Synthesis of aspartic acid and tyrosine by the fire blight pathogen Erwinia amylovora is not required for proliferation on apple flower stigmas or virulence in fruitlets.

Aims: The Gram-negative bacterium Erwinia amylovora (Ea) is the causal agent of fire blight, a devastating disease of apples and pears. In the fire blight disease cycle, Ea grows in different plant tissues, each presenting a distinct nutrient environment. Here, we investigate the ability of aspartate and tyrosine double auxotroph Ea lines to proliferate on apple flower stigma surfaces representing the epiphytic growth stage of Ea and in developing fruitlets representing one endophytic growth stage of Ea.

Unsupervised Exercise in Interstitial Lung Disease: A Delphi Study to Develop a Consensus Preparticipation Screening Tool for Lymphangioleiomyomatosis.

Background: Little research is available to provide practical guidance to health care providers for exercise preparticipation screening and referral of patients with interstitial lung diseases (ILDs), including lymphangioleiomyomatosis (LAM), to participate in remote, unsupervised exercise programs.

Research Question: What exercise preparticipation screening steps are essential to determine whether a patient with LAM is medically appropriate to participate in a remote, unsupervised exercise program?

Study Design And Methods: Sixteen experts in LAM and ILD participated in a two-round modified Delphi study, ranking their level of agreement for 10 statements related to unsupervised exercise training in LAM, with an a priori definition of consensus. Additionally, 60 patients with LAM completed a survey of the perceived risks and benefits of remote exercise training in LAM.

Effects of 5-Week Oral Acetazolamide on Incremental Cycling Exercise in Pulmonary Arterial and Chronic Thromboembolic Pulmonary Hypertension: A Randomized Placebo-Controlled, Double-Blinded, Crossover Trial.

Introduction: Acetazolamide (AZA) improves nocturnal and daytime blood oxygenation in patients with pulmonary vascular disease (PVD), defined as pulmonary arterial and distal chronic thromboembolic pulmonary hypertension (CTEPH), and may improve exercise performance.

Methods: We investigated the effect of 5 weeks of AZA (250 mg bid) versus placebo on maximal load during incremental cycling ramp exercise in patients with PVD studied in a randomized controlled, double-blind, crossover design, separated by > 2 weeks of washout.

Results: Twenty-five patients (12 pulmonary arterial hypertension, 13 CTEPH, 40% women, age 62 ± 15 years) completed the trial according to the protocol.

Oxygen Therapy Part 2 - Indications and Toxicity.

Oxygen Therapy Part 2: Indications and ToxicityWemple et al. continue their review of oxygen therapy, discussing the acute and chronic indications for oxygen and the delivery of supplemental oxygen (and its potential adverse effects and toxicity).

Oxygen Therapy Part 1 - History, Physiology, and Evaluation.

History, Physiology, and Evaluation of Oxygen TherapyOxygen is standard therapy for acute cardiopulmonary diseases, and long-term oxygen therapy is common in the outpatient setting. In part I of a two-part review, Wemple and colleagues discuss the physiology of tissue hypoxia, mechanisms of hypoxemia, and its clinical assessment.

Asymmetric and symmetric dimethylarginine in high altitude pulmonary hypertension (HAPH) and high altitude pulmonary edema (HAPE).

High altitude exposure may lead to high altitude pulmonary hypertension (HAPH) and high altitude pulmonary edema (HAPE). The pathophysiologic processes of both entities have been linked to decreased nitric oxide (NO) availability. We studied the effect of acute high altitude exposure on the plasma concentrations of asymmetric (ADMA) and symmetric dimethylarginine (SDMA), L-arginine, L-ornithine, and L-citrulline in two independent studies.

Effects of trientine and penicillamine on intestinal copper uptake: A mechanistic 64 Cu PET/CT study in healthy humans.

Background And Aims: Trientine (TRI) and D-penicillamine (PEN) are used to treat copper overload in Wilson disease. Their main mode of action is thought to be through the facilitation of urinary copper excretion. In a recent study, TRI was noninferior to PEN despite lower 24-hour urinary copper excretion than PEN.

Effects of tetrathiomolybdate on copper metabolism in healthy volunteers and in patients with Wilson disease.

Background & Aims: In Wilson disease (WD), copper accumulates in the liver and brain causing disease. Bis-choline tetrathiomolybdate (TTM) is a potent copper chelator that may be associated with a lower risk of inducing paradoxical neurological worsening than conventional therapy for neurologic WD. To better understand the mode of action of TTM, we investigated its effects on copper absorption and biliary excretion.

Association between self-reported falling risk and risk of hospitalization for patients with chronic obstructive pulmonary disease.

Rationale: The association between self-report falling risk in persons with COPD and hospitalization has not been previously explored.

