Synthesis of esters of saturated and unsaturated sixteen-carbon acids deuterated at the terminal or penultimate carbons

General syntheses of saturated and unsaturated fatty acids, specifically trideuterated at the terminal carbon or dideuterated at the penultimate carbon, from ω-hydroxy esters, have been developed. Methyl [16-²H₃]hexadecanoate was synthesized from methyl 16-hydroxyhexadecanoate. The hydroxyl group was protected as the tetrahydropyranyl ether and the ester group reduced with lithium aluminum deuteride, first to an alcohol and then, by way of the derived mesylate, to a trideuteromethyl group. The new ester group was formed by oxidation of the hydroxyl group. Methyl 16-hydroxy[2-²H₂]hexadecanoate was prepared, from 16-hydroxy-hexadecanoate, by exchange of the α protons and, by the reductive route above, with lithium aluminum hydride, gave methyl [15-²H₂]hexadecanoate. Methyl 16-hydroxy-7-hexadecynoate was synthesized from 6-chlorohexanol and was converted, by means of the above reactions, to methyl [16-²H₃]- and [15-²H₂]-9-hexadecynoates. Lindlar reduction gave methyl [16-²H₃]- and [15-²H₂]cis-9-hexadecenoates. Overall yields ranged from 30% to 38%.     

枸橼酸咖啡因联合肺泡表面活性物质治疗新生儿呼吸窘迫综合征的疗效及对血清BMP-7、CC16、SF水平的影响

目的:探讨枸橼酸咖啡因联合肺泡表面活性物质治疗新生儿呼吸窘迫综合征患儿的疗效及对血清骨形态发生蛋白-7(BMP-7)、Clara细胞分泌蛋白(CC16)、铁蛋白(SF)水平的影响。方法:选择2016年3月到2018年3月我院接诊的新生儿呼吸窘迫综合征患儿90例作为研究对象,以随机数表法分为观察组(n=48)和对照组(n=42)。对照组使用肺泡表面活性物质进行治疗,观察组在对照组的基础上加用枸橼酸咖啡因进行治疗。比较两组治疗后的疗效,治疗前后血清BMP-7、CC16、SF水平、血气指标[氢离子浓度指数(p H)、二氧化碳分压(PCO_2)、氧合指数(PaO_2/Fi O_2)]的变化,通气时间及支气管肺发育不良(BPD)的发生率。结果:治疗后,观察组总有效率为95.83%,明显高于对照组(71.43%,P0.05);两组患儿血清BMP-7、CC16、SF水平较治疗前均显著降低(P0.05),且观察组以上指标均明显低于对照组(P0.05);两组患儿pH、PaO_2/Fi O_2均较治疗前明显升高,而PCO_2较治疗前显著降低(P0.05),且观察组患儿p H、PaO_2/Fi O_2显著高于对照组,而PCO_2明显低于对照组(P0.05)。观察组患儿通气时间明显短于对照组,BPD发生率显著低于对照组(P0.05)。结论:枸橼酸咖啡因联合肺泡表面活性物质治疗新生儿呼吸窘迫综合征的临床效果显著优于单用肺泡表面活性物质治疗,其可有效改善患儿血清BMP-7、CC16、SF水平、缩短机械通气时间,降低支气管肺发育不良发生率。     

Immunological dynamics in response to two anthrax vaccines in mice

In order to understand the variation of humoral and cellular immune responses to A16R live spore and AVA vaccine and to identify efficient immunological parameters for the early evaluation of post immunization in mice, we dynamically monitored the antibody production and cellular responses after the vaccination of Balb/C mice with the anthrax vaccines. The results show that both anti-AVA and anti-Spore antibodies were detectable in the A16R live spore vaccinated group while high titers of anti-AVA antibodies but not anti-Spore antibodies existed in the AVA-immunized group. IgG1 and IgG2 were the major subtypes of IgG in both of the two groups. However, the IgG2a level was significantly higher in the A16R group than in the AVA group. At the cellular level, responses of antigen-specific TH2, TH1 and plasma cells were detected. The peripheral T_H2 responses could be seen on day 5 after vaccination, and remained at a high level throughout the experiment (from day 5 post primary immunization to day 60 post the tertiary immunization); the T_H1 responses to A16R vaccine appeared on day 5, while the responses to AVA could only be detected by day 7 after the secondary immunization; a low level of T_H1 responses could be observed at the end of the experiment. Antigen-specific plasma cells could be found in the peripheral blood of both the immunized groups, however, the responses in the A16R group appeared earlier, lasted longer, and shown an ascending tendency until the end of the experiment when the plasma cell responses in the AVA group were reduced to a very low level. The results suggest that the multiple antigen containing A16R live spore vaccine induces better immune responses than AVA. Combined with serum antibody titers, T_H2, T_H1 and plasma cell responses could be used as immunological parameters for the evaluation of vaccine efficacy. These findings may afford new insight into the early evaluation of vaccination as well as being a powerful strategy for vaccine development.     

