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Biomedical subjects

J W Vincent

Publications and source records attributed to J W Vincent.

35 records · Page 2Linked to original sources
PubMed1986

Spandra: a sustained release battlefield wound dressing.

In 1981, our laboratories developed a family of elastomers which could be cured by ultraviolet (UV) radiation. Curing by UV radiation was a significant advance in chemistry, since it allowed ultra-fast curing of elastomers in a matter of seconds, as compared to several hours at 110 degrees C for conventional heat curing. We applied for a patent based on this technology, and the patent was allowed in mid-1984 [29]. Based on this technology, Thermedics submitted a proposal to the US Army for the development of a sustained-release battlefield wound dressing containing antibiotics and coagulants. The drugs were evenly distributed in the oligomer matrix, and subsequently cured in seconds under UV illumination, without the use of heat, organic solvents or water. Because delicate drugs are not subjected to heat, organic solvents or water, the pharmacological activity of the drugs is insured. Therefore, theoretically any drug may be incorporated into our dressing. Sustained release dressings were first developed at Thermedics in 1983, spurred by a contract from the US Army Medical Research and Development Command. Under this contract, the Company developed a new type of wound dressing capable of accelerating the healing process, retarding infection, and minimizing pain. Based on our TECOFLEX materials technology, the dressing performs like temporary artificial skin. Its transmission properties for oxygen, carbon dioxide, and water vapor are similar to those of intact skin. Thus, while excluding bacteria from the wound site, the dressing maintains an optimal moist environment for the promotion of rapid healing. The new drawing shown in Figure 10 minimizes pain during healing by preventing dehydration and shrinkage in the wound. Patient comfort is also enhanced by the incorporation of a special fabric which imparts flex properties to the bandage that are almost identical to those of human skin, with greater stretch in one direction than in another. This also facilitates application to complex body contours by only one attendant, an important feature in both hospital and emergency situations. Materials currently in use in hospitals are difficult to handle, requiring two or three nurses to apply large dressings. Thermedics' military wound dressing not only has the significant advantage of ease of application, but this dressing can also be used for delivery of drugs to a specific site.(ABSTRACT TRUNCATED AT 400 WORDS)

Administration, Cutaneous↗
PubMed1986

Systemic antibody response of clinically characterized patients with antigens of Eubacterium brachy initially and following periodontal therapy.

Eubacterium brachy, a gram-positive anaerobic rod, has been implicated by cultural studies to be associated with the microflora of periodontal diseases. Serum samples from 184 clinically characterized patients were evaluated in a standardized enzyme-linked immunosorbent assay (ELISA) for reactivity to E. brachy antigens. Sera from clinically healthy subjects (HS) served as controls. Sera from rapidly progressive periodontitis (RP) patients demonstrated significantly greater reactivity by ELISA than did HS when reactivity with E. brachy antigens was determined (P less than 0.05). Juvenile periodontitis (JP) and adult periodontitis (AP) patients did not differ in reactivity by ELISA from HS (P greater than 0.05). Three to 4 years following successful periodontal therapy, reactivity was not significantly altered in any patient group (P greater than 0.05). The possible significance of these findings and the importance of an extracellular antigen of E. brachy in the immunopathology of periodontal diseases are discussed.

Adolescent↗
PubMed1985

Specificity of monoclonal antibodies reactive with Fusobacterium nucleatum: effect of formalin fixation.

Monoclonal antibody specific for Fusobacterium nucleatum was reacted with untreated and formalin fixed F. nucleatum cells by an enzyme-linked immunosorbent assay (ELISA) and by indirect immunofluorescence. Treatment of bacterial cells with formalin destroyed the antigenic determinant responsible for reactivity with this monoclonal antibody in both assays. Formalin fixation had no effect on hemagglutination activity (HA) of F. nucleatum cells or reactivity with polyvalent rabbit antiserum in double diffusion in agar. Scanning electron microscopy demonstrated that formalin fixation did not affect binding of F. nucleatum cells to microtiter plates. When developing monoclonal antibodies to be used as diagnostic reagents, the antigenic form utilized for immunization should be identical to the antigenic form which will eventually be used in the diagnostic assay.

