COVID-19: Psychological distress, fear, and coping strategies among community members across the United Arab Emirates

BACKGROUND

The COVID-19 pandemic impacted the psychosocial well-being of the United Arab Emirates [UAE] population like other communities internationally.

OBJECTIVES

We aimed to identify the factors associated with psychological distress, fear, and coping amongst community members across the UAE.

METHODS

We conducted a cross-sectional online survey across the UAE during November 2020. Adults aged ≥18 years, living in the UAE who were able to respond to an online questionnaire in English or Arabic were considered eligible to participate in the study. We used standard validated tools to measure psychological distress, fear and coping. Kessler Psychological Distress Scale [K10] was used to assess psychological distress, Fear of COVID-19 Scale [FCV-19S] was used to assess the level of fear, and Brief Resilient Coping Scale [BRCS] was used to assess the coping strategies.

RESULTS

A total of 417 individuals participated in this study with a mean age of 29 [± 10.7] years. More than half of the participants experienced high to very high levels of psychological distress [55%] and a quarter experienced high levels of fear of COVID-19 [23.3%] with almost a third of them [36.2%] having low resilient coping. About 37.4% of the participants had work-related mental health impacts and 32.4% were perceived to have moderate to a great deal of distress due to a change of employment status during the pandemic. One in ten participants [9.4%] reported increased smoking. Increased smoking [AOR 8.66, 95% CIs 1.08-69.1,], increased alcohol drinking [AOR 2.39, 95% CIs 1.05-5.47] and higher levels of fear of COVID-19 [AOR 2.93, 95% CIs 1.83-4.67] were associated with moderate to very high levels of psychological distress. Being female [AOR 1.82, p = 0.030], having a pre-existing mental health condition [AOR 9.88, 95% p = 0.027], engaging in high-risk behaviors such as increased smoking [AOR 21.14, p = 0.003], increased alcohol drinking [AOR 1.48, p = 0.359] in the previous four weeks, and higher levels of fear of COVID-19 [AOR 4.18, p <0.001] were associated with moderate to very high levels of psychological distress. Also, being a smoker [AOR, 0.840, p = 0.011], and having a high level of fear [AOR 0.372, p = 0.001] were found to be associated with low resilient coping.

CONCLUSION

Community members in the UAE are at a higher risk of psychosocial distress and fear during the COVID-19 pandemic. Thus, healthcare providers and policymakers would need to be more alert to provide specific mental health support strategies for their wellbeing.

Liver, NAFLD and COVID-19

Coronavirus disease 2019 (COVID-19) is characterized by a wide clinical spectrum that includes abnormalities in liver function indicative of liver damage. Conversely, people with liver diseases are at higher risk of severe COVID-19. In the current review, we summarize first the epidemiologic evidence describing the bidirectional relationship between COVID-19 and liver function/liver diseases. Additionally, we present the most frequent histologic findings as well as the most important direct and indirect mechanisms supporting a COVID-19 mediated liver injury. Furthermore, we focus on the most frequent liver disease in the general population, non-alcoholic or metabolic-associated fatty liver disease (NAFLD/MAFLD), and describe how COVID-19 may affect NAFLD/MAFLD development and progression and conversely how NAFLD/MAFLD may further aggravate a COVID-19 infection. Finally, we present the long-term consequences of the pandemic on the development and management of NAFLD.

COVID-19 Infections in Gonads: Consequences on Fertility?

COVID-19 may influence human fertility and sexuality in several ways. Different cell types in gonads show a constitutive expression of angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine subtype 2 (TMPRSS2), which provide potential entry pathways for SARS-CoV-2. In addition to the biological effects of a COVID-19 infection on the gonads, the impact of the ongoing COVID-19 pandemic on mental health issues and sexual behavior may affect reproduction. This review summarizes the current knowledge on the influence of COVID-19 on the gonads and discusses possible consequences on human fertility. In this context, the close interaction between the hypothalamic-pituitary-adrenal axis and the hypothalamic-pituitary-gonadal axis in response to COVID-19-related stress is discussed. Some women noticed changes in their menstrual cycle during the COVID-19 pandemic, which could be due to psychological stress, for example. In addition, occasional cases of reduced oocyte quality and ovarian function are described after COVID-19 infection. In men, COVID-19 may cause a short-term decrease in fertility by damaging testicular tissue and/or impairing spermatogenesis. Moreover, decreased ratio testosterone/LH and FSH/LH in COVID-19 compared to aged-matched healthy men has been reported. Available data do not suggest any effect of the available SARS-CoV-2 vaccines on fertility. The effects of long COVID on human fertility have been reported and include cases with premature ovarian failure and oligomenorrhoea in women and erectile dysfunction in men. Despite the increasing knowledge about the effects of COVID-19 infections on human gonads and fertility, the long-term consequences of the COVID-19 pandemic cannot yet be assessed in this context.

Factors affecting patient reporting of adverse drug reactions: a systematic review

AIM

The aim of the present study was to determine the barriers and motives influencing consumer reporting of adverse drug reactions (ADRs).

METHODS

A systematic review, guided by the Cochrane Handbook, was conducted. Electronic searches included MEDLINE, EMBASE, PsycINFO, CINAHL, PubMed and the Cochrane Database of Systematic Reviews from 1964 to December 2014. Eligible studies addressed patients' perceptions and factors influencing ADR reporting. Studies about healthcare professional (HCP) reporting of ADRs were excluded. Studies were appraised for quality, and results were analysed descriptively.

RESULTS

Of 1435 citations identified, 21 studies were eligible. Studies were primarily conducted in the UK, the Netherlands and Australia. The identified barriers to patient reporting of ADRs (n = 15 studies) included poor awareness, confusion about who should report the ADR, difficulties with reporting procedures, lack of feedback on submitted reports, mailing costs, ADRs resolved and prior negative reporting experiences. The identified motives for patients reporting ADRs (n = 10 studies) were: preventing others from having similar ADRs, wanting personal feedback, improving medication safety, informing regulatory agencies, improving HCP practices, responding to HCPs not reporting their ADRs and having been asked to report ADRs by HCPs.

