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1.
Food Chem ; 452: 139580, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38744129

RESUMO

The absence of high-affinity antibodies has hindered the development of satisfactory immunoassays for dichlorvos (DDVP) and trichlorfon (TCP), two highly toxic organophosphorus pesticides. Herein, the de novo synthesis of a novel anti-DDVP hapten was introduced. Subsequently, a specific anti-DDVP monoclonal antibody (Mab) was produced with satisfying affinity to DDVP (IC50: 12.4 ng mL-1). This Mab was highly specific to DDVP, and TCP could readily convert into DDVP under mild alkaline conditions. Leveraging this insight, an indirect competitive ELISA was successfully developed for simultaneous detection of DDVP and TCP. The limit of detection in rice, cabbage and apple for DDVP /TCP was found to be 12.1/14.6 µg kg-1, 7.3/8.8 µg kg-1 and 6.9/8.3 µg kg-1, respectively. This study not only provides an effective strategy for producing a high-quality anti-DDVP Mab but also affords a reliable and cost-effective tool suitable for high-throughput detection of DDVP and TCP in food samples.

2.
Zhongguo Zhong Yao Za Zhi ; 49(2): 403-411, 2024 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-38403316

RESUMO

Based on the concept of quality by design(QbD), this study optimized the processing technology of Ilicis Rotundae Cortex. According to the processing method and ingredient requirements of Ilicis Rotundae Cortex in the Chinese Pharmacopoeia, the content of syringin and pedunculoside, alcohol extract, fragmentation rate, and moisture content were taken as the critical quality attributes(CQAs). The soaking time, moistening time, and drying time were taken as critical process parameters(CPPs) by single factor tests. The weight coefficients of CQAs were determined by the analytic hierarchy process(AHP)-entropy weighting method, and the comprehensive score was calculated. With the comprehensive score as the response value, Box-Behnken design was employed to establish a mathematical model between CPPs and CQAs, and the design space for the processing of Ilicis Rotundae Cortex was built and verified. The results of ANOVA showed that the mathematical model had the P value below 0.05, the lack of fit greater than 0.05, adjusted R~2=0.910 5, and predicted R~2=0.831 0, which indicated that the proposed model had statistical significance and good prediction performance. Considering the factors in production, the best processing conditions of Ilicis Rotundae Cortex were decoction pieces of about 1 cm soaking for 1 h, moistening for 4 h, and drying at 60-70 ℃ in a blast drier for 2 h. The optimized processing technology of Ilicis Rotundae Cortex was stable and feasible, which can provide a reference for the standardized preparation and stable quality of Ilicis Rotundae Cortex.


Assuntos
Medicamentos de Ervas Chinesas , Casca de Planta , Tecnologia , Etanol
3.
Environ Technol ; 45(11): 2132-2143, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36601874

RESUMO

The efficient removal of 2-Methylisoborneol (2-MIB), a typical odour component, in water treatment plants (WTPs), poses a great challenge to conventional water treatment technology due to its chemical stability. In this study, the combination of ultraviolet light-emitting diode (UV-LED) and chlorine (UV-LED/chlorine) was exploited for 2-MIB removal, and the role of ultraviolet (UV) wavelength was investigated systematically. The results showed that UV or chlorination alone did not degrade 2-MIB effectively, and the UV/chlorine process could degrade 2-MIB efficiently, following the pseudo-first-order kinetic model. The 275 nm UV exhibited higher 2-MIB degradation efficiency in this UV-LED/chlorine system than 254 nm UV, 265 nm UV and 285 nm UV due to the highest mole adsorption coefficient and quantum yield of chlorine in 275 nm UV. ·OH and ·Cl produced in the 275 nm UV/chlorine system played major roles in 2-MIB degradation. HCO3- and Natural organic matter (NOM), prevalent in water, consumed ·OH and ·Cl, thus inhibiting the 2-MIB degradation by UV-LED/chlorine. In addition, NOM and 2-MIB could form a photonic competition effect. The degradation of 2-MIB by UV-LED/chlorine was done mainly through dehydration and demethylation, and odorous intermediates, such as camphor, were produced. 2-MIB was degraded through the α bond fracture and six-membered ring opening to form saturated or unsaturated hydrocarbons and aldehydes. Four DBPs, chloroform (CF), trichloroacetaldehyde (TCE), trichloroacetone (TCP) and dichloroacetone (DCP), were mainly generated, and CF was the most significant by-product.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Cloro/química , Desinfecção/métodos , Poluentes Químicos da Água/química , Raios Ultravioleta , Halogenação , Clorofórmio , Cinética , Purificação da Água/métodos , Oxirredução
4.
Heliyon ; 9(8): e18731, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37576216

