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  • Life and Medical Sciences  (1,983)
  • Analytical Chemistry and Spectroscopy  (1,947)
  • 1
    Electronic Resource
    Electronic Resource
    Is Multidimensional High Performance Liquid Chromatography (HPLC) an Alternative in Protein Analysis to 2D Gel Electrophoresis? (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 259-265 
    Details
    ISSN: 0935-6304
    Keywords: Proteomics ; protein analysis ; multidimensional HPLC ; ion-exchange chromatography ; reversed phase chromatography ; comprehensive HPLC ; two-dimensional HPLC ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The interactive modes of High Performance Liquid Chromatography (HPLC) of proteins provide a platform for the construction of a multidimensional HPLC system coupled to mass spectrometry. We present a system composed of both anion and cation exchanger columns, in the first dimension, and n-octadecyl bonded 1.5 μm nonporous silica columns in the second dimension. Both columns are operated under gradient conditions. A system suitability test with standard proteins showed that the total analysis can be performed within about 20 minutes. The fractions taken from the ion exchanger column are directly analyzed within one minute on the reversed phase column at a high flow rate. Two reversed phase columns are applied and operated alternatively: while the first column performs the separation within one minute, the analytes leaving the first dimension are enriched in an on-column focusing mode on top of the second column. The sample clean-up and enrichment is performed on a novel type of restricted access cation exchanger column with internal sulfonic acid groups and external diol groups. The columns exhibit a molecular weight exclusion limit for globular proteins of about 15 kDa. Our next studies will be directed towards the analysis of proteins and peptides from extracts of fibroblasts.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Carbon-13 NMR spectra of some labdane diterpenoids (1981)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 17 (1981), S. 301-302 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carbon-13 signal assignments of the labdane diterpenoids phlogantholide-A, its diacetate and isophlogantholide-A are reported. The assignments of the 13C NMR signals of 14-deoxyandrographolide and its diacetate, made earlier, have now been confirmed by lanthanide shift studies on the former and also by 13C spectral studies on anhydroandrographolide diacetate and 14-deoxy-11,12-didehydroandrographolide diacetate.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270170416
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  • 3
    Electronic Resource
    Electronic Resource
    A gas chromatographic mass spectrometric assay for plasma trifluoperazine concentrations following single doses (1982)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 9 (1982), S. 186-190 
    Details
    ISSN: 0306-042X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A gas chromatographic mass spectrometric assay using selected ion monitoring is described which permits the determination of trifluoperazine in plasma at concentrations ranging from 0.078 to 5.0 ng ml-1. It relies on the extraction of trifluoperazine and the internal standard, prochlorperazine or the tetradeuterated analogue of trifluoperazine, form basified plasma with a n-pentane/2-propanol solvent mixture. Following the evaporation of organic solvent, the residue is reconstituted in a small volume of methanol. Suitable aliquots were anlysed by the combined technique of gas chromatography/electron impact mass spectrometry with a data system. The described procedure is specific and enables the quantitation of 78 pg ml-1 of the drug with a coefficient of variation 〈7%. The method has demonstrated sufficient sensitivity to permit pharmacokinetic and bioavailability studies after a single 5 mg oral dose.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200090503
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  • 4
    Electronic Resource
    Electronic Resource
