Bicarbonate: carbon-dioxide regulation of sperm capacitation, hyperactivated motility, and acrosome reactions

The bicarbonate: CO2 (HCO3-:CO2) concentration dependencies of hamster sperm motility, spontaneous acrosome reactions, and zona penetration (used to assay the zona-induced acrosome reaction) were examined. A cross-over experimental design was used to segregate effects on early stages of capacitation, spanning the first 5 h of incubation, from those on acrosome reactions and zona penetration during the last 1 h. After 5 h, HCO3-:CO2 concentrations were increased, decreased, or kept the same for 1 h. Compared to no HCO3-:CO2, as little as 2.9 mM: 0.6% HCO3-:CO2 increased the sperm motility index (MI) by 2.7-3.6 times. When HCO3-:CO2 was continuously present, both progressive and hyperactivated motility were stimulated by HCO3-:CO2 in a dose-dependent manner by 3-4 h, well before completion of capacitation. Stimulation of acrosome reactions or zona penetration, by addition of HCO3-:CO2 to sperm for 1 h late in capacitation, depended mainly on levels of HCO3-:CO2 present earlier in capacitation. When 25 mM: 5% HCO3-:CO2 was added only at 5 h, responses were significantly lower than with sperm treated continuously with the same concentration of HCO3-:CO2, being 2.5 times lower for MI, 2 times lower for acrosome reactions, and 6.3 times lower for zona penetration. In contrast, decreasing HCO3-:CO2 to suboptimal levels after 5 h did not decrease any 6-h sperm responses significantly. The average maximal and one-half maximal preincubation HCO3- concentrations for all responses were 34.2 +/- 1.0 and 9.2 +/- 0.3 mM, respectively. Zona penetration and hyperactivation were highly correlated.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fine needle aspiration cytology of reactions in leprosy.

OBJECTIVE: To define diagnostic cytomorphologic features of reactions in leprosy. STUDY DESIGN: Part-retrospective, part-prospective, single-blind, controlled study of the applicability of fine needle aspiration cytology in the diagnosis of reactions in leprosy. Cytomorphologic features were compared in 42 clinically diagnosed patients with reactions in leprosy with those in a control group of patients with nonreactional leprosy. The study groups included type 1 and type 2 reactions in 35 and 9 patients, respectively. May-Grünwald-Giemsa and Ziehl-Neelsen staining methods were employed. RESULTS: Statistically significant (P < .01) cytomorphologic features of type 1 reaction were the presence of fragments of collagen and elastin; giant cells; giant cells exhibiting elastin phagocytosis; loose, epithelioid cell granulomas; and fibroblasts. Type 2 reaction was characterized in aspirates by the presence of an abundance of neutrophils in a background of lepromatous leprosy (P < .01). CONCLUSION: Criteria that are used in histopathology for the diagnosis of leprosy reactions can be applied satisfactorily to cytologic smears. A good correlation between clinical diagnosis and cytomorphology can be achieved. Multiple-site aspirates from the skin, nerve and lymph nodes are helpful in substantiating the diagnosis.     

Separation and characterization of pyrimidine deoxyribonucleoside 2'-hydroxylase and thymine 7-hydroxylase from Aspergillus nidulans

Partially purified preparations from Aspergillus nidulans were shown to catalyze two alpha-ketoglutarate dependent dioxygenase reactions: the pyrimidine deoxyribonucleoside 2'-hydroxylase (EC 1.14.11.3) and the thymine 7-hydroxylase (EC 1.14.11.6) reactions. These reactions showed an absolute requirement for alpha-ketoglutarate and molecular oxygen and were stimulated by Fe(II), ascorbate and catalase. Both reactions demonstrated a stoichiometry such that for each mole of substrate (deoxyribonucleoside or pyrimidine) hydroxylated one mole of CO2 was produced from alpha-ketoglutarate. These two activities were separated using DEAE-Sephacel chromatography.     

Nucleophile specificity in alpha-chymotrypsin- and subtilisin-(Bacillus subtilis strain 72) catalyzed reactions.

