Fully automatic measuring system for assessing masticatory performance using ß-carotene-containing gummy jelly.

Despite the importance of masticatory performance in health promotion, assessment of masticatory performance has not been widely conducted to date because the methods are labour intensive. The purpose of this study is to investigate the accuracy of a novel system for automatically measuring masticatory performance that uses ß-carotene-containing gummy jelly. To investigate the influence of rinsing time on comminuted jelly pieces expectorated from the oral cavity, divided jelly pieces were treated with two types of dye solution and then rinsed for various durations. Changes in photodiode (light receiver) voltages from light emitted through a solution of dissolved ß-carotene from jelly pieces under each condition were compared with those of unstained jelly. To investigate the influence of dissolving time, changes in light receiver voltage resulting from an increase in division number were compared between three dissolving times. For all forms of divided test jelly and rinsing times, no significant differences in light receiver voltage were observed between any of the stain groups and the control group. Voltages decreased in a similar manner for all forms of divided jelly as dissolving time increased. The highest coefficient of determination (R(2)  = 0·979) between the obtained voltage and the increased surface area of each divided jelly was seen at the 10 s dissolving time. These results suggested that our fully automatic system can estimate the increased surface area of comminuted gummy jelly as a parameter of masticatory performance with high accuracy after rinsing and dissolving operations of 10 s each.

T cell activation-associated hepatic injury: mediation by tumor necrosis factors and protection by interleukin 6.

This study investigates the molecular mechanisms underlying the induction of and protection from T cell activation-associated hepatic injury. When BALB/c mice were given a single intravenous injection of concanavalin A (Con A) (> or = 0.3 mg/mouse), they developed acute hepatic injury as assessed by a striking increase in plasma transaminase levels within 24 h. Histopathologically, only the liver was injured while moderate infiltration of T cells and polymorphonuclear cells occurred in the portal areas and around the central veins. The induction of hepatic injury was dependent on the existence as well as the activation of T cells, as untreated BALB/c nu/nu mice or BALB/c mice pretreated with a T cell-specific immunosuppressive drug, FK506, failed to develop disease. Significant increases in the levels of various cytokines in the plasma were detected before an increase in plasma transaminase levels. Within 1 h after Con A injection, tumor necrosis factor (TNF) levels peaked, this being followed by production of two other inflammatory cytokines, interleukin 6 (IL-6) and IL-1. Passive immunization with anti-TNF but not with anti-IL-1 or anti-IL-6 antibody, conferred significant levels of protection. Moreover, administration of rIL-6 before Con A injection resulted in an IL-6 dose-dependent protection. A single administration of a given dose of rIL-6 completely inhibited the release of transaminases, whereas the same regimen induced only 40-50% inhibition of TNF production. More than 80% inhibition of TNF production required four consecutive rIL-6 injections. These results indicate that: (a) TNFs are critical cytokines for inducing T cell activation-associated (Con A-induced) hepatitis; (b) the induction of hepatitis is almost completely controlled by rIL-6; and (c) rIL-6 exerts its protective effect through multiple mechanisms including the reduction of TNF production.

Gene structural analysis and expression of human renal dipeptidase.

Human renal dipeptidase cDNA and genomic DNA were isolated from human kidney cDNA and genomic libraries, respectively. The human renal dipeptidase gene has a total length of approximately 6 kb and consists of ten exons and nine introns. The exons and cDNA each encode the 411 amino acid residues of the precursor protein, including 16 amino acid residues of signal sequence and a hydrophobic carboxyl terminal sequence for the attachment of a phosphatidylinositol glycan. Although the cDNA was slightly different from the cDNA reported by Adachi et al. (1990), the differences observed suggest, by comparison with human genomic DNA, that it may not represent an allelic variant but a cloning artifact. The recombinant human renal dipeptidase was produced on the surface of transfected L929 cells and had the same character as native renal dipeptidase. Northern blotting hybridization analysis showed that renal dipeptidase mRNA is only transcribed in kidney.

Cloning and structural analysis of genomic DNA for human renal dipeptidase.

A genomic DNA for human renal dipeptidase was isolated from a human genomic library using probes for human renal dipeptidase cDNA. The human renal dipeptidase gene, containing ten exons and nine introns, had a total length of approx. 6 kbp. The DNA sequence of these exons was slightly different from that of the human renal dipeptidase cDNA reported by Adachi et al. [1]. From the results of a comparison of the deduced amino acid sequence of each exon with various mammalian renal dipeptidases, the fourth exon was found to be highly conserved (90%).

Structure of genomic DNA for rat platelet phospholipase A2.

A genomic DNA for rat platelet phospholipase A2 was isolated by screening a rat genomic library with oligonucleotide probes based on its published amino acid sequence. The rat platelet phospholipase A2 gene had a total length of about 2.5 kb and contained five exons and four introns. The intron-exon structure of the rate gene was similar to that of human non-pancreatic phospholipase A2.

Application of Namalva interferon-alpha monoclonal antibodies for purification and enzyme immunoassay of interferon-alpha.

Namalva (or Namalwa) interferon (IFN)-alpha was partially purified using a combination of conventional methods and modified acid-ethanol extraction. Four mouse monoclonal antibodies against Namalva IFN-alpha were prepared by hybridoma technology after immunization with Namalva IFN-alpha thus purified. Three of these monoclonal antibodies recognized the same or a similar epitope on Namalva IFN-alpha. One of these antibodies was paired with the fourth recognizing a different epitope and used respectively as enzyme-conjugated antibody and solid-phase antibody in our one step enzyme immunoassay (EIA) for IFN-alpha. This assay is simple and was able to detect as little as 5 pg of IFN-alpha in 100 microliters of sample in the short time of 5 hr. There was a good correlation between the EIA and bioassay. The use of one of the monoclonal antibodies as an immunoadsorbant to purify Namalva IFN-alpha is also described.