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J Halttunen

Publications and source records attributed to J Halttunen.

At least 19 recordsLinked to original sources

Bactericidal/permeability-increasing protein and group I and II phospholipase A2 during the induction phase of human acute pancreatitis.

Activated endogenous mediators of inflammation have important roles in the pathogenesis and complications of acute pancreatitis (AP). These mediators include bactericidal/ permeability-increasing protein (BPI) and phospholipase A2 (PLA2). The time course of their activation during human AP is not known. The aim of this study was to evaluate the kinetics of BPI, group I (pancreatic) and group II (synovial type) PLA2 during human AP with temporally defined onset, as being induced by endoscopic retrograde cholangiopancreatography (ERCP). Serum samples of 273 consecutive patients undergoing ERCP were collected before and at 3, 6, and 24 h after ERCP. Twenty-four (8.7%) patients developed ERCP-induced pancreatitis. Seven of them were graded to have a severe disease. Forty randomly selected patients undergoing ERCP without evidence of pancreatitis served as controls. The serum concentrations of BPI and groups I and II PLA2 were measured by specific immunoassays. The mean concentration of BPI increased from 14 to 26 microg/L at 24 h after ERCP in patients with AP. In the control group, BPI values remained unchanged, and the difference was statistically significant (p<0.001). The increase of BPI was seen in 22 of 28 patients with AP at 3 h after the onset of the disease. BPI values were higher in severe post-ERCP pancreatitis than in mild disease (p = 0.07; NS). The serum concentrations of group II PLA2 before ERCP were consistently higher in the control patients than in the patients with pancreatitis, 65.8 and 14.2 microg/L, respectively. High baseline values in the control group were associated with preexisting infectious diseases. Thereafter, the mean concentration decreased in the control group to 44 microg/L and increased in the pancreatitis group up to 27.5 microg/L. The difference was statistically significant (p = 0.007). Increased group II PLA2 values were seen in 10 of 17 patients with mild AP and in five of seven patients with severe disease. There were no significant differences in group I or II PLA2 values in patients with mild or severe AP. The serum concentration of group I PLA2 increased in the patients with post-ERCP pancreatitis from 5.4 to 37.5 microg/L at 24 h. The difference was statistically significant, (p< 0.001) as compared with controls. In conclusion, in acute pancreatitis, the increase of BPI in serum starts at 3 h after the onset of the disease, and the concentration seems to correlate with the severity of the disease. Increased group II PLA2 concentrations also were seen in patients with mild AP. The kinetics of group I PLA2 resembles that of other pancreatic enzymes.

Acute Disease

Absorption, excretion, and distribution of plant sterols after proximal gut resection and autotransplantation of porcine ileum.

Contribution of different gut segments to plant sterol absorption, adaptation of plant sterol absorption after partial small bowel resection, and effects of gut transplantation (necessitates extrinsic autonomic denervation and lymphatic disruption) on plant sterol biodynamics are unclear. We studied the consequences of massive proximal small bowel resection and autotransplantation of the remaining ileum on the adaptive absorption and biodynamics of plant sterols. Dietary, fecal, biliary, hepatic and plasma plant sterols, fecal elimination and absorption of cholesterol, small bowel morphology, and intestinal transit were determined before (n = 5) and at 4, 8, and 14 wk after resection of the proximal 75% of the jejunoileum (n = 15) and autotransplantation of the remaining ileum (n = 15) or transection (n = 5). Proximal gut resection significantly reduced cholesterol absorption efficiency; percentage absorption and biliary secretion of plant sterols; plasma, biliary and hepatic campesterol-to-cholesterol proportions; and sitosterol proportions in plasma and bile. Autotransplantation of the remaining ileum further significantly decreased cholesterol absorption efficiency; percentage absorption and biliary secretion of campesterol; campesterol proportions in plasma, bile and liver; and plasma proportions of sitosterol while increasing fecal excretion of neutral and acidic steroids. Plasma proportions of the two plant sterols, but absorption of just campesterol, were gradually improved with increasing cholesterol absorption and villus height after proximal gut resection; the same result was observed to a lesser degree after ileal autotransplantation. In addition, significant positive correlations were found between percentage cholesterol and campesterol absorption and the plasma plant sterol proportions in both proximal resection groups, between campesterol absorption and ileal villus height in the resection group, and between campesterol absorption and intestinal transit time in the autotransplantation group. In conclusion, plasma campesterol and sitosterol closely reflect absorption of cholesterol and plant sterols from intact and autotransplanted ileum during adaptation to proximal gut resection. A loss of proximal gut absorptive surface impairs cholesterol and campesterol absorption more than sitosterol absorption, the latter being apparently less dependent on available jejunal villus surface area.

