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Biomedical subjects

Q Cai

Publications and source records attributed to Q Cai.

At least 19 recordsLinked to original sources
PubMed2006

CYP19A1 genetic polymorphisms may be associated with obesity-related phenotypes in Chinese women.

OBJECTIVE: To examine the relationship between genetic polymorphisms of the CYP19A1 gene and obesity-related phenotypes, body mass index (BMI) and waist-to-hip ratio (WHR). SUBJECTS: In total, 1241 Chinese women, who were recruited as community controls for a population-based case-control study of breast cancer. METHODS: Nineteen haplotype tagging single nucleotide polymorphisms (htSNPs) in four haplotype blocks were genotyped. RESULTS: Significant associations were observed for WHR at three SNPs that are located in haplotype block 1, including rs2445765, rs1004984 and rs1902584 (P=0.05, 0.04 and 0.01, respectively). Women, particularly premenopausal women, who carried the minor allele at any of these SNPs, had higher WHR than those without it. Of these three SNPs, the strongest association was observed at rs1902584, which is the closest to Promoter I.4, the major promoter for adipose tissue. Haplotype analyses indicated an association between the haplotype TCCAT in block 1 and WHR with a P-value of 0.02. CONCLUSION: These results suggested that CYP19A1 genetic polymorphisms may be associated with the risk of obesity among Chinese women, especially among premenopausal women. The CYP19A1 protein (aromatase) plays a critical role in estrogen biosynthesis and thus affects body fat distribution and regulation.

Adult↗
PubMed2006

Intrathecal sensory neuron-specific receptor agonists bovine adrenal medulla 8-22 and (Tyr6)-gamma2-MSH-6-12 inhibit formalin-evoked nociception and neuronal Fos-like immunoreactivity in the spinal cord of the rat.

The finding that sensory neuron-specific G-protein-coupled receptor mRNA is solely expressed in small primary sensory neurons suggests involvement of the receptor in nociceptive modulation. The present study was designed to assess effects of intrathecal administration of bovine adrenal medulla 8-22 and (Tyr6)-gamma2-MSH-6-12, selective sensory neuron-specific receptor agonists, on nocifensive behaviors and expression of spinal c-Fos-like immunoreactivity evoked by intraplantar injection of 2.5% formalin in rats. The agonists were administered 10 min before (pretreatment) and/or after (post-treatment) injection of formalin. Pretreatment with bovine adrenal medulla 8-22 dose-dependently (3, 10 and 30 nmol) decreased time lifting and licking the paw mainly in the second phase. Intrathecal bovine adrenal medulla 8-22 (30 nmol) remarkably suppressed nocifensive behaviors in the first and second phases and the expression of formalin-evoked c-Fos-like immunoreactivity in laminae I-II and V-VI of the spinal dorsal horn at L4-5. Moreover, naloxone (20 microg, intrathecal) failed to antagonize the inhibitory effects of bovine adrenal medulla 8-22. Post-treatment with bovine adrenal medulla 8-22 also exerted inhibition on the second phase behaviors in a dose-dependent manner with a similar efficacy observed in pretreatment groups. Furthermore, post-treatment with (Tyr6)-gamma2-MSH-6-12 (0.5, 1.5 and 5 nmol) also suppressed formalin-evoked nocifensive behaviors in the second phase and c-Fos-like immunoreactivity in the spinal dorsal horn similar with bovine adrenal medulla 8-22. Our results suggest that sensory neuron-specific receptor may play an important role in modulation of spinal nociceptive transmission. This is the first to demonstrate that activation of sensory neuron-specific receptor produces analgesia in the persistent pain model.

Animals↗
PubMed2006

Plasminogen activator inhibitor-1 promoter polymorphism is not associated with the aggressiveness of disease in prostate cancer.

