Semisolid Enteral Nutrients Alter the Pharmacokinetics of Orally Administered Levetiracetam in Rats.

Enteral nutrients (ENs) affect the plasma drug concentration of orally co-administered drugs, particularly those of antiepileptic drugs, such as phenytoin and carbamazepine. However, few studies have reported the interactions of levetiracetam (LEV), an upcoming antiepileptic drug, with ENs. In this study we aimed to investigate the pharmacokinetics of LEV in 55 rats after oral co-administration of LEV with liquid or semisolid ENs. Compared with the control group, co-administration with Terumeal ® Soft significantly decreased the plasma LEV concentration at 0.5, 1, and 2 h and area under the plasma concentration-time curve from 0 to 3 h (AUC0→3h) (P < 0.01). However, the AUC0→3h of LEV remained unchanged following the administration of Terumeal ® Soft 2 h after the initial LEV administration. Moreover, co-administration with semisolid Racol® NF delayed the absorption of LEV without decreasing the AUC0→3h, whereas liquid Racol ® NF did not alter LEV pharmacokinetics. Thus, co-administration of LEV with Terumeal® Soft reduced the absorption of LEV from the gastrointestinal tract, which was prevented by administering Terumeal ® Soft 2 h after LEV administration. Semisolid Racol ® NF altered LEV pharmacokinetics without decreasing its gastrointestinal absorption. Our findings suggested that careful monitoring of the plasma LEV levels is necessary when co-administering LEV with Terumeal ® Soft, semisolid Racol ® NF, or any other semisolid ENs, to prevent the inadvertent effects of the interaction between LEV and ENs.

Interaction between phenytoin and enteral nutrients and its influence on gastrointestinal absorption.

The gastrointestinal absorption of phenytoin (PHT), an antiepileptic drug, is often affected by its interaction with co-administered enteral nutrients through a nasogastric (NG) tube, resulting in decreased plasma PHT concentration. In this study, we measured the recovery rate (%) of PHT (Aleviatin® powder) passed through an NG tube when co-administered with distilled water or enteral nutrients (F2α®, Racol® NF, Ensure Liquid® and Renalen® LP). We also measured plasma PHT levels in rats, after oral co-administration of PHT with enteral nutrients. We demonstrate that PHT recovery rate was close to 100 % in all cases after passage through the NG tube. In the rat study, the AUC0→∞ of PHT concentration after oral administration significantly decreased when it was co-administered with F2α® and Racol® NF compared to distilled water. However, the AUC0→∞ of PHT was unchanged when co-administered with F2α® 2 h after initial PHT administration. We therefore conclude that the co-administration of PHT with F2α® and Racol® NF caused a reduction in the absorption of PHT from the gastrointestinal tract to the blood, without adsorption to the NG tube. The administration of enteral nutrients 2 h after PHT is one clear way to prevent a decrease in plasma PHT concentration.

Risk factors increasing blood pressure in Japanese colorectal cancer patients treated with bevacizumab.

Bevacizumab has been reported to increase blood pressure. However, the factors, including patient characteristics and laboratory data contributing to this side effect remain unclear. Therefore, we investigated the relationships between increased blood pressure and bevacizumab administration, patient characteristics, and laboratory data. Between April 2007 and January 2018, factor analysis was retrospectively conducted by monitoring increases in blood pressure, the status of bevacizumab administration, patient characteristics, and laboratory data before the first administration in Japanese patients with colorectal cancer who satisfied the criteria for this study. Sixty-seven patients were included, 34 of whom (50.7%) had an increase in blood pressure after bevacizumab administration. On univariate analysis, liver metastasis, antihypertensive drug use, systolic blood pressure at rest before the first bevacizumab administration, body mass index, creatinine, and blood platelet count were significantly different between the two groups. Multivariate analysis was conducted using increased blood pressure as an objective variable and the factors extracted by the univariate analysis as explanatory variables. The results suggested that liver metastasis, antihypertensive drugs, systolic blood pressure at rest before the first bevacizumab administration, and creatinine were associated with the increase in blood pressure. Furthermore, a log-rank test performed based on Kaplan-Meier curves demonstrated that liver metastasis in patients not taking antihypertensive drugs and antihypertensive drug use in patients without liver metastasis were significantly associated with increased blood pressure. Additionally, liver metastasis in patients with antihypertensive drug use was significantly associated with increased blood pressure. Our findings suggest that liver metastasis and antihypertensive drug use, which was previously reported, are risk factors for increased blood pressure.

