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PubMedDate not supplied

Parental control in Latino families: an integrated review of the literature.

Using social information processing and cultural change models as explanatory frameworks, this article reviews the literature on Latino parental control and its implications for child development. It is argued that the use of parental control in Latino families may have motivational roots in cultural childrearing goals such as familismo (familism), respeto (respect), and educación (moral education). Consideration of these underpinnings, in conjunction with psychological and methodological issues, helps to explain variability in the use of Latino parental control and its effect on child development. Recommendations for future research include refinement of control and acculturation instruments, and attention to both contextual and individual variables.

Acculturation↗
PubMed2003

Normative values of bone parameters of children and adolescents using digital computer-assisted radiogrammetry (DXR).

PURPOSE: To verify whether estimation of bone mineral density (BMD) using digital X-ray radiogrammetry (DXR) is possible on children and to determine normative values of both such a DXR-BMD estimate and a corresponding metacarpal index (DXR-MCI) on. PATIENTS AND METHODS: In retrospect, X-rays were selected of the hands of 200 healthy Caucasian children (120 boys and 80 girls, aged 4-18 yr). The involved children were selected among a larger group of children submitted to the surgical department of our institute for evaluation of a suspected fracture after an occurred trauma. All children with a verified fracture or a chronic bone-related disease, including bone age retardation or acceleration, were excluded from the study. Furthermore, only conventional X-rays with the same film and capture parameters were included. The images were scanned and analyzed using the Pronosco X-posure system V.2 (Sectra Pronosco, Denmark). DXR-BMD, DXR-MCI, and a porosity index (DXR-PI) were automatically calculated using the midshafts of the metacarpals II-IV. Mean values of DXR-BMD and DXR-MCI were calculated separately for girls and boys in 2-yr intervals. RESULTS: In the present study the system has been demonstrated to be capable of calculating DXR-BMD from conventional X-rays of the hand from children down to approx 6 yr of age. This ability depended somewhat on the diameter and the length of the involved metacarpals. The success rate was higher for large bones than for small bones. The system succeeded in analyzing the images of 110 boys and 68 girls. Values of DXR-BMD were observed to increase with age from 0.40 g/cm2 to 0.62 g/cm2 in the male group and from 0.39 g/cm2 to 0.54 g/cm2 in the female group. Girls aged 11-12 yr had a higher DXR-BMD than did boys, corresponding to the earlier entry to puberty of girls. Standard deviations (SDs) reached values of up to 0.05 g/cm2. DXR-MCI increased with age from 0.36 to 0.47 for boys and from 0.34 to 0.49 for girls with a maximum SD of 0.06. The correlation between DXR-BMD and age was r=0.83 and r=0.84 for boys and girls, respectively. The corresponding correlations for DXR-MCI was lower, with observed correlations of r=0.63 (boys) and r=0.68 (girls), respectively, with p<0.01 in all cases. The DXR-PI did not reveal a significant correlation to age (r=-0.31 and r=0.04. respectively) and showed SDs marginally higher than the calculated mean values. CONCLUSION: The newly available DXR-methodology seems to offer the ability to determine DXR-BMD and DXR-MCI in children starting with a bone age of 6. This possibility may be of special relevance for children suffering from chronic bone diseases that require repeated X-rays of the hand (e.g. to determine bone age). The acquired normative data suggest that the measurements are of clinical value owing to low age-dependent variability (SDs) relative to an observed high increase with age. The clinical value of the porosity index (DXR-PI) remains uncertain and is limited owing to a high inter-individual variability.

Adolescent↗
PubMed2001

Relationships among selected measures of impairment, functional limitation, and disability in patients with cervical spine disorders.

BACKGROUND AND PURPOSE: Little is known about the relationship among impairments, functional limitations, and disability in people with cervical spine disorders (CSD) despite the fact that these concepts are routinely used in clinical practice. The primary purpose of this study was to investigate the relationships among commonly assessed impairment, functional limitation, and disability measures in patients with CSD. A secondary purpose was to determine the influence of payment source and time since onset of symptoms on these same measures. SUBJECTS: Eighty patients (mean age=45.7 years, SD=15.9, range=20-88) with CSD who were referred for physical therapy participated in the study. METHODS: Data were obtained for 3 measures of impairment, 2 measures of functional limitation, and 3 measures of self-reported disability during the initial visit. RESULTS: All 3 sets of variables (ie, impairment, functional limitation, disability) correlated with each other, with the highest correlation occurring between the impairment measures and the functional limitation measures (r=.82). Other correlations were noted between individual variables. There was no effect of payment type or time since onset of symptoms on the variables. CONCLUSION AND DISCUSSION: Positive correlations were noted among the 3 sets of measures, which supports the assumption that impairments, functional limitations, and disability are related in patients with CSD.

