Digital Commons Network^™

Science Classics, Mark Masthay

Chemistry Faculty Publications

An essay on the impact of the works in the Imprints and Impressions: Milestones in Human Progress, an exhibition of rare books from the collection of Stuart Rose. Exhibition was held Sept. 29-Nov. 9, 2014, at the University of Dayton.

An Analysis Of Abnormal Electrocardiograms In First And Second Year Medical School Students, Molly Anne Kalish

PCOM Biomedical Studies Student Scholarship

The high stress level placed upon medical school students, particularly during their first and second didactic years, may have a negative effect on their health. Although surveys and subjective questionnaires have been used to evaluate the effects medical school has upon a student’s cardiovascular health, there has been little clinical data obtained to confirm this notion. The aim of this longitudinal study was to demonstrate whether any abnormal cardiovascular parameters, specifically QTc wave interval, cardiac axis vector and blood pressure abnormalities, could be documented to occur in two different classes of medical students during their first two years. Such information …

Evaluation Of Tissue-Engineered Tendon Enthesis Polymer Constructs, Joshua A. Bundy Bs, Mary Beth Wade Phd, Hitomi Nakao Md, Phillip Mcclellan Phd, Qing Yu Phd, Robin Jacquet-Childs Ms, William J. Landis Phd

Williams Honors College, Honors Research Projects

Both scientists and clinicians have proposed tissue engineering as the future of medicine. The possibilities for tissue engineering, that is, fabrication of tissues and organs in the laboratory and their translation to patients, appear to be endless, and many believe that this new approach in medicine will result in abolishing many common ailments, injuries, and congenital defects. Injuries to a tendon enthesis, the normal tissue connection between tendon and bone, are of particular concern to clinicians because of their frequency and failure to repair as a result of surgery. While these injuries may not be life threatening, they can certainly …

Transmural Heterogeneity Of Cellular Level Cardiac Contractile Properties In Aging And Heart Failure, Premi Haynes

Theses and Dissertations--Physiology

The left ventricle of the heart relaxes when it fills with blood and contracts to eject blood into circulation to meet the body’s metabolic demands. Dysfunction in either relaxation or contraction of the left ventricle can lead to heart failure. Transmural heterogeneity is thought to contribute to normal ventricular wall motion but it is not well understood how transmural modifications affect the failing left ventricle. The overall hypothesis of this dissertation is that normal left ventricles exhibit transmural heterogeneity in cellular level contractile properties and with aging and heart failure there are region-specific changes in cellular level contractile mechanisms.

Age …

Comparison Of The Effect Of Two Human Milk Fortifiers On Clinical Outcomes In Premature Infants, Melissa Thoene, Corrine K. Hanson, Elizabeth Lyden, Laura Dugick, Leslie Ruybal, Ann Anderson-Berry

Journal Articles: Nebraska Medicine

The use of human milk fortifiers (HMF) helps to meet the high nutritional requirements of the human milk-fed premature infant. Previously available powdered products have not met the protein requirements of the preterm infant population and many neonatologists add powder protein modulars to help meet protein needs. The use of powdered products is discouraged in neonatal intensive care units (NICU) due to concern for invasive infection. The use of a commercially available acidified liquid product with higher protein content was implemented to address these two concerns. During the course of this implementation, poor growth and clinically significant acidosis of infants …

Endobronchial Ultrasound-Guided Transbronchial Needle Biopsy For The Diagnosis Of Mediastinal Lymphadenopathy In Patients With Extrathoracic Malignancies, Ayşegül Şentürk, Hati̇ce Kiliç, Habi̇be Hezer, Funda Karaduman Yalçin, Hati̇ce Canan Hasanoğlu

Turkish Journal of Medical Sciences

Mediastinal lymphadenopathy is common in extrathoracic malignancies and should not always be considered a metastatic lesion. The purpose of this study is to determine the diagnostic value of endobronchial ultrasound-guided transbronchial needle biopsy (EBUS-TBNA) in patients with extrathoracic malignancies. Materials and methods: This study included 54 consecutive patients with extrathoracic malignancies who had suspected mediastinal metastases and had undergone EBUS-TBNA for diagnosis. Results: Using EBUS-TBNA, 27 of 54 patients (50%) were diagnosed with mediastinal metastases. Among patients with mediastinal metastases, 2 (3.7%) had a sarcoid-like reaction, 5 (9.3%) had tuberculosis, and 17 (31.5%) had reactive lymph nodes. In 3 cases …

