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Biomedical subjects

X Meng

Publications and source records attributed to X Meng.

At least 55 records · Page 3Linked to original sources
PubMed2001

[Significance on expressions of Annexin-I and its correlative gene proteins in endometrial hyperplasia, atypical hyperplasia and endometrial carcinoma].

OBJECTIVE: To investigate expression of Annexin-I in various endometrial lesions and its significance in differential diagnosis of endometrial borderline lesions. METHODS: We collected 37 specimens with different endometrial lesions, and reclassified them according to China and FIGO's standard, which included 12 cases of endometrial hyperplasia (EH), 10 cases of atypical hyperplasia (ATH) and 15 cases of endometrial carcinoma (EC). Immunohistochemical staining for AX-I, c-erbB-2, p53 protein, ER, PR, EGF and IGF were performed by LSAB. RESULTS: The results showed that for AX-I, 1 cases of EH was weakly positive and others were negative; 9 cases of ATH showed strong positivity in the cytoplasm and the cell membrane, and 1 weakly positive; 7 cases of EC were positive and 8 negative. c-erbB-2 was expressed in 9 cases of ATH and 1 was negative. Expressions of EGFR, ER and PR were strong in all cases, but IGFR was negative in almost all cases. P53 expression was higher in EC than in ATH. CONCLUSIONS: AX-I expression suggests that (1) AX-I protein may play an important role in the pathogenesis of cancer, the expression decreased and disappeared after malignant change. (2) High expression for AX-I can be used to differentiate ATH and EC. In addition, c-erbB-2 expression appeared to parallel the expression of AX-I in both ATH and EC, but in ATH it was higher than that in EC.

Annexin A1↗
PubMed2001

[The effect of human follicular fluid on mouse embryo culture].

OBJECTIVE: To evaluate the effect of human follicular fluid (HFF) on mouse embryo culture. METHODS: Compare the effects of HFF and serum as a protein supplement on the in vitro development of mouse embryos. Measure the concentration of the epidermal growth factor (EGF) in HFF and human serum. RESULTS: HFF significantly enhanced the developmental potential of mouse embryos in vitro, even in the presence of meiotic inhibitors. HFF significantly increased frequency of development from the 2-cell stage to the 8-cell stage (72.9%), blastocyst stage (50.9%) and hatching (26.3%), compared with human serum(48.0%, 24.5%, 6.9%, P < 0.05). There was higher concentration of EGF with an average of 0.50 microgram/L in HFF group compared with human serum (0.26 microgram/L, P < 0.05). CONCLUSION: Human follicular fluid is effective in increasing the developmental potential of mouse embryos in vitro.

Animals↗
PubMed2001

[Retrospective analysis of endometrial neoplasms treated by different therapeutic modalities].

OBJECTIVE: To compare the therapeutic effects of different remedies in patients with endometrial carcinoma. METHODS: Total of 386 patients with metracarcinoma underwent 3 different treatments: (1) operation only 145 cases; (2) operation and complemental radiotherapy 161 cases; (3) radiotherapy only 80 cases. Then they were followed up for 5 years and more. RESULTS: The 5-year survival rates of operation group were 78.9% (56/71), 61.0% (25/41) and 18.2% (6/33) in stage I, stage II, and stage III-IV respectively, for operation and complemental radiotherapy, they were 75.0% (33/44), 59.5% (44/74) and 48.8% (21/43), for radiotherapy, 34.8% (8/23), 18.8% (3/16) and 0.0% (0/41). There was no difference between operation group and operation plus radiotherapy in patients with stage I and stage II (P > 0.05). However the 5-year survival rates were significantly higher in operation plus complemental radiotherapy group and those only received operation in stage III stage IV patients (P < 0.001). And no matter in what stages, the therapeutic effect was worse in radiotherapy group than other two groups (P < 0.001). CONCLUSION: The remedies with operation as main measure are the best choice for metacarcinoma, radiotherapy merely is fit with those who can not be operated on.

Adult↗
PubMed2001

[Experimental study and application of extracellular matrix of conjunctiva].

