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Vignozzi L, Morelli A, Filippi S, Comeglio P, Chavalmane AK, Marchetta M, Toce M, Yehiely-Cohen R, Vannelli GB, Adorini L, Maggi M. Farnesoid X receptor activation improves erectile function in animal models of metabolic syndrome and diabetes. J Sex Med 2010; 8:57-77. [PMID: 20955313 DOI: 10.1111/j.1743-6109.2010.02073.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
INTRODUCTION The farnesoid X receptor (FXR) is critically involved in the regulation of the hepato-biliary system. Recent data suggest a role for FXR in modulating other metabolic pathways and vascular function. AIM To investigate whether long-term administration of the selective FXR agonist INT-747 ameliorates erectile function, we tested it in two animal models of metabolic derangements: a rabbit model of high-fat diet (HFD)-induced metabolic syndrome (MetS) and a rat model of streptozotocin (STZ)-induced type 1 diabetes. METHODS HFD rabbit or STZ rats with or without chronic INT-747 dosing (10 mg/kg/day for 12 weeks). INT-747 addition to rabbit penile smooth muscle cells (rpSMCs). MAIN OUTCOME MEASURE Effects of INT-747 on metabolic features and erectile function in animal models and clarification of mechanism of action in isolated cells. RESULTS INT-747 dosing normalized visceral adiposity and glucose intolerance in HFD rabbits. INT-747 increased penile FXR expression and partially restored endothelial nitric oxide synthase and dimethylarginine dimethylaminohydrolase 1 expression as well as impaired nitric oxide (NO)-dependent relaxation (improved responsiveness to acetylcholine and electrical field stimulation). INT-747 was also effective in regulating NO downstream events, as shown by increased sodium nitroprusside-induced relaxation. Because phosphodiesterase type 5 and protein kinase G (PKG) were unaltered by INT-747, we analyzed the calcium-sensitizing RhoA/ROCK pathway. HFD increased, and INT-747 normalized, RhoA membrane translocation/activation. RhoA/ROCK signaling inhibition by INT-747 was confirmed in rpSMCs by confocal microscopy, MYPT1-phosphorylation, cytoskeleton remodeling, cell migration, and smooth muscle-related genes expression. In STZ rats, FXR penile expression was not altered but was significantly upregulated by INT-747 dosing. In this model, INT-747 improved penile erection induced by electrical stimulation of cavernous nerve and hypersensitivity to intracavernous injection of a ROCK-inhibitor, Y-27632, without improving hyperglycemia. CONCLUSION In HFD rabbits, INT-747 dosing improved glucose sensitivity and MetS-associated erectile dysfunction, via upregulation of NO transmission and inhibition of RhoA/ROCK pathway. In STZ rats, INT-747 restored in vivo penile erection and sensitivity to ROCK inhibition, independently of effects on glycemia.
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Affiliation(s)
- Linda Vignozzi
- Sexual Medicine and Andrology Unit, Department of Clinical Physiopathology, University of Florence, Florence, Italy
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Gur S, Kadowitz PJ, Hellstrom WJ. A Protein Tyrosine Kinase Inhibitor, Imatinib Mesylate (Gleevec), Improves Erectile and Vascular Function Secondary to a Reduction of Hyperglycemia in Diabetic Rats. J Sex Med 2010; 7:3341-50. [DOI: 10.1111/j.1743-6109.2010.01922.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Waldkirch ES, Ückert S, Sigl K, Satzger I, Geismar U, Langnäse K, Richter K, Sohn M, Kuczyk MA, Hedlund P. Expression of cyclic AMP-dependent protein kinase isoforms in human cavernous arteries: functional significance and relation to phosphodiesterase type 4. J Sex Med 2010; 7:2104-2111. [PMID: 20487244 DOI: 10.1111/j.1743-6109.2010.01808.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION The cyclic adenosine monophosphate-dependent protein kinase (cAK) is considered a key protein in the control of smooth muscle tone in the cardiovascular system. There is evidence that erectile dysfunction might be linked to systemic vascular disorders and arterial insufficiency, subsequently resulting in structural changes in the penile tissue. The expression and significance of cAK in human cavernous arteries (HCA) have not been evaluated. AIMS To evaluate the expression of cAK isoforms in HCA and examine the role of cAK in the cyclic adenosine monophosphate (cAMP)- and cyclic guanosine monophosphate (cGMP)-mediated control of penile vascular smooth muscle. METHODS The expression and distribution of phosphodiesterase type 4 (PDE4) and cAK isoforms in sections of HCA were investigated by means of immunohistochemistry and Western blot analysis. The effects of the cAK inhibitor