Early Release Science of the exoplanet WASP-39b with JWST NIRSpec PRISM

Transmission spectroscopy1-3 of exoplanets has revealed signatures of water vapour, aerosols and alkali metals in a few dozen exoplanet atmospheres4,5. However, these previous inferences with the Hubble and Spitzer Space Telescopes were hindered by the observations' relatively narrow wavelength range and spectral resolving power, which precluded the unambiguous identification of other chemical species-in particular the primary carbon-bearing molecules6,7. Here we report a broad-wavelength 0.5-5.5 µm atmospheric transmission spectrum of WASP-39b8, a 1,200 K, roughly Saturn-mass, Jupiter-radius exoplanet, measured with the JWST NIRSpec's PRISM mode9 as part of the JWST Transiting Exoplanet Community Early Release Science Team Program10-12. We robustly detect several chemical species at high significance, including Na (19σ), H2O (33σ), CO2 (28σ) and CO (7σ). The non-detection of CH4, combined with a strong CO2 feature, favours atmospheric models with a super-solar atmospheric metallicity. An unanticipated absorption feature at 4 µm is best explained by SO2 (2.7σ), which could be a tracer of atmospheric photochemistry. These observations demonstrate JWST's sensitivity to a rich diversity of exoplanet compositions and chemical processes.

An unusual cause of food-induced anaphylaxis in mothers

BACKGROUND

Galacto-oligosaccharides (GOS) are prebiotics added to commercial milk formula of infants and mothers. In recent years, cases of allergy related to GOS in atopic children have been reported in the South East Asian region.

CASE PRESENTATIONS

We describe a series of pregnant (n = 4) and lactating mothers (n = 2) who developed anaphylactic reactions after consumption of maternal milk formula containing GOS. All six subjects had pre-existing atopy and a positive skin prick test to GOS and 5/5 of the subjects who were tested had positive basophil activation tests to GOS. All of the mothers and their babies had normal neonatal outcomes after the reactions.

CONCLUSIONS

The supplementation of GOS into milk and beverages in the Asian region should take into account the rare chance of allergenicity of GOS in the atopic population.

The endocrine disruptors dibutyl phthalate (DBP) and diethylstilbestrol (DES) influence Leydig cell regeneration following ethane dimethane sulphonate treatment of adult male rats

The manner by which endocrine-disrupting xenobiotics, such as phthalates, can induce changes in the development of the male reproductive system still remains largely unknown. Herein, we have explored the application of ethane dimethane sulphonate (EDS) to eliminate adult-type Leydig cells in the mature rat testis, leading to their regeneration from resident stem cells, as a novel system to investigate the effects of dibutyl phthalate (DBP) and diethylstilbestrol (DES) on adult-type Leydig cell differentiation. The advantage of this model is that one can study adult-type Leydig cell differentiation in vivo divorced from the concomitant endocrine development of puberty. In these preliminary studies, we show that both DBP and/or DES, given for 2 or 4 days following EDS application, indeed affect Leydig cell differentiation in the adult testis, largely by increasing early Leydig cell proliferation and possibly thereby delaying early differentiation. In particular, on day 27 post-EDS, a time-point when the differentiation trajectory appears to be most discriminating, we observe that both DBP and/or DES cause a fourfold increase in Leydig cell density, and a significant increase in the expression of the Leydig cell-specific marker transcripts INSL3, LH receptor, Cyp17a1 and Cyp 11a1. In conclusion, both DBP and DES are able to affect adult-type Leydig cells during their differentiation to cause a significant perturbation in their ultimate functional capacity.

