Search PubMed⌕ Search

Biomedical subjects

L Chen

Publications and source records attributed to L Chen.

At least 577 records · Page 32Linked to original sources
PubMed1999

[Pregnancy induced hypertension complicated acute disseminated intravascular coagulation: clinical analysis of 26 cases].

OBJECTIVE: To determine the relationship between pregnancy induced hypertension (PIH) and acute disseminated intravascular coagulation (DIC). METHODS: 26 cases with PIH complicated acute DIC were analyzed retrospectively in five hospitals of Xi'an from 1980 to 1997. RESULTS: (1) In 26 patients with PIH complicated acute DIC, 7 cases died (26.92%), while 17 neonates died (58.62%) in 29 neonates (3 cases were twin pregnancy). Cesarean section and hysterectomy were performed on 7 cases respectively, including 4 cases underwent both of them. (2) The causative factors of PIH complicated acute DIC included placental abruption (7 cases), amniotic fluid embolism (4 cases), eclamptic seizure (4 cases), surgical injury (7 cases) and bleeding (4 cases). 7 cases induced by placental abruption were all cured, 4 cases induced by amniotic fluid embolism all died. CONCLUSION: There are close relationship between PIH and DIC, PIH complicated acute DIC is the major cause of maternal and perinatal mortality, special attention should be paid on preventing DIC for PIH.

Abruptio Placentae↗
PubMed1999

[Detection of antineutrophil cytoplasmic autoantibodies in pregnancy induced hypertension and its clinical significance].

OBJECTIVE: To explore the level of antineutrophil cytoplasmic autoantibodies (ANCA) in patients with pregnancy induced hypertension (PIH) and its clinical significance. METHOD: 37 cases with PIH and 39 non-PIH pregnancy were studied for ANCA by indirect immunflourscence. RESULTS: ANCA positive rates were 33.3%, 88.9% and 86.4% in mild, moderate, severe PIH, respectively, and most of them were c-ANCA. The positive rate was only 13.2% in non-PIH control, significantly lower than those in PIH (P < 0.001). CONCLUSION: ANCA may be one of the causes for endothelial cell damage and a predicting marker in PIH.

Adult↗
PubMed1999

[Effect of microinjection of taurine into anterior hypothalamic area on blood pressure in rats].

The effect of taurine in anterior hypothalamic area (AHA) on blood pressure was investigated by means of microinjection and spectrophotofluorometry. The results are as follows. (1) Taurine microinjected into AHA decreased blood pressure markedly. (2) The depressor response of taurine in AHA could be antagonized by propranolol, but not by phentolamine. (3) After microinjection of taurine into AHA, the content of norepinephrine in hypothalamus increased significantly. The above results suggest that taurine in AHA attenuates blood pressure by increasing the content of norepinephrine, probably mediated by beta-adrenergic receptor.

Adrenergic beta-Antagonists↗
PubMed1999

[Effect of beta-endorphin on plasma sialic acid level in rats and the relationship with the immune function].

With the use of beta-EP microinjection into the central nervous system, spectrophotometrical analysis and immunochemical method we studied the effect of beta-Endorphin (beta-EP) on plasma sialic acid (SA) level. The results indicate: (1) The plasma SA level was significantly decreased after microinjection of beta-EP into the lateral ventricle (LV); (2) When beta-EP was microinjection into nucleus arcuatus (ARC), the plasma SA level was significantly decreased (P < 0.05). This effect can be blocked by i.v. atropine or vagotomy; (3) Microinjection of beta-EP into ARC can cause the increase of CD3, CD4 and CD4/CD8, while CD8 was decreased. The above results suggest that the possible mechanism underlying the decrease of plasma SA level is mediated by cholinergic muscarinic receptor, and the cellular immune function is enhanced.

Animals↗
PubMed1999

[Analysis of the treatment of 82 patients with inhalation injury].

