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21.
DNA flow cytometry of endoscopically examined colorectal adenomas and adenocarcinomas 总被引:2,自引:0,他引:2
DNA ploidy of 64 colorectal adenomas and 49 adenocarcinomas, examined endoscopically, was studied by flow cytometry. We found DNA aneuploidy in none of the 105 normal mucosa samples (0%), in 20 adenomas (31%), and in 36 adenocarcinomas (74%). DNA ploidy of adenomas correlated with size (P = 0.02) and degree of dysplasia (P less than 0.01) but not with histologic type. Adenomas had a 45% incidence of DNA aneuploid stem lines in the DNA index range of 0.80-1.20, compared with 8% in the case of adenocarcinomas. The distribution of the DNA index values of adenocarcinomas was approximately normal, with a mean value 1.63 +/- 0.28. The mean DNA index for the three cases of "carcinoma in adenoma" with invasion of the stalk of the adenoma was 1.52 +/- 0.18. These results, using DNA flow cytometry, provide evidence for the progression of colorectal adenoma to adenocarcinoma. The classification of adenomas according to DNA ploidy may be information of considerable practical value to the clinician in predicting risk of further adenomas and/or risk of cancer. 相似文献
22.
Musch T. I.; Moore R. L.; Riedy M.; Burke P.; Zelis R.; Leo M. E.; Bruno A.; Bradford G. E. 《Journal of applied physiology》1988,64(3):1153-1159
The endurance capacities of rats with myocardial infarctions (MI) and of rats having undergone sham operations (SHAM) were tested during a submaximal exercise regimen that consisted of swimming to exhaustion. During this test, a decrement in the endurance capacity of the MI rat was demonstrated as the SHAM rat swam 25% longer than the MI rat (65 +/- 4 vs. 52 +/- 4 min). Glycogen concentrations were measured in the liver and the white gastrocnemius, plantaris, and soleus muscles of SHAM and MI rats that were randomly divided into four subgroups, which consisted of resting control, swim to exhaustion, swim to exhaustion + 24 h recovery, and swim to exhaustion + 24 h recovery + a second swim to exhaustion. The results demonstrated that the glycogen concentrations found in the liver, white gastrocnemius, plantaris, and soleus muscles of the SHAM and MI rats belonging to the resting control groups were similar. After swimming to exhaustion the glycogen concentrations in these tissues were significantly reduced compared with those found in the resting control groups of rats, and after 24 h of recovery the glycogen concentrations in these tissues were again similar to those found in the resting control groups of rats. Since the magnitude of the glycogen depletion in the liver and the white gastrocnemius, plantaris, and soleus muscles was similar in the SHAM and MI rats and because the SHAM rats consistently swam for longer periods of time in each of the experimental groups, it would be logical to assume that the rates of glycogen utilization for the various tissues may have been greater in the MI rat during exercise.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
23.
Protein synthetic activity and adenylate energy charge in Rhein-treated cultured human glioma cells. 总被引:1,自引:0,他引:1
A Delpino M G Paggi P F Gentile S Castiglione T Bruno M Benass A Floridi 《Cancer biochemistry biophysics》1992,12(4):241-252
The effect of Rhein (RH) on the protein synthetic activity and adenylate energy charge in human glioma cells cultured in vitro has been investigated. The results demonstrate that in RH-treated cells, the protein synthesis is strongly decreased, but no modifications in the qualitative pattern occur. The extent of inhibition is a function of the drug concentration as well as of the time of exposure. Such an inhibition must be ascribed mainly to a reduction of adenylate energy charge brought about by RH because of its effect on respiration and glycolysis. The correlation between the adenylate energy charge and cell viability, as well as the possibility of using rhein as a biochemical modulator to reduce or to reverse multidrug resistance, are also discussed. 相似文献
24.
Giuseppe Frenguelli Emma Bricchi Bruno Romano Gianfranco Mincigrucci Francesco Ferranti Evasio Antognozzi 《Aerobiologia》1992,8(3):415-418
Summary 7 years of airborne pollen monitoring in Perugia (central Italy) were used to determine the temperature requirements to break dormancy and to resume growth and bloom ofCorylus avellana L.,Corylus needs 1000 chill-units to complete its dormancy and this value, in the Perugian area, is met by the end of December or the first days of January. MoreoverCorylus trees require 220 growth degree hours before they are able to flower. If air temperature is high, this value can be achieved in only 10 days, but if the temperature remains too low, the heat accumulation can require up to 35 days. With these parameters it is possible to build a model to predict the date of the beginning ofCorylus avellana pollen season. 相似文献
25.
