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PubMed1993

Basics of three-dimensional endoscopic vision.

The requirement of stereoscopic vision is based on the need for controlled manipulations in the object space. With the introduction of endoscopic surgery stereoscopic controlled manipulations proved to be helpful. Beyond this, the enhanced perceptibility of details and surfaces of pathological structures brought about by stereoscopy may lead to improvements in endoscopic diagnosis. The basic principle of stereoendoscopy is to make use of a combination of two monocular endoscopes aligned and adjusted for stereoscopic vision. The small objective base provides good perception of depth in a certain region close to the tip of the stereoendoscope. A set of stereoscopic equipment consists of various stereoendoscopes, a stereoscopic observing adapter, a stereo-video camera, and a stereoscopic monitor.

Accommodation, Ocular↗

PubMed1996

Adaptive demands along the HIV disease continuum.

Our knowledge of the problems or adaptive demands associated with HIV infection has largely been derived from clinical history taking and qualitative research of persons with AIDS. This study uses a behaviour-analytic approach to systematically describe and quantify the specific adaptive demands encountered by persons with HIV across the disease continuum. Ninety six HIV-infected gay men and 33 seronegative comparison group participants were interviewed in depth. Participants were divided into three groups representing the disease continuum: seronegative, HIV asymptomatic and HIV symptomatic groups. Responses to a Problem Checklist were statistically and content analysed. Distressing emotions, relationship difficulties and HIV-related symptoms were the three most frequently endorsed problems and were also the three most frequently reported problems of most concern. Overall there was a trend for instrumental difficulties to increase with disease progression, whereas emotional and existential problems did not vary as a function of HIV stage. The behaviour-analytic approach to the specification of problems related to HIV infection has implications for both clinical and research endeavours. The specification of problems provided a means for accurately identifying common problems to target and could, therefore, provide the basis for developing suitably matched interventions for use with HIV-infected persons.

Adaptation, Psychological↗

PubMed1996

Muscle biopsy as a tool for assessing muscular adaptation to training in horses.

OBJECTIVE: To describe an applied method for quantitative estimation of training condition in horses. ANIMALS: 17 sedentary adult (5 to 14 years old) stallions of several breeds endurance trained for 3 months. PROCEDURE: Muscle biopsy specimens from 2 depths (20 and 60 mm) of the gluteus medius muscle were obtained before and after training and were analyzed for fiber type distribution, mean cross-sectional area, relative fiber area, and mean number of capillaries in contact with each fiber type relative to their mean area. Fiber types were designated as types 1, 2A, and 2B (high, low, and moderate myosin ATPase activities at pH 4.5, respectively). Data were subjected to discriminant and principal component analyses. RESULTS: 77% of the observations were correctly discriminated according to training condition of horses by use of discriminant analyses when histochemical and morphometric data from the 2 muscle biopsy specimens were used. Principal component analysis indicated that the most efficient variables describing muscular adaptation to training are fiber area and number of capillaries in contact with type-1 and type-2A fibers, particularly from the deepest sampling site of the muscle. CONCLUSION: It is possible to satisfactorily classify an individual horse in a given training category on the basis of a physiologic muscle index. CLINICAL RELEVANCE: These methods could become a useful aid for evaluation of the individual horse's response to training.

Acclimatization↗

PubMed2004

The structural adaptations in compressed articular cartilage by microscopic MRI (microMRI) T(2) anisotropy.

OBJECTIVES: To detect structural adaptations of collagen fiber matrix in compressed articular cartilage in individual sub-tissue zones by microscopic magnetic resonance imaging (microMRI) at 23 microm in-depth resolution. DESIGN: Each of the six beagle humeral cartilage specimens was placed in a specially built nonmetallic compression device inside an in-situ rotation device, and was imaged four times at 7T: without and during static compression, and at two orientations: 0 degrees and 55 degrees . Proton intensity images and quantitative T(2) maps were constructed and analyzed. RESULTS: Upon compression at 55 degrees (the magic angle), rather than appearing homogenous, T(2)-weighted intensity images of cartilage showed a distinct laminar appearance and the T(2) profiles exhibited two distinctive peaks. At both 0 degrees and 55 degrees orientations, lower values of T(2) were observed in compressed tissue. A significant correlation was established between changes in tissue T(2) at 55 degrees and a thickness reduction due to compression. At a mean of 20% strain value, modifications in cartilage structure were studied at each histological zone. We found that the percentage of superficial zone was significantly doubled, the percentage of radial zone was significantly decreased by 10%, and no significant change in the transitional zone. CONCLUSIONS: External loading can induce a new kind of laminar appearance at the magic angle. microMRI T(2) anisotropy can be used to analyze the zone-specific alterations in collagen fibril organization in articular cartilage in response to mechanical compression.

