Eur J Clin Pharmacol
November 2024
Purpose: The shape and position of the hemoglobin-oxygen dissociation curve (ODC) is of critical importance in medicine, as it determines the uptake of O in the lungs and the delivery of O to the tissues. Numerous reports have identified affinity-modulating effects of drugs in humans. Such effects may be relevant to conditions such as pulmonary diffusion disorders, peripheral vascular disease, or coronary artery disease.
View Article and Find Full Text PDFBackground: Reamputations are frequent after minor amputations performed for diabetic foot osteomyelitis (DFO). Whether the type of amputation is associated with a particular outcome is unknown. The aim of this study was to evaluate whether amputations of the transarticular compared with the transosseous type have different rates of clinical and microbiological failure.
View Article and Find Full Text PDFBackground: Hemoglobin‑oxygen (Hb-O) affinity is an important determinant for oxygen delivery and oxygen extraction. Although cardiovascular agents such as noradrenaline, adrenaline, atropine, milrinone and levosimendan are widely used in intensive care units worldwide, nothing is known about their possible effects on Hb-O affinity.
Methods: In this experimental ex-vivo trial, venous blood samples were taken from 5 male and 6 female volunteers and incubated with the particular cardiovascular agents.
The affinity of hemoglobin (Hb) to oxygen (O) influences processes of oxygen delivery and extraction at the tissue level. Despite cannabinoids being utilized or ingested in various ways, their possible impact on Hb-O affinity has barely been studied. This is an experimental ex-vivo trial.
View Article and Find Full Text PDFDesflurane, isoflurane and sevoflurane, three halogenated ethers, are commonly used inhaled anesthetics, both in the operating room and in the intensive care unit (ICU). The potency and dosage of these drugs is expressed by the MAC value (minimum alveolar concentration). Their interaction with hemoglobin and its affinity for oxygen, best described by the oxygen dissociation curve (ODC), has already been investigated, with conflicting results.
View Article and Find Full Text PDFAm J Physiol Lung Cell Mol Physiol
June 2022
Inhalational prostacyclins act as strong vasodilators, potentially improving oxygenation by reducing shunt fraction and ventilation-perfusion mismatch. As prostacyclin receptors are known to be present on human erythrocytes, possible direct effects on hemoglobin oxygen transport were further explored by examining the sole in vitro influence of prostacyclins on hemoglobin oxygen (Hb-O) affinity. Venous blood samples from 20 healthy volunteers were exposed in vitro to supramaximal doses of epoprostenol, iloprost, and compared with control.
View Article and Find Full Text PDFCompletely avalanche-buried patients are frequently exposed to a combination of hypoxia and hypercapnia with a risk of normothermic cardiac arrest. Patients with a long burial time and an air pocket are exposed to a combination of hypoxia, hypercapnia, and hypothermia which may lead to the development of the "triple H syndrome". This specific combination has several pathophysiological implications, particularly on the cardiovascular system and oxygen transport (oxygen supply and oxygen consumption).
View Article and Find Full Text PDF5-Hydroxymethylfurfural (5-HMF) is known to increase hemoglobin oxygen affinity (Hb-O affinity) and to induce a left shift of the oxygen dissociation curve (ODC). It is under investigation as a therapeutic agent in sickle cell anemia and in conditions where pulmonary oxygen uptake is deteriorated or limited (e.g.
View Article and Find Full Text PDFOccult periprosthetic fractures have been defined as a fracture only visible on postoperative CT scans but not on postoperative plain radiography after an uneventful surgery without intraoperative fracture. The fracture rate for hemispherical and peripheral self-locking cups has been described as 8.4%.
View Article and Find Full Text PDFBMC Musculoskelet Disord
August 2021
Background: Several hip and knee pathologies are associated with aberrant femoral torsion. Diagnostic workup includes computed tomography (CT) and magnetic resonance imaging (MRI). For three-dimensional (3D) analysis of complex deformities it would be desirable to measure femoral torsion from MRI data to avoid ionizing radiation of CT in a young patient population.
View Article and Find Full Text PDFIn vitro determination of the hemoglobin oxygen dissociation curve (ODC) requires highly elaborate, specialized, and costly technical equipment. In addition, there is a lack of methods that combine reliable ODC recordings with high throughput in small blood samples for routine analysis. We here introduce a modified, commercial 96-well plate with an integrated unidirectional gas flow system specifically adapted for use in fluorescence microplate readers.
View Article and Find Full Text PDFBackground: Treatment of posterior shoulder instability (PSI) associated with excessive glenoid retroversion is a rare, challenging problem in shoulder surgery. One proposed technique is posterior open wedge glenoid osteotomy to correct excessive glenoid retroversion as described by Scott. However, this operation is rarely performed, and limited long-term outcomes using this approach are available.
View Article and Find Full Text PDFBackground: Atraumatic posterior shoulder instability in patients with pathologic glenoid retroversion and dysplasia is an unsolved problem in shoulder surgery.
Questions/purposes: In a preliminary study of a small group of patients with atraumatic posterior shoulder instability associated with glenoid retroversion ≥ 15° and glenoid dysplasia who underwent posterior open-wedge osteotomy and glenoid concavity reconstruction using an implant-free, J-shaped iliac crest bone graft, we asked: (1) What proportion of the patients had persistent apprehension? (2) What were the improvements in patient-reported shoulder scores? (3) What were the radiographic findings at short-term follow-up?
