Restriction endonuclease analysis of mitochondrial DNA as an aid in the taxonomy of Naegleria and Vahlkampfia

Using restriction enzyme analysis, mitochondrial DNA fragment patterns from seven strains of pathogenic and nonpathogenic Naegleria and one strain of Vahlkampfia were compared to estimate nucleotide sequence divergence. Significantly high levels of estimated genetic variation between strains of N. gruberi, N. fowleri, and N. jadini support the current taxonomic level of the individual Naegleria species and suggest a distinct phylogeny for each group. Naegleria lovaniensis, strain TS, was shown to have significant nucleotide sequence homology with N. gruberi, strain EGs, suggesting that the two groups share a close taxonomic relationship. The pathogenic strain MB-41 of N. fowleri exhibited distinct genetic divergence from the highly homologous, pathogenic strain Nf66 and the drug-cured strain 6088. Morphologically distinct strains EGs and 1518/la of N. gruberi exhibited significantly large sequence divergence consistent with a more distant taxonomic relationship. Amoebae from the genus Vahlkampfia expressed genetic similarity with strains of N. gruberi.     

Hydatidiform mole metastasizing to the lung.

Pulmonary lesions developed in three patients with an invasive hydatidiform mole. At open thoracotomy the modules were found to contain molar tissue. Therapy with twice-weekly methotrexate induced complete clinical and biologic remission of the disease in all three patients.     

High-dose diethylstilbestrol diphosphate therapy of prostatic cancer after failure of standard doses of estrogens

Ten patients with metastatic prostatic cancer no longer responsive to conventional doses of estrogens (stilbestrol 15 mg. daily or equivalent) were treated with high doses of diethylstilbestrol diphosphate. Objective responses lasting from three to fifteen months were obtained in four patients; three of the patients had previously shown progressive disease following orchidectomy.Toxic manifestations consisted mainly of increased gynecomastia and water retention. No serious cardiovascular complications were encountered. This dose-response effect of estrogens indicates the persistence of hormone-dependent tumours in some patients with recurrent disease despite conventional estrogen therapy.     

Seed survival and persistence on a calcareous land surface after a 32-year burial

Abstract. Of 34 species of vascular plants recorded in an unimproved calcareous grassland community in 1960 and subsequently buried for 32 yr, just six spp. were recovered as viable seeds from the original land surface, following excavation of an experimental earthwork. Five of the six are known or suspected to form persistent seed banks; the status of Carex flacca as a persistent seed is now established. The exceptionally low density of viable seeds at 35 seeds/m² and the paucity of other plant remains confirm that these calcareous soils have supported rapid decomposition. The complete absence of viable seeds known to be short-lived indicated that the macrofauna has played no significant role in the introduction of viable seeds from the modern-day surface down to depths in excess of 1.6 m, at least not in recent years. Because of the precise dates of burial and excavation, the results offer a rare opportunity to confirm laboratory and other indirect observations of long-term seed persistence following burial in temperate climate calcareous soils.