Rp-8-CPT-cAMPS on the relaxation of isolated preparations of HCA (diameter > 100 µm) induced by rolipram, sildenafil, tadalafil, and vardenafil were studied using the organ bath technique. MAIN OUTCOME MEASURES Investigate the expression of cAK in relation to α-actin and PDE4 in HCA and evaluate the effects of an inhibition of cAK on the relaxation induced by inhibitors of PDE4 and PDE5 of isolated penile arteries. RESULTS Immunosignals specific for cAKIα, IIα, and IIβ were observed within the wall of HCA. Double stainings revealed colocalization of cAK with α-actin and PDE4. The expression of cAK isoforms was confirmed by Western blot analysis. The reversion of tension induced by inhibitors of PDE4 and PDE5 of isolated penile vascular tissue were attenuated significantly by Rp-8-CPT-cAMPS. CONCLUSIONS Our results demonstrate the expression of cAK isoforms in the smooth musculature of HCA and its colocalization with PDE4. A significant role for cAK in the regulation mediated by cAMP and cGMP of vascular smooth muscle tone in HCA can also be assumed.
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Affiliation(s)
- Eginhard S Waldkirch
- Hannover Medical School-Division of Surgery, Department of Urology and Urological Oncology, Hannover, Germany
| | - Stefan Ückert
- Hannover Medical School-Division of Surgery, Department of Urology and Urological Oncology, Hannover, Germany.
| | | | - Imke Satzger
- Hannover Medical School-Department of Dermatology and Allergology, Hannover, Germany
| | | | - Kristina Langnäse
- Otto-von-Guericke-University, Faculty of Medicine-Institute for Biochemistry and Cell Biology, Magdeburg, Germany
| | - Karin Richter
- Otto-von-Guericke-University, Faculty of Medicine-Institute for Biochemistry and Cell Biology, Magdeburg, Germany
| | - Michael Sohn
- Frankfurter Diakonie-Kliniken, St. Markus Academic Hospital-Department of Urology, Frankfurt am Main, Germany
| | - Markus A Kuczyk
- Hannover Medical School-Division of Surgery, Department of Urology and Urological Oncology, Hannover, Germany
| | - Petter Hedlund
- University Vita Salute, Faculty of Medicine, San Raffaele Hospital-Department of Urology, Urological Research Institute, Milan, Italy
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Gratzke C, Angulo J, Chitaley K, Dai YT, Kim NN, Paick JS, Simonsen U, Uckert S, Wespes E, Andersson KE, Lue TF, Stief CG. Anatomy, physiology, and pathophysiology of erectile dysfunction. J Sex Med 2010; 7:445-75. [PMID: 20092448 DOI: 10.1111/j.1743-6109.2009.01624.x] [Citation(s) in RCA: 234] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
INTRODUCTION Significant scientific advances during the past 3 decades have deepened our understanding of the physiology and pathophysiology of penile erection. A critical evaluation of the current state of knowledge is essential to provide perspective for future research and development of new therapies. AIM To develop an evidence-based, state-of-the-art consensus report on the anatomy, physiology, and pathophysiology of erectile dysfunction (ED). METHODS Consensus process over a period of 16 months, representing the opinions of 12 experts from seven countries. MAIN OUTCOME MEASURE Expert opinion was based on the grading of scientific and evidence-based medical literature, internal committee discussion, public presentation, and debate. RESULTS ED occurs from multifaceted, complex mechanisms that can involve disruptions in neural, vascular, and hormonal signaling. Research on central neural regulation of penile erection is progressing rapidly with the identification of key neurotransmitters and the association of neural structures with both spinal and supraspinal pathways that regulate sexual function. In parallel to advances in cardiovascular physiology, the most extensive efforts in the physiology of penile erection have focused on elucidating mechanisms that regulate the functions of the endothelium and vascular smooth muscle of the corpus cavernosum. Major health concerns such as atherosclerosis, hyperlipidemia, hypertension, diabetes, and metabolic syndrome (MetS) have become well integrated into the investigation of ED. CONCLUSIONS Despite the efficacy of current therapies, they remain insufficient to address growing patient populations, such as those with diabetes and MetS. In addition, increasing awareness of the adverse side effects of commonly prescribed medications on sexual function provides a rationale for developing new treatment strategies that minimize the likelihood of causing sexual dysfunction. Many basic questions with regard to erectile function remain unanswered and further laboratory and clinical studies are necessary.