OBJECTIVE: To investigate the characteristics and application of extra-cellular matrix (ECM) of conjunctiva. METHODS: Pieces of conjunctival ECM were made, and then the conjunctival defect was repaired with that in an experimental group. Control group 1 received the heterogeneous conjunctiva, and in control group 2, the refrigerated ECM was used for transplantation. All of them were photographed and examined by light microscope, electron microscope (EM), immunohistochemical examination and lymphocyte toxicity test. RESULTS: There were blood vessels growing into the grafts on the 3rd day in the experimental group. The grafts became mildly congestive and similar to normal conjunctival ones in the 4(th) week. But in control group 1, the grafts became white and necrotic in the second week; the conjunctiva was congestive, cicatricial and hyperplastic in the 4(th) week. Under the light microscope, the epithelium covered the most part of the region with the graft in the 2nd week, covered completely in the 4(th) week, and its appearance was as an approximately normal conjunctival epithelium in the experimental group. But the epithelium became ulcerative and a lot of lymphocytes infiltrated in the 2nd week in control group 1. Under the EM, the line of demarcation between the covering region of the regenerative conjunctival epithelium and the naked ECM was quite clear in the 1st week in the experimental group. And the ultrastructure of regenerative conjunctival epithelium was basically the same as an normal one in the 8(th) week. Both before and after transplantation, the immunohistochemical examinations verified that ECM was type I and IV collagen. The lymphocyte toxicity test showed that no obvious humoral immunoreaction existed. CONCLUSION: Conjunctival ECM has the characteristics of tissue activity and low antigenicity. It is an ideal conjunctival succedaneum in the plastic surgery of conjunctiva.

Animals↗
PubMed2001

[A discussion on diagnosis and typing of viral hepatitis].

OBJECTIVE: To bring forward a suggestion about clinical diagnostic standard and clinical typing for chronic and severe hepatitis. METHODS: To make a comprehensive study on clinical features and pathology of 895 cases of severe and chronic hepatitis, liver cirrhosis after hepatitis based on the viral prevention and control plan laid down in 1995. RESULTS: The chronic hepatitis can still be divided into mild, moderate and severe types clinically, but the PTA should be changed for normol-71, 70-61, 60-51, the A/G value for normal, 1.5-1.3, 1.2-1.0 respectively. ALT, BIL, alpha-globulin are kept unchanged. The albumin value can be cut out from the reference indexes of clinical typing for chronic hepatitis. Acute severe hepatitis can be divided into early stage (taking edema as the main type) and late stage (taking necrosis as the main type); subacute severe hepatitis can be divided into ascite type, coma type and mixed type; if those lacking of coma and ascite with PTA about 60%. 50% can be treated as earlier stage. Subacute and chronic severe hepatitis still can be divided into early, middle and late stages. The disease course of subacute severe hepatitis may prolong to six months. Chronic severe hepatitis can be divided into type B (typical chronic hepatitis type) type C (liver cirrhosis type) and type c (acute liver failure type developed from chronic hepatitis and viral carriers). CONCLUSIONS: The original procedure of 1995 are feasible on the whole.

Factor XI↗
PubMed2001

[A study on bacterial contamination of dental handpieces].

OBJECTIVE: The aim of this study is to evaluate the effects of different factors, including concentration of the bacterial suspension, number of stops set on handpieces, and different disinfectants, on bacterial contamination of handpieces and their clinical significance. METHODS: Bacterial contamination of 20 handpieces were analyzed in different concentration of bacterial suspension, number of stops set on handpieces and after using different out surface disinfectants. RESULTS: Statistical increment (P < 0.05) of handpieces inside contamination was observed relevant to increment of the bacterial suspension concentration. No statistical relevance was seen between handpiece inside contamination and the number of stops set on handpieces(P > 0.05). Disinfection with different disinfectants significantly decreased out surface contamination(P < 0.05), but no statistical change of bacteria (P > 0.05) was observed inside handpieces. CONCLUSION: As the concentration of bacterial suspension is the key factor affecting the inside contamination of handpieces, oral cavity cleanness is essential before dental therapy. The surface disinfection of handpieces is necessary after dental therapy, but cannot prevent cross-contamination between patients.

Cross Infection↗
PubMed2001

[The relationship between content of substance P, VIP in pharyngeal tissue and narrow pharyngeal cavity of patients with OSAS].

