32 results on '"Anderson, Greg"'
Search Results
2. Programming conformational cooperativity to regulate allosteric protein-oligonucleotide signal transduction
- Author
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Liang, Yuan, Qie, Yunkai, Yang, Jing, Wu, Ranfeng, Cui, Shuang, Zhao, Yuliang, Anderson, Greg J., Nie, Guangjun, Li, Suping, and Zhang, Cheng
- Published
- 2023
- Full Text
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3. Monitoring circulating platelet activity to predict cancer-associated thrombosis
- Author
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Li, Bozhao, Lu, Zefang, Yang, Zhenlin, Zhang, Xiuping, Wang, Meiqi, Chu, Tianjiao, Wang, Peina, Qi, Feilong, Anderson, Greg J., Jiang, Ershuai, Song, Zhenchuan, Nie, Guangjun, and Li, Suping
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- 2023
- Full Text
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4. Physiological regulation of leptin as an integrative signal of reproductive readiness
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Evans, Maggie C., Campbell, Rebecca E., and Anderson, Greg M.
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- 2022
- Full Text
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5. Androgen receptor actions on AgRP neurons are not a major cause of reproductive and metabolic impairments in peripubertally androgenized mice.
- Author
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Kerbus, Romy I., Decourt, Caroline, Inglis, Megan A., Campbell, Rebecca E., and Anderson, Greg M.
- Subjects
ANDROGEN receptors ,NEURONS ,POLYCYSTIC ovary syndrome ,INSULIN resistance ,METABOLIC disorders ,PROSTATE cancer - Abstract
Excess levels of circulating androgens during prenatal or peripubertal development are an important cause of polycystic ovary syndrome (PCOS), with the brain being a key target. Approximately half of the women diagnosed with PCOS also experience metabolic syndrome; common features including obesity, insulin resistance and hyperinsulinemia. Although a large amount of clinical and preclinical evidence has confirmed this relationship between androgens and the reproductive and metabolic features of PCOS, the mechanisms by which androgens cause this dysregulation are unknown. Neuron‐specific androgen receptor knockout alleviates some PCOS‐like features in a peripubertal dihydrotestosterone (DHT) mouse model, but the specific neuronal populations mediating these effects are undefined. A candidate population is the agouti‐related peptide (AgRP)‐expressing neurons, which are important for both reproductive and metabolic function. We used a well‐characterised peripubertal androgenized mouse model and Cre‐loxP transgenics to investigate whether deleting androgen receptors specifically from AgRP neurons can alleviate the induced reproductive and metabolic dysregulation. Androgen receptors were co‐expressed in 66% of AgRP neurons in control mice, but only in <2% of AgRP neurons in knockout mice. The number of AgRP neurons was not altered by the treatments. Only 20% of androgen receptor knockout mice showed rescue of DHT‐induced androgen‐induced anovulation and acyclicity. Furthermore, androgen receptor knockout did not rescue metabolic dysfunction (body weight, adiposity or glucose and insulin tolerance). While we cannot rule out developmental compensation in our model, these results suggest peripubertal androgen excess does not markedly influence Agrp expression and does not dysregulate reproductive and metabolic function through direct actions of androgens onto AgRP neurons. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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6. The Role of RFRP Neurons in the Allostatic Control of Reproductive Function.
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Evans, Maggie C. and Anderson, Greg M.
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NEURONS , *GONADOTROPIN releasing hormone , *PEPTIDES , *PUBERTY , *PRECOCIOUS puberty , *HYPOTHALAMUS - Abstract
Reproductive function is critical for species survival; however, it is energetically costly and physically demanding. Reproductive suppression is therefore a physiologically appropriate adaptation to certain ecological, environmental, and/or temporal conditions. This 'allostatic' suppression of fertility enables individuals to accommodate unfavorable reproductive circumstances and safeguard survival. The mechanisms underpinning this reproductive suppression are complex, yet culminate with the reduced secretion of gonadotropin-releasing hormone (GnRH) from the hypothalamus, which in turn suppresses gonadotropin release from the pituitary, thereby impairing gonadal function. The focus of this review will be on the role of RFamide-related peptide (RFRP) neurons in different examples of allostatic reproductive suppression. RFRP neurons release the RFRP-3 peptide, which negatively regulates GnRH neurons and thus appears to act as a 'brake' on the neuroendocrine reproductive axis. In a multitude of predictable (e.g., pre-puberty, reproductive senescence, and seasonal or lactational reproductive quiescence) and unpredictable (e.g., metabolic, immune and/or psychosocial stress) situations in which GnRH secretion is suppressed, the RFRP neurons have been suggested to act as modulators. This review examines evidence for and against these roles. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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7. SURVEY OF INDIANA LAW OF PROFESSIONAL RESPONSIBILITY (2021-2022).
- Author
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MEIRING, ADRIENNE L., ANDERSON, GREG, and BIBBS, STEPHANIE
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PROFESSIONAL ethics , *RESPONSIBILITY , *LEGAL ethics , *PER curiam opinions , *CORRUPT practices of lawyers , *COURTESY - Abstract
The article presents the results of the survey of the law of professional responsibility in Indiana from August 2021 to September 2022. Also cited are the per curiam rulings by the state's Supreme Court imposing sanctions for lawyer misconduct, the need for civility in both trials and disciplinary proceedings, and the application of the Rules of Professional Conduct to common ethical dilemmas.
