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At least 1,189 records · Page 66Linked to original sources
PubMed2006

Stomach temperature telemetry reveals temporal patterns of foraging success in a free-ranging marine mammal.

1. We studied feeding frequency in free-ranging grey seals using stomach temperature telemetry to test if previously reported sex differences in the diving, movement and diet were reflected in the temporal pattern of foraging success. 2. Data were retrieved from 21 of 32 grey seals from 1999 to 2001, totalling 343 days and 555 feeding events, with individual record length varying from 2 to 40 days (mean: 16.33 +/- 2.67 days/seal). 3. Seals fed on 57.8 +/- 6.46% of days sampled and had an average of 1.7 +/- 0.26 meals per day, but individual variability was apparent in the temporal distribution of feeding as evidenced by high coefficients of variation (coefficient of variation = 69.0%). 4. Bout analysis of non-feeding intervals of six grey seals suggests that feeding intervals of individuals were varied and probably reflect differences in prey availability. Grey seals tended to have many single feeding events with long periods separating each event, as would be expected for a large carnivore with a batch-reactor digestive system. 5. We found significant sex differences in the temporal distribution of feeding. The number of feeding events per day was greater in males (2.2 +/- 0.4 vs. 1.0 +/- 0.2), as was time associated with feeding per day (56.6 +/- 5.8 min vs. 43.9 +/- 9.4 min). 6. The number of feeding events varied with time of day with the least number occurring during dawn. Feeding event size differed significantly by time of day, with greater meal sizes during the dawn and the smallest meals during the night. 7. The length of time between meals increased with the size of the previous meal, and was significantly less in males (541.4 +/- 63.5 min) than in females (1092.6 +/- 169.9 min). 8. These results provide new insight into the basis of sex differences in diving and diet in this large size-dimorphic marine predator.

Animals↗
PubMed2000

Antepartum evaluation of monochorionic diamniotic (MD) twins; MD-twin score: a new scoring method for perinatal outcome.

OBJECTIVE: Our purpose was to establish a new scoring method to survey monochorionic diamniotic (MD) twins during antepartum periods. STUDY DESIGN: A retrospective study was performed regarding MD twins delivered between January 1992 and July 1996. Maternal and neonatal records were assessed for the following 5 perinatal variables; birth-weight discordance, amniotic-fluid discordance, hydrops fetalis, umbilical-cord insertion, and fetal-heart-rate monitoring. Each variable was coded as normal or abnormal and then assigned an arbitrary weight of 0 if normal and 1 if abnormal, yielding a range of scores from 0 (all normal) to 5 (all abnormal). The relationships between individual variables and their combinations and the outcome of pregnancy was determined. A poor pregnancy outcome consisted of intrauterine death, neonatal death, or neurological sequelae of at least one twin. The 5-variable combination was termed as the MD-twin score. A chi-square test and logistic regression analysis were used to determine statistical significance. RESULTS: There were 59 MD pregnancies, of which 13 pregnancies resulted in a poor outcome. The single variable that most likely contributed to a poor outcome was amniotic-fluid discordance. All 35 pregnancies with an MD-twin score of < or = 2 had a good outcome. There were 14 pregnancies with a score of 3, and 21% of them had a poor outcome. All of the pregnancies with a score of > or = 4 had a poor outcome. When we chose the MD-twin score of 3 as the critical point for a poor outcome, the likelihood ratio statistics became the highest of any single variable or any combination of variables. CONCLUSION: The MD-twin score predicted poor outcomes better than did any single variable or combination of variables.

Amniotic Fluid↗
PubMed2006

Continuous online monitoring of ionic dialysance allows modification of delivered hemodialysis treatment time.

