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41.
An extracellular lipase from Streptomyces rimosus R6-554W has been recently purified and biochemically characterized. In this report the cloning, sequencing, and high-level expression of its gene is described. The cloned DNA contained an ORF of 804 bp encoding a 268-amino-acid polypeptide with 34 amino acid residues at the amino terminus of the sequence that were not found in the mature protein. The theoretical molecular mass (24.172 kDa) deduced from the amino acid sequence of the mature enzyme was experimentally confirmed. This lipase showed no overall amino acid sequence similarity to other lipases in the databases. However, two hypothetical proteins, i. e. putative hydrolases, derived from the genome sequencing data of Streptomyces coelicolor A3(2), showed 66% and 33% identity. In addition, a significant similarity to esterases from Streptomyces diastatochromogenes and Aspergillus terreus was found. Sequence analysis revealed that our novel S. rimosus lipase containing a GDS(L)-like consensus motif belongs to family II of lipolytic enzymes, previously unrecognized in Streptomyces. When the lipase gene was expressed in a S. rimosus lipase-deficient strain harboring the lipase gene on a high-copy-number vector, lipase activity was 22-fold higher than in the original strain.  相似文献   
42.
From a genetic standpoint, Streptomyces rimosus is arguably the best-characterized industrial streptomycete as the producer of oxytetracycline and other tetracycline antibiotics. Although resistance to these antibiotics has reduced their clinical use in recent years, tetracyclines have an increasing role in the treatment of emerging infections and noninfective diseases. Procedures for in vivo and in vitro genetic manipulations in S. rimosus have been developed since the 1950s and applied to study the genetic instability of S. rimosus strains and for the molecular cloning and characterization of genes involved in oxytetracycline biosynthesis. Recent advances in the methodology of genome sequencing bring the realistic prospect of obtaining the genome sequence of S. rimosus in the near term.  相似文献   
43.
44.
Two bifunctional plasmid vectors pZG5 (7.45 kb) and pZG6 (6.95 kb), for gene transfer between Streptomyces spp. and Escherichia coli have been constructed by fusion of the multicopy broad-host-range Streptomyces plasmid pIJ350 with E. coli plasmids Bluescribe M13- (pZG5) or pUC18 (pZG6). Both plasmids possess several unique restriction sites suitable for DNA cloning. Stable transformants of Streptomyces rimosus R6 and S. lividans 66 were obtained, harboring intact plasmids regardless of colony age or multiple subculturing. Moreover, pZG5 and pZG6 were successfully used to introduce several homologous transfer RNA genes into S. rimosus.  相似文献   
45.
Various combinations of vascular malformations of the brain in one lesion have been reported, while others seem to be very rare. In this report, the authors discuss the case of a coexistence of an capillary telangiectasia of the pons and intracerebral venous anomaly. To our knowledge, this is the first report of coexistence of a capillary telangiectasia of the pons and intracerebral venous anomaly apparted from each other. These discrete vascular malformations of the brain raise attention on possible interrelations in the pathogenesis of these entities. We report a case of pontine capillary telangiectasia and intracerebral venous anomaly in a 42-year-old woman with a right side facial palsy. Hight field magnetic resonance imaging suggested presence of a capillary telangiectasia of the pons. Another lesion in the left frontal gyrus was attributable to the venous anomaly. Along with neuroradiological findings, results of the somatosensor evoked potentials, brain stem auditory potentials, laboratory analysis including blood, cerebrospinal fluid and urine investigation are demonstrated. Awareness of the magnetic resonance imaging finding of the capillary telangiectasias and of the venous anomalies may help in defining clinical correlates of this vascular malformations, while the follow up of these malformations might help to asses risk of vascular rupture. We and others previously selects capillary telangiectasia and venous anomaly in two discrete entities. Coexistence of these malformations in the brain apparted from each other appear to be very rare and raise attention on possible interactions in their natural history and pathogenesis.  相似文献   
46.
Analysis of masticatory function is the basis of clinical work in almost all fields of dentistry. Bite forces are the expression and measure of masticatory function. Physical training has an effect on the development of functional ability, motoric ability of the organism and the formation of desired physical proportions. The purpose of this study was to examine the association between physical fitness and bite force values. Because of strictly defined regulations in the army with regard to training and nutrition, Croatian Army recruits were ideal examinees for this examination. The examinees were 135 recruits. Bite forces were measured on three places (area of the central incisors, left and right in the area of the first molars) before and after three-months of training. Of all the examinees, 108 had increased their body weight, 12 had decreased it and 15 had not changed their body weight. The median of measured forces in the recruits prior to training was 291 N in the right (lateral quadrant), 285.5 N in the left lateral quadrant and 205 N in the anterior area. After training the median of measured forces in the right quadrant was 312 N, in the left 313 N and in the anterior area 216 N Greater bite forces after training on all measured places were statistically proved. Increased activity of masticatory muscles can have the same effect on the values of bite forces as bite training. There are few data on the correlation between physical muscles and values of bite forces. The results of those studies are doubtful. In this study, after three months of conditional training, the body mass of the recruits had increased and they expressed greater values of bite forces. However, correlation between body mass and bite forces cannot be proved with certainty.  相似文献   
47.
