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PubMed2005

A wireless, handheld decision support system to promote smoking cessation in primary care.

Tobacco use remains a relatively unaddressed cause of disease and death in the daily care of patients by physicians. To overcome the barriers that physicians face in addressing tobacco use and its treatment in the primary care setting, we have developed a clinical decision support system that is readily accessible through the use of familiar wireless handheld devices and supportive of treatment through the implementation of the Tobacco Use and Dependence Treatment Guideline recommendations. We adopted the Information Management Services model to ensure that the application would effectively implement the guideline. The techniques used here are readily adaptable to implementing a broad range of clinical guidelines.

Computer Systems↗

PubMed2006

Brain-derived neurotrophic factor mechanisms and function in adult synaptic plasticity: new insights and implications for therapy.

Synaptic plasticity, the fiundamental ability of synapses to undergo experience-dependent changes in synaptic strength, is thought to underlie a range of long-term adaptive responses of the central nervous system. The inability to generate or maintain appropriate changes in synaptic connectivity and neuronal circuitry is likely to impair cognitive futnction associated with many neurological and psychiatric disorders. The success of intervening therapeutic approaches will depend on the ability to target key component mechanisms in the complex process of synaptic plasticity. Brain-derived neurotrophic factor (BDNF) has emerged as a major regulator of synaptic plasticity and a key target in disorders such as major depression and Alzheimner's disease. This review discusses findings that link BDNF mechanisms in synaptic plasticity to disease mechanisms and possible future therapies.

Alzheimer Disease↗

PubMed1988

Toward a model of the calmodulin-myosin light-chain kinase complex: implications for calmodulin function.

We have developed a model for the interaction of calmodulin and the presumptive calmodulin binding domain of rabbit skeletal muscle myosin light-chain kinase. In our model there is a bend in the central helix of calmodulin such that hydrophobic patches associated with the pairs of Ca2+ binding sites: I, II and III, IV; face one another. This was accomplished by altering the psi dihedral angle at one residue: Ser-81. We have made the presumptive calmodulin binding peptide alpha-helical over its entire length. In the model, this basic amphiphilic helix fits into a cavity formed by apposition of the two hydrophobic regions of calmodulin. We suggest that this general type of model may help explain calmodulin's ability to regulate the activities of its many different targets. Small changes in the conformation of a nonhelical bend within the central helix would have large effects on the relative positions of the two halves of the molecule. In this way, calmodulin might adapt itself to a wide range of possible calmodulin binding domains. The literature pertaining to the model is discussed. We also discuss the results of our own recent investigations of calmodulin species that have been altered by site-directed mutagenesis.

Animals↗

PubMed1989

Neurologic complications of captopril treatment of neonatal hypertension.

The occurrence of neurologic abnormalities is described in a series of nine infants with chronic hypertension, in whom antihypertensive therapy decreased BP markedly and for a prolonged period, although to levels often within the normal range. All infants had mean systolic BPs greater than 113 mm Hg and elevated renin values to a mean of 134 +/- 128 ng/mL/h. Antihypertensive therapy, such as captopril, an inhibitor of angiotensin I-converting enzyme, consistently lowered the systolic BP by 20% from baseline per dose. However, the nine infants exhibited a total of 17 episodes of striking decreases in systolic BP of greater than 40% from baseline; the markedly decreased systolic BP values were usually within the normal range for corrected age. Seven of the 17 episodes were characterized by marked decrease in systolic BP, ie, decreased by 57% +/- 10%, and were prolonged, ie, remained at the lower values for 17 +/- 6 hours despite therapeutic interventions. These seven episodes were accompanied by oliguria (urine output less than 1 mL/kg/h) and neurologic abnormalities (ie, seizures). In the remaining ten episodes, the systolic BP decreased by 50% +/- 8%, but the decreases were relatively brief, ie, remained at the lower values for 2.8 +/- 2 hours. These briefer episodes were not accompanied by renal or neurologic signs. These data indicate a particular vulnerability of the cerebral and renal circulation in premature infants with chronic hypertension to decreases in systolic BP to levels that would otherwise be considered in the normal range. The findings suggest that adaptive responses in both cerebral and renal blood flow are altered by chronic hypertension in such infants.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Diseases↗

PubMed1977

[Foundations and methods of rational crown preparation].

The targeted removal of dental hard tissues for the purposes of crown stump preparation may be designated as rational if the technique used ist atraumatic and implies the deliberate use of driving systems within different speed ranges and the utilization of adapted abrasive tools in a phase-synchronous and segment-oriented manner. Goal of the preparation is to realize a copy of the clinical crown that is reduced in size, presents less details and has a defined line of preparation.

