Cytotoxic dehydromonacolins from red yeast rice     

Zhu L  Yau LF  Lu JG  Zhu GY  Wang JR  Han QB  Hsiao WL  Jiang ZH 《Journal of agricultural and food chemistry》2012,60(4):934-939

Two new dehydromonacolins (1 and 3), together with nine known monacolins (4-12), were isolated from red yeast rice. Compounds 4-6 were isolated from a natural resource for the first time. Their structures were elucidated by means of NMR and mass spectroscopic analyses. The structure of dehydromonacolin N (1) was further confirmed by its semisynthesis from monacolin K (lovastatin) (11). Dehydromonacolin J (2), an intermediate in the semisynthesis of 1, was obtained as a new dehydromonacolin. The structure of dehydromonacolin L (3) was also confirmed by an elimination reaction of monacolin L (12). Compound 1, possessing a C2 side chain, is unprecedented in the natural monacolin family and exhibited moderate cytotoxic activity against Hep G2, Caco-2, and MCF-7 cancer cell lines. Dehydromonacolin K (8) demonstrated the most potent cytotoxicity to all three of these cell lines. The structure-activity relationship of natural and synthesized monacolins was discussed. This is the first report on the cytotoxic effects of dehydromonacolins.  相似文献   

Retrospective study on the occurrence of canine lymphoma and associated breed risks in a population of dogs in NSW (2001–2009)          下载免费PDF全文

PPY Yau  NK Dhand  PC Thomson  RM Taylor 《Australian veterinary journal》2017,95(5):149-155

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Parietal-eye phototransduction components and their potential evolutionary implications     

Su CY  Luo DG  Terakita A  Shichida Y  Liao HW  Kazmi MA  Sakmar TP  Yau KW 《Science (New York, N.Y.)》2006,311(5767):1617-1621

The parietal-eye photoreceptor is unique because it has two antagonistic light signaling pathways in the same cell-a hyperpolarizing pathway maximally sensitive to blue light and a depolarizing pathway maximally sensitive to green light. Here, we report the molecular components of these two pathways. We found two opsins in the same cell: the blue-sensitive pinopsin and a previously unidentified green-sensitive opsin, which we name parietopsin. Signaling components included gustducin-alpha and Galphao, but not rod or cone transducin-alpha. Single-cell recordings demonstrated that Go mediates the depolarizing response. Gustducin-alpha resembles transducin-alpha functionally and likely mediates the hyperpolarizing response. The parietopsin-Go signaling pair provides clues about how rod and cone phototransduction might have evolved.  相似文献   

Synthesis of ligand-specific phage-display ScFv against the herbicide picloram by direct cloning from hyperimmunized mouse     

Tout NL  Yau KY  Trevors JT  Lee H  Hall JC 《Journal of agricultural and food chemistry》2001,49(8):3628-3637

Immunoglobulin genes were directly isolated from the splenocytes of a BALB/C mouse hyperimmunized with the auxinic herbicide picloram conjugated to bovine serum albumin. Variable light and heavy domain DNA were joined to produce single-chain Fv (scFv) DNA, which was cloned into phage vector fd-tet-GIIID to display multiple copies of scFv on the filamentous phage minor coat protein gIIIp. The phage-display scFv library (10(4) clones) was selected against picloram conjugated to ovalbumin. After five rounds of panning, individual clones were analyzed. ScFv with different affinities to picloram (IC(50) values ranging from 20 ppb to 10 ppm) were detected in the final enriched pool. The increased avidity of the phage vector enhanced the selection (i.e., panning) of multiple picloram-specific recombinant antibodies. Stringent selection was required to isolate the clones with the highest affinity. Nucleotide sequence analysis of six isolated clones revealed that all of the V(L) belonged to the V kappa 9A family joined to J kappa 2 segments. All of the V(H) belonged to the V(H)()7183 family and joined to two different J segments (i.e., J(H)()2 or J(H)()4). Different from the immune response to large molecular weight molecules (MW > 10,000 Da), which requires both VDJ segment rearrangement and somatic hypermutations, production of high-affinity antibodies to picloram, a small ligand having a formula weight of 241.5 Da, predominantly requires somatic hypermutations.  相似文献   

