Metamorphosis Imposes Variable Constraints on Genome Expansion through Effects on Development.

Genome size varies ∼100,000-fold across eukaryotes and has long been hypothesized to be influenced by metamorphosis in animals. Transposable element accumulation has been identified as a major driver of increase, but the nature of constraints limiting the size of genomes has remained unclear, even as traits such as cell size and rate of development co-vary strongly with genome size. Salamanders, which possess diverse metamorphic and non-metamorphic life histories, join the lungfish in having the largest vertebrate genomes-3 to 40 times that of humans-as well as the largest range of variation in genome size. We tested 13 biologically-inspired hypotheses exploring how the form of metamorphosis imposes varying constraints on genome expansion in a broadly representative phylogeny containing 118 species of salamanders. We show that metamorphosis during which animals undergo the most extensive and synchronous remodeling imposes the most severe constraint against genome expansion, with the severity of constraint decreasing with reduced extent and synchronicity of remodeling. More generally, our work demonstrates the potential for broader interpretation of phylogenetic comparative analysis in exploring the balance of multiple evolutionary pressures shaping phenotypic evolution.

Developing major histocompatibility markers in a species of concern: the Sacramento perch Archoplites interruptus.

Primers targeting two non-neutral major histocompatibility complex (mhc) II ß genes were developed and assayed across several disjoint Sacramento perch Archoplites interruptus sampling locations. Variability at the two mhc loci among sampling stocks strongly correlated to previous estimates with neutral markers, suggesting that the effect of genetic drift was not limited to neutrally evolving regions of the genome. The novel mhc primers will help develop admixture schemes in A. interruptus captive breeding programmes and will increase the success of future reintroductions of this species of concern.

Improvement in aortic valve area using a new "hour glass" shaped valvuloplasty balloon compared with standard cylindrical balloons in severe aortic stenosis patients.

AIM: Balloon aortic valvuloplasty (BAV) has reemerged with transcatheter valve therapy. Cylindrical balloons have been the device of choice despite limitations. An hour glass shaped balloon may permit enhanced fixation and broader leaflet opening without annular compromise. METHODS: We report our initial BAV experience using the V8 balloon (InterValve Inc.) in 20 consecutive patients compared to 20 patients from a 403-patient BAV database using cylindrical balloons. Patients were propensity matched on a 1:1 basis by age, gender, left ventricular ejection fraction (LVEF), baseline aortic valve area (AVA) and Society of Thoracic Surgery (STS) mortality risk score. End points included change in AVA and aortic insufficiency (AI) by echocardiography. New atrioventricular conduction defects (AVCD), need for post procedure pacemaker were documented. Major adverse events (MAE) included procedure related death, emergency surgery or stroke. RESULTS: V8 and cylindrical balloon groups were similar across age, gender, LVEF, AVA and STS score. The change in AVA from baseline to post-procedure strongly trended towards being larger in the V8 group than cylindrical balloon group (mean [SD]; 0.30±0.23 cm2 vs. 0.17±0.21 cm2; P=0.063). There were no differences in outcomes for degree of AI, AVCD, need for pacemaker or MAE. CONCLUSION: Preliminary findings in this small experience suggest an advantage for enhancing AVA when using the V8 compared with cylindrical balloons. Additionally, there was no evidence of increased AI, AVCD or MAE.

Estrogen or raloxifene during postmenopausal weight loss: adiposity and cardiometabolic outcomes.

OBJECTIVE: Estrogen-based hormone therapy (HT) attenuates abdominal fat gain after menopause, but whether HT improves abdominal fat loss during weight loss is unknown. It was hypothesized that HT or a selective estrogen receptor modulator (raloxifene) would augment reductions in abdominal visceral fat during weight loss when compared to placebo, potentially increasing improvements in glucose tolerance and lipid profile. METHODS: Healthy postmenopausal women (n = 119; age 50-70 yr) underwent a 6-month weight-loss (primarily exercise) intervention with randomization to raloxifene (60 mg/d), HT (conjugated estrogens, 0.625 mg/d), or placebo. Outcomes were change in total and abdominal (visceral and subcutaneous) fat mass, lipid profile, and fasting and post-challenge glucose and insulin. RESULTS: Neither HT nor raloxifene augmented loss of total or abdominal fat mass during exercise-induced weight loss when compared with placebo. Weight loss-induced improvements in risk factors were similar among the three groups, except for a greater reduction in fasted glucose in the HT group (difference in change [95%CI] from placebo; -0.40 [-0.76, -0.05]) and greater reductions in LDL (-0.36 [-0.63, -0.09]) and increases in HDL (0.15 [0.07, 0.24]) in both treatment groups. CONCLUSIONS: Postmenopausal HT and raloxifene did not increase abdominal fat loss during weight loss, but did improve some cardiometabolic outcomes.

