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排序方式: 共有113条查询结果,搜索用时 343 毫秒
41.
AA Bozzo CA Soñez I Monedero Cobeta A Rolando MC Romanini D Cots 《Biotechnic & histochemistry》2014,89(4):296-303
The model of chronic intermittent stress by immobilization during pregnancy may produce alterations in the mechanisms that maintain adrenal gland homeostasis. In earlier investigations using this model, significant variations in plasma prolactin and corticosterone levels, and adrenal gland weights were observed. We hypothesized that chronic stress causes changes in apoptosis in the adrenal glands of pregnant rats. We identified and quantified apoptotic cells in the adrenal cortex and examined their ultrastructural characteristics using transmission electron microscopy. Adrenal glands of pregnant rats at gestation days 12, 17 and 21 were studied for control and experimental (stressed) rats. Immunolabelling techniques, stereological analysis and image quantification of adrenal gland sections were combined to determine differences in apoptosis in the different cell populations of the adrenal cortex. The apoptotic index of the experimental rats showed a significant reduction at gestation day 17, while at days 12 and 21 there were no differences from controls. Moreover, the apoptotic index of the reticular zones in control and experimental animals showed a significant increase compared to the glomerular and fascicular zones at the three gestation times studied. Chronic stress by immobilization reduced the caspase-dependent apoptotic index at gestation day 17, which may be related to variations in plasma concentrations of estrogens and prolactin. 相似文献
42.
TJS Alves GS Cruz V Wanderley-Teixeira AAC Teixeira JV Oliveira AA Correia 《Biotechnic & histochemistry》2014,89(4):245-255
The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), not only damages crops, but controlling its population also requires synthetic insecticides, which leads to selection of resistant populations and environmental contamination. Essential oils are an alternative for controlling this insect. There are few studies of the effects of these oils on the insect's reproductive system. We evaluated the effects of the long pepper, Piper hispidinervum, essential oil on the gonads of the armyworm and tested its possible influence on the fertility of this insect. Dosages of 30 and 50 mg/ml were tested in 3rd instar caterpillars using the leaf immersion method. Testes and ovarioles were collected, fixed with 10% formalin and embedded in Historesin. The sections were stained with toluidine blue and Mallory trichrome to detect connective tissue, periodic acid-Schiff to detect neutral carbohydrates, and bromophenol blue to detect proteins. We found that the long pepper essential oil affected negatively the spermatogenesis and altered the histochemistry of the ovarioles of S. frugiperda. The effects of long pepper oil suggest that it is a promising tool for controlling the armyworm pest. 相似文献
43.
Control of nematode parasites with reduced reliance on the use of anthelmintics was studied in 16 ewes with suckling twin
lambs on contaminated pasture in Denmark. Ewes and lambs were treated with albendazole at turn-out 3 May. Ewes were removed
from the groups on 26 July, and lambs were slaughtered on 11 October. The animals were allocated to 4 groups of 8 lambs and
their 4 ewes. Group TS was treated with albendazole at weeks 3, 6 and 8 after turnout and set-stocked; group TM was similarly
treated but moved to clean pasture in conjunction with the last drenching; group US was untreated and set-stocked, and group
UM was left untreated but moved to clean pasture week 8 after turn-out. Supplementary feed was offered in June and August
due to scarcity of pasture. Strategic treatments of ewes and lambs weeks 3, 6 and 8 after turn-out, with or without a move
to clean pasture, were highly effective in controlling nematode infections for most of the season. This was reflected in better
weight gains and carcass characteristics in the treated compared to untreated lambs, resulting in an average increase in the
value of the product by 36%. The effect of moving without treatment (UM) on faecal egg counts was limited but peak pasture
infectivity was reduced to less than 10% compared to the set-stocked group and weight gains of lambs were significantly better
despite poor feed availability in late season. The study showed that under set-stocked conditions repeated anthelmintic treatments
of both ewes and lambs in early season may ensure sufficient nematode control whereas moving animals to clean pasture without
dosing was less efficient. The latter may, however, still be a viable option in organic and other production systems where
routine use of anthelmintics is banned, particularly if weaning and moving are combined or a second move is performed. 相似文献
44.
R. K. Gupta D. Gaskell C. S. Dowle J. S. Simpson B. R. King S. Naran S. Lallu R. Fauck 《Cytopathology》2004,15(6):326-330
In this study a review of 1948 nipple discharge (ND) samples from 1530 patients in the age range of 18-83 years was undertaken to determine whether cytological findings from ND smears could provide useful diagnostic information regarding various breast lesions. The study included 1494 females and 36 males and was carried out during a period of 20 years 8 months. The clinical information in all patients was obtained from clinicians (coauthors), medical records and a review of biopsies in 205 patients who had undergone surgery following the cytodiagnosis. Of the ND samples examined, 1480 were unilateral while 468 were from 234 bilateral ND. The cytodiagnoses were: benign 624, inadequate (despite two to three repeat samples) 492, inflammatory 96, papillary lesion not otherwise specified (NOS) 229, suspicious 22 (21 females, one male) and malignant 67 (63 females, four males). A breast biopsy in the 22 suspicious cases revealed breast carcinoma in 18 cases (females n = 17, male n = 1), atypical ductal hyperplasia (female n = 1), fibroadenoma (female n = 1) and a papilloma in two females. In the 67 cases with a diagnosis of malignancy 65 revealed a breast carcinoma in the biopsy (female n = 62, male n = 3) while one female was diagnosed as fibroadenoma and one male as florid gynaecomastia. In 63 cases (females n = 61; males n = 2) with clinical lumpy areas consistent with the diagnosis of fibrocystic condition in ND, the biopsy confirmed a fibrocystic process. In 53 of 229 cases with ND findings suggestive of a papillary lesion (NOS) the biopsy revealed a papilloma in 41 cases while in 12 cases no lesion was found. In the remaining cases of all the groups only a clinical follow-up and appropriate investigations were performed with no untoward outcome. Based on our study it is felt that cytological examination of ND smears seems to be a reasonably specific method in the diagnosis of malignant and suspicious cases but may be somewhat less specific for other diagnoses. 相似文献
45.
