Clarification of the Mechanism of Inhibiting the Maillard Reaction between Phosphatidylethanolamine and Sugars by Adding Fatty Acid Calcium Salts

Lecithin is known to undergo heat induced deterioration by the Maillard reaction between 1 mol of any sugar, except 2-deoxy sugar, and 2 mol of phosphatidylethanolamine (PE). However, we have previously reported that adding fatty acid metal salts can inhibit heat deterioration of soybean lecithin (SL). To clarify the mechanism of inhibition, 1,2-di-O-stearoyl-sn-glycero-3-phosphatidylethanolamine (DSPE), d-glucose, and calcium stearate or calcium decanoate were heated in octane. When DSPE and d-glucose with calcium stearate or calcium decanoate were heated in the octane, the heat deterioration of DSPE was significantly inhibited, and no increase in UV absorption at 350 nm was observed. From these reactant solutions, one compound having a phosphate group and no primary amine was isolated, and NMR spectra confirmed that two molar of stearic acid derived from DSPE were coordinated to the amino group and phosphate group of DSPE. Therefore, we concluded that adding fatty acid metal salts reduced the nucleophilic reactivity of the amino group of PE and inhibited the Maillard reaction with sugars because two molar of fatty acid derived from PE coordinated to the amino group and phosphate group of PE.

Use of Fatty Acid Metal Salts for Preventing Maillard Reaction-Driven Browning of Lecithins

We previously reported that fluid soybean lecithin (SL) undergoes heat deterioration by the newly reported pseudo-Maillard rearrangement reaction. To inhibit heat deterioration, SLs were treated with metal silicates, such as magnesium silicate and calcium silicate. When soybean fatty acid was added to SL before treatment with calcium silicate, the color index after heating improved significantly as the acid value increased from 10 to 35 mg KOH/g. To elucidate the role of soybean fatty acid, calcium silicate treatment was carried out by adding several fatty acids to SL. Although saturated fatty acids had no effect on the heat deterioration of SL, unsaturated fatty acids were significantly more effective at inhibiting heat deterioration. Furthermore, for unsaturated fatty acids, it was confirmed that the calcium concentration increased in SL. Based on these results, several fatty acid metal salts were added to confirm whether heat deterioration while heating SL could be inhibited. It was observed that the heat deterioration of SL could be inhibited with fatty acid metal salts, regardless of whether the fatty acids were saturated or unsaturated and whether the metal was monovalent, divalent, or trivalent. Therefore, in this study, we clarified that the heat deterioration of SL could be inhibited by adding fatty acid metal salts to SL. Among sodium stearate, calcium stearate, magnesium stearate, barium stearate, and aluminum tristearate, the divalent fatty acid metal salts had a stronger inhibitory effect on heat deterioration than the monovalent and trivalent salts.

Hemophilia B with Mutations at Glycine-48 of Factor IX Exhibited Delayed Activation by the Factor VIIa-tissue Factor Complex

Gly-48 is in the conserved DGDQC sequence (residues 47-51 of human factor IX) of the first EGF (EGF-1)-like domain of factor IX. The importance of the Gly-48 is manifested by two hemophilia B patients; factor IXTainan and factor IX>Malmö27, with Gly-48 replaced by arginine (designated IXG48R) and valine (IXG48V), respectively. Both patients were CRM+ exhibiting mild hemophilic episodes with 25% (former) and 19% (latter) normal clotting activities. We characterize both factor IX variants to show the roles of Gly-48 and the conservation of the DGDQC sequence in factor IX. Purified plasma and recombinant factor IX variants exhibited approximately 26%–27% normal factor IX’s clotting activities with G48R or G48V mutation. Both variants depicted normal quenching of the intrinsic fluorescence by increasing concentrations of calcium ions and Tb3+, indicating that arginine and valine substitution for Gly-48 did not perturb the calcium site in the EGF-1 domain. Activation of both mutants by factor XIa appeared normal. The reduced clotting activity of factors IXG48R and IXG48V was attributed to the failure of both mutants to cleavage factor X; in the presence of only phospholipids and calcium ions, both mutants showed a 4∼7-fold elevation in K m, and by adding factor VIIIa to the system, although factor VIIIa potentiated the activation of factor X by the mutants factor IXaG48R and factor IXaG48V, a 2∼3-fold decrease in the catalytic function was observed with the mutant factor IXa’s, despite that they bound factor VIIIa on the phospholipid vesicles with only slightly reduced affinity when compared to wild-type factor IXa. The apparent K d for factor VIIIa binding was 0.83 nM for normal factor IXa, 1.74 nM for IXaG48R and 1.4 nM for IXaG48V. Strikingly, when interaction with the factor VIIa-TF complex was examined, both mutations were barely activated by the VIIa-TF complex and they also showed abnormal interaction with VIIa-TF in bovine thromboplastinbased PT assays. Taken together, our results suggest that mutations at Gly-48 altered the interaction of factor IX with its extrinsic pathway activator (VIIa-TF complex), its macromolecular substrate (factor X), and its cofactor (factor VIIIa).

X-ray topography and EBIC studies of misfit dislocations in strained layer structures

X-ray topography(XRT) and EBIC have been used to study the generation of misfit dislocations in strained layer structures. Two structures studied were GaAs1−yPy(y=0.15) film and SLS consisting of InxGa1−xAs(x=0.08) and GaAs1−y Py(y=0.16) layers. XRT and EBIC techniques gave consistent results for the behavior of dislocations. The value of the critical thickness for generation of misfit dislocations in the former was found to be few times larger than that in the latter. EBIC image showed that a SLS lattice matched to the substrate is effective in reducing defects originating from the substrate.

Generation of a novel factor IX with augmented clotting activities in vitro and in vivo

BACKGROUND

Hemophilia B is an X-linked inherited disorder caused by the lack of functional factor IX (FIX). Currently, treatment of hemophilia B is performed by intravenous infusion of plasma-derived or recombinant FIX.

OBJECTIVE

In an effort to reduce factor usage and cost, we investigated the potential use of FIX variants with enhanced specific clotting activity.

METHODS

Seven recombinant FIX variants using alanine replacement were generated and assayed for their activity in vitro and in vivo.

RESULTS

One variant containing three substitutions (V86A/E277A/R338A, FIX-Triple) exhibited 13-fold higher specific clotting activity and a 10-fold increased affinity for human FVIIIa compared with FIX-wild-type (FIX-WT) and was thus investigated systematically in vivo. Liver-specific FIX-Triple gene expression following hydrodynamic plasmid delivery revealed a 3.5-fold higher specific clotting activity compared with FIX-WT. Human FIX-Triple and FIX-WT knock-in mice were generated and it was confirmed that FIX-Triple has 7-fold higher specific clotting activity than FIX-WT under normal physiological conditions. Protein infusion of FIX-Triple into hemophilia B mice resulted in greater improvement of hemostasis than that achieved with FIX-WT. Moreover, tail-vein administration of a serotype 8 recombinant Adeno-associated vector (AAV8) expressing either FIX-WT or FIX-Triple in hemophilia B mice demonstrated a 7-fold higher specific clotting activity of FIX-Triple than FIX-WT.

CONCLUSIONS

Our results indicate that the FIX-Triple variant exhibits significantly enhanced clotting activity relative to FIX-WT due to tighter binding to FVIIIa, as demonstrated both in vitro and in vivo. Therefore, FIX-Triple is a good candidate for further evaluation in protein replacement therapy as well as gene-based therapeutic strategies.

