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91.
Champion KJ, Bunag C, Estep AL, Jones JR, Bolt CH, Rogers RC, Rauen KA, Everman DB. Germline mutation in BRAF codon 600 is compatible with human development: de novo p.V600G mutation identified in a patient with CFC syndrome. BRAF, the protein product of BRAF, is a serine/threonine protein kinase and one of the direct downstream effectors of Ras. Somatic mutations in BRAF occur in numerous human cancers, whereas germline BRAF mutations cause cardio‐facio‐cutaneous (CFC) syndrome. One recurrent somatic mutation, p.V600E, is frequently found in several tumor types, such as melanoma, papillary thyroid carcinoma, colon cancer, and ovarian cancer. However, a germline mutation affecting codon 600 has never been described. Here, we present a patient with CFC syndrome and a de novo germline mutation involving codon 600 of BRAF, thus providing the first evidence that a pathogenic germline mutation involving this critical codon is not only compatible with development but can also cause the CFC phenotype. In vitro functional analysis shows that this mutation, which replaces a valine with a glycine at codon 600 (p.V600G), leads to increased ERK and ELK phosphorylation compared to wild‐type BRAF but is less strongly activating than the cancer‐associated p.V600E mutation.  相似文献   
92.
As the number of people living with chronic illness in the United States rises, it is imperative that medical school prepare physicians who are capable of caring for these patients. This article outlines a creative educational intervention to teach third‐ and fourth‐year medical students about caring for chronically ill people. All students at Weill Medical College, Cornell University, make home visits to homebound older adults with an interdisciplinary team as part of a mandatory Primary Care Clerkship. Under their guidance, students observe the myriad challenges facing homebound older adults. Afterward, students create a project, using original or found art, to express their reactions and thoughts. Students present projects to peers in a small group, with multidisciplinary faculty mentors framing the discussion. To evaluate the intervention, students responded to a nine‐item questionnaire and a series of open‐ended questions. Quantitative and qualitative analyses show consistently strong positive responses to the experience. Most students (95.0%) felt that they learned about the complexities of chronic illness care from their home visits. The opportunity to express reactions through a creative project received positive responses with 97.0% of students responding favorably. Ninety‐seven percent felt that the discussions with colleagues and faculty increased knowledge of chronic illness care. Nearly all (97.0%) felt they had a better understanding of team and that attitudes toward the chronically ill were positively affected. The coupling of the creative arts with home visits is an effective tool for teaching about chronic illness and may be a useful model for medical schools interested in expanding their chronic illness curriculum.  相似文献   
93.
Various biomaterial scaffolds have been investigated for cartilage tissue engineering, although little attention has been paid to the effect of scaffold microstructure on tissue growth. Non-woven, fibrous, bioabsorbable scaffolds constructed from a copolymer of glycolide and trimethylene carbonate with varying levels of porosity and pore size were seeded with mesenchymal stroma cells with a chondrogenic lineage. Scaffolds and media were evaluated for both cell and extracellular matrix organization and content after up to 28 days of culture in a spinner flask. Analysis of DNA and glycosaminoglycan contents showed that the most porous of the three scaffold types, with a porosity of 81% and a porometry determined mean flow pore diameter of 54 microm, supported the most rapid proliferation of cells and accumulation of extracellular matrix. Analysis of the high porosity scaffold system, using Western Blot and immunohistochemistry confirmed the presence of collagen type II and absence of collagen type I, and demonstrated cells with a chondrocyte morphology with aggrecan and collagen II accumulation attached to the scaffolds. It was concluded that the 3D-microstructural characteristics of the scaffold (interconnecting porosity and pore size) play an important role in proliferation and phenotype of chondrogenic cells and accumulation of extracellular matrix molecules.  相似文献   
94.
In previous studies on the colony phenotype switching of Saccharomyces cerevisiae, we observed that the least virulent isolates formed greater numbers of petite colonies when grown at body temperature, 37 degrees C. To determine if there is a link between virulence and petite formation, we examined the frequency of spontaneous petite formation for virulent clinical isolates (YJM128, YJM309), an intermediate virulent segregant of YJM128 (YJM145) and avirulent clinical (YJM308) and nonclinical S. cerevisiae (Y55, YJM237) after growth at 37 degrees C. The rank order of increasing frequency of petite formation was YJM128 = YJM145 < YJM309 < Y 55 < YJM308 = YJM237, which is similar to the rank-order of virulence in CD-1 mice. To assess the virulence of petites in vivo, two mouse models, CD-1 and DBA/ 2N, were infected i.v. with 10(7) cfu of either the parental grand or a spontaneously derived petite from one of four isolates previously classified with differing degrees of virulence: YJM128, YJM309, YJM145 and Y55. In both CD-1 and DBA/2N, the mean log10 cfu of grands recovered from the brain was significantly higher than that of the petites (P<0001). Overall, petites were significantly less virulent than the parental strains. However, death of some DBA/2N mice caused by YJM128 petite 1 showed that petites are not totally avirulent. To see if S. cerevisiae isolates form petite colonies in vivo, both mouse models were infected with parental grands of YJM128 and Y55. Recovered colonies were counted and confirmed as grand or petite, and the frequency of petite colonies in the brain, the target organ, correlated with the in vitro results. Overall, these studies show an inverse correlation between the frequency of petite-colony formation and the previously determined virulence of S. cerevisiae in CD-1 mice. Furthermore, petites were significantly less virulent than the parental grands, in most cases, and petites are spontaneously formed in vivo at a frequency inversely correlated to the virulence of the strain.  相似文献   
95.

