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861.
The anaphase‐promoting complex/cyclosome (APC/C) is an E3 ubiquitin ligase and key regulator of cell cycle progression. Since APC/C promotes the degradation of mitotic cyclins, it controls cell cycle‐dependent oscillations in cyclin‐dependent kinase (CDK) activity. Both CDKs and APC/C control a large number of substrates and are regulated by analogous mechanisms, including cofactor‐dependent activation. However, whereas substrate dephosphorylation is known to counteract CDK, it remains largely unknown whether deubiquitinating enzymes (DUBs) antagonize APC/C substrate ubiquitination during mitosis. Here, we demonstrate that Cezanne/OTUD7B is a cell cycle‐regulated DUB that opposes the ubiquitination of APC/C targets. Cezanne is remarkably specific for K11‐linked ubiquitin chains, which are formed by APC/C in mitosis. Accordingly, Cezanne binds established APC/C substrates and reverses their APC/C‐mediated ubiquitination. Cezanne depletion accelerates APC/C substrate degradation and causes errors in mitotic progression and formation of micronuclei. These data highlight the importance of tempered APC/C substrate destruction in maintaining chromosome stability. Furthermore, Cezanne is recurrently amplified and overexpressed in numerous malignancies, suggesting a potential role in genome maintenance and cancer cell proliferation.  相似文献   
862.
Longstanding (chronic) adductor-related groin pain syndrome is a widely common problem for athletes in many sports activities which often drastically reduces player activity and performance. The first choice in therapeutic treatment is conservative therapy. The objective of this study is to provide a systematic review regarding conservative treatment for longstanding adductor-related groin pain syndrome present in literature today. Furthermore, this study aims to give a critical vision of the current state of the art of the considered topic. After screening 234 articles, 19 studies following the inclusion criteria were included and summarized in this current systematic review and seven different types of therapeutic interventions were described. Compression clothing therapy, manual therapy together with strengthening exercise and prolotherapy were the therapeutic interventions which showed both the greatest level of strength of evidence (Moderate) and grade of recommendation (D). The remaining four types of therapeutic interventions i.e.: corticoid injection, platelet rich plasma therapy, intra-tissue percutaneous electrolysis and pulse-dose radiofrequency, showed both lower levels of strength of evidence (Conflicting) and grade of recommendation (C). In conclusion the literature available on the conservative treatment for longstanding adductor-related groin pain syndrome is limited and characterized by a low level of evidence. Therefore, our recommendation is to refer only to the few studies with higher level of evidence and at the same time to encourage further research in this area. The intervention showing the greater level of strength of evidence, and the greater grade of recommendation are compression clothing therapy, manual therapy and strengthening exercise, and prolotherapy. Other therapeutic interventions such as intra-tissue percutaneous electrolysis and pulse-dose radiofrequency seem promising but require further studies to confirm their efficacy.  相似文献   
863.
This paper describes the inferential method, an approach for reconstructing protein and nucleotide sequences of ancestral species, starting from known, homologous, contemporary sequences. The method requires knowledge of the topology of the phylogenetic tree, whose nodes are the species to whom the reconstructed sequences belong.The method has been tested by computer simulation of speciation and nucleotide substitutions, starting from a single ancestral sequence, and by subsequent reconstruction of nodal sequences. Results have shown that reconstructions obtained by the inferential method are affected by limited error frequencies, which (1) are proportional to the squares of nucleotide substitution rates and of internodal distances, and (2) are little influenced by non-uniformity of transformation rates of nucleotides.Furthermore, good agreement of the results has been obtained by comparing protein-sequence reconstructions carried out with the inferential method with those obtained using the maximum parsimony method in two different cases: e.g., a reconstruction of simulated sequences and a reconstruction of mammalian ribonuclease sequences.Abbreviations used MP maximum parsimony method - ML maximum likelihood method - IM inferential method - MY millions of years - N-tree natural-like phylogenetic tree - E-tree equibranched phylogenetic tree - EA percentage number of erroneous amino acids in a reconstructed sequence - EC percentage number of erroneous codons in a reconstructed sequence - t n time interval between a P- and its - F-sequence nucleotides and amino acids are indicated by their I.U.B. codes (N.C.-I.U.B., 1985) Correspondence to: A. Di Donato  相似文献   
864.
Janzen proposed that foliage of herbaceous plants may serve as the attractant for large herbivore dispersal of seeds. Such herbivore dispersal was envisioned to select for traits enhancing ingestion and passage of viable seeds through the animal. We tested this “Foliage is the Fruit” (FF) hypothesis by collecting and collating appropriate data from Buchloe dactyloides (buffalograss), one of the two dominant grasses of the shortgrass prairie. Passage of buffalograss diaspores through cattle had a positive effect on germination and seedling growth from intact diaspores, damage other than that due to mastication (15%) was minimal, and retention time was 1–5 days. This combination of retention time and migratory herbivores during the northward expansion of shortgrass prairie should have enhanced migration of buffalograss northward to Montana from its area of origin in central Mexico, and our comparisons with its five close dioecious relatives (the “Buchloe group”) showed that buffalograss does possess a suite of distinctive FF traits. Lab analyses of foliage quality and digestibility also confirmed the high quality of its foliage. After reviewing comparable data for Bouteloua gracilis (blue grama), we conclude that buffalograss and blue grama, which dominate major portions of the largest North American steppe Province, provide strong support for the FF hypothesis.  相似文献   
865.
