Repetitive sulfur dioxide exposure in mice models post-deployment respiratory syndrome.

Soldiers deployed to Iraq and Afghanistan have a higher prevalence of respiratory symptoms than nondeployed military personnel and some have been shown to have a constellation of findings on lung biopsy termed post-deployment respiratory syndrome (PDRS). Since many of the subjects in this cohort reported exposure to sulfur dioxide (SO2), we developed a model of repetitive exposure to SO2 in mice that phenocopies many aspects of PDRS, including adaptive immune activation, airway wall remodeling, and pulmonary vascular (PV) disease. Although abnormalities in small airways were not sufficient to alter lung mechanics, PV remodeling resulted in the development of pulmonary hypertension and reduced exercise tolerance in SO2-exposed mice. SO2 exposure led to increased formation of isolevuglandins (isoLGs) adducts and superoxide dismutase 2 (SOD2) acetylation in endothelial cells, which were attenuated by treatment with the isoLG scavenger 2-hydroxybenzylamine acetate (2-HOBA). In addition, 2-HOBA treatment or Siruin-3 overexpression in a transgenic mouse model prevented vascular remodeling following SO2 exposure. In summary, our results indicate that repetitive SO2 exposure recapitulates many aspects of PDRS and that oxidative stress appears to mediate PV remodeling in this model. Together, these findings provide new insights regarding the critical mechanisms underlying PDRS.NEW & NOTEWORTHY We developed a mice model of "post-deployment respiratory syndrome" (PDRS), a condition in Veterans with unexplained exertional dyspnea. Our model successfully recapitulates many of the pathological and physiological features of the syndrome, revealing involvement of the ROS-isoLGs-Sirt3-SOD2 pathway in pulmonary vasculature pathology. Our study provides additional knowledge about effects and long-term consequences of sulfur dioxide exposure on the respiratory system, serving as a valuable tool for future PDRS research.

IgG4-Related disease with diffuse myopericardial involvement- value of CMR: a case report and literature review of cardiac involvement.

BACKGROUND: IgG4-related disease is a fibro-inflammatory disorder with an unknown etiology, which can affect multiple organ systems, including the cardiovascular system. While most reported cases of cardiovascular involvement are primarily associated with the aorta, there have been sporadic reports of isolated cardiac involvement. CASE PRESENTATION: This paper presents a documented case of IgG4-related systemic disease with symptoms indicative of restrictive cardiomyopathy. Subsequent Cardiac Magnetic Resonance imaging revealed diffuse myopericardial involvement, characterized by pericardial thickening and enhancement, accompanied by subepicardial and myocardial infiltration. Considering the rarity of cardiac involvement in our case, we conducted a thorough review of the existing literature pertaining to various patterns of cardiac involvement in IgG4-related disease, as well as the diagnostic modalities that can be employed for accurate identification and assessment. CONCLUSIONS: This case report sheds light on the importance of recognizing and evaluating cardiac manifestations in IgG4-related systemic disease to facilitate timely diagnosis and appropriate management.

Semiquantitative 18F-FDG PET/CT in monitoring glucocorticoid response of immunoglobulin G4-related effusive constrictive pericarditis: a case report.

