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1.
A single diethylstilbestrol (DES) injection (5 mg DES/100 g body wt) was administrated to several lots (three specimens each) of adult male quail (Coturnix coturnix japonica). The birds were sacrificed 24, 48, 72 and 96 hr after the DES injection. A significant increase in liver weight and a clear drop in the hemoglobin concentration were observed after 24 hr. Later, a progressive rise was observed in plasma iron, total iron binding capacity, plasma copper and the phosphoprotein (vitellogenin), which reached highest values after 96 hr. In the liver, the iron showed an initial increase (24 hr), due to a rise in non-ferritin iron followed by a progressive decrease. Ferritin iron increased slowly but was significantly higher after 96 hr. This experimental model on male quail suggests an estrogen response in birds that could be more general and uniform than in mammals.  相似文献   

2.
OBJECTIVE: To evaluate cell proliferation in clinically healthy oral mucosa exposed to smoking and alcohol carcinogens over a period of 24 months using the AgNOR staining technique. STUDY DESIGN: Sixty patients were initially evaluated: 17 were control individuals, 25 were smokers and 18 were smokers and alcohol drinkers. Fifty-two of these patients were reevaluated. Specimens for cytology were obtained from swabs of lower lip mucosa, border of the tongue and floor of the mouth and underwent AgNOR staining for evaluation of mean number and mean area of AgNOR dots per nucleus and percentage of nuclei with > 3 and > 5 AgNOR dots. Student t and Kruskal-Wallis tests were used to compare values obtained. RESULTS: A statistically significant increase was found in mean number of AgNOR dots per nucleus in 2 groups. One group showed a tendency toward increase of these values. The results of the longitudinal evaluation (Kruskal-Wallis test) revealed a statistically significant difference in number and area of AgNOR dots in the cells of the lower lip. CONCLUSION: The increase of the variables suggests that the longitudinal evaluation of changes in cell proliferation in individuals exposed to smoking and alcohol carcinogens may be a useful monitoring tool.  相似文献   

3.
OBJECTIVE: To differentiate hyperplastic nodules (HPN), follicular adenoma (FA) and follicular carcinoma (FCA) of the thyroid by cytomorphologic features combined with argyrophilic nucleolar organizer regions (AgNORs) and Ki-67 proliferative markers on fine needle aspiration cytology. STUDY DESIGN: Cytomorphologic patterns, along with two proliferation markers, Ki-67 and AgNORs, in fine needle aspirates of 123 histologically confirmed cases of thyroid follicular lesions, including 39 hyperplastic nodules, 70 follicular adenomas and 14 cases of follicular carcinomas, were recorded. RESULTS: Mean AgNOR (mAgNOR) counts and Ki-67 labelling index (LI) were consistently higher in FCA in comparison to FA and HPN irrespective of the cytologic patterns in fine needle aspiration smears. Between benign and malignant lesions, an overlap of 1.83% at the cutoff point of 4.0 was observed in cases of mAgNORs, whereas it was 11.09% at a cutoff of 5.0 in cases of Ki-67 LI. CONCLUSION: mAgNOR counting in fine needle aspiration smears is more sensitive, simple and cost effective as compared to Ki-67 LI for differentiating between benign and malignant thyroid follicular neoplasms.  相似文献   

