Maillard reaction rate in various glassy matrices

The Maillard Reaction (MR) rate below the glass transition temperature (T(g)) for various model glassy food systems was studied at temperatures between 40 degrees C and 70 degrees C. As a sample, freeze-dried glucose and lysine systems embedded in various glassy matrices (e.g., polyvinylpyrrolodone and trehalose) were used, and the MR rate below the T(g) was compared among the various glassy matrices. The extent of MR was estimated spectrophotometrically from the optical density at 280 nm (OD(280)), and the MR rate (k(280)) was determined as a pseudo zero order reaction rate from the time course of OD(280). Although k(280) was described by the Arrhenius plot, the temperature dependence of k(280) was almost the same and the intercept was different among the matrices. From the comparison of k(280), it was suggested that the MR rate in glassy matrix was affected not only by the T(g), but also by the hydrogen bonding between MR reactants and glassy matrix.     

Isolation and Some Properties of Fimbriae of Oral <Emphasis Type="Italic">Streptococcus intermedius</Emphasis>

Streptococcus intermedius 1208-1 carried linear fiber-like fimbriae that extended radially from the cell surface. The fimbriae were isolated by pipetting and sonication and were purified by ammonium sulfate precipitation followed by a column chromatography series. Heat treatment in the presence of sodium dodecyl sulfate resulted in the dissociation into smaller molecules. Rabbit antiserum raised against the purified protein reacted with fimbriae on the surface of bacteria under immunogold staining. Serotype g or g-related strains produced the fimbriae and aggregated in human saliva. The aggregation was inhibited by the anti-fimbriae immunoglobulin Fab fragment or the purified fimbriae.     

Anti-AIDS agents. Part 57: Actein, an anti-HIV principle from the rhizome of Cimicifuga racemosa (black cohosh), and the anti-HIV activity of related saponins

Actein (1), a tetracyclic triterpenoid from the rhizome of Cimicifuga racemosa (black cohosh), and 82 related triterpenoid and steroidal saponins isolated from higher plants were evaluated for anti-HIV activity as a continuing study to discover potential anti-AIDS agents from natural products. Actein showed potent activity and another twelve saponins showed moderate activity. The active compounds included two steroidal, seven tetracyclic triterpenoid, and four pentacyclic triterpenoid compounds.     

Early development of the self-fertilizing mangrove killifish <Emphasis Type="Italic">Rivulus marmoratus</Emphasis> reared in the laboratory

The mangrove killifish Rivulus marmoratus was reared at 25°±1°C and 17ppt salinity from 0 to 100 days after hatching (DAH), and its early development was described by examining growth and morphometric parameters, meristic characters (vertebral and fin-ray counts), bone-cartilage development, and pigmentation. Growth was isometric for preanal length, head length, snout length, body depth, pectoral-fin length, dorsal-fin length, anal-fin length, and caudal-peduncle depth. Negative allometric growth was observed in eye diameter and gape size. Meristic counts (mean±SD) for vertebrae (34.2±0.4) and dorsal- (8.6±0.5), anal- (11.4±0.5), and caudal-fin rays (30.2±0.8) were complete at 0 DAH (n=5), whereas pectoral-fin rays and pelvic-fin rays were complete by 30 DAH (14.5±0.4, n=5) and 60 DAH (4.2±0.8, n=5). Full ossification of meristic elements proceeded in the following sequence: vertebrae (by 30 DAH), caudal-, dorsal-, and anal-fin rays (by 60 DAH), pectoral-fin rays (between 60 DAH and 100 DAH), and pelvic-fin rays (by 100 DAH). Both morphological characters and meristic counts indicate that this species can be considered to be a juvenile after 9.8mm in standard length (20 DAH).     

Physiological and subjective responses in the elderly when using floor heating and air conditioning systems

