Ethyl glucuronide (EtG): better than breathalyser or self-reports to detect covert short-term relapses into drinking

AIMS

The assessment of relapses is widely used as an outcome measure of alcohol dependence treatment. However, the methods of assessing relapses range from questionnaires to biological markers of alcohol for different time spans. The aim of this study was to compare the relapse rates of weekend home stays during long-term alcohol dependence treatment, assessed by ethyl glucuronide (EtG), breath alcohol tests and self-reports.

METHODS

Two hundred and ninety-seven alcohol-dependent patients receiving a long-term inpatient treatment programme participated. After a weekend at home (Friday to Sunday) they were evaluated for relapse by personal interviews and with breath alcohol tests. A concomitantly collected urine sample was later assessed for EtG with liquid chromatography-tandem mass spectrometry (LC-MS/MS analysis).

RESULTS

Of the total, 37.7% of the patients were positive for EtG at least once. Breath alcohol tests had been positive in only 4.4% and in personal interviews only 5.7% of the patients had admitted relapse. 15.6% of EtG tests were positive, but breath alcohol tests were negative (Cohen's kappa = 0.056). Ninety-three per cent of the relapses were only detected by EtG.

CONCLUSION

In addition to breath alcohol tests and interviews, urinary EtG can clearly improve the verification of relapse in inpatient treatment programmes allowing for weekend stays at home. Without EtG testing, a high amount of relapses will stay undetected.

Alpha-1-Fetoprotein (AFP): international proficiency study with different test systems

BACKGROUND

The present proficiency study aimed to elucidate the comparability and reliability of test systems for the determination of AFP concentrations.

METHODS

25 laboratories using 8 different commercial test systems used liquid BIOREF-AFP control serum in their routine internal quality control over a period of one year. For statistical analysis the results were collected centrally.

RESULTS

The statistical analysis of the test results revealed considerable variation for the different laboratories. The deviations of the mean values of different laboratories from the overall mean value varied between 0.1 and 26.1%, and for most of the laboratories the deviation was round about 10%. The precision of measured values in the individual laboratories was in most cases acceptable: Nevertheless, the coefficients of variation of the individual laboratories ranged from 13 to 16.1%.

CONCLUSIONS

In conclusion, this study indicates that AFP results vary between different laboratories albeit an international standard for AFP is available. Therefore, every laboratory should participate in external ring studies and should use a quality control serum independent of the test kit manufacturer for the internal quality control.

Blood gas partition coefficient and pulmonary extraction ratio for propofol in goats and pigs

The interpretation of continuously measured propofol concentration in respiratory gas demands knowledge about the blood gas partition coefficient and pulmonary extraction ratio for propofol. In the present investigation we compared both variables for propofol between goats and pigs during a propofol anaesthesia. In ten goats and ten pigs, expired alveolar gas and arterial and mixed venous blood samples were simultaneously drawn during total intravenous anaesthesia with propofol. The blood gas partition coefficient and pulmonary extraction ratio were calculated for both species. Non-parametric methods were used for statistical inference. The blood gas partition coefficient ranged between 7000 and 646,000 for goats and between 17,000 and 267,000 for pigs. The pulmonary extraction ratio ranged between 32.9% and 98.1% for goats and was higher for pigs, which ranged between -106.0% and 39.0%. The blood gas partition coefficient for propofol exceeded those for other known anaesthetic compounds so that it takes longer to develop a steady-state. The different pulmonary extraction rates in two species suggest that there are different ways to distribute propofol during the lung passage on its way from the blood to breathing gas. This species-specific difference has to be considered for methods using the alveolar gas for monitoring the propofol concentration in plasma.

Topical treatment of ocular surface defects: comparison of the epitheliotrophic capacity of fresh frozen plasma and serum on corneal epithelial cells in an in vitro cell culture model

Accelerated healing of ocular surface disorders was reported using serum for topical application. It is supposed that growth factors, fibronectin and vitamins in serum support the proliferation of corneal epithelial cells. The use of fresh frozen plasma (FFP) instead of serum is theoretically attractive, as it is more easily available from blood banks. In this study, serum and FFP were investigated for composition of epitheliotrophic factors and effect on corneal epithelial cells. Whole blood was taken from five donors. Serum and FFP were prepared, and the concentrations of epithelial growth factor (EGF), Platelet-derived growth factor (PDGF), transforming growth factor-beta1, fibronectin and vitamin A were determined. Immortalized human corneal epithelial cells were used to investigate growth, migration and differentiation in response to both blood products. Significant differences were found regarding the mediator composition of serum and FFP. Serum rather than FFP was significantly superior in stimulating cell growth, migration and differentiation. The epitheliotrophic capacity of blood products depends upon the composition of growth factors and vitamins. Blood clotting strongly influences the growth factor pattern. The superior epitheliotrophic capacity of serum might be due to the higher concentration of proliferation mediators such as EGF and PDGF and its higher content of vitamin A.

[Epitheliotrophic capacity of serum and plasma eyedrops. Influence of centrifugation]

BACKGROUND

Serum eyedrops are a new modality for the treatment of ocular surface disorders. We examined the influence of the preparation of blood products in a cell culture model and compared it with plasma.

MATERIAL AND METHODS

Serum and plasma were obtained from full blood of ten healthy volunteers and centrifuged at 500 and 3000 G. EGF, PDGF, TGF-beta1, fibronectin, and vitamin A were quantified by means of ELISA and HPLC. Cultures of human corneal epithelial cells were incubated with the four blood products in dose-response experiments and the intracellular ATP quantified.

RESULTS

EGF, PDGF, and vitamin A were present in serum in significantly higher concentrations than in plasma. The concentration of fibronectin was not influenced by the preparation. Support of proliferation was best by 25% platelet-poor serum. Serum supported the differentiation and migration of epithelial cells better than plasma.

CONCLUSION

The biochemical character of serum eyedrops is determined by the parameters chosen to produce the blood product. Plasma does not seem to offer an epitheliotrophic capacity equivalent to serum eyedrops. Their production should be optimized before any meaningful randomized controlled clinical trial can be attempted.

Attenuated salivary cortisol secretion under cue exposure is associated with early relapse

AIMS

To test whether the risk of relapse in alcohol dependence is predicted by the subjective experience of cue exposure (CE) and/or cortisol reactivity to alcohol cues.

METHODS

Salivary cortisol and self-ratings of 'tension' and 'desire to drink' were measured in 32 detoxified alcohol-dependent inpatients during CE sessions conducted in the first and third week of motivation enhancement therapy. Subjects completed the Toronto Alexithymia Scale (TAS-20) and the Abbreviated Alcohol Expectancy Questionnaire (B-AEQ) towards the end of the inpatient treatment to measure emotional self-awareness and the expected positive effects of alcohol.

