Biomedical subjects

L Sun

Publications and source records attributed to L Sun.

At least 163 records · Page 9Linked to original sources

PubMed2000

Effect of intravenous nitroglycerin on hemodynamics in infants and children with congestive heart failure.

OBJECTIVE: To understand the effect of intravenous nitroglycerin (NTG) on hemodynamics in infants and small children with congestive heart failure secondary to congenital cardiac defect of left to right shunt. METHODS: Heart rate, blood pressure and total peripheral resistance were monitored continuously. Echocardiography was used to measure ejection fraction, fractional shortening, end-diastolic volume index of left ventricle, pulmonary capillary wedge pressure, pulmonary artery mean pressure and left ventricular wall stress before the use and during 0.5, 1.0, 1.5, 2.5, and 5.0 micrograms.kg-1.min-1 dosages of nitroglycerin (NTG). RESULTS: There was no significant difference in the indexes of heart rate, blood pressure, ejection fraction and fractional shortening of left ventricle, stroke volume index, cardiac output index, end-diastolic volume index before the use and after the use of NTG. Pulmonary capillary wedge pressure decreased from 15.5 +/- 2.3 mm Hg before the use of NTG to 14.3 +/- 2.2 mm Hg after the use of 0.5 microgram.kg-1.min-1 NTG (P < 0.05), minimum to 12.3 +/- 2.4 mm Hg; left ventricular wall stress I, II and III decreased from 407 +/- 65 dyn.cm-2.10(3), 166 +/- 48 dyn.cm-2.10(3), 255 +/- 52 dyn.cm-2.10(3) to 357 +/- 75 dyn.cm-2.10(3), 136 +/- 48 dyn.cm-2.10(3), 218 +/- 52 dyn.cm-2.10(3) (P < 0.05), minimum to 321 +/- 50 dyn.cm-2.10(3), 114 +/- 42 dyn.cm-2.10(3), 187 +/- 42 dyn.cm-2.10(3), respectively. Total peripheral resistance and pulmonary artery mean pressure were decreased when the dosage of intravenous NTG was increased to above 2.5 micrograms.kg-1.min-1 (P < 0.05). There was no statistical difference in the above indexes of the different dosages. CONCLUSION: Congestive heart failure secondary to congenital cardiac defect of left to right shunt in infants and small children is the indication of using intravenous NTG which could improve hemodynamics. There was different selectivity in dosage between arterial and venous vasodilatation, and the change in hemodynamics was independent of dosage. The dosages of 0.5-1.0 microgram.kg-1.min-1 NTG are recommended when the decrease of cardiac preload is the main point of therapy of heart failure.

Dose-Response Relationship, Drug↗

PubMed2000

Changes in airway responsiveness and relative factors in asthma with remission at puberty.

OBJECTIVE: To elucidate the airway responsiveness and its relative factors in asthma with natural remission at puberty. METHOD: The airway responsiveness was evaluated by provocation of methacholine (PC20). Blood sIL-2R, IL-4 and IFN-gamma values in the cultural supernatant of mononuclear cells, eosinophil count, basophil count and basophil releasability were detected in 18 asthmatic cases with remission at puberty (group I), in 20 asthmatics without remission at puberty (group II), and in 30 healthy controls (group III). RESULT: The mean value of PC20 in group I was significantly lower than that in group III (P < 0.01), but still higher than that in group II (P < 0.01). The blood sIL-2R, and eosinophil counts dropped almost to those of group III, significantly lower than those of group II. IL-4 in the culture supernatant of mononuclear cells was similar to group III, but significantly lower than that in group II. However IFN-gamma was also similar to group III, significantly higher than that of group II. The basophil count and positive rate of human basophil degranulation test stimulated by mannitol with hyper-osmolarity were still abnormal, significantly higher than those of group III, and the basophil level was significantly related to the airway responsiveness. CONCLUSION: The asthmatics with remission at puberty have a certain degree of airway hyper-responsiveness that is related to the abnormality of basophil.

