Creating a Natural Vascular Scaffold by Photochemical Treatment of the Extracellular Matrix for Vascular Applications.

The development of bioscaffolds for cardiovascular medical applications, such as peripheral artery disease (PAD), remains to be a challenge for tissue engineering. PAD is an increasingly common and serious cardiovascular illness characterized by progressive atherosclerotic stenosis, resulting in decreased blood perfusion to the lower extremities. Percutaneous transluminal angioplasty and stent placement are routinely performed on these patients with suboptimal outcomes. Natural Vascular Scaffolding (NVS) is a novel treatment in the development for PAD, which offers an alternative to stenting by building on the natural structural constituents in the extracellular matrix (ECM) of the blood vessel wall. During NVS treatment, blood vessels are exposed to a photoactivatable small molecule (10-8-10 Dimer) delivered locally to the vessel wall via an angioplasty balloon. When activated with 450 nm wavelength light, this therapy induces the formation of covalent protein-protein crosslinks of the ECM proteins by a photochemical mechanism, creating a natural scaffold. This therapy has the potential to reduce the need for stent placement by maintaining a larger diameter post-angioplasty and minimizing elastic recoil. Experiments were conducted to elucidate the mechanism of action of NVS, including the molecular mechanism of light activation and the impact of NVS on the ECM.

Immunoglobulin class of agglutinins to oral microorganisms in post-irradiation cancer patients.

Fractionation of serum samples from head and neck cancer patients and their assay for agglutination activity toward oral microorganisms showed that the activity was derived from IgG, 7S IgA, 10S (dimeric) IgA, and IgM, with considerable activity in the 10S IgA region. These findings probably account for the lack of a significant relationship among levels of individual serum immunoglobulins, agglutination titers, and caries activity presented in an earlier study. Conversely, most of the agglutinating activity in fractionated saliva was attributed to 11S IgA, presumably secretory IgA, with some activity from a 19S substance and, in the caries-active patients, from a higher molecular weight factor. These data correspond to positive correlations between saliva IgA levels, agglutination titers, and absence of caries in these patients.

Effects of a single application of sodium fluoride gel on dental plaque acidogenesis.

Quantitative comparisons of the lactate and acetate produced by human dental plaque in vitro and in situ were made before and after five-minute exposures to 1% NaF gel. Assays included total ionic plaque fluoride by a fluoride electrode, L(+)- and D(-)-lactate by an enzyme method, and acetate by a standard GLC procedure. A single topical application of NaF gel increased plaque fluoride about eight-fold. Six hours after gel use, plaque fluoride had declined to about 20% above pretreatment levels. Plaque fluoride baseline levels and variation between and within subjects were greater than expected. This may have been due largely to non-standardized oral hygiene practice and/or the routine use of fluoride dentifrices and the wide variation in the natural fluoride content of drinking water. Fluoride gel use significantly reduced L(+)-lactate in vitro, but D(-)-lactate and acetate were virtually unaffected. Conversely, gel use significantly inhibited the in situ production of each of these acids. The findings of this study indicate that topically applied fluoride gel impairs plaque acidogenesis to an extent that could be meaningful in preventing dental caries.

Relationship between saliva and serum agglutination titers and post-irradiation caries activity in cancer patients.

Agglutination titers in 444 saliva and 481 serum samples from 36 head and neck cancer patients and 16 control subjects were determined against formalinized cellular antigens of Streptococcus and Lactobacillus species. Saliva agglutination titers were significantly higher in cancer patients before radiotherapy than in control subjects. Changes in specific saliva agglutination titers to oral isolates following radiotherapy reflected changes in saliva IgA and post-irradiation caries activity. Patients with no post-irradiation caries activity had significantly higher saliva agglutination titers to S. mutans, S. sanguis, and L. fermenti, lower plaque S. mutans counts, and higher saliva IgA levels than those with post-irradiation caries activity. Serum agglutination titers were unrelated to either serum immunoglobulin levels, microbial counts, or caries activity.

Comparison of the plaque microflora in immunodeficient and immunocompetent dental patients.

The nature and extent of the immune dysfunctions in 20 immunodeficient patients, as well as the immunocompetence of 22 control subjects, were verified by cell-mediated responsiveness and immunoglobulin quantitations. Comparisons of the microbial composition of supragingival plaque between the two populations showed that a greater number of immunodeficient than control subjects harbored Candida sp. and Staphylococcus sp. Conversely, a lower number of immunodeficient than control subjects harbored Streptococcus mutans. Also, patients with immune dysfunctions had a lower dental caries experience than their immunocompetent counterparts.