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Biomedical subjects

X Chen

Publications and source records attributed to X Chen.

At least 775 records · Page 43Linked to original sources
PubMed1999

[Study on the sensitization of acute myeloid leukemia cell to daunorubicin by recombinant human interleukin-3].

OBJECTIVE: To evaluate the effect of recombinant human interleukin-3(rhIL-3) on the sensitization of acute myeloid leukemia(AML) cells to daunorubicin(DNR). METHODS: AML cells were cultured in a DNR-containing medium supplemented or not with rhIL-3. CFU-AML was assayed by semi-solid culture, proliferation and differentiation of AML cells were assayed by flow cytometry, cytomorphology and benzidine staining. Intracellular DNR concentration was measured by spectrophotofluorometry. RESULTS: rhIL-3 could enhance the proliferation but not differentiation of AML cells in vitro, and had no effect on DNR intake and exclusion of AML cells while enhancing their sensitivity to DNR. CONCLUSION: rhIL-3 combined with DNR might improve the therapeutic effect of AML.

Adolescent↗
PubMed1999

[Urinary diversion in the one-stage hypospadias repair].

OBJECTIVE: To investigate whether the urinary diversion is helpful for healing of the neourethra. METHODS: Twenty-four cases that had received one-stage urethroplasty were divided into two groups and analyzed retrospectively. The urinary diversion was used in one group of 10 cases. In another group of 14 cases no urinary diversion was used. RESULTS: One case developed a fistula and wound infection in the urinary diversion group. In the no urinary diversion group, 2 out of 5 cases treated with the penile ventrolateral island skin flap urethroplasty developed wound infection and fistulas; excellent results were achieved in all 4 cases treated with the scrotal septal vascular pedicle skin flap urethroplasty; 2 cases developed fistulas and one case had wound infection in the 5 cases treated with the transverse preputial island flap urethroplasty. CONCLUSION: The urinary diversion was not to be used in one-stage urethroplasty using scrotal septal vascular pedicle skin flap. When the neourethra was reconstructed by the penile ventrolateral island skin flap or the transverse preputial island flap, urinary diversion is helpful for spontaneous healing of small fistulas and useful in reducing the incidence of fistulas.

Adolescent↗
PubMed1999

Normalization of auditory evoked potential and visual evoked potential in patients with idiot savant.

OBJECTIVE: To investigate the variations of auditory evoked potentials (AEP) and visual evoked potentials (VEP) of patients with idiot savant (IS) syndrome. METHODS: Both AEP and VEP were recorded from 7 patients with IS syndrome, 21 mentally retarded (MR) children without the syndrome and 21 normally age-matched controls, using a Dantec concerto SEEG-16 BEAM instrument. RESULTS: Both AEP and VEP of MR group showed significantly longer latencies (P1 and P2 latencies of AEP, P < 0.01; N1 and N2 latencies of VEP, P < 0.01/0.05), lower P2 amplitudes (P < 0.01) and higher P3 amplitudes (P < 0.01), as compared with normal controls. But none of above-mentioned changes was found with IS group. Almost all MR patients (90.1%) presented P4 component in both AEP and VEP, which was also in sharp contrast with its incidence in other 2 groups (IS: 14.3%; normal controls: 9.5%). CONCLUSION: Patients with idiot savant syndrome presented normalized AEP and VEP.

Adolescent↗
PubMed1999

[Effects of NGF and CNTF on NO level in brain of burn rats].

OBJECTIVE: To investigate the injurious effects of NO to the brain and protective effect of NGF and CNTF following burn injury in rats. METHODS: Following intubation of the lateral cerebroventricle, the rats were divided into four groups:sham burn, burn, burn + NGF, burn + CNTF. The contents of NO in various parts of brain in rats with 30% TBSA third degree scald were measured. RESULTS: The contents of NO were increased in burned rats. NGF and CNTF could lower the contents of NO. CONCLUSION: The brain injury caused by burns may be associated with increase of NO. The protective effect of NGF and CNTF on the brain of burn rats may be related to lowering of NO.

Animals↗
PubMed1999

Changing pattern of heart diseases in Shanghai from the 1950s to 1980s.