RESUMO

Verticillium wilt (VW), Fusarium wilt (FW) and Root-knot nematode (RKN) are the main diseases affecting cotton production. However, many reported quantitative trait loci (QTLs) for cotton resistance have not been used for agricultural practices because of inconsistencies in the cotton genetic background. The integration of existing cotton genetic resources can facilitate the discovery of important genomic regions and candidate genes involved in disease resistance. Here, an improved and comprehensive meta-QTL analysis was conducted on 487 disease resistant QTLs from 31 studies in the last two decades. A consensus linkage map with genetic overall length of 3006.59 cM containing 8650 markers was constructed. A total of 28 Meta-QTLs (MQTLs) were discovered, among which nine MQTLs were identified as related to resistance to multiple diseases. Candidate genes were predicted based on public transcriptome data and enriched in pathways related to disease resistance. This study used a method based on the integration of Meta-QTL, known genes and transcriptomics to reveal major genomic regions and putative candidate genes for resistance to multiple diseases, providing a new basis for marker-assisted selection of high disease resistance in cotton breeding.

5.
Clin Exp Ophthalmol ; 51(7): 673-684, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37468126

RESUMO

BACKGROUND: We performed a systematic review and meta-analysis to investigate the links between different sleep characteristics and risk of myopia. METHODS: PubMed, EMBASE, Web of Science, the Cochrane Library, PsycINFO, Wanfang, and CNKI were searched from inception to August 26, 2022, without any language restriction. Cross-sectional, case-control, or cohort studies that explored the association between sleep duration, sleep quality, bedtime, and myopia were included. NIH quality assessment tools were used to assess the methodological quality of included studies. Random-effect or fixed-effect models were used to pool the associations according to whether there is heterogeneity. RESULTS: A total of 31 studies with 205 907 participants were included in the final analysis (25 studies reporting sleep duration; four studies examining sleep quality and six studies evaluating bedtime). Compared to reference sleep duration, sufficient sleep duration (OR = 0.63, 95% CI = 0.51-0.78) was associated with a lower risk of myopia, and short sleep duration (OR = 1.66, 95% CI = 1.14-2.42) was associated with a higher risk of myopia. In addition, poor sleep quality (OR = 1.24, 95% CI = 1.05-1.47) was associated with a higher risk of myopia while late bedtime (OR = 1.30, 95% CI = 0.96-1.75) was not significantly associated with an increased risk of myopia. CONCLUSIONS: Alteration in sleep duration and sleep quality may influence the risk of myopia. Well-designed cohort studies are needed in future investigations to identify a causal relationship between different sleep characteristics and myopia.

6.
Plant Physiol Biochem ; 201: 107853, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37385030

RESUMO

Protein ubiquitination is essential for plant growth and responses to the environment. The SEVEN IN ABSENTIA (SINA) ubiquitin ligases have been extensively studied in plants, but information on their roles in fiber development is limited. Here, we identified GhSINA1 in Upland cotton (Gossypium hirsutum), which has a conserved RING finger domain and SINA domain. Quantitative real-time PCR (qRT-PCR) analysis showed that GhSINA1 was preferentially expressed during fiber initiation and elongation, especially during initiation in the fuzzless-lintless cotton mutant. Subcellular localization experiments indicated that GhSINA1 localized to the nucleus. In vitro ubiquitination analysis revealed that GhSINA1 has E3 ubiquitin ligase activity. Ectopic overexpression of GhSINA1 in Arabidopsis thaliana reduced the number and length of root hairs and trichomes. Yeast two-hybrid (Y2H), firefly luciferase complementation imaging (LCI), and bimolecular fluorescence complementation (BiFC) assays demonstrated that the GhSINA1 proteins could interact with each other to form homodimers and heterodimers. Overall, these results suggest that GhSINA1 may act as a negative regulator in cotton fiber development through homodimerization and heterodimerization.


