Like father, like son: Pulmonary thromboembolism due to inflammatory or hereditary condition? Two case reports

BACKGROUND

Venous thromboembolism, which includes deep venous thrombosis and pulmonary embolism, is a well-known causal disorder with high morbidity and mortality rates. Inherited or acquired conditions affecting components of coagulation and fibrinolysis systems have been linked to venous thromboembolism pathogenesis as they may lead to a pro-inflammatory state in human bodies. Toxoplasmosis is a zoonosis that potentially leads to acute systemic cachectic-inflammatory effects in experimental animal models but is not yet proven in humans. It is known that venous thrombosis can occur during acute inflammatory/infectious diseases, although it is not well established with regard to toxoplasmosis alone.

CASE SUMMARY

A 70-year-old Caucasian man and his 32-year-old son developed general malaise, chills, fever, and myalgia, having established a diagnosis of toxoplasmosis. Twenty days later, they presented dry cough leading to further investigations that revealed an incidental deep venous thrombosis plus pulmonary embolism in them both. Thrombophilia screening showed both patients had a factor V Leiden mutation heterozygosis. Father and son completely recovered without any sequalae after anticoagulant treatment. They have not presented symptom recurrence of either medical disorder during 1 year of follow-up.

CONCLUSION

Toxoplasmosis may enhance the risk of venous thromboembolism in patients showing factor V Leiden mutation heterozygosis.

SARS-CoV-2 with concurrent coccidioidomycosis complicated by refractory pneumothorax in a Hispanic male: A case report and literature review

BACKGROUND

The incidence of secondary coinfections particularly fungal infections among severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is not well described. Little is known of the complications that could be encountered in such conditions.

CASE SUMMARY

A 50-year-old Hispanic male who was a prior smoker presented with shortness of breath. He was diagnosed with SARS-CoV-2. He improved and was discharged with home oxygen. A month later, he presented with sudden onset cough and shortness of breath. Chest X-ray showed development of right-sided tension pneumothorax, right pleural effusion and an air-filled cystic structure. Computed tomography thorax showed findings suggestive of pulmonary coccidioidomycosis. Coccidioides antigen was positive, and fluconazole was initiated. For pneumothorax, a pigtail catheter was placed. The pigtail chest tube was later switched to water seal, unfortunately, the pneumothorax re-expanded. Another attempt to transition chest tube to water seal was unsuccessful. Pigtail chest tube was then swapped to 32-Fr chest tube and chemical pleurodesis was performed. This was later transitioned successfully to water seal and finally removed. He was discharged on a four-week oral course of fluconazole 400 mg and was to follow up closely as an outpatient for continued monitoring.

CONCLUSION

Pneumothorax is associated with a worse prognosis, especially with comorbidities such as diabetes, immunosuppression and malignancy. Suspicion for concomitant fungal infection in such patients should be high and would necessitate further investigation.

Personalising exacerbation prediction strategies in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of mortality and morbidity worldwide. One of the most important features of this disease is exacerbations where a patient’s respiratory symptoms episodically worsen. Exacerbations accounted for over 140000 hospital admissions in 2012 in the United Kingdom with considerably more exacerbations being treated in primary care. Despite significant research in this area in recent years, treatment of acute exacerbations in the community remains limited to oral glucocorticoids, antibiotics and bronchodilators. One of the issues with unpicking the complexity of exacerbations is trying to find out the exact underlying cause and mechanism that leads to symptoms and lung destruction. Currently symptoms are initially guided by symptoms alone though multiple causes of exacerbations have common presentations. This includes viral and bacterial infections and episodes relating to environmental triggers such as pollen and pollution. There is also evidence that cardiovascular factors can contribute to symptoms of breathlessness that can mimic COPD exacerbations. In this editorial we discuss recent advances in the use of precision medicine to more accurately treat exacerbations of COPD. This includes identification of phenotypes that could help rationalise treatment and more importantly identify novel drug targets. We also consider the future role of precision medicine in preventing exacerbations and identifying COPD patients that are at increased risk of developing them.

Relationship between metabolic syndrome and hypercapnia among obese patients with sleep apnea

BACKGROUND

In the obese patient population, some patients have severe obstructive sleep apnea (OSA) with daytime hypoventilation. Such patients are generally identified on the basis of the presence or absence of daytime hypercapnia, and the condition is called obesity hypoventilation syndrome. However, mechanisms for such daytime hypoventilation remain unclear.

AIM

To investigate metabolic syndrome and daytime hypercapnia association based on hypercapnia prevalence in obese OSA patients in a nested case-control study.

METHODS

Consecutive obese patients (body mass index ≥ 30 kg/m²) who underwent polysomnography due to suspected OSA were included. Among them, patients with severe OSA (apnea hypopnea index ≥ 30/h) were divided into two groups according to the presence or absence of hypercapnia during wakefulness (arterial partial pressure of carbon dioxide ≥ or < 45 Torr, respectively). The characteristics and clinical features of these two groups were compared.

RESULTS

Among 97 eligible patients, 25 patients (25.8%) had daytime hypercapnia. There were no significant differences in age, gender, body mass index, apnea-hypopnea index, and Epworth Sleepiness Scale scores between the two groups. However, patients with hypercapnia had a significantly lower arterial partial pressure of oxygen level (75.8 ± 8.2 torr vs 79.9 ± 8.7 torr, P = 0.042) and higher arterial partial pressure of carbon dioxide level (46.6 ± 2.5 torr vs 41.0 ± 2.9 torr, P < 0.001). Additionally, patients with hypercapnia were more likely to have metabolic syndrome (72.0% vs 48.6%, P = 0.043) and a higher metabolic score (the number of satisfied criteria of metabolic syndrome). In multivariate logistic regression analysis, the presence of metabolic syndrome was associated with the presence of hypercapnia (OR = 2.85, 95%CI: 1.04-7.84, P = 0.042).

CONCLUSION

Among obese patients with severe OSA, 26% of patients had hypercapnia during wakefulness. The presence of metabolic syndrome was independently correlated with the presence of daytime hypercapnia.

Diagnosis and treatment of subsegmental pulmonary embolism

Subsegmental pulmonary embolism (SSPE) affects the 4th division and more distal pulmonary arterial branches. SSPE can be isolated or affect multiple subsegments, be symptomatic or incidental (unsuspected) and may or may not be associated with deep vein thrombosis. Symptoms, clinical risk scores and biomarkers are less sensitive for diagnosing SSPE compared to more central pulmonary embolism. The diagnosis is confirmed using radiological imaging, predominately computed tomographic pulmonary angiogram (CTPA) or ventilation/perfusion scanning. The increasing utilization of CTPAs may have resulted in overdiagnosis driven by smaller pulmonary emboli. There is insufficient evidence of improved mortality or reduced venous thromboembolism recurrence with anticoagulation treatment for SSPE however, the major and clinically significant haemorrhage risks are well described. As the resolution of diagnostic imaging has improved, we may be viewing the natural physiological filtering process performed by the lungs that may not require treatment.

