The alkaline phosphatase from bone: transphosphorylating activity and kinetic mechanism.

For the purified alkaline phosphatase from bone, the ability to catalyze a phosphate transfer reaction from p-nitrophenyl phosphate to two different hydroxy acceptor compounds, ethanolamine and glycerol, was established by identification of the formed phosphorylated products, phosphoethanolamine and glycerol 3-phosphate, respectively. In addition, a steady-state kinetic analysis of the hydrolysis of p-nitrophenyl phosphate in the presence of an added nucleophile, diethanolamine, gave rise to the proposal of a simple model for the kinetic mechanism of the enzyme. This mechanism includes a covalent phosphoryl enzyme intermediate, the dephosphorylation of which by water (k3) or a nucleophile (k4) is rate-determining. According to this model, in the presence of diethanolamine, k3 and k4 were determined to be 4.44 s-1 M-1 and 1000 s-1 M-1, respectively. Therefore, in vitro a suitable nucleophile, such as diethanolamine, seems to be a better phosphate acceptor than water. These results may suggest that alkaline phosphatase from bone could be well suited for catalyzing phosphate transfer reactions in vivo as well.

[Fluoride deposition in the dental enamel following the use of a fluoride-containing gel studied by a nuclear physics method (PIGE)]. / Die Untersuchung der Fluorideinlagerung in den Zahnschmelz nach Anwendung fluoridhaltiger Gele mit einer kernphysikalischen Methode (PIGE).

The caries-preventing activity of fluorine is a surfact in the medicine. Dentists and physicists analysed with a new nuclear physical method the fluorine uptake of the tooth enamel after application of new caries-preventive agents. The fluorine profile of the first 3 microns of the enamel surface from deciduous teeth was established after three years clinical treatment with two new developed fluorine gels from the VEB Leipziger Arzneimittelwerk in comparison with Elmexgelee and a control agent. The determination of the fluorine profiles was performed using proton-induced gamma rays emission (PIGE) on the 2-MV van de-Graaf accelerator of the institute of practical nuclear physics of the physical faculty from the Karl-Marx-Universität Leipzig. The two new developed gels and Elmexgelee caused a similar fluorine concentration in tooth enamel. The fluorine profiles from the new developed gel A and the clinical approved caries preventive agent Elmexgelee are comparable. Gel A is produced under the trade mark "Laweflour" by the VEB Leipziger Arzneimittelwerk.

[Effects of inorganic and organic fluorides combined with molybdenum and chlorohexidine upon processes of metabolism, fluoride content, and cariosity of the teeth of Wistar rats (author's transl)]. / Der Einfluss anorganischer und organischer Fluoride in Kombination mit Molybdän und Chlorhexidin auf Stoffwechselprozesse, Fluoridgehalt und Kariesbefall der Zähne von Wistarratten.

A study has been made to determine the inhibitory action upon the progress of dental caries of two trace elements (fluorine and molybdenum) combined with chlorohexidine with the goal of increasing the efficiency of fluoride treatment. However, the results obtained show that the chosen combination of trace elements did not lead to a substantial increase in cariostatic action. Combined use of fluorides and chlorohexidine was seen to exert an inhibitory action on the progress of dental caries.

[Clinical and experimental animal studies made to determine the influence of topically applied chlorohexidine upon plaque formation, germ flora, and caries production (author's transl)]. / Klinische und tierexperimentelle Untersuchungen üben den Einfluss lokalapplizierten Chlorhexidins auf Plaquebildung, Keimflora und Kariesbefall.

A clinical and microbiological study has been made to determine, within a period of four weeks and on a total of ten Soviet schoolchildren, the effects of daily rinses with Polfa, a 0.2% solution of chlorohexidine gluconate, upon plaque formation, plaque flora, and gingival condition within the framework of controlled oral hygiene, with the subjects included in this program being twelve-year-olds. A 20-day experiment on forty Wistar rats was performed with the object of determining the effect of two applications per week of chlorohexidine upon both caries production and oral germ flora. Topical application of chlorohexidine resulted in a marked reduction of plaque formation, substantial improvement in gingival condition, and considerable decrease in the germ content of the plaque. A significant reduction in oral germ count could be determined in the experimental animals. However, it was not possible to observe a significant inhibition of caries production.

[Fluoride contents of rat molars following the administration of amine-fluoride-containing caries preventives (author's transl)]. / Der Fluoridgehalt von Rattenmolaren nach der Applikation aminfluoridhaltiger Kariespräventiva.

Experiments on fifty Wistar rats were conducted with the object of studying the incorporation of fluoride into the enamel of molars subsequent to the administration of amine-fluoride-containing caries preventives. - Use of two toothpastes with low fluoride contents of 0.125% and 0.18% F, respectively, and two higher-fluoride (1% F) solutions resulted in a marked increase in the concentration of fluoride in the superficial layers of dental enamel.

[Development of gingival inflammations in schoolchildren instructed in proper oral hygiene in a seven-year longitudinal study conducted under clinically controlled conditions and as part of the Preventive Stomatology research project (author's transl)]. / Entwicklung gingivaler Entzündungen bei mundhygienisch angeleiteten Schulkindern in einem siebenjärhrigen klinisch kontrollierten Längsschnittvergleich.

Instruction of six- and seven-year-old children (N = 1167) at the beginning of this longitudinal study was given by a stomatological nurse at weekly intervals and, later, at fortnightly and monthly intervals, respectively. Compared with a group of untreated controls were not only those children who were instructed in proper oral hygiene but children receiving additional doses of amine fluorides as well. During the seven-year period of observation there was noted a distinct improvement in oral hygiene (OHI) as well as a reduction of gingival inflammations (PM index). Whereas additional administration of amine fluorides had no appreciable effect upon both oral hygiene and the condition of health of the gingiva there was a direct relation to the frequency of instructions in oral hygiene at school.

[Clinical and microbiological studies on the effect of locally applied aminofluorides on bacterial plaque and gingiva condition of Soviet school children]. / Klinisch-mikrobiologische Untersuchungen über den Einfluss lokalapplizierter Aminfluoride auf bakterielle Plaques und Gingivazustand sowjetischer Schulkinder.

In a short-term (over 4 weeks) clinico-microbiological study on 18 Soviet school children, 12 years of age, it was found that a supervised oral hygiene action with the amine fluoride-containing caries-preventing agents Silca and Elmex fluid (produced in the GDR) had resulted in a marked reduction in plaque formation, an improvement in gingival conditions and a reduction of the germ content in the plaques.

[Clinical-radiological parallel control of a longitudinal study of the anti-caries effect of aminofluoride applied locally for 7 years in a double-blind test]. / Klinisch-röntgenologische Parallelüberwachung einer Längsschnittstudie zum Nachweis der Karieshemmenden Effektivität 7 Jahre lokal angewandten Aminfluorids im Doppelblindtest.

The determination of anticarious effects of topically administered fluorine compounds is usually based on short-time cross-sectional or longitudinal studies. In a comparison made for a period of more than seven years the anticarious effects of amine fluorides administered to selected groups of test subjects have been studied under controlled clinical experimental conditions.

[Caries protective action of a mineral solution in the presence and absence of fluorides in an animal experiment].

Experimental animal studies were made in an attempt to determine by means of series of sections the anticarious properties and effects of a locally applied mineral solution in the presence and absence of fluorides