A structural magnetic resonance imaging study in transgender persons on cross-sex hormone therapy

&lt;b&gt;&lt;i&gt;Background:&lt;/i&gt;&lt;/b&gt; To date, research findings are inconsistent about whether the neuroanatomy in transgender persons resembles that of their natal sex or their gender identity. Moreover, few studies have examined the effects of long-term cross-sex hormonal treatment on neuroanatomy in this cohort. The purpose of the present study was to examine neuroanatomical differences in transgender persons after prolonged cross-sex hormone therapy. &lt;b&gt;&lt;i&gt;Methods:&lt;/i&gt;&lt;/b&gt; Eighteen transgender men (female-to-male), 17 transgender women (male-to-female), 30 nontransgender men (natal men), and 27 nontransgender women (natal women) completed a high-resolution structural magnetic resonance imaging scan at 3 T. Eligibility criteria for transgender persons were gender-affirming surgery and at least 2 years of cross-sex hormone therapy. Exclusion criteria for nontransgender persons were presence of psychiatric or neurological disorders. &lt;b&gt;&lt;i&gt;Results:&lt;/i&gt;&lt;/b&gt; The mean neuroanatomical volume for the amygdala, putamen, and corpus callosum differed between transgender women and natal women but not between transgender women and natal men. Differences between transgender men and natal men were found in several brain structures, including the medial temporal lobe structures and cerebellum. Differences between transgender men and natal women were found in the medial temporal lobe, nucleus accumbens, and 3rd ventricle. Sexual dimorphism between nontransgender men and women included larger cerebellar volumes and a smaller anterior corpus callosum in natal men than in natal women. The results remained stable after correcting for additional factors including age, total intracranial volume, anxiety, and depressive symptoms. &lt;b&gt;&lt;i&gt;Conclusions:&lt;/i&gt;&lt;/b&gt; Neuroanatomical differences were region specific between transgender persons and their natal sex as well as their gender identity, raising the possibility of a localized influence of sex hormones on neuroanatomy.</jats:p

Neural correlates of ostracism in transgender persons living according to their gender identity : a potential risk marker for psychopathology?

Background. Stigmatization in society carries a high risk for development of psychopathology. Transgender persons are at particularly high risk for such stigmatization and social rejection by others. However, the neural correlates of ostracism in this group have not been captured. Method. Twenty transgender men (TM, female-to-male) and 19 transgender women (TW, male-to-female) already living in their gender identity and 20 cisgender men (CM) and 20 cisgender women (CW) completed a cyberball task assessing both exclusion and re-inclusion during functional magnetic resonance imaging (fMRI). Results. During psychosocial stress between-group differences were found in the dorsal and ventral anterior cingulate cortex (ACC) and the inferior frontal gyrus (IFG). Patterns were consistent with sex assigned at birth, i.e. CW showed greater activation in dorsal ACC and IFG relative to CM and TW. During re-inclusion, transgender persons showed greater ventral ACC activity relative to CW, possibly indicating persistent feelings of exclusion. Functional connectivity analyses supported these findings but showed a particularly altered functional connectivity between ACC and lateral prefrontal cortex in TM, which may suggest reduced emotional regulation to the ostracism experience in this group. Depressive symptoms or hormonal levels were not associated with these findings. Conclusion. The results bear implications for the role of social exclusion in development of mental health problems in socially marginalized groups

Prevalence of gender nonconformity in Flanders, Belgium

Gender nonconformity refers to the extent to which a person’s gender identity, gender role and/or gender expression differs from the cultural norms prescribed for people of a particular sex, within a certain society and era. Most data on gender nonconformity focus on the prevalence of gender dysphoria (which also includes a distress factor) or on the number of legal sex changes. However, not every gender nonconforming individual experiences distress or applies for treatment. Population-based research on the broad spectrum of gender nonconformity is scarce and more information on the variance outside the gender binary is needed. This study aimed to examine the prevalence of gender incongruence (identifying stronger with the other sex than with the sex assigned at birth) and gender ambivalence (identifying equally with the other sex as with the sex assigned at birth) based on two population-based surveys, one of 1,832 Flemish persons and one of 2,472 sexual minority individuals in Flanders. In the general population, gender ambivalence was present in 2.2% of male and 1.9% of female participants, whereas gender incongruence was found in 0.7% of men and 0.6% of women. In sexual minority individuals, the prevalence of gender ambivalence and gender incongruence was 1.8% and 0.9% in men and 4.1% and 2.1% in women, respectively. With a current Flemish population of about 6 million, our results indicate a total of between 17,150 and 17,665 gender incongruent men and between 14,473 and 15,221 gender incongruent women in Flanders

Value and pitfalls in iodine fortification and supplementation in the 21st century

