RESUMO
BACKGROUND: Patients with cognitive dysfunction may present with significantly prolonged the P2 wave latency of flash visual evoked potential. However, no studies have been reported on whether the P2 wave latency of flash visual evoked potential is prolonged in patients with subcortical arteriosclerotic encephalopathy (SAE). OBJECTIVE: To examine the relationship between flash visual evoked potential P2 wave latency (FVEP-P2 wave latency) and cognitive impairment in patients with SAE. METHODS: Overall, we recruited 38 SAE patients as the observation cohort (OC) and 34 healthy volunteers as the control cohort (CC). We measured the FVEP-P2 wave latency for both groups. The SAE patients' cognitive abilities were evaluated via mini-mental state examination (MMSE) and the association between the latency of FVEP-P2 and MMSE score was explored by Pearsons´s correlation test. RESULTS: There is no significant difference between OC (21 males and 17 females; 68.6 ± 6.7 years of age and 9.6 ± 2.8 years of education) and CC (19 males and 15 females; 65.3 ± 5.9 years of age and 10.1 ± 2.6 years of education) in gender and age composition and education level. The FVEP-P2 wave latency of the CC group was (108.80 ± 16.70) ms and the OC FVEP-P2 wave latency was (152.31 ± 20.70) ms. The OC FVEP-P2 wave latency was significantly longer than the CC (P < 0.05). In terms of MMSE scores, the MMSE scores of CC was (28.41 ± 2.34), and that of OC was (9.08 ± 4.39). Compared to the CC, the OC MMSE score was significantly lower (P < 0.05). In addition, the FVEP-P2 wave latency was inversely related to the MMSE (r = -0.4465, P < 0.05) in SAE patients. CONCLUSION: The FVEP-P2 wave latency wave latency was significantly prolonged in SAE patients and strongly associated with the degree of cognitive dysfunction.
Assuntos
Disfunção Cognitiva , Demência Vascular , Masculino , Feminino , Humanos , Potenciais Evocados Visuais , Disfunção Cognitiva/diagnóstico , Cognição , EscolaridadeRESUMO
A Gram-stain-positive, strictly aerobic, non-motile, non-spore-forming and rod-shaped bacterium, designated as strain G-1T, was isolated from farmland soil sampled in in Fuyang, Anhui Province, PR China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain G-1T was closely related to Cumulibacter manganitolerans 2-36T (97.7â% similarity). Strain G-1T contained iso-C16â:â0, C17â:â1ω6c, iso-C15â:â0 and iso-C14â:â0 as the predominant fatty acids. The polar lipids of strain G-1T were diphosphatidylglycerol, phosphatidylethanolamine, an unidentified phospholipid, an unidentified lipid and two unidentified glycolipids. The predominant respiratory quinone of strain G-1T was MK-9(H4). The cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid. The G+C content of the genomic DNA based on genome calculations was 64.2 mol%. Average nucleotide identity and the digital DNA-DNA hybridization values for the draft genomes between strain G-1T and strain 2-36T were 75.7 and 20.2 %, respectively. On the basis of phenotypic and phylogenetic data, strain G-1T is considered to represent a novel species of the genus Cumulibacter, for which the name Cumulibacter soli sp. nov. is proposed. The type strain is G-1T (=CCTCC AB2019021T=KCTC 49258T).
Assuntos
Actinobacteria/classificação , Fazendas , Filogenia , Microbiologia do Solo , Actinobacteria/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Glicolipídeos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMO
A Gram-stain-positive, aerobic, non-motile and coccoid-shaped bacterium, designated XNB-1T, was isolated from farmland soil in Taian, Shandong province, China. Strain XNB-1T contained iso-C15â:â0 and iso-C16â:â0 as the predominant fatty acids. The diagnostic diamino acid of the peptidoglycan was ornithine, and the interpeptide bridge was l-OrnâGly(1, 2)âd-Glu. The polar lipid profile of strain XNB-1T consisted of diphosphatidylglycerol, phosphatidylglycerol, an unidentified phosphoglycolipid and three unidentified phospholipids. The predominant menaquinone of strain XNB-1T was MK-8(H4) and the DNA G+C content was 70.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain XNB-1T belonged to the genus Ornithinicoccus, and shared the highest similarity with Ornithinicoccus hortensis HKI 0125T (96.0â%), followed by Ornithinicoccus halotolerans EGI 80423T (95.5â%). Genome-based analysis of average nucleotide identity of strain XNB-1T with O. hortensis HKI 0125T and O. halotolerans EGI 80423T yielded values of 73.1 and 73.3â%, respectively, while the digital DNA-DNA hybridization values were 19.5 and 19.9â%, respectively. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain XNB-1T is considered to represent a novel species of the genus Ornithinicoccus, for which the name Ornithinicoccus soli sp. nov. is proposed. The type strain is XNB-1T (=CCTCC AB 2019099T=KCTC 49259T).
