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Biomedical subjects

M Jalkanen

Publications and source records attributed to M Jalkanen.

At least 109 records · Page 6Linked to original sources
PubMed1984

Monoclonal antibodies to Bacteroides fragilis lipopolysaccharide.

Monoclonal antibodies (MoAbs) to the lipopolysaccharide (LPS) of Bacteroides fragilis were produced by immunizing mice before hybridization with bacterial outer membranes solubilized with Triton X-100. Nineteen stabile clones were established. They all produced antibodies that reacted more strongly with purified B. fragilis LPS than with crude sonicated antigen in an enzyme immunoassay. Four MoAbs were studied by immunoblotting and enzyme immunoassay inhibition. Immunoblotting confirmed that the target of the MoAbs was LPS. Marked and homogeneous staining occurred in the immunoblotting with both purified LPS and outer membranes in the molecular weight range of 8,000 to 27,000. In enzyme immunoassay inhibition, MoAbs reacted positively with 93 to 96% of B. fragilis strains, including prototype strains ATCC 23745 and NCTC 9343. Within the B. fragilis group, the MoAbs reacted positively with two of five B. ovatus strains and two to six of nine B. thetaiotaomicron strains. No marked cross-reactivity with other bacteria was observed. These results confirm earlier findings that the B. fragilis LPS contains an immunodominant antigenic determinant common to almost all B. fragilis isolates.

Animals↗
PubMed1983

Immune capacity of the chicken bursectomized at 60 hours of incubation: failure to produce immune, natural, and autoantibodies in spite of immunoglobulin production.

Chickens surgically bursectomized at 60 hr of incubation were immunized at the ages of 6, 7, 8, and 9 weeks with Escherichia coli lipopolysaccharide, levan, tetanus toxoid, and dinitrophenyl-bovine serum albumin. All antigens were given on each occasion. All embryonically bursectomized (BX) chickens had detectable concentrations of serum IgM, IgG, and IgA. On the whole, the IgG level was markedly decreased and the levels of IgM and IgA were normal. Concentrations of serum immunoglobulins did not change during immunization in the BX chickens. In spite of the production of serum immunoglobulins the BX chickens were unable to respond to the immunization by production of specific antibodies, whereas the control (CO) chickens produced good antibody response to each antigen used. The BX chickens also lacked both natural antibodies to phosphorylcholine, fecal bacteria, rabbit red blood cells (RRBC), and MHC antigens and autoantibodies to the liver, kidney, and thyroidea. Neither were any antibodies to the bursal structures observed. These results support the hypothesis that the bursal influence is not necessary for isotype switch, but is essential for the production of specific antibodies.

Animals↗
PubMed1983

Effect of Mycoplasma pulmonis infection on protein and glycosaminoglycan synthesis of cultured connective tissue cells.

Human synovial cells, fetal skin fibroblasts and rat granulation tissue fibroblasts were experimentally infected with Mycoplasma pulmonis, a species identified as a contamination of cell cultures, and studied for collagen, total protein and glycosaminoglycan synthesis. Hyaluronic acid and sulfated glycosaminoglycan synthesis were stimulated in cultures where the infection reduced cell density, while they were retarded in cultures which had proliferated into higher density than the controls. An extra polypeptide with molecular weight of 20 kD was seen in [35S]methionine-labelled cells. Media of rat granulation tissue cells showed a shift of a 39-42 kD polypeptide to 33-36 kD position in [35S]methionine and [3H]proline labellings. Other minor changes were also noticed. Collagen synthesis or procollagen conversion to collagen were, however, not altered.

Animals↗
PubMed1983

Wound fluids mediate granulation tissue growth phases.

The effects of exudates (wound fluids) from experimental granulation tissue on the synthesis of connective tissue components in fibroblast cultures were tested. The exudate from the early phase of granulation tissue (4 days after implantation) stimulated fibroblast proliferation and also the production of hyaluronic acid comparable to rat serum. On the contrary, the two later exudates (10 and 14 days after implantation) strongly inhibited fibroblast proliferation. These exudates also turned fibroblast glycosaminoglycan synthesis to more sulphate containing molecules. Collagen and protein synthesis were only slightly affected, the maximal collagen synthesis being obtained with the early phase wound fluid. The analysis of exudates and rat serum in sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed the clear similarity the exudates from the later growth stages produced some new proteins, which may regulate the altered metabolism of cultured fibroblasts.

Animals↗
PubMed1983

Immune capacity of the chicken bursectomized at 60 hr of incubation: surface immunoglobulin and B-L (La-like) antigen-bearing cells.

