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Q Cao

Publications and source records attributed to Q Cao.

At least 19 recordsLinked to original sources

Nestin expression in Müller glial cells in postnatal rat retina and its upregulation following optic nerve transection.

This study examined the nestin immunoexpression and its specific cellular localization in the developing retina of rats and investigated its putative changes in an altered environment. At postnatal day 0, nestin immunoexpression was detected in radially oriented cells considered to be neural progenitors that were glutamine synthetase (GS) negative. With age, it was localized in differentiating and differentiated GS positive Müller glial cells. Nestin expression was down-regulated as maturation proceeded, so that by 12 weeks, it was almost completely diminished as confirmed also by real time-polymerase chain reaction analysis. Nestin expression along with that of glial fibrillary acidic protein (GFAP) was induced and upregulated in mature Müller glial cells following optic nerve transection. It is suggested that both nestin and GFAP may be useful biomarkers in retinal injuries. In view of their cytoskeletal nature, the marked expression of nestin and GFAP may provide a structural support for the framework of retina which would be disrupted as a result of loss of neurons in optic nerve lesion. It may also be neuronal protective taking into consideration the close spatial and functional links between Müller glial cells and the axotomized ganglion cells.

Age Factors↗

Expression of 2',3'-cyclic nucleotide 3'-phosphodiesterase in the amoeboid microglial cells in the developing rat brain.

Expression of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) in amoeboid microglial cells (AMC) in developing rat brain from prenatal day 18 (E18) to postnatal day 10 (P10) was demonstrated by immunohistochemistry/immunofluorescence and immunoelectron microscopy both in vivo and in vitro, respectively. Furthermore, real time-polymerase chain reaction (PCR) was performed to determine the expression of CNPase at mRNA level in cultured microglial cells in control conditions and following lipopolysaccharide stimulation. CNPase immunoreactive amoeboid microglia occurred in large numbers in the corpus callosum, subventricular zone and cavum septum pellucidum at P0 but were progressively reduced with age and were undetectable at P14. By immunoelectron microscopy, immunoreaction product was associated primarily with the plasma membrane, filopodial projections and mitochondria in AMC. Real time-PCR analysis revealed that CNPase mRNA was expressed by cultured amoeboid microglia and was significantly up-regulated in microglial activation induced in vitro by lipopolysaccharide. The functional role of CNPase in AMC remains speculative. Given its expression in AMC transiently occurring in the perinatal brain and that it is markedly elevated in activated microglia, it is suggested that the enzyme may be linked to the major functions of the cell type such as release of chemokines and cytokines. In relation to this, CNPase may play a key role associated with transportation of cytoplasmic materials.

2',3'-Cyclic Nucleotide 3'-Phosphodiesterase↗

Müller glial cells express nestin coupled with glial fibrillary acidic protein in experimentally induced glaucoma in the rat retina.

This study was aimed to investigate reactive changes of Müller glial cells in rats subjected to experimentally induced glaucoma. In the latter, it is well documented that elevated intraocular pressure leads to the loss of ganglion cells as confirmed in this study. The present results have shown that Müller glial cells as well as astrocytes closely associated with the ganglion cells reacted vigorously to increased intraocular pressure as manifested by the induced and upregulated expression of nestin and glial fibrillar acidic protein. A major finding in glaucomatous rats was the induced expression of nestin together with glial fibrillar acidic protein with the rise of the intraocular pressure beginning at 2 h. The marked nestin expression appeared to be most intense at 1 week after operation and was sustained at 3 weeks. Induced nestin expression in Müller glial cells was demonstrated unequivocally in whole-mount preparation of the retina. In the same tissue preparation, nestin expression was also detected in some astrocytes. Western blotting analysis confirmed a marked increase in expression of nestin and glial fibrillar acidic protein. Present results suggest that nestin as well as glial fibrillar acidic protein is a useful biomarker for retina injury. The induced expression of these intermediate filament proteins in Müller glial cells especially at their end-feet and also in some astrocytes adjoining the neuronal injury suggests a potential neuroprotective mechanism in response to acute rise in intraocular pressure resulting in neuronal degeneration.