Adaptation, Physiological↗

PubMed2003

Target-controlled infusion of propofol and remifentanil in cardiac anaesthesia: influence of age on predicted effect-site concentrations.

BACKGROUND: Propofol-anaesthesia administrated via target-controlled infusion (TCI) has been proposed for cardiac surgery. Age-related changes in pharmacology explain why propofol dose requirement is reduced in elderly patients. However, the Marsh pharmacokinetic model incorporated in the Diprifusor propofol device does not take age into account as a covariable. In the absence of depth of anaesthesia monitoring, this limitation could cause adverse cardiovascular effects resulting from propofol overdose in older patients. We assessed the influence of age on effect-site propofol concentrations predicted by the Diprifusor and titrated to the bispectral index score (BIS) during cardiac anaesthesia. METHODS: Forty-five patients received propofol by Diprifusor and remifentanil by software including Minto model. Propofol and remifentanil effect-site concentrations were adapted to BIS (40-60) and haemodynamic profile, respectively. The influence of age on effect-site concentrations was assessed by dividing patients into two groups: young (<65 yr) and elderly (> or =65 yr). RESULTS: For a similar depth of anaesthesia, effect-site propofol concentrations were significantly lower in elderly patients at the different stages of cardiac surgery. The mean dose of propofol required to perform tracheal intubation was significantly lower in elderly patients. However, the overall doses of propofol were comparable in both groups. Neither effect-site remifentanil concentrations nor overall doses of remifentanil were significantly different between the two groups. CONCLUSIONS: In cardiac anaesthesia, target concentrations of propofol must be reduced in elderly patients. Although this probably contributes to improving intraoperative haemodynamic stability, the absence of decrease in overall dose requirement of propofol suggests that this adjustment is relatively moderate.

Adolescent↗

PubMedDate not supplied

Use of focus groups to identify concerns about dialysis. Choice Study.

BACKGROUND: Patients with end-stage renal disease (ESRD) may have quality-of-life (QOL) concerns that are not fully appreciated by their providers. The authors conducted focus groups with dialysis patients and dialysis professionals to determine whether this qualitative method would reveal differences between patients' and providers' views about: 1) domains of QOL that are affected by ESRD and dialysis; and 2) aspects of dialysis that affect QOL. METHODS: Separate focus group discussions were held with: 8 adult hemodialysis patients (mean age 50 years; 3 women; mean duration of dialysis 8.5 years), 5 adult peritoneal dialysis patients (mean age 54 years; 3 women; mean duration of dialysis 4.6 years), 8 nephrologists (mean of 12 years of dialysis practice), and 9 other health professionals involved in dialysis care (3 nurses, 2 dietitians, 2 social workers, and 2 technicians; mean of 10 years experience in dialysis care). Discussions were audiotaped, transcribed verbatim, and reviewed independently by three investigators to identify and categorize distinct thoughts. RESULTS: 1,271 distinct thoughts were identified and grouped into 20 related categories, which included ten QOL domains and ten aspects of dialysis that affect QOL. Compared with the professionals, the patients identified one additional relevant QOL domain (10 vs 9), and one additional aspect of dialysis that affects QOL (10 vs 9), and expressed more thoughts per domain (p < 0.05), although the contents of their comments were frequently similar. Among QOL domains, the numbers of related thoughts identified by patients and professionals, respectively, were: freedom/control (60, 89); social relationships (36, 11); anxiety (37, 4); role function (24, 10); energy (12, 10); body image (16, 4); sex (11, 21); mental attitude (21, 0); sleep (15, 1), and cognitive function (13, 7). Among aspects of dialysis that affect QOL, the numbers of thoughts identified by patients and professionals were: general dialysis issues (159, 105); relationships with staff (62, 110); patient education (63, 68); diet (44, 40); scheduling (57, 3); vascular or peritoneal access issues (31, 17), adaptation to dialysis (16, 14); dialysis dose (18, 8); symptoms (25, 0), and self-care (5, 24). CONCLUSIONS: Although health professionals have a good understanding of patient concerns about the effects of ESRD and dialysis, the focus group discussions revealed a breadth and depth of QOL concerns that they may not fully appreciate.

