Biomedical subjects

X Cao

Publications and source records attributed to X Cao.

At least 127 records · Page 7Linked to original sources

PubMed2000

Regulation of glial cell line-derived neurotrophic factor expression by electroacupuncture after transient focal cerebral ischemia.

The present study was designed to investigate whether electroacupuncture (EA) is able to regulate glial cell line-derived neurotrophic factor (GDNF) expression following transient middle cerebral artery occlusion (MCAO) using reverse transcriptase polymerase chain reaction and immunohistochemistry in rats. The results indicate that after 2 h MCAO, GDNF mRNA and immunoreactivity profoundly increased in peri-infarct cerebral cortex, with peaks at 2 h after reperfusion, then declined dramatically at 12 and 24 h after reperfusion. Although EA given immediatelly after MCAO couldn't elevate the peaks of GDNF expression, it obviously raised the GDNF mRNA and immunoreactivity levels at 12 h after reperfusion, delayed the declining trends of GDNF mRNA and immunoreactivity levels. These results suggest that EA could upregulate GDNF expression after ischemic insult, elongating the duration of upregulated GDNF expression. This may be one of the mechanisms of EA anti-ischemic injury by augmenting endogenous protective mechanism.

Animals↗

PubMed2000

Assessment of the bioavailability of rare earth elements in soils by chemical fractionation and multiple regression analysis.

The bioavailability of rare earth elements (REEs) in soils was evaluated, based on the combination of chemical fractionation and multiple regression analysis. REEs in soils were partitioned by a sequential extraction procedure into water soluble (F(ws)), exchangeable (F(ec)), bound to carbonates (F(cb)), bound to organic matter (F(om)), bound to Fe-Mn oxides (F(fm)) and residual (F(rd)) fractions. Alfalfa (Medicago Staiva Linn.) had been grown on the soils in a pot-culture experiment under greenhouse conditions for 35 days. The concentrations of REEs in fractions and plant were determined by inductively coupled plasma-mass spectrometry (ICP-MS). Chemical fractionation showed that (F(ws)) fraction of REEs was less than 0.1% and residual (F(rd)) was the dominant form, more than 60% in soils. Bioaccumulation of REEs was observed in Alfalfa. REE availability to the plant was evaluated by multiple regression analysis. F(ws), F(ec), F(cb) and F(om) fractions were significantly correlated with REE uptake by alfalfa. But the exchangeable Pr(F(ec)) was significantly correlated with Pr concentration in alfalfa. F(ec), F(cb) and F(om) greatly contributed to La and Nd bioavailability; F(ec) and F(om) to Ce, Gd and Dy; F(ec) and F(cb) to Yb; and F(ws), F(ec) and F(om) to total REEs. This meant that the bioavailability of different species of REEs varied with individual REE. The results of this study indicated that the sequential extraction procedure, in conjunction with multiple regression analysis, may be useful for the prediction of plant uptake of REEs from soils.

Biological Availability↗

PubMed2000

Relationship between feeding practices and weanling diarrhoea in northeast Thailand.

Diarrhoea is a major public health problem in Thailand. During November 1998-January 1999, a cross-sectional survey and a nested qualitative study were conducted to understand the relationship between feeding practices and weanling diarrhoea, and to describe the related local beliefs and practices in a subdistrict of northeast Thailand. A cluster-sampling method was used for selecting 156 weanlings aged 3-24 months. A structured interview was conducted with the main caregivers of these weanlings. The questionnaire used for the interview included items about feeding practices and diarrhoea-history of the weanlings in 2 months prior to the interview. Seven focus-group discussions with an opportunistic sample of the caregivers were held in the villages. A series of vignettes and unstructured questions were used for eliciting the local beliefs about weanling diarrhoea and its causes. Thirty-six (23%) of the 156 weanlings had diarrhoea in 2 months prior to the interview. The factors that were significantly related to reported weanling diarrhoea included consumption of unboiled water by weanlings (OR = 10, p = 0.03), not covering perishable foods (OR = 3, p = 0.02), and washing feeding utensils of weanlings without dishwashing detergent (OR = 3.1, p = 0.02), 'Su' and 'tongsia'--two common local terms--were used for describing different types of weanling diarrhoea. Many caregivers considered 'su' a natural occurrence in a child's development. The results suggest that some poor feeding practices may contribute to the higher risk of weanling diarrhoea in northeast Thailand. Some local beliefs about weanling diarrhoea may mask the true causes, and mislead messages about its prevention.

