Citations

Phenylethanolamine N-methyltransferase (PNMT) catalyzes the synthesis of epinephrine from norepinephrine. We previously identified and functionally characterized common sequence variation in the PNMT gene. In the present study, we set out to determine whether common PNMT genetic polymorphisms might be associated with individual variation in circulating epinephrine levels during exercise in 74 Caucasian American subjects. Circulating epinephrine levels were measured in each subject at baseline and during two different levels of exercise, ∼40% and ∼75% of peak workload. The PNMT gene was resequenced with DNA from each study subject. Eight novel PNMT polymorphisms were identified, including a C319T (Arg107Cys) nonsynonymous single nucleotide polymorphism (SNP) and I1G(280)A, a SNP located in the first intron of the gene. The I1G(280)A SNP was significantly associated with decreased exercise-induced circulating epinephrine levels and with a decreased epinephrine-to-norepinephrine ratio. The Cys107 recombinant allozyme displayed significantly lower levels of both PNMT activity and immunoreactive protein than the wild-type allozyme after transfection into COS-1 cells, but it did not appear to be associated with level of epinephrine in these subjects. Electrophoretic mobility shift and reporter gene assays performed with the I1G(280)A SNP indicated that this polymorphism could bind nuclear proteins and might modulate gene transcription. Our studies suggest that functionally significant variant sequence in the human PNMT gene might contribute to individual variation in levels of circulating epinephrine during exercise.

Alzheimer's disease (AD) is associated with regional reductions in fluorodeoxyglucose positron emission tomography (FDG PET) measurements of the cerebral metabolic rate for glucose, which may begin long before the onset of histopathological or clinical features, especially in carriers of a common AD susceptibility gene. Molecular evaluation of cells from metabolically affected brain regions could provide new information about the pathogenesis of AD and new targets at which to aim disease-slowing and prevention therapies. Data from a genome-wide transcriptomic study were used to compare the expression of 80 metabolically relevant nuclear genes from laser-capture microdissected non-tangle-bearing neurons from autopsy brains of AD cases and normal controls in posterior cingulate cortex, which is metabolically affected in the earliest stages; other brain regions metabolically affected in PET studies of AD or normal aging; and visual cortex, which is relatively spared. Compared with controls, AD cases had significantly lower expression of 70% of the nuclear genes encoding subunits of the mitochondrial electron transport chain in posterior cingulate cortex, 65% of those in the middle temporal gyrus, 61% of those in hippocampal CA1, 23% of those in entorhinal cortex, 16% of those in visual cortex, and 5% of those in the superior frontal gyrus. Western blots confirmed underexpression of those complex I–V subunits assessed at the protein level. Cerebral metabolic rate for glucose abnormalities in FDG PET studies of AD may be associated with reduced neuronal expression of nuclear genes encoding subunits of the mitochondrial electron transport chain.

Background and Purpose— Evidence supports a substantial genetic contribution to the risk of intracranial aneurysm (IA). The purpose of this study was to identify chromosomal regions likely to harbor genes that contribute to the risk of IA. Methods— Multiplex families having at least 2 individuals with “definite” or “probable” IA were ascertained through an international consortium. First-degree relatives of individuals with IA who were at increased risk of an IA because of a history of hypertension or present smoking were offered cerebral magnetic resonance angiography. A genome screen was completed using the Illumina 6K SNP system, and the resulting data from 192 families, containing 1155 genotyped individuals, were analyzed. Narrow and broad disease definitions were used when testing for linkage using multipoint model-independent methods. Ordered subset analysis was performed to test for a gene×smoking (pack-years) interaction. Results— The greatest evidence of linkage was found on chromosomes 4 (LOD=2.5; 156 cM), 7 (LOD=1.7; 183 cM), 8 (LOD=1.9; 70 cM), and 12 (LOD=1.6; 102 cM) using the broad disease definition. Using the average pack-years for the affected individuals in each family, the genes on chromosomes 4 (LOD=3.5; P =0.03), 7 (LOD=4.1; P =0.01) and 12 (LOD=3.6; P =0.02) all appear to be modulated by the degree of smoking in the affected members of the family. On chromosome 8, inclusion of smoking as a covariate did not significantly strengthen the linkage evidence, suggesting no interaction between the loci in this region and smoking. Conclusions— We have detected possible evidence of linkage to 4 chromosomal regions. There is potential evidence for a gene×smoking interaction with 3 of the loci.

AbstractPerformance of patients with quadrant lesions on the inherently ambiguous Cognitive Bias Task (CBT) suggests sexual dimorphism in the fundamental aspects of functional cortical geometry, by emphasizing different cerebral axes. In right-handed males, extreme context-dependent and context-independent response selection biases are reciprocally linked to left vs. right frontal systems. In right-handed females, these complementary biases appear to be reciprocally linked to posterior vs. frontal cortices. Frontal lobe functions are more lateralized in males than females due to sexual dimorphism of the left frontal systems. Both in males and females, patterns of CBT scores in non-right-handers with quadrant lesions are opposite to those found in right-handers. This suggests the existence of two functionally and neurally distinct cognitive selection mechanisms. Both mechanisms involve the frontal lobes, but their exact neuroanatomy depends on sex and handedness.

