The aim of this study was to investigate the interactions between the cyanobacteria (Microcystis aeruginosa) and the potential grazer (Ochromonas sp.) with regard to colony formation. Two kinds of ...treatments were carried out: (i) In the dialyse experiment Microcystis aeruginosa and Ochromonas sp. were physically separated by a dialyse tubing. (ii) In the contact experiment interactions between Microcystis aeruginosa, heterotrophic bacteria and Ochromonas sp. in different concentrations were investigated. In one treatment where the predator Ochromonas sp. came in direct contact with Microcystis, aggregates were formed. In the contact experiment, there were some interactions between the predator Ochromonas sp. and the two groups of prey, Microcystis aeruginosa and heterotrophic bacteria. When exposed to a low initial Ochromonas sp. concentration, Microcystis aeruginosa decreased and then remained stable in concentration. Ochromonas sp. switched to feed on heterotrophic bacteria and increased. At a high initial Ochromonas sp. concentration Microcystis was grazed down.PUBLICATION ABSTRACT
The combustion and melt dripping of poly(ethylene-
co-butyl acrylate) (EBA), EBA blended with polypropylene (EBA–PP) and poly(ethylene-
co-methacrylic acid) (EMAA), each blended with calcium ...carbonate and polydimethylsiloxane, were studied. In situ measurement of the temperature gradient in the cone calorimeter were combined with infrared spectroscopy measurements on specimens withdrawn and quenched at different times of the experiment. The reactions that govern the degradation at the high heating rates met in the combustion could be determined and the gap to analytical techniques such as thermogravimetry bridged. The interplay of mechanical char integrity and heat feedback by the flame determined how much time the specimen dwells in temperature range of 300–420
°C where char expansion due to calcium salt formation is effective and thereby affects the heat release rate strongly. Vertical cone calorimeter and vertical flame testing were used to assess melt dripping and char stability under flaming combustion. Plate–plate rheological measurements proofed to be of limited use to compare the effect of different degradation atmospheres on the melt viscosity. The EMAA formulation had the most effective intumescent process with a low heat release rate and good char stability even in vertical configuration. Electron-beam irradiated EMAA specimens with different levels of cross-links were tested in the cone calorimeter in order to understand the role of cross-links for the intumescent process.
Summary
Objectives Primary adrenocortical insufficiency is mostly caused by an autoimmune destruction of the adrenal cortex. The disease may appear isolated or as a part of an autoimmune ...polyendocrine syndrome (APS). APS1 is a rare hereditary disorder with a broad spectrum of clinical manifestations. In APS2, primary adrenocortical insufficiency is often combined with autoimmune thyroid disease and/or type 1 diabetes. We analysed mortality and cancer incidence in primary adrenocortical insufficiency patients during 40 years. Data were compared with the general Swedish population.
Design and patients A population based cohort study including all patients with autoimmune primary adrenocortical insufficiency (3299) admitted to Swedish hospitals 1964–2004.
Measurements Mortality risk was calculated as the standardized mortality ratio (SMR) and cancer incidence as the standardized incidence ratio (SIR).
Results A more than 2‐fold increased mortality risk was observed in both women (SMR 2·9, 95% CI 2·7–3·0) and men (SMR 2·5, 95% CI 2·3–2·7). Highest risks were observed in patients diagnosed in childhood. SMR was higher in APS1 patients (SMR 4·6, 95% CI 3·5–6·0) compared with patients with APS2 (SMR 2·1, 95% CI 1·9–2·4). Cancer incidence was increased (SIR 1·3, 95% CI 1·2–1·5). When tumours observed during the first year of follow‐up were excluded, only the cancer risk among APS1 patients remained increased. Cause‐specific cancer incidence analysis revealed significantly higher incidences of oral cancer, nonmelanoma skin cancer, and male genital system cancer among patients. Breast cancer incidence was lower than in the general population.
Conclusions Our study shows a reduced life expectancy and altered cancer incidence pattern in patients with autoimmune primary adrenocortical insufficiency.
Since its introduction in the late 1960s, the technology of colonoscopy has developed rapidly and the competence of endoscopists has increased. Nevertheless, it is not always possible to perform a ...complete colonoscopy. The aim of this study was to assess, in a population-based setting, the endoscopist-related factors influencing the completion rate, taking into account patient characteristics and changes in the technology over time.
All colonoscopy records between 1979 and 1995 in one Swedish county (population 258,000) were retrieved. Information was obtained about patient demographics, date of examination, endoscopist, indications, presence of diverticulosis, type of colonoscopy, findings, level of completion, complications, and reasons for incomplete colonoscopy. Completion rates were examined by univariate and multivariate analyses.
Of 5,494 colonoscopies, 4,153 (75%) were complete, and 78% were diagnostic and 22% therapeutic. In 70 %, findings were pathological, and 30 % were normal. The overall 30-day endoscopist-related complication rate was 0.3 %. Over time, the proportion of colonoscopies performed by endoscopists with greater experience increased and so did the completion rates. Completion rates were influenced by endoscopist's experience and to some extent by the intensity (the number of colonoscopies performed by the endoscopist during the previous 90 days). There was a large interendoscopist variation, at each level of experience, in the ability to perform a complete colonoscopy, implying substantial differences between individual learning curves.
