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PubMed1988

The cellular basis of Wolff's law. Transduction of physical stimuli to skeletal adaptation.

The cellular milieu responsible for skeletal homeostasis is extremely complex, comprised of many elements, and serves to accomplish both structural and metabolic responsibilities. From one perspective, it is the interactions of the cells loosely grouped as "osteoregulatory" which must retain many of the mineral and metabolic levels of the body. From another view, the coordinated formation and resorption of mineralized tissues, relegated by this same population of cells, is predominantly responsible for achieving and retaining the structural integrity of the skeleton. Unfortunately, the predominant focus of much research is asympathetic to the multifaceted role of the skeleton; it is perceived either as a mineral reservoir or as a structural entity. The skeleton, however, is both of these things. It is not until we acknowledge the dual responsibility of bone that we will be able to understand what parameters, systemic or local, control its regulation. Considered within the context of a three-dimensional movie, with metabolic roles cast in red and structural ones in green, neither the impact nor depth of the film can be appreciated until viewed through the glasses which consider the intricate balance between both the mechanical and mineral dimensions.

Adaptation, Physiological↗

PubMed2004

Prospective study of men's psychological and decision-related adjustment after treatment for localized prostate cancer.

OBJECTIVES: To undertake a prospective longitudinal study to assess psychological and decision-related distress after the diagnosis of localized prostate cancer. METHODS: A total of 111 men (93% response rate) with localized prostate cancer were recruited from outpatient urology clinics and urologists' private practices. More than one half (56%) elected to undergo radical prostatectomy, 19% underwent external beam radiotherapy, and 25% chose watchful waiting. Men completed self-report measures before treatment and 2 and 12 months after treatment. The measures used included the University of California, Los Angeles, Prostate Cancer Index, International Prostate Symptom Score, Impact of Events Scale, Constructed Meaning Scale, Satisfaction with Life Scale, Health Care Orientation subscale, and Decisional Conflict Scale. RESULTS: No statistically significant differences were found by medical treatment group in the psychological and decision-related adjustment at baseline or with time. Men who were undecided about their treatment choice had greater decisional conflict and a more negative healthcare orientation, but were not more psychologically distressed, compared with men who had decided. At diagnosis, 63% of men had high decision-related distress, and this persisted for 42% of men 12 months after treatment, despite high satisfaction with their treatment choice. At diagnosis, low-to-moderate psychological distress was most common, with distress decreasing after treatment. The overall quality of life was similar to community norms. CONCLUSIONS: The results of our study indicated that men who were undecided about what treatment to receive experienced greater decision-related distress. The final treatment choice was not related to psychological distress about prostate cancer. Psychological and decision-related distress decreased with time, independent of treatment modality. Interventions should target decision-related distress for all men and in-depth psychological support for those who experience ongoing difficulties.

Adaptation, Psychological↗

PubMed2006

When a partner dies: lesbian widows.

Death of a life partner and the subsequent bereavement are profound experiences for an individual. By far, the majority of bereavement research reported is focused on heterosexual couples, primarily married and often in the later years of life. The purpose of this study was to describe the bereavement experiences of lesbians whose life partners have died. The study used a descriptive, qualitative design informed by feminist scholarship and phenomenology to access the depth of personal experiences, as well as internally interpreted meanings of those experiences, among lesbian widows.

Adaptation, Psychological↗

PubMed2005

Plant ecology of Australia's tropical floodplain wetlands: a review.