Heat deterioration of phospholipids. VI. Clarification of mechanism for the new pseudo Maillard rearrangement reaction by using 2-aminoethyl dihydrogenphosphate

2,3-Dihydro-1H-imidazo[1,2-a]pyridine-4-ylium derivatives with UV absorption at 350 nm were formed by reaction of one molar of any sugar except 2-deoxysugars with two molar of phosphatidylethanolamines involving a new pseudo Maillard rearrangement reaction. To elucidate the reaction mechanism, 2-aminoethyl dihydrogenphosphate, which had a partially similar structural moiety to PE, was reacted with D-galactose. Though the UV absorption at 365 nm was not observed and the four pyridinium derivatives were also not formed in the reactant solution, the UV absorption at 286 nm and browning of the reactant solution were observed. From this reactant solution, two compounds with lambdamax at 283 nm and 297 nm were isolated and former was determined as 5-(hydroxymethyl)furfural (HMF) and later did as phosphoric acid mono{2-[2-formyl-5-(hydroxymethyl)-1H-pyrrol-1-yl]ethyl}ester (PMPEE), which is a new compound, respectively. Because reaction of PMPEE with PE leads to form the pyridinium derivatives, we concluded that a compound like PMPEE was one of intermediates in this new reaction.

Heat deterioration of phospholipids. V. A new rearrangement reaction of sugars and phosphatidylethanolamine

Novel four 2,3-dihydro-1H-imidazo[1,2-a]pyridine-4-ylium derivatives were obtained with increase of UV absorption at 350 nm and browning of the solution by heating paste lecithin from soybean (SL) in octane. These four derivatives were formed by reaction of one molar of any sugar except 2-deoxysugars with two molar of phosphatidylethanolamines (PE) in SL. To confirm the reaction mechanism, several (13)C-labeled-sugars were reacted with 1,2-di-O-stearoyl-sn-glycero-3-phosphatidylethanolamine (DSPE), respectively. These reactants clearly showed that five carbons of the pyridinium ring and one carbon of the substituted group were based on those of a sugar and that the formation of the pyridinium derivatives was accompanied with cleaving between the carbons of 1- and 2-positions in the sugar and rearrangement. This reaction is a new rearrangement reaction and we named it "new pseudo Maillard rearrangement reaction".

Lung adenocarcinoma with a micropapillary pattern: a clinicopathological study of 25 cases

Lung adenocarcinoma with a micropapillary pattern has recently been described, but its biological behavior is as yet uncertain. In this article we present a clinicopathological study of lung adenocarcinoma with micropapillary morphology. We selected 25 patients with lung adenocarcinoma with micropapillary morphology from the 2001-2004 pathology files (age range 54 to 81 years; mean 64.5 years). Micropapillary carcinoma is predominantly located at the periphery of the tumor nodule or mass and occurs irrespective of the subtype of the adenocarcinoma. A micropapillary component was seen against a mucinous background in three cases and microcalcifications resembling psammoma bodies were seen in one case. Four cases showed intensive invasive growth such as micropapillary adenocarcinoma of the breast and 21 showed alveolar type morphology with piling-up of the neoplastic cells with or without stromal invasion. Seven of twenty-three (30.4%) showed lymph node metastases at time of operation. Twelve of twenty-five (48%) showed pleural invasion. Regarding clinical outcome, 14 patients were alive without disease, 5 were alive with disease, and 5 died of the lung adenocarcinoma. No significant relationship was found between the extent of the micropapillary component and prognosis. However, the carcinoma seen in the five patients who died showed breast type histology with intensive invasive growth in three cases and alveolar type histology with intensive stromal invasion in two. Lung micropapillary carcinoma of breast type may behave more aggressively than the alveolar type.

Intracytoplasmic lumina in invasive micropapillary carcinoma of the lung

Micropapillary carcinoma of the lung is a rare neoplasm, and several reports on micropapillary carcinoma of the lung have been presented to date. We present a case of micropapillary carcinoma of the lung here. A 75-yr-old Japanese man received the medical checkup and his chest X-ray disclosed the abnormal shadow of the lower lobe of the left lung. The histological examination of resected lung and extirpated lymph node showed the finding of micropapillary carcinoma. Some neoplastic cells of primary site contained intracytoplasmic lumina positive for Alcian blue and PAS stains. Pleural effusion appeared 9-mo after the operation. The cytology of pleural effusion showed cohesive clusters of neoplastic cells consisting of 3-20 cells without fibrovascular core. Additionally, intracytoplasmic lumina were observed in some neoplastic cells. Finally, carcinoma cells with micropapillary morphology may possess the intracytoplasmic lumina in the cytoplasm of metastatic site as well as primary site.

[Subdiaphragmatic bronchogenic cyst in the left crus of diaphragm: report of a case]

A 39-year-old man who had a subdiaphragmatic bronchogenic cyst in the left crus of diaphragm received surgical treatment. The cyst was located in the retroperitoneum just below the diaphragm and was adhered to the left crus of diaphragm and unconnected with any other structures. The surgically resected cyst was 50 x 25 x 22 mm diameter and the wall was thin and contained white turbid mucus. Histologically, the cyst consisted of ciliated epithelium, mucus glands, smooth muscle, cartilage and this evidence established the final diagnosis of bronchogenic cyst. The post operative course was uneventful and the patient was discharged 10 days after operation. This is the 4th reported case of a subdiaphragmatic bronchogenic cyst in the Japanese literature.

[Three cases of emergency video-assisted thoracoscopic surgery for spontaneous hemopneumothorax]

We experienced 3 cases of video-assisted thoracoscopic surgery for spontaneous hemopneumothorax. All the patients had received emergent operations because of massive intrathoracic bleeding. At the operation, a 3 cm-minithoracotomy and 2 trocar ports were fashioned. In the head up position, massive blood clots in the apex in the thoracic cavity was removed by using grasping forceps and the source of bleeding point was detected easily. The bleeding was successfully stopped. It was difficult to remove massive blood clots from trocar port by suction, however it was easy to remove massive blood clots from a 3 cm-minithoracotomy window by using a large grasping forceps. Post operative course was satisfactory and the all patients discharged within 2 weeks after admission. We concluded that the spontaneous hemopneumothorax may be a good indication for video-assisted thoracoscopic surgery.

The distinct roles that Gln-192 and Glu-217 of factor IX play in selectivity for macromolecular substrates and inhibitors

In this paper, we report functional characterization of positions 192 and 217 (chymotrypsinogen numbering system) in human factor IX and discuss the distinction and similarity of these two sites among the blood coagulation factors. Recombinant factor IXQ192E (residue glutamine at position 192 replaced by glutamic acid), IXQ192K, IXE217D, and IXE217R proteins exhibited 11%, 46%, 39%, and 2% of the wild-type factor IX's clotting activity, respectively. Binding of these variants to factor VIIIa (FVIIIa) was inefficient compared to that of wild-type factor IX, and the dissociation constants doubled for IXQ192E, 3-fold higher for IXQ192K and 4-fold higher for both IXE217D and IXE217R. In the presence of FVIIIa, all variant factor IX hydrolyzed factor X at the catalytic efficiencies correlating with respective clotting activities. However, FVIIIa greatly enhanced the catalytic efficiency of both IXE217 variants to a greater extent (approximately 7 x 10(4)-fold) as compared to its effect on the wild-type factor IXa and the other two IXQ192 variants [by a factor of (1-2) x 10(4)]. Moreover, while both IXQ192 variants demonstrated small substrate selectivity similar to that of wild-type factor IXa, the selectivity of both IXE217 variants was greatly altered. Mutations at position 192 disturbed the interaction of factor IXa with physiological inhibitors. Although all variants formed an SDS-stable complex with antithrombin III (ATIII) equally well in the presence of heparin and were readily inhibited by ATIII in the absence of heparin, activated IXQ192K exhibited a slower stable complex formation with ATIII without heparin. On the other hand, only IXQ192E showed decreased interaction with TFPI. Our results demonstrate that positions 192 and 217 play different roles unique to factor IX in specifying the interaction of factor IX with substrates and inhibitors.

