Physical analysis of the energy transducing reaction in mitochondria

As is generally known, the energy transducing reaction in mitochondria is of highly complicated one. Free energy produced by transferring electrons from substrate to oxygen, where many dehydrogenases and respiratory chain of mitochondria are concerned, is transduced to ATP formation or utilized for the ion accmulation reaction, synthesis of various substances, reversal electron transport and the mechanochemical changes of mitochondria. The mechanism of these energy trasducing reactions which is supposed to be closely related with each other, has not yet been clarified. The authors tried to solve these biological energy transducing mechnism by applying physical circuit theory in electronics and elucidate that the energy transduction occurring in mitochondria can be explained theoretically. And some unknown but possible reaction have been postulated from such a physical consideration.</p

Cell adhesion to substratum and activation of tyrosine kinases are essentially required for G1/S phase transition in BALB/c 3T3 fibroblasts

AbstractCell adhesion to substratum and activation of tyrosine kinases are essential for the progression of cell cycle through G1 phase in mammalian cells. The kinetic studies of mouse BALB/c 3T3 fibroblasts showed that serum was no longer required for the progression of G1/S phase transition. In contrast, cell adhesion was essentially required in late GI phase, especially at the period of G1/S transition. Among the kinase inhibitors used to elucidate the signal transduction caused by cell adhesion, tyrosine kinase inhibitors, genistein and herbimycin A, blocked the G1/S transition most effectively when cells were exposed to the inhibitors at the period of GI/S transition. Cell adhesion was not critically required for cells to undergo DNA synthesis once they had passed the G1/S boundary, and the effects of tyrosine kinase inhibitors on the progression of S phase were also not critical. The expressions of histone H2B and dihydrofolate reductase (DHFR) genes (S phase specific genes) and also the transcription factor E2F-1 gene (an activator of DHFR gene) were suppressed when cells were cultured without adhesion or exposed to the tyrosine kinase inhibitors. These results suggest that cell adhesion to substratum plays an important role in the G1/S phase transition of mouse BALB/c 3T3 fibroblasts through the activation of tyrosine kinases other than growth factor receptor-tyrosine kinases

日本の特別支援教育対象児のための小学校参加チェックリストの開発

東京都立大

Validation of radiative transfer computation with Monte Carlo method for ultra-relativistic background flow

We developed a three-dimensional radiative transfer code for an ultra-relativistic background flow-field by using the Monte Carlo (MC) method in the context of gamma-ray burst (GRB) emission. For obtaining reliable simulation results in the coupled computation of MC radiation transport with relativistic hydrodynamics which can reproduce GRB emission, we validated radiative transfer computation in the ultra-relativistic regime and assessed the appropriate simulation conditions. The radiative transfer code was validated through two test calculations: (1) computing in different inertial frames and (2) computing in flow-fields with discontinuous and smeared shock fronts. The simulation results of the angular distribution and spectrum were compared among three different inertial frames and in good agreement with each other. If the time duration for updating the flow-field was sufficiently small to resolve a mean free path of a photon into ten steps, the results were thoroughly converged. The spectrum computed in the flow-field with a discontinuous shock front obeyed a power-law in frequency whose index was positive in the range from 1 to 10 MeV. The number of photons in the high-energy side decreased with the smeared shock front because the photons were less scattered immediately behind the shock wave due to the small electron number density. The large optical depth near the shock front was needed for obtaining high-energy photons through bulk Compton scattering. Even one-dimensional structure of the shock wave could affect the results of radiation transport computation. Although we examined the effect of the shock structure on the emitted spectrum with a large number of cells, it is hard to employ so many computational cells per dimension in multi-dimensional simulations. Therefore, a further investigation with a smaller number of cells is required for obtaining realistic high-energy photons with multi-dimensional computations

Villous Tumor of the Urinary Bladder Resembling Low-grade Mucinous Neoplasm of the Appendix

AbstractMucinous neoplasms of the urinary tract are very rare. We present a 63-year-old-women who had a sessile papillary villous tumor in urinary bladder. Although transurethral resection of the bladder tumor (TURBT) was performed, the villous tumor repetitively recurred and gradually spread to the entire surface of bladder lumen. Histopathologic and immunohistochemical examination showed that the lesion was very similar to low-grade mucinous neoplasm arising in appendix vermiformis. There are no reports on appendiceal metaplasia of urinary bladder mucosa. In this case, we describe this unprecedented neoplasm as “villous tumor of the urinary bladder resembling low-grade mucinous neoplasm of the appendix.

