bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solid phase extraction and high performance liquid chromatographic determination of dobutamine in plasma of dialysed patients
Authors: Leflour C. , Dine T. , Luyckx M. , Brunet C. , Gressier B. , Cazin M. , Robert H. , Durocher A. , Cazin J. C. 
Published: May 2005

AbstractAn isocratic reversed‐phase high performance liquid chromatographic method has been developed for the determination of dobutamine in the plasma of dialysed patients. A solid phase extraction method with a Sep‐Pak C18 cartridge was used to isolate the drug and isoxsuprine (internal standard) from plasma. The separation was carried out on an ODS‐Hypersil column with 0.1 M phosphate buffer: acetonitrile: methanol (72 : 20 : 8 v/v/v) as the mobile phase. The recovery of dobutamine added to plasma by the extraction procedure was 87 ± 2.3% (mean ± SD). The accuracy and reproducibility of the method were within acceptable limits over the concentration range 0–1000 ng/ mL. Quantification was by fluorescence detection at 275 nm excitation and 310 nm emission wavelengths with a detection limit of 5 ng/ mL for dobutamine. This procedure was applied to ascertain the pharamacokinetics of dobutamine infusion in nine patients with cardiogenic shock and end‐stage renal disease undergoing haemodialysis.
Optical purity determination of thyroxine enantiomers in bulk materials by chiral thin layer chromatography
Authors: Aboul‐Enein Hassan Y. , Serignese Vince 
Published: May 2005

AbstractL‐thyroxine and D‐thyroxine were separated on ligand exchange chiral thin layer chromatographic plates, using a solvent system consisting of acetonitrile:methanol:water 60:15:15 v/v, at a wavelength of 254 nm. The methodology, chiral recognition mechanism (s) involved and its application are discussed.
High‐performance liquid chromatographic assay for the quantitation of nadolol in human plasma using fluorescence detection
Authors: Srinivas Nuggehally R. , Shyu Wen Chyi , Shah Vinod R. , Campbell Dale A. , Barbhaiya Rashmi H. 
Published: May 2005

AbstractA rapid and sensitive HPLC‐fluorescence assay was developed and validated for the determination of nadolol, a β‐blocker, in human plasma. Nadolol and the internal standard (desmethyl nadolol) were extracted from alkalinized plasma into methyl‐tert.‐butyl ether. The organic solvent was evaporated under nitrogen at 40°C. The residue was reconstituted in the mobile phase and injected on to a C18 silica column (25 cm × 4.6 mm i.d.) at a flow rate of 1.4 mL/min. The mobile phase was 0.05 M monobasic ammonium phosphate (pH 4.2) and acetonitrile (84:16, v/v). Fluorimetric detection was performed at excitation 230 nm and emission 330 nm. The nominal retention times were 3.3 and 4.3 min for the internal standard and nadolol, respectively. The lower limit of quantitation was 5 ng/mL and linearity (R2 ≥ 0.994) of the standard curve was demonstrated between 5 and 500 ng/mL. The analysis of quality control (QC) samples at 60, 200 and 400 ng/mL resulted in precision estimates ⩽7.0% relative standard deviation (RSD) for the inter‐assay and ⩽6.3% RSD for intra‐assay. The predicted concentrations of the QC samples deviated <10% from the nominal values. The extraction recovery of nadolol from human plasma was 64%. Nadolol was stable in human plasma at −20°C for at least 5 months and for at least three freeze‐thaw cycles. Nadolol and the internal standard were stable in the autosampler at 5°C for at least 40 h. Overall, the assay was accurate, precise, sensitive, specific and reproducible for the analysis of nadolol in plasma. The validated assay procedure was applied to study the pharmacokinetics of nadolol after administration of single and multiple doses to human subjects.
A sensitive high‐performance liquid chromatographic assay for the cholecystokinin‐b antagonist, CI‐988, in human and monkey plasma
Authors: Hinton Joanna P. , Jennings Kathleen , Johnson Elvin L. , Wright D. Scott 
Published: May 2005

