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Biomedical subjects

Li Jiang

Publications and source records attributed to Li Jiang.

At least 73 records · Page 4Linked to original sources
PubMed2005

Pulmonary metastases: effect of CT section thickness on measurement--initial experience.

PURPOSE: To assess the effect of commonly used computed tomographic (CT) section thicknesses on metastatic tumor measurements calculated with unidimensional, bidimensional, area, and volumetric methods. MATERIALS AND METHODS: Analysis and data collection were approved by the Institutional Review Board, with waived informed patient consent. Forty-two pulmonary metastases in 10 patients (three men and seven women; age range, 43-83 years; mean age, 65.4 years) were analyzed on CT scans obtained with 3.75-, 5.0-, and 7.5-mm section thicknesses. The lesions were automatically delineated by using a three-dimensional multicriteria segmentation algorithm. Unidimensional (the largest diameter), bidimensional (the product of the two maximal perpendicular diameters), maximal cross-sectional area, and volumetric measurements were automatically obtained for each pulmonary lesion on each section thickness. Means and variances were calculated, and the differences across the three section thicknesses for each of the four measurements were studied by using linear mixed-effects models. The Levene test was used to study the equality of variances. RESULTS: Differences in the means for unidimensional, bidimensional, and area measurements were significant between a section thickness of 3.75 and 5.0 mm (unidimensional, P=.05; bidimensional, P=.05; area, P=.01) and 3.75 and 7.5 mm (unidimensional, P=.06; bidimensional, P=.03; area, P=.02), but not 5.0 and 7.5 mm. There was a significant difference in volumetric measurement as section thickness decreased from 7.5 to 5.0 mm (P <.001) and from 7.5 to 3.75 mm (P <.001). Although there was a slight trend for differences in the variances across section thickness for each measurement, none of the differences were significant. CONCLUSION: Volumetric tumor measurements change with a reduction in section thickness from 7.5 to 5.0 and 3.75 mm. For unidimensional measurement, no change was found when thickness decreased from 7.5 to 5.0 mm.

Adult↗
PubMed2005

Association of Fas-670 gene polymorphism with inflammatory bowel disease in Chinese patients.

AIM: Recent studies suggest that Fas-mediated apoptosis is involved in the pathogenesis of inflammatory bowel disease (IBD). It has been hypothesized that either increased apoptosis of intestinal epithelium or decreased apoptosis of lamina propria lymphocytes may induce inflammation of gut. The aim of this study was to determine whether the Fas gene promoter polymorphism at position-670 was associated with IBD in Chinese patients. METHODS: Fifty unrelated Chinese patients with IBD (38 patients with ulcerative colitis and 12 with Crohn's disease) and 124 healthy controls were genotyped for the Fas-670 polymorphism by PCR-restriction fragment length polymorphism method. The PCR product was digested by Mva I restriction enzyme. RESULTS: Distribution of the Fas-670 gene polymorphism was 33% for the AA genotype, 52% for the AG genotype and 15% for the GG genotype in 124 healthy subjects. In patients with IBD, 30% was for the AA genotype, 42% for the AG genotype and 28% for the GG genotype respectively. However, there was no significant difference in the genotype (P = 0.1498), allele frequencies (P = 0.3198) and carriage frequencies (P = 0.4133) between healthy controls and IBD patients. Furthermore, we did not find any difference between the left-sided colitis and total colitis (P = 0.8242). CONCLUSION: Fas-670 polymorphism is not associated with IBD in Chinese patients.

Adult↗
PubMed2005

Graphite powder and multiwalled carbon nanotubes chemically modified with 4-nitrobenzylamine.

We demonstrate that graphite powder and multiwalled carbon nanotubes (MWCNTs) can be derivatised by 4-nitrobenzylamine (4-NBA) simply by stirring the graphite powder or MWCNTs in a solution of acetonitrile containing 10 mM 4-NBA. We propose that 4-NBA partially intercalates at localised edge-plane or edge-plane-like defect sites and this hypothesis with a range of experimental data provided by electrochemistry in both aqueous and nonaqueous media, electron microscopy and X-ray powder diffraction.

