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R Andersson

Publications and source records attributed to R Andersson.

At least 163 records · Page 9Linked to original sources
PubMed1995

The influence of abdominal sepsis on acute pancreatitis in rats: a study on mortality, permeability, arterial pressure, and intestinal blood flow.

Bacterial infection increases mortality and morbidity in acute pancreatitis. The aim of the present study was to analyze possible mechanisms by which bacterial infectious complications may worsen the course of the disease. Systemic arterial pressure, mucosal microcirculation, and intestinal, peritoneal, and pulmonary permeability of 125I-labeled human serum albumin were measured 3, 6, 12, 24, 48, and 72 h after sham operation, induction of pancreatitis (AP), abdominal sepsis (AS), or AP+AS. The mortality rate at 48 and 72 h was 33% in AS and 58 and 75%, respectively, in AP+AS, whereas there were no deaths in the AP or sham-operated groups. The systemic arterial pressure and intestinal blood flow decreased early in all study groups, with the lowest values for AP+AS. Bacterial infection aggravated the increase in intestinal, peritoneal, and pulmonary permeability to labeled albumin in pancreatitis. This was true for both intestinal endothelial permeability (blood to tissue) and mucosal barrier permeability (blood to lumen). The findings demonstrate the occurrence of circulatory failure and changes of the capillary barrier in multiple organs in acute pancreatitis. Moreover, the changes were aggravated by an intraabdominal septic challenge. The observations imply that bacterial infection may play a role in the development of multiple organ failure in acute pancreatitis, tentatively by aggravating alterations in tissue barrier function.

Abdomen↗
PubMed1995

T-cell receptor J beta gene segment usage in immature and mature human thymocytes.

Immature double positive (DP, CD4+CD8+) and mature single positive (SP, CD4+CD8- and CD4-CD8+) human thymocytes from nine thymi were analysed for their complete patterns of relative TCR J beta multigene member usage in relation to six rearranged V beta family exons (V beta 5.1, 6.1-3, 8, 9, 12 and 18). Each sample tested contained mRNA transcripts corresponding to all potential V beta(D beta)J beta combinations. Individual J beta gene segments were expressed in a similar, highly non-random manner both in SP and DP thymocytes, irrespective of original genomic position of the individual associated V beta exon. In addition, ranges of family usage and frequency of individual over-representations of J beta gene segments, as determined in DP and SP thymocyte populations, displayed no significant differences. Upon comparison of DP and SP thymocytes, however, a discrepancy in one aspect of J beta gene utilization was established: decreasing J beta family 1/J beta family 2 ratios were determined to be positively correlated with increasing maturity of thymocytes, a condition further supported by data previously obtained from studies of PBL T cells. At the individual J beta gene level, the observed gradual modification of the relative family usage can largely be explained by a significant shift from a higher J beta 1.1/J beta 2.7 ratio in DP to a higher J beta 2.7/J beta 1.1 ratio in SP thymocytes. Altogether, the present results imply that selectional processes in the thymus appear to have only minor consequences on the distribution pattern of expressed J beta exons. Hence, the disproportionate pattern of TCR J beta gene usage seems to be established mainly at the recombinatorial level followed by minor adjustments during thymic and post-thymic events.

Cell Differentiation↗
PubMed1995

Determination of lactate dehydrogenase activity and urea content in milk by dry chemistry.

Comparison of the new technique of dry chemistry (EKTACHEM 700-XR, Eastman Kodak Co., USA) with conventional wet chemistry (HITACHI 717, Boehringer Mannheim, Germany) for quantitations of lactate dehydrogenase activity and urea content in bovine milk resulted in correlation coefficients of more than 0.9 even when measuring fresh raw milk by dry chemistry.

Animals↗
PubMed1995

Endothelial barrier resistance in multiple organs after septic and nonseptic challenges in the rat.

