated inhibition of I K remained effective. In cell-attached current recordings, Iban applied to bath did not modify single-channel conductance of IKCa channels; however, it did reduce channel activity. Iban-induced inhibition of IKCa channels was voltage-dependent. As IKCa-channel activity was suppressed by KN-93, subsequent addition of Iban did not further decrease the channel open probability. Iban could not exert any effect on inwardly rectifying K(+) current in RAW 264.7 cells. Under current-clamp recordings, Iban depolarized the membrane of RAW 264.7 cells and DCEBIO reversed Iban-induced depolarization. Iban also suppressed lipopolysaccharide-stimulated migration of RAW 264.7 cells in a concentration-dependent manner. Therefore, the inhibition by Iban of IKCa channels would be an important mechanism underlying its actions on the functional activity of osteoclasts occurring in vivo.

Prolactin plays a stimulatory role in ovarian follicular development and egg laying in chicken hens

The aim of this study was to show a stimulatory role in ovarian follicle development by prolactin (PRL) in chicken hens. In experiment 1, anti-PRL antibodies were generated in hen plasma by intramuscular administrations of recombinant PRL antigen. Egg laying remained at levels lower (P < 0.05) in the PRL-immunized group than in the BSA-immunized group of hens, whereas development of incubation was depressed in the former but not the latter group. Throughout the experiment, plasma PRL concentrations were lower in the PRL-immunized hens than in non-incubating control hens; LH concentrations were similar between the PRL- and BSA-immunized hens until the end of the experiment when LH was lower in the BSA-immunized hens (P < 0.05). In experiment 2, anti-PRL receptor (PRLR) antibodies were raised in hens with the use of immunizations against recombinant PRLR extracellular domain. Immunization against PRLR initially increased the egg-laying rate when measured under the short photoperiod (12 h) but blocked the laying rate increase that occurred in the BSA-immunized control hens when the photoperiod was extended from 12 to 16 h. The development of incubation behavior was not affected by immunization against PRLR nor was plasma PRL or LH concentration. In experiment 3, when the egg-laying rate was depressed in PRL immunization hens, developmental speed of large white follicles was found to be slower than in the BSA-immunized control hens (P < 0.05). These results indicate that immunization against PRL slows down ovarian follicular development and reduces hen egg-laying performance, suggesting that PRL plays a stimulatory role in ovarian follicular development in chicken hens.

The influence of autonomic interventions on the sleep-wake-related changes in gastric myoelectrical activity in rats

BACKGROUND

Significant changes in autonomic activity occur at sleep-wake transitions and constitute an ideal setting for investigating the modulatory role of the autonomic nervous system on gastric myoelectrical activity (GMA).

METHODS

Using continuous power spectral analysis of electroencephalogram, electromyogram, and electrogastromyogram (EGMG) data from freely moving rats that had undergone chemical sympathetomy and/or truncal vagotomy, sleep-wake-related fluctuations in GMA were compared among the intervention groups.

KEY RESULTS

The pattern and extent of fluctuations in EGMG power across the sleep-wake states was blunted most significantly in rats undergoing both chemical sympathectomy and truncal vagotomy. The effect of these interventions also varied with respect to the transition between different sleep-wake states. The most prominent influences were observed between active waking and quiet sleep and between paradoxical sleep and quiet sleep.

CONCLUSIONS & INFERENCES

The sleep-wake-related fluctuations in EGMG power are a result of joint contributions from both sympathetic and vagal innervation. Vagotomy mainly resulted in a reduction in EGMG power, while the role of sympathetic innervation was unveiled by vagotomy and this was reflected most obviously in the extent of the fluctuations in EGMG power.

Multiple sclerosis: reduced proportion of circulating plasmacytoid dendritic cells expressing BDCA-2 and BDCA-4 and reduced production of IL-6 and IL-10 in response to herpes simplex virus type 1

OBJECTIVE

We hypothesized that autoaggressive immune responses observed in multiple sclerosis (MS) could be associated with an imbalance in proportion of immune cell subsets and in cytokine production in response to infection, including viruses.