BACKGROUND: Immunoglobulin G4 (IgG4)-related effusive constrictive pericarditis (ECP) is a rare manifestation of IgG4-related disease (IgG4-RD). It can lead to persistent pericardial fibrosis, resulting in cardiac tamponade, diastolic dysfunction, and heart failure. Glucocorticoids are the primary treatment for effectively reducing inflammation and preventing fibrosis. However, guidelines for monitoring treatment response are lacking and tapering glucocorticoid therapy for specific target organs remains a challenge. Recent studies on IgG4-RD have demonstrated that semiquantitative measurements of fluorine-18 fluorodeoxyglucose (18F-FDG) uptake in the main involved organs in positron emission tomography/computed tomography (PET/CT) scanning are correlated to disease activity. We present a case of IgG4-related ECP to demonstrate the usefulness of 18F-FDG PET/CT for diagnosing and treatment follow-up of IgG4-related ECP. CASE PRESENTATION: Herein, a 66-year-old woman diagnosed with IgG4-related ECP presented with breathlessness, leg swelling, rales, and fever. Laboratory tests revealed markedly elevated levels of C-reactive protein, and transthoracic echocardiography revealed constrictive physiology with effusion. High IgG4 levels suggested an immune-related pathogenesis, while viral and malignant causes were excluded. Subsequent pericardial biopsy revealed lymphocyte and plasma cell infiltration in the pericardium, confirming the diagnosis of IgG4-related ECP. 18F-FDG PET/CT revealed increased uptake of 18F-FDG in the pericardium, indicating isolated cardiac involvement of IgG4-RD. Treatment with prednisolone and colchicine led to a rapid improvement in the patient's condition within a few weeks. Follow-up imaging with 18F-FDG PET/CT after 3 months revealed reduced inflammation and improved constrictive physiology on echocardiography, leading to successful tapering of the prednisolone dose and discontinuation of colchicine. CONCLUSION: The rarity of IgG4-related ECP and possibility of multiorgan involvement in IgG4-RD necessitates a comprehensive diagnostic approach and personalized management. This case report highlights the usefulness of 18F-FDG PET/CT in the diagnosis and treatment follow-up of isolated pericardial involvement in IgG4-RD.

Constrictive pericarditis in a patient with fiberglass lung disease: a case report.

BACKGROUND: Fiberglass has a larger aerodynamic diameter and is less likely to be inhaled into the lungs. Further, it will be cleared even if it is mechanically broken into smaller pieces and inhaled into the lungs. Fiberglass lung disease has been well documented if long term exposure but was thought reversible and would not cause severe diseases. The diagnosis of fiberglass lung disease depends on exposure history and histopathological findings. However, the exact occupational exposure history is often difficult to identify because mixed substance exposure often occurs and fiberglass disease is not as well-known as asbestosis. CASE PRESENTATION: A 66-year-old man had unexplained transudative pericardial effusion requiring pleural pericardial window operation twice at another medical center where asbestosis was told because of his self-reported long-term asbestosis exposure and the histopathological finding of a ferruginous body in his lung. Constrictive pericarditis developed two years later and resulted in congestive heart failure. Radical pericardiectomy combined with lung biopsy was performed following chest computed tomography imaging and the transudative nature of pericardial effusion not compatible with asbestosis. However, the histopathologic findings of his lung and pericardium at our hospital only showed chronic fibrosis without any asbestosis body. The patient's lung was found to be extremely fragile during a lung biopsy; histopathologic specimens were reviewed, and various fragments of fiberglass were found in the lung and pericardium. The patient's occupational exposure was carefully reevaluated, and he restated that he was only exposed to asbestosis for 1-2 years but was heavily exposed to fiberglass for more than 40 years. This misleading exposure history was mainly because he was only familiar with the dangers of asbestos. Since most fiberglass lung diseases are reversible and the symptoms of heart failure resolve soon after surgery, only observation was needed. Ten months after radical pericardiectomy, his symptoms, pleural effusion, and impaired pulmonary function eventually resolved. CONCLUSION: Fiberglass could cause inflammation of the pericardium, resulting in pericardial effusion and constrictive pericarditis, which could be severe and require radical pericardiectomy. Exact exposure history and histopathological examinations are the key to diagnosis.

Ultrasound analysis of cervical thoracic duct for patients with constrictive pericarditis and chylothorax.

PURPOSE: To analyze ultrasound features of cervical thoracic duct for patients with constrictive pericarditis and chylothorax. METHODS: Patients were retrospectively assessed. The patients were divided into a non-pleural effusion (PE) group (n = 54), a chylothorax group (n = 23), and non-chylothorax group (n = 28). Conventional ultrasound was used to obtain the maximum inner diameter and collapse of the inferior vena cava, the inner diameter of left cervical thoracic duct, and the frequency of opening of the valve at the end of the left thoracic duct. Contrast ultrasonography was used to score the reverse flow of the thoracic tube. RESULTS: The percentage of PE was 48.5%, and the percentage of chylothorax was 21.9%. The three groups had significant differences in five parameters. The inner diameter of left cervical thoracic duct was correlated with the degree of central venous pressure. Contrast ultrasonography was effective in quantitative assessment of the degree of intravenous-thoracic cord reverse flow which correlated with all parameters of central venous pressure. CONCLUSION: Thoracic duct dilation and regurgitation secondary to central venous pressure can lead to chyloreflux disorder and may be the mechanism of chylothorax occurrence in constrictive pericarditis.

