Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 75

Full-Text Articles in Life Sciences

Genetic And Acute Cpeb1 Depletion Ameliorate Fragile X Pathophysiology, Tsuyoshi Udagawa, Natalie Farny, Mira Jakovcevski, Hanoch Kaphzan, Juan Alarcon, Shobha Anilkumar, Maria Ivshina, Jessica Hurt, Kentaro Nagaoka, Vijayalaxmi Nalavadi, Lori Lorenz, Gary Bassell, Schahram Akbarian, Sumantra Chattarji, Eric Klann, Joel Richter Dec 2015

Genetic And Acute Cpeb1 Depletion Ameliorate Fragile X Pathophysiology, Tsuyoshi Udagawa, Natalie Farny, Mira Jakovcevski, Hanoch Kaphzan, Juan Alarcon, Shobha Anilkumar, Maria Ivshina, Jessica Hurt, Kentaro Nagaoka, Vijayalaxmi Nalavadi, Lori Lorenz, Gary Bassell, Schahram Akbarian, Sumantra Chattarji, Eric Klann, Joel Richter

Natalie G. Farny

Fragile X syndrome (FXS), the most common cause of inherited mental retardation and autism, is caused by transcriptional silencing of FMR1, which encodes the translational repressor fragile X mental retardation protein (FMRP). FMRP and cytoplasmic polyadenylation element-binding protein (CPEB), an activator of translation, are present in neuronal dendrites, are predicted to bind many of the same mRNAs and may mediate a translational homeostasis that, when imbalanced, results in FXS. Consistent with this possibility, Fmr1(-/y); Cpeb1(-/-) double-knockout mice displayed amelioration of biochemical, morphological, electrophysiological and behavioral phenotypes associated with FXS. Acute depletion of CPEB1 in the hippocampus of adult Fmr1(-/y) mice …


Acute Effects Of Whole-Body Vibration On Lower Extremity Muscle Performance In Persons With Multiple Sclerosis, Kurt Jackson, Harold Merriman, Paul Vanderburgh, C. Brahler Dec 2015

Acute Effects Of Whole-Body Vibration On Lower Extremity Muscle Performance In Persons With Multiple Sclerosis, Kurt Jackson, Harold Merriman, Paul Vanderburgh, C. Brahler

C. Jayne Brahler

Background and Purpose: Whole-body vibration (WBV) is a relatively new form of exercise training that may influence muscle performance. This study investigated the acute effects of high (26 Hz) and low (2 Hz) frequency WBV on isometric muscle torque of the quadriceps and hamstrings in persons with multiple sclerosis (MS).

Participants and Method: Fifteen individuals (mean age = 54.6 years, SD = 9.6) with MS and Expanded Disability Status Scale (EDSS) scores ranging from 0-6.5 (mean = 4.2, SD = 2.3) participated in this randomized cross-over study. Following baseline measures of isometric quadricep and hamstring torque, subjects were exposed to …


Substrate Rigidity Regulates The Formation And Maintenance Of Tissues, Wei-Hui Guo, Margo Frey, Nancy Burnham, Yu-Li Wang Dec 2015

Substrate Rigidity Regulates The Formation And Maintenance Of Tissues, Wei-Hui Guo, Margo Frey, Nancy Burnham, Yu-Li Wang

Nancy A. Burnham

The ability of cells to form tissues represents one of the most fundamental issues in biology. However, it is unclear what triggers cells to adhere to one another in tissues and to migrate once a piece of tissue is planted on culture surfaces. Using substrates of identical chemical composition but different flexibility, we show that this process is controlled by substrate rigidity: on stiff substrates, cells migrate away from one another and spread on surfaces, whereas on soft substrates they merge to form tissue-like structures. Similar behavior was observed not only with fibroblastic and epithelial cell lines but also explants …


Characterizing The Performance And Behaviors Of Runners Using Twitter, Qian He, Emmanuel Agu, Diane Strong, Bengisu Tulu, Peder Pedersen Dec 2015

