Formation of Pt decorated Ni-Pt nanocubes through low temperature atomic diffusion--time-resolved elemental analysis of nanoparticle formation

The formation process of Pt decorated Ni-Pt nanocubes was investigated by analysing the elemental distribution of Ni and Pt in the particles obtained from time-resolved in situ sampling during the synthesis in the oleylamine-1-heptanol system. The analysis confirmed the formation of Pt(core)-Ni(shell) nanoparticles at the initial stages of the reaction. However, as the reaction time progressed, the Pt atoms at the centre diffused outward and reached the corners and edges of the particle, whose shape changed from nearly spherical at the initial stages of the reaction to a perfect cube at the end of the reaction, forming a Ni rich cube (core)-Pt(cage). The cage obtained by dissolving the Ni rich cube was composed mainly of Pt and the Ni content in the frame was a mere 12%. The catalytic activity of the Pt cage was measured using cyclic voltammetry. The initial measurements suggested that the activity was comparable to some of the commercially available Pt catalysts.

Early predictors of status epilepticus-associated mortality and morbidity in children

BACKGROUND

Early predictors of status epilepticus (SE)-associated mortality and morbidity have not been systematically studied in children, considerably impeding the identification of patients at risk.

OBJECTIVES

To determine reliable early predictors of SE-associated mortality and morbidity and identify the etiology of SE-associated sequelae in Japanese children.

METHODS

We conducted a prospective multicenter study of clinical findings and initial laboratory data acquired at SE onset, and assessed outcomes at the last follow-up examination. In-hospital death during the acute period and neurological sequelae were classified as poor outcomes.

RESULTS

Of the 201 children who experienced their first SE episode, 16 exhibited poor outcome that was most commonly associated with acute encephalopathy. Univariate analysis revealed that the following were associated with poor outcomes: young age (⩽24 months); seizure duration >90 min; seizure intractability (failure of the second anticonvulsive drug); biphasic seizures; abnormal blood glucose levels (<61 or >250 mg/dL); serum aspartate aminotransferase (AST) ⩾56 U/L; and C-reactive protein (CRP) levels >2.00 mg/dL. Multivariate analysis revealed that young age, seizure intractability, abnormal blood glucose levels, and elevated AST and CRP levels were statistically significant.

CONCLUSIONS

Young age and seizure intractability were highly predictive of poor outcomes in pediatric SE. Moreover, abnormal blood glucose levels and elevated AST and CRP levels were predictors that might be closely associated with the etiology, especially acute encephalopathy and severe bacterial infection (sepsis and meningitis) in Japanese children.

Solute dependence of mobility of solvent molecules in solvophobic solute solutions: Dielectric relaxation of nonpolar solute/alcohol mixtures

The dielectric relaxation spectra of alcohol/nonpolar solute mixtures are measured at several temperatures (-15 degrees C < or = T < or = 25 degrees C) and for several molar fractions of solute (0 < or = X(s) < or = 0.114) in the frequency range of 200 MHz < or = nu < or = 20 GHz. The double-Debye-type function is used for fitting of the spectra of mixtures, and the mean dielectric relaxation times (tau(mean)) of alcohol molecules are determined. In the systems having strong interaction between alcohol and nonpolar solutes, tau(mean) becomes shorter with an increase in the concentration of the solutes. On the other hand, tau(mean) becomes longer in the system having weak interaction between alcohol and nonpolar solutes. These results contradict with our intuitive predictions, do not correspond to mixing enthalpy, and are not explained by the hydrodynamic theory. They are attributed to the mechanism of the coupling between long-range electrostatic interactions and concentration fluctuation caused by the addition of solutes, which is suggested by Yamaguchi et al. based on the mode-coupling theory (Yamaguchi, T.; Matsuoka, T.; Koda, S. J. Chem. Phys. 2004, 120, 7590).

Clonal structure and flowering traits of a bamboo [Phyllostachys pubescens (Mazel) Ohwi] stand grown from a simultaneous flowering as revealed by AFLP analysis

Abstract Although many bamboo species are characterized by simultaneous flowering at long intervals of up to 120 years, few studies have revealed the length of the flowering interval for very-long-lived bamboo species by observing the whole life cycle of a single clone. The flowering interval of Phyllostachys pubescens had been determined to be 67 years by means of observation through the entire life cycle from 1912 to 1979. We observed and analysed the clonal structure and flowering traits of a P. pubescens community which had regenerated from seed in 1930 and began to flower in 1997. Although this interval was again 67 years, flowering and nonflowering culms were mixed, and the flowering event lasted three years in the community. AFLP analysis of DNA samples showed distinct genets that originated from the previous flowering event and that each genet had its own flowering time. This is the first report to show that (i) different genets are mixed in a community of a large bamboo species with a leptomorphic rhizome system, and (ii) a community that originated from a single flowering event can have a range of flowering years.

