Biomedical subjects

X Wu

Publications and source records attributed to X Wu.

At least 613 records · Page 34Linked to original sources

PubMed1998

A pathological study of in situ thrombosis of small pulmonary arteries and arterioles in autopsy cases of chronic cor pulmonale.

OBJECTIVE: To investigate the incidence of in situ thrombosis of small pulmonary arteries and arterioles during the exacerbation stage of chronic cor pulmonale. METHODS: 49 autopsy cases died from the exacerbation of chronic cor pulmonale were chosen as the study group, while 103 other autopsy cases without chronic cor pulmonale and disseminated intravascular coagulation (DIC) as control group. Morphologic and morphometric studies were taken on lung tissues and other organs with focus on the thrombi in small pulmonary arteries and arterioles. RESULTS: 44 cases of the study group had multiple thrombi in small pulmonary arteries and arterioles, the incidence is 89.8%, and in 9 of them, thrombi in proximal pulmonary arteries co-existed, the incidence is 18.4%. 80% of the thrombi existed in pulmonary arterioles. In the control group, only 3 cases had thrombi in small pulmonary arteries and arterioles, the incidence is 2.9%. All thrombi adhered to endangium, implying that they were in situ thrombi. No intravascular thrombosis was found in other organs. chi 2 test showed that the incidence of thrombosis and the number of thrombi in small pulmonary arteries and arterioles in cases with chronic cor pulmonale were significantly higher than those of the control group (P < 0.01). CONCLUSIONS: Multiple in situ thrombosis in small pulmonary arteries and arterioles is a prominent and common pathological change during the exacerbation stage of chronic cor pulmonale. The study suggests a new diagnostic and therapeutic concept and gives a morphological and theoretical basis for the clinical application of anticoagulants or even the thrombolytic agents for the cases of chronic cor pulmonale in the exacerbation stage.

Aged↗

PubMed1998

[Clinical observation of seventeen cases of carcinoma of the external auditory canal and middle ear].

The clinical observation of 17 cases with carcinoma of the external auditory canal and middle ear revealed that no other factors can affect the prognosis greatly except the death caused by recurrence of primary focus. Because operations would destroy the local anatomic structure and in most cases it is difficult to excise widely aggressive tumors perfectly, the author suggests that the auditory canals should be excised or extended mastoidotympanectomy with radiotherapy after operation be performed for the tumors limited to external canal or middle ear. Radiotherapy before operation can be conducted before extended mastoidotympanectomy or subtotal temporal bone resection for the cases with tumors beyond the middle ear. For the cases with tumors largely beyond the middle ear mastoidotomy can be performed before thorough radiotherapy.

Adenocarcinoma↗

PubMed1998

The evaluation of MR localization for intracranial arteriovenous malformation treated with gamma knife.

OBJECTIVE: To evaluate the image quality, treatment effectiveness and complications of intracranial arteriovenous malformation (AVM) treated with gamma knife by MR localization. METHODS: According to Spetzler-Martin grading system, 73 intracranial AVMs were classified and treated with gamma knife by MR localization. The follow-up period was 6 to 34 months. The quality of MR localization image, the changes of AVM nidi after treatment were analyzed. Using ANOV (analysis of variance) statistic methods, we explored the relationship among the edema surrounding the AVM nidus, the radiation dosage and the AVM volume after treatment. RESULTS: The margin of AVM nidus was clear in all images. In the 73 images, MR signal of the local cranial skin and bone on the fixed points of head frame disappeared in 11 (15%), high or low shallow curve signals in the cerebral border occurred in 5 (7%), the remaining 57 (78%) images had no artifacts. Based on the Spetzler-Martin grading score of AVM, the obliteration rates of AVM nidus were 100% in II, 88% in III, 57% in IV, 75% in V, 60% in VI during the 6-34 months follow-up after treatment. Edema around the AVM nidi occurred in 42 (57.5%) cases; among them, 27 were in slight degree, 10 in medium degree, and 5 in severe degree. Through ANOV statistic methods, we suggested that the degree of edema had no relation with the radiation dosage and AVM volume. Only one case had rebleeding 13 months after radiosurgery. CONCLUSION: MR localization for AVM treated with gamma knife is reliable and effective.

Adolescent↗

PubMed1998

Lidocaine improving the cerebral protection by retrograde cerebral perfusion.