Production of mice deficient in genes for interleukin (IL)-1alpha, IL-1beta, IL-1alpha/beta, and IL-1 receptor antagonist shows that IL-1beta is crucial in turpentine-induced fever development and glucocorticoid secretion.

Interleukin (IL)-1 is a major mediator of inflammation and exerts pleiotropic effects on the neuro-immuno-endocrine system. To elucidate pathophysiological roles of IL-1, we have first produced IL-1alpha/beta doubly deficient (KO) mice together with mice deficient in either the IL-1alpha, IL-1beta, or IL-1 receptor antagonist (IL-1ra) genes. These mice were born healthy, and their growth was normal except for IL-1ra KO mice, which showed growth retardation after weaning. Fever development upon injection with turpentine was suppressed in IL-1beta as well as IL-1alpha/beta KO mice, but not in IL-1alpha KO mice, whereas IL-1ra KO mice showed an elevated response. At this time, expression of IL-1beta mRNA in the diencephalon decreased 1.5-fold in IL-1alpha KO mice, whereas expression of IL-1alpha mRNA decreased >30-fold in IL-1beta KO mice, suggesting mutual induction between IL-1alpha and IL-1beta. This mutual induction was also suggested in peritoneal macrophages stimulated with lipopolysaccharide in vitro. In IL-1beta KO mice treated with turpentine, the induction of cyclooxygenase-2 (EC 1.14.99.1) in the diencephalon was suppressed, whereas it was enhanced in IL-1ra KO mice. We also found that glucocorticoid induction 8 h after turpentine treatment was suppressed in IL-1beta but not IL-1alpha KO mice. These observations suggest that IL-1beta but not IL-1alpha is crucial in febrile and neuro-immuno-endocrine responses, and that this is because IL-1alpha expression in the brain is dependent on IL-1beta. The importance of IL-1ra both in normal physiology and under stress is also suggested.

Molecular species of prostaglandins involved in modulating luteinising hormone pulses of female rats under infectious stress conditions.

Mammalian reproductive function is controlled by the hypothalamic-pituitary-gonadal (HPG) axis, which is suppressed under infectious stress conditions. By analysing the pulsatility of luteinising hormone (LH), we have previously demonstrated that prostaglandins (PGs) in the central nervous system mediate infectious stress to suppress the activity of the HPG axis. The present study aimed to characterise the types of PGs responsible for suppression of the HPG axis. We focused on three major types of PGs: PGE2 , PGD2 and PGF2α . We used female rats overiectomised bilaterally 1 week before the experiments. Lipopolysaccharide (100 µg kg-1 ) suppressed LH pulses at the same time as enhancing the concentration of all three PGs in the cerebrospinal fluid, which was restored by indomethacin (10 mg kg-1 ). Subsequently, we observed LH pulsatility after a single injection of each PG and after co-injection of PGE2 with PGF2α into the third cerebral ventricle. A single injection of PGE2 dose-dependently induced a transient increase in mean LH concentration and LH pulse amplitude, and PGD2 significantly increased the amplitude of LH pulses, wereas PGF2α did not affect LH pulsatility. On the other hand, co-injection of PGE2 and PGF2α induced a significant suppression of both the frequency and amplitude of LH pulses. These results suggest that PGE2 and PGF2α can represent two of the mediators that suppress the HPG axis in situations of infectious stress. Moreover, the results imply that there are two contradictory effects of PGE2 on LH pulsatility: (i) enhancive when working alone and (ii) suppressive when working together with PGF2α .

Two new phospholipids, hydroxyarchaetidylglycerol and hydroxyarchaetidylethanolamine, from the Archaea Methanosarcina barkeri.