AbstractA sensitive and specific high‐performance liquid chromatographic assay for the non‐peptide cholecystokinin subtype B receptor antagonist, CI‐988, in human and cynomolgus monkey plasma has been developed and validated. The method involves isolation of CI‐988 and internal standard by batch robotic solid phase extraction with a C18 cartridge, liquid chromatographic separation on a C18 column and quantitation by fluorescence detection. The human plasma assay is linear from 0.25 to 500 ng/mL for a 1.00‐mL plasma aliquot. Assay precision for CI‐988 based on human plasma quality control samples was within ±7.2% relative standard deviation with an accuracy of ±5.6% relative error. The monkey plasma assay is linear from 1.00 to 250 ng/mL for a 0.500‐mL plasma aliquot. Assay precision based on monkey plasma quality control samples was within ±11.0% relative standard deviation with an accuracy of ±2.6% relative error.
Isolation and characterization of new porphyrin metabolites in human porphyria cutanea tarda and in rats treated with hexachlorobenzene by HPTLC, HPLC and liquid secondary ion mass spectrometry
Authors: Luo Jinli , Lim Chang Kee 
Published: May 2005

AbstractPorphyrin metabolisms in human porphyria cutanea tarda (PCT) and in rats treated with hexachlorobenzene (HCB) have been studied in detail by high performance thin layer chromatography (HPTLC), high performance liquid chromatography (HPLC) and liquid secondary ion mass spectrometry (LSIMS). The analyses of porphyrin metabolites in the urine, faeces and liver biopsies of patients with PCT have shown that apart from uroporphyrin I and III and their expected decarboxylation intermediates and products, a complex mixture of many other porphyrins are present. The new porphyrins identified are: meso‐hydroxyuroporphyrin III, β‐hydroxypropionic acid uroporphyrin III, hydroxyacetic acid uroporphyrin III, peroxyacetic acid uroporphyrin III, β‐hydroxypropionic acid heptacarboxylic acid porphyrin III, hydroxyacetic acid heptacarboxylic porphyrin III and peroxyacetic acid pentacarboxylic porphyrin III.
Determination of guanase activity in normal and pathological sera by high‐performance liquid chromatography
Authors: Canepari S. , Castellano P. , Cernia E. , Girelli A. M. , Bozza A. 
Published: May 2005

AbstractA simple HPLC assay for serum guanase based on the direct determination of enzymatically formed xanthine was applied to normal and pathological sera. The procedure is sensitive, precise (CV below 5%) and suitable for routine purposes, and the method requires only 50 μL of sample. Using this method the reference range as determined from the sera of 40 healthy adult controls is 0–1.1 U/L. In patients with various liver diseases serum guanase activities were found to be increased 5‐ to 50‐fold compared with the normal mean value.
Determination of salicylic acid in plasma by gas chromatogrphy using steam as carrier gas
Authors: Li Yun‐Hua , Ren Zi‐Hong , Li Xiu‐Lu , Cai Yi‐Feng , Zhai Zheng‐Xing 
Published: May 2005

AbstractA gas Chromatogrphy method using steam as the carrier gas was established for the determination of salicylic acid in plasma. A 0.5 mL plasma sample was mixed with 0.5 mL of 6N HCl and then extracted with 2 mL of dichloromethane. The dichloromethane was evaporated to dryness and the residue was redissolved in 0.5 mL of water and then analysed by gas Chromatogrphy using steam as the carrying gas. The result was calculated by external standardization.
TLC characterization of liposomes containing D‐myo‐inositol derivatives
Authors: Brailoiu Eugen , Huhurez Gabi , Slatineanu Sebastian , Filipeanu Catalin M. , Costuleanu Marcel , Branisteanu Dimitrie D. 
Published: May 2005

