Several species of the genus Euphorbia (Euphorbiaceae) have been tested for their efficiency as antiviral and antitumour agents, partly based on information concerning plants that have traditionally been used as medication to treat various human diseases (Bernal & Correa 1990, Unander et al. 1995. In fact, pronounced antiviral activity has been reported in several species of the genus Euphorbia, against polio, coxsackie, and rhinoviruses (Vlietinck et al. 1986, 1995, Ninomiya et al. 1990, Unander et al. 1995. Additionally, antitumour activity against sarcoma 180 ascites, leukemia in mice, and cytotoxic activity against certain cancer cell lines has also been observed (Itokawa et al. 1989, Wu et al. 1991, Fatope et al. 1996.There seems to be increasing possibility of finding biological activity among plants with recorded medicinal uses rather than from plants randomly selected (Unander et al. 1995, Cordell 1995. Furthermore, selection of plants gives better criteria for screening programs especially in its initial phases, compared to the screening of compounds isolated and/or purified from natural products (Kusumoto et al. 1995, Cordell 1995, Baker et al. 1995.Finally, the strategy for research and in vitro evaluation of biological activity of natural products, has changed in the past few years. One of the recent developments is the highly automated bioassay screening method based on colorimetric assays, that quantify the proliferation of cell cultures (Mosmann 1983, Denizot & Lang 1986). These techniques, considered rapid and inexpensive for the evaluation of antitumour (Carmichael et al. 1987, Rubinstein et al. 1990) and antiviral activity (Weislow et al. 1989) of a large number of natural products, have also permitted the isolation and purification of biologically active principles (Cordell 1995, Baker et al. 1995.The objective of our work was to evaluate, using colorimetric assays, the in vitro antiherpetic and cytotoxic activity of some Euphorbia species that are known in Colombia, to have traditional medical uses against skin infections such as ulcers, warts, cancers, tumors, and possibly diseases of viral origin (Garcia-Barriga 1974, Perez 1975, Vasquez 1982, Bernal & Correa 1990, Piñeros et al. 1992. MATERIALS AND METHODSPlant collection -The species were collected in different municipalities of the Department of Antioquia and deposited in the herbarium of the University of Antioquia, Medellín, Colombia. E. cotinifolia, was collected in Girardota, at a mean altitude of 350 m; a voucher specimen was deposited under the number HUA 115472. E. cestrifolia was collected in Guarne, at a mean altitude of 2,000 m; a voucher specimen was deposited under the number HUA 95065. E. tirucalli, E. arenaria, and E. pulcherrima were collected in Medellín, at a mean altitude of 450 m; voucher specimens were deposited under the numbers RC11383, HUA 55275, RC11384, respectively. The species E. heterophyla, E. cyatophora, E. graminea, E. cf. cotinifolia and Euphorbia sp. were collected in San Jerónimo, at a mean altitude of...

Hepatitis E virus (HEV) genotype 3 produces zoonotic infection associated with the consumption of infected animals. HEV infections can become chronic in immunocompromised (IC) patients. The viral genome has three well defined open reading frames (ORF1, ORF2 and ORF3) within which various domains and functions have been described. This paper (i) describes a new method of complete sequencing of the HEV coding region through overlapping PCR systems, (ii) establishes a consensus sequence and polymorphic positions (PP) for each domain, and (iii) analyzes the complete coding sequence of an IC patient. With regard to the consensus, a high percentage of PP was observed in protease (PP=19%) and the X domain (PP=22%) within ORF1, the N-terminal region of the S domain (PP=22%) in ORF2, and the P1 (PP=35%) and P2 (PP=25%) domains in ORF3. In contrast, the ORF1 Y, ORF2 S, ORF2 M and ORF3 D1 domains were conserved in the reference sequences (0.40, 1, 0.70 and 0% of PP, respectively). The sequence from the IC patient had more mutations in the RpRp (D1235G, Q1242R, S1454T, V1480I, I1502 V, K1511R, G1373 V, E1442D, V1693 M), the terminal ORF2 S- domain (F10L, S26T, G36S, S70P, A105 V, I113 V), the X domain (T938 M, T856 V, S898A) and the helicase (S1014N, S975T, Q1133 K).

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Synthetic peptides derived from the amino acid sequence of MTP40, a recently characterized Mycobacterium tuberculosis protein, were tested by two different immunological assays in 91 individuals. For the purposes of this study, the population was distributed in four groups: active tuberculosis (TBC) patients with elevated bacillus loads (BK+), active TBC patients with low bacillus loads (BK-), healthy individuals living in the same household with tuberculous patients (HH), and normal individuals, who had presumably never been in contact with the bacilli (control). We found that T cells of individuals belonging to the HH group showed the highest and most frequent recognition of these peptides in a T-cell proliferation assay, while their antibodies showed the lowest recognition of these peptides when tested by enzyme-linked immunosorbent assay. In contrast, TBC patients revealed an inverse pattern of immune response. Interestingly, one of these peptides (P7) was recognized by T cells of 64% of the HH individuals and by 4.5% of normal donors. Another peptide (P4) was recognized by 55% of sera from BK+ patients and by 5.5% of normal donors. The results presented here indicate the existence of T-and B-cell epitopes within the MTP40 protein. Given the particular recognition pattern of this protein, added to the fact that it appears to be a species-specific antigen of M. tuberculosis, a detailed study of the immune response to it may be useful in the design of more accurate diagnostic tests and an improved vaccine against human TBC.

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