CONCLUSIONS

Most patients were not aware of reporting systems and others were confused about reporting. Patients were mainly motivated to make their ADRs known to prevent similar suffering in other patients. By increasing patient familiarity and providing clear reporting processes, reporting systems could better achieve patient reporting of ADRs.

Impact of switching from epoprostenol to IV treprostinil on treatment satisfaction and quality of life in patients with pulmonary hypertension

BACKGROUND

Transition from intravenous (IV) epoprostenol to IV treprostinil in patients with pulmonary hypertension (PH) has traditionally been performed by gradually decreasing the epoprostenol dose while increasing the treprostinil dose. Preliminary data suggest that this transition can be performed more rapidly without the need for epoprostenol weaning. We conducted a single center, prospective clinical trial to assess the safety, efficacy, and treatment satisfaction of rapidly switching from epoprostenol to IV treprostinil.

METHODS

This study included patients with PH who had rapidly transitioned from epoprostenol to IV treprostinil. Data collected included clinical status, adverse events, PH symptoms, and previously validated measures of quality of life and treatment satisfaction.

RESULTS

Ten patients were enrolled in this study. Exercise capacity measured by mean 6-min walk distance was maintained from baseline throughout follow-up. Severity of disease as assessed by WHO functional class was maintained or improved for the majority of patients. Adverse events were minimal during the transition, and all patients remained on IV treprostinil throughout the follow-up period. A favorable impact on quality of life and treatment satisfaction measures was observed by eight weeks following the transition from epoprostenol to IV treprostinil. Specifically, time spent on drug preparation activities decreased by 39.5% with treprostinil compared to epoprostenol.

CONCLUSIONS

Rapidly switching from epoprostenol to IV treprostinil can be achieved without safety concerns, with minimal patient monitoring and without the need for extended hospitalization, while favorably impacting on patients' quality of life.

Smart sensor systems for human health breath monitoring applications

Breath analysis techniques offer a potential revolution in health care diagnostics, especially if these techniques can be brought into standard use in the clinic and at home. The advent of microsensors combined with smart sensor system technology enables a new generation of sensor systems with significantly enhanced capabilities and minimal size, weight and power consumption. This paper discusses the microsensor/smart sensor system approach and provides a summary of efforts to migrate this technology into human health breath monitoring applications. First, the basic capability of this approach to measure exhaled breath associated with exercise physiology is demonstrated. Building from this foundation, the development of a system for a portable asthma home health care system is described. A solid-state nitric oxide (NO) sensor for asthma monitoring has been identified, and efforts are underway to miniaturize this NO sensor technology and integrate it into a smart sensor system. It is concluded that base platform microsensor technology combined with smart sensor systems can address the needs of a range of breath monitoring applications and enable new capabilities for healthcare.

Sensitive cardiac troponin I predicts poor outcomes in pulmonary arterial hypertension

Circulating cardiac troponins are markers of myocardial injury. We sought to determine whether cardiac troponin I (cTnI), measured by a sensitive assay, is associated with disease severity and prognosis in pulmonary arterial hypertension (PAH). cTnI was measured in 68 patients with PAH diagnostic category 1 in a research-based sensitive immunoanalyser with a lower limit of detection of 0.008 ng · mL(-1). The associations between cTnI and PAH severity and clinical outcomes were assessed using Chi-squared and Wilcoxon rank sum tests, Kaplan-Meier analysis and Cox regression models. cTnI was detected in 25% of patients. Patients with detectable cTnI had more advanced functional class symptoms, a shorter 6-min walk distance, more pericardial effusions, larger right atrial area, and higher B-type natriuretic peptide and C-reactive protein levels. 36-month transplant-free survival was 44% in patients with detectable cTnI versus 85% in those with undetectable cTnI. cTnI was associated with a 4.7-fold increased risk of death related to right ventricular failure or transplant (hazard ratio 4.74, 95% CI 1.89-11.89; p<0.001), even when adjusted individually for known parameters of PAH severity. Elevated plasma cTnI, even at subclinically detectable levels, is associated with more severe disease and worse outcomes in patients with PAH.

Exhaled nitric oxide in asthma in adults: the end is the beginning?

Approximately 20 years after the initial report of the measurement of exhaled nitric oxide (NO) in the exhaled air of humans, numerous publications have evaluated the possible applications of the fraction of exhaled NO (FeNO) in patients with asthma. The aim of the present review is to evaluate the technical issues and confounding factors related to FeNO measurements, as well as the role of FeNO in the diagnosis of asthma, the evaluation of asthmatic patients and the guidance of treatment. Several other issues, including the pursuit for "normal" and best personal values, the prediction of clinically relevant asthma outcomes and the identification of asthma phenotypes and future directions are discussed. FeNO represents the only exhaled biomarker that has reached clinical practice even in primary care settings and this review provides a critical view of the possible applications of this biomarker, both for the basic researcher and the clinician.

