Search PubMed⌕ Search

Biomedical subjects

J Carlsson

Publications and source records attributed to J Carlsson.

At least 217 records · Page 12Linked to original sources
PubMed1990

Effects of 131I-EGF on cultured human glioma cells.

Malignant glioma cells often have more epidermal growth factor (EGF) receptors than normal cells and targeting of toxic substances to the receptor might therefore be an attractive therapeutical approach. Radiation effects were analysed on human glioma cells growing as monolayers after exposure to 131I-EGF. Unspecific effects were analysed with 131I-BSA or after presaturation with nonradioactive EGF. The radiation effects were compared to the effects obtained by external 60Co gamma irradiation. Administration of the highest radioactive concentrations, 0.2-0.5 MBq/ml in the culture medium, corresponded, after 20 min incubation, to a binding of about 1.0-2.5 dpm/cell. Such an exposure to 131I decays gave effects on cell survival corresponding to about 2.5 Gy of external gamma irradiation. Somewhat less than half of this effect came from the specific bound radioactivity and the rest from nonbound radioactivity. When administrating lower concentrations of radioactivity both the binding and the radiation effects were smaller. The observations showed that it is possible to inactivate cell-proliferation of glioma cells with specific bound 131I-EGF. The possibilities to fractionate the treatments and of binding also other toxic agents than 131I to the EGF receptor are discussed.

Cell Line↗
PubMed1990

Plasmodium falciparum: differential parasite reactivity of rabbit antibodies to repeated sequences in the antigen Pf155/RESA.

For selection of immunogens capable of inducing high levels of antibodies reactive with the Plasmodium falciparum antigen Pf155/RESA, rabbits were immunized with synthetic peptides corresponding to sequences based on the repeat subunits EENVEHDA and (EENV)2 from the C-terminus of this antigen. The antibodies obtained were analyzed with regard to binding to synthetic peptides in ELISA and to reactivity with parasite antigens by immunofluorescence or immunoblotting. All antisera reacted with both the peptides EENVEHDA and (EENV)2 as well as with Pf155/RESA. Antibody fractions specific for each of the two peptides were prepared by affinity chromatography on insolubilized peptides. Strong reactivity with antigens in the membrane of erythrocytes infected with early stages of the parasite as well as reactivity with Pf155/RESA in immunoblotting correlated with reactivity of antibody with (EENV)2. Antibody preparations reactive with EENVEHDA and depleted of (EENV)2 reactivity showed only a weak reactivity with Pf155/RESA but reacted also with P. falciparum polypeptides of 250, 210, and 88 kDa. In immunofluorescence, these antibodies stained mainly the intraerythrocytic parasite. Both EENVEHDA- and (EENV)2-specific antibodies inhibited merozoite reinvasion in P. falciparum in vitro cultures, the latter antibodies being the most efficient. This study defines the specificity and cross-reactivity with other P. falciparum antigens of antibodies to the C-terminal repeats of Pf155/RESA.

Amino Acid Sequence↗
PubMed1990

Effects of prostaglandin and leukotriene inhibitors on the growth of human glioma spheroids.

Established cell-lines of human glioma origin were cultured as multicellular spheroids or as monolayers. Volume growth and 3H-thymidine labelling were analysed for the spheroids after continuous exposure to drugs interfering with the release of arachidonic acid and the production of prostaglandins and leukotrienes. Comparative measurements were made on monolayer cultures. The cyclo-oxygenase inhibitor indomethacin enhanced growth at intermediate concentrations (0.5-5.0 micrograms/ml) but reduced growth at 50 micrograms/ml. The dual cyclo-oxygenase and lipoxygenase inhibitor ketoprofen had a significant inhibitory effect on growth and cell proliferation of spheroids at high concentration (50 micrograms/ml). The weak lipoxygenase inhibitor NDGA (quinone-form) decreased growth whereas the strong lipoxygenase inhibitor NDGA (hydroquinone-form) did not reduce growth rate but significantly decreased cell proliferation. Quinacrine reduced the spheroid growth rate although dexamethasone had no effects. Thus, inhibitors of the arachidonic acid cascade had growth inhibitory effects in the spheroid tumour model as well as in cells cultured as monolayers.

Arachidonic Acids↗
PubMed1990

Effects of the 5-lipoxygenase inhibitors AA-863 and U-60,257 on human glioma cell lines.

