Biomedical subjects

D M Reboussin

Publications and source records attributed to D M Reboussin.

At least 19 recordsLinked to original sources

PubMed2006

Initial screening transferrin saturation values, serum ferritin concentrations, and HFE genotypes in Native Americans and whites in the Hemochromatosis and Iron Overload Screening Study.

We compared initial screening transferrin saturation (TfSat) and serum ferritin (SF) phenotypes and HFE C282Y and H63D genotypes of 645 Native American and 43,453 white Hemochromatosis and Iron Overload Screening Study participants who did not report a previous diagnosis of hemochromatosis or iron overload. Elevated measurements were defined as TfSat >50% in men and >45% in women and SF >300 ng/ml in men and >200 ng/ml in women. Mean TfSat was 31% in Native American men and 32% in white men (p = 0.0337) and 25% in Native American women and 27% in white women (p < 0.0001). Mean SF was 153 microg/l in Native American and 151 microg/l in white men (p = 0.8256); mean SF was 55 microg/l in Native American women and 63 microg/l in white women (p = 0.0015). The C282Y allele frequency was 0.0340 in Native Americans and 0.0683 in whites (p < 0.0001). The H63D allele frequency was 0.1150 in Native Americans and 0.1532 in whites (p = 0.0001). We conclude that the screening TfSat and SF phenotypes of Native Americans are similar to those of whites. The allele frequencies of HFE C282Y and H63D are significantly lower in Native Americans than in whites.

Adult↗

PubMed2004

The combination oral and nutritional treatment of late-onset diabetes mellitus (CONTROL DM) trial results.

OBJECTIVE: To examine the effect of short-term improvements in glycaemic control on brachial artery endothelial function as a marker of cardiovascular health. METHODS: Persons with Type 2 diabetes who were poorly controlled on oral therapy were randomly assigned to monotherapy with repaglinide or combination therapy with repaglinide plus metformin. Brachial artery flow-mediated vasodilation was assessed by ultrasonography at randomization and following 16 weeks of therapy. The primary outcome was change in brachial artery endothelial function from baseline. Comparison of randomized groups was a secondary aim. RESULTS: Eighty-six participants were randomized, and 83 were followed to study completion. Post occlusion brachial artery vasodilation was 3.74% at baseline and 3.82% following 16 weeks of therapy (P = 0.77). The treatment effect was 0.08% (95% CI: -0.48%, 0.64%). No difference was seen between treatment groups (P = 0.69). Overall, A1C was reduced from 8.3% to 7.0%, with a greater reduction in the combination therapy group (from 8.4% to 6.7%) than in the monotherapy group (from 8.3% to 7.3%, p for difference between groups = 0.01). Statistically significant reductions were observed in fasting glucose, and plasminogen activator inhibitor-1. Statistically significant increases were observed for fasting insulin, uric acid, weight and BMI. CONCLUSIONS: Brachial artery endothelial function was not influenced by short-term improvements in glycaemic control. The CONTROL DM group was successful in lowering A1C. Future research should explore more intensive and longer-lasting improvements in glycaemic control on endothelial function. Some data previously published in abstract form (Diabetes 2001; 50 (Suppl. 2): A217).

Administration, Oral↗

PubMed2003

No effect of HRT on health-related quality of life in postmenopausal women with heart disease.

AIM: Previous clinical studies suggest hormone replacement therapy (HRT) alleviates menopausal symptoms and may improve health-related quality of life (HRQL). Most studies on HRT and HRQL were limited in duration (12 months or less) and scope (few and non-standard HRQL measures). The aim of this paper is to assess HRQL in the Estrogen Replacement and Atherosclerosis (ERA) trial. METHODS: A subset of women within a randomized, blinded, placebo-controlled secondary prevention trial has been studied in outpatient and community settings at 5 US sites. A total of 246 postmenopausal women with angiographically documented heart disease (mean age 66 years, 83% Caucasian) were enrolled in the ERA trial. Participants received either 0.625 mg/day conjugated equine estrogen only, estrogen plus 2.5 mg/day medroxyprogesterone acetate, or placebo. HRQL was assessed using validated questionnaire instruments at baseline and follow-up (mean 3.2 years of trial). Physical and mental functioning, life satisfaction, depressive symptoms, urinary incontinence, sleep disturbance, and frequency and intensity of physical symptoms were evaluated. RESULTS: In this group of women with established coronary disease, active therapy was not significantly associated with more favorable outcomes for any HRQL. The estrogen-only group reported more urinary incontinence than the placebo group (p<0.05). Analyses restricted to adherent women (those who took > or = 80% of pills) showed a similar pattern of results, showing that the estrogen only group reported significantly higher urinary incontinence compared to placebo (p<0.01). CONCLUSION: The hormone replacement regimens in the ERA trial did not improve HRQL of postmenopausal women with heart disease.

