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1.
The enhanced interest in carotenoid research arises partly because of their application in the food and health industries and partly because of the necessity to find a commercially viable natural source for their mass production. The bottlenecks in finding a natural source of carotenoids which can compete with the synthetic products is the mass production of the organism that produces carotenoids, cell harvesting and extraction methods of carotenoids. The microalga Botryococcus braunii is an interesting organism for its commercial value as a rich source of carotenoids. It contains lutein as major carotenoid which is considered to be one of the beneficial carotenoids in human health applications. The current paper reviews the status of B. braunii as an alternative source of carotenoid production on the commercial scale addressing aspects like cultures of algae, factors that enhance the production and accumulation of carotenoids, cell harvesting methods, and carotenoid extraction. The paper also presents an overview of identification, characterization and structural elucidation of carotenoids from B. braunii and their bioactivity.  相似文献   

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It has been documented that when furnished with an endomembrane signal sequence for the endoplasmic reticulum, -glucuronidase (GUS) is N-glycosylated, resulting in the nearly complete loss of enzymatic activity. To enable use of -glucuronidase as a reporter protein in secretory and vacuolar targeting studies, one of the two putative N-linked glycosylation sites within the GUS gene was altered by site-directed mutagenesis. The second N-linked glycosylation site was not altered because sequence analysis of nucleotide sequences around the second putative glycosylation site revealed that the published sequence was incorrect, and that no such site existed.  相似文献   

4.

Background

The colour of animals' skin, fur, feathers or cuticula has been estimated in a large number of studies. The methods used to do so are diverse, with some being costly and not available to all researchers. In a study to measure plumage colour in a bird species, a new method of creating a colour chart was developed. While colour-charts have their own limitations, these can be minimised when they have the following properties: 1) being readily available to the majority of biologists, 2) containing a large array of colours to allow accurate recording and differentiation of subtle colour differences, 3) low cost, 4) adhering to a world-wide standard, and 5) being available in both hard-copy and digital formats to allow for various analytical methods. The method described below satisfies all of these requirements.

Results

Colour charts estimated to fit the range of the species' plumage colours were created on the computer screen using web software that allowed for HTML-coding (in this case Dreamweaver?). The charts were adjusted using feathers from dead specimens until a satisfying range of darker and lighter colours were found. The resulting chart was printed out and was successfully used in the field to determine the plumage colour of hand-held birds.

Conclusion

Access to a computer and printer, and the software to enable the creation of a chart, is within the reach of the vast majority of biologists. The numbers of colours that can be generated should suit most studies, with the advantage of the method being that the chart can be individually tailored to the species under study. HTML colour coding is a worldwide standard, thus the colours used in studies can be described in the methods section of journal articles using the six-digit alphanumeric code. We believe this method is very useful as a low-tech method for future estimation of individual colour.  相似文献   

5.
Interleukin-2 inducible tyrosine kinase (ITK) is expressed in T cells and plays a critical role in signalling through the T cell receptor. Evidence, mainly from knockout mice, has suggested that ITK plays a particularly important function in Th2 cells and this has prompted significant efforts to discover ITK inhibitors for the treatment of allergic disease. However, ITK is known to have functions outside of its kinase domain and in general kinase knockouts are often not good models for the behaviour of small molecule inhibitors. Consequently we have developed a transgenic mouse where the wild type Itk allele has been replaced by a kinase dead Itk allele containing an inactivating K390R point mutation (Itk-KD mice). We have characterised the immune phenotype of these naive mice and their responses to airway inflammation. Unlike Itk knockout (Itk−/−) mice, T-cells from Itk-KD mice can polymerise actin in response to CD3 activation. The lymph nodes from Itk-KD mice showed more prominent germinal centres than wild type mice and serum antibody levels were significantly abnormal. Unlike the Itk−/−, γδ T cells in the spleens of the Itk-KD mice had an impaired ability to secrete Th2 cytokines in response to anti-CD3 stimulation whilst the expression of ICOS was not significantly different to wild type. However ICOS expression is markedly increased on αβCD3+ cells from the spleens of naïve Itk-KD compared to WT mice. The Itk-KD mice were largely protected from inflammatory symptoms in an Ovalbumin model of airway inflammation. Consequently, our studies have revealed many similarities but some differences between Itk−/−and Itk-KD transgenic mice. The abnormal antibody response and enhanced ICOS expression on CD3+ cells has implications for the consideration of ITK as a therapeutic target.  相似文献   

