The apolipoprotein E gene, attention, and brain function

The epsilon4 allele of the apolipoprotein E (ApoE) gene is associated with alterations in brain function and is a risk factor for Alzheimer's disease (AD). Changes in components of visuospatial attention with ApoE-epsilon4, aging, and AD are described. Healthy middle-aged adults without dementia who have the ApoE-epsilon4 gene show deficits in spatial attention and working memory that are qualitatively similar to those seen in clinically diagnosed AD patients. The findings support an association between ApoE polymorphism and specific components of visuospatial attention. Molecular mechanisms that may mediate the ApoE-attention link by modulating cholinergic neurotransmission to the posterior parietal cortex are discussed. Studies of attention and brain function in ApoE-epsilon4 carriers without dementia can advance knowledge of the genetics of visual attention, may enhance understanding of the preclinical phase of AD, and may lead to better methods for early AD detection.     

Health Literacy,Self-Efficacy,and Patients' Assessment of Medical Disclosure and Consent Documentation

Informed consent documents are designed to convey the risks of medical procedures to patients, yet they are often difficult to understand; this is especially true for individuals with limited health literacy. An important opportunity for advancing knowledge about health literacy and informed consent involves examining the theoretical pathways that help to explain how health literacy relates to information processing when patients read consent forms. In this study, we proposed and tested a model that positioned self-efficacy as a mediator of the association between health literacy and patients' comprehension and assessment of informed consent documentation. Findings from structured interviews with patients (n?=?254) indicated that lower health literacy predicted lower self-efficacy, which predicted feeling less well informed and less prepared, being more confused about the procedure and its hazards, and wanting more information about risks. Incorporating awareness of self-efficacy into disclosure documents and consent conversations may be a useful means of prompting patients to ask questions that can help them make informed decisions about care.     

Evaluation of anti-thrombomodulin antibody as a tumor marker for vascular neoplasms

BACKGROUND: Various endothelial markers are available for the evaluation of vascular tumors and malformations, including anti CD34, anti-CD31, von Willebrand factor (vWF), and anti-thrombomodulin (anti-TM) antibodies. All have their limitations, and we sought to compare the utility of anti-TM antibody as a marker for several types of vascular neoplasms vs. previously established endothelial markers. METHODS: We examined immunostaining profiles of 30 capillary hemangiomas, 10 pyogenic granulomas, five tufted angiomas, 17 Kaposi's sarcomas, and nine angiosarcomas. Immunostains for TM, CD34, and vWF were carried out using a labeled streptavidin-biotin peroxidase detection system. RESULTS: Anti-TM antibody showed moderately intense immunostaining in 89% of benign and malignant vascular neoplasms. Anti-CD34 antibody showed moderate to diffuse immunostaining in 98% of vascular neoplasms, and vWF showed weak focal staining in 84% of all vascular neoplasms examined. CONCLUSION: Anti-TM antibody proved to be a sensitive marker for both benign and malignant vascular neoplasms. While not as sensitive as anti-CD34, it may have some advantages in specificity that would make it a more reliable vascular tumor marker in certain situations.     

Amyloid-β associated cortical thinning in clinically normal elderly

Objective:

Both amyloid‐β (Aβ) deposition and brain atrophy are associated with Alzheimer's disease (AD) and the disease process likely begins many years before symptoms appear. We sought to determine whether clinically normal (CN) older individuals with Aβ deposition revealed by positron emission tomography (PET) imaging using Pittsburgh Compound B (PiB) also have evidence of both cortical thickness and hippocampal volume reductions in a pattern similar to that seen in AD.

Methods:

A total of 119 older individuals (87 CN subjects and 32 patients with mild AD) underwent PiB PET and high‐resolution structural magnetic resonance imaging (MRI). Regression models were used to relate PiB retention to cortical thickness and hippocampal volume.

Results:

We found that PiB retention in CN subjects was (1) age‐related and (2) associated with cortical thickness reductions, particularly in parietal and posterior cingulate regions extending into the precuneus, in a pattern similar to that observed in mild AD. Hippocampal volume reduction was variably related to Aβ deposition.

Interpretation:

We conclude that Aβ deposition is associated with a pattern of cortical thickness reduction consistent with AD prior to the development of cognitive impairment. ANN NEUROL 2010;     

Children of persons with Alzheimer disease: what does the future hold?

Children of persons with Alzheimer disease (AD), as a group, face an increased risk of developing AD. Many of them, throughout their adult lives, seek input on how to reduce their chances of one day suffering their parent's fate. We examine the state of knowledge with respect to risk and protective factors for AD and recommend a research agenda with special emphasis on AD offspring.     

Age and amyloid-related alterations in default network habituation to stimulus repetition

The neural networks supporting encoding of new information are thought to decline with age, although mnemonic techniques such as repetition may enhance performance in older individuals. Accumulation of amyloid-β, one hallmark pathology of Alzheimer's disease (AD), may contribute to functional alterations in memory networks measured with functional magnetic resonance imaging (fMRI) prior to onset of cognitive impairment. We investigated the effects of age and amyloid burden on fMRI activity in the default network and hippocampus during repetitive encoding. Older individuals, particularly those with high amyloid burden, demonstrated decreased task-induced deactivation in the posteromedial cortices during initial stimulus presentation and failed to modulate fMRI activity in response to repeated trials, whereas young subjects demonstrated a stepwise decrease in deactivation with repetition. The hippocampus demonstrated similar patterns across the groups, showing task-induced activity that decreased in response to repetition. These findings demonstrate that age and amyloid have dissociable functional effects on specific nodes within a distributed memory network, and suggest that functional brain changes may begin far in advance of symptomatic Alzheimer's disease.     

Preoperative upper endoscopy is useful before revisional bariatric surgery.

BACKGROUND AND OBJECTIVES: We hypothesized that patients who have previously had bariatric surgery and are undergoing revision to laparoscopic Roux-en-Y gastric bypass would have abnormal findings detected by upper endoscopy that could potentially influence patient management. The procedures that are being revised include vertical banded gastroplasty, laparoscopic adjustable gastric bands, nonadjustable gastric bands and previous Roux-en-Y gastric bypass (open and laparoscopic). METHODS: We conducted a retrospective chart review of patients who previously had undergone vertical banded gastroplasty or nonadjustable gastric banding. We preoperatively performed an upper endoscopy on all patients. The endoscopy reports were reviewed and the findings entered into a database. RESULTS: Eighty-five percent of 46 patients undergoing revisional bariatric surgery had an abnormal upper endoscopy. Eleven percent had a gastrogastric fistula. Gastritis and esophagitis were noted in 65% and 37%, respectively. Eleven percent of patients had band erosion, 2 from a nonadjustable band, and 5 from vertical banded gastroplasties. Based on our findings, 65% of our patients required medical treatment. CONCLUSIONS: Preoperative upper endoscopy provides valuable information before revisional laparoscopic bariatric surgery. In addition to identifying patients who need preoperative medications, the preoperative upper endoscopy also provided valuable information regarding pouch size and anatomy. Preoperative upper endoscopy should be performed by the operating surgeon on every patient undergoing revisional bariatric surgery.