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1.
In addition to canthaxanthin, seven pigment fractions were isolated from Micrococcus roseus. They were purified by solvent partitioning and by column and thin-layer chromatography. Visible absorption spectra, chromatographic behavior, and partition coefficients of the pigments and derivatives prepared from the pigments were used in characterizing them. Both alpha- and beta-carotene derivatives were present. The structure of one pigment was suggested as phoenicoxanthin (3-hydroxy-4,4'-diketo-beta-carotene). Four other pigments were tentatively characterized as a dihydroxy-3,4-dehydro-alpha-carotene, a dihydroxy-alpha-carotene, a diketo-alpha-carotene, and a polyhydroxy-beta-carotene. Two pigments were isolated in trace amounts and could not be characterized. All the pigments studied were isolated as mixtures of cis-trans isomers and all except the diketo-alpha-carotene were isolated as esters from M. roseus. Quantitation of the pigments showed that canthaxanthin (4,4'-diketo-beta-carotene) represented 85% of the pigment recovered from extracts. Three of the other pigments contributed a significant proportion of the remaining pigments, whereas the other four were present in only small amounts. beta-Carotene derivatives comprised 96% and alpha-carotene derivatives 4% of the pigments recovered from extracts.  相似文献   

2.
Karyotypes of blood lymphocytes were studied in 21 pregnant women. In 8 cases, 46,XY cells were found in the maternal blood and a boy was born in all cases. In 3 cases various chromosome rearrangements were seen. In 6 cases, no 46,XY cells were seen and a girl was born in each case. In 3 cases no 46,XY cell was observed (in 800 cells) and boys were born. In 3 other cases, a 46,XY cell was found and girls were born; all mothers had previously given birth to boys. In 1 case, 2 46,XY cells were observed, and a girl was born; the mother had had an induced abortion in the 3rd month of pregnancy 3 years earlier. It was concluded that the detection of a male fetus seems possible in pregnant women who have no previous male progeny. The persistence of cells from previous pregnancies appears to be a possibility, however.  相似文献   

3.
Isolation of Morphological Mutants of Agrobacterium tumefaciens   总被引:7,自引:7,他引:0       下载免费PDF全文
Morphological mutants were isolated from a wild strain of Agrobacterium tumefaciens at a high frequency by treatment with a nitrosoguanidine. Seventeen of the 20 mutants isolated were temperature-sensitive. At 27 C, the mutant cells were rod-shaped and at 37 C, spherical or branched, whereas the wild-type cells were rod-shaped at both temperatures.  相似文献   

4.
Microgram amounts of proteins applied to polyacrylamide gel electrophoresis were subjected to a fingerprinting procedure using a combined proteolysis-acetylation method with the aid of 14C-labeled acetic anhydride of high specific activity. After staining, gel slices were partially dried and were resoaked in a solution of a protease. After elution and acetylation, the resulting peptides were resolved in fingerprints on cellulose thin-layer chromatography plates and subjected to autoradiography with or without sensitization. Yields, completeness of fingerprinting, and possible artefacts were investigated.  相似文献   

5.
Sphingomyelin was isolated from a strain of Entomophthora coronata, a fungus pathogenic for humans. After hydrolysis, the long chain bases were converted to their dinitrophenyl (N2pH) derivatives and the aldehydes prepared by oxidizing these compounds with periodic acid. The aldehydes were studied by gas chromatography. Twelve different aldehydes were identified, the chain distributiion ranging from C14 to C17. The prominent chains were unsaturated. Straight and branched chains were found. The most abundant parent base which formed 52% of the total aldehyde was a 1,3-dihydroxy-2-aminohexadecene.  相似文献   

