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PubMed1970

Rod-cone independence for sensitizing interaction in the human retina.

1. Illumination of a retinal area adjoining a tested area can cause either desensitization or sensitization through lateral interaction, depending on whether the distance separating the illuminated and tested areas is small or large. This interaction occurs both in the rod and the cone mechanisms of the retina when each is tested separately by selection of appropriate adapting and testing stimuli.2. In the mixed rod/cone region of the near periphery of the human retina the spatial parameters of interaction within the rod and cone systems were different when mapped out by using only one kind of adapting stimulus and sampling the excitatory state of the rod and cone systems by different probing stimuli.3. Sensitizing interaction signals generated by the rod system are incapable of causing sensitization of the cone system.

Adaptation, Ocular↗
PubMed2004

Maternal adaptation to a child's epilepsy.

Mothers of children with epilepsy are at risk for problems in adapting to their child's condition; however, factors associated with maternal adaptation to a child's epilepsy have not been well articulated. The purpose of this study was to investigate the associations among maternal and child characteristics, maternal beliefs, and maternal adaptation outcomes. A conceptual model was formulated based on the literature. Maternal beliefs were proposed to mediate the relationships between maternal and child characteristics and maternal adaptation outcomes. A sample of 156 maternal-child dyads provided data via structured telephone interviews. Multiple regression analysis was used to test for additive and mediated relationships. Mediation was not supported statistically. Child behavior problems, maternal satisfaction with family, and maternal learned helplessness had the strongest associations with maternal outcomes, suggesting that maternal adaptation to a child's epilepsy is complex and includes multiple factors in addition to the child's seizure condition.

Adaptation, Psychological↗
PubMed2001

Validation of an analytical procedure for the determination of the fluoroquinolone ofloxacin in chicken tissues.

A novel analytical procedure was developed for the determination of the fluoroquinolone ofloxacin in chicken kidney, liver, muscle and fat plus skin tissues. The procedure involved a preliminary extraction with 0.15 M HCl followed by solid-phase extraction clean-up. The purification step was performed using a polymeric sorbent coated cartridge. Ofloxacin was analyzed by reversed-phase HPLC using UV detection at 295 nm. The mobile phase used was water-acetonitrile-triethylamine (83:14:0.45, v/v, pH 2.30). The use of triethylamine and the acidic pH modulated the retention of ofloxacin and avoided chemical tailing. The amine modifier and acetonitrile content of the mobile phase were optimized to provide the best selectivity. A flow-rate of 1 ml/min was used and ofloxacin eluted at approximately 5.1 min. HPLC analysis of the tissue samples was performed in 12 min. The procedure was validated according to the International Conference on Harmonisation guidelines across the concentration ranges (100 microg/kg-1.7 mg/kg for kidney and liver tissues and 50 microg/kg-1.0 mg/kg for muscle and fat plus skin tissues). The linearity, the intra- and inter-day accuracies and precisions were determined. The limits of quantification were 50 microg/kg for muscle and fat plus skin tissues and 100 microg/kg for liver and kidney tissues. The procedure was specific and the accuracy values were lower than 20% at the limit of quantitation of spiked samples. The recovery values ranged from 80 to 100%. The limits of detection were established at 60 microg/kg for liver and kidney tissues and at 25 microg/kg for muscle and fat plus skin tissues. Finally, ofloxacin was found to be stable in acidic conditions. The developed procedure is simple, sensitive, accurate and adapted to routine sample analyses such as those carried out for residue depletion studies.

Animals↗
PubMed1989

[Coping with disease from the psychosomatic-psychotherapeutic viewpoint exemplified by pancreatectomized patients].

In the past few years psychosomatic medicine, apart from investigating the psychosocial sources of bodily disorders, has begun to focus also on the opposite side of the problem, the question of how people experience illness and cope with it. This "somatopsychic" view can be regarded as a supplement to the so far prevailing psychosomatic perspective and its approach. The present study describes and analyzes various strategies of coping with illness as observed in a group of pancreatectomized patients, a group of patients which has not been investigated before in this field of research. Based upon the experience of long-term psychotherapeutic care, the study differentiates between the more problematic and the more beneficial forms of coping, and empirically verifies their prevalence and adaptivity in a sample of pancreatectomized patients, not selected with regard to the extent of care needed. The findings are discussed from the methodological and the psychosomatic-psychotherapeutic point of view.

