Enhanced expression of GTP-binding proteins in differentiated U937 monocytic cells: possible involvement of tyrosine kinase and protein kinase C

Seven Arxula adeninivorans strains originating from The Netherlands (CSIR 1136, CSIR 1138 and CBS 8244T), South Africa (CSIR 1147, CSIR 1148 and CSIR 1149) and Siberia (Ls3) were compared concerning their secretory glucoamylase. Within the spectrum of secretory polypeptides obtained by SDS-polyacrylamide gel electrophoresis, the glucoamylase corresponding polypeptide, could be identified by means of specific antibodies directed against the glucoamylase of strain Ls3. The molecular masses of the glucoamylases vary from 84 to 95 kDa. After endoglycosidase F treatment of the secretory proteins, the N-linked carbohydrate content for each glucoamylase could be quantified at about 25%. Glucoamylase activity staining of secretory proteins separated under nondenaturing conditions revealed one glucoamylase active protein for the Dutch strains and two active forms for the strains originating from South Africa and Siberia. Highest activities of glucoamylase can be measured at the end of the exponential growth phase for each strain. The Dutch strain CSIR 1138 secretes the highest activity. Optimum values for temperature and pH were determined and compared. By means of pulsed field gel electrophoresis and Southern analysis, the glucoamylase corresponding gene could be localized on the second of the four chromosomes of each yeast strain.     

A partially folded intermediate during tubulin unfolding: its detection and spectroscopic characterization

The unfolding reaction of the dimeric protein tubulin, isolated from goat brain, was studied using fluorescence and circular dichroism techniques. The unfolding of the tubulin dimer was found to be a two-step process at pH 7. The first step leads to the formation of an intermediate conformation, stable at around 1-2 M urea, followed by a second step that was due to unfolding of the intermediate state. At pH 3, the urea-induced biphasic unfolding profiles obtained at pH 7 became a one-step process indicating that a stable intermediate was also formed at this pH. The intermediate at pH 3 was more stable toward urea denaturation than that at pH 7. The intermediate state has about 60% secondary structure, partially exposed aromatic residues, and less tertiary structure as compared to the native states. Also, hydrophobic surfaces were more exposed in the intermediate than in the native or unfolded states. These results indicate that the intermediate state observed during tubulin unfolding is not only distinct from both the native and unfolded forms but also possesses some properties characteristic of a molten globule.     

Utility of a rectal suppository containing the antiepileptic drug zonisamide

A suppository of zonisamide (ZNS) was investigated from the viewpoint of pharmaceutical evaluation, pharmacokinetics and pharmacological effect. Two types of ZNS suppositories were prepared. One used Witepsol (H-15:S-55 = 3:1) as a lipophilic base and the other polyethylene glycol (PEG, 4000:1500 = 4:1) as a hydrophilic base. The in vitro release rate of ZNS from the PEG suppository was significantly rapid compared with that of ZNS from Witepsol. Male Wistar rats were administered ZNS (20 mg/kg) using an intravenous, oral or rectal (PEG or Witepsol) route. The absorption of ZNS from the PEG suppository was more rapid than that of ZNS from the Witepsol suppository or from the oral preparation. The peak plasma concentration (Cmax) after a rectal administration of ZNS with Witepsol or PEG suppository was significantly higher than that after the oral administration of ZNS. However, the bioavailability of the three preparations was approximately 100%. Male ICR mice were administered ZNS (80 mg/kg) using the oral or rectal (PEG or Witepsol) route. A positive correlation was observed between the electroshock seizure (ES) threshold and ZNS concentration in plasma or brain. Further, there was no significant difference in the ES threshold or the ZNS concentration in plasma or brain among the three preparations. These results indicate that a ZNS suppository is a very useful preparation from the viewpoint of both pharmacokinetics and pharmacological action.     