Journal Article↗
PubMed2005

Fabrication of ultrathin films with large third-order nonlinear optical properties.

An ultrathin composite film containing anionic Ag-His complexes (His: L-Histidine) and oppositely charged BH-PPV was fabricated by means of the electrostatic layer-by-layer self-assembly technique. UV/Vis spectra showed a continuous deposition process of Ag-His complexes and BH-PPV. The film structure was characterized by using small-angle X-ray diffraction, AFM, and SEM. The nonlinear optical properties of the ultrathin film were studied by using the Z-scan technique with a laser duration of 8 ns at a wavelength of 532 nm. The film sample exhibited a strong nonlinear saturated absorption, with an alpha2 value of -3.9 x 10(-5) mW(-1) and a self-defocusing effect with an n2 value of -4.78 x 10 (-12) m2W(-1).

Journal Article↗
PubMed2005

The interaction of the SARS coronavirus non-structural protein 10 with the cellular oxido-reductase system causes an extensive cytopathic effect.

The pathological mechanism of SARS-CoV infection was investigated. The gene for the SARS-CoV non-structural protein 10, which is located in the open reading frame of pp1a/pp1ab gene, was synthesized and used to screen for the specific cellular gene coding for the protein interacting with this nsp10 protein in a human embryo lung cDNA library using a yeast trap method. The results indicated that apart from the two subunits of cellular RNA polymerase complex, BTF3 and ATF5, this nsp10 protein was also able to interact specifically with the NADH 4L subunit and cytochrome oxidase II. Further study revealed that the activity of the NADH-cytochrome was altered and the inner mitochondrial membrane was depolarized in the transfected human embryo lung fibroblast by the nsp10 protein gene. The cytopathic effect of the Coronavirus 229E strain appeared more extensive in these cells than in the control cells.

Cell Line↗
PubMed2005

Positive association of heparanase expression with tumor invasion and lymphatic metastasis in gastric carcinoma.

Tumor invasion and metastasis are the most common causes of death in gastric carcinoma. Human heparanase influences tumor invasiveness and angiogenesis. Analysis of its expression in gastric carcinoma has been hindered by our inability to procure pure cancer cells from heterogeneous tissue. In the present study, we analyzed heparanase expression in human primary and metastatic gastric carcinoma cells as well as in paired normal gastric epithelial cells by laser capture microdissection coupled with reverse transcription-polymerase chain reaction (RT-PCR). Tumor tissues, metastatic lymph nodes, and apparently uninvolved normal gastric tissues were collected from 30 patients who had undergone gastrectomy with radical lymph node dissection for gastric carcinoma without preoperative treatment. Bulk tissues and laser capture microdissected cell groups were separately subjected to RT-PCR analysis with heparanase-specific primers. For bulk tissues, heparanase-specific transcripts were detectable in all primary tumor tissues, metastatic lymph nodes, and almost all matching normal tissues. RT-PCR analysis after laser capture microdissection showed no detectable heparanase expression in matching normal epithelial cell groups. Of the laser capture microdissected primary gastric carcinoma cells, 47% (14/30) were heparanase positive. Expression was closely associated with greater tumor invasiveness, including Borrmann gross type and depth of wall infiltration. For metastatic cell groups dissected from lymph nodes, 95% showed clear heparanase expression. Furthermore, the extent of lymphatic spread was directly correlated to heparanase expression at the primary site. In conclusion, laser capture microdissection coupled with RT-PCR is a reliable approach for molecular analysis of heparanase expression in gastric carcinoma. Heparanase may facilitate invasion and metastasis of gastric carcinoma cells.

