Recent work with approaches like recombinant mutants and X-ray crystallography has given much new information about the ligand-binding properties of human serum albumin (HSA). The information increases the understanding of this unique transport and depot protein and could give a structural basis for the possible construction of therapeutic agents with altered HSA-binding properties. A tabulation of high-affinity binding sites for both endogenous and exogenous compounds has been made; it could be useful for the above-mentioned purpose, but it could also be of value when trying to predict potential drug interactions at the protein-binding level. Drug displacement is not always a complication to therapy; it can be used to increase the biological effect of a drug. However, due to rebinding at other sites, the increase in the free concentration of a displaced ligand can be less than expected. Drugs and drug metabolites can also interact covalently with HSA; thiol-containing drugs often bind to the single free cysteine residue of HSA, and glucuronidated drugs react irreversibly with other residues of the protein. Reversible binding of ligands is often stereospecific, and therefore immobilized HSA can be used to separate drug isomers. Albumin-containing dialysates are useful for extracorporeal removal of endogenous toxins and in the treatment of drug overdoses. HSA has different types of hydrolytic activities, which also can be stereospecific. The esterase-like property seems especially useful in converting prodrugs to active drugs in plasma.
A cDNA encoding rat homologue of the previously characterized mouse Sox6 was isolated by a polymerase chain reaction (PCR) cloning strategy. Comparison of this cDNA with homologous mouse, human and rainbow trout cDNA exhibited an overall amino acid sequence identity of 99.6, 89.3 and 76.3% respectively. The leucine-zipper and HMG-box motif were almost completely conserved between these homologues. The expression of Sox6 was determined in rat by Northern hybridization and Real-time quantitative reverse transcription (RT)-PCR. rSox6 (rat Sox6) was specifically expressed in the neonatal brain and adult testis with Northern blotting. Real-time quantitative RT-PCR for the determination of Sox6 mRNA was examined. The rSox6 was expressed in the neonatal brain and adult testis as well as by Northern blotting and also expressed in the adult eyeball and slightly in the ovary.
Arachidonic acid cascade inhibitors, including phospholipase A2 inhibitors, dexamethasone and quinacrine (mepacrine), cyclooxygenase inhibitors, indomethacin and aspirin, and lipoxygenase inhibitor AA861, prevented foam cell formation and cholesterol accumulation in the incubation of thioglycollate-induced mouse peritoneal macrophages with oxidized low density lipoprotein (LDL) at 37 °C for 24 h. These inhibitors similarly prevented foam cell formation of fibronectin- and Ca ionophore A23187-stimulated macrophages. Binding and/or uptake of DiI (1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine)-acetyl LDL by macrophages at 37 °C for 3 h and arachidonic acid release from macrophages at 37 °C for 4 h were inhibited by dexamethasone. Exogenously added phospholipase A2 of bee venom and Crotalus adamanteous venom increased arachidonic acid release during incubation for 2 h, and increased macrophage binding and/or uptake of DiI-acetyl LDL at 37 °C for 3 h, and foam cell formation at 37 °C for 24 h. Protein kinase inhibitors, ML-9 and staurosporine, that inhibited macrophage binding and/or uptake of DiI-acetyl LDL did not inhibit arachidonic acid release, indicating that protein phosphorylation was not involved in the arachidonic acid pathway in the macrophage scavenger receptor activation. Nordihydroguaiaretic acid that inhibited arachidonic acid release prevented binding and/or uptake of DiI-acetyl LDL. The release of arachidonic acid was not enhanced by fibronectin-stimulation, indicating that Ca influx-dependent stimulation of macrophage activity was not through the activation of phospholipase A2. These results indicate that, as well as the fibronectin-stimulated Ca influx pathway and protein phosphorylation pathway, the arachidonic acid pathway participated in the activation of macrophages to bind and take up oxidized LDL.
