Biomedical subjects
Publications and source records attributed to Qian Liu.
Highly-ordered, pore-modified with amine groups, and glass-like mesoporous silicon oxynitride thin films were prepared by heat treatment of as-synthesized mesoporous silica thin films in a flowing ammonia environment at high temperatures.
IL-4 and IL-13 are up-regulated during in vivo responses to many nematode parasites, but increasing evidence suggests that increases in IL-13 can also occur independently of the IL-4-dominant Th2 response. Blocking B7 after Trichuris muris inoculation inhibits resistance and IL-4 elevations, instead resulting in an IFN-gamma-dominant response associated with susceptibility. However, blocking IFN-gamma under these conditions restores IL-13-dependent resistance. In this study, we examined the mechanism of IL-13 up-regulation and associated protection during this in vivo immune response. CD4+ T cells and DX5+ TCR- cells were identified as the major producers of IL-13, and the DX5+ TCR- cells were phenotyped as NK cells, since they expressed CD11b, IL-2Rbeta and Ly49C but not c-kit or Fc epsilonRI. NK cell-derived IL-13 elevations were T cell-dependent, as CD4+ T cell depletion blocked IL-13 production by mesenteric lymph node cells and induced susceptibility. IL-13 expression was increased independently of IL-12; however, blocking IL-18 function inhibited IL-13 production and increased susceptibility. These results indicate that CD4+ T cells and NK cells are the major sources of IL-13 during the in vivo Th1 response induced by B7 blockade and that under these conditions, IL-18 is specifically required for the in vivo up-regulation of IL-13 production and associated host protection.
LIF detection is one of the most sensitive detection methods for CE. However, its application is limited because the analyte is usually required to be derivatized with a fluorescent label. As a result, LIF is seldom used to analyze active ingredients in plants. In this work, we introduce a rapid, simple, and sensitive method of nonaqueous CE (NACE) coupled with laser-induced native fluorescence detection for the simultaneous analysis of berberine, palmatine, and jatrorrhizine. This method skillfully utilizes the native fluorescence of these alkaloids and requires no troublesome fluorescent derivatization. As these alkaloids can fluoresce to some degree, they were simply detected by a commercially available 488 nm Ar+ laser. The native fluorescence of the analytes was greatly enhanced by nonaqueous media. Compared with the reported UV detection method, much lower LOD was achieved (6.0 ng/mL for berberine, 7.5 ng/mL for palmatine, and 380 ng/mL for jatrorrhizine). This method was successfully applied to analyze berberine, palmatine, and jatrorrhizine in two Chinese herbal medicines, Rhizoma coptidis and Caulis mahoniae.
To compare and evaluate two methodologies, entire-sampling and micro-sampling for the harvesting of vitreous humor, the vitreous humor of rabbits were sampled with the two methods respectively, and the concentrations of calcium, chlorine, potassium, sodium and phosphorus of the were measured. The results showed that the differences in the variance coefficient and two-eye concentrations of micro-sampled specimens were less than those of the entire-sampled specimens. In the micro-sampling group, the concentrations of repeated micro-sampling showed no differences among different groups (P > 0.05) and the intra-ocular fluid dynamics did not have significant influence on post-mortem sampling. The sampling technique may affect the concentrations of specimen collected. Our study suggests that micro-sampling is less influenced by the human factor and is reliable, reproducible, and more suitable for forensic investigation.
This paper reports the availability of a high-resolution atlas of the adult rat. The atlas is composed of 9475 cryosectional images captured in 4600 x 2580 x 24-bit TIFF format, constructed using serial cryosection-milling techniques. Cryosection images were segmented, labelled and reconstructed into three-dimensional (3D) computerized models. These images, 3D models, technical details, relevant software and further information are available at our website, http://vchibp.vicp.net/vch/mice/.
