Polyacrylamide Gel Separation and Molecular Weight Determination of the Components of Cucumber Mosaic Virus RNA

The six principal components of cucumber mosaic virus RNA were eluted from polyacrylamide gels. After reaction with formaldehyde, their molecular weights were determined by means of sedimentation velocity ultracentrifugation. The molecular weights found were 0.91 million Daltons (mixture of components C₂ and C₁); 0.68 million Daltons (component B); 0.33 million Daltons (component A); 0.11 million Daltons (component 0); and 0.01 million Daltons (component 00). Individual molecular weights of components C₂ and C₁ (determined by polyacrylamide electrophoresis) were 1.01 million and 0.89 million Daltons respectively.     

The interaction of bovine factor V and factor V-derived peptides with phospholipid vesicles

The binding of bovine Factor V, isolated Factor Va, and isolated activation intermediates to single bilayer phospholipid vesicles was studied by light scattering. The vesicles composed of 25% phosphatidylserine and 75% phosphatidylcholine had a mean radius of approximately 163 A as determined by quasi-elastic light scattering. When these vesicles were saturated with Factor V, the radii increased by approximately 120 A in both 0.15 and 1 M NaCl. At saturation, about 35 molecules of Factor V and 141 molecules of Factor Va were bound to each vesicle. Studies of the binding of Factor V and Factor Va at various ionic strengths showed little change in either Kd or n, suggesting that the binding is not electrostatic. The dissociation constants (Kd) and the lipid to protein ratios at saturation, moles/mol (n), obtained by relative light scattering intensities were: Factor V (Kd = 4.3 X 10(-8) M, n = 214); isolated Factor Va (Kd = 1.7 X 10(-7) M, n = 57); component B, Mr = 205,000 (Kd = 1.8 X 10(-7) M, n = 140); component C, Mr = 150,000 (Kd = 7.0 X 10(-7) M, n = 136); component D, Mr = 94,000 (no binding could be demonstrated); component E, Mr = 74,000 (Kd = 3.8 X 10(-7) M, n = 42). The results presented here indicate that the lower Kd exhibited by Factor V compared to Factor Va (components D and E) is primarily due to the interaction present within the component C portion of the molecule which is destroyed when component C is further cleaved to give component D. The interactions responsible for the binding of Factor Va are expressed in component E as well as in its precursor peptide component B. Dissociation of components D and E by the addition of EDTA indicate that component E alone is responsible for the interaction of bovine Factor Va with phospholipid.     

Identifiying human MHC supertypes using bioinformatic methods

Classification of MHC molecules into supertypes in terms of peptide-binding specificities is an important issue, with direct implications for the development of epitope-based vaccines with wide population coverage. In view of extremely high MHC polymorphism (948 class I and 633 class II HLA alleles) the experimental solution of this task is presently impossible. In this study, we describe a bioinformatics strategy for classifying MHC molecules into supertypes using information drawn solely from three-dimensional protein structure. Two chemometric techniques-hierarchical clustering and principal component analysis-were used independently on a set of 783 HLA class I molecules to identify supertypes based on structural similarities and molecular interaction fields calculated for the peptide binding site. Eight supertypes were defined: A2, A3, A24, B7, B27, B44, C1, and C4. The two techniques gave 77% consensus, i.e., 605 HLA class I alleles were classified in the same supertype by both methods. The proposed strategy allowed "supertype fingerprints" to be identified. Thus, the A2 supertype fingerprint is Tyr(9)/Phe(9), Arg(97), and His(114) or Tyr(116); the A3-Tyr(9)/Phe(9)/Ser(9), Ile(97)/Met(97) and Glu(114) or Asp(116); the A24-Ser(9) and Met(97); the B7-Asn(63) and Leu(81); the B27-Glu(63) and Leu(81); for B44-Ala(81); the C1-Ser(77); and the C4-Asn(77).     

