Spinal cord pilocytic astrocytoma with leptomeningeal dissemination to the brain. Case report and review of the literature

Leptomeningeal dissemination of low-grade spinal cord gliomas is an uncommon event. The authors report a unique case of leptomeningeal dissemination of a spinal cord pilocytic astrocytoma (PCA) to the intracranial cerebral subarachnoid spaces in a child. A 2-year-old boy presented with a loss of balance and the inability to walk or stand. An intradural intramedullary spinal cord tumor was identified, and the lesion was subtotally resected and diagnosed by the pathology department to be a PCA. Subsequently, the patient had recurrences of the intradural intramedullary tumor at 6 months and 2 years after his original presentation. He underwent a repeated resection of the recurrent tumor and fenestration of an associated syrinx on both occasions. The pathological characteristics of the reresected tumor remained consistent with those of a PCA. Postoperative imaging after his last surgery revealed diffuse intracranial leptomeningeal dissemination into the cisternal space surrounding the midbrain, the suprasellar region, and the internal auditory canal, as well as nodular subarachnoid disease in the upper cervical region. The patient then underwent chemotherapy, and total spine magnetic resonance (MR) imaging 2 months later demonstrated stability in the size of the spinal cord tumor and a decrease in the associated syrinx. However, an MR image of the head demonstrated two new areas of supratentorial subarachnoid leptomeningeal spread of the primary spinal cord tumor at the 2-month follow-up examination. At the 6-month follow-up examination, MR imaging of the head and spine demonstrated stable metastatic disease. This case illustrates a unique instance of supratentorial leptomeningeal dissemination of an intramedullary spinal cord PCA in a child.

PEDIATRIC INTRADURAL EXTRAMEDULLARY SYNOVIAL SARCOMA

OBJECTIVE

The diagnosis of intradural synovial sarcoma has not been previously published. This report provides a summary of the literature on this tumor and on tumors arising in this location, as well as a description of this patient's clinical course.

CLINICAL PRESENTATION

An 11-year-old girl presented with back pain and radiculopathy. A magnetic resonance imaging scan of the spine revealed a spinal intradural, extramedullary mass at L2–L4 and four additional nodules of enhancement.

INTERVENTION

The mass was nearly totally resected. Radiation and chemotherapy were administered. Intracranial metastases became evident during treatment. The patient died of the disease 14 months after diagnosis.

CONCLUSION

The rapid progression of leptomeningeal metastasis despite maximal treatment demonstrates the aggressive nature of the tumor and the need for further study.

Teaching Pediatric Laboratory Medicine to Pathology Residents

Context.—Laboratory data are essential to the medical care of fetuses, infants, children, and adolescents. However, the performance and interpretation of laboratory tests on specimens from these patients, which may constitute a significant component of the workload in general hospitals and integrated health care systems as well as specialized perinatal or pediatric centers, present unique challenges to the clinical pathologist and the laboratory. Therefore, pathology residents should receive training in pediatric laboratory medicine.

Objective.—Children's Health Improvement through Laboratory Diagnostics, a group of pathologists and laboratory scientists with interest and expertise in pediatric laboratory medicine, convened a task force to develop a list of curriculum topics, key resources, and training experiences in pediatric laboratory medicine for trainees in anatomic and clinical pathology or straight clinical pathology residency programs and in pediatric pathology fellowship programs.

Data Sources.—Based on the experiences of 11 training programs, we have compiled a comprehensive list of pediatric topics in the areas of clinical chemistry, endocrinology, hematology, urinalysis, coagulation medicine, transfusion medicine, immunology, microbiology and virology, biochemical genetics, cytogenetics and molecular diagnostics, point of care testing, and laboratory management. This report also includes recommendations for training experiences and a list of key texts and other resources in pediatric laboratory medicine.

Conclusions.—Clinical pathologists should be trained to meet the laboratory medicine needs of pediatric patients and to assist the clinicians caring for these patients with the selection and interpretation of laboratory studies. This review helps program directors tailor their curricula to more effectively provide this training.

Multinutrient supplement containing ephedra and caffeine causes weight loss and improves metabolic risk factors in obese women: a randomized controlled trial

OBJECTIVE

To determine the safety and efficacy of a dietary supplement with a low dose of ephedra and caffeine in overweight/obese premenopausal female subjects.

DESIGN

A 9-month, double-blind, randomized control study compared the efficacy and safety of a dietary supplement with ephedra and caffeine to a control supplement.