Nucleophilic properties of amino-acid amides were studied systematically in acyl-transfer reactions catalyzed by alpha-chymotrypsin and subtilisin from Bacillus subtilis strain 72 (subtilisin 72) using Mal-L-Ala-L-Ala-L-PheOMe as the acyl-group donor. In alpha-chymotrypsin-catalyzed reactions, the nucleophile reactivities increase in the following order: D-AlaNH2 < GlyNH2 < L-AlaNH2 < L-SerNH2 < L-ThrNH2 < L-HisNH2 < L-ValNH2 < L-LeuNH2 < L-TrpNH2 < L-MetNH2 < L-NvaNH2 < L-PheNH2 < L-IleNH2 < L-TyrNH2 < L-ArgNH2. In reactions catalyzed by subtilisin 72, the reactivities increase as follows: L-LeuNH2 < L-IleNH2 < L-ThrNH2 < L-ArgNH2 < L-TrpNH2 < L-NvaNH2 < L-ValNH2 < L-MetNH2 < L-AlaNH2 < L-SerNH2 < D-AlaNH2 < GlyNH2. In alpha-chymotrypsin-catalyzed reactions, hydrophobic interactions are entirely responsible for the differences between the reactivity of the nucleophiles for amides of all the amino-acids tested with the exception of D-AlaNH2, L-ArgNH2 and L-TyrNH2. In reactions catalyzed by subtilisin 72, amino-acid side-chain characteristics and the nucleophile reactivities are not related. The data obtained show the low selectivity of the S1' subsite of subtilisin 72 and high specificity of this subsite in alpha-chymotrypsin.     

Kinetic studies of mobilization of copper(II) from human serum albumin with chelating agents

The kinetics of the mobilizing reactions of five chelating agents for human serum albumin (HSA)-bound copper(II) [Cu(II)] have been studied spectrophotometrically. The decreasing sequence of reaction rate has been determined to be EDTA greater than DTPA greater than EGTA greater than NTA greater than IDA. A group of mathematical models were established to define the mechanisms of the competitive reactions between low-molecular-weight ligand and macromolecular ligand. All reactions of the five chelating agents follow a process involving the intermediate ternary complexes: (formula; see text) The reactions of DTPA and EDTA were found to be different from those of EGTA, NTA, and IDA. In the former cases, the reactions are likely following an overlapping mechanism in which the rate constant k1 was closed to k2. The reactions involving the other three chelators are different in k1 much greater than k2.     

RhD正定型及不规则抗体筛查的临床意义分析

目的:探究RhD正定型及不规则抗体筛查在预防临床输血不良反应中的应用价值及临床意义。方法:回顾性分析2010年至2011年、2017年至2018年于首都医科大学附属北京同仁医院输血科实施输血治疗的1892例患者,将2010年至2011年未实施Rh D正定型及不规则抗体筛查时输血治疗的901例患者设为对照组,将2017年至2018年实施RhD正定型及不规则抗体筛查后输血治疗的991例患者设为观察组。对比两组输血不良反应发生率,分析不同血液成分、不同性别、不同年龄输血不良反应发生率,并就2017年、2018年受血者RhD正定型及不规则抗体特异性分布进行罗列。结果:(1)2010年输血不良反应发生率为3.49%,2011年为2.40%,2017年为1.33%,2018年为0.74%,对照组不良反应发生率明显高于观察组(P<0.05)。(2)观察组不同血液成分输血的不良反应发生率显著低于对照组(P<0.05)。(3)两组不同年龄和性别输血不良反应发生率对比差异无统计学意义(P>0.05)。(4)观察组共检出20例RhD正定型及不规则抗体阳性患者,其中抗-M型5例,抗-D型3例,抗-E型2例,抗-C型2例,抗-P型2例,抗-LEa型1例,抗-LEb型1例,抗-JKa型1例,抗-N型1例,抗-H型1例,非特异性抗体1例。结论:RhD正定型及不规则抗体筛查能够显著降低输血不良反应发生率,有助于提高配血的准确性,提高输血治疗的安全性。     