OBJECTIVE: To investigate the relationship between content of substance P, VIP in the pharyngeal tissue and narrow pharyngeal cavity of patients with OSAS. METHOD: By using semi-quantitative immunohistochemical method, resected pharyngeal tissue from 30 patients with OSAS and 12 normal health adult controls were investigated with rabbit anti-substance P and rabbit anti-VIP. RESULT: SP and VIP were detected in tribution within the epithelium or between epithelium cells, around the pharyngeal glands and gland ducts, around endothelium cells and smooth muscle of blood vessels. SP and VIP levels in pharyngeal tissue of the patients with OSAS were increased than those of the controls. CONCLUSION: Narrow of pharyngeal cavity with OSAS was relative to edema of pharyngeal tissue induced by increased SP and VIP in pharyngeal tissue. A neurogenic inflammation was one of the factors of OSAS.

Adult↗
PubMed2001

[Clinical observation on effect of electroacupuncture therapy in treating superficial tumor].

OBJECTIVE: To investigate the clinical effect of electroacupuncture therapy (EAT) in treating superficial tumors. METHODS: The healthy tissue was protected by insulation sleeve, and the platinum electrodes served as needles was inserted into the tumor and connected to an EAT instrument using galvanic current. The electric voltage applied was 6-8 V, the electric current was in a range of 40-80 mA, and 80-100 coulomb electricity for 1 cm diameter of tumor mass was administered. RESULTS: In the 320 cases, 123 were complete remission (CR), 129 partial remission (PR), 36 with their tumor shrinked by 1/4 and 32 with size of tumor unchanged. The total effective rate (CR + PR) was 78.7%. CONCLUSION: EAT shows good effect in treating superficial tumor and provides a new therapeutic means for the patients with tumor of unresectable or relapsed. It is a simple, convenient, safe and effective method with less injury and quick recovery.

Adolescent↗
PubMed2001

[An association study of histocompatibility leukocyte antigen-class II with Meniere's disease].

OBJECTIVE: To investigate the relation between histocompatibility leukocyte antigen (HLA)-class II DRB1 and Meniére's disease in Chinese. METHODS: Polymerase chain reaction-sequence specific primers (PCR-SSP) technique was used. HLA-class II allele distribution were measured in 60 patients with Meniére's disease, in comparison with those in 85 normal population. RESULTS: The results showed that the frequency of DRB1*09 allele was significantly lower in Meniére's disease patients than in those of controls (relative risk = 0.17, P < 0.01). CONCLUSION: HLA-DRB1*09 of the patients with Meniére's disease was significant low. It implied that DRB1*09 may be a protective gene for Meniére's disease.

Adolescent↗
PubMed2001

[Raman spectra of Cu/Zn superoxide dismutase and L-cysteine used as an electron transfer promoter].

In author's laboratory, it has been demonstrated with electrochemical techniques that L-cysteine can be used as an effective electron transfer promoter to accelerate the electron transfer process of Cu/Zn superoxide dismutase on gold electrode. In order to reveal the mechanism of this promotion, confocal microscopic Raman spectroscopic technique is employed here to obtain Raman spectra of solid state SOD and L-cysteine modified gold electrode. Moreover, Raman spectra of L-cysteine modified gold electrode with two different approaches are also obtained. Analysis and discussion for these Raman spectra are reported.

Cysteine↗
PubMed2001

[Effects of estradoil valerate on osteoporosis in ovariectomized rats].

OBJECTIVE: Compared with 17beta-estradiol, to evaluate the effects of estradiol valerate on osteopenia in ovariectomized rats. METHODS: Forty two six months old female Wistar rats were randomly divided into 5 groups performed ovariectomy (OVX) or sham-operation. (1) 6 weeks after OVX (Ovxb, n = 8): sacrificed at 6 weeks after OVX; (2) Sham ovariectomized (n = 8); (3) 14 weeks after OVX (Ovxe, n = 8); (4) 17beta-estradoil treated group (O + E, n = 9, with 17beta-estradiol 20 microg x kg(-1) x d(-1) Sc.); (5) Estradoil valerate treated group (O + EV, n = 9, with estradiol valerate 800 microg x kg(-1) x d(-1) po). Treatment started 6 weeks after OVX and lasted for 8 weeks. Histomorphometry analysis of tibia, peripheral quantitative computed tomography (pQCT) scanning of femur, bone biomechanical test in femur were performed. RESULTS: OVX induced osteopenia and increase of bone turnover. Compared with Ovxe, O + E and O + EV caused an evident reduction of urinary deoxypyridinoline/creatinine, a bone resorption marker, by 54.6% and 77.4% respectively (all P < 0.01). Both O + E and O + EV lowered the high level of eroded surface, mineral surface and bone formation rate induced by OVX. An increase of 122.3% and 119.7% in trabecular bone volume respectively in O + E and O + EV group, compared with Ovxe group. Microarchitecture of trabeculea also improved in those two groups. The trabeculae bone mineral density determined by pQCT were significantly increased in O + E and O + EV compared with Ovxe group (99.5% and 128.4% P < 0.01). Similarly, significant increases were found in cancellouse maximal load and canceallous stiffness of distal femur in O + E, but not O + EV. There was no significant difference in these changes between the group O + E and O + EV. CONCLUSION: Oral estradiol valerate performed effects similar to those of 17beta-estradiol Sc. in inhibiting bone turnover, protecting bone loss and increasing bone mineral density of trabecular bone.