OBJECTIVE: To determine whether lidocaine can improve the cerebral protection provided by retrograde cerebral perfusion. METHODS: Sixteen mongrel dogs were placed on cardiopulmonary bypass and cooled to 20 degrees C. Retrograde cerebral perfusion was then carried out for 120 minutes, with the external jugular venous pressure kept at 3.33 kPa. Cardiopulmonary bypass was resumed, and the animals were rewarmed to 36 degrees C. The animals were divided into two groups. In the lidocaine group (n = 8), lidocaine was administrated continuously throughout the experiment. In the control group (n = 8), normal saline was given at the same rate. RESULTS: In both groups, cerebral tissue creatine phosphate and adenosine triphosphate concentrations and energy charge increased by the end of hypothermic cardiopulmonary bypass, decreased continuously during retrograde cerebral perfusion, and recovered gradually after resuming cardiopulmonary bypass. Nevertheless, they recovered to significantly higher levels in the lidocaine group than in the control group (creatine phosphate: 2.44 +/- 0.53 versus 1.61 +/- 0.49 mumol/g wet weight, P = 0.006; adenosine triphosphate: 0.71 +/- 0.18 versus 0.50 +/- 0.17 mumol/g wet weight, P = 0.029; energy charge: 0.59 +/- 0.10 versus 0.48 +/- 0.09, P = 0.044) by the end of the experiment. There was no significant difference between the two groups in the cerebral tissue water content (control group: 77.6% +/- 1.9%; lidocaine group: 77.6% +/- 1.3%). CONCLUSION: Continuous lidocaine infusion accelerates the recovery of cerebral tissue high energy phosphate contents after resuming cardiopulmonary bypass, but it has no effect on the formation of cerebral edema after retrograde cerebral perfusion.

Adenosine Diphosphate↗

PubMed1998

Linkage analysis of the genetic markers of the candidate genes with non-insulin dependent diabetes mellitus in Chinese families.

OBJECTIVE: To explore the relationship between the genetic markers of the candidate genes (insulin receptor, glucose transporter 2 and glucokinase) and non-insulin dependent diabetes mellitus (NIDDM) in Chinese pedigrees. METHODS: Genomic DNA of 87 members in 12 Chinese NIDDM pedigrees was amplified using PCR technique. Denaturing polyacrylamide gel electrophoresis was applied to detect short tandem repeat polymorphisms. The linkage program was used under the models of autosomal dominant and recessive. The individuals with impaired glucose tolerance (IGT) of age < or = 45 and age > 45 were counted as affected and unknown status respectively. RESULTS: Linkage of insulin receptor gene and NIDDM was strongly and significantly rejected with total LOD score of-infinity (theta = 0.000). Linkage analysis of glucose transporter 2 gave the result with total LOD score of 2.646 (theta = 0.000) in 4 pedigrees. Linkage of glucokinase and NIDDM was of significance with total LOD score reaching 3.150 in the integration of 6 pedigrees. CONCLUSIONS: Mutations in or near the insulin receptor gene are unlikely to be the major cause of inherited predisposition to NIDDM in Chinese pedigrees that are related in this study, not excluding the principal role in the other Chinese or populations, while the mutations/variations near or at the glucose transporter 2 gene locus might be something of the cause, which needs more data to be ascertained, of familial NIDDM in Chinese pedigrees. However, the variations in or near the glucokinase gene might play a dominant role in the development of NIDDM in some Chinese and represent a subgroup of common NIDDM.

Adult↗

PubMed1998

Long-term efficacy of recombinant interferon alpha 2a in the treatment of chronic hepatitis C: a randomized prospective study comparing two dose schedules in Chinese patients.

OBJECTIVE: To compare the long-term efficacy of a dose of 3 million units (MU) of r-IFN alpha 2a (IFN-alpha 2a) three times a week (t.i.w.) for 6 months with a starting dose 6 MU for 3 months and subsequent reduction to 3 MU t.i.w for further 3 months. METHODS: Sixty-eight serological and histological chronic hepatitis C patients with elevated serum alanine aminotransferase (ALT) were enrolled and randomized into two groups. Sixty-three patients were completed with full course of treatment. Five patients were withdrawn from trial (2 due to personal reasons and 3 due to adverse drug reactions during treatment). Thirty patients received 6 MU IFN-alpha 2a t.i.w., 3 months followed by 3 MU t.i.w. for another 3 months (Group A). Thirty-three patients received 3 MU IFN-alpha 2a t.i.w. for 6 months (Group B). RESULTS: The sex, age, baseline serum bilirubin, ALT and aspartate aminotransferase (AST) levels were matched in both groups. At the end of the 6th month, the complete and partial response rates in Group A were 60.0% and 16.7% respectively, and the clearance of serum HCV-RNA was 53.3%. In Group B, the complete and partial response rates were 72.7% and 6.1% respectively, and the clearance of HCV-RNA was 61.3%. The patients were followed up for 6, 12, and 18 months after stopping treatment. In Group A, the rates of complete normalization of ALT and clearance of serum HCV-RNA at 24 months were 50.0% and 60.0% respectively. In Group B, the rates of normalization of ALT and clearance of HCV-RNA at 24 months were 54.4% and 41.9% respectively. The efficacy between the two groups showed no statistically significant difference. The response rates of treatment were similar to those in the patients with HCV genotype 1b and 2a. Six patients (10.8% of the study population) developed neutralization antibodies to IFN-alpha 2a during treatment, and four of them were responded to the treatment. Adverse drug reactions (ADR), were common, but most of them were tolerable, and the incidence of ADR was in both groups, but the severity was higher in Group A. CONCLUSIONS: IFN-alpha 2a is effective in the treatment of Chinese patients with chronic hepatitis C. The sustained response rates and adverse drug reactions among two dose schedule groups are similar.