AIMS: PAI-1 (plasminogen activator inhibitors-1) regulates plasminogen activation, and is related to tumour development. This study aims to test whether the promoter polymorphism in the PAI-1 gene is related to the aggressiveness of disease in prostate cancer. MATERIALS AND METHODS: In the present study, Taqman SNP genotyping assay was used to detect PAI-1 4G/5G polymorphism in DNA from paraffin-embedded tissues of 98 Caucasian patients with prostate cancer. RESULTS: The distribution of the genotypes is in Hardy-Weinberg equilibrium. The genotype had no statistically significant relationship with other prognostic factors. Similar risks for recurrence were seen in individuals with the 4G/4G and 4G/5G genotypes compared to those with 5G/5G genotype (odds ratio [OR] 2.65, 95% CI: 0.41-16.94, P = 0.30; OR = 2.19, 95% CI: 0.38-12.49, P = 0.38). CONCLUSION: We concluded that PAI-1 promoter polymorphism is not associated with the aggressiveness of disease in prostate cancer.

Aged↗
PubMed2006

Endoscopic retrograde cholangiopancreatography after a liquid fatty meal: effect on deep common bile duct cannulation time.

BACKGROUND AND STUDY AIM: Endoscopic retrograde cholangiopancreatography (ERCP) is an important gastrointestinal endoscopic procedure in the study and treatment of pancreaticobiliary diseases. The critical step of the procedure is cannulation of the common bile duct (CBD) and/or the pancreatic duct. Cannulation can be a technical challenge at times. Fat is a natural stimulator for bile secretion and relaxation of the sphincter of Oddi. The objective of this study was to determine the effect of a liquid fatty meal on deep CBD cannulation during ERCP. PATIENTS AND METHODS: We performed a randomized double-blind study in 84 patients to examine the effect of a liquid fatty meal on deep CBD cannulation during ERCP, in a teaching medical center. In the study group, each patient had a liquid fatty meal orally about 1 hour before the procedure. In the control group, each patient had the same volume of a non-fat meal. The appearance of the major papilla, the cannulation rate, the cannulation time, and the fluoroscopy time during cannulation were compared for the two groups. RESULTS: The orifice of the CBD/pancreatic duct was much more easily identified in the group who ingested the fatty meal. Compared with the non-fat meal group, in the fatty meal group the mean and the median deep CBD cannulation times were shorter, at 8.0 minutes vs. 14.7 minutes ( P = 0.005) and 8.0 minutes vs. 11.5 minutes ( P = 0.008), respectively. Additionally, in the fatty meal group, the mean and the median fluoroscopy times during deep CBD cannulation were lower, at 3.3 minutes vs. 6.1 minutes ( P = 0.040) and 2.5 minutes vs. 3.9 minutes ( P = 0.013), respectively. There were no complications, such as aspiration, associated with the liquid meals given shortly before the ERCP procedure. CONCLUSIONS: To avoid prolonged cannulation and unnecessary radiation exposure, patients should have a liquid fatty meal before ERCP procedures.

Catheterization↗
PubMed2006

Effects of a single nucleotide polymorphism on the expression of human tumor necrosis factor-alpha.

Tumor necrosis factor (TNF)-alpha plays a prominent role in inflammations and is a proinflammatory cytokine that has been implicated in the pathogenesis of autoimmune and infectious diseases. Recent association studies have found that the TNF-alpha-857T allele was associated with several disorders. Here we demonstrate, with reporter genes under the control of the two allelic TNF-alpha promoters, that the minor allele -857T is a much stronger transcriptional activator than the major allele -857C in RAW264.7 cell line in response to lipopolysaccharide stimulation. However, the result was not consistent in HeLa cell line. Furthermore, for the quantitative analysis of TNF-alpha synthesis between the -857C/C genotype from healthy subjects and the -857C/T genotype from AS patients, the quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay were performed separately. There was no significant difference between the two groups at the level of mRNA and protein. These results show that this polymorphism may have a direct effect on TNF-alpha regulation in a tissue-specific manner, and apart from the polymorphism at -857 in the TNF-alpha promoter, there may be other factors affecting the expression of TNF-alpha.

