Obstructive sleep apnoea and perioperative medicine: a growing concern.

Obstructive sleep apnoea represents a sizable public health and economic burden. Owing to rising obesity rates, the prevalence of obstructive sleep apnoea is increasing, and it is a condition that is significantly underdiagnosed. Exacerbated by the COVID-19 pandemic, the backlog of elective surgeries is also sizable and growing.

Radiolabelled leucocytes in human pulmonary disease.

Introduction: Radionuclides for leucocyte kinetic studies have progressed from non-gamma emitting cell-labelling radionuclides through gamma emitting nuclides that allow imaging of leucocyte kinetics, to the next goal of positron emission tomography (PET).

Sources Of Data: Mostly the authors' own studies, following on from studies of the early pioneers.

Areas Of Controversy: From early imaging studies, it appeared that the majority of the marginated granulocyte pool was located in the lungs.

Use of 111-Indium-labeled autologous eosinophils to establish the in vivo kinetics of human eosinophils in healthy subjects.

Eosinophils are the major cellular effectors of allergic inflammation and represent an important therapeutic target. Although the genesis and activation of eosinophils have been extensively explored, little is known about their intravascular kinetics or physiological fate. This study was designed to determine the intravascular life span of eosinophils, their partitioning between circulating and marginated pools, and sites of disposal in healthy persons.

Quantification of neutrophil migration into the lungs of patients with chronic obstructive pulmonary disease.

Objective: To quantify neutrophil migration into the lungs of patients with chronic pulmonary obstructive disease (COPD).

Methods: Neutrophil loss via airways was assessed by dedicated whole-body counting 45 min, 24 h and 2, 4, 7 and 10 days after injection of very small activities of (111)In-labelled neutrophils in 12 healthy nonsmokers, 5 healthy smokers, 16 patients with COPD (of whom 7 were ex-smokers) and 10 patients with bronchiectasis. Lung accumulation of (99m)Tc-labelled neutrophils was assessed by sequential SPECT and Patlak analysis in six COPD patients and three healthy nonsmoking subjects.

Measuring whole-body neutrophil redistribution using a dedicated whole-body counter and ultra-low doses of 111Indium.

Background: There is increasing interest in the 'homing' of neutrophils to bone marrow. The aim of this study was to measure the whole-body redistribution of (111) In using a whole-body counter following the administration of ultra-small activities of (111) In-labelled neutrophils.

Methods: The detectors of a dedicated whole-body counter were fitted with lead collimators.

Does P-glycoprotein have a role in the lung clearances of inhaled 99mTc-sestamibi and 99mTc-tetrofosmin?

Objective: The clearance rate of inhaled 99mTc-sestamibi from the lungs of healthy nonsmoking individuals is much slower than would be expected from its physical properties. The clearance rate is even slower in healthy cigarette smokers. As 99mTc-sestamibi is a substrate for P-glycoprotein (P-gp), pulmonary P-gp may be influential in 99mTc-sestamibi clearance and may be upregulated in smokers.

Pulmonary elimination rate of inhaled 99mTc-sestamibi radioaerosol is delayed in healthy cigarette smokers.

What Is Already Known About This Subject: * Very little is known about the physiology of P-glycoprotein (P-gp) expression in the lungs. * Ex vivo evidence based on resected lung tissue suggests that pulmonary P-gp is upregulated by cigarette smoke, but there are no in vivo studies to date.

What This Study Adds: * The novel observation that healthy cigarette smokers have a delayed pulmonary elimination rate of inhaled (99m)Tc-sestamibi, a P-gp substrate, provides for the first time a potential method for quantifying functional pulmonary P-gp expression that may inform about drug therapy by inhalation as well as provide a non-invasive, quantitative, human biomarker for assessing P-gp modulators.

Healthy passive cigarette smokers have increased pulmonary alveolar permeability.

Question: Does passive smoking have a measurable effect on lung function in otherwise healthy subjects? There is current interest concerning passive smoking but no objective evidence showing that it has any impact on lung function.

Methods: The pulmonary clearance rate of (99m)Tc-DTPA was measured in 21 healthy volunteers after inhalation as a radio-aerosol and compared between healthy cigarette smokers, passive smokers and non-smokers. All volunteers had normal lung function.

Quantification of disease activity in patients undergoing leucocyte scintigraphy for suspected inflammatory bowel disease.

Purpose: Whole-body gamma camera counting is an alternative to faecal 111In collection for quantifying disease activity in inflammatory bowel disease (IBD) but requires administration of imaging activities of 111In. The aim of this study was to explore a dedicated whole-body counter which requires 20-fold less activity than gamma camera counting.

Methods: Thirty patients with known or suspected IBD received 99mTc-granulocytes (approximately 200 MBq) and 111In-granulocytes (approximately 0.