Moisture Sorption Isotherms of Various Tobaccos

The equilibrium moisture contents of sun-cured (Kroumougrad), flue-cured (Bright Yellow—4) and air-cured (Burley-21 and Matsukawa) tobaccos were measured over a relative humidity range from 5 to 80% at 20°C. The moisture sorption isotherms of tobaccos were of sigmoid type, and classified into two groups. In a lower humidity range below ca. 40% RH, the A group (Kroumougrad and BY-4) had a smaller moisture sorption capacity than B group (Burley-21 and Matsukawa), while in a higher humidity range above ca. 50% RH the former had a larger moisture sorption capacity than the latter. By extracting with water, the moisture content of BY-4 was increased in the lower humidity range, while it decreased in the higher humidity range. However, the moisture content of Matsukawa was scarecely changed by extracting it with water. These results suggest that the differences in equilibrium moisture content with the type of curing were due to the differences in contents of water soluble com- ponents. To control the hygroscopic properties of a tobacco, therefore, the influences of the addition of sucrose and glycerol on the equilibrium moisture content were quantitatively analysed. The moisture sorption capacity of tobacco was greatly different from its nitrogen sorption capacity. The specific surface area of tobacco calculated from moisture sorption isotherm was ca. 110 times larger than the specific surface area calculated from the nitrogen sorption isotherm. Both the nitrogen and moisture sorption data should be necessary for better understanding of the complicated sorption-desorption phenomena in tobaccos.     

B7-H3 contributes to the development of pathogenic Th2 cells in a murine model of asthma

B7-H3 is a new member of the B7 family. The receptor for B7-H3 has not been identified, but it seems to be expressed on activated T cells. Initial studies have shown that B7-H3 provides a stimulatory signal to T cells. However, recent studies suggest a negative regulatory role for B7-H3 in T cell responses. Thus, the immunological function of B7-H3 is controversial and unclear. In this study, we investigated the effects of neutralizing anti-B7-H3 mAb in a mouse model of allergic asthma to determine whether B7-H3 contributes to the development of pathogenic Th2 cells and pulmonary inflammation. Administration of anti-B7-H3 mAb significantly reduced airway hyperreactivity with a concomitant decrease in eosinophils in the lung as compared with control IgG-treated mice. Treatment with anti-B7-H3 mAb also resulted in decreased production of Th2 cytokines (IL-4, IL-5, and IL-13) in the draining lymph node cells. Although blockade of B7-H3 during the induction phase abrogated the development of asthmatic responses, B7-H3 blockade during the effector phase did not inhibit asthmatic responses. These results indicated an important role for B7-H3 in the development of pathogenic Th2 cells during the induction phase in a murine model of asthma.     

Phase Changes in Amylose–Butanol Complex Solution

The phase change for an amylose–butanol complex solution in 10% of dimethylsulfoxide was investigated as a function of temperature. The phase change was determined with measurements of the turbidity, fluorescent depolarization, and viscosity. The phase diagram obtained was qualitatively similar to that for an amylose solution. From the result, the change in solution phase for the amylose–butanol complex is suggested to be similar to that for amylose, i.e., when the solution cools from a higher temperature, amylose molecules in the complex solution change the conformation from a random coil to an interrupted helix, and then separate into two phases. Coacervate particles resulting from the phase separation coalesce with each other to yield precipitates.

An adsorption of uranine on amylose was studied to ascertain its relationship with the fluorescent depolarization method used for detecting phase changes in solution. The result showed that uranine was adsorbed on amylose chains but not on the amylose–butanol complex.     

Rapid detection of natural cells of Alexandrium tamarense and A. catenella (Dinophyceae) by fluorescence in situ hybridization

