Elevation of serum N-terminal pro-brain natriuretic peptide after exercise is an index of myocardial damage or a cytoprotective reflection?

AIM: Recent investigations have suggested the occurrence of transient cardiac dysfunction and reversible myocardial injury in healthy individuals after heavy exercise. Our purpose was to examine if the release of N-terminal pro-brain natriuretic peptide (NT-proBNP) after intense exercise in obviously healthy participants may have cytoprotective and growth-regulating effects or may result from myocardial dysfunction/damage with changes in cTnT as a marker for myocardial cell necrosis during exercise. METHODS: In 43 highly-trained male athletes <35 years old, who were examined immediately after exercising as well as 2 days later, 21 age-matched male patients classified as stage-B according to ACC/AHA guidelines and 35 healthy age-matched males, we evaluated NT-proBNP and 3rd generation's cTnT by electrochemiluminescence immunoassay. All participants underwent a detailed cardiac protocol including echocardiography and electrocardiogram (ECG). RESULTS: In athletes, cTnT consistently remained <0.01 mg/L after exercising as well as after 2 days. NTproBNP immediately after exercising was 58.27+/-19.48 ng/L, without reaching pathological levels, decreasing 2 days later to 22.93+/-10.22 ng/L. Our patients maintained high levels of NTproBNP, as much as a six-fold increase with reference to the levels of our study's control group and with cTnT <0.01 mg/L. In the control group, cTnT and NTproBNP levels were statistically similar with those of the athletes 2 days after exercising. NT-proBNP as a biological marker can reliably discriminate pathological from physiological cardiac hypertrophy. CONCLUSION: A normal plasma concentration of NT-proBNP in consecutive routine check-up, before and after exercise, could minimize the possibility of cardiac dysfunction, whereas persistent elevated plasma concentrations warrant further cardiological evaluation.

Bisalbuminemia from a clinical chemist's viewpoint: a case report and review of the recent literature.

Bisalbuminemia is a rare inherent or acquired abnormality characterized by the occurrence of 2 distinct albumin bands or a single widened albumin band, after electrophoretic screening of blood proteins. Despite the fact that the presence of 2 albumin bands in electrophoresis, representing normal and variant protein, is observed with a frequency of 0.00030.0010 in the average population, its role in various pathological states has not yet been clearly defined. Until now, the only disorders which have been directly linked with the presence of congenital bisalbuminemia are familial dysalbuminemic hyperthyroxinemia (Arg218AEHis and Arg218AE Pro mutations) and hypertriiodothyroninemia (Leu66AEPro mutation), while acquired types of bisalbuminemia have been reported after an overdose of beta-lactam antibiotics and as a consequence of severe pancreatitis. We present a case of bisalbuminemia in an adult man who was referred to our laboratory with a prolonged history of recurrent abdominal pain and review the recent literature in order to better familiarize clinicians as well as laboratory personnel with this entity. The biochemical parameters assessed did not show any alteration which could correlate the protein disorder with any distinct pathology.

Correlation of MDR 1 expression and CA 125 in ovarian cancer.

BACKGROUND: The serum CA 125 marker is elevated in 80% of patients with ovarian adenocarcinoma. MDR 1 gene expression has been identified in a variety of tumor types and its expression has been correlated with multidrug resistance. Whether there is a correlation between CA 125 levels and MDR 1 expression has not been sufficiently investigated. Therefore, the aim of this study was to examine whether an association between serum CA 125 levels and MDR 1 expression exists. PATIENTS AND METHODS: Serum CA 125 levels were measured during the diagnosis of ovarian cancer. Fresh tumor specimens or ascitic fluid samples were studied for MDR 1 expression by the polymerase chain reaction method (PCR). RESULTS: Forty patients with ovarian cancer were studied, 34 (85%) of whom had elevated CA 125. Twenty-eight out of the 40 patients were tested for MDR 1 expression; 20 expressed the gene and 8 did not. The median level of CA 125 in specimens expressing the MDR1 gene was 327, and in specimens that did not it was 376. There was no correlation between the CA 125 levels and MDR 1 expression (p = 0.484). CONCLUSION: There does not seem to be an association between CA 125 levels and expression of the MDR1 gene in patients with ovarian cancer.

