| 1. |
- Berggren, Anna M., et al.
(författare)
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Short‐chain fatty acid content and pH in caecum of rats fed various sources of starch
- 1995
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Ingår i: Journal of the Science of Food and Agriculture. - : Wiley. - 0022-5142 .- 1097-0010. ; 68:2, s. 241-248
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Tidskriftsartikel (refereegranskat)abstract
- Caecal pH and contents of short‐chain fatty acids (SCFA) were registered in rats fed three potential sources of resistant starch (RS); raw pea starch, raw potato starch, and an RS‐enriched preparation obtained from wheat starch by autoclaving and enzymatic incubation. Small intestinal digestibility and delivery of RS to the hind‐gut in the case of raw starches were determined by analysis of faecal starch in animals treated with antibiotics to prevent hind‐gut fermentation. RS content in the RS‐enriched preparation was determined as total starch remaining in an enzymatic gravimetric dietary fibre residue. The fermentability of RS was estimated from the faecal recovery of starch in normal animals with intact hind‐gut microflora. Approximately 35 g per 100 g and 32 g per 100 g were RS in the case of raw potato starch and the RS‐enriched preparation, respectively, versus only 1 g per 100 g in the case of raw pea starch. The caecal pH decreased with all test diets, being most significant with raw potato starch. SCFA production and faecal bulking were negligible with raw pea starch, whereas both raw potato starch and the RS‐enriched preparation significantly increased these parameters. The fermentability of RS in raw potato starch and the RS‐enriched preparation was similar, or about 60–70%. If calculated on basis of fermented amount, RS in raw potato starch was more potent in generating SCFA (49 μmol g−1) than in the RS‐enriched preparation (19 μmol g−1). RS in raw potato starch also displayed the highest faecal bulking capacity. In fact, the faecal dry weight increased more than expected merely from delivery of RS. The relative proportion in caecal contents of acetic‐, propionic‐ and butyric acid was 70, 17 and 8%, respectively, with no significant differences between the three sources of RS.
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| 2. |
- Rydberg, Lennart, 1944, et al.
(författare)
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Extracorporeal ("ex vivo") connection of pig kidneys to humans. II. The anti-pig antibody response.
- 1996
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Ingår i: Xenotransplantation. - : Wiley. - 0908-665X .- 1399-3089. ; 3:4, s. 340-53
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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.
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| 3. |
- Berggren, A M, et al.
(författare)
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Influence of orally and rectally administered propionate on cholesterol and glucose metabolism in obese rats
- 1996
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Ingår i: British Journal of Nutrition. - 0007-1145. ; 76:2, s. 94-287
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Tidskriftsartikel (refereegranskat)abstract
- It has increasingly been suggested that the short-chain fatty acids (SCFA) acetic, propionic and butyric acids, derived from colonic fermentation of dietary fibre and other indigestible carbohydrates, exert different physiological effects. Formation of propionic acid is discussed in terms of beneficial effects on glucose and cholesterol metabolism. The aim of the present study was to evaluate possible metabolic effects of propionic acid and to differentiate between effects mediated in the upper gastrointestinal tract and those mediated in the hind-gut. For this purpose, obese hyperinsulinaemic (fa/fa) rats were studied during a 19 d test period. Sodium propionate was either fed orally through the diet (1 g/d), or infused rectally (0.15 g/d) to animals given diets high in cholesterol (20 g/kg) and saturated fat (130 g/kg). At the end of the test period total liver cholesterol pools were 20% lower (P < 0.01) in rats given dietary or rectally infused propionate (481 and 484 mg respectively) compared with the control group (614 mg). This was due to lower liver weights (P < 0.05) in propionate-treated animals, 15.5 and 15.3 g, v. 18.2 g in the control group, and no differences were noted in hepatic cholesterol concentrations. The urinary glucose excretion was measured during days 15-19 and was found to be lower (P < 0.05) in rats fed with propionate (23 mg) compared with the control group or the group infused rectally (39 and 38 mg respectively). In addition, fasting plasma glucose concentrations decreased significantly (P < 0.05) over the test period. It is concluded that orally supplied propionate affects both glucose and cholesterol metabolism as judged from lowered urinary glucose excretion, fasting blood glucose and liver cholesterol pools. On the other hand, propionate administered to the hind-gut at a physiologically relevant level reduces the hepatic cholesterol pool.
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| 4. |
- Björck, M, et al.
(författare)
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An experimental porcine model of partial ischaemia of the distal colon.
- 1997
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Ingår i: European Journal of Surgery. - 1102-4151 .- 1741-9271. ; 163:11, s. 843-50
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Ischaemia of the colon is a major challenge in aortoiliac surgery. The aim was to establish an animal model of partial distal colonic ischaemia to study interventional strategies.DESIGN: Randomised experiment.SETTING: University Hospital. Department of Experimental Research.MATERIAL: 19 pigs.INTERVENTIONS: 11 Pigs were subjected to ischaemia consisting of total occlusion of the inferior mesenteric artery and partial occlusion of the superior mesenteric artery. Eight animals were sham controls. Dextran was given.MAIN OUTCOME MEASURES: Haemodynamic measurements, intramucosal pH-measurements (pHi) and histological grading.RESULTS: Both ischaemic animals and controls remained haemodynamically stable. It was possible to maintain stable ischaemia in the distal colon in the pHi-range of 6.9-7.1. There was histological mucosal damage of the distal colon in ischaemic animals but not in controls.CONCLUSIONS: The model could be of value when studying interventional strategies to reduce or reverse ischaemia.
