Increase in anti-astrocyte antibodies in the serum of guinea pigs during active stages of experimental autoimmune encephalomyelitis.

From previous studies on the induction and treatment of experimental autoimmune encephalomyelitis (EAE) in guinea pigs and mice, antibodies have been implicated during both demyelination and remyelination. In the present study, sera from guinea pigs with acute, chronic and myelin basic protein/galactocerebroside (MBP/GC)-treated chronic EAE were evaluated for the presence of anti-glial cell antibodies by immunocytochemical techniques. Antigen specificity was confirmed by enzyme-linked immunosorbent assay (ELISA) and Western blotting. The majority of sera from acute and chronic active EAE animals displayed intense labelling of astrocytes and only weak staining of oligodendrocytes when tested on sections of normal guinea pig brain tissue. In contrast, sera from animals with chronic EAE treated with MBP/GC gave strong labelling of oligodendrocytes and only minor staining of astrocytes. By immunoblotting, astrocyte staining was shown to be due to the presence of antiglial fibrillary acidic protein (GFAP) antibodies. The intense oligodendrocyte staining observed in sections reacted with sera from MBP/GC-treated guinea pigs corresponded well with high titers of serum anti-GC and anti-MBP antibodies measured by an ELISA. It was concluded that the presence of antibodies against astrocytes was possibly related to astrocytic antigens within the disease-inducing emulsion, at least during the initial phases of EAE, and not to their release from the central nervous system of affected animals.

Immunoglobulins in human dental caries.

The penetration and complement fixation of sIgA, IgM and IgG were studied in advanced human dental caries with double-staining immunofluorescence technique. Immunoglobulins were found in dental plaque and in the superficial layers of the lesions which were exposed to saliva. sIgA was the most frequent, followed by IgG and IgM. IgG had the greatest capacity for penetration into the lesions, followed by IgM and sIgA. IgM was most frequently found in association with complement C3.

Experimental pulpal Arthus allergy.

Rabbits sensitized systemically to ovalbumin displayed skin reactions of the Arthur type and high titers of circulating antibodies. Their incisor pulp was removed at intervals after local challenge with 0.001 ml of 1 percent ovalbumin. Acute inflammatory lesions were demonstrated in the pulp by optical and electron microscopy. Immunofluorescence revealed massive accumulations of antigen-antibody complexes in the lesions, confirming the presence of an Arthur type of allergy.

Identification of bacteria in immunopathologic mechanisms of human dental pulp.

Serial frozen sections from human dental pulp were used for the identification of oral bacteria in immunopathologic mechanisms. Sera raised against Actinomyces viscosus, A. naeslundii, Bacteroides gingivalis, and B. melaninogenicus ss. intermedius, commercial sera against human immunoglobulins, complement, and monoclonal antibodies against human T cells were used in a double-staining immunofluorescence technique. Sections of dental pulp from normal teeth showed no penetration of bacteria or bacterial antigens and no signs of inflammation. A unique aspect of the present study was the demonstration that penetrating bacteria and bacterial antigens in the pulp of involved teeth were always associated with antibodies and frequently also with complement. A. viscosus has been found most frequently in complement-fixing immune complexes followed by B. gingivalis. A. naeslundii and B. melaninogenicus ss. intermedius were found only in complexes with antibodies. The involvement of plasma cells and T cells was also demonstrated. In the dental pulps of diseased teeth, cytotoxic and Arthus type immunopathologic reactions occurred.

[Induction of autoallergic pulpitis in rabbit (author's transl)]. / Induction d'une pulpite autoallergique chez le lapin.

Six male rabbits were injected on days 0, 6 and 12, subcutaneously, intraperitoneally and subcutaneously with 0.5 ml/kg of a 20% suspension of homologous dental pulp, in complete Freund's adjuvant. Six controls received complete Freund's adjuvant only. Leukocytes were counted regularly. A skin test was performed on day 18. On day 22, a dental test was performed to study the macrophage migration inhibition "in vivo". On day 23, the animals were killed, the teeth and skin were analysed histologically. The following results were observed in the experimental group: 1) inhibition of growth, 2) leukocytosis and eosinophilia, 3) a positive skin test with a strong lymphocytic infiltration, 4) an inhibition of "macrophage migration", 5) pulpal lesions, numbering 1 to 6 per rabbit, with lymphocytic plasmocytic and eosinophilic perivascular infiltration. These results indicate an experimental auto-allergic pulpitis. The mechanisms of human pulpitis ought to be reexamined in the light of these observations.

Invasion of bacteria in enamel carious lesions.