RESULTS

Six weeks after the end of the inpatient treatment, 15 patients were abstinent. Relapse was verified or was presumed for 17 patients. Those who had relapsed had shown an attenuated response to CE in the third week as an inpatient but did not differ from abstainers in terms of subjective reaction to cues. Subjective ratings of CE were not related to salivary cortisol or relapse but showed several associations with factors one and two of the TAS-20. The expectancy of enhanced social contacts by using alcohol (factor 1 of the B-AEQ) correlated negatively with the decline in salivary cortisol during the CE session in the third week of treatment. Subjective ratings of CE correlated with Alexithymiascores.

CONCLUSIONS

Alcoholic patients who use alcohol to enhance their social contacts typically lack hypothalamo-hypophysical-pituitary-adrenocortical (HPA) reactivity in the early period of abstention. They are at an increased risk of early relapse and perhaps use alcohol to increase cortisol secretion again.

Accuracy of point-of-care-testing (POCT) for determining hemoglobin concentrations

BACKGROUND

While point-of-care testing (POCT) is being used increasingly as a basis for deciding on perioperative erythrocyte transfusion, no valid standards currently exist concerning the accuracy of Hb concentration measurements. For clinical employment, however, the confidence limits (+/-2 SD) of these measurements should lie close to 5 g/l. The aim of the present study was to evaluate the accuracy and precision of point-of-care testing for blood hemoglobin concentration (cHb in g/l) measurements in critically ill patients.

METHODS

Fifty blood samples from 50 postoperative patients requiring intensive care treatment were withdrawn from a cannula in the radial artery into a 2-ml heparinized syringe (containing wet sodium heparinate in the conus), in a 2-ml Monovette with 50 IE lithium heparinate, and into a 2.7-ml cuvette with 1.6 mg potassium EDTA/ml blood. The POCT battery consisted of two blood gas analyzers (ABLTM 625 and 725, Radiometer, Copenhagen), the HemoCue system (Mallinckrodt Medical, Germany), and an automated hematology analyzer (M-2000(R), Sysmex, Germany). The cyanmethemoglobin method served as the reference 'gold standard' procedure. The blood gas analyzer and HemoCue systems were tested using dry and wet heparinized blood samples.

RESULTS

Hemoglobin concentrations of the reference measurements ranged from 73.9 to 159.4 g/l. The automated hematology analyzer method did reveal a small but systematic deviation for higher cHb values. For the blood gas analyzer and HemoCue system procedures there was no systematic deviation of bias for either the first measurement or the averaged data. Bland & Altman analysis revealed a larger scattering for the wet heparinized samples.

CONCLUSIONS

The above-stated requirement for POCT systems, i.e. that the confidence limits should lie close to 5 g/l cHb, held true for the dry heparinized samples of the blood gas analyzer (1st measurement and mean of 2), the HemoCue system (mean of 3) and the automated hematology analyzer.

Development and evaluation of a video program for presentation prior to elective cardiac surgery

BACKGROUND

: The objective of the present study was to develop and evaluate the effects of a preparatory videotape on endocrine stress responses of patients prior to cardiac surgery and to analyze patient acceptance of this video for preoperative preparation.

METHODS

: 101 male patients prior to elective cardiac surgery were enrolled into the study. On the day before surgery, patients were assigned to one of the following groups: group 1 (n = 51) saw a video with realistic information about the upcoming perioperative procedure, and group 2 (n = 50) saw a video of the same length without surgery-related information. Venous blood was sampled before and 15 min after the video presentation. On the second postoperative day, patients filled in a questionnaire concerning their experiences of having preoperatively watched the video.

RESULTS

: After viewing the video, blood levels of cortisol, adrenocorticotropic hormone (ACTH), beta-endorphin, prolactin, epinephrine and norepinephrine in patients of group 1 were not significantly different compared to values measured before the video presentation. In patients of group 2, blood levels of cortisol, ACTH, prolactin and norepinephrine were significantly lower after video presentation compared to values obtained before the video. Patients of group 1 (compared to group 2) were significantly more often of the opinion that the video had helped in the preparation for surgery, and that they would like to repeat this adjunct preoperative video preparation in another similar situation.

CONCLUSION

: We conclude from our results that (i); cardiac surgical patients prefer preoperatively an adjunct surgery-related video preparation to a non-specific video presentation, and that (ii); preoperative preparation with realistic information about the upcoming medical procedure in patients undergoing cardiac surgery does not lead to an increase in endocrine stress hormone levels.

Detecting and quantifying absorbed irrigation fluid by measuring mannitol and sorbitol concentrations in serum samples, and by ethanol monitoring

OBJECTIVE

To describe a modified and improved technique which, in one measurement, estimates the influx of irrigation fluid during endoscopic endometrial ablation or prostate resection, and provides both rapid confirmation of the diagnosis and an estimate of the amount of fluid absorbed by detecting markers which pass from the irrigation fluid to the serum, i.e. mannitol or sorbitol.

PATIENTS AND METHODS

Control samples were taken for analysis before irrigation, and test samples were taken on four occasions during and after intervention, from each of 10 patients undergoing transurethral resection of the prostate. Irrigation fluid was also marked with ethanol (1.5% w/v) and the concentration of this agent measured in the blood and expired air of these patients. The absorbed volume was calculated according to the extracellular distribution space of mannitol.

RESULTS

Mannitol and sorbitol could be measured in 85% and 73% of the 40 test samples, respectively. The threshold for full sensitivity for breath ethanol concentration to detect absorption was 132 mL.

CONCLUSION

This method for detecting serum mannitol and sorbitol represents a valid procedure for confirming and quantifying the absorption of irrigation fluid in the clinic, which agrees closely with the already established ethanol monitoring procedure and which should now be considered as a reference procedure.