Adult↗

PubMed2001

Statistical issues in analyzing 24-hour dietary recall and 24-hour urine collection data for sodium and potassium intakes.

Dietary recalls and urine assays provide different metrics for assessing sodium and potassium intakes. Means, variances, and correlations of data obtained from these two modes of measurement differ. Pooling of these data is not straightforward, and results from studies employing the different modes may not be comparable. To explore differences between these metrics, the authors used data from the Trial of Nonpharmacologic Intervention in the Elderly (TONE), which included repeated standardized 24-hour dietary recalls and 24-hour urine collections administered over 3 years of follow-up, to estimate sodium and potassium intakes. The authors examined data from 341 control participants assigned to usual care that were collected between August 1992 and December 1995. Dietary recalls yielded estimates of sodium intake that averaged 22% less than those from urine assays and estimates of potassium intake that averaged 16% greater than those from urine assays. Sodium intake estimates were less repeatable (r = 0.22 for diet; r = 0.30 for urine) than potassium intake estimates (r = 0.49 for diet; r = 0.50 for urine), making relations with outcomes more difficult to characterize. Overall, the performance of the two measurement modes was fairly similar across demographic subgroups. Errors in separate estimations of long term sodium and potassium intakes using short term data were strongly correlated, more strongly than the underlying long term intakes of these electrolytes. Because of the correlated measurement error, estimated regression coefficients for linear models including both electrolytes as predictors may be confounded such that the separate relations between these nutrients and outcomes such as blood pressure cannot be reliably estimated by common analytical strategies.

Aged↗

PubMed2001

Lifestyle interventions influence relative errors in self-reported diet intake of sodium and potassium.

PURPOSE: To characterize the distribution of errors in self-reported sodium and potassium dietary intakes relative to more objective urine measures among participants receiving lifestyle interventions. METHODS: We analyzed longitudinal data from 900 individuals with hypertension who had been enrolled in a randomized controlled clinical trial to establish whether usual care or three lifestyle interventions (weight loss, sodium reduction, and combined weight loss and sodium reduction) could effectively substitute for phamacotherapy. Repeated standardized 24-hour diet recalls and 24-hour urine collections were collected over up to three years of follow-up to estimate sodium and potassium intakes. By contrasting self-reported and urine-based sodium and potassium data collected before and during interventions, we examined the relative impact of intervention assignment on estimated intakes, repeatability, and multivariate measurement error. RESULTS: Relative to urine-based measures, mean self-reported sodium intakes were biased about 10% lower among participants assigned to combined weight loss and sodium reduction, but were unaffected by the other interventions. The repeatability of self-report measures increased slightly with time, particularly among participants assigned to sodium interventions. Errors in self-reported sodium and potassium intakes were correlated before the start of the intervention, but became uncorrelated among individuals assigned to sodium restriction interventions. CONCLUSIONS: Lifestyle interventions may influence not only diet intake, but also the measurement of diet intake.

Aged↗

PubMed2001

Cognitive risk factors and suicide attempts among formerly hospitalized adolescents: a prospective naturalistic study.

OBJECTIVE: To examine the relationship between cognitive variables and time until suicide attempts among 180 adolescents who were monitored for as much as 6.9 years after discharge from an inpatient psychiatry unit. METHOD: In a prospective naturalistic study, adolescents were assessed at the time of their psychiatric hospitalization and semiannually thereafter. Suicidal behavior at index hospitalization and over the follow-up period was assessed with semistructured psychiatric diagnostic interviews. At hospitalization, cognitive risk factors were assessed with a problem-solving task and with questionnaires assessing hopelessness, expectations for posthospitalization suicidal behavior, reasons for living, and dysfunctional attitudes. RESULTS: Expectations about future suicidal behavior were related to posthospitalization suicide attempts. Among youths with previous suicide attempts, higher levels of hopelessness were associated with increased risk, and greater survival and coping beliefs were associated with decreased risk for posthospitalization suicide attempts. Hopelessness and survival and coping beliefs were not related to posthospitalization attempts among adolescents without prior suicidal behavior, and hopelessness was not predictive after controlling for overall severity of depression. CONCLUSIONS: Expectations for suicidal behavior, hopelessness, and survival and coping beliefs provide important prognostic information about later suicidal behavior and should be targeted in interventions with suicidal youths.

