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Biomedical subjects

B Isaksson

Publications and source records attributed to B Isaksson.

At least 37 records · Page 2Linked to original sources

Control of an outbreak of a highly beta-lactam-resistant Enterobacter cloacae strain in a neonatal special care unit.

Two successive outbreaks of colonization and infection with Enterobacter cloacae resistant to third generation cephalosporins (cephalosporin-resistant E. cloacae, CREC) and involving 15 infants occurred within 12 months in a neonatal special care unit. Isolates of clinical significance were obtained from four infants (urine 2 cases, blood, pleural drainage). According to epidemiological typing using computerized biochemical fingerprinting and pulsed-field gel electrophoresis (PFGE) the same CREC strain was found in both outbreaks. The origin of the strain and its reservoir between the two outbreaks remained unknown. Emphasizing strict barrier nursing of the infants had little or no impact on the presence and transmission of the strain in the unit. In contrast, replacing ampicillin plus cefotaxime as standard empiric therapy with penicillin G plus netilmicin plus consequent cohorting of newborns and staff promptly halted both the outbreaks. During a 5-y follow-up after the last episode, the choice of antibiotics for empirical treatment has varied, and no further outbreaks of CREC have been seen, with the exception of two sporadic cases.

Ampicillin↗

Skeletal muscle insulin resistance after trauma: insulin signaling and glucose transport.

Surgical trauma induces peripheral insulin resistance; however, the cellular mechanism has not been fully elucidated. We examined the effects of surgical trauma on insulin receptor signaling and glucose transport in skeletal muscle, a tissue that plays a predominant role in maintaining glucose homeostasis. Surgical trauma was induced by intestinal resection in the rat. Receptor phosphorylation was not altered with surgical trauma. Phosphotyrosine-associated phosphatidylinositol (PI) 3-kinase association was increased by 60 and 82% compared with fasted and fed controls, respectively (P < 0. 05). Similar results were observed for insulin receptor substrate-1-associated PI 3-kinase activity. Insulin-stimulated protein kinase B (Akt kinase) phosphorylation was increased by 2.2-fold after surgical trauma (P < 0.05). The hyperphosphorylation of Akt is likely to reflect amplification of PI 3-kinase after insulin stimulation. Submaximal rates of insulin-stimulated 3-O-methylglucose transport were reduced in trauma vs. fasted rats by 51 and 38% for 100 and 200 microU/ml of insulin, respectively (P < 0.05). In conclusion, insulin resistance in skeletal muscle after surgical trauma is associated with reduced glucose transport but not with impaired insulin signaling to PI 3-kinase or its downstream target, Akt. The surgical trauma model presented in this report provides a useful tool to further elucidate the molecular mechanism(s) underlying the development of insulin resistance after surgical trauma.

Animals↗

Long-term effects of repeated injection sclerotherapy on esophageal motility and mucosa.

BACKGROUND: Endoscopic sclerotherapy (ST), widely used as treatment of bleeding esophageal varices, might cause motility disturbances of the esophagus as well as mucosal damage. We performed this study to evaluate the long-term effects of repeated sclerotherapy on esophageal motility and mucosa. METHODS: Ten patients with liver cirrhosis and bleeding esophageal varices treated with repeated ST were evaluated after the last ST, median 52 months, by esophageal manometry and gastroscopy where forceps biopsies were taken. RESULTS: We found a significant difference in the distal esophageal sphincter intraabdominal length. The distal esophageal sphincter pressure was somewhat lower in the ST group although the difference did not reach statistical significance. There was infiltration of neutrophil leukocytes in biopsies from four patients and normal findings in the rest. CONCLUSIONS: Long-term follow-up evaluation showed statistically longer distal esophageal intraabdominal length in the ST group. No mucosal alterations were found at the histopathological investigation.

Aged↗

A descriptive study of blood exposure incidents among healthcare workers in a university hospital in Sweden.

