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Biomedical subjects

J A Molinari

Publications and source records attributed to J A Molinari.

At least 109 records · Page 6Linked to original sources
PubMed1978

Quantitation of retention of endosseous dental blade implants in dogs.

This research was initiated in order to study the extraction forces associated with solid, single-vented and multi-vented blade dental implants placed in mandibles of dog for 2 months. An extraction device was used to measure the extraction forces on five of the implants and a histological study was carried out around the sixth multi-vented implant. The main finding was that the extraction forces for the multi-vented blade implants were 6 to 12 times those of the single-vented and solid blades. Other findings in this study were: none of the implants exhibited mobility; sulci ranged from 2 to 3 mm at the implant neck; bone covered the implant shoulder. There was gross and histologic evidence of bone growth in the vents of the multi-vented blade; close adaptation of the bone, connective tissue capsule and implant; and no gross, histologic, clinical or radiographic evidence of bone pathology.

Animals↗
PubMed1978

The induction of salivary antibodies by topical sensitization with particulate and soluble bacterial immunogens.

This investigation attempted to characterize systematically the secretory and serum immune responses following oral administration of soluble and particulate bacterial immunogens. Following oral sensitization of axenic mice with Escherichia coli lipopolysaccharide, Candidin, or streptococcal group H antigen, a substantially longer latent period was observed before all salivary samples exhibited specific agglutinins when compared to a similar immunization regimen with intact nonviable micro-organisms. Also, the peak titres of salivary agglutinins were significantly lower when the soluble antigenic counterparts of particulate E. coli or Candida albicans were utilized as immunogens. Examination of serum antibodies showed that following administration of E. coli LPS, similar titres of exocrine and serum agglutinins were noted. The serum titres were significantly greater (P less than 0.01) than those elicited by oral immunization with particulate E. coli. After termination of the topical immunization regimen, salivary agglutinins were found to decline rapidly whether immunization was via soluble or particulate antigens; however, immunization with particulate bacterial antigens appeared capable of stimulating and maintaining a higher rate of local antibody secretion than similar sensitization with soluble immunogen preparations.

Animals↗
PubMed1978

Secretory antibody responses in axenic mice to perorally administered Staphylococcus aureus.

Topical oral immunization of axenic mice with non-replicating Staphylococcus aureus resulted in the production of both serum and salivary agglutinins. A latent period of approximately 5 days was noted before salivary antibodies were detected against both a carbohydrate (ChoA) and a protein (PrA) antigen isolated from this micro-organism. The local response to ChoA exhibited a linear increase until day 9 when the reciprocal titres reached a plateau [32 (16--64)]. Salivary antibodies to PrA peaked by day 13 at a mean reciprocal titre of 60 (32--128). The agglutinin response in saliva was found to be initially IgG; however, by day 9 of a 14-day-immunization regimen, IgA became the predominant class of exocrine anti-S. aureus antibodies. The serum agglutinin response followed that found in saliva by approximately 2--4 days. By day 14, all sera (6/6) contained PrA agglutinins, while 4/6 sera agglutinated sheep erythrocytes coated with ChoA. Serum antibodies to ChoA were exclusively IgM, in contrast to IgM and IgA agglutinins elicited by PrA. Absorption studies provided evidence of a specific local and systemic immune response to both ChoA and PrA antigens of perorally administered S. aureus.

Agglutinins↗
PubMed1978

Specific antibody levels in the serum of Heligmosomoides polygyrus-infected mice.

Sera from ICR/CD mice were assayed by radial immunodiffusion following oral infection and challenge with Heligmosomoides polygyrus larvae. Infection of these mice was found to alter the concentrations and classes of immunoglobulins, as well as the levels of antiparasitic antibody. Challenge of single- or multiple-infected mice with viable larvae resulted in the appearance of anti-H. polygyrus IgA and IgG in the serum. The kinetics of the detection for both of these antibody classes were consistent with an anamnestic response to an antigen isolated from adult nematodes. There also appeared to be an association in resistant mice of serum IgA levels with early and late events in the life cycle of the parasite.

Animals↗
PubMed1977

Comparative study of vitreous carbon, pyrolytic carbon, pyrolytic graphite/silicon-carbide, and titanium implants in rabbit mandibles.

The purpose of the present investigation was to evaluate the biocompatibility of vitreous carbon, pyrolytic carbon, and pyrolytic graphite/silicon-carbide with rabbit mandibular tissues. Titanium was employed as the control material. Twelve New Zealand albino rabbits were implanted with each of the four materials described. Groups of four animals each were killed at 14 days, 45 days, and 90 days. Block sections containing the implants were then removed from the rabbit mandibles, and representative sections were evaluated histologically. All of the implants elicited similar reactions, including fibrous connective tissue capsule formation, multinucleated phagocytic cells, a mild inflammatory infiltrate, and reactive bone. On the basis of these findings, it appears that further detailed investigations are necessary to elucidate the biologic ramifications of the implantation of carbons in mammalian tissues.