Effect of the influenza A (H1N1) live attenuated intranasal vaccine on nitric oxide (FE(NO)) and other volatiles in exhaled breath

For the 2009 influenza A (H1N1) pandemic, vaccination and infection control were the main modes of prevention. A live attenuated H1N1 vaccine mimics natural infection and works by evoking a host immune response, but currently there are no easy methods to measure such a response. To determine if an immune response could be measured in exhaled breath, exhaled nitric oxide (FE(NO)) and other exhaled breath volatiles using selected ion flow tube mass spectrometry (SIFT-MS) were measured before and daily for seven days after administering the H1N1 2009 monovalent live intranasal vaccine (FluMist®, MedImmune LLC) in nine healthy healthcare workers (age 35 ± 7 years; five females). On day 3 after H1N1 FluMist® administration there were increases in FE(NO) (MEAN±SEM: day 0 15 ± 3 ppb, day 3 19 ± 3 ppb; p < 0.001) and breath isoprene (MEAN±SEM: day 0 59 ± 15 ppb, day 3 99 ± 17 ppb; p = 0.02). MS analysis identified the greatest number of changes in exhaled breath on day 3 with 137 product ion masses that changed from baseline. The exhaled breath changes on day 3 after H1N1 vaccination may reflect the underlying host immune response. However, further work to elucidate the sources of the exhaled breath changes is necessary.

Biomarkers in exhaled breath condensate: a review of collection, processing and analysis

Exhaled breath condensate (EBC) is a potential rich source for countless biomarkers that can provide valuable information about respiratory as well as systemic diseases. EBC has been studied in a variety of diseases including allergic rhinitis, asthma, chronic obstructive lung disease, cystic fibrosis, lung cancer, and obstructive sleep apnea syndrome. Although numerous biomarkers have been discovered and studied in EBC, the methods of collection and biomarker detection have not been fully standardized. While leaving standardization methods up to individual labs for the present time is optimal for the continued discovery of new biomarkers in EBC, this decreases the reproducibility and generalizability of the findings. In this review we will discuss specific biomarkers studied in specific diseases as well as some of the related technical issues including collection, processing and analysis.

Exhaled breath condensate: methodological recommendations and unresolved questions

Collection of exhaled breath condensate (EBC) is a noninvasive method for obtaining samples from the lungs. EBC contains large number of mediators including adenosine, ammonia, hydrogen peroxide, isoprostanes, leukotrienes, nitrogen oxides, peptides and cytokines. Concentrations of these mediators are influenced by lung diseases and modulated by therapeutic interventions. Similarly EBC pH also changes in respiratory diseases. The aim of the American Thoracic Society/European Respiratory Society Task Force on EBC was to identify the important methodological issues surrounding EBC collection and assay, to provide recommendations for the measurements and to highlight areas where further research is required. Based on the currently available evidence and the consensus of the expert panel for EBC collection, the following general recommendations were put together for oral sample collection: collect during tidal breathing using a noseclip and a saliva trap; define cooling temperature and collection time (10 min is generally sufficient to obtain 1-2 mL of sample and well tolerated by patients); use inert material for condenser; do not use resistor and do not use filter between the subject and the condenser. These are only general recommendations and certain circumstances may dictate variation from them. Important areas for future research involve: ascertaining mechanisms and site of exhaled breath condensate particle formation; determination of dilution markers; improving reproducibility; employment of EBC in longitudinal studies; and determining the utility of exhaled breath condensate measures for the management of individual patients. These studies are required before recommending this technique for use in clinical practice.

High levels of nitric oxide in individuals with pulmonary hypertension receiving epoprostenol therapy

Lack of vasodilator substances, such as nitric oxide (NO), has been implicated in the development of pulmonary hypertension, but the pathogenesis of the disease remains speculative. We hypothesized that NO plays a role in the pathogenesis of primary pulmonary hypertension (PPH), and may serve as a sensitive and specific marker of disease progression and/or severity. To test this, exhaled NO and pulmonary artery pressure were measured in individuals with PPH and secondary pulmonary hypertension (SPH) on various therapies, including the potent vasodilator epoprostenol (prostacyclin), compared with healthy controls. NO in exhaled breath of individuals with PPH was lower than SPH or control (p<0.05). In contrast, exhaled NO of individuals with PPH or SPH receiving epoprostenol was strikingly higher than PPH or SPH individuals not receiving epoprostenol, or controls. Concomitant with higher NO levels, right ventricular systolic pressure of individuals significantly decreased with epoprostenol. Importantly, in paired measures of exhaled NO before and after epoprostenol, NO increased in all pulmonary hypertensive individuals 24 h after initiation of epoprostenol therapy (p<0.05). NO may be a useful noninvasive marker of pulmonary hypertension severity and response to prostacyclin therapy.

Alterations in exhaled gas profile during allergen-induced asthmatic response

The source of exhaled carbon monoxide (CO) and the relationship to airway inflammation are not clear. If CO is produced by the inflamed airway, we hypothesized that inflammation induced by allergen challenge would increase exhaled CO of atopic asthmatics. Eight atopic asthmatics underwent whole lung allergen challenge. CO, nitric oxide (NO), oxygen, and carbon dioxide (CO(2)) were measured simultaneously in exhaled breath which was collected into Mylar balloons before (baseline), immediately after, and at subsequent times after allergen. NO was higher in asthmatics than control subjects at baseline, increased further in seven of the eight asthmatics after allergen, and was inversely correlated to specific conductance. In contrast, exhaled CO of asthmatics was not higher than that of control individuals at baseline, decreased immediately after allergen, and returned to baseline levels during the late asthmatic response. Thus, allergen-induced airway inflammation did not lead to increased exhaled CO in asthma.