Crowns↗

PubMed1986

Ruptures of the extensor mechanism of the knee joint. Clinical results and patellofemoral articulation.

The functional results of 28 cases of rupture of the quadriceps and patellar tendons are reported. Excellent or good results were noted in 15 of 18 quadriceps and 7 of 10 patellar tendons. Radiographic comparison with the opposite knee disclosed incongruences between the patella and the femoral groove in the tangential view and/or cranial-caudal position of the patella in the lateral view in 13 of the quadriceps tendon ruptures and seven of the patellar tendon ruptures. Patients with residual pain had patellofemoral incongruity but since two-thirds of the patients with incongruity were asymptomatic, incongruity alone may not be the cause of the symptoms. There was no positive correlation to muscular strength or range of movement. Nevertheless, exact adaptation of the patellar tendon and periarticular tissue seems necessary to obtain correct patello-femoral articulation. Reinforcement of the tendon with a wire cerclage is recommended to decrease the tension on the suture line and the consequent risk of a secondary rupture. In acute ruptures of the quadriceps tendon end-to-end sutures are sufficient.

Adult↗

PubMed1985

[Pathophysiological investigations on the function of artificial hearts].

The mode of action of artificial hearts is in a wide range variable and to be adapted to different conditions of the circulatory systems. The direct regulative function of the peripheral circulation is restricted by the rigid ability of artificial hearts bound to motor drive parameters. Their great dependence on pre- and afterload already in normal calves presumes a harmonized functional capacity of the right and left ventricle. As to the situation in potential recipients of artificial hearts with considerably disturbed macro- and microhaemodynamics there are problems for the choice of suitable conditions of motor drive, in order to favour a right-left balance and an adequate volume. The substitution of the natural regulators by suitable sensors and the regulation of the artificial hearts according to haemodynamic controls and pump parameters, respectively, is necessary to achieve a balanced adequate ventricular function. This complex is subject of an intensive research.

Animals↗

PubMed1984

Recent knowledge gained from long-term observations in the field of prosthodontics.

Both cross-sectional and longitudinal studies have contributed data which provide a scientific basis to the prediction of outcome in prosthodontic treatment. 'Standard' cases have a more favourable and more predictable prognosis than those in which tooth loss is scattered about the mouth. However, the variability of patients' problems and the wide range of their abilities to adapt to denture wearing and the regular maintenance of their oral tissues significantly influence outcome. Long term success with partial prostheses lies in the time scale of 5-10 years. A prerequisite for this is a standard of oral hygiene better than practised before the loss of the dentition. Adverse factors are inadequate diagnosis and treatment planning, undetected errors in denture construction, failure of materials, thermal and abrasive effects of foods, behavioural changes in the patient and ageing. In planning the restoration of abutment teeth by inlays or crowns their suitability for attachments must be considered. As yet, there are no clear guidelines to determine when fixed or removable prostheses should be used. The design of partial dentures should be as simple as possible; they should be stable, easy to clean and, if required, easily modified. Success is most likely to attend the efforts of those dentists who use techniques with which they and their technicians are thoroughly familiar.

Adult↗

PubMed1983

Pediatric dosing of acetaminophen.

Acetaminophen (paracetamol, APAP) is one of the safest and most widely used analgesic-antipyretics in children. When compared to other analgesic-antipyretics, acetaminophen has been shown in many clinical studies to have equivalent efficacy. Based on available clinical and pharmacokinetic data, acetaminophen should be dosed with single doses in the range of 10-15 mg/kg at 4-hour intervals. However, many dosing schedules recommend inadequate amounts of acetaminophen. Dosing schedules based on weight can be constructed that will accurately keep each dose within the recommended range. Dosing also can be adapted to an age-based schedule, which will provide consistent dosing from infancy to adolescence. The principles used to derive the age-based dosing schedule have potential application for use with other pharmacologic agents, particularly nonprescription drugs.

Acetaminophen↗

PubMed1983

[Continuous treatment of asthma in children with theophylline retard].

