Health related quality of life in stem cell transplantation: clinical and psychometric validation of the questionnaire module, High Dose Chemotherapy (HDC-19)

The objective of this study was to assess the psychometric properties of the HDC-19, a module questionnaire for assessing symptoms and problems of patients undergoing stem cell transplantation (SCT) following high-dose chemotherapy (HDC). It consists of 19 questions and was developed for use in conjunction with EORTC QLQ-C30. Psychometric evaluations were performed according to guidelines recommended by the EORTC. The principal component analyses suggested that nine of the HDC-19 items could be reduced to four components (sexual functioning, future health perspectives, skin irritations and joint/muscle pain). Multitrait scaling analysis showed that most item-scale correlation coefficients met the standards of convergent (>0.40) and discriminant validity. Test-retest reliability coefficients between assessments at inclusion and admission were high, indicating that perceived health status remained virtually unchanged during this period. As expected, correlations between admission and one month after transplantation were considerably lower. The internal consistency of the multi-item scales was also satisfactory, (Cronbach's alpha 0.59-0.87). Overall, the known-groups comparisons showed smaller differences between designated groups than expected. As expected, changes in the HDC-19 mirrored changes in QLQ-C30 'global quality of life'. These results lend support to the validity of the HDC-19 as a supplementary questionnaire for assessing specific health-related quality of life (HRQOL) issues relevant for SCT patients.

The development of emotional distress in 158 patients with recently diagnosed rheumatoid arthritis: a prospective 5-year follow-up study

OBJECTIVES

To describe the development of emotional distress among patients with newly diagnosed rheumatoid arthritis (RA), and to explore for early predictors of elevated distress over time.

METHODS

The study group consisted of 158 early RA patients (64% females) with mean age of 51.4 (SD = 12.7) years at disease onset. The patients were evaluated once a year for up to at least 4 years after baseline. Emotional distress was measured with the Symptom Checklist (SCL-90), disability with the Health Assessment Questionnaire (HAQ), pain with a visual analogue scale (VAS), and disease activity by an active joint count and erythrocyte sedimentation rate (ESR). Questions concerning social support were also included.

RESULTS

Emotional distress decreased slowly for a majority of the patients. The change reached statistical significance in the third year from study start. A minority (12%) showed continuously high and increasing levels of distress. Measures of disease activity were poor predictors of distress. The best predictor of distress over time was distress at baseline. Other predictors were gender, age, civil status, and social support.

CONCLUSIONS

Emotional distress tended to decrease for most patients in this cohort, but a minority showed continuously high levels. Patients at higher risk of developing emotional distress over time had higher levels of distress at baseline, were younger, more often female, and cohabiting, and experienced less social support.

Health-related quality of life in COPD: why both disease-specific and generic measures should be used

Although research has consistently demonstrated that chronic obstructive pulmonary disease (COPD) impairs health-related quality of life (HRQL), little agreement has been evidenced regarding the factors identified as contributing to impaired HRQL. The aim was to study such factors using well established generic and specific HRQL instruments. The patients (n=68) were stratified by forced expiratory volume in one second (FEV1) to represent a wide range of disease severity. Pulmonary function, blood gases and 6-min walking distance test (6MWD) were assessed. HRQL instruments included: St George's Respiratory Questionnaire (SGRQ), Sickness Impact Profile (SIP), Hospital Anxiety and Depression Scale and Mood Adjective Check List. The strength of the impact of COPD on HRQL was represented along a continuum ranging from lung function, functional status (physical and psychosocial) to wellbeing. Although correlations between FEV1 versus SGRQ total and SIP overall scores (r=-0.42 and -0.32) were stronger than previously reported, multiple regression analyses showed that lung function contributed little to the variance when dyspnoea-related limitation, depression scores and 6MWD were included in the models. These three factors were important to varying degrees along the whole range of HRQL. Physiological, functional and psychosocial consequences of chronic obstructive pulmonary disease are only poorly to moderately related to each other. The present study concludes that a comprehensive assessment of the effects of chronic obstructive pulmonary disease requires a battery of instruments that not only tap the disease-specific effects, but also the overall burden of the disease on everyday functioning and emotional wellbeing.

