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Biomedical subjects

L Dominguez

Publications and source records attributed to L Dominguez.

At least 37 records · Page 2Linked to original sources
PubMed1996

Spacer oligonucleotide typing of Mycobacterium bovis strains from cattle and other animals: a tool for studying epidemiology of tuberculosis.

The spacer oligonucleotide typing (spoligotyping) method was evaluated for its ability to differentiate Mycobacterium bovis strains. This method detects the presence or absence of spacers of the direct repeat locus of the M. bovis genome. The spacers in the direct repeat locus are amplified by PCR and are detected by hybridization of the biotin-labelled PCR product with a membrane containing oligonucleotides derived from spacer sequences that have previously been bound to a membrane. One hundred eighty-two M. bovis isolates from domestic animals (cattle, goat, sheep, and cats) and wild animals (deer and wild boar) were spoligotyped, and the results were compared with those obtained by IS6110 restriction fragment length polymorphism analysis. Two rather homogeneous clusters of isolates containing 20 and 4 types, respectively, were identified by spoligotyping. The first cluster included isolates from cattle, cats, and feral animals. By spoligotyping, isolates from the Spanish wild boar and deer had the same pattern as some bovine isolates, suggesting transmission between these animals and cattle and highlighting the importance of the study of these reservoirs. The second cluster included all the caprine and ovine isolates. Within each cluster, the patterns of the different strains differed only slightly, suggesting that the spoligotypes may be characteristic of strains from particular animal species. Spoligotyping proved to be useful for studying the epidemiology of bovine M. bovis isolates, especially of those isolates containing only a single copy of IS6110. In view of our results, we suggest fingerprinting all M. bovis strains by the spoligotyping method initially and then by IS6110 restriction fragment length polymorphism typing of the strains belonging to the most common spoligotypes.

Animals↗
PubMed1996

Changes in bone mineral density, growth velocity and renal function of prepubertal uremic children during growth hormone treatment.

Thirteen prepubertal children with a mean chronological age of 6.7 +/- 3.4 years and severe chronic renal failure (mean glomerular filtration rate of 20.8 +/- 17.7 ml/min/1.73 m2) were studied. Patients received recombinant human growth hormone (rhGH) at a dose of 1 IU/kg/week given subcutaneously on a daily basis for 12 months. Mean growth rates of our patients increased significantly from a baseline level of 4.3 +/- 2.1 to 9.1 +/- 2.0 cm/year at 12 months of rhGH therapy. Mean height SDS improved from -3.5 +/- 1.0 at initiation of therapy to -2.6 +/- 1.3 at 12 months. Mean serum creatinine and blood urea nitrogen levels remained stable during the study, while mean glomerular filtration rates decreased initially and then stabilized; however, 2 subjects had a significant deterioration of their renal function at 6 and 9 months of rhGH, requiring discontinuing treatment. Before rhGH treatment, total bone mineral content as well as bone mineral density in cortical and trabecular bone were significantly reduced in our patients when compared to healthy controls paired for chronological age and similar to those of a healthy control group paired for bone age and height. Both these parameters increased significantly during rhGH treatment so that at 12 months our patients had values similar to those seen in a healthy control population paired to our patients for chronological age. While trabecular bone mineral density did not change in a group of untreated uremic controls during 12 months of follow-up, the percent of bone mineral density change in trabecular bone in our uremic patients during 12 months of rhGH treatment was very significant (p < 0.001) and larger than that noted in a group of healthy controls paired for bone age and height during 12 months of follow-up. This study demonstrates how rhGH treatment in prepubertal uremic children increases their growth velocity and their bone mineral density significantly, with an improvement in height for age. Careful followup of the renal function of patients in needed as they improve their height and bone mineral status.

Blood Urea Nitrogen↗
PubMed1996

Type II cystic adenomatoid malformation: late diagnosis in a patient with a pulmonary mass.

We hereby report the case of a 22-year-old patient with a final diagnosis of type II cystic adenomatoid malformation, who was hospitalized due to repeated pulmonary infections. The radiographic study demonstrated a worrying image of a pulmonary mass. The different studies performed, did not put forward the diagnosis, so at last the patient was proposed a thoracotomy for diagnostic and therapeutic purposes.

Adult↗
PubMed1995

Phenotypic and phylogenetic characterization of some unknown coryneform bacteria isolated from bovine blood and milk: description of Sanguibacter gen.nov.

16S rRNA gene sequencing studies were performed on some Gram-positive coryneform bacteria of unknown taxonomic position isolated from blood and milk of healthy cows. Comparative sequence analysis demonstrated that the milk isolates corresponded to Oerskovia xanthineolytica whereas those from blood consisted of two distinct, albeit highly related species, within the family Cellulomonadaceae. Based on the phylogenetic and phenotypic distinctiveness of the blood isolates, it is proposed that they be classified in a new genus Sanguibacter.

