Biomedical subjects

Wei Sun

Publications and source records attributed to Wei Sun.

At least 109 records · Page 6Linked to original sources

PubMed2005

[Effect of nano-hydroxyapatite collagen bone and marrow mesenchymal stem cell on treatment of rabbit osteonecrosis of the femoral head defect].

OBJECTIVE: To evaluate the effect of nano-hydroxyapatite collagen (nHAC) bone and marrow mesenchymal stem cells (MSCs) on the treatment of rabbit osteonecrosis of the femoral head (ONFH) defect. METHODS: From June to October 2004, animal models of ONFH defect were established in 45 New Zealand rabbits. They were divided into 3 groups randomly: In group A, as the control group, defect was not filled with any implants; In group B with nHAC; In group C with nHAC+MSC. Imaging and histological observation were made 4, 8, 12 weeks after operation. RESULTS: group C had a better osteogenesis ability than group B and group A. group B had a better osteogenesis ability than group A. Obvious new bones and osteogenesis were observed in group C 4 weeks after operation. The defect areas in group C were almost repaired 12 weeks after operation. CONCLUSION: nHAC has a better effect of osteo-conduction and it is a superior material for repairing bone defect of ONFH and of great value in treating ONFH when compounded with MSCs.

Animals↗

PubMed2005

[Preliminary experiences in minimally invasive and mini-incision surgery total hip arthroplasty for late osteonecrosis of the femoral head].

OBJECTIVE: To explore the effect of minimally invasive and mini-incision surgery (MIS) in total hip arthroplasty (THA) on late osteonecrosis of femoral head (ONFH). METHODS: From March 2003, Eighteen patients (22 hips) with ONFH underwent MIS in THA. Their ages ranged from 24 to 57 years, including 13 males and 5 females. The mean body mass index ranged from 17.1 to 30.1 (24.6 on average). The Harris hip score was 46 points before operation. Modified posterior-lateral approach was adopted, and the MIS THA was performed by cementless prosthesis. As a comparison, 18 patients (22 hips) were performed by conventional THA at the same period. The data, including bleeding volume during operation, incision length, operative time, and postoperative function recovery, were compared. RESULTS: Follow-ups were done for 6 to 20 months (11 months on average). Dislocation occurred in one patient that underwent conventional THA 2 days after operation. No complication occurred in MIS THA group. The incision lengths ranged from 8.7 to 10.5 cm (9.3 cm on average) in MIS THA group, being statistically different (P< 0. 01). There was no significant difference in Harris scoring of the function between the two groups both before the operation and after the operation (P>0.05). The operative time was almost the same, but the bleeding volume in MIS THA group was less (P<0.05). The function recovery was faster in MIS THA group. CONCLUSION: The MIS THA is an alternative to the treatment of late ONFH. The advantages of MIS THA are fewer trauma, less bleeding volume, and faster recovery. The MIS THA should be performed by surgeons with rich experiences in THA and hospitals with necessary instruments.

Adult↗

PubMed2005

[Preventive effect of multi-glycoside of tripterygium Wilfordii Hook. f. on proteinuria and mesangial injury in experimental mesangial proliferative glomerulonephritis].

OBJECTIVE: To observe the preventive effect of multi-glycoside of Tripterygium Wilfordii Hook. f. (GYW) on proteinuria and mesentery injury in experimental mesangial proliferative glomerulonephritis in vivo. METHODS: The reversible anti-Thyl.1 antibody glomerulo nephritis model of rats was established with monoclonal antibody 1-22-3 and intervened with GTW, and a control group was set up in the same time. Changes of 24h urinary protein excretion, serum creatinine (Scr), blood urea nitrogen (BUN), total plasma protein (TP) and glomerular morphology were observed, and the level of mRNA expression of proliferative factors, including platelet-derived growth factor-BB (PDGF-BB) and transforming growth factor-beta (TGF-beta), in renal tissue was determined. RESULTS: GTW could inhibit proteinuria and mesangial injury in anti-Thyl. 1 antibody nephritis model. The PDGF-BB and TGF-beta mRNA expression in the anti-Thy1.1 antibody nephritis model rats were increased for 2.84 and 1.64 times respectively to those in the normal control group. GTW could down-regulate the over-expression of PDGF-BB mRNA by 33.1%, it was significantly different to that in the control group (P < 0.05). CONCLUSION: GTW could reduce the proteinuria and inhibit mesangial cells proliferation and extracellular matrix deposition, these effects maybe related to the down-regulating of PDGF-BB mRNA expression.

