Showing papers by "University of Jena published in 1995"

Cloning and characterization of a g-protein-activated human phosphoinositide-3 kinase

Abstract: Phosphoinositide-3 kinase activity is implicated in diverse cellular responses triggered by mammalian cell surface receptors and in the regulation of protein sorting in yeast. Receptors with intrinsic and associated tyrosine kinase activity recruit heterodimeric phosphoinositide-3 kinases that consist of p110 catalytic subunits and p85 adaptor molecules containing Src homology 2 (SH2) domains. A phosphoinositide-3 kinase isotype, p110 gamma, was cloned and characterized. The p110 gamma enzyme was activated in vitro by both the alpha and beta gamma subunits of heterotrimeric guanosine triphosphate (GTP)-binding proteins (G proteins) and did not interact with p85. A potential pleckstrin homology domain is located near its amino terminus. The p110 gamma isotype may link signaling through G protein-coupled receptors to the generation of phosphoinositide second messengers phosphorylated in the D-3 position.

Delineating hydrological response units by geographical information system analyses for regional hydrological modelling using PRMS/MMS in the drainage basin of the River Bröl, Germany

Abstract: A modified concept of hydrological response units (HRUs) for regional modelling of river basins using the PRMS/ MMS model is presented. The HRUs are delineated by geographical information system (GIS) analysis from physiographic basin properties such as topography, soils, geology, rainfall and land use using a thorough hydrological systems analysis. The HRUs, once classified by GIS analysis, preserve the three-dimensional heterogeneity of the drainage basin. The River Brol basin (A = 216km 2 ), Rheinisches Schiefergebirge, Germany was selected to apply the concept. In total, 23 HRUs were delineated and tested with the PRMS/MMS model using a 20-year hydrometeorological daily database. The hydrological systems analysis revealed that interflow is the dominant flow process through the basin's slopes and the major contribution to groundwater recharge and river runoff. This was accounted for by parameterizing the HRUs in the model control file to drain their surplus water not used for satisfying the demand of evapotranspiration to a common conceptual subsurface storage. This storage was simulated by interflow drainage to the groundwater aquifer in the valley floor, which in turn drained to the channel network. The PRMS/MMS model simulated the observed daily discharge very well and the fit was described by a daily correlation coefficient of r = 0.91. The NASIM and HSPF models using different means to represent the basin's physiographic heterogeneity were applied to the Brol basin as well, but did not achieve this correlation. The HRU concept was found to be a reliable method for regional hydrological basin modelling and allows spatial up- and downscaling. Future research on this concept will focus on incorporating the variable precipitation distribution into the classification of HRUs and on the hydrodynamic routing of the modelled discharge. Additionally, satellite imagery must be used for classifying land use in macroscale drainage basins.

Optical properties of ocular fundus tissues--an in vitro study using the double-integrating-sphere technique and inverse Monte Carlo simulation.

Abstract: Various models have been published calculating the light transport at the ocular fundus either for interpretation of in vivo reflectance measurements or for the prediction of photocoagulation effects. All these models took the absorption spectra of the pigments located at the ocular fundus, melanin, haemoglobin, xanthophyll, and the photoreceptor pigments, into account. However, light scattering inside the single fundus layers has not been investigated in detail and was, therefore, neglected in the calculations or only considered by very rough approximations. This paper presents measurements on specimens of retina, retinal pigment epithelium, choroid, and sclera using the double-integrating-sphere technique. Absorption coefficients, scattering coefficients, and anisotropy of scattering were calculated by an inverse Monte Carlo simulation from the measured collimated and diffuse transmittance and diffuse reflectance. Conclusions are drawn for the interpretation of fundus reflectance measurements, which are a useful tool in diagnostics and photocoagulation dosimetry.

General relativistic gravitational field of a rigidly rotating disk of dust: solution in terms of ultraelliptic functions.

Abstract: In a recent paper we presented analytic expressions for the axis potential, the disk metric, and the surface mass density of the global solution to Einstein's field equations describing a rigidly rotating disk of dust. Here we add the complete solution in terms of ultraelliptic functions and quadratures.