Local variations in endothelial permeability, hypothesized to play a role in the development of multiple-organ injury, were measured by 125I-labeled human serum albumin flux and leakage index in rats with a variety of challenges. The albumin flux significantly increased in the peritoneum, pancreas, stomach, and liver in acute pancreatitis; in the peritoneum and liver in abdominal sepsis; in the spleen, proximal small intestine, colon, liver, lungs, heart, and muscle in bacteremia; in the kidneys, liver, lungs, heart, brain, and muscle in endotoxemia; and in the peritoneum, proximal small intestine, colon, kidneys, liver, and heart after bradykinin administration. A redistribution of the tissue blood content, measured by 51Cr-labeled red blood cells, was noted. An increased albumin leakage index, assaying endothelial permeability considering local hemodynamic alterations, was noted in various organs in the different experimental groups. Thus septic and nonseptic challenges induce endothelial barrier injury. The endothelial resistance appears to be organ and/or tissue dependent and associated with a redistribution of blood.

Abdominal Abscess↗
PubMed1995

Effect of bile obstruction on liver regeneration following major hepatectomy: an experimental study in the rat.

The regeneration of the liver following resection is regulated by a variety of factors and it might be expected that jaundice influences the process. We therefore evaluated the regenerative response to major hepatectomy in bile-obstructed rats. Two weeks after ligation of the common bile duct, a standardized 77% hepatectomy was undertaken. The jaundiced animals showed an augmented liver regeneration compared to nonjaundiced individuals (p < 0.01). However, blood clearance of radiolabelled Escherichia coli bacteria was impaired (p < 0.01) in animals with bile obstruction at 7 days after the hepatectomy, accompanied by reduced bacterial uptake in the liver as a sign of impaired reticuloendothelial system function.

Animals↗
PubMed1995

The role of oral administration of oatmeal fermented by Lactobacillus reuteri R2LC on bacterial translocation after acute liver failure induced by subtotal liver resection in the rat.

BACKGROUND: Previous experimental studies showed that a disturbed ecology of the enteric bacterial population might contribute to the occurrence of bacterial translocation from the gut in acute liver failure (ALF). METHODS: In the present study the effects of oral administration of exogenous Lactobacillus reuteri R2LC and oat fiber on bacterial overgrowth and translocation and on enterocyte protein contents were investigated in rats with ALF induced by subtotal liver resection. The oatmeal soup base was anaerobically inoculated with L. reuteri R2LC and fermented for 15 h. The animals were then fed with fermented or unfermented oatmeal or saline daily for 6 days before the experimental procedure. RESULTS: The incidence of bacterial translocation to the systemic circulation was nil and 17% in rats subjected to sham operation with saline or 90% hepatectomy with fermented oatmeal, respectively, and 80-90% and 34-50% in rats subjected to hepatectomy with saline or unfermented oatmeal. One rat treated with fermented oatmeal had positive bacterial growth in mesenteric lymph nodes (MLN), which was significantly lower than in hepatectomized rats with saline or unfermented oatmeal (80-100% and 50-67%). No significant differences was demonstrable between hepatectomized animals with oral administration of fermented or unfermented oatmeal as compared with sham-operated rats. The number of anaerobic bacteria, Gram-negative anaerobes, and Lactobacillus decreased significantly, and the number of Escherichia coli increased in the distal small intestine and colon in hepatectomized animals with saline or unfermented oatmeal, as compared with animals subjected to sham operation or hepatectomy with fermented oatmeal. CONCLUSIONS: The occurrence of bacterial translocation from the gut in 90% hepatectomy-induced ALF could be prevented by fermented oatmeal, which implies possibilities for biologically balancing the enteric bacterial ecology.

Animals↗
PubMed1995

Experimental foreign-body infection in the biliary tract in rats.