Aptamer beacons for the direct detection of proteins

We have designed a new class of molecules, which we term aptamer beacons, for detecting a wide range of ligands. Similar to molecular beacons, aptamer beacons can adopt two or more conformations, one of which allows ligand binding. A fluorescence-quenching pair is used to report changes in conformation induced by ligand binding. An anti-thrombin aptamer was engineered into an aptamer beacon by adding nucleotides to the 5'-end which are complementary to nucleotides at the 3'-end of the aptamer. In the absence of thrombin, the added nucleotides will form a duplex with the 3'-end, forcing the aptamer beacon into a stem-loop structure. In the presence of thrombin, the aptamer beacon forms the ligand-binding structure. This conformational change causes a change in the distance between a fluorophore attached to the 5'-end and a quencher attached to the 3'-end. Aptamer beacon can be a sensitive tool for detecting proteins and other chemical compounds.

High concentrations of serum inhibin in pre-eclampsia

OBJECTIVE

To evaluate maternal serum immunoreactive inhibin (ir-inhibin) concentrations in women with pre-eclampsia, and assess the correlation between serum ir-inhibin and HCG.

METHODS

The subjects comprised 28 pregnant women with suspected intrauterine growth retardation (IUGR) during the third trimester. Serum concentrations of ir-inhibin and HCG were measured in 13 women with pre-eclampsia and 15 pregnant women as control subjects. Serum ir-inhibin was determined by a double antibody radioimmunoassay, and HCG by a solid-phase immunoradiometric assay.

RESULTS

There were no significant differences in maternal characteristics between the pre-eclamptic group and control group. The pre-eclamptic group had significantly higher concentrations of serum ir-inhibin and HCG compared with the control group. The serum concentrations of ir-inhibin correlated positively with those of HCG.

CONCLUSION

The pre-eclamptic patients displayed high serum levels of ir-inhibin and HCG, and this might reflect hyperplasia of trophoblastic cells.

Hemophilia B with mutations at glycine-48 of factor IX exhibited delayed activation by the factor VIIa-tissue factor complex

Gly-48 is in the conserved DGDQC sequence (residues 47-51 of human factor IX) of the first EGF (EGF-1)-like domain of factor IX. The importance of the Gly-48 is manifested by two hemophilia B patients; factor IXTainan and factor IXMalmo27, with Gly-48 replaced by arginine (designated IXG48R) and valine (IXG48V), respectively. Both patients were CRM+ exhibiting mild hemophilic episodes with 25% (former) and 19% (latter) normal clotting activities. We characterize both factor IX variants to show the roles of Gly-48 and the conservation of the DGDQC sequence in factor IX. Purified plasma and recombinant factor IX variants exhibited approximately 26%-27% normal factor IX's clotting activities with G48R or G48V mutation. Both variants depicted normal quenching of the intrinsic fluorescence by increasing concentrations of calcium ions and Tb3+, indicating that arginine and valine substitution for Gly-48 did not perturb the calcium site in the EGF-1 domain. Activation of both mutants by factor XIa appeared normal. The reduced clotting activity of factors IXG48R and IXG48V was attributed to the failure of both mutants to cleavage factor X: in the presence of only phospholipids and calcium ions, both mutants showed a 4 to approximately 7-fold elevation in Km, and by adding factor VIIIa to the system, although factor VIIIa potentiated the activation of factor X by the mutants factor IXaG48R and factor IXaG48V, a 2 to approximately 3-fold decrease in the catalytic function was observed with the mutant factor IXa's, despite that they bound factor VIIIa on the phospholipid vesicles with only slightly reduced affinity when compared to wild-type factor IXa. The apparent Kd for factor VIIIa binding was 0.83 nM for normal factor IXa, 1.74 nM for IXaG48R and 1.4 nM for IXaG48V. Strikingly, when interaction with the factor VIIa-TF complex was examined, both mutations were barely activated by the VIIa-TF complex and they also showed abnormal interaction with VIIa-TF in bovine thromboplastin-based PT assays. Taken together, our results suggest that mutations at Gly-48 altered the interaction of factor IX with its extrinsic pathway activator (VIIa-TF complex), its macromolecular substrate (factor X), and its cofactor (factor VIIIa).

Engineered recombinant factor VII Q217 variants with altered inhibitor specificities

Recombinant factor VII with residue 217 (chymotrypsinogen numbering system) converted to alanine (VIIQ217A), glutamic acid (VIIQ217E), or glycine (VIIQ217G) was characterized. In a prothrombin time assay, VIIQ217E demonstrated 100%, VIIQ217A 15%, and VIIQ217G <1% clotting activities relative to wild-type VII. Binding of VIIQ217A and VIIQ217G to TF was comparable to that of wild-type VII to TF. All the variants were readily activated by factor Xa. Autoactivation in the presence of TF was efficient with VIIQ217E, slow with VIIQ217A, but undetected with VIIQ217G. Relative to wild-type VII added at the same concentration, VIIQ217E had no effect on the PT of normal plasma, whereas VIIQ217A slightly and VIIQ217G dramatically prolonged the clotting time in a dose-dependent manner. Activation of macromolecular substrates paralleled this functional inhibition. The k(cat)/K(M) values for factor X activation in the presence of TF were 2.4 for VIIaQ217E as compared to 1.9 (M(-)(1) s(-)(1) x 10(7)) for wild-type VIIa, 1.57 for VIIaQ217A, and 0.05 with VIIaQ217G. In comparison to wild-type VIIa, VIIaQ217E cleaved the chromogenic substrate S2765 (Z-D-Arg-Gly-Arg-pNA) with 10-fold higher k(cat). Analysis of the interactions with the inhibitors TFPI and antithrombin III demonstrated that VIIaQ217A but not VIIaQ217E or VIIaQ217G was inhibited less efficiently by TFPI either in the presence or in the absence of factor Xa. In contrast, VIIaQ217A association with antithrombin III in the presence of heparin was the fastest among the variants with a second-order rate constant of 2.31 (x10(3) M(-)(1) min(-)(1)), as compared to 0.47 and 1.47 for VIIaQ217E and wild-type VIIa, respectively. Our results demonstrate that residue Q(217) is important in regulating substrate and, more importantly, inhibitor recognition by VIIa.