Blood levels of atrial natriuretic peptide, endothelin, cortisol and ACTH in patients undergoing coronary artery bypass grafting surgery with cardiopulmonary bypass

Previous studies demonstrated a biphasic time course with post-operative dissociation of blood levels of cortisol and ACTH in patients undergoing major surgery and critically ill patients. A possible role of endothelin and atrial natriuretic peptide (ANP) in the dissociation of concentrations of cortisol and ACTH in critically ill patients has been suggested. In the present study, we investigated the perioperative course of blood levels of endothelin, ANP, ACTH, and cortisol in 13 male patients undergoing cardiac surgery with cardiopulmonary bypass (CPB): group 1 consisted of 7 patients with an uneventful perioperative period and group 2 consisted of 6 patients with perioperative complications. Blood samples were taken pre-[T1], intra-[T2], post-operatively (on the day of surgery) [T3], as well as on the first [T4] and second [T5] post-operative days. Blood samples of endothelin, ANP, cortisol, and ACTH were measured using commercially available immunoassays. Perioperatively, a biphasic time course with post-operative dissociation of ACTH and cortisol concentrations was observed in all patients studied. Intraoperatively, during CPB, the highest levels of endothelin were found. Perioperatively, ANP and endothelin levels were elevated compared to pre-operative values up to the second post-operative day. On the second post-operative day, ANP concentrations were significantly higher in patients with complications in the perioperative period compared to those with an uneventful perioperative period. Our results suggest that: 1) plasma levels of ANP increased in patients with perioperative complications; 2) plasma levels of ANP may have prognostic value for patients undergoing cardiac surgery; and 3) the dissociation of ACTH and cortisol cannot solely be explained by the increase in endothelin-1 and ANP concentrations observed in patients undergoing major surgery.

Is there an analytical or diagnostic advantage from including trisialo transferrin into the fraction of carbohydrate-deficient transferrin? Lessons from a comparison of two commercial turbidimetric immunoassays with the carbohydrate-deficient transferrin determination by high-performance liquid chromatography

OBJECTIVES

Carbohydrate-deficient transferrin CDT has originally been defined as the sum of isotransferrins exhibiting isoelectric point values > or = 5.7 asialo, monosialo, and disialo transferrin but may also include at least in part trisialo transferrin when measured by modern commercial immunoassays. To examine the effects of divergently defining the analyte CDT, we compared two commercial assays yielding differently composed CDT fractions with a high-performance liquid chromatography HPLC assay commonly regarded as a reference method of CDT determination.

METHODS

Relative CDT levels (CDT concentrations expressed as percent of total transferrin) were determined in 142 sera by (i) a turbidimetric immunoassay (ChronAlco I.D.) reportedly detecting asialo to disialo transferrin as CDT, (ii) an analogous assay (CDT Turbidimetric ImmunoAssay [TIA]) said to additionally include part of trisialo transferrin into the CDT fraction measured, and (iii) an anion-exchange HPLC method. Isotransferrins separated by the two commercial assays were also investigated by isoelectric focusing.

RESULTS

Data from HPLC and isoelectric focusing indicate that the ChronAlco assay detects major parts of asialo, monosialo, and disialo transferrin as CDT while the CDT TIA yields CDT as the total of asialo, monosialo, disialo, and trisialo transferrin. When relative CDT concentrations obtained by both assays were classified as either normal or elevated according to reference ranges cited by the manufacturer and then were compared to analogously classified HPLC data, there were clearly more discrepancies between corresponding results from CDT TIA and HPLC (22%) than between ChronAlco and HPLC results (9%).

CONCLUSION

Including trisialo transferrin into the CDT fraction enlarges the analytical signal and therefore slightly improves assay precision but also results in a significant number of pathologic results in samples exhibiting physiologic levels of the classical CDT components asialo to disialo transferrin. As long as the diagnostic information of the trisialo transferrin concentration is largely unknown, we strongly recommend not to include this isotransferrin into the determination of CDT.

Blood levels of corticosteroid-binding globulin, total cortisol and unbound cortisol in patients undergoing coronary artery bypass grafting surgery with cardiopulmonary bypass

Previous studies have demonstrated a persistent rise in serum cortisol concentrations after cardiac surgery. To further investigate this finding and to evaluate the effect of hemodilution that occurs with the onset of cardiopulmonary bypass (CPB), concentrations of cortisol-binding globulin (CBG), total and unbound cortisol, and packed cell volume (PCV) were studied in 28 patients undergoing coronary artery bypass graft surgery. All patients received a standardized general anesthetic using a balanced technique with sufentanil, isoflurane, and midazolam. Blood was collected preoperatively, intraoperatively during CPB, and postoperatively in the evenings on the day of surgery and on the first and second postoperative day. Cortisol and CBG concentrations were measured by radioimmunoassay and were used to calculate the fraction of unbound cortisol. Serum CBG and cortisol concentrations corrected for hemodilution were significantly higher than non-corrected values. Perioperatively, CBG measurements were significantly intercorrelated. Intraoperatively, total and unbound cortisol concentrations were not significantly increased compared to preoperative values. Postoperatively up to the end of the study period serum concentrations of total and unbound cortisol were significantly increased compared to baseline values. Our results suggest that hemodilution occurs in all patients during cardiac surgery and continues up to the second postoperative day. This may lead to an underestimation of serum cortisol and CBG concentrations in patients undergoing heart surgery with CPB. Intraoperatively, concentrations of total and unbound cortisol were not significantly elevated. The postoperative rise in serum total cortisol concentration was accompanied by an increase in unbound cortisol concentration. The postoperative increase of unbound cortisol concentrations in patients undergoing cardiac surgery with CPB was largely due to an increase in cortisol secretion.

The immune-endocrine interaction varies with the duration of the inflammatory process in cardiac surgery patients

The present study investigated the perioperative course of cytokine release and hypothalamic-pituitary-adrenal (HPA) axis activation in relation to the duration of the inflammatory response in cardiac surgery patients. Twelve male patients scheduled for elective coronary artery bypass grafting surgery with cardiopulmonary bypass and general anaesthesia were divided into two study groups: group 1 (n=6) underwent surgery at 13.00 h+/-30 min, group 2 (n=6) at 08.30 h+/-50 min. Blood samples were collected preoperatively and up to the first postoperative day. Postoperatively, on the day of surgery, serum concentrations of the proinflammatory cytokines interleukin (IL)-6, IL-1beta and tumour necrosis factor (TNF)-alpha were not significantly different between the two groups, while blood concentrations of cortisol, adrenocorticotrophic hormone (ACTH) and beta-endorphin in group 2 patients were significantly higher than in group 1 patients. Postoperatively, on the day of surgery, ACTH and cortisol concentrations in group 1 patients were positively correlated to the blood concentrations of IL-1beta, IL-6 and TNF-alpha. By contrast, group 2 patients showed no significant relationship between cytokine release and activation of HPA axis at this time. Our results suggest that in patients undergoing cardiac surgery, the cytokine response is initiated before the HPA axis is fully activated. In the early postoperative period, cytokines appear to be involved in the activation of the HPA axis, while in the later postoperative period, high cortisol concentrations may inhibit the release of IL-6.