The Role Of Fdg-Pet/Ct In Detecting Unsuspected And Unknown Distant Metastasis In The Initial Staging Of Nsclc, Meti̇n Halaç, Meftune Özhan, Sabi̇re Yilmaz Aksoy, Betül Vatankulu, Anar Aliyev, Sertaç Asa, Ersan Atahan, Muhammet Sai̇t Sağer, Keri̇m Sönmezoğlu

Turkish Journal of Medical Sciences

Our purpose in this retrospective study was to determine the ratio of unexpected [metastases within the coverage area of thorax computed tomography (CT)] and unknown (metastases out of the coverage area of thorax CT) metastases by positron emission tomography/CT (PET/CT) in patients with newly diagnosed non-small cell lung cancer (NSCLC) who had no defined metastatic lesion, and to investigate the contribution of fludeoxyglucose (FDG)-PET/CT in metastasis staging. Materials and methods: A total of 567 patients (489 males and 78 females, mean age 60.9 ± 10.7 years) were enrolled in this study. Among the 567 patients, a total of 156 patients …

A General Consideration Of The Importance Of Nutrition For Critically Ill Patients, Ersi̇n Gürkan Dumlu, Mesut Özdedeoğlu, Bi̇rkan Bozkurt, Mehmet Tokaç, Abdussamed Yalçin, Levent Öztürk, Mehmet Kiliç

Turkish Journal of Medical Sciences

Malnutrition is a common medical condition among intensive care unit patients. It should be monitored carefully, since early management of malnutrition can dramatically improve the medical condition of the patients. A general consideration of enteral feeding shows that it is much more useful than parenteral administration, because it is more physiological and poses a lower risk of hyperalimentation. Materials and methods: In this retrospective study, we scanned all files and personal information of patients hospitalized in intensive care units between 2009 and 2012 due to various medical conditions. We evaluated the nutritional status of patients with biochemical parameters that were …

Relationship Between Placental Localisation, Birth Weight, Umbilical Doppler Parameters, And Foetal Sex, Müzeyyen Duran Erdolu, Aydin Köşüş, Nermi̇n Köşüş, Gülçi̇n Di̇lmen, Hasan Kafali

Turkish Journal of Medical Sciences

The aim of this study is to examine the relationship between placental localisation, birth weight, and foetal sex. It also evaluates umbilical artery Doppler parameters and their relationship with placental localisation. Materials and methods: This is a retrospective study of 500 healthy pregnant women who gave birth at our university. All women had undergone a detailed ultrasound and Doppler examination at 20-23 weeks. The ultrasonography results of the patients were examined retrospectively. Foetal biometry, birth weight, and umbilical artery Doppler parameters were recorded and compared according to placental localisation. Results: Birth weight was significantly higher in foetuses with anteriorly located …

What Is The Best Radiological Method To Predict The Actual Weight Of The Prostate?, Meti̇n Kiliç, Ahmet Tunç Özdemi̇r, Serkan Altinova, Ali̇ Fuat Atmaca, Abdullah Erdem Canda, Mevlana Derya Balbay

Turkish Journal of Medical Sciences

We compared the weight of the prostate specimen extracted after radical prostatectomy with preoperatively estimated weights of the prostate by different imaging techniques. Materials and methods: Prostate weights were estimated by transabdominal ultrasonography (TAUS), transrectal ultrasonography (TRUS), and computed tomography (CT) preoperatively before radical prostatectomy. Prostatectomy specimens were weighed postoperatively and the actual prostate weights were calculated. Statistical analyses were done using 95% confidence intervals with repeated measurement analysis of variance and intraclass correlation coefficients. Results: Of the 163 patients enrolled in the study, the mean age was 64.2 ± 6.4 (range: 45 to 76) years. The mean postoperative prostate …

Choroidal Thickness In Healthy Turkish Subjects, Erol Coşkun, Seydi̇ Okumuş, Bülent Gürler, Ramazan Yayuspayi, Burak Ören, Erdal Kaydu, Ayşegül Çömez, İbrahi̇m Erbağci

Turkish Journal of Medical Sciences

To investigate choroidal thickness in healthy Turkish subjects. Materials and methods: Refraction, axial length (AXL) measurement, anterior chamber, and fundus examinations were performed. Eyes that had any retinal or choroidal pathology were excluded from the study. Enhanced-depth imaging optical coherence tomography was used to evaluate choroidal thickness. Results: 139 eyes from 70 subjects were investigated. The mean age, AXL, spherical equivalent refractive error (SE), and subfoveal choroidal thickness (SCT) were 34.7 ± 12.7 years, 23.31 ± 0.91 mm, -0.15 ± 1.64 diopters (D), and 326 ± 60 µm, respectively. A negative correlation was found between SCT and AXL (P = …

