The first case report of trypanosomiasis caused by Trypanosoma evansi in Uruguay.

Trypanosoma evansi, the causal agent of Surra, is a salivarian African trypanosoma introduced in America during the 15th century. In this study we report the first case of African trypanosomiasis in Uruguay. We describe clinical signs and the evolution of the disease on an Uruguayan Cimarron dog, as well as the isolation and molecular characterization of the Trypanosoma evansi reported strain. This constitutes the first case of Surra in Uruguay, showing the expansion of the parasite to the south of the American continent. Future work is needed to identify the vector and possible reservoirs in order to avoid the spread of the disease. The epidemiological relevance of the findings are discussed.

Evaluation of an enterocin AS-48 enriched bioactive powder obtained by spray drying.

Enterocin AS-48 is a cationic cyclic bacteriocin produced by Enterococcus faecalis with broad bactericidal activity. Currently we are assaying the efficacy of AS-48 as biopreservative in foods. In this work we have applied the spray drying process to different AS-48 liquid samples to obtain active dried preparations. We have also assayed different methods, heat, UV irradiation and filtration, to inactivate/remove the AS-48 producer cells from the samples. Best results were obtained for the sample from CM-25 cation exchange, for which it was also possible to completely eliminate/inactivate the producer cells by heat or UV irradiation without loss of activity. When added at 0.016% or 5% to Brain Heart Infusion broth or to skim milk, respectively, the AS-48 powder caused early and complete inactivation of Listeria monocytogenes. A partial inhibition of Staphylococcus aureus was achieved in broth and in skim milk supplemented with 2.5% and 10% AS-48 powder, respectively.

IMMUNEPOTENT CRP (bovine dialyzable leukocyte extract) adjuvant immunotherapy: a phase I study in non-small cell lung cancer patients.

BACKGROUND: IMMUNEPOTENT CRP is a mixture of low molecular weight substances, some of which have been shown to be capable of modifying the immune response. We evaluated the response and adjuvant effect of IMMUNEPOTENT CRP on non-small cell lung cancer (NSCLC) patients in a phase I clinical trial. METHODS: Twenty-four NSCLC patients were included in the study and divided into two groups. Group 1 received a conventional treatment of 5400 cGy external radiotherapy in 28 fractions and chemotherapy consisting of intravenous cisplatin (40 mg/m(2)) delivered weekly for 6 weeks. Group 2 received the conventional treatment plus IMMUNEPOTENT CRP (5 U) administered daily. We performed clinical evaluation by CT scan and radiography analysis, and determined the quality of life of the patients with the Karnofsky performance scale. A complete blood count (red and white blood cell tests), including flow cytometry analysis, blood work (alkaline phosphatase test) and a delayed-type hypersensitivity (DTH) skin test for PPD, Varidase and Candida were performed. RESULTS: The administration of IMMUNEPOTENT CRP induced immunomodulatory activity (increasing the total leukocytes and T-lymphocyte subpopulations CD4(+), CD8(+), CD16(+) and CD56(+), and maintaining DHT) and increased the quality of the patients' lives, suggesting immunologic protection against chemotherapeutic side-effects in NSCLC patients. DISCUSSION: Our results suggest the possibility of using IMMUNEPOTENT CRP alongside radiation and chemotherapy for maintaining the immune system and increasing the quality of life of the patients.

Bovine dialyzable leukocyte extract modulates AP-1 DNA-binding activity and nuclear transcription factor expression in MCF-7 breast cancer cells.

BACKGROUND: We have previously demonstrated that bovine dialyzable leukocyte extract (bDLE) induces death through an apoptosis mechanism in MCF-7 breast cancer cells. Depending on the cell type and stimulus, activating protein-1 (AP-1) has been shown to regulate cell proliferation and differentiation, the stress response, apoptosis and survival. It remains unknown whether AP-1 and other transcription factors are mechanisms by which bDLE induces cell death. METHODS: To determine whether bDLE modulates the AP-1 DNA binding and gene expression, MCF-7 breast cancer cells were treated with bDLE (0, 1, 5, 10 U) for 72 h and evaluated by electrophoretic mobility shift assay, reverse transcriptase-polymerase chain reaction and Western blot assays. RESULTS: bDLE induced inhibition of cell growth, suppressed the AP-1 DNA-binding activity, decreased c-Jun protein expression and modulated NFATx, NFATc, NFkappaB, c-Jun and c-Fos transcription factor gene expression in MCF-7 breast cancer cells. DISCUSSION: The present data indicate that bDLE can block the AP-1 DNA-binding activity and expression of several transcriptions factors in breast cancer cells, which will have great potential in improving cancer therapy.