Animals↗

PubMed2005

Multivariate analysis of relationships between iodine biological exposure and subclinical thyroid dysfunctions.

OBJECTIVE: To assess the relationships between iodine biological exposure and subclinical thyroid dysfunctions. METHODS: The cross-sectional survey was performed to obtain the epidemiologic data of population in three communities with different iodine biological exposure: mild iodine deficiency [median urinary iodine concentration (MUI) of 50-99 microg/L], more than adequate iodine intake (MUI of 200-299 microg/L), and excessive iodine intake (MUI over 300 microg/L). Univariate and multivariate analysis (logistic regression analysis) were used to analyze the risk factors of subclinical hypothyroidism and subclinical hyperthyroidism. RESULTS: Logistic regression analysis with sex and age controlled suggested that more than adequate iodine intake (OR = 3.172, P = 0.0004) and excessive iodine intake (OR = 6.391, P = 0.0001) increased the risk of subclinical hypothyroidism, while excessive iodine intake decreased the risk of subclinical hyperthyroidism (OR = 0.218, P = 0.0001). Logistic regression analysis including interaction of iodine intake and antibodies [thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb)] suggested that excessive iodine intake was an independent risk factor of subclinical hypothyroidism (OR = 6.360, P = 0.0001), but independent protect factor of subclinical hyperthyroidism (OR = 0.193, P = 0.0001). More than adequate iodine intake and it's interaction with TgAb increased the risk of subclinical hypothyroidism independently, in addition, it decreased the risk of subclinical hyperthyroidism at the present of TPOAb. CONCLUSION: Both excessive iodine intake and more than adequate iodine intake could increase risk of subclinical hypothyroidism, supplement of iodine should be controlled to ensure MUI within the safe range.

Adult↗

PubMed2005

[Fading spectrophotometric determination of heparin with brilliant cresyl blue].

A new fading spectrophotometric method for determining trace heparin is proposed in the present paper. In pH 3.0 Britton-Robinson (B-R) buffer solution, brilliant cresyl blue can react with heparin resulting in the decrease of absorbance of BCB at 592 nm. The conditions for the interaction were optimized, and the interferences of coexisting substances were investigated. Under the optimal conditions the reduction of the absorbance is proportional to the concentration of heparin in the range of 0.6-6.0 mg x L(-1) with the detection limit of 0.173 mg x L(-1). The molar absorptivity of the method was calculated to be 1.03 x 10(6) L x mol(-1) x cm(-1). The method has been applied to determine the heparin sodium injection solution with satisfactory results.

Amino Acids↗

PubMed2005

[Effect of bite force lost on the expression of iNOS in the rat periodontium].

PURPOSE: To investigate the molecular mechanism of the effect of bite force loss on periodontium remodeling. METHODS: For establishing a rat model of different bite forces for the study, the left maxillary molars of Wistar rats were extracted and the left mandibular molar area was used as the model of the bite force lost. The animals were sacrificed after 6 hours,1,2,3 days and 1,2,3,4weeks. The prepared tissue specimens were processed for the study of the change in the histologic morphology and the expression of iNOS protein in PDLC and osteoblasts with HE staining, immunohistochemistry and RT-PCR techniques, and the results were analyzed by one-way ANOVA,Dunnet t test and paired samples test. RESULTS: In the group of lost biting force, the derangement of periodontal ligament and resorption of alveolar bone were observed in histologic study: the structure of periodontal ligament deranged ,fibers and cells arrayed abnormally, there were many holes in the alveolar bone, even osteoclasts were present; the expression of iNOS was observed dramatically changed: the expression of iNOS in periodontal ligament fibroblasts and osteoblasts was higher than normal, especially at 2 days and 3 weeks,so as the results of RT-PCR.There was a significant correlation between bite force lost and the increased expression of iNOSmRNA. CONCLUSIONS: Bite force lost significantly increased the expression of iNOSmRNA in PDLC and osteoblasts, which suggests that iNOS may play an important role in the process of periodontium remodeling.

