PPARα-L162V polymorphism is not associated with schizophrenia risk in a Croatian population.

Disturbances of lipid and glucose metabolism have been repeatedly reported in schizophrenia. A functional L162V polymorphism in peroxisome proliferator-activated receptor alpha (PPARα) gene has been extensively investigated in etiology of abnormal lipid and glucose metabolism, yet not in schizophrenia. We determined whether the schizophrenia risk was associated with L162V polymorphism and we examined the impact of L162V variant on age of onset, and data of psychopathology scores. We also hypothesized that plasma glucose and lipid concentrations in patients may be influenced by L162V polymorphism. Genotype and allele frequencies between 203 patients and 191 controls did not differ significantly. Females heterozygous for the PPARα genotype (L162V) manifested significantly lower negative symptom scores, tended toward an earlier onset, and had significantly greater triglyceride levels. The PPARα-L162V polymorphism is not associated with schizophrenia risk in Croatian population, but it impacts clinical expression of the illness and plasma lipid concentrations in female patients.

BanI polymorphism of cytosolic phospholipase A2 gene is associated with age at onset in male patients with schizophrenia and schizoaffective disorder.

The enzymes phospholipases A2 are believed to be involved in the pathology of schizophrenia. We investigated allelic and genotype frequencies of PLA2G4A BanI polymorphism and the rs4375 in PLA2G6A in Croatian schizophrenic patients (n=81) and controls (n=182), using PCR/RFLP. Genotype and allelic frequencies of both loci, alone or in combination did not show significant difference (chi2-test). Allele-wise and genotype-wise meta-analyses of BanI polymorphism in case-control and family-based studies also revealed no significant association with schizophrenia. Multiple logistic regression analyses revealed statistically significant association between several items from PANSS general psychopathology scale and BanI polymorphism in PLA2G4A. BanI polymorphism further showed a significant impact on mean age of the onset of disease in males (betaA1=0.351, P=0.021; Spearman's rA1=0.391, P=0.010) indicating lower mean age at admission in homozygous A2A2 males.

Influence of ionic interactions on the photoinduced birefringence of poly[1-[4-(3-carboxy-4 hydroxyphenylazo) benzene sulfonamido]-1,2-ethanediyl, sodium salt] films.

Electrostatic interactions govern most properties of polyelectrolyte films, as in the photoinduced birefringence of azo-containing polymers. In this paper we report a systematic investigation of optical storage characteristics of cast and layer-by-layer (LbL) films of poly[1 -[4-(3-carboxy-4 hydroxyphenylazo) benzene sulfonamido]-1,2-ethanediyl, sodium salt] (PAZO). Birefringence was photoinduced faster in PAZO cast films prepared at high pHs, with the characteristic writing times decreasing almost linearly with the pH in the range between 4 and 9. This was attributed to an increased free volume for the azochromophores with the enhanced electrostatic repulsion in PAZO charged to a greater extent. In contrast, in LbL films of PAZO alternated with poly(allylamine hydrochloride) (PAH), the electrostatic interactions between the oppositely charged polymers hampered photoisomerization and molecular rearrangement, thus leading to a slower writing kinetics for highly charged

Phase transition in poly(vinylidene fluoride) investigated with micro-Raman spectroscopy.

The phase transition from the non-polar alpha-phase to the polar beta-phase of poly(vinylidene fluoride) (PVDF) has been investigated using micro-Raman spectroscopy, which is advantageous because it is a nondestructive technique. Films of alpha-PVDF were subjected to stretching under controlled rates at 80 degrees C, while the transition to beta-PVDF was monitored by the decrease in the Raman band at 794 cm(-1) characteristic of the alpha-phase, along with the concomitant increase in the 839 cm(-1) band characteristic of the beta-phase. The alpha-->beta transition in our PVDF samples could be achieved even for the sample stretched to twice (2x-stretched) the initial length and it did not depend on the stretching rate in the range between 2.0 and 7.0 mm/min. These conclusions were corroborated by differential scanning calorimetry (DSC) and X-ray diffraction experiments for PVDF samples processed under the same conditions as in the Raman scattering measurements. Poling with negative corona discharge was found to affect the alpha-PVDF morphology, improving the Raman bands related to this crystalline phase. This effect is minimized for films stretched to higher ratios. Significantly, corona-induced effects could not be observed with the other experimental techniques, i.e., X-ray diffraction and infrared spectroscopy.

Manipulation of anchoring strength in an azo-dye side chain polymer by photoisomerization.

The generation of surface anisotropy by photochemical means has been proposed as an attractive method to align liquid crystals. In this paper, we present an experimental study of the alignment induced on a liquid crystal by a polymer film containing azo-dye groups in the side chain. Optical measurements were performed in nematic liquid crystal cells to determine the azimuthal and zenithal anchoring strengths as a function of the irradiation energy and chromophores concentration. It was observed that the director tends to align perpendicular to the polarization direction of the incident light and the orientation process consists essentially of a rotation of the director in the plane parallel to the boundary surfaces. However, the concentration of azo-dye groups in the polymer film must exceed a minimum value to get a macroscopical effect on the liquid crystal alignment. It is shown that the azimuthal anchoring strength can be varied two orders of magnitude by controlling the irradiation energy and azo-dye concentration.

