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R J Genco

Publications and source records attributed to R J Genco.

At least 217 records · Page 12Linked to original sources
PubMed1982

Regression line analysis of neutrophil chemotaxis.

Polymorphonuclear leukocyte chemotaxis and chemokinesis, in the micropore filter assay, have been evaluated using Regression Line Analysis. The method discriminates between migration rate and the number of migrating cells by statistical comparison of the slope of the regression line and the y-intercept, respectively. The derivation of this new method of assessment of cell migration is reported. This report also includes critical evaluation of the chemokinesis dose/response curve and the directional component of chemotaxis. The effect of inhibitors of chemotaxis were evaluated using the new method. Colchicine was found to effect the directional component of chemotaxis, as indicated by decreased rate of locomotion in chemotaxis experiments, and had no effect on random migration and chemokinesis. Cytochalasin B had a general inhibitory effect upon cell locomotion by depressing the rate of random migration and chemotaxis. 1-Tosylamide-2-phenylethyl chloromethylketone (TPCK) had the apparent effect of uncoupling the receptor and effector mechanisms of chemotaxis or altering the binding of the chemotactic ligand, since random migration was unaffected but the rate of chemotaxis and chemokinesis were depressed. Ionophore A23187 had a generalized inhibitory effect on the cell rate under all three conditions; however, at low concentrations it induced an increase in the number of migrating cells. These studies indicate that the method of regression line analysis is effective in differentiating in vitro the mechanisms of chemotaxis inhibition. The method may be used effectively in the assessment of defective neutrophil chemotaxis in disease states and may prove a useful adjunct to the study of cell locomotory mechanisms.

Calcimycin↗
PubMed1982

The polymorphonuclear leukocyte (PMNL) locomotor defect in juvenile periodontitis. Study of random migration, chemokinesis and chemotaxis.

Neutrophil locomotion was evaluated in three groups of periodontal patients, localized juvenile periodontitis (LJP), post-localized juvenile periodontitis (post-LJP), and generalized juvenile periodontitis (GJP). This was accomplished using regression line analysis, a new method for analysis of neutrophil locomotion in vitro. Neutrophil random migration, chemotaxis and chemokinesis were measured. The present study demonstrates that neutrophil locomotion is reduced in all three patient groups. The reduction in locomotion of the neutrophils in LJP, GJP and in post-LJP patients is due to a decrease of neutrophil migration in the presence of a chemotactic gradient. Furthermore, this decrease in chemotactic response is likely due to a decrease in rate of migration of the population of neutrophils rather than the existence of a large population of poorly responsive neutrophils. Random migration and chemokinesis of these patients' neutrophils are normal. These findings are consistent with our previous findings that the neutrophil locomotor disturbance in juvenile periodontitis is cell-associated and not due to humoral factors, and that there are a reduced number of chemotactic factor receptors present on the cell surface.

Adolescent↗
PubMed1982

Inhibition of neutrophil chemotaxis by soluble bacterial products.

BACTERIAL-NEUTROPHIL INTERACTIONS may be critical determinants of virulence in periodontal diseases. This study was undertaken to examine the ability of major bacterial species from the human oral cavity to inhibit (1) peripheral blood neutrophil chemotaxis, (2) chemotactic formylmethionyl peptide binding, and (3) phagocytosis. Included were cultured supernatants and sonic extracts obtained from strains of Capnocytophaga, Bacteroides gingivalis, Fusobacterium nucleatum, Bacteroides asaccharolyticus, Capnocytophaga species, Actinobacillus actinomycetemcomitans, Neisseria, Actinomyces viscosus, Bacterionema matruchotii, Streptococcus mitis, Streptococcus mutans, and Streptococcus sanguis. Chemotaxis was measured using Boyden chambers; phagocytosis was determined using Staphylococcus aureus as the indicator organism and radioactive chemotactic peptide binding was assessed by a rapid filtration assay. None of the test organisms were cytotoxic to neutrophils or inhibited neutrophil phagocytosis. Capnocytophaga species., Bacteroides species., A. actinomycetemcomitans, and F. nucleatum produced factors which specifically inhibited neutrophil chemotaxis. Activity was lost after dialysis. Extracts of Bacteroides species, A. actinomycetemcomitans and F. nucleatum, which were not chemotactic by themselves, inhibited binding of chemotactic peptide suggesting that in vitro chemotaxis inhibition was mediated by nonchemotactic components that compete for the chemotactic factor receptor on the neutrophil. The exception was Capnocytophaga which appeared to inhibit chemotaxis by inhibition of a post-binding event. Such chemotactic inhibitors from periodontopathic organisms that inhibit neutrophil function may be important determinants of virulence.