SUBJECTS

Sixty-one healthy, premenopausal women with body mass index (BMI) from 27 to 39 kg/m2 were randomly assigned and received a dietary supplement (40 mg/day ephedra alkaloids, 100 mg/day caffeine, high potency mixture of vitamins, minerals, omega-3 fatty acids) or a control supplement for 9 months.

MEASUREMENTS

EFFICACY

changes in body weight, body composition, lipids, insulin, leptin, adiponectin, ghrelin, and self-reports of physical activity, diet and quality of life indices.

SAFETY

blood pressure, heart rate, electrocardiograms, urinalysis, blood histology, serum chemistry measures and self-reported symptoms.

RESULTS

Forty-one women completed the study. The treatment group lost significantly more body weight (-7.18 kg) and body fat (-5.33 kg) than the control group (-2.25 and -0.99 kg, respectively), and showed significant declines in heart rate, serum cholesterol, triglycerides, cholesterol to high-density lipoprotein ratio, glucose, fasting insulin, and leptin. Blood pressure, electrocardiograms, other clinical chemistry measures, blood histology, urinalysis, and self-reported physical activity were similar in the groups. Minor symptoms included dry mouth, insomnia, nervousness and palpitations. The treatment group reported more energy and decreased appetite compared to controls and scored higher on a quality of life domain assessing vitality.

CONCLUSION

A dietary supplement containing a low potency ephedra/caffeine mixture appeared safe and effective in causing loss of weight and body fat, and improving several metabolic parameters, including insulin sensitivity and lipid profiles when tested under physician supervision. Such supplements could be a useful tool to assist with weight loss.

Infantile Crohn disease presenting with diarrhea and pyoderma gangrenosum

Cutaneous erosions and ulcerations in the diaper area are common in infancy and usually result from local irritation. We describe an infant with chronic diarrhea and failure to thrive who developed extensive ulcerations in the inguinal folds and perineum that were initially thought to be exclusively caused by local irritation. A cutaneous examination found signs consistent with those of pyoderma gangrenosum, leading to a diagnosis of infantile Crohn disease. Cutaneous signs can lead to the diagnosis of an underlying systemic disease in infants with chronic diarrhea and rash. Prompt diagnosis is especially important in infantile Crohn disease, since many infants require surgical resection of affected bowel, and 60% die from disease complications. This article reports a rare instance of an infant who developed pyoderma gangrenosum due to Crohn disease and reviews cutaneous signs of systemic disease in infants presenting with chronic diarrhea and rash.

Association of cloacal anomalies, caudal duplication, and twinning

Cloacal anomalies exhibit a wide variety of morphologic types and accompanying clinical severity. The association of malformations of the cloaca with partial, complete, or conjoined twinning has been appreciated for some time, but, with the advent of prenatal ultrasound technology, appears to occur with a greater frequency than once thought. This observation has important implications for pathogenesis. We present 2 representative cases, a 19-week-old female fetus with duplication of several caudal structures and a 21-week-old male fetus with cloacal exstrophy variant and demised co-twin with lower abdominal wall defect, extruded intestinal tract, absent external genitalia, and imperforate anus. These findings and previously published theories suggest that certain models of monozygotic twinning may apply to the pathogenesis of cloacal anomalies. Specifically, the partial or complete duplication of the organizing center within a single embryonic disc may increase the risk of mesodermal insufficiency and thus account for the failure of complete development of the cloacal membrane and consequent exstrophy or other aberration.

Heightened susceptibility to chronic gastritis, hyperplasia and metaplasia in Kcnq1 mutant mice

Increased susceptibility to gastric cancer has been associated with a wide range of host genetic and environmental factors, including Helicobacter pylori infection. Helicobacter pylori infection is postulated to initiate a progression through atrophic gastritis, metaplasia and dysplasia to cancer, and has been associated with reduction of acid output and dysregulation of stomach mucins. Here, we present the characterization of two mouse lines carrying mutant alleles of the gene encoding the Kcnq1 potassium channel, which very rapidly establish chronic gastritis in a pathogen-exposed environment. These mice develop gastric hyperplasia, hypochlorhydria and mucin dysregulation independent of infection. Metaplasia, dysplasia and pre-malignant adenomatous hyperplasia of the stomach have been observed in these Kcnq1 mutant mice, also independent of infection. The data presented here suggest that Kcnq1 mutant mice can be used both as an efficient model for the development of atrophic gastritis after infection and to determine the processes during the later stages of progression to gastric cancer independent of infection. Thus, Kcnq1 mutant mice are a powerful new tool for investigating the connection between acid balance, Helicobacter infection and mucin disruption in the progression to gastric cancer.