Background

The burden of lymphomas on the health care system in Nigeria is enormous. Correct diagnosis and identification of aetiological factor are important steps in reducing this burden.

Methods

Eight cases diagnosed as HL within a period of six years at the Obafemi Awolowo University teaching Hospital, Ile-Ife, Nigeria by haematoxylin and eosin (Hand E) only were immunophenotyped using the indirect immunoperoxidase method. Epstein-Barr virus latent membrane protein-1 (LMP-1), CD15 and CD30 immunohistochemistry was also performed. The clinical characteristics of each patient were documented.

Objectives

To document the frequency of involvement of Epstein-Barr virus in cases of HL seen in a university hospital in Nigeria.

Results

Out of the eight cases diagnosed by H&E as HL immunophenotyping showed only five were HL. The rest were non-Hodgkin''s lymphoma (2 diffuse large B-cell and 1 null cell ALCL). All were cases of classical HL with 60% being of the mixed cellularity (MC) subtype. There were 2 males and 3 females with ages ranging from 7 years to 40 years. All presented with cervical lymphadenopathy and three had splenomegaly in addition. 60% of the tumour was EBV positive, all of the MC subtype. Three patients had chemotherapy. Eventually all were lost to follow-up. There was no case of the nodular lymphocyte predominance variant.

Conclusion

Mixed cellularity is the most common subtype and is the only subtype associated with EBV positivity in this study. Epstein-Barr virus probably plays an important role in the aetiology of HL in Nigerians.Running title: Epstein-Barr virus, Hodgkin''s lymphoma in Nigerians  相似文献   
96.
To determine the phenotype and natural history of a founder genetic subtype of autosomal dominant arrhythmogenic right ventricular cardiomyopathy (ARVC) caused by a p.S358L mutation in TMEM43. The age of onset of cardiac symptoms, clinical events and test abnormalities were studied in 412 subjects (258 affected and 154 unaffected), all of which occurred in affected males significantly earlier and more often than unaffected males. Affected males were hospitalized four times more often than affected females (p ≤ 0.0001) and died younger (p ≤ 0.001). The temporal sequence from symptoms onset to death was prolonged in affected females by 1–2 decades. The most prevalent electrocardiogram (ECG) manifestation was poor R wave progression (PRWP), with affected males twice as likely to develop PRWP as affected females (p ≤ 0.05). Left ventricular enlargement (LVE) occurred in 43% of affected subjects, with 11% fulfilling criteria for dilated cardiomyopathy. Ventricular ectopy on Holter monitor was common and occurred early: the most diagnostically useful clinical test. No symptom or test could rule out diagnosis. This ARVC subtype is a sex‐influenced lethal arrhythmogenic cardiomyopathy, with a unique ECG finding, LV dilatation, heart failure and early death, where molecular pre‐symptomatic diagnosis has the greatest clinical utility.  相似文献   
97.
A novel system to study the effects of co-cross-linking CD23/FceRII and sIg on murine B lymphocytes utilizes a highly multivalent form of anti- Ig prepared by covalently linking anti-Ig antibodies to a DNP-dextran backbone. CD23-sIg co-cross-linking is accomplished by the addition of DNP-specific monoclonal IgE. Previous studies demonstrated that co- cross-linking CD23 and sIg significantly inhibited mouse B cell proliferation, especially at high doses of the multivalent anti-Ig. Interestingly, examination of early activation signals reveals no difference in B cells subjected to co-cross-linking conditions as compared to B cells activated with anti-Ig alone. Total cellular protein tyrosine phosphorylation levels are unchanged by co-cross- linking. Analysis of B cell mRNA reveals that co-cross-linking the receptors does not alter the expression levels of ornithine decarboxylase 8 h after stimulation as compared to the controls. In contrast, levels of the proto-oncogene c-myc were significantly elevated 1 h after inducing B cell activation under co-cross-linking conditions. However, it remains unclear whether this aberrant c-myc regulation plays any role in inducing apoptosis. In addition, on day 3 after stimulation, the co-cross-linking of CD23 and sIg resulted in the formation of apoptotic B cells, determined by both photomicroscopy of the B cell cultures and FACS analysis of B cell nuclei. B cells obtained from bcl-2 transgenic mice proliferated as well as controls, and failed to undergo apoptosis when CD23 and sIg were co-cross-linked on their surface. These studies indicate that co-cross-linking of CD23 with B cell sIg inhibits B cell proliferation by a mechanism that is distinct from that seen by co-cross-linking of the Fc gamma RII and sIg. In addition, these results suggest a means by which antigen- specific IgE can down-regulate additional B cell activation and IgE synthesis.   相似文献   
