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Biomedical subjects

X Luo

Publications and source records attributed to X Luo.

At least 55 records · Page 3Linked to original sources

[Effect of two extracted fraction from Lycopus lucidus on coagulation function].

OBJECTIVE: To find and define the effective fraction of Lycopus lucidus on coagulation. METHODS: Method of comparing turbidity, method of cutting a part of the mice tail and method of breaking glass tube. RESULTS: The two extracted fraction from lycopus lucidus F04-0A and F04-B could inhibit rats platlet aggregation in vitro and mice platelet aggregation in vivo. They could also prolong mice blood coagulation time. However, they had no effect on bleeding time. CONCLUSION: Both F04-A and F04-B had effects on inhibiting platelet aggregation and blood coagulation. Moreover, the activity of F04-A was probably stronger than that of F04-B. F04-A may be the effective fraction from Lycopus lucidus on promoting blood circulation and removing blood stasis.

Animals↗

[Determination of sarsasapogenin in "tian dong" by TLCS].

This paper reported the determination of sarsasapogenin in 12 samples from 7 species and varieties of Asparagus genus whose commercial name is "Tian-Dong"(Radix Asparagi), Asparagus cochichinensis(Lour.) Merr, A. cochichinensis (lour.) Merr. var. gaudichaudianus (Kunth) X. D. Luo and G. J. Xu, A. taliensis Wang et Tang, A. munitus Wang et Tang, A. myriacanthus Wang et S. C. Chen, A. meioclados Levl and A. trichoclados (Wang et Tang) Wang et S. C. Chen by TLCS. The results showed that it was no pertinence between content of sarsaspogenin with the species, and the content of sarsasapogenin in the tuberous roots was inverse ratio with the commercial grande in same species.

Aspalathus↗

[Relationship between soil water content and water use efficiency of apple leaves].

The relationship between soil water content and water use efficiency (WUE) of apple tree leaf was examined, and the mechanism of WUE variation was also studied by using pot-culture. The results showed that the WUE was upmost when soil water relative content (SWC) reached 52.0%. The increase of WUE when SWC decreased from 77.2% to 52.0% was mainly caused by the change of stomatal conductance. The decline of carboxylation efficiency resulted in the decrease of WUE when SWC decreased from 52.0% to 20.1%. The WUE returned up after being rewatered, but could not reach the control level within a week. The WUE decreased when the soil was waterlogged, but reached the control level in three days after being waterlogged. After the third day, the WUE decreased gradually with the extending of the time being waterlogged. On the sixth day being waterlogged, the carboxylation efficiency decreased.

Malus↗

[Expression of glutathione S-transferase-pi in human esophageal squamous cell carcinoma].

OBJECTIVE: To evaluate the expression of glutathione S-transferase-pi (GST-pi) in human esophageal squamous cell carcinoma (ESCC) and its correlation with the clinicopathological data. METHODS: Immunohistochemical method (labeled avidin biotin method) and ELISA were used to detect the expression of glutathione S-transferase-pi (GST-pi) in 143 cases of formalin fixed, paraffin embedded ESCC tissue sections. Serum GST-pi was determined before and after operation in 43 patients with ESCC. RESULTS: GST-pi was positively stained immunohistochemically in 58.7%(84/143) of ESCC and 79.6%(109/139) of surrounding noncancerous esophageal tissues (P < 0.05). The expression level of GST-pi was significantly higher in well differentiated than poorly differentiated carcinomas(P < 0.05). No significant correlation was observed between GST-pi levels and lymph node metastasis, pathological staging or long term survival. The preoperative and postoperative mean serum GST-pi levels in ESCC patients were significantly higher than those in 34 normal subjects (P < 0.05, P < 0.025); the mean serum GST-pi level in postoperative patients was lower than that in preoperative patients, but the difference was not significant. CONCLUSION: GST-pi is a useful tumor marker for human ESCC.

Adult↗

[Research on the matching between alumina-glass composite and Vita alpha veneering ceramic].