Adolescent↗

PubMed2000

Effects of estrogen replacement on the progression of coronary-artery atherosclerosis.

BACKGROUND: Heart disease is a major cause of illness and death in women. To understand better the role of estrogen in the treatment and prevention of heart disease, more information is needed about its effects on coronary atherosclerosis and the extent to which concomitant progestin therapy may modify these effects. METHODS: We randomly assigned a total of 309 women with angiographically verified coronary disease to receive 0.625 mg of conjugated estrogen per day, 0.625 mg of conjugated estrogen plus 2.5 mg of medroxyprogesterone acetate per day, or placebo. The women were followed for a mean (+/-SD) of 3.2+/-0.6 years. Base-line and follow-up coronary angiograms were analyzed by quantitative coronary angiography. RESULTS: Estrogen and estrogen plus medroxyprogesterone acetate produced significant reductions in low-density lipoprotein cholesterol levels (9.4 percent and 16.5 percent, respectively) and significant increases in high-density lipoprotein cholesterol levels (18.8 percent and 14.2 percent, respectively); however, neither treatment altered the progression of coronary atherosclerosis. After adjustment for measurements at base line, the mean (+/-SE) minimal coronary-artery diameters at follow-up were 1.87+/-0.02 mm, 1.84+/-0.02 mm, and 1.87+/-0.02 mm in women assigned to estrogen, estrogen plus medroxyprogesterone acetate, and placebo, respectively. The differences between the values for the two active-treatment groups and the value for the placebo group were not significant. Analyses of several secondary angiographic outcomes and subgroups of women produced similar results. The rates of clinical cardiovascular events were also similar among the treatment groups. CONCLUSIONS: Neither estrogen alone nor estrogen plus medroxyprogesterone acetate affected the progression of coronary atherosclerosis in women with established disease. These results suggest that such women should not use estrogen replacement with an expectation of cardiovascular benefit.

Adult↗

PubMed2000

Titrated moderately suprathreshold vs fixed high-dose right unilateral electroconvulsive therapy: acute antidepressant and cognitive effects.

BACKGROUND: The antidepressant and cognitive side effects of right unilateral (RUL) electroconvulsive therapy (ECT) are reported to depend on the magnitude of the electrical stimulus relative to the seizure threshold. The stimulus doses explored in previous clinical trials of RUL ECT have generally been limited to 1 to 2.5 times the convulsive threshold and the antidepressant efficacy has been low compared with bilateral (BL) ECT. The present study compares the antidepressant and cognitive side effects of 2 RUL dosing strategies: titrated moderately suprathreshold and fixed high dose. METHODS: Seventy-two adult patients with major depression were randomized to either titrated RUL ECT at 2.25 times initial seizure threshold (mean dose, 136 millicoulombes [mC]), or RUL ECT at a fixed dose of 403 mC. Primary outcome measures were antidepressant response and cognitive status 1 or 2 days after the course of ECT. RESULTS: The 2 treatment groups were comparable in demographic and clinical characteristics prior to ECT. Both groups received a mean of 5.7 sessions of RUL ECT. Patients receiving fixed-dose ECT were more likely to have an antidepressant response at the end of the protocol (n = 49 [67%]) compared with those receiving titrated dosing (n = 28 [39%]). Furthermore, the likelihood of both antidepressant response and cognitive deficits increased as stimulus dose increased relative to initial seizure threshold, up through 8 to 12 times the threshold. CONCLUSIONS: The antidepressant efficacy and cognitive side effects of RUL ECT are dependent on the magnitude of the stimulus dose relative to the seizure threshold, and a dose-response relationship extends through at least 12 times the seizure threshold.

Adult↗

PubMed2000

The estrogen replacement and atherosclerosis (ERA) study: study design and baseline characteristics of the cohort.

