Evaluation of Electrocardiogram Parameters and Heart Rate Variability During Blood Pressure Elevation by Phenylephrine in Cirrhotic Rats.

Cirrhotic cardiomyopathy is a myocardial disease that may go undetected in the early stages due to peripheral vasodilatation. The aim of the study was to evaluate the electrocardiogram (ECG) and heart rate variability (HRV) after raising blood pressure by phenylephrine injection in rats with liver cirrhosis. Twenty male Sprague-Dawley rats were divided into the Sham and common bile duct ligation (CBDL) groups.

Demographic, clinical, and paraclinical features of patients operated with the diagnosis of acute descending necrotizing mediastinitis: a retrospective study in Southern Iran.

Introduction: Descending necrotizing mediastinitis (DNM) is a type of acute mediastinitis that is rarely reported but is regarded as a fatal disease despite improvements in technological methods and antibiotic therapies. We aimed to determine the demographic, clinical, and paraclinical features of patients diagnosed with acute DNM.

Methods: In this retrospective study, patients' hospital records with a diagnosis of DNM admitted to the Namazi hospital in southern Iran during 18 years (2002-2019) were reviewed.

The Validity of Heart Rate Variability Obtained from Electrocardiography and Blood Pressure in Rats Subjected to Isoproterenol-Induced Heart Ischemia.

Background: Heart rate variability (HRV) is calculated by electrocardiography (ECG-HRV) or blood pressure (BP-HRV). The purpose of this study was to determine the validity of the above methods in rats with normal and ischemic hearts during the baroreflex maneuver.

Methods: The study was conducted at Shiraz University of Medical Sciences, Shiraz, Iran, in 2021.

Therapeutic Approaches in COVID-19 Patients: The Role of the Renin-Angiotensin System.

Two and a half years after COVID-19 was first reported in China, thousands of people are still dying from the disease every day around the world. The condition is forcing physicians to adopt new treatment strategies while emphasizing continuation of vaccination programs. The renin-angiotensin system plays an important role in the development and progression of COVID-19 patients.

Roles of alpha-7 nicotinic acetylcholine receptors and spleen in the lung injury induced by a repeated saline lavage in rat.

Background: The study aimed to determine whether or notα7 nicotinic acetylcholine receptors (α7nAChR) induce anti-inflammatory effects directly in the lung or through the spleen pathway in a sterile model of lung injury by saline lavage.

Methods: Male Sprague Dawley rats were divided into seven groups; Sham, splenectomy (SPX), saline lavage (LAV), LAV treated with α7nAChR agonist nicotine (LAV + NIC), and LAV treated with NIC and a selective α7nAChR antagonist MLA (LAV+MLA+NIC), LAV and splenectomy (LAV+SPX), and LAV+SPX treated with nicotine (LAV+SPX+NIC). Tracheostomy and catheterization of the femoral artery were performed under deep anesthesia.

Fundamentals and Applications of Isolated Perfused Lung (IPL) Model in the Development of Pulmonary Drug Delivery.

Estimating parameters such as pulmonary drug disposition and deposited dose, as well as determining the influence of pulmonary pharmacokinetics (PK) on drug efficacy and safety, are critical factors for the development of inhaled drug products and help to achieve a better understanding of the drugs' fate in the lungs. Pulmonary disposition and PK have remained poorly understood due to the difficulty to access pulmonary fluids, compared to other biological fluids, such as plasma, for direct or surrogate measurement of the concentration of the active compounds and their metabolites in the lung. The use of the isolated perfused lung model (IPL) has become more common, and it is considered a useful tool to increase understanding in this area since it offers the possibility of controlling the administration and easier sampling of perfusate and lavage fluid.

The effect of suture techniques on the outcome of tracheal reconstruction: An observational study and review of literature.

Background: Tracheal resection and anastomosis surgery is a safe operation and is used to treat various benign and malignant diseases of the trachea. However, tracheal stenosis is among the main anastomotic complications following this procedure. Surgeons use both the continuous and the interrupted suture techniques for tracheal anastomosis, but contradicting results in each technique's complications have been reported in various studies.

The effect of subdiaphragmatic vagotomy on heart rate variability and lung inflammation in rats with severe hemorrhagic shock.

Background: The influence of cutting the sub-diaphragmatic branch of the vagus nerve on heart rate variability (HRV) and inflammatory reaction to severe hemorrhagic shock has not been determined prior to this study.

