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Biomedical subjects

X Chen

Publications and source records attributed to X Chen.

At least 811 records · Page 45Linked to original sources
PubMed1999

[Affect of insulin-like growth factor I and estradiol on the growth of uterine leiomyoma].

To study roles of insulun-like growth factor 1(IGF-I) and estradiol(E2) in the growth of leiomyoma. Protein expressions of IGF-I receptor(IGF-I-R), estrogen receptor(ER), and cell proliferation associated nuclear antigen(ki-67) were analysed by streptavidin-peroxide method in 40 cases. Serum level and local concentration of IGF-I were determined by immunoradiometric assay(IRMA) in 20 cases. Serum level of estradiol was determined by radioimmunoassay in 20 cases. Twenty normal fertile women were studied as control. Protein expressions of IGF-I-R and ER in uterine leiomyoma were significantly higher than in myometrium(P < 0.05); and local concentration of IGF-I positively correlated with ki-67 (r = 0.6513, P < 0.05); and expression of estrogen receptor. The serum levels of IGF-I and E2 had no significant difference between leiomyoma patients and normal women. IGF-I and E2 promote the growth of leiomyoma and IGF-I may act as a mediator of estrogen.

Adult↗
PubMed1999

[Inhibition of glutamate uptake in rat brain synaptosome by methylmercury].

The effect of methylmercury on the glutamate uptake in rat brain synaptosomes were studied in vitro by using a high affinity uptake test. The result showed that methylmercury(1 x 10(-9) -1 x 10(-4) mol/L) could decrease 3H-L-glutamate uptake in rat cerebral cortex, hippocampus, striatum and cerebellum synaptosome by 0.7%-74.4%, 7.5%-91.1%, 1.4%-76.6% and 4.4%-77.0%, respectively, in a dose-dependent manner, and their IC50 were 7, 9, 3.6, 2.2 and 4.3 x 10(-6) mol/L, respectively. It suggested that methylmercury could obviously inhibit glutamate uptake in the synaptosomes of rat brain.

Animals↗
PubMed1999

[Time-effect relationship between the positional microinjection of HCY-2 gene and the neural tube teratogenesis of chick embryos].

The time-effect relationship between positional transferred novel gene(HCY-2) and neural tube teratogenesis, and their possible mechanisms were studied. An eukaryotic expressing vector which containing whole-length HCY-2 cDNA was microinjected into chick embryos in culture at days 0, 1 and 2 (approximately Hamburger-Hamilton stages 1, 6 and 12) mediated by lipofect AMINE reagent. The techniques of RT-PCR, immunohistochemical staining, scanning electron microscope(SEM) and transmission electron microscope (TEM) were used to investigate the expression and distribution of HCY-2 mRNA with its coding product and dysmorphogenesis of the neural tube at 96 h (approximately stage 22). Neural tube defects (NTDs) were discovered in every transferred gene group, only the day 1 embryos which positional site injected was the area pellucida of head, however, the rate of NTDs was the highest (35.3%). There was an obvious time-effect relationship. The phenotypes of NTD were encephalocele, anencephaly, spina bifida and microcephaly. The embryos with transferred gene could express HCY-2 mRNA and its coding product, and the HCY-2 protein mainly distributed in embryonic brain cells as compared to controls. It was found that HCY-2 gene could result in abnormal ultrastructure at the surface and inside of cells under SEM and TEM. It has been observed apoptosis at the sites with NTDs. It is concluded that HCY-2 gene may be a new genotoxic factor, which plays an important role in the mechanisms of neural tube teratogenesis during the early developing stage of embryos.

Animals↗
PubMed1999

[Genotoxicity and lipid peroxidation caused by organic extracts of chlorinated drinking water in rats and HepG2 cells].