Adolescent↗

PubMed2000

Mutation in the leucine-rich repeat of platelet glycoprotein Ib alpha results in defects in its interaction with immobilized von Willebrand factor under flow.

OBJECTIVE: To characterize effects of the GP Ib alpha mutation (A156V) on its interaction with von Willebrand factor (vWf) under high fluid shear stress. METHODS: The residue A156 of GP Ib alpha was converted to a valine and the mutant expressed in CHO cells expressing wild-type GP Ib beta and GPIX. The transfected cells were tested for their interaction with a panel of GP Ib alpha antibodies and for rolling on immobilized vWf under high shear. RESULTS: The mutation led to surface expression of a GP Ib alpha polypeptide that adopted a different conformation at its N-terminus because binding of the GP Ib alpha antibody AN51, which has a binding epitope in the N-terminal 35 residues, was eliminated, whereas binding of the others (AK2, MB45, and SZ2, all of which bind to regions C-terminal to the AN51 epitope) was normal. Mutant-expressing cells could adhere and roll on immobilized vWf under high fluid shear stress and rolled significantly faster than wild-type cells. CONCLUSION: These studies demonstrate that the mutation A156V results in a conformation change at the N-terminus of GP Ib alpha, which leads to an increase in the dissociation rate of the bond between the GP Ib alpha mutant and vWf.

Animals↗

PubMed2000

[Distribution of interleukin-6 receptors (CD(126) and CD(w130)) on circulating lymphocytes in patients with lupus nephritis].

OBJECTIVE: To study the distribution of IL-6 receptors (CD(126) and CD(w130)) on lymphocytes in patients with lupus nephritis (LN). METHOD: The percentages of lymphocyte subsets were examined by direct two colour immunofluorescence on flow cytometry. RESULTS: (1) In active and inactive cases, the percentages of CD(+)(4) cells obviously decreased as compared with the normal controls (P < 0.01). Increased numbers of CD(+)(8) cells could be detected in LN patients (P < 0.05), especially in active cases (P < 0.01). Lymphocytes of active cases contained significantly greater percentage of CD(+)(23) cells than those of normal subjects (P < 0.05). On the contrary, the percentage of CD(+)(23) cells was statistically lower in the inactive cases than in normal subjects (P < 0.01). No significant difference in the percentages of CD(+)(126) and CD(+)(w130) cells was observed among the active, inactive and healthy groups (P > 0.05); (2) The proportion of CD(+)(4) CD(+)(126) and CD(+)(4) CD(+)(w130) cells in total lymphocytes was significantly lower in the active than in the inactive ones or normal subjects (P < 0.05; P < 0.01), whereas that of CD(+)(8) CD(+)(126) and CD(+)(8) CD(+)(w130) cells was not different among the active, inactive and normal subjects (P > 0.05). The proportion of CD(+)(23) CD(+)(126) cells and CD(+)(23) CD(+)(w130) cells augmented significantly in the active (P < 0.05), whereas it lessened in the inactive without statistical meaning as compared with the normal subjects (P > 0.05). (3) There was a positive correlation between the percentage of CD(+)(23) CD(+)(126) cells and that of CD(+)(23) CD(+)(w130) cells in total lymphocytes in the active group (r = 0.756, P < 0.05). However, no correlation between the percentage of CD(+)(23) CD(+)(126) cells and that of CD(+)(23) CD(+)(w130) cells in total lymphocytes was found in the inactive (r = 0.376, P > 0.05) or normal group (r = 0.256, P > 0.05); (4) The fraction of CD(+)(23) cells expressing CD(126) and CD(w130) was related to the SLE disease activity index (SLEDAI) and lymphopenia (P < 0.05, P < 0.005). But it was neither associated with the number of damaged organs and the degree of damage, not with that of ANA, anti-dsDNA antibody and complements (C(3) and C(4)) (P > 0.05). CONCLUSIONS: LN patients present not only B cell hyperactivity but also T cell abnormality. In active cases, there is abnormal distribution of IL-6 receptors on lymphocytes: reduced CD(126) and CD(w130) expression on CD(+)(4) cells and elevated CD(126) and CD(w130) expression on CD(+)(23) cells. Detecting the proportion of CD(+)(23) CD(+)(126) cells or CD(+)(23) CD(+)(w130) cells in total lymphocytes may serve as one of activity indexes for LN patients.

