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J Cui

Publications and source records attributed to J Cui.

At least 37 records · Page 2Linked to original sources
PubMed2001

Kinetics of hydroxyapatite precipitation at pH 10 to 11.

The mechanism and kinetics of hydroxyapatite (HAP) precipitation from aqueous solution at the conditions of pH 10-11 and at calcium ion concentrations of more than 0.5 mol/l were investigated. The results show that the reaction undergoes the following process: transferring from octacalcium phosphate (OCP) to amorphous calcium phosphate (ACP) rapidly, and then from ACP to calcium-deficient hydroxyapatite (DAP) and HAP. DAP was the non-stoichiometric material that ACP converts to HAP. Reaction temperature greatly affects the reaction rate of the conversion from ACP to HAP. It takes about 24 h to form pure-phase HAP at 25 degrees C while it takes only 5 min at 60 degrees C. The temperature also has a great deal of influence on the particle size and morphology of precipitated hydroxyapatite. The reaction of transformation from ACP to DAP was second order and the activation energy was 95 kJ/mol (22.7 kCal/mol) and therefore it was inferred that the conversion reaction was a surface control process.

Calcium Phosphates↗
PubMed2001

The epidemiology of human trichinellosis in China during 1964-1999.

The large foci of trichinellosis are mainly located in the southeastern, the central and northeastern China. By the end of 1999, human cases with trichinellosis have been recorded in 17 out of 34 Provinces/Autonomous Regions/Municipals (P/A/M) of China. The seroepidemiological surveys of T. spiralis infection in humans were carried out in nine out of 34 P/A/M. The overall seroprevalence was 5.3%. The prevalence detected by muscle biopsy in Henan province was 2.5%. From 1964 to 1999, 548 outbreaks of trichinellosis, with 23,004 cases and 236 deaths, were recorded in 12 P/A/M of China. Pork is the predominant source of outbreaks of human trichinellosis in China, 525 (95.8%) out of 548 outbreaks were caused by eating pork. However, 14 outbreaks resulting from the consumption of mutton and game meat occurred in recent years, suggesting the increasing significance of herbivorous and wild animals as source for human trichinellosis.

Animals↗
PubMed2001

Epidemiology of swine trichinellosis in China.

Swine trichinellosis has been reported in 26 provinces, autonomous regions or municipalities (P/A/M) of China. The prevalence rate in swine varied from 0.12% to 34.2% in five P/A/M, from 0.01% to 0.0001% in other P/A/M. The seroepidemiological survey of swine trichinellosis was carried out by ELISA in seven P/A/M, the seroprevalence varied from 0.09% to 29.63%. The prevalence of Trichinella infection in pork sold at the market was from 0.29% to 5.6% in four provinces. The transmission of trichinellosis by garbage is the main features of epidemiology of swine trichinellosis in China. Rat is an important reservoir in the domestic cycle of trichinellosis. The prevalence rates of T. spiralis infection in rats were from 1.98% to 15.06% in six provinces or autonomous regions. The treatment prophylaxis with forage contained albendazole has been applied to the control of swine trichinellosis in Nanyang area of Henan province, the prevalence of swine trichinellosis had decreased from 32.2% before prophylaxis to 0.12% after prophylaxis.

Animals↗
PubMed2001

Outbreaks of human trichinellosis caused by consumption of dog meat in China.

Dog meat has become an important source of Trichinella infection for humans in China. The first documented outbreak of human trichinellosis resulting from the consumption of dog meat occurred in China in 1974. Until 1999, the outbreaks with this source of infection occurred mostly in Northeast of China (81 cases in five outbreaks in Jilin and two in Liaoning), Beijing (six cases) and Henan provinces (two cases). The epidemiological surveys were performed in nine Provinces or Autonomous Regions of China among 19,662 dogs samples. Dogs trichinellosis prevalence ranged from 7% in Henan to 39.5% in Heilongjiang, with an overall prevalence of 21.1%. Based on random amplified polymorphic DNA fingerprint (RAPD), some dog isolates of Heilonjiang and Jilin provinces were recently identified as Trichinella nativa, suggesting that this parasite is widely distributed among dogs in Northeast of China, while Trichinella spiralis in swine appears to be a common parasite throughout China. Since the Trichinella larvae in dog meat is resistant to freezing, caution should be paid to the consumption of dog meat even if it had been frozen.