Developmental regulation of Na+ and K+ conductances in glial cells of mouse hippocampal brain slices

Abstract: The relative contribution of voltage activated Na+ and K+ currents to the whole cell current pattern of hippocampal glial cells was analyzed and compared during different stages of postnatal maturation. The patch-clamp technique was applied to identified cells in thin brain slices obtained from animals between postnatal day 5 and 35 (p5-35). We focused on a subpopulation of glial cells in the CA1 stratum radiatum which most probably represents a pool of immature astrocytes, termed "complex" cells. These cells could not be labelled by O1/O4 antibodies, but some of the older cells were positively stained for glial fibrillary acidic protein (GFAP). In the early postnatal days, the current pattern of the "complex" cells was dominated by two types of K+ outward currents: a delayed rectifier and a transient component. In addition, all cells expressed significant tetrodotoxin (TTX)-sensitive Na+ currents. During maturation, the contribution of delayed rectifier and A-type currents significantly decreased. Furthermore, almost all cells after p20 lacked Na+ currents. This down-regulation of voltage gated Na+ and K+ outward currents was accompanied by a substantial increase in passive and inward rectifier K+ conductances. We found increasing evidence of electrical coupling between the "complex" cells with continued development. It is concluded that these developmental changes in the electrophysiological properties of "complex" glial cells could be jointly responsible for the well known impaired K+ homeostasis in the early postnatal hippocampus.

Glial cells in the mouse hippocampus express AMPA receptors with an intermediate Ca2+ permeability.

Abstract: Recently, we could demonstrate the 'complex' glial cells in mouse hippocampal slices express glutamate receptor changes of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate subtypes. In the present study, we further characterized this glial receptor. Since voltage-clamp control is imperfect and diffusion barriers hinders the quantitative analysis of the receptor currents in situ, the patch-clamp technique was applied to glial cells acutely isolated from the mouse hippocampal CA1 stratum radiatum subregion. A concentration-clamp technique was used which enabled very fast exchange of the extracellular solutions. Thus, it was possible to characterize the transient receptor currents with high time resolution. Application of L-glutamate, AMPA and L-homocysteate induced rapidly activating and fast desensitizing receptor currents in the suspended glial cells. In contrast, kainate induced non-desensitizing currents. The corresponding dose-response curve revealed a half-maximum of current activation at 350 microM. The current/voltage relationship of the kainate-evoked response was linear with a reversal potential at approximately 9 mV. Analysis of the reversal potential in solutions containing high concentrations of CaCl2 confirmed earlier in situ data by demonstrating significant Ca2+ permeability of the glial glutamate receptor channels in the hippocampus. The kainate-induced receptor currents were markedly increased by cyclothiazide, a substance which selectively potentiates glutamate receptors of the AMPA subtype. We conclude that glial cells of the juvenile hippocampus mainly express heteromeric high-affinity AMPA receptors. Most probably, the receptor channels are assembled from the low Ca(2+)-permeable glutamate receptor-2 subunit together with Ca(2+)-permeable AMPA-preferring subunits.

Trap distribution for charge carriers in poly(paraphenylene vinylene) (PPV) and its substituted derivative DPOP-PPV

Abstract: In this paper, we present measurements of the charge-carrier transport in the conjugated polymer poly(paraphenylenevinylene) (PPV) and its substituted derivative poly(1,4-phenylene-1,2-diphen- oxyphenyl vinylene) (DPOP-PPV) by using the time-of-flight technique. A method for evaluating the experiments, based on Fourier transform techniques, is presented to calculate the density of localized states from the measured photocurrent within a multiple trapping model. The transport properties of DPOP-PPV can be described by a conventional hopping mechanism, where nearly every monomer acts as a trap. At room temperature, the effective mobility for holes in DPOP-PPV is in the range of ${10}^{\mathrm{\ensuremath{-}}4}$ ${\mathrm{cm}}^{2}$/V s, whereas for PPV, a value of less than ${10}^{\mathrm{\ensuremath{-}}8}$ ${\mathrm{cm}}^{2}$/V s can be estimated.

Struktur, Eigenschaften und NMR-spektroskopische Charakterisierung von Cp2Zr(Pyridin)(Me3SiCCSiMe3)†

