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  • 1
    Electronic Resource
    Electronic Resource
    Electrolyte concentrations in primary and final saliva of the rat sublingual gland studied by micropuncture and catheterization techniques (1971)
    Springer
    Pflügers Archiv 324 (1971), S. 344-360 
    Details
    ISSN: 1432-2013
    Keywords: Rat Sublingual Gland ; Micropuncture ; Electrolyte Transport ; Parasympathomimetic Stimulation ; Sublingualdrüse ; Mikropunktion ; Elektrolyttransport ; Parasympathicomimetische Stimulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The salivary electrolyte concentrations at various secretory rates have been studied in the rat sublingual gland and compared with the concentrations found in acinar-intercalated duct (primary) fluid obtained by micropuncture. The primary fluid had the following composition: [Na]=126±1.6 (S.E.M.,n=39) mEq/l; [K]=11.9±1.2 mEq/l (n=39); [Cl]=99.3±2.3 mEq/l (n=33). The Na and K concentrations differed significantly from those of plasma and from those observed previously in the primary fluid of rat parotid and submaxillary glands. The composition of primary fluid was not altered by carbachol stimulation. After carbachol stimulation, the final saliva, like that of the human but unlike that of the cat and dog sublingual gland, was hypotonic and the electrolyte concentrations showed flow-rate dependence. At the lowest flow rate the Na concentrations averaged 24.6±3.9 mEq/l (n=25) which fell first to a minimum and then rose to a plateau of about 60 mEq/l as flow rate increased to a maximum. The excretory curve showed no tendency to approach the concentrations seen in primary saliva. The K excretory curve was typical of that seen in most other salivary glands, having high concentrations at low flow rates which fell towards a plateau above primary fluid levels as flow rate increased. The salivary bicarbonate concentration was always above that in plasma; it tended to rise to a plateau of about 48 mEq/l at the highest flow rates. This concentration is probably greater than that present in primary fluid although the primary levels have not been measured directly. The results are best interpreted in terms of a modified two-stage hypothesis. First a primary, Na-rich, K-poor secretion is formed in the acinar-intercalated duct region whose composition, although decidedly not plasma-like, is constant irrespective of the degree of gland stimulation. Then, secondarily, this fluid is modified during passage along the striated and excretory ducts by processes of Na reabsorption and K and HCO3 secretion. These secondary transport processes are not transport-maximum-limited but appear to increase with increasing degree of stimulation resulting in a phenomenon which could be termed acinar-tubular balance. Although it has not proven possible to micropuncture striated ducts in the rat submaxillary or parotid glands, in the sublingual gland we were able to do so in a few cases. For the first time we are able to offer direct proof that these ducts do contain hypotonic fluid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00592462
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  • 2
    Electronic Resource
    Electronic Resource
    Amicroperfusion investigation of the effects of a sympathomimetic and a parasympathomimetic drug on water and electrolyte fluxes in the main duct of the rat submaxillary gland (1971)
    Springer
    Pflügers Archiv 327 (1971), S. 303-323 
    Details
    ISSN: 1432-2013
    Keywords: Parasympathomimetics ; Sympathomimetics ; Electrolyte Transport ; Submaxillary Gland ; Microperfusion ; Parasympathicomimetica ; Sympathicomimetica ; Elektrolyttransport ; Glandula submaxillaris ; Mikroperfusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Previous studies on the intact rat submaxillary gland led to the hypothesis that sympathomimetic and parasympathomimetic drugs, in addition to stimulating glandular production of primary saliva, also stimulated secondary secretion of K and HCO3 by the striated and excretory ducts. It was postulated that parasympathomimetics were more effective stimulants than sympathomimetics atthe primary level but atthe secondary level the two types of drug had actions that were of approximately the same magnitude and that, when administered together, the effects of the drugs were additive. To test this hypothesis the effects of a parasympathomimetic drug (carbachol) and a sympathomimetic drug (isoproterenol) on nett electrolyte transport and transepithelial electrical potential differences were studied in the perfused main duct of the rat submaxillary gland. It was found: 1. That both carbachol and isoproterenol stimulated ductal secretion of bicarbonate irrespective of the electrolyte composition of the perfusion fluid. 2. Both drugs stimulated a parallel nett secretion of potassium when the perfusion fluid contained a low concentration of NaCl. 3. When the lumen contained a high concentration of NaCl, ductal Na reabsorption and K secretion were reduced and HCO3 secretion was accomplished partly in exchange for chloride and partly in parallel with K secretion. 4. In supra-maximal doses the effects of both drugs were of the same order of magnitude and when administered together the effect was always greater than that which could be produced by the same doses of either drug alone. It is concluded that, during pharmacological stimulation of the submaxillary gland, stimulation of ductal secretion of K and HCO3 did indeed occur and that such an occurrence could account for anomalies previously observed in the electrolyte excretory patterns of the intact gland undergoing parasympathomimetic and sympathomimetic stimulation. Since the electrolyte excretory patterns found in saliva collected after nerve and pharmacological stimulation are quite similar it was felt that stimulation of ductal K and HCO3 secretion probably also occurred in this and other salivary glands during nerve stimulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00588450
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  • 3
    Electronic Resource
    Electronic Resource
