scholarly journals Properties of maltodextrins and glucose syrups in experimentsin vitroand in the diets of laboratory animals, relating to dental health

2000 ◽  
Vol 84 (4) ◽  
pp. 565-574 ◽  
Author(s):  
T. H. Grenby ◽  
M. Mistry
Keyword(s):  
Dental Caries ◽  
Acid Production ◽  
Large Scale ◽  
Dental Health ◽  
Laboratory Animals ◽  
Degree Of Polymerisation ◽  
Laboratory Rats ◽  
Glucose Syrup ◽  
Micro Organisms

The objective of the study was to examine the cariogenic potentials of maltodextrins and glucose syrups (two glucose polymers derived from starch) using a range of techniquesin vitroand in laboratory animals. The experimental methods used were: (1) measurement of acid production from glucose syrups and maltodextrins by human dental plaque micro-organisms; (2) evaluation of the role salivary α-amylase in degrading oligosaccharides (degree of polymerisation >3) in the glucose polymers, estimating the products by HPLC; (3) assessment of the fermentability of trioses relative to maltose; (4) measurement of dental caries levels in three large-scale studies in laboratory rats fed on diets containing the glucose polymers. It was found that acid production from the glucose polymers increased as their higher saccharide content fell. Salivary α-amylase rapidly degraded the oligosaccharides (degree of polymerisation >3), mainly to maltose and maltotriose. In the presence of oral micro-organisms, maltotriose took longer to ferment than maltose, but by the end of a 2 h period the total amount of acid produced was the same from both. Incorporated into the diets in solid form, the glucose syrups and maltodextrins were associated with unexpectedly high levels of dental caries. In conclusion, the findings were unforeseen in the light of earlier data that a glucose syrup was less cariogenic than sucrose.

scholarly journals Characterization of Recombinant, Ureolytic Streptococcus mutans Demonstrates an Inverse Relationship between Dental Plaque Ureolytic Capacity and Cariogenicity

2000 ◽  
Vol 68 (5) ◽  
pp. 2621-2629 ◽  
Author(s):  
K. Anne Clancy ◽  
Sylvia Pearson ◽  
William H. Bowen ◽  
Robert A. Burne
Keyword(s):  
Dental Caries ◽  
Streptococcus Mutans ◽  
Urease Activity ◽  
Dental Health ◽  
Oral Bacteria ◽  
Streptococcus Salivarius ◽  
Specific Pathogen ◽  
The Relationship

ABSTRACT Dental caries results from prolonged plaque acidification that leads to the establishment of a cariogenic microflora and demineralization of the tooth. Urease enzymes of oral bacteria hydrolyze urea to ammonia, which can neutralize plaque acids. To begin to examine the relationship between plaque ureolytic activity and the incidence of dental caries, recombinant, ureolytic strains ofStreptococcus mutans were constructed. Specifically, theureABCEFGD operon from Streptococcus salivarius57.I was integrated into the S. mutans chromosome in such a way that the operon was transcribed from a weak, cognate promoter inS. mutans ACUS4 or a stronger promoter in S. mutans ACUS6. Both strains expressed NiCl2-dependent urease activity, but the maximal urease levels in ACUS6 were threefold higher than those in ACUS4. In vitro pH drop experiments demonstrated that the ability of the recombinant S. mutans strains to moderate a decrease in pH during the simultaneous metabolism of glucose and urea increased proportionately with the level of urease activity expressed. Specific-pathogen-free rats that were infected with ACUS6 and fed a cariogenic diet with drinking water containing 25 mM urea and 50 μM NiCl2 had relatively high levels of oral urease activity, as well as dramatic decreases in the prevalence of smooth-surface caries and the severity of sulcal caries, relative to controls. Urease activity appears to influence plaque biochemistry and metabolism in a manner that reduces cariogenicity, suggesting that recombinant, ureolytic bacteria may be useful to promote dental health.

scholarly journals On the Bactericidal Effect exerted by Human Blood on certain species of Pathogenic Micro-Organisms and on the Antibactericidal Effects obtained by the addition to the blood in vitro of Dead Cultures of the Micro-Organisms in question