Obesity-related coping and distress and relationship to treatment preference

OBJECTIVES

The primary purpose was to define obesity-related strategies for coping with psychological problems connected with obesity. We also wanted to identify obesity-related distress and explore the effect of coping on distress. Thirdly, we wanted to investigate differences in coping and distress related to choice of surgery or conventional treatment.

DESIGN

Cross-sectional data from patients in the Swedish Obese Subjects (SOS) intervention study.

METHODS

An obesity-related questionnaire concerning coping and distress was created and evaluated in 2510 patients from the SOS study, using multitrait, exploratory and confirmatory factor analysis procedures.

RESULTS

Three coping factors were defined. Social Trust and Fighting Spirit were problem-focused, whereas Wishful Thinking was emotion-focused. Surgical candidates displayed lower levels of problem-focused and higher levels of emotion-focused coping. We also identified two distress factors: Intrusion and Helplessness. Wishful Thinking was positively related to distress, and Social Trust and Fighting Spirit were inversely related, thus explaining the higher levels of distress reported by the surgical candidates.

CONCLUSIONS

In our sample, emotion-focused coping proved maladaptive and was associated with increased distress. Problem-focused coping, however, was adaptive and associated with reduced distress. These findings partly explain psychological morbidity and should be taken into consideration in the treatment of obese people.

A qualitative study of stress factors in the early stage of acute traumatic hand injury

The aim of the study reported in this paper was to identify stress factors in the early stage of acute traumatic hand injury. Stress factors were defined as circumstances which the hand-injured patients experienced as problems in the actual situation. A total of 20 patients, treated as inpatients at the Department of Hand Surgery in Orebro Medical Centre Hospital, Sweden, were interviewed 8-20 days after the day of the accident. The analyses of the interviews followed the first step in the analytical process described in a modified model of grounded theory. The trauma experience was one of the stress factors in the early stage. Single acute traumatic stress symptoms, mostly involuntary recollection and re-experience of the trauma, were found in a fourth of the hand-injured patients. All patients reported impaired functioning caused by their hand, irrespective of injury. Practical problems with daily activities and being dependent on help from others for solving practical problems were stress factors caused by functional impairment. Before the accident most of the hand-injured had been very active, also working a lot with their hands in their leisure-time. Involuntary inactivity was a big problem for some of them. Other stress factors in the early stage were uncertainty about function in the future and pain. The appearance of the hand was a minor problem before the first follow-up visit. Probably because the hand was hidden in a bandage. However, some hand-injured felt discomfort in seeing the hand when the dressing was changed at the first follow-up visit.

Psychometric properties and factor structure of the Three-Factor Eating Questionnaire (TFEQ) in obese men and women. Results from the Swedish Obese Subjects (SOS) study

OBJECTIVE

To evaluate the construct validity of the Three-Factor Eating Questionnaire (TFEQ) in obese men and women.

SUBJECTS

A total of 4377 middle-aged, obese subjects in the Swedish Obese Subjects (SOS) study.

METHODS

The total sample was randomly split into two data subsets and psychometric testing was performed separately in each sample. Multitrait/multi-item analysis was conducted to test scaling assumptions and factor analysis was used to test the factor structure. Measures of mental well-being (MACL, HAD) were used for testing criterion-based validity.

RESULTS

The Cognitive Restraint factor was consistently reproduced and scaling analysis demonstrated strong item-scale discriminant validity, while the item-scale convergent validity was unsatisfactory. The internal structure of the Disinhibition scale was weak. Most Disinhibition and Hunger items grouped in one global factor labeled Uncontrolled Eating. A third cluster containing items on Emotional Eating was also identified. The obtained three-factor structure was cross-validated and replicated across subgroups by gender, age and BMI.

CONCLUSION

The original TFEQ factor structure was not replicated. A short, revised 18-item instrument was constructed, representing the derived factors of Cognitive Restraint, Uncontrolled Eating and Emotional Eating. The most efficient items were used to boost both the convergent and discriminant validity of the scales.

Psychometric properties of the Swedish version of the Well-Being Questionnaire in a sample of patients with diabetes type 1

OBJECTIVES

The aim of the present investigation was to further test the psychometric properties of a Swedish version of the Well-Being Questionnaire (WBQ) in order to determine whether it could be suitable for measuring health-related quality of life among type 1 diabetic patients.

