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排序方式: 共有130条查询结果,搜索用时 421 毫秒
1.
R H Ward B Modell M Petrou F Karag?zlu E Douratsos 《BMJ (Clinical research ed.)》1983,286(6377):1542-1544
Samples of chorionic villi were obtained in the first trimester by aspiration using a cannula passed transcervically under the guidance of real time ultrasound. In initial studies in 47 anaesthetised patients immediately before therapeutic abortion a method was developed giving a success rate of 89%. In 10 patients successful sampling was performed as an outpatient procedure without anaesthesia. In all, seven diagnostic procedures were undertaken and four of the five unaffected pregnancies continued. The technique of chorionic villous sampling using real time ultrasound is simple to learn and yields material for biochemical analysis and chromosomal study without the need for tissue culture. The exact obstetric risk, however, remains to be defined. 相似文献
2.
Olivia Sackett Katherina Petrou Brian Reedy Ross Hill Martina Doblin John Beardall Peter Ralph Philip Heraud 《The ISME journal》2016,10(2):416-426
Diatoms, an important group of phytoplankton, bloom annually in the Southern Ocean, covering thousands of square kilometers and dominating the region''s phytoplankton communities. In their role as the major food source to marine grazers, diatoms supply carbon, nutrients and energy to the Southern Ocean food web. Prevailing environmental conditions influence diatom phenotypic traits (for example, photophysiology, macromolecular composition and morphology), which in turn affect the transfer of energy, carbon and nutrients to grazers and higher trophic levels, as well as oceanic biogeochemical cycles. The paucity of phenotypic data on Southern Ocean phytoplankton limits our understanding of the ecosystem and how it may respond to future environmental change. Here we used a novel approach to create a ‘snapshot'' of cell phenotype. Using mass spectrometry, we measured nitrogen (a proxy for protein), total carbon and carbon-13 enrichment (carbon productivity), then used this data to build spectroscopy-based predictive models. The models were used to provide phenotypic data for samples from a third sample set. Importantly, this approach enabled the first ever rate determination of carbon productivity from a single time point, circumventing the need for time-series measurements. This study showed that Chaetoceros simplex was less productive and had lower protein and carbon content during short-term periods of high salinity. Applying this new phenomics approach to natural phytoplankton samples could provide valuable insight into understanding phytoplankton productivity and function in the marine system. 相似文献
3.
D Mourelatos C Petrou L Boutis A Papageorgiou P Catsoulacos J Dozi-Vassiliades 《Mutation research》1987,190(3):205-210
The effect of modified steroids, containing alkylating agents, on SCE rates and on cell kinetics in cultured human lymphocytes was studied. The homo-aza-steroidal ester of p-bis(2-chloroethyl)aminophenylacetic acid (ASE) was found to be the most effective in causing markedly increased SCE rates and cell division delays. The androsterone ester of p-bis(2-chloroethyl)aminophenylacetic acid (AE-CAPA) was found to be next in order of effectiveness with the lactone ester (LE-CAPA), chlorambucil ester 3 beta-hydroxy-13a-amino-13,17-seco-5a-androstan-17-oic-13,17-lactam (CBC-HAAL) and chlorambucil (CBC) following. p-Bis(2-chloroethyl)aminophenylacetic acid (CAPA) had only a small effect and 3 beta-hydroxy-13a-amino-13,17-seco-5a-androstan-17-oic-13,17-lactam (HAAL) had no effect at all. A correlation between potency for SCE induction, effectiveness in cell division delay and previously established antitumor activity of these drugs was observed. 相似文献
4.
5.
Yoji Hara Panos Ioannou Anthi Drousiotou Goula Stylianidou Violetta Anastasiadou Kunihiko Suzuki 《Human genetics》1994,94(2):136-140
Sandhoff disease occurs in the Christian Maronite community in Cyprus, a community that established over a thousand years ago. Nowadays, this community comprises less than 1% of the whole population, and has been culturally and socially isolated. Cultured fibroblasts from a patient from this inbred group showed a -hexosaminidase subunit mRNA of apparently the normal size but of reduced quantity. A mutational analysis of cDNA obtained by polymerase chain reaction amplification of mRNA showed a deletion of A at nt 76 (counted from A of the initiation codon, ATG). The deletion results in a frame shift and a premature termination within 20 amino acids from the N-terminus of the normal mature enzyme protein. The patient was homozygous for the deletion. The 5-end of the gene showed many discrepancies from the previously published sequence. We consider that these differences are probably polymorphisms of little functional significance, because the patient's fibroblasts generate decreased but stable mRNA and because some of these base changes were also found in the genes from control fibroblasts. An extensive evaluation of the prevalence of this mutant allele in this community is being initiated. 相似文献
6.
