Applying latent growth curve modeling to the investigation of individual differences in cardiovascular recovery from stress

OBJECTIVE

This paper provides an introduction to latent growth curve (LGC) modeling, a modern method for analyzing data resulting from change processes such as cardiovascular recovery from stress. LGC models are superior to traditional approaches such as repeated measures analysis of variance and simple change scores.

METHODS

The basic principles of LGC modeling are introduced and applied to data from 167 men and women whose systolic blood pressure was assessed before, during, and after the cold pressor and evaluated speech stressors and who had completed the Cook-Medley Hostility Inventory.

RESULTS

The LGC models revealed that systolic blood pressure recovery follows a different nonlinear trajectory after speech relative to the cold pressor. The difference resulted not from the initial decline at the completion of the stressor, but from higher levels at the end of the stressor and slower rate of change in decline for the speech. Hostility predicted the trajectory for speech but not for cold pressor. This relationship did not differ as a function of gender, although men had larger systolic blood pressure responses than women to both stressors.

CONCLUSIONS

LGC modeling yields an understanding of the processes and predictors of change that is not attainable through traditional statistical methods. Although our application concerns cardiovascular recovery from stress, LGC modeling has many other potential applications in psychosomatic research.

1,25-Dihydroxyvitamin D3 inhibits thyroid hormone-induced osteocalcin expression in mouse osteoblast-like cells via a thyroid hormone response element

Thyroid hormones are important regulators of bone development and metabolism. We have demonstrated that tri-iodothyronine (T3) increased and 1,25-dihydroxyvitamin D3 (1,25D3) attenuated the T3-stimulated expression of osteocalcin (OCN) in the osteoblast-like cell line MC3T3-E1. By means of transfection of promoter-reporter gene constructs we investigated the basal and the regulated transcription of this gene by both hormones. We found that a 0.67 kbp and a 1.3 kbp fragment of the mouse OCN OG2 promoter containing two Runx2 binding sites were significantly more active than a smaller fragment containing only one Runx2 binding site. The longer promoter fragments showed a higher reporter gene expression when the transfected cells were treated with 10(-7) M T3. This expression was attenuated by 1,25D3 dose-dependently. These fragments contain a sequence homologue to the recently identified binding site for the 1,25D3 receptor (VDR) in the rat OCN promoter. Deletion of a part of the promoter containing this VDR response element-like sequence (VDRE) resulted in a higher basal expression but abrogated the regulation by T3 and 1,25D3. Electrophoretic mobility shift assays revealed that the deleted sequence was able to bind both in vitro-translated chicken thyroid hormone receptor (TR) and proteins from nuclear extracts that reacted with an antiserum against TR. From these data we conclude that the VDRE-like sequence of the OG2 promoter contains a thyroid hormone response element.

[Parent-child relationship in families with liver-transplantated infants]

Due to progress in transplantation medicine and especially thanks to the possibility of transplantation of a liver lobe from a living donor - usually one parent - even very small children with end-stage liver diseases are transplanted nowadays. But there is little research on how parents cope with this specific situation facing the death of their baby without transplantation during the period of transition to parenthood, how family-relationships and bonding develop after transplantation, how the infants develop mentally and emotionally and what specific psychosocial help these families would need to prevent future problems. Stimulated by clinical experiences with families with liver-transplanted infants, a pilot study with families before liver-transplantation was conducted. The aim of the study was to determine methods of infant research suitable for this clinical population. Based on case-vignettes of the interviews and the clinical work with these families, questions as to transition to parenthood, bonding and liver-transplantation by donation of a lobe of one parent's liver are discussed.

