151 research outputs found
Apoptosis of supraoptic AVP neurons is involved in the development of central diabetes insipidus after hypophysectomy in rats
<p>Abstract</p> <p>Background</p> <p>It has been reported that various types of axonal injury of hypothalamo-neurohypophyseal tract can result in degeneration of the magnocellular neurons (MCNs) in hypothalamus and development of central diabetes insipidus (CDI). However, the mechanism of the degeneration and death of MCNs after hypophysectomy in vivo is still unclear. This present study was aimed to disclose it and to figure out the dynamic change of central diabetes insipidus after hypophysectomy.</p> <p>Results</p> <p>The analysis on the dynamic change of daily water consumption (DWC), daily urine volume(DUV), specific gravity of urine(USG) and plasma vasopressin concentration showed that the change pattern of them was triphasic and neuron counting showed that the degeneration of vasopressin neurons began at 10 d, aggravated at 20 d and then stabilized at 30 d after hypophysectomy. There was marked upregulation of cleaved Caspase-3 expression of vasopressin neurons in hypophysectomy rats. A "ladder" pattern of migration of DNA internucleosomal fragments was detected and apoptotic ultrastructure was found in these neurons. There was time correlation among the occurrence of diabetes insipidus, the changes of plasma vasopressin concentration and the degeneration of vasopressin neurons after hypophysectomy.</p> <p>Conclusion</p> <p>This study firstly demonstrated that apoptosis was involved in degeneration of supraoptic vasopressin neurons after hypophysectomy in vivo and development of CDI. Our study on time course and correlations among water metabolism, degeneration and apoptosis of vasopressin neurons suggested that there should be an efficient therapeutic window in which irreversible CDI might be prevented by anti-apoptosis.</p
The Nbp35/ApbC homolog acts as a nonessential [4Fe-4S] transfer protein in methanogenic archaea
© 2019 Federation of European Biochemical Societies The nucleotide binding protein 35 (Nbp35)/cytosolic Fe-S cluster deficient 1 (Cfd1)/alternative pyrimidine biosynthetic protein C (ApbC) protein homologs have been identified in all three domains of life. In eukaryotes, the Nbp35/Cfd1 heterocomplex is an essential Fe-S cluster assembly scaffold required for the maturation of Fe-S proteins in the cytosol and nucleus, whereas the bacterial ApbC is an Fe-S cluster transfer protein only involved in the maturation of a specific target protein. Here, we show that the Nbp35/ApbC homolog MMP0704 purified from its native archaeal host Methanococcus maripaludis contains a [4Fe-4S] cluster that can be transferred to a [4Fe-4S] apoprotein. Deletion of mmp0704 from M. maripaludis does not cause growth deficiency under our tested conditions. Our data indicate that Nbp35/ApbC is a nonessential [4Fe-4S] cluster transfer protein in methanogenic archaea
Purification and characterization of a novel defensin from the salivary glands of the black fly, Simulium bannaense
BACKGROUND: Black flies (Diptera: Simuliidae) are haematophagous insects that can cause allergic reactions and act as vectors of pathogens. Although their saliva has been thought to contain a diverse array of physiologically active molecules, little information is available on antimicrobial factors in black fly salivary glands, especially no defensins have been reported so far. METHODS: A novel cationic defensin designated SibaDef was purified using reverse phase high-performance liquid chromatography (RP-HPLC) from the salivary glands of the black fly Simulium bannaense. The amino acid sequence of SibaDef was determined by a combination method of automated Edman degradation and cDNA sequencing. The morphologic changes of Gram-positive bacteria Staphylococcus aureus or Bacillus subtilis treated with SibaDef were assessed by scanning electron microscopy (SEM). Quantitative PCR (qPCR) was performed to analyze the expression of SibaDef mRNA in whole bodies of insects after oral infection with the bacteria S. aureus or B. subtilis. RESULTS: Surprisingly, the phylogenetic analysis of defensin-related amino acid sequences demonstrated that SibaDef is most closely related to defensins from the human body louse Pediculus humanus corporis (Anoplura: Pediculidae), rather than to other dipteran defensins. SibaDef showed potent antimicrobial activities against Gram-positive bacteria with minimal inhibitory concentrations (MICs) ranging from 0.83 μM to 2.29 μM. SEM analysis indicated that SibaDef killed microorganisms through the disruption of cell membrane integrity. The transcript levels of SibaDef in the bacteria-immunized flies increased with the time course, reaching maximum at 36 h and then slowly decreased from that time point. CONCLUSIONS: Our results indicate that SibaDef is involved in the innate humoral response of the black fly S. bannaense, and it might play a significant role in the defence against microorganisms in both sugar and blood meals
The effects of grazing and the meteorologic factors on wind-sand flux in the desert steppe
