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101.
个体化下肢小腿假肢接受腔设计的生物力学评价技术研究 总被引:3,自引:0,他引:3
作为传递体重、固定假肢的部件 ,接受腔对于小腿假肢使用的舒适性和方便程度有决定性的作用。本研究建立了基于有限元应力分析的小腿假肢生物力学评价技术平台 ,实现了小腿残端 /接受腔 3D几何建模与信息交互、三维有限元自动建模及应力分析。 3D模型与信息交互的实现基于得到广泛支持的OpenGL技术 ,有限元模型的构建采用了专门针对小腿残端 /接受腔结构特点的自动建模方法 ,通过构建档案数据库系统作为整个系统的操作平台。该技术平台可与现有的CAD/CAM系统相结合 ,为接受腔的个体化设计提供生物力学定量化依据。其临床应用将改善传统的设计流程 ,提高设计效率。同时 ,它也是未来构建接受腔设计专家 /智能系统的基础。 相似文献
102.
K.K.W. To C.C.Y. Yip C.Y.W. Lai C.K.H. Wong D.T.Y. Ho P.K.P. Pang A.C.K. Ng K.-H. Leung R.W.S. Poon K.-H. Chan V.C.C. Cheng I.F.N. Hung K.-Y. Yuen 《Clinical microbiology and infection》2019,25(3):372-378
Objectives
Automated point-of-care molecular assays have greatly shortened the turnaround time of respiratory virus testing. One of the major bottlenecks now lies at the specimen collection step, especially in a busy clinical setting. Saliva is a convenient specimen type that can be provided easily by adult patients. This study assessed the diagnostic validity, specimen collection time and cost associated with the use of saliva.Methods
This was a prospective diagnostic validity study comparing the detection rate of respiratory viruses between saliva and nasopharyngeal aspirate (NPA) among adult hospitalized patients using Xpert® Xpress Flu/RSV. The cost and time associated with the collection of saliva and nasopharyngeal specimens were also estimated.Results
Between July and October 2017, 214 patients were recruited. The overall agreement between saliva and NPA was 93.3% (196/210, κ 0.851, 95% CI 0.776–0.926). There was no significant difference in the detection rate of respiratory viruses between saliva and NPA (32.9% (69/210) versus 35.7% (75/210); p 0.146). The overall sensitivity and specificity were 90.8% (81.9%–96.2%) and 100% (97.3%–100%), respectively, for saliva, and were 96.1% (88.9%–99.2%) and 98.5% (94.7%–99.8%), respectively, for NPA. The time and cost associated with the collection of saliva were 2.26-fold and 2.59-fold lower, respectively, than those of NPA.Conclusions
Saliva specimens have high sensitivity and specificity in the detection of respiratory viruses by an automated multiplex Clinical Laboratory Improvement Amendments-waived point-of-care molecular assay when compared with those of NPA. The use of saliva also reduces the time and cost associated with specimen collection. 相似文献103.
Evidence for increased expression of eotaxin and monocyte chemotactic protein-4 in atopic dermatitis 总被引:7,自引:0,他引:7
Taha RA Minshall EM Leung DY Boguniewicz M Luster A Muro S Toda M Hamid QA 《The Journal of allergy and clinical immunology》2000,105(5):1002-1007
BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin disease associated with tissue eosinophilia and the activation of T lymphocytes. The novel eosinophil chemoattractants, eotaxin and monocyte chemotactic protein (MCP)-4, are up-regulated at sites of allergic inflammation, yet their contribution to the pathophysiologic mechanisms of AD remains to be determined. OBJECTIVE: We sought to investigate the expression of eotaxin and MCP-4 in acute and chronic lesions from patients with AD and to determine their relationship to the numbers of resident inflammatory cells. METHODS: With use of in situ hybridization, the expression of eotaxin and MCP-4 messenger RNA (mRNA) in skin biopsy specimens from patients with acute and chronic AD skin lesions was compared with that of uninvolved skin from these patients and skin from healthy volunteers. RESULTS: There was a constitutive expression of eotaxin and MCP-4 mRNA in skin biopsy specimens from healthy subjects. Positive signal for chemokine mRNA was observed both within the epidermis and inflammatory cells (macrophages, eosinophils, and T cells) of the subepidermis in AD skin lesions. Within the subepithelium acute and chronic skin lesions exhibited a significant increase in the numbers of eotaxin and MCP-4 mRNA-positive cells compared with uninvolved skin (P <.01), whereas the numbers of eotaxin and MCP-4 mRNA-positive cells were significantly higher in chronic AD compared with acute AD skin lesions (P <.005, P <.001, respectively). Correlations were observed between the expression of eotaxin and MCP-4 mRNA and the presence of eosinophils and macrophages, respectively, in AD lesions (r(2) = 0.84, r(2) = 0.94). CONCLUSION: There is an increased expression of eotaxin and MCP-4 in acute and chronic lesions, suggesting that these chemotactic factors play a major role in the pathophysiologic mechanisms of AD. 相似文献
104.
