Evaluation of the antiviral activity against Junin virus of macrocyclic trichothecenes produced by the hypocrealean epibiont of Baccharis coridifolia.

Four macrocyclic trichothecenes, roridin A, roridin E, verrucarin A and verrucarin J, produced by the hypocrealean epibiont of Baccharis coridifolia, were evaluated for their inhibitory activity against the arenavirus Junin (JUNV), the etiological agent of Argentine hemorrhagic fever. The trichothecenes achieved a dose-dependent inhibition of JUNV multiplication at concentrations not affecting cell viability. The 50 % inhibitory concentration (IC50) values determined by a virus yield inhibition assay were in the range 1.2 - 4.9 ng/ml. The most active compound was verrucarin J which reduced JUNV yield more than 2 log units and had a similar effect against the arenavirus Tacaribe. The trichothecenes lacked virucidal effects on JUNV virions. From time of addition and removal experiments, it can be concluded that verrucarin J inhibited a late stage in the replicative cycle of JUNV, after 5 h of adsorption.

Metabolitos con actividad antiviral aislados de Curvularia pallescens / Antiviral activity metabolites isolated from Curvularia pallescens

The strain BAFC 2336 of Curvularia pallescens is a hyphomycete isolated from internal fungi present in leaves and stems of Baccharis coridifolia. Three compounds designated B, D1 and D2 which inhibited the replication of vesicular stomatitis virus (VSV) and herpes simplex virus type 1 (HSV-1) in tissue cultures were isolated from fluid cultures of Curvularia pallescens. The purification procedure of the compounds consisted first in an organic solvent extraction followed by chromatography through a silica gel column. Fractions eluted from the column with antiviral activity were pooled and then subjected to thin layer chromatography (TLC) in silica gel plates. Three isolated bands were recognized with Rf of 0.63, 0.36 y 0.33 for B, D1 and D2, respectively. The chromatographic characteristics of the isolated metabolites were determined by TLC and HPLC and their chemical structure by means of spectroscopic methods. Analysis of the data obtained indicated that compound D2 (MW: 280 Da) is identical with Brefeldin A a macrolide with antiviral activity isolated from other fungi but not reported to be present in Curvularia pallescens. Compound D1 is similar in structure to compound D2; however, the low amount obtained after purification unabled us to obtain complete structural characterization. Compound B (MW: 332 Da) has an aromatic ring and a chemical structure related to curvularins, a generic name for certain metabolites from Curvularia. This compound appears to be a novel compound with antiviral potency similar to Brefeldin A, but less toxic.

Metabolitos con actividad antiviral aislados de Curvularia pallescens / Antiviral activity metabolites isolated from Curvularia pallescens

The strain BAFC 2336 of Curvularia pallescens is a hyphomycete isolated from internal fungi present in leaves and stems of Baccharis coridifolia. Three compounds designated B, D1 and D2 which inhibited the replication of vesicular stomatitis virus (VSV) and herpes simplex virus type 1 (HSV-1) in tissue cultures were isolated from fluid cultures of Curvularia pallescens. The purification procedure of the compounds consisted first in an organic solvent extraction followed by chromatography through a silica gel column. Fractions eluted from the column with antiviral activity were pooled and then subjected to thin layer chromatography (TLC) in silica gel plates. Three isolated bands were recognized with Rf of 0.63, 0.36 y 0.33 for B, D1 and D2, respectively. The chromatographic characteristics of the isolated metabolites were determined by TLC and HPLC and their chemical structure by means of spectroscopic methods. Analysis of the data obtained indicated that compound D2 (MW: 280 Da) is identical with Brefeldin A a macrolide with antiviral activity isolated from other fungi but not reported to be present in Curvularia pallescens. Compound D1 is similar in structure to compound D2; however, the low amount obtained after purification unabled us to obtain complete structural characterization. Compound B (MW: 332 Da) has an aromatic ring and a chemical structure related to curvularins, a generic name for certain metabolites from Curvularia. This compound appears to be a novel compound with antiviral potency similar to Brefeldin A, but less toxic.(AU)

A study of adult T-cell leukemia/lymphoma incidence in central Brooklyn.

Adult T-cell leukemia/lymphoma (ATL), a rare outcome of infection with human T-lymphotropic virus (HTLV-I), is endemic in central Brooklyn, which has a large Caribbean migrant population. Previous studies have suggested that HTLV-I prevalence in central Brooklyn may be similar to that recorded in the Caribbean islands. We established a pilot 1-year surveillance program to identify cases of ATL in 7 of 10 hospitals serving the residents of 18 zip codes of central Brooklyn with a combined population of 1,184,670. Of the 6,198 in-patient beds in the catchment area, approximately 83% were covered. Twelve incident cases of ATL were ascertained, all among persons of Afro-Caribbean descent, indicating an annual incidence in African-Americans in this community of approximately 3.2/100,000 person-years. Unexplained hypercalcemia was the most useful screening method, identifying 3 of 5 patients not referred for possible ATL by a local hematologist. The female:male ratio was 3:1. The age pattern was different from that reported in the Caribbean Basin and closer to the pattern seen in Japan. Our study supports evidence that HTLV-I infection and ATL are endemic in central Brooklyn and suggests that a more intensive surveillance program for this disease coupled with intervention efforts to reduce HTLV-I transmission are warranted.