AbstractThe thin‐layer chromatographic (TLC) behaviour of liposomes containig inositol phosphates (IPs) was studied. The liposomes contained different concentrations of D‐myo‐inositol 1, 4, 5‐trisphosphate (IP3), D‐myo‐inositol 1, 2, 6‐trisphosphate (α‐trinositol, PP 56, a novel Perstorp Pharma derivative), D‐myo‐inositol 1, 3, 4, 5‐tetrakisphosphate (IP4), D‐myo‐inositol 1, 3, 4, 5, 6‐pentakisphosphate (IP5) and D‐myo‐inositol 1, 2, 3, 4, 5, 6‐hexakisphosphate (IP6). Migration of all liposome batches was compared to that of control liposomes (containing only triple‐distilled water), and to that of free phosphatidylcholine (PC); the same amount of lipid was used in all situations.Thin‐layer chromatography was performed on silica gel as adsorbent. As solvent we used an n‐buthanol: ethanol: water mixture in a 4:3:3 volume ratio. Significant differences were found between PC and all liposome batches, as well as between control liposomes and the ones containing IP3, α‐trinositol, IP4, or IP5, in various concentrations. Liposomes containing IP6 migrate completely differently compared not only to phosphatidylcholine and control liposomes, but also to the ones containing other IPs (<10−3 M). Unlike the other IPs studied, liposome‐entrapped IP6 elicits dose‐independent contractions of the isolated rat aorta. This suggests that liposomes loaded with IP6 undergo, during or after their preparation, physico‐chemical alterations that eventually change their drug‐delivery capacity.
Availabilty of phenylisothiocyanate for the amino acid sequence/configuration determination of peptides containing D/L‐amino acids
Authors: Imai Kazuhiro , Matsunaga Hirokazu , Santa Tomofumi , Homma Hiroshi 
Published: May 2005

AbstractA potential use for phenylisothiocyanate (PITC), the most popular Edman reagent, is presented for analysis of the amino acid sequence and configuration in peptides containing D/L‐amino acids. After derivatization with PITC of the N‐terminal amino acid (L‐Tyr) of an enkephalin analogue, [D‐Ala2, D‐Leu5]‐enkephalin, followed by cleavage/cyclization with trifluoroacetic acid at 50°C for 5 min, the liberated 2‐anilino‐5‐thiazolinone‐L‐Tyr (ATZ‐L‐Tyr) was further treated with 20% aqueous trifluoroacetic acid at 50°C for 10 min. The resultant phenylthiohydantoin (PTH)‐L‐Tyr was then separated on a chiral stationary phase (a penylcarbamoylated cyclodextrin column), retaining its configuration. The residual sequence and configurations of the peptide (D‐Ala‐Gly‐L‐Phe‐D‐Leu) were also determined by separating the corresponding PTH‐D‐ or L‐amino acids on chiral columns. This method may be applicable to an automatic Edman sequence analyzer for the configuration determination of peptides containing D/L‐amino acids.
Red‐band resonance raman spectroscopy of chlorophyll cofactors in photosynthetic proteins
Authors: Lutz Marc 
Published: May 2005

AbstractOnly recently have various methodological approaches been successful in producing Raman spectra of chlorophylls resonantly with their lowest singlet electronic transitions (Qy bands). The information content of these new approaches and their impact on current research on photosynthetic proteins are discussed. It is shown that resonance methods can contribute very valuable data on the dynamics of the primary photophysical events, while preresonance methods are yielding many new data on the structural bases of these events at atomic level. © 1995 John Wiley & Sons, Inc.
Serious case reviews: learning to use expertise
Authors: Brandon Marian , Dodsworth Jane , Rumball Daphne 
Published: May 2005

