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Biomedical subjects

J Cui

Publications and source records attributed to J Cui.

At least 127 records · Page 7Linked to original sources
PubMed1999

[Passive personal sampler for exposure to low concentration of volatile organic compounds].

A passive personal sampler has been developed for monitoring volatile organic compounds(VOCs) in ambient air and nonoccupational exposure. The sampler collecting target VOCs is based upon the mechanism of molecular diffusion and absorption onto a single layer of active carbon fibre (ACF) absorbent. After exposure, the ACF is transferred from the sampler into stainless steel tubes for thermal desorption. The desorbed target VOCs is analyzed by capillary GC. Under the condition of facing velocity of 10-260 cm/s, relative humidity of 30%-80%, and temperature of 10-30 C, the sampling rate for benzene, toluene, tetrachloroethylene, p-xylene and styrene is 25.74, 25.16, 25.85, 8.16 and 6.47 ml/min respectively. The analysis on the new passive sampler demonstrated that its relative overall uncertainty for target VOCs was in the range of +/- 25% compared with the active ACF tube sampling method.

Air Pollutants↗
PubMed1999

Diagnosis of trichinosis by indirect fluorescent antibody test with Trichinella larva section.

AIM: To evaluate the value of indirect fluorescent antibody test (IFAT) in diagnosing trichinosis. METHODS: IFAT using frozen section of the purified Trichinella larvae as antigen was employed to detect anti-Trichinella antibodies in sera from mice infected with Trichinella spiralis and the patients with trichinosis. Sera from patients with trichinosis were collected at different time intervals after onset of the disease and after treatment with albendazole. Sera from patients with other parasitic diseases and healthy individuals were used as control. RESULTS: The anti-Trichinella antibodies were detected in 15 infected mice as early as 2 weeks after infection, and in 86.5% of 467 patients with trichinosis. Sera from patients with filariasis, echinococcosis and healthy controls were all negative. 8 of 48 (16.7%) cases with paragonimiasis showed positive cross reaction. The antibody positive rate of patients with trichinosis was 70.2% one week after onset of disease and increased to 91.0%, 95.8% and 100% at two, three and four weeks after onset, respectively. The frozen section of the larvae can be stored at -20 degrees C for 5 years without loss of antigenicity. The IFAT positive rate was increased from 87.5% before treatment to 100% one week after treatment, and the serum antibody titers were elevated as well. The antibody negative conversion rate of the patients was 24% at one month after teratment and increased to 75% at four months after treatment. CONCLUSION: IFAT using frozen section of the purified Trichinella larvae as antigen is highly sensitive and specific for the diagnosis of trichinosis and evaluation of the therapeutic effect.

Animals↗
PubMed1998

Attenuation of regional differentiation of sympathetic nerve activity during sleep in humans.

The purpose of the present study was to clarify how the regional differentiation of sympathetic nerve activity (SNA) is modified during natural sleep in humans. In humans, muscle and skin sympathetic nerve activities (MSNA, SSNA) have been reported to discharge independently according to a regional differentiation of SNA during wakefulness. However, in natural sleep, MSNA and SSNA have been documented to synchronize during sleep stage 2 (Rechtschaffen and Kales). In the present study, we measured MSNA and SSNA simultaneously using a double recording technique of microneurography in eight healthy volunteers during natural sleep, and analyzed how MSNA and SSNA can be synchronized. We found that the synchronicity of MSNA and SSNA was accelerated in correlation with the deepening of the non-rapid eye movement (nonREM) sleep stages. We also documented that the burst properties of MSNA different from those of SSNA in wakefulness become similar to those of SSNA in the sleep stage, and MSNA synchronizes with SSNA. The synchronicity of MSNA and SSNA is presumably caused by a reduced effect of central inhibitory baroreflex pathways on MSNA during nonREM sleep. The present findings suggest that the regional differentiation of sympathetic nerve activity is attenuated with the deepening of nonREM sleep stages.

