bluuebunny/crossref_metadata_2025_split huggingface dataset:
A model of molecular electronics based on the concept of conjugated lonic–hydrogen bond systems
Authors: Karasev V. A. , Luchinin V. V. , Stefanov V. E. 
Published: May 2005

AbstractA new model of lmolecular electronics is proposed as an alternative to the ‘soliton logic’ developed by Carter. The model is based on the principles of continuity of conjugated ionic–hydrogen bond systems (CIHBSs) in the construction of supramolecular structures and conjugation through the hydrogen bond in energy transduction. It is presumed that these principles are realized in biostructures. The Concept implies a symmetrica oligomeric organisation of supramolecular structures and an oscillatory mode of their functioning. The basic architecture and basic elements have been identified. The basic architecture is determined by periodic CIHBSs. The latter have been analysed in proteins, nucleoproteids and biomembranes. The basic elements contain groups capable of building in CIHBSs. Charge generators, valves and other basic elements contain groups capable of building in CIHBSs. Charge generators, valves and other basic elements have been distinguished among biomolecules. Oligomeric enzymes have been suggested as functional prototypes of molecular processors–multivibrators where CIHBSs form Feedback loops and Provide energy recuperation. Technologcal aspects of designing molecular electronic devices on CIHBS principles have been considered. The most challenging and complicated problem is the creation of supramolecular structures with properties which can be specified in advance. Synthesis of membrane two‐dimensional active media capable of storing and processing information in the mode of parallel fluxes is suggested as the most promising route for the fabrication of biochips.
The autoimmune features of acute transverse myelopathy
Authors: Abramsky Oded , Teitelbaum Dvora 
Published: May 2005

AbstractLymphocytes from patients with acute transverse myelopathy (ATM) were shown to undergo a specific and significant transformation when cultured in vitro in the presence of either the central nervous myelin basic encephalitogenic protein (BE) or the peripheral nerve myelin P2 protein. A similar pattern of response was demonstrated in acute disseminated encephalomyelitis and in acute myeloradiculitis. Lymphocytes from patients suffering from other autoimmune neurological disorders or other neurological diseases affecting the spinal cord showed no response to these immunologically related antigens, which have previously been found to have the capacity of inducing experimental allergic encephalomyelitis, either alone or with experimental allergic neuritis, when injected into animals. The specific in vitro response to BE and P2 suggests that in vivo sensitization of lymphocytes to such self‐antigens occurs in ATM and that a cell‐mediated, probably postinfectious autoimmune mechanism may be an important factor in the pathogenesis of the disease.
The ultrastructure of the sural nerve in Pompe's disease
Authors: Goebel Hans H. , Lenard Hans G. , Kohlschütter Alfried , Pilz Hartmut 
Published: May 2005

AbstractThe sural nerve of a 9‐month‐lod infant with Pompe's disease revealed lysosomal and free cytoplasmic glycogen in almost every cell type. Glycogen was combined with lipofuscinlike material in Schwann cells of unmyelinated axons. Proliferation of axonal constituents indicated mild damage to axons.
Proximal peroneal nerve conduction velocity: Recording from anterior tibial and peroneus brevis muscles
Authors: Devi Sarala , Lovelace Robert E. , Duarte Neuza 
Published: May 2005

AbstractDifficulties in calculating the motor nerve conduction velocity of the peroneal nerve arise when the extensor digitorum brevis is completely atrophied and does not respond to stimulation. In these patients, conduction velocity in the proximal fibers of the peroneal nerve can still be calculated by recording from proximal muscles such as the anterior tibial and peroneus brevis. We established normal values by a simple standardized method using 34 subjects.
Neuropathology of sanfilippo syndrome
Authors: Ghatak Nitya R. , Fleming D. Frank , Hinman Alanson 
Published: May 2005

