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1.
The paper examines impacts on mortality of heat waves in 2003, the hottest summer on record in the Czech Republic, and compares them with previous similar events. While most summer heat waves over the period since 1986 were associated with significantly elevated mortality, this was not the case for three out of the four heat waves in 2003. The relatively weak mortality response was particularly noteworthy for the most severe heat wave which occurred in the first 10 days of August 2003 and resulted in enormous excess mortality in some western European countries. A mortality displacement effect and short-term adaptation to heat contributed to the reduced mortality impacts of the heat waves that followed after previous relatively warm periods. However, the decreased mortality response of the 2003 heat waves compared to previous heat waves in the 1990s is also likely to have arisen from positive health-care and other socio-economic changes in the post-communist central European region over the past decade, as well as a better public awareness of heat-related risks due to enhanced media coverage and regular biometeorological forecast and warnings.  相似文献   

2.
RNA-binding proteins, which are involved in the synthesis, processing, transport, translation, and degradation of RNA, are emerging as important, often multifunctional, cellular regulatory proteins. Although relatively few RNA-binding proteins have been studied in plants, they are being identified with increasing frequency, both genetically and biochemically. RNA-binding proteins that regulate chloroplast mRNA stability and translation in response to light and that have been elegantly analyzed in Clamydomonas reinhardtii have counterparts with similar functions in higher plants. Several recent reports describe mutations in genes encoding RNA-binding proteins that affect plant development and hormone signaling.  相似文献   

3.
It was found that ethionine partially inhibits the transport of the inducer (TMG) of β-galactosidase into the cells ofEscherichia coli ML-30. The synthesis of β-galactosidase-specific messenger RNA is not inhibited. Ethionine appears to be incorporated into proteins synthesized by the strains used. The incorporation of ethionine into the molecule of β-galactosidase results in the synthesis of an enzymically inactive, immunologically cross-reacting protein.  相似文献   

4.

Background

Goblet cell carcinoid (GCC) of the appendix is a rare neoplasm that share histological features of both adenocarcinoma and carcinoid tumor. While its malignant potential remains unclear, GCC's are more aggressive than conventional carcinoid. The clinical presentations of this neoplasm are also varied. This review summarizes the published literature on GCC of the appendix. The focus is on its diagnosis, histopathological aspects, clinical manifestations, and management.

Methods

Published studies in the English language between 1966 to 2004 were identified through Medline keyword search utilizing terms "goblet cell carcinoid," "adenocarcinoid", "mucinous carcinoid" and "crypt cell carcinoma" of the appendix.

Results

Based on the review of 57 published papers encompassing nearly 600 diagnosed patients, the mean age of presentation for GCC of the appendix was 58.89 years with equal representation in both males and females. Accurate diagnosis of this neoplasm requires astute observations within an acutely inflamed appendix as this neoplasm has a prominent pattern of submucosal growth and usually lacks the formation of a well-defined tumor mass. The mesoappendix was involved in 21.64% followed by perineural involvement in 2.06%. The most common clinical presentations in order of frequency were acute appendicitis in 22.5%; asymptomatic in 5.4%; non-localized abdominal pain in 5.15% and an appendicular mass in 3.09%. The most common surgical treatment of choice was appendectomy with right hemicolectomy in 34.70% followed by simple appendectomy in 24.57%. Concomitant distant metastasis at diagnosis was present in 11.16% of patients with the ovaries being the most common site in 3.60% followed by disseminated abdominal carcinomatosis in 1.03%. Local lymph node involvement was seen in 8.76% of patients at the time of diagnosis. The reported 5-year survival ranges from 60 % to 84%. GCC's of the appendix remains a neoplasm of unpredictable biological behavior and thus warrants lifelong surveillance for recurrence of the disease upon diagnosis and successful surgical extirpation.

Conclusion

GCC of the appendix is a rare neoplasm. Due to its wide range of presentation, this tumor should be considered as a possible diagnosis in many varied situations leading to abdominal surgery. Histopathological features such as increased number of Paneth cells, increased amount of mucin secretion and presence of pancreatic polypeptide may predict a more aggressive behavior. The advocated plan of management recommended for patients with tumors that involve the adjacent caecum or with high-grade tumors with histological features such as an increased mitotic rate involve initial appendectomy with completion right hemicolectomy due to the high possibility of local recurrence with intraperitoneal seeding prior to lymph node involvement and a 20% risk of metastatic behavior. In female patients with GCC of the appendix regardless of age, bilateral salpingo-oophorectomy is advocated. In cases with obvious spread of the disease chemotherapy, mostly with 5-FU and leucovorin is advised. Cytoreductive surgery with adjuvant intraperitoneal chemotherapy can offer improved survival in cases with advanced peritoneal dissemination.  相似文献   