OBJECTIVE: To determine the pattern of dynamic change in types of heart diseases in the past 4 decades for providing a reference to treatment and prevention of heart diseases in China. METHODS: All adult cardiac patients admitted to the Zhong Shan Hospital and Hua Shan Hospital from 1948 to 1989 were analyzed. The constituent ratio of different heart diseases in the 1950s, 1960s, 1970s and 1980s was compared. RESULTS: The percentage of heart diseases among medical inpatients increased in each of the recent 4 decades, from 9.89%, 15.69%, 20.90% to 23.54% respectively. The constituent ratio of different heart diseases changed, coronary heart disease constituted the highest proportion, next came rheumatic heart disease, and congenital heart disease was in third place. Congenital heart disease, myocarditis, cardiac dysrhythmia without organic heart disease, cardiomyopathy and endocarditis increased, rheumatic heart disease, pulmonary heart disease and hypertensive heart disease apparently decreased; syphilitic heart disease could rarely be encountered. CONCLUSION: China is now facing a low overall death rate, a long life expectancy and an aging population. The incidence of heart diseases increased gradually and patterns of heart diseases kept changing. The overall trend is that heart diseases which were not related to infection are increasing while heart diseases related to bacterial infection are decreasing.

Arrhythmias, Cardiac↗
PubMed1999

Transvenous pectoral implantation of single lead implantable cardioverter defibrillator.

OBJECTIVE: To report our initial experience of transvenous pectoral implantation of single lead implantable cardioverter defibrillator (ICD) in fifteen patients. METHODS: Fifteen patients (male 13, female 2, mean age of 51.7 years), including dilated cardiomyopathy in 4, hypertrophic cardiomyopathy in 2, coronary artery disease in 5 and syncope of unknown etiology in 2, underwent ICD implantation. Indications for ICD implantation were ventricular fibrillation (8 patients) and refractory ventricular tachycardia (7 patients). All patients had syncope out of hospital. The ICD system were Medtronic Jewel active can in 5 patients (Model 7219C in 2, 7220C in 3) and CPI Ventak PRxIII in 9 patients. For active can, shocks were delivered through distal coil to ICD shell and for PRxIII through the endotak lead of proximal to distal coil. Successful implantation criteria was 2 consecutive defibrillation at less than 24 J. RESULTS: All 15 patients had successful implantation using single lead ICD system in catheter laboratory. The mean defibrillation threshold was 12.8 J (5-15 J) and R wave was 9.9 mV (3.7-14.6 mV). All devices were of pectoral implantation. No operative and perioperative complications occurred. In 7.6 months (1-18 months) of follow-up, 3 patients had VT terminated by antitachycardia pacing (ATP) and 1 patient VF terminated by shock. CONCLUSION: Transvenous pectoral implantation of single lead ICD is easy to perform and has high defibrillation efficacy and should be a preferred approach.

Defibrillators, Implantable↗
PubMed1999

Cross-sectional survey of intralymphocytic and serum elements in hypertensive patients.

OBJECTIVE: To investigate the distribution characteristics of some common and trace elements in both serum and lymphocyte in patients with essential hypertension and to analyse their possible role in the pathogenesis of hypertension. METHODS: A cross-sectional study was carried out in 102 hypertensive patients matched with equal number of normotensive subjects by sex, age, and hypertensive family history; all of them were randomly selected from the same community. Both intralymphocytic and serum concentrations of some relevant elements including Na+, K+, Ca2+, Mg2+, Zn2+, Cu2+ and P were measured for all studied subjects, using the inductively coupled plasma spectrometry (ICPS). RESULTS: 1. Both intralymphocytic and serum concentrations of Na+ (P = 0.009, 0.004 respectively), and Ca2+ (P = 0.001, 0.049 respectively) in hypertensive group were significantly higher than those in the normotensives. 2. Stepwise regression analysis disclosed that systolic and diastolic blood pressure had significant correlation with age, serum Na+/K+ ratio and intralymphocytic Ca2+, Mg2+ concentrations (P < 0.001 for both). 3. According to hypertensive family history, the method of multiple variance analysis had been employed for 4 subgroups and the results revealed that the concentrations of serum Ca2+ and lymphocytic Na+ were significantly higher in hypertensives with or without family history than in normotensives without family history. Furthermore, intralymphocytic Na+ concentration was significantly higher in normotensives with positive family history than that in normotensives without family history. CONCLUSION: The serum and intralymphocytic distribution characteristics of elements in hypertensive patients compared with normotensive controls suggested that there might exist certain defects of the ion-transporting system on cell membrane which might be genetically linked.

