Radon in Schools: A Brief Review of State Laws and Regulations in the United States

Exposure to Radon, a colorless, naturally occurring radioactive gas, is one of leading causes of lung cancer, and may pose a significant long-term risk for school age children. We examined the regulations and statutes in each US state related to radon in schools to delineate key features of policies and discrepancies among states that may have public health implications. Search terms such as "radon", "school", "mitigation", "certification", "licensing", and "radon resistant new construction" were used to scan current statutes from each state legislature's website and regulations from official state government websites for relevant regulatory and statutory requirements concerning radon in schools. State regulations related to the testing, mitigation, and public dissemination of radon levels in schools are inconsistent and the lack of nationwide indoor radon policy for schools may result in unacceptably high radon exposure levels in some US schools. We highlight the features and discrepancies of state laws and regulations concerning radon in schools, and offer several constructive means to reduce risks associated with radon exposure in school children.

Donor Preconditioning After the Onset of Brain Death With Dopamine Derivate n-Octanoyl Dopamine Improves Early Posttransplant Graft Function in the Rat

Heart transplantation is the therapy of choice for end-stage heart failure. However, hemodynamic instability, which has been demonstrated in brain-dead donors (BDD), could also affect the posttransplant graft function. We tested the hypothesis that treatment of the BDD with the dopamine derivate n-octanoyl-dopamine (NOD) improves donor cardiac and graft function after transplantation. Donor rats were given a continuous intravenous infusion of either NOD (0.882 mg/kg/h, BDD+NOD, n = 6) or a physiological saline vehicle (BDD, n = 9) for 5 h after the induction of brain death by inflation of a subdural balloon catheter. Controls were sham-operated (n = 9). In BDD, decreased left-ventricular contractility (ejection fraction; maximum rate of rise of left-ventricular pressure; preload recruitable stroke work), relaxation (maximum rate of fall of left-ventricular pressure; Tau), and increased end-diastolic stiffness were significantly improved after the NOD treatment. Following the transplantation, the NOD-treatment of BDD improved impaired systolic function and ventricular relaxation. Additionally, after transplantation increased interleukin-6, tumor necrosis factor TNF-α, NF-kappaB-p65, and nuclear factor (NF)-kappaB-p105 gene expression, and increased caspase-3, TNF-α and NF-kappaB protein expression could be significantly downregulated by the NOD treatment compared to BDD. BDD postconditioning with NOD through downregulation of the pro-apoptotic factor caspase-3, pro-inflammatory cytokines, and NF-kappaB may protect the heart against the myocardial injuries associated with brain death and ischemia/reperfusion.

Semifluorinated alkanes--a new class of excipients suitable for pulmonary drug delivery

INTRODUCTION

Semifluorinated alkanes (SFAs) are considered as diblock molecules with fluorocarbon and hydrocarbon segments. Unlike Perfluorocarbons (PFCs), SFAs have the potential to dissolve several lipophilic or water-insoluble substances. This makes them possibly suitable as new excipients for inhalative liquid drug carrier systems.

PURPOSE

The aim of the study was to compare physico-chemical properties of different SFAs and then to test their respective effects in healthy rabbit lungs after nebulisation.

METHODS

Physico-chemical properties of four different SFAs, i.e. Perfluorobutylpentane (F4H5), Perfluorohexylhexane (F6H6), Perfluorohexyloctane (F6H8) and Perfluorohexyldodecane (F6H12) were measured. Based on these results, aerosol characteristics of two potential candidates suitable as excipients for pulmonary drug delivery, i.e. F6H8 and F4H5, were determined by laser light diffraction. Tracheotomised and ventilated New Zealand White rabbits were nebulised with either a high- or a low dose of SFAs (F6H8(low/high) and F4H5(low/high)) or saline (NaCl). Ventilated healthy animals served as controls (Sham). Arterial blood gases, lung mechanics, heart rate and blood pressure were recorded prior to nebulisation and in 30 min intervals during the 6-h study period.

RESULTS

Out of the four SFAs studied initially, no satisfactory behaviour as a solvent has to be expected because of low lipophilicity for F6H6. Output rate during aerosolisation was very low for F6H12. F6H8 and F4H5 presented comparable aerosolisation characteristics and lipophilicity and were therefore tested in the in vivo model. Aerosol therapy, either SFAs or saline, impaired paO2/FiO2 ratio, dynamic lung compliance and respiratory mechanics in all groups, except for F4H5(low) group which behaved like the control group (Sham). F4H5(low) had no adverse effects on gas exchange or pulmonary mechanics.

CONCLUSIONS

Perfluorobutylpentane (F4H5) in a low-dose application may be suitable as a new inhalable excipient in SFA-based pulmonary drug delivery systems for lipophilic or water-insoluble substances.