Adolescent↗

PubMed2000

[Investigation and comparison of the beta3-adrenergic receptor gene Trp64Arg mutation in the Chinese and Japanese].

OBJECTIVE: To compare the clinical features associated with the Trp64Arg mutation of the beta 3-adrenergic receptor (beta 3AR) gene between the Chinese and Japanese, the BMI, blood pressure, heart rate and plasma lipoproteins in the 2 cohorts. were investigated. METHODS: Two groups of Chinese patients including 614 non-diabetes (ND) (group 1) and 137 NIDDM (group 2), and 2 groups of Japanese patients including 746 health check people in Hachijo Island (group A) and 371 outpatients with diabetes or/and hyperlipidemia (group B) were investigated. PCR for the Trp64Arg mutation in the beta 3-adrenergic receptor (beta 3AR) gene was performed in all subjects. RESULTS: (1) The allelic frequency of the Trp64Arg mutation was 19.7% in NIDDM and 17.4% in ND group, mean 17.8% in the Chinese, and 23% in the group A and 18.3% in the group B, mean 21.7% in the Japanese. (2) The frequency of Trp64Arg mutation in the beta 3AR gene was gradually increased with the increase in BMI in the Chinese and the significance was shown in women between BMI < 25 and BMI > 28 (15.9% vs. 29.1%, P < 0.02). The Trp64Arg genotypes of the beta 3AR had a significantly higher BMI compared with Trp64Trp genotype in the Chinese (P < 0.001 and 0.002, respectively). But no significant differences were found in the Japanese. (3) A significant lower total cholesterol in Arg64Arg than in Trp64Trp was seen in Japanese men (P = 0.03), and in both Arg64Arg and Trp64Arg in Chinese men (P < 0.001 and P < 0.005). (4) Slightly higher systolic blood pressure was observed in Arg64Arg than in Trp64Trp in Japanese men (P = 0.0 026), and significantly higher heart rate in Arg64Arg than Trp64Arg and Trp64Trp in Chinese (P < 0.001). (5) HDL-C was significantly lower in Arg64Arg than in Trp64Trp in the Chinese, (P < 0.001). CONCLUSION: The Trp64Arg Department of Metabolic Diseases, Faculty of Medicine, University of Tokyo (Yoko Iizuka, Shun Ishibashi, Takanari Gotoda), Institute of Clinical Medicine University of Tsukuba, Tsukuba, Japan (Nobuhiro Yamada) mutation in beta 3-adrenergic receptor gene contributes to the increased body weight in the Chinese, especially in older women, but not in the Japanese, and to the lower plasma total cholesterol levels in both Chinese and Japanese men, and it potentially contributes to higher systolic blood pressure, faster heart rate and lower HDL-c as well.

Adult↗

PubMed2000

[The expression of multiple drug resistance associated genes in ovarian cancer].