Animals↗
PubMed1985

Reaction of human sera with Eubacterium brachy: isolation and characterization of an extracellular antigen.

Recent studies have demonstrated an association of Eubacterium sp. with the subgingival microflora of patients with chronic periodontitis. One species, Eubacterium brachy, was evaluated to determine the possible mechanisms by which this microorganism may contribute to these diseases. Of 167 sera evaluated by double diffusion in agar, 20.8% displayed reactivity with a sonicated preparation of E. brachy. An extracellular antigen was identified in the culture supernatant fluid which reacted with antibodies in human sera. This antigen was isolated by methanol precipitation and purified by gel filtration. When tested by an enzyme-linked immunosorbent assay, all sera displayed some reactivity. Lines of identity were not shared with other species of Eubacterium, but were shared with other clinical isolates of E. brachy. The reactive antibody was identified as immunoglobulin G by immunoelectrophoresis, verified by enzyme-linked immunosorbent assay, and found to be capable of complement fixation. The monosaccharides and amino acids of the extracellular antigen were identified by high-pressure liquid chromatography. This antigen was shown to have a molecular weight of 170,000 and to share a line of identity with the sonicated preparation of E. brachy. The possible role of the organism in the immunopathology of periodontal diseases is discussed.

Amino Acids↗
PubMed1985

Biologic activity of type I and type II Fusobacterium nucleatum isolates from clinically characterized sites.

Fusobacterium nucleatum is a microorganism commonly cultured from periodontal disease sites. F. nucleatum isolates (120) were obtained from subgingival plaque samples taken from 27 clinically characterized sites using a selective culture medium. All isolates were verified by morphology, Gram-stain reactions, oxygen tolerance and biochemical reactions. A total of eight clinical isolates and two typed strains were used for further evaluation. In this study, there was no relationship found between GI and probing depth or between probing depth and frequency of isolation of Type I or Type II F. nucleatum colonies. There was a significant increase in isolation of Type II colonies with a GI of 2 (P less than 0.0001). All isolates tested shared lines of identity by double diffusion in agar and displayed similar ability to hemagglutinate sheep erythrocytes and a reduction in this hemagglutination activity by previous exposure to 50 mM D-galactose. All isolates tested showed similar protein patterns as determined by polyacrylamide gel electrophoresis. By the methods used, no differences were detected between Type I and Type II F. nucleatum; however, there was a statistically significant increase in Type II isolates with increasing levels of gingivitis.

Adult↗
PubMed1985

Reaction of human sera from juvenile periodontitis, rapidly progressive periodontitis, and adult periodontitis patients with selected periodontopathogens.

The levels of serum antibody reactive to selected periodontopathogens were determined in 182 clinically characterized patients: 35 healthy control, 50 juvenile periodontitis, 42 adult periodontitis and 55 rapidly progressive periodontitis. Reactive antibody levels were determined using an enzyme-linked immunosorbent assay with whole cell preparations of Bacteroides gingivalis, Capnocytophaga (Bacteroides) ochraceus, Fusobacterium nucleatum and Actinobacillus actinomycetemcomitans (Y-4) serving as antigens. Increased reactivity to B. gingivalis and F. nucleatum was observed in all three disease groups studied while antibody reactive to A. actinomycetemcomitans was increased in juvenile and rapidly progressive periodontitis. Antibody levels reactive to C. ochraceus in healthy subjects did not differ from those observed in any disease patient groups. Possible implications in the etiology and progression of the diseases coupled with environmental changes which occur in the econiche of the periodontal pocket are described.

Actinobacillus↗
PubMed1984

Eubacterium brachy. Reactivity in in vitro bone resorptive bioassay.

