Biomedical subjects

H Chen

Publications and source records attributed to H Chen.

At least 343 records · Page 19Linked to original sources

PubMed2001

[Association of single nucleotide polymorphisms in code region of beta2-adrenoceptor gene with hypertension in Chinese population].

OBJECTIVE: To detect single nucleotide polymorphisms(SNPs) existing in code region of beta(2)-adrenoceptor(2-AR) gene and to investigate association of the identified SNPs with essential hypertension in Chinese Han population. METHODS: Beta(2)-AR gene was sequenced with fluorescent labelling automatic sequencing method in unrelated Chinese Han population from Dabie Mountain in Anhui Province. Genotype of the SNPs were typed with PCR-RFLP method. RESULTS: Two SNPs were identified in length of 774bp, at position + 1053 with G-->C substitution and + 1239 with A-->G substitution respectively. The frequency of genotype of the two SNPs complied well with the Hardy-Weinberg equilibrium in normal group. Distribution of genotype AA, GA, GG of the SNPs at locus + 1239 in hypertension group was significantly different from that in normal group (chi(2) = 6.70, df = 2, P < 0.05). No significant difference was observed in distribution of genotypes of the SNPs at locus + 1053 between the two groups. CONCLUSION: These results indicate that the SNPs at locus + 1239 of beta(2)-AR gene is associated with EH. The SNPs at position + 1053 was not linked to hypertension.

Aged↗

PubMed2001

[Effect of intratracheally administered IL-12 recombinant adenovirus on ovalbumin induced bronchial hyresponsiveness in mouse model].

OBJECTIVE: To assess the effect of intratracheally administered IL-12 recombinant adenovirus (Adm IL-12) on ovalbumin (OVA) induced bronchial hyperresponsiveness in mouse model. METHODS: C57BL/6 mice were sensitized by ovalbumin. Adm IL-12 with the dose of 10(8)pfu/mouse was administered intratracheally before OVA challenge. IL-4, IL-5 and IFN-gamma in BALF, bronchial responsiveness, eosinophil count in peripheral blood and BALF, serum total IgE and specific IgE were measured. RESULTS: There was IL-12 gene expression in the lung tissue after Adm IL-12 administration, concentration of IL-12 in sera and BALF were (540 +/- 60) U/ml and (4 700 +/- 800) U/ml respectively, but were unable to be detected in control group (P < 0.01). Compared with the control group, there were significantly lower levels of IL-4 [(3.5 +/- 2.0) ng/ml vs (85.0 +/- 25.0) ng/ml] (t = 27.97, P < 0.01) and IL-5 [(6.5 +/- 4.5) ng/ml vs (54.0 +/- 14.0) ng/ml], (t = 7.92, P < 0.01) in BALF, accompanying with a higher level of IFN-gamma [(690.0 +/- 32.0) ng/ml vs (12.5 +/- 3.2) ng/ml] (t = 51.6, P < 0.01), lower airway resistance [(360 +/- 30) cm H(2)O vs (810 +/- 50) cm H(2)O] (t = 18.9, P < 0.01) and lower eosinophil counts in both peripheral blood [(0.7 +/- 0.1)% vs (9.2 +/- 0.5)%] (t = 47.1, P < 0.01) and in BALF [(3.5 +/- 0.7) x 10(4)/ml vs (21.6 +/- 4.7) x 10(4)/ml)] (t = 9.33, P < 0.01). However, neither serum total IgE [(65 +/- 9) microgram/ml vs (67 +/- 10) microgram/ml], nor specific IgE [(32 +/- 8) microgram/ml vs (33 +/- 8) microgram/ml] showed significant difference (all P > 0.05). CONCLUSIONS: Intratracheally administered Adm IL-12 inhibits ovalbumin induced airway hyperresponsiveness, which may be an effective approach in the management of antigen induced bronchial asthma.

Adenoviridae↗

PubMed2001

A case of left inferior vena cava.