The filamentous cyanobacteria Planktothrix spp. occur in the temperate region of the Northern hemisphere. The red-pigmented Planktothrix rubescens bacteria occur in deep, physically stratified, and less eutrophic lakes. Planktothrix is a known producer of the toxic heptapeptide microcystin (MC), which is produced nonribosomally by a large enzyme complex consisting of peptide synthetases and polyketide synthases encoded by a total of nine genes (mcy genes). Planktothrix spp. differ in their cellular MC contents as well as the production of MC variants; however, the mechanisms favoring this diversity are not understood. Recently, the occurrence of Planktothrix strains containing all mcy genes but lacking MC has been reported. In this study, 29 such strains were analyzed to find out if mutations of the mcy genes lead to the inability to synthesize MC. Two deletions, spanning 400 bp (in mcyB; one strain) and 1,869 bp (in mcyHA; three strains), and three insertions (IS), spanning 1,429 bp (in mcyD; eight strains), 1,433 bp (in mcyEG; one strain), and 1,433 bp (in mcyA; one strain), were identified. Though found in different genes and different isolates and transcribed in opposite directions, IS were found to be identical and contained conserved domains assigned to transposable elements. Using mutation-specific primers, two insertions (in mcyD and mcyA) and one deletion (in mcyHA) were found regularly in populations of P. rubescens in different lakes. The results demonstrate for the first time that different mutations resulting in inactivation of MC synthesis do occur frequently and make up a stable proportion of the mcy gene pool in Planktothrix populations over several years.
OBJECTIVE: To study the pathogenesis of abnormal bone metabolism in patients with HBV liver cirrhosis. METHODS: NM-300 signal-energy X-ray absorptiometry system was used to measure the bone mineral density (BMD) in 61 liver cirrhosis patients and 30 age-matched healthy controls. The serum levels of 1,25(OH)2D3, parathyroid hormone (PTH), calcitonin (CT), bone gamma-carboxyglutamic acid-containing protein (BGP), IL-1beta, IL-6, tumor necrosis factor (TNF)alpha and urine crosslaps were also detected in these patients. RESULTS: BMD in patients with HBV liver cirrhosis was lower than those of the controls. The serum levels of 1,25(OH)2D3 and BGP in cirrhosis patients were lower than those in the controls, and they were much lower in the osteoporosis (OP) group than in the non-osteoporosis (NOP) group. The PTH and CT were higher significantly in the patients than in the controls. The changes of serum 1,25(OH)2D3 and BGP were correlated with the changes of BMD. The serum levels of IL-1beta, IL-6, TNFalpha and urine crosslaps in cirrhosis patients were higher than those of the controls, and they were much higher in the OP group than in the NOP group. We also found that the serum levels of IL-1beta, IL-6, TNFalpha and urine crosslaps had a negative correlation with BMD. CONCLUSIONS: These data suggest that bone formation is weakened and bone resorption is increased in patients with HBV liver cirrhosis, 1,25(OH)2D3 plays an important role in abnormal bone formation. Elevation of serum IL-1beta, IL-6, TNFalpha can accelerate bone resorption and cause hepatic bone disease (HBD). Taking 1,25(OH)2D3 and reducing the level of IL-1beta, IL-6, TNFalpha may be very important in preventing and treating HBD.
OBJECTIVE: To investigate the association between natural-resistance-associated macrophage protein 1 (NRAMP1) gene polymorphisms and susceptibility to pulmonary tuberculosis (TB) in Han nationality from Northern part of China. METHODS: A 1:1 matched case-control study was adopted. Polymerase chain reaction and restriction fragment length polymorphism technique were used to type the two NRAMP1 polymorphisms: INT4 and 3'UTR. Information on environmental-related risk factors and pathological changes of tuberculosis was collected using a pre-tested standard questionnaire. Univariate and multivariate conditional logistic analyses were conducted using SPSS for window software. RESULTS: A sample consisting 124 pairs of cases and controls was studied. Univariate analysis demonstrated that the 3'UTR TGTG+/del genotype occurred more frequently in the cases than in the controls, with crude OR (95% CI) being 2.923 (1.557 - 5.487). No significant association was observed between TB and INT4 polymorphism. In multivariate analysis, associations of TB and 3'UTR TGTG+/del genotype remained, after adjusting for scar of bacillus Calmette-Guérin vaccine, marriage status, body mass index and exposure history. Adjusted OR (95% CI) was 2.955 (1.369 - 6.381). Again, no significant association between INT4 polymorphism and TB was found. Among different INT4 genotypes, the pathological characters of pulmonary tuberculosis were also found different (chi(2) = 9.634, P < 0.05). CONCLUSION: Polymorphism of 3'UTR locus in NRAMP1 gene might affect their susceptibility to TB in Han nationality living in the northern part of China, and polymorphism of INT4 might affect the pathological characters of tuberculosis.
