Biomedical subjects

Li Cao

Publications and source records attributed to Li Cao.

At least 37 records · Page 2Linked to original sources

PubMed2006

[Influence of high- and low-osmolality contrast media on renal function in children].

OBJECTIVE: To compare the effects of different contrast media on the renal function in children, and to investigate the prophylactic efficacy of hydration. METHODS: Sixty patients on whom either intravenous pyelography (IVP) or enhanced CT scan was required were divided into high osmolality contrast media (HOCM) group (n = 27) and low osmolality contrast media (LOCM) group (n = 33), and each group was randomly subdivided into hydration group (HG) and non-hydration group (NHG). In HOCM group, HG had 14 cases and NHG had 13 cases; while in LOCM group, HG had 18 cases and NHG had 15 cases. A 1/5-tonic solution at a dose of 20 ml/kg was intravenously given immediately after the exposure to a contrast medium within 3 hours in the HG, while the NHG cases were not given any infusion. RESULTS: There were no significant difference between HG and NHG in baseline serum creatinin (SCr) and creatinin clearance (Ccr). After exposure, in HOCM group, SCr of NHG (59.71 +/- 12.49) micromol/L significantly increased as compared with baseline (49.91 +/- 6.09) micromol/L (P < 0.05), while Ccr (97.81 +/- 15.10)ml/(min x 1.73 m(2)) decreased compared with baseline (71.33 +/- 7.51) ml/(min x 1.73 m(2)) (P < 0.05). No significant changes of SCr and Ccr were observed in the HG before (48.37 +/- 7.11) micromol/L, (99.81 +/- 15.41) ml/(min x 1.73 m(2)) and after (49.63 +/- 6.84) micromol/L, (88.29 +/- 12.75) ml/(min x 1.73 m(2)) (P > 0.05) the exposure to contrast medium. Contrast medium-associated nephropathy (CAN) was found in 3 cases in NHG (23.1%, 3/13) but none in HG (P > 0.05). In the LOCM group, there was no significant difference in SCr and Ccr before and after the exposure to the contrast media. The incidence of CAN was 6.7% (1/15) in the NHG and 11.1% (2/18) in the HG (P > 0.05). The average increase of SCr in HOCM group was significantly higher than that in LOCM group (Z = -2.42, P < 0.05). The average decrease of Ccr in HOCM group was significantly higher than that in LOCM group (Z = -2.83, P < 0.05). The SCr and Ccr of the 6 CAN cases in both HOCM and LOCM groups returned to baseline level within 2 weeks. CONCLUSIONS: (1) Children can develop reversible CAN after the exposure to high or low osmolality contrast medium. (2) The high osmolality contrast medium seemed to have more serious toxicity in renal function than low osmolality contrast medium. (3) The prophylactic use of hydration can effectively prevent CAN in patients who will expose to high osmolality contrast medium. (4) Children can develop reversible CAN after the exposure to low osmolality contrast medium even after hydration.

Child↗

PubMed2006

[A study on non-invasive indexes of atherosclerosis in obstructive sleep apnea-hypopnea syndrome patients].

OBJECTIVE: To investigate the relationship between obstructive sleep apnea-hypopnea syndrome (OSAHS) and atherosclerosis through determining flow-mediated dilation (FMD), pulse wave velocity (PWV) and carotid intima-media thickness (CIMT). METHODS: FMD, PWV and CIMT were measured in 76 OSAHS patients (68 men/8 women) and 76 control subjects matched for age, sex and body mass index. FMD, PWV and CIMT were compared between the two groups. In the OSAHS group, correlations were calculated between apnea-hypopnea index (AHI) and FMD, PWV and CIMT. RESULTS: Compared to the control group, the OSAHS group had significantly higher PWV [(1,720 +/- 247) cm/s vs (1,469 +/- 172) cm/s, P < 0.01] and CIMT [(1.10 +/- 0.34) mm vs (0.80 +/- 0.18) mm, P < 0.01], but significantly lower FMD [(5.8 +/- 1.7)% vs (8.9 +/- 1.4)%, P < 0.01]. When patients with hypertension from the two groups were compared, PWV [(1,850 +/- 244) cm/s vs (1,655 +/- 161) cm/s, P = 0.001] and CIMT [(1.24 +/- 0.35) mm vs (0.99 +/- 0.18) mm, P = 0.003] were significantly higher, and FMD [(5.2 +/- 1.7)% vs (7.5 +/- 1.1)%, P < 0.01] was significantly lower in the OSAHS group (n = 43) than in the control group (n = 21). In the OSAHS group, AHI was correlated positively with PWV and CIMT (r = 0.883, 0.698, all P < 0.01), but negatively with FMD (r = -0.711, P < 0.01). CONCLUSION: Vascular endothelial dysfunction and atherosclerosis are present in OSAHS patients, and related to the severity of OSAHS.