AbstractWhile undertaking an analysis of 20 serious case reviews for the Welsh Assembly Government, the authors became aware of important, largely unexplored, practice issues with implications for training, service delivery and the role of the lead professional. The reviews were studied using a ‘layered reading’ methodology to ensure that emerging themes were grounded entirely in the reports. In looking beyond the familiar recurring themes and practice failings, findings emerged about the use of expertise in its widest sense. The need for more skilled use of expertise was identified, from external specialists and child protection specialists, and from children, siblings and parents. Professionals from agencies who contribute less routinely to the process of safeguarding children should be consulted as experts and be empowered to play a fuller part. Consultation could often be used prior to, or in place of referral. The barrier to the collation and analysis of relevant information often appeared to be a failure to recognize and understand expertise rather than a lack of communication as often postulated in review reports. Skilled use of expertise and consultation in a coordinated manner could result in more rigorous assessments and promote greater professional trust, confidence and challenge. Copyright © 2005 John Wiley & Sons, Ltd.
Origins of the differences in function of rat adrenal zona glomerulosa cells incubated as intact tissue and as collagenase‐prepared cell suspensions
Authors: Raven P. W. , McCredie E. , McAuley M. , Vinson G. P. 
Published: May 2005

AbstractWhile in vitro incubation of dispersed cell preparations of adrenal cell types has been widely used as an experimental model, few studies have addressed the possibility that the enzymic and mechanical treatments involved may affect tissue functions. Using rat adrenal whole capsule tissue, consisting of glomerulosa cells still attached to the connective tissue capsule together with some fasciculata cells, and dispersed glomerulosa cell preparations formed by a variety of enzymic and incubation treatments, striking differences have been demonstrated between the functions of the various preparations in vitro. Under ACTH stimulation, whole capsules produced (ng per pair ± s.e.) 405 ± 35 ng aldosterone, 650 ± 60 ng 18‐hydroxycorticosterone (18‐OH‐B) and 850 ± 90 ng corticosterone. In cells dispersed by collagenase incubation followed by repeated pipetting and filtration, aldosterone and 18‐OH‐B yields under ACTH stimulation fell to values less than 10% of those produced by whole tissue, whereas corticosterone values were unchanged. Omitting the filtration step gave a less well marked decline in aldosterone and 18‐OH‐B to 50% of intact tissue values. When the tissue was not dispersed after collagenase incubation, aldosterone and 18‐OH‐B outputs were similar in the two preparations. The decline in aldosterone and 18‐OH‐B is not attributable to loss in cell–cell contact alone, since short term culture of collagenase dispersed cells on contracting collagen discs did not restore the capacity to produce these steroids, and a decline in their output also occurred in similar culture of intact capsule tissue. In acute incubations, hyaluronidase had similar effects to collagenase, whereas trypsin, papain and a bacterial protease evoked aldosterone release during the preincubation period, but did not affect subsequent yields of aldosterone and 18‐OH‐B in incubations of dispersed (but not filtered tissue) in the presence of ACTH. Chymo‐trypsin had no effect on preincubation but eliminated subsequent response to ACTH in all incubation conditions. Together with previously published data on the effects of trypsin, the results support the view that in intact rat adrenal glomerulosa tissue, aldosterone and 18‐OH‐B are sequestered into intracellular stores in the form of novel steroid‐protein complexes. These are hydrolysed by trypsin and other preoteases with consequent release of steroid, but are virtually eliminated by conventional methods of cell suspension preparations, using collagenase preincubation with subsequent mechanical dispersal and filtration.
Scanning‐integrating cytophotometric analyses of brain neuronal RNA and acetylcholinesterase in acute soman toxicated rats
Authors: Anthony A. , Doebler J. A. , Bocan T. M. A. , Zerweck C. , Shih T.‐M. 
Published: May 2005

