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排序方式: 共有188条查询结果,搜索用时 15 毫秒
1.
Identification of a gene disrupted by a microdeletion in a patient with X-linked retinitis pigmentosa (XLRP) 总被引:2,自引:2,他引:2
Roepman R; Bauer D; Rosenberg T; van Duijnhoven G; van de Vosse E; Platzer M; Rosenthal A; Ropers HH; Cremers FP; Berger W 《Human molecular genetics》1996,5(6):827-833
The gene for the most frequent from of X-linked retinitis pigmentosa
(XLRP), RP3, has been assigned by genetic and physical mapping to a segment
of less than 1000 kbp, which is flanked by the marker DXS1110 and the
ornithine transcarbamylase (OTC) gene. In search of microdeletions, we have
screened the DNA of 30 unrelated patients with XLRP by employing a
representative set of YAC-derived DNA fragments that were generated by
restriction enzyme digestion and PCR amplification. In one of these
patients, a 6.4 kbp microdeletion was detected which was not present in the
DNA of 444 male controls. A cosmid contig spanning the deletion was
constructed and used to isolate cDNAs from retina-specific libraries. Exons
corresponding to these expressed sequences as well as other putative exons
were identified by sequencing more than 30 kbp of the critical region. So
far, no point mutations in these putative exon sequences have been
identified.
相似文献
2.
Positional cloning of the gene for X-linked retinitis pigmentosa 3: homology with the guanine-nucleotide-exchange factor RCC1 总被引:6,自引:7,他引:6
Roepman R; van Duijnhoven G; Rosenberg T; Pinckers AJ; Bleeker-Wagemakers LM; Bergen AA; Post J; Beck A; Reinhardt R; Ropers HH; Cremers FP; Berger W 《Human molecular genetics》1996,5(7):1035-1041
The gene for retinitis pigmentosa 3 (RP3), the most frequent form of X-
linked RP (XLRP), has been mapped previously to a chromosome interval of
less than 1000 kbp between the DXS1110 marker and the OTC locus at
Xp21.1-p11.4. Employing a novel technique, YAC Representation Hybridization
(YRH)', we have recently identified a small XLRP associated microdeletion
in this interval, as well as several putative exons including the 3' end of
a gene that was truncated by the deletion. cDNA library screening and
sequencing of a cosmid centromeric to the deletion has now enabled us to
identify numerous additional exons and to detect several point mutations in
patients with XLRP. The predicted gene product shows homology to RCC1, the
guanine-nucleotide- exchange factor (GEF) of the Ras-like GTPase Ran. Our
findings suggest that we have cloned the long-sought RP3 gene, and that it
may encode the GEF of a retina-specific GTP-binding protein.
相似文献
3.
Comprehensive mutational scanning of the p53 coding region by two- dimensional gene scanning 总被引:2,自引:0,他引:2
A comprehensive mutational scanning test for the p53 coding region based on
multiplex PCR and two-dimensional DNA electrophoresis was designed and
evaluated. In a 2-step multiplex PCR, the p53 coding region (exons 2-11)
was amplified as a single 8646-bp fragment by long- distance PCR in step
one. This fragment served as a template for the subsequent co-amplification
of the individual exons in two multiplex groups in step two. The multiplex
products were then separated, first on the basis of size in non-denaturant
polyacrylamide gels and then on the basis of sequence by denaturing
gradient gel electrophoresis (DGGE). Primers for optimal PCR, melting
behavior and 2-D gel distribution were designed using a recently developed
computer program. The resulting two-dimensional gene scanning (TDGS) test
was evaluated by screening, in a blinded fashion, 29 coded DNA samples from
Li- Fraumeni syndrome patients with previously identified germline
mutations. All mutations were correctly detected. This assay provides an
accurate, cost-effective and non-radioactive method for simultaneous
mutational scanning of all p53 coding exons.
相似文献
4.
