Assessing the exposure-response relationship of sleep disturbance and vibration in field and laboratory settings

Exposure to nocturnal freight train vibrations may impact sleep, but exposure-response relationships are lacking. The European project CargoVibes evaluated sleep disturbance both in the field and in the laboratory and provides unique data, as measures of response and exposure metrics are comparable. This paper therefore provides data on exposure-response relationships of vibration and sleep disturbance and compares the relationships evaluated in the laboratory and the field. Two field studies (one in Poland and one in the Netherlands) with 233 valid respondents in total, and three laboratory studies in Sweden with a total of 59 subjects over 350 person-nights were performed. The odds ratios (OR) of sleep disturbance were analyzed in relation to nighttime vibration exposure by ordinal logit regression, adjusting for moderating factors common for the studies. Outcome specific fractions were calculated for eleven sleep outcomes and supported comparability between the field and laboratory settings. Vibration exposure was significantly associated with sleep disturbance, OR = 3.51 (95% confidence interval 2.6-4.73) denoting a three and a half times increase in the odds of sleep disturbance with one unit increased 8 h nighttime log10 Root Mean Square vibration. The results suggest no significant difference between field and laboratory settings OR = 1.37 (0.59-3.19). However, odds of sleep disturbance were higher in the Netherlands as compared to Sweden, indicating unexplained differences between study populations or countries, possibly related to cultural and contextual differences and uncertainties in exposure assessments. Future studies should be carefully designed to record explanatory factors in the field and enhance ecological validity in the laboratory. Nevertheless, the presented combined data set provides a first set of exposure response relationships for vibration-induced sleep disturbance, which are useful when considering public health outcomes among exposed populations.

DHNet: a model for international research collaboration

Internet technology has changed the way information is accessed, shared, and stored. This technology has supported the growth of scientific networks based on the need for improved communications and a team approach to problem solving. Scientists throughout the world are now able to come together in "virtual laboratories" or "collaboratories" to conduct research, analyze data, and discuss findings in a more timely and cost-efficient manner. The DHNet is based on a collaboratory model. It is a Web-based Internet resource designed to encourage research collaboration among dental hygiene professionals without regard to geographic location. The DHNet creates an electronic infrastructure that facilitates the linking, relating, and clustering of concepts that are critical to advancing a body of knowledge. It also creates a new standard for placing information on the Internet, which currently lacks conventions and structures for knowledge management. Designed to be maintained by its users with minimal staff support, the DHNet provides a mechanism for electronic publication of clinical observations, research, research in progress, and other document/media types. DHChat, the discussion forum component, provides an electronic communications tool for discussing topics of interest, research questions, and ways in which researchers would like to work together. Depending on the nature of the investigation, multi-site studies can be conducted or researchers can be responsible for different aspects of the same study. Video conferencing from desktop computers now permits synchronous discussion, enabling participants to see each other and work on the same document. The purposes of this article are to discuss the design of the DHNet as a model for supporting international research collaboration, and to discuss issues related to the use of electronic technology.

[Cured of testicular cancer; does life just go on?]

From 1976 through 1979 we have treated 91 patients with disseminated non-seminomatous testicular cancer with induction chemotherapy comprising cisplatin, vinblastine and bleomycin. After 4 induction cycles complete responders went on to receive maintenance therapy with cisplatin and vinblastine for a median of one year. Fifty-seven patients (63%) are at present alive and free of disease. Seven to ten years after the start of treatment we have investigated their physical, mental and social situation by means of a questionnaire and by collection of data from the charts. It appeared that 90% of the respondents were fully employed. However, over half of the men reported symptoms of polyneuropathy and 40% experienced sexual function disturbances. Part of these problems were due to the maintenance chemotherapy, which has been abandoned in our country since 1982.

Ten-year survival and late sequelae in testicular cancer patients treated with cisplatin, vinblastine, and bleomycin

This 10-year follow-up study of 91 patients with disseminated testicular nonseminomatous cancer, treated with cisplatin, vinblastine, and bleomycin (PVB) induction chemotherapy and vinblastine plus bleomycin maintenance chemotherapy for a planned period of 2 years, shows a 63% cure rate. The predominant long-term sequelae are neurological and sexual dysfunction in 68% and 40% of patients, respectively. Two patients died of myocardial infarction. Sixteen percent of patients developed hypertension, 23% Raynaud's phenomenon, and 25% ototoxicity. Despite the long-term side effects, 90% of the patients who responded to a questionnaire are fully employed. This study shows that the maintenance chemotherapy has contributed to the incidence and/or degree of neurotoxicity, hypertension, and renal function disturbance.