Adaptation, Psychological↗
PubMed1988

Evoked potential estimates of the time course of adaptation and recovery to counterphase gratings.

Scalp-recorded evoked potentials (VEP) were sequentially sampled in humans during adaptation to and recovery from prolonged viewing of counterphase sinusoidal grating targets. The sum of the power at the first and second harmonics of the Fourier-transformed VEP components was found to decrease during adaptation and increase during recovery. Time constants (T) for the adaptation and recovery processes as estimated from exponential functions ranged from 2.9 to 19 sec, varying non-monotonically with the spatial frequency and contrast of the stimulus. The observed T values are shorter than those reported in psychophysical studies of adaptation but overlap estimates derived from single cell studies. An unexpected finding was the occurrence of a 3-6 sec delay in the appearance of the maximum VEP response after the onset of the adaptation stimulus. The delay occurred in all subjects and at all spatial frequencies when moderate to high adapting contrasts (e.g. greater than 0.2) were used. The data support a feature-selective, multi-channel lateral inhibitory model of spatial vision and suggest the presence of tonic inhibition between the channels.

Adaptation, Ocular↗
PubMed1999

A procedure for generating bootstrap samples for the validation of nonlinear mixed-effects population models.

A method is presented for automated preparation of bootstrap data samples and their presentation to NONMEM for use in the validation of population pharmacokinetic or pharmacodynamic models, which have been developed with relatively small numbers of subjects. The bootstrap sampling procedure involves the use of an MS-DOS batch file and a script file for use with the public-domain text processing program, AWK, which is a single EXE file (48k in size for the version used in this report). A UNIX version of AWK is also available and UNIX users can adapt the process to their needs. Its use obviates the need for expensive, high-end statistical packages and associated script files written using in-built programming languages. The method can easily be adapted to bootstrap sampling requirements in other biomedical modelling applications.

Computer Simulation↗
PubMed2006

Structured Assessment of Correctional Adaptation (SACA): a measure of the impact of incarceration on the mentally ill in a therapeutic setting.

Clinicians have observed that psychiatric patients with correctional histories evidence attitudes and behaviors that seem adaptive in penal environments but are maladaptive in mental health settings. This study sought to assess the reliability and concurrent validity of a rating scale designed to measure correctional adaptation using a sample of 64 patients from a state psychiatric hospital. Scale ratings were obtained through structured interviews, whereas predictor variables were gleaned from chart review and self-report. The scale demonstrated good interrater reliability (ICC = .83) and acceptable internal consistency (alpha= .67). Of the variables evaluated, two were significantly correlated with Structured Assessment of Correctional Adaptation (SACA) total scores, total months sentenced to prison or jail (r = .26), and frequency of disciplinary tickets while in prison or jail (r = .31). Stepwise regression analyses revealed only the latter variable significantly predicted SACA score (R = .31), F(1, 58) = 6.27, p < .05. Clinical implications of these findings, the scale, and the construct of correctional adaptation are discussed.

Adaptation, Psychological↗
PubMed1994

A prospective study of family environments of children hospitalized for nonorganic failure-to-thrive.

Family functioning of nonorganic failure-to-thrive (NOFT) infants was compared with that of physically healthy, normally growing infants of similar socioeconomic status shortly after the time of the diagnosis of this condition (average age of 5 months) and again at 4 years of age. Families of NOFT infants demonstrated less adaptive relationships than did comparison-group infants, as measured by the Family Relationships Inventory (FRI) at both time points, but a comparable number of changes in residence and constellation on follow-up. Contrary to prediction, the quality of family relationships at point of diagnosis did not predict subsequent family relationships, residence, or constellation changes in the NOFT sample. However, more adaptive family relationships in the comparison group at study entry predicted fewer residence and constellation changes and more cohesive relationships 3 years later. The impact of significant discontinuities in family functioning and status should be considered in research and in clinical interventions with NOFT children.

