Biomedical subjects
Publications and source records attributed to J Xu.
According to the typical behaviors from different periods of morphine addicted rat, EEG records were classified into six groups: control, addiction, short term abstinence, long term abstinence, relapse and naloxone. The results indicated that there were typical wave forms in different periods.
OBJECTIVE: To evaluate the accuracy of a three-dimensional (3D) magnetic position sensor system in the quantification of ventricular stroke volumes in a dynamic model. METHODS: A latex balloon model of the left ventricle was suspended in a water bath connected to a pump producing 10 different pulsatile stroke volumes (15-65 ml/beat). Scanning was performed using a 5.0 mHz transducer mounted with a Flock of Birds (FOB) magnetic receiver (GE System Five). The probe was scanned to sweep continuously across and over the balloon volume over 3-7 seconds. Digital loops were stored on magneto-optical disks and reviewed retrospectively using 3D Echopac software (GE) based on Simpson's method and compared with a two-dimensional (2D) biplane area-length method (1/2 L x R) measurements at end systole and end diastole. Both 3D and 2D derived stroke volumes were compared with the reference stroke volume calculated by direct measurement of balloon capacity. RESULTS: There was an improved correlation between 3D stroke volume and reference stroke volume (y = 0.91x + 0.41, r = 0.97, SEE = 2.83 ml, P = 0.0001) compared to 2D stroke volume and reference stroke volume (y = 0.49x + 8.68, r = 0.87, SEE = 3.87 ml, P = 0.0011, difference between 2D and 3D P < 0.003). CONCLUSION: 3D magnetic FOB scanning is practical, accurate and should facilitate assessment of left ventricular function.
OBJECTIVE: To evaluate the clinical applications and limitations of CT virtual endoscopy (CTVE) in the auditory ossicular chain. METHODS: CTVE of the auditory ossicular chain was performed with 1.0 mm collimation at pitch 1.0, bone algorithm, 9.6 cm field of view, and 0.1-0.2 mm reconstruction interval in 40 patients with middle ear diseases. 30 cases were confirmed by surgery. Results were compared with the findings of axial high resolution CT (HRCT) and multiplanar reformation (MPR) images and surgery. RESULTS: The accuracy of CTVE images in detecting ossicular destruction was 92.6%, significantly higher than that of axial HRCT (83.9%) and multiplanar reformation (76.5%) images. CTVE could also clearly reveal the postoperative condition and congenital dysplasia of the auditory ossicular chain. CONCLUSIONS: CTVE can clearly demonstrate a three-dimensional image of the auditory ossicular chain and is useful in evaluating diseases of the ear, especially the auditory ossicles. CTVE could not clearly demonstrate abnormal soft tissue within the tympanic cavity, abnormal changes of the tympanic membrane and tympanic walls, and could be easily influenced by artificial factors.
Hexavalent chromium (Cr (VI)) is reduced intracellularly to Cr (V), Cr (IV) and Cr (III) by ascorbate (Asc), cysteine and glutathione (GSH). These metabolites induce a spectrum of genomic DNA damage resulting in the inhibition of DNA replication. Our previous studies have shown that treatment of DNA with Cr (III) or Cr (VI) plus Asc results in the formation of DNA-Cr-DNA crosslinks (Cr-DDC) and guanine-specific arrests of both prokaryotic and mammalian DNA polymerases. GSH not only acts as a reductant of Cr (VI) but also becomes crosslinked to DNA by Cr, thus, the focus of the present study was to examine the role of GSH in Cr-induced DNA damage and polymerase arrests. Co-incubation of Cr (III) with plasmid DNA in the presence of GSH led to the crosslinking of GSH to DNA. GSH co-treatment with Cr (III) also led to a decrease in the degree of Cr-induced DNA interstrand crosslinks relative to Cr (III) alone, without affecting total Cr DNA binding. DNA polymerase arrests were observed following treatment of DNA with Cr (III) alone, but were markedly reduced when GSH was added to the reaction mixture. Pre-formed polymerase-arresting lesions (Cr-DDC) were not removed by subsequent addition of GSH. Treatment of DNA with Cr (VI), in the presence of GSH, resulted in crosslinking of GSH to DNA, but failed to produce detectable DNA interstrand crosslinks or polymerase arrests. The inhibitory effect of GSH on Cr-induced polymerase arrest was further confirmed in human genomic DNA using quantitative PCR (QPCR) analysis. Treatment of genomic DNA with Cr (III) resulted in a marked inhibition of the amplification of a 1.6 kb target fragment of the p53 gene by Taq polymerase. This was almost completely prevented by co-treatment with GSH and Cr (III). These results indicate that Cr-induced DNA interstrand crosslinks, and not DNA-Cr-GSH crosslinks, are the principal lesions responsible for blocking DNA replication. Moreover, the formation of DNA-Cr-GSH crosslinks may actually preclude the formation of the polymerase arresting lesions.
