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91.
The role of size, sequence and haplotype in the stability of FRAXA and FRAXE alleles during transmission 总被引:2,自引:5,他引:2
Murray A; Macpherson JN; Pound MC; Sharrock A; Youings SA; Dennis NR; McKechnie N; Linehan P; Morton NE; Jacobs PA 《Human molecular genetics》1997,6(2):173-184
Factors involved in the stability of trinucleotide repeats during
transmission were studied in 139 families in which a full mutation,
premutation or intermediate allele at either FRAXA or FRAXE was
segregating. The transmission of alleles at FRAXA, FRAXE and four
microsatellite loci were recorded for all individuals. Instability within
the minimal and common ranges (0-40 repeats for FRAXA, 0-30 repeats for
FRAXE) was extremely rare; only one example was observed, an increased in
size at FRAXA from 29 to 39 repeats. Four FRAXA and three FRAXE alleles in
the intermediate range (41-60) repeats for FRAXA, 31-60 for FRAXE) were
unstably transmitted. Instability was more frequent for FRAXA intermediate
alleles that had a tract of pure CGG greater than 37 although instability
only occurred in two of 13 such transmissions: the changes observed were
limited to only one or two repeats. Premutation FRAXA alleles over 100
repeats expanded to a full mutation during female transmission in 100% of
cases, in agreement with other published series. There was no clear
correlation between haplotype and probability of expansion of FRAXA
premutations. Instability at FRAXA or FRAXE was more often observed in
conjunction with a second instability at an independent locus suggesting
genomic instability as a possible mechanism by which at least some FRAXA
and FRAXE mutations arise.
相似文献
92.
Pied S; Voegtle D; Marussig M; Renia L; Miltgen F; Mazier D; Cazenave PA 《International immunology》1997,9(1):17-25
TCR V beta usage was examined in C57BL/6 mice infected with Plasmodium
yoelii. In addition to a polyclonal T cell activation, already described, a
superantigenic-like activity was observed during the acute infection. This
superantigenic activity induces a preferential deletion without prior
expansion of CD4+ and CD8+ T cells bearing the TCR V beta 9 segment. The
superantigen could be released by the parasite at different stages of its
development since the deletion of V beta 9+ T cells was observed in blood
and lymph nodes of mice infected either with sporozoites or with
erythrocytic stages. Injection of sporozoite or parasitized erythrocytes to
newborn mice led to a deletion and anergy of peripheral V beta 9+ T cells,
without affecting thymic T cell populations. These observations suggest
that the superantigen is released at very low concentrations during
parasite development. The role of such parasite superantigenic activity in
infectivity can be underlined by the observation that congenic BALB.D2
Mis1a mice lacking V beta 9 T cells are more susceptible to infection by P.
yoelii.
相似文献
93.
The vagus nerve,recurrent laryngeal nerve,and external branch of the superior laryngeal nerve have unique latencies allowing for intraoperative documentation of intact neural function during thyroid surgery 下载免费PDF全文
94.
AW El‐Hattab J Bournat PA Eng JBS Wu BA Walker P Stankiewicz SW Cheung CW Brown 《Clinical genetics》2011,79(6):531-538
El‐Hattab AW, Bournat J, Eng PA, Wu JBS, Walker BA, Stankiewicz P, Cheung SW, Brown CW. Microduplication of Xp11.23p11.3 with effects on cognition, behavior, and craniofacial development. We report an ~1.3 Mb tandem duplication at Xp11.23p11.3 in an 11‐year‐old boy with pleasant personality, hyperactivity, learning and visual‐spatial difficulties, relative microcephaly, long face, stellate iris pattern, and periorbital fullness. This clinical presentation is milder and distinct from that of patients with partially overlapping Xp11.22p11.23 duplications which have been described in males and females with intellectual disability, language delay, autistic behaviors, and seizures. The duplicated region harbors three known X‐linked mental retardation genes: FTSJ1, ZNF81, and SYN1. Quantitative polymerase chain reaction from whole blood total RNA showed increased expression of three genes located in the duplicated region: EBP, WDR13, and ZNF81. Thus, over‐expression of genes in the interval may contribute to the observed phenotype. Many of the features seen in this patient are present in individuals with Williams‐Beuren syndrome (WBS). Interestingly, the SYN1 gene within the duplicated interval, as well as the STX1A gene, within the WBS critical region, co‐localize to presynaptic active zones, and play important roles in neurotransmitter release. 相似文献
95.