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To learn if an mRNA·18S rRNA interaction or a special secondary structure in the mRNA start region is essential for translation in eukaryotic cells, we constructed recombinant plasmids with the SV40 early promoter 5 to part of the Escherichia coli tuf B-lacZ gene. Deletion of bases potentially complementary to the 18S rRNA highly increased the transient -galactosidase expressed in transfected CHO cells. Deletion of bases that fostered formation of potential hairpins with the mRNA 5-terminus or altered the structure of the coding region reduced -galactosidase activity suggesting that these features of the mRNA secondary structure may be essential for initiation of translation. Computer aided analysis of the potential structure of 290 mRNAs suggests these are conserved features of the initiation region.  相似文献   

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Processes associated with late events of N-glycosylation within the plant Golgi complex are a major limitation to the use of plant-based systems to produce recombinant pharmaceutical proteins for parenteral administration. Specifically, sugars added to the N-glycans of a recombinant protein during glycan maturation to complex forms (e.g. β1,2 xylose and α1,3 fucose) can render the product immunogenic. In order to avoid these sugars, the human enzyme α-L-iduronidase (IDUA, EC 3.2.1.76), with a C-terminal ER-retention sequence SEKDEL, was expressed in seeds of complex-glycan-deficient (cgl) mutant and wild-type (Col-0) Arabidopsis thaliana, under the control of regulatory (5'-, signal-peptide-encoding-, and 3'-) sequences from the arcelin 5-I gene of Phaseolus vulgaris (cgl-IDUA-SEKDEL and Col-IDUA-SEKDEL, respectively). The SEKDEL motif had no adverse effect on the specific activity of the purified enzyme. Surprisingly, the majority of the N-glycans of Col-IDUA-SEKDEL were complex N-glycans (i.e. contained xylose and/or fucose) (88 %), whereas complex N-glycans comprised a much lower proportion of the N-glycans of cgl-IDUA-SEKDEL (26 %), in which high-mannose forms were predominant. In contrast to the non-chimeric IDUA of cgl seeds, which is mainly secreted into the extracellular spaces, the addition of the SEKDEL sequence to human recombinant IDUA expressed in the same background led to retention of the protein in ER-derived vesicles/compartments and its partial localization in protein storage vacuoles. Our data support the contention that the use of a C-terminal ER retention motif as an effective strategy to prevent or reduce complex N-glycan formation, is protein specific.  相似文献   

10.
Few actors have had a greater impact on the “framing of Muslims” as a social and political “problem” in Norway since 2001 than Hege Storhaug of the government- and corporate billionaire funded civil society organization Human Rights Service (HRS). Using the methodological tools of the “rhetorical branch” of Critical Discourse Analysis (CDA), and applying the Aristotelian concepts of ethos, logos and pathos, we analyze the bestselling popular title on Islam and Muslims ever published in Norway, namely Storhaug’s self-published 2015 title “Islam – The Eleventh Plague”. We argue that Storhaug’s popular success must be understood in light of her rhetorical appeals to femonationalism, the critique of religion and “Enlightenment” values. We show how she in her writings incites fear of the Muslim “Other” through specific rhetorical devices and a positioning of herself as a defender of the “nation” and the “people” – against national and international “elites”.  相似文献   

11.
Females of several lizard species modify their body temperature during pregnancy, probably in connection with the optimisation of hatchling phenotypes. We studied variations in the temperature selected by gravid females compared with those selected by males and non-gravid females in an oviparous population of Zootoca vivipara (Jacquin, 1797) (Squamata: Lacertidae) of Northern Spain and examined the effects of incubation temperature on the phenotypic variation of hatchlings. Cloacal temperatures of gravid females active in the field were lower than those of males and non-gravid females, as well as the temperatures selected in a thermal gradient created in the laboratory (mean±s.d.: 32.33±1.27 °C for gravid females; 34.05±1.07 °C for males and non-gravid females). Effects of temperature were assessed by incubating eggs at five constant temperatures (21, 25, 29, 32 and 34 °C). Incubation time decreased as temperature increased, following a negative exponential function. Incubation temperatures also affected the hatchlings’ morphology: hatchlings incubated at 34 °C had shorter heads than those from other temperatures. Survival at 34 °C (58%) was significantly lower than at the other temperatures (mean 93%). Pregnant females select lower body temperature, approaching the temperatures that optimise hatchling phenotypes, according to predictions of the maternal manipulation hypothesis on the evolution of viviparity. The shift in preferred temperature by pregnant females would result in only a very short delay, if any, of hatching time and, because the temperature selected by pregnant females is much higher than average temperatures recorded in natural nests of Z. vivipara, egg retention considerably shortens incubation time, according to predictions of the cold-climate hypothesis. Our experimental results indicate that the two main hypotheses on the evolution of viviparity are compatible in our study model.  相似文献   