98.
99.
Summary: Much remains to be learned about the pathogenesis of the different manifestations of dengue virus (DENV) infections in humans. They may range from subclinical infection to dengue fever, dengue hemorrhagic fever (DHF), and eventually dengue shock syndrome (DSS). As both cell tropism and tissue tropism of DENV are considered major determinants in the pathogenesis of dengue, there is a critical need for adequate tropism assays, animal models, and human autopsy data. More than 50 years of research on dengue has resulted in a host of literature, which strongly suggests that the pathogenesis of DHF and DSS involves viral virulence factors and detrimental host responses, collectively resulting in abnormal hemostasis and increased vascular permeability. Differential targeting of specific vascular beds is likely to trigger the localized vascular hyperpermeability underlying DSS. A personalized approach to the study of pathogenesis will elucidate the basis of individual risk for development of DHF and DSS as well as identify the genetic and environmental bases for differences in risk for development of severe disease.  相似文献   
100.

Background

On more and more websites, consumers are provided with public reports about health care. This move toward provision of more comparative information has resulted in different information types being published that often contain contradictory information.

Objective

The objective was to assess the current state of the art in the presentation of online comparative health care information and to compare how the integration of different information types is dealt with on websites. The content analysis was performed in order to provide website managers and Internet researchers with a resource of knowledge about presentation formats being applied internationally.

Methods

A Web search was used to identify websites that contained comparative health care information. The websites were systematically examined to assess how three different types of information (provider characteristics and services, performance indicators, and health care user experience) were presented to consumers. Furthermore, a short survey was disseminated to the reviewed websites to assess how the presentation formats were selected.

Results

We reviewed 42 websites from the following countries: Australia, Canada, Denmark, Germany, Ireland, the Netherlands, Norway, the United Kingdom, the United States, and Sweden. We found the most common ways to integrate different information types were the two extreme options: no integration at all (on 36% of the websites) and high levels of integration in single tables on 41% of the websites). Nearly 70% of the websites offered drill down paths to more detailed information. Diverse presentation approaches were used to display comparative health care information on the Internet. Numbers were used on the majority of websites (88%) to display comparative information.

Conclusions

Currently, approaches to the presentation of comparative health care information do not seem to be systematically selected. It seems important, however, that website managers become aware of the complexities inherent in comparative information when they release information on the Web. Important complexities to pay attention to are the use of numbers, the display of contradictory information, and the extent of variation among attributes and attribute levels. As for the integration of different information types, it remains unclear which presentation approaches are preferable. Our study provides a good starting point for Internet research to further address the question of how different types of information can be more effectively presented to consumers.  相似文献   
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