Structural and functional impairments of skeletal muscle in patients with postacute sequelae of SARS-CoV-2 infection.

Following acute coronavirus disease 2019 (COVID-19), a substantial proportion of patients showed symptoms and sequelae for several months, namely the postacute sequelae of COVID-19 (PASC) syndrome. Major phenomena are exercise intolerance, muscle weakness, and fatigue. We aimed to investigate the physiopathology of exercise intolerance in patients with PASC syndrome by structural and functional analyses of skeletal muscle.

Efficacy of Physiotherapy Interventions on Weaning in Mechanically Ventilated Critically Ill Patients: A Systematic Review and Meta-Analysis.

Mechanical ventilation (MV) is currently considered a life-saving intervention. However, growing evidence highlighted that prolonged MV significantly affects functional outcomes and length of stay. In this scenario, controversies are still open about the optimal rehabilitation strategies for improving MV duration in ICU patients.

Electronic cigarette use among Italian smokers: patterns, settings, and adverse events.

Objective: Information is scanty on the patterns and settings of electronic cigarette use and on its possible adverse events. To fill the knowledge gap on these issues, we conducted a survey among ever-smokers attending smoking cessation services (SCS) in Italy.

Methods: In 2016-2018, we enrolled 395 ever-smokers aged ⩾18 years who were current or former electronic cigarette users in 12 SCS from northern, central, and southern Italy.

Organizational determinants of hospital stay: establishing the basis of a widespread action on more efficient pathways in medical units.

Given the high hospital costs, the increasing clinical complexity and the overcrowding of emergency departments, it is crucial to improve the efficiency of medical admissions. We aimed at isolating organizational drivers potentially targetable through a widespread improvement action. We studied all medical admissions in a large tertiary referral hospital from January 1st to December 31st, 2018.

The earlier, the better: Impact of early diagnosis on clinical outcome in idiopathic pulmonary fibrosis.

Background: Idiopathic pulmonary fibrosis (IPF) is a complex disease with a highly variable clinical course and generally poor prognosis. Classified as a rare disease, significant increases in incidence have been recorded worldwide in recent years. Left untreated IPF is extremely debilitating with substantial personal, social and economic implications.

Iron and iron chelators: a review on potential effects on skin aging.

Similar to oxygen, iron is essential for aerobic life and energy production. Akin to oxygen, iron can be toxic and accelerate the aging process. Indeed, via the Fenton and Haber Weiss reactions, iron potentiates the generation of highly reactive oxygen free radicals such as hydroxyl radical, thus stimulating oxidative damage.

REACH: impact on the US cosmetics industry?

The Registration, Evaluation, Authorization and restriction of Chemicals (REACH) is a recent European regulation on chemical substances meant to protect human health and the environment. REACH imposes the "precautionary principle" where additional data and definitive action are required when uncertainty is identified. The cosmetics industry is only partially concerned by REACH: while the stages of registration and evaluation apply to cosmetics, those of authorization and restriction most likely will not, as cosmetic ingredients are already subject to regulation by various agencies and directives.

The stratum corneum: a double paradox.

The stratum corneum (SC) (i.e., the outermost layer of human skin) is a complex and paradoxical tissue composed of corneocytes and a matrix of intercellular lipids playing an essential role as the skin's protective barrier.

Increased proteolysis of diphtheria toxin by human monocytes after heat shock: a subsidiary role for heat-shock protein 70 in antigen processing.

The expression of heat-shock proteins (hsp) increases after exposure to various stresses including elevated temperatures, oxidative injury, infection and inflammation. As molecular chaperones, hsp have been shown to participate in antigen processing and presentation, in part through increasing the stability and expression of major histocompatibility complex molecules. Heat shock selectively increases human T-cell responses to processed antigen, but does not affect T-cell proliferation induced by non-processed antigens.

Respiratory muscle fibres: specialisation and plasticity.

Skeletal muscles are composed of fibres of different types, each type being identified by the isoform of myosin heavy chain which is expressed as slow 1, fast 2A, fast 2X, and fast 2B. Slow fibres are resistant to fatigue due to their highly oxidative metabolism whereas 2X and 2B fibres are easily fatiguable and fast 2A fibres exhibit intermediate fatigue resistance. Slow fibres and fast fibres are present in equal proportions in the adult human diaphragm while intercostal muscles contain a higher proportion of fast fibres.

Clenbuterol antagonizes glucocorticoid-induced atrophy and fibre type transformation in mice.

