Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ARCHITECTURE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources
PubMed2006

Acetylcholinesterase inhibitors and sleep architecture in patients with Alzheimer's disease.

BACKGROUND AND OBJECTIVE: Studies suggest that some acetylcholinesterase inhibitors (AChEIs) increase rapid eye movement (REM) sleep and nightmares in patients with Alzheimer's disease (AD) but few have studied their effect on other sleep parameters. The objective of this study was to examine differences in sleep architecture in AD patients taking different AChEIs. METHODS: 76 participants (51 men, 25 women) [mean age = 78.2 years; SD = 7.7] with mild to moderate AD underwent medication history screening as well as polysomnography to determine the percentage of each sleep stage. Participants were divided into groups based on AChEI used: donepezil (n = 41), galantamine (n = 15), rivastigmine (n = 8) or no AChEI (n = 12). General univariate linear model analyses were performed. RESULTS: AChEI therapy had a significant effect on the percentage of stage 1 (p = 0.01) and stage 2 (p = 0.03) sleep. Patients in the donepezil group had a significantly lower percentage of stage 1 sleep than patients in the galantamine group (mean = 17.3%, SD = 11.7 vs 29.2%, SD = 15.0, respectively; p = 0.01), but there was no significant difference between the donepezil group and the rivastigmine (mean = 25.0%, SD = 12.3) or no AChEI groups (mean = 27.6%, SD = 17.7) in this respect. No significant differences in percentage of stage 1 between other groups were seen. Patients in the donepezil group also had a significantly higher percentage of stage 2 sleep than patients in the no AChEI group (mean = 63.6%, SD = 14.4 vs 51.4%, SD = 16.9, respectively; p = 0.04), but there was no significant difference between the donepezil group and either the galantamine group (mean = 56.5%, SD = 8.7) or the rivastigmine group (mean = 59.9%, SD = 8.4). There were no significant differences between groups in terms of percentage REM sleep or other sleep parameters. CONCLUSION: Subgroups of AD patients (classified according to AChEI treatment) in this study differed with respect to the amount of stage 1 and stage 2 sleep experienced, with the donepezil-treated group having the lowest percentage of stage 1 sleep and the highest percentage of stage 2 sleep. There was no significant difference in the amount of REM sleep between the groups. Our data suggest that sleep architecture may be affected by the use of donepezil in patients with AD. Although not elicited in this study because of the small sample size, there may be a class effect of AChEIs on sleep architecture. Double-blind, placebo-controlled studies are needed to better understand causality and the effect of each AChEI on sleep architecture in patients with AD.

Aged↗
PubMed2005

Evaluation of architectural changes along the proximal to distal regions of the dorsal laminar interface in the equine hoof.

OBJECTIVE: To describe architectural changes along the dorsal laminar interface of the equine foot. SAMPLE POPULATION: 6 macroscopically normal forefeet obtained from 6 equine cadavers. PROCEDURE: Histologic sections of 8 evenly spaced, proximal to distal, samples of the dorsal laminar interface were photographed, digitized, and examined for differences in architecture. Laminar depth; secondary laminar density; number and consistency of bifurcations occurring within the secondary laminae, and areas composed of primary dermal lamina, primary epidermal lamina, and secondary laminar interface were recorded. Data were examined to test for differences in architecture associated with the proximal to distal positioning of the sample. RESULTS: With exception of the areas of the primary epidermal and primary dermal lamina, all measured variables were significantly different between the proximal and distal regions of the dorsal laminar interface. Changes included increases in laminar depth and the secondary laminar density. Bifurcation of secondary laminae principally occurred proximally and had an increased depth of bifurcation distally. The secondary laminar dermal-epidermal interface had a 109% increase in area between the most proximal and distal sections. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study indicate that the interface normally contributes a substantial volume of dermal components to the internal surface of the wall. These data also indicate that 2 distinct mechanisms (i.e., bifurcation of secondary laminae and an increase in the length of secondary laminae) contribute to changes in the architecture of the laminar interface, which allows for the hypothesis that the normal laminar interface is capable of responding to mechanical load.

