Transmission of infectious bronchitis virus within vaccinated and unvaccinated groups of chickens.
The aim of this study was to determine whether vaccination against infectious bronchitis virus (IBV) reduces virus transmission, i.e. to test whether IBV transmission among vaccinated chickens is significantly reduced compared to that among unvaccinated chickens. In two vaccinated and two unvaccinated groups of SPF chickens, a standard measure for virus transmission, the reproduction ratio (R) was determined. R is defined as the average number of new infections caused by one typical infectious individual during its entire infectious period. A single vaccination by eye-drop with IBV H120 reduced the transmission of the IBV challenge virus among the vaccinated chickens (estimated R = 0.69, s.e. = 0.33) significantly (P < 0.05) compared to the transmission among the unvaccinated chickens (estimated R = 19.95, s.e. = 12.41). The possible implications for further study, including selection or development of vaccines are discussed.
Comparison of ciliary activity and virus recovery from tracheas of chickens and humoral immunity after inoculation with serotypes of avian infectious bronchitis virus.
Cross-protection tests with homologous and heterologous serotypes of infectious bronchitis virus (IBV) were used to compare ciliary activity and virus recovery from tracheas of chickens. Validation of this technique included correlating the neutralization indices of antiserum obtained from some infected birds. Chickens were inoculated intratracheally with either the JMK or Connecticut (Conn) serotype of IBV. Three weeks later, infected and uninfected groups were challenged by the same route with homologous and heterologous virus. The JMK strain provided immunity against homologous challenge and the Conn strain, as indicated by good ciliary activity and lack of challenge virus recovery. The Conn strain provided only homologous protection, as ciliostasis occurred and virus was recovered after challenge with the JMK strain. In each case, antiserum to immunizing virus neutralized only the homologous virus. Controls were uniformly susceptible and lacked neutralizing antibody. A similar experiment with the Ark 99 serotype and a recent isolate (397) of IBV revealed complete cross-protection of the tracheas. Antiserum to each virus neutralized the homologous and heterologous virus in each case in reciprocal tests. The results indicate that these two viruses are closely related. The complete agreement between ciliary activity and virus isolation indicates that ciliary activity is a reliable, objective criterion upon which tracheal immunity can be judged in cross-protection tests.
Nurse responsiveness to cancer patient expressions of emotion.
OBJECTIVE
This theoretically based study examined nurse responses to cancer patient expressions of emotion using a videotaped, simulated cancer patient.


METHODS
This study used an experimental crossover design with a videotaped patient expressing anger, sadness, and neutral emotion to elicit nurse responses. Seventy-four nurses from eight sites participated. Responses were coded using Roter interaction analysis system. Correlations explored relationships between variables that impact communication (age, gender, work experience, trait anxiety, work stress, self-efficacy). Regression models explored the effect of variables on nurse affective responsiveness.


RESULTS
Patient expressions of sadness elicited more affective responses than anger. Expressions of anger or neutral emotion elicited more instrumental behaviors than sadness. Variables such as age, work stress and work experience were significantly correlated. No variables predicted affective responsiveness to patient expressions of anger or sadness.


CONCLUSION
Nurse communication showed significant variation in response to patient emotional expressions. Understanding the relationships between demographic, personality, and work variables, and identification of new variables that influence nurse-patient communication, has implications for interventional studies.


PRACTICE IMPLICATIONS
Over 90% of the participants indicated that the videotape simulation would be a useful method for teaching and practicing communication skills with patients expressing emotions.