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1.
OBJECTIVE: We present seven cases of acute encephalitis following measles, which were diagnosed during the epidemic that occurred in Spain in 1986. PATIENTS AND METHODS: We studied seven patients diagnosed of encephalitis due to measles. The diagnosis of measles was a made by the presence of a characteristic morbiliform rash and the detection of specific IgM antibodies. The diagnosis of encephalitis was based on the symptoms and the routine examinations of blood, CSF, EEG, CT, ophthalmic exploration and the study of the audiovisual evoked potentials. RESULTS: The patients were between 5 and 9 years of age. None of them had been previously vaccinated for measles. The symptoms of encephalitis occurred 1 to 12 days after the appearance of the rash and the most frequent symptoms were drowsiness and vomiting. All of the patients had EEG abnormalities that returned to normal 1 to 18 months after the diagnosis. One patient presented CT abnormalities. CSF examination revealed an increase of the cell count in one case. The ophthalmic exploration was normal except in one of the patients which had optic neuritis. There were no abnormalities in the audiovisual evoked potentials. All of the cases showed good evolution. Five years later, all of the patients have had a normal development. CONCLUSIONS: The correct vaccination of measles can eradicate this disease.  相似文献   

2.
Past researchers studied prototype learning by asking subjects to categorize exemplars constructed from different prototypes. This procedure is less than ideal because learning must be inferred from the percentage of correct categorizations pooled across many trials or subjects or both. An alternative procedure is proposed in which subjects are asked to reproduce their estimate of the prototype on each trial, thereby providing trial-by-trial information about changes in the estimated prototype. This procedure provides straightforward tests of three basic properties implied by several prototype learning models: additivity across exemplars, noninterference among features, and time invariance of serial position effects. An experiment is reported and the results provide reasonably good support for the properties of additivity and noninterference, but clear violations of time invariance were observed. The implications of the results for distributed-memory models and multiple-trace models of prototype learning are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

3.
BACKGROUND: Titin is a huge protein ( approximately 3 MDa) that is present in the contractile unit (sarcomere) of striated muscle and has a key role in muscle assembly and elasticity. Titin is mainly composed of two types of module (type I and II). Type I modules are found exclusively in the region of titin localised in the A band, where they are arranged in a super-repeat pattern that correlates with the ultrastructure of the thick filament. No structure of a titin type I module has been reported so far. RESULTS: We have determined the structure of a representative type I module, A71, using nuclear magnetic resonance (NMR) spectroscopy. The structure has the predicted fibronectin type III fold. Titin-specific conserved residues are either located at the putative module-module interfaces or along one side of the protein surface. Several proline residues that contribute to two stretches in a polyproline II helix conformation are solvent-exposed and line up as a continuous ribbon extending over more than two-thirds of the module surface. Homology models of the type I module N-terminal to A71 (A70) and the double module A70-A71 were used to discuss possible intermodule interactions and their role in module-module orientation. CONCLUSIONS: As residues at the module-module interfaces are highly conserved, we speculate that similar interactions govern all of the interfaces between type I modules in titin. This conservation would lead to a regular multiple array of similar surface structures. Such an arrangement would allow arrays of contiguous type I modules to expose multiple proline stretches in a highly regular way and these may act as binding sites for other thick filament proteins.  相似文献   

4.
Cationic drugs of different types and structures (antihistaminics, antiarrhythmics, sedatives, opiates, cytostatics and antibiotics, for example) are excreted in mammals by epithelial cells of the renal proximal tubules and by hepatocytes in the liver. In the proximal tubules, two functionally disparate transport systems are involved which are localized in the basolateral and luminal plasma membrane and are different from the previously identified neuronal monoamine transporters and ATP-dependent multidrug exporting proteins. Here we report the isolation of a complementary DNA from rat kidney that encodes a 556-amino-acid membrane protein, OCT1, which has the functional characteristics of organic cation uptake over the basolateral membrane of renal proximal tubules and of organic cation uptake into hepatocytes. OCT1 is not homologous to any other known protein and is found in kidney, liver and intestine. As OCT1 translocates hydrophobic and hydrophilic organic cations of different structures, it is considered to be a new prototype of polyspecific transporters that are important for drug elimination.  相似文献   

