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PURPOSE: Deep learning (DL) models have been shown to outperform total perfusion deficit (TPD) quantification in predicting obstructive coronary artery disease (CAD) from myocardial perfusion imaging (MPI). However, previously published methods have depended on polar maps, required manual correction, and normal database. In this study, we propose a polar map-free 3D DL algorithm to predict obstructive disease. METHODS: We included 1861 subjects who underwent MPI using cadmium-zinc-telluride camera and subsequent coronary angiography. The subjects were divided into parameterization and external validation groups. We implemented a fully automatic algorithm to segment myocardium, perform registration, and apply normalization. We further flattened the image based on spherical coordinate system transformation. The proposed model consisted of a component to predict patent arteries and a component to predict disease in each vessel. The model was cross-validated in the parameterization group, and then further tested using the external validation group. The performance was assessed by area under receiver operating characteristic curves (AUCs) and compared with TPD. RESULTS: Our algorithm preprocessed all images accurately as confirmed by visual inspection. In patient-based analysis, the AUC of the proposed model was significantly higher than that for stress-TPD (0.84 vs 0.76, p < 0.01). In vessel-based analysis, the proposed model also outperformed regional stress-TPD (AUC = 0.80 vs 0.72, p < 0.01). The addition of quantitative images did not improve the performance. CONCLUSIONS: Our proposed polar map-free 3D DL algorithm to predict obstructive CAD from MPI outperformed TPD and did not require manual correction or a normal database.
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Enfermedad de la Arteria Coronaria , Aprendizaje Profundo , Imagen de Perfusión Miocárdica , Humanos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Tomografía Computarizada de Emisión de Fotón Único/métodos , Angiografía Coronaria/métodos , Imagen de Perfusión Miocárdica/métodos , Algoritmos , Perfusión , CadmioRESUMEN
BACKGROUND: Carcinoembryonic antigen (CEA) is a broad-spectrum tumor marker for differential diagnosis, monitoring, and response assessment of a variety of malignancies. AIM: To evaluate whether serum CEA could predict the prognosis in patients with colorectal cancer liver metastasis (CRCLM) before and after liver resection (LR). METHODS: PubMed, Embase, Cochrane, and Web of Science were systematically searched to retrieve literature, with a search cut-off date of February 27, 2023. Articles were strictly screened for inclusion according to pre-specified inclusion and exclusion criteria. Data were pooled and analyzed using Stata 16.0. RESULTS: This meta-analysis included 36 studies involving a total of 11143 CRCLM patients. The results showed that a high pre-LR serum CEA level was correlated with poor overall survival (OS) [hazard ratio (HR) = 1.61, 95% confidence interval (CI): 1.49-1.75, P < 0.001] and recurrence-free survival (HR = 1.27, 95%CI: 1.11-1.45, P < 0.001) in CRCLM patients. A high post-LR serum CEA level predicted poor OS (HR = 2.66, 95%CI: 2.10-3.38, P < 0.001). A comparison by treatment modality, analysis modality, patient source, and cutoff-value showed that overall, high preoperative and postoperative serum CEA levels remained correlated with a poor prognosis. CONCLUSION: This study concluded that high pre-LR and post-LR serum CEA levels were significantly correlated with a poor prognosis in CRCLM patients.
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This paper develops a new method for interactive multi-criteria group decision-making (MCGDM) with probabilistic linguistic information and applies to the emergency assistance area selection of COVID-19 for Wuhan. First, a new possibility degree for PLTSs is defined and a new possibility degree algorithm is devised to rank a series of probabilistic linguistic term sets (PLTSs). Second, some new operational laws of PLTSs based on the Archimedean copulas and co-copulas are defined. A generalized probabilistic linguistic Choquet (GPLC) operator and a generalized probabilistic linguistic hybrid Choquet (GPLHC) operator are developed and their desirable properties are discussed in details. Third, a tri-objective nonlinear programming model is constructed to determine the weights of DMs. This model is transformed into a linear programming model to solve. The fuzzy measures of criterion subsets are derived objectively by establishing a goal programming model. Fourth, using the probabilistic linguistic Gumbel weighted average (PLGWA) operator, the collective normalized decision matrix is obtained by aggregating all individual normalized decision matrices. The overall evaluation values of alternatives are derived by the probabilistic linguistic Gumbel hybrid Choquet (PLGHC) operator. The ranking order of alternatives is generated. Finally, an emergency assistance example is illustrated to validate the proposed method of this paper.
