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1.
J Clin Psychol ; 74(1): 109-122, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28759111

RESUMEN

OBJECTIVE: Although meditation practice is an important component of many mindfulness-based interventions (MBIs), empirical findings of its effects on psychological functioning are mixed and the mechanisms for the effects remain unclear. Responding with mindfulness (i.e., returning one's attention back to a nonjudgmental, present-oriented awareness) is a fundamental skill practiced in meditations. With repeated meditation practice, this skill is thought to become internalized and be applied to one's daily life. We thus hypothesized that the extent to which individuals responded to daily events with mindfulness would mediate the effects of meditation practice (instance, duration, and adherence to instructions) on psychological well-being. METHOD: Using a daily diary methodology, we tracked the meditation practice, use of mindful responding during the day, and psychological outcomes (perceived stress, negative and positive affect) of 117 mindfulness-based stress reduction program participants. RESULTS: We found that on days when participants meditated, they responded with greater mindfulness to daily events, which accounted for the beneficial effects of meditating on psychological outcomes. Furthermore, findings suggest that on meditation days, longer and more closely adhered meditation practices were independently associated with increases in mindful responding, which in turn were associated with better psychological outcomes. CONCLUSION: These results suggest that regular, longer, and more closely adhered meditation practice is an important component of MBIs, in part because it leads to responding more mindfully in daily life, which promotes well-being.


Asunto(s)
Afecto/fisiología , Meditación/métodos , Atención Plena/métodos , Evaluación de Procesos y Resultados en Atención de Salud , Cooperación del Paciente/psicología , Estrés Psicológico/terapia , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad
2.
Am J Infect Control ; 51(1): 48-55, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-35231566

RESUMEN

BACKGROUND: In the United States and the United Kingdom, the roles of nurses in antimicrobial stewardship (AS) have been described in guidelines. However, in Japan, no previous studies have clarified nurses' recognition of the role of AS. Moreover, how the AS roles were implemented among nurses in Japan has not been fully clarified. The objectives of this study were to determine the perceptions of infection control nurses (ICNs) in Japan regarding the AS role of nurses and the extent of nurses' practice. METHODS: A questionnaire survey of ICNs was conducted. RESULTS: Four hundred responses (response rate, 30.8%) were analyzed. Some of the items that have already gained consensus as the AS role of nurses were not recognized as the AS role of nurses by ICNs or had low implementation rates in Japan. Meanwhile, both recognition and implementation rates were high for the 5 types of care proposed. DISCUSSION: The reason the ICNs agreed that these 5 types of care are AS roles for nurses is that they know that such care can prevent infection and thereby obviate the need for antimicrobial administration. However, whether nurses themselves understand that these are roles for nurses in AS is unclear. To promote AS in Japan, communicating the fact that nurses already contribute to AS, strengthening nurse education, and improving staffing are desirable.


Asunto(s)
Programas de Optimización del Uso de los Antimicrobianos , Enfermeras y Enfermeros , Humanos , Rol de la Enfermera , Japón , Encuestas y Cuestionarios , Antibacterianos/uso terapéutico
3.
J Appl Psychol ; 108(4): 553-570, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35901406

RESUMEN

Employees often have a great deal of work to accomplish within stringent deadlines. Therefore, employees may engage in shortcut behaviors, which involve eschewing standard procedures during goal pursuit to save time. However, shortcuts can lead to negative consequences such as poor-quality work, accidents, and even large-scale disasters. Despite these implications, few studies have investigated the antecedents of shortcut behaviors. In this research, we propose that employees engage in shortcut behaviors to regulate their velocity (i.e., rate of progress). Specifically, we predict that when individuals experience slower-than-referent velocity, they will (a) believe that the goal is unlikely to be met via standard procedures and (b) experience feelings of frustration. In turn, we expect these psychological states to be related to the perceived utility of shortcuts, especially when shortcuts are perceived as viable means to achieve the goal. Finally, we predict that the perceived utility of shortcuts will be positively related to actual shortcut behaviors. We tested these predictions using a laboratory experiment in which we manipulated velocity and unobtrusively observed shortcuts (Study 1, N = 147), as well as a daily diary study in which employees reported their velocity and shortcut behaviors over 5 consecutive workdays (Study 2, N = 395). Both studies provided support for our predictions. In sum, this research provides evidence to suggest that the experience of slow progress can lead to shortcuts not only by casting doubt on employees' perceived likelihood of meeting the goal but also by producing feelings of frustration. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Asunto(s)
Objetivos , Motivación , Humanos , Emociones , Frustación
4.
J Leadersh Organ Stud ; 29(1): 33-72, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35966893