Adolescent↗

PubMed2000

Dysfunction of microvascular endothelial cells induced by tumor necrosis factor (TNFalpha): cellular and molecular mechanism.

The dysfunction of rat pulmonary microvascular endothelial cells (RPMVEC) induced by tumor necrosis factor alpha (TNFalpha) was investigated in cell culture. The TNFalpha concentrations added into culture were 1000-5000 u/ml. The study was done at different steps as follows: (1) cell proliferation dynamic, (2) coagulation and anti-coagulation, (3) adhesive molecule, (4) nitric oxide (NO), (5) oncogens, and (6) apoptosis. It was concluded that attention should be paid to the metabolic disorder and dysfunction of RPMVEC induced by TNFalpha which can not be found easily according to the morphological changes. This might be the common pathway in the pathogenesis of some diseases related to TNFalpha.

Animals↗

PubMed2000

[A prospective study of posttransfusion hepatitis B virus infection].

OBJECTIVE: To understand the status of HBV posttransfusion infection after blood HBsAg screening of the blood donors. METHODS: Serum samples of blood recipients and donors were detected for HBV-M and HBV DNA by ELISA technique and polymerase chain reaction respectively. RESULTS: There were 326 sera positive for HBV-M and 57 for HBV DNA in 583 blood donors' sera. 39 sera were positive for HBV-M and 23 positive for HBV-DNA in 136 sera of blood recipients, the positive seroconversion rates were 28.68% and 16.9% respectively. CONCLUSIONS: There is high incidence of HBV infection in blood donors though they have been screened for HBsAg. The posttransfusion HBV infections are still occurring, therefore, the blood donors should be strictly tested for HBV-M. If conditions are possible, the HBV DNA had better been screened.

Adolescent↗

PubMed2000

[The effects on melanoma and immunological mechanism of human interferon-alpha gene therapy by fibroblasts].

OBJECTIVE: To establish a model of fibroblast cell-mediated human IFN-alpha gene therapy for anti-melanoma. METHODS: BMGNeo-IFN-alpha DNA was transferred into NIH3T3 fibroblasts by the liposome method. The clone secreting the highest level of IFN-alpha was selected and implanted to mice intraperitoneally. RESULTS: From 12 hours after implantation, IFN-alpha activity could be detected in serum of the animal and was sustained for a long time. We used the model to treat the nude mice inoculated with melanoma and found that the growth of M21 cells was inhibited obviously. CONCLUSIONS: The results demonstrated that fibroblasts could successfully transfer and express hIFN-alpha gene in vivo and the fibroblast cell-mediated gene therapy could be used to treat human melanoma.

3T3 Cells↗

PubMed2000

Embolic events in 93 elderly Chinese patients with atrial fibrillation.

OBJECTIVES: To evaluate the prevalence of embolic events and relevant factors in elderly Chinese patients with atrial fibrillation(AF), and to provide evidence on ways to prevent embolic events. METHODS: Autopsy data from ninety-three continous elderly Chinese patients with AF were analysed. The incidence of embolic events and its relationship to underlying disease, pathologic changes in the heart, and other clinical characteristics were examined. RESULTS: Embolism were observed in 27 of 93 cases, with an incidence of 29.03%. The incidence of embolic events was higher in elderly patients with rheumatic heart disease than those with coronary artery disease, hypertensive myocardiopathy and heart diseases. Patients with chronic AF, with a course of AF > or = 3 years, and those with heart failure or diabetes had a higher incidence of embolic events than those without these complications. There was significant difference in incidence between paroxysmal and chronic AF. Patients with left atrial or ventricular enlargement, mural thrombosis in cardiac chambers, valvular calcification and valvular vegetation also had a higher incidence of embolic events. Oral dipyridamole (75-150 mg/d) or aspirin (50-150 mg/d) showed no definite effects in preventing embolism in some patients. CONCLUSIONS: There was a high incidence of embolic events in elderly Chinese patients with AF. Anticoagulation therapy should be provided to the elderly patients with AF, especially to the patients with risk factors for embolism.

