Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “range adaptation”

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 865 records · Page 48Linked to original sources
PubMed1999

On what evidence should education concerning depression be based?

Disease depresses. As a consequence depressed mood is almost ubiquitous in medicine. This is as true for physical disorders as it is for mental disorders. Depressed mood, moreover, seldom comes alone but is generally accompanied by other troublesome phenomena. In other words, the transition from distress towards depression is a gradual one, at least from the clinical point of view. One could therefore rightfully assume, that most physicians will be well versed in diagnosing and treating depression. Regrettably that is not the case. Depression is an under-diagnosed and under-treated disorder. Hence sophisticated educational programs to enhance the diagnostic and therapeutic skills of those frequently encountering depressive and depressed patients are much in need. The Dep Relief program is a CD-ROM program well suited for this purpose. It is wide-ranging, evidence-based, easily adaptable to various audiences and scrutinized by a panel of international experts. In short, it is an important tool to disseminate up-to-date information about mood disorders.

Depressive Disorder↗
PubMed2005

Mucispirillum schaedleri gen. nov., sp. nov., a spiral-shaped bacterium colonizing the mucus layer of the gastrointestinal tract of laboratory rodents.

The mammalian gastrointestinal tract is covered by a layer of mucus that can harbour a range of bacterial species specifically adapted to colonize this ecological niche. Examination of 110 bacterial isolates cultivated from the gastrointestinal tract of 23 mice revealed the presence of a subgroup of 30 isolates that did not correspond genetically with genera commonly associated with this site, i.e. members of the epsilon-Proteobacteria such as Helicobacter and Campylobacter species. Instead this group of isolates was found to lie within the phylum Deferribacteres, a completely distinct lineage in the domain Bacteria. There was a high level of consensus in results obtained from the phenotypic and genotypic characterization of a number of the isolates, which showed they were distinct from other members of the Deferribacteres. As such, they are proposed to constitute a new genus and species, Mucispirillum schaedleri gen. nov., sp. nov. These organisms are anaerobic, Gram-negative, spiral-shaped rods with bipolar flagella. The type strain is HRI I17(T) (= ATCC BAA-1009(T) = ACM 5223(T)).

Anaerobiosis↗
PubMed1998

Expression studies of the zeaxanthin epoxidase gene in nicotiana plumbaginifolia

Abscisic acid (ABA) is a plant hormone involved in the control of a wide range of physiological processes, including adaptation to environmental stress and seed development. In higher plants ABA is a breakdown product of xanthophyll carotenoids (C40) via the C15 intermediate xanthoxin. The ABA2 gene of Nicotiana plumbaginifolia encodes zeaxanthin epoxidase, which catalyzes the conversion of zeaxanthin to violaxanthin. In this study we analyzed steady-state levels of ABA2 mRNA in N. plumbaginifolia. The ABA2 mRNA accumulated in all plant organs, but transcript levels were found to be higher in aerial parts (stems and leaves) than in roots and seeds. In leaves ABA2 mRNA accumulation displayed a day/night cycle; however, the ABA2 protein level remained constant. In roots no diurnal fluctuation in mRNA levels was observed. In seeds the ABA2 mRNA level peaked around the middle of development, when ABA content has been shown to increase in many species. In conditions of drought stress, ABA levels increased in both leaves and roots. A concomitant accumulation of ABA2 mRNA was observed in roots but not in leaves. These results are discussed in relation to the role of zeaxanthin epoxidase both in the xanthophyll cycle and in the synthesis of ABA precursors.

Journal Article↗
PubMedDate not supplied

The development of infants' reaches for stationary and moving targets.

The organization of infants' reaching skill for stationary and moving targets was examined. While 58 term, healthy infants at 5.5, 8.5, and 11.5 months of age reached for and grasped a cloth-covered dowel, their reaches were videotaped for later slow-motion analysis. Analyses addressed infants' anticipatory adjustment of hand alignment, use of information from spinning and oscillating targets to update ongoing reaches, and ability to capture targets moving in depth. Infants at all ages made anticipatory adjustments of hand alignment, although the effectiveness of these adjustments improved with age. Regardless of age, infants also used dynamic information from spinning and oscillating targets to update ongoing reaches, but the way infants used this information was related to age. Developmental constancy characterized infants' reaches for approaching targets. By observing infants' reaches for stationary, spinning, and approaching targets, the study expands the range of conditions under which adaptive reaching skill has been examined and provides insight into the roles of anticipation and updating in the development of early manual skill.

