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Sulfate-reducing bacteria (SRB) play pivotal roles in the biotransformation of mercury (Hg). However, unrevealed global responses of SRB to Hg have restricted our understanding of details of Hg biotransformation processes. The absence of protein-protein interaction (PPI) network under Hg stimuli has been a bottleneck of proteomic analysis for molecular mechanisms of Hg transformation. This study constructed the first comprehensive PPI network of SRB in response to Hg, encompassing 67 connected nodes, 26 independent nodes, and 121 edges, covering 93% of differentially expressed proteins from both previous studies and this study. The network suggested that proteomic changes of SRB in response to Hg occurred globally, including microbial metabolism in diverse environments, carbon metabolism, nucleic acid metabolism and translation, nucleic acid repair, transport systems, nitrogen metabolism, and methyltransferase activity, partial of which could cover the known knowledge. Antibiotic resistance was the original response revealed by this network, providing insights into of Hg biotransformation mechanisms. This study firstly provided the foundational network for a comprehensive understanding of SRB's responses to Hg, convenient for exploration of potential targets for Hg biotransformation. Furthermore, the network indicated that Hg enhances the metabolic activities and modification pathways of SRB to maintain cellular activities, shedding light on the influences of Hg on the carbon, nitrogen, and sulfur cycles at the cellular level.
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Mercúrio , Mercúrio/metabolismo , Mapas de Interação de Proteínas , Proteínas de Bactérias/metabolismo , Biotransformação , Sulfatos/metabolismo , Bactérias/metabolismo , Proteômica , Bactérias Redutoras de Enxofre/metabolismoRESUMO
Nifedipine is a potent antihypertensive medication classified as a dihydropyridine calcium channel blocker. The objective of this trial was to assess the bioequivalence of a 30-mg nifedipine controlled-release tablet and a reference drug in a cohort of healthy Chinese individuals. Two independent open-label, randomized, single-dose, crossover studies were conducted, 1 under fasting conditions (N = 44, with 1 participant dropping out midway) and the other under fed conditions (N = 44, with 4 participants dropping out midway). Plasma concentrations of nifedipine were determined using liquid chromatography-mass spectrometry, and pharmacokinetic (PK) parameters were calculated using noncompartmental analysis with Phoenix WinNonlin 8.0 software. In both fasting and fed studies, reasonable bioequivalence was observed for the PK parameters of both the test product and the reference drug. A good safety profile was demonstrated for both the test product and reference drug, with no serious adverse events reported, and both were similarly well tolerated. An important observation with food coadministration was that systemic exposure to nifedipine (based on area under the curve, AUC0-∞) was reduced by approximately 12%. The bioequivalence of the test product and reference drug under fasting/fed conditions in healthy subjects in China was demonstrated by the study results.
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Área Sob a Curva , Bloqueadores dos Canais de Cálcio , Estudos Cross-Over , Preparações de Ação Retardada , Jejum , Interações Alimento-Droga , Nifedipino , Comprimidos , Equivalência Terapêutica , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Administração Oral , Povo Asiático , Bloqueadores dos Canais de Cálcio/farmacocinética , Bloqueadores dos Canais de Cálcio/administração & dosagem , Bloqueadores dos Canais de Cálcio/efeitos adversos , China , População do Leste Asiático , Voluntários Saudáveis , Nifedipino/farmacocinética , Nifedipino/administração & dosagem , Nifedipino/efeitos adversosRESUMO
Introduction: The use of physical restraint (PR) is considered a controversial practice and research in Western countries has demonstrated negative physical and psychological consequences for patients, as well as staff, family members/carers, organisations and society as a whole. However, there are few research reports on restraint experiences of patients with mental disorders in non-Western countries, especially in mainland China. Aim: This study aims to explore the subjective experiences and perceptions of patients with psychiatric disorders who have experienced PR in mainland China. Methods: Semi-structured interviews were conducted with 8 inpatients with mental disorders in convalescence at a specialized mental health hospital in Shanghai. Interviews were recorded on audiotape and transcribed verbatim. Transcripts were analyzed using thematic analysis. Results: Five themes emerged: "perception and understanding of PR", "response to PR", "negative physical and psychological experiences", "unmet care needs during PR" and "changes after PR", which together characterize patients' perceptions, experiences, feelings, and needs in PR. Conclusion: The use of PR involves ethical issues and brings negative experiences to patients with mental disorders that cannot be ignored and should be used as a last resort. Different patients have different attitudes and reactions to PR. During PR, patients' physical and psychological needs are not adequately met. Medical staff should give more attention to patients in PR, meet their physical and psychological needs, and actively seek PR alternatives and reduction options based on evidence-based resources on restraint reduction available in the West and the national context and culture of China.