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- 2023
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8. Neuronal Ptpn1 and Socs3 deletion improves metabolism but not anovulation in a mouse polycystic ovary syndrome model.
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Kerbus, Romy I., Inglis, Megan A., and Anderson, Greg M.
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POLYCYSTIC ovary syndrome ,SUPPRESSORS of cytokine signaling ,PROTEIN-tyrosine phosphatase ,CORPUS luteum ,ANOVULATION ,INFERTILITY ,22Q11 deletion syndrome - Abstract
Polycystic ovary syndrome (PCOS) is one of the most common causes of infertility in women. Approximately half of the diagnosed individuals also experience the metabolic syndrome. Central and peripheral resistance to the hormones insulin and leptin have been reported to contribute to both metabolic and reproductive dysregulation. In PCOS and preclinical PCOS animal models, circulating insulin and leptin levels are often increased in parallel with the development of hormone resistance; however, it remains uncertain whether these changes contribute to the PCOS state. In this study, we tested whether central actions of protein tyrosine phosphatase 1B (PTP1B) and suppressor of cytokine signaling 3 (SOCS3), negative regulators of insulin and leptin signaling pathways, respectively, play a role in the development of PCOS-like phenotype. A peripubertal dihydrotestosterone (DHT) excess PCOS-like mouse model was used, which exhibits both metabolic and reproductive dysfunction. Mice with knockout of the genes encoding PTP1B and SOCS3 from forebrain neurons were generated, and metabolic and reproductive functions were compared between knockout and control groups. DHT treatment induced mild insulin resistance but not leptin resistance, so the role of SOCS3 could not be tested. As expected, DHT excess abolished estrous cycles and corpora lutea presence and caused increased visceral adiposity and fasting glucose levels. Knockout mice did not show any rescue of reproductive dysfunction but did have reduced adiposity compared to the control DHT mice. These data suggest that negative regulation of central insulin signaling by PTP1B is not responsible for peripubertal DHT excess-induced reproductive impairments but may mediate its increased adiposity effects. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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9. A survey of amalgam use to guide dental education curriculums.
- Author
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Khodayari, Aynaz, Jessani, Abbas, Adeniyi, Abiola, Anderson, Greg, Tam, Laura E., and De Souza, Grace M.
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Objectives: To identify behavioral, preferential, and professional factors influencing the use of amalgam in private practices; and to compare the incidence of the placement of amalgam versus composite resin restorations in the province of Ontario and its pedagogical implications on dental curricula. Methods: Participants responded anonymously to a 23‐question online survey about their current use of dental amalgam and composite resins as well as their opinions regarding both dental materials. The explanatory variables were associated bivariately with the outcome variables, and the most significant predictors were identified using the multivariate analysis. Results: Higher percentages of amalgam use were reported among clinicians who trained in Canada only (P =.009), who graduated before 1980 (p = <.001) and who work outside private practice (p = <.001). Familiarity with amalgam was higher among clinicians who are female (p = <.001), older (p = <.001), trained only in Canada (p =.017), who graduated prior to 2000 (p = <.001), and who work in locations with populations over 100,000 (p =.042). Familiarity with composite resin was higher among clinicians who graduated more recently (p =.002). A higher percentage of females (p = <.001), younger clinicians (p = <.001), recent graduates (p = <.001), and clinicians who work in private practice (p =.043) suggested that over 50% of dental student training time be allocated to amalgam. Conclusions: Decreased amalgam use was reported by later dental graduates and private practitioners; this may be impacted by familiarity with dental amalgam. As amalgam remains a safe and effective dental material, its removal may not be prudent. Dental educators play a crucial role in the future of amalgam opinion and use. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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10. A novel ruthenium-silver based antimicrobial potentiates aminoglycoside activity against Pseudomonas aeruginosa.
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Donkor, Gracious Yoofi, Anderson, Greg M., Stadler, Michael, Tawiah, Patrick Ofori, Orellano, Carl D., Edwards, Kevin A., and Dahl, Jan-Ulrik
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- 2023
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11. Teaching Trade during COVID: Conducting a WTO Simulation through Remote Delivery.
