Oestrogen influence on myogenic satellite cells following downhill running in male rats: a preliminary study

AIM

This study examined the effect of oestrogen supplementation in rats on myogenic satellite cell quantities in type I and II muscles following eccentric exercise.

METHODS

Gonad intact adult male rats divided into four groups, oestrogen supplemented (25 mg oestrogen pellet) control (EC), oestrogen supplemented, exercised (EE), sham (no oestrogen) control (SC) and sham, exercised (SE). After 1 week of oestrogen exposure the EE and SE animals performed 90 min of intermittent downhill running (5 min running/2 min rest @-13.5 degrees incline and 17 m min(-1) speed). Seventy-two hours later exercised (EE and SE) and control (EC and SC) animals were killed and blood samples taken and soleus and white (superficial) vastus muscles surgically removed. Histochemical sections of soleus and white vastus muscles were examined for myogenic satellite cell content by use of Pax7 antibody and for neutrophil content by use of haematoxylin and eosin (H and E) staining procedures.

RESULTS

Downhill running resulted in significant elevations in satellite cells and neutrophils detected in both soleus and white vastus muscle samples (P < 0.01). Interestingly, oestrogen supplementation resulted in significantly greater (P < 0.01) post-exercise elevations in satellite cells detected in both soleus and white vastus muscle samples compared with sham (no oestrogen) rats. Increases in neutrophils were significantly (P < 0.05) attenuated in oestrogen supplemented rats relative to sham in soleus but not in white vastus muscles.

CONCLUSIONS

Oestrogen supplementation in male rats may have accentuated the 72 h post-downhill running increase in Pax7 detected myogenic satellite cell number in both soleus and white vastus muscles relative to unsupplemented rats. The mechanisms and physiological consequences of this effect are yet to be determined.

[Prevention of coronary heart disease by therapy of hyperlipidemia. Between cholesterol hysteria and therapeutic realism]

OBJECTIVES

The present paper is intended to provide an overview of the arguments for and against drug treatment of hyperlipidemia.

MAJOR TOPICS

An argument in support of lipid-lowering prophylactic and therapeutic programs is the close relationship between lipid levels and coronary heart disease, which has been documented both epidemiologically and by interventional studies. Arguments against comprehensive treatment of hyperlipidemia have to do with the fact that although large interventional studies have shown a reduction in mortality from coronary heart disease, there has been no reduction in overall mortality. Of decisive importance for the decision to apply lipid-lowering treatment is the overall risk profile of the patient concerned. This includes not only pathological lipid levels, but also numerous other factors that must be taken into account when considering the indication.

CONCLUSIONS

Whether to initiate lipid-lowering treatment or not should be determined on the basis of the individual patient's risk profile, with additional consideration being given to age and sex.

[Short- and intermediate-term angular results of Cüppers retro-equatorial myopexy, with or without additional simultaneous recession]

79 variable esotropias underwent bilateral "Fadenoperations". In the first group, the posterior fixation has been performed alone. In the second series, conventional symmetrical recessions of the medial recti have been performed during the same procedure. Two further additional weakening techniques are compared in the last group: anterior medial tenotomies and the so-called "stretch effect". Concomittant recessions considerably enforced the amount of angle reduction for distance and near without affecting precision, predictibility and stability of the results. Tenotomies and stretching procedures were followed by inconstant results.

Why should surgery for early-onset strabismus be postponed?

The author presents a continued study of 82 cases of pseudoparalysis of the bilateral rectus muscles in early-onset convergent strabismus following early surgery. Up to 10 years after surgery motor results show that 72% of cases remain within +/- 10 prism dioptres after a single surgical procedure. Sensorial findings corroborate the results of other authors' studies in that binocular association is only achieved in those patients where surgery was carried out at a very young age, not older than 1 year. Surgical procedures consisting of bimedial rectus recession with retroequatorial myopexy are described and the development of alphabetical syndromes and dissociated vertical divergence discussed. The evolution of refraction in these cases is also shown.

[Endocrine ophthalmopathy]

The author lists the various ocular complications of Graves' disease, ranging from the very mild, which need no treatment, to those which require medical treatment, usually with cortisone, sometimes in combination with immunosuppressors. The relatively slight oculomotor problems can sometimes be alleviated with prisms. More serious complications require surgery of the extraocular muscles, which is not discussed in this paper.

[Vicryl in cataract surgery: a step toward the ideal suture]

On the basis of a study of 35 cataracts, of which 16 were in bilateral cases where both eyes were operated on simultaneously, the author shows that in the search for the ideal suture, it is worth trying a reabsorbable material. Vicryl is without doubt to be recommended in view of its easy handling once one is familiar with it, its reliability, regular reabsorption period, good tolerance by patients, minimal inflammatory reaction and the absence of any complications that may be attributed to it.

[The surgical treatment of superior oblique paralysis (author's transl)]

The line of treatment drawn out by Malbran more than 20 years ago has lost none of its standing. However, although the main principles are still valid, the surgical protocol should be modified in view of the evolution of the surgical concept and technique for which we are indebted to Cüppers. The so-called "thread operation", which the author proposes to call the "Retroequatorial Myopexy of Cüppers" brings a decisive progress. Combined with the primary effect on the paralysis muscle, it also elegantly solves the three problems of this paralysis, namely hyperphoria, excyclophoria, and muscular incomitance. The ideal surgical plan includes now a Superior Oblique Tuck of the affected muscle, with a Retroequatorial Myopexy of the Inferior Rectus of the sound eye, either in the same operation or separately. The muscle weakening procedures by the traditional recession should be avoided.