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Bats, rodents, and shrews are the most important animal sources of human infectious diseases. However, the evolution and transmission of viruses among them remain largely unexplored. Through the meta-transcriptomic sequencing of internal organ and fecal samples from 2,443 wild bats, rodents, and shrews sampled from four Chinese habitats, we identified 669 viruses, including 534 novel viruses, thereby greatly expanding the mammalian virome. Our analysis revealed high levels of phylogenetic diversity, identified cross-species virus transmission events, elucidated virus origins, and identified cases of invertebrate viruses in mammalian hosts. Host order and sample size were the most important factors impacting virome composition and patterns of virus spillover. Shrews harbored a high richness of viruses, including many invertebrate-associated viruses with multi-organ distributions, whereas rodents carried viruses with a greater capacity for host jumping. These data highlight the remarkable diversity of mammalian viruses in local habitats and their ability to emerge in new hosts.
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An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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Emerging infectious diseases, such as severe acute respiratory syndrome (SARS) and Zika virus disease, present a major threat to public health1-3. Despite intense research efforts, how, when and where new diseases appear are still a source of considerable uncertainty. A severe respiratory disease was recently reported in Wuhan, Hubei province, China. As of 25 January 2020, at least 1,975 cases had been reported since the first patient was hospitalized on 12 December 2019. Epidemiological investigations have suggested that the outbreak was associated with a seafood market in Wuhan. Here we study a single patient who was a worker at the market and who was admitted to the Central Hospital of Wuhan on 26 December 2019 while experiencing a severe respiratory syndrome that included fever, dizziness and a cough. Metagenomic RNA sequencing4 of a sample of bronchoalveolar lavage fluid from the patient identified a new RNA virus strain from the family Coronaviridae, which is designated here 'WH-Human 1' coronavirus (and has also been referred to as '2019-nCoV'). Phylogenetic analysis of the complete viral genome (29,903 nucleotides) revealed that the virus was most closely related (89.1% nucleotide similarity) to a group of SARS-like coronaviruses (genus Betacoronavirus, subgenus Sarbecovirus) that had previously been found in bats in China5. This outbreak highlights the ongoing ability of viral spill-over from animals to cause severe disease in humans.
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Betacoronavirus/classificação , Doenças Transmissíveis Emergentes/complicações , Doenças Transmissíveis Emergentes/virologia , Infecções por Coronavirus/complicações , Infecções por Coronavirus/virologia , Pneumonia Viral/complicações , Pneumonia Viral/virologia , Síndrome Respiratória Aguda Grave/etiologia , Síndrome Respiratória Aguda Grave/virologia , Adulto , Betacoronavirus/genética , COVID-19 , China , Doenças Transmissíveis Emergentes/diagnóstico por imagem , Doenças Transmissíveis Emergentes/patologia , Infecções por Coronavirus/diagnóstico por imagem , Infecções por Coronavirus/patologia , Genoma Viral/genética , Humanos , Pulmão/diagnóstico por imagem , Masculino , Filogenia , Pneumonia Viral/diagnóstico por imagem , Pneumonia Viral/patologia , RNA Viral/genética , Recombinação Genética/genética , SARS-CoV-2 , Síndrome Respiratória Aguda Grave/diagnóstico por imagem , Síndrome Respiratória Aguda Grave/patologia , Tomografia Computadorizada por Raios X , Sequenciamento Completo do GenomaRESUMO
MicroRNAs (miRNAs) are small non-coding RNAs (typically consisting of 18-25 nucleotides) that negatively control expression of target genes at the post-transcriptional level. Owing to the biological significance of miRNAs, miRTarBase was developed to provide comprehensive information on experimentally validated miRNA-target interactions (MTIs). To date, the database has accumulated >13,404 validated MTIs from 11,021 articles from manual curations. In this update, a text-mining system was incorporated to enhance the recognition of MTI-related articles by adopting a scoring system. In addition, a variety of biological databases were integrated to provide information on the regulatory network of miRNAs and its expression in blood. Not only targets of miRNAs but also regulators of miRNAs are provided to users for investigating the up- and downstream regulations of miRNAs. Moreover, the number of MTIs with high-throughput experimental evidence increased remarkably (validated by CLIP-seq technology). In conclusion, these improvements promote the miRTarBase as one of the most comprehensively annotated and experimentally validated miRNA-target interaction databases. The updated version of miRTarBase is now available at http://miRTarBase.cuhk.edu.cn/.