Drug Resistance of Enteric Bacteria

A nontransferable R₂₁ (TC) factor was obtained by transduction of R₁₀ (TC.CM.SM.SA) with phage epsilon in group E Salmonella. The R₂₁ (TC) factor acquired transmissibility by the normal conjugal process when group E Salmonella strains harboring R₂₁ (TC) factor were infected with wild-type F or R₁₆ (CM) factor. This transmissibility at high frequency was accounted for by the formation of the recombinant F TC and R₁₀ (CM) TC factors. The F TC and R₁₆ (CM) TC factors were genetically the same as the original F and R₁₆ (CM) factors, except for the ability to confer TC resistance. In the transduction of F TC factor with phage P1, a dF TC (d: defective) factor was obtained that was defective in many F properties, such as the ability to introduce host chromosome and produce male substance, but was capable of transducing TC resistance (dF TC-infection) at low frequency.     

Partitioning Average and Heterotic Components of Direct and Maternal Genetic Effects on Growth in Mice Using Crossfostering Techniques

Crossfostering was performed using lines selected for increased 6-week body weight (H₆) and increased 3-to 6-week postweaning gain (M16) and their reciprocal F₁ crosses as nurse dams in the selected crossfostering group, and base population controls (C₂, ICR) and their reciprocal F₁ crosses in the control group. The offspring suckled were H₆, M16 and F₂ crosses in the selected group, and C₂, ICR and their F₂ crosses in the control group. Measurements taken on the individual offspring were body weights at birth (WB) and at 12, 21, 31, 42, and 63 days (W12, W21, W31, W42 and W63, respectively) and weight gains between adjacent ages (GB-12, G12–21, G21–31, G31–42 and G42–63, respectively). Least squares constants fitted to populations of genetic and nurse dams were used to calculate specific linear contrasts. Correlated responses to selection in average direct genetic effects were significant and positive for all traits examined in both H₆ and M16, while the correlated responses in average maternal genetic effects were negative in M16 and negligible in H₆. Selection response was primarily due to average direct genetic effects while the contribution of average maternal genetic effects was of secondary importance. The response in average direct genetic effects was smaller in M16 than in H₆ through weaning (WB, W12 and W21), but was larger in M16 for postweaning weights (W31, W42 and W63). The correlated responses in average maternal genetic effects were consistently smaller in M16 than in H₆. Direct heterosis was significant for all traits except for G12–21 and G42–63 in the control group, whereas maternal heterosis was significant for weight gains at early ages and for body weights. Direct heterosis tended to be larger than maternal heterosis in both selected and control crosses. Percent direct heterosis for body weight was larger in the selected crosses relative to the control crosses through 31 days of age, but the trend was reversed by 63 days. Percent maternal heterosis was consistently larger in the selected crosses.     

A protein-nucleic acid crosslink in 30S ribosomes

The data indicate that probably a single 30s ribosomal protein has been crosslinked to the 3′-ribosyl terminus of 16s RNA in intact 30s ribosomes. The crosslink was made by oxidizing the 3′-ribosyl moiety of 16s RNA to a dialdehyde with NaIO₄. One of the aldehyde groups generated in the oxidation reacted with an α- or ε-amino group of an adjacent protein to form a Schiff's base. The Schiff's base was reduced with NaBH₄ to a stable, specific covalent crosslink between the protein and the 16s RNA molecules. The crosslinked protein was tentatively identified as S1 according to the nomenclature of Wittmann et al. (1971), Mol. Gen. Genetics 111, 327.     