Deconjugation of glucuronides catalysed by UDPglucuronyltransferase

Evidence was found for UDPglucuronyltransferase-catalysed deconjugation of p-nitrophenol-, 4-methylumbelliferone- and phenolphthalein-glucuronides. The evidence is based on the following observations: 1, deconjugation is UDP-dependent and the reactions show Michaels-Menten kinetics with respect to UDP and glucuronide saturability; 2, UDP-glucuronic acid was identified as reaction product; 3, all studies were done in the presence of a beta-glucuronidase inhibitor; 4, induction profiles, using 3-methylcholanthrene and phenobarbital as inducing agents, were identical for conjugation and deconjugation reactions. Optimal deconjugation rates for p-nitrophenol- and 4-methylumbelliferone-glucuronides were at pH 5.1 and for phenolphthalein-glucuronide at pH 6.5. Only conjugation reactions showed latency; the corresponding deconjugation reactions were not latent. UDPglucuronyltransferase is a group of oligomeric isoenzymes with different molecular masses. The molecular masses of the isoenzyme species catalysing the forward and reverse reactions were determined by radiation-inactivation analysis. The molecular masses of the isoenzyme species mediating the catalyses of deconjugation reactions were significantly smaller than those mediating catalyses of conjugation reactions: 66 +/- 4 kDa vs. 109 +/- 7 kDa for p-nitrophenol; 82 +/- 8 kDa vs. 105 +/- 6 kDa for 4-methylumbelliferone; and 74 +/- 8 kDa vs. 159 +/- 14 kDa for phenolphthalein. This suggests that for catalyses of deconjugation reactions only part of a UDPglucuronyltransferase isoenzyme is needed, whereas for forward reactions the complete isoenzymes are required.     

Thermodynamics of reactions catalyzed by anthranilate synthase

Microcalorimetry and high performance liquid chromatography have been used to conduct a thermodynamic investigation of reactions catalyzed by anthranilate synthase, the enzyme located at the first step in the biosynthetic pathway leading from chorismate to tryptophan. One of the overall biochemical reactions catalyzed by anthranilate synthase is: chorismate(aq) + ammonia(aq) = anthranilate(aq) + pyruvate(aq) + H2O(l). This reaction can be divided into two partial reactions involving the intermediate 2-amino-4-deoxyisochorismate (ADIC): chorismate(aq) + ammonia(aq) = ADIC(aq) + H2O(l) and ADIC(aq) = anthranilate(aq) + pyruvate(aq). The native anthranilate synthase and a mutant form of it that is deficient in ADIC lyase activity but has ADIC synthase activity were used to study the overall ammonia-dependent reaction and the first of the above two partial reactions, respectively. Microcalorimetric measurements were performed on the overall reaction at a temperature of 298.15 K and pH 7.79. Equilibrium measurements were performed on the first partial (ADIC synthase) reaction at temperatures ranging from 288.15 to 302.65 K, and at pH values from 7.76 to 8.08. The results of the equilibrium and calorimetric measurements were analyzed in terms of a chemical equilibrium model that accounts for the multiplicity of ionic states of the reactants and products. These calculations gave thermodynamic quantities at the temperature 298.15 K and an ionic strength of zero for chemical reference reactions involving specific ionic forms. For the reaction: chorismate2-(aq) + NH4+(aq) = anthranilate-(aq) + pyruvate-(aq) + H+(aq) + H2O(l), delta rHmo = -(116.3 +/- 5.4) kJ mol-1. For the reaction: chorismate2-(aq) + NH4+(aq) = ADIC-(aq) + H2O(l), K = (20.3 +/- 4.5) and delta rHmo = (7.5 +/- 0.6) kJ mol-1. Thermodynamic cycle calculations were used to calculate thermodynamic quantities for three additional reactions that are pertinent to this branch point of the chorismate pathway. The quantities obtained in this study permit the calculation of the position of equilibrium of these reactions as a function of temperature, pH, and ionic strength. Values of the apparent equilibrium constants and the standard transformed Gibbs energy changes delta rG'mo under approximately physiological conditions are given.     

Percentage of patients with preventable adverse drug reactions and preventability of adverse drug reactions--a meta-analysis

Background

Numerous observational studies suggest that preventable adverse drug reactions are a significant burden in healthcare, but no meta-analysis using a standardised definition for adverse drug reactions exists. The aim of the study was to estimate the percentage of patients with preventable adverse drug reactions and the preventability of adverse drug reactions in adult outpatients and inpatients.

