Identification and characterization of calcium binding protein, spermatid-associated 1 (CABS1)# in selected human tissues and fluids.

Calcium binding protein, spermatid associated 1 (CABS1) is a protein most widely studied in spermatogenesis. However, mRNA for CABS1 has been found in numerous tissues, albeit with little information about the protein. Previously, we identified CABS1 mRNA and protein in human salivary glands and provided evidence that in humans CABS1 contains a heptapeptide near its carboxyl terminus that has anti-inflammatory activities. Moreover, levels of an immunoreactive form of CABS1 were elevated in psychological stress. To more fully characterize human CABS1 we developed additional polyclonal and monoclonal antibodies to different sections of the protein and used these antibodies to characterize CABS1 in an overexpression cell lysate, human salivary glands, saliva, serum and testes using western blot, immunohistochemistry and bioinformatics approaches exploiting the Gene Expression Omnibus (GEO) database. CABS1 appears to have multiple molecular weight forms, consistent with its recognition as a structurally disordered protein, a protein with structural plasticity. Interestingly, in human testes, its cellular distribution differs from that in rodents and pigs, and includes Leydig cells, primary spermatogonia, Sertoli cells and developing spermatocytes and spermatids, Geodata suggests that CABS1 is much more widely distributed than previously recognized, including in the urogenital, gastrointestinal and respiratory tracts, as well as in the nervous system, immune system and other tissues. Much remains to be learned about this intriguing protein.

Histological Techniques for Sectioning Bones of the Vertebrate Craniofacial Skeleton.

Histochemical analysis is an indispensable technique in the field of biology used routinely to characterize pathologies of interest throughout the system. This chapter provides the craniofacial biologist with an introduction to tissue harvesting, embedding, and sectioning as well as a toolkit of useful stains for stromal/mesenchymal tissues including bone and cartilage. Techniques are tailored to decalcified, paraffin-embedded mouse tissue; however, these methods are applicable under a broad range of conditions.

ANOTHER syndrome-Familial presentations of progressive lung disease leading to double lung transplantation: A case report and literature review.

Ectodermal dysplasias (EDs) are a heterogeneous rare group of disorders with an incidence at 1/100,000 live births. Currently, there are limited case reports of patients requiring lung transplantation. Here, we report two brothers who present with a constellation of features including alopecia, nail dystrophy, ophthalmic complications, thyroid disease, hypohidrosis, ephelides, enteropathy and recurrent respiratory tract infections, known as ANOTHER syndrome, a rare autosomal recessive variant of ED. Both presented in early childhood with progressive respiratory decline and eventual failure. Chronic respiratory decline was refractory to standard therapy. Both patients required lung transplantation for sequelae of end-stage lung disease. Pathology demonstrated multifocal bronchiectasis with areas of fibrosis and small airway obstruction. ANOTHER syndrome is rare with a paucity of data in the literature. Given the limited therapeutic options available with natural progression towards respiratory failure, lung transplantation may be considered.

Progressive Dyspnea With Recurrent Pneumothoraces.

CASE PRESENTATION: A 34-year-old previously healthy man of Korean descent (height, 174 cm; weight, 47.4 kg) demonstrated dyspnea with cough and chest tightness. The patient had no relevant occupational exposures and no history of illicit drug or tobacco use. His medical history was notable for chronic sinus tachycardia of undetermined cause, hypertension, gout, glaucoma of the right eye, and a remote history of an intracranial malignancy 24 years prior treated with unspecified chemotherapy, craniotomy, and ventriculoperitoneal shunt placement. His active medications included diltiazem, candesartan, and colchicine as needed.

Factors affecting thyroid nodule fine needle aspiration non-diagnostic rates: a retrospective association study of 1975 thyroid biopsies.