OBJECTIVE: To investigate the matching between self-made alumina-glass composite and Vita alpha veneering ceramic. METHODS: By using thermal shock test and SEM. RESULTS: The crazing resistance of alumina glass composite via Vita alpha ceramic expressed as the mean delta T was 170 degrees C. SEM micrograph indicate that Vita alpha ceramic fused to alumina glass composite, and no crack between the combination interface. CONCLUSION: Alumina-glass composite can match to the Vita alpha ceramic fairly.

Aluminum Oxide↗

[The influence of the change in postburn erythrocyte membrane viscoelasticity on the regional myocardial blood flow].

OBJECTIVE: To explore the characteristics of the dynamic change in postburn erythrocyte membrane viscoelasticity and its influence on the regional myocardial blood flow. METHODS: Wistar rats inflicted with 30% TBSA III degree scalding on the back were employed as the model. The mechanical indices of erythrocytic membrane, such as elastic modulus and the coefficient of viscosity, were determined with micro-pipe sucking methods at preburn and 1, 3, 6, 12, 24 and 48 postburn hours (PBHs). The regional myocardial blood flow was simultaneously monitored with hydrogen clearance methods. RESULTS: The erythrocyte membrane viscoelasticity increased sharply at 3 PBH, reached the peak level at 6 PBH and decreased gradually thereafter to near normal level at 24 PBH. The regional myocardial blood flow decreased obviously at 1 PBH, it reached the lowest level at 6 PBH and bounced back to near normal level at 48 PBHs. The change in the viscoelasticity was significantly and negatively correlated to that of the regional myocardial blood flow. CONCLUSION: The deformability of postburn erythrocyte membrane decreased, leading to the decrease in the regional myocardial blood flow. This might be one of the important reasons of postburn myocardial injury.

Animals↗

[Clinical and MRI diagnosis of nasopharyngeal carcinoma with orbital spread].

OBJECTIVE: To study the routes, clinical manifestations and MRI characteristics of nasopharyngeal carcinoma (NPC) with orbital spread. METHODS: Twenty (23 eyes) such cases were selected, including 6 (7 eyes) preradiotherapy cases and 14 (16 eyes) postradiotherapy cases. The magnetic resonance imaging (MRI) axial, coronal, sagittal routine procedures and gadolinium-diethylene triamine pentaacetic acid (GD-DTPA) contrast-enhanced scan were performed. Fatty-restraint scan was performed after enhancement only on 3 cases. The diagnosis in all the patients was proved by the biopsy from the nasopharynx. RESULTS: (1) Single orbit involvement was seen in 17 patients, 12 in the left and 5 in the right orbit. Bilateral orbit involvement was only found in 3 patients. (2) Major clinical manifestations of orbital involvement by NPC included: 13 cases (15 eyes) suffered from decrease of visual acuity, 9 cases (10 eyes) with exophthalmos, 11 patients (12 eyes) with ocular movement disorder, 7 cases (9 eyes) with diplopia and 5 cases (7 eyes) with blepharoptosis. (3) MRI appearances: There were 13 cases (15 eyes) with optic nerve involvement, 9 patients (11 eyes) with abnormalities in extraocular muscle, 8 cases (9 eyes) with retrobulbar tumor and 15 cases (17eyes) with orbital apex and orbital lamina bony involvement. (4) The three main routes for orbital involvement in NPC patients were as follows: (a) through cavernous sinus (the skull base) to superior orbital fissure. (b) through paranasal sinus (particularly the ethmoid sinus). (c) through pterygopalatine fossa to inferior orbital fissure. CONCLUSION: MR imaging is very useful to demonstrate the presence, location and extent of orbital involvement in NPC patients.

Adult↗

[The combination of cyclosporin A and androgen in the treatment of chronic aplastic anemia].