Adult↗
PubMed1999

Classification and digital subtraction angiography evaluation of carotid cavernous fistulas.

OBJECTIVE: To investigate the role of digital subtraction angiography (DSA) in evaluation of carotid cavernous fistulas, and to initiate a new classification for carotid cavernous fistula. METHODS: Cerebral angiography and selective external and internal carotid angiography were carried out in 56 patients who were classified into 5 types according to their hemodynamic features. RESULTS: The types were A (38 patients), B (4), C (10), D (2), and E (2). One of the 38 direct fistulas was located at C1 of the cavernous segment. Fistulas at C2 were observed in 10 patients, at C3 in 4, at C4 in 10 and at C5 in 5. The anterior communicating arteries were patent and well compensated in 33 of the 56 patients. The posterior communicating arteries were patent and well compensated in 39 patients. Both communicating arteries were well compensated in 31 patients. Fifty of the 56 patients were drained by ophthalmic veins, 47 by inferior petrous sinuses, 18 by cortical veins, and 8 to the posterior fossa region. CONCLUSIONS: Digital subtraction angiography was helpful in localization of the rents in carotid cavernous fistulas, in evaluation of function of Willis circles and provided valuable information for treatment of carotid cavernous fistulas. Carotid cavernous fistulas were divided into 5 categories: type A, B, C, D and E, among which type E was not previously described elsewhere.

Adolescent↗
PubMed1999

Three-dimensional electron beam CT angiography in the diagnosis of intracranial aneurysms.

OBJECTIVE: To assess the accuracy of three-dimensional electron beam CT angiography (3D-EBCTA) in the detection of intracranial aneurysms. METHODS: 31 patients with suspected cerebral aneurysms (including 3 post-operative patients) were examined by 3D-EBCTA. Those receiving angiography or surgery acted as controls. Maximum intensity projection (MIP) and shaded surface display (SSD) reconstruction ways were selected. RESULTS: 24 aneurysms were found in 23 patients. Of the 31 patients, false positive was noted in 1 patient, and false negative in 2 on 3D-EBCTA. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 92.0%, 88.9%, 91.2%, 95.8% and 80.0% respectively. CONCLUSION: 3D-EBCTA is an noninvasive, rapid, valuable method in diagnosis and screening of patients with suspected aneurysms. The reconstruction modes such as MIP and SSD should be used together to optimise the visualization.

Adult↗
PubMed1999

[Antisense oligonucleotide attenuates renal tubulointerstitial injury in mice with unilateral ureteral obstruction].

OBJECTIVE: To inhibit the expression of ICAM-1 mRNA with the mouse ICAM-1 phosphorothioate antisense oligodeoxynucleotide (ASON) and to investigate the role of ICAM-1 in the pathophysialogical process of renal injury in unilateral ureteral obstruction (UUO) animal model. METHODS: After unilateral ureteral ligation, the mice were treated with ICAM-1 ASON, which was injected intravenously at the dosage of 1 mg/kg/day every other day for one week. Other mice treated with control oligonucleotide or normal saline solution only were taken as controls. The expression of ICAM-1 protein and the number of Mac-1 positive cells were measured by immunohistochemical staining. The pathological changes of the obstructed kidney in the mice were analyzed by PAS-staining. Total RNA renal tissue was extracted for the analysis of the ICAM-1 mRNA by methods of Northern blotting. RESULTS: The expression of ICAM-1 protein and the number of Mac-1 positive cells were reduced markedly in the obstructed kidneys of the mice treated with the ICAM-1 ASON(110 +/- 14 [symbol: see text]/mm2 vs 270 +/- 13 [symbol: see text]/mm2). The results of Northern blotting also showed marked decrease of the expression of ICAM-1 mRNA in the kidney of the mice after treatment with ICAM-1 ASON. There were marked inflammatory cells infiltration in the tubulointerstitium, markedly dilated tubules, and extraceliular matrix accumulation in the obstructed kidneys on the 7th day after UUO operation. The treatment of ICAM-1 ASON can alleviate the lesions of the obstructed kidney except for the dilation of the tubules. There was no difference in the body weight, liver weight, spleen weight, the level of BUN and SCr, the level of GPT as well as the urine protein of the mice treated with ICAM-1 ASON, compared with those in control Oligodeoxynucleotide-treated and saline-treated mice. CONCLUSIONS: ICAM-1 is a very important factor in the pathogenesis of the UUO animal model. The mouse ICAM-1 ASON has therapeutic effects on the injury of the obstructed kidney without apparent side effects.

