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Full-Text Articles in Cell Biology

A Naturally Generated Decoy Of The Prostate Apoptosis Response-4 Protein Overcomes Therapy Resistance In Tumors, Nikhil Hebbar, Ravshan Burikhanov, Nidhi Shukla, Shirley Qiu, Yanming Zhao, Kojo S. J. Elenitoba-Johnson, Vivek M. Rangnekar Aug 2017

A Naturally Generated Decoy Of The Prostate Apoptosis Response-4 Protein Overcomes Therapy Resistance In Tumors, Nikhil Hebbar, Ravshan Burikhanov, Nidhi Shukla, Shirley Qiu, Yanming Zhao, Kojo S. J. Elenitoba-Johnson, Vivek M. Rangnekar

Radiation Medicine Faculty Publications

Primary tumors are often heterogeneous, composed of therapy-sensitive and emerging therapy-resistant cancer cells. Interestingly, treatment of therapy-sensitive tumors in heterogeneous tumor microenvironments results in apoptosis of therapy-resistant tumors. In this study, we identify a prostate apoptosis response-4 (Par-4) amino-terminal fragment (PAF) that is released by diverse therapy-sensitive cancer cells following therapy-induced caspase cleavage of the tumor suppressor Par-4 protein. PAF caused apoptosis in cancer cells resistant to therapy and inhibited tumor growth. A VASA segment of Par-4 mediated its binding and degradation by the ubiquitin ligase Fbxo45, resulting in loss of Par-4 proapoptotic function. Conversely, PAF, which contains this VASA ...


Relb Expression Determines The Differential Effects Of Ascorbic Acid In Normal And Cancer Cells, Xiaowei Wei, Yong Xu, Fang Fang Xu, Luksana Chaiswing, David M. Schnell, Teresa Noel, Chi Wang, Jinfei Chen, Daret K. St. Clair, William H. St. Clair Mar 2017

Relb Expression Determines The Differential Effects Of Ascorbic Acid In Normal And Cancer Cells, Xiaowei Wei, Yong Xu, Fang Fang Xu, Luksana Chaiswing, David M. Schnell, Teresa Noel, Chi Wang, Jinfei Chen, Daret K. St. Clair, William H. St. Clair

Toxicology and Cancer Biology Faculty Publications

Cancer cells typically experience higher oxidative stress than normal cells, such that elevating pro-oxidant levels can trigger cancer cell death. Although pre-exposure to mild oxidative agents will sensitize cancer cells to radiation, this pre-exposure may also activate the adaptive stress defense system in normal cells. Ascorbic acid is a prototype redox modulator that when infused intravenously appears to kill cancers without injury to normal tissues; however, the mechanisms involved remain elusive. In this study, we show how ascorbic acid kills cancer cells and sensitizes prostate cancer to radiation therapy while also conferring protection upon normal prostate epithelial cells against radiation-induced ...


Ampa-Kainate Receptor Inhibition Promotes Neurologic Recovery In Premature Rabbits With Intraventricular Hemorrhage, Preeti Dohare, Muhammad T. Zia, Ehsan Ahmed, Asad Ahmed, Vivek Yadala, Praveen Ballabh Mar 2016

Ampa-Kainate Receptor Inhibition Promotes Neurologic Recovery In Premature Rabbits With Intraventricular Hemorrhage, Preeti Dohare, Muhammad T. Zia, Ehsan Ahmed, Asad Ahmed, Vivek Yadala, Praveen Ballabh

NYMC Faculty Publications

Intraventricular hemorrhage (IVH) in preterm infants leads to cerebral inflammation, reduced myelination of the white matter, and neurological deficits. No therapeutic strategy exists against the IVH-induced white matter injury. AMPA-kainate receptor induced excitotoxicity contributes to oligodendrocyte precursor cell (OPC) damage and hypomyelination in both neonatal and adult models of brain injury. Here, we hypothesized that IVH damages white matter via AMPA receptor activation, and that AMPA-kainate receptor inhibition suppresses inflammation and restores OPC maturation, myelination, and neurologic recovery in preterm newborns with IVH. We tested these hypotheses in a rabbit model of glycerol-induced IVH and evaluated the expression of AMPA ...


