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: 1432-0428
    Keywords: Ciglitazone ; C57BL/6J-ob/ob mice ; C57BL/KsJ-db/db mice ; β-cell granulation ; electron microscopy ; rough endoplasmic reticulum ; Golgi apparatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Pancreases of treated and control male C57BL/6J-ob/ob and C57BL/KsJ-db/db mice were evaluated by qualitative and morphometric microscopic techniques to determine the effects of chronic ciglitazone treatment on the morphology of β cells and surface area and number of pancreatic islets. The β cells of treated ob/ob and db/db mice displayed moderate to heavy granulation whereas most β cells of untreated obese and diabetic mice were extensively degranulated. Although moderate proliferation of the rough endoplasmic reticulum and Golgi apparatus was evident in some β cells of treated db/db mice, both groups of treated ob/ob and db/db mice displayed an improved pattern of insulin synthesis and storage. In contrast, the β cells of untreated ob/ob and db/db mice were in a severe state of stress which was indicated by extensive hypertrophy of the rough endoplasmic reticulum, Golgi apparatus and mitochondria. Some β cells of untreated db/ db mice also displayed lysosome aggregates indicative of early stages of necrosis. Morphometric analysis revealed that the surface area of islets of treated ob/ob mice was significantly smaller in comparison with that of untreated ob/ob mice. Since the surface area of islets of treated C57BL/6J-+/? mice (lean littermates of ob/ob mice) was less than that of treated ob/ob mice, the progression of islet hypertrophy in the obese mice was probably arrested or attenuated but not to the level of the treated +/? mice. The number of pancreatic islets was significantly greater in treated than in untreated db/ db mice. A majority of the islets of untreated db/db mice were atrophie and consisted of acinar and endocrine cells whereas most of the islets of treated db/db mice appeared to be intact and unremarkable. The results of this study suggest that ciglitazone is an effective hypoglycaemic agent which may directly or indirectly promote β-cell regranulation and an improved pattern of insulin synthesis and storage in ob/ob and db/db mice. However, in treated db/db mice, there still was some evidence of stress in the β cells. Overall, the prolonged treatment with ciglitazone also seemed to inhibit the hypertrophy of islets in ob/ob mice and protect the structural integrity and viability of islets in db/db mice.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1420-9071
    Keywords: HIV RNase H ; inhibitors ; novenamines ; micelles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Few inhibitors of the RNase H function associatesd with the HIV-1 reverse transcriptase have been discovered to date. We observed that three novenamines, U-34445, U-35122, and U-35401, are specific inhibitors of the HIV-1 RT RNase H function. All three compounds are strong amphiphiles and contain one ionizable group. Hence, a priori, in aqueous solutions the inhibitors might exist in at least four different physical states, namely protonated monomers, ionized monomers, protonated micelles and ionized micelles. The three inhibitors all yielded anomalous dose-response curves, indicating that the four molecular species have different inhibitory potentials. In order to identify the inhibitory species, the amphiphilic properties of these compounds were studied. It was established that in alkaline solutions, around pH 8, all compounds are ionized and form micelles at concentrations above their CMC. Both the protonated and the ionized forms of these molecules from stable insoluble monomolecular layers at the air/water interface. The anomalies of the dose-response curves can be resolved by taking into account the fact that, in solution, the relative proportion of these molecules in each physical state depends on the pH and on their analytical concentration. Thus interpreted the results indicate that RNase H is inhibited only by the ionized micellar form of these compounds and not by their monomeric form. Around their pKa (∼pH5) the three componds reproducibly form uniformly sized, self-emulsified colloidal particles that may be used as an efficient drug delivery system.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 22 (1976), S. 840-851 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The dynamic behavior of aerosol size distributions under the influence of coagulation and growth by heterogeneous condensation of gaseous species is studied. Analytical solutions are obtained to the integro-differential equation governing the aerosol size distribution density function. Two modes of coagulation (constant and linear coagulation constants) and two modes of condensation (growth independent of particle volume and linearly dependent on particle volume) are considered. The interaction of the two growth mechanisms on aerosol size distributions is elucidated.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 11 (1965), S. 891-897 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Integral conversion catalytic data have been studied by nonlinear estimation to determine whether the Langmuir-Hinshelwood heterogeneous catalytic models are more valid than the simpler homogeneous noncatalytic forms, and whether it is possible to discriminate among models. The experimental system chosen for this study was the vapor phase dehydration of ethanol. Data for a similar hypothetical catalytic system were also generated and analyzed to highlight the effects arising in the ethanol dehydration case.Nonlinear estimation is shown to be a valuable adjunct in the study of reaction kinetics and mechanism. For the hypothetical system, the correct model was found to provide the best fit to the data. Linear regression, coupled with the usual criterion that models are acceptable if all parameter estimates are positive, did not provide this discrimination. For the experimental system of ethanol dehydration, as corroborated by the hypothetical system, such problems as degeneracy of the heterogeneous rate equations and comparatively large errors in measurement are shown to be obscuring factors in determining the best model. When these effects are involved, it is doubtful that the Langmuir-Hinshelwood equations are more warranted than the simpler homogeneous forms.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 32 (1992), S. 305-309 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Superconductor/polymer composites were prepared by mixing powders representing the Y-Ba-Cu-O and Bi(Pb)-Sr-Ca-Cu-O systems with high-density polyethylene. Their electrical resistivities were measured as a function of temperature. By controlling the powder preparation techniques, it was possible to fabricate composites with superconductive transition to zero resistivity in the Bi(Pb)-Sr-Ca-Cu-O system. These composites can be fabricated in certain desired shapes.
    Additional Material: 8 Ill.
    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...