Age Factors↗
PubMed1999

The meaning of lung dose.

For a physician to understand how to prescribe appropriate doses of drugs via aerosol requires a basic understanding of the technical issues involved. Drugs are usually prescribed in terms of "nominal dose" (total dose of drug prescribed). This dose is device-specific, as recommended doses are different for different devices. The effective component of the nominal dose is the "lung dose", which is the mass of drug delivered to the lung. A given clinical effect should, in general, be produced by a given lung dose irrespective of the delivery device. However, the effect of a lung dose depends on several factors, including: 1) site of deposition 2) rate of clearance of the drug from airway 3) site of action of the drug. Confirmation that a particular lung dose will produce a desired clinical effect usually requires that a clinical trial be performed. The lung dose should be reflected by data on lung deposition, but interpreting such data requires that the following are considered: 1) Lung deposition figures can be stated in different ways: a) percentage of the nominal dose b) percentage of the mass of drug leaving the aerosol-generating device c) percentage of the mass of drug entering the mouth or nose. 2) The radiation from an inhaled aerosol is attenuated as it leaves the lung. Approaches vary as to how this correction is done, affecting the quoted data on percent deposition. 3) In children, lung deposition is age-dependent, but the effect of age on delivery is different for different devices. There are major differences in the efficiency of delivery for different devices with a range of 6-60%. When "adaptive aerosol delivery" nebulizers become available, they should provide an accurate dose of drug to the lung with very low variability. In summary, the concept of lung dose is useful in understanding the related technical aspects, and it has the potential to allow drugs to be prescribed more accurately.

Administration, Inhalation↗
PubMed2005

A chronic disease outreach program for Aboriginal communities.

BACKGROUND: Our objective is to describe a program to improve awareness and management of hypertension, renal disease, and diabetes in 3 remote Australian Aboriginal communities. METHODS: The program espouses that regular integrated checks for chronic disease and their risk factors are essential elements of regular adult health care. Programs should be run by local health workers, following algorithms for testing and treatment, with backup, usually from a distance, from nurse coordinators. Constant evaluation is essential to develop community health profiles and adapt program structure. RESULTS: Participation ranged from 65% to 100% of adults. Forty-one percent of women and 72% of men were current smokers. Body weight varied markedly by community. Although excessive in all, rates of chronic diseases also differed markedly among communities. Rates increased with age, but the greatest numbers of people with morbidities were middle age and young adults. Multiple morbidities were common by middle age. Hypertension and renal disease were early features, whereas diabetes was a variable and later manifestation of this integrated chronic disease syndrome. Adherence to testing and treatment protocols improved markedly over time. Substantial numbers of new diagnoses were made. Blood pressure improved in people in whom antihypertensive agents were started or increased. Components of a systematic activity plan became more clearly defined with time. Treatment of people in the community with the greatest disease burden posed a large additional workload. Lack of health workers and absenteeism were major impediments to productivity. CONCLUSION: We cannot generalize about body habitus, and chronic disease rates among Aboriginal adults. Pilot data are needed to plan resources based on the chronic disease burden in each community. Systematic screening is useful in identifying high-risk individuals, most at an early treatable stage. Community-based health profiles provide critical information for the development of rational health policy and needs-based health services.

Adult↗
PubMed1998

First experience with an automatic sensing algorithm in single-lead VDD stimulation.