A review of recent findings concerning enamel carious lesions is presented. This lesion represents the initial phase of dental caries and is characterized by a demineralization of the subsurface enamel caused by acids of the plaque bacteria. Streptococcus mutans has been described as the etiologic agent of the dental caries and the most acidogenic plaque bacteria. Morphological studies have shown an invasion of microorganisms inside the enamel carious lesion. Unfortunately, several technical problems are associated with such studies. The identification of the invading bacteria has not yet been achieved. The future identification of bacteria inside the subsurface enamel lesions will represent an important step in the prevention of the carious progression.

[Allergies and dental pulp (author's transl)]. / Allergies et pulpe dentaire.

A review of the articles dealing with allergy in the dental pulp is oppered. The dental pulp--furthermore when inflamed--showes antigens, lymphocyetes and plasmocytes, antibodies (IgG, IgA and IgE), mast-cells, histamine and possibly C3. However an hypersensitivity or allergy of immediate type elicited by circulating antibodies has never been demonstrated. In another way, two types of allergies of cellular type have been described in the dental pulp: graft rejection and contact hypersensitivity. Autoimmunity has also just been described.

Allergies of the dental pulp.

A review of publications relating to the allergies of the dental pulp is presented. The pulp--especially when inflamed--contains antigens, lymphocytes, plasmocytes, IgG, IgM, IgA, and IgE antibodies, mast cells, histamine, and possibly C3. However, no antibody-mediated allergy (hypersensitivity) of the pulp has yet been demonstrated. On the other hand, two types of cell-mediated allergy--the graft-rejection reaction and contact hypersensitivity--have been reported, as well as autoimmunity.

Rodent incisor pulp, isolation and sectioning.

Experimental technics are described for a quick isolation of the dental incisor pulp in rodents, and for the wrapping of the pulp in a sheet of guinea pig muscle as a prerequisit for cryostat sectioning.

Identification of bacteria in association with immune components in human carious dentin.

Actinomyces viscosus, A. naselundii, Streptococcus mutans serotype "c" and S. mutans serotype "d/g" were identified in human carious dentin using histological and immunofluorescent techniques. A. viscosus was most frequently found in association with patient's immunoglobulins and complement, followed by S. mutans serotype "d/g", S. mutans serotype "c", and A. naeslundii.

[Hartnup disease (report of 2 cases in one family)]. / Hartnupova bolest (prikaz dva bolesnika is jedne porodice).

INTRODUCTION: The Hartnup mutation affects the amino acid transport system of the intestine and kidney used by a large group of neutral amino acids (monoamino-monocarboxylic acids) resulting in a characteristic pattern of neutral aminoaciduria [2, 5, 6]. METHODS AND PATIENTS: In this research clinical and neurological methods and a great number of laboratory tests were used. Patient 1. A 16-year-old girl, born in 1972, was a full-term newborn. Her psychomotor development was normal. She is the eldest of three children in the family. Till the age of 10 the girl was healthy, except for the mild skin disorders on uncovered parts of the body, face and hands, occurring in springtime almost every year. She had had two exacerbations of the disease. The first exacerbation lasted between the end of April and August 22, 1982. The second began in the middle of November 1987 and finished on May 31, 1988. A changeable and severe clinical feature in this girl was characterized by polymorphic, transient mainly cerebral symptoms, papilloedema with peripapillary haemorrhage and pellagra-like skin rash. At the beginning of the disease the left spastic haemiplegia with bilateral Babinski's reflex and diffuse brain oedema were observed. Signs of the upper motor neurone lesion and myoclonic jerks of limbs and face were most persistent during the first and second exacerbation of the disease. Dysinhibition phenomenon: mandibular, snout and palmomental reflexes were sometimes positive. Mental states at the time of hospitalization were changed and characterized by bradypsychic, torpid, disoriented in time and confused at the beginning of the disease. She had severe psychotic episodes during the second relapse of the disease. The symptoms and signs of the disease as well as pellagra-like skin rash resolved with nicotinamide therapy. Patient 2. A 38-year-old man; clinically healthy, with no skin lesions. A gross aminoaciduria was found in this case. However, the amino acids pattern was atypical. DISCUSSION: This new, rare disease was described [1] with complex and variable clinical symptoms, intermittent course, permanent aminoaciduria and other biochemical features. In our symptomatic patient diagnosis of Hartnup disease was established during the second exacerbation of the disease. CONCLUSION: Two cases of Hartnup disease, one symptomatic and one asymptomatic, were diagnosed in a five member family. A child in this family died at the age of 3.5 probably from Hartnup disease.

Mechanisms of HIV-associated immunosuppression.

