Studies of the oxidation of ethanol to acetaldehyde by oxyhemoglobin using fluorigenic high-performance liquid chromatography

We noted a rise in acetaldehyde levels in clinical samples of venous whole blood containing ethanol that did not occur in samples from teetotalers. Experiments were performed to define the mechanism involved in acetaldehyde production. The addition of 0.10% ethanol to whole blood produced an immediate increase in acetaldehyde due to acetaldehyde in the stock solution followed by a subsequent increase that became statistically significant by 48 hr. Separation of blood into components documented that the increase in acetaldehyde was associated with the red cell but not plasma fraction. Incubation of isolated hemoglobin with ethanol produced a rise in acetaldehyde levels. Incubation of oxygenated whole blood with ethanol produced a linear increase in acetaldehyde, whereas nitrogen-exposed blood produced no increase. The rise of acetaldehyde in the presence of ethanol was dependent on the concentration of oxygenated hemoglobin A0. Addition of inhibitors of catalase, alcohol dehydrogenase, and glycolytic enzymes (aminotriazole, azide, pyrazole, sodium fluoride, sodium citrate, and iodoacetate) did not inhibit the rise of acetaldehyde, but addition of the hemoglobin ligand cyanide abolished the rise in acetaldehyde. Kinetic analysis with oxygenated whole blood plus inhibitors revealed a Km of 2.5 mM and Vmax of 1.42 microM/min. We conclude that oxyhemoglobin contributes to the metabolism of ethanol to acetaldehyde. These findings may explain in part the high levels of acetaldehyde found in red cells compared with plasma. The results also have implications for the optimum storage of blood samples for acetaldehyde analysis.     

Studies on the formation of acetoin from acetaldehyde by the pyruvate dehydrogenase complex and its regulation

1. Pyruvate dehydrogenase complex was isolated from pigeon breast muscle involving steps of isoelectric precipitation, poly(ethyleneglycol) fractionation and separation on a glycerine gradient in the ultracentrifuge. 2. Arsenite, a potent inhibitor of the dihydrolipoyl transcetylase, did not affect the formation of acetoin from acetaldehyde, indicating that the pyruvate dehydrogenase component was operative in this reaction. 3. Production of acetoin by the pyruvate dehydrogenase complex is subject to regulation by phosphorylation and dephosphorylation, the dephosphorylated form only being active. 4. The inhibition by acetaldehyde of the pyruvate dehydrogenase complex could be partly explained by the formation of acetoin as an alternative reaction.     

Studies of the interfacial kinetics of the reaction of nitrogen with liquid iron by the15N-14N isotope exchange reaction

The rate of dissociation of N₂ on high purity liquid iron and iron-sulfur alloys between 1550 and 1650 °C has been studied by means of the¹⁵N-¹⁴N exchange reaction. It is shown that the rate constants at given sulfur concentrations are consistent with those for the absorption of nitrogen into iron-sulfur alloys, indicating a common rate determining step. The rate constant for high purity liquid iron, in units of mol cm^?2 s^?1 aim^?1, is given by: logk _f = ?340/T ? 1.38. The rate constant is found to be independent of carbon concentration up to about 4.3 wt pct and to be closely consistent with ideal chemisorption kinetics. The results are combined with those of previously published studies to give rational equations for the apparent rate constants for Fe-S and Fe-O alloys. Consistent values for the adsorption coefficients at 1600 °C for sulfur and oxygen are deduced to be about 130 and 220, respectively, for a standard state of the 1 wt pct ideal solution.     

Studies on inactivation of hepatitis B virus with polymerase chain reaction

Polymerase chain reaction-ethidium bromide (PCR-EB) method for detecting hepatitis B virus DNA (HBV-DNA) was established with good specificity and a detection limit of 1 pg HBV-DNA, minimum HBV infection dose in susceptible animal, chimpanzees, could be detected with it. Determination of inactivation of HBV-DNA could be inactivated with active chlorine 1,250 mg/L for 60 minutes, or 2,500 mg/L for 30 minutes, 10 pg HBV-DNA in purified Dane particles could be inactivated by active chlorine 625 mg/L for 10 minutes. Accordingly, use of PCR to evaluate the effects of chlorine disinfectant in inactivating HBV was feasible, and HBV-DNA was a more reliable index for inactivation of HBV than HBsAg.     