Bacteria↗
PubMed1982

Human immune responses to oral micro-organisms. I. Association of localized juvenile periodontitis (LJP) with serum antibody responses to Actinobacillus actinomycetemcomitans.

The association between periodontal disease in humans and serum and salivary antibody to Actinobacillus actinomycetemcomitans strain Y4 was determined. An Elisa was used to examine anti-Y4 antibody of the IgM, IgG, IgA and IgE isotypes in serum from 127 individuals and IgA in parotid saliva. Patients diagnosed as having localized juvenile periodontitis (n = 37) had significantly higher levels and frequency of serum IgG antibodies to Y4 than all other groups. Serum and salivary IgA and serum IgE antibody levels were significantly increased in patients with both localized and generalized types of juvenile periodontitis (n = 48) when compared to all other patient groups. Specificity studies suggested that the antigenic determinants that were differentiating the group responses were unique to the Y4 organism. These results indicate that serum antibodies to Y4 may reflect an infectious process with this micro-organism and that these responses may provide some diagnostic value in delineating different types of periodontal diseases.

Actinobacillus↗
PubMed1981

Potential salicylamide antiplaque agents: in vitro antibacterial activity against Actinomyces viscosus.

A series of 55 salicylamides, including 3,5-dibromo-, 5-n-alkyl-, and 5-n-acylsalicyloyl derivatives of various anilines, heterocyclic amines, benzylamines, and alkylamines, was synthesized and evaluated for in vitro antibacterial activity against Actinomyces viscosus, an adherent oral microorganism implicated in periodontal disease. The in vitro minimum inhibitory concentrations of 15 4'-bromosalicylanilides were found to correlate (r = 0.92) with estimated log D values. Several nonhalogenated salicylanilides, such as 5-n-hexyl- (40) and 5-n-decanoyl-4'-nitrosalicylanilide (47), were found to exhibit higher levels of in vitro antibacterial activity against a number of Actinomycetes than did tribromsalan (1) or fluorophene (2).

Actinomyces↗
PubMed1981

Serum neutralizing activity against Actinobacillus actinomycetemcomitans leukotoxin in juvenile periodontitis.

A relatively high incidence of infection by Actinobacillus actionomycetemcomitans can be shown in subgingival plaque samples obtained from patients with juvenile periodontitis. These organisms possess a potent leukotoxin(s) which rapidly destroys isolated human polymorphonuclear leukocytes (PMNs) and monocytes. If such leukotoxins operate in vivo, they could deprive the gingival crevice area of an essential antibacterial defense mechanism. We have found that sera from juvenile periodontitis patients consistently (greater than 90%) contain antibodies which neutralize Actinobacillus actinomycetemcomitans leukotoxin(s). On the other hand, sera from normal individuals or patients with other types of periodontal disease usually amplified rather than inhibited the leukotoxic reaction. Many patients with juvenile periodontitis have demonstrable defects in PMN or monocyte chemotaxis and this may place them at risk to gingival infection by Actinobacillus actinomycetemcomitans. The immune response against these organisms could be a crucial determinant in the course of juvenile periodontitis. While this disease is relatively rare, it does cause immeasurable emotional, physical and economic hardship for patients and their families. The identification of Actinobacillus actinomycetemcomitans as a potential pathogen in this disorder may eventually lead to specific forms of therapy to prevent and eliminate infection by this organism in these patients.