The genotoxic effects of chlorinated drinking water(CDW) extracts were examined in human HepG2 hepatoma cells, liver cells and polychromatic erythrocytes (PCEs) of bone marrow of Wistar rats by using in vivo and in vitro micronucleus(MN) test and single cell gel electrophoresis (comet assay). The influence of CDW on the lipidperoxidation (LPO) in blood and tissue of rats was also studied. The results indicated a significant increase of the frequencies of MN in PCEs at the low concentration of CDW and in HepG2 at the high concentration of CDW. The increased DNA breakage caused by CDW was observed in rat liver cells and in HepG2 cells by using comet assay. The levels of malon dialdehyde(MDA) were significantly increased almost in all animals and in all organs tested. A dose-dependent increases of MDA were observed in rat liver. It was demonstrated that CDW extracts caused genotoxic and oxidative damage on animals.

Animals↗
PubMed1999

[Effects of HCY-2 gene transfer on the development of chick neural tube].

In order to explore the relationship between novel gene HCY-2 and neural tube defects (NTDs) and to investigate whether HCY-2 gene was genotoxic, a mammalian expression vector containing HCY-2 cDNA (2014 bp) was transferred into chick fertilized ovum by using lipofectin reagent, then the biological effects of HCY-2 gene on embryos in culture for 3.5 days were observed. Western blotting and immunohistochemistry were used to analyse the expression and distribution of HCY-2 after gene being transferred. HCY-2 gene (5-20 micrograms/chick ovum) could induce NTDs in organogenesis period. Western blotting and immunohistochemical staining showed that HCY-2 protein could be greatly expressed by day 3.5, the time which NTDs developed, with stronger staining at the site of embryonic brain as compared with controls. Under electron microscope, it was observed that HCY-2 gene could damage embryonic cellular ultrastructures and cause excessive apoptosis of neurocytes. These findings suggested that HCY-2 gene with its product was dysmorphogenic to the neural tube, might be a genotoxic factor or teratogenic agent and should be responsible for chick NTDs and probably human NTDs as well.

Animals↗
PubMed1999

[Endogenous protective effects of superoxide dismutases on infectious brain injury in rats].

We studied the alterations of MDA and three forms of SOD activities such as T-SOD, CuZn-SOD, and Mn-SOD in rat cerebral tissues injected by bordetella pertussis (BP) to elucidate protective mechanism of SOD against the infectious brain injury. The results were that water content(WC), Evans blue content(EB), MDA, and Mn-SOD activities in 4 h and 24 h BP-treated groups increased and T-SOD and CuZn-SOD decreased compared to corresponding normal saline(NS)-treated groups, respectively(P < 0.01); MDA increased and had a positive correlation with WC and EB in 4 h BP treated group (r = 0.9650, r = 0.9441, P < 0.01, P < 0.01, respectively); Mn-SOD activities were elevated and had a negative correlation with WC, EB, and MDA (r = -0.8650, r = -0.9021, r = -0.9346, P < 0.01, P < 0.01, P < 0.01, respectively) in 24 h BP-treated group. The results suggest that the increase of component Mn-SOD activities may play an important role in vivo endogenous protective mechanism against delayed infectious brain injury.

Animals↗
PubMed1999

[Ilio-inguinal-hypogastric vascular network skin flap with common pedicle in the treatment of degloving injury of multiple fingers].

OBJECTIVE: In order to solve the difficult problem of one-stage repair of degloving injury of multiple fingers, the common pedicled ilio-inguinal-hypogastric subdermal vascular network skin flap was designed and the multi-lobes skin flap was performed subsequently. METHODS: From 1993 to 1996, there were 5 cases with degloving injuries of multiple fingers were treated by this flap. There were 2 males and 3 females and the age ranged from 7 to 19 years old. RESULTS: After operation, the pedicles of the flap was detached between 12 to 16 days and all of the flaps survived completely. Patients were followed up for 6-18 months. After repair, the contour and skin colour of the digits were excellent, and the motion of the interphalangeal joints and skin sensation were good. CONCLUSION: The conclusion was as follows: The newly designed skin flap was characterized by the advantages of duration of treatment being short, excellent contour and more rapid recovery of function. It could be used for one-stage repair of degloving injury of multiple fingers.

Adolescent↗
PubMed1999

[Application of sartorius muscle in the quadricepsplasty].

