Effect of mechanical extraction parameters on the yield and quality of tobacco (Nicotiana tabacum L.) seed oil.

The aim of this study was to investigate how the combination of extraction parameters, such as extraction temperature seeds preheating and screw rotation speed, influenced the yield and chemical quality of tobacco seed oil (TSO). For its peculiar properties, TSO can be used for several purposes, as raw material in the manufacturing of soap, paints, resins, lubricants, biofuels and also as edible oil. TSO was obtained using a mechanical screw press and the quality of the oil was evaluated by monitoring the free fatty acids (FFA), the peroxide value (PV), the spectroscopic indices K232, K270 and ΔK and the fatty acid composition. The maximum extraction yield, expressed as percent of oil mechanically extracted respect to the oil content in the seeds, determined by solvent extraction, was obtained with the combination of the highest extraction temperature, the slowest screw rotation speed and seeds preheating. Under these conditions yield was 80.28 ± 0.33% (w/w), 25% higher than the lowest yield obtained among investigated conditions. The extraction temperature and seed preheating showed a significant effect on FFA, on spectroscopic indices K232, K270 and ΔK values. The average values of these parameters slightly increased rising the temperature and in presence of preheating, the screw rotation speed did not affect the chemical characteristic tested. In the extraction conditions investigated no significant changes in PV and fatty acids composition of oil were observed.

Female adnexal tumor of probable wolffian origin: clinicopathological, immunohistochemical and cytofluorimetric analyses of a 22-year-old virgin. case report.

The term female adnexal tumor of probable Wolffian origin "FATWO" designs this tumor wich arises by the rare persisting remnants of the mesonephric duct (Wolffian duct). About 40 cases have been reported in literature. Few cases of recurrence have been reported, FATWO usually shows no signs of hormonal activity. We report a case of the youngest patient affected by FATWO in October 2002. At laparotomy the left adnexa were deformed by a well-capsulated mass, totally removed and sent to the pathologist with a specimen of peritoneal fluid and of the omentum. The histological examination showed a prevalent tubular structure with focal retiform area, without intraluminal mucines. Immunohistochemical findings of the case reported are similar to those described by other authors, except for inhibin which has not been detected by us. The cytofluorimetry showed the low presence of aneuploid cells, with a very low prolifing component (< 1%).

AGUS and ASCUS: different incidence in pre- and postmenopausal women.

PURPOSE OF INVESTIGATION: The aim of this study was to determine the incidence of AGUS (atypical glandular cells of undetermined significance), ASCUS (atypical squamous cells of undetermined significance) and SIL (squamous intraepithelial lesion) in the cytologic diagnosis in pre- and postmenopausal women. METHODS: We did a retrospective study selecting 183 patients who were screened for cervical pathology. Ninety-six patients were in postmenopausal age. We determined the incidence of cytologic abnormalities defined as ASCUS, SIL, and AGUS in pre- and postmenopausal women. RESULTS: We expected a marked incidence of low-grade SILs in the fertile population, while the postmenopausal group was thought to be affected more by AGUS and ASCUS. We obtained different results. In our population study, premenopausal women presented more AGUS and ASCUS; the two subgroups presented the same incidence of low-grade SILs; postmenopausal women were more affected by high-grade SILs. CONCLUSIONS: The significance of the new categories introduced by the Bethesda System is still uncertain for different authors. As we look to the future new markers that more specifically identify individuals at-risk can be expected.

Transport and metabolism of double-labelled CDPcholine in mammalian tissues.

Double-labelled [methyl-14C,5-3H]CDPcholine has been synthesized and subjected to a pharmacokinetic analysis in several biological systems. In transport experiments with intact human erythrocytes no incorporation of radioactivity is observable. On the other hand the results obtained with perfused rat liver suggest a rapid cleavage of the pyrophosphate bridge of the molecule, followed by a rapid uptake of the hydrolytic products. The plasma half-lives of intravenously injected CDPcholine and of its metabolites have been evaluated within 60 sec range. Renal and fecal excretion of the injected radioactivity is negligible: only 2.5% of administered 14C- and 6.5% of the 3H- is excreted up to 48 hr after administration. Liver and kidney are the major CDPcholine metabolizing organs, characterized by a fast and extensive uptake of choline metabolites, followed by a slow release; conversely the rate of uptake of both 3H and 14C-labelled moieties by rat brain is significantly slower, reaching a steady-state level after 10 hr. The characterization of the labelled compounds detectable in the investigated organs provides some insights on the metabolism of the drug: the 3H-cytidine moiety in all the examined organs appears to be incorporated into the nucleic acid fraction via the cytidine nucleotide pool; the [14C]choline moiety of the molecule is in part converted, at the mitochondrial level, into betaine which accounts for about 60% of the total 14C-radioactivity associated with liver and kidney 30 min after administration; [14C]betaine in turn acts as methyl donor to homocysteine yielding [14C]methionine subsequently incorporated into proteins; the time dependent increase in labelled phospholipids is indicative of a recycling of the choline methyl-groups in this lipid fraction via CDPcholine and/or S-adenosylmethionine; the rather extensive amount of labelled methionine detectable in brain probably arises from its uptake from the blood stream, since the enzyme catalyzing the conversion of betaine into methionine is lacking in brain.

Studies on enzyme-substrate interactions of cholinephosphotransferase from rat liver.

In order to elucidate the reaction mechanism and the substrate-binding sites, CDPcholine:1,2-diacylglycerol cholinephosphotransferase (EC 2.7.8.2), prepared from rat liver microsomal fraction, has been subjected to kinetic analysis and substrate specificity studies. Kinetic evidence supports the hypothesis of a Bi-Bi sequential mechanism, involving a direct nucleophilic attack of diacylglycerol on CDPcholine during the reaction. To investigate the substrate requirements for recognition and catalysis, several CDPcholine analogs, modified in the nitrogen base or in the sugar or in the pyrophosphate bridge, have been synthesized, characterized and assayed as substrates and/or inhibitors of the reaction. The amino group on the pyrimidine ring, the 2'-alcoholic function of the ribose moiety as well as the pyrophosphate bridge have been identified as critical sites for enzyme-substrates interactions.