Characterization of virulence factors and phylogenetic group determination of <Emphasis Type="Italic">Escherichia coli</Emphasis> isolated from diarrheic and non-diarrheic calves from Brazil

This study aimed to detect virulence factors, pathovars, and phylogenetic groups of Escherichia coli strains obtained from feces of calves with and without diarrhea up to 70 days old and to determine the association between occurrence of diarrhea, phylogenetic groups, and pathovars. Phylo-typing analysis of the 336 E. coli strains isolated from calves with Clermont method showed that 21 (6.25 %) belong to phylogroup A, 228 (67.85 %) to phylogroup B1, 2 (0.6 %) to phylogroup B2, 5 (1.49 %) to phylogroup C, 57 (16.96 %) to phylogroup E, and 3 (0.9 %) to phylogroup F. Phylogroup D was not identified and 20 strains (5.95 %) were assigned as “unknown.” The distribution of phylogenetic groups among pathovars showed that NTEC belong to phylogroups B1 (17) and C (4); EPEC to phylogroups B1 (6) and E (8); STEC to phylogroups A (5), B1 (56), B2 (2), C (1), and E (15); EHEC to phylogroups B1 (95) and E (5); and ETEC to phylogroups A (3), B1 (7), and E (10). The EAST-1 strains were phylogroups A (13), B1 (47), E (19), and F (3); E. coli strains of “unknown” phylogroups belonged to pathovars EPEC (1), EHEC (2), STEC (7), and EAST-1 strains (6). ETEC was associated with diarrhea (P = 0.002). Our study did not find association between the phylogenetic background and occurrence of diarrhea (P = 0.164) but did find some relationship in phylogenetic group and pathovar. The study showed that EHEC and STEC are classified as phylogroup B1, EAST-1 phylogroup A, ETEC, and EPEC phylogroup E.     

Prostaglandin and thromboxane production by rat decidual microsomes

The preparation of a microsomal fraction from the decidual tissue of pregnant rat uteri is described. Incubation of such microsomes with a mixture of radiolabelled and cold arachidonic acid (51 micrometer) plus cofactors resulted in a 30% substrate conversion. Products were resolved into four peaks (A, B, C and D) by thin-layer chromatography. Combined gas-liquid chromatography-mass spectrometry and further thin-layer chromatography identified the products as PGF2 alpha (A); thromboxane B2 (B); a mixture of 6-OXO PGF1 alpha and PGE2 (C); PGD2 and PGE2 (D). PGE2 was the major product.     

Characterisation of Pellicles Formed by Acinetobacter baumannii at the Air-Liquid Interface

The clinical importance of Acinetobacter baumannii is partly due to its natural ability to survive in the hospital environment. This persistence may be explained by its capacity to form biofilms and, interestingly, A. baumannii can form pellicles at the air-liquid interface more readily than other less pathogenic Acinetobacter species. Pellicles from twenty-six strains were morphologically classified into three groups: I) egg-shaped (27%); II) ball-shaped (50%); and III) irregular pellicles (23%). One strain representative of each group was further analysed by Brewster’s Angle Microscopy to follow pellicle development, demonstrating that their formation did not require anchoring to a solid surface. Total carbohydrate analysis of the matrix showed three main components: Glucose, GlcNAc and Kdo. Dispersin B, an enzyme that hydrolyzes poly-N-acetylglucosamine (PNAG) polysaccharide, inhibited A. baumannii pellicle formation, suggesting that this exopolysaccharide contributes to pellicle formation. Also associated with the pellicle matrix were three subunits of pili assembled by chaperon-usher systems: the major CsuA/B, A1S_1510 (presented 45% of identity with the main pilin F17-A from enterotoxigenic Escherichia coli pili) and A1S_2091. The presence of both PNAG polysaccharide and pili systems in matrix of pellicles might contribute to the virulence of this emerging pathogen.     

Progesterone binding components of chick oviduct. X. Purification by affinity chromatography.

