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1.
Randomly amplified polymorphic DNA (RAPD) genotyping was applied to one representative strain of each of the 84 electrophoretic types (ETs) of Neisseria meningitidis serogroup A previously defined by multilocus enzyme electrophoresis (MEE) (J.-F. Wang et al., Infect. Immun. 60:5267-5282, 1992). Twenty-seven additional isolates comprising six ETs were also tested. MEE and RAPD genotyping yielded similar dendrograms at the subgroup level. Similar results were obtained by both methods for 18 serogroup A meningococci isolated in The Netherlands between 1989 and 1993. Ten of these isolates defined a new subgroup, designated subgroup IX. One isolate belonged to the ET-5 complex, normally associated with serogroup B strains (D. A. Caugant et al., Proc. Natl. Acad. Sci. USA 83:4927-4931, 1986). By RAPD genotyping, meningococci can be linked to previously characterized genotypes by using a computerized database, and dendrograms based on cluster analyses can easily be generated. RAPD analysis offers advantages over MEE since intermediate numbers of isolates of serogroup A meningococci can quickly be assigned to known subgroups and new subgroups can be defined.  相似文献   

2.
Chromosome-substituted haploid segregants of an A. nidulans x A. tetrazonus somatic hybrid were used to allocate several random amplified polymorphic DNA and isoenzyme markers to parental chromosomes. Twenty-six amplified DNA fragments, and nine isoenzyme activities, including lactate dehydrogenase, superoxide dismutase, and arylesterase isoenzymes were assigned to chromosomes. Chromosomes-specific markers were found for each A. nidulans and A. tetrazonus chromosome. These markers could be used to saturate the genetic map of A. nidulans. The formation of two secondary metabolites was also assigned to chromosomes III and VIII. Attempts were made to allocate extracellular enzyme activities to parental chromosomes, mostly without success, possibly because multiple enzyme forms located on different chromosomes could be responsible for the production of an enzyme activity.  相似文献   

3.
OBJECTIVE: Factors such as size of hyphema, intraocular pressure, initial visual acuity, and use of steroids or antifibrinolytic drugs may be associated with the likelihood of rebleeding in traumatic hyphema. The association of the visual outcome with secondary hemorrhage has been questioned. DESIGN: Randomized, placebo-controlled, clinical trial. PARTICIPANTS: Two hundred and thirty-eight patients who had hyphema develop after blunt trauma. INTERVENTION: Eighty patients received oral tranexamic acid, 80 patients received placebo, and 78 patients received oral prednisolone. MAIN OUTCOME MEASURES: Secondary hemorrhage and vision at the time of discharge from the hospital were measured. RESULTS: Rebleeding occurred in 43 (18%) of the patients and was prevented significantly by oral tranexamic acid compared with the placebo (odds ratios [OR] = 0.39; 95% confidence interval [CI], 0.17, 0.89). Occurrence of secondary hemorrhage had weak associations with initial high intraocular pressure (OR = 2.7; 95% CI, 0.99, 7.3) and initial visual acuity of 6/60 or less (OR = 1.8; 95% CI, 0.9, 3.7). Secondary hemorrhage had no statistical association with age, gender, oral prednisolone, size of hyphema, and retinal damage. Visual acuity of 6/60 or less at the time of discharge was significantly associated with rebleeding (OR = 10.5; 95% CI, 3.7, 29.2), initial visual acuity of 6/60 or less (OR = 9.9; 95% CI, 2.8, 38.0), retinal damage (OR = 14.6; 95% CI, 3.8, 55.8), and male gender (OR = 6.5; 95% CI, 1.4, 31.9). Final visual acuity had no significant statistical association with age, use of oral prednisolone or tranexamic acid, and size of hyphema. CONCLUSIONS: High intraocular pressure and low vision at the time of first examination may be associated with increased chance of rebleeding. Retinal damage, secondary hemorrhage, male gender, and initial poor vision are associated with a worse visual outcome in patients with traumatic hyphema.  相似文献   

