The transmission network and spatial-temporal distributions of COVID-19: A case study in Lanzhou, China.

Public emergencies exert substantial adverse effects on the socioeconomic development of cities. Investigating the transmission characteristics of COVID-19 can lead to evidence-based strategies for future pandemic intervention and prevention. Drawing upon primary COVID-19 data collected at both the street level and from individuals with confirmed cases in Lanzhou, China, our study examined the spatial-temporal distribution of the pandemic at a detailed level. First, we constructed transmission networks based on social relationships and spatial behavior to elucidate the actual natural transmission chain of COVID-19. We then analyze key information regarding pandemic spread, such as superspreaders, superspreading places, and peak hours. Furthermore, we constructed a space-time path model to deduce the spatial transmission trajectory of the pandemic while validating it with real activity trajectory data from confirmed cases. Finally, we investigate the impacts of pandemic prevention and control policies. The progression of the pandemic exhibits distinct stages and spatial clustering characteristics. People with complex social relationships and daily life trajectories and places with high pedestrian flow and commercial activity venues are prone to becoming superspreaders and superspreading places. The transmission path of the pandemic showed a pattern of short-distance and adjacent transmission, with most areas not affected. Early-stage control measures effectively disrupt transmission hotspots and impede the spatiotemporal trajectory of pandemic propagation, thereby enhancing the efficacy of prevention and control efforts. These findings elucidate the characteristics and transmission processes underlying pandemics, facilitating targeted and adaptable policy formulation to shape sustainable and resilient cities.

[Effect of dexamethasone on expressions of TWEAK and Fn14 in the lung of asthmatic mice].

AIM: To investigate the effect of dexamethasone (Dex) on the expressions of TNF-like weak inducer of apoptosis (TWEAK) and fibroblast growth factor-inducible immediate-early response protein 14 (Fn14) in the lung of asthmatic mice. METHODS: Ovalbumin (OVA) was used to induce asthma in BALB/c mice. Thirty-six female mice were randomly divided into control group (n=12), asthmatic group (n=12) and Dex treated group (n=12). The airway inflammation was evaluated by HE staining. The expressions of TWEAK and Fn14 at mRNA and protein levels were detected by RT-PCR and immunohistochemistry, respectively. RESULTS: Both mRNA and protein levels of TWEAK and Fn14 in the asthmatic model group were significantly higher than those of control group (P<0.01), and both mRNA and protein levels of TWEAK and Fn14 in the Dex treated group were significantly lower than those of asthmatic group (P<0.01). CONCLUSION: Dex can reduce the airway inflammation through inhibiting the expressions of TWEAK and Fn14.

Hypersensitivity of lung vagal C fibers induced by acute intermittent hypoxia in rats: role of reactive oxygen species and TRPA1.

Obstructive sleep apnea, manifested by intermittent hypoxia and excess production of reactive oxygen species (ROS) in airways, is associated with hyperreactive airway diseases, but the mechanism remains unclear. Sensitization of lung vagal C fibers (LVCFs) contributes to the airway hypersensitivity. We investigated the mechanisms underlying the sensitization of LVCFs with acute intermittent hypoxia (AIH), by 10 episodes of exposure to 30 s of hypoxic air (0%, 5%, or 10% O(2)) followed by 30 s of room air in anesthetized, open-chest, and artificially ventilated rats. Reflex apneic response to intravenous capsaicin (an LVCF stimulant), as measured by phrenic nerve activity, was concentration dependently augmented by AIH. Similarly, reflex apneic response to intravenous α,ß-methylene-ATP (another LVCF stimulant) was augmented by AIH (0% O(2)). The reflex apnea evoked by these two stimulants was abolished by bilateral vagotomy, which suggests the involvement of lung vagal afferents. The AIH-augmented apneic response to these two stimulants was prevented by pretreatment with dimethylthiourea (a hydroxyl radical scavenger), N-acetyl-l-cysteine (an antioxidant) and HC-030031 [a transient receptor potential ankyrin 1 (TRPA1) receptor antagonist]. Consistently, electrophysiological study revealed the afferent responses of LVCFs to capsaicin or α,ß-methylene-ATP were augmented by AIH, and this sensitization of LVCFs was prevented by dimethylthiourea, N-acetyl-l-cysteine, and HC-030031. In contrast, AIH did not alter the afferent response of LVCFs to mechanical stimulation by lung hyperinflation. We concluded that AIH sensitizes LVCFs in rats, thus resulting in exaggerated airway reflexogenic responses to chemical stimulants, possibly by ROS action and activation of TRPA1 receptors.