Animals↗
PubMed2001

[Clinical effectiveness of electroacupuncture therapy in combination with invasive therapy for massive liver cancer].

OBJECTIVE: To investigate the clinical effectiveness of electroacupuncture therapy (EAT) in combination with liver artery intubation chemotherapy for massive liver cancer. METHODS: A total of 106 patients were divided into 3 groups. In group A, patients underwent EAT in combination with invasive therapy. In group B, patients received EAT alone. In group C, patients underwent invasive therapy of liver artery intubation chemotherapy. In groups A and B, subcostal oblique incision was performed to expose liver cancer, and electrodes were inserted into the tumor under direct vision. In group A, liver artery intubation was performed during operation. After operation, chemotherapy was given from the tube. Liver artery intubation chemotherapy was performed only in group C. RESULTS: The effective rate was 73.7% (28/38), 55.6% (20/36) and 28.1% (9/32) in groups A, B and C, respectively. CONCLUSIONS: The effect of electro acupuncture therapy in combination with liver artery intubation chemotherapy achieves the best results. Therefore, it is an effective therapy for massive liver cancer.

Adult↗
PubMed2000

A novel smad nuclear interacting protein, SNIP1, suppresses p300-dependent TGF-beta signal transduction.

Members of the transforming growth factor-beta superfamily play critical roles in controlling cell growth and differentiation. Effects of TGF-beta family ligands are mediated by Smad proteins. To understand the mechanism of Smad function, we sought to identify novel interactors of Smads by use of a yeast two-hybrid system. A 396-amino acid nuclear protein termed SNIP1 was cloned and shown to harbor a nuclear localization signal (NLS) and a Forkhead-associated (FHA) domain. The carboxyl terminus of SNIP1 interacts with Smad1 and Smad2 in yeast two-hybrid as well as in mammalian overexpression systems. However, the amino terminus of SNIP1 harbors binding sites for both Smad4 and the coactivator CBP/p300. Interaction between endogenous levels of SNIP1 and Smad4 or CBP/p300 is detected in NMuMg cells as well as in vitro. Overexpression of full-length SNIP1 or its amino terminus is sufficient to inhibit multiple gene responses to TGF-beta and CBP/p300, as well as the formation of a Smad4/p300 complex. Studies in Xenopus laevis further suggest that SNIP1 plays a role in regulating dorsomedial mesoderm formation by the TGF-beta family member nodal. Thus, SNIP1 is a nuclear inhibitor of CBP/p300 and its level of expression in specific cell types has important physiological consequences by setting a threshold for TGF-beta-induced transcriptional activation involving CBP/p300.

Amino Acid Sequence↗
PubMed2000

An improved method for the determination of green and black tea polyphenols in biomatrices by high-performance liquid chromatography with coulometric array detection.

Tea polyphenols are strong antioxidants and are believed to have beneficial health effects. However, the blood and tissue levels of these compounds are not well characterized because of a lack of suitable analytical methods for the biological resolution of these compounds. Previously, we developed methods for the analysis of three green tea catechins. Now we report an improved method for the measurement of the levels of the different catechins and theaflavins in biological fluids and tissues. The method includes digestion of the plasma, urine, or tissue samples with beta-d-glucuronidase and sulfatase, followed by extraction with ethyl acetate and subsequent separation by reversed-phase high-performance liquid chromatography (HPLC). The polyphenols are identified on the basis of their retention times, spectral analysis, and electrochemical behavior across an array of electrodes. In a single HPLC run, it is possible to determine the major catechins and theaflavins as well as some of the catechin metabolites. The detection limits for catechins and theaflavins are from 5 to 10 ng/ml of saliva, plasma, or urine.