Hemagglutinating activity of extracellular alkaline metalloendopeptidases from Vibrio sp. NUF-BPP1

Alkaline metalloendopeptidase (metalloprotease) AP1 (48 kDa) from Vibrio sp. isolated from the intestine of a five-barred goatfish (Parupeneus trifasciatus) was reported in our previous paper to produce AP2 (36 kDa) by releasing a peptide fragment (molecular mass of about 12 kDa) from the C-terminal end of AP1 by autodigestion. AP1 strongly agglutinated fish (flounder, Paralichthys olivaceus) and rabbit erythrocytes, and weakly chicken erythrocytes. In contrast, AP2 had no significant hemagglutinating activity toward any erythrocytes tested, except for weak activity on flounder erythrocytes, suggesting that the C-terminal region of AP1 may be required for the strong hemagglutinating activity. The optimum temperature for the hemagglutinating activity of AP1 was found to be lower than that for the proteolytic activity. At acidic pHs (below pH 7.5), the hemagglutinating activity of AP1 decreased, and its pH profile resembled that of the proteolytic activity. The hemagglutinating activity of AP1 was not observed in the presence of o-phenanthroline or synthetic and proteinous substrates, but different kinds of saccharides and lipids had no effect. While the proteolytic activity of AP1 was not affected by CaCl2, the hemagglutinating activity of AP1 decreased with increases in CaCl2 concentrations. These results suggested that the hemagglutinating activity of these proteases (AP1 and AP2) was most likely caused by their proteolytic action on erythrocyte cell surfaces.

Changing residue 338 in human factor IX from arginine to alanine causes an increase in catalytic activity

This study was designed to identify functionally important factor IX (FIX) residues. Using recombinant techniques and cell culture, we produced a mutant FIX with arginine at 338 changed to alanine (R338A-FIX). This molecule had approximately 3 times greater clotting activity than that of wild type FIX (wt-FIX) in the activated partial thromboplastin assay. R338A-FIX reacted normally with a panel of three FIX specific monoclonal antibodies and migrated on sodium dodecyl sulfate-polyacrylamide gels indistinguishably from wt-FIX. Using functional assays, we determined that R338A-FIXa's Kd for factor VIIIa (FVIIIa) was similar to that of wt-FIXa. Our kinetic analysis, using factor X as substrate, indicated that the mutation's major effects were a 3-fold increase in kcat and a 2-fold decrease in Km both manifested only in the presence of FVIIIa. R338A-FIXa's increased catalytic efficiency did not result from ablation of a thrombin sensitive site, reported to occur at arginine 338, since in our assays the thrombin inhibitor, hirudin, had no effect on activity of either wt-FIXa or R338A-FIXa. R338A-FIXa and wt-FIXa had equal activity, with or without FVIIIa, toward the synthetic substrate, methylsulfonyl-D-cyclohexylglycyl-arginine-p-nitroanilide. Interestingly, R338A-FIXa had reduced affinity for heparin. Therefore, we propose that R338A-FIXa's increased activity is not due to an allosteric effect on the active site, but that the Arg-338 residue is part of an exosite that binds both factor X and the mucopolysaccharide, heparin.

Alpha 1-adrenergic receptor subtype determinants for 4-piperidyl oxazole antagonists

Mutational studies in conjunction with ligand binding assays were used to examine the basis of alpha1-adrenergic receptor subtype selectivity for a series of 4-piperidyloxazole antagonists. A set of chimeric alpha 1A receptors were created by systematically substituting individual transmembrane domains from alpha 1D adrenergic receptors. The oxazole antagonists exhibited significant reductions in affinity against the receptor construct alpha 1A/D(TM2), and moderate reductions in affinity versus constructs alpha 1A/D(TM5), alpha 1A/B(TM5), and alpha 1A/D(TM6). Antagonist affinities for these chimeras exceeded those found for wild type alpha 1D and alpha 1B. Site-directed mutagenesis methods were then used to explore the role that individual residues in TM2 and TM5 play in ligand binding affinity and selectivity. These studies revealed that mutations at position 86 in the second transmembrane domain and position 185 in the fifth transmembrane domain of the alpha 1A receptor have a major impact on receptor subtype selectivity.

[Pilot study of relapsed osteosarcoma and brain tumor with ifosfamide, carboplatin and etoposide (ICE therapy)]

Ifosfamide, Carboplatin and Etoposide (ICE) therapy was used to treat 4 patients, 2 with refractory osteosarcoma, and one each with relapsed brain tumor and newly diagnosed brain tumor. ICE therapy was administered in doses of Ifosfamide 1,800 mg/m2 x 5, Carboplatin 400 mg/m2 x 2 and Etoposide 100 mg/m2 x 5. A total of 30 courses were administered. Two cases of osteosarcoma had a stable disease (range, 3-9 months) and 2 cases of brain tumor had a complete response by magnetic resonance imaging. Moderate or severe toxicity evaluated on a per course basis included: neutropenia 83%, thrombocytopenia 93%, fever 30%, hepatotoxicity 3%, and hemorrhagic cystitis 3%. The median time to hematologic recovery was 20 days. ICE therapy is highly effective for the treatment of refractory or recurrent solid tumors with acceptable toxicity.

[Study on coagulation fibrinolytic systems in predialysis patients with chronic renal failure--comparison between patients with chronic glomerulonephritis and patients with diabetic nephropathy]

To clarify the abnormalities of coagulation and fibrinolytic systems on predialysis patients with chronic renal failure, we measured indices of coagulation and fibrinolytic systems in 33 predialysis patients whose creatinine (Cr) levels were over 3.0 mg/dl. We termed twenty-four patients with chronic glomerulonephritis the "CGN group". We also termed nine patients wit diabetes mellitus the "DM group". We measured thrombin.antithrombin III complex (TAT), alpha 2-plasmin inhibitor plasmin complex (PIC), D-dimer, protein C, protein S, thrombomodulin (TM), vitronectin, tissue plasminogen activator.plasminogen activator inhibitor-1 complex (tPAI-C) in theses two groups. Furthermore, we measured the same indices after 6 months in the CGN group. As a result, the plasma levels of both TAT, PIC, TM/Cr ration in the DM group were significantly higher that those in the CGN group, changes in both protein S activities and plasma levels of tPAI-C were reduced significantly after 6 months. In conclusion, the abnormalities of coagulation and fibrinolytic systems in predialysis diabetic patients were stronger than those in predialysis patients with CGN. Furthermore, these abnormalities were worsened after 6 months in predialysis patients with chronic renal failure.

Phenylalanine in the second membrane-spanning domain of alpha 1A-adrenergic receptor determines subtype selectivity of dihydropyridine antagonists

The alpha 1-adrenergic receptors (alpha 1-AR) belong to the G-protein coupled seven-transmembrane biogenic amine receptor family. Three subtypes have been successfully cloned in the alpha 1-adrenergic receptor family, and they share 50% identical amino acid sequences and 70% similarity. We have constructed seven chimeric receptors of the alpha 1A-AR. Each of the chimeras contains alpha 1D-subtype amino acid sequences within the membrane-spanning domains. Comparisons of ligand affinities with these chimeras has provided information on the importance of certain amino acid residues in determining receptor subtype specificity in the alpha 1A- and alpha 1D-ARs. With ligands in the dihydropyridine series, the niguldipine analog 1 was found to have respective pKi's of 9.32 +/- 0.17 for alpha 1A-AR; 6.84 +/- 0.24 for alpha 1D-AR; and 6.76 +/- 0.28 for alpha 1A/D(TM2), respectively. This trend was also exhibited by two other niguldipine analogs, 2 and 3, which had similar pKi's toward alpha 1D-AR and alpha 1A/D(TM2). This subtype selectivity was also maintained in the piperdine derivative, 4, and alpha 1A-AR selective ligand, which showed the same parallel trends in binding affinities with alpha 1A-AR and the six chimeras as the niguldipine analogs. Since in considering the second membrane-spanning domain, the alpha 1A- and alpha 1D-ARs only differ at positions 76, 77, 85, and 86, we were able to show through mutational studies that phenylalanine 86 is solely responsible for the selectivity found in the chimeric receptor alpha 1A/D(TM2) exhibited against the ligands 1-4 used in this study. A model based on the rhodopsin structure places the amino acid at position 86 in the final turn toward the extracellular region. This is four helical turns above aspartic acid-79, a conserved amino acid in the second membrane-spanning domain. This is the first report that suggests a significant involvement of the second membrane-spanning domain in antagonist binding in the biogenic amines class of the superfamily of seven-transmembrane receptors.