UNLABELLED: An "Autosensing" algorithm available in SSI(R) and DDR(R) pacemakers automatically adapts the device's sensitivity to changing intracardiac signals. The atrial sensing function of this algorithm was tested for the first time with a VDD pacing system in which large variations of the atrial signal may occur because the atrial electrodes float in the atrial blood pool. METHODS: 15 patients with a VDD pacing system were studied (Unity 292-07, lead 425; Sulzer Intermedics). The atrial sensing threshold was measured, and the atrial sensitivity was programmed with a 2:1 safety margin. The autosensing algorithm and sensitivity profile were temporarily activated, and an ambulatory ECG with continuous marker annotation was recorded. All patients underwent a 30-minute daily life activities protocol. A beat-to-beat analysis of the ambulatory ECG was correlated with the changes in atrial sensitivity. RESULTS: The algorithm changed the baseline sensitivity from 0.57 +/- 0.23 mV during the test to 0.39 +/- 0.20 mV after the final rest period (P < 0.05). During the test 12.6 +/- 10.2 adaptations of the sensitivity occurred (range 0-33). In eight patients atrial undersensing occurred in 4.4% +/- 7.5% of the cycles (4-458 unsensed P waves). In these patients, the algorithm continuously adjusted the sensitivity towards more sensitive values, operating 19.1 +/- 18.3 changes compared with 5.4 +/- 7.3 changes in patients without undersensing (P = 0.009). Oversensing did not occur. CONCLUSION: The autosensing algorithm effectively optimized atrial sensitivity in VDD pacing. In patients with atrial undersensing the algorithm continuously remained near the most sensitive settings, thus reacting as intended. A faster sensitivity adjustment of the system would be desirable.

Activities of Daily Living↗
PubMed2001

Master athletes.

Over the past 3 decades, there has been a continued increase in the number of "older" participants in sporting events such as running, swimming, cycling, rowing, and weightlifting. Some master athletes come from a background with years of training and competition experience, while others have only begun to compete as they approach middle-aged and older. The majority of what we currently know about master athletes and aging has been gained from both cross-sectional and longitudinal testing and re-testing master athletes and recreational athletes. The focus of this paper is on the physiological profile of athletes and individuals performing regular exercise training. Physiological data from elite and non-elite, recreational, sedentary, and senior athletes clearly indicate that human skeletal muscle has a high degree of plasticity that is maintained late into life. Muscle fiber protein expression and single muscle fiber contractile properties are greatly influenced by exercise training. It appears that skeletal muscle can quickly adapt to accommodate a wide range of functionality to meet the demands (or lack of demands) placed upon it.

Aging↗
PubMed1985

Response of the microflora in outdoor experimental streams to pentachlorophenol: compartmental contributions.

Outdoor artificial streams were treated continuously with pentachlorophenol (PCP) for 88 days during the summer of 1983. The contributions of different stream compartments (microbial habitats) to microbial degradation of PCP were determined in a stream treated with 144 micrograms of PCP per liter. The 488-m long stream was composed of mud-bottomed pools alternating with gravel riffles. PCP loss in the stream attributable to microbial degradation after an adaptation period was in the range of 55 to 74%. Contributions to PCP loss were determined for rock surface (epilithic), macrophyte surface (epiphytic), sedimentary, and water column communities by measuring rates of PCP disappearance in stream water, containing ambient concentrations of PCP, in contact with representative compartmental samples. The specific capability, in units of micrograms of PCP per hour per square meter of stream cross-sectional area (macrophytes at maximum plant density, water column at mean depth, upper 10-cm layer of gravel), followed the order rock surface much greater than macrophytes greater than sediment approximately equal to water column. The compartmental contribution to total stream losses in units of grams per hour followed the same order, although the differences were smaller. The rate of PCP disappearance in the water column above sediment cores followed the order oxygen-rich greater than oxygen-poor approximately equal to anaerobic greater than sorption-only conditions. The large difference in specific capability between the rock surface and sediment compartments could be attributed to oxygen deficiency (because of chemical and biological oxygen demand) in the sediments. Free-floating and particle-attached organisms in the water column were important to PCP biodegradation.

Aerobiosis↗
PubMed1999

Thermal gradient gel electrophoresis analysis of bioprotection from pollutant shocks in the activated sludge microbial community.