Flow Cytometric Validation of Automated Differentials in Pediatric Patients

Manual differential white blood cell (WBC) counting has been considered the gold standard and is routinely used to validate differentials obtained with other methodologies. To validate the accuracy of automated lymphocyte counts, we compared 2-part differentials using a Coulter HmX hematology analyzer and a Coulter XL flow cytometer to analyze 57 pediatric samples with WBC counts ranging from 0.7 k to 33.4 k. These data were compared with manual differential counts. We found excellent correlation between the two automated lymphocyte and monocyte counting methods that surpassed the manual correlations, indicating manual lymphocyte or monocyte counts are unnecessary in the setting of quality scatterplots. To evaluate the use of automated differentials for our most labor-intensive cases (low WBCs, which frequently require manual differentials) we then compared 3-part differentials using the HmX hematology analyzer and flow cytometer for 51 samples with total WBC < or = 1.1 x 10(9)/L. Manual differentials (< or = 100-cell counts) were available on 27 samples. Although the correlations for manual versus automated or flow differentials were good for all cell types, the correlation between the two automated methods was better, irrespective of the hematology analyzer scatterplot quality. Preliminary data provide additional evidence that automated differentials in samples with WBC of < or = 1.1 x 10(9)/L are acceptable for reporting, thus saving technologist time and improving patient care by decreasing the resulting turnaround time. These studies suggest that comparison with a standardized procedure like flow cytometry would be a better method for validation of automated differentials than comparison with the less precise, more laborious manual differential.

Evaluation of early marrow response in childhood aneuploid acute lymphoblastic leukemia: flow cytometric DNA analysis versus standard morphology

Despite improved survival rates for childhood acute lymphoblastic leukemia (ALL), the relapse rate remains at 20-30%. Early peripheral blood and bone marrow (BM) responses have been associated with more favorable outcomes; all current children's cancer group (CCG) protocols for ALL require BM evaluation at days 7 and 14 with subsequent therapy based on the results. Morphologic interpretation of aspirate smears during induction chemotherapy is challenging, as the samples are often hypocellular, excessively friable, and cytologically altered by drugs. We have shown discordancy of day 7 and 14 BM lymphoblast counts using morphologic and flow cytometric immunophenotypic analyses (FC). The aim of our study was to determine the utility, reliability, and cost effectiveness of lymphoblast enumeration using DNA content analysis by flow cytometry (DNA-FC) and to further demonstrate the subjectivity of morphologic review. All new cases of ALL had DNA-FC and FC analyses. The percentage of lymphoblasts as determined by both methods was compared for 82 aneuploid cases. Three pathologists independently reviewed aspirate smears from 39 bone marrow samples of aneuploid ALL that were obtained during early induction. These results were compared among themselves and with the results obtained by DNA-FC. We found excellent correlation between the percentage of lymphoblasts as determined by DNA-FC and FC (R2 = 0.97) over a range of 0 to 99%. Pathologic review agreed with the DNA-FC, on average, 68%. The sensitivity, specificity, and positive and negative predictive values of morphologic review, averaged 53, 84, 78, and 63%, respectively, when using DNA-FC as the "gold standard." All three pathologists achieved agreement of lymphoblast percentage by morphology in 72%. In our laboratory, the use of DNA-FC equates to one-sixth the time and one-half the price of FC per exam. We have shown a strong correlation between blast counts determined by DNA-FC and FC. DNA-FC is an objective, economical, and reliable method to assess early response in induction marrows from aneuploid ALL where morphology is often uninterpretable. This test is highly reproducible and available at most pediatric institutions. Prospective studies need to be employed to evaluate the effect of more definitive methods (DNA-FC and FC) of assessing the early response in bone marrows on prognosis.

Myocardial-tissue-specific phenotype of maternal microchimerism in neonatal lupus congenital heart block

BACKGROUND

During pregnancy, maternal cells pass into the fetus, where they can persist for many years after birth. We investigated the presence of maternal cells in neonatal lupus syndrome (NLS), an autoimmune disease that develops in utero. The most serious complication of NLS is inflammation of the atrioventricular node leading to congenital heart block (CHB).