Assuntos
Arabidopsis , Gossypium , Gossypium/metabolismo , Fibra de Algodão , Ubiquitina/metabolismo , Ligases/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas
7.
World J Diabetes ; 14(3): 179-187, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-37035228

RESUMO

Gestational diabetes mellitus (GDM) is a common pregnancy complication strongly associated with poor maternal-fetal outcomes. Its incidence and prevalence have been increasing in recent years. Women with GDM typically give birth through either vaginal delivery or cesarean section, and the maternal-fetal outcomes are related to several factors such as cervical level, fetal lung maturity, the level of glycemic control still present, and the mode of treatment for the condition. We categorized women with GDM based on the latter two factors. GDM that is managed without medication when it is responsive to nutrition- and exercise-based therapy is considered diet- and exercise-controlled GDM, or class A1 GDM, and GDM managed with medication to achieve adequate glycemic control is considered class A2 GDM. The remaining cases in which neither medical nor nutritional treatment can control glucose levels or patients who do not control their blood sugar are categorized as class A3 GDM. We investigated the optimal time of delivery for women with GDM according to the classification of the condition. This review aimed to address the benefits and harms of giving birth at different weeks of gestation for women with different classes of GDM and attempted to provide an analytical framework and clearer advice on the optimal time for labor.

8.
J Agric Food Chem ; 71(19): 7575-7583, 2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37057807

RESUMO

Tricaine is a common anesthetic used in the long-distance transport of live fish. Recently, its negative impact on human health has aroused extensive concern. Thus, rapid and reliable techniques for tricaine residue analysis are essential to ensuring the quality of aquatic products. Herein, a specific anti-tricaine monoclonal antibody (Mab) was prepared. Then, a sensitive and robust ratiometric fluorescence ELISA (RF-ELISA) was constructed for detecting tricaine based on two MnO2 nanoflake-mediated (MnO2 NFs) fluorogenic reactions. In the RF-ELISA protocol, MnO2 NFs with oxidase-like activity can trigger the formation of fluorescent 2,3-diaminophenazine (oxOPD) with an emissive peak at 570 nm from non-fluorescent o-phenylenediamine (OPD), while ascorbic acid (AA) can decompose MnO2 NFs to lose their oxidase-mimicking activity, which is accompanied by the oxidation of AA into dehydroascorbic acid (DHAA). The subsequent reaction between the generated DHAA and OPD will result in the production of 3-(1,2-dihydroxy ethyl)furo[3,4-b]quinoxalin-1(3H)-on (DFQ), which has a potent emission peak at 445 nm. By virtue of the alkaline phosphatase (ALP) labeled on the antibody, which can catalyze the production of AA from ascorbic acid 2-phosphate (AAP), the concentration of tricaine can be linked to the variation of the RF signal (F445/F570) via a competitive immunoreaction. After optimization, RF-ELISA displayed a detection limit (LOD) of 0.28 ng/mL toward tricaine (in buffer solution), which was 376-fold lower than that of the traditional colorimetric ELISA. For practical application, the LODs of RF-ELISA for tricaine detection in shrimp and tilapia samples were determined to be 2.8 and 5.6 ng/g, respectively. Recoveries for spiked shrimp and tilapia samples, as well as the validation data from LC-MS/MS, showed that RF-ELISA exhibited good accuracy, precision, and reliability. This RF-ELISA protocol opened up new ways for tricaine and other-target analyses in food safety detection.


Assuntos
Compostos de Manganês , Óxidos , Animais , Humanos , Compostos de Manganês/química , Óxidos/química , Fluorescência , Reprodutibilidade dos Testes , Cromatografia Líquida , Espectrometria de Massas em Tandem , Oxirredutases/química , Ensaio de Imunoadsorção Enzimática , Corantes , Limite de Detecção
9.
Transl Psychiatry ; 12(1): 141, 2022 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-35379771