4.
The random amplified polymorphic DNA (RAPD) band patterns from 23 Salmonella spp. produced by use of an oligonucleotide primer (called du primer) designed on the basis of the N-terminal sequence of dulcitol 1-phosphate dehydrogenase (5'-GTGGTGACCCAGGATGGCCAGGTG-3') were different from those from 16 non-Salmonella spp. The bands at 460 and 700 bp were produced in all Salmonella strains tested. These RAPD fragments obtained from Salmonella typhimurium strongly hybridized with the corresponding RAPD bands from the other strains of Salmonella, but not with those from non-Salmonella spp. in Southern blot analysis. The RAPD bands were detected by ethidium bromide staining even when genomic DNA prepared from as few as 2.8 x 10(3) cells was used. The minimum detectable cell number in the initial inoculum of S. typhimurium was 4 x 10(-1) CFU/25 g of raw beef after the preenrichment in Enterobacteriaceae enrichment mannitol (EEM) broth for 6 h and the selective enrichment in dulcitol-magnesium chloride-pyridinesulfonic acid-brilliant green-novobiocin (DMPBN) medium for 18 h at 42 degrees C. Seven raw foods inoculated with S. typhimurium at numbers from 4 x 10(-1) to 2.6 x 10(2) CFU/25 g of food were positive in both the RAPD analysis and the conventional culture method.  相似文献   

5.
In adult rabbits, mid-diaphyseal segments of the radius or ulna were excised to produce defects greater than the critical size for spontaneous bone repair. The defects were enveloped in sleeves composed of nonbiodegradable expanded polyfluoroethylene (ePTFE), pore size 30, 60, 90 microns, and compared with sleeves of three biodegradable materials. Bone morphogenetic protein and associated noncollagenous bone matrix protein (BMP/NCP) or recombinant human morphogenetic protein (rhBMP-2) were implanted inside the sleeves. Albumin was implanted for a control system. Without intracompartmental BMP, only about 10%-15% of the defect was repaired by bone growth extending from the bone ends into the sleeves composed of ePTFE, pore size 30 microns. With sleeves with pore size 60 or 90 microns and intracompartmental BMP/NCP, 54%-96% regeneration occurred within 8 weeks after the operation. Sleeves of biodegradable nonimmunogenic materials such as polyorthoester (POE) and polylactic-polyglycollic acids (PLA/PGA) permitted 86%-98% restoration of bone continuity, but only when BMP was present in the lumen. With puncture holes (0.5 mm in diameter), implants of BMP/NCP in the 30-micron PTFE sleeve produced transmembrane external callus formation and bone regeneration to 147%. Sleeves composed of aorta first calcified, then induced complete intracompartmental bone regeneration. Atelocollagen sleeves incited a low-grade inflammatory cell reaction and did not promote complete regeneration. Under conditions presently undisclosed segments of the ulna bridged with ePTFE, were incompletely paired, even with intracompartmental BMP/NCP. Puncture holes of 0.5 mm admitted ingrowth of capillaries and introduced local conditions favorable for the response to BMP/NCP. BMP/NCP may promote proliferation of nutrient vessels and differentiation of bone marrow stroma cells between the open bone ends. For further investigation, the hypothesis to be examined is that the optimum response to BMP/NCP and rhBMP-2 would emerge in compartments containing first a high concentration gradient and second proliferating perivascular cells.  相似文献   

6.
Two collections of strains of Pasteurella were studied for epidemiological purposes by ribotyping and random amplified polymorphic DNA (RAPD) assays. These strains were isolated through two different structures of animal productions: cattle and rabbit. Forty strains of P. haemolytica from cattle reared in independent breeding-herds belonged to only 3 ribotypes after digestion with HindIII and PvuII. No further discrimination of these strains was obtained by RAPD assays. All these 40 strains showed more than 90% of similarity. This result was consistent with the hypothesis of a clonal dissemination of these strains in bovine herds, possible favoured by the large use of antibiotics. Forty-one strains of P. multocida were isolated in rabbits flocks belonging to 16 breeders. Six of these were linked by commercial relationships. Twenty-eight out of the 29 strains isolated through this commercial network belonged to only three ribotypes whereas the 12 strains from independant breeders belonged to 9 ribotypes. Results of RAPD assays were in accordance with those of ribotyping and validate the use of RAPD assays for epidemiological studies of Pasteurella strains.  相似文献   

