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Min Xu

Publications and source records attributed to Min Xu.

At least 55 records · Page 3Linked to original sources
PubMed2006

Gene functional research using polyethylenimine-mediated in vivo gene transfection into mouse spermatogenic cells.

AIM: To study polyethylenimine (PEI)-mediated in vivo gene transfection into testis cells and preliminary functional research of spermatogenic cell-specific gene NYD-SP12 using this method. METHODS: PEI/DNA complexes were introduced into the seminiferous tubules of mouse testes using intratesticular injection. Transfection efficiency and speciality were analyzed on the third day of transfection with fluorescent microscopy and hematoxylin staining. The long-lasting expression of the GFP-NYD-SP12 fusion protein and its subcellular localization in spermatogenic cells at different stages were analyzed with fluorescent microscopy and propidium iodide staining. RESULTS: With the mediation of PEI, the GFP-NYD-SP12 fusion gene was efficiently transferred and expressed in the germ cells (especially in primary spermatocytes). Transfection into Sertoli cells was not observed. The subcellular localization of the GFP-NYD-SP2 fusion protein showed dynamic shifts in spermatogenic cells at different stages during spermatogenesis. CONCLUSION: PEI can efficiently mediate gene transfer into spermatocytes. Thus, it might be useful for the functional research of spermatogenic-cell specific genes such as the NYD-SP12 gene. In our study, the NYD-SP12 protein was visualized and was involved in the formation of acrosome during spermatogenesis. Our research will continue into the detailed function of NYD-SP12 in spermatocytes.

Animals↗
PubMed2006

CD8 T cells mediate transient herpes stromal keratitis in CD4-deficient mice.

PURPOSE: To evaluate the role of CD4(+) T cells in the development of murine herpes stromal keratitis (HSK). METHODS: The corneas of wild-type (WT) BALB/c mice and three types of CD4-deficient BALB/c mice (CD4(-/-), CD4-depleted, CD4 and CD8 double-depleted) were infected with different doses of HSV-1 RE, and HSK incidence and severity were monitored. Corneal infiltrates were quantitatively and functionally assayed by flow cytometric analysis of individually digested diseased corneas and documented histologically. RESULTS: At a relatively high infectious dose (1 x 10(5) pfu/cornea): (1) CD4-deficient and WT BALB/c mice had severe HSK with a similar incidence (80%-100%), whereas HSK did not develop in mice deficient in both CD4(+) and CD8(+) T cells; (2) neutrophils were the predominate leukocyte in the corneas of CD4-deficient and WT mice; (3) the corneas of WT mice had activated, HSV-1-specific CD4(+) T cells, but few if any CD8(+) T cells; (4) the corneas of CD4-deficient mice had activated, HSV-1-specific CD8(+) T cells; and (5) HSK in CD4-deficient mice was transient, showing loss of CD8(+) T cells at 2 to 3 weeks after infection (pi) followed by a loss of neutrophils. At a relatively low infectious dose of HSV-1 (10(3) pfu/cornea) severe HSK developed in 80% to 90% of WT mice, but in only 30% to 40% of CD4-deficient mice. CONCLUSIONS: CD4(+) T cells preferentially mediate HSK, but, in their absence, a high infectious dose of HSV-1 can induce histologically similar but transient HSK that is mediated by CD8(+) T cells.

Animals↗
PubMed2006

Elevated serum levels of interleukin-18 are associated with insulin resistance in women with polycystic ovary syndrome.

Overproduction of proinflammatory factors is associated with obesity and diabetes. Interleukin (IL)-18 as a member of IL-1 cytokine family is increased in obese, in diabetic, and even in polycystic ovary syndrome (PCOS) patients. In the present study we evaluated the association of serum IL-18 levels with insulin resistance in PCOS women. Forty-two PCOS women and 38 control subjects were enrolled in this study and matched with respect to age and body mass index (BMI). Serum IL-18 levels and hormones were measured for all subjects. Furthermore, euglycemic hyperinsulinemic clamp test was performed in selected 30 PCOS women and 11 control subjects. Serum IL-18 levels were elevated in PCOS women compared with the control (p = 0.033). IL-18 levels were positively correlated with homeostasis model assessment index (HOMA) beta index, which assesses beta cell function (p = 0.035), but were inversely correlated with clamp indices, which best represent insulin resistance status: M, Clamp ISI*100, and MCRg values (p = 0.006, 0.010, and 0.009 respectively). No correlation was found between IL-18 and age, BMI, waist-to-hip ratio (WHR), lipid profile, dehydroepiandrosterone-sulfate (DHEAS), sex hormone- binding globulin (SHBG), or fasting insulin levels. In conclusion, in the present study, serum IL-18 levels were significantly increased in PCOS women and firmly associated with insulin resistance displayed by euglycemic hyperinsulinemic clamp test. It indicates that IL-18 may be a contributing factor linking inflammation and insulin resistance in PCOS women.

