Multimessenger observations of a flaring blazar coincident with high-energy neutrino IceCube-170922A

Previous detections of individual astrophysical sources of neutrinos are limited to the Sun and the supernova 1987A, whereas the origins of the diffuse flux of high-energy cosmic neutrinos remain unidentified. On 22 September 2017, we detected a high-energy neutrino, IceCube-170922A, with an energy of ~290 tera–electron volts. Its arrival direction was consistent with the location of a known γ-ray blazar, TXS 0506+056, observed to be in a flaring state. An extensive multiwavelength campaign followed, ranging from radio frequencies to γ-rays. These observations characterize the variability and energetics of the blazar and include the detection of TXS 0506+056 in very-high-energy γ-rays. This observation of a neutrino in spatial coincidence with a γ-ray–emitting blazar during an active phase suggests that blazars may be a source of high-energy neutrinos.

Primary Sjogren syndrome: clinical and immunopathologic features

Primary Sjogren syndrome is an autoimmune condition in which dry eyes (keratoconjunctivitis sicca) and dry mouth (xerostomia) result from lymphocytic infiltration of lacrimal and salivary glands. Clinical and laboratory features of 60 primary Sjogren syndrome patients seen at our clinic during the past three years are presented. These patients illustrate the wide spectrum of extraglandular features that may occur as a result of lymphoid infiltration of lung, kidney, skin, stomach, liver, and muscle. They further emphasize the difficulty in classifying a patient as primary or secondary Sjogren syndrome (ie, sicca symptoms associated with systemic lupus erythematosus, rheumatoid arthritis, or scleroderma), particularly early in the disease course. As an initial step in understanding the pathogenesis, the lymphocytes that infiltrate the salivary glands and lymph nodes were characterized by using monoclonal antibodies that recognize distinct lymphocyte subsets and by using in vitro functional assays. These studies have demonstrated that affected tissues have infiltrates of T cells with helper/inducer activity and with a high frequency of "activation antigens." The immunohistologic techniques are useful in differentiating "benign" and "pseudolymphoma" lesions (both due predominantly to T cells) from non-Hodgkin lymphoma (usually due to B-cell infiltrates). Although there is no "cure" for primary Sjogren syndrome patient's symptoms may be significantly improved by measures aimed at prevention of ocular and dental complications and by the recognition of extraglandular features that may be amenable to specific treatment.

Update in Sjögren syndrome

Sjögren syndrome (SS), the second most common autoimmune rheumatic disease, refers to keratoconjunctivitis sicca and xerostomia resulting from immune lymphocytes that infiltrate the lacrimal and salivary glands. However, differential diagnosis remains confusing due to the high prevalence of vague symptoms of dryness, fatigue, and myalgias in the general population. The problems of diagnosis are further compounded by the finding of "positive" antinuclear antibodies in a high percent of the general population. Unless minor salivary gland biopsies are read by experienced observers, nonspecific changes of sialadenitis are frequently confused with the focal lymphocytic infiltrates that are characteristic of SS. The distinction between fibromyalgia patients with low titer antinuclear antibodies and primary SS remains difficult. Even in patients fulfilling strict criteria for SS, the genomic search for critical genes has proven difficult due to the multigenic pattern of inheritance and strong role of currently undefined environmental factors. No single environmental factor has been detected in the majority of SS patients. SS-like syndrome has been detected in certain patients with HTLV-1 and hepatitis C infection, providing clues to pathogenesis. Even in SS patients with marked sicca symptoms, minor salivary gland biopsy shows that almost 50% of glandular cells are still detected on biopsy. These results imply the importance of immune factors such as cytokines and autoantibodies in decreasing neuro-secretory circuits and induction of glandular dysfunction. Of potential importance, an antibody against muscarinic M3 receptor that can decrease secretory function when injected into rodents is frequently found in the sera of SS patients. Newly developed topical and oral therapies can ease the oral and ocular dryness. Orally administered agonists of the muscarinic M3 receptor (pilocarpine and cevimeline) have recently been approved by the US Food and Drug Administration to increase salivary secretion. Topical ocular use of low-dose corticosteroids or cyclosporin may decrease conjunctival surface inflammation. In a Phase II double-blind study, orally administered interferon alpha (150 U) led to improved saliva flow and symptoms. In pregnant patients with evidence of fetal distress, oral dexamethasone is preferred because this agent crosses the placenta effectively. In animal models, antagonists of tumor necrosis factor and inhibitors of de novo pyrimidine synthesis appear promising.