We used a culture-independent approach, namely, thermal gradient gel electrophoresis (TGGE) analysis of ribosomal sequences amplified directly from community DNA, to determine changes in the structure of the microbial community following phenol shocks in the highly complex activated sludge ecosystem. Parallel experimental model sewage plants were given shock loads of chlorinated and methylated phenols and simultaneously were inoculated (i) with a genetically engineered microorganism (GEM) able to degrade the added substituted phenols or (ii) with the nonengineered parental strain. The sludge community DNA was extracted, and 16S rDNA was amplified and analyzed by TGGE. To allow quantitative analysis of TGGE banding patterns, they were normalized to an external standard. The samples were then compared with each other for similarity by using the coefficient of Dice. The Shannon index of diversity, H, was calculated for each sludge sample, which made it possible to determine changes in community diversity. We observed a breakdown in community structure following shock loads of phenols by a decrease in the Shannon index of diversity from 1.13 to 0.22 in the noninoculated system. Inoculation with the GEM (Pseudomonas sp. strain B13 SN45RE) effectively protected the microbial community, as indicated by the maintenance of a high diversity throughout the shock load experiment (H decreased from 1.03 to only 0.82). Inoculation with the nonengineered parental strain, Pseudomonas sp. strain B13, did not protect the microbial community from being severely disturbed; H decreased from 1.22 to 0.46 for a 3-chlorophenol-4-methylphenol shock and from 1.03 to 0.70 for a 4-chlorophenol-4-methylphenol shock. The catabolic trait present in the GEM allowed for bioprotection of the activated sludge community from breakdown caused by toxic shock loading. In-depth TGGE analysis with similarity and diversity algorithms proved to be a very sensitive tool to monitor changes in the structure of the activated sludge microbial community, ranging from subtle shifts during adaptation to laboratory conditions to complete collapse following pollutant shocks.

Bacteria↗
PubMed2003

Membrane fluidity adjustments in ethanol-stressed Oenococcus oeni cells.

The effect of ethanol on the cytoplasmic membrane of Oenococcus oeni cells and the role of membrane changes in the acquired tolerance to ethanol were investigated. Membrane tolerance to ethanol was defined as the resistance to ethanol-induced leakage of preloaded carboxyfluorescein (cF) from cells. To probe the fluidity of the cytoplasmic membrane, intact cells were labeled with doxyl-stearic acids and analyzed by electron spin resonance spectroscopy. Although the effect of ethanol was noticeable across the width of the membrane, we focused on fluidity changes at the lipid-water interface. Fluidity increased with increasing concentrations of ethanol. Cells responded to growth in the presence of 8% (vol/vol) ethanol by decreasing fluidity. Upon exposure to a range of ethanol concentrations, these adapted cells had reduced fluidity and cF leakage compared with cells grown in the absence of ethanol. Analysis of the membrane composition revealed an increase in the degree of fatty acid unsaturation and a decrease in the total amount of lipids in the cells grown in the presence of 8% (vol/vol) ethanol. Preexposure for 2 h to 12% (vol/vol) ethanol also reduced membrane fluidity and cF leakage. This short-term adaptation was not prevented in the presence of chloramphenicol, suggesting that de novo protein synthesis was not involved. We found a strong correlation between fluidity and cF leakage for all treatments and alcohol concentrations tested. We propose that the protective effect of growth in the presence of ethanol is, to a large extent, based on modification of the physicochemical state of the membrane, i.e., cells adjust their membrane permeability by decreasing fluidity at the lipid-water interface.

Adaptation, Physiological↗
PubMed2004

Identification of the hypoxia-inducible factor 1 alpha-responsive HGTD-P gene as a mediator in the mitochondrial apoptotic pathway.