[Ventricular free wall re-rupture after surgical treatment of ventricular free wall rupture due to acute myocardial infarction; report of a case]

An in-hospital 72-year-old male with complaint of anterior chest pain was presented with shock. Pericardial effusion was confirmed by echocardiography, and therefore, he was brought to the operating room immediately with diagnosis of ventricular free wall rupture. The repair was performed using fibrin glue, fibrin sheet, and pericardial patch. His post-operative course was uneventful until massive bleeding came through the chest tube on the 5th day from the initial surgery. The emergency sternotomy was made again for hemostasis. In the re-operation, an approximately 20 mm laceration along the proximal circumflex artery was found and this was successfully repaired with 2 pledgetted horizontal mattress sutures. It is important and necessary to treat a postoperative patient taking care of re-rupture.

Acyclic carotenoids and their oxidation mixtures inhibit the growth of HL-60 human promyelocytic leukemia cells

Lycopene has been known as a potential food component for cancer prevention, since tomato consumption was shown to be associated with reduced risk of certain cancers. We used HL-60 cells as a model of cancer cells to investigate whether acyclic carotenoids, such as phytoene, phytofluene, and zeta-carotene present in tomatoes, other than lycopene, as well as oxidation mixtures of these carotenoids, are potentially involved in the cancer-preventive action of tomatoes. When HL-60 cells were grown in the carotenoid-supplemented medium for 120 hours, zeta-carotene and phytofluene at 10 microM inhibited cell growth to 3.7% and 22.6% of the growth in control culture, respectively, although they were extremely unstable in the culture medium. The oxidation mixture of each carotenoid, which was prepared by incubation in toluene at 37 degrees C for 24 hours, more strongly inhibited cell growth than each intact carotenoid. The growth inhibition by lycopene was remarkably enhanced by its oxidation before supplementation to the medium. Phytofluene, zeta-carotene, and the oxidation mixture of lycopene induced apoptosis in HL-60 cells during incubation for 24 hours. The addition of alpha-tocopherol to the medium did not eliminate growth inhibition by the oxidation mixture of lycopene. These results suggest that the acyclic carotenoids inhibit cell growth through apoptosis induction and that oxidation products of the carotenoids participate in the growth inhibition.

Carotenoids affect proliferation of human prostate cancer cells

We investigated whether various carotenoids present in foodstuffs were potentially involved in cancer-preventing action on human prostate cancer. The effects of 15 kinds of carotenoids on the viability of three lines of human prostate cancer cells, PC-3, DU 145 and LNCaP, were evaluated. When the prostate cancer cells were cultured in a carotenoid-supplemented medium for 72 h at 20 micromol/L, 5,6-monoepoxy carotenoids, namely, neoxanthin from spinach and fucoxanthin from brown algae, significantly reduced cell viability to 10.9 and 14.9% for PC-3, 15.0 and 5.0% for DU 145, and nearly zero and 9.8% for LNCaP, respectively. Acyclic carotenoids such as phytofluene, zeta-carotene and lycopene, all of which are present in tomato, also significantly reduced cell viability. On the other hand, phytoene, canthaxanthin, beta-cryptoxanthin and zeaxanthin did not affect the growth of the prostate cancer cells. DNA fragmentation of nuclei in neoxanthin- and fucoxanthin-treated cells was detected by in situ TdT-mediated dUTP nick end labeling (TUNEL) assay. Neoxanthin and fucoxanthin were found to reduce cell viability through apoptosis induction in the human prostate cancer cells. These results suggest that ingestion of leafy green vegetables and edible brown algae rich in neoxanthin and fucoxanthin might have the potential to reduce the risk of prostate cancer.

Lysophosphatidylcholine enhances carotenoid uptake from mixed micelles by Caco-2 human intestinal cells

Despite the interest in the beneficial roles of dietary carotenoids in human health, little is known about their solubilization from foods to mixed bile micelles during digestion and the intestinal uptake from the micelles. We investigated the absorption of carotenoids solubilized in mixed micelles by differentiated Caco-2 human intestinal cells, which is a useful model for studying the absorption of dietary compounds by intestinal cells. The micelles were composed of 1 micromol/L carotenoids, 2 mmol/L sodium taurocholate, 100 micromol/L monoacylglycerol, 33.3 micromol/L fatty acid and phospholipid (0-200 micromol/L). The phospholipid content of micelles had profound effects on the cellular uptake of carotenoids. Uptake of micellar beta-carotene and lutein was greatly suppressed by phosphatidylcholine (PC) in a dose-dependent manner, whereas lysophosphatidylcholine (lysoPC), the lipolysis product of PC by phospholipase A2 (PLA2), markedly enhanced both beta-carotene and lutein uptake. The addition of PLA2 from porcine pancreas to the medium also enhanced the uptake of carotenoids from micelles containing PC. Caco-2 cells could take up 15 dietary carotenoids, including epoxy carotenoids, such as violaxanthin, neoxanthin and fucoxanthin, from micellar carotenoids, and the uptakes showed a linear correlation with their lipophilicity, defined as the distribution coefficient in 1-octanol/water (log P(ow)). These results suggest that pancreatic PLA2 and lysoPC are important in regulating the absorption of carotenoids in the digestive tract and support a simple diffusion mechanism for carotenoid absorption by the intestinal epithelium.