Characterization of gamma-carboxyglutamic acid residue 21 of human factor IX

We investigated the functional role of gamma-carboxyglutamic acid (Gla) residue 21 of human factor IX, using site-directed mutagenesis to change the glutamic acid residue to aspartic acid (FIX21D). FIX21D had reduced activity in an activated partial thromboplastin time (aPTT) assay and was activated by factor XIa more slowly than wild-type factor IX (FIXwt). FIX21D underwent normal, two-stage calcium-dependent intrinsic fluorescence quenching, indicating that a folding event similar to that seen in FIXwt occurred upon the addition of calcium ions. Antibody A-7, which recognizes factor IX-specific residues at positions 33-40, bound FIX21D as well as FIXwt; however, the calcium-specific monoclonal antibody, JK-IX-2, whose epitope includes residues 1 and 22, did not recognize FIX21D. FIX21D bound phosphatidylserine/phosphatidylcholine (PS/PC) vesicles with Kd approximately 10-fold greater than FIXwt, as measured by a fluorescence light scattering assay. Finally, although FIXwt binds endothelial cells with a Kd of 2.8 nM, FIX21D did not bind endothelial cells. Molecular modeling simulations of FIXwt and FIX21D indicate that mutating Gla 21 to Asp causes structural changes in residues 3-5 and 8-10, as well as in two exposed calcium ions, consistent with the reduced function of FIX21D. Immunological and intrinsic fluorescence quenching assays and the molecular dynamics simulations suggest normal folding in the C-terminal region of the Gla domain. Thus we hypothesize the FIX21D has reduced JK-IX-2 and phospholipid and endothelial cell binding due to localized structural changes in residues 3-10 and the exposed calcium ions. Our study suggests that the Gla 21 to Asp mutation disrupts function in the N-terminal region of the Gla domain without affecting structure in the C-terminal Gla domain region.

In vitro mutagenesis study of two critical glutamic acids in the calcium binding loop of the factor IX heavy chain

We investigated the structural and functional significance of calcium binding in the factor IXa heavy chain by introducing point mutations into the probable calcium binding site (residues 235 and 245). According to factor IXa computer modelling based on trypsin x-ray structure, side chains of two glutamic acid residues, 235 and 245, together with backbone carbonyl groups of residues 237 and 240, bind a calcium ion. Factor IX clotting activity decreased approximately 25 percent on substitution of glutamic acid 235 with lysine. Activity decreased more than 90 percent on substitution of glutamic acid 245 with lysine. Activity also decreased more than 90 percent on substitution of both glutamic acids by lysines. Factor XIa cleavage of factor IXGlu235Lys and factor IXGlu245Lys appeared normal by polyacrylamide gel analysis. (Factor IXGlu235Lys: Factor IX with Lysine substituted for Glutamic acid at residue 235. Factor IXGlu245Lys: Factor IX with Lysine substituted for Glutamic acid at residue 245. Factor IXGlu235&245Lys: Factor IX with Lysine substituted for Glutamic acid at residues 235 and 245.) Activated factor IXGlu235Lys bound the fluorescent active site probe, p-aminobenzamidine, normally, while factor XIa cleaved factor IXGlu245Lys and factor IXGlu235&245Lys failed to bind p-aminobenzamidine. Plasma purified factor IX titrated with terbium showed an increase in luminescence; however, factor IXGlu235Lys and factor IXGlu245Lys had no effect on terbium luminescence. Radioimmunoassays indicate that in calcium's absence, factor IXGlu245Lys adopts a conformation similar to normal factor IX in the presence of calcium. By contrast, factor IXGlu245Lys's conformation in the presence of calcium is similar to that of plasma purified factor IX in the absence of calcium.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of a factor IX variant with a glycine207 to glutamic acid mutation

Factor IXTaipei9 is a factor IX variant from a hemophilia B patient with reduced levels of circulating protein molecules (cross-reacting material reduced, CRM). This variant contained a glycine (Gly) to glutamic acid (Glu) substitution at the 207th codon of mature factor IX. The functional consequences of the Gly-->Glu mutation in factor IXTaipei9 (IXG207E) were characterized in this study. Plasma-derived IXG207E exhibited a mobility similar to that of normal factor IX on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Its specific activity was estimated to be 3.5% that of the purified normal factor IX in a one-stage partial thromboplastin time assay (aPTT). Cleavage of factor IXG207E by factor XIa or factor VIIa-tissue factor complex appeared to be normal. When the calcium-dependent conformational change was examined by monitoring quenching of intrinsic fluorescence, both normal factor IX and IXG207E exhibited equivalent intrinsic fluorescence quenching. Activated factor IXG207E (IXaG207E) also binds antithrombin III equally as well as normal factor IXa. However, aberrant binding of the active site probe p-aminobenzamidine was observed for factor XIa-activated factor IXG207E, indicating that the active site pocket of the heavy chain of factor IXaG207E was abnormal. Moreover, the rate of activation of factor X by factor IXaG207E, as measured in a purified system using chromogenic substrates, was estimated to be 1/40 of that of normal factor IXa. A computer-modeled heavy-chain structure of factor IXa predicts a hydrophobic environment surrounding Gly-207 and this Gly forms a hydrogen bound to the active site serine-365. The molecular mechanism of the Gly-->Glu mutation in factor IXTaipei9 might result in the alteration of the microenvironment of the active site pocket which renders the active site serine-365 inaccessible to its substrate.

The role of amino-terminal residues of the heavy chain of factor IXa in the binding of its cofactor, factor VIIIa

The purpose of this study is to determine which residues of the factor IXa heavy chain are important for interaction with the cofactor of factor IXa, factor VIIIa. Because the monoclonal antibody (MoAb) FXC008 inhibits interaction between factors IXa and VIIIa, and because it also reacts with residues 181-310 of the factor IXa heavy chain, we used the computer-modelled structure of the factor IXa heavy chain to select charged surface residues likely to interact with FXC008 and/or factor VIIIa. We made mutations in the region of residues 181-310 of the heavy chain of factor IX, and replaced these amino acids individually with those located at the same position in factor X. The mutated factor IX retained complete clotting activity and thus interacted normally with factor VIIIa. Five mutant proteins (factor IXK214F, factor IXK228R, factor IXE240Q, factor IXK247V, and factor IXN260K) reacted with heavy chain-specific MoAbs FXC008 and A-5. Neither factor IXD276K nor factor IXR248H bound to FXC008. Factor IXR252V had reduced affinity to FXC008. Our results suggest the following: (1) factor IXa residues 214, 228, 240, 247, 248, 252, 260, and 276 are not involved in specific interaction with factor VIIIa; and (2) the FXC008 and factor VIIIa binding sites may not share critical residues.