AbstractThis report describes neuropathological observations in an 11‐year‐old patient with Sanfilippo syndrome (SS). The cerebrum was selectively atrophic, with remarkable sparing of the cerebellum. The existing neurons throughout the cerebrum contained various types of membranous cytoplasmic bodies (MCBs), frequently with special predilection for dendrites. Neuronal population was normal in the cerebellum, with massive accumulation of MCBs in the Purkinje cell dendrites and little or no accumulation in the perkiarya. Synaptic contacts were frequently observed on the distended dendrites. Additional findings included storage of vacuoles and granular material in the pericytes and meningeal cells and finely lamellated inclusions in the ependyma and choroid plexus cells. Preferential involvement of the dendrites might provide a morphological explanation for the severe mental retardation in SS.
Amplified luminometric assays of alkaline phosphatase using riboflavin phosphates
Authors: Harborn Stuart , Eggelte Henny J. , Benson Suzanne M. , Rabin Brain R. 
Published: May 2005

AbstractAn asasy for alkaline phosphatase is described which is based on the hydrolysis of riboflavin phosphates (5′FMN or 4′FMN) to produce riboflavin. This is converted to 5′FMN using riboflavin kinase, and then asayed using the bacterial bioluminescent system from Vibrio harveyi or V. Fischeri. The most sensitive assay is obtained using 4′FMN, which can measure less than 20 amol after a 1‐hour incubation.
Total bile acids in hyperlipidaemic serum determined by bioluminescent and spectrophotometric methods
Authors: Lekhakula Somsong , Boonpisit Sasiprapa , Amornkitticharoen Boonthum 
Published: May 2005

AbstractA simple, rapid and sensitive bioluminescent method has been used to measure total bile acids in hyperlipidaemic serum. We found that the levels of total bile acids in hypertriglyceridaemic and hypercholesterolemic sera determined by a spectrophotometric method were four‐fold higher than those measured by the bioluminescent method (6.73 ± 4.07 μmol/l (mean ± SD) by bioluminescent and 26.10 ± 13.42 μmol/l by the spectrophotometric method). There was no difference in total bile acid levels between these two methods for normal serum (4.72 ± 3.38 μmol/l by bioluminescence and 4.49 ± 3.27 μmol/l by the spectrophotometric method).
Enzymatic synthesis and chromatographic purification of lignan glucuronides
Authors: Brunner G. , Tegtmeier F. , Kirk D. N. , Wynn S. , Setchell K. D. R. 
Published: May 2005

AbstractEnterolactone, enterodiol and secoisolariciresinol were conjugated with glucuronic acid by solubilized rabbit liver microsomal UDP‐glucuronyltransf erase. The monoglucuronide conjugate of all three substrates was formed and its identity confirmed by nuclear magnetic resonance (NMR) spectroscopy. Analytical high pressure liquid chromatography (HPLC) and NMR spectroscopy indicated conjugation with glucuronic acid to occur at several positions in the molecule. The enzymatic conjugation was monitored by analytical capillary isotachophoresis (ITP). The Km‐values for enterlactone, enterodiol, and secoisolariciresinol were calculated to be 0.30, 0.23, and 0.22 mmol/l respectively.
Isolation and sequencing of a new biologically active peptide from human lung carcinoma
Authors: Hsi Kuo‐ling , Wu Shih‐xiang , Chen Zhong‐guang , Guo Xiu‐yue , Tsou Kang 
Published: May 2005

AbstractA biologically active peptide designated hLCP has been isolated and purified to homogeneity from human lung carcinoma by means of acidic extraction and successive chromatography on Sephadex G‐50, Toyopearl HW‐40 F and reverse‐phase high performance liquid chromatography columns. Analysis showed that peptide consists of thirteen amino acids. Primary structure of hLCP has been deduced by double‐coupling Edman degradation combined with enzyme digestion as H‐Ser‐Pro‐Pro‐Asp‐Gly‐Lys‐Lys‐Glx‐Ser‐Ala‐Asp‐Val‐Lys‐OH. hLCP possesed significant excitatory activity on an electrical stimulation induced contraction. No hLCP could be detected in normal lung tissue. The possibility of using hLCP as a biochemical marker in the clinic for the early detection of lung carcinoma is being investigated.
Packing materials suitable for rapid, analytical, low‐pressure chromatography of haemoglobins on midget columns
Authors: Ersser R. S. , Barlow G. B. , Drew R. G. , Hjelm M. 
Published: May 2005