Studies of the interfacial kinetics of the reaction of CO2 with liquid iron by the14CO2-CO isotope exchange reaction

The rate of dissociation of CO₂ on liquid iron between about 1540 and 1740 °C and at CO/CO₂ ratios of 6.7 to 100 has been studied by means of the¹⁴CO₂-CO exchange reaction. It is shown that for essentially pure iron the rate constant at low oxygen potential is consistent with that for the decarburization of liquid iron by CO₂, indicating a common rate determining step. The influence of the gas composition on the rate is found to be consistent with surface blockage by adsorbed oxygen which obeys an ideal Langmuir adsorption isotherm over the experimentally accessible conditions. The adsorption coefficient for oxygen with respect to the infinitely dilute solution with 1 wt pct as standard state is deduced to be given by: logK′_o = 11270/T – 4.09 The value of K′_o at 1550 °C is found to be in good accord with the available data for the depression of the surface tension of liquid iron by oxygen. A. W. Cramb, Formerly with the Department of Materials Science and Engineering, University of Pennsylvania     

Teratogenic effects of acetaldehyde in the rat

Acetaldehyde, the proximal metabolite of ethanol, was administered intraperitoneally in single and triple doses (50, 75, 100 mg/kg) to pregnant CF rats on days 10, 11 and 12 of gestation and fetuses were collected on day 21. Besides significant fetal resorptions, malformations were found which included edema, microcephaly, micrognathia, micromelia, hydrocephaly, exencephaly, hemorrhages etc. Somatometric measurements of fetuses (i.e. crown rump length, transumbilical distance and tail length) revealed significant growth retardation. Alizarin red-stained skeletal preparations showed considerable stunting. The placental weight and umbilical cord length were also significantly reduced. The close similarity of the pattern of acetaldehyde-induced fetal malformations with those resulting from maternal alcohol consumption during pregnancy is suggestive of the possible implication of acetaldehyde in the fetal alcohol syndrome.     

5-安替比林偶氮水杨基荧光酮的合成及其与钨显色反应的研究

报道了新试剂5-安替比林偶氮水杨基荧光酮(APASF)的合成方法,研究了在表面活性剂十六烷基三甲基溴化铵(CTMAB)存在下试剂与钨的显色反应。将4-氨基安替比林重氮化制得重氮盐溶液,然后水杨醛与重氮盐反应合成安替比林偶氮水杨醛,将事先合成的偏三酚三乙酸酯与安替比林偶氮水杨醛反应合成APASF,并用红外光谱分析法对其进行表征。产率为40%。在酸性介质中,表面活性剂十六烷基三甲基溴化铵(CTMAB)存在下,试剂与钨生成络合物的最大吸收波长为520 nm,表观摩尔吸光系数为7.4×104L.mol-1.cm-1,钨的质量浓度在0.1～1.0μg/mL范围内符合比尔定律。方法用于标准钢样中钨的测定,测得值与认定值相符。     

乙醛-双环已酮草酰二腙光度法测定纯铝中铜

多年来,我厂化验室分析纯铝中铜含量采用双环已酮草酰二腙(BCO)光度法[1],该方法虽有较好的选择性和较高的灵敏度(ε610=1·6×104),但溶液的酸度要求较高(pH 9·1~9·7),且稳定性不好,测定准确度较低。经试验后,在原体系中加入乙醛,铜生成紫红色络合物,最大吸收峰由610 nm移至540 nm,摩尔吸光系数为2·3×104,稳定性也较好。1实验部分1·1主要仪器和试剂721型分光光度计;酸度计;150 mL银皿或银烧杯。氢氧化钠溶液:250 g/L;硝酸:1 1;氢氧化铵:1 1;柠檬酸钠溶液:500 g/L;乙醛:体积分数为40%;BCO溶液:1·0 g/L,称取0·1 g BCO试剂,加50 …     

Soluble proteins modified with acetaldehyde and malondialdehyde are immunogenic in the absence of adjuvant

Recent studies have shown that the alcohol metabolites malondialdehyde and acetaldehyde can combine to form a stable adduct (MAA) on proteins. This adduct has been detected in the livers of rats chronically consuming ethanol, and serum antibodies to MAA have been observed at significantly higher concentrations in ethanol-fed when compared with pair-fed or chow-fed control rats. More recently, preliminary studies have strongly suggested that the MAA adduct is capable of stimulating antibody responses to soluble proteins in the absence of adjuvants. The antibodies produced recognize either the MAA epitope or the carrier protein itself. Therefore, it was the purpose of this study to examine the potential immunogenicity of MAA-modified exogenous proteins in the absence of adjuvants. Balb/c mice were immunized in the presence or absence of adjuvant with different concentrations of unmodified or MAA-modified proteins. The antibody response to both the MAA epitope and unmodified protein epitopes were determined by ELISA. In the absence of adjuvant, significant antibody responses were induced to both the MAA epitope and nonmodified protein epitopes. Smaller immunizing doses of MAA-protein conjugate favored the production of antibodies to nonmodified proteins, whereas larger doses induced a strong anti-MAA response. In studies to begin determining a mechanism for the specificity of the response in the absence of adjuvants, peritoneal macrophages were found to bind and degrade MAA-adducted proteins through the use of a scavenger receptor. This indicated that MAA-adducted proteins may be specifically taken up and epitopes presented to the humoral immune system in the absence of adjuvants. Importantly, these are the first data showing that an alcohol-related metabolite can induce an antibody response in the absence of adjuvant and suggesting a mechanism by which antibody to the MAA adduct or its carrier (exogenous or endogenous) proteins may be generated in vivo.     