HIV antigens were identified in PBL obtained from HIV-positive patients, using IF and IEM. Studies of the phenotype of HIV-containing lymphocytes showed that OKT4+ cells were the principal target of the virus. Approximately 5% of infected cells were multinucleated. Almost all infected and about 30% of uninfected PBL displayed Ab-C3 complexes on the cell surfaces. Sera from HIV-positive patients contained Ab reacting with cell membranes and intracellular structures of PBL from normal subjects, as demonstrated by IEM. The presence of Ig-C3 complexes on a high percentage of HIV-positive- or negative-PBL suggests that the Ab-C-mediated lympholysis may represent a major mechanism of lymphatic tissue destruction in HIV-infected patients.

Thymic epithelium in AIDS. An immunohistologic study.

The authors investigated by immunofluorescence the thymic epithelium from AIDS patients, using several structural and functional markers of this tissue. In AIDS thymus, the epithelial reticular pattern was lost; and instead, clusters of round or spindle-shaped cells (assessed by their keratin content) were found. In addition, regions of epithelial necrosis, with loss of cell limits, were frequently observed. Thymulin content was decreased, and a partial loss of differentiation antigens of the thymic epithelium was also detected. The authors showed the presence of immunoglobulins and elements of the complement system directly bound to AIDS thymic epithelium, but not in any of the controls studied, including thymuses from patients who died after a long period of agony. These data suggest that the thymic epithelium can be included among the target tissues in AIDS, possibly by an indirect mechanism of autoimmune destruction.

Detection of HTLV-III/LAV antigens in peripheral blood lymphocytes from patients with AIDS.

HTLV-III was searched for in frozen sections of peripheral blood lymphocytes obtained from AIDS patients by an immunofluorescence technique. Human IgG against HTLV-III/LAV and monoclonal antibodies against HTLV-III/LAV P 24 antigen, yielded a strong cytoplasmic fluorescence in frozen sections of the lymphocytes. Some cells containing HTLV-III antigens displayed multinucleated giant forms. They also reacted with monoclonal antibodies against helper/inducer T-cells (OKT4+), as demonstrated by direct double staining immunofluorescence. Similarly, complexes of immunoglobulins and C3 component of complement were also detected on HTLV-III/LAV Ag expressing lymphocytes. Immunofluorescence study of frozen sections of peripheral blood lymphocytes appeared to be a simple, fast and reliable method for detection of HTLV-III/LAV Ag in AIDS patients.

Pathogenicity of HIV in lymphatic organs of patients with AIDS.

HIV antigens were searched for in the thymus, lymph nodes, bone marrow, and spleen of AIDS patients, by means of immunofluorescence technique. Human IgG against HIV and monoclonal antibodies against viral gag P24 protein yielded strong cytoplasmic fluorescence of cells in sections of the thymus, lymph nodes and spleen. Some cells containing HIV antigens were morphologically multinucleated giant cells. They reacted with monoclonal antibodies against helper/inducer T-cells (OKT4+), and were complexed with antibody or with complement as demonstrated by double-staining immunofluorescence technique. A large number of inflammatory cells infiltrated the thymus in areas containing cells expressing HIV antigens. These studies demonstrated an association of HIV virus with cytopathic and immunopathogenic reactions in lymphatic organs of AIDS patients, and are consistent with previous results, as well as indicative of a primary aetiologic role for the virus.

Thymic epithelial cell transplantation in patients with acquired immunodeficiency syndrome. Evidence for infection by HIV-I of newly differentiated T cells at the site of transplantation.

From October 1983 to July 1984, 11 adult AIDS patients have received single or repeated thymic grafts. All have had opportunistic infections and 3 also had Kaposi's sarcoma. Thymic tissue from infants undergoing cardiac surgery was cultured to provide a thymocyte- and fibroblast-free epithelial cell inoculum. 18-21 days post-explantation, cells and explants were injected intraperitoneally, intramuscularly or intrahepatically. Transplants were well tolerated in all cases. In 7 cases liver biopsy was performed at the time of grafting and 2 months later. Ten patients have died after a mean survival time following transplantation of 8.7 months while 1 patient was lost to follow up. Clinical improvement and absence of new opportunistic infections were apparent for 4 months following transplantation. Partial immunoreconstitution was evidenced by an increase in peripheral blood lymphocytes (8 of 10 cases) and lymphocyte subsets (7 of 10 cases) as well as by presence of T4 and T8 positive cells in the liver (5 of 7 cases). In 5 of 7 patients, double-staining immunofluorescence showed that HIV-I antigens were present in T4-phenotype cells, at the site of the graft, 2 months after grafting, but were not detected in the liver at the time of grafting. Transient immunoreconstitution, therefore, maybe related to destruction of newly differentiated T lymphocytes.