Methods: Between 2016 and 2018, we treated seven patients for atraumatic posterior shoulder instability. We performed this intervention when posterior shoulder instability symptoms were unresponsive to physiotherapy for at least 6 months and when it was associated with glenoid retroversion ≥ 15° and dysplasia of the posteroinferior glenoid.
Monocytes are important players to combat the ubiquitously present fungus Recruitment of monocytes to sites of fungal infection has been shown in vivo. Upon exposure to in vitro, purified murine and human blood monocytes secrete inflammatory cytokines and fungicidal mediators. Mononuclear tissue phagocytes are phenotypically and functionally different from those circulating in the blood and their role in antifungal defenses is much less understood.
View Article and Find Full Text PDFAccumulation of senescent cells promotes the development of age-related pathologies and deterioration. In human skin, senescent cells potentially impair structure and function by secreting a mixture of signaling molecules and proteases that influence neighboring cells and degrade extracellular matrix components, such as elastin and collagen. One of the key underlying mechanisms of senescence and extrinsic skin aging is the increase of intracellular reactive oxygen species and resulting oxidative stress.
View Article and Find Full Text PDFAspergillus fumigatus is an opportunistic fungal pathogen with small airborne spores (conidia) that may escape clearance by upper airways and directly impact the alveolar epithelium. Consequently, innate alveolar defense mechanisms are being activated, including professional phagocytosis by alveolar macrophages, recruitment of circulating neutrophils and probably enhanced secretion of pulmonary surfactant by the alveolar type II (AT II) cells. However, no data are available in support of the latter hypothesis.
View Article and Find Full Text PDFBackground: Subtrochanteric or supracondylar femoral rotational osteotomies are established surgical treatments for femoral rotational deformities. Unintended change of the mechanical leg axis is an identified problem. Different attempts exist to plan a correct osteotomy plane, but implementation of the preoperative planning into the surgical situation can be challenging.
View Article and Find Full Text PDFRay resection is frequently performed in cases of infection or ischemia, but the literature is scarce concerning its outcome as a definitive treatment. In this retrospective cohort study, we reviewed our cohort with transmetatarsal ray resection with a mean follow-up of 36.3 months.
View Article and Find Full Text PDFTotal transmetatarsal amputation (TMA) can be an option for foot salvage in gangrene, sepsis, or infected necrosis. However, the literature concerning predictive outcome factors and bacterial sampling is scarce. To identify potential associations between revision surgery and underlying bacteria or other preoperative selection criteria, we reviewed all patients with TMA who were treated at our institution.
View Article and Find Full Text PDFIn alveolar type II (AT II) cells, pulmonary surfactant (PS) is synthetized, stored and exocytosed from lamellar bodies (LBs), specialized large secretory organelles. By applying polarization microscopy (PM), we confirm a specific optical anisotropy of LBs, which indicates a liquid-crystalline mesophase of the stored surfactant phospholipids (PL) and an unusual case of a radiation-symmetric, spherocrystalline organelle. Evidence is shown that the degree of anisotropy is dependent on the amount of lipid layers and their degree of hydration, but unaffected by acutely modulating vital cell parameters like intravesicular pH or cellular energy supply.
View Article and Find Full Text PDFThe molecular basis involving adsorption of pulmonary surfactant at the respiratory air-liquid interface and the specific roles of the surfactant proteins SP-B and SP-C in this process have not been completely resolved. The reasons might be found in the largely unknown structural assembly in which surfactant lipids and proteins are released from alveolar type II cells, and the difficulties to sample, manipulate and visualize the adsorption of these micron-sized particles at an air-liquid interface under appropriate physiological conditions. Here, we introduce several approaches to overcome these problems.
View Article and Find Full Text PDFPulmonary surfactant (PS) is an essential complex of lipids and specific proteins synthesized in alveolar type II pneumocytes, where it is assembled and stored intracellularly as multilayered organelles known as lamellar bodies (LBs). Once secreted upon physiological stimulation, LBs maintain a densely packed structure in the form of lamellar body-like particles (LBPs), which are efficiently transferred into the alveolar air-water interface, lowering surface tension to avoid lung collapse at end-expiration. In this work, the structural organization of membranes in LBs and LBPs freshly secreted by primary cultures of rat ATII cells has been compared with that of native lung surfactant membranes isolated from porcine bronchoalveolar lavage.
View Article and Find Full Text PDFAmbroxol (Ax) is a frequently prescribed drug used to facilitate mucociliary clearance, but its mode of action is yet poorly understood. Here we show by X-ray spectroscopy that Ax accumulates in lamellar bodies (LBs), the surfactant storing, secretory lysosomes of type II pneumocytes. Using lyso- and acidotropic substances in combination with fluorescence imaging we confirm that these vesicles belong to the class of acidic Ca(2+) stores.
View Article and Find Full Text PDFLung alveolar type II (ATII) cells are specialized in the synthesis and secretion of pulmonary surfactant, a lipid-protein complex that reduces surface tension to minimize the work of breathing. Surfactant synthesis, assembly and secretion are closely regulated and its impairment is associated with severe respiratory disorders. At present, well-established ATII cell culture models are not available.
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