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| 5. |
- Breimer, Michael, 1951, et al.
(författare)
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Extracorporeal ("ex vivo") connection of pig kidneys to humans. I. Clinical data and studies of platelet destruction.
- 1996
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Ingår i: Xenotransplantation. - : Wiley. - 0908-665X .- 1399-3089. ; 3:4, s. 328-39
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Tidskriftsartikel (refereegranskat)abstract
- The pioneering experiment by Welsh et al. (Immunological Lett 1991:29:167-170) connecting a pig kidney to the human circulation has been repeated in a modified manner. Two volunteer dialysis patients were pretreated by daily plasmapheresis on days -2,-1, and 0 to remove the naturally occurring anti-pig xenoantibodies. The anti-pig lymphocytotoxic liters were reduced from 1:8 to 1:2 in patient 1 and from 1:8 to 1:1 in patient 2. No steroids or immunosuppressive drugs were administrated before or during the experiments. A sterile pig kidney was extracorporeally ("ex vivo") connected to the patients a/v fistula using an arterial and a venous pump similar to a dialysis. The two experiments gave different results. In the first experiment the perfusion pressure was kept at 100 mmHg for the initial 25 min by reducing the pump speed until the minimum blood flow of 30 ml/min was reached. Thereafter, the pressure rose continuously and the experiment was terminated at 65 min at a perfusion pressure of 200 mmHg. The patient did not feel any discomfort during the perfusion. In the second experiment, a stable blood flow of 200 ml/min was reached at a pressure of 100 mmHg after a few minutes. The perfusion was terminated at 15 min when the patient developed chest and abdominal pain, hypotension, and electrocardiographic signs of myocardial ischemia. The patient recovered quickly. In the first experiment, small volumes of clear urine was produced until the pressure rose above 100 mmHg, which resulted in hematuria. In the second experiment clear urine (4 ml/min) was produced. (51)Chromium clearance values were after 15 min <1 ml/min for kidney 1 and 12 ml/min (8 ml/min/100 g) for kidney 2. A drastic reduction in platelet count (128 to 48 and 64 to 8 × 10(9)/1, respectively) during the passage through the kidney was found in blood samples collected simultaneously before and after the organ. No change in hemoglobin values and leucocyte counts were found. Light- and electron-microscopical analysis of the kidney tissues revealed for kidney 1 focal areas with obliteration of the glomerular and peritubular capillaries by platelets and PMN cells and severe damage of the endothelial cells comparable to a picture of a hyperacute rejection. In kidney 2, all vessels were patent but in the capillaries large amount of membrane fragments were detected by electron microscopy and a discrete damage of the endothelial cells were seen in some segments. No intact platelets were present in the vascular tree. These human experiments support the hypothesis that hyperacute rejection of pig to human xenografts is delayed in time by removal of the preformed anti-pig xenoantibodies. A new finding was a very rapid destruction of platelets occurring in the kidney of patient 2 who had very low liters of xenoantibodies. The humoral immune response is described in detail in an accompanying paper (Rydberg et al., this issue).
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| 6. |
- Ingolfsson, O., et al.
(författare)
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Antarctic glacial history since the Last Glacial Maximum: an overview of the record on land
- 1998
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Ingår i: Antarctic Science. - 1365-2079. ; 10:3, s. 326-344
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Tidskriftsartikel (refereegranskat)abstract
- This overview examines available circum-Antarctic glacial history archives on land, related to developments after the Last Glacial Maximum (LGM). It considers the glacial-stratigraphic and morphologic records and also biostratigraphical information from moss banks, lake sediments and penguin rookeries, with some reference to relevant glacial marine records. It is concluded that Holocene environmental development in Antarctica differed from that in the Northern Hemisphere. The initial deglaciation of the shelf areas surrounding Antarctica took place before 10 000 14C yrs before present (BP), and was controlled by rising global sea level. This was followed by the deglaciation of some presently ice-free inner shelf and land areas between 10 000 and 8000 yr BP. Continued deglaciation occurred gradually between 8000 yr BP and 5000 yr BP. Mid-Holocene glacial readvances are recorded from various sites around Antarctica. There are strong indications of a circum-Antarctic climate warmer than today 4700-2000 yr BP. The best dated records from the Antarctic Peninsula and coastal Victoria Land suggest climatic optimums there from 4000-3000 yr BP and 3600-2600 yr BP, respectively. Thereafter Neoglacial readvances are recorded. Relatively limited glacial expansions in Antarctica during the past few hundred years correlate with the Little Ice Age in the Northern Hemisphere.
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