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1.
前已报道[1]从唇形科香茶菜属植物细锥香茶菜(Rabdosiacoetsa(Buch.Han.exD.Don)Hara)中分离到3个结晶单体,并测定了其中两个单体——细锥香茶菜甲素(1)和乙素的结构。本文通过1H-1HCOSY、13C-1HCOSY和NOESY,修订细锥香茶菜甲素(1)的结构为(2),并经理化常数测定和光谱分析,确定了另一结晶单体——微量新成分细锥香茶菜丙素(3)的结构。(2)R1=R2=R4=H,R3=OAc,R5=OCH3(3)R1=R3=R4=H,R2=OAc,R5=OCH… 相似文献
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应用核仁组成区嗜银蛋白(AgNOR)技术及癌胚抗原(CEA)免疫组化染色对98例乳腺良、恶性病变进行对比研究。结果表明:AgNOR计数与肿瘤增殖活跃程度及生物学行为是一致的。乳腺癌中AgNOR计数显著高于良性病变(P<0.01)。浸润癌AgNOR计数比其他类型乳腺癌高。CEA染色在乳腺良性病变中基本阴性,恶性病变中阳性率80.8%。乳腺癌中AgNOR计数与CEA分布之间呈线性相关(r=0.82,P<0.05)。CEA阳性乳腺癌组与CEA阴性组AgNOR计数差异显著(P<0.05)。提示:AgNOR定量研究和CEA分布在乳腺良、恶性病变的鉴别及肿瘤恶性程度的研究中具有相似的参考价值。 相似文献
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对我国文献中记载的前原鹅观草(Roegneriamayebarana(Honda)Ohwi)的标本和植物,与原产于日本的该种进行了比较形态学、细胞学研究,二者差异显著。作者认为我国所记载的该种种名应是山东鹅观草(Roegneriashandongensis(B.Salomon)J.L.Yang,Y.H.ZhouetYen),其内稃先端钝圆,长为外稃的3/4,染色体数为2n=4x=28,具SY染色体组,结实率达90%以上,过去被错定为R.mayebarana。而R.mayebarana在日本系一天然杂种,其内稃先端尖,与外稃等长或稍短,染色体数为2n=6x=42,具HSY染色体组,结实率极低,仅0.2%~0.4%。 相似文献
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福建两种棘蛙的核型和Ag-NORs观察结果如下:九龙棘蛙,2n=26(22M+4SM),NF=52,5+8模式,Ag-NORs位于6pinter,小棘蛙,2n=26(20M+6SM),NF=52,5+8模式,次缢痕和Ag-NORs在6pinter。二者均未发现与性别分化相关的异形染色体。根据已知棘蛙属内的核型资料,对该属种间和居群间的核型演化机制进行了讨论。 相似文献
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云南三种同域分布的棘蛙(蛙科Ranidae:无尾目Anura)的核型和银带研究 总被引:7,自引:0,他引:7
本文比较分析了云南景东地区三种同域分布棘蛙的核型和Ag-NORs。花棘蛙2n=26(16M+ 10SM),NF=52,次缢痕和Ag-NORs位于1pinter,Nos.2-4,8,9等为SM。棘肛蛙2n=40(16M+ 20SM+2ST+2T),NF=78,Nos.5-9,11-13,15,17等10对为SM,No.3为ST,No.18为T,其余 均为M,Ag-NORs位于11P。二种的Ag-NORs都有异形现象。双团棘胸蛙2n=64T,次缢痕和Ag- NORS在4qper。都未发现异形性染色体。最后,对棘蛙属的核型演化机制和物种形成方式作了讨论。 相似文献
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四种无尾两栖动物的核型和银染 总被引:4,自引:1,他引:4
本文报道了二种角蟾和二种树蛙的核型和银染NOR:无量出角蟾:2n=26(24+2SM),5+8,SC和Ag-NORs位于6q^per沙坪角蟾:2n=26(16M+8SM+2ST),5+8,SC位于1q^per,但Ag-NORs有二对,分别是lq^per和2q^per;黑蹼树蛙:2n=26(24M+2SM),5+8,SC和Ag-NORs在lp^inter;背条跳树蛙;2n=16(12M+4SM),S 相似文献
9.