Blood Glucose↗
PubMed2006

Genotypic and environmental variation in cadmium, chromium, arsenic, nickel, and lead concentrations in rice grains.

Genotypic and environmental variation in Cd, Cr, As, Ni and Pb concentrations of grains, and the relationships between these heavy metals and Fe, Zn were investigated using 9 rice genotypes grown in 6 locations for two successive years. Significant genotypic variation was detected in the five heavy metal concentrations in grains, indicating the possibility to reduce the concentration of these heavy metals in grains through breeding approach. The environmental effect varied with metal, with Pb and Ni having greater variation than the other three metals. There was significant genotype-environment (location) interaction of the concentrations of all five heavy metals in grains, suggesting the importance of cultivar choice in producing rice with low heavy metal concentrations in grains for a given location. Correlation analysis showed that Cd and As, Cr and Ni, and As and Pb concentrations in rice grains were closely associated, and that Ni concentration in grains was negatively correlated with Zn concentration.

Arsenic↗
PubMed2006

[Surveillance and analysis of the pediatric pulmonary tuberculosis in new smear positive cases from 1992 to 2004 in China].

OBJECTIVE: To analyze the results of surveillance for new smear positive pediatric tuberculosis (TB) cases at the age of 0 to 14 years in China, to understand the trend of prevalence and finding of the new smear positive pediatric cases with TB, to illuminate the significance of surveillance for pediatric TB in TB epidemiology and to explore how to prevent and control pediatric TB with the modern TB control strategy (directly observed treatment, short-course, DOTS). METHODS: According to the register of new smear positive pediatric TB cases at the age of 0 to 14 years in the National Annual Surveillance Reporting from 1992 - 2004, the proportion of new smear positive pediatric TB cases among all the new smear positive TB cases in China, the notification rate of new smear positive pediatric TB, the case detection rate of new smear positive TB in the eastern, central and west parts of China, in Beijing, Tianjin and Shanghai municipalities and 13 provinces where the modern TB control strategies have been implemented in 1992 and 15 provinces where the strategies have not been implemented except Beijing, Tianjin and Shanghai municipalities, were analyzed. RESULTS: From 1992 to 2004, 31,358 new smear positive pediatric cases with TB at the age of 0 to 14 years were registered, among whom 14,727 were males (47%) and 16,631 were females (53%). The proportion of new smear positive pediatric TB cases among all the new smear positive TB cases was 1.26%, while the proportion among males was 0.89% and among females was 2.03%. The proportion among females was higher than that among males (P < 0.01). The notification rate of new smear positive pediatric cases with TB was between 0.42/100,000 and 1.08/100,000. Among the new smear positive pediatric TB cases, 44.9% were from western parts of China, followed by central and eastern parts of China and only 0.9% were from Beijing, Tianjin and Shanghai municipalities. Excluding Beijing, Tianjin and Shanghai municipalities, 13 provinces where DOTS was implemented since 1992 were compared with the other 15 provinces. The notification rate of new smear positive TB was respectively 75% and 25%. Western region of China was listed on the top in the proportion of new smear positive pediatric TB cases among all the new smear positive TB cases in every year. CONCLUSION: Among the registered new smear positive pediatric cases with TB, the number of females was higher than that among females and the proportion among males was also higher than that among males. The number of new smear positive pediatric TB cases in western parts of China was higher than that in central and eastern parts of China and the number in DOTS area was higher than that in non-DOTS area, which meant that the case detection of pediatric TB was associated with TB epidemic and DOTS strategy. Thus, in the implementation of DOTS, strengthening the prevention and control of pediatric TB, tracing the infection source of pediatric TB has certain impact on the TB epidemiological status.

Adolescent↗
PubMed2006

[Relationship of hypoxia-induced factor with tumor angiogenesis in early liver metastasis in colonic cancer].