PSMA7 inhibits the tumorigenicity of A549 human lung adenocarcinoma cells.

The gene for proteasome subunit alpha type-7 (PSMA7) is located in chromosomal 20q13.33, a region frequently amplified in tumor. In this study, we employed A549 human lung adenocarcinoma cells and showed that PSMA7 inhibits the proliferation, tumorigenicity and invasion of A549 cells in vitro. Moreover, both gain and loss of function studies demonstrated that PSMA7 modulates the tumorigenicity of A549 cells in a xenograft nude mice model. In conclusion, these results identify inhibitory effects associated with PSMA7 that affect the tumorigenicity of A549 cells, suggesting PSMA7 as a potential tumor biomarker.

[Change of IL-22R1 expression in human airway smooth muscle cells in response to different stimulating agents].

OBJECTIVE: To explore the effects of serum of asthmatic patients, dexamethasone, interleukin-4 (IL-4), interferon-gamma (IFN-γ) and transforming growth factor-ß (TGF-ß) on the expression of interleukin-22 receptor 1 (IL-22R1) mRNA and protein in HASMCs in vitro. METHODS: IL-22R1 mRNA and protein expressions in HASMCs treated with different stimulating agents were measured by real-time PCR and Western blotting, respectively. RESULTS: IL-22R1 mRNA and protein expressions in HASMCs were significantly increased after stimulation by serum from asthmatic patients, but decreased after co-stimulation with dexamethasone. IL-22R1 mRNA and protein expressions in the cells both increased after stimulation by IL-4, IFN-γ and TGF-ß. CONCLUSION: IL-22R1 in HASMCs might be involved in the pathogenesis of asthma, and the therapeutic effect of dexamethasone on asthma is mediated, at least partially, by IL-22R1. The effects of IFN-γ, IL-4, and TGF-ß on asthma may also be attributed to their actions on HASMCs.

[Construction of recombinant eukaryotic expression vector pDsRed1-C3/XAPC7 and cellular localization of XAPC7 protein in different cell lines].

AIM: To construct the recombinant eukaryotic expression vector pDsRed1-C3/XAPC7 and to investigate the cellular localization of XAPC7 protein in 786-O and 293T and Chang liver cell lines. METHODS: The cDNA of XAPC7 was amplified from HBE135-E6E7 cell line by RT-PCR method. The aim gene fragment XAPC7 from pMD18-T/XAPC7 was subcloned into eukaryotic expression vector pDsRed1-C3. The recombinant plasmid pDsRed1-C3/XAPC7 was identificated by BamH I/Xho I double digestion and sequence analysis, and then transfected into786-O and 293T and Chang liver cell lines by lipofectamine 2000. The expression and cellular localization of XAPC7 protein were detected by fluorescence microscope. RESULTS: The construction of the recombinant plasmid pDsRed1-C3/XAPC7 was proved successfully by restriction enzyme digestion analysis and DNA sequencing. Red fluorescent protein pDsRed1-C3/XAPC7 was distributed granularly in transfected cell lines. Our researches showed that XAPC7 protein was mainly expressed in the cytoplasm of 786-O cell line, rare in its nucleus, evenly distributed in the cytoplasm and nucleus of 293T cell line, and mainly located in the cytoplasm of Chang liver cell line, few in its nucleus. CONCLUSION: The eukaryotic expression plasmid pDsRed1-C3/XAPC7 has been successfully constructed and expressed in the 786-O and 293T and Chang liver cell lines, but there was obvious difference in different cell lines. Our researches will help further studies on the function of human gene XAPC7.

[Association of the C3 gene polymorphisms with susceptibility to adult asthma].