Assuntos
Actinobacteria/classificação , Fazendas , Filogenia , Microbiologia do Solo , Actinobacteria/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMO
BACKGROUND: Metabolic disorders such as insulin resistance, obesity, and hyperglycemia are prominent risk factors for the development of non-alcoholic fatty liver disease (NAFLD)/steatohepatitis (NASH). Dietary rodent models employ high fat, high cholesterol, high fructose, methionine/choline deficient diets or combinations of these to induce NAFLD/NASH. The FATZO mice spontaneously develop the above metabolic disorders and type 2 diabetes (T2D) when fed with a normal chow diet. The aim of the present study was to determine if FATZO mice fed a high fat and fructose diet would exacerbate the progression of NAFLD/NASH. METHODS: Male FATZO mice at the age of 8 weeks were fed with high fat Western diet (D12079B) supplemented with 5% fructose in the drinking water (WDF) for the duration of 20 weeks. The body weight, whole body fat content, serum lipid profiles and liver function markers were examined monthly along with the assessment of liver histology for the development of NASH. In addition, the effects of obeticholic acid (OCA, 30 mg/kg, QD) on improvement of NASH progression in the model were evaluated. RESULTS: Compared to normal control diet (CD), FATZO mice fed with WDF were heavier with higher body fat measured by qNMR, hypercholesterolemia and had progressive elevations in AST (~ 6 fold), ALT (~ 6 fold), liver over body weight (~ 2 fold) and liver triglyceride (TG) content (1.4-2.9 fold). Histological examination displayed evidence of NAFLD/NASH, including hepatic steatosis, lobular inflammation, ballooning and fibrosis in FATZO mice fed WDF. Treatment with OCA for 15 weeks in FATZO mice on WDF significantly alleviated hypercholesterolemia and elevation of AST/ALT, reduced liver weight and liver TG contents, attenuated hepatic ballooning, but did not affect body weight and blood TG levels. CONCLUSION: WDF fed FATZO mice represent a new model for the study of progressive NAFLD/NASH with concurrent metabolic dysregulation.
Assuntos
Diabetes Mellitus Tipo 2/complicações , Dieta Hiperlipídica/efeitos adversos , Dieta Ocidental/efeitos adversos , Modelos Animais de Doenças , Frutose/efeitos adversos , Hepatopatia Gordurosa não Alcoólica/etiologia , Obesidade/complicações , Edulcorantes/efeitos adversos , Animais , Progressão da Doença , Fígado/patologia , Fígado/fisiopatologia , Masculino , Camundongos , Hepatopatia Gordurosa não Alcoólica/patologia , Hepatopatia Gordurosa não Alcoólica/fisiopatologiaRESUMO
A Gram-stain-negative, aerobic, non-motile, non-spore-forming and rod-shaped bacterium, designated YHM-9T, was isolated from soil in Yangquan, Shanxi Province, PR China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YHM-9T belonged to the genus Pedobacter and shared the highest similarity (97.4â%) to the type strain Pedobacter lignilitoris W-WS13T. Strain YHM-9T exhibited low DNA-DNA relatedness with P. lignilitoris W-WS13T (21.7±1.3â%). The DNA G+C content was 38.9 mol%. The major fatty acids were iso-C15â:â0, summed feature 3 (C16â:â1ω7c and/or C16â:â1ω6c) and iso-C17â:â0 3-OH. The respiratory quinone was MK-7, the major polyamine was sym-homospermidine and the major polar lipids were phosphatidylethanolamine. Based on the morphological, physiological, biochemical and chemotaxonomic characteristics, strain YHM-9T was recognized as a representative of a novel species within the genus Pedobacter, for which the name Pedobacteragrisoli sp. nov. is proposed. The type strain is YHM-9T (=JCM 32093T=CCTCC AB 2017125T).
