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Biomedical subjects

V Nielsen

Publications and source records attributed to V Nielsen.

24 records · Page 2Linked to original sources

Biosilon optimal culture conditions and various research scale culture techniques.

Research scale cultivations of L-929, MRC-5 and primary C.E. cells on Biosilon have shown that the most uniform cell attachment is obtained in systems, where the relative velocity between cells and beads is close to zero. In microcarrier cultures the attachment yield is lower compared with stationary systems, but the multiplication rate is the same or higher. The Tecam ACA-system and a rolling bottle system have proved to be promising systems for research scale.

Animals↗

Lymphocyte blastogenesis studied by volume spectroscopy.

The blastogenesis of human blood lymphocytes has been studied by measuring the distribution of cellular and nuclear volumes in concanavalin A (Con A)-stimulated leucocyte cultures by means of a modified Coulter counter. Agglutinated and adherent cells were dispersed by 3 h of incubation with alpha-methyl-mannoside and EDTA. Fresh suspensions contained 5--35% monocytes with an average cellular volume 2--2.5 times that of small lymphocytes. The nuclear volume of monocytes was similar to that of small lymphocytes within 10% and remained constant upon stimulation. In cultures given the optimal dose of Con A, 30 micrograms/ml, measurable cell growth commenced within 8--12 h, whereas nuclear growth began some 6 h later, which is approximately 6--8 h before increased 3H-thymidine incorporation could be detected. The average volume of responding cells grew by a factor of about 4 until mitosis, which started after around 48 h, whereas the average nuclear volume increased by a factor of about 3. The percentage of cells responding by volume growth increased with mitogen concentration even for hyperoptimal concentrations (150 micrograms/ml) which strongly suppressed 3H-thymidine incorporation. The results exemplify the type of information obtained by volume spectroscopy of leucocyte cultures. This method appears to have several advantages over conventional assays of immune response.

Cell Nucleus↗

Quantitation of protein adsorbance to glass and plastics: investigation of a new tube with low adherence.

Four different tubes were tested for adherence of human albumin, aggregated and non-aggregated human IgG and rabbit IgG: glass, polystyrene and cellulose nitrate tubes, and a new plastic tube, Minisorp. From the viewpoint of low protein adherence, the new tube was superior to the others, in the following test situation: (i) low concentration of proteins; (ii) 0.9% NaCl used as diluent; and (iii) when detergents in the tests are undesirable.

Adsorption↗

Liver impairment during chronic hemodialysis and after renal transplantation.

Liver impairment has been evaluated in a consecutive series of 79 patients with chronic renal failure of whom 23 were treated with hemodialysis alone and 37 with hemodialysis and renal transplantation alone. In half of the chronic hemodialysis patients and half of the patients receiving a renal allograft elevation of serum alanine aminotransferases was observed for a shorter or longer period during the study. In half of these cases from both groups the clinical course, laboratory data and liver histology were consistent with virus hepatitis and four patients died from fulminant hepatic failure. In the other half of the patients with elevated transaminases, this was either asymptomatic and unexplained or due to other causes such as septicaemia or urinary leakage. Liver biopsy showed unspecific changes. Renal transplantation was not performed in patients suffering from virus hepatitis, but 12 of the 37 patients who received a renal allograft had elevated aminotransferases at the time of transplantation. In seven of them a marked increase in aminotransferase was observed postoperatively, but none developed clinical sign of liver disease. It is concluded that elevated aminotransferase activity per se is no contraindication to surgical procedures, including renal transplatation, in these patients. However, a liver biopsy should be performed to detect a possible liver disease.

Alanine Transaminase↗