Congenital Becker''s nevus with a familial association

Coprecipitates were prepared using different ratios of flutamide with polyvinyl pyrrolidine (PVP), polyethylene glycol (PEG) 4000 and 6000. Drug solubility in carrier solutions, thin layer chromatography (TLC), differential scanning calorimetry (DSC), infra-red spectroscopy (IR), uniformity of drug content, drug dissolution from its respective systems and effect of aging on the physico-chemical parameters of stored flutamide-polymer system were studied. PEG 6000 was found to be the most efficient polymer in increasing both the solubility and the release rate of flutamide. Interaction was found to be complete in certain ratios of drug/polymer systems. The dissolution pattern of flutamide from all the prepared systems appeared to fit a first order mechanism. Physico-chemical parameters of flutamide/carrier systems were not influenced by storage.     

协同萃取法回收地浸采铀工艺树脂中铼

介绍了伯胺和磷酸三丁酯协同萃取回收铼的实验研究,考察了水相初始pH值、萃取剂组成、相比(O/W)对铼萃取率的影响.结果表明:协同萃取体系在pH 2～10范围内铼的萃取率均在97％以上,但酸性条件下伯胺N1923溶解损失较大,水相初始pH9.5为最佳萃取酸度,以有机相30％ N1923-50％TBP-20％磺化煤油萃取铼效果最佳,并采用3％ NaOH反萃铼,萃取和反萃相比均控制1:1.铼的萃取率可达99％以上,反萃率达97％以上.萃取分配比随水相中铼初始含量增大而越大,水相中大量铀的存在不影响铼的萃取,硝酸根的存在对铼的萃取率也影响较小.硫酸地浸采铀工艺中,铀和铼分别以[ UO2 (SO4)2]2-,[ UO2 (SO4)3]4-,ReO4-阴离子形式转入地浸渡,同时被阴离子交换树脂D231吸附.适采用一定浓度硝酸盐或氯化物解吸铀工艺树脂中的铀,以10％ NH4NO3-8％ NH4OH解吸树脂中的铼.伯胺和磷酸三丁酯协同萃取法可有效用于铀工艺树脂解吸液中铼的回收,从而为铀矿中铼的回收进一步工业试验提供参数.     

Synthesis and Properties of Heteropoly Tungstovanadogermanic Complexes with Rare Earths

Ｈｅｔｅｒｏｐｏｌｙｃｏｍｐｏｕｎｄｉｓａｎｅｗｃａｔａｌｙｓｔｗｉｔｈｍａｎｙｆｕｎｃｔｉｏｎｓｉｎｃｈｅｍｉｓｔｒｙｉｎｄｕｓｔｒｙ .Ｉｔｓｅｘｃｅｌｌｅｎｔｃａｔａｌｙｔｉｃｐｅｒｆｏｒｍａｎｃｅｉｓｄｅｔｅｒｍｉｎｅｄｂｙｉｔｓｃｏｍｐｏｓｉｔｉｏｎａｎｄｓｔｒｕｃｔｕｒｅ .Ｉｔｈａｓｓｉｍｐｌｅｃｏｍｐｏｓｉｔｉｏｎａｎｄｆｉｘｅｄｓｔｒｕｃｔｕｒｅ ,ａｌｔｈｏｕｇｈｉｔｍａｙｃｏｎｓｉｓｔｏｆｍａｎｙｅｌｅｍｅｎｔｓ .Ｉｔｓｓｔｒｕｃｔｕｒｅａｎｄｐｒｏｐｅｒｔｙｃａｎｂｅｃｈａｎｇ…     

Endgroup analysis of polyethylene glycol polymers by matrix-assisted laser desorption/ionization Fourier-transform ion cyclotron resonance mass spectrometry

