Reactivities of the coordinated organonitriles in molybdenum(0) and tungsten(0) phosphine complexes: protonation of the nitrile carbon and cleavage of the CN triple bond

The molybdenum and tungsten dinitrogen-organonitrile complexes trans-[M(N₂)(NCR)(dppe)₂] (2, M=Mo; 4, M=W; R=Ph, C₆H₄Me-p, C₆H₄OMe-p, Me; dppe=Ph₂PCH₂CH₂PPh₂) underwent double protonation at the nitrile carbon atom with loss of N₂ and a change in oxidation state to +4 on treatment with hydrochloric acid to afford the cationic imido complexes trans-[MCl(NCH₂R)(dppe)₂]⁺. The solid-state structure of trans-[WCl(NCH₂CH₃)(dppe)₂][PF₆]·CH₂Cl₂ was determined by single-crystal X-ray analysis. Protonation of complexes 2 by fluoroboric acid or hydrobromic acid also formed the similar imido complexes trans-[MoX(NCH₂R)(dppe)₂]⁺ (X=F, Br). In contrast, the dinitrogen complex trans-[Mo(N₂)₂(dppe)₂] reacted with two equiv. of benzoylacetonitrile, a nitrile with acidic CH hydrogen atoms, to give the nitrido complex trans-[Mo(N)(NKCCHCOPh)(dppe)₂] (12), which was accompanied by evolution of dinitrogen and the formation of 1-phenyl-2-propen-1-one in high yields. For complex 12, the zwitterionic structure, where the anionic enolate ligand PhC(O⁺)=CHCN coordinates to the cationic Mo(IV) center through its nitrogen atom, was confirmed by spectroscopic measurements and single-crystal X-ray analysis. A unique intermolecular aromatic C---HO hydrogen bonding was observed in that crystal structure. Complex 12 is considered to be formed via the cleavage of the CN triple bond of benzoylacetonitrile on the metal. A reaction mechanism is proposed, which includes the double protonation of the nitrile carbon atom of the ligating benzoylacetonitrile on a low-valent molybdenum center.     

Aquopentacyanoferrate (II): an effective probing electron donor in the conversion of oxyhemoglobin to methemoglobin and peroxide.

HbA O₂ reacts readily with Fe^II(CN)₅H₂O^3? to form aquometHb and peroxide via a second order process: rate=k[HbO₂][Fe^II(CN)₅H₂O^3?]. A slight enchancement in the rate of metHb formation due to the H₂O₂ produced can be prevented by addition of catalase. The reaction is free from complications exhibited by other reductants. The hexacyanide, ferrocyanide, reacts with HbA O₂ but at only ca. 0.02% the rate and with formation of cyanometHb. Reductants such as phenols and sulfa drugs may produce radicals that can enter into side reactions. Fe^II(CN)₅H₂O^3? shows promise as an effective probing reagent for the characterization of H₂O₂ production from oxygenated heme and other proteins.     

Cd-Binding Complexes from the Root Tissues of Various Higher Plants Cultivated in Cd2+-Containing Medium

Stone parsley, soybean, sunflower, sweet potato, potato, andadlay cultivated in a Cd²⁺-containing medium had Cd-bindingcomplexes with molecular weights of about 4,000 in the roottissues. The complexes were similar to the complex previouslyfound in water hyacinth roots in their absorption and CD spectraand their amino acid compositions. The results indicate thewidespread existence of complexes similar to fission yeast Cd-BPlin roots of various plants. (Received June 30, 1986; Accepted December 18, 1986)     

Acetazolamide: maternal toxicity, pattern of malformations, and litter effect

Thirty litters of C57BL 6J mice were administered intraperitoneally one of four doses (0, 500, 750, and 1,000 mg/kg maternal weight) of acetazolamide on day 9 of gestation. The fetuses were removed on day 18 and fixed, stained, cleared, and examined for the pattern of malformations. The forelimb postaxial limb deficiency was the most common abnormality, but forelimb postaxial polydactyly and a postaxial deficiency in the hindlimb were also observed. Males were significantly more likely to be malformed than females at all doses, in contrast to the predominance of females observed in rat fetuses exposed to acetazolamide (Scott et al.: Teratology 6:239-240, '73). The occurrence of limb malformations did not correlate with maternal weight loss, the birth weight of the fetus, or the position of the fetus in the uterus. A "litter effect" was demonstrated in that there was a nonuniform distribution of litters with different proportions of malformed fetuses.     

