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Biomedical subjects

J L Muñoz

Publications and source records attributed to J L Muñoz.

At least 19 recordsLinked to original sources
PubMed1999

In vitro evaluation of the amebicidal activity of Buddleia cordata (Loganiaceae, H.B.K.) on several strains of Acanthamoeba.

Infectious diseases produced by free-living amoebae from the genus Acanthamoeba have been recently recognized. The need for antiamebic compounds is urgent as the occurrence of these diseases is being registered more frequently since the late sixties. We screened the aqueous and methanolic extract of a plant used by folk medicine (Buddleia cordata) against eye and skin inflammation for antiamebic activity. We tested the extracts on 29 strains of free-living amoebae, with the result that they were amebostatic for 14 and 15 strains, respectively. We obtained linarin and vanillic acid from the extracts, but only linarin was amebostatic to all the strains and vanillic acid had no activity. However, acetyl vanillic acid had similar effects on amoebae to linarin. Threshold values of these two active compounds ranged from 31.25 microg/ml to 4 mg/ml and from 31.25 microg/ml to 8 mg/ml for linarin and acetyl vanillic acid, respectively. These differences in threshold values were observed even on several strains belonging to the same species (as in the case of A. castellanii and A. polyphaga) indicating the need of susceptibility testing for each clinical isolate of free-living amoebae.

Acanthamoeba↗
PubMed1999

The stress response of the gilthead sea bream (Sparus aurata L.) to air exposure and confinement.

We investigated short-term effects (up to 24 h) of air exposure and confinement, and long-term effects (up to 11 days) of confinement, to elucidate signalling pathways in the stress response of gilthead sea bream Sparus aurata L. Plasma glucose and lactate were taken as indicators of sympathetic activation, and alpha-melanocyte stimulating hormone (alpha-MSH), adrenocorticotrophic hormone (ACTH) and cortisol as indicators of activation of the brain-pituitary-interrenal (BPI) axis. Air exposure for 3 min resulted, within 30 min, in an increase in plasma concentrations of cortisol, alpha-MSH, glucose, lactate, osmolality and plasma Na, Cl and Mg. Plasma ACTH and beta-endorphin and plasma K, Ca and P did not change. We conclude that air exposure mainly activates the brain-sympathetic-chromaffin cell (BSC) axis. In fish confined at a density of 70 kg/m(3) (compared with 4 kg/m(3) in controls), cortisol, ACTH and alpha-MSH increased within 1 h, indicating activation of the BPI axis. Plasma glucose, Na, Cl and Mg increased with an 8 h delay compared with the response to air exposure. No changes in plasma lactate, osmolality, K, Ca and P were observed. Long-term confinement induced a biphasic cortisol response with peaks at 1 h and at 2 and 3 days. A gradual increase in plasma beta-endorphin concentrations peaked at 7 days; the concentration of alpha-MSH increased rapidly within 1 h and then declined to control values 4 days after the onset of confinement. No changes in ACTH were detected. Our data provide evidence that a stressor-specific activation of the BSC and BPI axes may occur in Sparus aurata.

Adrenocorticotropic Hormone↗
PubMed1998

Human T-lymphocyte transformation with human T-cell lymphotropic virus type 2.

Human T-cell lymphotrophic virus type 2 (HTLV-2), a common infection of intravenous drug users and subpopulations of Native Americans, is uncommon in the general population. In contrast with the closely related HTLV-1, which is associated with both leukemia and neurologic disorders, HTLV-2 lacks a strong etiologic association with disease. HTLV-2 does shares many properties with HTLV-1, including in vitro lymphocyte transformation capability. To better assess the ability of HTLV-2 to transform lymphocytes, a limiting dilution assay was used to generate clonal, transformed lymphocyte lines. As with HTLV-1, the transformation efficiency of HTLV-2 producer cells was proportionately related to the number of lethally irradiated input cells and was comparable to HTLV-1-mediated transformation efficiency. HTLV-2-infected cells were reproducibly isolated and had markedly increased growth potential compared to uninfected cells; HTLV-2 transformants required the continued presence of exogenous interleukin 2 for growth for several months and were maintained for over 2 years in culture. All HTLV-2-transformed populations were CD2 and/or CD3 positive and B1 negative and were either CD4+ or CD8+ populations or a mixture of CD4+ and CD8+ lymphocytes. Clonality of the HTLV-2 transformants was confirmed by Southern blot analysis of T-cell receptor beta chain rearrangement. Southern blot analysis revealed a range of integrated full-length genomes from one to multiple. In situ hybridization analysis of HTLV-2 integration revealed no obvious chromosomal integration pattern.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1998

[Seroprevalence versus Parvovirus B19 in blood donors].