OBJECTIVE: To establish a mice-model of primary respiratory syncytial virus infection. METHODS: Twelve Balb/c mice (8-12 w) were divided into two groups with three different titers of RSV infection in the experimental group. Mice were anaesthetized with pentobabitone(30 mg/kg) and infected by nasal drip of 0.1 ml of RSV which was harvested from HEP-2 cell culture. Three mice in the control group received sham infection with HEP-2 cell media. Five days later, lungs were removed in aseptic condition. Right lung was weighted and homoginized with MEM(1:10 ratio), then centrifuged at 4 degrees C, 2,000 r/min for 20 minutes. Supernatants were collected for virus isolation and plaque forming assay. Left lung was collected for histopathological and electromicroscopic examination. RESULTS: (1) RSV grew with a characteristic syncytial formation in HEP-2 cells, leading to the fusion of cells with round, elliptic, map or tree like shape. (2) Virus was isolated and detected in the lung tissue in experiment group. (3) There was a positive correlation between RSV titer added and that replicated in the lung. (4) After the eclipse phase, viral replication in the lung reached maximum within 4 and 6 days. The most apparent pathological change was found between day 5 and 8. Mononuclear cell infiltration was presented in the perivascular, peribronchial and in the alveoli spacers. (5) Huge viral replication with its fuzzy coat was detected inside the cytoplasm of the type II alveolar lining cell at high magnification. CONCLUSION: An animal model of RSV infection Balb/c mice was successfully established by nasal inoculation with respiratory syncytial virus.
OBJECTIVE: To explore the relationship between vitamin D receptor (VDR) gene polymorphisms and bone mineral density (BMD) in patients with type 2 diabetes mellitus (DM) and to better understand the pathogenesis of osteoporosis. METHODS: Ninety seven patients with type 2 DM were recruited for this study. BMD was measured by single photon absorptiometry at the lower one third of the nondominant radius and ulna. Polymorphisms of the VDR gene were analyzed by DNA amplification with polymerase chain reaction (PCR) and endonuclease digestion with Bsm I. RESULTS: The respective frequencies of VDR genotypes were BB 18.6%, Bb 27.8% and bb 53.6%. The Z scores of the three groups were -1.57 +/- -0.60, -1.45 +/- -0.67 and -1.41 +/- -0.81, respectively. Although the BMD of the Bb genotype DM patients was higher than that of BB genotype DM patients and lower than that of bb genotype DM patients, there were no significant differences. CONCLUSION: These findings suggest a small influence of VDR gene polymorphism on the BMD of patients with type 2 DM. Further study on the value of VDR genotypes in the pathogenesis of osteoporosis in diabetes mellitus is still needed.
