Effects of Micronization on Digestive Absorption of Diosmin

Objective:

To investigate the effect of diosmin particle size on the rate and extent of absorption and excretion of total radioactivity, following oral administration of micronized and non-micronized [14C]-diosmin to New Zealand White rabbits.

Design:

This study was conducted in a 2 x 12 cross-over design at a uniform target dose level of 10 mg/kg, and was conducted according to Good Laboratory Practice. The micronized formulation was prepared using a Microdismembrator II, and all prepared doses were suspended in 0.5% w/v aqueous methylcellulose at a target concentration of 5 mg/ml. Particle size analysis indicated that in the micronized formulation, 90% of particles were ≤2 <m, and in the non-micronized formulation, more than 75% of particles were ≥3 <m.

Results:

Analysis of percentage dose excreted via urine post-dose indicated a higher urinary output in the animals that received micronized diosmin (mean of 72% dose in both 0–48 h and 0–168 h) compared with means of 16% dose and 17% dose, respectively, in animals that received the non-micronized formulation. Statistical analysis showed these differences to be highly significant ( p < 0.0001), with no evidence of sequence or phase effects.

Conclusion:

Reduction of particle size of [14C]-diosmin when administered orally as a suspension to rabbits resulted in a marked increase in the proportion of the dose excreted in urine. This increase was considered to reflect an increased absorption of radiolabelled components from the micronized dose.

Antibody-Mediated Protection against Genital Herpes Simplex Virus type 2 Disease in Mice by Fc gamma Receptor -Dependent and -Independent Mechanisms (41.8)

The requirement for Ab -Fcγ receptor (FcγR) interactions or for virus neutralization in protection against genital HSV-2 challenge was examined. Serum IgG Ab isolated from HSV-immune mice protected normal mice against HSV-2 disease when administered prior to challenge. However, protection was significantly diminished in mice lacking the γ chain subunit utilized in FcγRI, FcγRIII, FcγRIV, and FcεRI and in normal mice depleted of FcγR+, Gr-1+ immune cells suggesting protection was largely mediated by an FcγR-dependent mechanism. To test if FcγR-independent antibody-mediated mechanisms might manifest protection differently, a highly neutralizing, HSV glycoprotein D -specific monoclonal antibody (mAb) was utilized. Administration of IgG1, IgG2a, or IgG2b switch variants of the mAb did not prevent infection of the genital tract but resulted in lower virus loads in the vaginal epithelium and provided significant protection against disease and acute infection of the sensory ganglia independently of host FcγR expression. Together, these data demonstrate two distinct antibody effector mechanisms capable of providing substantial protection against genital HSV-2 disease. The presence of either FcγR -dependent Ab or strongly neutralizing Ab did not completely prevent HSV-2 infection but limited initial infection of genital and neuronal tissues and diminished HSV-2 disease. NIH Grants AI42815 and AI054444.

Synthesis, characterization, and electrochemistry of cis-oxothio- and cis-bis(thio)tungsten(VI) complexes of hydrotris(3,5-dimethylpyrazol-1-yl)borate