Aged↗

PubMed2006

[16S rDNA-RFLP analysis of structure and diversity of an aerobic microbial community degrading hexachlorobenzene].

Hexachlorobenzene is a chlorinated aromatic hydrocarbon that was widely used as a seed dressing for prevention of fungal growth on crops, and is also a component of fireworks, ammunition, and synthetic rubbers. Because of the bioaccumulation and persistence of hexachlorobenzene as well as its potential toxicity, hexachlorobenzene must be removed from environment. The potential for aerobic dechlorination of hexachlorobenzene by a hexachlorobenzene-adapted mixed culture was investigated. An aerobic microbial community which was able to grow at the presence of hexachlorobenzene was enriched from sediment from contaminated site after incubating about 2 months. During the growth of the mixed microorganisms on hexachlorobenzene, the accumulating consumption of oxygen, the microbial population curve and the release of Cl- were investigated. The data suggest the rapid degradation of hexachlorobenzene to support microbial growth and the aerobic decholrination of hexachlorobenzene was observed. The result showed that the mixed microorganisms were able to utilize hexachlorobenzene as sole carbon and energy source. It was shown that up to 55% of HCB could be degraded during 18 days incubation at 30 degrees C in mineral salts medium (pH 7.0) with 4.5mg/L HCB. The calculated rate of hexachlorobenzene biodegradation was 137.5 microg/ (L x d). The 16S rDNA genes were amplified from community DNA by using primers specific to bacteria and were subsequently cloned. The cloned 16S rDNA fragments were reamplified, and restriction analysis was performed following separate digestion with enzymes Hae III and Rsa I. Application of restriction fragment length polymorphism screening approach revealed 9 clusters, and 3 major clusters were sequenced. Nearly complete 16S rDNA sequence analysis show that the microbial community was dominated by Alcaligenes and Azospirillum groups. This is the first report describing aerobic dechlorination of hexachlorobenzene via dehalorespiration by a microbial community which was enriched from contaminated site. The microbial community can be used to degrade highly recalcitrant chlorinated pollutants.

Bacteria, Aerobic↗

PubMed2005

Localization of PSORS1 to a haplotype block harboring HLA-C and distinct from corneodesmosin and HCR.

Psoriasis is a complex inflammatory disease of the skin affecting 1-2% of the Caucasian population. Associations with alleles from the HLA class I region (now known as PSORS1), particularly HLA-Cw*0602, were described over 20 years ago. However, extensive linkage disequilibrium (LD) within this region has made it difficult to identify the true susceptibility allele from this region. A variety of genes and regions from a 238-kb interval extending from HLA-B to corneodesmosin (CDSN) have been proposed to harbor PSORS1. In order to identify the minimum block of LD in the MHC class I region associated with psoriasis we performed a comprehensive case/control and family-based association study on 242 Northern European psoriasis families and two separate European control populations. High resolution HLA typing of HLA-A, -B and -C alleles was performed, in addition to the genotyping of 18 polymorphic microsatellites and 36 SNPs from a 772-kb segment of the HLA class I region harboring the previously described interval. This corresponded on average to one SNP every 7 kb in the candidate 238 kb region. With all tests, the association was the strongest with single markers and haplotypes from a block of LD harboring HLA-C and SNP n.9. Logistic regression analyses indicated that association seen with candidate genes from the interval such as CDSN and HCR was entirely dependent on association with HLA-Cw*0602 and SNP n.9-G alleles. The previously reported association with CDSN and HCR was observed to be due to the existence of the associated alleles lying on the most commonly over-transmitted haplotype. Rare over-transmitted haplotypes also harbored HLA-Cw*12 alleles. HLA-Cw*12 family members are closely related to HLA Cw*0602, sharing identical sequences in their alpha-2 domains, peptide-binding pockets A, D and E and all 3' introns. The introduction of a potential binding site for the RUNX/AML family of transcription factors in intron 7, is also specific to these HLA-C alleles. These variants need to be investigated further for their role as PSORS1.