Assuntos
Fazendas , Pedobacter/classificação , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Pedobacter/genética , Pedobacter/isolamento & purificação , Fosfatidiletanolaminas/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Espermidina/análogos & derivados , Espermidina/química , Vitamina K 2/químicaRESUMO
OBJECTIVE: To determine whether orbitofrontal cortex (OFC) function improves with blepharospasm (BSP) symptom remission using a verbal fluency task and near-infrared spectroscopy (NIRS). METHODS: Nineteen BSP patients and 9 healthy controls (HCs) matched by gender and education were examined using NIRS. The BSP patients were divided into 2 groups based on the onset or remission of BSP symptoms. A covariance analysis was conducted to analyze the differences among the 3 groups to avoid the influence of different ages. The least significant difference was used to process the post hoc test. RESULTS: The hemoglobin concentration and cerebral blood flow of the bilateral orbitofrontal area (channels 27, 31, 34, 37, and 39) were not significantly different between the BSP remission and HC groups (p > 0.05); however, both groups were significantly increased compared with the BSP onset group (BSP remission group vs. BSP onset group: p = 0.003, p = 0.018, p = 0.013, p = 0.001, and p = 0.011, respectively; BSP remission group vs. BSP onset group: p = 0.037, p = 0.044, p = 0.023, p = 0.016, and p = 0.025, respectively). CONCLUSION: This is the first investigation to control for symptom stages in BSP patients examined via NIRS. Cognitive ability and OFC function improve with BSP symptom remission. Thus, the OFC may be inter-connected with motor and cognitive symptoms in BSP.
Assuntos
Blefarospasmo/fisiopatologia , Córtex Pré-Frontal/fisiopatologia , Comportamento Verbal/fisiologia , Adulto , Blefarospasmo/complicações , Circulação Cerebrovascular , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Espectroscopia de Luz Próxima ao InfravermelhoRESUMO
BACKGROUND: Neurotrophic factors have been implicated in hyperalgesia and peripheral levels of these molecules are altered in migraine pathophysiology. Artemin, a vasculature-derived neurotrophic factor, contributes to pain modulation and trigeminal primary afferent sensitization through binding its selective receptor GFRα3. The distribution of artemin and GFRα3 in the dura mater raises an anatomy supports that they may be involved in migraine. In this study we evaluated the expression of artemin and GFRα3 in an animal migraine model that may be relevant for migraine. METHODS: In this study, using a rat migraine model by administration of nitroglycerin (NTG), we investigated the expression of artemin in the dura mater and GFRα3 in the trigeminal ganglia (TG) by means of quantitative reverse transcription-polymerase chain reaction, western blot and immunofluorescence labeling. RESULTS: Artemin immunoreactivity was found in the smooth muscle cells of dural vasculature and GFRα3 was present in cytoplasm of TG neurons. The mRNA levels of artemin and GFRα3 were significantly elevated after NTG treatment at 2 and 4 h respectively (P < 0.05). The expression of artemin protein was increased at 4 h and continually up to 8 h in the dura mater following NTG administration (P < 0.05). The expression of GFRα3 protein was elevated at 4 h and continually up to 10 h in the TG following NTG administration (P < 0.05). CONCLUSION: The findings suggest that artemin and GFRα3 play an important role in the pathogenesis of migraine and may represent potential therapeutic targets for the treatment of migraine.