OBJECTIVE: To study the relationships of hypoxia-induced factor (HIF) with tumor angiogenesis and early liver metastasis in colonic cancer. METHODS: Thirty three cases of colon cancer undergoing radical surgery were divided into two groups according to liver metastasis or not within half a year after operation. Expressions of HIF and vascular endothelial growth factor (VEGF) were examined using immunohistochemical method and tumor microvessel density (MVD) was measured in colonic cancer specimens. RESULTS: Fifteen cases developed early liver metastasis, while 18 did not. The positive rates of HIF and VEGF, and MVD were 86.7%, 66.7%, (57.9+/- 12.7)% respectively in the group with early liver metastasis, significantly higher than 44.4% (P< 0.05), 27.8% (P< 0.05) and (22.3+/- 10.2)% (P< 0.01) respectively in the group without early liver metastasis respectively. CONCLUSION: HIF can promote tumor angiogenesis in colonic cancer, and is closely related with early liver metastasis.

Adult↗
PubMed2006

[Cloning of the gene encoding a thermostable alpha-amylase from bacillus licheniformis CICIM B0204 and functional identification of its promoter].

Thermostable alpha-amylase, catalyzing the hydrolyzation of starch to dextrin, maltose and glucose at higher temperature, is one of the most industrial important enzymes. Several species of Bacillus have been found and genetic improved to produce the thermostable alpha-amylases. In present study, a gene, amyL, coding for a thermostable alpha-amylase with its flanking sequences was cloned from an industrial Bacillus licheniformis CICIM B0204 by using a combination of routine polymerase chain reactions (PCR) and inverse PCR with a pair of initial primers derived from the highly conserved region of bacterial alpha-amylase genes and the functional identifications of the cloned amyL and the activities of its promoter and signal peptide in Escherichia coli were investigated. The amyL was composed of 1539 bp with 180 bp at upstream for its promoter and 160 bp at downstream for its terminator. The deduced mature peptide of the a-amylase was composed of 512 amino acid residues and its signal peptide 29 amino acid residues at N-terminal. The nucleotide and deduced amino acid sequences of amyL were extremely similarity to those from Bacillus species with three amino acid residues difference (Arg163-->Leu, Ser339-->Gly, Ala349-->Ser) comparison to that from a laboratory strain B. licheniformis 584. Under the control of T7 promoter, the structural region of amyL was functionally expressed in Escherichia coli. Additionally, the structural region of the gene coding for a beta-mannosidase from B. licheniformis CICIM B2004 was inframely inserted into the downstream of the promoter and signal sequence of amyL and expressed in E. coli. The amyL promoter and signal sequence was functionally directed the expression and secretion of the beta-mannosidase in E. coli cells with the expression level of 295 U/mL.

Bacillus↗
PubMed2006

Cloning and characterization of a novel sperm tail protein, NYD-SP28.

In this study, a gene coding a novel human sperm tail protein named NYD-SP28 was cloned and characterized using a complementary DNA (cDNA) microarray. Its expression was 3.5 times higher in human testis than in fetal testis, and very high in human spermatozoa. The full length of NYD-SP28 cDNA was 1798 bp and encoded a 484-amino-acid protein. Motif analysis revealed that the protein contained a cluster of phosphorylation sites, N-glycosylation sites and N-myristoylation sites. Immunohistochemical analysis of normal human testes showed that NYD-SP28 was expressed in the cytoplasm of spermatogenic cells but not in interstitial cells. The EGFP-NYD-SP28 fusion protein was also localized in the cytoplasm of transfected 7721 cells. In human spermatozoa, NYD-SP28 immunoreactivity was detected in entire sperm tail. Using the two-dimensional (2-D) gel electrophoresis and immunoblotting technique, NYD-SP28 was found to be post-translationally modified during sperm capacitation. In conclusion, these results suggest that NYD-SP28 is a new human sperm tail protein and might play an important role during sperm capacitation.

Adult↗
PubMed2006

[Hematostatic function in myeloproliferative diseases].