Adult↗
PubMed1998

[Loss of heterozygosity and microsatellite instability in the region including BRCA1 of breast cancer in Chinese].

OBJECTIVE: To shed light on the relationship between BRCA1 gene and breast cancer in Chinese Han women. METHODS: Four microsatellites DNA (D17S855, D17S579, D17S1327 and THRA1) within the BRCA1 gene were used as polymorphic markers. A study of loss of heterozygosity(LOH) and microsatellite instability(MSI) at the above- mentioned 4 microsatellites of 50 breast cancer patients was conducted by using PCR -PAUGE-DNA silver staining (polymerase chain reaction-polyacrylamide urea gel electrophoresis) method. RESULTS: Twenty-nine or 58% of the informative cases showed LOH; 35.71%, 15. 38%, 18.18%, and 26.19% of the informative cases showed positive LOH at the D17S855, D17S579, D17S1327 and THRA1 loci respectively. The rate of MSI was 46%, and the rates of MSI at the four loci were 16%, 18%, 18% and 12% respectively. Further study on the associations between the phenomena of LOH and MSI and different clinical stages revealed that MSI was an early event in mammary tumorigenesis while LOH occurred at a later stage. CONCLUSION: All of these suggest that breast cancer in Chinese be somehow linked to BRCA1.

Breast Neoplasms↗
PubMed1998

Epidemiological, clinical and serological studies on trichinellosis in Henan Province, China.

The epidemiological, clinical and serological studies on human trichinellosis in Henan Province were carried out from January 1992 to December 1996. The results showed that 467 patients attending our department came from 12 administrative areas and cities of the Province and they acquired the infection mainly by eating undercooked dumplings, tasting the raw pork filling for dumplings, ingesting scalded pork or mutton. There was the high incidence season of trichinellosis during the winter. Most of the patients were workers, officers and merchants aged 20-49 years, and the incidence was higher in males than in females. The main clinical manifestations of trichinellosis were fever, general myalgia, muscle tiredness and eosinophilia. Most of the patients had not any gastrointestinal symptoms and rash. Eyelid edema was only seen in the early courses of the disease. Eosinophil count increased with time, reached to the peak 3 weeks and decreased markedly 6 weeks after the onset of the disease. Eosinophil levels elevated obviously 1 week after therapy, began to drop rapidly 2 weeks after therapy, and decreased to a near normal levels 4 weeks after therapy. Anti-Trichinella antibodies were detected by IFAT using the frozen sections of the purified T. spiralis larvae as antigen. The specific antibodies were observed in only 70.2% of patients one week after onset of disease, and increased to 91, 94.3, and 100%; 2, 3, and 4 weeks, respectively after the onset. The antibody positive rate was evidently increased to 100% 1 week after therapy with abendazole, then decreased to 25% 4 months after therapy.

Adolescent↗
PubMed1998

An outbreak of paragonimiosis in Zhengzhou city, China.

An outbreak of paragonimiosis occurred in the city of Zhengzhou, Central China, in May 1995. Of seven exposed urban inhabitants, four were seropositive for Paragonimus and had clinical symptoms consistent with acute paragonimiosis. All of four cases treated were cured with praziquantel. The P. skrjabini adult worm was obtained from the rats experimentally infected with the crabs collected in the mountainous area where the urban inhabitants had got the infection. The outbreak was attributed to the intake of raw freshwater crabs while on tourist trips in a mountainous area.

Adolescent↗
PubMed1998

The structure and function of murine factor V and its inactivation by protein C.