Ancestral MADS box genes in Sugi, Cryptomeria japonica D. Don (Taxodiaceae), homologous to the B function genes in angiosperms

In flowering plants, flower organ identity is controlled by the ABC genes, including several MADS box genes. We present two MADS box genes of a conifer, Cryptomeria japonica D. Don. The genes, CjMADS1 and CjMADS2, were related to the angiosperm B function genes which determine the identities of petals and stamens. A phylogenetic analysis showed that these genes form a new clade outside the angiosperm B group, that is, PISTILLATA (PI) and APETALA3 (AP3) lineages. CjMADS1 had a PI-group specific motif and CjMADS2 had AP3-group specific motifs at the C terminal end, respectively. CjMADS1 was expressed in male strobili (or cones) throughout its development, while CjMADS2 was transiently expressed during male strobilus development. The specific expression in the male reproductive organ indicated that the B function is maintained in gymnosperms. Our cladistic analysis suggests that the gene duplication event which generated B function gene lineages predates the divergence of angiosperms and gymnosperms and that the gene duplication which produced the two genes of C. japonica occurred in an ancestral conifer species.

Formation of cleavage products by autoxidation of lycopene

The cleavage products formed by autoxidation of lycopene were evaluated in order to elucidate possible oxidation products of lycopene in biological tissues. Lycopene solubilized at 50 microM in toluene, aqueous Tween 40, or liposomal suspension was oxidized by incubating at 37 degrees C for 72 h. Among a number of oxidation products formed, eight products in the carbonyl compound fraction were identified as 3,7,11 -trimethyl-2,4,6,10-dodecatetraen-1-al, 6,10,14-trimethyl-3,5,7,9,13-pentadecapentaen-2-one, acycloretinal, apo-14'-lycopenal, apo-12'-lycopenal, apo-10'-lycopenal, apo-8'-lycopenal, and apo-6'-lycopenal. These correspond to a series of products formed by cleavage in the respective 11 conjugated double bonds of lycopene. The maximal formation of acycloretinal was 135 nM in toluene, 49 nM in aqueous Tween 40, and 64 nM in liposomal suspension. Acycloretinoic acid was also formed by autoxidation of lycopene, although its formation was lower in the aqueous media than in toluene. The pig liver homogenate had the ability to convert acycloretinal to acycloretinoic acid, comparable to the conversion of all-transretinal to all-trans-retinoic acid. These results suggest that lycopene might be cleaved to a series of apolycopenals and short-chain carbonyl compounds under the oxidative conditions in biological tissues and that acycloretinal is further enzymatically converted to acycloretinoic acid.

Acyclic carotenoids and their oxidation mixtures inhibit the growth of HL-60 human promyelocytic leukemia cells

Lycopene has been known as a potential food component for cancer prevention, since tomato consumption was shown to be associated with reduced risk of certain cancers. We used HL-60 cells as a model of cancer cells to investigate whether acyclic carotenoids, such as phytoene, phytofluene, and zeta-carotene present in tomatoes, other than lycopene, as well as oxidation mixtures of these carotenoids, are potentially involved in the cancer-preventive action of tomatoes. When HL-60 cells were grown in the carotenoid-supplemented medium for 120 hours, zeta-carotene and phytofluene at 10 microM inhibited cell growth to 3.7% and 22.6% of the growth in control culture, respectively, although they were extremely unstable in the culture medium. The oxidation mixture of each carotenoid, which was prepared by incubation in toluene at 37 degrees C for 24 hours, more strongly inhibited cell growth than each intact carotenoid. The growth inhibition by lycopene was remarkably enhanced by its oxidation before supplementation to the medium. Phytofluene, zeta-carotene, and the oxidation mixture of lycopene induced apoptosis in HL-60 cells during incubation for 24 hours. The addition of alpha-tocopherol to the medium did not eliminate growth inhibition by the oxidation mixture of lycopene. These results suggest that the acyclic carotenoids inhibit cell growth through apoptosis induction and that oxidation products of the carotenoids participate in the growth inhibition.

