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Biomedical subjects

R Andersson

Publications and source records attributed to R Andersson.

At least 145 records · Page 8Linked to original sources
PubMed1996

A bacteriologic and scanning electron microscope study after implantation of foreign bodies in the biliary tract in rats.

BACKGROUND: Bacterial adherence to the stent surfaces, concomitant colonization, and possible stent blockage are the main complications after the use of biliary stents. The present study was assigned to investigate bacteriologic and morphologic changes in the biliary tract after the implantation of biliary drain materials. METHODS: Rubber and silicone pieces with a surface area of 1 cm2 were implanted into the biliary tract in rats after temporary obstruction of the common bile duct by the use of a mini-occluder. The animals were killed at 4, 8 and 14 weeks, respectively, after implantation, and the implants were retrieved, cultured, and examined by scanning electron microscopy (SEM). Bacterial culture and SEM were also performed on tissue samples obtained from the mucosal surface of the biliary tract. RESULTS: Bacterial colonization and biofilm formation were found on the surfaces of the implanted materials and on the mucosal surface of the biliary tract in animals with implants but not on the biliary tract mucosa in rats without implants. CONCLUSION: Foreign bodies implanted in the biliary tract facilitate bacterial adherence not only to the surface of the implants but also to the mucosal surface in the biliary tract.

Animals↗
PubMed1996

A community intervention program targeting the elderly in Stockholm county.

Each year, about 11,000 individuals are hospitalized in the County of Stockholm for the treatment of fall injuries. This includes 15 percent of the population 65 years or older. In the County of Stockholm, an intervention program has begun which targets the elderly. The long-term objective is to develop a permanent community safety program for the elderly. A pilot study will be implemented in the municipality of Sundbyberg, a suburb of Stockholm. The pilot study is being conducted in conjunction with the local public health service. The objective is to reduce the number of fall incidents among the elderly. The program involves registration of injuries, study circles concerning health issues for the elderly, the training of personnel within the health professions, and improving the physical environment in residential areas. To obtain generalizable knowledge, the program includes evaluation of outcome effects and process studies.

Accidental Falls↗
PubMed1996

Overexpression of select T cell receptor V beta gene families within CD4+ and CD8+ T cell subsets of myasthenia gravis patients: a role for superantigen(s)?

BACKGROUND: The principal symptoms of myasthenia gravis (MG), muscle weakness and fatigue due to impaired neuromuscular transmission, are caused by autoantibodies to the muscle nicotinic acetylcholine receptor (AChR). The mechanisms underlying the autoimmune response, however, appear to be initiated by activation of specific HLA class II-restricted CD4+ T lymphocytes. Thus, central to elucidating the causation of MG is determining how T cells are recruited to contribute to misguided immunological assaults on the major autoantigenic target, AChR. MATERIALS AND METHODS: By combining a polymerase chain reaction (PCR)-based strategy and Southern blot technique, we have analyzed the frequency of expression of 22 individual T cell receptor (TCR) V beta gene subfamilies in CD4+ and CD8+ peripheral blood T cell subsets derived from eight MG patients and seven healthy controls. The quantification of relative usage of individual TCR J beta gene segments was performed by hybridization of PCR-amplified products (specifically V beta 1-C beta) with a complete panel of 32P-5'-end-labeled J beta-specific oligonucleotide probes, followed by scanning analysis of autoradiographs. RESULTS: Comparisons of data obtained from V beta analyses of T cells from MG patients with those from healthy individuals established that MG patients significantly overexpressed V beta 1, V beta 13.2, V beta 17, and V beta 20 gene family members within both CD4+ and CD8+ T cell subpopulations. Moreover, analysis of the relative utilization of individual TCR J beta gene segments in V beta 1+/CD4+ and V beta 1+/CD8+ T lymphocytes revealed distribution patterns in patients indistinguishable from those recorded in the corresponding cell subsets derived from controls. CONCLUSIONS: T lymphocytes from MG patients displayed a biased overexpression of four TCR V beta gene segments: V beta 1, V beta 13.2, V beta 17, and V beta 20. The relative frequencies of association of individual V beta 1 (D beta) J beta combinations revealed that J beta gene usage in the V beta 1-over-represented T cell subsets had normal distribution patterns. It can thus be deduced that J beta gene segment products appear not to have a selective effect on the process leading to overexpression of V beta 1 exons in MG patients. Hence, our observations suggest a possible role for superantigen(s) in the T cell activation in MG patients.