BACKGROUND: Thyroid nodules are common in clinical practice, and it is important to distinguish benign nodules, the vast majority, from malignant ones. Non-diagnostic (ND) samples have the potential to delay or mis-diagnose or lead to unnecessary surgeries, and it is important to examine what factors influence the ND rate. Prior literature has suggested that the impact of bedside cytology on ND rate is dependent on the initial adequacy rate, whereby higher ND rates benefit most from bedside cytology. We aim to compare the impact of bedside adequacy review between specialist groups who perform high volume thyroid biopsies with low initial ND rates. METHODS: We reviewed the cytopathology results of 1975 thyroid nodule FNAs performed between January 1, 2017 to December 31, 2017 in a multi-centre Canadian city, and the corresponding histopathology reports of 340 resected nodules. Descriptive variables were used to describe the data along with chi-squared testing and univariate logistic regression. RESULTS: The FNA biopsies were performed by three different speciality groups, which differed by procedural volume: radiology performed the most at 1171, pathology performed 655 and surgery performed 103. We could not define the operator for 45 of the nodules. The ND rate was lowest in the speciality groups with highest procedural volume, 3.4 % in pathology and 8.3 % in radiology, compared to 37.9 % in surgery (p < 0.001). Completion of bedside cytology rapid onsite evaluation (ROSE) significantly reduced the ND rate from 16.7 to 4.2 % for all samples (p < 0.001). When ROSE was compared with non-ROSE within a high procedural group (radiology), it further reduced the ND rate from 12.5 to 5.1 % (p < 0.001). Of the 340 resected nodules, 10.7 % (18) were in the ND category, of which 28 % (5/18) of these were found to be malignant (4 papillary carcinoma and 1 lymphoma). CONCLUSIONS: The results from this study demonstrate that thyroid FNAs performed with bedside ROSE can significantly reduce the ND rate compared with non-ROSE, even in experienced groups with low initial ND rates. It is therefore imperative that care providers managing patients with thyroid nodules ensure that thyroid FNAs are referred to specialized individuals/groups who do high volume, and ideally with the use of bedside ROSE, whether provided by a cytotechnologist or a pathologist.

EGFR as a biomarker of smoking status and survival in oropharyngeal squamous cell carcinoma.

BACKGROUND: This study aims to investigate EGFR as a prognostic biomarker in oropharyngeal squamous cell carcinoma (OPSCC). METHODS: OPSCC patients from retrospective (1998-2009) and prospective cohorts (2014-2017) were included. Retrospectively collected tumors were used to construct tissue microarrays (TMAs), which were stained with EGFR, p16, DAPI and Pan-cytokeratin, and digitally quantified. EGFR, CDKN2A and HPV E6/7 levels from prospectively collected OPSCC was measured by droplet digital PCR (ddPCR). Biomarkers were compared to patient covariates, factors and survival outcomes. RESULTS: A total of 249 patients were included retrospectively and 64 patients were enrolled prospectively. p16 status (p < 0.001), smoking above 10 pack years (p = 0.04), smoking above 20 pack years (p < 0.001), total EGFR tumor levels (p = 0.016), and high EGFR within high or low Ki67 tumor nuclear staining (p = 0.03) were found to be significant predictors of 5-year disease specific survival (DSS). A Cox proportional hazard model of DSS showed smoking status and eGFR expression to be dependent of each other on predicting 5-year DSS. ddPCR analysis showed a significant association between smoking status and EGFR levels. CONCLUSIONS: Total EGFR tumor levels are predictive of 5-year DSS. EGFR levels correlate with. smoking and could be an objective marker for this disease etiology.

The association of Bcl-xL and p53 expression with survival outcomes in oropharyngeal cancer.