Case-Control Studies↗

PubMed2005

Purification of novel UBAP1 protein and its decreased expression on nasopharyngeal carcinoma tissue microarray.

Recently, the UBAPl gene, a putative nasopharyngeal carcinoma (NPC) related gene, which is located at human chromosome 9p21-22 where loss of heterozygosity frequently occurs in NPC, was cloned. The present study aimed to explore the purification approach to UBAP1 protein and its expression pattern in NPC with tissue microarray. The full length coding sequence of UBAP1 was subcloned into a prokaryotic expression vector, pGEX-4T-2, and expressed in Escherichia coli as a GST-fusion protein. With modification of the purification method, GST-UBAP1 fusion protein achieved a high level of purity. The New Zealand rabbit was immunized with the purified fusion protein to prepare polyclonal antiserum following standard protocols. With this antiserum, high-throughput analysis of UBAP1 protein expression using immunohistochemistry was performed on self-made tissue microarrays consisting of 316 nasopharyngeal specimens from 148 NPC and 168 non-cancerous nasopharyngeal epithelia with different morphological features. Consequently, we found that there was a significant decrease in the percentage of positive expression in all NPC on protein levels for UBAP1 (23%), compared to that of the non-NPC (89%) (P<0.01). The result suggests that UBAP1 might be a potential effective diagnosis candidate for NPC and decreased expression of UBAP1 protein is a possible point of dysfunction along the pathogenesis pathway for NPC that may contribute to malignant transformation.

Animals↗

PubMed2005

A new route to zinc-blende CdSe nanocrystals: mechanism and synthesis.

We report the possible mechanism of forming of CdSe nanocrystals in the high boiling point solvents with long alkane chains and a novel Non-TOP-Based route to zinc-blende CdSe nanocrystals. A new mechanism shows that there exits a redox reaction in the long alkane chain solvents: Se is reduced to H2Se gas; at the same time, the long alkane chains are oxidated to alkene chains; then, the Cd complex reacts with H2Se to form CdSe nanocrystals. Possible chemical reaction equations involved in the process of forming the CdSe nanocrystals have been discussed. The alkene chain and H2Se were detected respectively by a series of experiments to support the new mechanism. Under the guidance of this mechanism, we have developed a much cheaper and greener Non-TOP-Based route for the synthesis of a size series of high-quality zinc-blende (cubic) CdSe nanocrystals. Low-cost, green, and environmentally friendlier reagents are used, without use of expensive solvents such as trioctylphosphine (TOP) or tributylphosphine (TBP). The new route enables us to achieve high-quality CdSe nanocrystals with sharp ultraviolet and visible (UV-vis) absorption peaks, controllable size (2.0-5.0 nm), bright photoluminescence (PL), narrow PL full width of half-maximum (fwhm) (29-48 nm), and high PL quantum yield (up to 60%) without any size sorting.

Cadmium↗

PubMed2005

Exciton interactions in CdS nanocrystal aggregates in reverse micelle.

Here we report the formation and spectroscopic properties of cadmium sulfide (CdS) nanocrystal systems: individual nanocrystal and CdS aggregates. The optical absorption and luminescence spectra of the aggregated CdS nanocrystals and individual nanocrystal show exciton aggregate and individual exciton characteristics. Although it is not Bose-Einstein condensation, such aggregated quantum dots (QDs) seem to supply us opportunity to study the interactions and condensation of excitons in multi-QDs system, not in the separated QDs system.

