Recent converging evidence suggests that the brain may receive stimuli and possibly modulate tumor progression via the vagus nerve. The present study aimed to compare brain metabolism in patients with and without lung cancer and to assess if significant differences exist in regions associated with the vagus nerve. Methods: Eighteen patients with lung malignancy and 19 controls underwent 18 F-FDG PET of the brain. Brain metabolism was compared using statistical parametric mapping. Results: Patients with lung malignancy showed a statistically significantly higher right cerebellar metabolism. Conclusion: This finding may be related to the role of the cerebellum in immune regulation, because of its proximity to the nucleus tractus solitarius innervated by the vagus and its connections with the hypothalamus. This higher metabolism in the right cerebellum may reflect an attempt to reinstate homeostasis in functions such as respiration and immunity pertinent to lung malignancy. Cancer research has shifted from solely focusing on genetic aspects and defining the intracellular etiology of tumorigenesis to also assessing interactions between tumors and their microenvironment (1). Furthermore, there is increasing interest in assessing the potential presence of bidirectional links between peripheral malignant tumors and the brain, in the form of tumor-to-brain communication and modulation (2).The inflammatory microenvironment plays a crucial role early during tumorigenesis (3,4) and later for angiogenesis and tumor invasion (5). The brain receives signals from peripheral inflammatory processes by several routes, including the vagus (6), through interleukin-1 receptors on its paraganglia. There are conflicting reports on the rate of cancer-related death in vagotomized ulcer patients (7,8). However, chemical and surgical vagotomy prevents tumorassociated anorexia in mice (9) and enhances the metastasizing rate of peripheral malignant tumors (10). In view of these studies, it has been hypothesized that the vagus (and potentially other neural routes) may provide signals about the presence of malignancy-related inflammation to the brain with possible subsequent modulation of tumorigenesis (2,11).The present study aimed to examine brain metabolism in patients with lung malignancy, addressing most of the limitations of prior studies (12-15). Most patients included in the study were evaluated because of pulmonary nodules detected on CT. Both patients and physicians were unaware of the final diagnosis with respect to the presence of active malignancy at the time of imaging, which was performed before any treatment. MATERIALS AND METHODS Patients and Control SubjectsEighteen patients with lung malignancy and 19 controls were included. The malignancy group consisted only of newly diagnosed, histologically proven cases of cancer and included 16 patients with non-small cell lung cancer ( The control group comprised a subgroup of 8 patients with lymphoma in remission for at least 4 y (the LymC group), including Hodgkin lymphoma (n 5 2, s...

Intravascular catheter-related infection and associated bacteraemia constitute a serious and increasing problem among nosocomial infections. As a part of an ongoing survey of positive blood cultures, all catheter-related bloodstream infections (CR-BSI) were reviewed in the authors' Medical Center in 1996, in order to evaluate the magnitude and seriousness of this problem. The largest group (28%) of hospital-acquired bacteraemia by 1 source of infection during 1996 was CR-BSI, identified in 110 patients with 126 episodes. The vascular line was central in 83 (66%), peripheral in 24 (19%), tunnelled in 18 (14%) and arterial in 1 (1%). Among the 83 central CR-BSI no sign of local inflammation was detected in 65%. Gram-positive and gram-negative bacteria shared equal parts among the 145 blood isolates; Staphylococcus aureus was the most common species (43/145, 30%) followed by Klebsiella pneumoniae (15/145, 10%); 11 (8%) isolates were Candida species. Fungal isolates were more common among tunnelled catheter infections than among others (6/18, 33% vs. 5/108, 5%, p < 0.001). Crude mortality was 35% (38/110), while attributable mortality was 14% (15/110), mostly associated with central line infection. Catheter-associated bacteraemias cause significant morbidity and mortality, and have become the most common source of hospital-acquired bacteraemia. There is a need to implement more effective infection-control measures and more advanced technologies in an effort to reduce this unacceptably high incidence.