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43.
Analysis of myocilin mutations in 1703 glaucoma patients from five different populations 总被引:21,自引:0,他引:21
Fingert JH Héon E Liebmann JM Yamamoto T Craig JE Rait J Kawase K Hoh ST Buys YM Dickinson J Hockey RR Williams-Lyn D Trope G Kitazawa Y Ritch R Mackey DA Alward WL Sheffield VC Stone EM 《Human molecular genetics》1999,8(5):899-905
A glaucoma locus, GLC1A, was identified previously on chromosome 1q. A gene within this locus (encoding the protein myocilin) subsequently was shown to harbor mutations in 2-4% of primary open angle glaucoma patients. A total of 1703 patients was screened from five different populations representing three racial groups. There were 1284 patients from primarily Caucasian populations in Iowa (727), Australia (390) and Canada (167). A group of 312 African American patients was from New York City and 107 Asian patients from Japan. Overall, 61 different myocilin sequence variations were identified. Of the 61 variations, 21 were judged to be probable disease-causing mutations. The number of probands found to harbor such mutations in each population was: Iowa 31/727 (4.3%), African Americans from New York City 8/312 (2.6%), Japan 3/107 (2.8%), Canada 5/167 (3.0%), Australia 11/390 (2.8%) and overall 58/1703 (3. 4%). Overall, 16 (76%) of 21 mutations were found in only one population. The most common mutation observed, Gln368Stop, was found in 27/1703 (1.6%) glaucoma probands and was found at least once in all groups except the Japanese. Studies of genetic markers flanking the myocilin gene suggest that most cases of the Gln368Stop mutations are descended from a common founder. Although the specific mutations found in each of the five populations were different, the overall frequency of myocilin mutations was similar ( approximately 2-4%) in all populations, suggesting that the increased rate of glaucoma in African Americans is not due to a higher prevalence of myocilin mutations. 相似文献
44.
KM Kanal NJ Hangiandreou AM Sykes HE Eklund PA Araoz JA Leon BJ Erickson 《Journal of digital imaging》2002,14(1):30-37
The aims of this work were to measure the accuracy of one continuous speech recognition product and dependence on the speaker's
gender and status as a native or nonnative English speaker, and evaluate the product's potential for routine use in transcribing
radiology reports. IBM MedSpeak/Radiology software, version 1.1 was evaluated by 6 speakers. Two were nonnative English speakers,
and 3 were men. Each speaker dictated a set of 12 reports. The reports included neurologic and body imaging examinations performed
with 6 different modalities. The dictated and original report texts were compared, and error rates for overall, significant,
and subtle significant errors were computed. Error rate dependence on modality, native English speaker status, and gender
were evaluated by performing ttests. The overall error rate was 10.3 +/- 3.3%. No difference in accuracy between men and women
was found; however, significant differences were seen for overall and significant errors when comparing native and nonnative
English speakers (P = .009 and P = .008, respectively). The speech recognition software is approximately 90% accurate, and
while practical implementation issues (rather than accuracy) currently limit routine use of this product throughout a radiology
practice, application in niche areas such as the emergency room currently is being pursued. This methodology provides a convenient
way to compare the initial accuracy of different speech recognition products, and changes in accuracy over time, in a detailed
and sensitive manner. 相似文献
45.
Sheffield MV Simsir A Talley L Roberson AJ Elgert PA Chhieng DC 《American journal of clinical pathology》2003,119(3):367-373
We compared the interobserver reproducibility of estimating the adequacy of the squamous component of conventional Papanicolaou (Pap) smears using traditional and newly proposed criteria. Forty conventional Pap smears with varying degrees of squamous cellularity were reviewed by 13 observers who evaluated adequacy (satisfactory vs unsatisfactory) based on the traditional criterion of estimating 10% slide coverage. After being introduced to the new criterion and the reference images, the observers reevaluated adequacy on the same set of smears, using the new criterion and the reference images. With the original criterion of 10% slide coverage, 15 smears had a unanimous designation; the overall kappa value was 0.49 (P < .001). With the newly proposed adequacy criterion and reference images, 17 smears had a unanimous designation; the overall kappa value was 0.60 (P < .001). The difference in the kappa correlation coefficients was statistically significant (P = .007). While traditional and newly proposed criteria resulted in fair interobserver agreement, it seemed that the newly proposed criterion, along with the use of reference images, for evaluating adequacy of the squamous component of conventional Pap smears results in better interobserver reproducibility. 相似文献
46.