    The effects of carbachol on water and electrolyte fluxes and transepithelial electrical potential differences of the rabbit submaxillary main duct perfusedin vitro (1973)
    Springer
    Pflügers Archiv 341 (1973), S. 131-142 
    Details
    ISSN: 1432-2013
    Keywords: Carbachol ; Parasympathomimetic Drug ; Sodium Conductance ; Submaxillary Gland ; Microperfusion ; Electrolyte Transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of carbachol on transepithelial potential difference and transepithelial nett electrolyte transport has been studied in the rabbit submaxillary main duct perfusedin vivo andin vitro with bicarbonate saline. The two preparations function similarly, reabsorbing Na, Cl and water and secreting K. In control ducts nett Na reabsorption was 683±55 nmol · cm−2 · min−1 and K secretion was 31.2±2.4 nmol · cm−2 · min−1. Nett water reabsorption was 970±71 nl · cm−2 · min−1 and the hydraulic conductivity was (14.0±1.6)×10−6 ml · cm−2 · s−1 · atm−1. The mean transepithelial potential difference was 13.1±0.8 mV (lumen negative) and, assuming no active transport of Cl, the partial conductance of the duct to Cl was (12.7±2.6)×10−2 mho · cm−2. Carbachol,in vivo andin vitro, caused partial depolarization of the transepithelial potential difference and reduction of nett Na and Cl reabsorption. It was without effect on duct K and HCO3 transport.In vitro, the drug was effective in concentrations as low as 10−7 M and perhaps lower. Atropine was able completely to block the effects of carbachol present at twice the atropine concentration. The results are consistent with the hypothesis that carbachol acts in some way to reduce the sodium conductance of the luminal face of the duct epithelial cell, this response being secondary to an undefined primary action of carbachol on the interstitial face of the cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00587320
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  • 4
    Electronic Resource
    Electronic Resource
    Stimulation by organic solvents and detergents of conversion of L-sorbose to L-sorbosone by Gluconobacter melanogenus IFO 3293For proceedings papers in this series see refs. 1 and 2. (1975)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1473-1483 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Treatment of Gluconobacter melanogenus IFO 3293 cells with benzene, carbon tetrachloride, cyclohexane, deoxycholate, toluene, or xylene stimulated their conversion of L-sorbose to L-sorbosone two- to threefold. The degree of stimulation depended upon the length of exposure time to the agent and the age of the G. melanogenus cells. A rapid decrease in viability of the cells and degradation of cell RNA was noted after treatment with the effective agents. The G. melanogenus cells were unable to absorb L-sorbose actively after toluene treatment.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260171008
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  • 5
    Electronic Resource
    Electronic Resource
    Conversion of L-sorbose to L-sorbosone by immobilized cells of Gluconobacter melanogenus IFO 3293 (1976)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 18 (1976), S. 217-237 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Gluconobacter melanogenus IFO 3293 cells capable of converting L-sorbose to L-sorbosone were immobilized in polyacrylamide gel. The preferred polymer composition for high activity and stability was determined to contain a total monomer concentration of 7.2% and 16.6% crosslinking agent. No significant differences in optimal conditions for conversion, e. g., pH and temperature, were found in comparison with free cell suspensions. However, in the absence of L-sorbose, the thermal stability of immobilized cells was lower. After the initial loss, the conversion activity of immobilized cells increased, possibly due to lysis, and this increase was related to the polymerization conditions and the incubation temperature for the L-sorbose conversion.The enzymatic activity and stability of the immobilized cells also depended on the physical form of the gel and the aeration levels. Addition of electron acceptors or addition of L-sorbosone to the medium reduced, while addition of neomycin, ampicillin, chloramphenicol, and tetracycline increased the stability of the enzymatic activity.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260180208
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  • 6
    Electronic Resource
    Electronic Resource
    Enzymatic hydrolysis of lignocellulosic biomass from Onopordum nervosum (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 32 (1988), S. 341-344 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Some properties of the cellulolytic complex obtained from Trichoderma reesei QM 9414 grown on Solka floc as carbon source and its ability to hydrolyze the lignocellulosic biomass of Onopordum nervosum Boiss were studied. The optimum enzyme activity was found at temperatures between 50 and 55°C and pH ranging from 4.3 to 4.8. Hydrolysis of 4-nitropnenyl-β-D-glucopyranoside (4-NPG) and cellobiose by the β-glucosidase of the complex, showed competitive inhibition by glucose with a Ki value of 0.8 mM for 4-NPG and 2. 56 mM for cellobiose. Enzymatic hydrolysis yield of Onopordum nervosum, evaluated as glucose production after 48 h, showed a threefold increase by pretreating the lignocellulosic substrate with alkali. When the loss of glucose incurred by de pretreatment was taken into account, a 160% increase in the final cellulose to glucose conversion was found to be due to the pretreatment.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260320311
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  • 7
    Electronic Resource
    Electronic Resource
    Chemiluminescence immunoassay. Ian Weeks, Comprehensive Analytical Chemistry. Volume XXIX Elsevier Science Publishers, Amsterdam (1992), 294 pages, Dfl. 295.00, ISBN 0-444-89035-1 (1993)
    New York : Wiley-Blackwell
    Journal of Bioluminescence and Chemiluminescence 8 (1993), S. 331-331 
    Details
    ISSN: 0884-3996
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bio.1170080607
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