5.
An amino acid index is a set of 20 numerical values representing any of the different physicochemical and biochemical properties of amino acids. As a follow-up to the previous study, we have increased the size of the database, which currently contains 402 published indices, and re-performed the single-linkage cluster analysis. The results basically confirmed the previous findings. Another important feature of amino acids that can be represented numerically is the similarity between them. Thus, a similarity matrix, also called a mutation matrix, is a set of 20 x 20 numerical values used for protein sequence alignments and similarity searches. We have collected 42 published matrices, performed hierarchical cluster analyses and identified several clusters corresponding to the nature of the data set and the method used for constructing the mutation matrix. Further, we have tried to reproduce each mutation matrix by the combination of amino acid indices in order to understand which properties of amino acids are reflected most. There was a relationship between the PAM units of Dayhoff's mutation matrix and the volume and hydrophobicity of amino acids. The database of 402 amino acid indices and 42 amino acid mutation matrices is made publicly available on the Internet.  相似文献   

6.
Glucagon-like peptide 1 (GLP-1) is a physiological incretin hormone in normal humans explaining in part the augmented insulin response after oral versus intravenous glucose administration. In addition, GLP-1 also lowers glucagon concentrations, slows gastric emptying, stimulates (pro)insulin biosynthesis, reduces food intake upon intracerebroventricular administration in animals, and may, in addition, enhance insulin sensitivity. Therefore, GLP-1, in many aspects, opposes the Type 2-diabetic phenotype characterized by disturbed glucose-induced insulin secretory capacity, hyperglucagonaemia, moderate insulin deficiency, accelerated gastric emptying, overeating (obesity) and insulin resistance. The other incretin hormone, gastric inhibitory polypeptide (GIP), has lost almost all its activity in Type 2-diabetic patients. In contrast, GLP-1 glucose-dependently stimulates insulin secretion in diet- and sulfonylurea-treated Type 2-diabetic patients and also in patients under insulin therapy long after sulfonylurea secondary failure. Exogenous administration of GLP-1 ([7-37] or [7-36 amide]) in doses elevating plasma concentrations to approximately 3-4 fold physiological postprandial levels fully normalizes fasting hyperglycaemia in Type 2-diabetic patients. The half life of GLP-1 is too short to maintain therapeutic plasma levels for sufficient periods by subcutaneous injections. Current research activities aim at finding GLP-1 analogues with more suitable pharmacokinetic properties than the original peptide. Another approach could be the augmentation of endogenous release of GLP-1, which is abundant in L cells of the lower small intestine and the colon. Interference with sucrose digestion using alpha-glucosidase inhibition moves nutrients into distal parts of the gastrointestinal tract and, thereby, prolongs and augments GLP-1 release. Enprostil, a prostaglandin E2 analogue, fully suppresses GIP responses, while only marginally affecting insulin secretion and glucose tolerance after oral glucose, suggesting compensatory hypersecretion of additional insulinotropic peptides, possibly including GLP-1. Given the large amount of GLP-1 present in L cells, it appears worthwhile to look for more agents that could 'mobilize' this endogenous pool of the 'antidiabetogenic' gut hormone GLP-1.  相似文献   

7.
Pulmonary disease, including thromboembolic problems, accounts for a large portion of the morbidity of sickle cell disease. Chronic transfusion therapy is now a part of long-term treatment of sickle cell patients with stroke and chest syndrome. The resultant iron overload must be treated with chelation therapy using deferoxamine. Poor compliance with subcutaneous chelation therapy has necessitated intravenous deferoxamine treatment. We describe two patients with sickle cell disease on such a regimen, who became hypoxic as a result of pulmonary thromboembolism, secondary to venous thrombophlebitis. The thrombophlebitis and subsequent pulmonary embolism probably reflect the hypercoagulable state seen in sickle cell and are not due to the deferoxamine therapy.  相似文献   

8.
We have synthesized a linear, bifunctional peptide that comprises an integrin-targeting domain containing an arginine-glycine-aspartic acid tripeptide motif and a DNA-binding moiety consisting of a short stretch of 16 lysine residues. This peptide can form distinctive, condensed complexes with DNA and is capable of mediating its delivery and expression in a variety of mammalian cells in culture. Internalization is mediated by cell surface integrin receptors via a mechanism that is known to be phagocytic. We have analyzed the relationship between DNA and peptide and have investigated the conditions suitable for optimal gene delivery. The formation of condensed peptide DNA complexes leads to resistance to nuclease degradation. The level of reporter gene expression obtained is dependent on the peptide-to-DNA ratio and is enhanced in the presence of the endosomal buffer chloroquine, polyethyleneimine, and deactivated adenovirus during gene delivery. Under optimal conditions the levels of reporter gene expression obtained approach or even exceed those obtained with DNA delivered with the commercial liposome Lipofectamine. The ability to produce an efficient gene delivery system using small, easily modified, and well-defined constructs that have no constraint of particle size demonstrates the advantages of integrin-targeting peptides for gene transfer.  相似文献   

