Search PubMed⌕ Search

Biomedical subjects

X Yu

Publications and source records attributed to X Yu.

At least 91 records · Page 5Linked to original sources
PubMed2001

[Quantitative analysis of cell fusion caused by glycoprotein of paramyxoviruses with reporter gene method].

OBJECTIVE: To establish a kind of quantitative assay method for analyzing the reporter gene assay for fusion was established. METHODS: Two populations of BHK21 cells were infected with vTF-7 recombinant and wild-type vaccinia viruses respectively and transfected with paramyxovirus F and HN cDNA and plasmid pG1NT7 beta-gal respectively. After 16 h, the two cell populations were removed from the wells by trypsinization. Equal numbers of the two populations were mixed in wells of a 96-well flat-bottom plate after washing and pelleting. After 15 hours' incubation at 37 degrees C, the cells were lysed with Nonidet P-40 and A values were read at 570 nm with an ELISA reader supported by SOFTMAX software. RESULTS: Reporter gene method had a close relationship with cell count method, r = 0.9890(P < 0.01). Positive and negative coincidence rates were 100%. The best main reaction conditions are as follows: substrate concentration, 16 mmol/L; color reaction time, 20-25 min; amount of DNA for transfection, 1 microgram; cell numbers for each population, 1 x 10(5). CONCLUSION: Reporter gene method is a kind of very sensitive, specific and repeatable quantitative analysis for cell fusion and can be used in the studies on membrane fusion caused by any viruses.

Cell Fusion↗
PubMed2001

[Overexpression of p27(KIP1) induced by Bak gene leads to the arrest in G(1) phase of HCC-9204 cell line].

OBJECTIVE: To explore whether p27(KIP1) plays an important role in prolonging cell cycle in G(1) phase and leading to apoptosis of HCC-9204 cells. METHODS: A model of Bak-induced cell cycle arrest in G(1) phase and subsequent apoptosis was established. p27(KIP1) was obtained from the model and sequenced afterwards. A zinc inducible p27(KIP1) stable transfectant was constructed. The effects of inducible p27(KIP1) on cell growth and cell cycle arrest were examined in control pMD and pMD-KIP1 transfected HCC-9204 cells. Western blot was performed to evaluate the expression of p27(KIP1). RESULTS: The cell growth was reduced by 35% upon 48h of p27(KIP1) induction with zinc treatment as determined by trypan blue exclusion assay. p27(KIP1) caused cell cycle arrest at 24h after induction, with 40% increase in G(1) population. CONCLUSIONS: Bak may induce cell cycle arrest in G(1) phase through up-regulating expression of p27(KIP1). The inducible p27(KIP1)-expressing cells provide a model to assess p27(KIP1) function.

Apoptosis↗
PubMed2001

Peritoneal dialysis solutions disturb the balance of apoptosis and proliferation of peritoneal cells in chronic dialysis model.

The present study investigated variation in apoptosis and proliferation, and the balance between apoptosis and proliferation, for peritoneal mesothelial cells (MCs) after exposure to peritoneal dialysis solution (PDS) in vivo. We implanted 32 male Sprague-Dawley rats (4 groups; n = 8 in each group) with catheters and intraperitoneally infused the animals with 20 mL Dianeal 1.36%, 2.27%, or 3.86% (Baxter Healthcare Corporation, Deerfield, IL, U.S.A.) PDS twice daily for eight consecutive weeks, using saline as a control. At the end of the eighth week, samples of peritoneal membrane were fixed and sliced. Expression of apoptosis was checked with TUNEL kits (Boehringer Mannheim, Mannheim, Germany), and expression of proliferative cell nuclear antigen (PCNA) was checked by immunohistochemistry [streptoavidin-biotin-peroxidase complex (SABC) method]. The ratio of MC apoptosis to proliferation was measured from the same slices using the dual-stain combination of TUNEL and SABC. Cells positive for apoptosis and PCNA were counted for all samples by light microscopy in 50 consecutive grids (10 x by 40). Peritoneal dialysis solution was found to significantly induce MC apoptosis as compared with control at the end of the eighth week. The degree of apoptosis was proportional to the concentration of glucose in the PDS. The 1.36% PDS, but not the 2.27% or 3.86%, significantly stimulated the expression of PCNA. The degree of PCNA expression was negatively related to the glucose concentration of the PDS. The MC apoptosis: PCNA ratio was significantly higher for 3.86% and 2.27% PDS than for the control, but no significant difference was seen between 1.36% PDS and control. We conclude that glucose-based PDS may induce apoptosis and disturb the balance of MC apoptosis and proliferation, and that 1.36% PDS damages the balance less than does 2.27% or 3.86% PDS. These effects may be partly due to pH, calcium, hyperosmolality, and glucose degradation products (GDPs). Loss of balance between MC proliferation and apoptosis--induced by unphysiologic PDS--may be one of the major causes of peritoneal membrane failure during long-term continuous ambulatory peritoneal dialysis.