Adaptation, Psychological↗

PubMed1992

An intensity-dependent biphasic neuron in mudpuppy retina.

Intracellular recordings in dark-adapted mudpuppy retinas have revealed a type of infrequently encountered cell with unusual response properties. These cells may be a subclass of horizontal cell since they are encountered at the same depth as horizontal cells and have large receptive fields and response amplitudes. However, they differ from typical horizontal cells in that they are depolarized by low intensity illumination and hyperpolarized by higher intensity illumination at all wavelengths. Both types of responses appear to be driven mainly by 572 nm cones. Both the depolarizing and hyperpolarizing responses were unaffected by APB, indicating that they are not mediated by on-center bipolar cells.

Animals↗

PubMed2007

Looking after well siblings of adolescent girls with anorexia: an important parental role.

BACKGROUND: Research has suggested that well siblings of children with chronic and life-threatening illnesses are at risk for negative outcomes and that parents' responses to the illnesses can influence the adaptation of well siblings. Yet, parents' efforts to look after well siblings in the context of illness are rarely considered in literature about sibling adaptation. The importance of attending to the needs of well siblings was a major theme to emerge from a qualitative analysis of the experiences of parents of adolescent girls with anorexia nervosa. METHODS: In-depth interviews were conducted with 24 parents of adolescent girls with anorexia and analysed using grounded theory method. RESULTS: The data indicated that parents viewed caring for well siblings in the context of anorexia as an important role and responsibility. Parents reported making conscious and active efforts to look after well siblings by: maintaining normality; compensating for changes to routines; protecting siblings; providing emotional support; and managing the consequences. CONCLUSIONS: This paper provides a picture of the actions parents take to help well siblings adapt to anorexia in the family. Further research is needed to develop and expand this understanding to families experiencing a wide range of chronic and life-threatening illnesses. The findings underline the importance of clinical attention and further research into the critical parental role of caring for well siblings.

Adaptation, Psychological↗

PubMed2000

[Correction of autonomic reactions parameters in organism of cosmonaut with adaptive biocontrol method].

Presented are results of testing the method of adaptive biocontrol during preflight training of cosmonauts. Within the MIR-25 crew, a high level of controllability of the autonomous reactions was characteristic of Flight Commanders MIR-23 and MIR-25 and flight Engineer MIR-23, while Flight Engineer MIR-25 displayed a weak intricate dependence of these reactions on the depth of relaxation or strain.

Adaptation, Physiological↗

PubMed2005

Evidence for active Wnt signaling during postresection intestinal adaptation.

BACKGROUND: In the intestine, Wnt proteins are powerful regulators of cell proliferation, differentiation, and adhesion. Mutations of the adenomatous polyposis coli (APC) gene elevate nuclear beta-catenin and provoke intestinal tumor formation. We sought to determine whether Wnt signaling is involved in adaptive response to massive small bowel resection (SBR). METHODS: Male Min mice with a mutation of the APC gene and wild-type controls underwent a 50% proximal SBR or sham operation. After 3 days, villus height, crypt depth, and rates of proliferation and apoptosis were recorded in the remnant ileum. RESULTS: After SBR, villus height and enterocyte proliferation were significantly greater in the Min mice. Western blotting demonstrated resection-induced increases in beta-catenin, c-Myc, and E-cadherin after SBR, which was more pronounced in Min mice. CONCLUSIONS: Mutation of the APC gene and augmented Wnt signaling in the intestine results in an enhanced adaptive response to massive SBR. These data, for the first time, implicate an important role for Wnt signaling during the pathogenesis of resection-induced intestinal adaptation.

Animals↗

PubMedDate not supplied

Influence of N-acetylglutamine or glutamine infusion on plasma amino acid concentrations during the early phase of small-bowel adaptation in the dog.