The reproductive development of the Christmas rose (Helleborus niger L.) is characterized by an uncommon feature in the world of flowering plants: after fertilization the white perianth becomes green and photosynthetically active and persists during fruit development. In the flowers in which fertilization was prevented by emasculation (unfertilized) or entire reproductive organs were removed (depistillated), the elongation of the peduncle was reduced by 20?C30%, and vascular development, particularly lignin deposition in sclerenchyma, was arrested. Chlorophyll accumulation in sepals and their photosynthetic efficacy were up to 80% lower in comparison to fertilized flowers. Endogenous auxins were investigated in floral and fruit tissues and their potential roles in these processes are discussed. Analytical data of free indole-3-acetic acid, indole-3-ethanol (IEt), and seven amino acid conjugates were afforded by LC-MS/MS in floral tissues of fertilized as well as unfertilized and depistillated flowers. Among amino acid conjugates, novel ones with Val, Gly, and Phe were identified and quantified in the anthers, and in the fruit during development. Reproductive organs before fertilization followed by developing fruit at post-anthesis were the main source of auxin. Tissues of unfertilized and depistillated flowers accumulated significantly lower levels of auxin. Upon depistillation, auxin content in the peduncle and sepal was decreased to 4 and 45%, respectively, in comparison to fruit-bearing flowers. This study suggests that auxin arising in developing fruit may participate, in part, in the coordination of the Christmas rose peduncle elongation and its vascular development.  相似文献   
48.
In this paper we report the results of the microbiological analysis of the samples taken from the mummy from the collection of the Archaeological museum in Zagreb, Croatia. Samples were taken from specific places such as oral, orbital, abdominal cavity and bandages surrounding the mummy, and analyzed in Department of Microbiology and Hospital Infections in University Hospital "Dubrava" in Zagreb and in National Reference Laboratory for systemic mycoses of Croatian National Institute of Public Health in Zagreb. The analysis indicated that all of the found organisms were non-primary pathogenic and are not harmful for healthy humans. Isolated microorganisms mainly belonged to the group of saprophytic fungi as listed: Monilia spp., Penicillium spp., Alternaria spp., Aspergillus fumigatus, Aspergillus nidulans, Rhizopus spp. and Chrysosporium spp. and to the genus of saprophytic bacteria, Bacillus spp.  相似文献   
49.
A screening programme to detect preinvasive carcinoma of the cervix was started in British Columbia in 1949. Since 1970 the number of women who have been screened at least once has been maintained at about 85% of the population at risk. More than 500 000 cervical smears are being examined each year in the central laboratory. There has been an appreciable increase in the number of cases and rates of carcinoma in situ seen since 1970, particularly in women between 20 and 30 years of age. Since the programme started over 26 000 cases of squamous carcinoma in situ have been detected and treated. The incidence of clinically invasive squamous carcinoma of the cervix has fallen by 78% during the period under review, and mortality from squamous carcinoma of the cervix has fallen by 72%. A colposcopy programme, introduced throughout British Columbia over the past 12 years, has been important in reducing the problems of managing preinvasive lesions, particularly in younger women.It is concluded that the reduction in morbidity and mortality from invasive squamous cancer of the cervix in British Columbia over the past 30 years is directly attributable to the province wide screening programme and that a large potential increase in invasive cervical cancer rates among younger women is being prevented.  相似文献   
50.
The aim of this study was to determine level of serum IgA, IgG and IgM in patients with OLR as indicators of humoral immunity which might reflect cell-mediated immunity. This study was conducted on 30 patients (age 60.17 +/- 11.75) with clinically and histopathologically confirmed diagnosis of OLR and 30 healthy controls (age 56.16 +/- 11.82) Determination of serum IgA, IgG and IgM was performed by use of standard laser nephelometry in both patients and controls. Statistical analysis was done using Mann-Whitney U test and the level of significance was determined as p values lower than 0.05. Serum IgA and IgM in patients with OLR were significantly increased in comparison to the control group, while serum IgG levels were higher in patients with OLR but they did not reach significance. We might conclude that elevated levels of serum IgA and IgM show that humoral immunity is implicated in the pathogenesis of OLR.  相似文献   
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