P-Rex1 Promotes Resistance To Vegf/Vegfr-Targeted Therapy In Prostate Cancer, Hira Lal Goel, Bryan Pursell, Leonard D. Shultz, Dale L. Greiner, Rolf A Brekken, Craig W. Vander Kooi, Arthur M. Mercurio Mar 2016

P-Rex1 Promotes Resistance To Vegf/Vegfr-Targeted Therapy In Prostate Cancer, Hira Lal Goel, Bryan Pursell, Leonard D. Shultz, Dale L. Greiner, Rolf A Brekken, Craig W. Vander Kooi, Arthur M. Mercurio

Molecular and Cellular Biochemistry Faculty Publications

Autocrine VEGF signaling is critical for sustaining prostate and other cancer stem cells (CSCs), and it is a potential therapeutic target, but we observed that CSCs isolated from prostate tumors are resistant to anti-VEGF (bevacizumab) and anti-VEGFR (sunitinib) therapy. Intriguingly, resistance is mediated by VEGF/neuropilin signaling, which is not inhibited by bevacizumab and sunitinib, and it involves the induction of P-Rex1, a Rac GEF, and consequent Rac1-mediated ERK activation. This induction of P-Rex1 is dependent on Myc. CSCs isolated from the PTENpc−/− transgenic model of prostate cancer exhibit Rac1-dependent resistance to bevacizumab. Rac1 inhibition or P-Rex1 downregulation increases ...


Hyaluronidase And Hyaluronan Oligosaccharides Promote Neurological Recovery After Intraventricular Hemorrhage, Govindaiah Vinukonda, Preeti Dohare, Arslan Arshad, Muhammad T. Zia, Sanjeet Panda, Ritesh Korumilli, Praveen Ballabh Jan 2016

Hyaluronidase And Hyaluronan Oligosaccharides Promote Neurological Recovery After Intraventricular Hemorrhage, Govindaiah Vinukonda, Preeti Dohare, Arslan Arshad, Muhammad T. Zia, Sanjeet Panda, Ritesh Korumilli, Praveen Ballabh

NYMC Faculty Publications

Intraventricular hemorrhage (IVH) in premature infants results in inflammation, arrested oligodendrocyte progenitor cell (OPC) maturation, and reduced myelination of the white matter. Hyaluronan (HA) inhibits OPC maturation and complexes with the heavy chain (HC) of glycoprotein inter-α-inhibitor to form pathological HA (HC-HA complex), which exacerbates inflammation. Therefore, we hypothesized that IVH would result in accumulation of HA, and that either degradation of HA by hyaluronidase treatment or elimination of HCs from pathological HA by HA oligosaccharide administration would restore OPC maturation, myelination, and neurological function in survivors with IVH. To test these hypotheses, we used the preterm rabbit model of ...


Age-Associated Methylation Suppresses Spry1, Leading To A Failure Of Re-Quiescence And Loss Of The Reserve Stem Cell Pool In Elderly Muscle., Anne Bigot, William J Duddy, Zamalou G Ouandaogo, Elisa Negroni, Virginie Mariot, Svetlana Ghimbovschi, Brennan Harmon, Aurore Wielgosik, Camille Loiseau, Joseph Devaney, Julie Dumonceaux, Gillian Butler-Browne, Vincent Mouly, Stéphanie Duguez Nov 2015

Age-Associated Methylation Suppresses Spry1, Leading To A Failure Of Re-Quiescence And Loss Of The Reserve Stem Cell Pool In Elderly Muscle., Anne Bigot, William J Duddy, Zamalou G Ouandaogo, Elisa Negroni, Virginie Mariot, Svetlana Ghimbovschi, Brennan Harmon, Aurore Wielgosik, Camille Loiseau, Joseph Devaney, Julie Dumonceaux, Gillian Butler-Browne, Vincent Mouly, Stéphanie Duguez

Genomics and Precision Medicine Faculty Publications

The molecular mechanisms by which aging affects stem cell number and function are poorly understood. Murine data have implicated cellular senescence in the loss of muscle stem cells with aging. Here, using human cells and by carrying out experiments within a strictly pre-senescent division count, we demonstrate an impaired capacity for stem cell self-renewal in elderly muscle. We link aging to an increased methylation of the SPRY1 gene, a known regulator of muscle stem cell quiescence. Replenishment of the reserve cell pool was modulated experimentally by demethylation or siRNA knockdown of SPRY1. We propose that suppression of SPRY1 by age-associated ...


