| 1. |
- Landin-Olsson, Mona, et al.
(author)
-
Immunoreactive trypsin(Ogen) in the sera of children with recent-onset insulin-dependent diabetes and matched controls
- 1990
-
In: Pancreas. - : Ovid Technologies (Wolters Kluwer Health). - 0885-3177. ; 5:3, s. 241-247
-
Journal article (peer-reviewed)abstract
- To evaluate the exocrine pancreatic function at the time of diagnosis of insulin-dependent diabetes mellitus, we determined immunoreactive an-odal and cathodal trypsin(ogen) levels in sera from almost all children (n = 375) 0-14 years of age in Sweden in whom diabetes developed during 1 year, and in sex-, age-, and geographically matched control subjects (n = 312). The median level of anodal trypsin(ogen) was 5 (quartile range, 3-7) µg/L in children with newly diagnosed diabetes, compared with a median level of 7 (quartile range, 4-8) µg/L in control subjects (p < 0.0001). Similarly, the median level of cathodal trypsin(ogen) was 8 (quartile range, 4-10) µg/L in children with diabetes, compared with a median level of 11 (quartile range, 7-15) µg/L in control subjects (p < 0.0001). The median of the individual ratios between cathodal and anodal trypsin(ogen) was 1.4 in the diabetic patients and 1.7 in the control children (p < 0.001). In a multivariate test, however, only the decrease in cathodal trypsin(ogen) concentration was associated with diabetes. The levels of trypsin(ogen)s did not correlate with levels of islet cell antibodies, present in 81% of the diabetic children. Several mechanisms may explain our findings, for example, similar pathogenetic factors may affect both the endocrine and exocrine pancreas simultaneously, a failing local trophic stimulation by insulin on the exocrine cells may decrease the trypsinogen production, and there may be an increased elimination of trypsin(ogen) because of higher filtration through the kidneys in the hyperglycemic state.
|
|
| 2. |
- Bernspång, Lars, et al.
(author)
-
Verification of an explicit finite-element code for the simulation of the press forming of rectangular boxes of coated sheet steels
- 1993
-
In: Journal of Materials Processing Technology. - : Elsevier BV. - 0924-0136 .- 1873-4774. ; 39:3-4, s. 431-453
-
Journal article (peer-reviewed)abstract
- The industrial aim for shorter lead times in the development process for new products has encouraged a fast development of finite-element procedures for the simulation of sheet-metal forming. These procedures can shorten the design stage for new sheet-forming tools and the try-out period. In order to reach these goals robust calculation procedures and extensive verification of results are required. This paper presents a detailed validation of one promising type of finite-element code, namely the explicit code DYNA3D. Experiments for verification were performed on a zinc-coated sheet steel with a hot-dip galvanized coating. Stretch forming and deep drawing of cylindrical cups were performed. Rectangular boxes were formed from rectangular blanks and blanks with cut corners. Dies both with and without draw beads were used. Punch forces, flange draw-in and strain distributions were measured. The pressings with cylindrical shape were used to determine coefficients of friction with a fitting procedure based on comparison of data from pressings and from the DYNA3D calculations. These tribological data and constitutive data of the steels were used in the simulation of pressings of rectangular boxes. The calculations with DYNA3D gave a good description of flange draw-in and the strain distributions in the pressings. In most of the cases studied the punch-force curves were well reproduced. It is concluded that the present code is well suited for the simulation of sheet-forming operations.
|
|
| 3. |
|
|
| 4. |
- Lindström, K, et al.
(author)
-
Glycosphingolipid expression in spontaneously aborted fetuses and placenta from blood group p women. Evidence for placenta being the primary target for anti-Tja-antibodies.
- 1992
-
In: Glycoconjugate journal. - 0282-0080. ; 9:6, s. 325-9
-
Journal article (peer-reviewed)abstract
- A 12-week-old fetus and one 17-week-old fetus + placenta were obtained after spontaneous abortions from two women of blood group p. The 17-week-old fetus was dissected into intestine, liver, brain and residual tissue. Nonacid glycosphingolipid fractions were prepared from the tissues. Glycolipid characterization was carried out using thin layer chromatography immunostained with monoclonal antibodies and bacteria and by 1H NMR spectroscopy and mass spectrometry. In the placental fraction substantial amounts of globotetraosylceramide (P-antigen) and globotriaosylceramide (Pk-antigen) were identified. In contrast, the fetuses contained only trace amounts of these structures, as revealed by immunostaining. These results indicate that the primary target for the antibodies of the anti-Tja serum is the placenta tissue, resulting in termination of the pregnancy.
|
|
| 5. |
- Lindström, K, et al.