We have previously shown that Txk, a member of Tec family tyrosine kinase, is expressed in Th1 and Th0 cells and directly contributes to gene transcription of Th1-related proteins, including interferon (IFN)-γ, through nuclear translocation in response to mitogenic stimuli. Btk, another member of Tec family tyrosine kinase, has been shown to have a Src family tyrosine kinase-dependent transphosphorylation site and an autophosphorylation site. However, little is known about the phosphorylation mechanism of Txk, except that 420 tyrosine residue was identified as the transphosphorylation site. In this study, we found that Txk autophosphorylated itself by using an in vitro kinase assay. To elucidate the role of phosphorylation in Txk function, we studied IFN-γ secretion by Jurkat T cells expressing mutant Txk proteins. While transfection with the wild-type Txk resulted in increased IFN-γ production, the function was abrogated by disruption of the ATP biding site, which is presumably involved in the autophosphorylation mechanism. The results suggest that phosphorylated Txk is an active form to promote IFN-γ synthesis. The 91 tyrosine residue of Txk is deduced to be an autophosphorylation site by comparing its structure with Btk. In Jurkat cells transfected with Txk Y91A, IFN-γ production was decreased in comparison with the wild-type Txk transfected Jurkat cells. These data suggest that phosphorylation of the 91 tyrosine residue in Txk plays a positive regulatory role in Txk function.
The sialic acid binding lectin from bullfrog oocytes (cSBL) is known to have anti-tumor activity. In a previous report, to elucidate the relationship between the net charge and anti-tumor activity of cSBL, we examined the effect of chemical modifications of cSBL with a water-soluble carbodiimide in the presence of various nucleophiles. The results suggested that the anti-tumor activity and internalization into tumor cells increased with an increase in the net charge of cSBL. However, in the chemically modified cSBL, a modification site was observed on average in two of the carboxyl groups of cSBL. To confirm these previous results and to determine which modified carboxyl group contributes to the increase in anti-tumor activity, we prepared mutants with substitutions of Asn/Gln and Arg at three acidic amino acid residues of cSBL and studied their anti-tumor activity and internalization efficiency. The results showed the enhancing effect of charge on anti-tumor activity and internalization, and suggested that the replacement of D24 and E88 of cSBL with arginine is more effective than that of E97. The double mutant D24RE88R showed comparable anti-tumor activity to the ethylenediamine-modified cSBL reported previously. The mutant was well-characterized as a pure cSBL derivative suitable for studying the mechanism of the anti-tumor action of cSBL.
Human glioblastoma cell line T98G produced a cellular form of prion protein (PrPC), and we confirmed expression of PrP mRNA by RT-PCR. Immunoblot analysis of whole cell lysate revealed one major (35 kDa) and two faint bands (31, 25 kDa) that reacted with monoclonal anti-human PrP antibody 3F4. Cells treated with tunicamycin produced only a 25 kDa band, representing a deglycosylated form of PrP. Similarly, peptide: N-glycosidase F treatment of whole cell lysate altered the Asn-linked form to the deglycosylated form. When T98G cells were cultured for a longer period, the amount of PrPC per cell increased on Day 4 to 16 in a time-dependent manner. When the cells were cultured at high cell-density, the cells on Day 4 produced the same amount of PrPC as those on Day 16 of the usual culture. Moreover, in a serum-free medium, cells cultured at a low cell-density produced the same amount of PrPC as those cultured at the high cell-density. These results demonstrate that PrPC production in T98G cells was dependent on the phase of the cell cycle, probably the G1 phase.