6.
We isolated a collection of chemotaxis mutants and characterized them for chemotactic phenotype and genotype. The mutations of most of these mutants mapped in the region between pyrD and thyA. However, the mutation in the gene specifying the chemotactic methyltransferase mapped very close to aroF. From a bank of phages containing Bacillus subtilis DNA we identified two lambda charon4 phages that contained genes specifying chemotactic functions. The inserted DNAs were removed by digestion with restriction endonuclease EcoRI and were found to share a 4.0-kilobase (kb) fragment. One of these DNAs also contained a 7.7-kb fragment, and the other also contained a 10.9-kb fragment. We identified mutants that were complemented by each fragment. The fragments were each ligated into plasmid pFH7 and were incorporated into lysogenic SP beta c2 or a deletion mutant of SP beta c2 in order to form transducing phages. The mutants in the collection containing mutations that mapped in the region between pyrD and thyA were tested for complementation by transducing phages containing the 4.0-kb fragment, the 7.7-kb fragment, the 4.0-kb fragment plus the 7.7-kb fragment, and the 10.9-kb fragment. A total of 24 mutants were complemented by the 4.0-kb fragment, 7 were complemented by the 7.7-kb fragment, 9 were complemented by the 4.0-kb fragment plus the 7.7-kb fragment, 15 were complemented by the 10.9-kb fragment, and 25 were complemented by none of the fragments.  相似文献   

7.
Adult penaeid shrimp were collected from mariculture raceways, holding tanks, and near-shore waters of Galveston Island, Texas. Those with darkly pigmented lesions were chosen for study. When observed by scanning electron microscopy, diseased cuticle shows dense populations of bacteria within a lesion, whereas normal cuticle shows a relatively low number of bacteria. Some lesions exhibited a morphologically homogeneous population of bacteria while others revealed a heterogeneous or mixed infection. Bacteriological analysis of a homogenate of each lesion revealed the presence of a wide variety of organisms which produced extracellular lipases, proteases, and chitinases. Lipolytic and proteolytic organisms were consistently isolated from all 20 lesions examined, while chitinoclastic bacteria were found in all but two lesions. According to the presumptive isolation scheme used, 10 distinct phenotypes of bacteria were differentiated among the isolates from 20 lesions. These phenotypes were classified into four genera: Vibrio, Alteromonas, Spirillum, and Flavobacterium. Groups of 10 shrimp were abraded and inoculated with representative isolates from each of the 10 phenotypes. Four isolates were able to initiate lesion formation. These were two Vibrio species, one Alteromonas species, and one Spirillum species. All of these four pathogens were lipolytic, while only two were chitinoclastic. This evidence suggests that there is not one specific chitinoclastic bacterium which causes brown spot symptoms, but that a variety of bacteria acting alone or in groups may be the causal agents.  相似文献   

8.
Protoplasts released from young hyphae of Trichoderma harzianum contained 0 to 10 nuclei per protoplast, and most (about 80%) contained from 4 to 6 nuclei. Most protoplasts were larger than 3 μm in diameter. Nuclei were isolated from protoplasts of an auxotrophic mutant of T. harzianum and transferred into protoplasts obtained from another auxotroph of the same strain. This intrastrain nuclear transfer gave rise to numerous progeny which were stable, prototrophic, and heterokaryotic. Interstrain transfers in which nuclei from a wild-type prototroph of one strain were transferred into protoplasts from a lysine-deficient auxotroph of a second strain were also done. Heterokaryotic progeny were recovered from these interstrain transfers when the regenerating protoplasts were provided with a low concentration of lysine 48 h after the initial plating. Heterokaryotic progeny contained 11 to 17% of donor-type nuclei. Progeny homokaryotic for donor-type nuclei were obtained as single-spore isolates. These homokaryotic isolates expressed the isozyme pattern and colony morphology phenotype of the nuclear donor. When regenerating protoplasts were provided with lysine 10 days after the initial plating, only a single progeny was obtained. However, single-spore subprogeny of this nuclear transfer were prototrophic and exhibited a wide range of unstable morphological phenotypes.  相似文献   

