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Biomedical subjects

S Rojo

Publications and source records attributed to S Rojo.

At least 19 recordsLinked to original sources
PubMed2000

Annual and spatial activity of dung flies and carrion in a Mediterranean holm-oak pasture ecosystem.

The annual activity and spatial distribution of Muscidae and Calliphoridae were investigated in a holm-oak ('dehesa') ecosystem in western Spain over two years in pasture and woodland habitats, using wind-orientated traps baited with a mixture of fresh cattle faeces, liver and sodium sulphide solution. Lucilia sericata (Meigen) was always the dominant species and, with Chrysomya albiceps (Weidemann), Hydrotaea ignava (Harris), Muscina levida (Harris) and Muscina prolapsa (Harris), was more abundant during the second than the first year. By contrast, Calliphora vicina Robineau-Desvoidy, Calliphora vomitoria (L.), Hydrotaea armipes (Fallén), Hydrotaea penicillata (Rondani) and Hydrotaea dentipes (Fabricius) were more numerous during the first than the second year of the study. In summer, the Diptera sampled were significantly more abundant in a wooded than a pasture area. However, in autumn, while H. penicillata remained significantly more abundant in woodland, L. sericata became more abundant in the pasture, whereas C. vicina was captured in open and wooded areas in similar proportions. During winter and spring the populations sampled were relatively small. The changing patterns of abundance are discussed in relation to differences in climate within and between years.

Animals↗
PubMed1999

Flow cytometric detection of HLA antibodies using a spectrum of microbeads.

We describe here the use of HLA antigen coated beads for specificity and class determination of HLA antibodies by flow cytometry. The HLA specificity of antibodies was determined by use of beads containing eight levels of fluorescence. HLA antigens isolated from eight cultured cells were coated onto these beads so that each bead was the equivalent of one cell. By using four sets of eight beads, an equivalent of 32 cells could be examined in four test tubes. A total of 76 class I and 25 class II specificities could be determined by the 32 class I bead-panel and 32 class II bead-panel used, respectively. We noted no cross-reactivity of reactions between class I and II. The sensitivity of the test was shown to be higher than that of the standard cytotoxicity by dilution experiments and detection of additional cross-reacting antigens. By use of these coated beads, we achieved improved standardized detection of HLA antibodies. Antigen-coated beads have several advantages over the use of spleens or lymphocytes. (a) A highly selected panel of antigens can be routinely used. (b) Class I and class II antibodies can be readily distinguished from each other, even when they are present as mixtures in one serum. (c) Non-HLA antibodies are not detected because the beads do not have any other antigens than HLA on them. (d) The quantity of antigens coated on beads is more uniform than that found in cells from different individuals. (e) Beads are more convenient for storage and daily use.

Antibodies, Monoclonal↗
PubMed1998

Simultaneous HLA Class I and Class II antibodies screening with flow cytometry.

A flow cytometric method of simultaneously screening both HLA Class I and Class II panel reactive antibodies (PRA) was developed using a pool of 30 different Class I and 30 different Class II microbeads coated with purified HLA antigens. The antibodies in the serum that react specifically to the coated HLA antigens are detected by using a FITC-conjugated antibody against human IgG. Percent PRA can be determined by the percentage of microbeads that react positively to the serum. There is no cross-reactivity between the Class I and Class II microbeads. A mixture of Class I and Class II microbeads can be distinguished by their different fluorescent properties on the flow cytometry analysis. Thus, both Class I and Class II PRA can be detected from a single tube reaction.

Antibodies↗
PubMed1998

Occupational allergic contact dermatitis from cyanoacrylate.

Cyanoacrylates are widely used in adhesive techniques. Cyanoacrylate adhesives differ physically for the different needs of application, and chemically in function of the size of ester molecules. A 40-year-old man employed at the National Mint and Stamp factory presented with hyperkeratotic lesions on the fingers of the right hand. His job consisted of fixing microchips to plastic phone cards with Loctite Series 414. Patch testing confirmed sensitivity to cyanoacrylates. After the diagnosis of allergic contact dermatitis was established, the patient, to be cured of the dermatitis, changed his workplace 2 months later.

Adhesives↗
PubMed1997

Type I transmembrane receptor with inhibitory function in mouse mast cells and NK cells.