The Estrogen Replacement and Atherosclerosis (ERA) trial is a three-arm, randomized, placebo-controlled, double-blind trial to evaluate the effects of estrogen replacement therapy (0.625 mg/day oral conjugated estrogen) with or without continuous low-dose progestin (2.5 mg oral medroxyprogesterone acetate/day) versus placebo on progression of atherosclerosis. A total of 309 postmenopausal women at five sites underwent baseline coronary angiography and were randomized. Participants will have repeat coronary angiography after an average of 3.25 years of treatment. The primary outcome of interest will be change in minimum diameter of the major epicardial segments, as assessed by quantitative coronary angiography. The primary aim is to test the hypothesis that either form of hormone therapy will slow the progression or induce regression of coronary atherosclerosis compared to placebo. The secondary aims are to assess the effects of the two treatments versus placebo on endothelial function (measured using flow-mediated vasodilator responses), on several presumed mediators of estrogen's effect on atherosclerosis (i.e., plasma lipids and lipoproteins, blood pressure, glucose metabolism, hemostatic factors, and antioxidant activity), on other factors that influence the development of coronary heart disease (i.e., diet, smoking status, exercise, weight, and health-related quality of life issues), and on clinical cardiovascular events. The ERA trial is the first angiographic endpoint clinical trial to examine the effects of postmenopausal hormone replacement on coronary atherosclerosis in women. It will provide an unparalleled opportunity to determine if either regimen of hormone therapy is effective in slowing the progress of angiographically defined coronary atherosclerosis. This study will complement other estrogen replacement trials, such as the PEPI, HERS, and Women's Health Initiative studies, to provide a more comprehensive examination of the effects of estrogen replacement on cardiovascular risk factors, anatomic and functional manifestations of atherosclerosis, and risk for coronary heart disease in postmenopausal women. Control Clin Trials 2000;21:257-285

Aged↗

PubMed2000

Computations for group sequential boundaries using the Lan-DeMets spending function method.

We describe an interactive Fortran program which performs computations related to the design and analysis of group sequential clinical trials using Lan-DeMets spending functions. Many clinical trials include interim analyses of accumulating data and rely on group sequential methods to avoid consequent inflation of the type I error rate. The computations are appropriate for interim test statistics whose distribution or limiting distribution is multivariate normal with independent increments. Recent theoretical results indicate that virtually any design likely to be used in a clinical trial will fall into this category. Interim analyses need not be equally spaced, and their number need not be specified in advance. In addition to determining sequential boundaries using an alpha spending function, the program can perform power computations, compute probabilities associated with a given set of boundaries, and generate confidence intervals.

Clinical Trials as Topic↗

PubMed1999

Psoriasis causes as much disability as other major medical diseases.

BACKGROUND: Little is known about how the health-related quality of life (HRQL) associated with psoriasis compares with that of other patient populations. OBJECTIVE: We describe HRQL associated with psoriasis and compare it with HRQL of patients with other major chronic health conditions. A second aim is to identify which specific aspects of psoriasis contribute most to HRQL. METHODS: A total of 317 patients completed a non-disease-specific measure of HRQL. Responses were compared with those of patients with 10 other chronic health conditions. HRQL was regressed on ratings of 18 aspects of psoriasis. RESULTS: Patients with psoriasis reported reduction in physical functioning and mental functioning comparable to that seen in cancer, arthritis, hypertension, heart disease, diabetes, and depression. Six aspects of psoriasis predicted physical functioning, and 5 different disease aspects predicted mental functioning. CONCLUSION: The impact of psoriasis on HRQL is similar to that of other major medical diseases. Different aspects of psoriasis are related to the different dimensions of HRQL supporting the need for multidimensional treatment models.

Adult↗

PubMed1999

Suicide attempts among formerly hospitalized adolescents: a prospective naturalistic study of risk during the first 5 years after discharge.

OBJECTIVE: To examine risk for suicide attempts among 180 consecutively referred adolescents during the first 5 years after discharge from an inpatient psychiatry unit. METHOD: In a prospective naturalistic study, adolescents were assessed at psychiatric hospitalization and semiannually thereafter for up to 5 years with semistructured psychiatric diagnostic interviews and self-report questionnaires. RESULTS: Approximately 25% of the adolescents attempted suicide and no adolescents completed suicide within the first 5 years after discharge. The first 6 months to 1 year after discharge represented the period of highest risk. The number of prior attempts was the strongest predictor of posthospitalization attempts. Affective disorders by themselves did not predict later suicide attempts but were related to posthospitalization attempts when accompanied by a history of past suicide attempts. Independent of psychiatric diagnoses, severity of depressive symptoms and trait anxiety also predicted suicide attempts. Similar to the effect with affective disorders, depressive symptoms were most strongly related to posthospitalization suicidality among adolescents with a prior history of suicide attempts. CONCLUSIONS: Particularly among youths with prior suicidal behavior, clinicians should be alert to the above constellation of psychiatric predictors of posthospitalization suicidal behavior.