Animals↗
PubMed2001

[Relationship between water supply and consumption of main planting tree species of protection forests in loess area of western Shanxi Province].

Based on three years point-fixed observation, this paper analyzed the relationship between water supply and consumption of black locust(Robinia pseudoscacia L.) and Chinese pine(Pinus tabulaeformis Carr.), the main tree species of protection forests in the loess area of the western Shanxi Province. In April, May and June, the water supply was less than water consumption, while in raining season, the water supply was abundant, and the water storage in soil was increased. During dry seasons and years, more water consumption and less available water supply occurred in high-density stand, showing a serious water deficiency. The water deficiency was in order of south-facing slope > semi-south-facing slope > north-facing slope. The study shows that water consumption characters coefficient could be used as an index to indicate the growth pattern of trees, and the relationship between water supply and consumption.

Trees↗
PubMed2001

[Clinicopathologic analysis of ovarian serous and mucinous borderline tumors].

OBJECTIVE: To understand the clinicopathological features of ovarian borderline tumors and evaluate the significance of various histological appearances. METHODS: Forty-five patients with borderline tumors were analyzed retrospectively. The stage distribution was stage I, 34 patients, stage II, 4 patients and stage III, 7 patients. RESULTS: Forty-five cases of borderline tumors accounted for 25.4% of ovarian epithelial malignant tumors. The ratio of serous borderline tumors (SBTs) to mucinous borderline tumors (MBTs) was approximately 1:1.3. Nine of eleven SBTs with exophytic growth presented peritoneal implants, of which two were invasive and seven noninvasive. Two SBTs and 1 MBT recurred after 5, 4, and 1 years respectively. Thirty-three cases were followed from 2 to 9 years. The 5-year survival rate was 100% (Kaplan-Meir method). CONCLUSIONS: The prognosis of the SBTs is favorable. SBTs with exophytic growth are often associated with peritoneum implants.

Adenocarcinoma, Mucinous↗
PubMed2001

[Decomposition interaction of mixed litter between Chinese fir and various accompanying plant species].

Studies on the decomposition of mixed litter between Chinese fir and 8 accompanying plant species showed that the decomposition of Chinese fir litter was promoted to different degrees by 8 mixed plant species, in which Angiopteris fokiensis had the greatest effect, while Schima superba had certain promotion first, but then, weak inhibition. The order of promotion was Angiopteris fokiensis > Maesa japonica > Ficus simplicissima > Woodwardia japonica > Boehmeria nivea > Castanopsis fargesii > Castanopsis fissa > Dicranopteris dicotoma. Chinese fir litter had a certain inhibition to litter decomposition of Schima superba and Castanopsis fissa, and certain promotion to litter decomposition of Castanopsis fargesii, but the interactions were not significant. There existed an interaction between Chinese fir and some plant species in the course of mixed decomposition. Therefore, rational protection and restoration of understory plant was important to fasten nutrient cycling of Chinese fir plantation ecosystem and to maintain soil fertility.

Abies↗
PubMed2001

Immune responses to the expressed products of the CSP antigen gene of plasmodium falciparum southern China isolate FCC1/HN in Hela cell.

OBJECTIVE: To construct a eukaryotic expression system with pcDNA3-PfCSP/Hela for the Circumsporozoite protein (CSP) gene of Plasmodium falciparum (P. falciparum), to observe the immune responses in BALB/c mice induced by the expressed proteins. METHODS: The recombinant plasmid pcDNA3-PfCSP was transformed into the Hela cell line. The expressed protein was isolated and analyzed by using SDS-PAGE and used for immunization of BALB/c mice by subcutaneous, intravenous, and intraperitoneal administration. Enzyme-linked immunosorbent assay (ELISA), Dot-ELISA, Western blot, T lymphocyte proliferation test, natural killer cell (NKC) activity assay, and CD4+ and CD8+ T cell detection were used for observation of humoral and cellular immune responses. RESULTS: Immune sera strongly reacted with the expressed protein, antibody titer was up to 1:6400 as detected by ELISA. Western blot analysis revealed a specific band at 38.3 Kda. When the spleen cells of normal and immunized BALB/c mice were specifically stimulated with expressed protein, the optical densities were 0.12 +/- 0.03 and 0.34 +/- 0.04, respectively. The latter were significantly higher than the former (P < 0.01). We used the MTT colorimetric assay to measure NKC activity of mice spleen. The results showed that the NKC activity of immunized BALB/c mice was remarkably higher than that of the controls (P < 0.05). CD4+ and CD8+ T cells were detected by using monoclonal antibody immunofluorescence methods. The results showed that the percentage of CD4+ and CD8+ T cells of immunized group were significantly higher than that of control group (P < 0.05). CONCLUSIONS: The humoral and cell-mediated immune responses and elevated NKC activity to products made with a eukaryotic expression system could be specifically detected in BALB/c mice. These findings indicate that the expressed protein could enhance the immune function in mice.

