Deposits of immunoglobulins and complement factor C3 in human dental periapical inflammatory lesions

Abstract – Thirty-five human dental periapical lesions were studied by immunofluorescence technique using polyclonal anti-IgG (F(ab)₂), anti-IgM (F(ab)₂), anti-IgA (F(ab)₂), anti-IgE and anti-C3c as well as monoclonal anti-IgE. Prewashed ethanol-fixed specimens showed a great number of plasma cells staining for IgG. Cells containing IgA, IgM or IgE were also seen. Deposits of immunoglobulins and C3c suggestive of immune complexes were demonstrated using a double staining technique combining FITC-labeled immunoglobulins with TRITC-conjugated C3c. The complexes were located intracellularly in macrophages, as well as in vessel walls and in the basement membrane zone of proliferating epithelium. Immune complexes may be involved in the epithelial proliferation in those granulomas which lead to cyst formation. Monoclonal anti-IgE demonstrated plasma cells and mast cells, as well as intercellular IgE in epithelial strands of granulomas. The role of IgE in the epithelium is obscure. The study strongly indicates the involvement of hypersensitivity reactions type I and III in periapical inflammatory lesions.     

Enzyme histochemical characterization of mononuclear cells in human dental periapical chronic inflammatory lesions

Abstract – Cell infiltrates in sections of paraffin-embedded tissue of 36 human periapical inflammatory lesions (15 granulomas and 21 cysts) were examined by staining for acid α-naphthyl acetate esterase (ANAE). Thirty-four of the lesions showed ANAE reactive T lymphocytes, plasma cells and cells of the monocyte/macrophage cell line. Large granular lymphocytes (NK cells) could not be identified with certainty among the ANAE positive cells. Two specimens were free of ANAE reactive cells. Differential cell counts on sections from 15 lesions (7 granulomas and 8 cysts) showed that T lymphocytes were the predominating ANAE reactive cells (23%), followed by plasma cells (15%) and monocytes/macrophages (11%). 51% of the inflammatory cells were ANAE negative. There was no marked difference between the granulomas and the cysts. Inhibition with NaF (10–100 mM) gave a gradual reduction in number of ANAE positive cells, some macrophages being the only cells resistant to 100 mM NaF. The results suggest that both humoral and cellular immune reactions are likely to occur in periapical inflammatory lesions.     

Inhibition of bacterial growth by tetracycline-impregnated enamel and dentin

Tetracyclines can react with enamel and dentin to form relatively insoluble fluorescent compounds. The purpose of this study was to evaluate the possible antimicrobial effect of these reaction products on various microorganisms associated with human dental plaque and periodontal disease. Slabs of native dentin and enamel as well as demineralized dentin were immersed in aqueous solutions of tetracycline HC1, oxytetracycline HC1 and doxycycline HC1 for periods of 1 h or 24 h. Unimpregnated enamel and dentin slabs sterilized by gamma irradiation and specimens impregnated with phenoxymethylpenicillin calcium were used as controls. Test and control specimens were placed on agar plates seeded with B. cereus, C. ochraceus, S. sanguis, F. nucleatum, B. melaninogenicus or A. viscosus and were subsequently incubated aerobically or anaerobically at 37°C. With the exception of enamel impregnated for 1 h in a 0.01 mg/ml tetracycline solution, all test specimens caused growth inhibition zones, varying in size according to concentration of the drug, immersion period and bacterial species. The results indicate that tetracyclines react with enamel and dentin to form slightly soluble compounds with a pronounced antibacterial effect. In comparison, the antimicrobial effect of dentin treated with penicillin was small.     

MANNOSIDOSIS: CLINICAL, FINE-STRUCTURAL AND BIOCHEMICAL FINDINGS IN THREE CASES

Three boys, 4, 5, and 10 years old, with psycho-motor retardation, slightly gargoyle-like faces and recurrent infections were found to have vacuolized lymphocytes in the blood and bone marrow as well as diffuse skeletal alterations. Electron microscopy of liver biopsy specimens revealed vacuoles, presumably representing enlarged lysosomes engorged with storage material. The liver. a-mannosidase activity was somewhat low but not absent, while several other acid hydrolases in the liver had very high activities. The a-mannosidase activity was low also in white blood cells but not in plasma or urine. The liver and urine contained very high amounts of mannose-rich compounds. It is concluded that the patients suffer from man-nosidosis.     