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Affiliation(s)
- Christian Gratzke
- Department of Urology, Ludwig-Maximilians-Universität, München, Germany
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Corona G, Boddi V, Balercia G, Rastrelli G, De Vita G, Sforza A, Forti G, Mannucci E, Maggi M. The Effect of Statin Therapy on Testosterone Levels in Subjects Consulting for Erectile Dysfunction. J Sex Med 2010; 7:1547-56. [DOI: 10.1111/j.1743-6109.2009.01698.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Zhao C, Chae HJ, Kim SH, Cui WS, Lee SW, Jeon JH, Park JK. A new perfusion model for studying erectile function. J Sex Med 2010; 7:1419-28. [PMID: 20059654 DOI: 10.1111/j.1743-6109.2009.01652.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
INTRODUCTION The present study introduces a newly devised in vitro penile perfusion model, which allows the measurement of changes in intracavernosum pressure (ICP), tension, and cyclic nucleotides in penile tissue in a one-step procedure. AIMS We compared the penile perfusion model with the classical penile strip chamber model to develop the new model. METHODS We investigated the role of nitric oxide-cyclic guanosine monophosphate pathway in both systems activated by acetylcholine or electrical field stimulation (EFS). We measured cGMP (cyclic guanosine monophosphate) in the penile corpus cavernosum smooth muscle in both systems and perfusates in the penile perfusion model. We determined ICP, tension, and cGMP simultaneously in penile perfusion model during the experiments. MAIN OUTCOME MEASURES Changes of tension and cGMP in both models, and of cGMP in perfusates and of ICP in penile perfusion model. RESULTS In both systems, acetylcholine relaxed the phenylephrine-precontracted penile corpus cavernosum smooth muscle in a concentration-dependent manner. EFS decreased the tension in both models and ICP in the penile perfusion model in a frequency-dependent manner. Pretreatment with atropine, Nomega nitro-L-arginine-methyl ester (L-NAME), and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) blocked the acetylcholine-induced decrease in the tension in both models and ICP in penile perfusion model. Acetylcholine increased cGMP levels in the perfusate of penile perfusion model and the changes were attenuated by tetrodotoxin (TTX), atropine, L-NAME and ODQ. EFS increased cGMP levels of the penile corpus cavernosum smooth muscle of both models and the changes were attenuated by TTX, atropine, L-NAME, and ODQ. CONCLUSION The results indicated that the responses of penile strip and perfused penile tissue to acetylcholine and EFS were very similar in both models in terms of tension and cGMP levels. Furthermore, the new model has more advantages over the classical penile strip chamber model in measuring intracavernosum metabolic changes and ICP without interruption of the procedure.
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Affiliation(s)
- Chen Zhao
- Department of Urology, Medical School, and Institute for Medical Sciences, Chonbuk National University, and Research Institute of Clinical Medicine and CTC for Medical Device of Chonbuk National University Hospital, Jeonju 561-712, Korea
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Abstract
Erectile dysfunction (ED) affects up to 50% of men between the ages of 40 and 70. Treatment with PDE-5 inhibitors is effective in the majority of men with ED. However, PDE-5 inhibitors are not effective when levels of nitric oxide (NO), the principle mediator of erection, are low. The pharmacologic actions of three new potential treatments for ED are discussed in this paper: (1) sGC stimulators/activators, (2) Rho-kinase inhibitors, and (3) sodium nitrite.