On-line analysis of electrolytes in extracorporeally circulating blood: application of a rat model to examine the effect of a single pharmacological dose of melatonin on electrolyte levels in blood

An experimental model was developed to study the kinetics of electrolytes under different physiological and/or pathological conditions. The model was applied to investigate in vivo the effect of a pharmacological dose of melatonin on the concentrations of Ca2+, K+, Na+, and pH in the anticoagulated blood of anaesthetized male Wistar rats (250-350 g). After the application of 0.25 mg melatonin/kg body weight, injected intraperitoneally into each of 8 rats, the electrolytes were measured by a flow-through system with highly sensitive ion-selective electrodes. The results were compared to a control group (n=8) which was treated with diluent (saline). The electrolytes were monitored continuously via an extracorporeal circulation, on-going for at least 60 min. Melatonin induced a significant increase of blood Ca2+ (p<0.02) by an average of 9.9% after 60 min. However, total calcium concentration did not increase significantly. The extracorporeal circulation provoked an elevation of K+ by hemolysis. This K+ increase was slightly diminished by melatonin (p<0.06). No melatonin effects were seen on Na+, pH and magnesium in blood and plasma, respectively. Also, the urine concentrations of the electrolytes were not altered by melatonin. The mechanism by which melatonin influences the blood concentrations of ionized calcium and potassium is not yet understood.

Can one really measure magnesium deficiency using the short-term magnesium loading test?

OBJECTIVE

To compare a 1-h-version of a magnesium-loading-test (MLT) designed for outpatients in healthy controls with the 8-h standard; to establish the test in patients after renal transplantation prone to develop magnesium (Mg) deficiency; to correlate femur Mg-concentration and percentage retention of the given load.

DESIGN

Comparison of mean values from healthy controls with respective from the literature; a prospective, randomized, controlled 4-month study; an intra-individual correlation of Mg-serum values and loading-test data with femur-Mg concentrations.

SETTING

One centre study in a medical university; outpatients from the transplant unit; inpatients from the orthopedic unit.

SUBJECTS

Twenty-four healthy controls aged 36.7 +/- 7.4 years; 34 patients after renal transplantation (46.5 +/- 14.3 years); 41 patients with hip replacement therapy (63.9 +/- 18.6 years).

INTERVENTION

Baseline Mg values were measured by atomic absorption spectroscopy (AAS) in serum and urine. An intravenous Mg load with 0.1 mmol Mg-aspartate hydrochloride per kilogram bodyweight was given during 1 h. In 24 h-urine, the amount of excreted Mg was measured by AAS and the percentage retention of the given load calculated according to the formula: 1 - [Mg 24 h-urine/Mg test dose] x 100. Femur Mg was measured by AAS in a peace of the femur neck. Patients after renal transplantation were randomized after the first Mg load to either obtain daily 5 mmol Mg-aspartate hydrochloride per kilogram bodyweight, or placebo. Four months later a second loading-procedure was performed.

MAIN OUTCOME MEASURE

Serum Mg, percentage retention of the given Mg load (%Ret) and femur Mg concentration.

RESULTS

Mean serum Mg values were within the normal range. In controls, %Ret was -18 +/- 21 and not different from the literature. In the first MLT after renal transplantation, %Ret was 47 +/- 43. In patients under Mg medication it decreased significantly to 16 +/- 26, but was 58 +/- 27 in the placebo group. Femur Mg concentration was 62.6 +/- 20.9 mmol kg-1 dry substance and the corresponding %Ret was 14 +/- 28 with r = - 0.7093.

CONCLUSION

The short-term version of the MLT is as good as the standard and was easily applied in outpatients. The indication from the good correlation between bone-Mg and %Ret and a marked decrease in %Ret in patients after Mg medication was that one can really measure magnesium deficiency.

Allopregnanolone in women with premenstrual syndrome

5Alpha-reduced metabolites of progesterone, especially 3alpha-hydroxy-5alpha-pregnan-20-one (allopregnanolone) are now listed to neurosteroids. Their anesthetic properties can be explained by their allosteric interaction with GABA(A) receptors. A woman's organism is provided with an abundance of progesterone during the luteal phase of the menstrual cycle and its level falls down sharply with the first day of menses. The level of allopregnanolone follows that of progesterone. Many women suffer from so called premenstrual syndrome (PMS) during the luteal phase. In this study we have determined allopregnanolone and progesterone levels and their ratios in order to assess the over-all activity of C21-steroid 5alpha-reductase in these patients and in controls. Significantly lower levels of both progesterone and allopregnanolone than in controls have been found in PMS patients in the follicular phase only.

Persistent endocrine stress response in patients undergoing cardiac surgery

To investigate the endocrine stress response in patients undergoing major surgery with general anesthesia using a balanced technique with sufentanil, isoflurane and midazolam up to the second postoperative day, blood levels of cortisol, epinephrine, norepinephrine, prolactin and growth hormone were determined in 68 males for elective coronary artery bypass grafting (CABG) surgery. Intraoperatively, during extracorporeal circulation none of the measured parameters were significantly increased compared to preoperative values. The endocrine response of patients with perioperative epinephrine medication (n = 32) was not significant different to patients that did not receive exogenous epinephrine (n = 36). On the evening of the day of surgery, levels of cortisol (3 fold), epinephrine (4.7 fold), norepinephrine (1.7 fold) and growth hormone (16.5 fold) were significantly increased. Compared to preoperative values levels of cortisol (3.3 fold), growth hormone (5.5 fold) and norepinephrine (1.8 fold) remained elevated up to the evening of the second postoperative day. In conclusion, the endocrine stress response in patients undergoing CABG-surgery under general anesthesia with sufentanil, midazolam, isoflurane is intraoperatively prevented by anesthesia. Although hemodilution or hormone degradation might be responsible for the lack of an increase in endocrine parameters during CPB, this study indicates that a balanced technique with isoflurane, sufentanil and midazolam is more effective in blocking the endocrine stress response than previously described anesthetic techniques. In the early postoperative period, a sharp increase in cortisol, epinephrine, norepinephrine and growth hormone occurred suggesting that the predominant endocrine stress response begins in the intensive care unit with end of anesthesia. The postoperative elevated levels of cortisol, growth hormone and norepinephrine indicate a persisting stress-response for more than two days after surgical trauma.

Molecular genetic analysis and human chorionic gonadotropin stimulation tests in the diagnosis of prepubertal patients with partial 5 alpha-reductase deficiency

Reduced conversion of testosterone (T) to dihydrotestosterone (DHT) results in defective virilization in karyotypic males. Different mutations in the 5 alpha-reductase type 2 gene cause the phenotypic variability of the disease. In this report we describe four prepubertal patients with a predominantly male phenotype who carry homozygous point mutations in the 5 alpha-reductase type 2 gene and address the specific T and DHT response to different human chorionic gonadotropin (hCG) stimulation tests. For molecular genetic analysis, DNA from peripheral blood leucocytes was studied. The coding region of the 5 alpha-reductase type 2 gene was characterized by exon-specific polymerase chain reaction amplification, non-radioactive single strand polymorphism analysis, and direct sequencing. Three different homozygous point mutations (Gly196-Ser, Arg227-Gln and Ala228-Thr) were identified in the patients. In contrast, in the DNA from 100 phenotypically normal males only two heterozygous abnormalities (Ile196-Ile, delta Met157) were characterized. For hormonal studies, T and DHT were measured in serum before and after hCG stimulation employing different protocols. HCG stimulation with 5000 IU/m2 once and prolonged stimulation with seven injections of 1500 IU hCG per single dose every other day were used.