A case of left inferior vena cava (IVC) was found in a 72-year-old male cadaver during student dissection practice in 1999 at Gifu University School of Medicine. It was formed by junction of the left and right common iliac veins at the lower left corner of the 5th lumbar vertebra. This IVC (15-mm caliber) ascended 82 mm along the left side of the abdominal aorta dorsally to the ureter. Receiving the left renal vein, it became 21 mm in caliber and ran obliquely upward for 43 mm across the abdominal aorta. As soon as it received two right renal veins at the level of the 2nd lumbar vertebra, the IVC (25-mm caliber) turned directly above. The present case belongs to Type C of the classification of McClure and Butler (1925), which is based on the combinations of the left and right IVCs, and on their location relative to the ureters. The present case also belongs to Type 1 of the classification of Yoshida et al. (1981). We consider that left IVC in the present case is mainly caused by disappearance of the right supracardinal vein and persistence of the left one during the embryological development of the IVC.

Aged↗

PubMed2001

Animal study on lung injury caused by simulant segmented shock waves.

OBJECTIVE: To study the lung injury caused by segmented shock waves. METHODS: A total of 60 rabbits and 20 rats were used in this study. The process of transmission of shock waves was divided into three phases, i.e., the recompression phase (RP), the decompression phase (DP) and the underpressure phase (UP). And the recompression wave (RW), the decompression wave (DW) a nd the underpressure wave (UW) simulated the three phases, respectively, generated by the equipment designed by us. The RW test, DW test and UW test were respectively applied to the animals. And lung injuries caused by segmented shock waves were discussed. RESULTS: Under the experimental conditions, the RW did not cause obvious lung injury, but the DW could cause different severities of lung injuries. The greater the decompression ranged and the shorter the decompression duration was adopted, the more severe the lung injury was observed. The UW, to some extent, could cause obvious lung injury. CONCLUSIONS: It suggests that lung injury under shock waves probably occurs during the DP primarily. It probably does not cause direct obvious lung injury during the RP, but significantly influences the capability of causing lung injury during the DP.

Animals↗

PubMed2001

[Seroepidemiological analysis of characteristic of hepatitis B virus in children after vaccination in Ningbo].

OBJECTIVE: To understand the immunity of children in Ningbo after hepatitis B vaccination for seven years and to explore the best time for booster. METHODS: One thousand nine hundred and twenty serum samples from children born in 1982 - 1995 were tested for anti-HBs and HBsAg, using RIA. RESULTS: (1) HBsAg positive rate (2.66%) was lower in vaccinated children born in 1992 - 1995 than those unvaccinated (10.92%) born in 1982 - 1995. HBsAg positive rate had a drop of 75.71% (chi(2) = 22.91, P < 0.0001). (2) Anti-HBs positive rates (65.95%) in vaccinated children was much higher than that in unvaccinated children (41.03%) (chi(2) = 113.67, P < 0.0001). (3) It also showed that children's positive rate of HBsAg increased and anti-HBs dropped after 5 - 7 years of vaccination. CONCLUSION: After immunization of hepatitis B vaccine for 7 years, high immunity and low infection rate of HB in children it appeared in Ningbo. However it is necessary to further study the reason causing the increase of HBsAg positive rate and/or deerease of anti-HBs positive rate, and the suitable time frame of boostering, after 4 or 5 years of primary vaccination.

China↗

PubMed2001

[GATA-2 gene expression in leukemia patients and its significance].

OBJECTIVE: To investigate GATA-2 gene expression in leukemia patients and its clinical significance. METHODS: GATA-2 gene transcripts were detected by reverse transcriptase polymerase chain reaction (RT-PCR), and bcr/abl or PML/RAR alpha transcripts were detected in patients with chronic myeloid leukemia (CML) and acute promyelocytic leukemia (APL), respectively. RESULTS: The GATA-2 transcripts were revealed in 93% of acute myeloid leukemia (AML), in 70% of acute lymphoblastic leukemia (ALL), and 83% of CML patients, but not in normal bone marrow and peripheral blood cells. GATA-2 expression in remission patients was similar to newly diagnosed or relapsed patients. In post-transplantation patients, GATA-2 expression was significantly decreased. In these cases GATA-2 transcripts could be detected with bcr/abl fusion gene disappeared in 2 of 12 CML, whereas neither GATA-2 nor PML/RARalpha transcripts could be detected in APL. CONCLUSION: GATA-2 transcripts was highly expressed in leukemia patients and had no change in remission but significantly decreased in post-transplantation patients. Detection of GATA-2 expression would give information about the residual leukemia stem cells.