9.
ABSTRACT. Specificity and sensitivity of gustatory neurones in response to twenty-two amino acids were studied in larvae of Pieris brassicae L. and Pieris rapae L. (Lepidoptera: Pieridae) using electrophysiological methods. Twelve amino acids stimulated a specific amino acid receptor cell in the lateral styloconic sensillum on the maxillary galea of both species, and a further two evoked single unit responses in the same sensillum of P.brassicae only. Histidine, phenylalanine and tryptophane were the weakest stimulants for P.brassicae , but were among the four best stimulants for P.rapae . In both species, eight amino acids were ineffective. Significant differences in stimulatory effectiveness were found between amino acids. Nutritionally essential amino acids were more effective in both species, as in five other lepidopterous species. Similarities with postulated sites for amino acid recognition in the dipteran Boettcherisca peregrina were found.
Concentration-response (C/R) relations were studied for five amino acids. Significant differences were found in saturated response levels. Parameters characterizing C/R relations were estimated using a logistic model. Comparing C/R parameters with phytochemical data on concentrations of free amino acids in a common host plant, Brassica oleracea L., shows that amino acids are effective stimuli at their natural concentrations. The amino acid chemoreceptor seems able to transmit information about concentration differences of amino acids in the plant tissue.  相似文献   

10.
Zhang W  Lu CP 《Proteomics》2007,7(24):4468-4476
Streptococcus suis type 2 (SS2) is a porcine zoonotic pathogen with worldwide distribution, and lacking suitable vaccine and virulent maker were bottleneck to control this infection. An immunoproteomic assay was used to identify antigenic proteins from the total extracellular proteins of the virulent Chinese SS2 strain ZY05719. The convalescent serum of a specific pathogen free (SPF) mini-pig recognized nine protein spots on PVDF membrane. Antigenic proteins on a duplicate gel, as well as those with a similar placement of extracellular proteins from another virulent strain (HA9801) and an avirulent strain (T15) on 2-D gels, were excised and identified by MALDI-TOF-MS. PMF of the protein spots were performed using the MASCOT server. Two proteins were found in all three strains. Comparative proteomic analysis between the two virulent strains and the avirulent strain revealed nine differential proteins, eight of which were successfully identified. Genes for six of the differentially expressed proteins were found in both virulent strains, and of those were present in the avirulent stain.  相似文献   

11.
The observations were performed in autumn in 100 rats at the age of 1 month. The animals were trained in a horizontal treadmill with the speed 40 m/min, beginning with 3 min/day and gradually increasing the time up to 30 min. The control animals were not trained, the test animals were trained either once a day (at 7 a. m., 3 p. m., 11 p. m.), or three times a day and the total loading was equal to a single loading. The animals were weighed daily. Elongation of the bones, increase in their mass and in the body mass were different at training during different time of the day and the effect was not similar in different bones. Certain sexual differences of the training effect were revealed.  相似文献   

12.
The species composition and distribution of ostracods were investigated at two sites with different pollution levels on the eastern coast of Amurskii Bay within the limits of Vladivostok City. A total of 41 species were found. In all, thirty-eight species (28 of them alive) were found at the first site between Krasnyi and Groznyi capes. Another twenty-seven species were found at a depth of 1.5–3 m in the phytal zone with a diversity of microbiotopes. As the bottom became increasingly silty and the depth increased, the number of species decreased. A total of 25 species (only 15 of them alive) were found at the mouth of the Vtoraya Rechka River, which is heavily polluted by municipal and industrial sewage discharge. No valves of ostracods were found in surface sediments on silts at a depth down to 5.5m. At 4 m, only 2 species were found alive on stones overgrown with Saccharina japonica. At 500 m from a sewage discharge site, few ostracod valves were found that seemed to have died recently. At a distance of over 1 km, an ostracod assemblage typical of the silty substrates of Amurskii Bay was found below a 7 m depth (21 species, 12 of them alive).  相似文献   

13.
Studies were carried out on guinea pigs and albino rats, intranasally infected with P. pseudomallei C-141. The cells of bronchovesicular exudate were obtained from animals 1, 4 and 24 hours after infection. Electron microscopy was applied to study the process of interaction of the agent and alveolar macrophages. Bacteria were shown to form a capsule which permitted avoiding phagocytosis, when entering the host respiratory system. Microbes that failed to form a capsule were absorbed by macrophages and enclosed in a phagosome. Then some bacteria were destroyed by the lysosomal enzymes, the other synthesized a capsule, which protected them against the effect of phagolysosome content. There were also such microbes which escaped from a phagosome prior to fusion with lysosomes and parasitized in phagocytic cytoplasma forming a capsule there. By the end of the first 24 hours of observation the intact encapsulated microbe species were found to prevail in the host cells.  相似文献   

