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Cortisol is the glucocorticoid and mineralocorticoid in teleost fishes and is regarded as the seawater-adapting horrrone. In marine fishes such as the summer flounder salt and water balance is maintained by drinking seawater and desalinating blood plasma by excreting salt through the chloride cells in the gills. The chloride cells are mitochondria-rich cells known to contain dense amounts of [Na.sup.+]/[K.sup.+]-ATPase, an enzyme important to salt excretion. In this study juvenile summer flounder maintained in 30 ppt (bay water), were transferred for 5 d to 5, 30, or 50 ppt salinity. Whole-body levels of cortisol were measured by RIA following extraction. Immunocytochemistry was used to localize the glucocorticoid-like receptor (GLR) and the enzyme [Na.sup.+]/[K.sup.+]-ATPase. Five days in 50 ppt, but not 5 ppt, elevated cortisol levels (P < 0.05). The GLR was found in the gills, stomach, intestine, and kidney tubules. In the gills it was most strongly present in the mitochondria-rich cells throughout the cytosol. In the stomach GLR had a strongly nuclear localization in the epithelium o: the gastric glands and the surface, but not the mucus neck cells of the gastric glands nor the mesenchyme. GLR was also present in the nucleus of many, but not all, epithelial cells of the intestine. [Na.sup.+]/[K.sup.+]-ATPase, as expected, was localized in the mitochondriarich cells of the gills and the basolateral surface of the epithelial cells in the kidney tubules and intestine; however, the stomach did not seem to contain appreciable [Na.sup.+]/[K.sup.+]-ATPase. The co-localization of the GLR and [Na.sup.+]/[K.sup.+]-ATPase in many tissues supports the direct regulatory role of cortisol in salt balance in this marine teleost fish. [Supported by an REU Supplement to NSF IBN-0220196]

Cortisol is a steroid hormone secreted in response to stress and known to be a seawater-adapting hormone in teleost fishes. RU486 is a synthetic glucocorticoid and progesterone receptor blocker. Our aim was to quantify the effects of exogenous cortisol and RU486, alone or together, on whole-body cortisol concentrations and to localize glucocorticoid-like receptor (GLR) and [Na.sup.+]/[K.sup.+]-ATPase using immunocytochemistry in juvenile summer flounder, which are marine teleosts and were held at 30 ppt. Flounder were immersed in cortisol (20 mM), RU486 (0.12 mM), cortisol and RU486, or the vehicle alone (control) for 5 days. Immersion in RU486, with or without cortisol, significantly elevated whole-body concentrations of cortisol, confirming uptake by indicating suppression of the negative feedback loop on the cortisol axis. Immunoreactive-GLR and [Na.sup.+]/[K.sup.+]-ATPase were evident in all treatment groups in the primary osmoregulatory tissues (gill, intestine, and kidney). The GLR was more cytoplasmic in the intestine of RU486-treated flounder, whereas in control and cortisol-treated flounder nuclear staining was more evident. Localization of the GLR in the intestine and gills further evidences a direct action of cortisol on the major osmoregulatory organs. The present study also adds to the ability to manipulate the cortisol axis and therefore to understand cortisols role. [Supported by an REU Supplement to NSF IBN-0220196]

The stomach is an important organ, both physiologically and ecologically. Little is known about the endocrine regulation of stomach organogenesis. However, in vertebrates in general, corticosteroids and thyroid hormones significantly regulate development. In summer flounder, Parafichthys dentatus, stomach organogenesis occurs at the end of the larval phase during metamorphosis. In the incipient stomach, the developmental progression of proliferation, morphogenesis, and cell differentiation is closely associated with sequential amplification of cortisol and thyroid hormone. As one step in determining if the action of cortisol is necessary prior to thyroid hormones action during stomach organogenesis, we examined the spatial and temporal pattern of immunoreactivity for the glucocorticoid-like receptor (GLR). The antiserum was raised against a synthetic peptide for human glucocorticoid receptor. A specific immunoreaction was seen in chloride cells of the gills, pseudobranch, intestine, kidney tubules, and stomach. In the fully differentiated stomach of post-metamorphic juveniles, there was strong GLR immunoreactivity specifically localized in the gastric epithelium and gastric glands. This strong immunoreaction was corroborated by northern blot analysis, in which mRNA expression was similar to that for ;fills and intestine. Most importantly, GLR immunoreactivity was observed in the incipient stomach at developmental stages as early as pro-metamorphosis (immediately prior to metamorphic stages), the time when whole-body cortisol concentrations peak, consistent with a role for cortisol in stomach organogenesis of summer flounder. [Supported by NSF IBN-0220196]