METHODS

In total, 94 patients who fulfilled the inclusion criteria were selected for the study and of these 85% participated. Reliability was tested with Cronbach's alpha coefficient and the internal validity by means of principal component analysis and multitrait analysis. To test the external validity, comparisons were made with two other questionnaires, the Short form-36 and a Swedish Mood Adjective Check List.

RESULTS

The results show that, above all, the Swedish version of the WBQ measures psychological well-being, and thus must also be complemented with scales that measure other consequences of the illness and/or treatment, i.e. physical symptoms. The questionnaire has low discriminatory validity between subscales, which casts doubt on the appropriateness of using the four subscales as separate measures. The two scales measuring anxiety and depression are not sensitive enough for use among type 1 diabetics without complications and high or normal levels of psychological well-being.

CONCLUSIONS

The Well-Being Questionnaire alone does not give any more information about subjective health status among type 1 diabetic patients than, for example, the generic SF-36.

Long-term effects of a pulmonary rehabilitation programme in outpatients with chronic obstructive pulmonary disease: a randomized controlled study

Fifty patients with severe chronic obstructive pulmonary disease (FEV1 < 50% pred.) were randomized to a rehabilitation group and a control group. The rehabilitation group took part in an individualized multidisciplinary, outpatient 12-month rehabilitation programme. Exercise training was intensive during the first 6 weeks and was then gradually replaced by an individual home-training programme and booster sessions. Controls received the usual outpatient care. Positive effects were found in terms of maximum symptom-limited exercise tolerance and walking distance (13.5 and 12.1% increase, respectively) in the rehabilitation group compared with the controls. Quality of life measurements showed minor beneficial effects on the Sickness Impact Profile, indicating a higher level of activity. No effect was seen on the St George's Respiratory Questionnaire or the Mood Adjective Check List. Patients expressed their enthusiasm for the rehabilitation programme in a study-specific questionnaire.

Psychological factors in chronic rheumatic diseases--a review. The case of rheumatoid arthritis, current research and some problems

An overview of studies relating psychological factors to perceived well-being among Rheumatoid Arthritis (RA) patients is presented. Most attention has been devoted to the perception of control, coping and the effects of cognitive distortions. The introduction of these constructs have advanced the understanding of psychological distress among RA patients, although they explain only a smaller part. One reason could be that they give an oversimplified picture of adjustment processes in chronic and disabling diseases. This may partly be because their development are based either on studies of depression in a psychiatric sense or on how healthy subjects manage stressful events in daily life. The results therefore have limited relevance for adjustment to a life-long, chronic illness like RA. Recent research has also suggested that personality dispositions, especially neuroticism, play a substantial role in all types of subjective experiences. Finally, some issues for future research are discussed.

Quality-of-life effects of psychosocial intervention in patients with head and neck cancer

METHODS

Two studies of psychosocial interventions in head and neck cancer patients at different stages of their disease were performed. We explored the feasibility and effectiveness of different approaches, offered for the first time to this population. The first study concerned long-term group psychological therapy for patients with newly diagnosed head and neck cancer. Quality of life was measured longitudinally for 1 year and compared with that of a control group. The second study comprised a short-term psychoeducational program 1 year after treatment for head and neck cancer. Quality-of-life assessments were made repeatedly from diagnosis until 1 month after the intervention.

RESULTS

Thirteen patients started the psychological group therapy, and 8 of them completed both the intervention and evaluation procedure. The quality of life of the therapy group improved more than that of a control group in most areas measured during the study year, in particular psychiatric morbidity, social functioning, emotional functioning, and global quality of life. The results indicate benefits from the therapy, although the therapy group scored worse than the control group at diagnosis. Most of the variables representing functioning and symptoms improved after the 1-week psychoeducational program, especially items reflecting "trouble eating" and "problems enjoying your meals." Patients' judgments of the intervention quality indicated satisfaction with all separate elements, mostly education, about cancer and the opportunity to socialize with the other guests.

CONCLUSION

These pilot studies suggest that head and neck cancer patients can benefit from different psychosocial interventions. Quality-of-life questionnaires were well accepted and sensitive to changes during the studies. Thus our early findings seem promising and would justify confirmation in larger studies.

