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L Ost

Publications and source records attributed to L Ost.

27 records · Page 2Linked to original sources
PubMed1982

Simultaneous determination of prednisolone and cortisol in serum by HPLC and by isotope dilution--mass spectrometry.

A reference method for the simultaneous assay of cortisol and prednisolone by isotope dilution-mass spectrometry has been developed. A fixed amount of 2H4-labelled cortisol is added to a fixed amount of serum. The mixture is then extracted, converted into methoxime-trimethylsilyl derivative, and subjected to analysis by combined gas chromatography-mass spectrometry. The ions at m/e 603, m/e 605 and m/e 609 are followed through the gas chromatography. These ions correspond to the M-31 ions in the mass spectrum of methoxime-trimethylsilyl ether derivative of prednisolone, unlabelled cortisol and 2H4-cortisol, respectively. With the use of a standard curve, the concentration of prednisolone can be calculated from the ratio between the peak at m/e 603 and the peak at m/e 609 and the concentration of cortisol can be calculated from the ratio between the peak at m/e 605 and the peak at m/e 609. The coefficient of variation was about 2% with respect to determination of prednisolone and about 3% with respect to determination of cortisol. This method was compared with a routine method based on high-performance liquid chromatography (HPLC) The coefficient of variation was 2-3% with respect to determination of cortisol and 1-3% with respect to determination of prednisolone. There was a good correlation between the isotope dilution method (x) and the HPLC method (y). In the assay of serum prednisolone the regression analysis gave the following equation: y = 1.02x -69 nmol/l, r = 0.99. In the assay of serum cortisol, the regression equation was: y = 1.07x-14 nmol/l, r = 0.95. It is concluded that the HPLC-method, used for routine determination of cortisol and prednisolone, has an accuracy sufficient for its intended use.

Chromatography, High Pressure Liquid↗
PubMed1982

Lymphatic transport of bile acids in man.

The possibility of a lymphatic transport of bile acids in man was investigated. Four patients were studied 2-4 weeks after renal transplantation. As a part of the postoperative immunosuppressive treatment they all had a thoracic duct fistula for lymphatic drainage. After a standardized meal, lymph and peripheral blood samples were simultaneously collected at 30-minute intervals for 210 minutes. The bile acids, cholic acid, chenodeoxycholic acid, and deoxycholic acid were assayed by a gas-liquid chromatography-mass spectrometry method using deuterium-labeled internal standards. The concentration of cholic acid was about the same in lymph and serum. The concentrations of chenodeoxycholic and deoxycholic acids were 2-3 times higher in lymph than in serum, both in the fasting state and postprandially. These results are explained by a more efficient passive absorption of the less polar dihydroxy bile acids. The transport of bile acids in the lymph was calculated to be only about 0.2% of that in the portal vein.

Adult↗
PubMed1981

Reduced steroid doses in cadaveric renal transplantation.

Commencing 1978, we reduced the initial dose of prednisolone to 40 mg/day against a former 120-200 mg/day for cadaver kidney recipients aged 60 years and above. The patient and graft survivals at 1 year which earlier had been 59 and 47% is 69 and 46% after the change (NS). From August 1980, we reduced the initial prednisolone dose to 30 mg/day for all recipients of cadaver kidneys. From the same time, all patients were given 5 units of leukocyte poor blood prior to the transplantation, and in addition, RATG (Stanford) was given during 2 weeks immediately following the transplantation. Preceding the reduction the patient and graft survivals at 6 months were 91 and 62% while they were 88 and 88% after the reduction (NS). The intravenous dose of methylprednisolone, which is used for the treatment of acute rejection, was reduced twice in this period, first from 6 to 3 g, and then to 1.75 g total dose. The proportion of rejections, successfully treated, had remained unchanged. Our preliminary results support the notion that it is possible to use lower steroid doses than previously in conjunction with cadaveric kidney transplantations. However, we have introduced other alterations of the routines which could have influenced the results.

Animals↗
PubMed1980

Cadaveric renal transplantation in patients of 60 years and above.

Between 1971 and 1977, 34 patients aged 60 years and above were treated with cadaveric renal transplantation in Stockholm. The survival figures were nearly the same as for patients of the same age group that had undergone long-term dialysis, with 2-year survival rates of 49 and 45%, respectively. Comparison with a younger group of transplant patients, ages 16 to 49, showed poorer patient and graft survival figures for the older patients, with 49 and 38%, respectively, after 2 years against 70 and 56% for the younger group. Complications were more frequent among the older patients, especially in regard to serious infections, heart conditions, and steroid diabetes. Irreversible rejection, on the other hand, was less common in the older group. On the basis of these findings, we intend continuing to offer renal transplantation to patients of 60 years and above. It would, moreover, seem worthwhile to try to reduce the dose of prednisolone in these patients.

Adolescent↗
PubMed1980

Steroid diabetes--a sign of overtreatment with steroids in the renal graft recipient?

The development of steroid diabetes was studied in a consecutive series of 114 patients receiving a cadaveric renal graft. All were first-time transplantations. For acceptance in the series the graft should have functioned for at least 2 weeks after the transplant operation. The median age of the patients was 52 years. The follow-up period was at least one year. The criterion for a diagnosis of steroid diabetes was an elevated fasting blood glucose concentration of more than 8 mmoles/l. Fifty-two of the patients (46 per cent) developed steroid diabetes. Thirty-four (65 per cent) of them required insulin therapy or peroral anti-diabetic drugs. The mean age of these patients was higher than for those not afflicted by this complication. The first-year mortality was significantly higher, 42 against 13 per cent, respectively (p less than 0.01). The level of significance was not notably affected by correction for age at transplantation. Severe infection was the cause of a large proportion of the deaths in the diabetes group. The findings suggest that the development of steroid diabetes can serve as a warning signal for excessive dosage of corticosteroids, and help to identify patients that are particularly sensitive to immunosuppressive therapy with large doses of steroids.

Adolescent↗