RESUMEN

Although a litany of theoretical accounts exists to explain why mistreated employees engage in counterproductive work behaviors (CWBs), little is known about whether these mechanisms are complementary or mutually exclusive, or the effect of context on their explanatory strength. To address these gaps, this meta-analytic investigation tests four theoretically-derived mechanisms simultaneously to explain the robust relationship between leader mistreatment and employee CWB: (1) a social exchange perspective, which argues that mistreated employees engage in negative reciprocal behaviors to counterbalance experienced mistreatment; (2) a justice perspective, whereby mistreated employees experience moral outrage and engage in retributive behaviors against the organization and its members; (3) a stressor-emotion perspective, which suggests that mistreated employees engage in CWBs to cope with their negative affect; and (4) a self-regulatory perspective, which proposes that mistreated employees are simply unable to inhibit undesirable behaviors. Moreover, we also examine whether the above model holds across cultures that vary on power distance. Our meta-analytic structural equation model demonstrated that all but the justice mechanism significantly mediated the relationship between leader mistreatment and employee CWBs, with negative affect emerging as the strongest explanatory mechanism in both high and low power distance cultures. Given these surprising results, as the stressor-emotion perspective is less frequently invoked in the literature, this paper highlights not only the importance of investigating multiple mechanisms together when examining the leader mistreatment-employee CWB relationship, but also the need to develop more nuanced theorizing about these mechanisms, particularly for negative affect.

5.
Zoolog Sci ; 28(12): 922-9, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22132790

RESUMEN

We describe a new species of dicroglossid frog of the Fejervarya limnocharis complex from western Honshu, Japan Mainland. The new species, Fejervarya kawamurai, is genetically closer to F. sakishimensis than to F. limnocharis. It differs from F. sakishimensis by smaller tympanum, head, forelimb, hindlimb, foot, and tibia lengths, all relative to snout-vent length, and from F. multistriata by relatively shorter forelimb, hindlimb, foot, and tibia. From F. limnocharis and F. iskandari, it is differentiated by relatively smaller forelimb, hindlimb, foot, and tibia lengths. Taxonomic problems of Fejervarya populations occurring in Central Ryukyus, continental China, and Taiwan are discussed.


Asunto(s)
Anuros/anatomía & histología , Anuros/clasificación , Animales , Demografía , Femenino , Japón , Masculino , Caracteres Sexuales , Especificidad de la Especie
6.
Zoolog Sci ; 27(3): 222-33, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20192690

RESUMEN

To elucidate genetic divergence and evolutionary relationship in Fejervarya cancrivora from Indonesia and other Asian countries, allozyme and molecular analyses were carried out using 131 frogs collected from 24 populations in Indonesia, Thailand, Bangladesh, Malaysia, and the Philippines. In the allozymic survey, seventeen enzymatic loci were examined for 92 frogs from eight representative localities. The results showed that F. cancrivora is subdivided into two main groups, the mangrove type and the large- plus Pelabuhan ratu types. The average Nel's genetic distance between the two groups was 0.535. Molecular phylogenetic trees based on nucleotide sequences of the 16S rRNA and Cyt b genes and constructed with the ML, MP, NJ, and BI methods also showed that the individuals of F. cancrivora analyzed comprised two clades, the mangrove type and the large plus Pelabuhan ratu / Sulawesi types, the latter further split into two subclades, the large type and the Pelabuhan ratu / Sulawesi type. The geographical distribution of individuals of the three F. cancrivora types was examined. Ten Individuals from Bangladesh, Thailand, and the Philippines represented the mangrove type; 34 Individuals from Malaysia and Indonesia represented the large type; and 11 individuals from Indonesia represented the Pelabuhan ratu / Sulawesi type. Average sequence divergences among the three types were 5.78-10.22% for the 16S and 12.88-16.38% for Cyt b. Our results suggest that each of the three types can be regarded as a distinct species.