Animals↗
PubMed2001

Vitamin D receptor and PCNA expression in severe parathyroid hyperplasia of uremic patients.

OBJECTIVE: To clarify the role of vitamin D receptor (VDR) expression in parathyroid proliferation and resistance of parathyroid glands to 1,25(OH)2D3 with secondary hyperparathyroidism (SHPT). METHODS: This study used archive parathyroid with 7 uremic patients. The expression of proliferation cell nuclear antigen (PCNA) and VDR was evaluated in nineteen-surgically excised parathyroid tissues, including 11 diffuse hyperplasia (DH-type) and 8 nodular hyperplasia (NH-type) of parathyroid glands, by immunohistochemistry (avidin-biotin complex method). RESULTS: The weight of parathyroid in SHPT was remarkably increased by 16.1 times. The numbers of parathyroid cells were increased by 1.86 times. The rate of PCNA was remarkably increased in parathyroid hyperplasia with SHPT compared with that in control group [(6.35 +/- 3.36)@1000 vs (1.73 +/- 1.31)@1000, P < 0.001]. The number of PCNA in DH-type was lower than that in NH-type (P < 0.001). The density of VDR in the parathyroid with SHPT was significantly decreased [(40.28 +/- 13.13)% vs (83.79 +/- 3.77)%, P < 0.001], VDR immunoreactivity expression in NH-type was lower than that in DH-type [(27.14 +/- 4.12)% vs (49.84 +/- 7.33)%, P < 0.001]. A significantly negative correlation was found between VDR density and the weight of the parathyroid (r = -0.46, P < 0.05), the same as VDR and PCNA (r = -0.75, P < 0.001). CONCLUSION: VDR density was significantly decreased in parathyroid tissue of uremic patients showing nodular hyperplasia compared with that in diffuse hyperplasia and there was significantly negative correlation between VDR density and the weight of the parathyroid, and this may contribute to the progression of SHPT. Furthermore, VDR deficiency may cause the resistance of parathyroid cells to 1,25(OH)2D3, in part.

Adult↗
PubMed2001

[Appraisal of renal failure reversing therapies in lupus nephritis].

OBJECTIVE: This study aimed to explore the therapies of reversing renal failure in lupus nephritis. METHODS: The research strategy was a retrospective cohort study. 173 patients were included in the study. All of them were consecutive in-patients of newly diagnosed renal failure (serum creatinine > 180 micromol/L) with lupus nephritis from 1991 to 1999 in the university hospital. The research factors included steroids, cyclophosphamide and cyclosporin. Steroids were divided to oral prednisone, intravenous dexamethasone and intravenous methylprednisolone pulse; cyclophosphamide dose intensity was divided into three grades: none, low dose (average dose 0.25 g/m(2) body surface area per week). 51 demographic, clinical and laboratory data were included in the study as possible confounding factors. The study end-point was recovery of renal function that was defined as a level of serum creatinine <or= 116 micromol/L in the azotemia patients or a 50% reduction of serum creatinine and discontinuation of dialysis in the uremic patients. The improvement had to be maintained for at least three months. Collection of the study factors and outcome variable was conducted by two separate, blinded groups of clinical specialists with two structured abstracting forms. RESULTS: The number of complete following up patients was 142 (82.1%). After over 6 months of following up, 93 cases (65.5%) recovered their renal function and 17 cases (12.0%) died. In COX proportional hazard regression model, cyclophosphamide therapy was significantly associated with the recovery of renal function. The adjusted hazard ratio (HR) to recovery of renal function was 4.41, 95% CI = 1.03 - 18.94 in low dose; and the HR was 13.29, 95% CI = 3.11 - 56.82 in high dose cyclophosphamide therapy. The gender, duration of renal dysfunction, small renal size, severe anemia and serum creatinine were also significantly associated with renal function recovery. Cyclophosphamide therapy was not significantly associated with death. The variables associated with death were low level of serum albumin and edema. CONCLUSION: Cyclophosphamide pulse was an efficient therapy in reversing renal failure of lupus nephritis, especially in the patients with short duration of renal failure, non-small in renal size, and non-severe anemia.

