Pre-dilution haemofiltration--the Sardinian multicentre studies: present and future. The Sardinian Collaborative Study Group on Haemofiltration On-Line.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
M Boström
Publications and source records attributed to M Boström.
Levels and subcellular distributions of detoxifying enzymes in the ovarian corpus luteum of the pregnant and non-pregnant pig.
The levels and subcellular distribution of enzymes involved in defenses against reactive oxygen superoxide dismutase (SOD; E.C.1.15.1.1), glutathione peroxidase (GPX; E.C.1.11.1.9), catalase (CAT; E.C.1.11.1.6), and DT-diaphorase (DT; E.C.1.6.99.2) and of the conjugating enzymes glutathione transferase (GST; E.C.2.5.1.18) and p-sulphotransferase (p-ST; E.C.2.8.2.1) in the corpus luteum of ovaries from pregnant and non-pregnant pigs were investigated. In addition, non-protein thiols and glutathione reductase (GRD; E.C.1.6.4.2) were examined in the same manner. The total cytosolic activities of CAT, DT, GRD, and p-ST were significantly increased, whereas total GST activity was decreased in the pregnant corpus luteum compared to the corresponding activities in non-pregnant corpus luteum. In the case of the mitochondrial fraction from pregnant corpus luteum, GPX and GRD displayed significant increases in specific activity. Upon subfractionation of the mitochondrial fraction (i.e. mitoplast preparation), SOD activity was distributed equally between the mitoplasts and the supernatant. CAT and GPX activities were mainly recovered in the supernatant, while the major GRD activity pelleted with the mitoplasts. Microsomes from pregnant corpus luteum demonstrated increased specific GPX activity and decreased SOD activity compared to the non-pregnant corpus luteum. No differences in the non-protein thiol levels in the cytosolic, mitochondrial, or microsomal fractions from the corpus luteum were observed between non-pregnant and pregnant sows.
Animals↗
Enzymatic dissociation of keratinocytes from human skin biopsies for in vitro cell propagation.
Four techniques for dissociation of skin biopsies were compared to identify the method of choice for optimal expansion of isolated keratinocytes. Equivalent biopsies were obtained from 4 healthy human subjects and each divided into four parts. One part was minced and placed in a trypsinizing flask containing 0.05% trypsin and 0.01% ethylenediaminetetraacetic acid (EDTA). Released cells were harvested hourly. With the other parts, the epidermis was separated from the dermis after treatment with 0.5 mg/nml thermolysin, 2.5 mg/ml Dispase, or 0.17% trypsin and the epidermal portions were minced and incubated for 1 h in trypsin:EDTA. The cells were cocultivated with irradiated 3T3 fibroblasts to study the keratinocytes proliferative capacity. Freshly isolated cells were immunostained with anti-vimentin antibodies or grown in fibroblast-supportive conditions to detect the presence of human dermal fibroblasts. The mean number of cells dissociated per cm2 biopsy was higher after trypsin:EDTA digestion of a dermis-containing biopsy using a trypsinizing flask (4.0x 10(6) cells/cm2) compared to a biopsy where dermis-epidermis had been separated by thermolysin (2.8x 10(6) cells/cm2), Dispase (2.3x 10(6) cells/cm2) or trypsin (1.1 x 10(6) cells/cm2). Between 0.5% and 4% of the cells dissociated from a dermis-containing biopsy were human fibroblasts. This comprised more than twice the number of fibroblasts obtained by using epidermal/dermal split techniques. The proliferative capacity in primary and secondary culture was higher in cells isolated by trypsin:EDTA incubation in the trypsinizing flask or after epidermal-dermal separation using thermolysin, suggesting that Dispase or trypsin may have a more detrimental effect on the isolated keratinocytes. Our results show that dissociating the cells by trypsin:EDTA incubation in a trypsinizing flask or after epidermal-dermal separation using thermolysin, are preferable methods for isolating keratinocytes from human skin.
3T3 Cells↗
Intraosseous BMP implants in rabbits. Inhibitory effect on bone formation.
