Reaction of rat pulp tissue to Carisolv 'new gel'--a histocytological evaluation.

BACKGROUND: This study was an histological examination of pulp tissue exposed to Carisolv 'new gel' after 1 to 28 days. METHODS: An occlusal cavity was prepared in 64 caries-free molar teeth of 16 Wistar rats. The roofs of the pulp chambers were perforated and Carisolv 'new gel' solution was placed onto the exposed pulps of 32 molar teeth for 20 minutes. Thirty-two contralateral molar teeth served as controls and were coated with an inert liquid containing isotonic saline solution and carmellose for 20 minutes as well. The pulps of all teeth were capped with Ca(OH)2 and the cavities were filled with a flowable composite in combination with a self-etching dentine adhesive. The animals were sacrificed after 1, 3, 7 and 28 days. Eight teeth per group and the time period were histologically examined, scored, and statistically evaluated (Wilcoxon-test). RESULTS: The results showed no statistically significant differences between the Carisolv group and the control group (p > 0.05). The observed pulp reaction was essentially the same as those reported in the past being typical for the effect of calcium hydroxide as a direct pulp capping agent. CONCLUSION: Compared to Ca(OH)2, Carisolv 'new gel' did not cause any different or additional pulp reaction in healthy teeth.

Histocytological evaluation of the reaction of rat pulp tissue to Carisolv.

OBJECTIVES: Carisolv is a viscous substance for the chemo-mechanical removal of caries. The aim of this study was to examine the tissue reactions of pulp and dentin tissue to Carisolv in vivo. METHODS: In 48 caries-free molars (24 Wistar rats, age: 3 months) an occlusal cavity was prepared. The roofs of the pulp chambers were perforated with a sharp probe and Carisolv solution was placed onto the exposed pulp of 24 molars for 1, 10 and 20 min. Twenty-four contralateral molars served as controls and were coated with an inert liquid containing isotonic saline solution, carmellose and erythrosin. RESULTS: After a contact period of 10 and 20 min in the experimental group, pulpal destruction of intercellular substance and cells including odontoblasts was observed up to a depth of 150 microm, in addition to the mechanical damage by perforation (e.g. dentin particles). The pulpal and predentin fibrils as well as the dentin fibrils appeared to be intact and did not differ from the controls. After a contact time of 1 min a weaker damage of pulp cells and odontoblasts, as well as intact fibrils in pulp, predentin and dentin could be observed. CONCLUSIONS: Radicals of Carisolv (OH- and OCI-) cause alkaline hydrolysis of cellular components but do not decompose collagenous tissue components.

Automated mode-of-action detection by metabolic profiling.

Rapid classification and identification of the mode-of-action of bioactive compounds applied to plants can be achieved by a robust and easy-to-use metabolic-profiling method. This method uses artificial neural network analysis of one-dimensional proton NMR spectra of aqueous plant extracts to rapidly classify changes in the total metabolic profile caused by application of crop protection chemicals.

High-performance liquid chromatographic and capillary electrophoretic enantioseparation of plant growth regulators and related indole compounds using macrocyclic antibiotics as chiral selectors.

Enantioseparation of plant growth regulators, such as 3-(3-indolyl)-butyric acid, abscisic acid and structurally related molecules including a variety of substituted tryptophan compounds, has been achieved by HPLC and/or CE. The covalently bonded macrocyclic antibiotics, teicoplanin, ristocetin A and vancomycin, were used as chiral stationary phases (CSPs) in HPLC. Most of the racemates were baseline resolved in the reversed-phase mode (EtOH-H2O) using the teicoplanin CSP. The chiral recognition mechanism is discussed in regard to the structure of the analytes. In CE, the three aforementioned macrocyclic antibiotics were used as chiral additives in a phosphate run buffer. The effect of pH and the concentration of the organic modifiers were considered. The results obtained by HPLC and CE were compared.

Avoparcin, a new macrocyclic antibiotic chiral run buffer additive for capillary electrophoresis.