In an attempt to document blood exposure incidents and compliance with recommended serological investigations, universal precautions and incident reporting routines, data was collected from occupational injury reports during a two-year period. In addition, a sample of healthcare workers (HCWs) answered a questionnaire about blood tests and work routines. In a third part of the study some HCWs were asked about the type and actual frequency of incidents, together with the number of reported incidents during the two-year study period. Of a total of 473 reported occupational blood exposures, the majority came from nurses and the minority from physicians. Most reported incidents occurred on hospital wards. The most common incidents were needlestick injuries, and 35% occurred when the needle was recapped. Medical laboratory technicians (MLT) reported significantly more mucocutaneous incidents than other professionals (P < 0.01). In 10% of the incidents, the patient had a known blood-borne infection. Serological investigations post-exposure varied among professional groups, and 35% were not tested. No seroconversion was shown in the HCWs tested. In the third part of the study, respondents recalled 1180 incidents, although only 9% of these had been reported. The majority occurred in operating theatres, and in connection with anaesthesia. There was a significant difference (P < 0.001) between the different professional groups with regard to the frequency of incident reporting. Physicians reported only 3% and MLTs 36% of the incidents. Eighty-one percent believed that the accident could have been avoided. Despite knowledge of universal precautions, professionals continue to behave in a risky manner, which can result in blood exposure incidents.

Adolescent↗

Mesocaval interposition shunting in the treatment of bleeding oesophageal varices.

OBJECTIVE: To assess the longterm results of mesocaval interposition shunt in the treatment of bleeding oesophageal varices. DESIGN: Retrospective study. SETTING: University hospital, Sweden. SUBJECTS: 60 patients with bleeding oesophageal varices in all Child's classes. 20 of whom were operated on as emergencies, and 40 as elective cases. INTERVENTIONS: A 14 mm polytetrafluoroethylene graft was used as an interposition shunt between the superior mesenteric vein and the vena cava. MAIN OUTCOME MEASURES: Rebleeding rate, portal blood flow, hepatic encephalopathy, morbidity, mortality, and survival. RESULTS: Rebleeding was rare and occurred mainly during the first 4 months after operation, (n = 5) in 10% of the patients, and at the 24 month follow-up, (n = 4) in 11% of the patients. Portal flow was measured preoperatively in 33 patients and in 22 (67%) it was hepatopetal. During follow-up it was reversed and after 24 months no patient had hepatopetal flow. Hepatic encephalopathy was present in 18 patients (20%) during follow-up. Shunts thrombosed in 9 patients (15%), 8 of which required reoperation. There was no operative mortality, but 4 patients (7%) died within 30 days of surgery. The main late cause of death (18/26) was liver failure. The 1 year survival was 80%, the 3 year survival 70% and the 5 year survival 60%. CONCLUSIONS: The mesocaval interposition shunt gives good longterm results and can be recommended both as an emergency and an elective procedure for patients with portal hypertension and bleeding oesophageal varices that are unresponsive to sclerotherapy.

Adolescent↗

International Federation of Clinical Chemistry. Laboratory assessment of protein-energy status.

Laboratory and non-laboratory methods for assessing protein-energy nutritional status are reviewed. These are classified into methods for assessing adequacy of recent nutritional intake, methods for assessing whole body status, and tests which assist in the interpretation of these assessments. Each measurement is critically discussed in terms of the rationale for its use, the method of analysis, reference values, technical interference and limitations of methods, the effects of nutritional status and of other factors on the results, its overall usefulness in nutritional assessment, and its value relative to other methods. Non-laboratory tests such as dietary assessment, indirect calorimetry, functional tests and the many methods available for assessment of body composition, including anthropometry, bioelectrical impedance and isotope and imaging techniques, are compared with the clinical chemistry tests in common use, such as nitrogen balance, plasma protein measurements and urinary markers of muscle metabolism. This review provides comprehensive and practical advice on the use and limitations of these tests in the assessment of protein-energy nutritional status of a group, or of an individual patient.

Calorimetry↗

Laboratory assessment of protein energy status.

Protein energy malnutrition (PEM) is widespread throughout the world in both community and hospital settings. Assessment of PEM in an individual consists of good dietary and clinical assessment, followed by laboratory measurements. Recent changes in body weight and simple anthropometric measurements are also useful. Laboratory measurements have the advantage in that they are independent of body size, they can be made precisely, and allow monitoring of progress. However, laboratory measurements must be interpreted with caution, especially in seriously ill patients in the hospital.

Energy Metabolism↗

Mesocaval shunt or repeated sclerotherapy: effects on rebleeding and encephalopathy--a randomized trial.