Adult↗
PubMed2000

Regulation of cell fate decision of undifferentiated spermatogonia by GDNF.

The molecular control of self-renewal and differentiation of stem cells has remained enigmatic. Transgenic loss-of-function and overexpression models now show that the dosage of glial cell line-derived neurotrophic factor (GDNF), produced by Sertoli cells, regulates cell fate decisions of undifferentiated spermatogonial cells that include the stem cells for spermatogenesis. Gene-targeted mice with one GDNF-null allele show depletion of stem cell reserves, whereas mice overexpressing GDNF show accumulation of undifferentiated spermatogonia. They are unable to respond properly to differentiation signals and undergo apoptosis upon retinoic acid treatment. Nonmetastatic testicular tumors are regularly formed in older GDNF-overexpressing mice. Thus, GDNF contributes to paracrine regulation of spermatogonial self-renewal and differentiation.

Animals↗
PubMed2000

Abnormal expression of hepatoma specific gamma-glutamyl transferase and alteration of gamma-glutamyl transferase gene methylation status in patients with hepatocellular carcinoma.

BACKGROUND: Hepatoma specific gamma-glutamyl transferase (HS-GGT) bands were expressed in the development of hepatocellular carcinoma (HCC) and were associated with a high incidence of HCC diagnosis. The objectives of this study were to determine the levels of HS-GGT quantitatively in the sera of patients with different liver diseases. The methylational status of GGT gene CCGG sites was analyzed in hepatoma tissues. METHODS: The HS-GGT concentrations were quantitatively analyzed in the sera of 156 HCC patients and others with liver diseases or extrahepatic tumors. In 20 hepatoma tissues, the GGT enzyme proteins were purified, the activities of GGTs of different molecular form were examined, total RNAs were extracted and amplified by using a nested polymerase chain reaction (PCR) assay, and the methylational status of CCGG site (M3) in the 5'-noncoding region of GGT genes was investigated with the restriction enzyme Hpa II. RESULTS: Total GGT activities in patients with liver diseases and extrahepatic tumors were abnormally increased. The levels of serum HS-GGT were significantly elevated (P < 0.001) in the HCC group; the incidence of HS-GGT over 5.5 IU/L was 86% in HCC patients and less than 3% in patients with other diseases. From liver cancer to distal noncancerous tissues, an increasing tendency (P < 0.05) of total RNA concentrations was found; the frequencies of amplified fragment and hypomethylated M3 site of GGT genes were 100% and 75% in HCC, 85% and 55% in paracancerous tissues, and 75% and 50% in noncancerous tissues, respectively. An inverse correlation was found between methylational degrees of GGT genes and expression levels of GGT. CONCLUSIONS: The abnormal alteration of serum HS-GGT level is a sensitive tumor marker for HCC diagnosis or differentiation, and the overexpression of GGT in HCC may be related to the hypomethylational status of CCGG sites of GGT genes.

Adult↗
PubMed2000

Mechanisms of inhibition of carcinogenesis by tea.

Tea (Camellia sinensis) preparations have been shown to inhibit tumorigenesis at the initiation, promotion, and progression stages in different animal models. The anti-proliferative effects of tea polyphenols may be a key mechanism, especially in the NNK-induced lung tumorigenesis model with mice. Studies with cell lines have demonstrated that tea polyphenols inhibit cell proliferation and induce apoptosis. The effective concentrations used in these studies (20-100 microM) are usually higher than those observed in blood and tissues of humans and animals, which are in the low micromolar range. Glucuronide and sulfate conjugated and methylated catechins as well as ring fission products (due to intestinal microflora) have been observed in human plasma and urine. Purified green and black tea polyphenols inhibited the H-ras induced milogen-activated protein kinases, AP-1 activities, and the growth of 30.7b Ras 12 and BES21 cells. Among the catechins, both the galloyl structure on the B ring and the gallate moiety are important for the inhibition. Both (-)-epigallocatechin-3-gallate and theaflavin-3,3'-digallate inhibited the phosphorylation of c-jun and p44/42 (ERK 1/2). More mechanistic and human studies in these areas will help us to understand the possible inhibitory action of tea against carcinogenesis in humans.

Animals↗