OBJECTIVE: To investigate the association between single nucleotide polymorphisms (SNPs) of the complement component 3 gene (C3) and adult asthma of Hans in southern China. METHODS: A case-control study was performed. Four hundred and eighty-four adult asthma patients diagnosed in Nanfang Hospital and Affiliated Hospital of Guangdong Medical College, and 553 healthy subjects were collected from 2006 to 2010 for the study. MassARRAY-IPLEX and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) techniques was used to determine the genotypes of the rs10402876 and rs366510 loci of C3 gene. RESULTS: Genotypes GG, GT and TT in the rs366510 locus, and genotypes GG, GT and TT in the rs10402876 locus were detected. A total of 98.94 percent of samples were genotyped. There were no significant differences in genotype frequencies (chi-square =0.346,P=0.841) and allele frequencies (chi-square =0.101,P=0.751) of rs10402876 between the two groups. However, genotype and allele frequencies of the rs366510 locus were significantly different (chi-square =9.759, P=0.008, Bonferroni correction, P=0.016; chi-square =5.294,P=0.021, Bonferroni correction, P=0.042, respectively). Compared with genotypes GG+GT, genotype TT of rs366510 significantly increased the risk of asthma, with the odds ratio of 1.471 (95% confidence interval 1.125-1.923). CONCLUSION: These results suggest that C3 gene could be associated with adult asthma of Han population in southern China.

[Application of flexirigid thoracoscopy in the diagnosis of pleural disease with unknown etiology].

OBJECTIVE: To investigate the diagnostic accuracy of flexirigid thoracoscopy for pleural diseases and the patients' compliance. METHODS: Forty-seven patients with pleural effusion and thickening of unknown etiology underwent examinations with flexirigid thoracoscopy with subsequent pathological examination, and the diagnostic accuracy and the patients' compliance were observed. RESULTS: Thoracoscopy identified lesions in the pleural and/or diaphragm in 42 patients and no lesions in 5 patients. Malignancy was confirmed in 21 (44.7%), tuberculosis in 17 (36.2%), idiopathic hypereosinophilic syndrome in 1 (2.1%), nocardiasis in 1 (2.1%), constrictive pericarditis in 1 (2.1%), chronic empyema in 2 (4.3%), splenic artery embolization in 1 (2.1%), and negative result in 3 (6.4%) of the cases. The diagnostic accuracy rate of flexirigid thoracoscopy reached 93.6%, and no serious complications in relation to the examination was found. CONCLUSION: Flexirigid thoracoscopy is efficient and relatively safe for diagnosis of pleural diseases with or without hydrothorax.

[Association of single nucleotide polymorphisms of MD-1 gene with asthma in adults of Han Nationality in Southern China].

OBJECTIVE: To investigate the correlation between MD-1 gene single nucleotide polymorphism (SNP) and bronchial asthma in adults of the Han nationality in Southern China as well as their lung functions. METHODS: From 2006 to 2010, 332 adult asthmatic patients of the Han nationality diagnosed in Nanfang Hospital, Southern Medical University, and 276 healthy volunteers were recruited for the study. The SNPs of MD-1 gene loci rs2233128 and rs7740529 were genotyped by using MassARRAY-IPLEX technology and matrix-assisted laser desorption ionization time of flight mass spectrometry platform (MALDI-TOF-MS). In addition, the lung function of 105 cases initially diagnosed with asthma was measured. RESULTS: There was no significant difference in sex (χ(2) = 0.50, P = 0.824) and age (t = 0.930, P = 0.357) between the asthma and the healthy groups. Genotypes AG and GG were detected in MD-1 gene at rs2233128 locus and genotypes CC, CT and TT at rs7740529 locus in this Han population at Southern China. Genotyping success rate was 94.74%. The rs2233128 genotype distribution (χ(2) = 0.030, P = 0.863) and allele (χ(2) = 0.029, P = 0.865) showed no significant difference between the asthma and the control groups. However, the rs7740529 genotype distribution (χ(2) = 8.681, P = 0.013) and allele (χ(2) = 8.005, P = 0.005) were significantly different in the asthma group as compared to the control group. Compared with the TT genotype, the rs7740529 of the CC and CC + CT genotypes could dramatically increase the risk of asthma, the odds ratio (95% confidence interval) being 2.451 (1.299 - 4.9626) and 2.172 (1.173 - 4.020), respectively. In the 105 patients initially diagnosed with asthma, FVC% and FEV(1)% were significantly different among the 3 different genotypes (CC, CT and TT) of the rs7740529 locus (F = 18.405, P = 0.000 and F = 25.700, P = 0.000). The percentages of predicted value of FVC and FEV(1) were decreased [(65 ± 12)%, (64 ± 11)%] in the CC genotype as compared to the TT genotypes [(86 ± 9)%, (88 ± 8)%], P < 0.05. There was no significant difference of genotype distribution of rs7740529 in different grades of severity of newly diagnosed asthma (χ(2) = 5.017, P = 0.081). CONCLUSIONS: MD-1 may be a susceptible gene for adult asthma in a Southern Han population in China. Genotype distribution of rs7740529 locus in newly diagnosed patients with asthma may be related to their lung function changes.