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Bratt, Duane, Anderson, Greg, Kukucha, Chris, and Sabiston, David
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COVID-19 pandemic , *INTERNATIONAL competition , *POLITICAL science , *COLLEGE teaching , *COVID-19 - Abstract
In Fall 2020, all universities in Alberta went with remote delivery of classes due to COVID-19 restrictions. This provided not only teaching challenges, but also opportunities. Professors at three Canadian universities teaching similar undergraduate courses in international political economy decided to use the challenges/opportunities of COVID-19 restrictions to experiment with a World Trade Organization (WTO) simulation across three campuses through remote delivery. Simulations are frequently used for teaching in political science, but what was unusual was doing it through remote delivery. This paper assesses the effectiveness of the experiment. It traces the origins/evolution of the idea, learning objectives for the students, preparation by the professors to design the WTO simulation, and the experience of the actual simulation. It also addresses the challenges (technological, timing, assignments, grading, student anxiety, etc.). In addition, it identifies the steps that were taken to reduce and mitigate the challenges. It also acknowledges the mistakes that were made by the professors in designing and implementing the assignment. These observations and reflections are informed by the materials that the professors prepared, their thoughts on the experience, and the feedback from participating students (through official student evaluations as well as a special survey instrument). It provides lessons for future online simulations. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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12. RFamide-related Peptide 3 Signaling via Neuropeptide FF Receptor Stimulates Prolactin Secretion in Female Rats.
- Author
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Aquino, Nayara S S, Mansano, Naira S, Vieira, Fernanda A S, Silva, Kaoma S C, Gusmao, Daniela O, Anderson, Greg M, Frazao, Renata, Reis, Adelina M, and Szawka, Raphael E
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PEPTIDES ,NEUROPEPTIDES ,PROLACTIN - Abstract
The RF-amide peptides comprise a family of neuropeptides that includes the kisspeptin (Kp), the natural ligand of kisspeptin receptor (Kiss1r), and the RFamide-related peptide 3 (RFRP-3) that binds preferentially to the neuropeptide FF receptor 1 (Npffr1). Kp stimulates prolactin (PRL) secretion through the inhibition of tuberoinfundibular dopaminergic (TIDA) neurons. Because Kp also has affinity to Npffr1, we investigated the role of Npffr1 in the control of PRL secretion by Kp and RFRP-3. Intracerebroventricular (ICV) injection of Kp increased PRL and LH secretion in ovariectomized, estradiol-treated rats. The unselective Npffr1 antagonist RF9 prevented these responses, whereas the selective antagonist GJ14 altered PRL but not LH levels. The ICV injection of RFRP-3 in ovariectomized, estradiol-treated rats increased PRL secretion, which was associated with a rise in the dopaminergic activity in the median eminence, but had no effect on LH levels. The RFRP-3-induced increase in PRL secretion was prevented by GJ14. Moreover, the estradiol-induced PRL surge in female rats was blunted by GJ14, along with an amplification of the LH surge. Nevertheless, whole-cell patch clamp recordings showed no effect of RFRP-3 on the electrical activity of TIDA neurons in dopamine transporter-Cre recombinase transgenic female mice. We provide evidence that RFRP-3 binds to Npffr1 to stimulate PRL release, which plays a role in the estradiol-induced PRL surge. This effect of RFRP-3 is apparently not mediated by a reduction in the inhibitory tone of TIDA neurons but possibly involves the activation of a hypothalamic PRL-releasing factor. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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13. Leptin, but not Estradiol, Signaling in PACAP Neurons Modulates Puberty Onset.
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Evans, Maggie C, Wallace, Elliot G, Ancel, Caroline M, and Anderson, Greg M
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ESTRADIOL ,HYPOGONADISM ,PITUITARY adenylate cyclase activating polypeptide - Abstract
The adipose-derived hormone leptin critically modulates reproductive function, such that its absence results in hypothalamic hypogonadism. Pituitary adenylate cyclase-activating polypeptide (PACAP)-expressing neurons are potential mediators of leptin's action on the neuroendocrine reproductive axis because they are leptin-sensitive and involved in both feeding behavior and reproductive function. In the complete absence of PACAP, male and female mice exhibit metabolic and reproductive abnormalities, yet there is some sexual dimorphism in the reproductive impairments. We tested whether PACAP neurons play a critical and/or sufficient role in mediating leptin's effects on reproductive function by generating PACAP-specific leptin receptor (LepR) knockout and rescue mice, respectively. We also generated PACAP-specific estrogen receptor alpha knockout mice to determine whether estradiol-dependent regulation of PACAP was critically involved in the control of reproductive function and whether it contributed to the sexually dimorphic effects of PACAP. We showed that LepR signaling in PACAP neurons is critically involved in the timing of female, but not male, puberty onset, but not fertility. Rescuing LepR-PACAP signaling in otherwise LepR-deficient mice was unable to rescue the reproductive deficits observed in LepR null mice but led to a marginal improvement in body weight and adiposity in females. Finally, PACAP-specific estrogen receptor alpha knockout did not lead to any changes in body weight or puberty onset compared with control mice. These data highlight that PACAP is a critical mediator of some of leptin's, but not estradiol's, influence on puberty onset in females, but is not critically involved in relaying leptin's effects in males or in adult females. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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14. Deletion of Androgen Receptors From Kisspeptin Neurons Prevents PCOS Features in a Letrozole Mouse Model.