Activities of Daily Living↗
PubMed1992

Stretch reflex of quadriceps femoris in normal man: methodological considerations and normative data.

Short- and long-latency responses to stretching have been evoked in various muscles in the healthy subject. The quadriceps femoris, however, has never been investigated in this connection, despite its functional importance. We studied its stretch reflex in 17 healthy subjects with a torque motor to determine its morphological features in relation to the level of background EMG activity, the stretching velocity and duration and the instructions given to the subject. Two bursts of EMG activity were constantly evoked when the muscle was voluntarily activated. Response magnitude was proportional to the background activity and displacement velocity. Short stretching evoked only one EMG burst. These findings are similar to those from other muscles. Intra-individual variability was evaluated repeating the experiment in the same session without changing position of the electrodes, and then after two months. The long-latency response showed a good intra-individual reproducibility.

Adult↗
PubMedDate not supplied

Corneal wound healing in monkeys 18 months after excimer laser photorefractive keratectomy.

Excimer laser keratomileusis (photorefractive keratectomy, direct corneal ablation) for myopic corrections of 2.00 diopters (n = 1), 4.00 D (n = 4), and 8.00 D (n = 3) was performed on eight corneas of four Rhesus monkeys. All animals were followed for 18 months. The ablations healed normally and no epithelial erosions occurred. Serial slit-lamp microscope examinations revealed that a variable amount of corneal haze developed in all animals; this haze progressively faded during the follow-up period. Histopathology revealed an epithelium of normal thickness, basement membrane abnormalities, increased number and activity of stromal keratocytes, and a variable amount of newly secreted extracellular matrix in the anterior stroma. These findings suggest that excimer laser keratomileusis induces a mild wound healing response in the anterior cornea which displays considerable individual variability and persists up to 18 months.

Animals↗
PubMed1989

Static response in body temperature regulation of the euthermic warm-acclimated golden hamster (Mesocricetus auratus).

A characteristic feature of the body temperature regulation of euthermic golden hamsters is a great individual variability of body temperature in the thermoneutral zone. Resting values of the total metabolic rate (M) at ambient temperature 30-34 degrees C vary from 5.3 to 8.8 W.kg-1 between individuals, body temperature reaching 33.5-37.7 degrees C (subcutaneous temperature, Ts) and 35.4-39.0 degrees C (hypothalamic temperature, Th). The dependence of metabolic heat production on steady deviations of peripheral and central body temperature from the resting values in nonlinear in general, but the unknown functional relationship delta M = f (delta Th, delta Ts) can be replaced by a single linear regression function of Ts by neglecting the change of central body temperature: delta M = 2.14-2.00. delta Ts. Total body thermosensitivity of the golden hamster determined from steady changes of rectal temperature and metabolic rate after external cooling is -6.8 +/- 1.3 W.kg-1. degrees C-1.

Acclimatization↗
PubMed1990

Comparison of the effectiveness of slow-release propranolol (Inderal LA) 80, 160 and 320 mg orally daily in the treatment of angina pectoris.

Doses of 80, 160 and 320 mg of Inderal LA (slow-release propranolol) were compared in 12 patients with stable angina pectoris. There was an unpredictable and variable individual response to treatment and hence no differences were detected between the effects of the three doses on mean treadmill exercise duration, time to angina, frequency of angina or glyceryl/trinitrate consumption. There was a marked deterioration in two patients whilst on 320 mg Inderal LA. In these patients, the time to angina fell by 2 minutes 50 seconds and 4 minutes 20 seconds on 320 mg daily and 160 mg daily respectively. Given the inter-patient variability in response to Inderal LA, the dose for each patient should be individually titrated according to response. Two patients reported here suggest that some subjects may benefit from lower doses, although further work is required to clarify this point. Possible explanations for this finding are discussed.

Administration, Oral↗
PubMed2001

Bayesian estimation of variability in adipose tissue blood flow in man by physiologically based pharmacokinetic modeling of inhalation exposure to toluene.