Methods: Male Sprague-Dawley rats were divided into four groups of Sham, sub-diaphragmatic vagotomized (Vag), subacute (135 ± 2 min) hemorrhagic shock (SHS), and sub-diaphragmatic vagotomized with SHS (Vag + SHS). Hemodynamic parameters were recorded and HRV calculated during multiple phases in a conscious model of hemorrhagic shock.

Vagotomy Improves Hypoxic Pulmonary Vasoconstriction in Rats Subjected to Brain Ischemia-Reperfusion Injury.

Background: Pulmonary dysfunction is one of the critical complications of a stroke. However, it remains unclear whether the mechanism is caused by either neurogenic or inflammatory reactions. The present study aimed to determine the effect of cerebral ischemia-reperfusion injury and the role of the vagus nerve on hypoxic pulmonary vasoconstriction (HPV) in rats.

Heart rate variability and pulmonary dysfunction in rats subjected to hemorrhagic shock.

Background: The activity of autonomic nervous system and its association with organ damage have not been entirely elucidated in hemorrhagic shock. The aim of this study was to investigate heart rate variability (HRV) and pulmonary gas exchange in hemorrhagic shock during unilateral subdiaphragmatic vagotomy.

Methods: Male Sprague Dawley rats were randomly assigned into groups of Sham, vagotomized (Vag), hemorrhagic shock (HS) and Vag + HS.

Roles of glutamate and GABA of the Kölliker-Fuse nucleus in generating the cardiovascular chemoreflex.

The Kölliker-Fuse (KF) nucleus is a part of the parabrachial complex, located in the dorsolateral pons. It is involved in the chemoreflex-evoked cardiovascular and respiratory changes, but the role of GABA and glutamate in cardiovascular chemoreflex has not been shown yet. This study was performed to determine the role of GABA, glutamate, and their interaction in the KF, in cardiovascular chemoreflex in anesthetized rat.

Lung injury in brain ischemia/reperfusion is exacerbated by mechanical ventilation with moderate tidal volume in rats.

Ischemic stroke is one of the most frequent causes of injury in the central nervous system which may lead to multiorgan dysfunction, including in the lung. The aim of this study was to investigate whether brain ischemia/reperfusion with or without mechanical ventilation leads to lung injury. Male Sprague-Dawley rats were assigned to four groups: Sham, 1-h brain ischemia (MCAO)/24-h reperfusion (I/R), mechanical ventilation with moderate tidal volume (MTV), and I/R+MTV.

Impact of liver damage on blood-borne variables and pulmonary hemodynamic responses to hypoxia and hyperoxia in anesthetized rats.

Background: Liver disorders may be associated with normal pulmonary hemodynamic, hepatopulmonary syndrome (HPS), or portopulmonary hypertension (POPH). In this study, we aimed to investigate the effect of the severity of liver dysfunctions on blood-borne variables, and pulmonary hemodynamic during repeated ventilation with hyperoxic and hypoxic gases.

Methods: Female Sprague Dawley rats were assigned into four groups of Sham (n = 7), portal vein ligation (PPVL, n = 7), common bile duct ligation (CBDL, n = 7), and combination of them (CBDL+ PPVL, n = 7).

Cardioprotective effects of curcumin and carvacrol in doxorubicin-treated rats: Stereological study.

Doxorubicin (DOX) is a cardiotoxic drug. To reduce the harmful effects of DOX, two plant-derived components, including curcumin (CUR) and carvacrol (CAR), were considered. This study aimed to assess the protective effects of CUR and CAR on DOX-induced cardiotoxicity using physiological and stereological evaluations.

Roles of Endothelin B Receptors and Endothelial Nitric Oxide Synthase in the Regulation of Pulmonary Hemodynamic in Cirrhotic Rats.

Introduction: Hepatopulmonary syndrome and portopulmonary hypertension are common complications of liver disorders. This study aimed to determine roles of ET-B receptors and endothelial-derived NO synthase in the regulation of pulmonary hemodynamic in cirrhotic rats.

Methods: Male Sprague-Dawley rats were divided into the Sham and common bile duct ligation (CBDL) groups.

The Interaction between Trolox and 4,4'-diisothiocyanatostilbene-2,2'-disulfonic Acid on Hypoxic Pulmonary Vasoconstriction in the Isolated Rabbit Lung.

Background: The mechanism of hypoxic pulmonary vasoconstriction (HPV) is still debatable. It has been proposed that reactive oxygen species (ROS) might be involved in HPV. However, there is no special transporter for superoxide anion in the cell membrane and it may release from the cells via anion exchanger.