METHODS

We collected blood mononuclear cells (MNC) from 23 patients with MS and 23 sex- and age-matched healthy controls (HC) from the island of Sardinia, Italy, where the prevalence of MS is extraordinarily high. Using flow cytometry, we studied MNC for expression of blood dendritic cell antigens (BDCA)-2 and BDCA-4 surface markers reflecting the proportion of plasmacytoid dendritic cells (pDC) that produce type I interferons (IFNs) after virus challenge and promote Th2/anti-inflammtory cytokine production. In parallel, pro-inflammatory (interleukin [IL]-2, IL-12, IFN-gamma), anti-inflammatory (IL-4, IL-10), and immuno-regulatory/pleiotropic cytokines (type I IFNs including IFN-alpha and beta, IL-6) were measured before and after an in vitro exposure to herpes simplex virus type 1 (HSV-1).

RESULTS

The subset of lineage negative (lin(-)), BDCA-2(+) cells was lower in patients with MS compared with HC (0.08 + or - 0.02% vs 0.24 + or - 0.02%; P < 0.001). A similar pattern was observed for lin(-)BDCA-4(+) cells (0.08 + or - 0.02% vs 0.17% + or - 0.03; P < 0.01). Spontaneous productions of IL-6 (45 + or - 10 pg/mL vs 140 + or - 26 pg/mL; P < 0.01) and IL-10 (17 + or - 0.4 pg/mL vs 21 + or - 1 pg/mL; P < 0.05) by MNC were lower in patients with MS compared with HC. Spontaneous production of IL-6 (6.5 + or - 0.15 pg/mL vs 21 + or - 5 pg/mL; P < 0.01 and IL-10 (11 + or - 1 pg/mL vs 14 + or - 3 pg/mL; P < 0.05) by pDC was also lower in patients with MS compared with HC. Exposure of MNC to HSV-1 showed, in both patients with MS and HC, increased production of IFN-alpha, IL-6, and IL-10 but decreased production of IL-4. In response to HSV-1 exposure, productions of IL-6 (165 +or - 28 pg/mL vs 325 + or - 35 pg/mL; P < 0.01) and IL-10 (27 +or - 3 vs 33 + or - 3 P < 0.05) by MNC as well as by pDC (IL-6: 28 + or - 7 vs 39 + or - 12 P < 0.05; IL-10: 14 + or - 1 vs 16 + or - 3 P < 0.05) were lower in patients with MS compared with HC.

CONCLUSION

The results implicate a new evidence for altered immune cells and reduced immune responses in response to viral challenge in MS.

Endocrine regulations of reproductive seasonality, follicular development and incubation in Magang geese

This study investigated the regulatory mechanisms of seasonal breeding, developments of ovarian follicles and incubation in Magang geese, a short day breeding bird. Throughout the year, plasma PRL concentrations increased in non-breeding season in spring and summer (from April to early August), and remained low in the rest of the year, while LH concentrations peaked in August and September and remained low in non-breeding season (March to June). Lengthening photoperiod increased PRL and decreased LH secretions, which inhibited follicular development, terminated lay and induced moulting, while shortening photoperiod decreased PRL and increased LH secretion and reinitiated lay. Long photoperiod stimulated PRL secretion occurred with increased gene expressions of PRL in the pituitary gland and VIP in the hypothalamus, but inhibition of LH secretion was without decreases in gene expressions of LH beta subunit and GnRH. Under breeding conditions, terminating incubation decreased PRL but increased LH concentrations and resumed lay in 24 days following recruitment of about 10 large white follicles into hierarchical development. Plasma concentrations of progesterone and inhibin peaked at peak lay, whereas LH concentrations exhibited a bi-phasic pattern with troughs at peak lay and incubation when PRL concentrations were high. Ninety percent geese exhibited incubation behaviour after laying one clutch of approximately eight eggs in approximately 30 days. In conclusion the seasonal reproductive activities in Magang geese is directly inhibited by long photoperiod and directly stimulated by short photoperiod via PRL and LH secretions, whose interplays also cause occurrences of four to five lay and incubation cycles in the breeding season.