Factor V (FV) is a central regulator of hemostasis, serving both as a critical cofactor for the prothrombinase activity of factor Xa and the target for proteolytic inactivation by the anticoagulant, activated protein C (APC). To examine the evolutionary conservation of FV procoagulant activity and functional inactivation by APC, we cloned and sequenced the coding region of murine FV cDNA and generated recombinant wild-type and mutant murine FV proteins. The murine FV cDNA encodes a 2,183-amino acid protein. Sequence comparison shows that the A1-A3 and C1-C2 domains of FV are highly conserved, demonstrating greater than 84% sequence identity between murine and human, and 60% overall amino acid identity among human, bovine, and murine FV sequences. In contrast, only 35% identity among all three species is observed for the poorly conserved B domain. The arginines at all thrombin cleavage sites and the R305 and R504 APC cleavage sites (corresponding to amino acid residues R306 and R506 in human FV) are invariant in all three species. Point mutants were generated to substitute glutamine at R305, R504, or both (R305/R504). Wild-type and all three mutant FV recombinant proteins show equivalent FV procoagulant activity. Single mutations at R305 or R504 result in partial resistance of FV to APC inactivation, whereas recombinant murine FV carrying both mutations (R305Q/R504Q) is nearly completely APC resistant. Thus, the structure and function of FV and its interaction with APC are highly conserved across mammalian species.

Amino Acid Sequence↗
PubMed1998

Natural killer-like nonspecific tumor cell lysis mediated by specific ligand-activated Valpha14 NKT cells.

We have recently identified alpha-galactosylceramide (alpha-GalCer) as a specific ligand for an invariant Valpha14/Vbeta8.2 T cell receptor exclusively expressed on the majority of Valpha14 NKT cells, a novel subset of lymphocytes. Here, we report that alpha-GalCer selectively activates Valpha14 NKT cells resulting in prevention of tumor metastasis. The effector mechanisms of the ligand-activated Valpha14 NKT cells seem to be mediated by natural killer (NK)-like nonspecific cytotoxicity. Indeed, the cytotoxic index obtained by alpha-GalCer-activated Valpha14 NKT cells was reduced by the addition of cold target tumor cells or by treatment with concanamycin A, which inhibits activation and secretion of perforin, but not by mAbs against molecules involved in the NKT cell recognition and conventional cytotoxicity, such as CD1d, Vbeta8, NK1. 1, Ly49C, Fas, or Fas ligand. These results suggest that the ligand-activated Valpha14 NKT cells kill tumor cells directly through a CD1d/Valpha14 T cell receptor-independent, NK-like mechanism.

Animals↗
PubMed1998

The role of ras gene mutation in gastric cancer and precancerous lesions.

Abnormality of ras gene family was studied in a total of 206 cases of gastric cancer and precancerous lesions by PCR-RFLP, PCR-SSCP and DNA sequencing. The results showed that mutation rate of H-ras 12 codon in metaplasia, atypical hyperplasia, early-stage cancer and advanced cancer was 16.7%, 31.2%, 50.0%, and 32.2%, respectively. In the groups of superficial gastritis and normal controls, no mutation were detected in codon 12 of ras. Mutations of H-ras 61 codon and N-ras 12 codon in various groups were the same as those in normal control. K-ras 12 codon mutation was detected in only 2 cases of gastric cancer by using PCR-SSCP, but it was not detected by DNA sequencing, which may be polymorphism. All H-ras 12 codon mutations were G-->T mutation. There were significant difference between the groups of metaplasia, dysplasia, gastric carcinoma and normal control group (P < 0.05, P < 0.01, P < 0.01, respectively). It was concluded that H-ras 12 codon mutation was an early event and may play an important role in gastric carcinogenesis. Although K-ras, N-ras mutation rates are high in colon cancer and leukemia, it seems to bear no relationship with gastric cancer.

Gastric Mucosa↗
PubMed1998

Chromosome 7 abnormalities in prostate cancer detected by dual-color fluorescence in situ hybridization.