Due to the lipophilicity of many xenobiotics, the perfusion of fat tissue is of special interest in physiologically based pharmacokinetic (PBPK) modeling. In order to estimate inter- and intra-individual variability in fat tissue blood flow with exercise, a population PBPK model for toluene was fitted to experimental data from subjects exposed to toluene vapors (Carlsson, A., 1982. Exposure to toluene: uptake, distribution and elimination in man. Scand. J. Work Environ. Health 8, 43-55). Six male volunteers were exposed to 80 ppm toluene for two hours during rest and moderate to heavy exercise (50-150 W). Extensive data collection was made, including sampling of arterial blood, exhaled breath and subcutaneous fat tissue. The model was simultaneously fitted to the time courses of toluene in arterial blood, exhaled breath, and subcutaneous fat in the six individuals by Markov chain Monte Carlo (MCMC) simulation. In order to describe the experimental observations in subcutaneous fat accurately, the fat compartment was split in two. According to the analysis, the increased perfusion of perirenal fat associated with physical workload was best described if it was set to the same, elevated, level during all exercise levels, rather than scaled directly to the increase in oxygen uptake. No increase in subcutaneous fat perfusion could be detected at these exposure conditions.

Adipose Tissue↗
PubMed2005

Simplex maximization of the correlation coefficient for DNA sizing analysis by capillary electrophoresis.

The separation of DNA molecules in polymeric solution by capillary electrophoresis involves the optimization of several variables, such as polymer solution concentration, electric field separation, temperature, etc. The optimization of each variable individually usually is a time-consuming process and the results may reach a false optimum point. Chemometric methods are suitable to be applied in such cases in which a number of variables can be optimized simultaneously. The simplex is a chemometric method that can perform such a task easily and efficiently. In this study, a simplex method was carried out to maximize the correlation coefficient (r(2)) of a logarithmic plot of mobility (mu) vs. base pair (bp), which was obtained from the separation of DNA fragments of size between 75 and 4072 bp. The simplex showed three vertexes with r(2) > 0.98 and the vertex 21 showing the highest resolution. For the fragments between 201 and 2036 bp, the r(2) increased to 0.992 with and relative standard deviation (RSD) lower than 0.2% (inter- and intra-day variation). The precision of the method in determining the size of a PCR DNA fragment was carried out using a 1 kbp DNA ladder. With the addition of an internal standard to the sample, the precision could be further improved.

Chemical Fractionation↗
PubMed2002

Stereotactic imaging of the pallidal target.

In 48 consecutive patients, we applied a new stereotactic imaging technique to individually visualize the pallidal target before surgery. A turbo spin-echo proton density sequence (acquisition time, 6 minutes 5 seconds) was used for 2-mm-thick contiguous axial scanning. Pallidocapsular border, medial putaminal border, and optic tract were visualized bilaterally in all patients. Boundaries of globus pallidus internus, globus pallidus externus, and lamina medullaris interna were clearly visualised in 71% of the patients. The anatomic target point was chosen in the middle of the visualized posteroventral pallidum, irrespective of the position of this point in relation to commissures. The lateralities of pallidocapsular border, lamina medullaris interna, and medial boundary of putamen were measured bilaterally in each patient, and the width of the posteroventral pallidum was assessed. The laterality of structures (measured from a point 2 mm anterior to midcommissural point and at a level 2-4 mm below anterior commissure-posterior commissure line) showed a wide range. The position of the pallidocapsular border varied by up to almost 1 cm between the most medial and the most lateral one. There were also variations in the position of the pallidal structures between left and right hemispheres in the same patients. The posteroventral pallidum was slightly more wide on the left than the right side. Given the significant inter- and intra-individual variabilities of the position of pallidal structures, it may be hazardous to rely solely on the atlas and the commissures for targeting. A magnetic resonance imaging sequence that enables visualization in each individual patient of the target area and its surroundings may contribute to less electrode passes during intraoperative physiological exploration and to more exact location of the lesion or chronic electrode in the posteroventral pallidum.

Adult↗
PubMed1976

Spatio-temporal organization of EEG in premature infants and full-term new-borns.