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A bacterial strain, designated Jyi-02T, was isolated from a flooded rice field in Taiwan and characterized using the polyphasic taxonomy approach. Cells of strain Jyi-02T were aerobic, Gram-stain-negative, rod-shaped, non-motile and formed yellowish orange coloured colonies. Growth occurred at 10-40 °C (optimum, 20 °C) and pH 5.0-9.0 (optimum, pH 7.0) and in the presence of 0-1.0â% NaCl (optimum, 0â%, w/v). The major fatty acids (>10â%) of strain Jyi-02T were C18â:â1ω7c, summed feature 3 (C16â:â1ω7c and/or C16â:â1ω6c) and C14â:â0 2-OH. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol, phosphatidyldimethylethanolamine, sphingoglycolipid, an uncharacterized phospholipid and an uncharacterized lipid. The major polyamine was spermidine. The major isoprenoid quinone was Q-10. The DNA G+C content was 64.8 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain Jyi-02T belonged to the genus Novosphingobium and had closest phylogenetic similarity to Novosphingobium soli CC-TPE-1T (97.8â%). The DNA-DNA relatedness of strain Jyi-02T with respect to valid published species of the genus Novosphingobium was less than 35â%. Phenotypic characteristics of the novel strain also differed from those of the closest related species of the genus Novosphingobium. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain Jyi-02T represents a novel species in the genus Novosphingobium, for which the name Novosphingobium arvoryzae sp. nov. is proposed. The type strain is Jyi-02T (=BCRC 80537T=KCTC 32422T).
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Oryza/microbiología , Filogenia , Microbiología del Suelo , Sphingomonadaceae/clasificación , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Fosfolípidos/química , Pigmentación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Espermidina/química , Sphingomonadaceae/genética , Sphingomonadaceae/aislamiento & purificación , TaiwánRESUMEN
A bacterial strain, designated TPY-10T, was isolated from calla lily roots in Taiwan and characterized by using a polyphasic taxonomy approach. Cells of strain TPY-10T were Gram-stain-negative, strictly aerobic, motile and creamy white rods. Growth occurred at 15-35 °C (optimum, 25-30 °C), at pH 6-7 (optimum, pH 6) and with 0-1â% NaCl (optimum, 0â%). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain TPY-10T belonged to the genus Cellvibrio and was most closely related to Cellvibriomixtus ACM 2601T with sequence similarity of 97.8â%. Strain TPY-10T contained C16â:â0, summed feature 3 (C16â:â1ω7c and/or C16â:â1ω6c) and C18â:â1ω7c as the predominant fatty acids. The only isoprenoid quinone was Q-9. The major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The DNA G+C content of the genomic DNA was 49.8 mol%. The DNA-DNA hybridization value for strain TPY-10T with Cellvibriomixtus ACM 2601T was less than 21â%. On the basis of the phylogenetic inference and phenotypic data, strain TPY-10T should be classified as a novel species, for which the name Cellvibrio zantedeschiae sp. nov. is proposed. The type strain is TPY-10T (=BCRC 80525T=LMG 27291T=KCTC 32239T).