Scheduling multiprocessor job with resource and timing constraints using neural networks

The Hopfield neural network is extensively applied to obtaining an optimal/feasible solution in many different applications such as the traveling salesman problem (TSP), a typical discrete combinatorial problem. Although providing rapid convergence to the solution, TSP frequently converges to a local minimum. Stochastic simulated annealing is a highly effective means of obtaining an optimal solution capable of preventing the local minimum. This important feature is embedded into a Hopfield neural network to derive a new technique, i.e., mean field annealing. This work applies the Hopfield neural network and the normalized mean field annealing technique, respectively, to resolve a multiprocessor problem (known to be a NP-hard problem) with no process migration, constrained times (execution time and deadline) and limited resources. Simulation results demonstrate that the derived energy function works effectively for this class of problems.

Molecular cloning and characterisation of the Magang goose prolactin gene

In studying the roles of prolactin in regulation of seasonal reproduction, incubation, broodiness and laying performance in goose, the goose PRL gene was cloned in Magang goose. The goose PRL cDNA shared 98.4%, 92.2%, 92%, and 91.9% sequence homology to duck, turkey, chicken and quail PRLs, respectively. The goose PRL gene consisted of 5 exons and 4 introns, just as in other species. The 5' proximal regulatory region shared high homology with those in other avian species as well, and, apart from other non-specific transcription factor binding sites, contained 2 regulatory element binding sites, a Pit-1 (-130/-122) and a VIP response element (-64/-53). The deduced 199-residue mature goose PRL shared 98.5%, 94%, 93%, and 92% homology to duck, quail, chicken, and turkey PRLs, respectively. When compared with other vertebrates, all residues were found to be highly conserved at the key positions in the 4 conserved domains (PD1-PD4), including the 6 cysteine residues at positions 4, 11, 58, 175, 191, and 199. The only exception was a substitution of Arginine by Histidine at position 176 in the mature PRL peptide. These findings render goose PRL as having a similar hydropathy profile and similar secondary and tertiary structures with other PRLs. Goose PRL also possesses an N-linked glycosylation site (Asn-X-Ser), at position 6, and an alternative glycosylation site (Asn-Gly-Cys), at position 56. Five PRL isoforms were detected in goose, as well as in chicken pituitary glands, by immunoblotting analysis. Results of this study not only provided a starting point for further study of PRL function, synthesis, and secretion in goose species, but also for breeding new goose lines efficiently using the genomic information.

Seasonal and photoperiodic regulation of secretion of hormones associated with reproduction in Magang goose ganders

This study examined the reproductive endocrine profile under natural and artificial photoperiods in Magang goose ganders. Group 1 ganders (n=8) served as non-treated controls and were exposed to natural photoperiod throughout the experiment from 13th January to 17th December 2004. Group 2 ganders (n=8) were exposed to 18 h long daily photoperiod for 60 days from 13 January till 15 March 2004 and again to 16 h photoperiod for 75 days till 10th October 2004, and the 11h short photoperiod in the remainder periods of the experiment. In control ganders, plasma LH concentrations were high in normal breeding seasons (August-March) and decreased to low levels in non-breeding season from April to July. Testosterone concentrations changed similarly to that of LH throughout the seasons. Seasonal pattern of PRL concentrations was opposite to those of LH and testosterone, with low values in breeding season and high values in non-breeding season. In artificial photoperiod treated ganders, increasing photoperiod increased PRL and decreased LH and testosterone concentrations, while decreasing photoperiod reversed these changes. There were no seasonal or photoperiod caused changes in plasma T3 concentrations in both control ganders and artificial photoperiod treated ganders. These results demonstrated that in Magang goose ganders that long photoperiod stimulates PRL secretion and decreases LH secretion, which terminates reproductive season in spring and early summer, and short photoperiod stimulates LH secretion and inhibits PRL secretion rendering ganders enter into reproductive season.