Effect of olive oil- and corn oil-enriched diets on the tissue mineral content in mice.

The mineral content (zinc, iron, magnesium, and calcium) in the liver, spleen, and thymus of male Balb/C mice was analyzed. Animals were fed, over 21 d, diets enriched with corn oil (FCO diet) or olive oil (FOO diet) (5% addition to standard pellet, w/w). Olive oil with predominant oleic acid (C18:1, n-9) had a quite different composition than corn oil, in which linoleic acid (C18:2, n-6) prevails. The zinc and magnesium tissue concentrations were not changed in either group. The calcium concentration in liver as well as the calcium concentration in spleen increased in mice fed both the FCO and FOO diets. Furthermore, mice fed both the FOO and FCO diets had increased spleen iron concentration. Mice fed the FCO diet had increased thymus calcium concentration compared to controls. The results show the effect of diets with unsaturated, particularly polyunsaturated fatty acids, on the calcium and iron concentration in some organs.

Physico-chemical characteristics of olives and olive oil from two mono-cultivars during various ripening phases.

The aim of this study was to find a correlation between the chemical and physical parameters in the pulp of the olive, in order to identify the optimum period during the 1998 harvesting period. For this reason various parameters have been monitored: the amount of oil in the pulp during the ripening phase obtained by solvent extraction with n-hexane, the acidity, the peroxide value, the composition of fatty acids and the saturated/unsaturated fatty acid ratio, the composition of the unsaponifiable fraction, the antioxidant capacity, the percentage of oil and the puncture test in two local Croatian olive cultivars. The chemical parameters change during the ripening, in order to control the oxidative changes of the cellular homeostasis of the whole lipophilic fraction that needs a stronger safeguard of the double bonds against the oxidative stress. The modification of the physical characteristics, observed with the puncture test, is related to the chemical changes which occur in the olive during the ripening period and the monitoring of these physical and chemical parameters can help to increase nutritional quality (as antioxidant capacity) and allow for an acceptable amount of oil.

Determination of aliphatic alcohols, squalene, alpha-tocopherol and sterols in olive oils: direct method involving gas chromatography of the unsaponifiable fraction following silylation.

In general, analyses for aliphatic alcohols, sterols and tocopherols in vegetable oils are performed separately. A simple and reliable procedure is presented for the quantification of the alkanols, squalene, alpha-tocopherol and sterols in olive oils by a direct method involving gas chromatographic (GC) analysis of the unsaponifiable fraction after silylation. The method eliminates the need for a preliminary thin-layer chromatographic (TLC) fractionation prior to GC. External standard calibration with reference substances was used for the quantification of squalene, alpha-tocopherol and sterols and internal standard calibration for the quantification of aliphatic alcohols. The analyte recovery and the repeatability of the quantitative results were evaluated and were acceptable for routine use.

Tissue zinc dynamics during the immune reaction in mice.

Owing to the importance of zinc for the functioning of the immune system, the role of endogenous Zn, located both in lymphoid and nonlymphoid organs, was investigated during the standard humoral and cellular types of immune response. For this purpose, the dynamics of hepatic, thymic, splenic, and renal Zn content was determined in mice sensitized with (a) sheep red blood cells and (b) semiallogeneic lymphocytes during the local host vs graft reaction (HVGR). The data obtained by ion-coupled plasma spectrometry revealed that the humoral type of immunity is characterized by a significant increase of Zn concentration in the liver and in the thymus. Simultaneously, linear regression analysis showed that the generation of plaque-forming cells in the individual mouse was highly positively correlated with Zn concentration in the liver (r=0.897), and spleen (r=0.833), and negatively with Zn concentration in the thymus (r=-0.624). Similar relationships between the intensity of local immune reaction and tissue Zn levels were found in local HVGR at the fifth day in the liver and spleen (r=0.861 and r=0.695, respectively), at the seventh day in the thymus (r=-0.797), and at the tenth day in the liver (r=-0.859). The data emphasize the necessity of Zn for the development of normal immune response and point to the existence of a Zn-dependent hepato-thymic axis during the humoral and cellular types of immune reactivity.

Determination of standard zinc values in the intact tissues of mice by ICP spectrometry.

The most commonly encountered difficulties for the quantitative measurement of zinc in biological samples are the limited sample amount, total and effective digestion of connective and fatty residues, and low zinc concentrations. These problems often lead to the determination of lower zinc values than actually present, so that the sample preparation, digestion, and analytical procedure deserve careful attention. In this short communication, a new method for microwave tissue disintegration is described. The authors have obtained consistent and reproducible results with tissue samples of 0.5 g or less.