OBJECTIVE: To investigate the relationship between NDRG1 and metastasis of breast cancer and the effects of NDRG1 overexpression on the proliferation and invasion of breast cancer cells. METHODS: NDRG1 was detected at its protein level by immunohistochemistry (IHC) and its messenger RNA (mRNA) was detected by real-time reverse transcriptase-polymerase chain reaction (real time RT-PCR) in clinical breast cancer specimens. Liposome was used to transiently transfer NDRG1 into MDA-MB-231, a highly invasive human breast cancer cell line. The proliferation of MDA-MB-231 was measured by Bromodeoxy Uridine (BrdU) incorporation assay and the transfection effect on cell cycle distribution was determined by fluorescence assisted cell sorting (FACS). The invasive ability of the transfected cells was investigated by reconstituted matrigel invasion and polycarbonate filters migration experiments. RESULTS: NDRG1 expressions at protein and mRNA levels in tumors of patients with lymph node metastases were significantly lower as compared with those with localized breast cancers (P < 0.01). The amount of NDRG1 mRNA in MCF7, a relatively non-invasive breast cancer cell line, was 10.8 times higher than that in MDA-MB-231 cells (P < 0.01). The BrdU incorporation rate declined significantly (P < 0.05) in NDRG1 overexpressing MDA-MB-231 cells. An increase of the cell population at G(0)/G(1) phase was observed 48 hours post-transfection along with a decrease of cell population at S phase. Overexpression of NDRG1 significantly retarded the invasiveness of MDA-MB-231 cells in matrigel-coated invasion chambers (P < 0.05), when compared to cells transfected with control vectors. However, the migration abilities of cells with or without the transfection were virtually identical. CONCLUSIONS: NDRG1 expression reversely correlates with breast cancer metastasis and progression, and may serve as a prognostic biomarker for predicting early metastasis. The inhibition of proliferation and invasion demonstrated by our MDA-MB-231 transfection experiments implies that NDRG1 is a tumor metastasis suppressor gene and may be a new candidate for gene therapy against human breast cancer.
OBJECTIVE: To investigate the root canal curvature in Chinese mandibular permanent incisors. METHODS: Two hundred and ninety nine Chinese mandibular permanent incisors were included in this study. The root canals were inserted with stainless steel 15# K files, and then taken radiography from the facial and proximal view by X-ray paralleling technique. Canal curvatures were evaluated by measuring the angle, the radius of the curvatures, and the length of the curved part of the canal. Based on the curved angle and the shape of curved canals, the root canals were classified. RESULTS: The curved angle, radius, and the curved canal length was 5.28 degrees +/- 5.52 degrees, 16.19 mm +/- 12.38 mm, 4.10 mm+/-2.01 mm, respectively in the facial view; 9.99 degrees +/- 5.84 degrees, 18.86 mm +/- 9.71 mm, 3.27 mm +/- 2.39 mm, respectively in the proximal view. The prevalence of straight, light, moderate, and serve curved root canals in mandibular permanent incisors was 15.7%, 66.9%, 16.7%, and 0.7%, respectively (P<0.05) based on the curved angle. The prevalence of straight, L shape, and S shape curved root canals was 7.7%, 50.5%, and 41.8%, respectively (P < 0.05). CONCLUSION: Most of the root canals in mandibular permanent incisors are curve.