Actinomycetales↗
PubMed1995

Simple and rapid detection of Mycobacterium tuberculosis complex organisms in bovine tissue samples by PCR.

Mycobacterium bovis is a slowly growing microorganism, and confirmation of the diagnosis by conventional culture is a lengthy process. A simple, rapid method for the extraction of DNA from bovine tissue samples was developed and used in a PCR designed for the diagnosis of tuberculosis. Tissues from 81 cattle from tuberculosis-infected herds (group 1) and 19 cattle from tuberculosis-free herds (group 2) were tested in this PCR, and the results were compared with those of conventional culture. The PCR assay detected 71.4% of the culture-positive animals from group 1. Tissue from all animals in group 2 were negative in the PCR assay and by culture. The described method could be used as a rapid screening technique which would be complementary to culture of tissue specimens for the routine diagnosis of bovine tuberculosis. The PCR technique is much faster than culture and reduces the time for diagnosis from several months to 2 days. It also provides for the detection of M. bovis when rapidly growing Mycobacterium spp. are present in the sample and may be able to detect the presence of M. bovis in samples even when organisms have become nonviable.

Animals↗
PubMed1995

Bioavailability comparison between albendazole and albendazole sulphoxide in rats and man.

Albendazole (ABZ) is a broad spectrum anthelmintic benzimidazole with very low bioavailability, and its activity is due to its main metabolite, Albendazole sulphoxide (ABZS). This work demonstrates the improvement of bioavailability when the ABZS is directly administered, compared with the ABZ administration, both orally given. This observation may be used as an interesting target in the design of new drugs with antihelmintic activity in systemic diseases, using ABZS as a parent drug.

Adult↗
PubMed1994

Actinic prurigo.

Explore the source record for details and available documents.

Humans↗
PubMed1993

Application of a diphasic dialysis technique to the extraction of aflatoxins in dairy products.

A new method is described for the extraction of aflatoxins from milk and milk products based on a diphasic dialysis technique, followed by detection and quantification of aflatoxins by TLC. Recovery was 65 to 99% for aflatoxins B1, G1, and M1, and the detection limit in milk and yogurt was .01 to .02 ppb for all aflatoxins studied. In cheese, the detection limit was .03 to .04 ppb for aflatoxins B1 and G1 and .1 ppb for aflatoxin M1. The main advantages of this technique are its simplicity; sensitivity; very economical use of reagents, thereby minimizing environmental pollution; efficiency, allowing the quick processing of a high number of samples; use by laboratories with little equipment; and a sensitivity comparable with that of much more sophisticated techniques.

Aflatoxin M1↗
PubMed1992

A microbiological, histopathological and immunohistological study of the intragastric inoculation of Listeria monocytogenes in mice.

The course of murine infection after intragastric inoculation of L. monocytogenes was investigated by immunocytochemical, histopathological and microbiological techniques. L. monocytogenes antigen was observed in epithelial cells of intestinal mucosa overlying Peyer's patches, but not in mucosa devoid of them. This suggests that penetration of L. monocytogenes into the host organism may take place through epithelium overlying Peyer's patches. The efficiency of bacterial penetration appeared to be low, as shown by the small amounts of L. monocytogenes antigen detected and the low counts of bacteria in organs. Gross or histopathological lesions in the intestinal tract were not observed. The presence of L. monocytogenes in spleen, liver and in maxillary and mesenteric lymph nodes, confirmed that the systemic course of infection by this route of inoculation is similar to that of the parenteral routes. The results emphasize the subclinical character of murine listeriosis by the oral route.

Administration, Oral↗
PubMed1992

A direct plating method for monitoring the contamination of Listeria monocytogenes in silage.

Twenty-two silage samples were analyzed for the presence of L. monocytogenes using five Listeria selective plating media, with and without previous selective enrichment step. L. monocytogenes was recovered from 3 samples by both procedures, but direct plating allowed the quantification of Listeria population. Two of these positive samples were implicated in outbreaks of listeriosis in sheep; the L. monocytogenes population in these samples was about 10(6) cells/g. The L. monocytogenes population in the other positive sample was 10(3) cells/g. Direct isolation of L. monocytogenes was only possible from LPM, PALCAM and LSAMm media. MOX and LSM media were not selective enough to allow direct Listeria isolation. In our hands, LSAMm was the most suitable plating medium for the direct isolation and specific quantification of L. monocytogenes from silage employing a red blood cells overlay technique.

Animals↗
PubMed1992

Role of potassium tellurite and brain heart infusion in expression of the hemolytic phenotype of Listeria spp. on agar plates.