Protective effect of phytic acid hydrolysis products on iron-induced lipid peroxidation of liposomal membranes

Beneficial effects of dietary phytic acid (myo-inositol hexaphosphate; IP6) have often been explained by its strong iron ion-chelating ability, which possibly suppresses iron ion-induced oxidative damage in the gastrointestinal tract. Because phytic acid is hydrolyzed during digestion, this work aimed to know whether its hydrolysis products (IP2, IP3, IP4, and IP5) could still prevent iron ion-induced lipid peroxidation. Studies using liposomal membranes demonstrated that hydrolysis products containing three or more phosphate groups are able to inhibit iron ion-induced lipid peroxidation although their effectiveness decreased with dephosphorylation. Similarly, they also prevented iron ion-induced decomposition of phosphatidylcholine hydroperoxide. These results demonstrate that intermediate products of phytic acid hydrolysis still possess iron ion-chelating ability, and thus they can probably prevent iron ion-induced lipid peroxidation in biological systems.

[Studies on simultaneous determination of 17 organochlorine and 9 pyrethroid pesticides of agricultural products]

A method for simultaneous determination of 17 organochlorine and 9 pyrethroid pesticides in agricultural products by capillary GC with ECD detection was studies. The samples were extracted with acetone under acidic conditions followed by Florisil column clean-up and then injected into a GC-ECD. The organochlorine pesticides used in this study included unstable captan and captafol in the homogenized preparations of fruits and vegetables. Captan and captafol were also found to decompose in rice and wheat samples when the samples were allowed to stand after the addition of water. Addition of phosphoric acid to the samples was effective in preventing the decomposition of captan and captafol. Recovery of the pesticides investigated in this study was not decreased by the addition of phosphoric acid. Addition of phosphoric acid was also effective in removing interfering substances from onion extract. Recovery of organochlorine and pyrethroid pesticides from samples spiked at levels of 0.05-0.25 ppm by the proposed method was 51.4-100.8% for rice and wheat and 60.1-119.0% for vegetables.

Inhibition of beta-carotene-15,15'-dioxygenase activity by dietary flavonoids

Beta-carotene-15,15'-dioxygenase is an enzyme responsible for providing vertebrates with vitamin A by catalyzing oxidative cleavage of beta-carotene at its central double bond to two molecules of retinal in intestinal cells. However, little data have been reported regarding regulation of the enzyme activity. We have evaluated the effects of antioxidants and dietary flavonoids on the beta-carotene dioxygenase activity in vitro using a pig intestinal homogenate as the enzyme source. 2,6-Di-tert-butyl-4-methylphenol (BHT), a synthetic antioxidant, strongly inhibited the activity at the level of 10(-6) M (a mixed-type inhibition), whereas butylated hydroxyanisole, nor-dihydroguaiaretic acid, n-propyl gallate, and curcumin were moderately inhibitory. Flavonoids such as luteolin, quercetin, rhamnetin, and phloretin remarkably inhibited the dioxygenase activity noncompetitively, whereas flavanones, isoflavones, catechins, and anthocyanidins were less inhibitory. The structure-activity relationship indicated that catechol structure of ring B and a planar flavone structure were essential for inhibition. The enzyme inhibition was also indicated in the cultured Caco-2 cells by the significantly reduced conversion of beta-carotene to retinol when incubated with BHT and rhamnetin at 2 microM and 5 microM, respectively. The results suggest that some dietary antioxidants derived from food sources modulate conversion of beta-carotene to vitamin A in intestinal cells.

Severely displaced scaphoid fracture treated by arthroscopic assisted reduction and osteosynthesis

The severely displaced scaphoid fracture, when combined with a scapholunate dissociation, is a very rare condition that commonly is treated by open surgery. The authors present a case treated by arthroscopic-assisted closed reduction, using percutaneous pinning for the scapholunate dissociation and a Herbert/Whipple screw insertion for the scaphoid fracture. The patient was able to return to work four months after surgery. At twenty-seven months after surgery, both the patient's grip power and range of motion in the wrist were acceptable. The authors recommend this procedure as a minimally invasive operation.

Inhibitory effect of quercetin metabolites and their related derivatives on copper ion-induced lipid peroxidation in human low-density lipoprotein