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Bases de Dados de Ácidos Nucleicos , MicroRNAs/metabolismo , MicroRNA Circulante/metabolismo , Mineração de Dados , Regulação da Expressão Gênica , RNA Mensageiro/metabolismo , Interface Usuário-ComputadorRESUMO
Acyl-CoA binding domain containing 3 (ACBD3) is involved in the maintenance of Golgi structure and function through its interaction with the integral membrane protein. However, the clinical significance and biological role of ACBD3 in breast cancer remain unclear. Herein, we found that the mRNA and protein levels of ACBD3 were markedly up-regulated in breast cancer cells and tissues. Immunohistochemical analysis of breast cancer tissues demonstrated that ACBD3 overexpression was significantly associated with advanced clinicopathological features. Univariate and multivariate analysis indicated that ACBD3 overexpression correlates with poor prognosis in breast cancer. Furthermore, overexpressing ACBD3 promoted, while silencing ACBD3 inhibited, self-renewal and tumorigenesis in breast cancer cells in vitro and in vivo respectively. Importantly, upregulating ACBD3 promoted the self-renewal and tumorigenesis of breast cancer cells via activating the Wnt/beta-catenin signaling, and the pro-self-renewal effect of ACBD3 in breast cancer was antagonized by the Wnt signaling inhibitor TCF4-siRNA and Lef1-siRNA.These findings indicate that ACBD3 may represent candidate therapeutic targets to enable the elimination of breast cancer stem cells, providing the preclinical proof-of-concept for the prevention and treatment of breast cancer.
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Proteínas Adaptadoras de Transdução de Sinal/genética , Neoplasias da Mama/genética , Proliferação de Células/fisiologia , Transformação Celular Neoplásica/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Proteínas de Membrana/genética , Acil Coenzima A/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Transformação Celular Neoplásica/patologia , Humanos , Proteínas de Membrana/metabolismo , Prognóstico , Ativação Transcricional/fisiologia , Regulação para Cima , Via de Sinalização Wnt/fisiologia , beta Catenina/genética , beta Catenina/metabolismoRESUMO
A new apiose-containing kaempferol trioside, kaempferol-3-O-α-L-rhamnosyl-(1â´ â 6â³)-O-ß-D-galactopyranosyl-7-O-ß-D-apiofuranoside, along with 16 known compounds, were isolated from 50% acetone extract of Silphium perfoliatum L. Their structures were elucidated by acid hydrolysis and spectroscopic techniques including UV, IR, MS, ¹H, ¹³C, and 2D-NMR. In addition, the pharmacological activity of compound 1 was tested with HepG2 and Balb/c mice (splenic lymphocytes and thymic lymphocytes) in vitro, and it exhibited inhibitory effect on the proliferation of HepG2 cells and showed the immunosuppressive activity.
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Asteraceae/química , Medicamentos de Ervas Chinesas/isolamento & purificação , Glicosídeos/isolamento & purificação , Imunossupressores/isolamento & purificação , Quempferóis/isolamento & purificação , Animais , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Glicosídeos/química , Glicosídeos/farmacologia , Células Hep G2 , Humanos , Imunossupressores/química , Imunossupressores/farmacologia , Quempferóis/química , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Molecular , Ressonância Magnética Nuclear BiomolecularRESUMO
Despite extensive scientific efforts directed toward the evolutionary trajectory of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in humans at the beginning of the COVID-19 epidemic, it remains unclear how the virus jumped into and evolved in humans so far. Herein, we recruited almost all adult coronavirus disease 2019 (COVID-19) cases appeared locally or imported from abroad during the first 8 months of the outbreak in Shanghai. From these patients, SARS-CoV-2 genomes occupying the important phylogenetic positions in the virus phylogeny were recovered. Phylogenetic and mutational landscape analyses of viral genomes recovered here and those collected in and outside of China revealed that all known SARS-CoV-2 variants exhibited the evolutionary continuity despite the co-circulation of multiple lineages during the early period of the epidemic. Various mutations have driven the rapid SARS-CoV-2 diversification, and some of them favor its better adaptation and circulation in humans, which may have determined the waxing and waning of various lineages.
