This first comprehensive serological analysis of an haemolytic uraemic syndrome (HUS) outbreak in which a wide range of 'O' group Escherichia coli antibody responses in patients and controls provided a unique insight into the epidemiology of such epidemics. Possible answers to clinical aspects related to severity of disease and complications were revealed. A microagglutination assay was used to examine E. coli 'O' group serological responses in 49 serum samples of 21 children hospitalised with HUS and 14 single samples from contemporaneous age-matched controls. A total of 51 O serogroup strains were used, including those reported to be associated with cases of HUS, with six isolates from patients associated with the Adelaide outbreak, environmental verocytotoxi-genic/shiga-toxin producing E. coli (VTEC/STEC) strains and common human commensal strains. Amongst the 21 patients, there were 226 instances of seroreactivity (titre > or = 100) against 34 E. coli serogroups while six instances of seroreactivity against four serogroups occurred in controls. There were 128 instances in patients and one instance in controls in which titres > or = 400 were observed. All 21 patients were seroreactive (titre > or = 100 and <400) to one or more of the 17 HUS-associated serogroups included in the study. Titres ranged from 100 to 6,400, some of the highest in three patients were against O157, whose faeces yielded only EHEC O111, and only one developed O111 antibody. Mixed infection was demonstrated serologically by microagglutination (confirmed by western blot) and was consistent with the multiple serogroups of VTEC found in the mettwurst incriminated as the source, and suggests further strains (not found in the source or in patients' faeces) were probably involved. In HUS-associated EHEC infection, multiple strain infection may be the rule rather than the exception. Analysis of 34 of the 51 serogroup antibody responses in the HUS patients revealed clues to possible relationships with clinical severity and complications. Patients with severe renal failure tended to develop antibodies to a larger number of serogroups than those with moderate or mild impairment. The same was true for central nervous system complications. Other associations were observed. While VTEC O157 remains an important causal serogroup in HUS, non-O157 serogroups also appear to play a significant role and therefore the latter should always be sought in all future HUS cases as new insights into pathogenicity may be discovered. This study indicates that co-infection with different VTEC serogroups may affect clinical outcome. 相似文献
Collaborative work was financed by the EU to develop and assess new diagnostic tools that can differentiate between bovine brucellosis and bovine infections due to Yersinia enterocolitica O:9 either in conjunction with, or as an alternative to, the classical serological, bacteriological or allergic skin tests. Sixteen heifers were experimentally infected with Brucella abortus biovar 1 (five heifers), Brucella suis biovar 2 (two heifers), Y. enterocolitica O:9 (six heifers) and Y. enterocolitica O:3 (three heifers). Four heifers, naturally infected with Y. enterocolitica O:9 that presented aspecific brucellosis serological reactions were also included in the experiment. A self-limited infection was induced in cattle by B. suis biovar 2. All the brucellosis serological tests used, i.e. the slow agglutination test (SAW), the Rose Bengal test (RB), the complement fixation test (CFT), indirect and competitive ELISA’s, lacked specificity when used to analyze sera from Y. enterocolitica O:9 infected animals. A Yersinia outer membrane proteins (YOPs)-ELISA was also used and although the test is able to detect a Yersinia group infection, it provided no evidence of whether or not there is a possible brucellosis infection when dual infections are present. The brucellergen IFN-γ test showed a lack of specificity also. The only test that was proven to be specific is the brucellergen skin test. All brucellosis serological tests, except the indirect ELISA, were limited in their ability to detect B. abortus persistently infected animals.
Based on these experimental studies, a strategy was implemented as part of the year 2001 Belgian Brucellosis Eradication Program to substantiate the eradication of bovine brucellosis. Epidemiological inquiries have identified risk factors associated with aspecific serological reactions, possible transmission and infection of cattle by B. suis biovar 2 from infected wild boars; and both legal and administrative measures taken by the veterinary services. No cases of bovine brucellosis have been confirmed in Belgium since March 2000. 相似文献
Following pretreatment with clindamycin, cleaning, scaling, polishing, and curettage, six beagles that were patients at the Dental Department of the Clinic for Surgery and Ophthalmology of the University of Veterinary Medicine of Vienna received a doxycycline polymer filling (Doxirobe, Pharmacia Animal Health) in periodontal pockets of teeth 204, 208, 304, and 309. Gingivitis index, gingival crevicular fluid, probing depth, and attachment loss were determined before and 6 and 12 weeks after treatment. Teeth 104, 108, 404, and 409 did not receive antibiotic therapy but were pretreated in the same manner as the doxycycline-treated teeth. Pocket depth for teeth treated with doxycycline was significantly reduced (improved) by 39% after 6 weeks (P =.001) and by 35% after 12 weeks (P =.001). Pockets around control teeth were improved after cleaning and curettage but were still significantly deeper than around teeth treated with doxycycline. Compared with control teeth, teeth treated with doxycycline had significantly less gingival crevicular fluid after treatment (P =.001). Teeth treated with doxycycline gained significant attachment after 6 (42%) and 12 (38%) weeks. Significantly fewer bacteria were harvested from doxycycline-treated teeth than from control teeth. The gingival index was significantly lower in the doxycycline-treated teeth than in the control teeth 6 (P =.002) and 12 (P =.007) weeks after treatment. Local application of doxycycline complements traditional subgingival curettage therapy in a reasonable and effective way and can significantly improve treatment success, especially with regard to pocket depth reduction and attachment gain. 相似文献
The advanced very high resolution radiometer (AVHRR) is an operational, high-quality, crosstrack, line-scanning multispectral radiometer. Its data at 1.1 km maximum spatial resolution, 2800 km swath width and five spectral bands have widespread applications in meteorology, oceanography, climatology, agriculture, hydrology, forestry and many other disciplines. Two AVHRR are maintained in continuous operational mode, borne by two National Oceanic and Atmospheric Administration (NOAA) polar orbiting satellites. Particularly valuable is the fact that this operational system provides imagery of all parts of the globe at least four times daily, large portions of which are archived centrally in several data centers around the world. Historical data are available back to 1985.
