PubMed Health⌕ Search

Biomedical subjects

J L Rodríguez

Publications and source records attributed to J L Rodríguez.

At least 19 recordsLinked to original sources
PubMed1998

Field studies and cost-effectiveness analysis of vaccination with Gavac against the cattle tick Boophilus microplus.

The control of tick infestations and the transmission of tick-borne diseases remains a challenge for the cattle industry in tropical and subtropical areas of the world. Traditional control methods have been only partially successful and the parasites continue to result in significant losses for the cattle industry. Recently, vaccines containing the recombinant Boophilus microplus gut antigen Bm86 have been developed. These vaccines have been shown to control tick infestations in the field. However, extensive field studies investigating the efficacy and cost-effectiveness of vaccination have not been reported and are needed to appraise the effect of this new approach for tick control. Here is reported the results of the application of Gavac in a field trial including more than 260,000 animals in Cuba. In this study the correlation between the antibody response to vaccination and the effect on ticks fertility is determined. Physiological status of the animals was found to affect the primary response to vaccination but not the antibody titers after revaccination. A cost-effectiveness analysis showed a 60% reduction in the number acaricide treatments, together with the control of tick infestations and transmission of babesiosis, which resulted in savings of $23.4 animal-1 year-1. These results clearly demonstrate the advantage of vaccination and support the application of Gavac for tick control.

Animals↗
PubMed1998

A pathological and immunohistochemical study of goat kids undergoing septicaemic disease caused by Mycoplasma capricolum subsp. capricolum, Mycoplasma mycoides subsp. capri and Mycoplasma mycoides subsp. mycoides (large colony type).

This paper studies the pathological and immunohistochemical findings in 12 kids experimentally infected with Mycoplasma capricolum subsp. capricolum (Mcc), M. mycoides subsp. capri (Mmc) and M. mycoides subsp. mycoides (large colony type), (MmmLC). For the demonstration of Mcc, Mmc and MmmLC antigens an immunoperoxidase technique based on the labelled streptavidin biotin method was used in the 12 kids inoculated with mycoplasmas and the three control kids inoculated with mycoplasma medium. All 12 kids, inoculated by different routes, developed subcutaneous swelling at the point of inoculation and terminated in fatal septicaemia from 1 to 5 days post inoculation. The histopathological findings consisted of cellulitis at the point of inoculation, acute diffuse interstitial pneumonia, arthritis and multifocal necrotic purulent splenitis in some kids. The Mcc, Mmc and MmmLC antigens were detected immunohistochemically in all kids with specific punctiform labelling inside the cytoplasm of the leucocytes or extracellularly at the inoculation point, respiratory airways, spleen, liver, joints, tonsils and lymph nodes. The results obtained in this study showed that the inoculation of these mycoplasmas by parenteral routes caused mycoplasmaemia. Moreover, the immunohistochemical results appear fully to confirm that the mycoplasmas were the cause of the death of the kids because of a septicaemic state.

Animals↗
PubMed1997

Relationship between microstructure and ductility of investment cast ASTM F-75 implant alloy.

Hip replacement implants fabricated using the ASTM F-75 alloy sometimes fail in a sudden catastrophic way. In general, fractures start at microstructural defects subjected to stress-corrosion under chemical attack by body fluids. In this paper the results of a study on the effect of casting parameters on the microstructure of ASTM F-75 are presented. The preheating mold temperature and the liquid temperature were varied between 900 and 1000 degrees C, and 1410 and 1470 degrees C, respectively. Optimum static strength and ductility were obtained when shrinkage microporosity and the volume fraction of M23C6 "eutectic" carbides precipitated at grain boundaries were minimized by increasing the preheating mold temperature to 1000 degrees C and by using intermediate pouring temperatures of 1455 degrees C. Under these casting conditions, however, the solidification rates are low, leading to large grain sizes, which, in turn, reduce the strength of the material under dynamic loading conditions. The volume fraction of the M23C6 "blocky" carbides appears to be independent of the casting conditions; however, their size and spatial distributions determine the strength of the as-cast alloys.

Alloys↗
PubMed1997

Testing topographic differences between event related brain potentials by using non-parametric combinations of permutation tests.

MANOVA and repeated measures ANOVA approaches have provided evidence of a number of limitations in several event-related potential (ERP) studies due to violations of their statistical assumptions and the typically moderate size of the available sample. Alternative, computer-intensive methods based on permutation principles have recently been developed. Up to now this methodology has focused mostly on magnitude differences between scalp distributions as measured by t statistics. In this paper the scope of permutation techniques in ERP analysis was widened. A new statistic (D statistic) is introduced to compare the shapes of scalp distributions of ERPs. Additionally a general non-parametric combinatory technique is introduced to evaluate, by means of multivariate permutation tests, several time points and/or recording sites in ERP data. The methodology described here was used to test if two ERP components elicited during word-pair matching tasks to semantic or phonological incongruences had different scalp distributions.

