Ethnic disparities in stroke: the scope of the problem

An excess stroke mortality rate among African Americans is well known and should be considered a national crisis. This excess persists today despite dramatic declines in stroke mortality between 1970 and 1990 for both White and African-American men and women. Only a portion of this excess stroke mortality among African Americans can be explained by the higher prevalence of hypertension and diabetes in African Americans, and by the lower average socioeconomic status (SES) among African Americans. The majority of the excess burden of stroke mortality is borne by relatively young (ages 35-64) African Americans and by African Americans living in the Southeastern United States. While overall stroke mortality rates have been rapidly declining for both African Americans and Whites, the magnitude of the relative increased risk of dying from a stroke among African Americans, as compared to Whites, has remained largely unchanged. As such, efforts to reduce ethnic disparities in stroke mortality have been unsuccessful.

Scedosporium prolificans keratouveitis in association with a contact lens retained intraocularly over a long term

Scedosporium prolificans is a soil saprophyte that is associated with a large variety of infectious processes and with respiratory colonization in immunocompetent and immunocompromised patients. We report the first described case of S. prolificans keratouveitis associated with the intraocular long-term retention of a contact lens in a 76-year-old female patient.

Human serum albumin induced hypotension in the postoperative phase of cardiac surgery

Hypotension associated with the rapid infusion of human serum albumin products was first recognised in Australasia in the early 1970s. An association with the angiotensin converting enzyme inhibitor class of drugs (ACE-I) followed, leading to a proposed mechanism involving bradykinin generation through pre-kallikrein activator (PKA) presence in the infused fluid. The newer generation albumin products (Albumex) contain very low concentrations of PKA and are generally thought safe to use in most patient populations. Anecdotal reports of paradoxical hypotension with rapid infusion of 4% albumin in our department led to an audit of practice over three months. Four out of 36 patients (11%) who received 4% albumin intravenously experienced paradoxical hypotension. Three of these patients were taking ACE-I preoperatively (P=0.04). There was no observed hypotension associated with intravenous infusion of crystalloid fluid. We believe 4% albumin should be used with caution, particularly in those patients receiving ACE-I preoperatively.

Method for qualifying microbial removal performance of 0.1 micron rated filters. Part III: bacterial challenge tests on 0.2/0.22 and 0.1 micron rated filter cartridges with Hydrogenophaga (formerly Pseudomonas) pseudoflava

We have previously reported on the preliminary characterization of Hydrogenophaga (formerly Pseudomonas) pseudoflava for potential use as a standard challenge organism to qualify 0.1 microm rated filters. This article reports on the retention efficiencies of a large panel of 0.2/0.22 microm and 0.1 microm rated filter cartridges for H. pseudoflava (ATCC 700892) versus the retention capabilities of the same filters for Brevundimonas diminuta (ATCC 19146). A total of thirty-two 0.2/0.22 microm rated filter cartridges, spanning nine different "sterilizing grade" filter types from four different filter manufacturers, were challenged with H. pseudoflava at challenge levels exceeding 10(7) cfu/cm2. H. pseudoflava was shown to penetrate every 0.2/0.22 microm rated filter tested, with log titer reduction (LTR) values ranging from 3.5 to 7.7 logs. H. pseudoflava was shown to be more penetrative than B. diminuta under the same challenge conditions. B. diminuta was fully retained by nineteen of the twenty 0.2/0.22 microm rated filters that were challenged with both organisms. In the case of 0.1 microm rated filters, eighteen filter cartridges, spanning five different filter types from three manufacturers were tested. H. pseudoflava was consistently retained by four out of the five filter types tested, with LTR values in excess of 11.5 to 12.2 logs. The 0.1 microm rated filter type that was penetrated by H. pseudoflava has been previously demonstrated to be not fully retentive for naturally occurring bacteria. The data show that H. pseudoflava penetrates 0.2/0.22 microm rated filters just as readily as B. diminuta penetrates 0.45 microm rated filters. In addition, titer reductions provided by 0.2/0.22 microm rated filters for H. pseudoflava are comparable to those reported for A. laidlawii mycoplasma, albeit under different conditions. This study demonstrates that H. pseudoflava meets all criteria for use as a standard organism for qualifying the microbial removal performance of 0.1 microm rated filters for enhanced sterility assurance.