Administration, Oral↗
PubMed2001

[Effects of seed coating formulation on seedling characters of Atractylodes macrocephala].

The effects of seed coating formulation (SCF) of Atractylodes macrocephala Koidz. on seedling in two experimental plots located in Hangzhou and Jiande were studied, and desinged with L9(3(4)) orthogonal comparison. The results showed that the SCF with paclobutrazol (pp333) had a significant effect on the rate of germination at Hangzhou plot, all factors had no significant effects on length of seedlings in both plots, and both atonik (sodium O-nitrophenolate) and PP333 on the fresh or dry seedling weight had significant effects.

Asteraceae↗
PubMed2001

Diagnosis and treatment of spinal fractures combined with paraplegia and diaphragm injury.

OBJECTIVE: To study the mechanism and treatment principle of spinal fractures combined with paraplegia and diaphragm injury. METHODS: A total of 16 patients (14 males and 2 females, aged from 18 to 50 years) with spinal fractures combined with paraplegia and diaphragm injury, receiving emergency treatment and admitted to our hospital in the past 20 years, were retrospectively analyzed in this study. RESULTS: The injuries were caused by direct or indirect violence. Six cases were of fractures of cervical spine combined with paraplegia and diaphragm injury, 2 of fractures of thoracic vertebra combined with paraplegia and diaphragm injury, and 8 of thoracolumbar fractures combined with paraplegia and diaphragm injury. Six cases received non-operative treatment, but died finally. Ten cases received spine surgical treatment, of which 4 died and 6 were improved. The total mortality rate was 62.5%. CONCLUSIONS: Spinal fractures combined with paraplegia and diaphragm injury are one of the most severe traumas in departments of orthopaedics. Paraplegia can be found easily, but diaphragm injury is often neglected and missed. When a patient suffers from both of them, he is in danger of death. What measures should be taken to rescue the patient's life depends on the severity of the wounds.

Adolescent↗
PubMed2001

Treatment of distal femoral nonunion and delayed union by using a retrograde intramedullary interlocking nail.

OBJECTIVE: To analyze the causes of distal femoral nonunion and delayed union and assess the outcome of the corresponding treatment, retrograde intramedullary interlocking nail (RIIN). METHODS: From June 1995 to December 1998, 15 patients (9 males and 6 females) with distal femoral nonunion and delayed union were treated with RIIN. The average age of the patients was 34.5 years (23-46 years). Bone grafting was performed in 10 patients, closed reaming was done in the other 5 patients. Correction osteotomy was performed in 2 patients, and intra-articular release of knee adhesion in 11 patients. X-ray examination and knee society clinical rating system (KSS) were used to evaluate the results. RESULTS: All fractures were followed up for at least 9 months with average follow-up duration of 14.5 months (9-33 months). Solid union was documented in all patients at 6.4 months on average. There were no infections or malunions in this series. Based on the final follow-up data, acceptable functional range of motion (ROM) of over 90 degrees was achieved in most patients. The average ROM was 93.5 degrees with significant improvement of 28 degrees (42.7%, P<0.05) compared with the preoperative ROM. The average knee score was 96. Excellent ROM emerged in 13 patients. The knee function score was 90.5 on average. CONCLUSIONS: The main causes of distal femoral nonunion and delayed union are improper indications and improper use of the implants. RIIN is an effective alternative for treatment of distal femoral nonunion and delayed union because it can provide a stable and reliable fixation which is beneficial for early functional exercise of knee. Bone grafting, closed reaming and intra-articular release of knee adhesion should be considered in order to enhance the bone healing and improve ROM and the knee function.

Adult↗
PubMed2001

[Preliminary study on the time of first appearance of "lanhousha" (scarlet fever)].

There are controversies about the problem of the source of "lanhousha" (scarlet fever) in the field of modern medical history, whether it is an epidemic appeared from the ancient time in our country or imported from other countries. Now, almost all researches were carried out around the classic medical books, especially "Medical Records of Ye Tianshi", and hardly dealing it in a historical context at that time. Through contrastive analysis between the records in medical books and historical facts, it is concluded that Ye Tianshi's records of scarlet fever have nothing to do with Ye Tianshi himself, and is by author of allonym. It perhaps was exogenous cold diseases spread when a severe epidemic diseases happened at Southern Jiangsu in the 11th year of Yongzheng reign. Even though there was some scarlet fever, it was not the first spread of scarlet fever in fact. Actually, in late Kangxi reign, scarlet fever was regarded as an epidemic disease seldom seen at Southern Jiangsu.