Animals↗
PubMed1977

Gastrointestinal antibody responses in axenic mice to topically administered Escherichia coli.

Immunoglobulin levels were determined in gastrointestinal secretions of both conventional and axenic mice, as was the stability of the immunoglobulin classes in these secretions. Axenic animals were then administered nonviable Escherichia coli O111:B4 by topical application into the oral cavity. Immunoglobulin (Ig) A, IgG1, AND IgG2 were detected in the gastrointestinal secretions, with an apparent gradation in stability (IgA greater than IgG1 greater than IgG2) under the conditions investigated. Specific antibodies (IgA and IgG) to both the somatic and the flagellar antigens of E. coli were demonstrated. The time course of the responses to the polysaccharide and protein antigens suggested that a secondary response to lipolysaccharide was being observed in the secretions. Examination of the autoclaved diet fed to the germfree animals indicated the presence of antigenically intact polysaccharide materials (i.e., lipopolysaccharides), whereas antigenic bacterial proteins were uniformly undetectable. Therefore, endotoxin in the diet was apparently causing a primary type of sensitization in the mice, whereas the active oral immunization regimen induced a secondary antibacterial response in the secretions.

Animal Feed↗
PubMed1977

Antineoplastic effects of long-term Trichinella spiralis infection on B-16 melanoma.

Oral infection of mice with Trichinella spiralis has been shown to induce a potentiation of the delayed hypersensitive (DTH) response to BCG. The present investigation was initiated to determine whether nematode-induced potentiation of DTH influenced the induction and progression of a transplantable mouse tumor. B6D2F1/J mice were orally infected with 200 T. spiralis larvae 176 days preceding subcutaneous administration of 5 X 10(5) viable B-16 melanoma cells. The antineoplastic effects of long-term nematode infection were assessed by daily observation of the animals monitoring development and progression of neoplastic nodules. Control mice developed tumors by day 28 following tumor challenge, while none of the corresponding T. spiralis-infected animals demonstrated any signs of neoplasia. All control mice died within 60 days, while none of the nematode-infected animals developed detectable neoplasms. This phenomenon suggested that the presence of well-established larval cysts was capable of stimulating host antineoplastic activity.

Animals↗
PubMed1977

In vitro responses of spleen cells from Trichinella spiralis-infected mice.

The in vitro cellular immune responses of spleen cells from mice infected with Trichinella spiralis and immunized with BCG have been investigated. ICR/CD-1 mice were originally infected with 200 T. spiralis larvae 22 days prior to infection with 4 X 10(6) viable or heat-killed mycobacteria. Analysis of the splenic cell populations indicated that significant increases in adherent cells (macrophages) were noted only in groups previously infected with the nematode; the concentration of non-adherent cells (lymphocytes) did not vary insignificantly among any of the experimental groups. Assay of blast cell transformation and 3H-thymidine incorporation demonstrated the ability of T. spiralis infection to potentiate in vitro cellular immune reactions. These findings support earlier in vivo studies concerning nematode-induced immunopotentiation of delayed-type hypersensitivity reactions, and provide additional evidence that infection with this nematode enhances the immune capabilities of both stimulated lymphocytes and nonspecific phagocytic cells.

Animals↗
PubMed1977

Specific antibody levels in the intestinal perfusates of Heligosomoides polygyrus-infected mice.

Radial immunodiffusion analysis was performed on intestinal perfusates from ICR/CD1 mice following oral infection and challenge with viable Heligosomoides polygyrus larvae. Infection of these mice resulted in an alteration in the amount and class of immunoglobulins, as well as anti-parasitic antibody. Specific IgA peaked at 3 days post-infection and then showed a gradual decline until day 21. This rapid elevation in IgA levels was temporally associated with early events in the parasite life cycle, and the increase in IgA was significantly higher in mice infected twice with H. polygyrus prior to challenge. Differences in both the concentrations and kinetics of specific IgA and IgG1 were also observed in the perfusates from these mice when compared to those noted for animals infected only once.

Animals↗
PubMed1976

Specificity of secretory antibodies to bacterial immunogens.

The present investigation examined the specificity of the salivary immune response of axenic and conventional mice to topically administered Salmonella typhi, S. gallinarum, and S. typhimurium. Specific antibacterial antibodies were determined by passive hemagglutination and bacterial agglutination. Reciprocal antibody titers up to 320 were detected in saliva from mice immunized and assayed with homologous antigens. Antibodies to heterologous immunogens exhibited lower mean titers of 10 to 20 under identical conditions. High concentrations of specific antibodies to the somatic (O) antigen were detected in the saliva of mice administered these microorganisms; however, no significant differences in serum antibody levels were detectable after oral immunization. Only low levels of specific antiflagellar (H) antibodies were demonstrated in the saliva of immunized mice, whereas mean reciprocal titers of 20 were observed in the serum. Antibodies to the Vi antigen of S. typhi were detected in the saliva and serum of only those mice administered formalin-treated S. typhi. Examination of the classes of antibody elicited by these organisms indicated that immunoglobulin A (IgA) was the predominant class in saliva against the O antigens. The salivary response to the H antigens was comprised of both IgG and IgA, whereas the specific serum immunoglobulins were consistent with a primary humoral immune reaction. Local antibodies formed in response to the Vi antigen were exclusively IgG. Serum immunoglobulins produced after peroral administration of the somatic and virulence antigens were limited to the IgM class.