Age 65 represents a transition point where most U.S. residents begin Medicare coverage. We examined whether or not delays in medical care near this age extend to cancer diagnosis. We calculated single-year-of-age cancer incidence rates by site and stage for the most common cancer sites (i.e., prostate, female breast, lung, and colorectal) for the 2000–2010 period using data from the SEER 18 registries, and we used Poisson regression to identify a possible age-65 effect. The analysis was repeated on comparable Canadian data. Cancer rates at age 65 were found to be as much as 15% above expected in the U.S. data, with the age-65 effect strongly associated with site- and stage-specific survival. A smaller association was seen in the Canadian data. We found strong evidence that diagnosis of less severe cancers spikes at age 65. Delay of medical care prior to this age has complex policy implications.The 65th birthday is a major life milestone for many Americans. It corresponds to the age when nearly all become eligible for health-care coverage through Medicare, when many begin receiving Social Security benefits, and when many choose to retire. This age boundary has been shown to have profound effects on health and health-care utilization. For example, rates of medical screening, diagnosis, and treatment for conditions that are low urgency, asymptomatic, and reimbursable by Medicare are found at much higher levels among those aged 65 years than those aged 64 years.1–3 It has been suggested that this phenomenon is driven by the low-cost “Welcome to Medicare” physical examination instituted in 2005, but too few people have taken advantage of this feature for it to explain much of the difference.4In contrast, rates of “nondeferrable admissions,” defined as conditions where hospital admission rates through emergency departments do not diminish on weekends, show no change at age 65 years.5 For those who are uninsured or underinsured, there are clear financial incentives to postpone nonurgent medical encounters until Medicare is available. The effect is too large, however, to be explained by the behavior of the uninsured and underinsured alone. Even some people who are fully insured postpone treatment until age 65 years, either because of the perception that Medicare is a more generous health-care plan than other insurance plans or because postponing is more convenient.5 Recovering from a hip replacement while retired, for example, may be more practical than attempting to do so while employed.None of the existing research on pent-up demand for Medicare has, to our knowledge, specifically considered cancer incidence. We hypothesized that cancer should follow the same pattern as seen for other medical conditions. Specifically, screen-detected, asymptomatic, nonlethal tumors should show an unusually high incidence rate at age 65 years relative to other ages, while advanced-stage, low-survival tumors should show no difference. If correct, this observation should inform the current discussion regarding the extent to which certain cancers are being overdiagnosed and overtreated as a consequence of aggressive screening,6 as the Medicare program may be unwittingly bearing an undue share of the cost of such treatment. Conversely, underdiagnosis and undertreatment of those approaching 65 years of age may also be unduly shortening life spans among this group.We measured the elevation in cancer rates at age 65 years above what would be expected based on the otherwise smooth trend between ages 55 and 75 years. We considered prostate, female breast, lung, and colorectal cancers—the four most common cancer sites—which accounted for approximately 54% of all incident cases in the United States during the 2000–2010 period. Each of these cancers is detectable through screening, although at the time of writing only colorectal cancer screening for those aged 50–75 years was unequivocally endorsed by the U.S. Preventive Services Task Force (USPSTF).7 Breast cancer screening for women aged 50–74 years is generally recommended, but the guidelines for women older than 40 years of age are currently under review.8,9 Lung cancer screening is recommended only for current or recent heavy smokers aged 55–80 years,10 and prostate cancer screening is not recommended at all.11 We further investigated the relationship between the age-65 effect and the severity of the cancer, as measured by five-year survival. Finally, we compared the results from the United States with equivalent results from Canada, where no change in health-care insurance status occurs at age 65, but where 65 is also a popular retirement age. 相似文献
5.