The combination therapy with alfacalcidol and risedronate improves the mechanical property in lumbar spine by affecting the material properties in an ovariectomized rat model of osteoporosis

<p>Abstract</p> <p>Background</p> <p>We conducted the present study to investigate the therapeutic effects of a combination treatment of alfacalcidol (ALF) and risedronate (RIS) on the bone mechanical properties of bone and calcium (Ca) metabolism using an ovariectomized (OVX) rat model of osteoporosis.</p> <p>Methods</p> <p>Female Wistar rats were OVX- or sham-operated at 40 weeks of age. Twelve weeks post-surgery, rats were randomized into seven groups: 1) sham + vehicle, 2) OVX + vehicle, 3) OVX + ALF 0.025 μg/kg/day, 4) OVX + ALF 0.05 μg, 5) OVX + RIS 0.3 mg, 6) OVX + RIS 3.0 mg, 7) OVX + ALF 0.025 μg + RIS 0.3 mg. Each drug was administered orally five times a week for 12 weeks. After treatment, we evaluated the mechanical properties of the lumbar vertebra and femoral midshaft. In the lumbar vertebra, structural and material analyses were performed using micro-computed tomography (micro-CT) and microbeam X-ray diffraction (micro-XRD), respectively. Biochemical markers in serum and urine were also determined.</p> <p>Results</p> <p>(1) With respect to improvement in the mechanical strength of the lumbar spine and the femoral midshaft, the combination treatment of ALF and RIS at their sub-therapeutic doses was more effective than each administered as a monotherapy; (2) In the suppression of bone resorption and the amelioration of microstructural parameters, the effects of ALF and RIS were considered to be independent and additive; (3) The improvement of material properties, such as microstructural parameters and the biological apatite (Bap) c-axis orientation, contributed to the reinforcement of spinal strength; and (4) The combination treatment of ALF and RIS normalized urinary Ca excretion, suggesting that this treatment ameliorated the changes in Ca metabolism.</p> <p>Conclusion</p> <p>These results demonstrate that the combination treatment of ALF and RIS at their sub-therapeutic doses can improve the mechanical properties of the spine as well as the femur and ameliorate changes in Ca metabolism in an animal model of osteoporosis, suggesting that the combination treatment of ALF and RIS has a therapeutic advantage over each monotherapy for the treatment of osteoporosis.</p

Heme-dependent autophosphorylation of a heme sensor kinase, ChrS, from Corynebacterium diphtheriae reconstituted in proteoliposomes

AbstractCorynebacterium diphteriae employs the response regulator, ChrA, and the sensor kinase, ChrS, of a two-component signal transduction system to utilize host heme iron. Although ChrS is predicted to encode a heme sensor, the sensing mechanism remains to be characterized. In this report, ChrS expressed in Eshcherichia coli membranes was solubilized and purified using decylmaltoside. ChrS protein incorporated into proteoliposomes catalyzed heme-dependent autophosphorylation by ATP. Other metalloporphyrins and iron did not stimulate kinase activity. The UV–Vis spectrum of hemin in the ChrS–proteoliposomes indicated that heme directly interacts with ChrS. This is the first functional reconstitution of a bacterial heme-sensing protein

CD4/CD8 Double-negative Mycosis Fungoides: A Case Report and Literature Review

Mycosis fungoides, the most common subtype of cutaneous T-cell lymphoma, displays a broad spectrum of clinical, histological and phenotypic variants with different prognostic impacts. The classic immunophenotype is CD3+/CD4+/CD45RO+memory T cells. CD4/CD8 double-negative mycosis fungoides is rare. Here we describe the clinicopathological features of CD4/CD8 double-negative mycosis fungoides in a 55-year-old female with a review of the literature. Although the CD4/CD8 double-negative phenotype appears to be associated with an unusual clinical presentation, it does not appear to confer prognostic significance

Cefazolin-containing poly(ε-caprolactone) sponge pad to reduce pin tract infection rate in rabbits

AbstractIn our previous study, a fibroblast growth factor-2 (FGF-2)–apatite composite layer coated on titanium screws effectively prevented pin tract infection in rabbits because of enhanced wound healing; however, the FGF-2–apatite composite layers did not completely prevent pin tract infection. Thus, we recently developed a poly(ε-caprolactone) (PCL) sponge pad embedded with cefazolin sodium (+CEZ), which has a fast-acting bactericidal effect. The pad is placed on the skin around the screws. The purpose of this study was to determine the anti-infective efficacy of the +CEZ pad on the pin–skin interface of the FGF-2–apatite-coated titanium screws. The +CEZ pads were prepared by mixing PCL and CEZ in 1,4-dioxane, followed by freeze-drying and compaction. They were analyzed regarding their surface structure, in vitro CEZ release profile, and bactericidal activity. The FGF-2–apatite-coated screws were implanted percutaneously in bilateral rabbit proximal tibial metaphyses—with and without the +CEZ pad—for 4 weeks (n = 20). The + CEZ pads consisted of a porous matrix of PCL in which CEZ was embedded. The CEZ-release profile showed an initial burst on Day 1 and a sustained release lasting for 30 days. The +CEZ pad retained its bactericidal activity against Staphylococcus aureus after preincubation on an agar plate for 7 days. Based on visual inspection, the pin tract infection rate was successfully reduced from 72.2% to 15.0% with the +CEZ pad (p < 0.05), which reduced the bacterial count, especially S. aureus (p < 0.05). The histological inflammation rate of the soft tissues was also significantly lower with the +CEZ pad than without it (p < 0.05). The pin tract infection rate was reduced to one-fifth with the +CEZ pad. Using it as described improves infection resistance during percutaneous implantation