Bone Marrow Cells↗

PubMed2001

[In vitro study of the killing activities on H-2(d) murine normal and tumor cells by Ly49A gene transfected lymphocytes].

OBJECTIVE: To observe the killing activities of Ly49A gene transfected lymphocytes of C57BL/6 mice to normal and tumor cells of BALB/c mice. METHODS: pLXSN-Ly49A retrovirus vector was constructed and packaged with PA317 cell line. The lymphocytes of C57BL/6 mice were transfected by culture with virus producing PA317 cells. The Ly49A expression rate on the transfected lymphocytes was detected by flow cytometry and the killing activities of the transfected lymphocytes to normal and tumor cells of BALB/c mice were assayed by MTT method. RESULTS: The Ly49A expression rates of C57BL/6 mice lymphocytes transfected with pLXSN-Ly49A for 24 hours, of those transfected with pLXSN and nontransfected control were (46.67 +/- 0.35)%, (18.73 +/- 0.85)%, and (19.60 +/- 0.27)%, respectively. The killing activity of the transfected lymphocytes to 4T(1) tumor cells remained almost the same as that of the control (P > 0.05), but to normal fibroblasts decreased sharply (inhibiting rate 22% - 25%). CONCLUSION: The Ly49A transfected C57BL/6 mice lymphocytes could kill BALB/c mice tumor cells as effectively as the control did, but the activity decreased sharply to normal BALB/c mice cells, which would be instructive for resolving graft versus host disease after allogeneic bone marrow transplantation.

Animals↗

PubMed2001

[Influence of chemotherapy on hematopoietic microenvironment and effect of autologous bone marrow stromal cell infusion on the recovery of hematopoiesis after chemotherapy].

OBJECTIVE: To observe the influence of chemotherapy on hematopoietic progenitor cells (HPC) and hematopoietic microenvironment (HME). To observe whether intravenous infusion of autologous bone marrow stromal cells (ABMSC) expanded in vitro can improve the hematopoietic function. METHODS: Cultures of CFU-GM, BFU-E, CFU-E and stromal progenitor cells (CFU-F) from normal control and chemotherapeutic patients were performed. The stromal function was analyzed by the assessment of the area of flask surface covered by stromal cells (ASSC) and the time when stromal cells reach confluence (TC). The recovery of hematopoietic function in short term chemotherapy group and long term chemotherapy, with or without ABMSC infusion (1.1 - 8.7) x 10(8) post chemotherapy groups was observed. RESULTS: The yields of CFU-GM, BFU-E, CFU-E and CFU-F in long term chemotherapy group were significantly lower than that in normal group or in short term chemotherapy group. There was no significant difference among three groups in the ASSC and TC. In long term chemotherapy group, the yields of CFU-GM, CFU-E, BFU-E and CFU-F after chemotherapy with BMSC infusion were significantly higher than that without BMSC infusion. In long term chemotherapy group, the lowest value of white blood cell (WBC) and platelet after chemotherapy with BMSC infusion was significantly higher than that without BMSC infusion. The times for WBC and platelets recovered to normal were significantly shorter in BMSC group than in without BMSC. No adverse reaction was observed with ABMSC infusion. CONCLUSION: Long term chemotherapy results in severe impairment in HPC and mesenchymal progenitor cell (MPC), but has no obvious influence on the in vitro BMSC confluent layer formation. Intravenous infusion of expanded ABMSC can accelerate the recovery of hematopoiesis after chemotherapy.

Adolescent↗

PubMed2001

[Invasive rhinocerebral aspergillosis occurred during myelosuppressive phase after chemotherapy: a case report and literature review].