Nuclear Pore Component Nup98 Is A Potential Tumor Suppressor And Regulates Posttranscriptional Expression Of Select P53 Target Genes, Stephan Singer, Ruiying Zhao, Anthony M. Barsotti, Anette Ouwehand, Mina Fazollahi, Elias Coutavas, Kai Breuhahn, Olaf Neumann, Thomas Longerich, Tobias Pusterla, Maureen A. Powers, Keith M. Giles, Peter J. Leedman, Jochen Hess, David Grunwald, Harmen J. Bussemaker, Robert H. Singer, Peter Schirmacher, Carol Prives Nov 2014

Nuclear Pore Component Nup98 Is A Potential Tumor Suppressor And Regulates Posttranscriptional Expression Of Select P53 Target Genes, Stephan Singer, Ruiying Zhao, Anthony M. Barsotti, Anette Ouwehand, Mina Fazollahi, Elias Coutavas, Kai Breuhahn, Olaf Neumann, Thomas Longerich, Tobias Pusterla, Maureen A. Powers, Keith M. Giles, Peter J. Leedman, Jochen Hess, David Grunwald, Harmen J. Bussemaker, Robert H. Singer, Peter Schirmacher, Carol Prives

David Grünwald

The p53 tumor suppressor utilizes multiple mechanisms to selectively regulate its myriad target genes, which in turn mediate diverse cellular processes. Here, using conventional and single-molecule mRNA analyses, we demonstrate that the nucleoporin Nup98 is required for full expression of p21, a key effector of the p53 pathway, but not several other p53 target genes. Nup98 regulates p21 mRNA levels by a posttranscriptional mechanism in which a complex containing Nup98 and the p21 mRNA 3'UTR protects p21 mRNA from degradation by the exosome. An in silico approach revealed another p53 target (14-3-3sigma) to be similarly regulated by Nup98. The ...


Serum Dioxins And Polychlorinated Biphenyls Are Associated With Growth Among Russian Boys, Jane Burns, Paige Williams, Oleg Sergeyev, Susan Korrick, Mary Lee, Boris Revich, Larisa Altshul, Julie Del Prato, Olivier Humblet, Donald Patterson, Wayman Turner, Larry Needham, Mikhail Starovoytov, Russ Hauser Sep 2014

Serum Dioxins And Polychlorinated Biphenyls Are Associated With Growth Among Russian Boys, Jane Burns, Paige Williams, Oleg Sergeyev, Susan Korrick, Mary Lee, Boris Revich, Larisa Altshul, Julie Del Prato, Olivier Humblet, Donald Patterson, Wayman Turner, Larry Needham, Mikhail Starovoytov, Russ Hauser

Mary M. Lee

OBJECTIVE: We evaluated the associations of serum dioxins and polychlorinated biphenyls (PCBs) with longitudinally assessed growth measurements among peripubertal Russian boys.

METHODS: A total of 499 boys from Chapaevsk, Russia, aged 8 to 9 years were enrolled in the study from 2003 to 2005 and were followed prospectively for 3 years. Blood samples were collected and physical examinations were conducted at entry and repeated at annual study visits. Multivariate mixed-effects regression models for repeated measures were used to examine the associations of serum dioxins and PCBs with longitudinal measurements of BMI, height, and height velocity.

RESULTS: Serum dioxin (total 2005 ...


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 ...


Pubertal And Adult Leydig Cell Function In Mullerian Inhibiting Substance-Deficient Mice, Xiufeng Wu, Ramamani Arumugam, Stephen Baker, Mary Lee Sep 2014

Pubertal And Adult Leydig Cell Function In Mullerian Inhibiting Substance-Deficient Mice, Xiufeng Wu, Ramamani Arumugam, Stephen Baker, Mary Lee

Mary M. Lee

Mullerian inhibiting substance (MIS) causes Mullerian duct regression during sexual differentiation and regulates postnatal Leydig cell development. MIS knockout (MIS-KO) mice with targeted deletions of MIS develop Leydig cell hyperplasia, but their circulating androgen concentrations are reportedly unaltered. We compared reproductive hormone profiles, androgen biosynthesis, and the expression of key steroidogenic and metabolic enzymes in MIS-KO and wild-type (WT) mice at puberty (36 d) and sexual maturity (60 d). In pubertal animals, basal testosterone and LH concentrations in plasma were lower in MIS-KO than WT mice, whereas human chorionic gonadotropin-stimulated testosterone concentrations were similar. In adults, basal LH, and both ...