Adolescent↗

PubMed1999

Estimating equations for a latent transition model with multiple discrete indicators.

This paper proposes a two-part model for studying transitions between health states over time when multiple, discrete health indicators are available. The includes a measurement model positing underlying latent health states and a transition model between latent health states over time. Full maximum likelihood estimation procedures are computationally complex in this latent variable framework, making only a limited class of models feasible and estimation of standard errors problematic. For this reason, an estimating equations analogue of the pseudo-likelihood method for the parameters of interest, namely the transition model parameters, is considered. The finite sample properties of the proposed procedure are investigated through a simulation study and the importance of choosing strong indicators of the latent variable is demonstrated. The applicability of the methodology is illustrated with health survey data measuring disability in the elderly from the Longitudinal Study of Aging.

Aged↗

PubMed1999

A comparison of fast spin-echo, fluid-attenuated inversion-recovery, and diffusion-weighted MR imaging in the first 10 days after cerebral infarction.

BACKGROUND AND PURPOSE: Echo-planar diffusion-weighted and fluid-attenuated inversion-recovery (FLAIR) imaging have both proved valuable for detecting acute ischemic infarcts, but little is known about the value of diffusion-weighted imaging beyond the acute infarct period. Furthermore, no direct comparison of the techniques has been published. We compared the diagnostic utility of diffusion-weighted, FLAIR, and T2-weighted fast spin-echo (FSE) imaging for detecting cerebral infarctions up to 10 days old. METHODS: FSE, FLAIR, and diffusion-weighted MR sequences were obtained prospectively over a 6-month period in 212 patients with suspected cerebral infarctions. Seventy patients with nonhemorrhagic ischemic infarcts less than 10 days old whose symptoms lasted longer than 48 hours were identified. The three sequences were compared for detectability and conspicuity of abnormalities that correlated with the neurologic deficit. RESULTS: Seventy-two symptomatic infarcts were found in the 70 patients. Diffusion-weighted imaging detected 70 (97%), FLAIR, 69 (96%), and FSE, 64 (89%) of the 72 lesions. Only the difference between diffusion-weighted and FSE imaging approached statistical significance. There was no difference in the number of lesions detected in the patients imaged 48 hours or more after infarction. Lesion conspicuity on diffusion-weighted images was judged superior to that on FSE and FLAIR images in 55 (77%) and 47 (67%) of the cases, respectively. FLAIR images were judged superior to FSE in 34 (48%) of the cases. CONCLUSION: Diffusion-weighted images showed more infarcts than FLAIR and FSE images, and FLAIR images showed more than FSE images, but the differences were not statistically significant. Lesion conspicuity, however, was consistently better on diffusion-weighted images than on either FLAIR or FSE images throughout the 10-day period. Acquisition of diffusion-weighted images in the late acute and subacute periods after ischemic cerebral infarction appears to be beneficial.

Acute Disease↗

PubMed1998

Variation of ictal electroencephalographic regularity with low-, moderate-, and high-dose stimuli during right unilateral electroconvulsive therapy.

BACKGROUND: Previous work has demonstrated changes in electroencephalographic (EEG) ictal morphology during electroconvulsive therapy (ECT) as stimulus intensity is increased from barely suprathreshold to moderately suprathreshold. Our study reports on the reactivity of seizure regularity ratings in 11 subjects receiving right unilateral (RUL) ECT as the stimulus is varied over a wider range of intensities from low to medium, then high dose. METHODS: The stimulus intensity of all 11 subjects was first increased from barely suprathreshold to moderately suprathreshold, and then randomized to either stay at a moderately suprathreshold dose or increase to a high dose. The regularity of the EEG ictal discharge was visually measured on a seven-point scale. RESULTS: We found that seizure regularity increases as the stimulus intensity moves from the barely suprathreshold to the moderately suprathreshold dosage, but did not increase further when the stimulus increased to a high dose. CONCLUSIONS: These results suggest that EEG regularity is unlikely to distinguish moderately suprathreshold from markedly suprathreshold stimuli during RUL ECT.

Aged↗

PubMed1998

Cardiotomy suction: a major source of brain lipid emboli during cardiopulmonary bypass.