Animals

Nerve terminals containing neuropeptides decrease in number after massive proximal small bowel resection in the piglet.

The aim of this study was to evaluate possible changes in the neuropeptide innervation pattern of the remaining porcine ileum following 75% proximal resection of the small intestine. Three-month-old piglets were operated on and two months postoperatively full-thickness specimens of the proximal part of the distal ileum wall were taken. Age-matched 3- and 5-month-old unoperated piglets were used as controls. The number and intensity of VIP-, galanin-, enkephalin-, substance P-, and somatostatin-containing nerve fibers were estimated in sections processed for immunofluorescence microscopy and subjected to quantitative scoring. The VIP-, galanin-, and enkephalin-immunoreactive fibers of the circular muscle layer and villi were also quantitated by computer-assisted morphometry. The number and intensity of VIP-immunoreactive fibers in the mucosa and circular muscle layer markedly decreased after resection as compared to 3-month-old and 5-month-old controls (P < 0.05). The galanin immunoreactivity index decreased significantly after resection in the circular muscle layer as compared to both control groups (P < 0.05). The increase in the number of enkephalin-immunoreactive nerve fibers that normally occurred from 3 to 5 months of age was inhibited by the resection. We were not able to see any differences in somatostatin or substance P immunoreactivity between the groups. The results suggest that massive resection induces significant changes in the neuropeptide-containing innervation of the remaining small intestine. These findings are compatible with altered motor activity and mucosa function in the remain intestine.

Adaptation, Physiological

Intestinal adaptation after massive proximal small-bowel resection in the pig.

BACKGROUND: Small-intestinal adaptation to resection has been extensively studied in rats. The present study investigates morphology, crypt cell proliferation, and disaccharidase activities of the remaining small intestine and colon after 75% proximal resection of porcine small intestine. METHODS: Specimens were obtained from the proximal jejunum, middle and distal ileum, and proximal colon preoperatively (n = 5) and 14 weeks after small-bowel transection (n = 5) or resection (n = 5). Proliferation was analyzed immunohistochemically with the Ki-67 antigen MIB-1. Disaccharidase activities were determined in accordance with the method of Dahlqvist. RESULTS: In addition to macroscopic enlargement, resection markedly increased the villi and crypts of the remaining small bowel. Crypt cell proliferation decreased with advancing age after transection but remained at the preoperative level after resection. Specific, but not total, activities of maltase and sucrase in the mid-ileum decreased after resection. CONCLUSION: Small-intestinal adaptation in the pig involves macroscopic enlargement and a prompt increase in villus size, which is associated with high crypt cell proliferation.

Animals

Increased plasma, biliary, and hepatic cholesterol precursors in pigs with ileal autotransplantation-induced malabsorption of cholesterol and bile acids.