METHODS

In a blinded case-control study, maternal (female) cells were detected and quantified in male NLS and control heart-tissue samples. We used fluorescence in-situ hybridisation to label X and Y chromosomes. Studies in transplantation suggest that donor cells can differentiate into somatic tissue cells. Therefore, we asked whether maternal cells transferred in utero have cellular plasticity. To simultaneously identify and characterise maternal cells, we developed a technique by which multiple phenotypic markers could be detected concurrently with fluorescence in-situ hybridisation in the same cells of a tissue section.

FINDINGS

Maternal cells were found in 15 of 15 sections of NLS heart tissue, ranging from 0.025% to 2.2% of total cells. By contrast, maternal cells were found in two of eight control sections (0-0.1%). Very few maternal cells expressed the haemopoietic cell marker CD45. Most expressed sarcomeric alpha actin, a specific marker for cardiac myocytes.

INTERPRETATION

Our findings suggest that differentiated tissue-specific maternal microchimerism can occur in neonates. Thus, semiallogeneic maternal cells could be the target of an immune response. Alternatively, maternal cells could contribute to a secondary process of tissue repair.

Exponential processes in human auditory excitation and adaptation

Peripheral auditory adaptation has been studied extensively in animal models, and multiple exponential components have been identified. This study explores the feasibility of estimating these component processes for human listeners with a peripheral model of adaptation. The processes were estimated from off-frequency masked detection data that probed temporal masking responses to a gated narrowband masker. The resulting response patterns reflected step-like onset and offset features with characteristically little evidence of confounding backward and forward masking. The model was implemented with linear combinations of exponential functions to represent the unadapted excitation response to gating the masker on and then off and the opposing effects of adaptation in each instance. The onset and offset of the temporal masking response were assumed to be approximately inverse operations and were modeled independently in this scheme. The unadapted excitation response at masker onset and the reversed excitation response at masker offset were each represented in the model by a single exponential function. The adaptation processes were modeled by three independent exponential functions, which were reversed at masker offset. Each adaptation component was subtractive and partially negated the unadapted excitation response to the dynamic masker. This scheme allowed for quantification of the response amplitude, action latency, and time constant for the unadapted excitation component and for each adaptation component. The results reveal that (1) the amplitudes of the unadapted excitation and reversed excitation components grow nonlinearly with masker level and mirror the 'compressive' input-output velocity response of the basilar membrane; (2) the time constants for the unadapted excitation and reversed excitation components are related inversely to masker intensity, which is compatible with neural synchrony increasing at masker onset (or offset) with increasing masker strength; (3) the composite strength of adaptation levels off at high masker levels; this 'saturation' response is consistent with a diminished contribution from peripheral neural adaptation processes at high sound levels; and (4) the response dynamics for two of the adaptation components correspond generally to those for the 'very rapid'/'rapid' processes and 'short-term' processes described in animal studies of peripheral neural adaptation. The action latency of a third adaptation component suggests the role of a second-order peripheral or central process. This modeling exercise (1) indicates that multiple adaptation processes, whatever their origins, contribute substantively to the form of the temporal masking response and (2) supports a sum-of-exponentials scheme for estimating properties of the component processes.

Chronic estradiol treatment attenuates stiffening, glycoxidation, and permeability in rat carotid arteries

Aging-related changes in vascular stiffening and permeability are associated with cardiovascular disease. We examined the interaction of estradiol on the aging process in vascular tissue from rats by assessing the changes in endothelial layer permeability, arterial compliance, and glycoxidative damage levels. We isolated carotid arteries from ovariectomized (OVX) rats that underwent 1 yr of estrogen treatment with subcutaneous pellets and a subsequent 1 mo of cessation of treatment. Endothelial layer permeability and arterial compliance were determined using quantitative fluorescence microscopy. Endothelial layer permeability was reduced with estradiol treatment (estrogen groups, 2.58 +/- 0.21 ng dextran x min(-1) x cm(-2) vs. nonestrogen groups, 4.01 +/- 0.30 ng dextran x min(-1) x cm(-2); P < 0.05). Additionally, arteries from animals treated with estradiol had an increased compliance index (estrogen groups, 82.9 +/- 3.8 mm2. Torr vs. nonestrogen groups, 69.3 +/- 3.2 mm2. Torr; P < 0.05). Estradiol treatment also reduced levels of pentosidine, which is a specific marker of glycoxidative damage (estrogen groups, 0.11 +/- 0.03 pmol pentosidine/nmol collagen vs. nonestrogen groups, 0.20 +/- 0.03 pmol pentosidine/nmol collagen; P < 0.05). These results indicate that estradiol has multiple chronic vasculoprotective effects on the artery wall to maintain normal vascular wall function.

