Publications by authors named "Francisco J Sanchez"

33 Publications

Deep brain stimulation of midbrain locomotor circuits in the freely moving pig.

Brain Stimul 2021 Feb 27;14(3):467-476. Epub 2021 Feb 27.

Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL, USA; The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA. Electronic address:

Background: Deep brain stimulation (DBS) of the mesencephalic locomotor region (MLR) has been studied as a therapeutic target in rodent models of stroke, parkinsonism, and spinal cord injury. Clinical DBS trials have targeted the closely related pedunculopontine nucleus in patients with Parkinson's disease as a therapy for gait dysfunction, with mixed reported outcomes. Recent studies suggest that optimizing the MLR target could improve its effectiveness.

Objective: We sought to determine if stereotaxic targeting and DBS in the midbrain of the pig, in a region anatomically similar to that previously identified as the MLR in other species, could initiate and modulate ongoing locomotion, as a step towards generating a large animal neuromodulation model of gait.

Methods: We implanted Medtronic 3389 electrodes into putative MLR structures in Yucatan micropigs to characterize the locomotor effects of acute DBS in this region, using EMG recordings, joint kinematics, and speed measurements on a manual treadmill.

Results: MLR DBS initiated and augmented locomotion in freely moving micropigs. Effective locomotor sites centered around the cuneiform nucleus and stimulation frequency controlled locomotor speed and stepping frequency. Off-target stimulation evoked defensive and aversive behaviors that precluded locomotion in the animals.

Conclusion: Pigs appear to have an MLR and can be used to model neuromodulation of this gait-promoting center. These results indicate that the pig is a useful model to guide future clinical studies for optimizing MLR DBS in cases of gait deficiencies associated with such conditions as Parkinson's disease, spinal cord injury, or stroke.
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http://dx.doi.org/10.1016/j.brs.2021.02.017DOI Listing
February 2021

Atrial Dyssynchrony Measured by Strain Echocardiography as a Marker of Proarrhythmic Remodeling and Oxidative Stress in Cardiac Surgery Patients.

Oxid Med Cell Longev 2020 30;2020:8895078. Epub 2020 Dec 30.

Department of Morphophysiology, School of Medicine, National University of Cuyo, Centro Universitario, Mendoza 5500, Argentina.

Aging leads to structural and electrophysiological changes that increase the risk of postoperative atrial arrhythmias; however, noninvasive preoperative markers of atrial proarrhythmic conditions are still needed. This study is aimed at assessing whether interatrial dyssynchrony determined using two-dimensional speckle tracking echocardiography relates to proarrhythmic structural and functional remodeling. A cohort of 45 patients in sinus rhythm referred for cardiac surgery was evaluated by echocardiography and surface electrocardiogram the day before the intervention. Transmembrane potential, connexin, and potassium channel distribution, inflammatory, and nitrooxidative markers were measured from right atrial tissue obtained from patients. A difference greater than 40 milliseconds between right and left atrial free wall contraction confirmed the presence of interatrial dyssynchrony in 21 patients. No difference in relation with age, previous diseases, and 2-dimensional echocardiographic findings as well as average values of global longitudinal right and left atrial strain were found between synchronic and dyssynchronic patients. Postoperative atrial fibrillation incidence increased from 8.3% in the synchronic group to 33.3% in the dyssynchronic ones. P wave duration showed no difference between groups. Action potentials from dyssynchronous patients decreased in amplitude, maximal rate of depolarization, and hyperpolarized. Duration at 30% of repolarization increased, being markedly shorter at 90% of repolarization. Only the dyssynchronous group showed early and delayed afterdepolarizations. Atrial tissue of dyssynchronous patients displayed lateralization of connexin 40 and increased connexin 43 expression and accumulation of tumor necrosis factor- in the intercalated disc. Tumor necrosis factor- did not colocalize, however, with lateralized connexin 40. Nitroxidative marks and K channels increased perivascularly and in myocytes. Our results demonstrate that, as compared to a traditional surface electrocardiogram, the novel noninvasive echocardiographic evaluation of interatrial dyssynchrony provides a better identification of nonaged-related proarrhythmic atrial remodeling with increased susceptibility to postoperative atrial fibrillation.
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http://dx.doi.org/10.1155/2020/8895078DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7787772PMC
December 2020

Population Averaged Stereotaxic T2w MRI Brain Template for the Adult Yucatan Micropig.

Front Neuroanat 2020 13;14:599701. Epub 2020 Nov 13.

Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL, United States.