Defining vitamin D status by secondary hyperparathyroidism in the U.S. population.

BACKGROUND: Vitamin D is associated with a variety of health outcomes, but the exact definition of vitamin D sufficiency remains controversial. AIM: We sought to define skeletal-related vitamin D sufficiency by estimating maximum PTH suppression in the U.S. population. METHODS: We performed a cross-sectional analysis of the National Health and Nutrition Examination Survey (NHANES), 2003-2006. We examined the association between serum 25-hydroxyvitamin D (25OHD) level and serum PTH level in 14,681 participants aged ≥6 yr. We also evaluated the 25OHD-PTH association using 2 thresholds of hyperparathyroidism: PTH≥45 pg/ml and ≥75 pg/ml. RESULTS: The mean 25OHD level was 24 ng/ml and mean PTH was 42 pg/ml. PTH≥45 pg/ml was present in 35% of the population, while PTH≥75 pg/ml was present in 7%. The prevalence of 25OHD levels <40 ng/ml and <30 ng/ml was 95% and 77%, respectively. In both unadjusted and adjusted models, there was a strong inverse relationship between 25OHD and PTH. Compared to 25OHD≥40 ng/ml, the 25OHD-PTH association was 2.36 [95% confidence interval (CI), 2.08-2.67] times greater for 25OHD<5 ng/ml and 1.12 (95%CI, 1.07-1.17) times greater for 25OHD 30-39.9 ng/ml. Compared to 25OHD≥40 ng/ml, 25OHD levels of 20- 29.9 ng/ml [odds ratio (OR) 2.0 (95%CI, 1.4-2.8)] but not 30- 39.9 ng/ml [OR 1.1 (95%CI, 0.8-1.6)] were independently associated with PTH≥45 pg/ml. CONCLUSIONS: Optimal vitamin D status, defined by estimated maximum PTH suppression, does not occur until at least 25OHD levels ≥40 ng/ml. Using these thresholds, most of the U.S. population needs more vitamin D. Large, prospective studies are needed to determine optimal vitamin D supplementation.

Dehydroepiandrosterone sulfate and cognitive function in the elderly: The InCHIANTI Study.

DHEA and its sulfate derivative (DHEAS) decline with age. The decline in DHEAS levels has been associated with many physiological impairments in older persons including cognitive dysfunction. However, data regarding the possible relationship between DHEAS and cognition are scant. We investigated whether DHEAS levels are associated with presence and development of lower cognitive function measured by the Mini Mental State Examination (MMSE) in older men and women. One thousand and thirty-four residents aged > or =65 yr of the InCHIANTI Study with data available on DHEAS and MMSE were randomly selected. MMSE was administered at baseline and 3 yr later. Among these, 841 completed a 3-yr follow-up. Parsimonious models obtained by backward selection from initial fully-adjusted models were used to identify independent factors associated with MMSE and DHEAS. The final analysis was performed in 755 participants (410 men and 345 women) with MMSE score > or =21. A significant age-related decline of both DHEAS levels (p<0.001) and MMSE score (p<0.001) was found over the 3-yr follow-up. At enrolment, DHEAS was significantly and positively associated with MMSE score, independently of age and other potential confounders (beta+/-SE 0.003+/-0.001, p<0.005). Low baseline DHEAS levels were predictive of larger decline of MMSE and this relationship was significant after adjusting for covariates (beta+/-SE -0.004+/-0.002, p<0.03). Our data show a significant and positive association between DHEAS and cognitive function, assessed by MMSE test. Low DHEAS levels predict accelerated decline in MMSE score during the 3-yr follow-up period.