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Background: Physical restraint is widely used in mental health services to address safety concerns. However, studies have shown that improper physical restraint can result in adverse effects. Nurses are the main practitioners of physical restraint and play a crucial role in physical restraint decisions and nursing. In China, there is a lack of large-scale investigations into the current status of psychiatric physical restraint use. Aim: This study aims to explore the situation and influencing factors of the psychiatric nurses' knowledge, attitudes and practices regarding physical restraint in China. Methods: A cross-sectional multicenter descriptive study was conducted from December 2022 to February 2023, consecutively. A convenience sampling method was used to recruit 345 staff from three psychiatric hospitals in Shanghai. A psychiatric nurses' physical restraint use status questionnaire was administered to examine their knowledge, attitude, and practice regarding physical restraint. The data were analyzed using the Mann-Whitney U-test and the Kruskal-Wallis test. Multivariate linear stepwise regression analysis was used for multi-factor analysis. Results: Overall, nurses had a good level of knowledge with positive attitudes and adequate practices. However, they had some misunderstandings and undesirable practices. Multiple linear regression analysis revealed that educational background, position and training experience were the main factors influencing physical restraint knowledge, attitudes and practice among psychiatric nurses (p<0.05). Conclusion: This study highlights some important misconceptions and improper practices of psychiatric nurses about using physical restraint. It is necessary to strengthen education and training on physical restraint for nursing staff to reduce unnecessary physical restraint use.
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Currently, the infection of hypervirulent Klebsiella pneumoniae (hvKp) is becoming increasingly serious and the virulent mechanisms of hvKp are still not very clear. An effective gene-editing method for genes on hvKp virulence plasmid can help us reveal related virulent mechanisms. There are a few reports focusing on the methods mentioned above, however with certain limitations. In this work, we first constructed the pRE112-basing recombinant suicide plasmid to knock out or replace the genes in the hvKp virulence plasmid based on the principle of homology recombination. Results showed that the target virulent genes iucA, iucB, iroB, and rmpA2 on the hvKp virulence plasmid were scarlessly knocked out or replaced by marker genes, and mutant hvKp strains with the expected phenotypes were obtained. These indicated that we established an efficient gene-editing method for genes on hvKp virulence plasmid, which could help us explore the functions of these genes and reveal the virulent mechanisms of hvKp.
Assuntos
Infecções por Klebsiella , Klebsiella pneumoniae , Humanos , Virulência/genética , Klebsiella pneumoniae/genética , Plasmídeos/genética , Infecções por Klebsiella/tratamento farmacológico , Antibacterianos/uso terapêuticoRESUMO
Reports on multidrug-resistant hypervirulent Klebsiella pneumoniae (MDR-hvKP) in recent years indicate the wide-spreading trend of MDR-hvKP. The co-occurrence of hypervirulence and drug resistance poses a great challenge to clinical treatment. In this study, molecular characteristics of an MDR strain hvKP247 and 30 clinically isolated hvKP strains were characterized. The whole genome of hvKP247 belonging to sequence type (ST) 5214 and capsule serotype K1 was sequenced and analyzed. Conjugation experiments were performed to evaluate transferability of the plasmids in hvKP247. We found two new STs among our isolates, ST5570 and ST5571. The ST5214 hvKP247 contained two transferable plasmids: a hybrid virulence plasmid (pHvKP247-vir) carrying transfer-related modules that had self-transferable ability, and a drug-resistant plasmid (pHvKP247-MDR) that could be indirectly transferred with the help of pHvKP247-vir. The virulence-related genes were located on the pHvKP247-vir and chromosomal ICEKp1 mobile genetic element. In conclusion, the hybrid virulence plasmid and the drug-resistant plasmid are co-transferred, which emphasizes the importance of raising public awareness of the simultaneous spread of virulence and resistance genes of MDR-hvKP strains.