Surgical treatment of constrictive pericarditis at a single center: 10 years of experience.

BACKGROUND: Constrictive pericarditis (CP) is a pericardial disease characterized by the pericardium becoming calcified or fibrotic as a result of chronic inflammation, which impairs diastolic filling by compressing the cardiac chambers. Pericardiectomy is a promising surgical option for treating CP. In this study, we reviewed over 10 years of preoperative, perioperative, and short-term postoperative follow-ups of patients who underwent pericardiectomy for constrictive pericarditis at our clinic. METHODS: Between January 2012 and May 2022, 44 patients were diagnosed with constrictive pericarditis. Twenty-six patients underwent pericardiectomy for CP. Median sternotomy is the surgical approach of choice because it provides easy access for complete pericardiectomy. RESULTS: The patient median age was 56 (min: 32, max: 71), and 22 out of 26 patients (84.6%) were male. Twenty-one patients (80.8%) complained of dyspnea, which was the most common reason for admission. Twenty-four patients (92.3%) were scheduled for elective surgery. Cardiopulmonary bypass (CPB) was used during the procedure in six patients (23%). The duration of intensive care stay was two days (min: 1, max: 11), and the total hospitalization was six days (min: 4, max: 21). No in-hospital mortality was observed. CONCLUSION: The median sternotomy approach provides a critical advantage in terms of performing a complete pericardiectomy. Although CP is a chronic condition, early diagnosis and planning of pericardiectomy before irreversible deterioration of cardiac function leads to a notable reduction in mortality and morbidity.

Cutaneous Exposure to Arsenicals Is Associated with Development of Constrictive Bronchiolitis in Mice.

Organoarsenicals, such as lewisite and related chloroarsine, diphenylchloroarsine (DPCA), are chemical warfare agents developed during World War I. Stockpiles in Eastern Europe remain a threat to humans. The well-documented effects of cutaneous exposure to these organoarsenicals include skin blisters, painful burns, and life-threatening conditions such as acute respiratory distress syndrome. In survivors, long-term effects such as the development of respiratory ailments are reported for the organoarsenical sulfur mustard; however, no long-term pulmonary effects are documented for lewisite and DPCA. No animal models exist to explore the relationship between skin exposure to vesicants and constrictive bronchiolitis. We developed and characterized a mouse model to study the long-term effects of cutaneous exposure on the lungs after exposure to a sublethal dose of organoarsenicals. We exposed mice to lewisite, DPCA, or a less toxic surrogate organoarsenic chemical, phenyl arsine oxide, on the skin. The surviving mice were followed for 20 weeks after skin exposure to arsenicals. Lung microcomputed tomography, lung function, and histology demonstrated increased airway resistance, increased thickness of the smooth muscle layer, increased collagen deposition in the subepithelium, and peribronchial lymphocyte infiltration in mice exposed to arsenical on skin.

Chronic constrictive pericarditis: a rare cardiac involvement in primary Sjögren's syndrome.