Utility of magnetic resonance imaging in diagnosing ulnar neuropathy at the elbow.

OBJECTIVE: Magnetic resonance imaging (MRI) of the ulnar nerve is being increasingly employed in the diagnosis of ulnar neuropathy at the elbow (UNE). Our aims were to: (i) assess the sensitivity of MRI in diagnosing UNE, especially in cases where neurophysiologic studies were non-localizing, (ii) determine the spectrum of MRI abnormalities in patients presenting with symptoms and signs of ulnar neuropathy, (iii) assess whether MRI findings differ between grades of UNE severity, and (iv) to see if MRI findings give an input into the pathological mechanisms of UNE. METHODS: Clinical, neurophysiologic, and radiologic (MRI) records were reviewed in 52 patients with symptoms and signs of ulnar neuropathy. Ulnar nerve MRI studies were assessed by an unblinded observer. RESULTS: The sensitivity of MRI at diagnosing UNE was higher than conventional nerve conduction studies, 90 versus 65%, respectively. In patients with non-localizing neurophysiologic studies (n=19), MRI disclosed changes consistent with UNE in 16 (84%) cases. The most frequent MRI findings included a combination of high signal intensity and nerve enlargement (63%), followed by nerve compression (27%) and isolated high signal intensity (23%), and isolated nerve enlargement (2%). There was no significant difference between patients with localizing and non-localizing neurophysiologic testing. Lastly, there were no differences between different grades of UNE, suggesting that UNE may be a neurophysiologically heterogeneous disorder. CONCLUSIONS: MRI studies proved to be more sensitive than conventional nerve conduction studies at diagnosing UNE. In addition, the MRI studies were highly sensitive in patients with non-localizing UNE. SIGNIFICANCE: Our study shows that MRI of the ulnar nerve should be used in patients with clinical features of UNE especially in those with non-localizing neurophysiologic testing.

Lower-body adiposity and metabolic protection in postmenopausal women.

CONTEXT: It has been suggested that the propensity to store fat in the gluteal-femoral region may be cardioprotective. OBJECTIVE: The primary aim of this study was to test whether the favorable associations of leg fat with risk factors for cardiovascular disease persist after controlling for the highly unfavorable effects of abdominal (visceral or sc) adiposity in postmenopausal women. STUDY PARTICIPANTS: The study included 95 postmenopausal women [age, 60 +/- 8 yr (mean +/- SD)]. MAIN OUTCOMES: Whole-body and regional fat distribution was measured using dual-energy x-ray absorptiometry and abdominal computed tomography. Markers of insulin resistance and dyslipidemia were determined from oral glucose tolerance tests and fasted lipid and lipoprotein measurements, respectively. Primary outcomes were: fasting insulin (INS0), area under the insulin curve (INS(AUC)), product of the oral glucose tolerance test insulin and glucose AUC (INS(AUC) - GLU(AUC)), serum triglycerides (TG), and high-density lipoprotein (HDL) cholesterol. RESULTS: Controlling for trunk fat revealed a favorable effect of leg fat on INS0, INS(AUC), INS(AUC) x GLU(AUC), TG, and HDL. However, after controlling for either visceral or sc abdominal adiposity, TG was the only risk factor for which the favorable effect of leg fat persisted. CONCLUSIONS: The lack of an association between leg fat and most of the risk factors, after adjusting for abdominal visceral or sc fat, suggests an overriding deleterious influence of abdominal adiposity on cardiovascular risk. Nevertheless, our finding that regional adipose tissue depots have apparent independent and opposing effects on serum TG supports the need for further research into the physiological mechanisms governing these effects.

Protection of bone mass by estrogens and raloxifene during exercise-induced weight Loss.