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Cowling  R.M.  Esler  K.J.  Rundel  P.W. 《Plant Ecology》1999,142(1-2):3-21
Namaqualand is a winter-rainfall desert of some 50000 km2, located in north-western South Africa. For a desert ecosystem, the region is characterized by a unique selective regime, namely highly predictable annual rainfall and a moderate temperature regime throughout the year. This selective regime is responsible for the unique plant ecological features of Namaqualand. These include: the dominance of communities by dwarf to low, shallow-rooted, short-lived and drought-sensitive leaf succulent shrubs; high abundance and diversity of geophytes; winter growth phenology; regular and spectacular spring flowering displays; rapid population turnover of perennials; weak competitive interactions; and high local and regional plant diversity. This paper provides a physiographical, biogeographical and ecological overview as background to this special issue. First, we outline the physiography and climate of Namaqualand, emphasizing unique components of its selective regime. Next we discuss the region's phytogeographical and floristic characteristics. Then we summarize what is known about plant form and function, focusing on growth form mix, phenology, carbon gain, water relations, and reproduction in vegetation dominated by leaf-succulent shrubs. Finally, we interpret Namaqualand's uniquely rich and dynamic plant communities in terms of plant functional processes. These plant ecological patterns and processes are discussed in terms of the predictions of a simple conceptual model for succulent-rich communities.  相似文献   

9.
Infections with certain species of Plasmodium and Babesia induce, among other symptoms, cerebral pathology. The finding of heavily parasitized cerebral capillaries upon postmortem examination has led to the assumption that blockage of capillaries with infected red blood cells caused the cerebral symptoms and subsequent death. As this type of cerebrovascular pathology is found both in humans dying from malaria and in cattle dying from babesiosis, the latter could possibly be used as an animal model for the study of human cerebral malaria. However, before such a model system is adopted, the experimental data concerning cerebral pathology of babesiosis needs critical evaluation. Here, Theo Schetters and Wijnand Eling review the pathological mechanisms in cerebral babesiosis and relate these to cerebral malaria. Finally, they discuss the use of animal model systems for specific aspects of the pathological picture.  相似文献   

10.
To assess the current status of psychodynamic therapy (PDT) as an empirically supported treatment (EST), we carried out a pre-registered systematic umbrella review addressing the evidence for PDT in common mental disorders in adults, based on an updated model for ESTs. Following this model, we focused on meta-analyses of randomized controlled trials (RCTs) published in the past two years to assess efficacy. In addition, we reviewed the evidence on effectiveness, cost-effectiveness and mechanisms of change. Meta-analyses were evaluated by at least two raters using the proposed updated criteria, i.e. effect sizes, risk of bias, inconsistency, indirectness, imprecision, publication bias, treatment fidelity, and their quality as well as that of primary studies. To assess the quality of evidence we applied the GRADE system. A systematic search identified recent meta-analyses on the efficacy of PDT in depressive, anxiety, personality and somatic symptom disorders. High quality evidence in depressive and somatic symptom disorders and moderate quality evidence in anxiety and personality disorders showed that PDT is superior to (inactive and active) control conditions in reducing target symptoms with clinically meaningful effect sizes. Moderate quality evidence suggests that PDT is as efficacious as other active therapies in these disorders. The benefits of PDT outweigh its costs and harms. Furthermore, evidence was found for long-term effects, improving functioning, effectiveness, cost-effectiveness and mechanisms of change in the aforementioned disorders. Some limitations in specific research areas exist, such as risk of bias and imprecision, which are, however, comparable to those of other evidence-based psychotherapies. Thus, according to the updated EST model, PDT proved to be an empirically-supported treatment for common mental disorders. Of the three options for recommendation provided by the updated model (i.e., “very strong”, “strong” or “weak”), the new EST criteria suggest that a strong recommendation for treating the aforementioned mental disorders with PDT is the most appropriate option. In conclusion, PDT represents an evidence-based psychotherapy. This is clinically important since no single therapeutic approach fits all psychiatric patients, as shown by the limited success rates across all evidence-based treatments.  相似文献   

11.

Objective

To determine the expression patterns of NF-κB regulators and target genes in clear cell renal cell carcinoma (ccRCC), their correlation with von Hippel Lindau (VHL) mutational status, and their association with survival outcomes.

Methods

Meta-analyses were carried out on published ccRCC gene expression datasets by RankProd, a non-parametric statistical method. DEGs with a False Discovery Rate of < 0.05 by this method were considered significant, and intersected with a curated list of NF-κB regulators and targets to determine the nature and extent of NF-κB deregulation in ccRCC.