Small doses of LH activity are needed early in ovarian stimulation for better quality oocytes in IVF-ET.

OBJECTIVE: To examine whether exogenous LH administration has a beneficial effect on the quality of oocytes, fertilization potential, as well as pregnancy rate in IVF-ET cycles. A randomized trial comparing r-FSH versus r-FSH and LH was employed. STUDY DESIGN: Forty-six infertile couples entering IVF-ET for the first time (either tubal or male factor) were divided after prospective randomization into two groups. In both groups the long protocol with GnRH-analogs was used. In group A, ovarian stimulation started with r-FSH (200 IU/day) for the first four days. In group B, the stimulation protocol started with one amp hMG (75 IU FSH + 75 IU LH activity) daily for four days, with simultaneous administration of r-FSH (150 IU/day). The outcome was compared. RESULTS: Statistical difference was observed in the number of mature oocytes, the number of fertilized oocytes as well as the number of transferable embryos. In all cases, results were statistically significantly better (p < 0.05) in group B. Clinical pregnancy rate, finally, was similar in the two groups. CONCLUSION: The relatively small sample size does not allow a definitive conclusion for the important role of LH during early oocyte maturation. Our results, however, indicate a beneficial effect when small doses of LH are used for ovarian stimulation in IVF-ET cycles. This effect may be more important in cases in which few embryos are available for transfer.

Lipid levels in high density lipoprotein subfractions in smokers with peripheral vascular disease.

No significant difference in HDL cholesterol was found between smokers with PVD and corresponding controls. The ratio of HDL cholesterol to the sum of (VLDL + LDL) cholesterol was reduced in patients with PVD. Patients with PVD had significantly highly serum triglyceride levels. A slightly significant difference could be demonstrated for serum cholesterol and serum phospholipids concentrations in smoking patients with PVD.

In vitro activity of polyunsaturated fatty acids on Pseudomonas aeruginosa: relationship to lipid peroxidation.

Based on previous findings that gamma-linolenic acid (GLA) inhibits Escherichia coli growth and provokes the induction of strains resistant to aminoglycosides, 19 Pseudomonas aeruginosa strains were exposed in vitro over time to GLA, to arachidonic acid (AA) and to their combination in the presence or absence of vitamin E. All acids were used at a 300 microg/ml concentration, whereas vitamin E was added as an antioxidant. Lipid peroxidation was evaluated by the thiobarbiturate assay measuring malonodialdehyde (MDA) production. It was found that GLA or AA killed 5-10% of strains at 24 h of growth, whereas when applied in combination their effect involved 100% of strains at 24 h and was limited to 68% of strains in the presence of vitamin E (P< 0.01). MDA production was time-dependent and it was restrained by vitamin E (P < 0.01). Post acid exposure, 27% to 37% of the survived strains became resistant to diverse antimicrobial agents and mainly to ticarcillin, to ceftazidime and to amikacin; no strain developed resistance in the presence of vitamin E. It is concluded that GLA and AA interact bactericidally on P. aeruginosa isolates, inducing the development of strains resistant to beta-lactams and to aminoglycosides; their action might be mediated through their peroxides. Further research is necessary to establish the clinical application of these in vitro findings.

Rapid alterations of serum oxidant and antioxidant status with the intravenous administration of n-6 polyunsaturated fatty acids.