Wong N Hui AB Fan B Lo KW Pang E Leung SF Huang DP Johnson PJ 《Cancer Genetics and Cytogenetics》2003,140(2):124-132
Nasopharyngeal carcinoma (NPC) cell lines and xenografts represent valuable models for functional and therapeutic studies on this common malignancy in Southeast Asia. The karyotypic information in most NPC cell lines and xenografts, however, remains largely unclear to date. We have characterized the chromosomal aberrations in six commonly used human NPC cell lines and xenografts using the molecular cytogenetic technique of comparative genomic hybridization (CGH). Genomic imbalances identified in cell lines were further correlated with structural abnormalities indicated from spectral karyotyping (SKY) analysis. CGH revealed consistent overrepresentations of 8q (six out of six cases) with a smallest overlapping region identified on 8q21.1q22. Other common gains included 7p (4/6 cases), 7q (4/6 cases), 12q (4/6), and 20q (4/6 cases), where minimal overlapping regions were suggested on 7p15p14, 7q11.2q21, and 12q22q24.1. Common losses were detected on 3p12p21 (4/6 cases) and 11q14qter (4/6 cases). Although SKY analysis on cell lines revealed predominantly unbalanced rearrangements, reciprocal translocations that involved chromosome 2 [i.e., t(1;2), t(2;3), and t(2;4)] were suggested. Furthermore, SKY examination illustrated additional breakpoints on a number of apparently balanced chromosomes. These breakpoints included 3p21, 3q26, 5q31, 6p21.1p25, 7p14p22, and 8q22. Our finding of regional gains and losses and breakpoints represents information that may contribute to NPC studies in vitro. 相似文献
105.
Hormones increase mRNA of cyclic-nucleotide-gated cation channels in airway epithelia 总被引:1,自引:0,他引:1
Qiu W Laheri A Leung S Guggino SE 《Pflügers Archiv : European journal of physiology》2000,441(1):69-77
Previous studies have shown that the mRNA of cyclic-nucleotide-gated nonselective cation (CNG) channels is expressed in rat airway epithelia and that these channels contribute to sodium-mediated short-circuit currents in cultured rat tracheal epithelia. Patch-clamp studies from human A549 cells indicate that these channels contribute to cGMP-stimulated L-cis-diltiazem- and dichlorobenzamil-inhibited whole-cell sodium currents. This study demonstrates that mRNA for primary and secondary subunits of CNG channels, halphaCNG1 and hbetaCNG1 respectively, are expressed in several human airway cell lines, including normal and cystic fibrosis bronchial airway cells, in normal and cystic fibrosis tracheal airway cell lines and nasal polyp tissue from a cystic fibrosis patient. The mRNA of ralphaCNG1 in rat lung increased in response to increased circulating glucocorticoids and decreased in animals with lowered circulating glucocorticoids after aminoglutethimide treatment. Likewise the mRNA of halphaCNG1 increased in the presence of glucocorticoids in cultured alveolar airway cells. The mRNA of alphaCNG1 in rat lung was also increased in response to a low-salt diet and lowered in animals fed a high-salt diet. Likewise the mRNA of alphaCNG1 was increased in response to increased aldosterone and decreased in animals given spironolactone. These results suggest that mRNA for alphaCNG1 increases in response to elevated glucocorticoids or mineralocorticoids. Because alphaCNG1 is a functional sodium entry channel in both rat and human airway epithelial cells, if channel protein is also elevated this channel could mediate an increase in sodium absorption across lung epithelia in response to circulating hormones. 相似文献
106.
Mahadevaiah SK; Odorisio T; Elliott DJ; Rattigan A; Szot M; Laval SH; Washburn LL; McCarrey JR; Cattanach BM; Lovell-Badge R; Burgoyne PS 《Human molecular genetics》1998,7(4):715-727
An RNA-binding motif (RBM) gene family has been identified on the human Y
chromosome that maps to the same deletion interval as the 'azoospermia
factor' (AZF). We have identified the homologous gene family (Rbm) on the
mouse Y with a view to investigating the proposal that this gene family
plays a role in spermatogenesis. At least 25 and probably >50 copies of
Rbm are present on the mouse Y chromosome short arm located between Sry and
the centromere. As in the human, a role in spermatogenesis is indicated by
a germ cell-specific pattern of expression in the testis, but there are
distinct differences in the pattern of expression between the two species.
