Cellular and humoral responses to collagen-polyvinylpyrrolidone administered during short and long periods in humans

Collagen, particularly type I, and its related derivatives have been extensively employed in many areas of pharmacology. The present study was performed to determine the safety of collagen-polyvinylpyrrolidone (collagen-PVP) by in vitro and in vivo studies. Sera and peripheral blood cells from healthy donors without treatment and patients treated with collagen-PVP were evaluated. We observed that the biodrug does not stimulate lymphoproliferation or DNA damage in vitro, nor does it induce human anti-porcine type I collagen or anti-collagen-PVP antibodies in vivo. Furthermore, no hepatic or renal metabolic dysfunctions were observed when collagen-PVP was administered by intradermal or intramuscular routes in short- or long-term treatments. In conclusion, the present work shows that no cellular damage or immunological adverse effects (cellular and humoral) occurred during collagen-PVP treatment, even after more than 400 weeks of consecutive administrations.     

In vitro evaluation of antibacterial substances produced by bacteria isolated from different marine organisms

Bacteria from several groups of marine organisms were isolated and, using direct antibiograms, identified those that produce antibacterial substances, using a human pathogenic strain of Staphylococcus aureus ATCC6538 as revealing microorganism. Bacteria which produce substances that inhibited S. aureus growth were identified through morphological, physiological and biochemical tests. Out of 290 bacteria, 54 (18.6%) inhibited the growth of S. aureus, but only 27 survived for identification. Bivalves, sponges and corals were the most represented from which 41.2, 33.3 and 29.7%, respectively, produced antibacterial substances of the isolated bacteria in each group. The marine species with highest proportions of these bacteria were the hard coral Madracis decactis (62.5%), the sponges Cliona sp. (57.1%) and the octocoral Plexaura flexuosa (50.0%). Out of the 27 strains that produced antibacterial substances, 51.8% were Aeromonas spp. and 14.8% Vibrio spp. Marine bacteria that produce antibacterial substances are abundant, most belong in the Vibrionacea group and were isolated mainly from corals and bivalve mollusks.     

Effect of initial glucose concentration and inoculation level of lactic acid bacteria in shrimp waste ensilation

Fermentation conditions and microorganisms were determined, based on acid production, glucose concentration as carbohydrate source. Inoculation levels to obtain a stable shrimp waste silage were also determined. Shrimp waste ensilation was an efficient method of preservation, allowing the recovery of chitin and another added-value products such as pigments, proteins and enzymes. From the various lactic acid bacteria tested, Lactobacillus pentosus and Lactobacillus sp. (B2) were the best lactic acid producers, although small quantities of acetic acid were detected in samples inoculated with Lactobacillus pentosus. Therefore B2 was chosen for the analysis of glucose consumption as well as for the determination of optimum inoculation levels. The best results were obtained at 10% (w/w wet basis) and 5% (v/w wet basis) respectively. Presence of starters and initial glucose concentration were critical factors in the fermentation of shrimp waste. High initial glucose and starter concentrations reduced the time and increased the amount of lactic acid produced. The fermentation pattern changed during ensilation from hetero to homofermentative. Shrimp waste ensilation prevented the growth of spoilage microorganisms keeping their microbial counts steady and pH values within the acid region.     

Human cytomegalovirus immediate early proteins and cell growth control

It is widely accepted that small DNA tumor viruses, such as adenovirus, simian virus 40 and papillomavirus, push infected cells into S-phase to facilitate the replication of their genome. Until recently, it was believed that the large DNA viruses (i.e. herpesviruses) functioned very differently in this regard by inducing a G₁ arrest in infected cells as part of their replication process. However, studies over the last 6–8 years have uncovered striking parallels (and differences) between the functions of the major immediate early (IE) proteins of at least one herpesvirus, human cytomegalovirus (HCMV) and IE equivalents encoded by small DNA tumor viruses, such as adenovirus. Similarities between the HCMV major IE proteins and adenovirus IE proteins include targeting of members of the RB and p53 families and an ability of these viral factors to induce S-phase in quiescent cells. However, unlike the small DNA tumor virus proteins, individual HCMV IE proteins target different RB family members. HCMV also encodes several other IE gene products as well as virion tegument proteins that act early during infection to prevent an infected cell from replicating its host genome and from undergoing apoptosis. Here, we review the specifics of several HCMV IE proteins, two virion components, and their functions in relation to cell growth control.     

Synthesis and antiparasitic activity of 1H-benzimidazole derivatives

Compounds 1-18 have been synthesized and tested in vitro against the protozoa Giardia lamblia, Entamoeba histolytica and the helminth Trichinella spiralis. Inhibition of rat brain tubulin polymerization was also measured and compared for each compound. Results indicate that most of the compounds tested were more active as antiprotozoal agents than Metronidazole and Albendazole. None of the compounds was as active as Albendazole against T. spiralis. Although only compounds 3, 9 and 15 (2-methoxycarbonylamino derivatives) inhibited tubulin polymerization, these were not the most potent antiparasitic compounds.     

Patterns of genetic variation in Pinus chiapensis,a threatened Mexican pine,detected by RAPD and mitochondrial DNA RFLP markers

Pinus chiapensis (Pinaceae) is a large conifer, endemic to central and southern Mexico and north-western Guatemala. In order to assess the extent of genetic variation within and between populations of this species, samples were obtained from throughout the natural range and analysed using random amplified polymorphic DNA (RAPD) and mtDNA RFLPs markers. Probes for the CoxI mitochondrial gene enabled two mitotypes to be observed. Populations from the eastern and western limit of the range of the species were fixed for one mitotype ('A'), whereas two populations distributed near the centre of the range were fixed for another ('B'). When the samples were screened with eight 10-mer RAPD primers, a total of 12 polymorphic bands were detected. The proportion of polymorphic bands was unusually low (24.5%) compared with other tree species. AMOVA analysis indicated that a significant proportion of the variation (P < 0.002) was distributed between populations; the extent of population differentiation detected (Phi(st) = 0.226; G(ST ) = 0.194) was exceptionally high for a pine species. Pair-wise comparison of Phi(st) values derived from AMOVA indicated that populations were significantly (P < 0.05) different from each other in virtually every case. These results are interpreted in the context of the evolutionary history of the species, and the implications for its in- and ex situ conservation are discussed.     

Trichothecenes and zearalenone production by fusarium species isolated from Argentinean black beans

Isolates of Fusarium species obtained from freshly harvested bean grains for human consumption collected from different Argentinean regions, were investigated for their ability to biosynthesise trichothecenes and zearalenone either on rice grains or beans. Low incidence of toxigenic fungi was observed. These mycotoxigenic species produced several toxins when grown on rice but none or little amount when cultured on beans. The results of this report suggest that contamination of Argentinean beans with Fusarium mycotoxins will not be common and therefore people would be at low mycotoxicosis risk through consumption of beans.