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61.
A large amount of overlap exists in the B‐mode ultrasound appearance of normal and abnormal liver, spleen, and kidney tissues in cats. Therefore, invasive tissue sampling procedures remain the standard method for diagnosing diseases in these organs. The purpose of our study was to assess the feasibility of ultrasound elastography as a technique for improving noninvasive characterization of the feline liver, spleen, and kidneys. Elastography was performed on 10 unsedated, clinically healthy cats. Numeric (strain) values (0 = softest to 255 = firmest) assigned to color pixels within regions of interest resulted in median scores (interquartile ranges) of body wall, 207.50 (189.75–224.00); liver, 119.00 (105.00–138.25); spleen, 127.50 (121–00–142.00); right renal cortex, 83.50 (64.00–130.00); right renal near field, 125.50 (110.75–139.75); left renal cortex, 77.50 (52.00–116.25); and left renal near field, 126.00 (114.00–145.25). Strain values were not different between organs. Body wall median was the only significantly different value (P < 0.05). Strain ratio values of body wall:organ were as follows: liver, 1.76 (1.38–2.00); spleen, 1.68 (1.47–1.83); right renal cortex, 2.31 (1.61–3.15); right renal near field, 1.62 (1.41–2.01); left renal cortex, 2.66 (1.45–4.13); and left renal near field, 1.51 (1.29–1.89). Subjectively, hepatic and splenic parenchymal tissues were homogeneous in compressibility and similar in elasticity to one another. Renal cortical tissue was softer compared to medullary tissue. Findings indicated that ultrasound elastography is a feasible technique for objectively and subjectively characterizing the feline liver, spleen, and kidneys. Further research is needed in cats with confirmed diseases of these organs, to compare the diagnostic sensitivity of ultrasound elastography vs. B‐mode ultrasonography.  相似文献   
62.
Because the prevailing form of hormone replacement therapy is associated with the development of cancer in breast and endometrial tissues, alternatives are needed for the management of menopausal symptoms. Formulations of Trifolium pratense L. (red clover) are being used to alleviate menopause-associated hot flashes but have shown mixed results in clinical trials. The strobiles of Humulus lupulusL. (hops) have been reported to contain the prenylflavanone, 8-prenylnaringenin (8-PN), as the most estrogenic constituent, and this was confirmed using an estrogen receptor ligand screening assay utilizing ultrafiltration mass spectrometry. Extracts of hops and red clover and their individual constituents including 8-PN, 6-prenylnaringenin (6-PN), isoxanthohumol (IX), and xanthohumol (XN) from hops and daidzein, formononetin, biochanin A, and genistein from red clover were compared using a variety of in vitro estrogenic assays. The IC50 values for the estrogen receptor alpha and beta binding assays were 15 and 27 microg/mL, respectively, for hops and 18.0 and 2.0 microg/mL, respectively, for the red clover extract. Both of the extracts, genistein, and 8-PN activated the estrogen response element (ERE) in Ishikawa cells while the extracts, biochanin A, genistein, and 8-PN, significantly induced ERE-luciferase expression in MCF-7 cells. Hop and red clover extracts as well as 8-PN up-regulated progesterone receptor (PR) mRNA in the Ishikawa cell line. In the MCF-7 cell line, PR mRNA was significantly up-regulated by the extracts, biochanin A, genistein, 8-PN, and IX. The two extracts had EC50 values of 1.1 and 1.9 microg/mL, respectively, in the alkaline phosphatase induction assay. On the basis of these data, hops and red clover could be attractive for the development as herbal dietary supplements to alleviate menopause-associated symptoms.  相似文献   
63.