The Diagnostic Value Of Ischemia-Modified Albumin In The Diagnosis Of Aortic Pathology, Oğuz Eroğlu, Süha Türkmen, Ahmet Menteşe, Gökalp Altun, Süleyman Türedi̇, Umut Eryi̇ği̇t, Süleyman Caner Karahan, Abdülkadi̇r Gündüz

Turkish Journal of Medical Sciences

To investigate the diagnostic value of ischemia-modified albumin (IMA) in the diagnosis of patients with aortic aneurysm. Materials and methods: The study group consisted of 98 patients who presented to our university hospital emergency department with aortic pathology and were definitively diagnosed using spiral tomography. The control group consisted of 101 healthy individuals with similar demographic characteristics. Results: Mean IMA values were 0.89 ± 0.21 absorbance units (ABSU) in the aortic aneurysm group (P < 0.001), 0.70 ± 0.12 ABSU in the aortic dissection group (P < 0.001), 0.98 ± 0.23 ABSU in the aneurysm and dissection group (P < 0.001), 0.84 ± 0.16 ABSU in the aneurysm and rupture group (P < 0.001), and 0.87 ± 0.27 ABSU in the aneurysm, dissection, and rupture group (P < 0.001). Mean IMA value for the subjects in the control group was 0.62 ± 0.17 ABSU. All the differences between the aortic pathology groups' IMA values and those of the control group were statistically significant (P < 0.001). Conclusion: On the basis of the findings from this study, serum IMA levels are higher in patients with aortic pathology compared to healthy individuals. This finding suggests that IMA may help to diagnose aortic pathology, but it requires confirmation by additional clinical studies.

Comparison Of The Effects Of Different Percutaneous Tracheotomy Techniques On Acute Tracheal Trauma, Cengi̇z Beki̇r Demi̇rel, Hacer Haltaş, Hasan Kutluk Pampal, Yusuf Ünal, Berri̇n Işik, Mükerrem Uysal

Turkish Journal of Medical Sciences

As it can easily be performed at the bedside with minimal morbidity, percutaneous dilatational tracheotomy (PDT) is preferred over surgical tracheotomy. The aim of this study is to compare the effects of different PDT techniques on posterior tracheal wall injury. Materials and methods: The study was conducted at the Gazi University Laparoscopy Training Center after approval was granted by the ethics committee. After sedation with xylazine/ketamine, electrocardiography, peripheral oxygen saturation, and blood pressure were monitored. Propofol was used to achieve the desired level of sedation during the procedure. There were 16 pigs, randomly allocated into 4 groups. Multiple, single, forceps, …

Incidental Parathyroidectomy During Thyroid Surgery: Risk Factors, Incidence, And Outcomes, Bünyami̇ Özoğul, Müfi̇de Nuran Akçay, Abdullah Kisaoğlu, Sabri̇ Selçuk Atamanalp, Gürkan Öztürk, Bülent Aydinli

Turkish Journal of Medical Sciences

Incidental removal of the parathyroid glands is common in some cases. In this trial, we investigated the risk factors, incidence, and outcomes associated with incidental excision of the parathyroid glands during thyroid surgery. Materials and methods: The records of patients who had undergone thyroid surgery in our department between January 2006 and December 2011 were retrospectively evaluated. Results: A total of 801 patients were enrolled in the trial. The number of incidental parathyroidectomies was determined as 19 (2.3%). Statistical evaluation revealed that sex (P > 0.05) and type of surgical operation (P > 0.05) were not associated with a significant impact on …

Indoor Air Quality In Primary Schools In Keçiören, Ankara, Mustafa Alparslan Babayi̇ği̇t, Bi̇lal Bakir, Ömer Faruk Tekbaş, Recai̇ Oğur, Abdullah Kiliç, Serdar Ulus

Turkish Journal of Medical Sciences

To increase the awareness of environmental risk factors by determining the indoor air quality status of primary schools. Materials and methods: Indoor air quality parameters in 172 classrooms of 31 primary schools in Keçiören, Ankara, were examined for the purpose of assessing the levels of air pollutants (CO, CO_2, SO_2, NO_2, and formaldehyde) within primary schools. Results: Schools near heavy traffic had a statistically significant mean average of CO and SO_2 (P < 0.05). The classrooms that had more than 35 students had higher and statistically significant averages of CO_2, SO_2, NO_2, and formaldehyde compared to classrooms that had fewer than 35 students (P < 0.05). Of all classrooms, 29% had 100 CFU/100 mL and higher concentrations of microorganisms, which were not pathogens. Conclusion: Indoor air quality management should continually be maintained in primary schools for the prevention and control of acute and chronic diseases, particularly considering biological and chemical pollution.