The effects of two specific 5-lipoxygenase inhibitors AA-863 and U-60,257 (piriprost) on the growth of two human glioma cell lines, U-343 MGa and U-251 MG were investigated. Both monolayer cultured cells and spheroids were studied. The results of the monolayer studies showed potent and dose dependent inhibitory effects on the proliferation of glioma cells (IC50/one week treatment/of AA-863: 9.0 microM, IC50 of U-60,257: 40.0 microM). The experiments made on the tumor spheroids suggested an inhibitory effect on proliferation and volume growth already at lower doses (AA-863: 0.4-2.0 microM, U-60,257: 1.0-5.0 microM), a dose range where effects were not found in monolayers. At higher doses (AA-863: 10.0-30.0 microM, U-60,257: 30.0-90.0 microM) the experiments with spheroids failed to demonstrate a further inhibitory effect on spheroid volume, probably attributed to phenomena such as swelling of cells, dissociation of spheroid structure and development of necrosis. The clearly dose dependent inhibitory effect on the proliferation of human glioma cells in monolayer culture and the inhibitory effects on spheroid growth with these specific inhibitors indicate a role for lipoxygenase products in the growth of gliomas.

Arachidonate Lipoxygenases↗
PubMed1990

Oculomotor disturbances in patients with tension headache treated with acupuncture or physiotherapy.

Forty-eight female patients with chronic tension headache were randomized into two treatment groups--acupuncture and physiotherapy. The patients were examined using oculomotor tests. Intensity of the headache and tenderness of the trapezius muscles were assessed in accordance with graded scales. The mean velocity gain for smooth pursuit eye movements improved for all target velocities both in the physiotherapy group and in the acupuncture group. The latency was reduced for all three gaze angles in the physiotherapy group while no improvement occurred in the acupuncture group. There was a reduction of headache intensity in both groups while tenderness of the trapezius muscles was reduced in the physiotherapy group but unchanged in the acupuncture group. A significant correlation was found between average of the mean velocity gain and tenderness of the trapezius muscles.

Acupuncture Therapy↗
PubMed1990

Muscle tenderness in tension headache treated with acupuncture or physiotherapy.

Sixty-two female patients with chronic tension headache were randomized into two treatment groups--acupuncture and physiotherapy. The intensity of headache, muscle tenderness and neck mobility was assessed before and after treatment. Thirty healthy women were used for comparison. Before treatment it was found that muscle tenderness was increased and neck rotation was reduced in the patient group compared with controls. There was a significant correlation between the intensity of headache and muscle tenderness. After treatment, the intensity of headache and muscle tenderness were reduced in both treatment groups. The headache was more improved in the physiotherapy group, and there was a marked reduction in the intake of analgesics. The tenderness was reduced in all muscles tested in the physiotherapy group but only in some of the muscles after acupuncture. The limitation of neck rotation was not influenced by either treatment.

Acupuncture Therapy↗
PubMed1990

Production of volatile sulfur compounds by various Fusobacterium species.

In 12 species of Fusobacterium the following characteristics were studied; the desulfhydration of L-cysteine and L-methionine by resting cell suspensions, the formation of alpha-keto-acids from L-cysteine, D-cysteine and L-methionine by cell extracts, and the formation of hydrogen sulfide from L-cysteine, D-cysteine and L-cysteine by cell extracts separated by polyacrylamide gel electrophoresis. Multiple forms of L-cysteine desulfhydrase activity were found in most of the species. In some of them also D-cysteine desulfhydrase activity was demonstrated. Seven of the species had high L-methionine gamma-lyase activity. L-cysteine activity was present in 5 of the species.

Carbon-Sulfur Lyases↗
PubMed1990

The formation of hydrogen sulfide and methyl mercaptan by oral bacteria.

The capacity to form volatile sulfur compounds was tested in bacteria isolated from subgingival microbiotas and in a representative number of reference strains. A majority of the 75 tested oral bacterial species and 7 unnamed bacterial taxa formed significant amounts of hydrogen sulfide from L-cysteine. The most active bacteria were found in the genera Peptostreptococcus, Eubacterium, Selenomonas, Centipeda, Bacteroides and Fusobacterium. Methyl mercaptan from L-methionine was formed by some members of the genera Fusobacterium, Bacteroides, Porphyromonas and Eubacterium. When incubated in serum for 7 d, the most potent producers of hydrogen sulfide were Treponema denticola and the black-pigmented species, Bacteroides intermedius, Bacteroides loescheii, Porphyromonas endodontalis and Porphyromonas gingivalis. P. endodontalis and P. gingivalis also produced significant amounts of methyl mercaptan in serum. No other volatile sulfur compound was detected in serum or in the presence of L-cysteine and L-methionine. These findings significantly increase the list of oral bacteria known to produce volatile sulfur compounds.