The complexes TpWO2X react with sulfiding agents such as B2S3 or P4S10 to give the oxothio- and bis(thio)tungsten(VI) complexes TpWOSX (X = Cl(-)) and TpWS2X [X = Cl(-), S2PPh2(-); Tp = hydrotris(3,5-dimethylpyrazol-1-yl)borate]. The reaction of TpWS2Cl with (i) PPh3 in pyridine and (ii) dimethyl sulfoxide affords TpWOSCl in good overall yield. The chloro complexes undergo metathesis with alkali metal salts to yield species of the type TpWOSX and TpWS2X [X = OPh(-), SPh(-), SePh(-), (-)-mentholate]. The diamagnetic complexes exhibit NMR spectra indicative of C(1) (TpWOSX) or C(s) (TpWS2X) symmetry and IR spectra consistent with terminal oxo and thio ligation (nu(W=O), 940-925 cm(-1); nu(W=S) or nu(WS2), 495-475 cm(-1)). Crystals of (R,S)-TpWOS[(-)-mentholate] are monoclinic, space group P2(1), with a = 11.983(2) A, b = 18.100(3) A, c = 13.859(3) A, beta = 91.60(2) degrees, V = 3004.6(8) A(3), and Z = 4. Crystals of TpWS2(OPh)-CH2Cl2 are orthorhombic, space group Pbca, with a = 16.961(4) A, b = 33.098(7) A, c = 9.555(2) A, V = 5364(2) A(3), and Z = 8. The mononuclear, distorted-octahedral tungsten centers are coordinated by a tridentate Tp ligand, an alkoxy or aryloxy ligand, and two terminal chalcogenide ligands. The average W=O and W=S distances are 1.726(7) and 2.125(2) A, respectively, and the O=W=S and S=W=S angles 102.9(3) and 102.9(1) degrees, respectively. The tungsten and sulfur X-ray absorption spectra of TpWOSCl and TpWS2Cl are consistent with the presence of terminal pi-bonded thio ligands in both complexes. The thio complexes generally undergo a reversible one-electron reduction at potentials significantly more positive than their oxo analogues. The chemical, spectroscopic, and electrochemical properties of the complexes are heavily influenced by the presence of W=S pi frontier orbitals.

Hydrogen peroxide- and peroxynitrite-induced mitochondrial DNA damage and dysfunction in vascular endothelial and smooth muscle cells

The mechanisms by which reactive species (RS) participate in the development of atherosclerosis remain incompletely understood. The present study was designed to test the hypothesis that RS produced in the vascular environment cause mitochondrial damage and dysfunction in vitro and, thus, may contribute to the initiating events of atherogenesis. DNA damage was assessed in vascular cells exposed to superoxide, hydrogen peroxide, nitric oxide, and peroxynitrite. In both vascular endothelial and smooth muscle cells, the mitochondrial DNA (mtDNA) was preferentially damaged relative to the transcriptionally inactive nuclear beta-globin gene. Similarly, a dose-dependent decrease in mtDNA-encoded mRNA transcripts was associated with RS treatment. Mitochondrial protein synthesis was also inhibited in a dose-dependent manner by ONOO(-), resulting in decreased cellular ATP levels and mitochondrial redox function. Overall, endothelial cells were more sensitive to RS-mediated damage than were smooth muscle cells. Together, these data link RS-mediated mtDNA damage, altered gene expression, and mitochondrial dysfunction in cell culture and reveal how RS may mediate vascular cell dysfunction in the setting of atherogenesis.

Pharmacokinetics of the anticoagulant 14C-DX-9065a in the healthy male volunteer after a single intravenous dose

1. The plasma pharmacokinetics, excretion and metabolism of DX-9065a were studied in the healthy male Caucasian volunteer after a single intravenous dose of 10 mg 14C-labelled DX-9065a. 2. At the end of a 1 h infusion, the mean plasma concentration of total radioactivity was 380 ng ml(-1) (equivalent to unchanged DX-9065). Thereafter, it decreased in a bi-exponential manner and was below the detection limit by 48 h after dosing. The half-life for the distribution phase was 6.93 h. 3. The total radioactivity recovered in urine and faeces by 336 h post-dose was 83.8% of the administered dose, with excretion ongoing at the end of the 14-day collection. The major route of excretion was via urine, accounting for a mean of 77.6% of the administered radioactivity. The urinary excretion profile was biphasic, consisting of rapid (0-24 h) and slow (24-336 h) phases. A large renal clearance suggested that renal tubular secretion might contribute to the excretion of DX-9065 via urine. 4. No metabolite peaks in the radio-HPLC chromatograms of urine samples were detected, indicating that biotransformation of DX-9065 does not play a significant role in the elimination of DX-9065 in man.