We previously reported that the lower activity of mevalonate pyrophosphate decarboxylase (MPD) was caused by the reduced amount of this enzyme in stroke-prone spontaneously hypertensive rat (SHRSP) by immunoblot analysis using 20000×g supernatant containing cytosol and microsomes. A recent study showed that at least three different subcellular compartments, including peroxisomes, are involved in cholesterol synthesis. In this study, we examined the subcellular distribution of 45- and 37-kDa MPD in the liver of SHRSP and compared normotensive Wistar Kyoto rat (WKY) and SHRSP. 45-kDa MPD was detected in the cytosol and peroxisomes of SHRSP, while 37-kDa MPD was detected in the cytosol of SHRSP, but not in the peroxisomes. The relative enrichment of 45-kDa MPD in peroxisomes was lower than that of LDH, suggesting the possibility that 45-kDa MPD of SHRSP did not exist in the peroxisomes. Also, 45-kDa MPD was decreased in the crude extract containing 1% Triton X-100, cytosol and peroxisomes of SHRSP, and 37-kDa MPD was decreased in the crude extract containing 1% Triton X-100 and cytosol of SHRSP, as compared with WKY. These data indicate that the cholesterol synthesis in the liver of SHRSP by the reduced amount of MPD is significantly reduced.
Oxidized low-density lipoprotein (Ox-LDL) plays an important role in the initiation and progression of atherosclerosis. Asp-hemolysin, a hemolytic toxin from Aspergillus fumigatus, is a specific, high affinity binding protein for Ox-LDL. We have previously shown that Ox-LDL strongly inhibits the hemolytic activity of Asp-hemolysin, and that the removal of lysophosphatidylcholine (lysoPC) from Ox-LDL abolished the inhibition. In the present study, to clarify the binding mechanism of Asp-hemolysin to Ox-LDL, we investigated the interaction between Asp-hemolysin and lysoPC as a typical lipid moiety of Ox-LDL. Based on western blot analysis, the binding of Asp-hemolysin to LDL, oxidized for different times, depended on the lysoPC content in each Ox-LDL. In addition, the inhibition of lysoPC production in Ox-LDL by phenylmethylsulfonyl fluoride (PMSF) pretreatment of LDL resulted in a marked decrease of Asp-hemolysin binding to PMSF-pretreated Ox-LDL. Furthermore, the binding analysis of Asp-hemolysin to lysoPC using ion-exchange chromatography revealed that Asp-hemolysin directly binds to lysoPC.
The purpose of this study was to examine effects of osthole on postmenopausal osteoporosis using ovariectomized (OVX) rats. All of the rats were divided into sham and OVX groups. At 2 weeks post-operation, the sham-operated rats received solvent vehicle (97% corn oil and 3% ethanol, 1.0 ml/kg, subcutaneously); the OVX rats were divided into three groups which were treated with solvent vehicle (same the sham rats, 1.0 ml/kg, subcutaneously), 17β-estradiol (30 μg/kg, subcutaneously) or osthole (9.0 mg/kg, orally) 5 d/week for 4 weeks, respectively. In OVX rats, the increases of body weight, spleen and thymus weight were significantly decreased and the atrophy of uterus was preserved by 17β-estradiol treatment, but not by osthole. Treatment with either 17β-estradiol or osthole significantly protected cancellous bone loss owing to estrogen deficiency and significantly increased the maximal load in the femoral neck of OVX rats. In addition, the increases of serum osteocalcin (OC) and urinary deoxypyridinoline (DPD) levels caused by ovariectomy were all significantly suppressed by 17β-estradiol. However, only urinary DPD was significantly reduced by osthole and no change was found in serum OC. Our results demonstrate that osthole may be just as effective as 17β-estradiol in suppressing bone loss due to ovariectomy but osthole perhaps does not work through the estrogen pathway.
Syringaresinol isolated from Epimedium koreanum NAKAI and Magnolia officinalis REHD. et WILS. was subjected to optical resolution by chiral HPLC to give (+)- and (−)-enantiomers. The two syringaresinol enantiomers, as well as a mixture of their glucosides, showed dose-dependent neuritogenesis in a concentration range from 0.24 to 24 μM in PC12h cells.