AIMS: Despite the biodiversity values of the freshwater floodplains of northern Australia being widely recognized, there has not been a concomitant investment in developing the extent of knowledge of the basic functions and ecological processes that underpin the ecological character of these habitats. This review addresses the extent of our knowledge on the plant ecology of these wetlands and covers: the relationships between the climate and the hydrological regime on the floodplain; the vegetation patterns, succession and adaptation; and primary production. SCOPE: Information is available on the seasonal, but less regularly on the inter-annual, dynamics of the macrophytic vegetation and its evident inter-relationship with the extent, depth and duration of inundation by seasonal flooding. The available scientifically collected information on plant distribution and relationship with the water regime could be complemented by more attention to traditional knowledge. The productivity of the vegetation is high-the dominant wetland grass species have an annual dry weight production of 0.5-2.1 kg m-2 and the surrounding riparian (Melaleuca) trees contribute litterfall of 0.7-1.5 kg (dry weight) m-2 year-1, approximately 70% due to leaf-fall. The availability of dissolved oxygen in the water is known to vary diurnally and seasonally, at least in some habitats. The importance of seasonal differences in the availability of dissolved oxygen for the growth of micro- and macrophytic vegetation has not been investigated. The seasonal distribution and growth of plant species on a few floodplains have been investigated, and maps at scales of 1:10,000 to 1:100,000 are available for these. However, only on a few occasions have longer term analyses been conducted and long-term changes in the vegetation measured and assessed. Species lists and categorization of growth strategies and forms are available and provide a basis for further ecological investigation. CONCLUSIONS: Despite the large investment in managing the many pressures that have degraded the ecological character of these highly valued wetlands, the fundamental ecological processes that underpin the biodiversity values have not received the same level of attention. Further information on plant growth and the environmental factors that drive seasonal and annual changes in vegetation distribution and productivity is required to assist managers in attending to changes due to increasing invasive species and changes in fire regimes.

Australia↗

PubMed2003

Public participation in health planning and priority setting at the district level in Uganda.

OBJECTIVE: To explore the experiences of the public and leaders with participatory planning and priority setting in health, in a decentralized district in Uganda. METHODOLOGY: An exploratory qualitative approach, involving in-depth interviews with health planners at the national, district and community levels (n = 12), and five group discussions at community level with women (two groups), men, youths and adolescents (n = 51). The analysis adapted some principles from grounded theory. The five levels of the participation framework by Rifkin (1991) were used to assess the actual level of participation in the study population. RESULTS: Uganda has established structures for participatory planning. Within this context, district level respondents reported to have gained decision-making powers, but were concerned about the degree of financial independence they had. The national level respondents were concerned about the capacity of the districts to absorb their new roles. Actual involvement of the public in priority setting and poor communication between the different levels of the decentralization system, despite the existing structures, were additional concerns. Public participation is mainly through representatives. Majority participation is mainly at health benefits and programme activity levels. Decision-making, monitoring and evaluation, and implementation are still dominated by the locally elected leaders due to reported economic, social and cultural barriers that hinder the participation of the rest of the public.

Community Health Planning↗

PubMed1997

Techniques to accelerate dynamic psychotherapy.

The techniques described above outline specific ways to deepen the patient's affective experience within an emotionally close therapeutic relationship. When effective, they all enhance the patient/therapist bond, raise self-esteem, reduce defensiveness and anxiety, and facilitate emotional healing. Psychodynamic treatment, long or short, is a complex process uniquely constructed by each therapist/patient pair. AEDP strategies are not intended as recipes for treatment. Good dynamic work depends on the therapist's ability to grasp the patient's capacities and limitations, understand relational dynamics, and interact with the patient in an empathically attuned, emotionally receptive, and flexible way. In that context, these strategies can be helpful tools to facilitate and accelerate the process. The choices made by AEDP--privileging adaptive strivings over defensive reactions, the stance of emotional engagement rather than neutrality and abstinence, the focus on health and change over pathology and stasis--are informed by traditional STDP aims to maximize depth, effectiveness, and efficiency. AEDP's contribution is a set of techniques relying on a response repertoire that is available to a wide range of therapists. Therapists can use these techniques to be more effective while simultaneously retaining the experience of speaking with patients in an authentic voice.

Affect↗

PubMed2005

[Treatment of bedsores--combination of therapies depended the experimental design method].