(author)
-
Non-acid glycosphingolipid expression in plasma of an A1 Le(a-b+) secretor human individual: identification of an ALeb heptaglycosylceramide as major blood group component.
- 1992
-
In: Journal of biochemistry. - 0021-924X. ; 111:3, s. 337-45
-
Journal article (peer-reviewed)abstract
- Total non-acid glycosphingolipids were isolated from plasma of an A1 Le(a-b+) secretor individual with Refsum's disease (phytanic acid storage disease). The glycolipids were separated into 11 fractions by open column chromatography and by HPLC. The fractions were analyzed by thin-layer chromatography and tested for different blood group A activities as well as blood group Le(a )and Leb activity. The fractions were structurally characterized by proton NMR spectroscopy and FAB mass spectrometry and in selected cases by EI mass spectrometry of the permethylated and permethylated-reduced derivatives. Degradation analysis was performed on partially permethylated or permethylated-reduced alditol acetates. The dominating blood group compound was found to be a blood group A active type 1 chain difucosylheptaglycosylceramide. Other blood group compounds were identified as a blood group A active type 1 chain monofucosylhexaglycosylceramide, a blood group Leb hexaglycosylceramide, a blood group H active type 1 chain pentaglycosylceramide, and a globotetraosylceramide (the P-antigen). The presence of a Le(a) glycosphingolipid and blood group A type 3/4 chain structures were also found by immunostaining. Glucosyl-, lactosyl-, and globotriaosylceramides were the dominating short chain compounds. The amount of phytanic acid incorporated into the monoglycosylceramide fraction was found to be less than 5% of the fatty acids.
|
|
| 6. |
|
|
| 7. |
- PALMQVIST, K, et al.
(author)
-
MECHANISMS OF ADAPTATION OF MICROALGAE TO CONDITIONS OF CARBON-DIOXIDE LIMITATION OF PHOTOSYNTHESIS - POSSIBLE ROLE OF CARBONIC-ANHYDRASE
- 1990
-
In: SOVIET PLANT PHYSIOLOGY. - 0038-5719. ; 37:5, s. 680-686
-
Journal article (peer-reviewed)abstract
- We studied the rate of assimilation of inorganic carbon (C(in)) in relation to CO2 concentration in Dunaliella salina. Chlorella vulgaris, Scenedesmus obliguus, and Chlamydomonas reinhardtii WT grown at 5 and 0.03% CO2. It is demonstrated that K(m) (CO2) of photosynthesis reached 50-60-mu-M in algae grown at 5% CO2, but 2-5-mu-M at 0.03% CO2. Carbonic anhydrase (CA) activity of intact cells and in the homogenate was significantly higher in algae grown at 0.03% CO2 than at 5% CO2. Several forms of CA are present, viz., soluble (sCA), membrane-bound CA of cytoplasmic (cCA) and thylakoid (tCA) membranes, and CA of intact cells (iCA). Acetoazolamide lowered the rate of C(in) assimilation in algae grown at 0.03% CO2, whereas ethoxyzolamide totally suppressed the ability of the algae to adapt to low CO2 concentrations. The inhibitor of plasmalemma ATPase vanadate likewise suppressed the rate of C(in) assimilation in the algae. It is concluded that enzymatic reactions catalyzed by CA and plasmalemma ATPase are involved in adaptation of algae to low CO2 concentrations and in mechanisms of C(in) concentration. Mechanisms governing adaptation of algae to conditions of carbon dioxide limitation of photosynthesis are discussed in the paper.
|
|
| 8. |
- PALMQVIST, K, et al.