Beta-agonists and glucocorticoids are frequently coprescribed for chronic asthma treatment. In this study the effects of 4 week treatment with beta-agonist clenbuterol (CL) and glucocorticoid dexamethasone (DEX) on respiratory (diaphragm and parasternal) and limb (soleus and tibialis) muscles of the mouse were studied. Myosin heavy chain (MHC) distribution, fibres cross sectional area (CSA), glycolytic (phosphofructokinase, PFK; lactate dehydrogenase, LDH) and oxidative enzyme (citrate synthase, CS; cytochrome oxidase, COX) activities were determined.

Iron as the malignant spirit in successful ageing.

Iron enhances the production of the highly reactive and toxic hydroxyl radical, thus stimulating oxidative damage. Iron has been associated with a number of oxidative injury-dependent, age-related conditions and diseases. Indeed, oxidative injury is a major factor of (accelerated) ageing.

Effects of exogenous surfactant and recombinant human copper-zinc superoxide dismutase on oxygen-dependent antimicrobial defenses.

The use of human recombinant CuZn superoxide dismutase (rhSOD) in addition to exogenous surfactant has been studied as a therapeutic strategy to prevent acute and chronic lung injury in premature infants with blood monocytes (MO). However, scavenging of superoxide by rhSOD may compromise bacterial killing by phagocytes. In the present study, we investigated the interaction of exogenous surfactant and rhSOD with the antibacterial activity of human blood MO.

Expression and localization of heat shock proteins in rat basophilic leukemia cells: differential modulation by degranulation, thermal or oxidative stress.

Background: Rat basophilic leukemia (RBL-2H3) cells are well characterized in terms of morphological and biochemical changes upon activation, and have been extensively used as a model system for studying the mechanisms of the immediate hypersensitivity reaction. To investigate whether overexpression of heat shock/stress proteins (HSP) is involved in the mast cell-dependent reactivity, we examined the adaptive responses of RBL-2H3 cells to classical stress conditions such as heat shock or oxidative injury produced by an aqueous extract of tobacco smoke.

Methods: HSP were determined by flow cytometry and immunocytochemistry.

Toxicity of cadmium in tobacco smoke: protection by antioxidants and chelating resins.

The effects of cadmium, an environmental toxin present in tobacco smoke, were studied in vitro in human monocytes and compared to those of tobacco smoke. Overexpression of the 72kDa heat shock/stress protein Hsp70 and cell death occurred with a similar time-course and to a similar extent in human monocytes exposed to either cadmium or tobacco smoke. Cadmium and tobacco smoke-mediated toxicity were associated with a decrease in the cellular content of glutathione and ATP and the glutathione precursor N-acetyl-L-cysteine prevented both cadmium and tobacco smoke-mediated toxicity.

Hyperthermia assists survival of astrocytes from oxidative-mediated necrotic cell death.

In response to many stresses and pathologic states, including different models of nervous system injury, cells synthesize a variety of proteins, most notably the inducible 72 kDa heat shock protein 70 (Hsp70), which plays important roles in maintaining cellular integrity and viability. We report here that cultured astrocytes from rat diencephalon express high levels of Hsp70 upon exposure to elevated temperatures, and are less vulnerable to a subsequent oxidative stress. Complex oxidative stress was induced by exposure of astrocytes to an aqueous extract of tobacco smoke.

Mitochondrial membrane potential: a novel biomarker of oxidative environmental stress.

Epidemiologic analyses, traditionally based on long-term cohort or case-control studies, provide retrospective causal associations between exposure to a particular environmental stressor and an exposure-related disease end point. Recent research initiatives have propelled a shift toward exploring molecular epidemiology and molecular biological markers (biomarkers) as a means of providing more immediate, quantitative risk assessment of potentially deleterious environmental exposures. We compared, in normal human monocytes isolated from the blood of healthy donors, variations in Hsp70 expression and mitochondrial membrane potential (delta psi m) in response to exposure to either tobacco smoke or gamma-irradiation, two models for environmentally mediated oxidant exposure.

Mitochondrial alterations precede Bordetella pertussis-induced apoptosis.

Bordetella pertussis, the causative agent of whooping cough in humans, secretes a number of toxins, including adenylate cyclase-hemolysin (AC-Hly), and induces macrophage apoptosis. We investigated the effects of B. pertussis on mitochondrial membrane potential (deltapsim) and ATP levels, as possible determinants of cell death.