Effect of age on the expression of Pex (Phex) in the mouse

Pex is a newly discovered gene (also called Phex) whose mutation is the cause of X-linked hypophosphatemia. Other members of this gene family encode endopeptidases that activate or inactivate endocrine and paracrine factors. Though embryonic bone expresses mRNA for the Pex gene at relatively high levels, we have found Pex expression to be widespread in adult organs and to be poorly expressed in adult bone. This led to the hypothesis that Pex mRNA expression changes with age. To test this, genetically normal mice of the B6C3H hybrid strain were studied at 0 (newborn), 2, 3, 10, and 72 weeks of age. Organs known to express Pex were collected, and RNA was extracted from them. Following reverse transcription, cDNA was amplified by the polymerase chain reaction with primers for Pex and G3PDH, a housekeeping gene. The amplimers were separated by electrophoresis, blotted onto nylon membranes, and hybridized with radioactively labeled internal oligonucleotide probes. The radioactivity was quantified, and the data were analyzed as the Pex/G3PDH ratio. The brain samples had high levels of Pex mRNA expression that rose slightly with age. Calvaria, kidney, and lung samples had the highest Pex mRNA expression at birth. In these organs Pex mRNA expression fell with age to undetectable or barely detectable levels. Thymus, heart, and skeletal muscle samples had low Pex mRNA expression at birth that did not change with age. Some organs showed a decline in G3PDH levels with age, but Pex expression decreased more, leading to a reduced Pex/G3PDH ratio. The widespread expression of mRNA for Pex suggests a role beyond that of phosphate homeostasis. The high level of expression in newborn animals suggests a role in growth and development. This seems to occur in addition to its role for the endocrine regulation of phosphate homeostasis by as yet unknown humoral agents that must occur throughout life. In summary, Pex mRNA expression is high in brain and bone at birth. Expression remains high in brain with age but falls with age in bone, kidney, and lung.

Generation and biomimetic chemistry of tungsten-dithiolene complexes containing the hydrotris(3,5-dimethylpyrazol-1-yl)borate ligand

Reactions of bis(thio)-W(VI) complexes, LWS2X (L = hydrotris (3,5-dimethylpyrazol-1-yl)borate, X = monoanion), with alkynes produce dithiolene complexes, LWX(dithiolene). The synthesis and characterization of orange LW(OPh){S2C2(CO2Me)2} (1) and burgundyred LW(SePh) {S2C2(Ph)(2-quinoxalinyl)} (2) and the X-ray crystal structure of 1.0.5CH2Cl2, are described in detail. Crystals of 1.0.5CH2Cl2 are orthorhombic, space group Pbcn, with a = 29.826(6), b = 13.291(4), c = 16.078(4) A, V = 6373(5) A3, and Z = 8. The six-coordinate, distorted-octahedral complex features a tridentate L ligand, a monodentate phenoxide ligand, and a bidentate dithiolene ligand. The short W-S bonds (2.267(4) and 2.279(4) A) and the parameters associated with the phenoxide ligand (W-O = 1.850(8) A, W-O-C = 146(1) degree), point to a considerable degree of W-ligand multiple bonding in the [W(OPh)(dithiolene)]+ unit. For 2, W-Se and average W-S distances of 2.49(2) A and 2.30(2) A, respectively, have been obtained from EXAFS studies. The formation of yellow 3,3'-dithiobis[2-(phenyl)thieno[2,3-b]quinoxaline] (3) upon oxidation of 2 supports the likely generation of urothione upon oxidative degradation of molybdopterin-containing tungsten enzymes from hyperthermophilic organisms.

Relationship between cytotoxicity and conversion of thiosangivamycin analogs to toyocamycin analogs in cell culture medium

Non-nucleoside analogs of the pyrrolopyrimidine nucleosides toyocamycin, sangivamycin and thiosangivamycin have been synthesized and their cytotoxicity in mammalian cells determined. While studying the effects of 5-thioamide-substituted analogs on cell growth, we observed an interesting phenomenon in which cells recovered spontaneously from growth inhibition during extended incubations. HPLC studies demonstrated that the 5-thioamide moiety of several structurally dissimilar 7-substituted 4-aminopyrrolo[2,3-d]pyrimidines, including thiosangivamycin, is unstable in cell culture medium and is converted to the corresponding 5-nitrile with a half-life of approximately 48 h. In contrast, different substituents at the 4-position of the heterocycle significantly affected the stability of the 5-thioamide moiety. Conversion of the thioamide to the nitrile was caused by components in the cell culture medium, not components of serum. The above observations demonstrate that caution should be exercised in interpreting biological data obtained in vitro for 5-thioamide pyrrolo[2,3-d]pyrimidines.