Method for qualifying microbial removal performance of 0.1 micron rated filters. Part I: characterization of water isolates for potential use as standard challenge organisms to qualify 0.1 micron rated filters

Although 0.1 microm rated filters intended for pharmaceutical sterilization applications have been commercially available for at least 15 years, there is no industry-wide standard for qualifying the microbial removal performance of these filters. In this article, we report on the bacterial challenge methodology used to screen four bacterial species for potential utility as a standard challenge organism to qualify 0.1 microm rated filters. These isolates were, in their natural state, demonstrated to penetrate 0.2/0.22 microm rated filters in prior studies. In the screening challenges described in this study, three out of these four candidates tested demonstrated consistent penetration of one 0.22 microm rated filter type tested (when cultured in a low nutrient medium under standard laboratory conditions). These included 6204-22 (FAME ID Acidovorax avenae citrulli), 6266-15 (FAME ID Comamonas acidovorans), and 6266-34 (FAME ID Hydrogenophaga pseudoflava). Of these, H. pseudoflava (6266-34) was chosen for additional experiments with other 0.2 microm rated filter membranes. In total, seventeen 0.2 and 0.22 microm rated filter discs, spanning five different "sterilizing grade" filter types from three different filter manufacturers were tested. H. pseudoflava penetration was observed for every filter tested. Under the same challenge conditions, H. pseudoflava was consistently retained by a 0.1 microm rated hydrophilic PVDF (polyvinylidenefluoride) filter with a specified high titer reduction claim for Acholeplasma laidlawii. In order to ensure selection of the most stable penetrative phenotype (i.e., select for nonrevertants), H. pseudoflava was subjected to three rounds of "filter cloning," and these results are described herein. The advantages of using H. pseudoflava for qualifying the microbial removal performance of 0.1 microm rated filters are also discussed.

Method for qualifying microbial removal performance of 0.1 micron rated filters. Part II: preliminary characterization of Hydrogenophaga (formerly Pseudomonas) pseudoflava for use as a standard challenge organism to qualify 0.1 micron rated filters

In this article, we report on the preliminary characterization of Hydrogenophaga (formerly Pseudomonas) pseudoflava for potential use as a standard challenge organism to qualify 0.1 microm rated filters. Filter-cloned H. pseudoflava (ATCC 700892) was easily cultured in a low nutrient broth (R2A broth) under standard laboratory conditions, reaching high titers of 10(8)-10(9) cfu/mL within 48-65 hours of incubation at 25+/-5 degrees C. Under these conditions, H. pseudoflava is a rod-shaped bacterium, averaging 0.25+/-0.03 microm by 1.65+/-0.35 microm, and appears to be smaller than Brevundimonas diminuta in width (0.31+/-0.03 microm), but somewhat longer in length (0.88+/-0.19 microm), which may partly explain the observed penetration. In total, thirty-five 0.2/0.22 microm rated filter discs, spanning five different "sterilizing grade" filter types from two different filter manufacturers were challenged with H. pseudoflava. In all cases, H. pseudoflava was shown to consistently penetrate every 0.2/0.22 microm rated filter disc tested. These tests also spanned three different challenge durations, including short-term challenges (30-40 minutes), and two different challenge fluids. The use of serial (double) 0.22 mm rated filters, which is a common industry practice to reduce the prefiltration bioburden to the final "sterilizing" filter, was also shown to be inadequate to fully retain H. pseudoflava under the challenge condition used. In contrast, two different 0.1 microm rated filter types functionally qualified with a specified high titer reduction claim for Acholeplasma laidlawii, were shown to consistently and fully retain H. pseudoflava, and retention by these two filter types was shown to be robust and independent of the challenge duration.