表油菜素内酯(epiBR)0.05mg/L能促进绿豆幼叶的衰老,其叶绿素和蛋白质含量均明显低于对照。绿豆幼叶经epiBR处理后,可使过氧化物酶活性明显增加,但同工酶谱无变化;超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性随epiBR处理时间的延长而降低。epiBR能促进丙二醛(MDA)含量增加,而其含量与SOD和CAT活性是显著负相关。 相似文献
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表油菜素内酯对绿豆幼叶衰老的促进作用 总被引:37,自引:0,他引:37
表油菜素内酯(epiBR)0.05mg/L能促进绿豆幼叶的衰老,其叶绿素和蛋白质含量均低于对照。绿豆幼叶经epiBR处理后,可使过氧化物酶活性明显增加,但同工酶谱无变化;超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性随epiBR处理时间的延长而降低。epiBR能促进丙二醛(MDA)含量增加,而其含量与SOD和CAT活性呈显著负相关。 相似文献
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OBJECTIVE--To measure the effect of parenteral antibiotics given before admission to hospital on mortality and on bacteriological investigations in meningococcal disease. DESIGN--Retrospective review of hospital notes and laboratory and public health medicine department records. SETTING--Three health districts in south west England. SUBJECTS--Patients with meningococcal disease in Gloucester district presenting between 1 January 1982 and 31 December 1991 (n = 190); patients with meningococcal disease in Plymouth (n = 118) and Bath (n = 73) districts presenting between 1 January 1988 and 31 December 1991 (total = 381). MAIN OUTCOME MEASURE--Number of deaths from meningococcal disease. RESULTS--Parenteral antibiotic given by general practitioners was associated with a substantial reduction in mortality (from 9% to 5%; relative risk 0.6, 95% confidence interval 0.2 to 1.5); patients with a rash were more likely to be given parenteral antibiotics, and mortality was further reduced (from 12% to 5%; 0.5, 0.2 to 1.4). In a district where such treatment was regularly encouraged its use increased from 5% to 40% of cases over 10 years (p = 0.00001). Treatment with parenteral antibiotics before admission made isolation of meningococci from blood and cerebrospinal fluid less likely but did not affect nasopharyngeal cultures. CONCLUSIONS--General practitioners should carry benzylpenicillin in their emergency bags at all times and should administer it promptly, preferably intravenously, whenever meningococcal disease is suspected, unless the patient has had an anaphylactic reaction to penicillin. Specimens for culture should include a nasopharyngeal swab. 相似文献
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Vogel U Christensen J Dybdahl M Friis S Hansen RD Wallin H Nexø BA Raaschou-Nielsen O Andersen PS Overvad K Tjønneland A 《Mutation research》2007,624(1-2):88-100
Inflammatory bowl disease predisposes to cancer of the colorectum, and the use of non-steroidal anti-inflammatory drugs (NSAIDs) decreases the risk; hence genetic variations that modify the inflammatory response may alter the risk of colorectal cancer (CRC). The purpose of this study was to determine if polymorphisms associated with an altered inflammatory response are associated with colorectal cancer risk, and to investigate the possible interaction with lifestyle factors such as alcohol use, smoking and NSAID use. We studied 355 adenocarcinoma cases and 753 control persons, nested within the prospective "Diet, Cancer and Health" study. None of the polymorphisms were associated with risk of colorectal cancer. A statistically significant interaction between PPARgamma2 Pro(12)Ala and alcohol was found, where alcohol use was associated with a 22% increased risk of CRC per 10g alcohol/day among carriers of the variant allele but not among homozygous wild type allele carriers (P for interaction=0.02). Moreover, an interaction between DLG5 R30Q and NSAID use was found (P for interaction=0.02). Our results do not suggest that inborn variations in the inflammatory response play any major role in risk of colorectal cancer. 相似文献
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Sarah D de Ferranti John P A Ioannidis Joseph Lau William V Anninger Michael Barza 《BMJ (Clinical research ed.)》1998,317(7159):632-637
Objectives: To examine whether antibiotics are indicated in treating uncomplicated acute sinusitis and, if so, whether newer and more expensive antibiotics with broad spectra of antimicrobial activity are more effective than amoxycillin or folate inhibitors. Design: Meta-analysis of randomised trials. Setting: Outpatient clinics. Subjects: 2717 patients with acute sinusitis or acute exacerbation of chronic sinusitis from 27 trials. Interventions: Any antibiotic versus placebo; amoxycillin or folate inhibitors versus newer, more expensive antibiotics. Main outcome measurements: Clinical failures and cures. Results: Compared with placebo, antibiotics decreased the incidence of clinical failures by half (risk ratio 0.54 (95% confidence interval 0.37 to 0.79)). Risk of clinical failure among 1553 randomised patients was not meaningfully decreased with more expensive antibiotics as compared with amoxycillin (risk ratio 0.86 (0.62 to 1.19); risk difference 0.9 fewer failures per 100 patients (1.4 more failures to 3.1 fewer failures per 100 patients)). The results were similar for other antibiotics versus folate inhibitors (risk ratio 1.01 (0.52 to 1.97)), but data were sparse (n=410) and of low quality. Conclusions: Amoxycillin and folate inhibitors are essentially as effective as more expensive antibiotics for the initial treatment of uncomplicated acute sinusitis. Small differences in efficacy may exist, but are unlikely to be clinically important.