Adolescent↗

PubMed1998

[Experimental colitis induced by dextran sulfate sodium].

In this study, experimental colitis in rats induced by dextran sulfate sodium (DSS) was performed. Twenty rats freely drank 3% DSS solution for 10 days. During the 10 days, symptoms (diarrhea, hemafecia) were observed daily, and at the same time the rats were colon-endoscopied. After that these rats were killed and their cola taken out to be examined grossly and histologically. It was found that colitis induced by DSS was similar to human ulcerative colitis in symptoms and in pathological changes.

Animals↗

PubMed1998

[Observation on inhibitory effect of tetrandrine on the growth of human skin fibroblast in vitro].

The effect of tetrandrine on the growth of human skin fibroblasts was observed in vitro culture. The result revealed that tetrandrine significantly inhibited the growth of fibroblast. The higher the concentration of tetrandrine, the higher the inhibition rate, forming a time-dependent relationship. The possible value of tetrandrine in the treatment of hypertrophic scar is discussed.

Alkaloids↗

PubMed1998

Glycophorin variants and contents of sialic acid and total sulfhydryl groups on erythrocyte membranes of residents in a malaria hyperendemic area.

OBJECTIVE: To conduct a screening survey of glycophorin (GP) variants and observe the content changes of sialic acid (SA) and total sulfhydryl (SH) groups on the erythrocyte membranes among residents in a tertian malaria hyperendemic area of Guizhou Province. METHODS: GP variants were detected in the erythrocyte hemolysates of 173 local residents at two villages of Libo County by SDS-PAGE on 10% to 15% gradients gel and Western immunoblotting. Their SA and total SH group contents were estimated in erythrocyte membranes by spectrophotometric methods. 114 healthy subjects in Changsha and 49 individuals at a neighbouring village of the above area showing low morbidity of malaria served as normal and endemic controls respectively. RESULTS: Three distinct types of GP variants were found among 19 propositi in this hyperendemic area. The incidence of GP variants was 7.9% (8/101) at Yaolu Village whose population was mainly composed of Yao ethnic group; while that of Buyi ethnic group at Maolan Village was higher (15.3%; 11/72). The erythrocyte membrane contents of SA in residents at both villages exhibited a very significant tendency of decline (P < 0.01), whereas those of total SH groups increased prominently in residents of Yaolu Village only (P < 0.05). CONCLUSIONS: The frequency of GP variants in this hyperendemic area does not depend upon the severity of malarial prevalence. The evident reduction of SA contents in the residents may be related to the breaking down of the SA residues on membrane GPs by the invasion of Plasmodium vivax.

Adolescent↗

PubMed1998

Mitochondrial gene defect in patients with chronic progressive external ophthalmoplegia.

OBJECTIVE: To detect the gene defect of mitochondrial DNA (mtDNA) from skeletal muscles in 2 patients with chronic progressive external ophthalmoplegia (CPEO). METHODS: After extraction of mtDNA, Southern hybridization was performed after restrictive digestion by Pvu II, EcoRI, Hind III, and Sacl. Then, we carried out polymerase chain reaction (PCR) and the enzyme digestion of the PCR products. Finally, mtDNA sequencing was done by automatic DNA sequence analyzer. RESULTS: In case 1, a 5 kb deletion was found by Southern blot analysis and PCR. And dosage analysis showed a heteroplasmic change with 44% mtDNAs deleted. In case 2, PCR plus restriction endonuclease Pvu II digestion demonstrated a mutation which was confirmed by DNA sequencing to be a single base substitution (T-->C) inducing a novel Pvu II site around 10,909 on mtDNA sequence. The laser image analyzer measurement revealed the mutation was almost homologous (99.4% mutant). CONCLUSIONS: In case 1, a 5 kb deletion found in mtDNA is called "common deletion" according to the literature. In case 2, a novel Pvu II site was found. It seems to be a de novo point mutation affecting ND4 in published CPEO research and is first reported in Chinese population. This point mutation does not induce an amino acid(Phe) change according to the published human mitochondrial genetic code as well as the mtDNA sequence. Whether it affects the translation efficiency or transportation of signals between mitochondrial and nuclear genome needs further studies.