The effects of ketoconazole (KCZ) on secretion of progesterone and cAMP in Leydig cells were investigated in vitro. MA-10 mouse Leydig tumor cells were used to conduct the experiments. KCZ significantly inhibited the progesterone production from MA-10 cells in a dose dependent fashion between 2 and 20 μM among 1, 2 and 3 h of incubation. There was a statistically significant difference in luteinizing hormone (LH) stimulated progesterone production inhibited by 2 and 20 μM KCZ treatment compared to the control. The effect of KCZ on progesterone biosynthesis in MA-10 cells was mediated by cAMP, since KCZ suppressed basal and LH stimulated cAMP production and content within the same dose range. The stimulatory effects of forskolin and sodium fluoride on the adenylate cyclase system were also inhibited by KCZ. Moreover, dibutyryl cAMP blocked the inhibitory effect on steroidogenesis of KCZ in MA-10 cells. These data indicated that KCZ induced the inhibition of a catalytic component of adenylate cyclase holoenzyme in MA-10 mouse Leydig tumor cells.
In the present study, a series of 2-substituted-4-methyl-7-amino/4,7-dimethyl-1,8-naphthyridines were synthesized and characterized by IR, 1H-NMR and elemental analysis. The compounds were investigated for anticonvulsant (125, 250 mg/kg), cardiac and antimicrobial activities. The compounds were screened for antibacterial activity against gram (+) bacteria (Staphylococcus epidermidis, Bacillus subtilis, Enterococcus faecalis and Micrococcus luteus) and gram (−) bacteria (Proteus vulgaris, Pseudomonas aeruginosa, Escherichia coli and Salmonella typhi). All the compounds except 2-(3′-phenylaminopropyloxy)-4-methyl-7-amino-1,8-naphthyridine exhibited significant anticonvulsant activity. The anticonvulsant activity of 2-(3-morpholino-2′-hydroxypropyloxy)-4-methyl-7-amino-1,8-naphthyridine, 2-(3′-diphenylamino-2′-hydroxypropyloxy)-4-methyl-7-amino-1,8-naphthyridine and 2-(3′-diethanolamino-propyloxy)-4,7-dimethy-1,8-naphthyridine at the dose of 250 mg/kg were found to be equivalent to diazepam (5 mg/kg). Sympathetic blocking activity was observed with 2-(3′-phenylamino-2′-hydroxypropyloxy)-4-methyl-7-amino-1,8-naphthyridine, 2-(3′-diethanolamino-2′-hydroxypropyloxy)-4-methyl-7-amino-1,8-naphthyridine and 2-(3′-diphenylamino-2′-hydroxypropyloxy)-4-methyl-7-amino-1,8-naphthyridine only. All the compounds were devoid of antibacterial activity against the tested bacteria.
We examined whether slight oxidative stress and/or damage in cells could be amplified by subsequent ionizing irradiation and thus become detectable as obvious chromosomal damage. WIL2-NS cells, a human B lymphoblastoid cell line, were pretreated with an oxidant and then exposed to X-rays at 0.25 or 0.5 Gy. The chromosomal damage in the cells was evaluated by cytokinesis-block micronucleus (CBMN) assay. Pretreatment with a superoxide-generating system (hypoxanthine (HX)/xanthine oxidase (XO), 1 and 2 mU/ml of XO), tert-butyl hydroperoxide (t-BuOOH, 10 and 100 μM) or H2O2 (5 μM) alone did not induce significant chromosomal damage, but the oxidant-induced damage increased significantly with subsequent irradiation. The tested dose of these oxidants did not induce significant changes in cell viability, the nuclear division index, and the concentration of antioxidants, indicating that only weak oxidative stress was introduced into the cells. These results suggest that low-dose oxidant-induced chromosomal damage becomes detectable as obvious chromosomal damage with subsequent ionizing irradiation in vitro.