Antifibrinogen IgG, fibrinogen, and Clq complexes circulating in a hypodysfibrinogenemic proband. Isolation, stoichiometry, and partial characterization

Circulating antifibrinogen antibodies have been reported in rare afibrinogenemic propositi, apparently occurring following fibrinogen replacement therapy, but immune complexes have not been described. In this report we describe circulating immune complexes formed by a monoclonal antifibrinogen IgG in a heterozygous hypodysfibrinogenemic (A alpha 16 Arg-->Cys) proband. Estimated by partial protein sequence and by other analyses, each immune complex consisted of one fibrin(ogen), one C1q, and 3-4 IgG molecules. The complexes were cryoprecipitable, a property also displayed by mixtures of proband IgG and normal fibrinogen. Indicating that both D and E domains were necessary for this behavior, cryoprecipitability was abolished by preincubation of the isolated IgG with either isolated normal fibrinogen fragment D100 or E. Consistent with the crossreactivity of the IgG with normal and mutant fibrinogen, the results suggest that the primary epitope resides on a D-E locus on the fibrin polymer formed by normal and abnormal molecules containing the uncleaved (or mutant) peptide A.

Influence of Iodixanol-270 and Iopentol-150 on the microcirculation in man: influence of viscosity on capillary perfusion

PURPOSE, MATERIAL AND METHODS: The aim of this study was to investigate the influence of direct intraarterial application of the contrast agents Iodixanol-270 and Iopentol-150 on the capillary perfusion. This was accomplished through continuous recording of the capillary perfusion in the nailfold capillaries of the right hand before and after a bolus injection of 20 ml of contrast agent into the right axillary artery.

RESULTS

After injecting 20 ml of Iodixanol-270, which has a high viscosity compared to the plasma viscosity, a statistically significant decrease in the erythrocyte velocity of 60.8% from 0.439+/-0.273 mm/s to 0.172+/-0.090 mm/s was observed already 10 s after the injection (p = 0.0001). The decreased velocity was maintained until the end of the observation period of 6 min. In contrast to this finding, no change in the erythrocyte velocity was observed after injection of 20 ml of the low-viscous Iopentol-150 (p = 0.1508).

CONCLUSIONS

The erythrocyte velocity in cutaneous capillaries therefore strongly depends on the viscosity of the contrast agent.

Relation between aerobic capacity and extent of myocardial ischemia in patients with normal cardiac function

BACKGROUND

The relation between aerobic capacity and extent of exercise-induced myocardial ischemia has not been investigated. Fifty patients with coronary artery disease (>/=50% stenosis) without myocardial infarction underwent cardiopulmonary exercise testing followed by quantitative thallium perfusion imaging. Results were compared with those of age- and sex-matched healthy controls with a low likelihood of coronary artery disease. Patients with Q-wave infarction, pulmonary disease, and peripheral vascular disease were excluded. Cardiopulmonary exercise testing and thallium perfusion imaging parameters were correlated for extent of global ischemia, occurrence of increased pulmonary thallium uptake, and transient ventricular dilatation during exercise.

RESULTS

Patients with global ischemia <20% (group 1, n = 25) had normal cardiopulmonary exercise testing results, similar to the control group, except for workload and maximal predicted heart rate, which were reduced. However, patients with ischemia >/=20% (group 2, n = 25) had poor cardiopulmonary exercise testing results compared with the controls. The ventilatory anaerobic threshold showed the most significant decrease of all cardiopulmonary exercise testing parameters (48% +/- 6% vs 57% +/- 6%, P <.0001), and it was the only parameter to correlate with extent of ischemia (r = -0.5; P <.003) as well as frequency of increased pulmonary uptake and transient ventricular dilatation (r = -0.33, P =.03).

CONCLUSIONS

Ventilatory anaerobic threshold is significantly related to extent of myocardial ischemia and signs of heart failure during exercise. However, patients with mild to moderate exercise-induced ischemia may have normal cardiopulmonary exercise testing performance.