Growing evidence indicates that inflammatory reactions play an important role in the pathogenesis of alcoholic liver disease (ALD). The implication of immunity in fueling chronic inflammation in ALD has emerged from clinical and experimental evidence showing the recruitment and the activation of lymphocytes in the inflammatory infiltrates of ALD and has received further support by the recent demonstration of a role of Th17 lymphocytes in alcoholic hepatitis. Nonetheless, the mechanisms by which alcohol triggers adaptive immune responses are still incompletely characterized. Patients with advanced ALD show a high prevalence of circulating IgG and T-lymphocytes towards epitopes derived from protein modification by hydroxyethyl free radicals (HER) and end-products of lipid peroxidation. In both chronic alcohol-fed rats and heavy drinkers the elevation of IgG against lipid peroxidation-derived antigens is associated with an increased production of pro-inflammatory cytokines/chemokines and with the severity of histological signs of liver inflammation. Moreover, CYP2E1-alkylation by HER favors the development of anti-CYP2E1 auto-antibodies in a sub-set of ALD patients. Altogether, these results suggest that allo- and auto-immune reactions triggered by oxidative stress might contribute to fuel chronic hepatic inflammation during the progression of ALD.  相似文献   
866.
867.
868.
Echocardiography is increasingly used in the management of the critically ill patient as a non-invasive diagnostic and monitoring tool. Whilst in few countries specialized national training schemes for intensive care unit (ICU) echocardiography have been developed, specific guidelines for ICU physicians wishing to incorporate echocardiography into their clinical practice are lacking. Further, existing echocardiography accreditation does not reflect the requirements of the ICU practitioner. The WINFOCUS (World Interactive Network Focused On Critical UltraSound) ECHO-ICU Group drew up a document aimed at providing guidance to individual physicians, trainers and the relevant societies of the requirements for the development of skills in echocardiography in the ICU setting. The document is based on recommendations published by the Royal College of Radiologists, British Society of Echocardiography, European Association of Echocardiography and American Society of Echocardiography, together with international input from established practitioners of ICU echocardiography. The recommendations contained in this document are concerned with theoretical basis of ultrasonography, the practical aspects of building an ICU-based echocardiography service as well as the key components of standard adult TTE and TEE studies to be performed on the ICU. Specific issues regarding echocardiography in different ICU clinical scenarios are then described. Obtaining competence in ICU echocardiography may be achieved in different ways – either through completion of an appropriate fellowship/training scheme, or, where not available, via a staged approach designed to train the practitioner to a level at which they can achieve accreditation. Here, peri-resuscitation focused echocardiography represents the entry level – obtainable through established courses followed by mentored practice. Next, a competence-based modular training programme is proposed: theoretical elements delivered through blended-learning and practical elements acquired in parallel through proctored practice. These all linked with existing national/international echocardiography courses. When completed, it is anticipated that the practitioner will have performed the prerequisite number of studies, and achieved the competency to undertake accreditation (leading to Level 2 competence) via a recognized National or European examination and provide the appropriate required evidence of competency (logbook). Thus, even where appropriate fellowships are not available, with support from the relevant echocardiography bodies, training and subsequently accreditation in ICU echocardiography becomes achievable within the existing framework of current critical care and cardiological practice, and is adaptable to each countrie's needs.  相似文献   
869.
870.
In the late seventies, a small tribal population of Paraguay, the Ache, living under natural conditions, was studied. Data from this population turn out to be useful for considerations about evolutionary hypotheses on the aging phenomenon. 1) Ache show an age-related increasing mortality, which strongly limits the mean duration of life, as observed in other studies on mammal and bird species. 2) According to current theories on aging, in the wild very few or no individual reach old age and, so, aging cannot be directly influenced by natural selection. However, data from our population show that a significant proportion of the population reaches in the wild 60 and 70 years of age. 3) Data from Ache are also in agreement with the observation about an inverse correlation between extrinsic mortality and deaths due to the age-related increasing mortality. 4) For many gerontologists, the age-related decline of vital functions is a consequence of the gradual decline of cell turnover, genetically determined and regulated by the declining duplication capacities of stem cells. The current interpretation is that these restrictions are a general defense against the proliferation of any tumoral mass. However, among wild Ache cancer is virtually unknown in non-elderly subjects, and only among older individuals are there deaths attributable to oncological diseases. Moreover, fitness decline begins long before oncological diseases have fatal effects in significant numbers. This completely disproves the current hypothesis, because a supposed defense against a deadly disease cannot exterminate a population before the disease begins to kill. These data are consistent with similar data from other species studied under natural conditions, and they bring new arguments against the non-adaptive interpretation of aging and in support of the adaptive interpretation.  相似文献   
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