Anatomical backgrounds on gas exchange parameters in the lung

Many problems regarding structure-function relationships have remained unsolved in the field of respiratory physiology. In the present review, we highlighted these uncertain issues from a variety of anatomical and physiological viewpoints. Model A of Weibel in which dichotomously branching airways are incorporated should be used for analyzing gas mixing in conducting and acinar airways. Acinus of Loeschcke is taken as an anatomical gas-exchange unit. Although it is difficult to define functional gas-exchange unit in a way entirely consistent with anatomical structures, acinus of Aschoff may serve as a functional gas-exchange unit in a first approximation. Based on anatomical and physiological perspectives, the multiple inert-gas elimination technique is thought to be highly effective for predicting ventilation-perfusion heterogeneity between acini of Aschoff under steady-state condition. Changes in effective alveolar P_O2, the most important parameter in classical gas-exchange theory, are coherent with those in mixed alveolar P_O2 decided from the multiple inert-gas elimination technique. Therefore, effective alveolar-arterial P_O2 difference is considered useful for assessing gas-exchange abnormalities in lung periphery. However, one should be aware that although alveolar-arterial P_O2 difference sensitively detects moderately low ventilation-perfusion regions causing hypoxemia, it is insensitive to abnormal gas exchange evoked by very low and high ventilation-perfusion regions. Pulmonary diffusing capacity for CO (D_LCO) and the value corrected for alveolar volume (V_AV), i.e., D_LCO/V_AV (K_CO), are thought to be crucial for diagnosing alveolar-wall damages. D_LCO-related parameters have higher sensitivity to detecting abnormalities in pulmonary microcirculation than those in the alveolocapillary membrane. We would like to recommend four categories derived from combining behaviors of D_LCO with those of K_CO for differential diagnosis on anatomically morbid states in alveolar walls: type-1 abnormality defined by decrease in both D_LCO and K_CO; type-2 abnormality by decrease in D_LCO but increase in K_CO; type-3 abnormality by decrease in D_LCO but restricted rise in K_CO; and type-4 abnormality by increase in both D_LCO and K_CO.

Treatment of central sleep apnea in patients with heart failure: Now and future

Heart failure (HF) is known to be associated with sleep-disordered breathing (SDB). In addition to disturbing patients’ sleep, SDB is also associated with a deterioration in the cardiac function and an increased mortality and morbidity. Central sleep apnea (CSA), typically characterized by Cheyne-Stokes breathing (CSB), is increasingly found in patients with HF compared to the general population. An important pathogenetic factor of CSA seen in HF patients is an instability in the control of the respiratory system, characterized by both hypocapnia and increased chemosensitivity. Sympathetic overactivation, pulmonary congestion and increased chemosensitivity associated with HF stimulate the pulmonary vagal irritant receptor, resulting in chronic hyperventilation and hypocapnia. Additionally, the repetitive apnea and arousal cycles induce cyclic sympathetic activation, which may worsen the cardiac prognosis. Correcting CSB may improve both patient’s quality of life and HF syndrome itself. However, a treatment for HF in patients also experiencing CSA is yet to be found. In fact, conflicting results from numerous clinical studies investigating sleep apnea with HF guide to a troubling question, that is whether (or not) sleep apnea should be treated in patients with HF? This editorial attempts to both collect the current evidence about randomized control trials investigating CSA in patients with HF and highlight the effect of specific CSA treatments on cardiovascular endpoints.

Classical regression equations of spirometric parameters are not applicable for diagnosing spirometric abnormalities in adipotic adults

The prevalence of overweighing and obese adults (defined as “adipotic” adults), has markedly increased over the world. A remarkable increase in the adipotic population urgently needs developing the regression equations for predicting spirometric parameters (SPs), which are specifically applicable to adipotic adults. Unfortunately, however, the reliable equations suitable for adipotic adults have not been reported to date. Recently, Yamaguchi et al have proposed the quantitative method to estimate the effects of adiposity on deciding the SPs incorporating with age-specific contributions of various explanatory, independent variables such as age (A), standing height (H), body weight (BW), and fat fraction of body mass (F). Extending the method proposed by Yamaguchi et al, we attempted to elaborate the novel regression equations applicable for diagnosing the spirometric abnormality in adipotic adults. For accomplishing this purpose, never-smoking, adipotic adults with body mass index (BMI) over 25 kg/m² and no respiratory illness were recruited from the general population in Japan (n = 3696, including men: 1890 and women: 1806). Introducing the four explanatory variables of A, H, BW, and F, gender-specific and age-dependent regression equations that allowed for prescribing the SPs in adipotic adults were constructed. Comparing the results obtained for non-adipotic adults (i.e., those with normal BMI), the negative or positive impact of height on SPs was preserved in adipotic adults, as well. However, the negative impact of age on SPs was blunted in adipotic men and the positive effect of BW on SPs was impeded in adipotic men and women. The fat fraction of body mass-elicited negative impact on SPs vanished in adipotic women. These results indicate that the regression equations of SPs for adipotic adults differ significantly from those for non-adipotic adults, leading to the conclusion that the regression equations for non-adipotic adults should not be used while judging the spirometric abnormalities in adipotic adults.

Is the determination of ctDNA a scientific “spy” that foresees cancer?

Since 1948, circulating tumour DNA (ctDNA) was first identified in human blood. ctDNA is in fact DNA shed by tumour cells from all metastatic tumour locations throughout the whole body, and is thrown into the bloodstream and can then be isolated by a standard blood draw. Using this technique scientists can obtain a wide view of tumour heterogeneity, identify different mechanisms of drug resistance, what is its predominance and the clinical rational of precision cancer medicine become a part of our daily practice. Secondly, early detection of cancer may also contribute to global decrease in cancer mortality.

Lung microbiome in healthy and diseased individuals

The data on quantitative and qualitative microbial composition of the respiratory tract of healthy individuals revealed significant differences when compared with the microbiota of patients suffering from respiratory diseases. Possible etiological role of microbiota in pulmonary diseases as well as drug resistance development is of profound interest nowadays. Numerous studies have provided evidence confirming the relationship between gut microbiome and those of lungs. This relationship could explain how changes in the microbial communities in one organ may lead to pathological changes in the other. Till date, some progress has been made in the study of the biological properties of probiotic bacteria, considering their modulating effect on inflammatory immune response. The use of probiotics which exhibits an immunomodulatory potential looks promising.

Advance of antioxidants in asthma treatment

Asthma is an allergic disease, characterized as a recurrent airflow limitation, airway hyperreactivity, and chronic inflammation, involving a variety of cells and cytokines. Reactive oxygen species have been proven to play an important role in asthma. The pathogenesis of oxidative stress in asthma involves an imbalance between oxidant and antioxidant systems that is caused by environment pollutants or endogenous reactive oxygen species from inflammation cells. There is growing evidence that antioxidant treatments that include vitamins and food supplements have been shown to ameliorate this oxidative stress while improving the symptoms and decreasing the severity of asthma. In this review, we summarize recent studies that are related to the mechanisms and biomarkers of oxidative stress, antioxidant treatments in asthma.

Synchronous lung and breast cancer

Synchronous tumors are an uncommon finding. We present a case of metastatic carcinoma of right breast and a left lung adenocarcinoma in a patient with previous history of left breast cancer diagnosed twelve years ago. She was then treated with chemotherapy, radiotherapy and hormone therapy. Initially, the greatest diagnostic challenge was which of them had spread or if both had. Or even if, any of these lesions resulted from the primary left breast cancer. So, specimens of different metastatic lesions were crucial to answer this query and to decide the best therapeutic approach. Sequencing the treatment options in managing two synchronous secondary malignancies, where one of them is metastatic and the other one is potentially curable, was a demanding clinical decision.

