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Biomedical subjects

T Lehner

Publications and source records attributed to T Lehner.

At least 235 records · Page 13Linked to original sources
PubMed1978

Passive immunization with antisera to Streptococcus mutans in the prevention of caries in rhesus monkeys.

1) The immunological mechanism of protection against dental caries has been investigated by passive immunization with antisera to S. mutans in the rhesus monkey. 2) Passive immunization with separated IgG, IgM and IgA from sera of immunized monkeys supports the concept that IgG, unlike IgA or IgM antibodies are protective. 3) The role of cell-mediated immunity has been explored by the use of transfer factor. This showed that protection against dental caries can be elicited by passive transfer of whole immune serum and cellular immunity, but not by cellular immunity or immune serum alone. 4) The results of active and passive immunization suggests that immuno-regulation of T and B cell interactions plays an important part in the effector mechanism of opsonization, phagocytosis and killing of S. mutans.

Animals↗
PubMed1978

Sequential changes in T and B lymphocyte responses to Herpes simplex virus in man.

Lymphocytes of seven patients with primary herpetic infection, twenty-three patients with recurrent herpes labialis and of nineteen control subjects were separated into T and B enriched cells by the use of nylon wool columns. In the absence of a herpetic infection the thymidine incorporation and macrophage migration inhibition responses to herpes simplex virus (HSV), Candida albicans and PPD, and the thymidine incorporation induced by PHA were functions of T cells. When a herpetic infection was present, the unfractionated lymphocyte response to HSV was increased, as measured by thymidine incorporation, but the T cell response was unchanged. However, T cells did show an increased response to HSV when prepared by elimination of cells forming rosettes with zymosan-complement. T cells of some patients were stimulated by contact with zymosan, and this correlated with the response to C. albicans. It is suggested that lymphocyte responses to HSV in man are mediated by T cells, but that these cells are specifically retained by nylon wool columns at the time of a herpetic infection. This may be associated with acquisition of an Fc receptor by the sensitized T cells.

B-Lymphocytes↗
PubMed1978

Immunological aspects of recurrent oral ulceration and Behçet's syndrome.

Immunological factors play in recurrent oral ulceration (ROU) and Behçet's syndrome (BS) but these cannot be distinguished by means of antibodies and cell-mediated immune responses to oral mucosal antigens. However, HLA markers seem to differentiate ROU from BS. Immune complexes have now been found in about 55% of patients with BS and fewer patients with ROU, so that the transition from the focal ROU to the multifocal BS might be mediated by immune complexes. Immunopathological studies have shown that a vasculitis is the essential lesion in BS and this might be secondary to immune complexes inducing complement activation and damage. It is not clear at present whether the increased levels of C9 and C-reactive protein are a manifestation of acute phase reactants. C9 could be involved in complement dependent lysis and C-reactive protein in modulating the cell-mediated immune responses by its effect on T lymphocytes. It seems that at least two types of damaging immune mechanisms have been identified; cell-mediated and immune complex induced reactions and these might account for the association between ROU and BS.

Antigen-Antibody Complex↗
PubMed1978

Passage of immunoglobulins from plasma to the oral cavity in rhesus monkeys.

The passage of immunoglobulin from plasma to the oral cavity was studied in rhesus monkeys. Immunoglobulins G, A and M were purified from pooled rhesus monkey serum, radiolabelled with 125I and injected intravenously into twelve monkeys. Sequential samples of oral fluids were taken over a 24 h period and were assayed for radioactivity. Radioactivity could be detected in crevicular fluid washings after 0.5 h in monkeys injected with IgG and IgA, and after 2 h in monkeys given IgM. Maximal levels were found after 4 h with each immunoglobulin. Radioactivity in parotid and mixed saliva could be detected in all animals after 30 min, reaching a maximal level after 4 h. Ultracentrifugation on sucrose density gradients revealed that most of the radioactivity in crevicular fluid washings was in the 7S zone in the animals given IgG and IgA, and in a 19S zone in animals given IgM. The radioactivity in partoid saliva did not represent intact immunoglobulin molecules, since all the activity was present in zones of low molecular weight in animals given IgG, IgA or IgM. In mixed saliva a small amount of radioactivity was found in the immunoglobulin zones. The results suggest that intact molecules of IgG, IgA and IgM can pass from plasma to the oral cavity via crevicular fluid, and could contribute to oral defence mechanisms particularly in the crevicular domain. The volume of crevicular fluid in the approximal space of deciduous molars of rhesus monkeys was estimated to be approximately 0.3 microliter.

Animals↗
PubMed1978

Sequential changes in cell-mediated immune responses to herpes simplex virus following primary herpetic infection in man.

During primary herpes simlex virus infections, sensitization to the virus was demonstrated at the time of presentation by lymphocyte blastogenesis. Recovery from infection coincided with development of the macrophage migration inhibition response, and it is suggested that macrophage activation by products of stimulated lymphocytes contributes to control of the infection.

Adolescent↗
PubMed1978

Circulating soluble immume complexes in recurrent oral ulceration and Behçet's syndrome.

