Niche adaptation and genome expansion in the chlorophyll d-producing cyanobacterium Acaryochloris marina

Acaryochloris marina is a unique cyanobacterium that is able to produce chlorophyll d as its primary photosynthetic pigment and thus efficiently use far-red light for photosynthesis. Acaryochloris species have been isolated from marine environments in association with other oxygenic phototrophs, which may have driven the niche-filling introduction of chlorophyll d. To investigate these unique adaptations, we have sequenced the complete genome of A. marina. The DNA content of A. marina is composed of 8.3 million base pairs, which is among the largest bacterial genomes sequenced thus far. This large array of genomic data is distributed into nine single-copy plasmids that code for >25% of the putative ORFs. Heavy duplication of genes related to DNA repair and recombination (primarily recA) and transposable elements could account for genetic mobility and genome expansion. We discuss points of interest for the biosynthesis of the unusual pigments chlorophyll d and α-carotene and genes responsible for previously studied phycobilin aggregates. Our analysis also reveals that A. marina carries a unique complement of genes for these phycobiliproteins in relation to those coding for antenna proteins related to those in Prochlorococcus species. The global replacement of major photosynthetic pigments appears to have incurred only minimal specializations in reaction center proteins to accommodate these alternate pigments. These features clearly show that the genus Acaryochloris is a fitting candidate for understanding genome expansion, gene acquisition, ecological adaptation, and photosystem modification in the cyanobacteria.     

Lectin-like oxidized LDL receptor-1 is a cell-adhesion molecule involved in endotoxin-induced inflammation

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is a major endothelial receptor for oxidized low-density lipoprotein, and is assumed to play a proatherogenic role in atherosclerosis. LOX-1 expression is induced by inflammatory cytokines as well as by proatherogenic stimuli. LOX-1 protein binds agedapoptotic cells, activated platelets, and bacteria, suggesting that it may have diverse activities in vivo. Here, we reveal a role for LOX-1 in endotoxin-induced inflammation. In a model of endotoxemia, injection of a high dose of endotoxin into rats induced leukopenia within 1 h and death of the animals within 24 h. Preadministration of anti-LOX-1 antibody reduced the degree of leukopenia and completely rescued the animals, whereas control IgG did not. In a model of low-dose endotoxin-induced uveitis, anti-LOX-1 antibody efficiently suppressed leukocyte infiltration and protein exudation. In situ videomicroscopic analyses of leukocyte interactions with retinal veins revealed that anti-LOX-1 antibody reduced the number of rolling leukocytes and increased the velocity of rolling, suggesting that LOX-1 functions as a vascular tethering ligand. The ability of LOX-1 to capture leukocytes under physiologic shear was confirmed in an in vitro flow model. Thus, LOX-1 is an adhesion molecule involved in leukocyte recruitment and may represent an attractive target for modulation of endotoxin-induced inflammation.     

Changes in the isolated delayed component as an endpoint of catheter ablation in arrhythmogenic right ventricular cardiomyopathy: predictor for long-term success

Introduction: Although successful ablation of ventricular tachycardia (VT) is feasible in arrhythmogenic right ventricular cardiomyopathy (ARVC), long-term recurrence is common. The aim of this study was to assess the usefulness of a change in the isolated delayed component (IDC) as an endpoint of the catheter ablation in ARVC.
Methods and Results: Eighteen patients (48 ± 11 years) with ARVC were studied. Detailed endocardial mapping of the right ventricle (RV) was performed during sinus rhythm. IDCs were recorded in 16 patients and the latest IDCs were related to the VT circuit. Catheter ablation was carried out in the areas with the IDCs. At the end of the session, the IDC was electrically dissociated in one, disappeared in five, exhibited second-degree block in one, was significantly delayed (≥50 ms) in three, and remained unchanged in six. The change in the IDC was correlated with the change in the type II/III late potentials in the signal-averaged electrocardiography (ECG) and the inducibility of the clinical VT after the ablation. During a follow-up of 61 ± 38 months, VT recurred in six. The patients with a changed IDC had a significantly lower VT recurrence than those with no IDC or an unchanged IDC (P < 0.02).
Conclusion: In patients with ARVC, (1) the IDCs during sinus rhythm are related to the clinical VT and can be a target for the ablation, (2) a change in the IDC can be used as an endpoint, and (3) qualitative analyses of the serial signal-averaged ECGs may be useful for the long-term follow-up.     