BACKGROUND: Sclerotherapy is usually effective in controlling acutely bleeding esophageal varices. It may not be as effective as shunt surgery for prevention of rebleeding; therefore we undertook a prospective study comparing interposition mesocaval shunt (MCS) and repeated sclerotherapy. METHODS: Forty-five patients (mean age, 52.6 +/- 9.8 years) with variceal bleeding were randomized after emergency endoscopic sclerotherapy either to repeat variceal obliteration followed by regular check endoscopy (n = 21) or to elective interposition mesocaval shunting by use of 14 mm polytetrafluoroethylene graft (n = 24). There was an equal distribution of Child's classes in the two groups. RESULTS: In the sclerotherapy group 12 patients had recurrent hemorrhages causing five deaths compared with the shunt group, in which four patients had postoperative bleeding but without associated death. No difference was noted in the incidence of encephalopathy despite the development of total shunting 1 year after MCS. The median hospital stay was similar; 34.5 days (MCS) and 33 days (sclerotherapy). The number of intensive care unit days was also similar in the two groups. No difference was noted in survival in patients with Child's A and Child's B disease in the treatment groups. In patients with Child's C cirrhosis there was a statistically significant longer survival in patients undergoing MCS compared with patients undergoing sclerotherapy. CONCLUSIONS: The results of the study show that the rate of rebleeding is significantly higher after sclerotherapy than after mesocaval shunting. In patients with Child's C cirrhosis MCS may be an alternative to sclerotherapy for the prevention of rebleeding from esophageal varices in patients not suitable for transplantation.

Adult↗

Postantibiotic effect of aminoglycosides on staphylococci.

The postantibiotic effects (PAEs) of amikacin, gentamicin, netilmicin and tobramycin on Staphylococcus aureus and S. epidermidis were determined in vitro by a bioluminescence assay of bacterial ATP. Five strains of S. aureus and two strains of S. epidermidis were exposed for 1 h to varying concentrations of these aminoglycosides. Following removal of the antibiotics by dilution, bacterial regrowth was monitored at hourly intervals. The duration of the PAE increased with increasing aminoglycoside concentration. The mean PAEs for the five S. aureus strains ranged from 5-10 h at clinically achievable aminoglycoside concentrations (16-32 mg/L of amikacin and 4-8 mg/L of gentamicin, netilmicin and tobramycin). The results for one of the strains of S. epidermidis were similar to those observed for the S. aureus strains, while the PAEs on the other less susceptible S. epidermidis strain were shorter (0.5-2.5 h). For comparison, two of the S. aureus strains were exposed for 1 and 2 h to a range of concentrations of dicloxacillin (0.25-32 mg/L); this agent induced a much shorter PAE (0-2.3 h). It may be important to take account of the PAE when designing dosing regimens.

Amikacin↗

Gunshot fatalities in Stockholm, Sweden with special reference to the use of illegal weapons.

During the years 1980-1992 the Swedish legislation regarding possession and use of firearms has remained fairly unchanged. Simultaneously the reported incidence of both stolen firearms and confiscation of illegally possessed handguns has increased significantly. In order to determine the impact of this trend on gunshot mortality, all victims of firearm fatalities subjected to medicolegal autopsy in the Stockholm area 1980-81 and 1990-91 were studied. The overall two-year rate increased from 50 to 65, homicides and suicides contributing seven new cases each; accidents and "not determined" comprising only 0 to 2 cases in each period. Suicides were four times as common as homicides in the former period; ca. three times as common in the latter. Thus, a 70% increase in homicidal shooting has occurred (from 10 to 17), and the fatal use of illegal firearms increased from 50% to 93%. As expected, there was a definite male dominance (96%) among perpetrators as well as among victims (85%). Concerning suicides, the rate in the latter period was 18% above that in the former; illegal guns were used in 30% in 1990-91 as compared to 20% 1980-81. The pattern of wounding in suicides was similar to that reported in earlier studies; confirming that entrance wounds in the back, extremities and lower abdomen are indicative of homicide. Thus, common sense knowledge of firearm fatalities are confirmed: More widespread access to illegal weapons conveys a higher rate of gunshot fatalities. The perpetrator is likely to be male. Suicidal shots are usually aimed at the head (mouth, temple, forehead) or precordium. Most gunshot suicides are committed by means of legally possessed firearms.

Adolescent↗

Anti-neutrophil cytoplasm antibodies, anti-GBM antibodies and anti-dsDNA antibodies in glomerulonephritis.