[Antiviral activity metabolites isolated from Curvularia pallescens]. / Metabolitos con actividad antiviral aislados de Curvularia pallescens.

The strain BAFC 2336 of Curvularia pallescens is a hyphomycete isolated from internal fungi present in leaves and stems of Baccharis coridifolia. Three compounds designated B, D1 and D2 which inhibited the replication of vesicular stomatitis virus (VSV) and herpes simplex virus type 1 (HSV-1) in tissue cultures were isolated from fluid cultures of Curvularia pallescens. The purification procedure of the compounds consisted first in an organic solvent extraction followed by chromatography through a silica gel column. Fractions eluted from the column with antiviral activity were pooled and then subjected to thin layer chromatography (TLC) in silica gel plates. Three isolated bands were recognized with Rf of 0.63, 0.36 y 0.33 for B, D1 and D2, respectively. The chromatographic characteristics of the isolated metabolites were determined by TLC and HPLC and their chemical structure by means of spectroscopic methods. Analysis of the data obtained indicated that compound D2 (MW: 280 Da) is identical with Brefeldin A a macrolide with antiviral activity isolated from other fungi but not reported to be present in Curvularia pallescens. Compound D1 is similar in structure to compound D2; however, the low amount obtained after purification unabled us to obtain complete structural characterization. Compound B (MW: 332 Da) has an aromatic ring and a chemical structure related to curvularins, a generic name for certain metabolites from Curvularia. This compound appears to be a novel compound with antiviral potency similar to Brefeldin A, but less toxic.

Nutritional requirements for growth of an endophyte: Ceratopycnidium baccharidicola.

The carbon sources, nitrogen sources and vitamin requirements for the growth of Ceratopycnidium baccharidicola (an endophyte of Baccharis coridifolia) were studied. The fungus utilized several carbon sources: pectin, sucrose, fructose, glucose, maltose, cellobiose, xylose, arabinose, mannitol, mannose and sorbitol. Sucrose and fructose were found to be the best carbon sources. Nitrogen sources utilized by the endophyte included: nitrates, ammonium and amino acids such as proline, asparagine and glycine. Undefined complex nitrogen sources such as soytone, tryptone, yeast extract and casamino acids supported excellent growth. In a defined medium, thiamine was the only vitamin required for growth. Under optimum conditions the vegetative growth of C. baccharidicola was enhanced six fold over its growth in glucose-asparagine medium.

[Fungal endophytes in Juncus imbricatus var chamissonis: identification of colonization patterns.]. / Endofitos fúngicos en Juncus imbricatus var chamissonis: identificación de los patrones de colonización.

Colonization patterns corresponding to individual endophytic species were observed in asymptomatic leaves and culms of Juncus imbricatus var chamissonis, a perennial plant. The presence of the fungi within the host was demonstrated by light microscopy after the cleaning and staining of tissues. The main endophytic species, Pleospora aff togwotiensis, was found colonizing the substomatal chamber and growing intercellularly between mesophyll cells. In a second colonization pattern, an unknown fungus was restricted to a single host epidermal cell, showing similar characteristics to other fungal taxa observed on Juncus effusus var pacificus, Pseudotsuga menziessii and Fagus sylvatica. A third colonization pattern, where the mycelium is confined to the substomatal chamber, was also described.

The sterols of Cucurbita moschata ("calabacita") seed oil.

From the sterol fraction of seed oil from commercial Cucurbita moschata Dutch ("calabacita") delta 5 and delta 7 sterols having saturated and unsaturated side chain were isolated by chromatographic procedures and characterized by spectroscopic (1H and 13C-nuclear magnetic resonance, mass spectrometry) methods. The main components were identified as 24S-ethyl 5 alpha-cholesta-7,22E-dien-3 beta-ol (alpha-spinasterol); 24S-ethyl 5 alpha-cholesta-7,22E,25-trien-3 beta-ol (25-dehydrochondrillasterol); 24S-ethyl 5 alpha-cholesta-7,25-dien-3 beta-ol; 24R-ethyl-cholesta-7-en-3 beta-ol (delta 7-stigmastenol) and 24-ethyl-cholesta-7, 24(28)-dien-3 beta-ol (delta 7,24(28)-stigmastadienol).