Major histocompatibility locus genetic markers of beryllium sensitization and disease

Hypersensitivity to beryllium (Be) is found in 1-16% of exposed workers undergoing immunological screening for beryllium disease using the beryllium lymphocyte proliferation test (BeLPT). However, only approximately 50% of BeLPT-positive workers present with lung granulomas (i.e. berylliosis). As berylliosis is associated with the human leukocyte antigen (HLA)-DP supratypic marker DPGlu69, the authors asked whether this marker is differentially associated with disease presentation. A population of 639 workers from a beryllium factory undergoing BeLPT screening was evaluated in a nested case-control study for the prevalence of HLA-DPGlu69, the HLA-DPB1, HLA-DQ and HLA-DR alleles and of the biallelic tumour necrosis factor (TNF)-alpha polymorphism TNF-alpha-308 in 23 individuals presenting as "sensitized" (i.e. BeLPT-positive without lung granulomas) and in 22 presenting as "diseased" (i.e. BeLPT-positive with granulomas in the lung biopsy). The HLA-DPGlu69 marker was associated with "disease" (odds ratio (OR) 3.7, p=0.016, 95% confidence interval (CI) 1.4-10.0), whilst the high TNF-alpha production-related TNF-alpha-308*2 marker was associated with both a positive BeLPT (OR 7.8, corrected p<0.0001, 95% CI 3.2-19.1) with no difference between "sensitization" and "disease". Furthermore, the HLA-DRArg74 marker was associated with "sensitization" without disease (OR 3.96, p=0.005, 95%, CI 1.5-10.1). The data indicate that tumour necrosis factor-alpha, human leukocyte antigen-DR and human leukocyte antigen-DP markers play different roles in beryllium sensitization and granuloma formation in beryllium-exposed workers.

Drug-induced lung disease

Drug-induced lung disease is a major source of iatrogenic injury. We review the various drugs known to induce injury and the various patterns of injury seen.

The promise and reality of nitric oxide in the diagnosis and treatment of lung disease

Endogenously produced nitric oxide plays a major role in lung physiology and pathology. Inhaled nitric oxide given exogenously has been studied extensively as a treatment for many lung diseases, and the results suggest that it may help improve oxygenation in some patients. Several issues need to be addressed, however, before it can be used in routine clinical practice.

High levels of exhaled nitric oxide (NO) and NO synthase III expression in lesional smooth muscle in lymphangioleiomyomatosis

Smooth-muscle proliferation is the hallmark of lymphangioleiomyomatosis (LAM). Although little is known about the pathogenesis of LAM, nitric oxide (NO) is a key regulator of smooth-muscle proliferation. NO is linked to the pathogenesis of other lung diseases such as asthma, in part by the finding of higher-than-normal levels of exhaled NO. If NO were involved in the abnormal smooth-muscle proliferation in LAM, we reasoned that exhaled NO from individuals with LAM would also differ from that of healthy control subjects. To evaluate this hypothesis, we studied exhaled NO in individuals with LAM in comparison with healthy and asthmatic women using a chemiluminescent NO analyzer. Women with LAM had higher exhaled NO than did healthy women but lower than asthmatic women (NO [parts per billion] median (25 to 75%): LAM 8 [7 to 15] [n = 28], control 6 [5 to 8] [n = 21], asthma 14 [8 to 25] [n = 22]; Kruskal-Wallis P < 0.001). Immunohistochemical studies on formalin-fixed, paraffin-embedded sections of surgical and autopsy material from lungs of individuals with LAM showed diffuse NO synthase III (NOSIII) expression in the lesional smooth muscle of LAM similar to that in the vascular endothelium. NOSIII expression was limited to the vascular endothelium and bronchial smooth muscle in healthy control lungs. The increased NO and the presence of NOSIII expression in lesional smooth muscle warrants further study into the potential role for NO in the pathogenesis of LAM.

NO chemical events in the human airway during the immediate and late antigen-induced asthmatic response

A wealth of evidence supports increased NO (NO.) in asthma, but its roles are unknown. To investigate how NO participates in inflammatory airway events in asthma, we measured NO. and NO. chemical reaction products [nitrite, nitrate, S-nitrosothiols (SNO), and nitrotyrosine] before, immediately and 48 h after bronchoscopic antigen (Ag) challenge of the peripheral airways in atopic asthmatic individuals and nonatopic healthy controls. Strikingly, NO(3)(-) was the only NO. derivative to increase during the immediate Ag-induced asthmatic response and continued to increase over 2-fold at 48 h after Ag challenge in contrast to controls [P < 0.05]. NO(2)(-) was not affected by Ag challenge at 10 min or 48 h after Ag challenge. Although SNO was not detectable in asthmatic airways at baseline or immediately after Ag, SNO increased during the late response to levels found in healthy controls. A model of NO. dynamics derived from the current findings predicts that NO. may have harmful effects through formation of peroxynitrite, but also subserves an antioxidant role by consuming reactive oxygen species during the immediate asthmatic response, whereas nitrosylation during the late asthmatic response generates SNO, safe reservoirs for removal of toxic NO. derivatives.

A 65-year-old factory worker with dyspnea on exertion and a normal chest x-ray

Chronic beryllium disease is an occupationally acquired granulomatous lung disease similar to sarcoidosis. It is caused by exposure to beryllium in genetically susceptible persons. It should be suspected in patients with beryllium exposure who present with pulmonary symptoms or have a positive screening blood beryllium-specific lymphocyte proliferation test. The diagnosis is confirmed by the finding of granulomas on transbronchial biopsy in the appropriate clinical and epidemiologic setting. Although there is no cure, treatment with corticosteroids is usually beneficial. In view of the potential side effects, treatment is reserved for patients with symptoms or a decline in pulmonary function.

Molecular mechanisms of increased nitric oxide (NO) in asthma: evidence for transcriptional and post-translational regulation of NO synthesis

Evidence supporting increased nitric oxide (NO) in asthma is substantial, although the cellular and molecular mechanisms leading to increased NO are not known. Here, we provide a clear picture of the events regulating NO synthesis in the human asthmatic airway in vivo. We show that human airway epithelium has abundant expression of NO synthase II (NOSII) due to continuous transcriptional activation of the gene in vivo. Individuals with asthma have higher than normal NO concentrations and increased NOSII mRNA and protein due to transcriptional regulation through activation of Stat1. NOSII mRNA expression decreases in asthmatics receiving inhaled corticosteroid, treatment effective in reducing inflammation in asthmatic airways. In addition to transcriptional mechanisms, post-translational events contribute to increased NO synthesis. Specifically, high output production of NO is fueled by a previously unsuspected increase in the NOS substrate, l -arginine, in airway epithelial cells of asthmatic individuals. Finally, nitration of proteins in airway epithelium provide evidence of functional consequences of increased NO. In conclusion, these studies define multiple mechanisms that function coordinately to support high level NO synthesis in the asthmatic airway. These findings represent a crucial cornerstone for future therapeutic strategies aimed at regulating NO synthesis in asthma.