BACKGROUND: Constrictive pericarditis represents a chronic condition and systemic inflammatory diseases are a known, yet uncommon, cause. Pericardial involvement is seldom reported in primary Sjögren's syndrome, usually occurring in association with pericardial effusion or pericarditis. We report a case of constrictive pericarditis with an insidious course and unusual evolution associated with primary Sjögren's syndrome. Due to the challenging nature of the diagnosis, clinical suspicion and multimodality imaging are essential for early identification and prompt initiation of treatment. Long-term outcomes remain uncertain. To the best of our knowledge, no other cases linking this autoimmune disease to constrictive pericarditis have been reported. CASE PRESENTATION: We present the case of a 48-year-old male patient with moderate alcohol habits and a history of two prior hospitalizations. On the first, the patient was diagnosed with primary Sjögren's syndrome after presenting with pleural effusion and ascites, and empirical corticosteroid regiment was initiated. On the second, two-years later, he was readmitted with complaints of dyspnea and abdominal distension. Thoracic computed tomography revealed a localized pericardial thickening and a thin pericardial effusion, both of which were attributed to his rheumatic disease. A liver biopsy showed hepatic peliosis, which was considered to be a consequence of glucocorticoid therapy. Diuretic therapy was adjusted to symptom-relief, and a tapering corticosteroid regimen was adopted. Four years after the initial diagnosis, the patient was admitted again with recurrent dyspnea, orthopnea and ascites. At this time, constrictive pericarditis was diagnosed and a partial pericardiectomy was performed. Although not completely asymptomatic, the patient reported clinical improvement since the surgery, but still with a need for baseline diuretic therapy. CONCLUSION: Albeit uncommon, connective tissue disorders, such as primary Sjögren's syndrome, should be considered as a potential cause of constrictive pericarditis, especially in young patients with no other classical risk factors for constriction. In this case, after excluding possible infectious, neoplastic and autoimmune conditions, a primary Sjögren´s syndrome in association with constrictive pericarditis was assumed. This case presents an interesting and challenging clinical scenario, highlighting the importance of clinical awareness and the use of multimodal cardiac imaging for early recognition and treatment.

Anesthesia management for pericardiectomy- a case series study.

BACKGROUND: Constrictive pericarditis (CP) is an uncommon disease that limits both cardiac relaxation and contraction. Patients often present with right-sided heart failure as the pericardium thickens and impedes cardiac filling. Pericardiectomy is the treatment of choice for improving hemodynamics in CP patients; however, the procedure carries a high morbidity and mortality, and the anesthetic management can be challenging. Acute heart failure, bleeding and arrhythmias are all concerns postoperatively. METHODS: After IRB approval, we performed the retrospective analysis of 66 consecutive patients with CP who underwent pericardiectomy from July 2018 to May 2022. RESULTS: Most patients had significant preoperative comorbidities, including congestive hepatopathy (75.76%), New York Heart Association Type III/IV heart failure (59.09%) and atrial fibrillation (51.52%). Despite this, 75.76% of patients were extubated within the first 24 h and all but 2 of the patients survived to discharge (96.97%). CONCLUSIONS: Anesthetic management, including a thorough understanding of the pathophysiology of CP, the use of advanced monitoring and transesophageal echocardiography (TEE) guidance, all played an important role in patient outcomes.

Pericardial mesothelioma presenting as constrictive pericarditis.

A 46-year-old woman underwent pericardiocentesis and pericardial window for recurrent pericardial effusion. She presented 17 months later with signs and symptoms consistent with constrictive pericarditis. Cardiac magnetic resonance imaging revealed an infiltrative mass surrounding the pericardium. A transcutaneous core needle biopsy of the pericardium confirmed the diagnosis of pericardial mesothelioma.

Surgical Approaches for Pericardial Diseases: What Is New?

PURPOSE OF REVIEW: The purpose of this review is to discuss the evolving techniques and approaches for pericardiectomy, with a focus on the use of cardiopulmonary bypass (CPB) and the extent of radical pericardial resection. The review aims to highlight the benefits and considerations associated with these modifications in radical pericardiectomy. RECENT FINDINGS: Recent studies have demonstrated that the use of CPB during pericardiectomy does not increase procedural risk or negatively impact survival. In fact, it has been shown to contribute to a more radical resection and improve postoperative outcomes, which is associated with less recurrence and better survival. The review emphasizes the importance of radical pericardiectomy and the use of CPB in achieving successful outcomes. Radical resection of the pericardium, facilitated by CPB, helps minimize the risk of recurrent constrictions and the need for reinterventions. The findings highlight the correlation between postoperative outcomes and survival, further supporting the use of CPB.

Sclerotherapy of oesophageal varices may induce chronic constrictive pericarditis in children.