[Alteration of PTEN gene expression affects the migration of human airway smooth muscle cells in vitro].

OBJECTIVE: To investigate the changes in human airway smooth muscle cell (HASMC) migration and related signaling pathway after interference with PTEN gene expression. METHOD: HASMCs were infected with an adenovirus vector and RNA interference vector of human PTEN gene to establish the cell model with PTEN gene over-expression (Ad-GFP-PTEN-HASMC) and one with PTEN gene silencing (Ad-shPTEN-HASMC), using Ad-GFP-infected and a blank cells as the negative controls and LY294002 as the positive control. Fluorescence microscopy and flow cytometric analysis were used to evaluate the transfection efficiency, and Western blotting was performed to examine the expression of PTEN and the activation of AKT and ERK1/2 signal pathway. Transwell assay and wound healing assay were used to assess the migration of HASMCs. RESULTS: The adenovirus over-expression vector and RNA interference vector significantly affected the expression of human PTEN gene. Up-regulation of PTEN gene resulted in a slow-down of the HASMC migration, an inhibition of PI3K/AKT signal pathway at the protein level but no changes in Ras-Raf-MEK1/2-ERK1/2 signal pathway. Down-regulated PTEN gene expression, however, was not associated with an enhancement of HASMC migration, but activated PI3K/AKT signal pathway and inhibited Ras-Raf-MEK1/2-ERK1/2 signal pathway. CONCLUSION: Upregulation of PTEN gene can effectively inhibit airway smooth muscle cell migration, the effect of which is probably mediated by the PI3K/AKT pathway.

The generation of the endothelial specific cdc42-deficient mice and the effect of cdc42 deletion on the angiogenesis and embryonic development.

BACKGROUND: High microvascular permeability plays an essential role in pathological process of multiple diseases such as septic shock, acute lung injury and acute respiratory distress syndrome, and burns. Inhibiting hyperpermeability is significant for controlling these conditions. Cdc42, as a main member of the small Rho GTPase family, plays a critical role in controlling and regulating the endothelial junctional permeability. We aimed to generate and identify endothelial specific cdc42-deficient mice by the Cre/loxp recombination approach, for examination in an animal model of the contribution of the cdc42 gene in the microvascular barrier function. METHODS: We crossed cdc42(Flox/Flox) mice with mice expressing endothelial cell-specific Cre recombinase, and the offspring with the genotype cdc42(Flox/+)Tie2Cre(+/-) were back-crossed with the cdc42(Flox/Flox) mice. The cdc42(Flox/Flox)Tie2Cre(+/-) mice in the F2 generation were the target mice. If the cdc42 deficient mice did not survive, we would observe the cdc42 deficient mice embryos, and compare them with wild-type mice embryos. RESULTS: Cdc42(flox/+)Cre(+/-) mice were mated with the cdc42(Flox/Flox) mice and among the living offspring there were no cdc42(Flox/Flox)Cre(+/-) target mice. We found the endothelial special cdc42 deficient embryos at the E7.5-E16.5 stage. We observed that cdc42 deficient embryos were much smaller, had fewer vessels and were a little more swollen compared with the wild-type embryos. CONCLUSIONS: Endothelial specific knockout of cdc42 caused embryonic lethality and the mice did not survive to birth. The target embryos were much smaller, had fewer vessels and were a little more swollen compared with the wild-type embryos. These results demonstrated that the cdc42 plays an important role in development of embryos and in development of microvessels as well as microvascular permeability.

