Nanoparticles Containing Curcumin Useful for Suppressing Macrophages In Vivo in Mice

To explore a novel method using liposomes to suppress macrophages, we screened food constituents through cell culture assays. Curcumin was one of the strongest compounds exhibiting suppressive effects on macrophages. We subsequently tried various methods to prepare liposomal curcumin, and eventually succeeded in preparing liposomes with sufficient amounts of curcumin to suppress macrophages by incorporating a complex of curcumin and bovine serum albumin. The diameter of the resultant nanoparticles, the liposomes containing curcumin, ranged from 60 to 100 nm. Flow cytometric analyses revealed that after intraperitoneal administration of the liposomes containing curcumin into mice, these were incorporated mainly by macrophages positive for F4/80, CD36, and CD11b antigens. Peritoneal cells prepared from mice injected in vivo with the liposomes containing curcumin apparently decreased interleukin-6-producing activities. Major changes in body weight and survival rates in the mice were not observed after administrating the liposomes containing curcumin. These results indicate that the liposomes containing curcumin are safe and useful for the selective suppression of macrophages in vivo in mice.     

Fluorescence digital image analysis of serotonin-induced calcium oscillations in single blood platelets

The intracellular concentration of Ca2+ [( Ca2+]i) was monitored continuously in single rabbit blood platelets by digital imaging microscopy in conjunction with Fura-2, a specific Ca(2+)-indicator dye. Ionomycin as well as aluminium fluoride caused sustained increase in [Ca2+]i in the platelet, but oscillations of [Ca2+]i were not observed. Serotonin (5-HT) induced oscillatory increases in [Ca2+]i in the presence of 1 mM CaCl2; these had not been detectable in cell populations because the oscillations were not in synchrony. This effect of 5-HT was diminished when CaCl2 was omitted from the medium, and was antagonized by 1 microM ketanserin, a specific 5-HT2 receptor antagonist. Furthermore, DOI, a specific 5-HT2 agonist, had the same effect as 5-HT at lower concentration. A specific effector mechanism, not fully understood at present, therefore appears to mediate 5-HT2 receptors thereby allowing rabbit platelets to generate [Ca2+]i oscillations. It is suggested that protein kinase C in platelets might play a key role in the regulation of [Ca2+]i, and possibly in [Ca2+]i oscillations.     

Production of 10-ketostearic acid from oleic acid by a strain of Flavobacterium sp. 12-4A

Summary A new Flavobacterium sp., strain 12-4A, produces solely 10-ketostearic acid (KSA) from oleic acid (OA) in growing cultures. Under optimized conditions 14 mg/ml of KSA was produced from 25 mg/ml of OA after 3 days of cultivation at 30°C.     

Production of vitamin B12 in an upflow anaerobic filter continuous reactor using Acetobacterium sp.

The accumulation of biofilm by Acetobacterium sp. during continuous culture in an upflow anaerobic filter (UAF) growing on methanol-formate was the result of space velocity and inlet concentrations of substrate and Co⁺². To achieve good development of biofilm, a space velocity of 0.38 h^–1, inlet substrate concentrations of 125 mM of both methanol and formate, and Co⁺² at 0.16 mM were required. Cell productivities in the effluent of the UAF-reactor were about 6-fold higher than in chemostat cultures (0.20 g l^–1 h^–1 for UAF and 0.035 g l^–1 h^–1 for chemostat) (previous studies), and the maximum vitamin B₁₂ specific concentration was 5.1 mg g cell^–1.     

Crystal structure determinations of oxidized and reduced pseudoazurins from Achromobacter cycloclastes. Concerted movement of copper site in redox forms with the rearrangement of hydrogen bond at a remote histidine.