Alveolar Bone Loss↗

PubMed2005

Application of Bayesian regularized BP neural network model for analysis of aquatic ecological data-a case study of chlorophyll-a prediction in Nanzui water area of Dongting Lake.

Bayesian regularized BP neural network(BRBPNN) technique was applied in the chlorophyll-a prediction of Nanzui water area in Dongting Lake. Through BP network interpolation method, the input and output samples of the network were obtained. After the selection of input variables using stepwise/multiple linear regression method in SPSS 11.0 software, the BRBPNN model was established between chlorophyll-a and environmental parameters, biological parameters. The achieved optimal network structure was 3-11-1 with the correlation coefficients and the mean square errors for the training set and the test set as 0.999 and 0.00078426, 0.981 and 0.0216 respectively. The sum of square weights between each input neuron and the hidden layer of optimal BRBPNN models of different structures indicated that the effect of individual input parameter on chlorophyll-a declined in the order of alga amount > secchi disc depth (SD) > electrical conductivity (EC). Additionally, it also demonstrated that the contributions of these three factors were the maximal for the change of chlorophyll-a concentration, total phosphorus (TP) and total nitrogen (TN) were the minimal. All the results showed that BRBPNN model was capable of automated regularization parameter selection and thus it may ensure the excellent generation ability and robustness. Thus, this study laid the foundation for the application of BRBPNN model in the analysis of aquatic ecological data(chlorophyll-a prediction) and the explanation about the effective eutrophication treatment measures for Nanzui water area in Dongting Lake.

Bayes Theorem↗

PubMed2005

[Effects of different cutting system on main typical steppe populations in Inner Mongolia].

Twelve main typical steppe populations in Inner Mongolia were selected to investigate the effects of different cutting system on their aboveground standing biomass. The results showed that the test populations could be categorized into 3 groups, i.e., (1) group with decreasing biomass, which included Leynzus chinensis, Agropyron michnoi, Caragana microphylla and Carex korshinskyi, with L. chinensis and C. microphylla as the representatives. The average aboveground standing biomass of L . chinensis was decreased by 63.37%, 64.96%, 45.64% and 34.18% after 2 cuttings a year, 1 cutting a year, 1 year cutting and 1 year resting, and 2 years cutting and 1 year resting, while that of C. microphylla decreased by 81.79%, 63.33%, 40.29% and 26.30%, respectively, compared with the control; (2) group with increasing biomass, which included Koeleria cristata, Artemisia scoparia, A . frigida, and Salsola collina, and K. cristata and A . frigida were the representatives. The biomass of K. cristata was increased by 94.84%, 287.79%, 132.86% and 211.74%, while that of A. frigida was increased by 193.02%, 210.47%, 154.65% and 160.47%, respectively. The biomass increase of K. cristata and A. frigida was derived from their population changes, while that of A. scoparia and S. collina was come from the decrease of community densities and the more suitable conditions for seed germination; (3) group with fluctuated biomass, which included Stipa grandis, Achnatherum sibiricum, Artemisia commutata and Serratula centauroides, and the change patterns of their biomass were between those of the former 2 groups.

Animal Husbandry↗

PubMed2004

[Transtrochateric rotational osteotomy for osteonecrosis of the femoral head].