OBJECTIVE: To learn the experiences and improve the treatment of inhalation injury. METHODS: Causes of death and treatment effects were analyzed in a group of 82 patients admitted from January 1994 to April 1998. RESULTS: Among the 82 patients, 33 patients were cured, 11 patients were improved and 38 patients died. Among the 38 cases of death, 24 patients died directly of inhalation injury and 14 patients died of other complications. CONCLUSION: The major causes of death of the patients with inhalation injury are acute intoxication, asphyxia, and ARDS(acute respiratory distress syndrome). For the treatment, tracheostomy should be carried out the earlier the better. Moistening of the airway and lavage may be effective in preventing lung infection, facilitating the ejection of phlegm and necrotic mucosa. The amount of fluid infusion should appropriately be increased and this will not lead to lung edema. Administration of corticol hormone in the early stage for a short period will also result in positive effects.

Administration, Inhalation↗
PubMed1999

Studies on renin-2 gene in transgenic rats.

OBJECTIVE: To determine the function of, in vivo, renin and its role in the pathogenesis of hypertension. METHODS: A renin-2 gene restriction map was constructed by endonuclease digestion and Southern blotting hybridization. Transgenic rats were produced via microinjection method. RESULTS: The 24 kb fragments containing mouse full-length ren-2 and its flanking sequence were cleaved by single enzymes (EcoR I, Kpn I and BamH I) and combined enzymes (EcoR I/Kpn I, Kpn I/BamH I and BamH I/EcoR I), respectively. The digests were electrophoresed in 0.8% agarose plates and transferred onto NC membranes. Radioactive 735 bp and 1400 bp probes obtained from half and full-length renin-1 cDNA were used in southern blotting hybridization. According to the electrophoresis and hybridization patterns, a ren-2 restriction map was constructed. 1603 fertilized rat ova after injection with purified 24 kb renin-2 gene were implanted into the oviducts of 81 pseudopregnant recipients in about 20 ova per female rat. 306 progenies were obtained from 50 foster mothers (average of pregnancies was 56.6%). 248 survived pups were identified by PCR analysis and Southern hybridization, and eight positive rats were found to be the transgenic rats (founder, F). All of them carried long fragments (24 kb) of renin-2 gene with normal blood pressure. Preliminary breeding and screening were carried out in the founder. Total survival pups (17.8%) and overall efficiencies (1%) were harvested as the same as those reported in the literatures. A systemic observation and the problems occurred during production of transgenic rats were also described besides the technique procedure used in this study. CONCLUSIONS: Mapping of full-length murine ren-2 can be used in investigation of the structure and function of the gene. The results denoted that the ren-2 transgenic rats were successfully established in this study and the technique used in the production of transgenic rats was proved to be valid in leading to wide-spread application of transgenic technique to many other related researches.

Animals↗
PubMed1999

Combination of all-trans retinoic acid with butyric acid and its prodrugs markedly enhancing differentiation of human acute promyelocytic leukemia NB4 cells.

OBJECTIVE: To use NB4, an authentic human acute promyelocytic leukemia cell line, as well as the marrow cells from patients with acute promyelocytic leukemia (APL), containing the PML/RAR alpha fusion gene and fused protein to examine the growth inhibition and cytodifferentiation induced by all-trans retinoic acid (ATRA), butyric acid (BA) and its prodrug tributyrin (TB) either as a single agent or in combinations. METHODS: NB4 and APL cells were cultured in presence of ATRA, BA and TB respectively either as a single agent or in combinations at various concentration ratio. Cell growth was measured and myeloid differentiation was determined by morphology and the percentage of positive nitroblue tetrazolium reduction (NBT) on consecutive days over the whole process of culture. RESULTS: NB4 cells can be induced by ATRA alone and synergistically induced by the combinations of BA or TB with ATRA to differentiate. The synergy was reflected by a remarkable decrease in the effective concentration of ATRA required in the combinations in comparison with it as a sole agent. The combinations also shortened the time for the cells to reach the same level of maturation as that needed for ATRA alone. The potentiation on ATRA-induced differentiation of NB4 cells seemed depending on an appropriate concentration ratio of each inducer in the combinations and the time of action. A preliminary result of in vitro induction of primarily cultured leukemic cells from APL patients by the combined inducers was promising. CONCLUSION: The combinations of ATRA with BA or TB at an appropriate ratio may improve the clinical outcome of differentiation therapy for APL patients.

