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| 2. |
- Nilsson, Cathrine, 1978-, et al.
(författare)
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Cytosolic acidification and lysosomal alkalinization during TNF-α induced apoptosis in U937 cells
- 2006
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Ingår i: Apoptosis (London). - : Springer Netherlands. - 1360-8185 .- 1573-675X. ; 11:7, s. 1149-1159
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Tidskriftsartikel (refereegranskat)abstract
- Apoptosis is often associated with acidification of the cytosol and since loss of lysosomal proton gradient and release of lysosomal content are early events during apoptosis, we investigated if the lysosomal compartment could contribute to cytosolic acidification. After exposure of U937 cells to tumor necrosis factor-α, three populations; healthy, pre-apoptotic, and apoptotic cells, were identified by flow cytometry. These populations were investigated regarding intra-cellular pH and apoptosis-associated events. There was a drop in cytosolic pH from 7.2 ± 0.1 in healthy cells to 6.8 ± 0.1 in pre-apoptotic, caspase-negative cells. In apoptotic, caspase-positive cells, the pH was further decreased to 5.7 ± 0.04. The cytosolic acidification was not affected by addition of specific inhibitors towards caspases or the mitochondrial F0F1-ATPase. In parallel to the cytosolic acidification, a rise in lysosomal pH from 4.3 ± 0.3, in the healthy population, to 4.8 ± 0.3 and 5.5 ± 0.3 in the pre-apoptotic- and apoptotic populations, respectively, was detected. In addition, lysosomal membrane permeability increased as detected as release of cathepsin D from lysosomes to the cytosol in pre-apoptotic and apoptotic cells. We, thus, suggest that lysosomal proton release is the cause of the cytosolic acidification of U937 cells exposed to TNF-α.
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| 3. |
- Davies, Simon, et al.
(författare)
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The effects of low-sodium peritoneal dialysis fluids on blood pressure, thirst and volume status
- 2009
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Ingår i: Nephrology Dialysis Transplantation. - : Oxford University Press (OUP). - 1460-2385 .- 0931-0509. ; 24:5, s. 1609-1617
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Tidskriftsartikel (refereegranskat)abstract
- Background. Poor ultrafiltration is associated with worse outcomes in peritoneal dialysis (PD) patients. This might in part reflect problems associated with salt and water excess. Increasing the diffusive component of peritoneal sodium removal using low-sodium PD fluids might have beneficial effects on blood pressure (BP), thirst and fluid status that could translate into clinical benefits. Methods. Using a multicentre, prospective, baseline controlled (1 month), non-randomized intervention (2 months) design, two novel solutions designed from predictions using the three-pore model were investigated. In group A ([Na+] = 115 mmol/l), the glucose (G) was increased to 2.0% to compensate for reduced osmolality whereas in group B ([Na+] = 102 mmol/l), it was unchanged (2.5%). Both solutions were substituted for one 3- to 5-h exchange per day and no change was made to the rest of the dialysis regime. Results. Ten patients in group A and 15 in group B completed the study. Both solutions resulted in significant increases (30-50 mmol/dwell) in diffusive sodium removal during the test exchanges, P < 0.001. Ultrafiltration was maintained in group A but reduced in group B. Ambulatory nocturnal mean BP fell in group A [93.1 +/- 10.6 mmHg (+/- SD) versus 85.1 +/- 10.2 mmHg, P < 0.05], but was stable in group B (95.4 +/- 9.4 versus 95.1.1 +/- 10.7 mmHg, NS). Thirst reduced independent of appetite and mood in both groups by 2 months, more markedly in group A. Indices of fluid status, including TBW by bioimpedance and D dilution also improved in group A, P < 0.05, whereas weight increased in group B. Conclusions. Increasing the diffusive component of sodium removal whilst maintaining ultrafiltration is associated with improvements in BP, thirst and fluid status. The lack of effect seen with uncompensated low-sodium dialysate suggests that these benefits cannot be achieved by manipulation of dialysate sodium removal alone. These observations provide valuable information of the design of future randomized studies to establish the clinical role for low-sodium dialysis fluids.