The MHC class I-specific inhibitory receptors on human and mouse NK cells have surprisingly different structures. The mouse receptors (Ly-49) are type II transmembrane glycoproteins of the C-type lectin family, whereas the human receptors (killer cell inhibitory receptors (KIR)) belong to the Ig superfamily. This difference prompted a search for Ig-like inhibitory receptors in mice. Here we show that gp49, a mouse mast cell protein of unknown function but with sequence similarity to KIR, is expressed in NK cells. The gp49 cytoplasmic tail, containing a sequence related to an inhibitory motif shared by KIR and Ly-49, delivered a strong inhibitory signal in both human and mouse NK cells when substituted for a KIR cytoplasmic tail. These data show that Ig-like receptors with inhibitory properties exist in both species and that mouse mast and NK cells may recognize common inhibitory ligands.

Animals↗
PubMed1997

Binding of a soluble p70 killer cell inhibitory receptor to HLA-B*5101: requirement for all three p70 immunoglobulin domains.

Lysis of target cells by natural killer (NK) cells can be prevented by killer cell inhibitory receptors (KIR) specific for major histocompatibility complex class I molecules. Functional studies have identified two distinct p58 KIR, each reactive with a different group of HLA-C allotypes, and distinct p70 KIR specific for some HLA-B or HLA-A allotypes. The NK specificities for each group of HLA-C allotypes have been reproduced by direct binding of recombinant soluble p58 molecules. Here, we show that a soluble p70 KIR binds to HLA-B*5101, but not to HLA-A or HLA-C molecules. Truncated soluble forms of the HLA-B*5101-specific p70 KIR, including one with two immunoglobulin (Ig) domains reactive with a monoclonal antibody that blocks p70 KIR function, did not bind to HLA-B*5101, indicating that all three Ig domains are required for binding.

HLA-B Antigens↗
PubMed1997

Killer cell inhibitory receptors: diversity, specificity, and function.

NK cells selectively kill target cells that fail to express self-MHC class I molecules. This selective killing results from a balance between inhibitory NK receptors specific for MHC class I molecules and activating receptors that are still largely unknown. Isolation of molecular clones for the human killer cell inhibitory receptors (KIR) revealed that KIR consist of a family of molecules with Ig ectodomains and cytoplasmic tails of varying length. Soluble complexes of KIR and HLA-C molecules established that KIR recognizes and binds to its ligand as an autonomous receptor. A functional expression system in human NK clones demonstrated that a single KIR can provide both recognition of MHC class I and delivery of a dominant negative signal to the NK cell. Functional evidence has been obtained for a role of the tyrosine phosphatase SHP-1 in KIR-mediated inhibition. The presence of a conserved motif used to recruit and activate SHP-1 in the cytoplasmic tail of KIR and of the mouse Ly-49 inhibitory receptor (otherwise structurally unrelated to KIR) represents an interesting case of evolutionary convergence. Furthermore, the motif led to the identification of other receptors with inhibitory potential, including a type I Ig-like receptor shared by mouse mast cells and NK cells.

Amino Acid Sequence↗
PubMed1997

[Treatment with tuberculostatic drugs: compliance at a general hospital].

The purpose of this study was to assess the compliance with tuberculostatic drugs treatment in a public hospital from Córdoba City and to establish the causes of noncompliance. All the patients to which treatment with tuberculostatic drugs was indicated from January 1991 up to December 1994 were included. 45 patients were included: 18 females (40%) and 29 males. Sixteen (35.6%) did not complete the time of treatment indicated. Nine (56.3%) abandoned the treatment 2 months after having initiated it. In the group that did not complete the treatment there was a higher percentage of female patients (62.5%) than in the group that did complete it (27.6%), p = 0.02. There were not statistically significant differences in age, percentages of pulmonar and extrapulmonar tuberculosis and months of treatment indicated between both groups. Thirty-six percent of the patients who abandoned the treatment referred having interrupted it due to their own negligency, knowing the risk of such behavior; 36% suffered side effects and did not come back to hospital; 21% referred having consulted another physician who indicated to interrupt the treatment without performing other tests; and 7% misunderstood the indications. It is concluded that in a general hospital from Córdoba City, the percentage of patients who abandoned tuberculostatic treatment is high. In most cases the cause was related to failures in the conduct of patients, physicians or both.