Lactobacillus L15, a strain of Lactobacillus sp. isolated from the intestinal tract of healthy Paralichthys olivaceus, and Lactobacillus acidlophilus ATCC4356 were used to investigate their specific adhesions. It was shown that cell surface proteins of two strains could be extracted by 5 mol/L lithium chloride( LiCl). Two surface proteins with molecular weights of 61.8 kDa and 54.6 kDa were identified to mediate the adhesion to intestinal mucus of Paralichthys olivaceus and Common carp respectively by the method of Western blotting, and the two novel proteins were named as MAPPpo1 and MAPPcc. In Lactobacillus acidlophilus ATCC4356, two proteins of 43.0 kDa and 63.3 kDa were identified to mediate the adhesion to intestinal mucus of Paralichthys olivaceus. Nevertheless, only 43.0 kDa protein was identified to mediate the adhesion to intestinal mucus of Common carp. Furthermore, the mucus proteins which participated the adhesion as the bacteria receptors were identified by the same method and it was found that L15 and ATCC4356 had the same receptors.There were 29.7 kDa and 30.3 kDa proteins in the intestinal mucus of Paralichthys olivaceus and only the 26.2 kDa protein was testified in the intestinal mucus of Common carp. It is demonstrated that the adhesion of Lactobacillus to mucus is dependent on the strain specificity, as well as host specificity.
OBJECTIVE: To improve the effects of diagnosis and therapy in patients with tracheobronchial foreign body who were diagnosed as pneumonia and to summarize the experience. METHOD: Foreign bodies in the trachea and bronchi in one hundred and seventy-two children were removed in our hospital from 1995. 2 to 2005. 2, of them 67 cases were diagnosed as pneumonia. RESULT: Our experience showed that the foreign body in tracheobronchial had an increasing tendency in recent years, and it had a descendant tendency that it be diagnosed as pneumonia. The time of the patients suffered from foreign bodies was from 5 days to 8 months, and the children under 2 years accounted for 80.6%. The most common foreign body was peanuts, accounting for 70.4%. All the foreign bodies were removed by rigid bronchoscopy. The successful rate of removal at first time was 63 cases, accounting for 94%. The reason of failure at first time was anesthesia (2 cases). There was no case of death. No cases underwent tracheotomy. CONCLUSION: The foreign body in tracheobronchial can be easily diagnosed as pneumonia. We should reduce the rate of erroneous diagnosis. Rigid bronchoscopy for removing foreign bodies under general anesthesia is still the main measure at present.
The nuclear envelope defines the barrier between the nucleus and cytoplasm and features inner and outer membranes separated by a perinuclear space (PNS). The inner nuclear membrane contains specific integral proteins that include Sun1 and Sun2. Although the outer nuclear membrane (ONM) is continuous with the endoplasmic reticulum, it is nevertheless enriched in several integral membrane proteins, including nesprin 2 Giant (nesp2G), an 800-kD protein featuring an NH(2)-terminal actin-binding domain. A recent study (Padmakumar, V.C., T. Libotte, W. Lu, H. Zaim, S. Abraham, A.A. Noegel, J. Gotzmann, R. Foisner, and I. Karakesisoglou. 2005. J. Cell Sci. 118:3419-3430) has shown that localization of nesp2G to the ONM is dependent upon an interaction with Sun1. In this study, we confirm and extend these results by demonstrating that both Sun1 and Sun2 contribute to nesp2G localization. Codepletion of both of these proteins in HeLa cells leads to the loss of ONM-associated nesp2G, as does overexpression of the Sun1 lumenal domain. Both treatments result in the expansion of the PNS. These data, together with those of Padmakumar et al. (2005), support a model in which Sun proteins tether nesprins in the ONM via interactions spanning the PNS. In this way, Sun proteins and nesprins form a complex that links the nucleoskeleton and cytoskeleton (the LINC complex).
