Secondary Adrenal Insufficiency After COVID-19 Diagnosed by Insulin Tolerance Test and Corticotropin-Releasing Hormone Test.

Coronavirus disease 2019 (COVID-19) can affect multiple organs and systems, including the endocrine system. Its symptoms can last for months, resulting in post-COVID-19 conditions, among others. A small number of patients have central adrenal insufficiency (CAI) months after recovery from COVID-19; nevertheless, its pathogenesis has not been fully elucidated. The insulin tolerance test (ITT) is a gold standard test assessing the hypothalamic-pituitary-adrenal axis, and the corticotropin-releasing hormone (CRH) test is useful for differentiating CAI into secondary (pituitary) and tertiary (hypothalamic) adrenal insufficiency. We present a case of new-onset CAI in a young female patient who had no medical history other than COVID-19. Adrenocorticotropin hormone and cortisol responded poorly to both insulin-induced hypoglycemia and CRH administration. These findings suggest that the pituitary gland may be the primary site of hypothalamic-pituitary-adrenal dysfunction, although magnetic resonance imaging of the pituitary gland was unremarkable. To our knowledge, this is possibly the first and only case report of new-onset secondary adrenal insufficiency after recovery from COVID-19 in which the ITT and the CRH test were performed and highly suggestive for the pathogenesis of not only post-COVID-19 CAI but also post-COVID-19 conditions.

Role of PDK1 in skeletal muscle hypertrophy induced by mechanical load.

Phosphatidylinositol 3-kinase (PI3K) plays an important role in protein metabolism and cell growth. We here show that mice (M-PDK1KO mice) with skeletal muscle-specific deficiency of 3'-phosphoinositide-dependent kinase 1 (PDK1), a key component of PI3K signaling pathway, manifest a reduced skeletal muscle mass under the static condition as well as impairment of mechanical load-induced muscle hypertrophy. Whereas mechanical load-induced changes in gene expression were not affected, the phosphorylation of ribosomal protein S6 kinase (S6K) and S6 induced by mechanical load was attenuated in skeletal muscle of M-PDK1KO mice, suggesting that PDK1 regulates muscle hypertrophy not through changes in gene expression but through stimulation of kinase cascades such as the S6K-S6 axis, which plays a key role in protein synthesis. Administration of the ß2-adrenergic receptor (AR) agonist clenbuterol activated the S6K-S6 axis in skeletal muscle and induced muscle hypertrophy in mice. These effects of clenbuterol were attenuated in M-PDK1KO mice, and mechanical load-induced activation of the S6K-S6 axis and muscle hypertrophy were inhibited in mice with skeletal muscle-specific deficiency of ß2-AR. Our results suggest that PDK1 regulates skeletal muscle mass under the static condition and that it contributes to mechanical load-induced muscle hypertrophy, at least in part by mediating signaling from ß2-AR.

New Definitions of the Kilogram and the Mole: Paradigm Shift to the Definitions Based on Physical Constants.

The kilogram is the unit of mass and was defined in 1889 by the international prototype of the kilogram. The mole is the unit of amount of substance and was defined in 1960 by the number of atoms in 0.012 kg of 12C. These definitions were revised in May 2019. The new definitions of the kilogram and the mole are based on the Planck constant h and the Avogadro constant NA, respectively. The values of h and NA used in the new definitions were determined by summarizing measurement results of the two physical constants by several national metrology institutes around the world. In this review, the history of the two units and measurement technologies used to derive the new definitions are described. The effect of the revision on the development of new measurement technologies is also introduced.

40 GHz continuous, precise, and low power-loss laser frequency sweep using an electro-optic modulator.

We propose and demonstrate a novel technique for precisely and widely sweeping the frequency of a continuous-wave laser. One of the modulation sidebands of a slave laser generated with an electro-optic modulator is phase-locked to a master laser; in this situation, the slave carrier component can be swept by sweeping the modulation frequency. It does not require beat signal detection at varying and/or high frequency, thus providing a robust and reliable laser frequency sweep. Also, it requires neither a frequency comb for the sweep nor a large power loss. We successfully swept an 852 nm laser over 20 GHz; we confirmed that a second harmonic 426 nm laser could be continuously swept over 40 GHz.

A case of hypoglycemia due to illegitimate sexual enhancement medication.

Sexual enhancement medication presents a large market for counterfeit versions. We report here a case of hypoglycemia caused by an illicit sexual enhancement medication containing an extremely large amount of the sulfonylurea drug glibenclamide together with a moderate amount sildenafil citrate.