Modulation of cytokine-induced expression of secretory phospholipase A2-type IIA by protein kinase C in rat renal mesangial cells

Renal mesangial cells express the 14 kDa secretory phospholipase A2-type IIA (sPLA2-IIA) in response to interleukin-1beta (IL-1beta). In order to understand the regulation of cytokine-induced sPLA2-IIA induction in more detail, we investigated whether phorbol ester-activated protein kinase C (PKC) has an influence on the IL-1beta-induced expression of sPLA2-IIA. We found that treatment of mesangial cells with the biologically active phorbol 12-myristate 13-acetate (PMA) and phorbol 12,13-dibutyrate inhibited IL-1beta induction of sPLA2-IIA mRNA, protein, and activity, whereas the inactive compound 4alpha-phorbol 12,13-didecanoate was without effect. An 8-hr pretreatment with PMA, which led to down-regulation of PKC-alpha and -delta isoenzymes, still inhibited sPLA2-IIA induction. Only after down-regulation of PKC-epsilon isoenzyme by 24-hr preincubation with PMA were we able to reconstitute the IL-1beta-induced sPLA2-IIA expression. Thrombin as a physiological activator of PKC in mesangial cells exerted similar effects as PMA and inhibited sPLA2-IIA expression. The selective PKC inhibitor calphostin C potentiated IL-1beta induction of sPLA2-IIA mRNA levels and partially reconstituted the thrombin-induced inhibition of sPLA2-IIA mRNA and activity. These data show that IL-1beta induction of sPLA2-IIA can be modulated by PKC and that the epsilon-isoenzyme of the PKC family is the most likely candidate mediating the suppression of cytokine-induced sPLA2-IIA expression in mesangial cells.

Effect of a prefabricated anterior bite stop on electromyographic activity of masticatory muscles

STATEMENT OF PROBLEM

Patients are often treated for signs and symptoms in the masticatory musculature, which may be manifested as pain and/or conditions that cause difficulty in recording jaw relation records. A quick, easy method to alleviate these signs and symptoms would be helpful.

PURPOSE

This study measured the effect of a prefabricated anterior bite stop on the electromyographic activity of the anterior temporalis, posterior temporalis, masseter and anterior digastric during clenching, and grinding tasks.

MATERIAL AND METHODS

A prefabricated anterior bite stop was fabricated for 30 randomly selected subjects. Electromyographic surface electrodes were placed on the right and left sides of these muscles. Electromyographic activity was measured during clenching and grinding both with and without the anterior bite stop.

RESULTS

The anterior bite stop had a significant effect in decreasing electromyographic activity for both clenching and grinding for all the tested muscles, except the anterior digastric.

CONCLUSIONS

For this patient population, the ready-made anterior bite stop reduced electromyographic muscle activity for the anterior and posterior temporalis and the masseter muscles during both clenching and grinding.

Dyadic psychotherapy for early relationship disorders: a case study

Specific treatment modalities, such as dyadic psychotherapies, have emerged, based on the notion that in cases of very early relational disorders, the patient is the parent-infant relationship. The aim of this paper is to present a case study of such a relational disorder which took place as the result of a complex interplay between the infant's biological risk factors and the parents' psychological risk factors. The emphasis is on the technique and the course of the dyadic psychotherapy of the mother and her three-year-old child, where the main goal was to change some of the intrapsychic and interpersonal processes specifically related to pathological motherhood. The theoretical background is briefly presented, while emphasizing the criteria for choosing one approach among the different kinds of dyadic psychotherapy.

Influence of radiographic contrast media (Iomeprol 350 versus Iopentol 350) on cutaneous microcirculation: single-center prospective randomized double-blind phase iv study in parallel-group design

OBJECTIVE

This single-center, prospective, randomized, double-blind phase IV study in parallel-group design was carried out to investigate whether either of two different x-ray contrast media (iomeprol 350 or iopentol 350) injected into the axillary artery has any influence on cutaneous microcirculation.

