Tag: muscle biopsies

Electron-microscopic investigation of muscle mitochondria in chronic fatigue syndrome

Abstract:

Patients with chronic fatigue syndrome (CFS) suffer from disabling physical and mental fatigue. Abnormalities in mitochondrial function can lead to fatigue and weakness. Ultrastructural mitochondrial abnormalities have been reported to be present in CFS patients.

We obtained percutaneous needle muscle biopsies from 15 CFS patients and 15 age- and sex-matched controls. We investigated previously reported ultrastructural abnormalites in CFS: subsarcolemmal mitochondrial aggregates, intermyofibrillar mitochondrial aggregates, mitochondrial circumference, area, pleomorphism and the presence of compartmentalization of the inner mitochondrial membrane. All of the steps of tissue processing, electron microscopy and data abstracting and analysis were performed in a totally blinded fashion. All of our data were rigorously quantified.

We found no difference in any of these studied parameters between CFS patients and controls. Although there is no ultrastructural mitochondrial abnormality in CFS patients, other lines of evidence suggest the presence of a possible functional mitochondrial abnormality.

 

Source: Plioplys AV, Plioplys S. Electron-microscopic investigation of muscle mitochondria in chronic fatigue syndrome. Neuropsychobiology. 1995;32(4):175-81. http://www.ncbi.nlm.nih.gov/pubmed/8587699

 

Single fibre EMG studies in chronic fatigue syndrome: a reappraisal

Comment on: Single fibre EMG studies in chronic fatigue syndrome: a reappraisal. [J Neurol Neurosurg Psychiatry. 1994]

 

We were interested in the short report from Roberts and Byrne concerning single fibre EMG studies in chronic fatigue syndrome. They concluded that there was no evidence of abnormality at the terminal axon, neuromuscular junction, or muscle membrane in patients with chronic fatigue syndrome-a finding that concurs with our own of essentially normal jitter in 34 of 35 patients with chronic unexplained fatigue. We did detect some evidence of raised fibre density in a small subgroup of patients with pronounced myalgia who also had mild abnormalities on muscle biopsy.

Raised fibre density is usually a result of collateral sprouting after reinnervation, but can also be due to fibre splitting as can occur in some myopathic states. Therefore we believe that fibre density estimation performed in addition to jitter measurement adds considerably to the information obtained from single fibre EMG studies.

You can read the full comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1073160/pdf/jnnpsyc00039-0137a.pdf

 

Source: Connolly S, Fowler CJ. Single fibre EMG studies in chronic fatigue syndrome: a reappraisal. J Neurol Neurosurg Psychiatry. 1994 Sep;57(9):1157. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1073160/

 

Use of dynamic tests of muscle function and histomorphometry of quadriceps muscle biopsies in the investigation of patients with chronic alcohol misuse and chronic fatigue syndrome

Abstract:

Ischaemic lactate/ammonia tests, serum carnosinase and creatine kinase assays and percutaneous needle muscle biopsies were performed on 10 patients with chronic fatigue syndrome (CFS), and 10 with chronic alcohol misuse complaining of muscular symptoms.

Basal serum lactate levels were significantly elevated in the alcohol misusers compared to the CFS patients, but all were within the reference range. Lactate profiles after ischaemic forearm exercise did not differ significantly for the two patient groups.

In one patient previously diagnosed as having CFS, myoadenylate deaminase deficiency was identified on the basis of a flat ammonia response to ischaemia and absent muscle adenosine monophosphate deaminase activity. In addition, two further patients in the CFS group were subsequently shown to have other disorders: one had polymyositis and one had myopathy with mild type II fibre atrophy of unknown cause.

Histomorphometric examination of muscle needle biopsy in the alcohol misusers showed features of chronic alcohol-induced skeletal myopathy in six patients and polymyositis in one patient. Type II fibre atrophy factors were significantly elevated in the alcohol group but were within the reference range in CFS patients.

Dynamic tests of muscle function and muscle histology are valuable tools in excluding alternative pathology in CFS, whereas muscle histomorphometry is of the greatest value in the diagnosis of chronic alcoholic myopathy.

 

Source: Wassif WS, Sherman D, Salisbury JR, Peters TJ. Use of dynamic tests of muscle function and histomorphometry of quadriceps muscle biopsies in the investigation of patients with chronic alcohol misuse and chronic fatigue syndrome. Ann Clin Biochem. 1994 Sep;31 ( Pt 5):462-8. http://www.ncbi.nlm.nih.gov/pubmed/7832572

 

Studies on enterovirus in patients with chronic fatigue syndrome

Abstract:

A large study on 121 patients with the chronic fatigue syndrome (CFS) that examined muscle biopsy samples for enterovirus by means of polymerase chain reaction analysis was carried out. The results were compared with those obtained from 101 muscle biopsy specimens from patients with a variety of other neuromuscular disorders (OND), including neurogenic atrophies, dystrophies, and mitochondrial, metabolic, and endocrine myopathies.