The marine toxic dinoflagellates Alexandrium tamarense (Lebor) Balech and A. catenella (Whedon and Kofoid) Taylor that cause paralytic shellfish poisoning (PSP) are identified on the basis of morphological features in routine monitoring. Rapid and simple identification is, however, often difficult because of the morphological similarity. Fluorescent in situ hybridization (FISH) using ribosomal RNA (rRNA)-targeted probes has been studied as a method of easily identifying and enumerating species responsible for harmful algal blooms (HABs). Its application to monitoring natural populations of HAB species, however, is limited. Here, we applied the FISH method to identify and enumerate cells of A. tamarense and A. catenella in natural plankton assemblages collected from Japanese coastal waters. A. tamarense-specific (Atm1) and A. catenella-specific (Act1) probes were established based on the D2 region of the large-subunit ribosomal RNA gene (28S rDNA). With these two probes, natural cells of A. tamarense or A. catenella in field samples could easily be identified when the following three conditions were met. First, cells should be concentrated by filtration, not centrifugation, in order to avoid the loss of cells. Second, autofluorescence should be minimized; acetone was an effective decolorization reagent. Third, samples should be stored at −20 or −80 °C for long-term preservation. The results indicate that FISH is a useful tool for the rapid identification of toxic Alexandrium spp. and can facilitate the analysis of numerous natural samples.     

Purification and properties of extracellularβ-fructofuranosidases fromAureobasidium sp. ATCC 20524

Summary Two extracellular -fructofuranosidases (E-1 andE-2) fromAureobasidium sp. ATCC 20524, producing 1-kestose (1^F--fructofuranosyl-sucrose) from sucrose, were purified to homogeneity. Molecular weights of the enzymes were estimated to be about 304000 (E-1) and 315000 (E-2) Da by gel filtration. The enzymes contained 33% (w/w) (E-1) and 27% (w/w) (E-2) carbohydrate. TheK _m values for sucrose ofE-1 andE-2 andE-2 were 0.34 and 0.28 M, respectively. were 0.34 and 0.28 M, respectively. The enzymatic profiles of these enzymes were almost identical to intracellular enzymesP-1 andP-2 except for the differences in carbohydrate content andK _m values ofE-2 andP-2.     

Discovery of novel prostaglandin analogs as potent and selective EP2/EP4 dual agonists

To identify potent EP2/EP4 dual agonists with excellent subtype selectivity, a series of γ-lactam prostaglandin E analogs bearing a 16-phenyl ω-chain were synthesized and evaluated. Structural hybridization of 1 and 2, followed by more detailed chemical modification of the benzoic acid moiety, led us to the discovery of a 2-mercaptothiazole-4-carboxylic acid analog 3 as the optimal compound in the series. An isomer of this compound, the 2-mercaptothiazole-5-carboxylic acid analog 13, showed 34-fold and 13-fold less potent EP2 and EP4 receptor affinities, respectively. Structure activity relationship data from an in vitro mouse receptor binding assay are presented. Continued evaluation in an in vivo rat model of another 2-mercaptothiazole-4-carboxylic acid analog 17, optimized for sustained compound release from PLGA microspheres, demonstrated its effectiveness in a rat bone fracture-healing model following topical administration.     

Antiserum to Nitrogenase Generated from an Amplified DNA Fragment from Natural Populations of Trichodesmium spp

A fragment of the nifH gene was amplified from natural populations of Trichodesmium spp. and cloned into a maltose-binding protein (MBP) expression vector. The peptide product of the amplified 359-bp fragment of nifH was cleaved from the fusion protein, purified, and used to generate a specific antibody to the Fe protein of nitrogenase. The antiserum recognized the MBP-nitrogenase fusion protein and the cleaved nif peptide product but not MBP. The antibody cross-reacted with nitrogenase from natural populations of Trichodesmium spp. from the Caribbean Sea and with a cultured isolate from the Kuroshio waters (Trichodesmium sp. strain NIBB1067). The same nifH fragment was amplified, cloned, and sequenced from Trichodesmium sp. strain NIBB1067 and was found to be 98% identical at both the protein and DNA levels to nifH from the Caribbean populations. Three of the six nucleotide differences between the Trichodesmium sp. strain NIBB1067 and the Trichodesmium spp. nifH sequence had also been found in a second sequence from the natural populations, indicating either that there is more than one strain of Trichodesmium sp. in natural assemblages or that there are multiple copies of nifH in the genome. This DNA fragment, which is easily amplified with the polymerase chain reaction, may provide a good indicator of species relatedness without requiring extensive cloning or sequencing. Furthermore, the use of the polymerase chain reaction in combination with a MBP protein fusion vector provides a rapid method for production of highly specific sera, starting with a small amount of DNA.