Considerable intrinsic intrapatient variability influences the actual delivery of Kt/V. The aim of this study is to examine the feasibility of using continuous online assessment of ionic dialysance measurements (Kt/V(ID)) to allow dialysis sessions to be altered on an individual basis. Ten well-established chronic hemodialysis (HD) patients without significant residual renal function were studied (mean age 65+/-4.3 [38-81] years, mean length of time on dialysis 66+/-18 [14-189] months). These patients had all been receiving thrice-weekly 4-hr dialysis using Integra dialysis monitors. Dialysis monitors were equipped with Diascan modules permitting measurement of Kt/V(ID). Predicted treatment time required to achieve a Kt/V(ID) > or = 1.1 (equivalent to a urea-based method of 1.2) was calculated from the delivered Kt/V(ID) at 60 and 120 min. Treatment time was reprogrammed at 2 hr (ensuring all planned ultrafiltration would be accommodated into the new modified session duration). Owing to practical issues, and to avoid excessively short dialysis times, these changes were censored at no more than+/-10% of the usual 240-min treatment time (210-265 min). Data were collected from a total of 50 dialysis sessions. Almost all sessions (47/50) required modification of the standard treatment time: 13/50 sessions were lengthened and 34/50 shortened (mean length of session 232.2+/-2.5 [210-265] min). A Kt/V(ID) of > or = 1.1 was achieved in 39/50 sessions. The difference in mean urea-based Kt/V poststudy (1.3+/-0.05 [1.1-1.6]) and mean achieved Kt/V(ID) (1.16+/-0.02 [0.7-1.37]) was significant (p = 0.002). The use of individualized variable dialysis treatment time using online ionic dialysance measurements of Kt/V(ID) appears both practicable and effective at ensuring consistently delivered adequate dialysis.

Adult↗
PubMed2000

The therapeutic effect of theophylline in mild obstructive sleep Apnea/Hypopnea syndrome: results of repeated measurements with portable recording devices at home.

Theophylline has been recommended in the literature as a therapeutic option in mild OSAHS. In mild obstructive sleep apnea/hypopnea syndrome (OSAHS), night-to-night variability of parameters of sleep-disordered breathing has been determined rarely, we therefore compared the results of serial measurements of sleep apnea/hypopnea parameters under the effects of placebo and theophylline. To this end, we measured the individual variability of the apnea-hypopnea index (AHI) for seven consecutive nights using a portable sleep apnea recording device, in 14 subjects (2 women, 12 men, mean age +/- [standard deviation] 50 +/- 8 years), treated with placebo or theophylline in a double blind, randomized crossover fashion, whose polysomnographically measured AHI was 13 +/- 5 /hour. Under theophylline treatment in comparison with placebo we observed a small but significant decrease in mean (of seven days) AHI at home (9.2 +/- 7.7 to 6.7 +/- 6.1 /hour), which was independent of body position. The night-to-night variability of AHI at home was high (9. 2 +/- 8.9 /hour; range: 0-31.4 /hour) and proved to be independent of body position and alcohol consumption. - In mild OSAHS, repeated measurements of sleep related breathing events should be performed. Theophylline showed a small but clinically insignificant potencial to reduce AHI.

Adult↗
PubMed1985

[Influence of treatment course on the success of psychopharmacotherapy].

Psychiatric illness course is not characterized by total regularity. More often there is marked individual variability. This is an obstacle to making a valid prognosis and applying broadly based indication rules. Still today predictors of illness course as well as indication criteria for treatment are little elaborate and often faile in the individual case. The most reliable instrument for planning and assessing psychiatric treatment is the treatment course itself. The therapist as a participating observer can more easily check tendencies of illness course and adapt therapeutic strategies. Characteristics of treatment course in guiding further treatment are examplified by means of neuroleptic treatment in the acute and maintenance phase of schizophrenic psychoses.

Antipsychotic Agents↗
PubMed2006

Wistar rats with high versus low rearing activity differ in radial maze performance.