Characterizing The Performance And Behaviors Of Runners Using Twitter, Qian He, Emmanuel Agu, Diane Strong, Bengisu Tulu, Peder Pedersen

Emmanuel O. Agu

Running is a popular physical activity that improves physical and mental wellbeing. Unfortunately, up-to- date information about runners’ performance and psychological wellbeing is limited. Many questions remain unanswered, such as how far and how fast runners typically run, their preferred running times and frequencies, how long new runners persist before dropping out, and what factors cause runners to quit. Without hard data, establishing patterns of runner behavior and mitigating the challenges they face are difficult. Collecting data manually from large numbers of runners for research studies is costly and time consuming. Emerging Social Networking Services (SNS) and fitness tracking devices …


Task-Specific And General Cognitive Effects In Chiari Malformation Type I, Philip Allen, James Houston, Joshua Pollock, Christopher Buzzelli, Xuan Li, A. Harrington, Bryn Martin, Francis Loth, Mei-Ching Lien, Jahangir Maleki, Mark Luciano Oct 2015

Task-Specific And General Cognitive Effects In Chiari Malformation Type I, Philip Allen, James Houston, Joshua Pollock, Christopher Buzzelli, Xuan Li, A. Harrington, Bryn Martin, Francis Loth, Mei-Ching Lien, Jahangir Maleki, Mark Luciano

Philip A Allen

Our objective was to use episodic memory and executive function tests to determine whether or not Chiari Malformation Type I (CM) patients experience cognitive dysfunction.


Control Of Stem Cell Self-Renewal And Differentiation By The Heterochronic Genes And The Cellular Asymmetry Machinery In Caenorhabditis Elegans, Omid F. Harandi, Victor Ambros Oct 2015

Control Of Stem Cell Self-Renewal And Differentiation By The Heterochronic Genes And The Cellular Asymmetry Machinery In Caenorhabditis Elegans, Omid F. Harandi, Victor Ambros

Victor R. Ambros

Transitions between asymmetric (self-renewing) and symmetric (proliferative) cell divisions are robustly regulated in the context of normal development and tissue homeostasis. To genetically assess the regulation of these transitions, we used the postembryonic epithelial stem (seam) cell lineages of Caenorhabditis elegans. In these lineages, the timing of these transitions is regulated by the evolutionarily conserved heterochronic pathway, whereas cell division asymmetry is conferred by a pathway consisting of Wnt (Wingless) pathway components, including posterior pharynx defect (POP-1)/TCF, APC related/adenomatosis polyposis coli (APR-1)/APC, and LIT-1/NLK (loss of intestine/Nemo-like kinase). Here we explore the genetic regulatory mechanisms underlying stage-specific transitions between self-renewing …


Mir-14 Regulates Autophagy During Developmental Cell Death By Targeting Ip3-Kinase 2, Charles Nelson, Victor Ambros, Eric Baehrecke Oct 2015

Mir-14 Regulates Autophagy During Developmental Cell Death By Targeting Ip3-Kinase 2, Charles Nelson, Victor Ambros, Eric Baehrecke

Victor R. Ambros

Macroautophagy (autophagy) is a lysosome-dependent degradation process that has been implicated in age-associated diseases. Autophagy is involved in both cell survival and cell death, but little is known about the mechanisms that distinguish its use during these distinct cell fates. Here, we identify the microRNA miR-14 as being both necessary and sufficient for autophagy during developmentally regulated cell death in Drosophila. Loss of miR-14 prevented induction of autophagy during salivary gland cell death, but had no effect on starvation-induced autophagy in the fat body. Moreover, misexpression of miR-14 was sufficient to prematurely induce autophagy in salivary glands, but not in …


Timing Influence Of Carbohydrate-Protein Ingestion On Muscle Soreness And Next-Day Running Performance, Beau Greer, Anna Greer, Brett Jones Jul 2015

Timing Influence Of Carbohydrate-Protein Ingestion On Muscle Soreness And Next-Day Running Performance, Beau Greer, Anna Greer, Brett Jones

