ABSTRACT
Abstract: Research indicates that hypoxic pulmonary hypertension (HPH) potentially stimulates the sympathetic nervous system, which may increase norepinephrine (NE) release and cause excessive Ca2+ influx into pulmonary artery smooth muscle cells (PASMCs), leading to calcium overload and abnormal PASMC proliferation, factors closely associated with pulmonary vascular remodeling (PVR). This study investigates the potential mechanisms underlying echinacoside (ECH) treatment in HPH. Method: In the in vitro experiment, NE-induced PASMCs were used to simulate HPH-induced PASMCs' calcium overload and abnormal proliferation. Postincubation with ECH, [Ca2+]cyt changes were detected using Fluo-4 AM. Flow cytometry was employed to ascertain ECH's inhibitory effect on PASMCs proliferation. For in vivo experiments, rats were exposed to a hypoxic and low-pressure oxygen environment to establish the HPH model. Post-ECH treatment, hematoxylin and eosin (HE) staining was conducted to assess PVR, and western blot analysis was used to examine protein expression in the lung tissues of the different groups. Results: ECH was observed to inhibit [Ca2+]cyt increase in NE-induced PASMCs in a concentration-dependent manner, effectively reducing abnormal cell proliferation. It also reduced the expression of Transient receptor potential channel (TRPC) 1 (TRPC1), TRPC4, TRPC6, and calmodulin in PASMCs. In vivo studies demonstrated that ECH lowered the expression of these proteins in lung tissues of HPH rats, significantly decreased mean pulmonary artery pressure, and mitigated PVR.
ABSTRACT
Generally, Cryptococcus initially infects the respiratory tract, but can spread, eventually crossing the blood-brain barrier (BBB) and causing meningitis or meningoencephalitis. Specifically, Cryptococcus invades the vascular endothelial cells of the BBB, from which it enters the brain. The main mechanisms through which Cryptococcus crosses the BBB are transcellular traversal, the paracellular pathway, and via Trojan horse. In this paper, the mechanisms by which Cryptococcus crosses the BBB were explained in detail. In addition to pathways of entry to the brain, this paper presents a discussion on some rare cryptococcal infections and provides some insights for future research directions.
ABSTRACT
BACKGROUND: High-flow nasal cannula (HFNC) oxygen therapy is essentially a constant-flow, noninvasive respiratory support system similar to a noninvasive ventilator operating in constant-flow mode. The clinical outcome of HFNC oxygen therapy is strongly associated with the pressure generated by high-flow gas and the patient's comfort level. This study was performed to explore the relevant factors affecting pressure and comfort of HFNC oxygen therapy in vivo. METHODS: Thirty-five healthy volunteers were enrolled in the trial. They underwent placement of nasal cannulas of various inner diameters (3, 4 or 5 mm) and treatment with different HFNC devices [HFT-300 (Weishengkang Medical Technology Co., Ltd., Jiangsu China) or H-80 M (BMC Medical Co., Ltd., Beijing China)],and the nasal airway pressure and comfort were assessed. Multiple linear regression was used to determine predictors of airway pressure. RESULTS: Multiple linear regression showed that the end-expiratory pressure was associated with the flow rate, sex, height, and cannula size. The end-expiratory pressure increased by 0.6 cmH2O per 1-mm increase in cannula diameter, decreased by 0.3 cmH2O per 10-cm increase in participant height (with a 0.35 cmH2O decrease for men), and increased by 1 cmH2O when the flow rate increased by 10 L/min (R2 = 0.75, P < 0.05 for all variables in model). In addition, the pressure generated by the H-80 M device was higher than that generated by the HFT-300 device (P < 0.05). Discomfort manifested as difficulty in expiration, and its severity increased as the cannula diameter increased; however there was no significant difference in comfort between the two HFNC devices (P > 0.05). CONCLUSION: In volunteers undergoing HFNC oxygen therapy, the nasal cannula diameter, flow rate, sex, height, and device model can affect the nasal airway pressure, and the nasal catheter diameter and flow rate can affect comfort. These factors should be given close attention in clinical practice. TRIAL REGISTRATION: ChiCTR2300068313 (date of first registration: 14 February 2023, https://www.chictr.org.cn ).
Subject(s)
Cannula , Oxygen Inhalation Therapy , Humans , Male , Catheters , Oxygen , VolunteersABSTRACT
In this report, we describe a 42-year-old man with dyspnea and recurrent hemoptysis who was diagnosed with cardiac angiosarcoma and multiple pulmonary metastases. Before visiting our hospital, he had been misdiagnosed with a lung infection. Bronchoscopy, multiple imaging methods, and extensive laboratory studies failed to identify a clear etiology. Cardiac magnetic resonance imaging and percutaneous lung biopsy revealed cardiac angiosarcoma with multiple pulmonary metastases. Cardiac angiosarcoma is extremely rare and diagnosis is difficult. Diffuse alveolar hemorrhage is not a common manifestation of pulmonary metastases of angiosarcoma and in patients with hemoptysis, clinicians should consider a malignant etiology that is not restricted to the lungs.