The bone harvest chamber is a model for rapid spontaneous bone healing in rabbits. We have previously shown inhibition of bone formation by using BMP-2 on a collagen carrier in this intraosseous model, despite bone formation when depositing BMP-2 on a similar carrier subfascially in the same animals. The doses were 12 and 0.6 micrograms/5 mm3 chamber volume. As these findings conflicted with most other experiments dealing with the skeletal response to BMP-2, we repeated the previous experiments with variations. We studied: 1) a lower BMP-2 dose, 2) a different type of BMP (BMP-7/OP-1), 3) a different carrier (hydroxyapatite), 4) a different chamber construction allowing contact with extraskeletal tissue and 5) BMP-2 on the original collagen carrier in an acutely inserted chamber in rats. We also studied the border between the BMP-2 implant and the preexisting bone to see whether BMP-2 caused premature differentiation of the callus so that proliferation was stopped and a bone cyst formed. The low dose of BMP-2 reduced tissue ingrowth and tended to reduce bone formation. BMP-7 showed the same inhibitory effects as BMP-2. BMP-2 on a hydroxyapatite carrier also inhibited bone formation in the chamber. In the chamber that allowed contact with extraskeletal tissue, we observed no effects of BMP-2. The border between the BMP-2 implant and the preexisting bone did not look like a cyst wall. BMP-2, from the same batch, on a similar collagen carrier, regularly increased bone formation in the acutely inserted bone chamber in rats, thereby excluding major defects in the BMP-2 implants. The inhibition in this specific model is a consistent finding and not due to an overdose, a specific BMP-type, a specific carrier or premature callus differentiation.
Animals↗
Transforming growth factor beta and bone morphogenetic protein 2 for bone ingrowth: a comparison using bone chambers in rats.
We compared the ability of transforming growth factor beta 1 (TGF beta 1) and bone morphogenetic protein 2 (BMP-2) to increase the penetration distances for fibrous tissue and bone into porous coralline hydroxyapatite. Forty-four rats received pairs of titanium bone chambers implanted bilaterally in their proximal tibiae. These chambers allow tissue ingrowth from one end of a long cylinder, so that ingrowth distances along the cylinder axis can be measured. Since bone never grows as far as fibrous or undifferentiated mesenchymal tissue, we measured both total tissue ingrowth and bone ingrowth distances. All chambers were implanted with cylinders of porous hydroxyapatite (Interpore 200). The hydroxyapatite cylinders were treated with either 1, 33, or 1000 ng of TGF beta 1 or BMP-2 prior to implantation, and compared with untreated contralateral control implants at 6 weeks. The bone ingrowth distance into the porous hydroxyapatite showed a trend toward inhibition with TGF beta 1 as compared to untreated controls (p < 0.08), and there was a negative correlation between TGF beta 1 dose and ingrowth distances for both bone (p < 0.01) and total tissue (p < 0.01). BMP-2 greatly increased bone (p < 0.001) and total tissue (p < 0.001) ingrowth distances.
Animals↗
Predilution hemofiltration. Clinical experience and removal of small molecular weight solutes.
Over 1500 treatments of hemofiltration with on-line preparation of substitution fluid were performed in 16 patients. Two patients were treated for over 40 months. On-line preparation of the solution allowed use of bicarbonate as a buffer. 73-74 L/session were infused in pre-dilution modality, at a rate of about 370 ml/min, and the treatment length was above 4 hrs. The good quality of on-line prepared solution was confirmed by the negativity of microbiological tests and by the absence of clinical or sub-clinical reactions in patients. Urea clearance was calculated by equations considering either plasma flow or whole blood flow. Results were 196-197 ml/min and 186-183 ml/min, respectively. The latter was nearer to the value of directly measured clearance (182-173 ml/min). Kt/V urea was about 1 per session and PCR ranged between 1.3 and 1.4 g/kg/day. A high vascular stability was also observed. Since sodium balance may, at least in part, account for better vascular stability, sodium sieving coefficient was measured during the treatment. The sodium-retaining effect of the increase of protein concentration within the filter, due to the ultrafiltration, was less relevant in pre-dilution hemofiltration if compared to post-dilution hemofiltration. It has been calculated that to obtain a sodium balance similar to that of the hemodialysis (HD), the sodium concentration of infusion solution should be about 2 mEq/L higher than HD dialysis solution. However, difficulty in performing accurate balance studies prevents a general agreement on these conclusions.