This study was purposed to investigate the change of early hemostatic function in patients with myeloproliferative diseases (MPD) and to explore its significance in combination with clinical data. The platelet aggregative function was measured by using ristomycin, adenosine diphosphate, collagen and adrenine as inductors, the plasma von Willebrand factor-associated antigen (vWF: Ag) level was measured by enzyme-linked immunosorbent assay (ELISA), the plasma von Wellebrand factor-ristomycin cofactor (vWF: Rco) activity was measured in 6 patients with obviously low ristomycin induced platelet aggregation (RIPA). The results showed that the platelet aggregative function obviously decreased in 35 patients, there were distinct differences in maximal platelet aggregative rate between patients and normal controls induced by 4 inductors respectively (P < 0.001, P < 0.001, P = 0.002, P < 0.001). There was no obvious difference between patients with MPD and healthy controls in plasma vWF: Ag level (P > 0.50). Plasma vWF: Rco activity in all 6 patients with MPD chosen was in the normal range, except one patient with essential thrombocytosis (ET) whose plasma vWF: Rco activity was much lower than normal. No correlation was found between platelet count and plasma vWF: Ag level in the patients (r = -0.180). No correlation was found between platelet count and maximal platelet aggregative rate induced by 4 inductors respectively in patients. It is concluded that the occurrence of abnormal platelet aggregative function is high in patients with MPD. The RIPA and vWF: Rco activity decrease in one patient with ET. However, the shortage of vWF polymer existed in his plasma have needs for further research. No correlation was observed between hemostasis and clinical manifestations. However, because of the high occurrence of platelet dysfunction in MPD patients, the clinical application of anti-platelet drugs should be considered carefully.

Adolescent↗
PubMed2006

[Congenital unilateral malformations of lung referred as bronchial foreign bodies].

OBJECTIVE: To investigate the resemblances and differences of congenital unilateral malformations of lung and bronchial foreign bodies in clinical manifestation, physical sign and radiological examination, and to summarize the characteristics and to introduce diagnostic methods of the congenital unilateral malformations of lung. METHOD: Ten patients with the congenital unilateral malformation of lung, who were diagnosed the pulmonary atelectasis or the bronchial foreign body initially, were analyzed. Three typical cases were analyzed in details. RESULT: Four patients were confirmed by rigid bronchoscope. Four patients were confirmed by X-ray and high resolution CT of lung, one patient by high- resolution CT and 3D stereographs of lung, one patient by autopsy. Six cases were the congenital malformations of the right lung and 4 cases were the left lung. Three cases of them combined with congenital cardiovascular diseases and other malformations. CONCLUSION: There are many resemblances between the congenital unilateral malformation of lung and the bronchial foreign body in clinical manifestation and physical sign. The congenital unilateral malformation of lung was referred as the bronchial foreign body easily. Although it can be confirmed by rigid bronchoscope, the risk of the operation for these children was very high. So if the disease was considered, high resolution CT and 3D -stereographs of lung can make a definite diagnosis.

Adolescent↗
PubMed2006

[Comprehensive protocol for diagnosis and treatment of childhood neuroblastoma--results of 45 cases].

OBJECTIVE: The aim of the paper was to improve the prognosis of neuroblastoma (NB) stage III and IV in children through the comprehensive therapy including chemotherapy, delayed tumor resection, autologous stem cell transplantation (ASCT) and inducing differentiation and to analyze the factors affecting the prognosis. METHODS: Newly diagnosed neuroblastoma patients seen from Oct.1998 to Dec.2003 were divided into high, medium and low risk groups depending on clinical stage and age. Comprehensive protocol included accurate staging, delayed and/or second tumor resection for stage III and IV patients, chemotherapy of different intensity mainly composed of cell cycle nonspecific drugs and 13-cis-retinoid for inducing cell differentiation. ASCT was given at the end of therapy for high risk group. RESULT: Forty-five patients, 6 months to 11 years of age, 32 males and 13 females, were analyzed. Of them, 15 were found to have the tumor in adrenal gland, 12 had the tumor extended to the retro-peritoneal space, while in 15 cases the tumor was beside the spinal column in chest and in 3 the tumor was located in other places. Nine cases had stage I, 1 case had stage II, 8 cases had III, 26 cases had stage IV and 1 case had stage IVs of the tumor. Depending on the age and stage of the tumor, 26 cases were aligned into high risk protocol, 10 into medium risk and 9 into low risk groups. Thirty nine cases were treated as planned. Eleven of them received ASCT including 2 cases who received second ASCT. Of the thirty-nine patients, 31 achieved complete remission (CR) and 8 partial remission (PR) after surgery and/or chemotherapy. During up to 21 months median following up period (range 14 to 64 months), 24 cases (62%) kept CR (median 22 months) and 4 survived with stable disease. The survival rate (SR) was 72%. Eleven cases died of relapse and disease progression. No death occurred from treatment complication. Statistical analysis showed that the age older than 18 months, and stage III and IV of the tumor were the factors predicting poor prognosis (P = 0.04 and 0.003, respectively). Patients who had the tumor originated from the retroperitoneal space, who had incomplete tumor resection, and those who did not receive ASCT had poorer prognosis, but the differences were not significant (P = 0.092, 0.55 and 0.60, respectively). CONCLUSION: The comprehensive protocol seemed to be reasonable. Age older than 18 months, and stage III and IV were the factors suggesting poor prognosis. The origin of the tumor, completeness of tumor resection, and use of ASCT had no significant impact on the prognosis.