Adult↗
PubMed1996

Implantation metastases from gastrointestinal cancer after percutaneous puncture or biliary drainage.

OBJECTIVE: Evaluation of incidence and outcome of implantation metastases after percutaneous fine-needle biopsy or biliary drainage. DESIGN: Retrospective study. SETTING: University hospital, Sweden. SUBJECTS: Eight patients with implantation metastases from gastrointestinal cancers after percutaneous fine-needle biopsy (n = 7) or biliary drainage (n = 1). MAIN OUTCOME MEASURES: Incidence of implantation metastases, treatment and influence on outcome and survival. RESULTS: In two out of three patients who had had otherwise radical operations, the implantation metastases meant that the operations were palliative rather than curative. Patients who had had palliative resections of the implantation metastases developed major local complications. One patient is alive with no signs of disease after 106 months, while one is alive with disease 30 months after the diagnosis of the implantation metastases. The remaining patients have died after 6 to 23 months. CONCLUSION: The incidence of implantation metastases after fine-needle procedures is probably underestimated. There is a slight but definite risk that the procedure may render an otherwise curative resection palliative. Implantation metastases cause local complaints of varying severity and seems to have a tendency to recur locally. We recommend that fine-needle biopsy should be restricted to patients who will truly benefit from a more accurate preoperative diagnosis.

Adult↗
PubMed1995

Bacterial translocation and intestinal capillary permeability following major liver resection in the rat.

Bacterial infections constitute a major cause of morbidity and mortality after major liver resection and mechanisms of this type of complication have been poorly understood. The present study evaluated the translocation of enteric bacteria to mesenteric lymph nodes, viscera, and the systemic circulation and gut capillary permeability of a fine ultrastructural tracer in rats subjected to sham hepatectomy or 70% hepatectomy. Furthermore, the preventive effects of water-soluble ethylhydroxyethyl cellulose (EHEC) were studied. Cultures of all samples from rats subjected to sham hepatectomy or 70% hepatectomy with preoperative intravenous administration of EHEC were bacteriologically negative. The incidence of bacterial translocation from the gut to the systemic circulation and mesenteric lymph nodes was 30 and 80%, respectively (P < 0.01), and to the liver and kidneys 50 and 40%, respectively (P < 0.05), 12 hr after 70% hepatectomy. Intestinal capillary permeability and endothelial cell membrane permeability increased with the development of bacterial translocation. Translocating bacteria appeared within the cytoplasm of capillary endothelial cells. EHEC restored the changes in gut capillary permeability induced by major liver resection. These results indicate that gut capillary permeability may play an important role in maintaining the integrity of the gut barrier function and that increased permeability may be associated with the development of gut barrier failure.

Animals↗
PubMed1995

Alterations of lipid contents in blood, hepatocytes, and enterocytes in the early stage of acute liver failure induced by 90% hepatectomy in the rat.

Potential alterations in lipid metabolism in the early stage of acute liver failure are poorly elucidated. In the present study, acute liver failure was induced by subtotal hepatectomy (90%) in the rat in order to investigate early alterations in lipid contents in blood, hepatocytes, and enterocytes. Hypocholesterolemia and hypotriglyceridemia appeared 2 and 6 hr following subtotal hepatectomy. Plasma levels of high density lipoprotein-cholesterol were significantly lower in rats with acute liver failure than in controls, which may be associated with hypocholesterolemia. An increase in erythrocyte phospholipids and triglycerides was seen from 2 hr on after hepatectomy. The content of phospholipids and triglycerides was reduced in isolated enterocytes from the proximal small intestine and increased in enterocytes from the distal small intestine. Isolated hepatocytes from the remnant liver exhibited an increase in phosphatidylethanolamine and a decrease in phosphatidylinositol. Levels of enterocyte phosphatidylserine were elevated in both the proximal and the distal small intestine, while they diminished in the distal small intestine. Sphingomyelin content increased in the proximal small intestine. The recognition of lipid alterations in the intestine-liver-systemic circulation axis in the early stage of acute liver failure may be beneficial in improving the recovery from acute liver failure.