Bacteroides↗
PubMed1990

Health status in patients with tension headache treated with acupuncture or physiotherapy.

Sixty-two female patients with chronic tension headache were randomly divided into two treatment groups--acupuncture and physiotherapy. Their overall function (Sickness Impact Profile), and mental well-being (Mood Adjective Check List) and the intensity and frequency of headache were assessed before and after treatment. Before treatment the patients showed significantly more dysfunction and less positive mental well-being than a general population sample. Both treatment groups improved in overall function, the physiotherapy group somewhat more. The mental well-being increased only in the physiotherapy group. The intensity and frequency of headache was significantly reduced in both the physiotherapy group and the acupuncture group. The intensity of headache was significantly more improved in the physiotherapy group. The improvement of headache intensity persisted unchanged 7-12 months after treatment.

Acupuncture Analgesia↗
PubMed1990

Periodontitis in the primary dentition associated with Actinobacillus actinomycetemcomitans infection and leukocyte dysfunction. A 3 1/2 year follow-up.

2 siblings, aged 5 years (girl) and 7 years (boy), with periodontitis in the primary dentition were studied. Actinobacillus actinomycetemcomitans was isolated from the gingival pockets of both children. The titers of IgG antibodies against A. actinomycetemcomitans were elevated, and the polymorphonuclear leukocytes had a decreased capacity to ingest IgG-coated latex particles. Other functions of the polymorphonuclear leukocytes were normal. After antibiotic therapy and for the 7-year-old boy, debridement of the gingival pockets A. actinomycetemcomitans was no longer detectable in the gingival pockets, and the phagocytic capacity of the polymorphonuclear leukocytes was normalized. After 2 1/2 years, A. actinomycetemcomitans was found again in the gingival pockets of the boy, and once more his polymorphonuclear leukocytes had a decreased capacity to ingest IgG-coated latex particles. The antibiotic therapy was repeated and 6 months later, the number of A. actinomycetemcomitans was very low and the phagocytic capacity of the polymorphonuclear leukocytes was back to normal. This case report suggests that A. actinomycetemcomitans may be involved in the etiology of periodontitis in the primary dentition, possibly by triggering a phagocytic dysfunction of polymorphonuclear leukocytes.

Actinobacillus Infections↗
PubMed1989

Reactivity of the human monoclonal antibody 33G2 with repeated sequences of three distinct Plasmodium falciparum antigens.

The human mAb 33G2 has high capacity to inhibit in vitro invasion of erythrocytes by Plasmodium falciparum merozoites and, thus, is of special interest with regard to protective immunity against the parasite. In order to obtain more information about asexual blood stage Ag of P. falciparum that are seen by this antibody, material from synchronized P. falciparum cultures was studied by immunofluorescence, immunoelectron microscopy, and immunoblotting. Reactivity was mainly confined to the membrane of infected erythrocytes. Soon after merozoite invasion the antibody stained the erythrocyte membrane. This membrane-associated staining faded during intracellular development of the parasites. Beginning about 18 h after invasion, a dotted pattern appeared which increased in strength with time and persisted to schizont rupture. Pf155/RESA was the major Ag recognized in immunoblots of parasites collected throughout the entire erythrocytic cycle, although other polypeptides also bound the antibody. Among these was a 260-kDa polypeptide found in late trophozoites and schizonts. The specificity of the antibody was analyzed with synthetic peptides corresponding to repeated sequences in the P. falciparum Ag Pf155/RESA, Pf11.1, and Ag332. Synthetic peptides related to Ag332 were the most efficient inhibitors of antibody binding in immunofluorescence studies and cell ELISA. A beta-galactosidase-Ag332 fusion protein was also efficient in reversing reinvasion inhibition caused by 33G2. These results define a family of cross-reactive P. falciparum Ag recognized by mAb 33G2 and suggest that Ag332 was its original target.

Amino Acid Sequence↗
PubMed1989

Homogeneous penetration but heterogeneous binding of antibodies to carcinoembryonic antigen in human colon carcinoma HT-29 spheroids.