9.
介绍珠江钢铁电炉烧嘴系统改造及自动控制系统的实现.新型烧嘴装置采用由西门子S7-400控制器、HM I及现场仪表组成的控制系统,通过PID调节和顺序控制实现对氧和液化气的控制.系统自投入以来,运行稳定可靠,操作方便,取得了降低电耗、降低电极消耗、缩短冶炼周期的效果.  相似文献   

10.
Contaminated groundwater poses a significant health hazard and may also impact wildlife such as amphibians when it surfaces. Using FETAX (Frog Embryo Teratogenesis Assay-Xenopus), the developmental toxicity of ground and surface water samples near a closed municipal landfill at Norman, OK, were evaluated. The groundwater samples were taken from a network of wells in a shallow, unconfined aquifer downgradient from the landfill. Surface water samples were obtained from a pond and small stream adjacent to the landfill. Surface water samples from a reference site in similar habitat were also analyzed. Groundwater samples were highly toxic in the area near the landfill, indicating a plume of toxicants. Surface water samples from the landfill site demonstrated elevated developmental toxicity. This toxicity was temporally variable and was significantly correlated with weather conditions during the 3 days prior to sampling. Mortality was negatively correlated with cumulative rain and relative humidity. Mortality was positively correlated with solar radiation and net radiation. No significant correlations were observed between mortality and weather parameters for days 4-7 preceding sampling.  相似文献   

11.
EpoDB is a database of genes expressed in vertebrate red blood cells. It is also a prototype for the creation of cell and tissue-specific databases from multiple external sources. The information in EpoDB obtained from GenBank, SWISS-PROT, Transfac, TRRD and GERD is curated to provide high quality data for sequence analysis aimed at understanding gene regulation during erythropoiesis. New protocols have been developed for data integration and updating entries. Using a BLAST-based algorithm, we have grouped GenBank entries representing the same gene together. This sequence similarity protocol was also used to identify new entries to be included in EpoDB. We have recently implemented our database in Sybase (relational tables) in addition to SICStus Prolog to provide us with greater flexibility in asking complex queries that utilize information from multiple sources. New additions to the public web site (http://www.cbil.upenn.edu/epodb) for accessing EpoDB are the ability to retrieve groups of entries representing different variants of the same gene and to retrieve gene expression data. The BLAST query has been enhanced by incorporating BLASTView, an interactive and graphical display of BLAST results. We have also enhanced the queries for retrieving sequence from specified genes by the addition of MEME, a motif discovery tool, to the integrated analysis tools which include CLUSTALW and TESS.  相似文献   

12.
A prototype electronic science textbook for secondary education was developed to help bridge the gap between state-of-the-art medical technology and the basic science classroom. The prototype combines the latest in radiologic imaging techniques with a user-friendly multimedia computer program to teach the anatomy, physiology, and diseases of the gastrointestinal (GI) tract. The program includes original text, illustrations, photographs, animations, images from upper GI studies, plain radiographs, computed tomographic images, and three-dimensional reconstructions. These features are intended to create a stimulus-rich environment in which the high school science student can enjoy a variety of interactive experiences that will facilitate the learning process. The computer-based book is a new educational tool that promises to play a prominent role in the coming years. Current research suggests that computer-based books are valuable as an alternative educational medium. Although it is not yet clear what form textbooks will take in the future, computer-based books are already proving valuable as an alternative educational medium. For beginning students, they reinforce the material found in traditional textbooks and class presentations; for advanced students, they provide motivation to learn outside the traditional classroom.  相似文献   

13.
14.
15.
A core oligosaccharide was obtained after mild acid degradation of Legionella pneumophila serogroup 1 lipopolysaccharide (LPS). On the basis of chemical, GLC-MS, 1H, and 13C NMR spectroscopic data, it was found that the oligosaccharide obtained is a highly O-acetylated heptasaccharide having the following structure: [formula: see text] where Kdo is 3-deoxy-D-manno-octulosonic acid and QuiNAc is 2-acetamido-2,6-dideoxyglucose. In the LPS, the O-specific polysaccharide chain is linked to position 3 of the terminal rhamnosyl group and is cleaved during degradation of the LPS. The degradation also induced partial migration and partial removal of the O-acetyl group from the terminal rhamnosyl group which, together with the occurrence of the reducing Kdo residue in multiple forms, contributes to the heterogeneity of the isolated core oligosaccharide. No such highly O-acetylated core oligosaccharide has been reported so far for LPS of Gram-negative bacteria.  相似文献   