Butyric Acid↗
PubMed1999

Interrelation between nitric oxide and endothelin-1 in an experimental acute hypoxia in rats and its intervention.

OBJECTIVES: To study the interrelation between nitric oxide (NO) and endothelin-1 (ET1) in experimental acute hypoxic rats, and to evaluate the mechanism of acute hypoxic pulmonary hypertension affected by NO and ET1 and its intervention. METHODS: Nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemical staining method, Griess biochemical assay and radioimmune assay were applied to investigate the changes of nitric oxide syntheses (NOS), NO and ET1 in normal, hypoxic, and L-Arginine (L-Arg) and dexamethasone treated hypoxic rats. RESULTS: In normal rats, the NOS stain was localized in pulmonary vascular endothelium, and in the hypoxic rats, the activity of NOS was significantly lower. The level of plasma NO was significantly lower during acute hypoxia, but L-Arg as well as dexamethasone could prevent the drop of plasma NO. The level of plasma ET1 rose up significantly in the acute hypoxic rats, but after L-Arg therapy, it was significantly reduced, however, dexamethasone could not affect plasma ET1. The level of plasma cyclic guanosine monophosphate (cGMP) was significantly lower in the acute hypoxic rats, and L-Arg could prevent the drop of plasma cGMP, but dexamethasone could not prevent the drop of plasma cGMP. CONCLUSIONS: NO and ET1 may modulate hypoxic pulmonary hypertension and acute hypoxia can result in acute hypoxic pulmonary hypertension. L-Arg can reverse the acute hypoxic pulmonary hypertension. Further study is needed if dexamethasone is beneficial in acute hypoxic diseases. NO may play an important role in physiology of the lung and acute hypoxic diseases.

Animals↗
PubMed1999

[Study on G487A mutation of the glucose-6-phosphate dehydrogenase gene].

OBJECTIVE: In order to reveal the molecular evolution and ethnic origin and immigration, on the basis of G6PD G487A mutation, and estimate the incidence of the mutation in Bai, Dai, and Han people in Yunnan and Guangxi. METHOD: G6PD deficient individuals were studied by using PCR-RE, PCR-SSCP and DNA sequencing. RESULTS: The G487A mutation in Bai and Dai people was identified for the first time and its relative incidences were 6/66 and 1/52, respectively. The individuals of G6PD G487A mutation showed the features of G6PD clinic type III. No G487A was found in Han people in Guangxi(0/46). CONCLUSION: The G6PD G487A mutation revealed in some ethnic groups of China implies that different national minorities of Chinese may be origined from a common ancestor.

Asian People↗
PubMed1999

[Optic nerve neuropathy by ethambutol toxicity].

OBJECTIVE: To investigate the clinical manifestations, treatment and prevention of optic nerve damage by ethambutol toxicity. METHODS: Retrospective analysis was done on 17 patients of tuberculosis who had been treated with ethambutol and shown ocular symptoms. RESULTS: Changes in visual acuity, fundal appearance, visual field and color sensation were major abnormal findings. According to the neural damage, the patients were diagnosed as axial neuritis 7 cases, periaxial neuritis 2 cases, mixed type 3 cases and there were no significant changes on fundus, color sensation or visual field in 5 cases. In 17 cases, none of the patient showed the appearance of retinitis. The impairment of visual acuity and the duration of damage were related to the daily dosage significantly. After stop of ethambutol and vasodilators or neurotrophic drugs were given, the function of optic nerves were recovered. CONCLUSIONS: To prevent the damage of optic nerves by the toxicity of ethambutol, the appropriate small dosage of ethambutol is recommended, regular examination and monitoring of visual function is necessary. The physicians should be fully aware of the diagnosis and clinical manifestations of ocular toxicity of ethambutol, as soon as the diagnosis is made, ethambutol should be stopped immediately and appropriate therapy should be given.

