Oxidation of regenerated cellulose with NaClO2 catalyzed by TEMPO and NaClO under acid-neutral conditions

A new TEMPO-mediated oxidation with catalytic amounts of TEMPO and NaClO, and NaClO₂ as the primary oxidant under aqueous conditions at pH 3.5–6.8 was used to prepare water-soluble β-(1 → 4)-linked polyglucuronic acid Na salts (cellouronic acids, CUAs) with high molecular weight in good yield. When regenerated cellulose with original degree of polymerization (DP) of 680 was oxidized by the 4-acetamide-TEMPO/NaClO/NaClO₂ system at pH 5.8 and 40 °C for 3 days, CUA with weight average DP (DPw) of 490 was obtained quantitatively. No peaks other than six signals from β-(1 → 4)-linked anhydroglucuronic acid units of CUA were detected in the solution-state ¹³C NMR spectra of the oxidized products. Although the oxidized product prepared under the above conditions contained about 20% unoxidized cellulose particles, the non-CUA fraction was separable from CUAs by filtration or salt precipitation. The DPw values and yields of CUAs after the filtration or salt precipitation treatment were 250–380 and 45–71%, respectively.     

Osteoprotegerin reduces the serum level of receptor activator of NF-kappaB ligand derived from osteoblasts

Osteoprotegerin (OPG) is a decoy receptor for receptor activator of NF-kappaB ligand (RANKL). We previously reported that OPG deficiency elevated the circulating level of RANKL in mice. Using OPG(-/-) mice, we investigated whether OPG is involved in the shedding of RANKL by cells expressing RANKL. Osteoblasts and activated T cells in culture released a large amount of RANKL in the absence of OPG. OPG or a soluble form of receptor activator of NF-kappaB (the receptor of RANKL) suppressed the release of RANKL from those cells. OPG- and T cell-double-deficient mice showed an elevated serum RANKL level equivalent to that of OPG(-/-) mice, indicating that circulating RANKL is mainly derived from bone. The serum level of RANKL in OPG(-/-) mice was increased by ovariectomy or administration of 1alpha,25-dihydroxyvitamin D(3). Expression of RANKL mRNA in bone, but not thymus or spleen, was increased in wild-type and OPG(-/-) mice by 1alpha,25-dihydroxyvitamin D(3). These results suggest that OPG suppresses the shedding of RANKL from osteoblasts and that the serum RANKL in OPG(-/-) mice exactly reflects the state of bone resorption.     

Inhibition of lipase activities by basic polysaccharide

Basic polysaccharide strongly inhibited the hydrolysis of trioleoylglycerol (TO) emulsified with phosphatidylcholine and taurocholate by either pancreatic lipase or carboxylester lipase. DEAE-Sephadex dose-dependently inhibited the hydrolysis of TO by pancreatic lipase and carboxylester lipase; however, carboxymethyl-Sephadex and Sephadex G-50 did not inhibit the hydrolysis. Polydextrose (PD), a soluble polysaccharide, was a very weak inhibitor of pancreatic lipase. However, when a basic group, a DEAE group, was attached to PD, lipase inhibition by DEAE-PD was increased, and this was dependent on the substitution ratio of DEAE groups. The number of positive charges per PD molecule is important in lipase inhibition. Similar substitution effects were observed with other basic groups, such as piperidinoethyl and 3-triethylamino-2-hydroxypropyl. The natural basic polysaccharide, chitosan, also inhibited pancreatic lipase activity. Gel-filtration experiments suggested that DEAE-PD did not bind strongly to pancreatic lipase. The effect of DEAE-PD on TO hydrolysis by pancreatic lipase was studied using various emulsifiers: DEAE-PD (50 microg/ml) did not inhibit the hydrolysis of TO emulsified with arabic gum, phosphatidylserine, or phosphatidic acid. In vivo, oral administration of DEAE-PD to rats reduced the peak plasma triacylglycerol concentration and increased fecal lipid excretion. These results suggest that basic polysaccharide is able to suppress dietary fat absorption from the small intestine by inhibiting pancreatic lipase activity.     

The crystal structure of a virus-like particle from the hyperthermophilic archaeon Pyrococcus furiosus provides insight into the evolution of viruses

Pyrococcus furiosus is a hyperthermophilic archaeal microorganism found near deep-sea thermal vents and its optimal growth temperature of 100 degrees C. Recently, a 38.8-kDa protein from P. furiosus DSM 3638 was isolated and characterized. Electron microscopy revealed that this protein aggregated as spheres of approximately 30 nm in diameter, which we designated P. furiosus virus-like particles (PfVs). X-ray crystallographic analysis at 3.6-A resolution revealed that each PfV consisted of 180 copies of the 38.8-kDa protein and retained T=3 icosahedral symmetry, as is often the case in spherical viruses. The total molecular mass of each particle was approximately 7 MDa. An examination of capsid structures suggested strong evolutionary links among PfV, tailed double-stranded DNA bacteriophages, and herpes viruses. The similar three-dimensional structures of the various coat proteins indicate that these viral capsids might have originated and evolved from a common ancestor. The structure of PfV provides a previously undescribed example of viral relationships across the three domains of life (Eukarya, Bacteria, and Archaea).     