BACKGROUND: Small-bowel transplantation impairs intestinal absorptive function for unknown reasons. METHODS: The proportions of plasma, biliary, and hepatic cholesterol precursors to cholesterol were determined by gas-liquid chromatography after resection of the proximal 75% of the porcine jejunoileum (n = 15) and autotransplantation of the remaining ileum (n = 15) and were related to in vivo absorption and fecal excretion of cholesterol. RESULTS: Ileal autotransplantation significantly decreased serum (18%; P < 0.05) and liver (7.6%; P < 0.05) cholesterol content, the esterification percentage of serum cholesterol (5.1%; P < 0.0001), and the total amount of cholesterol absorbed (48%; P < 0.05) and increased fecal excretion of bile acids (108%; P < 0.0001), net cholesterol elimination (53%; P < 0.001), and the proportions of plasma (207%; P < 0.0001), biliary (183%; P < 0.0001), and hepatic (114%; P < 0.0001) cholesterol precursors. The increases were most striking for the side-chain-saturated demethylated sterols, cholesterol and lathosterol, and monomethyl sterols, whose bile/liver and plasma/liver ratios were increased in the autotransplantation group. Plasma, biliary, and hepatic precursor proportions were positively related to each other and similarly correlated with fecal bile acids and the net elimination of cholesterol in feces. CONCLUSIONS: These findings suggest that ileal autotransplantation in pigs with proximal gut resection increased the levels of cholesterol precursor sterols in plasma, bile, and liver mainly due to a bile-acid-malabsorption-induced increase in hepatic synthesis of cholesterol. Enhanced secretion of cholesterol precursors from the liver into the plasma and bile may have contributed to their increased values during the increased rate of cholesterogenesis.

Animals

Randomised trial of single and repeated fibrin glue compared with injection of polidocanol in treatment of bleeding peptic ulcer.

BACKGROUND: Although injection treatments for ulcer haemostasis seem to be effective, recurrent bleeding remains a serious problem. Large randomised clinical trials are required to show differences between treatment modalities for gastrointestinal bleeding. The aim of this study was to compare the safety and efficacy of repeated endoscopic injection of fibrin glue (FG) with that of single endoscopic injection of polidocanol in the prevention of recurrent bleeding. METHODS: 854 patients with active gastroduodenal bleeding (spurting, oozing), or ulcers with a visible non-bleeding vessel, were randomly assigned one of three endoscopic treatments: single application of polidocanol 1%, single application of FG, or daily repeated application of FG until the visible vessel had disappeared. All patients were pretreated with local injection of epinephrine (1/10,000), and had daily repeat endoscopies until the vessel observed at initial endoscopy was no longer visible. FINDINGS: Recurrent bleeding rates among the 790 patients in whom the rates could be assessed were 58 (22.8%) of 254 in the polidocranol group, 51 (19.2%) of 266 in the FG-single group, and 41 (15.2%) of 270 in the FG-repeated group. The difference between FG-repeated treatment and polidocanol was significant (p = 0.036). Treatment failed, making other treatments (including surgery) necessary, in 34 (13.0%) of 261 in the polidocanol group, 34 (12.4%) of 274 in the FG-single group, and 21 (7.7%) of 274 in the FG-repeated group. The difference between FG-repeated treatment and polidocanol was significant (p = 0.046). The 30-day-mortality rates were low in all three treatment groups (polidocanol 4.7%; FG-single treatment 5.3%, FG-repeated treatment 4.3%). The safety profiles of the three treatment strategies were similar. INTERPRETATION: Repeated injection with FG glue is significantly more effective than injection with polidocanol 1% in the treatment of bleeding from gastroduodenal ulcers.

Adult

Effect of ileal autotransplantation on cholesterol, bile acids, and biliary lipids in pigs with proximal small bowel resection.

