Medicine and Health Sciences Commons^™

Xk Aprosencephaly And Anencephaly In Sibs, Phillip Townes, Karen Reuter, E. Rosquete, B. Magee

B. Dale Magee

Recent studies have suggested a causal and pathogenetic relationship between holoprosencephaly and anencephaly. In support of the proposed relationship we report a sibship that includes anencephalic male twins and a female infant with a severe form of alobar holoprosencephaly, radial aplasia, and oligodactyly. The upper limb and brain malformations are considered to represent aprosencephaly syndrome. The coexistence of anencephaly and aprosencephaly within a sibship suggests that XK aprosencephaly syndrome may be an autosomal recessive disorder.

Hippocampal Functional Connectivity Patterns During Spatial Working Memory Differ In Right Versus Left Temporal Lobe Epilepsy., Gaelle Eve Doucet, Karol Osipowicz, Ashwini Sharan Md, Michael R Sperling, Joseph I Tracy

Gaelle Eve Doucet

Temporal lobe epilepsy (TLE), affecting the medial temporal lobe, is a disorder that affects not just episodic memory but also working memory (WM). However, the exact nature of hippocampal-related network activity in visuospatial WM remains unclear. To clarify this, we utilized a functional connectivity (FC) methodology to investigate hippocampal network involvement during the encoding phase of a functional magnetic resonance imaging (fMRI) visuospatial WM task in right and left TLE patients. Specifically, we assessed the relation between FC within right and left hippocampus-seeded networks, and patient performance (rate of correct responses) during the encoding phase of a block span WM …

Striatum In Stimulus-Response Learning Via Feedback And In Decision Making., Nole M Hiebert, Andrew Vo, Adam Hampshire, Adrian M Owen, Ken N Seergobin, Penny A Macdonald

Brain and Mind Institute Researchers' Publications

Cognitive deficits are recognized in Parkinson's disease. Understanding cognitive functions mediated by the striatum can clarify some of these impairments and inform treatment strategies. The dorsal striatum, a region impaired in Parkinson's disease, has been implicated in stimulus-response learning. However, most investigations combine acquisition of associations between stimuli, responses, or outcomes (i.e., learning) and expression of learning through response selection and decision enactment, confounding these separate processes. Using neuroimaging, we provide evidence that dorsal striatum does not mediate stimulus-response learning from feedback but rather underlies decision making once associations between stimuli and responses are learned. In the experiment, 11 males …

Burning Pain Secondary To Clozapine Use: A Case Report., Bradley Linton, Rachel Fu, Penny A Macdonald, Hooman Ganjavi

Brain and Mind Institute Researchers' Publications

BACKGROUND: The first of the atypical antipsychotics introduced in the 1970s, clozapine remains the most efficacious neuroleptic to this day. However, serious and potentially fatal side effects have necessitated careful regular monitoring among prescribing clinicians. Some adverse effects (e.g. ischaemic bowel) remain under recognized, while newly identified adverse effects continue to be described in the literature.

CASE PRESENTATION: In this report, we describe a healthy 43-year old Caucasian male who experienced onset of a full body deep burning pain several months after the onset of treatment with clozapine. The pain worsened over time, ceased with cessation of treatment, and returned …

Role Of A Genetic Variant On The 15q25.1 Lung Cancer Susceptibility Locus In Smoking-Associated Nasopharyngeal Carcinoma, Xuemei Ji, Weidong Zhang, Jiang Gui, Xia Fan, Weiwei Zhang, Yafang Li, Guangyu An, Dakai Zhu, Qiang Hu

Dartmouth Scholarship

Background: The 15q25.1 lung cancer susceptibility locus, containing CHRNA5, could modify lung cancer susceptibility and multiple smoking related phenotypes. However, no studies have investigated the association between CHRNA5 rs3841324, which has been proven to have the highest association with CHRNA5 mRNA expression, and the risk of other smoking-associated cancers, except lung cancer. In the current study we examined the association between rs3841324 and susceptibility to smoking-associated nasopharyngeal carcinoma (NPC).