Aged↗

PubMed2000

Gene polymorphism in apolipoprotein E and presenilin-1 in patients with late-onset Alzheimer's disease.

OBJECTIVE: To evaluate the association of apolipoprotein E (apoE) and presenilin-1 (PS-1) gene polymorphism with late-onset Alzheimer's disease (AD). METHODS: A case-control study was undertaken to detect the polymorphism of apoE and PS-1 by polymerase chain reaction and digestion with the endonucleases of BspL I, Hha I and BamH I. RESULTS: The frequencies of apoE epsilon 3/4 genotype and epsilon 4 allele in late-onset AD (n = 42) were significantly higher than those of age-matched controls (P < 0.05). The frequencies of the apoE intron 1 enhancer (IE1) G/G genotype and G allele in late-onset AD were also significantly higher than those in controls (P < 0.05). The frequencies of the PS-1 1/1 genotype but not the 1 allele in AD were significantly higher than those in controls (P < 0.05). The apoE epsilon 4 allele was associated with a tripling of risk for late-onset AD compared with that with no epsilon 4 allele (odds ratio: 2.932). Homozygosity of the G allele in IE1 and 1/1 genotype in PS-1 was associated with a doubling of risk for late-onset AD, and odds ratios were 2.223 and 2.066, respectively. When the apoE epsilon 4 was controlled, the association between the IE1 G/G genotype AD was no longer statistically significant (P > 0.05). We sequenced the exon 4 of apoE in patients with late-onset AD, and found no other genetic polymorphism or mutation except for apoE epsilon 4 and IE1 G alleles associated with AD. CONCLUSION: apoE epsilon 4 gene appears to be the strongest gene risk factor for late-onset AD and its apparent association between the IE1 G/G genotype and late-onset AD is a consequence of the association between the epsilon 4 and IE1 G/G genotype. The PS-1/1 genotype is weakly associated with late-onset AD.

Aged↗

PubMed2000

Macrophage activation of lymphoma-bearing mice by liposome-mediated intraperitoneal IL-2 and IL-6 gene therapy.

OBJECTIVE: To investigate the antitumor mechanism of interleukin-2 (IL-2) and interleukin-6 (IL-6) gene therapy. METHODS: Liposome encapsulated IL-2 DNA and IL-6 DNA were intraperitoneally (i.p.) injected into mouse lymphoma cell line (EL-4) lymphoma-bearing mice. Macrophage function (M phi) from the mice was assessed. RESULTS: Cytotoxicity, major histocompatibility (MHC) II expression and IL-1 and TNF secretion of the macrophages all augmented after i.p. injection of liposome encapsulated IL-2 DNA or IL-6 DNA. More efficient activation of macrophages was observed in mice treated with liposome encapsulated IL-2 DNA than IL-6 DNA. IL-2 gene therapy combined with IL-6 gene therapy showed the maximal activation of macrophages in the lymphoma-bearing mice. CONCLUSION: IL-2 and IL-6 gene therapy can relieve the suppression of macrophages of the lymphoma-bearing mice, and efficiently activate the antitumor immune responses.

Animals↗

PubMed2000

Interventional treatment of huge hepatic cavernous hemangioma.

