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71.
Overexpression of connexin43 alters the mutant phenotype of midgestational wnt-1 null mice resulting in recovery of the midbrain and cerebellum 总被引:1,自引:0,他引:1
Melloy PG Kusnierczyk MK Meyer RA Lo CW Desmond ME 《The anatomical record. Part A, Discoveries in molecular, cellular, and evolutionary biology》2005,283(1):224-238
The midbrain-hindbrain (MHB) junction plays a key role in the patterning of the embryonic neural tube and the formation of brain structures such as the cerebellum. The mitogen wnt-1 is critical for cerebellar development, as evidenced by the lack of MHB region and cerebellar formation in the wnt-1 null embryo. We have generated wnt-1 null embryos overexpressing the gap junction gene connexin43 by crossing wnt-1 null heterozygotes into the CMV43 mouse line. We have confirmed that these mice show an increase in gap junctional communication by dye coupling analysis. Two-thirds of wnt-1 null CMV43(+) mouse embryos at E18.5 have a cerebellum. In addition, changes in the wnt-1 null phenotype in mouse embryos overexpressing connexin43 are observed as early as E9.5. At this stage, one-quarter of wnt-1 null CMV43(+) embryos display extra or expanded tissue present at the MHB boundary (a wnt-1 null enlarged phenotype). In situ hybridization studies conducted on these embryos have indicated no changes in the expression of embryonic brain positional markers in this region. We conclude from these studies that overexpression of the connexin43 gap junction restores cerebellar formation by compensating for the loss of wnt-1. 相似文献
72.
R C Porter P Lo D E Low A E Simor A McGeer S Scriver T C Moore C Goldman M Skulnick 《Journal of clinical microbiology》1993,31(10):2794-2795
The BACTEC PLUS 26 (NR26) (Becton Dickinson, Towson, Md.) high-volume blood culture bottle replaced the less expensive smaller-volume NR6A bottle in our hospital. An audit carried out several months after their introduction revealed that only 17.5% of the NR26 bottles received the required blood volume. Several audits and educational programs were required in order to achieve a compliance rate of > 60%. 相似文献
73.
AIM: Development of a specific polymerase chain reaction (PCR) assay for detection of the pre-core, stop codon, mutant of hepatitis B virus (HBV). METHODS: PCR primers, specific at the 3'-end for nucleotide 1896 of either the pre-core, stop codon, mutant or wild type HBV, were synthesised using published sequence data. Positive control templates for both types of virus were synthesised by the PCR, incorporating sequences specific for each virus type at the appropriate position. These templates were used to optimise the specificity of the procedure. Formalin fixed, paraffin wax embedded human tissue from acute or fulminant HBV hepatitis from Hong Kong or Oxford was then investigated for presence of mutant or wild type virus. The HBV DNA was amplified from this tissue using a two step procedure, with an initial amplification phase followed by a second diagnostic phase on optimally diluted target DNA. RESULTS: Specific detection of mutant or wild type HBV was achieved. An important factor in determining specificity was the temperature of annealing, 70 degrees C proving to be highly specific. To overcome the inherent variation of target copy number in clinical samples and to provide an intrinsic positive control, it was important to generate and standardise the amount of target HBV used for the specific PCR. Two cases of fulminant hepatitis and four cases of acute hepatitis from Hong Kong, and one case of fulminant hepatitis from Oxford, contained only wild type HBV, with no evidence of a mutant virus. CONCLUSION: This method can be applied to FFPE tissues. It is rapid, non-radioactive, and specific for the stop codon mutation at nucleotide 1896 of HBV. Preliminary investigation of a small number of cases of fulminant hepatitis from Oxford and Hong Kong showed only wild type virus. The result differs from results published from Japan and Israel. 相似文献
74.
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76.
Rapid Cytomegalovirus pp65 Antigenemia Assay by Direct Erythrocyte Lysis and Immunofluorescence Staining 总被引:3,自引:3,他引:3 下载免费PDF全文
Stephen K. N. Ho Chi-Yuen Lo Ignatius K. P. Cheng Tak-Mao Chan 《Journal of clinical microbiology》1998,36(3):638-640
A rapid cytomegalovirus (CMV) pp65 antigenemia assay with direct erythrocyte lysis (DL) with 0.8% NH4Cl, followed by indirect immunofluorescence staining (IF), was evaluated with 82 blood samples from renal transplant recipients, and the results were compared to those of the conventional antigenemia assay with dextran sedimentation and two-cycle alkaline phosphatase, anti-alkaline phosphatase staining (DS-APAAP). The DL-IF modification gave a higher leukocyte yield compared to DS-APAAP (75.4 versus 54.9%; P < 0.05), with similar leukocyte viability rates of >95%. The DL-IF methodology involved fewer technical steps, and the assay time was shortened from 5 h to less than 3 h. Nineteen of the 82 samples concordantly tested positive for pp65 antigenemia by both assays, and the readings showed a good correlation (r = 0.996; P < 0.01). No discordant results were observed. We conclude that the CMV pp65 antigenemia assay by this novel DL-IF modification is technically simpler, cheaper, and less time-consuming but yields results comparable to those of the conventional DS-APAAP assay. The shortened assay time and increased capacity to handle more samples confer distinct advantages in the rapid diagnosis and prompt treatment of CMV disease in immunosuppressed patients. 相似文献
77.