OBJECTIVE: Extension stiffness of knee joint is always treated by the quadricepsplasty, but the main deficiency of this method is that patient feels weakness of lower limb and easily kneels down. The aim of this article is to explore the method to resolve the complications after quadricepsplasty. METHODS: Since 1978 to 1997, on the basis of traditional procedures of quadricepsplasty, sartorius muscle was used to reinforce the extension of knee joint. The lower 2/3 of sartorius muscle was fully dissociated only with its insertion intact. A tendon-periosteal-bone flap, about 2 cm in width, was managed on the anterior surface of patella, with its pedicle on the medial edge of patella. The tendon-periosteal-bone flap was used to fix the dissociated sartorious into patella to reinforce the extension of knee joint. The very lower part of sartorius was mainly aponeurosis, with the help of an aponeurosis bundle of iliotibial tract, it was fixed into the insertion of patellar ligament, through a bony tunnel chiseled adjacent to the insertion of patellar ligament. By now the movement of knee joint extension was strengthened by the transferred sartorius muscle. Postoperatively, every patient was required to extend and flex knee joint actively and/or passively. Altogether 12 patients were treated, 9 of them were followed up with an average of 14 months. RESULTS: The average movement was increased from 15 degrees to 102 degrees, and the average myodynamia was improved from grade II to grade IV. CONCLUSION: Traditional quadricepsplasty co-operated with transfer of sartorius muscle can strengthen the myodynamia of knee joint extension. It is simple method and can really achieve good function.

Adolescent↗
PubMed1999

[Morphological studies on seeds from 5 species of medicinal Rhododendron].

OBJECTIVE: To provide a scientific evidence for the identification of Rhododendron species. METHOD: Investigation of the seed form of 5 species of Rhododendron was done by electronic microscope scanning. RESULTS: R. simsii belongs to the wingless type, and R. augustinii, R. decorum, R. delavayi and R. discolor belong to the winged type. CONCLUSION: The 5 species of medicinal Rhododendron can be distinguished according to such features as the form, wing and rib of seeds.

Microscopy, Electron, Scanning↗
PubMed1999

[Hepatoprotective effect of several constituents of Lonicera fulvotomentosa hsu et S. C. cheng, and L. macranthoide Hand.-Mazz. on CC1(4) and D-galactosamine induced liver injuries in mice and rats].

OBJECTIVE: To study the hepatoprotective effect of several constituents of Lonicera fulvotomentosa and L. macranthoide on CC1(4) and D-Galactosamine induced liver injury in mice and rats. METHOD: Mice and rats were given s.c. several constituents of L. fulvotomentosa and L. macranthoide, sGPT, hepatic triglycerides(TG) and malondialdehyde (MDA) were determined. RESULTS: All the compounds reduced the rise of sGPT and TG induced by CC1(4) and D-Galactosamine. Hepatic MDA formation caused by CC1(4) was also significantly decreased. CONCLUSION: Several constituents of L. fulvotomentosa and L. macranthoide are effective in decreasing CC1(4) and D-Galactosamine-induced liver injuries, and this effect appears to be due to the decrease of lipid peroxidation of CC1(4).

Alanine Transaminase↗
PubMed1999

[Relationship between expression of estrogen receptor progestrone receptor and the biological characteristics of nasopharyngeal carcinoma].

OBJECTIVE: To Clarity the relationship between the expression of the estrogen receptor (ER), progestogen receptor (PR) and the biological characteristics of nasopharyngeal carcinoma (NPC). METHOD: The immuno-histochemical LSAB method was used to analyse the ER and PR in paraffin section specimen of 71 cases of nasopharyngeal carcinoma. CT scaning and clinic presentation were also put into consideration. RESULT: The expression of ER with (-), (+), (++) and (+++) in 71 cases were: 4(5.63%), 19(26.76%), 27(38.03%) and 21 (26.76%), respectively. The expression of PR with (-), (+) and (++) in 71 cases were: 41(57.75%), 29 (39.44%) and 2(2.82%), respectively. The encroaching of tumor to the tissue of parapharynx, the metastasis rate of lymphonode and clinic stage were related to the expression of ER (P < 0.01). The encroaching of tumor to the tissue of parapharynx, the metastasis rate of lymphonode were also assciated with the expression of PR (P < 0.05). CONCLUSION: NPC is a tumor of hightly expression of ER and PR. The positive intensity of ER and PR were associated with the encroaching extent of NPC, and the metastasis rate of lymphonode. It is significant to detarmine ER and PR of NPC in assessing the biological characterisitics of NPC and predicting the prognosis of NPC. It also suggests that the endocrine therapy can be put into consideration.