Methods

Studies were identified through searching Cochrane, CINAHL, EMBASE, IPA, Medline, PsycINFO and Web of Science in September 2010, and by hand searching the reference lists of identified papers. Original peer-reviewed research articles in English that defined adverse drug reactions according to WHO’s or similar definition and assessed preventability were included. Disease or treatment specific studies were excluded. Meta-analysis on the percentage of patients with preventable adverse drug reactions and the preventability of adverse drug reactions was conducted.

Results

Data were analysed from 16 original studies on outpatients with 48797 emergency visits or hospital admissions and from 8 studies involving 24128 inpatients. No studies in primary care were identified. Among adult outpatients, 2.0% (95% confidence interval (CI): 1.2–3.2%) had preventable adverse drug reactions and 52% (95% CI: 42–62%) of adverse drug reactions were preventable. Among inpatients, 1.6% (95% CI: 0.1–51%) had preventable adverse drug reactions and 45% (95% CI: 33–58%) of adverse drug reactions were preventable.

Conclusions

This meta-analysis corroborates that preventable adverse drug reactions are a significant burden to healthcare among adult outpatients. Among both outpatients and inpatients, approximately half of adverse drug reactions are preventable, demonstrating that further evidence on prevention strategies is required. The percentage of patients with preventable adverse drug reactions among inpatients and in primary care is largely unknown and should be investigated in future research.     

Computerized method for study of temporal characteristics of sensorimotor reactions in preschool and first-grade schoolchildren

A computerized technique for estimation of the reaction time of motor responses to visual stimuli was advanced. The testing includes three stages. The following kinds of reactions were studied: simple reactions at the first stage, simple choice between 2 and 4 alternatives at the second stage, and, finally, reactions of the complex choice between 2 and 4 alternatives at the third stage. The authors think that each kind of reactions reflects specific components of child's sensorimotor activity. It is planned to study the rate of ontogenetic development of different links included into the functional system of voluntary sensorimotor reactions (perceptual, motor, decision making and others) using the proposed technique.     

The Henry reaction of (1R)-(1,4:3,6-dianhydro-d-mannitol-2-yl)-1,4:3,6-dianhydro-d-fructose 5,5′-dinitrate. Different reactive features of nitromethane to nitroethane

Henry reactions of a novel higher sugar derivative, (1R)-(1,4:3,6-dianhydro-d-mannitol-2-yl)-1,4:3,6-dianhydro-d-fructose 5,5′-dinitrate (Alternate nomenclature: (1R)-(isomannid-2-yl)-1,4:3,6-dianhydro-d-fructose 5,5′-dinitrate), with nitromethane and nitroethane were studied. The kinetic and thermodynamic reactions with nitromethane under different conditions were carried out to afford (2S)- and (2R)-β-nitroalcohols, respectively. But when using nitroethane the reaction gave a (2S)-β-nitroalcohol with an inverted configuration at vicinal carbon C-1. Two stereogenic centers were generated, and one was altered in the reaction.     

Genetics of resistance to two strains of soybean mosaic virus in differential soybean genotypes

There are seven pathotypes of soybean mosaic virus (SMV) representing seven strain groups (G1-G7) in the United States. Soybean genotypes [Glycine max (L.) Merr.] may exhibit resistant (R), susceptible (S), or necrotic (N) reactions upon interacting with different SMV strains. This research was conducted to investigate whether reactions to two SMV strains are controlled by the same gene or by separate genes. Two SMV-resistant soybean lines, LR1 and LR2, were crossed with the susceptible cultivar Lee 68. LR1 contains a resistance gene Rsv1-s and is resistant to strains G1-G4 and G7. LR2 contains the Rsv4 gene and is resistant to strains G1-G7. Two hundred F(2:3) lines from LR1 x Lee 68 and 262 F(2:3) lines from LR2 x Lee 68 were screened for SMV reaction. Seeds from each F2 plant were randomly divided into two subsamples. A minimum of 20 seeds from each subsample were planted in the greenhouse and plants were inoculated with either G1 or G7. G1 is the least virulent, whereas G7 is the most virulent strain of SMV. The results showed that all the F(2:3) lines from both crosses exhibited the same reaction to G1 and G7. No recombinants were found in all the progenies for reactions to G1 and G7 in either cross. The results indicate that reactions to both G1 and G7 are controlled by either the same gene or very closely linked genes. This research finding is valuable for studying the resistance mechanism and interactions of soybean genotypes and SMV strains and for breeding SMV resistance to multiple strains.     

