Summary A polyphasic taxonomic study was undertaken to establish the genetic and phenotypic relationships among six actinomycetes that produce the immunosuppressant macrolides FK506, FK520/FK523 and rapamycin. Chemotaxonomic studies reveal that all have Type I cell walls. Gas chromatography (GC) of fatty acid methyl esters revealed patterns consistent for strains ofStreptomyces with 160 and 150anteiso predominating. Principal component analysis of GC data revealed distinct profiles for each culture. Reciprocal DNA homology studies atTm-25 showed the rapamycin-producing strain and one FK506-producing strain to have 38–50% homology with the type strain ofStreptomyces hygroscopicus (ATCC 27438). The remaining strains exhibited 6–17% homology. To further explore the relationships among these strains all were probed for the presence of anO-methyltransferase gene specific to this biosynthetic pathway. Among the strains of interest, onlyStreptomyces hygroscopicus subsp.yakushimaensis, the patent strain for FK520/FK523, failed to hybridize with the probes. 相似文献
Differentiation of embryonic stem cell (ESC)-derived embryoid bodies (EBs) is a heterogeneous process. ESCs can differentiate
in vitro into different cell types including beating cardiomyocytes. The main aim of the present study was to develop an improved
preparation method for scanning electron microscopic study of ESC-derived cardiac bundles and to investigate the fine structural
characteristics of mouse ESCs-derived cardiomyocytes using electron microscopy. The mouse ESCs differentiation was induced
by EBs’ development through hanging drop, suspension and plating stages. Cardiomyocytes appeared in the EBs’ outgrowth as
beating clusters that grew in size and formed thick branching bundles gradually. Cardiac bundles showed cross striation even
when they were observed under an inverted microscope. They showed a positive immunostaining for cardiac troponin I and α-actinin.
Transmission and scanning electron microscopy (TEM & SEM) were used to study the structural characteristics of ESC-derived
cardiomyocytes. Three weeks after plating, differentiated EBs showed a superficial layer of compact fibrous ECM that made
detailed observation of cardiac bundles impossible. We tried several preparation methods to remove unwanted cells and fibers,
and finally we revealed the branching bundles of cardiomyocytes. In TEM study, most cardiomyocytes showed parallel arrays
of myofibrils with a mature sarcomeric organization marked by H-bands, M-lines and numerous T-tubules. Cardiomyocytes were
connected to each other by intercalated discs composed of numerous gap junctions and fascia adherences. 相似文献
Foot-and-mouth disease virus (FMDV) is highly contagious and responsible for huge outbreaks among cloven hoofed animals. The aim of the present study is to evaluate a plasmid DNA immunization system that expresses the FMDV/O/IRN/2007 VP1 gene and compare it with the conventional inactivated vaccine in an animal model. The VP1 gene was sub-cloned into the unique Kpn I and BamH I cloning sites of the pcDNA3.1+ and pEGFP-N1 vectors to construct the VP1 gene cassettes. The transfected BHKT7 cells with sub-cloned pEGFP-N1-VP1 vector expressed GFP-VP1 fusion protein and displayed more green fluorescence spots than the transfected BHKT7 cells with pEGFP-N1 vector, which solely expressed the GFP protein. Six mice groups were respectively immunized by the sub-cloned pcDNA3.1+-VP1 gene cassette as the DNA vaccine, DNA vaccine and PCMV-SPORT-GMCSF vector (as molecular adjuvant) together, conventional vaccine, PBS (as negative control), pcDNA3.1+ vector (as control group) and PCMV-SPORT vector that contained the GMCSF gene (as control group). Significant neutralizing antibody responses were induced in the mice which were immunized using plasmid vectors expressing the VP1 and GMCSF genes together, the DNA vaccine alone and the conventional inactivated vaccine (P<0.05). Co-administration of DNA vaccine and GMCSF gene improved neutralizing antibody response in comparison with administration of the DNA vaccine alone, but this response was the most for the conventional vaccine group. However, induction of humeral immunity response in the conventional vaccine group was more protective than for the DNA vaccine, but T-cell proliferation and IFN-γ concentration were the most in DNA vaccine with the GMCSF gene. Therefore the group that was vaccinated by DNA vaccine with the GMCSF gene, showed protective neutralizing antibody response and the most Th1 cellular immunity. 相似文献