ISO-1, a macrophage migration inhibitory factor antagonist, inhibits airway remodeling in a murine model of chronic asthma.

Airway remodeling is the process of airway structural change that occurs in patients with asthma in response to persistent inflammation and leads to increasing disease severity. Drugs that decrease this persistent inflammation play a crucial role in managing asthma episodes. Mice sensitized (by intraperitoneal administration) and then challenged (by inhalation) with ovalbumin (OVA) develop an extensive eosinophilic inflammatory response, goblet cell hyperplasia, collagen deposition, airway smooth muscle thickening, and airway wall area increase, similar to pathologies observed in human asthma. We used OVA-sensitized/challenged mice as a murine model of chronic allergic airway inflammation with subepithelial fibrosis (i.e., asthma). In this OVA mouse model, mRNA and protein of macrophage migration inhibitory factor (MIF) are upregulated, a response similar to what has been observed in the pathogenesis of acute inflammation in human asthma. We hypothesized that MIF induces transforming growth factor-ß1 (TGF-ß1) synthesis, which has been shown to play an important role in asthma and airway remodeling. To explore the role of MIF in the development of airway remodeling, we evaluated the effects of an MIF small-molecule antagonist, (S,R)3-(4-hy-droxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1), on pathologies associated with the airway-remodeling process in the OVA mouse model. We found that administration of ISO-1 significantly mitigated all symptoms caused by OVA treatment. In addition, the treatment of OVA-sensitized mice with the MIF antagonist ISO-1 significantly reduced TGF-ß1 mRNA levels in pulmonary tissue and its protein level in bronchial alveolar lavage fluid supernatants. We believe the repression of MIF in the ISO-1 treatment group led to the significant suppression observed in the inflammatory responses associated with the allergen-induced lung inflammation and fibrosis in our murine asthma (OVA) model. Our results implicate a possible function of MIF in the pathogenesis of chronic asthma and suggest that MIF might be an important therapeutic target for airway remodeling.

[Effects of dexamethasone on expression of Th17 transcription factor RORgammat mRNA in experimental asthma mice.].

AIM: To study the effects of dexamethasone (Dex) on expression of Th17 transcription factor retinoic acid-related orphan receptor gamma t(RORgammat)in asthma. METHODS: The BALB/c mice asthma model was induced by ovalbumin(OVA) with classic method.Thirty female mice were randomly divided into control group, asthmatic group and Dex treated group. The level of IL-17 in mice bronchoalveolar lavage fluid (BALF) and serum was measured by enzyme-linked immunosorbent assay(ELISA). Airway Responsiveness to acetylcholine chloride(Ach) was measured by a modified non-invasive method; The airway inflammation was evaluated by HE staining.The expression of RORgammat mRNA was measured by reverse transcription-polymerase chain reaction(RT-PCR). RESULTS: The level of RORgammat mRNA, IL-17 of asthmatic group were significantly higher than those of control group(P<0.01), which were significantly reduced by Dex compared with the asthmatic group(P<0.05). CONCLUSION: Dex can inhibit the release of IL-17, whose mechanism may be the blockade of TH17 differentiation in asthmatic models by inhibit the RORgammat expression.

[Effect of recombinant adenovirus carrying PTEN gene on the proliferation of human airway smooth muscle cells in vitro and the mechanisms].