When ginsenoside Rc was anaerobically incubated with human fecal microflora, all specimens metabolized ginsenoside Rc to compound K and protopanaxadiol. The main metabolite was compound K. Among the bacteria isolated from human fecal microflora, most bacteria, such as Bacteroides sp., Eubacterium sp., and Bifidobacterium sp. potently transformed ginsenoside Rc to compound K. Bifidobacterium K-103 and Eubacterium A-44 transformed it to compound K via ginsenoside Rd, and Bacteroides HJ-15 and Bifidobacterium K-506 metabolized to compound K via ginsenoside Mb, which was isolated as a new metabolite (M.W. 940[+Na]). Among ginsenoside Rc and its metabolites, compound K exhibited the most potent antiallergic activity on the IgE-induced RBL cell line as well as potent cytotoxic activity against tumor cell lines.
The origin of the antioxidant activity of Luobuma aqueous extract was examined by measuring the peroxynitrite (ONOO−)-eliminating activities of fractions of this extract obtained by Sephadex LH-20 column chromatography. Three of the four fractions obtained, i.e., those excluding the H2O-eluted fraction, were found to possess ONOO−-eliminating activity. These three fractions were combined and fractionated again by Sephadex LH-20 column chromatography, which yielded five fractions. Seven different compounds were isolated from two of these five fractions with high activity. Epigallocatechin-(4β-8)-epicatechin showed the highest ONOO−-eliminating activity.
Methanol, methanol–water (1 : 1) and water extracts were prepared from seventy-seven Vietnamese medicinal plants and tested for their antiproliferative activities against human HT-1080 fibrosarcoma cells. Among them, fifteen extracts including seven methanol extracts of Caesalpinia sappan, Catharanthus roseus, Coscinium fenestratum, Eurycoma longifolia, Hydnophytum formicarum and Streptocaulon juventas (collected at two areas), six methanol–water (1 : 1) extracts of Cae. sappan, Cat. roseus, Co. fenestratum, H. formicarum and S. juventas (at two areas), and two water extracts of Cae. sappan and S. juventas exhibited antiproliferative activities in a concentration-dependent manner. Their antiproliferative activities against human cervix HeLa adenocarcinoma, human lung A549 adenocarcinoma, murine colon 26-L5 carcinoma, murine Lewis lung carcinoma (LLC) and murine B16-BL6 melanoma cells were then examined. Co. fenestratum showed selective activity against lung carcinoma and/or lung metastatic cell lines, A549, LLC and B16-BL6, while H. formicarum and S. juventas showed selective activity against human tumor cell lines, HeLa and A549. Characteristic morphological change and DNA fragmentation indicated the antiproliferative activity to be due to the induction of apoptosis.
A tyrosinase inhibitor was isolated from the peel of Citrus fruit by activity-guided fractionation, and identified as 3′,4′,5,6,7,8-hexamethoxyflavone (nobiletin) by comparison with reported spectral data. Nobiletin (IC50 of; 46.2 μM) exhibited more potency than Kojic acid (IC50; 77.4 μM) used as a positive control, and it was found to be potentially an effective inhibitor of the production of melanin.
Anti-allergic effects (types I and IV) of the 70% ethanol extract (CM-ext) obtained from Cnidii Monnieri Fructus (dried fruits of Cnidium monnieri) were investigated on 48 h homologous passive cutaneous anaphylaxis (PCA), 2,4-dinitrofluorobenzene (DNFB)-induced contact dermatitis and picryl chloride (PC)-induced contact dermatitis in experimental animals. CM-ext showed inhibitory effects on these allergic models. Osthol isolated from CM-ext also had the inhibitory effects. These results suggested that Cnidii Monnieri Fructus might be useful as an agent for allergic diseases and that its anti-allergic effect was partially attributable to a coumarin derivative, osthol.