Inhibition of neutrophil-mediated production of reactive oxygen species (ROS) by endothelial cells is not impaired in anti-neutrophil cytoplasmic autoantibodies (ANCA)-associated vasculitis patients

Leucocyte transendothelial migration is strictly regulated to prevent undesired inflammation and collateral damage of endothelial cells by activated neutrophils/monocytes. We hypothesized that in anti-neutrophil cytoplasmic autoantibodies (ANCA)-associated vasculitis (AAV) patients' dysregulation of this process might underlie vascular inflammation. Peripheral blood mononuclear cells (PBMC) and neutrophils from AAV patients (n = 12) and healthy controls (HC, n = 12) were isolated. The influence of human umbilical vein endothelial cells (HUVEC) on neutrophil/monocytes function was tested by N-formyl-methionyl-leucyl-phenyl-alanine (fMLP)- and phorbol 12-myristate 13-acetate (PMA)-mediated ROS production, degranulation and interleukin (IL)-8 production. In addition, the ability of lipopolysaccharide (LPS)-stimulated PBMC to produce tumour necrosis factor (TNF)-alpha in the presence or absence of HUVEC was tested. HUVEC inhibited ROS production dose-dependently by fMLP-stimulated neutrophils but did not influence degranulation. No differences between neutrophils from HC and AAV were found. However, in only one active patient was degranulation inhibited significantly by HUVEC only before cyclophosphamide treatment, but not 6 weeks later. Co-cultures of HUVEC with LPS-stimulated neutrophils/monocytes increased IL-8 production while TNF-alpha production was inhibited significantly. There was no apparent difference between AAV patients and HC in this respect. Our findings demonstrate that HUVEC are able to inhibit ROS and modulate cytokine production upon stimulation of neutrophils or monocytes. Our data do not support the hypothesis that endothelial cells inhibit ROS production of neutrophils from AAV patients inadequately. Impaired neutrophil degranulation may exist in active patients, but this finding needs to be confirmed.

Rosiglitazone reduces angiotensin II and advanced glycation end product-dependent sustained nuclear factor-kappaB activation in cultured human proximal tubular epithelial cells

Tubular damage is a major feature in the development of diabetic nephropathy. This study investigates the effects of the thiazolidindione rosiglitazone on angiotensin II and advanced glycation end product-induced tubular activation in human proximal tubular epithelial cells IN VITRO. Angiotensin II and advanced glycation end products, both induced a dose-dependent sustained activation of the redox-sensitive transcription factor, Nuclear Factor KAPPA B (NF-kappaB). Nuclear translocation of NF-kappaB was evident already after one hour and persistent for more than four days. Co-incubation of proximal tubular epithelial cells with rosiglitazone significantly reduced angiotensin II and advanced glycation end product-mediated generation of reactive oxygen species, angiotensin II-dependent advanced glycation end product formation, NF-kappaB activation, and NF-kappaB-dependent pro inflammatory gene expression. Most importantly, rosiglitazone effects on NFkappaB activation were maximal at later time points, indicating that rosiglitazone treatment confers long lasting renoprotective effects.

[The role of endothelial progenitor cells in sepsis]

In sepsis and septic shock a series of immunological events are initiated that alter endothelial function in the macrocirculation and microcirculation. Endothelial swelling, deformation and apoptosis with detachment from the vasculature occur and endothelial cells (EC) appear in the circulation. Simultaneous to these pathological processes, reconstitution of the endothelial layer is initiated which can occur via migration and proliferation of surrounding mature ECs. However, terminally differentiated ECs have a low proliferative potential, hence their capacity to substitute damaged endothelium is limited. Therefore, adequate vascular repair requires additional support. Many studies have now convincingly demonstrated that vascular maintenance, repair, angiogenesis and neovascularization are partly mediated by recruitment of endothelial progenitor cells (EPCs) from the basal membrane. However, it seems that EPCs play a pivotal role not only in re-endothelialization after vascular damage, but also after severe inflammation. Recently, evidence was found that EPCs are increasingly mobilized during sepsis and that this mobilization is associated with clinical outcome. In septic patients the number of EPCs was significantly higher than in controls and was correlated with survival and the concentration of cytokines. In summary EPCs may exert an important function as an endogenous repair mechanism to maintain the integrity of the endothelial layer by replacing denuded parts of the microcirculation or by stimulation of EC proliferation. Therefore, EPC enumeration seems to be a valuable prognostic and diagnostic marker for the outcome in these patients and the induction of enhanced EPC mobilization a therapeutic option.