AbstractRapid, quantitative, chromatographic separations of mixtures of human haemoglobins have been performed on short (5 – 20 mm) columns of packing material. The desirable characteristics of suitable column packing materials are illustrated and discussed. Simple, inexpensive, manually operated equipment can be used for the analysis, since the specifically designed midget columns generate little back pressure (10 – 30 lb/in2) when eluted at constant flow rates up to 2 mL/min. Cation exchange Chromatography on bonded silicas has been used for the detection of pathological haemoglobinopathies. Separations similar to the HPLC procedures are possible with the correct selection of buffer composition. It also compares favourably with the methods in common clinical use employing electrophoresis on cellulose acetate. Both ion‐exchange and affinity methods for the estimation of glycated haemoglobins have been developed and are compared.
Chromatographic studies of human lung elastin digestion products obtained by leucocyte elastase: Comparison between newborn and adult soluble fragments
Authors: Smyrlaki Marie , Davril Monique , Hayem Annette 
Published: May 2005

AbstractHuman insoluble elastin was prepared from newborn lungs and digested by leucocyte elastase. The soluble fragments were compared to those obtained from adult lung elastin in a previous work (Smyrlaki et al., 1986).Gel filtration on a Bio‐Gel P‐100 column of newborn elastin allowed the separation of fraction F1N (Mr's 30 000–10 000) which was eluted later than the excluded fraction F1A (Mr's 80 000–30 000) previously isolated from adult elastin. The difference in the sizes of the large peptide fragments originating from both elastins was also shown on SDS‐PAGE.Reversed phase HPLC was performed on a C18 column using a multi‐step gradient elution procedure. Different patterns were observed for the high (F1N) and the low (F2N) molecular size fragments of newborn elastin. The same peak distribution was obtained with adult elastin. Comparison of the amino acid compositions of the most retained peaks (3, 4 and 5), derived from fractions F1N and F1A, showed analogies for the contents of the major nonpolar amino acids and crosslinks. Thus, this procedure allowed the separation of typical fragments of elastin which might be released in vivo by leucocyte elastase during pulmonary diseases.
Quantitative determination of adriamycin in rat hepatocytes using a volatile extraction buffer, HPLC and fluorescence detection
Authors: Mahdadi R. , Pommery N. , Pommery J. , Lhermitte M. 
Published: May 2005

AbstractA rapid and sensitive isocratic technique is described for the determination of concentrations of adriamycin and two of its metabolites, adriamycinol and adriamycinone, in freshly isolated rat hepatocytes. The drugs are easily and efficiently extracted from the cells with an organic mixture (chloroform–n‐butanol) after proteolytic digestion with trypsin. Mean recoveries from spiked culture medium cell suspension are greater than 96%. The within run and day‐to‐day coefficients of variation are less than 7.5%.
Thin‐layer chromatography—the forgotten alternative for the quantitative determination of steroids
Authors: Golf S. W. , Graef V. , Schiller J. Th. , Hischer H. , Funk W. 
Published: May 2005