Animals↗
PubMed2001

Distribution of family history of a disease as a function of mode of inheritance, genetic relative hazard, allele frequency and disease status of the proband, with application to female breast cancer.

BACKGROUND: This paper aims to determine the family history distribution of a particular disease as a result of its specific genetic aetiology, defined by the mode of inheritance (dominant or recessive), allele frequency, and increased risk in carriers of the genetic risk (genetic relative hazard). Here, 'family history' is the number of affected first-degree relatives of a defined index person (termed the proband), who may be either affected or unaffected with the disease in question. METHODS: We consider model parameters relevant for female breast cancer in Australia. Breast cancer affects one sex only, although the extension of the model to both sexes is straightforward. RESULTS: Contour plots of the relationships between family history distribution and genetic parameters, for both dominant and recessive inheritance, are displayed for the proband being either affected or unaffected. CONCLUSIONS: Under dominant inheritance and an allele frequency of 0.005 (as may be appropriate for mutations in the genes BRCA1 and BRCA2), the proportion of affected probands diagnosed with breast cancer before age 50 years and who have no family history is stable as the genetic relative hazard increases from 5 to 20, decreasing from 89% to 85%. The probability that a proband has a family history is higher when the proband is affected compared with when she is not. For allele frequency 0.005 and relative hazard 10, the ratio of the probability of i (i = 1, 2, 3 or more) affected relatives for an affected proband compared with an unaffected proband is 1.2, 2 and 4.5 respectively, under dominant inheritance. Under recessive inheritance with allele frequency 0.35 and relative hazard 3 (as may be the case for a common polymorphism in the CYP17 gene), the corresponding ratios are 1.1, 1.3 and 1.5, respectively.

Adult↗
PubMed2001

Intracellular Mg(2+) enhances the function of BK-type Ca(2+)-activated K(+) channels.

BK channels modulate neurotransmitter release due to their activation by voltage and Ca(2+). Intracellular Mg(2+) also modulates BK channels in multiple ways with opposite effects on channel function. Previous single-channel studies have shown that Mg(2+) blocks the pore of BK channels in a voltage-dependent manner. We have confirmed this result by studying macroscopic currents of the mslo1 channel. We find that Mg(2+) activates mslo1 BK channels independently of Ca(2+) and voltage by preferentially binding to their open conformation. The mslo3 channel, which lacks Ca(2+) binding sites in the tail, is not activated by Mg(2+). However, coexpression of the mslo1 core and mslo3 tail produces channels with Mg(2+) sensitivity similar to mslo1 channels, indicating that Mg(2+) sites differ from Ca(2+) sites. We discovered that Mg(2+) also binds to Ca(2+) sites and competitively inhibits Ca(2+)-dependent activation. Quantitative computation of these effects reveals that the overall effect of Mg(2+) under physiological conditions is to enhance BK channel function.

Animals↗
PubMed2001

The TASTY locus on chromosome 1 of Arabidopsis affects feeding of the insect herbivore Trichoplusia ni.

The generalist insect herbivore Trichoplusia ni (cabbage looper) readily consumes Arabidopsis and can complete its entire life cycle on this plant. Natural isolates (ecotypes) of Arabidopsis are not equally susceptible to T. ni feeding. While some are hardly touched by T. ni, others are eaten completely to the ground. Comparison of two commonly studied Arabidopsis ecotypes in choice experiments showed that Columbia is considerably more resistant than Landsberg erecta. In no-choice experiments, where larvae were confined on one or the other ecotype, weight gain was more rapid on Landsberg erecta than on Columbia. Genetic mapping of this difference in insect susceptibility using recombinant inbred lines resulted in the discovery of the TASTY locus near 85 cM on chromosome 1 of Arabidopsis. The resistant allele of this locus is in the Columbia ecotype, and an F(1) hybrid has a sensitive phenotype that is similar to that of Landsberg erecta. The TASTY locus is distinct from known genetic differences between Columbia and Landsberg erecta that affect glucosinolate content, trichome density, disease resistance, and flowering time.

