Bone calcification rate as a factor of craniofacial transformations in salmonid fish: Insights from an experiment with hormonal treatment of calcium metabolism.

Adaptation to different environments can be achieved by physiological shifts throughout development. Hormonal regulators shape the physiological and morphological traits of the evolving animals making them fit for the particular ecological surroundings. We hypothesized that the artificially induced hypersynthesis of calcitonin and parathyroid hormone mutually influencing calcium metabolism could affect bone formation during early ontogeny in fish imitating the heterochrony in craniofacial ossification in natural adaptive morphs.

Direct development of the catfish pectoral fin: An alternative pectoral fin pattern of teleosts.

Background: The study of the teleosts' pectoral fin development touches on many crucial issues of evolutionary biology, from the formation of local adaptations to the tetrapod limbs' origin. Teleosts' pectoral fin is considered a rather developmentally and anatomically conservative structure. It displays larval and adult stages differing in the skeletal and soft tissues' composition.

[Treatment of post-intensive care tracheal stenosis after previous covid-19 pneumonia].

Objective: To analyze postoperative outcomes and perioperative management of patients with post-intensive care tracheal stenosis and previous COVID-19 pneumonia.

Material And Methods: There were 8 patients with post-intensive care tracheal stenosis and previous COVID-19 pneumonia aged 34-61 years between January 2021 and April 2021. Lung damage CT-3 was observed in 2 (25%) patients, CT-4 - in 5 (62.

Natural toxic impact and thyroid signalling interplay orchestrates riverine adaptive divergence of salmonid fish.

Adaptive radiation in fishes has been actively investigated over the last decades. Along with numerous well-studied cases of lacustrine radiation, some examples of riverine sympatric divergence have been recently discovered. In contrast to the lakes, the riverine conditions do not provide evident stability in the ecological gradients.

[Circular resection of the thoracic trachea for MALT lymphoma in an 81-year-old patient].

A rare clinical observation of primary tracheal MALT lymphoma is reported and difficulties of differential diagnosis are discussed. Tracheal neoplasms are rare tumors and characterized by delayed diagnosis after clinical manifestation (tracheal stenosis and associated complications). These tumors often occur an advanced age patients that complicates examination and surgical treatment.