Peter Kondrashov Dalton J. McDaniel Rebecca M. Jordan 《Clinical anatomy (New York, N.Y.)》2017,30(3):303-311
Gross anatomy is considered one of the most important basic science courses in medical education, yet few medical schools require its completion prior to matriculation. The effect of taking anatomy courses before entering medical school on performance in medical gross anatomy has been previously studied with inconsistent results. The effect of premedical anatomy coursework on performance in medical gross anatomy, overall medical school grade point average (GPA), and Comprehensive Osteopathic Medical Licensing Examination Level 1 (COMLEX 1) score was evaluated in 456 first‐year osteopathic medical students along with a survey on its perceived benefits on success in medical gross anatomy course. No significant differences were found in gross anatomy grade, GPA, or COMLEX 1 score between students with premedical anatomy coursework and those without. However, significant differences and higher scores were observed in students who had taken three or more undergraduate anatomy courses including at least one with cadaveric laboratory. There was significantly lower perceived benefit for academic success in the medical gross anatomy course (P<.001) from those students who had taken premedical anatomy courses (5.9 of 10) compared with those who had not (8.2 of 10). Results suggest that requiring any anatomy course as a prerequisite for medical school would not have significant effect on student performance in the medical gross anatomy course. However, requiring more specific anatomy coursework including taking three or more undergraduate anatomy courses, one with cadaveric laboratory component, may result in higher medical gross anatomy grades, medical school GPA, and COMLEX 1 scores. Clin. Anat. 30:303–311, 2017. © 2017 Wiley Periodicals, Inc. 相似文献
96.
Wood HG Anderson J Allaire PE McDaniel JC Bearnson G 《The International journal of artificial organs》1999,22(12):827-836
A very small centrifugal pump, fully supported by magnetic bearings, is being developed for use as a ventricular assist device to be implanted in humans. In this paper, we apply computational fluid dynamics to model the blood flow to aid in the design of the ventricular assist device. The flow of blood through the pump has been modeled using computational fluid dynamics (CFD) software that is commercially available from AEA Technology, UK. The flow regions modeled in version 3 of the Continuous Flow Ventricular Assist Device (CF3) are the fully shrouded four bladed impeller and the two clearance regions around the impeller that are bounded by the pump hub and shroud. This paper describes the geometry and computational grids developed for the flow regions, and the equations of motion for the blood flow are developed. The overall numerically-evaluated flow rates and head rise have similar trends to the flow parameters experimentally measured, indicating that future pump designs can be effectively modeled numerically before being constructed and tested. Numerical solutions are presented and compared with experimentally-obtained overall pump performance results. These solutions are used to predict shear stress levels to be experienced by the blood flowing through the pump, and it is predicted that hemolysis will be insignificant. The solutions also indicate no regions of flow stagnation that can be a source of thrombosis in pumps. The calculations provide a viable design method to achieve improved efficiency in future versions of this pump. 相似文献
97.
BO Motayo PA Akinduti FA Adeyakinu PO Okerentugba JC Nwanze CC Onoh HC Innocent-Adiele IO Okonko 《African health sciences》2013,13(4):1091-1097
Background
The increased reports of ESBL dissemination from various centres in south western, Nigeria and the recent emergence of carbapenem resistant bacteria prompted the conception of this study.Objectives
To demonstrate the relationship between high molecular weight plasmids and the expression of antibiotic multi-resistance including ESBL and carbapenemase.Methods
We investigated 97 isolates of selected organisms consisting of 67 E. coli and 30 Klebseilla spp for the presence of plasmids expressing ESBL including carbapenem-hydrolysing enzymes. Beta-lactamase was determined using acidometric method, while ESBL and carbapenemase activity was determined using the double-disk diffusion test as well as the Modified Hodge test (MHT). Plasmid profiles of ESBL and carbapenemase positive isolates were determined according to standard protocols.Results
An ESBL prevalence rate of 21.6% and carbapenem- resistance rate of 9.3% was recorded. Antibiotic susceptibility profile of ESBL isolates showed 100.0% resistance against Amoxicillin, Cotrimoxazole and Erythromycin. Moderate susceptibility was recorded against the Quinolone class of antibiotics; Meropenem remained the most active antibiotic against ESBL isolates with 62.5% against E. coli and 60% against K. pneumoniae. The plasmid profiles of our study isolates ranged from 11.8kbp to 35.5kbp.Conclusion
Due to the relationship between high molecular weight plasmids and multi-drug resistance, we hereby recommend regular molecular surveillance of this form in our study setting. 相似文献98.