RESUMO

The cell adhesion molecule nectin3 and its presynaptic partner nectin1 have been linked to early-life stress-related cognitive disorders, but how the nectin1-nectin3 system contributes to stress-induced neuronal, circuit, and cognitive abnormalities remains to be studied. Here we show that in neonatally stressed male mice, temporal order and spatial working memories, which require the medial entorhinal cortex (MEC)-CA1 pathway, as well as the structural integrity of CA1 pyramidal neurons were markedly impaired in adulthood. These cognitive and structural abnormalities in stressed mice were associated with decreased nectin levels in entorhinal and hippocampal subregions, especially reduced nectin1 level in the MEC and nectin3 level in the CA1. Postnatal suppression of nectin1 but not nectin3 level in the MEC impaired spatial memory, whereas conditional inactivation of nectin1 from MEC excitatory neurons reproduced the adverse effects of early-life stress on MEC-dependent memories and neuronal plasticity in CA1. Our data suggest that early-life stress disrupts presynaptic nectin1-mediated interneuronal adhesion in the MEC-CA1 pathway, which may in turn contribute to stress-induced synaptic and cognitive deficits.


Assuntos
Transtornos da Memória , Células Piramidais , Estresse Psicológico , Animais , Masculino , Camundongos , Hipocampo/metabolismo , Transtornos da Memória/etiologia , Transtornos da Memória/metabolismo , Células Piramidais/metabolismo , Memória Espacial/fisiologia , Nectinas , Adesão Celular
10.
J Alzheimers Dis ; 84(3): 1193-1218, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34657881

RESUMO

BACKGROUND: Studies suggest that general anesthetics like isoflurane and sevoflurane may aggravate Alzheimer's disease (AD) neuropathogenesis, e.g., increased amyloid-ß (Aß) protein aggregation resulting in synaptotoxicity and cognitive dysfunction. Other studies showed neuroprotective effects, e.g., with xenon. OBJECTIVE: In the present study, we want to detail the interactions of inhalational anesthetics with Aß-derived pathology. We hypothesize xenon-mediated beneficial mechanisms regarding Aß oligomerization and Aß-mediated neurotoxicity on processes related to cognition. METHODS: Oligomerization of Aß1-42 in the presence of anesthetics has been analyzed by means of TR-FRET and silver staining. For monitoring changes in neuronal plasticity due to anesthetics and Aß1-42, Aß1-40, pyroglutamate-modified amyloid-(AßpE3), and nitrated Aß (3NTyrAß), we quantified long-term potentiation (LTP) and spine density. We analyzed network activity in the hippocampus via voltage-sensitive dye imaging (VSDI) and cognitive performance and Aß plaque burden in transgenic AD mice (ArcAß) after anesthesia. RESULTS: Whereas isoflurane and sevoflurane did not affect Aß1-42 aggregation, xenon alleviated the propensity for aggregation and partially reversed AßpE3 induced synaptotoxic effects on LTP. Xenon and sevoflurane reversed Aß1-42-induced spine density attenuation. In the presence of Aß1-40 and AßpE3, anesthetic-induced depression of VSDI-monitored signaling recovered after xenon, but not isoflurane and sevoflurane removal. In slices pretreated with Aß1-42 or 3NTyrAß, activity did not recover after washout. Cognitive performance and plaque burden were unaffected after anesthetizing WT and ArcAß mice. CONCLUSION: None of the anesthetics aggravated Aß-derived AD pathology in vivo. However, Aß and anesthetics affected neuronal activity in vitro, whereby xenon showed beneficial effects on Aß1-42 aggregation, LTP, and spine density.


Assuntos
Doença de Alzheimer/fisiopatologia , Anestésicos Inalatórios/administração & dosagem , Isoflurano/administração & dosagem , Placa Amiloide/fisiopatologia , Peptídeos beta-Amiloides/metabolismo , Animais , Modelos Animais de Doenças , Hipocampo/fisiopatologia , Masculino , Camundongos , Camundongos Transgênicos , Plasticidade Neuronal/efeitos dos fármacos , Neurônios/metabolismo , Fármacos Neuroprotetores/farmacologia , Xenônio/administração & dosagem
11.
Insect Sci ; 28(6): 1651-1663, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33063466