AbstractWe have developed a high performance thin layer chromatography (HPTLC) system for quantitative determination of androgens, corticosteroids, mineralocorticoids and gestagens on silicagel KG‐60 HPTLC‐plates with different solvent systems. A complete separation of androgens, gestagens and metabolites was achieved with dichlormethane/cyclohexane/acetone (70:25:5). Corticosteroids, mineralocorticoids and their derivatives were completely separated with diethylether/isooctane/isopropanol (70:25:5). The quantitative in situ fluorescence determination was carried out after post‐chromatographic derivatization with cinnamic aldehyde, 4‐dimethylaminobenzaldehyde and sulfuric acid. The sensitivity of detection was found between 500 pg and 1 ng per spot.The steroid metabolism as catalysed by rat liver microsomal oxidoreductases was measured by these procedures, and was compared with determination of steroids by gas chromatography (GC). According to HPTLC, steroids were reduced by NADPH‐5α‐reductase (EC 1.3.1.4) in the order progesterone > testosterone > aldosterone > cortisol > corticosterone. The enzyme activities as measured by HPTLC agree well with those obtained by GC (r = 0.94). When turnover of enzyme assays, speed of determination, detection limit, application to labile steroids and costs of steroid determination are considered, all points speak in favour of HPTLC.
The effect of storage on rat tissues and human plasma amino acid levels determined by HPLC
Authors: Bottiglieri T. 
Published: May 2005

AbstractTissue concentrations of the amino acids tryptophan, methionine, valine, phenylalanine, isoleucine and leucine were determined in rat liver, skeletal muscle and brain tissue and human plasma. The effect of storage at −20°C for up to 21 days was examined. Significantly elevated levels after 7 and 21 days of storage were observed in liver and brain tissue but no changes were found in muscle and plasma. Minimal changes occurred in liver tissue stored up to 6 hours at −4°C. This study emphasizes the need for rapid deporteinization of tissues to avoid changes in the free pool of amino acids.
Development of a selective clean‐up method using immobilized antibody and its application to HPLC and GC/MS determination of a carbacyclin derivative, CS‐570, in plasma
Authors: Nakagawa Akihiko , Matsushita Yoko , Muramatsu Shigeki , Tanishima Yukimi , Hirota Takashi , Takasaki Wataru , Kawahara Yukinori , Takahagi Hidekuni 
Published: May 2005

AbstractMethods for the determination of CS‐570, a chemically stable prostacyclin analogue, in plasma were developed by using an immobilized antibody column followed by fluorescence HPLC and GC/MS. The CS‐570 antibody, obtained from rabbit plasma by giving CS‐570–BSA for a few months, was coupled to Sepharose 4B and used as extraction phase for sample clean‐up and extraction of the drug. A plasma sample was applied to this column, washed with water and the drug was eluted with 90% acetonitrile. 0.02% (w/v) 9‐anthryldiazomethane (ADAM) was added to the extract to form a fluorescent derivative. The CS‐570–ADAM adduct exhibited high sensitivity when applied to HPLC with fluorescence detection and column switching. The detection limit was 1 ng/mL when 1 mL of plasma was available. Additionally, a pentafluorobenzyltrimethylsilyl derivative of CS‐570 showed excellent sensitivity when determined by capillary GC interfaced to negative ion chemical ionization MS using a stable isotope labelled analogue as an internal standard.
Purification of streptococcal protein g expressed by Escherichia coli by high performance liquid affinity chromatography using immobilized immunoglobulin G and albumin
Authors: Falkenberg Cecilia , Björck Lars , Åkerström Bo , Nilsson Staffan 
Published: May 2005

AbstractA one‐step HPLC method was developed for the purification of protein G, a cell wall molecule from group C and G streptococci with immunoglobulin G‐ and albumin‐binding properties. Lysed Escherichia coli bacteria infected with lambda‐phages containing the protein G gene from group G streptococci were used as a starting material for the preparations. The lysate was applied to a column with immobilized human immunoglobulin G or human serum albumin. Protein G was selectively bound and eluted at pH 2.0. A 750‐fold purification was achieved. Sodium dodecylsulfate + polyacrylamide gel electrophoresis showed that the highly purified protein G consisted of three sets of doublets with the apparent molecular weight of 64 and 67, 56 and 58, and 45 and 47 kilodaltons, respectively. A specific method for quantitation of small amounts of protein G was developed and used for specific tracing of the protein after the affinity chromatography. Goat polyclonal antibodies were bound to an antigen coated to the plastic walls of microtiter plates, causing the Fc‐region of the immunoglobulins to be directed outwards. Unknown samples of protein G were then allowed to compete with radio‐iodinated protein G (solid phase radioassay) or protein G coupled to alkaline phosphatase (enzyme linked sorbent assay) for the Fc‐regions.
Quantitative determination of propranolol in plasma and pharmaceutical preparations by agar‐based cation‐exchange chromatography utilizing the native anion groups in the agaropectin moiety
Authors: Zelikman Ilya , Hjertén Stellan 
Published: May 2005

