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  • 1
    ISSN: 1432-069X
    Keywords: Cholesterol sulfate ; Gas-liquid chromatography ; Cyclohexylsilane-bonded phase column ; Recessive X-linked ichthyosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A new gas-liquid chromatographic (GLC) determination of cholesterol sulfate (CS) and dehydroepiandrosterone sulfate (DHEAS) for a biochemical diagnosis of recessive X-linked ichthyosis (RXLI) is described. Although the GLC method for determination of CS is known to be more sensitive than the thin layer chromatographic (TLC) method, the former method has not been widely employed because of its complicated pre-purification steps. The present method allows us to measure the serum levels of CS and DHEAS without tedious purification steps such as multiple conventional column chromatography and preparative thin layer chromatography. Sulfated steroids are rapidly purified with a commercially available mini disposable cyclohexylsilane-bonded phase (CH) column, CH BOND ELUT, and the purified steroids after desulfation are converted to water-resistant tert-butyldimethylsilyl ether derivatives for the GLC analysis on dual 2 m glass columns packed with 2% XE-60 on Chromosorb W. By the present method, serum CS concentrations in RXLI patients were shown to be about 10 times higher than those in patients with ichthyosis vulgaris, carriers of RXLI, and healthy subjects. This method is more suitable not only for a biochemical diagnosis of RXLI but also for studies on the metabolism of sulfated steroids than the previous time-consuming GLC methods.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 42 (1986), S. 462-464 
    ISSN: 1600-5759
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1434-0879
    Keywords: Contraction ; Human seminiferous tubule ; Steroids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of steroids (testosterone, dihydrotestosterone and estradiol) on human seminiferous tubules in vitro were ascertained by recording the intratubular pressure with a servonull micropressure measuring device. We describe here the first response of the human seminiferous tubule to steroids. Testosterone and dihydrotestosterone had a biphasic effect on tubular contractility. Higher doses of both testosterone and dihydrotestosterone induced contractions of the seminiferous tubules whereas lower doses of these compounds induced relaxation. Estradiol (10-9 M to 10-6 M) induced relaxation of the seminiferous tubules in a dose-dependent manner. The results from these experiments suggested that steroids may be involved in the control of contraction of the human seminiferous tubule and may regulate the movement of spermatozoa from the tests.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 246 (1989), S. 169-172 
    ISSN: 1434-4726
    Keywords: Tympanic membrane ; Ultrastructure ; Sensory receptors ; Nerve endings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Encapsulated nerve endings were found in both the subepidermal connective tissue and the lamina propria of a human tympanic membrane. The structure of the corpuscles was round or oval and contained a number of axon terminals with mitochondria and Schwann cell processes. Amorphous materials were present in the intercellular space. These features appear to be advantageous in transmitting mechanical forces on the capsule to the axon terminals and are comparable to the function of a mechanoreceptor. Resultant changes in the shape and stiffness of the tympanic membrane as the result of its dislocation indicate similar changes in the pressure on the corpuscle. The arrangement of the sensory corpuscles suggests that they may play a role in detecting pressure changes in the middle ear cavity.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 246 (1989), S. 210-212 
    ISSN: 1434-4726
    Keywords: Tympanic membrane ; Sensory innervation ; Anesthesia ; Eustachian tube function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In our previous histological studies of the tympanic membrane, we reported the presence of encapsulated nerve corpuscles that are capable of detecting middle ear pressure. Based on these findings, the relation between sensory receptors in the tympanic membrane and tubal function was examined in a clinical study. Tubal function was tested during Valsalva maneuvers and its active equilibration. Function was recorded as a change of the static compliance of the tympanic membrane on an otoadmittance meter. To paralyze the sensory receptors in the tympanic membrane, iontophoresis was used to induce anesthesia of the drum. Forty ears of 20 subjects were tested. All ears were able to equalize positive middle ear pressure without or with a single swallowing. After anesthesia, 13 ears needed more than two swallows and 4 ears failed to equalize middle ear pressure in spite of repeated swallowings. As eustachian tube function changed following anesthesia of the tympanic membranes, a neural connection between sensory receptors in the tympanic membrane and tubual muscles is suggested.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 5 (1987), S. 427-431 
    ISSN: 1573-1111
