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951.
OBJECTIVE: To study the prognostic significance of nuclear shape analysis in ependymomas. STUDY DESIGN: Tumor cell nuclei in surgical specimens of primary resected ependymomas from 30 patients were evaluated by means of Fourier analysis of nuclear contours, conventional morphometric features (nuclear area, shape factor) and the Ki-67 proliferation index. Fourier analysis can be used for decomposing an irregular nuclear contour by calculating "Fourier amplitudes." Tumors with different tumor grades according to the World Health Organization were compared, as were patients with and without recurrence of ependymomas. Planimetric data were further correlated with the Ki-67 index. RESULTS: t Test and multivariate analysis showed distinct differences between ependymomas with tumor grade 3 and the other tumor grades. Cross-validated, stepwise discriminant analysis with the event of recurrence as grouping variable revealed correct reclassification in 16/18 cases without recurrence and of 10/12 cases with recurrence. When considering just intracranial ependymomas with total surgical removal, Fourier amplitudes provided 100% correct reclassification concerning recurrence. Proliferation index, in contrast, showed considerable overlap between all tumor grades and between cases with and without recurrence. CONCLUSION: Quantification of the shape of tumor cell nuclei in ependymomas by means of Fourier analysis has prognostic significance and seems to be superior to the Ki-67 index.  相似文献   
952.
953.
The use of microorganisms for bioremediation of contaminated soils may be enhanced with an understanding of the pathways involved in their degradation of hazardous compounds. Ralstonia sp. strain RJGII.123 was isolated from soil located at a former coal gasification plant, based on its ability to mineralize carbazole, a three-ring N-heterocyclic pollutant. Experiments were carried out with strain RJGHII.123 and 14C-carbazole (2 mg/L and 500 mg/L) as the sole organic carbon source. At 15 days, 80% of the 2 mg/L carbazole was recovered as CO2, and <1% remained as undegraded carbazole, while 24% of the 500 mg/L carbazole was recovered as CO2 and approximately 70% remained as undegraded carbazole. Several stable intermediates were formed during this time. These intermediates were separated by high performance liquid chromatography (HPLC) and were characterized using high resolution mass spectroscopy (HR-MS) and gas chromatography - mass spectroscopy (GC-MS). At least 10 ring cleavage products of carbazole degradation were identified; four of these were confirmed as anthranilic acid, indole-2-carboxylic acid, indole-3-carboxylic acid, and (1H)-4-quinolinone by comparison with standards. These data indicate that strain RJGII.123 shares aspects of carbazole degradation with previously described Pseudomonas spp., and may be useful in facilitating the bioremediation of NHA from contaminated soils.  相似文献   
954.
Probabilities for secondary cancer incidence have been estimated for a patient with Hodgkin's disease for whom treatment has been planned with different radiation modalities using photons and protons. The ICRP calculation scheme has been used to calculate cancer incidence from dose distributions. For this purpose, target volumes as well as critical structures have been outlined in the CT set of a patient with Hodgkin's disease. Dose distributions have been calculated using conventional as well as intensity-modulated treatment techniques using photon and proton radiation. The cancer incidence has been derived from the mean doses for each organ. The results of this work are: (a) Intensity-modulated treatment of Hodgkin's disease using nine photon fields (15 MV) results in nearly the same cancer incidence as treating with two opposed photon fields (6 MV). (b) Intensity-modulated treatment using nine proton fields (maximum energy 177.25 MeV) results in nearly the same cancer incidence as treating with one proton field (160 MeV). (c) Irradiation with protons using the spot scanning technique decreases the avoidable cancer incidence compared to photon treatment by a factor of about two. This result is independent of the number of beams used. Our work suggests that there are radiotherapy indications in which intensity-modulated treatments will result in little or no reduction of cancer incidence compared to conventional treatments. However, proton treatment can result in a lower cancer incidence than photon treatment.  相似文献   
955.