BACKGROUND: Biomaterials used for biliary drainage may potentially result in biomaterial-associated infections. METHODS: Foreign-body infection in the biliary tract was investigated in rats. Rubber drain pieces were implanted in the biliary tract in rats for 1-4 weeks, followed by challenges with 10(2) to 10(4) colony-forming units (cfu) Escherichia coli injected into the common bile duct. The rate of infection was calculated, the bacterial growth in the biliary tract was observed over 72 h after challenges, and the opsonic activity in bile and in sera was assessed. RESULTS: In the group with drain material, inocula as small as 10(2) cfu produced persisting infection in the common bile duct in 90% of animals, whereas the same number of E. coli infected only 30% of rats in the control and sham implantation groups (p < 0.01, chi-square test). Complement-mediated opsonic activity in bile of animals with implanted drain pieces gradually decreased with time, whereas opsonic activity in sera from the same animals remained unchanged. CONCLUSIONS: Implants in the biliary tract impair local host defense, resulting in an increased susceptibility to microbial infection.

Animals↗
PubMed1995

Antioxidant and calcium channel blockers counteract endothelial barrier injury induced by acute pancreatitis in rats.

BACKGROUND: Multiple organ failure is the major mortality-related complication in severe acute pancreatitis. Endothelial barrier injury may be involved in its pathophysiology. METHODS: The present study evaluated alterations in endothelial barrier integrity in different organs/tissues 12 h after induction of acute pancreatitis by intraductal infusions of bile. Potential effects of oxygen free radicals and calcium influx were evaluated by pretreatment with an antioxidant, N-acetyl-L-cysteine, and calcium channel antagonists, verapamil and diltiazem. RESULTS: Tissue edema, reflected by an increase in tissue water content, was noted in the stomach, proximal small intestine, cecum, spleen, pancreas, kidneys, liver, lungs, heart, and brain in rats with pancreatitis. Also, an increased endothelial barrier permeability, as evidenced by the leakage of radiolabeled human serum albumin from blood to tissues, occurred in the stomach, proximal small intestine, colon, peritoneum, spleen, pancreas, kidneys, liver, lungs, and heart, accompanied by altered liver functions, increased levels of pancreatic enzymes, compromised renal function, and delayed intestinal motility. N-acetyl-L-cysteine prevented tissue edema and endothelial permeability changes in most organs/tissues, whereas the effects of verapamil and diltiazem were less marked. The preventive effects occurred in an organ-dependent manner. CONCLUSIONS: Endothelial barrier injury is found in all investigated organs/tissues in acute experimental pancreatitis. Oxygen free radicals and calcium influx may play a role in the development of these changes.

Acetylcysteine↗
PubMed1995

The effects of transplantation of hepatocytes cultured with insulin on acute liver failure induced by 90% hepatectomy in the rat.

OBJECTIVE: To evaluate the influence of transplantation of hepatocytes either not cultured or cultured with or without insulin on survival in rats with acute liver failure induced by 90% hepatectomy. DESIGN: Randomized laboratory experiment. SETTING: University department, Sweden. MATERIAL: 60 Adult male Sprague-Dawley rats, not including donors. INTERVENTIONS: 90% hepatectomy without hepatocyte transplantation, or with intrasplenic transplantation of: uncultured hepatocytes immediately after resection, or uncultured hepatocytes one or three days before resection, or hepatocytes cultured with or without insulin immediately after resection (n = 10 in each group). MAIN OUTCOME MEASURES: Cell viability, attachment ability, survival, liver function, and body weight. RESULTS: Transplantation of hepatocytes cultured for 3 days without insulin or of uncultured hepatocytes one day prior to hepatectomy did not significantly improve 30-day survival compared with uncultured hepatocyte transplantation immediately after hepatectomy. Hepatocytes cultured with insulin for 3 days and transplanted immediately after hepatectomy significantly improved survival compared with animals in which hepatocytes were transplanted either uncultured or cultured for 3 days without insulin immediately after hepatectomy. Hepatocyte transplantation 3 days before hepatectomy further increased survival compared with the other groups in which transplantation was done immediately after hepatectomy. Acute failure, acute compensatory, and late 'enhanced' phases were defined within 30 days of hepatectomy. CONCLUSION: Transplantation of hepatocytes that are cultured with hepatocellular trophic factors (for example insulin) before transplantation may have the potential to increase the effectiveness of transplanted hepatocytes in the treatment of acute liver failure.