Adult↗
PubMed2005

Effects of simvastatin on the expression of intercellular adhesion molecule-1 mRNA in neonatal brain with hypoxic-ischemic damage.

The goal of this paper is to report on the study of the mechanism of neural damage in neonatal cerebral cortex and hippocampus when hypoxic-ischemic brain damage (HIBD) occurs and the neural protective effects of simvastatin. One hundred forty-four 7-day-old SD rats of were randomly divided into four groups, i.e., sham operation group (sham group), normal saline control group (HIBD group), citicoline control group (CDPC group), and simvastatin-treated group. Each group was divided into six time points (0 h, 12 h, 24 h, 48 h, 72 h, and 7 days after HIBD or sham operation), and each time point included six rats. The expression of intercellular adhesion molecule-1 (ICAM-1) mRNA was determined semiquantitively by reverse transcription polymerase chain reaction (RT-PCR) in the cortex and hippocampus of neonatal rats at different times to determine the differences. The expression of ICAM-1 mRNA rose obviously 12 h after HIBD in the ischemic hemisphere, peaked at 24 h, and then decreased gradually. There was a remarkably lower expression in the CDPC group and simvastatin group compared with the HIBD group at 12 h, 24 h, 48 h, and 72 h. At 7 days, there was no significant difference between the simvastatin group and the sham group (P > 0.05), and at 72 h, simvastatin down-regulated the expression of ICAM-1 mRNA in cortex significantly more than did citicoline (P < 0.05). Both simvastatin and CDPC can relieve the damages of the brain in rats with HIBD. The protective mechanisms of simvastatin and citicoline are associated with their regulative effect on ICAM-1, and simvastatin is superior to citicoline.

Animals↗
PubMed2005

[Study on effect of radix astragali on injury of cerebral cortex in neonatal rats after hypoxia/ischemia brain damage].

OBJECTIVE: To study the mechanism of injury of cortical nerve cell in the newborn with hypoxia/ischemia brain damage (HIBD), and the neuroprotective effect of Radix Astragali (RA). METHODS: Neonatal HIBD model rats were established and divided into the sham group, the model group and the RA group. Brain of rats obtained at different time points after HIBD to conduct histopathological examination, neuron death rate count, as well as determination of caspase-3 (cysteinyl aspartate-specific proteinase-3) protein mRNA expression in cerebral cortex by immunohistochemistry, semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) respectively. RESULTS: In the model group, caspase-3 mRNA and protein showed an increase at 6 hrs, reached the peak at 24 hrs, and decreased at 48 hrs after HIBD, on the 5th and 7th day restored to baseline level. After being treated by RA, the neuron death rate of ligated side was obviously reduced, caspase-3 mRNA and protein expression peak value decreased by 45% (mRNA) and 40% - 43% (protein). CONCLUSION: RA shows markedly neuron protection in immature brain cortex after HIBD, which is related with the inhibition on caspase-3 expression.

Animals↗
PubMed2005

[Animal and clinical studies on rectal administration of a mixed solution of ibuprofen and diazepam].

OBJECTIVE: Seizure is a common emergency in children with complicated pathogeny. Seizures are usually caused by complicated etiology and fever and febrile seizure are the commonest causes. Repeated and permanent seizures can damage the brain. So it is important to take active and effective measures to control seizure and high fever. Because most seizures and fever take place at home or out of hospital and it is difficult to administer drugs intravenously, it is important to explore an easy, safe, quick and effective way to control and prevent both seizure and fever. The present study aimed to explore the efficacy and safety of rectal administration of mixed ibuprofen and diazepam (IBU-DZP) solution. METHODS: (1) Animal study on the pharmacokinetics in rabbits and pharmacodynamics in rats after rectal administration with the mixed solution and on the irritability of the mixed solution to rectum. (2) Clinical study: Pharmacokinetics of the mixed solution in children after rectal administration were investigated. RESULTS: (1) Animal study: IBU and DZP were both rapidly absorbed from rectum with a peak blood level of (11.7 +/- 1.2) min and (9.4 +/- 2.7) min in rabbits, respectively. The mixed solution could effectively prevent the severity of seizures induced by pentetrazole and significantly suppressed fever induced by yeast. There were no remarkable pathological changes in rectal tissues after repeated rectal administration of the mixed solution. (2) Clinical study: IBU and DZP rapidly reached their peak blood levels at about 30 min and 15 min respectively after rectal administration to the children. The peak values were (57.8 +/- 7.9) mg/L and (450.1 +/- 158.7) microg/L, respectively. In fact, both of them reached levels that were much higher than their therapeutic levels in serum just at 5 min after administration, their blood levels were (41.4 +/- 5.5) mg/L and (321.8 +/- 53.9) microg/L, respectively. CONCLUSIONS: IBU-DZP mixed solution administered rectally is an easy, safe, quick and effective way to control and prevent both seizure and fever.