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Infecções por Klebsiella , Klebsiella pneumoniae , Antibacterianos/farmacologia , Humanos , Infecções por Klebsiella/tratamento farmacológico , Plasmídeos/genética , Virulência/genéticaRESUMO
Nanomaterials play a crucial role in various areas due to their extraordinary chemical and physical properties. Loading microscopic nanomaterials onto macrostructures is inevitable for their implementation from laboratory experiments to practical applications. Nevertheless, the geometries of conventional supporting structures are usually limited and nanomaterials are easy to be inhomogeneously distributed, aggregated, and lost. Therefore, controllably configuring nanomaterials into sophisticated three-dimensional macroscopic structures without sacrificing their inherent properties remains challenging. Here we utilize the advantages of 3D printing technology to realize this purpose. As a proof-of-concept, the application of 3D stereolithography printed macrostructures containing TiO2 nano particles (TiO2 NPs) for direct adsorption removal of As(III) in water was demonstrated. The morphology and distribution of TiO2 NPs mounted on printed macrostructures were initially characterized. Then batch adsorption experiments were conducted to investigate the effect of the 3D printing process, TiO2 NPs doped concentration and TiO2 NP size as well as adsorption kinetics and isotherms. We also demonstrated that 3D printed adsorption structures could be easily reused over 10 times and were effective for raw arsenic-polluted groundwater samples. Our findings show that 3D printing provides a promising route to design and fabricate customized macrostructures endowed with specific properties of nanomaterials.
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Purificação da Água , Água , Impressão Tridimensional , TitânioRESUMO
A single-dose, open-label, randomized-sequence, 2×2 crossover study was conducted in healthy Chinese adults, after fasting and postprandial, to evaluate the bioequivalence of 2 pyrazinamide (PZA) formulations. Fasting and postprandial tests were conducted in 24 cases. Test-reference and reference-test were randomly divided into 2 sequence groups, with 12 cases in each group. The concentration of PZA in plasma was determined after 0.5 g single oral PZA test and reference formulations by the high-performance liquid chromatography-tandem mass spectrometry method. In the fasting group, the 90% confidence intervals (CIs) of the 2 formulations maximum plasma concentration (Cmax ), area under the plasma concentration-time curve (AUC) from time 0 to last detectable plasma concentration, and AUC from time 0 to infinity after logarithmic conversion were 104.8% to 121.9%, 97.7% to 101.6%, and 97.7% to 101.6%, respectively. In the postprandial group, the 90%CIs of the 2 formulations' Cmax , AUC from time 0 to last detectable plasma concentration, and AUC from time 0 to infinity after logarithmic conversion were 86.4% to 100.2%, 96% to 102%, 95.8% to 102.3%, respectively. The 90%CIs of the test/reference Cmax ratio and AUC ratio were within the acceptable range of 80.00% to 125.00% for bioequivalence under both fasting and postprandial conditions. No serious adverse events occurred during treatment with the test formulation or the reference formulation.