Multiple sclerosis: interferon-beta induces CD123(+)BDCA2- dendritic cells that produce IL-6 and IL-10 and have no enhanced type I interferon production

Interferon-beta (IFN-beta), an approved drug for multiple sclerosis (MS), acts on dendritic cells (DC) by suppressing IL-12p40 and increasing IL-10. This results in Th2-biased immune responses. The nature of IFN-beta-modulated DC remains elusive. Previously, we observed that IFN-beta dose dependently induces expression of CD123, i.e., a classical marker for plasmacytoid DC, on human blood monocyte-derived myeloid DC. Such IFN-beta-modulated DCs produce predominantly IL-10 but are IL-12 deficient, with potent Th2 promotion. In the present study, we further characterize IFN-beta-modulated DC by using recently identified blood DC antigens (BDCA), and investigate their ability to produce type I IFN in response to virus stimulation. We show that IFN-beta induces development of CD123+ DC from human blood monocytes, which coexpress BDCA4+ but are negative for BDCA2-, a specific marker for plasmacytoid DC. Such IFN-beta-modulated DC can produce IL-6 and IL-10 but not IL-12p40, and have no enhanced IFN-alpha and IFN-beta production. The findings indicate that IFN-beta-modulated DCs represent a myeloid DC subset with diminished CD11c, BDCA-1 and CD1a expression. They may promote Th2 and B cell differentiation through IL-6 and IL-10 production, and suppression of IL-12p40, but they have no enhanced antiviral capacity.

[Investigation on genotype constitution of different Plasmodium vivax isolates and its geographical distribution in China]

OBJECTIVE

To investigate the population constitution and geographical distribution of Plasmodium vivax in China using molecular technique.

METHODS

Blood-spot filter paper samples with related epidemiological data were collected from vivax malaria patients living in malarious area of 10 provinces (autonomous region) in China. Semi-nested- or nested-allelic-specific PCR genotyping method was used to identify CSP genotypes, families and types of Plasmodium vivax of each isolate from these patients.

RESULTS

Of 384 field isolates of Plasmodium vivax, 258 temperate zone family strains were identified, including 14 allelic variant genotypes spreading among 10 sampling provinces; allelic variants sized less than 731 bp were only seen in 5 provinces in southern China; 79 tropical zone family strains including 5 genotypes were also distributed in 5 provinces of southern China south to 25 degrees N. lat; and 14 PV Type-2 strains including 2 genotypes were found in some areas of Hainan and Yunnan Provinces. In addition, 33 isolates from genotype-mixed infections were revealed.

CONCLUSION

At present, area north to 25 degrees N. lat. of the country is the sole area prevalent for Plasmodium vivax family strains of temperate zone; there is overlapping distribution of P. v. of temperate zone family and tropical zone family of this parasite in the southern China south to 25 degrees N. lat; where the most complex isolate constitution is in Yunnan and Hainan Provinces, and PV Type-2 strains have been found in some areas of the two provinces. Besides, there were 2 groups of genotype with distinct geographic distribution feature within the temperate zone family.

[Studies on identification of circumsporozoite protein genotyping of Plasmodium vivax]

OBJECTIVE

To develop a new method of genotyping circumsporozoite protein (CSP) gene for identification of field isolates of Plasmodium vivax.

METHODS

Improved Chelex-100 ion-exchange method was used to extract DNA from blood filter paper samples, nested PCR and allele-specific PCR techniques, agarose gel electrophoresis analysis and dot/southern blotting-probe hybridization were employed for amplification, resolution and identification of the diagnostic fragments.

RESULTS

Using the nest-allele-specific PCR assay reported here, small amounts of DNA extracted from a piece of blood filter paper sample were amplified which produced three different size ranges of diagnostic bands: 650-770 bp PV-species-specific band, 170-230 bp diagnostic band for temperate zone family and 588 bp band for PV type-2. The sizes and patterns of the bands produced by the reference strains were consistent with those of designed target sequences. Of 59 examined isolates from 6 provinces of China, 42 temperate zone family strains, 15 tropical zone family strains and two PV type-2 strains were identified.