The roots/rhizomes of Cimicifuga racemosa L. (Nutt.) (black cohosh) have traditionally been used to treat menopausal symptoms through an unknown mechanism of action. In an effort to determine if black cohosh had additional health benefits, methanol extracts were investigated for their potential to scavenge reactive oxygen species and to protect against menadione-induced DNA damage. These extracts effectively scavenged 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. In addition, the extracts showed dose-dependent decreases in DNA single-strand breaks and oxidized bases induced by the quinone menadione using the comet (single-cell gel electrophoresis assay) and fragment length associated repair enzyme assays, respectively. Bioassay-directed fractionation of the methanolic extracts using the DPPH assay as a monitor led to the isolation of nine antioxidant active compounds: caffeic acid (1), methyl caffeate (2), ferulic acid (3), isoferulic acid (4), fukinolic acid (5), cimicifugic acid A (6), cimicifugic acid B (7), cimicifugic acid F (8), cimiracemate A (9), and cimiracemate B (10). Six of these antioxidants were found to reduce menadione-induced DNA damage in cultured S30 breast cancer cells with the following order of potency: methyl caffeate (2) > caffeic acid (1) > ferulic acid (3) > cimiracemate A (9) > cimiracemate B (10) > fukinolic acid (5). These data suggest that black cohosh can protect against cellular DNA damage caused by reactive oxygen species by acting as antioxidants.  相似文献   
64.
I apply a comparative, functional group approach to coastal sandplain grassland taxa in order to examine whether rare plant species share certain aspects of rarity and life history characters that are distinct from their more common, co-occurring congeners in these habitats. I compiled a comparative data set containing 16 variables describing biogeographic distributions, level of imperilment, habitat specialization, vegetative versus sexual reproduction, seed dispersal, and dormancy of 27 closely-related pairs of plant species that contrast in their abundance (infrequent versus common) in coastal sandplain grasslands. Frequent and infrequent species were paired within genera (or closely related genera) and thus distributed equivalently across families to control for phylogenetic bias. Paired comparisons revealed that infrequent species were intrinsically rarer range-wide, and exhibited a narrower range and more habitat specialization than their common relatives. A classification tree distinguished infrequent species from common species on the basis of higher habitat specialization, larger seed size, smaller plant height, less reliance less on vegetative (colonial) reproduction, and tendency toward annual or biennial life history. Research and management steps to reduce competition from larger-satured, colonial, perennial species are recommended for these infrequent species. Basic research involving more species and more data on ecophysiological characters, demography, and competitive interactions are needed to identify critical life history traits that will influence responses to particular management regimes.  相似文献   
65.
The performance of a clinical trial for pharmaceutical agents is usually undertaken only after there is likely benefit demonstrated from the use of the putative agent. The consideration of botanical products as pharmaceutical agents must similarly go through a rigorous evaluation process. The present work reviews the recently published phase II study evaluating the effectiveness of black cohosh and red clover in a randomized trial with conjugated equine estradiol/medroxyprogesterone acetate and placebo for the treatment of menopausal symptoms. We analyze the possible reasons why this study failed to show benefit for either botanical product in reducing menopause-related vasomotor symptoms.  相似文献   
66.
Two metyrapone analogues, 2-(l-imidazolyl)-2-methyl-l-phenyl-l-pro-panone (A-phenyl-B-imidazolyl-metyrapone; III) and 2-methyl-l-phenyl-2-{1,2,4-triazol-l-yl)-l -propanone (A-phenyl-B-triazolyl-meiyrapone; IV) as well as two cyclopropylamine derivatives. N-cyclopropyl-4-icrt-butylbenzylamine (V) and N-cyclopropyl-4-(3,7-dimethyl-7-methoxy-octyloxy)benzamide (cyclopropylamine acylated with a JH analogue acid of known structure; VI) were synthesized and evaluated in biological assays for JH biosynthesis on cockroach, Diploptera punctata corpora allata and egg growth in adult cockroach as well as for mixed function oxidase activities, i.e. epoxidation of aldrin to dieldrin and O-demethylation of 7-methoxy-4-methylcoumarin to 7-hydroxy-4-methylcoumarin on microsomes from housefly, Musca domestica, abdomen and from cockroach midgut. Compound VI was a good in-vitro inhibitor of JH biosynthesis, but it had significantly lower activities in the assays for inhibition of microsomal cytochrome P-450. Compound IV and metyrapone had moderate activity as inhibitors of oocyte growth. Compounds III, IV and V were more potent inhibitors of housefly aldrin epoxidation than metyrapone and they inhibited the enzyme activity by almost 100% at 02mM, while in cockroach midgut microsome assay metyrapone was more potent than these three compounds.  相似文献   
67.