Key messages
- A major question in managing acute sinusitis is whether antibiotics should be used, and if so which drugs should be chosen
- In a comprehensive meta-analysis we evaluated evidence from randomised controlled trials comparing, firstly, antibiotics against placebo and, secondly, amoxycillin and folate inhibitors against newer, more expensive antibiotics
- Antibiotics were significantly more efficacious than placebo in achieving cure of clinical symptoms, but over two thirds of placebo patients showed spontaneous resolution or improvement of symptoms
- Amoxycillin and folate inhibitors had overall similar efficacy compared with newer antibiotics
- The current evidence does not justify the use of expensive, broad spectrum antibiotics in the community for treating uncomplicated acute sinusitis
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《Animal biotechnology》2013,24(1):129-147
It is generally believed that it is better to use medicinal products as therapeutics to treat disease situations, using high doses for short periods of time, rather than as prophylactics, when low doses are fed continuously. It is therefore the continuous use of low levels of medicinal products as growth promoters in farm animals that has been brought into question, as it is thought that this may increase the risk of development of bacterial resistance to antibiotics used as therapeutic drugs to treat disease in humans. 相似文献
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BackgroundPost-operative endophthalmitis is a rare and dreaded complication in ophthalmic operations because it often induces irreparable vision loss. Although many ophthalmological studies aimed at reducing the rate of endophthalmitis have been performed around the world, controversy continues to surround some issues, including the choice of antimicrobials and their route of administration, duration and timing. The aim of this study is to investigate some of these unresolved issues.MethodsA systematic review and meta-analysis of randomized controlled trials and observational studies was performed. The PubMed, EMBASE, Cochrane Library and Clinical Trials databases were searched to identify studies published until Feb. 2016. The relative risk (RR) for each clinical outcome data is presented with 95% confidence intervals (CIs). Pooled estimates of effects were calculated using random-effect models.ResultsThirty-four studies from twenty-four reports involving 1264797 eyes were included in this analysis. Endophthalmitis occurred, on average, in one out of 6177 eyes when intracameral vancomycin/moxifloxacin were used and in one out of 1517 eyes when intracameral vancomycin/moxifloxacin were not used. The relative risk (95% CI) of endophthalmitis was reduced to 0.20 (0.10, 0.42) when intracameral antibiotics were used (p<0.0001). The subconjunctival injection of antibiotics was not superior to other administration routes included in this study (RR = 1.67, 95% CI (0.55, 5.05), p = 0.36). A statistically significant difference was found in the rate of endophthalmitis between the use and lack of use of topical antibiotics (RR = 0.65, 95% CI (0.43, 0.99), p = 0.04). However, no statistically significant difference was found in microbial isolation rates between these groups (RR = 0.77, 95% CI (0.34, 1.75), p = 0.53). When long-term and short-term use of topical antibiotics before surgery were compared, a statistically significant difference was found in microbial isolation rates (RR = 0.57, 95% CI (0.44, 0.74), p<0.0001).ConclusionsThis meta-analysis concluded intracameral antibiotics are effective at preventing endophthalmitis in ocular surgery. A randomized controlled trial confirms the efficacy of cefuroxime but recent large cohort studies support the efficacy of vancomycin/moxifloxacin intracamerally. Intracameral antibitoics are superior to subconjunctival injections but that irrigation antibitoic data are not of enough quality to make a comparison. Different results were found in two clinical outcomes between the use or lack of use of topical antibiotic therapy, we did not find sufficient evidence to conclude that its use prevents endophthalmitis. 相似文献
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Tamaz Mdzinarashvili Irina Papukashvili Tamar Partskhaladze Nino Shengelia Mariam Khvedelidze 《Cell biochemistry and biophysics》2013,66(3):759-764
Continuous, real-time observation of bacterial growth has a great advantage for studying the mechanisms of interactions of various compounds with the bacterial cell membrane. With the use of physical methods, which are specific for assessment of continuous changes in turbidity over time, we have shown that bacterial growth was affected by not only on types of antibiotics and phages, but also by their concentration in media. Low concentration of antibiotics and bacteriophages in media has no effect on the bacterial growth process. Our research has shown that if bacterial cell membrane is not completely saturated with antibiotics membrane sensitive sites (MSS), or bacteriophages free unbounded receptors are remained, bacterial growth continues unimpeded. 相似文献
17.
