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We report the detection and characterization of the Ni(III) intermediates generated by reaction of (1,4,8,11-tetraazacyclotetradecane)nickel(II) perchlorate with KHSO5. Four Ni(III) intermediates can be trapped or detected through variation in Cl- or KHSO5 concentrations. Upon oxidation of [Ni(cyclam)]2+ by 2.5 equiv of KHSO5, deprotonation of the cyclam ligand generates two red Ni(III) species with lambda max = 530 nm and g perpendicular = 2.20 and g parallel = 2.02 or g perpendicular = 2.16 and g parallel = 2.01 for the axial 4-coordinate or 6-coordinate dichloride species, respectively. These forms decay to Ni(II) products via complex ligand oxidation mechanisms. The Ni(III) dichloride species can be reprotonated and subsequently binds to DNA via an outer-sphere interaction as evidenced by the inverted sign of the CD signal near 400 nm. Cumulatively, the results indicate that the Ni(III) center is coordinately saturated under excess chloride conditions but is still able to interact with DNA substrates. This suggests alternative mechanistic pathways for DNA modification by reaction of [Ni(cyclam)]2+ with KHSO5 and possibly other Ni(II) complexes as well.

Peritrichs attached to submerged macrophytes, filamentous chlorophytes and debries have been found in San Miguel del Monte pond (Buenos Aires province, Argentina) during the period March 1998- March 1999. Specimens were identified, illustrated and measured alive. Fourteen species of Subclass Peritrichia new for the country are described, illustrated and commented: Epistylis hentscheli, E. tubificis, E. vestita, Opercularia elongata, Cothurnia annulata, Cothurniopsis valvata, Pyxicola limbata, Thuricola innixa, Th. kellicotiana, Vaginicola attenuata, Vorticella picta, V. pulchella, V. rotunda, and Zoothamnium ramosissimum., Peritricos adheridos a macrófitas acuáticas, clorofitas filamentosas y partículas fueron hallados en la laguna de San Miguel del Monte (provincia de Buenos Aires, Argentina) durante el período marzo 1998 - marzo 1999. Los especímenes fueron identificados, dibujados y medidos in vivo. Se brinda una breve descripción, ilustración y algunos comentarios de catorce especies de la subclase Peritrichia, nuevas para el país: Epistylis hentscheli, E. tubificis, E. vestita, Opercularia elongata, Cothurnia annulata, Cothurniopsis valvata, Pyxicola limbata, Thuricola innixa, Th. kellicotiana, Vaginicola attenuata, Vorticella picta, V. pulchella, V. rotunda y Zoothamnium ramosissimum., Contribución científica Nº 688 del Instituto de Limnología (ILPLA)., Instituto de Limnología "Dr. Raúl A. Ringuelet"

The authors present 10 cases of malignant lymphomas of the head and neck hospitalized in ENT Department of Regional Hospital in Belchatów. The two cases of tonsil lymphomas were described in detail calling attention to diagnostic difficulties. The false result of aspiration biopsy caused prolongation of diagnostic procedure.

Secondary hyperparathyroidism is still one of the main problems affecting the dialysis population. The use of aluminium hydroxide as a phosphate binder is limited by significant long-term toxicity. Therefore, actually, most patients on haemodialysis receive treatment with calcium containing phosphate binders to avoid hyperphosphataemia.

Thermal Bergman cyclization of Pt(II) dialkynylporphyrins reveals a marked reduction in the cyclization temperature relative to the free base and Zn(II) derivatives. In contrast, photogenerated (3)ππ* population produces no detectable Bergman photocyclization, suggesting that the photoreactivities of the related free base and Zn(II) derivatives occurs via the (1)ππ* state.

