文蛤吸虫寄生病引起组织异变情况及其防治的探讨

文蛤,是一种经济价值较高的海产贝类。其肉味鲜美,营养丰富,蛋白质含量为10％,脂肪1.2％,碳水化合物2.5％,还有大量的钙、磷、铁、维生素等,除食用外还具有药用价值,堪称蛤中上品。而近年来,文蛤吸虫病日益严重,制约了贝类养殖生产的发展。吸虫的寄生不仅降低了宿主贝类的肥满度,影响其繁殖力,严重者还可导致贝类死亡。本文结合文蛤吸虫寄生病流行病学的调查,开展了文蛤吸虫病的病理学研究,并据此提出了几条防治措施。

Characterization of hot deformation and microstructure evolution of a new metastableβtitanium alloy

The hot deformation characteristics of as-forged Ti−3.5Al−5Mo−6V−3Cr−2Sn−0.5Fe−0.1B−0.1C alloy within a temperature range from 750 to 910℃and a strain rate range from 0.001 to 1 s^(-1) were investigated by hot compression tests.The stress−strain curves show that the flow stress decreases with the increase of temperature and the decrease of strain rate.The microstructure is sensitive to deformation parameters.The dynamic recrystallization(DRX)grains appear while the temperature reaches 790℃at a constant strain rate of 0.001 s^(-1) and strain rate is not higher than 0.1 s^(-1) at a constant temperature of 910℃.The work-hardening rateθis calculated and it is found that DRX prefers to happen at high temperature and low strain rate.The constitutive equation and processing map were obtained.The average activation energy of the alloy is 242.78 kJ/mol and there are few unstable regions on the processing map,which indicates excellent hot workability.At the strain rate of 0.1 s^(-1),the stress−strain curves show an abnormal shape where there are two stress peaks simultaneously.This can be attributed to the alternation of hardening effect,which results from the continuous dynamic recrystallization(CDRX)and the rotation of DRX grains,and dynamic softening mechanism.

Transcription analysis of peloric mutants of Phalaenopsis orchids derived from tissue culture

Tissue culture has been widely used for mass propagation of Phalaenopsis. However, somaclonal variation occurred during micropropagation process posed a severe problem by affecting product quality. In this study, wild type and peloric flower buds of Phalaenopsis hybrids derived from flower stalk nodal culture were used for cDNA-RAPD and cDNA suppression subtractive hybridization analyses in order to study their genetic difference in terms of expressed sequence tags. A total of 209 ESTs from normal flower buds and 230 from mutants were sequenced. These ESTs sequences can be grouped into several functional categories involved in different cellular processes including metabolism, signal transduction, transcription, cell growth and division, protein synthesis, and protein localization, and into a subcat- egory of proteins with unknown function. Cymbidium mosaic virus transcript was surprisingly found expressed fre- quently in the peloric mutant of P. Little Mary. Real-time RT-PCR analysis on selected ESTs showed that in mutant flower buds, a bZIP transcription factor (TGA1a-like protein) was down-regulated, while up-regulated genes include auxin-regulated protein kinase, cyclophilin, and TCP-like genes. A retroelement clone was also preferentially expressed in the peloric mutant flowers. On the other hand, ESTs involved in DNA methylation, chromatin remodeling and post- transcriptional regulation, such as DNA methyltransferase, histone acetyltransferase, ERECTA, and DEAD/DEAH RNA helicase, were enriched in normal flower buds than the mutants. The enriched transcripts in the wild type indicate the down regulation of these transcripts in the mutants, and vice versa. The potential roles of the analyzed transcripts in the development of Phalaenopsis flowers are discussed.

Sampling variability of computer-aided fractal-corrected measures of liver fibrosis in needle biopsy specimens

AIM： TO assess the sampling variability of computeraided, fractal-corrected measures of fibrosis in liver biopsies. METHODS： Samples were derived from six to eight different parts of livers removed from 12 patients with clinically and histologically proven cirrhosis undergoing orthotopic liver transplantation. Sirius red-stained sections with a thickness of 2 μm were digitized using a computer-aided image analysis system that automatically measures the surface of fibrosis, as well as its outline perimeter, fractal surface and outline dimensions, wrinldedness, and Hurst coefficient. RESULTS： We found a high degree of inter-sample variability in the measurements of the surface [coefficient of variation （CV） = 43% ± 13%] and wrinkledness （CV = 28% ± 9%） of fibrosis, but the inter-sample variability of Hurst＇s exponent was low （CV = 14% ± 2%）. CONCLUSION： This study suggests that Hurst＇s exponent might be used in clinical practice as the best histological estimate of fibrosis in the whole organ, and evidences the fact that biopsy sections, which are fundamental for the qualitative diagnosis of chronic hepatitis, play a key role in the quantitative estimate of architectural changes in liver tissue.