AbstractA new cost‐effective method for determining the amount of total propranolol (free and protein‐bound) in plasma samples and the amount of the drug in tablets and injection solutions has been developed. The method is based on cation‐exchange chromatography at pH 8.5 on an inexpensive column of agar, the native sulfate (and carboxylic) groups of which interact with the positively charged propranolol (this interaction is reinforced by the ‘aromatic adsorption’ characteristic of the agar matrix). The method can be used for quantitative analyses at both low (1 × 10−2 mg/L) and high (5 × 103 mg/L) concentrations of the drug. For analyses of plasma and tablets—but not for injection solutions—extraction of the propranolol is required. The extraction time was 6 min. On a 6(ID) mm × 9 mm agar column the run time was less than 10 min.
The determination of selenomethionine in selenium yeast by cyanogen bromide gas chromatography
Authors: Ouyang Zheng , Wu Jiang 
Published: May 2005

AbstractA new method for the determination of bonded selenomethionine in selenium yeast by gas chromatography is established. Bonded selenomethionine is rapidly and precisely determined by measuring CH3SeCN released during the reaction of selenoprotein with CNBr (CNBr‐GC method). Conditions for the reaction and chromatography are described. The results of CNBr‐GC are compared with those obtained by acid hydrolysis/ion exchange chromatography. This new method has the advantage of being accurate, sensitive and selective.
Analysis of leukotrienes by liquid chromatography/electrochemistry after conversion to dinitrobenzoate derivatives
Authors: Steffenrud Steffen , Salari Hassan 
Published: May 2005

AbstractA sensitive liquid chromatography method has been developed using electrochemistry for the determination of leukotrienes in biological fluids. Biological specimens are treated with 3,5‐dinitrobenzoyl chloride in acetonitrile which undergoes rapid reaction with hydroxyl groups of non‐peptidic leukotrienes in the presence of pyridine and with amino groups of peptidic leukotrienes in the presence of potassium tetraborate buffer. The resulting dinitroben‐zoate derivatives of leukotrienes are highly electroactive, suitable for reduction or oxidation at moderate potentials by an electrochemical detector. In reductive mode at −0.7 V or oxidative mode at + 1.15 V potentials, the lower limits of detection for leukotriene derivatives were approximately 8±3 pg and 70 ± 16 pg respectively, with a signal‐to‐noise ratio of 5 to 1. This method was applied to the detection of leukotrienes in plasma, nasal and bronchial fluids of patients with asthma.
HPLC separation and characterization of chlorin derivatives with intact ring V from acid degradation products of silkworm excrement crude chlorophyll mixture
Authors: Hu Longqin , Xu Deyu 
Published: May 2005

AbstractA reversed‐phase HPLC system with 88% methanol in 1 M ammonium acetate buffer pH 5.35 as the mobile phase on an ODS column was used to analyse pheophorbides a, a', b, b' and pyropheophorbides a and b. Pyropheophorbides a and b were found in samples obtained from silkworm excrement but not from spinach leaves though the preparation methods used were the same. This difference suggests that chlorophylls undergo metabolism in the body of silkworm to give pyrochlorophyll derivatives.
Rapid purification of detergent‐solubilized bovine hormone‐sensitive lipase by high performance hydrophobic interaction chromatography
Authors: Nilsson Staffan , Holm Cecilia , Belfrage Per 
Published: May 2005