Assuntos
Pirazinamida , Espectrometria de Massas em Tandem , Adulto , China , Estudos Cross-Over , Humanos , Pirazinamida/efeitos adversos , Pirazinamida/farmacocinética , Comprimidos , Espectrometria de Massas em Tandem/métodos , Equivalência TerapêuticaRESUMO
BACKGROUND: The effect of SARS-CoV-2 on existing respiratory pathogens in circulation remains uncertain. This study aimed to assess the impact of SARS-CoV-2 on the prevalence of respiratory pathogens among hospitalized children. METHODS: This study enrolled hospitalized children with acute respiratory infections in Shenzhen Children's Hospital from September to December 2019 (before the COVID-19 epidemic) and those from September to December 2020 (during the COVID-19 epidemic). Nasopharyngeal swabs were collected, and respiratory pathogens were detected using multiplex PCR. The absolute case number and detection rates of 11 pathogens were collected and analyzed. RESULTS: A total of 5696 children with respiratory tract infection received multiplex PCR examination for respiratory pathogens: 2298 from September to December 2019 and 3398 from September to December 2020. At least one pathogen was detected in 1850 (80.5%) patients in 2019, and in 2380 (70.0%) patients in 2020; the detection rate in 2020 was significantly lower than that in 2019.The Influenza A (InfA) detection rate was 5.6% in 2019, but 0% in 2020. The detection rates of Mycoplasma pneumoniae, Human adenovirus, and Human rhinovirus also decreased from 20% (460), 8.9% (206), and 41.8% (961) in 2019 to 1.0% (37), 2.1% (77), and 25.6% (873) in 2020, respectively. In contrast, the detection rates of Human respiratory syncytial virus, Human parainfluenza virus, and Human metapneumovirus increased from 6.6% (153), 9.9% (229), and 0.5% (12) in 2019 to 25.6% (873), 15.5% (530), and 7.2% (247) in 2020, respectively (p < 0.0001). CONCLUSIONS: Successful containment of seasonal influenza as a result of COVID-19 control measures will ensure we are better equipped to deal with future outbreaks of both influenza and COVID-19.Caused by virus competition, the detection rates of Human respiratory syncytial virus, Human parainfluenza virus, and Human metapneumovirus increased in Shenzhen,that reminds us we need to take further monitoring and preventive measures in the next epidemic season.
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Antibiose , COVID-19/epidemiologia , Doenças Respiratórias/epidemiologia , SARS-CoV-2/isolamento & purificação , Adenovírus Humanos/genética , Adenovírus Humanos/isolamento & purificação , Adolescente , COVID-19/virologia , Criança , Criança Hospitalizada , Pré-Escolar , China , Enterovirus/genética , Enterovirus/isolamento & purificação , Feminino , Humanos , Lactente , Vírus da Influenza A/genética , Vírus da Influenza A/isolamento & purificação , Masculino , Metapneumovirus/genética , Metapneumovirus/isolamento & purificação , Mycoplasma pneumoniae/genética , Mycoplasma pneumoniae/isolamento & purificação , Nasofaringe/microbiologia , Nasofaringe/virologia , Prevalência , Vírus Sinciciais Respiratórios/genética , Vírus Sinciciais Respiratórios/isolamento & purificação , Doenças Respiratórias/microbiologia , Doenças Respiratórias/virologia , Respirovirus/genética , Respirovirus/isolamento & purificação , SARS-CoV-2/genéticaRESUMO
INTRODUCTION: This study aimed to examine the medication prescriptions for hypertension in a class 1 and grade A hospital in Shanxi province to provide references for clinical rational drug use. METHODS: An inpatient medical record inquiry system was used to evaluate the use of antihypertensives in a hypertensive population (age ≥ 18 years old) who received a prescription for one or more antihypertensives between January 2017 and December 2019. The hypertensive population was categorized into grades (1, 2, and 3), age groups, and different comorbidities to analyze the medication prescriptions. Drug analysis included angiotensin-converting enzyme inhibitor (ACEI), angiotensin receptor antagonist (ARB), calcium channel blocker (CCB), diuretics, and beta-receptor blockers (B-RB). SPSS16.0 was used for statistical analysis, including one-way analysis of variance (ANOVA,) chi-squared test, and multifactor logistic regression analysis. RESULTS: The overall control rate of blood pressure was 60.79%. The control rates of single, double, triple, and quadruple antihypertensives were 70.08%, 59.97%, 56.27%, and 45.23%, respectively. There were more cases of grade 3 than grades 1 and 2. The 18-65 years group was larger than the 66-79 years and ≥ 80 years groups. With the increase in grade, the prescription rate of the single drug decreased and the prescription rate of the combination drug increased, but this phenomenon was not obvious in different age groups. The most common drug prescribed for monotherapy was CCB; CCB combined with B-RB had the highest drug use in the double group by age or grade. Statistically significant differences were detected in the type of comorbidities between different age groups (P < 0.001), while only some differences were observed between different grades. Also, statistically significant differences were observed in the drugs prescribed for patients with hypertension with different comorbidities (P < 0.001). Factors influencing the efficiency of antihypertensives included sex, age, diabetes, heart failure, and usage of CCB and B-RB. The prescription rate of ARB combined with B-RB was relatively higher in grade 2 cases. B-RB was the primary drug for patients with diabetes, significantly increasing the blood glucose level. CONCLUSIONS: The medication prescription of this hospital was in line with the requirements of China's hypertension prevention and treatment guidelines. The pathophysiology of patients with hypertension in different age groups, increased use of combination drugs, and rational drug requirement should be considered when prescribing drugs.