Synthesis, Characterization and X-Ray Crystal Structure of {H2B(Me2C3N2H)2}MoIVO(S2PPrI2)

Reaction of MoO (S2PPri2)2 and K{H2B(Me2C3N2H)2} in refluxing toluene produces green, diamagnetic, air-stable {H2B(Me2C3N2H)2}MoIVO(S2Ppri2)(1), which has been characterized by analytical, mass spectrometric, infrared and n.m.r. spectroscopic, and X-ray crystallographic techniques. Crystals of (1) are triclinic and belong to space group Pī , with a 10.289(1), b 13.601(2), c 8.737(1) Ǻ, α 94.31(1), β 107.71(1), γ 79.56(1)°, V 1145.2 Ǻ3 and Z 2. The structure was solved by Patterson and Fourier methods and refined by using 3631 reflections to a final R value of 0.024 ( Rw 0.041). The five-coordinate square pyramidal complex is composed of apical terminal oxo [Mo-O(1) 1.658(2)Ǻ] and bidentate H2B(Me2C3N2H)2- and S2PPri2- ligands coordinated to molybdenum. Ferrocenium oxidation of (1) produces the mononuclear molybdenum(V) complex [{H2B(Me2C3N2H)2}MoVO(S2Ppri2)]+ ( e.p.r .: g 1.964, a(95,97Mo) 41.7×10-4cm-1, a(31P) 30.1×10-4 cm-1).

Tris(N,N-dialkyldithiocarbamato-S,S')thiotungsten(VI) Complexes and the X-Ray Crystal Structure of [WS(S2CNEt2)3]BF4

The orange, diamagnetic compounds [WS(S2CNR2)3]X(R = Me, X- = BF4-, BPh4-;R = Et, X- =BF4-) were prepared by reacting WSCl4 and Me3SiS2CNR2 in dichloromethane, followed by metathesis with NaX in methanol. The compounds were characterized by elemental analysis, infrared and variable-temperature 1H n.m.r. spectroscopy and X-ray crystallography. Crystals of [WS(S2CNEt2)3] BF4 were monoclinic, space group P21/a with a 12.293(1), b 17.229(5), c 14.257(2) Ǻ,β 113.69(1)°, V 2765(2) Ǻ3 and Dc = 1.796 g cm-3 for Z = 4. The structure was solved by the Patterson method and refined by a full-matrix least-squares procedure, 3961data being used, to a conventional R value of 0.039 ( Rw = 0.040). The seven-coordinate cation possesses a pentagonal-bipyramidal geometry; the terminal thio ligand [W=S 2.127(2)Ǻ] occupies an axial position, a unique dithiocarbamate ligand spans the other axial position and an equatorial position while the two other dithiocarbamate ligands occupy the four remaining equatorial sites.

Structural Aspects of V2( µ;-S2)2(S2CNR2)4 Complexes: the X-Ray Crystal Structure of V2( µ;-S2)2(S2CNEt2)4.2CHBr3

Brown V2(p-S2)2(S2CNEt2)4 is produced upon reaction of [vs4]3- with (Et2NCS2)2, in a synthesis similar to that described for V2( �-S2)2(S2CNBui2)4 ( Halbert , T. R., Hutchings, L. L., Rhodes, R., and Stiefel , E. I., J. Am. Chem. Soc., 1986, 108, 6437). Crystals of V2( �;-S2)2(S2CNEt2)4.2CHBr3 are orthorhombic and belong to space group Pbca , with a 10.909(2), b 20.492(2), c 20.471(2) � , V 4576.2 �3, and Z 4 dimers . The structure was solved by Patterson and Fourier methods and refined by using 1189 reflections to final R 0.061 ( Rw 0.059). The vanadium(IV) atoms in the dimeric complex are bridged by two �-k2S,S′: k2S,S′-S22- ligands [S(1)-S(2) 2.00(1) �] and a metal-metal single bond [V-V 2.900(6) �]. Each vanadium atom is further coordinated by two bidentate dithiocarbamate ligands whose arrangement defines a meso isomer with Λ and Δ configurations at the vanadium centres. This Λ Δ diastereomer differs from the Λ Λ -ΔΔ racemate structurally characterized in the case of V2(�-S2)2(S2CNBui2)4 but is the same as that found for the molybdenum(v) dication in [Mo2( �S2)2(S2CNEt2)4] (BF4)2.2CHBr3 ( Kocaba, T., Young, C. G., and Tiekink , E. R. T., Inorg. Chim. Acta, 1990, 174, 143).