OBJECTIVE: To explore the therapeutic effectiveness of combination of cyclosporin A (CsA) and androgen in the treatment of chronic aplastic anemia (CAA). METHOD: Androgen alone or combined with CsA for the treatment of CAA was compared by a randomized controlled clinical trial. RESULT: The efficacy of androgen combined with CsA (87.9%) was higher than that of androgen alone (57.1%). Therapeutic effectiveness of the combination treatment between the patients with positive and negative peripheral blood mononuclear cells (PBMNCs) inhibiting normal colony formation unit-granulocyte and macrophage (CFU-GM) test showed a significant difference (P < 0.005). CONCLUSION: Androgen combined with CsA had a much better efficacy than that of androgen alone in the treatment of CAA. The patients' PBMNCs inhibiting normal CFU-GM growth test can be used as an index of the treatment outcome. The side effects of the combination therapy are low and tolerable.

Adolescent↗

Studies on the development of DNA vaccine against Cysticercus cellulosae infection and its efficacy.

DNA vaccine against Cysticercus cellulosae infection was developed and its efficacy was tested. A pair of primers specific to antigen B gene of C. cellulosae was designed which amplified the gene successfully with RT-PCR. The gene was ligated to PV93 vector, and the recombinant of antigen B gene and PV93 was transformed to JM83 cells. The transformed JM83 cells were cultured in a large scale and the plasmid purified. Based on the recombinant plasmid. a DNA vaccine was developed and used to vaccinate two groups of experimental pigs. In each group, there was a routine vaccine, an enhanced vaccine and a control group. Groups 1 and 2 were challenged at 4 months and at 14 days post vaccination respectively with eggs of Taenia solium. The antibody response was also tested with ELISA. The results suggested that all animals vaccinated AgB gene DNA vaccine, no matter by routine or enhanced vaccine, their antibodies reached maximum peak 23 days post vaccination and decreased gradually. When the animals were challenged 4 months after vaccination, they had strong immunity and the parasites decrease rates were 91.2% and 93.1% respectively. When pigs vaccinated with AgB gene DNA vaccine were challenged 14 days post vaccination with 18,000 eggs/pig. The animals showed strong immunity and the parasite decrease rates were 99.5% and 84.9% respectively. However at that time, the antibodies did not reach the peak. While in the control group, the number of C. cellulosae was as many as 2,500. It was concluded that the pigs vaccinated with DNA vaccine had strong immunity against infection of eggs of T. solium.

Animals↗

[Research on the high strength all ceramic crown by the combination of CAD/CAM and glass infiltrated alumina blocks].

OBJECTIVE: To search for a method that fabricates the high strength all ceramic crown by the combination of CAD/CAM and glass-infiltrated alumina. METHODS: Alumina coping was milled by the Cerec II CAD/CAM and glass was infiltrated into alumina by the capillary effect. Vita alpha ceramic was used to veneer the surface of substructure for all ceramic crown. RESULTS: This technology need not duplicate die and sinter alumina substructure for 10 h, compared with the conventional In-ceram technology. The time of glass infiltration has been decreased from 4 h to 40 minutes by the high capillary effects of prefabricated alumina blocks. CONCLUSION: This is a new method for all ceramic crown by using Cerec II CAD/CAM to mill a simple ceramic block so as to fabricate prosthetics in clinic.

Aluminum Oxide↗

[The millipore rapid screening of hydantoinase production strains].

OBJECTIVE: To find a strain with a higher hydantoinase activity. METHODS: The millipore rapid screening method was established to select the strains. The effects of several solvents on the rate of biotransformation were compared. RESULTS: A hydantoinase production strain has been selected by the millipore rapid screening method. Tween-80 (1%) is found to be a suitable solvent to dissolve the substrate. CONCLUSION: A new method is provided for rapid selection of hydantoinase production strains from large-scale samples. The difficulty in dissolving the substrate has been resolved to some extent.

Amidohydrolases↗

[Studies on the isolation, culture and DNA identification of mycelia of Tricholoma matsutake].