RESUMO

Phenotypic plasticity is observed in many animal species and it is effective for them to cope with many types of environmental threats. The multicolored Asian ladybird Harmonia axyridis shows a cuticular pigmentation plasticity that can be rapidly induced by temperature changes, and in the form of changeable melanin spot patterns to adjust heat-absorbing. Here, H. axyridis with thermal stimulation were selected for determining the molecular regulations behind it. First, we confirmed the melanin level changes of H. axyridis pupa could be induced by temperature, and then screened the efficient time window for thermal sensing of H. axyridis pre-pupa; it is suggested that the late stage of pre-pupa (late stage of 4th instar larva) is the critical period to sense thermal signals and adjust its pupal melanin spot area size to adapt to upcoming thermal conditions. The Ha-ADC (aspartate decarboxylase) and Ha-ebony (NBAD synthase) of aspartate-ß-alanine-NBAD pathway were then proved in regulation of cuticular melanization for pupa through RNA interference experiments; knockdown of these two genes enlarged the melanin spot size. Finally, we designed a random injection of Ha-ADC at different pre-pupal stages, to further study the regulation window during this process. Combined with all evidence observed, we suggested the spot size determination can be regulated very close to the time point of pupation, and genes of the aspartate-ß-alanine-NBAD pathway play an important role at the molecular level. In brief, H. axyridis exhibits a flexible active physiological regulation through transcriptional modification to thermal changes.


Assuntos
Ácido Aspártico , Besouros , Melaninas , Pigmentação , beta-Alanina , Adaptação Fisiológica , Animais , Fenótipo , Pupa , Temperatura
12.
Insect Sci ; 28(4): 965-975, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32452090

RESUMO

The ladybird Harmonia axyridis is an insect that exhibits pupal attachment to plants, which facilitates development and environmental adaptation. The cremaster is highly specialized for this behavior. However, the underlying molecular regulation of the cremaster remains unclear; therefore, we performed experiments to investigate the transcriptional regulation of cremaster development. First, we examined the morphological structure of the cremaster to reveal its function in pupal attachment of H. axyridis. Next, we analyzed the Hox gene Ha-Abd-B using RNA interference (RNAi) to determine its function in regulating cremaster formation; Ha-Abd-B up-regulation promoted effective pupal attachment, whereas successful RNAi caused severe down-regulation of this gene, and pupae were unable to attach. Furthermore, successful RNAi and subsequent Ha-Abd-B down-regulation caused phenotypic changes in cremaster structure, including its complete disappearance from some individuals. Finally, we observed unique development of the cremaster and dynamic expression of Ha-Abd-B during pre-pupal development; consequently, we hypothesized that there was specific pre-pupal development of the cremaster. Overall, based on these results, the specialized cremasteric structure located on the posterior side of H. axyridis was determined to be a key organ for pupal attachment. Cremaster identification in H. axyridis is regulated by Ha-Abd-B and exhibits preferential development. Pupal attachment of H. axyridis reveals an environmental adaptation of this species; thus, this study and future molecular studies will help determine the role of Hox genes in regulation of insect attachment and further our understanding of the multiple functions of Hox genes.


Assuntos
Besouros , Proteínas de Homeodomínio/genética , Abdome/anatomia & histologia , Animais , Besouros/anatomia & histologia , Besouros/embriologia , Besouros/genética , Besouros/fisiologia , Regulação da Expressão Gênica , Larva/anatomia & histologia , Larva/fisiologia , Pupa/anatomia & histologia , Pupa/fisiologia , Interferência de RNA
13.
Nat Commun ; 11(1): 6045, 2020 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-33247136

RESUMO

Touch can positively influence cognition and emotion, but the underlying mechanisms remain unclear. Here, we report that tactile experience enrichment improves memory and alleviates anxiety by remodeling neurons along the dorsoventral axis of the dentate gyrus (DG) in adult mice. Tactile enrichment induces differential activation and structural modification of neurons in the dorsal and ventral DG, and increases the presynaptic input from the lateral entorhinal cortex (LEC), which is reciprocally connected with the primary somatosensory cortex (S1), to tactile experience-activated DG neurons. Chemogenetic activation of tactile experience-tagged dorsal and ventral DG neurons enhances memory and reduces anxiety respectively, whereas inactivation of these neurons or S1-innervated LEC neurons abolishes the beneficial effects of tactile enrichment. Moreover, adulthood tactile enrichment attenuates early-life stress-induced memory deficits and anxiety-related behavior. Our findings demonstrate that enriched tactile experience retunes the pathway from S1 to DG and enhances DG neuronal plasticity to modulate cognition and emotion.