Saulot V Vittecoq O Salle V Drouot L Legoedec J Le Loët X Godin M Ducroix JP Ménard JF Tron F Gilbert D 《Journal of autoimmunity》2002,19(1-2):55-61
To identify new autoantibody populations in patients with rheumatic diseases, a cDNA expression library was immunoscreened with a rheumatoid arthritis (RA) patient's serum which contains autoantibodies binding to uncharacterized polypeptides by Western-blotting. One clone encoding the amino-terminal region (Nt) [domain L and half of domain I] of human calpastatin was selected. Different fragments of the selected cDNA were prepared and the corresponding recombinant polypeptides were produced by in vitro translation and analysed by Western blotting. Most RA sera bound to recombinant amino-terminal region and domain I but not to domain L. This prompted us to use a recombinant polypeptide corresponding to the domain I of calpastatin as the antigen in a solid-phase ELISA to test sera from patients with various systemic rheumatic diseases and healthy controls.Anti-calpastatin domain I antibodies (ACAST-DI Ab), were detected by ELISA in RA, systemic lupus erythematosus (SLE), Sj?gren's syndrome and control sera at respective frequencies of 10, 9, 0 and 1%. These Ab did not have prognostic value in early RA; high levels were significantly associated with vasculitis in SLE. Antibodies reacting with the calpastatin amino-terminal region are produced during systemic rheumatic diseases and are predominantly directed against domain I. High levels of these Ab may constitute a marker of vasculitis in SLE. 相似文献
78.
The first clinical isolate of Legionella parisiensis, from a liver transplant patient with pneumonia. 总被引:1,自引:0,他引:1 下载免费PDF全文
F Lo Presti S Riffard F Vandenesch M Reyrolle E Ronco P Ichai J Etienne 《Journal of clinical microbiology》1997,35(7):1706-1709
A bluish white autofluorescent strain of Legionella was isolated from the tracheal aspirate of a female liver transplant patient who developed hospital-acquired pneumonia. This strain had biochemical characteristics compatible with those of L. cherrii, L. anisa, and L. parisiensis and could not be differentiated from L. bozemanii and L. parisiensis by the direct fluorescent-antibody assay. Phylogenetic analysis of partial 16S rRNA gene sequences of this strain (ATCC 700174) revealed the closest homology to the species L. parisiensis (99.5%). An L. parisiensis species-specific profile was also identified by a random amplified polymorphic DNA technique. This is the first report of L. parisiensis isolation from humans. 相似文献
79.
Chia-Ying Liu Chih-Cheng Lai Hsiu-Tzy Chiang Min-Chi Lu Ling-Fang Wang Tsai-Ling Tsai Mei-Yu Kang Yi-Ni Jan Yi-Ting Lo Wen-Chien Ko Shu-Hui Tseng Chun-Ming Lee Po-Ren Hsueh 《Journal of microbiology, immunology, and infection》2019,52(1):62-74
Background/purpose
This study investigated the distribution and persistence of multidrug resistant organisms (MDROs) including methicillin-resistant Staphylococcus aureus (MRSA), carbapenem-resistant Enterobacteriaceae (CRE), carbapenem-resistant Pseudomonas aeruginosa (CRPA), and multidrug-resistant Acinetobacter baumannii (MDRAB) in six long-term care facilities (LTCFs).Methods
We investigated the distribution of MDROs in residents of six LTCFs and their environments from January to December 2016 (intervention period). Active surveillance of colonization of MDROs was performed by culturing rectal and nasal swab samples from the residents every three months. Multilocus sequence typing (MLST) was conducted, and genes for panton-valentine leukocidin (PVL) from MRSA isolates were determined.Results
A total of 521 samples were positive for MDROs, and MRSA was the most common organism (65.1%), followed by MDRAB (11.3%), carbapenem-resistant Klebsiella pneumoniae (11.1%), carbapenem-resistant Escherichia coli (4.6%), and carbapenem-resistant P. aeruginosa (2.1%, n = 11). By a linear regression model, positive MRSA isolates from the environment were found to be statistically significant and associated with the number of colonized LTCF residents (p = 0.01), while the timing of the surveillance culture was not (p = 0.227). The main MLST types associated with PVL-production were sequence type (ST) 59, (40.0%, 24/60), ST30 (21.4%, 3/14), ST8 (87.5%, 14/16), and ST45 (3.6%, 1/28). The susceptibility rates of tetracycline (96.7%), trimethoprim-sulfamethoxazole (96.7%), and ciprofloxacin (81.7%) were statistically significant and higher in MRSA ST59, compared to the rates in MRSA ST45 isolates.Conclusions
MRSA was the most commonly colonized MDRO, both in the LTCF residents and in the environment, followed by MDRAB and carbapenem-resistant K. pneumoniae. 相似文献80.
Gaëlle Dzangué-Tchoupou Kuberaka Mariampillai Loïs Bolko Damien Amelin Wladimir Mauhin Aurélien Corneau Catherine Blanc Yves Allenbach Olivier Benveniste 《Autoimmunity reviews》2019,18(4):325-333