The aim of this study was to determine whether estrogen and/or raloxifene help to conserve bone mineral density (BMD) during moderate weight loss. Postmenopausal women (n = 68) participated in a 6-month weight loss program that consisted primarily of supervised exercise training. Another 26 women were studied over 6 months of weight stability. All participants were randomized to three treatment arms: placebo, raloxifene (60 mg/d), or hormone therapy (HT; conjugated estrogens, 0.625 mg/d; trimonthly medroxyprogesterone acetate, 5 mg/d for 13 d, for women with a uterus). Changes in body weight (mean +/- se) averaged 0.8 +/- 0.5 kg in the weight-stable group and -4.1 +/- 0.4 kg in the weight loss group. Across all measured skeletal sites, average changes in BMD in weight stable women were -0.6 +/- 1.1% (n = 7), 0.9 +/- 0.6% (n = 9), and 3.0 +/- 0.7% (n = 10) in the placebo, raloxifene, and HT groups, respectively; comparable BMD changes in the weight loss groups were -1.5 +/- 0.5% (n = 22), -0.5 +/- 0.5% (n = 23), and 1.1 +/- 0.4% (n = 23). There were no significant interactions between weight loss and drug treatment on changes in BMD, but there were significant main effects of weight loss on lumbar spine (P = 0.022), total hip (P = 0.010), and trochanter BMD (P < 0.001). These findings suggest that weight loss, even when modest in magnitude and induced by exercise training, causes a reduction in BMD, particularly in women not taking raloxifene or HT. It is not known whether reductions in BMD of this magnitude increase the risk for osteoporotic fracture.

Intravenous estrogens increase insulin clearance and action in postmenopausal women.

To test the hypothesis that estrogens alter insulin action, we evaluated the effects of intravenous conjugated estrogens (CE) on insulin-stimulated steady-state glucose infusion rate (SSGIR) and suppression of plasma glycerol in postmenopausal women (mean +/- SD; 56 +/- 4 yr; n = 12) not using hormone replacement. SSGIR and glycerol were measured during a two-stage (8 and 40 mU. m-2. min-1) hyperinsulinemic euglycemic clamp on 2 days, with or without a 2.5-mg intravenous CE bolus. Serum estradiol concentrations were increased approximately 200% on the estrogen (EST) compared with the control (CON) days. Serum insulin was reduced (P < 0.01) during stage 2 of the clamp for EST (63.3 +/- 12.8 micro U/ml) vs. CON (78.2 +/- 15.8 micro U/ml). Mean SSGIR and plasma glycerol did not differ between CON and EST days. With adjustment for differences in insulin concentration between conditions, stage 2 glucose disposals were significantly higher (8.63 vs. 7.20 mg. kg-1. min-1) and plasma glycerol concentrations were significantly lower (29.4 vs. 35.0 micro mol/l) for EST vs. CON. Our findings suggest that acute CE administration increases insulin clearance and action in postmenopausal women.

Reproductive fitness in maternal homocystinuria due to cystathionine beta-synthase deficiency.

Early diagnosis and improved treatment are leading to the potential for increased reproductive capability in homocystinuria due to cystathionine beta-synthase (CbetaS) deficiency, but information about reproductive outcome and risk of thromboembolism in pregnancy is limited. To provide further information, clinical and biochemical information was obtained on women with maternal homocystinuria, on their pregnancies and on the offspring. This information included blood sulphur amino acids and total homocysteine, CbetaS gene mutations and developmental and cognitive scores in the offspring. The study involved 15 pregnancies in 11 women, of whom 5 were pyridoxine-nonresponsive and 6 were pyridoxine-responsive. Complications of pregnancy included pre-eclampsia at term in two pregnancies and superficial venous thrombosis of the leg in a third pregnancy. One pregnancy was terminated and two pregnancies resulted in first-trimester spontaneous abortions. The remaining 12 pregnancies produced live-born infants with normal or above-normal birth measurements. One offspring has multiple congenital anomalies that include colobomas of the iris and choroid, neural tube defect and undescended testes. He is also mentally retarded and autistic. A second offspring has Beckwith-Wiedemann syndrome. The remaining 10 offspring were normal at birth and have remained normal. There was no relationship between the severity of the biochemical abnormalities or the therapies during pregnancy to either the pregnancy complications or the offspring outcomes. The infrequent occurrences of pregnancy complications, offspring abnormalities and maternal thromboembolic events in this series suggest that pregnancy and outcome in maternal homocystinuria are usually normal. Nevertheless, a cautious approach would include careful monitoring of these pregnancies with attention to metabolic therapy and possibly anticoagulation.

New approaches to the pharmacological treatment of angina.