CONCLUSION

1, Three genotype strains of P. vivax mentioned above could be identified by this method with only two rounds of PCR and without probe hybridization. 2, The preliminary results showed that PV type-1 including temperate zone family strains and tropical zone family strains as well as PV type-2 strains are present in China. In addition, another CSP genotype with both sequence characteristics of temperate zone and tropical zone family might also be present in China.

Assessment of myocardial viability in a porcine model of chronic coronary artery stenosis with dual dose dobutamine magnetic resonance imaging

In a non-surgical porcine coronary stenosis model resulting in chronic left ventricle dysfunction, we aimed in this study to evaluate the potential of magnetic resonance imaging (MRI) to distinguish dysfunctional but viable from necrotic myocardium by using multiple levels of dobutamine inotropic stimulation during a cine MRI protocol (F.P. van Rugge et al. Circulation 1994; 90: 127-138). We compared our results with histopathology. We were able to demonstrate a biphasic effect at increasing doses of dobutamine in a subgroup of animals with a high-grade coronary stenosis, while in another subgroup the coronary stenosis produced a chronic myocardial infarction, in which no functional recovery could be obtained. In this experimental protocol, dual dose dobutamine MRI proved to be an accurate and reproducible technique to perform viability studies in chronic obstructive coronary artery disease. It permits distinguishing chronic ischemic, but viable myocardium from infarcted tissue. The detection of chronically underperfused but potentially salvageable myocardium is of significant clinical importance since it may aid in determining which patients are eligible for revascularization.

Synthesis and biological evaluation of thioglycosylated porphyrins for an application in photodynamic therapy

The aim of this work is the synthesis of a new family of glycosylated porphyrins in which the sugar moieties are linked to the tetrapyrrole ring by a thioglycosidic bond. Two series have been designed. The first one corresponds to meso-aryl porphyrin derivatives. The second one has been obtained from protoporphyrin IX derivatization. Aryl-porphyrins were prepared from tristolyl o- and p-hydroxyporphyrins followed by bromoallylation and thioglycosylation with peracetylated S-glucose, mannose and galactose and deprotection. The other series has been synthesized from protoporphyrin IX dimethylester with a regioselective glycosylation of terminal alkenyl carbon. The UV-visible, NMR and MALDI mass spectra are presented. Photocytotoxicities of the synthesized compounds against K562 chronic leukaemia cell line has been evaluated.

Glatiramer acetate and IFN-beta act on dendritic cells in multiple sclerosis

Glatiramer acetate (GA; Copolymer 1; Copaxone) and interferon-beta (IFN-beta) modulate the course of multiple sclerosis (MS), but probably by different mechanisms. GA, a mixture of synthetic peptides, is believed to act as an altered peptide ligand with inhibitory effects on autoreactive T cells and promoting Th2 cells. It is unknown whether GA affects dendritic cells (DCs), which, besides strong antigen presenting capacity, orchestrate Th1 and Th2 responses. IFN-beta inhibits IL-12 production by DCs over unknown mechanisms. This study was designed to investigate in vitro effects of GA and IFN-beta on the development and function of DCs from MS patients and healthy controls, and to explore their possible synergistic effects on DCs. DCs were generated from adherent blood mononuclear cells (MNCs). GA or IFN-beta or both, when added at initiation of DC cultures, rapidly promoted the development of adherent MNCs into floating, activated DCs as reflected by up-regulation of HLA-DR and CD86 expression. IFN-beta, but not GA, induced IL-3R expression on DCs. Compared to DCs from healthy controls, MS patients' DCs expressed higher levels of the myeloid DC marker CD1a and produced lower amounts of IL-10. GA reduced IL-12 production by DCs. IFN-beta also reduced IL-12, but increased IL-10 production by DCs from both MS patients and healthy controls. GA and IFN-beta synergistically suppressed CD1a and enhanced CD86 expression on MS DCs. These findings document novel mechanisms of action of GA and IFN-beta at the DC level in MS.

Velocity shear stabilization of centrifugally confined plasma

A magnetized, centrifugally confined plasma is subjected to a 3D MHD stability test. Ordinarily, the system is expected to be grossly unstable to "flute" interchanges of field lines. Numerical simulation shows though that the system is stable on account of velocity shear. This allows consideration of a magnetically confined plasma for thermonuclear fusion that has a particularly simple coil configuration.