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Cellvibrio/clasificación , Filogenia , Raíces de Plantas/microbiología , Zantedeschia/microbiología , Técnicas de Tipificación Bacteriana , Composición de Base , Cellvibrio/genética , Cellvibrio/aislamiento & purificación , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Taiwán , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMEN
A bacterial strain designated Tese-5T was isolated from a water convolvulus field in Taiwan and characterized using the polyphasic taxonomic approach. Strain Tese-5T was an aerobic, Gram-stain-negative, non-motile, rod-shaped bacterium and formed bright yellow coloured colonies. Strain Tese-5T grew at 15-35 °C (optimum, 30 °C), with 0-1.0â% NaCl (optimum, 0-0.5â%) and at pH 5.5-7 (optimum, pH 6). The major fatty acids (>10â%) of strain Tese-5T were C18â:â1ω7c, summed feature 3 (C16â:â1ω7c and/or C16â:â1ω6c) and C16â:â0. The polar lipid profile comprised phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylcholine, phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine and sphingoglycolipid. The major polyamine was spermidine. The major isoprenoid quinone was Q-10. The DNA G+C content was 65.7 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain Tese-5T belonged to the genus Novosphingobium and showed the highest levels of sequence similarity to Novosphingobium chloroacetimidivorans BUT-14T and Novosphingobium mathurense SM117T (96.3â%). Phenotypic characteristics of the novel strain also differed from those of the closest-related species of the genus Novosphingobium. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain Tese-5T represents a novel species in the genus Novosphingobium, for which the name Novosphingobium ipomoeaesp. nov. is proposed. The type strain is Tese-5T (=BCRC 80904T=LMG 28838T=KCTC 42656T).
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Convolvulus/microbiología , Filogenia , Sphingomonadaceae/clasificación , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Espermidina/química , Sphingomonadaceae/genética , Sphingomonadaceae/aislamiento & purificación , Taiwán , Ubiquinona/químicaRESUMEN
A novel bacterial strain, designated Teta-03T, was isolated from a taro field in Taiwan and characterized using a polyphasic taxonomic approach. Cells of strain Teta-03T were aerobic, Gram-stain-negative, rod-shaped and non-motile and formed bright yellow colonies. Growth occurred at 10-37 °C (optimum, 20 °C), with 0-1.0 % (w/v) NaCl (optimum, 0 %) and at pH 3.0-9.0 (optimum, pH 7.0-8.0). The major fatty acids (>10 %) of strain Teta-03T were C18 : 1ω7c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine, sphingoglycolipid, phosphatidylcholine, an uncharacterized glycolipid and an uncharacterized aminolipid. The major polyamine was spermidine. The major isoprenoid quinone was Q-10. The DNA G+C content was 65.0âmol%. On the basis of 16S rRNA gene sequence analysis, strain Teta-03T was shown to belong to the genus Novosphingobium and showed highest similarity to Novosphingobium barchaimii LL02T (96.8 %). Phenotypic characteristics of the novel strain also differed from those of the closest related species of the genus Novosphingobium. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain Teta-03T represents a novel species of the genus Novosphingobium, for which the name Novosphingobium colocasiae sp. nov. is proposed. The type strain is Teta-03T ( = LMG 27385T = KCTC 32255T).
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Colocasia/microbiología , Filogenia , Sphingomonadaceae/clasificación , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Pigmentación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Espermidina/química , Sphingomonadaceae/genética , Sphingomonadaceae/aislamiento & purificación , Taiwán , Ubiquinona/análogos & derivados , Ubiquinona/químicaRESUMEN
In order to identify genes involved in stress and metabolic regulation, we carried out a Drosophila P-element-mediated mutagenesis screen for starvation resistance. We isolated a mutant, m2, that showed a 23% increase in survival time under starvation conditions. The P-element insertion was mapped to the region upstream of the vha16-1 gene, which encodes the c subunit of the vacuolar-type H+-ATPase. We found that vha16-1 is highly expressed in the fly midgut, and that m2 mutant flies are hypomorphic for vha16-1 and also exhibit reduced midgut acidity. This deficit is likely to induce altered metabolism and contribute to accelerated aging, since vha16-1 mutant flies are short-lived and display increases in body weight and lipid accumulation. Similar phenotypes were also induced by pharmacological treatment, through feeding normal flies and mice with a carbonic anhydrase inhibitor (acetazolamide) or proton pump inhibitor (PPI, lansoprazole) to suppress gut acid production. Our study may thus provide a useful model for investigating chronic acid suppression in patients.
