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Biomedical subjects

A Gaffar

Publications and source records attributed to A Gaffar.

71 records · Page 4Linked to original sources
PubMed1982

In vitro evaluation of editempa on hydroxyapatite formation and its effects on dental enamel.

N,N,N',N' ethylene diamine tetra (methylene phosphonic acid)-Editempa inhibited the formation of hydroxyapatite (HA) in vitro at 4 ppm. In the seeded crystal growth of HA at 37 degrees C, it completely inhibited the crystal growth at 0.5 ppm. C14-Editempa adsorbed to HA crystal at 37 degrees C. The maximum adsorption was 1.29 mumol/m2 of HA and the adsorption was monolayer. Compared to the natural inhibitors of HA in saliva (Statherin and Proline-rich proteins), Editempa was more effective in vitro on weight basis. At 0.3 ppm, it inhibited growth rate of the crystals by 80% while 4 to 5 ppm of the natural inhibitors were needed to get the same effect. The inhibition of rates with Editempa was not directly proportional to the area covered by it on the HA seeds (occupied less than 10% of the surface). The natural inhibitors, on the other hand, seemed to cover all the available surface. These data indicate that the inhibition with Editempa was due to binding to specific sites on the surface of the seeds. The solutions up to 5% of Editempa did not damage or etch the surface of human dental enamel in vitro at pHs 5.0 and 7.5, as evaluated by scanning electron microscopy and calcium released in the exposed solutions.

Adsorption↗
PubMed1981

Recovery of cellular immune competence during treatment of protein-calorie malnutrition.

Fifty Bangladeshi children with severe protein-calorie malnutrition were randomly allocated at admission to four groups and sensitized to dinitrochlorobenzene either immediately or after 1, 2, or 3 wk of protein-calorie replacement therapy. Ability to initiate cutaneous hypersensitivity to dinitrochlorobenzene on admission was impaired when the total serum proteins was less than 5.5 g/dl, but uniformly recovered after 1 wk of feeding. Three severely malnourished children with total serum proteins less than 4.5 g/dl in whom sensitization was attempted before refeeding failed to respond despite repeated challenge, suggesting immunological tolerance to dinitrochlorobenzene. The data support the concept of a threshold serum protein level, at least as an indicator, below which cellular immunity may be temporarily, or even permanently, impaired.

Blood Proteins↗
PubMed1981

Evaluation of an oligomer or an oligomer plus cetyl pyridinium chloride against plaque, stain, calculus, and gingivitis.

A low molecular weight oligomer of sulfoacrylic acid (ND-2) was effective in inhibiting hydroxyapatite formation in vitro at 33 ppm from a saturated solution of calcium and phosphate. The oligomer did not damage or etch human dental enamel in vitro at pH 5.0 and 7.5. It significantly reduced calculus formation when applied topically in beagles at a concentration of 1% in a rinse. In a second study using 30 beagle dogs, the rinses containing 0.1% CPC and 0.1% CPC + 2% ND-2 significantly reduced (alpha less than 0.05) plaque and gingivitis for 12 wk when compared to a placebo rinse. One-tenth percent CPC rinse induced more discoloration of teeth than the placebo, while the rinse containing 0.1% CPC + 2% ND-2 had significantly less discoloration than CPC rinse or the placebo rinse in beagles. Thus the oligomer was effective in reducing CPC-induced discoloration in beagles.

Acrylic Resins↗
PubMed1981

Long-term antiplaque, anticalculus, and antigingivitis effects of benzethonium/polymer complex in beagle dogs.

An electrostatic complex of 0.1% benzethonium chloride (BTC) plus 0.05% copolymer of methoxyethylene and maleic acid was evaluated in vitro for antibacterial effect. The complex by itself showed as much antibacterial activity as 0.1% BTC. The adsorption of 14C-BTC on saliva-coated hydroxyapatite disks and teeth in vitro was lower from the complex than the BTC solution, although in vivo activity was the same. The complex, BTC, and polymer solutions were evaluated in a 28-week study in 16 beagle dogs against plaque, gingivitis, and calculus formation. BTC and the complex significantly (alpha = 0.05) reduce plaque and gingivitis. There was no significant difference between the two active groups. BTC (0.1%) significantly increased calcified deposits at 22-28 wk compared to the water control group, while the complex and the polymer groups showed significantly (alpha = 0.05) less calculus. Thus, the complex was not only effective in vivo, but also significantly (alpha = 0.05) reduced tendencies of cationic antibacterials to induce calcified deposits on teeth.

Adsorption↗
PubMed1981

Penetration of dental plaque components into gingiva: sequential topical treatments with hyaluronidase and streptococcal polysaccharide in rats.

EIGHTY-FIVE Sprague-Dawley rats were used in two experiments to determine the conditions necessary to permit transepithelial penetration by deleterious macromolecules in murine oral mucosa. In experiment one, Group I was a water and diet control; Group II mucosa was treated with hyaluronidase; Group III with streptococcal polysaccharide; and Group IV with hyaluronidase, followed by treatment with the polysaccharide. In the second experiment, the histological effects of the streptococcal polysaccharide were quantified by administering a series of concentrations, from 10 mg/ml to 100 microgram/ml. The results suggest that tissue-damaging plaque components, such as hyaluronidase and polysaccharide, act in combination to pass through the epithelial structures into the subjacent connective tissues to cause destructive changes in rat gingiva. Such changes may possibly be related to those seen in the periodontium when it is adjacent to dental plaque.