Eosinophils generate brominating oxidants in allergen-induced asthma

Eosinophils promote tissue injury and contribute to the pathogenesis of allergen-triggered diseases like asthma, but the chemical basis of damage to eosinophil targets is unknown. We now demonstrate that eosinophil activation in vivo results in oxidative damage of proteins through bromination of tyrosine residues, a heretofore unrecognized pathway for covalent modification of biologic targets in human tissues. Mass spectrometric studies demonstrated that 3-bromotyrosine serves as a specific "molecular fingerprint" for proteins modified through the eosinophil peroxidase-H(2)O(2) system in the presence of plasma levels of halides. We applied a localized allergen challenge to model the effects of eosinophils and brominating oxidants in human lung injury. Endobronchial biopsy specimens from allergen-challenged lung segments of asthmatic, but not healthy control, subjects demonstrated significant enrichments in eosinophils and eosinophil peroxidase. Baseline levels of 3-bromotyrosine in bronchoalveolar lavage (BAL) proteins from mildly allergic asthmatic individuals were modestly but not statistically significantly elevated over those in control subjects. After exposure to segmental allergen challenge, lung segments of asthmatics, but not healthy control subjects, exhibited a >10-fold increase in BAL 3-bromotyrosine content, but only two- to threefold increases in 3-chlorotyrosine, a specific oxidation product formed by neutrophil- and monocyte-derived myeloperoxidase. These results identify reactive brominating species produced by eosinophils as a distinct class of oxidants formed in vivo. They also reveal eosinophil peroxidase as a potential therapeutic target for allergen-triggered inflammatory tissue injury in humans.

Hypertensive urgency induced by an interaction of mirtazapine and clonidine

Mirtazapine is a new antidepressant with a tetracyclic chemical structure that is not related to selective serotonin reuptake inhibitors, tricyclic antidepressants, or monoamine oxidase inhibitors. The antidepressant effect results from stimulation of the noradrenergic system through antagonism at central (alpha2-inhibitory receptors. Clonidine exerts its antihypertensive effect by stimulating these receptors to cause a reduction in endogenous release of norepinephrine. Therefore, the two agents have mechanisms of action that potentially oppose one another. We report a case of hypertensive urgency that ensued after a patient stabilized on clonidine began taking mirtazapine.

Primary pulmonary hypertension: update on pathogenesis and novel therapies

Primary pulmonary hypertension is a progressive and fatal disease that chiefly affects young adults. Although its etiology is a mystery, recent research has uncovered several biochemical derangements in this disorder, and new therapies are prolonging survival.

Rapid loss of superoxide dismutase activity during antigen-induced asthmatic response

Loss of superoxide dismutase activity occurs within minutes of an acute asthmatic response to segmental antigen instillation into the lung of individuals with atopic asthma. Decreased activity undoubtedly contributes to airway inflammation and injury through increased formation of reactive oxygen and nitrogen species, and suggests that enrichment of lung antioxidants is therapeutic for asthma.

Nitric oxide regulation of asthmatic airway inflammation with segmental allergen challenge

BACKGROUND

Despite evidence of increased nitric oxide (NO) in asthmatic compared with healthy individuals, the role of NO in airway inflammation is unclear.

OBJECTIVE

The purpose of the study was to determine the in vivo effects of localized allergen challenge on airway NO levels and transcription factor activation.

METHODS

In this study localized allergen challenge was used as a model of asthmatic exacerbation to determine the relationship of NO to airway inflammation.

RESULTS

With allergen challenge, asthmatic patients had a rise in airway NO levels, whereas NO levels in healthy controls did not change. The increased NO in asthma with allergen challenge compared with healthy control subjects was associated with an increase in inflammatory cytokines (GM-CSF and macrophage inflammatory protein-1) in epithelial lining fluid and eosinophilic infiltrate in bronchoalveolar lavage fluid (BAL) and biopsy specimens. To investigate the mechanisms of cytokine gene expression, activation of the transcription factors activator protein-1 and nuclear factor-kappaB (NF-kappaB) in cells from BAL were evaluated. Activator protein-1 was not activated before or after local allergen challenge. In contrast, NF-kappaB activation was less in BAL cells from asthmatic patients with increased NO in comparison with controls.

CONCLUSION

Our studies are the first to suggest an inverse correlation between NF-kappaB and airway NO in a localized segmental allergen challenge model in allergic asthmatic patients. The current study demonstrates that activation of the inflammatory response (eg, cytokines, cellular infiltrate) in allergic asthmatic patients is temporally associated with increased airway NO. We propose that NO that is up-regulated by cytokines is part of an autoregulatory feedback loop (ie, allergen challenge stimulates inflammatory cytokine production, which in turn stimulates NO production, and NO down-regulates cytokine production).

High prevalence of hypothyroidism in patients with primary pulmonary hypertension

PURPOSE

To characterize the prevalence of hypothyroidism in a population with primary pulmonary hypertension (PPH).

METHODS

Retrospective record review of 41 patients with PPH seen between 1991 and 1997 at a tertiary care center. Data abstracted included: history of previous thyroid disease, intake of thyroid supplement, and thyroid function tests. Hypothyroidism was defined as a serum thyroid stimulating hormone (TSH) level higher than 5.5 U/L, intake of thyroid supplement, or low serum thyroxine level.