Animals↗

Clinical and cytogenetic features of 508 Chinese patients with myelodysplastic syndrome and comparison with those in Western countries.

Myelodysplastic syndrome (MDS) is a clonal hematopoietic stem cell disorder characterized by ineffective hematopoiesis and leukemia progression. Racial differences may exist on clinical pictures and the molecular events leading to MDS, which are heterogeneous. To better define the clinical and cytogenetic features in Chinese patients, a retrospective multicentric study was performed in 508 MDS cases. Compared with Western countries, Chinese patients showed younger age (median: 49 vs 65-73 years), lower percentages of RARS (2.8 vs 6.6-15.3%), and CMML (5.2 vs 11.7-30.6%). Cytogenetically, among 367 cases with evaluable data, abnormal karyotypes were found in 136 cases, including 56 numerical and 80 structural changes. Incidences of single chromosome 5 and 7 abnormalities were lower than those in Western countries (2.2 vs 17.8-42.5%). However, complex cytogenetic aberrations and chromosome translocations were frequently observed and related to poor prognosis. Both multiple chromosome deletions and translocations were detected in advanced subtypes (RAEB and RAEB-T). Analysis of 200 cases revealed a higher incidence of hepatitis-B-virus infection than that in non-MDS population (21.00 vs 9.75%). This study further confirmed: (1) different genetic/environmental backgrounds between Asian and Western MDS populations; (2) a strong predictive value of cytogenetic abnormalities on disease outcome and involvement of genomic instability in leukemia clone development.

Adolescent↗

Linkage analysis of schizophrenia to chromosome 15.

We have mapped a sample of 68 families consisting of one or more affected sibling pairs with schizophrenia or schizoaffective disorder with 20 markers spanning all of chromosome 15 to investigate whether there is a locus on chromosome 15 that confers an increased susceptibility to schizophrenia using parametric and nonparametric linkage analyses. Allele sharing identical by descent and multipoint maximum likelihood score (MLS) statistics were employed. Results show excess allele sharing for multiple markers in 15q11.2-q25, a chromosomal region previously found linked to a decrease in the normal inhibition of the P50 auditory-evoked response to the second of paired stimuli, a decrease associated with schizophrenia. Excess allele sharing was found for markers spanning about 48 cM in 15q11.2-q25 (D15S1002-D15S1023). The greatest single point allele sharing was found at D15S659 (62.6%). The multipoint MLS scores were greater than 1.0 in the 30-52 cM interval delimited by ACTC and D15S150, with a maximum value of 2.0 with GENEHUNTER PLUS near D15S1039.

Alleles↗

The novel taxane analogs, BMS-184476 and BMS-188797, potentiate the effects of radiation therapy in vitro and in vivo against human lung cancer cells.

PURPOSE: To evaluate the novel taxane analogs, BMS-184476 and BMS-188797, as potential radiosensitizers in vitro and in vivo. METHODS AND MATERIALS: Human H460 lung cancer cells were incubated with either paclitaxel or a taxane analog and irradiated at various times. Surviving fractions were then determined using a clonogenic assay. Three different schedules were used: (A) 1-h drug incubation with radiation at t = 8 h, (B) 1-h drug incubation with radiation at t = 24 h, (C) 24-h drug incubation with radiation immediately after. Cell cycle redistribution by taxanes alone was measured with propidium iodide and flow cytometry. Percent apoptosis was also measured using 7-aminoactinomycin D (7-AAD) staining with flow cytometry. For in vivo studies, H460 cell xenografts were used in nude mice. Tumors were grown s.c. on the flank and then treated with BMS-184476 (10 mg/kg i.p. injection, Days 0, 2, and 4) and/or radiation (2 Gy/day, Days 0-4). Tumor growth delay was then measured for each treatment group. RESULTS: The mean in vitro radiation dose enhancement ratios of BMS-184476, BMS-188797, and paclitaxel were 1.76, 1.49, and 1.31 for Schedules A, B, and C, respectively. Isobologram analysis showed that BMS-184476 was synergistic with radiation using Schedule A. Treatment with taxanes caused an increase in the percentage of G2/M cells at the time of irradiation. The mean fold increases in the %G2/M above control values for all three drugs were 5.6, 2.5, and 1.7 for Schedules A, B, and C, respectively. The combined effects of taxanes plus radiation on the induction of apoptosis were additive for all three drugs. In vivo studies showed that BMS-184476 can enhance the effects of fractionated radiotherapy, with an average enhancement factor of 1.66 obtained from three independent experiments. CONCLUSIONS: These results demonstrated that the novel taxane analogs, BMS-184476 and BMS-188797, can enhance the effects of radiation in human lung cancer cells both in vitro and in vivo. These data also support the hypothesis that a G2/M block is involved in the radiosensitization caused by the taxanes.