Bovine dialyzable leukocyte extract modulates cytokines and nitric oxide production in lipopolysaccharide-stimulated human blood cells.

BACKGROUND: In the current study, we determined whether bovine dialyzable leukocyte extract (bDLE) modulates lipopolysaccharide (LPS)-induced nitric oxide and cytokine overproduction. METHODS: Human whole blood cells were treated with LPS (50 ng) + bDLE (1 U). RESULTS: The bDLE treatment decreased nitric oxide as well as TNF-alpha, IL-6 and IL-10 (P <0.01) cytokine production. In addition, it decreased TNF-alpha, IL-1beta and IL-6 mRNA expression and suppressed IL-10 and IL-12p40 mRNA expression, but did not modulate IL-8 mRNA expression in LPS-stimulated human blood cells. DISCUSSION: Our results suggest that bDLE may effectively modulate the fatal symptoms of hypotensive shock associated with endotoxin (LPS)-induced nitric oxide and cytokine production, and this may offer therapeutic potential for the treatment of endotoxic shock.

Correlation of base consumption with the degree of hydrolysis in enzymic protein hydrolysis.

It is fairly easy to control the enzymic hydrolysis of proteins in alkaline conditions by measuring the base consumption required to keep the pH constant in the reactor. Unfortunately, however, base consumption is not related in any simple way to the degree of hydrolysis reached at any given moment and to establish this relationship it is essential to find out the mean pK of the alpha-amino groups released during the hydrolytic process. We have shown here that the correct mean pK value varies according to the pH of the working conditions and that the relationship between these values may depend upon the kind of protein and protease used. We have put forward a method for determining this relationship experimentally by using a given protein-protease system, consisting of an alkaline titration of the raw protein and when partially hydrolysed. We have tested the results predicted by our theoretical model by applying it to the hydrolysis of whey proteins with a bacterial protease from Bacillus licheniformis at 50 degrees C, pH 8.0. This model can easily be applied to any hydrolytic process involving the appearance of functional groups that are partially protonizable under the working conditions in question in order to follow the kinetics of the reaction via the consumption of the neutralizing agent required to keep pH constant.

Role and behaviour of the hydrophobic conditions in bacterial adhesion to incurrent siphon in a bivalve mollusc.

Surface hydrophobicity is a widely distributed characteristic among human bacterial pathogens playing an important role in microbes retention by the incurrent siphon of a marine bivalve. Feeding retention experiments with the bivalve Mesodesma donacium was done with hydrophobic strains alone (Staphylococcus aureus, Salmonella paratyphi, Vibrio cholerae) or with mixed cultures using a hydrophilic strain (Aeromonas hydrophila). Results showed that hydrophobic bacteria are retained in greater numbers than hydrophilic bacteria. This difference is statistically significant. Hydrophobic strains also survive longer than hydrophilic ones in sea water. Surface hydrophobicity is to be considered as a factor influencing concentration of hydrophobic pathogens by filter feeding molluscs.

Partition coefficients of alpha-amylase in aqueous two-phase systems PEG + MgSO4.7H2O + H2O at 298 K.

Partition coefficients of alpha-amylase have been determined in a polyethylene glycol (average molecular mass 8000)/MgSO4.7H2O aqueous two-phase system at 298 K and the influence of polymer, salt and initial enzyme concentration on partition was investigated. Correlations are proposed which relates the partition coefficient to the initial enzyme concentration and the concentration difference between phases of polymer and salt. The free volume change, related to the densities of the separate phases, has a direct dependence with such polymer and salt concentration differences, respectively, and is then used to facilitate future estimations. Thus, the partition coefficient is a function of this physical parameter and the initial enzyme concentration employed (1.25, 2.50 and 5.00 g dm-3).

Enzymatic hydrolysis of whey proteins: I. Kinetic models.