OBJECTIVE: To study the mechanism of thrombosis in systemic lupus erythematosus (SLE) patients with protein C (PC) pathway inhibition by lupus anticoagulant(LA). METHODS: Phosphoethylamine(PE) dependent activated protein C (APC) inhibiting assay (modifed DRVVT) was used to observe the inhibition of APC activity after incubation of IgG from both normal and SLE patients with PE. RESULTS: The activity of anticoagulation of APC was augmented by PE. Proportionally to its concentration, LA could inhibit the PE dependent anticoagulation of APC. The inhibition of LA-IgG on APC in the LA positive SLE patients with thrombosis was stronger than that in LA negative non-thrombosis patients; but IgG has no effect on the APC activity in normal person. CONCLUSION: LA inhibiting the PC pathway by interfering with PE may be the important reason of thrombosis in SLE patients.
OBJECTIVE: To investigate the effect of platelet on procoagulant activity of mononcyte(M). METHODS: The procoagulant activity of M lysates was measured by one stage clotting time assay, the tissue factor (TF) activity and the role of P-selectin were confirmed by specific monoclonal antibodies (McAb). RESULTS: 1. Activated M challenged by lipopolysaccharide(LPS) had augmented procoagulant activity and this effect was blocked by TF McAb. 2. Procoagulant activity of M and activated M increased significantly with the presence of activated platelets. 3. The enhancement effect of activated platelet on the procoagulant activity of M was blocked by P-selectin McAb. CONCLUSION: TF expression of M contributes to the procoagulant activity of Ms and activated platelet enhances the procoagulant activity via P-selectin.
Pot experiment was conducted in greenhouse to determine the effect of boron fertilization on B uptake and utilization by oilseed rape at seedling stage as influenced by soil moisture regime. The results showed that B concentration in shoot and root increased with the increase of soil water content and B fertilization level, while its utilization efficiency(BUE) and mobilization index(BMI) increased with the decrease of soil water content and B application level. Differences in BUE and BMI of test oilseed rape cultivars were significant, i.e., V1 showed higher BUE and BMI than V4 under the same conditions. It is concluded that BUE and B mobility in plant were the major factors responsible for the differences in response of different oilseed rape cultivars to B deficiency.
OBJECTIVE: To evaluate the clinical application of helical CT multiplanar reformation (MPR) three-dimensional reconstruction (3D) and virtual laryngoscopy (CTVL) in laryngeal and hypopharyngeal carcinoma. METHODS: Axial helical CT scans were performed in 22 patients with laryngeal or hypopharyngeal carcinoma, along with MPR, 3D and CTVL. These results were compared with the findings of fiber optic laryngoscopy and surgery. RESULTS: Combining axial and MPR images, both the accuracy in preoperative tumor staging and the diagnosis of metastatic lymph nodes were 95%. MPR demonstrated more information about the extent of tumor than axial images in 23% cases; 3D image displayed clearly the extension of tumor, the vessels and airway from multiple views. The location, size and extent of tumors found in cranio-caudal CTVL corresponded well with that of laryngoscopy, and CTVL demonstrated the relationship between the tumor and vocal cords and anterior commissure by caudo-cranial approach, which was inaccessible to fiber optic laryngoscopy in 3 cases. CONCLUSIONS: Axial images of helical CT clearly demonstrate the location, size and extent of laryngeal and hypopharyngeal carcinoma, while MPR and 3D images are useful in displaying the three-dimensional images and anatomical relation of the tumor. CTVL can clearly display the mucosal surface structures of the larynx and hypopharynx and is a good complementary method of laryngoscopy.