Glucosinolates are nitrogen- and sulfur-containing plant natural products that have become increasingly important in human affairs as flavor precursors, cancer-prevention agents, and crop protectants. While many glucosinolates are biosynthesized from common amino acids, the major glucosinolates in economically important species of the Brassicaceae, such as Brassica napus (oilseed rape), are thought to be formed from chain-elongated derivatives of methionine or phenylalanine. We investigated the chain elongation pathway for methionine that is involved in glucosinolate biosynthesis in Eruca sativa. Isotopically labeled methionine and acetate were administered to cut leaves and the major product, 4-methylthiobutylglucosinolate (isolated as its desulfated derivative), was analyzed by MS and NMR. Administration of ?U-(13)Cmethionine showed that the entire carbon skeleton of this amino acid, with the exception of the COOH carbon, is incorporated as a unit into 4MTB. Administration of ?(13)C- and ?(14)C?cetate gave a labeling pattern consistent with the operation of a three-step chain elongation cycle which begins with the condensation of acetyl-CoA with a 2-oxo acid derived from methionine and ends with an oxidative decarboxylation forming a new 2-oxo acid with one additional methylene group. Administration of ?(15)Nmethionine provided evidence for the transfer of an amino group to the chain-elongated 2-oxo acid, forming an extended amino acid which serves as a substrate for the remaining steps of glucosinolate biosynthesis. The retention of a high level of (15)N in the products suggests that the amino transfer reactions and the chain elongation cycle are localized in the same subcellular compartment.  相似文献   
956.
Plasmid pGBG1 was constructed to isolate mobile genetic elements in a wide variety of gram-negative bacteria. The mutation target, carried on a broad-host-range vector, allows positive selection for tetracycline resistance. In tests using several gram-negative bacteria we could detect transposition events of either insertion sequences or transposons. A new insertion sequence (IS) element was identified in Ralstonia eutropha.  相似文献   
957.
In human immunodeficiency virus (HIV) infection, serum level of zinc, an important micronutrient for immune function, is frequently diminished. The aim of this study was to determine the zinc status in relation to immunological parameters and disease stage in 79 HIV-1 seropositive patients. The median serum level of zinc was within normal limits (12.5 micromol/L) but in 23% of patients, zinc deficiency was seen. Decreased serum zinc was associated with a low CD4 cell count, high viral load, and increased neopterin and IgA levels. According to current treatment recommendations, the majority of patients received antiretroviral triple therapy. Zinc levels in treated and untreated patients were comparable. Referring to disease stage (CDC classification, 1993), the mean zinc level was highest in stage C and lowest in stage A. In conclusion, even under antiretroviral triple therapy, zinc deficiency is still of great importance in HIV infection, and zinc substitution in zinc deficient individuals should be taken into account to optimize therapeutical success.  相似文献   
958.
959.
Zusammenfassung Zwischen 2. und 10. Mai 1997, dem Höhepunkt territorialer Aktivität, wurden im Lianhuashan-Reservat (Gansu, China) Territorial- und Werbeverhalten anhand von 18 farbberingten und besenderten Chinahaselhühnern mittels Ton- und Videotechnik verfolgt. Die Hähne markieren ihre Reviere durch instrumentale Flügelgeräusche, die durch Flattersprünge am Boden, seltener durch Revierflüge hervorgebracht werden. Die Flattersprunghäufigkeit kulminiert am frühen Morgen, die Nahrungsaufnahme am Abend. Die erste Paarung fand am 9. Mai statt.
Territorial and courtship behaviour of Chinese Grouse(Bonasa sewerzowi)
Summary Field observations, sound and video recordings of the rare endemic Chinese Grouse were carried out during May 2 and 10, 1997, the optimal time to study display, in the Lianhuashan reserve (Gansu province) at altitudes between 2800 and 3200 m a.s.l. We found the density in spring extraordinarily high: 15 occupied territories/km2 in the best studied plot. 18 colour-banded and radio-tagged birds were recorded. We were able to record on tape most of the vocal and instrumental sounds produced by the displaying grouse. Chinese grouse males perform a wing-beat display. The main elements of the territorial activity were variable flutter-jumps on the ground up to 1 m high and 2–4 m wide, sometimes also from a tree to the ground and vice-versa, producing instrumental sounds. An evident peak of flutter jumping activity was observed just after the birds left the roost tree in the morning (5.30 h local time) up to 8 o'clock. Noisy territorial flights in the crowns of trees were rarely observed. The low frequency sounds produced by the wings of the jumping cocks produced a typical impressive morning concert, especially, if 3–4 conflicting males came close together. First copulation was recorded on May 9. In the mating time, flutter jumping activity abated considerably.
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960.
