Preferential expression of double-stranded ribonucleic acid in tumor versus normal cells: biological and clinical implications

In an effort to develop a new tumor marker suitable for flow cytometric analysis, we examined the value of double-stranded ribonucleic acid (ds- RNA) measurements using propidium iodide after DN'ase treatment. Cellular ds-RNA content was evaluated both in experimental cell lines and in clinical specimens. Higher levels of ds-RNA were present in tumor cells as compared with normal cells. In tumor cells, fluorescence was intensely localized in the nucleolus and was more diffuse in the cytoplasm. Change of less than 10% in the ds-RNA levels was observed in cell lines as a function of cytokinetic determinants such as cycle phase, culture age, and cycle traverse rate. Tumor differentiation by dimethylsulfoxide resulted in a significant decrease in cellular ds-RNA content. For quantitative comparison of clinical material, a ds-RNA excess was defined in relationship to normal peripheral blood lymphocytes. ds-RNA excess greater than 30% was observed in only one of 34 normal tissues (3%) as compared with 124 of 201 neoplastic tissue samples (62%). This incidence was higher in patients with acute leukemia (76%), high-grade and intermediate-grade lymphoma (75%), and high tumor stage myeloma (83%), as compared with chronic leukemia (20%), low-grade lymphoma (25%), and intermediate or low tumor mass myeloma (43%). Prognostically, a high pretreatment ds-RNA excess in myeloma was associated with a lower remission rate. The persistence of ds-RNA excess in the bone marrow of patients with acute myelogenous leukemia in remission predicted for a shorter remission duration (seven v 22 months; P = .05). We conclude that ds-RNA excess, as readily measured objectively and quantitatively by flow cytometry, may have important diagnostic and prognostic implications for the management of patients with malignant disease.     

Giant axonal neuropathy: observations on a further patient.

A further child with giant axonal neuropathy (GAN), abnormally curly hair and consanguineous parents is described. Of the 19 patients with GAN so far reported in the literature, six, including the present patient, have resulted from consanguineous marriages. This makes autosomal recessive inheritance of GAN highly probable. Our patient also exhibited cerebellar ataxia and signs of pyramidal tract damage; magnetic resonance brain imaging demonstrated abnormalities within the cerebellar and cerebral white matter. Myelinated nerve fibre density in the sural nerve was reduced to 6790/mm2 at age 8 years and had fallen to 3812/mm2 16 months later, indicating that progressive axonal loss occurs in GAN.     

Diphtheria with polyneuropathy in a closed community despite receiving recent booster vaccination

INTRODUCTION AND METHODS: We report 20 patients aged 18-24 years from Latvia with diphtheritic polyneuropathy. All lived in a closed community and 80% were known to have been fully vaccinated against diphtheria until at least 14 years old. Diphtheria antitoxin had been administered within 3 days of the onset of upper respiratory tract infection in 16 patients and 15 received antibiotics. RESULTS: Neurological symptoms developed after a median of 43 days (range 35-58) compared to only 10 days in previous studies of unvaccinated patients. All showed evidence of mild limb polyneuropathy with electrophysiological evidence of polyneuropathy. Only 30% showed early bulbar abnormalities compared to the usual rate of over 95% in diphtheritic polyneuropathy. However, 45% had later bulbar deterioration coinciding with the limb polyneuropathy. CONCLUSIONS: These patients show that an attenuated form of polyneuropathy of later onset, with less prominent early bulbar features, can occur in patients vaccinated against diphtheria according to schedule but living in a closed community in a country where diphtheria remains endemic.     

Screening of Tanzanian medicinal plants for anti-Candida activity

Background  

Candida albicans has become resistant to the already limited, toxic and expensive anti-Candida agents available in the market. These factors necessitate the search for new anti-fungal agents.