Miniaturized saturated absorption spectrometer.

We describe a saturated absorption spectrometer that is robust and compact and requires minimum alignment, which is made possible by using a diffuse probe beam generated by a retro-reflecting film. This concept was studied and implemented in a miniaturized home-built setup that provides the same performance as an optimized table-top setup.

Isolation and characterization of canine parvovirus type 2c (CPV-2c) from symptomatic puppies

Canine parvovirus type 2 (CPV-2) is a leading cause of diarrhea in puppies in several parts of the world. In this study CPV-2 was detected and recovered from puppies showing clinical disease from Montevideo, Uruguay. Samples were processed and used to infect CRFK and MDCK cells in order to isolate the virus. Out of twelve, two samples were positive for CPV-2. A genomic region of 583 bp was amplified and the molecular characterization was performed by sequencing, phylogenetic analysis and Restriction Fragment Length Polymorphism (RFLP). Two isolated viruses (UY1 and UY2) were CPV-2c-like viruses. The comparison between the cytophatic effect (CPE) of CPV-2 (vaccinal virus) and CPV-2c (isolated virus) on primary canine cells cultures and on CRFK line cells, demonstrated that CPV-2c is less citopathogenic in CRFK than in primary cultures. Our study represents the first report on isolation and characterization of canine parvovirus type 2c (CPV-2c) in cell cultures from South American dogs.

Isolation and characterization of canine parvovirus type 2C (CPV-2C) from symptomatic puppies.

Canine parvovirus type 2 (CPV-2) is a leading cause of diarrhea in puppies in several parts of the world. In this study CPV-2 was detected and recovered from puppies showing clinical disease from Montevideo, Uruguay. Samples were processed and used to infect CRFK and MDCK cells in order to isolate the virus. Out of twelve, two samples were positive for CPV-2. A genomic region of 583 bp was amplified and the molecular characterization was performed by sequencing, phylogenetic analysis and Restriction Fragment Length Polymorphism (RFLP). Two isolated viruses (UY1 and UY2) were CPV-2c-like viruses. The comparison between the cytophatic effect (CPE) of CPV-2 (vaccinal virus) and CPV-2c (isolated virus) on primary canine cells cultures and on CRFK line cells, demonstrated that CPV-2c is less citopathogenic in CRFK than in primary cultures. Our study represents the first report on isolation and characterization of canine parvovirus type 2c (CPV-2c) in cell cultures from South American dogs.

Antifungal activity of sakurasosaponin from the root extract of Jacquinia flammea.

The methanolic crude extract from the roots of Jacquinia flammea showed moderate antifungal activity against dermatophytes and very strong antifungal activity against Colletotrichum gloeosporioides. The bioassay-guided purification of the extract, using a combination of vacuum-liquid chromatography and high performance liquid chromatography, allowed the identification of sakurasosaponin as the main metabolite responsible for the antifungal activity.

Antiprotozoal activity of betulinic acid derivatives.

Betulinic acid (1), isolated from the crude extract of the leaves of Pentalinon andrieuxii (Apocynaceae), together with betulinic acid acetate (2), betulonic acid (3), betulinic acid methyl ester (4), and betulin (5) were evaluated for their antiprotozoal activity. The results showed that modifying the C-3 position increases leishmanicidal activity while modification of the C-3 and C-28 positions decreases trypanocidal activity.

Evaluation of the biological activity of crude extracts from plants used in Yucatecan traditional medicine. Part II. DNA-interacting activity.

Extracts from leaves, stems, and roots of twelve plants used commonly in Yucatecan traditional medicine were evaluated in the DNA-methyl green assay. Twenty one extracts showed DNA-interacting activity, and nine of them, belonging to five plant species, presented a displacement activity of 5% or higher. The highest activity (17.6%) was detected in the leaf extract of Heliotropium angiospermum.

Evaluation of biological activity of crude extracts from plants used in Yucatecan traditional medicine part I. Antioxidant, antimicrobial and beta-glucosidase inhibition activities.