Adult↗
PubMed2001

[Effects of inorganic arsenicals on the methylation of p16 gene CpG islands and the expression of p16 gene in BEP2D cells].

OBJECTIVE: To study the effects of inorganic arsenicals on the methylation of p16 gene CpG islands and the expression of p16 gene in BEP2D cells. METHODS: The methylation of p16 gene CpG islands and the expression of p16 gene in BEP2D cells were measured by methylation-specific PCR (MSP) and RT-PCR methods. RESULTS: (1) The exposure of the BEP2D cells to sodium arsenite (0.016 approximately 2 micromol/L) or high-density sodium arsenate (80 approximately 160 micromol/L), but not low-density sodium arsenate (20 approximately 40 micromol/L), produced significant hypermethylation of p16 gene CpG islands in BEP2D cells. (2) The expressions of p16 gene in the groups of sodium arsenite and sodium arsenate at the test were lower than that of the control group, especially in the groups of sodium arsenite. CONCLUSIONS: Inorganic arsenicals alter the methylation patterns and the expression of p16 gene in BEP2D cells, which suggests that the hypermethylation of p16 gene CpG islands may be one of the mechanisms of carcinogenesis of inorganic arsenicals.

Arsenic↗
PubMed2001

Ultrafast formation of nonemissive species via intermolecular interaction in single crystals of conjugated molecules.

We investigate the influence of interchain interactions on the photoluminescence processes in a sexithiophene single crystal by applying hydrostatic pressure. We perform transient photoluminescence spectroscopy in the time domain of 100 fs for pressures up to 60 kbar. The combined use of steady-state and time-resolved optical spectroscopies allows us to show that the pressure-induced quenching of the photoluminescence is caused by an ultrafast (approximately 100 fs) formation of intermolecular species.

Journal Article↗
PubMed2001

Cloning and expression of the binary toxin gene from Bacillus sphaericus IAB872 in a crystal-minus Bacillus thuringiensis subsp. israelensis.

Bacillus sphaericus IAB872 has high toxicity against susceptible Culex spp. and medium larvicidal activity against binary toxin-resistant Culex spp. Sequence analysis revealed that the sequence of the binary toxin gene from IAB872 was totally identical to that of the reference strain 2362. The recombinant plasmids were introduced into an acrystalliferous B. thuringiensis strain 4Q7, and the resulting transformants produced parasporal inclusion composed of 51 kDa and 42 kDa proteins during sporulation. SDS-PAGE and Western blot further confirmed that B. thuringiensis transformants were able to express the binary toxin in a high level. Toxicity bioassays showed that they performed high toxicity to susceptible Culex spp. larvae, but no toxicity to resistant Culex larvae. It was, therefore, suggested that other unknown toxins perhaps existed in the wild strain IAB872 except the binary toxin. Their modes of action might be different from that of binary toxin, and they were possibly responsible for the activity of the wild strain IAB872 against resistant mosquito larvae.

Animals↗
PubMed2001

Determination of sulfur dioxide in vitriol plant wastewater by using a polyNiMe4TAA electrochemically modified Pt microelectrode.

A Pt microelectrode modified with nickel(II) polytetramethyldibenzo[b,i]tetraaza[14]annulene was prepared by electropolymerization of nickel(II) tetramethyldibenzo[b,i]tetraaza[14]annulene monomers and applied to determine sulfur dioxide in vitriol plant wastewater. For determination of SO2 with this electrochemically modified Pt microelectrode, the linear range was from 9.6 x 10(-6) to 2.4 x 10(-4) mol L-1, the sensitivity was 1.8 x 10(-4) A L mol-1, the detection limit was calculated to be 4.8 x 10(-6) mol L-1 (S/N = 3), the response time was less than 20 s and the relative standard deviation was found to be 2.1% on analyzing 4.8 x 10(-5) mol L-1 SO2 solution repeatedly (n = 7). These results demonstrated good accuracy compared with those obtained by the conventional iodimetric method.