Substantial work has shown that rats although identical in stock, sex, age, and housing conditions can differ considerably in terms of behavior and physiology. Such individual differences, which can be detected by specific behavioral screening tests, are rather stable, that is, they probably reflect a behavioral disposition or trait. Here, we asked whether and how such differences might affect performance in a task of spatial learning and memory, the radial maze. As in our previous work, we used the degree of rearing activity in a novel open field to assign male adult outbred Wistar rats into those with high versus low rearing activity (HRA/LRA rats). They were then tested in a plus-maze for possible differences in anxiety-related behavior. Finally, and most importantly, they were food deprived and underwent maze training using an 8-arm radial maze with four non-baited and four baited arms. One of these arms consistently contained a larger bait size than the other three. In the open field, HRA rats not only showed more rearing behavior, but also more locomotor activity than LRA rats. In the plus-maze, HRA rats again showed more locomotion, but did not differ in open arm time or percentage of open arm entries, that is, conventional measures of anxiety-related behavior. In the radial maze, HRA rats consistently needed less time to consume all pellets than LRA rats, which was due to faster locomotion on the arms and less time spent at the food pits (especially in baited arms) of HRA rats. During the initial days of training, they were also more efficient in obtaining all food pellets available. Furthermore, HRA rats visited more arms and made relatively less reference memory errors than LRA rats. This allowed them to forage food quickly, but was paralleled by more working memory errors than in LRA rats. In general, working memory errors were more frequent in the arm with the large bait size, but there were no indications that HRA and LRA rats responded differently dependent on reward size. Finally, LRA rats lost slightly more weight than HRA rats during the period of food deprivation. These results are discussed with respect to the role of cognitive and motivational mechanisms, which as subject-inherent factors can contribute substantially to inter-individual variability in the radial maze.

Analysis of Variance↗
PubMed2004

Variability in energy expenditure and its components.

PURPOSE OF REVIEW: To review factors contributing to variation in total daily energy expenditure and its primary components: (1) resting metabolic rate; (2) diet-induced thermogenesis; and (3) activity thermogenesis, including exercise energy expenditure and nonexercise activity. For each component, the expected magnitude of intra-individual variability is also considered. We also reviewed studies that quantified the variability in 24 h energy expenditure. RECENT FINDINGS: In humans, the coefficient of variation in the components of total daily energy expenditure is around 5-8% for resting metabolic rate, 1-2% for exercise energy expenditure, and around 20% for diet-induced thermogenesis. The coefficient of variance for 24 h energy expenditure measured using a room calorimeter for resting metabolic rate is around 5-10%. Thus, these measures are all rather reproducible. Total daily energy expenditure varies several-fold in humans, not due to variation in resting metabolic rate, diet-induced thermogenesis, or exercise thermogenesis, but rather, due to variations in nonexercise activity. A variety of factors impact nonexercise activity, including occupation, environment, education, genetics, age, gender, and body composition, but little is known about the magnitude of effect. SUMMARY: Resting metabolic rate, diet-induced thermogenesis, exercise energy expenditure, and 24 h energy expenditure are highly reproducible. Coefficient of variation is smallest for exercise energy expenditure, followed by resting metabolic rate, 24 h energy expenditure, and diet-induced thermogenesis. There is considerable variability in total daily energy expenditure, largely due to variations in nonexercise activity. Although the factors that impact upon nonexercise activity are understood, their contribution to variation in total daily energy expenditure is unclear.

Basal Metabolism↗
PubMedDate not supplied

Fatigability of the stapedius reflex in industrial noise.

Normal hearing subjects were monaurally exposed to 30 min of tape recorded shipyard noise (97 dB (A)) which is characterized by a variable temporal structure. The stapedius muscle activity was continuously recorded in the opposite ear as a change of the ear's acoustic impedance. The reflex function was, in addition, assessed as stimulus-response curves obtained before and, at various times after, exposure. A slight reflex fatigue was observed, together with a parallel shift of the stimulus-response curve (average 4 dB). The recovery was slow and not complete even 10 min after the end of the exposure. The individual variability was large. For 5 of the subjects the exposure was repeated at a later session and the individual degree of fatigue was found to be largely producible. The present results suggest that the stapedius reflex might play a role in the clinical picture of noise induced hearing loss.