Zusammenfassung Im Februar 1992 wurde an der in Bau befindlichen Autobahn BAB 66 zwischen Steinau und Schlüchtern (5021'N, 0931'E) ein Nistkastenkontrollgebiet mit 310 Nistkästen eingerichtet, um die Auswirkungen der Autobahn vor und nach Inbetriebnahme auf die Brutbiologie von Meisen zu untersuchen. Als Vergleichsgebiete dienen ein direkt benachbartes sowie ein ca. 5 km entferntes Untersuchungsgebiet. Zum Vergleich der Gewichtsentwicklung der Nestlinge wurde ein drittes autobahnfernes Gebiet herangezogen.In einzelnen Jahren finden sich zwischen den Gebieten Unterschiede in der Zusammensetzung der Brutpopulation, der Besetzungsrate der Nistkästen, dem Legebeginn, der Gelegegröße, der Schlüpfrate oder im Bruterfolg. Diese Unterschiede treten in verschiedenen Jahren und in unterschiedlichen Gebieten auf, so daß sich keine generelle Abweichung des Gebietes an der Autobahn von den straßenfernen Gebieten feststellen läßt. Die Eröffnung der Autobahn hatte keinen Effekt auf die untersuchten Parameter.Die Gewichte der Nestlinge im Gebiet an der Autobahn waren im Jahr 1996 nur am 12. und 13. Nestlingstag signifikant geringer als die Gewichte der Nestlinge in einem autobahnfernen gleichartig strukturierten Biotop. Die Ausflugsgewichte der Jungvögel an der A66 liegen jedoch ca. 2 g höher als in städtischen Biotopen.Störungen durch den Straßenverkehr, wie sie von anderen Autoren berichtet werden, ließen sich in unserem Untersuchungsgebiet nicht feststellen. In diesem Zusammenhang werden die geringe Störungsempfindlichkeit der Kohl- und Blaumeisen sowie der bisher geringe Verkehr auf der Autobahn diskutiert.
The impact of a motorway in construction and after opening to traffic on the breeding biology of Great Tit (Parus major) and Blue Tit (P. caeruleus)
Summary In February 1992, a study area (A 66) with 310 nestboxes was installed along the construction line of a four laned motorway between Steinau and Schlüchtern (5021'N, 0931'E). One area in the immediate neighbourhood (VG1) and one 5 km distant (VG2) from the study area at the motorway (see Fig. 1) served as controls for comparison. In all three areas, the nestboxes were checked weekly during the breeding season from the beginning of May until July. Species composition of the birds using nestboxes, rate of occupation of nestboxes, and, for Great Tits (Parus major) and Blue Tits (P. caeruleus), date of the first egg, clutch size, hatching rate and number of birds fledged were recorded. The study included 5 breeding seasons from 1992 to 1996, 3 years during the period of construction and 2 years after the opening of the motorway to traffic in December 1994. In 1996, the nestling weight of 20 broods of Great Tits at the A66 was recorded daily and compared with that of all nestlings in another study area (VG3, see Fig. 1).The data were analyzed separately for each year. Distributions of frequencies were analyzed with the x2 test, the other data with the Kruskal-Wallis-Test (H-Test). In case of significant differences between the study areas, the Mann Whitney U-test was used to determine which study area differed from the others. Nestlings bodymass was compared using the t-test.The species composition was similar in all three areas (Fig. 2), and it did not change after the opening of the motorway to traffic. The rate of occupation of the nestboxes, dates of laying of the first egg, clutch size, hatching rate and breeding success vary between years and between study areas (Table 1 to 5); data that differ significantly from those of two other areas are indicated by bold print. Such differences were observed in various years and involved all three areas. In study area A66, clutch size of Great Tits was higher in 1993; hatching success of Great Tits was lower in 1994 and that of Blue Tits was lower in 1993. However, there was no general trend that area A66 at the motorway was different from the other areas, either before or after being opened to the traffic. The weight of nestlings in study area A66 at the motorway was similar to that in comparable area nearby; only on day 12 and 13 after hatching was it slightly lower (Tab. 6). The last measurement on day 15 indicates a nestling weight of 16.2 g for the area at the motorway, which is in normal for deciduous forest habitats and approximately 2 g higher than that recorded in urban habitats.In brief, the motorway did not affect the species composition, rate of occupied nestboxes or the various breeding parameters; in particular, the moving traffic after opening did not seem to have any effect. The breeding parameters from the study area at the motorway were typical for the Schlüchtern region. Density reductions in breeding populations, as discussed by several authors, or disturbances caused by moving traffic, as previously reported, were not observed in our study. However, our key species, Great Tits and Blue Tits, are not generally very sensitive to interferences. Also, the level of traffic on the motorway was still rather low. This must be considered when our findings are generalized.
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