Adolescent↗
PubMed1997

Association of cilia-associated respiratory (CAR) bacillus with natural chronic tracheitis in goats.

A histological, histochemical and immunohistological study of the respiratory tract of 83 slaughtered goats (50 adults and 33 kids) is described. Cilia-associated respiratory (CAR) bacillus was detected by means of the Warthin Starry method in the tracheal epithelium of seven (21.2%) of the kids and 16 (32%) of the adult goats. A chronic diffuse tracheitis characterized by mixed lymphocyte and plasma-cell infiltration was found in all seven kids and in 17 adults, including the 16 infected with the CAR bacillus. Although not proved, it is possible that the CAR bacillus caused the chronic tracheitis. Immunohistochemical results suggested that the caprine CAR bacillus was closely related to the rabbit CAR bacillus.

Animals↗
PubMed1997

Identification of the novel antimicrobial fatty acid (5Z,9Z)-14-methyl-5,9-pentadecadienoic acid in Eunicea succinea.

The phospholipid fatty acid composition of Eunicea succinea was investigated, and the novel (5Z,9Z)-14-methyl-5,9-pentadecadienoic acid was identified. Structural characterization was accomplished by means of mass spectrometry of its pyrrolidide derivative, NMR, FT1R, and total synthesis. Other interesting phospholipid fatty acids in E. succinea were the tetracosapolyenoic acids 6,9,12,15,18,21-tetracosahexaenoic acid (24:6) and 6,9,12,15,18-tetracosapentaenoic acids (24:5). The title compound was particularly active against Gram-positive bacteria such as Staphylococcus aureus (MIC 0.24 mumol/mL) and Streptococcus faecalis (MIC 0.16 mumol/ mL).

Animals↗
PubMed1997

Inhibition of Listeria monocytogenes by enterocin 4 during the manufacture and ripening of Manchego cheese.

The inhibitory effect of enterocin 4, a bacteriocin produced by Enterococcus faecalis INIA 4, on Listeria monocytogenes strains Ohio and Scott A during the manufacture and ripening of Manchego cheese was investigated. Raw ewe's milk was inoculated with ca 10(5) cfu ml-1 of L. monocytogenes and with 1% of a commercial lactic starter, 1% of an Ent. faecalis INIA 4 culture, or 1% of each culture. Manchego cheeses were manufactured according to usual procedures. Listeria monocytogenes Ohio counts decreased by 3 log units after 8 h and by 6 log units after 7 d in cheese made from milk inoculated with Ent. faecalis INIA 4 or with both cultures, whereas no inhibition was recorded after 60 d in cheese made from milk inoculated with commercial lactic starter. Listeria monocytogenes Scott A was not inhibited by enterocin 4 during cheese manufacture, but decreases of 1 log unit after 7 d and of 2 log units after 60 d were achieved in cheese made from milk inoculated with both commercial lactic starter and Ent. faecalis INIA 4.

Bacteriocins↗
PubMed1997

Bacteria associated with enzootic pneumonia in goats.

A histological and microbiological study of lung samples from 83 slaughtered goats (33 kids and 50 adults) drawn from a flock with a history of pleuropneumonia caused by mycoplasmas of the M. mycoides group was carried out. A total of 82% (27/33) of kids and 36% (18/50) of adult goats presented pulmonary lesions characteristic of enzootic pneumonia: lesions took the form of bronchointerstitial pneumonia with peribronchial and peribronchiolar proliferation of lymphocytes. Microbiological analysis confirmed a range of mycoplasma species, including Mycoplasma mycoides ssp. mycoides Large Colony (MmmlC) (3.70%; 1/27), Mycoplasma mycoides ssp. capri (Mmc) (7.40%; 2/27), Mycoplasma putrefaciens (22.2%; 6/27), Mycoplasma arginini (3.70%; 1/27) and Mycoplasma sp. (7.40%; 2/ 27), as well as Pasteurella multocida (14.8%; 4/27), associated with enzootic pneumonia lesions in younger animals, whereas Mycoplasma sp. was associated with enzootic pneumonia in adult goats (22.0%; 4/18). Cilia-associated respiratory (CAR) bacillus found by histochemical examination was associated with enzootic pneumonia in kids (25.9%; 7/27) and goats (44.4%; 8/18), being the first description of this bacterium in adult goats.

Animals↗
PubMed1997

Natural cilia-associated respiratory bacillus infection in rabbits used for elaboration of hyperimmune serum against Mycoplasma sp.

