Germ-line DNA copy number variation frequencies in a large North American population

Genomic copy number variation (CNV) is a recently identified form of global genetic variation in the human genome. The Affymetrix GeneChip 100 and 500 K SNP genotyping platforms were used to perform a large-scale population-based study of CNV frequency. We constructed a genomic map of 578 CNV regions, covering approximately 220 Mb (7.3%) of the human genome, identifying 183 previously unknown intervals. Copy number changes were observed to occur infrequently (<1%) in the majority (>93%) of these genomic regions, but encompass hundreds of genes and disease loci. This North American population-based map will be a useful resource for future genetic studies. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

A polyvalent vaccine for high-risk prostate patients: “are more antigens better?”

We have shown the immunogenicity and safety of synthetic carbohydrate vaccines when conjugated to the carrier keyhole limpet hemocyanin (KLH) and given with the adjuvant, QS-21, in patients with biochemically relapsed prostate cancer. To determine whether immune response could be further enhanced with stimulation by multiple antigens, a hexavalent vaccine was prepared using previously determined doses and administered in a Phase II setting to 30 high-risk patients. The hexavalent vaccine included GM2, Globo H, Lewis^y, glycosylated MUC-1-32mer and Tn and TF in a clustered formation, conjugated to KLH and mixed with QS-21. Eight vaccinations were administered over 13 months. All 30 patients had significant elevations in antibody titers to at least two of the six antigens; 22 patients had increased reactivity with FACS. These serologic responses were lower than that seen previously in patients treated with the respective monovalent vaccines. The reciprocal median combined IgM and IgG antibody titers with ELISA against MUC1, Tn, TF, globo H and GM2 for these 30 patients were 640, 80, 120, 40 and 0, compared to 1280, 640, 1280, 320 and 160 seen in patients receiving individual monovalent vaccines. This hexavalent vaccine of synthetic “self” antigens broke immunologic tolerance against two or more antigens in all 30 vaccinated patients, was safe, but antibody titers against several of the antigens were lower than those seen in individual monovalent trials. No impact on PSA slope was detected. We address the relevance of the multivalent approach for prostate cancer treatment. Supported by the Prostate Cancer Foundation, The PepsiCo Foundation, The Sharon Hels and Brad Reed Fund, Swim Across America, The Sara Chait Foundation. Dr. Philip Livingston is a consultant for and shareholder in Progenics Pharmaceuticals, Inc.     

Linkage and association analysis of candidate genes for TB and TNFα cytokine expression: evidence for association with IFNGR1, IL-10, and TNF receptor 1 genes

Tuberculosis (TB) is a growing public health threat globally and several studies suggest a role of host genetic susceptibility in increased TB risk. As part of a household contact study in Kampala, Uganda, we have taken a unique approach to the study of genetic susceptibility to TB by developing an intermediate phenotype model for TB susceptibility, analyzing levels of tumor necrosis factor-α (TNFα) in response to culture filtrate as the phenotype. In the present study, we analyzed candidate genes related to TNFα regulation and found that interleukin (IL)-10, interferon-gamma receptor 1 (IFNGR1), and TNFα receptor 1 (TNFR1) genes were linked and associated to both TB and TNFα. We also show that these associations are with progression to active disease and not susceptibility to latent infection. This is the first report of an association between TB and TNFR1 in a human population and our findings for IL-10 and IFNGR1 replicate previous findings. By observing pleiotropic effects on both phenotypes, we show construct validity of our intermediate phenotype model, which enables the characterization of the role of these genetic polymorphisms on TB pathogenesis. This study further illustrates the utility of such a model for disentangling complex traits. C. C. Whalen and S. K. Iyengar contributed equally as senior authors of this work.     

Blood pressure regulation in neurally intact human vs. acutely injured paraplegic and tetraplegic patients during passive tilt

We investigated autonomic control of cardiovascular function in able-bodied (AB), paraplegic (PARA), and tetraplegic (TETRA) subjects in response to head-up tilt following spinal cord injury. We evaluated spectral power of blood pressure (BP), baroreflex sensitivity (BRS), baroreflex effectiveness index (BEI), occurrence of systolic blood pressure (SBP) ramps, baroreflex sequences, and cross-correlation of SBP with heart rate (HR) in low (0.04-0.15 Hz)- and high (0.15-0.4 Hz)-frequency regions. During tilt, AB and PARA effectively regulated BP and HR, but TETRA did not. The numbers of SBP ramps and percentages of heartbeats involved in SBP ramps and baroreflex sequences increased in AB, were unchanged in PARA, and declined in TETRA. BRS was lowest in PARA and declined with tilt in all groups. BEI was greatest in AB and declined with tilt in all groups. Low-frequency power of BP and the peak of the SBP/HR cross-correlation magnitude were greatest in AB, increased during tilt in AB, remained unchanged in PARA, and declined in TETRA. The peak cross-correlation magnitude in HF decreased with tilt in all groups. Our data indicate that spinal cord injury results in decreased stimulation of arterial baroreceptors and less engagement of feedback control as demonstrated by lower 1) spectral power of BP, 2) number (and percentages) of SBP ramps and barosequences, 3) cross-correlation magnitude of SBP/HR, 4) BEI, and 5) changes in delay between SBP/HR. Diminished vasomotion and impaired baroreflex regulation may be major contributors to decreased orthostatic tolerance following injury.     