Inter- and intrahemispheric EEG relationships were studied as a function of maturation in new-born infants. The spatio-temporal organization of EEG activity obtained during the two stages of sleep described in new-born infants - quiet sleep and active sleep - was analysed in 9 full-term new-born infants and 5 prematures (6 records). EEGs were recorded through transverse parietal montage made up of six bipolar derivations. Two epochs of 1.5 min each - successively obtained in both stages of sleep - were digitized, filtered in three frequency bands (beta, theta and delta) and computer-processed according to two methods, factor analysis and rhythms averaging. 1. The following EEG characteristics were found in both groups: (a) Instability of frequency within each frequency band (beta, theta and delta). However, theta activity was the most stable of the three, especially in quiet sleep. (b) Variability of topographical organization (i.e., localization of maxima of potentials) from one moment to another in both stages of sleep and in the three frequency bands. In spite of this intra-individual variability some sort of "average structure" was found in all infants; it was characterized by usually lateral and often symmetrical positions of the maxima of potential on the two hemispheres. For the same infant this structure was the same in the three frequency bands. (c) Poor interhemispheric relationships under all conditions, as well as poor interregional links in one hemisphere. 2. Some EEG characteristics differentiated the two groups and thus seemed to be related to maturation. Compared to full-term newborns the premature group showed: better stability for all three activities, especially for beta activity; higher frequency and larger amplitude of beta activity; better inter- and intrahemispheric relationships; fewer differences related to sleep stages. These results are discussed in terms of organization of the underlying cortical generators. The authors suggest that the active areas would increase in number and in surface with maturation, whereas the links between these different separate areas would remain very poor in the human full-term new-borns as well on one hemisphere as across hemispheres. This last finding would argue against the hypothesis that the corpus callosum which, as is well known, matures early, plays an important role in the establishment of interhemispheric links.

Age Factors↗
PubMed1993

A noninvasive strategy for identifying and quantifying innocuous and nociceptive peripheral afferent activity evoked by nerve stimulation.

This study evaluated the utility of the compound nerve action potential (CAP) and spinal nociceptive withdrawal (R3) reflex in identifying and quantifying peripheral afferent activity evoked by sural nerve stimulation in humans. The results of this work demonstrate that currents less than or equal to that which elicits a just-maximal CAP can be considered purely innocuous; provide further evidence that the R3 is an objective means of identifying noxious stimulus levels; and suggest that current provides the best noninvasive quantitative estimate of afferent activity throughout the innocuous and noxious range. This work also demonstrates that some of the individual variability in the psychophysical function can be attributed to peripheral factors that affect the amount of current reaching the nerve. It is important, therefore, that these peripheral factors be considered when studying individual differences in the psychophysical function generated by electrical stimulation.

Adolescent↗
PubMed1990

Rehospitalization of infants born to adolescent mothers.

This study defines the variables that predict rehospitalization of infants born to teen mothers. Rehospitalization was defined as hospital admission during the first year of life subsequent to hospitalization at birth. Normal birth weight (NBW), but not low birth weight (LBW), infants of adolescent mothers had higher rehospitalization rates than infants of older mothers. NBW infants of young vs. older mothers had significantly higher rehospitalization rates for gastroenteritis. Among infants of adolescent mothers, the variables associated with increased risk of rehospitalization were unemployed household head, presence of a congenital anomaly or developmental delay, and an unusually high or low number of well child care visits. Although individual variables were significant at the bivariate level, in combination, these variables were poor predictors of which infants would be rehospitalized. Our study suggests that all teen mothers of NBW infants may require additional education to prevent excess rehospitalization of their infants.

Adolescent↗
PubMed2004

Effects of parametric feeding manipulations on behavioral performance in macaques.

Early experimental psychologists made broad use of knowledge that is undoubtedly as old as animal domestication, i.e., that the power of appetitive reinforcement is enhanced by restricting the subjects' access to food. This has led to the nearly universal practice of restricting common laboratory rodent and avian subjects to 85% of free-feeding weight for operant experiments. Appetitive operant procedures in nonhuman primates (NHPs) vary more widely, in part because of the time required for such animals to reach mature weight and greater individual variability in body size compared with inbred laboratory species. In addition, many NHPs will grow obese under true ad-libitum feeding. Therefore, food restriction protocols for monkeys tend to be highly individualized and conducted on the basis of laboratory experience within a given model. The present study was undertaken to determine to what extent short-term, ad-libitum food consumption in rhesus macaques would impair performance on an established neuropsychological testing battery. A second part of the study was to formalize food-restriction parameters to determine what degree of restriction was required to produce consistent behavioral performance. Results show clearly that behavioral performance on a range of tasks is detrimentally affected by short-term, ad-libitum chow feeding, even when the reinforcer is highly preferred or the tasks are well trained. Furthermore, it is shown that maintenance of weekly chow intake in the range of 70-85% of National Research Council recommendations for metabolizable energy is necessary for consistent behavioral responding.