Anna E. Greer

The present study investigates timing effects of a carbohydrate-protein (CHO-PROT) beverage on indicators of muscle damage and next day running performance. Nine trained subjects completed three trials of a 30 min downhill run, followed by a 1.5 mile treadmill running time trial 24 hours later in a blinded, crossover design. Either a CHO-PROT or non-caloric placebo beverage was given 30 min and 5 min prior to, at the 15 min mark during, immediately after, and 30 min after the downhill running protocol. In the first treatment (T1), a total of 360 kilocalories was given 30 min and 5 min prior …


Drug-Resistant Hiv-1 Protease Regains Functional Dynamics Through Cleavage Site Coevolution, Nevra Ozer, Aysegul Ozen, Celia Schiffer, Turkan Haliloglu May 2015

Drug-Resistant Hiv-1 Protease Regains Functional Dynamics Through Cleavage Site Coevolution, Nevra Ozer, Aysegul Ozen, Celia Schiffer, Turkan Haliloglu

Celia A. Schiffer

Drug resistance is caused by mutations that change the balance of recognition favoring substrate cleavage over inhibitor binding. Here, a structural dynamics perspective of the regained wild-type functioning in mutant HIV-1 proteases with coevolution of the natural substrates is provided. The collective dynamics of mutant structures of the protease bound to p1-p6 and NC-p1 substrates are assessed using the Anisotropic Network Model (ANM). The drug-induced protease mutations perturb the mechanistically crucial hinge axes that involve key sites for substrate binding and dimerization and mainly coordinate the intrinsic dynamics. Yet with substrate coevolution, while the wild-type dynamic behavior is restored in …


Validity Of Borg Ratings Of Perceived Exertion During Active Video Game Play, Brandon Pollock, Jacob Barkley, Nick Potenzini, Renee Desalvo, Stacey Buser, Ronald Otterstetter, Judith Juvancic-Heltzel May 2015

Validity Of Borg Ratings Of Perceived Exertion During Active Video Game Play, Brandon Pollock, Jacob Barkley, Nick Potenzini, Renee Desalvo, Stacey Buser, Ronald Otterstetter, Judith Juvancic-Heltzel

Jacob E Barkley

International Journal of Exercise Science 6(2) : 164-170, 2013. During physically interactive video game play (e.g., Nintendo Wii), users are exposed to potential distracters (e.g., video, music), which may decrease their ratings of perceived exertion (RPE) throughout game play. The purpose of this investigation was to determine the association between RPE scores and heart rate while playing the Nintendo Wii. Healthy adults (N = 13, 53.5 ± 5.4 years old) participated in two exercise sessions using the Nintendo Wii Fit Plus. During each session participants played a five-minute warm-up game (Basic Run), two separate Wii Fit Plus games (Yoga, Strength …


The Physiologic And Behavioral Implications Of Playing Active And Sedentary Video Games In A Seated And Standing Position, Gabriel Sanders, Michael Rebold, Corey Peacock, Megan Williamson, Antonio Santo, Jacob Barkley May 2015

The Physiologic And Behavioral Implications Of Playing Active And Sedentary Video Games In A Seated And Standing Position, Gabriel Sanders, Michael Rebold, Corey Peacock, Megan Williamson, Antonio Santo, Jacob Barkley

Jacob E Barkley

International Journal of Exercise Science 7(3) : 194-201, 2014. Previous studies have assessed physiologic response while playing video games per manufacturer instructions with participants standing during active video game play and seated during sedentary game play. It is not known whether an assigned seated or standing position affects positional preference and oxygen consumption (VO2) while gaming. The purpose of the study was to assess VO2 and preference of playing active and sedentary video games in a seated and standing position. VO2 was assessed in 25 participants during four, 20-minute conditions; resting, PlayStation 2 Madden NFL Football 2011, Nintendo Wii-Sports Boxing …


Physiologic Responses, Liking And Motivation For Playing The Same Video Game On An Active Versus A Traditional, Non-Active Gaming System., Gabriel Sanders, Antonia Santo, Corey Peacock, Kyle-Patrick Von Carlowitz, Megan Williamson, Jacob Barkley May 2015