OBJECTIVE: To explore the indications, operative technique and clinical results of the transtrochanteric rotational osteotomy (TRO) for osteonecrosis of the femoral head (ONFH). METHODS: Nineteen patients (23 hips) with ONFH underwent TRO from October 1992 to May 2001 were reviewed. There were 14 males and 5 females. The age was ranging from 22 to 43 years old with an average age of 33.4 years old. The etiology were as followed: alcoholism 10 cases (12 hips); steroid 6 cases (7 hips); trauma 2 cases (2 hips); caisson disease 1 case (2 hips). Ficat stage: II 8 cases 8 hips; III 11 cases 15 hips. Harris hip score 46 to 74 with mean score 56 preoperatively. In order to determine the location and extent of osteonecrosis, A-P view and accurate lateral view (the film should be placed parallel to the femoral neck with the hip in precisely 90 degrees and flexion 45 degrees of abduction and neutral rotation) were taken in both hips preoperatively. The surgical technique described by Sugioka were used in all patients. RESULTS: Seventeen patients (19 hips) were followed up ranging from 18 to 11 years with mean 54 months. The Harris hip score was from 55 to 94 with mean 80.5. Fourteen hips score more than 80 and good to excellent rate was 73.2%. Harris score were less than 79 in 5 cases and 4 hips of these 5 hips were revised by total hip arthroplasty. The rotation angle was from 55 degrees to 80 degrees with mean 60 degrees . COMPLICATIONS: The circumflex femoral medial artery injury was found in 1 hip; subtrochanteric fracture was found in 2 hips and 1 osteotomy site nonunion occurred. CONCLUSION: TRO can be used to treat ONFH. The indications include: (1) younger patients (less than 45 years old). (2) Ficat stage II and III with more than one third intact articular surface of the femoral head. The better results could be obtained using posterior rotation and lager rotational angle. The Sugioka osteotomy should be used carefully because of its complicated surgical technique.

Adult↗

PubMed2004

[Acetabular component centralization in total hip arthroplasty for acetabular dysplasia].

OBJECTIVE: To explore the correct localization of the acetabular component, surgical technique and the outcome in total hip arthroplasty (THA) for acetabular dysplasia with secondary osteoarthritis. METHODS: A retrospective review was undertaken of 44 hips (38 patients) that had had a total hip arthroplasty for acetabular dysplasia with secondary osteoarthritis from September.1989 to April. 2003. 14 were male (one bilateral) and 24 patients were female (5 bilateral). The mean duration of clinical and roentgenographic follow-up was thirty-six months (range, eight to one hundred and sixty-eight months), and the mean age of the patients was fifty-one years (range, twenty-nine to eighty years). Twelve hips were classified as type I; twenty-four as type II; seven as type III; and one as type IV, according to the criteria of Crowe. The horizontal location of the center of the hip (the distance along the interior drop line extending lateral or medial from the inferior point of the teardrop to the perpendicular line dropped from the center of the femoral head) was measured. RESULTS: There were 24 acetabular components that were placed in the centralized position and the other 20 in no deepen placement post-operatively. At the most recent follow-up, the mean Harris hip score was 90.2, 86.3 for the centralized position and the undeepen placement hips respectively, there was a significant difference between these two groups. CONCLUSIONS: In order to obtain the stability of acetabular component, deepen acetabular reaming is necessary for the most acetabular dysplasia in THA. In this way the anatomical rotational center can be obtained medially and lowly. The excellent long-term function will be maintained.

Acetabulum↗

PubMed2004

Relationship between suicidal behavior of psychotic inpatients and serotonin transporter gene in Han Chinese.

Strong evidence indicates that central serotoninergic system dysfunction is associated with suicidal behavior. The relationship between the serotonin transporter protein (5-HTT) gene of psychotic patients in Han Chinese with suicidal behavior was studied since the 5-HTT plays an important role in serotoninergic transmission. Two hundred and seventy-two psychotic inpatients with suicidal behavior (suicide group) and 275 psychotic inpatients without suicidal behavior (patient control group) were recruited from six mental health facilities in Shanghai, China. Another 628 healthy adults (healthy control group) without suicidal behavior and mental disorder history were enrolled from Shanghai, China. All subjects were Han Chinese. The genotypes and the alleles of 5-HTT genes of the three groups were examined by PCR amplification. Neither the intron 2 variable number tandem repeat (VNTR) polymorphism and 5-HTTLPR (5-HTT gene-linked polymorphic region), nor the haplotype frequencies of this gene have significant differences between the suicide group and the two control groups. However, there was a significant difference in 5-HTTLPR polymorphism between inpatients with a first episode of suicidal behavior and those with recurrent suicidal behavior. Except for the possible heterogeneity between inpatients with a first episode of suicidal behavior and those with more than one, the 5-HTT gene was unlikely to be associated with suicidal behavior of psychotic patient in Han Chinese.