Assuntos
Dura-Máter/metabolismo , Receptores de Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Transtornos de Enxaqueca/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Gânglio Trigeminal/metabolismo , Animais , Modelos Animais de Doenças , Masculino , Transtornos de Enxaqueca/induzido quimicamente , Ratos , Ratos WistarRESUMO
Fully differentiated pancreatic ß cells are essential for normal glucose homeostasis in mammals. Dedifferentiation of these cells has been suggested to occur in type 2 diabetes, impairing insulin production. Since chronic fuel excess ("glucotoxicity") is implicated in this process, we sought here to identify the potential roles in ß-cell identity of the tumor suppressor liver kinase B1 (LKB1/STK11) and the downstream fuel-sensitive kinase, AMP-activated protein kinase (AMPK). Highly ß-cell-restricted deletion of each kinase in mice, using an Ins1-controlled Cre, was therefore followed by physiological, morphometric, and massive parallel sequencing analysis. Loss of LKB1 strikingly (2.0-12-fold, E<0.01) increased the expression of subsets of hepatic (Alb, Iyd, Elovl2) and neuronal (Nptx2, Dlgap2, Cartpt, Pdyn) genes, enhancing glutamate signaling. These changes were partially recapitulated by the loss of AMPK, which also up-regulated ß-cell "disallowed" genes (Slc16a1, Ldha, Mgst1, Pdgfra) 1.8- to 3.4-fold (E < 0.01). Correspondingly, targeted promoters were enriched for neuronal (Zfp206; P = 1.3 × 10(-33)) and hypoxia-regulated (HIF1; P = 2.5 × 10(-16)) transcription factors. In summary, LKB1 and AMPK, through only partly overlapping mechanisms, maintain ß-cell identity by suppressing alternate pathways leading to neuronal, hepatic, and other characteristics. Selective targeting of these enzymes may provide a new approach to maintaining ß-cell function in some forms of diabetes.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Células Secretoras de Insulina/enzimologia , Insulina/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Diabetes Mellitus Tipo 2/metabolismo , Camundongos Endogâmicos C57BL , Transdução de Sinais/fisiologiaRESUMO
Simple sequence repeats (SSRs)are a class of repetitive DNA sequences, which are commonly used for genome analysis. Comparison of the homologous SSRs among different genomes is helpful to understand the evolutionary process in relative species. In this study, SSR scanning was performed to investigate their distribution and length variation among the genomes of G. raimondii (D5), G. arboretum (A2) and G. hirsutum (AD1). The results demonstrated that the distribution of SSRs in A genome was very similar with that in D genome, while the length variation of homologous SSRs between A and AD genome was more conserved than that between D and AD genome. Compared with SSRs in AD genome, the number of SSRs with longer motif length in A genome was about five times of those with shorter motif length, while it was about three times in D genome. This implied that the length variation rates of homologous SSRs between diploid cotton and tetraploid cotton were different during the parallel evolution due to the subgenome fusion, and the motif length of most SSRs in tetraoploid genome tended to become shorter than homologous SSRs in diploid genome during the process of evolution. This study comprehensively compared the SSRs in three cotton genomes and revealed the significant difference among them, providing a foundation for further evolutionary study of Gossypium genome.
Assuntos
Diploide , Genoma de Planta , Gossypium/genética , Repetições de Microssatélites , TetraploidiaRESUMO
Nano-sized microplastic pollution is distributed worldwide. Nano-sized microplastics can enter the blood through the digestive tract, and then transported to various tissues and organs of the body, resulting in a series of toxicological effects. In addition, nano-sized microplastics can penetrate the skin barrier. However, the toxicological effects of nano-sized microplastics on the skin are still not completely understood. Two skin cell lines were used as in vitro models to investigate the toxicological effects of nano-sized microplastics on skin cells and their potential molecular mechanisms. First, cellular behavioral research results showed that nano-sized microplastics can be internalized into skin cells in a time- and dose-dependent manner. Further experiments using western blotting, indirect immunofluorescence, and ELISA assays demonstrated that nano-sized microplastics cause an increase in skin cell inflammation levels. Additionally, our research showed that nano-sized microplastics caused skin cell senescence damage by evaluating aging-marker molecules such as p16 and p21. Subsequently, we studied the potential molecular mechanism by which nano-sized microplastics cause pathological skin injury and found that they induce mitochondrial oxidative stress, depolarize the mitochondrial membrane potential, and recruit GSDMD to the mitochondria. Subsequently, mtDNA enters the cytoplasm via GSDMD pores, which then activates the AIM2 Inflammasome. Ultimately, it causes a series of biochemical reactions such as inflammation and aging in cells. In an in vivo model, we tested the effect of nano-sized microplastics on skin regeneration and found that they acted as an inhibitor to skin regeneration and aggravated the inflammatory reaction of the skin. Overall, our results provide new evidence of the skin toxicity of nano-sized microplastics. This study provides a theoretical foundation for further research on the potential toxicological effects of nano-sized microplastics on the skin.
