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51.
52.
Human MSH2 binds to trinucleotide repeat DNA structures associated with neurodegenerative diseases 总被引:5,自引:5,他引:5
The expansion of trinucleotide repeat sequences is associated with several
neurodegenerative diseases. The mechanism of this expansion is unknown but
may involve slipped-strand structures where adjacent rather than perfect
complementary sequences of a trinucleotide repeat become paired. Here, we
have studied the interaction of the human mismatch repair protein MSH2 with
slipped-strand structures formed from a triplet repeat sequence in order to
address the possible role of MSH2 in trinucleotide expansion. Genomic
clones of the myotonic dystrophy locus containing disease-relevant lengths
of (CTG)n x (CAG)n triplet repeats were examined. We have constructed two
types of slipped-strand structures by annealing complementary strands of
DNA containing: (i) equal numbers of trinucleotide repeats (homoduplex
slipped structures or S-DNA) or (ii) different numbers of repeats
(heteroduplex slipped intermediates or SI-DNA). SI-DNAs having an excess of
either CTG or CAG repeats were structurally distinct and could be separated
electrophoretically and studied individually. Using a band-shift assay, the
MSH2 was shown to bind to both S-DNA and SI-DNA in a structure- specific
manner. The affinity of MSH2 increased with the length of the repeat
sequence. Furthermore, MSH2 bound preferentially to looped-out CAG repeat
sequences, implicating a strand asymmetry in MSH2 recognition. Our results
are consistent with the idea that MSH2 may participate in trinucleotide
repeat expansion via its role in repair and/or recombination.
相似文献
53.
Parenteral Nutrition Is One of the Most Significant Risk Factors for Nosocomial Infections in a Pediatric Cardiac Intensive Care Unit 下载免费PDF全文
Roberta Netto MD Matteo Mondini MD Chiara Pezzella MD Lorenza Romani MD Barbara Lucignano MD Laura Pansani MD Patrizia D'argenio MD Paola Cogo MD PhD 《JPEN. Journal of parenteral and enteral nutrition》2017,41(4):612-618
Background: Nosocomial infections (NIs) are associated with significant morbidity and mortality and increased healthcare costs. We aimed to assess the NI epidemiology and associated risk factors in a pediatric cardiac intensive care unit (PCICU). Materials and Methods: Prospective observational study on 1106 patients admitted to a PCICU from January 1, 2012, to October 31, 2013. NIs were defined and recorded weekly by a multidisciplinary team. Independent risk factors for NIs were assessed by logistic regression analysis in the overall cohort, in cardiac surgical patients, and in those who had cardiopulmonary bypass (CPB). Results: Ninety‐two patients (8.3%) had NIs. Overall mortality was 2% but 8.3% in children with NIs (P < .001). The most frequent NIs were pneumonia (19.6%), bacteremia of unknown origin (16.3%), and catheter‐associated bloodstream infection (14.1%) caused mainly by Staphylococcus aureus and Pseudomonas aeruginosa. In the overall cohort, independent risk factors for NIs were number of days of parenteral nutrition (PN), days of invasive and noninvasive ventilation, ward before PCICU admission, and days of PCICU stay; in the cardiac surgical patients, the risk factors were days of PN and days of invasive and noninvasive ventilation; in children who had undergone CPB, the risk factors for NIs were days of PN, delayed sternal closure, reintervention, length of CPB, younger age, and days of invasive ventilation. Conclusion: Mortality was significantly higher in patients with NIs. The use of PN was one of the most significant predictors for NIs in the overall cohort of PCICU patients, cardiac surgical patients, and those who required CPB. 相似文献
54.
