Human Pulmonary Disease Research Articles

Fabrication of a Physiologically Relevant Novel Lung‐on‐a‐Chip for the Study of Human Pulmonary Disease and Drug Toxicity

In the scope of biomedical research, many advances have been made in the field of pulmonology with the use of multiple animal models and traditional cell culture experimentation. While these methods are useful when studying single cellular pathways or overarching biological processes, they often falter when studying the meticulous nature of human disease. In this work, we propose the development of a novel Lung‐on‐a‐Chip device that would more accurately mimic the physiological boundaries of human alveoli than animal models or traditional in vitro studies. Utilizing multiple microfabrication techniques, we are developing a microfluidic device with an ultra‐thin (25μm) biodegradable porous silicon membrane. Current data suggests that human pulmonary epithelial and endothelial cells are viable and prolific on the proposed microfabricated silicon membrane in extended studies (14 days). Due to the biodegradability of the fabricated novel silicon membranes, it has been observed in long term studies that cells can remodel and degrade the porous silicon membrane. This degradation allows for physiological cellular contact between membranes mimicking a true blood gas exchange interface as observed in vivo. To further validate this model’s ability to recapitulate human physiology, we have begun to co‐culture with immunological cell types and are monitoring for response to bacterial and tumor antigens. Preliminary data suggests that immunological cells are able to remodel the porous silicon membrane substrate and migrate across cellular boundaries in response to environmental cues as seen in vivo. Broadly, we believe that this model may be used to further characterize and study human pulmonary disease and drug toxicity.Support or Funding InformationMaximizing Access to Research Careers Undergraduate Student Training in Academic Research Award# T34GM092711NSF PREM for Functional Nanomaterials, Award# 1827847STROBE NSF Science and Technology Center on Real‐Time Functional Imaging, Award# 1548924.

Nontuberculous Mycobacterium in Pulmonary & Extrapulmonary Tuberculosis: Stilla Neglected & Underdiagnosed Pathogen in Developing Countries

Non-tuberculous mycobacterium (NTM) has been identified in human pulmonary and extra pulmonary diseases and is of great concern for clinicians and microbiologists because of their increasing global incidence. They are now increasingly recognized as important pathogens in both immunocompromised and immunocompetent population. They should be identified rapidly and should be carefully differentiated as contamination, colonization ordisease. Cultures were made on conventional LJ and LJ with PNB media. Growth was confirmed as AFB (acid fast bacilli) by ZN staining. NTM were identified by growth on LJ with PNB media, colony morphology, rate of growth, pigmentation, catalase activity and confirmed by MPT 64 antigen rapid test (using SD Bioline TB Ag MPT 64 test kit) . Data was analysed statistically using SPSS software. Out of total 500 processed samples (250 pulmonary & 250 extrapulmonary), 12(21.05%) and 7(21.8%) NTM were isolated from pulmonary and extrapulmonary samples respectively. Maximum pulmonary NTM (41.7%) were isolated from > 60 years age of patients in contrast to extrapulmonary NTM isolates which were more in 20-40 years of age group. There was 16.7% previously treated patients in pulmonary while 100% were newly diagnosed patients in extrapulmonary TB cases. This study highlights the importance of early diagnosis and differentiation among Mycobacterium tuberculosisand NTM so that these NTM are not underestimated in routine diagnostic procedures merely as environmental or laboratory contaminants.

Evaluation of particulate matter PM2.5 and PM10 ,(Case study: Khash cement company, Sistan and Baluchestan)

Introduction: One of the most important contaminants in the cement industry are environmental suspended particles (PM2.5 and PM10), which cause respiratory and pulmonary diseases in humans. Materials and methods: This descriptive - analytical study was carried out in 2016-2017 on the peripheral particulate matter of Khash cement plant. Sampling was performed at 8 environmental stations of Khash Cement Company in spring, summer, fall and winter. A total of 576 samples were sampled of peripheral particulate matter. Results: The amount of particulate matter was PM2.5 2.82 to 24.63 μg/m3, respectively. The highest PM2.5 content was obtained in spring (24.32±2.51 μg/m3). The lowest amount of particulate matter PM2.5 in different seasons were measured in substation (P<0.05). The amount of particulate matter was PM10 19.98 to 68.22 μg/m3, respectively. The highest PM10 content was obtained in autumn (64.92±3.76 μg/m3). The lowest amount of particulate matter PM10 in spring and summer were measured in substation (P<0.05), but the lowest amounts in the autumn at the entrance door and in winter was observed in wastewater treatment. Conclusion: In this study, the amount of PM2.5 and PM10 peripheral particulate matter in Cement Company was lower than WHO and USEPA standard. According to the results it can be stated that the suspended particles Khash Cement Company environment for human respiration were within acceptable limits.