Chemical Industry↗
PubMed2001

Preparation of microporous aluminium anodic oxide film modified Pt nano array electrode and application in direct measurement of nitric oxide release from myocardial cells.

A novel method for fabricating a nano array electrode (NAE) by using micropores of aluminium anodic film as templates was investigated. To evaluate the NAE, cyclic scanning of NAE in Fe(CN)6(3-) solution was performed and a sigmoidal shaped voltammogram was obtained. The NAE was designed to measure nitric oxide (NO) in vitro and in vivo. Studies showed that it was a sensitive and selective NO electrochemical sensor. NO release from myocardial cells was directly measured with this NAE and the results were satisfactory.

Aluminum Oxide↗
PubMed2001

Clinicopathological and molecular genetic analysis of 4 typical Chinese HNPCC families.

AIM: To study the clinicopathological and molecular genetic characteristics of typical Chinese hereditary nonpolyposis cotorectal cancer (HNPCC) families. METHODS: Four typical Chinese HNPCC families were analyzed using microdissection, microsatellite instability analysis, immunostaining of hMSH2 and hMLH1 proteins and direct DNA sequencing of hMSH2 and hMLH1 genes. RESULTS: All five tumor tissues of 4 probands from the 4 typical Chinese HNPCC families showed microsatellite instability at more than two loci (MSI-H or RER+ phenotype). Three out of the 4 cases lost hMSH2 protein expression and the other case showed no hMLH1 protein expression. Three pathological germline mutations (2 in hMSH2 and 1 in hMLH1), which had not been reported previously, were identified. The same mutations were also found in other affected members of two HNPCC families,respectively. CONCLUSION: Typical Chinese HNPCC families showed relatively frequent germline mutation of mismatch repair genes. High-level microsatellite instability and loss of expression of mismatch repair genes correlated closely with germline mutation of mismatch repair genes. Microsatellite instability analysis and immunostaining of mismatch repair gene might serve as effective screening methods before direct DNA sequencing. It is necessary to establish clinical criteria and molecular diagnostic strategies more suitable for Chinese HNPCC families.

Adult↗
PubMed2001

[Multi-resolution blending rendering of the medical structure].

This paper presents a new medical data visualization method called multi-resolution blending rendering which has been developed for visualizing the large medical volume data sets. Different from those multi-resolution rendering methods which simplify the structures by polygon mesh optimization technique, the new method uses different resolution levels to represent different parts of a structure at the same time. So, it can preserve the integrality of the structure and emphasize the important part of the structure when simplifying the structure. The new method also takes advantage of the good qualities of the wavelet transform and constructs the multi-resolution blending model of the structure by orthogonal wavelet transform and transition operator. The experiment proves that our method can effectively simplify the model of the structure, enormously reduce the number of the triangle of the structure and speed up the structure rendering. It is especially suitable for interactive observations on a complex medical structure.

Algorithms↗
PubMed2001

[A new algorithm for displaying the cutting isosurface of structures].

The existing algorithms for displaying the cutting isosurface of the structure are not suitable for interactive display because they spend too much time on calculation when a fair amount of data is submitted to processing. This paper presents a new algorithm for accelerating the cutting of structure by using the area partition and the increment calculation to reduce the unnecessary calculation in cutting the structure. It is suitable for real time interactive displaying, especially in the case of a vast amount of data.

Algorithms↗
PubMed2001

Insights into molecular mechanisms of contact hypersensitivity gained from gene knockout studies.