The effect of endotoxin on hepatocyte nuclear factor 1 nuclear protein binding: potential implications on CYP2E1 expression in the rat

The purpose of this study was to determine if changes in nuclear protein binding of hepatocyte nuclear factor 1 (HNF-1) occur after lipopolysaccharide (LPS) administration. In addition, the time-course of alterations in CYP2E1 regulation were evaluated. Rats were injected with 2.0 mg LPS and euthanized over a 72-h period. Nuclear protein binding to a consensus HNF-1 oligonucleotide was assessed by the electrophoretic mobility shift assay. CYP2E1 activity was analysed using chlorzoxazone as a substrate (60H-CLZ), and CYP2E1 protein concentration was determined by enzyme-linked immunosorbent assay. Endotoxin treatment resulted in decreased nuclear protein binding to an HNF-1 element as early as 1 h after treatment and returned to control levels by 72 h. This reduced binding persisted for 24 h and returned to control values 48 h after LPS administration. In addition, the reduction in binding was primarily attributable to a HNF-1alpha immunoreactive protein. The observed reduction in HNF-1 binding was followed in the time-course by decreases in CYP2E1 activity and protein content with maximal decreases to 50 and 67% of control, respectively, at 48 h after LPS administration. Endotoxin is a potent inducer of the acute phase response (APR). The APR stimulation by endotoxin administration reduced HNF-1alpha binding and decreased the expression of CYP2E1 in the rat liver. The time-course of alterations in HNF-1 and CYP2E1 lend support to the possibility that HNF-1alpha may play a role in the down-regulation of genes that require HNF-1alpha for their constitutive expression. These data serve as an important precedent for future studies evaluating the direct association of decreased HNF-1alpha binding and reduced gene expression after LPS administration.

Decline in US stroke mortality: an analysis of temporal patterns by sex, race, and geographic region

BACKGROUND AND PURPOSE

Although stroke mortality rates have declined rapidly over the past 30 years, the decline has slowed to a plateau. Here, we assess whether the race-sex-region groups have participated equally in this decline and whether there are groups in which stroke mortality rates are still declining, and we predict how these rates will eventually differ.

METHODS

Data on stroke mortality in the United States between 1968 and 1996 were analyzed in a 3-step procedure: (1) we calculated "crude" age-adjusted stroke mortality rates by race, sex, and county; (2) we "smoothed" the rates across counties and years; and (3) we fit a model to describe the temporal pattern. From this model we calculated the percent decline in stroke mortality, the anticipated additional decline (thereby identifying regions that will continue to decline), and the anticipated eventual stroke mortality rates.

RESULTS

Maps by race-sex-region group describe the above parameters. White men have experienced the largest decline in stroke mortality, and black men have seen the smallest. Generally, stroke mortality appears to still be slowly declining for blacks but not for whites. Geographic differences in stroke mortality are predicted to persist.

CONCLUSIONS

The analysis suggests that the Deep South (Alabama and Mississippi) will fall from the stroke belt and be replaced by other regions (notably Oregon, Washington, and Arkansas). New York City and southern Florida had low stroke mortality rates in 1968, have experienced large declines, and continue to experience declines, resulting in even larger relative heterogeneity of stroke mortality rates. The reasons for these differences in the pattern of the decline in stroke mortality are not understood.

Birth cohort evidence of population influences on blood pressure in the United States, 1887-1994

PURPOSE

Mean blood pressure (BP) has declined in the U.S. for several decades. It is unknown to what extent this decline was due to treatment of persons with recognized high BP or to population-wide influences on BP. Treatment would shift only the highest values lower, whereas, population-wide influences on BP would shift the entire distribution downward.

METHODS

We examined changes in the distributions of systolic and diastolic BP (SBP, DBP) across birth cohorts born between 1887 and 1975 in 52,646 individuals examined in the National Health (and Nutrition) Examination Surveys between 1960 and 1994. The BP distributions were estimated as functions of age and birth-year to examine changes between birth cohorts. We postulated that the age-adjusted 10th, 50th and 90th percentiles of SBP and DBP had decreased in more recent versus earlier birth cohorts.

RESULTS

The series of birth cohorts exhibited successively lower SBP and DBP at low, middle and high percentiles. In general, the 10th percentile of SBP decreased approximately 1.19 mmHg per decade of birth-year, whereas the 50th percentile decreased 2.40 mmHg per decade, and the 90th percentile decreased 4.62 mmHg per decade. A similar pattern of results was seen for DBP.