Support vector machines (SVM) and K-nearest neighbors (KNN) are two computational machine learning tools that perform supervised classification. This paper presents a novel application of such supervised analytical tools for microbial community profiling and to distinguish patterning among ecosystems. Amplicon length heterogeneity (ALH) profiles from several hypervariable regions of 16S rRNA gene of eubacterial communities from Idaho agricultural soil samples and from Chesapeake Bay marsh sediments were separately analyzed. The profiles from all available hypervariable regions were concatenated to obtain a combined profile, which was then provided to the SVM and KNN classifiers. Each profile was labeled with information about the location or time of its sampling. We hypothesized that after a learning phase using feature vectors from labeled ALH profiles, both these classifiers would have the capacity to predict the labels of previously unseen samples. The resulting classifiers were able to predict the labels of the Idaho soil samples with high accuracy. The classifiers were less accurate for the classification of the Chesapeake Bay sediments suggesting greater similarity within the Bay's microbial community patterns in the sampled sites. The profiles obtained from the V1+V2 region were more informative than that obtained from any other single region. However, combining them with profiles from the V1 region (with or without the profiles from the V3 region) resulted in the most accurate classification of the samples. The addition of profiles from the V 9 region appeared to confound the classifiers. Our results show that SVM and KNN classifiers can be effectively applied to distinguish between eubacterial community patterns from different ecosystems based only on their ALH profiles. 相似文献
The Collembola fauna of Iran is little known and no comprehensive examination of this group of Hexapoda is available for this region. The only notable work on Collembola was carried out by Cox (1982). Recently, studies on the Collembola fauna have started in several regions. In this paper, publications by different researchers are documented and the species that have been found in different regions of Iran until January 2013 are listed. At present, 112 species, belonging to 18 families and 57 genera are known from Iran. 相似文献
This study was conducted to investigate the effect of pistachio green hull extract (PGHE) on hematological and serum biochemical changes in common carp, Cyprinus carpio. Three hundred common carp (11.65 ± 1.65 g) were fed one of five different dietary treatments (with three replications) containing 0, 0.5, 1.5, 4.5 or 9 g PGHE kg?1diet for ten continuous weeks. Each tank had a 90‐L capacity and water flow rate of about 500 ml min_1.Total phenolic compounds of the different diets differed significantly (P < 0.001) according to the amount of PGHE. At the end of experiment, six fish were removed randomly from each treatment. Blood samples were taken for hematological and serum biochemical analyses at room temperature. Liver tissue samples were processed for histology and stained by H&E. The results indicated that all doses of tested PGHE induced no significant changes in hematocrit, hemoglobin, or erythrocytes, nor alkaline phosphatase, alanine transaminase, lactate dehydrogenase, total protein, albumin, globulin, triglycerides, low‐density lipoprotein, high‐density lipoprotein, glucose or cholesterol in the serum. Leukocytes were higher (P < 0.01) in fish fed a 1.5, 4.5, or 9 g PGHE kg?1 diet when compared to the 0.5 g PGHE kg?1 diet group or the control. Serum aspartate transaminase in treatments containing a 4.5 or 9 g PGHE kg?1 diet was significantly (P < 0.001) higher in comparison with the control. Liver histology showed focal necrosis, cytoplasm degeneration, lateral nuclei and an increase in Kupffer cells following PGHE administrations. The results of this trial indicated that although there were no significant changes in most hematological and biochemical parameters, PGHE could induce some adverse pathological effects on liver tissue. 相似文献
Lut desert is situated in one of the extremely arid climatic zones of Iran and is one of the hottest deserts in our plant with the extreme fluctuation of temperature over a day. The main objective of this study is to characterize the diversity of the culturable actinomycetes and preliminary evaluation of their extracts as antimicrobial components on drug resistant pathogens. Twenty-four soil samples were collected, successively diluted and inoculated into the different culture media to support the growth of most culturable bacteria including actinomycetes. Phenotypic and molecular methods were used for accurate identification of recovered isolates particularly actinomycetes at the genus and species levels. The isolates were also evaluated for their inhibitory activities against drug resistant Acinetobacter baumannii, Enterococcus faecium, Klebsiella pneumoniae and Staphylococcus aureus. A total of 56 isolates recovered from the samples. Based on phenotypic tests, 41 isolates were identified as actinomycetes, amongst them 8 isolates were active against drug resistant pathogens. Our study revealed Lut desert, as one of the hottest deserts in the world, is the habitat to diverse taxa of bacteria particularly actinomycetes which have potential novel antimicrobial components.
Sleep and Biological Rhythms - Narcoleptics tend to have a low quality of life (QoL). Few studies have compared QoL in narcolepsy against other sleep disorders. The purpose of this study was to... 相似文献