The cross-coupling reaction of 2,3-dibromo-5,10,15,20-tetraphenylporphyrin with corresponding organostannanes in the presence of a Pd0 catalyst in THF at reflux temperature yields free base 2,3-dialkynylporphyrins 1a,c-e. The subsequent deprotection of trimethylsilyl group of 1a with TBAF in THF under aqueous conditions produces the 2,3-diethynyl-5,10,15,20-tetraphenylporphyrins 1b in 87% yield. Compounds 1a-d undergo zinc insertion upon treatment with Zn(OAc)2.2H2O in CHCl3/MeOH to give zinc(II) 2,3-dialkynyl-5,10,15,20-tetraphenylporphyrins (2a-d) in 70-92% yields. Thermal Bergman cyclization of 1a-e and 2a-d was studied in chlorobenzene and approximately 35-fold 1,4-cyclohexadiene at 120-210 degrees C. Compounds 1b and 2b with R = H react at lower temperature (120 degrees C) and produce cyclized products 3b and 4b in higher yields (65-70%) than their propyl, isopropyl, and phenyl analogues, with R = Ph being the most stable. Continuing in this trend, the -TMS derivatives 1a and 2a exhibit no reactivity even after heating at 190 degrees C in chlorobenzene/CHD for 24 h. Photolysis (at lambda/= 395 nm) of 1b and 2b at 10 degrees C leads the formation of isolable picenoporphyrin products in 15 and 35% yields, respectively, in 72 h, whereas these compounds are stable in solution under same reaction conditions at 25 degrees C in the dark. Unlike thermolysis at 125 degrees C, which did not yield Bergman cyclized product for R = Ph, photolysis generated very small amounts of picenoporphyrin products (3c: 5%; 4c: 8% based on 1H NMR) as well as a mixture of reduced porphyrin products that were not separable. Thus, trends in the barrier to Bergman cyclization in the excited state exhibit the same trend as those observed in the ground state as a function of R-group. Finally, photolysis of 2b at 10 degrees C with lambda/= 515 or 590 nm in benzene/iPrOH (4:1, 72 h) produces 4b in 15 and 6% isolated yields, indicating that conjugation of the enediyne unit into the porphyrin electronic transitions leads to sufficient distortion to generate photoproduct even with long wavelength excitation.

We have synthesized the nickel(II) 2,3-bis(haloethynyl)-5,10,15,20-tetraphenylporphyrins with -Br (2a) or -I (2b) at the alkyne termini position from the corresponding 2,3-diethynyl analogue (1). The cross coupling of nickel(II) 2,3-dibromo-5,10,15,20-tetraphenylporphyrin with trimethyl(trimethylstannanylethynyl)silane in the presence of a Pd0 catalyst and subsequent deprotection with base under aqueous conditions yields the nickel(II) 2,3-diethynyl-5,10,15,20-tetraphenylporphyrin (1). Subsequent reaction of 1 with N-bromo- or N-iodosuccinimide in dry acetone in the presence of AgNO3 yields 2,3-bis(haloethynyl)-5,10,15,20-tetraphenylporphyrins in 70% (2a) and 68% (2b) yields. The X-ray crystal structures of 2a,b show that the porphyrin backbone deviates significantly from planarity due to a Ni(II)-induced mixture of the classic ruffle and saddle distortions. Thermolysis of 2a at 190 degrees C for 6 h in chlorobenzene and 30-fold 1,4-cyclohexadiene (CHD) generates the Bergman cyclized nickel(II) dibromopicenoporphyrin product (3) in 65% yield, which derives from diradical addition across the adjacent meso-phenyl substituents. Similarly, nickel(II) 2,3-bis(iodoethynyl)-5,10,15,20-tetraphenylporphyrin, 2b, cyclizes at 190 degrees C in chlorobenzene/CHD via high-temperature substitution of iodine by hydrogen (from CHD) or chlorine (from solvent) to afford a mixture of 4 (15%) and 5 (45%). Remarkably, ambient temperature incubation of 2a in MeOH/CHCl3 (1:3, 22 h) or chlorobenzene/CHD (3:1, 24 h) leads to generation of 3 in 15% and 22% isolated yields, respectively. Addition of 1.2 equiv of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in CHCl3/MeOH dramatically accelerates the rate of reaction, producing 3 in 30% yield within 0.5 h. The origin of the ambient temperature activation of 2a derives from the ability of electron-withdrawing functionalities at the alkyne termini to decrease the activation barrier to the Bergman product.

The Bergman cyclization of simple diethynylporphyrinic-enediynes exhibits a double activation barrier to the formation of Bergman cyclized product. Addition of H-atom acceptor accelerates the formation of the picenoporphyrin, indicating that the second barrier is rate limiting.

Electron paramagnetic resonance, electronic absorption, and resonance Raman spectroscopy reveal that in the oxalate-bridged compounds, [[(tBuCO2)3M2]2(μ-O2CCO2)]+[PF6]−, the unpaired electron is delocalized over four metal centers (M = Mo or W) as a result of M2 δ to bridge π conjugation, but in the related cationic perfluoroterephthalate-bridged species, the tungsten complex is delocalized and the molybdenum analogue valence trapped.