Elevation of tricuspid regurgitant jet velocity, a marker for pulmonary hypertension in children with sickle cell disease

BACKGROUND

Pulmonary hypertension (PHTN) is a potentially life-threatening complication, detected by echocardiographic evidence of elevated tricuspid regurgitant velocity (TRV). This condition has been described in adults with sickle cell disease (SCD) and other hemolytic disorders; however, there is little information on the occurrence of this condition in pediatric patients.

METHODS

Records for pediatric SCD patients were retrospectively reviewed to determine clinical characteristics and co-morbidities of patients with elevated TRV on echocardiograms obtained under steady state conditions as an outpatient. Correlation of TRV > or =2.5 m/sec with age, sex, type of SCD, number of outpatient echocardiograms per patient, episodes of vasoocclusive crisis (VOC) and acute chest syndrome (ACS), mean hemoglobin and reticulocyte count, asthma, obstructive sleep apnea, cerebrovascular disease (CVD), and hydroxyurea therapy was determined.

RESULTS

Of 224 SCD patients, 44 had outpatient echocardiographic measurement of TRV. Patients (11 of 44) (26.2%) with TRV > or =2.5 m/sec were compared to 31 patients without elevated TRV. Significant differences were noted for percent with HbSS disease (P = 0.041), CVD (P = 0.021), hemoglobin (P = 0.003), % reticulocytes (P = 0.037), and number of echocardiograms performed (P < 0.001). No significant differences were observed for gender, age, asthma, or frequency of VOC and ACS.

CONCLUSIONS

Elevated TRV, a surrogate marker for PHTN, occurs in children with SCD and is associated with low hemoglobin, elevated reticulocyte count, and cerebral vasculopathy. Appropriate screening by echocardiography can lead to detection and treatment that may reduce TRV and potentially reverse the disease process, prevent the increased morbidity and mortality associated with PHTN.

Long-term treatment with oral N-acetylcysteine: affects lung function but not sputum inflammation in cystic fibrosis subjects. A phase II randomized placebo-controlled trial

PURPOSE

To evaluate the effects of oral N-acetylcysteine (NAC), which replenishes systemic glutathione, on decreasing inflammation and improving lung function in CF airways.

METHODS

A multicenter, randomized, double-blind proof of concept study in which 70 CF subjects received NAC or placebo orally thrice daily for 24 weeks.

ENDPOINTS

primary, change in sputum human neutrophil elastase (HNE) activity; secondary, FEV(1) and other clinical lung function measures; and safety, the safety and tolerability of NAC and the potential of NAC to promote pulmonary hypertension in subjects with CF.

RESULTS

Lung function (FEV(1) and FEF(25-75%)) remained stable or increased slightly in the NAC group but decreased in the placebo group (p=0.02 and 0.02). Log(10) HNE activity remained equal between cohorts (difference 0.21, 95% CI -0.07 to 0.48, p=0.14).

CONCLUSIONS

NAC recipients maintained their lung function while placebo recipients declined (24 week FEV1 treatment effect=150 mL, p<0.02). However no effect on HNE activity and other selected biomarkers of neutrophilic inflammation were detected. Further studies on mechanism and clinical outcomes are warranted.

Bronchiolitis obliterans in children

Bronchiolitis obliterans (BO) in children is a relatively rare diagnosis. The increase in lung and bone marrow transplantation in children, however, has led to a heightened interest in BO, as this is one of the important complications of those procedures. This article will discuss BO as an entity that can follow any of several illnesses or toxic exposures, in addition to following allogeneic lung or bone marrow transplantation. The complex and incompletely understood pathology, pathogenesis, and molecular pathology involved in BO remain the subject of ongoing investigations. As the prognosis for BO is uncertain and treatment is often unsuccessful, the continued need for the recognition of surrogate markers for BO in patients at risk and the development of better forms of therapy are paramount. This review will describe our current understanding of BO, and will call attention to those research areas that require continuing efforts in order to prevent or treat this entity.