China↗
PubMed2001

[Research and establishment of the computerized orthodontic and orthopedic prediction system].

OBJECTIVE: The aim of this study was to develop a computerized orthopedics and orthodontics interactive prediction system and verify its reliability. METHODS: 24 cases of Angel II division I patients were selected in the study. All of them had been treated by activator or Frankel functional appliance, and had the satisfied therapy result. Both pre and post-treatment cephalogram of them were used verifying veracity of therapy prediction. RESULTS: All of cephalometric measure items include 11 angle measure items and 14 distance measure items. There were 9 coincidence indicators in angle measure items and 7 in distance measure items. CONCLUSION: The results indicate it is liable and effective to use the computerized orthopedics and orthodontics system for prediction.

Activator Appliances↗
PubMed2001

[Establishment and research of the computerized profile and photo prediction system].

OBJECTIVE: The study aims to develop a lateral oral facial profile and photo prediction system and then to verify its reliability. METHODS: 24 paired lateral cepholagrams in both pre- and post-treatment were selected and analyzed by three soft tissue cephalometric analysis methods in this study. All cases were of the angel II division I malocclusion, and had been successfully treated with the orthopedics therapy by activator or Frankel appliance. Soft tissue profile prediction had been automatically completed, following the hard tissue interactive orthopedics prediction approach in the pretreatment lateral cephalogram, and the predictive results were compared to the same cepholametric analysis in post-treatment cephalogram. RESULTS: There are 19 coincidence indicators in 30 measurements of three soft tissue cephalometric analysis, and 7 in 9 angel measurements, 10 in 18 instance measurements, 2 in 3 instance ratio measurements is consistency, respectively. CONCLUSION: The results indicate that the lateral oral facial profile and photo prediction system is effective in profile prediction.

Activator Appliances↗
PubMed2001

[Preparation of restricted-access media--alkyl-diol silica (ADS) by an improved method].

Alkyl-diol silica (ADS) is a kind of restricted-access media, which can be used for direct injection and analysis of complex biological samples containing bio-macromolecules. A new economical procedure has been developed to prepare ADS packing. At first gamma-glycidoxypropyl group was coupled onto the surface of microporous silica gel (Develosil 60-5 mu) to form epoxy-silica. Prepared epoxy-silica can react with stearic acid in organic solvent to prepare C18 ester-bonded reversed-phase packing. The packing was packed into a column and then the solution of pancreatic lipase was pumped into the column to create enzymoloysis reaction. The stearyl groups on the surface of packing can be removed by the enzymolysis to form a hydrophilic surface. At the same time, inner surface of micropore remains hydrophobic nature due to size exclusion effect of micropore to enzyme molecules. Chromatographic evaluations were carried out and the typical ADS behavior was confirmed.

Chromatography, High Pressure Liquid↗
PubMed2001

[The influence of type I collagen on the cell behavior of human embryonic periosteous osteoblasts].

OBJECTIVE: To study the influence of type I collagen (COL I) on the cell behavior of human periosteous osteoblasts (OB) and the application of type I collagen in constructing bioactive artifical bone. METHODS: OB were cultured on dishes coated with bovine type I collagen in different final concentrations. The cell adhesion was examined by the methods of cell count, the proliferation of OB was studied by 3H-TdR, and the osteoblastic ability was assessed by the synthesis of collagen, osteocalcin and alkaline phosphatase (ALP). RESULTS: OB cultured on type I collagen layer had the following characteristics: 1. The amounts of adhesive cells were maximal top in 25 micrograms/ml final concentration; 2. The proliferation of OB was decreased above 12.5 micrograms/ml final concentration (P < 0.05); 3. The synthesis of type I collagen was reduced slightly (above 25 micrograms/ml, P < 0.05); 4. The secretion of osteocalcin was increased markedly (above 6.25 micrograms/ml, P < 0.05, which reached maximally in 25 micrograms/ml); 5. The ALP activity was also increased (above 12.5 micrograms/ml, P < 0.05). CONCLUSION: Type I collagen promotes the expression of osteoblastic phenotype and cell adhesion. When the scaffold materials for bone tissue engineering are coated with type I collagen, the osteogenesis of OB is enhanced to accelerate the transformation course from artificial bone to biological bone, the best final concentration is 25 micrograms/ml.

Alkaline Phosphatase↗