7.
Molecular strain typing by pulsed-field gel electrophoresis and by randomly amplified polymorphic DNA analysis was used to investigate a cluster of four Nocardia asteroides isolates associated with the BACTEC 460 TB system. An instrument motor drive misalignment resulted in inadequate needle sterilization and cross-contamination of BACTEC vials. This pseudo-outbreak illustrates the importance of proper BACTEC 460 needle sterilization and maintenance and confirms the usefulness of molecular typing methods for epidemiologic investigations.  相似文献   

8.
To develop the molecular differentiation analysis of dermatophytes, we carried out RAPD and Southern hybridization analyses using genomic DNAs of six Arthroderma species, including A. fulvum, A. grubyi, A. gypseum, A. incurvatum, A. otae and A. racemosum. The RAPD analysis gave different band patterns specific to each of the six Arthroderma fungi. However, minor differences in the banding patterns were observed between the strains of plus (+) and minus (-) mating types of A. gypseum, A. fulvum and A. incurvatum. Southern blot analysis using a probe (1S) obtained from A. grubyi DNA gave specific bands only in the DNA samples of A. grubyi and A. incurvatum. On the other hand, Southern blot analysis using a probe (C3) obtained from A. otae DNA gave specific bands in all six Arthroderma species examined, and the size of the bands were specific to each species. These findings indicate that RAPD and Southern hybridization analyses are useful in the differentiation of these Arthroderma species.  相似文献   

9.
The physiological properties of joint capsule mechanoreceptors in the ankle joint of the chicken were studied in the 3-h period immediately after intra-articular injection of microcrystal sodium urate. The electrical activity was recorded from single C- and A-delta sensory fibres dissected from the parafibular nerve. C-fibres showed high levels of spontaneous activity and receptive fields that varied from single spots 1 mm in diameter up to 4 x 4 mm. Thresholds to mechanical stimulation ranged from 0.1 to 8 g and 80% of the units responded to movement of the joint. A-delta fibres showed little spontaneous activity and receptive fields that varied from 1 mm to 9 x 1 mm. Thresholds to mechanical stimulation ranged from 0.1 to 16 g and 17% responded to joint movement. A comparison of the physiological properties of the C- and A-delta fibres in sodium urate arthritis with similar fibres in normal and monoarthritic animals indicated an increased sensitivity in the C-fibres but not in the A-delta fibres. Sensitisation was observed in the significantly increased receptive field size, decreased response thresholds, increased response to joint movement and the high level of spontaneous activity. These changes in the sensitivity of the joint capsule C-fibre receptors provides peripheral neural evidence for the pain experienced in acute gouty arthritis.  相似文献   

10.
Multilocus enzyme electrophoresis and ribotyping were used to characterize 83 strains of Pseudomonas cepacia, mostly isolated from cystic fibrosis (CF) patients, although a number of isolates from non-CF nosocomial infections and reference environmental strains were represented. Twenty enzyme electrophoretic types (ETs) were determined; of these, one clone (ET12) was associated with six of nine ribotypes (RTs) said to be geographically representative of the United Kingdom and all of the Ontario (Canada) isolates from CF patients. This clone was not associated with nosocomial infections or environmental strains and was never found in CF isolates from British Columbia or Nova Scotia, Canada, or a center in the eastern United States. Individual isolate EcoRI RT signatures did not cluster geographically as did the ET signatures by clonal analysis. Frequently RTs occurred in more than a single ET. Known point source focal nosocomial outbreaks were typified by single ETs and stable RTs. Dendrographic analysis of the strains grouped those strains from CF patients, nosocomial outbreaks, and environmental sources into separate ET families, and diversity analysis indicated that, with the exception of ET17, CF isolates clustered in unique and closely related ETs different from those from nosocomial and environmental sources. This study has also shown the potential of multilocus enzyme electrophoresis to monitor the intercontinental spread of P. cepacia strains in CF patients, and this may have a significant impact on plans for CF patient summer camps and design of infection control practices. Whether the intercontinental ET12 clone, which predominates in the United Kingdom and the province of Ontario, linked by summer camp acquisition, has increased virulence for CF patients remains to be established.  相似文献   