Glutamine is a nonessential neutral amino acid that is widely consumed by the intestinal tract in catabolic states. We have followed up the plasma amino acid profile after extensive small-bowel resection in dogs receiving total parenteral nutrition (TPN) with or without glutamine (GLN) or N-acetylglutamine (aGLN) supplementation. Animals were divided into four groups according to the type of surgery (enterectomy or transection) and nutrition (TPN, TPN with aGLN, or TPN with GLN). Plasma GLN levels decreased in group I (enterectomy and TPN) on day 2 (p = .03) and significantly increased on postoperative days in groups III (enterectomy and TPN with aGLN) and IV (enterectomy and TPN with GLN). A significant increase of plasma GLN was observed in groups III and IV compared with group I on days 6 and 8 (p = .03 and p = .01). Plasma alanine decreased in groups with bowel resection, whereas no change was observed in the control group (transection) and the decrease of plasma alanine was significantly less pronounced in groups III and IV compared with group I. The increase of crypt depth and villous height was more pronounced in groups III and IV. These results suggest that GLN is a required substrate for mucosal growth and function, which could improve the intestinal adaptation encountered after enterectomy.

Alanine↗

PubMed2005

Structural variation in the inner ears of four deep-sea elopomorph fishes.

Deep-sea fishes have evolved in dark or dimly lit environments devoid of the visual cues available to shallow-water species. Because of the limited opportunity for visual scene analysis by deep-sea fishes, it is reasonable to hypothesize that the inner ears of at least some such species may have evolved structural adaptations to enhance hearing capabilities in lieu of vision. As an initial test of this hypothesis, scanning electron microscopy was used to examine the structure of the inner ears of four deep-sea elopomorph species inhabiting different depths: Synaphobranchus kaupii, Synaphobranchus bathybius, Polyacanthonotus challengeri, and Halosauropsis macrochir. The shape of the sensory epithelia and hair cell ciliary bundle orientation of the saccule, lagena, and utricle, the three otolithic organs associated with audition and vestibular function, are described. The saccules of all four species have a common, alternating ciliary bundle orientation pattern. In contrast, the lagena exhibits more interspecific diversity in shape and ciliary bundle orientation, suggesting that it has special adaptations in these species. The macula neglecta, a sensory epithelium of unknown function, is present in all four species.

Adaptation, Physiological↗

PubMedDate not supplied

Household food security among migrant and seasonal latino farmworkers in North Carolina.

OBJECTIVE: Food insecurity is defined as lack of access at all times, due to economic barriers, to enough food for an active and healthy lifestyle. The objective of this study was threefold: to characterize levels of food security, food insecurity, and hunger among migrant and seasonal Latino farmworkers; to assess predictors of food insecurity for this group; and to describe the strategies farmworkers use to cope with food insecurity. METHODS: Adults from 102 farmworker households in North Carolina responded to a survey that used a Spanish-language adaptation of the U.S. Household Food Security Survey Module and questions about sociodemographic characteristics and food behaviors. Twenty-five farmworkers participated in in-depth interviews in which they described their households' food security situation and coping strategies. RESULTS: Forty-eight of the 102 sample households (47.1%) were classified as food insecure, including 10 (9.8%) with moderate hunger and five (4.9%) with severe hunger. Households with children had a significantly higher prevalence of food insecurity than those without children (56.4% vs. 36.2%). Households with children accessed food programs such as the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) that were unavailable to those without children, while those without children were more likely to access food pantries and to consume wild game or fish. Coping strategies included borrowing money, reducing food variety, and adults consuming less food to protect children from hunger. Food insecurity was more than four times as prevalent among farmworker households as among the general U.S. population. CONCLUSION: Policy changes to increase economic resources and access to federal programs are needed to decrease this food insecurity.

Adolescent↗

PubMed1989

The visibility of 350 degrees C black-body radiation by the shrimp Rimicaris exoculata and man.

The eye of the 'eyeless' shrimp Rimicaris exoculata is unusual in having no image-forming optics and a high concentration of rhodopsin. The shrimps swarm around 350 degrees C hydrothermal 'black smoker' vents in the Mid-Atlantic Ridge. There is no other known source of visible light in the shrimp's environment. The spectral sensitivity of rhodopsin is well matched to typical spectra of bioluminescence of organisms found at lesser depths, but other animals detect such emissions without the unusual features of the R. exoculata eye. These two features are most easily understood as an adaptation for the detection of extremely faint sources of light. Physical calculations presented here indicate that the shrimp could see the black-body radiation of the 350 degrees C vents, even though these sources are practically invisible to the human eye. This would be useful to the shrimp as it feeds on sulphide-loving bacteria very near to the vents but must avoid the lethal 350 degrees C vents themselves.