Asunto(s)
Anuros/genética , Anuros/fisiología , ADN Mitocondrial/genética , Animales , Asia , Secuencia de Bases , Evolución Biológica , Demografía , Variación Genética , Isoenzimas/genética , Filogenia
7.
Zoolog Sci ; 25(11): 1084-105, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19267620

RESUMEN

In the present study, morphological examinations, crossing experiments and molecular analyses were performed to elucidate the degree of genetic divergence and phylogenetic relationships within the genus Fejervarya from Bangladesh and other Asian countries. Morphological characteristics revealed that Fejervarya species from Bangladesh were divided into four distinct groups: large, medium, small, and mangrove types. Crossing experiments indicated the involvement of three reproductive isolating mechanisms: gametic isolation between the large type and mangrove type, hybrid inviability between the large type and two other types, and hybrid sterility between the medium and small types. Experimental results also indicated that these four types of frogs merit the status of individual species of Fejervarya . Molecular analyses based on mtDNA gene sequences showed that the Bangladesh Fejervarya species were largely divided into three groups: the mangrove type, large type, and others, with the last further subdivided into the medium and small types. Comparison with other Asian Fejervarya species revealed that the Bangladesh mangrove type (which resembled F. cancrivora in morphology) was closely related to F. cancrivora from India, Thailand, and the Philippines; the large type belonged to the F. iskandari group and closely resembled F. orissaensis ; the small type was included in the South Asian or Indian group, and was closest to F. syhadrensis from India and Sri Lanka, whereas the medium type was most closely related to F. limnocharis from Myanmar among all described species of this genus.


Asunto(s)
Anuros/genética , Anuros/fisiología , Cruzamientos Genéticos , Demografía , Variación Genética , Animales , Bangladesh , Femenino , Masculino , Filogenia , Reproducción/genética , Reproducción/fisiología
8.
Zoolog Sci ; 24(12): 1197-212, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18271636

RESUMEN

In order to elucidate the taxonomic status of the Fejervarya limnocharis complex relative to Malaysia and Japan populations, morphological observations and molecular phylogenetic analysis were carried out using three populations from Indonesia (type locality), Malaysia, and Japan. In addition, we conducted histological and spermatogenic observations using hybrids among these populations. Principal component and cluster analyses demonstrated that these populations could be clearly separated from one another. Abnormal testes were found in the hybrids between the Japan and Indonesia populations and between the Japan and Malaysia populations, but testes of the controls and hybrids between the Malaysia and Indonesia populations were quite normal. The mean number of univalents per cell was 5.42, 4.58, and 0.20 in hybrids between the Indonesia and Japan populations, Malaysia and Japan populations, and Indonesia and Malaysia populations, respectively. Sequence divergences in 16S rRNA and Cyt b genes were 0-0.4% (xbar=0.2%) and 0.3-1.5% (xbar=1.0%), respectively, between the Malaysia and Indonesia populations, and 2.4-2.6% (xbar=2.5%) and 11.0-12.0% (xbar=11.5%) between the Japan population and F. limnocharis complex, including the Malaysia and Indonesia populations and F. multistriata from China. This study indicated that the Malaysia population and F. multistriata from China should be designated as a subspecies of topotypic F. limnocharis, and that the Japan population should be regarded as a distinct species.


Asunto(s)
Cruzamientos Genéticos , Citocromos b/genética , Evolución Molecular , Filogenia , Ranidae , Animales , Análisis por Conglomerados , Femenino , Indonesia , Japón , Malasia , Masculino , Análisis de Componente Principal , ARN Ribosómico 16S/análisis , Ranidae/clasificación , Ranidae/genética , Ranidae/fisiología
9.
Zoolog Sci ; 24(4): 360-75, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17867834

RESUMEN

In order to elucidate the genetic relationships and reproductive-isolation mechanisms among the Fejervarya limnocharis complex from Indonesia and other Asian countries, allozyme analyses and crossing experiments were carried out using 208 individuals from 21 localities in eight Asian countries. The allozyme analyses revealed that 17 enzymes examined were controlled by genes at 27 loci, and that 7.9 phenotypes were produced by 5.2 alleles on average. The two species recognized in F. limnocharis sensu lato from Southeast Asia (i.e., F. limnocharis sensu stricto and F. iskandari) were found to occur sympatrically at three localities (Bogor, Cianjur and Malingping), all on Java, Indonesia. Fejervaya iskandari was dominant at each of these localities and showed substantial geographic genetic variation. Laboratory-produced hybrids between F. limnocharis and F. iskandari from Java became underdeveloped and died at the tadpole stage, suggesting that these species are completely isolated by hybrid inviability. Hybrids between topotypic F. limnocharis and the Malaysian and Japanese conspecific populations developed normally to metamorphosis. Likewise, hybrids between topotypic F. iskandari and the Thailand and Bangladesh conspecific populations also showed normal viability throughout larval development. The present allozyme analyses and crossing experiments strongly suggested the presence of two distinct forms, the large type and the small type, in the F. limnocharis complex from Asia, and further subdivision of the large type into the F. limnocharis assemblage and the F. iskandari assemblage. The small type was found in samples from India, Thailand, Bangladesh and Sri Lanka, and included at least three different species. The sample from Pilok, Thailand, was considered to represent an undescribed species.