Journal Article↗

PubMed2005

Expression and functional characterization of LRRC4, a novel brain-specific member of the LRR superfamily.

LRRC4, a novel member of LRR superfamily thought to be involved in development and tumorigenesis of the nervous tissue, has the potential to suppress tumorigenesis and cell proliferation of U251MG cells. This study aimed at revealing the correlation between expression of LRRC4 and the maintenance of normal function and tumorigenesis suppression within the central nervous system. We systematically analyzed the expression and tissue distributions of the gene in tissues. Results showed that LRRC4 expression was limited to normal adult brain, both in human and in mouse, and exhibited a development-regulated pattern, but was down-regulated in brain tumor tissues and U251MG cell line. Furthermore, dynamic alterations in gene expression associated with cell cycle progression were investigated by using Tet-on system. Results showed that LRRC4 induced a cell cycle delay at the late G1 phase, probably through the alteration of the expression of different cell cycle regulating proteins responsible for mediating G1-S progression, such as p21(Waf1/Cip1) and p27(Kip1), Cdk2 and PCNA, p-ERK1/2. These findings suggest that LRRC4 may play an important role in maintaining normal function and suppressing tumorigenesis in the central nervous system.

Animals↗

PubMed2005

[Mutation analysis of PINK1 gene in Chinese patients with autosomal recessive early-onset parkinsonism type 6].

OBJECTIVE: To detect PINK1 gene mutations and study the clinical features in Chinese patients with autosomal recessive early-onset parkinsonism (AREP) type 6. METHODS: PINK1 gene mutations were detected using polymerase chain reaction (PCR), DNA sequence analysis, and restriction enzyme digestion analysis in 11 index probands of 11 AREP families. RESULTS: Two novel point mutations in PINK1 gene, C938T in exon four, leading to substitution of a threonine for methionine codon at amino acid 313 (T313M) and C1474T in exon seven introducing a stop codon at amino acid 492 (R492Stop), were found in two families. In another family, a synonymous mutation (Y454Y) was detected. The clinical features in patients with PINK1 mutations included early onset, slow disease progression, hyperreflexia, diurnal fluctuations with sleep benefit, and good response to levodopa. However, dyskinesias related to levodopa treatment were absent. CONCLUSION: PINK1 gene mutations are a common cause of AREP. PARK6 pedigrees have been firstly identified in Chinese Mainland. Clinical heterogeneity exists in PARK6.

Adolescent↗

PubMed2005

[One-stage radical eradication and wedged vertebral osteotomy through a purely posterior procedure in treating thoracic and lumbar spine tuberculosis associated with kyphosis or scoliokyphosis demormity].

OBJECTIVE: To investigate the feasibility, clinical indications and significance of one-stage radical eradication, wedged vertebral osteotomy and instrumentation in the treatment of tuberculosis of thoracic and lumbar spine associated with kyphosis or scoliokyphosis through a purely posterior procedure. METHODS: Sixteen cases with tuberculosis of thoracic and lumbar spine associated with kyphosis or scoliokyphosis were treated by one-stage radical eradication, wedged vertebral osteotomy and instrumentation fixation through posterior procedure. All patients included 12 males and 4 females, and the average age was 37.1 years (from 17 to 53 years). The preoperative average Cobb angle of kyphosis was 78.3 degrees (range from 54 degrees to 138 degrees ). There were 2 cases associated with scoliosis (the Cobb angle of scoliosis was 31 degrees and 24 degrees), and 1 case with lateral transition. Spinal cord compression were found in 7 cases. According to the Frankel's classification, 2 cases belonged to C degree, and 5 cases to D degree. There were 2 cases with caudal equina or nerve root lesions. RESULTS: The average blood loss during the operation was 1100 ml (range from 450 to 2200 ml), and the average operation time was 265 min (range from 215 to 325 min). The postoperative results were satisfactory, 14 cases were excellent and 2 cases were good. Obvious improvement was obtained in 9 cases with neurological dysfunction. The postoperative average Cobb' angle was 28.5 degrees (range from 0 degrees to 67 degrees), and the corrective rate was 63.6%. The followed-up was ranged from 14 to 52 months with an average of 26.3 months. There were no major complications related to the fixations, loss of correction and the fusion were achieved in all patients. CONCLUSIONS: One-stage radical eradication, wedged vertebral osteotomy and instrumentation is a feasible and an effective procedure in the treatment of spinal tuberculosis associated with kyphosis or scoliokyphosis. Compared with combined anterior and posterior procedure, the surgical technique may decrease injuries and has better result.