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Antagonistas de Receptores de Angiotensina , Hipertensão , Adolescente , Antagonistas de Receptores de Angiotensina/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Bloqueadores dos Canais de Cálcio/uso terapêutico , Prescrições de Medicamentos , Hospitais , Humanos , Hipertensão/tratamento farmacológico , Hipertensão/epidemiologiaRESUMO
Monogenean Gyrodactylus cichlidarum can cause severe mortality of Nile tilapia (Oreochromis niloticus) fry. To date, reports about mucosal immunity of O. niloticus against this parasite have been rare. In order to explore the mucosal immunity of Nile tilapia against G. cichlidarum infection, the expressions of six adaptive immune-related genes and the contents of specific immunoglobulin IgM and IgT in the skin-associated lymphoid tissues (SALT) were dynamically analyzed after primary and secondary infections. The abundances of G. cichlidarum on the hosts after secondary infection were lower than those after primary parasite infection, which implied that hosts could initiate immune protection against G. cichlidarum reinfection to some degree. The transcription levels of TCR-ß and CD4 genes in the skin tissue were significantly up-regulated after primary G. cichlidarum infection, while genes pIgR and IgT were only detected with significant up-regulations during secondary infection. With the exception of pIgR, which had remarkably higher expression in the fish with low parasite loads, all other genes studied tended to have higher mRNA level in the fish with higher parasite loads. The specific IgM content in the skin mucus increased significantly on the 2nd day after the primary exposure, higher than the corresponding value during the secondary exposure, and had significantly positive correlation with the parasite loads during the first parasite infection. These results manifested that acquired immune responses in the SALT of Nile tilapia participated in the resistance against G. cichlidarum infection, underscoring the involvement of mucosal immunity in fish against monogenean infection, and suggesting potential prophylactic treatment of gyrodactylid disease of tilapia.
Assuntos
Ciclídeos , Doenças dos Peixes/imunologia , Imunidade nas Mucosas , Trematódeos/fisiologia , Infecções por Trematódeos/veterinária , Animais , Doenças dos Peixes/parasitologia , Infecções por Trematódeos/imunologia , Infecções por Trematódeos/parasitologiaRESUMO
Tilapias are important aquaculture fishes that have been introduced widely all over the world, often carrying their monogenean parasites with them. An extensive investigation on monogeneans of invasive tilapias was conducted in 19 natural water sources in south China between July 2015 and December 2017. We found nine known species of monogeneans, i.e., Enterogyrus coronatus, E. malmbergi, Cichlidogyrus cirratus, C. halli, C. sclerosus, C. thurstonae, C. tilapiae, Scutogyrus longicornis, Gyrodactylus cichlidarum, and one unknown Gyrodactylus species. In addition to reporting ten new hosts and four new geographical records, we observed new morphological characteristics of these species. Observation on living specimens of Enterogyrus spp. demonstrated that these two species have characteristic opisthaptoral retraction capacities, while the opisthaptor glands were not observed in our specimens of E. coronatus and E. malmbergi. The morphological differences of the accessory piece of the male copulatory complex between C. cirratus and C. mbirizei (character for species differentiation) could result from the observation at different perspectives, which indicates that C. mbirizei is likely a synonym of C. cirratus. A more detailed structure of the sclerotized parts of Cichlidogyrus spp. and S. longicornis were revealed by scanning electron microscopy. As was the case for the monogeneans found on alien tilapias from other geographic regions, the present study confirmed the high potential of these monogeneans to establish populations in new habitats.
