Rapid determination of creatinine in serum and urine by ion-pair high-performance liquid chromatography.

We report a simple and reliable high performance liquid chromatography method for measuring creatinine in serum and urine. The chromatographic run is performed on a C(18) column after protein precipitation with acetone and addition of cimetidine as an internal standard. The separation is carried out in 20 min at a flow rate of 0.8 ml/min, with a mobile phase consisting of 100 mmol/l sodium dihydrogen phosphate solution, containing 30 mmol/l sodium lauryl sulfate pH 3.0 and acetonitrile (60:36, v/v). The absorbance is monitored at 200 nm. The relationship between creatinine concentration and the creatinine/internal standard peak area is linear up to 1,088 micromol/l. Within-run precision measured at three different creatinine concentrations ranges from 0.89% to 2.34% in serum and from 0.34% to 1.10% in urine. Between-run precision varies from 1.68% to 3.17% in serum and from 1.58% to 1.85% in urine over a wide range of concentrations. Analytical recovery is between 98.71% and 101.25% in serum and between 98.96% and 100.27% in urine. The detection limit is 3.24 micromol/l for a signal-to-noise ratio of 3. The method shows a good linearity with the reference isotope dilution gas chromatography-mass spectrometry procedure (r=0.999), without interferences, even in the presence of high bilirubin concentrations.

The protective effects of L-arginine after liver ischaemia/reperfusion injury in a pig model.

Hepatic ischaemia/reperfusion is characterized by circulatory and metabolic derangement, liver dysfunction, and tissue damage. To evaluate the role of L-arginine, a substrate of nitric oxide, in ischaemia/reperfusion injury, total liver ischaemia was induced for 120 min in 22 Landrace x Large White female pigs, which were randomly assigned to a treatment group (10 animals) or a control group (12 animals). An L-arginine bolus (540 mg/kg i.v.) was administered to the treatment group 1 h before clamping the hepatic hilum, at clamping, at reperfusion, and at 1 and 2 h after reperfusion. The control animals received normal saline and an i.v. infusion. Liver function tests and analysis of serum, erythrocyte, and tissue malondialdehyde contents were performed at commencement of laparotomy, before reperfusion, and at 30 min and 7 days after reperfusion. Liver biopsies were taken at laparotomy, at 30 min, and at 7 days after reperfusion for histological and ultrastructural examination. Assessment of apoptosis included in situ end-labelling analysis and DNA gel electrophoresis. Survival at 7 days was better in the treated animals than in the controls (9/10 vs. 7/12). Tissue malondialdehyde content, aspartate aminotransferase, and lactate dehydrogenase levels were lower in the treatment group, in which morphological changes were significantly less evident than in the controls 30 min after reperfusion. At 7 days, differences between the groups with respect to cell integrity were apparent only on ultrastructural analysis. Glycogen content, 7 days after reperfusion, was higher in the treatment group than in the controls: 70.25 per cent vs. 21.66 per cent positive hepatocytes (score 3 vs. score 1). Multiparametric analysis showed fewer apoptotic cells in the treatment group at all times. Our data show that the administration of L-arginine reduces damage to liver tissue after ischaemia/reperfusion injury in a pig model. This may be explained not only by the known vasodilator, anti-aggregation, and superoxide inactivation effects of increased nitric oxide release, but possibly also by some other action of L-arginine, such as its influence on cellular metabolism.

Urinary gonadotropin peptide: collection of specimens and cutoff levels.

A low-molecular-weight form of human chorionic gonadotropin (hCG), urinary gonadotropin peptide (UGP), has been isolated from the urine of pregnant women and of patients with cancer, mainly of gynecological origin. The clinical value of UGP measurement in gynecological diseases is under investigation but a preliminary study is necessary in order to ascertain whether there is a circadian rhythm in UGP production, to clarify the best way to express the results, and to establish the cutoff and decisional values. In our work we demonstrated a significant correlation between the UGP output and the UGP excretion normalized for urinary creatinine. A very significant agreement was even found in 24-hr urine collections and UGP concentration of a single morning specimen from the same patients. No evident circadian rhythm was found, although some patients presented morning levels of UGP higher than in other collections. UGP postmenopausal levels were higher than premenopausal. The cutoff level, adopting the 95.0 percentile, was 200 pmol/mol creatinine.

Working with psychotic patients.

I have discussed a model of the psyche comprising two different modes of thinking, one non-psychotic and the other psychotic. I have related these modes of thinking to our modern myth of Jekyll and Hyde, the study of which could in my opinion give us some insight into their nature. In my view a non-psychotic state of mind belongs to a person who has a history, with particular parents, a particular development, particular conflicts, and operates in the depressive position. A psychotic state of mind belongs to a person who lives in a still and timeless present, with no origin, no development and no conflict, and operates in the paranoid-schizoid position. On the basis of this model I have subsequently described the life history of a psychotic patient and an analytic session in detail, showing how psychotic and non-psychotic states alternate and interact with each other within the same individual and between patient and therapist. The use of my countertransference, moving from a concrete to a symbolic position, has enabled me to make an interpretation. The result of this interpretation has been double, leading to a negative therapeutic reaction. An upsurge of psychotic fury was followed by increased patient/therapist communication, with a small movement from the paranoid-schizoid to the depressive position.

[Diagnostic value of 5'nucleotidase in primary and secondary neoplasms of the liver]. / Valore diagnostico della 5'nucleotidasi nelle neoplasie primitive e secondarie del fegato.

64 patients with various malignant neoplasms (6 primary and 18 secondary liver cancers, 40 tumors without evidence of hepatic involvement) entered a comparative study measuring serum levels of 5'nucleotidase, AFP, TPA, CEA, CA 19-9. In primary liver cancer, 5'nucleotidase true positive rate was 100% (vs 67% of AFP, TPA, CA 19-9 and 33% of CEA); in secondary liver tumors it was 67% (vs 11% of AFP, 44% of CEA, 55% of CA 19-9 100% of TPA). Diagnostic sensitivity was 75% and specificity 90.5%.