Adolescent↗

PubMed2005

Study of a novel brain relatively specific gene LRRC4 involved in glioma tumorigenesis suppression using the Tet-on system.

LRRC4 is a novel relatively specific gene, which displays significant down-regulation in primary brain tumor biopsies and has the potential to suppress brain tumor growth. In this study, we investigated the growth inhibitory effect of LRRC4 on tumorigencity in vivo and on cell proliferation in vitro by a tetracycline-inducible expression system. Results showed that LRRC4 significantly reduced the growth and malignant grade of xenografts arising from glioblastoma U251MG cells. Cell proliferation was markedly inhibited after U251MG Tet-on-LRRC4 cell induction with doxycycline. Flow cytometry and Western blot analysis demonstrated that LRRC4 mediated a delay of the cell cycle in late G1, possibly through up-regulating the expressions of p21Waf1/cip1 and p27Kip1 and down-regulating the expressions of cyclin-dependent kinase 2, retinoblastoma protein and epidermal growth factor receptors. Together, these findings provide clues to the function of LRRC4 as a negative regulator of cell growth and underscore a link between the above-mentioned cyclins, cyclin-associated molecules and tumorigenicity.

Animals↗

PubMed2005

Profiling of differentially expressed genes in LRRC4 overexpressed glioblastoma cells by cDNA array.

Our previous study has shown that LRRC4 is a novel member of the leucine-rich repeat (LRR) superfamily and has the potential to suppress brain tumor growth. In order to further analyze the functions of LRRC4 on the maintenance of normal function and suppression of tumorigenesis in the central nervous system, we investigated alterations in gene expression related to neurobiology by the Atlas array in two inducible dual-stable LRRC4-overexpressing cell lines. Seventeen of 588 genes spotted on the Atlas membrane showed altered expression levels in LRRC4 transfected U251MG Tet-on cells, which are involved in cell proliferation and cell cycle progression, tumor invasion and metastasis, and neurotransmitter synthesis and release. In addition, cell invasion assay results showed that LRRC4 can inhibit the U251MG cell migration. These studies represent the first cDNA array analysis of the effects of LRRC4 on the involvement of different neurobiological genes in U251MG glioblastoma cells and provide new insights into the function of LRRC4 in glioma.

Blotting, Western↗

PubMed2005

Protein engineering of epoxide hydrolase from Agrobacterium radiobacter AD1 for enhanced activity and enantioselective production of (R)-1-phenylethane-1,2-diol.

