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Biomedical subjects

I Nilsson

Publications and source records attributed to I Nilsson.

At least 127 records · Page 7Linked to original sources
PubMed1985

Degradation of phenol by Pseudomonas putida ATCC 11172 in continuous culture at different ratios of biofilm surface to culture volume.

Pseudomonas putida ATCC 11172 was grown in continuous culture with phenol as the only carbon and energy source; a culture practically without biofilm was compared with biofilm cultures of differing surface area/volume ratios. The biofilm did not significantly affect the maximal suspended cell concentration in the effluent, but it increased the maximal phenol reduction rate from 0.23 g/liter per h (without biofilm) to 0.72 g/liter per h at the highest biofilm level (5.5 cm2 of biofilm surface per ml of reactor volume). The increase in phenol reduction rate was linear up to the surface area/volume ratio of 1.4 cm2/ml. The continuous cultures with biofilms could tolerate a higher phenol concentration of the medium (3.0 g/liter) than the nonbiofilm system (2.5 g/liter). At higher dilution rates an intermediate product, 2-hydroxymuconic semialdehyde, accumulated in the culture. When the biomass of the effluent started to decrease, the concentration of 2-hydroxymuconic semialdehyde reached a peak value. We conclude that biofilms in continuous culture have the potential to enhance the aerobic degradation of aromatic compounds.

Culture Media↗
PubMed1985

HTLV in Sweden: antibodies to HTLV I antigens in experimental monkeys and their caretakers.

252 monkeys kept at 4 different Swedish universities and laboratories for experimentation were screened for antibodies to HTLV I associated antigens by means of a sensitive membrane antigen enzyme immunoassay (MA-ELISA). 17/185 Macaca fascicularis, 1/56 M. mulatta, 0/1 Cercopithecus aetiops and 0/10 Saimirii squiureus had antibodies. All of 11 MA-ELISA positive animals which were subjected to further testing were also positive in a competition assay for anti-HTLV p19 antibodies and in an anti-whole virion enzyme immunoassay. One colony of 32 M. fascicularis monkeys from the Philippines contained 7 antibody-positive animals. Except for one M. fascicularis which suffered from a chronic dermal lesion, major disease was not observed in any of the antibody-positive animals. None of 28 animal caretakers or experimenters, of which several had been repeatedly exposed to blood from antibody-positive animals, had antibodies measurable by the MA-ELISA. The contagiosity for humans of the majority of the antibody-positive monkeys thus appears to be relatively low. We conclude that the presence in Sweden of HTLV I antibody-positive animals probably does not constitute a great health risk. However, we consider it appropriate that antibody-positive animals should be handled with special care.

Animals↗
PubMed1984

Studies on the causal relationship between gall-bladder emptying and motilin release in man.

Emptying of the human gall-bladder has previously been shown to be associated with the release of motilin, both in the fasting state and after various stimuli, such as oral intake of fat or water. Whether motilin causes emptying of the human gall-bladder or whether the peptide is released by gall-bladder emptying is not presently known. Recent animal experiments suggest that intravenous infusion of pure porcine motilin causes emptying of the gall-bladder, both in the pig and the dog. In the present investigation, neither a physiological nor a pharmacological one-hour infusion of pure porcine motilin caused emptying of the human gall-bladder. In contrast, manual compression of the gall-bladder, at the beginning of operation for large bowel carcinoma, was followed by motilin release. The one-hour integrated motilin response after gall-bladder compression was about 10 times greater than in the control patients in whom the motilin response after palpation of the liver was similarly calculated. We conclude that flow of bile into the proximal small bowel is a signal for the release of motilin from the peptide-producing cells in the gut mucosa.

Bile Acids and Salts↗
PubMed1983

Viral antibody screening system that uses a standardized single dilution immunoglobulin G enzyme immunoassay with multiple antigens.