OBJECTIVE: To report a case of invasive rhinocerebral aspergillosis (IRA) during myelosuppressive phase after chemotherapy and the treatment outcome. METHODS: A patient with acute non-lymphoblastic leukemia (M(2a)) occurred IRA during myelosuppressive phase after chemotherapy and was treated with amphotericin B (AmB, including AmB-L), garlicin, 5-flucytosine (5-FC), fluconazole, itraconazole, ketoconazole, econazole and griseofulvin with twice of cerebrotomy lesion resections and cerebral decompressions. RESULTS: Though the survival time of this patient is a little longer than the others, she finally died of uncontrolled infection. CONCLUSION: For most of the IRA, there remains no effective treatment. The best treatment is AmB in combination with surgical excision.

Adult↗

PubMed2001

[A clinical study of haploidentical transplantation using granulocyte colony-stimulating factor stimulating donor bone marrow].

OBJECTIVE: To explore the effects of reducing the incidence of severe acute graft-versus-host disease (GVHD) and improving the disease free survival(DFS) in haploidentical donor transplantation by granlocyte colony-stimulating factor (G-CSF) administration to donor before harvesting and a number of immunosuppresants added to host. METHODS: Thirteen patients with leukemia received allo-bone marrow transplantation (BMT) from two or three HLA loci mismatched related donor (haploidentical group). The clinical outcomes of the bone marrow transplantion were compared with thase of 13 consecutive HLA identical sibling transplantion (identical group). In haploidentical donor BMT, the donors of patients were given G-CSF (Lenograstim Chugai) 250 micrograms/day for seven doses prior to marrow harvest. CSA, MTX, ATG and mycophenolate mofetil (MMF) were combined for GVHD prophylaxis. ATG 5 mg/kg/day was infused for 4 days before transplantation and MMF was adminisered from 7th day after. RESULTS: All the patients were engrafted. The median number of CD34+ cells in graft was 6.1 x 10(6)/kg in haploidentical group and 2.5 x 10(6)/kg in identical group (P < 0.01). The median number of CD3+ cells was 50.5 x 10(6)/kg and 47.0 x 10(6)/kg respectively (P > 0.05). All patients had 100% donors hematopoietic cells after transplantation by cytogenetic evidence analysis. Five of the thirteen patients (38.5%) in haploidentical group and three of the thirteen patients(23.1%) in identical group experienced II-IV acute GVHD (P > 0.05). The probability of chronic GVHD was 87.5% in haploidentical group and 67.5% in identical group (P > 0.05), However none in both groups developed extensive cGVHD. The median follow-up duration was 453 days (range 180-690 days) for haploidentical group and 510 days (range 220-810 days) for identical group. In haploidentical group, five patients died from transplant related mortality (3 GVHD, 2 infection), none relapsed and eight patients(61.5%) survive in disease free situation. In identical group, two patients died from transplant related mortality (1 GVHD, 1 infection), two patients died from relapse and nine patients (69.2%) survive in disease free situation. DFS in haploidentical group and in identical group was similar(P > 0.05). CONCLUSION: The transplants from haploidentical donor used in this study is 3 effective and feasible in preventing acute severe GVHD and improving DFS.

Adolescent↗

PubMed2001

[Study on the reversion of drug resistance in human cervical cancer cell lines].

OBJECTIVE: To determine the resistance reversion of mitomycin (MMC) by 3'-Keto-bmt1-val2-cyclosporin (SDZ PSC 833) in human cervical cancer in vitro and in vivo. METHEDS: A xenografted mitomycin resistant mice model of cervical cancer was devolped. The reversion of mitomycin resistance by SDZ PSC 833 (1 or 3 mg/L) was detected from human cervical cancer cell (Hela) and its resistant subline Hela/MMC in vitro and in vivo. Studies in vitro include drug resistance reversion experiment and the changes of morphology. Studies in vivo including tumor volume and tumor related histopathological changes in the autopsied specimen were evaluated by comparing random sections of each group. RESULTS: Nontoxic doses of SDZ PSC 833 could result in almost partial reversion of MMC-resistance of Hela/MMC. In vivo studies also showed SDZ PSC 833 augmented the growth inhibitory effect of mitomycin on Hela/MMC xenografted in nude mice. CONCLUSION: SDZ PSC 833 can overcome mitomycin resistance of Hela/MMC in vitro and in vivo, so SDZ PSC 833 will be a better candidate clinically for reversing multidrug resistance.