Age Factors↗
PubMed2005

[Withdrawal symptoms of ethanol are ameliorated by thymopentin in mice].

OBJECTIVE: To explore the effect of thymopentin (TP5) on the choice of ethanol and ameliorating withdrawal symptoms (anxiety) of ethanol in mice. METHODS: Mice were administered ethanol (v/v) in schedular fashion: 5% (1 week), 10% (1 week) and 15% (4 weeks), followed with the free choice between ethanol and water. Ethanol/(ethanol+water)x100% [E/(E+W)x100%] was measured as an index of ethanol selection. Light-dark box test and elevated plus maze test were chosen for the assessment of anxiety pre-drug and post-drug. After TP5 [0.2 mg/(kgxd), 0.4 mg/(kgxd)], i.p. or saline (vehicle control), i.p. for 14 days, the procedure was repeated. RESULT: (1) E/(E+W)x100%: the post-drug values of TP5 (0.2 mg/kg, 0.4 mg/kg) were lower significantly than the pre-drug values. (2) Light-dark box test: the post-drug values of number of entries and time spent in the light chamber of TP5 (0.2 mg/kg, 0.4 mg/kg) were more than the pre-drug values themselves and the post-drug value of saline. (3) Elevated plus maze test: the post-drug values of time spent on open arms of TP5 (0.2 mg/kg, 0.4 mg/kg) were more than the pre-drug values themselves and the post-drug value of salineìand the post-drug values of time spent on close arms of TP5 were less than the pre-drug values. CONCLUSION: TP5 could decrease the uptake of ethanol and ameliorate anxious behavior associated with ethanol withdrawal in mice.

Adjuvants, Immunologic↗
PubMed2005

Circular polarization memory of light.

Circular polarization memory of light multiply scattered by Mie particles is investigated. The mechanism of randomization of helicity is found, in general, to dominate light circular depolarization by particles of large size or a high refractive index while the mechanism of randomization of direction dominates for small particles of a lower refractive index. The characteristic length for circular polarized light to lose its helicity is determined for Mie scatterers of arbitrary size and refractive index and is used successfully to analyze circular depolarization of light transmission through a slab. Circular polarization memory of light is found to be most pronounced for not only large soft particles but also particles of smaller size and a high refractive index.

Journal Article↗
PubMed2005

Molecular mapping of k2 Mdh1-n y20, an unstable chromosomal region in soybean [Glycine max (L.) Merr.].

In the soybean genome, a chromosomal region covering three tightly linked genes, k2, Mdh1-n, and y20, was found very unstable. It was suspected that the instability of the k2 Mdh1-n y20 chromosomal region was caused by a non-autonomous transposable element residing adjacent to or in this region. In this study, we located and mapped this region with simple sequence repeat (SSR) markers on the soybean integrated map using five mapping populations. The k2 Mdh1-n y20 chromosomal region was located on molecular linkage group H. The integrated map from five mapping populations consisted of 13 loci in the order Satt541, Satt469, Sat_122, Satt279, Satt253, Satt314, Mdh1-n,y20, k2, Satt302, Satt142, Satt181, and Satt434. The k2 Mdh1-n y20 chromosomal region was very close to Satt314, Satt253, and Satt279. The genetic distance between the Mdh1-n gene and Satt314 was less than 1 cM. The results of the mapping study were consistent with the results from previous studies that the Mdh1-n mutation in T261 (k2 Mdh1-n) and the Mdh1-n y20 mutation in T317 (Mdh1-n y20) were caused by deletions. In addition, another putative deletion was found in the genome of T261 which covered three SSR markers (Satt314, Satt253, and Satt279).