BACKGROUND: The role of molecular biomarkers in oropharyngeal squamous cell carcinoma (OPSCC) has recently been increasingly recognized. There is conflicting evidence in the literature with regards to the prognostic value of p53 and Bcl-xL. OBJECTIVE: The purpose of this study was to investigate the association between p53 and Bcl-xL expression profiles and survival outcomes in OPSCC. METHODS: Patients diagnosed with OPSCC and treated with curative intent between 1998 and 2009 were included in the study. Patient demographics, disease, treatment, and oncologic outcomes were collected prospectively. A tissue microarray (TMA) from patients' biopsies or surgical specimens was retrospectively constructed. The expression levels of p53, Bcl-xL, and p16 were digitally quantified and correlated to patient survival outcomes. RESULTS: One hundred and sixty-six patients were included (mean age 56.7 years; standard deviation (SD) ± 10.0; 78% male). High expression of Bcl-xL (p= 0.04) was significantly associated with nodal disease at presentation, and decreased overall survival (OS) (p= 0.04). Combined expression of low Bcl-xL and low p53 conferred a survival advantage in non-smokers (p= 0.04). Multivariate analysis supported smoking and p16 status as independent prognosticators for OS. CONCLUSIONS: This study suggests that biomarker profiling using Bcl-xL and p53 levels may be of prognostic value in select patients with OPSCC.

Vesicle-associated membrane protein 7-mediated eosinophil degranulation promotes allergic airway inflammation in mice.

Eosinophil degranulation is a determining factor in allergy-mediated airway pathology. Receptor-mediated degranulation in eosinophils requires vesicle-associated membrane protein 7 (VAMP-7), a principal component of the SNARE fusion machinery. The specific contribution of eosinophil degranulation to allergen-induced airway responses remains poorly understood. We generated mice with VAMP-7 gene deficiency exclusively in eosinophils (eoCRE/V7) from a cross using eosinophil-specific Cre recombinase-expressing mice crossed with VAMP-7 f/f mice. Eosinophils from eoCRE/V7 mice showed deficient degranulation responses in vitro, and responses continued to be decreased following ex vivo intratracheal adoptive transfer of eoCRE/V7 eosinophils into IL-5/hE2/EPX -/- mice. Consistent with diminished degranulation responses, reduced airway hyperresponsiveness was observed in ovalbumin-sensitized and challenged eoCRE/V7 mice following methacholine inhalation. Therefore, VAMP-7 mediates eosinophil degranulation both in vitro and ex vivo, and this event augments airway hyperresponsiveness.

Association of Fludeoxyglucose F 18-Labeled Positron Emission Tomography and Computed Tomography With the Detection of Oropharyngeal Cancer Recurrence.

Importance: No guidelines at present describe when fludeoxyglucose F 18-labeled positron emission tomography and computed tomography (FDG PET-CT) should be used in the initial posttreatment period for evaluation of oropharyngeal squamous cell carcinoma treatment outcome and recurrence. Objective: To compare accuracies of the initial posttreatment PET-CT between primary treatment groups and to define indicators of false-positive findings. Design, Setting, and Participants: This retrospective cohort study identified adults with a new diagnosis of oropharyngeal squamous cell carcinoma who received treatment with curative intent from October 1, 2006, through November 30, 2016, using the Alberta Cancer Registry (n = 380). Patients who underwent PET-CT within 1 year of treatment completion were included (n = 190). Of these, 103 patients (54.2%) had PET-CT findings positive for residual or recurrent disease, and 61 (32.1%) had false-positive findings. Among the 61 patients, 42 (68.9%) had received chemoradiotherapy (CRT) and 19 (31.1%) had primary surgery. Forty-two patients had true-positive findings, indicating a prevalence rate of disease of 22.1%. Data were analyzed from July through October 2017. Exposures: One of 2 primary treatment modalities (surgery with or without adjuvant therapy vs CRT). All patients had posttreatment FDG PET-CT. Main Outcomes and Measures: Primary outcome measures included the diagnostic odds ratio, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of PET-CT for detecting residual and/or recurrent disease. A multivariate analysis determined indicators of false-positive findings. Discriminative ability was assessed using receiver operating characteristic curve analysis of maximum standardized uptake value (SUVmax) metabolic data. Results: Of the 190 participants, 77.9% were men, with a mean (SD) age at diagnosis of 58.5 (8.5) years. The diagnostic odds ratio was 19.3 (95% CI, 5.7-65.1); pooled sensitivity, 93.3% (95% CI, 80.7%-98.3%); and pooled specificity, 57.9% (95% CI, 49.4%-66.0%). The PPV of detecting disease was 54.7% (95% CI, 38.8%-69.8%) for primary surgery and 31.1% (95% CI, 20.2%-44.4%) for CRT. The NPV was 100% (95% CI, 94.7%-100%) for primary surgery and 96.6% (95% CI, 89.5%-99.1%) for CRT. Multivariate analysis identified treatment type, p16 disease, and smoking status as indicative of false-positive findings. In the receiver operating characteristic curve analysis for primary tumors, the optimal cutoff SUVmax for indicating true- vs false-positive results was 5.1 for surgically treated patients (area under the curve, 0.729; 95% CI, 0.570-0.888) and 5.3 for patients treated with CRT (area under the curve, 0.844; 95% CI, 0.700-0.989). Conclusions and Relevance: The results indicate a higher specificity for FDG PET-CT for initial posttreatment surveillance imaging among patients treated with primary surgery compared with nonsurgical management. Both sets of patients with posttreatment FDG PET-CT findings with an SUVmax greater than 5.0 should undergo close evaluation for possible residual or recurrent disease.