AbstractHormone‐sensitive lipase (HSL), the enzyme controlling the rate of adipose tissue lipolysis and also possibly involved in the regulation of steroidogenesis, has been purified from bovine omental adipose tissue. Partially detergent‐solubilized, delipidated and purified HSL was obtained through step‐elution at conventional DEAE ion‐exchange chromatography, followed by concentration on hydroxylapatite. High performance hydrophobic interaction chromatography (HPHIC) on phenylsilica then resulted in an increase of HSL protein purity from 2% to more than 70%. Final purification of the enzyme to apparent homogeneity (>95% protein purity), concentration and removal of most of the detergent was obtained by high performance cation exchange chromatography on Mono S. At least 0.5 mg of highly stable HSL was obtained from 5 kg of bovine omental fat within four working days. The purified lipase had a lower specific activity than previously reported for the corresponding rat enzyme but the preparations have proved very useful for enzyme structure studies and as an antigen.
Determination of thiols and disulfides in normal rat tissues and hamster pancreas treated with N‐nitrosobis(2‐oxopropyl)amine using 4‐(aminosulfonyl)‐7‐fluoro‐2, 1,3‐benzoxadiazole and ammonium 7‐fluoro‐2, 1,3‐benzoxadiazole‐4‐sulfonate
Authors: Toyo'oka Toshimasa , Furukawa Fumio , Suzuki Takashi , Saito Yukio , Takahashi Michihito , Hayashi Yuzo , Uzu Sonoko , Imai Kazuhiro 
Published: May 2005

AbstractBiological thiols and disulfides in rat and hamster tissues were simultaneously determined by HPLC‐fluorescence detection using 4‐(aminosulfonyl)‐7‐fluoro‐2, 1,3‐benzoxadiazole (ABD‐F) and ammonium 7‐fluoro‐2,1,3‐benzoxadiazole‐4‐sulfonate (SBD‐F). The coefficients of variation (CV) of the method for reduced glutathione (GSH) and oxidized glutathione (GSSG) in liver and for cysteine (CySH) and cystine (CySSCy) in kidney were less than 3.1%. In 11 tissues of Wistar rats (liver, spleen, heart, lung, stomach, bladder, ovary, uterus, adrenal, kidney and pancreas), only CySH, CySSCy, GSH and/or GSSG were detected. Other thiols and disulfides were at extremely low levels in all samples. Both concentrations of CySH and CySSCy in the livers of old rats (111 weeks old, F344) were significantly higher than those of young rats (8 weeks old) (CySH, 0.246 ± 0.099 vs 0.130 ± 0.020 μmol/g; CySSCy, 0.051 ± 0.027 vs 0.013 ± 0.002 μmol/g). Administration of N‐nitrosobis(2‐oxopropyl)amine (BOP), a selective carcinogen of hamster pancreatic cancer, to Syrian golden hamsters (38 weeks old) resulted in the increase in the pancreas of GSH to a level 19 times as high and of GSSG to a level 14 times as high as those in untreated hamsters (GSH, 1.173 ± 0.272 vs 0.062 ± 0.017 μmol/g; GSSG, 0.155 ± 0.063 vs 0.011 ± 0.001 μmol/g).
High performance liquid chromatographic determination of fluvoxamine in human plasma
Authors: Pommery J. , Lhermitte M. 
Published: May 2005

AbstractA method has been developed for the separation and measurement of fluvoxamine in human plasma by high performance liquid chromatography. The method uses metapramine as an internal standard and provides a limit of detection of about 1.5 ng/mL for fluvoxamine. At a concentration of 25 ng/mL, fluvoxamine could be measured within a coefficient of variation of ±5.82 of the mean and at 100 ng/mL within a CV of ±2.78 of the mean. The method has been applied to the analysis of plasma from patients undergoing fluvoxamine therapy.