Hypoxia-inducible factor 1 alpha (HIF-1 alpha) controls the cellular responses to hypoxia, activating transcription of a range of genes involved in adaptive processes such as increasing glycolysis and promoting angiogenesis. However, paradoxically, HIF-1 alpha also participates in hypoxic cell death. Several gene products, such as BNip3, RTP801, and Noxa, were identified as HIF-1 alpha-responsive proapoptotic proteins, but the complicated hypoxic cell death pathways could not be completely explained by the few known genes. Moreover, molecules linking the proapoptotic signals of HIF-1 alpha directly to mitochondrial permeability transition are missing. In this work, we report the identification of an HIF-1 alpha-responsive proapoptotic molecule, HGTD-P. Its expression was directly regulated by HIF-1 alpha through a hypoxia-responsive element on the HGTD-P promoter region. When overexpressed, HGTD-P was localized to mitochondria and facilitated apoptotic cell death via typical mitochondrial apoptotic cascades, including permeability transition, cytochrome c release, and caspase 9 activation. In the process of permeability transition induction, the death-inducing domain of HGTD-P physically interacted with the voltage-dependent anion channel. In addition, suppression of HGTD-P expression by small interfering RNA or antisense oligonucleotides protected against hypoxic cell death. Taken together, our data indicate that HGTD-P is a new HIF-1 alpha-responsive proapoptotic molecule that activates mitochondrial apoptotic cascades.

Animals↗
PubMedDate not supplied

Science and practice: a case for medical informatics as a local science of design.

Because scientific research is guided by concerns for uncovering "fundamental truths," its time frame differs from that of design, development, and practice, which are driven by immediate needs for practical solutions. In medicine, however, as in other disciplines, basic scientists, developers, and practitioners are being called on increasingly to forge new alliances and work toward common goals. The authors propose that medical informatics be construed as a local science of design. A local science seeks to explain aspects of a domain rather than derive a set of unifying principles. Design is concerned with the creation, implementation, and adaptation of artifacts in a range of settings. The authors explore the implications of this point of view and endeavor to characterize the nature of informatics research, the relationship between theory and practice, and issues of scientific validity and generalizability. They argue for a more pluralistic approach to medical informatics in building a cumulative body of knowledge.

Computer Systems↗
PubMed1984

Calcium and myocardial cell injury. An appraisal in the cardiomyopathic hamster.

The heart muscle is very compliant within a wide range of physiologic impulses. The adaptive energy of the myocardium depends, however, upon adequate oxygen supply and the functional state of the plasmalemma. These limitations have been well demonstrated in a number of experimental models with emphasis on the essential role of Ca2+ transmembrane movements for maintenance of heart functions and its viability. This postulate appeared quite important when we found that Ca2+ slow channel blockers could prevent necrotic changes in hamster hereditary cardiomyopathy. However, the effectiveness of beta-adrenoagonists when given in low doses seems more difficult to interpret since these agonists can only promote Ca2+ transmembrane movements. We can only surmise that Ca2+ accumulation in cardiomyopathic hearts does not derive from a primary defect of the plasmalemma but rather from an exhausted hypokinetic state that favours Ca2+ accumulation with progressive deterioration of the structural proteins. It is thus inferred that Ca2+ mediates rather than initiates the degradation process which characterizes this inherited cardiomyopathy.

Animals↗
PubMed1978

Intracellular staining reveals different levels of stratification for on- and off-center ganglion cells in cat retina.

1. Ganglion cells in the retina of the cat were stained by intracellular dye injection after recording their responses to photic stimulation. 2. All cells encountered were divided into those giving on-responses and those producing off-responses, and the level of dendritic branching of these two groups was compared. Cells giving off-responses were found to branch high in the inner plexiform layer (IPL), near the amacrine cell bodies (sublamina a); those giving on-responses were found to branch lower in the inner plexiform layer (sublamina b). 3. Dye-injected cells varied widely in morphology and size, having cell bodies ranging in diameter from 8 to 32 micrometer and dendritic fields ranging from 25 to 490 micrometer in diameter; yet the sign of the response of each unit correlated only with the level of dendritic branching. Thus, no other morphological feature except stratification appears to be important in determining the sign of the response of these cells. 4. The stratification of ganglion cells into on- and off-layers parallels the distribution of the axon terminals of the flat and invaginating cone bipolars. Flat cone bipolars are in a position to contact off-center ganglion cells (in sublamina a) and invaginating cone bipolars are in a position to contact on-center ganglion cells (in sublamina b). 5. The rod and cone inputs to some cells were characterized by comparing their responses to deep red and blue rod-matched stimuli over a 2-log unit range starting at dark-adapted threshold. About half the cells appeared to be rod dominated under these conditions, whereas the others appeared to have mixed rod and cone signals. 6. The nature of the rod and cone pathways to ganglion cells is discussed.