RESULTS

Of the 40 patients with PPH included in the study (11 men and 29 women), ages ranged from 11 to 76 years (mean 43.5 years). The mean pulmonary artery pressure was 58.7 mm Hg. Thirty-three patients had normal serum TSH levels (3 of whom were on levothyroxine supplement); 1 had low TSH; 5 had high TSH (range, 6.8-9.9 U/L, mean 8.4 U/L), and 1 had low thyroxine (T4 < 1.0 microg/dL). Nine of 40 patients (22.5%) had evidence of hypothyroidism, which is much more than expected in the general population of similar age range (2.8% in men, 7.5% in women) (p = 0.002).

CONCLUSIONS

The prevalence of hypothyroidism in patients with PPH is high (22.5%). Patients with PPH should be investigated for the possibility of coexisting hypothyroidism.

Venous thromboembolism in the intensive care unit

Venous thromboembolic disease has emerged as a significant cause of morbidity and mortality in hospitalized patients. This article reviews the salient features of venous thromboembolism as they pertain to the critically ill. Emphasis is placed on identifying risk factors, diagnostic strategies, prophylaxis, and treatment of this disorder. Deep venous thrombosis and pulmonary embolism, both being manifestations of the same disease processes, are considered together in this discussion of venous thromboembolism.

Human vascular endothelial cells express oxytocin receptors

Pharmacological studies in humans and animals suggest the existence of vascular endothelial vasopressin (AVP)/oxytocin (OT) receptors that mediate a vasodilatory effect. However, the nature of the receptor subtype(s) involved in this vasodilatory response remains controversial, and its coupled intracellular pathways are unknown. Thus, we set out to determine the type and signaling pathways of the AVP/OT receptor(s) expressed in human vascular endothelial cells (ECs). Saturation binding experiments with purified membranes of primary cultures of ECs from human umbilical vein (HUVEC), aorta (HAEC), and pulmonary artery (HPAEC) and [3H]AVP or [3H]OT revealed the existence of specific binding sites with a greater affinity for OT than AVP (Kd = 1.75 vs. 16.58 nM). Competition binding experiments in intact HUVECs (ECV304 cell line) with the AVP antagonist [125I]4-hydroxyphenacetyl-D-Tyr(Me)-Phe-Gln-Asn-Arg-Pro-Arg-NH2 or the OT antagonist [125I]D(CH2)5[O-Me-Tyr-Thr-Orn-Tyr-NH2]vasotocin, and various AVP/OT analogs confirmed the existence of a single class of surface receptors of the classical OT subtype. RT-PCR experiments with total RNA extracted from HUVEC, HAEC, and HPAEC and specific primers for the human V1 vascular, V2 renal, V3 pituitary, and OT receptors amplified the OT receptor sequence only. No new receptor subtype could be amplified when using degenerate primers. DNA sequencing of the coding region of the human EC OT receptor revealed a nucleotide sequence 100% homologous to that of the uterine OT receptor reported previously. Stimulation of ECs by OT produced mobilization of intracellular calcium and the release of nitric oxide that was prevented by chelation of extra- and intracellular calcium. No stimulation of cAMP or PG production was noted. Finally, OT stimulation of ECs led to a calcium- and protein kinase C-dependent cellular proliferation response. Thus, human vascular ECs express OT receptors that are structurally identical to the uterine and mammary OT receptors. These endothelial OT receptors produce a calcium-dependent vasodilatory response via stimulation of the nitric oxide pathway and have a trophic action.

Role of bronchoscopy in asthma research

Over the past 15 years, much has been learned about the presence of airway inflammation in asthma through the use of investigative bronchoscopy. It has become quite clear that inflammation is present even in mild asthma. In addition to the eosinophils, T-lymphocytes and a variety of cytokines have been identified to play a prominent role in asthmatic inflammation. The concept of delayed asthmatic response after allergen exposure and its relationship to cellular inflammation and airway hyper-reactivity has become more clearly established. Our understanding of asthmatic airway inflammation, however, is incomplete. As interesting as the database has been so far, investigative FB has not defined a unique profile for patients with asthma. Specifically, lavage or endobronchial biopsy has not identified parameters that help in the diagnosis, assessment of disease severity, prognosis, or likelihood to respond to specific therapies. Also, the exact relationship between parameters in lavage compared with mucosal biopsy and how these are related to airway hyper-reactivity and the clinical syndrome of asthma remains poorly understood. In this regard, it must be confessed that currently FB with lavage and biopsy in asthmatics needs to be considered as a research tool for specimen retrieval to help characterize and express inflammation. Although these techniques have contributed immensely to our understanding of asthma pathogenesis, presently these techniques do not have any practical role or clinical usefulness.

Role of bronchoscopy in massive hemoptysis

Massive hemoptysis accounts for a minority of all patients with hemoptysis but poses a major challenge for the acute and long-term treatment. Massive hemoptysis can lead to asphyxiation and airway obstruction, shock, and exsanguination. Bronchoscopy plays an integral part in managing massive hemoptysis in diagnosis and treatment (Table 5). Specifically, bronchoscopy allows lateralization and more specific localization of bleeding that is critically important for effective management. Furthermore, acute control of bleeding can sometimes be achieved with instruments and catheters placed through the bronchoscope or by agents instilled into the airways through the bronchoscope.