Right ventricular pressure elevated in one-kidney, one clip Goldblatt hypertensive rats.

Both renal and respiratory diseases are common with high mortality rate around the world. This study was the first to compare effects of two kidneys, one clip (2K1C) and one-kidney, one clip (1K1C) Goldblatt hypertension on right ventricular pressure during normal condition and mechanical ventilation with hypoxia gas. Male Sprague-Dawley rats were subjected to control, 2K1C, or 1K1C groups.

Renal ischemia/reperfusion against nephrectomy for induction of acute lung injury in rats.

Purpose: Acute kidney injury (AKI) induces acute lung injury (ALI) through releasing injurious mediators or impairing clearance of systemic factors. To determine the links between AKI and ALI, pulmonary and blood variables were evaluated following induction of AKI via different experimental models of bilateral renal ischemia/reperfusion (BIR: renal ischemia with uremia), unilateral renal ischemia/reperfusion (UIR: renal ischemia without uremia), bilateral nephrectomy (BNX: uremia without renal ischemia), and unilateral nephrectomy (UNX: without uremia and renal ischemia).

Methods: Ninety male Sprague-Dawley rats were divided into six groups.

Distant effects of unilateral renal ischemia/reperfusion on contralateral kidney but not lung in rats: the roles of ROS and iNOS.

Acute kidney injury is usually associated with distant organ dysfunction. The roles of inducible nitric oxide synthase (iNOS) and reactive oxygen species (ROS) in this phenomenon were investigated following 2 h unilateral renal ischemia and 24 h reperfusion. There were 3 groups of rats subjected to either unilateral ischemia/reperfusion (UIR group), unilateral nephrectomy (UNX group), or sham operation.

The Effect of Blood Loss in the Presence and Absence of Severe Soft Tissue Injury on Hemodynamic and Metabolic Parameters; an Experimental study.

Introduction: The effect of severe soft tissue injury on the severity of hemorrhagic shock is still unknown. Therefore, the present study was aimed to determine hemodynamic and metabolic changes in traumatic/hemorrhagic shock in an animal model.

Methods: Forty male rats were randomly divided into 4 equal groups including sham, hemorrhagic shock, soft tissue injury, and hemorrhagic shock + soft tissue injury groups.

The role of anion exchanger on pulmonary vascular response to sustained alveolar hypoxia in the isolated perfused rabbit lung.

Background: Some respiratory diseases may induce alveolar hypoxia thereby hypoxic pulmonary vasoconstriction (HPV). However, the mechanisms of this physiologic phenomenon are not fully understood. This study was the first to investigate the role of anion exchanger in sustained HPV.

Sustained Hypoxic Pulmonary Vasoconstriction in the Isolated Perfused Rat Lung: Effect of α1-adrenergic Receptor Agonist.

Background: Alveolar hypoxia induces monophasic pulmonary vasoconstriction in vivo, biphasic vasoconstriction in the isolated pulmonary artery, and controversial responses in the isolated perfused lung. Pulmonary vascular responses to sustained alveolar hypoxia have not been addressed in the isolated perfused rat lung. In this study, we investigated the effect of sustained hypoxic ventilation on pulmonary artery pressure in the present of phenylephrine, an α1-receptor agonist, under the above condition.

On summary measure analysis of linear trend repeated measures data: performance comparison with two competing methods.

Background: The summary measure approach (SMA) is sometimes the only applicable tool for the analysis of repeated measurements in medical research, especially when the number of measurements is relatively large. This study aimed to describe techniques based on summary measures for the analysis of linear trend repeated measures data and then to compare performances of SMA, linear mixed model (LMM), and unstructured multivariate approach (UMA).

Methods: Practical guidelines based on the least squares regression slope and mean of response over time for each subject were provided to test time, group, and interaction effects.

Effects of hypercapnia and NO synthase inhibition in sustained hypoxic pulmonary vasoconstriction.

Background: Acute respiratory disorders may lead to sustained alveolar hypoxia with hypercapnia resulting in impaired pulmonary gas exchange. Hypoxic pulmonary vasoconstriction (HPV) optimizes gas exchange during local acute (0-30 min), as well as sustained (> 30 min) hypoxia by matching blood perfusion to alveolar ventilation. Hypercapnia with acidosis improves pulmonary gas exchange in repetitive conditions of acute hypoxia by potentiating HPV and preventing pulmonary endothelial dysfunction.