OBJECTIVE: To observe the effect of exogenous phophatase and tensin homolog deleted on chromosone 10 (PTEN) gene transfer via recombinant adenoviruses on the proliferation of human airway smooth muscle cells (HASMCs) in vitro and investigate the possible mechanisms. METHODS: With a recombinant adenovirus vector containing PTEN (Ad-PTEN) constructed using the pAdxsi system, PTEN gene was transiently transfected into HASMCs and the transfection efficiency was determined by fluorescence microscope. RT-PCR and Western blotting were performed to detect the expression of PTEN mRNA and protein in the infected cells. MTS/PMS assay was used to analyze the proliferation of HASMCs, and the cell cycle changes of the transfected cells were evaluated by flow cytometry with PI staining. The expression levels of Akt and p-A kt proteins were detected by Western blotting, and P21 mRNA expression determined by RT-PCR. RESULTS: The recombinant adenovirus Ad-PTEN showed a wild-type PTEN gene transfer efficiency of 98% at the multiplicity of infection (MOI) of 100. RT-PCR and Western blotting showed that infection with the recombinant adenovirus resulted in PTEN overexpression in the HASMCs, causing also increased ratio of G(0)/G(1) cells and proliferation inhibition of the ASMCs. The overexpression of PTEN significantly decreased the expression level of p-Akt but increased P21 mRNA expression. CONCLUSION: The recombinant adenovirus containing PTEN can be successfully transfected into HASMCs cultured in vitro, resulting in PTEN overexpression at both the mRNA and protein levels. PTEN overexpression can efficiently inhibit the proliferation of HASMCs possibly through the PI3K/PKB/AKt and P21 pathways.

[Effects of dexamethasone on intracellular expression of Th17 cytokine interleukin 17 in asthmatic mice].

OBJECTIVE: To study the effects of dexamethasone on intracellular expression of Th17 cytokine interleukin 17 and the mechanisms in asthmatic mice. METHODS: Experimental asthma was induced by ovalbumin (OVA) sensitization in 20 in female Balb/c mice with (dexamethasone group, n=10) or without dexamethasone treatment (model group, n=10), with another 10 serving as the control group. The levels of IL-17 in the bronchoalveolar lavage fluid (BALF) and serum of the mice were measured by enzyme-linked immunosorbent assay (ELISA), and the airway inflammation was evaluated by HE staining. The expressions of IL-17 and RORgammat mRNA were measured by reverse transcription-polymerase chain reaction (RT-PCR), and the expression of RORgammat protein was measured by immunohistochemical staining. RESULTS: The levels of RORgammat and IL-17 mRNA and protein in the asthmatic model group were significantly higher than those in the control group (P<0.01), and the increased expressions of RORgammat and IL-17 mRNA and protein in the asthmatic mice were significantly reduced by dexamethasone treatment (P<0.05). CONCLUSION: Dexamethasone can inhibit the release of IL-17 probably by inhibiting RORgammat expression and blocking Th17 differentiation in asthmatic mice.

[Construction of a recombinant adenovirus vector containing PTEN and its expression in airway smooth muscle cells].

OBJECTIVE: To construct a recombinant adenovirus vector containing phosphatase and tensin homolog deleted on chromosome 10 (PTEN) using the pAdxsi system. METHODS: PTEN cDNA from plasmid pcDNA3-PTEN was cloned into the shuttle plasmid pShuttle-GFP-CMV. The shuttle vector was transformed into competent DH5alpha strain with the vector pAdxsi to achieve the homologous recombination. The recombinant construct was subsequently linearized with PacI and transfected into HEK293 cells via Lipofectamine 2000. The recombinant adenovirus particles were collected, and after titration, the recombinant adenovirus was traced by monitoring GFP expression under fluorescence microscope. The expression of PTEN mRNA and protein in the recombinant adenovirus vector and airway smooth muscle cells were detected by PCR and Western blotting, respectively. RESULTS: GFP was expressed in HEK293 cells infected by recombinant adenovirus, and the expression intensity increased gradually with the passage of time, with obvious cytopathic effect (CPE) noted in the cells. After 3 cycles of amplification, the titer of adenovirus containing PTEN reached an appropriate level. The viral titer of pAdxsi-GFP-PTEN was 2x10(10) pfu/ml, and PTEN mRNA expression was detected by PCR. The homologous protein expressed in the infected human airway smooth muscle cells significantly increased in comparison with that in the control cells. CONCLUSION: The recombinant adenovirus containing PTEN is constructed successfully, which provides an experimental basis for studying the role of PTEN gene in asthma therapy.

[Rho-kinase signaling pathway participates in endothelin-1-induced human airway smooth muscle cell migration and cytoskeletal reorganization].