Physiologic Responses, Liking And Motivation For Playing The Same Video Game On An Active Versus A Traditional, Non-Active Gaming System., Gabriel Sanders, Antonia Santo, Corey Peacock, Kyle-Patrick Von Carlowitz, Megan Williamson, Jacob Barkley

Jacob E Barkley

Int J Exerc Sci 5(2) : 160-169, 2012. Evidence suggests that individuals playing certain video games on the Nintendo Wii® (Wii) exhibit increased energy expenditure versus traditional video games, although little research examines non-Wii Sports/Fit games. The purpose of this study is to assess physiologic responses, liking, and the relative reinforcing value (RRV) of a popular, non-Wii sports video game for the Wii relative to the same game played on a traditional, non-active system. Twenty-four college-aged students participated. Heart rate and oxygen consumption (O2) was assessed during rest and when playing the following games: Madden NFL 2011® for Playstation 2 …


Task-Specific And General Cognitive Effects In Chiari Malformation Type I, Philip Allen, James Houston, Joshua Pollock, Christopher Buzzelli, Xuan Li, A. Harrington, Bryn Martin, Francis Loth, Mei-Ching Lien, Jahangir Maleki, Mark Luciano Apr 2015

Task-Specific And General Cognitive Effects In Chiari Malformation Type I, Philip Allen, James Houston, Joshua Pollock, Christopher Buzzelli, Xuan Li, A. Harrington, Bryn Martin, Francis Loth, Mei-Ching Lien, Jahangir Maleki, Mark Luciano

Dr. Bryn Martin

Our objective was to use episodic memory and executive function tests to determine whether or not Chiari Malformation Type I (CM) patients experience cognitive dysfunction.


Community Based Nutritition Education: A Model For Raising Awareness Of Childhood Obesity, Selina Ahmed Mar 2015

Community Based Nutritition Education: A Model For Raising Awareness Of Childhood Obesity, Selina Ahmed

Selina M Ahmed PhD

Background: Since 2003, Texas Southern University has coordinated conferences to educate Houston’s Third Ward community about strategies to combat childhood obesity. Presenters included faculty and students as speakers and activity coordinators. Participants indicated that these conferences are helpful in increasing awareness of health problems and the availability of community health resources. Purpose: To address the high rate of childhood obesity in Houston’s Third Ward and its costs in terms of health and long-term productivity on that community, faculty at Texas Southern University (TSU) coordinated annual conferences to educate community members about strategies to combat childhood obesity. Methods: Seven conferences intended …


Body Mass Bias In Exercise Physiology, Paul Vanderburgh Mar 2015

Body Mass Bias In Exercise Physiology, Paul Vanderburgh

Paul M. Vanderburgh

In certain physically demanding occupations, especially the military, body mass bias has substantive implications. Work physiologists have determined that despite body mass bias in the common military physical fitness tests, the larger service members were often better performers of the physically demanding occupational tasks (Bilzon et al., 2002; Lyons et al., 2005; Rayson et al., 2000). That is, they could carry more, more easily evacuate casualties, and better engage in heavy materiel handling. Yet, the smaller personnel were achieving better scores on the physical fitness tests, the results of which have significant promotion and advancement implications (Vanderburgh & Mahar , …


Evolution Of The Influenza A Virus Genome During Development Of Oseltamivir Resistance In Vitro, Nicholas Renzette, Daniel Caffrey, Konstantin Zeldovich, Ping Liu, Glen Gallagher, Daniel Aiello, Alyssa Porter, Evelyn Kurt-Jones, Daniel Bolon, Yu-Ping Poh, Jeffrey Jensen, Celia Schiffer, Timothy Kowalik, Robert Finberg, Jennifer Wang Mar 2015

Evolution Of The Influenza A Virus Genome During Development Of Oseltamivir Resistance In Vitro, Nicholas Renzette, Daniel Caffrey, Konstantin Zeldovich, Ping Liu, Glen Gallagher, Daniel Aiello, Alyssa Porter, Evelyn Kurt-Jones, Daniel Bolon, Yu-Ping Poh, Jeffrey Jensen, Celia Schiffer, Timothy Kowalik, Robert Finberg, Jennifer Wang