Asunto(s)
Enzimas/genética , Regulación Enzimológica de la Expresión Génica , Variación Genética , Ranidae/genética , Ranidae/fisiología , Alelos , Animales , Asia , Cruzamientos Genéticos , Femenino , Transferencia de Gen Horizontal , Indonesia , Masculino , Ranidae/clasificación , Reproducción , Especificidad de la Especie
10.
Zoolog Sci ; 24(6): 547-62, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17867856

RESUMEN

The rice frog (Fejervarya limnocharis) species complex is widely distributed, from India to Japan, and most prevalently in Southeast Asia. Conspicuous morphological variation has been reported for this species complex throughout its distribution range. In the present study, we used mtDNA gene sequence and allozyme analyses to infer evolutionary affinities within this species complex using eight populations (Sri Lanka; Bangkok and Ranong in Thailand; Taiwan; and Hiroshima, Okinawa, Ishigaki and Iriomote in Japan). We also conducted crossing experiments among four populations from Japan, Thailand, and Sri Lanka in order to find out more about the reproductive isolating mechanisms that might exist among the East, Southeast, and South Asian populations of this species complex. The crossing experiments revealed that the Sri Lanka population is reproductively isolated from the Hiroshima, Bangkok, and Ranong populations by complete hybrid inviability, and that the Bangkok population may be reproductively isolated from the Hiroshima population by partial hybrid inviability. Thus, it is not unreasonable to regard the Sri Lanka population as a species separated from F. limnocharis. The mtDNA and allozyme data showed that the Ranong population is most closely related to the Bangkok population in nuclear genome, but more similar to the Okinawa and Taiwan populations in mtDNA genome. The present, preliminary survey may raise questions about the species status of these particular populations and also about the nature of the biological species concept.


Asunto(s)
ADN Mitocondrial/química , Enzimas/genética , Variación Genética , Ranidae/clasificación , Ranidae/genética , Animales , Secuencia de Bases , Cruzamientos Genéticos , ADN Mitocondrial/genética , Evolución Molecular , Femenino , Regulación Enzimológica de la Expresión Génica , Haplotipos , Hibridación Genética , Japón , Masculino , Filogenia , Reproducción , Alineación de Secuencia/veterinaria , Especificidad de la Especie , Sri Lanka , Taiwán , Tailandia
11.
Infect Control Hosp Epidemiol ; 23(7): 404-6, 2002 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12138982

RESUMEN

We initiated surveillance for surgical-site infections (SSIs) in a Japanese hospital using Centers for Disease Control and Prevention definitions and the approach of the National Nosocomial Infections Surveillance (NNIS) System. Patients were observed following clean and clean-contaminated abdominal operations. SSI rates were higher than those of the NNIS System, but there was a trend toward decreased SSI rates in the latter half of the study period.


Asunto(s)
Abdomen/cirugía , Infección Hospitalaria/prevención & control , Procedimientos Quirúrgicos del Sistema Digestivo/efectos adversos , Control de Infecciones/métodos , Vigilancia de la Población/métodos , Infección de la Herida Quirúrgica/prevención & control , Costos de Hospital , Humanos , Control de Infecciones/economía , Japón
12.
Zoolog Sci ; 20(5): 567-80, 2003 May.
Artículo en Inglés | MEDLINE | ID: mdl-12777828

RESUMEN

Crossing experiments were made among various brown frog species and populations collected from Japan, China, Russia and Taiwan. The main purpose of these experiments was to confirm the existence of reproductive isolating mechanisms among Rana pirica from Japan, R. chensinensis from China and R. chensinensis from Russia, and between these three taxa and the other brown frogs distributed in the Palearctic and Oriental regions. It was found that there was no or a slight gametic isolation among the three taxa. While there was a nearly equal number of male and female offspring in the control groups, the hybrid frogs were all males, and completely sterile upon attaining sexual maturity. Thus, each of the Japanese R. pirica and the Russian R. chensinensis is a valid species, distinct from the Chinese R. chensinensis. The phylogenetic tree based on nucleotide sequence data from the mitochondrial 12S and 16S rRNA genes of the Palearctic and Oriental brown frogs showed that the three taxa are included in a cluster together with the other species with 2n=24 chromosomes. The present crossing experiments and molecular data support the hypothesis that each of them is a separate but closely related species.