Methods: In this case-control study we genotyped the CHRNA5 rs3841324 polymorphism with 400 NPC cases and 491 healthy controls who were Han Chinese and frequency-matched by age (±5 years), gender, and …

Mirror Reversal And Visual Rotation Are Learned And Consolidated Via Separate Mechanisms: Recalibrating Or Learning De Novo?, Sebastian Telgen, Darius Parvin, Jörn Diedrichsen

Brain and Mind Institute Researchers' Publications

Motor learning tasks are often classified into adaptation tasks, which involve the recalibration of an existing control policy (the mapping that determines both feedforward and feedback commands), and skill-learning tasks, requiring the acquisition of new control policies. We show here that this distinction also applies to two different visuomotor transformations during reaching in humans: Mirror-reversal (left-right reversal over a mid-sagittal axis) of visual feedback versus rotation of visual feedback around the movement origin. During mirror-reversal learning, correct movement initiation (feedforward commands) and online corrections (feedback responses) were only generated at longer latencies. The earliest responses were directed into a nonmirrored …

Barriers And Facilitators For Colorectal Cancer Screening Practices In The Latino Community: Perspectives From Community Leaders, Ana Natale-Pereira, Jonnie Marks, Marielos Vega, Dawne Mouzon, Shawna Hudson, Debbie Salas-Lopez

Debbie Salas-Lopez MD, MPH

BACKGROUND: Colorectal cancer (CRC) is the second-leading cause of cancer-related death in the United States and the third most commonly diagnosed cancer among Latinos. While Latinos represent one of the fastest-growing ethnic groups in the United States, their participation in cancer prevention and treatment trials is low. METHODS: Thirty-six Latino community leaders participated in five focus groups that examined factors affecting CRC screening practices among Latinos. RESULTS: The top four barriers identified were low knowledge and awareness of CRC, language barriers, lack of insurance, and undocumented legal status. Additional barriers included seeking health care only when sick, fatalism, fear, denial …

Perspectives On Cancer Screening Among Latino Community Members And Internal Medicine Residents, Debbie Salas-Lopez, Dawne Mouzon, Jonnie Marks, Neil Kothari, Ana Natale-Pereira

Debbie Salas-Lopez MD, MPH

BACKGROUND: Latinos have lower rates of cancer screening, partially because of cultural beliefs that conflict with those of health care professionals. Moreover, established programs for training physicians in cultural competency often fail to incorporate input from the community.

METHODS: To explore beliefs about cancer and cancer screening among Latino community members and internal medicine residents. Three focus groups of Latino community members (n = 31) and one focus group of internal medicine residents (n = 9) were conducted to compare ideas regarding cancer and cancer screening.

RESULTS: We identified clear disconnects between residents and Latino community members regarding their understandings …

A Dietary-Wide Association Study (Dwas) Of Environmental Metal Exposure In Us Children And Adults, Matthew A. Davis, Diane Gilbert-Diamond, Margaret R. Karagas, Zhigang Li, Jason H. Moore, Scott M. Williams, H. Robert Frost

Dartmouth Scholarship

Background: A growing body of evidence suggests that exposure to toxic metals occurs through diet but few studies have comprehensively examined dietary sources of exposure in US populations.

Purpose: Our goal was to perform a novel dietary-wide association study (DWAS) to identify specific dietary sources of lead, cadmium, mercury, and arsenic exposure in US children and adults.

Methods: We combined data from the National Health and Nutrition Examination Survey with data from the US Department of Agriculture’s Food Intakes Converted to Retail Commodities Database to examine associations between 49 different foods and environmental metal exposure. Using blood and urinary biomarkers …

Human Premotor Areas Parse Sequences Into Their Spatial And Temporal Features., Katja Kornysheva, Jörn Diedrichsen

Brain and Mind Institute Researchers' Publications

Skilled performance is characterized by precise and flexible control of movement sequences in space and time. Recent theories suggest that integrated spatio-temporal trajectories are generated by intrinsic dynamics of motor and premotor networks. This contrasts with behavioural advantages that emerge when a trained spatial or temporal feature of sequences is transferred to a new spatio-temporal combination arguing for independent neural representations of these sequence features. We used a new fMRI pattern classification approach to identify brain regions with independent vs integrated representations. A distinct regional dissociation within motor areas was revealed: whereas only the contralateral primary motor cortex exhibited unique …

Diagnosis Of Pancreatic Neoplasms Using A Novel Method Of Dna Methylation Analysis Of Mucin Expression In Pancreatic Juice., Seiya Yokoyama, Sho Kitamoto, Michiyo Higashi, Yuko Goto, Taro Hara, Dai Ikebe, Taketo Yamaguchi, Yoshifumi Arisaka, Toru Niihara, Hiroto Nishimata, Sadao Tanaka, Kyoichi Takaori, Surinder K. Batra, Suguru Yonezawa