Using quantitative tissue phenotype to assess the margins of surgical samples from a pan-Canadian surgery study.

BACKGROUND: The purpose of this study was to use quantitative tissue phenotype (QTP) to assess the surgical margins to examine if a fluorescence visualization-guided surgical approach produces a shift in the surgical field by sparing normal tissue while catching high-risk tissue. METHODS: Using our QTP to calculate the degree of nuclear chromatin abnormalities, Nuclear Phenotypic Score (NPS), we analyzed 1290 biopsy specimens taken from surgical samples of 248 patients enrolled in the Efficacy of Optically-guided Surgery in the Management of Early-staged Oral Cancer (COOLS) trial. Multiple margin specimens were collected from each surgical specimen according to the presence of fluorescence visualization alterations and the distance to the surgical margins. RESULTS: The NPS in fluorescence visualization-altered (fluorescence visualization-positive) samples was significantly higher than that in fluorescence visualization-retained (fluorescence visualization-negative) samples. There was a constant trend of decreasing NPS of margin samples from non-adjacent-fluorescence visualization margins to adjacent-fluorescence visualization margins. CONCLUSION: Our results suggested that using fluorescence visualization to guide surgery has the potential to spare more normal tissue at surgical margins.

Detection of human papillomavirus type 16 in oropharyngeal squamous cell carcinoma using droplet digital polymerase chain reaction.

BACKGROUND: The incidence of oropharyngeal squamous cell carcinoma caused by oncogenic HPV (HPV-OPSCC) is rising worldwide. HPV-OPSCC is commonly diagnosed by RT-qPCR of HPV-16 E6 and E7 oncoproteins or by cyclin-dependent kinase inhibitor 2A, multiple tumor suppressor 1 (p16) immunohistochemistry (IHC). Droplet digital PCR (ddPCR) has been recently reported as ultra-sensitive and highly precise method of nucleic acid quantification for biomarker analysis. We aimed to validate this method for the detection of HPV-16 E6 and E7 in HPV-OPSCC. METHODS: Participants were recruited from January 2015-November 2015 at initial presentation to the University of Alberta Head and Neck Oncology Clinic. RNA was extracted, purified and quantified from prospectively collected participant tissues, and ddPCR was performed with fluorescent probes detecting HPV-16 E6 and E7. Results from ddPCR were compared with p16 IHC performed by clinical pathology as standard of care. RESULTS: Head and neck tissues were prospectively obtained from 68 participants including 29 patients with OPSCC, 29 patients with non-OPSCC and 10 patients without carcinoma. 79.2% of patients with OPSCC were p16 positive. The sensitivity and specificity of ddPCR HPV E6/E7 compared with p16 IHC in OPSCC was 91.3 and 100%, respectively. The amount of target RNA used was ≤1 ng, 20-50 times lower than reported by other for RT-qPCR HPV E6/E7. CONCLUSIONS: The ddPCR of HPV E6/E7 is a novel and highly specific method of detecting HPV-16 in OPSCC. Cancer 2016;122:1544-51. © 2016 American Cancer Society.