To determine the antioxidant activity of dietary quercetin (3,3',4', 5,7-pentahydroxyflavone) in the blood circulation, we measured the inhibitory effect of quercetin metabolites and their related derivatives on copper ion-induced lipid peroxidation of human low-density lipoprotein (LDL). Conjugated quercetin metabolites were prepared from the plasma of rat 1 h after oral administration of quercetin aglycone (40 micromol/rat). The rate of cholesteryl ester hydroperoxide (CE-OOH) accumulation and the rate of alpha-tocopherol consumption in mixtures of LDL solution (0.4 mg/ml) with equal volumes of this preparation were slower than the rates in mixtures of LDL with preparations from control rats. The concentrations of CE-OOH after 2 h oxidation in the mixtures of LDL with preparations of conjugated quercetin metabolites were significantly lower than those in the control preparation. It is therefore confirmed that conjugated quercetin metabolites have an inhibitory effect on copper ion-induced lipid peroxidation in human LDL. Quercetin 7-O-beta-glucopyranoside (Q7G) and rhamnetin (3,3',4', 5-tetrahydroxy-7-methoxyflavone) exerted strong inhibition and their effect continued even after complete consumption, similarly to quercetin aglycone. The effect of quercetin 3-O-beta-glucopyranoside (Q3G) did not continue after its complete consumption, indicating that the antioxidant mechanism of quercetin conjugates lacking a free hydroxyl group at the 3-position is different from that of the other quercetin conjugates. The result that 4'-O-beta-glucopyranoside (Q4'G) and isorhamnetin (3,4',5, 7-tetrahydroxy-3'-methoxyflavone) showed little inhibition implies that introduction of a conjugate group to the position of the dihydroxyl group in the B ring markedly decreases the inhibitory effect. The results of azo radical-induced lipid peroxidation of LDL and the measurement of free radical scavenging capacity using stable free radical, 1,1,-diphenyl-2-picrylhydrazyl, demonstrated that the o-dihydroxyl structure in the B ring is required to exert maximum free radical scavenging activity. It is therefore likely that conjugation occurs at least partly in positions other than the B ring during the process of metabolic conversion so that the inhibitory effect of dietary quercetin is retained in blood plasma after absorption.

Inhibition of xanthine oxidase by flavonoids

Various dietary flavonoids were evaluated in vitro for their inhibitory effect on xanthine oxidase, which has been implicated in oxidative injury to tissue by ischemia-reperfusion. Xanthine oxidase activity was determined by directly measuring uric acid formation by HPLC. The structure-activity relationship revealed that the planar flavones and flavonols with a 7-hydroxyl group such as chrysin, luteolin, kaempferol, quercetin, myricetin, and isorhamnetin inhibited xanthine oxidase activity at low concentrations (IC50 values from 0.40 to 5.02 microM) in a mixed-type mode, while the nonplanar flavonoids, isoflavones and anthocyanidins were less inhibitory. These results suggest that certain flavonoids might suppress in vivo the formation of active oxygen species and urate by xanthine oxidase.

[A case of local recurrence of rectal cancer responding to local intraarterial infusion therapy]

A 42-year-old male developed pain in the right gluteal region due to local recurrence after curative resection of advanced lower rectal cancer. Radiotherapy (60 Gy) was performed, but satisfactory results were not obtained. Therefore, a reservoir was placed lowing cannulation of the internal iliac artery. The chemotherapy, in addition to intravenous administration of low dose CDDP (20 mg), included local intraarterial infusion therapy with 5-FU (1,500 mg/5 hour) once per week. After 10 courses of this chemotherapy (total dose: CDDP, 200 mg; 5-FU, 15,000 mg), the pain decreased, and the tumor size was reduced without side effects, improving the patient's QOL. At present, multidisciplinary treatments including such chemotherapy and radiotherapy is performed for local recurrence of rectal cancer, but adequate results are often not obtained. Local intraarterial infusion chemotherapy via the internal iliac artery accompanied by changes in blood flow can be safely performed on an outpatient basis, and appears to be effective for local recurrence of rectal cancer.

beta-carotene 15,15'-dioxygenase activity and cellular retinol-binding protein type II level are enhanced by dietary unsaturated triacylglycerols in rat intestines

The purpose of this study was to examine effects of dietary triacylglycerols on beta-carotene 15,15'-dioxygenase (EC 1.13.11.21) activity and cellular retinol-binding protein [CRBP (II)] in rats. Six groups of eight rats (7-wk old) were fed one of the following diets: standard (STD; 2.5% soybean oil), saturated (SFA; 15% hydrogenated soybean oil), monounsaturated (MUFA; 15% olive oil), polyunsaturated (PUFA; 15% soybean oil) or clofibrate (CLF; 2.5% soybean oil + 0.2% clofibrate) for 3 wk. The dioxygenase specific activities of the intestinal homogenates in the MUFA and PUFA groups fed the high fat diets were 2.4 times that of the STD group fed a low fat diet (P < 0.01), whereas the activities of the SFA and CLF groups were not significantly different from that of the STD group. The level of CRBP (II) in the intestine of the PUFA group was 1. 3-fold that of the STD group (P < 0.05), whereas there were no significant differences among the other groups. In a second experiment, the dioxygenase activity of rat intestine was followed over 3 wk of feeding the STD and PUFA diets. After the PUFA diet was consumed for 1 d, the activity was enhanced to 2.7 times the baseline level and remained thereafter at that high level, whereas the activity of the STD group remained at the low baseline level. Thus, dietary polyunsaturated triacylglycerols enhanced both beta-carotene 15,15'-dioxygenase activity and CRBP (II) level in rat intestine. These results suggest that the dioxygenase and CRBP (II) are regulated by the same mechanism involving long-chain fatty acids and their metabolites.