Assuntos
Ansiedade/fisiopatologia , Giro Denteado/fisiopatologia , Memória/fisiologia , Tato/fisiologia , Animais , Comportamento Animal/fisiologia , Espinhas Dendríticas/fisiologia , Córtex Entorrinal/fisiopatologia , Feminino , Integrases/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Plasticidade Neuronal/fisiologia , Neurônios/fisiologia , Sinapses/fisiologia , Fatores de Tempo
14.
Front Cell Dev Biol ; 8: 311, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32432113

RESUMO

Maternal phenotypic regulations between different generations of aphid species help aphids to adapt to environmental challenges. The pea aphid Acyrthosiphon pisum has been used as a biological model for studies on phenotypic regulation for adaptation, and its alternative phenotypes are typically and physiologically based on maternal effects. We have observed an artificially induced and host-related maternal effect that may be a new aspect to consider in maternal regulation studies using A. pisum. Marked phenotypic changes in the cuticular melanization of daughter A. pisum were detected via tyrosine hydroxylase knockdown in the mothers during their period of host plants alternations. This phenotypic change was found to be both remarkable and repeatable. We performed several studies to understand its regulation and concluded that it may be controlled via the dopamine pathway. The downregulation and phenotypes observed were verified and described in detail. Additionally, based on histological and immunofluorescence analyses, the phenotypic changes caused by cuticular dysplasia were physiologically detected. Furthermore, we found that this abnormal development could not be reversed after birth. Transcriptome sequencing confirmed that this abnormal development represents a systemic developmental failure with numerous transcriptional changes, and chemical interventions suggested that transgenerational signals were not transferred through the nervous system. Our data show that transgenerational regulation (maternal effect) was responsible for the melanization failure. The developmental signals were received by the embryos from the mother aphids and were retained after birth. APTH RNAi disrupted the phenotypic determination process. We demonstrate that non-neuronal dopamine regulation plays a crucial role in the transgenerational phenotypic regulation of A. pisum. These results enhance our understanding of phenotyping via maternal regulation in aphids.

15.
Front Cell Dev Biol ; 8: 300, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32457902

RESUMO

Animals have developed numerous strategies to contend with environmental pressures. We observed that the same adaptation strategy may be used repeatedly by one species in response to a certain environmental challenge. The ladybird Harmonia axyridis displays thermal phenotypic plasticity at different developmental stages. It is unknown whether these superficially similar temperature-induced specializations share similar physiological mechanisms. We performed various experiments to clarify the differences and similarities between these processes. We examined changes in the numbers and sizes of melanic spots in pupae and adults, and confirmed similar patterns for both. The dopamine pathway controls pigmentation levels at both developmental stages of H. axyridis. However, the aspartate-ß-alanine pathway controls spot size and number only in the pupae. An upstream regulation analysis revealed the roles of Hox genes and elytral veins in pupal and adult spot formation. Both the pupae and the adults exhibited similar morphological responses to temperatures. However, they occurred in different body parts and were regulated by different pathways. These phenotypic adaptations are indicative of an effective thermoregulatory system in H. axyridis and explains how insects contend with certain environmental pressure based on various control mechanisms.

16.
Front Physiol ; 10: 197, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30890958

RESUMO

The pea aphid, Acyrthosiphon pisum (Harris), shows body color shifting from red to pale under starvation in laboratory conditions. These body color changes reflect aphid's adaptation to environmental stress. To understand the color-shifting patterns, the underlying mechanism and its biological or ecological functions, we measured the process of A. pisum's body color shifting patterns using a digital imagery and analysis system; we conducted a series of biochemical experiments to determine the mechanism that causes color change and performed biochemical and molecular analyses of the energy reserves during the color shifting process. We found that the red morph of A. pisum could shift their body color to pale red, when starved; this change occurred rapidly at a certain stress threshold. Once A. pisum initiated the process, the shifting could not be stopped or reversed even after food was re-introduced. We also discovered that the orange-red pigments may be responsible for the color shift and that the shift might be caused by the degradation of these pigments. The carbohydrate and lipid content correlated to the fading of color in red A. pisum. A comparative analysis revealed that these reddish pigments might be used as backup energy. The fading of color reflects a reorganization of the energy reserves under nutritional stress in A. pisum; surprisingly, aphids with different body colors exhibit diverse strategies for storage and consumption of energy reserves.