BACKGROUND: The aim of the study was to describe the seroprevalence against Parvovirus B19 in a random sample of blood donors in the Hospital Universitario de Salamanca. METHODS: We studied the presence of IgG and IgM antibodies against Parvovirus B19 in 136 sera from asymptomatic blood donors by enzyme immunoassay methods. RESULTS: From 136 samples tested, 88 (64.7%) had positive absorbance values for IgG. Forty eight samples (35.5%) were negative. IgM was negative in all cases. We did not find indeterminate results. DISCUSSION: Parvovirus primoinfection usually happens in the childhood. Thus, we can expect a high percentage of general population to have antibodies against Parvovirus B19. Anti-Parvovirus B19 antibodies prevalence in blood donors was 64.7%. This failure is similar to data reported before (65%). Clinical importance of these viruses in currently related with hemathopoyesis diseases and with the possible role in theratogenesis. The presence of IgG seems to give protection except in some chronic infections recently described.

Antibodies, Viral↗
PubMed1996

Activity of trimethoprim/sulfamethoxazole plus polymyxin B against multiresistant Stenotrophomonas maltophilia.

The inhibitory activity of eight antibiotics and the inhibitory and bactericidal activities of combinations of trimethoprim/sulfamethoxazole (TMP/SMX) plus three fixed concentrations of polymyxin B (0.01 microgram/ml, 0.1 microgram/ml and 0.5 microgram/ml) against 30 multi-resistant strains of Stenotrophomonas maltophilia were tested. Polymyxin B at 0.01 microgram/ml modified the inhibitory activity of TMP/SMX against only 40% of strains. At 0.1 microgram/ml and 0.5 microgram/ml, polymyxin B enhanced the inhibitory activity of TMP/SMX activity against all strains. Polymyxin B enhanced the bactericidal activity of TMP/SMX only at concentrations near the minimum inhibitory concentration of polymyxin B alone.

Anti-Bacterial Agents↗
PubMed1995

Time course and cytokine dependence of human T-cell lymphotropic virus type 1 T-lymphocyte transformation as revealed by a microtiter infectivity assay.

Human T-cell lymphotropic virus type 1 (HTLV-1) enhances the growth of T lymphocytes, allowing the generation of T-lymphocyte cell lines. This report describes a limiting-dilution assay system which uses low input numbers of HTLV-1-producing cells for generation of T-lymphocyte cultures. The HTLV-1 transformants generated with this assay system produced high levels of HTLV-1 p24 antigen and required exogenous cytokines for maintenance. Clonal populations of CD4- or CD8-positive HTLV-1 transformants were generated with transformation efficiency rates as high as 78%. An exogenous cytokine is necessary for HTLV-1 T-lymphocyte transformation, and cytokine dependence is the most likely outcome of infection and transformation. HTLV-1 T-lymphocyte transformation can occur in the presence of cytokines other than interleukin-2 (IL-2), such as IL-4 or IL-7. IL-4- or IL-7-dependent HTLV-1 transformants underwent T-lymphocyte mitogenesis in response to their homologous cytokines but proliferated best in the presence of IL-2. Since the receptors for IL-2, IL-4, and IL-7 share the IL-2 gamma chain, this component may be the common element in the signaling pathway for HTLV-1-associated transformation.

CD4-Positive T-Lymphocytes↗
PubMed1995

[Importance of anaerobic bacteria in recurrent childhood non-streptococcal tonsillitis].

BACKGROUND: The presence of anaerobes in the oropharyngeal flora was already known, but they were infrequently involved in infections, except for specific diseases (abscesses, Vincent's angina). The involvement of anaerobes in more frequent by observed oropharyngeal diseases has been recently proposed. METHODS: We analyzed the tonsillar flora of 22 healthy children (control group) and 54 children diagnosed of recurrent tonsillitis. We compare the clinical response of children with recurrent tonsillitis to two treatments: penicillin, and penicillin plus metronidazole. RESULTS: We isolated Streptococcus pyogenes from 22.2% of children with tonsillitis, and did not isolate it from any healthy children. The rest of tonsillar flora was qualitatively similar in both groups. Both populations showed a high proportion of beta-lactamase-producer bacteria. In children from whom S. pyogenes was isolated, the response to the treatment was similar for both treatments. In those cases where S. pyogenes was not isolated, penicillin + metronidazole cured the 77.2% of children treated, but penicillin cured only 30% of cases. CONCLUSIONS: These results suggest that anaerobes might be involved, at least, in recurrent tonsillitis when S. pyogenes is not found, and justify further studies about the etiology and treatment of this disease.