- Author
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Decourt, Caroline, Watanabe, Yugo, Evans, Maggie C, Inglis, Megan A, Fisher, Lorryn C, Jasoni, Christine L, Campbell, Rebecca E, and Anderson, Greg M
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POLYCYSTIC ovary syndrome ,ANDROGEN receptors ,KISSPEPTIN neurons - Abstract
Polycystic ovarian syndrome (PCOS) is the leading cause of anovulatory infertility and is a heterogenous condition associated with a range of reproductive and metabolic impairments. While its etiology remains unclear, hyperandrogenism and impaired steroid negative feedback have been identified as key factors underpinning the development of PCOS-like features both clinically and in animal models. We tested the hypothesis that androgen signaling in kisspeptin-expressing neurons, which are key drivers of the neuroendocrine reproductive axis, is critically involved in PCOS pathogenesis. To this end, we used a previously validated letrozole (LET)-induced hyperandrogenic mouse model of PCOS in conjunction with Cre-lox technology to generate female mice exhibiting kisspeptin-specific deletion of androgen receptor (KARKO mice) to test whether LET-treated KARKO females are protected from the development of reproductive and metabolic PCOS-like features. LET-treated mice exhibited hyperandrogenism, and KARKO mice exhibited a significant reduction in the coexpression of kisspeptin and androgen receptor mRNA compared to controls. In support of our hypothesis, LET-treated KARKO mice exhibited improved estrous cyclicity, ovarian morphology, and insulin sensitivity in comparison to LET-treated control females. However, KARKO mice were not fully protected from the effects of LET-induced hyperandrogenism and still exhibited reduced corpora lutea numbers and increased body weight gain. These data indicate that increased androgen signaling in kisspeptin-expressing neurons plays a critical role in PCOS pathogenesis but highlight that other mechanisms are also involved. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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15. Central Irisin Signaling Is Required for Normal Timing of Puberty in Female Mice.
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Decourt, Caroline, Evans, Maggie C, Inglis, Megan A, and Anderson, Greg M
- Abstract
Timing of puberty requires exquisite coordination of genes, hormones, and brain circuitry. An increasing level of body adiposity, signaled to the brain via the fat-derived hormone leptin, is recognized as a major factor controlling puberty onset. However, it is clear that leptin is not the only metabolic cue regulating puberty, and that developmental regulation of this process also involves tissues other than adipose, with muscle development potentially playing a role in the timing of puberty. The proteolytic processing of fibronectin type 3 domain-containing protein 5 (FNDC5) releases a hormone, irisin. Irisin is primarily produced by muscle and is released into circulation, where levels increase dramatically as puberty approaches. We investigated the effects of a global deletion of the Fndc5 gene on pubertal timing. The absence of irisin induced a delay in puberty onset in female knockout mice compared with controls, without affecting body weight or gonadotropin-releasing hormone (GnRH) neuronal density. We next treated pre-pubertal wild-type male and female mice with an irisin receptor antagonist, cilengitide, for 7 days and observed a delay in first estrus occurrence compared to vehicle-treated control mice. Male puberty timing was unaffected. Next, we deleted the irisin receptor (integrin subunit alpha V) in all forebrain neurons and found a delay in the occurrence of first estrus in knockout females compared to controls. Taken together, these data suggest irisin plays a role in the timing of puberty onset in female mice via a centrally mediated mechanism. [ABSTRACT FROM AUTHOR]
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- 2023
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16. Agouti‐related peptide neuronal silencing overcomes delayed puberty in neonatally underfed male mice.
- Author
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Decourt, Caroline, Connolly, George A. D. P., Ancel, Caroline, Inglis, Megan A., and Anderson, Greg M.
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PEPTIDES ,PUBERTY ,HYPOTHALAMIC hormones ,MICE ,FOOD consumption - Abstract
Agouti‐related peptide (AgRP) neurons are thought to indirectly regulate the activity of hypothalamic gonadotrophin‐releasing hormone neurons which control fertility. AgRP neurons also drive caloric intake and are modulated by metabolically‐relevant hormones, providing a link to the hypothalamic–pituitary‐gonadal axis. In mice expressing Cre‐dependant designer receptors (DREADDs) in AgRP neurons, we activated or silenced these neurons in vivo using the synthetic ligand clozapine‐N‐oxide (CNO) to observe the effect of AgRP neuron activity on timing of puberty. To validate these animals, we chronically treated both stimulatory (hM3Dq) and inhibitory (hM4Di) DREADD × AgRP‐Cre mice with CNO, observing a pronounced increase and decrease of food intake, respectively, consistent with the known orexigenic effects of these neurons. RNAscope was performed to visually confirm the activation of AgRP neurons. Puberty onset was assessed in males and females. There was no effect on preputial separation in males or vaginal opening and first oestrus in females after CNO treatment from day 26 to 30 to chronically modulate AgRP neurons. Next, to determine whether the delay in puberty onset occurring in response to neonatal underfeeding could be overcome by inhibiting AgRP neuronal activity, mice were raised in large (neonatally underfed) or normal litter sizes. The delay in puberty from underfeeding was completely reversed in CNO‐treated AgRP‐hM4Di male mice. These data highlight the inhibitory role of AgRP neurons to delay puberty onset when undernutrition occurs during the neonatal period, at least in male mice. Trail registration number: JNE‐22‐0081‐OA.R2 [ABSTRACT FROM AUTHOR]
- Published
- 2022
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17. Fetal resorption coincides with dysregulated LH secretion in AMH-overexpressing mice.