Adult↗
PubMed1999

[Diagnostic value of ultrasonography in cervical lymph node metastasis].

OBJECTIVE: To research the accuracy of ultrasonography in the diagnosis of cervical lymph node metastasis and the value of that of cervical lymph node occult metastasis. METHOD: Fifty-five patients(61 sides) operated by neck dissection were double-blindedly studied by preoperation palpation and ultrasonography comparing with postoperating pathological examination. RESULT: Fifty-two sides were confirmed to be pathology lymph node metastasis from 61 sides. 40 and 48 sides were checked out by palpation and ultrasonography, respectively. The sensitivity, specificity and accuracy of palpation and ultrasonography were 76.9% and 92.3% (P < 0.05), 77.8% and 88.9%(P > 0.05) and 77.0% and 91.8%(P < 0.05), respectively. Six sides were checked out by ultrasonography (occult metastasis) in 12 sides of palpation negative. CONCLUSION: The accuracy of ultrasonography was prior to that of palpation in examining cervical lymph node metastsis. Ultrasonography could check out about half occult metastasis and should be regarded as a routine examining items in diagnosing cervical lymph node metastasis.

Adult↗
PubMed1999

[A comparative study of different neuromuscular pedicle embedded in posterior cricoarytenoid muscle].

OBJECTIVE: To compare the results and effect of different neuromuscular pedicle (NMP) embedded in posterior cricoarytenoid muscle. METHOD: In 22 dogs, combined vocal cord paralysis models were made. The first group (10 dogs) were embedded by sternohyoid muscle pedicle of ansa cervicalis, the second (10 dogs), accessory sternocleidomastoid neuromuscular pedicle, the third (2 dogs), control group. RESULT: Evaluation was possible in 19 dogs. Reinnervation of the left posterior cricoarytenoid muscle occurred in 17 dogs following NMP. Return of spontaneous abduction in the operated side with NMP was noted after 4 months postoperatively. There was little difference between the two NMP groups. CONCLUSION: NMP was successful to reinnervate the posterior cricoarytenoid muscle.

Accessory Nerve↗
PubMed1999

[A treatment to serious esophageal cicatrices stenosi by metal and silica gel dilator].

OBJECTIVE: To find an effective method of treating the esophageal cicatricial stenosis. METHOD: Six cases with esophageal cicatricial stenosis were treated by mental and silica gel dilator. RESULT: The effects in all six cases were satisfactory and no any complications were finded. CONCLUSION: The method is safe, effective and of no complications, the treatment time is shorter also.

Adolescent↗
PubMed1999

[Determination of monensin residue in chicken by HPLC with post-column derivatization].

The monensin residue was extracted from the tissue by homogenization with methanol-water and the extract was filtered and partitioned with dichloromethane. The dichloromethane extract is concentrated and clean up by passing through a silica gel cartridge. The analyte on the cartridge is then eluted with dichloromethane-methanol. The eluate is collected and evaporated to dryness. The residue is dissolved and made to a definite volume with 1 mL methanol and the solution is used for post-column derivatization-HPLC determination. Monensin is separated on mu-Bondapak C18 column (3.9 mm i.d. x 300 mm) with methanol-water-phosphoric acid as a mobile phase and the flow rate was 0.7 mL/min. The eluted monensin was reacted with vaniline under acidic and heated condition in post-column derivatization system then detected at 520 nm and quantitated by external standard method. The derivatization reagent consisted of 20 mL concentrated sulfuric acid, 950 mL methanol and 30 g vaniline. The flow rate was 0.7 mL/min. The reactor was a stainless steel coil (300 cm x 1 mm i.d.) set in a 90 degrees C oven. The response values was linear between 20-200 ng. The recovery was 88.1%-101.3%. The coefficient of variation was 0.1%-0.73%.

Animals↗