Detection ofPneumocystis carinii with direct fluorescence antibody and calcofluor white stain

Summary Direct fluorescence monoclonal antibody stain (DFA) was compared prospectively, with calcofluor white (CFW) stain for the diagnosis ofPneumocystis carinii in 163 respiratory specimens from 97 patients. The patient population included persons with HIV infection (58%), bone marrow transplant recipients (10%), immunosuppressed patients owing to chemotherapy (21%) and others (11%). Nineteen specimens including 12 sputa, six bronchoalveolar lavage fluids (BALs) and one induced sputum were positive by DFA. In contrast, only six sputa, and five BALs were positive by CFW. All specimens positive by CFW were also positive by DFA. Of 86 sputa that were negative by either method 29 were followed by more invasive sample collections. Three specimens were followed by induced sputum collection, 18 by BAL, six by lung biopsy, and two by pleural fluid aspiration. All the subsequent induced sputa, pleural fluids, and lung biopsies were negative by both methods. However, four of 18 subsequent BALs (22%) were positive by both methods, provided at least two CFW stained slides were examined per specimen. Except for expectorated sputum, it is concluded that CFW is a rapid and inexpensive test to detectP. carinii in most respiratory specimens.

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Nachweis vonPneumocystis carinii mit direkter Antikörper-Fluoreszenztechnik (DFA) und Calcofluor Weiß-Färbung

Zusammenfassung Im prospektiven Vergleich wurde die diagnostische Aussagekraft der direkten Antikörper-Fluoreszenz-Technik und der Calcofluor-Weiß (CFW)-Färbung zum Nachweis vonPneumocystis carinii in 163 Proben aus dem unteren Respirationstrakt von 97 Patienten geprüft. Die Gruppe setzte sich aus Patienten mit HIV-Infektion (58%), Knochenmarktransplantations-Empfängern (10%), nach Chemotherapie immunsupprimierten Patienten (21%) und anderen (11%) zusammen. Mit DFA-Technik waren 19 Proben positiv; darunter waren 12 Sputumproben, sechs bronchoalveoläre Lavage (BAL)-Flüssigkeiten und ein induziertes Sputum. Mit CFW-Färbung waren sechs Sputumproben und fünf BAL-Proben positiv. Alle mit CFW positiven Proben waren auch mit DFA positiv. Eine erneute Probenahme mit invasiveren Methoden erfolgte in 29 von 86 mit beiden Nachweis-Verfahren negativen Fällen. In drei Fällen wurde induziertes Sputum gewonnen, in 18 Fällen eine BAL, in sechs Fällen eine Lungenbiopsie und in zwei Fällen eine Pleurapunktion durchgeführt. Alle in der Folge gewonnenen induzierten Sputa, Pleuraflüssigkeiten und Lungenbiopsien waren mit beiden Methoden negativ. Doch in vier der 18 BAL-Flüssigkeiten (22%) wurdeP. carinii nachgewiesen, dabei waren mindestens zwei mit CFW gefärbte Ausstriche pro Probe untersucht worden. Mit Ausnahme von Spontansputum eignet sich die CFW-Färbung als einfaches und billiges Verfahren bei den meisten Proben aus den tiefen Atemwegen zum Nachweis vonP. carinii.

     

Cerium oxide nanoparticles attenuate monocrotaline induced right ventricular hypertrophy following pulmonary arterial hypertension

Cerium oxide (CeO₂) nanoparticles have been posited to exhibit potent anti-oxidant activity which may allow for the use of these materials in biomedical applications. Herein, we investigate whether CeO₂ nanoparticle administration can diminish right ventricular (RV) hypertrophy following four weeks of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH). Male Sprague Dawley rats were randomly divided into three groups: control, MCT only (60 mg/kg), or MCT + CeO₂ nanoparticle treatment (60 mg/kg; 0.1 mg/kg). Compared to the control group, the RV weight to body weight ratio was 45% and 22% higher in the MCT and MCT + CeO₂ groups, respectively (p < 0.05). Doppler echocardiography demonstrated that CeO₂ nanoparticle treatment attenuated monocrotaline-induced changes in pulmonary flow and RV wall thickness. Paralleling these changes in cardiac function, CeO₂ nanoparticle treatment also diminished MCT-induced increases in right ventricular (RV) cardiomyocyte cross sectional area, β-myosin heavy chain, fibronectin expression, protein nitrosylation, protein carbonylation and cardiac superoxide levels. These changes with treatment were accompanied by a decrease in the ratio of Bax/Bcl2, diminished caspase-3 activation and reduction in serum inflammatory markers. Taken together, these data suggest that CeO₂ nanoparticle administration may attenuate the hypertrophic response of the heart following PAH.     