The transition between the laminar and turbulent flow regimes is traditionally addressed using the continuum formulation of the Navier-Stokes equations and dimensionless parameters such as the Reynolds number. However, a detailed understanding of the transition mechanisms has remained elusive. Theoretical approaches based on molecular and quantum mechanical models have been proposed but have yet to be thoroughly tested experimentally. In an effort to test a quantum-based model, specific apparatus and experiments have been designed to evaluate particular features of the laminar-turbulent transition. Hysteresis plots of flow versus differential pressure are used to examine the flow transition that occurs inside a tube with a divergent entrance. The hysteresis plots generated in these tests show several notable features and quantitative trends. The primary focus of this article is on the observed dependence of the laminar-turbulent transition behavior on the absolute pressure. Whereas the continuum-based model does not predict a pressure dependence of the laminar-turbulent transition, a molecular-based model indicates a pressure effect on the transition to turbulent flow. [ABSTRACT FROM AUTHOR]

In this article, the authors provide guidance for applicants to any subspecialty in the medical specialties matching program, with a particular focus on those seeking a match into a pulmonary or critical care medicine training program, or both. The preparation, application, interview, ranking, and match steps are used to discuss available literature that informs this process. Preparing a fellowship application is discussed in terms of personal career goals, and specific strategies are suggested that can help a candidate to assess a program's fit with those goals. In addition to review of recent data on virtual interviewing and interview questioning, the authors provide practical recommendations for candidates seeking to maximize their success in the current interview environment. Finally, key points about generating a rank order list are summarized. This resource will prove useful to any candidate pursuing medical subspecialty training in the current era., Competing Interests: Financial/Nonfinancial Disclosures None declared., (Copyright © 2024 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Background: Despite its widespread use, there are no direct studies comparing mini-bronchoalveolar lavage (mini-BAL) to bronchoscopic bronchoalveolar lavage (BAL) for diagnosing pneumonia in ventilated patients. The aim of this study was to perform a systematic review of studies comparing ventilated patients undergoing both bronchoscopic BAL and mini-BAL, to determine the mini-BAL's diagnostic accuracy. Methods: We conducted a systematic review searching the databases PubMed (MEDLINE), EMBASE, Cochrane Library, Scopus, and clinicaltrials.gov from inception until January 2022, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Search terms included variations on "pneumonia," "critical illness," and "mini-bronchoalveolar lavage." Article screening and data extraction were performed independently by 2 reviewers. Results: Our search yielded 4296 abstracts. This was narrowed to 6 studies in which each patient underwent both mini-BAL and bronchoscopic BAL in succession. Included patients had a mean APACHE II score of 20.02 ± 3.81 and 15.95 ± 11.46 ventilator days. The sensitivity of the mini-BAL for diagnosis of pneumonia was 0.90 (95% confidence interval [CI]: 0.778-1.000) and the specificity was 0.827 (95% CI: 0.716-0.938). Limitations included inconsistency in volume of saline instilled and heterogeneity in included patients Conclusion: This study is the first to compile data from multiple publications directly comparing the mini-BAL to bronchoscopic BAL for diagnosing pneumonia in ventilated patients. Our data demonstrate a high degree of both sensitivity and specificity of mini-BAL for the diagnosis of pneumonia in ventilated patients and indicate that mini-BAL could be considered as an acceptable alternative diagnostic study., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.