Our major aim was to investigate the consequences of ileal autotransplantation in pigs with proximal small intestinal resection on biliary lipids and metabolism of bile acids. Biliary lipid secretion rates and bile acid absorption were assessed by measuring dietary and biliary lipids, fractional cholesterol absorption, and fecal excretion of cholesterol and bile acids. In addition, serum bile acids and cholesterol, biliary and fecal bile acid species, and ileal villus height were determined after resection of the proximal 75% of the jejunoileum (n = 15) and autotransplantation of the remaining ileum with systemic venous drainage (n = 15) or transection (n = 5). Autotransplantation further increased fecal excretion of neutral and acidic steroids and serum concentration of bile acids after proximal resection (P < .05 for all); autotransplantation significantly decreased serum cholesterol, ileal villus height, fractional bile acid and cholesterol absorption, and biliary molar percentage of total and primary bile acids, whereas biliary secretion of bile acids, enriched by secondary bile acids, and cholesterol remained unchanged. At 14 weeks, ileal villus height, fractional bile acid and cholesterol absorption, biliary molar percentage of bile acids, and proportion of secondary biliary bile acids were altered by transplantation from the respective postresection values of 864 +/- 22 microm, 97.9 +/- 0.6%, 26.9 +/- 3.9%, 91.8 +/- 1.2% and 9.2 +/- 1.3% to 428 +/- 21 microm, 91.1 +/- 1.5%, 9.5 +/- 1.1%, 83.9 +/- 1.4% and 52.5 +/- 3.5% (P < .005 for all). Posttransplantation biliary bile acid secretion correlated positively with fractional reabsorption (r = .70) and biliary molar percentage (r = .73) of bile acids and ileal villus height (r = .65; P < .01 for all). Decreased absorption efficiency and biliary molar percentage of bile acids, increased biliary secondary bile acids, and short ileal villi point to bacterial overgrowth-induced bile acid malabsorption, which with decreased absorptive area may contribute to malabsorption of other lipids after ileal autotransplantation. Compensatory increase in cholesterol synthesis in the pigs with autotransplanted ileum appeared sufficient for constant biliary secretion of cholesterol and bile acids.

Absorption

Value of mucosal biopsies in the monitoring of acute small bowel rejection.

The value of mucosal biopsies in evaluating small bowel rejection is controversial. In this study, the value of mucosal biopsies was estimated in unmodified porcine small bowel rejection. Ten animals received the distal half of the small bowel as a heterotopic loop (Thiry-Vella loop). The allografts were followed by proximally and distally harvested full-thickness and mucosal biopsies every other day, starting from the 3rd day and continuing until the grafts became necrotic. The histological parameters in both types of biopsies were semiquantitatively scored from 0 to 3 and compared with each other. The difference in mean values on the subsequent days was not remarkable, the results favoring slightly higher values in full-thickness than in mucosal biopsies. Our results suggest that multiple mucosal biopsies are adequate in monitoring morphological changes of small bowel grafts during rejection and that the proximal and distal ileum are similarly affected by acute rejection.

Acute Disease

Adaptive lipid metabolism after ileal autotransplantation in pigs with proximal gut resection.

BACKGROUND: Transplantation of the small intestine impairs intestinal absorptive function, but the adaptive response of a segmental graft is unknown. The aim of this study was to investigate the effects of ileal autotransplantation on the adaptive absorption and metabolism of lipids in pigs that had undergone proximal gut resection. METHODS: Serum lipids, plasma vitamins A and E, absorption and excretion of cholesterol, bile acids and fat, plasma cholesterol precursor and plant sterol proportions to cholesterol (respective markers of cholesterol synthesis and absorption), enteric structure, and transit were determined 4, 8, and 14 weeks after 75% proximal resection with (n = 15) or without (n = 15) autotransplantation of the remaining ileum. RESULTS: As compared with pigs that underwent proximal gut resection, the additional autotransplantation reduced the adaptive increase in total serum and high-density lipoprotein cholesterol, plasma plant sterol proportions and vitamin E concentrations, cholesterol and fat absorption efficiency, and villus height (p < 0.05 for all) during the 14 postoperative weeks and resulted in increases of up to 4.6, 2.7, 1.3, and 2.1 times the plasma cholesterol precursors (p < 0.005), fecal excretion of bile acids (p < 0.0005), neutral steroids (p < 0.005), and net elimination of cholesterol (p < 0.0005), respectively. Cholesterol and fat absorption and plasma plant sterols were significantly enhanced between 8 and 14 weeks after autotransplantation (p < 0.05, p < 0.005, and p < 0.05, respectively), whereas fecal elimination of cholesterol remained increased until the end of the follow-up. CONCLUSIONS: Autotransplantation of the ileum in pigs that have undergone proximal small bowel resection disturbs the adaptive absorption of cholesterol, bile acids, fat, and fat-soluble vitamins, resulting, through increased fecal elimination of cholesterol, in decreased serum cholesterol despite a marked compensatory increase in cholesterol synthesis.

Animals

How to diagnose chronic rejection. A study in porcine intestinal allografts.