Avoparcin, like vancomycin, teicoplanin, and ristocetin A, belongs to the family of macrocyclic glycopeptide antibiotics. These antibiotics have all been used as effective chiral selectors for capillary electrophoresis (CE), thin-layer chromatography (TLC), and high performance liquid chromatography (HPLC). The present work focuses on avoparcin, which has been shown to be an excellent chiral selector for the CE enantioseparation of many N-blocked amino acids, as well as several anti-inflammatory drugs of pharmaceutical importance. The use of avoparcin as a chiral run buffer additive in CE is discussed, as well as the effects of changing experimental parameters, like avoparcin concentration, pH, organic modifiers, etc. Comparisons of enantioseparations of some N-3,5-dinitrobenzoyl-derivatized amino acids, using either avoparcin, ristocetin A, teicoplanin, or vancomycin in the run buffer, are also made. In general, vancomycin had the longest migration times, and ristocetin A the shortest, while avoparcin was intermediate. Generally, at least one of the four chiral selectors produced an excellent separation, while a different macrocyclic antibiotic produced a poor separation. Currently, we see no way to predict which chiral run buffer additive will be best or worst for an individual solute.

Evaluation of the macrocyclic antibiotic avoparcin as a new chiral selector for HPLC.

Avoparcin is a macrocyclic glycopeptide antibiotic structurally related to vancomycin, teicoplanin, and ristocetin A. When attached to 5-microns spherical silica gel, the avoparcin proved to be an effective chiral stationary phase (CSP) that could be used in the reversed-phase, normal-phase, and polar-organic modes. The avoparcin CSP was complimentary to the other macrocyclic glycopeptide CSPs in that it could resolve some racemates that the others could not, and vice versa. Some important compounds resolved on the avoparcin CSP include verapamil, thyroxine, mephenytoin, and 2-imidazolidone-4-carboxylic acid. The use of this CSP and the optimization of separations on it are discussed. Avoparcin appears to be a useful addition to this family of CSPs.

Highly enantioselective HPLC separations using the covalently bonded macrocyclic antibiotic, ristocetin A, chiral stationary phase.

The macrocyclic glycopeptide, ristocetin A, was covalently bonded to a silica gel support and evaluated as a liquid chromatographic (LC) chiral stationary phase (CSP). Over 230 racemates were resolved in either the reversed-phase mode, the normal-phase mode, or the polar-organic mode. The retention behavior and selectivity of this CSP were examined in each mode. Optimization of separations on this column is discussed. The ristocetin A CSP appeared to be complimentary to other glycopeptide CSPs (i.e., vancomycin and teicoplanin). Column stability was excellent. The CSP was not irreversibly altered when going from one mobile phase to another.

Rational molecular design and genetic engineering of herbicide resistant crops by structure modeling and site-directed mutagenesis of acetohydroxyacid synthase.

Plants with specific resistance to a single class of herbicides have been genetically engineered by introduction of genes encoding rationally designed mutant acetohydroxyacid synthase (AHAS) enzymes. Suitable substitution mutations were identified from a three-dimensional model of an AHAS-inhibitor complex. The structural model was generated based on homology to pyruvate oxidase and an imidazolinone inhibitor was positioned in the proposed binding site using structure-activity data for this class of herbicide. Biochemical analysis of the mutant proteins expressed in Escherichia coli enabled iterative optimization of the mutant genes. Expression of recombinant proteins in tobacco plants conferred resistance in vivo. The novel approach coupling molecular modeling and molecular biology has many advantages over traditional random mutagenesis and selection methods and will be crucial to the future development for environmentally safe and sustainable agricultural systems.

Evaluation of the concentration and enantiomeric purity of selected free amino acids in fermented malt beverages (beers).

Even though amino acids are important trace components in the brewing of beers, they have not been extensively evaluated in these beverages. Studies involving the enantiomeric composition of these amino acids are even less prevalent. A brief summary of the brewing process for malt beverages is given. The total concentration and enantiomeric composition of three amino acids (leucine, phenylalanine, and proline) were determined in 25 different beers. Proline tended to have the highest average absolute concentration and the lowest percentage of the D-enantiomer in most samples. In some cases the relative amounts of D-phenylalanine and D-leucine exceeded 10% of the individual amino acids. The enantiomeric composition of the amino acids in different beer samples did not vary as extensively as the absolute concentrations. The reason for the concentration differences between proline and the other amino acids is discussed. A knowledge of amino acid concentrations and enantiomeric compositions appears to be useful in characterizing specific beers and brewing processes.

Pharmacokinetics and tolerability of ventricularly administered superoxide dismutase in monkeys and preliminary clinical observations in familial ALS.