141. DEVELOPMENT OF A MODEL SYSTEM TO ASSESS THE REGULATION OF LEYDIG STEM CELL DIFFERENTIATION

The Leydig cells of the testis are responsible for the production of ca. 95% of all circulating androgens in the adult male. There is substantial evidence now that loss of Leydig cell (LC) functionality may account in part for declining androgen levels in the ageing male. Some of this loss of functionality appears to be due to disruption of early LC differentiation processes caused by exposure to environmental endocrine disrupting substances. We have made use of the ability of the alkylating agent ethane dimethane sulfonate (EDS) to destroy specifically all immature and adult LC to develop a model system which allows us to quantitatively assess the differentiation of a new population of LC from resident stem cells in the testis. Following a single bolus injection of EDS into adult Sprague Dawley rats, unless additional testosterone is present to suppress the HPG axis, new LC redifferentiate from the resident stem cells in the testis. These are small spindle-shaped mesenchymal cells which are located in the peritubular region adjacent to the seminiferous tubules. In the absence of mature LC these mesenchymal cells differentiate first into LC progenitor cells, then immature LC, and finally into adult LC, following a precisely defined kinetic which can be mapped using quantitative RT-PCR for LC specific genes in whole testis samples. We are using this model to examine the effect of in vivo application of known environmental endocrine disrupting agents on LC differentiation, and hence their potential to cause long-term loss of LC functionality.

241. Relaxin and INSL3 receptors and their signaling in primary human myometrial cells

In model species such as the pig or rat, the ovarian peptide hormone relaxin is able to induce uterine quiescence, suppressing natural or oxytocin-induced contractility via a cAMP-dependent mechanism. This is not observed in humans. The present study investigated the ability of relaxin to activate adenylate cyclase in primary human myometrial smooth muscle cells from non-pregnant tissue obtained at hysterectomy. We show that relaxin is indeed able to stimulate the generation of cAMP, and it does this in a manner which is dependent upon the mediation of a tyrosine phosphorylation activity as has been shown by us earlier in the endometrium and THP-1 cells, though likely not involving PI3-kinase. Furthermore, we identified transcripts for the relaxin receptor RXFP1 (formerly LGR7) as full-length variants, though a minor splice variant missing exon 2 was also present in low amounts. Interestingly human myometrial cells also express transcripts encoding the full-length receptor, RXFP2 (formerly LGR8), for the closely related peptide hormone, INSL3. This receptor can also respond to relaxin at high concentration. However, this receptor does not appear to function by contributing to the cAMP production in human myometrial cells, nor does INSL3 act as a functional agonist or antagonist of relaxin action. In conclusion, therefore, the well known inability of relaxin to inhibit contractility in human myometrial cells appears to be due to uncoupling events downstream of cAMP generation. Research supported by NH&MRC project grant 349502.

35. Models that change: The study of gay identity development

Since the declassification of homosexuality as a mental disorder by the American Psychiatric Association in 1974, a large number of models of gay identity development have been proposed in the literature. This is unique because for the first time, more attention was paid to the process of developing a gay identity rather than theorizing about the etiologies of homosexuality. This paper reviews the changes in thought found in the literature describing how one comes to develop a gay identity. For the marginalized, identity development is generally described against a backdrop of stigma. Fortunately, our current society is very different from the hostile world that surrounded the APA in 1974: homosexuality is more tolerated and accepted, laws are less discriminatory, and gay role models are more abundant and accessible. As society has evolved, so too have its descriptive models. Shame and reluctance are found in Plumer’s (1975) and Lee’s (1977) models. Pride and activism appear in Hencken and O’Dowd’s (1977) and Cass’ (1979) models. Troiden (1989) mentions the fear of AIDS in his writings. Alderson’s (1998) model reflects a climate where religion, friends, and society can be catalysts in developing a positive identity. Taken together, these models are like time capsules containing clues as to the social conditions of the time. As the rate of social evolution accelerates, it is doubtful that any model regarding marginalized individuals will ever become definitive. For the case of homosexuality, if and when its stigma is removed, then the defining feature of gay identity development is also removed. It is possible that in its place will be a general model of sexual identity development, where homosexual and heterosexual paths diverge innocently and quietly in a society that does not value one over the other. Alderson K. The ecological model of gay male identity. The Canadian Journal of Human Sexuality 2003; 12(2):75-85. Cass V. Homosexual identity formation: A theoretical model. Journal of Homosexuality 1979; 4(3):219-35. Troiden R. The formation of homosexual identities. Journal of Homosexuality 1989; 17(1/2):43-73.