Acoustic Impedance Tests↗
PubMed1999

Energy expenditure determined by self-reported physical activity is related to body fatness.

OBJECTIVE: Activity self-reports are a commonly used tool in assessing daily physical activity (PA) and associated energy expenditure (EE). This study examined the effect of relative body fatness (%BF) on differences between self-reported and measured duration and associated EE in healthy adults. RESEARCH METHODS AND PROCEDURES: Men and women (n = 115, age 38+/-9 years), ranging in %BF from 7.9% to 58.9%, spent two separate days (normal and exercise) in a whole-room indirect calorimeter where EE was measured. While in the room calorimeter, subjects reported the type, intensity, and duration of each performed PA. The Compendium of Physical Activity was used to calculate the energy cost of each reported activity. The EE of all self-reported activities (EEr) was categorized into four intensity levels, synchronized, and compared with EE from the room calorimeter (EEm). RESULTS: With increasing %BF, subjects significantly overestimated duration of more strenuous activities (> or =4.5), while underestimating moderate activities (2.5 to 4.4 metabolic equivalents (METs)). Misreporting of duration and/or intensity caused an overestimation or underestimation of PA-associated EE at these levels. Reported EE sleep was lower than measured EE sleep, although both had similar durations. As a result, total EEr was similar to EEm. DISCUSSION: Individual variability of daily total PA and associated EE generated from self-reports in adults is high. Persons with a higher %BF report duration and/or intensity of moderate to high levels of PA with lower accuracy than leaner individuals. We conclude using the Compendium of Physical Activity is not suitable for the accurate estimation of self-reported EE of AA in adults with a higher %BF.

Adolescent↗
PubMed1998

Family characteristics and behavior problems of suicidal and non-suicidal children and adolescents.

The present study examined familial and individual variables in youngsters at high risk for suicide and non-suicidal youngsters. One hundred inpatient children and adolescents completed a battery of questionnaires including, FACES II, Family Strengths, and Problem Behavior Scales, to assess family dysfunction and individual behavior problems. The results indicated that suicidal youngsters have lower pride in their families and perceived them as less adaptable than non-suicidal youngsters as indicated by scores on the Family Strengths and FACES II, respectively. Scores on the Problem Behavior Scales indicated that suicidal youngsters also exhibited self-inflicted behaviors, withdrawal from others, little interest in activities, poor concentration, and difficulties with sleeping. In addition, youths at risk for suicide were more likely to be diagnosed with a mood disorder, including major depressive disorder and dysthymia, as well as substance abuse and phobias. These findings suggest that suicidal youngsters' negative perceptions of their families and their maladaptive behaviors should be given special attention in designing appropriate interventions. In this way, treatment would likely be effective by providing appropriate coping skills and preventing future suicidal attempts in high risk youngsters.

Adolescent↗
PubMed1981

Detection of ozone toxicity during continuous exercise via the effective dose concept.

In evaluating O3 toxicity in humans, the effective dose, expressed as the simple product of concentration, exposure duration and ventilation volume (VE), has been applied only to resting or intermittent exercise (IE) exposures. In the present study, we examined the validity of effective dose in predicting pulmonary function impairment when effective dose was determined both as a simple product and as a weighted function via multiple regression. Eight trained male subjects (ages 22-46) completed 18 protocols, including exposures (via mouthpiece) to filtered air and three levels of O3 concentration (0.20, 0.30, and 0.40 ppm), while exercising continuously for durations ranging from 30 to 80 min. The O3 effective dose was significantly related to pulmonary function impairment and exercise ventilatory pattern alteration. Multiple regression analysis, however, substantiated the predominant importance of O3 concentration, with the threshold for O3 toxicity during exercise at a moderately heavy work load [approximately 65% maximum O2 uptake (VO2 max)] shown to be between 0.20 and 0.30 ppm. Although considerable individual variability in O3 toxicity response was noted, group mean responses in our continuous exercise mouthpiece exposures were similar to those previously observed with IE chamber exposures. Thus while the effective dose concept has notable deficiencies in predicting the individual degree of O3 toxicity, it remains a useful approach and warrants further investigation.