Animals↗
PubMed2001

Induction of host gene expression following infection of chicken embryo fibroblasts with oncogenic Marek's disease virus.

Microarrays containing 1,126 nonredundant cDNAs selected from a chicken activated T-cell expressed sequence tag database (http://chickest.udel.edu) were used to examine changes in host cell gene expression that accompany infection of chicken embryo fibroblasts (CEF) with Marek's disease virus (MDV). Host genes that were reproducibly induced by infection of CEF with the oncogenic RB1B strain of MDV included macrophage inflammatory protein, interferon response factor 1, interferon-inducible protein, quiescence-specific protein, thymic shared antigen 1, major histocompatibility complex (MHC) class I, MHC class II, beta(2)-microglobulin, clusterin, interleukin-13 receptor alpha chain, ovotransferrin, a serine/threonine kinase, and avian leukosis virus subgroup J glycoprotein.

Animals↗
PubMed2001

Src tyrosine kinase is the trigger but not the mediator of ischemic preconditioning.

The signal cascade that triggers and mediates ischemic preconditioning (IPC) remains unclear. The present study investigated the role of the Src family of tyrosine kinases in IPC. Isolated and buffer-perfused rat hearts underwent IPC with three cycles of 5-min ischemia and 5-min reperfusion, followed by 30-min ischemia and 120-min reperfusion. The Src tyrosine kinase family-selective inhibitor PP1 was administered between 45 and 30 min before ischemia (early PP1 treatment) or for 15 min before IPC [early PP1-preconditioning (PC) treatment]. PP1 was also administered for 5 min before the sustained ischemia (late PP1 treatment) or after IPC (late PP1-PC treatment). Src kinase was activated after 30 min of ischemia in both the membrane and cytosolic fractions. Src kinase was also activated by IPC but was attenuated after the sustained ischemia. Early and late PP1 treatment inhibited Src activation after the sustained ischemia and reduced infarct size. Early PP1-PC inhibited Src activation after IPC but not after the sustained ischemia and blocked cardioprotection afforded by IPC. Late PP1-PC treatment abrogated IPC-induced activation of Src and protein kinase C (PKC)-epsilon in the membrane but not in the cytosolic fraction. This treatment modality abrogated Src activation after the sustained ischemia and failed to block cardioprotection afforded by IPC. These results suggest that Src kinase activation mediates ischemic injury but triggers IPC in the position either upstream of or parallel to membrane-associated PKC-epsilon.

Animals↗
PubMed2001

Muscle sympathetic outflow during horizontal linear acceleration in humans.

To elucidate the effects of linear acceleration on muscle sympathetic nerve activity (MSNA) in humans, 16 healthy men were tested in a linear accelerator. Measurements of MSNA, electrocardiogram, blood pressure, and thoracic impedance were undertaken during linear acceleration. Sinusoidal linear acceleration with peak values at +/-0.10, +/-0.15, and +/-0.20 G was applied in anteroposterior (+/-G(x), n = 10) or lateral (+/-G(y), n = 6) directions. The total activity and burst rate of MSNA decreased significantly during forward, backward, left, or right linear accelerations. The total activity of MSNA decreased to 50.5 +/- 6.9, 52.5 +/- 4.4, 71.2 +/- 9.6, and 67.6 +/- 8.2% from the baselines (100%) during linear accelerations with peak values at +/-0.20 G in the four directions, respectively. These results suggest that dynamic stimulation of otolith organs in horizontal directions in humans might inhibit MSNA directly in order to quickly redistribute blood to muscles during postural reflexes induced by passive movement, which supports the concept that the vestibular system contributes to sympathetic regulation in humans.

Acceleration↗
PubMed2001

Effects of lower body positive pressure on muscle sympathetic nerve activity response to head-up tilt.