Phenotyping emphysema and airways disease: Clinical value of quantitative radiological techniques

The pathophysiology of chronic obstructive pulmonary disease (COPD) and Alpha one antitrypsin deficiency is increasingly recognised as complex such that lung function alone is insufficient for early detection, clinical categorisation and dictating management. Quantitative imaging techniques can detect disease earlier and more accurately, and provide an objective tool to help phenotype patients into predominant airways disease or emphysema. Computed tomography provides detailed information relating to structural and anatomical changes seen in COPD, and magnetic resonance imaging/nuclear imaging gives functional and regional information with regards to ventilation and perfusion. It is likely imaging will become part of routine clinical practice, and an understanding of the implications of the data is essential. This review discusses technical and clinical aspects of quantitative imaging in obstructive airways disease.

Pulmonary complications of transcatheter arterial chemoembolization for hepatocellular carcinoma

Transarterial chemoembolization (TACE) is an effective palliative intervention that is widely accepted for the management of hepatocellular carcinoma (HCC). Post-TACE pulmonary complications resulting in acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) are rare events. Pulmonary complications after TACE are thought to be related to chemical injury subsequent to the migration of the infused ethiodized oil or chemotherapeutic agent to the lung vasculature, facilitated by arteriovenous (AV) shunts within the hyper-vascular HCC. We review herein the literature on pulmonary complications related to TACE for HCC. Post-TACE pulmonary complications have included pulmonary oil embolism, interstitial pneumonitis, chemical pneumonitis, ALI, ARDS, lipoid pneumonia, acute eosinophilic and neutrophilic pneumonia, bilious pleuritis, pulmonary abscess, pulmonary tumor embolism, and possibly pulmonary metastasis with HCC. The risk factors associated with post-TACE pulmonary complications identified in the literature include large hyper-vascular HCC with AV shunts, large-volume Lipiodol infusion, and embolization via the right inferior phrenic artery. However, the absence of known risk factors is not a guarantee against serious complications. An astute awareness of the potential post-TACE pulmonary complications should expedite appropriate therapeutic interventions and increase potential for early recovery.

Bronchial hyperresponsiveness in childhood: A narrative review

Bronchial hyperresponsiveness (BHR) is an important but not asthma-specific characteristic and can be assessed by direct and indirect methods, based on the stimulus causing airway obstruction. BHR has been proposed as a prognostic marker of asthma severity and persistence, and may also be used to control pharmacological management of asthma. The most recent data on the prevalence and development of BHR in childhood and its predictive value for subsequent asthma development in late adolescence and adulthood is discussed in this review. According to the BHR-related scientific articles written in the English language and indexed in the publicly searchable PubMed database, the prevalence of BHR varies based upon the methods used to assess it and the population examined. In general, however, BHR prevalence is reduced as children grow older, in both healthy and asthmatic populations. While asthma can be predicted by BHR, the predictive value is limited. Reduced lung function, allergic sensitization, female sex, and early respiratory illness have been identified as risk factors for BHR. The collective studies further indicate that BHR is a dynamic feature related to asthma, but asymptomatic BHR is also common. Ultimately, the prevalence of BHR varies depending on the population, the environment, and the evaluation methods used. While both the methacholine challenge and the exercise test may predict asthma in adolescence or early adulthood, the predictive value is higher for the methacholine challenge compared to the exercise test. The collective data presented in the present study demonstrate how BHR develops through childhood and its relation to bronchial asthma.

Asthma-chronic obstructive pulmonary disease overlap syndrome: A diagnostic puzzle for the clinicians

Although asthma and chronic obstructive pulmonary disease (COPD) are distinct airway diseases characterized by chronic inflammation, in some cases distinguishing between them is puzzling. For example, chronic smoking leads asthmatic inflammation to a differentiated pattern resembling the COPD inflammation, and in some cases to fixed obstruction as in COPD, and on the other hand, few COPD patients may present with airway reversibility. ACOS is the condition sharing features encountered both in asthma and COPD. Asthma-COPD overlap syndrome (ACOS) represents a diagnostic challenge in the clinical practice, since there is lack of specific indicators to distinguish it from asthma or COPD, and moreover, genetic risk factors, underlying pathology and molecular pathways, clinical characteristics, therapeutic interventions, response to treatment and prognosis are poorly described. The management of ACOS is recommended to be individualized and should target on the maximum effectiveness with the least side effects. Combination therapy with ICS/LABA or LAMA, or newly developed specific anti-eosinophil therapies and treatments specifically targeting neutrophils might be of relevance in the management of ACOS, but studies are needed in order to assess the response and prognosis. Based on the current knowledge about ACOS thus far, it would be recommended that we approached chronic obstructive airway disease rather by describing than by classifying the disease; this would allow us to have a picture that better describes the disease and to implement an individualized therapeutic approach, according to the custom phenotype. Nevertheless, more studies are needed in order to clarify several important issues with regard to ACOS, such as the genetic risk factors for developing ACOS, the links between genotype and phenotype, the molecular pathways and underlying mechanisms of ACOS, the identification of possible specific biomarkers for diagnosis and targeted treatment, the optimal therapeutic interventions, and finally, the prognosis of ACOS.

Automated weaning from mechanical ventilation

Mechanical ventilation (MV) is one of the lifesaving techniques applied to critically ill patients at bedside. However, some complications, such as ventilator-induced lung injury and ventilator-associated pneumonia, may occur in a patient undertaking MV and are often related to the duration of MV. Some written protocols have been proposed to reduce the risk of such complications, but they can be time consuming, leading to fluctuation in protocol implementation and compliance. Moreover, written instructions tend to be general and thus cannot cover all possible scenarios, resulting in variable interpretation of the protocol. To overcome these limiting factors, protocols have been computerized and there is convincing evidence in the literature showing that computerized protocols benefit management of the process and reduce the time a patient spends under MV. QuickWean is a computer-aided weaning protocol implemented on the Hamilton S1 ventilator (Hamilton Medical AG, Bonaduz, Switzerland), which guides the patient through the weaning process without requiring any intervention by the treating physician. The fully-automated ventilation mode is INTELLiVENT^®-ASV (Hamilton Medical AG), which is set according to the patient’s respiratory mechanics, patient-ventilator interaction, peripheral oxygen saturation (SpO₂) and pulmonary end-tidal carbon dioxide (PetCO₂). The INTELLiVENT^®-ASV mode sets automatically each minute to provide accurate ventilation, pressure support, fraction of inspired oxygen and positive end-expiratory pressure based on the patient’s needs. QuickWean can be pre-set to match the established weaning policy of an intensive care unit as well as being customized to a patient’s needs. It provides a progressive reduction of respiratory support, and guides the patient through the spontaneous breathing trial (SBT). At the end of the SBT, the ventilator re-starts the previous ventilation support and provides a report of the successful SBT. During all phases, PetCO₂, SpO₂ and all breathing parameters are monitored. This new automated weaning tool may improve the safety and effectiveness of an SBT, reducing the time spent in the process of weaning and providing a lower workload for the treating physician.