Journal Articles: Biochemistry & Molecular Biology

Mucins (MUC) play crucial roles in carcinogenesis and tumor invasion in pancreatic ductal adenocarcinoma (PDAC) and intraductal papillary mucinous neoplasms (IPMNs). Our immunohistochemistry (IHC) studies have shown a consensus position on mucin expression profiles in pancreatic neoplasms as follows: MUC1-positive but MUC2-negative expression in PDACs; MUC1-negative but MUC2-positive expression in intestinal-type IPMNs (dangerous type); MUC1-negative and MUC2-negative expression in gastric-type IPMNs (safe type); High MUC4 expression in PDAC patients with a poor outcome; and MUC4-positive expression in intestinal-type IPMNs. We also showed that three mucin genes (MUC1, MUC2 and MUC4) expression in cancer cell line was regulated by DNA methylation. …

Effector-Independent Motor Sequence Representations Exist In Extrinsic And Intrinsic Reference Frames., Tobias Wiestler, Sheena Waters-Metenier, Jörn Diedrichsen

Brain and Mind Institute Researchers' Publications

Many daily activities rely on the ability to produce meaningful sequences of movements. Motor sequences can be learned in an effector-specific fashion (such that benefits of training are restricted to the trained hand) or an effector-independent manner (meaning that learning also facilitates performance with the untrained hand). Effector-independent knowledge can be represented in extrinsic/world-centered or in intrinsic/body-centered coordinates. Here, we used functional magnetic resonance imaging (fMRI) and multivoxel pattern analysis to determine the distribution of intrinsic and extrinsic finger sequence representations across the human neocortex. Participants practiced four sequences with one hand for 4 d, and then performed these sequences …

Addressing The Controversy Of Rate-Versus-Rhythm Control In Atrial Fibrillation, Tahmeed Contractor, Vadim Levin, Ravi Desai, Francis E Marchlinski

Vadim A Levin MD

Atrial fibrillation is the most common sustained cardiac arrhythmia and significantly increases patient risk of stroke, cardiomyopathy, and mortality. Rate versus rhythm control as the "best" treatment strategy remains an issue of considerable, ongoing debate. A multitude of clinical trials have compared the 2 strategies and have not shown any benefit of one approach over the other. However, the trials were conducted in specific subgroups of patients and demonstrated low success rates with antiarrhythmic drug (AAD) therapy and a high incidence of adverse AAD effects. Sub-analyses of the trials have confirmed that successful rhythm control with sinus rhythm restoration is …

Addressing The Controversy Of Rate-Versus-Rhythm Control In Atrial Fibrillation, Tahmeed Contractor, Vadim Levin, Ravi Desai, Francis E Marchlinski

Ravi V Desai MD

Atrial fibrillation is the most common sustained cardiac arrhythmia and significantly increases patient risk of stroke, cardiomyopathy, and mortality. Rate versus rhythm control as the "best" treatment strategy remains an issue of considerable, ongoing debate. A multitude of clinical trials have compared the 2 strategies and have not shown any benefit of one approach over the other. However, the trials were conducted in specific subgroups of patients and demonstrated low success rates with antiarrhythmic drug (AAD) therapy and a high incidence of adverse AAD effects. Sub-analyses of the trials have confirmed that successful rhythm control with sinus rhythm restoration is …

Human And Helicobacter Pylori Coevolution Shapes The Risk Of Gastric Disease, Nuri Kodaman, Alvaro Pazos, Barbara G. Schneider, M. Blanca Piazuelo, Robertino Mera, Rafal S. Sobota

Dartmouth Scholarship

Helicobacter pylori is the principal cause of gastric cancer, the second leading cause of cancer mortality worldwide. However, H. pylori prevalence generally does not predict cancer incidence. To determine whether coevolution between host and pathogen influences disease risk, we examined the association between the severity of gastric lesions and patterns of genomic variation in matched human and H. pylori samples. Patients were recruited from two geographically distinct Colombian populations with significantly different incidences of gastric cancer, but virtually identical prevalence of H. pylori infection. All H. pylori isolates contained the genetic signatures of multiple ancestries, with an ancestral African cluster …

Maternal Biomarkers Of Endothelial Dysfunction And Preterm Delivery, Xinhua Chen, Theresa O Scholl

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

BACKGROUND: Endothelial dysfunction is key to the development of atherosclerosis. Preterm delivery foreshadows later maternal cardiovascular disease (CVD), but it is not known if endothelial dysfunction also occurs. We prospectively measured circulating biomarkers of endothelial dysfunction in pregnant women with preterm or term delivery.