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BACKGROUND: SARS-CoV-2 continues to mutate over time, and reports on children infected with Omicron BA.5 are limited. We aimed to analyze the specific symptoms of Omicron-infected children and to improve patient care. METHODS: We selected 315 consecutively hospitalized children with Omicron BA.5 and 16,744 non-Omicron-infected febrile children visiting the fever clinic at our hospital between December 8 and 30, 2022. Specific convulsions and body temperatures were compared between the two cohorts. We analyzed potential associations between convulsions and vaccination, and additionally evaluated the brain damage among severe Omicron-infected children. RESULTS: Convulsion rates (97.5% vs. 4.3%, P < 0.001) and frequencies (median: 2.0 vs. 1.6, P < 0.001) significantly differed between Omicron-infected and non-Omicron-infected febrile children. The body temperatures of Omicron-infected children were significantly higher during convulsions than when they were not convulsing and those of non-Omicron-infected febrile children during convulsions (median: 39.5 vs. 38.2 and 38.6 °C, both P < 0.001). In the three Omicron-subgroups, the temperature during convulsions was proportional to the percentage of patients and significantly differed ( P < 0.001), while not in the three non-Omicron-subgroups ( P = 0.244). The convulsion frequency was lower in the 55 vaccinated children compared to the 260 non-vaccinated children (average: 1.8 vs. 2.1, P < 0.001). The vaccination dose and convulsion frequency in Omicron-infected children were significantly correlated ( P < 0.001). Fifteen of the 112 severe Omicron cases had brain damage. CONCLUSIONS: Omicron-infected children experience higher body temperatures and frequencies during convulsions than those of non-Omicron-infected febrile children. We additionally found evidence of brain damage caused by infection with omicron BA.5. Vaccination and prompt fever reduction may relieve symptoms.
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COVID-19 , Convulsões , Humanos , COVID-19/complicações , COVID-19/epidemiologia , Masculino , Feminino , Convulsões/etiologia , Pré-Escolar , Criança , Lactente , Hospitalização/estatística & dados numéricos , Estudos de Coortes , SARS-CoV-2 , Temperatura Corporal , FebreRESUMO
OBJECTIVE: To compare the effects of different concentrations of linolenin on inhibiting apoptosis of chondrocytes in the growth plate, and to screen the optimal concentration of linolenin, so as to provide theoretical support for delaying epiphyseal closure and promoting long bone growth in rats. METHODS: Two 4-week-old male SD rats (SPF grade) with a body mass of 80 g were selected. The growth plate cartilage of rat tibia and femur was dissected and isolated in vitro to obtain growth plate chondrocytes for culture. The chondrocytes were observed and identified by inverted phase contrast microscope and typeâ ¡ collagen immunofluorescence test, and then 20 ng/ml IL-1ß was used to induce apoptosis of growth plate chondrocytes as model group, and added with 1, 10, 20, 40 µM linolenin as the experimental group, and 5 µM letrozole as the positive control group. The cells were cultured for 24 and 48 hours respectively. The drug promoted cell proliferation was observed by MTT method, and the drug inhibited cell apoptosis was detected by flow cytometry. RESULTS: Contents 1, 10, 20, 40 µM could promote cell proliferation in varying degrees, and the principle was that the drug inhibits IL-1ß induced chondrocyte apoptosis in the growth plate, and the optimal concentration of drugs to inhibit apoptosis was 20 µM. CONCLUSION: The appropriate concentration of linseed lignans can significantly inhibit the apoptosis of chondrocytes in the growth plate of rats, and the optimal drug concentration is 20 µM. It provides possibility for delayed bone closure and longer growth time to promote bone growth during development.