Studies of lysophospholipids related to the hamster sperm acrosome reaction in vitro

1. One of the metabolic features of acquired immunodeficiency syndrome is increased tissue glucose uptake documented by euglycaemic-hyperinsulinaemic clamp studies, suggesting increased insulin sensitivity. However, these results may also be related to the confounding effect of increased non-insulin-mediated glucose uptake in acquired immunodeficiency syndrome, which will result in an erroneously presumed increased insulin sensitivity. To study the contribution of non-insulin-mediated glucose uptake to total tissue glucose uptake in acquired immunodeficiency syndrome, we conducted a hypoinsulinaemic clamp study in clinically stable human immunodeficiency virus-infected (Centers for Disease Control class IV) men (n = 7) and healthy subjects (n = 5). Glucose uptake was measured by a primed, continuous infusion of [3-3H]glucose in the postabsorptive state and during somatostatin-induced insulinopenia at euglycaemic (approximately 5.3 mmol/l) and hyperglycaemic (approximately 11 mmol/l) glucose concentrations. 2. Basal glucose concentration (patients, 5.2 +/- 0.1 mmol/l; control subjects, 5.3 +/- 0.1 mmol/l) and basal glucose tissue uptake (patients, 15.9 +/- 0.5 mumol min-1 kg-1 fat-free mass; control subjects, 15.2 +/- 0.4 mumol min-1 kg-1 fat-free mass) were not different between the two groups. 3. Euglycaemic glucose uptake during somatostatin infusion, reflecting non-insulin-mediated glucose uptake, decreased to 82 +/- 3% in patients and 78 +/- 2% in control subjects (not significant). Under hyperglycaemic (approximately 11 mmol/l) conditions with sustained insulinopenia, no differences in glucose uptake existed between the two groups (patients, 16.8 +/- 0.6 mumol min-1 kg-1 fat-free mass; control subjects, 16.1+/- 0.3 mumol min-1 kg-1 fat-free mass).(ABSTRACT TRUNCATED AT 250 WORDS)     

Studies in gas-solid reactions: Part I. A structural model for the reaction of porous oxides with a reducing gas

A structural model is presented for describing the reaction of a porous metal oxide pellet with a reducing gas. It is suggested that the pellet is made up of a large number of grains and the overall rate of reaction is computed by summing the contributions of all these individual grains. The model thus incorporates structural parameters, such as grain size, porosity (pore size distribution) and allows a quantitative assessment of the role played by these quantities in determining the rate of progress of the reaction.     

Characterization of the production of acetaldehyde by astrocytes in culture after ethanol exposure

Mice selected for large and small brain weights (LB and SB strains, respectively) were tested for audiogenic seizure sensitivity. We have examined 150 LB and 120 SB mice of the 13th and 14th generations. In mice of the 12th generation brain and body weight values were 498.6 +/- +/- 2.1 mg and 26.2 +/- 0.4 g, respectively, for the LB and 415.35 +/- 1.9 mg and 23.8 +/- 0.3 g for the SB, the difference being significant for both values (p < 0.001). The SB mice revealed higher audiogenic sensitivity (larger proportion of seizures and deaths) at the age of 22-27 days. Adult LB mice were more sensitive than SB of the same age (irrespective of whether they received priming stimulation or not). The obtained evidence is discussed in the context of differences between audiogenic fits and other seizure states.     

On the reaction of solids with mixed gases

A mathematical formulation is presented, describing the rate of reaction of porous solids with mixed gases in regimes when the overall rate is controlled by pore diffusion or by external mass transfer. The reduction of metal oxides with a hydro gen-carbon monoxide mixture is a typical example of such systems. In the formulation, proper account was taken of the coupled nature of the fluxes, by writing the Stefan-Maxwell equations to represent the diffusion process. The overall rates obtained from the numerical solution of these simultaneous differential equations were compared with those calculated using a much simpler procedure, involving the concept of the pseudobinary diffusion coefficient. The maximum discrepancy between the total reducing gas flux obtained by these two methods was only some 15 pct at intermediate gas compositions. However, much more substantial discrepancies were obtained regarding the transfer of the individual components. Formerly Graduate Student, Department of Chemical Engineering, State University of New York at Buffalo     

On the reaction of solids with mixed gases

A mathematical formulation is presented, describing the rate of reaction of porous solids with mixed gases in regimes when the overall rate is controlled by pore diffusion or by external mass transfer. The reduction of metal oxides with a hydrogen-carbon monoxide mixture is a typical example of such systems. In the formulation, proper account was taken of the coupled nature of the fluxes, by writing the Stefan-Maxwell equations to represent the diffusion process. The overall rates obtained from the numerical solution of these simultaneous differential equations were compared with those calculated using a much simpler procedure, involving the concept of the pseudobinary diffusion coefficient. The maximum discrepancy between the total reducing gas flux obtained by these two methods was only some 15 pct at intermediate gas compositions. However, much more substantial discrepancies were obtained regarding the transfer of the individual components. Y. EL-TAWIL, Formerly Graduate Student, Department of Chemical Engineering, State University of New York at Buffalo,