CE Medina-Solís M Mendoza-Rodríguez S Márquez-Rodríguez R De la Rosa-Santillana R Islas-Zarazua JdJ Navarrete-Hernández G Maupomé 《The West Indian medical journal》2014,63(4):354-358
Purpose:
The aim of this study was to determine the reasons for which erupted third molars (3M) are extracted in a sample of Mexican patients.Subjects and Methods:
A retrospective cross-sectional study was performed on a sample of 83 patients attending exodontia (minor oral surgery) clinics of a public university in Mexico (Autonomous University of Hidalgo State). The outcome variable was the reason for extractions using Kay and Blinkhorn''s classification. The independent variables were age, gender, arch and tooth number according to the World Health Organization (WHO). For statistical analysis, we used the Chi-squared test in Stata 9.0.Results:
Eighty-three patients underwent 150 3M extractions. Mean age was 38.67 ± 13.96 years, and 71.1% were female. The four reasons for 3M extraction were prosthetic (44.0%), followed by orthodontic (24.7%), dental caries (20.0%) and periodontal disease (11.3%). Differences were observed in the reasons for 3M extractions across age groups (p < 0.05). No significant differences existed between men and women (p > 0.05), or the WHO tooth number (p > 0.05).Conclusion:
Women and patients 18 to 34 years of age had erupted 3M extracted more frequently, primarily for prosthetic reasons. The age profile indicated a trend in demand for services that differ from those of overall tooth extractions, but not for the trend across gender. 相似文献55.
Centrilobular emphysema: CT-pathologic correlation 总被引:5,自引:0,他引:5
Foster WL Jr; Pratt PC; Roggli VL; Godwin JD; Halvorsen RA Jr; Putman CE 《Radiology》1986,159(1):27-32
Over a 5-year period, 25 patients who had undergone chest computed tomography (CT) died and were autopsied. Their lungs were fixed in the inflated state and were assessed for the presence and severity of centrilobular emphysema (CLE). Three radiologists independently evaluated the CT scans for nonperipheral low-attenuation areas, peripheral low-attenuation areas, pulmonary vascular pruning, pulmonary vascular distortion, and pulmonary density gradient. The CT criterion that best correlated with the presence and severity of CLE was the nonperipheral low-attenuation area. With this CT criterion, lung destruction was correctly identified in 13 of 15 cases. The absence of this criterion resulted in correct identification of eight of ten normal lungs. These preliminary data suggest that CLE can be reliably identified and quantified with current CT scanners. 相似文献
56.
The effects of oral doxofylline (400 mg BID) on bronchial airway mucosa were investigated in 14 patients with chronic obstructive bronchitis. The eligible patients had to have forced expiratory volume in 1 second > 60% of the predicted value and oxygen partial tension > 55 mm Hg. At the onset and the end of the study, bronchial biopsies were performed via a flexible fiberoptic bronchoscope. Chronic inflammation of the airways was graded according to absence of lesions = 0, involvement of 1-10% = 1, 10-50% = 2 and > 50% = 3. After three months of treatment, 57% of patients in the doxofylline group presented absence of lesions, while the remaining 43% exhibited advanced lesions. In the control group, absence of lesions was observed in 14%, while lesions of grade 1, 2 and 3 were visible in 14%, 29% and 43%, respectively. At histological examination, a significant difference in the degree of structural changes was observed in the doxofylline group between baseline and the end of the study (p < 0.03). In conclusion, doxofylline may induce favorable effects on inflammatory changes and altered cell proliferation of the airway mucosa in patients with chronic obstructive bronchitis. 相似文献
57.
Pulmonary embolism after hip or knee replacement: postoperative changes on pulmonary scintigrams in asymptomatic patients 总被引:1,自引:0,他引:1
Foley M; Maslack MM; Rothman RH; Casey MP; Lugano EM; Parry CE; Balderston RA; Booth RE Jr 《Radiology》1989,172(2):481-485
Serial pulmonary imaging has proved to be effective in the evaluation of patients undergoing total joint arthroplasty. A clinical dilemma arises in asymptomatic patients whose postoperative pulmonary images differ from the preoperative images. The authors prospectively evaluated 403 patients with serial imaging to determine the significance of changed postoperative images in asymptomatic patients undergoing total hip or knee arthroplasty. Twenty-two (5.5%) patients had significant changes on postoperative images. Seventeen were asymptomatic; all but one underwent pulmonary angiography. Documented pulmonary emboli were demonstrated in 100% of patients whose postoperative images changed to indicate a high probability of pulmonary embolism, 71% whose images changed to a moderate probability, and 0% whose images changed to indeterminate probability. Overall, pulmonary emboli occurred in 76% of all asymptomatic patients with significantly change postoperative images. Asymptomatic pulmonary embolism is a significant occurrence after total hip or knee repair, and a changed lung scan with appropriate clinical evaluation is an accurate indicator of pulmonary emboli in asymptomatic postarthroplasty patients. 相似文献
58.