Current issues in the diagnosis and treatment of Sjögren's syndrome

Modification of the European Cooperative Group (EEC) criteria for Sjögren's Syndrome (SS) should lead to less confusion in diagnosis and therapeutic trials. The proposed EEC modification will require either a positive minor salivary gland biopsy or a positive autoantibody against Sjögren's-associated A (Ro) or B (La) antigen. This modification will decrease the proportion of women fulfilling EEC criteria from 3-5% to about 0.5%, which is similar to San Diego and San Francisco criteria. Genetic studies have shown increased frequency of alleles for peptide transporter genes TAP1 (0101) and TAP2 (0101) genes as well as tumor necrosis factor microsatellite a2 alleles. Although these markers confer markedly increased risk, they are found in only a small proportion of patients. An increased frequency of drug (antibiotic) allergy and other allergic manifestations appears present in patients with SS and may be linked to HLA-DR3. Hepatitis C as a cause of sicca symptoms, positive anti-nuclear autoantibodies, and mixed cryoglobulinemia is increasingly reported in different parts of the world. Antibodies against muscarinic M3 receptor and expression of costimulatory molecules (CD80 and CD86) by ductal epithelial cells may play a role in pathogenesis. Treatment with pilocarpine is effective in double-blind trials and low dose oral alpha interferon looks promising in initial open studies. In pregnant patients who exhibit evidence of neonatal heart block, treatment with dexamethasone is preferred over prednisone, since the placenta is unable to metabolically activate the latter compound.

Obesity, inflammation, and asthma severity in childhood: data from the National Health and Nutrition Examination Survey 2001-2004

BACKGROUND

The prevalences of asthma and obesity in children have increased significantly during the past 2 decades. The basis for the relationship between pediatric asthma and obesity is not well established.

OBJECTIVES

To explore the association between obesity and asthma severity in children and adolescents and to test whether obesity-induced inflammation, as characterized by serum C-reactive protein (CRP), is associated with increased severity of asthma.

METHODS

Retrospective cohort analysis of interview, physical examination, and laboratory test data from participants younger than 20 years in 2 rounds of the National Health and Nutrition Examination Survey (2001-2002 and 2003-2004). We also performed generalized ordered logistic regression to evaluate the effect of body mass index (BMI) z score and CRP level on asthma severity, controlling for the impact of age, sex, race, income, insurance, and tobacco smoke exposure.

RESULTS

Of the 77 million individuals younger than 20 years represented by this weighted sample, 19% met the study-defined criteria for asthma; most cases were defined as mild (11%) or moderate (6%); 2% had severe asthma. In multivariable models, elevated BMI z scores (odds ratio, 1.12; 95% confidence interval, 1.05-1.21) were associated with worse asthma severity. Elevated CRP level was associated with obesity (P < .001) and asthma severity (odds ratio, 1.33; 95% confidence interval, 1.16-1.52).

CONCLUSIONS

Higher BMI z scores and elevated serum CRP levels are associated with increased asthma severity. These findings highlight the importance of controlling for inflammation when considering the role of obesity and provide support for the hypothesis that obesity-induced inflammation may contribute to greater asthma severity.

Increased mortality after pulmonary fungal infection within the first year after pediatric lung transplantation

BACKGROUND

Risk factors, morbidity and mortality from pulmonary fungal infections (PFIs) within the first year after pediatric lung transplant have not previously been characterized.

METHODS

A retrospective, multicenter study from 1988 to 2005 was conducted with institutional approval from the 12 participating centers in North America and Europe. Data were recorded for the first post-transplant year. The log-rank test assessed for the association between PFI and survival. Associations between time to PFI and risk factors were assessed by Cox proportional hazards models.

RESULTS

Of the 555 subjects transplanted, 58 (10.5%) had 62 proven (Candida, Aspergillus or other) or probable (Aspergillus or other) PFIs within the first year post-transplant. The mean age for PFI subjects was 14.0 years vs 11.4 years for non-PFI subjects (p < 0.01). Candida and Aspergillus species were recovered equally for proven disease. Comparing subjects with PFI (n = 58) vs those without (n = 404), pre-transplant colonization was associated with PFI (hazard ratio [HR] 2.0; 95% CI 0.95 to 4.3, p = 0.067). Cytomegalovirus (CMV) mismatch, tacrolimus-based regimen and age >15 years were associated with PFI (p < 0.05). PFI was associated with any prior rejection higher than Grade A2 (HR 2.1; 95% CI 1.2 to 3.6). Cystic fibrosis, induction therapy, transplant era and type of transplant were not associated with PFI. PFI was independently associated with decreased 12-month survival (HR 3.9, 95% CI 2.2 to 6.8).