Population averaged brain templates are an essential tool for imaging-based neuroscience research, providing investigators with information about the expected size and morphology of brain structures and the spatial relationships between them, within a demographic cross-section. This allows for a standardized comparison of neuroimaging data between subjects and provides neuroimaging software with a probabilistic framework upon which further processing and analysis can be based. Many different templates have been created to represent specific study populations and made publicly available for human and animal research. An increasingly studied animal model in the neurosciences that still lacks appropriate brain templates is the adult Yucatan micropig. In particular, T2-weighted templates are absent in this species as a whole. To address this need and provide a tool for neuroscientists wishing to pursue neuroimaging research in the adult micropig, we present the construction of population averaged ( = 16) T2-weighted MRI brain template for the adult Yucatan micropig. Additionally, we present initial analysis of T1-weighted ( = 3), and diffusion-weighted ( = 3) images through multimodal registration of these contrasts to our T2 template. The strategies used here may also be generalized to create similar templates for other study populations or species in need of template construction.
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http://dx.doi.org/10.3389/fnana.2020.599701DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7691581PMC
November 2020

A New Simplified Biplanar (0-90°) Fluoroscopic Puncture Technique for Percutaneous Nephrolithotomy. Reducing Fluoroscopy Without Ultrasound. Initial Experience and Outcomes.

Urology 2020 Jun 14;140:165-170. Epub 2020 Mar 14.

Urology Department, Fundación Puigvert, Universidad Autónoma de Barcelona, Barcelona, Spain.

Objective: To present our simplified biplanar fluoroscopic puncture technique, its reduction in the fluoroscopic screening time as well as outcomes and the initial experience for percutaneous nephrolithotomy.

Methods: We performed a retrospective review of 136 patients operated with our simplified 0-90° puncture technique for percutaneous nephrolithotomy between 2015 and 2018. All patients were classified by stone complexity with Guy´s nephrolithometric stone score. The stone-free rate was evaluated by nonenhanced computerized tomography, and residual stones were defined as fragments ≥2 mm. Complications were divided according to the Clavien-Dindo classification.

Results: One hundred and thirty-six patients were operated with our puncture technique; 121 patients were performed in supine and 15 in the prone position. Fifty-one were men, and 85 were women with an overall mean age of 44.36 ± 13.23 years. The overall stone-free rate was 62.5%, and 83.8 % after an ancillary procedure. The mean fluoroscopy screening time was 69.47 ± 7.1 and 6 ± 4.1 seconds for the total surgical procedure and the percutaneous puncture, respectively. Complications were present in 25.7%, and no grade IV and V complications were present.

Conclusion: Our first case series with the 0-90° simplified fluoroscopic puncture technique shows a similar stone-free rate and safety profile but a low fluoroscopic screening time compared to the most common previously reported fluoroscopic puncture techniques non-focused on low radiation protocols. Further studies are required to evaluate the reproducibility, external validation, and the learning curve of our simplified 0-90° technique.
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http://dx.doi.org/10.1016/j.urology.2020.03.002DOI Listing
June 2020

Activation of Brainstem Neurons During Mesencephalic Locomotor Region-Evoked Locomotion in the Cat.

Front Syst Neurosci 2019 14;13:69. Epub 2019 Nov 14.

The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, United States.

The distribution of locomotor-activated neurons in the brainstem of the cat was studied by c- immunohistochemistry in combination with antibody-based cellular phenotyping following electrical stimulation of the mesencephalic locomotor region (MLR) - the anatomical constituents of which remain debated today, primarily between the cuneiform (CnF) and the pedunculopontine tegmental nuclei (PPT). Effective MLR sites were co-extensive with the CnF nucleus. Animals subject to the locomotor task showed abundant labeling in the CnF, parabrachial nuclei of the subcuneiform region, periaqueductal gray, locus ceruleus (LC)/subceruleus (SubC), Kölliker-Fuse, magnocellular and lateral tegmental fields, raphe, and the parapyramidal region. Labeled neurons were more abundant on the side of stimulation. In some animals, -labeled cells were also observed in the ventral tegmental area, medial and intermediate vestibular nuclei, dorsal motor nucleus of the vagus, n. tractus solitarii, and retrofacial nucleus in the ventrolateral medulla. Many neurons in the reticular formation were innervated by serotonergic fibers. Numerous locomotor-activated neurons in the parabrachial nuclei and LC/SubC/Kölliker-Fuse were noradrenergic. Few cholinergic neurons within the PPT stained for . In the medulla, serotonergic neurons within the parapyramidal region and the nucleus raphe magnus were positive for . Control animals, not subject to locomotion, showed few -labeled neurons in these areas. The current study provides positive evidence for a role for the CnF in the initiation of locomotion while providing little evidence for the participation of the PPT. The results also show that MLR-evoked locomotion involves the parallel activation of reticular and monoaminergic neurons in the pons/medulla, and provides the anatomical and functional basis for spinal monoamine release during evoked locomotion. Lastly, the results indicate that vestibular, cardiovascular, and respiratory centers are centrally activated during MLR-evoked locomotion. Altogether, the results show a complex pattern of neuromodulatory influences of brainstem neurons by electrical activation of the MLR.
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http://dx.doi.org/10.3389/fnsys.2019.00069DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6868058PMC
November 2019

The Risks and Responsibilities of Conducting Research on Historically Marginalized Communities.

Arch Sex Behav 2019 08 5;48(6):1651-1653. Epub 2019 Jul 5.

Department of Educational, School, and Counseling Psychology, University of Missouri, Columbia, MO, 65203, USA.

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http://dx.doi.org/10.1007/s10508-019-01506-yDOI Listing
August 2019

Power and Privilege in the Field of Sexuality Research and Beyond.