As a remote sensing system, the NOAA/TIROS-N satellites are arguably one of the most successful and extensively used components of the US space program. Through the direct-broadcast system, environmental data from the AVHRR and other sensors have been made available around the world to properly equipped users of all nations. The data are broadcast in two modes, automatic picture transmission (APT, low-cost, low-resolution, two-channel data) and high resolution picture transmission (HRPT, full resolution, all channels and other sensor data).
The purpose of this paper is to briefly describe the system, outlining its limitations and capabilities, to help potential new users keep their expectations within realistic levels. There are five categories of limitations on the utility of the AVHRR data for Earth surface applications: (1) spatial resolution and its space-time variability; (2) atmospheric effects on measurements; (3) no in-flight calibration of visible and near-infrared sensors; (4) special problems with the mid-infrared sensor; (5) the wide spectral sensitivity bands of the data channels. 相似文献
The purpose of this paper is to analyse, at the stand level, how genetical or simply biotechnological progress affects the socially optimal rotation period and the value of forest land. The question has relevance for forest policy, since in many countries there are rules which regulate the shortest permissible rotation period. Given that biotechnology improves over time, one could ask in what direction and at what rate the shortest permissible rotation period should be changed. The results of this paper provide some qualitative insights into the matter. 相似文献
Zusammenfassung Aus Blättern der KartoffelpflanzeSolanum tuberosum Aquila wurde außer Cycloartenol (I), 24-Methylen-cycloartanol (II) (?), Lophenol (III), 24-Methylen-(IV) und 24-Äthyliden-lophenol (V) in 0,05%iger Ausbeute (bezogen auf Blatt-Trockengew.) ein Steringemisch isoliert, das nach dem Molekül-Massenspektrum (Ionisierung durch Anlagerung energiearmer negativer Ladungsträger) aus etwa 49% -Sitosterin (VIII), 36% Stigmasterin (IX), 12% Cholesterin (VI) und 3% Campesterin (VII) zusammengesetzt ist. Weiterhin ließen sich die homologen n-Paraffine C25H52 bis C33H68 und iso-Paraffine C29H60 bis C33H68 (Hauptkomponente mit ca. 51% n-Hentriacontan) sowie geringe Mengen höherer aliphatischer Ketone, vor allem Tritriacontanon, gaschromatographisch bzw. molekülmassenspektrographisch nachweisen.
Summary In addition to cycloartenol (I), 24-methylene-cycloartanol (II) (?), lophenol (III), 24-methylene-(IV) and 24-ethylidene-lophenol (V) a mixture of sterols has been isolated from leaves of the potato plantSolanum tuberosum Aquila (0,05% of the dry weight), which, according to our molecular mass spectrographic investigations employing negative ionization, contains approximately 49% -sitosterol (VIII), 36% stigmasterol (IX), 12% cholesterol (VI), and 3% campesterol (VII). Furthermore the homologous n-alkanes C25H52 to C33H68 and iso-alkanes C29H60 to C33H68 (the main component being n-triacontane with ca. 51%) as well as some higher aliphatic ketones, especially tritriacontanone, have been detected by gas-liquid chromatographic and molecular mass spectrographic methods.
VII. Mitteilung: von Ardenne und Mitarb. (1965b).Zugleich IV. Mitteilung der Reihe Molekül-Massenspektrographie von Naturstoffen. — III. Mitteilung: von Ardenne und Mitarb. (1965b).Forschungsinstitut Manfred von Ardenne, Dresden-Weißer Hirsch.Teil der Dissertation von G. Osske, Univ. Halle, 1963. 相似文献