Bioactivity of extracts from leaves, stems and roots of twelve plants commonly used in Yucatecan traditional medicine were evaluated in four bioassays. Crude extracts from ten plants showed significant activity in the inhibition of bleaching of beta-carotene assay, while thirteen extracts showed activity in the reduction of 2, 2- diphenyl-1-picrylhydrazyl radical (DPPH) assay. In the antimicrobial bioassay, the major activity was presented by the root extract of Jatropha gaumeri and in the beta-glucosidase inhibition activity assay the strongest activity was observed in the stem and root extracts of Solanum hirtum.

Tagetolone and tagetenolone: two phytotoxic polyketides from Alternaria tagetica.

Two new phytotoxic polyketides, tagetolone (1) and tagetenolone (2), in addition to tyrosol and p-hydroxybenzoic acid, have been isolated from the organic crude extract of culture filtrates from the fungal pathogen Alternaria tagetica. Complete characterization of all structures was carried out following a careful analysis of their spectroscopic data (IR, MS, (1)H and (13)C NMR, and 2D NMR experiments).

Novel dimeric metabolites from Alternaria tagetica.

Two novel polyketides, bis-7-O-8' '.8-O-7' '- and bis-7-O-7' '. 8-O-8' '-zinniol (2 and 3, respectively) were isolated from the organic crude extract of culture filtrates from Alternaria tagetica. Both structures were determined on the basis of their spectroscopic data (IR, MS, (1)H NMR, (13)C NMR, and 2D NMR experiments) and confirmed by chemical synthesis. Zinniol (1) was isolated as a major component, and its (13)C NMR data was correctly assigned after careful analysis of data from its 2D NMR experiments (HMQC and HMBC).

Enamel matrix derivative in periodontal reconstructive surgery. A new approach in periodontal regeneration.

True periodontal regeneration is the goal of any periodontal regenerative techniques. Cementum formation is a key event in the development of root and supporting periodontium. Due to its distribution, acellular cementum is the type most affected by early to moderate periodontitis. Studies over the past twenty years demonstrated that, enamel matrix proteins from the root sheath are involved in the formation of acellular, during tooth development. Thus the adjunctive use of enamel matrix derivatives in conjunction with regenerative periodontal surgery could possibly lead to true periodontal regeneration. The purpose of this article is to review the use of enamel matrix derivative in true periodontal regeneration.

Synthesis of polyetherurethanes containing L-serine dipeptide and their use as materials for biomedical films.

Prepolymers, which were produced by the polyaddition reaction of polytetramethylene glycol (PTMG) or polyethylene glycol (PEG) and 4,4'-diphenylmethane diisocyanate (MDI) or hexamethylene diisocyanate (HMDI), were chain-extended with a linear dipeptide of L-serine (Z-Ser-Ser-OMe) or a cyclic dipeptide of L-serine [c-(Ser)2] to yield novel polyetherurethanes containing dipeptide segments. The relationship between the surface morphology and the biomedical properties of the film of the novel polyetherurethanes was investigated. The surface of PU(PTMG,Z-Ser-Ser-OMe,MDI) film was smooth, but fibrous structures were developed in the bulk of the film with increasing molecular weight of the PTMG segment. The antithrombogenicity of the film containing the low molecular weight PTMG segment was better than that of the usual polyetherurethane film without the dipeptide segments. The partial hydrolysis of the ester groups involved in the dipeptide segment improved the antithrombogenicity. In the surface and the bulk of PU[PTMG,c-(Ser)2,MDI] film, spherulite structures were developed when the molecular weight of the PTMG segment was high, while single crystals with a length of 3-4 microns were produced when the molecular weight of the PTMG segment was low. The antithrombogenicity of the film containing the high molecular weight PTMG segment was better than that of the usual polyetherurethane film without the dipeptide segments. PU(PTMG/PEG,Z-Ser-Ser-OMe,MDI) film and PU[PTMG/PEG,c-(Ser)2,MDI] film were permeated by uraemic toxins. The permeation was accelerated with increasing water content of the film and decreasing molecular weight of the solute. The oxygen permeability of the film of the polyetherurethane containing the linear or cyclic dipeptide segments was greater than that of polyetherurethane film which does not contain the dipeptide segments.