4.
Survival of Trichomonas gallinae was examined in white-winged dove (Zenaida asiatica) carcasses to assess whether birds that have been dead up to 8 hr can be sampled reliably for this protozoan. Carcasses of 100 T. gallinae-positive white-winged doves were separated into four groups of 25 birds, representing 2, 4, 6, and 8 hr post mortem sampling intervals and placed into an environmental chamber maintained at 27 C and 75% relative humidity. Live T. gallinae were isolated in 96, 100, 100, and 92% of the carcasses at each of the respective post mortem intervals. The experiment was repeated with another 100 carcasses of T. gallinae-positive white-winged doves placed in the environmental chamber, this time maintained at 27 C and 40% relative humidity. Live T. gallinae occurred in 96, 100, 96, and 100% of the carcasses at each of the respective post mortem intervals. Across both trials, the overall ability to detect positive birds from sampling carcasses up to 8 hrs post mortem was 97%. An a posteriori experiment was conducted in which 23 and 18 carcasses from the second trial were maintained in the environmental chamber at 27 C and 40% relative humidity and resampled at 24 and 48 hr post mortem, respectively. Live trichomonads were isolated from 91 and 44% of the carcasses at 24 and 48 hr, respectively. Results suggest live T. gallinae can be obtained from dove carcasses reliably up to 8 hr and possibly up to 24 hr after host death. The ability for T. gallinae to survive within this time interval can aid wildlife personnel in monitoring this protozoan at hunter check stations or obtaining samples from recently killed birds.  相似文献   

5.
1. Exogenous oestrogen administration to immature male and female chickens significantly increased plasma biotin and significantly reduced liver biotin concentrations. 2. The elevation in plasma biotin concentrations was dose dependent and maximum values were observed 48 hr after a single injection of oestrogen. 3. A second oestrogen injection significantly increased plasma biotin concentrations compared with values obtained after the initial injection given 10 days previously. 4. Plasma biotin concentrations were significantly increased in female, but not male, birds approaching sexual maturity. This increase coincided with the time of the known surge in endogenous oestrogen production by the developing ovary.  相似文献   

6.
We have characterized the meiosis of Olla v-nigrum by standard analysis, performed a NOR study using NOR banding, FISH of rDNA genes and sequential FISH/AgNOR analysis, and adapted the FISH methodology to Coccinellidae. The chromosome number determined at metaphase I was n = 9 + Xyp. At zygotene it was possible to identify the sex vesicle which presented a deeply stained heteropycnotic block. Chromosome X is much larger than the y and the two combine, forming a "parachute" in metaphase I. FISH analysis using a probe of rDNA genes 18S, 28S and 5.8S of D. melanogaster was used to map the genes in the sex vesicle. The NOR band showed high gene activity in this region. These results were confirmed using sequential FISH/Ag NOR analysis. The data obtained for Olla v-nigrum agree with the classical hypothesis raised to explain the type of sex chromosome association in a parachute format (Xyp) as being due to the presence of nucleolar material. The chromosome number and parachute configuration during metaphase I in this species agree with the basic karyotype of most Coleopterans. The major adaptation of the FISH method was the simultaneous denaturation and hybridization that permitted preservation of chromosome morphology, an essential factor when the chromosomes are small.  相似文献   

7.
The same total dose (1.2 g/kg/week) of 2,5-hexanedione (2,5-HD) was administered subcutaneously at 100 mg/kg/12 hr, 200 mg/kg/24 hr, and 400 mg/kg/48 hr to three groups of Donryu rats. The peripheral neuropathy induced by 2,5-HD was confirmed by clinical observation every day, and neurophysiological measurements every 4 weeks. During the 15th week of this experiment, 2,5-HD concentrations in plasma 0.5 to 24 hours after injection were determined. It was found that the greater the dose of 2,5-HD per treatment injected, the earlier peripheral neuropathy developed. Toxicokinetic analysis showed that both the values of the area under the plasma concentration versus time curve and the half life of 2,5-HD were increased, but the excretion parameters (Ke) were decreased, in animals treated with 200 mg/kg/24 hr and 400 mg/kg/48 hr 2,5-HD.  相似文献   