New era of epidermal growth factor receptor-tyrosine kinase inhibitors for lung cancer

Lung cancer is the leading cause of death globally, besides recent advances in its management; it maintains a low 5-year survival rate of 15%. The discovery of epidermal growth factor receptor (EGFR) activating mutations and the introduction of its tyrosine kinase inhibitors (TKIs) have expanded the treatment options for patients with non-small cell lung cancer. Nowadays, EGFR mutation testing is now a common routine for newly diagnosed lung cancer. First generation TKIs developed, erlotinib and gefitinib, were reversible ones. After a median of 14 mo, eventually all EGFR mutated patients develop resistance to reversible TKIs. Afatinib, dacomitinib and neratinib, second generation inhibitors, are selective and irreversible TKIs. Finally, third generation phase I clinical trials were performed, with lower toxicity profiles, and targeting with more precision the driving clone of this heterogeneous disease.

Prognostic scoring systems for clinical course and survival in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is the most common and rapidly fatal among idiopathic interstitial pneumonias. Its clinical course is variable. A significant fraction of the population of patients display a slow disease course and can remain stable for years, while other patients show a rapid progressive course and may die within few months from diagnosis. For these reasons estimating prognosis of IPF patients is extremely difficult and has important clinical repercussions on optimal patients management including patients referral for lung transplantation. Several studies have tried to address this key point in the course of the two last decades analyzing different clinical, functional, radiological and biological variables. The purpose of this review is to assess relevant studies published on this subject and to examine the variety of prognostic predictors proposed along with staging systems.

Multicenter cooperative observational study of idiopathic pulmonary fibrosis with non-small cell lung cancer

AIM: To research the natural course of idiopathic pulmonary fibrosis (IPF) with advanced non-small cell lung cancer (NSCLC) and the association between acute exacerbation (AE) of IPF and chemotherapy (CT).

METHODS: From May 2007 through April 2011, 17 CT naive patients with IPF and advanced NSCLC were enrolled. Patients were classified into best supportive care (BSC) group or CT group based on the patient’s preference. Patients in the CT group received carboplatin (CBDCA) (AUC 5-6) plus paclitaxel (PTX) (175-200 mg/m²) on day 1 of each 21-d cycle as first-line therapy.

RESULTS: All patients but one chose the CT group. In the CT group, the objective response rate was 38%. The most frequent toxicity ≥ grade 3 was neutropenia (88%). Two patients (12.5%) developed AE-IPF. The median progression-free survival, the median survival time and the 1-year survival rate were 4.1 mo, 8.7 mo and 35%, respectively. Second-line CT-related AE and CT-unrelated AE occurred in 2 and 3 patients (1: BSC group; 2: CT group), respectively. Seven (41%) of all patients developed AE-IPF throughout the clinical course, and 6 of 7 patients with AE-IPF died within one month.

CONCLUSION: The incidence of AE-IPF was higher among IPF patients with advanced NSCLC than among those without NSCLC. CBDCA plus PTX regimen was tolerable and effective. However, AE-IPF has a fatal toxicity with or without CT in IPF patients with advanced NSCLC.

Pulmonary effects of intermittent, seasonal exposure to high concentrations of cotton dust

AIM: To quantify the exposure levels and to assess pulmonary reactions associated with exposure to cotton dust and its biological contaminants.

METHODS: All employees (51 male workers) of a ginning industry as well as 51 referent unexposed subjects from clerical staff of an educational center were investigated. Atmospheric concentrations of cotton dust and bioaerosols were measured. Furthermore, bacterial and fungal genera and species were identified by an expert microbiologist and an experienced mycologist. A standard respiratory symptom questionnaire was filled out for the subjects and they underwent multiple spirometry tests, at the beginning and at the end of work season as well as prior to (pre-exposure base line values) and at end of the first shift of workweek (post exposure).

RESULTS: Gram negative bacteria including Enterobacter agglomerans and Pseudomonas spp. were found to be the dominant bacterial species and genera, respectively. Similarly, dominant fungi were identified to be Mucor sp. Rhizopus sp. and Aspergillus niger. Mean atmospheric concentrations of cotton dust in ginning and outdoor areas were found to be 35.2 and 6.8 mg/m³, respectively. The prevalence rates of cough, phlegm, wheezing, dyspenea and grade 1/2 byssinosis among the exposed subjects were significantly higher than their corresponding values for the unexposed employees (P < 0.05). Additionally, significant differences were noted in the mean baseline value (preshift) of vital capacity, forced expiratory volume in the first second (FEV1) and FEV1/forced vital capacity ratio of the exposed subjects when compared with those of their referent counterparts. Similarly, significant cross shift decrements were noted in most parameters of pulmonary function of the exposed subjects.

CONCLUSION: Seasonal exposure to cotton dust induces both acute, partially reversible, and chronic irreversible decrements in the lungs’ functional capacities as well as increased prevalence of respiratory symptoms.

Interactions between traffic air pollution and glutathione S-transferase genes on childhood asthma

AIM: To evaluate the role of glutathione S-transferase P1 (GSTP1) genetic polymorphisms potentially modifying the association between NO₂ and asthma/wheeze in Taiwanese children.

METHODS: We investigated 3714 schoolchildren in Taiwan Children Health Study from 14 communities. Children’s information was measured from questionnaire by parents. The traffic air pollutant was available from Environmental Protection Administration monitoring stations.

RESULTS: A two-stage hierarchical model and a multiple logistic regression model were fitted to estimate the effects of NO₂ exposures and GSTs polymorphisms on the prevalence of asthma and wheeze. Among children with GSTP1 Ile/Val or Val/Val genotypes, those residing in high-NO₂ communities had significantly increased risks of asthma (OR = 1.76, 95%CI: 1.15-2.70), late-onset asthma (OR = 2.59, 95%CI: 1.24-5.41), active asthma (OR = 1.93, 95%CI: 1.05-3.57), asthma under medication (OR = 2.95, 95%CI: 1.37-6.32) and wheeze (OR = 1.54, 95%CI: 1.09-2.18) when compared with children in low-NO₂ communities. Significant interactions were noted between ambient NO₂ and GSTP1 on asthma, late-onset asthma, asthma under medication and wheeze (P for interaction < 0.05). However, we did not find any association with polymorphisms in GSTM1 and GSTT1.

CONCLUSION: Children under high traffic air pollution exposure are more susceptible to asthma, especially among those with GSTP1 Val allele.

Lung cancer screening: Should we be excluding people with previous malignancy?

The National Lung Screening Trial (NLST) was a large, randomized, controlled study showing a 20% reduction of lung cancer mortality and 7% reduction of all cause mortality using annual low dose computed tomography (LDCT) in a high risk population. NLST excluded people with a previous history of cancer treatment within the past 5 years and all people with a history lung cancer. The aim of this work is to review how lung cancer screening trials addressed the confounding effect of previous malignancy. We also review the subsequent recommendations by the United States Preventative Task Force Services, multiple professional societies and the Center for Medicaid and Medicare Services which defer either to NLST criteria or, clinician judgment or refrain from asserting any recommendation on the topic, respectively. Implications of lung cancer screening in the setting of previous malignancies, specifically lung, head and neck, esophageal, gastric, breast, colorectal cancer and lymphoma are also discussed. With lung cancer screening, an antecedent malignancy introduces the possibility of discovering metastasis as well as lung cancer. In some circumstances diagnosis and treatment of oligometastatic disease may confer a survival benefit. The survival benefit of treating either lung cancer or oligometastatic disease as result of lung cancer screening has yet to be determined. Further studies are needed to determine the role of lung cancer screening in the setting of previous malignancy.