Future of flexible bronchoscopy

Despite some potential "threats" (Table 3), the future of bronchoscopy is likely full with ever expanding applications in clinical medicine and research (Tables 1 and 2). The role of bronchoscopy in lung cancer continues to expand and the usefulness of newer techniques needs to be established. The role of FB is also ever expanding in the immuno compromised host and critically ill patients. Future studies, however, should concentrate on patient outcome, especially survival and performance status. Therapeutic bronchoscopy has been extended to many areas and the emphasis of future research will likely continue to be at the molecular level rather than on studies of better instruments for retrieval purposes. The most exciting developments are likely to be in the field of gene therapy, which has made remarkable progress in the past decade. Gene therapy can be a powerful technology, but several hurdles must be overcome to make gene therapy a reality for treating human disease in the future. As the cost of technology continues to challenge health care delivery systems, a major challenge for the future of bronchoscopy is to evaluate new technologies and applications based on their impact on patient outcome, survival, and management of cost.

Manifestations of scleroderma pulmonary disease

Scleroderma is a multisystem disease of unknown cause characterized by synthesis and deposition of excessive extracellular matrix and vascular anti-GBM antibodies, leading to pulmonary hemorrhage and glomerulonephritis with rapidly progressive renal insufficiency. Recent advances in the understanding of disease pathogenesis and diagnosis and treatment have significantly improved our ability to recognize the syndrome, distinguish it from other similar disorders, and offer successful treatment. This article focuses on the pathogenetic features, clinical manifestations, diagnostic strategies, and therapeutic principles of anti-GBM disease.

Biochemical reaction products of nitric oxide as quantitative markers of primary pulmonary hypertension

Primary pulmonary hypertension (PPH) is a rare and fatal disease of unknown etiology. Inflammatory oxidant mechanisms and deficiency in nitric oxide (NO) have been implicated in the pathogenesis of pulmonary hypertension. In order to investigate abnormalities in oxidants and antioxidants in PPH, we studied intrapulmonary NO levels, biochemical reaction products of NO, and antioxidants (glutathione [GSH], glutathione peroxidase [GPx], and superoxide dismutase [SOD]) in patients with PPH (n = 8) and healthy controls (n = 8). Intrapulmonary gases and fluids were sampled at bronchoscopy. Pulmonary hypertension was determined by right-heart catheterization. NO and biochemical reaction products of NO in the lung were decreased in PPH patients in comparison with healthy controls (NO [ppb] in airway gases: control, 8 +/- 1; PPH, 2.8 +/- 0. 9; p = 0.016; and NO products [microM] in bronchoalveolar lavage fluid [BALF]: control, 3.3 +/- 1.05; PPH, 0.69 +/- 0.21; p = 0.03). However, GSH in the lungs of PPH patients was higher than in those of controls (GSH [microM] in BALF: 0.55 +/- 0.04; PPH, 0.9 +/- 0.1; p = 0.015). SOD and GPx activities were similar in the two groups (p >/= 0.50). Biochemical reaction products of NO were inversely correlated with pulmonary artery pressures (R = -0.713; p = 0.047) and with years since diagnosis of PPH (R = -0.776; p = 0.023). NO reaction products are formed through interactions between oxidants and NO, with the end products of reaction dependent upon the relative levels of the two types of molecules. The findings of the study therefore show that NO and oxidant reactions in the lung are related to the increased pulmonary artery pressures in PPH.

iNOS expression in human intestinal microvascular endothelial cells inhibits leukocyte adhesion

Increased nitric oxide (NO) production by inducible nitric oxide synthase (iNOS) has been associated with intestinal inflammation, including human inflammatory bowel disease. However, NO can downregulate endothelial activation and leukocyte adhesion, critical steps in the inflammatory response. Using primary cultures of human intestinal microvascular endothelial cells (HIMEC), we determined the role of NO in the regulation of HIMEC activation and interaction with leukocytes. Both nonselective (NG-monomethyl-L-arginine) and specific (N-iminoethyl-L-lysine) competitive inhibitors of iNOS significantly increased binding of leukocytes by HIMEC activated with cytokines and lipopolysaccharide. Increased adhesion was reversible with the NOS substrate L-arginine and was not observed in human umbilical vein endothelial cells (HUVEC). Activation of HIMEC significantly upregulated HIMEC iNOS expression and NO production. NOS inhibitors did not augment cell adhesion molecule levels in activated HIMEC but did result in sustained increases in intracellular reactive oxygen species. In addition, antioxidant compounds reversed the effect of NOS inhibitors on HIMEC-leukocyte interaction. Taken together, these data suggest that after HIMEC activation, iNOS-derived NO is an endogenous antioxidant, downregulating leukocyte binding and potentially downregulating intestinal inflammation.

Nitric oxide synthesis in the lung. Regulation by oxygen through a kinetic mechanism

In this study, we show that oxygen regulates nitric oxide (NO) levels through effects on NO synthase (NOS) enzyme kinetics. Initially, NO synthesis in the static lung was measured in bronchiolar gases during an expiratory breath-hold in normal individuals. NO accumulated exponentially to a plateau, indicating balance between NO production and consumption in the lung. Detection of NO2-, NO3-, and S-nitrosothiols in lung epithelial lining fluids confirmed NO consumption by chemical reactions in the lung. Interestingly, alveolar gas NO (estimated from bronchiolar gases at end-expiration) was near zero, suggesting NO in exhaled gases is not derived from circulatory/systemic sources. Dynamic NO levels during tidal breathing in different airway regions (mouth, trachea, bronchus, and bronchiole) were similar. However, in individuals breathing varying levels of inspired oxygen, dynamic NO levels were notably dependent on O2 concentration in the hypoxic range (KmO2 190 microM). Purified NOS type II enzyme activity in vitro was similarly dependent on molecular oxygen levels (KmO2 135 microM), revealing a means by which oxygen concentration affects NO levels in vivo. Based upon these results, we propose that NOS II is a mediator of the vascular response to oxygen in the lung, because its KmO2 allows generation of NO in proportion to the inspired oxygen concentration throughout the physiologic range.