The treatment of bedsores is a particular problem in geriatric medicine. We selected standard drugs that may be effective for the decubitus ulcer, and investigated combination therapy to develop efficient treatment The subjects were 16 patients in whom the grade of the bedsore was evaluated as II to IV according to the Shea's depth classification. Treatment was performed while all patients were on air mats. We selected drugs and treatment methods based on the previously established experimental design of Taguchi. Based on this, we created and adapted 16 different component combination treatment programs in accordance with the L16 rectangular cross table. The following component factors were adopted: A: types of covering substances on the wound surface (Elase ointment, isodine sugar, isodine gel solcoseryl ointment); B: Isalopan powder; C: Spray of 10 ml physiological saline containing 500 microg of prostaglandin (concentration 0.005%); D: daily number of treatments; and F: presence or absence of tapping. We serially measured the wound surface area as an index of the speed of wound healing, and measured the interval (day) until the area decreased to one half of the original size (T1/2, half life). We analyzed data on one combination treatment each in 16 patients. Analysis of variance of the above factors showed significant F values for factors A, B, D and F. The contribution rates for factors A, B, D and F were 37.84%, 8.47%, 14.98% and 13.81%, respectively. The error term (e) was 16.37%. Optimal results were seen in the groups in which solcoseryl ointment had been applied twice a day. In this study, prostaglandin, which had been anticipated to be effective, did not show any effects. The error term (e) suggests the presence of other healing factors including individual differences. Concerning this point, it well be necessary to examine a larger number of patients in the future. With ointment treatment alone, without using an air mat, it was confirmed that bedsore area reduction was extremely unstable. Decompression of the affected part may be a basic prevention factor and essential treatment of bedsores.

Actihaemyl↗

PubMed1992

Maternal-infant health beliefs and infant feeding practices: the perception and experience of immigrant Vietnamese women in Sydney.

The purpose of this study was to describe and compare the health beliefs and infant feeding behaviour of Vietnamese women before and after immigration to Sydney. Findings from 20 in-depth face to face interviews conducted in the women's homes revealed that infant feeding behaviour was shaped by the women's beliefs about maternal, infant and family health. Through a process of adaptation these health beliefs had been modified under the influence of the social, cultural, and economic environment of the host country. The findings offer a greater understanding of Vietnamese culture and infant feeding behaviour on which to base nursing intervention programs to promote breast feeding.

Acculturation↗

PubMed1999

The effects of saline-induced edema in the human nasal mucosa on laser Doppler flowmetry.

The nasal mucosa on the anteromedial surface of the inferior turbinate was studied with laser Doppler flowmetry in ten patients who were under general anaesthesia. A specially designed adapter was used, which held an injection needle with a diameter of 0.4 mm in a fixed position to the tip of the probe. The tip of the needle was inserted to a depth of 0.7 mm below the surface of the mucosa, while the tip of the probe was held at a distance of 0.3 mm from the mucosa. The laser Doppler parameters of perfusion, concentration of moving blood cells (CMBC) and velocity were recorded before and after the injection of 0.8 ml saline, thus inducing an experimental edema. After the injection no change in perfusion was detected but CMBC decreased and velocity increased. The findings agreed with the view that an increase in mucosal edema would reduce CMBC. When studying unanaesthesised subjects we normally use both rhinostereometry and laser Doppler flowmetry. It is then possible to measure the degree of mucosal congestion and micro circulation simultaneously, thus permitting study of the effects of a change in interstitial fluid content on mucosal congestion.

Edema↗

PubMed2006

Dosimetric model for locoregional treatments of brain tumors with 90Y-conjugates: clinical application with 90Y-DOTATOC.

UNLABELLED: Locoregional (LR) administration of (90)Y-conjugates after surgical debulking is a promising therapeutic option of gliomas. Dosimetry is highly recommended, as patient-specific parameters influence the absorbed dose to target and normal tissues. After tumor resection, the absorbed dose must be carefully evaluated in the rim of tissue surrounding the resected area. The aim of this study was to calculate and provide the S values, according to the MIRD concept, for dosimetry of LR brain treatments with several (90)Y-labeled compounds. The S values thus obtained have been clinically applied in 12 patients treated with (90)Y-labeled [DOTA(0),D-Phe(1),Tyr(3)]octreotide ((90)Y-DOTATOC). METHODS: An anthropomorphic model for Monte Carlo simulations was developed to evaluate absorbed doses in brain-adjacent tissue (BAT) and in normal brain. To adapt the model to single patients, S values were evaluated taking into account (i) different surgical resection cavity (SRC) volumes, (ii) different percentages of conjugate binding to the cavity wall, and (iii) different depths of percolation of the conjugate trough the cavity wall. BAT was divided into 1-mm-thick consecutive adjacent shells to evaluate the dose distribution around the cavity. Corresponding S values were obtained to allow dosimetric evaluation in brain LR therapy with (90)Y-conjugates. In the clinical treatments, 0.4-1.1 GBq of (90)Y-DOTATOC were injected into the SRC via an appropriate catheter. The activity in the SRC was assumed to be the difference between the total injected activity and the activity in the blood plus the activity cumulatively eliminated with the urine. RESULTS: Assuming no diffusion, with a mean residence time in SRC of 60 +/- 8 h, absorbed doses to shell II were 0.25 and 0.03 Gy/MBq for SRC volumes of 7.2 and 65.4 mL, respectively. Assuming a slight diffusion of 1 mm with a 7.2-mL SRC, absorbed dose to shells I, II, and VI were consistently different: 5.32, 2.53, and 0.12 Gy/MBq, respectively. Mean doses to normal brain, red marrow, bladder wall, and total body were 0.015, 0.03, 1.22, and 0.006 MGy/MBq. CONCLUSION: The model proved to be suitable for the dosimetry of several LR therapies with (90)Y-conjugates. According to our results, LR treatment with (90)Y-DOTATOC can safely deliver very high doses to target tissue, sparing normal organs including brain.