The monoclonal antibodies 38S1, directed against the carcinoembryonic antigen (CEA), were tested for penetration and binding in human colon carcinoma HT-29 spheroids. Penetration was studied with a method which has not previously been used in immunological investigations. The method, which allows unbound substances to be visualized, is based on freeze drying, vapour fixation, dry sectioning and dry autoradiography. The antibodies penetrated easily and all parts of the HT-29 spheroids seemed to be reached within 15 min. The penetration was even faster than in control glioma U-118MG spheroids that did not express CEA. Binding of the 38S1 antibodies was demonstrated after processing with conventional histology and autoradiography. The binding in the HT-29 spheroids was, after a 1-h incubation period, extremely heterogeneous and occurred mainly in the peripheral parts. More cells were binding the antibodies after 8-h and 32-h incubations and these cells were arranged in peripheral clusters. No binding at all was seen in the CEA-negative glioma spheroids. The distribution of CEA antigens in monolayers and in frozen sections of spheroids of HT-29 cells was analysed with immunohistochemical staining using polyclonal CEA antibodies. The CEA antigens were heterogeneously distributed in both spheroids and monolayers and were as heterogenous as the binding of the monoclonal antibodies in the living spheroids. Thus, the heterogeneous binding in the living spheroids was not due to penetration barriers, but instead to the heterogeneity in the CEA antigen expression.

Adenocarcinoma↗
PubMed1989

The capacity of subgingival microbiotas to produce volatile sulfur compounds in human serum.

Hydrogen sulfide is formed by the subgingival microbiotas of periodontal pockets. The capacity of these microbiotas to form various volatile sulfur compounds in human serum was studied. Bacterial samples from nine deep periodontal pockets were incubated for 7 days in human serum and the amounts of volatile sulfur compounds and the degradation of serum proteins were determined. Hydrogen sulfide was the predominant volatile sulfur compound, but also methyl mercaptan was formed in significant amounts. Only traces of dimethyl sulfide and dimethyl disulfide were detected. There was an extensive degradation of the serum proteins. In most of the reaction mixtures hydrogen sulfide reached highly toxic levels.

Bacteria↗
PubMed1989

Activity of polymorphonuclear leukocytes in the presence of sulfide.

Polymorphonuclear leukocytes (PMN) isolated from human blood were exposed to various levels of hydrogen sulfide. The effect on respiratory burst, myeloperoxidase activity, and capacity to phagocytose and kill bacteria were studied. A 1-h exposure of the PMN to 1 mM sulfide did not decrease their myeloperoxidase activity or their capacity to initiate a respiratory burst. Actually the products of the respiratory burst rapidly oxidized sulfide. The phagocytosis and killing of bacteria in the presence of 1 mM sulfide was only decreased to a minor extent. Myeloperoxidase in cell extract was, however, almost completely inhibited by 1 microM sulfide. These results indicate that hydrogen sulfide does not easily permeate PMN. PMN may be able to function in infected sites with high sulfide levels such as in the gingival pockets of periodontal disease. In the oxygenated areas of these sites the PMN may actually help in the detoxification of sulfide.

Blood Bactericidal Activity↗
PubMed1989

Influence of ionizing radiation on oxygen profiles in different types of multicellular spheroids.

Human glioma (U-118 MG and U-138 MG), human colorectal adenocarcinoma (HT-29), human thyroid carcinoma (HTh 7), and hamster embryonic lung (V79-379A) spheroids were irradiated with either single doses of 16 or 40 Gy or fractionated doses of eight times 5 Gy. Oxygen profiles in the spheroids were measured with microelectrodes at different times following irradiation, and these profiles were then compared with the oxygen profiles measured in parallel cultured nonirradiated spheroids. No significant radiation-induced changes in the oxygen profiles were seen in any of the spheroids within the first few days after irradiation. The glioma spheroids did not show any significant increase in oxygen tension even after longer times; however, they were growth inhibited, and the number of S-phase cells was strongly suppressed. Increases in oxygen tension did occur in the HT-29 and V79-379A spheroids but only appeared more than a week after irradiation, when degeneration had started. Histological changes and decrease in diameter were seen in the spheroids that started to degenerate about 5 days after irradiation. Thus radiation doses in the therapeutic range did not, for the spheroids studied, produce rapid increases in the oxygen tension. When a change occurred, it appeared rather late and was probably a consequence of cell degeneration.

Adenocarcinoma↗