| 1. |
- Anderbrant, O., et al.
(författare)
-
Electrophysiological and morphological characteristics of pheromone receptors in male pine sawflies, Diprion pini (Hymenoptera : Diprionidae), and behavioural response to some compounds
- 1995
-
Ingår i: Journal of Insect Physiology. - : Elsevier BV. - 0022-1910. ; 41:5, s. 395-401
-
Tidskriftsartikel (refereegranskat)abstract
- The morphology and physiology of pheromone receptors on the antennae of male pine sawflies, Diprion pini L., were investigated. Using scanning electron microscopy, five sensillar types were recognized. The type shown to be pheromone sensitive has a long (50-70 μm) cuticular hair, is single-walled, and is innervated by 8 or 9 sensory cells as revealed by transmission electron microscopy. Electroantennography (EAG) showed similar activity of the acetate and propionate of (2S,3R,7R)-3,7-dimethyl-2-tridecanol, precursor of the main constituent of the female-produced sex pheromone. No other isomer induced any significant response. Single-sensillum recordings confirmed the results of the EAG, and also showed that several neurons were excited by the active compound. EAG recordings and combined gas chromatographic-electroantennographic detection indicated that esters of three 3,7-dimethyl-2-pentadecanol (diprionol) isomers were active, but field tests could not demonstrate any behavioural effect. Diprionol esters are used as sex pheromones by all other pine sawflies investigated so far, and D. pini is thus the first diprionid species shown to use a different sex pheromone.
|
|
| 2. |
- Choularton, T. W., et al.
(författare)
-
The Great Dun Fell Cloud Experiment 1993 : An overview
- 1997
-
Ingår i: Atmospheric Environment. - 1352-2310. ; 31:16, s. 2393-2405
-
Tidskriftsartikel (refereegranskat)abstract
- The 1993 Ground-based Cloud Experiment on Great Dun Fell used a wide range of measurements of trace gases, aerosol particles and cloud droplets at five sites to study their sources and sinks especially those in cloud. These measurements have been interpreted using a variety of models. The conclusions add to our knowledge of air pollution, acidification of the atmosphere and the ground, eutrophication and climate change. The experiment is designed to use the hill cap cloud as a flow-through reactor, and was conducted in varying levels of pollution typical of much of the rural temperate continental northern hemisphere in spring-time.
|
|
| 3. |
|
|
| 4. |
- Rydberg, Lennart, 1944, et al.
(författare)
-
Extracorporeal ("ex vivo") connection of pig kidneys to humans. II. The anti-pig antibody response.
- 1996
-
Ingår i: Xenotransplantation. - : Wiley. - 0908-665X .- 1399-3089. ; 3:4, s. 340-53
-
Tidskriftsartikel (refereegranskat)abstract
- Pig kidneys were extracorporeally "ex vivo" connected to the circulation of two volunteer male dialysis patients (Breimer et al., this issue). The patients were pretreated by daily plasmapheresis for 3 consecutive days, which reduced the anti-pig lymphocytotoxic titer from 8 to 2 in the first patient and from 8 to 1 in the second patient. The anti-pig hemagglutinating titers were reduced from 32 to 4 in the first patient and from 2 to 1 in the second patient. No drugs, except heparin, were given. The perfusion lasted for 65 min in patient 1 and the experiment was terminated due to increased vascular resistance in the pig kidney. Ultrastructural investigation showed a picture similar to a hyperacute vascular rejection. Immunohistochemical studies showed a weak staining of IgM antibodies, but no IgG in the small arteries and glomeruli. The pig kidney of patient 2 was perfused for 15 min and the experiment terminated due to serious side effects of the patient. Light and electron microscopical investigation showed virtually no structural changes of the kidney tissue and immunostaining for human antibodies was negative. In both patients, serum samples collected 2-5 weeks postperfusion showed a strong anti-pig antibody titer rise (up to 512) which thereafter declined but stabilized on a higher level than before the experiment. The antibody response in the two patients was different. In patient 1, the major anti-pig antibodies directed to carbohydrate antigens were of IgG (IgG1 and IgG2 subclasses) type, while the IgM response was less prominent and virtually no IgA antibodies were produced. Despite the short duration of the perfusion in patient 2, a humoral immune response was seen that was mainly confined to the IgA immunoglobulin class (IgA1 subclass). Blood group glycospingolipid fractions, prepared from the contralateral kidney of the donor pigs, were used for immunostaining with patient serum samples. In both patients, the antibodies produced after the perfusion, mainly recognized the Galα1-3Gal epitope both as part of the "linear B" pentasaccharide but also on more complex carbohydrate structures. Patient 1 was HLA-immunized before the experiment due to a kidney allograft and had a panel reactivity of 85% before the perfusion. No change in the panel reactivity of HLA-antibodies was found after the perfusion experiments. Patient 2 had no HLA antibodies before and remained negative after the perfusion. Patient serum samples collected before and after the perfusion were tested for reactivity against human endothelial cell lines. No antibodies were generated.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Hallberg, Eva C., 1966, et al.