Animals↗
PubMed2006

"Not a shack in the woods": architecture for tuberculosis in Muskoka and Toronto.

This paper explores architecture as a primary source in the history of tuberculosis. In comparing five Ontario sanatoria built between 1897 and 1923, we identify a range of types and a growing resemblance of ex-urban TB sanatoria to urban hospitals. Existing literature on Canadian TB hospital architecture suggests the endurance of picturesque architecture, but the cottage plan was only one of the types deemed appropriate for consumptives in the early 20th century, even in Muskoka. Furthermore we argue that urban and ex-urban TB ideologies actually coalesce about 1923, best illustrated in the boldly modern architecture of Muskoka's new Gage pavilion.

History, 19th Century↗
PubMed1991

[Microvascular architecture of the human tongue carcinoma--a scanning electron microscopic study].

Vascular architecture of tumors in experimental animals has been studied in detail. However, the reports on architecture of the capillaries in human carcinoma in the head and neck regions are few nowadays. In this paper architecture of the blood vessels reproduced by using methacrylate casting medium in human carcinoma of the tongue was studied by scanning electron microscopy. Tortous capillaries and loop-like vessels were observed at the proliferative area of the tumor on the surface of the tongue. There were avascular zones around the vessels of the tumor characterizing irregular proliferation. The vessels of sinusoidal, tapering, distorted and disrupted characters were seen in the muscle layer of the tongue. Ruptured vessels and viable tumor-cells were observed at the areas surrounding necrotic lesions. These findings elucidated combination of various kinds of architectures of vessels in various stages of tumor-growing. Existence of the avascular area suggests that proliferation of tumor-cells proceeds before proliferation of the capillaries. Both avascular and necrotic changes in the structure might reduce the effects of anti-cancer agents.

Capillaries↗
PubMed1989

[Cellular architecture of papillary and nonpapillary transitional cell carcinoma].

To characterize the cellular architecture of papillary and nonpapillary transitional cell carcinoma. 2 normal ureters, 6 papillary bladder cancers and 5 nonpapillary bladder cancers were subjected to light and electron microscopic study as well as three dimensional reconstruction by 0.5 microns thick serial sections. Normal urothelium consisted of three cell layers of the basal, intermediate and superficial cells, each of which was morphologically characterized in terms of cell shape and development of cell organelles. Over 90% of the epithelial cells were proved to be connected to the uniform basement membrane directly or with long, fine cytoplasmic processes, forming hemidesmosomes at the junctional portion. Papillary tumors had, as a rule, the same cellular architecture as that of normal epithelium in terms of the regularity of cellular polarity, arrangement and differentiation, and the connection to the basement membrane. But, in G2 tumors, the connection between the intermediate and superficial cells and the basement membrane failed to be confirmed in 7 to 44% of the cells, suggesting the heterogeneity of the tumors. In contrast, nonpapillary tumors showed a high irregularity of the cellular architecture in both lesions of stromal and intra-epithelial invasion. The development of the basement membrane was indefinite, often showing thinning or disruption where occasional cytoplasmic protrusion of the tumor cells into the lamina propria was found. Nearly all of the intermediate and superficial cells in the intraepithelial lesions proved not to communicate with the basement membrane. The present results indicate distinct differences of cellular architecture between the papillary and nonpapillary urothelial tumors, which may reflect not only the growth pattern but also the biological behaviour of the individual tumors.

Basement Membrane↗
PubMed1997

Open architecture for health care systems: the European RICHE experience.