The diagnostic potential of assays detecting anti-neutrophil cytoplasm antibodies (ANCA), anti-GBM antibodies and anti-dsDNA antibodies was evaluated by examining sera from time of admission in a consecutive series of 455 patients with biopsy verified primary or secondary glomerulonephritis (GN). ANCA were classified into c- and p-ANCA by indirect immunofluorescence (IIF) and ELISAs using alfa-granule extract, proteinase-3, myeloperoxidase (MPO), elastase and lactoferrin. C-ANCA was virtually confined to 64 patients with systemic small vessel vasculitis, 66-74% being c-ANCA positive. P-ANCA against MPO, seen in 47 patients, segregated through many diagnostic categories of primary and secondary severe GN. ANCA against lactoferrin and elastase were rare. Anti-dsDNA positive patients constituted 57% of the 44 ANA-positive patients with systemic lupus erythematosus. It is concluded that the IIF and ELISAs for anti-proteinase-3, anti-MPO, anti-dsDNA and anti-GBM have an acceptable performance and are useful in the primary diagnostic work-up of patients suspected for secondary GN as the majority of such patients will be classified by these assays.

Antibodies, Antineutrophil Cytoplasmic↗

Reproducibility and validity of 7-day food records.

The reproducibility of the 7-day food record method, as used in The Glostrup Population Studies, has been tested by 40 adult volunteers, mainly hospital staff, recording their dietary intakes in two 7-day periods. To validate the calculated protein intake a 24-h urine specimen was collected from all participants in period II, but for various reasons urine specimens were only obtained from 31 in period I. There were significant differences in the intakes of energy, protein and some vitamins and minerals between the two periods, but the nutrient densities, except for vitamin A, were equal. The mean energy distributions in the diet showed no significant differences between the two periods. The weekly variance ratio (S2within/S2between) was between 0.25 and 0.80 for most nutrients. The only ratios above 1.0 were found for vitamin A, vitamin C, vitamin D, vitamin B12 and chromium, selenium and sodium. The weekly coefficients of variance (CV) were for most nutrients less than 30%. In period II the mean protein intake estimated from the urine samples was 74.7 (+/- 15.9 SD) g/day, whereas the protein intake calculated from the diet records was 70.6 (+/- 18.4) g/day. The average estimated protein intake for the 31 people who collected urine in period I was 72.1 (+/- 18.3) g/day, whereas the calculated intake was 78.0 (+/- 22.7) g/day. In neither period were the mean differences significant.

Adolescent↗

Synergistic post-antibiotic effect of amikacin and beta-lactam antibiotics on Enterococcus faecalis.

The in-vitro post-antibiotic effect (PAE) of amikacin alone and in combination with ceftazidime, ceftriaxone and piperacillin was studied for two strains of Enterococcus faecalis using a bioluminescent assay of bacterial ATP. The two strains of E. faecalis were resistant to amikacin, ceftazidime and ceftriaxone but sensitive to piperacillin. The bacterial cultures were incubated with the beta-lactam antibiotics for 1 h and concentrations of amikacin between 2-64 mg/l were then added. Thereafter, incubation continued with the combinations for one more hour. After dilution, regrowth was monitored by measuring bacterial ATP every hour. Increasing concentrations of amikacin (2-64 mg/l), ceftazidime (8-32 mg/l) and ceftriaxone (32-128 mg/l) resulted in little or no PAE (0-0.3 h) on these strains. PAEs of 0.5 to 1.6 h resulted from exposure to piperacillin (4-32 mg/l). In combination amikacin and piperacillin increased the PAE to 5.5 h. A synergistic PAE was also seen when the enterococci were exposed to amikacin combined with ceftazidime or ceftriaxone in concentrations close to the MICs of the latter antibiotics.

Amikacin↗

Synergic post-antibiotic effect of amikacin in combination with beta-lactam antibiotics on gram-negative bacteria.

The post-antibiotic effect (PAE) of amikacin alone and in combination with ceftazidime, ceftriaxone and piperacillin was studied for two strains each of Pseudomonas aeruginosa and Serratia marcescens using a bioluminescent assay of bacterial ATP. Two models were used for combining beta-lactam antibiotics and amikacin: in one model the cultures were incubated with 32 mg/L of ceftazidime, 128 mg/L of ceftriaxone or 32 mg/L of piperacillin for 1 h. Different concentrations of amikacin (0.5-64 mg/L) were then added. Incubation of the combinations continued for one more hour. The antibiotics were eliminated by dilution. In the second model tested, one strain of S. marcescens was simultaneously exposed to amikacin and a beta-lactam antibiotic for 2 h. The PAEs produced by the drugs in combination were longer than the sum of the individual effects of the drugs when they were used alone. Results were equally good with both models. A synergic PAE was also found with amikacin concentrations close to the MIC in combination with low concentrations of ceftazidime, ceftriaxone and piperacillin.

Amikacin↗