Assuntos
Senescência Celular , Microplásticos , Mitocôndrias , Pele , Microplásticos/toxicidade , Senescência Celular/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Pele/efeitos dos fármacos , Pele/metabolismo , Humanos , Animais , Nanopartículas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Linhagem Celular , Camundongos , Potencial da Membrana Mitocondrial/efeitos dos fármacosRESUMO
OBJECTIVE: In this study, we compared the analgesic effects of intercostal nerve block (ICNB), ultrasound-guided paravertebral nerve block (PVB), and epidural block (EB) following single-port thoracoscopic lung surgery. METHOD: A total of 120 patients who underwent single-hole thoracoscopic lung surgery were randomly and equally divided into three groups: ICNB group, the PVB group, and the EB group. ICNB was performed under direct thoracoscopic visualization before the conclusion of the surgery in the ICNB group, while PVB and EB were performed after general anesthesia in the PVB and EB groups, respectively. Patient-controlled intravenous analgesia (PCIA) was used following the surgery in all the groups. The following indicators were recorded: Intraoperative sufentanil dosage, anesthesia awakening time, postoperative intubation time, nerve block operation time, postoperative visual analog scale (VAS) pain scores during resting and coughing at regular intervals of 0, 2, 4, 8, 24, and 48 h, the time until first PCIA, number of effective compressions within 24 h postoperatively, number of rescue analgesia interventions, and the side effects. RESULTS: In comparison to the ICNB group, the PVB and EB groups had a lower intraoperative sufentanil dosage, significantly shorter anesthesia awakening time, and postoperative intubation time, but longer nerve block operation time, lower VAS scores when resting and coughing within 24 h postoperatively (all p-values less than 0.05). Conversely, there were no statistically significant differences in VAS scores during resting and coughing after 24 h (all p-values greater than 0.05). Time to first PCIA, number of effective compressions and number of rescue analgesia at the 24-hour mark postoperatively were significantly better in the PVB and EB groups than that in the ICNB group (P < 0.05). However, there was a higher incidence of side effects observed in the EB group (P < 0.05). CONCLUSION: The analgesic effect of PVB and EB following single-port thoracoscopic lung surgery is better than that of ICNB. PVB causes fewer side effects and complications and is safer and more effective.
Assuntos
Nervos Intercostais , Bloqueio Nervoso , Dor Pós-Operatória , Ultrassonografia de Intervenção , Humanos , Bloqueio Nervoso/métodos , Feminino , Masculino , Pessoa de Meia-Idade , Ultrassonografia de Intervenção/métodos , Dor Pós-Operatória/prevenção & controle , Cirurgia Torácica Vídeoassistida/métodos , Idoso , Medição da Dor , Adulto , Toracoscopia/métodos , Pulmão/cirurgiaRESUMO
Amylin, a member of the calcitonin family, acts via amylin receptors in the hindbrain and hypothalamus to suppress appetite. Native ligands of these receptors are peptides with short half-lives. Conjugating fatty acids to these peptides can increase their half-lives. The long-acting human amylin analog, NN1213, was generated from structure-activity efforts optimizing solubility, stability, receptor affinity, and selectivity, as well as in vivo potency and clearance. In both rats and dogs, a single dose of NN1213 reduced appetite in a dose-dependent manner and with a long duration of action. Consistent with the effect on appetite, studies in obese rats demonstrated that daily NN1213 dosing resulted in a dose-dependent reduction in body weight over a 21-day period. Magnetic resonance imaging indicated that this was primarily driven by loss of fat mass. Based on these data, NN1213 could be considered an attractive option for weight management in the clinical setting.