16.
17.
PAS domains are found in diverse proteins throughout all three kingdoms of life, where they apparently function in sensing and signal transduction. Although a wealth of useful sequence and functional information has become recently available, these data have not been integrated into a three-dimensional (3D) framework. The very early evolutionary development and diverse functions of PAS domains have made sequence analysis and modeling of this protein superfamily challenging. Limited sequence similarities between the approximately 50-residue PAS repeats and one region of the bacterial blue-light photosensor photoactive yellow protein (PYP), for which ground-state and light-activated crystallographic structures have been determined to high resolution, originally were identified in sequence searches using consensus sequence probes from PAS-containing proteins. Here, we found that by changing a few residues particular to PYP function, the modified PYP sequence probe also could select PAS protein sequences. By mapping a typical approximately 150-residue PAS domain sequence onto the entire crystallographic structure of PYP, we show that the PAS sequence similarities and differences are consistent with a shared 3D fold (the PAS/PYP module) with obvious potential for a ligand-binding cavity. Thus, PYP appears to prototypically exhibit all the major structural and functional features characteristic of the PAS domain superfamily: the shared PAS/PYP modular domain fold of approximately 125-150 residues, a sensor function often linked to ligand or cofactor (chromophore) binding, and signal transduction capability governed by heterodimeric assembly (to the downstream partner of PYP). This 3D PAS/PYP module provides a structural model to guide experimental testing of hypotheses regarding ligand-binding, dimerization, and signal transduction.  相似文献   

18.
OBJECTIVE: To compare characteristics and risk factors of suicide in early adolescence (younger than age 15 years) and in late adolescence. The authors examined whether differences in risk factors or resilience might explain the different suicide rates in the two age groups. METHOD: Information about all registered suicides of young people in Norway from 1990 through 1992 was gathered from several professional informants. Children younger than 15 years old who committed suicide (n = 14) were compared with late-adolescent suicides (15 through 19 years) (n = 115) and with controls (n = 889). RESULTS: Younger compared with older adolescent suicides more often hanged themselves (93% versus 35%). Suicidal ideation (7% versus 39%) and precipitating events were described less frequently (29% versus 49%). Older adolescents more often had psychiatric disorders (77% versus 43%). Compared with controls, the risk factors for suicide were affective disorders (young adolescents: odds ratio [OR] = 23.8, 95% confidence interval [CI] = 2.3 to 1,183; older adolescents: OR = 19.6, CI = 10.6 to 38.8); disruptive disorders (young adolescents: OR = 3.4, CI = 0.0 to 340; older adolescents: OR = 6.1, CI = 3.0 to 12.7); and not living with two biological parents (young adolescents: OR = 3.1, CI = 0.6 to 14.7; older adolescents: OR = 2.5, CI = 1.6 to 3.8). CONCLUSION: Children and young adolescents completing suicide were less exposed to known risk factors than older adolescents. The increased suicide risk was similar for both groups when they were compared with community controls. The low suicide incidence in childhood may be related to fewer risk factors, rather than to resilience to risk factors.  相似文献   

19.
Rats were trained to use the right forelimb to exert continuous downward pressure on a force transducer and simultaneously to drink sweetened milk from a dipper controlled by the emitted force. Oscillations in forelimb force during this performance were spectrally analyzed to describe the tremorogenic effects of haloperidol (0.04, 0.08, or 0.16 mg/kg). Haloperidol reduced time-on-task and increased the variance of force oscillations in the 10.0–25.0 Hz frequency band. When atropine sulfate (5 mg/kg) was given along with haloperidol, time-on-task was partially restored, and the effects of haloperidol on the 10.0–25.0 Hz band were diminished. These data suggest that the behavioral deficits produced by relatively low doses of haloperidol in rats are analogous (and possibly homologous) to neuroleptic-induced Parkinsonian symptoms in humans. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

20.
We characterized apneas by a quantitative method (esophageal pressure measurements) and by a qualitative method (strain gauges) at the same time in 22 patients with sleep-related breathing disorders. Detection of respiratory effort by strain gauges significantly overestimated the total number of central apneas in each patient. Despite this overestimation, none of the patients was wrongly diagnosed as having pure central sleep apnea syndrome. Strain gauges are sufficiently reliable for the characterization of apneas in most patients. When strain gauges reveal that most apneas are central in origin, verification by esophageal pressure measurements is recommended.  相似文献   

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