OBJECTIVE: The aim of the investigation was to find out the relationship between the expression of multidrug resistance gene (MDR1), multidrug resistance protein (MRP), lung resistance protein (LRP) and glutathione S-transferase pi (GST-pi) with the clinical pathological characteristics and the prognosis in the ovarian cancer patients who never received chemotherapy before operation. METHODS: The expression of MDR1, MRP, LRP and GST-pi in 41 cases of ovarian cancer, 25 cases of benign ovarian tumor and 12 normal ovary tissue were investigated by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: In normal ovary, benign tumor and ovarian cancer, the positive expression of MDR1 was 0.0%, 0.0% and 29.3%, the positive of MRP was 16.7%, 12.0% and 53.7%, the positive of LRP was 25.0%, 52.0% and 87.8%, the positive of GST-pi was 8.3%, 12.0% and 51.2% respectively. The ratios of co-expression of multiple genes in ovarian cancer were much higher than that in benign ovarian tumor. All tested genes showed no significant relationship to the clinical stage, histological type and the differentiation of the tumor except that the expression of MDR1 and MRP was closely related to the differentiation (P < 0.05). The non-responders to platinum or taxol based combination chemotherapy exhibited higher ratios of MDR1 and MRP expression than the responders (P < 0.05). Furthermore, the co-expression phenomenon was more common in non-responders. CONCLUSIONS: Multiple gene expression is involved in drug resistance in ovarian cancer. The co-expression of MDR1, MRP, LRP and GST-pi is higher in ovarian cancer than that in benign ovarian tumor and normal ovary tissue. The expression of MDR1 and MRP is closely related to the tumor differentiation and the response to chemotherapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2000

[Fresh femoral shaft fractures treated with un-reamed intramedullary nail: 203 cases].

OBJECTIVE: To discuss the experience treating fresh femoral shaft fractures with un-reamed intramedullary nail. METHODS: 203 cases of fresh femoral shaft fractures who had been treated with un-reamed intramedullary nail from November. 1995 to January. 1999 were analyzed retrospectively. 18 cases were open, classified as Gustilo I, and. 185 cases were closed. Traction table and image intensifier were used during operation. Closed reduction, un-reamed and free hand distal locking technique were used. Active movements of nearby joints were encouraged and partial weight bearing of 10 - 15 kg were allowed right after operation. RESULTS: All 203 cases of fresh femoral shaft fractures got bone union within 4 - 6 months. No case of delayed union and infection happened. 1 distal locking screw was broken. All patients gained normal extremity functions. CONCLUSION: Un-reamed intramedullary nailing of fresh femoral shaft fracture has less damage to the local soft tissue and blood supply. It has a relative stable fracture fixation, and less interruption to the healing procedure. It is one of the best methods for treating femoral fracture.

Bone Nails↗

PubMed2000

[Geographic information systems spatial analysis on transmission of schistosomiasis in China].

OBJECTIVE: To understand the epidemiologic status and geographical distribution of schistosomiasis in China. METHODS: Relevant detabases were set up after collection of data from two National Sampling Surveys on Schistosomiasis, in 1989 and 1995. Spatial analysis was undertaken after the database linked to the GIS software which was supported by Arc View 3.0a. Correlation analysis was performed to understand the relationship between rates of human infection and cattle infection. RESULTS: The epidemic areas of schistosomiasis with high risk are mainly distributed in the marshland along the Yangtze River and can be identified as five spatial distribution regions based on the results of spatial analysis. Both epidemic areas and positive rates of stool examination in cattle and water buffalo are much wider and higher than that in humans. The positive correlation was seen between infection rate in human and in cattle from data of both sampling surveys. CONCLUSION: The relevant strategy for schistosomiasis control in different spatial regions should be performed accordingly and the measures of control for cattle and water buffalo should be strengthened in the endemic areas.

Adolescent↗

PubMed2000

[Dynamic analysis of junctional sequences of T cell receptor (TCR) delta and gamma gene rearrangement in childhood with acute lymphoblastic leukemia].