8.
Oral administration of E-5842, a new sigma1 receptor ligand being developed as an antipsychotic drug, to male mice at single doses of 50, 100, 200 and 400 mg/kg produced marked and sustained decreases in rectal temperature. Both the intensity and the duration of the hypothermic effect increased with dose. Maximum decreases from the mean pre-administration temperature (36.2 degrees C) ranged from 7.5 to 12.9 degrees C for animals receiving 50 and 400 mg/kg doses, respectively. Examination of bone-marrow smears obtained 24, 48 and 72 h after administration revealed a slight but statistically significant (p < 0.05) increase in the frequency of micronucleated polychromatic erythrocytes (MNPCE) at the 48 h sampling for animals receiving the 200 mg/kg dose. These animals showed decreases from pre-administration temperature of approximately 12 degrees C, with recovery being observed 24 h after administration. When the hypothermic effect of E-5842 administration was avoided by housing treated animals under conditions of increased environmental temperature (30 degrees C) for 24 h, MNPCE frequency reverted to vehicle control values. Further, in E-5842-treated animals with an increased MNPCE frequency there was a shift in the distribution of the relative areas of micronuclei in MNPCE towards higher values. In addition, there was a statistically significant increase (p < 0.001) in the number of relatively large micronuclei (micronucleus diameter > or = 1/4 cytoplasm diameter) similar to that produced by administration of the mitotic spindle inhibitor colchicine (1 mg/kg), suggesting disturbance of mitotic apparatus as the possible underlying mechanism. The results suggest that the slight increase in MNPCE frequency observed 48 h after administration of a 200 mg/kg dose of E-5842 is due to a hypothermic effect and not to a direct effect of E-5842 on DNA.  相似文献   

9.
Response of a transplantable tumor, S180, grown intradermally in inbred Balb/c mice, was assessed by using micronucleus assay after treating the solid tumors with bleomycin (BLM), radiation (RT) and hyperthermia (HT) vis-a-vis multimodality approach. The frequency of micronuclei (MN) though did not vary greatly during the one week of observation in untreated tumors, it significantly increased in the drug and RT groups at 24 hr post-treatment. However, MN frequency was non-significant in the HT group from the control. A drug dose dependent linear increase in the frequency of MN induction was evident in 10, 15 and 20 mg/kg body weight BLM alone treated groups. Combination of radiation with BLM or HT further increased the MN counts in the bimodality groups. But, MN induction at 24 hr post-treatment in the trimodality group (BLM + RT + HT) was non-significant from that of the bimodality treatments. However, the tumors treated with trimodality treatment presented severe tumor necrosis, indicating increased cell loss, and resulting in immediate tumor regression. In all the bi-modality groups MN counts though declined 3 or 5 days post-treatment, the values remained significantly higher than the control, on day 7 post-treatment. Micronucleus assay could be used as a predictive parameter for the assessment of post-irradiation tumor regression response. However, the tumor response assessment with MN assay alone may not be sufficient and the role of other parameters, such as apoptosis and necrosis, in immediate tumor regression, especially radiosensitive/thermosensitive tumors can not be ignored while taking multimodality approach into consideration for cancer therapy.  相似文献   

10.
Abstract

Argyrophilic nucleolar organizing region (AgNORs) associated proteins are important for cell proliferation and various diseases. We investigated AgNOR protein synthesis in hair root cells of males and females at different ages using two-dimensional image analysis. Experiments were performed on 58 healthy male and 24 healthy female volunteers in three groups according to age and sex. Hair root cells obtained from hair follicles were stained with silver. Total AgNOR number/total nuclear number (TAN/TNN) and total AgNOR area/nuclear area (TAA/NA) for each nucleus were analyzed. The only significant difference was observed in TAA/NA values for males and females from 6 to 12 years old. We suggest that the difference is due to high NOR activity caused by increased growth hormone production in hair root cells.  相似文献   

11.
During the formation of polytene chromosomes in salivary glands of Drosophila hydei, the genes for ribosomal RNA (rDNA) are underreplicated relative to the rest of the genome. We have measured the number of rRNA genes with and without intervening sequences (ivs+ and ivs- genes) in polytene chromosomes of different genotypes. In the group of genotypes having a large number of ivs- rRNA genes polytenization only occurs within the cluster of ivs- genes. In each of these genotypes rDNA polytenization reaches a constant level of 150 ivs- genes per two chromatid sets (2C); X/X constitutions having two nucleolus organizers (NOs) in the diploid set polytenize the same amount of rDNA as X/O constitutions. In the group of genotypes with small ivs- gene numbers, the rDNA region involved in polytenization is longer and has an average length of 1,700 kb per NO, which is constant in these genotypes. Polytenization of rDNA is extended into the cluster of ivs+ genes, in spite of the fact that these genes appear to be nonfunctional. The smaller the number of ivs- genes, the greater the number of ivs+ genes that are polytenized in the NO. In these genotypes, X/X females replicate twice as much rDNA as X/O males, suggesting that both NOs of the diploid set are polytenized. A comparison of the pattern of spacer length heterogeneity in hybrids between different stocks also demonstrates that both NOs are replicated during polytenization.  相似文献   