The structures of two new ether phospholipids of the methanogenic Archaea, Methanosarcina barkeri, were determined as hydroxyarchaetidylglycerol and hydroxyarchaetidylethanolamine by means of chemical, chromatographic and enzymatic analyses, and fast atom bombardment-mass spectrometry. These lipids are hydroxy diether analogs of phosphatidylglycerol and phosphatidylethanolamine, respectively, with beta-hydroxyarachaeol (2-O-(3'-hydroxy)phytanyl-3-O-phytanyl-sn-glycerol) as a core lipid. In addition, two other ether phospholipids, usual archaetidylglycerol and archaetidylethanolamine, were also identified in the organism. The stereochemical structure of the unalkylated glycerophosphate of hydroxyarchaetidylglycerol and archaetidylglycerol was determined as sn-glycerol-3-phosphate by use of sn-glycerol-3-phosphate dehydrogenase. The stereochemical configuration of the glycerophosphoglycerol backbone of these lipids was a mirror image of that of diacylphosphatidylglycerol from the organisms of the domains Bacteria and Eucarya, and it was shared with extremely halophilic Archaea. These four phospholipids, in addition to five lipids that had already been reported, accounted for 88% of the total polar lipids of this organism.

Hydroxyarchaetidylserine and hydroxyarchaetidyl-myo-inositol in Methanosarcina barkeri: polar lipids with a new ether core portion.

Lipids of the methanogenic archaebacterium, Methanosarcina barkeri were analyzed. The lipid content was 5.4% of dry cell and polar lipids comprised 87% of the total lipid. Polar lipids were separated into 14 spots by two-dimensional thin-layer chromatography. These were six phospholipids, seven aminophospholipids and one glycolipid, of which two phospholipids and two aminophospholipids were major constituents. After removal of polar head groups from total lipids, two kinds of glycerol diether core lipids were found. One was 2,3-di-O-phytanyl-sn-glycerol (archaeol) and the other 2-O-(3'-hydroxy-3', 7', 11', 15'-tetramethyl)hexadecyl-3-O-phytanyl-sn- glycerol (hydroxyarchaeol). Those structures were identified on the basis of chemical analysis, fast atom bombardment spectrometry, gas-liquid chromatography-mass spectrometry and 1H- and 13C-NMR spectrometry. The latter was a new core lipid which was different from hydroxyarchaeol of Methanothrix concilii. The hydroxyarchaeol core lipid comprised 60% of polar lipid in M. barkeri. The structures of core lipids are quite different from those previously reported by De Rosa et al. (Biochim, Biophys. Acta (1986) 875, 487-492) concerning M. barkeri lipids. The structures of two major polar lipids, both of which had hydroxyarchaeol as core proteins, were elucidated. These lipids were 2-O-(3'-hydroxy)phytanyl-3-O-phytanyl-sn-glycero-1-phosphoserine (hydroxyarchaetidylserine) and 2-O-(3'-hydroxy)phytanyl-3-O-phytanyl-sn- glycerol-phospho-myo-inositol (hydroxyarchaetidyl-myo-inositol). Archaetidylserine and archaetidylinositol, which had the usual archaeol core portion, were also present as minor polar lipids.

Changes in the phospholipid molecular species composition of soybean hypocotyl and cotyledon after dedifferentiation.

The effect of dedifferentiation on the molecular species composition of soybean phospholipids was studied by using hypocotyl, cotyledon and the suspension culture cells established from those organs. Three major phospholipids (phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol) and phosphatidylmonomethylethanolamine were composed of twelve molecular species. Major species were 1-palmitoyl-2-linoleoyl, 1-obeoyl-2-linoleoyl, 1-palmitoyl-2-linolenoyl and 1-linoleoyl-2-linoleoyl species. Different proportions of the molecular species were found among the three major phospholipids, but phosphatidylmonomethylethanolamine was composed of the same proportions of the molecular species as those of phosphatidylethanolamine. After dedifferentiation, the 1-palmitoyl-2-linoleoyl species increased in the cell established from hypocotyl. In the cells established from cotyledon, the 1-palmitoyl-2-linolenoyl species increased dramatically. In both cells, the 1-palmitoyl-2-linolenoyl species increased in response to increase in the 2,4-dichlorophenoxyacetic acid concentrations and the progress of cell growth.