Asunto(s)
ARN Ribosómico/genética , Ranidae/clasificación , Ranidae/genética , Reproducción , Animales , China , Cartilla de ADN , Evolución Molecular , Femenino , Variación Genética , Geografía , Japón , Masculino , Filogenia , Reacción en Cadena de la Polimerasa , ARN Ribosómico 16S/genética , Federación de Rusia , Taiwán , Testículo/anatomía & histología
13.
Am J Infect Control ; 42(4): 385-8, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24679565

RESUMEN

BACKGROUND: This historical case-control study examined the effectiveness of an outpatient preoperative care bundle on the incidence of postoperative pneumonia among patients with esophageal cancer. METHODS: We implemented a preoperative care bundle that comprised 7 care procedures that previous studies had suggested to be effective for decreasing postoperative respiratory complications, infections, postoperative hospital stay, and mortality. The care bundle group included patients who underwent surgery after the care bundle was implemented, whereas the control group included those who underwent surgery before its implementation. RESULTS: The incidence of postoperative pneumonia was 3.8% in the care bundle group (1/26) and 22.4% in the control group (48/214). A logistic regression model showed that implementation of the care bundle had a significant effect on prevention of postoperative pneumonia (odds ratio, 0.16; 95% confidence interval: 0.01-0.94) after controlling the following confounding factors: sex, blood urea nitrogen, amount of blood loss, recurrent laryngeal nerve palsy, and preoperative hospital stay. CONCLUSION: Implementation of the procedures of the preoperative care bundle was shown to be effective for preventing postoperative pneumonia in patients with esophageal cancer.


Asunto(s)
Atención Ambulatoria/métodos , Neoplasias Esofágicas/cirugía , Control de Infecciones/métodos , Neumonía/prevención & control , Complicaciones Posoperatorias/prevención & control , Cuidados Preoperatorios/métodos , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Investigación sobre Servicios de Salud , Humanos , Incidencia , Masculino , Persona de Mediana Edad
14.
Am J Infect Control ; 37(7): 580-6, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19535174

RESUMEN

BACKGROUND: The aims of this study were to investigate the risk factors of methicillin-resistant Staphylococcus aureus (MRSA) infection among infants to establish effective infection control measures for neonatal intensive care unit (NICU). METHODS: Data were prospectively collected from 961 infants hospitalized in a teaching hospital in Japan, from July 2002 through December 2005. RESULTS: Among all infants, 28 (2.9%) developed MRSA infections. Multivariate logistic regression analyses demonstrated the risk factors for developing MRSA infections to include a low birth weight (odds ratio [OR], 0.91; 95% confidence interval [CI]: 0.93-0.99), the presence of eye mucous (OR, 6.78; 95% CI: 2.87-16.01), the practice of kangaroo mother care (OR, 3.82; 95% CI: 1.11-13.13), and the MRSA colonization rate (OR, 11.12; 95% CI: 1.32-93.89). CONCLUSION: The risk factors for developing a MRSA infection among infants in NICU were a low birth weight, the presence of eye mucous, the practice of kangaroo mother care, and a high MRSA colonization rate. Therefore, extra attention should be given to infants in high-risk groups demonstrating a low birth weight and the presence of eye mucous and who have undergone kangaroo mother care. As a result, the cohort isolation of infants with MRSA may therefore be an effective strategy to prevent MRSA infections.


Asunto(s)
Infección Hospitalaria/epidemiología , Unidades de Cuidado Intensivo Neonatal/estadística & datos numéricos , Staphylococcus aureus Resistente a Meticilina , Infecciones Estafilocócicas/epidemiología , Peso al Nacer/inmunología , Peso al Nacer/fisiología , Portador Sano/microbiología , Portador Sano/prevención & control , Infección Hospitalaria/microbiología , Infección Hospitalaria/prevención & control , Susceptibilidad a Enfermedades , Femenino , Hospitales de Enseñanza , Humanos , Cuidado del Lactante/métodos , Recién Nacido de Bajo Peso , Recién Nacido , Control de Infecciones , Japón/epidemiología , Modelos Logísticos , Masculino , Análisis Multivariante , Oportunidad Relativa , Estudios Prospectivos , Factores de Riesgo , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/prevención & control
15.
Mol Phylogenet Evol ; 38(1): 250-60, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16266814

