[Application of multivariate analysis to the serum mineral and trace element content on differentiation of healthy subjects]. / Aplicación de análisis multivariado para la diferenciación de individuos sanos según su contenido sérico de minerales.

OBJECTIVE: Serum concentrations of Na, K, Ca, Mg, Fe, Cu, Zn, Se, Mn and P were determined in apparently health individuals representing of the population of the Canary Islands. Multivariate analysis was applied on the data matrix in order to differentiate the individuals according several criteria such as gender, age, island and province of residence, smoking and drinking habits and physical exercise. SUBJECTS AND METHODS: 395 serum samples (187 men and 208 women) were analyzed mean age of 38.4 +/- 20.0 years. Individuals data about age, gender, weight, height, alcohol consumption, smoking habits and physical exercise were recorded using standardized questionnaires. The determination of minerals was carried out by flame emission spectrometry (Na and K) and atomic absorption spectrometry with flame air/acetylene (Ca, Mg, Fe, Cu, Zn), hybride generation (Se) and graphite furnace (Mn). The P was determined by a colorimetric method. RESULTS: The sex and age of individuals influenced on the serum concentrations of some minerals, Cu and Fe, and P and Se, respectively. The island of residence influenced the mean concentrations of the most the minerals analysed. The smoking and drinking habits do not seem to influence the mean contents of the minerals in an important manner. Physical exercise had significant influence on the P, Cu and Mn concentrations in serum. The water for consumption influenced on the serum concentrations of the electrolytes and Ca and Mg, but it did not affect the concentrations of the trace elements. Applying discriminant analysis the individuals lower 18 years were reasonably well differentiated (89% of the individuals correctly classified) from the rest of individuals. A tendency for differentiation of individuals according to the island of residence was also observed. CONCLUSIONS: A low differentiation of the individuals according to the sex, province or island or residence and habits or life style was observed after application of multivariate analysis techniques. However, the adults were reasonably differentiated from the children and adolescent, and the inhabitants of Lanzarote and La Palma tend to separate from the rest of the individuals of their province.

[Concentrations of Na, K, Ca, and P in serum from a representative sample of the Canary Islands population]. / Concentraciones de Na, K, Ca y P en sueros de una muestra representativa de la población canaria.

As part of the nutritional survey of the Canary Islands (ENCA-1998), the concentrations in serum of Na, K, Ca and P were determined in 395 individuals representing the population of the Canary Islands. The concentrations were found to be within the reference intervals described for the healthy population. Differences were observed in the mean concentrations depending on the island of residence. Thus, individuals on the island of Tenerife showed higher levels of natremia and calcaemia (p < 0.05) than those on the other islands. The islanders of La Palma have the highest (p < 0.05) and lowest (p < 0.05) concentrations of K and Ca, respectively, whereas those living on the easternmost islands have the highest levels of phosphataemia. No differences were detected in the mineral levels by sex. Phosphataemia levels fall (p < 0.05) in line with socio-economic levels. Females under the age of 18 present lower levels of natremia (p < 0.05) than others while males over the age of 35 present higher levels of kalaemia (p < 0.05). No important age-related differences were found in calcaemia and individuals under the age of 18 had lower levels of phosphataemia (p < 0.05) than the remainder. Highly significant relationships were found between Na and K and between Ca and P, thus confirming existing physiological relationships. Smoking had no effect on the serum levels of the elements under study. Those individuals reporting an intake of more than seven beers and seven shots of spirit per week presented lower levels of calcaemia and natremia than the rest (p < 0.05). With wine consumption, an increase in kalaemia and a significant reduction (p < 0.05) in the Na/K ratio were detected. Individuals drinking only tap water had higher levels (p < 0.05) of natraemia and kalaemia, with lower levels (p < 0.05) of calcaemia and the Na/K ratio than those drinking bottled water. The Ca/P ratio was significantly reduced (p < 0.05) with physical exercise.

Serum selenium concentration in a representative sample of the Canarian population.

The concentration of serum selenium in 395 individuals (187 males + 218 females) living in the Canary Islands, Spain was determined by hydride generation atomic absorption spectrometry. The mean selenium concentration was 74.7 +/- 25.2 microg/l ranging between 7.86 and 182.3 microg/l. Twenty-two adults (7.2% of the total) had serum selenium concentrations under 45 microg/l. It is widely accepted that below this selenium serum concentration (45 microg/l) there is an increased risk of cardiovascular disease and cancer. Our results fall within data recently published in other Spanish and European regions and are much lower than data observed in USA or seleniferous regions. The estimated Se intakes of our population were lower than the Recommended Dietary Allowances for American people. Individuals from Lanzarote had a mean Se concentration significantly higher than individuals from the other islands. This could be attributed to differences in Se content of soil and/or differences in dietary habits of the populations. Serum selenium concentration did not vary with the sex of the subjects. Individuals younger than 14 years old had a serum selenium concentration significantly lower than the rest of the individuals. No relationship with socio-economic status, educational level, smoking habits, physical exercise or beer consumption was found. However, individuals who consume wine more than three times a week showed higher selenium concentrations than individuals with lower consumption. Also, individuals with consumption above seven units of spirit drinks a week had the highest mean selenium concentration.