Child, Preschool↗
PubMed1991

Comparison of urea treatment with established methods of sorghum grain preservation and processing on site and extent of starch digestion by cattle.

To determine the effect of dry (D); reconstituted and ensiled (R); reconstituted and acid-treated (A); and urea-treated, high-moisture (U) sorghum grain on starch digestibility, four Angus x Hereford steers (means BW = 350 kg) with duodenal and ileal cannulas were used in a 4 x 4 Latin square design. Diets consisting of 69% ground sorghum grain were fed every 2 h in equal portions (8.2 kg/d). Diets averaged 46.5% starch and 12% CP, except for U, which averaged 14% CP due to urea treatment. Ytterbium attached to sorghum was used as a particulate marker. Duodenal, ileal, and fecal samples were taken 1 h postfeeding after a 14-d adaption to diets. Whole samples were analyzed. Preduodenal starch digestion (%) was 89, 83, 76, and 70, and starch digestion over the total tract was 99, 97, 95 and 91 for R, U, A, and D, respectively. Starch digestion proximal to each site (duodenum and ileum) was enhanced (P less than .05) by R and U compared with D. Within the small intestine, there was a linear relationship (P less than .003) between starch digestion and daily starch supply. However, digestibility of starch in the small intestine (mean = 45%) was not different among diets. Apparent digestibility of starch in the large intestine was not significantly different from digestibility in the small intestine. Urea-treated sorghum grain was equivalent to reconstituted, ensiled sorghum in digestion characteristics and was superior to dry sorghum.

Animal Feed↗
PubMed1992

A role supplementation group pilot study: a nursing therapy for potential parental caregivers.

This pilot study addressed the question: Will transition support for mid-life women during role transition into the caregiver or care manager role for their parents lead to role adaptation? A systematic sample of 30 women between the ages of 30 and 60 was drawn from a pool of employees of a large health science center in the Southwest; their mothers were also asked to volunteer as research subjects. A before-after group with random assignment design was used to determine the effects of a CNS-led support group on role adaptation of mid-life women during role transition. Role adaptation was measured by correlating the scores of mother and daughter pairs on the Brackley Concerns of Aging Scale. The level of depression as an indicator of role insufficiency was determined by score on Zung's Self-Rating Depression Scale. The independent variables were social support and the CNS-led group. A two-way analysis of covariance was calculated to test each hypothesis. Hypothesis 1, which predicted a decrease in role insufficiency following transitional nursing support, was rejected. Support was found for Hypothesis 2, which specified an increase in role adaptation following transitional nursing support. Alpha was set at p less than or equal to 0.05.

Adaptation, Psychological↗
PubMed2001

[Cytopathology--current trends].

Modern imaging techniques help to detect minute tumours, even in remote locations of the body. This increases the demand to sample cellular material by minimal invasive procedures, such as fine needle aspiration (FNA). For optimal treatment, tumour cells should be characterized for prognostically relevant features. Primary and metastatic neoplasms, and individual disseminated cells of solid tumours are targets for FNA and exfoliative cytology. Recognition and typing of tumour cells is aided by immunochemistry and PCR based molecular studies. Especially immunostaining requires laboratory procedures adapted to cytology samples. Screening for precancerous lesions, highly successful in cervical cancer prevention, extends into areas such as bladder and lung cancer in selected patient groups. Cell image analysis, especially for DNA ploidy, and chromosomal FISH of interphase cells can have predictive value enhancing the information derived from the purely morphologic assessment. Prognostic tumour cell markers are studied using immunochemistry and PCR on cytological material. Cytology has to foster translational research and test the results from molecular cytogenetics, including comparative genomic hybridisation (CGH) and cDNA microarray techniques on dissociated solid tumour cells. Newly identified genetic abnormalities can be evaluated for their functional relevance and may correlate with distinct structural alterations of the tumour cells. Proper training, dedication to diagnostic cytologic work and molecular studies, and sufficient staffing will enable cytology to get the most for the patient out of limited cell material. This approach helps to distinguish genetically defined tumour subtypes by recognizing properties of the cell gestalt.