OBJECTIVE: To explore the junctional sequence difference of T cell receptor delta and gamma gene rearrangement in childhood acute lymphoblastic leukemia (ALL) at diagnosis, complete remission (CR) and relapse. METHODS: By using the T-vector molecular cloning and sequencing and polymerase chain reaction, the junctional sequences of TCRdeltaV-D and TCRgammaV-J were dynamically analyzed in 34 bone marrow samples of ALL. RESULTS: The junctional sequence of TCR delta, gamma gene showed significant difference and regularity before and after remission and during relapsed periods. The sequence of TCRdeltaV-D were analyzed in 24 samples from ALL. Among them, the intact Vdelta2 and 5'Ddelta3 sequences were observed in 10 samples at diagnosis, of which 7 samples had T-->C mutation in Ddelta3 nonamer sequence. The deletions of rearranged Vdelta2, 5'Ddelta3 and Ddelta3 haptamer sequences were found in 11 complete remission (CR) samples with ALL, but none had T-->C mutation in Ddelta3 nonamer sequence. The deletion rate of Vdelta2 or Ddelta3 sequences and the T-->C mutation in Ddelta3 nonamer sequence were extremely differed between samples at diagnosis and in remission (calculate exact probabilities P = 0.001). The junctional rearrangement sequence of 5'Ddelta3 sequences tended to remain intact in 3 relapsed samples. The findings of TCRgammaV-J sequences were similar to that of TCRdeltaV-D in 10 ALL patients. CONCLUSION: The difference of TCRdeltaV-D and TCRgammaV-J junctional sequences were related to the development, therapeutic effectiveness and outcome in ALL.

Child↗

PubMed2000

[A mutation of platelet glycoprotein I balpha results in defects in its interaction with immobilized vWF].

OBJECTIVE: To study the importance of glycoprotein (GP) I balpha mutation (A156V) in interaction between mutant expressing cell and immobilized vWF under fluid shear stress. METHODS: Mutant GP I balpha cDNA was cloned into the EcoR I site of the mammalian expression vector pDX, mutant cDNA was then transfected into CHO betaIX cells. Human vWF was purified from blood cryoprecipitate by glycine and NaCl precipitation and subsequent separation on sepharose 4B column. The purified vWF was immobilized onto a coverslip. Cell rolling was induced in a parallel-plate flow chamber and observed by phase-contrast video microscope. RESULTS: CHO cells expressing GP I b-IX-V complex could adhere to and roll on immobilized vWF. The A156V mutant cells retained the ability to adhere and roll on vWF matrix, but the rolling speed was significantly faster than that of wild type cells, indicating that the off-rate of the ligand-receptor bond between the mutant and vWF was impaired. Binding of monoclonal antibody AN51 to mutant GP I balpha decreased significantly, indicating that the A156V mutation altered the conformation of the N-terminal ligand-binding region of GP I balpha. CONCLUSION: The mutant GP I balpha has a faster off-rate for its interaction with immobilized vWF. The mutant polypeptide adopts an altered conformation in N-terminal ligand-binding region of GP I balpha. The parallel-plate flow chamber is an extremely useful system in evaluating interaction between GP I balpha and vWF.

Animals↗

PubMed2000

[The sensitivity to apoptosis is enhanced in U937-ASPI-3K cells which stably express antisense ATM/PI-3K].

OBJECTIVE: To analyse the characteristics of apoptosis sensitivity in U937-ASPI-3K cells which is stably expressing anti-sense ATM/PI-3K. METHOD: Annexin V-PI apoptosis detection kid and flow cytometry were used to determine apoptosis rate, Western blot to the expression level of cytochrome C protein and Bcl-2 protein. RESULTS: U937-ASPI-3K cells had a lowered threshold for triggering apoptosis in response to low dose irradiation. Cell apoptosis rate was 28% and (53.0 +/- 5.4)%, respectively, at 8 and 48 hours after 1.5 Gy (137)Cs irradiation, while in U937-pZEOSV2 (+) control group it was 4.2% and (11.0 +/- 3.3)%, respectively. Cytosolic cytochrome C protein band was gradually intensified in U937-ASPI-3K in 4 - 8 h after irradiation, but was not detected in control group. Bcl-2 protein gradually decreased in U937-ASPI-3K in 4 - 8 h after irradiation, but didn't change obviously in control group. CONCLUSION: Cell line U937-ASPI-3K acquired a phenotype with a lowered threshold for triggering apoptosis. It demonstrated that selective inactivation of ATM gene might be of considerable value in tumor treatment.

