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Biomedical subjects

J Blanco

Publications and source records attributed to J Blanco.

At least 199 records · Page 11Linked to original sources
PubMed1996

Detection of enterohaemorrhagic Escherichia coli O157:H7 in minced beef using immunomagnetic separation.

Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 has been recently recognized as a human pathogen associated with haemorrhagic colitis and haemolytic uraemic syndrome. Most outbreaks of haemorrhagic colitis resulted from the consumption of undercooked minced beef or raw milk. Dairy cattle have been identified as a reservoir of EHEC O157: H7. In this study E. coli O157 specific antibody, coated on magnetic beads, was used to concentrate and release EHEC O157:H7 from meat samples. A survey of retail fresh minced beef and hamburger samples using this procedure revealed that 3 (5%) of 58 beef samples were positive for EHEC O157:H7. Two of the strains produced both VT1 and VT2 verotoxins, and one produced only VT2. Immunomagnetic separation is a sensitive and simple technique for the isolation of E. coli O157 from food, and could be useful for a further elucidation of the epidemiology of this organism. The relatively high prevalence of EHEC O157:H7 in beef samples may constitute a risk for public health. Thus, a suitable epidemiologic control and effective methods of prevention should be applied.

Animals↗
PubMed1996

[Colonic tuberculosis as a cause of rectal bleeding in 2 patients with HIV infection].

BACKGROUND: Extrapulmonary tuberculosis is a relatively frequent disease in patients with HIV infection. This may be observed coinciding with pulmonary involvement or without diagnostic data of the same. Within extrapulmonary involvement, gastrointestinal involvement is one of the least frequently observed and its diagnosis is very difficult due to the scarce clinical suspicion because of the unspecific symptomatology. METHODS: Segmentary colonic tuberculosis was diagnosed in two patients presenting rectal bleeding. The diagnosis was neither clinically nor endoscopically suspected and only histologic and microbiologic study of the biopsies led to establishment of the diagnosis. Pulmonary involvement was also seen in one of the 2 patients. RESULTS: Medical treatment was initiated following the diagnosis. The evolution was good in one patient, while the other developed a picture of massive rectal bleeding requiring surgical resection following which the patient died due to complications. CONCLUSIONS: Colonic tuberculosis is an infrequent disease in patients with HIV infection. Only a high index of clinical suspicion along with adequate histopathologic and microbiologic study of all the colonic lesion biopsies can establish the real frequency of this disease in this group of patients.

Adult↗
PubMed1995

[Possible relationship between overweightness and prevalence of hyperlipemia in the children of patients with heterozygote familial hypercholesterolemia and combined familial hyperlipemia].

BACKGROUND: Heterozygote familial hypercholesterolemia and combined familial hyperlipemia are associated to a greater risk of coronary disease. Combined familial hyperlipemia has classically been indicated to manifest after the second decade in life. The aim of this study was to establish whether a systematic search would demonstrate the existence of combined familial hyperlipemia earlier and analyze whether the antropometric parameters related with the overweightedness accompany the appearance of the lipid disorders of this disease found at an early age. PATIENTS AND METHODS: Different lipid parameters were studied in 89 subjects under the age of 18 who were children of patients with heterozygote familial hypercholesterolemia and combined familial hyperlipemia. Likewise the weight, height and waist/hip quotient were evaluated. Hyperlipemia was considered as the presence of cholesterol/LDL and/or triglicerides greater than the 95 percentile for age and sex. RESULTS: Hyperlipemia was observed in 51% and 40% of the children of patients with heterozygote familial hypercholesterolemia and combined familial hyperlipemia, respectively. The body mass index and the waist/hip quotient of the latter children significantly correlated with the cholesterol-HDL values and the LDL/HDL quotient. CONCLUSIONS: The patients with known combined familial hyperlipemia have a high percentage of children with hyperlipemia during infancy. These data suggest a possible association between obesity in the appearance of hyperlipemia in the children of patients with combined familial hyperlipemia at this age.

Adolescent↗
PubMed1995

Toxigenic Escherichia coli in Spanish piggeries from 1986 to 1991.

Four-hundred and fourteen faecal samples from pigs with diarrhoea, oedema disease or healthy pigs, were collected from 65 piggeries located in different areas of Spain from 1986 to 1991. A total of 1334 Escherichia coli cultures were isolated from the pigs and studied for production of heat-labile (LT) and heat-stable (STa) enterotoxins, verotoxin (VT) and for type 1 (CNF1) and type 2 (CNF2) cytotoxic necrotizing factors. Strains producing enterotoxins (P < 0.001) or verotoxin (P < 0.05) were associated with enteric diseases of pigs. In the majority (82.3%) of piglets with strains, producing verotoxin the strains were also positive for production of STa enterotoxin. The most frequent toxin detected was STa. Although we isolated strains producing CNF1 from 1.5% of sick pigs, they were not statistically associated (P < 0.7) with enteric disease. Pigs may constitute a natural reservoir of CNF1 producing E. coli strains in Spain; their presence in the porcine intestine may be of significance in public health because such strains have been associated with human extraintestinal infections.