The Biology of Veganism: Plasma Metabolomics Analysis Reveals Distinct Profiles of Vegans and Non-Vegetarians in the Adventist Health Study-2 Cohort

It is unclear how vegetarian dietary patterns influence plasma metabolites involved in biological processes regulating chronic diseases. We sought to identify plasma metabolic profiles distinguishing vegans (avoiding meat, eggs, dairy) from non-vegetarians (consuming ≥28 g/day red meat) of the Adventist Health Study-2 cohort using global metabolomics profiling with ultra-performance liquid chromatography mass spectrometry (UPLC-MS/MS). Differences in abundance of metabolites or biochemical subclasses were analyzed using linear regression models, adjusting for surrogate and confounding variables, with cross-validation to simulate results from an independent sample. Random forest was used as a learning tool for classification, and principal component analysis was used to identify clusters of related metabolites. Differences in covariate-adjusted metabolite abundance were identified in over 60% of metabolites (586/930), after adjustment for false discovery. The vast majority of differentially abundant metabolites or metabolite subclasses showed lower abundance in vegans, including xanthine, histidine, branched fatty acids, acetylated peptides, ceramides, and long-chain acylcarnitines, among others. Many of these metabolite subclasses have roles in insulin dysregulation, cardiometabolic phenotypes, and inflammation. Analysis of metabolic profiles in vegans and non-vegetarians revealed vast differences in these two dietary groups, reflecting differences in consumption of animal and plant products. These metabolites serve as biomarkers of food intake, many with potential pathophysiological consequences for cardiometabolic diseases.     

Endothelial reticulon-4B (Nogo-B) regulates ICAM-1-mediated leukocyte transmigration and acute inflammation

The reticulon (Rtn) family of proteins are localized primarily to the endoplasmic reticulum (ER) of most cells. The Rtn-4 family, (aka Nogo) consists of 3 splice variants of a common gene called Rtn-4A, Rtn-4B, and Rtn-4C. Recently, we identified the Rtn-4B (Nogo-B) protein in endothelial and smooth muscle cells of the vessel wall, and showed that Nogo-B is a regulator of cell migration in vitro and vascular remodeling and angiogenesis in vivo. However, the role of Nogo-B in inflammation is still largely unknown. In the present study, we use 2 models of inflammation to show that endothelial Nogo-B regulates leukocyte transmigration and intercellular adhesion molecule-1 (ICAM-1)-dependent signaling. Mice lacking Nogo-A/B have a marked reduction in neutrophil and monocyte recruitment to sites of inflammation, while Nogo-A/B(-/-) mice engrafted with wild-type (WT) bone marrow still exhibit impaired inflammation compared with WT mice engrafted with Nogo-A/B(-/-) bone marrow, arguing for a critical role of host Nogo in this response. Using human leukocytes and endothelial cells, we show mechanistically that the silencing of Nogo-B with small interfering RNA (siRNA) impairs the transmigration of neutrophils and reduces ICAM-1-stimulated phosphorylation of vascular endothelial-cell cadherin (VE-cadherin). Our results reveal a novel role of endothelial Nogo-B in basic immune functions and provide a key link in the molecular network governing endothelial-cell regulation of diapedesis.     

Both homo and heterodimers of Marek's disease virus encoded Meq protein contribute to transformation of lymphocytes in chickens

Marek' disease virus serotype-1, also know as Gallid herpesvirus 2 (GaHV-2), elicits T-cell lymphomas in chickens. The GaHV-2 genome encodes an oncoprotein, Meq, with similarity to the Jun/Fos family of proteins. We have previously shown that Meq homodimers are not sufficient to induce lymphomas in chickens. In this study, we investigated the role of Meq heterodimers in the pathogenicity of GaHV-2 by generating a chimeric meq gene, which contains the leucine zipper region of Fos (meqFos). A recombinant virus containing the meqFos gene in place of parental meq, rMd5-MeqFos, was not capable of transforming chicken lymphocytes, indicating that heterodimerization of Meq alone is not sufficient for transformation. In addition, the recovery of the oncogenic phenotype by a recombinant virus encoding one copy each of MeqGCN (homodimer) and MeqFos (heterodimer) conclusively demonstrates that both homo and heterodimerization of Meq are required for oncogenesis.