- Author
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Yiran Zhou, Neyt, Christine, Batchelor, Nicola J., Kelley, Rebecca L., Amsak, Karmilla Jaafar, Anderson, Greg M., Oorschot, Dorothy E., Jasoni, Christine L., Girling, Jane E., and Pankhurst, Michael W.
- Subjects
ANTI-Mullerian hormone ,SECRETION ,EMBRYO transfer ,MICE ,DEVELOPMENTAL delay - Abstract
Female anti-Müllerian hormone (AMH) overexpressing (Thy1.2-AMH
Tg/0 ) mice experience fetal resorption (miscarriage) by mid-gestation. This study examined whether the ovary, uterine implantation sites and hypothalamus are potential sites of AMH action, as AMH type-2 receptor (AMHR2) expression is reported in each tissue. Pregnancy in Thy1.2-AMHTg/0 mice was compared to wild-type (WT) mice via histological examination of implantation sites, hormone assays, embryo culture and embryo transfer. Uterine AMH and AMHR2 expression was examined by RT-qPCR and immunohistochemistry. The first signs of fetal resorption in the Thy1.2-AMHTg/0 dams occurred at embryonic day 9.5 (E9.5) with 100% of fetuses resorbing by E13.5. Cultured embryos from Thy1.2-AMHTg/0 dams had largely normal developmental rates but a small proportion experienced a minor developmental delay relative to embryos from WT dams. However, embryos transferred from WT donor females always failed to survive to term when transferred into Thy1.2-AMHTg/0 dams. Amh and Amhr2 mRNA was detected in the gravid uterus but at very low levels relative to expression in the ovaries. Progesterone and estradiol levels were not significantly different between WT and Thy1.2-AMHTg/0 dams during pregnancy but luteinizing hormone (LH) levels were significantly elevated in Thy1.2-AMHTg/0 dams at E9.5 and E13.5 relative to WT dams. Collectively, these experiments suggest that AMH overexpression does not cause fetal resorption through an effect on oocytes or preimplantation embryo development. The Thy1.2-AMHTg/0 fetal resorption phenotype is nearly identical to that of transgenic LH overexpression models, suggesting that neuroendocrine mechanisms may be involved in the cause of the miscarriage. [ABSTRACT FROM AUTHOR]- Published
- 2022
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18. Microsoft Teams is letting our team down
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Anderson, Greg
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Science and technology ,Microsoft Teams (Messaging software) - Abstract
While reading about Microsoft Teams on pages 90-91 of the Sept 2021 (#184) issue of MacLife, I noticed that no mention was made of what I and those I work [...]
- Published
- 2021
19. Vascular Complications in Sports Surgery: Diagnosis and Management.
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Dart, Scott E., Anderson, Greg R., Miller, Mark D., and Werner, Brian C.
- Subjects
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SHOULDER joint , *ARTHROSCOPY , *ORTHOPEDICS , *KNEE , *SHOULDER - Abstract
Orthopedic sports surgery of the knee and shoulder is generally considered to be safe and effective. Vascular complications can occur during or after arthroscopy of either joint. A thorough understanding of anatomy, particularly when placing portals in non-routine locations, is extremely important. Prompt recognition of any vascular complication is of significant importance. This review will discuss the potential vascular complications for both knee and shoulder sports surgery, review the relevant anatomy, and discuss the treatment and expected outcome of each. [ABSTRACT FROM AUTHOR]
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- 2022
- Full Text
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20. Deletion of PTP1B From Brain Neurons Partly Protects Mice From Diet-Induced Obesity and Minimally Improves Fertility.
- Author
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Ancel, Caroline M, Evans, Maggie C, Kerbus, Romy I, Wallace, Elliot G, and Anderson, Greg M
- Abstract
Reproductive dysfunction in women has been linked to high caloric diet (HCD)-feeding and obesity. Central resistance to leptin and insulin have been shown to accompany diet-induced infertility in rodent studies, and we have previously shown that deleting suppressor of cytokine signaling 3, which is a negative regulator of leptin signaling, from all forebrain neurons partially protects mice from HCD-induced infertility. In this study, we were interested in exploring the role of protein tyrosine phosphatase 1B (PTP1B), which is a negative regulator of both leptin and insulin signaling, in the pathophysiology of HCD-induced obesity and infertility. To this end, we generated male and female neuron-specific PTP1B knockout mice and compared their body weight gain, food intake, glucose tolerance, and fertility relative to control littermates under both normal calorie diet and HCD feeding conditions. Both male and female mice with neuronal PTP1B deletion exhibited slower body weight gain in response to HCD feeding, yet only male knockout mice exhibited improved glucose tolerance compared with controls. Neuronal PTP1B deletion improved the time to first litter in HCD-fed mice but did not protect female mice from eventual HCD-induced infertility. While the mice fed a normal caloric diet remained fertile throughout the 150-day period of assessment, HCD-fed females became infertile after producing only a single litter, regardless of their genotype. These data show that neuronal PTP1B deletion is able to partially protect mice from HCD-induced obesity but is not a critical mediator of HCD-induced infertility. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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21. Disruption of Hephaestin in the Placenta and Fetus Leads to Fetal Anemia
- Author
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Helman, Sheridan L, Frazer, David M, Anderson, Greg J., and Wilkins, Sarah J
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- 2022
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22. Team Building Through Team Video Games: Randomized Controlled Trial.
