Biomedical subjects

M Göransson

Publications and source records attributed to M Göransson.

24 records · Page 2Linked to original sources

PubMed1984

Environmental temperature regulates transcription of a virulence pili operon in E. coli.

The expression in Escherichia coli K-12 of a pilus-adhesion determinant, obtained through molecular cloning from a pyelonephritic E. coli isolate, was studied at different temperatures. Strain HB101 carrying the recombinant plasmid pRHU845 agglutinated human erythrocytes after growth at 37 degrees C but not after growth at 22 degrees C. Quantitation of pilus subunit protein by an enzyme-linked immunosorbent assay (ELISA) for pilus antigen showed that synthesis of the pilus subunits was reduced at least 20-fold at 22 degrees C as compared with 37 degrees C. The 5' end of the pilus subunit structural gene, papA, was fused to the lacZ gene such that expression could be monitored at both translational and transcriptional levels. Measurements of beta-galactosidase production by the papA-lacZ hybrids provided evidence for thermoregulation of papA gene transcription. A regulatory determinant was localized to a 2-kb EcoRI-HindIII fragment encoding the papB gene and part of papA although none of the presently known pap gene products seem to be directly involved in a thermoregulatory mechanism. Comparison with other thermoregulatory systems in E. coli suggests that pap gene expression is regulated by a novel mechanism.

Base Sequence↗

PubMed1983

Correlation between nortriptyline and debrisoquine hydroxylation in the human liver.

The benzylic hydroxylation of nortriptyline (NT) and debrisoquine (D) by isolated human liver microsomes from eight subjects was studied. There was a strong correlation between the 10-hydroxylation of NT and the 4-hydroxylation of D (r = 0.96). The ability to hydroxylate D was also measured in vivo as the ratio between D and 4-OH-D in urine after oral administration of the drug to four subjects. This estimate of hydroxylation capacity agreed with the in vitro measurements. Liver microsomes from a subject defined as a poor in vivo oxidizer of D hydroxylated NT and D unusually slowly. Separation of microsomal proteins by SDS-gel electrophoresis indicated a relative lack of a cytochrome P-450 isozyme with a molecular weight of 54,500 in the liver from the poor oxidizer.

Adult↗

PubMed1983

Inulin single injection clearance. Microsample technique useful in children for determination of glomerular filtration rate.

The agreement between single injection inulin (polyfructosan) clearance and two reference methods for glomerular filtration rate (GFR) determination, namely standard inulin constant infusion clearance and 51-Cr-EDTA single injection clearance, was investigated. Studies were also made to see whether different results were obtained when capillary and venous blood samples were used in the single injection clearance method. The investigation was made in children from one year of age, adult patients and volunteers. For the single injection technique with inulin or 51-Cr-EDTA, five to seven blood samples were taken in a period of up to 180 min after injection. A bi-exponential plasma disappearance curve was used for calculations of single injection clearances. Good agreement was obtained between venous inulin single injection clearance on the one hand, and standard inulin clearance (correlation coefficient r = 0.86) and 51-Cr-EDTA single injection clearance on the other (r = 0.85). With use of capillary blood samples in inulin single injection clearance, similar good agreement was obtained both with venous 51-Cr-EDTA and with venous inulin single injection clearance (r = 0.85 and r = 0.89 respectively). From these results we conclude that inulin single injection clearance is a reliable method for GFR determinations. This method is recommended, especially in children, as capillary blood samples can be used.

Adolescent↗

PubMed1983

Evaluation of glomerular filtration rate in infants.

In the present study we investigated if inulin with single injection technique and capillary blood sampling can be used to determine glomerular filtration rate. Inulin single injection clearances using both venous and capillary samples were compared to standard inulin clearance (constant infusion) and to the clinical routine method, i.e. 51Cr-EDTA clearance. Good agreement was obtained between these different methods and it is concluded that the inulin single injection clearance is a reliable method for GFR estimation. Especially in children this method is recommended as capillary blood samples can be used and thus the high doses of radioactivity necessary for a 51Cr-EDTA capillary method can be avoided.

Adolescent↗

PubMed1975

Renal function in experimental chronic hydronephrosis. II. Backflow studies with radionuclides.

Studies of backflow in experimental unilateral chronic hydronephrosis in dogs with a known residual renal function and renal pelvic volume were performed with radioactively labelled substances with molecular weights of ca. 600, 5 200 and 68 000 placed in the hydronephrotic renal pelvis. Three different pressure levels in the renal pelvis were used. Isotope concentrations were determined in the thoracic duct lymph, 0lood and urine from the contralateral kidney. The greater part of the test substances appeared to pass to the blood circulation, while a smaller part was found in the lymphatic ducts. The largest molecule, however, was only able to leave the renal pelvis to any appreciable extent at the highest pressure. In kidneys with a low grade of hydronephrosis and well preserved function, a relatively large amount of test substance left the renal pelvis (ca. 10-15%). In more advanced grades of hydronephrosis with greater impairment of renal function, the backflow was considerably less.

Animals↗

PubMedDate not supplied

E- and Z-10-hydroxylation of nortriptyline by human liver microsomes--methods and characterization.

To enable in vitro characterization of nortriptyline 10-hydroxylase activity of microsomal fractions of human liver, methods for the determination of E- and Z-10-hydroxynortriptyline were developed. High performance liquid chromatography (HPLC) with UV-detection or HPLC separation followed by quantitation by gas chromatography-mass spectrometry were used. The microsomal 10-hydroxylation of nortriptyline was linear to 60 min with a protein concentration of 1 mg x ml-1. In 15 human livers a 5-fold variation in activity was found. The formation of the Z-isomer comprised 13 +/- 3% (mean +/- SD) of the total 10-hydroxylase activity. The 10-hydroxylation was inhibited by debrisoquine, sparteine, propranolol, and encainide. No effect or a stimulation of the activity was seen with p-nitroanisole and acetanilide.

Adult↗