Functional development of the visual system in normal and protein deprived rats II. Morphometric and biochemical studies on adult optic nerve

The optic nerve of normal (C) and protein deprived (PD) adult rats was examined by morphometry and biochemistry. The mean cross-sectional area of the optic nerve was reduced by 15% and the number of axons per unit area increased by 17% in the PD rats. Calibre spectrum analysis of axons revealed a reduction in median diameter from 0.49 μm in controls to 0.45 μm in PD rats. The number of axons with a diameter larger than r μm was reduced by 35% in PD rats. These reductions were probably due to a general reduction in size, since the calculated total number of axons in the optic nerve was almost identical in C and PD rats (126 times 10³ and 124 times 10³, respectively). The increased packing density of axons in the nerve was not only due to thinner axons. The biochemical measurements showed a marked reduction in myelin basic protein in the optic nerves of PD rats, without an alteration in the composition of the total protein. This confirms the persistant hypomyelination which has been reported previously in other malnutrition models. The possible relations between the structural and biochemical changes affecting optic nerve fibres and physiological findings on cortical visual evoked response and on optic nerve in vitro in PD rats are discussed.     

EARLY DETECTION OF PRESCHOOL HEALTH PROBLEMS—ROLE OF PERINATAL RISK FACTORS

Abstract. To evaluate a perinatal riskgrouping system, 1262 4-year-old children went through a comprehensive health examination. A total of 41.5% of the newborns were included in the wide criteria of risk, which were more common among boys and among children of the youngest and oldest mothers. Among the 4-year-old, the frequency of significant physical health problem was 15.8%, including 10.1% visual disturbances and 2% neurological disorders. In some combinations of riskgroups and later health problems there were statistically significant correlations, e.g. regarding prematurity and cerebral irritation vs. cerebral palsy, hut not sufficient to serve its purpose as a screening instrument. Even the accumulation of especially serious events in the perinatal period gave no clue to later neurological disorders. The addition of low socioeconomic status as a perinatal risk did not influence the outcome either. The reasons for the weak correlation between perinatal risk factors and later outcome of health disorders and handicaps are discussed, and it is concluded that to detect children with health problems, there seems to he no acceptable alternative to a comprehensive health surveillance as part of a general health service programme of all children, including clinical examinations and screening procedures by well trained personnel.     

Oligosaccharides obtained by partial hydrolysis of lipopolysaccharides from Leptotrichia buccalis

Lipopolysaccharides (LPS) from Leptotrichia buccalis, strains LI 1, ATCG 14201 and ATCG 19616 were partially degraded with 1 % acetic acid. The acid soluble polysaccharides were subjected to gel filtration. These experiments showed that the carbohydrate moiety of LPS from ATGC 14201 and ATCG 19616 were similar, consisting ofa core oligosaccharide unsubstituted by 0-side chains containing galactose, glucose and D-glycero-D-manno-heptose as neutral sugars. The core analogous fraction isolated from LI 1 LPS contained the same three neutral sugars, but in different ratios.     

Intimacy of the neuroeffector junction and resistance to α-adrenoceptor-blockade of the neurogenic contractile response in vasa deferentia from guinea pig and rat

The effect of phentolamine on the neurogenic contractile response in vasa deferentia from rat and guniea pig was studied during Wallerian degeneration. This response was also investigated after partial denervation (surgery or chemical sympathectomy by guanethidine treatment) in vasa deferentia from guinea pig. During Wallerian degeneration the response showed a gradual increase in sensitivity to phentolamine and was abolished in the late stages. The neurogenic contractile response of the partially denervated vas deferens was blocked by low concentrations of phentolamine. It is concluded that decreased intimacy of the neuroeffector junctions leads to increased susceptibility to α-adrenoceptor blockade of the contractile response to nerve stimulation. It is further concluded that the motortransmission in the vas deferens is essentially adrenergic. The resistance to α-adrenoceptor blockade of the initial phase of the contractile response to nerve stimulation of intact vasa deferentia from guinea pig and rat might well be explained by the “proximity theory” of Dale & Gaddum although participation of supplementary mediators cannot be excluded.