Assay of beta-carotene 15,15'-dioxygenase activity by reverse-phase high-pressure liquid chromatography

beta-Carotene 15,15'-dioxygenase catalyzes the conversion of beta-carotene into two molecules of retinal. Although this enzyme reaction is the first step in providing animals with vitamin A, there is little knowledge about its regulation in mammals. In order to facilitate studies on this enzyme, we have developed a rapid and simple assay method for the measurement of retinal formation by beta-carotene dioxygenase. All-trans-beta-carotene solubilized in aqueous solution with Tween 40 was incubated with an enzyme preparation of rat tissue at 37 degrees C for 30 min. Then, the reaction was stopped with a formaldehyde treatment followed by addition of acetonitrile. After centrifugation, the supernatant was directly subjected to high-pressure liquid chromatographic analysis of retinal. This assay method did not involve any vigorous extraction or concentration procedure. All-trans- and 13-cis-retinals, major geometric isomers found in the reaction mixture, were coeluted at 7.5 min, but they were well separated from other possible metabolites of beta-carotene such as retinoic acid, retinol, and apocarotenals. Moreover, the recovery of retinal reached more than 93% and the detection limit of standard retinal was 0.2 pmol/0.2 ml of reaction mixture. Enzyme activities of rat tissues were 694, 180, 16, 8, and approx 1 pmol retinal/mg protein/h in the intestine, liver, brain, lung, and kidney homogenates, respectively.

Stoichiometric conversion of all trans-beta-carotene to retinal by pig intestinal extract

beta-Carotene and other provitamin A carotenoids are major dietary sources of vitamin A for humans and for many animals throughout the world. Two pathways for this oxidative reaction in mammals are: (1) central cleavage by beta-carotene 15,15'-dioxygenase (EC 1.13.11.21) to yield two molecules of retinal per molecule of beta-carotene consumed and (2) eccentric (or random) cleavage via several beta-apo carotenals to yield one molecule of retinal and various smaller fragments per molecule of beta-carotene oxidized. By the use of improved methods to minimize nonenzymatic reactions and to measure isomers of retinal, the mean experimentally measured molar ratio of retinal formed to beta-carotene consumed by pig intestinal preparations (800 and 10,000g supernatants) was 1.88 +/- 0.08, close to the theoretical value of 2.0 for central cleavage. beta-Apo carotenals, retinol, and retinoic acid were detected, if at all, in trace amounts during incubation. Thus, preparations of pig intestinal mucosa, which is considered a good physiologic model for human intestine, clearly convert beta-carotene to retinal, in large part if not solely, by central cleavage. Whether eccentric cleavage plays a greater role in vivo than it does in vitro is still uncertain.

[Clinical and laboratory studies on SY5555 in pediatric infectious diseases]

Clinical effects of SY5555 dry syrup, a new oral penem antibiotic, were analysed in 20 children with various bacterial infections. Ages of the patients varied from 8 months to 14 years. Doses of SY5555 were varied from 12.8 mg/kg/day to 30.5 mg/kg/day, and it was administered in 3 divided dosages. Clinical efficacy rates were as follows; 6/7 in acute bronchitis, 5/5 in pharyngotonsillitis, 3/3 in acute otitis media and 2/2 in cystitis and 3/3 in impetigo contagiosa. The overall rate was 95.0% (19/20). Bacteriologically, eradications were obtained with 1/2 strains of Streptococcus pyogenes, 3/3 of Staphylococcus aureus, 1/1 of Haemophilus influenzae, and each of Staphylococcus epidermidis, Haemophilus parainfluenzae, coagulase-negative staphylococci and Serratia marcescens. Diarrhea was observed in 1 patient. And elevated eosinophiles or GPT was observed in one patient each. In vivo pharmacokinetics of SY5555 was examined in 2 cases. Peak plasma levels were observed at 1 hour after dosage in one patient and at 2 hours in another upon oral administration of 8.3 mg/kg of SY5555, and peak levels were 2.44 and 1.38 micrograms/ml respectively. Half-lives of SY5555 were 1.39 and 0.59 hr. Concentrations of SY5555 in urine after administration were 70.2 (2-4 hrs.) to 91.0 (0-5 hrs.) micrograms/ml, respectively. SY5555 dry syrup is considered as an useful and safe antibiotic in treating the infectious diseases in children.