DNA shuffling and saturation mutagenesis of positions F108, L190, I219, D235, and C248 were used to generate variants of the epoxide hydrolase of Agrobacterium radiobacter AD1 (EchA) with enhanced enantioselectivity and activity for styrene oxide and enhanced activity for 1,2-epoxyhexane and epoxypropane. EchA variant I219F has more than fivefold-enhanced enantioselectivity toward racemic styrene oxide, with the enantiomeric ratio value (E value) for the production of (R)-1-phenylethane-1,2-diol increased from 17 for the wild-type enzyme to 91, as well as twofold-improved activity for the production of (R)-1-phenylethane-1,2-diol (1.96 +/- 0.09 versus 1.04 +/- 0.07 micromol/min/mg for wild-type EchA). Computer modeling indicated that this mutation significantly alters (R)-styrene oxide binding in the active site. Another three variants from EchA active-site engineering, F108L/C248I, I219L/C248I, and F108L/I219L/C248I, also exhibited improved enantioselectivity toward racemic styrene oxide in favor of production of the corresponding diol in the (R) configuration (twofold enhancement in their E values). Variant F108L/I219L/C248I also demonstrated 10-fold- and 2-fold-increased activity on 5 mM epoxypropane (24 +/- 2 versus 2.4 +/- 0.3 micromol/min/mg for the wild-type enzyme) and 5 mM 1,2-epoxyhexane (5.2 +/- 0.5 versus 2.6 +/- 0.0 micromol/min/mg for the wild-type enzyme). Both variants L190F (isolated from a DNA shuffling library) and L190Y (created from subsequent saturation mutagenesis) showed significantly enhanced activity for racemic styrene oxide hydrolysis, with 4.8-fold (8.6 +/- 0.3 versus 1.8 +/- 0.2 micromol/min/mg for the wild-type enzyme) and 2.7-fold (4.8 +/- 0.8 versus 1.8 +/- 0.2 micromol/min/mg for the wild-type enzyme) improvements, respectively. L190Y also hydrolyzed 1,2-epoxyhexane 2.5 times faster than the wild-type enzyme.

DNA Shuffling↗

PubMed2005

The Tetratricopeptide repeat domain 7 gene is mutated in flaky skin mice: a model for psoriasis, autoimmunity, and anemia.

The flaky skin (fsn) mutation in mice causes pleiotropic abnormalities including psoriasiform dermatitis, anemia, hyper-IgE, and anti-dsDNA autoantibodies resembling those detected in systemic lupus erythematosus. The fsn mutation was mapped to an interval of 3.9 kb on chromosome 17 between D17Mit130 and D17Mit162. Resequencing of known and predicted exons and regulatory sequences from this region in fsn/fsn and wild-type mice indicated that the mutation is due to the insertion of an endogenous retrovirus (early transposon class) into intron 14 of the Tetratricopeptide repeat (TPR) domain 7 (Ttc7) gene. The insertion leads to reduced levels of wild-type Ttc7 transcripts in fsn mice and the insertion of an additional exon derived from the retrovirus into the majority of Ttc7 mRNAs. This disrupts one of the TPRs within TTC7 and may affect its interaction with an as-yet unidentified protein partner. The Ttc7 is expressed in multiple types of tissue including skin, kidney, spleen, and thymus, but is most abundant in germinal center B cells and hematopoietic stem cells, suggesting an important role in the development of immune system cells. Its role in immunologic and hematologic disorders should be further investigated.

Amino Acid Sequence↗

PubMed2005

[Neuroprotection by resveratrol against cytotoxicity of oxidized low density lipoprotein in PC12 cells].

OBJECTIVE: To investigate neuroprotection of resveratrol against cytotoxicity of oxidized low density lipoprotein (oxLDL) in PC12 cells. METHODS: PC12 cells were pretreated with resveratrol for one hour as a neuron model and then exposed to oxLDL at varied concentrations. Effects of resveratrol on cell viability, permeability of cell membrane, cell nucleus and activity of caspase-3 were evaluated with MTT assay, lactic acid dehydrogenase (LDH) release assay, DNA fragmentation (TUNEL) assay and assay for caspase-3 activity (caspase assay). RESULTS: Cell viability, LDH release rate, percentage of cells with positive TUNEL and activity of caspase-3 were (62 +/- 3)%, (23 +/- 3)%, (26 +/- 5)% and (0.811 +/- 0.049) mol.min(-1).microg(-1), vs (84 +/- 7)%, (13 +/- 4)%, (12 +/- 4)% and (0.553 +/- 0.048) mol.min(-1).microg(-1) in PC12 cells treated with 10 mg/L oxLDL vs in those treated with 10 mg/L oxLDL plus 50 micromol/L resveratrol, respectively, with statistically significant difference. CONCLUSION: Resveratrol could attenuate cytotoxicity induced by oxLDL in PC12 cells with neuroprotection.