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Linho , Lignanas , Masculino , Ratos , Animais , Lâmina de Crescimento , Condrócitos , Ratos Sprague-Dawley , Apoptose , Lignanas/farmacologiaRESUMO
Introduction: It has been reported that GRB7 is closely related to a variety of human solid tumors, but its role in gastric cancer has not been reported yet. The purpose of this study was to investigate the expression level and intracellular effects of GRB7 in human gastric cancer. Methods: Real-time fluorescent quantitative PCR and Western blot were used to detect the expression of GRB7 in gastric cancer cell lines. The immunohistochemical staining and SPSS analysis verified the GRB7 protein expression. Stable gastric cancer cell lines, MTT experiments, clone formation experiments, cell cycle flow cytometry experiments, sphere formation experiments and lateral subpopulation cell sorting experiments were conducted to investigate the role of GRB7 in gastric cancer cells. Results: We found that the expression of GRB7 in gastric cancer cell lines was higher than that of the corresponding normal gastric epithelial cells, and correspondingly higher in gastric cancer tissues than its paired adjacent tissues. GRB7 protein was expressed more highly in cancer tissues than in adjacent tissues. GRB7 protein expression levels were positively correlated with the clinical stage of gastric cancer patients, and negatively correlated with the survival prognosis of patients. GSEA analysis of GRB7 mRNA levels in gastric cancer tissues and normal gastric epithelial tissues from public databases showed that GRB7 may affect cell proliferation and related processes of intracellular stem cells. GRB7 can promote the proliferation of gastric cancer cells and is positively related to the self-renewal ability of gastric cancer stem cells. Discussion: This study shows that GRB7 molecules highly expressed in gastric cancer tissues can promote the proliferation of gastric cancer cells and increase the proportion of gastric cancer stem cells, so it is expected to become a diagnostic molecule or potential therapeutic target for gastric cancer.
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Over the last several decades, no emerging virus has had a profound impact on the world as the SARS-CoV-2 that emerged at the end of 2019 has done. To know where severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated from and how it jumped into human population, we immediately started a surveillance investigation in wild mammals in and around Wuhan when we determined the agent. Herein, coronaviruses were screened in the lung, liver, and intestinal tissue samples from fifteen raccoon dogs, seven Siberian weasels, three hog badgers, and three Reeves's muntjacs collected in Wuhan and 334 bats collected around Wuhan. Consequently, eight alphacoronaviruses were identified in raccoon dogs, while nine betacoronaviruses were found in bats. Notably, the newly discovered alphacoronaviruses shared a high whole-genome sequence similarity (97.9 per cent) with the canine coronavirus (CCoV) strain 2020/7 sampled from domestic dog in the UK. Some betacoronaviruses identified here were closely related to previously known bat SARS-CoV-related viruses sampled from Hubei province and its neighbors, while the remaining betacoronaviruses exhibited a close evolutionary relationship with SARS-CoV-related bat viruses in the RdRp gene tree and clustered together with SARS-CoV-2-related bat coronaviruses in the M, N and S gene trees, but with relatively low similarity. Additionally, these newly discovered betacoronaviruses seem unlikely to bind angiotensin-converting enzyme 2 because of the deletions in the two key regions of their receptor-binding motifs. Finally, we did not find SARS-CoV-2 or its progenitor virus in these animal samples. Due to the high circulation of CCoVs in raccoon dogs in Wuhan, more scientific efforts are warranted to better understand their diversity and evolution in China and the possibility of a potential human agent.
