Sex and gender as critical and distinct contributors to the human brain-gut-microbiome axis.

The brain-gut-microbiome axis (BGMA) is a pivotal contributor to human health. A large body of research, especially from animal models, has revealed bidirectional, causal relationships between the BGMA and sex. In particular, sex steroids appear to be affected by the BGMA, to influence the BGMA, and to moderate environmental effects on the BGMA. However, animal research on the relationship between sex and the BGMA has not translated well to human models. We contend that this is due in part to an oversimplified approach to sex: although BGMA researchers have traditionally approached sex as a unidimensional, dichotomous variable, it is in fact multidimensional and is comprised of both multi-categorical and continuous dimensions. We also contend that research on the BGMA in humans should approach gender as a variable that is distinct from sex and that gender may influence the BGMA through pathways that are independent from the effects of sex alone. Research practices that consider the complexity and distinctiveness of sex and gender in relation to the human BGMA will not only yield improved understanding of this consequential system, but will also enhance the development of treatments for adverse health outcomes with BGMA-related etiologies. We conclude with recommendations for the implementation of such practices.

Insight into the partial oxidation of propene: the reactions of 2-propen-1-ol on clean and O-covered Mo(110).

The reactions of 2-propen-1-ol (allyl alcohol) were studied on clean and O-covered Mo(110) to understand the effect of resonance stabilization and the presence of surface oxygen on reaction selectivity. Propene is the only gaseous hydrocarbon product evolved from allyl alcohol reaction on O-covered Mo(110). Water and dihydrogen are also produced, along with a small amount of adsorbed carbon. We estimated, using X-ray photoelectron spectroscopy, that approximately 70% of the 0.11 ML of 2-propen-1-ol that reacts forms propene. In contrast, the dominant reaction pathway on the clean surface is nonselective decomposition to adsorbed carbon and hydrogen, leading to a 23% selectivity for propene formation. On both clean and O-covered Mo(110), X-ray photoelectron spectroscopy and infrared spectroscopy identify allyloxy as the reaction intermediate yielding propene. These results are discussed in the context of propene oxidation and periodic trends in reactivity.

Leiomyosarcoma of the parotid gland: a case report and review of the literature.

BACKGROUND: A primary leiomyosarcoma of the parotid gland has been reported only three times in the English literature. This type of tumor represents an extremely rare group of salivary gland neoplasm. METHODS: A 44 year old man was initially seen with a 5 cm right parotid mass which was resected with a total parotidectomy, preserving the facial nerve. The patient had no palpable cervical lymph nodes. RESULTS: The majority of the specimen was made up of a relatively well demarcated tumor 5 cm in diameter. The tumor was noted to contain moderate to poorly differentiated primary leiomyosarcoma of the parotid. CONCLUSIONS: A primary leiomyosarcoma of the parotid gland is an extremely rare existing entity. A review of the literature reveals that primary leiomyosarcoma and other sarcomas of the major salivary glands may share similar histogenesis and biologic behavior with their soft tissue counterparts.