Aneusomy of chromosome 7 and loss at 7q (especially 7q31.1) have been reported in prostate cancer. To further investigate abnormalities of 7q and the relationship with whole chromosome 7 changes, we have conducted a dual-color fluorescence in situ hybridization (FISH) analysis on isolated nuclei from 28 primary prostate cancers. A pericentromeric probe for chromosome 7, five newly isolated sequence-specific bacterial artificial chromosome (BAC) probes from 7q31.1, and one BAC for the epidermal growth factor receptor (EGFR) gene at 7p12 were used in dual color hybridizations. Pericentromeric probes for chromosomes X and 4 were also used as controls. Sixteen (57.1%) of the 28 tumors showed clonal aberrations. Nine of them were trisomy 7 and four were hypertetrasomy for chromosome 7. Deletions at 7q31.1 were found in two of the high grade tumors. With the exception of these two cases, all other cases showed concordant results using all probes. These findings confirm previous studies that aneusomy of 7 is associated with prostate cancer progression, and there may be a tumor suppressor gene (TSG) at 7q31.1 which is associated with tumor progression. In addition, our study indicates: (1) the deletion pattern of individual nuclei infers that deletions at 7q31.1 precede reduplications of chromosome 7; and (2) the amplification of EGFR was not detected at the DNA level, suggesting that activation of this oncogene may play a minor role in prostate cancer.

Aneuploidy↗
PubMed1998

Phosphorylcholine-coated metallic stents in rabbit iliac and porcine coronary arteries.

The arterial wall reaction to phosphorylcholine-coated metal stents was examined in rabbits and pigs. Compared to non-coated stents, no significant difference was found by angiography and histology. We conclude that although phosphorylcholine-coating does not provoke arterial neointima formation or decrease luminal diameter compared to stainless steel stents, the coating does not seem to reduce restenosis.

Angiography↗
PubMed1998

Changing pattern of delays in reporting AIDS diagnoses in Australia.

To accurately monitor and predict the progress of the HIV/AIDS epidemic, it is important to adjust reported AIDS counts for reporting delays. This requires estimation of the reporting delay distribution. This paper aims to use a statistical model to identify the main factors influencing reporting delays in Australia and to adjust reported incidence data for these delays among cases of AIDS diagnosed from 1993 and reported before 30 June 1997. Reporting delays were found to vary significantly across states/territories. The influence of calendar time of diagnosis was also significant, with an overall trend toward longer delays over time. AIDS cases diagnosed in the fourth quarter of a year were reported significantly more quickly than those diagnosed in the first or third quarters. No significant differences were found due to sex, age and HIV exposure category, except people with haemophilia, in whom AIDS cases appeared to be reported more slowly. After adjusting for under-reporting and reporting delay, we found that the AIDS incidence in Australia was declining from about 1000 cases per year in 1994 to about 760 cases per year in 1996.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Hypoglycemic effect of water-soluble polysaccharide from Auricularia auricula-judae Quel. on genetically diabetic KK-Ay mice.

The hypoglycemic effect of water-soluble polysaccharide(FA) from fruiting bodies of Auricularia auricula-judae Quel. was investigated on genetically diabetic mice (KK-Ay) from 10 to 14 weeks of age. Male mice were divided into 3 groups, the control group and FA-fed group having free access to the control diet or FA diet (30 g of FA/kg of diet). The food-restricted group had restricted access to the control diet at the level of the diet consumed by the FA-fed group. Compared with the control group, FA supplementation had a significant effect in lowering plasma glucose, insulin, urinary glucose, and food intake. FA administration also increased the tolerance to intraperitoneal glucose loading and the hepatic glycogen content. In the food-restricted group, the reduced food intake slightly lowered the plasma and urinary glucose levels, but did not improve hyperinsulinemia and glucose tolerance. This study shows that FA had a hypoglycemic effect on KK-Ay mice, and the reduced food consumption was not a major factor which contributed to the hypoglycemic action of FA.

Agaricales↗
PubMed1998

The effect of bu shen sheng xue fang on beta-thalassemia at gene level.