Porcine small bowel allografts were followed for 18 weeks during immunosuppression with cyclosporine-A (CyA), azatioprine and prednisone. The mucosal alterations noted at the 12th week were epithelial vacuolation and loss of Goblet cells. Moderate infiltration of inflammatory cells, mainly lymphocytes, was found in the lamina propria. In addition, a few grafts exhibited oedema and fibrosis. Vessels already showed endothelial swelling and intimal proliferation at the 12th week. In the submucosa, the infiltration of inflammatory cells was not present till the 18th week. Further changes in the mucosa at the 18th week were the blunting of villi, cuboidal epithelium, crypt abscesses and epithelial atrophy. The histological alterations of mucosa and lamina propria existing in the full thickness biopsies were mostly also detectable in mucosal biopsies, provided that multiple biopsies were taken. Thus these parameters analyzed from mucosal biopsy material are suitable for the diagnosis and monitoring of chronic small bowel rejection. In autopsy, the most prominent features were in the mesenterial arteries: intimal proliferation, vasculitis, proliferation of media and endothelial alterations. The activity of the mucosal disaccharidases maltase and sucrase remained near the initial level till the 12th week and had decreased markedly by the 18th week.

Abscess

Urinary trypsinogen-2 test strip in detecting ERCP-induced pancreatitis.

BACKGROUND AND STUDY AIMS: We have evaluated a new urinary trypsinogen-2 test strip, based on the principle of immunochromatography, in the diagnosis of acute pancreatitis induced by endoscopic retrograde cholangiopancreatography (ERCP). PATIENTS AND METHODS: One hundred six consecutive patients undergoing ERCP (with opacification of the pancreatic duct) at the Helsinki University Central Hospital were included in the study. Patients were tested with a urinary trypsinogen-2 test strip six hours after ERCP. Quantitative trypsinogen-2 as well as serum and urine amylase values were measured before the procedure and six hours after it. RESULTS: In patients developing pancreatitis after ERCP, the median urinary trypsinogen-2 concentration six hours after the endoscopic procedure was 1780 micrograms/l (range 29-10,700 micrograms/l), and in patients without pancreatitis the median concentration was 3.6 micrograms/l (range 0.1-3390 micrograms/l; P < 0.0001). The sensitivity and specificity figures for the urinary trypsinogen-2 test strip results in diagnosing post-ERCP pancreatitis were comparable (81% and 97%, respectively) to those for serum amylase (91% and 96%) and urine amylase measurements (81% and 95%). The test strip showed a good correlation (kappa = 0.75) with the quantitative trypsinogen-2 assay. CONCLUSIONS: The increase in urinary trypsinogen-2 concentration after ERCP reflects pancreatic injury, and can be detected by the test strip. Patients should be tested before the ERCP procedure as well, since elevated baseline values occur. The test is reliable and easy to perform even on an outpatient basis. However, its clinical usefulness requires evaluation in further trials.

Acute Disease

Increased serum trypsinogen 2 and trypsin 2-alpha 1 antitrypsin complex values identify endoscopic retrograde cholangiopancreatography induced pancreatitis with high accuracy.

AIMS: To evaluate the clinical utility of two new tests for serum trypsinogen 2 and trypsin 2-alpha 1 antitrypsin complex (trypsin 2-AAT) in diagnosing and assessing the severity of acute pancreatitis (AP) induced by endoscopic retrograde cholangiopancreatography (ERCP). PATIENTS: Three hundred and eight consecutive patients undergoing ERCP at Helsinki University Central Hospital in 1994 and 1995. METHODS: Patients were followed prospectively for pancreatitis and clinical outcome. They were tested for serum trypsinogen 2, trypsin 2-AAT, and amylase in samples obtained before and one, six, and 24 hours after ERCP. RESULTS: Pancreatitis developed in 31 patients (10%). Their median serum trypsinogen 2 increased 26-fold to 1401 micrograms/l at six hours after the procedure and trypsin 2-AAT showed an 11-fold increase to 88 micrograms/l at 24 hours. The increase in both markers was stronger in severe than in mild pancreatitis, and in patients without pancreatitis there was no significant increase. Baseline trypsinogen 2 and trypsin 2-AAT concentrations were elevated in 29% and 32% of patients, respectively. The diagnostic accuracy of a threefold elevation over the baseline value was therefore analysed. The sensitivity and specificity of these parameters in the diagnosis of post-ERCP pancreatitis was 93% and 91%, respectively, for serum trypsinogen 2 at six hours after the examination, and 93% and 90%, for trypsin 2-AAT at 24 hours. CONCLUSIONS: Serum trypsinogen 2 and trypsin 2-AAT reflect pancreatic injury after ERCP. High concentrations are associated with severe pancreatic damage. The delayed increase in trypsin 2-AAT compared with trypsinogen 2 appears to reflect the pathophysiology of AP. A greater than threefold increase in trypsinogen 2 six hours after ERCP is an accurate indicator of pancreatitis.