    Ulex europeus type I agglutinin detects carcinoembryonic antigen in extracts of human colorectal carcinoma (1988)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 37 (1988), S. 193-202 
    Details
    ISSN: 0730-2312
    Keywords: colorectal carcinoma ; Carcinoembryonic antigen ; UEA ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Recent interest has focused on fucosylated epitopes expressed on human neoplasms. The plant lectin Ulex europus agglutinin, Type I (UEA) binds fucosylated oligosac-charides, while UEA-reactive substances have a tissue distribution similar to carci-noembryonic antigen (CEA). We sought to determine if UEA reacted with CEA in extracts of fresh primary and metastatic colorectal carcinomas and paired normal tissues. The extracts were electrophoretically transferred to nitrocellulose membranes after the proteins were separated by SDS-PAGE in 10% polyacrylamide gels. The transfer membranes were then stained with peroxidase-conjugated UEA (UEA-P) or antibody to CEA (CEA-P). UEA-P reacted with a 170-190-kDa band in extracts of 22 of 30 primary tumors, 10 of 12 metastases, but only 1 of 5 villous adenomas. UEA-P generally did not react with normal colon or liver extracts. UEA-P also did not bind to 170-190-kDa molecules in Western transfers of a breast carcinoma metastatic to bowel and a focal nodular hyperplasia of liver. CEA-P displayed similar reactivity and detected CEA in a tumor extract negative for UEA. Fucose blocked binding of UEA-P to Western transfers of tumor extracts. CEA-P reacted with a 170-190-kDa substance in tumor extracts eluted with fucose from a column of immobilized UEA. Thus, UEA reacts with fucosylated oligosaccharides on most, but not all, species of CEA and may be a useful adjunct to anti-CEA immunohis-tochemistry.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240370206
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  • 5
    Electronic Resource
    Electronic Resource
    Cephalic circulation in the air-breathing snakehead fish, Channa punctata, C. gachua, and C. marulius (ophiocephalidae, ophiocephaliformes) (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 238 (1994), S. 77-91 
    Details
    ISSN: 0003-276X
    Keywords: Bimodal breathing ; Cardiovascular ; Pseudobranch ; Choroid plexus ; Lentiform body ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The macrocirculation in the head of three air-breathing species of Channa was examined with the aid of vascular corrosion replicas and a scanning electron microscopic study was conducted on the pseudobranch, choroid gland and lentiform body. Two facultative air-breathing murrles, C. punctata and C. gachua, and one obligate air-breather, C. marulius were examined. In all three, the air-breathing organs (ABO) and systemic circulations were in-parallel, and both were in-series with the branchial circulation. Efferent branchial arteries from the first and second gill arches formed the arterial supply to the ABO, whereas the third and fourth arch efferents perfused systemic tissues. Postbranchial blood from the second gill arch also entered the systemic circulation directly via a shunt from the efferent branchial artery to the lateral aorta and via hypobranchial arteries. Vascular specialization to prevent mixing of oxygenated ABO venous and deoxygenated systemic venous blood was evident in arterial, but not venous circuits. Pseudobranchs of C. gachua and C. punctata are tri-lobed, in C. marulius they have numerous lobules. Pseudobranch lamellae are wider and shorter along the axis of blood flow than gill lamellae and folded perpendicular to this axis. Pseudobranch lamellae appear to be modified to minimize their epithelial surface while retaining an extensive vascular endothelial-pillar cell surface area, counter-current amplification is also possible. The choroid gland is an extensive planar counter-current capillary rete. The lentiform body of the eye is a globular capillary rete but there is no evidence of a counter-current circulation. The choroid and lentiform rete may have distinct physiological functions. © 1994 Wiley-Liss, Inc.