Prehypertension-Associated Elevation in Circulating Lysophosphatidlycholines,Lp-PLA2 Activity,and Oxidative Stress

Prehypertension is a risk factor for atherosclerosis. We investigated alterations in plasma metabolites that are associated with prehypertension. A group of 53 individuals was identified who remained within the range of prehypertension during repeated measurements in a 3-year period. This group was compared with the control group of 53 normotensive subjects who were matched for age and gender. Metabolomic profiles were analyzed with UPLC-LTQ-Orbitrap mass spectrometry. The prehypertensive group showed higher levels of lysophosphatidylcholines (lysoPCs) containing C14:0, C16:1, C16:0, C18:2, C18:1, C18:0, C20:5, C20:4, C20:3, and C22:6, higher circulating Lp-PLA₂ activity, oxidized LDL (ox-LDL), interleukin 6 (IL-6), urinary 8-epi-PGF_2α, and higher brachial-ankle pulse wave velocity (ba-PWV), before and after adjusting for BMI, WHR, smoking, alcohol consumption, serum lipid profiles, glucose, and insulin. LysoPC (16:0) was the most important plasma metabolite for evaluating the difference between control and prehypertensive groups, with a variable important in the projection (VIP) value of 17.173, and it showed a positive and independent association with DBP and SBP. In the prehypertensive group, the levels of lysoPC (16:0) positively and significantly correlated with ox-LDL, Lp-PLA₂ activity, 8-epi-PGF_2α, ba-PWV, and IL-6 before and after adjusting for confounding variables. Prehypertension-associated elevations in lysoPCs, Lp-PLA₂ activity, ox-LDL, urinary 8-epi-PGF_2α, IL-6, and ba-PWV could indicate increased oxidative stress from Lp-PLA₂-catalyzed PC hydrolysis during increased LDL oxidation, thereby enhancing proinflammation and arterial stiffness.     

Synthesis of 5α-Androstane-3α,16α,17β-triol from 3β-hydroxy-5-androsten-17-one

5α-Androstane-3α, 16α 17β-triol was synthesized from 3β-hy-droxy-5-androsten-17-one. The procedure Involved catalytic hydrogenation of 3β-hydroxy-5-androsten-17-one to 3β-hydroxy-5α-androstan-17-one. This was followed by conversion of the 3β-hydroxy group to 3α-benzoyloxy group by the Mitsunobu reaction. Further treatment with isopropenyl acetate yielded 5α-androsten-16-ene-3α, 17-diol 3-benzoate 17-acetate. This was then converted to 3α, 17-dihydroxy-5α-androstan-16-one 3-benzoate 17-acetate via the unstable epoxide intermediate after treatment with $\text{m}$-cloroperoxybenzoic acid. LiAlH₄ reduction of this compound formed 5α-androstane-3α, 16α, 17β-trlol. ¹H and ¹³C NMR of various steroids are presented to confirm the structure of this compound.     

Altered light conditions during spring: effects on timing of migration and reproduction in migratory redheaded bunting (Emberiza bruniceps)

Photoperiod is the most consistent environmental cue, and therefore, any change in anticipated light environment may affect subsequent response under long days. To test this hypothesis, photosensitive migratory redheaded buntings (Emberiza bruniceps) were exposed to altered photoperiods for 4 weeks [short days (SP, 8L:16D, group 1; control), short days alternated with constant dim light (SP/LL_dim; group 2), constant dim light (LL_dim; group 3) and constant bright light (LL_bright; group 4)] before being transferred to long days (LP; 16L:8D) for 15 weeks. Group differences in long-day-induced responses were observed. The onset of migratory restlessness (Zugunruhe) was earliest in LL_bright but persisted for maximum period in LL_dim group. The LL_dim group attained peak testis size significantly delayed and had more food consumption under long days. The results suggest that the altered photoperiodic exposure during photosensitive stage affects the seasonal phenotypes such as migration and reproduction in migratory buntings.     