Animals↗

PubMed2001

[Effects of IL-8 on neutrophils under fluid shear].

OBJECTIVE: In order to elucidate the effect of IL-8 on neutrophils in a systematic and all-round way, we introduced an important physiological environment of neutrophils, fluid flow, into this study on the changes in some responses of neutrophils to IL-8 and the inter relationship of those responses under the conditions of different patterns of flow field. METHODS: After using IL-8 and steady flow or sinusoidal-oscillate fluid shear rate simultaneously acting on separated neutrophils for one minute, we measured the expression of CD18, CD62L and the F-actin content with flow cytometry and measured the free calcium concentration inside cells ([Ca2+]i) with the fluorescent stain Fura2/AM using the fluorescent spectrophotometer. RESULTS: It was found that flow shear stress could influence the expression of surface adherence molecule of neutrophils under the action of IL-8. CD18 surface expression increased, and CD62L shed under different flow shear rates, but no significant relationship of these changes with the intensity and pattern of shear stress was noted. On the other hand, the F-actin content in neutrophils under the action of shear stress and IL-8 decreased significantly at low shear rate and then gradually increased at high shear rate (600s -1) to the control value (without shear). The [Ca2+]i concentration under the action of shear stress and IL-8 decreased significantly at low shear rate followed by a quick increase at high shear rate. CONCLUSION: The flow shear stress can influence the activation effects of IL-8 on neutrophils and regulate the magnitude of neutrophil reactions to a great extent, and among these reactions, the change of [Ca2+]i concentration is the most sensitive one and the greatest one. This is in consistence with its second messenger role in the signal transduction pathway. Our results could serve as a basis on which to understand better the mechanism of inflammatory reaction wherein the neutrophils under flow condition of blood are involved.

Actins↗

PubMed2001

[The blood drainage of Langerhans islets with special reference to the functional and clinical significance of pancreatic exocrine part].

OBJECTIVE: This study sought to gain an insight into the blood drainage of Langerhans islets with special reference to the functional and clinical significance of pancreatic exocrine part. METHODS: Observations were carried out in 11 human dead bodies, 40 monkeys, 24 dogs, 62 rats and 24 rabbits by scanning electron microscopy and light microscopy with the technique of retaining microcirculatory dynamic and tissular information in the static specimens, microvascular serial reconstruction, and/or by intravital fluorecence microscopy with FITC-labeled erythrocytes. RESULTS: Three patterns of islet drainage channels drained into different acinar regions with different features and insulo-insular drainage channels observed in the primates were found in this study. The authors suggest that these patterns might be termed as follows: 1. Continuous drainage vessels. All islets possessed these capillary-sized portal vessels which ran a short distance, and then drained into the peri-islet acinar region. 2. Convergent drainage vessels. Some islets possessed one or two, occasionally more, of these portal vessels, which were relatively long and/or thick and drained into the acinar region far away from the islet in the lobule. 3. Translobular drainage vessels. These portal vessels crossed the interlobular septum into an adjacent lobule where sometimes no islet existed, and then drained into the exocrine acinar region 4. Insulo-insular drainage vessels. Some islets in the monkey and human, possessed these vessels which drained into an adjacent small islet through the insulo-insular drainage vessels. CONCLUSION: Langerhans islets possessed the consummate drainage system which drained into different exocrine acinar regions, suggesting that the release of islet hormones is in some way necessary for the exocrine secreting function, and that the reduction of local insular hormone levels in insuloacinar portal circulation and the impairment of insular drainage vessels would be the morphological basis of the pancreatic exocrine pathologic lesion in human diabetes.

Adult↗

PubMed2001

[Recombinant Salmonella typhimurium anticaries vaccine. II. Construction and confirmation of expressing plasmid carrying a region of S. mutans pac gene].