Right-Sided Double-Lumen Tubes: Need For Design Improvement And Better Insertion Technique?, Jean S. Bussieres, Jérôme Lemieux, Jacques Somma

Turkish Journal of Medical Sciences

No abstract provided.

Neurobiological Mechanisms That Contribute To Stress-Related Cocaine Use, John R. Mantsch, Oliver Vranjkovic, Robert C. Twining, Paul J. Gasser, Jayme R. Mcreynolds, Jordan M. Blacktop

Biomedical Sciences Faculty Research and Publications

The ability of stressful life events to trigger drug use is particularly problematic for the management of cocaine addiction due to the unpredictable and often uncontrollable nature of stress. For this reason, understanding the neurobiological processes that contribute to stress-related drug use is important for the development of new and more effective treatment strategies aimed at minimizing the role of stress in the addiction cycle. In this review we discuss the neurocircuitry that has been implicated in stress-induced drug use with an emphasis on corticotropin releasing factor actions in the ventral tegmental area (VTA) and an important pathway from the …

Importance Of Bacillithiol In The Oxidative Stress Response Of Staphylococcus Aureus, Ana C. Posada, Stacey L. Kolar, Renata G. Dusi, Patrica Francois

Dartmouth Scholarship

In Staphylococcus aureus, the low-molecular-weight thiol called bacillithiol (BSH), together with cognate S-transferases, is believed to be the counterpart to the glutathione system of other organisms. To explore the physiological role of BSH in S. aureus, we constructed mutants with the deletion of bshA (sa1291), which encodes the glycosyltransferase that catalyzes the first step of BSH biosynthesis, and fosB (sa2124), which encodes a BSH-S-transferase that confers fosfomycin resistance, in several S. aureus strains, including clinical isolates. Mutation of fosB or bshA caused a 16- to 60-fold reduction in fosfomycin resistance in these S. aureus strains. High-pressure liquid chromatography analysis, which …

Parp Inhibition: A Method Of Treating And Preventing Certain Cancers, Chana Tropper

The Science Journal of the Lander College of Arts and Sciences

Breast cancer is one of the largest causes of cancer related deaths in women. Less than 5% of breast cancer cases are genetically inherited and most often develop after menopause. The BRCA gene mutation is a genetic inheritance which increases ones chances of developing breast cancer at a young age tenfold. Recent research has proposed a method of treatment in genetically inherited breast cancers by taking advantage of the impaired DNA repair pathway caused by the BRCA mutation. The combination of a BRCA mutation, which leads to deficient double strand DNA repair, and PARP inhibition, which leads to deficient single …

Novel Roles For Actin In Mitochondrial Fission, Anna L. Hatch, Pinar S. Gurel, Henry N. Higgs

Dartmouth Scholarship

Mitochondrial dynamics, including fusion, fission and translocation, are crucial to cellular homeostasis, with roles in cellular polarity, stress response and apoptosis. Mitochondrial fission has received particular attention, owing to links with several neurodegenerative diseases. A central player in fission is the cytoplasmic dynamin-related GTPase Drp1, which oligomerizes at the fission site and hydrolyzes GTP to drive membrane ingression. Drp1 recruitment to the outer mitochondrial membrane (OMM) is a key regulatory event, which appears to require a pre-constriction step in which the endoplasmic reticulum (ER) and mitochondrion interact extensively, a process termed ERMD (ER-associated mitochondrial division). It is unclear how ER-mitochondrial …

Caspase-12 And Rheumatoid Arthritis In African-Americans, Laura Marshall, Mohammad Obaidullah, Trista Fuchs, Naomi S. Fineberg, Garland Brinkley, Ted R. Mikuls, Evan Hermel