Clinical value of non-coding RNAs in cardiovascular, pulmonary, and muscle diseases.

Although a majority of the mammalian genome is transcribed to RNA, mounting evidence indicates that only a minor proportion of these transcriptional products are actually translated into proteins. Since the discovery of the first non-coding RNA (ncRNA) in the 1980s, the field has gone on to recognize ncRNAs as important molecular regulators of RNA activity and protein function, knowledge of which has stimulated the expansion of a scientific field that quests to understand the role of ncRNAs in cellular physiology, tissue homeostasis, and human disease. Although our knowledge of these molecules has significantly improved over the years, we have limited understanding of their precise functions, protein interacting partners, and tissue-specific activities. Adding to this complexity, it remains unknown exactly how many ncRNAs there are in existence. The increased use of high-throughput transcriptomics techniques has rapidly expanded the list of ncRNAs, which now includes classical ncRNAs (e.g., ribosomal RNAs and transfer RNAs), microRNAs, and long ncRNAs. In addition, splicing by-products of protein-coding genes and ncRNAs, so-called circular RNAs, are now being investigated. Because there is substantial heterogeneity in the functions of ncRNAs, we have summarized the present state of knowledge regarding the functions of ncRNAs in heart, lungs, and skeletal muscle. This review highlights the pathophysiologic relevance of these ncRNAs in the context of human cardiovascular, pulmonary, and muscle diseases.

Necroptosis: a crucial pathogenic mediator of human disease.

Necroptosis is a genetically regulated form of necrotic cell death that has emerged as an important pathway in human disease. The necroptosis pathway is induced by a variety of signals, including death receptor ligands, and regulated by receptor-interacting protein kinases 1 and 3 (RIPK1 and RIPK3) and mixed-lineage kinase domain-like pseudokinase (MLKL), which form a regulatory necrosome complex. RIPK3-mediated phosphorylation of MLKL executes necroptosis. Recent studies, using animal models of tissue injury, have revealed that RIPK3 and MLKL are key effectors of injury propagation. This Review explores the functional roles of RIPK3 and MLKL as crucial pathogenic determinants and markers of disease progression and severity in experimental models of human disease, including acute and chronic pulmonary diseases; renal, hepatic, cardiovascular, and neurodegenerative diseases; cancer; and critical illness.

Periostin and Inflammatory Disease: Implications for Chronic Rhinosinusitis.

To provide a comprehensive overview of the emerging role of periostin, an extracellular matrix protein, as a key component in the development, diagnosis, and treatment of patients with chronic rhinosinusitis. Medline database. A state of the art review was performed targeting English-language studies investigating the role of periostin in cardiopulmonary, neoplastic, and inflammatory diseases, with emphasis on recent advances in the study of periostin in chronic rhinosinusitis. Periostin has emerged as a novel biomarker and therapeutic target for numerous human pathologies, including cardiac, pulmonary, and neoplastic disease. The upregulation of periostin in chronic rhinosinusitis suggests the potential for similar roles among patients with sinonasal disease. Chronic rhinosinusitis is a widespread disease with major clinical and societal impact. A critical limitation in the current treatment of patients with chronic rhinosinusitis is the absence of clinically relevant biomarkers to guide diagnosis and treatment selection. A review of the literature supports a likely role of periostin as a biomarker of chronic rhinosinusitis, as well as a novel therapeutic target in the future treatment of patients with sinonasal disease.