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PURPOSE: Our previous studies have shown that kinesin family member 11 (KIF11) is markedly overexpressed in human breast cancer cells or tissues and positively correlated with distant metastasis and prognosis in patients with breast cancer, suggesting an important role in the regulation of cancer stem cells. Herein, we examined the role of KIF11 in breast cancer stem cells. METHODS: In the current study, we validated our previous findings through analysis of data collected in The Cancer Genome Atlas. Endogenous KIF11 was stably silenced in MCF-7 and SKBR-3 cells. Flow cytometry was used to measure the proportion of side-population (SP) cells. Mammosphere culture and tumor implantation experiments in immunodeficient mice were used to assess the self-renewal ability of breast cancer cells. Real-time polymerase chain reaction, western blot, immunofluorescence staining, luciferase reporter assays and Wnt agonist treatment were conducted to investigate the signaling pathways regulated by KIF11. RESULTS: We found that the expression level of KIF11 was positively correlated with stem cell-enrichment genes. The proportion of SP cells was significantly reduced in KIF11-silenced cells. Silencing endogenous KIF11 not only reduced the size and number of mammospheres in vitro, but also reduced the ability of breast cancer cells to form tumors in mice. Simultaneously, we found that KIF11 was involved in regulating the activation of the Wnt/ß-catenin signaling pathway. CONCLUSION: Endogenous KIF11 enhances the self-renewal of breast cancer cells by activating the Wnt/ß-catenin signaling pathway, thereby enhancing the characteristics of breast cancer stem cells.
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BACKGROUND: Acute kidney injury (AKI) is a serious and fatal complication of acute myocardial infarction (AMI). It has high short- and long-term mortality rates and a poor prognosis but is potentially preventable. However, the current incidence, risk factors, and outcomes of AKI in the Chinese population are not well understood and would serve the first step to identify high-risk patients who could receive preventative care. METHODS: The medical data of 1124 hospitalized patients diagnosed with AMI from October 2013 to September 2015 were reviewed. AKI was defined according to the 2012 Kidney Disease Improving Global Outcomes criteria. All the patients were divided into either the AKI group or the non-AKI group. A univariate comparison analysis was performed to identify possible risk factors associated with AKI. A multiple logistic regression analysis was used to identify the independent risk factors for AKI in patients with AMI. RESULTS: Overall, the incidence of AKI was 26.0%. The mortality rate of the AKI group was 20.5%, and the mortality rate of the non-AKI group was 0.6% (Pâ<â0.001). Logistic regression analysis showed that the independent risk factors for AKI in patients with AMI included: age (>60 years old) (odds ratio [OR] 1.04, 95% confidence interval [CI] 1.02-1.05, Pâ=â0.000), hypertension (OR 2.51, 95% CI 1.62-3.87, Pâ=â0.000), chronic kidney disease (OR 3.52, 95% CI 2.01-6.16, Pâ=â0.000), Killip class ≥3 (OR 5.22, 95% CI 3.07-8.87, Pâ=â0.000), extensive anterior myocardial infarction (OR 3.02, 95% CI 1.85-4.93, Pâ=â0.000), use of furosemide (OR 1.02, 95% CI 1.02-1.03, Pâ=â0.000), non-use of angiotensin-converting enzyme inhibitors/angiotensin receptor blocker (OR 1.58, 95% CI 1.04-2.40, Pâ=â0.032). These factors provided an accurate tool to identify patients at high risk of developing AKI. CONCLUSIONS: Approximately 26.0% of patients undergoing AMI developed AKI, and the development of AKI was strongly correlated with in-hospital mortality. The risk factors for AKI in patients with AMI were determined to help identify high-risk patients and make appropriate clinical decisions.