AbstractCytophotometric analyses of RNA and acetylcholinesterase responses of caudate and cerebrocortical neurons of soman toxicated rats were conducted to characterize impairments in regulatory aspects of neuronal metabolism occurring in the acute phase of cholinesterase impairment. There was a severe and dose‐dependent suppression (20–60%) in neuronal acetylcholinesterase activity in both a.m. and p.m.‐treated rats; no diurnal differences were apparent in control acetylcholinesterase levels or neuronal acetylcholinesterase responsiveness to soman toxication. RNA levels, however, were markedly higher in p.m. than in a.m. saline‐treated controls. Soman depressed caudate neuron RNA contents in the afternoon, but not in the morning. Cerebrocortical neuron RNA levels were suppressed in both a.m. and p.m.‐toxicated rats, although this RNA depletion was more severe in the afternoon. These results indicate that soman can elicit marked alterations in neuronal transcriptional‐translational capabilities and that there are diurnal variations in cellular metabolic responsiveness to soman toxication. Although functional relationships between soman‐induced cholinesterase inhibition and RNA depletion remain to be elucidated, depressed RNA metabolism appears to be a maladaptive response preventing rapid regeneration of cholinesterase following poisoning.
The A12 acetylcholinesterase and polypeptide composition of electric organ basal lamina of electrophorus and some torpedinae fishes
Authors: Inestrosa Nibaldo C. , Méndez Bernardita 
Published: May 2005

AbstractBasal lamina (BL) of Torpedo, Discopyge and Electrophorus electric organs was purified in order to establish polypeptide composition and association with acetylcholinesterase (AChE). Results indicate that BL presents a distinct peptide pattern and that the A12 form of AChE is directly attached to it. Comparison of the species studied demonstrated similarities both in polypeptide composition and AChE content of the purified BL. Extractions of BL with solutions of high ionic strength, guanidine–HCl and acetic acid indicated the differential solubilization of various domains of BL polypeptides.
Effects of mitogenic stimulation of lymphocytes on lysosomal enzyme activity
Authors: Olsen I. , Dean M. F. , Muir H. , Smith R. , Jenne B. M. , Hand C. 
Published: May 2005

AbstractChanges in the activities of several lysosomal enzymes were studied during transformation of mouse spleen cells in vitro. The activity of β‐glucuronidase increased during culture in the presence of T or B‐cell mitogens, and lymphoblasts contained higher levels of activity than did small, non‐transformed lymphocytes. Moreover, lymphoblasts in well‐transformed cultures had higher activities than those in poorly‐transformed cultures. The activities of other lysosomal enzymes (N‐acetyl‐β‐glucosaminidase, α‐mannosidase, β‐glucosidase) also increased during mitogenic stimulation, but each at different rates, although aryl sulphatase was unaffected. Such differences may be of importance when lymphocytes are used for diagnosis of inherited lysosomal deficiency diseases.
Lysosomal membrane recovery following labilization by thyroid stimulators
Authors: Neylan D. , Smyth P. P. A. 
Published: May 2005

AbstractLysosomal membrane permeability was assessed by measuring freely available napthylamidase activity in intact preparations of guinea pig thyroid follicular cells following exposure of thyroid tissue to sequential stimulation by two thyroid stimulators, thyrotrophin (TSH) and thyroid stimulating immunoglobulins (TSI). These investigations showed that following labilization by TSH, the lysosomal membranes recovered and were capable of responding to a second thyroid stimulator (TSI). That such recovery represented restabilization of lysosomal membranes was confirmed by the finding that latent naphthylamidase activity was restored without a change in total activity of the enzyme.
Aerobic glycolysis of bone and cartilage: The possible involvement of fatty acid oxidation
Authors: Dunham Jane , Dodds R. A. , Nahir A. M. , Frost G. T. B. , Catterall A. , Bitensky Lucille , Chayen J. 
Published: May 2005