Antitubercular Agents↗
PubMed1999

[Transferring of mdr1 gene into murine bone marrow cells and its protective effects on hematopoietic cells against toxicities of anticancer agent].

OBJECTIVE: To investigate the protective effects of mdr1 gene on hematopoietic cells against anticancer agents and to explore an effective approach to prevent myelosuppression due to chemotherapy. METHODS: mdr1 gene was transferred into murine bone marrow cells with plasmid pHaMDR1/A by the mediation of lipofection. Pgp, a product of mdr1 gene expression, and its function were detected by flow cytometry, immunohistochemistry, and rhodamine test respectively. Also, the resistance of transferred murine bone marrow cells to anticancer agents was tested by colony-forming unit test after exposure to anticancer agents and by bone marrow transplantation murine model. RESULTS: mdr1 gene was successfully transferred and expressed in bone marrow cells. Transferred murine bone marrow cells were resistant to anticancer agents both in vitro and in vivo. CONCLUSIONS: Transfection of mdr1 gene into hematopietic cells can protect bone marrow cells against the toxicities of anticancer agents.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1999

[Helicobacter pylori infection and expression of PCNA, p53, c-erbB-2 in carcinoma and precancerours lesions of the stomach].

OBJECTIVE: To study the role of Helicobacter pylori (Hp) in gastric carcinoma. METHODS: Hp was examined in 70 patients with gastric carcinoma, 62 patients with pre-malignant lesions and 16 controls by improved Warthin-Starry method and PCNA, p53, cerbB-2 protein examined immunohistochemically. RESULTS: The frequency of Hp infection in gastric carcinoma and its precusor lesions was significantly higher than that in the controls. There was no significant difference in Hp infection rate between gastric carcinoma and its precursor lesions, nor between the intestinal type and diffuse type of gastric carcinoma. Hp infection correlated well with expressions of PCNA, c-erbB-2 and with co-expression of PCNA, p53 and c-erbB-2 in gastric carcinoma and its precusors. p53 protein was expressed only in gastric carcinoma, and its expression level was higher in the presence than in the absence of Hp infection (P < 0.01). CONCLUSION: Hp might act as a tumor promoter in the genesis of gastric cancer.

Helicobacter Infections↗
PubMed1999

[Comparative study of three different chemotherapy protocols for advanced non-small-cell lung cancer].

OBJECTIVE: To compare the efficacy and toxicity of three different chemotherapy protocols for advanced non-small-cell lung cancer (NSCLC). METHODS: The clinical data of 93 cases with advanced NSCLC treated with (1) ifosfamide plus vindesine plus cisplatin (IVP, 31 cases), (2) mitomycin C plus vindesine plus cisplatin (MVP, 30 cases), and (3) cyclophosphamide plus adriamycin plus cisplatin (CAP, 32 cases) were analysed. RESULTS: The response rate was 48.4% in patients treated with IVP, 40.0% in those treated with MVP, and 28.1% in those with CAP, respectively. The major toxic reactions in the three groups were tolerable myelo-suppression and hair loss. CONCLUSION: IVP and MVP are effective and safe chemotherapeutic protocols for the treatment of advanced NSCLC patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

[The significance of detection of hepatitis C virus RNA in peripheral blood mononuclear cells of patients with chronic hepatitis C].