Acute Disease

Ileal nutritional function after one-stage orthotopic ileum transplantation in the growing pig: reversal of lethal short bowel syndrome.

Intestinal isolation is associated with hypoplasia of defunctioned mucosa and reduction in the segmental absorption, whereas the presence of luminal nutrition is essential for the expression of the ileal adaptive response after proximal small bowel resection. On the other hand, intensive postoperative graft monitoring is obligatory because of the disastrous consequences of small bowel graft rejection. Thus, the authors sought to develop an experimental ileum transplantation model that provided immediate graft placement in bowel continuity, together with readily available graft monitoring connection through a proximal Roux-en-Y enterostomy. Four groups of pigs were prepared: RESTX (n = 9), proximal 50% small bowel resection with simultaneous orthotopic ileum autotransplantation; RES (n = 7), proximal 50% small bowel resection; NONRES (n = 6), transection; and SB (n = 5), short bowel. Early (1 to 4 weeks) and long-term (5 to 12 weeks) studies of animal growth, nutritional status, disaccharide absorption, water and electrolyte balances, and liver function were performed after ileum autotransplantation (IAT) in relation to small intestine of variable length with undivided mesentery (intact neural and lymphatic connections). The perioperative transplantation mortality rate remained at about 10%. Reasons not related to the transplantation procedure accounted for the late complication rate of 38%. In the ileum autotransplantation (RESTX) group, weight gain was recovered 2 to 3 weeks after transplantation, and the mean weight reached the preoperative level at 5 weeks. The SB pigs underwent progressive weight loss. The transection (NONRES) and proximal resection (RES) animals gained weight at similar rates. IAT had no effect on the plasma protein concentrations. Proximal resection, with or without IAT, was associated with depressed plasma cholesterol contents in the early period. Plasma cholesterol levels amended long-term, after both IAT and proximal resection. IAT resulted in deficient intraluminal processing of maltose, whereas isolated proximal resection tended to enhance disaccharide absorption early after the surgery. The short bowel pigs were not able to preserve sufficient nutritional status, and demonstrated a marked decline in the hemoglobin, protein, and cholesterol levels. No biochemical signs suggestive of potential liver damage caused by portocaval graft vascularization were recognized. These findings suggest that one-stage ileum autotransplantation provides sufficent absoprtive capacity to reverse otherwise lethal short bowel syndrome in the growing pig. However, transplantation disturbs the in vivo absorptive function of the nonrejecting ileum. Long-term impairment in disaccharide absorption may be partially related to an altered intestinal adaptive response secondary to proximal resection when combined with simultaneous transplantation. The authors developed this ileal small bowel transplantation model using rapidly growing pigs, wherein body weight gain represents an objective parameter of intestinal absorptive function. Only this type of animal model can yield clinically relevant data in the evaluation of a transplant's ability to provide sufficient nutritional function in a growing recipient.

Age Factors

Cholesterol absorption and synthesis after autotransplantation of porcine ileum.