Objective: To examine whether self-reported risk is associated with hospitalizations in patients with COPD.

Methods: A secondary analysis from a prospective observational cohort study of veterans with COPD.

Cognitive and Emotional Responses to Chronic Obstructive Pulmonary Disease Exacerbations and Patterns of Care Seeking.

Cognitive and emotional responses associated with care seeking for chronic obstructive pulmonary disease (COPD) exacerbations are not well understood. We sought to define care-seeking profiles based on whether and when U.S.

Predictors of Patient-reported and Pharmacy Refill Measures of Maintenance Inhaler Adherence in Veterans with Chronic Obstructive Pulmonary Disease.

Suboptimal adherence to inhaled medications in patients with chronic obstructive pulmonary disease (COPD) remains a challenge. To examine the sociodemographic and clinical characteristics and medication beliefs associated with adherence measured by self-report and pharmacy data. A cross-sectional analysis of data from a prospective observational cohort study of patients with COPD was completed.

A remote monitoring-enabled home exercise prescription for patients with interstitial lung disease at risk for exercise-induced desaturation.

Rationale: Alternatives to center-based pulmonary rehabilitation are needed to improve patient access to this important therapy. A critical challenge to overcome is how to maximize safety of unsupervised exercise for at-risk patients. We investigated if a novel remote monitoring-enabled mobile health (mHealth) program is safe, feasible, and effective for patients who experience exercise-induced hemoglobin desaturation.

Arterial Blood Gases and Acid-Base Regulation.

Disorders of acid-base status are common in the critically ill and prompt recognition is central to clinical decision making. The bicarbonate/carbon dioxide buffer system plays a pivotal role in maintaining acid-base homeostasis, and measurements of pH, PCO, and HCO are routinely used in the estimation of metabolic and respiratory disturbance severity. Hypoventilation and hyperventilation cause primary respiratory acidosis and primary respiratory alkalosis, respectively.

Effects of greater erythroid Cl/HCO transporter (band 3) expression on ventilation and gas exchange during exhaustive exercise.

Band 3 protein is a Cl/[Formula: see text] transporter on the red blood cell (RBC) surface with an important role in CO excretion. Greater band 3 expression by roughly 20% is found in people with the GP.Mur blood type.

Performance and reliability of two frequently used point-of-care blood gas analyzers at 423 and 4,559 m.

Background And Objectives: Blood gas analyzers (BGA) aid medical decision-making. Their specified performance criteria are based on sea level conditions. However, millions of people are living at high altitude (HA) where the performance of BGAs is poorly characterized.

The Impact of Acetazolamide and Methazolamide on Exercise Performance in Normoxia and Hypoxia.

Doherty, Connor J., Jou-Chung Chang, Benjamin P. Thompson, Erik R.

Flying to high-altitude destinations: Is the risk of acute mountain sickness greater?

Background: Altitude sojourns increasingly attract individuals of all ages and different health statuses due to the appeal of high-altitude destinations worldwide and easy access to air travel. The risk of acute mountain sickness (AMS) when flying to high-altitude destinations remains underemphasized. Thus, this review aims to evaluate the altitude-dependent AMS incidence depending on the mode of ascending, e.

Effect of 5 weeks of oral acetazolamide on patients with pulmonary vascular disease: A randomized, double-blind, cross-over trial.

Background: The carbonic anhydrase inhibitor acetazolamide stimulates ventilation through metabolic acidosis mediated by renal bicarbonate excretion. In animal models, acetazolamide attenuates acute hypoxia-induced pulmonary hypertension (PH), but its efficacy in treating patients with PH due to pulmonary vascular disease (PVD) is unknown.

Methods: 28 PVD patients (15 pulmonary arterial hypertension, 13 distal chronic thromboembolic PH), 13 women, mean±SD age 61.

An update on environment-induced pulmonary edema - "When the lungs leak under water and in thin air".

Acute pulmonary edema is a serious condition that may occur as a result of increased hydrostatic forces within the lung microvasculature or increased microvascular permeability. Heart failure or other cardiac or renal disease are common causes of cardiogenic pulmonary edema. However, pulmonary edema may even occur in young and healthy individuals when exposed to extreme environments, such as immersion in water or at high altitude.

The association between arterial-end-tidal carbon dioxide difference and outcomes after out-of-hospital cardiac arrest.

Aim: We sought to determine if the difference between PCO and ECO is associated with hospital mortality and neurologic outcome following out-of-hospital cardiac arrest (OHCA).

Methods: This was a retrospective cohort study of adult patients who achieved return of spontaneous circulation (ROSC) after OHCA over 3 years. The primary exposure was the PCO-ECO difference on hospital arrival.