Antitubercular Agents↗
PubMed1997

[Single dose of fleroxacin for the treatment of adult acute diarrhea].

The purpose of this work was to evaluate the efficacy and safety of a single dose of 400 mg of fleroxacin for the empiric antibiotic treatment of acute diarrhea in adult patients. A prospective, double-blind, placebo-controlled, randomized trial was designed. All the adult patients who consulted in our hospital for acute diarrhea from December 1994 to April 1995 were included. 72 patients were randomized to receive a single dose of fleroxacin 400 mg and 73 were placebo. Thirty-eight patients in each group were evaluable for efficacy. Between both groups there were not statistically significant differences in age, sex, number of loose stools per day at inclusion, days since the onset of symptoms up to inclusion, other symptoms than diarrhea at inclusion, percentages of bacterial pathogens and parasites isolated and symptomatic treatment indicated. At the third day since inclusion, clinical cure occurred in 72.2% of the patients receiving fleroxacin, compared with 36.4% of those receiving placebo; p = 0.002. The mean +/- SD time to cure was 2.2 +/- 1.2 days in the fleroxacin group and 3.2 +/- 2.0 days in the placebo group; p = 0.01. Twenty-eight and 16.7% of patients reported adverse effects in the fleroxacin and placebo groups respectively; p = 0.3. It is concluded that a single dose of fleroxacin 400 mg is an effective and safe alternative for the empiric antibiotic treatment of acute diarrhea in adults.

Acute Disease↗
PubMed1997

[A case report of reversible biliary pseudolithiasis caused by ceftriaxone in childhood: does the problem deserve greater attention?].

The authors report the case of a nine-year-old girl admitted to hospital with signs of meningeal irritation during the course of hyperpyretic phlogosis of the upper airways who presented, after 6 days' treatment with CFTX, at a dose of 50 mg/kg/day (1.5 g/day), therefore at the maximum recommended dose for the antibiotic in question, symptomatic cholecystic "pseudolithiasis" which resolved two weeks after the suspension of the drug. This case appears to concord with recent reports of "pseudolithiasis" in childhood that appeared with doses not regarded as being at risk, and it draws attention to the etiopathogenetic importance of other factors, including familial recurrence. The authors recommend a reasonable use of CFTX and the need to be "vigilant" both in relation to the onset and evolution of the clinical condition described above.

Ceftriaxone↗
PubMed1996

Infundibulocystic basaloid neoplasm.

Infundibulocystic basal cell carcinoma was described in 1987 as a new type of basal cell carcinoma with follicular differentiation. A great controversy followed this description, mainly about the malignant or benign character of this neoplasm and the distinction from other tumors with follicular differentiation. We present two new cases of this neoplasm: the first one had the typical features of this entity, except for the absence of stroma; the second one showed in the deep portion basaloid nodules similar to those of a nodular basal cell carcinoma. We review the criteria adduced to establish the malignant character of this neoplasm and conclude that both the nosology and biological behavior of this neoplasm with follicular differentiation remain to be determined.

Aged↗
PubMed1996

Multiple hidrocystomas.

Apocrine hidrocystoma is a cyst from the secretory portion of the apocrine sweat gland and tends to occur as a solitary facial lesion. We report a 66-year-old woman with multiple, cystic lesions on her face. Histopathology revealed cystic spaces lined by a row of secretory cells showing decapitation secretion. We emphasize the multiple character of the case and discuss its distinction from so-called eccrine hidrocystomas.

Aged↗
PubMed1993

Changes in the repertoire of peptides bound to HLA-B27 subtypes and to site-specific mutants inside and outside pocket B.