Animals↗
PubMed1999

[Cognitive evoked potentials in patients with schizophrenia].

OBJECTIVE: To investigate the features of cognitive evoked potentials (CEPs) in schizophrenics and the changes of CEPs between the duration of episode and remission. METHODS: The present study was made with stimuli of auditory, visual, and somatosensory modalities. CEPs were recorded from 31 episodical schizophrenics and 25 of them were retested when their clinical symtoms rempitted. RESULTS: The episodical patients showed significantly longer A latency (P < 0.05) and PINV latency (P < 0.01), and smaller A-S2' area (P < 0.01). Shorter latency was associated with P2 of auditory evoked potential, visual evoked potential and somatosensory evoked potential (P < 0.05), P1 of AEP, N2 of VEP, and N1 of SEP (P < 0.05). Longer latency was associated with P3 of AEP (P < 0.05). Diminished amplitude was associated with N1-P2 of AEP and N1-P2 of VEP, P2 of VEP, and P2-N2 of SEP (P < 0.05). The follow-up study revealed that when the psychiatric symptoms remitted, the waveform of CEPs became more steady; amplitude B of CNV, N1-P2 of VEP and P2-N2 of SEP were increased (P < 0.05); the amplitude P2 of AEP and VEP, and P1 of AEP were increased into the normal range. CONCLUSION: The variations of CEPs are the state marker of schizophrenia.

Adolescent↗
PubMed1999

Dose-effect of dietary L-arginine supplementation on burn wound healing in rats.

OBJECTIVE: To investigate the dose-effect of dietary L-arginine supplementation on burn wound healing in rats. METHODS: 218 Sprague-Dawley rats (weighing 200-250 g) were subjected to 10% deep partial thickness scald burns and were randomized into six groups. Groups A, B, C, D, E and F received 800, 400, 200, 100, 50 and 0 mg.kg-1.d-1 L-arginine in the form of L-arginine solution, and 0, 727, 1090, 1272, 1364, and 1454 mg.kg-1.d-1 glycine, respectively. Each solution was isonitrogenous. The times of completing re-epithelization were recorded. The contents of hydroxyproline (OHP) in burn wound area (index of reparative collagen synthesis) and the ratios of type I and type III collagen were examined in all groups. RESULTS: The times of completing re-epithelization (day) in groups A, B, C, D, E, and F were 24.9 +/- 1.95, 22.5 +/- 2.0, 20.2 +/- 2.4, 23.5 +/- 2.6, 23.8 +/- 3.5, and 24.7 +/- 2.3, respectively. The contents of hydroxyproline in groups B, C and D were higher than in groups A, E and F on PBD 7, 10 and 14. The ratios of type I and type III collagen in groups B, C and D were lower than in groups A, E and F. CONCLUSION: Oral dietary L-arginine supplementation from 100 mg.kg-1.d-1 to 400 mg.kg-1.d-1 shortened the times of re-epithelization, increased amounts of hydroxyproline, and accelerated the synthesis of reparative collagen in burn rats.

Animals↗
PubMed1999

A feasible and effective technique for the detection of Schistosoma japonicum cercaria-infested water.

OBJECTIVE: To develop a new technique for detecting Schistosoma japonicum (S. japonicum) cercariae so as to predict the distribution of area with high transmission potential and to control acute infection of schistosoma. METHODS: A C-6 film was established and used to adhere the cercariae on water surface and compared with a few other conventional detecting techniques. RESULTS: The average rate of the cercaria-recovery was 40% in laboratory and field using C-6 film, which was 20 times higher than that of traditional nylon-tissue adsorbing and precipitating method. Either in some areas where oncomelania were present or in some places where the snail had been under control, the technique could detect the cercariae. CONCLUSION: The technique can be characterized by a feasible, economical, promptly accessible method, especially for field application.