OBJECTIVE: To study the clinicopathologic features of hepatic angiomyolipoma (AML) and to investigate the feasibility of a new antibody-A103 as a diagnostic aid for AML. METHODS: Ten cases of AML were retrieved from hospital records and analyzed morphologically. Immunohistochemistry was performed on paraffin-embedded tissues with a panel of antibodies, including antibody-A103. RESULTS: There were eight women and two men, with ages ranging from 38-58 years (median 45.7). Clinically, nine cases were asymptomatic and found by imaging techniques. None of the patients had associated tuberous sclerosis. All tumors were sharply demarcated from the surrounding liver parenchyma. Histologically they were composed of a heterogeneous mixture of three components: thick-walled blood vessels, spindle or epithelioid smooth muscle cells and adipose tissue. All tumors showed a strong immunoreactivity to A103, HMB-45 and smooth muscle actins. Follow-up information on all 10 cases showed a benign course with no signs of recurrence. CONCLUSIONS: Hepatic AML is a rare mesenchymal tumor of the liver. A103 is a promising marker for a pathologic diagnosis of hepatic AML.
OBJECTIVE: To evaluate the outcome of surgical treatment for congenital coronary artery fistulas (CAF) in 52 patients seen between May 1988 and July 1999. METHODS: Fifty-two patients ranging in age from 9 months 58 years (mean 15.7 +/- 16.4 years) were studied. Thirty-six patients had no other cardiac defects, 9 of those patients were more than 20 years old and presented with symptoms. Only one of 36 patients less than 20 years old had clinical findings before surgery. Sixteen patients had associated cardiac lesions. The site of fistula origin was the right coronary artery in 37 patients (71.2%), and the left coronary artery in 15 patients (28.8%). The sites of CAF drainage were the right ventricle, right atrium, left ventricle, left atrium and pulmonary artery in 22 (42.3%), 16 (30.8%), 6 (11.5%), 3 (5.8%), and 5 (9.6%) patients, respectively. The mean diameter of the fistula in 43 patients with single ostium was 7.34 +/- 4.12 mm. RESULTS: Cardiopulmonary bypass was used in all patients and no patient died. An arteriotomy was made on the anomalous coronary artery and the proximal opening of a fistula was closed within the vessel in 10 patients. Closure of the distal opening of a fistula draining into a cardiac chamber or pulmonary artery was performed in 26 patients. In 16 patients, both the proximal and distal opening were closed. Two and 3 distal opening of a fistula were found in 6 and 3 patients, respectively. No residual shunt was found before patients were discharged from the hospital. Forty patients were followed up for a mean period of 3.14 +/- 1.84 years. The remaining 12 patients could not be contacted during follow-up. No clinical symptoms were found in those patients during follow-up but one patient still presented with ST-T change. CONCLUSION: Early and properly surgical management is safe and effective for congenital coronary fistula.
OBJECTIVE: To provide epidemiological data for revising the diagnostic criteria of neonatal hyperbilirubinemia in China. METHODS: A survey was performed among full-term infants in multiple centers throughout the country. From less than 24 hours after birth, the infants' bilirubin levels were measured every day until the peak level fell to less than 68.4 mumol/L. Auditory brainstem responses were assessed in 56 infants randomly chosen from those with serum bilirubin levels of higher than 220.5 mumol/L. RESULTS: Jaundice in most infants was detected at 2-3 days after birth. The bilirubin level usually reached a peak level of 204 +/- 54.69 mumol/L at 5 days after birth and then fell. Among the 875 infants, the serum bilirubin levels in 34.4% of neonates were higher than 220.5 mumol/L. The mean serum bilirubin level of the infants during the first week after birth varied with geography (P < 0.001) and season (P < 0.001). The serum bilirubin level was significantly associated with gestation age (P < 0.01), delivery method (P < 0.01), weight loss (P < 0.001), and PCV elevation (P < 0.001) during the first three days after birth. CONCLUSIONS: The start time of neonatal jaundice was similar to that reported elsewhere, but the mean peak level in our study was higher than the reported. It is suggested that the diagnostic criteria for neonatal hyperbilirubinemia in China should be strict.