Regulation by ceramide of epidermal growth factor signal transduction and mitogenesis in cell lines overexpressing the growth factor receptor.

Ceramide has emerged as a pleiotropic signal mediator of cellular responses including differentiation, proliferation, cell cycle arrest and apoptosis. In the present study we evaluated the effect of cell permeant ceramide analogues on ligand-induced tyrosine phosphorylation of the EGF receptor (EGFR), phospholipase Cy (PLCgamma) activity and cell proliferation. Treatment with N-acetylsphingosine (C2-cer) and N-hexanoylceramide (C6-cer) prevented EGF-induced tyrosine trans-phosphorylation of the receptor in two different cell lines overexpressing the human EGFR (A431 and EGF-T17 cells). In contrast, treatment of A431 and EGFR-T17 cells with C2-cer or C6-cer did not affect the ligand binding capacity of the receptor, an effect that was however observed after TPA-induced activation of PKC. In addition EGF-stimulated PLCgamma activity was transiently decreased in A431 cells treated with C6-cer and only a modest, albeit significant reduction on ligand-induced 3H-InsP3 generation was observed in EGFR-T17 cells pretreated with ceramide. We also examined the effect of C2-cer on serum (A431)- or EGF (EGFR-T 17)-induced cell proliferation. Treatment of EGFR-TI7 cells with C2-cer (0.1-10 microM) did not affect cell viability, but prevented EGF-induced 3H-thymidine incorporation in a dose-dependent manner. In contrast, 3H-thymidine incorporation in serum-stimulated A431 cells decreased only at the higher doses of C2-cer used (1-10 microM), being this effect accompanied by a slight, albeit significant (20-25%), reduction in cell viability.

Isolation of (S)-(+)-naproxene from Musa acuminata. Inhibitory effect of naproxene and its 7-methoxy isomer on constitutive COX-1 and inducible COX-2.

The isolation and characterisation of (S)-(+)-6-methoxy-alpha-methyl-2-naphthaleneacetic acid, a well known synthetic non-steroidal anti-inflammatory drug (naproxene), from a natural source is described for the first time. We evaluated the ability of naproxene and its 7-methoxy isomer to abrogate constitutive COX-1 and inducible COX-2 activity in human A549 cells. Naproxene inhibited COX-1 (IC50 = 3.42 microM) and COX-2 (IC50 = 1.53 microM), whereas the 7-methoxy isomer had no appreciable effect on COX-1 (IC50 >> 100 microM) but also abrogated the activity of COX-2 enzyme (IC50 = 14.42 microM).

[Biochemical assessment of nutritional status in the Canary Islands population (1998)]. / Evaluación bioquímica del estado nutricional de la población canaria (1998).

UNLABELLED: Nutrition surveys include information about dietary intake and nutritional status utilising clinical, biochemical and anthropometric measurements. OBJECTIVE: To evaluate the nutritional status of the Canary Island population by means of biochemical and haematological indicators METHODOLOGY: A cross-sectional study was realised in a representative subsample aged 6 to 75 years that participated in the Nutritional Survey of the Canary Islands, 1997-98 (ENCA). We determined levels of ferritin and vitamin B12 (enzyme-immunoassay), serum and erythrocytic folic acid (automated ionic catchment), retinol, tocopherol and carotenes (high performance liquid chromatography) and minerals (atomic absorption spectrometry) RESULTS: There were neither sex, age nor socio-economic differences in the reference population sample and the ENCA sample. The participation rate was 48.8%. 25% of the women had deficit levels of ferritin and the prevalence of anaemia in women over 18 years was 2.9%. 13% of the population had low erythrocyte folic acid levels, that increased with age, and 3.4% had low vitamin B12 levels, which, on the contrary, decreased with age, 15% of the population presented a deficit of alpha-tocopherol and 5.2% of retinol, being more frequent in the youngest group, and 56.4% and 41.1% exhibited low levels of beta-carotene and lycopene respectively. Among mineral and trace elements, low levels of manganese drew attention due to its heightened prevalence, and, to a lesser extent, selenium. CONCLUSIONS: In spite of the complexity of its interpretation, this data yields a precise estimation of nutritional status for certain vitamins and minerals in the Canary Island population.

Effect of the protein phosphatase inhibitor okadaic acid on FSH-induced granulosa cell steroidogenesis.