Extracorporeal Lung Support as a Bridge to Diagnosis of Pulmonary Tumor Embolism.

Bridging to diagnosis is an emerging technique used in end-stage cardiorespiratory failure that prolongs a patient's life using various modalities of extracorporeal lung support (ECLS) to achieve antemortem diagnosis. Pulmonary tumor embolism occurs when cell clusters travel from primary malignancies through venous circulation to the lungs, causing respiratory failure through inflammatory and venoocclusive pathways. Due to its nonspecific symptomatology, pulmonary tumor embolism remains an elusive diagnosis antemortem. Herein, we bridge a patient who presented in acute respiratory failure to the diagnosis of pulmonary tumor embolism from a gastric signet-ring cell carcinoma using ECLS modalities including venoarterial extracorporeal membrane oxygenation and centrally cannulated Novalung pumpless extracorporeal lung assist. We demonstrate the utility of this approach in diagnostically uncertain cases in unstable patients who are potentially acceptable ECLS and transplant candidates.

Role of primary surgery in the treatment of advanced oropharyngeal cancer.

BACKGROUND: The purpose of this study was to compare survival outcomes of patients with advanced stage oropharyngeal squamous cell carcinoma (SCC) according to surgical and nonsurgical treatments, when stratified by smoking and p16 status. METHODS: We conducted a prospective longitudinal population-based study of 279 patients diagnosed with advanced oropharyngeal SCC. Patients were stratified by smoking and p16 status. RESULTS: There was no significant disease-specific survival (DSS) difference in combined modality treatment groups in nonsmokers that had p16-positive cancers, however, in smokers with p16-positive cancers, the DSS surgery + postoperative chemoradiotherapy (S+CRT) was significantly higher than chemoradiotherapy (CRT) alone. Patients who had p16-negative cancers had the highest DSS when treated with surgery + adjuvant therapy (S+RT)/CRT. Multivariate Cox regression analysis showed that increasing Eastern Cooperative Oncology Group (ECOG) score, smoking, p16 status, higher stage, and treatment with surgery protocols were significant determinants of survival. CONCLUSION: Primary surgical approaches offer the best survival outcomes in smokers with p16-positive cancers and in patients with p16-negative cancers. © 2015 Wiley Periodicals, Inc. Head Neck 38: E-E, 2016.

Association of keratinization with 5-year disease-specific survival in oropharyngeal squamous cell carcinoma.

IMPORTANCE: Keratinization is a histologic feature on hematoxylin-eosin staining associated with adverse outcomes in head and neck cancer, particularly oral cavity squamous cell carcinoma. However, the prognostic value of keratinization has not been demonstrated in oropharyngeal squamous cell carcinoma (OPSCC) in a large cohort of patients. OBJECTIVE: To quantify the prognostic value of keratinization in a large cohort of patients with OPSCC with subgroup analysis based on p16 status, basaloid differentiation, and smoking status. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cross-sectional study using a prospectively collected database that identified 208 patients with OPSCC diagnosed and treated at a single tertiary cancer center from 2002 to 2009. Tissue microarrays (TMAs) were generated from 208 patient specimens stained with hematoxylin-eosin and immunohistochemical markers. Digital images from stained TMAs were scored for the presence of keratinization and/or basaloid differentiation and for p16 status. INTERVENTIONS: Patients were treated with curative intent with surgery, radiation, and/or chemotherapy. MAIN OUTCOMES AND MEASURES: The primary outcome measure was 5-year disease-specific survival (DSS) in OPSCC according to keratinization. Univariate and multivariate survival analyses were performed to estimate survival according to histopathologic profile and smoking status. RESULTS: In the 208 samples, 96 were keratinizing and 112 were nonkeratinizing. Patients with keratinizing tumors were more likely to have advanced-stage disease and be p16 negative. Keratinization was independently associated with adverse outcomes. The 5-year DSS was significantly higher for nonkeratinizing tumors (63.3%) compared with keratinizing tumors (44.8%; P = .007). In subgroup analysis, nonkeratinization was associated with improved DSS in those with nonbasaloid and p16-negative tumors and in patients who were smokers. When stratifying patients based on keratinization, p16-status, and smoking status, patients with p16-negative keratinizing tumors who were smokers had the lowest 5-year DSS (26.7%). CONCLUSIONS AND RELEVANCE: Patients with nonkeratinized OPSCC have improved survival compared with those with keratinizing tumors. Information on keratinization is most useful prognostically in those who have p16-negative and nonbasaloid tumors and in patients who are smokers. Survival can be stratified using keratinization, p16 status, and smoking status.