The effects of glutathione (GSH) and glutathionesulfonic acid sodium salt [N-(N-γ-L-glutamyl-L-β-sulfoalanyl)glycine sodium salt, GSO3Na], which is a minor metabolite of GSH, on the pharmacokinetics of thiopental sodium were investigated in rats. The concomitant use of GSO3Na with thiopental sodium significantly increased the tissue-to-plasma concentration ratio (Kp) of thiopental sodium 60 min after its administration in the heart, lung, brain, liver, kidney, and spleen, while GSH did not affect them. On the other hand, the Kp value of thiopental sodium 5 min after its administration with concomitant GSO3Na decreased significantly only in the spleen. Neither GSO3Na nor GSH changes the pharmacokinetic parameters of thiopental sodium. Significant change of the binding ratio of thiopental sodium to bovine serum albumin (BSA) was not observed by the addition of less than 5-fold GSO3Na. About 50% of thiopental sodium was bound to the brain, lung or liver, however, no significant change of this binding ratio was observed by the concomitant use of GSO3Na. The partition coefficient of thiopental sodium apparently increased by the concomitant use of GSO3Na but not by GSH. This phenomenon seemed to be concerned with a mechanism to increase the Kp values of thiopental sodium in the tissues. The increment in the drug distribution to tissues with concomitant GSO3Na observed in this study is useful information for the application of drug combinations as a biodistribution promoter.
The aim of this study was to examine the interaction of soybean-derived sterylglucoside (SG) with the human hepatoblastoma cell line HepG2 with regard to the penetration-enhancing effect of β-sitosterol glucoside (Sit-G) to clarify the accumulation of SG-containing liposomes (SG-liposomes) to the liver in vivo. The approach was based on measurement of the association of SG-liposomes labeled with 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI) in terms of asialoglycoprotein receptor (ASGP-R)-mediated endocytosis, affinity of Sit-G using IAsys and the association of FITC-dextran 4400 (FD-4) increased by Sit-G with the cells. The association of SG-liposomes was decreased by addition of asialofetuin, suggesting that SG-liposomes might be taken up via ASGP-R. Sit-G showed higher affinity with HepG2 cells than HeLa cells, and enhanced the association of FD-4 depending on the incubation time and Sit-G concentrations. Significant positive correlations were found between Sit-G and FD-4 association with the cells, indicating that Sit-G enhanced the drug penetration by distribution in cell membranes. The high degree of liver association of SG-liposomes in vivo might be related to recognition of glucose residues of SG by ASGP-R and to the high affinity and penetration-enhancing effect of Sit-G with hepatocytes.
The cytotoxic effects of 27 anticancer drugs including amrubicin, vinorelbine, paclitaxel, docetaxel, gemcitabine, and irinotecan were evaluated in human cervical carcinoma HeLa cells, and drug-resistant HeLa-derived Hvr1-1, Hvr10-6, and Hvr100-6 cells, which were newly established by stepwise exposure to vinblastine. FACS and RT-PCR analysis indicated that MDR1 (P-glycoprotein) was induced without any alterations in expression of its related transporters. Hvr100-6 cells showed 2- to 200-fold higher resistance to anthracyclines than HeLa cells, and unexpectedly showed slight resistance to idarubicin and amrubicin. The relative resistance to vinca-alkaloids was 300- to 600000-fold, and Hvr100-6 cells showed the highest relative resistance to vinorelbine. Hvr100-6 cells also showed 4000- and 60000-fold resistance to the taxanes paclitaxel and docetaxel, respectively. Hvr100-6 cells were also resistant to 6-mercaptopurine, actinomycin D, etoposide, and mitomycin C, with relative resistance of 8-, 45000-, 12-, and 9-fold, respectively. In contrast, Hvr100-6 cells showed no or slight resistance to platinum derivatives, pyrimidine analogues, and alkylating agents or to irinotecan and its active form, or tamoxifen. The cytotoxicity of anthracyclines, vinca-alkaloids, taxanes, actinomycin D, and etoposide was extensively reversed by cyclosporin A. Cyclosporin A had no effect on the cytotoxicity of 6-mercaptopurine or mitomycin C, suggesting that resistance to these drugs was not mediated via MDR1. The alterations in cytotoxicity by overexpression of MDR1 and effects of cyclosporin A could be also qualitatively explained by [3H]vinblastine uptake experiments. The 27 anticancer drugs analyzed here could be classified into substrates and nonsubstrates for MDR1. This will be useful for designing effective regimens for chemotherapy.