Animals↗
PubMed1999

[Dynamic changes and localization of plasma heparin cofactor II before and after delivery in hypertensive pregnancy].

OBJECTIVE: To explore the physiological significance of the anticoagulation effect of heparin cofactor II (HCII) in vivo and investigate the pathogenesis of the development of thrombosis in hypertensive pregnancy. METHODS: 1. Plasma level of HCII activity was measured by chromogenic assay in 18 healthy adults, 18 normal pregnant women and 29 hypertensive pregnant women before and after delivery. 2. Plasma level of HCII antigen was measured by Western blot in 29 hypertensive pregnant women before and after delivery. 3. The distribution of HCII in the placenta was determined by immunofluorescent method. RESULTS: The plasma HCII activity and antigen content in hypertensive pregnancy decreased significantly before delivery. They correlated with the severity of hypertensive pregnancy, and restored to normal after delivery. No HCII was found in normal and pathological placenta. CONCLUSION: 1. Plasma HCII activity decreased during pregnancy in hypertensive pregnancy. 2. The placenta is not the target of HCII. 3. Dynamic determination of plasma HCII level can reflect the severity of hypertensive pregnancy and be used as one of prognostic indices.

Adult↗
PubMed1999

Comparison of some antineoplastic drugs on inhibiting thrombin catalizing fibrinogen clotting in vitro.

OBJECTIVE: To classify the effect of thrombin, the key enzyme which enables fibrinogen to form fibrin (fibrinogen clotting) on the formation of metastasis by comparing the inhibition of some antineoplastic drugs on fibrinogen clotting in vitro. METHODS: Time intervals of different drugs to reach a maximum OD (340 nm) data in fibrinogen solution added with thrombin were used in this work. RESULTS: It was found that L-4-oxalysine (8-40 micrograms/ml) and arabinosyl cytosine (10-50 micrograms/ml) could inhibit the effect of thrombin by extending the fibrinogen clotting time to 100%-150% (P < 0.001) and 61%-100% (P < 0.001) while the other antimetastatic drugs razoxane, probimane, adriamycin, harringtonine homoharringtonine and alpha-anordrin at the treatment concentrations showed no such activity. The positive rate of drugs to thrombin activity was approximately 25%. CONCLUSION: It suggests that L-4-oxalysine and arabinosyl cytosine may even exhibit antimetastatic effect through thrombin-fibrinogen pathway, and thrombin might operate in tumor metastasis for only limited step but crucial to fibrin formation in tumor nodules.

Amino Acids, Dicarboxylic↗
PubMed1999

[Multiple tumor suppressor 1/p16 gene alterations in human esophageal squamous-cell carcinoma: clinical significance and regional difference].

OBJECTIVE: To further understand multiple tumor suppressor 1/p16 (mts1/p16) gene alterations in squamous-cell esophageal carcinoma (EC) in relation to its biologic behavior and regional difference. METHODS: Samples of human EC from 92 patients residing in Zhejiang province and in Linxian, Henan province were analyzed for the expression, mutation and deletion of the multiple tumor suppressor gene (mts1/p16) by immunohistochemical staining, polymerase chain reaction and single strand conformation polymorphism. RESULTS: mts1/p16 expression at protein level was demonstrated in 44 cases (47.8%). Gene deletion was detected in 22 cases (23.9%) and point mutation in 5 cases (5.4%). Expression of mst1/p16 showed significant correlation with pathologic staging, lymph node status and survival. However, deletion of mst1/p16 did not show correlation with the clinico-pathologic parameters. EC patients in stage T2 from Linxian had significantly lower rate of mst1/p16 protein expression compared to those from Zhejiang province at the same time period. Moreover, there was close association between gene alterations (mutation + deletion) and frequency of lymph node metastasis in Zhejiang EC patients. No such association was observed in EC patients from Linxian. CONCLUSION: msts1/p16 gene alteration is a common genetic event in the carcinogenesis and progression of human esophageal cancer. EC patients from two different regions present differential alterations in mst1/p16 gene.

Carcinoma, Squamous Cell↗