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41.
The virulence of different isolates of Mycobacterium has been associated with two morphologically distinguishable colonial variants: opaque (SmOp) and transparent (SmTr). In this report we used an in vitro assay to compare macrophage (Mphi) responses to SmOp and SmTr Mycobacterium fortuitum variants, taking advantage of the fact that these variants were derived from the same isolate. Cells preactivated or not with gamma interferon (IFN-gamma) were infected with SmOp or SmTr M. fortuitum. We showed that SmOp and SmTr induced different levels of nitric oxide (NO) production by IFN-gamma-stimulated Mphi. Indeed, the amount of IFN-gamma-induced NO production by J774 cells was 4.8 to 9.0 times higher by SmOp (23.1 to 37.7 micro M) compared to SmTr infection (3.9 to 4.8 micro M) (P = 0.0332), indicating that virulent SmTr bacilli restricted NO production. In addition, IFN-gamma-induced NO production by Mphi was higher when correlated with reduction of only avirulent SmOp bacillus viability. SNAP (S-nitroso-N-acetyl-DL-penicillamine)-induced NO production did not modify SmTr viability, indicating its resistance to nitrogen radicals. Electron microscopy studies were performed to evaluate the capacity of phagosomes to fuse with lysosomes labeled with bovine serum albumin-colloidal gold particles. By 24 h postinfection, 69% more phagosome-containing SmOp variant had fused with lysosomes compared to the SmTr-induced phagosomes. In conclusion, these data indicate that virulent SmTr bacilli may escape host defense by restricting IFN-gamma-induced NO production, resisting nitrogen toxic radicals, and limiting phagosome fusion with lysosomes.  相似文献   
42.
A transient expression system using onion epidermal cells was used to investigate domains of the Tobacco mosaic virus (TMV) 126-kDa replicase protein involved in cellular localization. Initially, a nuclear localization signal (NLS), identified within the amino-terminus of the 126-kDa protein, was investigated for its functionality using fusion constructs containing the green fluorescent protein (GFP). Fusion of the amino-terminal 70 amino acids of the 126-kDa protein, containing the NLS, to a beta-glucuronidase-GFP open reading frame (ORF), directed the accumulation of fluorescence to the nucleus. In contrast, similar constructs lacking the NLS or containing a mutated NLS sequence failed to accumulate within the nucleus. Additional investigations using GFP fusion constructs containing the first 178 or 388 amino acids of the 126-kDa protein also displayed nuclear localization. However, fusion constructs encoding the first 781 amino acids or the entire 126-kDa ORF did not accumulate within the nucleus but instead associated with the endoplasmic reticulum (ER), forming spot-like inclusions. Thus, a dominant ER association domain exists between amino acids 388 and 781 of the 126-kDa protein. Interestingly, a full-length 126-kDa GFP fusion construct encoding a nonfunctional NLS mutation also localized to the ER but did not form inclusions. Furthermore, a TMV mutant containing the same nonfunctional NLS mutation failed to replicate in protoplasts. Together these findings suggest that both the NLS and the ER retention domain contribute to the functional localization of the 126-kDa protein.  相似文献   
43.
Therapy for otitis media (OM) due to resistant Streptococcus pneumoniae (MIC of penicillin, >/=2.0 microgram/ml) is challenging. Linezolid, an oxazolidinone, represent a new class of antimicrobial agents with excellent in vitro activity against penicillin-resistant S. pneumoniae; however, in vitro activity against nontypeable Haemophilus influenzae (NTHI) is limited. We evaluated its efficacy against experimental acute OM due to a multidrug-resistant S. pneumoniae isolate and two isolates of NTHI. The chinchilla model was utilized to evaluate the efficacy of linezolid against experimental infection due to S. pneumoniae or NTHI. Serum and middle ear antibiotic concentrations were determined, and sterilization of experimental OM was evaluated. Chinchillas were inoculated directly with S. pneumoniae into the superior bulla. Twenty-four hours after inoculation, all animals had positive middle ear and nasopharyngeal cultures. Animals were given linezolid at 25 mg/kg/dose twice a day (b.i.d.) by orogastric feeding tube or amoxicillin at 40 mg/kg/dose b.i.d. intramuscularly for 5 days. By day 5, all animals in the linezolid group had sterile middle ear cultures and eradication of S. pneumoniae from the nasopharynx. In the amoxicillin group, all nine animals remained middle ear and nasopharynx positive (P < 0.01). In animals inoculated with NTHI, 25 and 37.5 mg/kg b.i.d. failed to sterilize middle ear infection or eradicate colonization. Mean levels in middle ear fluid measured during experimental infection were 12.8 microgram/ml at 2 to 6 h and 4. 1 mirogram/ml at 16 to 17 h after orogastric dosing at 25 mg/kg. Linezolid achieved a high concentration in the middle ear during experimental OM. Linezolid eradicated multidrug-resistant S. pneumoniae from the middle ear and nasopharynx. Experimental infection and nasopharyngeal colonization due to NTHI persisted despite achievement of concentrations in the middle ear that were above the MIC (for NTHI).  相似文献   
44.
