Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-1440
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary An androgen producing tumour of the testis was removed from a boy with pseudopubertas praecox. Urinary excretion of total 17-oxosteroids, androsterone and aetiocholanolone, 11-oxy-17-oxosteroids (particularly 11β-hydroxy-androsterone), pregnandiol, pregnantriol and oestrogens were abnormally high before operation, and had decreased to normal after operation. After incubation of tumour slices with glucose alone androst-4-en-3,17-dione and 11β-hydroxyandrost-4-en-3,17-dione were found; after incubation with androst-4-en-3,17-dione: 11β-hydroxyandrost-4-en-3,17-dione, testosterone and adrenosterone, but no oestrogens were found; after incubation with desoxycorticosterone: corticosterone and 17α-hydroxycorticosterone. A large amount of androst-4-en-3,17-dione was found in Vena spermatica blood, as well as 17α-hydroxyprogesterone, 11β-hydroxyandrost-4-en-3,17-dione and testosterone. The biochemical and morphological aspects are discussed in relation to the clinical manifestations of the tumour. The tumour had the morphological appearance of a Leydig cell adenoma and also showed a high rate of androgen secretion. The finding of 11β-hydroxylase activity in the tumour shows that it possessed a characteristic usually found only in adrenocortical cells. The tumour was conceivably derived from atypical Leydig cells. This type of Leydig cell adenoma is compared with the bilateral tumour-like enlargement of the testis, which is ocassionally observed in congenital adrenogenital syndrome. The common and contrasting characteristics of the two growths are discussed.
    Notes: Zusammenfassung Bei einem Knaben mit einer Pseudopubertas praecox wurde ein androgenproduzierender Hodentumor entfernt. Präoperativ war die Harnausscheidung der gesamten 17-Ketosteroide, von Androsteron und Ätiocholanolon, der 11-Oxy-17-Ketosteroide, insbesondere von 11β-Hydroxy-androsteron, von Pregnandiol, Pregnantriol sowie der Oestrogene abnorm erhöht und fiel nach der Operation auf Normwerte ab. Nach Inkubation von Glucose allein mit Tumorschnitten wurden 11β-Hydroxy-Δ 4-androstendion undΔ 4-Androstendion gefunden, nach Inkubation vonΔ 4-Androstendion: 11β-Hydroxy-Δ 4-androstendion, Testoseron und Adrenosteron, jedoch keine Oestrogene, nach Inkubation von Desoxycorticosteron: Corticosteron und 17α-Hydroxy-desoxy-corticosteron. Im V. spermatica-Blut wurden große MengenΔ 4-Androstendion, ferner 17α-Hydroxy-progesteron, 11β-Hydroxy-Δ 4-androstendion und Testosteron nachgewiesen. Die biochemischen und morphologischen Gesichtspunkte sowie die klinischen Auswirkungen des Tumors werden diskutiert. Morphologisch hatte der Tumor den Aspekt eines Leydigzell-Adenoms. In Übereinstimmung hiermit wurde eine hohe Sekretion von Androgenen festgestellt. Durch den Nachweis einer 11β-Hydroxylase-Aktivität zeigte der Tumor jedoch gleichzeitig eine Eigenschaft, die sonst nur NNR-Zellen zukommt. Der Tumor wird vermutungsweise von atypischen Leydigzellen abgeleitet. Diese Art von Leydigzell-Adenom wird der beidseitigen tumorartigen Hodenvergrößerung, die gelegentlich beim angeb. adrenogenitalen Syndrom beobachtet wird, gegenübergestellt. Die gemeinsamen und unterschiedlichen Eigenschaften der beiden Wucherungen werden besprochen.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Communications in mathematical physics 40 (1975), S. 197-213 
    ISSN: 1432-0916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract The thermodynamic limit is taken using a sequence of regions all the same shape as a given region ω of volume |ω|, with a specified distribution of normal field component on ∂ω. We show that with magnetostatic interactions the limiting free energy density is bounded above by jhen where $$\bar f$$ (ϱ,B) is the free energy density for a system of density ϱ in a uniform external fieldB and the “inf” is taken over all divergence-free fieldsB with given normal component on ∂ω and all densities ϱ(x) compatible with particle number constraints of the form $$\int\limits_{\Gamma _i } {\varrho (x)d^3 x = \left| {\Gamma _i } \right|\varrho _i } $$ where Γi is a sub-region of ω. A physical argument suggests that this upper bound is the true thermodynamic limit, and that it takes account demagnetization effects. Electrostatic interactions can be treated similarly.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of statistical physics 17 (1977), S. 47-60 
    ISSN: 1572-9613
    Keywords: Surface phase transitions ; adsorption isotherms ; dense fluids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We derive adsorption isotherms for an adsorbate of hard-sphere particles with “sticky” interactions at any fluid density being adsorbed onto a plane, “sticky” surface. The theory is based on the Percus-Yevick theory for bulk fluids and explicitly includes the equilibrium between the adsorbed fluid and the bulk adsorbate. The theory predicts a surface condensation at low temperatures and low bulk densities in good agreement with surface condensations found in experimental studies of adsorption of gases onto graphite. An approximate law of corresponding states for these transitions is developed. At higher bulk densities and room temperatures, the adsorption isotherms can show a maximum, in accord with recent experimental work.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of statistical physics 21 (1979), S. 659-667 
    ISSN: 1572-9613
    Keywords: Ornstein-Zernike equation ; Baxter's factorization ; softcore ; Yukawa closure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A model for simple fluids is proposed in which the radial distribution function has a parametric form appropriate to a soft-core fluid for interparticle separationr ⩽ R, whereR is some range parameter. Forr 〉 R, the direct correlation function is assumed to be of Yukawa form. The Ornstein-Zernike equation is solved for this system, yielding the radial distribution and the total correlation function for the entire range of interparticle separation. Methods of relating the model fluid to a real fluid by assigning values to the parameters are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...