METHODS AND RESULTS

The investigation was carried out on two groups of patients (n = 10 in each group) who had to undergo a diagnostic heart catheter angiography. The confirmatory response variable for the study was the mean capillary erythrocyte velocity (mm/sec). Blood flow through the ipsilateral nail-fold capillaries was recorded continuously for 3 minutes before and 6 minutes after the injection of the randomly assigned x-ray contrast medium, and was evaluated off-line. A contrast medium-induced, rheologically determined disturbance of the microcirculation was found, which was due to two different effects. First, the high intrinsic viscosity (iopentol = 12.3 mPa.sec) led to an immediate reduction in capillary blood flow. This did not occur in the case of iomeprol (intrinsic viscosity = 7.5 mPa.sec). Second, the contrast medium molecules cause a morphological change in the erythrocyte membrane; echinocytes are formed and are further desiccated depending on osmolality of the contrast medium.

CONCLUSION

The time course of the conversion of erythrocytes into echinocytes leads to a maximum reduction in capillary erythrocyte velocity of 30 seconds after the bolus of contrast medium. For the more viscous contrast medium of higher osmolarity (iopentol), this led to a significant overall reduction of up to 48.6% in capillary blood flow (p < 0.0001) that lasted for up to 150 seconds, while iomeprol did not significantly affect capillary blood flow (p = 0.2759).

Syllabic strength and lexical boundary decisions in the perception of hypokinetic dysarthric speech

This investigation evaluated a possible source of reduced intelligibility in hypokinetic dysarthric speech, namely the mismatch between listeners' perceptual strategies and the acoustic information available in the dysarthric speech signal. A paradigm of error analysis was adopted in which listener transcriptions of phrases were coded for the presence and type of word boundary errors. Seventy listeners heard 60 phrases produced by speakers with hypokinetic dysarthria. The six-syllable phrases alternated strong and weak syllables and ranged in length from three to five words. Lexical boundary violations were defined as erroneous insertions or deletions of lexical boundaries that occurred either before strong or before weak syllables. A total of 1596 lexical boundary errors in the listeners' transcriptions was identified unanimously by three independent judges. The pattern of errors generally conformed with the predictions of the Metrical Segmentation Strategy hypothesis [Cutler and Norris, J. Exp. Psychol. 14, 113-121 (1988)] which posits that listeners attend to strong syllables to identify word onsets. However, the strength of adherence to this pattern varied across speakers. Comparison of acoustic evidence of syllabic strength to lexical boundary error patterns revealed a source of intelligibility deficit associated with this particular type of dysarthric speech pattern.

Pulmonary function threshold for distinguishing ventilatory- and nonventilatory-limited patients with airflow obstruction

Patients with chronic obstructive pulmonary disease (COPD) may demonstrate great variability between results on the pulmonary function test (PFT) compared to those on the cardiopulmonary exercise test (CPXT). The purpose of this study was to correlate PFT and CPXT indices and to identify PFT threshold values for predicting exercise capacity in patients with airflow limitation. Fifty-seven patients (48 men and 9 women) of mean age 66.4 +/- 4.8 years with COPD and 40 age-matched control patients underwent PFT and CPXT. Based on the CPXT results, the patients were divided into ventilatory-limited (VL) and nonventilatory-limited (NVL), and the findings were correlated with the PFT indices. Linear regression analysis was used to determine the relationship between dyspnea index (VEmax/MVV) and forced expiratory volume in one second (FEV1). The cutoff value for VL was FEV1 < 38% and for NVL FEV1 > 68%. The prominent limiting symptom (61%) in the VL group was dyspnea sensation, with leg discomfort presenting in only 14%; corresponding rates in the NVL group were 38% and 31%. We conclude that the FEV1 is a reliable index for distinguishing VL from NVL COPD patients during CPXT at two extremes: below 38% of the predicted value (VL) and above 68% of the predicted value (NVL).