Animals↗
PubMed1995

Lipoprotein concentrations in normolipidemic males consuming oleic acid-rich diets from two different sources: olive oil and oleic acid-rich sunflower oil.

The effects on plasma lipid concentrations of two oleic acid-rich diets, prepared with two different plant oils--olive oil and sunflower oil high in monounsaturated fatty acids (MUFAs)-- were compared with a National Cholesterol Education Program (NCEP) I diet. Twenty-one healthy, normolipidemic, young males consumed an NCEP-I diet (30% of energy as fat) during a 25-d period. Subjects were then assigned to two 4-wk study periods, according to a randomized, crossover design. Group one was placed on an olive oil-enriched diet (40% fat, 22% MUFAs), followed by a 4-wk period of a sunflower oil-enriched diet (40% fat, 22% MUFAs). In group two, the order of the diets was reversed. Both MUFA dietary periods resulted in an increase in high-density-lipoprotein (HDL) cholesterol (7% for the olive oil diet and 4% for the sunflower oil diet) and in apolipoprotein (apo) A-I (9% for both) compared with the NCEP-I diet. Low-density-lipoprotein (LDL) cholesterol and apo B concentrations (x +/- SEM) were lower (P < 0.05) during the sunflower oil diet (2.40 +/- 0.11 mmol/L, 0.85 +/- 0.04 mg/L) than during the olive oil diet (2.64 +/- 0.15 mmol/L, 0.93 +/- 0.05 mg/L). No significant differences were observed in these variables between the sunflower oil and NCEP-I (2.48 +/- 0.13 mmol/L, 0.89 +/- 0.04 mg/L) diets.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Isolation of K88 antigen variants (ab, ac, ad) from porcine enterotoxigenic Escherichia coli belonging to different serotypes.

Fimbriae isolation by means of thermal shock was applied to fifteen K88-positive (three K88ab, nine K88ac and three K88ad) Escherichia coli reference strains belonging to serotypes O8:K87, O32, O45, O138:K81, O141:K85, O147:K89, O149:K91, and O157, as well as to ten K88-positive enterotoxigenic strains isolated from porcine diarrhea in Spain, all of them belonging to the O149 serogroup. Fimbriae were removed from the bacterial cells by thermal shock at 60 C and then precipitated using ammonium sulfate. The final amount of K88 antigen and the purification degree were not related to the serogroup of the bacteria or to the antigen variant but were related to the buffer used for isolation. Phosphate buffer containing urea was shown to be more effective than Tris-HCl for isolation of K88 antigen. The molecular weights by SDS-PAGE for K88ab, K88ac, and K88ad were 28.5, 29.2, and 31.0 kDa, respectively. All enterotoxigenic E. coli strains isolated in Spain showed the K88ac variant.

Animals↗
PubMed1995

Mouse retinoid X receptor contains a separable ligand-binding and transactivation domain in its E region.

Steroid, thyroid, and retinoid hormones exert their biological functions by interacting with their cognate nuclear receptors. Upon binding receptors, hormones induce a protease-resistant structural change in the receptor ligand-binding domain and subsequently activate the receptors. Utilizing partial proteolysis, we have been able to delineate a region in the mouse retinoid X receptor beta (mRXR beta) required for ligand binding. A separable activation domain within the mRXR beta E region has been identified. The activation domain, which is 21 amino acids in length, is located at the extreme C terminus of mRXR beta. This domain is not required for ligand binding since removal of this sequence neither eliminates the ligand-induced, protease-resistant conformational change nor alters the ligand-enhanced DNA binding. Furthermore, deletion of this activation domain converts the receptor into a transcriptional silencer. Finally, a further truncation of 9 amino acids (for a total of 30 amino acids) from the C terminus results in a mutant which does not undergo the protease-resistant conformational change and cannot bind DNA as a homodimer. Nevertheless, this mutant is still able to form a heterodimer with the thyroid hormone receptor. Therefore, homodimerization and heterodimerization can be distinguished by this nine-amino-acid sequence.

Amino Acid Sequence↗
PubMed1995

In vitro morphometric and proliferative variations in VIP-immunoreactive pituitary cells induced by estradiol.