Antineoplastic Agents, Phytogenic↗

Osmotic stress induced by carbohydrates enhances expression of foreign proteins in Escherichia coli.

Arabinose has been serendipitously observed to enhance the expression of P450s in Escherichia coli. To understand the mechanism of this arabinose-dependent enhancement, the effects of various carbohydrates were investigated. Surprisingly, a series of sugars, including pentoses and hexoses, enhanced the foreign gene expression in a manner similar to arabinose. Furthermore, glycerol, a poor carbon source, also enhanced P450 expression. These results indicate that the enhancement is independent of the specific efficiency of the carbon source and also suggest the involvement of osmotic stress. Therefore, the effect of the sigma(s) (also termed sigma(38)) factor, a sigma subunit of RNA polymerase that plays a central role in regulating the expression of osmotic stress response genes, has been examined. We found that the glycerol-dependent increase in P450 expression was not observed in sigma(s)-deficient E. coli, indicating that carbohydrates enhance the foreign gene expression in E. coli via the induction of the osmotic stress response. The results suggest the important role of the osmotic stress response in posttranscriptional processes required for producing functional proteins.

Arabinose↗

A genetic factor for age-related cataract: identification and characterization of a novel galactokinase variant, "Osaka," in Asians.

Galactokinase (GALK) deficiency is an autosomal recessive disorder characterized by hypergalactosemia and cataract formation. Through mass screening of newborn infants, we identified a novel and prevalent GALK variant (designated here as the "Osaka" variant) associated with an A198V mutation in three infants with mild GALK deficiency. GALK activity and the amount of immunoreactive protein in the mutant were both 20% of normal construct in expression analysis. The K(m) values for galactose and ATP-Mg(2+) in erythrocytes with homozygous A198V were similar to those of the healthy adult control subjects. A population study for A198V revealed prevalences of 4.1% in Japanese and 2.8% in Koreans, lower incidence in Taiwanese and Chinese, no incidence in blacks and whites from the United States, and a significantly high frequency (7.8%; P < .023) in Japanese individuals with bilateral cataract. This variant probably originated in Japanese and Korean ancestors and is one of the genetic factors that causes cataract in elderly individuals.

Adult↗

Genetic diversity of the human serotonin receptor 1B (HTR1B) gene.

We systematically and comprehensively investigated polymorphisms of the HTR1B gene as well as their linkage disequilibrium and ancestral relationships. We have detected the following polymorphisms in our sample via denaturing gradient gel electrophoresis, database comparisons, and/or previously published assays: G-511T, T-261G, -182INS/DEL-181, A-161T, C129T, T371G, T655C, C705T, G861C, A1099G, G1120A, and A1180G. The results of the intermarker analyses showed strong linkage disequilibrium between the C129T and the G861C polymorphisms and revealed four common haplotypes: ancestral (via chimpanzee comparisons), 129T/861C, -161T, and -182DEL-181. The results of association tests with schizophrenia were negative, although A-161T had a nominal P = 0.04 via ASPEX/sib_tdt. The expressed missense substitutions, Phe124Cys, Phe219Leu, Ile367Val, and Glu374Lys, could potentially affect ligand binding or interaction with G proteins and thus modify drug response in carriers of these variants. On average, the human cSNPs and differences among other primates clustered in the more thermodynamically unstable regions of the mRNA, which suggests that the evolutionary survival of nucleotide sequence variation may be influenced by the mRNA structure of this gene.