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Equilibrio Ácido-Base/genética , Proteínas de Drosophila/genética , Tracto Gastrointestinal/metabolismo , Obesidad/genética , Fenotipo , ATPasas de Translocación de Protón Vacuolares/genética , Acetazolamida/farmacología , Animales , Inhibidores de Anhidrasa Carbónica/farmacología , Proteínas de Drosophila/metabolismo , Drosophila melanogaster , Determinación de la Acidez Gástrica , Tracto Gastrointestinal/efectos de los fármacos , Lansoprazol/farmacología , Ratones , Obesidad/metabolismo , Inhibidores de la Bomba de Protones/farmacología , ATPasas de Translocación de Protón Vacuolares/metabolismoRESUMEN
The aging process is a universal phenomenon shared by all living organisms. The identification of longevity genes is important in that the study of these genes is likely to yield significant insights into human senescence. In this study, we have identified Tequila as a novel candidate gene involved in the regulation of longevity in Drosophila melanogaster. We have found that a hypomorphic mutation of Tequila (Teq(f01792)), as well as cell-specific downregulation of Tequila in insulin-producing neurons of the fly, significantly extends life span. Tequila deficiency-induced life-span extension is likely to be associated with reduced insulin-like signaling, because Tequila mutant flies display several common phenotypes of insulin dysregulation, including reduced circulating Drosophila insulin-like peptide 2 (Dilp2), reduced Akt phosphorylation, reduced body size, and altered glucose homeostasis. These observations suggest that Tequila may confer life-span extension by acting as a modulator of Drosophila insulin-like signaling.
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Proteínas de Drosophila/fisiología , Drosophila melanogaster/fisiología , Insulina/fisiología , Péptidos y Proteínas de Señalización Intercelular/fisiología , Longevidad/fisiología , Serina Endopeptidasas/fisiología , Transducción de Señal/fisiología , Animales , Femenino , Esperanza de Vida , MasculinoRESUMEN
A bacterial strain, designated Npb-02T, was isolated from a freshwater river in Taiwan and characterized in a taxonomic study using a polyphasic approach. Cells of strain Npb-02T were Gram-stain-negative, aerobic, poly-ß-hydroxybutyrate-accumulating, rod-shaped and non-motile. Growth occurred at 1540 °C (optimum 2530 °C), at pH 7.08.0 (optimum pH 7.0) and with 01 % NaCl (optimum 0.5 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain Npb-02T belonged to the genus Vogesella and was most closely related to Vogesella perlucida DS-28T with sequence similarity of 98.3 %. Strain Npb-02T contained summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0 as the major fatty acids. The major respiratory quinone was Q-8.The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an uncharacterized aminophospholipid and an uncharacterized phospholipid. The genomic DNA G+C content of strain Npb-02T was 64.1 mol%. The DNADNA hybridization values for strain Npb-02T with Vogesella perlucida DS-28T, Vogesella mureinivorans 389T and Vogesella lacus GR13T were less than 25 %. On the basis of phylogenetic inference and phenotypic data, strain Npb-02T represents a novel species of the genus Vogesella, for which the name Vogesella amnigena sp. nov. is proposed. The type strain is Npb-02T ( = BCRC 80887T = LMG 28419T = KCTC 42195T).
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Neisseriaceae/clasificación , Filogenia , Ríos/microbiología , Microbiología del Agua , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Hidroxibutiratos/química , Datos de Secuencia Molecular , Neisseriaceae/genética , Neisseriaceae/aislamiento & purificación , Hibridación de Ácido Nucleico , Fosfolípidos/química , Poliésteres/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Taiwán , Ubiquinona/químicaRESUMEN
We provide a new approach to identify the substrate influence on graphene surface. Distinguishing the substrate influences or the doping effects of charged impurities on graphene can be realized by optically probing the graphene surfaces, included the suspended and supported graphene. In this work, the line scan of Raman spectroscopy was performed across the graphene surface on the ordered square hole. Then, the bandwidths of G-band and 2D-band were fitted into the Voigt profile, a convolution of Gaussian and Lorentzian profiles. The bandwidths of Lorentzian parts were kept as constant whether it is the suspended and supported graphene. For the Gaussian part, the suspended graphene exhibits much greater Gaussian bandwidths than those of the supported graphene. It reveals that the doping effect on supported graphene is stronger than that of suspended graphene. Compared with the previous studies, we also used the peak positions of G bands, and I2D/IG ratios to confirm that our method really works. For the suspended graphene, the peak positions of G band are downshifted with respect to supported graphene, and the I2D/IG ratios of suspended graphene are larger than those of supported graphene. With data fitting into Voigt profile, one can find out the information behind the lineshapes.
