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Measuring the DNA telomere length of skeletal muscle in experienced endurance runners may contribute to our understanding of the effects of chronic exposure to endurance exercise on skeletal muscle. This study compared the minimum terminal restriction fragment (TRF) length in the vastus lateralis muscle of 18 experienced endurance runners (mean age: 42 +/- 7 years) to those of 19 sedentary individuals (mean age: 39 +/- 10 years). The runners had covered almost 50,000 km in training and racing over 15 years. Minimum TRF lengths measured in the muscle of both groups were similar (P = 0.805) and within the normal range. Minimum TRF length in the runners, however, was inversely related to their years spent running (r = -0.63, P = 0.007) and hours spent training (r = -0.52, P = 0.035). Therefore, since exposure to endurance running may influence minimum TRF length, and by implication, the proliferative potential of the satellite cells, chronic endurance running may be seen as a stressor to skeletal muscle.

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Sixty-one children (below 12 years) with midline dermal inclusions of the cranium and spine were operated on at the Red Cross War Memorial Children's Hospital between 1969-1990. The bregmatic area was the most common position for superficial cysts (33). Eight children had sinuses or cysts near the external occipital protuberance, 2 had isolated fourth ventricular cysts and 1 had a cyst in the quadrigeminal plate cistern. Fifteen children had spinal dermal inclusions, 13 of these were in the lumbosacral area, there was 1 sinus in the cervical spine and another in the midthoracic area attached to an intramedullary cyst. Two children had frontal sinuses, one of which was connected to an interhemispheric dermoid cyst and a lipoma of the corpus callosum. A midline swelling or sinus was the most common clinical presentation. Four out of 15 spinal inclusions and 1/11 occipital sinuses had a meningitic history. Five of 11 of the posterior fossa inclusions had raised intracranial pressure and signs suggestive of cerebellar tumor or abscess. Not one of the 33 bregmatic lesions had any connection to the central nervous system. MRI has proved useful in diagnosing both dermal sinuses and cysts, but CT scanning was our standard investigation. Plain x-ray revealed bony abnormalities in only 60% of our patients with spinal sinuses. We feel that all dermal sinuses or cysts in the midline should be surgically explored after CT or MRI scanning. Lesions mistaken for bregmatic cysts have included hemangiomas (4), hamartomas (2), an encephalocele through the anterior fontanelle (1) and lipomas (2).(ABSTRACT TRUNCATED AT 250 WORDS)

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Chronic fatigue in the athletic population is a common but difficult diagnostic challenge for the sports physician. While a degree of fatigue may be normal for any athlete during periods of high-volume training, the clinician must be able to differentiate between this physiological fatigue and more prolonged, severe fatigue which may be due to a pathological condition. As chronic fatigue can be the presenting symptom of many curable and harmful diseases, medical conditions which cause chronic fatigue have to be excluded. The clinician must then be able to differentiate between chronic fatigue associated with training or chronic fatigue from other medical causes, and also between the chronic fatigue syndrome and the overtraining syndrome. Once the clinician has excluded all of the above medical conditions which cause chronic fatigue in athletes, a significant proportion of fatigued athletes remain without a diagnosis. Novel data indicate that skeletal muscle disorders may play a role in the development of symptoms experienced by the athlete with chronic fatigue. The histological findings from muscle biopsies of athletes suffering from the 'fatigued athlete myopathic syndrome' are presented. We have designed a clinical approach to the diagnosis and work-up of the athlete presenting with chronic fatigue. The strength of this approach is that it hinges on the participation of a multidisciplinary team in the diagnosis and management of the athlete with chronic fatigue. The athlete, coach, dietician, exercise physiologist and sport psychologist all play an important role in enabling the physician to make the correct diagnosis.

The diagnosis of IDCS can rarely be entertained on clinical information alone. Microscopically, there is a wide spectrum of features. Thus, immunohistochemistry and electron microscopy are crucial in making the diagnosis. The differential diagnosis includes inflammatory pseudotumour, follicular dendritic cell sarcoma, true histiocytic lymphoma, malignant Langerhans cell histiocytosis, anaplastic large-cell lymphoma, melanoma, and a range of sarcomas. IDCS displays aggressive behaviour and approximately half of the patients die of the disease.