Multiple sclerosis: deficient in vitro responses of blood mononuclear cells to IFN-beta

IFN-beta may modify the clinical course of multiple sclerosis (MS) but is not curative, and there are also patients whose disease does not respond to IFN-beta as currently administered. Tests are warranted with a capacity to early discriminate responders from non-responders, thereby altering treatment option for the individual patient. In vitro effects of IFN-beta on expression of activation-associated cell surface markers and cytokine production need to be explored in this context. Here we report on the influence in vitro of IFN-beta on blood mononuclear cells (MNC) prepared from MS patients and healthy controls. MNC were subjected to short-term culture in the presence of IFN-beta at concentrations of 100 U/ml and 1000 U/ml. Expression of cell surface molecules CD40, CD69, CD80, CD86, CD95 and HLA-DR was measured by flow cytometry. IL-10 and IL-12 p40 production in culture supernatants was measured by ELISA. MNC exposed to IFN-beta in vitro enhanced expression of the co-stimulatory CD80, CD86, the early activation antigen CD69 and the cell death receptor CD95. Expression of CD40 and HLA-DR was not influenced. IFN-beta increased IL-10 but suppressed IL-12 p40 production. In vitro effects of IFN-beta on MNC were similar in MS patients and in healthy subjects, except that IFN-beta-induced augmentation of CD86 and CD69 expression was less pronounced in MS, in particular in untreated MS patients. Individual MS patients clearly responded differently to IFN-beta in vitro in comparison with the majority of patients in this cross-sectional study. In conclusion, anti-inflammatory effects of IFN-beta on blood MNC include augmentation of IL-10 production and suppression of IL-12 p40 production, which are accompanied by enhancement of CD69, CD80, CD86 and CD95 expression. The less pronounced IFN-beta-induced effects on CD86 and CD69 expression in MS vs controls might reflect a defect in immunoregulation in MS. Larger groups should be evaluated, and follow-up studies performed in MS patients before/during IFN-beta treatment in relation to clinical outcome measures to evaluate the usefulness of these markers for possible differentiation between responders and non-responders to IFN-beta treatment.

Enzyme-linked immunospot assays provide a sensitive tool for detection of cytokine secretion by monocytes

Blood monocytes as well as tissue-differentiated macrophages play a pivotal role in controlling immune reactions. Monocytes regulate the extent, nature, and duration of immune responses by secretion of cytokines. Interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-alpha), IL-10, and IL-12 are of particular interest, since IL-12 shifts the immune response towards a Th1 type, facilitating the production of, e.g., TNF-alpha and IL-6, while IL-10 counteracts Th1 responses and promotes the production of Th2-related cytokines such as IL-4. A tight regulation of these four cytokines keeps the balance and decides whether Th1 or Th2 will predominate in immune reactions. Enzyme-linked immunospot (ELISPOT) assays are among the most-sensitive and -specific methods available for cytokine research. They permit ex vivo identification of individual cells actively secreting cytokines. In the present study we prepared monocytes from healthy subjects' blood and adapted ELISPOT assays to define optimal conditions to detect and enumerate monocytes secreting IL-6, TNF-alpha, IL-10, and IL-12. The optimal time for monocyte incubation was 24 h, and optimal monocyte numbers (in cells per well) were 2,000 for IL-6, 1,000 for TNF-alpha, 50,000 for IL-10, and 100,000 for enumeration of IL-12 secreting monocytes. Among healthy subjects, 10% +/- 5% of the monocytes secreted IL-6, 12% +/- 12% secreted TNF-alpha, 0.1% +/- 0.1% secreted IL-10, and 0.2% +/- 0.3% secreted IL-12 (values are means +/- standard deviations). In conclusion, ELISPOT assays constitute a valuable tool to enumerate monocytes secreting IL-6, TNF-alpha, IL-10, and IL-12 and probably to enumerate monocytes secreting other cytokines and proteins.