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The utility of high-resolution magnetic resonance (MR) imaging in studying a variety of intratesticular and extratesticular pathologic conditions was assessed. The high magnetic signal intensity of the testis provided an excellent background for visualization of intratesticular abnormalities. Except for old blood, all intratesticular processes were less intense than testis, especially on T2-weighted images. The visualization of the tunica albuginea is a distinct advantage, allowing its assessment in cases of trauma or testicular tumors. Epididymal and spermatic cord abnormalities were easily recognized. All pathologic conditions were best seen on T2-weighted images acquired in the coronal plane. Balanced images allowed for tissue characterization.  相似文献   
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Objective: To investigate the inhibitory effects against dengue virus serotype 2(DENV-2) by five different fractions(extracted by methanol, ethanol, benzene, chloroform and n-hexane) of Rumex dentatus, Commelina benghalensis, Ajuga bracteosa and Ziziphus mauritiana, as well as their constituents(gallic acid, emodin, and isovanillic acid). Methods: All the samples were tested for cytotoxicity on baby hamster kidney cells by MTT assay and for anti-DENV-2 activity by plaque reduction neutralization assay using two DENV-2 doses(45 and 90 plaqueforming units or PFU). Results: All the samples except isovanillic acid exhibited significant prophylactic effects against DENV-2 infectivity(without cytotoxicity) when administered to cells before infection, but were not effective when given 6 h post-infection. The methanol extract of Rumex dentatus demonstrated the highest antiviral efficacy by inhibiting DENV-2 replication, with IC_(50) of 0.154 μg/mL and 0.234 μg/mL, when added before infection with 45 and 90 PFU of virus, respectively. Gallic acid also exhibited significant antiviral effects by prophylactic treatment prior to virus adsorption on cells, with IC_(50) of 0.191 μg/mL and 0.522 μg/mL at 45 and 90 PFU of DENV-2 infection, respectively. Conclusions: The highly potent activities of the extracts and constituent compounds of these plants against DENV-2 infectivity highlight their potential as targets for further research to identify novel antiviral agents against dengue.  相似文献   
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Smith  TK; Lund  EK; Johnson  IT 《Carcinogenesis》1998,19(2):267-273
Glucosinolates are sulphur compounds that occur as glycosides in brassica vegetables. In response to tissue disruption they are degraded by thioglucosidase, releasing a range of highly reactive breakdown products, including the isothiocyanates, which we have previously shown to be selectively cytotoxic to undifferentiated colorectal tumour cells (HT29). In the present study we explored the effect of sinigrin on the intestinal mucosa of rats previously treated with dimethylhydrazine (DMH). In the first experiment, a semisynthetic feed containing sinigrin (400 microg/g diet) was provided 6 h after the second of two injections of DMH. The level of apoptosis was measured by morphological assessment of intact microdissected crypts obtained at 18, 24, 38, 48 and 72 h after injection, and compared with control groups given DMH only, or a sham-injection. Higher numbers of apoptotic nuclei were present in colonic tissue from both groups of DMH-treated rats compared with the controls, and the level was significantly higher in DMH- treated rats fed sinigrin compared with those given DMH only (P < 0.02). In a second experiment, rats were given sinigrin (400 microg/g diet) 22 h after the second of two injections of DMH; the level of apoptosis was measured after 48 h and the numbers of aberrant crypt foci (ACF) were measured after 42 days. The level of apoptosis was significantly higher in DMH-treated rats given sinigrin compared with controls (P < 0.05), and the numbers of ACF were significantly lower in sinigrin-treated rats (P < 0.001). There was no statistically significant induction of apoptosis in animals fed sinigrin alone. Sinigrin administered after DMH suppresses induction of ACF. This may be due to increased apoptotic deletion of damaged stem cells in the crypts of animals fed sinigrin.   相似文献   
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