Effect of d-alpha-tocopherol analogues on lipoxygenase-dependent peroxidation of phospholipid-bile salt micelles

In order to know whether or not vitamin E acts as an effective antioxidant in lipoxygenase-dependent peroxidation of phospholipids, the effect of vitamin E and vitamin E analogues, 2,2,5,7,8-pentamethyl-6-hydroxychroman (PMC) and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox C), was investigated in enzymatic lipid peroxidation of bile salt micelles of pig liver phosphatidylcholine (PC) using soybean lipoxygenase. 15-Hydroperoxy-5,8,11,13-eicosatetraenoic acid was exclusively produced by the reaction with the PC molecular species containing arachidonic acid moiety, indicating that the hydroperoxidation of pig liver PC entirely progresses through the enzymatic reaction. PMC suppressed the accumulation of PC-hydroperoxides (PC-OOH) more efficiently than either d-alpha-tocopherol (alpha-Toc) or Trolox C, and 50% inhibition concentration by PMC was close to that of quercetin, a known lipoxygenase inhibitor from natural origin. The antioxidant activity of PMC was also superior to that of either alpha-Toc or Trolox C in ferrous ion-induced nonenzymatic oxidation of PC micelles in the presence of a trace amount of PC-OOH, although the radical-scavenging activities of these compounds in solution were similar or comparable to one another. In conclusion, PMC is more effective than alpha-Toc as an inhibitor of lipoxygenase reaction with phospholipids and of autoxidation in phospholipids. The phytyl chain of alpha-Toc seems to be unfavorable for exerting an inhibitory effect on lipoxygenase reaction with phospholipid-bile salt micelles.

[Clinical studies on cefozopran in pediatrics]

We conducted clinical studies on cefozopran (CZOP), a newly developed parenteral cephalosporin, for its clinical application in the field of pediatrics. 1. A clinical study was performed on 16 children with infections, including 9 with pneumonia, 1 each with acute bronchitis, enterocolitis, purulent lymphadenitis, 4 with skin and soft tissue infections. CZOP was administered by 30 minutes intravenous drip infusion. Doses varying from 20 to 35 mg/kg body weight were given t.i.d. Lengths of treatment ranged from 4 to 14 days. 2. Clinical efficacies were excellent in 10 and good in 6 cases, with an efficacy rate of 100%. The overall bacterial eradication rate for the pathogenic bacteria was also 100%. 3. Side effect was noted in 1 case with skin rash. Abnormal laboratory test data were found in 5 cases including slight elevations of GPT in 4 cases and GOT in 2 cases.

Enzymatic formation of 9-cis, 13-cis, and all-trans retinals from isomers of beta-carotene

9-cis Retinoic acid is a highly preferred ligand for the nuclear retinoic acid receptor RXR. Although 9-cis retinoic acid can be formed from all-trans retinoic acid in vivo and in vitro, the nature of the isomerization process has not been defined. 9-cis-Retinoic acid might also be formed biologically from 9-cis beta-carotene, an isomer of beta-carotene commonly found in foods. We have observed that enzyme preparations of rat liver and intestine convert highly purified 9-cis beta-carotene (99.8%) to a mixture of 9-cis, all-trans, and 13-cis retinals. Highly purified all-trans beta-carotene (99.7%) and 13-cis beta-carotene (99%) are primarily converted to all-trans retinal. Several aldehyde dehydrogenases in tissues can convert retinal to retinoic acid. Although the rates of cleavage of 9-cis and 13-cis beta-carotenes are slower than that of the all-trans isomer, the oxidative conversion of 9-cis beta-carotene to 9-cis and all-trans retinals is the first identified enzymatic reaction for the formation of 9-cis retinal in animal tissues.

Synthesis of a phosphatidyl derivative of vitamin E and its antioxidant activity in phospholipid bilayers

A novel phospholipid containing a chromanol structure at its polar head group was synthesized from egg yolk phosphatidylcholine and 2,5,7,8-tetramethyl-6-hydroxy-2-(hydroxyethyl)chroman by transphosphatidylation catalyzed by phospholipase D from Streptomyces lydicus. The structure of the product synthesized was shown by spectral analysis to be 1,2-diacyl-sn-glycero-3-phospho-2'-hydroxyethyl- 2',5',7',8'-tetramethyl-6'-hydroxychroman. The phosphatidylchromanol (PCh) showed antioxidant activity against radical chain oxidation of methyl linoleate in solution in a manner similar to that of d-alpha-tocopherol (alpha-Toc) and 2,2,5,7,8-pentamethyl-6-chromanol. However, PCh was less effective as a chain-breaking antioxidant than was alpha-Toc when unilamellar egg yolk phosphatidylcholine liposomes were exposed to either a water-soluble or a lipid-soluble radical initiator. It is likely that the phospholipid nature of PCh affects the location and the mobility of the chromanol moiety in the membrane bilayer resulting in a decrease in antioxidant activity. On the other hand, the antioxidant activity of PCh was little different from that of alpha-Toc in unilamellar liposomes when exposed to a lipid-soluble radical initiator in the presence of ascorbic acid. It appears that PCh in phospholipid bilayers can be regenerated by ascorbic acid in aqueous phase as can be alpha-Toc. The new phospholipid, phosphatidylchromanol, should prove useful as a chain-breaking antioxidant in phospholipid membranes.