We have studied the enzymatic hydrolysis of whey proteins at pH 8 and50 degrees C with two proteases of bacterial origin, MKC Protease 660 L, and one of animal origin, PEM 2500 S. Our results show that a greater degree of hydrolysis is achieved under the same experimental conditions with the bacterial proteases than with the animal one. In our interpretation of the results we propose a mechanism in which the hydrolytic reaction is a zero-order one for the substrate, and the enzyme denaturalizes simultaneously via a second-order kinetic process due to free enzyme attacking enzyme bound to the substrate. Our results also indicate that there is an irreversible serine-protease inhibitor in whey proteins. (c) 1994 John Wiley & Sons, Inc.

Enzymatic hydrolysis of whey proteins. II. Molecular-weight range.

Using high-pressure liquid chromatography we studied the distribution of molecular weights in whey-protein hydrolysates using the following commercially obtained proteases: Alcalasa 0.6 L and Protease 660 L, both bacterial in origin, and PEM 2500 S, of animal origin. In each of the systems, the range of molecular weights in the hydrolysate depended solely on the degree of hydrolysis (DH) achieved. For DH >/= 20, between 65% and 95% of the hydrolysate is made up of peptides with a molecular weight of less than 1,000 Da. (c) 1994 John Wiley & Sons, Inc.

[Overview of the epidemiology of Chagas' disease in Chile]. / Panorama general de la epidemiología de la enfermedad de Chagas en Chile.

Chile is a long and narrow country located in the south western coast of South America. Chagas' disease exists in the seven first (18 degrees 30'-34 degrees 36' South lat.) of the total of thirteen administrative regions of the country. In the 1982-1990 period a series of studies considering different epidemiological aspects of this parasitic zoonosis has been carried out with the following results: 5,601 rural of periurban dwellings were surveyed for the presence of Triatoma infestans (the most important and almost exclusive vector of Trypanosoma cruzi in Chile). 37.4% of the dwellings were infested according to the inhabitants and 29.4% were found infested according to the presence of tracks or insects captured. In 659 (17.2%) out of 3,822 T. infestans captured and examined T. cruzi was found in their abdominal contents. The most common sources of T. infestans feeding were mammals (89.0%), including man, and birds (9.5%). An indirect hemagglutination test (IHAT) for Chagas' disease, a very sensitive and specific reaction, was performed to 5,050 domestic mammals, resulting positive 7.9% of cats, 7.0% of dogs, 7.0% of goats, 4.9% of sheep and 4.1% of rabbits. 2,579 (16.9%) out of 15,418 persons were positive for the IAHT for Chagas' disease. The rates of infection were rather similar in males (17.5%) and females (16.2%) with an increase in infection rates in accordance with increase of age of individuals. The overall frequency of ECG abnormalities in positive IHAT persons was 18.7% against 8.8% in those with negative IHAT, whereas ECG abnormalities considered as suggestive of a chagasic etiology were 6.8% and 2.2% respectively. The esophageal motility in 311 persons with a positive IHAT and in 150 with a negative IHAT was found altered in 42.8% and 18.7% respectively. In the corresponding urban sectors of the 7 regions mentioned 2.7% of blood donors, 2.3% of delivering mothers, 2.6% of newborns and 0.6% of school children had positive IHAT. 646 chagasic women and 709 non-chagasic women in their reproductive span of life, and the products of the pregnancies that they had in a 6-year period were followed-up. No significant differences were found neither in the number nor in the evolution of pregnancies in both groups of mothers. Xenodiagnosis of children from chagasic mothers resulted positive in 6.3-8.9%, showing the transmission of T. cruzi by the placental route. Recently, 3 cases of congenital Chagas' disease of second generation have been demonstrated.(ABSTRACT TRUNCATED AT 400 WORDS)

Calidad bacteriológica del agua en playas de Valparaíso y Viña del Mar: III. Contaminación ambiental / Bacteriological quality of water in beaches of Valparaíso and Viña del Mar: III. Ambiental contamination

Se determina la contaminación microbiológica del agua de mar, en las playas más importantes de la Bahía de Valparaíso utilizando indicadores bacterianos. Coliformes totales y coliformes fecales se utilizaron como indicadores siguiendo los procedimientos de "Standard Methods". Se realiza una comparación de las técnicas de enumeración entre la fermentación de tubos múltiples y la técnica de filtración por membrana. Los resultados son expresados como media geométricas, para cada una de las estaciones estudiadas. Finalmente, se discuten los resultados obtenidos y la significación que podría tener en relación a la salud pública