In an attempt to achieve the safe intravenous administration of two n-6 polyunsaturated fatty acids (PUFAs), gamma-linolenic acid (GLA) and arachidonic acid (AA), and to study the subsequent changes on the total oxidant and antioxidant status, various steadily increasing doses of each acid were injected intravenously at different infusion times in 28 male rabbits. Blood samples were collected at 15-min time intervals by the hepatic veins and from the carotid artery; oxidant status was determined by the thiobarbiturate assay and total antioxidant status (TAS) was assessed by a colorimetric assay. Both n-6 PUFAs were administered with safety at a dose of 25 mg/kg within 10 min accompanied by an increase of malonodialdehyde concentrations in the hepatic veins and in the carotid artery 30-45 min, respectively, after the end of the infusion of GLA and/or AA. Similar changes did not occur in red cell membranes after the infusion of AA. TAS presented reciprocal changes to malonodialdehyde production; the main consumption of TAS was observed in all samples 30-60 min after the end of the infusion of n-6 PUFAs. The above-mentioned rapid alterations occurring in both serum oxidant and antioxidant status after GLA might have a future clinical therapeutic significance in conditions like cancer and disseminated infectious diseases.

In vitro influence of polyunsaturated fatty acids on nosocomial Pseudomonas aeruginosa: a preliminary report.

Recent evidence derived from a mouse infection model implies an 'anti-infective' role of polyunsaturated fatty acids (PUFAs) which could not be attributed to an alteration of eicosanoid or cytokine biosynthesis provoked by them. In order to investigate that role, seven Pseudomonas aeruginosa nosocomial pathogens were in vitro exposed to 200 and 300 mug/ml of two PUFAs, arachidonic acid (AA) and gamma-linolenic acid (GLA), by performing 43 time-kill curves. Both PUFAs were found to inhibit P. aeruginosa growth as compared to their controls, an effect maximized at 5 h of incubation and minimized at 24 h. The strains that survived after the 24 h AA and GLA exposure were removed from the culture medium with added AA or GLA; half of these strains acquired enormously higher MIC and MBC values to aminoglycosides compared to their relevant controls. The possible mechanism of action of AA and GLA on P. aeruginosa and the clinical relevance of the presented findings is a matter of further research.

Level of plasma fibronectin in patients with peripheral vascular disease.

Plasma concentration of fibronectin, a recently characterized high molecular mass glycoprotein, was determined in patients with peripheral vascular disease. The plasma fibronectin concentration was lower in patients with peripheral obstructive arterial disease as well as in patients with venous disease, than in corresponding healthy controls. Patients with venous disease had significantly lower levels of plasma fibronectin than patients with peripheral obstructive arterial disease. The patients with peripheral arterial disease were divided into two groups, one having diabetes and another not having diabetes respectively. Between these two groups there was no significant difference in plasma fibronectin concentration.

Human neutral brush border endopeptidase EC 3.4.24.11 in urine, its isolation, characterisation and activity in renal diseases.

Human neutral brush border endopeptidase (NEP) was purified from the urine of patients suffering from acute toxic tubulointerstitial nephropathy. An enzyme preparation with specific activity of 102 Ug(-1) protein was obtained. The urinary activities of neutral endopeptidase and alanine aminopeptidase were measured in patients with renal disease and in 30 control patients, resulting in a reference range from 0.1 to 0.7 Ug(-1) creatinine and 1.4-14.1 Ug(-1) creatinine, respectively. Urine enzyme activities were highest in patients with acute tubulotoxic renal diseases. Neutral endopeptidase and alanine aminopeptidase activities were found to be 6.5- and 10-fold higher than the upper value of the reference range, respectively. Smaller increases in the rate of excretion of these enzymes (2.5- and 3.5-fold), respectively, were observed in patients suffering from acute tubular insufficiency and even lower increases, 2- and 1.5-fold, respectively, were observed in patients with chronic renal diseases. In diabetics and kidney transplant patients the enzyme excretion rates were within the reference range. Assay of both transmembrane metalloproteinases in urine may prove valuable in serving as markers for renal toxicity. Together with beta-NAG these enzymes could be employed as differentiation markers between acute and chronic tubular insufficiency.