The objective of this study was to construct a modified equation for the delivery of a drug by iontophoresis. Indomethacin was selected as a model since it has been widely used as a non-steroidal anti-inflammatory drug (NSAID) for external pharmaceutical preparations. The experiments were performed under a constant current in vivo using rat abdominal skin, and the plasma concentration was monitored by HPLC. Pharmacokinetic parameters were obtained from the plasma concentration profiles after intravenous injection. A theoretical value of the transdermal delivery of drug by iontophoresis was calculated from the plasma concentration and pharmacokinetic parameters. The experimental value was evidently higher than the theoretical one, suggesting the enhancement of passive diffusion with an increase of applied current. The modified equation was proposed for the delivery of a drug by iontophoresis incorporating enhanced passive diffusion.
The present paper investigates the pharmacokinetics of propofol in the plasma of two elderly patients operated on under total intravenous anesthesia using propofol. A 78-year-old (patient A) and a 76-year-old (patient B), both Japanese men with unstable angina pectoris, were operated on for coronary artery bypass grafts. For the induction of anesthesia, 1.5 mg/kg propofol was administered as a single bolus infusion, and anesthesia was maintained using the step-down infusion regimens of propofol. Propofol concentration in the plasma was measured by HPLC with a fluorescence detector. The simulation curves, following the two-compartment model, fitted well to the profiles of the individual data of propofol concentrations in the plasma. When 4 mg/kg/h of propofol was administered to both patients while maintaining anesthesia, propofol concentrations in the plasma were maintained at over 1.0 μg/ml. In patient A, the propofol concentration in the plasma was 140 ng/ml at 6 h after the end of the infusion. In patient B, the propofol concentrations in the plasma were 73 ng/ml at 6 h and 35 ng/ml at 12 h after the end of the infusion. The apparent distribution volumes of patients A and B were 1.43 and 1.62 l/kg, respectively. The half-lives of propofol in the plasma of patients A and B were estimated to be 13.3 and 17.4 min as the α phase, and 10.1 and 10.5 h as the β phase, respectively. In elderly patients with cardiac surgery, the maintenance concentrations of propofol in the plasma were enough to maintain a concentration of 1.0 μg/ml, and the half-life may be longer than previously reported values in adult patients.
To enhance the therapeutic efficacy as well as to reduce the side effect, we attempted to liposomalize 4β-aminoalkyl-4′-O-demethyl-4-desoxypodophyllotoxin (TOP-53), a novel and effective topoisomerase II inhibitor. More than 90% of TOP-53 was efficiently incorporated into the liposomes composed of dipalmitoylphosphatidylcholine and cholesterol by remote-loading method. Anti-tumor activity of liposomal TOP-53 against solid tumor was examined in vivo using colon26 NL-17 carcinoma model mice. Three doses of liposomal TOP-53 (12 mg/kg/dose) showed significant tumor growth suppression (97.5% reduction determined at day 25) and the increase in life span (33%) of tumor-bearing mice. Furthermore, one mouse out of 5 was completely cured after treatment. Since similar efficacy was observed in the free TOP-53 treated group, liposomalization does not contribute much to the enhancement of therapeutic efficacy. However, a slight but measurable damage at the injection site was observed when free TOP-53 was injected, and the damage was diminished by the liposomalization. Taken together, liposomalization reduces the side effect rather than enhancing the therapeutic efficacy when TOP-53 is used.
We have previously shown that the combination of β-glucan and nonsteroidal anti-inflammatory drugs (NSAIDs) was lethal to mice. In this study, we examined the effect of Candida on this treatment and found that Candida showed similar lethal toxicity when used in combination with indomethacin. It was also confirmed that LPS preparations from various origins and by various procedures did not show lethality. Candida/indomethacin induced lethality was found to be associated with increased number of leukocytes in various organs and activation of these cells. These findings strongly suggest that pathogenic fungi augment the side effects of non-steroidal anti-inflammatory drugs.