Analysis of Variance↗
PubMed2003

An exploratory study using data envelopment analysis to assess neurotrauma patients in the intensive care unit.

Patients with severe head trauma were studied retrospectively to determine if Data Envelopment Analysis (DEA) could successfully model patients early in their stay in an intensive care unit. Variables examined were cerebral perfusion pressure, body temperature, mean arterial pressure, serum osmolarity and pCO2. Unlike regression-based models that focus on mean values for the group, DEA evaluates each patient individually calculating an "efficiency" score based on a patient's ability to maximize output for a given set of physiologic inputs. Patients with high efficiency scores were found to have a better chance of making a full recovery than similarly injured patients that were inefficient. This approach needs further study but may offer physicians the opportunity to improve patient outcome subject to the manipulation of individual variables from the results of a DEA model rather than aiming for normal or average physiologic values.

Brain Injuries↗
PubMed2003

Subject-specific compressive tolerance estimates.

Spinal load models have become an increasingly valuable tool for the evaluation of the stress placed on the spine. In order to get an accurate representation of these spinal loads, they must be compared to known tolerance values. Bone mineral content and density of the lumbar spine of 23 males and 21 females was measured using a dual energy x-ray absorptiometry. Compression tolerance values were predicted by previously published studies based upon bone mineral levels. Anthropometric measurements were recorded and related to the compression tolerance values through the use of multivariate linear regression techniques. Compression tolerance values based on the bone mineral content or density explains more of the individual variability than solely age-based estimates. Several anthropometric variable regression models were developed that resulted in moderate to good predictive power (R(2) = 0.62 to 0.81). The current study describes a useful alternative to traditional tolerance estimates that accounts for individual differences requiring non-invasive and time-efficient procedures.

Absorptiometry, Photon↗
PubMed1990

Variability in transepidermal water loss of the skin: evaluation of a method to assess susceptibility to contact dermatitis in epidemiological studies.

Transepidermal water loss (TEWL) has been suggested to be a measure which can be used to identify subjects at risk for the development of contact dermatitis. Transepidermal water loss is high when the barrier function of the skin is impaired. It is assumed that subjects with a high TEWL have skin which is more permeable to substances causing contact dermatitis. The inter-individual and intra-individual variability of simultaneous TEWL measurements and TEWL measurements over a period of three weeks were estimated in healthy individuals. The intra-individual coefficient of variation (CV) of simultaneous measurements was 13.5%. The intra-individual coefficient of variation of the measurements on consecutive days was somewhat higher (15.1%). The intra-individual coefficients of variation were low compared to the inter-individual coefficients of variation. The results indicate that transepidermal water loss is a stable personal characteristic, which can be studied as a risk factor in epidemiologic studies on contact dermatitis.

Adult↗
PubMed1987

Reproducibility of rest and exercise left ventricular ejection fraction and volumes in chronic aortic regurgitation.

To assess the variability of rest and exercise radionuclide ventriculography in patients with aortic regurgitation (AR), 22 patients in stable condition with chronic AR underwent radionuclide ventriculography at rest and during exercise for measurement of left ventricular volumes and ejection fraction (EF) on 2 occasions 3 months apart. For the group, there were no significant differences between the findings of the 2 studies except for a slightly lower exercise end-systolic volume on the second study. The inter-study differences and variabilities (expressed as the standard deviation of differences) for rest and exercise EF and change in EF were 0 +/- 0.04, +0.02 +/- 0.05 and +0.01 +/- 0.05, respectively. Thus, although mean differences were minor, considerable individual variability occurred, the magnitude of which was similar to that reported for other patient populations. In 3 patients who had an initial normal response to exercise (increase in EF greater than or equal to 0.05), the response became abnormal and in 2 who initially had an abnormal response, the response normalized. This variability must be considered in clinical decision-making or in research study design for patients with chronic AR.

Adult↗