Apoptosis↗

PubMed2000

[Change of pulmonary circulation in microgravity and simulated microgravity].

Fluid is transferred cephalad in microgravity and simulated microgravity, and the pulmonary circulation is the first to be affected. Blood and fluid contents in the lungs increase, but unevenly distributed among various zones of the lungs. Blood vessels in the lungs are filled and distend. Capillary changes have been observed in the animal model of simulated microgravity. Studies about the changes of regulative function of pulmonary circulation are relatively rare. Observations of the reactivity of pulmonary vessels may help to understand the mechanisms of the changes in pulmonary circulation during microgravity.

Animals↗

PubMed2000

[Osteoarticular allografts for repairing large bone or osteoarticular defects].

OBJECTIVE: To evaluate clinical outcome of bone or osteoarticular allografts. METHODS: From September 1991 to November 1997, large bone or osteoarticular defects secondary to bone tumors resection in 36 patients and severe trauma in 2 patients were repaired by deep frozen or lyophilized allogeneic osteoarticular or diaphysis graft. RESULTS: No obvious immune rejection to the grafts was observed in most of the patients in early stage after operation. The patients were followed up from 1 year and five months to 7 years and five months with an average of 4.2 years. Limb function was satisfactory in 74.19% of the 31 survival patients with large osteoarticular or diaphysis allografts. CONCLUSION: Cryopreserved or lyophilized allogeneic osteoarticular grafts with decreased antigenicity and good biocompatibility are suitable materials for repairing large bone or osteoarticular defects.

Adolescent↗

PubMed2000

[Quality evaluation of indigowoad root and leaf by chemical pattern recognition].

27 samples of indigowoad root and 5 samples of indigowoad leaf from different species and in different habital were collected. The chemical constituents were analyzed by HPLC, and ten original chemical features as a whole obtained. Meanwhile, extrinsic bacteriostasis experiments were carried out for each of the 32 samples. Canonical correlation analysis was applied to the intercorrelation between the chemical and the pharmacologic data, and five chemical features were found to be the effective constituents. In the end, the 32 samples were divided into five classes by the fuzzy clustering technique ISODATA(interachive self-organizing data analysis technique A).

Brassicaceae↗

PubMed2000

[Effect of qiongyugao on the action of DDP in inhibiting the division of GLC-82 cell strain in vitro].

OBJECTIVE: To observe the effect of Qiongyugao (QYG) on the action of DDP in inhibiting the division of GLC-82 cell strain in vitro. METHODS: The method of serum pharmacology was used in observing the morphological change of the cancer cells. By accounting the number of the live cells of each day during 6 days respectively, the growth curve was drawn up. The effects of the three groups on the cancer cells apoptosis of GLC-82 cell strain were analysed by FACS. RESULLTS: The growth of the cancer cells in control group (normal saline) was much better than the other two groups; in chemical therapy group (DDP), the number of the live cells almost kept steady; the number of the live cells in combined group(DDP plus QYG) became even lower. QYG could enhance the action of DDP in inducing the apoptosis of GLC-82 cells strain remarkably. CONCLUSION: QYG can enhance the effects of chemotherapy in inhibiting cancer cells division and inducing their apoptosis.

Adenocarcinoma↗

PubMed2000

[Histological study of the local-regional invasion of pyriform sinus carcinoma].