Human Herpesvirus 6B and Pulmonary Disease after Hematopoietic Cell Transplantation

Background: Human herpesvirus 6B (HHV-6B) DNA is frequently detected in bronchoalveolar lavage fluid (BALF) from immunocompromised subjects with lower respiratory tract disease (LRTD). Whether HHV-6B is a pulmonary pathogen is unclear. Methods: We tested prospectively stored BALF for HHV-6B DNA using PCR in allogeneic hematopoietic cell transplantation (HCT) recipients who underwent a BAL for evaluation of LRTD from 1992-2015. We used multivariable proportional hazards models to evaluate the association of HHV-6B+ BALF with overall mortality, death from respiratory failure, and the effect of anti-HHV-6B antivirals on these outcomes. We used branched chain RNA in-situ hybridization (RISH) to detect HHV-6 messenger RNA (U41 and U57) in lung tissue. Findings: We detected HHV-6B+ BALF from 147 of 553 (27%) individuals. Subjects with HHV-6B+ BALF, with or without copathogens, had significantly increased risk of overall mortality (adjusted hazard ratio [HR], 2.06; 95% CI, 1.33-3.21) and death from respiratory failure (aHR, 2.26; 95% CI, 1.44-3.56) compared to subjects with HHV-6B- BALF. Subjects with HHV-6B+ BALF who received antivirals within 3 days pre-BAL had an approximately 1 log10 lower median HHV-6B BALF viral load and lower risk of overall mortality compared to subjects with HHV-6B+ BALF not receiving antivirals (aHR, 0.44; 95% CI, 0.17-1.11). We detected intraparenchymal HHV-6 gene expression by RISH in lung tissue in all 3 tested subjects with HHV-6B+ BALF and sufficient tissue RNA preservation. Interpretation: These data provide evidence that HHV-6B is a pulmonary pathogen after allogeneic HCT. Definitive evidence of causation will require a randomized prevention or treatment trial. Funding: National Institutes of Health, the American Society for Blood and Marrow Transplantation, the HHV-6 Foundation. Declaration of Interest: J.A.H. served as a consultant for Chimerix, Nohla Therapeutics, Inc., and Amplyx and has received research support from Chimerix, Shire, and Karius, Inc. outside the submitted work. C.E.F. has received a grant from Gilead Sciences outside of the submitted work. L.C. has received research support from Sanofi and Immune Design and is a co-inventor on several patents associated with the development of an HSV-2 vaccine; he has no conflicts in the area of HHV-6. M.B. received grants and/or personal fees from Chimerix Inc. and Microbiotix outside the submitted work. L.K.V-V, H.X., E.L.C., S.S., T.S-A, M-L.H, K.R.J., F.M.S, D.M.Z., and W.M.L declare no competing interests. Ethical Approval: The study was approved by the FHCRC Institutional Review Board.

Nocardia paucivorans cerebellar abscess: Surgical and pharmacotherapy

Background:Nocardia species are ubiquitous in nature and mainly cause pulmonary disease in humans; however, they can also infect the central nervous system and skin. The management of cerebellar nocardiosis is troublesome and requires multiple considerations of the severity of the underlying systemic disease, difficulties in identifying the bacterium, and frequent delay in initiating adequate therapy.Case Description:We report a 52-year-old diabetic female patient with Nocardia paucivorans cerebellar abscesses. Brain magnetic resonance imaging (MRI) revealed innumerable small ring-enhancing lesions of posterior fossa. In this report, we present a case of primary single cerebellar abscesses due to N. paucivorans. Early diagnosis and surgical interventions were significant for the patient. The diagnosis was confirmed by DNA sequencing and the organism was susceptible to trimethoprim–sulfamethoxazole (TMP/SMX). The patient was successfully treated with drugs and surgical excision.Conclusion:According to the literature, surgical excision or aspiration of cerebellar abscess seems to provide favorable outcomes. In our experience, a successful outcome was achieved with subtotal resection and prolonged adequate antibiotic therapy.

Tissue-informed engineering strategies for modeling human pulmonary diseases.

Chronic pulmonary diseases, including idiopathic pulmonary fibrosis (IPF), pulmonary hypertension (PH), and chronic obstructive pulmonary disease (COPD), account for staggering morbidity and mortality worldwide but have limited clinical management options available. Although great progress has been made to elucidate the cellular and molecular pathways underlying these diseases, there remains a significant disparity between basic research endeavors and clinical outcomes. This discrepancy is due in part to the failure of many current disease models to recapitulate the dynamic changes that occur during pathogenesis in vivo. As a result, pulmonary medicine has recently experienced a rapid expansion in the application of engineering principles to characterize changes in human tissues in vivo and model the resulting pathogenic alterations in vitro. We envision that engineering strategies using precision biomaterials and advanced biomanufacturing will revolutionize current approaches to disease modeling and accelerate the development and validation of personalized therapies. This review highlights how advances in lung tissue characterization reveal dynamic changes in the structure, mechanics, and composition of the extracellular matrix in chronic pulmonary diseases and how this information paves the way for tissue-informed engineering of more organotypic models of human pathology. Current translational challenges are discussed as well as opportunities to overcome these barriers with precision biomaterial design and advanced biomanufacturing techniques that embody the principles of personalized medicine to facilitate the rapid development of novel therapeutics for this devastating group of chronic diseases.