OBJECTIVE: To investigate the role of Rho-kinase signaling pathway in human airway smooth muscle cell (ASMCs) migration and cytoskeletal reorganization induced by endothelin-1 (ET-1). METHODS: Primary cultured human ASMCs obtained by tracheal explant culture method were examined for cell migration in response to ET-1 treatment using modified Boyden chambers. The changes in actin cytoskeletal reorganization were observed under confocal laser scanning microscope, and the phosphorylation of myosin-phosphatase target 1 (p-MYPT1) was examined using Western blot analysis. RESULTS: At the concentration of 0.1, 1, 10, and 100 nmol/L, ET-1 induced migration of the ASMCs, and 10 nmol/L ET-1 produced the most obvious effect (P<0.01). Rho-kinase inhibitor Y-27632 showed a dose-dependent inhibitory effect on ET-1-induced ASMC migration, and in cells exposed to 10 nmol/L ET-1, Y-27632 at 10 micromol/L significantly blocked ASMC migration (P<0.01). ET-1 (10 nmol/L) exposure resulted in reorganization of actin cytoskeleton and formation of stress fibers in the ASMCs, which were obviously inhibited by Y-27632. Compared with the control group, the AMSCs showed significant enhancement of p-MYPT1 protein expression after ET-1 exposure for 15 and 30 min (P<0.01), but prolonged exposure failed to result in the expression enhancement (P>0.05). CONCLUSION: Rho-kinase signaling pathway may play an important role in ET-1-induced ASMC migration and reorganization of actin cytoskeleton.

[Peripheral natural killer cell counting and its clinical significance blood in patients with bronchial asthma].

OBJECTIVE: To investigate the changes in natural killer (NK) cell count in the peripheral blood of asthmatic patients. METHODS: The number of NK cells in the peripheral blood was determined with flow cytometry in 63 asthmatic patients with acute episodes, 65 patients with stable asthma and 62 healthy nonatopic subjects. RESULTS: A significant decrease in NK cell number was noted in asthmatic patients during acute exacerbation [(13.9-/+9.4) %] in comparison with patients with stable asthma [(22.5-/+12.3) %] and healthy subjects [(19.6-/+10.1)%] (P<0.05), and the NK cell number showed no significant difference between the latter two groups (P>0.05). CONCLUSION: NK cell number is reduced in acute exacerbation of asthma, suggesting its important role in the asthmatic process.

[Shikonin inhibits the proliferation of human airway smooth muscle cells].

OBJECTIVE: To study the inhibitory effect of shikonin on the proliferation of human airway smooth muscle cells (HASMCs) in vitro. METHODS: HASMCs from the trachea were obtained by primary culture of the tissue explants and adherent culture. The HASMCs were exposed to shikonin at 0 (control group), 0.5, 1, 2, 5, 10, 20, and 40 micromol/L for 12, 24, and 48 h, after which the cell proliferation was assessed by 3-(4,5-carboxymethoxypheny1)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) colorimetric assay. Flow cytometry was used for cell cycle analysis of the HASMCs exposed to shikonin at 40, 20, 10, 5 micromol/L and 0 micromol/L (control group) for 24 h. Immunocytochemistry with SP method was performed to detect the expression of proliferating cell nuclear antigen (PCNA) in the HASMCs treated with shikonin at 20 micromol/L and 0 micromol/L (control group) for 24 h. RESULTS: Shikonin at the concentrations of 20 and 40 micromol/L significantly inhibited the proliferation of the cells (P<0.05), and the effect was especially obvious after 48 h of cell exposure, with inhibition rates of 30.1% and 42.9%, respectively. No significant difference was found between the two concentrations for their cell growth inhibition effects (P>0.05). Shikonin at the concentrations of 20 and 40 micromol/L caused significant cell cycle arrest in G(0)/G(1) phase (P<0.05), the effect of which, however, was not concentration-dependent (P>0.05). Shikohin at 20 micromol/L significantly down-regulated the expression of PCNA in the cells (P<0.05). CONCLUSION: Shikonin can inhibit the proliferation of HASMCs in vitro.

3,3'-Dibromo-1,1'-[(propane-1,3-diyl-dioxy)-bis(nitrilo-methyl-idyne)]dibenzene.

The mol-ecule of the title compound, C(17)H(16)Br(2)N(2)O(2), lies on a twofold axis that passes through the middle atom of the three-atom trimethyl-ene unit. The two aromatic rings are aligned at an angle of 76.02 (4)°.