Mice carrying the deletion Yd1, that maps to the proximal Y short arm, are
female due to a position effect resulting in non-expression of Sry ;
sex-reversing such mice with an Sry transgene produces males with a high
incidence of abnormal sperm, making this the third deletion interval on the
mouse Y that affects some aspect of spermatogenesis. Most of the copies of
Rbm map to this deletion interval, and the Yd1males have markedly reduced
Rbm expression, suggesting that RBM deficiency may be responsible for, or
contribute to, the abnormal sperm development. In man, deletion of the
functional copies of RBM is associated with meiotic arrest rather than
sperm anomalies; however, the different effects of deletion are consistent
with the differences in expression between the two species.
相似文献
107.
Distribution of mutations in the PEX gene in families with X-linked hypophosphataemic rickets (HYP) 总被引:8,自引:0,他引:8
Rowe PS; Oudet CL; Francis F; Sinding C; Pannetier S; Econs MJ; Strom TM; Meitinger T; Garabedian M; David A; Macher MA; Questiaux E; Popowska E; Pronicka E; Read AP; Mokrzycki A; Glorieux FH; Drezner MK; Hanauer A; Lehrach H; Goulding JN; O'Riordan JL 《Human molecular genetics》1997,6(4):539-549
Mutations in the PEX gene at Xp22.1 (phosphate-regulating gene with
homologies to endopeptidases, on the X-chromosome), are responsible for
X-linked hypophosphataemic rickets (HYP). Homology of PEX to the M13 family
of Zn2+ metallopeptidases which include neprilysin (NEP) as prototype, has
raised important questions regarding PEX function at the molecular level.
The aim of this study was to analyse 99 HYP families for PEX gene
mutations, and to correlate predicted changes in the protein structure with
Zn2+ metallopeptidase gene function. Primers flanking 22 characterised
exons were used to amplify DNA by PCR, and SSCP was then used to screen for
mutations. Deletions, insertions, nonsense mutations, stop codons and
splice mutations occurred in 83% of families screened for in all 22 exons,
and 51% of a separate set of families screened in 17 PEX gene exons.
Missense mutations in four regions of the gene were informative regarding
function, with one mutation in the Zn2+-binding site predicted to alter
substrate enzyme interaction and catalysis. Computer analysis of the
remaining mutations predicted changes in secondary structure,
N-glycosylation, protein phosphorylation and catalytic site molecular
structure. The wide range of mutations that align with regions required for
protease activity in NEP suggests that PEX also functions as a protease,
and may act by processing factor(s) involved in bone mineral metabolism.
相似文献
108.
109.
Donald Y. M. Leung MD PhD Donna M. Ambrosino MD Robert D. Arbeit MD Julie L. Newton BS Raif S. Geha MD 《The Journal of allergy and clinical immunology》1988,81(6):1082-1087
Patients with the hyper-IgE (HIE) syndrome have recurrent bacterial infections with Staphylococcus aureus and other polysaccharide encapsulated organisms. To determine whether an impairment of the antibody response to polysaccharide antigens contributes to infections in this syndrome, we measured serum antibody to the teichoic acid of S. aureus and to the capsular polysaccharide of Haemophilus influenzae type b. Compared to control subjects who had no history of S. aureus infections (N = 14), sera from patients with HIE (N = 9) lacked the expected elevation of serum antibody to teichoic acid (p greater than 0.05) and had significantly lower levels of this antibody than sera from 14 patients with atopic dermatitis, complicated by recurrent cutaneous S. aureus infections (p less than 0.01). After immunization with the capsular polysaccharide of Haemophilus influenzae type of vaccine, the antibody response of patients with HIE was significantly impaired compared to that of age-matched control subjects (p = 0.01). Although patients with HIE syndrome had normal total IgG levels, most patients with HIE but not patients with atopic dermatitis had IgG2 subclass deficiency. Defective antibody responses in patients with HIE were not restricted to polysaccharide antigens because the serum levels of antitetanus toxoid antibody in these patients were significantly lower than that of control subjects (p less than 0.001). Impaired antigen-specific antibody responses in patients with HIE syndrome may contribute to their increased susceptibility to infection. 相似文献
110.
The effects of histamine on the spontaneous activity of the isolated human myometrium were studied. Both the frequency and force of contractions of the muscle strips were not significantly altered by histamine. The presence of either a histamine H1-or H2-receptor antagonist in the organ bath did not significantly change the responses of the uterine muscle to histamine. These findings suggest that histamine has negligible effects on the human myometrium, possibly due to the absence, or paucity, of histamine receptors. 相似文献