(författare)
-
Chemical and lectin-gold electron microscopical studies of the expression of the Galalpha1-determinant in the pig aorta.
- 1998
-
Ingår i: Xenotransplantation. - 0908-665X. ; 5:4, s. 246-56
-
Tidskriftsartikel (refereegranskat)abstract
- In the xenotransplantation research field, pig aortic endothelial cells are frequently used in different model systems, e.g., for the study of the xenoantibody-antigen reaction. The Gal(alpha1),3Gal determinant is the major target for human xenoreactive antibodies in pig tissue. Characterisation of the Gal(alpha1)- distribution in pig aortic endothelial cells is thus important for understanding the reaction occurring at the endothelial cells during the xenorejection. We have determined the complete structure of the major Gal(alpha1),3Gal terminated glycolipid, Gal(alpha1),3nLc4Cer. Structural studies were performed on isolated glycosphingolipids by mass spectrometry and NMR spectroscopy. The results show a predominance of the pentasaccharide among the Gal(alpha1)-terminated glycolipids but also the presence of several Gal(alpha1)-terminated glycolipids with extended carbohydrate core chains. Ultrastructural localisation of the Galalpha1-antigen in pig aorta was done by lectin-gold electron microscopic studies of aortic wall sections using the Griffonia simplicifolia isolectin B4. Gal(alpha1)-determinants are predominantly localised on the luminal surface of pig aortic endothelial cells and endothelial cells of vasa vasorum and, to a lesser extent, vascular subendothelium.
|
|
| 8. |
|
|
| 9. |
- Hallberg, K. B., et al.
(författare)
-
Arsenic toxicity is not due to a direct effect on the oxidation of reduced inorganic sulfur compounds byThiobacillus caldus
- 1996
-
Ingår i: FEMS Microbiology Letters. - 0378-1097 .- 1574-6968. ; 145:3, s. 409-414
-
Tidskriftsartikel (refereegranskat)abstract
- Thiobacillus caldus is a moderately thermophilic acidophile which has been implicated in the biooxidation of arsenic containing mineral sulfides. The toxic effects of arsenic on this bacterium are presented here. Addition of arsenite to a growing culture of T. caldus caused a transient increase in the optical density of the culture while causing a simultaneous decrease in cell viability. The increase in optical density was shown to be due to the formation of extracellular sulfur. The oxidation rates of tetrathionate and thiosulfate were decreased by increasing concentrations of arsenite, while in a culture induced to arsenic resistance the rates were not as adversely effected. Sulfur oxidation was also inhibited to the same extent as tetrathionate oxidation, with the oxidation of solid sulfur being slightly more effected than the oxidation of sulfur dissolved in acetone. Thus, bactericidal arsenite causes a transient formation of extracellular sulfur in the culture supernatant of T. caldus yet the toxicity of arsenite is not due to direct inhibitory effects on reduced inorganic sulfur compound oxidation by these bacteria.
|
|
| 10. |
- Hallberg, K B, et al.
(författare)
-
Reduced sulfur compound oxidation by Thiobacillus caldus.
- 1996
-
Ingår i: Journal of Bacteriology. - 0021-9193 .- 1098-5530. ; 178:1, s. 6-11
-
Tidskriftsartikel (refereegranskat)abstract
- The oxidation of reduced inorganic sulfur compounds was studied by using resting cells of the moderate thermophile Thiobacillus caldus strain KU. The oxygen consumption rate and total oxygen consumed were determined for the reduced sulfur compounds thiosulfate, tetrathionate, sulfur, sulfide, and sulfite in the absence and in the presence of inhibitors and uncouplers. The uncouplers 2,4-dinitrophenol and carbonyl cyanide m-chlorophenyl-hydrazone had no affect on the oxidation of thiosulfate, suggesting that thiosulfate is metabolized periplasmically. In contrast, the uncouplers completely inhibited the oxidation of tetrathionate, sulfide, sulfur, and sulfite, indicating that these compounds are metabolized in the cytoplasm of T. caldus KU. N-Ethylmaleimide inhibited the oxidation of tetrathionate and thiosulfate at the stage of elemental sulfur, while 2-heptyl-4-hydroxyquinoline-N-oxide stopped the oxidation of thiosulfate, tetrathionate, and elemental sulfur at the stage of sulfite. The following intermediates in the oxidation of the sulfur compounds were found by using uncouplers and inhibitors: thiosulfate was oxidized to tetrathionate, elemental sulfur was formed during the oxidation of tetrathionate and sulfide, and sulfite was found as an intermediate of tetrathionate and sulfur metabolism. On the basis of these data we propose a model for the metabolism of the reduced inorganic sulfur compounds by T. caldus KU.
|
|