Abstract: Die Substitution des THF-Liganden in Cp2Zr(THF)(Me3SiCCSiMe3) (1) durch Pyridin ergibt den Komplex Cp2Zr(η1-NC5H5)(Me3SiCCSiMe3) (3). Im Gegensatz zu 1 ist Komplex 3 stabil in Kohlenwasserstoffen. In temperaturabhangigen 1H- und 13C-NMR-Spektren zeigt 3 in Losung dynamisches Verhalten durch eine Rotation des Alkin-Liganden. Zusatzlich tritt beim Losen von 3 in Pyridin ein Austausch zwischen koordinierten und freien Pyridin-Molekulen auf. Die Kristallstrukturanalyse von 3 belegt eine tetraedrische Koordinationsgeometrie am Zirkonium-Zentrum bestehend aus den Cp-, Alkin- und Pyridin-Liganden. Der Komplex 3 reagiert wie Verbindung 1 mit Wasser und Kohlendioxid zu gleichen Produkten. Structure, Properties, and NMR Spectroscopical Characterization of Cp2Zr(pyridine)(Me3SiCCSiMe3) Displacement of the THF ligand in Cp2Zr(THF)(Me3SiCCSiMe3) (1) with pyridine yields Cp2Zr(η1-NC5H5)(Me3SiCCSiMe3) (3). Unlike 1, the complex 3 is stable in hydrocarbon solvents. According to the temperature dependent 1H and 13C NMR spectra, the structure of complex 3 in solution is dynamic due to a rotation of the alkyne ligand. In addition, when 3 is dissolved in pyridine an easy exchange between coordinated and free molecules of pyridine takes place. In the solid state complex 3 displays a tetrahedral coordination sphere at the zirconium center composed of Cp ligands, alkyne and pyridine as shown by an X-ray structure analysis. The complex 3 reacts readily with water and carbon dioxide giving the same products as in the case of 1.

Immunohistological localization of regulatory peptides in the midgut of the female mosquito Aedes aegypti

Abstract: The midgut of the female mosquitoAedes aegypti was studied immunohistologically with antisera to various regulatory peptides. Endocrine cells immunoreactive with antisera to perisulfakinin, RFamide, bovine pancreatic polypeptide, urotensin 1, locustatachykinin 2 and allatostatins A1 and B2 were found in the midgut. Perisulfakinin, RFamide and bovine pancreatic polypeptide all react with the same, about 500 endocrine cells, which were evenly distributed throughout the posterior midgut, with the exception of its most frontal and caudal regions. In addition, these antisera recognized three to five neurons in each ingluvial ganglion and their axons, which ran longitudinally over the anterior midgut, as well as axons innervating the pyloric sphincter. The latter axons appear to be derived from neurons located in the abdominal ganglia. Antisera to two different allatostatins recognized about 70 endocrine cells in the most caudal area of the posterior midgut and axons in the anterior midgut whose cell bodies were probably located in either the brain or the frontal ganglion. Antiserum to locustatachykinin 2 recognized endocrine cells present in the anterior midgut and the most frontal part of the posterior midgut, as well as about 50 cells in the most caudal region of the posterior midgut. Urotensin 1 immunoreactivity was found in endocrine cells in the same region as the perisulfakinin-immunoreactive cells, but no urotensin-immunoreactive axons were found in the midgut. Double labeling experiments showed that the urotensin and perisulfakinin immunoreactivities were located in different cells. Such experiments also showed that the locustatachykinin and allatostatin immunoreactivities in the most caudal area of the posterior midgut were present in different cells. No immunoreactivity was found in the mosquito midgut when using antisera to corazonin, allatotropin or leucokinin IV. Since these peptides have either been isolated from, or can reasonably be expected to be present in mosquitoes, it was concluded that these peptides are not present in the mosquito midgut.

Effects of Disease‐Related Cues in Alcoholic Inpatients: Results of a Controlled “Alcohol Stroop” Study

Abstract: We tested the hypothesis that alcoholics develop a disease-related attentional bias. Therefore, alcohol-related, but task-irrelevant, words should cause a specific perceptual-processing bias. We investigated this by using a special color-naming task. We subjected 40 male alcohol-dependent inpatients and 40 healthy male controls (matched according to age and verbal IQ) to a modified card version of the Stroop color-naming task that consisted of a neutral and an alcohol word condition ("Alcohol Stroop"). Alcoholic inpatients performed significantly poorer than the control group under the critical experimental condition (color-naming of disease-related words), as compared with the noncritical condition (color-naming of neutral words; p = 0.03). Concerning the possible neuropsychological impairment of the patients, no effects could be found on the reaction time of the "Standard Stroop" using only neutral words (i.e., color-naming of incongruent color words administered without time limitation). The information processing bias on the "Alcohol Stroop" thus qualifies as a cognitive process, which is independent from putative neuropsychological deficits of alcoholic patients and might represent an essential feature of alcoholic psychopathology. The "Alcohol Stroop" contributes to the experimental psychopathology of alcoholism.