Radiolabelled leucocytes in human pulmonary disease.

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). Mostly the authors' own studies, following on from studies of the early pioneers. From early imaging studies, it appeared that the majority of the marginated granulocyte pool was located in the lungs. However, later work disputed this by demonstrating the exquisite sensitivity of granulocytes to ex vivo isolation and labelling, and that excessive lung activity is artefactual. Following refinement of labelling techniques, it was shown that the majority of marginated granulocytes are located in the spleen and bone marrow. The majority of leucocytes have a pulmonary vascular transit time only a few seconds longer than erythrocytes. The minority showing slow transit, ~5% in healthy persons, is increased in systemic inflammatory disorders that cause neutrophil priming and loss of deformability. Using a range of imaging techniques, including gamma camera imaging, whole-body counting and single photon-emission computerized tomography, labelled granulocytes were subsequently used to image pulmonary trafficking in lobar pneumonia, bronchiectasis, chronic obstructive pulmonary disease and adult respiratory distress syndrome. More recently, eosinophils have been separated in pure form using magnetic bead technology for the study of eosinophil trafficking in asthma. These include advancement of eosinophil imaging, development of monocyte labelling, development of cell labelling with PET tracers and the tracking of lymphocytes.

Phylogeny, ecology and taxonomy of systemic pathogens and their relatives in Ajellomycetaceae (Onygenales): Blastomyces, Emergomyces, Emmonsia, Emmonsiellopsis

The family Ajellomycetaceae (Onygenales) includes mammal-associated pathogens within the genera Blastomyces, Emmonsia, Histoplasma and Paracoccidioides, as well as the recently described genera, Emergomyces that causes disease in immunocompromised hosts, and Emmonsiellopsis, known only from soil. To further assess the phylogenetic relationships among and between members of these genera and several previously undescribed species, we sequenced and analyzed the DNA-directed RNA polymerase II (rPB2), translation elongation factor 3-α (TEF3), β-tubulin (TUB2), 28S large subunit rDNA (LSU) and the internal transcribed spacer regions (ITS) in 68 strains, in addition to morphological and physiological investigations. To better understand the thermal dimorphism among these fungi, the dynamic process of transformation from mycelial to yeast-like or adiaspore-like forms was also assessed over a range of temperatures (6–42 °C). Molecular data resolved the relationships and recognized five major well-supported lineages that correspond largely to the genus level. Emmonsia, typified by Emmonsia parva, is a synonym of Blastomyces that also accommodates Blastomyces helicus (formerly Emmonsia helica). Emmonsia crescens is phylogenetically distinct, and found closely related to a single strain from soil without known etiology. Blastomyces silverae, Emergomyces canadensis, Emergomyces europaeus and Emmonsia sola are newly described. Almost all of the taxa are associated with human and animal disease. Emmonsia crescens, B. dermatitidis and B. parvus are prevalently associated with pulmonary disease in humans or animals. Blastomyces helicus, B. percursus, Emergomyces africanus, Es. canadensis, Es. europaeus, Es. orientalis and Es. pasteurianus (formerly Emmonsia pasteuriana) are predominantly found in human hosts with immune disorders; no animal hosts are known for these species except B. helicus.