Acetates↗
[Quite simply, it was nice to have power. Interview by Kaj Nyman].
Explore the source record for details and available documents.
Humans↗
Clinical and microbiological evaluation of a postdilutional hemofiltration system with in-line production of substitution fluid.
Safety and efficacy of a recently developed hemofiltration (HF) system with in-line production of substitution fluid (GHS-10; Gambro, Lund, Sweden) based on a sterilizing filtration of acetate buffered dialysate has been evaluated in 4 patients over a 6-month period. Two patients were prematurely excluded from the study: 1 because of acetate intolerance and the other because of kidney transplantation. Two patients completed the study (240 HF sessions). Treatment adequacy was maintained in the 2 medium term treated patients according to the usual clinical and biochemical criteria and a mean exchange volume of 100-105 liters/week (30-35 liters/session three times weekly). Urea kinetic modeling analysis performed over all HF cycles gave the following results: dialysis index (urea clearance.time-on HF/urea volume space) (KT/V) approximately 1-1.1, urea time averaged concentration (UREA TAC) approximately 15-20 mmol/l, and protein catabolic rate (PCR) approximately 1.1-1.2 g/kg/day. Rare clinical adverse symptoms observed during the course of sessions were attributed to acetate intolerance. Microbiological safety was confirmed in vivo by the absence of pyrogenic reactions after 240 HF sessions (approximately 7 m3 substitution fluid infused intravenously) and in vitro by the constant absence of bacteria and/or endotoxin content limulus amaebocyte lysate (LAL) sensibility threshold 10 pg/l within the infusate produced during the sham HF sessions. The fluid mass balance obtained with the GHS-10 monitor was excellent. The electrolyte composition as judged by Na variation remained in a range of 2-3%. GHS-10 used in this study for postdilutional HF confirms that a large quantity of intravenous quality fluid may be safely produced by ultrafiltration from dialysate. It also introduced a new dimension in biocompatibility of dialysis by demonstrating that sterile dialysate may be routinely produced and used for routine dialysis.
Adult↗
Indirect effect of catecholamines on development of insulin resistance in skeletal muscle from diabetic rats.
The role of an increased sympathetic activation in the development of insulin resistance in diabetic skeletal muscle was investigated. Epitrochlearis muscles from rats with streptozocin-induced diabetes and from controls were incubated in vitro for 0.5-12.0 h. Diabetes decreased maximal insulin-stimulated (20 mU/ml) glucose transport capacity by 60% (P less than .001), but this decreased insulin responsiveness returned to normal on in vitro incubation (3.79 +/- 0.59 before vs. 8.92 +/- 0.64 mumol.ml-1.h-1 after 12 h of incubation). The reversal of decreased insulin responsiveness in diabetic muscles did not require the presence of insulin and was not affected by the presence of 5.0 x 10(-8) M of epinephrine. However, it was possible to partially prevent the development of insulin resistance with regard to glucose transport by treating the rats with the beta-adrenergic antagonist propranolol (0.5 mg/kg) every 12 h during the entire 72-h period in which the animals were kept diabetic (insulin responsiveness was 3.16 +/- 0.40 mumol.ml-1.h-1 for saline-injected group vs. 5.55 +/- 0.46 mumol.ml-1.h-1 for propranolol-treated group). This effect was not present after a single injection of the drug 2 h before the experiment or when propranolol treatment was withdrawn 12 h before the experiment. The beta-adrenergic blockade markedly reduced the plasma concentration of free fatty acids (0.5 +/- 0.01 mumol/ml for propranolol-treated rats vs. 1.1 +/- 0.1 mumol/ml for saline-treated rats; P less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)
Adrenergic beta-Antagonists↗