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151.
Molecular analysis and genetic mapping of the rhodopsin gene in families with autosomal dominant retinitis pigmentosa 总被引:1,自引:0,他引:1
S Bunge H Wedemann D David DJ Terwilliger LI van den Born C Aulehla-Scholz C Samanns M Horn J Ott E Schwinger 《Canadian Metallurgical Quarterly》1993,17(1):230-233
Eighty-eight patients/families with autosomal dominant retinitis pigmentosa (RP) were screened for rhodopsin mutations. Direct sequencing revealed 13 different mutations in a total of 14 (i.e., 16%) unrelated patients. Five of these mutations (T4K, Q28H, R135G, F220C, and C222R) have not been reported so far. In addition, multipoint linkage analysis was performed on two large families with autosomal dominant RP due to rhodopsin mutations by using five DNA probes from 3q21-q24. No tight linkage was found between the rhodopsin locus (RHO) and D3S47 (theta max = 0.08). By six-point analysis, RHO was localized in the region between D3S21 and D3S47, with a maximum lod score of 13.447 directly at D3S20. 相似文献
152.
The paper presents a simple single layer protocol covering the functions of X25 levels 2 and 3. It can be used on synchronous or asynchronous lines, such as employed for normal computer terminals. It requires no special hardware, and can use the standard device driver software supplied by manufacturers. The protocol has been working successfully for over two years, and could be of interest to networking projects with limited resources. 相似文献
153.
Richard W.D. Cox J.R. Jr. Engebretson A.M. Fritts J. Gottlieb B.L. Horn C. 《Selected Areas in Communications, IEEE Journal on》1995,13(5):806-815
The Washington University MultiMedia eXplorer (MMX) is a complete, host-independent multimedia system capable of transmitting and receiving JPEG-compressed video, CD-quality audio, and high-resolution radiographic images over the Washington University broadband ATM network. If the host is equipped with an ATM interface card, normal network traffic can be supported via an ATM extension port on the MMX. The major components of the MMX are an ATMizer and three multimedia channels. The ATMizer implements the host interface, the interface to the ATM network, and the interface to the three multimedia channels. This paper describes the architecture of the MMX, the software used with the system, and two applications that have been developed to demonstrate the capability of broadband ATM networks for multimedia applications 相似文献
154.
155.
A restricted part of the domestic chick forebrain is critically involved in the learning process of imprinting. This region is the intermediate and medial part of the hyperstriatum ventrale (IMHV). The effect on imprinting of local injection of the N-methyl-{d}-aspartate (NMDA) receptor blocker {d}-amino-5-phosphonopentanoic acid ({d}-AP5) into the left IMHV was studied in chicks in which the right IMHV had been lesioned. The left IMHV is essential for imprinting when chicks have been lesioned in this way. Injection of ~0.7 nmol {d}-AP5 into the left IMHV significantly impaired imprinting. Injection of ~0.2 nmol {d}-AP5 into the left IMHV, or of ~0.7 nmol {d}-AP5 into the left hyperstriatum accessorium, was without significant effect on imprinting. These results suggest that NMDA receptors in the left IMHV may play an important part in this learning process. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
156.
PURPOSE: We assessed the influence of the histological response to intravesical bacillus Calmette-Guerin (BCG) and the prevalence of p53 nuclear accumulation on the clinical behavior of patients with carcinoma in situ. MATERIALS AND METHODS: Of 60 patients with Bergquist grade 3 carcinoma in situ 13 had primary and 47 had secondary carcinoma in situ. Patients received 6 weekly instillations and nonresponders received an additional 6 instillations at 2-week intervals. No maintenance was administered. Median followup was 48 months. The p53 nuclear accumulation was detected by immunohistochemical analysis with antibody PAb 1801. RESULTS: The complete histological response rate to BCG therapy was 64%, which decreased to 52% at 4 years. BCG was more effective for treatment of primary than secondary carcinoma in situ (complete response rate 85 versus 57%, respectively). The 45% progression rate was related to the initial histological response occurring in 26% of patients with a complete versus 77% with a partial and no response. Consequently, the progression rate was only 8% for primary versus 57% for secondary carcinoma in situ. Of the patients receiving only 1 course of BCG 40% had progression compared to 62% of those who received 2 courses. Patients in whom both courses failed had a progression rate of 89%. Intravesical BCG converted the p53 nuclear immunoreactivity from positive to negative in 73% of the 26 patients expressing reactivity before treatment, of whom 68% also had a complete response. The progression rate was related to the prevalence of p53 nuclear reactivity after but not before treatment (90% of patients with versus 37% without p53 nuclear accumulation had progression). All 3 complete responders with p53 nuclear reactivity after BCG had progression, which suggests that molecular genetic change may precede histological change. Complete responders without p53 nuclear accumulation after BCG treatment experienced the lowest progression rate (21%). CONCLUSIONS: Our results suggest that patients with a persistent complete histological response and without p53 nuclear accumulation after BCG treatment can be followed conservatively. Cystectomy should be considered in all other patients. 相似文献
157.