Enhancement of the anti-tumor activity of recombinant interleukin-2 (rIL-2) by immunocomplexing with an F(ab')2 fragment of murine monoclonal antibody against rIL-2

We have investigated the biological properties of an immune complex composed of recombinant interleukin-2 (rIL-2) and an F(ab')2 fragment of a monoclonal antibody against rIL-2 in mice for the induction of killer cells and anti-tumor activity, as well as the pharmacokinetic properties of the immune complex injected subcutaneously into mice. The immune complex demonstrated sustained serum rIL-2 levels, with a 2.4-times longer "mean-residence-time" than free rIL-2. A more significant portion of rIL-2 was detected in lymph nodes after the subcutaneous injection of the immune complex than with rIL-2 alone. Splenic lymphocytes from mice given the immune complex showed higher killer cell activity against YAC-1 and P815 cells than those from mice given rIL-2 alone. The immune complex also exerted a more significant anti-tumor effect in a dose-dependent manner in Meth-A fibrosarcoma-bearing mice than dit rIL-2 alone.

Pharmacokinetic alteration in rats of recombinant interleukin-2 (rIL-2) by immunocomplexing with a monoclonal antibody against rIL-2

We have investigated the pharmacokinetic alteration in rats of recombinant interleukin-2 (rIL-2) by immunocomplexing with a monoclonal antibody against rIL-2. Serum rIL-2 levels after the intravenous administration of the immune complex at a dose of 100 micrograms/rat as rIL-2 were significantly higher than those after intravenous administration of rIL-2 alone at the same dose. Pharmacokinetic analysis indicated that the distribution volume of rIL-2 decreased from 74.0 to 10.3 ml/rat, while the elimination rate of rIL-2 was little changed by immunocomplexing with the antibody. On the other hand, serum rIL-2 levels after the subcutaneous administration of the immune complex at a dose of 100 micrograms/rat as rIL-2 were sustained longer than those after the subcutaneous administration of rIL-2 alone at the same dose, and Tmax shifted from 0.83 to 3.0 h by immunocomplexing with the antibody. Pharmacokinetic analysis also revealed that the mean-residence-time of rIL-2 increased from 1.98 to 6.52 h, and the area-under-the curve of rIL-2 decreased slightly, from 834 to 548 ng.h/ml, by immunocomplexing with the antibody.

Enhancement of anti-tumor activity of recombinant interleukin-2 (rIL-2) by immunocomplexing with a monoclonal antibody against rIL-2

We have investigated biological properties of an immune complex of recombinant interleukin-2 (rIL-2) and a monoclonal antibody against rIL-2 in mice for induction of killer cells and for anti-tumor activity. We have also examined the clearance of subcutaneously-injected immune complex in mice and compared it with that of rIL-2 alone. Plasma rIL-2 levels were sustained longer in mice given the immune complex than in mice given rIL-2 alone at a dose of 10 micrograms/mouse, and they were detectable even at 24 hours after the administration of the immune complex, while they fell to undetectable levels by 6 hours after the administration of rIL-2 alone. A more significant portion of rIL-2 was detected in lymph nodes after subcutaneous injection of the immune complex than that of rIL-2 alone. Splenic lymphocytes from mice given the immune complex demonstrated a higher killer cell activity against YAC-1 cells than those from mice given rIL-2 alone. The immune complex also exerted more significant anti-tumor effect in a dose-dependent manner in Meth-A fibrosarcoma-bearing mice than rIL-2 alone. Our results indicate that immunocomplexing of rIL-2 with an antibody against rIL-2 provides a useful tool as the drug delivery system for cancer therapy using rIL-2.

Effect of recombinant human erythropoietin administration on immunological indices in patients undergoing chronic hemodialysis

In patients undergoing chronic hemodialysis, marked anemia may cause decreased immunological function. To improve this anemia, we investigated the effect on immunological indices of recombinant human erythropoietin (rHuEPO) administration in 24 hemodialysis patients (13 males and 11 females) with renal anemia complications. Their mean age was 54.9 +/- 14.8 years and the mean duration of dialysis was 100.5 +/- 54.9 months. The subjects were treated with rHuEPO for 12 months, which helped to maintain a hematocrit value elevated by 5% from the baseline. Cell-mediated immunity and humoral immunity were assessed prior to as well as throughout the treatment period. Of the total number of patients studied, the anemia of 16 improved while 8 did not show signs of sufficient improvement. The improved group showed an increase in in vitro lymphocytic response to phytohemagglutinin (PHA), CD4/CD8, CD16 and serum IgM levels, while the CD8 level decreased significantly. Improvement in the general physical condition with rHuEPO treatment appeared to be associated with the changes in immunological indices, but the precise mechanism remains obscure.

Mutations in the catalytic domain of factor IX that are related to the subclass hemophilia Bm

Hemophilia Bm, a variant of hemophilia B, results in a marked increase in the ox brain prothrombin time. Mutations known to cause hemophilia Bm occur at residue 180, 181, or 182 near the amino terminus of the heavy chain and at residue 311, 364, 368, 390, 396, or 397 near the activation site of factor IX (Giannelli et al., 1990). In this study we replaced factor IX residues 181, 182, and 390 in separate experiments by site-directed mutgenesis. Valine 181 was replaced by isoleucine or alanine, and valine 182 was replaced by alanine or glycine. Alanine 390 was replaced by valine or aspartic acid. Recombinant factor IXs were expressed in human kidney 293 cells and purified by absorption and elution from a conformational specific monoclonal antibody column. The results show that factor IX Bm is a function not only of the position of the mutated amino acid but also of the particular amino acid substituted. For example, when valine 181 or 182 was replaced by small hydrophobic amino acids (alanine and glycine), factor IXs were found to have significantly decreased clotting activity. Unlike the naturally occurring mutations (Val181 --> Phe181 or Val182 --> Leu182), however, the small amino acid replacements did not result in prolonged ox brain prothrombin times. Surprisingly, the Ala390 --> Asp390 exchange did not affect clotting activity or binding to the macromolecular inhibitor antithrombin III. The Ala390 --> Val390 exchange resulted in loss of both clotting activity and binding to antithrombin III. These results suggest that residue 390 is not directly involved in binding to antithrombin III.(ABSTRACT TRUNCATED AT 250 WORDS)

The binding of human factor IX to endothelial cells is mediated by residues 3-11

We have used chimeras and point mutations of recombinant coagulation factor IX to examine factor IX's specific interaction with bovine endothelial cells. Previously (Toomey, J. R., Smith, K. J., Roberts, H. R., and Stafford, D. W. (1992) Biochemistry 31, 1806-1808), we restricted the region of factor IX responsible for binding to endothelial cells to its Gla domain. Molecular modeling of the Gla domain of factor IX using the coordinates of the Gla domain of bovine prothrombin-(1-145) (Soriano-Garcia, M., Padmanabhan, K., deVos, A. M., and Tulinsky, A. (1992) Biochemistry 31, 2554-2566) reveals two major surface determinants whose sequences differ among factors IX, X, and VII. A chimeric protein comprised of the Gla domain of factor VII with the remainder of the molecule of factor IX did not bind to the endothelial cell binding site. We changed residues 33, 34, 35, 39, and 40 to those of factor IX without restoring endothelial cell binding. Replacement of amino acid residues 3-10 with those of factor IX restored normal binding. With the knowledge that specific binding was localized to the first 11 amino acids, point mutations were made at residues predicted to be on the surface in this region of the factor IX molecule. Changing lysine 5 to alanine (K5A) or valine 10 to lysine (V10K) resulted in loss of binding with total retention of in vitro clotting activity. The lysine 5 to arginine (K5R) mutation also was fully active in vitro but displayed 3-fold tighter binding. In addition to defining the sequence of factor IX necessary for binding to endothelial cells, these results suggest that the binding site is not phospholipid but instead is specific, and in all likelihood, protein.