9,16-dihydroxy-10-oxo-hexadecanoic acid,a novel component in citrus cutin

When grapefruit cutin was treated with [³H]NaBH₄ and subsequently depolymerized with LiA1H₄, a radioactive component which was more polar than 1,7,16-trihydroxyhexadecane was released. This component was identified by mass specttrometry as 1,7,8,16-tetrahydroxyhexadecane. Mass spectrometry of the tetraols derived from NaBD₄ reduction folllowed by LiAlD₄ depolymerization and from NaBH₄ reduction followed by LiA1D₄ depolymerization indicated that these tetraols were derived from a dihydroxy C₁₆ acid which contained a carbonyl group at C-10 or C-16. Periodate cleavage and permanganate oxidation of the labeled tetraol showed that the ³H was located at C-10. Thus the cutin monomer from which the tetraol was generated was identified as 9,16-dihydroxy-10-oxo-hexadecanoate. This identity was confirmed by NMR analysis of the C₁₆ tetraol obtained by LiA1H₄ reduction of Citrus cutin which had been treated with NaBD₄. This dihydroxyoxo-C₁₆ acid was found to be a minor component of the fruit peel cutin from grapefruit (4.2%), lime (0.1%), lemon (1.2%) and orange (0.3%). 9,10,16-Trihydroxyhexadecanoic acid was also identified as a minor component (0.1–1.9%) in these cutins.     

Sequence-specific chemical modification of chromatin DNA with reactive derivatives of oligonucleotides

Chemical modification of the chromatin DNA with alkylating derivatives of oligothymidylate (pT)₁₆ and oligoadenylate (pA)₁₆ bearing 4-(N-2-chloroethyl-N-methylamino)benzylphosphamide group at the 5-phosphate has been investigated. It was found that the derivatives do react with DNA in chromatin. The reactions occur presumably at the complementary sequences of the DNA since the reaction of the oligothymidylate derivative is inhibited by oligonucleotide (pT)₁₆ taken in excess and is not influenced by hexadecanucleotide of a random structure. Isolated DNA does not react with the oligothymidylate derivative. It is concluded that in chromatin, DNA is partially unwound or possesses some sites which can be opened easily in the presence of complementary oligonucleotides.     

Identification of a novel acetate-utilizing bacterium belonging to Synergistes group 4 in anaerobic digester sludge

Major acetate-utilizing bacterial and archaeal populations in methanogenic anaerobic digester sludge were identified and quantified by radioisotope- and stable-isotope-based functional analyses, microautoradiography-fluorescence in situ hybridization (MAR-FISH) and stable-isotope probing of 16S rRNA (RNA-SIP) that can directly link 16S rRNA phylogeny with in situ metabolic function. First, MAR-FISH with ¹⁴C-acetate indicated the significant utilization of acetate by only two major groups, unidentified bacterial cells and Methanosaeta-like filamentous archaeal cells, in the digester sludge. To identify the acetate-utilizing unidentified bacteria, RNA-SIP was conducted with ¹³C₆-glucose and ¹³C₃-propionate as sole carbon source, which were followed by phylogenetic analysis of 16S rRNA. We found that bacteria belonging to Synergistes group 4 were commonly detected in both 16S rRNA clone libraries derived from the sludge incubated with ¹³C-glucose and ¹³C-propionate. To confirm that this bacterial group can utilize acetate, specific FISH probe targeting for Synergistes group 4 was newly designed and applied to the sludge incubated with ¹⁴C-acetate for MAR-FISH. The MAR-FISH result showed that bacteria belonging to Synergistes group 4 significantly took up acetate and their active population size was comparable to that of Methanosaeta in this sludge. In addition, as bacteria belonging to Synergistes group 4 had high K_m for acetate and maximum utilization rate, they are more competitive for acetate over Methanosaeta at high acetate concentrations (2.5–10 m). To our knowledge, it is the first time to report the acetate-utilizing activity of uncultured bacteria belonging to Synergistes group 4 and its competitive significance to acetoclastic methanogen, Methanosaeta.     

Association of NMT2 with the acyl-CoA carrier ACBD6 protects the N-myristoyltransferase reaction from palmitoyl-CoA