AC Kole OE Nieweg HJ Hoekstra JR van Horn HS Koops W Vaalburg 《Canadian Metallurgical Quarterly》1998,39(5):810-815
In our study, we investigate the glucose metabolism of various types of bone lesions with 18F-fluorodeoxyglucose (FDG) PET. METHODS: Twenty-six patients showing clinical and radiographic symptoms of a malignant bone tumor were included. Histological examination after the PET study revealed 19 malignant and 7 benign tumors. PET images were corrected for attenuation. Arterial blood samples were taken to establish the input function. The metabolic rate of glucose consumption (MRglc) was calculated for the whole tumor, for the 10 pixels with maximum activity and for contralateral normal muscle tissue. RESULTS: All lesions were clearly visualized with 18F-FDG PET except for a small infarction of the humerus. All the other lesions had increased glucose metabolism compared to surrounding and contralateral muscle tissue. Both maximum and average MRglc for benign, as well as malignant, lesions were significantly higher than for contralateral normal tissue. The maximum and average MRglc were not higher for malignant as opposed to benign lesions. There was a large overlap between the MRglc of benign and malignant lesions. CONCLUSION: Fluorine-18-FDG PET appears suitable to visualize bone tumors. With the quantification of glucose metabolism, it is not possible to differentiate between benign and malignant bone tumors. There does not seem to be a clear correlation between the MRglc and the biologic aggressiveness of the neoplasms. 相似文献
158.
The stress corrosion cracking (SCC) rate of reactor internals of boiling water reactors (BWR) continues to increase with on-line operating years. The recent occurrences of cracking in the weld heat affected zones of high carbon stainless steel core shrouds correlate with the years of operation and the water chemistry history. Recently, cracking has also been found in shrouds that were constructed of low carbon or stabilized stainless steels. While these steels are more resistant to intergranular stress corrosion cracking (IGSCC) in the as-fabricated condition, this field experience establishes that the conditions under which the materials will crack in core structures are attributable to the combined effects of high residual stresses, associated with the shroud construction, the presence of a more aggressive, oxidizing environment in the core and to microstructural changes in the material. These changes result from the manufacturing process as well as thermal exposure during operation. Studies of materials that have cracked in the field, as well as high temperature material studies in the laboratory, are being performed to understand the mechanisms. The use of highly oxidizing, high purity water environments is integral to reproducing the conditions for cracking. The status of the laboratory efforts to gain understanding and to verify the mechanisms are presented. Modeling of IGSCC is also a key tool used to understand the cracking behavior of the low carbon stainless steels. The PLEDGE (Plant Life Extension Diagnosis by GE) model is used to support the hypotheses that tie together the role of the different contributing elements: residual stress, core water chemistry and microstructural features. The crack growth modeling is also used to evaluate the benefits of different strategies to manage and mitigate cracking of reactor internals such as hydrogen water chemistry. 相似文献
159.
160.
LH Gold HS Fox SJ Henriksen MJ Buchmeier MR Weed MA Taffe S Huitrón-Resendiz TF Horn FE Bloom 《Canadian Metallurgical Quarterly》1998,27(2-3):104-112
A model is proposed in which a neurovirulent, microglial-passaged, simian immunodeficiency virus (SIV) is used to produce central nervous system (CNS) pathology and behavioral deficits in rhesus monkeys reminiscent of those seen in humans infected with human immunodeficiency virus (HIV). The time course of disease progression was characterized by using functional measures of cognition and motor skill, as well as neurophysiologic monitoring. Concomitant assessment of immunological and virological parameters illustrated correspondence between impaired behavioral performance and viral pathogenesis. Convergent results were obtained from neuropathological findings indicative of significant CNS disease. In ongoing studies, this SIV model is being used to explore the behavioral sequelae of immunodeficiency virus infection, the viral and host factors leading to neurologic dysfunction, and to begin testing potential therapeutic agents. 相似文献