P19ink4d And P18ink4c Cyclin-Dependent Kinase Inhibitors In The Male Reproductive Axis, Gregory Buchold, Patricia Magyar, Ramamani Arumugam, Mary Lee, Deborah O'Brien Sep 2014

P19ink4d And P18ink4c Cyclin-Dependent Kinase Inhibitors In The Male Reproductive Axis, Gregory Buchold, Patricia Magyar, Ramamani Arumugam, Mary Lee, Deborah O'Brien

Mary M. Lee

The loss of the cyclin-dependent kinase inhibitors (CKIs) p18(Ink4c) and p19(Ink4d) leads to male reproductive defects (Franklin et al., 1998. Genes Dev 12: 2899-2911; Zindy et al., 2000. Mol Cell Biol 20: 372-378; Zindy et al., 2001. Mol Cell Biol 21: 3244-3255). In order to assess whether these inhibitors directly or indirectly affect male germ cell differentiation, we examined the expression of p18(Ink4c) and p19(Ink4d) in spermatogenic and supporting cells in the testis and in pituitary gonadotropes. Both p18(Ink4c) and p19(Ink4d) are most abundant in the testis after 18 days of age and are ...


Dioxin Exposure And Age Of Pubertal Onset Among Russian Boys, Susan A. Korrick, Mary M. Lee, Paige L. Williams, Oleg Sergeyev, Jane S. Burns, Donald G. Patterson, Wayman E. Turner, Larry L. Needham, Larisa Altshul, Boris Revich, Russ Hauser Sep 2014

Dioxin Exposure And Age Of Pubertal Onset Among Russian Boys, Susan A. Korrick, Mary M. Lee, Paige L. Williams, Oleg Sergeyev, Jane S. Burns, Donald G. Patterson, Wayman E. Turner, Larry L. Needham, Larisa Altshul, Boris Revich, Russ Hauser

Mary M. Lee

Background: Animal data demonstrate associations of dioxin, furan, and PCB exposures with altered male gonadal maturation. It is unclear whether these associations apply to human populations. Objectives: We investigated the association of dioxins, furans, PCBs and corresponding toxic equivalent (TEQ) concentrations with pubertal onset among boys in a dioxin-contaminated region. Methods: Between 2003-2005, 489 boys were enrolled at ages 8-9 years in a longitudinal study in Chapaevsk, Russia. Pubertal onset - stages 2 or higher for genitalia (G2+) or testicular volume (TV) > 3 ml - was assessed annually between ages 8-12 years. Serum levels at enrollment were analyzed by the Centers for ...


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 ...


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 ...


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 ...


Serum Concentrations Of Organochlorine Pesticides And Growth Among Russian Boys, Jane Burns, Paige Williams, Oleg Sergeyev, Susan Korrick, Mary Lee, Boris Revich, Larisa Altshul, Julie Del Prato, Olivier Humblet, Donald Patterson, Wayman Turner, Mikhail Starovoytov, Russ Hauser Sep 2014

Serum Concentrations Of Organochlorine Pesticides And Growth Among Russian Boys, Jane Burns, Paige Williams, Oleg Sergeyev, Susan Korrick, Mary Lee, Boris Revich, Larisa Altshul, Julie Del Prato, Olivier Humblet, Donald Patterson, Wayman Turner, Mikhail Starovoytov, Russ Hauser

Mary M. Lee

BACKGROUND: Limited human data suggest an association of organochlorine pesticides (OCPs) with adverse effects on children's growth. OBJECTIVE: We evaluated the associations of OCPs with longitudinally assessed growth among peripubertal boys from a Russian cohort with high environmental OCP levels. METHODS: A cohort of 499 boys enrolled in the Russian Children's Study between 2003 and 2005 at 8-9 years of age were followed prospectively for 4 years. At study entry, 350 boys had serum OCPs measured. Physical examinations were conducted at entry and annually. The longitudinal associations of serum OCPs with annual measurements of body mass index (BMI ...