CONCLUSION

While abnormal T/DHT ratios were identified with both hCG protocols in the patients, prolonged stimulation lead to higher T values and to higher T/DHT rations, and hence to a better discrimination of pathologic results.

Phenotypic classification of male pseudohermaphroditism due to steroid 5 alpha-reductase 2 deficiency

Conversion of testosterone (T) to dihydrotestosterone (DHT) in genital tissue is catalysed by the enzyme 5 alpha-reductase 2, which is encoded by the SRD5A2 gene. The potent androgen DHT is required for full masculinization of the external genitalia. Mutations of the SRD5A2 gene inhibit enzyme activity, diminish DHT formation, and hence cause masculinization defects of varying degree. The classical syndrome, formerly described as pseudovaginal perineoscrotal hypospadias, is characterized by a predominantly female phenotype at birth and significant virilization without gynecomastia at puberty. We investigated nine patients with steroid 5 alpha-reductase 2 deficiency (SRD). Phenotypes, which were classified according to the severity of the masculinization defect, varied between completely female (SRD type 5), predominantly female (SRD type 4), ambiguous (SRD type 3), predominantly male with micropenis and hypospadias (SRD type 2), and completely male without overt signs of undermasculinization (SRD type 1). T/DHT-ratios were highly increased ( > 50) in the classical syndrome (SRD type 5), but variable in the less severe affected patients (SRD types 1-4) (14-35). Mutations in the SRD5A2 gene had been characterized using PCR-SSCP analysis and direct DNA sequencing. A small deletion was encountered in two patients, while all other patients had single base mutations which result in amino acid substitutions. We conclude that phenotypes may vary widely in patients with SRD5A2 gene mutations spanning the whole range from completely female to normal male without distinctive clinical signs of the disease. Hence, steroid 5 alpha-reductase deficiency should be considered not only in sex reversed patients with female or ambiguous phenotypes, but also in those with mild symptoms of undermasculinization as encountered in patients with hypospadias and/or micropenis. A classification based on the severity of the masculinization defect may be used for correlation of phenotypes with enzyme activities and genotypes, and for comparisons of phenotypes between different patients as the basis for clinical decisions to be made in patients with pseudohermaphroditism due to steroid 5 alpha-reductase 2 deficiency.

Estrone sulfate analogs as estrone sulfatase inhibitors

The high serum concentration of estrone sulfate and the presence of estrone sulfatase in breast tumors constitute an important mechanism of local synthesis of estrogens in the tissue. Thus, inhibitors of estrone sulfatase may be effective in the treatment of estrogen-dependent breast cancer. In this study, we synthesized several isostructural analogs of estrone sulfate (estrone-3-methylsulfonate, estrone phosphate, 3-desoxyestradiol-3-methylenesulfonate, and 3-desoxyestrone-3-methylenesulfonate) and tested them on human placental sterylsulfatase. The results were (i) The Ki of 3-desoxyestrone-3-methylenesulfonate 12 and 3-desoxyestradiol-3-methylenesulfonate 7 are more than 100-fold higher than the Ki or KM values for estrone sulfate, (ii) As compared to estrone sulfate, the Ki value for estrone-3-methylsulfonate 2 is about 30-fold higher, while estrone phosphate 3 is bound by the sulfatase with roughly the same affinity as estrone sulfate. The results shed some light on the electronical and sterical requirements for high affinity binding to the enzyme.

A novel radioimmunoassay of allopregnanolone

A radioimmunoassay for determination of 3 alpha-hydroxy-5 alpha-pregnan-20-one (allopregnanolone) in serum or plasma has been developed and evaluated. The method employs rabbit antiserum to 3 alpha-hydroxy-5 alpha-pregnane-11,20-dione-11-O-carboxymethyloxime bovine serum-albumin conjugate and tritiated radioligand. The main cross-reactant interfering in the assay, progesterone, is eliminated by permanganate oxidation. Two assay variants were compared, with and without a micro-column chromatography. The simplified variant appeared to be reliable enough for determination of allopregnanolone in normally menstruating women at luteal phase, whereas the column-chromatography step is necessary when analyzing samples of expected low analyte concentration as in women in follicular phase, postmenopausal women, or in men. The levels of allopregnanolone in healthy women correlated excellently with progesterone in agreement with previous findings.

Inhibition of human placental sterylsulfatase by synthetic analogs of estrone sulfate

Synthetic analogs of estrone sulfate which carry differently substituted sulfonyl groups at position 3 of an invariable 3-desoxyestrone (dE1) moiety were tested in vitro as inhibitors of the human placental sterylsulfatase. Using both placental microsomes and a highly purified placental sterylsulfatase preparation as the enzyme source and dehydroepiandrosterone [35S]sulfate or estrone [35S]sulfate as the substrate, the following order of inhibitory potencies was observed: dE1-3-sulfonylchloride > dE1-3-sulfonylfluoride approximately dE1-3-sulfonate > dE1-3-sulfonamide approximately 3-methylsulfonyl-dE1. According to the results, the association of enzyme and inhibitor appears to be favored by an electronegative substituent at the sulfur atom (-C1, -F, -O-). Since, however, even the most potent synthetic inhibitor was bound by the enzyme with significantly lower affinity than was the natural substrate estrone sulfate, an oxygen function between the aromatic ring and the sulfur atom may be necessary for high affinity binding towards the sterylsulfatase. In addition to its fast reversible association with the enzyme, dE1-3-sulfonylchloride further affected the sulfatase activity in a time-dependent manner. This latter inhibitory activity which may be due to a covalent modification (alkylation) of sterylsulfatase by the analog was partially prevented in the presence of substrate.