COST ANALYSIS OF INTRA PROCEDURAL RAPID ON SITE EVALUATION OF CYTOPATHOLOGY WITH ENDOBRONCHIAL ULTRASOUND.

BACKGROUND: Rapid on site evaluation (ROSE) allows immediate processing and interpretation of the aspirate in the procedural suite. It improves diagnostic yield and lowers patient care costs. There are limited data on its cost-effectiveness with endobronchial ultrasound (EBUS). METHODS: We developed an economic model with two arms, no ROSE (our current practice) and simulated ROSE. To simulate ROSE, a cytopathologist retrospectively identified the first diagnostic slide in each case. Using a decision analytic modeling technique under a hospital diagnostic unit perspective, the benefits of simulated ROSE were estimated as cost-savings. The model input was estimated from actual data, consulting experts, and the literature. The benefits were estimated as cost savings per patient and for the province of Alberta per year. Due to differences in the procedure, sarcoidosis and cancer patients were analyzed separately. The costs are shown in 2012 Canadian dollars, CAD. RESULTS: In our model without ROSE, the procedure cost/patient was CAD 646.00(USD 523.32) for cancer and CAD 1,170.00 (USD 947.73) for sarcoidosis. With simulated ROSE cost savings of CAD 63.00(37.00 to 89.00) [USD 51.04(29.97 to 72.10)], CAD 544.00(490.00 to 598.00) [USD 440.65(397.05 to 484.44)] for cancer and sarcoidosis, respectively. Extrapolating this to provincial data, our model estimates that EBUS with ROSE would lead to savings of CAD 50,000.00(30,000 to 71,000) [USD 40,501.24 (24,300.75 to 57,531.34)] for cancer and CAD 109,000.00 (87,000 to 130,000) [USD 88,337.07 (70,546.45 to 105,313.04) for sarcoidosis. CONCLUSION: The use of ROSE with EBUS is cost saving. The projected savings were CAD 50,000.00 (USD 40,501.24) and CAD 109,000.00(USD 88,337.07) in cancer and sarcoidosis, respectively, for the province of Alberta, Canada.

Expression of DP2 (CRTh2), a prostaglandin D2 receptor, in human mast cells.