Thirty-two (26.4%) of the biopsy specimens from the group of patients with CFS were positive, compared with 20 (19.8%) from the group of patients with OND, a difference that was not significant.

This finding is in contrast to those of our previous smaller study in which significantly more patients with CFS than control subjects (53% [32 of 60] vs. 15% [6 of 41]) had enterovirus RNA sequences in their muscle. It was concluded that it is unlikely that persistent enterovirus infection plays a pathogenetic role in CFS, although an effect in initiating the disease process cannot be excluded.

 

Source: Gow JW, Behan WM, Simpson K, McGarry F, Keir S, Behan PO. Studies on enterovirus in patients with chronic fatigue syndrome. Clin Infect Dis. 1994 Jan;18 Suppl 1:S126-9. http://www.ncbi.nlm.nih.gov/pubmed/8148439

 

Biochemical and muscle studies in patients with acute onset post-viral fatigue syndrome

Abstract:

AIMS: To investigate in detail various biochemical and pathophysiological indices of muscle pathology in acute onset post-viral fatigue syndrome (PVFS).

METHODS: Twenty three patients with PVFS (of mean duration 4.6 years) were subjected to needle biopsy for histomorphometry and total RNA contents. Plasma analysis included serology and creatine kinase activities. Indices of whole body mass were also measured–namely, whole body potassium content and plasma carnosinase activities.

RESULTS: About 80% of the patients had serology indicative of persistent enteroviral infection as determined by VP1 antigen assay. Only about 10% of that same group of patients had serological indications of current enterovirus infection by IgM assay; a separate subset of 10% showed antibody changes suggestive of reactivation of Epstein-Barr virus. Quantitative morphometric analysis of skeletal muscle fibres indicated that the quadriceps muscle was normal or displayed only minor abnormalities in 22 patients. The Quetelet’s Index (body mass index) and whole-body potassium values (index of lean body mass) were not affected in PVFS. The mean plasma carnosinase and creatinine kinase activities were also generally normal in these patients. The mean muscle RNA composition–mg RNA/mg DNA: was significantly reduced in acute onset PVFS by about 15%. The protein:DNA ratio was not significantly affected.

CONCLUSIONS: Patients with acute onset PVFS, therefore, lose muscle protein synthetic potential, but not muscle bulk. Histopathology is consistent with these observations. These perturbations may contribute to the apparent feature of perceived muscle weakness associated with the persistent viral infection in the muscle themselves.

 

Source: Preedy VR, Smith DG, Salisbury JR, Peters TJ. Biochemical and muscle studies in patients with acute onset post-viral fatigue syndrome. J Clin Pathol. 1993 Aug;46(8):722-6. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC501456/

 

Chronic fatigue: electromyographic and neuropathological evaluation

Abstract:

Single fibre electromyography of extensor digitorum communis muscle (EDC) was performed on 35 patients with chronic fatigue, the majority of whom also had creatine kinase estimation and biopsy of EDC.

The subjects were categorised as having an acute-onset post-viral fatigue syndrome, a non-specific chronic fatigue or possible muscle disease in view of pronounced myalgia.

Of 11 subjects who had myalgia as a significant symptom, abnormalities in fibre density were found in 6, and 5 of these had some non-specific abnormalities on muscle biopsy, with creatine kinase levels being normal in all cases. Fibre density estimation may be a useful way of identifying a subgroup of chronic fatigue sufferers with a possible primary muscle disorder.

 

Source: Connolly S, Smith DG, Doyle D, Fowler CJ. Chronic fatigue: electromyographic and neuropathological evaluation. J Neurol. 1993 Jul;240(7):435-8. http://www.ncbi.nlm.nih.gov/pubmed/8410086

 

Persistence of enterovirus RNA in muscle biopsy samples suggests that some cases of chronic fatigue syndrome result from a previous, inflammatory viral myopathy

Abstract:

Molecular hybridization using an enterovirus group specific probe detected virus RNA in muscle biopsy samples from 25 of 96 cases of inflammatory muscle disease and similarly from 41 of 158 cases of postviral fatigue syndrome (PFS).

Enterovirus RNA was detected in only two of 152 samples of control muscle. The inflammatory myopathy group comprised patients with polymyositis (PM), juvenile dermatomyositis (JDM) or adult dermatomyositis (DM), and all showed the presence of an inflammatory infiltrate and fiber necrosis on histological examination of a muscle biopsy sample.