Geranylgeranylacetone protects human monocytes from mitochondrial membrane depolarization independently of Hsp70 expression.

The anti-ulcer drug geranylgeranylacetone (GGA) has been shown to induce the expression of heat shock proteins (HSPs), in particular of Hsp70, in gastric and small intestine cells. In this study, we investigated whether GGA was able to induce Hsp70 in another cell type, human monocytes, which represent a well-established model of Hsp70 expression under oxidative stress. In these cells, GGA had no significant effect either on basal or tobacco smoke-induced Hsp70 expression.

Proliferation and activation of bronchial epithelial cells in corticosteroid-dependent asthma.

Background: Structural and functional characteristics of bronchial epithelial cells in corticosteroid-dependent asthma are unknown.

Objective: In bronchial biopsy specimens from 16 control, 9 untreated asthmatic, 9 inhaled corticosteroid-treated asthmatic, and 19 corticosteroid-dependent asthmatic subjects, we evaluated epithelium morphology and patterns of cell apoptosis, proliferation, and activation.

Methods: We used the terminal deoxynucleotidyl-mediated dUTP nick end labeling (TUNEL) technique to study apoptosis.

Mitochondrial membrane potential and apoptosis peripheral blood monocytes in severe human sepsis.

Unlabelled: Reduced mitochondrial membrane potential (Delta(Psi)m), which is considered as an initial and irreversible step towards apoptosis, as well as cell death regulating proteins, such as Fas, Hsp70, or Bcl-2, may play an important role in sepsis. We studied the relationship between sepsis severity and peripheral blood monocyte Delta(Psi)m, cell death (necrosis and apoptosis), soluble Fas ligand, Hsp70, and Bcl-2 expression over time in 18 patients with sepsis, and compared these data with those of a group of 17 healthy control subjects. All measurements were performed within 3 d of the onset of severe sepsis (T1), then 7 to 10 d later (T2), and finally at hospital discharge (T3).

Treatment with 815-nm diode laser induces long-lasting expression of 72-kDa heat shock protein in normal rat skin.

Background: We previously reported that skin closure is improved by photoirradiation of the wound margins with an 815-nm diode laser system.

Objectives: To determine whether the beneficial effects of laser treatment involve the overexpression of the inducible 72-kDa heat shock protein, Hsp70.

Methods: Expression of Hsp70 was investigated by immunocytochemistry in normal hairless rat dorsal skin and compared with its expression after laser photoirradiation.

Laser assisted skin closure (LASC) by using a 815-nm diode-laser system accelerates and improves wound healing.

Background And Objective: This study aimed to evaluate a 815-nm diode-laser system to assist wound closure to accelerate and improve healing process.

Study Design/materials And Methods: A total of 25 male hairless rats (mutant OFA Sprague-Dawley rats, IFFA-CREDO, L'Arbresle, France) with four dorsal skin incisions were used for the study. For each wound, the good apposition of the edges was obtained with buried absorbable suture.

Polymorphism in the regulatory sequence of the human hsp70-1 gene does not affect heat shock factor binding or heat shock protein synthesis.

A bi-allelic polymorphism found in the regulatory region of the human heat shock (HS) protein (HSP) hsp70-1 gene, which comprises an A-->C transversion, 3 bp upstream of the HS element (HSE), has been associated with extended HLA haplotypes. In view of the chaperoning and protective functions of Hsp70, we investigated whether this hsp70-1 bi-allelic polymorphism could modulate the stress response, which may relate to enhanced resistance or susceptibility to certain diseases. We compared the basal and HS-induced HS factor (HSF)-binding activity of the two polymorphic HSEs, hsp70-1 mRNA accumulation and HSP expression in two human Epstein Barr virus (EBV)-transformed B cell lines typed for hsp70-1 promoter alleles.

Effects of tobacco smoke and benzo[a]pyrene on human endothelial cell and monocyte stress responses.

Smoking is an important risk factor for atherosclerosis. We compared tobacco smoke filtrate with benzo[a]pyrene (a prominent xenobiotic component of tobacco smoke) for the capacity to induce stress proteins and cause cell death in human monocytes and vascular endothelial cells, two cell types that are involved in the formation of atherosclerotic lesions. Exposure to freshly prepared filtrates of tobacco smoke induced in both monocytes and endothelial cells expression of the inducible heat shock protein (HSP)70 and heme oxygenase-1 (HO-1) and produced loss of mitochondrial membrane potential.