Genotyping of Pneumocystis carinii f. sp. hominis isolates in Japan based on nucleotide sequence variations in internal transcribed spacer regions of rRNA genes

Genotyping of Pneumocystis carinii (Pc) isolated from 24 bronchoalveolar lavage (BAL) fluid specimens in Japan was examined based on nucleotide sequence variations in internal transcribed spacer regions 1 and 2 (ITS1 and ITS2, respectively) of rRNA genes. We found 11 ITS1 genotypes including 2 novel ones and 11 ITS2 genotypes including 3 new ones. Combining the ITS1 and ITS2 genotypes resulted in 30 ITS genotypes, of which 10 are newly described in this report. Two or more genotypes in ITS regions in a specimen were observed in 16 of 24 patients. Our results will be of help for the epidemiological investigation of Pc infection.     

Paramagnetic artifact and safety criteria for human brain mapping

Biological effects of magnetic field and their safety criteria, especially effects of gradient magnetic field on the cerebral and pulmonary circulation during functional brain mapping are still unclear. Here we estimated that magnetically induced artifacts for the blood oxygenation level- and flow- based functional magnetic resonance imaging are less than 0.1%, and disturbance in the pulmonary circulation is less than 1.3% even if the field strength of magnetic resonance system is risen up to 10 tesla. These paramagnetic effects are considered to be small and harmless during human brain mapping.     

Mechanisms of synovial joint and articular cartilage formation: recent advances, but many lingering mysteries

Synovial joints are elegant, critically important, and deceptively simple biomechanical structures. They are comprised of articular cartilage that covers each end of the opposing skeletal elements, synovial fluid that lubricates and nourishes the tissues, ligaments that hold the skeletal elements in check, and a fibrous capsule that insulates the joints from surrounding tissues. Joints also exhibit an exquisite arrays of shapes and sizes, best exemplified by the nearly spherical convex femoral head articulating into a nearly spherical concave hip acetabulum, or a phalangeal joint with two condyles on the distal side articulating in reciprocally-shaped sockets on the opposing proximal side. Though few in number, joint tissues are highly specialized in structure and function. This is illustrated by articular cartilage with its unique extracellular matrix, unique biomechanical resilience, its largely avascular nature, and its ability to persist through life with minimal turnover of its cells and components. The fact that interest in synovial joints has remained unabated for decades is a reflection of their fundamental importance for organism function and quality of life, and for their susceptibility to a variety of acquired and congenital conditions, most importantly arthritis. This has led to many advances in this field that encompass molecular genetics to biomechanics to medicine. Regrettably, what continues to be poorly understood are the mechanisms by which synovial joints actually form in the developing embryo. If available, this information would be not only of indisputable biological interest, but would also have significant biomedical ramifications, particularly in terms of designing novel tissue regeneration or reconstruction therapies. This review focuses on recent advances in understanding the mechanisms of synovial joint formation in the limbs, and places and discusses the information within the context of classic studies and the many mysteries and questions that remain unanswered.     

Prenylated flavonoids from Moghania philippinensis

Five prenylated flavonoids, 8-(1,1-dimethylallyl)genistein (1), 5,7,3',4'-tetrahydroxy-2',5'-di(3-methylbut-2-enyl)isoflavone (2), 5,7,3'-trihydroxy-2'-(3-methylbut-2-enyl)-4',5'-(3,3-dimethylpyrano)isoflavone (3), (2R)-5,2',4'-trihydroxy-8,5'-di(3-methylbut-2-enyl)-6,7-(3,3-dimethylpyrano)flavanone (4a) and (2S)-5, 2', 4'-trihydroxy-8,5'-di(3-methylbut-2-enyl)-6,7-(3,3-dimethylpyrano)flavanone (4b), were isolated from the roots of Moghania philippinensis. The structures of these compounds were determined on the basis of spectroscopic and chemical means.     

Interrogating the Spatiotemporal Landscape of Neuromodulatory GPCR Signaling by Real-Time Imaging of cAMP in Intact Neurons and Circuits

1. Download high-res image (176KB)
2. Download full-size image

     

Reaction of human myeloperoxidase with hydrogen peroxide and its true catalase activity

The instability of human myeloperoxidase [EC 1.11.1.7] compound I, which was spontaneously reduced to compound II, and the abnormal stoichiometry of the reaction of myeloperoxidase with H2O2 were investigated. As to the former, a pretreatment of myeloperoxidase with H2O2 did not stabilize compound I, and no difference in its stability was observed between native (alpha 2 beta 2) and hemi (alpha beta) myeloperoxidase. From these results, it was thought that the instability of compound I was caused by neither the presence of endogenous donors nor the intramolecular reduction of compound I to compound II by the other heme in the native enzyme molecule. As for the latter, true catalase activity of myeloperoxidase was demonstrated by monitoring O2 evolution after the injection of H2O2 into the enzyme solution. Myeloperoxidase compound I reacted with H2O2 and returned to the ferric state with concomitant evolution of an O2 molecule. Accordingly, the abnormal stoichiometry of the reaction with H2O2 and a part of the instability of compound I can probably be ascribed to this true catalase activity.     

Evidence for a model of activation of central sigma systems

Evidence for a drug-induced activation of central sigma systems is presented. The model is the locomotor activation initiated by a subcutaneous (SC) challenge of 1.6 mg/kg of (+)-butaclamol, (+)-BUT, given 30 min before 10 mg/kg SC of (-)-N-allylnormetazocine, (-)-NAN, in Sprague-Dawley male rats which have been pretreated with four daily injections of 10 mg/kg SC of (-)-NAN. The locomotor activation is characterized by an initial 20 min period of retropulsion and sideways-circling followed by 90 to 100 min of forward locomotion. The locomotor syndrome is antagonized by 10 mg/kg of (+/-)-BMY 14802, 20 mg/kg of rimcazole, and 0.2 mg/kg of haloperidol, but not by 0.04 mg/kg of R(+)SCH23390, 100 mg/kg of S(-)sulpiride, 10 mg/kg of naltrexone, or 2.5 mg/kg of MR2266. The data suggest that the manifestation of the (+)-BUT/(-)-NAN-induced syndrome depends upon intact transmission at central sigma sites.