How children reason about ability from report card grades: a developmental study

Elementary school students were interviewed to see how they reason about ability in the context of report card grades. Eighty-four 2nd, 4th, and 6th graders were presented with hypothetical children's report card grades for performance and effort and were asked to compare the children's "smartness." Four age-related levels of reasoning about ability were identified, in accordance with findings from past research. However, 6th graders did not use the expected highest levels of reasoning, which involve covariation of performance and effort information; rather, their reasoning emphasized the efficacy of effort. Reasons for differences between the present and previous findings are discussed.

Effect of controlled exercise training in coronary artery disease patients with and without left ventricular dysfunction assessed by cardiopulmonary indices

Cardiopulmonary indices were used to evaluate the effect of controlled exercise training prescribed on the basis of the heart rate at the ventilatory anaerobic threshold in coronary artery disease patients with and without impaired left ventricular function. Fifty-two patients aged 38-75 years were divided into four groups. The first three groups included patients with a left ventricular ejection fraction of > 45% at rest, as follows: group 1, 10 patients with single-vessel disease; group 2, 12 patients with two-vessel disease; group 3, 10 patients with three-vessel disease. Group 4 comprised 20 patients with left ventricular dysfunction (ejection fraction < 35%). The left ventricular ejection fraction was assessed by multigated acquisition radionuclear study. All patients underwent a cardiopulmonary exercise test before and after the program which lasted 6-9 months. The variables measured were oxygen consumption (VO2), CO2 output, minute ventilation, O2 pulse, and ventilatory anaerobic threshold. Significant improvements in maximal VO2, maximal O2 pulse, and ventilatory anaerobic threshold level were observed in groups 1, 2, and 4 (p < 0.1-0.0001), but not in group 3. These findings indicate that the overall cardiac function, as evaluated by cardiopulmonary indices, improves in patients with one- or two-vessel disease with good left ventricular function and in patients with impaired left ventricular function following an exercise training program. Severe coronary disease seems to limit improvement, even in the presence of a good left ventricular function. The results validate the heart rate at the ventilatory anaerobic threshold as the optimal training heart rate in coronary artery disease patients and the cardiopulmonary exercise test as a sensitive tool for evaluating exercise training results.

[Flow rates of roentgen contrast media of different viscosity in 4.1 Charrière coronary catheters]

The studies presented here investigated the obtainable flows of different contrast media (Iopromide 370 mg iodine/ml, ZK 119 095 370 mg iodine/ml, ZK 139 129 370 mg iodine/ml, Iopamidol 370 mg iodine/ml, Iopromide 300 mg iodine/ml, ZK 119 095 300 mg iodine/ml, ZK 139 129 300 mg iodine/ml, Iopamidol 300 mg iodine/ml, aqua dest.) in 4.1 Charrière coronary catheters. The measurements of the flow achieved by a standardised power of 100 N show that the highest values are reached with the substance ZK 119 095 (both for 300 mg iodine/ml and 370 mg iodine/ml). On comparison of the catheter types there are no differences in the delivery rate. The x-ray contrast-media, however, are significantly different: the lowest iodine delivery rate is found for iopromide 370 with 384.5 mg iodine/s; the highest rate for the test substance ZK 119 095 with 648.9 mg iodine/s. Although contrast media with low viscosity contain considerably less iodine/ml it is possible to achieve an iodine density in coronary vessels by about 86% higher than that achieved by contrast media with 370 mg iodine/ml. Therefore, the possibility to choose a viscosity-adapted x-ray contrast-medium allows the use of very thin cardiac catheter systems without leading to a worsening of picture quality.

Influence of a non-ionic radiography contrast medium on the microcirculation

PURPOSE, MATERIAL AND METHODS: Microcirculatory disturbances may be responsible for some of the adverse effects induced by contrast media. The influence of iopromide 370 (Ultravist) on cutaneous microcirculation was therefore investigated in 15 patients in a prospective study. Twenty ml of iopromide and 20 ml 0.9% NaCl were injected as reference in the subclavian artery at the beginning of a diagnostic coronary angiography. Erythrocyte velocity was measured in ipsilateral nailfold capillaries at the beginning of, during, and after the injection continuously up to 6 min after injection.