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Atorvastatin improves the response to sildenafil in hypercholesterolemic men with erectile dysfunction not initially responsive to sildenafil. Int J Impot Res 2009; 22:51-60. [DOI: 10.1038/ijir.2009.48] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Jin HR, Kim WJ, Song JS, Choi MJ, Piao S, Shin SH, Tumurbaatar M, Tuvshintur B, Nam MS, Ryu JK, Suh JK. Functional and morphologic characterizations of the diabetic mouse corpus cavernosum: comparison of a multiple low-dose and a single high-dose streptozotocin protocols. J Sex Med 2009; 6:3289-304. [PMID: 19732306 DOI: 10.1111/j.1743-6109.2009.01464.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION With the advent of genetically modified mice, it seems particularly advantageous to develop a mouse model of diabetic erectile dysfunction. AIM To establish a mouse model of type I diabetes by implementation of either multiple low-dose streptozotocin (STZ) protocol or single high-dose STZ protocol and to evaluate morphologic alterations in the cavernous tissue and subsequent derangements in penile hemodynamics in vivo. METHODS Eight-week-old C57BL/6J mice were divided into three groups: a control group, a group administered the multiple low-dose STZ protocol (50 mg/kg x 5 days), and a group administered the single high-dose STZ protocol (200 mg/kg). MAIN OUTCOME MEASURES After 8 weeks, erectile function was measured by electrical stimulation of the cavernous nerve. The penis was then harvested and stained with hydroethidine (in situ analysis of superoxide anion), TUNEL, or antibodies to nitrotyrosine (marker of peroxynitrite formation), PECAM-1, smooth muscle alpha-actin, and phospho-eNOS. Penis specimens from a separate group of animals were used for phospho-eNOS and eNOS western blot or cGMP determination. RESULTS Erectile function was significantly less in diabetic groups than in control group. The generation of superoxide anion and nitrotyrosine and the number of apoptotic cells in both cavernous endothelial and smooth muscle cells were significantly higher in diabetic groups than in control group. Cavernous tissue phospho-eNOS and cGMP expression and the number of endothelial and smooth muscle cells were lower in diabetic groups than in control group. Both diabetic models resulted in similar structural and functional derangements in the corpus cavernosum; however, the mortality rate was higher in mice receiving single high-dose of STZ than in those receiving multiple low-doses. CONCLUSION The mouse model of type I diabetes is useful and technically feasible for the study of the pathophysiologic mechanisms involved in diabetic erectile dysfunction.
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Affiliation(s)
- Hai-Rong Jin
- National Research Laboratory of Regenerative Sexual Medicine and Department of Urology, Inha University School of Medicine, Incheon, Korea
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Fibbi B, Filippi S, Morelli A, Vignozzi L, Silvestrini E, Chavalmane A, De Vita G, Marini M, Gacci M, Manieri C, Vannelli GB, Maggi M. Estrogens regulate humans and rabbit epididymal contractility through the RhoA/Rho-kinase pathway. J Sex Med 2009; 6:2173-86. [PMID: 19453906 DOI: 10.1111/j.1743-6109.2009.01282.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION We have previously demonstrated that oxytocin (OT) and endothelin-1 (ET-1) peripherally regulate epididymal motility in an estrogen-dependent way. Because RhoA/Rho-kinase (ROCK) pathway is a contractile effector downstream to both OT and ET-1 receptors, we hypothesized an estrogenic modulation of OT- and ET-1-induced contraction through the up-regulation of RhoA/ROCK signaling. AIM To evaluate the effect of changing endocrine milieu on RhoA/ROCK pathway in the epididymis. METHODS We induced a pharmacological hypogonadotropic hypogonadism in rabbits and replaced hypogonadal animals with different sex steroids (testosterone, T, or estradiol valerate, [E(2v)]). Effects of estrogen deprivation were also evaluated in rabbits chronically treated with the P450-aromatase inhibitor letrozole. An "in vitro" model of human epididymal smooth muscle cells was established and stimulated with sex hormones (72 hours). Protein and mRNA expression and functional activity of RhoA/ROCK signaling were studied by quantitative reverse transcriptase-polymerase chain reaction, immunohistochemistry, western blot analysis, cell migration and by "in vitro" contractility studies using the ROCK inhibitor Y-27632. MAIN OUTCOME MEASURES Effects of sex steroids on expression and functional activation of RhoA/ROCK signaling in rabbit epididymis and human epididymal smooth muscle cells. RESULTS The relaxant effect of Y-27632 on ET-1-pre-contracted epididymal strips was significantly reduced in hypogonadal rabbits, as well as in letrozole-treated animals. T supplementation normalized T plasma levels, but not Y-27632 epididymal strip sensitivity. E(2)v not only completely restored Y-27632 responsiveness but even amplified it, indicating an estrogenic up-regulation of RhoA/ROCK pathway. Accordingly, ROCK1 protein and gene expressions were strongly induced by E(2)v but not by T. The estrogen-induced up-regulation of RhoA/ROCK signaling was confirmed in human epididymal smooth muscle cells. CONCLUSIONS Our results suggest that estrogens regulate epididymal motility by increasing RhoA/ROCK signaling, and therefore calcium sensitivity, which tunes up responsiveness to contractile factors.