Arch Sex Behav 2019 08 30;48(6):1639-1640. Epub 2019 May 30.

Department of Educational, School and Counseling Psychology, University of Missouri, Columbia, MO, 65203, USA.

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http://dx.doi.org/10.1007/s10508-019-01472-5DOI Listing
August 2019

Genetic Link Between Gender Dysphoria and Sex Hormone Signaling.

J Clin Endocrinol Metab 2019 02;104(2):390-396

Hudson Institute of Research, Melbourne, Victoria, Australia.

Context: There is a likely genetic component to gender dysphoria, but association study data have been equivocal.

Objective: We explored the specific hypothesis that gender dysphoria in transgender women is associated with variants in sex hormone-signaling genes responsible for undermasculinization and/or feminization.

Design: Subject-control analysis included 380 transgender women and 344 control male subjects. Associations and interactions were investigated between functional variants in 12 sex hormone-signaling genes and gender dysphoria in transgender women.

Setting: Patients were recruited from the Monash Gender Clinic, Monash Health, Melbourne, Australia, and the University of California, Los Angeles.

Patients: Caucasian (non-Latino) transgender women were recruited who received a diagnosis of transsexualism [Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV) or gender dysphoria (DSM-V)] pre- or postoperatively. Most were receiving hormone treatment at the time of recruitment.

Main Outcome Measured: Genomic DNA was genotyped for repeat length polymorphisms or single nucleotide polymorphisms.

Results: A significant association was identified between gender dysphoria and ERα, SRD5A2, and STS alleles, as well as ERα and SULT2A1 genotypes. Several allele combinations were also overrepresented in transgender women, most involving AR (namely, AR-ERβ, AR-PGR, AR-COMT, CYP17-SRD5A2). Overrepresented alleles and genotypes are proposed to undermasculinize/feminize on the basis of their reported effects in other disease contexts.

Conclusion: Gender dysphoria may have an oligogenic component, with several genes involved in sex hormone-signaling contributing.
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http://dx.doi.org/10.1210/jc.2018-01105DOI Listing
February 2019

Role of glutathione biosynthesis in endothelial dysfunction and fibrosis.

Redox Biol 2018 04 1;14:88-99. Epub 2017 Sep 1.

Department of Cell Biology and Immunology, Centro de Biología Molecular "Severo Ochoa", (CSIC-UAM), Madrid, Spain. Electronic address:

Glutathione (GSH) biosynthesis is essential for cellular redox homeostasis and antioxidant defense. The rate-limiting step requires glutamate-cysteine ligase (GCL), which is composed of the catalytic (GCLc) and the modulatory (GCLm) subunits. To evaluate the contribution of GCLc to endothelial function we generated an endothelial-specific Gclc haplo-insufficient mouse model (Gclc e/+ mice). In murine lung endothelial cells (MLEC) derived from these mice we observed a 50% reduction in GCLc levels compared to lung fibroblasts from the same mice. MLEC obtained from haplo-insufficient mice showed significant reduction in GSH levels as well as increased basal and stimulated ROS levels, reduced phosphorylation of eNOS (Ser 1177) and increased eNOS S-glutathionylation, compared to MLEC from wild type (WT) mice. Studies in mesenteric arteries demonstrated impaired endothelium-dependent vasodilation in Gclc(e/+) male mice, which was corrected by pre-incubation with GSH-ethyl-ester and BH. To study the contribution of endothelial GSH synthesis to renal fibrosis we employed the unilateral ureteral obstruction model in WT and Gclc(e/+) mice. We observed that obstructed kidneys from Gclc(e/+) mice exhibited increased deposition of fibrotic markers and reduced Nrf2 levels. We conclude that the preservation of endothelial GSH biosynthesis is not only critical for endothelial function but also in anti-fibrotic responses.
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http://dx.doi.org/10.1016/j.redox.2017.08.019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5596265PMC
April 2018

LFP Oscillations in the Mesencephalic Locomotor Region during Voluntary Locomotion.

Front Neural Circuits 2017 19;11:34. Epub 2017 May 19.

Department of Physiology, Spinal Cord Research Centre, University of ManitobaWinnipeg, MB, Canada.

Oscillatory rhythms in local field potentials (LFPs) are thought to coherently bind cooperating neuronal ensembles to produce behaviors, including locomotion. LFPs recorded from sites that trigger locomotion have been used as a basis for identification of appropriate targets for deep brain stimulation (DBS) to enhance locomotor recovery in patients with gait disorders. Theta band activity (6-12 Hz) is associated with locomotor activity in locomotion-inducing sites in the hypothalamus and in the hippocampus, but the LFPs that occur in the functionally defined mesencephalic locomotor region (MLR) during locomotion have not been determined. Here we record the oscillatory activity during treadmill locomotion in MLR sites effective for inducing locomotion with electrical stimulation in rats. The results show the presence of oscillatory theta rhythms in the LFPs recorded from the most effective MLR stimulus sites (at threshold ≤60 μA). Theta activity increased at the onset of locomotion, and its power was correlated with the speed of locomotion. In animals with higher thresholds (>60 μA), the correlation between locomotor speed and theta LFP oscillations was less robust. Changes in the gamma band (previously recorded in the pedunculopontine nucleus (PPN), thought to be a part of the MLR) were relatively small. Controlled locomotion was best achieved at 10-20 Hz frequencies of MLR stimulation. Our results indicate that theta and not delta or gamma band oscillation is a suitable biomarker for identifying the functional MLR sites.
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http://dx.doi.org/10.3389/fncir.2017.00034DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5437718PMC
February 2018

Transwomen and the Metabolic Syndrome: Is Orchiectomy Protective?