METHODS: We conducted a case-control study nested within a large prospective epidemiological study of young, generally healthy pregnant women. Women who delivered preterm (gestation, n = 240) and controls who delivered at term (n = 439) were included. Pregnancies complicated by preeclampsia were analyzed separately. Circulating endothelial dysfunction biomarkers included soluble intercellular adhesion molecule-1 (sICAM-1), vascular …

Response Of An Aggressive Periosteal Aneurysmal Bone Cyst (Abc) Of The Radius To Denosumab Therapy., Chantal Pauli, Bruno Fuchs, Christian Pfirrmann, Julia A. Bridge, Silvia Hofer, Beata Bode

Journal Articles: Pathology and Microbiology

Aneurysmal bone cyst (ABC), once considered a reactive lesion, has been proven to be a neoplasia characterized by rearrangements of the USP6-gene. Aggressive local growth and recurrences are common and therapeutic options may be limited due to the vicinity of crucial structures. We describe a case of a locally aggressive, multinucleated giant cell-containing lesion of the forearm of a 21-year old woman, treated with denosumab for recurrent, surgically uncontrollable disease. Under the influence of this RANKL inhibitor, the tumor showed a marked reduction of the content of the osteoclastic giant cells and an extensive metaplastic osteoid production leading to the …

Observing Object Lifting Errors Modulates Cortico-Spinal Excitability And Improves Object Lifting Performance., Gavin Buckingham, Jeremy D Wong, Minnie Tang, Paul L Gribble, Melvyn A Goodale

Brain and Mind Institute Researchers' Publications

Observing the actions of others has been shown to modulate cortico-spinal excitability and affect behaviour. However, the sensorimotor consequences of observing errors are not well understood. Here, participants watched actors lift identically weighted large and small cubes which typically elicit expectation-based fingertip force errors. One group of participants observed the standard overestimation and underestimation-style errors that characterise early lifts with these cubes (Error video--EV). Another group watched the same actors performing the well-adapted error-free lifts that characterise later, well-practiced lifts with these cubes (No error video--NEV). We then examined actual object lifting performance in the subjects who watched the EV …

Rule-Based Category Learning In Children: The Role Of Age And Executive Functioning., Rahel Rabi, John Paul Minda

Brain and Mind Institute Researchers' Publications

Rule-based category learning was examined in 4-11 year-olds and adults. Participants were asked to learn a set of novel perceptual categories in a classification learning task. Categorization performance improved with age, with younger children showing the strongest rule-based deficit relative to older children and adults. Model-based analyses provided insight regarding the type of strategy being used to solve the categorization task, demonstrating that the use of the task appropriate strategy increased with age. When children and adults who identified the correct categorization rule were compared, the performance deficit was no longer evident. Executive functions were also measured. While both working …

Factors That Contribute To Balance And Mobility Impairments In Individuals With Huntington's Disease, Travis Cruickshank, Alvaro Reyes, Luis Peñailillo, Jennifer Thompson, Mel Ziman

Research outputs 2014 to 2021

Mobility and balance problems are common and often debilitating features of Huntington's disease (HD). In this exploratory study we aimed to investigate the influence of disease severity, severity of motor deficits, lower limb muscle strength, cognition, executive function, lean muscle mass and reactivity on mobility and balance.Twenty-two individuals with HD were recruited from the North Metropolitan Area Mental Health Service, Perth, Australia. Pertinent demographic, genetic and disease progression information was recorded prior to testing. Balance was assessed using dynamic and static balance tasks. Mobility was assessed using self-paced and fast-paced mobility measures. Cognitive and executive measures were used to assess …

Risk Factors For Cerebrovascular Disease Mortality Among The Elderly In Beijing: A Competing Risk Analysis, Zhe Tang, Tao Zhou, Yanxia Luo, Changchun Xie, Da Huo, Lixin Tao, Lei Pan, Fei Sun, Huiping Zhu, Xinghua Yang, Wei Wang, Aoshuang Yan, Xia Li, Xiuhua Guo