Results

A highly-disproportionate fraction (~40%; p < 0.001) of NF-κB regulators and target genes were found to be up-regulated in ccRCC, indicative of elevated NF-κB activity in this cancer. A subset of these genes, comprising a key NF-κB regulator (IKBKB) and established mediators of the NF-κB cell-survival and pro-inflammatory responses (MMP9, PSMB9, and SOD2), correlated with higher relative risk, poorer prognosis, and reduced overall patient survival. Surprisingly, levels of several interferon regulatory factors (IRFs) and interferon target genes were also elevated in ccRCC, indicating that an ‘interferon signature’ may represent a novel feature of this disease. Loss of VHL gene expression correlated strongly with the appearance of NF-κB- and interferon gene signatures in both familial and sporadic cases of ccRCC. As NF-κB controls expression of key interferon signaling nodes, our results suggest a causal link between VHL loss, elevated NF-κB activity, and the appearance of an interferon signature during ccRCC tumorigenesis.

Conclusions

These findings identify NF-κB and interferon signatures as clinical features of ccRCC, provide strong rationale for the incorporation of NF-κB inhibitors and/or and the exploitation of interferon signaling in the treatment of ccRCC, and supply new NF-κB targets for potential therapeutic intervention in this currently-incurable malignancy.  相似文献   

12.
Root (wilt) disease (RWD) caused by phytoplasma is one of the most devasting diseases of coconut palms. The major symptoms of the disease in leaves are wilting and drooping and flaccidity; ribbing, paling/yellowing and necrosis of leaflets are typical symptoms of foliar diseases. Unopened pale yellow leaflets of spindle leaves are more susceptible to leaf rot disease, which is caused by Exerohilum rostratum and Colletotrichum gloeosporioides. RWD is caused by phytoplasmas, the cell wall-less prokaryotes that are bounded by a “unit” membrane. In ultrathin sections, they appear as a complex multi-branched, beaded, filamentous or spheroidal pleomorphic bodies. The disease was transmitted by plant hoppers (Proutista moesta) and lace wing bug (Stephanitis typica). Phytoplasmas are generally present in the phloem sieve tubes and in the salivary glands of these insect vectors. Phytoplasmas cannot be cultured in vitro, and hence it is very difficult to identify them. Using polymerase chain reaction technique, group-specific primers have been applied to detect mixed-phytoplasma infections in a single host. RWD, is a non-lethal, debilitating disease, and hence an integrated approach for the management of this disease in coconut palms has been discussed in this study.  相似文献   

13.
IntroductionPatients undergoing immunosuppressive therapy are at increased risk of infection. Community-acquired pneumonia and invasive pneumococcal disease account for substantial morbidity and mortality in this population and may be prevented by vaccination. Ideally, immunization to pneumococcal antigens should take place before the start of immunosuppressive treatment. Often, however, the treatment cannot be delayed. Little is known about the efficacy of pneumococcal vaccines during immunosuppressive treatment. The objectives of this study were to determine the percentage of vaccine-naïve, immunosuppressed adults with inflammatory diseases seroprotected against Streptococcus pneumoniae and to assess factors associated with the immunogenicity, clinical impact and safety of 23-valent pneumococcal polysaccharide vaccine (PPV) in seronegative subjects.MethodsThis observational study included patients 18 years of age and older who were receiving prednisone ≥20 mg/day or other immunosuppressive drugs. Exclusion criteria were PPV administration in the previous 5 years, intravenous immunoglobulins and pregnancy. Serum immunoglobulin G (IgG) antibody levels against six pneumococcal serotypes were measured. Seropositivity was defined as IgG of 0.5 μg/ml or greater for at least four of six serotypes. Seronegative patients received PPV, and seropositive patients were included as a comparison group. Vaccine response and tolerance were assessed after 4–8 weeks. Disease activity was evaluated on the basis of the Physician Global Assessment scores. Serology was repeated after 1 year, and information on any kind of infection needing medical attention was collected. Outcomes were the proportion of seropositivity and infections between vaccinated and unvaccinated patients.ResultsOf 201 included patients, 35 received high-dose corticosteroids and 181 were given immunosuppressive drugs. Baseline seronegativity in 60 (30 %) patients was associated with corticotherapy and lower total IgG. After PPV, disease activity remained unchanged or decreased in 81 % of patients, and 87 % became seropositive. After 1 year, 67 % of vaccinated compared with 90 % of observed patients were seropositive (p < 0.001), whereas the rate of infections did not differ between groups. Those still taking prednisone ≥10 mg/day tended to have poorer serological responses and had significantly more infections.ConclusionsPPV was safe and moderately effective based on serological response. Seropositivity to pneumococcal antigens significantly reduced the risk of infections. Sustained high-dose corticosteroids were associated with poor vaccine response and more infections.  相似文献   