The completion rate has increased over time, the major reason being greater competence of endoscopists. The finding of large interendoscopist variation, at each level of experience, in the ability to perform a complete colonoscopy supports the monitoring of endoscopists to maintain and improve performance.
Aims
In patients with sinus node disease, dual-chamber pacing (DDD) possibly results in adverse effects on the ventricular function. We have compared the incidence of cardiovascular morbidity and ...mortality in patients with sinus node disease and with atrioventricular (AV) synchronous pacemakers, DDD vs. atrial pacing (AAI).
Methods and results
A nation-wide population-based cohort of 8777 patients with AAI- or DDD-mode pacemakers was followed during 12 years. The cohort was linked to national healthcare and census registers. Patients with DDD pacing and without any pre-implant admission for atrial fibrillation or flutter had an increased risk of post-implant fibrillation or flutter, in relation to corresponding AAA patients hazard ratio (HR) = 1.30; 95% confidence interval (CI) 1.10-1.52. A slight increase in the risk of any cardiovascular disease (HR = 1.07; CI, 1.00-1.15), and all-cause mortality (HR = 1.12; CI, 1.00-1.25), was seen among DDD patients, in relation to AAI patients, but there was no significant difference in the risk of ischaemic or unspecified stroke (HR = 1.14; CI, 0.94-1.37). Among DDD patients, the all-cause mortality did not differ from the general population standardized mortality ratio (SMR) = 1.04; CI, 0.98-1.11. Patients with AAI, however, had a decreased all-cause mortality risk (SMR = 0.89; CI, 0.82-0.97).
Conclusion
Our results support AAI as the preferred mode of pacing in patients with sinus node disease, and a normal AV node function.
In this study, we evaluated growth responses of the green alga Scenedesmus and the cyanobacterium Synechococcus supplied with inorganic nitrogen in different ways. A competitive situation in which ...nitrogen was limiting was created in mixed cultures as well as in cultures growing in the same vessel but separated by a permeable dialysis membrane. Supplying inorganic nitrogen in small pulses at a high frequency favoured the cyanobacterium Synechococcus, whereas batch additions favoured the green alga Scenedesmus. When using a large-pulse/low-frequency supply mode, the yield of the green alga was higher when ammonium was added as nitrogen source compared to when nitrate was added. By contrast, the yield of the cyanobacterium was higher in the nitrate regime. However, uptake experiments using unialgal cultures showed that both organisms depleted the medium of ammonium more rapidly than they depleted the medium of nitrate; i.e. the higher yield of the cyanobacterium in the nitrate regime than in the ammonium regime can be attributed to the effects of competition with the green alga. Since nitrate assimilation involves the consumption of reductive power, we suggest that the outcome of competition was governed by the fact that green alga was light limited and therefore better able to compete for ammonium than for nitrate. The results from the laboratory studies are discussed in relation to results from an enclosure experiment performed in Lake Erken, Sweden. In that field experiment, in which additions of both phosphate and ammonium were applied every second day to 350-l enclosures, the green algal biomass increased exponentially during an incubation period of 22 days.PUBLICATION ABSTRACT
BACKGROUND Several case reports, but only a few studies, have examined the coexistence of coeliac disease and primary biliary cirrhosis. AIM To estimate the risk of primary biliary cirrhosis in two ...national cohorts of patients with coeliac disease in Denmark and Sweden. METHODS Through record linkage all Danish patients hospitalised with coeliac disease were followed for possible occurrence of primary biliary cirrhosis from 1 January 1977 until 31 December 1992. All patients hospitalised with coeliac disease in Sweden from 1987 to 1996 were also followed in a separate analysis. RESULTS A total of 896 patients with coeliac disease were identified in Denmark with a median follow up period of 9.1 years for a total of 8040 person-years at risk. Two cases of primary biliary cirrhosis were observed where 0.07 were expected, giving a standardised incidence ratio of 27.6 (95% confidence interval 2.9 to 133.5). A total of 7735 patients with coeliac disease were identified in Sweden with a median follow up period of 5.1 years for a total of 39 284 person-years at risk. Twenty two people with primary biliary cirrhosis were identified compared with 0.88 expected, giving a standardised incidence ratio of 25.1 (95% confidence interval 15.7 to 37.9). CONCLUSION Patients with coeliac disease are at increased risk of having primary biliary cirrhosis.
Thirty‐three cases of postirradiation sarcoma (PIS) from the files of the Finnish Cancer Registry were analyzed. The most frequent first primary tumors were cancers of the breast (seven cases) and ...female reproductive organs (13 cases). Five patients had a childhood cancer. The median total radiation dose at the site of the PIS was 3600 cGy (1600 cGy to 11200 cGy). The median interval from start of radiation therapy to detection of PIS was 13.2 years (3.4 to 22.8 years). The PIS was of soft tissue origin in 25 of 33 cases. The most frequent histologic types were osteosarcoma (ten cases, including four extraskeletal tumors), malignant fibrous histiocytoma (ten cases), and fibrosarcoma (six cases). The overall crude 5‐year survival rate was 29% (calculated from the start of treatment for PIS), and for patients initially treated with either radical surgery or combined marginal surgery and postoperative irradiation it was 67%. The authors conclude that there is a chance for cure for radically treated patients with postirradiation sarcoma that emphasizes the importance of regular long‐term follow‐up of cancer patients.
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