Anthrax is a disease caused by the bacterium Bacillus anthracis, which results in high mortality in animals and humans. Although some of the mechanisms are already known such as asphyxia, extensive knowledge of molecular pathogenesis of this disease is deficient and remains to be further investigated. Lethal toxin (LT) is a major virulence factor of B. anthracis and a specific inhibitor/protease of mitogen-activated protein kinase kinases (MAPKKs). Anthrax LT causes lethality and induces certain anthrax-like symptoms, such as anemia and hypoxia, in experimental mice. Mitogen-activated protein kinases (MAPKs) are the downstream pathways of MAPKKs, and are important for erythropoiesis. This prompted us to hypothesize that anemia and hypoxia may in part be exacerbated by erythropoietic dysfunction. As revealed by colony-forming cell assays in this study, LT challenges significantly reduced mouse erythroid progenitor cells. In addition, in a proteolytic activity-dependent manner, LT suppressed cell survival and differentiation of cord blood CD34+-derived erythroblasts in vitro. Suppression of cell numbers and the percentage of erythroblasts in the bone marrow were detected in LT-challenged C57BL/6J mice. In contrast, erythropoiesis was provoked through treatments of erythropoietin, significantly ameliorating the anemia and reducing the mortality of LT-treated mice. These data suggested that suppressed erythropoiesis is part of the pathophysiology of LT-mediated intoxication. Because specific treatments to overcome LT-mediated pathogenesis are still lacking, these efforts may help the development of effective treatments against anthrax.

UV photodissociation of α-alanine was studied by parahydrogen matrix isolation infrared spectroscopy. The temporal behavior of Fourier transform infrared spectra revealed that UV irradiation at 213 nm yielded the HOCO radical as a direct photoproduct from the S 2 excited state. The concentration of HOCO quickly approached a steady state due to secondary photodissociation of HOCO to produce CO 2 + H or CO + OH. On the other hand, no photoproducts were detected by S 1 excitation at 266 nm. Irradiation of fully deuterated α-alanine at 213 nm yielded ∼2 times more cis-DOCO radicals than the lower energy isomer trans-DOCO, indicating that the conformation of the hydroxyl group is fairly well-preserved upon photodissociation of α-alanine. The present study suggests that HOCO may be a good tracer species in the search for amino acids in interstellar space.

Mycobacterium fortuitum group (M. fortuitum), also known as rapidly growing Mycobacteria, can cause pyogenic infections in human beings, most commonly in immunocompromised patients. Herein, we present a 40-year-old immunocompetent male patient who underwent planned excision of a sebaceous cyst in the abdominal wall. He suffered from tender erythematous lesions with purulent discharge around the healing wound that developed 2 weeks after surgery. Gram stain, bacterial and fungal culture results of the wound were negative. A diagnosis of nontuberculous mycobacteria was made from a wound culture from the area of operative debridement, which was subsequently confirmed to be M. fortuitum group using PCR-restriction fragment length polymorphism analysis of the hsp65 gene. The patient received 4 weeks of parenteral imipenem/cilastatin 500 mg every 6 hours and amikacin 500 mg every 12 hours, plus oral clarithromycin 500 mg twice daily, and the wound recovered completely. He was discharged and followed up regularly at our outpatient clinic, and continued taking oral ciprofloxacin and clarithromycin 500 mg twice daily for 6 months. This case highlights the importance of strict aseptic precautions even during minor procedures, and also the characteristics of M. fortuitum infections in immunocompetent patients, which usually develop as localized postsurgical wound infections. We also share our experience in successfully treating a M. fortuitum complicated skin and soft tissue infection.

Airglow emissions are a signature of chemical processes in the atmosphere and ionosphere. As their intensities are dependent on the densities and temperatures of the particle species involved in the chemical processes, airglow emissions can provide guidance for studying the variations of the relevant particle parameters (Clemesha et al., 1991;Takahashi et al., 1989). For this reason, airglow observations have guided studies of various dynamic processes in the upper atmosphere and lower ionosphere (

A number of recent studies have highlighted observational evidence of midnight brightness of the 630.0 nm nightglow, which is usually related to the midnight temperature maximum (MTM) effect. In this report, MTM-related enhancements of the 630.0 nm airglow around midnight are observed through images from the ISUAL/FORMOSAT-2 satellite. The data statistics are classified into three specific types (no-peak, single-peaked, and double-peaked events) and separated into the different seasons. In order to understand the influences of geomagnetic conditions, the statistical analyses are also separated into two regions. One is collected from the region whose geomagnetic equator is north of the geographic equator, and the other is collected from the region whose geomagnetic equator is south of the geographic equator. The results show that the single-peaked brightness often appears between the geographic equator and the geomagnetic equator. The double-peaked brightness appears simultaneously on the two sides of the region sandwiched by the two equators. Coupled with the summer-to-winter neutral wind generated by seasonal effects, one side of brightness could be enhanced or disappear due to the plasma moving along the field line. The no-peak events mainly occur close to May–July, which may be due to the effect of ionospheric annual anomalies. Overall, the statistical results for the occurrence rate show strong seasonal variations with different cycles at different longitudinal regions for all three types of events. Graphical Abstract