FP Robertson D Tsironis BR Davidson 《Annals of the Royal College of Surgeons of England》2015,97(5):e77-e78
Diaphragmatic lesions are usually congenital bronchogenic cysts. A patient with a known diaphragmatic cyst presented with new onset right upper quadrant pain. Repeat imaging showed enlargement of the cyst, the CA19–9 cancer marker was raised at 312iu/ml (normal: <27iu/ml) and positron emission tomography combined with computed tomography showed focally increased uptake in the cystic wall. In view of symptoms and risk of neoplasia, the lesion was excised. Histology showed a benign epidermoid cyst. Features falsely suggesting neoplasia have been reported previously with benign splenic cysts but not with a benign diaphragmatic epidermoid cyst. 相似文献
6.
7.
Philip J Warelow B Nurs M Nurs S RPN RCN FP Cert AFP Cert 《Journal of advanced nursing》1996,24(4):655-661
This paper will examine the claim that caring is an appropriate ethical ideal for nursing. Initially it will examine nursing's philosophy of care and caring, highlighting some areas of difficulty and dissatisfaction articulated by many of its contemporary theorists Evaluation of the notion of caring as an appropriate ethical ideal for nursing will be balanced against those in opposition, and in this process their critique will be discussed This discussion will focus on areas such as virtue, virtue ethics, moral responsibility, feminine values, mothering and the debate between male and female caring Different forms of caring will be evaluated and balanced against different forms of nursing The paper will then suggest that current views which hold aloft nursing as a bedmate of caring may be detrimental to both the cared-for and the carer, advocating in the process a move toward change 相似文献
8.
9.
The biological and biochemical effects of CP-654577, a selective erbB2 kinase inhibitor,on human breast cancer cells 总被引:3,自引:0,他引:3
Barbacci EG Pustilnik LR Rossi AM Emerson E Miller PE Boscoe BP Cox ED Iwata KK Jani JP Provoncha K Kath JC Liu Z Moyer JD 《Cancer research》2003,63(15):4450-4459
Aberrant expression or activity of epidermal growth factor receptor (EGFr) or the closely related p185(erbB2) can promote cell proliferation and survival and thereby contribute to tumorigenesis. Specific antibodies and low molecular-weight tyrosine kinase inhibitors of both proteins are in clinical trials for cancer treatment. CP-654577 is a potent inhibitor selective for p185(erbB2), relative to EGFr tyrosine kinase, and selectively reduces erbB2 autophosphorylation in intact cells. Treatment of SKBr3 human breast cancer cells with CP-654577 reduces the levels of the activated form of mitogen-activated protein kinase, increases the levels of cyclin-dependent kinase inhibitor p27(kip1) and reduces expression of cyclins D and E. These biochemical changes result in a reduced level of phosphorylated retinoblastoma protein and an inhibition of cell-cycle progression at G(1). Apoptosis is triggered in both SKBr3 and another high erbB2-expressing cell line, BT474, by exposure to 1 micro M CP-654577, but this effect is not observed in MCF7 cells that express low erbB2. Levels of activated Akt, an important positive regulator of cell survival, are reduced within 2 h of exposure to 250 nM CP-654577, and this may contribute to the increased apoptosis. These biochemical effects are distinct from those produced by Tarceva, a selective EGFr inhibitor. The antitumor activity of CP-654577 was investigated in athymic mice bearing s.c. tumors from Fischer rat embryo fibroblasts transfected with erbB2. CP-654577 produced a dose-dependent reduction of p185(erbB2) autophosphorylation and inhibited the growth of these tumors. CP-654577 warrants further evaluation in tumors with high expression of p185(erbB2) and may differ from selective EGFr inhibitors or nonselective dual EGFr/erbB2 inhibitors in efficacy and therapeutic index. 相似文献
10.
In an earlier article in this journal (June 1999) we discussed the risk that the presence of cardiac disease poses to patients undergoing non-cardiac surgery. We outlined factors in the patient's medical history, examination findings and the value of various tests in arriving at an overall assessment of risk for any given patient. In this article we concentrate on the management of these patients as they undergo surgery itself. We shall consider what measures may usefully be employed in order to minimise the risk of an adverse cardiac event occurring in the perioperative period. 相似文献