Cytoplasmic progesterone receptors of chick oviduct have been purified in 8% yield by steroid affinity and ion exchange chromatography. The affinity resin, deoxycorticosterone-bovine serum albumin-Sepharose, binds progesterone receptors with high affinity (KD equals 8 times 10-minus 10 M) and its use resulted in a greater than 2000-fold purification over the starting material in a single step. DEAE-Sephadex A-50 chromatography was then used to achieve final purification. NA dodecyl-SO4 gel electrophoresis and DEAE-cellulose chromatography showed that the purified receptors contained both of the previously described 4 S progesterone binding components in near equal amounts. Na dodocyl-SO4 gel electrophoresis also showed that these components consisted of single polypeptide chains with molecular weights of 110, 000 (A component) and 117, 000 (B component). There was no evidence for subunits of lower molecular weight. The purified materials have identical hormone-binding kinetics and steroid specificity to crude cytosol receptors. The isolated receptors retain the three biologically important properties exhibited by progesterone binding components present in cruder preparations: they bind specifically to (a) nuclei (KD equals 1.1 times 10-minus 9 M, 10, 000 sites per nucleus); (b) chromatin (KD equals 3 times 10-minus 9 M, 2000 sites per pg of DNA-);and (C) DNA.     

七种秋石斛鲜花挥发性成分差异性分析

为查明秋石斛不同品种关键赋香成分,利用固相微萃取(SPME)方法结合GC-MS技术,测定了秋石斛5个具香气的品种,即绿天使(Dendrobium Hand Green)、日出2号(Dendrobium Burana Sunrise No.2)、白花607(Dendrobium K.B.White 607)、紫背256(Dendrobium Blue Sapphine 256)、魅力(Dendrobium Burana Charming)以及2个不具香气的品种,即红牛(Dendrobium Red Bull)、三亚阳光(Dendrobium Sunya Sunshine)盛花期的花朵挥发性成分及其相对含量。结果表明:共鉴定出45种挥发性化合物,其中萜烯类34种、芳香族化合物8种、酯类3种,5种具香气的秋石斛花朵所含挥发性成分绝大部分都是萜烯类,萜烯类对秋石斛的花香起着重要的作用。通过比较发现,5种具香气秋石斛的主要赋香成分为3-蒈烯、芳樟醇、α-可巴烯和α-法尼烯,不同品种挥发性成分的组成和含量明显不同。绿天使和日出2号的主要香气成分是3-蒈烯,相对含量分别为59.343%和77.775%,但日出2号中的释放率约为绿天使的3倍;白花607主要香气成分为3-蒈烯(29.170%)、α-可巴烯(17.660%)、芳樟醇(10.990%);紫背256中α-法尼烯相对含量最高(42.310%);魅力中主要香气成分是α-可巴烯(33.648%),邻苯二甲酸二异丁酯(13.866%)为其次。2个不具香气品种中鉴定出化合物较少,主要挥发性成分释放率较小;红牛主要挥发性成分是胡莫柳酯(28.118%),三亚阳光是异丁子香酚(27.529%)。这些主要挥发性成分对不同品种秋石斛花的特有香味起决定性作用,且大部分已被广泛应用于香精香料,医药,日化等产品中。该研究结果为香型秋石斛产品开发及品种的培育提供了参考。     

Multicenter study on the immunogenicity and safety of two recombinant vaccines against hepatitis B

The immunogenicity and safety of a new recombinant hepatitis B vaccine from the Instituto Butantan (Butang) were evaluated in a multicenter, double-blind, prospective equivalence study in three centers in Brazil. Engerix B was the standard vaccine. A total of 3937 subjects were recruited and 2754 (70%) met all protocol criteria at the end of the study. All the subjects were considered healthy and denied having received hepatitis B vaccine before the study. Study subjects who adhered to the protocol were newborn infants (566), children 1 to 10 years old (484), adolescents from 11 to 19 years (740), adults from 20 to 30 years (568), and adults from 31 to 40 years (396). Vaccine was administered in three doses on the schedule 0, 1, and 6 months (newborn infants, adolescents, and adults) or 0, 1, and 7 months (children). Vaccine dose was intramuscular 10 microg (infants, children, and adolescents) or 20 microg (adults). Percent seroprotection (assumed when anti-HBs titers were > 10 mIU/ml) and geometric mean titer (mIU/ml) were: newborn infants, 93.7% and 351.1 (Butang) and 97.5% and 1530.6 (Engerix B); children, 100% and 3600.0 (Butang) and 97.7% and 2753.1 (Engerix B); adolescents, 95.1% and 746.3 (Butang) and 96% and 1284.3 (Engerix B); adults 20-30 years old, 91.8% and 453.5 (Butang) and 95.5% and 1369.0 (Engerix B); and adults 31-40 years old, 79.8% and 122.7 (Butang) and 92.4% and 686.2 (Engerix B). There were no severe adverse events following either vaccine. The study concluded that Butang was equivalent to Engerix B in children, and less immunogenic but acceptable for use in newborn infants, adolescents, and young adults.     