RESULTS

On average, 30 s after injection of contrast medium, erythrocyte velocity decreased significantly by 51.3% (p<0.0001) and remained reduced up to 120 s. This reaction was observed in 14 out of 15 patients. Three patients showed a temporary cessation of capillary blood flow.

CONCLUSION

The adverse effects sometimes seen during coronary angiography can be explained if similar contrast medium induced microcirculatory disturbances in the myocardial vasculature.

[The flow of contrast media in coronary catheters: study of the structural quality in interventional cardiology]

In the present study we investigated the contrast medium flow in 8 different types of left heart catheter having two different diameters (each n = 5). Using a 10 ml syringe and the contrast medium Ultravist 370, we calculated a mean value of 94.24 N + 16.01 for the maximum manual injection force in 18 test subjects. For the sake of simplicity, the figure of 100 N was defined as standardized manual force (which is within the standard deviation). If the maximally admissible static pressure of 82.5 bar is not to be exceeded, flow rates of not more than 16-17 ml/s are possible with 5.2 Fr. catheters, and 21-23 ml/s and 1.46 ml/s for 5.2 Fr. catheters, and between 1.99 ml/s and 2.17 ml/s for 6 Fr. catheters. Thus, a 50% higher flow can be achieved with 6 Fr. catheters as compared with 5.2 Fr. catheters at the same injection force. The iodine delivery rates are between 506 mg iodine/s and 539 mg iodine/s for 5.2 Fr. catheters, and between 738 mg iodine/s and 804 mg iodine/s for 6 Fr. catheters. The figures for the jet stream.

Hypervolemic hemodilution with or without venesection in peripheral arterial occlusive disease stage II

Patients with peripheral arterial occlusive disease (PAOD) and marked atherosclerosis often present concomitant diseases like coronary heart disease, cerebral circulatory disorders or arterial hypertension. Thus, the extent of hypervolemia is limited in case of an infusion treatment without venesection. Therefore, it was tested whether a hypervolemic hemodilution without venesection is superior to a dilution with venesection in multimorbid patients suffering from PAOD stage II. The colloidal iso-molar solution used was Haes 200/0.5 6%. Both forms of hemodilution were significantly superior compared to a control group well hydrated with cristalloid saline solution; all groups practised walking exercise twice a week over a period of one hour. However, hypervolemic hemodilution without venesection was only slightly better than the dilution with venesection. The walking distance in the group without venesection increased by 68.6 m (36.7%) in the group without venesection, by 59.0 (30.4%) in the group with venesection and by 33.6 m (20.1%) in the control group. The results show that the decision to perform a hyperor isovolemic hemodilution should depend on the volume tolerance of each patient.

Inhibitor-resistant tissue-type plasminogen activator: an improved thrombolytic agent in vitro

Platelet-rich clots are inefficiently lysed by current fibrinolytic agents. Platelets contain a great deal of plasminogen activator inhibitor 1 (PAI-1), the principal endogenous inhibitor of tissue-type plasminogen activator (t-PA). We have tested whether PAI-1 resistant t-PAs would be more effective thrombolytic agents in an in vitro model of platelet-rich clots. Clots were formed with recalcified human plasma without or with the addition of platelets. The lysis of these clots was followed by the release of incorporated 125I-fibrinogen. Mutant and wild-type t-PA were almost equally effective against clots lacking platelets but the mutant was twice as effective at lysing platelet-rich clots. A mechanism for this effect is suggested by the demonstration that a complex between wild-type t-PA and extruded platelet contents resembles that between purified t-PA and PAI-1 and that the PAI-1 resistant t-PA does not interefer with formation of this adduct. Because of its enhanced ability to lyse platelet-rich clots in vitro, further in vivo work may find that PAI-1 resistant t-PA is a more efficacious therapeutic agent than wild-type t-PA in situations where platelets contribute to the failure of thrombolysis.