Animals↗
PubMed1980

Hydrogen sulfide production from gingival crevicular fluid.

A METHOD was developed and evaluated in a pilot study to determine a relationship between gingival health, crevicular fluid flow and the production of H2S from the crevicular fluid. A moderate degree of correlation was observed between the crevicular fluid volume and the gingival index. A stronger correlation was obtained between the crevicular fluid volume and H2S production by the crevicular fluid. The method described could prove useful in evaluating gingival health and disease objectively and for monitoring the activity of periodontitis.

Adult↗
PubMed1979

Xerophthalmia, protein-calorie malnutrition, and infections in children.

All children with evidence of xerophthalmia who were admitted to an inpatient facility for treatment of severe protein-calorie malnutrition and its complications were compared to other inpatients with severe PCM but free from signs or symptoms of vitamin A deficiency. Xerophthalmic inpatients were older and had more severe hypoproteinemia than inpatients without eye signs, and were more undernourished by anthropometric criteria than a comparison group matched for age, sex, and type of PCM. Children with more severe eye lesions were more retarded in growth than those with minimal ocular signs. All inpatients had high rates of bacterial infections, regardless of their vitamin status. However, xerophthalmic children had a highly significant increase in the rate of positive urine cultures. Mortality rates were similar in all study groups.

Bacterial Infections↗
PubMed1966

Amino acid compostion of walls from single and filamentous cells of Clostridium acidiurici.

Gaffar, Abdul (Brigham Young University, Provo, Utah), David R. Terry, and Richard D. Sagers. Amino acid composition of walls from single and filamentous cells of Clostridium acidiurici. J. Bacteriol. 91:1618-1624. 1966.-The walls from single and filamentous cells of Clostridium acidiurici were shown to contain 11 amino acids: aspartic acid, serine, glutamic acid, proline, d-alanine, glycine, valine, methionine, valine, leucine, phenylalanine, and lysine. In the walls from cells grown at 37 C, d-alanine was the amino acid present in largest quantity, but in the walls from cells grown at 44 C there was a 50% reduction in the d-alanine content while the levels of the other amino acids were unchanged. Filamentous cells grown at 44 C, then brought to 37 C and transferred to fresh medium, fragmented into short cells within 30 min. Alanine racemase activity was the same in extracts from cells grown at both 37 and 44 C, suggesting that this enzyme was not the major controlling factor in the low content of d-alanine in filaments grown at 44 C. Spent medium from cultures grown at 44 C contained a significant amount of d-alanine, whereas there was no evidence of this amino acid in the spent medium from cultures grown at 37 C.

Alanine↗
PubMed1966

Filament formation in Clostridium acidiurici under conditions of elevated temperatures.

Terry, David R. (Brigham Young University, Provo, Utah), Abdul Gaffar, and Richard D. Sagers. Filament formation in Clostridium acidiurici under conditions of elevated temperatures. J. Bacteriol. 91:1625-1634. 1966.-Vegetative cells of Clostridium acidiurici, when grown at temperatures up to 42 C, are straight rods varying from 2.5 to 4 mu in length. When grown at 43 C, the cells show a definite tendency to elongate, and, when grown at 44 C, filaments are formed, often exceeding 500 mu in length. Only an occasional cross wall is apparent in the heat-induced long forms, but as the temperature is lowered they readily form cross walls and fragment into short, single cells. Chromatin material is distributed in evenly spaced clusters throughout the length of the filaments. The filaments grown at 44 C are gram-negative, whereas cells grown at 37 C are gram-positive. However, filament formation and gram-negativity apparently are not due to magnesium deficiency, since the gram-negative filaments are formed in concentrations of magnesium ranging from 10(-6) to 10(-2)m. The rapid transition from filaments to single cells upon lowering the temperature from 44 to 37 C suggests that the temperature-related repression of the cross wall-forming system is a phenotypic response rather than the selection of specific mutants which produce the observed phenomena.

Ammonia↗
PubMedDate not supplied

Effect of a triclosan-containing toothpaste supplemented with 10% xylitol on mutans streptococci in saliva and dental plaque. A 6-month clinical study.

The aim of the present investigation was to evaluate the effect of the combination of triclosan and xylitol in toothpaste on mutans streptococci (MS) in saliva and dental plaque. 155 individuals with >10(5) MS/ml saliva were included in a 6-month double-blind clinical study. They were divided into three groups (n = 51-52) balanced according to their MS counts at baseline. Each group used one of the following types of dentifrice: (1) Colgate Total with the addition of 10% xylitol (Total-Xylitol), (2) Colgate Total and (3) Colgate Total without triclosan and without xylitol. Whole saliva and pooled plaque samples were obtained after 2, 4 and 6 months. When comparing the MS counts within the groups for saliva and plaque samples, Total-Xylitol showed significant reduction at all three sampling occasions (p < 0.001). Mean reduction at the 6-month sample for saliva was 0.81/ml and for plaque 0.89 per sample (log values). ANOVA revealed significant differences between Total-Xylitol and the two other products at 6 months for MS in saliva and dental plaque. The conclusion from this 6- month study is that the addition of 10% xylitol to a triclosan-containing dentifrice reduces the number of MS in saliva and dental plaque.

Adult↗