OBJECTIVE: To determine the role of peripheral blood mononuclear cells (PBMCs) in hepatitis C virus (HCV) infection. METHODS: HCV RNA, HCV antigen and Fas antigen were detected in PBMCs of 22 patients with chronic hepatitis C, 21 renal dialysis patients with anti-HCV positive and 12 health blood donors as normal controls. All specimens were studied by electronic microscope (EM). RESULTS: (1) The positive rate of HCV RNA in PBMCs of 22 patients with hepatitis C was 77.3% (17/22). (2) EM showed that HCV particles replicated in PBMCs of the patients with HCV infection, but not in the serum of patients with negative HCV RNA and healthy controls. (3) HCV RNA were positive both in the serum and PBMCs of 8 patients with HCV particles positive and had a close relationship with HCV antigen and Fas antigen. The expression of HCV and apoptosis were found in the cytoplasm of PBMCs in these 8 patients. CONCLUSION: (1) Hepatitis C virus could replicate in PBMCs and produce infectious HCV particles. (2) HCV in PBMCs may act as the source of reinfection for HCV and lead to persistent infection and recurrence.

Adult↗
PubMed1999

[A clinical analysis of Mooren's corneal ulcer].

OBJECTIVE: To investigate the clinical characteristics and to compare the effects of several therapies of Mooren's corneal ulcer. METHODS: 550 consecutive in-patients with Mooren's corneal ulcer were clinically analyzed, including the age, sex, laterality of the eye, ulcer location, rate of perforation, cure rate of surgeries, recurrent rate, and the effects of conjunctiva excision, lamellar keratoplasty (LKP), LKP plus cyclosporin A eye drops. RESULTS: The average age of onset of the ulcer was 48.4 years old, the ratio of male to female was 1:0.74, bilateral disease occurred in 165 cases (30.0%) of whom 52 cases (31.5%) were in the younger group and 113 (68.5%) in the older group. There were 501 eyes (70.1%) with the ulcer located at the limbus of palpebral fissure, and 95 out of 715 eyes with the disease had corneal perforation, the rate of perforation being 13.3%, 41 cases (43.2%) in the younger group and 54 cases (56.8%) in the older group. The postoperative recurrent rate was 25.6%. The cure rate of once LKP plus cyclosporin A eye drops was 73.7%, the final cure rate was 95.6%, and the preservative rate of the corneal anatomical structure of the surgeries was 99.7%. CONCLUSION: LKP plus cyclosporin A eye drops is an effective treatment of Mooren's corneal ulcer.

Adolescent↗
PubMed1999

[A study on immunogenicity and safety of bivalent inactivated vaccine against hemorrhagic fever with renal syndrome].

OBJECTIVE: To study side effects and effectiveness of bivalent inactivated vaccine against hemorrhagic fever with renal syndrome in population of a randomized controlled field trial. METHODS: Serum indirect immunofluorescent antibody in 167 persons and neutralization antibody (types I and II) in 69 persons, who received three-dose vaccine, were determined two weeks after immunization, and side effects in 657 vaccinees were observed within 72 houses after immunization. RESULTS: Serum positive conversion rate of indirect immunofluorescent antibody was 99.04% (166/167) with GMT of 24.51 +/- 2.06. Serum positive conversion rate of neutralization antibody was 100% (69/69), 91.30% (63/69) for types I and 88.41% (61/69) for type II, respectively. GMTs for type I and II neutralization antibody were 18.27 +/- 2.21 and 12.47 +/- 2.16, respectively. Side effects at local site vaccinated of the body and temperature rising could be seen in 1.48% and 0.36% of the vaccinees, respectively. No severe side effect and abnormal reaction was found in vaccinees on the field. CONCLUSION: Immune response to bivalent inactivated vaccine against hemorrhagic fever with renal syndrome was satisfactory with slight side effect.

Adolescent↗
PubMed1999

[Urotoxic effect to intestinal bacteria in patients with chronic renal failure].

UNLABELLED: To analyse the differences of intestinal bacterial quality and quantity, the feces taken from chronic renal failure(CRF) and healthy subject were cultured aerobicly. Then the isolated E. coli from CRF patients and healthy subjects was inoculated respectively into cultural medium with CRF serum and incubated whose concentration of UN, Cr and UA in medium before and after incubation was measured to observe the bacteria degrade of the above-mentioned urotoxin. RESULT: The intestinal E. coli can apparently degrade UN, Cr and UA in CRF patients which suggests that urotoxin may induce E. coli variation.

Adolescent↗