PGD2 has long been implicated in allergic diseases. Recent cloning of a second PGD2 receptor, DP2 (also known as CRTh2), led to a greater understanding of the physiological and pathophysiological implications of PGD2. PGD2 signaling through DP1 and DP2 mediates different and often opposite effects in many cell types of the immune system. Although mast cells (MC) are the largest source of PGD2 in the body, there is little information about their potential expression of DP2 and its functional significance. In this study, we show that tissue MC in human nasal polyps express DP2 protein, and that human MC lines and primary cultured human MC express mRNA as well as protein of DP2. By immunohistochemistry, we detected that 34% of MC in human nasal polyps expressed DP2. In addition, flow cytometry showed that 87% of the LAD2 human MC line and 98% of primary cultured human MC contained intracellular DP2. However, we could not detect surface expression of DP2 on human MC by single cell analysis using imaging flow cytometry. Blocking of endogenous PGD2 production with aspirin did not induce surface expression of DP2 in human MC. Two DP2 selective agonists, DK-PGD2 and 15R-15-methyl PGD2 induced dose-dependent intracellular calcium mobilization that was abrogated by pertussis toxin, but not by three DP2 selective antagonists. MC mediator release including degranulation was not affected by DP2 selective agonists. Thus, human MC express DP2 intracellularly rather than on their surface, and the function of DP2 in human MC is different than in other immune cells such as Th2 cells, eosinophils and basophils where it is expressed on the cell surface and induces Th2 cytokine and/or granule associated mediator release. Further studies to elucidate the role of intracellular DP2 in human MC may expand our understanding of this molecule and provide novel therapeutic opportunities.

Rac2 is involved in bleomycin-induced lung inflammation leading to pulmonary fibrosis.

BACKGROUND: Pulmonary fibrotic diseases induce significant morbidity and mortality, for which there are limited therapeutic options available. Rac2, a ras-related guanosine triphosphatase expressed mainly in hematopoietic cells, is a crucial molecule regulating a diversity of mast cell, macrophage, and neutrophil functions. All these cell types have been implicated in the development of pulmonary fibrosis in a variety of animal models. For the studies described here we hypothesized that Rac2 deficiency protects mice from bleomycin-induced pulmonary fibrosis. METHODS: To determine the role of Rac2 in pulmonary fibrosis we used a bleomycin-induced mouse model. Anesthetized C57BL/6 wild type and rac2-/- mice were instilled intratracheally with bleomycin sulphate (1.25 U/Kg) or saline as control. Bronchoalveolar lavage (BAL) samples were collected at days 3 and 7 of treatment and analyzed for matrix metalloproteinases (MMPs). On day 21 after bleomycin treatment, we measured airway resistance and elastance in tracheotomized animals. Lung sections were stained for histological analysis, while homogenates were analyzed for hydroxyproline and total collagen content. RESULTS: BLM-treated rac2-/- mice had reduced MMP-9 levels in the BAL on day 3 and reduced neutrophilia and TNF and CCL3/MIP-1α levels in the BAL on day 7 compared to BLM-treated WT mice. We also showed that rac2-/- mice had significantly lower mortality (30%) than WT mice (70%) at day 21 of bleomycin treatment. Lung function was diminished in bleomycin-treated WT mice, while it was unaffected in bleomycin-treated rac2-/- mice. Histological analysis of inflammation and fibrosis as well as collagen and hydroxyproline content in the lungs did not show significant differences between BLM-treated rac2-/- and WT and mice that survived to day 21. CONCLUSION: Rac2 plays an important role in bleomycin-induced lung injury. It is an important signaling molecule leading to BLM-induced mortality and it also mediates the physiological changes seen in the airways after BLM-induced injury.

Pulmonary ossification syndrome in a patient with chronic thromboembolic pulmonary hypertension.

Pulmonary ossification syndrome is a rare disease characterized by bone tissue formation in the lung parenchyma with or without bone marrow elements. This disorder, often under-recognized, can be idiopathic or secondary to an underlying chronic disorder such as chronic thromboembolic pulmonary hypertension. The pathogenesis involves tissue injury and an alkaline environment in which the precipitation of calcium salts enables alkaline phosphatase activity. This activates profibrogenic cytokines that convert fibroblasts into osteoblasts. Diagnosis can prove challenging and is based on clinical, radiographic and functional tests, and by tissue biopsy. Achieving an accurate and timely diagnosis is essential to avoid erroneous treatments due to misdiagnosis and to expand knowledge of its progression, prognosis and treatment. As the population and prevalence of chronic lung disease increases, it is likely that physicians will encounter more cases of pulmonary ossification.