The locus of enterocyte effacement (LEE)-encoded regulator controls expression of both LEE- and non-LEE-encoded virulence factors in enteropathogenic and enterohemorrhagic Escherichia coli 总被引:7,自引:0,他引:7 下载免费PDF全文
Elliott SJ Sperandio V Girón JA Shin S Mellies JL Wainwright L Hutcheson SW McDaniel TK Kaper JB 《Infection and immunity》2000,68(11):6115-6126
Regulation of virulence gene expression in enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC) is incompletely understood. In EPEC, the plasmid-encoded regulator Per is required for maximal expression of proteins encoded on the locus of enterocyte effacement (LEE), and a LEE-encoded regulator (Ler) is part of the Per-mediated regulatory cascade upregulating the LEE2, LEE3, and LEE4 promoters. We now report that Ler is essential for the expression of multiple LEE-located genes in both EPEC and EHEC, including those encoding the type III secretion pathway, the secreted Esp proteins, Tir, and intimin. Ler is therefore central to the process of attaching and effacing (AE) lesion formation. Ler also regulates the expression of LEE-located genes not required for AE-lesion formation, including rorf2, orf10, rorf10, orf19, and espF, indicating that Ler regulates additional virulence properties. In addition, Ler regulates the expression of proteins encoded outside the LEE that are not essential for AE lesion formation, including TagA in EHEC and EspC in EPEC. delta ler mutants of both EPEC and EHEC show altered adherence to epithelial cells and express novel fimbriae. Ler is therefore a global regulator of virulence gene expression in EPEC and EHEC. 相似文献
99.
Oscar Bernal‐Pacheco MD Genko Oyama MD PhD Kelly D. Foote MD Yunfeng E. Dai MS Samuel S. Wu PhD Charles E. Jacobson IV BS Natlada Limotai MD Pamela R. Zeilman ARNP Janet Romrell PA Nelson Hwynn DO Ramon L. Rodriguez MD Irene A. Malaty MD Michael S. Okun MD 《Neuromodulation》2013,16(1):35-40
Objectives: To screen for potentially underreported behavioral changes in patients with idiopathic Parkinson's disease (PD) pre‐ and post‐deep brain stimulation (DBS), a retrospective data base review was performed. Methods: In total, 113 patients who underwent unilateral or bilateral DBS at the University of Florida in either subthalamic nucleus or globus pallidus internus for PD were screened for behavioral issues by asking about the presence or absence of seven neuropsychiatric symptoms (panic, fear, paranoia, anger, suicidal flashes, crying, and laughing). Results: There was a high prevalence of fear (16.3%), panic (14.0%), and anger (11.6%) at baseline in this cohort. In the first six months following DBS implantation, anger (32.6%), fear (26.7%), and uncontrollable crying (26.7%) were the most frequent symptoms reported. Those symptoms also were present following six months of DBS surgery (30.2%, 29.1%, and 19.8%, respectively). New uncontrollable crying occurred more in the acute postoperative stage (less than or equal to six months) (p= 0.033), while new anger occurred more in the chronic postoperative stage (greater than six months) (p= 0.017). The frequency of uncontrollable laughing significantly increased with bilateral DBS (p= 0.033). Conclusions: Many of the neuropsychiatric issues were identified at preoperative baseline and their overall occurrence was more than expected. There was a potential for worsening of these issues post‐DBS. There were subtle differences in time course, and in unilateral vs. bilateral implantations. Clinicians should be aware of these potential behavioral issues that may emerge following DBS therapy, and should consider including screening questions in preoperative and postoperative interviews. Standardized scales may miss the presence or absence of these clinically relevant issues. 相似文献
100.
Arthrograms of the temporomandibular joint were obtained in 20 symptomatic joints that had previous reconstructive arthroplasty with disk repositioning because of internal derangements. Preoperative arthrograms were available for comparison in 18 joints. Symptoms resulting in a postoperative arthrogram included pain, limited ability to open the mouth, and clicking of the joints. Postoperative arthrographic findings included limited anterior translation of the condyle (90%), irregularity in outline of the intraarticular contrast agent (60%), a conical configuration of the posterior recess (25%), decreased size of the joint (28%), anterior displacement of the meniscus (25%), and perforated meniscus (15%). Many of these findings may have resulted from fibrosis and scarring, which may be a response to intraarticular bleeding. The mechanism by which the fibrosis causes the postsurgical arthrographic features is discussed. 相似文献