Adult↗

PubMed2004

Changes in NMDA receptor expression in auditory cortex after learning.

Extensive practice on auditory learning tasks dramatically alters the functional organization and response properties of neurons in the auditory cortex. The cellular mechanisms responsible for this auditory learning-induced cortical plasticity are unclear; however, changes in synaptic function involving NMDA receptors have been strongly implicated. To test this hypothesis, we measured the change in gene expression of NMDA receptors and associated proteins in the auditory cortex of adult rats trained to perform an auditory identification task. NMDA receptor 2A and 2B gene expression in auditory cortex decreased significantly as auditory discrimination improved whereas expression of Arc, an immediate early gene involved in memory stabilization, increased. These results suggest that changes in NMDA receptors 2A and 2B and Arc enhance synaptic plasticity, thereby facilitating experience-dependent cortical remodeling and auditory learning.

Adaptation, Physiological↗

PubMed2004

[Serial thin cross-sectional anatomy and computerized three-dimensional reconstruction of metacarpal fascial spaces of hand].

OBJECTIVE: To build three-dimensional (3-D) visible model for surgical treatment of infection of fascial spaces of hand. METHODS: Serial thin cross-sections (0.2 mm) of hand were made by cryomicrotome, and the thin cross-sections of metacarpal parts were observed. A personal computer was employed to reconstruct 3-D model of metacarpal fascial space. RESULTS: The shapes, locations and adjacent relations of the mid-palmar space, thenar space and metacarpal bones were displayed clearly from computerized 3-D model, which could be the cross-reference of the cross-sections expediently. CONCLUSION: The computerized 3-D reconstruction of metacarpal fascial spaces can provide some guidance for surgical treatment of infection and other diseases of metacarpal fascial spaces.

Anatomy, Cross-Sectional↗

PubMed2004

A system for enhancing genome-wide coexpression dynamics study.

Statistical similarity analysis has been instrumental in elucidation of the voluminous microarray data. Genes with correlated expression profiles tend to be functionally associated. However, the majority of functionally associated genes turn out to be uncorrelated. One conceivable reason is that the expression of a gene can be sensitively dependent on the often-varying cellular state. The intrinsic state change has to be plastically accommodated by gene-regulatory mechanisms. To capture such dynamic coexpression between genes, a concept termed "liquid association" (LA) has been introduced recently. LA offers a scoring system to guide a genome-wide search for critical cellular players that may interfere with the coexpression of a pair of genes, thereby weakening their overall correlation. Although the LA method works in many cases, a direct extension to more than two genes is hindered by the "curse of dimensionality." Here we introduce a strategy of finding an informative 2D projection to generalize LA for multiple genes. A web site is constructed that performs on-line LA computation for any user-specified group of genes. We apply this scoring system to study yeast protein complexes by using the Saccharomyces cerevisiae protein complexes database of the Munich Information Center for Protein Sequences. Human genes are also investigated by profiling of 60 cancer cell lines of the National Cancer Institute. In particular, our system links the expression of the Alzheimer's disease hallmark gene APP (amyloid-beta precursor protein) to the beta-site-cleaving enzymes BACE and BACE2, the gamma-site-cleaving enzymes presenilin 1 and 2, apolipoprotein E, and other Alzheimer's disease-related genes.

Alzheimer Disease↗

PubMed2004

AMASS: software for automatically validating the quality of MS/MS spectrum from SEQUEST results.

Time-consuming and experience-dependent manual validations of tandem mass spectra are usually applied to SEQUEST results. This inefficient method has become a significant bottleneck for MS/MS data processing. Here we introduce a program AMASS (advanced mass spectrum screener), which can filter the tandem mass spectra of SEQUEST results by measuring the match percentage of high-abundant ions and the continuity of matched fragment ions in b, y series. Compared with Xcorr and DeltaCn filter, AMASS can increase the number of positives and reduce the number of negatives in 22 datasets generated from 18 known protein mixtures. It effectively removed most noisy spectra, false interpretations, and about half of poor fragmentation spectra, and AMASS can work synergistically with Rscore filter. We believe the use of AMASS and Rscore can result in a more accurate identification of peptide MS/MS spectra and reduce the time and energy for manual validation.