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Keith, Mark J., Dean, Douglas L., Gaskin, James, and Anderson, Greg
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VIDEO games ,TEAM building ,GAMIFICATION ,ORGANIZATION management ,RANDOMIZED controlled trials - Abstract
Background: Organizations of all types require the use of teams. Poor team member engagement costs billions of US dollars annually. Objective: This study aimed to explain how team building can be accomplished with team video gaming based on a team cohesion model enhanced by team flow theory. Methods: In this controlled experiment, teams were randomly assigned to a team video gaming treatment or a control treatment. Team productivity was measured during both pretreatment and posttreatment team tasks. After the pretest, teams who were involved in the team video gaming treatment competed against other teams by playing the Halo or Rock Band video game for 45 minutes. After the pretest, teams in the control treatment worked alone for 45 minutes. Then, all teams completed the posttest team activity. This same experimental protocol was conducted on 2 different team tasks. Results: For both tasks, teams in the team video gaming treatment increased their productivity significantly more (F1=8.760, P=.004) on the posttest task than teams in the control treatment. Our flow-based theoretical model explained team performance improvement more than twice as well (R²=40.6%) than prior related research (R²=18.5%). Conclusions: The focused immersion caused by team video gaming increased team performance while the enjoyment component of flow decreased team performance on the posttest. Both flow and team cohesion contributed to team performance, with flow contributing more than cohesion. Team video gaming did not increase team cohesion, so team video gaming effects are independent of cohesion. Team video gaming is a valid practical method for developing and improving newly formed teams. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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23. Humans Have Always Lived in a World of Many Worlds.
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Anderson, Greg
- Subjects
PARABLES ,HUMAN beings ,COLONIES - Published
- 2021
24. Truth Telling as an Element of Ethical Behaviour and Professional Commitment in Dentistry: A Case Study Assessing Non-Disclosure Action.
- Author
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Sadighpour, Leyla and Anderson, Greg S.
- Subjects
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NONDISCLOSURE , *TRUST , *DENTISTRY , *PROFESSIONAL employees , *BIOETHICS - Abstract
Being truthful with patients is a critical foundation of the doctorpatient relationship and is fundamental to development of trust. A professional commitment to truth telling may sometimes contradict other principles of bioethics, which may challenge decision-making for the doctor and/or the treatment team. Practitioners may fail to address all ethical or legal aspects of a case and therefore make inappropriate decisions. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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25. A Neuronal Circuit for Stress-induced Reproductive Suppression.
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Anderson, Greg M
- Subjects
NEURAL circuitry ,LUTEINIZING hormone releasing hormone - Published
- 2023
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26. Remembering Lawrie Powell 1934–2022.
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Farrell, Geoff, Crawford, Darrell, and Anderson, Greg
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IRON metabolism - Abstract
Lawrie and Margaret had five children, and he is survived by Elizabeth - herself a distinguished hepatologist, Mark, Martine and Christa. GLO:EUW/01nov22:jgh16031-gra-0001.jpg PHOTO (COLOR): . gl More than "Mr. Iron", Lawrie Powell was a Foundation Stone of Asia-Pacific Gastroenterology and Liver disease. Remembering Lawrie Powell 1934-2022. [Extracted from the article]
- Published
- 2022
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27. Multiple Leptin Signalling Pathways in the Control of Metabolism and Fertility: A Means to Different Ends?
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Evans, Maggie C., Lord, Rebecca A., and Anderson, Greg M.
- Subjects
METABOLIC regulation ,LEPTIN ,HOMEOSTASIS ,BODY weight ,OBESITY - Abstract
The adipocyte-derived 'satiety promoting' hormone, leptin, has been identified as a key central regulator of body weight and fertility, such that its absence leads to obesity and infertility. Plasma leptin levels reflect body adiposity, and therefore act as an 'adipostat', whereby low leptin levels reflect a state of low body adiposity (under-nutrition/starvation) and elevated leptin levels reflect a state of high body adiposity (over-nutrition/obesity). While genetic leptin deficiency is rare, obesity-related leptin resistance is becoming increasingly common. In the absence of adequate leptin sensitivity, leptin is unable to exert its 'anti-obesity' effects, thereby exacerbating obesity. Furthermore, extreme leptin resistance and consequent low or absent leptin signalling resembles a state of starvation and can thus lead to infertility. However, leptin resistance occurs on a spectrum, and it is possible to be resistant to leptin's metabolic effects while retaining leptin's permissive effects on fertility. This may be because leptin exerts its modulatory effects on energy homeostasis and reproductive function through discrete intracellular signalling pathways, and these pathways are differentially affected by the molecules that promote leptin resistance. This review discusses the potential mechanisms that enable leptin to exert differential control over metabolic and reproductive function in the contexts of healthy leptin signalling and of diet-induced leptin resistance. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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28. Your opinions, rants & raves.