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Tilápia/parasitologia , Trematódeos/anatomia & histologia , Animais , Aquicultura , China/epidemiologia , Doenças dos Peixes/parasitologia , Brânquias/parasitologia , Espécies Introduzidas , Lagos/parasitologia , Masculino , Microscopia , Microscopia Eletrônica de Varredura , Trematódeos/isolamento & purificação , Trematódeos/ultraestruturaRESUMO
Gyrodactylus cichlidarum and Cichlidogyrus sclerosus, two monogenean ectoparasite species commonly found on the body surface and gills of Nile tilapia (Oreochromis niloticus) respectively, inflicted considerable economic losses in intensive tilapia farming. In order to explore the immune response of tilapia against these two species of monogeneans, expression patterns of five immune-related genes were studied after singular G. cichlidarum or C. sclerosus infection and their coinfection. The transcription levels of IL-1ß were up-regulated in the skin after G. cichlidarum infection, reaching a peak at day 5 PI, and in the gills after C. sclerosus infection (peaking at day 8 PI), with significant elevation only detected in the gills after high-dose C. sclerosus infection. A trend favoring increased gill TNF-α expression at day 8 PI of C. sclerosus infection was statistically significant only in the low-dose infection group. TNF-α expression in the skin did not change significantly after G. cichlidarum infection. TGF-ß had extremely up-regulated expressions in the gills at day 8 PI after both high- and low-dose C. sclerosus infections, but its significantly promoted expression in the skin was observed only after infection of high-dose G. cichlidarum. Significantly increased expressions of HSP70 and COX-2 in the skin were detected after high-dose G. cichlidarum infections. In comparison to singular infection with either G. cichlidarum or C. sclerosus, concurrent infection resulted in significantly advanced expression of TGF-ß in both skin and gills, and lower expressions at day 8 PI, and similar patterns were observed in the expression of IL-1ß and TNF-α in the gills. G. cichlidarum infection on the body surface significantly down-regulated the expressions of TNF-α, TGF-ß and COX-2 in the gills. In addition, the intensity of G. cichlidarum was significantly positively correlated with that of C. sclerosus (correlation index 0.922, pâ¯=â¯0.000) at day 2 PI under concurrent infection. These results contribute to the understanding of mucosal immunity of fish against monogenean infection, particularly when two monogenean species infect concurrently.
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Ciclídeos/genética , Ciclídeos/imunologia , Doenças dos Peixes/genética , Doenças dos Peixes/imunologia , Platelmintos , Infecções por Trematódeos/genética , Infecções por Trematódeos/imunologia , Animais , Ciclídeos/parasitologia , Coinfecção/genética , Coinfecção/imunologia , Ciclo-Oxigenase 2/genética , Citocinas/genética , Proteínas de Peixes/genética , Expressão Gênica/imunologia , Brânquias/imunologia , Proteínas de Choque Térmico HSP70/genética , Pele/imunologia , Infecções por Trematódeos/veterináriaRESUMO
Acanthobothrium ningdense n. sp. and Acanthobothrium guanghaiense n. sp. are described from the spiral intestine of the whip stingray, Dasyatis akajei (Müller & Henle). Acanthobothrium ningdense n. sp. is reported based on 38 cestode specimens collected at five locations along the Chinese coast, i.e. Taizhou, Zhejiang Province, Ningde and Xiamen, Fujian Province, Taishan, Guangdong Province and Sanya, Hainan Province between 2012 and 2015. Acanthobothrium ningdense n. sp. belongs to the "species category 4" characterised by Ghoshroy & Caira. Among category 4 Acanthobothrium species, A. ningdense n. sp. most closely resembles A. micracantha Yamaguti, 1952 and A. latum Yamaguti, 1952, both from the same host species. Acanthobothrium ningdense n. sp. differs from A. micracantha by lacking a long robust hook handle that connects the bases of medial and lateral hooks, and from A. latum by having much longer axial prongs than abaxial prongs. Acanthobothrium guanghaiense n. sp., only found in Taishan, Guangdong Province in 2014, is a category 2 Acanthobothrium species. Among category 2, A. guanghaiense n. sp. most closely resembles A. semnovesiculum Verma, 1928, but can be differentiated from it by the arrangement of testes (in two staggered columns rather than in two tandem columns), and the shape of abaxial prong (nearly straight instead of with a conspicuous curve in the proximal portion). Acanthobothrium macrocephalum Wang & Yang, 2001 is redescribed based on new specimens collected from D. akajei in Guanghai and Sanya. With this study, the total number of Acanthobothrium species reported from D. akajei is brought to nine. It is possible that some of the species of Acanthobothrium previously reported from D. akajei not encountered in this study may have geographically restricted distributions, as was observed here for A. guanghaiense n. sp..