Biopsy, Needle↗
PubMed2005

Optimal two-stage randomized phase II clinical trials.

Randomized phase II clinical trials can be an efficient means of evaluating several potential new treatments prior to a comparative phase III clinical trial. However, selection designs do not allow for an assessment of minimal efficacy, nor do they allow early closing of a study arm for lack of efficacy, and so are only appropriate when all arms have met minimal efficacy requirements. Classic two-stage hypothesis testing based designs such as a Simon two-stage optimal design can satisfy these requirements, when used in parallel for the multiple treatment arms. However, these can be inefficient and impractical in terms of the maximum planned sample size required for such a study. This article proposes a two-stage randomized phase II clinical trial, where the sample size is adaptive at the second stage to the number of treatment arms passing through the first stage. The study design relies on optimality criteria, which are analogous to those used by Simon for single-arm studies. The proposed design maintains similar operating characteristics to a strategy of using multiple single-arm studies, in most situations of primary interest. Furthermore, it generally has smaller actual sample size when most of the treatments are effective than using multiple single-arm studies, leading to substantial efficiencies in terms of maximum planned sample size.

Clinical Trials, Phase II as Topic↗
PubMedDate not supplied

Guilt, shame, and depression in clients in recovery from addiction.

Men and women in recovery from addiction were compared on levels of depression, guilt, and shame. The measurement of guilt included subscales of Survivor Guilt, Separation Guilt, Omnipotent Responsibility Guilt, Trait Guilt, State Guilt, and Adaptive Guilt. The sample included 75 men and 33 women in treatment in a residential treatment community. It was found that women were significantly higher than men in depression. The recovering subjects were compared to nonaddicted subjects and established norms, and it was found that the recovering people were higher on depression, shame, and the subscales of maladaptive guilt. Both men and women in recovery were significantly lower than norms in adaptive guilt.

Adult↗
PubMed1974

Inhibition within the trigeminal nucleus induced by afferent inputs and its influence on stimulus coding by mechanosensitive neurones.

1. In decerebrate, unanaesthetized cats two thirds of slowly adapting mechanosensitive neurones sampled in the trigeminal nucleus oralis exhibited inhibition in response to conditioning mechanical stimulation applied beyond their excitatory receptive fields. The influence of this inhibition was examined over the response range of these neurones using controlled, reproducible natural stimulation procedures.2. The extent of the inhibition was graded according to the intensity of the conditioning stimulus. It was evoked most strongly by vibratory skin indentation which very effectively excites rapidly adapting afferent fibres. Tonic conditioning inputs associated with steady skin indentation were less effective.3. The slope of stimulus-response relationships constructed from responses to inputs from the excitatory receptive field was reduced in 42% of trigeminal nuclear cells in the presence of afferent-induced inhibition. In the remainder the slope was unchanged.4. There was no evidence, in the neurones subject to inhibition, of an expansion of their dynamic range defined as the range of stimulus intensities over which a neurone exhibited a graded responsiveness.5. The variability in responses of an individual neurone at a given stimulus intensity was unchanged by this inhibition.6. Analysis of the stimulus-response data using information theory statistics revealed that neurones which underwent a reduction in the slope of their stimulus-response relationship in the presence of inhibition displayed a reduced capacity for defining the intensity of skin indentation. This capacity was not modified in those neurones where the slope was unchanged by the peripherally evoked inhibition.

Action Potentials↗
PubMed2003

Lot quality assurance sampling for screening communities hyperendemic for Schistosoma mansoni.