HLA-B27 subtypes share many structural features, including their pocket B, which interacts with a conserved Arg residue at the second position of B*2705-bound peptides. Subtypes differ among each other at other locations in the peptide binding site. In this study, metabolic labeling and radiochemical pool sequencing were used to address the following issues: (a) presence of the Arg 2 (R2) motif among peptides bound to the various HLA-B27 subtypes; (b) influence of mutations inside and outside pocket B on this motif; and (c) the degree of similarity among the peptide pools bound to the various B27 subtypes. Sequencing of Arg-labeled peptide pools extracted from B*2701 to B*2706, and from two site-directed mutants of B*2705 with changes outside pocket B, indicated that all of these molecules bind peptides with Arg at position 2. Peptides from several mutants with changes altering the structure of pocket B, and from one mutant at the pocket B rim, also retained the R2 motif. However, this was absent in the peptide pool extracted from the M45 mutant, in which the negative charge of pocket B, conferred to HLA-B27 by Glu45, was canceled. These results indicate that alterations outside pocket B, and even disruption of the network of hydrogen bonds that stabilizes Arg binding in pocket B, do not impair binding of peptides bearing the R2 motif, but a nonconservative substitution at position 45 does. As a substantial fraction of anti-B*2705 cytotoxic T lymphocyte (CTL) clones crossreact with the M45 mutant (Villadangos, J., B. Galocha, D. López, V. Calvo, and J. A. López de Castro. 1992. J. Immunol. 149:505) this result suggest that determinant mimicry by nonidentical peptides may frequently account for unexpected CTL crossreactions. Metabolic labeling with various other amino acids and radiochemical sequencing revealed similarities, but also substantial differences, among the peptide pools from the various HLA-B27 subtypes. This strongly suggests that many peptides bind to multiple subtypes, but significant subsets of peptides bound to a given HLA-B27 subtype do not bind to other subtypes or do so with greatly altered efficiency. These results indicate the importance of polymorphism outside pocket B in modulating peptide binding to HLA-B27.

Amino Acid Sequence↗
PubMed1992

Peptide-presenting similarities among functionally distant HLA-B27 subtypes revealed by alloreactive T lymphocytes of unusual specificity.

Functional dissection of HLA-B27 subtypes using alloreactive or B27-restricted CTL has shown that the structurally related B*2704 and B*2706 are the most distant subtypes relative to the prototype B*2705. In particular, previous studies have failed to find anti-B*2705 CTL cross-reacting with B*2704 or B*2706. Such failure can be accounted for by the drastic effect on T cell recognition of the change at residue 152 in both subtypes relative to B*2705, as established with site-directed mutants. B*2704 and B*2706 are also related in ethnic distribution, as they are restricted to Orientals, jointly being the predominant HLA-B27 subtypes in this population. As far as it is known, there are no differences relative to B*2705 in their linkage to ankylosing spondylitis. In our study, 5 of 13 examined anti-B*2705 limiting dilution CTL lines from a particular HLA-B27- individual were shown to crossreact with B*2704, B*2706 or both. The monoclonal nature of this cross-reaction was established by cold target competition analysis. This result demonstrates that the apparent differences in T cell antigenicity among anti-B27 subtypes are strongly influenced by the responder individual, as the spectrum of clonal specificities in anti-B27 responses may show significant differences among unrelated responders. Fine specificity differences among the cross-reactive CTL allowed unambiguous functional distinction between B*2704 and B*2706. The molecular basis of such cross-reactivity was examined by correlating CTL reaction patterns with the structure of both subtypes, which differ only by two residues located in the beta-pleated sheet bottom of the peptide binding site, and with site-directed mutants mimicking HLA-B27 subtype polymorphism. The results suggest that: 1) distinct peptides are involved in the allospecific epitopes recognized by the various crossreactive CTL, and 2) B*2704, B*2706, and B*2705 differ in their peptide-presenting specificity, but can present some identical or structurally similar peptides.

Clone Cells↗
PubMed1992

[Herpes simplex virus infection in pregnancy: epidemiologic, diagnostic and therapeutic data. An unusual case of HSV-1 in monozygotic twins].

The Authors report a case of two pre-term monocorial twins affected by HSV-1 infection (Herpes Simplex Virus type 1), with generalized sepsis and involvement of the central nervous system (CNS), born by mother with primary infection who presented a typical vesicular eruption a week before delivery. As the HSV-1 was a disseminated type and the CNS was involved in both the twins, the diagnosis was based on clinical and laboratory findings (specific IgM and IgG) and on the use of Delpech-Lichtblau antibody liquoral index, a significant results both in the first and the second twin. Intensive care and early specific treatment with Acyclovir allowed a slow but progressive improvement of the twins' clinical picture. The antibody liquoral index may therapy of the viral sepsis cases involving the CNS, more than the cultural or antigen isolation of the treated virus.

Acyclovir↗