    Additional Material: 24 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092380110
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  • 6
    Electronic Resource
    Electronic Resource
    Microcirculation of gills and accessory respiratory organs of the walking catfish Clarias batrachus (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 242 (1995), S. 383-399 
    Details
    ISSN: 0003-276X
    Keywords: Air-breathing fish ; Clarias batrachus ; Vascular shunts ; Microcirculation ; Gills ; Respiration ; Vascular corrosion replicas ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: An ability to extract oxygen directly from the atmosphere enables air-breathing fish to survive otherwise debilitating hypoxic environments. Addition of accessory respiratory organs (ARO) necessitates changes in both the general circulatory system and the microcirculation of the respiratory epithelia. Understanding these modifications provides information on the efficiency of gas exchange organs as well as an indication of the evolutionary processes associated with adaptation to terrestrial habitats.Methods: Vascular organization and structure of gills and ARO of the facultative air-breathing walking catfish Clarias batrachus were examined by scanning electron microscopy of vascular replicas and fixed tissue.Results: Well-developed filaments are present on all four pairs of gill arches and they possess three vascular pathways: respiratory (arterioarterial), nutrient (arteriovenous), and interlamellar (arteriovenous), typical of teleosts. ARO, consisting of gill fans, dendritic organs on the second and fourth gill arch, and the suprabranchial epithelium are derived from gill tissue and retain structural features and arterioarterial vessels similar to gill filaments. Gill and ARO vessels are in parallel with each other, and together they are in series with the systemic circulation. Nutrient and interlamellar vessels are reduced in ARO.Conclusions: Other than the presence of multiple ventral aortas, and an additional vessel connecting the suprabranchial epithelium to the dorsal aorta, there are no vascular shunts or anatomical modifications that indicate spatial separation of flow through the heart or between gills and ARO. However, a mechanism is proposed that would prevent unsaturation of dorsal aortic blood by local myogenic vasoconstriction of gill vessels when the fish is in hypoxic water. Despite considerable differences in the gross features of ARO in Clarias and Heteropneustes fossilis: (Olson et al. 1990 J. Morphol., 203:165), there are striking similarities in vascular organization and respiratory islet structure that suggest these ARO evolved in a common silurid ancestor and were later modified into an everted arborescent organ or inverted air sac, respectively. © 1995 Wiley-Liss, Inc.
    Additional Material: 23 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092420311
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  • 7
    Electronic Resource
    Electronic Resource
    Microcirculation of gills and accessory respiratory organs from the air-breathing snakehead fish, Channa punctata, C. gachua, and C. marulius (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 238 (1994), S. 92-107 
    Details
    ISSN: 0003-276X
    Keywords: Cardiovascular ; Endothelium ; Shunt ; Vascular corrosion replica ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Snakehead fish of the genus Channa have well-developed air-breathing organs (ABO) yet retain their gill arches for respiratory and non-respiratory functions. Alterations in the macrocirculation accompany inclusion of the ABO and appear to enhance gas exchange efficiency (Munshi et al., 1994. Anat. Rec. 238:77-91). In the present study, the microcirculatory anatomy of gill and ABO from two facultative air-breathing Channa, C. punctata and C. gachua, and one obligate air-breather, C. marulius, were examined in detail using scanning electron microscopy (SEM) of vascular corrosion replicas and fixed whole-sectioned tissue. The results show that the circulation in the filaments from the first, second, and third gill arches is similar to that found in water-breathing teleosts. Fourth gill arch microcirculation of C. punctata is not different from the other three, whereas in C. marulius, it has been greatly modified into a network of low-resistance vascular shunts, although remnants of an intralamellar filamental microcirculation remain. The vascular shunts are formed from extensions of afferent and efferent lamellar arterioles and the complete, or nearly complete, loss of a lamellar sinus. The vasculature of the ABO has been highly modified in all species into a coiled-spiral capillary network with a constricted aperture guarding a dilated capillary dome at the epithelial surface. Microvilli are found congregated on the aperture endothelium of C. punctata but they are virtually absent from C. marulius endothelium. Less than 15% of the ABO capillary surface appears to face the epithelium and thereby contributes directly to gas exchange. These findings suggest that the microvascular modifications observed in Channa entail more than a simple increase in the contact surface between ABO vessels and air and they may serve other unknown physiological functions. © 1994 Wiley-Liss, Inc.