Adult↗

PubMed1998

[Studies on mutation of rifampicin-resistant genes in M. tuberculosis].

OBJECTIVE: To understand mutation of rifampicin-resistant genes in M. tuberculosis clinical isolates, and to develop a new method for detecting drug resistance. METHOD: Analyzing the rpoB genes in 50 M. tuberculosis clinical isolates with polymerase chain reaction-single-stranded conformation polymorphism (PCR-SS-CP) and PCR-direct sequencing(PCR-DS) techniques. M. tuberculosis strain H37Rv was used as control. RESULT: Of 3 drug-sensitive isolates and 2 non-rifampicin-resistant isolates selected, only 1 drug-sensitive isolate with abnormal rpoB SSCP profile had TCG-->TTG mutation at codon 531. Of 45 rifampicin-resistant isolates, 35 isolates with abnormal SSCP profiles had mutations in rpoB sequences, in which 14 isolates displayed TCG-->TTG or TGG or TAC mutations at codon 531, 14 had CAC-->TAC or GAC or CCC or CTC or GTC mutations at codon 526, 2 had GAC-->GTC or TAC mutations at codon 516, 2 had two point mutations, and 3 had different rpoB sequences from that of M. tuberculosis. CONCLUSION: Resistance to rifampicin in most M. tuberculosis isolates is due to the mutations on the genes encoding the RNA polymerase subunit (rpoB). PCR-SSCP and PCR-DS techniques might become simple, rapid and reliable diagnostic tests for rifampicin resistance in clinical isolates.

Antitubercular Agents↗

PubMed1998

[E2-induced prolactin-secreting tumor of heteroplasty pituitary in renal capsule of the rats].

OBJECTIVE: A prolactin-producing tumor induced by 17-beta-estradiol (E2) in isotransplanted pituitaries under renal capsules of SD rats were studied. METHODS: Male SD rats (30 days old) were transplanted with an isologaus pituitary under renal capsule and treated with subcutaneous implantation of an empty or E2-laden silastic capsule. RESULTS: After treated with E2 for 60 days and 120 days, both the eutopic and ectopic pituitaries were more than three times heavier than those from control rats, accompanied by hyperprolactinemia, and the body weight of rats decreased significantly. The effects of E2 on the weight of eutopic pituitary and the concentration of plasma PRL were time-dependent. In situ hybridization was employed to measure the levels of PRL mRNA expression in cells from the eutopic and ectopic pituitaries 120 days after treatment of E2. The PRL mRNA contents in both the eutopic and ectopic pituitary cells were much greater than those in untreated pituitary cells. But PRL mRNA levels showed no significant difference between the eutopic and ectopic pituitary cells. CONCLUSIONS: Our previous data has shown that prolactinomas can be induced by chronic treatment of E2 in eutopic pituitaries of SD rats. In present study it appeared that E2 exerted similar effect on the ectopic pituitaries which were distant from the hypothalamus. Our results also demonstrated that E2 could promote the PRL gene expression in both the eutopic and ectopic pituitary cells, and there was no significant difference between them. Our data suggested the possibility of PRL-producing pituitary tumors could originate from anterior pituitary.

Animals↗

PubMed1998

[Effects of morphine on the formalin induced IL-2R beta mRNA expression of rat hippocampus].

Using method of in situ hybridization, the effects of subcutaneous injection (s.c.) of formalin (For) into one hindpaw (hyperalgesia) on IL-2R beta mRNA expression in hippocampus (Hip) were studied. In addition, the effects of coadministration of morphine (i.p.) or ACTH (i.p.) with For (s.c.) were studied also. It was found that IL-2R beta mRNA was present in normal rat's Hip, intensely in granular cells of dentate gyrus and CA1-CA4 neurons. Subcutaneous injection of For increased IL-2R beta mRNA from 6 h to at least 24 h, reaching a peak at 12 h. Coadministration with morphine enhanced the effects of For on IL-2R beta mRNA expression, but no significant change was found with coadministration of ACTH. The above results suggest that IL-2R might be involved in pain modulation.

Adrenocorticotropic Hormone↗

PubMed1998

[Study on the mutations of ahpC genes in M. tuberculosis isoniazid-resistant isolates].