Lipid molecular species composition of thylakoid membranes.

Lipid molecular species compositions of chloroplast thylakoid membranes of mesophyll cells from Spinacia oleracea, Glycine max, Oryza sativa and Zea mays and of bundle sheath cells from Zea mays have been quantitatively determined. No significant difference in the lipid molecular species composition was found among the five membrane sources. The predominant molecular species of monogalactosyldiacylglycerol was the 1-linolenoyl parallel to 2-linolenoyl species. The 1-linolenoyl parallel to 2-linoenoyl and 1-palmitoyl parallel to 2-linolenoyl species were the major molecular species of digalactosyldiacylglycerol. 6-Sulfoquinovosyldiacylglycerol was mainly composed of the palmitoyl parallel to linolenoyl and palmitoyl parallel to lineolyl species. Almost all of the C-2 position of phosphatidylglycerol were esterified with the palmitoyl or delta 3-trans-hexadecenoyl residue. The molecular species compositions of phosphatidylcholine and phosphatidylinositol were basically similar to those of membranes in non-photosynthetic tissues.

Function of phospholipids on the regulatory properties of solubilized and membrane-bound sn-glycerol-3-phosphate acyltransferase of Escherichia coli.

Glycerophosphate acyltransferase (acyl-CoA:sn-glycerol-3-phosphate O-acyltransferase, EC 2.3.1.15) solubilized from Escherichia coli membranes was highly activated by phosphatidylglycerol. Phosphatidylethanolamine, cardiolipin and 1,2-diacyl-sn-glycerol 3-phosphate showed no effect. The Km of the enzyme for sn-glycerol 3-phosphate was increased 20-fold by solubilization. The value could not be restored by the addition of phospholipids. Temperature-sensitive regulation of the synthesis of either 1-palmitoyl- or cis-vaccenoyl-sn-glycerol 3-phosphate by the solubilized enzyme was identical with that by the membrane-bound enzyme in vivo and in vitro. The proportion of the molecular species of 1-acyl-sn-glycerol 3-phosphate varied when the ratios of palmitoyl-CoA and cis-vaccenoyl-CoA were changed, but changes in the sn-glycerol 3-phosphate concentration had no effect on selective acylation by both the solubilized and membrane-bound enzymes.

Purification and positional specificity of sn-glycerol-3-phosphate acyltransferase from Escherichia coli membranes.

SN-Glycerol-3-phosphate acyltransferase was solubilized from membranes of Escherichia coli B and K-12 and purified on an affinity column of Sepharose 4B coupled with 6-phosphogluconic acid. Phosphatidylglycerol was required for activation and stabilization of the purified enzyme. The acyl residues were exclusively transferred to the position 1 of sn-glycerol 3-phosphate by the enzyme, regardless of whether the acyl-CoA was saturated or unsaturated.

Products of phosphatidylglycerol turnover in two Bacillus strains with and without lipoteichoic acid in the cells.

In order to understand the phosphatidylglycerol turnover mechanism, especially the differential turnover of diacylated and unacylated glycerol moieties of the lipid, products of phosphatidylglycerol metabolism were surveyed in vivo in Bacillus subtilis W23 and an alkalophile, Bacillus sp. strain A007. When cells of B. subtilis W23 labeled with radioactive glycerol were chased, lipoteichoic acid accumulated 90% of the radioactivity lost from the unacylated glycerol moiety of phosphatidylglycerol. Also, lipids other that phosphatidylglycerol, except diacylglycerol, and glycerol and glycerophosphate incorporated much less radioactivity. The [32P]phosphoryl group was also transferred from phosphatidylglycerol to lipoteichoic acid almost quantitatively in B. subtilis W23. A unique metabolism of phosphatidylglycerol was found in Bacillus sp. strain A007 which lacked phosphoglycolipid and lipoteichoic acid, that is, the turnover of phosphatidylglycerol of this organism was less extensive compared with that of B. subtilis W23, and both glycerol moieties of the lipid were metabolized at an identical rate. These results suggested that the major reaction involved in the turnover of phosphatidylglycerol was the transfer of glycerophosphate residue to lipoteichoic acid in a bacterium which possessed lipoteichoic acid and that several minor reactions also were involved in phosphatidylglycerol turnover.