Neuroinflammatory diseases of the central nervous system of dogs: A retrospective study of 207 cases (2008–2019)     

Jessica A. Elbert  Wilson Yau  Daniel R. Rissi 《The Canadian veterinary journal. La revue veterinaire canadienne》2022,63(2):178

In this study we describe 207 cases of neuroinflammatory diseases of the central nervous system (CNS) in dogs autopsied at the Athens Veterinary Diagnostic Laboratory (University of Georgia, United States) from 2008 to 2019. Idiopathic and infectious diseases were diagnosed in 111 cases (53.6%) and 96 cases (46.4%), respectively. Idiopathic diseases consisted of granulomatous meningoencephalomyelitis (n = 42; 37.8% of idiopathic cases), nonspecific lymphoplasmacytic meningoencephalomyelitis (n = 39; 35.1%), necrotizing meningoencephalomyelitis (n = 22; 19.8%), presumed steroid-responsive meningitis-arteritis (n = 6; 5.4%), and necrotizing leukoencephalitis (n = 2; 1.8%). Infectious diseases consisted of bacterial infections (n = 49; 51% of infectious cases), viral infections (n = 39; 40.6%), fungal infections (n = 5; 5.2%), and parasitic infections (n = 3; 3.1%). Our study provides an overview of the most frequent neuroinflammatory diseases of the CNS of dogs in our diagnostic routine; indicates that a comprehensive diagnostic approach, including a thorough evaluation of the pathology findings and ancillary laboratory testing results, is important for an adequate diagnosis of neurologic diseases in dogs; and underscores the problems associated with the variability in tissue sample collection methods among cases. The great number of nonspecific lymphoplasmacytic meningoencephalitis also highlights the need for development of molecular laboratory tests to identify potential infectious agents in these cases.  相似文献   

麻类科研单位产业开发的制约因素与对策     

孙进昌  罗艳  童华兵 《农产品加工．学刊》2007,(8):60-65

通过对麻类科研的公益性和商业性全面分析,阐述了麻类科研机构尚不能转为企业的理由。  相似文献   

Early Identification of Stable Transformation Events by Combined Use of Antibiotic Selection and Vital Detection of Green Fluorescent Protein (GFP) in Carrot (Daucus carota L.) Callus     

Yuan-Yeu Yau  Seth J Davis  Ahmet Ipek  Philipp W Simon 《中国农业科学(英文版)》2008,7(6)

Genetic transformation is a useful technique to complement conventional breeding in crop improvement. Although carrot has been a model organism for in vitro embryogenesis study, genetic transformation of carrot is still lengthy and labor intensive. An efficient transformation and detection system is desirable. Direct infection of Agrobacterium to carrot calli has provided an easy way for carrot genetic transformation. To improve the efficiency of antibiotic selection in this method, we report the combined use of an improved green-fluorescent protein, referred to as smGFP, to establish a versatile selection method for carrot callus transformation system. By combining antibiotic selection with the bright fluorescence observed in the callus tissue, we were able to easily identify stable transformants in early stage of the transformation process. In addition to the GFP expression of the callus cells, the transgenic nature of callus cells was confirmed with Southern and Western analysis. We found we can link the simplicity of carrot-callus-cell transformation, early detection of stable transformants with antibiotic selection, visualization of GFP fluorescence, and molecular analysis (Southern and Western) of callus tissue (non-photosynthetic tissue) to provide a more efficient way in identifying stable transformants at early stage of carrot transformation.  相似文献   

Early Identification of Stable Transformation Events by Combined Use of Antibiotic Selection and Vital Detection of Green Fluorescent Protein （GFP） in Carrot （Daucus carota L.） Callus     