Analysis of Variance↗
PubMed1995

Genetic restriction and specificity of the immune response in mice to fusion proteins containing repeated sequences of the Plasmodium falciparum antigen Pf155/RESA.

The genetic restriction and specificity of the immune response in mice to two fusion proteins, ZZ-M3 and ZZ-M5, were studied. These proteins contain two IgG-binding domains (ZZ) from staphylococcal protein A, and repeated sequences from the C-terminal [(VEHDAEEN)5 (VEEN)10] (M3) or central [(VEEPTVADDEH)3(VEEPTVAEEH)2] (M5) regions of the Plasmodium falciparum malaria blood stage antigen Pf155/RESA. Strong antibody and T-cell responses to M3 and M5 were linked to expression of the I-Ak allele, and T-cell responses to the bacterial fusion partner ZZ were restricted to mice of the H-2k haplotype. The response to M5 was less restricted than that to M3, giving intermediate responses in mice of H-2d haplotypes as well. However, ZZ-M5-primed lymph node (LN) cells from these mice were primarily induced to proliferate in vitro by the complete ZZ-M5 construct and not by synthetic peptides representing the repeated subunits in M5. The reactivity with intact Pf155/RESA in erythrocyte membrane immunofluorescence was weak of antisera from mice immunized with ZZ-M5, whereas the reactivity of antisera from mice immunized with ZZ-M3 roughly paralleled their reactivity with M3 in an enzyme-linked immunosorbent assay (ELISA). The antibody responses induced by immunization with ZZ-M3 or ZZ-M5 were specific for M3 or M5, respectively, while activated T cells displayed cross-reactivity between M3 and M5 in an in vitro proliferation assay. The results indicate that the assembly of repeated sequences in fusion proteins affects both the MHC class II restriction and the specificity of the induced antibody and T-cell responses.

Amino Acid Sequence↗
PubMed1995

Use of fundal height as a proxy for length of gestation in rural Africa.

Lack of information on the date of the last menstrual period is a common problem in antenatal care in developing countries. The aim of this study was to see whether the fundal height can be used as a proxy for the length of gestation. A graph representing the expected remaining time to delivery was constructed from fundal height measurements in 7790 pregnant women delivered in a rural African hospital from 1970 to 1988. The graph was used to predict the probable week of delivery in 604 pregnant women giving birth to a singleton child in 1989. The mean deviation of the actual week of delivery from the predicted week was -0.6 (s.d. 3.4) weeks. In 270/604 cases (45%) delivery occurred within 2 weeks of the predicted week. Birthweight and perinatal mortality were strongly related to the deviation from the predicted week of delivery. The majority of perinatal deaths (34/50, 68%) occurred in children delivered early. The fundal height, as measured by paramedicals in routine antenatal care in rural Africa, may be used as a proxy for the length of gestation when the date of the last menstrual period is not known.

Birth Weight↗
PubMed1995

Giant cell arteritis.

Whereas giant cell arteritis (GCA) was considered a rare disease 50 years ago, the generalized arteritis is now recognized as an important and significant cause of morbidity in elderly people; its cause and pathogenesis is poorly understood. Glucocorticosteroids are the drug of choice in all clinical types of GCA. In contrast to corticosteroids, nonsteroidal anti-inflammatory drugs have no proven effect on vascular complications to GCA, and cannot be recommended.

Adrenal Cortex Hormones↗
PubMed1994

Indications for operation in suspected appendicitis and incidence of perforation.

