Cytomegalovirus as an Insidious Pathogen Causing Duodenitis

A 60-year-old woman with rheumatoid arthritis treated with methotrexate for a decade complained of slight epigastric discomfort. A positive cytomegalovirus (CMV) antigenemia test indicated the probability of CMV-related gastrointestinal infection, for which esophagogastroduodenoscopy was performed. Endoscopic findings showed a non-specific duodenal mucosal lesion;however, pathological investigation revealed evidence of CMV duodenitis. There is scarce information on the clinical and pathological features of CMV-related duodenitis, likely due to its low prevalence. CMV infection in the upper gastrointestinal tract should be considered as a differential diagnosis in high-risk individuals, particularly those with symptoms relating to the digestive system. Biopsy examinations are preferable for the definitive diagnosis of CMV gastrointestinal infection, even without specific endoscopic features

Hepatitis B Virus e Antigen Physically Associates With Receptor-Interacting Serine/Threonine Protein Kinase 2 and Regulates IL-6 Gene Expression

We previously reported that hepatitis B virus (HBV) e antigen (HBeAg) inhibits production of interleukin 6 by suppressing NF-κB activation. NF-κB is known to be activated through receptor-interacting serine/threonine protein kinase 2 (RIPK2), and we examined the mechanisms of interleukin 6 regulation by HBeAg. HBeAg inhibits RIPK2 expression and interacts with RIPK2, which may represent 2 mechanisms through which HBeAg blocks nucleotide-binding oligomerization domain-containing protein 1 ligand-induced NF-κB activation in HepG2 cells. Our findings identified novel molecular mechanisms whereby HBeAg modulates intracellular signaling pathways by targeting RIPK2, supporting the concept that HBeAg could impair both innate and adaptive immune responses to promote chronic HBV infectio

Large Faraday effect of borate glasses with high Tb³⁺ content prepared by containerless processing

Borate glasses containing a large amount of Tb³⁺ ions have been prepared by containerless processing. The content of Tb₂O₃ reached 60 mol%. The glass bearing the highest content of Tb³⁺ ions showed a large Faraday effect; the Verdet constant was 234 rad/T m. Annealing of the glasses in H₂/N₂ atmosphere resulted in a low optical absorption coefficient, leading to an extremely large magneto-optical figure of merit that was ∼1.7 times higher than that of Tb₃Ga₅O₁₂ single crystal

A Model of the Spectral Evolution of Pulsar Wind Nebulae

Recent observations suggest that many old pulsar wind nebulae (PWNe) are bright TeV gamma-ray sources without a strong X-ray counterpart. In this paper, we study the spectral evolution of PWNe taking into account the energy which was injected when they were young for old PWNe. We model the evolution of the magnetic field and solve for the particle distribution inside a uniformly expanding PWN. The model is calibrated by fitting the calculated spectrum to the observations of the Crab Nebula at an age of a thousand years. We find that only a small fraction of the injected energy from the Crab Pulsar goes to the magnetic field, consistent with previous studies. The spectral evolution model of the Crab Nebula shows that the flux ratio of TeV gamma-rays to X-rays increases with time, which implies that old PWNe are faint at X-rays, but not at TeV gamma-rays. The increase of this ratio is primarily because the magnetic field decreases with time and is not because the X-ray emitting particles are cooled more rapidly than the TeV gamma-ray emitting particles. Our spectral evolution model matches the observed rate of the radio flux decrease of the Crab Nebula.Comment: 5 pages, 3 figures. Proc. of the 2009 Fermi Symposium, Washington, DC, Nov 2-5; eConf Proceedings C09112

Endoscopic Manifestations and Clinical Characteristics of Cytomegalovirus Infection in the Upper Gastrointestinal Tract

We retrospectively analyzed the cases of 14 patients (9 women, 5 men, mean age: 51.6 years) with cytomegalovirus (CMV) involvement in the esophagus, stomach, and/or duodenum diagnosed at a single center, to determine their endoscopic features and clinical backgrounds. Thirteen patients (92.9%) had hematologic disease; the other had rheumatoid arthritis. Of the former, 12 patients underwent allogeneic hematopoietic stem cell transplantation, and 9 of these patients had graft-versus-host disease (GVHD) before undergoing esophagogastroduodenoscopy (EGD). All 14 patients had been taking one or more immunosuppressive agents including cyclosporine (n=10), corticosteroids (n=9), mycophenolic acid (n=6), tacrolimus (n=3), and methotrexate (n=1). Tests for CMV antigenemia were positive in 11 patients (78.6%). EGD examinations revealed esophageal (n=3), gastric (n=9), and duodenal involvement (n=6). Macroscopically, esophageal lesions by CMV infection presented as redness (n=1), erosions (n=1), and ulcers (n=1). Gastric lesions manifested as redness (n=7), erosions (n=3), exfoliated mucosa (n=2), and verrucous erosions (n=1). Mucosal appearances in the duodenum varied: redness (n=2), ulcers (n=2), multiple erosions (n=2), single erosion (n=1), edema (n=1). CMV was detected even in the intact duodenal mucosa (n=1). In conclusion, physicians must recall the relevance of CMV infection when any mucosal alterations exist in the upper gastrointestinal tract of immunosuppressed patients