Constrictive pericarditis is rare in children and can be difficult to diagnose. It has been described in adults after sclerotherapy of oesophageal varices but not in children. We report two cases of chronic constrictive pericarditis after sclerotherapy of oesophageal varices in children with portal cavernoma. Constrictive pericarditis should be considered as a cause of refractory ascites.

Diagnostic imaging and histopathologic features of rounded atelectasis in four cats and one dog: A descriptive case series study.

In humans, rounded atelectasis is defined as focal lung collapse that radiologically appears as a round mass-like lesion in the periphery of the lung. In general, human patients with rounded atelectasis have a history of pleural effusion and abnormal pleura and characteristic CT findings help to distinguish rounded atelectasis from pulmonary neoplasia without the need for invasive surgical biopsy. This retrospective multi-center case series describes rounded atelectasis in four cats and one dog. Chylothorax was seen in four patients and an eosinophilic and lymphoplasmacytic effusion was seen in one patient. All patients had solitary or multifocal subpleural pulmonary masses (26 masses total in 5 patients) with diffuse, multifocal, or focal visceral and parietal pleural thickening. All the masses but one were broad-based towards the visceral pleura. Masses were most common in the ventral or lateral aspect of the lungs. Indistinctness at the hilar aspect of the lesion was seen in all masses; a "comet tail" sign was seen in 14 of 26 masses. On postcontrast images, the lesions were homogeneously enhanced in 24 of 26 masses and heterogeneous in two of 26 masses. Other findings include ground glass opacities (n = 5), parenchymal bands (n = 4), mild to moderate lymphadenopathy (n = 4), and compensatory hyperinflation of the lung lobes not affected by atelectasis (n = 2). Histopathology of four cases revealed atelectasis with fixed pleural folds, chronic pleuritis, and mild to moderate pleural fibrosis. Awareness of rounded atelectasis in veterinary species will enable inclusion of a benign etiology into the differential diagnosis for subpleural masses in cases with pleural abnormalities.

CT features of rounded atelectasis in chronic inflammatory pleural effusions in cats and dogs.

Rounded atelectasis is well described in human medicine as focal lung deformation and collapse secondary to inflammatory pleural effusions and pleuritis. Specific CT features (round to ovoid soft tissue pulmonary attenuations, creation of an acute angle with the adjoining visceral pleura, and the presence of perinodular comet tail signs) support the diagnosis of rounded atelectasis in humans so that further diagnostic workup is not necessary in defining the nodules. In this retrospective case series, we described the CT characteristics of rounded atelectasis in eight cats and three dogs diagnosed with restrictive pleuritis secondary to either a chylothorax or pyothorax. Thirty-six soft tissue attenuating pulmonary nodular lesions were identified on CT. Comet tail signs, consisting of bundles of bronchi and vessels coalescing into the pulmonary nodules, were associated with 92% of the nodules (33/36), and 92% of the nodules abutted and created an acute angle with the pleura (33/36). Other prevalent features included location in gravity-dependent regions of the lung lobes (33/36, 92%), blurred hilar margins with sharper pleural margins of the nodules (33/36, 92%), presence of air bronchograms (30/36, 83%), homogeneous contrast-enhancement (23/36, 64%), and volume loss of the affected lung lobe (22/36, 61%). Pulmonary malignant neoplasms were not found cytologically (6/11 patients) or histologically (5/11 patients). To avoid a misdiagnosis of neoplasia, veterinary radiologists should be aware of the CT features of rounded atelectasis and consider it as a differential for pulmonary nodular lesions in patients with concurrent inflammatory pleural effusion and pleuritis.

Contralateral Projection of Anterior Cingulate Cortex Contributes to Mirror-Image Pain.