The Swedish SF-36 Health Survey II. Evaluation of clinical validity: results from population studies of elderly and women in Gothenborg

The validity of the Swedish SF-36 Health Survey was examined, replicating techniques used in the U.S. validation. Principal components analysis was used to test the internal structure of the eight SF-36 scales in relation to hypothesized associations with the two major dimensions of health--physical and mental. Hypothesized relationships between scales and external criteria were also examined by means of clinical group contrasts. Both the principal components analysis and clinical group contrasts largely replicated U.S. findings, which supported the cross-cultural stability of the SF-36 in Sweden. As expected, the Physical Functioning and Mental Health scales were most sensitive to clinical manifestations of medical and mental health, respectively. The General Health scale was associated more with physical than mental health. However, the Social Functioning scale and particularly the Vitality scale were more related to mental health in Sweden than in the corresponding U.S. study. Cultural differences and variation in study samples and selection criteria were suggested as possible explanatory factors for these differences.

Reliability and validity of a Swedish version of the St George's Respiratory Questionnaire

The St George's Respiratory Questionnaire (SGRQ) was designed to measure quality of life (QoL) in obstructive pulmonary disease. Its reliability, validity and sensitivity have been demonstrated. The aim was to develop a Swedish version of the SGRQ and to confirm its scaling and clinical properties. The SGRQ was adapted for Swedish conditions following a translation-backtranslation procedure. The psychometric and clinical evaluation included 68 patients with chronic obstructive pulmonary disease (COPD). Supplementary QoL, clinical and physiological data were collected. A follow-up study was performed 1 yr later. Correlation analysis used a multitrait-multimethod model. Internal consistency reliability and discriminant validity were documented by performing a multitrait analysis. The results confirmed expected levels of associations. Correlation coefficients between the SGRQ total score and the Sickness Impact Profile Total score (a generic health measure), forced expiratory volume in one second (FEV1) and 6 min walking distance were 0.69, -0.42 and -0.61 respectively. The pattern of correlations in the Swedish data set was very similar to that of the original. The stability of the SGRQ scores was confirmed at follow-up after 1 yr. The reliability was satisfactory, with Cronbach's alpha coefficients >0.80 for the SGRQ and its subdimensions. In conclusion, the Swedish version of the St George's Respiratory Questionnaire is reliable, valid and compares well with the corresponding tests of the original version.

Importance and attainment of life values among disabled and non-disabled people

How do disabled persons evaluate their life situation? To address this issue, importance and attainment ratings of 82 different life values as well as mood ratings were collected from 325 chronically ill and/or disabled persons and 504 non-disabled persons. Both groups largely agreed on what is important in life. The disabled persons, however, gave lower importance ratings on functions related to health and mobility. The attainment and mood ratings were in general slightly lower for the disabled persons. The attainment ratings for health and mobility were markedly lower. The concordance between rated importance and attainment across different life values was positive in both groups. This measure was also positively related to mood in both samples. It was suggested that disabled persons adjust to their life situation by de-emphasizing the importance of the physical functions affected by the disability and through habituation.

Functional status and well being in chronic obstructive pulmonary disease with regard to clinical parameters and smoking: a descriptive and comparative study

BACKGROUND

Self-assessment questionnaires which measure the functional and affective consequences of chronic obstructive pulmonary disease (COPD) give valuable information about the effects of the disease and may serve as important tools with which to evaluate treatment.

METHODS

A cross sectional comparative study was performed between patients with COPD (n = 68), stratified according to pulmonary function, and a healthy control group (n = 89). A battery of well established clinical and quality of life measures (the Sickness Impact Profile (SIP), Mood Adjective Check List (MACL), and Hospital Anxiety and Depression scale (HAD)) was used to examine in which functional and affective aspects the patient group differed from the control group and how these measures related to pulmonary function and smoking habits.

RESULTS

Compared with the controls, COPD affected functional status in most areas, not just those requiring physical activity. Forty six patients with forced expiratory volume in one second (FEV1) below 50% predicted showed particularly high levels of dysfunction in ambulation, eating, home management, and recreation/ pastimes (SIP). Despite this, their level of psychosocial functioning and mood status was little different from that of the healthy controls. Among the patients, a subgroup reported substantial psychological distress, but mood status was only weakly, or not at all, related to pulmonary function. Smoking habits did not affect functional status or well being.