OBJECTIVE: To study the methods of interventional treatment of huge hepatic cavernous hemangioma (HCH). METHOD: A total of 14 patients with HCH were treated with lipiodol-ultrafluid (10-15 ml), bleomycin A (PYM 16-32 mg), and gelatin-sponge particles. RESULTS: DSA hepatic arteriography showed multiple vascular lakes in the early arterial phase, so-called "to hang the fruits on the branches", which persisted for a long time. CT scan showed a significant reduction in tumor size in 8 of the 14 patients after the treatment. CONCLUSION: Embolization with lipiodol-ultrafluid, PYM and gelatin sponge particles is one of the best methods for the treatment of HCH.

Adult↗

PubMed2000

Suppression of induced atherosclerosis in h-apo AI transgenic mice by overexpression of human apo AI in the aortic wall.

OBJECTIVES: To investigate the inhibitory effect of expressed human apolipoprotein AI (h-apo AI) and high density lipoprotein (HDL) on atherosclerosis development in transgenic mice, and cultivation of smooth muscle cells isolated from the aortic wall of transgenic mice that are able to produce human apo AI in vitro. METHODS: Both h-apo AI transgenic mice and normal C57 mice were fed with either a regular chow or a high-fat diet containing 5% pork lard, 1.25% cholesterol and 0.25% sodium cholate for 14 or 24 weeks respectively. Human apo AI mRNA were detected by Northern blot. Plasma apo AI levels were measured using a radio-immuno-diffusion assay, and plasma lipid levels were measured using a colorimetric assay. Image analysis was performed in order to quantify the fatty streak areas stained with oil red O. In addition, smooth muscle cells isolated from the media layer of the aortic wall of h-apo AI transgenic mice were cultured for the detection of human apo AI produced. RESULTS: Higher levels of h-apo AI mRNA were found in liver, small intestine, kidneys and aortae in transgenic mice than in the controls all on a high-fat diet. The transgenic mice had an increased level of serum apo AI and HDL-cholesterol and the fatty streak area counted at the aortic sinus was approximately 5-fold less in the transgenic mice after feeding with a high fat ration, particularly after 24 weeks. SMC isolated from the transgenic mice aortae were cultivated and able to express h-apo AI mRNA and its related protein. CONCLUSION: Elevation of h-apo AI and HDL in serum and aortic wall of the transgenic mice has a remarkably inhibitory effect on the development of experimental atherosclerosis.

Animals↗

PubMed2000

[Comparison between therapeutic effect of Risperidone in treating different traditional Chinese medicine syndrome types of first-episode schizophrenia].

OBJECTIVE: To study the therapeutic effect, side effects and cognize improvement of Risperidone in treating different TCM Syndrome-types of first-episode schizophrenia. METHODS: Applying Risperidone to treat first-episode schizophrenics who were divided into Phlegm-Dampness type, Phlegm-Fire type and other types in TCM, and observing them with PANSS, TESS and Wisconsin Card Sorting Test (WCST). RESULTS: It is important to assess the therapeutic effect of patient with Fire Syndrome or without. Insomnia is the most prevalent side effect, while akathisia in Phlegm-Fire type is the most serious side effect, cognition deficiency in Phlegm-Dampness type is the most serious before treatment, and reduction of total card number of WCST in Phlegm-Fire type is significant after treatment (P < 0.05). CONCLUSION: It is the best way to use Risperidone combined with TCM Syndrome Differentiation so as to elevate the efficacy.

Adolescent↗

PubMed2000

[Relationship between tumor suppressor gene p16 and Rb and early diagnosis of lung cancers].