Adjunctive moxibustion treatment for tuberculosis: A randomised clinical trial investigating potential efficacy and comparative safety

IntroductionSmall cone direct moxibustion (‘moxa’) is known to have been used in Japan at the height of its tuberculosis (TB) epidemic in the pre-antibiotic era with documented reports of efficacy including one scientific animal study. Antimicrobial resistant (AMR) disease is becoming a major threat to global health with drug-resistant TB the largest component of this threat, most particularly in Africa and Asia. This study comprises the first scientific investigation into whether this simple traditional therapy might help the challenge of reducing the persistent burden of TB in middle- and low-income countries. Methods180 newly diagnosed TB patients were randomly assigned to two groups, one given standard first line ‘Directly Observed Treatment, Shortcourse’ (DOTS) TB drug therapy, and the other first line DOTS along with daily self-administered moxibustion. The two groups were carefully monitored for differences in recovery rates and serological and immunological markers were compared. ResultsThe moxa group responded to the drug therapy faster than the group receiving standard TB therapy as measured by their becoming sputum negative (P = 0.032 in the first month). There were accompanying improved haemoglobin levels of statistical significance (P = 0.003) with the same P value seen in a sub-group of TB patients who were also HIV positive. It was also noted that the moxa patients reported statistically significant better adherence to their drug therapy (P = 0.001). ConclusionsThe results demonstrate positive effects of moxa treatment on both reduced infectivity and drug adherence including in HIV co-infected cases. Despite previous reports of a wider range of haematological effects, these were limited to an increase in haemoglobin. There was no evidence that moxa use led to improvements in patients’ well-being, contrary to previous anecdotal evidence.The paper concludes that more investigations should be developed to provide a broader understanding of both effect and potential benefit of moxa therapy in treating human pulmonary TB disease (both with and without co-infection with HIV). It further recommends that these should include MDR-, XDR-, (multi-drug resistant and extensively-drug resistant) and programmatically-untreatable TB (including in palliative care scenarios).

Long noncoding RNA LISPR1 is required for S1P signaling and endothelial cell function

Sphingosine-1-Phosphate (S1P) is a potent signaling lipid. The effects of S1P are mediated by the five S1P receptors (S1PR). In the endothelium S1PR1 is the predominant receptor and thus S1PR1 abundance limits S1P signaling. Recently, lncRNAs were identified as a novel class of molecules regulating gene expression. Interestingly, the lncRNA NONHSAT004848 (LISPR1, Long intergenic noncoding RNA antisense to S1PR1), is closely positioned to the S1P1 receptors gene and in part shares its promoter region. We hypothesize that LISPR1 controls endothelial S1PR1 expression and thus S1P-induced signaling in endothelial cells. In vitro transcription and translation as well as coding potential assessment showed that LISPR1 is indeed noncoding. LISPR1 was localized in both cytoplasm and nucleus and harbored a PolyA tail at the 3’end. In human umbilical vein endothelial cells, as well as human lung tissue, qRT-PCR and RNA-Seq revealed high expression of LISPR1. S1PR1 and LISPR1 were downregulated in human pulmonary diseases such as COPD. LISPR1 but also S1PR1 were induced by inflammation, shear stress and statins. Knockdown of LISPR1 attenuated endothelial S1P-induced migration and spheroid outgrowth of endothelial cells. LISPR1 knockdown decreased S1PR1 expression, which was paralleled by an increase of the binding of the transcriptional repressor ZNF354C to the S1PR1 promoter and a reduction of the recruitment of RNA Polymerase II to the S1PR1 5’end. This resulted in attenuated S1PR1 expression and attenuated S1P downstream signaling. Collectively, the disease relevant lncRNA LISPR1 acts as a novel regulatory unit important for S1PR1 expression and endothelial cell function.

Tamoxifen induces apoptotic neutrophil efferocytosis in horses.

Macrophages and neutrophils are important cellular components in the process of acute inflammation and its subsequent resolution, and evidence increasingly suggests that they play important functions during the resolution of chronic, adaptive inflammatory processes. Exacerbated neutrophil activity can be harmful to surrounding tissues; this is important in a range of diseases, including allergic asthma and chronic obstructive pulmonary disease in humans, and equine asthma (also known as recurrent airway obstruction (RAO). Tamoxifen (TX) is a non-steroidal estrogen receptor modulator with effects on cell growth and survival. Previous studies showed that TX treatment in horses with induced acute pulmonary inflammation promoted early apoptosis of blood and BALF neutrophils, reduction of BALF neutrophils, and improvement in animals' clinical status. The aim of this study was to describe if TX induces in vitro efferocytosis of neutrophils by alveolar macrophages. Efferocytosis assay, myeloperoxidase (MPO) detection and translocation phosphatidylserine (PS) were performed on neutrophils isolated from peripheral blood samples from five healthy horses. In in vitro samples from heathy horses, TX treatment increases the phenomenon of efferocytosis of peripheral neutrophils by alveolar macrophages. Similar increases in supernatant MPO concentration and PS translocation were observed in TX-treated neutrophils, compared to control cells. In conclusion, these results confirm that tamoxifen has a direct effect on equine peripheral blood neutrophils, through stimulation of the engulfment of apoptotic neutrophils by alveolar macrophages.