AbstractThe apparent paradox of aerobic glycolysis has been investigated in bone and in cartilage. A new cytochemical procedure for hydroxyacyl dehydrogenase (HOAD) activity showed that the maximal activity of this enzyme in both tissues was equivalent to the maximal activity of glyceraldehyde 3‐phosphate dehydrogenase (GAPD). The sum of these activities gave a measure of the maximum amount of acetyl‐coenzyme A that could be produced. In these tissues, but not in liver which does not exhibit aerobic glycolysis, this summed value exceeded the maximal activity of succinate dehydrogenase (SDH). Consequently, it suggested that where fatty acid oxidation is sufficient to supply all the acetyl‐coenzyme A required for the Krebs' cycle, that derived from fatty acid oxidation may inhibit pyruvate dehydrogenase causing accumulation of pyruvate which must be converted to lactate if pentose‐shunt activity is to be maintained.
Specific molybdenum binding to spectrin subunits
Authors: Mařík T. , Kselíková M. , Bíbr B. , Lener J. 
Published: May 2005

AbstractMolybdenum in the form of its pentavalent complex binds primarily to spectrin when incubated with erythrocytes. Only the band 1 subunit is involved in this interaction thus indicating some structural differences between spectrin subunits.
In vitro cytotoxicity of a glass ionomer cement of a new generation
Authors: Meryon S. D. , Browne R. M. 
Published: May 2005

AbstractThe new glass ionomer dental cement, ChemFil, was found to be moderately cytotoxic when freshly mixed in vitro. This was assessed by a reduction in fibroblast and macrophage counts following 24 h exposure to the material, and by alterations in enzyme levels and enzyme staining kinetics relative to control cultures. Testing of set samples of the material showed that its toxicity decreased rapidly with setting. ChemFil behaved in a manner similar to two older glass ionomers, ASPA and ChemBond, although it was generally slightly less irritant.
Process of the combination of α‐lactalbumin with lysosomes in mammary epithelial cells
Authors: Komine Senichi , Nakanishi Keiko , Anzai Tadashi , Yoshimoto Akio 
Published: May 2005

AbstractWe previously reported that α‐lactalbumin combines with the lysosomal membrane of mammary epithelial cells and that it acts to release lysosomal enzymes. However, the details of this combination within the cells remained undetermined. We now report that 125I‐bovine‐α‐lactalbumin in the medium entered mouse mammary epithelial cells, and about 13 per cent of the α‐lactalbumin that entered the cell bound to lysosomes. About 75 per cent of the α‐lactalbumin that reached the lysosome was tightly bound to the lysosomal membrane. It appears that α‐lactalbumin in the secretory vesicles does not migrate out, because murine and bovine whey did not induce the release of Golgi enzymes in vitro.
Specificity of kirkman‐robbins hepatoma non‐histone chromatin proteins: Electrophoretic and immunological analyses
Authors: Krajewska Wanda M. , Kiliańska Zofia , Lipińska Anna , Klyszejko‐Stefanowicz Leokadia 
Published: May 2005

AbstractThe specificity of Kirkman‐Robbins hepatoma and hamster liver non‐histone chromatin proteins has been studied by comparing polypeptide patterns in polyacrylamide gel electrophoresis and by their immunological activity in the complement fixation test. Non‐histone proteins were separated from DNA with a polyethylene glycol‐dextran mixture and fractionated by hydroxylapatite chromatography into three classes named NHCP1, NHCP2, and NHCP3. Electrophoretic analysis indicated that among the non‐histone proteins of Kirkman‐Robbins hepatoma and hamster liver differences mainly of a quantitative nature can be observed. However, the polypeptides with molecular weight 25 000, 31 000, 36 000, 73 000 in NHCP1; 20 000, 40 000 in NHCP2 and 20 000, 32 000, 38 000, 44 000, 75 000, 80 000 in NHCP3 were found to be specific for hepatoma chromatin. Application of antibodies against NHCP1, NHCP2 and dehistonized chromatin of Kirkman‐Robbins hepatoma revealed that the highest specificity of NHCP2 eluted from hydroxylapatite with 100 mM phosphate buffer at pH 6·8. The NHCP1 of hepatoma shares some common antigenic determinants with analogous proteins of liver. On the other hand non‐histone proteins specific for heptoma dehistonized chromatin can be localized in the NHCP3 and partially in the NHCP1 fractions.