12.
Several physiological and biochemical changes which occur in CD-1 pathogen-free mice during the course of infection with Listeria monocytogenes strain A4413 have been examined. Mice injected with 10(4) to 10(6) organisms by the intraperitoneal route displayed a significant depression in weight gain. In contrast, at 24 hr after infection an increment in total liver weight averaging 0.1 g was observed. The ratios of liver to body weight increased throughout the observation period. As the severity of the infection increased, food intake, as well as total liver protein and nitrogen, showed a corresponding decrease, with the diminution being most evident immediately prior to the death of the animals. Blood urea nitrogen remained relatively constant for 24 hr and then increased continuously as the infection progressed to the acute stage. Total liver lipid increased until the death of the animals. At 72 hr postinfection, a significant decrease in oxidative phosphorylation was observed. Xanthine dehydrogenase activity increased, with maximal values obtained 72 hr after infection. Uric acid levels remained constant for 24 hr, diminished at 48 hr, and then increased until the death of the animals. After 24 hr, uricase activity showed a slight increase. This activity returned to within normal ranges at 48 hr and decreased as the infection progressed to the acute stage at 72 hr. The results support the hypothesis that at least a part of the cause of death is a derangement in hepatic purine and carbohydrate metabolism. The data are also consistent with the possibility of changes in iron transport in the infected mice.  相似文献   

13.
OBJECTIVE: To investigate the diagnostic value of AgNOR counts in cervical smears in the process of cervical carcinogenesis and in discriminating the different grades of squamous intraepithelial lesion (SIL). STUDY DESIGN: Silver nitrate staining for AgNOR counts was performed in 50 cervical smears of cytologically diagnosed normal, inflammatory, low grade SIL (LSIL) (mild dysplasia), high grade SIL (HSIL) (moderate and severe dysplasia) and squamous cell carcinoma. The smears were derived from the ongoing routine outpatient cytology screening at Queen Mary's Hospital, Lucknow, India. RESULTS: In normal and inflammatory smears, the number of AgNOR dots varied from 1 to 2, in mild dysplasia from 2 to 4, in moderate dysplasia from 4 to 6 and in severe dysplasia from 6 to 8. Frank cervical carcinoma cases revealed 8-10 dots. Thus, a progressive increase in AgNOR counts was observed when the severity of pathologic lesions increased. Statistical analysis revealed a significant difference in AgNOR counts between normal and inflammatory smears, but it was highly significant between inflammatory and LSIL cases, between LSIL and HSIL, and between severe dysplasia and frank malignancy. CONCLUSION: This study underscored the diagnostic importance of AgNOR counts, especially in discriminating between LSIL and HSIL of the cervix. Another study is under way to assess the potentiality of AgNOR counts as tumor markers in cervical carcinogenesis.  相似文献   

14.
In order to understand the mechanisms of intestinal injuries due to ionizing radiation, various groups of rats have been whole-body irradiated by gamma-rays at two dose rates (1 Gy/min and 1 Gy/hr), three doses (1, 2 and 4 Gy) and two post-irradiation times (24 and 48 hr). Duodenum samples of the animals were prepared for light microscopy, according to classical methods for histology and TUNEL reaction. A small number of morphological differences were observed within the mucosa between the two dose rates used. The extent and the number of lesions were more important at the slower dose rate (1 Gy/hr) and increased with the total dose. Clear cavities were seen inside the lamina propria which appeared like capillaries free of blood cells. The mitotic index calculated from crypt cells showed a regular decrease with the dose, which was exacerbated at 48 hr post-irradiation. On the other hand, the apoptotic index increased with the dose and the postirradiation time. Our results lead to hypothesize another mechanism of intestinal mucosa renewal allowing to explain mucosa denudations observed after radiotherapy. Thus we propose a new concept in which the duodenal mucosa renewal may occur by whole villi shedding into the duodenal lumen.  相似文献   