Canfield MC; Tamarappoo BK; Moses AM; Verkman AS; Holtzman EJ 《Human molecular genetics》1997,6(11):1865-1871
Congenital nephrogenic diabetes insipidus (NDI) is a rare disease caused
most often by mutations in the vasopressin V2 receptor (AVPR2). We studied
a family which included a female patient with NDI with symptoms dating from
infancy. The patient responded to large doses of desmopressin (dDAVP) which
decreased urine volume from 10 to 4 I/day. Neither the parents nor the
three sisters were polyuric. The patient was found to be a compound
heterozygote for two novel recessive point mutations in the aquaporin-2
(AQP2) gene: L22V in exon 1 and C181W in exon 3. Residue Cys181 in AQP2 is
the site for inhibition of water permeation by mercurial compounds and is
located near to the NPA motif conserved in all aquaporins. Osmotic water
permeability (Pf) in Xenopus oocytes injected with cRNA encoding C181W-AQP2
was not increased over water control, while expression of L22V cRNA
increased the Pf to approximately 60% of that for wild-type AQP2.
Co-injection of the mutant cRNAs with the wild-type cRNA did not affect the
function of the wild-type AQP2. Immunolocalization of AQP2-transfected CHO
cells showed that the C181W mutant had an endoplasmic reticulum-like
intracellular distribution, whereas L22V and wild-type AQP2 showed endosome
and plasma membrane staining. Water permeability assays showed a high Pf in
cells expressing wild-type and L22V AQP2. This study indicates that AQP2
mutations can confer partially responsive NDI.
相似文献
47.
Jacobson SG Sumaroka A Aleman TS Cideciyan AV Schwartz SB Roman AJ McInnes RR Sheffield VC Stone EM Swaroop A Wright AF 《Human molecular genetics》2004,13(17):1893-1902
Mutations in the nuclear receptor gene, NR2E3, cause a disorder of human retinal photoreceptor development characterized by hyperfunction and excess of the minority S (short wavelength or blue) cone photoreceptor type, but near absence of function of the majority rod receptor. NR2E3 disease can also progress to blindness. How the human retina accommodates mis-specified types and numbers of neurons and advances to retinal degeneration are unknown. We studied the retinal organization in vivo of patients with NR2E3 mutations. Early human NR2E3 disease with S cone hyperfunction showed thickened retinal layers within an otherwise normally structured retina. With visual loss, however, lamination was coarse and there was a strikingly thick and bulging appearance to the retina, localized to an annulus encircling the central fovea. This pattern was not found in other retinal degenerations. The abnormal laminar retinal architecture of early NR2E3 disease may be due in part to larger cells with an S cone phenotype in place of rods that failed to differentiate. The later-stage dysplastic appearance suggests a previously unrecognized proliferative response in human retinal degeneration. 相似文献
48.
Debelenko LV; Brambilla E; Agarwal SK; Swalwell JI; Kester MB; Lubensky IA; Zhuang Z; Guru SC; Manickam P; Olufemi SE; Chandrasekharappa SC; Crabtree JS; Kim YS; Heppner C; Burns AL; Spiegel AM; Marx SJ; Liotta LA; Collins FS; Travis WD; Emmert-Buck MR 《Human molecular genetics》1997,6(13):2285-2290
Lung carcinoids occur sporadically and rarely in association with multiple
endocrine neoplasia type 1 (MEN1). There are no well defined genetic
abnormalities known to occur in these tumors. We studied 11 sporadic lung
carcinoids for loss of heterozygosity (LOH) at the locus of the MEN1 gene
on chromosome 11q13, and for mutations of the MEN1 gene using dideoxy
fingerprinting. Additionally, a lung carcinoid from a MEN1 patient was
studied. In four of 11 (36%) sporadic tumors, both copies of the MEN1 gene
were inactivated. All four tumors showed the presence of a MEN1 gene
mutation and loss of the other allele. Observed mutations included a 1 bp
insertion, a 1 bp deletion, a 13 bp deletion and a single nucleotide
substitution affecting a donor splice site. Each mutation predicts
truncation or potentially complete loss of menin. The remaining seven
tumors showed neither the presence of a MEN1 gene mutation nor 11q13 LOH.