Transgend Health 2016 1;1(1):165-171. Epub 2016 Aug 1.

Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, California.

Male-to-female transsexual women or who undergo cross-sex hormone treatments experience increased health-related risks (e.g., increased rates of cardiovascular disease and premature death). Yet, the exact mechanism by which altering biochemistry leads to metabolic impairment remains unclear. While much attention has been paid to cross-sex hormone therapy, little is known about the metabolic risk associated with orchiectomy. To address the above limitation, we prospectively enrolled 12 transwomen: 4 who had undergone bi-lateral orchiectomy and 8 who had not. Both groups were using cross-sex hormones. Glucose tolerance was assessed using a standard 75g oral glucose tolerance test. Hepatic steatosis was assessed by H magnetic resonance spectroscopy. The amount of subcutaneous and visceral abdominal fat was determined from a single abdominal axial image at the level between the vertebral L2 and L3 bodies. Baseline venous fasting blood sampling was performed for measurement of hemoglobin A1c, glucose, insulin, sex hormones, and sex hormone binding globulin. The major novel findings were: (1) orchiectomy and cross-sex hormone therapy is associated with less hepatic steatosis and insulin resistance; (2) orchiectomy may be metabolically protective, and (3) circulating concentrations of sex hormones may be a major determinant of metabolic health in transwomen. To our knowledge, this is the first study to suggest an independent and protective role of orchiectomy on the metabolic health of transwomen.
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http://dx.doi.org/10.1089/trgh.2016.0016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5685281PMC
August 2016

The making of an octopus arm.

Evodevo 2015 7;6:19. Epub 2015 May 7.

Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy.

Background: Most of our current findings on appendage formation and patterning stem from studies on chordate and ecdysozoan model organisms. However, in order to fully understand the evolution of animal appendages, it is essential to include information on appendage development from lophotrochozoan representatives. Here, we examined the basic dynamics of the Octopus vulgaris arm's formation and differentiation - as a highly evolved member of the lophotrochozoan super phylum - with a special focus on the formation of the arm's musculature.

Results: The octopus arm forms during distinct phases, including an early outgrowth from an epithelial thickening, an elongation, and a late differentiation into mature tissue types. During early arm outgrowth, uniform proliferation leads to the formation of a rounded bulge, which subsequently elongates along its proximal-distal axis by means of actin-mediated epithelial cell changes. Further differentiation of all tissue layers is initiated but end-differentiation is postponed to post-hatching stages. Interestingly, muscle differentiation shows temporal differences in the formation of distinct muscle layers. Particularly, first myocytes appear in the area of the future transverse prior to the longitudinal muscle layer, even though the latter represents the more dominant muscle type at hatching stage. Sucker rudiments appear as small epithelial outgrowths with a mesodermal and ectodermal component on the oral part of the arm. During late differentiation stages, cell proliferation becomes localized to a distal arm region termed the growth zone of the arm.

Conclusions: O. vulgaris arm formation shows both, similarities to known model species as well as species-specific patterns of arm formation. Similarities include early uniform cell proliferation and actin-mediated cell dynamics, which lead to an elongation along the proximal-distal axis. Furthermore, the switch to an adult-like progressive distal growth mode during late differentiation stages is reminiscent of the vertebrate progress zone. However, tissue differentiation shows a species-specific delay, which is correlated to a paralarval pelagic phase after hatching and concomitant emerging behavioral modifications. By understanding the general dynamics of octopus arm formation, we established a basis for further studies on appendage patterning, growth, and differentiation in a representative of the lophotrochozoan super phylum.
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http://dx.doi.org/10.1186/s13227-015-0012-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4458049PMC
June 2015

On the validity of popular masculinity rating scales with gay men.

Arch Sex Behav 2014 Nov 6;43(8):1547-57. Epub 2014 Sep 6.

Department of Psychological and Quantitative Foundations, University of Iowa, Iowa City, IA, USA.

During the past decade, greater quantitative attention has been given to how gay men's lives are affected by traditional notions of masculinity. Consequently, it is important that masculinity-related measures that are often used in research are valid for use with gay men. This study examined the factor structures, loadings, and psychometric properties of three commonly used masculinity-related measures: the Gender Role Conflict Scale, the Conformity to Masculine Norms Inventory, and the Reference Group Identity Dependence Scale. Data were collected via an online survey of 920 self-identified gay men (M(age) = 32.48 years, SD = 11.73). Confirmatory factor analyses indicated that while the goodness of fit statistics did not always indicate the model fit, there were similar endorsements of items across the three masculinity scales and subscale factor loadings consistent with published studies using mostly heterosexual male samples. Implications for future masculinity scale research on gay men are discussed.
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http://dx.doi.org/10.1007/s10508-014-0363-6DOI Listing
November 2014

Hurdling over sex? Sport, science, and equity.