OBJECTIVE: To clarify poorly understood epidemiological features of appendicitis. DESIGN: Retrospective study of consecutive cases from a defined population and analysis of data from published studies. SETTING: County of Jönköping, Sweden. 3029 patients who underwent operation in 1984-9 and 4717 patients from the county town who underwent operation in 1970-89, all for suspected appendicitis, plus 48,426 cases from six reported studies. MAIN OUTCOME MEASURES: Incidences specific for age and sex and temporal trends of perforating and non-perforating appendicitis and removal of a normal appendix. Associations between diagnostic accuracy, rate of perforation, and incidences of removal of a normal appendix and of perforating and non-perforating appendicitis. RESULTS: The incidence of appendicitis was 116/100,000 inhabitants. Appendicitis was more common in male patients. The incidence of perforating appendicitis was independent of age, stable over time, and uninfluenced by the rate of laparotomy, whereas the incidence of non-perforating appendicitis was age dependent, decreasing over time, and related to the diagnostic accuracy and rate of removal of a normal appendix. CONCLUSIONS: Perforating and non-perforating appendicitis seem to be separate entities, and appendicitis that resolves spontaneously is common. This may have important implications for managing suspected appendicitis.

Adolescent↗
PubMed1994

CD4+ and CD8+ T cell expansions using selected TCR V and J gene segments at the onset of giant cell arteritis.

OBJECTIVE: To investigate T cell receptor (TCR) V alpha/V beta (and in selected cases, J beta) usage in CD4+ and CD8+ peripheral blood lymphocytes of patients with giant cell arteritis (GCA), before and after treatment, as well as to analyze the HLA types of these patients. METHODS: Flow cytometry, with 10 anti-TCR V-specific monoclonal antibodies (MAb), was used. To analyze J beta usage by cell populations expressing certain V beta, we used the polymerase chain reaction (PCR) technique, with V beta- and C beta-specific primers, Southern blotting of PCR products, and subsequent hybridization with radiolabeled J beta-specific probes. HLA typing was performed using the microlymphocytotoxicity technique. RESULTS: Seven of the 9 GCA patients had increased anti-TCR V MAb reactivities (interpreted as T cell expansions), which in many cases, correlated with clinical signs of disease. A strict preference for particular J beta segments was found in 3 of 3 expanded CD4+ T cell populations. CONCLUSION: T lymphocytes expressing specific antigen receptors are implicated in the pathogenesis of GCA.

Aged↗
PubMed1994

Bacterial translocation, intestinal ultrastructure and cell membrane permeability early after major liver resection in the rat.

The process and route of bacterial translocation from the gut after major liver resection remain unclear. In the present study enteric bacterial translocation, enterocyte ultrastructure in the ileum and colon, the process and route of bacterial invasion and the permeability of the cell membrane system and blood-tissue barrier were evaluated in rats receiving sham operation, and 70 or 90 per cent hepatectomy. The incidence of bacterial translocation to mesenteric lymph nodes was 80-100 per cent in rats 6 h after 70 per cent and 2-4 h after 90 per cent hepatectomy, and 80-100 per cent to the systemic circulation 2-4 h after 90 per cent hepatectomy but only 20 per cent to the portal vein. An increase in bacterial adherence to the intestinal surface, damage to the permeability of the cell membrane system and blood-tissue barrier, and pathological alterations in the ileum and colon developed, correlating with the extent of liver removed and the time that had passed after hepatectomy. Most translocating bacteria appeared in morphologically intact enterocytes with increased membrane permeability, in antigen-presenting cells and in submucosal lymphatics, but some bacteria were also seen within damaged enterocytes 4h after 90 per cent hepatectomy. These results indicate that altered permeability of the cell membrane system may be one of the earliest characteristics of challenged enterocytes, and that enteric bacteria translocate through both morphologically normal and abnormal enterocytes. Translocation occurred mainly into the lymphatics, bacteria either being 'carried' by antigen-presenting cells or entering by active invasion.

Animals↗