RESUMEN

The toads of the Bufo bufo species group are widely distributed in the Eurasian continent and Japanese Archipelago. In this study, we analyzed the mtDNA gene sequences of this species group and estimated the divergence time to clarify the evolutionary relationships and biogeography of toads distributed in the Far East and Europe. The phylogenetic tree indicated that this group produced Bufo bufo in Europe, whereas it produced B. japonicus in the Far East. B. japonicus was divided into three major clades corresponding to a group consisting of B. j. gargarizans in China, B. j. bankorensis in Taiwan, and B. j. miyakonis on Miyako Isl. and eastern and western groups of Japanese B. j. japonicus subspecies group. The eastern and western groups were divided into several subclades which tended to reflect the region-specific geographic distribution of all localities except B. j. japonicus from Hakodate. The estimated branching times of these clades suggest that geological events may have influenced the divergence of the toads distributed in the Far East and Europe.


Asunto(s)
Bufo bufo/clasificación , Bufo bufo/genética , Evolución Molecular , Filogenia , Animales , Secuencia de Bases , ADN Mitocondrial/genética , Europa (Continente) , Asia Oriental , Variación Genética , Datos de Secuencia Molecular
16.
Mol Phylogenet Evol ; 25(2): 293-305, 2002 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12414311

RESUMEN

The rice frog Rana limnocharis is widely distributed in Southeast Asia and the rest of the Asian region extending from India to Japan. In Japan, the Sakishima-island populations of this species were regarded as a distinct species based on morphological and genetic divergences. The main purposes of this study were to confirm the presence of intraspecific reproductively isolating mechanisms in the Sakishima-island populations of R. limnocharis, and to clarify molecular inter- and intraspecific relationships of R. limnocharis and an allied species, Rana cancrivora. The hybridization experiments revealed that there were no reproductively isolating mechanisms between the Sakishima-island populations and other populations of R. limnocharis. The molecular evolutionary relationships were investigated by analyzing nucleotide sequences of the mitochondrial 12S and 16S rRNA genes using 12 populations of R. limnocharis from Japan and Taiwan, and two populations of R. cancrivora from Thailand and the Philippines. The phylogenetic trees constructed by the NJ method showed that the two populations of R. cancrivora were clearly separated from the 12 populations of R. limnocharis, and that the 12 populations of R. limnocharis were broadly divided into three clades; the first comprising eight populations from the main islands of Japan, the second comprising the Sakishima-island populations, and the third comprising the Okinawa-island and Taiwan populations. Interestingly, the Okinawa-island and Taiwan populations of R. limnocharis showed a close relationship that possibly reflected a secondary contact between the two populations. Based on the present crossing experiments and molecular data, it seems reasonable to regard the Sakishima-island populations as a single subspecies of R. limnocharis.


Asunto(s)
Evolución Molecular , ARN Ribosómico 16S/genética , ARN Ribosómico/genética , Ranidae/genética , Animales , Constitución Corporal/genética , Fertilidad/genética , Haplotipos , Hibridación Genética , Mitocondrias/genética , Filogenia , Mutación Puntual
17.
Int J Cancer ; 103(1): 1-4, 2003 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-12455046

RESUMEN

Frequent development of renal cell carcinomas in hybrids between Japanese toads (Bufo japonicus) and imported Chinese toads (Bufo raddei) was first reported by 2 of our authors in 1987. Such renal tumors of toads had never been observed previously in the laboratory. To confirm the observation and to establish a new animal model system, hybrids between female Japanese and male Chinese toads were newly generated from 3 pairs of parents and pathological changes in their kidneys were examined sequentially over 6 years. In hybrids from 2 of the 3 pairs, bilateral polycystic kidney developed at a high frequency from 3 months after fertilization, this being associated with the emergence of atypical, premalignant-appearing cells in proximal tubules. Papillary lesions developed after 12 months and renal cell carcinomas after 48 months. Such pathological changes were never seen in non-hybrid Chinese or Japanese toads. Electron microscopy showed no evidence of any viral participation. This unique toad model may prove useful for investigation of the underlying mechanisms of genetically determined renal cell carcinogenesis.


Asunto(s)
Bufonidae , Carcinoma de Células Renales/veterinaria , Quimera , Neoplasias Renales/veterinaria , Enfermedades Renales Poliquísticas/veterinaria , Animales , Carcinoma de Células Renales/patología , China , Cruzamientos Genéticos , Modelos Animales de Enfermedad , Femenino , Japón , Neoplasias Renales/patología , Lectinas/química , Masculino , Enfermedades Renales Poliquísticas/patología
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