In contrast, muscle samples from the PFS group were histologically normal except for non-specific changes such as occasional single fiber atrophy. By analogy with enteroviral myocarditis, which can progress to a post-inflammatory disease with persistence of virus in myocardium and disposes to the rapid development of dilated cardiomyopathy, we propose that PFS syndrome may be a sequela of a previous inflammatory viral myopathy.

 

Source: Bowles NE, Bayston TA, Zhang HY, Doyle D, Lane RJ, Cunningham L, Archard LC. Persistence of enterovirus RNA in muscle biopsy samples suggests that some cases of chronic fatigue syndrome result from a previous, inflammatory viral myopathy. J Med. 1993;24(2-3):145-60. http://www.ncbi.nlm.nih.gov/pubmed/8409778

 

Enteroviruses and postviral fatigue syndrome

Abstract:

Postviral fatigue syndrome (PFS) occurs both in epidemics and sporadically. Many of the original epidemics were related to poliomyelitis outbreaks which either preceded or followed them.

The core clinical symptoms are always the same: severe fatigue made worse by exercise, myalgia, night sweats, atypical depression and excessive sleep. The other common symptoms include dysequilibrium disorders and irritable bowel syndrome.

We have detected enteroviral genome sequences in muscle biopsies from cases of PFS, using specific enteroviral oligonucleotide primers in the polymerase chain reaction (PCR). In addition, whole virus particles can be demonstrated in PCR-positive muscle, using solid-phase immuno-electron microscopy.

An increase in the number and size of muscle mitochondria was found in 70% of PFS cases, suggesting an abnormality in metabolic function. Evidence of hypothalamic dysfunction was present, particularly involving 5-hydroxytryptamine metabolism.

A putative model of PFS, based on persistent enteroviral infection in laboratory mice, revealed resolving inflammatory lesions in muscle with, however, a marked increase in the production of certain cytokines in the brain. This model may help to explain the pathogenesis of PFS.

 

Source: Behan PO, Behan WM, Gow JW, Cavanagh H, Gillespie S. Ciba Found Symp. 1993;173:146-54; discussion 154-9. http://www.ncbi.nlm.nih.gov/pubmed/8387908

 

Search for retrovirus in the chronic fatigue syndrome

Abstract:

AIM: To examine peripheral blood and skeletal muscle from patients with chronic fatigue syndrome for exogenous retrovirus.

METHODS: Blood samples from 30 patients and muscle biopsy specimens of 15 patients were examined for retroviral sequences by DNA extraction, polymerase chain reaction (PCR), and Southern blotting hybridisation. Sera were examined for human foamy virus by western immunoblotting and indirect immunofluorescence techniques.

RESULTS: No differences between the patient and control populations was found for any of the PCR primer sets used (gag, pol, env, and tax regions of HTLV I/II). An endogenous gag band was observed in both the patient and control groups. All sera were negative for antibody to human foamy virus.

CONCLUSION: The results indicate that there is no evidence of retroviral involvement in the chronic fatigue syndrome.

 

Source: Gow JW, Simpson K, Schliephake A, Behan WM, Morrison LJ, Cavanagh H, Rethwilm A, Behan PO. Search for retrovirus in the chronic fatigue syndrome. J Clin Pathol. 1992 Dec;45(12):1058-61. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC494996/ (Full article)

 

Amplification and identification of enteroviral sequences in the postviral fatigue syndrome

Abstract:

Evidence from several sources has long suggested that enteroviruses might play a role in the postviral fatigue syndrome (PVFS).

We used the most sensitive molecular virological method available at present, the polymerase chain reaction (PCR) amplification technique, to look for enteroviral copies in peripheral blood leucocytes and muscle from a well-defined group of patients. We demonstrated that our PCR method amplified a sequence common to a wide range of enteroviral serotypes. A highly significant number of the muscle biopsies (53%: P = less than 0.001) from the patients were positive for enteroviral sequences. With regard to the leucocyte samples, 16% in both patient and control were positive.

The PCR results on the peripheral blood leucocytes were in keeping with serological findings, in showing that the level of exposure to enteroviruses seemed to be the same in patients and controls: it was therefore of the greatest interest that patients were 6.7 times more likely to have enteroviral genome in their muscle.

We conclude that persistent enteroviral infection plays a role in the pathogenesis of PVFS, also providing preliminary evidence that severe mitochondrial injury is one of the mechanisms involved.

 

Source: Gow JW, Behan WM. Amplification and identification of enteroviral sequences in the postviral fatigue syndrome. Br Med Bull. 1991 Oct;47(4):872-85. http://www.ncbi.nlm.nih.gov/pubmed/1665380