Yuan-Yeu Yau  ;Seth J Davis  ;Ahmet Ipek  ;Philipp W Simon 《中国农业科学(英文版)》2008,7(6):664-671

Genetic transformation is a useful technique to complement conventional breeding in crop improvement. Although carrot has been a model organism for in vitro embryogenesis study, genetic transformation of carrot is still lengthy and labor intensive. An efficient transformation and detection system is desirable. Direct infection of Agrobacterium to carrot calli has provided an easy way for carrot genetic transformation. To improve the efficiency of antibiotic selection in this method, we report the combined use of an improved green-fluorescent protein, referred to as smGFP, to establish a versatile selection method for carrot callus transformation system. By combining antibiotic selection with the bright fluorescence observed in the callus tissue, we were able to easily identify stable transformants in early stage of the transformation process. In addition to the GFP expression of the callus cells, the transgenic nature of callus cells was confirmed with Southern and Western analysis. We found we can link the simplicity of carrot-callus-cell transformation, early detection of stable transformants with antibiotic selection, visualization of GFP fluorescence, and molecular analysis （Southern and Western） of callus tissue （non-photosynthetic tissue） to provide a more efficient way in identifying stable transformants at early stage of carrot transformation.  相似文献   

Protective effects of bilberry (Vaccinium myrtillus L.) extract on KBrO3-induced kidney damage in mice     

Bao L  Yao XS  Tsi D  Yau CC  Chia CS  Nagai H  Kurihara H 《Journal of agricultural and food chemistry》2008,56(2):420-425

Potassium bromate (KBrO3) is an oxidizing agent used as a food additive which causes kidney damage as a potent nephrotoxic agent, and the mechanism may be explained by the generation of oxygen free radicals. Our experiments showed that single intraperitoneal administration of 200 mg/kg KBrO3 could induce serious kidney damage, with an increase in serum blood urea nitrogen (BUN) and creatinine levels. Five-day oral administration of bilberry ( Vaccinium myrtillus L.) extract at 50, 100, and 200 mg/kg resulted in a reversal in serum BUN and creatinine to normal levels and decreased kidney malondialdehyde (MDA), nitric oxide (NO), and xanthine oxidase (XOD) levels. Also, bilberry extract improved oxygen radical absorbance capacity (ORAC) levels in kidney tissue, which showed that bilberry extract reduced the degree of oxidative stress and kidney damage induced by KBrO3. These findings demonstrate that the protective effect of bilberry extract is attributed to its free radical scavenging activity and lipid peroxidation inhibitory effect.  相似文献   

Protective effects of bilberry (Vaccinium myrtillus L.) extract on restraint stress-induced liver damage in mice     

Bao L  Yao XS  Yau CC  Tsi D  Chia CS  Nagai H  Kurihara H 《Journal of agricultural and food chemistry》2008,56(17):7803-7807

Our experiments showed that 18 h restraint stress could induce serious liver damage, with an increase in plasma alanine aminotransferase (ALT) level (107.68 +/- 3.19 U/L vs 18.08 +/- 1.46 U/L). Meanwhile, we observed increased malondialdehyde (MDA) levels and lowered oxygen radical absorbance capacity (ORAC) values in plasma and liver of restraint mice compared with starved mice. Bilberry extract (containing 42.04% anthocyanins) was oral administrated to mice at 50, 100, and 200 mg/(kg x day) for five days, which remarkably decreased plasma ALT level to 17.23 +/- 2.49 U/L at the dose of 200 mg/(kg x day) and thus alleviated stress-induced liver damage. In addition, bilberry extracts increased glutathione (GSH) and vitamin C levels and significantly decreased MDA and nitric oxide (NO) levels in the liver tissues. These results suggest that bilberry extract plays an important role in protecting against restraint stress-induced liver damage by both scavenging free radicals activity and lipid peroxidation inhibitory effect. This study showed the beneficial health effects of bilberry extract through its antioxidative action.  相似文献