Arch Sex Behav 2014 Aug;43(6):1035-42

Institute for Society and Genetics, University of California Los Angeles, Los Angeles, CA, USA.

Between 1968 and 1999, the International Olympic Committee (IOC) required all female athletes to undergo genetic testing as part of its sex verification policy, under the assumption that it needed to prevent men from impersonating women and competing in female-only events. After critics convinced officials that genetic testing was scientifically and ethically flawed for this purpose, the IOC replaced the policy in 1999 with a system allowing for medical evaluations of an athlete's sex only in cases of "reasonable suspicion," but this system also created injustice for athletes and stoked international controversies. In 2011, the IOC adopted a new policy on female hyperandrogenism, which established an upper hormonal limit for athletes eligible to compete in women's sporting events. This new policy, however, still leaves important medical and ethical issues unaddressed. We review the history of sex verification policies and make specific recommendations on ways to improve justice for athletes within the bounds of the current hyperandrogenism policy, including suggestions to clarify the purpose of the policy, to ensure privacy and confidentiality, to gain informed consent, to promote psychological health, and to deploy equitable administration and eligibility standards for male and female athletes.
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http://dx.doi.org/10.1007/s10508-014-0332-0DOI Listing
August 2014

Feminized behavior and brain gene expression in a novel mouse model of Klinefelter Syndrome.

Arch Sex Behav 2014 Aug 13;43(6):1043-57. Epub 2014 Jun 13.

Department of Human Genetics, David Geffen School of Medicine at University of California, 695 Charles E. Young Dr. S, Gonda 5506, MC 708822, Los Angeles, CA, 90095-7088, USA.

Klinefelter Syndrome (KS) is the most common sex chromosome aneuploidy in men and is characterized by the presence of an additional X chromosome (XXY). In some Klinefelter males, certain traits may be feminized or shifted from the male-typical pattern towards a more female-typical one. Among them might be partner choice, one of the most sexually dimorphic traits in the animal kingdom. We investigated the extent of feminization in XXY male mice (XXYM) in partner preference and gene expression in the bed nucleus of the stria terminalis/preoptic area and the striatum in mice from the Sex Chromosome Trisomy model. We tested for partner preference using a three-chambered apparatus in which the test mouse was free to choose between stimulus animals of either sex. We found that partner preference in XXYM was feminized. These differences were likely due to interactions of the additional X chromosome with the Y. We also discovered genes that differed in expression in XXYM versus XYM. Some of these genes are feminized in their expression pattern. Lastly, we also identified genes that differed only between XXYM versus XYM and not XXM versus XYM. Genes that are both feminized and unique to XXYM versus XYM represent strong candidates for dissecting the molecular pathways responsible for phenotypes present in KS/XXYM but not XXM. In sum, our results demonstrated that investigating behavioral and molecular feminization in XXY males can provide crucial information about the pathophysiology of KS and may aid our understanding of sex differences in brain and behavior.
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http://dx.doi.org/10.1007/s10508-014-0316-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4371776PMC
August 2014

Increased Cortical Thickness in Male-to-Female Transsexualism.

J Behav Brain Sci 2012 Aug;2(3):357-362

Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, Los Angeles, CA, USA.

Background: The degree to which one identifies as male or female has a profound impact on one's life. Yet, there is a limited understanding of what contributes to this important characteristic termed . In order to reveal factors influencing gender identity, studies have focused on people who report strong feelings of being the opposite sex, such as male-to-female (MTF) transsexuals.

Method: To investigate potential neuroanatomical variations associated with transsexualism, we compared the regional thickness of the cerebral cortex between 24 MTF transsexuals who had not yet been treated with cross-sex hormones and 24 age-matched control males.

Results: Results revealed thicker cortices in MTF transsexuals, both within regions of the left hemisphere (i.e., frontal and orbito-frontal cortex, central sulcus, perisylvian regions, paracentral gyrus) and right hemisphere (i.e., pre-/post-central gyrus, parietal cortex, temporal cortex, precuneus, fusiform, lingual, and orbito-frontal gyrus).

Conclusion: These findings provide further evidence that brain anatomy is associated with gender identity, where measures in MTF transsexuals appear to be shifted away from gender-congruent men.
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http://dx.doi.org/10.4236/jbbs.2012.23040DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3665407PMC
August 2012

The new policy on hyperandrogenism in elite female athletes is not about "sex testing".

J Sex Res 2013 15;50(2):112-5. Epub 2013 Jan 15.

Department of Counseling Psychology, The University of Wisconsin-Madison.