Research outputs 2014 to 2021

Objective: To examine the associations of combined lifestyle factors and physical conditions with cerebrovascular diseases (CBVD) mortality, after accounting for competing risk events, including death from cardiovascular diseases, cancers and other diseases. Methods: Data on 2010 subjects aged over 55 years were finally analyzed using competing risk models. All the subjects were interviewed by the Beijing Longitudinal Study of Aging (BLSA), in China, between 1 January 1992 and 30 August 2009. Results: Elderly females were at a lower risk of death from CBVD than elderly males (HR = 0.639, 95% CI = 0.457-0.895). Increasing age (HR = 1.543, 95% CI …

Effect Of Head And Limb Orientation On Trunk Muscle Activation During Abdominal Hollowing In Chronic Low Back Pain, Kevin Parfrey, Sean G. Gibbons, Eric J. Drinkwater, David G. Behm

Research outputs 2014 to 2021

Background: Individuals with chronic low back pain (CLBP) have altered activations patterns of the anterior trunk musculature when performing the abdominal hollowing manœuvre (attempt to pull umbilicus inward and upward towards the spine). There is a subgroup of individuals with CLBP who have high neurocognitive and sensory motor deficits with associated primitive reflexes (PR). The objective of the study was to determine if orienting the head and extremities to positions, which mimic PR patterns would alter anterior trunk musculature activation during the hollowing manoeuvre. Methods. This study compared surface electromyography (EMG) of bilateral rectus abdominis (RA), external oblique (EO), and …

Anxiety Symptoms, Cerebral Amyloid Burden And Memory Decline In Healthy Older Adults Without Dementia: 3-Year Prospective Cohort Study, Robert H. Pietrzak, J C. Scott, Alexander Neumeister, Yen Ying Lim, David Ames, Kathyrn A. Ellis, Kara Harrington, Nicola T. Lautenschlager, Cassandra Szoeke, Ralph Martins, Colin L. Masters, Victor L. Villemagne, Christopher C. Rowe, Paul Maruff

Research outputs 2014 to 2021

Although beta-amyloid, anxiety and depression have been linked cross-sectionally to reduced memory function in healthy older adults without dementia, prospective data evaluating these associations are lacking. Using data from an observational cohort study of 178 healthy older adults without dementia followed for 3 years, we found that anxiety symptoms significantly moderated the relationship between beta-amyloid level and decline in verbal (Cohen's d = 0.65) and episodic (Cohen's d = 0.38) memory. Anxiety symptoms were additionally linked to greater decline in executive function, irrespective of beta-amyloid and other risk factors. These findings suggest that interventions to mitigate anxiety symptoms may help …

Comparison Of Cutaneous Mastocytosis With Onset In Children And Adults, Serap Güneş Bi̇lgi̇li̇, Ayşe Serap Karadağ, Zennure Takci, Ömer Çalka, Mustafa Kösem

Turkish Journal of Medical Sciences

Mastocytosis is a heterogeneous group of diseases characterized by the abnormal infiltration of mast cells in the skin and sometimes other organs. This study aimed to compare the demographic, clinical, and histopathological findings of cutaneous mastocytosis with onset in children and in adults. Materials and methods: Patients diagnosed with cutaneous mastocytosis in 2 different dermatology clinics between 2007 and 2011 were included in the study. Demographic characteristics of the patients as well as localization and type of the cutaneous lesions, presence of symptoms, Darier's sign, family history, systemic involvement, and histopathological evaluations were retrospectively examined. Results: Out of the 30 …

What Are Ventilation Defects In Asthma?, Sarah Svenningsen, Miranda Kirby, Danielle Starr, Harvey O Coxson, Nigel A M Paterson, David G Mccormack, Grace Parraga

Medical Biophysics Publications

BACKGROUND: Hyperpolarised (3)He MRI provides a way to visualise regional pulmonary functional abnormalities that in asthma are thought to be related to airway morphological abnormalities. However, the exact aetiology of ventilation defects in asthma is not well understood.

OBJECTIVE: To better understand the determinants of ventilation defects in asthma, we evaluated well-established clinical as well as (3)He MRI and X-ray CT airway measurements in healthy subjects and subjects with asthma.

METHODS: Thirty-four subjects (n=26 subjects with asthma, n=8 healthy volunteers) underwent MRI, spirometry, plethysmography, fraction of exhaled nitric oxide analysis, methacholine challenge and CT for a region-of-interest proximal to ventilation …