Reduction of fatty acid hydroperoxides by human parotid saliva

Arachidonic acid hydroperoxide (15-hydroperoxyeicosatetraenoic acid; 15-HPETE) was introduced into human parotid saliva and incubated at 37 degrees C. Straight phase high-performance liquid chromatography analysis of the reaction mixture showed that 15-HPETE was detoxified to its reduced form, 15-hydroxyeicosatetraenoic acid, in the presence of glutathione. Therefore, it is concluded that human parotid saliva possesses fatty acid hydroperoxide-reducing ability. However, its effectiveness was found to be lower than that of blood plasma.

Antioxidant activity of xanthophylls on peroxyl radical-mediated phospholipid peroxidation

The ability of xanthophylls (canthaxanthin, zeaxanthin, and astaxanthin) as chain-breaking antioxidants was investigated in peroxyl radical-mediated peroxidation of phosphatidylcholine (PC) liposomes under atmospheric conditions using lipid-soluble and water-soluble radical generators. These xanthophylls retarded the chain propagation reaction of phosphatidylcholine hydroperoxides (PC-OOH) formation, although their activities to trap chain-carrying peroxyl radical were much less than that of alpha-tocopherol. In chick plasma studies, it was observed that endogenious xanthophylls participated in the antioxidant defenses against the attack of aqueous peroxyl radical. It was concluded that xanthophylls possess the ability to act as chain-breaking antioxidants in the peroxidation of membraneous phospholipids. Dietary xanthophylls may, therefore, be helpful in resisting membraneous phospholipids against oxidative damage in vivo.

Effect of lard, palm and rapeseed oils life conservation in aged mice

Effects of lard, palm and rapeseed oil diets on the survival and fatty acid composition of liver and brain lipids were studied in male and female mice for 15 months. Over 80% of mice fed on lard and rapeseed oil (n-3 PUFA sufficient) diets survived to the end of feeding trial, however, 60% of male mice fed on palm oil (n-3 PUFA deficient) diet died before the end. Although a survival curve in female mice fed on palm oil diet was similar to that in male, it was not as dramatic as that of the male. The fatty acid analyses revealed that severe n-3 PUFA deficiency occurred in the mice fed on a palm oil diet. Moreover, the fatty acid was more deficient in the male than in the female. These results suggest that short life in mice may be caused by n-3 PUFA deficiency and, therefore, the fatty acid may be essential in enjoying a long life.

Synthesis of 6-phosphatidyl-L-ascorbic acid by phospholipase D

Phospholipase D (EC 3.1.4.4) of Streptomyces species was found to catalyze transphosphatidylation to L-ascorbic acid from phosphatidylcholine (PC) in a biphasic reaction system. The product was identified as 1,2-diacyl-sn-glycero-3-phospho-6'-L-ascorbic acid (PA-AsA) by mass spectrometry and nuclear magnetic resonance spectroscopy. The optimal pH of transphosphatidylation was 4.5 and the rate of PA-AsA formation increased as concentrations of L-ascorbic acid increased. The conversion of PC to PA-AsA was greater than 80%. PA-AsA was found to be more resistant to hydrolysis by phospholipase D than was PC.

Antioxidant activity of 6-phosphatidyl-L-ascorbic acid

The antioxidant activity of 6-phosphatidyl-L-ascorbic acid was investigated in a homogeneous solution and a liposomal suspension. In an apolar solvent, one molecule of 6-phosphatidyl-L-ascorbic acid could trap one peroxyl radical. When 6-phosphatidyl-L-ascorbic acid was included in multilamellar liposomes of egg yolk phosphatidylcholine, it could retard more effectively the aqueous peroxyl-induced peroxidation of phosphatidylcholine than L-ascorbic acid.

Effects of SGB-1534, a new synthesized phenylpiperazine derivative, on blood pressure and heart rate in stroke-prone spontaneously hypertensive rats

The present study was undertaken to elucidate the effects of a new synthesized phenylpiperazine derivative SGB-1534 on mean arterial blood pressure and heart rate in stroke-prone spontaneously hypertensive rats(SHRSP). SGB-1534 (0.05 and 0.5 mg/kg, i.v.) produced a significantly greater decrease in mean arterial blood pressure in SHRSP than in normotensive Wistar Kyoto rats(WKY). Heart rate also tended to decrease in parallel with the decrease in mean arterial blood pressure in SHRSP. In this study, it was revealed that SGB-1534 has an antihypertensive effect in SHRSP. An attempt was made to elucidate the hypotensive mechanism of SGB-1534 using WKY. SGB-1534 (0.5 mg/kg, i.v.) significantly inhibited pressor responses to norepinephrine (5 micrograms/kg, i.v.) and methoxamine (50 micrograms/kg, i.v.). SGB-1534 (0.5 mg/kg, i.v.) did not affect the preganglionic sympathetic adrenal nerve activity. The present findings suggest that the action site of SGB-1534 is not in the central nervous system, but in the peripheral alpha 1-adrenoceptors in rats.