Early postnatal dexamethasone diminishes transforming growth factor alpha localization within the ileal muscularis propria of newborn mice and extremely low-birth-weight infants

Focal small bowel perforation (FSBP) occurs most commonly in the ileum of extremely low-birth-weight (ELBW) infants. Early postnatal dexamethasone (EPD) administration results in an increased risk for FSBP in this patient population, but the mechanism by which this occurs is unknown. Infants with FSBP have healthy mucosa but thinned smooth muscle, suggesting a mechanism involving the muscularis propria for these perforations. One explanation for these findings would be that dexamethasone alters the tissue availability of pertinent growth factors to the smooth muscle. To explore this possibility, we administered dexamethasone or saline by intraperitoneal injection to newborn mice for 3 days (dosed at 1 microg/g of body weight/day) to simulate EPD protocols. The animals were sacrificed after 72 h of treatment and their ileums harvested and prepared for microscopy. Immunolocalization was performed for three related growth factors (epidermal growth factor [EGF], heparin-binding EGF [h-EGF], and transforming growth factor alpha [TGF-alpha]) and their common receptor. We found TGF-alpha to be abundant and discretely localized in the muscularis propria in control animals but to be diminished in dexamethasone-treated animals. EGF-receptor immunostaining was also decreased with dexamethasone but there was minimal to no detection of EGF or h-EGF in either treatment condition. Surgical and autopsy specimens of the ileum were obtained from seven ELBW infants who either received EPD or not. These tissues were used for immunolocalization of the same growth factors and similar distributions for TGF-alpha were observed in several of these cases. These findings are consistent with an autocrine role for TGF-alpha in ileal smooth muscle proliferation and suggest a mechanism by which EPD might mediate smooth muscle thinning.

Predictors of plasma triglyceride elevation in patients participating in a coronary atherosclerosis treatment program

PURPOSE

Low-fat, high-carbohydrate diets have been used successfully to prevent and treat coronary heart disease, although these diets have been shown to cause elevations in fasting plasma triglyceride concentrations. The present study investigated metabolic factors (glucose, insulin, body weight) associated with changes in plasma triglyceride concentrations in patients participating in a comprehensive, multidisciplinary program, which included the use of a very low-fat diet designed to regress atherosclerotic cardiovascular disease.

METHODS

Thirty-six patients were entered into the study and placed on a 10% fat diet. Body mass index and fasting plasma insulin, glucose, lipids, and apolipoproteins were assessed at entrance into and after 3 months of participation in the program. Statistical analysis (discriminant function analysis) was used to identify factors that predicted elevations in plasma triglyceride that occurred during therapy.

RESULTS

For the entire group, significant reductions in body weight (-2.4%), fasting glucose (-6%), total cholesterol (-8%), and low-density lipoprotein cholesterol (-11%) were observed, while insulin and triglycerides showed no significant changes. Twenty-one of the patients experienced an increase in fasting triglyceride concentration of 10% or greater.

CONCLUSIONS

Three variables (baseline body mass index and fasting triglyceride and insulin concentrations) accurately classified 90% of those who would experience a > or = 10% elevation in triglycerides (P = 0.0002) and 67% of those who experienced no change. The present analysis provides a practical algorithm for clinicians to predict which patients will experience significant elevations in plasma triglyceride concentration when undergoing risk factor reduction that includes the consumption of a very low-fat, high-carbohydrate diet.

Depressive symptoms and risks of coronary heart disease and mortality in elderly Americans. Cardiovascular Health Study Collaborative Research Group

BACKGROUND

Several epidemiological studies have associated depressive symptoms with cardiovascular disease. We investigated whether depressive symptoms constituted a risk for coronary heart disease (CHD) and total mortality among an apparently healthy elderly cohort.