Mullerian Inhibiting Substance In The Diagnosis And Management Of Intersex And Gonadal Abnormalities, Michael Gustafson, Mary Lee, Lara Asmundson, David Maclaughlin, Patricia Donahoe Sep 2014

Mullerian Inhibiting Substance In The Diagnosis And Management Of Intersex And Gonadal Abnormalities, Michael Gustafson, Mary Lee, Lara Asmundson, David Maclaughlin, Patricia Donahoe

Mary M. Lee

Mullerian inhibiting substance (MIS), a gonadal hormone important in sexual differentiation, is high (10 to 70 ng/mL) in human male serum postnatally for several years before declining during the peripubertal period, but is undetectable in female serum until the onset of puberty. The sexually dimorphic secretion of MIS suggested possibilities for its use in several clinical settings. Thirty-one patients with intersex and gonadal anomalies from 17 institutions were therefore evaluated between 1989 and 1992 with an MIS enzyme-linked immunosorbent assay (ELISA). Serum MIS levels correlated with the presence of testicular tissue in two patients with suspected anorchia, five patients ...


Campylobacter Meningitis In Childhood, Mary Lee, Robert Welliver, Leonard La Scolea Sep 2014

Campylobacter Meningitis In Childhood, Mary Lee, Robert Welliver, Leonard La Scolea

Mary M. Lee

No abstract provided.


Mentoring Fathers Of Children Newly Diagnosed With T1dm, Susan Sullivan-Bolyai, Carol Bova, Mary Lee, Philip Gruppuso Sep 2014

Mentoring Fathers Of Children Newly Diagnosed With T1dm, Susan Sullivan-Bolyai, Carol Bova, Mary Lee, Philip Gruppuso

Mary M. Lee

PURPOSE: To pilot test a social support intervention for fathers of children (T1DM).

DESIGN AND METHODS: The pilot study was part of a larger randomized, controlled clinical trial. Father participants (28 fathers of children newly diagnosed) were recruited from two pediatric diabetes centers. For 12 months fathers (n = 19) and their spouses in the experimental arm received social support (home visits and phone calls). Control group fathers (n = 9) and their spouses received the phone number of an experienced parent (but not formally educated to provide social support) to call as needed.

RESULTS: Fathers in the intervention group had significantly ...


Key Factors In The Regulation Of Fetal And Postnatal Leydig Cell Development, Xiufeng Wu, Shengqin Wan, Mary Lee Sep 2014

Key Factors In The Regulation Of Fetal And Postnatal Leydig Cell Development, Xiufeng Wu, Shengqin Wan, Mary Lee

Mary M. Lee

The primary function of testicular Leydig cells is the production of androgens to promote sexual differentiation in the fetus, secondary sexual maturation at puberty, and spermatogenesis in the adult. The fetal and postnatal (adult) populations of Leydig cells differ morphologically and have distinct profiles of gene expression. As postnatal Leydig cells differentiate, they transition through three discrete maturational stages characterized by decreasing proliferative rate and increasing testosterone biosynthetic capacity. In this review, we discuss the development of both fetal and postnatal Leydig cells and review the regulation of this process by some of the key hormones and growth factors.


The Influence Of Endocrine Disruptors On Pubertal Timing, Elka Jacobson-Dickman, Mary Lee Sep 2014

The Influence Of Endocrine Disruptors On Pubertal Timing, Elka Jacobson-Dickman, Mary Lee

Mary M. Lee

PURPOSE OF REVIEW: Overview of the effects of endocrine disruptors on pubertal timing. RECENT FINDINGS: Epidemiologic studies in humans support animal data demonstrating that exposures to endocrine-disrupting compounds have pronounced effects on pubertal timing and that the timing of endocrine-disrupting compound exposure and the specific agent causes different outcomes. Recent studies confirm subtle effects of lead, dioxins, and phytoestrogens on delaying onset of puberty and demonstrate an association of phthalates and polychlorinated biphenyls with earlier breast development and menarche, respectively. These studies, however, are complicated by mixed exposures of compounds which individually may have opposing actions on the reproductive axis ...