Changes of HDL-lipid composition as related to delta 9-THC action.

An attempt was made to investigate the possible action of delta 9-THC on HDL-Lipid composition. Significant changes were observed in the serum total lipids, triglycerides and HDL subfractions after hashish smoking. The results are discussed in relation to the possible alterations of some enzymatic mechanisms regulating lipid metabolism in hashish users.

Determination of proteolytic activity using L-[4,5-3H]leucine-labelled globin as a substrate.

A method is described for the assay of proteolytic activity, based on the digestion of L-[4,5-3H]leucine globin. L-[4,5-3H]Leucine was incorporated into the substrate at the stage of haemoglobin biosynthesis, using rabbit erythrocytes. Assay methods for proteolytic enzymes have been based on the digestion of haemoglobin, serum albumin or casein, and the determination of the trichloroacetic acid-soluble products [1,2]. More sensitive methods have been developed by using haemoglobin labelled with a fluorescent [3-5] or radioactive marker [6,7]. These methods avoid the errors which beset the Anson procedure, such as interference by impurities (purines at 280 nm and reducing compounds at 700 nm) [8]. However, methods using labelled proteins as a substrate present a number of problems, the most troublesome of which are the high blank values and the use of non-physiological substrates when chemically modified proteins are employed. In the present communication a simple and sensitive method for the assay of proteolytic enzyme activity is described. This is based on the digestion of L-[4,5-3H]leucine globin by proteolytic enzymes and radioactivity measurement of the trichloroacetic acid soluble cleavage products.

Follicular fluid inhibin levels in relation to age in patients in an in vitro fertilization and embryo transfer programme.

Inhibin (INH), oestradiol (E2) and progesterone (P) were measured in the follicular fluid (FF) of 22 patients 28-38 years old (Group A) and 11 patients 43-47 years old (Group B) who had received gonadotrophin stimulation in an in vitro fertilization and embryo transfer (IVF-ET) programme. The results indicated that INH, E2 and P levels were significantly lower and the E2/P ratio was higher in FF of Group B patients (older women) compared to those of Group A. There were six single pregnancies among patients of Group A. No difference was observed in follicular fluid INH, E2 and P levels as well as in E2/P ratio between pregnant and non-pregnant patients of Group A (Group A1 and Group A2, respectively). A positive correlation was found between FF concentrations of E2 and P, E2 and INH and P and INH in the three Groups and a negative one between INH and the E2/P ratio in Group B. It seems likely that ovarian INH and E2 production are controlled by different mechanisms and that INH response to ovarian hyperstimulation is altered by advancing age.

A comparative study of the effect of ovarian stimulation protocols with different gonadotropin preparations on the biological and clinical parameters of the outcome of intracytoplasmic sperm injection.

Intracytoplasmic sperm injection (ICSI) is widely employed today in cases of severe male factor infertility. This technique requires denuding the oocytes from the surrounding granulosa cells prior to sperm injection. One can thus assess oocyte maturity more accurately and can study the effects of various ovarian stimulation protocols on egg maturation and the rest of the parameters of the outcome of ICSI. The aim of the present study was to compare the outcome of ovarian stimulation using human menopausal gonadotropin (hMG) with that achieved by using highly purified follicle stimulating hormone (pFSH). The biological and clinical parameters of the outcome of ICSI in 99 subfertile couples were studied. Group A consisted of 46 patients to whom hMG was administered and Group B consisted of 53 patients to whom pFSH was employed for ovarian stimulation. The fertilization rate was significantly higher in the pFSH group but all other factors were similar, including the percentage of mature oocytes and pregnancy rate. The latter does not seem to be affected by the gonadotropin preparation employed for ovarian stimulation. This is very helpful for the physician to know since a gonadotropin with a lower cost can be employed and, in addition, shortage of some preparations of gonadotropins occurs frequently.