The covalent attachment of a 14-carbon aliphatic tail on a glycine residue of nascent translated peptide chains is catalyzed in human cells by two N-myristoyltransferase (NMT) enzymes using the rare myristoyl-CoA (C₁₄-CoA) molecule as fatty acid donor. Although, NMT enzymes can only transfer a myristate group, they lack specificity for C₁₄-CoA and can also bind the far more abundant palmitoyl-CoA (C₁₆-CoA) molecule. We determined that the acyl-CoA binding protein, acyl-CoA binding domain (ACBD)6, stimulated the NMT reaction of NMT2. This stimulatory effect required interaction between ACBD6 and NMT2, and was enhanced by binding of ACBD6 to its ligand, C_18:2-CoA. ACBD6 also interacted with the second human NMT enzyme, NMT1. The presence of ACBD6 prevented competition of the NMT reaction by C₁₆-CoA. Mutants of ACBD6 that were either deficient in ligand binding to the N-terminal ACBD or unable to interact with NMT2 did not stimulate activity of NMT2, nor could they protect the enzyme from utilizing the competitor C₁₆-CoA. These results indicate that ACBD6 can locally sequester C₁₆-CoA and prevent its access to the enzyme binding site via interaction with NMT2. Thus, the ligand binding properties of the NMT/ACBD6 complex can explain how the NMT reaction can proceed in the presence of the very abundant competitive substrate, C₁₆-CoA.     

The pH dependence of the equilibrium constant KHyd for the hydrolysis of the Lys15-Ala16 reactive-site peptide bond in bovine pancreatic trypsin inhibitor (aprotinin)

ThepH dependence of the equilibrium constant K_Hyd for the hydrolysis of the Lys¹⁵-Ala¹⁶ reactive-site peptide bond of the bovine pancreatic trypsin inhibitor (aprotinin) was investigated over thepH range 2.3–6.5. Solutions of aprotinin, modified aprotinin with the Lys¹⁵-Ala¹⁶ peptide bond cleaved and mixtures of both species were incubated with 10 mol% porcine -trypsin. The state of equilibrium was determined by analytical cation-exchange HPLC. The K_Hyd values obtained did not exactly obey the simple equation of Dobry et al. (1952), which had to be used in an extended form with two additional parameters for a satisfactory fit. ThepH-independent equilibrium constant is 0.90 and thepK values of the Lys¹⁵ carboxyl group and of the Ala¹⁶ amino group are 3.10 and 8.22, respectively. ThepK of an additional group is apparently perturbed by the peptide-bond hydrolysis. It is 4.60 in the native and 4.40 in the modified aprotinin.     

Prostaglandins and congeners IX (1). The synthesis of 15-deoxy-16-,17-, or 20-hydroxyprostaglandins and 15-deoxy-15-hydroxymethylprostaglandin E2

Prostaglandin congeners wherein the 15-hydroxy group is moved to the C₁₆, C₁₇, or C₂₀ position or is replaced by a hydroxymethyl group were prepared the 1,4-addition of a lithium trialkyl- -alkenyl alanate to an appropriate cyclopentenone. Several of the 16-hydroxy derivatives showed significant activity as constrictors of the isolated gerbil colon and in bronchodilator and anti-secretory assays.     

Abnormally High Nourishment During Sensitive Periods Results in Body Weight Changes Across Generations

Objective : This study asked whether a brief period of over-nutrition during a developmentally sensitive time could impact the individual's adult weight and that of succeeding generations. Research Methods and Procedures : Female rat pups (F₁ generation) were randomly assigned to 1 of 3 groups: (1) a control group that was naturally reared by mothers; (2) another control group implanted with chronic gastric fistulas on postnatal day 4 and fed enough formula to match the growth of the mother-reared group; and (3) an experimental group gastrostomized and infused from day 8 through day 16 with a greater quantity of food than gastrostomy-reared controls (OF). On postnatal day 16, both gastrostomy-reared groups were returned to normal litters. Adult F₁ females from overfed and mother-reared groups were bred with normal males to yield an F₂ generation. F₂ adult females were bred to normal males to produce an F₃ generation. Results : When adult, the F₁ experimental group was heavier than control groups. F₂ adults from OF mothers were smaller than those from the control group. F₃ animals from OF grandmothers were heavier at weaning than F3 descendants from mother-reared animals. Discussion : Excess nourishment during a developmentally sensitive period changed the metabolic phenotype of one generation so dramatically that the gestational development and subsequent phenotype of two succeeding generations were also changed. The experiment models fetal effects of gestational diabetes in humans and may help to elucidate how, independent of genetic anomalies, secular changes can be detected across generations.     