14.
During a four-year study period 43 985 patients were seen in the treatment room and 61 806 coded procedures carried out. Thirty per cent of these procedures were not part of usual nursing curricula and required initial supervision and assessment or training (or both). Nearly 15% of the patients seen were making a first visit and did not require referral to a doctor. A further 17% were also making a first visit but were referred to a doctor. The treatment room made an important contribution to the work of the practice, but this would not have been possible if the staff concerned had been attached nurses requiring area health authority authorisation for procedures carried out as opposed to practice nurses for whom procedures were authorised on a personal basis.  相似文献   

15.
目的建立阿霉素大鼠肾病模型,并观察模型的动态变化。方法 26只Wistar雄性大鼠随机分为模型组(13只)和空白组(13只),模型组单次尾静脉注射阿霉素6.2 mg/kg,空白组注射等容积生理盐水。检测连续10周12 h尿蛋白定量、终末血生化指标,光镜、电镜下观察各组大鼠肾脏病理改变。结果模型组12 h尿蛋白定量造模后1周与空白组差异有显著性(P0.01),第5周达到高峰;血总蛋白、白蛋白均低于空白组,甘油三酯、胆固醇、血尿素氮均高于空白组(均P0.05),血肌酐差异无显著性(P=0.64)。肾脏病理改变:第5周为微小病变型,第10周为局灶性节段性肾小球硬化。结论单次尾静脉注射6.2 mg/kg阿霉素,可以成功建立渐进性的大鼠肾病综合征模型。  相似文献   

16.
In order to evaluate fine needle aspirates of thyroid lesions with features intermediate between those of follicular neoplasms and colloid nodules, 38 aspirates in which a definitive diagnosis had not been made were reviewed. On review, ten aspirates were excluded from the "intermediate" category; seven were reclassified as unsatisfactory and one as a cellular colloid nodule. Two papillary carcinomas showed a complex pattern not identified in smears from other lesions; these aspirates were also classified separately for independent evaluation. The remaining 28 aspirates were characterized by syncytial-type tissue fragments with mild nuclear atypia. The association of syncytial-type tissue fragments and orderly sheets and fragments forming a honeycomb pattern in the same aspirate indicated a colloid nodule, though a two-disease process could not be excluded. Of the aspirates containing only syncytial-type tissue fragments, 50% were from adenomas, 25% were from carcinomas, and 25% were from colloid nodules. Criteria to distinguish between the various follicular lesions were not identified in these smears.  相似文献   

17.
目的:研制猪链球菌2型(SS2)全基因组DNA芯片,建立SS2基因表达谱技术平台。方法:利用SS2全基因组序列,挑选出2194条基因,经PCR扩增出2156条基因并将产物纯化,点样制备芯片;将芯片用于表达谱研究,采用实时定量PCR验证表达谱结果,对芯片进行可靠性分析。结果:芯片杂交数据与实时定量PCR验证显示了较高的相关性,二者相关系数r=0.87。结论:研制了一批SS2全基因组DNA芯片,并建立了基于DNA芯片的表达谱技术平台。  相似文献   