Animals↗

PubMed2005

[Effect of hepatocyte growth factor on oxygen-glucose deprived injury of astrocytes].

OBJECTIVE: To explore the effect of hepatocyte growth factor (HGF) on oxygen-glucose deprived injury and apoptosis of astrocytes. METHODS: The injury of primary cultured rat cerebral cortical astrocytes was induced by oxygen-glucose deprivation. Astrocytes were treated with HGF at various final concentrations of 20 - 100 ng/mL. The cell damage and viability were evaluated by the lactate dehydrogenase (LDH) released rate and the 3- (4,5-dimethylthazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) conversion method. Detection of apoptotic cells was determined by the flow cytometry, and the ultrastructure was observed by the transmission electron microscope. RESULTS: Oxygen-glucose deprivation increased the LDH release rate, decreased the cell viability and increased the number of apoptotic astrocytes. While exposed to HGF at the same condition, the LDH release rate decreased, the cell viability increased, and the percentage of apoptotic cells decreased (P <0.05). The maximum protective effect of HGF was observed at 60 ng/mL. CONCLUSION: HGF can protect cultured astrocytes from oxygen-glucose deprived injury, and attenuate the apoptosis of astrocytes in a dose-dependent manner.

Animals↗

PubMed2005

[Function of a novel brain-specific gene LRRC4].

OBJECTIVE: To study the suppressive effect of LRRC4 gene on human glioma U251 cells and further investigate its biological functions. METHODS: H&E, DNA and AgNORs stainings were performed on LRRC4-transfected U251 cells, mock-transfected U251 cells and non-transfected U251 cells, respectively. Quantitative analysis including cell morphometry, DNA content, DNA ploidy, silver stained argyrophilic nucleolar organizer regions (AgNORs) were investigated by image analysis. Flow cytometry was employed to determine the difference of cell cycle distribution and MTT staining was used to elucidate the activity of the LRRC4-transfected U251 cells. RESULTS: The morphological cell parameters such as area, perimeter and diameter, DNA content, chromosomal aneupoloidy, mean area of AgNORs particles and mean nucleus area of the LRRC4-transfected U251 cells were remarkably decreased compared to those of the mock-transfected and non-transfected U251 cells (P < 0.05, P < 0.01). Meanwhile, significant accumulation of cells in G(0)/G(1) phase but decrease of cells in S and G(2)/M phase, was observed in transfected U251 cells compared to those of the mock-transfected and non-transfected U251 cells (P < 0.05, P < 0.01). MTT staining showed that proliferation activity of both the mock- and non-trasfected U251 cells was significantly higher than that of the U251 cells transfected with LRRC4 gene (P < 0.01). CONCLUSION: LRRC4 gene might be involved in tumor suppression by restraining DNA synthesis and the nucleoli organizer regions-associated proteins, keeping the cell cycles in phase G(0)/G(1) and reducing proliferation activity of the glioma cells. Morphometry combined with other techniques such as flow cytometry and MTT staining can well elucidate the biological function of novel genes.

Brain Neoplasms↗

PubMed2005

[Mutation analysis of DJ1 gene in patients with autosomal recessive early-onset Parkinsonism].

OBJECTIVE: To investigate the mutation characteristics of DJ1 gene in Chinese patients with autosomal recessive early-onset Parkinsonism (AR-EP). METHODS: Mutations of DJ1 gene were screened by polymerase chain reaction combined with DNA direct sequencing in index patients with AR-EP from 11 unrelated families. RESULTS: No pathogenetic mutations in the DJ1 gene were detected in this group. Six intronic DJ1 polymorphisms (IVS1-15T-->C, IVS4+30T-->G, IVS4+45G-->A, IVS4+46G-->A, IVS5+31G-->A, g.168-185del) were found. Three of them (IVS1-15T-->C, IVS4+45G-->A, IVS4+46G-->A) were not reported previously. CONCLUSION: DJ1 mutations were rare in Chinese patients with autosomal recessive early-onset Parkinsonism.

Adolescent↗