Kinematic quantitation of the patellar tendon reflex using a tri-axial accelerometer

We designed a simple procedure based on the angular speed of the knee joint for quantitating the patellar tendon reflex. The angular speed of the knee joint is calculated from acceleration data generated in response to the tapping force applied to the patellar tendon with a customized tendon hammer and measured using a tri-axial accelerometer placed at the ankle joint. Data were collected and processed using a signal analyzer and a notebook PC. The results obtained using standard equipment were similar to those generated by more elaborate devices. For instance, the time delay (29.6+/-6.0 ms) and the acceleration time (150.8+/-19.5 ms) of the speed response were quite constant for all participants within the range of tapping forces normally applied during physical examinations. Representative relationships between the peak tapping force and the peak angular speed also closely fit with the exponential model (the average coefficient of determination, 0.70; range, 0.43-0.97). In contrast, the mean asymptotic value of the peak angular speed (Omega(pas)) was 160+/-67 degrees/s for spastic individuals, compared with only 72+/-21 degrees/s for healthy individuals. The important features of this method are portability, ease of use, and non-constraint of solicited reflex responses.     

A novel approach for myocardial regeneration with educated cord blood cells cocultured with cells from brown adipose tissue

Umbilical cord blood (CB) is a promising source for regeneration therapy in humans. Recently, it was shown that CB was a source of mesenchymal stem cells as well as hematopoietic stem cells, and further that the mesenchymal stem cells could differentiate into a number of cells types of mesenchymal lineage, such as cardiomyocytes (CMs), osteocytes, chondrocytes, and fat cells. Previously, we reported that brown adipose tissue derived cells (BATDCs) differentiated into CMs and these CMs could adapt functionally to repair regions of myocardial infarction. In this study, we examined whether CB mononuclear cells (CBMNCs) could effectively differentiate into CMs by coculturing them with BATDCs and determined which population among CBMNCs differentiated into CMs. The results show that BATDCs effectively induced CBMNCs that were non-hematopoietic stem cells (HSCs) (educated CB cells: e-CBCs) into CMs in vitro. E-CBCs reconstituted infarcted myocardium more effectively than non-educated CBMNCs or CD34-positive HSCs. Moreover, we found that e-CBCs after 3 days coculturing with BATDCs induced the most effective regeneration for impaired CMs. This suggests that e-CBCs have a high potential to differentiate into CMs and that adequate timing of transplantation supports a high efficiency for CM regeneration. This strategy might be a promising therapy for human cardiac disease.     

Antibiotic effect of amoxicillin on the feces composting process and reactivation of bacteria by intermittent feeding of feces

The aim of this work was to investigate the single exposure effect of amoxicillin on the feces composting process and the possibility of its bacterial reactivation by intermittent feeding of feces. The respiratory activity of the bacteria during the process after receiving exposure to several dosages of amoxicillin indicated a decrement of treatment performance, which was caused by the reduction of the initial viable bacterial count and activity brought about by the amoxicillin dosage. The amount of remaining feces was proportional to the initial concentration of amoxicillin, and even though no amoxicillin was detected, no automatic reactivation was observed, either. An intermittent feces feeding test was conducted to reactivate the bacteria. For the 10 and 100microg-amoxicillin/g dry systems, reactivation was observed, but for the 1000microg/g dry, no reactivation was seen. Finally, an intermittent feces feeding test was conducted with sterilized sawdust and the result indicated that the feces acted as a substrate rather than as a bacterial carrier.     

Atf1 is a target of the mitogen-activated protein kinase Pmk1 and regulates cell integrity in fission yeast

In fission yeast, knockout of the calcineurin gene resulted in hypersensitivity to Cl(-), and the overexpression of pmp1(+) encoding a dual-specificity phosphatase for Pmk1 mitogen-activated protein kinase (MAPK) or the knockout of the components of the Pmk1 pathway complemented the Cl(-) hypersensitivity of calcineurin deletion. Here, we showed that the overexpression of ptc1(+) and ptc3(+), both encoding type 2C protein phosphatase (PP2C), previously known to inactivate the Wis1-Spc1-Atf1 stress-activated MAPK signaling pathway, suppressed the Cl(-) hypersensitivity of calcineurin deletion. We also demonstrated that the mRNA levels of these two PP2Cs and pyp2(+), another negative regulator of Spc1, are dependent on Pmk1. Notably, the deletion of Atf1, but not that of Spc1, displayed hypersensitivity to the cell wall-damaging agents and also suppressed the Cl(-) hypersensitivity of calcineurin deletion, both of which are characteristic phenotypes shared by the mutation of the components of the Pmk1 MAPK pathway. Moreover, micafungin treatment induced Pmk1 hyperactivation that resulted in Atf1 hyperphosphorylation. Together, our results suggest that PP2C is involved in a negative feedback loop of the Pmk1 signaling, and results also demonstrate that Atf1 is a key component of the cell integrity signaling downstream of Pmk1 MAPK.