    Additional Material: 33 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092380111
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  • 8
    Electronic Resource
    Electronic Resource
    Total leydig cell volume and its estimation in dogs and in models of testis (1972)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 174 (1972), S. 259-264 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The total Leydig cell volume has been determined in 40 dog testes using a histometric point-counting method. In preliminary experiments, the accuracy of the method has been established on specially prepared plasticine models of the testis. The point-counting method has a mean error of ± 7% and the values obtained by it, when statistically analysed, are not significantly different from those determined by direct measurements (p 〉 10% ). Thus, work on the models has provided convincing experimental verification of the method.The Leydig cells constitute about 15% (14.2 to 17.1% ) of the testicular volume in dogs. In absolute terms, it comes out to be 1.56 ± 0.45 ml of Leydig cells per testis. Larger testes contain proportionally greater amount of Leydig cell tissue, the relationship being almost linear. Although very little data is available for comparison, and none perhaps for the dog, it appears from the present study that the total quantity of Leydig cells in this species is essentially the same as in man.Since it allows a reliable estimate of the total Leydig cell volume directly in milliliters per testis, the point-counting method has proved to be much more useful than older methods which merely determined the proportion of Leydig cells in relation to some other testicular component.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091740210
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  • 9
    Electronic Resource
    Electronic Resource
    Antibodies to sperm surface fertilization antigen (FA-1): Their specificities and site of interaction with sperm in male genital tract (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 26 (1990), S. 175-183 
    Details
    ISSN: 1040-452X
    Keywords: Sperm antigen ; Testis ; Blood-testis ; barrier ; Antisperm antibodies ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The fertiization antigen (FA-1) isolated from murine testes demonstrated its dimeric form of 49,000 ± 2,000 molecular weight (M.W.) or a monomer of 23,000 M.W. on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The FA-1 was immunogenic in all three female rabbits tested and raised a high-titer antisera [enzyme-linked immunosorbent assay (ELISA) titers; 1:1,024 to 1:4,096]. The rabbit anti-FA-1 antisera predominantly recognized the dimeric form of 49,000 ± 2,000 M.W. on the Western blot of lithium diiodosalicylate (LIS)-solubilized murine testes. None of the antisera reacted with any somatic tissue, indicating germ-cell specificity of FA-1. To determine the cellular localization of the immunoreactive FA-1, a novel ultrasensitive immunogold-silver staining (IGSS) procedure was developed. The anti-FA-1-lgG showed intense staining in the luminal region of the seminiferous tubules containing spermatids and spermatozoa. No reaction was observed in the peripheral area of the tubules containing Sertoli cells, spermatogonia, leptotene, and zygotene spermatocytes. The biodistribution studies of 125I-labeled anti-FA-1 lgG in mice revealed that the antibodies do not bind to somatic tissues such as blood cell, liver, heart, kidney, muscle, and gastrointestinal tissue and do not transudate into testes nad seminal vesicle. However, the antibodies preferentially transudate into epididymis (especially corpus or cauda regions) and vas deferens to bind to sperm cells. In conclusion, our data indicate that FA-1 can induce an immune response that is germ cell-specific, directed against later stages of spermatogenesis. The antibodies to FA-1 interact with sperm after penetration through epididymis (especially corpus and cauda regions) and vas deferens rather than through testes and seminal vesicles.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080260212
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  • 10
    Electronic Resource
    Electronic Resource
    Identification with liquid chromatography-ionspray mass spectrometry of the metabolites of the enantiomers N-methyl dextrorphan and N-methyl levorphanol after rat liver perfusion (1993)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 22 (1993), S. 226-234 
    Details
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: To gather more information on stereochemical factors in the hepatic disposition of organic cations, mass spectrometry coupled to liquid chromatography was used to determine the identity of the metabolites excreted in bile after isolated rat liver perfusions with the quaternary ammonium derivatives of the enantiomeric drugs dextrorphan and levorphanol. Ionspray mass spectrometry was chosen for its soft ionization and absence of thermal degradation of labile compounds. The drugs were labelled with a stable (2H) isotope and mixed with unlabelled drugs to create an artificial isotope pattern in the mass spectrum and facilitate the recognition of unknown metabolites. In mass spectra that were recorded under normal conditions, fragmentation was absent and metabolites of N-methyl dextrorphan and N-methyl levorphanol were visible as parent-ion ‘doublets’. Collision-induced fragmentation studies were performed to support the identification of the metabolites. For N-methyl dextrorphan the glucuronide, the glutathione conjugate and the glucuronide of the N-demethylated metabolite were found in bile. For N-methyl levorphanol the glucuronide, the glutathione conjugate, the sulphate conjugate and the glucuronide of a hydroxylated N-methyl levorphanol were excreted in bile. Thus a remarkable stereoselectivity occurs in the metabolism of these quaternary ammonium compounds in the rat liver.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200220403
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