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| 6. |
- Johansson, Ann-Cathrine, 1950
(författare)
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Nutritional status in peritoneal dialysis. Studies in body composition, lipoprotein metabolism and peritoneal function
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Nutritional status in peritoneal dialysis. Studies in bodycomposition, lipoprotein metabolism and peritoneal function. Department of Nephrology,Institute of Internal Medicine, Sahlgrenska University Hospital, SE-413 45 Gothenburg,Sweden.The aim of the study was to investigate the nutritional and metabolic consequences and theperitoneal transport conditions of long term peritoneal dialysis. A further purpose was toevaluate methods currently used for measuring delivered dialysis dose and nutritionalstatus.The study was a clinical observational study including almost all patients commencingperitoneal dialysis at the Sahlgrenska University Hospital during the 1990s.Nutritional status was assessed by body composition analyses including total body potassiumas a measure of body cell mass. Total body water was measured by tritium dilution and bodyfat was calculated according to a four-compartment model. At start of dialysis, body cell massand body fat were slightly reduced compared to normal values. During follow-up, there was afurther decline of body cell mass, while energy stores were replenished. Total body waterremained unchanged, which implies an increase in extracellular water.A cross-sectional detailed analysis of the lipoprotein profile showed that the patients onperitoneal dialysis had increased plasma concentrations of cholesterol and triglycerides andincreased levels of ApoB-containing lipoproteins compared to normal subjects. ApoA-I- andApoA-II-containing lipoproteins were reduced and inversely correlated to time on dialysis.Peritoneal function was assessed by the Peritoneal Dialysis Capacity test, based on the three-poremodel of capillary transport. Patients with diabetic nephropathy and nondiabeticsystemic disease had increased peritoneal diffusion capacity already at start of dialysis.Peritoneal protein losses were increased in patients with more severe co-morbidity. Peritonealfunction remained essentially stable during medium long-term follow-up.A comparison was made between estimations of lean body mass from creatinine generationrate and measurements of total body potassium, respectively. A low degree of agreementbetween the two methods was found. Furthermore, the coefficient of variation for repeatedmeasurements of creatinine generation rate was high.The clearance for urea (Kt/Vurea) is normalised to total body water, which is the distributionvolume for urea (V). Prediction equations, based on anthropometric measurements, arefrequently used to estimate V. Measurements of total body water volumes by tritium dilutionwere compared to calculations of total body water according to the Watson formulas.Although mean values of the two methods were similar, the prediction equationsoverestimated the body water in obese patients, and vice versa in lean or overhydratedpatients.These studies have provided further insight in the nutritional status and lipoprotein profile inpatients treated with peritoneal dialysis. Moreover, the limitations of conventional methodsfor nutritional assessment in dialysis patients have been recognized.
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| 7. |
- Johansson, Ann-Cathrine, et al.
(författare)
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Physiological properties of the peritoneum in an adult peritoneal dialysis population over a three-year period
- 2006
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Ingår i: Peritoneal Dialysis International. - 1718-4304. ; 26:4, s. 482-9
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To describe the physiological properties of the peritoneal membrane in adult patients treated with peritoneal dialysis (PD) and to analyze the effects of patient characteristics and time. Design: Observational study. Setting: Department of Nephrology at the Sahlgrenska University Hospital. Method: Peritoneal function was analyzed by the Personal Dialysis Capacity (PDC) test, based on the three-pore theory of capillary transport. The functional PDC variables are absorption, large-pore flow, and the area parameter (A(0)/Delta x), which determines the diffusion of small solutes. The ultrafiltration (UF) coefficient is determined mainly by A(0)/Delta x. Patients: All patients (n = 280) who had at least one PDC test done between September 1990 and August 1999. Results: In 249 patients examined soon after start of PD, area was 19000 (SD 7100) cm(2)/cm/1.73 m(2), large-pore flow 0.112 (SD 0.052) mL/min/1.73 m(2), and the UF coefficient 0.071 (SD 0.032) mL/minute/mmHg/1.73 m(2). Absorption was 1.54 (SD +2.64, -0.97) mL/min/1.73 m(2). Large-pore flow was greater in patients with severe comorbidity than in patients with fewer comorbid conditions. Elderly patients had a lower UF coefficient than did younger patients (p < 0.05). Repeated PDC tests were performed in 208 patients during a mean observation time of 18.4 months. There was a slight increase in the slope of the area-versus-time curve of 54 cm(2)/cm/1.73 m(2) per month (approximately 10% after 3 years, p < 0.01); all other parameters remained constant. Conclusion: Patient characteristics have an impact on peritoneal performance already at the start of dialysis. Peritoneal function can remain essentially stable during medium long-term PD.
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| 8. |
- Johansson, Ann-Charlotte, et al.