Synthesis and characteristics of proteins in inner mitochondrial membranes of the myocardium of rats with disseminated necrotic heart diseases]

Two fractions of the inner membranes of the mitochondria were isolated from rat myocardium: complex-the inner membranes-matrix (fraction A); the aggregates of the inner membranes deproved of the matrix (fraction B). Both fractions of the membranes effectuated the incorporation of the radioactive amino acids with the same activity. With the aid of gel electrophoresis the amount of the protein components of A and B fractions was found to bary from 20 to 30. The mol wts were from 10000 to 200000. Disseminated myocardial necrosis produced by novodrine injection based on the ischemic state of the heart led in two days to a considerable decrease in the protein synthesizing activity of fractions A and B. The protein profiles and the mol wt of the membrane protein components displayed no marked changes.     

A study of the incidence of different fluorescent Pseudomonas species and biovars in the microflora of fresh and spoiled meat and fish, raw milk, cheese, soil and water.

Of 182 various foodstuffs and environmental samples examined, 86% had microflora containing fluorescent Pseudomonas in differing proportions. A computer-aided technique was used to identify most of the 445 fluorescent strains. Pseudomonas fluorescens biovar V-1 was most frequently isolated (24%); it either predominated or was present in all types of samples. Other strains, belonging to the other subgroups of biovar V (V-2, V-4, V-5, V-6 and V-7), together represented 14.3%. We also identified Ps. fluorescens biovars I-1 and I-2 (13.9%), II-1 and II-3 (3.6%), III-1 and III-2 (8.7%), IV-2 (0.7%); Ps. putida A and B (11%); Ps. lundensis (10.3%); group B3 (2%) and Ps. aeruginosa (0.7%). Unidentified strains accounted for 10.6% of the flora, many resembling Ps. fluorescens biovar V. Although the presence of Ps. fluorescens V-1 was often marked, other taxa predominated or were present in large quantities in some particular samples, such as Ps. fluorescens I-1 in raw milk and cheese, Ps. lundensis in spoiled meat and Ps. fluorescens III-1 in spoiled fish. Pseudomonas putida A and B were evident in environmental rather than in food samples.     

Chemical and genetic diversity of Ligularia vellerea in Yunnan, China

Intra-specific diversity in Liularia vellerea growing in the northwestern to central Yunnan province of China was studied by chemical and genetic approaches. Samples collected in the Jianchuan, Lijiang, and Zhongdian areas contained 6,15-dioxygenated furanoeremophilanes as their major components (type A); whereas samples from the Luguhu area accumulated 1,6-dioxygenated furanoeremophilanes (type B); a sample from near Kunming, however, contained 6,15-dioxygenated eremophilanolides (type C). 11 beta H- and 11 alpha H-6 beta-angeloyloxy-15-carboxyeremophil-7-en-12,8-olides (eremofarfugins D and E) were also isolated and their structures were determined. A correlation between the composition and the DNA sequence was observed in the ITSs.     

A study of the incidence of different fluorescent Pseudomonas species and biovars in the microflora of fresh and spoiled meat and fish, raw milk, cheese, soil and water

M. GENNARI AND F. DRAGOTTO. 1992. Of 182 various foodstuffs and environmental samples examined, 86% had microflora containing fluorescent Pseudomonas in differing proportions. A computer-aided technique was used to identify most of the 445 fluorescent strains. Pseudomonas fluorescens biovar V-1 was most frequently isolated (24%); it either predominated or was present in all types of samples. Other strains, belonging to the other subgroups of biovar V (V-2, V-4, V-5, V-6 and V-7), together represented 14.3%. We also identified Ps. fluorescens biovars I-1 and I-2 (13.9%), II-1 and II-3 (3.6%), III-1 and III-2 (8.7%), IV-2 (0.7%); Ps. putida A and B (11%); Ps. lundensis (10.3%); group B3 (2%) and Ps. aeruginosa (0.7%). Unidentified strains accounted for 10.6% of the flora, many resembling Ps. fluorescens biovar V. Although the presence of Ps. fluorescens V-1 was often marked, other taxa predominated or were present in large quantities in some particular samples, such as Ps. fluorescens I-1 in raw milk and cheese, Ps. lundensis in spoiled meat and Ps. fluorescens III-1 in spoiled fish. Pseudomonas putida A and B were evident in environmental rather than in food samples.     