Fourier-transform ion cyclotron resonance mass spectrometry (FTICR-MS) by external injection of matrix-assisted laser desorbed and ionized (MALDI) polymers offers good possibilities for characterization of low molecular weight homopolymers (MW range up to 10 kDa). The molecular masses of the molecular weight distribution (MWD) components of underivatized and derivatized (dimethyl, dipropyl, dibutyl and diacetyl) polyethylene glycol (PEG) 1000 and 4000 were measured by MALDI-FTICR-MS. These measurements have been performed using a commercial FTICR spectrometer with a home-built external ion source. MALDI of the samples with a 2,5-dihydroxybenzoic acid matrix in a 1000:1 matrix-to-analyte molar ratio produces sodiated molecules in a sufficient yield to trap the ions in the ICR cell. The masses of the molecular weight distribution of PEG components were measured in broad-band mode with a mass accuracy of < 5 ppm in the mass range around 1000 u and within 40 ppm accuracy around 4000 u. From these measurements, the endgroup mass of the polymer was determined by correlation of the measured component mass with the degree of polymerization. The masses of the PEG endgroups have been determined within a deviation of 3-10 millimass units for the PEG1000 derivatives and 10-100 millimass units for the PEG4000 derivatives, thus confirming the identity of the distal parts of the model compounds.     

Extraction and Stripping of Ytterbium （Ⅲ） from H2SO4 Medium by Cyanex 923

Ytterbiumand other lanthanide oxides are widelyused in the preparation of optical glasses ,glass fibersfor optical purposes ,gasoline-cracking catalysts ,pol-ishing compounds and carbon arcs , and in the ironand steel industriestoremove sulfur ,carbon ,and oth-er electronegative elements fromiron and steel[1].Themain sources of ytterbiumand other heavy rare earthelements are monazite and bastnasite . Withincreasingdemand for rare earth elements ,the separation andpurification of these elements…     

Role of nitric oxide in angiotensin IV-induced increases in cerebral blood flow

Whether a rapid elevation of serum gliclazide concentration in human subjects can be achieved through an acceleration of dissolution of gliclazide from a formulation was examined. A soft gelatin capsule containing PEG 400, PEG 4000, Tween 20 and glycerin was prepared as a formulation that may accelerate dissolution of gliclazide. The in vitro dissolution of gliclazide at pH 7.2 was identical for the soft capsule and conventional tablets, Diamicron and Diberin. However, at pH 1, 2 and 4.0 the dissolution from the soft capsule was more rapid compared to the tablets. When bioavailability parameters were compared following oral administration of the soft capsule and Diamicron to 16 healthy Korean male subjects, the parameters representing the amount of adsorption (i.e. the area under the serum gliclazide concentration vs. time curve up to 24 h, AUC24, and the peak serum concentration Cmax) were not statistically different for both formulations. However, the time required to reach the peak (Tmax) was significantly shorter for the soft capsule than for the Diamicron. Our results, therefore, indicate that a rapid elevation of serum gliclazide concentration following oral administration of a formulation can be achieved by accelerating the in vitro dissolution of gliclazide from the formulation into the acidic buffers. Thus, the rate of gastrointestinal absorption of gliclazide appears to be dependent on its in vivo dissolution rate in gastric fluid. A soft capsule containing a PEG 400 suspension of gliclazide appears to be an appropriate formulation for accelerating the dissolution.     

Crystallization and preliminary crystallographic analysis of an amylopullulanase from the hyperthermophilic archaeon Pyrococcus woesei

The thermostable amylopullulanase from Pyrococcus woesei was crystallized. Crystals, suitable for a crystallographic analysis up to a size of 0.6 mm in their longest dimension, have been obtained by the vapor diffusion method in a solution containing polyethyleneglycol 4000 (PEG 4000), isopropanol, and Tris/Cl- buffer pH 7.5. Crystals grown under these conditions form hexagonal rods and diffract to a maximum resolution of 3 A. The crystals belong to the trigonal lattice type with the spacegroup P3(1)21 or P3(2)21, respectively, have the cell dimensions a = b = 96.8 A, c = 196.2 A, alpha = beta = 90 degrees, gamma = 120 degrees. The crystals have a theoretical packing density of 2.7 A3/Da, assuming one molecule with a molecule weight of 88.8 kDa in the asymmetric unit. Furthermore the self-rotation analysis of the dataset revealed only crystallographic symmetries. The merged native data of two crystals resulted in a 88% complete dataset.     