Alleles↗

Transcatheter closure of atrial septal defects and patent foramen ovale under intracardiac echocardiographic guidance: feasibility and comparison with transesophageal echocardiography.

Transesophageal echocardiography (TEE) has been employed successfully for guiding transcatheter device closure of secundum atrial septal defect (ASD) and patent foramen ovale (PFO). However, the use of TEE for device closure requires general anesthesia. Intracardiac echocardiography (ICE) can provide similar anatomical views that might replace the use of TEE for device closure. Eleven patients (eight female/three male) with secundum ASD and PFO associated with strokes underwent attempts at transcatheter closure of their defects under sequential TEE and ICE guidance (six patients) and under ICE alone (five patients). The ages of the patients ranged from 6.6 to 74.7 yr, and their weights ranged from 23 to 124.5 kg. The sizes of the defects, as measured by TEE (six patients), ranged from 3 to 27 mm and, as measured by ICE (11 patients), from 3 to 27 mm. The balloon-stretched diameter of the ASD, as measured by TEE (six patients), ranged from 16 to 38 mm and, as measured by ICE (11 patients), from 16 to 35 mm. Both techniques correlated well for the measured two-dimensional diameter and for the balloon-stretched diameter (r = 0.97 and 0.98, respectively). Both TEE and ICE provided similar views of the defects and the various stages of device deployment. Owing to the proximity of the left atrium to the esophagus, however, the images obtained by ICE were more helpful and informative than those obtained by TEE. All patients experienced successful device placement (six patients under both TEE and ICE; five patients under ICE guidance alone); complete closure of the defects was effected in nine patients, whereas two patients had small residual shunts. There were no complications. We conclude that ICE provides unique images of the atrial communications and measurements similar to those obtained by TEE. ICE potentially could replace TEE as a guiding imaging tool for ASD and PFO device closure, thus eliminating the need for general anesthesia.

Adolescent↗

Lipid peroxidation in the postnatal rat brain. Formation of 4-hydroxynonenal in the supraventricular corpus callosum of postnatal rats.

Lipid peroxidation is known to be associated with many neurodegenerative diseases and with traumatic brain injury, but its occurrence in the normal developing brain has not been reported. The present study was carried out using a specific antibody that recognises proteins modified by the end-product of lipid peroxide decomposition, 4-hydroxynonenal (HNE), to evaluate evaluate possible lipid peroxidation products in the brains of developing rats by immunocytochemistry and electron microscopy. Moderately dense labelling was observed in the supraventricular corpus callosum in the 7- and 8-day-old rats, whilst very dense labelling was observed in the same region, in the 9- and 10-day-old rats. Very little immunoreactivity was observed at 14 days, and no staining was observed in the corpus callosum in adult rats. HNE staining was not observed in neuronal cell bodies that give rise to callosal axons in the overlying cerebral cortex. Electron microscopy showed dense HNE staining on the basal laminae of blood vessels and on the plasma membranes of unmyelinated axons. Large numbers of rounded cells with features of oligodendrocyte precursor cells were labelled by Perl's stain in the supraventricular corpus callosum at postnatal day 7 and postnatal day 10, i.e. at times corresponding to high levels of HNE immunoreactivity. In contrast, very few such cells were observed in the adult brain, corresponding to the very little or no Perl's staining in the adult. These results suggest that lipid peroxidation observed in the supraventricular corpus callosum at postnatal day 10 could result from an accumulation of iron in this region, at this time.

Aging↗

Cloning, molecular characterization, and application of rice epiphytic Bacillus pumilus promoter fragments.