Groupe RICHE is bringing to the market of health IT the Open Systems approach allowing a new generation of health information systems to arise with benefit for patients, health care professionals, hospital managers, agencies and citizens. Groupe RICHE is a forum for exchanging information, expertise around open systems in health care. It is open to any organisation interested by open systems in health care and wanting to participate and influence the work done by its user, marketing and technical committees. The Technical Committee is in charge of the maintenance of the architecture and impact the results of industrial experiences on new releases. Any Groupe RICHE member is entitled to participate to this process. This unique approach in Europe allows health care professionals to benefit from applications supporting their business processes, including providing a cooperative working environment, a shared electronic record, in an integrated system where the information is entered only once, customised according to the user needs and available to the administrative applications. This allows Hospital managers to satisfy their health care professionals, to smoothly migrate from their existing environment (protecting their investment), to choose products in a competitive environment, being able to mix and match system components and services from different suppliers, being free to change suppliers without having to replace their existing system (minimising risk), in line with national and regional strategies. For suppliers, this means being able to commercialise products well fitted to their field of competence in a large market, reducing investments and increasing returns. The RICHE approach also allows agencies to define a strategy, allowing to create a supporting infrastructure, organising the market leaving enough freedom to health care organisations and suppliers. Such an approach is based on the definition of an open standard architecture. The RICHE esprit project defined in 1993 the three layered architecture, with four main components and their services of which the main principles have recently been adopted by the CEN TC251 as a european pre-standard. From this architecture specifications various implementations have been completed including the IMS DHE, the GESI DHE and the REFERENCE Kernel. However putting into practice this approach on a large scale is not so easy. Interesting lessons have been learned in the last years in different countries.

Computer Communication Networks↗
PubMed2001

Genetic architecture of adaptive differentiation in evolving host races of the soapberry bug, Jadera haematoloma.

To explore genetic architecture and adaptive evolution, we conducted environmental and genetic experiments with two recently (ca. 100 generations) diverged, geographically adjacent races of the soapberry bug. One race occurs on a native host plant species, the other on an introduced host. We focused on three traits: length of the mouthparts, body size and development time. The first experiment was an environmental manipulation, comparing individuals of each population reared on one or the other host species ('cross-rearing') and estimating three evolutionary rates for each trait. The first rate, 'evolutionary path' compares ancestral-derived populations when both were reared on the introduced host. The second, 'current ecological contrast' compares populations with each reared on its natal host. The third, 'evolved tradeoff' compares the two races when reared on the native host. Differences among these rates are striking and informative. For example, development time, which appears to be relatively undifferentiated phenotypically, has actually evolved very rapidly via countergradient selection. The pattern differs for each trait, and clear developmental tradeoffs have evolved as quickly as adaptation to the new host in each. The second experiment was a two-generation 'line cross' study. With joint-scaling analyses, we compared purebred, hybrid and backcrossed individuals to describe genetic architecture. Additive genetic variance for mouthpart length was consistently large (ca. 60%), but the interaction of dominance, maternal effects and epistasis was important in the other traits. Rearing host strongly affected genetic architecture. There was no clear relationship between genetic architecture and rate of evolution. Selection has produced both additive and nonadditive differentiation between the host races with surprising speed, consistent with theoretical predictions about evolution in fitness-associated traits.

Adaptation, Biological↗
PubMed2002

[Experimental study on microvascular architecture of human and rabbit flaps with two methods].

OBJECTIVE: To study effective method of showing the microvascular architecture of human and rabbit skin flaps. METHODS: According to endogenous alkaline phosphatase activity, Gomori-Takamatsu method and NBT/BCIP method were used to observe the microvascular architecture. RESULTS: Both methods had capability to demonstrate the microvascular architecture of the human skin flap, whereas the examining results of rabbits were negative. CONCLUSIONS: Great difference of endogeneous alkaline phosphatase activity exists in different animals. Gomori-Takamatsu method and NBT/BCIP method are useful in study of microvascular architecture of human skin flaps.

Alkaline Phosphatase↗
PubMed2002

[Architectural plasticity of the stoloniferous herb, Duchesnea indica in response to different elevation].

