TGI Friday! Our weekly round-up of recently published research abstracts | 31 January 2014

January 31, 2014

From the Journal of Translational Medicine,23 January 2014 (full text available).

Decreased oxygen extraction during cardiopulmonary exercise test in patients with chronic fatigue syndrome

Ruud CW Vermeulen*
* Corresponding author Email:
Ineke WG Vermeulen van Eck Email:
CFS/ME Medical Centre Amsterdam, Waalstraat 25-31, Amsterdam 1078BR, Netherlands

Abstract (provisional)


The insufficient metabolic adaptation to exercise in Chronic Fatigue Syndrome (CFS) is still being debated and poorly understood.


We analysed the cardiopulmonary exercise tests of CFS patients, idiopathic chronic fatigue (CFI) patients and healthy visitors. Continuous non-invasive measurement of the cardiac output by Nexfin ? (BMEYE B.V. Amsterdam, the Netherlands) was added to the cardiopulmonary exercise tests. The peak oxygen extraction by muscle cells and the increase of cardiac output relative to the increase of oxygen uptake (?Q?/?V?O 2 ) were measured, calculated from the cardiac output and the oxygen uptake during incremental exercise.


The peak oxygen extraction by muscle cells was 10.83 ? 2.80 ml/100ml in 178 CFS women, 11.62 ? 2.90 ml/100 ml in 172 CFI, and 13.45 ? 2.72 ml/100 ml in 11 healthy women (ANOVA: P =0.001), 13.66 ? 3.31 ml/100 ml in 25 CFS men, 14.63 ? 4.38 ml/100 ml in 51 CFI, and 19.52 ? 6.53 ml/100 ml in 7 healthy men (ANOVA: P =0.008). The ?Q?/?V?O 2 was > 6 L/L (normal ?Q?/?V?O 2 ? 5 L/L) in 70% of the patients and in 22% of the healthy group.


Low oxygen uptake by muscle cells causes exercise intolerance in a majority of CFS patients, indicating insufficient metabolic adaptation to incremental exercise. The high increase of the cardiac output relative to the increase of oxygen uptake argues against deconditioning as a cause for physical impairment in these patients.

From Reviews in Medical Virology, 24 January 2014 (e-published ahead of print)

Neurological aspects of human parvovirus B19 infection: a systematic review.

Barah F, Whiteside S, Batista S, Morris J.
Center for Neuroscience and Cell Biology, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.


Parvovirus B19 has been linked with various clinical syndromes including neurological manifestations. However, its role in the latter remains not completely understood.

Although the last 10 years witnessed a surge of case reports on B19-associated neurological aspects, the literature data remains scattered and heterogeneous, and epidemiological information on the incidence of B19-associated neurological aspects cannot be accurately extrapolated. The aim of this review is to identify the characteristics of cases of B19-associated neurological manifestations.

A computerized systematic review of existing literature concerning cases of B19-related neurological aspects revealed 89 articles describing 129 patients; 79 (61.2%) were associated with CNS manifestations, 41 (31.8%) were associated with peripheral nervous system manifestations, and 9 (7.0%) were linked with myalgic encephalomyelitis. The majority of the cases (50/129) had encephalitis.

Clinical characteristic features of these cases were analyzed, and possible pathological mechanisms were also described.

In conclusion, B19 should be included in differential diagnosis of encephalitic syndromes of unknown etiology in all age groups. Diagnosis should rely on investigation of anti-B19 IgM antibodies and detection of B19 DNA in serum or CSF. Treatment of severe cases might benefit from a combined regime of intravenous immunoglobulins and steroids.

To confirm these outcomes, goal-targeted studies are recommended to exactly identify epidemiological scenarios and explore potential pathogenic mechanisms of these complications. Performing retrospective and prospective and multicenter studies concerning B19 and neurological aspects in general, and B19 and encephalitic syndromes in particular, are required.

From International Journal of Machine Learning and Computing, April 2014. (Full text available).

Identifying Defining Aspects of Chronic Fatigue Syndrome via Unsupervised Machine Learning and Feature Selection

Samuel P. Watson, Amy S. Ruskin, Valerie Simonis, Leonard A. Jason, Madison Sunnquist, and Jacob D. Furst


In this work we propose an unsupervised machine learning method of predicting chronic fatigue syndrome (CFS) based on the k-means algorithm using self-reported questionnaire responses. We first suggest a method of determining the presence of a symptom based on its frequency and severity using an unsupervised dynamic thresholding approach.

This threshold is used to diagnose subjects with 54 symptoms related to CFS. Based on these diagnoses, k-means is used to predict the presence of CFS. We find that k-means does not have significantly worse predictive diagnostic accuracy than commonly used CFS case definitions.

After applying supervised feature selection, k-means achieves significantly better diagnostic accuracy than any of the case definitions examined. We use these results to suggest the basis for an empirically founded CFS case definition.

From Medical Science Monitor, 14 June 2014.

Multivitamin mineral supplementation in patients with chronic fatigue syndrome.

Maric D(1), Brkic S(1), Tomic S(1), Novakov Mikic A(2), Cebovic T(3), Turkulov V(1).
1) Clinic for Infectious Diseases, Clinical Center Vojvodina, Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia.
2) Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia.
3) Biochemistry Department, Clinical Center Vojvodina, Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia.



Chronic fatigue syndrome (CFS) is characterized by medically unexplained persistent or reoccurring fatigue lasting at least 6 months. CFS has a multifactorial pathogenesis in which oxidative stress (OS) plays a prominent role. Treatment is with a vitamin and mineral supplement, but this therapeutic option so far has not been properly researched.


This prospective study included 38 women of reproductive age consecutively diagnosed by CDC definition of CFS and treated with a multivitamin mineral supplement. Before and after the 2-month supplementation, SOD activity was determined and patients self-assessed their improvement in 2 questionnaires: the Fibro Fatigue Scale (FFS) and the Quality of Life Scale (SF36).


There was a significant improvement in SOD activity levels; and significant decreases in fatigue (p=0.0009), sleep disorders (p=0.008), autonomic nervous system symptoms (p=0.018), frequency and intensity of headaches (p=0.0001), and subjective feeling of infection (p=0.0002). No positive effect on quality of life was found.


Treatment with a vitamin and mineral supplement could be a safe and easy way to improve symptoms and quality of life in patients with CFS.

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