The crystal structures of oxidized and reduced pseudoazurins from a denitrifying bacterium, Achromobacter cycloclastes IAM1013, have been determined at 1.35- and 1.6-A resolutions, respectively. The copper site in the oxidized state exhibits a distorted tetrahedral structure like those of other pseudoazurins. However, not only a small change of the copper geometry, but concerted peptide bond flips are identified. The imidazole ring of remote His6 has a hydrogen bonding distance of 2.73 A between N-delta1(His6) and O-gamma1(Thr36) in the oxidized protein. When the protein is reduced at pH 6.0, the imidazole ring rotates by 30.3 degrees and moves 1.00 A away from the position of the oxidized state. A new hydrogen bond between N-epsilon2(His6) and O-epsilon1(Glu4) is formed with a distance of 3.03 A, while the hydrogen bond between N-delta1(His6)-O-gamma1(Thr36) is maintained with an interatomic distance of 2.81 A. A concomitant peptide bond flip of main chain between Ile34 and Thr36 occurs.     

Transgenic Expression of the Formin Protein Fhod3 Selectively in the Embryonic Heart: Role of Actin-Binding Activity of Fhod3 and Its Sarcomeric Localization during Myofibrillogenesis

Fhod3 is a cardiac member of the formin family proteins that play pivotal roles in actin filament assembly in various cellular contexts. The targeted deletion of mouse Fhod3 gene leads to defects in cardiogenesis, particularly during myofibrillogenesis, followed by lethality at embryonic day (E) 11.5. However, it remains largely unknown how Fhod3 functions during myofibrillogenesis. In this study, to assess the mechanism whereby Fhod3 regulates myofibrillogenesis during embryonic cardiogenesis, we generated transgenic mice expressing Fhod3 selectively in embryonic cardiomyocytes under the control of the β-myosin heavy chain (MHC) promoter. Mice expressing wild-type Fhod3 in embryonic cardiomyocytes survive to adulthood and are fertile, whereas those expressing Fhod3 (I1127A) defective in binding to actin die by E11.5 with cardiac defects. This cardiac phenotype of the Fhod3 mutant embryos is almost identical to that observed in Fhod3 null embryos, suggesting that the actin-binding activity of Fhod3 is crucial for embryonic cardiogenesis. On the other hand, the β-MHC promoter-driven expression of wild-type Fhod3 sufficiently rescues cardiac defects of Fhod3-null embryos, indicating that the Fhod3 protein expressed in a transgenic manner can function properly to achieve myofibril maturation in embryonic cardiomyocytes. Using the transgenic mice, we further examined detailed localization of Fhod3 during myofibrillogenesis in situ and found that Fhod3 localizes to the specific central region of nascent sarcomeres prior to massive rearrangement of actin filaments and remains there throughout myofibrillogenesis. Taken together, the present findings suggest that, during embryonic cardiogenesis, Fhod3 functions as the essential reorganizer of actin filaments at the central region of maturating sarcomeres via the actin-binding activity of the FH2 domain.     

Genetic Recombination in Klebsiella pneumoniae An Approach to Genetic Linkage Mapping

Genetic recombination was observed between two different strains of Klebsiella pneumoniae, which is a non-motile and encapsulated bacterium belonging to the family Enterobacteriaceae and has about 55% of its DNA content as GC. The mode of recombination seemed to be similar to that of the F-factor mediated conjugation in Escherichia coli. One strain acted as the donor and the other as the recipient, and a relatively large fragment of the donor's chromosome was transferred unilaterally and unidirectionally by cell to cell contact. No genetic factor which is associated with the recombination has been identified. The genetic linkage map of K. pneumoniae was analyzed various mutants derived from the two strains. It was found that the 28 markers so far investigated were arranged linearly in a single linkage group, and that the genetic linkage map of K. pneumoniae, like that of E. coli, could be considered circular. The proposed genetic linkage map of K. pneumoniae was quite similar to that of E. coli or Salmonella typhimurium. The close similarities in this map among the three species suggest a possibility that K. pneumoniae may have differentiated from an ancestor common all three species.