11.
Differences in the 16S rRNA genes (16S rDNA) which can be used to discriminate Listeria monocytogenes from Listeria innocua have been detected. The 16S rDNA were amplified by polymerase chain reaction with a set of oligonucleotide primers which flank a 1.5-kb fragment. Sequence differences were observed in the V2 region of the 16S rDNA both between L. monocytogenes Scott A and L. innocua and between different L. monocytogenes serotypes. Although L. monocytogenes SLCC2371 had the same V2 region sequence as L. innocua, the two species were different within the V9 region at nucleotides 1259 and 1292, in agreement with previous studies (R.-F. Wang, W.-W. Cao, and M.G. Johnson, Appl. Environ. Microbiol. 57:3666-3670, 1991). Intraspecies discrimination of L. monocytogenes strains was achieved by using the patterns generated by random amplified polymorphic DNA primers. Although some distinction can be made within the L. monocytogenes species by their 16S rDNA sequence, a far greater discrimination within species could be made by generating random amplified polymorphic DNA patterns from chromosomal DNA. By using a number of 10-bp primers, unique patterns for each isolate which in all cases examined differentiate between various L. monocytogenes serotypes, even though they may have the same 16S rRNA sequences, could be generated.  相似文献   

12.
Food and clinical isolates of Listeria monocytogenes recovered from four different outbreaks of listeriosis were analyzed by their PCR-based randomly amplified polymorphic DNA (RAPD) patterns to verify their causal relationships. The generation of DNA fingerprints by PCR-based RAPD analysis is a fast and sensitive method for the epidemiological tracking and identification of bacteria implicated in food poisoning outbreaks. The L. monocytogenes strains used in the study were obtained from the following four outbreaks: California, 1985, Mexican-style cheese; Canadian Maritime Provinces, 1981, coleslaw; Canada, 1989, brie cheese; and Canada, 1989, alfalfa tablets. RAPD profiles were generated by using random 10-mer primers for at least one food and one clinical isolate recovered from each outbreak. Identical profiles for 20 different primers were observed for each pair of food and clinical isolates from two of the four outbreaks. Isolates from the outbreak involving alfalfa tablets exhibited identical patterns for 19 primers; however, primer OPA-1 produced one additional 1.8-kb fragment, designated OPA-1-1.8, that was found in the food isolate but not in the corresponding clinical isolate. Hybridization analysis revealed that the absence of the OPA-1-1.8 polymorphic fragment in the clinical isolate was due to a deletion of at least 1.8 kb. Loss of the OPA-1-1.8 polymorphic fragment could not be induced by infective passage of the L. monocytogenes isolate from the alfalfa tablet through a mouse or by growth of this isolate under selective conditions. This suggests that the isolate recovered from the food was not identical to the isolate recovered from the patient. The ability to produce unique RAPD patterns allows for the discrimination between isolates even if they are of the same serotype and multilocus enzyme electrophoretic type.  相似文献   

13.
A PCR assay, using three primer pairs, was developed for the detection of Ureaplasma urealyticum, parvo biovar, mba types 1, 3, and 6, in cultured clinical specimens. The primer pairs were designed by using the polymorphic base positions within a 310- to 311-bp fragment of the 5' end and upstream control region of the mba gene. The specificity of the assay was confirmed with reference serovars 1, 3, 6, and 14 and by the amplified-fragment sizes (81 bp for mba 1, 262 bp for mba 3, and 193 bp for mba 6). A more sensitive nested PCR was also developed. This involved a first-step PCR, using the primers UMS-125 and UMA226, followed by the nested mba-type PCR described above. This nested PCR enabled the detection and typing of small numbers of U. urealyticum cells, including mixtures, directly in original clinical specimens. By using random amplified polymorphic DNA (RAPD) PCR with seven arbitrary primers, we were also able to differentiate the two biovars of U. urealyticum and to identify 13 RAPD-PCR subtypes. By applying these subtyping techniques to clinical samples collected from pregnant women, we established that (i) U. urealyticum is often a persistent colonizer of the lower genital tract from early midtrimester until the third trimester of pregnancy, (ii) mba type 6 was isolated significantly more often (P = 0.048) from women who delivered preterm than from women who delivered at term, (iii) no particular ureaplasma subtype(s) was associated with placental infections and/or adverse pregnancy outcomes, and (iv) the ureaplasma subtypes most frequently isolated from women were the same subtypes most often isolated from infected placentas.  相似文献   