Questions relating to premenstrual asthma

The study of asthma in fertile women needs to consider its potentially recurrent exacerbation in a specific phase of the menstrual cycle. Premenstrual asthma (PMA) refers to the deterioration of asthma in some women of fertile age during the premenstrual phase. Prevalence varies considerably according to studies (11%-47.44%) mainly because there is no standardized definition of the illness. There is a possible link between PMA and premenstrual syndrome, which is a set of physical and psychic manifestations that occur in some fertile women during the same premenstrual phase. This relation has been widely studied but there are still several unknowns. PMA etiopathogeny is not known. It involves possible causes such as hormonal variations in the premenstrual phase, the coexistence of atopy, variations during the cycle in substances related to inflammation, like LTC4 leukotrienes, catecholamines, E2 and F2α prostaglandins and certain cytokines. Also considered are psychological factors related to this phase of the menstrual cycle, a high susceptibility to infection or increased bronchial hyperreactivity prior to menstruation. Yet no factor fully explains its etiology, consequently no specific treatment exists. Researchers have investigated hormones, anti-leukotrienes, prostaglandin synthesis inhibitors, diuretics, phytoestrogens and alternative therapies, but none has been shown to be effective.

β2-adrenoceptor in obstructive airway diseases: Agonism, antagonism or both?

Obstructive airway disease is a complex disease entity including several maladies characterized by bronchoconstriction and abnormal airway inflammation. Reversing bronchoconstriction leads to symptomatic relief and improvement in quality of life, both in reversible (bronchial asthma) and partially reversible (chronic obstructive airway disease) obstructive airway diseases. β₂-adrenoceptor expressed in human airway is the main β-receptor subtype, and its activation in airway smooth muscle cells leads to bronchodilatation. Drugs targeting β-adrenoceptors have been around for many years, for which agonists of the receptors are used in bronchodilation while antagonists are used in cardiovascular diseases. This review article summarizes the effect and usage of β₂-agonist in obstructive airway disease, addressing the benefits and potential risks of β₂-agonist. The article also looks at the safety of β-blocker usage for cardiovascular disease in patients with obstructive airway disease. There is also emerging evidence that non-selective β-blockers with inverse agonism ironically can have long-term beneficial effects in obstructive airway disease that is beyond cardiovascular protection. Further trials are urgently needed in this area as it might lead to a dramatic turnaround in clinical practice for obstructive airway diseases as has already been seen in the usage of β-blockers for heart failure.

Reducing acute respiratory distress syndrome occurrence using mechanical ventilation

The standard treatment for acute respiratory distress syndrome (ARDS) is supportive in the form of low tidal volume ventilation applied after significant lung injury has already developed. Nevertheless, ARDS mortality remains unacceptably high (> 40%). Indeed, once ARDS is established it becomes refractory to treatment, and therefore avoidance is key. However, preventive techniques and therapeutics to reduce the incidence of ARDS in patients at high-risk have not been validated clinically. This review discusses the current data suggesting that preemptive application of the properly adjusted mechanical breath can block progressive acute lung injury and significantly reduce the occurrence of ARDS.

Post splenectomy related pulmonary hypertension

Splenectomy predisposes patients to a slew of infectious and non-infectious complications including pulmonary vascular disease. Patients are at increased risk for venous thromboembolic events due to various mechanisms that may lead to chronic thromboembolic pulmonary hypertension (CTEPH). The development of CTEPH and pulmonary vasculopathy after splenectomy involves complex pathophysiologic mechanisms, some of which remain unclear. This review attempts congregate the current evidence behind our understanding about the etio-pathogenesis of pulmonary vascular disease related to splenectomy and highlight the controversies that surround its management.

Causes of failure in acute respiratory distress syndrome modeling and treatment in animal research and new approaches

Acute respiratory distress syndrome (ARDS) is a major cause of morbidity, death and cost in intensive care units. Despite intensive research, pharmacotherapy has not passed the experimental stage and mortality rates are still high. Animal models provide a bridge between patients and the laboratory bench. Different animal models have been developed in order to mimic human ARDS, but they have limitations. The purpose of this review was to summarize the properties of the most commonly used experimental animal models mimicking the causes and pathology of human ARDS, the limitations of ARDS models, treatment failure and new therapeutic approaches.

Collagen vascular disease-associated interstitial lung disease

Interstitial lung disease (ILD) is an important manifestation of collagen vascular diseases. It is a common feature of scleroderma, and also occurs in dermatomyositis and polymyositis, mixed connective tissue disease, Sjogren’s syndrome, rheumatoid arthritis, systemic lupus erythematosus, and Antineutrophil cytoplasmic antibody-associated vasculitis. When present, it is associated with increased morbidity and mortality, thus making early diagnosis important. In fact, in many patients, ILD may be the first manifestation of a collagen vascular disease. The most common symptoms are cough and dyspnea. The diagnosis is made based on pulmonary function tests showing restrictive lung disease and impaired oxygen diffusion and chest imaging showing ground glass infiltrates, interstitial thickening, and/or fibrosis. The most common histologic finding on lung biopsy is non-specific interstitial pneumonia, though organizing pneumonia and usual interstitial pneumonia may also be seen. Treatment is focused on addressing the underlying collagen vascular disease with immunosuppression, either with corticosteroids or a steroid-sparing agent such as cyclophosphamide, azathioprine, or mycophenolate, although the optimal agent and duration of therapy is not known. There are few clinical trials to guide therapy that focus specifically on the progression of ILD. The exception is in the case of scleroderma-associated ILD, where cyclophosphamide has been shown to be effective.

Unresectable stage III non-small-cell lung cancer: Have we made any progress?

Lung cancer is responsible for the most cancer deaths worldwide with an incidence that is still rising. One third of patients have unresectable stage IIIA or stage IIIB disease. The standard of care for locally advanced disease in patients with good performance status consists of combined modality therapy in particular concurrent chemoradiotherapy. But despite a lot of efforts done in the past, local control and survival of patients with unresectable stage III non-small-cell lung cancer (NSCLC) remains poor. Improving outcomes for patients with unresectable stage III NSCLC has therefore been an area of ongoing research. Research has focused on improving systemic therapy, improving radiation therapy or adding a maintenance therapy to consolidate the initial therapy. Also implementation of newer targeted therapies and immunotherapy has been investigated as well as the option of prophylactic cranial irradiation. This article reviews the latest literature on improving local control and preventing distant metastases. It seems that we have reached a plateau with conventional chemotherapy. Radiotherapy dose escalation did not improve outcome although increasing radiation dose-intensity with new radiotherapy techniques and the use of newer agents, e.g., immunotherapy might be promising. In the future well-designed clinical trials are necessary to prove those promising results.