OBJECTIVE: To investigate the factor V Leiden mutation associated with activated protein C resistance (APCR) in Chinese. METHODS: Thirty "normal" individuals and twenty patients with thrombotic disease from Chinese Han Nationality were studied with APTT +/- APC, PCR followed by MnLI restriction enzyme analysis, PCR based direct sequence-specific primers (PCR-SSP) and DNA sequence analysis. RESULTS: In one healthy control, the activated protein C (APC) sensitivity ratio (SR) was found to be significantly lower (0.8) than that in other normal control (> 2.0). This individual was identified to be heterozygous for FV Leiden mutation (Arg506-Gln). His grand-uncle, father, brother and son were also identified to be heterozygous for FV Leiden. The APC resistance was found in 3 other cases of thrombotic diseases, but with no FV Leiden mutation. CONCLUSION: This is the first four generations family case of FV Leiden mutation associated with APCR reported within Chinese ethnic population. It is note-worthy that more FV Leiden or whether other gene defects may be associated with APC resistance and acquired APCR causing thrombosis in Chinese population.
OBJECTIVE: To evaluate the clinical value of transrectal ultrasound (TRUS) examination of the prostate in the diagnosis of prostate cancer (PCA). METHODS: The sonographic and clinical data of 100 patients with PCA were analyzed retrospectively. RESULTS: There was single lesion in 59 patients, diffuse lesion in 17 patients. The size of tumor in 35 patients was < or = 1.5 cm. TRUS in the diagnosis of PCA had an accuracy of 76.0%, specificity of 89.4%, false positive rate of 10.6% and negative predictive value of 88.9%. The level of prostate specific antigen (PSA) increased with the increase in the size of the tumor (P < 0.05). The PSA level of patients with poorly differentiated PCA was significantly higher than that in patients with well differentiated PCA. CONCLUSION: TRUS examination is a convenient procedure for the diagnosis of PCA in its early stage.
OBJECTIVE: To explore the effect of oxLDL on CXC chemokine growth-regulated oncogene alpha (GRO alpha) expression in human endothelial cells and the possible functional significance of the effect. METHODS: LDL was isolated by sequential ultracentrifugation and oxidized to oxLDL. Reverse transcription-polymerase chain reaction with GAPDH as internal standard was applied and CXC chemokine GRO alpha mRNA in endothelial ECV304 cells was examined. ELISA was used to determine GRO alpha protein expression on ECV304 cells surface and in the medium. With static cell adhesion assays, the physiological significance of elevated GRO alpha expression was tested. RESULTS: OxLDL, not LDL, treatment of ECV304 cells significantly induced the expression of GRO alpha mRNA that was not detectable in untreated cells. Induction of expression was first evident at 1 h, became maximal at 2 h, and was substantially decreased by 4 h. In a concentration- and time-dependent manner, oxLDL, and not LDL, induced a significant upregulation of GRO alpha surface expression in ECV304 cells that was at a barely detectable level in unstimulated ECV304 cells. GRO alpha protein in the medium did not change significantly. Exposure of ECV304 cells to 40 micrograms protein/ml oxLDL for 24 h resulted in a marked increase in the number of U937 cells bound to ECV304 cells and antibodies to GRO alpha inhibited adhesion. CONCLUSION: OxLDL functionally upregulated GRO alpha expression in endothelial cells.
The fusion gene of BPI23 and human Fc gamma 1 was obtained by PCR method, and the expression plasmid was constructed to express recombinant BPI23-Fc gamma 1 fusion protein in CHO cells. After transfection with the plasmid and selection by methotrexate, the cell lines expressing the fusion protein were obtained. The recombinant protein was purified using cation-exchange chromatography and its bioactivity was proved with bactericidal assays.
The effects of seed coating formulation (SCF) of Atractylodes macrocephala Koidz. on seedling in two experimental plots located in Hangzhou and Jiande were studied, and desinged with L9(3(4)) orthogonal comparison. The results showed that the SCF with paclobutrazol (pp333) had a significant effect on the rate of germination at Hangzhou plot, all factors had no significant effects on length of seedlings in both plots, and both atonik (sodium O-nitrophenolate) and PP333 on the fresh or dry seedling weight had significant effects.