B. Modell M. Petrou M. Layton L. Varnavides C. Slater R. H. Ward C. Rodeck K. Nicolaides S. Gibbons A. Fitches J. Old 《BMJ (Clinical research ed.)》1997,315(7111):779-784
OBJECTIVES: To audit services for prenatal diagnosis for haemoglobin disorders in the United Kingdom. DESIGN: Comparison of the annual number of cases recorded in a United Kingdom register of prenatal diagnoses for haemoglobin disorders, with the annual number of pregnancies at risk of these disorders, by ethnic group and regional health authority. The number of pregnancies at risk was estimated using data on ethnic group from the 1991 census and data from the United Kingdom thalassaemia register, which records the number of babies born with thalassaemia. SETTING: The three national prenatal diagnosis centres for haemoglobin disorders. SUBJECTS: 2068 cases of prenatal diagnosis for haemoglobin disorders in the United Kingdom from 1974 to 1994. MAIN OUTCOME MEASURES: Utilisation of prenatal diagnosis by risk, ethnic group, and regional health authority. Proportion of referrals in the first trimester and before the birth of any affected child. RESULTS: National utilisation of prenatal diagnosis for haemoglobin disorders was around 20%. During the past 10 years it has remained steady at about 50% for thalassaemias and risen from 7% to 13% for sickle cell disorders. Utilisation for sickle cell disorders varies regionally from 2% to 20%. Utilisation for thalassaemias varies by ethnic group. It is almost 90% for Cypriots and ranges regionally for British Pakistanis from 0% to over 60%. About 60% of first prenatal diagnoses are done for couples without an affected child. Less than 50% of first referrals are in the first trimester. CONCLUSIONS: National utilisation of prenatal diagnosis for haemoglobin disorders is far lower than expected, and there are wide regional variations. A high proportion of referrals are still in the second trimester and after the birth of an affected child. The findings point to serious shortcomings in present antenatal screening practice and in local screening policies and to inadequate counselling resources, especially for British Pakistanis. 相似文献
7.
ABSTRACT: INTRODUCTION: Adenoid cystic cancer of the breast is a rare condition, and even rarer are the cases where it is histologically mixed with other variants of cancer within a single lesion. In this report, one of the few cases of mixed adenoid cystic breast cancer intermingled with the infiltrating ductal variant is presented. A subsequent review of the relevant literature presents the existing experience in treating mixed breast cancers with adenoid cystic components with regard to diagnosis, treatment, and prognosis. CASE PRESENTATION: We describe a case of mixed adenoid cystic cancer of the breast with infiltrating ductal carcinoma in a 67-year-old Caucasian woman who underwent mastectomy with sentinel node biopsy. CONCLUSION: Surgery remains the cornerstone of treatment of these patients, and radiotherapy is administered when breast-conserving treatment is undertaken or a large tumor with affected lymph nodes is present. Hormonal treatment does not have a role, as estrogen receptors are always absent from both tumor components. Chemotherapy is nearly always administered on the basis of estrogen receptor and progesterone negativity and the more aggressive potential of the non-adenoid cystic component. The de-differentiation of an indolent type of cancer to a more aggressive one may affect the prognosis. 相似文献
8.