Background
Previous studies suggest that maternal antibiotics exposure during pregnancy may increase the risk of childhood asthma, but the results were inconsistent. Furthermore, most studies did not examine periconception period as an exposure window. We aim to assess the associations between maternal exposure to specific antibiotics before and during pregnancy and the risk of asthma in early childhood.Methods
Data from the Collaborative Perinatal Project were used. Maternal exposure to antibiotics before and during pregnancy was recorded at each prenatal visit. A total of 39,907 singleton children were followed up to 7 years of age. Multilevel multiple logistic regression models were used to control for potential confounders and account for multiple pregnancies per woman.Results
Maternal use of penicillin or chloramphenicol was associated with an increased risk of asthma in the offspring (adjusted odds ratio = 1.21, 95% confidence interval 1.08–1.36 for penicillin; 1.72 [1.14–2.59] for chloramphenicol). The risk was significantly increased if penicillin or chloramphenicol was used in the 1st trimester (1.09 [1.04–1.13] for penicillin and 1.23 [1.01–1.51] for chloramphenicol).Conclusion
Maternal exposure to certain antibiotics is associated with childhood asthma by 7 years of age. Early pregnancy may be a sensitive window. 相似文献18.
Bernadette Purcell Susanne Samuelsson Susan J M Hahné Ingrid Ehrhard Sigrid Heuberger Ivonne Camaroni André Charlett James M Stuart 《BMJ (Clinical research ed.)》2004,328(7452):1339
Objective To summarise the evidence for the role of antibiotics in preventing further cases of meningococcal disease through chemoprophylaxis given to the index patient, household contacts, and children in day care settings after a single case.Design Systematic review.Methods Studies were identified by searching Embase (1983-2003), Medline (1965-2003), and CAB Health (1973-2003) and by contacting the World Health Organization and the European meningococcal disease surveillance network and examining references of identified papers. The review included all studies with at least 10 cases in which outcomes were compared between treated and untreated groups.Main outcome measure Subsequent cases of meningococcal disease 1-30 days after onset of disease in the index patient.Results Four observational studies and one small trial met the inclusion criteria. Meta-analysis of studies on chemoprophylaxis given to household contacts showed a significant reduction in risk (risk ratio 0.11, 95% confidence interval 0.02 to 0.58). The number needed to treat to prevent a case was estimated as 218 (121 to 1135). Primary outcome data were not available in studies of chemoprophylaxis given to the index patient: when prophylaxis had not been given, rate of carriage after discharge from hospital was estimated as 3% (0 to 6), probably an underestimate of the true rate. No studies of chemoprophylaxis in day care settings were identified that met the inclusion criteria.Conclusion There have been no high quality experimental trials looking at control policies for meningococcal disease. The best available evidence is from retrospective studies. The risk of meningococcal disease in household contacts of a patient can be reduced by an estimated 89% if they take antibiotics known to eradicate meningococcal carriage. Chemoprophylaxis should be recommended for the index patient and all household contacts. 相似文献
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Anaphylactic reactions following the injection of penicillin or other antibiotics have increased greatly during the past several years. These untoward reactions to penicillin were infrequent during the first nine years of penicillin therapy and there can be no doubt that hypersensitivity to these drugs is developing in many people. Therefore promiscuous use of them is to be condemned. It is safer not to use antibiotics parenterally in patients with allergic conditions such as bronchial asthma. The further use of a particular antibiotic should be avoided if the patient has previously shown any hypersensitivity to that drug.A questionnaire was answered by more than 1,000 California physicians who reported that over 300 patients had severe anaphylactic reactions from parenteral penicillin and streptomycin. There were seven deaths.Since the antibiotics should still be used when needed, prevention of anaphylaxis is of fundamental importance. The frequency of these reactions can be greatly reduced by the use of antihistaminic solutions combined with the antibiotics. Treatment of these shock-like reactions demands the prompt administration of epinephrine intramuscularly, antihistaminic solutions intravenously and oxygen. 相似文献
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The presence of infection in allergic disease produces a confused picture in which two different causative factors must be clearly separated by the physician if he is to treat the patient successfully. The effects of infection are not consistent. There are situations, as seen in infectious diseases, where symptoms of allergic disease are temporarily relieved and others where the infection may intensify or precipitate the allergic condition. It is likewise important to recognize the complications superimposed upon allergic disease by infection. In such cases, control of the infection is as dependent upon control of the allergy as it is upon antibiotics. 相似文献