Although the number of iodine-deficient countries has been reduced by almost 50% over the last decade, it still remains a frequently misunderstood health problem. The most devastating effects of iodine deficiency occur during fetal development and childhood, periods in which sufficient iodine delivery remains critical. Besides the determination of thyroid size, the concentration of urinary iodine, serum thyroid-stimulating hormone and serum thyroglobulin are useful biomarkers to assess iodine status. Severe iodine deficiency is associated with neurological complications, cretinism, endemic goitre development, hypothyroidism, decreased fertility and increased infant mortality. The recommended iodine supplementation strategies are based on correction of iodine deficiency, close monitoring and evaluation of iodine administration, cooperation of the salt industry, training of local health care professionals and education of the population. Besides the multiple beneficial effects of supplementation, we present in this review a critical look at the possible side effects

Isolation and characterization of novel bacterial strains exhibiting ligninolytic potential

Background - To expand on the range of products which can be obtained from lignocellulosic biomass, the lignin component should be utilized as feedstock for value-added chemicals such as substituted aromatics, instead of being incinerated for heat and energy. Enzymes could provide an effective means for lignin depolymerization into products of interest. In this study, soil bacteria were isolated by enrichment on Kraft lignin and evaluated for their ligninolytic potential as a source of novel enzymes for waste lignin valorization. Results - Based on 16S rRNA gene sequencing and phenotypic characterization, the organisms were identified as Pandoraea norimbergensis LD001, Pseudomonas sp LD002 and Bacillus sp LD003. The ligninolytic capability of each of these isolates was assessed by growth on high-molecular weight and low-molecular weight lignin fractions, utilization of lignin-associated aromatic monomers and degradation of ligninolytic indicator dyes. Pandoraea norimbergensis LD001 and Pseudomonas sp. LD002 exhibited best growth on lignin fractions, but limited dye-decolourizing capacity. Bacillus sp. LD003, however, showed least efficient growth on lignin fractions but extensive dye-decolourizing capacity, with a particular preference for the recalcitrant phenothiazine dye class (Azure B, Methylene Blue and Toluidene Blue O). Conclusions - Bacillus sp. LD003 was selected as a promising source of novel types of ligninolytic enzymes. Our observations suggested that lignin mineralization and depolymerization are separate events which place additional challenges on the screening of ligninolytic microorganisms for specific ligninolytic enzymes.BT/BiotechnologyApplied Science

Transcriptome analysis of a phenol-producing Pseudomonas putida S12 construct: Genetic and physiological basis for improved production

The unknown genetic basis for improved phenol production by a recombinant Pseudomonas putida S12 derivative bearing the tpl (tyrosine-phenol lyase) gene was investigated via comparative transcriptomics, nucleotide sequence analysis, and targeted gene disruption. We show upregulation of tyrosine biosynthetic genes and possibly decreased biosynthesis of tryptophan caused by a mutation in the trpE gene as the genetic basis for the enhanced phenol production. In addition, several genes in degradation routes connected to the tyrosine biosynthetic pathway were upregulated. This either may be a side effect that negatively affects phenol production or may point to intracellular accumulation of tyrosine or its intermediates. A number of genes identified by the transcriptome analysis were selected for targeted disruption in P. putida S12TPL3. Physiological and biochemical examination of P. putida S12TPL3 and these mutants led to the conclusion that the metabolic flux toward tyrosine in P. putida S12TPL3 was improved to such an extent that the heterologous tyrosine-phenol lyase enzyme had become the rate-limiting step in phenol biosynthesis. Copyright © 2008, American Society for Microbiology. All Rights Reserved

Comparative transcriptomics and proteomics of p-hydroxybenzoate producing Pseudomonas putida S12: novel responses and implications for strain improvement

A transcriptomics and proteomics approach was employed to study the expression changes associated with p-hydroxybenzoate production by the engineered Pseudomonas putida strain S12palB1. To establish p-hydroxybenzoate production, phenylalanine-tyrosine ammonia lyase (pal/tal) was introduced to connect the tyrosine biosynthetic and p-coumarate degradation pathways. In agreement with the efficient p-hydroxybenzoate production, the tyrosine biosynthetic and p-coumarate catabolic pathways were upregulated. Also many transporters were differentially expressed, one of which—a previously uncharacterized multidrug efflux transporter with locus tags PP1271-PP1273—was found to be associated with p-hydroxybenzoate export. In addition to tyrosine biosynthesis, also tyrosine degradative pathways were upregulated. Eliminating the most prominent of these resulted in a 22% p-hydroxybenzoate yield improvement. Remarkably, the upregulation of genes contributing to p-hydroxybenzoate formation was much higher in glucose than in glycerol-cultured cells