Reversible cardiomyopathies--a review.

End-stage renal disease, cirrhosis, obesity, tachycardia, and extreme stress have all been shown to result in impaired left ventricular function. It is becoming clear, however, that the cardiomyopathies associated with these states are reversible after resolution of the underlying process. In this article, we present the current data demonstrating that renal transplantation, liver transplantation, and bariatric surgery can lead to reversal of uremic, cirrhotic, and obesity cardiomyopathies, respectively. We also discuss the reversibility of tachycardia-induced cardiomyopathy after radiofrequency ablation or pharmacologic therapy for rate or rhythm control and the reversibility of stress-induced cardiomyopathy with supportive care.

Pharmacokinetics of remifentanil in anesthetized pediatric patients undergoing elective surgery or diagnostic procedures.

UNLABELLED: Remifentanil hydrochloride is an ultra-short-acting opioid that undergoes rapid metabolism by tissue and plasma esterases. We aimed to characterize the pharmacokinetics and determine the hemodynamic profile of remifentanil after a single-bolus dose in children aged 0 to 18 yr. Forty-two children undergoing elective surgical procedures received remifentanil 5 microg/kg infused over 1 min. Patients were divided into age groups as follows: young infants (< or =2 mo), older infants (> 2 mo to < 2 yr), young children (2 to < 7 yr), older children (7 to < 13 yr), adolescents (13 to < 16 yr), and young adults (16 to < 18 yr). Arterial blood samples were collected and analyzed by mass spectroscopy to determine remifentanil pharmacokinetic profiles. Hemodynamic measurements for remifentanil's effect were made after the infusion. Methods of statistical analysis included analysis of variance and linear regression, with significance at P < or = 0.05. Complete remifentanil pharmacokinetic data were obtained from 34 patients. The volume of distribution was largest in the infants < 2 mo (mean, 452 mL/kg) and decreased to means of 223 to 308 mL/kg in the older patients. There was a more rapid clearance in the infants < 2 mo of age (90 mL. kg(-1). min(-1)) and infants 2 mo to 2 yr (92 mL. kg(-1). min(-1)) than in the other groups (means, 46 to 76 mL. kg(-1). min(-1)). The half-life was similar in all age groups, with means of 3.4 to 5.7 min. Seven subjects (17%) developed hypotension related to the remifentanil bolus. Remifentanil showed an extremely rapid elimination similar to that in adults. The fast clearance rates observed in neonates and infants, as well as the lack of age-related changes in half-life, are in sharp contrast to the pharmacokinetic profile of other opioids. Remifentanil in a bolus dose of 5 microg/kg may cause hypotension in anesthetized children. IMPLICATIONS: The pharmacokinetics of remifentanil were studied in children from birth to 18 yr. Remifentanil was found to have age-related changes in clearance and volume of distribution, but not half-life. The increased clearance observed in young infants is in contrast to other opioids.

Oxygen-containing functional groups on single-wall carbon nanotubes: NEXAFS and vibrational spectroscopic studies.

Single-walled nanotubes (SWNTs) produced by plasma laser vaporization (PLV) and containing oxidized surface functional groups have been studied for the first time with NEXAFS. Comparisons are made to SWNTs made by catalytic synthesis over Fe particles in high-pressure CO, called HiPco material. The results indicate that the acid purification and cutting of single-walled nanotubes with either HNO3/H2SO4 or H2O2/H2SO4 mixtures produces the oxidized groups (O/C = 5.5-6.7%), which exhibit both pi*(CO) and sigma*(CO) C K-edge NEXAFS resonances. This indicates that both carbonyl (C=O) and ether C-O-C functionalities are present. Upon heating in a vacuum to 500-600 K, the pi*(CO) resonances are observed to decrease in intensity; on heating to 1073 K, the sigma*(CO) resonances disappear as the C-O-C functional groups are decomposed. Raman spectral measurements indicate that the basic tubular structure of the SWNTs is not perturbed by heating to 1073 K, based on the invariance of the ring breathing modes upon heating. The NEXAFS studies agree well with infrared studies which show that carboxylic acid groups are thermally destroyed first, followed by the more difficult destruction of ether and quinone groups. Single-walled nanotubes produced by the HiPco process, and not treated with oxidizing acids, exhibit an O/C ratio of 1.9% and do not exhibit either pi*(CO) or sigma*(CO) resonances at the detection limit of NEXAFS. It is shown that heating (to 1073 K) of the PLV-SWNTs containing the functional groups produces C K-edge NEXAFS spectra very similar to those seen for the HiPco material. The NEXAFS spectra are calibrated against spectra measured for a number of fused-ring aromatic hydrocarbon molecules containing various types of oxidized functional groups present on the oxidized SWNTs.

