From Emerging Microbes & Infections, 9 April 2014.
The saga of XMRV: a virus that infects human cells but is not a human virus
Maribel Arias and Hung Fan(*)
– Cancer Research Institute and Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3905, USA
* Correspondence: H Fan, E-mail: hyfan@uci.edu
Abstract
Xenotropic murine leukemia virus-related virus (XMRV) was discovered in 2006 in a search for a viral etiology of human prostate cancer (PC). Substantial interest in XMRV as a potentially new pathogenic human retrovirus was driven by reports that XMRV could be detected in a significant percentage of PC samples, and also in tissues from patients with chronic fatigue syndrome (CFS).
After considerable controversy, etiologic links between XMRV and these two diseases were disproven. XMRV was determined to have arisen during passage of a human PC tumor in immunocompromised nude mice, by activation and recombination between two endogenous murine leukemia viruses from cells of the mouse. The resulting XMRV had a xentropic host range, which allowed it replicate in the human tumor cells in the xenograft.
This review describes the discovery of XMRV, and the molecular and virological events leading to its formation, XMRV infection in animal models and biological effects on infected cells. Lessons from XMRV for other searches of viral etiologies of cancer are discussed, as well as cautions for researchers working on human tumors or cell lines that have been passed through nude mice, includingpotential biohazards associated with XMRV or other similar xenotropic murine leukemia viruses (MLVs).
http://www.ncbi.nlm.nih.gov/pubmed/24736946
From Heart Vessels, 16 April 2014 [Epub ahead of print]
Cardiac dysfunction and orthostatic intolerance in patients with myalgic encephalomyelitis and a small left ventricle.
Miwa K.
Department of Internal Medicine, Miwa Naika Clinic, 1-4-3 Shintomicho, Toyama, 930-0002, Japan, info@miwa-naika.com.
Abstract
The etiology of chronic fatigue syndrome (CFS) is unknown. Myalgic encephalomyelitis (ME) has been recently postulated to be the cause of
CFS.
Orthostatic intolerance (OI) has been known as an important symptom in predicting quality of life in CFS patients. Cardiac function may be impaired in patients with ME. The presence or absence of OI was determined both symptomatically and by using a 10-min stand-up test in 40 ME patients.
Left ventricular (LV) dimensions and function were determined echocardiographically in the ME patients compared to 40 control subjects. OI was noted in 35 (97 %) of the 36 ME patients who could stand up quickly.
The mean values for the cardiothoracic ratio, systemic systolic and diastolic pressures, LV end-diastolic diameter (EDD), LV end-systolic diameter, stroke volume index, cardiac index and LV mass index were all significantly smaller in the ME group than in the controls.
Both a small LVEDD (<40 mm, 45 vs. 3 %) and a low cardiac index (<2 l/min/mm2, 53 vs. 8 %) were significantly more common in the ME group than in the controls. Both heart rate and LV ejection fraction were similar between the groups.In conclusion, a small LV size with a low cardiac output was common in ME patients, in whom OI was extremely common. Cardiac dysfunction with a small heart appears to be related to the symptoms of ME.
From International Journal of Clinical and Health Psychology, Epublished on 12 April 2014.
Symptoms of Meares-Irlen/Visual Stress Syndrome in subjects diagnosed with Chronic Fatigue Syndrome
Stephen J. Loew(a), Nigel V. Marsh(b), Kenneth Watson(a)
a) University of New England, Australia
b) Sunway University, Malaysia
Abstract
Several diagnostic symptoms of the visual-processing deficit Meares-Irlen/Visual Stress Syndrome are remarkably similar to symptom manifestations reported by individuals with chronic fatigue syndrome (CFS).
We surveyed the specific incidences of nine widely-recognised symptoms of visual stress (VS) in a group of subjects (n = 20) previously diagnosed with CFS.
The presence of each symptom of VS in the CFS group was compared to its respective presence in both an age and sex matched healthy comparison group (n = 46), and an age and sex matched group comprised of individuals (n = 14) diagnosed with VS.
Results showed the frequencies of all nine VS symptoms in the CFS-diagnosed group to be significantly higher (p = .032 – p < .0005) than in the comparison group, with only two symptoms being statistically less frequent in the CFS group than in the VS-diagnosed group.The average number of VS symptoms reported by the CFS group was also significantly higher than the comparison group, yet not significantly different from the VS group. Thus, the occurrence of VS symptoms in subjects diagnosed with CFS appears to be far greater than previously reported, which in turn may indicate the interplay of some yet to be identified underlying factor(s) common to both conditions.