The tumor from the MEN1 patient showed LOH at chromosome 11q13 and a
complex germline MEN1 gene mutation. The data implicate the MEN1 gene in
the pathogenesis of sporadic lung carcinoids, representing the first
defined genetic alteration in these tumors.
相似文献
49.
Maša Davidović Nadine Zielonke Iris Lansdorp-Vogelaar Nereo Segnan Harry J. de Koning Eveline AM. Heijnsdijk 《Value in health》2021,24(3):353-360
ObjectivesTo quantify the impact of mammography-based screening on the quality of life, disability-adjusted life years (DALYs) averted or quality-adjusted life years (QALYs) gained can be used. We aimed to assess whether the use of DALYs averted or QALYs gained will lead to different cost-effective screening strategies.MethodsUsing the microsimulation model MISCAN, we simulated different breast cancer screening strategies varying in starting age (starting at 45, 47, and 50 years), stopping age (stopping at 69, 72, and 74 years), and frequency (annual [A], biennial [B], combination of both [A + B], and triennial [T]). In total, we defined 24 different breast cancer screening strategies, including no screening as a reference strategy. We calculated incremental cost-effectiveness ratios (ICERs) and compared which strategies were on the efficiency frontiers for DALYs and QALYs.ResultsBreast cancer screening averted between 46.00 and 105.58 DALYs and gained between 28.69 and 64.50 QALYs per 1000 women. For DALYs there were 5 strategies on the efficiency frontier (T50-69, T50-74, T45-74, B45-74, and A45-74). The same strategies plus one (B45-72) were on the efficiency frontier for QALYs.ConclusionsUsing DALYs averted instead of QALYs gained to assess the effects on quality of life from breast cancer screening in the Dutch population yields differences in ICERs, but almost the same strategies were on the efficiency frontiers. Whether the choice in outcome measure leads to a difference in optimal policy depends on the cost-effectiveness threshold. 相似文献
50.
J. L. McCue M.S. F.R.C.S. J. P. Sheffield M.B. B.S. R. K. S. Phillips M.S. F.R.C.S. 《Diseases of the colon and rectum》1995,38(2):152-158
PURPOSE: Adjuvant radiotherapy is used increasingly in the management of rectal cancer. However, ionizing radiation is mutagenic, and, superimposed on a background of increased cellular proliferation as seen around anastomoses and in colorectal cancer patients, there is the potential for enhanced metachronous cancer risk. METHOD: The influence of preoperative irradiation on both carcinogenesis and cellular proliferation at colonic anastomoses was explored in 180 adult male F344 rats. Orthovoltage x-rays were delivered to the distal descending colon by parallel opposed fields. Ninety rats received 16 Gy in one fraction; the remainder received 36 Gy in two fractions one week apart. In each irradiation group 18 rats either acted as controls or one week after radiotherapy underwent distal colotomy and repair. RESULTS: We found the descending colon susceptible to radiation carcinogenesis; 26 colorectal tumors developed in the low-dose irradiation group and 47 in the highdose group (P=0.0008; Mann-Whitney U test, 16 vs. 36 Gy). Preferential tumor development was seen in the anastomotic region. In those animals that underwent surgery and irradiation, among the low-dose irradiation group only 3 of 72 had tumors within the descending colon compared with 21 of 72 at the anastomotic site (McNemar's test chi-squared=40.9; P<0.001), and in the high-dose irradiation group 5 of 72 had tumors within the descending colon compared with 36 of 72 at the anastomotic site (McNemar's test chi-squared=22.0; P<0.001). Anastomotic crypt cell production rates were increased for at least three months following exposure to irradiation (16 Gy: f=15.1,P<0.005; 32 Gy: f=9.4,P<0.005). CONCLUSIONS: Radiation carcinogenesis is greatly enhanced at colonic anastomoses and may result from altered anastomotic proliferation. This has potentially disturbing implications in view of the increasing use of adjuvant radiotherapy for rectal carcinoma. 相似文献