Inositol phospholipid levels of rat forebrain obtained by freeze-blowing method.

Four different techniques of handling rat brain prior to lipid extraction and assay were tested to investigate the levels of inositol phospholipids in the brain. In these four techniques, the rat forebrains were either (1) freeze-blown followed by being preserved in liquid N2, (2) subjected to microwave irradiation prior to decapitation, (3) removed and frozen in liquid N2, or (4) removed at room temperature and subjected to lipid extraction as rapidly as possible. There was little change in phosphatidylinositol levels under any of these conditions; however, higher levels of phosphatidylinositol 4-phosphate were observed in freeze-blown and microwave-irradiated samples compared to the other samples. Even more striking differences were seen in phosphatidylinositol 4,5-bisphosphate fractions. The highest level of this lipid, 763 +/- 39 nmol/g tissue, which was obtained from freeze-blown samples, was more than 2-fold higher than that of the lowest values which were obtained by extraction without prior inactivation. These results indicate that the values of phosphatidylinositol 4,5-bisphosphate in brain in situ are higher than those generally reported, and that the freeze-blowing method has an advantage for further investigation of inositol phospholipid metabolism in brain due to the rapid breakdown of these compounds.

Relation between growth temperature of E. coli and phase transition temperatures of its cytoplasmic and outer membranes.

Cells of wild-type E. coli B were grown at 17, 27 and 38 degrees C, and their cell membranes were fractionated into the cytoplasmic and the outer membranes. Chemical assay proved that the molar ratio of saturated to unsaturated fatty acids increases in phospholipids extracted from each membrane as the growth temperature increases. The transition temperature at which the solid phase disappears was determined by X-ray diffraction in these biomembranes and also membranes of extracted phospholipids and of extracted lipopolysaccharide. The transition temperatures of the cytoplasmic membrane and of the membranes of phospholipids extracted from the cytoplasmic and the outer membranes increased with the growth temperature in good parallelism to the molar ratio of saturated to unsaturated fatty acids. The transition temperature of the outer membrane was less sensitive to the growth temperature, presumably due to the presence of lipopolysaccharide. The transition temperature of the membranes of lipopolysaccharide extracted from the outer membrane was 25 degrees C, for the cells grown at 27 and 37 degrees C. For the cells grown at 17 degrees C, the extracted lipopolysaccharide gave a broad diffraction peak and did not exhibit a solid-fluid phase transition between --5 and 40 degrees C.

Function of phosphatidylglycerol molecular species in membranes. Activation of membrane-bound sn-glycerol 3-phosphate acyltransferase in Escherichia coli.

SN-Glycerol 3-phosphate acyltrasferase (EC 2.3.1.15) bound to the elaidate enriched membranes of an unsaturated fatty acid auxotroph of Escherichia coli had a lower specific activity than the acyltrasferase associated with the wild-type membranes. The 1-saturated-2-cis-unsaturated and 1,2-di-cis-unsaturated molecular species of phosphatidylglycerol activated this enzyme. However, these molecular species did not change the original temperature profile obtained by Arrhenius plots of the enzyme activity bound to the elaidate-enriched membranes.

Temperature-sensitive formation of the phospholipid molecular species in Escherichia coli membranes.

Phospholipids in the membranes of Escherichia coli grown at 37 degrees C are composed of different proportions of molecular species than are those at 17 degrees C. The 1,2-disaturated and 1-saturated-2-unsaturated molecular species increased at 37 degrees C, but the 1,2-diunsaturated species increased at 17 degrees C. When the growth temperature was lowered from 37 to 17 degrees C during the middle exponential growth phase, phosphatidylethanolamine and phosphatidylglycerol composed of proportions of molecular species similar to those found at 17 degrees C were immediately synthesized. By using various membranes composed of different compositions of the phospholipid molecular species, the temperature-sensitive formation of the phospholipid molecular species was found to be independent of the composition of the membrane phospholipids and to be dependent on changes in the specificities of membrane-bound sn-glycerol 3-phosphate acyltransferase against the acyl-CoAs, due to temperature changes.

