Incidence of smell and taste disorders and associated factors in patients with mild to moderate COVID-19

<b>Objectives:</b> To determine the incidence of smell and taste disorders in our health department and to analyse the factors that could be associated with these symptoms in patients with COVID-19. <br><b>Methods:</b> We conducted an observational descriptive study of all patients with COVID-19 in our health area diagnosed between 2020/03/10 and 2020/04/14. Factors related to smell and taste disorders were analysed. <br><b>Results:</b> A total of 126 patients, 63 women and 63 men, aged 16-80 years, were included. As many as 69 patients (62.7%) presented hyposmia, and 58 (46%) of them had anosmia. A total of 75 patients (59.5%) presented hypogeusia, and 57 (45.2%) of them had ageusia. The risk factors that were most commonly associated with these disorders were the female sex (adjusted odds ratio, aOR 2.43 for smell disorders and 2.44 for taste disorders), allergic rhinitis (aOR 3.34 for smell disorders) and a younger age. A protective factor was arterial hypertension (aOR 0.51 for smell disorders and 0.35 for taste disorders). A history of tonsillectomy was the risk factor for taste disorder (aOR 5.23). <br><b>Conclusion:</b> Our results indicate that these sensory disorders occurred more frequently in female patients and in young patients with mild to moderate COVID-19 infection who progressed with mild nasal congestion, posterior rhinorrhoea and without anterior rhinorrhoea. The recovery of taste occurred before the recovery of smell.

A cellular and molecular basis for the selective desmopressin-induced ACTH release in Cushing disease patients: key role of AVPR1b receptor and potential therapeutic implications

CONTEXT

Desmopressin is a synthetic agonist of vasopressin receptors (AVPRs). The desmopressin stimulation test is used in the diagnosis and postsurgery prognosis of Cushing disease (CD). However, the cellular and molecular mechanisms underlying the desmopressin-induced ACTH increase in patients with CD are poorly understood.

OBJECTIVE

The objectives of this study were to determine, for the first time, whether desmopressin acts directly and exclusively on pituitary corticotropinoma cells to stimulate ACTH expression/release and to elucidate the cellular and molecular mechanisms involved in desmopressin-induced ACTH increase in CD.

DESIGN

A total of 8 normal pituitaries (NPs), 23 corticotropinomas, 14 nonfunctioning pituitary adenomas, 17 somatotropinomas, and 3 prolactinomas were analyzed for AVPR expression by quantitative real-time RT-PCR. Primary cultures derived from corticotropinomas, nonfunctioning pituitary adenomas, somatotropinomas, prolactinomas, and NPs were treated with desmopressin, and ACTH secretion/expression, [Ca(2+)]i kinetics, and AVPR expression and/or proliferative response were evaluated. The relationship between AVPR expression and plasma adrenocorticotropin/cortisol levels obtained from desmopressin tests was assessed.

RESULTS

Desmopressin affects all functional parameters evaluated in corticotropinoma cells but not in NPs or other pituitary adenomas cells. These effects might be due to the dramatic elevation of AVPR1b expression levels found in corticotropinomas. In line with this notion, the use of an AVPR1b antagonist completely blocked desmopressin stimulatory effects. Remarkably, only AVPR1b expression was positively correlated with elevated plasma adrenocorticotropin levels in corticotropinomas.

CONCLUSIONS

The present results provide a cellular and molecular basis to support the desmopressin stimulation test as a reliable, specific test for the diagnosis and postsurgery prognosis of CD. Furthermore, our data indicate that AVPR1b is responsible for the direct/exclusive desmopressin stimulatory pituitary effects observed in CD, thus opening the possibility of exploring AVPR1b antagonists as potential therapeutic tools for CD treatment.

Immunohistochemical localization of acid-sensing ion channel 2 (ASIC2) in cutaneous Meissner and Pacinian corpuscles of Macaca fascicularis

Acid-sensing ion channel 2 (ASIC2) is a member of the degenerin/epithelial sodium channel superfamily, presumably involved mechanosensation. Expression of ASIC2 has been detected in mechanosensory neurons as well as in both axons and Schwann-like cells of cutaneous mechanoreceptors. In these studies we analysed expression of ASIC2 in the cutaneous sensory corpuscles of Macaca fascicularis using immunohistochemistry and laser confocal-scanner microscopy. ASIC2 immunoreactivity was detected in both Meissner and Pacinian corpuscles. It was found to co-localize with neuron-specific enolase and RT-97, but not with S100 protein, demonstrating that ASIC2 expression is restricted to axons supplying mechanoreceptors. These results demonstrate for the first time the presence of the protein ASIC2 in cutaneous rapidly adapting low-threshold mechanoreceptors of monkey, suggesting a role of this ion channel in touch sense.