Adult↗
PubMedDate not supplied

Functional versus organic knee pain in adolescents. A pilot study.

Psychologic factors, usually assessed with the Minnesota Multiphasic Personality Inventory, have been reported by various researchers as significant in certain groups of adult orthopaedic patients--most notably those with low back pain. Much less is known about children and adolescents or other orthopaedic complaints. We did a pilot study to determine how significant nonorganic factors are in adolescents presenting with knee pain and whether a brief screening protocol conducted in the waiting room can predict which adolescents do not have organic etiology for the knee pain. Twenty-eight consecutive adolescents were given the Junior-Senior High School Personality Questionnaire (HSPQ), and information on other variables was obtained prior to their first orthopaedic visit. Followup after six to eight months revealed that over a third of the patients had significant or predominant psychologic factors associated with the knee pain. The HSPQ and other individual variables were found, overall, to be of little help in differentiating between the functional and organic groups.

Adolescent↗
PubMed1989

[Pharmacokinetic monitoring during aminoglycoside treatment: the optimal method for individualizing the dosage of tobramycin].

The results of tobramycin concentration monitoring in 33 patients with nonspecific pulmonary infections showed a marked individual variability of the antibiotic blood levels and model-independent pharmacokinetic parameters: total clearance, steady-state volume of distribution and mean residence time whose values were distributed log-normally. Adjusting of the tobramycin dosage by the individual values of the clearance (three-point method, by concentrations 1 h (C1), 3 h (C3) and 6 h (C6), after intramuscular single administration of the antibiotic and one-point method, by C3, after repeated administrations of the antibiotic) provided by the end of a 7-day course a 1.7-fold decrease in the individual ranges of the antibiotic concentration as compared to those without the dosage adjusting. Retrospective analysis revealed that reliable individual dosing of tobramycin was provided with the simplest one-point method when the only blood specimen was collected 3 hours after the injection, i.e. the time interval inversed to the elimination rate constant. According to this method individual doses Dind were calculated by the equation Dind = DpopCpop/Cind, where pop was the population value of D and C. The values of Dind estimated in such a way did not practically differ from those estimated with the more complicated two-point (by C1 and C6) and three-point methods. Application of the equation to the tobramycin "maximum" concentration C1 or the "minimum" one (toward the end of the dosing interval, C6) resulted in less accurate and unbiased estimation of Dind.

Adolescent↗
PubMed2006

Determinants of physicians' patient-centred behaviour in the medical specialist encounter.

It has been suggested that patient-centred communication does not necessarily translate into a 'one-size fits all' approach, but rather that physicians should use a flexible style and adapt to the particular needs of their patients. This paper examines variability in physicians' patient-centred behaviour in medical specialist encounters, and determines whether patient, visit, and physician characteristics influence this variability. Participants were 30 residents and specialists in internal medicine at an academic teaching hospital in The Netherlands, and 323 patients having a (videotaped) outpatient follow-up appointment. Physicians and patients completed a questionnaire prior to the encounter. Consultations were coded using the Patient-centred Behaviour Coding Instrument (PBCI); physicians' patient-centred behaviour was determined by behaviours that facilitated rather than inhibited the patient's expression of his/her perspective. The results show that physicians differ in their communicative behaviour (i.e. inter-individual variability): some internists had a more 'patient-centred' communication style and others less so. At the same time, physicians show intra-individual variation; apparently they adjust their style according to the situation. Physicians displayed more facilitating behaviour when patients were older, reported more physical symptoms, when they rated patients' health condition as more severe and when the physician was a woman. Physicians also displayed more inhibiting behaviour when patients reported more physical symptoms and when the physician rated patients' health condition as more severe. Apparently, sicker patients were targets of both greater facilitation and greater inhibition. Variability in physicians' facilitating and inhibiting behaviour was explained by patient characteristics, i.e. patients' age and health condition, and-with the exception of physician gender-not by physician or visit characteristics. This indicates that physician patient-centred behaviour is related to the type of patient visiting, especially in relation to the seriousness of symptoms.