Continuous sustained-release theophylline therapy was used in 61 children with severe asthma, aged 5 to 16 years. Mean treatment duration was 5 months 8 days (range: 8 days-16 months). The necessary dosage to obtain correct blood theophylline levels was 18 +/- 3.6 mg/kg/day (range: 10-31 mg/kg/day). The adaptation of the doses to blood theophylline levels and regular check-ups confirmed intrapatient variability and the dose-dependent disposition of theophylline. In 35 of the 42 children (82%) who were observed for more than 3 months, theophylline induced a decrease of the frequency of the attacks and a better attendance to school. Nine times out of 30, oral steroid administration or sustained-release cosyntropin injections could be stopped and in 15, the dosages could be decreased by at least 50%. Evaluations of pulmonary function, performed several times in 12 children, showed that theophylline induces significant bronchodilatation, mostly of the large bronchi.

Adolescent↗

PubMedDate not supplied

[Changes in human reaction time during adaptation to mountainous conditions].

In studies on human adaptation to mountain environment (Altai, 2.600 m) the following psychophysiological characteristics were measured: latency of simple motor reaction (RT), time of reaction to a moving object (RMO) and estimations of time intervals. It has been shown that during the first days of adaptation, RT of right and left hands significantly increases by 10% as compared to the control data (Novosibirsk), as well as weighted dispersion of these parameters. Deviations in RMO in 11--20th subsequent measurements and their dispersion increase significantly. This testifies to a destabilization of functions, due to rapid fatigue, impairment of mobility and functional efficiency of nervous centres. Further stay in mountains leads to an optimization of human time reactions: RT is shortened, deviations in RMO decrease, subjective estimation of time intervals becomes more precise. Of special interest is that improvement of psychophysiological parameters is accompanied by a sharp decline of their dispersion. Such increase in adaptability and narrowing of variations range are typical of the state of tension of regulatory systems.

Acclimatization↗

PubMed1996

An in vitro perfusion model for the determination of absorption properties of drugs in isolated rat small intestine.

A two-compartment model was developed to perform in vitro permeability studies of drugs. Preparations of surviving small intestine are continuously perfused under permanent oxygenation. The apparatus especially allows the usage of variable volumes of donor and adaptable length of intestinal segments ranging from 3 to 20 cm. Both the mucosal and the serosal side of the apparatus are open for sample collection and additional instrumentation. Due to the construction the use of high-surface activity compounds is possible. Data may be derived as absorption rates (micrograms.cm-1.min-1) and concentration increases vs. time profiles.

Animals↗

PubMed1984

Light and dark adaptation in Phycomyces phototropism.

Light and dark adaptation of the phototropism of Phycomyces sporangiophores were analyzed in the intensity range of 10(-7)-6 W X m-2. The experiments were designed to test the validity of the Delbrück-Reichardt model of adaptation (Delbrück, M., and W. Reichardt, 1956, Cellular Mechanisms in Differentiation and Growth, 3-44), and the kinetics were measured by the phototropic delay method. We found that their model describes adequately only changes of the adaptation level after small, relatively short intensity changes. For dark adaptation, we found a biphasic decay with two time constants of b1 = 1-2 min and b2 = 6.5-10 min. The model fails for light adaptation, in which the level of adaptation can overshoot the actual intensity level before it relaxes to the new intensity. The light adaptation kinetics depend critically on the height of the applied pulse as well as the intensity range. Both these features are incompatible with the Delbrück-Reichardt model and indicate that light and dark adaptation are regulated by different mechanisms. The comparison of the dark adaptation kinetics with the time course of the dark growth response shows that Phycomyces has two adaptation mechanisms: an input adaptation, which operates for the range adjustment, and an output adaptation, which directly modulates the growth response. The analysis of four different types of behavioral mutants permitted a partial genetic dissection of the adaptation mechanism. The hypertropic strain L82 and mutants with defects in the madA gene have qualitatively the same adaptation behavior as the wild type; however, the adaptation constants are altered in these strains. Mutation of the madB gene leads to loss of the fast component of the dark adaptation kinetics and to overshooting of the light adaptation under conditions where the wild type does not overshoot. Another mutant with a defect in the madC gene shows abnormal behavior after steps up in light intensity. Since the madB and madC mutants have been associated with the receptor pigment, we infer that at least part of the adaptation process is mediated by the receptor pigment.

Adaptation, Physiological↗

PubMed1991

[Analysis of cone-mediated c-waves of the chicken ERG using the spectral sensitivity under monochromatic light adaptation].