A sensitive procedure for the quantitation of free and N-(2-hydroxypropyl) methacrylamide polymer-bound doxorubicin (PK1) and some of its metabolites, 13-dihydrodoxorubicin, 13-dihydrodoxorubicinone and doxorubicinone, in human plasma and urine by reversed-phase HPLC with fluorimetric detection

A high-performance liquid chromatographic assay has been developed and validated for the determination in plasma and urine of doxorubicin (DXR) and some of its metabolites released in vivo from an N-(2-hydroxypropyl)methacrylamide (HPMA) polymer containing DXR linked through its aminosugar moiety to the polymer via an oligopeptide spacer (PK1). The method also allows measurement of the DXR still bound to the polymer. Following addition of two internal standards, the free compounds were extracted twice with isopropanol-chloroform (25:75, v/v). The first extraction was performed at physiological pH and the second after buffering at pH 8.4, in order to extract the aglycones and the glycosides, respectively. Determination of total DXR (polymer-bound plus free DXR) was performed, after quantitative acid hydrolysis to release doxorubicinone from free or polymer-bound DXR, by extraction with the same solvent mixture at pH 7.4. In both cases the organic phase was evaporated to dryness; the compounds were then separated by reversed-phase high-performance liquid chromatography (HPLC) under isocratic conditions and quantitated by fluorimetric detection. In the chromatograms all the analytes appeared to be separated at the baseline and no interference from blank human plasma and urine was observed. The suitability of the method for in vivo samples was checked by the analysis of plasma and urine samples obtained from a cancer patient who had received a single intravenous dose of the test compound.     

重金属酸性废水处理的pH值设定

探讨了石灰-硫酸铁三级中和法处理重金属酸性废水过程中pH值的设定。一级中和槽pH值设定为7～8；二级中和槽pH值设定为10；三级中和槽pH值设定为8～9、Fe／As值为20，处理后的废水中重金属离子、砷、氟及pH值均达到废水排放标准。     

氯盐体系铟萃取富集试验

针对氯盐体系铟的萃取进行萃取体系、酸度、萃取剂浓度、相比和时间条件试验,对反萃过程中关键影响因素盐酸浓度进行试验。最佳萃取工艺参数为:有机相30%P204、相比(O/A)=1/3、皂化率60%、初始水相pH=0.5、室温混合5min;铟一级萃取率能够达到97.01%,三级逆流萃取能够稳定达到99.5%。反萃工艺参数为相比10/1、盐酸浓度3mol/L、室温混合5min,一级反萃率75.52%,三级反萃率达到100%。经萃取、洗涤、反萃后,铟回收率达到96.8%。     

Interfacial tension of aqueous two-phase systems containing poly(ethylene glycol) and dipotassium hydrogenphosphate

Liquid-liquid equilibrium (LLE) compositions and interfacial tensions of the aqueous two-phase system containing poly(ethylene glycol) (PEG 4000, average Mr=3500; PEG 6000, average Mr=7500; and PEG 20000, average Mr =20000) and dipotassium hydrogenphosphate were experimentally determined by using a shaking flask method and a drop volume method at 288.15, 298.15 and 308.15 K, respectively.     

Thermal unfolding of the starch binding domain of Aspergillus niger glucoamylase

A fragment of the starch-binding domain (SBDF) of Aspergillus niger glucoamylase was prepared using recombinant DNA techniques, and its thermal unfolding was investigated by high-sensitivity differential scanning calorimetry (DSC). Thermal unfolding of SBDF was found to be reversible at pH 7 as expected from a DSC study of the whole enzyme molecule [Tanaka A. et al., J. Biochem., 117, 1024-1028 (1995)] but not reversible at acidic region. Numerical analysis of the DSC curves showed that the denaturation was two-state, and some of the SBDF molecules were oligomeric (average degree of oligomerization was 1.2) at pH 7. It was suggested that the denaturation temperature of SBDF was lower than that of the starch-binding domain in the whole enzyme molecule by about 4.5 degrees (decrease in the Gibbs energy change was 5.3 kJ mol-1) indicating a possibility that the starch-binding domain is stabilized by glycosylation of the domain itself, or by the highly glycosylated linker region.     