Assuntos
Polipeptídeo Amiloide das Ilhotas Pancreáticas , Animais , Polipeptídeo Amiloide das Ilhotas Pancreáticas/química , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Humanos , Cães , Ratos , Relação Estrutura-Atividade , Masculino , Obesidade/tratamento farmacológico , Peso Corporal/efeitos dos fármacos , Receptores de Polipeptídeo Amiloide de Ilhotas Pancreáticas/metabolismoRESUMO
Cotton genomic studies have boomed since the release of Gossypium raimondii draft genome. In this study, cis-regulatory element (CRE) in 1 kb length sequence upstream 5' UTR of annotated genes were selected and scanned in the Arabidopsis thaliana (At) and Gossypium raimondii (Gr) genomes, based on the database of PLACE (Plant cis-acting Regulatory DNA Elements). According to the definition of this study, 44 (12.3%) and 57 (15.5%) CREs presented "peak-like" distribution in the 1 kb selected sequences of both genomes, respectively. Thirty-four of them were peak-like distributed in both genomes, which could be further categorized into 4 types based on their core sequences. The coincidence of TATABOX peak position and their actual position ((-) -30 bp) indicated that the position of a common CRE was conservative in different genes, which suggested that the peak position of these CREs was their possible actual position of transcription factors. The position of a common CRE was also different between the two genomes due to stronger length variation of 5' UTR in Gr than At. Furthermore, most of the peak-like CREs were located in the region of -110 bp-0 bp, which suggested that concentrated distribution might be conductive to the interaction of transcription factors, and then regulate the gene expression in downstream.
Assuntos
Arabidopsis/genética , Gossypium/genética , Proteínas de Plantas/genética , Regiões Promotoras Genéticas , Regulação da Expressão Gênica de Plantas , TATA BoxRESUMO
To quantitatively evaluate the effects of drought on vegetation productivity in the Qinling-Daba Mountains, we analyzed the temporal and spatial characteristics of gross primary productivity (GPP) and drought, identified the fluctuation of negative GPP extremes under different vegetation types, and quantified the drought vulnerability and drought risk of GPP from 2001 to 2020 with MODIS GPP products and standardized precipitation evapotranspiration index (SPEI). The results showed that the annual GPP from 2001 to 2020 had an increasing trend in 98.0% of areas in the Qinling-Daba Mountains. The GPP of all vegetation types except wetlands increased significantly. SPEI decreased in 23.8% of area in the Qinling-Daba Mountains from 2001 to 2020. The number of negative GPP extremes had no significant trend, but abnormal GPP fluctuations had intensified, especially in the cultivated land. After 2011, the proportion of concurrent negative GPP extreme and drought had decreased for all vegetation types, but the spatial and temporal range of drought in these negative GPP extremes showed an expanding trend. Compared with the pattern during 2001-2010, the proportion of area with positive drought vulnerability and drought risk increased by 104.1% and 6.7% after 2011, indicating that the area with drought-induced GPP decline had expanded. Among all the vegetation types, drought caused the largest decrease of GPP in wetlands. The results revealed that drought led to an aggravation of GPP fluctuations and increased frequency of GPP extremes in the Qinling-Daba Mountains from 2001 to 2020, which resulted in GPP decline with different magnitudes in most vegetation types.
Assuntos
Secas , Ecossistema , China , Mudança ClimáticaRESUMO
In this paper, the Hubbard model on a honeycomb lattice is investigated by using an O(3) nonlinear σ model. A possible candidate for a quantum non-magnetic insulator in a narrow parameter region is found near the metal-insulator transition. After studying the magnetic properties of the quantum non-magnetic insulator, anomalous spin dynamics is shown. In addition, we find that this region could be widened by hole doping.