Variability in essential oil composition of Piper dilatatum L.C. Rich

Twelve samples of air-dried aerial parts of Piper dilatatum L. C. Rich yielded essential oils and their volatile constituents were analyzed by GC and GC–MS. Sesquiterpenes, both hydrocarbons and oxygenated, were the most highly represented classes, the former ranging from 31.5% to 87.7% and the latter varying from 1.8% to 49.4%. Using hierarchical cluster analysis, the oils were divided into seven groups, whose main constituents were: (E)-caryophyllene, α-cadinol and germacrene D (group A); spathulenol, bicyclogermacrene and (Z)-β-ocimene, (group B); spathulenol, germacrene D and (E)-nerolidol, (group C); germacrene D, limonene, α-phellandrene and bicyclogermacrene (group D); β-elemene, germacrene D and β-pinene (group E); curzerene, p-cymene and α-eudesmol (group F); and (Z)-α-bisabolene, curzerene and germacrene D (group G). We have seen that Piper oils from the Amazon present as major constituents terpenoids and phenylpropanoids, always with the predominance of one over another. The essential oils of P. dilatatum presented in this paper, containing only mono- and sesquiterpenes as its major components, is further chemotaxonomic evidence of this dichotomy in the Piper genus.     

Physiological and biochemical characteristics and capacity for polyhydroxyalkanoates synthesis in a glucose-utilizing strain of hydrogen-oxidizing bacteria, Ralstonia eutropha B8562

The physiological, biochemical, genetic, and cultural characteristics of the glucose-utilizing mutant strain Ralstonia eutropha B8562 were investigated in comparison with the parent strain R. eutropha B5786. The morphological, cultural, and biochemical characteristics of strain R. eutropha B8562 were similar to those of strain R. eutropha B5786. Genetic analysis revealed differences between the 16S rRNA gene sequences of these strains. The growth characteristics of the mutant using glucose as the sole carbon and energy source were comparable with those of the parent strain grown on fructose. Strain B8562 was characterized by high yields of polyhydroxyalkanoate (PHA) from different carbon sources (CO2, fructose, and glucose). In batch culture with glucose under nitrogen limitation, PHA accumulation reached 90% of dry weight. In PHA, beta-hydroxybutyrate was predominant (over 99 mol %); beta-hydroxyvalerate (0.25-0.72 mol %) and beta-hydroxyhexanoate (0.008-1.5 mol %) were present as minor components. The strain has prospects as a PHA producer on glucose-containing media.     

Influence of instructions in multi-discrimination experiments on event related potentials

The purpose of the experiment was to study the effects of psychological factors on slow brain potentials in relation to information processing and strategy establishment. Subjects were subjected to paired stimuli: A) two identical tone bursts (50 ms, 5000 Hz); B) two different stimuli the second (unconditioned) was a low pitched tone burst (50 ms, 500 Hz); C) only the warning stimulus was delivered to the subjects. In a first experiment, subjects (N = 10) were asked to detect and signal by a motor act the low pitched click (B); in a second experiment, subjects (N = 8) were to detect and signal in the same way the unconditioned tone burst omission (C). Results showed that the auditory event-related potentials (ERP) obtained in the two experiments presented two components: a negative wave (N150) followed by a positive one (P270). Solely, the late positive component differed in topography during the two situations. A fronto-central Contingent Negative Variation (CNV) appeared in all the conditions for the two experiments while a Post Imperative Negative Variation was often obvious in the first experiment.     