Weaver syndrome with neuroblastoma and cardiovascular anomalies.

We report on an infant with Weaver syndrome, neoplasia and cardiovascular anomalies. Stage 4S neuroblastoma underwent spontaneous resolution. Three neoplasms have been reported in Weaver syndrome: another stage 4S neuroblastoma [Muhonen and Menezes, 1990: J Pediatr 116:596-599], an ovarian endodermal sinus tumor [Derry et al., 1999: J Med Genet 36:725-728], and a sacrococcygeal teratoma [Kelly et al., 2000: Am J Med Genet 95:492-495]. No case was associated with cardiovascular anomalies. Our patient had VSD and PDA, and although several other patients with Weaver syndrome have had cardiovascular anomalies, they were shown not to have neoplasia.

Pharmacokinetics and pharmacodynamics of zolmitriptan in patients with mild to moderate hypertension: a double-blind, placebo-controlled study.

Zolmitriptan is a potent selective 5HT1B/1D receptor agonist for acute migraine therapy. Zolmitriptan has vasoconstrictor activity in cerebral vessels and may cause slight elevations of blood pressure in subjects without hypertension. Therefore, the pharmacokinetics and pharmacodynamics of zolmitriptan (5, 10, and 20 mg) were evaluated in 16 patients with mild to moderate hypertension (controlled by hydrochlorothiazide 50 mg once daily) and 17 healthy age- and sex-matched control subjects in a randomized, placebo-controlled, double-blind, four-period crossover study. The pharmacokinetics of zolmitriptan and its metabolites were dose proportional. Although area under the concentration-time curve (AUC0-infinity) and maximum concentration (Cmax) were slightly higher in patients with hypertension at all doses, this was only statistically significant for AUC at the 20-mg dose. Differences between subjects with and without hypertension were not clinically significant. Zolmitriptan produced a small increase in blood pressure, but this was similar in subjects with and without hypertension and was of no clinical significance. Zolmitriptan was well tolerated in both groups. Zolmitriptan plasma concentrations were higher in women than in men, with higher values of AUC and Cmax and lower total clearance in women. These results indicate that zolmitriptan can be administered for treatment of migraine in patients with controlled hypertension without dose adjustment.

Zolmitriptan (311C90) does not interact with fluoxetine in healthy volunteers.

Zolmitriptan (Zomig, formerly 311C90) is a selective 5-hydroxytryptamine (5-HT)1B/1D-receptor agonist with central and peripheral activity for the acute treatment of migraine. This randomized, placebo-controlled, crossover study investigated the effects of fluoxetine administration on the pharmacokinetics and pharmacodynamics of zolmitriptan. Twenty volunteers were given single doses of fluoxetine 20 mg or an identical placebo daily for 28 days prior to receiving a single 10 mg oral dose of zolmitriptan. Sixteen volunteers completed the two treatment phases. The pharmacokinetic parameters of zolmitriptan and its metabolites were not significantly affected by fluoxetine pretreatment. The pharmacodynamic effects of zolmitriptan were also unaffected by fluoxetine pretreatment. There were small, clinically insignificant increases in blood pressure following zolmitriptan which were unaltered by fluoxetine. Zolmitriptan was well tolerated when given alone or concomitantly with fluoxetine. These results indicate that there is no contraindication to the use of zolmitriptan in patients treated concurrently with selective serotonin reuptake inhibitors and that no adjustment of the zolmitriptan dose is required in these circumstances.

The nurse-technology relationship: the case of ultrasonography.

OBJECTIVE: To examine the nurse-technology relationship via a case study of ultrasonography in women's health nursing practice. DESIGN: Exploratory case study using ethnographic methods. SETTING: Outpatient obstetric and gynecology clinic of a large teaching hospital. PARTICIPANTS: Three nurses, two technicians, and one physician. RESULTS: Two of the nurses and the physician were very "nurse-like" in their use of the technology of ultrasonography to fulfill the traditional nursing purposes of observation, teaching, and comforting. The third nurse was nurse-like in talk, but at times "technician-like" in performance, allowing the technology to pull her away from nursing purposes. CONCLUSIONS: The expert nurses bent the technology to nursing purposes. Sonographers performed in accordance with professional training and experience, rather than with gender expectations. The subtle differences between expert nurse use and technical use (by novice nurses or technicians) of ultrasonography may provide a strong rationale against current efforts to substitute technically trained or technically oriented personnel for expert nurses.

Early transvaginal ultrasound following an accurately dated pregnancy: the importance of finding a yolk sac or fetal heart motion.