J G Bruno G B Olson 《Analytical and quantitative cytology and histology / the International Academy of Cytology [and] American Society of Cytology》1992,14(1):24-31
Retinoic acid (RA)-treated HL-60 cells subjected to density arrest (DA) and double thymidine block (TB) synchronization demonstrated image feature changes associated with cellular proliferation and differentiation. RA-treated TB cells demonstrated an increased level of morphologic differentiation (assessed by differential counts and quantitation of nuclear shape) and more rapid functional differentiation (assessed by superoxide production and expression of complement receptors) than RA-treated DA cells. By comparison to DA cells, TB cells had less variation in virtually all image features values. A Kruskal-Wallis test of image features ranked total optical density (TOD) of Feulgen-stained cells, nuclear area and shape factor as the top three features regardless of synchronization method. Statistically significant changes in image feature values of RA-treated cells were first noted on day 1. The computer-assisted ability to discriminate RA-treated cells on a given day after induction from paired controls by means of an unsupervised learning algorithm increased over a seven-day period for both DA and TB cells. However, in the dichotomous (RA-treated versus untreated) classification scheme employed, which did not account for continuous levels of morphologic differentiation, there was no advantage in the use of the TB over DA procedure. 相似文献
26.
27.
The iaaM and iaaH genes of Agrobacterium tumefaciens and Agrobacterium rhizogenes play an important role in crown gall and hairy root disease. The iaaM gene codes for tryptophan monooxygenase which converts tryptophan into indole-3-acetamide (IAM). IAM is converted into the auxin indole-3-acetic acid (IAA) by indoleacetamide hydrolase, encoded by the iaaH gene. In functional studies on the activity of the iaa genes of the TB region of the A. tumefaciens biotype III strain Tm4, the frequently used 35S--glucuronidase (35S-UidA or GUS) marker gene was found to inhibit IAA synthesis and root induction encoded by the TB iaa genes. To exert this inhibition, the 35S-UidA gene must be cotransferred with the iaaH gene. The 35S promoter alone is sufficient to cause the inhibitory effect. 相似文献
28.
Populations ofTococa occidentalis (Melastomataceae) and the inhabiting ants (Myrmelachista sp.) were observed for more than eight months in the Peruvian Amazon (Sira mountains). They represent a complex coevolutionary system: the plants offer shelter (leaf domatia, hollow stems) and food (leaf glands), whereas the ants kill all surrounding plants, including large trees up to 10 m, by chemical weapons. Experiments with exposed plants revealed a highly specialized way to attack meristematic tissue and leaf nervature, which leads to a quick decay of the plant individuals. The clearing of the vegetation by the ants allows theTococa population to expand mostly by vegetative shoots to large monocultures (up to 30 m in diameter) free from any other plant species. Artificially introduced plant individuals, from differentT. occidentalis populations, are regarded as a foreign species by the ants.The succession of such aTococa-Myrmelachista system begins with one or a few founder plants on a light place in the midst of the vegetation.Myrmelachista soon inhabits their host plants which otherwise would not survive and begin to clear the place from all foreign plant species.Tococa expands quickly, forming circle shaped populations. Distantly situated canopy trees shade theTococa population after a number of years and cause their decay. The whole place appears contaminated for years and no other plant can establish itself. Some of the consequences of these open places are erosion and a severe influence on the regeneration of the forest. 相似文献
29.
Egg production rates in wild populations of Acartia clausi and Centropages typicus, sampled biweekly in the Gulf of Naples from October 1985 to July 1987, showed marked seasonal fluctuations with maximum values in early spring that proceeded the annual maxima for adult female densities in summer. A positive correlation between chlorophyll a concentrations and egg production was evident only during the early spring phytoplankton bloom. A strong diminution in egg deposition occurred later in spring and continued throughout the summer notwithstanding high chlorophyll concentrations. In winter, when population abundances for adult females were lowest, egg production rates were always higher than in summer. Differences in egg production rates coincided with pronounced morphological changes between summer and winter populations of both species. The most striking of these changes consisted, in winter, in the presence of a dark brown fluid-like mass of granular material that seemed to freely bathe the gonads. The presence of this substance only during periods of elevated egg production suggests that it may enhance egg production rates when the adult population reaches minimum annual levels. Such a mechanism of self-regulation may operate to dampen the effects of environmental variability thereby contributing to maintain a conservative structure in coastal copepod communities. 相似文献
30.
Summary A method for the isolation of brush-border membranes of large intestinal epithelial cells was developed, which is based on the purification of intact brush-border caps by Percoll® density-gradient centrifugation followed by separation of the vesiculated brush-border membranes on sucrose gradients. The procedure has two major advantages in comparison to known methods: 1) its first step does not depend on the determination of marker enzymes and 2) the method is applicable to rats as well as rabbits without major modifications. Due to the lack of an accepted marker for the colonic brush-border membrane the validity of the isolation procedure was tested by its application to the small intestine. Rat small intestinal brush-border membranes were enriched 21-fold when compared to the homogenate. The method was used to evaluate alkaline phosphatase as a marker enzyme for the colonic brush-border membrane. The results suggest that alkaline phosphatase is not exclusively localized in the brush-border membrane since this enzyme was also associated with membranes having different physical properties. 相似文献