We present an enzyme-linked immunosorbent assay (ELISA) system for the simultaneous determination of immunoglobulin G antibodies directed against several viruses. Antibodies to up to eight different viruses could be determined for three different sera on one microtitration plate. After subtraction of the absorbance values obtained with the control antigens, the viral antigen absorbancies were expressed as percentages of the absorbance obtained with a pooled immunoglobulin standard. This value, the relative antibody activity, was rapidly calculated by means of a computer directly connected to the ELISA photometer and was stored on magnetic disks, thereby facilitating seroepidemiological studies. The reproducibility of the relative antibody activity was calculated to at best +/- 3.6% (standard deviation) in an intraassay test and to at worst +/- 20.4% (standard deviation) in an interassay test. Each serum was analyzed only at a dilution of 1/75. The sensitivity of this single-dilution ELISA (SD-ELISA) method for the detection of titer rises was compared with those of conventional methods, mostly complement fixation but also hemagglutination inhibition. A total of 142 of 155 (92%) paired sera showing fourfold complement fixation or hemagglutination inhibition rises also showed significant results in SD-ELISA. A total of 22 of 57 (39%) significant relative antibody activity rises were significant in complement fixation or hemagglutination inhibition. Overall, up to twice as many significant titer rises could be detected with SD-ELISA. Most of these seemed to have a sound correlation with clinical data. The specificity of SD-ELISA was found to be similar to that of complement fixation, with some cross-reactions occurring between herpes simplex and varicella-zoster virus antigens and between parainfluenza viruses. We have found SD-ELISA to be a valuable clinical virological tool that supplements conventional serology.

Antibodies, Viral↗
PubMed1983

Axon diameter and myelin sheath thickness in nerve fibres of the ventral spinal root of the seventh lumbar nerve of the adult and developing cat.

The axon diameter (d) and the number of myelin sheath lamellae (nl) were estimated in electron micrographs of cross sectioned ventral spinal roots of the seventh lumbar nerve of adult cats, kittens and cat fetuses. Myelination started between the 40th and the 45th day after mating (about 3 weeks before birth). From birth onwards the calibre spectrum consisted of a group of small fibres and a group of large fibres. During the first two postnatal months the point distribution of the number of myelin lamellae plotted against the axon diameter appeared more or less linear. This point distribution pattern became curved from the 10th postnatal week onwards, and a function of the general expression: nl = C0 + C1d + C2 log(d) could be fitted to describe the regression. In adult cats, the mean number of myelin lamellae/axon diameter ratio was about 30 in the group of small and about 15 in the group of large fibres. Observations on immature animals indicated that the difference between the two fibre groups could have been established already during the third postnatal week. Considerable myelin production took place after the age of 1 year. The cross sectional area of the myelin sheath in the alpha fibre group increased about 10% after the age of 1 year, while in the gamma fibre group it increased as much as about 85%. The absolute amount of myelin per unit fibres. Differences and similarities between myelin production in the two fibre groups are discussed.

Animals↗
PubMed1976

Inhibition by estramustine phosphate on estradiol and androgen binding in benign and malignant prostate in humans.

Specific cytoplasmic androgen and estrogen binding has been measured in human benign prostatic hypertrophy and carcinomatous tissue. In vitro support for the binding of estramustine phosphate (Estracyt) to both estradiol- and dihydrotestosterone-binding sites is presented, which in part could explain the clinical effect of estramustine phosphate when pure estrogenic compunds are not effective.

Androgens↗
PubMedDate not supplied

Response of soluble IL-2 receptor, interleukin-2 and interleukin-6 in patients with positive and negative Borrelia burgdorferi serology.

This study was designed to investigate serum soluble interleukin-2 receptor (S-IL-2R), interleukin-2 (IL-2) and interleukin-6 levels (IL-6) in patients with either a positive or negative Borrelia burgdorferi serology. Serum samples from 101 individuals, divided in to five groups according to clinical symptoms and outcome of serology were analysed. Samples of cerebrospinal fluid (CSF) from nine of the individuals were also studied. The highest average serum S-IL-2R levels (1,180 +/- 1,140 U/ml) were found in patients with erythema migrans, the hallmark of Lyme borreliosis, followed by patients with symptoms closely related to Borrelia infection (900 +/- 1,200 U/ml) and with a strong positive serology. In two patients with central nervous system (CNS) involvement, increased levels of S-IL-2R of 920 and 620 U/ml respectively (normal value < 50 U/ml) were detected in the CSF. No statistically significant relationship between IgG or IgM antibody activity and serum S-IL-2R levels was found. Detectable levels of IL-2 were only found in three patients. Increased levels of IL-6 were found in sera from 14 patients. The highest concentration, 90 pg/ml (normal value < 10 pg/ml), was measured in a patient presenting with vasculitis. In conclusion, B. burgdorferi infection causes a moderate increase of serum S-IL-2R levels, although there is no relationship between the severity of the infection, as estimated by the antibody concentration or to serum IL-2 or IL-6 levels. Secondary complications of the infection, such as vasculitis, may cause an increased level of serum IL-6.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