Contact hypersensitivity (CHS), a dendritic-cell (DC)-dependent, T-cell-mediated skin immune response to reactive haptens, has been a subject of intense research for many years. The molecular mechanisms underlying CHS are complicated and are not fully understood. During the past few years, varieties of gene-targeted knockout mice have been used in the study of CHS. Such studies have contributed significantly to our understanding of the mechanisms responsible for the initiation of CHS. This review focuses on insights into molecular requirements for CHS gained from knockout studies.

Animals↗
PubMed2001

[Research and application of drug controlled release technique in tissue engineering].

OBJECTIVE: To investigate protection of biological activity and controlled release of growth factor by means of drug controlled release technique in tissue engineering. METHODS: Using drug controlled release technique that to embed or microcapsulate the biological drug with biodegradable polymer. RESULTS: The aliphatic polylactone could be used as drug carrier for each drug including the biological matter. And the release behavior of the drug could be controlled by adjusting the molecular structure of the carrier and the controlled release method. The successful example, that to realize regeneration of rat's sciatic nerve with 5, 10, 15 and 20 mm of gap by using polylactide as nerve guide and the embedding growth factor, had been obtained. CONCLUSION: It is possible to realize protection of biological activity and sustained release of growth factor by using aliphatic polylactone as drug carrier.

Adenosine↗
PubMed2001

[Clinicopathological and molecular genetic analysis in Chinese typical hereditary nonpolyposis colorectal cancer pedigrees].

OBJECTIVE: To investigate the clinicopathological and molecular genetic characteristics of Chinese hereditary nonpolyposis colorectal cancer (HNPCC) pedigrees. METHODS: Four Chinese HNPCC pedigrees were studied using microdissection, microsatellite instability analysis, immunohistochemistry staining and direct DNA sequencing for hMSH2 and hMLH1 genes. RESULTS: All five tumor tissues from 4 probands showed high level of microsatellite instability at more than 2 loci(RER + phenotype). Three of 4 cases lost hMSH2 protein expression and one case showed no hMLH1 protein expression. Three pathological germline mutations (2 on hMSH2 and 1 on hMLH1) were identified. CONCLUSIONS: Chinese typical HNPCC kindreds showed relatively frequent germline mutations of mismatch repair genes. Microsatellite instability analysis and immunohistochemistry staining might be the effective screening methods before direct DNA sequencing for the detection of mismatch repair genes. It is necessary to establish clinical criteria and molecular diagnostic strategies more suitable for Chinese HNPCC kindreds.

Adult↗
PubMed2001

Astragali and Angelica protect the kidney against ischemia and reperfusion injury and accelerate recovery.

OBJECTIVE: To investigate the role of Astragali and Angelica (A&A) of Chinese herbs in acute renal ischemia/reperfusion injury, and the related intracellular signal transduction mechanism. METHODS: Acute ischemic renal injury in rats was induced by clamping in renal pedicel for 45 minutes. Rats in therapy group were given a single dose (2 ml/day) of A&A for 3 days before clamping, and then continued for another 3 days. Forty-five minutes after clamping and at different reperfusion time, serum creatinine (Scr) and renal pathological changes were taken and compared in both groups. The proliferating cell nuclear antigen (PCNA) positive cells were detected by immunohistochemistry. Extracelluar regulating kinase (ERK) and c-Jun N-terminal kinase (JNK) activity was assayed by specific substrate phosphorylation with immunoprecipitation. RESULTS: At the 24th hour of reperfusion, Scr was lower in A&A group than that in the control. Much less necrotic tubular cells, casts, and more PCNA-positive cells were found in A&A group. ERK activity decreased after clamping, and recovered at 5 minutes of reperfusion. There was no difference between the two groups. JNK activity did not change after ischemia, but increased at 5 minutes and peaked at 20 minutes of reperfusion. JNK activity was significantly higher in A&A group than that in the control group. CONCLUSION: A&A protected kidney against ischemic insult and accelerated both functional and histological recovery after acute renal ischemia/reperfusion injury, which may associate with the change of JNK signaling pathway.

Angelica↗