RESUMO
OBJECTIVE: To define the protective role of pericardial tissue and identify the subcellular population with potential contribution to cardiac protection after injury in a rat model. METHODS: Myocardial infarction (MI) was created by the ligation of left anterior descending artery (LAD) in rats while the pericardial sac was either completely removed (-PC, n = 10) or surgically closed after ligation (+PC, n = 8). The follow-up functional and structure benefits were analyzed by echocardiography and 2,3,5- triphenyl-2H-tetrazolium, chloride(TTC) and bromodeoxyuridine (BrdU) staining. The contributions of cardiac stem cells (sca-1, c-kit and KDR) were evaluated by immunohistochemistry. RESULTS: The integrity of pericardial sac showed significant benefits of cardiac contractile function (ejection fraction and short axis fractional shortening) in comparison to the controls (52 ± 12 vs 37 ± 12 and 36 ± 14 vs 25 ± 13, both P < 0.05). The observed functional amelioration after MI was obvious based on structural repair examined by TTC staining and BrdU incorporation, showing significantly more de novo cardiomyocytes in +PC rats. Interestingly, we have immunohistologically identified a sub-population of KDR+(flk-1+) cells in pericardial tissue which clone genetically distributed and mildly expressed cardiac specific proteins (cTnT). It suggested that the KDR+ cells might act as cardiac progenitors and therefore play an important role in cardiac repair. Meanwhile, rare SCA-1 and c-kit positive cells were detected in pericardial tissue. CONCLUSION: The intact pericardial tissue exerts protective effects after MI. It may be related with a specific cell population of KDR+ cells from pericardial tissue.
Assuntos
Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/fisiopatologia , Pericárdio , Animais , Masculino , Miocárdio/citologia , Miocárdio/metabolismo , Pericárdio/citologia , Ratos , Ratos Wistar , Regeneração , Células-TroncoRESUMO
The tumor suppressor liver kinase B1 (LKB1), also called STK11, is a protein kinase mutated in Peutz-Jeghers syndrome. LKB1 phosphorylates AMP-activated protein kinase (AMPK) and several related protein kinases. Whereas deletion of both catalytic isoforms of AMPK from the pancreatic beta-cell and hypothalamic neurons using the rat insulin promoter (RIP2).Cre transgene (betaAMPKdKO) diminishes insulin secretion in vivo, deletion of LKB1 in the beta-cell with an inducible Pdx-1.CreER transgene enhances insulin secretion in mice. To determine whether the differences between these models reflect genuinely distinct roles for the two kinases in the beta-cell or simply differences in the timing and site(s) of deletion, we have therefore created mice deleted for LKB1 with the RIP2.Cre transgene. In marked contrast to betaAMPKdKO mice, betaLKB1KO mice showed diminished food intake and weight gain, enhanced insulin secretion, unchanged insulin sensitivity, and improved glucose tolerance. In line with the phenotype of Pdx1-CreER mice, total beta-cell mass and the size of individual islets and beta-cells were increased and islet architecture was markedly altered in betaLKB1KO islets. Signaling by mammalian target of rapamycin (mTOR) to eIF4-binding protein-1 and ribosomal S6 kinase was also enhanced. In contrast to Pdx1-CreER-mediated deletion, the expression of Glut2, glucose-induced changes in membrane potential and intracellular Ca(2+) were sharply reduced in betaLKB1KO mouse islets and the stimulation of insulin secretion was modestly inhibited. We conclude that LKB1 and AMPK play distinct roles in the control of insulin secretion and that the timing of LKB1 deletion, and/or its loss from extrapancreatic sites, influences the final impact on beta-cell function.
Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Western Blotting , Peso Corporal/fisiologia , Diabetes Mellitus Tipo 2/enzimologia , Diabetes Mellitus Tipo 2/genética , Ingestão de Alimentos/fisiologia , Teste de Tolerância a Glucose , Insulina/sangue , Secreção de Insulina , Células Secretoras de Insulina/enzimologia , Células Secretoras de Insulina/ultraestrutura , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Microscopia de Fluorescência , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , RNA , Proteína Serina-Treonina Quinase 2 de Interação com Receptor , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Organismos Livres de Patógenos Específicos , TransgenesRESUMO
Carbohydrate responsive element-binding protein (ChREBP) is a transcription factor whose expression and activity are increased in pancreatic ß-cells maintained at elevated glucose concentrations. We show here that ChREBP inactivation in clonal pancreatic MIN6 ß-cells results in an increase in Pdx-1 expression at low glucose and to a small, but significant, increase in Ins2, GcK and MafA gene expression at high glucose concentrations. Conversely, adenovirus-mediated over-expression of ChREBP in mouse pancreatic islets results in decreases in Pdx-1, MafA, Ins1, Ins2 and GcK mRNA levels. These data suggest that strategies to reduce ChREBP activity might protect against ß-cell dysfunction in type 2 diabetes.