Exchange reactions catalyzed by methioninase from Pseudomonas putida. Isolation and characterization of the exchange products.

Gel-electrophoretically homogeneous methioninase [L-methionine methanethiol-lyase (deaminating), EC 4.4.1.11] of Pseudomonas putida, which catalyzes alpha, beta- and alpha, gamma-eliminations from S-substituted amino acids, could also catalyze a variety of beta- and gamma-exchange reactions, according to the following equations: RSCH2CH(NH2)COOH+R'SH in equilibrium R'SCH2CH(NH2)COOH+RSH (beta-exchange) and RSCH2CH2CH(NH2)COOH+R'SH in equilibrium R'SCH2CH2CH(NH2)COOH+RSH (gamma-exchange), where R'SH represents an exogeneously added alkanethiol or a substituted thiol. Related amino acids not available for elimination reactions appeared to be inert as substrates for exchange. The maximum activity for the exchange reactions was observed at pH 8.5 in potassium pyrophosphate buffer. The activity increased linearly with the increase in protein concentration from zero to 3.0 mug per ml, and with incubation time up to at least 15 min at 30 degrees. Some of the exchange reaction products were purified by a combination of paper and ion exchange chromatographies, and charcoal treatment: their structures were confirmed by physicochemical methods including elemental analysis and proton magnetic resonance, infrared, and mass spectrometries.     

阿片类药物滴定法治疗癌痛的疗效及不良反应分析

目的:探讨阿片类药物滴定法治疗癌痛的疗效及不良反应分析,为临床治疗提供依据。方法:采用回顾性分析选择2012年1月~2015年12月我院收治的肿瘤患者共110例,采用数字评定量表(NRS)和面部表情疼痛分级量表(FRS)进行疼痛评价,采用滴定法从小剂量开始给药,并记录患者的疼痛状况和不良反应发生状况。结果:患者总用药时间为28~170 d,平均用药时间(45.7±19.4)d,中位时间为48d。阿片类药物使用剂量(换算成吗啡剂量计算)40~500 mg,中位剂量74 mg。110例患者中有101例(91.82%)达到中度以上缓解。发生不良反应63(57.27%)例,消化道副反应为最常见的不良反应,主要有便秘48例(43.64%)例和恶心呕吐25例(22.73%)、其次依次为嗜睡15例(13.64%)、头晕9例(8.18%)、排尿困难5例(4.55%)、皮肤瘙痒3例(2.73%)和呼吸抑制2例(1.82%)。结论:阿片类药物能够有效缓解癌症患者的中重度癌痛,其主要不良反应是便秘和恶心呕吐。应合理、安全的使用阿片类药物,从小剂量开始,规范剂量滴定。     

Characterization of the half and overall reactions catalyzed by L-lysine:2-oxoglutarate 6-aminotransferase

Significant differences were found in the reaction rate, and the substrate and reaction specificities between the half reactions and the overall reactions catalyzed by L-lysine: 2-oxoglutarate 6-aminotransferase. The half reactions between an amino donor and the enzyme-bound pyridoxal 5'-phosphate, and also between an amino acceptor and the bound pyridoxamine 5'-phosphate followed first order reaction kinetics. The extrapolated first order rate constants and dissociation constants of the substrates were determined for the half reactions: lysine, 0.87 min-1 and 5.5 mM; glutamate, 1.1 min-1 and 10.5 mM; alanine, 0.66 min-1 and 6.6 mM; 6-aminohexanoate, 0.43 min-1 and 13.3 mM; and 2-oxoglutarate, 0.33 min-1 and 2.5 mM. As compared with the values reported for the overall reactions [Soda, K., Misono, H., & Yamamoto, T. (1968) Biochemistry 7, 4102-4109], the reactivity of the inherent substrates was lower by over 4 orders in the half reaction than that in the overall reaction, and the reactivity of alanine with the bound pyridoxal 5'-phosphate was reduced to 10% of that in the overall reaction. The substrate specificity in the half reaction was much lower than that in the overall reaction, which was re-examined in a reaction system containing the same concentration of the enzyme as that for the half reactions. Lysine 6-aminotransferase catalyzes the transfer of only the terminal amino group of lysine to 2-oxoglutarate in the overall reaction. However, in the half reaction, the 2-amino group as well as the terminal one was transferred to the bound pyridoxal 5'-phosphate. The ratio of reactivity of the 2-amino group to that of the 6-amino group was considerably influenced by the pH of the reaction mixture.(ABSTRACT TRUNCATED AT 250 WORDS)     