Glen R. Gallagher

Influenza A virus (IAV) is a major cause of morbidity and mortality throughout the world. Current antiviral therapies include oseltamivir, a neuraminidase inhibitor that prevents the release of nascent viral particles from infected cells. However, the IAV genome can evolve rapidly, and oseltamivir resistance mutations have been detected in numerous clinical samples. Using an in vitro evolution platform and whole-genome population sequencing, we investigated the population genomics of IAV during the development of oseltamivir resistance. Strain A/Brisbane/59/2007 (H1N1) was grown in Madin-Darby canine kidney cells with or without escalating concentrations of oseltamivir over serial passages. Following drug treatment, the H274Y …


Sam: A Tool For Measurement Of Moderate To Vigorous Physical Activity (Mvpa) In School Physical Education, Kampol Surapiboonchai, Steven Furney, Robert Reardon, James Eldridge, Tinker Murray Mar 2015

Sam: A Tool For Measurement Of Moderate To Vigorous Physical Activity (Mvpa) In School Physical Education, Kampol Surapiboonchai, Steven Furney, Robert Reardon, James Eldridge, Tinker Murray

James Eldridge

Int J Exerc Sci 5(2) : 127-135, 2012. Observational methods have been a primary methodology used by physical educators for assessing teacher and student behaviors in school physical education (PE) classes for over 30 years. Observational instruments traditionally used in PE are economical, but are time intensive and complicated. Recently national PE recommendations have been promoted to encourage practitioners to achieve ≥ 50% of PE class in moderate to vigorous physical activity (MVPA). The purpose of this preliminary study was to develop, validate, and test the reliability of the Simple Activity Measurement (SAM) instrument for assessing MVPA during school PE …


The Effects Of Vascular Occlusion Training On Respiratory Exchange Ratio And Energy Expenditure When Coupled With Cardiovascular Training, Justin Sprick, Richard Lloyd, James Eldridge Mar 2015

The Effects Of Vascular Occlusion Training On Respiratory Exchange Ratio And Energy Expenditure When Coupled With Cardiovascular Training, Justin Sprick, Richard Lloyd, James Eldridge

James Eldridge

International Journal of Exercise Science 8(1) : 57-64, 2015. Vascular occlusion training is a novel training modality that has received considerable attention in the exercise science literature. The current study is the first of its kind to look at the effects of vascular occlusion training on substrate utilization when combined with aerobic training. This study examined the effects of pairing a vascular occlusion training protocol with a bout of submaximal aerobic exercise on energy expenditure (EE) and fuel use during exercise. Subjects performed a 20 minute bout of sub-maximal aerobic exercise either exclusively, or after performing a body weight squat …


Fitnessgram® Friday: A Middle School Physical Activity And Fitness Intervention, Tinker Murray, James Eldridge, Pete Silvius, Erik Silvius, William Squires Mar 2015

Fitnessgram® Friday: A Middle School Physical Activity And Fitness Intervention, Tinker Murray, James Eldridge, Pete Silvius, Erik Silvius, William Squires

James Eldridge

Texas Senate Bill 530 (2007) mandated fitness assessment as part of the annual K-8 Physical Education (PE) curricula, yet no studies have reported interventions designed to improve and quantify individual student passing rates or individual school performance. Students (Total 2008-2010 N=1484; 729 females, 755 males; mean age = 11.85 y; mean BMI = 22.69 or > 90%-tile, overweight) were evaluated on individual FITNESSGRAM® performances in a cross-sectional analysis of 6th graders comparing baseline scores (year 1) with outcomes of a physical activity intervention in years 2 and 3. Students participated in regular PE classes (including campus wellness center activities) with a …


Supervillin Binds The Rac/Rho-Gef Trio And Increases Trio-Mediated Rac1 Activation, Kyonghee Son, Tara Smith, Elizabeth Luna Mar 2015

