Tumour brain: pre‐treatment cognitive and affective disorders caused by peripheral cancers

People that develop extracranial cancers often display co-morbid neurological disorders, such as anxiety, depression and cognitive impairment, even before commencement of chemotherapy. This suggests bidirectional crosstalk between non-CNS tumours and the brain, which can regulate peripheral tumour growth. However, the reciprocal neurological effects of tumour progression on brain homeostasis are not well understood. Here, we review brain regions involved in regulating peripheral tumour development and how they, in turn, are adversely affected by advancing tumour burden. Tumour-induced activation of the immune system, blood–brain barrier breakdown and chronic neuroinflammation can lead to circadian rhythm dysfunction, sleep disturbances, aberrant glucocorticoid production, decreased hippocampal neurogenesis and dysregulation of neural network activity, resulting in depression and memory impairments. Given that cancer-related cognitive impairment diminishes patient quality of life, reduces adherence to chemotherapy and worsens cancer prognosis, it is essential that more research is focused at understanding how peripheral tumours affect brain homeostasis

Genetic relatedness of Legionella longbeachae isolates from human and environmental sources in Australia.

The genetic relatedness of Legionella longbeachae isolated in Australia since 1987 was investigated by restriction fragment length polymorphism (RFLP) analysis and allozyme electrophoresis. Three radiolabeled probes were used in Southern hybridizations for the RFLP studies. They were Escherichia coli 16S and 23S rRNA and cloned fragments of L. longbeachae selected empirically from genomal banks in lambda and a cosmid. The legionellae included in the study comprised 11 Legionella longbeachae serogroup 1 organisms isolated from humans, 28 L. longbeachae serogroup 1 isolates from environmental sources, and 3 L. longbeachae serogroup 2 environmental isolates. These were compared with the American Type Culture Collection reference strains of both serogroups and some other related Legionella species. Results of allozyme and RFLP analysis showed that all the isolates from humans and all but three of the environmental L. longbeachae serogroup 1 isolates were closely related. They were also closely related to L. longbeachae serogroup 1 ATCC 33462. There was wider variation among the three L. longbeachae serogroup 2 environmental isolates. One of these was closely related to L. longbeachae serogroup 2 ATCC 33484. RFLP studies with the rRNA probe provided the most discrimination among isolates but did not distinguish between the two serogroups