A novel ether core lipid with H-shaped C80-isoprenoid hydrocarbon chain from the hyperthermophilic methanogen Methanothermus fervidus.

A new ether lipid core (designated as FU) was found in Methanothermus fervidus total lipid. Comparison with caldarchaeol showed lower mobility of FU on TLC and smaller molecular weight (m/z 1298) by 2 mass units on FAB-MS. Treatment of FU with HI followed by displacement with silver acetate afforded long chain alcohol acetate (ROAc), which was further saponified with mild alkali to its free alcohol (ROH). ROH is the long chain alcohol prepared from FU. The molecular weights of ROAc and ROH were shown by MS to be 1354 and 1186, respectively. These results suggested that the molecular formula of ROH was C80H162O4, and ROH had four hydroxyl groups, and one molecule of ROH was bound with two molecules of glycerol by four ether linkages. Because FU was not oxidized by NaIO4 and specific rotation [alpha]D of FU coincided with that of caldarchaeol, it seems that the ether linkages of FU are formed with hydroxyl groups of the sn-2 and sn-3 positions of each glycerol moiety. The structure of FU was suggested to be a modified caldarchaeol in which two hydrocarbon chains are bridged with a covalent bond. Although a few points remain to be elucidated before the final conclusion can be reached on the structure of FU due to difficulty in complete structure determination done even with every approach currently available, the most possible position of the bridge in FU hydrocarbon was proposed from the data of EI-MS of ROAc and 1H-NMR of FU. The hydrocarbon chain looks like H-shaped C80 isoprenoid.

Phosphatidylethanolamine molecular species of fatty acid auxotroph of Escherichia coli grown with elaidate.

Monoacetyldiglycerides derived from the phosphatidylethanolamine molecular species of the fatty acid auxotroph of Escherichia coli grown with elaidate at 37 degrees C were fractionated on thin-layer plates of silica impregnated with silver nitrate and were identified by gas chromatography-mass spectrometry with an OV-17 column and gas chromatography with a Silar-10C column. Phosphatidylethanolamine was made up of the following molecular species: 1-16 : 0-2-16 : 0 (1.2%), 1-14 : 0-2-trans-16 : 1 (1%), 1-16 : 0-2 trans-16 : 1 (3.5%), 1-16 : 0-2-trans-18 : 1 (26.4%), 1-16 : 0-2-cis-16 : 1 (3.8%), 1-trans-18 : 1-2-trans-16 : 1 (13.2%), 1-trans-18 : 1-2-trans-18 : 1 (44.9%), 1-trans-18 : 1-2-cis-16 : 1 (4.5%) and trans-18 : 1-cis-18 : 1 (1.5%).

Expression of the [beta]-Glucuronidase Gene in Pollen of Lily (Lilium longiflorum), Tobacco (Nicotiana tabacum), Nicotiana rustica, and Peony (Paeonia lactiflora) by Particle Bombardment.

A [beta]-glucuronidase (GUS) gene that is under the control of the anther-specific LAT52 promoter of tomato (Lycopersicon esculentum) and the nopaline synthetase polyadenylation terminator was successfully expressed in pollen of Lilium longiflorum, Nicotiana tabacum, Nicotiana rustica, and Paeonia lactiflora using a pneumatic particle gun. The GUS gene in plasmid pBI221 was also expressed, to a lesser extent, in pollen of all of these species. The presence of methanol in the substrate solution for histochemical GUS assay and the incubation time in this solution influenced successful detection of GUS expression in bombarded pollen. Cytological analysis of GUS-expressing pollen of lily showed that introduced gold particles were seen in intracellular compartments of pollen, including the vegetative cytoplasm, vegetative nucleus, and generative cytoplasm.