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James S. Elliot 《The Western journal of medicine》1954,80(6):462-464
The early observations of Osborne, Mendel, and Ferry, and later of Higgins, showed that the incidence of urolithiasis was high in rats fed on diets deficient in fat soluble vitamins. Subsequently, the results of dark adaptation studies were interpreted as showing a relationship between vitamin A deficiency and calculous disease. However, a review of the literature including more recent data discloses that there is no evidence either clinical or experimental to support the claim that vitamin A deficiency is an etiologic factor in calculous disease in man in the United States. 相似文献
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Harry Steinberg 《The Western journal of medicine》1953,78(6):507
Otrivin,® a compound of the hydrochloride salt of phenyl-aminomethylimidazoline, was administered to 74 patients for varying periods as a nasal vasoconstrictor. Seventy-three had relief of nasal congestion for from five to six hours—longer periods than had been obtained with other vasoconstrictors they had used. No pressor effect was noted. 相似文献
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Zhan E McIntosh VJ Lasley RD 《American journal of physiology. Heart and circulatory physiology》2011,301(3):H1183-H1189
All four adenosine receptor subtypes have been shown to play a role in cardioprotection, and there is evidence that all four subtypes may be expressed in cardiomyocytes. There is also increasing evidence that optimal adenosine cardioprotection requires the activation of more than one receptor subtype. The purpose of this study was to determine whether adenosine A(2A) and/or A(2B) receptors modulate adenosine A(1) receptor-mediated cardioprotection. Isolated perfused hearts of wild-type (WT), A(2A) knockout (KO), and A(2B)KO mice, perfused at constant pressure and constant heart rate, underwent 30 min of global ischemia and 60 min of reperfusion. The adenosine A(1) receptor agonist N(6)-cyclohexyladenosine (CHA; 200 nM) was administrated 10 min before ischemia and for the first 10 min of reperfusion. Treatment with CHA significantly improved postischemic left ventricular developed pressure (74 ± 4% vs. 44 ± 4% of preischemic left ventricular developed pressure at 60 min of reperfusion) and reduced infarct size (30 ± 2% with CHA vs. 52 ± 5% in control) in WT hearts, effects that were blocked by the A(1) antagonist 8-cyclopentyl-1,3-dipropylxanthine (100 nM). Treatments with the A(2A) receptor agonist CGS-21680 (200 nM) and the A(2B) agonist BAY 60-6583 (200 nM) did not exert any beneficial effects. Deletion of adenosine A(2A) or A(2B) receptor subtypes did not alter ischemia-reperfusion injury, but CHA failed to exert a cardioprotective effect in hearts of mice from either KO group. These findings indicate that both adenosine A(2A) and A(2B) receptors are required for adenosine A(1) receptor-mediated cardioprotection, implicating a role for interactions among receptor subtypes. 相似文献
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《Bioscience, biotechnology, and biochemistry》2013,77(12):2606-2613
27-Oxomilbemycins A3 and A4 and 27-hydroxymilbemycins A3 and A4 were identified as metabolites in soil metabolism studies of milbemycins A3 and A4. Chemical derivation methods were developed to synthesize 27-oxomilbemycins A3 and A4 and 27-hydroxymilbemycins A3 and A4 from milbemycins A3 and A4. In addition, 27-alkoxymilbemycin derivatives were also synthesized from the same precursors. Some of the synthesized compounds displayed satisfactory acaricidal activity against the organophosphorus-sensitive two-spotted spider mite (Tetranychus urticae), but did not have superior activity to corresponding milbemycins A3 and A4. 相似文献
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赤霉素A4,A7的研究进展 总被引:7,自引:0,他引:7
