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Biomedical subjects

I Hermansson

Publications and source records attributed to I Hermansson.

18 recordsLinked to original sources
PubMed2001

Normal tissue response to low doses of radiotherapy assessed by molecular markers--a study of skin in patients treated for prostate cancer.

The aim of this study was to evaluate normal tissue response by molecular markers to multifraction low doses of ionizing radiation, with the focus on changes in repopulation, estimated using Ki-67 as the proliferation marker, and on expressions of the p53 and p21 proteins, identified as key proteins in the DNA damage checkpoint. Repeated skin biopsies were taken from patients treated for prostate cancer with radiotherapy. The expressions of Ki-67, p53 and p21 of the keratinocytes in the basal cell layer of the epidermis were quantified immunohistochemically. The dose to the basal layer was 1.1 Gy per fraction, given five times per week for seven weeks. The indices of the three markers were determined over the whole period. A significant suppression of the Ki-67 index was observed during the first weeks, followed by a significant gradual increase in the Ki-67 index over the last weeks. The p53 and p21 protein levels were almost zero in the unirradiated skin. Upon irradiation, both the p53 and p21 index increased in a pattern very congruent to the Ki-67 index. In conclusion, daily fractions of about 1 Gy to the skin resulted in, for the keratinocytes in the basal layer, a cell growth arrest for a couple of weeks and a subsequent acceleration in repopulation during the following weeks of irradiation. The present findings also provided novel insights into the role of the p53/p21 pathway in the response of a normal epithelium to ionizing radiation as it is applied in radiotherapy.

Biomarkers↗
PubMed1998

Direct injection of large volumes of plasma/serum on a new biocompatible extraction column for the determination of atenolol, propranolol and ibuprofen. Mechanisms for the improvement of chromatographic performance.

Very large volumes of serum/plasma can be directly injected to a new extraction column based on particles with a biocompatible outer surface and C18 groups within the pores. The biocompatibility has been obtained by attaching the human plasma protein alpha 1-acid glycoprotein to the outer surface of the particles. The pores are small enough to exclude the plasma protein molecules. Atenolol and propranolol were extracted on the extraction column as ion-pair with octanesulfonic acid as the counterion. The same counterion was used in the analytical mobile phase. A strong improvement of the recovery can be obtained using octanesulfonic acid as counterion in the extraction mobile phase. The recovery of atenolol increased from about 53.5% to about 93.4% using octanesulfonic acid as counterion. The chromatographic performance was also strongly affected by chromatography of the basic drugs as ion-pair with octanesulfonic acid. The improvement was due to trapping in a smaller section of the extraction column and enrichment of the drug on top of the analytical column. The enrichment was due to the transfer of the analyte to the analytical column in a zone with high concentration of counterion. Furthermore, the sample zone is compressed during the migration on the analytical column. The compression effect was caused by the counterion zone, migrating in front of the sample zone, giving the analyte higher retention on the front side than on the back side of the sample zone. Displacement of protein bound drug (ibuprofen) by addition of octanoic acid, was tested in order to study the influence on the recovery and the effect on the chromatographic performance. The recovery was improved and the chromatographic performance was greatly improved. The improvement obtained on the separation efficiency of ibuprofen was due to enrichment on top of the analytical column and compression during the migration through the analytical column. The enrichment was caused by a reduction of pH in the sample--octanoic acid zone transferred from the extraction column. The octanoic acid zone migrated in front of the sample zone giving a lower pH in front of the ibuprofen zone than behind. Thus, higher retention occurred in front of than behind the sample zone, which gave rise to compression. The methods developed for atenolol, propranolol and ibuprofen could be used for the determination of serum/plasma concentrations after single doses of the drugs with very high accuracy and precision. Linear calibration graphs were obtained and the r values were > or = 0.9999.

Adrenergic beta-Antagonists↗
PubMed1983

In vitro metabolism of propoxyphene in rat liver: reaction of a carbinol metabolite with acetaldehyde.

The metabolism of the analgesic drug propoxyphene (alpha-d-propoxyphene) has been investigated in the rat liver 9,000 X g supernatant fraction. The incubations were analyzed by HPLC. The major metabolite was norpropoxyphene carbinol, obtained through demethylation and ester hydrolysis. The demethylated metabolite of propoxyphene, norpropoxyphene, was also detected. Addition of acetaldehyde to the incubation mixture decreased the metabolism of propoxyphene. Reactions between norpropoxyphene carbinol and acetaldehyde resulted in a fast disappearance of the carbinol and the formation of a reaction product, the significance of which is discussed.

Acetaldehyde↗
PubMed1978

On the agalactia post partum in the sow. A clinical study.

The purpose of the present investigation was to study the clinical symptoms of agalactic sows post partum in randomly selected swine herds. The study comprised 71 sows affected with agalactia post partum and 71 healthy sows from the same herds used as controls. Average morbidity of the disease in these 50 herds, consisting of an average of 25 sows, was 12.8%. Sixty-three per cent of the agalactic sows were affected within one day after farrowing. There was no difference in gestation length between healthy sows and agalactic sows. The body temperature was significantly higher for affected than for healthy sows. Mastitis was diagnosed in 35 out of 71 agalactic sows. The criteria for mastitis were swelling and herdening of one or several udder glands. Vaginal discharge was recorded for affected sows (55/57) as well as for healthy sows (51/58) and is therefore not significantly associated with agalactia. The temperament of the agalactic sows was moderately or severely affected in 62 out of 71 agalactic sows. Constipation was recorded for 13/59 agalactic sows and for 3/57 normal sows. The agalactic sows had significantly higher number of piglets per litter at birth while the litter size was higher for healthy sows at weaning. Numerically, more sows were culled among agalactic sows (16/48) than among normal sows (6/42). Moreover, sows affected with agalactia at the previous parturition were more inclined to meet with the disease at the next parturition. Further studies comprising large groups of animals are, however, necessary for evaluation of this question.

Animals↗
PubMedDate not supplied

Use of a prostaglandin analogue (cloprostenol) for induction of parturition in pigs with prolonged gestation.

The effect of a prostaglandin analogue (cloprostenol) for initiation of parturition in sows with prolonged gestation (greater than or equal to 117 days) has been studied. The length of the period from injection to farrowing varied from 15 to 48 hours in sows with plasma progesterone level higher than 10.0 nmol/l at treatment, being on average 25.7 hours. Litter size at birth and at time of weaning are presented.

Animals↗