Algorithms↗

PubMed2004

Recent origin of a hominoid-specific splice form of neuropsin, a gene involved in learning and memory.

Neuropsin is a secreted-type serine protease involved in learning and memory. The type II splice form of neuropsin is abundantly expressed in the human brain but not in the mouse brain. We sequenced the type II-spliced region of neuropsin gene in humans and representative nonhuman primate species. Our comparative sequence analysis showed that only the hominoid species (humans and apes) have the intact open reading frame of the type II splice form, indicating that the type II neuropsin originated recently in the primate lineage about 18 MYA. Expression analysis using RT-PCR detected abundant expression of the type II form in the frontal lobe of the adult human brain, but no expression was detected in the brains of lesser apes and Old World monkeys, indicating that the type II form of neuropsin only became functional in recent time, and it might contribute to the progressive change of cognitive abilities during primate evolution.

Alternative Splicing↗

PubMed2004

[Multifactor analysis of relationship between the biological exposure to iodine and hypothyroidism].

OBJECTIVE: To assess the relationship between the biological exposure to iodine and hypothyroidism. METHODS: Logistic regression model was used to analyze the risk factors of hypothyroidism, according to the epidemiologic data of 3761 adults in 3 kinds of rural communities: mild iodine deficiency area (4 natural villages in Panshan County, Liaoning Province), more than adequate iodine (7 natural villages of Zhangwu County, Liaoning Province), and excessive iodine area (2 natural villages of Huanghua City, Hebei Province). RESULTS: More than adequate iodine and excessive iodine were independent risk factors of subclinical hypothyroidism (OR = 3.172 and 6.391, P < 0.05) and overt hypothyroidism (OR = 3.696 and 9.213, P < 0.05). When interactions of iodine exposure and thyroid peroxidase antibody (TPOAb) or thyroglobulin antibody (TgAb) were included, more than adequate iodine was still a risk factor of subclinical hypothyroidism (OR = 2.788, P < 0.01), but had no such effect on overt hypothyroidism. Interaction of more than adequate iodine and positive TgAb significantly affected subclinical hypothyroidism and overt hypothyroidism (OR = 2.656 and 3.347, P < 0.05). CONCLUSION: More than adequate and excessive iodine exposure are independent risk factors of hypothyroidism. The risk of hypothyroidism grows up and thyroid dysfunction becomes more serious with the increasing of the biological exposure to iodine.

Adult↗

PubMed2004

Substance P inhibits potassium and calcium currents in inner ear spiral ganglion neurons.

Substance P (SP), a member of the tachykinin family of neurotransmitters and neuromodulators, has been identified on spiral ganglion neurons (SGNs) in the inner ear; however, its high affinity receptor, neurokinin-1 (NK1), has not been identified and the physiological effects of SP on SGNs are not well understood. To address these issues, immunolabeling, RT-PCR, Western blots and whole-cell patch-clamp recordings were made from SGNs in P0-P5 mouse cochlear organotypic cultures. The NK1 receptor was detected on SGNs by immunocytochemistry, the protein was detected in cochlear tissues by Western blots, and the mRNA for the NK1 receptor was also found in cochlear tissues of postnatal mice (P2) by RT-PCR. Application of SP (1 to 25 microM) significantly increased the latency of SGN action potentials (APs) (mean increase 7.8 +/- 4 ms; 25 microM of SP), prolonged the duration of the action potential and made the resting potential (RP) more positive (mean 9.0 +/- 7 mV) relative to normal values (-54 +/- 6 mV). SP (1 to 25 microM) also suppressed voltage-activated potassium currents (IK+) and calcium currents (ICa2+). Puffing 25 microM of SP onto SGNs suppressed IK+ by 43 +/- 9% (n = 7) and ICa2+ by 40.6 +/- 5.6% (n = 7); both currents recovered when SP was washed out. A SP antagonist blocked the SP-induced suppression of IK+ and ICa2+. These results indicate that SP acting through NK1 receptors can have direct neuromodulatory effects on SGNs.

Action Potentials↗