In vivo determination of tooth mobility after fixed orthodontic appliance therapy with a novel intraoral measurement device.

OBJECTIVE: Valid measurement systems recording tooth mobility upon displacement within the subtle range of physiological strains are missing. Here, we introduce a novel in vivo measurement device and demonstrate a first clinical application by monitoring tooth mobility changes during retention after fixed multibracket appliance therapy. MATERIALS AND METHODS: Tooth mobility was measured in vivo on 21 patients (11 female, 10 male; mean age 16.1 ± 3.1 years) by displacing the upper first incisor 0.2 mm lingually for 0.2, 0.5, 1, 2, 5, and 10 s with the novel intraoral device. Measurements were recorded directly after, as much as 2, 7, and 14 days and up to 6 months after appliance debonding. RESULTS: Device performance was precise and valid in clinical use. Data revealed significant interindividual varying tooth mobility, which was very high during the first 2 days after appliance removal. After 1 week, mobility values decreased, but were generally higher upon short loadings compared to long ones. After 3 months, tooth mobility was significantly lower than directly after debonding. Interestingly, males exhibited significantly less mobility than females. CONCLUSIONS: Our work is the first using an in vivo measurement device capable of performing and recording tooth displacements within this delicate range and in such precision. Furthermore, our findings elucidate tooth mobility changes after multibracket treatment, giving important information for retention periods. CLINICAL RELEVANCE: Establishment of this novel measurement device in clinical use is an important improvement when approaching the complexity of tooth mobility in vivo regarding different issues like orthodontics, periodontal disease, or bruxism.

Biochemical characteristics of trypsin inhibitor from wheat grain, beta variety.

A homogenous trypsin inhibitor from wheat grain has been characterized. It is a protein of molecular weight 9105 Da and isoelectric point pI = 9.5. It belongs to arginine type inhibitors. The isolated inhibitor does neither inhibit native proteinases from wheat grain nor alpha-chymotrypsin, papein and pepsin. However, it inhibits some proteinases from microorganisms and moulds. It is susceptible to the action of hydrogen peroxide. The inhibitory protein consists of all amino acid residues with the largest amount of glutamic acid, proline and arginine, and the lowest of histidine and tyrosine, respectively.

The varietal differences in some biological activities of proteins extracted from flours of wheat seeds harvested in 1986.

Six wheat seeds varieties taken for experiments showed some differences in crude protein content ranging from 10.4-12.8%. A procedure for protein fractionation by the successive elimination of albumins, globulins and gliadins from the wheat varieties studied was elaborated. In the obtained protein fractions endogenous amylolytic and inhibitory activities tested against bovine pancreas trypsin and alpha-amylases of mammalian and insect origin were determined. The determined biological activities differ considerable among wheat varieties studied and were mainly located in albumins and gliadins while only a small amount were detected in globulins. Extractable proteins were relatively thermostabile and powerful inhibitors of the alpha-amylases examined. As the influence of environmental conditions was the same for all wheat varieties studied the observed differences in biological activities should be rather attributed to the genetic differences.

Single cell protein as food and feed.

This review pertains the current knowledge concerned with the application of SCP in human and animal nutrition. General factors limiting the utilization of microbial proteins in human nutrition, such as toxicological barriers, nutritive value and functional properties, are discussed. Special attention is paid to several modern procedures of protein extraction from microbial cells, reduction of nucleic acids level as well as preparation of protein isolates. According to the data presented the latter can be considered as valuable protein substitutes. Significantly less nutritive problems are being concerned with the application of SCP in animal nutrition. Successful feeding experiments with chicken and pigs are discussed. Under these experimental conditions 10-20% of the protein in the feedstuff can be replaced by SCP. Moreover, several in Poland obtained protein-vitamin preparations are described. These originated from selected yeast and propionic acid bacteria grown in whey and its ultrafiltrates and can be considered as valuable food and feed supplements.

Some biochemical properties of trypsin inhibitor type antinutrients derived from extracts of wheat grain, Beta variety.

Trypsin inhibitors were isolated and partially purified from wheat grain, Beta variety. The procedure for determination of the inhibitory activity was simplified. This pertains shortening of the reaction time as well as quantitative decrease of components in the incubation mixture. The inhibitory fraction was salted out at 30-65% ammonium sulfate saturation. The experimental material has not been initially defatted. For isolation of the inhibitors pH 4.4 was demonstrated to be optimal. The trypsin inhibitor was characterized by relatively low activity against trypsin (1.5% of soya inhibitory activity). Preparations showing inhibitory properties when stored at -18 degrees C retained their original activity for 40 days, whereas at 4 degrees C only for 10 days, respectively. Storage at 18 degrees C for 10 days resulted in 50% loss of the original activity. Among various factors stabilizing the inhibitory activity being studied, 2-mercaptoethanol at 0.01% final concentration was found to be most effective. Study on the effect of temperature on the antitrypsin activity revealed that the preparation retained its initial activity up to 80 degrees C. It has been demonstrated by wheat proteins fractionation that both albumin and globulin fractions were accompanied by the antitrypsin activity. Moreover gluten was also shown to exhibit some inhibitory activity. Variations in the inhibitory activity were evidenced during germination of wheat grain. After 2 days period of germination it tended to decrease, disappearing completely at the fifth day, respectively. The inhibitory activity appeared in coleoptile and root at fourth day of germination, being higher in coleoptile than in the roots.

Plant inhibitors of proteolytic enzymes.

The presence of inhibitors of proteinases was stated in many species of plants. There are macropeptides of the molecular weight ranging from 3700 to 8000, often bound to carbohydrates. Potential sources of inhibitors of proteinases are legumes, cereals, potatoes and also some fruits. They are characterized by different activity. "Single-headed" inhibitors inhibit one type of proteolytic enzyme, when "double-headed" inhibitors, possessing two independent active sites, can inhibit several types of proteolytic enzymes at the same time. They also differ in the resistance to temperature and change of pH. The role and importance of inhibitors of proteinases is not exactly explained. They are used in the pharmaceutical, baking and beer-industry as well as in the therapy of numerous diseases.

Critical evaluation of the current studies on pangamic acid--vitamin B15.

The research on pangamic acid (vitamin B15) has been conducted by specialists in many fields of science for along time. This, however, has not put an end to controversies around the problem of its therapeutic effect. The solution to the basic problems, i.e. defining the compound structure, finding an explicit method of its determination and identification as well as the evidence of its biochemical and physiological functions in the human organism appears as distant as ever. It has been found out, however, that either some preparations referred to as pangamic acid (vitamin B15) or their components may be detrimental to man's health.

Some problems concerning the determination of different corrinoids by the plate method with Escherichia coli 113-3.

Biological activity of some vitamin B12 forms for Escherichia coli 113-3 and the effect of methionine on the assay of these compounds by E. coli 113-3 were studied. It was found that the coenzymatic form had the highest biological activity and that under experimental conditions methionine was an interfering factor in determination of the coenzymatic form and the methyl derivative of B12 only. Otherwise, metionine did not affect the determination of cyanocobalamin an hydroxycobalamin even when the methionine and vitamin B12 ratio was 32 000 : 1.