The present study was performed to test the hypothesis that application of lower body positive pressure (LBPP) during orthostasis would reduce the baroreflex-mediated enhancement in sympathetic activity in humans. Eight healthy young men were exposed to a 70 degrees head-up tilt (HUT) on application of 30 mmHg LBPP. Muscle sympathetic nerve activity (MSNA) was microneurographically recorded from the tibial nerve, along with hemodynamic variables. We found that in the supine position with LBPP, MSNA remained unchanged (13.4 +/- 3.3 vs. 11.8 +/- 2.3 bursts/min, without vs. with LBPP; P > 0.05), mean arterial pressure was elevated, but arterial pulse pressure and heart rate did not alter. At 70 degrees HUT with LBPP, the enhanced MSNA response was reduced (33.8 +/- 5.0 vs. 22.5 +/- 2.2 bursts/min, without vs. with LBPP; P < 0.05), mean arterial pressure was higher, the decreased pulse pressure was restored, and the increased heart rate was attenuated. We conclude that the baroreflex-mediated enhancement in sympathetic activity during HUT was reduced by LBPP. Application of LBPP in HUT induced an obvious cephalad fluid shift as well as a restoration of arterial pulse pressure, which reduced the inhibition of the baroreceptors. However, the activation of the intramuscular mechanoreflexes produced by 30 mmHg LBPP might counteract the effects of baroreflexes.

Adult↗
PubMed2001

Baroreflex modulation of muscle sympathetic nerve activity during posthandgrip muscle ischemia in humans.

To identify whether muscle metaboreceptor stimulation alters baroreflex control of muscle sympathetic nerve activity (MSNA), MSNA, beat-by-beat arterial blood pressure (Finapres), and electrocardiogram were recorded in 11 healthy subjects in the supine position. Subjects performed 2 min of isometric handgrip exercise at 40% of maximal voluntary contraction followed by 2.5 min of posthandgrip muscle ischemia. During muscle ischemia, blood pressure was lowered and then raised by intravenous bolus infusions of sodium nitroprusside and phenylephrine HCl, respectively. The slope of the relationship between MSNA and diastolic blood pressure was more negative (P < 0.001) during posthandgrip muscle ischemia (-201.9 +/- 20.4 units. beat(-1). mmHg(-1)) when compared with control conditions (-142.7 +/- 17.3 units. beat(-1). mmHg(-1)). No significant change in the slope of the relationship between heart rate and systolic blood pressure was observed. However, both curves shifted during postexercise ischemia to accommodate the elevation in blood pressure and MSNA that occurs with this condition. These data suggest that the sensitivity of baroreflex modulation of MSNA is elevated by muscle metaboreceptor stimulation, whereas the sensitivity of baroreflex of modulate heart rate is unchanged during posthandgrip muscle ischemia.

Adult↗
PubMed2001

Type 1 protein tyrosine kinases in Chinese breast carcinomas: a clinicopathologic study.

Immunostaining for epidermal growth factor receptor (EGFR), c-erbB-2, c-erbB-3, c-erbB-4, ER, and PR was performed in 107 cases of primary breast carcinomas from Anyang, China. The expression rates of EGFR, c-erbB-2, c-erbB-3 and c-erbB-4 in this series were 43.9%, 36%, 27%, and 45.8%, respectively, and a stronger c-erbB-4 staining of "normal" glandular structures inside tumors and in the vicinity of tumor clusters was confirmed. Larger tumor size, lymph node metastases, and higher histologic grade in invasive ductal carcinomas were shown to be statistically valuable negative prognostic factors, and c-erbB-2 expression was also weakly associated with a poor prognosis no matter what the nodal status. The expressions of c-erbB-4 and ER in invasive ductal carcinomas were inversely associated with histologic grade of the tumors. Associations between the expression of c-erbB-4 and ER (p = 0.001) and the expression of ER and PR study (p = 0.004) were found in the present study. No significant associations between the expressions of EGFR, c-erbB-3, c-erbB-4, ER, and PR and overall survival were detected. The expression of c-erbB-4 in the node negative group was, however, associated with a better prognosis, indicating a different role of c-erbB-4 protein in breast tumor development than other EGFR family members have. Int J Surg Pathol 9(3):177-187, 2001

Adult↗
PubMed2001

Abnormal beta-catenin gene expression with invasiveness of primary hepatocellular carcinoma in China.