Isoelectrofocusing electrophoresis, PCR-SSCP analysis with DNA direct sequencing and RT-PCR were used to analyze the constituents of hemoglobin, determine the pattern of globin gene mutation, and detect its mRNA transcription extent. The results indicated that Bu Shen Sheng Xue Fang (BSSXF) significantly increased the contents of hemoglobin (Hb) and fetal hemoglobin (HbF), and the chain ratio in patients with beta-thalassemia. The drug is markedly effective in heterozygous, but not effective in homozygous or genetic compound patients. It was suggested that the beta-globin gene defects were compensated by elevating the gamma/beta + gamma ratio, promoting the transcription and expression of gamma-globin gene in synthesizing HbF.

Adolescent↗
PubMed1998

[Development of emission models for volatile organic compounds from indoor materials].

Volatile organic compounds (VOCs) emitted from indoor materials was a major cause of indoor air pollution. The characteristics of VOCs emission was an important part of research programs on indoor air quality. The technology of test chambers with exactly controllable conditions has been successfully used in studies of VOCs emissions. The technology could be used to model the chamber VOCs concentration level vs time profile C(t), which could in turn be used to estimate the sample emission rate vs time profile R(t). The emission models of VOCs from indoor materials were presented in this review. The principal of emission process, parameters and the applications of emission models were introduced. The application of diffusion model, dilution model and vapor pressure (VP) model were limited due to the existence of sink effect. Sink model is the most promising model at present.

Air Pollution, Indoor↗
PubMed1998

MR imaging in rat glioma model and gene therapy using EGFR antisence RNA.

OBJECTIVE: To study the value of 1.5T MRI in long-term follow-up of rat C6 glioma model and the efficacy of EGFR antisence RNA therapy in vivo. METHODS: Forty-three male Wistar rats, weighing 150 to 200 g, were used for this study. They were divided into four groups: group I (7 normal rats); group II (16 rats inoculated C6 cells in the right caudate nucleus); group III (12 rats with the C6 gliomas treated with EGFR antisence RNA by in site injection); and group IV (8 rats inoculated C6 cells transfected with EGFR antisence RNA in the right caudate nucleus). Group I was examined by plain and enhanced MR scanning. Group II-IV were followed up by plain and enhanced MR scanning and were sacrificed in variable time points for pathological examination. RESULTS: Cerebral hemispheres of normal rat were shown clearly on the MR image. The tumor could be seen about 1 week after inoculation. According to the findings on the follow-up MR scan, we could observe growth of the tumor or its regression after treatment. The tumor growth was significantly inhibited in group III and group IV as compared to those in group II. CONCLUSION: The growth of the rat C6 glioma model and its change after treatment could be shown clearly in 1.5T MR imaging; EGFR antisence RNA significantly inhibited the growth of glioma in vivo.

Animals↗
PubMed1998

Changes in muscle sympathetic nerve activity and effect of breathing maneuvers during microgravity induced by parabolic flight in humans.

UNLABELLED: This study aimed to clarify how muscle sympathetic nerve activity (MSNA) in humans, which plays an important role in blood pressure control against gravity, is altered under microgravity (microG) conditions, and how the MSNA change is modified by breathing maneuvers. Ten subjects seated themselves in a jet aircraft with their knees extended. MSNA was recorded microneurographically from the left tibial nerve with simultaneous monitoring of ECG, blood pressure, respiration, and intrathoracic blood volume estimated by the impedance method during parabolic flight in a jet aircraft. In half of the parabolas, their respiration was controlled at 0.25 Hz by a metronome. RESULTS: MSNA was enhanced under hypergravity just before microG entry, and immediately suppressed by microG induced by parabolic flight. The suppression was more marked with controlled than with uncontrolled respiration (51.6 +/- 7.2 vs 82.8 +/- 2.5%, mean +/- SE, 1G=100%). MSNA changes during microG correlated significantly to changes in blood pressure and intrathoracic blood volume. The blood pressure fall 10 to 15 sec after microG entry was less prominent with controlled than with uncontrolled respiration. We conclude that changes in arterial blood pressure and intrathoracic blood volume modulate MSNA during microG induced by parabolic flight, depending largely on breathing maneuvers.

Adult↗