Regulation of pH attenuates toxicity of a byproduct produced by an ethanologenic strain of Sphingomonas sp. A1 during ethanol fermentation from alginate

Marine macroalgae is a promising carbon source that contains alginate and mannitol as major carbohydrates. A bioengineered ethanologenic strain of the bacterium Sphingomonas sp. A1 can produce ethanol from alginate, but not mannitol, whereas the yeast Saccharomyces paradoxus NBRC 0259–3 can produce ethanol from mannitol, but not alginate. Thus, one practical approach for converting both alginate and mannitol into ethanol would involve two-step fermentation, in which the ethanologenic bacterium initially converts alginate into ethanol, and then the yeast produces ethanol from mannitol. In this study, we found that, during fermentation from alginate, the ethanologenic bacterium lost viability and secreted toxic byproducts into the medium. These toxic byproducts inhibited bacterial growth and killed bacterial cells and also inhibited growth of S. paradoxus NBRC 0259–3. We discovered that adjusting the pH of the culture supernatant or the culture medium containing the toxic byproducts to 6.0 attenuated the toxicity toward both bacteria and yeast, and also extended the period of viability of the bacterium. Although continuous adjustment of pH to 6.0 failed to improve the ethanol productivity of this ethanologenic bacterium, this pH adjustment worked very well in the two-step fermentation due to the attenuation of toxicity toward S. paradoxus NBRC 0259–3. These findings provide information critical for establishment of a practical system for ethanol production from brown macroalgae

Effect of Subcultivation of Human Bone Marrow Mesenchymal Stem on their Capacities for Chondrogenesis, Supporting Hematopoiesis, and Telomea Length

Effects of subcultivation of human bone marrow mesenchymal stem cells on their capacities for chondrogenesis and supporting hematopoiesis, and telomea length were investigated. Mesenchymal stem cells were isolated from human bone marrow aspirates and subcultivated several times at 37℃ under a 5% CO2 atmosphere employing DMEM medium containing 10% FCS up to the 20th population doubling level (PDL). The ratio of CD45- CD105+ cells among these cells slightly increased as PDL increased. However, there was no marked change in the chondrogenic capacity of these cells, which was confirmed by expression assay of aggrecan mRNA and Safranin O staining after pellet cell cultivation. The change in capacity to support hematopoiesis of cord blood cells was not observed among cells with various PDLs. On the other hand, telomere length markedly decreased as PDL increased at a higher rate than that at which telomere length of primary mesenchymal stem cells decreased as the age of donor increased

Differentiation of Human Bone Marrow Mesenchymal Stem Cells to Chondrocytes for Construction of Three-dimensional Cartilage Tissue

A differentiation method of human bone marrow mesenchymal stem cells (MSCs) to chondrocytes was developed for the construction of a three-dimensional (3D) cartilage tissue. The adhesive cells, which were isolated from a human bone marrow aspirate were embedded in type I collagen in a poly-l-lactate-glycolic acid copolymer (PLGA) mesh and cultivated for 4 week together with growth factors. The degree of cellular differentiation was estimated by quantitative RT-PCR of aggrecan and type II collagen mRNAs and by staining with Safranin O. The 3D culture showed a higher degree of differentiation even without growth factors than the conventional pellet culture with growth factors, namely, dexamethasone and transforming growth factor (TGF)-β 3. The 3D culture for 2 week with the combined addition of dexamethasone, TGF-β 3, and insulin-like growth factor (IGF)-I reached a 30% expression of aggrecan mRNA compared with that in primary human chondrocytes, while the aggrecan mRNA expression in the conventional pellet culture was less than 2%. The sequential two-step differentiation cultivation, during which the cells were cultivated in 3D for 1 week after the conventional two-dimensional (2D) culture for 1 week, could markedly accelerate the expression of aggrecan mRNA compared with the 3D cultivation for 2 week

Lactams. IX. Generation of Lactam Carbonyl Function in 1,3-Disubstituted Piperidines by Mercuric Acetate-EDTA Oxidation : Effects of Hydrocarbon Substituents at the 3-Position

The mercuric acetate-(ethylenedinitrilo) tetraacetic acid oxidation of 1-(3,4-dimethoxyphenyl)-2-(3-substituted piperidino) ethanols (7c-f), which carry the n-butyl, isopropyl, benzyl, and phenyl group as the 3-substituent in the piperidine ring, has been found to produce the corresponding 2- (8c-f) and 6-piperidones (12c-f) in good yields in ratios of 41 : 59,29 : 71,26 : 74,and 15 : 85. It is suggested that the 3-substituents exert both steric and electronic effects. The structures of the lactam alcohols (8c-f, 12c-f) have been confirmed by the chemical correlation with the known pyridones (11c-f, 15c-f) through the lactams (10c-f, 14c-f). The starting piperidinoethanols (7c-f) have been synthesized from the 3-substituted pyridines (5c-f) by quaternization with 3,4-dimethoxyphenacyl bromide followed by catalytic and sodium borohydride reductions

Multiple hepatic sclerosing hemangioma mimicking metastatic liver tumor successfully treated by laparoscopic surgery: Report of a case

AbstractIntroductionHepatic sclerosing hemangioma is a very rare benign tumor, characterized by fibrosis and hyalinization occurring in association with degeneration of a hepatic cavernous hemangioma. We report here a rare case of multiple hepatic sclerosing hemangioma mimicking metastatic liver tumor that was successfully treated using laparoscopic surgery.Presentation of caseA 67-year-old woman with multiple liver tumors underwent single-incision laparoscopic sigmoidectomy under a diagnosis of advanced sigmoid cancer with multiple liver metastases. Examination of surgical specimens of sigmoid colon revealed moderately differentiated adenocarcinoma invading the serosa, and no lymph node metastases. Serum levels of carcinoembryonic antigen and carbohydrate antigen 19-9 remained within normal limits throughout the course. Two months after sigmoidectomy, the patient underwent laparoscopic partial hepatectomy of S1 and S6 of the liver and cholecystectomy. Histopathological examination showed that the tumors mainly comprised hyalinized tissue and collagen fibers with sporadic vascular spaces on hematoxylin and eosin-stained sections, yielding a diagnosis of multiple hepatic sclerosing hemangioma. No evidence of recurrence has been seen as of 21 months postoperatively.DiscussionDifferentiating multiple sclerosing hemangiomas from metastatic liver tumors was quite difficult because the radiological findings were closely compatible with liver metastases. Laroscopic hepatectomy provided less blood loss, a shorter duration of hospitalization, and good cosmetic results.ConclusionSclerosing hemangioma should be included among the differential diagnoses of multiple liver tumors in patients with colorectal cancer. Laparoscopic hepatectomy is useful for diagnostic therapy for undiagnosed multiple liver tumors

Synthesis of 3-tert-Butylpyridine

3-tert-Butylpyridine (11) has been synthesized from neopentyl alcohol in 16% overall yield through a five-step sequence. Among the steps involved are the cycloaddition of α-tert-butylacrolein (9) to butyl vinyl ether and conversion of the resulting dihydropyran derivative (10) into the pyridine base (11)