CONCLUSIONS

The entire distribution of both SBP and DBP shifted downward. The downward shifts at the 50th percentile and below unequivocally demonstrate a strong prevention effect in the U.S. population during the period 1887 through 1975. This epidemiologic analysis indicates that population-wide influences can alter favorably the distribution of BP throughout the whole population.

Retention of water-borne bacteria by membrane filters. Part I: Bacterial challenge tests on 0.2 and 0.22 micron rated filters

The results of bacterial challenge tests conducted on several 0.2 and 0.22 micron rated "sterilizing grade" filter cartridge types with bacteria from a natural water source are presented. Eight different 0.2/0.22 micron rated "sterilizing grade" filter types from four different filter manufacturers, claimed to be capable of retaining Brevundimonas diminuta at a challenge level of 10(7) CFU/cm2, were tested. The filters tested included nylon 6.6 and polyamide filters from two manufacturers, modified or hydrophilic PVDF filters from two manufacturers, modified or asymmetric PES filters from three manufacturers, and cellulose acetate filters from a single manufacturer. Consistent bacterial penetration was observed, over the 18-24 h challenge period, for all twenty-five integral 0.2 and 0.22 micron rated filter cartridges tested, at challenge levels of about 10(1)-10(4) CFU/cm2, indicating that natural waterborne bacteria were more penetrative than B. diminuta. The observed penetration was thus qualitatively independent of filter media type or manufacturer. These results add to the growing body of evidence that shows 0.2 and 0.22 micron rated filters may not remove all microorganisms under all conditions. These results further establish that bacterial penetration of 0.2/0.22 micron rated filters is not limited just to (1) specific membrane types, or (2) extended duration challenges (>> 24 h), or (3) extremely high challenge levels, or (4) bacteria that can only exist in a penetrative state in an artificial laboratory setting.

Retention of water-borne bacteria by membrane filters. Part III: Bacterial challenge tests on 0.1 micron rated filters

Clear performance differences were observed between different 0.1 micron rated filters in terms of their microbial removal efficiency when challenged with naturally occurring waterborne bacteria from a water source. Penetration occurred with three 0.1 micron rated "sterilizing grade" filter types tested, from three different filter manufacturers, that did not have a specific high titer reduction claim for Acholeplasma laidlawii. Bacteria shown to penetrate these 0.1 micron rated filters were quite similar to those recovered downstream of 0.2.0.22 micron rated filters (described in Part II). All of the isolates identified via FAME analyses were common environmental or ubiquitous organisms, and some, such as Acidovorax sp. and Hydrogenophaga pseudoflava, have also been isolated from pharmaceutical water systems. In contrast, four different 0.1 micron rated "sterilizing grade" filter types from two different manufacturers, which had been qualified with both B. diminuta and A. laidlawii, consistently produced sterile effluents under similar test conditions. This study thus highlights the need for an industry or regulatory standard method of defining the microbial removal performance of 0.1 micron rated filters, and supports the use of functionally qualified 0.1 micron rated filters as sterilizing grade filters in pharmaceutical operations for enhanced sterility assurance.

Retention of water-borne bacteria by membrane filters. Part II: Scanning electron microscopy (SEM) and fatty acid methyl ester (FAME) characterization of bacterial species recovered downstream of 0.2/0.22 micron rated filters

The results of scanning electron microscopic (SEM) and fatty acid methyl ester (FAME) characterization of the bacterial species shown to penetrate conventional 0.2/0.22 micron rated "sterilizing grade" filters are presented. SEM data suggest that retention of bacteria by these filters appears to be strongly influenced by the morphology, and especially the width of bacteria and less so by length. When the bacterial cell width is small, less than 0.3 micron or so, the cell length does not appear to limit the ability to penetrate 0.2/0.22 micron rated filters. As the bacterial width increases, there is also a strong, almost exponential, decrease in the allowable length for penetration, with most penetrative cells tending to be coccoid beyond a width of 0.5 micron. Significant percentages of the bacteria (40-50%) that were observed downstream of these filters were larger than B. diminuta, the standard organism used to qualify 0.2/0.22 micron rated filters. The average sizes of natural waterborne bacteria that penetrated the filters tested were 20-40% larger in width, and 40-70% larger in length, compared to B. diminuta. These results indicate that size exclusion is not the sole mechanism governing bacterial retention. All isolates identified via FAME analyses were common environmental or ubiquitous organisms, and some, such as Acidovorax sp. and Hydrogenophaga pseudoflava, have also been isolated from pharmaceutical water systems. Most of the bacteria recovered downstream of 0.2/0.22 micron rated filters were gram negative, oxidase positive, motile, nonfermentors.