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Cestoides/classificação , Infecções por Cestoides/veterinária , Doenças dos Peixes/parasitologia , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , Cestoides/anatomia & histologia , Cestoides/crescimento & desenvolvimento , Cestoides/fisiologia , Infecções por Cestoides/parasitologia , China , Especificidade de Hospedeiro , Tamanho do Órgão , Rajidae/parasitologiaRESUMO
In the present paper, the phylogeographies of two monogenean species, Pseudokuhnia minor and Kuhnia scombri, on the same species of host, Scomber japonicus, were studied. Fragments of the mitochondrial cytochrome c oxidase subunit 1 gene were sequenced for 264 individuals of P. minor and 224 individuals of K. scombri collected from 10 localities along the coast of China. Genetic diversity of K. scombri was higher than that of P. minor, which may imply that P. minor has a lower evolution rate and/or is a younger species. The neighbour-joining (NJ) trees of both parasites were comprised of two clades without association to sample sites, which is the signature of remixing populations following past division. Analyses of molecular variance and pairwise fixation index revealed different genetic structures for the populations of these two closely related species along the coast of China: P. minor without significant genetic structure, while K. scombri has some genetic differentiation. Both neutrality tests and mismatch distribution suggested that the populations of these two species of parasites experienced population expansion in the late Pleistocene era due to the glacial-interglacial cycles induced by climatic oscillations.
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Complexo IV da Cadeia de Transporte de Elétrons/genética , Doenças dos Peixes/parasitologia , Perciformes/parasitologia , Platelmintos/classificação , Animais , Evolução Biológica , China/epidemiologia , Complexo IV da Cadeia de Transporte de Elétrons/química , Doenças dos Peixes/epidemiologia , Genes Mitocondriais , Variação Genética , Filogeografia , Platelmintos/enzimologia , Platelmintos/genética , Água do MarRESUMO
The pelagic stingray Pteroplatytrygon violacea is the only pelagic species of the Dasyatidae (Chondrichthyes: Elasmobranchii), which is widely distributed in all tropical, subtropical and temperate oceans. In this study, the complete mitochondrial genome of Pteroplatytrygon violacea was determined. It is 17,665 bp in length and contains 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and 1 control region, with the typical gene order and direction of transcription of vertebrates. The overall nucleotide compositions of the whole mitogenome are 30.8% A, 26.9% C, 28.6% T and 13.7% G. The ND2 and CO1 sequences are highly similar to the corresponding sequences of this species available in NCBI collected from the Atlantic sea.
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Elasmobrânquios/genética , Genoma Mitocondrial/genética , Animais , Composição de Bases/genética , Ordem dos Genes/genética , RNA Ribossômico/genética , RNA de Transferência/genética , Análise de Sequência de DNA/métodosRESUMO
The whole sequence (15,057 bp) of the mitochondrial DNA (mtDNA) of the terrestrial snail Achatina fulica (order Stylommatophora) was determined. The mitogenome, as the typical metazoan mtDNA, contains 13 protein-coding genes (PCG), 2 ribosomal RNA genes (rRNA) and 22 transfer RNA genes (tRNA). The tRNA genes include two trnS without standard secondary structure. Interestingly, among the known mitogenomes of Pulmonata species, we firstly characterized an unassigned lengthy sequence (551 bp) between the cox1 and the trnV which may be the CR for the sake of its AT bases usage bias (65.70%) and potential hairpin structure.