- Author
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GRUNDEY, TIM, ANDERSON, GREG, and REMMES, DAN
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PODCASTING ,PRODUCT obsolescence ,ELECTROMAGNETIC radiation ,HEADPHONES - Abstract
To give Apple its due, it does release security updates for five years on phones, while many cheaper Android phones lose support after only two years. I recently listened to a tech podcast - Apple was mentioned several times as being one of the principal culprits in restricting customers from getting their electronics repaired. Apple makes it virtually impossible for you or a third party to replace a phone battery or screen. [Extracted from the article]
- Published
- 2021
29. The Novel Silver-Containing Antimicrobial Potentiates Aminoglycoside Activity Against Pseudomonas aeruginosa.
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Donkor GY, Anderson GM, Stadler M, Tawiah PO, Orellano CD, Edwards KA, and Dahl JU
- Abstract
The rapid dissemination of antibiotic resistance combined with the decline in the discovery of novel antibiotics represents a major challenge for infectious disease control that can only be mitigated by investments into novel treatment strategies. Alternative antimicrobials, including silver, have regained interest due to their diverse mechanisms of inhibiting microbial growth. One such example is AGXX®, a broad-spectrum silver containing antimicrobial that produces highly cytotoxic reactive oxygen species (ROS) to inflict extensive macromolecular damage. Due to connections identified between ROS production and antibiotic lethality, we hypothesized that AGXX® could potentially increase the activity of conventional antibiotics. Using the gram-negative pathogen Pseudomonas aeruginosa, we screened possible synergistic effects of AGXX® on several antibiotic classes. We found that the combination of AGXX® and aminoglycosides tested at sublethal concentrations led to a rapid exponential decrease in bacterial survival and restored sensitivity of a kanamycin-resistant strain. ROS production contributes significantly to the bactericidal effects of AGXX®/aminoglycoside treatments, which is dependent on oxygen availability and can be reduced by the addition of ROS scavengers. Additionally, P. aeruginosa strains deficient in ROS detoxifying/repair genes were more susceptible to AGXX®/aminoglycoside treatment. We further demonstrate that this synergistic interaction was associated with significant increase in outer and inner membrane permeability, resulting in increased antibiotic influx. Our study also revealed that AGXX®/aminoglycoside-mediated killing requires an active proton motive force across the bacterial membrane. Overall, our findings provide an understanding of cellular targets that could be inhibited to increase the activity of conventional antimicrobials.
- Published
- 2023
- Full Text
- View/download PDF
30. Central Irisin Signaling Is Required for Normal Timing of Puberty in Female Mice.
- Author
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Decourt C, Evans MC, Inglis MA, and Anderson GM
- Subjects
- Mice, Male, Female, Animals, Sexual Maturation physiology, Obesity metabolism, Body Weight, Transcription Factors metabolism, Muscle, Skeletal metabolism, Leptin metabolism, Fibronectins genetics, Fibronectins metabolism
- Abstract
Timing of puberty requires exquisite coordination of genes, hormones, and brain circuitry. An increasing level of body adiposity, signaled to the brain via the fat-derived hormone leptin, is recognized as a major factor controlling puberty onset. However, it is clear that leptin is not the only metabolic cue regulating puberty, and that developmental regulation of this process also involves tissues other than adipose, with muscle development potentially playing a role in the timing of puberty. The proteolytic processing of fibronectin type 3 domain-containing protein 5 (FNDC5) releases a hormone, irisin. Irisin is primarily produced by muscle and is released into circulation, where levels increase dramatically as puberty approaches. We investigated the effects of a global deletion of the Fndc5 gene on pubertal timing. The absence of irisin induced a delay in puberty onset in female knockout mice compared with controls, without affecting body weight or gonadotropin-releasing hormone (GnRH) neuronal density. We next treated pre-pubertal wild-type male and female mice with an irisin receptor antagonist, cilengitide, for 7 days and observed a delay in first estrus occurrence compared to vehicle-treated control mice. Male puberty timing was unaffected. Next, we deleted the irisin receptor (integrin subunit alpha V) in all forebrain neurons and found a delay in the occurrence of first estrus in knockout females compared to controls. Taken together, these data suggest irisin plays a role in the timing of puberty onset in female mice via a centrally mediated mechanism., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Endocrine Society.)
- Published
- 2022
- Full Text
- View/download PDF
31. Redox-Mediated Inactivation of the Transcriptional Repressor RcrR is Responsible for Uropathogenic Escherichia coli's Increased Resistance to Reactive Chlorine Species.