新缩瞳剂包公藤甲素人工合成研究   总被引:11,自引:0,他引:11  
包公藤甲素是从包公藤(Erycibe obtusifolia Benth.)茎中提得的一个新莨菪烷生物碱,具有强烈的缩瞳作用,临床用于治疗青光眼。本文报道用合成的6β-乙酰氧基托品酮为原料,经卤代、水解、还原和N-去甲基化等反应合成包甲素(8)。经光谱测定证实8与天然包甲素的结构完全一致。合成品系外消旋体,其作用机理与天然品相同,而强度则减半。  相似文献   
45.
In 1997, the United States Pharmacopeia (USP) established an Ad Hoc Outcomes/Cost Effectiveness Advisory Panel to consider the development of specifications for compiling, indexing, and evaluating outcomes research/cost-effectiveness literature on a disease-specific basis. Such a resource could be used to support pharmaceutical therapy choice decision making by a variety of potential users. The USP had developed a protype health outcomes and pharmacoeconomic annotated registry of the literature on the disease state, congestive heart failure. Other organizations have established and are marketing pharmacoeconomic and health outcome literature registries, with two examples being the HEED database (OHE-IFPMA Database Ltd.) and the University of York NHS Centre for Reviews and Dissemination (DARE).
OBJECTIVE: To share experiences and to identify the needs of decision makers for outcome/pharmacoeconomic information and to discuss whether they are being met by currently available literature sources. Decision makers include health care practitioners, managed care organizations, third party payers, industry and governments.
WORKSHOP FORMAT: The USP congestive heart failure protype literature registry will be described and compared to currently available pharmacoeconomic/outcome databases. Participants will share their assessment of the currently available abstracting service/databases and determine if there is a role for further developments.
DESIRED OUTCOME: To determine if there is a need for a collaborative approach among interested parties to make relevant health outcome/pharmacoeconomic information more accessible to the drug therapy decision makers in a format that is "user friendly."  相似文献   
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裴月湖  李铣  朱廷儒 《药学学报》1989,24(6):413-421
合成了14个新化合物,其中有12个是(S)-(+)-α-甲基丁酰基间苯三酚类化合物。通过对新化合物旋光资料的研究和分析,找到了它们绝对构型与旋光方向的关系。该规律在测定光学活性的α-甲基丁酰基间苯三酚类化合物的绝对构型和开发研究该类药物上,均具有一定的实际应用价值。  相似文献   
49.
In total, 320 vaginal or rectal swabs were cultured on Granada medium (GM) or Group B Streptococcus Differential Agar (GBSDA), and were also inoculated into LIM broth (Todd-Hewitt broth supplemented with selective antibiotics), for detection of group B Streptococcus (GBS). Overall, GBS isolates were detected on 53 of the 320 swabs; 47 of these isolates grew on both GM and GBSDA, five only on GBSDA, and one only following subculture from LIM broth. GBSDA appears to be a valid alternative to GM for the growth of GBS isolates from pregnant women.  相似文献   
50.
从秋季采收的菊科植物大丁草Gerbera anandria(L.)Sch Bip.全草中共分出十三种成分。本文报道其中三个新化合物的结构鉴定.它们分别是3,8-dihydroxy-4-methoxy-coumarin(ⅪⅩ),3,8-dihydroxy-4-methoxy-2-oxo-2 H-1-benzopyran-5-carboxylic acid(ⅩⅦ),和5,8-dihydroxy-7-(4-hydroxy-5-methyl-coumarin-3-)-coumarin(ⅩⅪ)。  相似文献   
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