Sterylsulfatase expression in normal and transformed human placental cells

Isolated cytotrophoblast cells and choriocarcinoma cell lines are commonly applied in-vitro systems for the study of human placental endocrine function. We tested these normal and transformed placental cells for expression of the enzyme sterylsulfatase which is necessary for the production of free steroids from sulfoconjugated precursors in the placenta as well as in other human tissues, and compared the results with respective data obtained from term placental tissue. Specific sterylsulfatase activity was highest in placental homogenates but was lower by about a factor of 5 to 10 in homogenates of freshly isolated cytotrophoblast or JEG-3 cells and by about a factor of 100 in BeWo cell homogenates; the enzyme activity could not be detected in Jar cells. Sterylsulfatase mRNA levels as analyzed by Northern blotting roughly paralleled the levels of enzyme activity measured in cytotrophoblast, JEG-3, and BeWo cells; in Jar cells, RNA species complementary to the specific probe were clearly detectable but differed by size from the mRNA species found in the other cells. Our results indicate that sterylsulfatase activity is differently expressed in normal and transformed placental cells due to different rates or products of gene transcription in these cells.

Weighted serum pools in comparison to the trapezoidal rule for estimating AUCs for ethinyl estradiol. The relationship of the variance of the determination to the interindividual variance

The concept of a weighted pool for estimating the area under the curve (AUC) is presented and set in relationship to the trapezoidal rule. An example from a pharmacokinetic study on ethinyl estradiol is used to demonstrate the use of variance component analysis for relating the intraindividual variance of the AUC, trapezoidal rule and weighted pool to the variance of the determination process. Depending on the sampling times, the theoretical variance of the weighted pool is greater than the theoretical variance of the trapezoidal rule. In the example presented, it was shown that this difference is of no importance in relation to the interindividual variance of the AUC, which dominates the total variance. In the example study, routine quality control samples were also determined in each assay, which allowed independent confirmation of the discussed results on the intraindividual variance of the AUCs.

Pharmacokinetics of gestodene and ethinylestradiol in 14 women during three months of treatment with a new tri-step combination oral contraceptive: serum protein binding of gestodene and influence of treatment on free and total testosterone levels in the serum

The pharmacokinetics of gestodene (GEST) and ethinylestradiol (EE2) were determined in 14 healthy women (age 18 to 32 years) during a treatment period of three months with a new tri-step combination oral contraceptive (Milvane). Prior to this treatment period, the same women received a single administration of a coated tablet containing 0.1 mg GEST together with 0.03 mg EE2. There was a wash-out phase of one week between both treatments. Following single dose administration, a mean terminal half-life of 18 h was observed for GEST. The total clearance was 0.9 ml x min-1 x kg-1 and the volume of distribution was 84 l. During a treatment cycle, GEST levels in the serum accumulated by a factor of 8 as compared to single dose administration. Steady-state drug levels were reached during the second half of each cycle. As compared to single dose administration, the following changes were observed for GEST at the end of treatment cycles one and three: prolonged terminal half-life (20 to 22 h), reduced total (0.16 ml x min-1 x kg-1) and free clearance (ca. 27 ml x min-1 x kg-1), reduced volume of distribution (ca. 18 l). A concomitant EE2-induced increase in the SHBG concentrations by a factor of three as compared to pretreatment values was observed during a treatment cycle and appeared to be mainly responsible for the changes in the pharmacokinetics of GEST. Marked changes were also seen for the serum protein binding of GEST. After single dose administration, the free fraction of GEST was 1.3% and the fractions bound to SHBG and albumin were 69.4% and 29.3%, respectively. At the end of cycle one, the free fraction was only 0.6% and the fractions bound to SHBG and albumin were 81.4% and 18.0%, respectively. There was no difference in corresponding pharmacokinetic parameters and in the serum protein binding of GEST at the end of cycles one and three. On the last day of treatment cycles one and three, the AUC(0-4h) values of EE2 were 299.2 and 278.1 pg x ml-1 x h, respectively, which corresponds to an about 30% increase as compared to single dose administration, where an AUC(0-4h) value of 216.1 pg x ml-1 x h was found. Total and free testosterone concentrations decreased during treatment cycles one and three by about 36% and 60%, respectively, compared with the corresponding values measured prior to treatment. The fraction of unbound testosterone thus decreased from 0.5% to 0.3% during treatment.

Pharmacokinetics and protein binding of gestodene under treatment with a low-dose combination oral contraceptive for three months

The serum concentrations of gestodene (CAS 60282-87-3) as well as the binding of this progestin to serum proteins were studied in 40 women who took a low-dose oral contraceptive (Femovan, Femodene) containing 30 micrograms ethinyl estradiol (CAS 57-63-6) and 75 micrograms gestodene for 3 months. On days 1, 10, and 21 of the first and the third treatment cycle, respectively, 7 blood samples were drawn before and up to 4 h after pill intake; additional samples were taken prior to morning ingestion of pill on days 2, 5, 11, 15 and 22 of these cycles. Gestodene levels were measured by means of a specific radioimmunoassay and were evaluated for Cmax, tmax, and AUC up to 4 and 24 h. Independent of the test day and the treatment cycle studied, mean maximum gestodene serum levels were found about 0.8 to 0.9 h after pill intake. During the first treatment cycle, mean values of Cmax, AUC(0-4h), and AUC(0-24h) amounted to 4.3 ng.ml-1, 9.3 ng.ml-1.h, and 27.3 ng.ml-1.h on test day 1; these values increased by 250-400% and by 300-500%, respectively, when days 10 and 21 were compared to day 1. On day 1 of the third treatment cycle, these pharmacokinetic parameters were higher by almost a factor of two as compared to the corresponding data obtained on the beginning of the first cycle whereas the increase of these values between day 1 and the subsequent test days (200-300%) was slightly lower in cycle 3 as compared to cycle 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Human placental sterylsulfatase. Interaction of the isolated enzyme with substrates, products, transition-state analogues, amino-acid modifiers and anion transport inhibitors