Supervillin Binds The Rac/Rho-Gef Trio And Increases Trio-Mediated Rac1 Activation, Kyonghee Son, Tara Smith, Elizabeth Luna

Elizabeth J. Luna

We investigated cross-talk between the membrane-associated, myosin II-regulatory protein supervillin and the actin-regulatory small GTPases Rac1, RhoA, and Cdc42. Supervillin knockdown reduced Rac1-GTP loading, but not the GTP loading of RhoA or Cdc42, in HeLa cells with normal levels of the Rac1-activating protein Trio. No reduction in Rac1-GTP loading was observed when supervillin levels were reduced in Trio-depleted cells. Conversely, overexpression of supervillin isoform 1 (SV1) or, especially, isoform 4 (SV4) increased Rac1 activation. Inhibition of the Trio-mediated Rac1 guanine nucleotide exchange (GEF) activity with ITX3 partially blocked the SV4-mediated increase in Rac1-GTP. Both SV4 and SV1 co-localized with Trio …


Gamma-Sarcoglycan Is Required For The Response Of Archvillin To Mechanical Stimulation In Skeletal Muscle, Janelle Spinazzola, Tara Smith, Min Liu, Elizabeth Luna, Elisabeth Barton Mar 2015

Gamma-Sarcoglycan Is Required For The Response Of Archvillin To Mechanical Stimulation In Skeletal Muscle, Janelle Spinazzola, Tara Smith, Min Liu, Elizabeth Luna, Elisabeth Barton

Elizabeth J. Luna

Loss of gamma-sarcoglycan (gamma-SG) induces muscle degeneration and signaling defects in response to mechanical load, and its absence is common to both Duchenne and limb girdle muscular dystrophies. Growing evidence suggests that aberrant signaling contributes to the disease pathology; however, the mechanisms of gamma-SG-mediated mechanical signaling are poorly understood. To uncover gamma-SG signaling pathway components, we performed yeast two-hybrid screens and identified the muscle-specific protein archvillin as a gamma-SG and dystrophin interacting protein. Archvillin protein and message levels were significantly upregulated at the sarcolemma of murine gamma-SG-null (gsg-/-) muscle but delocalized in dystrophin-deficient mdx muscle. Similar elevation of archvillin protein …


Sex And Size Interaction And Standard Metabolic Rate Of Paedomorphic Ambystoma Talpoideum: Size Does Matter, Travis Ryan, William Hopkins Feb 2015

Sex And Size Interaction And Standard Metabolic Rate Of Paedomorphic Ambystoma Talpoideum: Size Does Matter, Travis Ryan, William Hopkins

Travis J. Ryan

We measured the standard metabolic rate of paedomorphic Mole Salamanders (Ambystoma talpoideum) from South Carolina. Despite an absence of body size differences between females and males, analysis of covariance demonstrated metabolic rates (mL O2/h) were significantly influenced by an interaction between sex and body size. The interaction appeared as a result of changes in the size-metabolism relationship in males (a steeper slope in the size-metabolism regression in small males as compared to large males), whereas the relationship remained constant in females, regardless of size. We hypothesize that the observed differences are attributable to differences in reproductive physiology between the sexes. …


Differential Muscle Hypertrophy Is Associated With Satellite Cell Numbers And Akt Pathway Activation Following Activin Type Iib Receptor Inhibition In Mtm1 P.R69c Mice, Michael Lawlor, Marissa Viola, Hui Meng, Rachel Edelstein, Fujun Liu, Ke Yan, Elizabeth Luna, Alexandra Lerch-Gaggl, Raymond Hoffmann, Christopher Pierson, Anna Buj-Bello, Jennifer Lachey, Scott Pearsall, Lin Yang, Cecilia Hillard, Alan Beggs Oct 2014