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The interactions between phonons and electrons induced by the dopants or the substrate of graphene in spectroscopic investigation reveal a rich source of interesting physics. Raman spectra and surface-enhanced Raman spectra of supported and suspended monolayer graphenes were measured and analyzed systemically with different approaches. The weak Raman signals are greatly enhanced by the ability of surface-enhanced Raman spectroscopy which has attracted considerable interests. The technique is regarded as wonderful and useful tool, but the dopants that are produced by depositing metallic nanoparticles may affect the electron scattering processes of graphene. Therefore, the doping and substrate influences on graphene are also important issues to be investigated. In this work, the peak positions of G peak and 2D peak, the I2D/IG ratios, and enhancements of G and 2D bands with suspended and supported graphene flakes were measured and analyzed. The peak shifts of G and 2D bands between the Raman and SERS signals demonstrate the doping effect induced by silver nanoparticles by n-doping. The I2D/IG ratio can provide a more sensitive method to carry out the doping effect on the graphene surface than the peak shifts of G and 2D bands. The enhancements of 2D band of suspended and supported graphenes reached 138, and those of G band reached at least 169. Their good enhancements are helpful to measure the optical properties of graphene. The different substrates that covered the graphene surface with doping effect are more sensitive to the enhancements of G band with respect to 2D band. It provides us a new method to distinguish the substrate and doping effect on graphene. PACS: 78.67.Wj (optical properties of graphene); 74.25.nd (Raman and optical spectroscopy); 63.22.Rc (phonons in graphene).
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We report on a polarized Raman study on mechanically cleaved single-layer graphene films. Under a specific orientation of scattering measurement, the width and position of the G peak change with the incident polarization direction, while the integrated intensity of that is unaltered. This phenomenon is explained by a proposed mode in which the peak is contributed by a mixture of un-, compressive-, and tensile-strained G sub-modes. The compression and tension are both uniaxial and approximately perpendicular to each other. They are undesigned and located in either separated or overlapped sub-areas within the probed local region. Compared to the unstrained wavenumber of 1580 cm(-1), compression induces a blue shift while tension causes a red one. The sub-modes correlated with the light polarization through different relationships split the G peak into three sub-ones. We develop a method to quantitatively analyze the positions, widths, intensities, and polarization dependences of sub-peaks. This analysis quantitatively reveals local strain, which changes with the detected area of a graphene film. The method presented here can be extended to detect the strain distribution in the film and thus is a promising technology for graphene characterization.
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Bone morphogenetic proteins (BMPs), members of the transforming growth factor-beta (TGF-ß) superfamily, have been shown to play important roles in the nervous system, including neuronal survival and synaptogenesis. However, the physiological functions of BMP signaling in the mammalian neuromuscular system are not well understood. In this study, we found that proteins of the type II bone morphogenetic receptors (BMPRII) were detected at the neuromuscular junction (NMJ), and one of its ligands, BMP4, was expressed by Schwann cells and skeletal muscle fibers. In double-ligated nerves, BMP4 proteins accumulated at the proximal and distal portions of the axons, suggesting that Schwann cell- and muscle fiber-derived BMP4 proteins were anterogradely and retrogradely transported by motor neurons. Furthermore, BMP4 mRNA was down-regulated in nerves but up-regulated in skeletal muscles following nerve ligation. The motor neuron-muscle interactions were also demonstrated using differentiated C2C12 muscle cells and NG108-15 neurons in vitro. BMP4 mRNA and immunoreactivity were significantly up-regulated in differentiated C2C12 muscle cells when the motor neuron-derived factor, agrin, was present in the culture. Peripherally-derived BMP4, on the other hand, promotes embryonic motor neuron survival and protects NG108-15 neurons from glutamate-induced excitotoxicity. Together, these data suggest that BMP4 is a peripherally-derived factor that may regulate the survival of motor neurons.