Architectural plasticity of clonal plant may modify its ways of utilization of resources through clonal growth and be of ecologically importance. The plasticity of clonal architecture in response to ecological conditions at different altitudes in a stoloniferous herb, Duchesnea indica, was investigated in an experiment with different elevations of 400, 800, 1200, and 1600 m. The results showed that the change patterns of spacer length, ramet density, branching intensity, and branching angle of Duchesnea indica were in a quadratic curve when the elevation increased. The architectural plasticity of D. indica was simulated through dynamic Logistic model, and the imitative effect was statistically preferable. Combining with the resources utilization of Duchesnea indica under different environments, the architectural plasticity was also discussed in this paper.

Altitude↗
PubMed2006

Advanced EHR architectures--promises or reality.

OBJECTIVES: Forming the informational reflection of the patients and their care, the Electronic Health Record (EHR) is the core application of any complex health information system or health network. Such an ideally lifelong history file must be reliable, flexible, adaptable to new concepts and technologies, and robust, to allow for sharing knowledge over its lifetime. A sophisticated architecture must be chosen for meeting this challenge. METHODS: An advanced EHR architecture for designing and implementing future-proof EHR systems must be a model of generic properties required for any Electronic Patient Record to provide communicable, comprehensive, useful, effective, and legally binding records that preserve their integrity over the time, independent of platforms and systems as well as of national specialties. the resulting approach is based on the ISO Reference Model-Open Distributed Processing. RESULTS: Based on advanced architectural principles introduced in the paper, a new generation of HER systems has been designed and implemented for demonstrating the feasibility of the approach. This result is presented and evaluated regarding the achievements and problems using the component-based paradigm of model-driven health information system architectures. CONCLUSIONS: The future-proof EHR approach that has been established has been shortly evaluated. Advantages regarding flexibility, reliability, and portability of policy-driven, highly secure, role-dependent applications have to be considered in the light of performance as well as of the availability of network and application services.

Computer Systems↗
PubMed2006

Semantic interoperability--HL7 Version 3 compared to advanced architecture standards.

OBJECTIVES: To meet the challenge for high quality and efficient care, highly specialized and distributed healthcare establishments have to communicate and co-operate in a semantically interoperable way. Information and communication technology must be open, flexible, scalable, knowledge-based and service-oriented as well as secure and safe. METHODS: For enabling semantic interoperability, a unified process for defining and implementing the architecture, i.e. structure and functions of the cooperating systems' components, as well as the approach for knowledge representation, i.e. the used information and its interpretation, algorithms, etc. have to be defined in a harmonized way. Deploying the Generic Component Model, systems and their components, underlying concepts and applied constraints must be formally modeled, strictly separating platform-independent from platform-specific models. RESULTS: As HL7 Version 3 claims to represent the most successful standard for semantic interoperability, HL7 has been analyzed regarding the requirements for model-driven, service-oriented design of semantic interoperable information systems, thereby moving from a communication to an architecture paradigm. The approach is compared with advanced architectural approaches for information systems such as OMG's CORBA 3 or EHR systems such as GEHR/openEHR and CEN EN 13606 Electronic Health Record Communication. CONCLUSION: HL7 Version 3 is maturing towards an architectural approach for semantic interoperability. Despite current differences, there is a close collaboration between the teams involved guaranteeing a convergence between competing approaches.

Computer Communication Networks↗
PubMed2006

Evolution of genetic architecture under directional selection.

We investigate the multilinear epistatic model under mutation-limited directional selection. We confirm previous results that only directional epistasis, in which genes on average reinforce or diminish each other's effects, contribute to the initial evolution of mutational effects. Thus, either canalization or decanalization can occur under directional selection, depending on whether positive or negative epistasis is prevalent. We then focus on the evolution of the epistatic coefficients themselves. In the absence of higher-order epistasis, positive pairwise epistasis will tend to weaken relative to additive effects, while negative pairwise epistasis will tend to become strengthened. Positive third-order epistasis will counteract these effects, while negative third-order epistasis will reinforce them. More generally, gene interactions of all orders have an inherent tendency for negative changes under directional selection, which can only be modified by higher-order directional epistasis. We identify three types of nonadditive quasi-equilibrium architectures that, although not strictly stable, can be maintained for an extended time: (1) nondirectional epistatic architectures; (2) canalized architectures with strong epistasis; and (3) near-additive architectures in which additive effects keep increasing relative to epistasis.