Cardiovascular risk factors and cognitive decline in middle-aged adults

OBJECTIVE

To perform serial neuropsychological assessments to detect vascular risk factors for cognitive decline in the Atherosclerosis Risk in Communities cohort, a large biracial, multisite, longitudinal investigation of initially middle-aged individuals.

METHODS

The authors administered cognitive assessments to 10,963 individuals (8,729 white individuals and 2,234 black individuals) on two occasions separated by 6 years. Subjects ranged in age at the first assessment from 47 to 70 years. The cognitive assessments included the delayed word recall (DWR) test, a 10-word delayed free recall task in which the learning phase included sentence generation with the study words, the digit symbol subtest (DSS) of the Wechsler Adult Intelligence Scale-Revised and the first-letter word fluency (WF) test using letters F, A, and S.

RESULTS

In multivariate analyses (controlling for demographic factors), the presence of diabetes at baseline was associated with greater decline in scores on both the DSS and WF (p < 0.05), and the presence of hypertension at baseline was associated with greater decline on the DSS alone (p < 0.05). The association of diabetes with cognitive decline persisted when analysis was restricted to the 47- to 57-year-old subgroup. Smoking status, carotid intima-media wall thickness, and hyperlipidemia at baseline were not associated with change in cognitive test scores.

CONCLUSIONS

Hypertension and diabetes mellitus were positively associated with cognitive decline over 6 years in this late middle-aged population. Interventions aimed at hypertension or diabetes that begin before age 60 might lessen the burden of cognitive impairment in later life.

Inflammation and microalbuminuria in nondiabetic and type 2 diabetic subjects: The Insulin Resistance Atherosclerosis Study

BACKGROUND

Microalbuminuria is a risk factor for cardiovascular disease, but the underlying pathomechanisms are still poorly understood. A relationship between C-reactive protein (CRP), a sensitive marker of inflammation, and atherosclerotic disease has been reported recently.

METHODS

We hypothesized that microalbuminuria might be associated with chronic inflammation and investigated the relationship of urinary albumin excretion, as assessed from the albumin-to-creatinine ratio (ACR), in an untimed morning urine specimen, and two inflammatory markers (CRP and fibrinogen) in the large, triethnic population of the Insulin Resistance Atherosclerosis Study (IRAS). After exclusion of subjects with macroalbuminuria, 1481 subjects were studied.

RESULTS

Both inflammatory markers were related to urinary ACR (r = 0.17 for CRP and r = 0.14 for fibrinogen, both P = 0.0001), an association that remained significant after adjustment for demographic variables, diabetic status, smoking, and use of angiotensin-converting enzyme inhibitors (P < 0.01). Mean levels of CRP and fibrinogen were elevated in microalbuminuric (N = 262) versus normoalbuminuric (N = 1219) subjects (5.37 +/- 0.47 vs. 3.80 +/- 0.15 mg/L and 295.7 +/- 4. 0 vs. 278.2 +/- 1.6 mg/dL, both P < 0.0001). The associations were consistent among nondiabetic and type 2 diabetic subjects and among the three ethnic groups of the IRAS (non-Hispanic whites, blacks, Hispanics). In a logistic regression model, fibrinogen was independently associated with microalbuminuria (P = 0.047), along with hypertension, female gender, waist circumference, and fasting blood glucose, while CRP was not independently related to microalbuminuria in this model (P = 0.26).

CONCLUSION

We have shown an association of CRP and fibrinogen with urinary albumin excretion in the microalbuminuric range in type 2 diabetic and nondiabetic individuals. Chronic inflammation therefore emerges as a potential mediator between microalbuminuria and macrovascular disease.