Adult↗

PubMed1997

The sensitivity of the chick eye to refractive defocus.

The chick is commonly used as an animal model for human myopia and emmetropization. However one criticism of this model has been the very large refractive errors that are usually induced, either by visual deprivation or through the use of lenses to first impose focussing errors. This study sought to determine the threshold for compensatory responses to imposed defocus. We observed compensation in chick eyes fitted at hatching with +1D and -1D lenses (one over each eye). Consistent with the 2D interocular difference in refraction imposed, an average of 2.13D (SD 1.0D) of anisometropia and a 0.09 mm (SD 0.05 mm) interocular difference in vitreous chamber depth were recorded after five days of lens wear. The 1 D focusing errors imposed on individual eyes are not much greater in magnitude than the estimated depth of focus of the chick eye. The significance of these results for emmetropization are discussed.

Adaptation, Physiological↗

PubMed1978

Contributions of bile and pancreatic juice to cell proliferation in ileal mucosa.

To determine the relative contributions of bile and pancreatic juice to adaptive intestinal hyperplasia, cell proliferation in rat ileal mucosa was studied after supplying bile alone or the combined pancreaticobiliary effluent direct to mid-small bowel. Bile was routed through the choledochus cannulated above the pancreas. Pancreaticobiliary secretions were diverted through a transposed duodenal segment containing the papilla. Diversion of bile into the mid-bowel with and without pancreatic juice caused similar increases in ileal ribonucleic acid (RNA) (16% to 50%) and deoxyribonucleic acid (DNA) (22% to 41%) contents at both 48 hours and 1 week after operation. Specific activity of DNA after injection of tritiated thymidine was greatest after diversion of the combined effluent. After 1 month nucleic acid contents in the upper ileum after pancreaticobiliary diversion were 37% to 59% higher than after transection or biliary diversion (P less than 0.005). Likewise, after biliary diversion villous height and crypt depth were increased only at 1 week, but after diversion of both secretions increases were found at 1 week and 1 month. High luminal concentrations of bile cause transient cell proliferation in ileal mucosa, but the additional presence of pancreatic juice prolongs this adaptive response.

Adaptation, Physiological↗

PubMed1981

Prolactin and the small intestine. Effect of hyperprolactinaemia on mucosal structure in the rat.

To study the mechanism for the adaptive mucosal hyperplasia which occurs independent of luminal nutrition and pancreatico-biliary secretions in isolated Thiry-Vella segments of intestine from lactating rats, and to examine the effects of prolactin on small bowel mucosal structure in the rat, we used two models of experimental hyperprolactinaemia and compared quantitative histology and several markers of mucosal mass in jejunum and ileum from control rats and from test and lactating animals. Hyperprolactinaemia, induced by perphenazine injections (5 mg/kg/day for two or seven weeks) or transplantation of four pituitary glands from donor animals to beneath the renal capsule in the recipient, was confirmed by radioimmunoassay. Proof of its biological activity was obtained by weighing the mammary pads and by demonstrating true breast hyperplasia on histological section. Median serum prolactin levels increased from 50 ng/ml in the controls to 570 ng/ml in the perphenazine treated animals and to 600 ng/ml in the pituitary transplanted rats-levels comparable with those seen in lactation (870 ng/ml). In the lactating rats, there was striking mucosal hyperplasia of both jejunum and ileum but, despite the hyperprolactinaemia, there were no such changes in villus height, crypt depth, or in mucosal wet weight, protein, or DNA/unit length intestine in the perphenazine-injected or pituitary-transplanted animals. We conclude that prolactin is not atrophic to the intestine in rats and that hyperprolactinaemia cannot explain the intestinal adaptive changes of lactation.