17.
J Insect Physiol ; 114: 136-144, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30904400

RESUMO

Melanism in insects is important for their physical protection, immunoreactions, and sclerotization. The vetch aphid, Megoura viciae (Buckton), has relatively strong tanning in its prothorax, head, antennae, cornicles, and legs. It was hypothesized that M. viciae may sequester the high level of l-DOPA in its host Vicia faba to help in its melanization process for ecological adaptation. To confirm this hypothesis, the amount of l-DOPA in M. viciae was modified and quantified. We first generated a Trifolium repens (clover, low l-DOPA containing) host to cut off the extra l-DOPA intake by M. viciae. The rate-limiting tyrosine hydroxylase gene of M. viciae (MV-TH) was then cloned and analyzed. To further reduce the l-DOPA level in the insect, RNAi was used to downregulate the transcriptional level of MV-TH. Our results confirmed that M. viciae could indeed sequester l-DOPA in its body, and its ample storage of this amino acid could be the reason for the strong tanning of its body. M. viciae reared on T. repens could upregulate its MV-TH to enhance l-DOPA biosynthesis and thus maintain a high level of l-DOPA. The MV-TH repression by RNAi lasted for about 3 days, successfully decreasing the l-DOPA level. Aside from a slight decrease in exuvia tanning, no other obvious change in body appearance was detected in the RNAi-treated insect. Although M. viciae can obtain most of its l-DOPA directly from its original host, its internal l-DOPA synthetase is still functional, especially when extra l-DOPA is removed from the diet. This capability to enhance its shield ensures the ecological adaptation of this insect.


Assuntos
Afídeos/metabolismo , Levodopa/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismo , Sequência de Aminoácidos , Animais , Afídeos/genética , Afídeos/crescimento & desenvolvimento , Melaninas/metabolismo , Tirosina 3-Mono-Oxigenase/genética , Vicia faba
18.
J Magn Reson Imaging ; 50(2): 397-409, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30589158

RESUMO

BACKGROUND: Accurate estimation of the recurrence of pancreatic neuroendocrine tumors help with prognosis, guide follow-up, and avoid futile treatments. PURPOSE: To investigate whether MRI features could preoperatively estimate the recurrence of pancreatic neuroendocrine tumors (PNETs) and to refine a novel prognostic model through developing a nomogram incorporating various MRI features. STUDY TYPE: Retrospective. POPULATION: In all, 81 patients with clinicopathologically confirmed nonmetastatic PNETs. FIELD STRENGTH/SEQUENCES: 1.5 T MR, including T1 -weighted, T2 -weighted, and diffusion-weighted imaging sequences. ASSESSMENT: Qualitative and quantitative MRI features of PNET were assessed by three experienced radiologists. STATISTICAL TESTS: Uni- and multivariable analyses for recurrence-free survival (RFS) were evaluated using a Cox proportional hazards model. The MRI-based nomogram was then designed based on multivariable logistic analysis in our study and the performance of the nomogram was validated according to C-index, calibration, and decision curve analyses. RESULTS: MRI features, including tumor size (hazard ratio [HR]: 14.131; P = 0.034), enhancement pattern (HR: 21.821, P = 0.032), and the apparent diffusion coefficient (ADC) values (HR: 0.055, P = 0.038) were significant independent predictors of RFS at multivariable analysis. The performance of the nomogram incorporating various MRI features (with a C-index of 0.910) was improved compared with that based on tumor size, enhancement pattern, and ADC alone (with C-index values of 0.672, 0.851, and 0.809, respectively). The calibration curve of the nomogram exhibited perfect consistency between estimation and observation at 0.5, 1, and 2 years after surgery. The decision curve showed that a nomogram incorporating three features had more favorable clinical predictive usefulness than any single feature. DATA CONCLUSION: MRI features can be considered effective recurrence predictors for PNETs after surgery. The preliminary nomogram incorporating various MRI features could assess the risk of recurrence in PNETs and may be used to optimize individual treatment strategies. LEVEL OF EVIDENCE: 4 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:397-409.