CONCLUSIONS

Quality of life is not significantly affected in patients with mild to moderate loss of pulmonary function, possibly due to coping and/or pulmonary reserve capacity. This suggests that generic self-assessment questionnaires are of limited value for detecting the early consequences of COPD. However, in later stages of the disease they are sensitive enough to discriminate between patients with different levels of pulmonary dysfunction. The low correlations between the indices of pulmonary function and the indices of affective status suggest that well being depends, to a large extent, on factors outside the clinical domain.

A structure of self-conceptions and illness conceptions in rheumatoid arthritis (RA)

In 2 independent samples of RA patients, a large pool of self-reported illness experiences were statistically examined for content and structure of common types of self-conceptions and illness conceptions related to living with rheumatoid arthritis (RA). Multivariate analyses revealed 7 primary factors in both samples. Three constituted a positive continuum (fighting spirit, acceptance, revaluation), and 3 a negative (deprivation of life values, protest, reserved). The 7th factor (denial) was weaker and conceptually intermediate. The obtained factors contained many items similar to those in other established psychological instruments used in research on RA, but showed stronger relations to subjective well-being (mood) than any one of these. Disease indicators correlated only weakly with RA self-conceptions (RASC) and mood. The RASC factors appear to more broadly reflect different facets of positive and negative ways of individual experience of living with RA than other published instruments. They were tentatively interpreted as RA-specific expressions of dispositions towards positive and negative affect, respectively.

Purification of the mitochondrial citrate transporter in yeast

We present a method of partial purification of mitochondrial citrate transporter of the yeast Saccharomyces cerevisiae. Based on functional evidence of interaction between citrate transport and citrate synthase, we have used an affinity column containing pig heart citrate synthase (PHCS) for the purification. The purified preparation shows two protein components whose Mr is approximately 50K and 60K. The specific activity of our purest fractions is 2.6 mumoles/min which compares favorably to that of purified beef liver enzyme and purified rat liver enzyme.

Immunological mapping of fine molecular surface structures of citrate synthase enzymes from different cell types

Citrate synthase (EC 4.1.3.7), which is present in all living organisms as a key enzyme in aerobic energy metabolism, is one of the most highly phylogenetically conserved enzymes known in terms of its primary and active site structure. However, in terms of other parameters such as in vitro stability, tolerance to changes in pH, degree of self-polymerization, etc., citrate synthases from different sources are markedly different. These divergences can be observed even between isoforms of the enzyme within the same species. Data documenting these diversities suggest that a high degree of difference in tertiary structures may occur. Therefore, the surface profiles of citrate synthase enzymes from yeast, pig, rat, tomato and Escherichia coli were investigated with immunological methods using monoclonal antibody families generated against either pig citrate synthase (alpha-PCS) or yeast citrate synthase-2 (alpha-YCS-2). A high degree of homology of enzyme epitopes was detected on the mitochondrial citrate synthases originating from yeast, tomato, pig and rat cells. Major differences were found between the hexameric citrate synthase originating from E. coli compared with those dimeric forms prepared from eukaryotic cells. Only modest similarities were detected between the highly homologous peroxisomal and mitochondrial yeast citrate synthases. Furthermore, a point mutation of one of the catalytic residues (H274R on recombinant pig and H313R on yeast enzyme) of mitochondrial citrate synthase (CS-1) resulted in a significant increase in immunological similarity with the peroxisomal isoenzyme (CS-2). These findings are discussed in terms of the possible mechanism of evolution of CS-2 in yeast.

Citrate synthase 1 interacts with the citrate transporter of yeast mitochondria

We have previously shown that citrate synthase binds to an intrinsic protein of the mitochondrial inner membrane (D'Souza and Srere, 1983). In this paper we present evidence that this citrate synthase binding protein is the citrate transporter. We have used citrate synthase 1 mutants of Saccharomyces cerevisiae and transformants containing citrate synthase inactivated by site-directed mutagenesis to study the effect of the CS1 protein upon mitochondrial function (Kispal and Srere). In the present study citrate uptake and oxidation were measured during state 3 conditions (presence of 200 microM ADP) in the mitochondria of several strains of Saccharomyces cerevesiae: a parental strain containing wild-type mitochondrial citrate synthase (CS1) and strains derived from a CS1 deficient strain in which the CS1 gene was disrupted by insertion of the LEU2 gene. These strains were generated from the CS1- cells by transformation with vectors encoding site-specific mutants of CS1 possessing very low levels of enzymatic activity. One such strain in this study was subsequently found to have undergone reversion to produce a strain which had activity very similar to wild type. Positive correlation between citrate uptake and the rate of citrate oxidation was found, suggesting coupling of the two processes. Both mitochondrial citrate uptake and oxidation were decreased in the mutant lacking any form of CS1 protein. Reintroduction of mutagenized CS1 into yeast causes an enhancement in the rate of state 3 oxygen consumption and of citrate uptake.(ABSTRACT TRUNCATED AT 250 WORDS)