OBJECTIVE: In order to offer the basis for the operation of the pyriform sinus carcinoma, the local-regional invasion patterns of the pyriform sinus carcinoma were investigated. METHODS: Twenty-six surgical specimens obtained from patients who undergone laryngopharyngectomy were subjected to a whole organ section study. RESULTS: Tumors located in the lateral wall of the pyriform sinus spread mainly towards the lateral wall of the hypopharynx. Tumors located in the inner wall of the pyriform sinus spread mainly towards the larynx and opposite side pyriform sinus, the paraglottic space and thyroid cartilage were particularly frequent invaded. It was rare of the invading of the cricoid cartilage. The invasion of the epiglottis and preepiglottic space across the midline had not been found. There were two invading routines, the paraglottic space and preepiglottic space. The invasion of the paraglottic space was through the aryepiglottic fold and the inner surface of the thyroid cartilage. The invading of the preepiglottic space was through the aryepiglottic fold and the upper part of the inner surface of the thyroid cartilage. CONCLUSIONS: The invading of the preepiglottic space was not the contraindication of the partial laryngectomy. It is practicable to preserve the laryngeal function in most of the patients while tumors located on the lateral or inner wall of the pyriform sinus. There was a tendency to the invading to the contralateral side in the inner wall of the pyriform or postcricoidarytenoid region. Attention should be paid to the submucosal spreading in the postcricoidarytenoid region.

Adult↗

PubMed2000

Effects of XW630 on bone formation in ovariectomized rats and in human osteoblast-like cells.

OBJECTIVE: To study the effects of XW630 on bone formation in overiectomized (OVX) rats and in human osteoblast-like cell line TE85. METHOD: Bone histomorphometric analysis was performed with undecalcified bone sections and tetracycline intraperitoneally labeling. RESULTS: Compared with that of OVX rats, the static data of trabecular bone volume (TBV)/total tissue volume (TTV), TBV/sponge bone volume (SBV) and mean trabecular plate density (MTPD) were enhanced while mean trabecular plate spacing (MTPS) decreased after treated with XW630 for 13w. The dynamic data of single-labeled surface [Sfract(s)], double-labeled surface [Sfract(d)], Sfract(d+1/2s), trabecular osteoid surface (TOS) and bone formation rate in tissue level (Svf) were increased and osteoid maturation period (OMP) shortened in XW630 group. In osteoblast-like cells, both 3H-thymidine incorporation and cell count increased after treated with XW630 for 48. Treated with XW630 for 12 approximately 18h, inducible nitric oxide synthase (iNOS) activity and cGMP content increased in time-dependent manners. CONCLUSIONS: XW630 enhanced bone activation frequency and increased trabecular connectivity, stability, and strength. The cellular mechanism related to effects of XW630 on bone formation in ovariectomized rats.

Animals↗

PubMed2000

[Effects of high dose of dynorphin on NMDA receptor and NOS activities in spinal cord of rats].

OBJECTIVE: To elucidate the effects of N-methyl-D-aspartate(NMDA) receptor and nitric oxide synthase (NOS) activity in dynorphin (Dyn)-induced spinal cord injury. METHODS: The NMDA receptor activity was measured by radio-ligand of 3H-MK801. The constitutive and inducible NOS (cNOS and iNOS) activities were assayed by 3H-arginine conversion. RESULTS: In ventral samples, both 3H-MK801 binding and cNOS activity increased at 0.5 h and persisted for 48 h while iNOS activity enhanced at 4 h after intratheacal injection (i.t.) Dyn A(1-17) at dose of 20 nmol/L. However, the 3H-MK801 binding activity reduced significantly from 4 h to 24 h and cNOS activity did not change at the same time in dorsal samples. 7-nitroindozol (7-NI) and aminoguanidine (AG) inhibited the effects of Dyn A(1-17) (20 nmol/L) on 3H-MK801 binding and NOS activities in ventral samples. N-nitro-L-arginine methyl ester (L-NAME) did not affect the elevation of Dyn A(1-17) on NOS activities but caused 3H-MK801 binding activity reduction in ventral samples. CONCLUSIONS: NMDA-NOS pathway might play important role in Dyn spinal neurotoxicity. NOS inhibitors and Dyn might produce cooperative down-regulation on the function of NMDA-NOS pathway in dorsal cord.

Animals↗