Assuntos
Regulação da Expressão Gênica , Glucose/metabolismo , Proteínas de Homeodomínio/genética , Células Secretoras de Insulina/metabolismo , Proteínas Nucleares/metabolismo , Transativadores/genética , Fatores de Transcrição/metabolismo , Animais , Sequência de Bases , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Linhagem Celular Tumoral , Inativação Gênica , Glucose/farmacologia , Células Secretoras de Insulina/efeitos dos fármacos , Camundongos , Dados de Sequência Molecular , Proteínas Nucleares/genética , Fatores de Transcrição/genéticaRESUMO
OBJECTIVE: Retrospective analyze the long-term efficacy and compensatory sweating of thoracoscopic sympathectomy in the treatment of palmar hyperhidrosis by different operative methods in order to search after a better operative method. METHODS: Retrospective study of 643 cases (498 cases available) palmar hyperhidrosis who accepted video-assisted thoracoscopic bilateral sympathectomy during from 1995 to Aug 2008. The patients were divided into four groups by different operative methods. (1) Group A(n = 82): Thoracoscopic T2-4 sympathectomy was performed. (2) Group B (n = 135): Thoracoscopic T2 sympathectomy was performed. (3) Group C (n = 41): Thoracoscopic T2 sympathetic nerve clipped. (4) Group D (n = 240): Thoracoscopic T3-4 level sympathectomy plus bypass fiber (Kuntz fiber) resection on same level was performed. RESULTS: All procedures were successfully performed under thoracoscope without severe morbidity and mortality. The curative rate of palmar hyperhidrosis was 100.00%. The incidence of compensatory sweating were 54.9% (group A), 48.1% (group B), 48.8% (group C) and 28.8% (group D) respectively with significantly decrease in group D contrast to other three groups. The incidence of high-grade compensatory sweating which have important influences on daily life were 9.8% (group A), 10.4% (group B), 9.8% (group C) and 2.9% (group D) respectively with significantly decrease in group D. Other pairings have nonsignificance. The relapse rate were 1.2% (group A), 2.2% (group B), 7.3% (group C) and 0.8% (group D). Only when group D contrasted to group C has significantly decrease in the relapse rate (χ(2) = 8.423, P = 0.004). Other pairings have nonsignificance. CONCLUSION: The procedure of T3-4 sympathectomy plus bypass fiber resection is reasonable operative method to cure hyperhidrosis with the better curative effect and lowest incidence of compensatory hyperhidrosis.
Assuntos
Hiperidrose/cirurgia , Simpatectomia/métodos , Cirurgia Torácica Vídeoassistida , Adolescente , Adulto , Feminino , Mãos , Humanos , Hiperidrose/etiologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/cirurgia , Estudos Retrospectivos , Toracoscopia/métodos , Adulto JovemRESUMO
Ecological stoichiometry provides a new method for understanding the characteristics, driving forces and mechanisms of C, N and P coupled cycles. However, there are few reports on the variation in ecological stoichiometry of plants during their growth. In this study, we fitted the total elemental mass of different module based on the size of Nitraria tangutorum, and derived the ecological stoichiometry models of different module and whole ramet by measuring the biomass and nutrient concentrations of the current-year stems in 2017, 2-year-old stems, more than 2-year-old stems, leaves, roots and layerings of N. tangutorum ramet. Our results showed that the derivation model could well reflect the changes in ecological stoichiometry during plant growth. The old stems and the layering had higher N:P and C:P, while leaves,current-year stems, and roots had lower N:P and C:P. The whole plant nutrient elements cumulative rate was P:N:C during the growth process. These results were consistent with the growth rate hypothesis and allometric theory, and provide evidence for nutrient reabsorption. This model could be used as an effective way to analyze the dynamic characteristics of elements in plant growth.