Chromosomal Instability↗
PubMed2005

Puerins A and B, two new 8-C substituted flavan-3-ols from Pu-er tea.

Pu-er tea is a special treated fermented tea produced from crude green tea, which is prepared from the leaves of Camellia sinensis var. assamica. It is a traditional beverage having been used in China, particularly the southern areas, for a long time. Chemical investigation led to the identification of two new 8-C substituted flavan-3-ols, puerins A (1) and B (2), and two known cinchonain-type phenols, epicatechin-[7,8-bc]-4alpha-(4-hydroxyphenyl)-dihydro-2(3H)-pyranone (3) and cinchonain Ib (4), together with other seven known phenolic compounds, 2,2',6,6'-tetrahydroxydiphenyl (5), (-)-epicatechin-8-C-beta-d-glucopyranoside (6), (-)-epicatechin (EC) (7), (-)-epigallocatechin (EGC) (8), (+/-)-gallocatechin (GC) (9), gallic acid (10), and myricetin (11), in addition to caffeine (12). Their structures were determined by spectroscopic methods. The compounds 1-5, which might be formed in the postfermentative process of Pu-er tea, were isolated from tea and theaceous plants for the first time.

Camellia sinensis↗
PubMed2005

SHP-2 phosphatase regulates DNA damage-induced apoptosis and G2/M arrest in catalytically dependent and independent manners, respectively.

SHP-2, a tyrosine phosphatase implicated in diverse signaling pathways induced by growth factors and cytokines, is also involved in DNA damage-triggered signaling and cellular responses. We previously demonstrated that SHP-2 played an important role in DNA damage-induced apoptosis and G2/M cell cycle checkpoint. In the present studies, we have provided evidence that SHP-2 functions in DNA damage apoptosis and G2/M arrest in catalytically dependent and independent manners, respectively. Mutant embryonic fibroblasts with the Exon 3 deletion mutation in SHP-2 showed decreased apoptosis and diminished G2/M arrest in response to cisplatin treatment. Wild type (WT), but not catalytically inactive mutant SHP-2 (SHP-2 C459S), rescued the apoptotic response of the mutant cells. Interestingly, both WT and SHP-2 C459S efficiently restored the G2/M arrest response. Furthermore, inhibition of the catalytic activity of endogenous SHP-2 in WT cells by overexpression of SHP-2 C459S greatly decreased cell death but not G2/M arrest induced by cisplatin. Biochemical analyses revealed that activation of c-Abl kinase was decreased in SHP-2 C459S-overexpressing cells. However, DNA damage-induced translocation of Cdc25C from the nucleus to the cytoplasm was fully restored in both WT and SHP-2 C459S "rescued" cells. Additionally, we demonstrated that the role of SHP-2 in DNA damage-induced cellular responses was independent of the tumor suppressor p53. Embryonic stem cells with the SHP-2 deletion mutation showed markedly decreased sensitivity to cisplatin-induced apoptosis, attributed to impaired induction of p73 but not p53. In agreement with these results, DNA damage-induced apoptosis and G2/M arrest were also decreased in SHP-2/p53 double mutant embryonic fibroblasts. Collectively, these studies have further defined the mechanisms by which SHP-2 phosphatase regulates DNA damage responses.

Animals↗
PubMed2005

Classifying health-related quality of life outcomes of total hip arthroplasty.

BACKGROUND: Primary total hip arthroplasty (THA) is an effective treatment for hip osteoarthritis, assessed by whatever distribution-based measures of responsiveness. Yet, the group level evaluation has provided very little evidence contributes to our understanding of the large variation of treatment outcome. The objective is to develop criteria that classify individual treatment health related quality of life (HRQOL) outcome after primary THA, adjusted by preoperative scores. METHODS: We prospectively measured 147 patients' disease specific HRQOL on the date of consultation and 12 months post operation by Western Ontario McMaster Universities Osteoarthritis Index (WOMAC). Regression models were used to determine the "expected" outcome for a certain individual baseline score. The ceiling effect of WOMAC measurement is addressed by implementing a left-censoring method. RESULTS: The classification criteria are chosen to be the lower boundary of the 95% confidence interval (CI) of the estimated median from the regression. The robustness of the classification criteria was demonstrated using the Monte-Carlo simulation. CONCLUSION: The classification criteria are robust and can be applied in general orthopaedic research when the sample size is reasonable large (over 500).

Aged↗