OBJECTIVES: To study the incidences and mechanisms of tumor suppressor gene p16 and Rb inactivation in lung cancers, and to investigate their relation to biological characters, clinical pathological diagnosis and gene classification diagnosis of lung cancers. METHODS: Immunohistochemistry, double in situ hybridization, PCR, PCR-SSCP and sequencing were applied to study the changes of p16 and Rb genes in 106 lung cancers and 23 lung tissues of benign diseases. RESULTS: Total expression rates of p16 and Rb proteins and mRNAs in lung cancers were lower than those in normal lung tissues and benign lung diseases, and they were specially related to histological type, metastasis and clinical stage of lung cancers. In stage I and II lung cancers, the obvious inactivation of tumor suppressor gene p16 or Rb was examined (32.6% or 28.3%); p16 inactivation was detected mainly in non-small cell lung cancers, and Rb inactivation mainly in small cell lung cancers. There were three mechanisms of homozygous deletions, methylations and mutations for p16 gene inactivation. The deletion rate of p16 exon1 and/or exon2 was 25.8%, mainly took place in p16 protein negative cases of non-small cell lung cancers. 15 cases (16.9%) took part in methylations on SmaI sites of CpG island of p16 gene. PCR-SSCP and sequencing showed that 9 cases had p16 gene mutations. CONCLUSIONS: p16 and Rb genes may play important roles in genesis and progression of lung cancers. Inactivation of p16 or Rb gene may be is an early link of lung canceration, that is very important for early diagnosis of lung cancers. A new gene classification model for lung cancer diagnosis would be set up based on the research of p16 and Rb genes.

Adolescent↗

PubMed2000

[CDKN2/p16 gene cloning and its probe preparation and application in lung cancer].

OBJECTIVES: To clone CDKN2/p16(INK4a) gene, prepare its probe, and to study the change of CDKN2/p16(INK4a) gene in lung cancers. METHODS: Total RNA of normal lung tissue was extracted, CDKN2/p16(INK4a) gene cDNA synthesized, and CDKN2/p16(INK4a) gene recombinant vector, constructed. Southern blot was used to study CDKN2/p16(INK4a) gene in 46 cases of lung cancers, 3 cases of normal lung tissues, 6 cases of lung tissues near cancer, and 3 cases of lymph nodes with lung cancer metastasis. RESULTS: Cloned CDKN2/p16(INK4a) cDNA was proved by enzyme digestion and sequencing. Southern blot showed 4.3 kb band in normal lung tissues and lung tissues near cancers, and deletion of CDKN2/p16(INK4a) gene in cancer tissues and lymph nodes with lung cancer metastasis, with a deletion rate of 17.4% (8/46). CONCLUSION: CDKN2/p16(INK4a) gene may play a role to some extent in progression of lung cancers.

Blotting, Southern↗

PubMed2000

Relations of tumor suppressor gene p16 and RB to early diagnosis of lung cancer.

OBJECTIVES: To study the incidence and mechanism of the tumor suppressor gene p16 and RB inactivation in lung cancer, and to investigate their relations to biological characteristics, clinical pathological diagnosis and gene classification. METHODS: Immunohistochemistry, double in situ hybridization, PCR, PCR-SSCP, and sequencing were used to study the changes in the p16 and RB genes in 106 patients with lung cancer. The specimen of normal lung tissue from the patients with lung cancer and specimens of the 23 patients with benign lung diseases were studied in contrast to those of the same patients. RESULTS: The total expression rate of the p16 and RB genes in the lung cancer tissues of the 106 patients was lower than that in normal lung tissues and tissues of benign lung diseases and was specially related to histological type, metastasis, and clinical stage of lung cancer. In stage I and II lung cancer, the obvious inactivation rate of the tumor suppressor gene p16 or RB was 32.6% or 28.3%. The p16 inactivation appeared largely in non-small cell lung cancer (50.1%), and the RB inactivation largely in small cell lung cancer (88.2%). Homozygous deletion, methylation, and mutation were three mechanisms for the p16 gene inactivation. The deletion rate of the p16 exon 1 and/or exon 2 was 25.8% in the patients with non-small cell lung cancer. Fifteen patients (16.9%) showed methylation at the SmaI sites of CpG island of the p16 gene. PCR-SSCP and sequencing revealed p16 gene mutation in 9 of the 106 patients with lung cancer. CONCLUSIONS: The p16 and RB genes may play an important role in genesis and progression of lung cancer. The inactivation of the p16 or RB gene may be an early sign of lung canceration, that is important for the early diagnosis. A new gene classification model for lung cancer diagnosis would be set up based on the research of the p16 and RB genes.

DNA Methylation↗

PubMed2000

[Influence of the administrators of family planning on the spread of norplant in countryside of Sichuan].