MoO(S2)(S2CNR2)2 Complexes (R = Me, Et, Pr, Bu): Improved Syntheses and Thermogravimetric and Nuclear Magnetic Resonance Studies

The reactions of MoO (S2CNR2)2 [R=Me, Et, Pr, Bu; formed in situ from the reactions of cis-MoO2(S2CNR2)2 and PR′3 (R′= Ph, Bu)] and propylene sulfide in 1,2-dichloroethane (for R = Me) or dichloromethane (others) constitute convenient, high-yield syntheses for the blue, seven-coordinate complexes MoO (S2)(S2CNR2)2 The complexes have been characterized by elemental analysis, infrared, electronic and 1H and 13C n.m.r. spectroscopy, and mass spectrometry. Thermogravimetric analyses indicate decomposition of the complexes to Mo2O2(μ-S)2(S2CNR2)2 at temperatures greater than 160°C.

Nitridomolybdenum Complexes of Tris(3,5-dimethylpyrazol-1-yl)Hydroborate and the X-Ray Crystal-Structure of {HB(3,5-Me2C3N2H)3)MoN(N3)2

The reaction of (NEt4)2[MoNCl5] and K{HB(Me2pz)3}[HB(Me2pz)3- = tris (3,5- dimethylpyrazol-1-yl) hydroborate anion] produces both purple, diamagnetic {HB(Me2pz)3}MoNCl2 (1) and yellow, paramagnetic Net4 [{HB(Me2pz)3}MoNCl2] (2) (e.s.r.: {g} 1.961, {a}(95Mo) 57×10-4 cm-1), which have been separately isolated under different conditions. In contrast, the reaction of [ MoN (N3)4]- with Na{HB(Me2pz)3} results in the exclusive formation of red {HB(Me2pz)3} MoN (N3)2 (3). Crystals of (3) are monoclinic and belong to space group P21/n with a 16.440(2), b 8.787(2), c 16.754(2) Ǻ,β 112.47(1)°, V 2236.4 Ǻ3, and Z 4. The structure was solved by Patterson and Fourier methods, followed by least-squares refinement, using 3208 reflections, to a conventional R value of 0.032 ( Rw 0.047). In the distorted octahedral complex the molybdenum(VI) atom is coordinated by a facial HB(Me2pz)3- ligand , a terminal nitrido ligand with a Mo-N bond distance of 1.646(4)Ǻ, and two azide ligands. All complexes have been characterized by elemental analysis, infrared, 1H n.m.r. or e.s.r. spectroscopy, and mass spectrometry. Improved syntheses for the starting materials (NEt4)2 [MoNCl5] and (NEt4)2 [MoNCl4] are also reported.

Synthesis and X-Ray Structure of syn-Di-μ-thio-bis[(N,N-diethyldithiocarbamato-S,S')oxotungsten(V)]

The reaction of WSCl4 and Me3SiS2CNEt2 in tetrahydrofuran produces a green solid which yields WS(S2)(S2CNEt2)2, WO(S2)(S2CNEt2)2 and syn-W2O2( �-S)2(S2CNEt2)2 upon exposure to oxygen. Crystals of syn-W2O2( �-S)2(S2CNEt2)2 are monoclinic and belong to space group C2/c with a 33.880(4), b 7.012(1), c 18.072(1) � ,β 105.94(1)� and Z 8. Refinement on 2651 data measured with Cu K α: radiation converged at R 0.070. The complex possesses a syn-[W2O2(�-S)2]2+ core with a W-W bond [2.808(1) � ] and two terminal W-O bonds [1.66(2) and 1.68(2) � ]. The W-S(bridging) bond distances are in the range 2.319(5)-2.3346) � Each of the square-pyramidal tungsten atoms is further coordinated to a bidentate dithiocarbamate ligand with W-S bond distances ranging from 2.447(6) to 2.459(5) � .