Photothermal measurements on optical thin films

Abstract: An overview of the application of the photothermal technique for optical as well as thermophysical characterizations of thin films is given. The peculiarities of this technique are discussed in some detail, and selected important results are pointed out. Emphasis is placed on the influence of both residual absorption and randomly distributed inhomogeneities in thin films on their laser-damage resistance.

Theoretical studies and spectroscopic investigations of ground and excited electronic states of thiophene oligomers

Abstract: CNDO/S calculations including single and double excited configurations were performed on thiophene oligomers n T with 2–6 monomer units. In contrast to the results on linear polyenes only single excited configurations are necessary to explain the experimental results. The theoretical energies for the lowest 1 1 B states are in good agreement with the low energy absorption origins and the high energy fluorescence maxima and with the 1 1 B state energies observed at low temperature. The results show that the 2 1 A state lies above the 1 1 B state for 2T–6T. Transient absorption bands measured by picosecond spectroscopy could be assigned to transitions between 1 1 B and higher calculated 1 A states of all studied oligomers n T.

Surface charge density on spherical silica particles in aqueous alkali chloride solutions

Abstract: Experimental data concerning the dependence of the surface charge density of AEROSIL 300 in aqueous alkali chloride solutions on pH are analyzed under application of two different models for a spherical electrical double layer. Data for the alkali ions Li+, Na+, K+, Rb+ and Cs+ are included at five electrolyte concentrations. In the first model a counterion binding in combination with a pure diffuse spherical double layer is considered; here, a good agreement between the recalculated plots and the experimental data is found for low electrolyte concentrations (c<0.05 mol/l) only. The second model with a charge free Stern layer and without counterion binding seems to be applicable for higher electrolyte concentrations also. Furthermore the surface charge density constants from the second model agree better with those published and determined with other models or experimental methods.

Genetic variability in Gibberella fujikuroi and some related species of the genus Fusarium based on random amplification of polymorphic DNA (RAPD).

Abstract: One of the most important rice pathogens is Fusarium moniliforme (perfect stage: Gibberella fujikuroi), the causal agent of the super-elongation (“bakanae”) disease. Thirty-seven strains of this species from different geographical regions were analyzed for their ability to produce gibberellins (GA) and for genetic relatedness by random amplified polymorphic DNA (RAPD). All GA-producing isolates showed nearly identical RAPD patterns using 51 oligonucleotide nona- and deca-mers as arbitrary primers. On the other hand, large differences between GA-nonproducing isolates were obtained. Comparison of the RAPD patterns with those of the tester strains of the six known mating populations (A,B,C,D,E,F) of G. fujikuroi showed that all producer strains belong to mating population C and all nonproducer isolates to other mating populations. Evidence for the usefulness of the RAPD technique to distinguish between mating populations was provided by sexual crossings. Consensus phylogenetic trees based on RAPDs were constructed by the Phylogenetic Analysis Using Parsimony (PAUP) system. In combination with morphological analysis, RAPD can distinguish between different species of the genus Fusarium. These investigations may find an application in the diagnosis of unknown Fusarium spp. and in distinguishing isolates of G. fujikuroi within the section Liseola.

On the influence of volume currents and extended sources on neuromagnetic fields: a simulation study.

Abstract: The influence of volume currents on the magnetic field is an important question in magnetoencephalography since the spherical volume conductor is still widely used for source localization. In theory, the magnetic field of a radial dipole in a homogeneous sphere is zero. In realistic models of the head, the field is suppressed when compared with a tangential dipole. To determine the influence of the volume currents, this suppression ratio (magnetic field of the radial dipole divided by the field of the tangential dipole) needs to be quantified. Large-scale finite element method models of the human head and the rabbit head were constructed and the suppression ratio was computed. The computed suppression value of 0.28 in the rabbit head was similar to the previously measured experimental value. In the human head, an average suppression ratio of 0.19±0.07 was found for different regions and depths in the gray matter. It was found that the computed magnetic field of radial sources varied significantly with the conductivities of the surrounding tissues where the dipole was located. We also modeled the magnetic field of an epileptic interictal spike in a finite element model of the rabbit head with a single dipole and with extended sources of varying length (1–8 mm). The extended source models developed were based on invasive measurements of an interictal spike within the rabbit brain. The field patterns of the small (1–2 mm) extended sources were similar to a single dipolar source and begin to deviate significantly from a dipolar field for the larger extended sources (6–8 mm).

Pulse switching in nonlinear fiber directional couplers.