镍电解液用P204萃取除铜

以P204为萃取剂,从镍电解液中萃取除铜。研究了pH、相比(O/A)、P204体积浓度和振荡时间对萃取效果的影响,确定了P204萃取铜的最佳条件。结果表明:随着pH的升高,铜的萃取率增大;相比(O/A)越大萃取分离效果越好;随着P204体积浓度的升高,铜萃取率也相应的升高。室温下P204萃取铜的最佳工艺条件:P204的体积浓度15%,相比(O/A)1∶2,水相初始pH2.0,振荡时间3 min。在此最佳条件下,待处理液的一级萃取率达81.33%。反萃实验中反萃率可达84.97%。     

Reduction Extraction Method for Determining the Enthalpies of Decomposition Reactions of Different Boron Nitride Modifications

Pulsed (7–10 sec) reduction extraction in a helium gas carrier stream has been used for the first time to determine the standard enthalpies and the internal energies of thermal dissociation reactions for various modifications of boron nitride (BN) with and without carbon. The temperature dependences of the weight content of nitrogen extracted from nanosized (4–10 nm) and microsized (<1; 4–5 μm) BN powders in the range 2100–4000 K with a step of ~200 ± 25 K have been established. Nitrogen extraction from layered BN modifications (graphene and graphite structures) begins at 2400–2500 K and reaches 100% at 3500 K. The thermal decomposition curve for nanoand micropowders of dense BN modifications (wurtzite and sphalerite structures) is similar to that for the layered modifications and is shifted toward the high-temperature region by 900 K. The standard enthalpies of decomposition reactions for different BN modifications have been determined: 231 kJ/mole for graphene-like, 249 kJ/mole for graphite-like, 296 kJ/mole forwurtzite-like, and 391 kJ/mole for sphalerite-like modifications.     

Extraction and separation of In(III), Ga(III) and Zn(II) from sulfate solution using extraction resin

The separation of In(III), Ga(III) and Zn(II) from sulfate solution has been studied using an extraction resin containing 2-ethylhexyl phosphoric acid mono(2-ethylhexyl) ester (P507 extraction resin). The effect of pH on the extraction of each metal was determined. Extraction isotherms were then constructed at selected pH. Results show that In(III) is first extracted from aqueous solutions at pH 2.0 using this resin while Ga(III) and Zn(II) are co-extracted at pH 3.0. Their separation can be carried out using HCl of different concentrations as eluants. The saturation adsorption capabilities of indium(III) and gallium(III) were evaluated as 47.2 and 31.0 mg/g or 0.41 and 0.44 mmol/g, respectively. The molar ratio of metal ion: P507 reagent on resin was about 1:3. Loaded resins can be regenerated, and the metals can be recovered selectively. Two fixed-bed columns arranged in-series were successfully used for the separation and recovery of these three metal ions from a multi-component solution.     

Extraction equilibrium of beryllium and aluminum and recovery of beryllium from Egyptian beryl solution using CYANEX 921

Extraction of Be(II) and Al(III) from aqueous sulfate solution by CYANEX 921 (commercial trioctylphospine oxide) in kerosene was separately studied. The parameters affecting the extraction process, such as hydrogen ion, sulfate ion, and CYANEX 921 concentrations, and temperature were investigated. It was found that Be(II) was highly extracted by CYANEX 921 from an aqueous medium of 0.001 M sulfate and pH 9.0, while Al(III) was highly extracted from a similar solution at pH 5.0. Be(II) extraction was found to decrease with temperature (exothermic), while Al(III) extraction increased with temperature (endothermic). The different species that might be extracted are given and discussed. Extraction of Be(II) and Al(III) by purified TOPO under similar experimental conditions showed that purified TOPO gives relatively less extraction, especially for Al(III) in the pH range 4.0–6.0.Based on the obtained results, separation of beryllium from aluminum and recovery of pure beryllium from beryl mineral were studied. Removal of iron as the main interfering ion in the beryl solution was investigated. A flow chart for the Be/Al separation process was developed and applied to recover pure Be(II) from Egyptian beryl.