Molecular dynamics simulation of bovine prothrombin fragment 1 in the presence of calcium ions

Early solvation-induced structural reorganization of calcium prothrombin fragment 1 is simulated with molecular dynamics. Initial coordinates are those of the 2.2-A resolution crystal structure [Soriano-Garcia, M., Padmanabhan, K., de Vos, A. M., & Tulinsky, A. (1992) Biochemistry 31, 2554-2556]. The molecular dynamics code AMBER, appropriately modified to include long-range (less than or equal to 22.0 A) ionic forces, was employed. The solution structure appears to equilibrate within 100 ps. Although minor changes are seen in various structural domains, the early solution structure basically maintains an intricate network of nine gamma-carboxyglutamic acid (Gla) residues encapsulating seven calcium ions. However, the Gla domain moves with respect to the kringle domain. This motion is mainly due to the movement of Ser34-Leu35 that appears to be a flexible hinge between the domains. The N-terminus of Ala 1 is in a tightly bound complex with three Gla residues that remains stable in the solution structure when the long-range electrostatic cutoff is employed and the near planar alignment of the seven calcium ions is only slightly distorted. The simulation structure is discussed in terms of experiments that studied calcium ion-induced quenching of the intrinsic fluorescence, protection of the N-terminal amino group from acetylation by calcium ions, chemical modification of the N-terminus to a trinitrophenyl derivative, and the possibility of a calcium-binding site(s) in the kringle domain.

Factor XSanto Domingo. Evidence that the severe clinical phenotype arises from a mutation blocking secretion

Factor X (FX) is a vitamin K-dependent plasma protein required for the intrinsic and extrinsic pathways of blood coagulation. FXSanto Domingo is a hereditary FX deficiency which is characterized clinically by a severe bleeding diathesis. The proposita has a FX activity of less than 1% and a FX antigen of less than 5%. We have determined the molecular basis of the defect in the FXSanto Domingo gene by amplification of all eight exons with polymerase chain reaction and subsequent sequence analysis. The patient is homozygous for a G----A transition in exon I at codon -20 (numbering the alanine at the NH2 terminus of the mature protein as +1), resulting in the substitution of arginine for glycine in the carboxy-terminal part of the signal peptide. This amino acid change occurs near the presumed cleavage site of the signal peptidase. We hypothesized that the mutation might prevent cleavage by the signal peptidase which in turn would impair proper secretion of the FX protein. To test this hypothesis, we compared the expression of wild type and mutant FX cDNA in a human kidney cell line. Wild type and mutant constructs in the expression vector pCMV4 were introduced into the human embryonic kidney cell line 293 by calcium phosphate transfection. FX antigen levels in the supernatant of the cells harboring the wild type construct were 2.4 micrograms/10(7) cells per 24 h, whereas antigen levels in media from cells containing the FXSanto Domingo construct were undetectable. No FX antigen was detected in the cell lysates of cells transfected with the mutant construct. To insure that the difference in protein levels was not due to a difference in steady state levels of mRNA, Northern analysis was performed on RNA from the cell lysates of both constructs. The results showed a transcript of the same size, present in roughly equal amounts, in both cases. Thus, the defect in the signal sequence of FXSanto Domingo exerts its effect posttranscriptionally. FXSanto Domingo is the first described example of a bleeding diathesis due to a mutation in the signal sequence.

Expression and characterization of human factor IX. Factor IXthr-397 and factor IXval-397

Factor IXLong Beach has a single amino acid substitution at 397 (Ile to Thr) in the catalytic domain which results in severe hemophilia B. Recent investigations have shown that the substitution of threonine for isoleucine at 397 may affect a part of the macromolecular substrate binding site. Because threonine has a hydroxyl group in its side chain, it is possible that this hydroxyl group makes new hydrogen bonds and disturbs the substrate binding site. We used three techniques: molecular biology, which includes site-directed mutagenesis and recombinant protein expression in tissue culture; computer-aided kinetic data analysis; and molecular modeling to study this mutation site. We have produced two mutant factor IX molecules that have isoleucine 397 replaced by valine or threonine. Factor IXwild type and the two mutants (factor IXVal and factor IXThr) were expressed in human kidney cells and purified using a conformation-specific monoclonal antibody column. After the activation by factor XIa, these three molecules were able to bind p-aminobenzamidine and increase its fluorescence intensity in a similar manner. Factor IXVal and factor IXwild type had indistinguishable activities in an activated partial thromboplastin time (aPTT) assay and similar kinetic parameters with factor X as a substrate. Factor IXThr had only 5% clotting activity compared with normal factor IX, a slightly lower Km and significantly reduced kcat, using factor X as a substrate. We developed energy-refined (AMBER v.3.1) computer models of the three factor IX molecules based on previous work. Three factor IXa models (Ile, Val, or Thr at 397) with a fragment of the factor X activation site were used to predict the effect of the mutation at 397 and evaluate the significance of the new hydrogen bond thought to form between the side chain hydroxyl group of threonine 397 and the carbonyl oxygen of tryptophan 385. This new hydrogen bond would affect the position of an amide proton of adjacent glycine 386 which has been proposed to make a hydrogen bond with a backbone carbonyl oxygen of the P3 residue of factor X. In addition to the new hydrogen bond, there is significant movement in the side chain of tryptophan 385 between the factor IXawild type-factor X model and the factor IXaThr-factor X model that could interfere with substrate binding. This movement could be caused by the change in the molecular volume, the orientation of the side chain at 397, and the new hydrogen bond.

Increased tumor cisplatin levels in heated tumors in mice after administration of thermosensitive, large unilamellar vesicles encapsulating cisplatin

Hyperthermia (HT)-dependent cisplatin (CDDP) release and tumor CDDP level increase after the administration of thermosensitive, large unilamellar vesicles (LUVs: LUV-1 and LUV-2) and a thermosensitive, small unilamellar vesicle (SUV: SUV-1) were examined in comparison with those following administration of a non-thermosensitive LUV (LUV-3) and a CDDP solution (Sol) in tumor bearing mice. The LUV-1 and LUV-2 released CDDP at a faster rate than SUV-1 when incubated in saline at temperatures between 41 and 44 degrees C. The blood CDDP levels after liposome administration were higher than those after Sol administration. The systemic clearance of LUV-2 was slightly larger than those of the other liposomes. The tumor CDDP levels after thermosensitive liposome administration were increased in response to HT in comparison to LUV-3 or Sol. The increased ratio for LUV-1 was the largest. The ratio of the area under the tumor CDDP level versus time curve (AUC) for LUV-1 + HT to the AUC for Sol + HT was approximately 5. The results indicate that (1) the tumor-CDDP level increase after thermosensitive liposome administration is due to CDDP release from the liposome in the blood at or adjacent to the heated tumor, (2) the increase is highly dependent on the heat sensitivity and systemic stability of the liposome, and (3) LUV, such as LUV-1, exhibit higher heat sensitivity and larger, targeted drug delivery efficiency than SUV.

Enhanced antitumor activity in mice after administration of thermosensitive liposome encapsulating cisplatin with hyperthermia

The antitumor effect of cisplatin-(CDDP)-encapsulated thermosensitive large unilamellar liposome (ThLip) administration with hyperthermia (HT) was examined in mice bearing Meth A fibrosarcoma. The tumor Pt levels after ThLip administration were increased in response to HT. The targeting index was approximately 3. The antitumor activity of ThLip + HT, as measured by tumor growth delay or tumor weight inhibition, was larger than that of ThLip without HT or a solution with or without HT. The CDDP dose in ThLip + HT to give equivalent tumor growth delay in solution (40 micrograms/mouse) + HT was about 10 micrograms/mouse, and therefore the targeted drug delivery enhancement ratio was about 4. The ratio correlates with the targeting index. The blood urea nitrogen level, as an indicator of CDDP nephrotoxicity, was increased 7 days after the administration of ThLip (40 micrograms CDDP/mouse) with HT. However, this blood urea nitrogen level rise was independent of the activity enhancement by the liposome. These findings suggest that the HT combined CDDP delivery system using ThLip can decrease the effective CDDP dose, thereby increasing its therapeutic index.