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Injúria Renal Aguda/etiologia , Infarto do Miocárdio/complicações , Injúria Renal Aguda/patologia , Idoso , Feminino , Frequência Cardíaca/fisiologia , Humanos , Incidência , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/patologia , Fatores de RiscoRESUMO
The present study aimed to clarify the association between kinesin family member 11 (KIF11) and human breast cancer, and the effect of KIF11 on breast cancer cell progression. Western blot analysis, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis, retroviral infection, immunohistochemistry staining, MTT assay, anchorage-independent growth ability assay and tumorigenicity assay were all used in the present study. Western blot and RT-qPCR analysis revealed that the expression of KIF11 was markedly increased in malignant cells compared with that in non-tumorous cells at the mRNA and protein level. Immunohistochemical analysis revealed that KIF11 expression was upregulated in 256/268 (95.8%) paraffin-embedded archival breast cancer biopsies. Statistical analysis demonstrated a significant association between the upregulation of KIF11 expression and the progression of breast cancer. Multivariate analysis revealed that KIF11 upregulation represents an independent prognostic indicator for the survival of patients with breast cancer. Tumorigenicity experiments were further used to evaluate the effect of KIF11 in non-obese diabetic/severe combined immunodeficient mice. Silencing endogenous KIF11 by short hairpin RNAs inhibited the proliferation of breast cancer cells in vitro and in vivo. The present results suggest that KIF11 may serve an important function in the proliferation of breast cancer and may represent a novel and useful prognostic marker for breast cancer.
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The aim of the present study was to investigate the effect of bavachin treatment on A375 cells and the regulation of melanin synthesis. The cultured A375 cells in vitro were treated with bavachin; and the effect of bavachin on cell activity, tyrosinase (TYR) activity and melanin synthesis were respectively tested by the MTT assay, L-dopa oxidation assay and the NaOH lysis assay. The expression levels of TYR and c-Jun N-terminal kinases (JNK) proteins were tested by western blot analysis. The expression levels of TYR, tyrosinase-related protein-1 (TRP-1), TRP-2, extracellular signal-regulated kinase 1 (ERK1), ERK2 and JNK2 mRNA were tested by the reverse transcription-polymerase chain reaction assay. Simultaneously, the effect of estrogen receptor inhibitor (ICI182780) and ERK pathway inhibitor (U0126) was also tested on A375 cells following bavachin. The safe dose of bavachin significantly inhibited melanin synthesis and TYR activity. Bavachin (10 µmol/l) inhibited the expression of TYR and JNK proteins, and the expression of TYR, TRP-1, TRP-2, ERK1, ERK2 and JNK2 mRNA in A375 cells. ICI182780 and U0126 could significantly reverse the bavachin treatment on the protein expression levels and the mRNA expression of TYR, TRP-1, TRP-2, ERK1, ERK2 and JNK2. In conclusion, bavachin inhibited the synthesis of melanin on A375 cells by inhibiting the protein and mRNA expression of TYR, TRP-1, TRP-2, ERK1, ERK2 and JNK2.
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OBJECTIVE: To explore the effects of exogenous transforming growth factor-beta 1 (TGFbeta1) on peripheral nerve regeneration after the peripheral nerve injury and if TGFbeta1 regulates the expression of basic fibroblast growth factor (bFGF) in the anterior horn motoneurons of spinal cord during regeneration. METHODS: Forty-eight rats were crushed on the right sciatic nerve and then randomly divided into 2 groups: TGFbeta1 group and NS group. In TGFbeta1 group, TGFbeta1 50 microL (0.1 microg/mL) was injected into the proximal nerve near to the crushed nerve and after the operation the injured leg was injected with equal TGFbeta1 whereas the NS was replaced in the NS group. The rats of each group survived for 3, 7, 14 and 21 days after the lesion. The bFGF expression in the anterior horn motoneurons of spinal cord was detected by immunohistochemistry (IHC). Semi-thin section and Fast Blue retrograde tracing were also performed with the rats surviving for 21 days to observe the regeneration of distal end in the injured right sciatic nerve. RESULTS: The number of bFGF immunoreactive positive motoneurons in TGFbeta1 group was obviously higher than that of the NS group (P < 0.05). In the distal sciatic nerve of the rats treated with TGFbeta1, the number and diameter of regenerating myelinated axons and the thickness of myelinated sheath were more than those of the NS group (P < 0.05). The number of motoneurons in spinal cord and neurons in dorsol root ganglia (DRG) labelled with Fast Blue in the NS group was obviously lower than in the TGFbeta1 group (P < 0.01). CONCLUSION: Exogenous TGFbeta1 plays an important role in promoting the peripheral nerve regeneration; TGFbeta1 up-regulates the bFGF expression in the anterior horn motoneurons of spinal cord during the peripheral nerve regeneration.