Animals↗
PubMed1995

Fibronectin on the surface of biliary drain materials--a role in bacterial adherence.

The present study deals with the demonstration of deposited fibronectin (Fn) on the surfaces of implanted biliary drain materials and the role of deposited Fn in promotion of bacterial adherence. Rubber pieces that had been implanted in the biliary tracts of rats for 4 weeks were retrieved and the following approaches employed for further investigations: (1) adherence of [methyl-3H]thymidine-labeled Escherichia coli to implanted and unimplanted rubber pieces; (2) blocking the adherence of radiolabeled bacteria with anti-Fn antibodies; (3) detection of deposited Fn by 125I-labeled anti-Fn IgG; and (4) immunoblotting of the surface eluate from implanted rubber pieces. The results show that in the presence of serum, plasma, or bile, the number of E. coli cells adherent to implanted rubber pieces was 10 times higher than that adherent to the unimplanted pieces (P < 0.001) and that the adherence was reduced by pretreatment of implanted pieces with anti-Fn antibodies. Furthermore, the implanted pieces appeared to have a high affinity for 125I-labeled rabbit anti-Fn IgG rather than the 125I-IgG without anti-Fn fraction. Fn was also found in the surface eluate of implanted pieces by immunoblotting of the eluate. The results in the present study suggest that Fn may be involved in implant-associated infections in the biliary tract.

Animals↗
PubMed1995

On the prevention of accidents and injuries. A comparative analysis of conceptual frameworks.

The meaning of prevention has changed as new applications of the concept have appeared. Ideas presented in eleven different conceptual frameworks are compared. Identification of the frameworks took place through searches in databases and relevant literature. Five are general by nature, while six relate to injuries and accidents. All are supported by just a few parameters, the time dimension being the most prominent. Compatibility was established on three additional dimensions: level (individual, organizational or societal); direction ("bottom-up" or "top-down"); and in relation to the trichotomy "host-agent-environment". An attempt to synthesize all these dimensions into one general model of accident and injury prevention is presented.

Accident Prevention↗
PubMed1995

Reticuloendothelial system function in acute liver injury induced by D-galactosamine.

AIMS/METHODS: Reticuloendothelial system function, as assessed by clearance of radiolabelled bacteria, was evaluated in acute liver injury induced by D-galactosamine in rats, and compared with that after 70% liver resection model. RESULTS: Reticuloendothelial system function was significantly impaired in both instances, but the extent and the pattern of reticuloendothelial system impairment differed in the two models. While the elimination rate of the radiolabelled bacteria (k-value) decreased in both the liver resection and D-galactosamine groups (19% and 52%, respectively), the corrected phagocytic index (alpha) increased in 70% liver resection (247%), indicatine increased activity among the remaining reticuloendothelial system cells of the liver. Estimation of subserosal organ blood flow showed decreased flow to the cecum and distal small intestine (correction of intesting) in both groups, whereas it was significantly increased (477%) in the remaining parts of the liver in the liver resection group. CONCLUSIONS: These findings show that reticuloendothelial system activity is deranged in both these groups, which may explain the increased occurrence of bacterial complications observed in corresponding clinical conditions.

Animals↗
PubMed1995

Effective treatment with interferon-alpha in chronic recurrent multifocal osteomyelitis.

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare disease of unknown etiology characterized by multiple osteomyelitic changes in the predominantly metaphysial regions of long bones. It was first described by Giedon et al. in 1972. Cultures for all known microorganisms are negative. Pain is the most common symptom, and sometimes soft tissue swelling is present. Patients are usually treated with nonsteroidal antiinflammatory drugs (NSAIDs) or corticosteroids and respond, at least partly, to these treatments. CRMO is most commonly seen in children and is in the majority of cases self-limiting but has a protracted course of several years. Some patients have a more prolonged disease period, as in the patient reported here. Treatment with corticosteroids in children has the risk of causing growth retardation as a potential adverse effect, and alternative treatments are of great interest. In the actual paper, a successful treatment with interferon-alpha 2b in a 34-year-old man with CRMO is presented.