In April 2011, the International Olympic Committee (IOC) and the International Association of Athletics Federations (IAAF) updated their regulations regarding elite female athletes with hyperandrogenism: Women whose testosterone levels crossed into the male range could not compete with other women unless it was shown that they are resistant to the effects of testosterone. Although the new rule is a marked improvement over past attempts to ensure that men were not trying to compete as women in elite competition, several criticisms have been leveled against the new regulations. Here we offer our reactions to claims that the new regulation promotes a sex-verification test, claims that intersex athletes will automatically be disqualified from competition, and proposals to either divide athletes based on variables beyond sex or completely eliminate sex groupings. Although elite sports can never achieve a perfectly level playing field, there should be parameters to which athletes must conform for a given sport. Yet elite athletes themselves should play a decisive role in what is best for their sport.
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http://dx.doi.org/10.1080/00224499.2012.752429DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3554857PMC
April 2014

The relationship between help-seeking attitudes and masculine norms among monozygotic male twins discordant for sexual orientation.

Health Psychol 2013 Jan 1;32(1):52-6. Epub 2012 Oct 1.

Center for Gender-Based Biology, and Department of Human Genetics, UCLA School of Medicine, USA.

Objective: In general, heterosexual men are less favorable to asking for help compared to women and gay men. This can be problematic if a man avoids professional help when he is experiencing significant psychological distress. Yet, it is unclear to what degree such attitudes among men are due to innate differences or social environments. Studying twins provides one avenue for teasing apart these relationships.

Method: We recruited 38 pairs of monozygotic male twins (Mage = 35.87 years, SD = 9.52) raised together and who were discordant for sexual orientation. They completed measures of psychological distress (Symptom Checklist-90-Revised), positive attitudes toward psychological help-seeking behavior, and emphasis with fulfilling traditional masculine norms.

Results: Contrary to predictions, the heterosexual twins expressed more symptoms of specific distress-hostility (r = .30), paranoid ideation (r = .26), and psychoticism (r = .24)-than their gay cotwins. As predicted, heterosexual men were less favorable to seeking help (r = .25) and expressed greater emphasis on masculine norms (r = .26) than their cotwins. Within each group of men, unique aspects of masculine norms were significantly related to attitudes toward psychological help-seeking behavior.

Conclusion: The findings lend credence to the hypothesis that social environments influence attitudes and behaviors that are stereotypically masculine and potentially detrimental to men's health.
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http://dx.doi.org/10.1037/a0029529DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4031032PMC
January 2013

"Straight-acting gays": the relationship between masculine consciousness, anti-effeminacy, and negative gay identity.

Arch Sex Behav 2012 Feb;41(1):111-9

Department of Human Genetics, Center for Society & Genetics, UCLA School of Medicine, 695 Charles Young Drive S, #5524, Los Angeles, CA 90097-7088, USA.

Some gay men are preoccupied with traditional notions of masculinity and express negative feelings towards effeminate behavior in gay men. Various scholars have speculated that such attitudes by gay men reflect internalized negative feelings about being gay. Thus, we sought to assess the importance of masculinity among gay men, to compare their ideal versus perceived masculinity-femininity, to ask how gay men assess masculinity, and to test whether masculine consciousness and anti-effeminacy could predict negative feelings about being gay. Results from an online survey of 751 gay men in the United States (MAge=32.64 years, SD=11.94) showed that the majority rated masculinity for themselves and in a same-sex partner as important, and they ideally wished that their behavior was more masculine (Cohen's d=.42) and less feminine (d=.42) than they perceived it to be. Furthermore, one's behavior was more important than how one looks when assessing masculinity. A multiple regression analysis showed that the degree to which they were preoccupied with masculinity and expressed anti-effeminacy accounted for 30% of the variance in negative feelings about being gay. These finding further support the idea that masculinity is an important construct for gay men and that masculine consciousness and anti-effeminacy are related to negative feelings about being gay.
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http://dx.doi.org/10.1007/s10508-012-9912-zDOI Listing
February 2012

Reproductive endocrinology: athletes' bodies, sexed bodies--intersexuality in athletics.

Nat Rev Endocrinol 2011 Nov 29;8(4):198-9. Epub 2011 Nov 29.

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http://dx.doi.org/10.1038/nrendo.2011.213DOI Listing
November 2011

The Subjective Experience of Social Class and Upward Mobility Among African American Men in Graduate School.

Psychol Men Masc 2011 Oct;12(4):368-382

UCLA School of Medicine.

We used Consensual Qualitative Research Methodology to analyze responses from 14 African American men (Mdn(Age) = 25 years-old) in graduate school at a predominantly-White university in the Midwestern region of the United Sates regarding how they acquired awareness of their social-class status; how social class was related to their sense of masculinity; how social class was related to race and skin tone; and the role that education and a romantic partner could play in upward mobility. School peers were the main source for their early awareness of social class. Many believed that discrimination maintains social class stratification that disadvantages racial minorities and that one's race will always trump any personal characteristics-including having light-complected skin and an advanced degree. Finally many overcame several obstacles during their educational career, and most believed that a romantic relationship with a woman from a privileged background could facilitate upward mobility. Psychological scientists and practitioners are encouraged to consider the role that social class plays when examining men's well-being.
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http://dx.doi.org/10.1037/a0024057DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3207495PMC
October 2011

An introduction to the 2011 National Multicultural Conference & Summit keynote addresses.