Differential Muscle Hypertrophy Is Associated With Satellite Cell Numbers And Akt Pathway Activation Following Activin Type Iib Receptor Inhibition In Mtm1 P.R69c Mice, Michael Lawlor, Marissa Viola, Hui Meng, Rachel Edelstein, Fujun Liu, Ke Yan, Elizabeth Luna, Alexandra Lerch-Gaggl, Raymond Hoffmann, Christopher Pierson, Anna Buj-Bello, Jennifer Lachey, Scott Pearsall, Lin Yang, Cecilia Hillard, Alan Beggs

Elizabeth J. Luna

X-linked myotubular myopathy is a congenital myopathy caused by deficiency of myotubularin. Patients often present with severe perinatal weakness, requiring mechanical ventilation to prevent death from respiratory failure. We recently reported that an activin receptor type IIB inhibitor produced hypertrophy of type 2b myofibers and modest increases of strength and life span in the severely myopathic Mtm1δ4 mouse model of X-linked myotubular myopathy. We have now performed a similar study in the less severely symptomatic Mtm1 p.R69C mouse in hopes of finding greater treatment efficacy. Activin receptor type IIB inhibitor treatment of Mtm1 p.R69C animals produced behavioral and histological evidence …


Measurement Of Mullerian Inhibiting Substance Facilitates Management Of Boys With Microphallus And Cryptorchidism, Madhusmita Misra, David Maclaughlin, Patricia Donahoe, Mary Lee Sep 2014

Measurement Of Mullerian Inhibiting Substance Facilitates Management Of Boys With Microphallus And Cryptorchidism, Madhusmita Misra, David Maclaughlin, Patricia Donahoe, Mary Lee

Mary M. Lee

Mullerian inhibiting substance (MIS) is a gonadal hormone expressed in a sexually dimorphic pattern. In males, serum MIS reflects Sertoli cell function and provides an estimate of seminiferous tubular integrity. We examined the role of MIS determination in the evaluation of boys with microphallus (n = 62) and/or cryptorchidism (n = 156). MIS was normal in 69.2% of boys with isolated microphallus compared with 38.1% of boys with microphallus and coexisting cryptorchidism (P < 0.05). In the cryptorchid group, MIS was normal in 46.8%, low in 24.4%, and absent in 28.8%. Normal values for age were associated with testicular tissue, whereas …


Augmented Growth Hormone (Gh) Secretory Burst Frequency And Amplitude Mediate Enhanced Gh Secretion During A Two-Day Fast In Normal Men, Mark Hartman, Johannes Veldhuis, Michael Johnson, Mary Lee, K. Alberti, Eugene Samojlik, Michael Thorner Sep 2014

Augmented Growth Hormone (Gh) Secretory Burst Frequency And Amplitude Mediate Enhanced Gh Secretion During A Two-Day Fast In Normal Men, Mark Hartman, Johannes Veldhuis, Michael Johnson, Mary Lee, K. Alberti, Eugene Samojlik, Michael Thorner

Mary M. Lee

Serum GH concentrations are increased in fasted or malnourished human subjects. We investigated the dynamic mechanisms underlying this phenomenon in nine normal men by analyzing serum GH concentrations measured in blood obtained at 5-min intervals over 24 h on a control (fed) day and on the second day of a fast with a multiple-parameter deconvolution method to simultaneously resolve endogenous GH secretory and clearance rates. Two days of fasting induced a 5-fold increase in the 24-h endogenous GH production rate [78 +/- 12 vs. 371 +/- 57 micrograms/Lv (Lv, liter of distribution volume) or 0.24 +/- 0.038 vs. 1.1 +/- …


Male Pubertal Development: Are Endocrine-Disrupting Compounds Shifting The Norms, William Zawatski, Mary Lee Sep 2014

Male Pubertal Development: Are Endocrine-Disrupting Compounds Shifting The Norms, William Zawatski, Mary Lee

Mary M. Lee

Endocrine-disrupting compounds (EDCs) are synthetic or natural compounds that interfere with endogenous endocrine action. The frequent use of chemicals with endocrine active properties in household products and contamination of soil, water, and food sources by persistent chemical pollutants result in ubiquitous exposures. Wildlife observations and animal toxicological studies reveal adverse effects of EDCs on reproductive health. In humans, a growing number of epidemiological studies report an association with altered pubertal timing and progression. While these data are primarily reported in females, this review will focus on the small number of studies performed in males that report an association of polychlorinated …