Adult↗
PubMed1999

Flight speed and body mass of nectar-feeding bats (Glossophaginae) during foraging.

Aerodynamic theory predicts that minimum power (Vmp) and maximum range (Vmr) flight speeds increase when the body mass of an individual animal increases. To evaluate whether foraging bats regulate their flight speed within a fixed speed category relative to Vmp or Vmr, I investigated how the natural daily changes in body mass caused by feeding affected the flight speed of neotropical nectar-feeding bats (Phyllostomidae: Glossophaginae) within a strictly defined, stereotyped behavioural context. Individual bats were maintained in a flight tunnel (lengths of five different types 14-50 m) with a fully automated feeding, weighing (using an electronic balance at the roost) and flight speed measuring system. Flight speeds were measured during normal nocturnal foraging activity by an undisturbed bat while it flew between the two ends of the flight tunnel to obtain food from two computer-controlled nectar-feeders. For a comparison of flight enclosure measurements with field data, flight speeds were also obtained from unrestrained bats foraging in their natural environment (Costa Rica). Foraging flight speeds spanned a range of at least a factor 3 within a single species, which demonstrates the wide range of speeds possible to these animals. Significant, positive correlations between flight speed and the natural individual variability in body mass were found in nearly all cases, with body mass exponents ranging between 0.44 and 2.1. Bats flying at normal speeds were therefore not near their upper limit of muscle power. The most reliable measurements of speed increase with mass (with individual mass changes of up to 30%) were close to the increase theoretically predicted for Vmp and Vmr for an individual bat (with constant wing span and area), which should vary as M0.42, where M is mass. This provides evidence that the glossophagine bats attemped to maintain their flight speed within a fixed speed category relative to Vmp or Vmr during foraging. Among differently sized species of glossophagine bat (N=4), flight speeds V varied with V=20M0.23, in agreement with the mass exponent of 0.21 expected from aerodynamic models for interspecific variation. In addition to the mass effect, at least five other variables significantly influenced flight speed. (1) Both mean and maximum flight speeds increased with the length and the cross-sectional area of the flight tunnel. Mean (maximum) flight speeds of 11-12 g Glossophaga soricina bats (in m s-1) were 4.6 (5.3) over a 7 m and 7. 3 (10.5) over a 50 m flight path. (2) The flight speed range adopted by a bat during one night could vary significantly between nights, independently of body mass and the effect of the size of the flight enclosure. (3) Bats flew significantly faster under illumination than in darkness. This effect was shown (i) by bats kept under natural ambient illumination that initiated foraging during the twilight phase of the evening, (ii) when bats continued to feed into the light phase directly after the dark-light transition in the laboratory and (iii) during foraging under constant, artificial illumination. (4) After a period of rest, the initial flight speed during a foraging bout was significantly increased by 25%, but declined to the mean level within 20 s of activity. (5) Flight speed could differ significantly between foraging (flight from feeder to feeder) versus non-foraging (flight from end to end of the enclosure without visiting the feeders) flights. The results of this study demonstrate a clear ability of bats to regulate their flight speed in response to small natural changes in body mass as predicted by aerodynamic theory for Vmp and Vmr. The set point in flight speed regulation, however, was influenced by multiple additional variables.

Animals↗
PubMed2004

Pharmacogenetics of antipsychotic-induced weight gain.