The enzymatic properties of a homogeneous sterylsulfatase preparation isolated from human term placenta were studied. The enzyme exhibited both arylsulfatase and sterylsulfatase activity: it catalysed the hydrolysis of sulfuric acid esters of (in the order of decreasing specific activity) non-steroidal phenols, of a phenolic steroid, and of neutral 3 beta-, 21- and (though at a very low rate) 17 beta-hydroxysteroids. However, among all the substrates tested only the 3-sulfates of phenolic and neutral steroids exhibited high affinity towards the sulfatase. Vitamin D3 sulfate was not hydrolysed by the sterylsulfatase but strongly inhibited its activity. The products of the catalytic reaction, free steroids or phenols as well as the sulfate anion or analogues thereof, likewise interfered with the enzyme's activity. Ki values of unconjugated steroids were ten- to hundredfold higher than Km values of the respective sulfoconjugates. Inorganic sulfate only slightly inhibited the sulfatase activity; its inhibitory potency, however, increased in a time-dependent manner when it was preincubated with the enzyme prior to assay. In contrast to sulfate, the hypothetical transition-state analogues sulfite and vanadate acted as strong inhibitors of the sulfatase activity. According to the results of an analysis of the effect of pH on sterylsulfatase kinetics, enzyme constituents with pK values of approximately 5.8 and 8.0 are involved in a general acid-base catalysed reaction. Treatment of the sulfatase with amino-acid side chain modifying reagents directed against arginine, cysteine, cystine, serine or tyrosine residues did not result in significant alteration of its activity. Diethyl-pyrocarbonate known to react primarily with histidyl groups, however, rapidly inactivated the enzyme; this inactivation reaction was markedly retarded in the presence of substrate. Histidine thus appears to be essential for the catalytic activity of the sulfatase. Taken together, the present results reveal a considerable similarity between the catalytic mechanism of human placental sterylsulfatase and the ones already proposed for the lysosomal arylsulfatases A and B. Taurocholate, salicylate, ouabain, and 4,4'-substituted stilbene-2,2'-disulfonates are well known inhibitors of carrier-mediated transport of anions across cellular membranes. With the exception of ouabain, these compounds likewise turned out to inhibit the enzymatic hydrolysis of steryl sulfates; the pattern of dose dependences of their interference with the sulfatase activity resembles the one reported for inhibition of anion transport. Since the sterylsulfatase in vivo strongly is associated with cellular membranes including the plasma membrane of the syncytiotrophoblast, this finding supports the speculation that similar molecular structures may be involved in both placental transport and hydrolysis of anionic steryl sulfates.

Group comparison of serum ethinyl estradiol, SHBG and CBG levels in 83 women using two low-dose combination oral contraceptives for three months

Serum ethinyl estradiol (EE2), sex hormone-binding globulin (SHBG) and corticosteroid-binding globulin (CBG) concentrations were studied in healthy young women randomly allocated to one of two low-dose combination oral contraceptives containing 30 micrograms EE2 and either 75 micrograms gestodene (F) or 150 micrograms desogestrel (M) per unit. There was either no (formerly non-pill users) or one (pill users) wash-out cycle before the study started with a pill-free pretreatment cycle in which the hormone status and basal SHBG and CBG levels were measured. Treatment was for three months. During treatment cycles 1 and 3, there were three test days each. Seven serum samples were obtained up to four hours and one sample 24 hours after intake of the first, tenth and the last (21st) pill. Additional samples were taken prior to morning ingestion of pills 5 and 15. For each individual and each test day, a representative serum pool has been constructed for SHBG and CBG analysis. EE2 concentrations were analyzed in all individual samples by means of a specific and sensitive RIA using anti-EE2-6 beta-CMO-BSA antiserum. Area under the curves (AUC) up to 4 and 24 hours, Cmax and tmax were evaluated and compared between the two treatment groups (n = 40 for F, n = 43 for M). SHBG and CBG concentrations were measured using commercially available immunoassay kits. Groups were large enough to detect a difference in group means of 75% of one standard deviation (alpha = 0.05, 1-beta = 0.9) of target variables, which is equivalent to 28 pg EE2/ml for Cmax, 69 pg.h.ml-1 for AUCEE2 0-4h, 257 pg.h.ml-1 for AUCEE2 0-24h, 39 nmol/l SHBG and 13.4 micrograms CBG/ml. Results clearly demonstrate that there were no differences between the two treatment groups in any of the target variables at any of the six test days distributed over a three-month period. Mean SHBG and CBG pretreatment levels of about 70 nmol/l and 37 micrograms/ml, respectively, increased to about 210 nmol/l and 88 micrograms/ml during the first treatment cycle and to about 230 nmol/l and 93 micrograms/ml during the third treatment cycle. Whereas the time of maximum EE2 serum levels did not differ significantly between test days, Cmax, AUCEE2 0-4h and AUCEE2 0-24h values increased by 30-35% or 40-50%, respectively, when test days 10 and 21 were compared to test day 1. Similar results were found for the third treatment cycle.(ABSTRACT TRUNCATED AT 400 WORDS)

Human placental sterylsulfatase: immunocytochemical and biochemical localization

Human placental sterylsulfatase was localised in situ by light and electron microscope immunocytochemical techniques as well as in homogenate and tissue extract fractions by enzyme assays. Light microscope observations on frozen sections of term and preterm placenta revealed sterylsulfatase immunoactivity primarily in the syncytiotrophoblast. Electron microscope observations confirmed the light microscope findings; in addition, they showed that the sulfatase is present in the endoplasmic reticulum of endothelial cells, too. In the syncytiotrophoblast, the enzyme was detectable in the cytoplasmic membrane of the nuclear evelope, in the membranes of the rough endoplasmic reticulum, in the plasma membrane with predominant localisation in coated pits, and in the membranes of endosomes and multivesicular bodies; little or no reactivity was detectable over the membranes of the Golgi complex and of lysosomes. Sterylsulfatase immunoactivity was absent in placentas with hereditary sterylsulfatase deficiency. The observations indicate that human placental sterylsulfatase is normally present in the membranes of compartments along the secretory pathway and the endocytic route of cells lining the fetal and maternal blood. Homogenates of normal term placenta as well as membrane vesicle preparations obtained by extraction of trophoblast tissue with isotonic saline were fractionated by differential centrifugation; the fractions were assayed for specific activities of sterylsulfatase and several marker enzymes of cellular topography. In agreement with our immunocytochemical findings, the results of these biochemical localisation experiments indicate the repeatedly described association of the placental sterylsulfatase with microsomal membranes but also point to the presence of the enzyme's activity in the microvillous plasma membrane of the syncytiotrophoblast. This localisation of sterylsulfatase may have functional implications in the placental uptake of circulating steroid sulfates.

2- and 4-iodinated estriol as indicator ligands for estriol radioimmunoassays with anti-estriol-C6 conjugate antiserum

The suitability of 2- and 4-125I-estriol as indicator ligands for estriol determination in radioimmunoassays with anti-estriol-C6 conjugate antiserum was tested and compared to the one of 3H-estriol, estriol-6-(O-carboxymethyl)oxime-125I-histamine and a commercially available 125I-estriol derivative of unknown structure. An ideal radioiodinated tracer would react identically with the analyte and its tritiated analogue and the 4-monoiodo-estriol was found to fulfil these requirements as shown by the pattern of dilution and standard curves obtained with the various labeled ligands. This observation was corroborated by a comparison of the apparent estriol concentrations in human pregnancy sera determined with the different indicator ligands. The experimentally proven advantage of 4-monoiodo-estriol over other iodinated estriol derivatives verifies a hypothesis deduced previously from binding constants obtained with analogous estriol derivatives and the same antiserum.

The N-terminal amino-acid sequence of human placental sterylsulfatase

The N-terminus of the recently isolated sterylsulfatase of human placental cellular membranes was sequenced. According to our results, the enzyme preparation proved to be homogeneous at least with respect to this part of the polypeptide chain; the n-terminal sequence of the sulfatase previously proposed by others, however, had to be revised partially.