The pituitary hormone prolactin (PRL) regulates salt and water homeostasis by altering ion retention and water uptake through peripheral osmoregulatory organs. To understand the role of osmotic homeostasis in the development of PRL-secreting lactotrophs, we generated germline transgenic zebrafish coexpressing red fluorescent protein directed by Prolactin regulatory elements (PRL-RFP) and green fluorescent protein by the Pro-opiomelanocortin promoter (POMC-GFP). Transparent embryos expressing fluorescent markers specifically targeted to lactotrophs and corticotrophs, the two pituitary lineages involved in teleost osmotic adaptation, allowed in vivo dynamic tracing of pituitary ontogeny during altered environmental salinity. Physiological osmotic changes selectively regulate lactotroph but not corticotroph proliferation during early ontogeny. These changes are not suppressed by pharmacological dopamine receptor blockade but are completely abrogated by morpholino knockdown of the PRL receptor. PRL receptor signaling exerts robust effects on lactotroph development and plays a permissive role in lactotroph osmo-responsiveness, reflecting the dual peripheral and central interactions required for early pituitary development and embryonic homeostasis.
A biosensor based on chitosan doped with carbon nanotube (CNT) was fabricated to detect salmon sperm DNA. Methylene blue (MB) was employed as a DNA indicator. It was found that CNTs can enhance the electroactive surface area threefold (0.28 +/- 0.03 and 0.093 +/- 0.06 cm(2) for chitosan-CNT- and chitosan-modified electrodes, respectively) and can accelerate the rate of electron transfer between the redox-active MB and the electrode. A low detection limit of 0.252 nM fish sperm DNA was achieved, and no interference was found in the presence of 5 microg/ml human serum albumin. The differential pulse voltammetry signal of MB was linear over the fish sperm DNA concentration range of 0.5-20 nM.
The intestinal nematode parasite, Nippostrongylus brasiliensis, triggers potent type 2 immunity. Using OVA peptide as a model Ag, we have examined the adjuvant effects of this parasite on the in vivo development of Ag-specific Th2 cells from naive DO11.10 T cells. Our findings show that Th2 cells can develop from transferred naive OVA-specific DO11.10 T cells in recipient IL-4-/- mice inoculated with N. brasiliensis plus OVA. However, autocrine IL-4 is required for in situ Th2 cell differentiation since transferred IL-4Ralpha-deficient DO11.10 T cells showed greatly reduced Th2 cell development in inoculated IL-4-/- recipient mice. Surprisingly, we also found that IL-2 blockade promoted B7-dependent T cell cycling, but inhibited the development of OVA-specific Th2 cells. Furthermore, the effects of IL-2 occurred independently of CD25+ T regulatory cells. These studies establish a previously unrecognized requirement for autocrine IL-4 and IL-2 in Th2 responses elicited by nematode parasites.
In this work, CE separation with end-column Ru(bpy)3(2+) ECL detection for the quantitative determination of pentoxyverine was firstly performed. The experimental conditions, such as the applied potential, injection voltage, injection time, and the pH of separation buffer, were discussed in detail. Gold nanoparticles were found to enhance the ECL intensity at an appropriate volume ratio of nanogold with Ru(bpy)3(2+) but without changing their nanoproperties proved by transmission electron microscopy (TEM) and UV-vis spectra. The detection limits with or without nanogold were 6 nM and 0.6 microM, respectively. Successful separation of pentoxyverine, chlorpheniramine, and lidocaine was achieved. This method was also applied to monitor drug binding with HSA, and the binding constant for pentoxyverine was estimated as 1.8 x 10(3)/M.
A new SARS animal model was established by inoculating SARS coronavirus (SARS-CoV) into rhesus macaques (Macaca mulatta) through the nasal cavity. Pathological pulmonary changes were successively detected on days 5-60 after virus inoculation. All eight animals showed a transient fever 2-3 days after inoculation. Immunological, molecular biological, and pathological studies support the establishment of this SARS animal model. Firstly, SARS-CoV-specific IgGs were detected in the sera of macaques from 11 to 60 days after inoculation. Secondly, SARS-CoV RNA could be detected in pharyngeal swab samples using nested RT-PCR in all infected animals from 5 days after virus inoculation. Finally, histopathological changes of interstitial pneumonia were found in the lungs during the 60 days after viral inoculation: these changes were less marked at later time points, indicating that an active healing process together with resolution of an acute inflammatory response was taking place in these animals. This animal model should provide insight into the mechanisms of SARS-CoV-related pulmonary disease and greatly facilitate the development of vaccines and therapeutics against SARS.