Animals↗
PubMed2003

Evolution of forebrain and spatial cognition in vertebrates: conservation across diversity.

Historically the dominant trend in comparative brain and behavior research has emphasized the differences in cognition and its neural basis among species. In fact, the vertebrate forebrain shows a remarkable range of diversity and specialized adaptations. Probably the major morphological variation is that observed in the telencephalon of the actinopterygian fish, which undergoes a process of eversion during embryonic development, relative to the telencephalon of non-actinopterygians (for instance, amniotes), which develops by a process of evagination. These different developmental processes produce notable variation, mainly two solid telencephalic hemispheres separated by a unique ventricle in the actinopterygian radiation that contrasts with the hemispheres with internal ventricles in other groups. However, an increasing amount of evidence reveals that the forebrain of vertebrates, whether everted or evaginated, presents a common pattern of basic organization that supports highly conserved cognitive functions. We analyze here recent data indicating a close functional similarity between spatial cognition mechanisms in different groups of vertebrates, mammals, birds, reptiles, and teleost fish, and we show in addition that they rely on homologous neural mechanisms. Thus, recent functional and behavioral comparative evidence is added to the developmental and neuroanatomical data suggesting that the evolution of cognitive capabilities and their neural basis in vertebrates could have been more conservative than previously realized.

Animals↗
PubMed1997

The 1996 Massry Prize. Inositol trisphosphate and calcium: two interacting second messengers.

Inositol trisphosphate (InsP3) functions as a second messenger to control the release of internal calcium and the entry of external calcium. This InsP3/Ca2+ signalling pathway is based on a hierachical system with the release from individual channels being the fundamental event (Ca2+ blips). A collection of blips produces larger elementary events (Ca2+ puffs) which then fuse through a regenerative process of calcium-induced calcium release to give global events (Ca2+ waves). This highly versatile signalling system has been adapted to regulate a wide range of cellular processes including fertilization, development, proliferation and apoptosis.

Animals↗
PubMed2002

Viral pharmacodynamic model for (-)-beta-2',3'-dideoxy-5-fluoro-3'-thiacytidine (emtricitabine) in chronically infected woodchucks.

There is a need for adequate models of virus depletion in animals and humans as a function of drug dose in order to plan starting dose regimens in the clinic for new antiretroviral nucleoside agents. An indirect response pharmacodynamic model was fitted to link the plasma pharmacokinetics from a 28 day treatment with the nucleoside reverse transcription inhibitor emtricitabine [(-)-FTC], with the resulting virus depletion and recovery profiles in woodchucks chronically infected with woodchuck hepatitis B virus. In this approach it is assumed that the virus is eliminated from serum in a first order fashion and that the fraction of serum virus load produced per day is inhibited by the accumulation of nucleoside triphosphate in a manner that could be described using a Hill equation. Nadir virus load values were inversely related to pretreatment virus load levels within each dose group. A median inhibitory concentration value of 1.5 microM for (-)-FTC triphosphate, previously measured against the isolated viral polymerase of woodchuck hepatitis, was used in model fitting. The fitted value for concentration exponent eta of 3.46 indicated a greater than linear sensitivity of virus inhibition with dose. Since the post-treatment virus rebound was much greater than predictions of an initial model, a dose-dependent rebound factor was incorporated in the final model. The rebound factor was maximal at the end of (-)-FTC treatment and decayed mono-exponentially with a rate constant Kreb of 0.11/day. The model inferred decay half-life of (-)-FTC triphosphate in the apparent 'effect compartment' of the model was similar to the half-life value previously estimated for human hepatitis B virus-infected hepatocytes. The model described adequately the virus depletion and recovery profiles for the dose range tested and could be adapted for the selection of starting doses for future animal and human studies with emtricitabine and other nucleoside analogues in development.

Animals↗