12.
Fibrillar aggregates of the islet amyloid polypeptide (IAPP) and amyloid-β (Aβ) are known to deposit at pancreatic β-cells and neuronal cells and are associated with the cell degenerative diseases type-2 diabetes mellitus (T2DM) and Alzheimer's disease (AD), respectively. Since IAPP is secreted by β-cells and a membrane-damaging effect of IAPP has been discussed as a reason for β-cell dysfunction and the development of T2DM, studies of the interaction of IAPP with the β-cell membrane are of high relevance for gaining a molecular-level understanding of the underlying mechanism. Recently, it has also been shown that patients suffering from T2DM exhibit an increased risk to develop AD and vice versa, and a molecular link between AD and T2DM has been suggested. In this study, membrane lipids from the rat insulinoma-derived INS-1E β-cell line were isolated, and their interaction with the amyloidogenic peptides IAPP and Aβ and a mixture of both peptides has been studied. To yield insight into the associated peptides' conformational changes and their effect on the membrane integrity during aggregation, we have carried out attenuated total reflection Fourier transform infrared spectroscopy, fluorescence microscopy, and atomic force microscopy experiments. The IAPP-Aβ heterocomplexes formed were shown to adsorb, aggregate, and permeabilize the isolated β-cell membrane significantly slower than pure IAPP, however, at a rate that is much faster than that of pure Aβ. In addition, it could be shown that isolated β-cell membranes cause similar effects on the kinetics of IAPP and IAPP-Aβ fibril formation as anionic heterogeneous model membranes.  相似文献   

13.
Phosphatidylglycerol (PG) was synthesized from several phosphatidylcholines (PCs) via phospholipase D (PLD)-catalyzed transphosphatidylation in an aqueous system. The yield of PG were 71 and 68 mol% from soybean PC and egg yolk PC, respectively, under the optimum reaction conditions of 50 μmol PC, 10 mmol glycerol, 3 ml of acetate buffer, 1.6 U PLD, and 30 μmol CaCl2 at 37°C for 48 h. In case of salmon roe PC with 14.3% eicosapentaenoic acid and 26.8% docosahexaenoic acid, the PG yield increased to 94 mol% by addition of 46 μmol α-tocopherol, although the PG yield was only 10% in absence of α-tocopherol.  相似文献   

14.
In the present work, we provide compelling evidence for the expression of a ghrelin-like peptide hormone that has only been associated with animals, in various plant tissues. Ghrelin, the appetite stimulating hormone, has been identified from a number of different species including humans, rat, pig, mouse, gerbil, eel, goldfish, bullfrog and chicken. The study here was conducted using an immunohistochemistry assay to screen whether plants have any ghrelin immunoreactivity. In this respect, Prunus x domestica L. and Marus alba were examined. Immunohistochemistry results showed that there is a strong human ghrelin immunoreactivity substance in the parenchyma cells of these plants. This was entirely unexpected since this hormone was considered to be present solely in animals. Thus, this study is the first to report the presence of a peptide with ghrelin-like activity in plants, a finding that has only been observed in the animal kingdom. RIA analysis confirmed that these plants contain significant amounts of this substance. Furthermore, reverse-phase HPLC analyses of plant extracts showed an elution characteristic of the peptide identical to that of human ghrelin. In general, fruit from both plants had higher levels of the peptide than the vegetative parts.  相似文献   

15.
It was found that calcitonin (porcine) at the dose: 4 I.U. MRC./kg/hr (i.v.), in the rabbit, increased the diuresis and oxmolal excretion, and simultaneously decreased free-water reabsorption and urinary osmolality. The results suggest that calcitonin acts by inhibiting sodium reabsorption in the ascending limb of Henl's loop. This hypothesis was confirmed by renal autoradiography study with 22Na.  相似文献   

16.
Interviews are an excellent source of information for historians of science. They should be done by historians who understand science in detail and, if possible, better than the scientists they interview. In the case of applied industrial or governmental sciences, historians must have detailed knowledge of economic or historic sources. Again they should know more in these areas than those they interview. If, on the contrary, the interviewers are not scientists at heart who know science, the history they write will become at best literature but at worst pseudoscientific abracadabra.  相似文献   

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Seasonal dynamics of suspended minerals, organic matter, particulate, and dissolved organic carbon (DOC), chlorophyll, and their vertical fluxes were studied in a small Arctic fjord (Adventfjorden, Spitsbergen) from November 2006 to October 2007. The fjord was usually covered with fast ice in winter, but remained open throughout the year since 2005. The open-water winter period caused increased wave action and resuspension of organic and mineral particles. The lack of sea-ice in spring accelerated the onset of the productive season. The earlier light signal also caused an earlier appearance of mesozooplanktonic organisms, accompanied by a significant increase of the DOC pool in the water. In the cold period (winter and spring) 47% of the annual organic matter settled on the sampling site, a lot coming from the spring diatom bloom in April. Summer melt (July, August) resulted in turbid and brackish fjord surface water with stratification and increase of both suspended particles and sedimentation, causing 60% of the annual minerals and 53% of the annual organic matter to settle at the sampling site. Increased dissolved organic carbon (DOC) through sloppy feeding on the mixo- and heterotrophic protista by the abundant mesozooplankton indicated intensive secondary production, resulting in a maximum fecal pellets flux of >5 mg C m−2 day−1. A warmer climate with reduced sea-ice cover in fjords will advance the onset of the spring bloom and will also result in a larger input of turbid melt water in summer, restricting the light availability and enhancing flocculation and thereby sedimentation.  相似文献   

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