赤霉素A_4、A_7的研究进展颜方贵,秦杰,何增国,李季伦(北京农业大学生物学院,北京100094)赤霉素A_3(GA_3)是目前应用最广的植物生长激素之一。随着研究的深入,对该族的其它同系物,特别是GA_4、GA_7越来越受到重视,这是由于GA_4... 相似文献
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Lovering RP 《Bioethics》2005,19(2):131-145
The traditional approach to the abortion debate revolves around numerous issues, such as whether the foetus is a person, whether the foetus has rights, and more. Don Marquis suggests that this traditional approach leads to a standoff and that the abortion debate 'requires a different strategy.' Hence his 'future of value' strategy, which is summarized as follows: (1) A normal foetus has a future of value. (2) Depriving a normal foetus of a future of value imposes a misfortune on it. (3) Imposing a misfortune on a normal foetus is prima facie wrong. (4) Therefore, depriving a normal foetus of a future of value is prima facie wrong. (5) Killing a normal foetus deprives it of a future value. (6) Therefore, killing a normal foetus is prima facie wrong. In this paper, I argue that Marquis's strategy is not different since it involves the concept of person--a concept deeply rooted in the traditional approach. Specifically, I argue that futures are valuable insofar as they are not only dominated by goods of consciousness, but are experienced by psychologically continuous persons. Moreover, I argue that his strategy is not sound since premise (1) is false. Specifically, I argue that a normal foetus, at least during the first trimester, is not a person. Thus, during that stage of development it is not capable of experiencing its future as a psychologically continuous person and, hence, it does not have a future of value. 相似文献
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初选藤仓赤霉菌(Gibberella fujikuroi)农大17菌株为赤霉素A_4、A_7(GA_4、GA_7)的生产菌,该菌株GA_(4+7)的积累量,除与营养条件有关外,温度和pH是极为重要的因子,随着发酵温度从28℃上升至32℃,GA_(4+7)的产量由21μg/ml增至81μg/ml,GA_3由702μg/ml降至328μg/ml。pH回调至中性,GA_(4+7)的产量由75μg/ml增至180μg/ml,GA_3由322μg/ml降至211μg/ml。此外,设法延长发酵周期也是增加GA_(4+7)的一个因素。综合上述条件,即发酵过程中,发酵液的pH由48h前的4回调并维持在6.7左右,温度由28℃上调并控制在32℃,摇瓶培养12天,GA_(4+7)的产量达890μg/ml,20—600L发酵罐发酵240h,GA_(4+7)产量达680μg/ml左右。GA_(4+7)浓度的测定亦作了简化处理,发酵液不经提取,可直接用硅胶板G薄层层析(TLC)后进行荧光比色,产品测定宜采用高效液相色谱法(HPLC)。按照上述条件培养的农大17菌株,产生GA_3、GA_7和GA_4的比例为23.131:16.105:31.258,GA_4高于有关报道。 相似文献
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O'Nuallain B Klyubin I Mc Donald JM Foster JS Welzel A Barry A Dykoski RK Cleary JP Gebbink MF Rowan MJ Walsh DM 《Journal of neurochemistry》2011,119(1):189-201
Diverse lines of evidence indicate that pre-fibrillar, diffusible assemblies of the amyloid β-protein (Aβ) play an important role in Alzheimer's disease pathogenesis. Although the precise molecular identity of these soluble toxins remains unsettled, recent experiments suggest that sodium dodecyl sulfate (SDS)-stable Aβ dimers may be the basic building blocks of Alzheimer's disease-associated synaptotoxic assemblies and as such present an attractive target for therapeutic intervention. In the absence of sufficient amounts of highly pure cerebral Aβ dimers, we have used synthetic disulfide cross-linked dimers (free of Aβ monomer or fibrils) to generate conformation-specific monoclonal antibodies. These dimers aggregate to form kinetically trapped protofibrils, but do not readily form fibrils. We identified two antibodies, 3C6 and 4B5, which preferentially bind assemblies formed from covalent Aβ dimers, but do not bind to Aβ monomer, amyloid precursor protein, or aggregates formed by other amyloidogenic proteins. Monoclonal antibody 3C6, but not an IgM isotype-matched control antibody, ameliorated the plasticity-disrupting effects of Aβ extracted from the aqueous phase of Alzheimer's disease brain, thus suggesting that 3C6 targets pathogenically relevant Aβ assemblies. These data prove the usefulness of covalent dimers and their assemblies as immunogens and recommend further investigation of the therapeutic and diagnostic utility of monoclonal antibodies raised to such assemblies. 相似文献