Evolving management of metaplasia and dysplasia in Barrett's epithelium

Oesophageal cancer affects more than 450000 people worldwide and despite continued medical advancements the incidence of oesophageal cancer is increasing. Oesophageal cancer has a 5 year survival of 15%-25% and now globally attempts are made to more aggressively diagnose and treat Barrett's oesophagus the known precursor to invasive disease. Currently diagnosis the of Barrett's oesophagus is predominantly made after endoscopic visualisation and histopathological confirmation. Minimally invasive techniques are being developed to improve the viability of screening programs. The management of Barrett's oesophagus can vary greatly dependent on the presence and severity of dysplasia. There is no consensus between the major international medical societies to determine and agreed surveillance and intervention pathway. In this review we analysed the current literature to demonstrate the evolving management of metaplasia and dysplasia in Barrett's epithelium.

Comparison of Generic Organization of the Research Paper in English and Polish： Cross-Cultural Variation and Pedagogical Implications

This paper provides a comparative analysis of the rhetorical structure and linguistic features of research papers written in English and Polish languages within the field of medicine. The study was based on a corpus of 30 research articles： 15 written by native English speakers and 15 by non-native speakers-Polish researchers. The outcomes of this investigation indicate some discrepancies in rhetorical structure between the research papers. An explanation for the cross-cultural differences which seem to be responsible for these discrepancies, and an enumeration of pedagogical implications for the use of a corpus-based approach to generic analysis in English for Specific Purposes （ESP） classes, are also provided.

Variants of genes encoding collagens and matrix metalloproteinase system increased the risk of aortic dissection

Aortic dissection （AD） is a devastating, heterogeneous condition of aorta. The homeostasis between collagens and matrix metalloproteases （MMPs）/tissue inhibitors of MMPs （TIMPs） system in the extracellular matrix plays an important role for structure and functions of aorta. However, our knowledge on association between variants of genes in this system and pathogenesis of AD is very limited. We analyzed all yet known coding human genes of collagens （45 genes）, MMPs/TIMPs （27 genes） in 702 sporadic AD patients and in 163 matched healthy controls, by using massively targeted next-generation and Sanger sequencing. To define the pathogenesis of potential disease-causing candidate genes, we performed transcriptome sequencing and pedigree co-segregation analysis in some genes and generated Col5a2 knockout rats. We identified 257 pathogenic or likely pathogenic variants which involved 88.89% （64/72） genes in collagens-MMPs/TIMPs system and accounted for 31.05% （218/702） sporadic AD patients. In them, 84.86% patients （185/218） carried one variant, 12.84% two variants and 2.30% more than two variants. Importantly, we identified 52 novel probablY pathogenic loss-of-function （LOF） variants （20 nonsense, 16 frameshift, 14 splice sites, one stop-loss, one initiation codon） in 11.06% （50/452） AD patients, which were absent in 163 controls （P=2.5-10-5）. Transcriptome sequencing revealed that identified variants induced dyshomeostasis in expression of collagens-TIMPs/MMPs systems. The Col5a2-/- rats manifested growth retardation and aortic dysplasia. Our study provides a first comprehensive map of genetic alterations in collagens-MMPs/TIMPs system in sporadic AD patients and suggests that variants of these genes contribute largely to AD pathogenesis.

EXTERNAL AND INTERNAL CONTROL IN PLANT DEVELOPMENT

Bodies of plants are modularly organized. Development proceeds by adding new modules to open endings with a potential for branching. Each module is autonomous to some extent. Development relies on the self-organized patterns that emerge from the interactions of individual modules. Interactions include both competition and cooperation,and several types of positive and negative feedback loops are involved. Development can be open to external influences, thus enabling the plant to adjust its form to the environment,for example, to the spatial distribution of ecological resources. This paper provides a review on adaptive plasticity in plants.