The treatment of angina is changing, with many new agents being added to those existing agents that have been used for many years. New data regarding the use of glycoprotein IIb/IIIa inhibitors now exist and low molecular weight heparins are used more frequently with greater efficacy than unfractionated heparin. New thrombin inhibitors are also receiving a fresh look. An expert panel has recently published guidelines for the treatment of unstable angina.

Pregnancy-associated plasma protein A as a marker of acute coronary syndromes.

BACKGROUND: Circulating markers indicating the instability of atherosclerotic plaques could have diagnostic value in unstable angina or acute myocardial infarction. We evaluated pregnancy-associated plasma protein A (PAPP-A), a potentially proatherosclerotic metalloproteinase, as a marker of acute coronary syndromes. METHODS: We examined the level of expression of PAPP-A in eight culprit unstable coronary plaques and four stable plaques from eight patients who had died suddenly of cardiac causes. We also measured circulating levels of PAPP-A, C-reactive protein, and insulin-like growth factor I (IGF-I) in 17 patients with acute myocardial infarction, 20 with unstable angina, 19 with stable angina, and 13 controls without atherosclerosis. RESULTS: PAPP-A was abundantly expressed in plaque cells and extracellular matrix of ruptured and eroded unstable plaques, but not in stable plaques. Circulating PAPP-A levels were significantly higher in patients with unstable angina or acute myocardial infarction than in patients with stable angina and controls (P<0.001). A PAPP-A threshold value of 10 mlU per liter identified patients who had acute coronary syndromes with a sensitivity of 89.2 percent and a specificity of 81.3 percent. PAPP-A levels correlated with levels of C-reactive protein and free IGF-I, but not with markers of myocardial injury (troponin I and the MB isoform of creatine kinase). CONCLUSIONS: PAPP-A is present in unstable plaques, and circulating levels are elevated in acute coronary syndromes; these increased levels may reflect the instability of atherosclerotic plaques. PAPP-A is a new candidate marker of unstable angina and acute myocardial infarction.

Evaluation of the coronary venous system using electron beam computed tomography.

New therapeutic strategies in interventional cardiology and electrophysiology involve the coronary veins. This study examines the potential usefulness of electron beam computed tomography to obtain detailed noninvasive definition of the coronary venous anatomy and of arteriovenous relationships. Electron beam computed tomography allows acquisition and three-dimensional reconstruction of tomographic images of the beating heart with high spatial and temporal resolution. Contrast-enhanced, thin-section electron beam computed tomographic coronary arteriographic images of 34 patients (21 men and 13 women, age 60+/-10 years) were analyzed. The visibility of the coronary veins and their spatial relationship to the coronary arteries were assessed qualitatively on two- and three-dimensional displays. The coronary sinus was visible in 91%, the great cardiac vein in 100%, the middle cardiac vein in 88%, at least one vein overlying the lateral surface of the left ventricle in 97%, the anterior interventricular vein in 97%, and the small cardiac vein in 68%. A left marginal and a left posterior vein were seen in 44%, one of the two in 38%, and neither in 3%. The course of the anterior interventricular vein was parallel to the left anterior coronary artery in 79% and a crossover between the two vessels at an obtuse angle occurred in 12%. Contrast-enhanced electron beam computed tomography imaging of the heart noninvasively provides information on the coronary venous system and arteriovenous relationships that may help guide new interventional procedures.

Pressure rinsing of coronary stents immediately before implantation reduces inflammation and neointimal hyperplasia.