Long-term limb nerve injury often leads to mirror-image pain (MIP), an abnormal pain sensation in the limb contralateral to the injury. Although it is clear that MIP is mediated in part by central nociception processing, the underlying mechanisms remain poorly understood. The anterior cingulate cortex (ACC) is a key brain region that receives relayed peripheral nociceptive information from the contralateral limb. In this study, we induced MIP in male mice, in which a unilateral chronic constrictive injury of the sciatic nerve (CCI) induced a decreased nociceptive threshold in both hind limbs and an increased number of c-Fos-expressing neurons in the ACC both contralateral and ipsilateral to the injured limb. Using viral-mediated projection mapping, we observed that a portion of ACC neurons formed monosynaptic connections with contralateral ACC neurons. Furthermore, the number of cross-callosal projection ACC neurons that exhibited c-Fos signal was increased in MIP-expressing mice, suggesting enhanced transmission between ACC neurons of the two hemispheres. Moreover, selective inhibition of the cross-callosal projection ACC neurons contralateral to the injured limb normalized the nociceptive sensation of the uninjured limb without affecting the increased nociceptive sensation of the injured limb in CCI mice. In contrast, inhibition of the non-cross-callosal projection ACC neurons contralateral to the injury normalized the nociceptive sensation of the injured limb without affecting the MIP exhibited in the uninjured limb. These results reveal a circuit mechanism, namely, the cross-callosal projection of ACC between two hemispheres, that contributes to MIP and possibly other forms of contralateral migration of pain sensation.SIGNIFICANCE STATEMENT Mirror-image pain (MIP) refers to the increased pain sensitivity of the contralateral body part in patients with chronic pain. This pathology requires central processing, yet the mechanisms are less known. Here, we demonstrate that the cross-callosal projection neurons in the anterior cingulate cortex (ACC) contralateral to the injury contribute to MIP exhibited in the uninjured limb, but do not affect nociceptive sensation of the injured limb. In contrast, the non-cross-callosal projection neurons in the ACC contralateral to the injury contribute to nociceptive sensation of the injured limb, but do not affect MIP exhibited in the uninjured limb. Our study depicts a novel cross-callosal projection of ACC that contributes to MIP, providing a central mechanism for MIP in chronic pain state.

Multi-Modality Cardiac Imaging for Pericardial Diseases: A Contemporary Review.

Advances in multi-modality cardiac imaging have aided the evaluation, surveillance and treatment guidance of pericardial diseases, which have traditionally been a challenging group of conditions to manage. Although echocardiography remains the first-line imaging modality to assess the pericardium, both computed tomography (CT) and magnetic resonance imaging (MRI) have valuable complimentary roles. It is critical for clinicians to have a clear understanding of the utilities, advantages and disadvantages of these cardiac imaging modalities in pericardial pathologies. This contemporary review provides an update regarding the applications of multi-modality cardiac imaging in the evaluation of pericardial syndromes including acute/recurrent pericarditis, effusion/tamponade, constriction, masses and congenital anomalies.

Clinical genetic testing in four highly suspected pediatric restrictive cardiomyopathy cases.

BACKGROUND: Restrictive cardiomyopathy (RCM) presents a high risk for sudden cardiac death in pediatric patients. Constrictive pericarditis (CP) exhibits a similar clinical presentation to RCM and requires differential diagnosis. While mutations of genes that encode sarcomeric and cytoskeletal proteins may lead to RCM, infection, rather than gene mutation, is the main cause of CP. Genetic testing may be helpful in the clinical diagnosis of RCM. METHODS: In this case series study, we screened for TNNI3, TNNT2, and DES gene mutations that are known to be etiologically linked to RCM in four pediatric patients with suspected RCM. RESULTS: We identified one novel heterozygous mutation, c.517C>T (substitution, position 517 C → T) (amino acid conversion, p.Leu173Phe), and two already known heterozygous mutations, c.508C>T (substitution, position 508, C → T) (amino acid conversion, p.Arg170Trp) and c.575G>A (substitution, position 575, G → A) (amino acid conversion, p.Arg192His), in the TNNI3 gene in three of the four patients. CONCLUSION: Our findings support the notion that genetic testing may be helpful in the clinical diagnosis of RCM.

Immunoglobulin G4-related constrictive pericarditis and the importance of a thorough workup: a case report.