Biological Evolution↗
PubMed2006

The evolution of genetic architecture under frequency-dependent disruptive selection.

We propose a model to analyze a quantitative trait under frequency-dependent disruptive selection. Selection on the trait is a combination of stabilizing selection and intraspecific competition, where competition is maximal between individuals with equal phenotypes. In addition, there is a density-dependent component induced by population regulation. The trait is determined additively by a number of biallelic loci, which can have different effects on the trait value. In contrast to most previous models, we assume that the allelic effects at the loci can evolve due to epistatic interactions with the genetic background. Using a modifier approach, we derive analytical results under the assumption of weak selection and constant population size, and we investigate the full model by numerical simulations. We find that frequency-dependent disruptive selection favors the evolution of a highly asymmetric genetic architecture, where most of the genetic variation is concentrated on a small number of loci. We show that the evolution of genetic architecture can be understood in terms of the ecological niches created by competition. The phenotypic distribution of a population with an adapted genetic architecture closely matches this niche structure. Thus, evolution of the genetic architecture seems to be a plausible way for populations to adapt to regimes of frequency-dependent disruptive selection. As such, it should be seen as a potential evolutionary pathway to discrete polymorphisms and as a potential alternative to other evolutionary responses, such as the evolution of sexual dimorphism or assortative mating.

Alleles↗
PubMedDate not supplied

Rise, fall and resurrection of chromosome territories: a historical perspective. Part II. Fall and resurrection of chromosome territories during the 1950s to 1980s. Part III. Chromosome territories and the functional nuclear architecture: experiments and models from the 1990s to the present.

Part II of this historical review on the progress of nuclear architecture studies points out why the original hypothesis of chromosome territories from Carl Rabl and Theodor Boveri (described in part I) was abandoned during the 1950s and finally proven by compelling evidence forwarded by laser-uv-microbeam studies and in situ hybridization experiments. Part II also includes a section on the development of advanced light microscopic techniques breaking the classical Abbe limit written for readers with little knowledge about the present state of the theory of light microscopic resolution. These developments have made it possible to perform 3D distance measurements between genes or other specifically stained, nuclear structures with high precision at the nanometer scale. Moreover, it has become possible to record full images from fluorescent structures and perform quantitative measurements of their shapes and volumes at a level of resolution that until recently could only be achieved by electron microscopy. In part III we review the development of experiments and models of nuclear architecture since the 1990s. Emphasis is laid on the still strongly conflicting views about the basic principles of higher order chromatin organization. A concluding section explains what needs to be done to resolve these conflicts and to come closer to the final goal of all studies of the nuclear architecture, namely to understand the implications of nuclear architecture for nuclear functions.

Animals↗
PubMed1991

[Experimental study on brain damage by extracerebral compression; alteration of cerebral circulation and microvascular architectures].

Effects of extracerebral compression on cerebral circulation and microvascular architectures were investigated in 23 adult cats. Brain compression was produced by inserting 12 steel balls (5 mm in diameter) into the extradural space through a burr hole at the left temporal bone. One ball was inserted every 10 minutes. Mean arterial blood pressure (MABP), intracranial pressure (ICP) and cerebral blood flow (CBF) were measured continuously. Cerebral perfusion pressure (CPP) and cerebrovascular resistance (CVR) were then calculated. Microvascular architectures of the brain were studied by scanning electron microscopy (SEM) with cerebrovascular casting methods. CBF decreased significantly on the compressed side though CPP remained unchanged till 5 balls had been inserted. CVR increased correlatively to the numbers of balls on the compressed side while remaining unchanged during insertion of the balls on the contralateral side. In SEM study, flection and interruption of capillaries and compressed phenomenon of veins were most remarkable on the compressed side. Alterations of microvascular architectures correspond to cortical deformity in degree. These data show that increase of CVR correlating to alteration of microvascular architectures plays an important role in decrease of CBF in a compressed brain. It is thus suggested that intracranial mass lesion causing deformity of the brain must be removed in order to avoid further brain tissue damage due to microvascular lesions.