Lauren F. Messer Martin Ostrowski Martina A. Doblin Katherina Petrou Mark E. Baird Timothy Ingleton Andrew Bissett Jodie Van de Kamp Tiffanie Nelson Ian Paulsen Levente Bodrossy Jed A. Fuhrman Justin R. Seymour Mark V. Brown 《Global Change Biology》2020,26(10):5613-5629
Western boundary currents (WBCs) redistribute heat and oligotrophic seawater from the tropics to temperate latitudes, with several displaying substantial climate change‐driven intensification over the last century. Strengthening WBCs have been implicated in the poleward range expansion of marine macroflora and fauna, however, the impacts on the structure and function of temperate microbial communities are largely unknown. Here we show that the major subtropical WBC of the South Pacific Ocean, the East Australian Current (EAC), transports microbial assemblages that maintain tropical and oligotrophic (k‐strategist) signatures, to seasonally displace more copiotrophic (r‐strategist) temperate microbial populations within temperate latitudes of the Tasman Sea. We identified specific characteristics of EAC microbial assemblages compared with non‐EAC assemblages, including strain transitions within the SAR11 clade, enrichment of Prochlorococcus, predicted smaller genome sizes and shifts in the importance of several functional genes, including those associated with cyanobacterial photosynthesis, secondary metabolism and fatty acid and lipid transport. At a temperate time‐series site in the Tasman Sea, we observed significant reductions in standing stocks of total carbon and chlorophyll a, and a shift towards smaller phytoplankton and carnivorous copepods, associated with the seasonal impact of the EAC microbial assemblage. In light of the substantial shifts in microbial assemblage structure and function associated with the EAC, we conclude that climate‐driven expansions of WBCs will expand the range of tropical oligotrophic microbes, and potentially profoundly impact the trophic status of temperate waters. 相似文献
9.
Anthi Katsiarimpa Kamila Kalinowska Franziska Anzenberger Corina Weis Maya Ostertag Chie Tsutsumi Claus Schwechheimer Frédéric Brunner Ralph Hückelhoven Erika Isono 《The Plant cell》2013,25(6):2236-2252
In eukaryotes, posttranslational modification by ubiquitin regulates the activity and stability of many proteins and thus influences a variety of developmental processes as well as environmental responses. Ubiquitination also plays a critical role in intracellular trafficking by serving as a signal for endocytosis. We have previously shown that the Arabidopsis thaliana ASSOCIATED MOLECULE WITH THE SH3 DOMAIN OF STAM3 (AMSH3) is a deubiquitinating enzyme (DUB) that interacts with ENDOSOMAL COMPLEX REQUIRED FOR TRANSPORT-III (ESCRT-III) and is essential for intracellular transport and vacuole biogenesis. However, physiological functions of AMSH3 in the context of its ESCRT-III interaction are not well understood due to the severe seedling lethal phenotype of its null mutant. In this article, we show that Arabidopsis AMSH1, an AMSH3-related DUB, interacts with the ESCRT-III subunit VACUOLAR PROTEIN SORTING2.1 (VPS2.1) and that impairment of both AMSH1 and VPS2.1 causes early senescence and hypersensitivity to artificial carbon starvation in the dark similar to previously reported autophagy mutants. Consistent with this, both mutants accumulate autophagosome markers and accumulate less autophagic bodies in the vacuole. Taken together, our results demonstrate that AMSH1 and the ESCRT-III-subunit VPS2.1 are important for autophagic degradation and autophagy-mediated physiological processes. 相似文献
10.
P. Petrou 《Plant biosystems》2013,147(3):522-533
Abstract The present study was carried out in abandoned fields in central Cyprus. The main objective was to examine the impact of the regeneration environment on the establishment and survival of Pinus brutia seedlings. Sixty-four permanent plots of 16 m2 were randomly established in two distinct sites. Four regeneration environments were recorded: (a) bare soil under the crown of a P. brutia tree, (b) soil under the canopy of a P. brutia tree and low shrubs, (c) bare soil in open areas, and (d) soil under the canopy of low shrubs in open areas. All P. brutia seedlings were classified in categories according to their regeneration environment. In all plots, the density of the P. brutia seedlings was measured in three different seasons (spring, summer, autumn). Soil temperatures were recorded, samples of surface soil were taken and the percentage of soil organic matter was measured. The main conclusions drawn from this research were the following: (1) the mature P. brutia trees and low shrubs facilitate the establishment and especially the survival of P. brutia seedlings, as all seedlings in bare vegetation ground had died by the end of the growing season, and (2) the importance of facilitation increases as abiotic stress rises. 相似文献