HLA class I polymorphism in the Albanian population

The HLA class I polymorphism was studied in a sample of the Albanian population. Ninety-three unrelated healthy Albanians were typed for HLA-A, -B and -Cw antigens by standard microlyphocytotoxicity test. The antigens with the highest frequencies were: HLA-A2 (34.4%), A3 (14.5%) and A1 (12.4%); B51 (19.3%), B35 (12.4%) and B18 (10.2%); Cw4 (16.2%), Cw7 (16.2%) and Cw6 (10.8%). The HLA haplotypes with high frequency in Albanians included A2-B51 (4.3%), A2-B18 (2.4%), A2-B35 (2.4%), Cw4-B35 (7.6%), and Cw7-B18 (6.5%), which are not significantly different from the other neighboring populations. Low frequency of HLA-A1-B8 haplotype (1.1%) is noted in the Albanian population. The frequency of HLA-B27 antigen (1.1%) is one of the lowest frequencies observed in Caucasians. Such results are important in studies of HLA-A1-B8, HLA-B27 and disease associations. These findings should be also useful in understanding the origin of Albanians, representing a base for future studies about HLA polymorphism in the Albanian population.     

Isolation of O-demethylase, an ether-cleaving enzyme system of the homoacetogenic strain MC

The O-demethylase of the methylotrophic homoacetogenic bacterium strain MC was purified to apparent homogeneity. The enzyme system consisted of four different components that were designated A, B, C, and D according to their elution sequence from the anionic-exchange chromatography column. All four components were essentially required for catalysis of the transfer of the methyl group from phenyl methyl ethers to tetrahydrofolate. According to gel filtration and SDS-PAGE, components A and B were monomers with apparent molecular masses of approximately 26 kDa (subunit 25 kDa) and 36 (subunit 41 kDa), respectively; component C appeared to be a trimeric protein (195 kDa, subunit 67 kDa); and component D was probably a dimer (64 kDa, subunit 30 kDa). Component A contained one corrinoid per monomer. In crude extracts, component D appeared to be the rate-limiting protein for the complete methyl transfer reaction. Additional requirements for the reaction were ATP and low-potential reducing equivalents supplied by either titanium(III) citrate or H₂ plus hydrogenase purified from strain MC. Received: 5 February 1997 / Accepted: 17 April 1997     

连续肾脏替代疗法治疗重症急性胰腺炎时机的探讨

目的:探讨连续肾脏替代疗法(CRRT)治疗重症急性胰腺炎的最佳时机。方法:选取我院收治的30例重症急性胰腺炎(SAP)患者为研究对象,按发病后行CRRT的时间分将患者随机为A、B两组,A组发病后72小时内治疗,B组发病后72小时后治疗,分析和比较两组治疗后的临床转归及生命体征变化、APACHEⅡ评分变化急性生理与慢性健康状况、住院费用、平均住院时间。结果:经CRRT治疗后,A组死亡率(14.3%)低于B组(43.7%),差异有统计学意义(P0.05);A、B两组治疗后体温、心率、呼吸、平均动脉压平稳,A组优于B组,差异有统计学意义(P0.05);A组的平均住院时间(15.7±8.9)d、住院费用(107000±65000)万元均明显优于B组,差异有统计学意义(P0.05);两组患者治疗后APACHEⅡ评分均明显优于治疗前,治疗后A组APACHEⅡ评分明显优于B组,差异显著有统计学意义(P0.05)。结论:早期行CRRT能明显改善重症急性胰腺炎患者的疗效和预后,最佳治疗时机可能为发病后72小时内。     

Prevalence of otomycosis in malnourished children in Edo State,Nigeria

Out of the total number at 200 suspected cases of otomycoses consisting of 40 malnourished and 160 apparently healthy children examined in this study between the months of July and August in Edo State, 64 Cases (32%) were identified to be of fungal aetiology on the basis of positive culture and careful microscopic exarnination. The state at protein energy malnourishment was deterwined using physicians' comments in their case files. The fungal agents isolated were Aspergillus niger 28 (43.8%); A. fumigatus 4 (25%); Fusarium solari 4 (6.3%); Candida albicans 8 (12.5%); and Hendersonula teruloidea types torn B 5 (6.3%). Of these isolates, A. niger having an solation rate of (43.8%) was found to be the most predominant fungal species associated with otomycosis. This revised version was published online in August 2006 with corrections to the Cover Date.