Administration, Rectal↗
PubMed2005

[Prospective clinical study on serum immunity in IgG-antibodies positive patients convalescent from severe acute respiratory syndrome].

OBJECTIVE: To investigate the serum immunological characteristics in patients convalescent from severe acute respiratory syndrome (SARS). METHODS: In the 1 st, 3 rd, 6 th month after their discharge, eg. SARS-IgG, T cell subsets, blood routine, and the blood biochemistry were systemically determined in SARS convalescent patients. RESULTS: The SARS-antibodies could be used as the diagnostic evidence. During the 6 months after discharge, the titers of SARS-antibodies were high, but they lowered along with passage of time. At the first recheck, the CD4(+) lymphocyte count was lower than normal level in 55.9% of patients, the CD3(+) lymphocyte count was lower than normal level in 31.2% of patients, and the CD8(+) lymphocyte count was lower than normal level in 14.0% of patients. At the second recheck, the levels of T cell subsets recovered to normal level in the most patients. CONCLUSION: T cell subsets, and the number of leukocyte are abnormal in some patients convalescent from SARS. All the indexes examined recover to normal levels half year after discharge. Therefore, it is necessary to follow up the changes in the levels of SARS-antibodies.

Adolescent↗
PubMed2005

Linkage disequilibrium and haplotype analysis of two single nucleotide polymorphisms in STK15 in Chinese.

STK15 (Serine/Threonine protein kinase 15) is a serine/threonine kinase encoding gene, whose overexpression in mammalian cells leads to centrosome amplification, chromosomal instability, and oncogenic transformation. 91A-->T, a single nucleotide polymorphism (SNP) in exon 3 of STK15, has recently been shown to be associated with human cancer susceptibility. Within exon 3 of STK15, there are three nonsynonymous SNPs: 91 A-->T, 169G-->A and 311C-->T. We have determined STK15 genotypes and haplotypes composed of 91A-->T and 169G-->A by PCR-RFLP in a randomly sampled cohort of 193 normal individuals from Northeast China. DNA samples from all individuals were subjected to first round of PCR using a pair of specific primers. For the subsequent nested PCR,a mismatch forward primer, which could introduce an EcoR I restriction site to the 91A allele, was included. The nested PCR products were digested with the restriction endonucleases EcoRI and AccII. The double restriction digests were separated by polyacrylamide gel electrophoresis. Three haplotypes,91A-169G, 91T-169A and 91T-169G, were detected and their frequencies were 68.65%, 10.88% and 20.47%, respectively. Six genotypes composed of the above three haplotypes were found,and their frequencies were 91A-169G/91 A-169G (46.11%), 91A-169G/91 T-169A (14.51%), 91A-169G/91T-169G (30.57%), 91T-169G/91T-169G (3.11%), 91T-169G/91T-169A (4.15%), 91T-169A/91T-169A (1.55%). Whereas no 91A-169A haplotype was detected in all individuals examined in the current study, linkage disequilibrium (LD) between the two SNPs was found.