1902 ◽  
Vol 2 (4) ◽  
pp. 385-413 ◽  
Author(s):  
A. E. Wright ◽  
F. N. Windsor
Keyword(s):  
Streptococcus Pyogenes ◽  
Human Blood ◽  
Bactericidal Effect ◽  
Laboratory Animals ◽  
Bactericidal Action ◽  
Pathogenic Organisms ◽  
Micro Organisms

The fact that the blood of ordinary laboratory animals exerts a very marked bactericidal effect upon the Bacillus typhosus and the Spirillum cholerae asiaticae, while it exerts little or no effect upon the Staphylococcus and Streptococcus pyogenes, has hardly received the attention which it would seem to merit in view of the circumstance that these facts involve the important problem as to whether the blood exerts its bactericidal action upon pathogenic organisms generally, or only upon certain species of such micro-organisms.

scholarly journals Dental and metabolic effects of lactitol in the diet of laboratory rats

1989 ◽  
Vol 61 (1) ◽  
pp. 17-24 ◽  
Author(s):  
T. H. Grenby ◽  
A. Phillips
Keyword(s):  
Dental Caries ◽  
Body Fat ◽  
Dental Plaque ◽  
Large Scale ◽  
Food Product ◽  
Metabolic Effects ◽  
Food Utilization ◽  
Fat Storage ◽  
Low Level ◽  
Laboratory Rats

1. Because so little is known about the properties of lactitol as a possible alternative bulk sweetener to sucrose, it was tested in two large-scale experiments in laboratory rats. Matched groups of caries-active Osborne-Mendel rats were fed on uniform diets containing lactitol and compared with a sucrose control in both experiments, plus a xylitol control in the first experiment.2. In the early stages of the experiments weight gains and food utilization were better on the sucrose than on the lactitol regimens. Body-fat storage was higher on the sucrose than on the polyol regimens.3. At the end of 8 weeks the mandibular molars were examined for dental plaque accumulation and dental caries. The dental caries scores when 160 g sucrose/kg in the diet was replaced by lactitol were lower by a highly significant margin, bringing them down to the same low level as those on a 160 g xylitol/kg regimen.4. Testing lactitol in a manufactured food product, shortbread biscuits, in comparison with ordinary sucrose biscuits, showed differences in plaque scores (significant) and caries levels (highly significant), with 60% fewer lesions on the lactitol regimen.5. The results confirm the low cariogenic potential of lactitol, but show metabolic differences compared with sucrose.

scholarly journals Non-Invasive and Minimum Invasive Concepts in Prevention, Cariology and Endodontics – from Research and Science to Practice

2018 ◽  
Vol 45 (1) ◽  
pp. 55-60
Author(s):  
Ekaterina Boteva
Keyword(s):  
Dental Caries ◽  
Dental Health ◽  
Polarized Light ◽  
Gastrointestinal Diseases ◽  
Practical Experience ◽  
Preparation Methods ◽  
Individual Level ◽  
Root Canals ◽  
Dental Tissues

AbstractThe minimum invasive dental concept is based on practical experience of more than 30 years negative trends from the use of resin materials in distal teeth and early metal-ceramic “aesthetic” crowns and bridges. The scientific dental research includes all aspects of the conservative dentistry treatment which are scientifically and clinically proved with most up to date methods and tests: anthropometric, epidemiological, biochemical, immunohistochemical, electron microscopy, polarized light microscopy, light induced fluorescence, microradiography, microbiology, genetic tests, etc. Experiments in vitro, animal tests, clinical research in the last 34 years are focused in the field of prevention of dental caries, treatment of precavitated precarious lesions with nanotechnologies, preparation of hard dental tissues with most conservative techniques, adhesive restoration methods with amalgam and resins, backup in endodontics in root canals preparation methods and in pins and posts fixations. The conclusions can be focused on basic principles and refocused in the 21st century like: Dental caries is not only predictable and controlled disease but is also a polyetiological disease on a community and population levels and uni- or bi-etiological on an individual level. The minimum invasive dental concept in cariology and endodontics leads to prevention of early extractions, early prosthetic medical procedures and to lifetime dental health. This plays a key role in prevention of metabolic disorders and gastrointestinal diseases.