Lot quality assurance sampling (LQAS) was evaluated for rapid low cost identification of communities where Schistosoma mansoni infection was hyperendemic in southern Madagascar. In the study area, S. mansoni infection shows very focused and heterogeneous distribution requiring multifariousness of local surveys. One sampling plan was tested in the field with schoolchildren and several others were simulated in the laboratory. Randomization and stool specimen collection were performed by voluntary teachers under direct supervision of the study staff and no significant problem occurred. As expected from Receiver Operating Characteristic (ROC) curves, all sampling plans allowed correct identification of hyperendemic communities and of most of the hypoendemic ones. Frequent misclassifications occurred for communities with intermediate prevalence and the cheapest plans had very low specificity. The study confirmed that LQAS would be a valuable tool for large scale screening in a country with scarce financial and staff resources. Involving teachers, appeared to be quite feasible and should not lower the reliability of surveys. We recommend that the national schistosomiasis control programme systematically uses LQAS for identification of communities, provided that sample sizes are adapted to the specific epidemiological patterns of S. mansoni infection in the main regions.

Adolescent↗
PubMed1999

Technical note: a device for obtaining time-integrated samples of ruminal fluid.

A device was adapted to allow for time-integrated sampling of fluid from the rumen via a cannula. The sampler consisted of a cup-shaped ceramic filter positioned in the ventral rumen of a cannulated cow and attached to a tube through which fluid entering the filter was removed continuously using a peristaltic pump. Rate of ruminal fluid removal using the device was monitored over two 36-h periods (at 6-h intervals) and was not affected (P > .05) by time, indicating that the system was not susceptible to clogging during this period. Two cows having ad libitum access to a totally mixed ration were used in a split-block design to evaluate the utility of the system for obtaining time-integrated samples of ruminal fluid. Ruminal fluid VFA concentration and pattern in samples collected in two replicated 8-h periods by the time-integrated sampler (at 1-h intervals) were compared with composite samples collected using a conventional suction-strainer device (at 30-min intervals). Each 8-h collection period started 2 h before or 6 h after feeding. Results indicated that total VFA concentration was not affected (P > .05) by the sampling method. Volatile fatty acid patterns were likewise unaffected (P > .05) except that acetate was 2.5% higher (P < .05) in samples collected 2 h before feeding and valerate was 5% higher (P < .05) in samples collected 6 h after feeding by the suction-strainer device. Although significant, these differences were not considered physiologically important. We concluded that use of the ceramic filter improved the sampling of ruminal fluid by simplifying the technique and allowing time-integrated samples to be obtained.

Animals↗
PubMed1996

A comparison of adaptive and nonadaptive filters for reduction of power line interference in the ECG.

We have investigated the relative performance of an adaptive and nonadaptive 60-Hz notch filter applied to an ECG signal. We evaluated the performance of the two implementations with respect to adaptation rate (or transient response time), signal distortion, and implementation complexity. We also investigated the relative effect of adaptive and nonadaptive 60-Hz filtering on ECG data compression. With a 360 Hz sample rate and an adaptation time of approximately 0.3 s for a 1 mV 60-Hz signal, the adaptive implementation is less complex and introduces less noise, particularly in the ST-segment, into a typical ECG signal. When applied to ECG signals, prior to data compression by average beat subtraction and residual differencing, the residual signal resulting from the adaptively filtered signal had an average entropy 0.37 bits per sample (bps) lower than the unfiltered signal. The nonadaptive 60-Hz filter produced an average entropy decrease of 0.08 bps relative to the unfiltered ECG.

Algorithms↗
PubMed1998

Family functioning and social support in the adaptation of caregivers of children with sickle cell syndromes.

OBJECTIVE: To examine moderating effects of family functioning and social support on the relationship of child-related stressors to caregivers' psychological adaptation in a sample of caregivers of children with a chronic illness. METHOD: Participants were 67 caregivers of children and adolescents with sickle cell syndromes. We conducted MANOVAs and subsequent effect size calculations to determine if family functioning would buffer the effects of caring for difficult-to-manage children with this illness. RESULTS: Findings supported a moderator effect of family functioning on the association of children's externalizing behavioral problems to caregivers' symptoms of hostility. Greater levels of cohesive and adaptive family functioning buffered the potential detrimental effects of caring for children perceived as hard to manage. No significant associations were obtained between measures of caregivers' psychological adaptation and the severity of their children's disease. CONCLUSIONS: We make recommendations for family systems interventions, particularly for caregivers of children with behavior problems.

Adaptation, Psychological↗