14.
Within the scope of the present study n = 183 MRSA isolates from the extended area of Düsseldorf and n = 93 international MRSA strains from seven different countries were typed by pulsed-field gel electrophoresis and two PCR methods (RAPD and 16S-23S-spacer amplification). The isolates could be subdivided into 30 different types by PFGE, into 21 by means of RAPD and 18 by 16S-23S-spacer amplification. PFGE had the highest discriminatory potential, however, a combined use of the three typing methods allows a more detailed differentiation even of those isolates with identical PFGE pattern. Both amplification procedures were rapid, easy in handling with reproductable results. For a temporary epidemiological analysis within 24 hours, both amplification methods could be combined. In case the investigated isolates were still suspected of showing a "clonal identity", they should be analysed by additional PFGE (lasting about four days). Although the international isolates were chosen by random selection, several MRSA strains with identical pattern could be found in different countries of the world. Some RAPD-, spacer- and PFGE pattern were constant over many years. This reflects a high genetic stability of single strains.  相似文献   

15.
A study involving the use of random amplified polymorphic DNA (RAPD) was conducted to evaluate genetic polymorphism and relatedness within and among four chicken breeds: Araucona, Rhode Island Red, White Leghorn, and White Plymouth Rock, and two turkey populations, a long-term randombred and a commercial strain. A total of 60 random primers were used in the RAPD analyses. Forty-two of the 60 primers tested amplified patterns with at least one polymorphic fragment in one or more of the populations. Six of these 42 primers amplified polymorphic fragments in each of the six strains with a within- and between-population average band-sharing frequency of less than one but above zero (P < 0.05). Differences among the six primers for genetic distance (D) among populations were significant (P < 0.05). A consensus dendogram was therefore developed to show the phylogenetic relationships among the populations. As expected, estimates of D between populations were lowest within species and highest between species. The results provide evidence of the applicability of RAPD to determining genetic relatedness within and among different poultry populations and in developing reproducible markers useful in evaluating individual variation in chickens and turkeys.  相似文献   

16.
We evaluated levels of mannose-6-phosphate/insulin growth factor-II receptor (M6P/IGFII-R) RNA in 37 breast cancer tumors by quantitative in situ hybridization using a computer-aided image analyzer and compared them to cathepsin D RNA and protein levels in the same tissues. Breast cancer cells expressed more cathepsin D and M6P/IGFII-R RNA than fibroblasts in the same tumors. We found a significant increase of cathepsin D RNA (P = 1 x 10(-5)) and M6P/IGFII-R RNA (P = 0.02) in breast cancer cells compared to epithelial cells of benign mastopathies. There was a positive correlation (r = 0.65; P = 1 x 10(-5)) between M6P/IGFII-R and cathepsin D RNA levels measured on serial sections. This contrasted with the inverse relationship of these 2 RNA species in breast cancer cell lines where estrogen down-regulates M6P/IGFII receptor RNA levels. Moreover, in vivo we found no correlation between the M6P/IGFII-R RNA level and menopausal or estrogen receptor status, suggesting that the in vivo regulation of M6P/IGFII-R RNA differs from its in vitro regulation in cell lines. The M6P/IGFII-R RNA level was not correlated with cathepsin D status, histological grade, and tumor size but was significantly higher in lymph node-positive tumors (P = 0.047). The M6P/IGFII-R could therefore be an additional parameter to predict aggressive breast cancers, complementing cathepsin D assays and other more classical prognostic parameters.  相似文献   