The Human Microbiome in the Fight Against Tuberculosis.

AbstractThe human microbiome is an intriguing potentially modifiable risk factor in our arsenal against Mycobacterium tuberculosis, the leading infectious disease killer globally. Previous studies have shown associations between the human microbiome and pulmonary disease states; however, etiological links between the microbiome and tuberculosis (TB) infection or disease remain unclear. Immunomodulatory roles of the microbiome may prove to be a critical asset in the host response against TB, including in preventing TB infection, reducing progression from latency, mitigating disease severity, and lowering the incidence of drug resistance and coinfections. This review examined the associations between TB and the gut and lung microbiome. Eight studies were identified through a PubMed database search, including one animal study (N = 1), case report (N = 1), and case-control studies (N = 6). TB infection and disease were associated with reduced gastrointestinal microbial diversity in a murine model and human case report. Sputum microbial diversity differed by TB status in case-control studies, although some reported heterogeneous findings. Current evidence suggests that the gut and lung microbiome are associated with TB infection and disease. However, as studies are limited, etiological and longitudinal research is needed to determine clinical relevance.

Microencapsulation of Lefty-secreting engineered cells for pulmonary fibrosis therapy in mice.

Idiopathic pulmonary fibrosis (IPF) is a progressive disease that causes unremitting deposition of extracellular matrix proteins, thus resulting in distortion of the pulmonary architecture and impaired gas exchange. Associated with high morbidity and mortality, IPF is generally refractory to current pharmacological therapies. Lefty A, a potent inhibitor of transforming growth factor-β signaling, has been shown to have promising antifibrotic ability in vitro for the treatment of renal fibrosis and other potential organ fibroses. Here, we determined whether Lefty A can attenuate bleomycin (BLM)-induced pulmonary fibrosis in vivo based on a novel therapeutic strategy where human embryonic kidney 293 (HEK293) cells are genetically engineered with the Lefty A-associated GFP gene. The engineered HEK293 cells were encapsulated in alginate microcapsules and then subcutaneously implanted in ICR mice that had 1 wk earlier been intratracheally administered BLM to induce pulmonary fibrosis. The severity of fibrosis in lung tissue was assessed using pathological morphology and collagen expression to examine the effect of Lefty A released from the microencapsulated cells. The engineered HEK293 cells with Lefty A significantly reduced the expression of connective tissue growth factor and collagen type I mRNA, lessened the morphological fibrotic effects induced by BLM, and increased the expression of matrix metalloproteinase-9. This illustrates that engineered HEK293 cells with Lefty A can attenuate pulmonary fibrosis in vivo, thus providing a novel method to treat human pulmonary fibrotic disease and other organ fibroses.

Particle-induced Pulmonary Alveolar Proteinosis and Subsequent Inflammation and Fibrosis: A Toxicologic and Pathologic Review.

This review analyzes the published data on cases of pulmonary alveolar proteinosis (PAP) in workers inhaling crystalline aluminum, indium, silicon, and titanium particles and possible sequelae, that is, inflammation and fibrosis, and compares these findings with those from animal experiments. In inhalation studies in rodents using crystalline indium and gallium compounds, pronounced PAP followed by inflammation and fibrosis down to very low concentration ranges have been reported. Crystalline aluminum, silicon, and titanium compounds also induced comparable pulmonary changes in animals, though at higher exposure levels. Laboratory animal species appear to react to the induction of PAP with varying degrees of sensitivity. The sensitivity of humans to environmental causes of PAP seems to be relatively low. Up to now, no cases of PAP, or other pulmonary diseases in humans, have been described for gallium compounds. However, a hazard potential can be assumed based on the results of animal studies. Specific particle properties, responsible for the induction of PAP and its sequelae, have not been identified. This review provides indications that, both in animal studies and in humans, PAP is not often recognized due to the absence of properly directed investigation or is concealed behind other forms of lung pathology.