Alkaloid biosynthesis in somatic hybrids of Duboisia leichhardtii F. Muell. and Nicotiana tabacum L

Somatic hybrids of Duboisia leichhardtii and Nicotiana tabacum were obtained by electrofusion followed by individual cloning. The hybrid nature of the cloned cells and regenerated shoots was confirmed by cytological investigation and ribosomal-DNA analysis, respectively. The hybrid plantlets predominantly produced nicotine, while Duboisia plantlets produced both tropane and nicotine alkaloids. Activities involved in tropane-alkaloid biosynthesis were examined in a series of precursor-feeding experiments. The presence in the hybrid plants of activities responsible for the reduction of tropinone, the hydroxylation and epoxidation of hyoscyamine, and the conversion of nicotine to nornicotine demonstrated the presence of the Duboisia genes for these enzyme activities.

Cystic pulmonary hamartoma

A case of cystic pulmonary hamartoma is reported and the literature is reviewed. According to the literature, only 6 well-documented cases have been previously reported, and all the patients including our patient fared well after operation.

[A surgical case report of acute pyogenic pericarditis in a 9-month infant]

A surgical case of acute pyogenic pericarditis in a 9-month old infant who developed pericardial tamponade rapidly is reported. An anterior pericardiectomy through a left lateral thoracotomy was performed. The baby subsequently made an uncomplicated recovery and was discharged on the 16th postoperative day.

[Study on cefotaxime in respiratory surgery: transfer to lung tissue and kinetics in serum]

Cefotaxime (CTX) was intravenously administered in a dose of 1 g to patients just prior to lung surgery. Lung tissue specimens were collected at 1, 2 and 3 hours after the CTX administration, and the concentration of CTX in each specimen was determined. At the same time, the concentration of CTX in the serum was also measured. The results are summarized below. 1. Determination of the CTX concentration in the lung tissue using bioassay showed values of 3.78 +/- 1.93 micrograms/g at 1 hour after CTX administration, 1.91 +/- 0.92 microgram/g at 2 hours, and 1.19 +/- 1.04 micrograms/g at 3 hours. 2. Determination of the CTX concentration in the serum using bioassay showed values of 36.9 +/- 14.4 micrograms/ml at 30 minutes after CTX administration, 22.5 +/- 10.5 micrograms/ml at 1 hour, 12.8 +/- 6.32 micrograms/ml at 2 hours, 8.52 +/- 5.54 micrograms/ml at 3 hours, and 3.98 +/- 3.19 micrograms/ml at 6 hours. The serum half-life was calculated to be 1.82 hours. 3. The CTX concentration of 3.78 +/- 1.93 micrograms/g in the lung tissue at 1 hour after CTX administration was more than 10 times higher than the MIC80 values for Streptococcus pneumoniae (MIC80 less than or equal to 0.025 microgram/ml) and Klebsiella pneumoniae (0.05 micrograms/ml), 2 of the principal causative organisms of respiratory tract infections. The pattern of change in concentrations of CTX in the serum of these surgical patients was concluded to be similar to the pattern in healthy adult subjects. On the basis of the results summarized above, it appears that CTX is a useful antimicrobial agent for application in the field of respiratory surgery.

Orally active 1-(cyclohexyloxycarbonyloxy)alkyl ester prodrugs of cefotiam

Orally active 1-(alkyl substituted cyclohexyloxycarbonyloxy)alkyl ester prodrugs (9b-h) of 7 beta-[2-(2-aminothiazol-4-yl)acetamido]-3- [[[1-(2-dimethylaminoethyl)-1H-tetrazol-5-yl]thio]-methyl]ceph+ ++-3- em-4-carboxylic acid (cefotiam, CTM) have been studied as well as the thia (9i) and aza (9j) analogs. These represent derivatives of the 1-(cyclohexylacetoxy)ethyl ester (2) of CTM. The syntheses and oral bioavailability (BA) in mice are described. Among them, the 1-(cyclohexyloxycarbonyloxy)butyl ester (9h) gave the highest BA, 93.5%; the esters having a cyclohexyloxy group in the ester moiety gave BAs of more than 75%, although the BA of the 1-(ethoxycarbonyloxy)ethyl ester (9a) was only 23.9%. The thia analog showed a moderate BA, 46%, but the aza analog, 9j, did not show a BA of CTM. These results indicate that the 1-(substituted cyclohexyloxycarbonyloxy)alkyl group was the suitable promoiety to improve the oral BA of CTM. Chiral 1-(alkoxycarbonyloxy)alkyl groups used as the ester moiety, gave an almost 1: 1 mixture of diastereoisomeric esters. These were tested as such. However, an experiment in which the separated isomers of the 1-(cyclohexyloxycarbonyloxy)ethyl ester (9d) were administered orally confirmed that both diastereoisomers gave identical BAs.

Preparation of 1-acyloxyethyl esters of 7-[2-(2-aminothiazol-4-yl)acetamido]-3-[[[1-(2-dimethylaminoe thy l)-1H-tetrazol-5-yl]thio]-methyl]ceph-3-em-4-carboxylic acid (cefotiam) and their oral absorption in mice

In a separate study on the orally active acyloxymethyl esters (1) of 7-[2-(2-aminothiazol-4-yl)acetamido]-3-[[[1-(2-dimethylaminoethyl) - 1H-tetrazol-5-yl]thio]methyl]ceph-3-em-4-carboxylic acid (cefotiam, CTM), we have shown, by quantitative structure-oral bioavailability (BA) relation analysis, that the R2 group in the acyl group R2CO must have both an adequate lipophilicity (Hansch's lipophilic parameter, pi) and steric hindrance (Taft's Es value). However, to satisfy these requirements, a complex alkyl group R2 must be employed, the ester of which is difficult to synthesize and has unique metabolic fate. In this study, we selected and prepared the 1-acyloxyethyl esters (2) of CTM instead of 1 to avoid R2 groups that are too complicated. We found that the esters (2) gave improved oral BAs over 1: the 1-(3-methyl-valeryloxy)ethyl ester (2h) showed the highest peak plasma CTM level (Cmax) comparable to that obtained after subcutaneous injection of CTM. The 1-(cyclohexylacetoxy)ethyl ester (2t), the 1-(2-ethylbutyryloxy)ethyl ester (2j), and 2h showed BAs near 100%. For these esters (2), good correlations were also observed among the pi, the Es values of R2, and the log Cmax and log BA in the analysis of the quantitative structure-oral bioavailability relation: an ester having an alkyl group as R2 with a pi value of 3.07 or 3.08 and a Es value of -1.04 or -1.29 gave the highest Cmax or BA, respectively. As expected, the optimal pi values are almost the same as those obtained with 1 but the optimal Es values are larger (Es = -2.07). Thus, it has been confirmed by preparing 1-acyloxyethyl esters (2) of CTM that the oral bioavailability of CTM can further be improved without preparing acyloxymethyl esters (1) with a complicated acyl group.