Effectiveness of adaptive servo-ventilation

Adaptive servo-ventilation (ASV) has been developed as a specific treatment for sleep-disordered breathing, in particular Cheyne-Stokes respiration with central sleep apnea (CSA). Heart failure patients often have sleep-disordered breathing, which consists of either obstructive sleep apnea (OSA) or CSA. Other medical conditions, such as stroke, acromegaly, renal failure, and opioid use may be associated with CSA. Continuous positive airway pressure (CPAP) therapy is widely used for patients with OSA, but some of these patients develop CSA on CPAP, which is called treatment-emergent CSA. CPAP can be useful as a treatment for these various forms of CSA, but it is insufficient to eliminate respiratory events in approximately half of patients with CSA. As compared to CPAP, ASV may be a better option to treat CSA, with sufficient alleviation of respiratory events as well as improvement of cardiac function in heart failure patients. In patients without heart failure, ASV can also alleviate CSA and relieve their symptom. Recently, ASV has been widely used for patients with various forms of CSA. ASV may be also used in the setting without CSA, but it should be assessed more carefully. Clinicians should have a better understanding of the indications for ASV in each setting.

Role of hydrogen sulphide in airways

The toxicity of hydrogen sulfide (H₂S) has been known for a long time, as it is prevalent in the atmosphere. However accumulative data suggest that H₂S is also endogenously produced in mammals, including man, and is the third important gas signaling molecule, besides nitric oxide and carbon monoxide. H₂S can be produced via non enzymatic pathways, but is mainly synthesized from L-cysteine by the enzymes cystathionine-γ-lyase, cystathionine-β-synthetase, cysteine amino transferase and 3-mercaptopyruvate sulfurtransferase (3MTS). The formation of H₂S from D-cysteine via the enzyme D-amino acid oxidase and 3MTS has also been described. Endogenous H₂S not only participates in the regulation of physiological functions of the respiratory system, but also seems to contribute to the pathophysiology of airway diseases such as chronic obstructive pulmonary disease, asthma and pulmonary fibrosis, as well as in inflammation, suggesting its possible use as a biomarker for these diseases. This review summarizes the different implications of hydrogen sulfide in the physiology of airways and the pathophysiology of airway diseases.

Advanced non-small cell lung cancer in elderly patients: A review

Over 50% of patients diagnosed with non-small-cell lung cancer (NSCLC) are 65 years old while 30% exceed 70 years old. Comparing elderly patients to their younger counterpart they poorly tolerate chemotherapy due to progressive reduction of organ function and age-related co-existing pathologies. Due to this reason elderly are usually excluded from platinum-based chemotherapy, which still represent the standard of care for advanced NSCLC. In every-day practice, single-agent schedule with a third-generation drug is the recommended option for elderly patients with advanced NSCLC. A modest increase in toxicity for elderly patients has been demonstrated by subgroup analyses concluding for platinum-based combination chemotherapy being similar in young patients and fit elderly. Even though the cited evidence, feasibility of chemotherapy based on platinum remains an open question. Prospective randomised trials are warranted in order to change guide lines and give the clinicians a new therapeutic option. Recent emerging role of molecular target in selecting patients for new targeted therapies suggest dedicated trials for elderly patients. The same is for more accurate evaluation of elderly patients with increasing evidence for a comprehensive geriatric assessment as a valid tool for customized treatment in NSCLC elderly patients. Suitable evidences for the treatment of elderly patients affected by advanced NSCLC together with more appropriate and validated tools for patients selection are reviewed along the manuscript.

Current methods of staging and restaging of the mediastinal nodes in non-small-cell lung cancer

To analyze the current methods of primary staging and repeated staging (restaging) of the mediastinal nodes in non-small-cell lung cancer (NSCLC), all methods currently used for staging of NSCLC are analyzed. These methods include imaging techniques [computer tomography (CT), positron emission tomography (PET) combined with CT (PET/CT)], endoscopic/ultrasound techniques (endobronchial ultrasound/transbronchial needle aspiration) and endoscopic ultrasound/fine needle aspiration and surgical techniques [standard cervical mediastinoscopy, video-assisted mediastinoscopy, extended mediastinoscopy, video-assisted mediastinoscopic lymphadenectomy, transcervical extended mediastinal lymphadenectomy, anterior mediastinotomy (Chamberlain procedure) and video-assisted thoracic surgery]. The diagnostic yield of Chest CT is regarded insufficient for both, primary staging and restaging. The PET/CT became a standard imaging technique preceding curative surgery of radical chemo-radiotherapy. The issue of intraoperative staging is also described. Finally, the author’s proposed algorithm of staging, both for primary staging and restaging after neoadjuvant therapy is presented. Detailed staging of NSCLC enables selection of patients with early stage disease for curative surgical/multimodality treatment and helps to avoid unnecessary surgery in advanced disease.

Mechanical circulatory support in lung transplantation: Cardiopulmonary bypass, extracorporeal life support, and ex-vivo lung perfusion

Lung transplant is the standard of care for patients with end-stage lung disease refractory to medical management. There is currently a critical organ shortage for lung transplantation with only 17% of offered organs being transplanted. Of those patients receiving a lung transplant, up to 25% will develop primary graft dysfunction, which is associated with an 8-fold increase in 30-d mortality. There are numerous mechanical lung assistance modalities that may be employed to help combat these challenges. We will discuss the use of mechanical lung assistance during lung transplantation, as a bridge to transplant, as a treatment for primary graft dysfunction, and finally as a means to remodel and evaluate organs deemed unsuitable for transplant, thus increasing the donor pool, improving survival to transplant, and improving overall patient survival.

Screening for lung cancer with chest computerized tomography: Is it cost efficient?

Despite lung cancer (LC) screening by low-dose computerized tomography (LDCT) gaining many proponents worldwide, for many years it was not recognized as a life-prolonging and cost-effective procedure, until recently. Prospective observational studies had not been able to prove that this screening prolongs survival, but they helped to specify the inclusion and exclusion criteria. Long-awaited results of a prospective, randomized trial finally provided the evidence that LC screening with LDCT can prolong survival of the screened population. Several cost-effectiveness analyses were performed to justify mass introduction of this screening. Results of these analyses are equivocal, although conclusions highly depend upon inclusion and exclusion criteria, methods of analysis and prices of medical procedures which differ between countries as well as the incidence of other pulmonary nodules, especially tuberculosis. Therefore, cost-effectiveness analysis should be performed separately for every country. Cost-effectiveness depends especially upon the rate of false-positive results and the rate of unnecessary diagnostic, screening and treatment procedures. To ensure high cost-effectiveness, LC screening should be performed in accordance with screening protocol, in dedicated screening centers equipped with nodule volume change analysis, or as a prospective non-randomized trial, to ensure compliance with the inclusion and exclusion criteria. To ensure high cost-effectiveness of LC screening, future research should concentrate on determination of high-risk groups and further specifying the inclusion and exclusion criteria.