Studies of protein-protein interaction using countercurrent distribution in aqueous two-phase systems: partition behavior of five glycolytic enzymes from crude baker's yeast extract

The partition behavior of five glycolytic enzymes, in extracts from baker's yeast (Saccharomyces cerevisiae), between two aqueous phases has been studied by countercurrent distribution. All enzymes showed distribution patterns which indicated homogeneity and a similar partition behavior. In purified form, three of the enzymes (glyceraldehyde-phosphate dehydrogenase, 3-phosphoglycerate kinase, and enolase) showed the same partition behavior as in the extracts. Pure 6-phosphofructokinase, on the other hand, changed its partition distinctively relative to what was found in the extracts. These results indicate interactions between this enzyme and macromolecular compounds in the extracts and support a model suggested by Kurganov et al. (1985, J. Theor. Biol. 116, 509-526) describing a "glycolytic particle."

Studies of protein-protein interaction using countercurrent distribution in aqueous two-phase systems. Partition behaviour of six Calvin-cycle enzymes from a crude spinach (Spinacia oleracea) chloroplast extract

The partition behaviour of six enzymes of the Calvin cycle in extracts of chloroplasts from spinach (Spinacia oleracea) between two aqueous phases has been studied by countercurrent distribution. The enzymes showed distribution patterns which indicate heterogeneity and the presence of two or three fractions of most of the enzymes. When two of the enzymes, phosphoglycerate kinase and fructose-bisphosphate aldolase, were partitioned in both purified and partially purified form, they behaved like homogeneous substances. These results indicate that countercurrent distribution of crude extracts in aqueous two-phase systems is a useful method to study protein-protein interaction.

Rapid purification of fructose-1,6-bisphosphate aldolase from spinach chloroplasts

A rapid procedure for the purification of fructose-1,6-bisphosphate aldolase from spinach chloroplasts is presented which involves two steps; precipitation of bulk protein with polyethylene glycol and partitioning of remaining soluble protein in aqueous two-phase systems. A 94% pure preparation is obtained within 6h with a yield of 19%. A marked difference in the partition behaviour of the aldolase activity from whole leaf tissue suggested that the procedure is less efficient when leaf extract is used as starting material.

Mood and somatic symptoms

The relations between subjective ratings of mood and somatic symptoms were examined in four studies. Correlational analysis revealed strong relations both between and within the different aspects of mood and somatic discomforts. It was also found that the more diffuse somatic discomforts showed the highest correlations with mood. A time-series analysis also revealed that the dominating explanatory factor was from current symptom reports to current mood reports and not vice versa.

Mood effects of diazepam and caffeine

Changes in mood after administration of Diazepam and Caffeine were analyzed. Six aspects were studied: pleasantness, activation, extraversion, calmness, social orientation and control. In addition to this check list, mood ratings using magnitude estimation of selected adjectives were obtained. It was found that Diazepam decreased feelings of activation and extraversion and increased calmness. Caffeine had no clear effects on the check list, but on the magnitude estimation scale some effects opposite to those of Diazepam were observed. Men reported a higher degree of pleasantness than women after administration of Diazepam. No differences in heart rate were found. Few distinct scale values were utilized on the magnitude estimation scale and the discriminative power was found to be larger for the check list than for the magnitude estimation scale.

Mood effects of alcohol

Doses of 0.41, 0.63, and 0.85 g alcohol/kg body weight were administered using a double-blind Latin square design to subjects who made mood ratings at seven points in time during 3h subsequent to administration. The subjects felt more euphoric and extraverted and less tense at mainly the highest dose levels. Lower dose levels tended to induce more negative feelings. Frequent consumers of alcohol derived greater affective benefit than rare drinkers. Intercorrelations between ratings of subjective intoxication and mood variables indicated that the meaning of the variable "subjective intoxication" was different for the three dose levels and for different points in time.