Alterations In The Pulsatile Mode Of Growth Hormone Release In Men And Women With Insulin-Dependent Diabetes Mellitus, Christopher Asplin, Amilton Faria, Elizabeth Carlsen, Veronica Vaccaro, Richard Barr, Ali Iranmanesh, Mary Lee, Johannes Veldhuis, William Evans Sep 2014

Alterations In The Pulsatile Mode Of Growth Hormone Release In Men And Women With Insulin-Dependent Diabetes Mellitus, Christopher Asplin, Amilton Faria, Elizabeth Carlsen, Veronica Vaccaro, Richard Barr, Ali Iranmanesh, Mary Lee, Johannes Veldhuis, William Evans

Mary M. Lee

The mechanisms responsible for the elevated levels of circulating GH observed in diabetes mellitus (DM) remain incompletely defined. To assess the episodic fluctuations in serum GH as a reflection of hypothalamic-pituitary activity, we accumulated GH concentration-time series in a total of 48 adult men and women with and without insulin-dependent DM by obtaining serum samples at 10-min intervals over 24 h. Significant pulses of GH release were subsequently identified and characterized by an objective, statistically based pulse detection algorithm (Cluster) and fixed circadian (24-h) periodicities of secretory activity, resolved using Fourier expansion timeseries analysis. Compared to those in age-matched controls ...


Predictors Of Serum Dioxins And Pcbs Among Peripubertal Russian Boys, Jane S. Burns, Paige L. Williams, Oleg Sergeyev, Susan Korrick, Mary M. Lee, Boris Revich, Larisa Altshul, Donald G. Patterson, Wayman E. Turner, Larry L. Needham, Igor Saharov, Russ Hauser Sep 2014

Predictors Of Serum Dioxins And Pcbs Among Peripubertal Russian Boys, Jane S. Burns, Paige L. Williams, Oleg Sergeyev, Susan Korrick, Mary M. Lee, Boris Revich, Larisa Altshul, Donald G. Patterson, Wayman E. Turner, Larry L. Needham, Igor Saharov, Russ Hauser

Mary M. Lee

BACKGROUND: Although sources and routes of exposure to dioxins and polychlorinated biphenyls (PCBs) have been studied, information regarding exposure among children is limited. Breast-feeding and diet are two important contributors to early life exposure. To further understand other significant contributors to childhood exposure, we studied a cohort of children from a city with high environmental dioxin levels. OBJECTIVES: We investigated predictors of serum concentrations of polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs)/co-planar PCBs (C-PCBs), toxic equivalents (TEQs), and PCBs among 8- to 9-year-old boys in Chapaevsk, Russia. METHODS: We used general linear regression models to explore associations of log(10 ...


Hypothyroidism In Down Syndrome: Screening Guidelines And Testing Methodology, Olga Hardy, Gordon Worley, Mary Lee, Shu Chaing, Joanne Mackey, Blythe Crissman, Priya Kishnani Sep 2014

Hypothyroidism In Down Syndrome: Screening Guidelines And Testing Methodology, Olga Hardy, Gordon Worley, Mary Lee, Shu Chaing, Joanne Mackey, Blythe Crissman, Priya Kishnani

Mary M. Lee

No abstract provided.


Mullerian-Inhibiting Substance Inhibits Rat Leydig Cell Regeneration After Ethylene Dimethanesulphonate Ablation, Antonio Salva, Matthew Hardy, Xiufeng Wu, Chantal Sottas, David Maclaughlin, Patricia Donahoe, Mary Lee Sep 2014

Mullerian-Inhibiting Substance Inhibits Rat Leydig Cell Regeneration After Ethylene Dimethanesulphonate Ablation, Antonio Salva, Matthew Hardy, Xiufeng Wu, Chantal Sottas, David Maclaughlin, Patricia Donahoe, Mary Lee

Mary M. Lee

The postnatal development of Leydig cell precursors is postulated to be controlled by Sertoli cell secreted factors, which may have a determinative influence on Leydig cell number and function in sexually mature animals. One such hormone, Mullerian inhibiting substance (MIS), has been shown to inhibit DNA synthesis and steroidogenesis in primary Leydig cells and Leydig cell tumor lines. To further delineate the effects of MIS on Leydig cell proliferation and steroidogenesis, we employed the established ethylene dimethanesulphonate (EDS) model of Leydig cell regeneration. Following EDS ablation of differentiated Leydig cells in young adult rats, recombinant MIS or vehicle was delivered ...