To establish a constitutive, high-efficiency expression system for Bacillus pumilus (B.P), we cloned random chromosomal DNA into promoter probe shuttle vector ECE7 and selected for strong promoter activity by chloramphenicol resistance of transformed B. pumilus cells. The nucleotide sequences of nine chromosomal fragments were determined. These DNA fragments range from 300 to 2200 bp in size. The transcription strength of these promoters was estimated by determination of CAT enzyme production in both E. coli and B. pumilus. Transcription start (TS) sites of the cat mRNA were located by primer extension by using total RNA. Preliminary analysis showed that three of the promoter sequences contain -35 and -10 regions like E. coli RNA polymerase sigma70 and B. subtilis sigma43 consensus sequences. One is similar to B. subtilis sigma29, the other two have no conserved sequences like any of the typical consensus sequences of the known sigma factors so far. To estimate the feasibility of the utilization of these promoters, one promoter fragment was subcloned and used to drive the expression of green fluorescent protein (GFP) in B. pumilus cells. This is the first report of B. pumilus promoters randomly cloning from total DNA and molecular analysis of their consensus sequences.

Bacillus↗

Suppression of tumorigenicity in human ovarian carcinoma cell line SKOV-3 by microcell-mediated transfer of chromosome 11.

To determine the pathogenic role of chromosomes 11 and 17 in the carcinogenesis of human ovarian cancers, neo(R)-tagged chromosome 11 or 17 was transferred from cell lines A9H11 or A9H17, respectively, into the ovarian carcinoma cell line SKOV-3 using microcell-mediated chromosome transfer. The chromosome transfer was verified by polymerase chain reaction detection of the neo(R) gene, fluorescence in situ hybridization detection of an extra chromosome 11, and microsatellite polymorphism detection of an exogeneous chromosome 11. Five SKOV-3/A9H11 hybrids and five SKOV-3/A9H17 hybrid clones were generated. For the chromosome 11 transfer, complete suppression of tumorigenicity was observed in four clones, (11)9-8 and 11(H)7-2, 11(H)8-3, and 11(H)7-2, 100 days post implantation. For the chromosome 17 transfer, no complete suppression of tumorigenicity was observed. However, an increased latency period ranging from 25 to 49 days in contrast to 7 days for the SKOV-3 parental line, and a significant reduction in tumor size was observed. There was no correlation between the in vitro growth rate and the tumorigenicity or length of latency period. Our results demonstrate functionally that chromosome 11 may carry a tumor suppressor gene(s) while chromosome 17 may carry a tumor growth-inhibitor gene(s) for the ovarian carcinoma cell line, SKOV-3.

Animals↗

Host pathogenesis in urinary tract infections.

Urinary tract infections (UTIs) are the result of an interaction between bacterial virulence and host defense factors that compete to invade or protect the host, respectively. Research over the past 30 years has demonstrated that vaginal colonization with uropathogens precedes most UTIs. Receptivity of the vaginal mucosa for uropathogens is an essential initial step in vaginal mucosa colonization. When vaginal and buccal epithelial cells were collected from patients susceptible to reinfection and compared with such cells obtained from controls resistant to UTIs, the strains that caused cystitis adhered much more avidly to the epithelial cells from susceptible women. These genotypic traits for epithelial cell receptivity may be a major susceptibility factor in UTIs. The presence or absence of blood group determinants on the surface of uroepithelial cells may influence an individual's susceptibility to UTIs. The protective effect in women with the secretor phenotype may be due to fucosylated structures at the cell surface which decrease the availability of putative receptors for Escherichia coli. Susceptibility among women who do not secrete blood group antigens may be due to specific E. coli-binding glycolipids that are absent in women who secrete blood group antigens. Recent studies have shown that the vaginal fluid, which forms an interface between uropathogens and epithelial cells, also influences vaginal colonizations.