An Investigation of Adduct Complexes of M(S2CNEt2)2(Co)2 (M=Mo,W) by 95Mo and 183W N.M.R-Spectroscopy

The seven-coordinate adducts M(S2CNEt2)2(CO)2L and [M(S2CNEt2)2(CO)2]2-μ-L (M = Mo, W;L below), derived from the 16-electron complexes M(S2CNEt2)2(CO)2, have been investigated by 95Mo and 183W n.m.r. spectroscopy. The molybdenum and tungsten adducts exhibit resonances in the regions from 310 to -430 and from -465.5 to -1500 ppm , respectively. All the resonances are shielded relative to those of the M(S2CNEt2)2(CO)2 precursors. The dependence of the nuclear shielding on L is as follows. For M = Mo: NH2NHSO2C6H4Me < Cl - < OPPh3 < μ- pyrazine < pyridine < NH2NHCOPh < NH2NMe2 < μ-NH2NHMe < μ-NH2NH2 < μ-NH2CH2CH2NH2 < NH3 < N3- < F- < AsPh3 < PPh3 < SbPh3 < PPh2Et < PPh2Me < PMe3 < P( OPh )3 < P( OEt )3 < P( OMe )3 < CO. For M = W: NH2NHCOPh < AsPh3 < Ph2PCH2PPh2 < PPh3 < PPh2Et < Ph2PCH2CH2PPh2 < PPh2Me < PMe3 < P( OPh )3 < P( OEt )3 < P( OMe )3 < CO. The OPPh3, halide and nitrogen-donor ligand adducts participate in a dynamic equilibrium with Mo(S2CNEt2)2(CO)2 on the n.m.r . time scale. The remaining adducts do not exhibit such behaviour. The chemical shifts of both the molybdenum and tungsten adducts are correlated with the π- acceptor ability of the ligand , L, and the stereochemistry of the adducts. A linear relationship between the chemical shifts of analogous molybdenum and tungsten complexes is observed; the equation of the line is δ(183W) = 1.46δ(95Mo)-857.5.

Tungsten carbonyl complexes with dithiocarbamate ligands

The orange seven-coordinate complexes W(S2CNR2)2(CO)3 (R = Me, Et) have been prepared by the reaction of WBr2(CO)4 and NaS2CNR2.�The tricarbonyl complexes were converted into the coordinatively unsaturated complexes W(S2CNR2)2(CO)2 by reflux in methanol. The compounds provide a new route into carbonyl dithiocarbamato complexes of tungsten and their reactions with various N- and P-donor ligands have given the new complexes W(S2CNR2)2(CO)2L (R = Me,Et; L = NH2NHMe, NH2NMe2, NH3, NH2NHCOPh, C5H5N, NH2NHSO2C6H4Me, PPh3) and bridged species [W(S2CNR2)2(CO)2]2-.μ-B (B = N2H4, NH2CH2CH2NH2). The synthesis and the 1H n.m.r, and infrared spectra of the compounds are presented and discussed. The electronic spectra of W(S2CNR2)2(CO)3 and W(S2CNR2)2(CO)2 are also reported.

A sun-pumped cw one-watt laser

1 W of w laser output has been obtained at room temperature from a sun-pumped, neodymium-doped YAG crystal. The water-cooled laser rod was pumped with a modified Cassegrain sun-tracking telescope consisting of a 61-cm diam paraboloidal primary mirror collector, a water-cooled hyperbolic-cylindric secondary mirror and a hemicircular cylindric tertiary mirror. The cylindrical image volume was coincident with 24 mm of the 3-mm by 30-mm YAG rod. The spike-free output was obtained for hours at a time with a late October sun at a 42 degrees North latitude. Using the same primary mirror and near-unity numerical aperture refractors, approximately 1.25 W were obtained in 7 msec pulses from an uncooled, sun-pumped, neodymium-doped, glass rod. Further refinements in the telescope and the laser crystal, and a space environment, should allow 1 W of laser output to be generated by using a 30-cm diam collector.