The tissue isolation for Tricholom matsutake(S Ito et Imai) Sing were made with 8 media in 810 test tubes from different positions of 9 basidiocarps of different source and from mycorrhizae, and soil with the fungi in the studies. The results showed that 94 test tubes of slow-growing mycelia were isolated from lamellae and their success percentages of isolation with media PDAS, PDAW, BM, PDA were 74.4%, 355%, 15.6% and 8.9% respectively. The fast-growing mycelia were easily got from the mycorrhizae and soil related to matsutake. The isolates with different culture characteristics were appraised through DNA fingerprinting comparison with matsutake basidiocarps collected from Jilin province, China and reference isolates presented by matsutake research workers of China and Japan, in which RAPD (Random Amplified Polymorphic DNA)-PCR patterns were sharply prepared using 17 arbitrary decamer nucleotide primers screened. The statistical data indicated that all slow-growing mycelia isolated from lamellae had the same DNA fingerprinting patterns as their origin basidiocarps tissues such as pileus (containing lamellae) and stipe, whose similarity coeffecients all were 1.000, and were therefore identified as true Tricholoma matsutake. However, the fast-growing mycelia or yeast colony were identified as not matsutake. The results suggested that matsutake and its own mycelia have DNA homogeneity, and there exists no any other microbe in the basidiocarps. The results also demonstrated that all matsutake from east China and reference isolates of matsutake from southwest China and Japan were one same species Tricholoma matsutake, whose DNA similarity coeffecients varied from 0.934 to 0.994.

Agaricales↗

[Local recurrence of nasopharyngeal carcinoma with normal mucous membrane after radiation therapy: MR imaging findings].

OBJECTIVE: The purpose of this work was to investigate and analyze the MR imaging features of postradiation local recurrence of nasopharyngeal carcinoma (NPC) with normal mucous membrane. METHODS: 24 such cases were studied. The diagnosis of NPC recurrence was pathologically confirmed in 15 patients, and was corroborated by repeated radiation therapy and serial follow-ups in 9 patients. MR imaging routine procedures and Gd-DTPA enhancement were performed for all patients. RESULTS: The MR imaging findings were as follows: 1. The recurrent tumor mass was located in the prestyloid space in 8 patients, with skull base erosion and intracranial infiltration in 7 patients; 2. Retrostyloid space recurrence in 2 patients; 3. Direct bony erosion of the skull base in 7 patients; 4. Recurrence in nasal cavity and ethmoid sinuses in 3 patients; 5. Submucous cystic recurrence in 2 patients; 6. Mixed patterns of recurrence in 2 patients. Except 2 cases of cystic tumor recurrence, all cases exhibited slight hypo- or iso-intensity on T1-weighted images, slight hyper-intensity on T2-weighted images, and moderate to marked enhancement after Gd-DTPA administration. CONCLUSION: There are several special patterns of local NPC tumor recurrence after radiation therapy in the presence of normal nasopharyngeal mucosa. MR imaging is the method of choice to depict the location and extent of NPC tumor recurrence.

Adult↗

The actin-driven movement and formation of acetylcholine receptor clusters.

A new method was devised to visualize actin polymerization induced by postsynaptic differentiation signals in cultured muscle cells. This entails masking myofibrillar filamentous (F)-actin with jasplakinolide, a cell-permeant F-actin-binding toxin, before synaptogenic stimulation, and then probing new actin assembly with fluorescent phalloidin. With this procedure, actin polymerization associated with newly induced acetylcholine receptor (AChR) clustering by heparin-binding growth-associated molecule-coated beads and by agrin was observed. The beads induced local F-actin assembly that colocalized with AChR clusters at bead-muscle contacts, whereas both the actin cytoskeleton and AChR clusters induced by bath agrin application were diffuse. By expressing a green fluorescent protein-coupled version of cortactin, a protein that binds to active F-actin, the dynamic nature of the actin cytoskeleton associated with new AChR clusters was revealed. In fact, the motive force generated by actin polymerization propelled the entire bead-induced AChR cluster with its attached bead to move in the plane of the membrane. In addition, actin polymerization is also necessary for the formation of both bead and agrin-induced AChR clusters as well as phosphotyrosine accumulation, as shown by their blockage by latrunculin A, a toxin that sequesters globular (G)-actin and prevents F-actin assembly. These results show that actin polymerization induced by synaptogenic signals is necessary for the movement and formation of AChR clusters and implicate a role of F-actin as a postsynaptic scaffold for the assembly of structural and signaling molecules in neuromuscular junction formation.