Actinobacillus↗
PubMed1981

Serum antibodies to oral Bacteroides asaccharolyticus (Bacteroides gingivalis): relationship to age and periondontal disease.

An enzyme-linked immunosorbent assay microplate method was used for measuring levels of antibody specific for the oral serotype of Bacteroides asaccharolyticus (Bacteroides gingivalis) in serum samples obtained from umbilical cords, infants, children, periodontally normal adults, and edentulous adults. Serum from patients with various periodontal diseases, including adult periodontitis, localized juvenile periodontitis, generalized juvenile periodontitis, post-localized juvenile periodontitis, and acute necrotizing ulcerative gingivitis, were also studied. A positive correlation between increase in age and increase in both prevalence and level of specific antibody in the G, A, and M classes of immunoglobulins was observed. This indicates that antibodies reactive with oral B. asaccharolyticus found in up to 84% of normal adults are natural antibodies, presumably with a protective role. Among the patient groups, those with adult periodontitis were found to have levels of immunoglobulin G antibodies to oral B. asaccharolyticus that were five times higher than the antibody levels found in control subjects. The levels of IgG antibodies to this organism in the other patient groups were comparable to the levels found in the control group. However, 50% of the individuals in the generalized juvenile periodontitis group had high levels of immunoglobulin G antibodies to B. asaccharolyticus, suggesting heterogeneity with respect to immune response in these patients. These results indicate that antibodies to oral B. asaccharolyticus (B. gingivalis) occur at low levels in most normal children and adults and that the rise in titer of the specific antibodies of each major class of immunoglobulins parallels the ontogenic change in serum levels of that isotype. In contrast, there is a marked increase in titer of immunoglobulin G antibodies to oral B. asaccharolyticus in the group of patients with adult periodontitis and in patients with the generalized form of juvenile periodontitis.

Adult↗
PubMed1981

Use of combined immunization routes in induction of a salivary immunoglobulin A response to Streptococcus mutans in Macaca fascicularis monkeys.

Various combinations of immunization routes were examined for ability to elicit or prolong (or both) a salivary secretory immunoglobulin A response to Streptococcus mutans strain Ingbritt (serotype c) in Macaca fascicularis monkeys. Intraductal (i.d.), per os (p.o.), and subcutaneous (s.c.) routes were utilized. Four groups of three to five monkeys each were immunized by the following schedules: group I--p.o., s.c., i.d.; group II--i.d., p.o., i.d.; group III--s.c., p.o., i.d.; and group IV--control. Immune responses in the serum and parotid fluid were quantitated by using passive hemagglutination assays with purified serotype-specific polysaccharide and by indirect immunofluorescent staining assays. Both s.c. and i.d., but not p.o., routes resulted in detectable serum antibody responses. Only i.d. immunization resulted in a measurable salivary response. Indirect immunofluorescent staining revealed specific secretory immunoglobulin A antibodies in the parotid fluid which correlated with passive hemagglutination titers. The p.o. procedures used in this study did not result either in a prolonged immune response or in measurable tolerance related to the humoral or secretory immune system.

Administration, Oral↗
PubMed1981

Eubacterium saburreum and Veillonella parvula: a symbiotic association or oral strains.

A cocci-filament association was discovered in bacterial cultural studies of a subgingival plaque sample. Components were isolated and identified as Veillonella parvula and Eubacterium saburreum. A E. saburreum cell-associated material consisting of approximately 25% glucose and 70% protein was found which may play a role in the adherence of V. parvula to this filament. Acid end product analysis via gas liquid chromatography showed an uptake of lactic and succinic acids by V. parvula resulting in increased levels of acetic, propionic and n-butyric acids in mixed culture of the E. saburreum and the V. parvula strains. The ability of E. saburreum to adhere to nichrome wire and to glass surfaces as well as the secondary plaque forming ability of V. parvula indicates that these organisms may play a role in the maturation of human dental plaque.

Dental Plaque↗