ERG c-waves were recorded from eyes of anesthetized chickens by stimulating with monochromatic bright light ranging from 460 to 620nm, under yellow or red light adaptation, using various energy levels i.e. 1, 3, 4 and 5W/m2 at the corneal surface in the former, and 3, 4 and 5W/m2 in the latter. After recording a series of c-waves, the spectral sensitivity curve for each adaptation condition was obtained. Amplitude-intensity curves showed that amplitudes increased with increment of stimulus luminance. The energy required to release a response of a given criterion magnitude was determined at each of the wavelengths investigated. The peak wavelength of the spectral sensitivity curve of the c-wave under both yellow and red light adaptation was 520 or 540nm both of which were shorter than the peak wavelength (560nm) under white light adaptation. These results showed that under the yellow and red light adaptation the sensitivity of the c-wave response to monochromatic light in the longer wavelength range was suppressed, suggesting the possibility of isolating cone-mediated c-wave response. A peak (520 or 540nm) and a shoulder (580nm) in the spectral sensitivity curves were presumed to be derived from two types of cone systems.

Adaptation, Ocular↗

PubMed1996

[Effects of fluorescein and indocyanine green angiography on subsequent dark adaptation and the electroretinogram].

BACKGROUND: In clinical practice the electroretinogram (ERG) usually should not be recorded immediately after conventional fluorescein angiography (FLA), because of the bleaching effects of strong light exposure on the course of dark adaptation and on the ERG. Currently it is not known, if indocyaningreen (ICG) angiography using the Heidelberg Retina Angiograph (HRA) has similar effects on the outer retina and if therefore the ERG should also not be recorded after ICG angiography. METHODS: Eight patients with different retinal diseases were examined. After 5 minutes of light adaptation to 160 cd/m2, Ganzfeld ERGs were repeatedly recorded using DTL electrodes during a 30 minutes dark period with a flash luminance of 0.1 cds/.m2. After this dark adaptation period a standardized ERG was recorded according to the ISCEV recommendations. This procedure was followed either by ICG angiography using the HRA or by conventional fluorescein angiography using the Canon CF 60 fundus camera. Within an interval of 5 minutes the above mentioned ERG procedure was repeated. RESULTS: ICG angiography using the HRA did neither affect the course of dark adaptation as measured by increasing b-wave amplitudes during the 30 minutes dark adaptation period, nor the values for each response of the Ganzfeld standard ERG. FLA did neither affect b-wave responses to dim stimuli, nor to stronger stimuli in the scotopic range. However, the course of dark adaptation was significantly prolonged after FLA. The maximum b-wave was not affected. CONCLUSIONS: ICG angiography using the HRA could be performed prior to the recording of the ERG, without any effect on the ERG. In contrast conventional FLA must be performed after ERG recordings, in order not to alter the electrophysiological responses.

Adult↗

PubMed1983

Transient processing in chromatic induction.

The non-additivity of steady backgrounds and superimposed test flashes was investigated with 25 observers using a hue cancellation procedure. The subject's task was to vary the ratio of two lights comprising an incremental test flash (delta R/delta G) so as to maintain a unique yellow hue (i.e. red-green equilibrium) in the presence of a long-wavelength adapting background. Measurements were obtained for four different luminances of the test flash (for each background), covering a range of 1.5-2.0 log units. The adaptive hue shifts generally support Walraven's finding that the background affects the hue of the test flash only by way of altering the spectral sensitivities of the receptors, but it does not add to the hue signals from the test flash.

Adaptation, Ocular↗

PubMed1994

The multigenic nature of RNA virus adaptation to plants.

Molecular genetic studies of RNA virus host range suggest that successful systemic infection requires many or all viral genes to have some degree of specific adaptation to the host. In some cases, accommodation to the host appears to be required for viral gene products to fulfil their primary functions in viral multiplication, while in other cases, adaptation seems to be required to avoid eliciting host defenses.

Adaptation, Physiological↗

PubMed2003

Testing evolutionary hypotheses about human biological adaptation using cross-cultural comparison.

Physiological data from a range of human populations living in different environments can provide valuable information for testing evolutionary hypotheses about human adaptation. By taking into account the effects of population history, phylogenetic comparative methods can help us determine whether variation results from selection due to particular environmental variables. These selective forces could even be due to cultural traits-which means that gene-culture co-evolution may be occurring. In this paper, we outline two examples of the use of these approaches to test adaptive hypotheses that explain global variation in two physiological traits: the first is lactose digestion capacity in adults, and the second is population sex-ratio at birth. We show that lower than average sex ratio at birth is associated with high fertility, and argue that global variation in sex ratio at birth has evolved as a response to the high physiological costs of producing boys in high fertility populations.

Adaptation, Physiological↗