预激态补骨脂素抑制 K562细胞增殖的实验研究 总被引:6,自引:0,他引:6
本研究的目的是观察预激态补骨脂素对K562细胞增殖的影响,为补骨脂素的临床应用提供实验依据。取预激态补骨脂素和晚激态补骨脂素处理的细胞,在培养后检测台盼蓝拒染细胞数和白血病细胞集落,并对它们在台盼蓝拒染细胞抑制率(TBIR)、细胞增殖抑制率(CPIR)和集落形成抑制率(CFIR)方面的差异进行比较。结果表明:预激态补骨脂素对K562细胞增殖有抑制作用;随着预激态补骨脂素浓度的增加,其抑制作用也随之增强;预激态补骨脂素与晚激态补骨脂素的TBIR、CPIR、CFIR各值比的差异不显著;为使预激态补骨脂素要充分发挥对K562细胞的抑制作用,补骨脂素的紫外线照射时间应在10分钟以上;与K562细胞作用时间也应大于12小时;抑制作用会因预激态补骨脂素预激后搁置时间的延长而下降,在6小时内作用最强。结论:预激态补骨脂素和晚激态补骨脂素对K562细胞的增殖均表现出抑制作用,有望作为临床的抗肿瘤用药。 相似文献
59.
Donor screening for antibody to hepatitis B core antigen and hepatitis B virus infection in transfusion recipients 总被引:10,自引:0,他引:10
JW Mosley ; CE Stevens ; RD Aach ; FB Hollinger ; LT Mimms ; LR Solomon ; LH Barbosa ; GJ Nemo 《Transfusion》1995,35(1):5-12
BACKGROUND: Testing for antibody to hepatitis B core antigen (anti-HBc) as a surrogate for hepatitis C viremia is no longer needed for blood donor screening. Currently, the important question is how much its use supplements hepatitis B surface antigen (HBsAg) donor screening in preventing transfusion-transmitted hepatitis B virus (HBV) infection. STUDY DESIGN AND METHODS: In a study conducted in the 1970s, 64 blood donors were associated with 15 cases of HBV (1.0%) in 1533 transfusion recipients. Sera from 61 donors at donation and 29 follow-up visits were available for present-day assays for HBsAg, HBV DNA, anti-HBc, and antibody to HBsAg (anti-HBs). RESULTS: HBsAg was found in four previously negative blood donors; HBV DNA was limited to three of these four. Anti-HBc was detected in six HBsAg-negative donors. Two other donors were negative in all assays at donation, but positive for anti- HBc and anti-HBs 2 to 4 months later. The remaining donors were negative for all HBV markers, which left five recipient cases unexplained. No HBV transmission was observed when anti-HBs sample-to- negative control values were > or = 10. CONCLUSION: Some 33 to 50 percent of cases of hepatitis B that could be transmitted by transfusion of blood from HBsAg-negative donors are prevented by anti- HBc screening. Anti-HBc-positive donors unequivocally positive for anti- HBs should be considered noninfectious for HBV and should be allowed to donate. Anti-HBc screening of paid plasmapheresis donors, supplemented by anti-HBs testing, would reduce the amount of HBV to be processed by virus inactivation and increase the content of anti-HBs in plasma pools. 相似文献
60.
Percutaneous umbilical blood samples (PUBS), obtained under ultrasound guidance, are used for prenatal diagnosis and management of hemolytic disease of the newborn (HDN) and other fetal disorders. Rapid testing at the time of sampling is vital to distinguish fetal from maternal blood. Blood typing was performed by slide technique in the treatment room during 38 procedures on 25 patients. Anti-I was used to test 50 presumed PUBS; venous I-positive maternal blood was tested in parallel. Because anti-I cannot detect fetal blood after umbilical vein transfusion (UVT) of I-positive donor blood, ABO and Rh blood typing reagents were used to test 29 samples when maternal and fetal or donor blood groups differed. Monoclonal reagents were used for optimal detection of weak AB antigens in fetal blood. Avid, chemically modified anti-D was used for Rh typing. Blood typing showed 27 (34%) of 79 samples to be maternal blood. Fetal blood was obtained in 8 of 10 cases investigated for fetal disorder and in 16 cases of potential HDN (anti-D, 5; -CD, 5; -cE, 2; -K, 2; -c; -E). The absence of HDN (antigen-negative fetus) was determined in 4 cases. UVT afforded live birth of 9 of 10 infants with HDN and was not indicated in two cases. 相似文献