The discovery of mutations in the gene for Cu/Zn superoxide dismutase (SOD) in some cases of familial amyotrophic lateral sclerosis (FALS) provides a rationale for enzyme replacement therapy. The inability of SOD to cross the blood-brain barrier motivated this study of the safety, tolerability and pharmacokinetics of bovine SOD (bSOD) administered into the CSF of rhesus monkeys and one late-stage, SOD-deficient FALS patient. Kinetic analyses in the patient indicated that intracerebroventricular (i.c.v.) administration, but not lumbar administration, delivered bSOD to the entire CSF pathway. Daily bolus i.c.v. injections (32 mg/day) and continuous i.c.v. infusion (30 mg/day) were well tolerated by the patient. During the period of daily bolus injections, the patient's performance on manual muscle tests was nearly stable, in contrast with the rapid decline before and after that period. These results justify further investigation of bSOD therapy in SOD-deficient FALS patients.

[Studies on the reproducibility of recordings obtained with the Condylocomp LR 2]. / Untersuchungen über die Reproduzierbarkeit von Registrierungen mit dem Condylocomp LR 2.

The reproducibility of movement recordings obtained with the Condylocomp LR 2 was tested on three different types of articulator (Dentatus, SAM 2, Stuart). Additionally, reproducibility of TMJ movement recordings was tested on 18 subjects. Differences of +/- 2 degrees to the real angles, when working carefully, seem to be precise enough. The Condylocomp LR 2 seems to be a useful means for diagnosing and documenting TMJ movements, because it allows dynamic recordings with high resolution and correction of geometric errors.

[Clinical study of electrical root canal length instruments]. / Klinische Untersuchungen zur elektrischen Wurzelkanallängenbestimmung.

In a clinical study on 100 root canals we measured the difference between the length, which can be received by a roentgenogramme, and the length, which can be received by an electrical device. In cases with vital exstirpation in 80% we got a good conincidence, but in cases of pulp gangraena there were great differences. Indication of electrical devices for measuring tooth length only can be seen together with an existing X-ray; it is very important, whether the canal is dry enough for exact measuring.

[Study of properties of electrical root canal length measuring instruments]. / Untersuchungen über Eigenschaften von elektrischen Wurzelkanal-Längenmessgeräten.

Six electrical instruments for locating the apex during endodontic treatment were tested in a laboratory investigation about currency, frequency and scale. Further we looked, whether all instruments show coincidence in the apex point. There are great differences in currency, frequency and scale (apex point). The reproducibility and the precision of an apex locator--at the time--depends an many factors and thus indication seems to be very limited.

[Mercury in the hair of dentists and dental personnel]. / Quecksilber im Haar von zahnärztlichem Personal.

The mercury concentrations in the hair of 53 dentists, 49 dental assistants, 35 dental students and 35 non-exposed persons were analyzed by AAS and compared with a group of 22 factory workers producing chloride gas. The average mercury concentrations in the hair of the dentists was found to be twice as high as the amount measured in the non-exposed population, but only one quarter of that established for the factory workers. The dental assistants had 50% more mercury in their hair than the non-exposed group. The mercury concentrations did not correlate with age, sex, or number of amalgam fillings, but rather with the daily/weekly consumption of fish. The mercury concentrations in the hair of dentists and dental personnel found in this study were low, even when compared with international results; toxicologically their importance is negligible.

[Oral health in children after dental care under anesthesia]. / Mundgesundheit bei Kindern nach Gebisssanierung in Narkose.

Carious morbidity, oral hygiene, periodontal health, use of fluoride and therapeutic compliance were investigated in a clinical study of 41 children who had previously required insufflation anaesthesia for dental therapy. All of the children underwent postoperative treatment willingly; anaesthesia was not necessary in any of the cases. Half of the children still had a raised risk of caries; gingivitis was present in all of the children as a result of insufficient oral hygiene. For these reasons, all children that have undergone dental therapy under anaesthesia must subsequently be integrated in a programme of selective intensive prophylaxis.

Solution structure of mu-conotoxin GIIIA analysed by 2D-NMR and distance geometry calculations.

We have investigated the structure of mu-conotoxin GIIIA by 2D-NMR methods. The assignment of 1H NMR spectra and a quantitative analysis of NOE and J-coupling data are presented. These results were used for the calculation of secondary structure elements of mu-conotoxin GIIIA. Distance geometry calculations were carried out to define the global folding of the peptide.

[Study of temperature of composite resins during polymerization]. / Untersuchungen über das Temperaturverhalten von Komposit-Kunststoffen bei der Polymerisation.

Temperature was measured during polymerization of 24 composite materials within 5 minutes (up to 10 minutes) after starting polymerization. A sudden rise (10 K-18 K) of temperature could be observed in most of the materials; soon afterwards the primary situation was reached again. The measured high temperatures should be considered to might be one of the factors, which lead to an affection of the pulp tissue.