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Proteína Morfogenética Ósea 4/metabolismo , Ácido Glutámico/toxicidad , Neuronas Motoras/efectos de los fármacos , Agrina/metabolismo , Animales , Axones/metabolismo , Receptores de Proteínas Morfogenéticas Óseas de Tipo II/metabolismo , Línea Celular , Regulación de la Expresión Génica , Humanos , Ligandos , Ratones , Ratones Endogámicos C57BL , Neuronas Motoras/metabolismo , Músculos/metabolismo , Unión Neuromuscular/metabolismo , ARN Mensajero/metabolismo , Células de Schwann/citología , Células de Schwann/metabolismo , Transducción de SeñalRESUMEN
The distributions of sizes of silver nanoparticles that were deposited on monolayer, bilayer, and trilayer graphene films were observed. Deposition was carried out by thermal evaporation and the graphene films, placed on SiO2/Si substrates, were obtained by the mechanical splitting of graphite. Before the deposition, optical microscopy and Raman spectroscopy were utilized to identify the number of the graphene layers. After the deposition, scanning electron microscopy was used to observe the morphologies of the particles. Systematic analysis revealed that the average sizes of the nanoparticles increased with the number of graphene layers. The density of nanoparticles decreased as the number of graphene layers increased, revealing a large variation in the surface diffusion strength of nanoparticles on the different substrates. The mechanisms of formation of these layer-dependent morphologies of silver on n-layer graphene are related to the surface free energy and surface diffusion of the n-layer graphene. The effect of the substrate such as SiO2/Si was investigated by fabricating suspended graphene, and the size and density were similar to those of supported graphene. Based on a comparison of the results, the different morphologies of the silver nanoparticles on different graphene layers were theorized to be caused only by the variation of the diffusion barriers with the number of layers of graphene.
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We report the strain effect of suspended graphene prepared by micromechanical method. Under a fixed measurement orientation of scattered light, the position of the 2D peaks changes with incident polarization directions. This phenomenon is explained by a proposed mode in which the peak is effectively contributed by an unstrained and two uniaxial-strained sub-areas. The two axes are tensile strain. Compared to the unstrained sub-mode frequency of 2,672 cm-1, the tension causes a red shift. The 2D peak variation originates in that the three effective sub-modes correlate with the light polarization through different relations. We develop a method to quantitatively analyze the positions, intensities, and polarization dependences of the three sub-peaks. The analysis reflects the local strain, which changes with detected area of the graphene film. The measurement can be extended to detect the strain distribution of the film and, thus, is a promising technology on graphene characterization.
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BACKGROUND: Autophagy and molecular chaperones both regulate protein homeostasis and maintain important physiological functions. Atg7 (autophagy-related gene 7) and Hsp27 (heat shock protein 27) are involved in the regulation of neurodegeneration and aging. However, the genetic connection between Atg7 and Hsp27 is not known. METHODS: The appearances of the fly eyes from the different genetic interactions with or without polyglutamine toxicity were examined by light microscopy and scanning electronic microscopy. Immunofluorescence was used to check the effect of Atg7 and Hsp27 knockdown on the formation of autophagosomes. The lifespan of altered expression of Hsp27 or Atg7 and that of the combination of the two different gene expression were measured. RESULTS: We used the Drosophila eye as a model system to examine the epistatic relationship between Hsp27 and Atg7. We found that both genes are involved in normal eye development, and that overexpression of Atg7 could eliminate the need for Hsp27 but Hsp27 could not rescue Atg7 deficient phenotypes. Using a polyglutamine toxicity assay (41Q) to model neurodegeneration, we showed that both Atg7 and Hsp27 can suppress weak, toxic effect by 41Q, and that overexpression of Atg7 improves the worsened mosaic eyes by the knockdown of Hsp27 under 41Q. We also showed that overexpression of Atg7 extends lifespan and the knockdown of Atg7 or Hsp27 by RNAi reduces lifespan. RNAi-knockdown of Atg7 expression can block the extended lifespan phenotype by Hsp27 overexpression, and overexpression of Atg7 can extend lifespan even under Hsp27 knockdown by RNAi. CONCLUSIONS: We propose that Atg7 acts downstream of Hsp27 in the regulation of eye morphology, polyglutamine toxicity, and lifespan in Drosophila.