OBJECTIVE: The objective of this study is to construct prokaryotic expressing plasmids carrying A region of S. mutans pac gene. METHODS: The A region of pac gene was amplified by using PCR from plasmid pPC41 containing S. mutans surface protein pac gene. The new expression plasmid was constructed by using A region of pac gene and expressing plasmids pET17-b and directed cloning technique. The recombinant plasmid was identified by agarose gel electrophoresis after it was cut by using BamHI and EcoRV. RESULTS: The expressing plasmid carrying pac gene A region was acquired. CONCLUSION: The recombinant plasmid provides useful experimental materials for further research work.

Dental Caries↗

PubMed2001

[Extraction of residual formaldehyde in polymer complex and high performance liquid chromatographic analysis].

This paper presents a simple and accurate method for analyzing formaldehyde in polymer complex by headspace extraction derivatization and HPLC analysis. The sample preparatio of formaldehyde in polymer complex was based on a simple thermodynamic equilibrium in a closed and thermostat jar, and the gaseous formaldehyde in equilibrium could be absorbed and extracted by the liquid in the bottom of the jar. The formaldehyde was derivatized with 2,4-dinitrophenyl hydrazine before chromatography. The influences of temperature, equilibrium time, sample quantity and geometric form on the extraction efficiency were studied. The extraction and HPLC conditions were optimized. The limit of detection (LOD) was 0.1 mg/kg, and the relative standard deviation (RSD) was below 5%, and the recoveries were between 96%-103%. As a result, this method would meet the demands for analyzing microamounts of residual formaldehyde in polymer complex.

Chromatography, High Pressure Liquid↗

PubMed2001

[Cloning and expression of the envelope glycoprotein gD gene of pseudorabies virus EA strain].

The envelope glycoprotein gD gene of pseudorabies virus Ea strain was cloned via PCR technique. Sequence analysis displayed 98% nucleotide sequence homology and 97% deduced amino acid sequence homology between our cloned gD gene and PRV Rice strain gD gene. The recombinant transfer plasmid pSX35A-gD was obtained by inserting D gene into the baculovirus transfer vector pSX35A with whole-phase promoter cassette, then transfected insect cell Hi5 with linearized AcMNPV-OCC- virus DNA, and formed recombinant baculoviruses AcMNPV-OCC(+)-gD by homologous recombination in insect cell. Recombinant baculoviruses infected insect cell Hi5 after being purified by plaque assay. Both SDS-PAGE and Western-blotting showed glycoprotein gD with a molecular weight of about 47 kD was expressed specifically, product was about 6.2% of total cellular protein, and expressed gD was of immunogenicity.

Animals↗

PubMed2001

[Cloning of trehalose-6-phosphate synthase gene from S. cerevisiae and its plant expression vector construction].

Total RNA, mRNA were isolated from baker's yeast S. cerevisiae, the cDNA was prepared with AMV Reverse Transcriptase from the total mRNA. The gene of trehalose-6-phosphate synthase was cloned from the cDNA with PCR amplification. The gene was sequenced and the results showed that the tpsl gene contains 1507 nucleotides and 99.6% identity with S. cerevisiae. The tps1 gene was constructed on the plant expression vector pBin438.

Base Sequence↗

PubMed2001

[Cloning and sequencing of 16S rRNA gene of Phytoplasma CWB1 strain associated with cactus witches' broom].

A 1.5 kb DNA fragment was amplified in DNA samples extracted from Opuntia salmiana porm showed witches'-broom symptom. The result indicates the existence of phytoplasma associated with this disease and this phytoplasma was designated as CWB1. The amplified fragment was ligated to pGEM-T easy vector and then transformed into JM109 strain of E. coli. Cloned DNA fragments were verified by PCR, restriction endonuclease (EcoRI) digestion and sequence analysis. The result revealed that the 16S rRNA gene of CWB1 consists of 1489 bp and shared 99.7% homology with Faba bean phyllody which belongs to phytoplasma 16S rII-C subgroup. So we can classify this strain into phytoplasma 16S rII-C subgroup.

Cloning, Molecular↗