An integrated view of oxidative stress in aging: basic mechanisms, functional effects, and pathological considerations

Aging is an inherently complex process that is manifested within an organism at genetic, molecular, cellular, organ, and system levels. Although the fundamental mechanisms are still poorly understood, a growing body of evidence points toward reactive oxygen species (ROS) as one of the primary determinants of aging. The "oxidative stress theory" holds that a progressive and irreversible accumulation of oxidative damage caused by ROS impacts on critical aspects of the aging process and contributes to impaired physiological function, increased incidence of disease, and a reduction in life span. While compelling correlative data have been generated to support the oxidative stress theory, a direct cause-and-effect relationship between the accumulation of oxidatively mediated damage and aging has not been strongly established. The goal of this minireview is to broadly describe mechanisms of in vivo ROS generation, examine the potential impact of ROS and oxidative damage on cellular function, and evaluate how these responses change with aging in physiologically relevant situations. In addition, the mounting genetic evidence that links oxidative stress to aging is discussed, as well as the potential challenges and benefits associated with the development of anti-aging interventions and therapies.     

Excretion and conservation of glycerol, and expression of aquaporins and glyceroporins, during cold acclimation in Cope's gray tree frog Hyla chrysoscelis

Cope's gray tree frog Hyla chrysoscelis accumulates glycerol during cold acclimation. We hypothesized that, during this process, gray tree frogs adjust renal filtration and/or reabsorption rates to retain accumulated glycerol. During cold acclimation, plasma concentrations of glycerol rose >200-fold, to 51 mmol/l. Although fractional water reabsorption decreased, glomerular filtration rate (GFR) and, consequently, urine flow were <5% of warm levels, and fractional glycerol reabsorption increased. In contrast, dehydrated frogs increased fractional water reabsorption, decreased GFR, and did not accumulate glycerol. We hypothesized that expression of proteins from the aquaporin (AQP)/glyceroporin (GLP) family was associated with changing patterns of water and glycerol movement. We cloned the cDNA for three such proteins, quantified mRNA expression in nine tissues using real-time quantitative PCR, and functionally characterized them using a Xenopus oocyte expression system. HC-1, an AQP1-like water channel conferring low glycerol permeability, is expressed ubiquitously in warm- and cold-acclimated tissues. HC-2, a water channel most similar to AQP2, is primarily expressed in organs of osmoregulation. HC-3, which is most similar to AQP3, is functionally characterized as a GLP, with low permeability to water but high permeability to glycerol. Aspects of expression levels and functional characteristics varied between cold and warm conditions for each of the three AQPs, suggesting a complex pattern of involvement in osmoregulation related to thermal acclimation.     

Exercise training improves myocardial tolerance to ischemia in male but not in female rats

Acute exercise increases myocardial tolerance to ischemia-reperfusion (I-R) injury in male but not in female rat hearts, possibly due to a decreased heat shock protein 70 (Hsp70) response in the female hearts. This study examined whether repetitive exercise training would increase Hsp70 and myocardial tolerance to I-R injury in female rat hearts. Adaptations in myocardial manganese superoxide dismutase (MnSOD) and endothelial nitric oxide synthase (eNOS) were also assessed. Ten-week old male (M) and female (F) Sprague-Dawley rats (n = 40 total) exercise-trained for 14 wk; the last 8 wk consisted of running 1 h at 30 m/min (2% incline), 5 days/wk. Following training, left ventricle mechanical function (LVMF) was monitored for 30 min of reperfusion following 30 min of global ischemia (Langendorff procedure). Myocardial Hsp70 content was not different in M and F control groups, while increases were observed in both trained groups (M greater than F; P < 0.05). Although MnSOD content did not differ between groups, endothelial nitric oxide synthase (eNOS) levels were decreased in F, with no change in M, following training (P < 0.05). Hearts from control F demonstrated a greater recuperation of all indices of LVMF following I-R compared with control M hearts (P < 0.05). Hearts of trained M exhibited improved recovery of LVMF (left ventricular diastolic pressure, left ventricular end-diastolic pressure, +dP/dt, -dP/dt) during reperfusion compared with control M hearts (P < 0.05). In contrast, hearts of trained F did not show any change in recovery from I-R. Hence, exercise training is more beneficial to M than F in improving myocardial function following I-R injury.     

Inhibitors of hepatitis C virus NS3.4A protease. Effect of P4 capping groups on inhibitory potency and pharmacokinetics

Reversible tetrapeptide-based compounds have been shown to effectively inhibit the hepatitis C virus NS3.4A protease. Inhibition of viral replicon RNA production in Huh-7 cells has also been demonstrated. We show herein that the inclusion of hydrogen bond donors on the P4 capping group of tetrapeptide-based inhibitors result in increased binding potency to the NS3.4A protease. The capping groups also impart significant effects on the pharmacokinetic profile of these inhibitors.     

3,4-Dihydro-2H-benzoxazinones as dual-acting 5-HT1A receptor antagonists and serotonin reuptake inhibitors

Investigation of halogen substitution in lead compound 1 has led to the identification of analogues which combine high affinity for 5-HT(1A) receptors and potent serotonin reuptake inhibitory activity. Several compounds show an improved selectivity over 5-HT(1B) and 5-HT(1D) receptors and a superior pharmacokinetic profile in the rat.     

Amino-caprolactam derivatives as gamma-secretase inhibitors

A series of amino-caprolactam sulfonamides were developed from a screening hit. Compounds with good in vitro and in vivo gamma-secretase activity are reported.