Assuntos
Imageamento por Ressonância Magnética , Tumores Neuroendócrinos/diagnóstico por imagem , Nomogramas , Neoplasias Pancreáticas/diagnóstico por imagem , Adulto , Idoso , Algoritmos , Calibragem , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Tumores Neuroendócrinos/cirurgia , Neoplasias Pancreáticas/cirurgia , Prognóstico , Reprodutibilidade dos Testes , Estudos Retrospectivos , Risco , Adulto Jovem
19.
Neuropharmacology ; 135: 474-486, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29626564

RESUMO

Exposure to severely stressful experiences disrupts the activity of neuronal circuits and impairs declarative memory. GABAergic interneurons coordinate neuronal network activity, but their involvement in stress-evoked memory loss remains to be elucidated. Here, we provide evidence that interneurons in area CA1 of the dorsal hippocampus partially modulate acute stress-induced memory deficits. In adult male mice, both acute forced swim stress and restraint stress impaired hippocampus-dependent spatial memory and increased the density of c-fos-positive interneurons in the dorsal CA1. Selective activation of dorsal CA1 interneurons by chemogenetics disrupted memory performance in the spatial object recognition task. In comparison, anxiety-related behavior, spatial working memory and novel object recognition memory remained intact when dorsal CA1 interneurons were overactivated. Moreover, chemogenetic activation of dorsal CA1 interneurons suppressed the activity of adjacent pyramidal neurons, whereas a single exposure to forced swim stress but not restraint stress increased the activity of CA1 pyramidal neurons. However, chemogenetic inhibition of dorsal CA1 interneurons led to spatial memory impairments and failed to attenuate acute stress-induced memory loss. These findings suggest that acute stress may overactivate interneurons in the dorsal CA1, which reduces the activity of pyramidal neurons and in turn disrupts long-term memory.


Assuntos
Região CA1 Hipocampal/fisiopatologia , Interneurônios/fisiologia , Transtornos da Memória/etiologia , Transtornos da Memória/fisiopatologia , Memória Espacial/fisiologia , Estresse Psicológico/fisiopatologia , Animais , Ansiedade/etiologia , Ansiedade/fisiopatologia , Masculino , Memória de Curto Prazo/fisiologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células Piramidais/fisiologia , Distribuição Aleatória , Reconhecimento Psicológico/fisiologia , Estresse Psicológico/complicações
20.
Cell Rep ; 21(4): 891-900, 2017 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-29069596

RESUMO

Calbindin modulates intracellular Ca2+ dynamics and synaptic plasticity. Reduction of hippocampal calbindin levels has been implicated in early-life stress-related cognitive disorders, but it remains unclear how calbindin in distinct populations of hippocampal neurons contributes to stress-induced memory loss. Here we report that early-life stress suppressed calbindin levels in CA1 and dentate gyrus (DG) neurons, and calbindin knockdown in adult CA1 or DG excitatory neurons mimicked early-life stress-induced memory loss. In contrast, calbindin knockdown in CA1 interneurons preserved long-term memory even after an acute stress challenge. These results indicate that the dysregulation of calbindin in hippocampal excitatory, but not inhibitory, neurons conveys susceptibility to stress-induced memory deficits. Moreover, calbindin levels were downregulated by early-life stress through the corticotropin-releasing hormone receptor 1-nectin3 pathway, which in turn reduced inositol monophosphatase levels. Our findings highlight calbindin as a molecular target of early-life stress and an essential substrate for memory.


Assuntos
Região CA1 Hipocampal/metabolismo , Calbindinas/metabolismo , Interneurônios/metabolismo , Transtornos da Memória/metabolismo , Estresse Psicológico/metabolismo , Animais , Região CA1 Hipocampal/citologia , Região CA1 Hipocampal/fisiologia , Calbindinas/genética , Giro Denteado/citologia , Giro Denteado/metabolismo , Giro Denteado/fisiologia , Interneurônios/fisiologia , Masculino , Transtornos da Memória/etiologia , Memória de Longo Prazo , Camundongos , Camundongos Endogâmicos C57BL , Nectinas/metabolismo , Receptores de Hormônio Liberador da Corticotropina/metabolismo , Memória Espacial , Estresse Psicológico/complicações
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