15.
In the present study, a lethal model of pulmonary candidiasis was established using granulocytopenic mice with cyclophosphamide. These mice started to die 1 day after infection and had all died within the next 48 hr. The counts of live C. albicans in the lung gradually increased with time, while the organisms were quickly eliminated in the normal mice. From the histology and measurements on bronchoalveolar lavage fluid (BALF), polymorphonuclear cells (PMN) response was almost zero up to 24 hr, and then a weak but significant response was observed at 48 hr, while a marked accumulation of PMN was detected from as early as 6 hr in normal mice. In contrast, macrophages had accumulated in BALF by 48 hr in granulocytopenic mice, but not in normal mice. Both in serum and BALF, a considerable level of tumor necrosis factor-α (TNF-α) was detected from 6 hr, peaking at 24 to 48 hr, while in normal mice the quantity was under the detection limit in serum and very low in BALF. The effects of administering granulocyte colony-stimulating factor (G-CSF) on these parameters were next examined. G-CSF significantly prolonged the survival time of granulocytopenic mice, promoted the clearance of organisms through increasing the counts of PMN in the lung, and strongly inhibited the production of TNF-α both in BALF and serum. These results suggest that this cytokine does not protect them, but plays some role in their death due to candidial infection in granulocytopenic mice.  相似文献   

16.
皮质酮对大鼠再生肝细胞转录活性的影响   总被引:7,自引:0,他引:7  
以AgNOR颗粒数为指标,研究大鼠部分肝切除后,皮质酮对余留肝细胞转录活性的影响。结果显示:部分肝切除后0~24h,各组肝细胞内(假手术、去肾上腺、去肾上腺 皮质酮)AgNOR颗粒数均下降;部分肝切除后36h,假手术鼠的AgNOR数目最多,到48h时已基本恢复到肝切除前水平;在部分肝切除后24~48h,去肾上腺鼠的AgNOR颗粒数持续升高;给去肾上腺鼠再注射剂量分别为10、20、40mg/kg体重的皮质酮,发现在36h和48h时,皮质酮剂量越高,AgNOR颗粒数日越少,且下降幅度越大。部分肝切除前12h给大鼠注射糖皮质激素受体颉颃剂——RU486(10mg/kg体重),结果与去肾上腺鼠相似。以上结果表明:皮质酮对部分肝切除后肝细胞的转录活性具有明显的抑制作用,而且是通过受体起作用,该作用表现在部分肝切除24h之后。  相似文献   

17.
The effect of X irradiation on the survival time of animals experimentally infected with pathogenic fungi was studied, and the activity of antifungal agents in pre-irradiated hosts was evaluated. A 24-hr preinfection dose of X irradiation decreased the survival time of mice infected with Cryptococcus neoformans and Histoplasma capsulatum to a greater extent than Candida albicans or Blastomyces dermatitidis infections. Exposure to 400 r caused a significant reduction in the variation (S(2)) survival time of C. albicans or H. capsulatum mouse infections. A single 100-mg/kg dose of 5-fluorocytosine or amphotericin B administered within 24 hr postinfection significantly extended the survival time of mice infected with C. albicans. Delayed treatment with amphotericin B was effective against C. neoformans infections. Four 50-mg/kg doses of 5-fluorocytosine were more effective than a single 200-mg/kg dose against C. neoformans infections. A single dose of amphotericin B provided significant protection when administered 48 hr postinfection against B. dermatitidis in preirradiated mice. A single dose of saramycetin 48 hr postinfection was highly effective against H. capsulatum mouse infections. A 100-mg/kg dose of amphotericin B was only effective against this fungal pathogen when administered within 8 hr postinfection. In vivo activity of the antifungal agents studied was detected within 8 to 14 days. The relative in vivo activity of several antifungal agents indicated the importance of considering their individual pharmacological properties for optimum effectiveness. The experimental model used in this study should be useful for the detection and for the preclinical evaluation of new antifungal agents.  相似文献   