Bacteria, Anaerobic↗
PubMed1994

[Development of a selective differential medium for the isolation of Corynebacterium urealyticum (group D-2)].

BACKGROUND: We have developed a new selective culture medium for the isolation of C. urealyticum, with the aim of improving and making easier the isolation and identification of this microorganism. MATERIAL AND METHODS: The medium is based on components similar to other media, usually used for diagnosis of urinary tract infections, also containing glucose, urea, phenol red, polysorbate 80 (Tween 80), polymixin B, amphotericin B, nalidixic acid and lyncomycin. The medium was tested in 65 clinical isolates and three type strains, and in 533 clinical samples of urine. RESULTS: All 65 clinical strains and 3 reference strains of C. urealyticum tested grew faster on this medium than on blood agar. E. coli, Klebsiella spp., Enterobacter spp., Citrobacter spp., M. morganii, Proteus spp., S. aureus, Enterococcus spp. and Corynebacterium spp. did not grow in the selective agar. S. epidermidis and Streptococcus spp. grew in less than 10% of cases, P. aeruginosa in 29.2% and Serratia spp. in 41.7%. The colonies were always easily differentiated from C. urealyticum. In the studies performed on 553 clinical samples from patients with urinary tract infections, six infections by C. urealyticum were detected. The growth of all strains being faster on this medium than on blood-agar. CONCLUSIONS: This new selective medium may be a valuable tool for diagnosis of UTIs caused by C. urealyticum in patients with retard risk factors.

Bacteria↗
PubMed1992

Neurocysticercosis in an Orthodox Jewish community in New York City.

BACKGROUND AND METHODS: From June 1990 through July 1991, intracerebral infection with the larval stage of the pork tapeworm Taenia solium was diagnosed in four unrelated persons in an Orthodox Jewish community in New York City. None of the patients had eaten pork, and only one had traveled to a country in which T. solium infection was endemic. We investigated this outbreak, screened serum samples from family members and household contacts for antibodies to cysticercosis, and examined stool specimens from household employees for eggs of taenia species. RESULTS: The four patients had recurrent seizures and brain lesions that were radiologically consistent with the presence of cysticerci. The diagnosis was confirmed in two patients by a brain biopsy, and in two by immunoblot assays for cysticercus antibodies. Of 17 immediate family members screened serologically, 7 from two families had cysticercus antibodies. Magnetic resonance imaging of the brain showed cystic lesions in two of the seropositive family members, one of whom had had a seizure. Examinations of six domestic employees from all four households revealed an active infection with taenia species in one and a positive serologic test in another. Since these women had recently emigrated from Latin American countries where T. solium infection is endemic, they were the most likely sources of infection in the members of these households. CONCLUSIONS: A diagnosis of neurocysticercosis should be considered in patients with seizures and radiologic evidence of cystic brain lesions, even in those who do not eat pork and who have not traveled to a country in which T. solium infection is endemic. Recent emigrants from countries in which T. solium infection is endemic should be screened for tapeworm infection in their stools before they are employed as housekeepers or food handlers.

Adolescent↗
PubMed1992

Selective transmission of human immunodeficiency virus type-1 variants from mothers to infants.

Multiple human immunodeficiency virus type-1 sequences from the V3 and V4-V5 regions of the envelope gene were analyzed from three mother-infant pairs. The infants' viral sequences were less diverse than those of their mothers. In two pairs, a proviral form infrequently found in the mother predominated in her infant. A conserved N-linked glycosylation site within the V3 region, present in each mother's sequence set, was absent in all of the infants' sequence sets. These findings demonstrate that a minor subset of maternal virus is transmitted to the infant.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Respiratory syncytial virus infection in C57BL/6 mice: clearance of virus from the lungs with virus-specific cytotoxic T cells.

We describe respiratory syncytial virus (RSV)-specific cytotoxic T-cell (CTL) lines and clones developed from the spleens of C57BL/6 and BALB/c mice. Line 7 and clones derived from it were H-2Kb restricted, whereas line 12 had both Kb and Db components. Both lines, and all the clones except one, could lyse targets infected with either strain A or strain B RSV. Line 7 or 7-11E1 cells (8 x 10(6) to 10 x 10(6) given intravenously cleared RSV from the lungs of infected mice. There was no morbidity or mortality in any of the infected mice whether or not they received T cells. The C57BL/6 mouse is a useful model system in which to study the role of the CTL response in protective immunity to RSV. CTL lines and clones can mediate clearance of RSV from the lungs of normal mice without producing any associated morbidity.

Animals↗