METHODS AND RESULTS

In a prospective cohort of 5888 elderly Americans (>/=65 years) who were enrolled in the Cardiovascular Health Study, 4493 participants who were free of cardiovascular disease at baseline provided annual information on their depressive status, which was assessed using the Depression Scale of the Center for Epidemiological Studies. These 4493 subjects were followed for 6 years for the development of CHD and mortality. The cumulative mean depression score was assessed for each participant up to the time of event (maximum 6-year follow-up). Using time-dependent, proportional-hazards models, the unadjusted hazard ratio associated with every 5-unit increase in mean depression score for the development of CHD was 1.15 (P:=0.006); the ratio for all-cause mortality was 1.29 (P:<0.0001). In multivariate analyses adjusted for age, race, sex, education, diabetes, hypertension, cigarette smoking, total cholesterol, triglyceride level, congestive heart failure, and physical inactivity, the hazard ratio for CHD was 1.15 (P:=0.006) and that for all-cause mortality was 1.16 (P:=0.006). Among participants with the highest cumulative mean depression scores, the risk of CHD increased by 40% and risk of death by 60% compared with those who had the lowest mean scores.

CONCLUSIONS

Among elderly Americans, depressive symptoms constitute an independent risk factor for the development of CHD and total mortality.

Direct visualization of lipid deposition and reverse lipid transport in a perfused artery : roles of VLDL and HDL

The major goal of this study was to determine the interactions of VLDL surface and core lipids with the artery wall. We first demonstrated in vitro that surface lipid in VLDL could be traced using the phospholipid-like fluorescent probe 1,1'-dioctadecyl-3,3, 3',3'-tetramethyl-indocarbocyanine (DiI). The core of VLDL particles was traced by fluorescently labeling apolipoprotein B with TRITC. The labeled VLDLs were perfused through rat carotid arteries, and accumulation of the fluorescently labeled VLDL components in the arterial walls was determined by quantitative fluorescence microscopy. Addition of lipoprotein lipase increased the accumulation of both DiI and TRITC by >2.3-fold. Histological examination showed that DiI and TRITC were primarily localized to the endothelial layer; however, DiI also accumulated as small "lakes" deeper in the artery, in a subendothelial position. Addition of HDL to the perfusion decreased the accumulation of surface lipid and apolipoprotein B-containing particles and eliminated the DiI lakes. Moreover, the increase in endothelial layer permeability associated with lipolysis was attenuated 21% by HDL. If VLDL surface lipid first was allowed to accumulate in the arterial wall, its subsequent rate of loss was more than twice as fast if HDL was included in the perfusate. These studies directly demonstrate atherogenic effects of VLDL lipolysis and their inhibition by HDL.

Smoking and cardiovascular disease

Mainstream and ETS exposure are strong risk factors for cardiovascular disease in men and women. The relationships between smoking and cardiovascular disease result from multiple mechanisms that interact to contribute to atherosclerosis, vascular injury, thrombosis, and vascular dysfunction. We are only now beginning to understand how smoking contributes to the genesis and progression of cardiovascular disease. Because of the complexity of the interactions between nicotine and the components of MSS, ETS, and sidestream smoke with the vasculature, it will take a great deal of time and effort to fully unravel the mechanisms by which smoking contributes to cardiovascular disease. In addition, cardiovascular risk in female smokers is complicated by hormonal variables that may contribute to greater relative risk. It is important that health care providers, educators, and policy makers recognize the changing patterns of smoking and the impact of smoking on cardiovascular disease, and continue campaigns aimed at enhancing smoking cessation in the general population and in teens. Rigorous research is needed on the changing cultural, psychosocial, and environmental factors that influence tobacco use to improve our understanding of racial/ethnic smoking patterns, and identify strategic tobacco control opportunities. The capacity of tobacco control efforts to keep pace with patterns of tobacco use and cessation depends on timely recognition of emerging prevalence and cessation patterns and the resulting development of appropriate community-based programs to address the factors involved. Smoking trends today will determine how heavy the health burden of cardiovascular disease and others will be among communities tomorrow. Programs that aim at early intervention and reflect cultural diversity will be the cornerstone in the battle against tobacco use. Continued interest in research, educational, and prevention efforts are needed to help curb the risk of cardiovascular disease from smoking in men and women.