OBJECTIVE: To investigate the mutations of ahpC genes in M. tuberculosis isoniazid-resistant isolates, and to study the correlation between ahpC alterations and isoniazid resistance. METHOD: Analyzing the ahpC coding sequences and ahpC promoters in 62 M. tuberculosis clinical isolates with PCR-SSCP method. M. tuberculosis strain H37RV was used as control. RESULT: The ahpC coding sequences showed normal SSCP profiles in 62 clinical isolates. AhpC promoter mutations were identified in 5 of 12 high isoniazid-resistant strains, and were not altered in 18 low isoniazid-resistant and 32 drug-sensitive isolates. CONCLUSION: The mutation of ahpC coding gene was not correlated with isoniazid-resistant M. tuberculosis isolates. AhpC promoter mutation was a compensatory change in katG-defective and catalase-negative isolates, may be used as a indirect marker for high resistance to isoniazid.

Antitubercular Agents↗

PubMed1998

[Effects of whole-body vibration on human tracking performance and visual-motor reaction].

Dual task test (light target tracking and visual-motor reaction of visual oddball mode) and pursuit aiming test were done in 17 male healthy subjects after 30min exposure to whole-body vibrations of 20 Hz 0.15 gz or 20 Hz 0.3 gz. Mean accuracy rate of visual-motor reaction and target stimulus reaction accuracy rate after 0.3 gz vibration were significantly lower than those of control group (P < 0.05), while after 0.15 gz vibration, the changes were not significant. Comparing with control group, the total number of right and wrong pointing, pointing speed in pursuit aiming test were significantly lower (P < 0.05) after vibration. However, light target tracking error, mean reaction time of visual-motor reaction and pointing accuracy rate of pursuit aiming test had no significant change after exposure to any kind of the vibrations. It may be concluded that some kinds of effect on human tracking performance and visual-motor reaction were observed after exposure to whole-body vibration.

Adult↗

PubMed1998

[Effects of extremity cuffs against physiological changes induced by head-down bedrest].

-6 degrees head down bedrest (HDBR) 10d was used to simulate weightlessness. 12 volunteers were randomed into control group and cuffs group, with 6 in each group. Inflated cuffs on the upper part of thighs and arms were performed 12 h/d in cuffs group during bedrest. No countermeasures were applied in the control group. During head up tilt (HUT) +75 degrees 20 min orthostatic tolerance test after HDBR, 5 in control group became presyncopal, while only one in cuffs group. The study indicates that the use of inflated cuffs provides a protective effect against the cardiovascular deconditioning after bedrest.

Adolescent↗

PubMed1998

[Effect of +Gz-induced cerebral ischemia on the distribution of nitric oxide synthase in rabbit brain].

In order to study the effect of repeated short termed + Gz -induced cerebral ischemia on rabbit brain, rabbits were exposed to +4.0 Gz for 3 times (with 30 min interval in between) which caused the arterial pressure at eye level dropped to 0 kPa and lasted for 30 s. Changes of distribution of the nitric oxide synthase(NOS) positive neurons in rabbit brain were observed using the NADPH-diaphorase histochemical reaction. The results showed that NOS positive neurons in the parietal cortex, piriform cortex, hippocampus and dentate gyrus increased by 167%, 126%, 321%, 172% (P < 0.01) respectively, immediately after repeated + Gz exposures, as compared with those of controls. It still remained significantly more than that in controls (P < 0.01) 1 h and 6 h after exposure. It suggests that NO may have some effect on the neurons during cerebral ischemia.

Acceleration↗

PubMed1998

[Effect of noise on human mental rotation performance].

To investigate the effect of moderate level low frequency noise on human mental rotation performance, letter rotation and compass orientation tests were performed in 24 healthy young male subjects during 2 h exposure to 85-95dB (A), it was found that during 120 min exposure to noise of 85dB (A), the mean reaction time increased (P<0.05), performance of reaction time and total performance decreased (P<0.01) significantly as compared with control in letter rotation test, meanwhile, performance of reaction time and total performance at 120 min exposure were significantly higher than that at 30 min (P<0.05). During 120 min exposure to noise of 95dB (A), the mean reaction time increased (P<0.01), the performance of reaction time and total performance decreased (P<0.01) significantly as compared with control in compass orientation test, meanwhile, performance of reaction time at 120 min were significantly higher than that at 30 min(P<0.05). The results show that exposures to 85 dB(A) and 95 dB(A) noise for 2 h have certain effect on the performance of human mental rotation and may affect performance of complex tasks with a higher workload.

Adolescent↗