Introduction: Affected by global climate warming and changing rainfall patterns, the degree of soil desiccation in arid grasslands has increased and soil wind erosion has become a major environmental concern. Understanding and controlling the characteristics of sand flux and wind erosion caused by the degradation of grassland vegetation, as well as their changing patterns, has become a top priority in combating grassland degradation. Therefore, the aim of this study is to clarify the extent of wind erosion in desert grasslands and its influencing factors in order to provide a theoretical basis and data support for the restoration of grassland vegetation and the sustainable development of grassland livestock production.Methods: Use of SAS and Origin statistical software to perform multifactorial analysis of variance on variables such as year, stocking rate, meteorological conditions and wind-sand flux to determine the degree of influence of different factors on sand flux and the magnitude of interactions among different factors.Results and discussion: The results showed that wind-sand flux was higher when rainfall was low and stocking intensity was high. Specifically, the wind-sand flux increased by 50.3% and 83.6% in the moderate and high grazing treatments, respectively, compared to the control. The data obtained also showed that there was a significant interaction between climate and grazing intensity, suggesting that an increase in one factor may attenuate the differences in wind-sand flux at different levels of other factors. There is likely to be a threshold effect of stocking rate of moderate grazing on the variation of wind-sand flux influenced by different factors. In summary, the factors affecting wind-sand flux in the arid desert steppe are numerous and complex, with stocking rates below moderate grazing being key to reducing wind-sand flux
Heusler type CoNiGa alloys with high martensitic transformation temperature
A strong need exists to develop new kinds of high-temperature shape-memory alloys. In this study, two series of CoNiGa alloys with different compositions have been studied to investigate their potentials as high-temperature shape-memory alloys, with regard to their microstructure, crystal structure, and martensitic transformation behavior. Optical observations and X-ray diffractions confirmed that single martensite phase was present for low cobalt samples, and dual phases containing martensite and gamma phase were present for high cobalt samples. It was also found that CoNiGa alloys in this study exhibit austenitic transformation temperatures higher than 340 degrees C, showing their great potentials for developing as high-temperature shape-memory alloys
Meta-analysis of shared genetic architecture across ten pediatric autoimmune diseases
Genome-wide association studies (GWASs) have identified hundreds of susceptibility genes, including shared associations across clinically distinct autoimmune diseases. We performed an inverse χ(2) meta-analysis across ten pediatric-age-of-onset autoimmune diseases (pAIDs) in a case-control study including more than 6,035 cases and 10,718 shared population-based controls. We identified 27 genome-wide significant loci associated with one or more pAIDs, mapping to in silico-replicated autoimmune-associated genes (including IL2RA) and new candidate loci with established immunoregulatory functions such as ADGRL2, TENM3, ANKRD30A, ADCY7 and CD40LG. The pAID-associated single-nucleotide polymorphisms (SNPs) were functionally enriched for deoxyribonuclease (DNase)-hypersensitivity sites, expression quantitative trait loci (eQTLs), microRNA (miRNA)-binding sites and coding variants. We also identified biologically correlated, pAID-associated candidate gene sets on the basis of immune cell expression profiling and found evidence of genetic sharing. Network and protein-interaction analyses demonstrated converging roles for the signaling pathways of type 1, 2 and 17 helper T cells (TH1, TH2 and TH17), JAK-STAT, interferon and interleukin in multiple autoimmune diseases
Deriving overlapped cloud motion vectors based on geostationary satellite and its application on monitoring Typhoon Mulan
We present a novel Overlapped Cloud Motion Vectors (OCMVs) deriving algorithm using the Himawari-8 satellite. A multi-layer Cloud Top Heights (CTHs) retrieving model based on multi-spectral observed radiances is constructed using neural networks to reduce the substantial uncertainty of CMVs over multi-layer clouds. The retrieved CTHs are assigned to upper ice and lower water cloud layers, then they are used as respective tracers for deriving OCMVs based on an optical flow algorithm.
-The files of trainmodel1.py and trainmodel1.py are the codes for training the multi-layer Cloud Top Heights (CTHs) retrieving models;
-The six csv files concludes all the matched datasets we used in the neural network (NN ) models;
-The file of optical_fb_cwv12_mulan_save.py is the code for estimating CMVs from the multi-layer Cloud Top Heights (CTHs)
-The CTH_20220808-20220810 zip file concludes the derived CTH from the NN models during Mulan period;
-The CWV_20220808-20220810 zip file concludes the derived CWV from the NN models during Mulan period
Deriving overlapped cloud motion vectors based on geostationary satellite and its application on monitoring Typhoon Mulan
We present a novel Overlapped Cloud Motion Vectors (OCMVs) deriving algorithm using the Himawari-8 satellite. A multi-layer Cloud Top Heights (CTHs) retrieving model based on multi-spectral observed radiances is constructed using neural networks to reduce the substantial uncertainty of CMVs over multi-layer clouds. The retrieved CTHs are assigned to upper ice and lower water cloud layers, then they are used as respective tracers for deriving OCMVs based on an optical flow algorithm.
-The files of trainmodel1.py and trainmodel1.py are the codes for training the multi-layer Cloud Top Heights (CTHs) retrieving models;
-The six csv files concludes all the matched datasets we used in the neural network (NN ) models;
-The file of optical_fb_cwv12_mulan_save.py is the code for estimating CMVs from the multi-layer Cloud Top Heights (CTHs)
-The CTH_20220808-20220810 zip file concludes the derived CTH from the NN models during Mulan period;
-The CWV_20220808-20220810 zip file concludes the derived CWV from the NN models during Mulan period
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