Hypothermic preservation of lung allograft inhibits cytokine-induced chemoattractant-1, endothelial leucocyte adhesion molecule, vascular cell adhesion molecule-1 and intracellular adhesion molecule-1 expression

Organ dysfunction is a major clinical problem after lung transplantation. Prolonged cold ischaemia and reperfusion injury are believed to play a central role in this complication. The influence of cold preservation on subsequent warm reperfusion was studied in an isolated, ventilated and perfused rat lung. Rat lungs were flushed with cold Perfadex-solution and stored at 4 degrees C for different time periods. Thereafter lungs were perfused and ventilated for up to 3 h. Physiological parameters, production of inflammatory mediators and leucocyte infiltration were measured before and after perfusion. Lungs subjected to a cold ischaemia time of up to 6 h showed stable physiological conditions when perfused for 3 h. However, cold-ischaemia time beyond 6 h resulted in profound tissue oedema, thereby impairing ventilation and perfusion. Warm reperfusion and ventilation per se induced a strong inflammatory response, as demonstrated by a significant up-regulation of chemokines and adhesion molecules (cytokine-induced chemoattractant-1, intracellular adhesion molecule and endothelial leucocyte adhesion molecule), accompanied by enhanced leucocyte infiltration. Although the up-regulation of inflammatory mediators was blunted in lungs that were subjected to cold ischaemia, this did not influence leucocyte infiltration. In fact, cold ischaemia time correlated with leucocyte sequestration. Although cold preservation inhibits the expression of inflammatory mediators it does not affect leucocyte sequestration during warm reperfusion. Cold preservation might cause impairment of the endothelial barrier function, as evidenced by tissue oedema and profound leucocyte infiltration.

Effect of pre-treatment with catecholamines on cold preservation and ischemia/reperfusion-injury in rats

Treatment of organ donors with catecholamines reduces acute rejection episodes and improves long-term graft survival after renal transplantation. The aim of this study was to investigate the effect of catecholamine pre-treatment on ischemia/reperfusion (I/R)- and cold preservation injury in rat kidneys. I/R-injury was induced by clamping the left kidney vessels for 60 min along with a contralateral nephrectomy. Cold preservation injury was induced by storage of the kidneys for 24 h at +4 degrees Celsius in University of Wisconsin solution, followed by syngeneic transplantation. Rats were pre-treated with either dopamine (DA), dobutamine (DB), or norepinephrine (2, 5, and 10 microg/kg/min, each group) intravenously via an osmotic minipump for 24 h before I/R- and cold preservation injury. Pre-treatment with DA (2 or 5 microg/kg/min) and DB (5 microg/kg/min) improved recovery of renal function after I/R-injury and dose dependently reduced mononuclear and major histocompatibility complex class II-positive cells infiltrating the kidney after I/R-injury. One day after I/R-injury, upregulation of transforming growth factor (TGF)-beta 1 and 2 and phosphorylation of p42/p44 mitogen-activated protein kinases was observed in kidneys of animals treated with DA or DB. DA (5 microg/kg/min) and DB (5 microg/kg/min) pre-treatment reduced endothelial cell damage after 24 h of cold preservation. Only DA pre-treatment improved renal function and reduced renal inflammation after 24 h of cold preservation and syngeneic transplantation. Our results demonstrate a protective effect of pre-treatment with catecholamines on renal inflammation and function after I/R- or cold preservation injury. This could help to explain the potent organoprotective effects of catecholamine pre-treatment observed in human kidney transplantation.

Effekte von Dopamin auf die zelluläre und humorale Immunantwort von Patienten mit Sepsis

In vitro and in vivo studies have demonstrated that apart from its hemodynamic action dopamine can modulate immune responses. Dopamine reduces the synthesis of proinflammatory and induces the synthesis of anti-inflammatory mediators. Dopamine inhibits neurohormone synthesis, lymphocyte proliferation and platelet aggregation. It reduces the phagocytic activity of neutrophils and induces apoptosis. Particularly with regard to sepsis, where high serum dopamine levels are reached by enhanced endogenous production, exogenous application and impaired clearance, this immunomodulation may have a clinical impact. This review summarizes dopamine-mediated immunomodulating effects to advance the knowledge regarding dopamine as an immune regulator under septic conditions.

ANCA titres, even of IgG subclasses, and soluble CD14 fail to predict relapses in patients with ANCA-associated vasculitis

BACKGROUND

Antineutrophil cytoplasmic autoantibodies (ANCA) are presumed to reflect disease-activity and to be useful for guidance of immunosuppressive therapy of ANCA-associated systemic vasculitis (AASV), but with respect to conventional ANCA assays this is controversial. ANCA titres, measured in the IgG3 subclass and modern capture ELISAs, have been said to be superior predictors of relapses of AASV.