Using double labelling for proliferating cell nuclear antigen (PCNA) and vasoactive intestinal peptide (VIP), a study was conducted to elucidate the repercussions of the addition of estradiol to monolayer pituitary cultures on the morphology, size, number, mitotic index and PCNA labelling index of VIP-immunoreactive cells, comparing the results with those obtained in control cultures. The addition of estradiol (100 nM) over 3 h of incubation led to a significant increase (p < 0.01) in the cellular, cytoplasmic and nuclear areas of VIP-immunoreactive cells and in the number of these cells. The same treatment elicited an even greater increase in the mitotic index (p < 0.01) and PCNA labelling index (p < 0.01) of VIP-immunoreactive cells. The results obtained suggest that estrogens induce proliferation and hyperplasia of in vitro VIP-immunoreactive pituitary cells.

Animals↗
PubMed1995

[Enterotoxigenic, verotoxigenic, and necrotoxigenic Escherichia coli in food and clinical samples. Role of animals as reservoirs of strains pathogenic for humans].

Toxigenic Escherichia coli of human and animal origin have been classified into three categories: enterotoxigenic E. coli (ETEC), verotoxigenic E. coli (VTEC), and necrotoxigenic E. coli (NTEC), ETEC are a major cause of infant diarrhoea in less-developed countries and frequently cause colibacillosis in domestic animals. Human ETEC strains may synthesize LT-I and/or STa enterotoxins and they may possess the colonization factors CFA/I to CFA/IV; porcine strains synthesize LT-I, STa and/or STb, and possess the colonization antigens K88, P987, K99 or F41; and bovine strains are usually STa producers harbouring on the bacterial surface K99 or F41 colonization factors. There is a high host-specificity, because of that ETEC from animals are not pathogen for humans. VTEC strains may produce three mainly types of verotoxins (VT1, VT2, VT2vp1) that are functionally and structurally related to the shiga toxin. The VTEC of human and bovine origins produce VT1, VT2 or both, whereas VT2vp1 is elaborated by E. coli that cause edema disease in swine. The VTEC strains belonging mainly to serotypes O157:H7 or H-, O26:H11 and O111:H-, are now considered to be the major cause of two human syndromes of hitherto unknown cause: hemorrhagic colitis and hemolytic uremic syndrome. Most outbreaks of VTEC infection occurred in USA, Canada and United Kingdom during the last ten years and have been linked to consumption of undercooked ground beef, and, to a lesser extent, to the drinking of unpasteurized milk. Thus, the principal reservoir of VTEC is the intestinal tract of cattle. By contrast, it is presumed that human beings are the major reservoir of ETEC, and that contaminated water is a principal vehicle for transmission of ETEC infections. NTEC strains are able to elaborate two types of cytotoxic necrotizing factors (CNF1 and CNF2). Strains of human origin usually produce CNF1, whereas bovine NTEC generally synthesize CNF2. NTEC strains are not responsible for food-associated outbreaks of gastroenteritis, but CNF1 and CNF2 are very good markers of the source of food contamination.

Animals↗
PubMed1995

[Virulence factors and 0 serogroups of Escherichia coli as a cause of community-acquired urinary infections].

BACKGROUND: The aim of this study was to determine the virulence factors and 0 serogroups of E. coli strains that cause community acquired urinary tract infections (UTI). METHODS: We examined 103 E. coli strains isolated from the urine of patients with UTI. The following virulence factors were investigated using phenotypic techniques: the alpha-haemolysin (Hly), the cytotoxic necrotizing factor type 1 (CNF-1) and the mannose-resistant haemagglutination (MRHA) types III, IVa and IVb expressed by P fimbriated E. coli. Serotyping of 0 antigen was carried out by means of a microtechnique using 163 antisera. RESULTS: Fifty-five (53%) of the 103 E. coli strains examined showed some of the virulence factors investigated in this study; 41% of the strains were Hly+, 28% were CNF-1+ and 48% expressed MRHA types III, IVa or IVb. The uropathogenic strains characterized belonged to 27 different 0 serogroups. However, 68% were from one of 10 serogroups (01, 02, 04, 06, 09, 018, 027, 073, 075 and 077) and 36% were from one of only 3 serogroups (02, 04 and 06). Furthermore, the virulence factors were concentrated in strains belonging to the 3 serogroups most frequently detected. Thus, 36 (97%) of the 37 strains of these 3 serogroups showed virulence factors, versus only 19 (29%) of 66 belonging to other serogroups (p < 0.001). CONCLUSIONS: Our results support the special pathogenicity theory and suggest that many cases of community acquired UTI may be caused by a limited number of uropathogenic E. coli strains that produce toxins (Hly+ and/or CNF-1+) and possess P fimbriae or P-related adhesins (with MRHA types III, IVa or IVb), and that usually belong to 02, 04 and 06 serogroups.

Community-Acquired Infections↗