Faculty Publications & Research of the TUC College of Osteopathic Medicine

CASPASE-12 (CASP12) has a downregulatory function during infection and thus may protect against inflammatory disease. We investigated the distribution of CASP12 alleles (#rs497116) in African-Americans (AA) with rheumatoid arthritis (RA). CASP12 alleles were genotyped in 953 RA patients and 342 controls. Statistical analyses comparing genotype groups were performed using Kruskal–Wallis non-parametric ANOVA with Mann–Whitney U tests and chi-square tests. There was no significant difference in the overall distribution of CASP12 genotypes within AA with RA, but CASP12 homozygous patients had lower baseline joint-narrowing scores. CASP12 homozygosity appears to be a subtle protective factor for some aspects of RA in AA …

Synthesis And Evaluation Of C-Src Kinase Inhibitory Activity Of Pyridin-2(1h)-One Derivatives, Karam Chand, Suchita Prasad, Rakesh Tiwari, Amir Nasrolahi Shirazi, Sumit Kumar, Keykavous Parang, Sunil K. Sharma

Pharmacy Faculty Articles and Research

Src kinase, a prototype member of the Src family of kinases (SFKs), is over-expressed in various human tumors, and has become a target for anticancer drug design. In this perspective, a series of eighteen 2-pyridone derivatives were synthesized and evaluated for their c-Src kinase inhibitory activity. Among them, eight compounds exhibited c-Src kinase inhibitory activity with IC50 value of less than 25 mu M. Compound 1-[2-(dimethylamino)ethyl]-5-(2-hydroxy-4-methoxybenzoyl)pyridin-2(1H)-one (36) exhibited the highest c-Src kinase inhibition with an IC50 value of 12.5 mu M. Furthermore, the kinase inhibitory activity of compound 36 was studied against EGFR, MAPK and PDK, however no significant activity …

Three‐Dimensional Brain Mri For Dbs Patients Within Ultra‐Low Radiofrequency Power Limits, Subhendra N. Sarkar, Efstathios Papavassiliou, David Hackney, David Alsop, Ananth Madhuranthakam, Ludy Shih, Reed Busse, Susan Laruche, Rafeeque Bhadelia

Publications and Research

Background: For patients with deep brain stimulators (DBS), local absorbed radiofrequency (RF) power is unknown and is much higher than what the system estimates. We developed a comprehensive, highquality brain magnetic resonance imaging (MRI) protocol for DBS patients utilizing three-dimensional (3D) magnetic resonance sequences at very low RF power. Methods: Six patients with DBS were imaged (10 sessions) using a transmit/receive head coil at 1.5 Tesla with modified 3D sequences within ultra-low specific absorption rate (SAR) limits (0.1 W/kg) using T2, fast fluid-attenuated inversion recovery (FLAIR) and T1- weighted image contrast. Tissue signal and tissue contrast from the low-SAR images …

An Anemia Of Alzheimer's Disease, N G. Faux, A Rembach, J Wiley, K A. Ellis, D Ames, C J. Fowler, Ralph N. Martins, K K. Pertile, R L. Rumble, B Trounson, C L. Masters, A I. Bush

Research outputs 2014 to 2021

Lower hemoglobin is associated with cognitive impairment and Alzheimer's disease (AD). Since brain iron homeostasis is perturbed in AD, we investigated whether this is peripherally reflected in the hematological and related blood chemistry values from the Australian Imaging Biomarker and Lifestyle (AIBL) study (a community-based, cross-sectional cohort comprising 768 healthy controls (HC), 133 participants with mild cognitive impairment (MCI) and 211 participants with AD). We found that individuals with AD had significantly lower hemoglobin, mean cell hemoglobin concentrations, packed cell volume and higher erythrocyte sedimentation rates (adjusted for age, gender, APOE-ε4 and site). In AD, plasma iron, transferrin, transferrin saturation …

The Reliability Of An Adolescent Dietary Pattern Identified Using Reduced-Rank Regression: Comparison Of A Ffq And 3 D Food Record, Geeta Appannah, Gerda K. Pot, Therese A. O'Sullivan, Wendy H. Oddy, Susan A. Jebb, Gina L. Ambrosini

Research outputs 2014 to 2021

Despite the increasing use of dietary patterns (DP) to study diet and health outcomes, relatively few studies have examined the reliability of DP using different dietary assessment methods. Reduced-rank regression (RRR) is an emerging statistical method that incorporates a priori information to characterise DP related to specific outcomes of interest. The aim of the present study was to compare DP identified using the RRR method in a FFQ with those in a 3 d food record (FR). Participants were 783 adolescents from the Western Australian Pregnancy (Raine) Cohort Study who completed both a FFQ and FR at 14 years of …

Blast-Induced Tinnitus: A Combined Behavioral, Memri, And Electrophysiology Study, Jessica Pengyun Ouyang