Sow and piglet variables related to probability of stillbirth and to viability score were analyzed in litters from 98 multiparous Yorkshire sows. Immediately after the birth of each piglet, viability was scored using Randall's method. Sow variables related to the probability of stillbirth were average birth weight of the litter (p = 0.0001), sow age (p = 0.001), sow condition score (p = 0.003), length of gestation (p = 0.005), and number of piglets in the litter (p = 0.01). Sow variables related to average viability score were average birth weight of the litter (p = 0.001), standard deviation in birth weight in the litter (p = 0.02), sow age (p = 0.03), sow condition score (p = 0.03), and length of gestation (p = 0.03). Piglet variables related to probability of stillbirth were piglet hemoglobin (p = 0.0001), position in the birth order (p = 0.0001), broken umbilical cord (p = 0.0004), and preceding birth interval (p = 0.0004). Piglet variables related to viability score were piglet hemoglobin (p = 0.0001), position in the birth order (p = 0.0001), broken umbilical cord (p = 0.0001), preceding birth interval (p = 0.0001), and birth weight (p = 0.004). Preceding birth interval was related to whether the piglet was live or stillborn (p = 0.0001), to position in the birth order (p = 0.003), and to the sex of the piglet (p = 0.03).The results demonstrated that sow and piglet variables were highly correlated to probability of stillbirth and to viability score. In addition it was also found that the probability of stillbirth was not associated with the duration of farrowing but with the number of piglets in the litter and piglet hemoglobin level. This study also found that lower weight piglets tend to have poor viability, but are not more prone to stillbirth as commonly suggested. These low viability piglets may survive if the necessary care is given during the farrowing process.

Isostructural d10 metalloenediynes of Cu(I), Pd(0) and Ag(I) exhibit metal-dependent variations in their thermal Bergman cyclization temperatures which correlate with differences in their alkyne termini separations.

Visible wavelength ligand-to-metal (LMCT) activated N2 release from tris(3-hydroxy-1,2,3-benzotriazine-4(3H)-one]iron(III) produces localized ligand radical intermediates capable of cleaving DNA and represents a new chemical approach to photonuclease design for biological applications.

The steric influences of the functional groups at the termini of acyclic enediynes can dramatically affect the Bergman cyclization temperatures of the resulting compounds.

Bis(9-diazo-4,5-diazafluorene)copper(II) nitrate is an effective DNA photocleaving agent under anaerobic conditions using visible light and represents a potential model for the action of Kinamycin antitumor antibiotics.

The use of di-2-pyridyl ketone oxime (Hpko)/X− “blends” (X− = OH−, Cl−, ClO4−) in copper chemistry has yielded neutral binuclear and cationic trinuclear, pentanuclear or hexanuclear complexes. Various synthetic procedures have led to the synthesis of compounds [Cu5(pko)7]·[ClO4]3·2CH3OH·2H2O (1), [Cu3(pko)3(OH)(Cl)]2[Ph4B]2·4DMF·2H2O (2), [Cu2(pko)4] (3), {[Cu6(pko)6ClO4(CH3CN)6][Cu6(pko)6(ClO4)3(CH3CN)4]}·8ClO4·14CH3CN·H2O (4). The structures of the complexes have been determined by single-crystal X-ray crystallography.

10619 Background: The concept of early breast cancer detection has evolved to mean the discovery of a premalignant lesion or an early stage invasive lesion prior to metastasis. Therefore, methods must be developed to identify the actual primogenitors of cancer, those lesions which with certainty will progress to cancer. Currently, two technologies are employed for routine imaging of the breast: mammography and ultrasonography. Neither of these techniques can unequivocally distinguish between benign and malignant tissue limiting them to detection but not diagnosis. We hypothesize that differences in Raman spectra will enable the accurate discrimination of breast lesions one from one another and from normal breast epithelia. Therefore, preliminary studies were performed to investigate the potential of Raman spectroscopy. Methods: Cyropreserved breast tissue was selected, sectioned (10 μM) and stained with Hematoxylin and Eosin to verify the histologic diagnosis and to guide the acquisition of Raman spectra from a consecutive section (30 μM). This “analysis” section is mounted on Permanox (polyolefin; Nunc, Rochester, NY) over an area of the slide perforated with small holes (dia. 1mm) to provide the laser with direct access to the tissue without background Raman scattering from the polyolefin. Using a Raman microscope spectra were obtained from multiple areas of five breast tumors to address the reproducibility of spectral similarities across different tumors, to identify spectral differences between malignant and benign tissue, to identify spectral differences between invasive and ductal carcinoma in situ (DCIS) and to optimize the integration time. Results: In general, the spectral profiles for each tissue type are conserved with distinct differences in the predominance and peak widths of specific vibrations. Even in the absence of complex algorithms, malignant vs. benign tissue identification is possible. An analysis of the ability to reliably distinguish between invasive ductal carcinoma and DCIS will have to await additional spectra. A sound vibrational fingerprint of the tissue, consistent with that of the high signal/noise scan at 10 minutes, can be obtained within 30 seconds. Conclusions: Raman spectroscopy with short collection times shows promise and warrants further investigation. No significant financial relationships to disclose.