Cultur Divers Ethnic Minor Psychol 2011 Jul;17(3):227

Center for Society & Genetics, Center for Gender-Based Biology, UCLA School of Medicine, Los Angeles, CA, USA.

This article provides and introduction to the 2011 National Multicultural Conference & Summit Keynote Addresses. The authors explain that they chose to focus on the tension and possibilities within multicultural psychology at the seventh biennial National Multicultural Conference & Summit (NMCS), which was held on January 27-28, 2011, at The Westin-Seattle Hotel. During the 2-day conference, nearly 900 attendees engaged with one another and heard from experts in the field as we focused on the theme, "Unification through Diversity: Bridging Psychological Science & Practice in the Public Interest. Two key sets of presentations are highlighted.
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http://dx.doi.org/10.1037/a0023633DOI Listing
July 2011

Epigenetic predictor of age.

PLoS One 2011 22;6(6):e14821. Epub 2011 Jun 22.

Department of Human Genetics, University of California Los Angeles, Los Angeles, California, United States of America.

From the moment of conception, we begin to age. A decay of cellular structures, gene regulation, and DNA sequence ages cells and organisms. DNA methylation patterns change with increasing age and contribute to age related disease. Here we identify 88 sites in or near 80 genes for which the degree of cytosine methylation is significantly correlated with age in saliva of 34 male identical twin pairs between 21 and 55 years of age. Furthermore, we validated sites in the promoters of three genes and replicated our results in a general population sample of 31 males and 29 females between 18 and 70 years of age. The methylation of three sites--in the promoters of the EDARADD, TOM1L1, and NPTX2 genes--is linear with age over a range of five decades. Using just two cytosines from these loci, we built a regression model that explained 73% of the variance in age, and is able to predict the age of an individual with an average accuracy of 5.2 years. In forensic science, such a model could estimate the age of a person, based on a biological sample alone. Furthermore, a measurement of relevant sites in the genome could be a tool in routine medical screening to predict the risk of age-related diseases and to tailor interventions based on the epigenetic bio-age instead of the chronological age.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0014821PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3120753PMC
November 2011

Genes and brain sex differences.

Prog Brain Res 2010 ;186:65-76

Center for Society & Genetics, Center for Gender-Based Biology, & Department of Human Genetics, UCLA School of Medicine, Los Angeles, CA, USA.

Throughout development, numerous biological events occur that differentially affect males and females. Specifically, sex-determining genes that are triggered by the sex-chromosome complement initiate a series of events that determine an organism's sex and lead to the differentiation of the body in sex-specific ways. Such events contribute to many unique sex differences, including the susceptibility to different diseases. Although it was believed that sex hormones singularly differentiated the brain and body, there is emerging research showing that genes also play a direct role. In this chapter, we review this line of work and focus on the use of a unique mouse model that separates the effect of gonadal hormones and sex chromosomes. As genetic technology continues to advance, our understanding of the role that hormones and genes play in sex differences can be used to advance the physical and mental health of both men and women.
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http://dx.doi.org/10.1016/B978-0-444-53630-3.00005-1DOI Listing
April 2011

The genetics of sex differences in brain and behavior.

Front Neuroendocrinol 2011 Apr 15;32(2):227-46. Epub 2010 Oct 15.

David Geffen School of Medicine at UCLA, Gonda Center, Room 5506, 695 Charles Young Drive South, Los Angeles, CA 90095-7088, United States.

Biological differences between men and women contribute to many sex-specific illnesses and disorders. Historically, it was argued that such differences were largely, if not exclusively, due to gonadal hormone secretions. However, emerging research has shown that some differences are mediated by mechanisms other than the action of these hormone secretions and in particular by products of genes located on the X and Y chromosomes, which we refer to as direct genetic effects. This paper reviews the evidence for direct genetic effects in behavioral and brain sex differences. We highlight the 'four core genotypes' model and sex differences in the midbrain dopaminergic system, specifically focusing on the role of Sry. We also discuss novel research being done on unique populations including people attracted to the same sex and people with a cross-gender identity. As science continues to advance our understanding of biological sex differences, a new field is emerging that is aimed at better addressing the needs of both sexes: gender-based biology and medicine. Ultimately, the study of the biological basis for sex differences will improve healthcare for both men and women.
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http://dx.doi.org/10.1016/j.yfrne.2010.10.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3030621PMC
April 2011

Gender Role Conflict, Interest in Casual Sex, and Relationship Satisfaction Among Gay Men.

Psychol Men Masc 2009 Jul;10(3):237-243

Center for Gender-Based Biology and the Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles.