Association Of Blood Lead Levels With Onset Of Puberty In Russian Boys, Russ Hauser, Oleg Sergeyev, Susan Korrick, Mary M. Lee, Boris Revich, Elana Gitin, Jane S. Burns, Paige L. Williams Sep 2014

Association Of Blood Lead Levels With Onset Of Puberty In Russian Boys, Russ Hauser, Oleg Sergeyev, Susan Korrick, Mary M. Lee, Boris Revich, Elana Gitin, Jane S. Burns, Paige L. Williams

Mary M. Lee

BACKGROUND: Epidemiologic studies suggest a temporal trend of earlier onset and longer duration of puberty, raising concerns regarding the potential impact of environmental factors on pubertal development. Lead exposure has been associated with delayed pubertal onset in girls; however, epidemiologic data in boys are limited. METHODS: We used multivariable logistic regression models to explore the cross-sectional association of blood lead levels with growth and pubertal onset based on physician-assessed testicular volume (TV) and pubertal staging in 489 boys 8-9 years of age from Chapaevsk, Russia. We used multivariable linear regression models to assess associations of blood lead levels with somatic ...


Mullerian Inhibiting Substance Is Present In Embryonic Testes Of Dogs With Persistent Mullerian Duct Syndrome, Vicki Meyers-Wallen, Mary Lee, T. Manganaro, T. Kuroda, David Maclaughlin, Patricia Donahoe Sep 2014

Mullerian Inhibiting Substance Is Present In Embryonic Testes Of Dogs With Persistent Mullerian Duct Syndrome, Vicki Meyers-Wallen, Mary Lee, T. Manganaro, T. Kuroda, David Maclaughlin, Patricia Donahoe

Mary M. Lee

Mullerian Inhibiting Substance (MIS) causes regression of the Mullerian ducts during a critical period in embryonic development in male mammals. In Persistent Mullerian Duct Syndrome (PMDS), an autosomal recessive trait in humans and dogs, the Mullerian ducts fail to regress in otherwise normal males. Previously we reported that PMDS-affected dogs produce bioactive testicular MIS postnatally. The purpose of the present study was to determine whether PMDS-affected canine embryos appropriately express MIS mRNA and protein during the critical period for Mullerian duct regression. Homozygous (PMDS-affected) and normal canine embryos were removed from timed pregnancies. Gonadal sex and the degree of Mullerian ...


Mis/Amh In The Assessment Of Cryptorchidism And Intersex Conditions, Mary Lee, Madhusmita Misra, Patricia Donahoe, David Maclaughlin Sep 2014

Mis/Amh In The Assessment Of Cryptorchidism And Intersex Conditions, Mary Lee, Madhusmita Misra, Patricia Donahoe, David Maclaughlin

Mary M. Lee

Mullerian inhibiting substance (MIS), also known as anti-Mullerian hormone (AMH), causes Mullerian duct involution during male sexual differentiation and also has a postnatal regulatory role in the gonads. Serum MIS/AMH has a gonad specific pattern of expression and its concentrations are sexually dimorphic in children; hence measurement of serum MIS/AMH helps in the evaluation of children with gonadal disorders. In boys with cryptorchidism (non-palpable gonads), serum MIS/AMH correlates with testicular tissue. A measurable value is predictive of undescended testes while an undetectable value is highly suggestive of anorchia. In minimally virilized phenotypic females, MIS/AMH helps differentiate ...


Insulin Pump Therapy In Toddlers And Preschool Children With Type 1 Diabetes Mellitus, Jean Litton, Alan Rice, Nancy Friedman, Jon Oden, Mary Lee, Michael Freemark Sep 2014

Insulin Pump Therapy In Toddlers And Preschool Children With Type 1 Diabetes Mellitus, Jean Litton, Alan Rice, Nancy Friedman, Jon Oden, Mary Lee, Michael Freemark

Mary M. Lee

OBJECTIVE: To test whether glycemic control in young children could be achieved more effectively and safely by using continuous insulin infusions administered by insulin pumps.

STUDY DESIGN: We analyzed the effects of pump therapy in nine toddlers in whom type 1 diabetes developed between the ages of 10 and 40 months. After a mean of 13.7 months of therapy with multiple daily injections, patients were treated with insulin pumps for periods ranging from 7 to 19 months (mean, 12.7 months).

RESULTS: Before initiation of pump therapy, HbA1c levels averaged 9.5% +/- 0.4%, and patients had a mean ...