Chickens were surgically bursectomized at 60 hr of incubation before the bursal anlage appears. Completeness of the bursectomy was confirmed at autopsy at 10 wk of age. These embryonically bursectomized (Bx) chickens are known to produce immunoglobulins of IgM, IgG, and IgA classes, but so far no specific antibodies have been observed even after heavy immunization. Regarding the appearance of surface immunoglobulin positive (s-Ig+) cells, the most striking effect of bursectomy was observed in the frequency of s-IgG+ cells, which were markedly decreased in the spleen, peripheral blood, and thymus of the Bx birds when compared with the age-matched controls. s-IgM+ cells were significantly decreased in the peripheral blood and s-IgA+ cells in the spleen of the Bx birds. In contrast to these findings, s-Ig+ cells of all three classes were present in normal frequency in the bone marrow. Bursectomy had no effect on the total lymphocyte and other white cell counts in the peripheral blood. Likewise, no effect on the frequency of B-L (Ia-like) antigen-positive cells in different organs was observed.

Animals↗
PubMed1983

Immunological detection of proteins after isoelectric focusing in thin layer agarose gel: a specific application for the characterization of immunoglobulin diversity.

A simple and relatively rapid method was developed for the characterization of immunoglobulins from serum samples. After isoelectric focusing in a thin layer agarose gel proteins were transferred on to a nitrocellulose sheet by pressuring the focused gel against the sheet. A certain immunoglobulin class was stained on the sheet using alkaline phosphatase conjugated anti-immunoglobulins and the specific colour staining of the enzyme. The method allows the use of serum dilutions up to one thousand and conjugate dilutions up to two thousands. It was possible to strengthen the weak staining of antigens using a longer staining period and changing the substrate-dye solution without any background colorizing of the sheet. A specific application for the characterization of serum immunoglobulins of IgG class of a myeloma patient is presented.

Alkaline Phosphatase↗
PubMed1982

The effect of human dental plaque on bone resorption and hyaluronic acid synthesis in in-vitro cultures of fetal rat calvaria.

Dental bacterial plaque affects bone demineralization both in vivo and in vitro. Since hyaluronic acid may play a role in demineralization, calcium release into the media as a measure of bone resorption was correlated with the synthesis of [3H]-glucosamine-labelled macromolecules in bone culture. The synthesis of glycosaminoglycans was determined by both a Millipore method and by DEAE-cellulose chromatography. Addition of plaque extract to the culture media stimulated both the synthesis and release of hyaluronic acid to the culture media, while stimulating calcium release. Thus, the bone-demineralizing effect of dental plaque seems to be associated to the induced synthesis of hyaluronic acid.

Animals↗
PubMed1981

Connective tissue activating macromolecules in macrophage culture medium.

Fractions isolated by isoelectric focusing (pI values 4.6-5.3) from macrophage culture media stimulated fibroblast proliferation in vitro and increased the synthesis of sulfated glycosaminoglycans (sGAGs). Cationic fractions from macrophage culture media isolated by the same procedure (pI 10.2-10.4) enhanced secretion of collagen by fibroblasts. Two dimensional electrophoresis of non-fractionated 3H-lysine labeled macrophage media only showed incorporation of label into acidic proteins. The fractions from the pI area which increased DNA and GAG synthesis by fibroblast cultures contained three major labeled proteins with molecular weights of 15 K, 25 K and 135 K.

Animals↗
PubMed1980

A rapid assay to measure collagen synthesis in cell cultures.

Limited pepsin digestion and precipitation of resistant parts of proteins with perchloric acid on glass-fiber filters has been used as a rapid way to determine the radioactive collagen secreted into fibroblast culture media. The specificity of the pepsin cleavage was tested by digesting [14C]- or [3H]proline- and [3H]tyrosine-labeled procollagens. Radioactivities obtained with this method were comparable with those obtained with collagenase digestions or hydroxyproline determinations. Dialysis of the samples is avoided and the radioactive collagen can thus be determined from the small medium samples obtained from microtest plates. The method was used to localize a collagen synthesis-increasing factor in preparative isoelectric focusing of microphage culture media.

Animals↗
PubMed1980

Effect of five anti-inflammatory steroids on collagen and glycoaminoglycan synthessis in vitro.

The effect of five anti-inflammatory corticosteroids, i.e. hydrocortisone, hydrocortisone 17-butyrate, betamethasone 17-valerate, nicocortonide acetate and nicocortonide, on the synthesis of hyaluronic acid, sulphated glycosaminoglycans and collagen by cultured skin fibroblasts was studied. As inhibitors of all these parameters the steroids could be arranged in order hydrocortisone < hydrocortisone 17-butyrate < betamethasone 17-valerate, nicocortonide acetate and nicocortonide. The corticosteroid concentrations required for inhibition of hyaluronic acid were very low as compared to those required for inhibition of sulphated glycosaminoglycan and collagen synthesis.

Anti-Inflammatory Agents↗
PubMed1980

A longterm isotope renography follow-up of patients following pregnancy complicated by pre-eclampsia and hypertension.

61 patients were studied with the renography and urography during puerperium ten years ago and now again. The technique and analyses were identical. The results showed that some of these parameters (SV, K, and T 1/2) were either decreased or prolonged more than ten per cent during this period in nearly all cases. However, these changes occurred in both the normal and complicated groups without any correlation with the original diagnosis from the first study. Hypertension has developed in 10 per cent of the toxemic group.

Female↗