CONCLUSIONS

Risk factors for PFI include Grade A2 rejection, repeated acute rejection, CMV-positive donor, tacrolimus-based regimen and pre-transplant colonization.

American Society of Transplantation executive summary on pediatric lung transplantation

Lung transplantation in children poses distinctly different challenges from those seen in the adult population. This consensus statement reviews the experience in the field of pediatric lung transplantation and highlights areas that deserve further investigation.

Inhaled versus systemic antibiotics and airway inflammation in children with cystic fibrosis and Pseudomonas

RATIONALE

Inhaled tobramycin has been shown to transiently clear Pseudomonas from lower airways in early cystic fibrosis (CF), but does not markedly reduce lung inflammation, a key factor in disease progression.

OBJECTIVE

Test the hypothesis that systemic antibiotics are more effective than inhaled antibiotics for reducing lower airways inflammation.

METHODS

Clinically stable CF children with recent Pseudomonas were randomized to receive 4 weeks of inhaled tobramycin or 2 weeks of systemic antibiotics (intravenous ceftazidime and tobramycin). Bronchoalveolar lavage fluid was obtained just before and 4-6 weeks after treatment. The primary outcome was change in % neutrophils in lavage fluid.

RESULTS

Fifteen subjects (inhaled = 6, systemic = 9) completed the protocol. Three Systemic Group subjects could not have central venous access established and were treated with oral ciprofloxacin (plus inhaled tobramycin) for 2 weeks as an alternative "systemic" regimen, per protocol. Groups were well matched in age, markers of disease severity, and initial % neutrophils. The Systemic Group showed a modest median change in percent neutrophils (-7%) which was not statistically significant compared to inhaled (+5.4%, P = 0.07). However, the Systemic Group had significantly greater reductions in total cells (-50% vs. -3%, P < 0.01) and neutrophils (-74% vs. -10%, P = 0.02) per ml lavage fluid. Both groups had reduced bacterial quantity after treatment, but there was no significant difference between groups.

CONCLUSIONS

In clinically stable children with CF, systemic antibiotics result in greater short-term reduction in lower airways inflammation than inhaled antibiotics.

Screening for PTLD in lung and heart-lung transplant recipients by measuring EBV DNA load in bronchoalveolar lavage fluid using real time PCR

Pediatric L-HLTx recipients are at risk for developing PTLD with the lung being a primary site of disease. We hypothesized that BALF is a better sample than peripheral blood for measuring EBV DNA load in this high-risk population. Archived BALF specimens from pediatric L-HLTx recipients with and without PTLD were assayed for EBV DNA load using a quantitative real time TaqMan PCR assay. These values were compared with values determined in peripheral blood by a competitive PCR assay. Fifty-five BALF specimens from 16 L-HLTx patients were evaluated. Three patients with PTLD had mean BALF EBV DNA load values almost 50-fold higher than subjects without PTLD (4.6 x 10(5) copies/mL vs. 1.0 x 10(4) copies/mL). Patients who were EBV seronegative pretransplantation (i.e., high risk for PTLD) had elevated EBV DNA load values vs. patients who were EBV seropositive pretransplantation, regardless of the diagnosis of PTLD (mean values of 3.2 x 10(5) copies/mL vs. 1.1 x 10(4) copies/mL). Lastly, BALF analysis identified all subjects with PTLD, whereas peripheral blood analysis identified only one of these cases. Therefore, it can be concluded that monitoring EBV DNA load in BALF following L-HLTx facilitates detection of PTLD in high-risk patients and may be superior to peripheral blood assays.