- Author
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Sultana S, Crompton ME, Meurer K, Jankiewicz O, Morales GH, Johnson C, Horbach E, Hoffmann KP, Kr P, Shah R, Anderson GM, Mortimer NT, Schmitz JE, Hadjifrangiskou M, Foti A, and Dahl JU
- Subjects
- Humans, Chlorine pharmacology, Chlorine metabolism, Hypochlorous Acid pharmacology, Escherichia, Oxidation-Reduction, Anti-Bacterial Agents pharmacology, Oxidants pharmacology, Disulfides metabolism, Uropathogenic Escherichia coli metabolism, Escherichia coli Proteins genetics, Escherichia coli Proteins metabolism, Urinary Tract Infections microbiology, Escherichia coli Infections microbiology
- Abstract
The ability to overcome stressful environments is critical for pathogen survival in the host. One challenge for bacteria is the exposure to reactive chlorine species (RCS), which are generated by innate immune cells as a critical part of the oxidative burst. Hypochlorous acid (HOCl) is the most potent antimicrobial RCS and is associated with extensive macromolecular damage in the phagocytized pathogen. However, bacteria have evolved defense strategies to alleviate the effects of HOCl-mediated damage. Among these are RCS-sensing transcriptional regulators that control the expression of HOCl-protective genes under non-stress and HOCl stress. Uropathogenic Escherichia coli (UPEC), the major causative agent of urinary tract infections (UTIs), is particularly exposed to infiltrating neutrophils during pathogenesis; however, their responses to and defenses from HOCl are still completely unexplored. Here, we present evidence that UPEC strains tolerate higher levels of HOCl and are better protected from neutrophil-mediated killing compared with other E. coli. Transcriptomic analysis of HOCl-stressed UPEC revealed the upregulation of an operon consisting of three genes, one of which encodes the transcriptional regulator RcrR. We identified RcrR as a HOCl-responsive transcriptional repressor, which, under non-stress conditions, is bound to the operator and represses the expression of its target genes. During HOCl exposure, however, the repressor forms reversible intermolecular disulfide bonds and dissociates from the DNA resulting in the derepression of the operon. Deletion of one of the target genes renders UPEC significantly more susceptible to HOCl and phagocytosis indicating that the HOCl-mediated induction of the regulon plays a major role for UPEC's HOCl resistance. IMPORTANCE How do pathogens deal with antimicrobial oxidants produced by the innate immune system during infection? Uropathogenic Escherichia coli (UPEC), the most common etiological agent of urinary tract infections (UTIs), is particularly exposed to infiltrating neutrophils and, therefore, must counter elevated levels of the antimicrobial oxidant HOCl to establish infection. Our study provides fundamentally new insights into a defense mechanism that enables UPEC to fend off the toxic effects of HOCl stress. Intriguingly, the defense system is predominantly found in UPEC and absent in noninvasive enteropathogenic E. coli. Our data suggest expression of the target gene rcrB is exclusively responsible for UPEC's increased HOCl tolerance in culture and contributes to UPEC's survival during phagocytosis. Thus, this novel HOCl stress defense system could potentially serve as an attractive drug target to increase the body's own capacity to fight UTIs.
- Published
- 2022
- Full Text
- View/download PDF
32. Fetal resorption coincides with dysregulated LH secretion in AMH-overexpressing mice.
- Author
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Zhou Y, Neyt C, Batchelor NJ, Kelley RL, Jaafar Amsak K, Anderson GM, Oorschot DE, Jasoni CL, Girling JE, and Pankhurst MW
- Subjects
- Animals, Embryo Transfer, Female, Fetal Resorption metabolism, Humans, Mice, Oocytes metabolism, Pregnancy, Abortion, Spontaneous metabolism, Anti-Mullerian Hormone genetics, Anti-Mullerian Hormone metabolism
- Abstract
Female anti-Müllerian hormone (AMH) overexpressing (Thy1.2-AMHTg/0) mice experience fetal resorption (miscarriage) by mid-gestation. This study examined whether the ovary, uterine implantation sites and hypothalamus are potential sites of AMH action, as AMH type-2 receptor (AMHR2) expression is reported in each tissue. Pregnancy in Thy1.2-AMHTg/0 mice was compared to wild-type (WT) mice via histological examination of implantation sites, hormone assays, embryo culture and embryo transfer. Uterine AMH and AMHR2 expression was examined by RT-qPCR and immunohistochemistry. The first signs of fetal resorption in the Thy1.2-AMHTg/0 dams occurred at embryonic day 9.5 (E9.5) with 100% of fetuses resorbing by E13.5. Cultured embryos from Thy1.2-AMHTg/0 dams had largely normal developmental rates but a small proportion experienced a minor developmental delay relative to embryos from WT dams. However, embryos transferred from WT donor females always failed to survive to term when transferred into Thy1.2-AMHTg/0 dams. Amh and Amhr2 mRNA was detected in the gravid uterus but at very low levels relative to expression in the ovaries. Progesterone and estradiol levels were not significantly different between WT and Thy1.2-AMHTg/0 dams during pregnancy but luteinizing hormone (LH) levels were significantly elevated in Thy1.2-AMHTg/0 dams at E9.5 and E13.5 relative to WT dams. Collectively, these experiments suggest that AMH overexpression does not cause fetal resorption through an effect on oocytes or preimplantation embryo development. The Thy1.2-AMHTg/0 fetal resorption phenotype is nearly identical to that of transgenic LH overexpression models, suggesting that neuroendocrine mechanisms may be involved in the cause of the miscarriage.
- Published
- 2022
- Full Text
- View/download PDF
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