The effects of synthetic prostaglandin analogs on canine hepatic bile flow

The synthetic prostaglandin analogs 16, 16-dimethyl PGF_2α and 16, 16-dimethyl PGE₂ were administered to dogs with chronic biliary and gastric fistulas. The effects of 16, 16 diMePGF_2α and 16, 16 diMePGE₂ were evaluated on bile flow and composition and bile adenosine 3′, 5′ monophosphate (cyclic AMP) secretion. 16, 16 diMePGF_2α in doses of 0.125 and 0.25 μg-kg-min significantly increased hepatic bile flow. The choleresis was characterized by increased cloride and bicarbonate secretion. Measurement by radioimmunoassay of bile cyclic AMP concentration demonstrated no evident increase in bile cyclic AMP secretion associated with the choleresis produced by 16, 16 diMePGF_2α. The administration of 16, 16 diMePGE₂ in a dose range 0.01 to 1.0 μg-kg-min did not significantly alter bile flow rates or composition. Bile erythritol-¹⁴C clearance, a measure of canalicular bile flow, was significantly increased by PGF_2α but not by 16, 16-dimethyl PGF_2α, suggesting that the mechanism of action of PGF_2α in stimulating hepatic bile flow may be different from that involved in 16, 16-dimethyl PGF_2α choleresis. The results of this study indicate that the synthetic PGF_2α analog produces a choleretic response not mediated by adenylate cyclase and associated with increased chloride and bicarbonate secretion.     

Analysis of Photosynthetic Antenna Function in a Mutant of Arabidopsis thaliana (L.) Lacking trans-Hexadecenoic Acid

Several lines of evidence support the proposal that the unusual chloroplast-specific lipid acyl group Δ3,trans-hexadecenoic acid (trans-C_16:1) stimulates the formation or maintenance of the oligomeric form of the light-harvesting chlorophyll a/b complex (LHCP). To assess the functional significance of this apparent association we have analyzed LHCP structure and function in a mutant of Arabidopsis thaliana (L.) which lacks trans-C_16:1 by electrophoretic analysis of the protein-chlorophyll complexes and by measurements of chlorophyll fluorescence under a variety of conditions. By these criteria the putative oligomeric form of LHCP appears to be slightly more labile to detergent-mediated dissociation in the mutant. The oligomeric PSI chlorophyll-protein complex, associated with PSI, was also more labile to detergent-mediated dissociation in the mutant, suggesting a previously unsuspected association of trans-C_16:1 with the PSI complex. However, no significant effect of the mutation on the efficiency of energy transfer from LHCP to the photochemical reaction centers was observed under any of the various conditions imposed. Also, the stability of the chlorophyll-protein complexes to temperature-induced dissociation was unaffected in the mutant. The role of trans-C_16:1 is very subtle or is only conditionally expressed.     

Prostaglandins and congeners IX (1). The synthesis of 15-deoxy-16-, 17-, or 20-hydroxyprostaglandins and 15-deoxy-15-hydroxymethylprostaglandin E2

Prostaglandin congeners wherein the 15-hydroxy group is moved to the C₁₆, C₁₇, or C₂₀ position or is replaced by a hydroxymethyl group were prepared via the 1,4-addition of a lithium trialkyl-trans-alkenyl alanate to an appropriate cyclopentenone. Several of the 16-hydroxy derivatives showed significant activity as constrictors of the isolated gerbil colon and in bronchodilator and anti-secretory assays.     

Clinical isolates of <Emphasis Type="Italic">Nocardia brasiliensis</Emphasis> from Japan exhibit variable susceptibility to the antibiotic imipenem

Clinical isolates of Nocardia brasiliensis from Japan were classified into two groups based on their susceptibility to the carbapenem antibiotic, imipenem (IPM). Of 33 strains tested, 10 belonged to an IPM susceptible group, with MIC of from 0.25 to 2 εg/ml and a MIC₈₀ value of 1.5 εg/ml for this antibiotic. The remaining 23 strains belonged to an IPMresistant group with MIC and MIC₈₀ values of 8–16 εg/ml and >16 εg/ml, respectively. The type strain of N. brasiliensis belonged to this resistant group. Analysis of 16S rDNA genes sequences showed that the IPM susceptible group had characteristic single nucleotide substitutions at positions 103 (T), 381 (A), and 456 (A), in contrast to the IPM resistant group. This grouping, however, was not associated with their clinical manifestation.