Human bronchial epithelial cells secrete laminin 5, express hemidesmosomal proteins, and assemble hemidesmosomes

Epithelial cells attach to the basement membrane through adhesive contacts between the basal cells of the epithelium and the proteins of the extracellular matrix (ECM). The hemidesmosome (HD) is a specialized cell-ECM contact, that mediates the attachment of the epithelial cell basal surface to the ECM. In bronchial epithelial cells, the protein components that constitute the HD have not been demonstrated. Using immunohistochemical techniques, we determined that normal human bronchial epithelial (NHBE) cells express the HD cell surface integrin alpha6beta4 and produce laminin 5, the ECM protein associated with HDs. Furthermore, expression of the HD-associated structural proteins, bullous pemphigoid antigens 1 (BPAG 1) and 2 (BPAG 2), was demonstrated in NHBE cells by immunofluorescence microscopy and immunoblot analyses. In addition, we confirmed the presence of laminin 5 in the basement membrane (BM) of bronchial epithelial biopsy specimens and of BP230, BP180, and the alpha6beta4 integrin heterodimer at the site of bronchial epithelial cell-ECM interaction in vivo. Finally, using electron microscopy, we were able to demonstrate intact HDs in a glutaraldehyde-fixed NHBE cell monolayer. These findings suggest that bronchial epithelium forms HDs and that the laminin 5-alpha6beta4 integrin interaction may be important in stabilizing epithelial cell adhesion to the BM in the lung.

Keratinocyte growth factor stimulates bronchial epithelial cell proliferation in vitro and in vivo

Airway epithelial cell (AEC) proliferation is crucial to the maintenance of an intact airway surface and the preservation of host defenses. The factors that regulate AEC proliferation are not known. Keratinocyte growth factor (KGF), also known as FGF-7, is a member of the fibroblast growth factor family and a known epithelial cell mitogen. We studied the influence of KGF on the growth of cultured human bronchial epithelial cells and on bronchial cells of rats treated with KGF in vivo. First, we demonstrated the mRNA for the KGF receptor (KGFR) in both normal human bronchial epithelial (NHBE) cells and BEAS-2B cells (a human bronchial epithelial cell line). KGF caused a dose-dependent increase in DNA synthesis, as assessed by thymidine incorporation, in both cell types, with a maximal twofold increase in NHBE cells after 50 ng/ml KGF (P < 0.001). KGF also induced a doubling in NHBE cell number at 10 ng/ml (P < 0.001). Finally, we determined the effect of intratracheal administration of KGF to rats on proliferation of AEC in vivo. Measuring bromodeoxyuridine (BrdU) incorporation in AEC nuclei, KGF increased BrdU labeling of rat AEC in both large and small airways by approximately threefold compared with PBS-treated controls (P < 0.001). Thus KGF induces proliferation of bronchial epithelial cells both in vitro and in vivo.

Intensive care management of the patient with cystic fibrosis

Cystic fibrosis was previously thought to be a disease of childhood. With a better understanding of this condition along with improvements in therapy, patients with cystic fibrosis are now living well into adulthood. The aim of this article is to familiarize the intensive care unit physician with cystic fibrosis care, to discuss complications associated with cystic fibrosis specifically related to the intensive care unit, and to detail the current recommendations for the clinical management of the patient with cystic fibrosis. With advancing disease, the most severely affected organs are the lungs. Obstruction, infection, and inflammation contribute to the decline of pulmonary function, ultimately leading to death. Some patients may be eligible for lung transplantation, but choosing wisely will affect posttransplant survival. Because other organs are affected by the genetic defect and associated treatments, serious complications related to the liver, pancreas, intestines, and kidneys must be considered by the intensivist faced with a patient with cystic fibrosis. As practitioners, the fact that not all patients will survive and help our patients and families gracefully through the end-of-life process should be accepted.

Ozone effects on the immediate-phase response to allergen in the nasal airways of allergic asthmatic subjects

Epidemiologic and clinical trials have suggested that exposure to ozone increases airway hyperresponsiveness and inflammatory response to inhaled nasal allergen challenge in allergic asthmatic subjects. Previous studies have demonstrated an increased late-phase response to nasal allergen challenge; however, the early-phase response is unknown. We sought to characterize the early-phase response by measuring mast-cell inflammatory mediators and cellular influx at time points immediately following ozone exposure and subsequent allergen challenge. A cohort of mild, asymptomatic dust mite--sensitive asthmatic subjects was identified. Each subject underwent two separate exposures to both 0.4 ppm ozone and clean air in a randomized manner. Nasal lavage was performed before and after each exposure. Nasal allergen was then administered to a defined clinical end point, followed by nasal lavage. Differential cell counts and mast-cell products were identified in each lavage specimen. The mast-cell mediators tryptase and prostaglandin D2 were analyzed, as was a marker of epithelial cell permeability, albumin. Although allergen produced an increase in early-onset mediator release (mast cell-derived), no enhancement was noted after exposure to ozone. Neutrophil and eosinophil inflammatory mediators were not increased after ozone exposure or enhanced after allergen exposure, although ozone did enhance eosinophilic influx after exposure to allergen. Ozone exposure does not promote early-phase--response mediator release or enhance the response to allergen challenge in the nasal airways of extrinsic asthmatic subjects. Ozone, however, may promote an inflammatory cell influx, which helps induce a more significant late-phase response in this population.