Cilia-associated respiratory (CAR) bacillus was identified in lung lesions of rabbits used for elaboration of hyperimmune serum against Mycoplasma mycoides ssp. capri (Mmc). Numerous Warthin Starry (WS) positive filamentous bacteria aligned perpendicularly to the surface of bronchial epithelial lining were observed. Immunoperoxidase staining of these bacteria was detected using a serum anti-rabbit CAR bacillus. Ultrastructural morphology corresponds to that of CAR bacilli previously reported in rabbits. The desirability of monitoring laboratory rabbits for CAR bacillus infection as part of the health programme is reinforced, especially in rabbits used for raising sera against respiratory pathogens of animal species in which CAR bacillus infection has been described. This is the first report of natural CAR bacillus infection in rabbits in Europe.

Animals↗
PubMed1997

Tracheal malformation in a bicephalic Honduran milk snake (Lampropeltis hondurensis) and subsequent fatal Salmonella arizonae infection.

A bicephalic Honduran milk snake (Lampropeltis hondurensis) with tracheal duplication and malformation and Salmonella arizonae infection is described. There were atypically wide collapsed tracheal rings with necrotizing tracheitis and abundant necrotic epithelial debris and inflammatory cells obstructing the lumen in one of the duplicate tracheae. Salmonella arizonae was cultured from the malformed duplicate trachea and was considered to be the etiologic agent causing necrosis.

Animals↗
PubMed1996

Postcolumn excitation of aflatoxins using cyclodextrins in liquid chromatography for food analysis.

Measurement of fluorescence increase was used for the comparative quantification of the effect that several cyclodextrins (alpha-, beta-, heptakis-2,6-beta-omicron-dimethyl- and gamma-) produce on the fluorescent response of aflatoxins B1 and G1. This constitutes a new chromatographic method with stability of the mobile phase, and shows general improvements in the chromatographic conditions with respect to other methods (especially those using an iodine reservoir as a postcolumn reactor). A C18-type column was used, with methanol-water (60:40, v/v) as the mobile phase. The excitation phase of the natural fluorescence of aflatoxins, a 10(-2) M solution of each cyclodextrin, was introduced postcolumn. The determination of the elution order aflatoxin G2 > G1 > B2 > B1 was performed for each phase in less than 15 min. As expected using an aqueous-alcoholic medium, an increase in the fluorescence response of aflatoxins with an unsaturated furanic ring was found to occur with all the cyclodextrins studied, except gamma-cyclodextrin. The observed increase was larger for heptakis-2,6-beta-omicron-dimethyl- than for beta-cyclodextrin (to our knowledge, the only cyclodextrin previously described in the literature to serve for the determination of aflatoxins). The difference is of the order of 70.1-fold in the case of aflatoxin G1 and 45.2-fold in the case of aflatoxin B1. The detection limit in the mobile phase used was determined (for aflatoxin B1) for beta-cyclodextrin and 2,6-beta-omicron-dimethylcyclodextrin (signal-to-noise ratio 1:3) to be 4 and 9 mg 1(-1), respectively.

Aflatoxin B1↗
PubMed1996

A pathological and immunohistochemical study of caprine pleuropneumonia induced by subspecies of Mycoplasma mycoides.

In a population of 700 goats, 150 died; of these, 29 were necropsied. Ten of the 29 goats had pleuropneumonia. Mycoplasma mycoides subsp. mycoides (Large Colony) (MmmLC), Mycoplasma mycoides subsp. capri (Mmc), and Pasteurella multocida were isolated from five of the pleuropneumonic goats. Gross and microscopical lesions were typical of caprine pleuropneumonia (CPP), with bronchopneumonia, fibrinopurulent or fibrinonecrotic pleuropneumonia and dilatation of the interlobular septa and pleura. Immunohistochemical examination with antisera against MmmLC and Mmc showed mycoplasma antigens in all 10 goats with CPP. In all cases, both MmmLC and Mmc antigens were detected together. Mycoplasma antigens were present in the lumina of the airways and alveoli, mainly inside the cytoplasm of neutrophils and macrophages, but extracellular antigen was demonstrated in areas of necrosis. Pasteurella antigens were detected in four of the 10 animals with CPP. From the histological, immunohistochemical and microbiological results it was concluded that the two mycoplasmas, acting together, caused the pleuropneumonia, with P. multocida playing a subsidiary synergistic role.

Animals↗
PubMed1996

Respiratory and digestive lesions caused by Salmonella arizonae in two snakes.

Cases of diphtheritic necrotizing gastritis in a Rosy Boa (Lichanura trivirgata) and of necrotizing tracheitis in a double-headed Kingsnake (Lampropeltis hondurensis), both associated with Salmonella arizonae, are described. An immunoperoxidase technique indicated that S. arizonae played a role in the causation of the lesions. In addition, the study showed the value of the technique for the detection of S. arizonae in the tissues of infected snakes.

Animals↗