Alleles↗
PubMed2005

Selection of proteins for human MHC class II presentation.

We investigated the predicted function of proteins eluded from human MHC class II molecules. Peptides that are presented by MHC class II were obtained from the SYFPEITHI database and the corresponding proteins were found in the SWISSPROT database. The functions of these proteins were predicted using the protfun server. Our analysis showed that human proteins presented by MHC class II molecules are likely to be in the cell envelope, be a receptor or involved in immune responses. Presented proteins from bacteria and virus, on the other hand, are more likely to be involved in regulatory functions, translation, transcription as well as replication. These results can lead to better understanding the autoimmunity and the response to infections.

Animals↗
PubMed2005

[Prospective 2-year clinical study of patients with positive IgG-antibodies after recovering from severe acute respiratory syndrome].

OBJECTIVE: To investigate the clinical characteristics of patients recovering from severe acute respiratory syndrome (SARS) during 2 years after the infection. METHODS: The antibody of SARS-IgG, T cell subsets, chest CT, and the pulmonary function were observed in patients 1 month, 3 months, 6 months, and 2 years after convalescence from SARS. RESULTS: In the 20 SARS cases, the level of antibodies was found to descend gradually and slowly during 2 years after convalescence. In the majority of patients T cell subsets recovered completely to normal range at the second examination. At the first re-examination, the rate of abnormal chest CT was 65%, and the main abnormal images included ground glass opacities, thickening of inter-lobular and intra-lobular septa, distorted lobular structure, thickened bronchovascular bundles, thickened pleura, arc shadow under the pleura, bronchiolar dilation, and honey comb like shadows. The rate of abnormal chest CT was 30% at the 4 fourth examination. At the first re-examination, the abnormal rate of KCO was highest, accompanied by abnormalities of forced expiratory volume in 1 second (FEV1) and the diffusing capacity of the lung for carbon monoxide (DLCO), and it began to recover since the third examination. CONCLUSION: The level of SARS-IgG descends slowly, and it may last for a long time. The recovery of chest CT to normal may take a long time. The abnormality in pulmonary functions manifests mainly as impairment of diffusion function. Further research on SARS is necessary.

Adolescent↗
PubMed2004

Assembly and characterization of novel hydrogen-bond-induced nanoscale rods.

A class of bis-urea compounds with perylene bisimide was synthesized and characterized successfully. (1)H NMR and fluorescence spectra confirmed that strong hydrogen-bonding interactions between neighboring urea groups were formed. Interestingly, the photocurrent measurement showed that the self-assembled films of bis-urea compounds could produce steady and rapid anodic photocurrent responses. The TEM images indicated that well-defined nanoscale rods with uniform diameter distribution could be fabricated by self-assembly of hydrogen-bonding interactions and pi-pi stacking interactions of perylene rings.

Journal Article↗
PubMed2004

Mutant carbonic anhydrase 4 impairs pH regulation and causes retinal photoreceptor degeneration.

Retina and retinal pigment epithelium (RPE) belong to the metabolically most active tissues in the human body. Efficient removal of acid load from retina and RPE is a critical function mediated by the choriocapillaris. However, the mechanism by which pH homeostasis is maintained is largely unknown. Here, we show that a functional complex of carbonic anhydrase 4 (CA4) and Na+/bicarbonate co-transporter 1 (NBC1) is specifically expressed in the choriocapillaris and that missense mutations in CA4 linked to autosomal dominant rod-cone dystrophy disrupt NBC1-mediated HCO3- transport. Our results identify a novel pathogenic pathway in which a defect in a functional complex involved in maintaining pH balances, but not expressed in retina or RPE, leads to photoreceptor degeneration. The importance of a functional CA4 for survival of photoreceptors implies that CA inhibitors, which are widely used as medications, particularly in the treatment of glaucoma, may have long-term adverse effects on vision.

Carbonic Anhydrase IV↗