Physical fitness and thermoregulatory reactions in a cold environment in men

The relationship between the physical fitness level (maximal O2 consumption, VO2max) and thermoregulatory reactions was studied in 17 adult males submitted to an acute cold exposure. Standard cold tests were performed in nude subjects, lying for 2 h in a climatic chamber at three ambient air temperatures (10, 5, and 1 degrees C). The level of physical fitness conditioned the intensity of thermoregulatory reactions to cold. For all subjects, there was a direct relationship between physical fitness and 1) metabolic heat production, 2) level of mean skin temperature (Tsk), 3) level of skin conductance, and 4) level of Tsk at the onset of shivering. The predominance of thermogenic or insulative reactions depended on the intensity of the cold stress: insulative reactions were preferential at 10 degrees C, or even at 5 degrees C, whereas colder ambient temperature (1 degree C) triggered metabolic heat production abilities, which were closely related to the subject's physical fitness level. Fit subjects have more efficient thermoregulatory abilities against cold stress than unfit subjects, certainly because of an improved sensitivity of the thermoregulatory system.     

激素替代周期子宫内膜微创术治疗卵巢早衰的疗效分析

目的:探讨激素替代周期子宫内膜微创术治疗卵巢早衰患者的临床疗效及安全性。方法:选择2013年12月~2015年12月于我院进行治疗的卵巢早衰患者68例,随机分为实验组与对照组,每组34例,实验组患者采用激素替代周期子宫内膜微创术进行治疗,对照组患者服用中药抗衰复巢汤。比较治疗前后两组患者血清卵泡刺激素(FSH)、促黄体生成素(LH)及雌二醇(E2)水平,同时对两组患者的不良反应情况进行统计,治疗结束后比较两组患者的临床疗效。结果:与治疗前相比,两组患者血清FSH、LH水平均降低,E2水平均升高;治疗结束后,与对照组相比,实验组患者血清FSH、LH水平较低,E2水平较高(P0.05),不良反应发生率较低(P0.05),临床总有效率较高(P0.05)。结论:应用激素替代周期子宫内膜微创术可以减少卵巢早衰患者在治疗后的不良反应,提高临床疗效。     

Drug metabolism in the newborn

The duration and intensity of drug action depend not only on the dose of the drug but also on the rates at which drugs are transformed to products that can be excreted readily by the kidney. Two general categories of drug metabolism occur in the liver: phase 1 reactions (oxidations-reductions and hydrolyses) and phase 2 reactions (synthetic conjugations). Phase 1 reactions produce functional groups that can participate in phase 2 reactions. Phase 1 reactions are almost nonexistent in the fetuses of laboratory animals; however, many appear in primates during the first trimester of gestation. Phase 2 reactions are deficient prenatally in both rodents and primates. Parturition triggers a surge of both phase 1 and phase 2 reactions. The lack of uniformity of the development of phase 1 oxidative reactions during the early neonatal period reflects the multiplicity of cytochrome P-450 hemoproteins, the terminal oxidases responsible for most hepatic oxidative biotransformations. The rate of recovery of chemically induced losses of cytochrome P-450 systems is age dependent.     

Studies with radioactive sugars : Part IV. The Methanolysis of D-fructose and L-sorbose

Methanolysis of radioactively labelled D-fructose gives, finally, the α-pyranoside, β-pyranoside, α-furanoside and β-furanoside in the ratios 3:46:25:26. The corresponding ratios for the L-sorbosides are 92:1:5:2. As with the aldoses, these ketoses mainly give furanosides in kinetically controlled reactions; the pyranosides are then formed as thermodynamic products. A primary objective of the work was to examine the role played in the reactions by the acyclic dimethyl acetals; with neither sugar was any such product detected, and it is estimated that their concentrations were never in excess of 0.05% in the reaction components.