Animals↗

PubMed2004

Synaptic circuitry mediating light-evoked signals in dark-adapted mouse retina.

Light-evoked excitatory cation current (DeltaIC) and inhibitory chloride current (DeltaICl) of rod and cone bipolar cells and AII amacrine cells (AIIACs) were recorded from slices of dark-adapted mouse retinas, and alpha ganglion cells were recorded from flatmounts of dark-adapted mouse retinas. The cell morphology was revealed by Lucifer yellow fluorescence with a confocal microscope. DeltaIC of all rod depolarizing bipolar cells (DBCRs) exhibited similar high sensitivity to 500 nm light, but two patterns of DeltaICl were observed with slightly different axon morphologies. At least two types of cone depolarizing bipolar cells (DBCCs) were identified: one with axon terminals ramified in 70-85% of IPL depth and DBCR-like DeltaIC sensitivity, and the other with axon terminals ramified in 55-75% of IPL depth and much lower DeltaIC sensitivity. The relative rod/cone inputs to DBCs and AIIACs were analyzed by comparing the DeltaIC and DeltaICl thresholds and dynamic ranges with the corresponding values of rods and cones. On average, the sensitivity of a DBCR to the 500 nm light is about 20 times higher than that of a rod. The sensitivity of an AIIAC is more than 1000 times higher than that of a rod, suggesting that AIIAC responses are pooled through a coupled network of about 40 AIIACs. Interactions of rod and cone signals in dark-adapted mouse retinas appear asymmetrical: rod signals spread into the cone system more efficiently than cone signals into the rod system. The mouse synaptic circuitry allows small rod signals to be highly amplified and effectively transmitted to the cone system via rod/cone and AIIAC/DBCC coupling. Three types of alpha ganglion cells (alphaGCs) were identified. (1) ONGCs exhibits no spike activity in darkness, increased spikes in light, sustained inward DeltaIC, sustained outward DeltaICl of varying amplitude, and large soma (20-25 microm in diameter) with an alpha-cell-like dendritic field about 180-350 microm stratifying near 70% of the IPL depth. (2) Transient OFFalphaGCs (tOFFalphaGCs) exhibit no spike activity in darkness, transient increased spikes at light offset, small sustained outward DeltaIC in light, a large transient inward DeltaIC at light offset, a sustained outward DeltaICl, and a morphology similar to the ONalphaGCs except for that their dendrites stratified near 30% of the IPL depth. (3) Sustained OFFalpha GCs (sOFFalphaGCs) exhibit maintained spike activity of 5-10 Hz in darkness, sustained decrease of spikes in light, sustained outward DeltaIC, sustained outward DeltaICl, and a morphology similar to the tOFFalphaGCs. By comparing the response thresholds and dynamic ranges of alphaGCs with those of the pre-ganglion cells, our data suggest that the light responses of each type of alphaGCs are mediated by different sets of bipolar cells and amacrine cells.

Amacrine Cells↗

PubMed2005

Newly diagnosed childhood diabetes: a psychosocial transition for parents?