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Obstacles in elucidating the role of oxidative stress in?aging include difficulties in (1) tracking in?vivo oxidants, in (2) identifying affected proteins, and in (3) correlating changes in oxidant levels with life span. Here, we used quantitative redox proteomics to determine the onset and the cellular targets of oxidative stress during Caenorhabditis elegans' life span. In parallel, we used genetically encoded sensor proteins to determine peroxide levels in live animals in real time. We discovered that C.?elegans encounters significant levels of oxidants as early as during larval development. Oxidant levels drop rapidly as animals mature, and reducing conditions prevail throughout the reproductive age, after which age-accompanied protein oxidation sets in. Long-lived daf-2 mutants transition faster to reducing conditions, whereas short-lived daf-16 mutants retain higher oxidant levels throughout their mature life. These results suggest that animals with improved capacity to recover from early oxidative stress have significant advantages later in life.  相似文献   

16.
Alzheimer’s disease drug discovery regarding exploration into the molecules and processes has focused on the intrinsic causes of the brain disorder correlated with the accumulation of amyloid-β. An anti-amyloidogenic bis-styrylbenzene derivative, KMS80013, showed excellent oral bioavailability (F = 46.2%), facilitated brain penetration (26%, iv) in mouse and target specific in vivo efficacy in acute AD mouse model attenuating the cognitive deficiency in Y-maze test. Acute toxicity (LD50 >2000 mg/kg) and hERG channel inhibition (14% at 10 μM) results indicated safety of KMS80013.  相似文献   

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The effects of the following drugs: nimodipine (1 mg/kg b. w., i. p.), 2-amino-5-phosphonovaleric acid (4mg/kg b.w., i.p.) and propentofylline (25mg/kg b.w., i.p.), administered (alone or in combination) at the end of 15 min bilateral ischemia in gerbils were evaluated on mitochondrial superoxide dismutase (SOD), glutathione reductase (GR), glucose-6 phosphate dehydrogenase (G6PD), monoamine oxidase (MAO) activities, and thiobarbituric acid reactive material (TBARM), and brain water content at 1 hour of reperfusion. The combined treatment virtually abolished early postischemic brain edema (4.1% v.s. 0.6%) and efficiently counteracted ischemia-induced changes [decreased SOD (79% v.s. 98%), GR (52% v.s. 105%) and MAO (25% v.s. 79%), and increased TBARM (198% v.s. 108%)]. The same combination of drugs administered 15 min before ischemia had a similar effect (e.g., reduced brain swelling and lipid peroxidation) as when given at the end of ischemia, whereas a limited or absent impact was seen when the drugs were given 15 min or 1 hour after ischemia, respectively. The data suggest that (post)ischemic brain swelling and mitochondrial dysfunction can be reduced by drugs which synchronously prevent processes induced in the early stages of reperfusion.  相似文献   

19.
There is much interest in the use of mesenchymal stem cells/marrow stromal cells (MSC) to treat neurodegenerative disorders, in particular those that are fatal and difficult to treat, such as Huntington's disease. MSC present a promising tool for cell therapy and are currently being tested in FDA-approved phase I-III clinical trials for many disorders. In preclinical studies of neurodegenerative disorders, MSC have demonstrated efficacy, when used as delivery vehicles for neural growth factors. A number of investigators have examined the potential benefits of innate MSC-secreted trophic support and augmented growth factors to support injured neurons. These include overexpression of brain-derived neurotrophic factor and glial-derived neurotrophic factor, using genetically engineered MSC as a vehicle to deliver the cytokines directly into the microenvironment. Proposed regenerative approaches to neurological diseases using MSC include cell therapies in which cells are delivered via intracerebral or intrathecal injection. Upon transplantation, MSC in the brain promote endogenous neuronal growth, encourage synaptic connection from damaged neurons, decrease apoptosis, reduce levels of free radicals, and regulate inflammation. These abilities are primarily modulated through paracrine actions. Clinical trials for MSC injection into the central nervous system to treat amyotrophic lateral sclerosis, traumatic brain injury, and stroke are currently ongoing. The current data in support of applying MSC-based cellular therapies to the treatment of Huntington's disease is discussed.  相似文献   

20.
We have studied the effect of in vivo treatment with trioxsalen on DNA replication in mammalian cells. In vitro cultured bovine liver cells were exposed to two or four cycles of treatment with 45 μM trioxsalen followed by irradiation with long-wave ultraviolet light. Thymidine incorporation was reduced by about 95% during the first hour after a double treatment. A large proportion of the label was released in alkaline sucrose gradients as a low molecular weight fraction (average length about 500 nucleotides) which was supposed to consist of replication origins containing DNA fragments. From the relative quantities of this DNA obtained at different times of the S phase we concluded that it contains a considerable but not precisely determinable proportion of non-origin DNA. We also find that the fraction is contaminated by a large excess of non-replicating bulk DNA.  相似文献   

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