Adipocyte factors, high-sensitive C-reactive protein levels and lipoxidative stress products in overweight postmenopausal women with normal and impaired OGTT.

OBJECTIVE: In obese postmenopausal women we assessed leptin and adiponectin, high-sensitive C-reactive protein (hsCRP), serum lipids and lipoxidative stress products: oxidized LDL (oxLDL) and malondialdehyde (MDA), in relation to impaired glucose tolerance (IGT). METHODS: Thirty-eight overweight/obese postmenopausal women were included in the study. Eighteen with normal glucose metabolism (NGT) and twenty with IGT, as it is diagnosed by OGTT. Serum leptin, adiponectin, hsCRP and MDA were measured at time 0 and 120 min of OGTT while total-cholesterol, LDL, HDL, triglycerides, oxLDL and anti-oxLDL autoantibodies at time 0. Insulin resistance (HOMA)/sensitivity (QUICKI) indexes were estimated. RESULTS: In subjects with NGT, hsCRP was positively correlated with fasting leptin and HOMA, while in subjects with IGT negatively with QUICKI. In both groups, hsCRP was positively correlated with fasting insulin, body mass index and waist circumference. Fasting adiponectin was positively associated with HDL in both groups and negatively with triglycerides in subjects with NGT as well as with serum glucose levels at time 120 min of OGTT in subjects with IGT. No association was observed between oxLDL and adipokines. A significant positive association was found between oxLDL and HOMA in subjects with IGT. During OGTT there was a significant increase of leptin and MDA levels in both groups. CONCLUSIONS: A relationship exists between obesity, insulin and sub-clinical inflammation. Leptin and lipid peroxidation are linked to hyperglycaemic state while oxLDL might be considered as a predictor of insulin resistance. Adiponectin could exert its antiatherogenic effect through HDL independently of the presence of IGT.

Circulating oxidized LDL levels, current smoking and obesity in postmenopausal women.

OBJECTIVE: The aim of the present study was to estimate circulating oxidized low-density lipoprotein (oxLDL) levels in postmenopausal women and evaluate their association with obesity and smoking status. DESIGN AND METHODS: The study included 135 postmenopausal women aged 52-75 years. Forty of them were overweight (BMI 32.4+/-6.4) and non-smokers (Group A), 40 non-overweight (BMI 22.6+/-1.8) and smokers (Group B) and 55 non-overweight (BMI 23.5+/-1.4) and non-smokers (Group C). oxLDL and antibodies against them (anti-oxLDL) were measured using ELISA. Serum total cholesterol, LDL, HDL and triglycerides were measured in an automated analyzer. RESULTS: Total cholesterol, LDL, HDL and oxLDL serum levels were significantly elevated in Group A as compared to Group B or C, as well as oxLDL in Group B in comparison to Group C (p<0.001). Triglycerides and anti-oxLDL were increased in Group A in comparison to Group C (p=0.043 and 0.023). Total cholesterol, LDL, triglycerides and anti-oxLDL did not differ between Groups B and C, while HDL was decreased in Group B as compared to Group C (p<0.001). A significant positive correlation was found between oxLDL and LDL in Group A (r=0.53, p<0.001) as well as in Group C (r=0.955, p

Postnatal changes of cathepsin D activity in rat liver and brain.

Total and specific activity of cathepsin D (EC. 3.4.23.5) were measured in rat liver and brain from 1 to 98 days of age. The activity of cathepsin D in the liver of adult and newborn rats was the same while in the rat brain it was higher in adult than in newborn rats. In the liver maximum specific activity of cathepsin D occurred on the 10th postnatal day and minimum on the fourth day of age. In the brain maximum specific activity of the enzyme occurred on the 14th postnatal day. Total activity of cathepsin D increased after birth in rat liver and brain. These results are discussed in relation to the functional role of cathepsin D in the rat liver and the brain.