Wayne State University Dissertations

ABSTRACT

BLAST-INDUCED TINNITUS: A COMBINED BEHAVIORAL, MEMRE, AND ELECTROPHYSIOLOGY STUDY

by

JESSICA OUYANG

May 2014 Advisor: Drs. Steve Cala & Jinsheng Zhang

Major: Physiology

Degree: Doctor of Philosophy

Tinnitus and hearing loss are the frequent auditory-related co-morbidities of blast trauma. The etiology of blast-induced tinnitus is also muddled by brain mechanisms associated with emotional and cognitive problems such as anxiety, memory loss, and depression. We set out to develop a realistic and ecologically valid model to address changes of cognitive status and psychological state that are associated with blast- induced tinnitus. In this study, 19 adult rats were randomly divided …

Inhibition Of Rac1 Gtpase Sensitizes Pancreatic Cancer Cells To Γ-Irradiation, Y Yan, Ashley L. Hein, Asserewou Etekpo, Katrina M. Burchett, Chi Lin, Charles A. Enke, Surinder K. Batra, Kenneth Cowan, Michel M. Ouellette

Journal Articles: Biochemistry & Molecular Biology

Radiation therapy is a staple treatment for pancreatic cancer. However, owing to the intrinsic radioresistance of pancreatic cancer cells, radiation therapy often fails to increase survival of pancreatic cancer patients. Radiation impedes cancer cells by inducing DNA damage, which can activate cell cycle checkpoints. Normal cells possess both a G1 and G2 checkpoint. However, cancer cells are often defective in G1 checkpoint due to mutations/alterations in key regulators of this checkpoint. Accordingly, our results show that normal pancreatic ductal cells respond to ionizing radiation (IR) with activation of both checkpoints whereas pancreatic cancer cells respond to IR with G2/M arrest …

A Pilot Experimental Study Of A Catheter To Facilitate Treatment For Penetrating Cardiac Injury, Mahmut Tokur, Mehmet Ergi̇n, İbrahi̇m Can Kürkçüoğlu, Zerri̇n Defne Dündar

Turkish Journal of Medical Sciences

Penetrating heart injuries result in high mortality. We designed a new catheter to facilitate the treatment of penetrating cardiac injuries and provide more effective initial bleeding control and fluid replacement. Materials and methods: The cardiac injury model was applied to 8 female 1-year-old Sus domesticus pigs. Subjects were grouped according to whether a Foley catheter or a newly designed catheter was placed into the heart through cardiac lacerations. Changes in systolic blood pressures, mortality, and problems encountered during surgery and other intraoperative findings were recorded. Results: There were higher mean blood pressure measurements in the newly designed catheter group during …

Regulation Of Glucose Homeostasis By The Phlpp1 Phosphatase, Kara L. Larson

Theses and Dissertations--Molecular and Cellular Biochemistry

Type 2 diabetes mellitus is a metabolic disease that affects one in ten people in the United States. It is caused by a combination of genetics and lifestyle factors. Disease progression begins with insulin resistance in peripheral tissues followed by pancreatic beta-cell failure. The mechanisms behind disease progression are not completely understood. PH domain leucine rich repeat protein phosphatase 1 (PHLPP1) is a known regulator of Akt and other members of the AGC kinase family. Akt has been established to play a role in numerous metabolic signaling pathways, including insulin action. It is hypothesized that as a regulator of Akt, …

Altered Entrainment To The Day/Night Cycle Attenuates The Daily Rise In Circulating Corticosterone In The Mouse, Patricia J. Sollars, Michael J. Weiser, Andrea E. Kudwa, Jayne R. Bramley, Malcolm D. Ogilvie, Robert L. Spencer, Robert J. Handa, Gary E. Pickard

School of Veterinary and Biomedical Sciences: Faculty Publications

The suprachiasmatic nucleus (SCN) is a circadian oscillator entrained to the day/night cycle via input from the retina. Serotonin (5-HT) afferents to the SCN modulate retinal signals via activation of 5-HT_1B receptors, decreasing responsiveness to light. Consequently, 5-HT_1B receptor knockout (KO) mice entrain to the day/night cycle with delayed activity onsets. Since circulating corticosterone levels exhibit a robust daily rhythm peaking around activity onset, we asked whether delayed entrainment of activity onsets affects rhythmic corticosterone secretion. Wheel-running activity and plasma corticosterone were monitored in mice housed under several different lighting regimens. Both duration of the light:dark cycle (T …