Effect of contralateral occlusion on long-term efficacy of endarterectomy in the asymptomatic carotid atherosclerosis study (ACAS). ACAS Investigators

BACKGROUND AND PURPOSE

The Asymptomatic Carotid Atherosclerosis Study (ACAS) established the effectiveness of prophylactic carotid endarterectomy, for patients in good health who had stenosis >/=60%, if conducted by surgeons with a surgical morbidity and mortality of <3%. This secondary analysis was performed to determine whether the presence of contralateral cervical carotid occlusion alters the efficacy of asymptomatic ipsilateral carotid endarterectomy.

METHODS

One hundred sixty-three participants who had a baseline contralateral occlusion documented by Doppler ultrasound (77 medical, 86 surgical) were compared with 1485 participants with a patent contralateral carotid artery (748 medical, 737 surgical) for the risk of a combined end point of perioperative (30-day) death or stroke or long-term (5-year) ipsilateral stroke.

RESULTS

For those without contralateral occlusion, surgery was associated with a 6.7% absolute reduction in the 5-year risk (95% CI, 2.1% to 11.4%), while for those with a contralateral occlusion, surgery was associated with a 2.0% absolute increase in risk (95% CI, -9.3% to 5.2%), which was a statistically significant difference in the effect of surgery (P:=0.047). This difference is primarily attributable to low long-term risk for medically managed patients with contralateral occlusion.

CONCLUSIONS

While this post hoc analysis should be interpreted with caution, the findings suggest that endarterectomy in asymptomatic subjects with contralateral occlusion provides no long-term benefit (and may be harmful) in preventing stroke and death. These findings were a result of the benign course of medically treated subjects.

Association of educational achievement with pulsatile arterial diameter change of the common carotid artery: the Atherosclerosis Risk in Communities (ARIC) Study, 1987-1992

Education is strongly inversely associated with common carotid artery intima-media thickness in the Atherosclerosis Risk in Communities (ARIC) Study. The authors extended the ARIC study of preclinical atherosclerosis by evaluating the cross-sectional association of education with common carotid artery elasticity. This study included 10,091 Black and White men and women aged 45-64 years who were free of clinical coronary heart disease and stroke/transient ischemic attack. Arterial elasticity was assessed by pulsatile arterial diameter change (PADC), derived from phase-locked echo-tracking. The smaller the PADC, the stiffer the artery. Education was categorized into grade school, high school without graduation, high school with graduation, vocational school, some college, and graduate/professional school. PADC was directly associated with educational attainment. The mean PADCs, adjusted for age, height, diastolic diameter, systolic blood pressure, pulse pressure (linear and squared), ethnicity, gender, and smoking status, in successively higher education strata were 402 (standard error (SE) 5), 403 (SE 4), 407 (SE 3), 413 (SE 4), 416 (SE 2), and 417 (SE 4) microm (p = 0.007). To the authors' knowledge, this is the first time such an association has been reported. If arterial dilation impairment precedes arterial wall thickening in the atherosclerotic process, as recent studies on endothelial dysfunction suggest, these results indicate that low socioeconomic status may be associated with early arterial pathophysiologic changes-an effect that appears to be mediated by established cardiovascular disease risk factors.

A comparison of the extent and impacts of sewage contamination on urban groundwater in developed and developing countries

In much of the world urban groundwater is an important resource for domestic and industrial use. In many developing countries, groundwater taken directly (untreated) from individual springs and wells is the only option available to communities where comprehensive, reliable reticulated supply systems are absent. A common feature of urban groundwater in both developing and developed countries is contamination by sewage. Current and recent research is presented that shows sewer leakage impacts groundwater in developed countries whilst on-site sanitation contaminates groundwater in developing countries. In the latter case, the competing demands of sanitation and groundwater protection must be addressed. Limitations on the usefulness of accepted standard sewage indicator species in groundwater are also highlighted. As sewage contamination of groundwater is usually addressed only if an actual health risk is posed, it is vital both to developed and developing countries to understand the movement of actual pathogens in groundwater in the context of groundwater management. Further research is required on microbial survival and health risks posed by sewage contamination.