Inhaled corticosteroids and beta-agonists inhibit oxidant production by bronchoalveolar lavage cells from normal volunteers in vivo

To study the anti-inflammatory mechanisms of inhaled corticosteroids and beta-agonist therapies, we evaluated basal and stimulus-induced superoxide production by human airway inflammatory cells obtained by bronchoalveolar lavage from normal volunteers before and after 3 weeks of an inhaled corticosteroid (flunisolide) and beta-agonist (metaproterenol). Assay of superoxide production by the bronchoalveolar lavage cells was performed in the presence of media alone or media containing phorbol ester by optical density determination of reduced ferricytochrome c at 550 nm. Interleukin-1 beta released from unstimulated cells and cells stimulated with lipopolysaccharide was quantitated by enzyme immunoassay. Interestingly, phorbol ester-stimulated superoxide production was strikingly inhibited (P < 0.05) by inhaled therapies, while stimulus induced Interleukin-1 beta production was not significantly affected (P = 0.12). Suppression of oxidant production by airway inflammatory cells may be a major mechanism for the beneficial anti-inflammatory effects of inhaled corticosteroids and beta-agonists.

Interferon gamma and interleukin 4 stimulate prolonged expression of inducible nitric oxide synthase in human airway epithelium through synthesis of soluble mediators

Human respiratory epithelium expresses inducible nitric oxide synthase (iNOS) continuously in vivo, however mechanisms responsible for maintenance of expression are not known. We show that IFNgamma is sufficient for induction of iNOS in primary human airway epithelial cells (HAEC) in vitro, and IL-4 potentiates IFNgamma-induced iNOS expression in HAEC through stabilization of iNOS mRNA. IFNgamma/IL-4- induced iNOS expression in HAEC was delayed in onset and prolonged with expression up to 1 wk. Removal of overlying culture media resulted in loss of expression, while transfer of conditioned media induced iNOS mRNA in other HAEC. IFNgamma and IL-4 stimulation activated STAT1 and STAT6 in HAEC, but conditioned media transfer to HAEC produced even higher levels of STAT1 activation than achieved by direct addition of cytokines. Although cytokine induction of iNOS was dependent on new protein synthesis, conditioned media induction of iNOS in HAEC was not. Further, removal of overlying culture media from cells at different times after cytokine stimulation demonstrated that mediator synthesis and/or secretion important for induction and maintenance of iNOS occurs early after cytokine stimulation. In conclusion, a combination of IFNgamma/ IL-4, which occurs naturally in the lung epithelial lining fluid, leads to maintenance of iNOS expression in human airway epithelium through production of soluble mediators and stabilization of mRNA.

Alveolar hemorrhage in patients with rheumatic disease

Alveolar hemorrhage is an uncommon event that is associated with several underlying disorders, many of which are immunologically mediated. Careful evaluation of basic laboratory tests, extrapulmonary physical findings, and serology usually leads to the correct diagnosis. Significant overlap, however, exists, and pathologic (especially immunopathologic) evaluation of pulmonary or renal biopsies may be necessary. An accurate diagnosis is essential because treatment is most helpful when directed at the underlying diagnosis. Supportive therapy may be needed until the underlying disease is diagnosed and specific therapy is initiated.

Analysis of the safety of bronchoscopy after recent acute myocardial infarction

Acute myocardial infarction (AMI) is generally considered to increase the risk of flexible fiberoptic bronchoscopy (FFB). Currently, to our knowledge, no data in the literature support or challenge this concept. We conducted a retrospective chart review for the years 1986 to 1994 of 20 patients (14 men) who underwent 21 FFBs while hospitalized for an AMI. The mean age was 63.8 years (range, 38 to 83 years). Ten patients underwent revascularization procedures (eight coronary artery bypass grafting and two percutaneous transluminal coronary angioplasty) before FFB. The mean period between the AMI and FFB was 11.7 days (range, 1 to 30 days). Indications for FFB were pulmonary infiltrate (n = 10), hemoptysis (n = 6), atelectasis (n = 4), and to localize a suspected bronchopleural fistula (n = 1). Procedures performed included airway examination (21), BAL (12), transbronchial biopsy (2), endobronchial biopsy (3), and endobronchial brushing (4). No procedure was interrupted as a result of an adverse event, and five patients died during the same hospitalization. Four of the deaths occurred 6 to 15 days postprocedure; 1 patient (who had active ischemia at the time of FFB) died 4 h postprocedure. We conclude that FFB is safe in the immediate post-AMI period as long as the patient does not have active ischemia at the time of the procedure.

Necrosis of the bronchus. Role of radiation

The effects of radiation on the lung parenchyma and pleura are well described in the literature. Necrosis of the larynx is a known complication of radiation therapy. Necrosis of a part of the tracheobronchial tree following radiation therapy for bronchogenic carcinoma is likely to occur; however, there is little mention in the English-language literature about such an effect. This report describes four cases with total necrosis of a specific bronchus following radiation therapy for squamous cell carcinoma of the lung. All patients received 5,000 to 6,400 rad (50 to 64 Gy) of external-beam radiation. Two patients presented with massive hemoptysis and two with pneumonia. In all four cases, the patients were found to have, by bronchoscopy, necrosis of the bronchus with the involved lobe of the lung replaced by a large cavity lined by tumor tissue. Diagnosis was made 5 to 7 months after radiation therapy was completed. Three of the patients died of exsanguination within weeks following diagnosis of the complication. We suspect that such necrosis occurs as a consequence of radiation therapy in combination with infection in the set up of squamous cell carcinoma, and is a marker of poor prognosis.

Rare pulmonary manifestation of Ehlers-Danlos syndrome

Ehlers-Danlos syndrome (EDS) is an inherited disorder of connective tissue with multiple thoracic manifestations. We present an unusual thoracic manifestation of EDS consisting of parenchymal cysts and fibrous and fibroosseous nodules. These manifestations may be related to an abnormal attempt at repair of parenchymal or vascular tears.