Abstract: A comprehensive analysis of the propagation of short pulses in fiber nonlinear directional couplers is presented. In particular, the limitations as well as the merits of the variational approach to describe power- and phase-controlled pulse switching are discussed. Relying on beam propagation calculations a trial function that accounts for variable width, amplitude, phase, and chirp of the pulses is proposed. The corresponding Euler-Lagrangian equations for the pulse parameters are derived and solved. Concerning power-controlled switching an excellent agreement of the switching curve with beam propagation results is found. Moreover, even the evolution of the various pulse parameters is shown to be described reasonably by the analytical model used. Eventually, optimum criteria for efficient phase-controlled switching may be easily derived by using the model presented.

TGFβ and bFGF synthesis and localization in Dupuytren's disease (nodular palmar fibromatosis) relative to cellular activity, myofibroblast phenotype and oncofetal variants of fibronectin

Abstract: Nodular palmar fibromatosis is a self-limited proliferation of fibro-/myofibroblasts associated with growth factor synthesis and abundant fibronectin extracellular matrix deposition. bFGF and TGFβ are potent modulators of fibro-/myofibroblast proliferation and differentiation. Moreover,in vitro investigations evidenced a TGFβ1-dependent regulation of alternative splicing of fibronectin mRNA. To investigate a possible implication of these growth factors in the tissue formation process of palmar fibromatosis, TGFβ1/2 and bFGF synthesis, as well as TGFβ1/3 and bFGF tissue distribution, is demonstrated by RNAin situ hybridization and/or immunohistochemistry in relation to myofibroblast phenotype development (α-smooth muscle actin, desmin immunohistochemistry), expression of different fibronectin isoforms (ED-A+, ED-B+ and oncofetal glycosylated fibronectin immunohistochemistry, fibronectin RNAin situ hybridization) and cellular activity (cyclin RNAin situ hybridization, Ki-67 immunolabelling). The myofibroblast phenotype (α-smooth muscle actin, desmin), the growth factor synthesis (TGFβ1 and 2, bFGF), fibronectin matrix synthesis (RNAin situ hybridization with cDNA) and ED-A+, ED-B+ and oncofetal glycosylated fibronectin immunostaining are exclusively localized in the active proliferative nodules (Ki-67 immunolabelling and cyclin mRNA demonstration). Whereas the growth factor synthesis is restricted to the proliferative areas of the fibromatosis only, TGFβ1, TGFβ3 and bFGF proteins can also be detected immunohistochemically with a lower intensity in the surrounding aponeurotic tissue. The spatial correlation of myofibroblast phenotype, TGFβ and bFGF synthesis and the occurrence of the oncofetal molecular fibronectin variants (ED-B+ and oncofetal glycosylated fibronectin) in the active proliferative fibromatosis nodules suggests a pathogentic role of these growth factors and matrix components in the tumorous tissue formation process. The presence of the bFGF and TGFβ1/3 proteins in fibroblasts neighbouring the proliferative nodules may point to a recruitment of quiescent aponeurotic fibroblasts in the fibromatous tissue formation process.

The biological importance of nickel in the food chain

Abstract: The ultra trace element nickel (Ni) is both essential and toxic for animals and humans. A Ni-poor nutrition of 1% of men after the filling of the Ni depot in the body. Experiments with 4 animal species showed that Ni exposure leads to disturbances in the Mg and above all in the Zn metabolism. Ni excess induces Zn deficiency symptoms which are similar to parakeratosis in pigs. They correspond to the symptoms of nickel allergy in humans. Therefore, the Ni intake of humans, which leads to the gradual filling of the Ni pool in the body and which can then induce nickel dermatitis in Ni-sensitive women and men, is of particular importance. The Ni requirement of adults does not exceed 25 to 35 μg/day. The Ni balance of men and women was positive (+20%) and shows the Ni incorporation even in the case of a Ni consumption which exceeds by far the requirement.

Spectroscopic properties of Nd3+ ions in phoshate glasses

Abstract: The effect of Nd3+ and hydroxyl group concentration, as well as the effect of glass composition on the relaxation processes of excited Nd3+ ions, are studied for various phosphate glasses and a fluoride phosphate glass. The relaxation of the 4F32 level of the Nd3+ ions is dominated by radiative decay, energy transfer to hydroxyl groups and cross-relaxation. Lifetime measurements of this level as a function of hydroxyl group and Nd3+ concentrations lead to a resolution of the individual relaxation processes. Based on this analysis, the relationships between the glass matrix and the concentration quenching and radiative decay rate, respectively, are studied. Finally, the contributions of the individual relaxation processes to the lifetime of the 4F32 level are compared with each other in different glass types.