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Regeneração Nervosa/efeitos dos fármacos , Nervo Isquiático/fisiologia , Medula Espinal/metabolismo , Fator de Crescimento Transformador beta/farmacologia , Animais , Feminino , Fator 2 de Crescimento de Fibroblastos/biossíntese , Fator 2 de Crescimento de Fibroblastos/genética , Masculino , Neurônios Motores/metabolismo , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Nervo Isquiático/lesões , Nervo Isquiático/metabolismo , Fator de Crescimento Transformador beta1RESUMO
Biotransformation plays an important role in the bioaccumulation and toxicity of a chemical in biota. Dichlorodiphenyltrichloroethane (DDT) commonly co-occurs with its metabolites (dichlorodiphenyldichloroethane [DDD] and dichlorodiphenyldichloroethylene [DDE]), in the environment; thus it is a challenge to accurately quantify the biotransformation rates of DDT and distinguish the sources of the accumulated metabolites in an organism. The present study describes a method developed to quantitatively analyze the biotransformation of p,p'-DDT in the benthic polychaete, Nereis succinea. The lugworms were exposed to sediments spiked with DDT at various concentrations for 28 d. Degradation of DDT to DDD and DDE occurred in sediments during the aging period, and approximately two-thirds of the DDT remained in the sediment. To calculate the biotransformation rates, residues of individual compounds measured in the bioaccumulation testing (after biotransformation) were compared with residues predicted by analyzing the partitioning of the parent and metabolite compounds between gut fluid and tissue lipid (before biotransformation). The results suggest that sediment ingestion rates decreased when DDT concentrations in sediment increased. Extensive biotransformation of DDT occurred in N. succinea, with 86% of DDT being metabolized to DDD and <2% being transformed to DDE. Of the DDD that accumulated in the lugworms, approximately 70% was the result of DDT biotransformation, and the remaining 30% was from direct uptake of sediment-associated DDD. In addition, the biotransformation was not dependent on bulk sediment concentrations, but rather on bioaccessible concentrations of the chemicals in sediment, which were quantified by gut fluid extraction. The newly established method improved the accuracy of prediction of the bioaccumulation and toxicity of DDTs.
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Líquidos Corporais/metabolismo , DDT/metabolismo , Sistema Digestório/metabolismo , Ecossistema , Lipídeos/química , Poliquetos/metabolismo , Animais , Biotransformação , Diclorodifenil Dicloroetileno/metabolismo , Sedimentos Geológicos/química , Peso MolecularAssuntos
Regeneração Nervosa/fisiologia , Traumatismos dos Nervos Periféricos , Células de Schwann/fisiologia , Fator de Crescimento Transformador beta/fisiologia , Animais , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Humanos , Nervos Periféricos/fisiopatologia , Fator de Crescimento Transformador beta1RESUMO
Polyethyleneimine (PEI) has been broadly studied as a leading nonviral gene delivery carrier because of its relatively high transfection efficiency in a wide range of cell types. Here, we report gene transfer in zebrafish cells (ZF4) using PEI as a gene carrier and lipofectamine as a control. Formations of PEI-DNA complexes were characterized by a series of measurements. The particle size of PEI-DNA complexes decreased from 274 to 132 nm, the surface charge gradually increased from -26 to 29 mV, and the cytotoxicity for zebrafish cells was observed with increasing proportion of PEI. Gel retardation assay showed that DNA was completely bound by PEI with a negative-to-positive charge ratio of 4. It was observed by transmission electron microscopy that the morphology of PEI-DNA complexes was spherical with smooth surfaces. Flow cytometry revealed that the optimum transfection efficiency (27%) mediated by PEI was obtained at an negative-to-positive charge ratio of 8, which was higher than that with lipofectamine. Luciferase activity assay confirmed the increase in reporter gene expression probably due to a more efficient formation of complex between DNA and PEI than DNA and lipofectamine. In conclusion, our study demonstrates that PEI may be applied as an effective gene carrier to mediate gene transfer into zebrafish cells.