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Affiliation(s)
- Benedetta Fibbi
- Department of Clinical Physiopathology, University of Florence, Florence, Italy
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Morelli A, Filippi S, Sandner P, Fibbi B, Chavalmane AK, Silvestrini E, Sarchielli E, Vignozzi L, Gacci M, Carini M, Vannelli GB, Maggi M. Vardenafil modulates bladder contractility through cGMP-mediated inhibition of RhoA/Rho kinase signaling pathway in spontaneously hypertensive rats. J Sex Med 2009; 6:1594-1608. [PMID: 19473460 DOI: 10.1111/j.1743-6109.2009.01249.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Phosphodiesterase type 5 inhibitors (PDE5i), the most widely used drugs for erectile dysfunction, could also improve lower urinary tract symptoms, essentially due to overactive bladder (OAB), a condition hypothesized to be a result of an increased RhoA/Rho-kinase (ROCK) signaling. Phosphorylation/inactivation of RhoA by cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG) activity has been described in vascular smooth muscle. AIM The aim of this paper was to investigate whether vardenafil-induced cGMP accumulation reduces RhoA/ROCK signaling in bladder. METHODS Spontaneously hypertensive rats (SHRs), a strain genetically prone to develop OAB, were treated with vardenafil (10 mg/kg/day) for 2 weeks. Wistar-Kyoto rats (WKY) were used as control. In vitro experiments were performed in human bladder smooth muscle cells (hBCs). MAIN OUTCOME MEASURES Urodynamic parameters were registered in vivo in anesthetized WKY and SHRs. RhoA/ROCK activity in bladder was evaluated by molecular and functional studies in tissues and cells. RESULTS The intercontraction interval and bladder capacity, and were decreased in SHRs and restored by vardenafil. The in vitro relaxant effect of the ROCK inhibitor Y-27632 was higher in bladder strips from SHR than from WKY and reduced by vardenafil. Nomega-nitro-L-arginine-methyl-ester (a NO-synthase inhibitor, 40 mg/kg/day during the last week of the 2-week treatment with vardenafil) partially antagonized vardenafil effect on Y-27632 responsiveness. Vardenafil prevented RhoA membrane translocation/activation, decreased ROCK activity, and increased cGMP levels in vivo (rat) and in vitro (hBCs). Exposing hBCs to vardenafil increased Ser(188) RhoA phosphorylation, to the same extent as the PDE5-insensitive PKG agonist Sp-8-Br-PET-cGMP. Moreover, vardenafil inhibited several RhoA-dependent functions in hBCs, including smooth muscle gene transcription and endothelin-1-induced migration. These effects were reverted by the PKG inhibitor KT 5823, further suggesting a cGMP/PKG-dependency. In hBCs, vardenafil was active in the low nanomolar range. CONCLUSIONS This is the first study demonstrating that the effect of vardenafil on OAB could be partially determined by a cGMP-dependent RhoA/ROCK signaling inhibition.
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Affiliation(s)
- Annamaria Morelli
- Department of Clinical Physiopathology, University of Florence, Florence, Italy
| | - Sandra Filippi
- Department of Clinical Physiopathology, University of Florence, Florence, Italy
| | | | - Benedetta Fibbi
- Department of Clinical Physiopathology, University of Florence, Florence, Italy
| | | | - Enrico Silvestrini
- Department of Clinical Physiopathology, University of Florence, Florence, Italy
| | - Erica Sarchielli
- Department of Anatomy, Histology and Forensic Medicine, University of Florence, Florence, Italy
| | - Linda Vignozzi
- Department of Clinical Physiopathology, University of Florence, Florence, Italy
| | - Mauro Gacci
- Department of Urology, University of Florence, Florence, Italy
| | - Marco Carini
- Department of Urology, University of Florence, Florence, Italy
| | - Gabriella B Vannelli
- Department of Anatomy, Histology and Forensic Medicine, University of Florence, Florence, Italy
| | - Mario Maggi
- Department of Clinical Physiopathology, University of Florence, Florence, Italy;.
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