This study compared single (n = 129) and partnered gay men (n = 114) to determine if they differed in their concerns over traditional masculine roles and interest in casual sex, and to measure the relationship between concerns over masculine roles and interest in casual sex. Additionally, a regression model to predict relationship satisfaction was tested. Participants were recruited at two Southern California Gay Pride festivals. Group comparisons showed single men were more restrictive in their affectionate behavior with other men (effect-size r = .14) and were more interested in casual sex than partnered men (effect-size r = .13); and partnered men were more concerned with being successful, powerful, and competitive than single men (effect-size r = .20). Different masculine roles were predictive of interest in casual sex among the two groups of men. Finally, a hierarchical regression analysis found that interest in casual sex and the length of one's current relationship served as unique predictors of relationship satisfaction among the partnered gay men (Cohen's f(2) = .52).
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http://dx.doi.org/10.1037/a0016325DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2922761PMC
July 2009

Masculine Gender Role Conflict and Negative Feelings about Being Gay.

Prof Psychol Res Pr 2010 Apr;41(2):104-111

UCLA School of Medicine.

Professional psychologists who work with gay men have noted that traditional masculine ideals play a prominent role in the gay community whereby some endorse these traditional ideals and stigmatize effeminate behavior by other gay men. One hypothesis is that this behavior reflects negative feelings about being gay. This article examined this hypothesis by reporting the results of an online survey of 622 self-identified gay men. Participants completed the Gender Role Conflict Scale, Lesbian and Gay Identity Scale, the Social Desirability Scale, and questions related to the importance of masculinity. Results showed that most participants valued the public appearance of masculinity; and they ideally wished to be more masculine than they felt they were (Cohen's d = 0.42). A multiple regression analysis showed that the degree to which they valued masculinity and were concerned with violating masculine ideals was positively related with negative feelings about being gay (Cohen's f(2) = .67). These findings highlight the importance of exploring the role that masculine ideals play in gay client's lives given that negative feelings about oneself can adversely affect psychological well-being.
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http://dx.doi.org/10.1037/a0015805DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860327PMC
April 2010

Collective Self-Esteem as a Coping Resource for Male-to-Female Transsexuals.

J Couns Psychol 2009 Jan;56(1):202-209

UCLA School of Medicine.

The fear of experiencing discrimination often provokes symptoms of psychological distress. One coping resource is positive identification with one's social group-known as collective self-esteem. This preliminary study investigated whether collective self-esteem was related to fears regarding a transsexual identity and psychological distress among 53 self-identified male-to-female transsexuals (mean age = 50.79). Participants were recruited from transgender events held in Arizona and California. The majority (81%) reported living full-time as women (mean length of time living as a woman = 6.33 years). Negative feelings about the transsexual community and fears regarding the impact of a transsexual identity were positively related to psychological distress. A regression model revealed that the fear of how a transsexual identity would affect one's life was the best predictor of the severity of psychological distress. These results are consistent with findings from other historically marginalized groups whereby the stress of being stigmatized by society adversely affects mental health.
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http://dx.doi.org/10.1037/a0014573DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2743026PMC
January 2009

Regional gray matter variation in male-to-female transsexualism.

Neuroimage 2009 Jul 31;46(4):904-7. Epub 2009 Mar 31.

Department of Neurology, UCLA School of Medicine, Los Angeles, CA 90095-7334, USA.

Gender identity-one's sense of being a man or a woman-is a fundamental perception experienced by all individuals that extends beyond biological sex. Yet, what contributes to our sense of gender remains uncertain. Since individuals who identify as transsexual report strong feelings of being the opposite sex and a belief that their sexual characteristics do not reflect their true gender, they constitute an invaluable model to understand the biological underpinnings of gender identity. We analyzed MRI data of 24 male-to-female (MTF) transsexuals not yet treated with cross-sex hormones in order to determine whether gray matter volumes in MTF transsexuals more closely resemble people who share their biological sex (30 control men), or people who share their gender identity (30 control women). Results revealed that regional gray matter variation in MTF transsexuals is more similar to the pattern found in men than in women. However, MTF transsexuals show a significantly larger volume of regional gray matter in the right putamen compared to men. These findings provide new evidence that transsexualism is associated with distinct cerebral pattern, which supports the assumption that brain anatomy plays a role in gender identity.
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http://dx.doi.org/10.1016/j.neuroimage.2009.03.048DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2754583PMC
July 2009

Reported Effects of Masculine Ideals on Gay Men.

Psychol Men Masc 2009 Jan;10(1):73-87

Center for Gender-Based Biology and the Department of Human Genetics at the David Geffen School of Medicine at the University of California, Los Angeles.

This exploratory study used consensual qualitative research methodology (Hill et al., 2005) to analyze what gay men associate with masculinity and femininity, how they feel masculine ideals affect their self-image, and how masculine ideals affect their same-sex relationships. Written responses were collected from 547 self-identified gay men in the U.S. via an Internet-based survey. Findings supported previous reports that perceptions of gender roles among gay men appear based on masculine and feminine stereotypes. Additionally, more adverse versus positive effects on self-image and same-sex romantic relationships were reported including difficulty being emotional and affectionate, pressure to be physically attractive, and pressure to appear masculine in order to be accepted by society and to be seen as desirable by other gay men. While research on gay men's experience with masculinity continues, psychologists should consider the possible influence of traditional masculine ideals when conceptualizing their gay male clients.
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http://dx.doi.org/10.1037/a0013513DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2902177PMC
January 2009