Isolation of Ralstonia solanacearum-infecting bacteriophages from tomato fields in Chiang Mai, Thailand, and their experimental use as biocontrol agents.

AIMS: To isolate and characterize novel bacteriophages infecting the phytopathogen, Ralstonia solanacearum, and to evaluate them as resources with potential uses in the biocontrol of bacterial wilt. METHODS AND RESULTS: Fourteen phages infecting R. solanacearum were isolated from soil samples collected in Chiang Mai, Thailand. The phages showed different host ranges when tested against 59 R. solanacearum strains isolated from Thailand and Japan. These phages were characterized as nine podoviruses and five myoviruses based on their morphology. Podovirus J2 in combination with another podovirus (φRSB2) lysed host cells very efficiently in contaminated soil. J2 treatment prevented wilting of tomato plants infected with a highly virulent R. solanacearum strain. CONCLUSIONS: Treatment with J2 effectively reduced the amount of the bacterial wilt pathogen in contaminated soil and prevented bacterial wilt of tomato in pot experiments. Myovirus J6 possessed jumbo phage features, giving a unique opportunity to study its utilization as a biocontrol agent. SIGNIFICANCE AND IMPACT OF THE STUDY: As exemplified by J2, the phages isolated in this study represent valuable resources with potential uses in biocontrol of bacterial wilt. A rare jumbo phage J6 served as a valuable subject to understand and utilize this new group of phages.

The role performance of public health nurses as clinical instructors in Japan.

AIM: To investigate the factors associated with the role performance of public health nurses as clinical instructors in Japan. BACKGROUND: Newly graduated public health nurses in Japan have competencies that are below the minimum requirements of the Ministry of Health, Labour and Welfare because of their limited clinical experience in undergraduate clinical education. Public health nurses play crucial roles in the clinical practicum and their role performance as clinical instructors is a key to successful learning outcomes. METHODS: This study targeted public health nurses in governmental public health centres and those who had gained experience as an undergraduate clinical instructor for nursing students. A self-administered questionnaire was distributed to a national sample of 1467 public health nurses. Data were collected from July 2011 to September 2011. RESULTS: In total, 722 of 1467 questionnaires were completed (nurse age 22-64 years). Of the participants, almost half (49%) strongly disagreed (3%) or disagreed (46%) that they had confidence in their role as a clinical instructor, and preparation programmes for clinical instructors had been attended by just 262 (36.3%). Years of experience as public health nurses, previous attendance of preparation programmes, viewing their role positively, professional identity and professional competency were significantly associated with performance. Logistic regression analysis revealed that nurses with higher role performance scores had higher self-confidence, greater interests in their role and higher professional identity. CONCLUSIONS: The self-confidence and interests of public health nurses in their role as clinical instructors as well as their professional identity were found to be significant predictors of their role performance as clinical instructors. IMPLICATIONS FOR NURSING PRACTICE AND EDUCATION: The factors identified in our investigation can be used to predict effective clinical instructors and to develop preparation programmes to enhance their confidence and interests and potentially increase their role satisfaction.

Adenocarcinoma in the rectum of a capped langur (Presbytis pileata).

A rectal adenocarcinoma in a 22-year-old capped langur histologically resembling those in human cases is reported. An ill-defined diffuse tumor with fibrously firm rectal wall showed diffuse infiltrative growth of signet-ring cancer cells. Immunohistochemistry demonstrated positive staining for CEA, lysozyme, EMA, keratin and B72.3.

Characterization of a human chorionic gonadotropin-producing testicular choriocarcinoma cell line.

A testicular choriocarcinoma cell line designated JHTK-1 was established in vitro from a mixed germ cell tumor xenografted into nude mice, and may prove to be the first human choriocarcinoma cell line of testicular origin in long-term culture. The cells have been kept in culture for three years and produce human chorionic gonadotropin persistently. The chromosome number distribution ranged from tetraploidy to septaploidy, and trypsin G-band karyotyping showed that all the chromosomes were of human origin. Dibutyryl cyclic adenosine monophosphate at a concentration of 1 mM caused more than 15-fold stimulation of human chorionic gonadotropin secretion with morphological alteration in JHTK-1 cells. This suggests that dibutyryl cyclic adenosine monophosphate induces the differentiation of cytotrophoblastic cells into syncytiotrophoblastic cells among JHTK-1 cells. When JHTK-1 cells were heterotransplanted into the subcutis of BALB/c nude mice, large cystic tumors were produced with histological characteristics similar to choriocarcinoma.