RATIONALE: Antipsychotic medications have been associated with considerable weight gain. The degree of inter-individual variability and known genetic contributions to obesity suggest a combination of genetic and environmental factors. In the absence of established mechanisms and valid predictors for this relevant adverse effect, pharmacogenetic studies may provide the basis for the development of individualized treatment and preventive interventions. OBJECTIVE: The aim of the present review is to analyze the theoretical and empirical knowledge base for the selection of the most promising target genes that may contribute to antipsychotic-induced weight gain. METHODS: Examination of the preclinical and clinical literature that can inform the rational choice of target genes that may play a role in the development of adverse changes in body composition associated with antipsychotic treatment. RESULTS: Theoretically, candidate gene selection can be guided by knowledge about molecular pathways associated with obesity, receptors modulated by antipsychotic drugs, and enzymes implicated in their metabolism and bioavailability. While most available data relate to the general mechanisms of obesity and few studies have directly examined the genetic contributions to antipsychotic-induced weight gain, several genes warrant further investigation. These include the 5-HT(2C), pro-opiomelanocortin, leptin, ghrelin, tumor necrosis factor alpha, adiponectin, dopamine D(2) receptor, histamine-H(1) receptor, and alpha(1), beta(2) and beta(3) adrenergic receptor genes. CONCLUSIONS: Pharmacogenetic studies can provide powerful tools for the pre-treatment identification of individuals at high risk for antipsychotic-induced weight gain, to uncover biological mechanisms that may even generalize to non-drug-induced weight gain, and to isolate novel targets for treatments of weight gain and obesity. To enhance power, future studies should pay close attention to population selection and avoidance/control of confounds, particularly past treatment exposure.

Adiponectin↗
PubMed1988

Hierarchical time-oriented approaches to missing data inference.

In practice clinical data are nearly always incomplete. When confronted with such data, a physician or investigator must make inferences about missing information. Possible strategies for inference include (1) interpolation, (2) extrapolation, (3) repeating the nearest value, (4) repeating the previous value, (5) patient-specific mean values, (6) patient-specific linear regression over time, (7) disease-specific mean values, (8) normal values, and (9) linear regression of correlated co-recorded variables. This study analyzes these strategies in a time-oriented data bank of patients with systemic lupus erythematosus, demonstrating that more accurate inferences of missing data are obtained when (1) strategies are tailored to the characteristics of the individual variable, (2) time-oriented strategies (e.g., interpolation) rather than non-time-oriented strategies (e.g., disease mean) are incorporated, (3) a ranked set of strategies is incorporated in a hierarchical stepwise fashion, and (4) the degree to which missing data are "nonrandomly" missing is assessed to allow estimation of bias. Interpolation is the best single technique with these data while linear regression of correlated co-recorded variables is a relatively weak technique. Inferences made by these hierarchical time-oriented approaches show significantly smaller mean differences from the actual values than do results from typical statistical package strategies.

Data Interpretation, Statistical↗
PubMed1991

Clomipramine test: serum level determination in three groups of psychiatric patients.

Concentrations of clomipramine, a specific and potent serotonin uptake inhibitor, are measured in 67 psychiatric patients and 12 normal volunteers. The psychiatric patients are grouped according to the DSM III R criteria namely; pathological gamblers, obsessive compulsives and sufferers of panic disorders. Before and 30, 60, 90 and 120 min after an intravenous infusion of the drug (12.5 mg in 10 min), serum samples are collected to evaluate the concentrations of cortisol, prolactine and growth hormone. Simultaneously the clomipramine concentration of these samples is determined and these results only are reported in this communication. Very different drug concentrations are observed in individual patients receiving the same amount of drug, indicating a substantial inter-individual variability of drug metabolism. No statistical differences (Newman-Keules test) between the clomipramine concentrations from the patients of the three psychiatric groups and the normal group are observed. Neither are statistical correlations observed when clomipramine concentrations from all individuals (n = 79) are related with the age, sex or consumer behaviour (cigarette smoking, alcohol and coffee intakes) of the patients.

Adolescent↗