The purpose of the study was to understand the family planning administrators' knowledge of Norplant and their fluence on the spread of Norplant in countryside of Sichuan. 156 administratoras were surveyed. It was found that most of the administrators worked hard on education, propagation, organization and management of using Norplant, and they recognized the contraceptive efficacy of Norplant. However, the educational level of the administrators was generally low. They were short of the training on Norplant related knowledge(training rate was only 36.5%). The degree of the users' satisfaction and the administrators' knowledge on Norplant varied between areas. The result indicated that the basic quality of the administrators and their knowledge of Norplant were influences on the spread of Norplant in the countryside of Sichuan. Soit is very important to improve the basic quality and knowledge of the administrators of family planning.

Adolescent↗

PubMed2000

[Establishment of rat submandibular gland squamous cell carcinoma induced by DMBA].

OBJECTIVE: To study carcinogenesis and development of salivary gland tumor and establish an animal model of submandibular gland (SMG) tumor. METHODS: Histopathological study during carcinogenesis in rat SMGs using (9,10-dimethyl-1,2-benzanthracene (DMBA) was evaluated. A total of 50 male and female Sprague-Dawley (SD) rats of 8 weeks old and 180-200 g weight were obtained from the Animal Center of Henan Medical University. Under pentobarbital sodium anesthesia, the left SMGs were exposed by surgical procedure. A sponge pellet (1.0 mm x 1.0 mm x 1.0 mm, made by authors) was used as the carrier of the carcinogen. The sponge containing 2% DMBA (Fluka, Switzerland)/acetone solution was implanted into the glandular tissue of the left SMGs. Four rats (2 males and 2 females) were killed after every 2 weeks of the DMBA/sponge implantation. The same method of sponge implantation without DMBA was used at the right side of SMG as a control. All rats left were killed after 20 weeks. The SMGs were fixed in 10% formalin buffer solution for 24 hours, and embedded in paraffin, then 4 microns-thick sections were made for histopathological study. RESULTS: The earliest tumor occurred after 4 weeks of implantation of sponge, a total of 21 lateral tumors were induced (10 females, 11 males). There was no tumor found in the controlled SMG. The peak time of tumor genesis was after 8-12 weeks of implantation, all tumors induced were squamous cell carcinomas(SCCs). The induced tumors grew slowly below the mandibles of rats, which were present as nodular masses without capsules, and the borders were not clear. They were slightly hard when palpated. The process of carcinogenesis can be described as following: squamous metaplasia of cyst-like structures occurred, then SCCs were induced and invaded surrounding tissues. No metastasis was observed in regional lymph nodes and other organs. CONCLUSION: SCCs of SMG can be induced by implantation of DMBA. The present study supports the conclusion that all duct segments undergo squamous metaplasia, and therefore may participate in the genesis of neoplasia during experimental carcinogenesis.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed2000

[Vitrectomy combined with intraocular lens implantation for 103 selected cases of complicated ocular trauma].

PURPOSE: To observe the visual outcome of vitrectomy combined with intraocular lens (IOL) implantation in one operation for patients with complicated ocular trauma. METHODS: Clinical records were retrospectively reviewed in 103 patients with complicated ocular trauma (104 eyes) who underwent vitrectomy combined with IOL implantation in one operation. RESULTS: The series of cases included 35 patients with intraocular foreign body (IOFB), 37 with penetrating injury, 9 (10 eyes) with explosive injury but without IOFB, and 22 with blunt trauma. Preoperatively, visual acuity was no-light-perception to counting fingers in 88 eyes (87.1%) of 100 patients (101 eyes). Visual acuity improved in 94 eyes (93.1%) including 74 eyes (73.3%) with 0.1-1.5 postoperatively. Retinal detachment occurred in one eye during follow-up and cured with pars plana vitrectomy. CONCLUSION: Vitrectomy combined with IOL implantation in one operation can be a safe, fast and effective approach for visual recovery in selected patients with complicated ocular trauma.

Adolescent↗