Secondary Metabolites Isolated from Chilean Marine Algae: A Review

Chile is in the extreme southwestern part of America, and it has an extreme length, of approximately 4300 km that increases to 8000 km considering the Chilean Antarctic Territory. Despite the large extent of its coastal territory and the diversity of geographic environments and climates associated with Chilean coasts, the research on marine resources in Chile has been rather scarce. From marine organisms found in Chilean coastal waters, algae have been the most studied, since they contain a wide range of interesting secondary metabolites that have some structural traits that make them unique and uncharacteristic. Thus, a wide structural variety of natural products including terpenoids (monoterpenes, sesquiterpenes, diterpenes, and meroterpenoids), furanones, and C₁₅-acetogenins have been isolated and identified. This review describes the existing literature on bioprospecting and exploration of secondary metabolites from Chilean coasts.     

The accreditation system for colleges of veterinary medicine in Mexico and a comparison with the AVMA system

This article reviews the evolution of veterinary medicine in Mexico in order to explain the foundation of the National Council for Veterinary Medicine Education (CONEVET). This institution performs college accreditation and professional certification procedures in the country. The accreditation process for colleges of veterinary medicine in Mexico is described, and the results obtained to this point are presented. A comparative analysis of veterinary education in Mexico and the United States is also presented. The veterinary college accreditation processes of the two countries are compared and their differences analyzed.     

Lipoid pneumonia in a rough collie dog

The incidence of lipoid pneumonia in dogs is not known and confirmed cases do not appear to have been reported. Three forms of lipoid pneumonia are recognised in mammalian species; exogenous lipoid pneumonia (ELP), endogenous lipoid pneumonia (EnLP), and post-obstructive endogenous lipoid pneumonia (PEnLP). All forms share similar microscopic characteristics of fat accumulation in the cytoplasm of alveolar macrophages and are otherwise clinically indistinct from other forms of pneumonia. A case of lipoid pneumonia in a seven-year-old rough collie dog which was presented with recurrent bronchopneumonia over several months is reported here. Diagnosis was made from biopsy of resected lung tissue and from detection of fat-containing vacuoles in macrophages obtained by bronchoalveolar lavage. ELP could not be differentiated from PEnLP in this dog, but a complete recovery followed removal of the affected right accessory and caudal lung lobes.     

Serum immunoglobulin G concentration in Southern elephant seal, Mirounga leonina (Linnaeus, 1758), from Elephant Island (Antarctica): sexual and adrenal steroid hormones effects

Serum immunoglobulin G (IgG; indirect enzyme-linked immunosorbent assay), as well as sexual and adrenal steroid hormones' concentrations (radioimmunoassay) were determined in 63 (male and female) Southern elephant seals (Mirounga leonine) at different developmental stages (weaned pups, juveniles and adults). In females, IgG values (mean+/-S.D.) were higher (P<0.05) in adults (15.9+/-6.5mg ml(-1)) than in juveniles (7.9+/-4.0mg ml(-1)), but similar to weaned pups (12.0+/-5.0mg ml(-1)). Estrogen concentration was higher (P<0.05) in adults than in the weaned pups. In females, a significant (P<0.05) correlation (R=0.4) between serum IgG level and progesterone concentration was observed. In males, testosterone concentration was higher (P<0.05) in adults than in the juveniles and weaned pups. Aldosterone and cortisol concentrations were higher (P<0.05) in weaned pups (1056.0+/-643.1pmol 1(-1) and 272.7+/-110.0 nmol 1(-1), respectively) than in the juveniles (638.6+/-579.7pmol1(-1) and 152.9+/-97.3nmol 1(-1), respectively) and adults (386.5+/-209.1pmol (-1) and 145.7+/-67.3nmol 1(-1), respectively). These findings indicate that weaned pups are subjected to a higher natural stressful condition in the field. Despite this, humoral immunity, measured through IgG concentration, is not impaired in weaned pups.     

Risk factors for canine echinococcosis in an endemic area of Peru

An epidemiological study was conducted in a highland rural community in Peru to determine risk factors for canine echinococcosis caused by Echinococcus granulosus. Dogs were diagnosed using a coproantigen enzyme-linked immunosorbent assay (ELISA). Dog owners were interviewed prior to stool collection and asked for attitudes, practices and beliefs likely to be associated with local patterns of E. granulosus transmission. Univariate and multivariate analysis were used to determine odds ratios (OR) and their 95% confidence intervals (CI). The main risk factors found to be significantly associated with canine echinococcosis by univariate analysis were dog age (3-25 months) (OR, 5.14; CI, 1.7-15.7), female sex (OR, 4.3; CI, 1.4-13.3) and having been fed hydatid infected offal (OR, 2.9; 95% CI, 1.0-8.6). There was complete lack of knowledge about echinococcosis transmission. In addition to periodic dog treatment, control programs need to emphasize education of the human population to increase knowledge of parasite transmission and to change human practices associated with high rates of infection.     