17beta-estradiol acts separately on the LDL particle and artery wall to reduce LDL accumulation

Estrogen replacement therapy has been shown to attenuate atherogenesis, although the mechanisms for this effect are incompletely defined. Previously, we showed that 17-beta estradiol (estradiol) attenuated oxidant stress-induced increases in vascular low density lipoprotein (LDL) accumulation. It was unclear whether estradiol's effect was imparted on the lipoprotein particle or the artery wall. To examine this, we chronically treated rats with the following sex hormones: low estradiol, high estradiol, progesterone, low estradiol + progesterone, placebo, or control. Carotid arteries (n = 8/group) were isolated and perfused with fluorescently labeled LDL. Rates of LDL accumulation were measured before and after treatment with 10 ng/ml tumor necrosis factor-alpha (TNF) using quantitative fluorescence microscopy. We observed a 50% decrease in basal LDL accumulation rates (P < 0.01) and a 25% decrease in endothelial layer permeability (P < 0.01) in arteries from estradiol-treated animals. There was no effect of hormone replacement on rate of TNF-induced LDL accumulation (P = 0.451), while incubation of LDL with 65 pg/ml estradiol attenuated the TNF effect (P < 0.01). These experiments suggest two independent mechanisms of anti-atherogenic protection by estradiol: 1) decreased endothelial layer permeability; and 2) incorporation of estradiol into the LDL particle and prevention of LDL binding to the artery wall.

The clinical impact of increased sensitivity PT and APTT coagulation assays

To determine how more-sensitive prothrombin time (PT) and activated partial thromboplastin time (aPTT) reagents affected the number and distribution of abnormal test results and whether the increased sensitivity for deficiencies resulted in improved diagnosis of clinically significant coagulopathies, we retrospectively compared preoperative coagulation screening data for 140 children undergoing open heart surgery after the reagent change with a similar group of 135 before the change. The more sensitive reagents resulted in a higher rate of abnormal values, but no increase in the identification of clinically significant hemostatic abnormalities. Of 67 patients with abnormal aPTTs in the group screened with more sensitive reagents, 63 had no further workup. No patients in either group were diagnosed subsequently with a coagulopathy because of unexpected bleeding. An abnormal test result did not predict the need for perioperative blood products. We hypothesize that the high frequency of abnormal aPTTs led to physician "desensitization" about the merit of coagulation screening. Therefore, we question the usefulness of preoperative coagulation screening of the pediatric cardiac surgery patient, particularly since lasting changes in physician perception regarding the clinical significance of abnormal values may lead to missed diagnoses in other settings.

Lifestyle modification program in management of patients with coronary artery disease: the clinical experience in a tertiary care hospital

OBJECTIVES

The authors examined clinical outcomes in 71 male and female patients with coronary atherosclerosis who enrolled in a 2-year, independent-living, lifestyle modification program. The findings in 43 patients who completed the program were compared with those in 28 patients who dropped out of the program.

BACKGROUND

Clinical studies suggest that lifestyle modification of risk factors for coronary atherosclerosis reduces subsequent cardiac events but there are very few reports of the effect of these programs in patients living independently.

METHODS

Patients with diagnosed coronary atherosclerosis were managed for a 2-year period in a structured multidisciplinary program by a team that included two cardiologists, a nurse, a dietitian, an exercise physiologist, and a clinical psychologist. The overall aim of the program was to normalize or control all major reversible cardiovascular risk factors. Patients were required to participate in several weekly sessions for exercise, meditation/stress reduction training, dietary education and counseling, and participatory dinners. There was a strong emphasis on patient's self care, inclusion of support members, and regular monitoring of and feedback to patients.

RESULTS

Data comparing baseline and 2-year outcomes showed a significant reduction in body weight, dietary intake of total/saturated fat and cholesterol, serum low- and high-density lipoprotein concentration, and an increase in exercise capacity. In the compliant group, the incidence of cardiac events was 2.3% over 2 years.

CONCLUSION

Multidisciplinary lifestyle modification programs addressing cardiovascular risk factors are known to have a significant impact upon cardiac risk factors in patients with coronary atherosclerosis. Data show that these changes can be accomplished in independent-living patients in a program offered through a routine cardiology service. However, compliance is an important issue in these self-regulated programs.