Human placental glutathione transferase: interactions with steroids

Glutathione transferases exhibit both isomerase and transferase activity. The acceptance of steroids as substrates for or inhibitors of these activities was studied using a 350-fold enriched preparation of the enzyme from human placenta. As an isomerase, the enzyme preparation catalyzed the conversion of pregn-5-ene-3,20-dione (Km 0.03 mmol/l) and androst-5-ene-3,17-dione (Km 0.05 mmol/l) to the respective 4-ene-3-oxosteroids (specific activity 0.8 U/mg protein). This isomerase activity strictly depended on the presence of glutathione (Km 0.04 mmol/l). As a transferase, the enzyme preparation catalyzed the conjugation of glutathione (Km 0.5 mmol/l) with 1-chloro-2,4-dinitrobenzene (Km 1.0 mmol/l) (specific activity 100 U/mg protein). This transferase activity was inhibited by all phenolic (KI values 0.2-1.5 mmol/l) and some of the neutral steroids (KI values 1.4-3.5 mmol/l) tested. Phenolic steroids inhibited the enzyme activity competitively to 1-chloro-2,4-dinitrobenzene and non-competitively to both substrates. The results indicate that steroids can interact with the placental glutathione transferase in vitro both as substrates and as inhibitors. Since, however, the observed Km and KI values of the steroids are far above the values of their concentrations in the placenta, these interactions are of only minor physiological relevance.

Human placental steryl-sulfatase. Enzyme purification, production of antisera, and immunoblotting reactions with normal and sulfatase-deficient placentas

The steryl-sulfatase of normal human placental microsomes was solubilized and enriched about 350-fold. Chromatography on Sepharose 6B of the purified enzyme preparation revealed a single protein peak which eluted according to an apparent molecular mass of 270 +/- 30 kDa; when electrophorized on sodium dodecyl sulfate polyacrylamide gel the sulfatase migrated according to a molecular mass of 64 +/- 4 kDa. Estrogensulfatase activity was co-purified with the steryl-sulfatase activity; obviously, both activities belong to the same enzyme species. The purified sulfatase was injected into three rabbits. Antisera produced by the rabbits yielded a single sharp immunoprecipitation line in Ouchterlony double diffusion experiments when tested with the isolated sulfatase or with a solubilized microsomal fraction of normal placentas. The activity of sulfatase preparations incubated with antiserum was precipitated by addition of polyethylene glycol followed by centrifugation; none of the antibodies reacting with the sulfatase therefore appeared to interfere with its enzymatic activity. Using these antisera, steryl-sulfatase protein could be detected by immunoblotting analysis in solubilized microsomal fractions of normal placentas but not in solubilized microsomal fractions of three steryl-sulfatase activity-deficient placentas. This finding argues in favour of human placental steryl-sulfatase deficiency being due to extremely diminished or absent enzyme protein in the placenta.

Human placental steroid-sulfatase solubilized with a cholic-acid derivative: molecular mass, kinetic properties and susceptibility to glycosidases

Human placental steroid-sulfatase was extracted nearly quantitatively from microsomes as well as from acetone dry powder of placenta homogenates using CHAPS as detergent. The solubilized enzyme was enriched 10-fold by ammonium sulfate precipitation and gel chromatography. The sulfatase extracted from both microsomes and acetone dry powder eluted as a single fraction on Sepharose 6B, but with different apparent molecular masses (390 and 270 kDa, respectively). Kinetic experiments with the sulfate esters of dehydroepiandrosterone, 16 alpha-hydroxydehydroepiandrosterone, estrone, and estriol as substrates or inhibitors indicated that the solubilized sulfatase was fully active. Both the particulate and the extracted enzyme showed higher affinities for the 16-unsubstituted than for the 16 alpha-hydroxylated substrates. Whereas a competitive inhibition was observed in mixed substrate incubations with dehydroepiandrosterone sulfate/16 alpha-hydroxydehydroepiandrosterone sulfate and estrone sulfate/estriol sulfate, diverse patterns of inhibition were obtained with dehydroepiandrosterone sulfate/estrone sulfate, depending on the sulfatase preparation used. However, evidence for the distinct nature of the steroid-sulfatase and the estrogen-sulfatase was not obtained. The membrane-bound, but not the solubilized enzyme was to a certain degree sensitive to lipase and acetone. The solubilized sulfatase strongly bound to ConA-Sepharose. This observation together with the elution by alpha-methyl mannoside were indicative of the presence of carbohydrates on the sulfatase. Since its enzymatic activity was markedly decreased by the effects of alpha-mannosidase and N-acetylglucosaminidase, a possible involvement of the carbohydrate moiety in the catalytic activity of the sulfatase might be considered.

[Determination of total oestrogens in pregnancy urine: rapid and simple extraction of oestrogens by Sep-Pak C18 cartridges]

The new method of solid-liquid extraction of oestrogens from pregnancy urine with Sep-Pak C18 cartridges was compared to the approved method of extraction with Amberlite XAD-2 columns. At about equal costs the extraction by Sep-Pak cartridges turned out to be more economical with respect to time and work. The yield was higher by about 35% and the precision was slightly improved. On account of these results the hitherto applied method of extraction by Amberlite XAD-2 was replaced by the Sep-Pak C18 method within our routine analysis for oestrogen determination in pregnancy monitoring. The method proved to be good over one year; therefore it can be recommended generally.

Human placental steroid-sulfatase. Kinetics of the in-vitro hydrolysis of dehydroepiandrosterone 3-sulfate and of 16 alpha-hydroxydehydroepiandrosterone 3-sulfate

35S-labeled sulfate esters of dehydroepiandrosterone and 16 alpha-hydroxydehydroepiandrosterone were synthesized and used as substrates for the in vitro kinetic assay of human placental steroid-sulfatase. Both steroid sulfates were hydrolysed by placenta homogenates and microsomal fractions with V values comparable to each other. The Km value of the 16 alpha-hydroxy compound, however, was found to be about tenfold higher than that of dehydroepiandrosterone sulfate. Both sulfate esters competitively inhibited each other's hydrolysis. The results suggest that dehydroepiandrosterone sulfate, as compared to its 16 alpha-hydroxy derivative, is the preferred substrate of the sulfatase. As far as conclusions can be drawn from experiments in vitro, this finding excludes the possibility that the preponderance of placental estriol production over that of estradiol and estrone in human late pregnancy is due to a preferential binding and cleavage of the estriol precursor 16 alpha-hydroxydehydroepiandrosterone sulfate by the placental steroid-sulfatase.