BACKGROUND: Brain injury remains a significant problem in patients undergoing cardiac surgery assisted by cardiopulmonary bypass (CPB). Autopsy brain specimens of patients after cardiac operations with CPB reveal numerous acellular lipid deposits (10 to 70 microm) in the microvasculature. We hypothesize that these small capillary and arterial dilatations result from a diffuse inflammatory response to CPB or from emboli delivered by the bypass circuit. This study was undertaken to determine which aspect of CPB is most clearly associated with these dilatations. METHODS: Thirteen dogs were studied in four groups: group I (n = 3), right-heart CPB; group II (n = 2), lower-extremity CPB; group III (n = 3), hypothermic CPB; and group IV (n = 5), hypothermic CPB with cardiotomy suction. All dogs in all groups were maintained on CPB for 60 minutes and then euthanized. Brain specimens were harvested, fixed in ethanol, embedded in celloidin, and stained with the alkaline phosphate histochemical technique so that dilatations could be counted. RESULTS: All dogs completed the protocol. The mean density of dilatations per square centimeter for each group was as follows: group I, 1.77 +/- 0.77; group II, 4.17 +/- 1.65; group III, 4.54 +/- 1.69; and group IV, 46.5 +/- 14.5. In group IV (cardiotomy suction), dilatation density was significantly higher than in group III (hypothermic cardiopulmonary bypass) (p = 0.04) and all other groups (p = 0.04). CONCLUSIONS: Blood aspirated from the surgical field and subsequently reinfused into dogs undergoing CPB produces a greater density of small capillary and arterial dilatations than CPB without cardiotomy suction, presumably because of lipid microembolization.

Alkaline Phosphatase↗

PubMed1998

Psychiatric diagnoses of previous suicide attempters, first-time attempters, and repeat attempters on an adolescent inpatient psychiatry unit.

OBJECTIVE: To compare psychiatric diagnoses of hospitalized adolescents who (a) have made previous but no recent suicide attempts, (b) have recently made their first suicide attempt, (c) have recently made a second or subsequent attempt, or (d) have never made an attempt. METHOD: Semistructured psychiatric diagnostic interviews were used to determine psychiatric diagnoses and history of recent and previous suicidal behavior of 269 consecutively admitted adolescents to an inpatient psychiatric facility. Forty-nine previously suicidal youths, 28 first-time attempters, and 33 repeat attempters were compared with 159 nonsuicidal youths in prevalence of Axis I psychiatric disorders and psychiatric comorbidity with affective disorder. RESULTS: Previous attempters and repeat attempters both reported more affective disorders, whereas first-time attempters reported more adjustment disorders than nonsuicidal youths. Previous attempters and nonsuicidal youths reported the most externalizing disorders. CONCLUSIONS: Previous attempters on an inpatient unit have multiple psychiatric problems. Like repeat attempters, they often are depressed, but like nonsuicidal youths, they also exhibit significant externalizing behaviors. Interventions with these adolescents should focus not only on immediate presenting problems, but also on ameliorating their long-term risk of posthospitalization suicidal behavior.

Adolescent↗

PubMed1998

Laser microprobe mass spectrometric study of aluminum and silicon in brain emboli related to cardiac surgery.

Recent investigations have shown numerous fatty microemboli, which we previously termed small capillary and arteriolar dilatations (SCADs), in brain microvessels of patients who died after cardiac surgery assisted by cardiopulmonary bypass (CPB). The hypothesis of this study was that extraneous trace elements such as aluminum (Al) and silicon (Si) might be contaminating the blood and causing the formation of SCADs or coating the SCADs already formed in the extracorporeal circulation during CPB. Small capillary and arteriolar dilatations were identified in thick celloidin sections of the brains of 8 patients who died after cardiac surgery supported with a membrane oxygenator, and of 2 dogs that underwent CPB with a bubble oxygenator. The sections were infiltrated with Spurr's embedding medium for electron microscopy. Resin sections 0.5 microm thick were placed on 100-mesh copper grids and analyzed with laser microprobe mass spectrometry. Brain sections without SCADs from 3 patients (controls) whose deaths were not related to cardiac surgery were processed similarly. In SCADs and nearby neuropil sites of the 8 patients who had cardiac surgery, both Al and Si values were higher than in the neuropil, including vessels of the 3 controls. Si values were also high in the 2 dogs, in which a bubble oxygenator was used. Our results indicate that contamination with Al and Si continues to occur during cardiac surgery assisted by CPB. Our data also suggest that switching to membrane oxygenators from bubble oxygenators for CPB may have reduced Si contamination of blood. Further refinements of CPB aimed at eliminating microemboli formation and Al and Si entry into the circulation are warranted.

Adult↗