Investigation of computer-generated diffractive beam shapers for flattening of single-modal CO 2 laser beams

Abstract: A full cycle was realized of the photolithographic development and detailed testing of a diffractive optical element that transforms the diverging Gaussian beams of CO2 lasers into a uniformly filled-in rectangle. The zone feature size of the beam shaper, the diffractive efficiency and accuracy, the focus depth, and the stability with respect to the size and the divergence of incident Gaussian beams are studied by computer modeling. Calculated flattop intensity distributions are presented in the same form of gray-level pictures and three-dimensional plots as the corresponding results measured by an IR camera.

Round robin computer simulation of ion transmission through crystalline layers

Abstract: Round robin computer simulations were performed by 11 groups using 6 different molecular dynamics codes and 6 different binary collision approximation codes. The process simulated is the transmission of 0.2 keV, 0.5 keV, and 1.0 keV B atoms through 9 monolayers of <001⪢Si and the transmission of 1.0 keV Ar atoms through 5 monolayers of <001⪢Cu. In all cases the energy distribution and the angular distribution of the transmitted atoms have been calculated with and without taking into account the interaction between the target atoms. The results of the simulations with the different molecular dynamics codes are in good agreement. The binary collision approximation results are compared with each other and with the molecular dynamics data. Deviations are discussed. It is concluded that the binary collision concept is still applicable for such low energies if simultaneous collisions are taken into account.

Correlation of radiation-field ground-state fluctuations in a dispersive and lossy dielectric

Abstract: The correlation of the quantum-mechanical ground-state fluctuations of the electric-field strength in a dispersive and lossy linear dielectric are studied in terms of the symmetrized autocorrelation function, with special emphasis on the optical frequency domain. Starting from the canonical quantization scheme developed by Huttner and Barnett [Phys. Rev. A 46, 4306 (1992)], the analysis is based on a quantization of the phenomenological Maxwell theory, the effect of the medium being described by a frequency-dependent complex permittivity. In this way, the spectrally resolved ground-state autocorrelation function of the electric-field strength can be expressed in terms of the real and imaginary parts of the refractive index. Both analytical and numerical results are presented and the effects of dispersion and absorption including their dependence on the frequency interval chosen are discussed. A comparison with the vacuum fluctuations in free space is given.

The oxygen coordination of metal ions in phosphate and silicate glasses studied by a combination of x-ray and neutron diffraction

Abstract: A combination of results from x-ray and neutron diffraction is used to obtain structural information about the metal-oxygen coordination shell in oxide glasses. Two ways to extract structural parameters of the Me-O coordination are presented. The first variant is a direct combination of both distance correlation functions which are considered simultanously in a least-squares fit procedure. On the other hand a suitable difference of the two structure factors is introduced, which do not contain any O-O correlation. The corresponding distance correlation function directly shows the Me-O peak. The samples are metaphosphate glasses with Me = Al, Zn, Mg, Ca, Ba and Na and two sodium silicate glasses (76.5 and 67 mol% silicon dioxide). Four oxygens are found in contact to the Mg ion. But two additional, more distant positions are detected. Thus, the sum of all oxygen atoms in the coordination sphere is 6 rather than 4. The Zn cation is located in a real ZnO4-tetrahedron. The number of oxygens in the environment of the Na ion is of about five both in the metaphosphate glass and in the silicate glasses. But a surprising result is a splitting observed for the Na-O distance peak in case of silicate glasses.

Oral brivudin vs. intravenous acyclovir in the treatment of herpes zoster in immunocompromised patients: A randomized double-blind trial

Abstract: The efficacy of oral brivudin vs. intravenous acyclovir was compared in a randomized multicentered study under double-blind conditions using the double-dummy technique. Forty-eight patients with a herpes zoster rash less than 72 hours in duration were entered in the study. Brivudin was given as one 125-mg tablet every 6 hours. Acyclovir was infused over 1 hour at a dose of 10 mg/kg every 8 hours. Treatment was continued for 5 days. There was no significant difference between the treatment groups when analyzed in terms of new lesion formation, increase in the area of rash within the primary dermatome, cutaneous dissemination, and affection of mucous membranes or visceral organs. Both treatment regimes were also equally effective in the time to full crusting of lesions. Oral brivudin and intravenous acyclovir were well tolerated by most patients. There was no need to interrupt the treatment in any case. As effective as intravenous acyclovir in the treatment of herpes zoster, oral brivudin offers the potential for outpatient treatment of herpes zoster in immunocompromised patients.