Epizootic cutaneous pythiosis in beef calves

Enzootic bovine granulomatosis (EBG) is a disease that affects beef calves in the flooded Savanna regions of Venezuela. Although Pythium insidiosum was originally the suspected etiologic agent, nothing was done to demonstrate its presence in the infected animals. The objective of this study was to investigate the etiologic agent causing cutaneous lesions in a group of 63 calves diagnosed with EBG. The collected samples were analyzed by histopathology, immunohistochemistry, serology, and mycological techniques. The clinical manifestations of BEG included ulcerated and swollen granulomatous lesions on the limbs of young calves. Histopathological studies revealed an eosinophilic inflammatory reaction with neutrophils, giant cells and branching hyphae with the Splendore-Hoeppli phenomenon. Immunofluorescence analysis identified the branching hyphae as elements of the fungal-like organism P. insidiosum. Wet mounts in 10% KOH revealed hyaline slender branching hyaline coenocytic hyphae, but cultures from those samples were negative. Anti-P. insidiosum immunoglobulins were also demonstrated in the collected sera of the affected bovines using latex agglutination, immunodiffusion, ELISA, and Western Blot. The histopathological, immunohistochemical, and serological tests showed for the first time that P. insidiosum could be involved in epizootic bovine pythiosis.     

Resistance to <Emphasis Type="Italic">Penicillium</Emphasis><Emphasis Type="Italic">hirsutum</Emphasis> Dierckx in garlic accessions

Among the factors affecting the quality and yield of garlic production, blue mold caused by -- Penicillium spp. -- is responsible for economical losses in many countries. Allicin, present in garlic bulbs, has been suggested as having antifungal activity against some Penicillium species. This study was conducted to evaluate the response of garlic accessions against Penicillium hirsutum infection and to compare this response with bulb allicin content. Twelve garlic accessions were inoculated with P. hirsutum, and assayed in greenhouse and growth chamber experiments. Plant growth parameters and the fungal production of conidia were evaluated. Significant differences were found among the accessions. Accessions Castaño and Morado were most resistant whereas AR-I-125 and Fuego were always severely affected by the disease. A low correlation was found (r = 0.17) between allicin content and tolerance, indicating that allicin is not the main factor involved in the resistance against P. hirsutum.     

Molecular analysis suggests that recent <Emphasis Type="Italic">Citrus tristeza virus</Emphasis> outbreaks in Italy were originated by at least two independent introductions

Citrus tristeza virus (CTV) is the causal agent of the most important virus disease of citrus. Numerous CTV isolates differing in biological and molecular characteristics have been reported worldwide. Recently, CTV was detected in Italy in several citrus crops from three separate areas: (1) Cassibile, province of Syracuse; (2) Massafra, province of Taranto; and (3) Belpasso, province of Catania. CTV isolates from Massafra and Cassibile were mild, whereas isolates from Belpasso induced severe symptoms. To study the genetic variation of CTV populations of these areas, 150 samples per area were examined by single strand conformation polymorphism (SSCP) and nucleotide sequence analysis of CTV gene p20. All isolates from the same area showed the same SSCP pattern whereas for each area a different SSCP pattern was obtained. The Massafra and the Cassibile isolates had a nucleotide identity higher than 99% with a mild isolate from Spain and about 92% with the Belpasso isolates, which were similar (identity higher than 99%) to severe isolates from California and Japan. These results suggest at least two independent introductions of CTV in Italy, probably by import of CTV-infected budwoods. Within each area, the virus population was homogeneous suggesting diffusion of CTV by aphid transmission. The GenBank accession numbers of the sequences reported in this paper are: AY262000, AY263360 and AY263361 corresponding to gene p20 of CTV isolates from Massafra, Cassibile and Belpasso (Italy), respectively.     

Neurophysiological activity and toxicity of pyrethroids derived by addition of methylene,sulfur or oxygen to the chrysanthemate 2-methyl-1-propenyl substituent

Conversion of chrysanthemates to their cyclopropane, episulfide, and epoxide derivatives by addition of methylene, sulfur, or oxygen, respectively, to the 2-methyl-1-propenyl double bond yields products generally of reduced toxicity but enhanced neurophysiological activity and photostability. The reduced toxicity is established with cis-cyphenothrin derivatives administered intracerebrally to mice and topically to house flies and with cis-phenothrin derivatives applied topically to American cockroaches and house flies, even in the presence of piperonyl butoxide for the house flies. In contrast, cyclopropane, episulfide, and epoxide derivatives of phenothrin are more potent than the parent compound in eliciting repetitive firing following stimulation of a cercal sensory nerve of the American cockroach in vitro. The individual 1′R and 1′S isomers of epoxides derived from (1R,cis,αS)cyphenothrin, (1R,cis)phenothrin, and (1R,trans)tetramethrin differ in potency by up to 20-fold for insecticidal activity, >30-fold for intracerebral toxicity to mice, and ～100,000-fold in the cercal sensory nerve assay. In each case the epoxide isomer of higher R_f is more potent than that of lower R_f when derived from a trans-chrysanthemate and vice versa from a cis-chrysanthemate.