Circulating IgG immune complexes were assayed by means of agglutination inhibition of IgG-coated latex particles to human IgG by rabbit IgM antibodies. Sera from thirty patients with Behçet's syndrome, thirty patients with recurrent oral ulcers and thirty healthy control subjects were analysed. The results showed raised levels of immune complexes in 60% of patients with Behçet's syndrome and 40% of patients with recurrent oral ulcers. There were significant differences in the levels of immune complexes between the neuro-ocular and arthritic types of Behçet's syndrome as compared with the muco-cutaneous type of Behçet's syndrome or recurrent oral ulceration. A close association was found between the disease activity and the amount of immune complexes. These results suggest that immune complexes may play a part in the transition from the epithelial involvement of mucosa or cutaneous tissues to the neuro-ocular and arthritic types of Behçet's syndrome. Another factor in tissue distribution might be the size of immune complexes, as multi-focal involvement of tissues in the neuro-ocular type of Behçet's syndrome is associated with a broad range of immune complexes from 3 X 10(5) to 3 X 10(6) daltons.

Antigen-Antibody Complex↗
PubMed1978

Damaged membrane fragments and immune complexes in the blood of patients with Behcet's syndrome.

Electron microscopic examination of centrifuged pellets of serum from patients with Behcet's syndrome and recurrent oral ulcers revealed the presence of a large number of membrane fragments. Some of these membranes showed numerous 10 nm holes that were identical to lesions produced by the action of complement. An attempt was made to correlate complement levels, antibodies and cellular immunity with the presence of the membrane fragments, without success. However, a significant correlation was found between the membranes and the IgG class of immune complexes. The finding of membrane fragments with complement-induced damage predominantly in the blood of patients with Behcet's syndrome, and the association with soluble immune complexes suggest that the latter may generate C5b-9 complexes which may bind to the surface of cells in result in cell lysis.

Adult↗
PubMed1977

Immune complexes in Behçet's syndrome and recurrent oral ulceration.

Seventeen patients with Behçet's syndrome, 11 with recurrent oral ulceration, and eight controls were studied in an investigation of the part possibly played by immune complexes in the transition from focal oral ulceration to the multifocal syndrome. Changes in the distribution of C3 within the first peak of Sephadex G200 fractionated plasma were found in nine of the 17 patients with Behçet's syndrome (55%), three of the 11 patients with recurrent oral ulcers, and none of eight controls. These findings provide indirect evidence that immune complexes are found in the plasma of these patients. Immune complexes were more common in patients with the neuro-ocular type of Behçet's syndrome than in those with the mucocutaneous type, and in those with herpetiform ulcers than in those with major or minor aphthous ulcers. Immune complexes were also associated with active disease. These findings support the hypothesis that the formation of immune complexes is an important step in the pathogenesis of Behçet's syndrome.

Antigen-Antibody Complex↗
PubMed1977

A sequential bacteriological and serological investigation of Rhesus monkeys immunised against dental caries with Streptococcus mutans.

In a serial investigation of the effects of immunisation with S. mutans in rhesus monkeys maintained on a "human" type of cariogenic diet, the numbers of S. mutans in cervical plaque, crevicular-fluid washings, fissures of teeth, and in saliva were lower in immunised animals than in sham-immunised controls. Immunisation also caused a delay in initial colonisation and a slowing of the rate of colonisation with S. mutans. These bacteriological changes were associated with a reduction in the smooth-surface-caries score. No relationship was found between the presence of S. sanguis and caries, but there was an inverse relationship between the proportions of S. mutans and S. sanguis isolated. Increased titres of complement-fixing, haemagglutinating and precipitating antibodies to S. mutans were found in the sera of immunised but not of control monkeys. A significant increase in salivary haemagglutinating antibodies was not detected. The results suggest that immunisation with S. mutans causes an increase in serum antibodies and a reduction in the number of S. mutans in the oral flora, and that these are associated with a reduction in dental caries.

Animals↗
PubMed1977

The effect of levamisole on gingival inflammation in man.

The effects of levamisole on gingival inflammation and on cell-mediated immunity were examined in patients with gingivitis and in subjects with clinically healthy gingiva. Treatment with levamisole promoted the development of gingivitis and aggravated the severity of established gingivitis, although the amount of bacterial plaque at the gingival margin was not significantly increased. This effect was short-lasting, as the gingival indices returned almost to base-line values by the end of the fifth month after treatment with levamisole. The development of gingivitis was associated with increased in vitro lymphocyte stimulation by antigens from oral bacteria. The role of cell-mediated immunity in the pathogenesis of gingival inflammation is discussed.

Actinomyces↗
PubMed1977

Sequential changes in cell-mediated immune responses to herpes simplex virus after recurrent herpetic infection in humans.

Lymphocyte responses to herpes simplex virus (HSV) were studied in 23 patients with recurrent herpes labialis and in 19 control subjects. Lymphocytes of seropositive, but not seronegative, controls responded to HSV by thymidine incorporation, and the supernatant fluids inhibited the migration of guinea pig macrophages. Lymphocytes from patients with a recurrent herpetic lesion responded to HSV by significantly greater thymidine incorporation than seropositive controls, but supernatants did not show an increased macrophage migration inhibition response. During the 28 days after the onset of a lesion, the thymidine incorporation to HSV fell to the level of the seropositive controls, and supernatants then induced an increased inhibition of macrophage migration. Lymphocyte responses to Candida albicans, purified protein derivative, or phytohemagglutinin did not fluctuate according to the presence of a lesion and did not differ from those of the controls. Lymphocyte responses to HSV were unaffected by culture in the presence of serum from seronegative or seropositive controls, or from patients with or without a herpetic lesion. It is suggested that in patients with recurrent herpes labialis a periodic defect of the migration inhibition response might have allowed the recurrent infection to develop, and that the increased thymidine incorporation stimulated by HSV in vitro is a result of antigenic stimulation from the lesion.

Adolescent↗