Gert-Jan Jeunen Eddy Dowle Jonika Edgecombe Ulla von Ammon Neil J. Gemmell Hugh Cross 《Molecular ecology resources》2023,23(3):725-738
The measurement of biodiversity is an integral aspect of life science research. With the establishment of second- and third-generation sequencing technologies, an increasing amount of metabarcoding data is being generated as we seek to describe the extent and patterns of biodiversity in multiple contexts. The reliability and accuracy of taxonomically assigning metabarcoding sequencing data have been shown to be critically influenced by the quality and completeness of reference databases. Custom, curated, eukaryotic reference databases, however, are scarce, as are the software programs for generating them. Here, we present crabs (Creating Reference databases for Amplicon-Based Sequencing), a software package to create custom reference databases for metabarcoding studies. crabs includes tools to download sequences from multiple online repositories (i.e., NCBI, BOLD, EMBL, MitoFish), retrieve amplicon regions through in silico PCR analysis and pairwise global alignments, curate the database through multiple filtering parameters (e.g., dereplication, sequence length, sequence quality, unresolved taxonomy, inclusion/exclusion filter), export the reference database in multiple formats for immediate use in taxonomy assignment software, and investigate the reference database through implemented visualizations for diversity, primer efficiency, reference sequence length, database completeness and taxonomic resolution. crabs is a versatile tool for generating curated reference databases of user-specified genetic markers to aid taxonomy assignment from metabarcoding sequencing data. crabs can be installed via docker and is available for download as a conda package and via GitHub ( https://github.com/gjeunen/reference_database_creator ). 相似文献
46.
The fine needle aspiration (FNA) cytologic evaluation of 6,941 lesions of the breast was reviewed, with an emphasis on the cytodiagnosis of colloid carcinoma. The most common benign breast diseases in this series were fibroadenomas, cysts and fibrocystic conditions. All cases with an FNA diagnosis of suspicious were biopsied; a number of these were found to be carcinoma of the breast. In cases with an FNA diagnosis of carcinoma of the breast, a plan of management was immediately adopted on the basis of that diagnosis. Thirteen cases of colloid (mucinous) carcinoma of the breast were diagnosed by FNA cytology; in all, the cytodiagnosis was confirmed by the subsequent histologic diagnosis. The distinctive cytologic criteria that may be useful for making an FNA diagnosis of colloid carcinoma of the breast are discussed, and the FNA differences between the pure and mixed types of colloid carcinoma are noted. 相似文献
47.
48.
Schmidt K Marx A de Graaf AA Wiechert W Sahm H Nielsen J Villadsen J 《Biotechnology and bioengineering》1998,58(2-3):254-257
Conventional metabolic flux analysis uses the information gained from determination of measurable fluxes and a steady-state assumption for intracellular metabolites to calculate the metabolic fluxes in a given metabolic network. The determination of intracellular fluxes depends heavily on the correctness of the assumed stoichiometry including the presence of all reactions with a noticeable impact on the model metabolite balances. Determination of fluxes in complex metabolic networks often requires the inclusion of NADH and NADPH balances, which are subject to controversial debate. Transhydrogenation reactions that transfer reduction equivalents from NADH to NADPH or vice versa can usually not be included in the stoichiometric model, because they result in singularities in the stoichiometric matrix. However, it is the NADPH balance that, to a large extent, determines the calculated flux through the pentose phosphate pathway. Hence, wrong assumptions on the presence or activity of transhydrogenation reactions will result in wrong estimations of the intracellular flux distribution. Using 13C tracer experiments and NMR analysis, flux analysis can be performed on the basis of only well established stoichiometric equations and measurements of the labeling state of intracellular metabolites. Neither NADH/NADPH balancing nor assumptions on energy yields need to be included to determine the intracellular fluxes. Because metabolite balancing methods and the use of 13C labeling measurements are two different approaches to the determination of intracellular fluxes, both methods can be used to verify each other or to discuss the origin and significance of deviations in the results. Flux analysis based entirely on metabolite balancing and flux analysis, including labeling information, have been performed independently for a wild-type strain of Aspergillus oryzae producing alpha-amylase. Two different nitrogen sources, NH4+ and NO3-, have been used to investigate the influence of the NADPH requirements on the intracellular flux distribution. The two different approaches to the calculation of fluxes are compared and deviations in the results are discussed. Copyright 1998 John Wiley & Sons, Inc. 相似文献
49.
50.
Multisite tyrosine phosphorylation of the N‐terminus of Mint1/X11α by Src kinase regulates the trafficking of amyloid precursor protein
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