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B D Schobel

Publications and source records attributed to B D Schobel.

7 recordsLinked to original sources
PubMed2006

Influence of cranberry juice on glucan-mediated processes involved in Streptococcus mutans biofilm development.

Cranberry juice (CJ) has biological properties that may provide health benefits. In this study, we investigated the influence of CJ (pH 5.5) on several activities in vitro associated with the development of Streptococcus mutans UA159 biofilms. The ability of CJ to influence the adherence of S. mutans to either saliva- (sHA) or glucan-coated hydroxyapatite (gsHA), and to inhibit the glucan production by purified glucosyltransferases adsorbed to sHA was determined. For the adherence assays, we used both uncoated and saliva-coated bacterial cells. Furthermore, we examined whether CJ interferes with the viability, development, polysaccharide composition and acidogenicity of S. mutans biofilms. A solution containing equivalent amounts of glucose, fructose and organic acids at pH 5.5 was used as negative control. The adherence of S. mutans (uncoated and saliva-coated) to either sHA or gsHA treated with 25% CJ (v/v) was remarkably reduced (40-85% inhibition compared to control: p < 0.05), indicating that CJ effectively blocked the bacterial adherence to binding sites in salivary pellicle and in glucans. In contrast, when the bacterial cells alone were treated with CJ they adhered to the similar untreated surfaces. Cranberry juice (25%, v/v) also inhibited the activities of surface-adsorbed GTF B and C (70-80% inhibition compared to control, p < 0.05). The effect of CJ on the viability of microorganisms in biofilms was not significant. Biofilm formation and accumulation were significantly reduced by topical applications of 25% CJ (v/v) twice daily with 1-min exposures (p < 0.05). The biomass and insoluble glucan content of the biofilms in addition to its acidogenicity were significantly reduced by cranberry treatments (p < 0.05). Our data show that cranberry juice inhibited glucan-mediated biofilm development and acid production, and holds promise as a natural product to prevent biofilm-related oral diseases.

Analysis of Variance↗
PubMed2003

Inhibition of Streptococcus mutans biofilm accumulation and polysaccharide production by apigenin and tt-farnesol.

OBJECTIVES: Apigenin is a potent inhibitor of glucosyltransferases and tt-farnesol affects the membrane integrity of Streptococcus mutans. We investigated the influence of apigenin and tt-farnesol, alone and in combination, on the accumulation, polysaccharide composition and viability of S. mutans UA159 biofilms. METHODS: Initially, biofilms were grown for 54 h; then, the early-formed biofilms were treated for 1 min twice daily with one of the following: (i). 1.33 mM tt-farnesol; (ii). 1.33 mM apigenin; (iii). apigenin + tt-farnesol (1.33 mM each); (iv). vehicle control (20% ethanol with 0.75% dimethyl sulphoxide); (v). 0.12% chlorhexidine (1.33 mM); or (vi). physiological saline (145 mM NaCl). The procedure was repeated at biofilm ages of 78 and 102 h, and biofilms were harvested at 126 h. The dry weight, protein concentration, number of cfu, and polysaccharide composition per biofilm were determined. RESULTS: The dry weights of the biofilms treated with the test agents were significantly less (30-50%) than those treated with vehicle control (P < 0.05). Biofilms treated with the test agents also resulted in lower amounts of extracellular alkali-soluble glucans, intracellular iodophilic polysaccharides and, to a lesser extent, fructans. The fructosyltransferase activity was affected only by apigenin and apigenin + tt-farnesol. The recoverable viable counts of S. mutans were slightly lower (0.5 to 1 log10 decrease in cfu/biofilm) after apigenin and tt-farnesol treatments compared with the vehicle control. Chlorhexidine displayed potent bactericidal activity, and virtually halted the further accumulation of early-formed (54 h old) biofilms. CONCLUSIONS: Apigenin and tt-farnesol affected the accumulation and polysaccharide content of S. mutans biofilms without major impact on the bacterial viability.

Anti-Infective Agents, Local↗
PubMed1982

Characteristics of newly awarded recipients of the Social Security regular minimum benefit.

The regular minimum Social Security benefit, which was eliminated for both current and future recipients under the Omnibus Budget Reconcilliation Act of 1981 (Public Law 97-35), was restored for current beneficiaries only under additional legislation at year end. Following passage of Public Law 97-35, a study was undertaken to examine a group of newly eligible beneficiaries who would formerly have received the minimum benefit but, under that law, would not. Although the persons sampled have since become eligible for the benefit under the subsequent legislation, they closely resemble other future beneficiaries who will not be eligible for it. This article, which reports the findings of the study, indicates that those who will be ineligible for the minimum benefit in the future are mainly housewives, who will usually be able to receive larger benefits as spouses, and persons with significant noncovered employment, who will still receive windfall benefits to some extent. The data tend to disprove the notion that those who will not receive the minimum benefit in the future are lifetime low-earners.

Aged↗
PubMed1981

Administrative expenses under OASDI.

Costs of administering old-age, survivors, and disability insurance (OASDI) are of interest both to specialists in income maintenance and to the general public. This article presents a summary of these expenses compared with several important bases: Contribution income, benefit payments, and taxable payroll. An index is developed and used to analyze changes in administrative expense levels from 1960 through 1979. Over the long run, the cost of operate OASDI per unit of work has increased more slowly than for service industries in general, a trend that should continue in the old-age and survivors insurance program (OASI). Although implementing the 1980 Disability Amendments will raise disability insurance (DI) unit costs, these higher expenses are necessary to obtain the more selective benefit payments provided in this cost-saving legislation.

Costs and Cost Analysis↗