Alzheimer's Disease (AD) is the most widespread form of dementia during the later stages of life. If improved therapeutics are not developed, the prevalence of AD will drastically increase in the coming years as the world's population ages. By identifying differences in neuronal gene expression profiles between healthy elderly persons and individuals diagnosed with AD, we may be able to better understand the molecular mechanisms that drive AD pathogenesis, including the formation of amyloid plaques and neurofibrillary tangles. In this study, we expression profiled histopathologically normal cortical neurons collected with laser capture microdissection (LCM) from six anatomically and functionally discrete postmortem brain regions in 34 AD-afflicted individuals, using Affymetrix Human Genome U133 Plus 2.0 microarrays. These regions include the entorhinal cortex, hippocampus, middle temporal gyrus, posterior cingulate cortex, superior frontal gyrus, and primary visual cortex. This study is predicated on previous parallel research on the postmortem brains of the same six regions in 14 healthy elderly individuals, for which LCM neurons were similarly processed for expression analysis. We identified significant regional differential expression in AD brains compared with control brains including expression changes of genes previously implicated in AD pathogenesis, particularly with regard to tangle and plaque formation. Pinpointing the expression of factors that may play a role in AD pathogenesis provides a foundation for future identification of new targets for improved AD therapeutics. We provide this carefully phenotyped, laser capture microdissected intraindividual brain region expression data set to the community as a public resource.

Abstract Some autoimmune disorders are increasingly recognized as risk factors for non-Hodgkin lymphoma (NHL) overall, but large-scale systematic assessments of risk of NHL subtypes are lacking. We performed a pooled analysis of self-reported autoimmune conditions and risk of NHL and subtypes, including 29 423 participants in 12 case-control studies. We computed pooled odds ratios (OR) and 95% confidence intervals (CI) in a joint fixed-effects model. Sjögren syndrome was associated with a 6.5-fold increased risk of NHL, a 1000-fold increased risk of parotid gland marginal zone lymphoma (OR = 996; 95% CI, 216-4596), and with diffuse large B-cell and follicular lymphomas. Systemic lupus erythematosus was associated with a 2.7-fold increased risk of NHL and with diffuse large B-cell and marginal zone lymphomas. Hemolytic anemia was associated with diffuse large B-cell NHL. T-cell NHL risk was increased for patients with celiac disease and psoriasis. Results for rheumatoid arthritis were heterogeneous between studies. Inflammatory bowel disorders, type 1 diabetes, sarcoidosis, pernicious anemia, and multiple sclerosis were not associated with risk of NHL or subtypes. Thus, specific autoimmune disorders are associated with NHL risk beyond the development of rare NHL subtypes in affected organs. The pattern of associations with NHL subtypes may harbor clues to lymphomagenesis.

Purpose To assess cardiac safety and potential cardiac risk factors associated with trastuzumab in the NCCTG N9831 Intergroup adjuvant breast cancer trial. Patients and Methods Patients with HER2-positive operable breast cancer were randomly assigned to doxorubicin plus cyclophosphamide (AC) followed by either weekly paclitaxel (arm A); paclitaxel then trastuzumab (arm B); or paclitaxel plus trastuzumab then trastuzumab alone (arm C). Left ventricular ejection fraction (LVEF) was evaluated at registration and 3, 6, 9, and 18 to 21 months. Results Of 2,992 patients completing AC, 5.0% had LVEF decreases disallowing trastuzumab (decrease below normal: 2.4%, decrease > 15%: 2.6%). There were 1,944 patients with satisfactory or no LVEF evaluation who proceeded to post-AC therapy. Cardiac events (congestive heart failure [CHF] or cardiac death [CD]): arm A, n = 3 (2 CHF, 1 CD); arm B, n = 19 (18 CHF, 1 CD); arm C, n = 19 (all CHF); 3-year cumulative incidence: 0.3%, 2.8%, and 3.3%, respectively. Cardiac function improved in most CHF cases following trastuzumab discontinuation and cardiac medication. Factors associated with increased risk of a cardiac event in arms B and C: older age (P < .003), prior/current antihypertensive agents (P = .005), and lower registration LVEF (P = .033). Incidence of asymptomatic LVEF decreases requiring holding trastuzumab was 8% to 10%; LVEF recovered and trastuzumab was restarted in approximately 50%. Conclusion The cumulative incidence of post-AC cardiac events at 3 years was higher in the trastuzumab-containing arms versus the control arm, but by less than 4%. Older age, lower registration LVEF, and antihypertensive medications are associated with increased risk of cardiac dysfunction in patients receiving trastuzumab following AC.

Abstract Purpose: To test combination treatment schedules of reovirus and radiation in human and murine tumor cells in vitro and in vivo. Experimental Design: In vitro cytotoxicity and cell cycle effects of reovirus given alone and combined with radiotherapy were assessed by colorimetric, tissue culture infectious dose 50, and fluorescence-activated cell sorting–based assays. Interactions between the agents were evaluated using combination index analysis. The effect of different schedules of reovirus and radiotherapy on viral replication and cytotoxicity was tested in vitro and the combination was assessed in three tumor models in vivo. Results: Characterization of reovirus cytotoxicity in a panel of cell lines yielded a range of sensitivities. Combined reovirus and radiotherapy yielded statistically significantly increased cytotoxicity, particularly in cell lines with moderate susceptibility to reovirus alone. The enhanced cytotoxicity of the combination occurred independently of treatment sequence or schedule. Radiation did not affect viral replication and only reduced reoviral cytotoxicity after clinically irrelevant single doses (&gt;50 Gy). Combination index analysis revealed synergy between radiation (3-10 Gy) and reovirus at multiplicities of infection between 0.001 and 1. Combination treatment significantly increased apoptosis in tumor cells relative to either single-agent treatment. In vivo studies using xenograft and syngeneic tumors showed enhanced activity of the combination relative to reovirus or radiation alone (P &lt; 0.001). Conclusions: Combining reovirus and radiotherapy synergistically enhances cytotoxicity in a variety of tumor cells in vitro and in vivo. These results offer strong support for translational clinical trials of reovirus plus radiotherapy that have been initiated in the clinic.