BACKGROUND: Constrictive pericarditis remains a problematic diagnosis and a thorough investigation is critical. Among possible aetiologies, immunoglobulin-G4 (IgG4)-related pericardial disease is an unusual cause of pericardial constriction. We report a challenging diagnostic case of pericardial constriction due to IgG4-related disease. CASE PRESENTATION: A 68-year old male with a history of inferior myocardial infarction with right ventricle (RV) involvement was thrice-hospitalized due to marked ascites and peripheral oedema. Systemic congestion was initially attributed to RV dysfunction due to previous infarction. Yet, at the final admission, a re-assessment echocardiogram followed by cardiac computed tomography, magnetic resonance and right heart catheterization raised a possible diagnosis of constrictive pericarditis with a finding of abnormal pulmonary venous return. Patient therefore underwent pericardiectomy and surgical correction of pulmonary venous return. Pericardium histology revealed an IgG4-related pericardial constriction. Patient was later discharged on corticosteroids with marked symptomatic improvement. CONCLUSION: IgG4-related disease remains a rare cause of pericardium constriction while also presenting a challenging diagnosis in everyday clinical practice. This case exemplifies the difficulties faced by clinicians when reviewing a possible case of constrictive pericarditis, while highlighting the importance of a multimodality assessment.

Constrictive bronchiolitis obliterans with a presumptive etiology of preceding feline herpesvirus infection in a cat.

BACKGROUND: Bronchiolar disorders are rarely recognized in cats. Constrictive bronchiolitis obliterans is characterized by concentric peribronchiolar fibrosis and inflammation of the bronchioles, but the underlying causes remain poorly understood in current small animal medicine. CASE PRESENTATION: A 9-year-old cat presented with paroxysmal tachypnea, infrequent cough and persistent labor breathing. Thoracic radiography showed lung hyperinflation and bronchointerstitial pattern, and pulmonary function assessment revealed flow limitation in the late-expiratory phase and poor response to short-acting bronchodilator. Dorsally distributed subpleural ground glass opacities with distinct margin and tree-in-bud opacities were observed on lung high-resolution computed tomography. The cat underwent bronchoalveolar lavage (BAL) and showed severe neutrophilic inflammation. Feline herpesvirus was the only pathogen detected in the BAL fluid. Multiple therapeutic attempts were unsuccessful and the cat died 8 weeks after the initial presentation. Necropsy revealed the infiltration of inflammatory cells, obstruction of the bronchiolar lumen, and submucosal concentric fibrosis suggesting constrictive bronchiolitis obliterans. Combining the pre- and post-mortem findings, as well as the time from symptom onset or BAL to necropsy, constrictive bronchiolitis obliterans was possibly triggered by a preceding feline herpesvirus infection in this case. CONCLUSIONS: The history of nonvaccinated status, lower airway neutrophilic inflammation, and presence of feline herpesvirus in the BAL fluid without coexistence of other pathogens led to the presumption that constrictive bronchiolitis obliterans was induced by a preceding feline herpesvirus infection in this cat. The pathological changes of bronchiolitis obliterans induced by a preceding feline herpesvirus infection could be different from that of cats with acute herpesvirus pneumonia, such as intranuclear inclusions would disappear over time and were no longer found 7-10 days after inoculation. The presence of patchy distribution of subpleural ground glass opacities on lung high-resolution computed tomography should raise the suspicion of peribronchiolar fibrosis. Clinical awareness of bronchiolar disorders as a differential diagnosis is important in cats with lung hyperinflation and labored breathing who show poor reversibility to bronchodilator.

Rituximab therapy in pericarditis associated with rheumatoid arthritis.

In rheumatoid arthritis, pericarditis is commonly asymptomatic, but rarely, it progresses to a morbid complication, like cardiac tamponade or restrictive pericarditis. Current studies have indicated that conventional drugs have limited ability to reverse these lethal conditions. To date, invasive surgical measures remain the only definitive therapy for patients who are unresponsive to drugs. Recently, anti-tumor necrosis factor-α and anti-interleukin-1 antibody-based drugs have shown limited success. Consequently, given the importance of pericarditis, we need new treatment methods. Here, we describe a patient with rheumatoid arthritis and effusive pericarditis, which progressed to life-threatening cardiac tamponade. The patient responded very well to rituximab. Thus, rituximab represents a potential new therapy for this rarely treated complication of rheumatoid arthritis.