18.
Evidence has accumulated that herbicides in the environment present a significant health hazard to the population. Therefore, the levels of heavily used substances such as atrazine and simazine and their metabolites need to be regularly assessed. The objective was to develop a rapid and simple tube ELISA procedure suitable for use in field studies and non-specialized laboratories. The antisera used were polyclonal antibodies raised in sheep against atrazine or simazine amido caproic acid conjugated to bovine serum albumin. The antibodies were first used to construct a two-step competitive ELISA procedure in 96-well microtitre plates. The 96-well format was then adapted to a coated-tube enzyme immunoassay, by immobilization of hapten-gelatine conjugates on polystyrene tubes. This enabled the colour to be read using a basic spectrophotometer. Soil samples were collected from agricultural and non-agricultural sites in Poland. Atrazine and simazine were extracted by liquid extraction from soil and assayed by tube ELISA. In addition, the samples were extracted by solid-phase extraction before analysis by HPLC. The immunoassays and chemical analysis were carried out by different individuals who were unaware of each other's results, which were then compared at the end of the study. Correlation of the two methods was excellent, with R=98.7 and 81.3 for atrazine and simazine, respectively. The immunoassay yielded the same order of results without having to perform solid-phase extraction before analysis. The study has demonstrated that the simple antigen-coated tube assay provides a cost-effective and valuable screening test. Comparison with the more elaborate, heavily labour-intensive HPLC analysis demonstrated that the results obtained by the simpler enzyme-immunoassay tests were within the same order.  相似文献   

19.
Evidence has accumulated that herbicides in the environment present a significant health hazard to the population. Therefore, the levels of heavily used substances such as atrazine and simazine and their metabolites need to be regularly assessed. The objective was to develop a rapid and simple tube ELISA procedure suitable for use in field studies and non-specialized laboratories. The antisera used were polyclonal antibodies raised in sheep against atrazine or simazine amido caproic acid conjugated to bovine serum albumin. The antibodies were first used to construct a two-step competitive ELISA procedure in 96-well microtitre plates. The 96-well format was then adapted to a coated-tube enzyme immunoassay, by immobilization of hapten-gelatine conjugates on polystyrene tubes. This enabled the colour to be read using a basic spectrophotometer. Soil samples were collected from agricultural and non-agricultural sites in Poland. Atrazine and simazine were extracted by liquid extraction from soil and assayed by tube ELISA. In addition, the samples were extracted by solid-phase extraction before analysis by HPLC. The immunoassays and chemical analysis were carried out by different individuals who were unaware of each other's results, which were then compared at the end of the study. Correlation of the two methods was excellent, with R=98.7 and 81.3 for atrazine and simazine, respectively. The immunoassay yielded the same order of results without having to perform solid-phase extraction before analysis. The study has demonstrated that the simple antigen-coated tube assay provides a cost-effective and valuable screening test. Comparison with the more elaborate, heavily labour-intensive HPLC analysis demonstrated that the results obtained by the simpler enzyme-immunoassay tests were within the same order.  相似文献   

20.
cDNA clones for a fifth polypeptide of rat brain calmodulin-dependent protein kinase II were isolated and sequenced. The cDNA sequence encoded a polypeptide, designated delta, consisting of 533 amino acid residues with a molecular weight of 60,080. Comparison of amino acid sequences of this and alpha, beta, beta', and gamma polypeptides of calmodulin-dependent protein kinase II reveals marked homology among them. The mRNAs for delta were expressed in rat brain tissues with different regional specificities. The distribution of alpha, beta/beta', gamma, and delta mRNAs in cerebrum, skeletal muscle, diaphragm, heart, small intestine, uterus, aorta, liver, kidney, lung, and testis were examined by RNA blot hybridization analysis with probes specific for the respective mRNAs. A 3.9-kilobase (kb) RNA species hybridizable with a probe for gamma was found in all the tissues examined, and 4.0-4.2-kb RNA species hybridizable with a probe for delta were found in all the tissues examined except for liver, while a 4.8-kb RNA species hybridizable with a probe for alpha and a 4.2-kb RNA species hybridizable with a probe for beta were present in brain but not in the other tissues. With the alpha probe, however, a 4.1- and 2.6-kb RNA species were both detected in skeletal muscle and diaphragm. With the beta probe, a 4.3-kb RNA in skeletal muscle and diaphragm, 2.9-kb RNA in small intestine, and 4.0-kb RNA in testis were detected. With the delta probe, a 3.5-kb RNA in heart and 1.8-kb RNA in testis were detected. Thus, gamma and delta mRNAs were expressed in various tissues, while alpha and beta/beta' mRNAs were primarily, if not exclusively, expressed in brain.  相似文献   

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