Activities of conjugating and antioxidant enzymes following endotoxin exposure

Endotoxin exposure elicits various responses in mammals including the acute phase response that has been shown to cause changes in the activity of several forms of cytochrome P450s and other enzymes. Therefore, the hepatic conjugating enzyme, glutathione S-transferase (GST), and UDP-glucuronosyltransferase (UDPGT), the antioxidant enzymes, glutathione peroxidase (GSHPx), catalase, and superoxide dismutase (SOD), as well as lipid peroxidation were investigated following the administration of endotoxin to male Sprague-Dawley rats (8 mg/kg body weight). Rats were euthanized at various times following endotoxin administration and the livers removed and processed to assess various enzyme activities. Glutathione S-transferase, UDPGT, and GSHPx activity showed statistically significant decreases after 24 hours and remained lower than controls for the duration of the study. Decreases in total SOD and catalase activities were seen at 24, 48, and 72 hours following endotoxin administration; however, only catalase activity showed statistically significant differences between control and treated samples at those time points, and total SOD activity showed a statistically significant decrease at 24 hours. No statistically significant changes were seen in the level of lipid peroxidation in the liver microsomes from endotoxin-treated animals. Changes in the conjugative enzymes and the free-radical scavenging enzymes following endotoxin exposure may alter the host's metabolism and response to free radicals.

Chronic subclinical inflammation as part of the insulin resistance syndrome: the Insulin Resistance Atherosclerosis Study (IRAS)

BACKGROUND

Inflammation has been suggested as a risk factor for the development of atherosclerosis. Recently, some components of the insulin resistance syndrome (IRS) have been related to inflammatory markers. We hypothesized that insulin insensitivity, as directly measured, may be associated with inflammation in nondiabetic subjects.

METHODS AND RESULTS

We studied the relation of C-reactive protein (CRP), fibrinogen, and white cell count to components of IRS in the nondiabetic population of the Insulin Resistance Atherosclerosis Study (IRAS) (n=1008; age, 40 to 69 years; 33% with impaired glucose tolerance), a multicenter, population-based study. None of the subjects had clinical coronary artery disease. Insulin sensitivity (S(I)) was measured by a frequently sampled intravenous glucose tolerance test, and CRP was measured by a highly sensitive competitive immunoassay. All 3 inflammatory markers were correlated with several components of the IRS. Strong associations were found between CRP and measures of body fat (body mass index, waist circumference), S(I), and fasting insulin and proinsulin (all correlation coefficients >0.3, P<0.0001). The associations were consistent among the 3 ethnic groups of the IRAS. There was a linear increase in CRP levels with an increase in the number of metabolic disorders. Body mass index, systolic blood pressure, and S(I) were related to CRP levels in a multivariate linear regression model.

CONCLUSIONS

We suggest that chronic subclinical inflammation is part of IRS. CRP, a predictor of cardiovascular events in previous reports, was independently related to S(I). These findings suggest potential benefits of anti-inflammatory or insulin-sensitizing treatment strategies in healthy individuals with features of IRS.

Trends in severity of hospitalized myocardial infarction: the atherosclerosis risk in communities (ARIC) study, 1987-1994

BACKGROUND

Declining mortality rates of coronary heart disease in the United States could be attributable to declining incidence, declining severity, and/or improvements in treatment.

METHODS

We examined trends in severity of patients hospitalized for myocardial infarction to characterize its contribution to this decline by using data from the Atherosclerosis Risk in Communities (ARIC) study.

RESULTS

No significant change in the proportion having systolic blood pressure <100 mm Hg or an abnormal pulse at presentation was noted. The proportion with ST-segment elevation on the initial electrocardiogram increased 10% per year (P <.001), and the proportion with a diagnostic or evolving diagnostic electrocardiogram abnormality increased 4% per year (P <.01); the proportion that had a new Q-wave infarction develop remained unchanged. The mean peak creatine kinase level decreased 5% per year (P <.001), the proportion with abnormal enzyme levels decreased 10% per year (P <.001), and the proportion that met criteria for definite myocardial infarction decreased 4% per year (P <.05). The proportion that had cardiogenic shock decreased 10.9% per year (P <. 01), but the proportion that had an acute episode of congestive heart failure was stable.

CONCLUSIONS

With stable hemodynamic indicators, worsening electrocardiographic indicators, and improving enzymatic indicators, these results provide mixed support for decreases in the severity of myocardial infarction.