Bacterial Adhesion↗

Molecular cytogenetic characterization and clinical relevance of additional, complex and/or variant chromosome abnormalities in acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL) is characterized by typical morphological manifestation, t(15;17) translocation and active response to all-trans retinoic acid (ATRA) in the great majority of patients. However, a subset of APL cases may present atypical phenotypic, cytogenetic or molecular features at different stages of the disease. The biological and clinical significance of these features sometimes remains obscure. In this study, 284 APL patients were cytogenetically analyzed and precise diagnosis was performed according to the molecular cytogenetic results. Twenty-six APL patients were identified as having additional, complex and/or variant chromosomal abnormalities at diagnosis or at relapse, 16 of them being further analyzed using fluorescence in situ hybridization (FISH) or chromosome painting (CP). Interestingly, some of these chromosomal aberrations were found to be associated with atypical morphology and/or drug response, indicating a genotype-phenotype correlation. Analysis of the complex karyotype may also allow a better understanding of the levels of cellular origin of the leukemogenesis. Examination of the remission induction and survival data showed that the presence of the additional/complex chromosome abnormalities was related to the prognosis in both primarily diagnosed and relapsed patients in this series.

Adolescent↗

Feasibility and clinical significance of real-time quantitative RT-PCR assay of PML-RARalpha fusion transcript in patients with acute promyelocytic leukemia.

INTRODUCTION: To study the relationship between the expression level of the PML-RARalpha fusion transcripts and the clinical status and efficiency of the therapy in acute promyelocytic leukemia (APL) patients, we applied a very sensitive and specific real-time Reverse Transcription Polymerase Chain Reaction (RT-PCR) system to quantify the dose of PML-RARalpha fusion transcripts in a series of APL patients at distinct disease stages. MATERIALS AND METHODS: A total of 31 APL patients (19 males and 12 females; aged from 8 to 74 years) from eight hospitals in Shanghai were analysed. Real-time Quantitative RT-PCR was used to measure the normalized dose (DoseN) of PML-RARalpha fusion transcripts. RESULTS: A wide range of PML-RARalpha DoseN above 1 x 10(3) was noted in 25 newly diagnosed patients. PML-RARalpha DoseN was significantly decreased after remission induction with ATRA, ATRA/chemotherapy or As2O3 and further reduced after consolidation. The fact that all patients with long disease free survival had a constantly low PML-RARalpha DoseN below 2 x 10(2) and a higher level predicted impending relapse suggests that this value could serve as a 'threshold' for molecular remission. PML-RARalpha DoseN was also of prognostic value in a group of relapsed patients, since good response to As2O3 reinduction was accompanied by a remarkable reduction of fusion transcript level, whereas patients with high PML-RARalpha Dose(N) after the second CR tended to relapse again rapidly. CONCLUSION: These results confirm that real-time RT-PCR assay for PML-RARalpha transcripts in APL patients is useful in reflecting leukemic burden, assessing response to treatment and indicating the ultimate clinical outcome or curability of disease.

Adolescent↗

Osteopontin gene is expressed in the dermal papilla of pelage follicles in a hair-cycle-dependent manner.

Hair follicle formation and maintenance involve intimate interactions between follicular epithelial cells and a group of specialized mesenchymal cells known as the dermal papilla. Using the random primer polymerase chain reaction, we have identified an approximately 1.4 kb osteopontin mRNA that is present in large quantities in cultured rat vibrissa dermal papilla cells but undetectable in cultured rat skin fibroblasts. In situ hybridization showed that the osteopontin gene is expressed in dermal papilla cells of pelage follicles during catagen but not in anagen or telogen. As an acidic glycosylated RGD-containing extracellular matrix protein, osteopontin can function both as a cell attachment protein and as a soluble cytokine playing roles in signaling, cell migration, tissue survival, anti-inflammation, and T-cell-mediated cellular immunity. Our results indicate that the comparison of the mRNA of cultured dermal papilla cells and fibroblasts can lead to the identification of not only anagen-specific genes (e.g., nexin 1), but also a catagen-specific gene. We have thus provided evidence that specific genes are turned on during catagen, which is therefore not simply a passive "degenerative" phase. The functional role of osteopontin in catagen is unclear but it may promote the formation of a tightly aggregated dermal papilla, and/or protect the dermal papilla cells from apoptosis induced by cytokines or hypoxia during catagen.

Alopecia↗