A 14‐year‐old Thoroughbred gelding was presented for chronic colic and weight loss. Transcutaneous and transrectal abdominal ultrasonography revealed distended, thickened small intestine with primary thickening of the muscularis and a focally more thickened loop with an echoic structure crossing the wall from the mucosa to the serosa. Visualization of diffuse thickening of the muscularis (muscular hypertrophy of the small intestine) and a focal lesion (pseudodiverticulum) helped clinicians make informed decisions. This case illustrates the importance of transabdominal and transrectal ultrasonography in horses with chronic colic and the relevance of considering the abnormalities in layering pattern of the intestinal wall.  相似文献   
68.
Eight botanical preparations that are commonly used for the treatment of menopausal symptoms were tested for estrogenic activity. Methanol extracts of red clover (Trifolium pratense L.), chasteberry (Vitex agnus-castus L.), and hops (Humulus lupulus L.) showed significant competitive binding to estrogen receptors alpha (ER alpha) and beta (ER beta). With cultured Ishikawa (endometrial) cells, red clover and hops exhibited estrogenic activity as indicated by induction of alkaline phosphatase (AP) activity and up-regulation of progesterone receptor (PR) mRNA. Chasteberry also stimulated PR expression, but no induction of AP activity was observed. In S30 breast cancer cells, pS2 (presenelin-2), another estrogen-inducible gene, was up-regulated in the presence of red clover, hops, and chasteberry. Interestingly, extracts of Asian ginseng (Panax ginseng C.A. Meyer) and North American ginseng (Panax quinquefolius L.) induced pS2 mRNA expression in S30 cells, but no significant ER binding affinity, AP induction, or PR expression was noted in Ishikawa cells. Dong quai [Angelica sinensis (Oliv.) Diels] and licorice (Glycyrrhiza glabra L.) showed only weak ER binding and PR and pS2 mRNA induction. Black cohosh [Cimicifuga racemosa (L.) Nutt.] showed no activity in any of the above in vitro assays. Bioassay-guided isolation utilizing ER competitive binding as a monitor and screening using ultrafiltration LC-MS revealed that genistein was the most active component of red clover. Consistent with this observation, genistein was found to be the most effective of four red clover isoflavones tested in the above in vitro assays. Therefore, estrogenic components of plant extracts can be identified using assays for estrogenic activity along with screening and identification of the active components using ultrafiltration LC-MS. These data suggest a potential use for some dietary supplements, ingested by human beings, in the treatment of menopausal symptoms.  相似文献   
69.
Identification of geranylgeranyl-modified proteins in HeLa cells   总被引:20,自引:0,他引:20  
Previous studies have shown that animal cells contain isoprenoid-modified proteins and that one of these proteins, lamin B, contains a thioether-linked farnesyl group that is attached to cysteine. In the present study, a novel isoprenoid-modification was identified by labeling HeLa cells with [3H]mevalonic acid and analyzing proteolytic digests of the total cell protein. Radioactive fragments were purified from these digests and treated with Raney nickel. The released, labeled material was analyzed by gas-liquid chromatography (GC) and mass spectrometry (MS). This approach revealed that an all-trans geranylgeranyl group was a major isoprenoid modification.  相似文献   
70.
Two cytochrome P-450-containing fractions were isolated from detergent-solubilized house fly microsomes by hydrophobic chromatography on a tryptamine-Sepharose gel. These fractions (designated P-450-1 and P-450-2) were distinctive in their spectral characteristics and in their profiles following electrophoresis in the presence of sodium dodecyl sulfate. Both fractions exhibited NADPH-dependent epoxidase activity when reconstituted with purified house fly cytochrome P-450 reductase and phospholipid. The aldrin epoxidase activity of fraction P-450-1 was twice that of P-450-2 even though heptachlor epoxidase activity of the fractions was equivalent. O-Demethylase activity with 7-methoxy-4-methylcoumarin was detectable only in the P-450-2 fraction.  相似文献   
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