    Keywords: Cyclodextrin polymer ; solubility method ; complex stability ; NMR spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The complex forming ability of a water-soluble β-cyclodextrin epichlorohydrin, polymer (CDPS) and its different molecular weight fractions was studied and compared with the complexing properties of β-cyclodextrin (βCD) and dimethyl-βCD (DM-βCD). CDPS was separated into two main fractions. CDPS and its fractions formed well soluble inclusion compounds with the studied drugs. The low molecular weight fraction formed rather stable complexes with small guest molecules, the high molecular weight fraction was found to be more efficient in binding larger substrates. Structural studies of furosemide-CD complexes were attempted by NMR spectroscopy.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    International journal of legal medicine 101 (1988), S. 151-159 
    ISSN: 1437-1596
    Keywords: Methamphetamine, toxicological analysis ; Amphetamine, toxicologic analysis ; Metamphetamin, toxikologische Analyse ; Amphetamin, toxikologische Analyse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Description / Table of Contents: Zusammenfassung Es wurde eine neue Methode zur Trennung von optisch aktiven Isomeren (d und l) und der racemischen Verbindung (dl) von Metamphetamin (MAMP) und Amphetamin (AMP) mittels Hochleistungsflüssigkeitschromatographie durch die UV-Methode ausgearbeitet. Wir fanden, daß 40°C in der Auflösung und der Reproduzierbarkeit der MAMP-Isomeren am besten waren. Meßwerte von Isomeren waren 0.116±0.012, 1.082±0.070 und 8.984±0.136 gegenüber den Mischungsverhältnissen (l/d) von 0.111, 1.000 und 9.000. Die Nachweisgrenze von d- und l-Isomeren war jeweils 25 ng. Die Analysenergebnisse menschlicher Haare von zwei Stimulationsmittelkonsumenten zeigten mittels der oben genannten Methode, daß die Haare nur d-MAMP und d-AMP enthielten, welche unter den Isomeren die stärksten pharmakologischen Wirkungen haben. Die Streuung der Analysen von fünf Standard-Materialien, nach Zusatz von 1,000 ng jeder racemischen MAMP und AMP zu menschlichen normalen Kopfhaaren, war weniger als 4%; die Meßwerte von Isomeren gegenüber den Mischungsverhältnissen l/d=1.000, waren 1.040±0.040 bei MAMP und 0.980±0.030 bei AMP. Die Nachweisgrenze der racemischen Verbindung von MAMP und AMP, die in Haaren angehäuft sind, war jeweils 250 ng. Die Analyse der Isomeren von MAMP und AMP durch unsere Methode würde der Aufdeckung von Schmuggelungen und -methoden dienen.
    Notes: Summary Optical isomers (d and l) and racemic compounds (dl) of methamphetamine (MAMP) and amphetamine (AMP), and biologic materials including those substances, could be analyzed by high performance liquid chromatography. Examining the temperature for the analysis, 40°C was the optimal condition in the reproducibility of separated MAMP-isomers. The reproducibility at the temperature did not vary significantly. The measured values of optical isomers were 0.116±0.012, 1.082±0.070 and 8.984±0.136 for the mixing ratios (l/d) of 0.111, 1.000, and 9.000, respectively. The detection limit for both d- and l-isomers was 25 ng. The analytic result of hair specimens from two stimulant abusers by the present method indicates that they contained only d-MAMP and d-AMP, which is believed to have the strongest pharmacologic effect among the optical isomers of MAMP. The coefficient of variation in the analysis of five replicate standards, prepared by adding 1,000 ng each of racemate MAMP and AMP to hair, was less than 4%. The measured value against l/d=1.000 was 1.040±0.040 in MAMP and 0.980±0.030 in AMP. The detection limit for both racemate MAMP and AMP accumulated in hair was 250 ng. The analysis of the optical isomers by our method would contribute to identifying the smuggling routes or the illicit method.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 15 (1986), S. 83-86 
    ISSN: 0148-7280
    Keywords: fertilized mouse eggs ; viability ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Fertilized mouse eggs were centrifuged at 5,000g, 10,000g, 15,000g, and 20,000g for 3 and 10 min or at 25,000g for 10 min. The pronuclei of centrifuged eggs became more distinctive than those of uncentrifuged eggs. The proportion of centrifuged and uncentrifuged eggs that developed to blastocysts was not significantly different. There was also no significant difference in the proportion of live fetuses obtained following the transfer of blastocysts developed from centrifuged and uncentrifuged eggs. This study demonstrated that there is no effect of centrifugation on the subsequent development of mouse eggs.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 16 (1987), S. 243-249 
    ISSN: 0148-7280
    Keywords: centrifugation ; maturation culture ; pronucleus ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Cattle follicular oocytes cultured in vitro for 24-33 h were treated with ethanol to induce artificial activation. When oocytes were cultured for 27-33 h before ethanol treatment, 60-68% of oocytes were activated and were found to have a female pronucleus(ei). In contrast, maturation culture of oocytes for 24-26 h resulted in low activation rates (25-38%). The female pronucleus was formed in the activated oocytes within 8-10 h of incubation after ethanol treatment. And it became visible under interference-contrast microscope by centrifugation for 3 min at 15,000g and 10 min at 20,000g. These results indicate that ethanol treatment is effective for activation of cattle follicular oocytes and that the pronucleus formed in the activated oocyte can be visualized by centrifugation.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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