Animals↗
PubMed1990

Architectural, morphometric and photometric features and their relationship to the main subjective diagnostic clues in the grading of prostatic cancer.

Novel software was developed to perform quantitative measurements of architectural and nuclear features in tissue sections. A pilot study was then undertaken to determine the diagnostic relevance of these quantitative features in prostatic tissue and the relationship of these objective features to the subjective clues used by practicing pathologists in the grading of prostatic adenocarcinoma. From a group of 82 cases of adenocarcinoma of the prostate with long-term follow-up, a subset of 15 cases that included 5 each in Mostofi grades I, II and III was carefully selected for analysis. Consecutive sections from each case were stained with hematoxylin and eosin or the Feulgen stain for visual and cytometric evaluations, respectively. The most important differences in the objective architectural features observed between the Mostofi grade I and II cases were the number of nuclei per gland and their distance from the glandular center. Significant differences were also noted in gland size and the variation in gland size. The Mostofi grades were also significantly different in terms of quantitative high-resolution features measuring nuclear size and its variation, total nuclear DNA content and the proportion of very aneuploid nuclei. There was a fairly good agreement between many of the subjective diagnostic clues and their corresponding quantitative architectural and nuclear features. This work (1) significantly extended the capabilities of our PC-based microphotometer system to analyze glandular tissue specimens, (2) provided insight into the objective bases for the expert diagnosis of adenocarcinomas of the prostate and (3) gave preliminary evidence of the ability of quantitative architectural features and high-resolution cytometric features to discriminate between the major diagnostic categories of these lesions.

Adenocarcinoma↗
PubMed1995

[Evaluation of early colorectal cancer with submucosal invasion based on histological architecture].

To clarify the clinicopathological features of tumors with submucosal invasion, especially superficial elevated and sessile ones, histological architectures of 32 cases of submucosal invasive cancers were analyzed. They were classified into 3 types based on cross-section view: PG and NPG of Shimoda's classification and PG'. Histological architectures were drawn in accordance with these findings. In 7 PG-Ca which consisted of PG only, no apparent correlation was found between the tumor sizes and invasion depth of submucosal layer. However, 12 NPG-Ca which consisted of NPG only and 12 Mixed-Ca which include various cross-section views both showed massive invasion into the submucosa with 1 cm or more in tumor size. Therefore these two types were similar in biological behavior in terms of invasion depth. And degree of submucosal invasion tended to increase in the order of PG-Ca, Mixed-Ca and NPG-Ca. Examinating histological architectures of the Mixed-Ca tumors in details, all of these cancers were consisted of both PG and PG'. Of the 12 Mixed-Ca, 91.7% were proved to be PG dominant type. Macroscopically, I s and II a contained 88.9% and 40.0% of Mixed-Ca, respectively. In conclusion, these results suggest that PG' is a subtype of PG, and PG-Ca have a correlation between tumor invasion and alteration from PG to PG' in histological architectures among submucosal cancers. It is important to clarify morphological features of PG' in margin of I s and II a tumors in diagnosing the depth of early colorectal cancers.

Colon↗
PubMed1995

A proposed architecture for ambulatory systems development.

We have developed an architecture and application framework known as the Ambulatory Services Architecture (ASA) for computerized management of patient records for ambulatory care. Our primary design goals included the development of an architecture that will be readily adaptable to advances in technology needed to enhance computerized patient record systems (e.g., multimedia, human-computer interfaces such as voice-to-text, and a fully distributed objects, etc.) and a data model and database implementation capable of providing the flexibility and extensibility needed to support a broad spectrum of specialty medical practices. This report describes the data model, access control, and the client/server components of the Ambulatory Services Architecture.

Ambulatory Care Information Systems↗