Myasthenia gravis as a form of clinical presentation of thymic carcinoma

Thymic carcinomas are rare tumors of the thymus arising in the thymic epithelium. They represent less than 1% of thymic malignancies. They often present with an advanced disease and metastasize to regional lymph nodes and distant sites. They have a worse prognosis with a 5-year survival rate of 30%-50%, while thymomas are much less invasive and have a 5-year survival of approximately 78%. We report a rare form of clinical presentation of a thymic carcinoma in which the diagnosis of myasthenia gravis was the cornerstone of the diagnosis of cancer. Surgery is considered the salvage treatment when possible. Radiotherapy is a second choice of salvage treatment, when possible depending on its localization and relation to nearby structures such as vascular structures. Molecular target therapy is a more directed, more expensive but less toxic treatment. Further studies need to be carried out for its approval worldwide, outside clinical trials.

Management of recurrent malignant pleural effusions with a tunneled indwelling pleural catheter

In this review, we report on the use of indwelling pleural catheters in the treatment of malignant pleural effusions. We describe the most commonly used catheter. Also, treatment with indwelling pleural catheters as compared to talc pleurodesis is reviewed. A comparison of efficacy, costs, effects on quality of life, and complications is made. Only one randomized controlled trial comparing the two is available up to date, but several are underway. We conclude that treatment for malignant pleural effusions with indwelling pleural catheters is a save, cost-effective, and patient-friendly method, with low complication rates.

Caveolae, caveolin-1 and cavin-1: Emerging roles in pulmonary hypertension

Caveolae are flask-shaped invaginations of cell membrane that play a significant structural and functional role. Caveolae harbor a variety of signaling molecules and serve to receive, concentrate and transmit extracellular signals across the membrane. Caveolins are the main structural proteins residing in the caveolae. Caveolins and another category of newly identified caveolae regulatory proteins, named cavins, are not only responsible for caveolae formation, but also interact with signaling complexes in the caveolae and regulate transmission of signals across the membrane. In the lung, two of the three caveolin isoforms, i.e., cav-1 and -2, are expressed ubiquitously. Cavin protein family is composed of four proteins, named cavin-1 (or PTRF for polymerase Ⅰ and transcript release factor), cavin-2 (or SDPR for serum deprivation protein response), cavin-3 (or SRBC for sdr-related gene product that binds to-c-kinase) and cavin-4 (or MURC for muscle restricted coiled-coiled protein or cavin-4). All the caveolin and cavin proteins are essential regulators for caveolae dynamics. Recently, emerging evidence suggest that caveolae and its associated proteins play crucial roles in development and progression of pulmonary hypertension. The focus of this review is to outline and discuss the contrast in alteration of cav-1 (cav-1),-2 and cavin-1 (PTRF) expression and downstream signaling mechanisms between human and experimental models of pulmonary hypertension.

Polymyxin B-immobilized fiber columns: A column to breathe new life into the treatment of interstitial lung disease?

Acute exacerbations of idiopathic pulmonary fibrosis (IPF) is a severe respiratory condition with high mortality rate. Direct hemoperfusion with polymyxin B-immobilized fiber columns (PMX-DHP) was originally introduced for the treatment of septic shock. Application of PMX-DHP to the treatment of acute exacerbations of IPF may improve oxygenation and survival of the patients with the disease. In addition to acute exacerbations of IPF, PMX-DHP has been applied to acute respiratory failure from various causes; an amyopathic dermatomyositis patient who developed rapidly progressive interstitial lung disease (ILD) with elevated anti-CADM-140/MDA5 autoantibody and a patient with severe amiodarone pulmonary toxicity. It is also demonstrated that PMX-DHP performed on the first day of steroid pulse therapy may improve the prognosis of patients with rapidly progressive ILDs in a case-control setting. PMX treatment decreases not only various circulating molecules but also inflammatory cells, in particular activated monocytes, producing such mediators. Although the incidence of acute exacerbations of IPF is too low for proper randomization, in order to test the effects of PMX-DHP on the disease, a cohort or case-control analytic study needs to be conducted, preferably from more than one center or research group.

Gastroesophageal reflux disease related asthma: From preliminary studies to clinical practice

The diagnosis of asthma requires the presence of episodic respiratory difficulties characterized by variable and reversible airway obstruction. It has a high prevalence worldwide and is traditionally considered to be an allergic disease. Most cases are responsive to treatment with bronchodilators and anti-inflammatories, as recommended by national and international guidelines; however, approximately 10% of asthmatic patients are refractory even to optimal therapy. Gastroesophageal reflux disease (GERD) is a common disorder in asthmatic patients and the two disorders may be linked pathophysiologically. Here we review data from preliminary studies that suggest asthma could be induced or exacerbated by gastroesophageal reflux. The optimal strategies for the diagnosis of GERD-related asthma and its therapy are still debated. However, there is evidence to suggest that antireflux treatment is effective and practical for asthmatic patients with well-defined reflux disease.

Role of p53 in lung tissue remodeling

The tumor suppressor gene p53 regulates a wide range of cellular processes including cell cycle progression, proliferation, apoptosis and tissue development and remodeling. Lung cell apoptosis and tissue remodeling have critical roles in many lung diseases. Abnormal proliferation or resistance to apoptosis of lung cells will lead to structural changes of many lung tissues, including the pulmonary vascular wall, small airways and lung parenchyma. Among the many lung diseases caused by vascular cell apoptosis and tissue remodeling are chronic obstructive pulmonary disease, bronchial asthma and pulmonary arterial hypertension. Recent advances in biology and medicine have provided new insights and have resulted in new therapeutic strategies for tissue remodeling in human and animal models. This review is focused on lung disease susceptibility associated with the p53 pathway and describes molecular mechanisms upstream and downstream of p53 in lung tissue remodeling. Improved understanding of structural changes associated with pulmonary vascular remodeling and lung cell apoptosis induced by the p53 pathway may new provide therapeutic targets.

Historical transition of management of sarcoidosis

Sarcoidosis is a systemic granulomatous disease of undetermined etiology, and it primarily affects the lungs and lymphatic system but may involve other organs. Recently, there have been several new insights in Japanese patients. The frequency of cardiac, ocular, and cutaneous sarcoidosis has increased in Japan, whereas, the proportion of patients with bilateral hilar lymphadenopathy decreased from 1960 to 2004. Propionibacterium acnes (P. acnes) has been studied extensively as one of the causative microorganism for granuloma formation, particularly in Japan. P. acnes-specific monoclonal antibodies are useful for diagnosing sarcoidosis. The potential association between smoking and sarcoidosis has been evaluated in a Japanese study, which found a higher prevalence of sarcoidosis among young smokers than that in previous reports. Recently, ¹⁸F-fluorodeoxyglucose positron-emission tomography, which permits visualization of activated inflammation, and endobronchial ultrasonography-guided transbronchial needle aspiration have been increasingly used to diagnose sarcoidosis. Cardiac sarcoidosis is found to be the main cause of death in Japan. The 2006 revised Japanese guidelines for diagnosing cardiac sarcoidosis are useful, particularly for subclinical cardiac sarcoidosis patients. Further studies and international communication and evaluation are needed to determine the causes of sarcoidosis, identify the risk factors for progressive disease, and develop new and effective treatments.

Primary pneumothorax: Should surgery be offered after the first episode?