The purpose of this study was to investigate the effects of a floor heating and air conditioning system on thermal responses of the elderly. Eight elderly men and eight university students sat for 90 minutes in a chair under the following 3 conditions: air conditioning system (A), floor heating system (F) and no heating system (C). The air temperature of sitting head height for condition A was 25 degrees C, and the maximum difference in vertical air temperature was 4 degrees C. The air and floor temperature for condition F were 21 and 29 degrees C, respectively. The air temperature for condition C was 15 degrees C. There were no significant differences in rectal temperature and mean skin temperature between condition A and F. Systolic blood pressure of the elderly men in condition C significantly increased compared to those in condition A and F. No significant differences in systolic blood pressure between condition A and F were found. The percentage of subjects who felt comfortable under condition F was higher than that of those under condition A in both age groups, though the differences between condition F and A was not significant. Relationships between thermal comfort and peripheral (e.g., instep, calf, hand) skin temperature, and the relationship between thermal comfort and leg thermal sensation were significant for both age groups. However, the back and chest skin temperature and back thermal sensation for the elderly, in contrast to that for the young, was not significantly related to thermal comfort. These findings suggested that thermal responses and physiological strain using the floor heating system did not significantly differ from that using the air conditioning system, regardless of the subject age and despite the fact that the air temperature with the floor heating system was lower. An increase in BP for elderly was observed under the condition in which the air temperature was 15 degrees C, and it was suggested that it was necessary for the elderly people to heat the room somehow in winter. Moreover, it is particularly important for elderly people to avoid a decrease in peripheral skin temperature, and maintain awareness of the warmth of peripheral areas, such as the leg, in order to ensure thermal comfort.     

Isolation of New <Emphasis Type="Italic">Symbiodinium</Emphasis> Strains from Tridacnid Giant Clam (<Emphasis Type="Italic">Tridacna crocea</Emphasis>) and Sea Slug (<Emphasis Type="Italic">Pteraeolidia ianthina</Emphasis>) Using Culture Medium Containing Giant Clam Tissue Homogenate

Recent molecular biological studies have revealed that some photosymbiotic invertebrates dwelling in coral reefs host several genetically different dinoflagellates, Symbiodinium species, as symbionts. However, little is known about the difference in physiologic characteristics among these symbionts living in a single host, because some Symbiodinium strains are difficult to culture in vitro. To isolate some of these Symbiodinium strains, we have developed an agar culture medium plate containing antibiotics and a giant clam tissue homogenate. Using-this medium we isolated two new Symbiodinium strains from two molluscan hosts, Tridacna crocea and Pteraeolidia ianthina, each of which hosted two different Symbiodinium strains belonging to Symbiodinium C and D, respectively. The tissue homogenate was essential for the growth of Symbiodinium D. Although it was not essential for the growth of Symbiodinium C, it did stimulate the initial growth. For the isolation of some Symbiodinium strains, isolation medium containing host homogenate is effective.     

Effects of oral contraceptive use on body mass index and blood pressure among female villagers in north-east Thailand

The use of contraceptives has become prevalent among females in Thailand in the past 20 years, and oral contraceptive use has been suggested to trigger changes in fat intake, energy expenditure, fat metabolism and blood pressure. Based on field investigations of 391 married women aged 20 years or over in Yasothon Province, North-east Thailand, this study aims to elucidate the effects of oral contraceptive use on body mass index (BMI: kg/m2) and blood pressure, taking into account reproductive histories and socioeconomic conditions. The proportion of obese (BMI > or = 25) subjects was high in the age groups 30-39, 40-49 and 50-59, accounting for, respectively, 39.4%, 51.1% and 48.5% of these populations. The proportion of women with hypertension (90/140 mmHg) was 23.7%, 18.5% and 26.2% in the 40-49, 50-59 and 60-69 age groups. Current contraceptive practices in the studied population included sterilization by operation, oral contraception and injection. These methods accounted for 43.0%, 12.8% and 8.2% of the population, respectively. Sociodemographic factors such as reproductive history, years of education and household income were not significantly related to BMI or to blood pressure (ANOVA with age adjustment). In contrast, oral contraceptive users had significantly higher BMIs and diastolic blood pressures (p<0.01, ANOVA with age adjustment). Multiple regression analysis also revealed that oral contraceptive use was a weak but significant contributing factor to both high BMI and blood pressure when sociodemographic factors were taken into account and controlled for statistically. It can thus be concluded that the use of contraceptive pills, which contain oestrogen and progestin and are provided free of charge to Thai women, tend to increase BMI and to elevate blood pressure.     

A role of the Duffy antigen for the maintenance of plasma chemokine concentrations

We examined plasma chemokine concentrations and chemokine clearance rates in Duffy antigen knockout mice. The plasma concentrations of eotaxin and MCP-1 in Duffy antigen knockout mice were less than one-third of those in wild-type mice. When eotaxin or hMGSA was intravenously injected, the chemokine disappeared more rapidly from the plasma of Duffy antigen knockout mice than from the plasma of wild-type mice. The half-lives of hIP-10 and interferon-gamma, which do not have an affinity for the Duffy antigen, in plasma were indistinguishable between Duffy antigen knockout mice and wild-type mice. These results suggest that the Duffy antigen delays the disappearance of chemokines from the plasma, resulting in the maintenance of plasma chemokine concentrations.