Clinical studies on cell-mediated immunity in patients with renal cell carcinoma: interleukin-2 and interferon-γ production of lymphocytes

Summary The authors examined interleukin-2 (IL-2) production and interferon (IFN) production of peripheral blood mononuclear cells in 28 patients with renal cell carcinoma and 17 control subjects. The peripheral blood was obtained prior to the initiation of therapeutic procedures. The patients were divided into two groups according to tumor size, 5 cm and >5 cm. The production of IL-2 and IFN was measured by immunoradiometric assay. As a result, in the patients with tumors >5 cm, IL-2 and IFN production was impaired. However, in the patients with tumors 5 cm, IFN production was enhanced, though IL-2 production was not significantly different from that of the control subjects. There was no significant correlation between IL-2 production and IFN production.     

Enhancement of tissue plasminogen activator production from human normal fibroblast IMR-90 cells by limitation of cell growth

Summary Tissue plasminogen activator (t-PA) production induced by proteose peptone from IMR-90 cells was investigated. Cells monolayered on plastic surfaces had a higher ability to produce t-PA per unit cell compared to those grown tri-dimensionally on ceramic pieces. Furthermore, confluent monolayers of the cells, which suffered contact inhibition and resulted in limited growth, were available for t-PA production. Repeated batch production with microcarriers, on which the cells were almost confluent monolayers similar to those in T-flasks, was performed. Utilization of the cells, which had limited serum in the growth phase, resulted in an increase in production. Moreover, dilution of the basal components of the medium at initiation of the production phase markedly promoted t-PA production. The volumetric productivity was stable for 30 days at 100 IU/cm³ per day. The cells were then mostly retained on microcarriers. Thus, an effective and scalable method of t-PA production by normal fibroblast cells was developed. Offprint requests to: S. Mitsuda     

The kinetics of the first wave of spermatogenesis in the newborn male mouse

A combination of autoradiography and air-dried techniques was used to calculate the duration of the major meiotic stages in the first wave of spermatogenesis in the newborn mouse. The data indicated that the entry into meiosis occurred asynchronously over 2 days, and the time required for each stage and the total cycle was constant. These time intervals were nearly identical with those estimated for adult animals in the present study and by other authors.     

Plasma concentration of prolactin during four-day osmotic pump infusion of thyrotropin-releasing hormone and vasoactive intestinal polypeptide in rats

Pituitary prolactin (PRL) responses to 4-day continuous infusion of thyrotropin-releasing hormone (TRH) and vasoactive intestinal polypeptide (VIP) were investigated in unanesthetized male rats using Alzet osmotic minipumps. The TRH dose infused was 3.6 micrograms/day and the VIP dose was 32.8 micrograms/day. Infusion of TRH with osmotic pumps elevated the plasma PRL level compared to controls over the 4-day infusion period. However, mean levels of PRL tended to decrease during the 4-day infusion. On the other hand, continuous VIP infusion elicited a significant continuous PRL release over the 4-day infusion period. Thus, it may be said that the PRL responses to infused TRH and VIP were maintained during the 4-day infusion.     

Selective enhancement in striatal [H]nitrendipine binding following chronic treatment with morphine

Two parameters of Ca²⁺ dynamics in brain preparations (⁴⁵Ca-uptake to slices and [³H]nitrendipine binding to membrane fractions) were measured in naive and chronic morphine-administered rats. While morphine did not have any effect on ⁴⁵Ca-uptake to striatal slices in normal Krebs-Ringer solution, it inhibited K⁺-stimulated ⁴⁵Ca-uptake to slices. Furthermore, the effect of morphine was antagonized by naloxone. Inhibition of K⁺-stimulated ⁴⁵Ca-uptake to striatal slices by morphine was not observed in preparations obtained from chronic morphine-administered rats (6 mg/kg/b.i.d./7 days). In membrane fractions, [³H]nitrendipine binding increased by 34% in striatum following chronic morphine treatment, whereas no change was observed in the cortex and hippocampus. The results will be discussed in relation to the phenomena underlying chronic morphine administration.