Adult↗
PubMed1995

Clusters of acute appendicitis: further evidence for an infectious aetiology.

BACKGROUND: The aetiology of appendicitis, the commonest cause of acute abdomen, is unknown. Infection has been proposed but the evidence has been unconvincing. The purpose of the present study was to investigate if temporo-spatial clustering and outbreaks, characteristics of infectious diseases, could be found in appendicitis cases in a defined Swedish population. METHODS: Temporo-spatial clustering among 1155 cases from three districts of Jönköping County in 1984-1990 was identified by Knox space-time cluster analysis. Outbreaks were identified by retrospective study of temporal variations in 3590 consecutive cases of acute appendicitis from the city of Jönköping in 1969-1990. RESULTS: Space-time clustering was found among patients with operations less than 60 days apart (observed/expected [O/E]-ratio 1.46, P = 0.016). Subset analysis revealed clustering to be commonest among patients from the same households (O/E-ratio 6.52, P = 0.012), among patients younger than 15 years (O/E-ratio 3.61, P = 0.004) and among females (O/E-ratio 2.28, P = 0.004). Three outbreaks with a significantly increased number of cases were observed during the 22-year study period (O/E-ratio 1.6-2.2, P = 0.001-0.049). CONCLUSIONS: The finding of temporo-spatial interaction and outbreaks among appendicitis cases supports the concept that appendicitis may be caused by infectious agents.

Acute Disease↗
PubMed1995

Epidemiology and mortality in 220 patients with polymyalgia rheumatica.

Between 1985 and 1987 a total of 521 people underwent temporal artery biopsy with no histological evidence of arteritis in Göteborg, Sweden. Two-hundred-and-twenty people were diagnosed as having polymyalgia rheumatica (PMR). Among the patients without PMR 30% had rheumatic, 17% malignant and 14% infectious disorders. The annual incidence of PMR with negative biopsy was 17/100,000 and for the population over 50 yr it was 50/100,000. We found an increased mortality in vascular diseases among men with PMR in the first 2 yr after diagnosis with 13 observed deaths compared to the expected six (P < 0.01). There was also a tendency toward an increased mortality among the women with 16 observed deaths compared to the expected 11 (not statistically significant). The mortality in malignant diseases was not increased.

Aged↗
PubMed1995

Epidemiologic aspects of infective endocarditis in an urban population. A 5-year prospective study.

A prospective study of the epidemiology of infective endocarditis (IE) in a well-defined urban population of 428,000 inhabitants during a 5-year period was carried out. All patients were treated in the same institution, and history, diagnostic procedures, and treatment were standardized. Of 233 consecutive suspected episodes of IE, 127 fulfilled the modified von Reyn criteria. After patients not living in the defined area were excluded, 99 episodes in 90 patients were analyzed in the epidemiologic part of the study. Of these, 33 episodes were definite endocarditis, verified by surgery or autopsy; 35 probable; and 31 possible endocarditis episodes. Another 34 episodes were found retrospectively and are included in the incidence calculation. The crude incidence was calculated to be 6.2/100,000 inhabitants per year, which is high compared to earlier studies. Adjusted to the population of Sweden, the incidence was 5.9/100,000 inhabitants per year. The annual incidence was higher for women, 6.6/100,000, than for men, 5.8/100,000. In the oldest age-group (80-89 years) the annual incidence was 22/100,000 in the prospective study and 30/100,000 if retrospective cases were included. Contrary to almost all other studies, we did not find a male predominance among our cases. Only 7% of patients were intravenous drug abusers, and 15% had a prosthetic valve. The most common bacteria were methicillin-susceptible Staphylococcus aureus (31%) and alpha-streptococci (28%); 12% of episodes were culture negative. The mortality from IE in the population was 1.4/100,000 inhabitants per year. A higher-than-expected incidence of IE was found, especially among older patients and women.

Adolescent↗