(author)
-
PHOTOBIONT-RELATED DIFFERENCES IN CARBON ACQUISITION AMONG GREEN-ALGAL LICHENS
- 1994
-
In: Planta. - 0032-0935 .- 1432-2048. ; 195:1, s. 70-79
-
Journal article (peer-reviewed)abstract
- The photosynthetic properties of a range of lichens (eight species) containing green algal primary photobionts of either the genus Coccomyxa, Dictyochloropsis or Trebouxia were examined with the aim of obtaining a better understanding for the different CO2 acquisition strategies of lichenized green algae. Fast transients of light/dark-dependent CO2 uptake and release were measured in order to screen for the presence or absence of a photosynthetic CO2-concentrating mechanism (CCM) within the photobiont. It was found that lichens with Trebouxia photobionts (four species) were able to accumulate a small pool of inorganic carbon (DIC; 70-140 nmol per mg chlorophyll (Chl)), in the light, which theoretically may result in, at least, a two- to threefold increase in the stromal CO2 concentration, as compared to that in equilibrium with ambient air. The other lichens (four species), which were tripartite associations between a fungus, a cyanobacterium (Nostoc) and a green alga (Coccomyxa or Dictyochloropsis) accumulated a much smaller pool of DIC (10-30 nmol.(mg Chl)(-1)). This pool is most probably associated with the previously documented CCM of Nostoc, inferred from the finding that free-living cells of Coccomyxa did not show any signs of DIC accumulation. In addition, the kinetics of fast CO2 exchange for free-living Nostoc were similar to those of intact tripartite lichens, especially in their responses to the CCM and the carbonic anhydrase (CA) inhibitor ethoxyzolamide. Trebouxia lichens had a higher photosynthetic capacity at low and limiting external CO2 concentrations, with an initial slope of the CO2-response curve of 2.6-3.9 mu mol.(mg Chl)-1.h(-1).Pa-1, compared to the tripartite lichens which had an initial slope of 0.5-1.1 mu mol.(mg Chl)(-1).h(-1).Pa-1, suggesting that the presence of a CCM in the photobiont affects the photosynthetic performance of the whole lichen. Regardless of these indications for the presence or absence of a CCM, ethoxyzolamide inhibited the steady-state rate of photosynthesis at low CO2 in all lichens, indicating a role of CA in the photosynthetic process within all of the photobionts. Measurements of CA activity in photobiont-enriched homogenates of the lichens showed that Coccomyxa had by far the highest activity, while the other photobionts displayed only traces or no activity at all. As the CCM is apparently absent in Coccomyxa, it is speculated that this alga compensates for this absence with high internal CA activity, which may function to reduce the CO2-diffusion resistance through the cell.
|
|
| 9. |
- PALMQVIST, K, et al.
(author)
-
ROLE OF CARBONIC-ANHYDRASE IN ASSIMILATION OF INORGANIC CARBON IN DUNALIELLA-SALINA
- 1991
-
In: SOVIET PLANT PHYSIOLOGY. - 0038-5719. ; 38:3, s. 339-345
-
Journal article (peer-reviewed)abstract
- We studied changes in the rate of photosynthetic assimilation of inorganic carbon (C(i)) in relation to CO2 concentration by Dunaliella salina cells adapted to high (5%) and low (0.03%) concentrations of CO2. It is demonstrated that the rate of C(i) assimilation was higher in algae adapted to 0.03% CO2 than in culture adapted to 0.03% CO2. The period of adaptation of D. salina to low CO2 concentrations lasted 5-6 h, during which time activity of carbonic anhydrase (CA) increased on the cell surface and inside cells. Soluble CA (sCA) was detected in D. salina, together with membrane-bound CA of cytoplasmic (cCA) and thylakoid (tCA) membranes. The effect of CA inhibitors - acetazolamide (AZA) and ethoxyzolamide (EZA) - on photosynthesis of D. salina cells was studied in the work. It turned out that EZA lowered the rate of O2 evolution in algae adapted to 5% CO2 and totally suppressed this process in algae adapted to 0.03% CO2. Acetazolamide lowered the photosynthetic rate only in algae adapted to 0.03% CO2. It is concluded that intracellular forms of CA are needed for functioning of the C1-concentration mechanism in algae adapted to conditions of carbon dioxide limitation of photosynthesis. The authors discuss the mechanisms of adaptation of D. salina to low CO2 concentrations and the role played by CA in this process.
|
|
| 10. |
|
|