AIM: This paper reports a study to gain a new theoretical understanding of parental grief responses and the process of adaptation to a diagnosis of childhood diabetes. BACKGROUND: A diagnosis of childhood (type 1) diabetes is an anxious and distressing event for the whole family. Little is known about the experience of parents of newly diagnosed children as they cope with and adapt to their new situation. Parkes' Theory of Psychosocial Transition proposes that life-change events, or 'psychosocial transitions', require people to undertake a major revision of their assumptions about the world. The relevance of this theory to adjusting to a diagnosis of childhood diabetes has not been explored. METHOD: Forty audio taped in-depth interviews were undertaken with 38 parents of 20 newly-diagnosed children. The data were subsequently examined using the framework of the Theory of Psychosocial Transition. FINDINGS: Before diagnosis, most parents associated their child's symptoms with normal childhood illnesses. The unexpectedness and speed of the diagnosis left all parents ill-prepared to deal with the situation. Their world suddenly changed, leaving them insecure and uncertain about the future. Diabetes intruded emotionally and practically upon all of their lives. Parents successfully adjusted and adapted their lives and rebuilt a new model of the world to accommodate their child's diabetes. However, this dynamic process has no guaranteed endpoint for parents. CONCLUSIONS: A diagnosis of childhood diabetes leads to a psychosocial transition for parents. The concept of transition provides a logical explanation of parents' responses to loss, and allows increased understanding of the grieving and adaptation processes experienced by parents of children diagnosed with a chronic condition such as diabetes. This knowledge should help health care professionals to assist parents in the period of transition.

Adaptation, Psychological↗

PubMed1990

Mathematical models of the spatial distribution of retinal oxygen tension and consumption, including changes upon illumination.

To better understand oxygen utilization by the retina, a mathematical model of oxygen diffusion and consumption in the cat outer, avascular retina was developed by analyzing previously recorded profiles of oxygen tension (PO2) as a function of retinal depth. Simple diffusion modelling of the oxygen distribution through the outer retina is possible because the PO2 depends only on diffusion from the choroidal and retinal circulations and on consumption within the tissue. Several different models were evaluated in order to determine the best one from the standpoints of their ability to represent the data and to agree with physiological reality. For the steady state one-dimensional diffusion model adopted (the special three-layer diffusion model), oxygen consumption was constant through the middle layer and zero in the layers near the choroid and near the inner retina. On the average, the oxygen consuming layer, as found by nonlinear regression for each profile, extended from about 75% to 85% of the retinal depth from the vitreous. This is a narrow band through the mid-region of the photoreceptors. Oxygen consumption of the entire avascular retina, determined from fitting eight PO2 profiles measured in light-adapted retinas, averaged 2.7 ml O2(STP)/(100 g tissue.min), while the value determined from fitting thirty-two PO2 profiles measured in dark-adapted retinas averaged 4.4 ml O2(STP)/(100 g tissue.min). Consumption in the light was thus only 60% of that in the dark. This suggests that the outer retina is at greater risk of hypoxic injury in the dark than in the light, a finding of considerable clinical significance.

Animals↗

PubMed1996

In vivo microdialysis in the rat: low cost and low labor construction of a small diameter, removable, concentric-style microdialysis probe system.

A method for construction of a serviceable and low cost intracerebral microdialysis system is presented. The system includes a probe and its supporting components. The probe is of the concentric design. The supporting components are an implantable guide cannula, a tether, and a swivel. After minimal training, workers can make many probes of consistent performance characteristics in a short time. Because all of the parts are commercially produced, users may obtain custom-made components which are finished with factory precision and accuracy. The user may readily vary probe characteristics such as depth of implant and size of active portion, so that different types of dialysis may be performed in different brain regions. The available choices in tether and swivel configurations make this microdialysis system readily adaptable to diverse testing environments. Excluding labor and startup costs, the costs, the cost per probe is approximately $11.00 (US). Taken together, the system provides a flexible, low cost means for performing in vivo microdialysis in freely moving rats.

Animals↗

PubMed2002

Extended depth-of-focus imaging of chlorophyll fluorescence from intact leaves.

Imaging dynamic changes in chlorophyll a fluorescence provides a valuable means with which to examine localised changes in photosynthetic function. Microscope-based systems provide excellent spatial resolution which allows the response of individual cells to be measured. However, such systems have a restricted depth of focus and, as leaves are inherently uneven, only a small proportion of each image at any given focal plane is in focus. In this report we describe the development of algorithms, specifically adapted for imaging chlorophyll fluorescence and photosynthetic function in living plant cells, which allow extended-focus images to be reconstructed from images taken in different focal planes. We describe how these procedures can be used to reconstruct images of chlorophyll fluorescence and calculated photosynthetic parameters, as well as producing a map of leaf topology. The robustness of this procedure is demonstrated using leaves from a number of different plant species.

Journal Article↗