METHODS

In this retrospective study serial measurements of ANCA parameters and soluble CD14 (sCD14) were performed in 169 consecutive sera over a median of 21 months in 18 patients with AASV and related to disease activity, assessed by Birmingham Vasculitis Activity Score (BVAS) for new or deteriorated (BVAS1), and for chronic disease activity (BVAS2). Fourteen patients had Wegener's granulomatosis (WG) and were C-ANCA positive with Pr 3-antibodies and four patients had microscopic polyangiitis (MPA) with P-ANCA and MPO-antibodies. In WG patients ANCA by IIF, Pr 3-ELISA for IgG, IgG1, IgG3, IgG4 and sCD14 were measured, as well as capture ELISA for Pr 3, and in MPA patients ANCA by IIF, MPO-ELISA for IgG and IgG1, IgG3, IgG4, and sCD14 respectively. In eight patients, data collection started at diagnosis, in 10 patients at remission.

RESULTS

The parameters predicted neither the nine major relapses (increase of immunosuppression necessary), nor the 26 minor relapses (increase of BVAS1>2) with sufficient sensitivity (>80%) or specificity (> 90%90%), and they also failed to predict relapses within the following 2 months. ANCA-IgG3 and capture ELISA for Pr 3 were not advantageous for prediction of relapses (sensitivity 0.45 and 0.19 respectively), and sCD14 remained elevated in all samples irrespective of disease activity.

CONCLUSIONS

There is no rationale for serial measurements of ANCA in AASV. For changes of therapy, the ANCA parameters should only be used in conjunction with clinical information.

Prevention of chronic renal allograft rejection in rats with an oral endothelin A receptor antagonist

BACKGROUND

Chronic rejection is the most common cause of graft loss in renal transplantation. The pathomechanisms underlying chronic rejection are poorly understood, and no treatment has yet successfully been established. We hypothesized that, in analogy to models of reduced renal mass, the administration of a selective endothelin (ET) A receptor antagonist could improve the course of chronic rejection in renal allografts.

METHODS

Experiments were performed in the Fisher-to-Lewis rat model of chronic rejection. Lewis-->Lewis isografts served as controls. Animals were treated with either the oral selective ET-A receptor antagonist LU135252 (50 mg/kg/day) or vehicle. Animal survival, blood pressure, creatinine clearance, proteinuria, and urinary ET excretion were investigated for 24 weeks. Kidneys were removed for light microscopical evaluation, determination of ET mRNA expression and tissue protein concentration, and immunohistochemical assessment of cell surface markers.

RESULTS

Rats with chronic rejection showed an increase in renal ET mRNA synthesis and ET protein content. Treatment with LU135252 resulted in a significant improvement in survival after 24 weeks (0.92 vs. 0.38, P<0.01 by log-rank test). Creatinine clearance was higher in animals treated with the selective ET-A receptor antagonist (P<0.05). LU135252 had no influence on blood pressure and proteinuria. Selective ET-A blockade was associated with significantly less morphological changes and a significant reduction of expression of cell surface markers for macrophages (ED1), T cells (R73), and MHC II (F17-23-2).

CONCLUSION

The renal ET-A system plays an important role in the pathomechanisms underlying chronic renal allograft rejection, because the treatment with a selective ET-A receptor antagonist dramatically improves the course of chronic renal failure after allograft transplantation. These results offer a novel therapeutical option for treatment of chronic renal allograft rejection, for which so far no therapy is known.

The clinical significance of allospecific antibodies against endothelial cells detected with an antibody-dependent cellular cytotoxicity assay for vascular rejection and graft loss after renal transplantation

Serum samples of 64 consecutive patients who underwent renal transplantation in our institution were examined for the presence of antibody-dependent cellular cytotoxicity (ADCC) activity against endothelial cells (EC). From each patient serum samples were obtained immediately before transplantation and 1 week, 1 month and 1 year thereafter. The results were evaluated in the context of tests to measure donor-specific humoral immunity against lymphocytes and monocytes, and related to parameters of presensitization, graft survival, and histology. Sera from 10 patients were positive for ADCC on a panel of HLA-typed endothelial cells. In 8 patients sera were already positive before transplantation and remained positive thereafter. In 4 patients a positive crossmatch with donor T and B cells and monocytes could be observed after transplantation. In only one patient were these crossmatches positive before transplantation. A significant correlation was found between ADCC positivity and vascular rejection (P = 0.015); in addition graft survival was significantly better in the ADCC negative group vs. the positive group (P = 0.0004). These data demonstrate the significance of allospecific anti EC antibodies for the occurrence of vascular rejection and graft loss after renal transplantation.