OBJECTIVES: This study evaluates whether rinsing stents with high pressure immediately before implantation minimizes stent-induced inflammation and neointimal formation. BACKGROUND: Several reports indicate that manual stent manipulation before implantation results in foreign body contamination and increased neointimal hyperplasia. METHODS: A stent-cleaning chamber was developed to rinse stents at a sustained hydrodynamic pressure of 4 atm for 10 s. Commercial pre-mounted stents were examined with different levels of manipulation: 1) untouched stents: no stent manipulation before implantation; 2) handled stents: manual stent re-crimping on the balloon; 3) rinsed stents: pressure-rinsed with the stent-cleaning chamber. In vitro surface analysis was evaluated by scanning electron microscopy. Neointimal hyperplasia and inflammation around stent struts were also assessed in the pig in-stent restenosis model. RESULTS: In vitro analysis revealed fewer contaminants on rinsed stents compared with untouched (p = 0.01) and handled stents (p < 0.001). In vivo, neointimal thickness, neointimal area and vessel percent stenosis were significantly reduced in rinsed, compared with not-rinsed, stents (p = 0.002, p = 0.007, p = 0.008 respectively). In addition, a significant reduction in the inflammatory infiltrate around struts was observed in untouched, compared with handled, stents (p = 0.04) and in rinsed, compared with not-rinsed, stents (p < 0.001). Regression analysis accounting for injury and neointimal thickness showed significant differences in slopes between "handled + not-rinsed" and "handled + rinsed" stents (p = 0.004), and between "untouched + not-rinsed" and "untouched + rinsed stents" (p = 0.037). CONCLUSIONS: Rinsing stents under high pressure immediately before coronary implantation results in less inflammation around struts and thinner neointima at 28 days in this pig model.

Long-term prognostic value of coronary calcification detected by electron-beam computed tomography in patients undergoing coronary angiography.

BACKGROUND: Electron-beam CT (EBCT) quantification of coronary artery calcification (CAC) allows noninvasive assessment of coronary atherosclerosis. We undertook a follow-up study to determine whether CAC extent, measured at the time of angiography by EBCT, predicted future hard cardiac events, comprising cardiac death and nonfatal myocardial infarction (MI). We also assessed the potential of selected coronary artery disease (CAD) risk factors, prior CAD event history (MI or revascularization), and angiographic findings (number of diseased vessels and overall disease burden) to predict subsequent hard events. METHODS AND RESULTS: Two hundred eighty-eight patients who underwent contemporaneous coronary angiography and EBCT scanning were contacted after a mean of 6.9 years. Vital status and history of MI during follow-up were determined. Cox proportional hazards models were used to compare the predictive ability of CAC extent with selected CAD risk factors, CAD event history, and angiographic findings. Median CAC score was 160 (range 0 to 7633). The 22 patients who experienced hard events during follow-up were older and had more extensive CAC and angiographic disease (P<0.05). Only 1 of 87 patients with CAC score <20 experienced a subsequent hard event during follow-up. Event-free survival was significantly higher for patients with CAC scores <100 than for those with scores >/=100 (relative risk 3.20; 95% CI 1.17 to 8.71). When a stepwise multivariable model was used, only age and CAC extent predicted hard events (risk ratios 1.72 and 1.88, respectively; P<0.05). CONCLUSIONS: In patients undergoing angiography, CAC extent on EBCT is highly predictive of future hard cardiac events and adds valuable prognostic information.

Comparison of self-expanding and balloon-expandable stents for the reduction of restenosis.

To compare the efficacy of self-expanding (SE) and balloon-expandable (BE) stents in native coronary arteries, we randomly assigned 1,096 patients with new and restenotic lesions to receive either device. Baseline demographics and coronary angiographic characteristics were similar in the 2 groups. The incidence of major adverse cardiac events including death, myocardial infarction, bypass surgery, and repeat intervention was similar for both groups at 1 month (2.9% vs 3.1% for SE vs BE, respectively) and at 9 months (19.3% vs 20.1%, SE vs BE respectively). In a subgroup of patients who underwent follow-up angiography (n = 250), the binary restenosis rates (24.2% vs 18.7%, p = 0.30), late loss (0.98 vs 94 mm, p = 0.60), and loss index (0.55 vs 55, p = 0.95) were not significantly different for both groups. In 62 patients who underwent intravascular ultrasound examination (IVUS), there was a trend toward a lower incidence of edge tears in the SE group (6% vs 23%, p = 0.06). Follow-up IVUS analysis showed that the minimum stent area of the SE stent increased by 33% at 6 months, whereas no change occurred in the BE stents; this was accompanied by a greater degree of intimal proliferation in the SE stents compared with BE stents (3.1 +/- 2.0 vs 1.7 +/- 1.7 mm(2)). Thus, the SE stents had similar clinical and angiographic outcomes in patients with lesions in native coronary arteries.