BACKGROUND: Cholesterol, long-chain fatty acids, and fat-soluble vitamins are absorbed mainly in the upper small intestine and bile acids in the terminal ileum. This study determined the consequences of ileal autotransplantation on cholesterol metabolism, plasma fatty acids, and vitamin A absorption. METHODS: Plasma lipids, cholesterol precursors, plant sterols, cholestanol, fatty acids, vitamin A absorption, and animal growth were studied for 3 months after transection (n = 5), jejunal (50%) resection (n = 7), jejunal (50%) resection combined with orthotopic ileal autotransplantation (n = 7), and enterectomy (n = 7). RESULTS: Cholesterol precursor to cholesterol proportions in plasma (reflect cholesterol synthesis) remained unchanged after transection and jejunal resection. The plasma plant sterol proportions (reflect cholesterol absorption) and retinol absorption increased after transection and less significantly after jejunal resection, whereas plasma fatty acid compositions were virtually unchanged. Transplantation of ileum and enterectomy amended up to sixfold the precursor proportions (p < 0.05 versus transection or jejunal resection) and impaired body weight gain. The plant sterol proportions, vitamin A absorption, and plasma cholesterol levels, respectively, were significantly (p < 0.05) decreased after transplantation when compared with those of the transected control group but remained markedly higher than those in the enterectomized group. Linoleic acid was significantly (p < 0.05 versus transection) decreased, whereas monoenoic fatty acids and eicosatrienoic acid were increased (p < 0.05 versus jejunal resection) in plasma lipids. CONCLUSIONS: These results indicate that autotransplantation of ileum in pigs that have undergone jejunectomy impairs sterol, essential fatty acid, and vitamin A absorption so that plasma cholesterol levels decrease despite markedly increased cholesterol synthesis and that these changes clearly exceed those found after jejunal resection alone.

Animals

Brush border enzymes in evaluation of acute small bowel rejection.

The change in activity of three disaccharidase enzymes (maltase, sucrase and lactase) was determined according to the method of Dahlqvist during acute rejection in non-immunosuppressed piglet small bowel grafts. In addition, two brush border enzymes, lactase and aminopeptidase, were stained with monoclonal antibodies. Diminishing disaccharidase activity was an early event during rejection. Diminution began 2 days before distinct morphological changes were seen in the mucosal biopsies. Evaluation of disaccharidase activity can thus be used as a confirmatory method in detecting rejection. Reduction in immunohistological staining of lactase and aminopeptidase with monoclonal antibodies and changes in mucosal morphology were observed to progress simultaneously.

Animals

Adaptation of cholesterol absorption after proximal resection of porcine small intestine.

Cholesterol absorption occurs primarily in the upper small intestine. Our aim was to assess absorption of cholesterol during ileal adaptation after proximal small intestinal resection. In vivo absorption and elimination of cholesterol, plasma cholesterol, cholesterol precursors, and plant sterols were related to intestinal morphology and transit 4 (n = 5), 8 (n = 5), and 14 (n = 5) weeks after a 75% proximal resection of porcine small intestine, and compared to preoperative (n = 5) and transected (n = 5) control animals. Fractional cholesterol absorption, the daily amount of cholesterol absorbed, plasma cholesterol, and plant sterol to cholesterol proportions were significantly (P < 0.05 or less) decreased, whereas fecal loss of cholesterol as neutral steroids, less so as bile acids, plasma cholesterol precursor proportions, and ileal mass and villus height were significantly increased (P < 0.05 or less) after 8 weeks of the resection. Cholesterol absorption efficiency, decreased by the resection, was gradually increased from 5.4 +/- 2.2 to 26.9 +/- 3.9% during the 14 postoperative weeks (P < 0.0001) simultaneously with a 46% increase in villus height compared with transection (P < 0.0001), but absorption remained still below control levels (80.4 +/- 2.5%, P < 0.0001). In resected and control animals, villus height correlated positively with cholesterol absorption efficiency (r = 0.85, P < 0.0001; r = 0.76, P = 0.01) and plasma plant sterol proportions (r = 0.94-0.95, P < 0.0001; r = 0.78-0.85, P < 0.008), respectively. In conclusion, after massive proximal small bowel resection, adaptation of intestinal cholesterol absorption efficiency occurs in the distal ileum closely parlleling villus hypertrophy.

Adaptation, Physiological