17.
Polymorphonuclear leukocytes (PMNs) isolated from peripheral blood and synovial fluid of patients with rheumatoid arthritis and from peripheral blood of volunteers were stimulated with 12-phorbol-13-myristate acetate (PMA). No significant differences in luminol-amplified chemiluminescence were found between different patients and control groups. However, two distinct patterns of native chemiluminescence were observed. Type I showed no, or only a small, increase in native chemiluminescence with integral counts over 30 min less than 3 x 10(5) cpm, and the majority of samples from volunteers were of this type. Type II was characterized by a burst of native chemiluminescence starting 8 to 15 min after cell stimulation. It was found in most PMN samples from patients with rheumatoid arthritis. Integral counts over 30 min were always higher than 10(6) cpm and as high as 10(8) cpm in some cases. A strong inhibition of the Type II native chemiluminescence was caused by desferal, catalase, thiourea, and glutathione. However, the luminol-amplified chemiluminescence remained unchanged or was only slightly decreased under the same experimental conditions. Sodium azide strongly inhibited both kinds of luminescence. Hydroxyl radicals, formed in a Fenton reaction, may be important intermediates in the Type II native chemiluminescence.  相似文献   

18.
Sequencing by the recently reported hybridization technique requires the formation of DNA duplexes with similar stabilities. In this paper we describe a new strategy to obtain DNA duplexes with a thermal stability independent of their AT/GC ratio content. Melting data were acquired on 35 natural and 27 modified duplexes of a given length and of varying base compositions. Duplexes built with AT and/or G4EtC base pairs exhibit a thermal stability restrained to a lower range of temperature than that of the corresponding natural compounds (16 instead of 51 degrees C). The 16 degrees C difference in thermal stability observed between the least stable and the most stable duplex built with AT and/or G4EtC base pairs is mainly due to the sequence effect and not to their AT/G4EtC ratio content. Thus N -4-ethyl-2'-deoxycytidine (d4EtC) hybridizes specifically with natural deoxyguanosine leading to a G4EtC base pair whose stability is very close to that of the natural AT base pair. Oligonucleotide probes involving d4EtC can be easily prepared by chemical synthesis with phosphoramidite chemistry. Modified DNA targets were successfully amplified by random priming or PCR techniques using d4EtCTP, dATP, dGTP and dTTP in the presence of DNA polymerase. This new system might be very useful for DNA sequencing by hybridization.  相似文献   

19.
OBJECTIVE: Our purpose was to determine whether urinary estrone conjugates (E1C) as measured by enzyme immunoassay correlate with serum estradiol (E2) in women undergoing controlled ovarian hyperstimulation with human menopausal gonadotropins. DESIGN: This was a prospective, clinical study. SETTING: The study took place in an outpatient, university-affiliated in vitro fertilization (IVF) unit. INTERVENTIONS: First morning urine samples were analyzed for E1C using a competitive solid-phase microtiter enzyme immunoassay and the value was corrected for urinary creatinine (E1C/Cr). The value was compared to morning serum E2 as determined by radioimmunoassay. RESULTS: Mean E2 and E1C/Cr levels demonstrated a similar pattern on the days before hCG administration. The correlation between E1C and E2 was 0.85 (P < 0.0001). Furthermore, the correlation between the number of follicles greater than 12 mm was as high for E1C/Cr (rho = 0.71, P < 0.001) as it was for E2 (rho = 0.74, P < 0.0001). CONCLUSIONS: Urinary E1C/Cr levels in women receiving hMG correlate with serum E2. Further studies are necessary to determine whether E1C is clinically useful to predict ovarian hyperstimulation syndrome.  相似文献   

20.
Human papillomavirus (HPV) types 16 and 18 in 66 women with histologically documented lesions of the genital tract and 64 control cohorts were investigated. The efficacies of in situ hybridization and polymerase chain reaction (PCR) in detecting HPV 16 and 18 DNA were analyzed. In order to assess the usefulness of replacing biopsies with cervical scrapes, the two samples were compared by PCR. The prevalence rates of HPV infection by PCR were 59.1 and 10.9% in patients and controls, respectively. PCR was three times more sensitive than in situ hybridization (52.6 versus 17.8%). However, the need to improve PCR sensitivity by subsequent dot blot hybridization reduced one of the main advantages of PCR, i.e., expeditious diagnosis. Cervical scrapes were less sensitive than biopsies (13.6 versus 53%), although with four (6.1%) patients with intraepithelial neoplasias, HPV DNA was identified only by means of cervical scraping. We conclude that obtaining biopsy specimens and cervical scraping are complementary sampling procedures.  相似文献   

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