18.
Phospholipase A1, A2, and C and diacylglycerol lipase activities were measured in cell sonicates after exposing confluent monolayers of porcine pulmonary artery endothelial cells to 5 ppm NO2, a toxic constituent of environmental pollution, for 24 and 48 hr. There was a significant increase (2.25-fold) in phospholipase A1 activity in 24 and 48 hr NO2-exposed cells, whereas activities of phospholipases A2 and C and diacylglycerol lipase were comparable to control cells at both time points. When endothelial cells were prelabeled with [3H]-arachidonic acid and then exposed to NO2 for 48 hr, increased counts were recovered from cell lysophospholipids with concomitant decreased recovery of counts from cell phosphatidylcholine and phosphatidylethanolamine. These results demonstrate that NO2 exposure results in specific activation of phospholipase A1.  相似文献   

19.
SYNOPSIS. Eight species representing 8 genera of gallinaceous birds were used: Alectoris graeca; Colinus virginianus; Coturnix coturnix; Gallus gallus; Meleagris gallopavo; Numidia meleagris; Pavo cristatus; Phasianus colchicus. Three-week-old birds were dosed with sporulated oocysts of Eimeria tenella Beltsville strain. At 4, 24, 48, 72, 96, 120, 144, and 168 hr after inoculation, 1-3 infected birds and uninoculated controls of each species were killed by cardiac exsanguination. Pieces of intestines were fixed and examined for stages of E. tenella as stained paraffin sections or indirect fluorescent antibody preparations. Oocyst counts were made in droppings collected for the first 6 days of the patent period. Sporozoites were found in the lamina propria of some birds of 5 species at 4 hr postinoculation, but no stages were found thereafter except in the breeds of G. gallus and A. graeca. At 144 and 168 hr postinoculation, a few macrogametes were found in the ceca of 2 A. graeca , but no oocysts were found in the feces. No statistical difference was found between the number of oocysts produced/bird in the breeds of G. gallus examined. It is evident from these observations that E. tenella did not complete its life cycle in several close phylogenetic relatives of G. gallus , even though in other studies this parasite was found to complete its life cycle in cell cultures derived from the same birds.  相似文献   

20.
Role of pili in the pathogenesis of Pseudomonas aeruginosa burn infection   总被引:9,自引:0,他引:9  
The present study using three isogenic mutants (F+P-, F-P+, F-P-) of Pseudomonas aeruginosa indicates that the presence of pili enhances the virulence of the organisms in experimental P. aeruginosa burn infection of mice. The 50% lethal dose (LD50) value for burned mice inoculated with non-piliated (P-) mutant was at least ten times higher than those inoculated with piliated (P+) bacteria. Meanwhile the LD50 value for burned mice inoculated with non-flagellated (F-) mutant was at least 10(5) times higher than those inoculated with flagellated (F+) bacteria. At 24 hr after inoculation, the bacterial counts in burned skin of mice inoculated with P+ bacteria were ten times higher than those inoculated with P- bacteria; and at 48 hr the bacterial counts became a hundred times higher in the former mice than the latter. At 24 hr after inoculation, P+ bacteria were isolated from blood, liver (F+P+), lung (F+P+), and kidney, while P- bacteria were not present in these tissues. And at 48 hr after inoculation, P+ bacteria were isolated from all tissues, while P- bacteria were isolated from some sites only. These results suggested that pili and flagella each play an important role as virulence factors independently, and that pili-mediated enhancement of virulence of P. aeruginosa was attributed to pili-mediated enhanced colonization of the organisms at the burned skin surfaces.  相似文献   

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