Our goals were to determine the prognostic value of a yolk sac or fetal heart motion seen during an early accurately dated transvaginal ultrasound (TVU). We reviewed 225 consecutive pregnancies for fetal heart motion data. Furthermore, 63 pregnancies following in-vitro fertilization were reviewed for yolk sac information. The TVU was performed between 5 and 6 weeks following presumed conception (heart motion data) and between 22 and 32 days following in-vitro fertilization (yolk sac data). Pregnancies were followed until an ongoing pregnancy or spontaneous abortion was documented. The presence of a yolk sac between 22 and 32 days from fertilization was associated with the development of fetal heart motion in 94% of cases. The absence of the yolk sac by 32 days after fertilization was always associated with a poor outcome. In women < 36 years of age, the presence of fetal heart motion was associated with a spontaneous abortion in only 4.5% of the cases. However, the incidence of spontaneous abortion following fetal heart motion increased to 10% in women 36-39 years and 29% in women > or = 40 years of age. The presence of heart motion should not be considered a reassuring sign in the older woman. These data have implications regarding early embryology and the counselling of infertility patients.

Autobiographical recall and visual imagery.

If high visual imagery is a component of successful autobiographical recall for personal episodes, then those participants who have high imagery should have greater autobiographical recall for personal episodes. This hypothesis was tested by giving 30 selected participants, 15 who had high and 15 low visual imagery, 90 sec. to recall personal episodic information from three time periods in their lives. Also assessed were the effects of visual imagery on autobiographical recall for personal semantic and nonpersonal semantic information (vegetables and adjectives). Level of visual imagery was significantly related only for the group with lower visual imagery, who recalled more adjectives. The implications of the results for the semantic and episodic memory distinction within autobiographical memory were discussed.

Pituitary response to early follicular-phase minidose gonadotropin releasing hormone agonist (GnRHa) therapy: evidence for a second flare.

PURPOSE: Our purpose was to determine the pituitary response to minidose follicular-phase GnRHa and see if a second flare can be achieved. METHOD: A prospective, consecutive series of 12 couples with tubal-factor infertility underwent 14 cycles of minidose GnRHa. Women were given a 25- or 50-migrograms dose of leuprolide acetate (LA) on cycle days 2 and 5. On cycle days 3 and 4 no LA was given but 2 ampoules of pure follicle stimulating hormone (FSH) was administered. Beginning day 6, a combination of LA and FSH was administered. RESULTS: Following a dose of only 25 micrograms of LA on cycle day 2, mean FSH, LH, and E2 levels were significantly elevated over the baseline levels. Following no LA on cycle day 3 or 4, a repeat dose of 25 micrograms LA caused a second flare of LH and E2 on cycle day 6. Of the 14 cycles, 6 were canceled because of poor stimulation. Two of the eight patients who underwent retrieval delivered a live birth. CONCLUSIONS: This is the first study to examine both the pituitary response and the recovery time from minidose follicular-phase GnRHa. An extremely small dose of LA is needed to cause a pituitary flare of gonadotropins. Following a flare from 25 micrograms of LA on cycle day 2, the pituitary is able to recover and respond with a repeat flare on cycle day 5.

Why are there sometimes concreteness effects in memory for prose?

Four experiments explored on-line encoding strategies and memory for high imagery and low imagery texts. Results consistently indicated that concreteness effects in memory for text depend on how materials are presented in several different respects. Most importantly, the experiments clarified apparently contradictory results of previous studies by indicating that concreteness effects generally do not occur in memory for prose when imageability is manipulated between-subjects, and that their occurrence when imageability is manipulated within-subjects depends on the order occurrence when imageability is manipulated within-subjects depends on the order of presentation. In addition, moving window analyses of text processing strategies indicated that differential strategies observed in previous studies when subjects listened to high vs low imagery text do not generalize to reading of the same materials. Potential explanations for the pattern of results are evaluated, and implications for theories of mental imagery and memory are considered.

Smoking health risk. Counseling of psychiatric patients.

1. Cigarette smoking has been identified as the single most important source of preventable morbidity and premature mortality in the United States for each of the past 25 years. Despite a smoking rate of 50% to 84%, persons with psychiatric illness have not been the target of any documented smoking health risk education in current literature. 2. Most nurses view smoking health risk education as a nursing function, but few actually provide this care for patients due to perceived ineffectiveness of health risk education, belief that smoking is not a health risk, and lack of knowledge base to provide the care. 3. Data from the study reported on in the article reflected that nurses were providing smoking health risk information to less than 50% of patients. Nurses were not identifying nicotine dependence as a nursing problem and therefore were making no plans to provide nursing interventions to resolve it.

Population pharmacodynamics of doxacurium.