Adaptation, Physiological↗

PubMed1983

Controlled anaesthesia: a clinical evaluation of an approach using patient characteristics identified during uptake.

The performance of a system to control the alveolar concentration of halothane in patients undergoing halothane and nitrous oxide or halothane anaesthesia with controlled ventilation has been evaluated. The method involved the identification and quantification of the uptake characteristics of patients from their early response to the anaesthetic and implements the vaporizer control necessary to achieve and maintain a desired alveolar halothane concentration. Initial targets are based on the concept of MAC, but modifications to the desired alveolar concentration may be effected readily by the anaesthetist at any time during the procedure if evaluation of the normal clinical signs indicates inappropriate depth of anaesthesia. The results obtained during anaesthesia for routine surgery in 80 patients demonstrated that the system was accurate, stable, robust and able to adapt for variability between patients in the uptake of halothane.

Anesthesia, Inhalation↗

PubMed2004

Parents' experiences of asthma: process from chaos to coping.

The aim of the present qualitative study was to describe nine parents' everyday experiences of living with a child suffering from asthma. Data were collected by means of in-depth interviews and phenomenological content analysis. Four main themes emerged: feelings of uncertainty, helplessness and guilt; the need for support and help from healthcare professionals; adaptation to everyday life; and the development of coping strategies. In addition, two subthemes; trying out and seeking information, emerged. Trying out was found to be an important strategy for parents in managing the illness. In encounters with healthcare professionals, parents felt that they were not respected and that their competence was questioned. In conclusion, this study emphasizes the importance of a mutual dialogue between healthcare professionals and parents to enable the parents to develop the competence necessary to care for their child.

Activities of Daily Living↗

PubMed1988

Respiratory effects of cigarette smoke, dust, and histamine in newborn rabbits.

We studied the respiratory effects of cigarette smoke, 5% histamine aerosol, and dust in unanesthetized 1- to 7-day-old rabbits in a body plethysmograph. Cigarette smoke immediately provoked the animal's arousal and irregular breathing. Histamine and dust had no effect in some of the youngest animals. In others, 5-15 s from the onset of the exposure to either of the two stimuli, respiratory rate increased and the depth of breathing decreased. These changes were more pronounced with age. The fact that effects of dust and aerosol lessened with time of exposure showed adaptation to the stimuli. The age dependence of the reflex response was also observed after injection of 50 micrograms of histamine per kilogram into the external jugular vein in anesthetized (50 mg ketamine + 3 mg acepromazine per kg) and tracheostomized rabbits during the 1st wk of life. In 1-day-old animals, a short-lasting excitation was followed by apnea or a prolongation of expiratory phase. Peak amplitude of the diaphragmatic EMG (EMGdi) increased in all animals, but only in the youngest was the EMGdi increase paralleled by an increase in tidal volume. In vagotomized animals or animals pretreated with H1-blocker, histamine never affected timing parameters in animals greater than 1 day old. In the youngest animals, respiratory depression due to histamine was not abolished after vagotomy or promethazine. The results imply that inputs from the upper airways and the rapidly adapting pulmonary mechanoreceptors exert their effects on the pattern of breathing immediately after birth in rabbits. The importance of those inputs increases with maturation.

Aerosols↗

PubMedDate not supplied

Dermal capillary clearance: physiology and modeling.

Substances applied to the skin surface may permeate deeper tissue layers and pass into the body's systemic circulation by entering blood or lymphatic vessels in the dermis. The purpose of this review is an in-depth analysis of the dermal clearance/exchange process and its constituents: transport through the interstitium, permeability of the microvascular barrier and removal via the circulation. We adapt an 'engineering' viewpoint with emphasis on quantifying the dermal microcirculatory physiology, providing the theoretical framework for the physics of key transport processes and reviewing the available computational clearance models in a comparative manner. Selected experimental data which may serve as valuable input to modeling attempts are also reported.

Administration, Cutaneous↗