Animals↗
PubMed1975

Immunological sequelae of Trichinella spiralis infection in mice: effect of viability and route of BCG administration on nematode-induced immunopotentiation.

Mice were infected with 200 Trichinella spiralis 22 days preceding administration of 4 times 10-6 viable or heat-killed BCG. The effect of the route of BCG administration on the subsequent delayed hypersensitivity response to old tuberculin was investigated by injecting the bacteria either intravenously, intraperitoneally, or subcutaneously. Animals of the various groups were tested for delayed hypersensitivity footpad responses 28 days after BCG inoculation. Infection with T. spiralis was found to potentiate the ability of mice to respond to both viable and heat-killed BCG. In the case of heat-killed BCG, this potentiation appeared to be route dependent, since it could not be demonstrated when the bacilli were injected subcutaneously.

Animals↗
PubMed1975

Sequential appearance of salivary antibodies after oral immunization of axenic mice.

The purpose of the present investigation was to examine the production of specific salivary antibodies after oral immunization of axenic mice (ICR/CD-1) with formalinized Escherichia coli (ATCC 11775). Three aspects of the humoral response were studied: (i) the sequential appearance of anti-E. coli antibodies; (ii) classes of antibodies produced in response to the antigen; and (iii) antibody specificity. Antibody levels were determined by passive hemagglutination with soluble lipoplysaccharide and bacterial agglutination, using preparations of somatic O and flagellar H antigens. A short latent period of 1 to 3 days was observed when saliva samples were assayed for anti-lipopolysaccharide and anti-O antibodies. The salivary antibody titers peaked at 11 days after initiation of the immunization regimen. Only two of six mice exhibited a change in serum antibody levels against these antigens. The predominant class of early antibody in saliva was immunoglobulin (Ig)G; however by 7 days IgA WAS found to comprise the major portion of specific immunoglobulins. Serum antibodies directed against falgellar antigenic determinants were primarily of the IgM class, whereas the salivary antibodies were IgG in nature.

Administration, Oral↗
PubMed1975

Effect of infection with Trichinella spiralis and BCG on thymic histology.

The histology of mouse thymic tissue was examined following infection with Trichinella spiralis and/or BCG. ICR/CD-1 mice were orally infected with 200 T. spiralis 56 days preceding intravenous administration of 4x10-6 viable BCG. Following assessment of delayed hypersensitive foot pad reactions to BCG, the mice were bled and sacrificed. The thymus was removed from each animal, fixed in 10% neutral buffered formalin, embedded in paraffin and cut in 4 mum sections. Examination of serial sections indicated that T. spiralis and T. spiralis-BCG infections induced distinct anatomical changes within the thymic cortex and medulla, which may be related to previously described functional alterations of the immune system.

Animals↗
PubMed1975

Modification of surface membrane antigens by trypsin.

Cultured 3T3 and PY-3T3 mouse fibroblasts were subjected to mild treatment with twice crystallized trypsin and their immunogenicity tested in ICR/CD-1 mice. Surface antigenic modifications were observed using the foot pad swelling assay for detection of delayed hypersensitive responses. Mice immunized with trypsin-treated 3T3 cells showed cell-mediated immune reactions following challenge with either homologous antigen or untreated PY-3T3 fibroblasts. In contrast, treatment of the virus-transformed cells with trypsin decreased their antigenicity as determined by this in vivo assay.

Animals↗
PubMed1974

Immunological sequelae of Trichinella spiralis infection in mice. II. Potentiation of cell-mediated response to BCG after infection with Trichinella spiralis.

Mice were infected with 200 Trichinella spiralis 14 days after intravenous administration of 4 x 10(6) viable BCG cells. Individual groups were tested for delayed hypersensitive footpad responses at 14, 20, 29, 57, or 85 days after T. spiralis infection. An initial suppression in the 14-day test group was observed; however, mice tested at later time intervals exhibited potentiation of the 24-h footpad reaction to old tuberculin over that elicited by appropriate controls. This suggested that T. spiralis induces a potentiation of the cellular immune response to BCG. Adoptive transfer studies support the cell-mediated nature of the observed footpad reaction and indicated that the initial suppression was not due to physiological factors preventing the expression of the footpad swelling reaction.

Animals↗