Asian variant of CD5+ intravascular large B-cell lymphoma with splenic infarction

A 57-year-old man was admitted with fever and epigastralgia, and presented with splenomegaly and pancytopenia. A CT scan revealed splenic infarctions. There were no lymphadenopathies, skin lesions, or neurological abnormalities. A splenectomy was performed. Bone marrow involvement with hemophagocytosis was noted. The diagnosis of Asian variant of intravascular diffuse large B-cell lymphoma was based on intravascular and sinusoidal distribution of large CD5+ B cells. The patient died of the disease 11 months after onset. To our knowledge, this is the first report of AIVL that presented with splenic infarction. This distinct lymphoma should be included in the differential diagnosis of splenic infarction.     

Specific IgE for wheat in tear fluid of patients with allergic conjunctivitis

Context: Allergy to hydrolyzed wheat protein in facial soap has become a major social issue in Japan. It has been reported that the most frequent early symptoms of allergy to hydrolyzed wheat protein in soap are allergic conjunctivitis and rhinitis, while wheat-dependent exercise-induced anaphylaxis can be induced by long-term use.

Objective: We evaluated the relation between tear fluid levels of specific IgE for wheat and the features of allergic conjunctivitis.

Methods: A prospective, non-randomized, cross-sectional study was conducted in 103 patients with moderate to severe allergic conjunctivitis (allergic group) and 20 age- and sex-matched healthy control subjects (control group). Specific IgE for wheat was measured in tear fluid with an immunochromatography assay, and a skin prick test (SPT) was also performed. Symptoms (sneezing, rhinorrhea, nasal obstruction, ocular itching, and lacrimation) were assessed in each subject along with the activities of daily living (ADL) score and the total ocular symptom score for allergic conjunctivitis. A severity score (0, 1, 2, or 3) was assigned for various changes of the palpebral and bulbar conjunctiva, as well as for limbal and corneal lesions associated with allergic conjunctivitis.

Results: The IgE positive rate and specific IgE score were both higher in the allergic group than in the control group (71.8% versus 40.0% and 1.9?±?0.7 versus 1.4?±?0.5). A positive SPT for wheat was also more frequent in the allergic group than in the control group (6.8% versus 0.0%). Within the allergic group, patients with a positive SPT had higher specific IgE scores than patients with a negative SPT (3.3?±?0.5 versus 1.8?±?0.6, p?r?=?0.665), tearing (r?=?0.672), and the total ocular symptom score (r?=?0.204). Wheat IgE in tear fluid was also correlated with the severity of rhinitis symptoms, including sneezing (r?=?0.610), nose blowing (r?=?0.640), and nasal obstruction (r?=?0.677). Furthermore, the tear fluid wheat IgE score was correlated with five objective features of allergic conjunctivitis (p?Conclusions: These results suggest that wheat allergy may be involved in the development of allergic conjunctivitis.     

Results of a survey of community-acquired-pneumonia and evaluation of old and new Japanese Respiratory Society guidelines]

We evaluated the usefulness of domestic and foreign guidelines for the diagnosis and treatment of patients with community-acquired-pneumonia at 23 institutions in 6 prefectures of the Tohoku Area, from December 2003 to November 2004. Based on the old and new Japanese Respiratory Society (JRS) guidelines, we evaluated severity, clinical efficacy and detection of atypical pneumonia. As for severity, the old guidelines led to the diagnosis of an excessive number of 'severe' cases. On the other hand, patients were appropriately diagnosed as having mild, moderate, severe, or very severe disease based on the new JRS guidelines (2005). The severity classification often correlated with the Pneumonia Severity Index (PSI) of the IDSA guidelines. The efficacy rate for patients who were prescribed the recommended drug according to the old JRS guidelines was 85.7% and for those who did not use the recommended drug it was 68.7% (p < 0.001).     

Antiprothrombin antibody testing: detection and clinical utility

Anticardiolipin antibody (aCL), anti-beta2 glycoprotein I antibodies, and lupus anticoagulant (LA) are the only laboratory tests considered within the revised criteria for the classification of the antiphospholipid syndrome (APS). Recently, antibodies against phosphatidylserine-prothrombin complex (aPS/PT) have been detected, and these antibodies, rather than antibodies against prothrombin alone, are closely associated with APS and LA. The sensitivity and specificity of aPS/PT for the diagnosis of APS were assessed in a population of patients with a variety of autoimmune disorders. aCL and aPS/PT have similar diagnostic value for APS, therefore aPS/PT should be further explored, not only for research purposes but also as a candidate for one of the laboratory criteria for the classification of the APS.