Surgery is the recommended and most effective means of preventing the recurrence of primary spontaneous pneumothorax (PSP). However, the conventional belief amongst most clinicians is that surgery should not be routinely offered to patients with an uncomplicated first episode of PSP. The view that surgery should be reserved for recurrent episodes of ipsilateral PSP is based on an apprehension regarding traumatic thoracic surgery combined with a perception that recurrences after a single episode of PSP are unlikely. Modern advances in minimally invasive thoracic surgery have now dramatically reduced the morbidity of PSP surgery. Such surgery is now safe, effective and causes minimal indisposition for patients. On the other hand, modern clinical data suggests that recurrence rate of PSP is perhaps much higher than previously assumed, with more than half of patients experiencing a second episode within several years of the first. With such new appreciations of the current situation, it is appropriate to now consider offering surgery to patients even after the first episode of PSP.

Respiratory physiotherapy in gastroesophageal reflux disease: A review article

Gastroesophageal reflux disease (GERD) is a frequent disorder which is expensive to diagnose and treat. Initiating therapy with empiric trial of proton-pump inhibitor is a well established strategy; however, symptoms of GERD do often persist regardless of effective medication. Nowadays, increasing interest concerning the efficacy and safety of chronic acid suppression with proton-pump inhibitors (PPIs), prompts a consideration for GERD treatment strategies related to the basic physiology of the lower esophageal sphincter, including modulation of its tone and ending of spontaneous transient lower esophageal sphincter relaxation, which contributes to reflux. Together, the lower esophageal sphincter and the crural diaphragm represent the major antireflux barrier, protecting the esophagus from reflux of gastric content. In order to prevent the need for enduring PPIs therapy or surgical procedures, substitute therapeutics approaches are being researched. Recently, studies have focused on the response of the respiratory muscles to inspiratory muscle training. As a result, inspiratory muscle training has emerged as a potential alternative for treatment of gastroesophageal reflux. The present report reviews the physiologic factors contributing to GERD, and presents the newly developed therapies that can be applied either alone or in association with available efficient GERD therapy.

Update on the use of portable monitoring system for the diagnosis of sleep apnea in specific population

The prevalence and severity of obstructive sleep apnea (OSA) is higher in specific population: children, elderly, obese and patients with pulmonary and cardiovascular diseases, compared to the general population. OSA is associated with greater morbidity and mortality in these patients. Although full-night polysomnography is still the gold standard diagnostic sleep study for OSA, it is a time consuming, expensive and technically demanding exam. Over the last few years, there is growing evidence on the use of portable monitors (PM) as an alternative for the diagnosis of OSA. These devices were developed specially for sleep evaluation at home, at a familiar environment, with easy self-application of monitoring, unattended. The use of PM is stablished for populations with high pre-test probability of OSA. However, there is a lack of studies on the use of PM in age extremes and patients with comorbidities. The purpose of this review is to present the studies that evaluated the use of PM in specific population, as well as to describe the advantages, limitations and applications of these devices in this particular group of patients. Although the total loss rate of recordings is variable in different studies, the agreement with full-night polysomnography justifies the use of PM in this population.

New therapies for chronic obstructive pulmonary disease, lung regeneration

Chronic obstructive pulmonary disease (COPD) is characterized by the presence of airflow limitations that are not fully reversible and is a major cause of chronic morbidity and mortality worldwide. Although there has been extensive research examining the molecular mechanisms underlying the development of COPD, there is no proven clinically effective treatment for promoting recovery from established COPD. At present, regeneration is the only hope for a cure in patients with COPD. In this article, we review current treatments for COPD, focusing particularly on recent advances in lung regeneration based on two major approaches: regeneration-promoting agents and cell therapy. Retinoic acids are the major focus among regeneration-promoting agents, while mesenchymal stem cells are the main topic in the field of cell-based therapy. This article aims to provide valuable information for developing new therapies for COPD.

Pitfalls in spirometry: Clinical relevance

Spirometry is one of the functional tests most used in respiratory medicine to assess lung function in health and disease conditions. Its success is grounded on solid principles of lung mechanics that state that maximal flow on expiration is limited by the physical properties of airways and lung parenchyma. In contrast, on inspiration, flow depends on the force generated by the inspiratory muscles. Reduced expiratory forced flow and volumes usually reflect a deviation from health conditions. Yet due to a complex interplay of different obstructive and restrictive lung diseases within the multiple structural dimensions of the respiratory system, flows and volumes do not always perfectly reflect the impact of the disease on lung function. The present review is intended to shed light on a series of artefacts and biological phenomena that may confound the clinical interpretation of the main spirometric measurements. Among them is thoracic gas compression volume, the volume and time history of the inspiratory manoeuvre that precedes the forced expiration, the effects of heterogeneous distribution of the disease across the respiratory system, and the changes in lung elastic recoil.

Update on diagnosis and treatment of pulmonary alveolar microlithiasis

Pulmonary alveolar microlithiasis (PAM) (MIM265100) is a rare disease characterized by the diffuse deposit of microlithiasis in alveolar spaces. PAM could occur worldwide with high prevalence in Asia and Europe. Familial occurrence indicates its autosomal recessive trait and the SLC34A2 gene was identified as the responsible gene for the disease. In spite of the versatile mutation sites in patients from other countries, exon 7 and exon 8 might be the most liable gene in Chinese and Japanese patients. Most mutations caused the premature termination of proteins and produced truncated proteins, leading to the blocking of the recycling and degrading of outdated surfactant which is full of phospholipids. The most outstanding clinical feature of PAM is the discrepancy between the paucity of symptoms and the degree of pulmonary involvement. Diagnosis is easy to establish based on typical chest radiograph image and nuclear medicine improves its early diagnosis and active evaluation. Pathology of the unique intra-alveolar lamellar microliths gives strong support for diagnosis. No effective treatment is considered valid currently. However, lung transplantation is effective for advanced-stage patients, and long term treatment of disodium etidronate seems promising.

Sleep apnea and fatty liver disease: The growing link and management issues

Obstructive sleep apnea (OSA) is associated with metabolic, cardiovascular and neuropsychological disorders, with substantial morbidity and economic costs. OSA has been estimated to affect 4%-11% of the population, depending on age. Obesity is a significant risk factor for OSA. Non alcoholic fatty liver disease (NAFLD) has emerged as an integral component of the metabolic syndrome, with insulin resistance as the central pathogenic feature. Estimates based on imaging and autopsy studies suggest that about 20%-30% of adults in the United States and other Western countries have NAFLD. Evidence now suggests that NAFLD is independently correlated to insulin resistance regardless of adiposity. Some authors have suggested that OSA may be another contributor to NAFLD development. In complex diseases, several or many different genes interact with environmental factors in determining disease presence or its phenotype. Individual genes only have a small effect on disease risk and can therefore be very difficult to identify. The genetic and hormonal determinants of OSA and NAFLD have received little attention. A wide variety of intermediate phenotypes and genes are involved in OSA and NAFLD which makes this syndrome genetically complex. Various adipokines, the most important of which are leptin, adiponectin, tumor necrosis factor-alpha, resistin and interleukin-6, have a key role in NAFLD and OSA. Some studies have suggested that oxidative stress may also contribute to the development of NAFLD and OSA. Lifestyle intervention, insulin sensitizer drugs and bariatric surgery aim to improve metabolic syndrome, OSA and NAFLD but need further investigation.