To address a possible role of type 1 and 2A serine/threonine protein phosphatases (PP1 and PP2A) in regulating granulosa cell hormonal responses, we investigated the effects of okadaic acid (OA) on FSH- and cAMP-induced steroidogenesis in these cells. When added alone (0.01-1 nmol/l), the cell-permeant phosphatase inhibitor did not affect progesterone and 3 beta-hydroxysteroid dehydrogenase/delta 5-4 isomerase (3 beta-HSD) enzyme activity, whereas when added with FSH it dose-dependently augmented (minimal effective dose, 0.1 nmol/l) gonadotropin-stimulated steroidogenesis in cultured granulosa cells. A similar stimulatory effect of the toxin was observed in cells cultured for 48 h with the cell-permeant analogue dibutyryl cAMP (1 mmol/l), or when granulosa cells were stimulated with the cAMP-inducing agents cholera toxin (1 microgram/ml), forskolin (15 mumol/l) or 1-methyl-3-isobutyl-xanthine (0.1 mmol/l). The observed effect of OA on FSH-supported granulosa cell steroidogenesis was not a consequence of increased cAMP generation, and time course experiments also revealed that a minimal time period of 12 h was necessary for OA (0.1 and 1 nmol/l) to significantly enhance FSH-induced progesterone and 3 beta-HSD enzyme activity. Since OA also inhibits the dephosphorylation of protein kinase C (PKC) substrates, we also compared the effect of OA and the PKC activator 12-O-tetradecanoylphorbol-13-acetate (TPA) on FSH-induced granulosa cell steroidogenic activity. While activation of the PKC pathway with the tumor promoter TPA (10 nmol/l) inhibited progesterone and cAMP accumulation in FSH-stimulated granulosa cells, treatment with OA augmented steroidogenesis and did not affect gonadotropin-induced cAMP generation. Collectively these results suggest that PP1 and PP2A may be important in regulating the phosphorylation state of proteins implicated in the cAMP-protein kinase A-stimulated steroidogenic activity of these cells.

Induction of guanosine triphosphate-cyclohydrolase by follicle-stimulating hormone enhances interleukin-1 beta-stimulated nitric oxide synthase activity in granulosa cells.

In cultured granulosa cells, interleukin-1 beta (IL-1 beta) induced a time-dependent (16-72 h) and dose-related (0.3-30 ng/ml) stimulation of nitric oxide (NO) synthase (NOS) activity, as determined by the catalytic conversion of [3H]arginine to [3H]citrulline and NO2- accumulation in the culture medium. Although FSH alone failed to stimulate NOS activity, concomitant treatment with the gonadotropin (200 ng/ ml) or the cell-permeant cAMP analog (Bu)2cAMP (0.5 mM) markedly enhanced IL-1 beta-induced NO generation in cultured granulosa cells. The effect of IL-1 beta on citrulline biosynthesis and NO2- accumulation was abrogated by the NOS inhibitor NG-methyl-L-arginine or the IL-1-receptor antagonist protein. In contrast bacterial endotoxin (lipopolysaccharide), interferon-gamma, or tumor necrosis factor-alpha, which are well known inducers of inducible NOS (iNOS) in a variety of immunocompetent and nonimmunocompetent cell types, failed to increase [3H]citrulline formation or NO2- accumulation in untreated or FSH-stimulated cells. As demonstrated by reverse transcriptase-PCR analysis, IL-1 beta-stimulated NO generation was accompanied by a time-dependent increase in messenger RNA levels for iNOS and GTP-cyclohydrolase (GTPCH), the rate-limiting step for de novo tetrahydrobiopterin (BH4) biosynthesis. Treatment with FSH augmented only GTPCH messenger RNA expression, and a more than additive GTPCH signal was observed when cells were simultaneously challenged with IL-1 beta and FSH. Treatment with the GTPCH inhibitor 2,4-diamino-6-hydroxypyrimidine prevented IL-1 beta-induced NOS activity in untreated or FSH-stimulated cells, and this inhibition was completely reversed by sepiapterin, a substrate for BH4 biosynthesis, via an alternative pterin salvage pathway present in many cell types. As BH4 is an essential cofactor for NOS catalytic activity, these observations strongly suggest that FSH-induced biosynthesis of endogenous BH4 is essential for full iNOS biosynthetic capacity in IL-1 beta-stimulated granulosa cells.

Serum androgen levels after streptozotocin administration in the male rat.

Serum levels of testosterone and dihydrotestosterone were measured in control and diabetic animals 5, 10 and 15 days after streptozotocin administration. The diabetic state produced a marked reduction in serum androgen levels 10 and 15 days after streptozotocin administration. Insulin treatment partially restored the circulating androgen levels when administered to diabetic rats.

The effect of starvation, diabetes or hypophysectomy on the testicular function in rat.

Serum levels of testosterone, in vitro production of testosterone and the activity of testicular delta 5-3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) were measured in normal, starved, streptozotocin diabetic and hypophysectomized rats seven days after initiation of the experiment. Similar impaired testicular functions were found in the starved and diabetic animals. The greatest alteration corresponded to the hypophysectomized group. The 3 beta-HSD activity correlates in all groups with hormone levels or hormone production in vitro. The impaired testicular function in the starved and diabetic groups is discussed.