The nonlinear mixed-effects modeling (NONMEM) computer program was used to investigate the variability in the duration of doxacurium-induced neuromuscular block in 408 patients enrolled in phase II and phase III clinical trials of doxacurium. Spontaneous recovery data in the 10% to 90% block range from all patients were pooled and fitted to a linear model. Two parameters were estimated: (1) the slope, which is related to the pharmacokinetics and to the steepness of the dose-response curve, and (2) the intercept, which is linearly related to dose but has no physiologic meaning. The primary goal was to determine the factors affecting the slope by use of univariate and multivariate analyses techniques. Estimates of the slope ranged from 0.67% to 1.1% block/min (interindividual variability, 39%). Factors with clinically significant effects on the slope included the following: age, obesity, and anesthesia type. Thus these factors influence the time course of doxacurium-induced block and may require individualization of dose.

A comparison of pharmacokinetic versus empirical lithium dosing techniques.

Three methods for estimating maintenance dosage requirements of lithium carbonate were retrospectively evaluated in 20 inpatients who met criteria of the Diagnostic and Statistical Manual, Third Edition, for "bipolar disorder, manic phase." Dosing methods evaluated included a pharmacokinetic method, the single-point method of Perry et al.; a population-based nomogram approach, the Zetin et al. method; and a physician-based empirical dosing procedure. The ability of each dosing procedure to produce dosing recommendations that resulted in a targeted steady-state serum lithium concentration was evaluated. The empirical dosing procedure demonstrated a significant tendency (bias) to underestimate the dose necessary to produce a desired steady-state serum lithium concentration. Comparison of the predictive accuracy of the various dosing methods failed to demonstrate any statistically significant differences among the dosing procedures. There was a strong trend, however, for the Perry method to produce predictions of steady-state lithium levels that were more frequently within 0.2 mEq/L of actual levels.

Comparison of pharmacokinetic procedures for dosing lithium based on analysis of prediction error.

Five pharmacokinetic methods for estimating maintenance dosage requirements of lithium carbonate were compared retrospectively in 20 inpatients with acute bipolar illness. Specific pharmacokinetic methods tested included the method of Cooper, the multiple-point method of Perry, the single-point method of Perry, the method of Zetin, and the method of Pepin. Data analysis was based on evaluation of prediction error or the difference between the predicted steady-state lithium concentration and the measured steady-state lithium concentration at equivalent daily doses. Each dosing method was assessed in regard to accuracy and bias of predicted steady-state serum lithium concentrations. Bias was assessed by comparison of the median value of the prediction error with zero. The dosing recommendation based on the Cooper nomogram resulted in a significant positive bias (p less than or equal to 0.05). Intermethod accuracy was assessed by comparison of the absolute prediction errors of each dosing method. Significant differences in accuracy were observed between the method of Pepin when compared with the single-point method of Perry (p less than or equal to 0.05, k-sample sign test). All other comparisons were nonsignificant.

Origin of a gene regulatory mechanism in the evolution of echinoderms.

A rich diversity of ancient sea urchin lineages survives to the present. These include several advanced orders as well as the cidaroids, which represent the group ancestral to all other sea urchins. Here we show that all advanced groups of sea urchins examined possess in their eggs a class of maternal messenger RNA (mRNA) encoded by the evolutionarily highly conserved alpha-subtype histone genes. The maternal histone mRNAs are unique in their time of accumulation in oogenesis, their localization in the egg nucleus and their delayed timing of translation after fertilization. Cidaroid sea urchins as well as other echinoderm classes, such as starfish and sea cucumbers, possess the genes but do not have maternal alpha-subtype histone mRNAs in their eggs. Thus, although all the echinoderms examined transcribe alpha-subtype histone genes during embryogenesis, the expression of these genes as maternal mRNAs is confined to advanced sea urchins. The fossil record allows us to pinpoint the evolution of this mode of expression of alpha-histone genes to the time of the splitting of advanced sea urchin lineages from the ancestral cidaroids in a radiation which occurred in a relatively brief interval of time approximately 190-200 Myr ago. The origin of a unique gene regulatory mechanism can thus be correlated with a set of macroevolutionary events.

Antimalarial amino alcohols II: anthraceneaminoethanols and anthraceneaminopropanols (1- and 9-substituted).

The syntheses of seven anthracene amino alcohols with one, two, or three additional substituents are described. These compounds include three 1-aminoethanols, two 9-aminoethanols, and two 9-aminopropanols, prepared from substituted anthraquinones or from 10-chloro-9-anthraldehydes. The antimalarial activity of these compounds, as well as tentative structure-activity relationships, is discussed in the light of previously published work.