Replacement Therapy for the Prevention of Dental Disease

1987 ◽  
Vol 1 (1) ◽  
pp. 119-125 ◽  
Author(s):  
J.D. Hillman ◽  
S.S. Socransky
Keyword(s):  
Dental Caries ◽  
Replacement Therapy ◽  
Periodontal Diseases ◽  
Oral Bacteria ◽  
Periodontal Pathogens ◽  
Wild Type ◽  
Laboratory Rats ◽  
Natural Variant

Certain laboratory-derived and naturally occurring oral bacteria are promising effector strains for the replacement therapy of dental infectious diseases. In the case of dental caries, several types of low-acid-producing mutants of Streptococcus mutans and a natural variant of S. salivarius have been found that are virtually non-cariogenic. Laboratory rats can be readily and persistently infected with these micro-organisms. Once infected, the animals become much more resistant to infection by wild-type (disease-causing) strains of S. mutans. Thus, in the laboratory rat, replacement therapy has proved successful in providing lifelong resistance to dental caries following a single application of an effector strain. Attempts to extend these findings to humans have required a search for effector strains that can both colonize well and, in addition, displace indigenous, wild-type strains of S. mutans. A mutant of a strain of S. mutans producing a bacteriocin-like molecule has been found that appears to be well-suited for this purpose. Replacement therapy may also find a practical application in the prevention and cure of certain periodontal diseases. Hydrogen peroxide-producing streptococci are invariably found in plaque taken from healthy gingiva; they are rarely found in samples from active disease sites of patients with juvenile or refractory periodontitis. In vitro, peroxide production by these streptococci inhibits the growth of Actinobacillus actinomycetemcomitans and several other presumed periodontal pathogens. Bacterial interactions of this sort have also been directly demonstrated to occur in vivo. Thus, natural inhibitors in plaque may be essential for maintenance of periodontal health. Patients lacking such inhibitors may be treated by replacement therapy to restore the composition of their plaque flora to one that is conducive to health.

scholarly journals MODELS OF WOUND HEALING

2021 ◽  
Vol 10 (4) ◽  
pp. 64-71
Author(s):  
A. Yu. Tsibulevskiy ◽  
T. К. Dubovaya ◽  
I. A. Demyanenko
Keyword(s):  
Wound Healing ◽  
Large Scale ◽  
Laboratory Animals ◽  
Skin Wounds ◽  
Physiological Processes ◽  
Complex Process ◽  
History Of ◽  
Chronic Skin

Simulations of human disease in laboratory animals have continuously accompanied the history of medical discoveries and have helped researchers obtain useful information in medicine. The separation of physiological processes into their constituent components through modeling is one of the important parts of any research. Wound healing is a complex process. Using of models (in vitro, in vivo - on animals and humans) allowed large-scale research in this area, which significantly improved the knowledge of the healing mechanisms of both acute and chronic skin wounds. In parallel with the knowledge gained, the development of new wound treatments continues and the understanding of how to improve their care for the best results continues. Although in vitro and animal models have a place in these studies, by far the best models are those that rely on volunteers and provide physiologically more accurate mechanisms of skin pathogenesis and healing.

Purification of the Antihemophilic Factor by Gel Filtration on Agarose

1969 ◽  
Vol 22 (03) ◽  
pp. 577-583 ◽  
Author(s):  
M.M.P Paulssen ◽  
A.C.M.G.B Wouterlood ◽  
H.L.M.A Scheffers
Keyword(s):  
Factor Viii ◽  
Plasma Proteins ◽  
Large Scale ◽  
Gel Filtration ◽  
Large Scale Preparation ◽  
Scale Preparation ◽  
Antihemophilic Factor

SummaryFactor VIII can be isolated from plasma proteins, including fibrinogen by chromatography on agarose. The best results were obtained with Sepharose 6B. Large scale preparation is also possible when cryoprecipitate is separated by chromatography. In most fractions containing factor VIII a turbidity is observed which may be due to the presence of chylomicrons.The purified factor VIII was active in vivo as well as in vitro.

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