(författare)
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Regulation of apoptosis-associated lysosomal membrane permeabilization
- 2010
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Ingår i: APOPTOSIS. - : Springer Science Business Media. - 1360-8185 .- 1573-675X. ; 15:5, s. 527-540
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Tidskriftsartikel (refereegranskat)abstract
- Lysosomal membrane permeabilization (LMP) occurs in response to a large variety of cell death stimuli causing release of cathepsins from the lysosomal lumen into the cytosol where they participate in apoptosis signaling. In some settings, apoptosis induction is dependent on an early release of cathepsins, while under other circumstances LMP occurs late in the cell death process and contributes to amplification of the death signal. The mechanism underlying LMP is still incompletely understood; however, a growing body of evidence suggests that LMP may be governed by several distinct mechanisms that are likely engaged in a death stimulus- and cell-type-dependent fashion. In this review, factors contributing to permeabilization of the lysosomal membrane including reactive oxygen species, lysosomal membrane lipid composition, proteases, p53, and Bcl-2 family proteins, are described. Potential mechanisms to safeguard lysosomal integrity and confer resistance to lysosome-dependent cell death are also discussed.
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| 9. |
- Johansson, Glenn, et al.
(författare)
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IMPLEMENTATION OF R&D MANAGEMENT MODELS IN GLOBAL ORGANISATIONS
- 2015
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Ingår i: DS 80-3 PROCEEDINGS OF THE 20TH INTERNATIONAL CONFERENCE ON ENGINEERING DESIGN (ICED 15) VOL 3. - 9781904670667
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Konferensbidrag (refereegranskat)abstract
- This paper addresses implementation of R&D management models in global product development organisations. The study rests upon empirical material originating from five industrial companies that was collected via workshops and interviews. A number of enablers for and barriers to implementation of R&D management models have been identified. The study adds to the current theory on how companies with global organisations can ensure that the R&D management model is implemented throughout the entire organisation. In addition, the practical value refers to that the identified enablers and barriers support companies in their strive towards better adherence to the R&D management models in product development projects.
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| 11. |
- Pihl, Maria, et al.
(författare)
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Bacteria on catheters in patients undergoing peritoneal dialysis
- 2013
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Ingår i: Peritoneal Dialysis International. - : SAGE Publications. - 1718-4304 .- 0896-8608. ; 33:1, s. 51-59
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Tidskriftsartikel (refereegranskat)abstract
- Background: Peritonitis is the leading cause of morbidity for peritoneal dialysis (PD) patients, and microbial biofilms have previously been identified on catheters from infected patients. However, few studies of catheters from patients without clinical signs of infection have been undertaken. The aim of the present study was to investigate the extent to which bacteria are present on catheters from PD patients with no symptoms of infection. Methods: Microbiologic culturing under aerobic and anaerobic conditions and confocal laser scanning microscopy were used to determine the distribution of bacteria on PD catheters from 15 patients without clinical signs of infection and on catheters from 2 infected patients. The 16S rRNA gene sequencing technique was used to identify cultured bacteria.. Results: Bacteria were detected on 12 of the 15 catheters from patients without signs of infection and on the 2 catheters from infected patients. Single-species and mixed-microbial communities containing up to 5 species were present on both the inside and the outside along the whole length of the colonized catheters. The bacterial species most commonly found were the skin commensals Staphylococcus epidermidis and Propionibacterium acnes, followed by S. warneri and S. lugdunensis. The strains of these micro-organisms, particularly those of S. epidermidis, varied in phenotype with respect to their tolerance of the major classes of antibiotics. Conclusions: Bacteria were common on catheters from patients without symptoms of infection. Up to 4 different bacterial species were found in close association and may represent a risk factor for the future development of peritonitis in patients hosting such micro-organisms. Perit Dial Int 2013; 33(1):51-59 www.PDIConnect.com epub ahead of print: 01 Aug 2012 doi:10.3747/pdi.2011.00320
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| 14. |
- Wang, Yanmin, et al.
(författare)
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Purification of fine powders by a superconducting HGMS with vibration assistance
- 2000
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Ingår i: Magnetic and Electrical Separation. - : Hindawi Limited. - 1055-6915 .- 1029-0303 .- 1477-2876. ; 10:3, s. 161-178
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a superconducting high gradient magnetic separator (HGMS) with a matrix vibration system in dry mode was utilized to purify fine calcite and quartz powders smaller than 38 μm. The effects of the operating parameters (particle size, magnetic field/average air velocity (B0/V0), the amplitude of vibration as well as the aperture size of the expanded metal matrix) have been presented. The mechanically-based matrix vibration with the air blowing was recognized to be effective for dry purification of fine powdered materials at high magnetic fields. The function of the matrix vibration has been discussed. In addition, the results have been empirically correlated with the operating parameters used for the purification in the separator.
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