The surface of a beta solution treated and overaged Ti–6Al–4V alloy specimen deformed by laser shock processing was studied using electron backscatter diffraction, scanning electron microscopy, and atomic force microscopy. Slip steps were observed within grains oriented with their c axis nearly parallel to the specimen surface normal. Based on the slip step traces and orientation information, the slip planes were determined to be {112¯2} for grains with their c axis within 15° of the specimen surface normal and {112¯1} for grains with their c axis between 15° and 40° away from the specimen surface normal. Although both these planes are known to belong to twinning systems, {112¯2}⟨112¯3¯⟩ and {112¯1}⟨112¯6¯⟩, respectively, the latter has not been observed to operate as a slip system. Examination of the Taylor factors associated with these slip systems shows that the grains with slip steps have the lowest Taylor factors. Determination of localized lattice rotations showed a unique behavior in grains with sl...

Tetradentate metalloenediynes with strong imine and weaker thioether coordination serve as a geometrically non-rigid switch to drive thermal Bergman cyclization.

Time-dependent density functional theory shows that the photoreactivities of copper and zinc metalloenediynes derive from multi-configurational excited states involving the enediyne and pyridine π systems.

We report the solvent dependence for the electron transfer kinetics of a cofacial diporphyrin designated as Mg-H 2 , and we show that the high exothermic charge recombinaison rate between the photogenerated Mg + -H 2 - acceptor/donnor pair is governed by solvent dynamics even when the observed electron transfer rate is slow with respect to the solvent motion.

Primary immune responses of ϑ-C3H mouse strains, inbred Swiss Webster (RR) and C57BL/6 to thymic alloantigen ϑ-AKR, as measured by plaque assay detecting IgM-antibody-producing cells, were shown to be under genetic control. F1 hybrids of the high responder, RR, and the low responder, C57BL/6, were intermediate responders. The experiments with backcrosses, F1 × RR and F1 × C57BL/6, suggested that a pair of allelic genes both of which are expressed and which are closely associated with H-2 locus are responsible for the control. The low responder state of C57BL/6 mice could be overcome to a great extent by higher dose of the antigen. Both RR and C57BL/6 mice developed responses of similar magnitude to heterologous erythrocytes. The results of these experiments indicated that the genetic control of anti-ϑ response may be exerted at the level of the initiation of the specific immune response.

SummaryCoelomic parabiosis between mice differing in θ and/or H2 antigens was produced. Spleens of parabionts contained plaque-forming cells involved in the production of antibodies to the partner's antigens. No significant exchange of PFC between partners was noted. Sera of parabionts contained lytic antibodies to the partner's antigens as well as the animal's own antigens. Data supporting the mutual exchange of antibodies were presented. Evidence was obtained that anti-θ antibodies produced in one partner suppress immune response of the other partner whose circulation they entered.

GVHR was elicited in adult F 1 hybrids by iv injection of parental spleen cells. The F 1 hybrids were then immunized with θ-AKR antigen. Plaque-forming cells (PFC) producing antibodies lytic for AKR thymocytes were enumerated in spleens of experimental animals using the method of cytolysis in agar-gel. The number of PFC found in spleens of animals grafted with parental cells was significantly lower than the number in spleens of animals grafted with syngeneic cells. The degree of suppression of immune response to θ-AKR depended on: (1) the duration of GVHR at the time of immunization, (2) the parental strain and the number of parental cells grafted to evoke GVHR, and (3) the source of cells grafted. Thymus and bone marrow cells when grafted together showed a synergistic effect in suppression of the host's immune response. Immunosuppression of the response to θ-AKR seems to be a more sensitive indicator of GVHR in adult F 1 hybrids than splenomegaly, which is commonly used as a means of assessment of GVHR. The possible role of immunosuppression in the pathogenesis of GVHR is briefly discussed.

Horseradish peroxidase-wheat germ agglutinin injected into the superior cerical ganglion is taken up by the neuronal perikarya and transported anterogradely in large quantities into peripheral fibers and axonal terminals in a variety of orofacial and cerebral tissues, including the iris, cornea, pineal gland, facial skin and the adventia of cerebral and facial blood vessels. Subsequent histochemical processing according to the tetramethylbenzidine procedure produces a unique, highly visible intraaxonal marker that makes the identification and 3-dimensional tracing of the sympathetic nerve fibers clear and unambiguous at both the light and electron microscopic levels.

It has been repeatedly described that after a local administration of an antigen the first step of immunological response takes place in the regional lymph node [1, 2, 3, 4]. Cytological changes seen in the lymph node are evidence of the proliferative phase of the response.