Refractory hypercalcemia in an infant secondary to talc pleurodesis resolving after renal transplantation

Talc pleurodesis is the definitive therapy of recurrent pneumothorax and has not been associated with metabolic complications. We report an anephric male infant who developed severe hypercalcemia 6 months following talc pleurodesis for recurrent peritoneal dialysis-related hydrothorax. The etiology of hypercalcemia was related to persistently elevated 1,25-dihydroxyvitamin D(3) (1,25[OH]2D) levels. The source appeared to be the extrarenal production of 1,25(OH)2D from macrophages in a large thoracic talc granuloma. Hypercalcemia was controlled with a combination of a low calcium diet, low calcium dialysis, ketoconazole and hydroxychloroquine, but elevated 1,25(OH)2D levels persisted. At 32 months of age the child underwent renal transplantation with alemtuzumab pre-conditioning. The hypercalcemia resolved immediately, with normalization of serum 1,25(OH)2D levels and without hypercalciuria. This case demonstrates that hypercalcemia is a potential complication of talc pleurodesis from the extrarenal production of 1,25(OH)2D and that alemtuzumab, a monoclonal antibody directed against the CD52 antigen (which is expressed on almost all macrophages), may have a role in the treatment of hypercalcemia associated with granulomatous conditions.

Ready-to-Use Supplemental Food for Nutritional Supplementation in Cystic Fibrosis

Undernutrition is common in cystic fibrosis (CF) and is correlated with long-term outcomes, yet current nutritional interventions have not demonstrated consistent improvements in energy intake, and subsequently, growth. Development of novel nutritional interventions to increase energy intake is essential to improve clinical outcomes of individuals with CF. Ready-to-use supplemental food (RUSF) is a modifiable, inexpensive, palatable, safe, and nutrient-dense food for treatment or prevention of acute malnutrition in developing countries. Utilizing a linear-programming tool we identified 6 RUSF formulations with sufficient nutrient density (495 kcal/100 g), protein, and fat for children with CF. Palatability was established by a taste-trial and affirmed by a 2-wk tolerability assessment that demonstrated consistent consumption and tolerance of the RUSF. Although preliminary, this study demonstrates the potential for developing RUSF as a nutritional supplement for increasing energy intake in children with CF.

Approaches to the treatment of Sjögren's syndrome

Sjögren's syndrome (SS) is a systemic autoimmune disease characterized by complaints of sicca symptoms (dry eye and mouth) and can be associated with other autoimmune diseases (rheumatoid arthritis, systemic lupus erythematosus, progressive systemic sclerosis, etc). As a result, SS can be difficult to diagnose. Currently, there are several criteria standards for SS, including the San Diego criteria and the European Study Group criteria. According to the San Diego criteria, the incidence of SS is about 0.5%, whereas for the European Study Group it ranges from 3% to 5%. This almost 10-fold difference in SS incidence has led to confusion for both the clinician and researcher. The tearing reflex involves a neural loop in which afferent nerve signals from the ocular surface are relayed centrally to the medulla. The input from the afferent nerves is then processed and sent back via efferent nerves stimulating blood vessels and secretory glands to provide and pump water for tears. Immune factors, such as cytokines, have a profound effect on the tearing mechanism by damaging secretory glands and releasing antibodies to influence the response of muscarinic M3 receptors. Thus, the interaction of neural and immune factors affects the secretory response of glands and contributes to the pathogenesis of SS sicca symptoms. The recent development of muscarinic agonists, such as pilocarpine and cevimeline, serves an important step in recognizing the interaction between the immune and neuroendocrine systems.