Developmental Expression Of A Candidate Mullerian Inhibiting Substance Type Ii Receptor, Jose Teixeira, Wei He, Paresh Shah, Nobuyuki Morikawa, Mary Lee, Elizabeth Catlin, Peter Hudson, John Wing, David Maclaughlin, Patricia Donahoe Sep 2014

Developmental Expression Of A Candidate Mullerian Inhibiting Substance Type Ii Receptor, Jose Teixeira, Wei He, Paresh Shah, Nobuyuki Morikawa, Mary Lee, Elizabeth Catlin, Peter Hudson, John Wing, David Maclaughlin, Patricia Donahoe

Mary M. Lee

We have isolated a candidate Mullerian inhibiting substance (MIS) type II receptor complementary DNA from an embryonic rat urogenital ridge library and have studied its binding to MIS, its developmental pattern of expression and tissue distribution. By in situ hybridization with a full-length riboprobe, the receptor is expressed in the mesenchymal cells surrounding the Mullerian duct at embryonic days 14, 15, and 16 and in tubular and follicular structures of the rat fetal gonads. Expression of the messenger RNA was also seen in the granules cells and seminiferous tubules of pubertal gonads. Northern analysis revealed that the MIS type II …


Developmentally Regulated Polyadenylation Of Two Discrete Messenger Ribonucleic Acids For Mullerian Inhibiting Substance, Mary Lee, Richard Cate, Patricia Donahoe, Gerald Waneck Sep 2014

Developmentally Regulated Polyadenylation Of Two Discrete Messenger Ribonucleic Acids For Mullerian Inhibiting Substance, Mary Lee, Richard Cate, Patricia Donahoe, Gerald Waneck

Mary M. Lee

Mullerian inhibiting substance (MIS) is a 140-kilodalton homodimeric glycoprotein that causes regression of the Mullerian ducts in male embryos, and may also have a role in both males and females in the regulation of germ cell maturation. We examined the ontogeny of MIS messenger RNA (mRNA) in rat testes from midgestation through adulthood and found two discrete MIS mRNA species that are developmentally regulated. The larger 2.0-kilobase species is abundant at embryonic day 14, then decreases in late gestation, and is barely detectable after birth. The smaller 1.8-kilobase species is first noted at embryonic day 18 and is the major …


Transient Hyperthyroidism In An Adolescent With Hydatidiform Mole, Madhusmita Misra, Lynne Levitsky, Mary Lee Sep 2014

Transient Hyperthyroidism In An Adolescent With Hydatidiform Mole, Madhusmita Misra, Lynne Levitsky, Mary Lee

Mary M. Lee

No abstract provided.


Mullerian Inhibiting Substance In Humans: Normal Levels From Infancy To Adulthood, Mary Lee, Patricia Donahoe, Tomonobu Hasegawa, Bernard Silverman, Gretchen Crist, Sharon Best, Yukihiro Hasegawa, Richard Noto, David Schoenfeld, David Maclaughlin Sep 2014

Mullerian Inhibiting Substance In Humans: Normal Levels From Infancy To Adulthood, Mary Lee, Patricia Donahoe, Tomonobu Hasegawa, Bernard Silverman, Gretchen Crist, Sharon Best, Yukihiro Hasegawa, Richard Noto, David Schoenfeld, David Maclaughlin

Mary M. Lee

Mullerian-inhibiting substance (MIS) is a gonadal hormone synthesized by Sertoli cells of the testis and granulosa cells of the ovary. To facilitate the use of MIS for the evaluation of intersex disorders and as a tumor marker in women with MIS-expressing ovarian tumors, we measured MIS in 600 serum samples from males and females. These data show that mean MIS values for males rise rapidly during the first year of life and are highest during late infancy, then gradually decline until puberty. In contrast, MIS values in females are lowest at birth and exhibit a minimal increase throughout the prepubertal …