AIM: To study the abnormal expression of beta-catenin gene and its relationship ith invasiveness of primary hepatocellular carcinoma among Chinese people. METHODS: Thirty-four hepatocellular carcinoma (HCC) specimens and adjacent para-cancerous tissues, 4 normal liver tissues were immunohistochemically stained to study subcellular distribution of beta-catenin. Semiquantitive analysis of expression of beta-catenin gene exon 3 mRNA was examined by RT-PCR and in situ hybridization. The relationship between expressions of both beta-catenin protein, mRNA and clinicopathological characteristics of HCC was also analyzed. RESULTS: Immuno-histochemistry showed that all normal liver tissues and para-cancerous tissues examined displayed membranous type staining for beta-catenin protein, occasionally with weak expression in the cytoplasm. While 21 cases (61.8%) of HCC examined showed accumulated type in cytoplasms or nuclei. The accumulated type Labling Index (LI) of cancer tissue and para-cancerous tissue was (59.9 +/- 26.3) and (18.3 +/- 9.7) respectively (P<0.01). Higher accumulated type LI was closely related with invasiveness of HCC. Results of RT-PCR showed the beta-catenin gene exon 3 mRNA Expression Index (EI) of 34 HCCs was higher than that of para-cancerous tissue and normal liver tissue. Using in situ hybridization, the signal corresponding to beta-catenin gene exon 3 mRNA was particularly strong in cytoplasm of HCC when compared with those of para-cancerous and normal liver tissues. Over expression of beta-catenin exon 3 was also found to be correlated with high metastatic potential of HCC. CONCLUSION: Abnormal expression of beta-catenin gene may contribute importantly to the invasiveness of HCC among Chinese people.

Cadherins↗
PubMed2001

[Methylation status of c-fms oncogene in hepatocellular carcinoma and its relation with clinical pathology].

OBJECTIVE: To study the methylation status change of c-fms oncogene in hepatocellular carcinogenesis, and to clarify the abnormal highly expressing mechanism of c-fms/CSF-1R in hepatocellular carcinoma (HCC). METHODS: Genome DNA of 30 cases of HCC tissue and matching surrounding-cancer tissue were digested with restrictive endonucleases Hpa II/Msp I. Methylation status of c-fms oncogene was tested with Southern blot. Methylation status of c-fms oncogene in the HCC tissue and the matching surrounding-cancer tissue was compared. The relation between methylation status of c-fms oncogene and clinical pathology of HCC was determined. RESULTS: Methylation status of c-fms oncogene decreased in 36.7% (11/30) HCC tissue and 13.3% (4/30) matching surrounding-cancer tissue. The hypomethylation rate of c-fms oncogene in the HCC tissue was higher than that in the matching surrounding-cancer tissue. There was significant correlation between Edmondson scale of HCC and hypomethylation of c-fms oncogene. The hypomethylation rate of HCC in Edmondson III-IV was higher than that in Edmondson I-II. CONCLUSIONS: Hypomethylation of c-fms oncogene may be an important molecular mechanism leading to abnormally high expressing of CSF-1R, which contributes to occurrence and deterioration of HCC.

Adult↗
PubMed2001

[Relationship of vitamin D receptor polymorphism with breast cancer].

OBJECTIVE: To detect the association between vitamin D receptor polymorphism and breast cancer. METHODS: Polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) method was used. Two restriction fragment length polymorphisms in the 3'region of vitamin D receptor (VDR) gene, Taq I and Apa I, were tested for association with breast cancer risk in 86 females with breast cancer and 134 healthy female controls. RESULTS: Allele frequencies of the 3'Taq I polymorphism showed a significant association (P=0.0004, OR:5.39,CI:1.81-17.20). The further study of genotype found the association of Tt, tt with breast cancer. The haplotype analysis of Apa I and Taq I showed a linkage disequilibrium between t-allele and A-allele. The frequency of tA haplotype was higher in breast cancer patients than in controls (P=0.001), indicating that tA haplotype is associated with breast cancer. The alleles and haplotype of the two loci had not any difference among the clinical subgroups. CONCLUSION: There is association between vitamin D receptor polymorphism and breast cancer.

Adult↗