Recent studies have demonstrated an association of Eubacterium sp. with the subgingival microflora of patients with chronic periodontitis. One species, Eubacterium brachy, was evaluated to determine the possible mechanisms by which this microorganism may contribute to this disease. An extracellular antigen was identified in the culture supernatant which reacted with antibodies in human sera. This antigen was isolated by methanol precipitation and purified by gel filtration. The purified extracellular antigen was reacted in vitro with 45CaCl2-labeled fetal rat bone in a bone resorptive bioassay. This antigen was shown to have a molecular weight of 170,000, to share a line of identity with a sonicated preparation of E. brachy whole cells and to result in increased 45CaCl2 release from fetal rat bones when cultures were exposed to the purified extracellular antigen at concentrations of 10 to 53 micrograms/ml.

Animals↗
PubMed1983

Comparison of serological reactions of typed Fusobacterium nucleatum strains with those of isolates from humans, canines, and a Macaca mulatta monkey.

In the present study, we compared typed F. nucleatum strains with isolates from various human periodontal diseases, canines, and a Macaca mulatta monkey. All isolates displayed biochemical reactions similar to those of the typed strains in the API 20A system (Analytab Products, Plainville, N.Y.). The human and monkey isolates displayed both type I and type II colonial morphologies on crystal violet erythromycin agar, whereas the canine isolates displayed only type I. Antigen preparations of the human isolates, typed strains, and two of the monkey strains shared lines of identity in immunodiffusion testing. An enzyme-linked immunosorbent assay in which rabbit anti-F. nucleatum and human sera were used revealed that the human and monkey isolates, when used as antigens, allowed the detection of similar degrees of antibody activity; however, no activity was observed with the canine isolates. None of the canine isolates displayed the characteristic hemagglutination of sheep erythrocytes demonstrated by the human and monkey strains. These results suggest that F. nucleatum isolates from various human periodontal diseases share antigenic determinants. Also, differences were observed in F. nucleatum isolates from canines when compared with human and monkey strains. These findings are important when considering the immunopathological mechanisms involved in human periodontal diseases and when comparing animal model systems with naturally occurring disease in humans.

Animals↗
PubMed1982

The ELISA system for measuring antibody reactive to Fusobacterium nucleatum in the sera of patients with chronic periodontitis.

Humoral IgG, IgA and IgM responses to three typed oral strains of F. nucleatum were examined in patients with chronic periodontitis and in individuals with clinically healthy gingiva. Attempts were made to isolate F. nucleatum from either the pathologic gingival crevices or healthy sulci in this study. Higher levels of IgG and IgA reactive to all three strains were observed in the chronic periodontitis patients; however, there were no differences between the IgM levels in the diseased and healthy individuals. Immunodiffusion studies with rabbit antiserum and adsorption studies of the human sera demonstrated a sharing of antigenic determinants by the F. nucleatum strains. F. nucleatum strains were isolated from 14 of the 15 individuals in the study.

Antibodies, Bacterial↗
PubMed1980

Reduction of luxation of the temporomandibular joint--an extraoral approach.

The method, as described, will not reduce all luxations of the TMJ. Some patients with severe muscle spasm of long duration may require general anesthesia. However, in the vast majority of patients encountered by the author, the method described was quite successful. It was performed so easily that several patients who had recurrent problems have since been able to reduce their own luxations.

Humans↗
PubMed1976

Assessment of attached gingiva using the tension test and clinical measurements.

The attached gingiva on the facial surface of the mandibular central incisors was evaluated by measurements and the "tension test" on 226 subjects between the ages of 8 and 22 years. Findings of significance were: 1. As age increased a definite increase in width of attached gingiva occurred. 2. There was no increase in the frequency of a positive tension test in older age groups. 3. No relationship was observed when results of the tension test were compared with clinical measurements of attached gingiva.

Adolescent↗