The influence of potassium tellurite (PT) and brain heart infusion agar (Difco), two components of modified Listeria selective agar medium (LSAMm), on the hemolytic phenotype of Listeria spp. was studied. L. monocytogenes and L. ivanovii displayed bigger zones of hemolysis on brain heart intusion agar compared with on Columbia agar base. The addition of PT increased the sizes of zones of hemolysis displayed by L. monocytogenes. This effect seemed to be produced by the enhancement of the cytolytic effect of listeriolysin O. PT decreased the hemolysis produced by L. ivanovii, and this effect seemed to be due to an inhibition of the sphingomyelinase C produced by this species.

Culture Media↗
PubMed1992

Lymphatic drainage of Listeria monocytogenes and Indian ink inoculated in the peritoneal cavity of the mouse.

The lymphatic drainage of the peritoneal cavity has been investigated by intraperitoneal inoculation of an intracellular bacterium (Listeria monocytogenes) and an inert marker (Indian ink). The results reveal that both agents are transported, either after phagocytosis by intraperitoneal macrophages or in suspension in the lymph, towards the cranial sternal lymph nodes (Lymphonodi sternales craniales) of the ventral thoracic lymphocentrum (Lymphocentrum thoracicum ventrale) and to the lymph nodes of the mediastinal lymphocentrum (Lymphocentrum mediastinale), prior to systemic dissemination. This mechanism of peritoneal lymph drainage has relevance on experimental studies involving the inoculation of pathogens, and on the investigation of metastatic diffusion of neoplasms from the peritoneum.

Animals↗
PubMed1992

Epidemiologic investigation of a silage-associated epizootic of ovine listeric encephalitis, using a new Listeria-selective enumeration medium and phage typing.

The role of silage feeding in the origin of an epizootic of encephalitic listeriosis in a sheep flock was investigated by use of a new direct Listeria-selective isolation and enumeration medium, in combination with serotyping and phage typing. The silage contained high numbers (about 10(6) cells/g) of a L monocytogenes strain indistinguishable with respect to serovar and phagovar from that isolated from the brains of sick sheep. These results provided unambiguous bacteriologic evidence of the epidemiologic link between silage consumption and listeriosis in ruminants.

Animals↗
PubMed1991

Pathogenesis of lymphoid lesions in murine experimental listeriosis.

Adult female Swiss albino mice were infected intraperitoneally or subcutaneously with Listeria monocytogenes Serovar 4b or 1/2a and killed at intervals. Thymus, spleen, Peyer's patches and a variety of lymph nodes, including the jejunal (mesenteric), mediastinal, lumbar, mandibular and superficial inguinal, were examined by histopathology and by immunocytochemistry for detection of L. monocytogenes antigen. Similar results were obtained with both Serovars and by both routes of inoculation used. In the spleen, L. monocytogenes was detected, by immunoperoxidase staining, as soon as 4 h after inoculation, inside phagocytic cells located predominantly in the marginal zone of the white pulp. This was followed by inflammation, necrosis and depletion of lymphoid cells, which extended in extreme cases to the whole organ. Inflammatory lesions diminished progressively at 5 to 6 days after inoculation. In animals dying of the infection, a severe necrotizing splenitis was present. Depletion of lymphoid cells and inflammatory changes were widespread in the lymph nodes and to a lesser extent in the Peyer's patches. An extensive necrotizing lymphadenitis was the prominent lesion in severely affected nodes. Inflammatory lesions and detection of L. monocytogenes antigen started around the venules of high endothelium. A thymus depletion, not associated with the multiplication of bacteria in the organ, was also a constant feature of the infection. This study suggests that L. monocytogenes (1) is transported to the spleen and to the lymph nodes by phagocytes, entering the organs by the marginal sinus in the spleen and by the venules of high endothelium in the lymph nodes; (2) multiplies in these cells as well as in neutrophilic granulocytes (the latter rapidly migrate to the affected zones); and (3) induce a splenitis and lymphadenitis, involving predominantly T cell-dependent areas, with a necrotizing component in severe cases. From our observations it is concluded that infection of the lymphoid system is a major feature in the pathogenesis of murine listeriosis.

Animals↗
PubMed1990

Revision of the antigenic structure of genus Listeria.

O-antigenic structure of genus Listeria was studied, using antisera (obtained from rabbits) against different O-antigens of reference strains of each serovar. The titres of sera were determined by agglutination using antigens of the same reference strains as well. Some differences from the actual scheme were found: serum antifactor-IX gave a lower titre than expected against antigens 4ab and 6b, while the titre observed against antigen 4b was higher than the expected in this case. Serum antifactor-VIII presented a higher titre than could be expected against antigen 6b. The strains of serovars 4d and 4e used in this experience were impossible to distinguish, and could have been classified in the same serovar. We could not obtain serum antifactor-XI from serovar 6b after several trials. From these differences we propose some modifications of the current antigenic scheme of genus Listeria.

Antibodies, Bacterial↗