Sepsis in frail patient

Frailty is defined as a clinical syndrome in which three or more of the following criteria are present: unintentional weight loss, self-reported exhaustion, weakness (grip strength), slow walking speed and low physical activity. Sepsis is defined as an inflammatory response to infection, with severe sepsis and septic shock being the most severe forms. The incidence of severe sepsis increases with older age and several studies have shown that there are many risk factors that predispose the elderly to a higher incidence of sepsis. Pre-existing co-morbidities such as cancer, diabetes, obesity, human immunodeficiency virus, and renal or pulmonary disease can cause sepsis, but other factors including poor lifestyle habits (i.e., smoking, drug or alcohol abuse), malnutrition, and endocrine deficiencies, which are frequent in the elderly, may also predispose to severe infections. Other risk factors for sepsis include recurrent hospitalization, especially in the Intensive Care Unit, and nursing home residence, where interventions such as urinary catheterization or multiple drug use are quite frequent and many studies reported that people above 65 years of age are three times more likely to be admitted to hospital than those aged 16-64 years, and have a higher risk of prolonged hospital stays, institutionalization and death. Clinical evaluation of the frail patient with sepsis poses some challenges. The immune response becomes progressively less efficient with increasing age thereby causing an altered response to infection and it is important to know that the clinical evaluation of the so-called fragile patient with severe infection should take into account the sometimes unusual signs and symptoms that, if identified, can lead to early diagnosis. Laboratory diagnostics can also be of great help in this setting. The treatment of sepsis in the fragile patient can be empirical or based on microbiological culture. Moreover, frail patient population presents many clinical problems with numerous comorbidities, therefore anti-infective treatment is difficult, so the physician’s armamentarium must include many antibiotic drugs, of which there are far more available for the treatment of sepsis caused by Gram-positive bacteria than for sepsis caused by Gram-negative ones or fungi.

In Vitro effects of tamoxifen on equine neutrophils

Neutrophils participate in innate immunity as the first line of host defense against microorganisms. However, exacerbated neutrophil activity can be harmful to surrounding tissues; this is important in a range of diseases, including allergic asthma and chronic obstructive pulmonary disease in humans, and equine asthma (also known as recurrent airway obstruction (RAO). Tamoxifen (TX) is a non-steroidal estrogen receptor modulator with effects on cell growth and survival. Previous preliminary studies showed that TX treatment in horses with induced acute pulmonary inflammation promoted early apoptosis of blood and BALF neutrophils, reduction of BALF neutrophils, and improvement in animals' clinical status. The aim of this study was to evaluate the in vitro effect of TX on functional tests in equine peripheral blood neutrophils. Chemotaxis, respiratory burst production and phagocytosis assays were performed on neutrophils isolated from peripheral blood samples from 10 healthy horses. Results showed that IL-8 stimulated cells decrease their chemotactic index when treated with TX (1 and 10μM). Respiratory burst production was also dampened after treatment with TX. In conclusion, these results confirm that tamoxifen has a direct action on equine peripheral blood neutrophils. However, more in vivo and in vitro studies are required to fully understand the mechanisms of action of TX on neutrophils, in order to elucidate if it can be used as treatment in disorders such as allergic asthma in humans and horses.

Cell-derived microparticles and the lung.

Cell-derived microparticles are small (0.1-1 μm) vesicles shed by most eukaryotic cells upon activation or during apoptosis. Microparticles carry on their surface, and enclose within their cytoplasm, molecules derived from the parental cell, including proteins, DNA, RNA, microRNA and phospholipids. Microparticles are now considered functional units that represent a disseminated storage pool of bioactive effectors and participate both in the maintenance of homeostasis and in the pathogenesis of diseases. The mechanisms involved in microparticle generation include intracellular calcium mobilisation, cytoskeleton rearrangement, kinase phosphorylation and activation of the nuclear factor-κB. The role of microparticles in blood coagulation and inflammation, including airway inflammation, is well established in in vitro and animal models. The role of microparticles in human pulmonary diseases, both as pathogenic determinants and biomarkers, is being actively investigated. Microparticles of endothelial origin, suggestive of apoptosis, have been demonstrated in the peripheral blood of patients with emphysema, lending support to the hypothesis that endothelial dysfunction and apoptosis are involved in the pathogenesis of the disease and represent a link with cardiovascular comorbidities. Microparticles also have potential roles in patients with asthma, diffuse parenchymal lung disease, thromboembolism, lung cancer and pulmonary arterial hypertension.