Do mosses really exhibit so large distribution ranges? Insights from the integrative taxonomic study of the Lewinskya affinis complex (Orthotrichaceae, Bryopsida).

The strikingly lower number of bryophyte species, and in particular of endemic species, and their larger distribution ranges in comparison with angiosperms, have traditionally been interpreted in terms of their low diversification rates associated with a high long-distance dispersal capacity. This hypothesis is tested here with Lewinskya affinis (≡ Orthotrichum affine), a moss species widely spread across Europe, North and East Africa, southwestern Asia, and western North America. We tested competing taxonomic hypotheses derived from separate and combined analyses of multilocus sequence data, morphological characters, and geographical distributions. The best hypothesis, selected by a Bayes factor molecular delimitation analysis, established that L. affinis is a complex of no less than seven distinct species, including L. affinis s.str., L. fastigiata and L. leptocarpa, which were previously reduced into synonymy with L. affinis, and four new species. Discriminant analyses indicated that each of the seven species within L. affinis s.l. can be morphologically identified with a minimal error rate. None of these species exhibit a trans-oceanic range, suggesting that the broad distributions typically exhibited by moss species largely result from a taxonomic artefact. The presence of three sibling western North American species on the one hand, and four Old World sibling species on the other, suggests that there is a tendency for within-continent diversification rather than recurrent dispersal following speciation. The faster rate of diversification as compared to intercontinental migration reported here is in sharp contrast with earlier views of bryophyte species with wide ranges and low speciation rates.

Neurological aspects of mycoplasmal infection.

Mycoplasmal infections may be complicated by a wide variety of systemic syndromes, including neurological disorders. Circumstantial evidence suggests that these are immunologically-induced. A detailed study of five patients with proven mycoplasma pneumoniae and central nervous system signs showed that immunological factors were involved and suggested that the neurological symptoms were due to a vasculopathy.

Does Toxoplasma cause polymyositis? Report of a case of polymyositis associated with toxoplasmosis and a critical review of the literature.

We report here a case of polymyositis and toxoplasmosis, and review the previous examples of this association. We suggest that in most cases this relationship is due to reactivation of latent infection in an immunocompromised host. Gross immunological aberrations underline the pathogenesis of polymyositis and these predispose the patient to the development of toxoplasmosis. Anti-protozoal therapy is necessary and produces some clinical benefit, but it does not cure the polymyositis.

Flaccid quadriparesis due to Salmonella enteritis.

A case of profound myopathy due to electrolyte disturbances secondary to salmonella enteritis is reported. The relationship between hypomagnesaemia, hypocalcaemia and parathyroid hormone secretion is also demonstrated.