Actins↗

Dynamic interaction of human vasopressin/oxytocin receptor subtypes with G protein-coupled receptor kinases and protein kinase C after agonist stimulation.

Examination of the structure of [Arg(8)]-vasopressin receptors (AVPRs) and oxytocin receptors (OTRs) suggests that G protein-coupled receptor kinases (GRKs) and protein kinase C (PKC) are involved in their signal transduction. To explore the physical association of AVPRs and OTRs with GRKs and PKC, wild types and mutated forms of these receptor subtypes were stably expressed as green fluorescent protein fusion proteins and analyzed by fluorescence, immunoprecipitation, and immunoblotting. Addition of a C-terminal GFP tag did not interfere with ligand binding, internalization, and signal transduction. After agonist stimulation, PKC dissociated from the V(1)R, did not associate with the V(2)R, but associated with the V(3)R and the OTR. After AVP stimulation, only GRK5 briefly associated with AVPRs following a time course that varied with the receptor subtype. No GRK associated with the OTR. Exchanging the V(1)R and V(2)R C termini altered the time course of PKC and GRK5 association. Deletion of the V(1)R C terminus resulted in no PKC association and a ligand-independent sustained association of GRK5 with the receptor. Deletion of the GRK motif prevented association and reduced receptor phosphorylation. Thus, agonist stimulation of AVP/OT receptors leads to receptor subtype-specific interactions with GRK and PKC through specific motifs present in the C termini of the receptors.

Amino Acid Sequence↗

NIMA-related kinase 2 (Nek2), a cell-cycle-regulated protein kinase localized to centrosomes, is complexed to protein phosphatase 1.

The cell cycle-regulated protein serine/threonine NIMA-related kinase 2 (Nek2), which shows a predominant localization at centrosomes, is identified as a protein which interacts with protein phosphatase 1 (PP1) using the yeast two-hybrid system. Complex formation between Nek2 and PP1 is supported by co-precipitation of the two proteins using transfected expression constructs of Nek2 and the endogenous Nek2/PP1 proteins. The sequence KVHF in the C-terminal region of Nek2, which conforms to the consensus PP1-binding motif, is shown to be essential for the interaction of Nek2 with PP1. Nek2 activity increases with autophosphorylation and addition of phosphatase inhibitors and decreases in the presence of PP1. PP1 is a substrate for Nek2 and phosphorylation of PP1gamma(1) on two C-terminal sites reduces its phosphatase activity. The presence of a ternary complex containing centrosomal Nek2-associated protein (C-Nap1), Nek2 and PP1 has also been demonstrated, and C-Nap1 is shown to be a substrate for both Nek2 and PP1 in vitro and in cell extracts. The implications of kinase-phosphatase complex formation involving Nek2 and PP1 are discussed in terms of the coordination of centrosome separation with cell cycle progression.

Amino Acid Motifs↗

Biodistribution and genetic stability of the novel antitumor agent VNP20009, a genetically modified strain of Salmonella typhimurium.

VNP20009 is a genetically modified strain of Salmonella typhimurium possessing an excellent safety profile, including genetically stable attenuated virulence (a deletion in the purI gene), reduction of septic shock potential (a deletion in the msbB gene), and antibiotic susceptibility. VNP20009 is genetically stable after multiple generations in vitro and in vivo. In mice, VNP20009 is rapidly cleared from the blood from a peak level of 1x104 cfu/mL to undetectable levels in 24 h. In tumor-bearing mice, VNP20009 accumulates preferentially in tumors over livers at a ratio of 1000&rcolon;1. In nonhuman primates, VNP20009 was also rapidly cleared from the blood, from a peak level of 1.0x106 cfu/mL to undetectable levels in 24 h. VNP20009 was detected in the liver, spleen, and bone marrow of monkeys; the amount decreased over time, and VNP20009 was cleared from all organs by day 41; no VNP20009 could be detected in the urine or feces of the monkeys. VNP20009 is genetically stable after many generations of growth (>140) both in vitro and in vivo.

Animals↗