17 beta-estradiol reduces glycoxidative damage in the artery wall

Glycoxidative damage in the vasculature has been linked to atherosclerotic cardiovascular disease. Estrogens protect against the development and progression of atherosclerosis. Because estrogens are potent antioxidants that also effect glucose metabolism, part of their protection against atherosclerosis could be through attenuation of glycoxidative damage in the vascular wall. In this study, we tested the hypothesis that chronic estradiol administration is associated with decreased levels of glycoxidative damage in arterial walls. We harvested and examined iliac arteries from ovariectomized, 8-month-old rats that had been implanted for 6 months with 1 of the following subcutaneous hormone pellets: low estradiol (2.5 mg estradiol), high estradiol (25 mg estradiol), P4 (200 mg progesterone), low estradiol and P4, placebo (no hormone), or control (no implant). Using pentosidine as a biomarker of glycoxidative damage, we found that all vessels from rats receiving estradiol (low estradiol, high estradiol, and low estradiol+P4) exhibited a 50% reduction in glycoxidative damage compared with P4, placebo, and control vessels (P<0.05). Consistent with this finding, we observed that estradiol-treated rats had a 30% decrease in tissue levels of hydroperoxides, a marker of oxidative stress. Finally, estradiol-treated rats had a small, but significant, decrease in plasma glucose levels (P<0.01). In summary, we report the novel finding that chronic estrogen administration is associated with significant decreases in glycoxidative damage and oxidative stress in the arterial wall. It seems likely that these actions may constitute a mechanism by which estrogen attenuates the progression of atherosclerosis.

Modified LDL-mediated increases in endothelial layer permeability are attenuated with 17 beta-estradiol

-Current research suggests that estrogen may have primary effects on the artery wall. To investigate the mechanisms of female sex hormone actions in the artery wall, we used an isolated, perfused, rat carotid artery model to examine the effects of estradiol on the rates of accumulation of normal (N-LDL) and minimally modified (MM-LDL) low density lipoprotein in ovariectomized rats. N-LDL, MM-LDL, and oxidized LDL (OX-LDL) were fluorescently labeled and perfused into individual arteries. The rate of LDL accumulation was measured by quantitative fluorescence microscopy before and after treatment with estradiol (1 nmol/L, 272 pg/mL). Estradiol had no effect on the rate of N-LDL accumulation (45+/-12 versus 48+/-15 ng cholesterol per cm2 per h). However, estradiol significantly decreased the rate of MM-LDL (240+/-48 versus 160+/-48 ng cholesterol per cm2 per h; P<0.05) and OX-LDL (191+/-53 versus 112+/-36 ng cholesterol per cm2 per h; P<0.05) accumulation. Further experiments showed that perfusion of unlabeled MM-LDL (100 microgram/mL) increased endothelial layer permeability when the rate of accumulation of a water-soluble, fluorescently labeled, reference molecule (64 000-molecular weight dextran) was determined before and after perfusion of MM-LDL (319+/-96 versus 510+/-191 ng per cm2 per h, n=6 arteries; P<0.05). Estradiol prevented the expected increase in the rate of dextran accumulation when perfused with MM-LDL (control, 415+/-49 ng per cm2 per h and MM-LDL+estradiol, 415+/-160 ng per cm2 per h). Our studies show that estradiol prevents compromise of the endothelial barrier mediated by MM-LDL and attenuates accumulation of MM-LDL in the artery wall.

17beta-estradiol reduces tumor necrosis factor-alpha-mediated LDL accumulation in the artery wall

Estrogens have direct effects on the vascular wall that may prevent the development of atherosclerosis. In particular, estrogens, such as 17beta-estradiol (estradiol), are known to have potent antioxidant activity. Tumor necrosis factor-alpha (TNF) is found in human atheroma and produces oxygen-derived free radicals. These oxygen-derived free radicals may modify low density lipoproteins (LDL) and increase LDL binding in the artery wall. We asked: 1) does TNF increase LDL accumulation in the artery wall and 2) can the TNF-mediated increase in LDL accumulation be prevented by the antioxidant activity of estradiol? Carotid arteries from ovariectomized 3-month-old rats were removed and perfused with fluorescently labeled LDL and arterial LDL flux was measured using quantitative fluorescence microscopy. In six arteries, addition of TNF (10 ng/ml) to the perfusate resulted in a 2.3-fold increase in the rate of LDL accumulation (1.50 +/- 0.37 ng/min per cm2 vs. 3.38 +/- 0.48 ng/min per cm2; P < 0.01). Estradiol (65 pg/ml) and alpha-tocopherol (6 mg/L) both attenuated TNF-mediated LDL accumulation (P < 0.05), indicating that TNF may exert its effects on LDL accumulation through cellular production of oxygen-derived free radicals. These results support an antioxidant role for estradiol in the protection against LDL accumulation in the artery wall and subsequent progression of atherosclerosis.