[Clinical utility of serous tumoural markers].
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Biomarkers, Tumor↗
Biomedical subjects
J Vázquez
Publications and source records attributed to J Vázquez.
Neutrophilic pustulosis and ulcerative colitis.
Neutrophilic pustulosis is currently considered as a part of the spectrum of Sweet's syndrome, and has been associated with inflammatory bowel disease and several other diseases. We report the case of a 34-year-old male who had been suffering from ulcerative colitis (UC) for several years and who experienced the manifestation of a pustular eruption on both forearms and the abdominal wall during an exacerbation of his bowel disease. Both processes were controlled with steroids per os. The histological picture showed an inflammatory infiltrate composed mainly of neutrophils with scattered neutrophilic epidermal abscesses. Certain distinct clinical and histological characteristics have been described as diagnostic of the pustular eruption of UC. This picture should be included in the spectrum of the neutrophilic dermatosis, in our case associated with an ulcerative colitis. This is a well documented clinical and histologic case report of a recognized association of inflammatory pustulosis in the course of ulcerative colitis.
Adult↗
The phosphorylation state of threonine-220, a uniquely phosphatase-sensitive protein kinase A site in microtubule-associated protein MAP2c, regulates microtubule binding and stability.
Phosphorylation of microtubule-associated protein 2 (MAP2) has a profound effect on microtubule stability and organization. In this work a consensus protein kinase A (PKA) phosphorylation site, T(220), of juvenile MAP2c is characterized. As confirmed by mass spectrometry, this site can be phosphorylated by PKA but shows less than average reactivity among the 3.5 +/- 0.5 phosphate residues incorporated into the protein. In contrast, T(220) is uniquely sensitive to dephosphorylation: three major Ser/Thr protein phosphatases, in the order of efficiency PP2B > PP2A(c) > PP1(c), remove this phosphate group first. MAP2c specifically dephosphorylated at this site binds and stabilizes microtubules stronger than either fully phosphorylated or nonphosphorylated MAP2c. Phosphorylation of this site also affects proteolytic sensitivity of MAP2c, which might represent a further level of control in this system. Thus, the phosphorylation state of T(220) may be a primary determinant of microtubule function.
Amino Acid Sequence↗
[Analysis of the cytosolic content of the pS2 protein in breast cancer].
OBJECTIVE: To analyze pS2 cytosolic levels in breast carcinomas and their correlation with different clinical characteristics of the patients and their tumours. MATERIAL AND METHODS: Cytosolic pS2 levels were measured by radioimmunometric assay in tumours from 168 breast cancer patients. RESULTS: The pS2 values ranged from 0 to 251 ng/mg protein (mean SD: 21.8 38.1; median: 7.9 ng/mg protein). These protein levels were significantly (p < 0.05) higher in premenopausal patients (27.6 45.2) than in postmenopausal patients (19.5 33.8). Intratumour pS2 levels were also significantly (p < 0.05) correlated with histologic grade of the tumours, and were higher in well diferentiated tumours (grade I: 28.8 42.8) than in moderately differentiated tumours (grade II: 19.7 35.6) and than in poorly differentiated tumours (grade III: 18.9 37.3). Similarly, significant differences in pS2 content were found between positive estrogen receptor (ER) tumours and ER-negative tumours (29.1 46.5 vs 11.3 15.9, respectively; p<0.0001), as well as between positive progesterone receptor (PR) tumours and PR-negative tumours (29.1 49.8 vs 15.3 21.5, respectively; p < 0.05). CONCLUSIONS: The results suggest that pS2 may be a useful prognostic marker in breast cancer, and may also be useful to identify patients who are likely to benefit from hormone therapy.
Adult↗
[Treatment of vestibular fistulas in older girls].
The vestibular fistula is the anorectal malformation more frequent in females. In this congenital anomaly the anus is located in the vaginal vestibule, having the rectum a common wall with the vagina. With the posterior sagittal approach described by Alberto Peña it changes the treatment of this anorectal malformation, contributing to the possibility of an aesthetic and functional improvement. From 1996 we have operated on 6 girls with ages included between 6 and 22 years (mean of 11 years) that presented a vestibular fistula. Five cases had been operated on in the neonatal period of vestibular fistula carrying out "cut-back", and a case had been operated on for cloaca syndrome. It was carried out in all of them, posterior sagittal approach disecting the rectum, separating it from the vagina and placing it in the sphincter. In a case a colostomy was carried out and in the other five were carried out intestinal cleaning, maintaining absolute diet and postoperative total parenteral nutrition. The evolution has been favorable in all the cases. the functionality of the neo-anus in terms of continence is absolutely normal, presenting an excellent aesthetic aspect. We believe that the posterior sagittal approach is suitable as surgical treatment of the vestibular fistula. The aesthetic improvement and the satisfaction of our patients motivates us to the realization of this technique that also allows us to correct in only one surgical act associated vaginal malformations.
Abnormalities, Multiple↗
[Bronchoscopies in neonatal intensive care units: safety and efficiency].
The aim of our study is to asses the risks and complications in bronchoscopies at Neonatal Intensive Care Units (NICU). Between 1991 and 1999, we performed 142 bronchoscopies at the NICU. The mean age was 1.6 +/- 1.4 months (2 days-6 months) and mean weight was 2.5 +/- 1 kg (530 g-4.7 kg). We analysed the complications, arterial oxygen saturation and inspired oxygen fraction (FiO2) during bronchoscopy and we compared them related to weight, type of anesthesia and type of bronchoscope used. Mean basal saturation was 92 +/- 8.9% and end saturation was 92.8 +/- 10%. The basal FiO2 was 0.5 +/- 0.3 (0.21-1). There were more complications in patients weighting less than 1500 g and in those procedures made with rigid bronchoscopy (p < 0.05). There were no differences according to the anesthesia. Children who weight fewer than 1500 g and those who underwent rigid bronchoscopy suffered a descent in arterial oxygen saturation and needed higher FiO2 (p < 0.05). Bronchoscopy is a very useful technique and it is well tolerated in neonatal patients. We conclude that flexible fiberoptic bronchoscopy is safer than the rigid bronchoscopy, specially in children fewer under 1500 g.
Bronchoscopy↗
[Respiratory deadspace and compliance measurements in neonates with congenital diaphragmatic hernia].
The mortality rate of infants with congenital diaphragmatic hernia (CDH) remains high, despite clinical improvements. Many attempts have been made to find accurate and reliable predictors of outcome. Deadspace (Vd/Vt) and dynamic compliance (DC) measured by single breath CO2 analysis may be useful to evaluate pulmonary function and perfusion. In the present study we analyse both parameters in patients with CDH. Nine patients with CDH were included for Vd/Vt and DC study. Measurements of arterial blood gases (pH, PO2, pCO2) were obtained, oxygenation index and alveolo-arterial difference calculated at diagnosis, preoperatively and postoperatively. Vd/Vt and DC were measured at the same moments by analysis of the CO2 espirogram. Statistical analysis was performed using Fisher exact test, ANOVA and Mann Whitney and Chi-square. The Vd/Vt was significant lower for the group of patients who survived (0.39 +/- 0.07 vs 0.64 +/- 0.14, p = 0.038). DC was significantly higher in the survivors group (1.39 +/- 0.30 vs 0.5 +/- 0.07, p = 0.011). The analysis of the evolutive Vd/Vt and DC (initial and preoperative) showed significant differences within both groups. Respiratory deadspace can be easily quantified in neonates with congenital diaphragmatic hernia providing an important insight regarding the efficiency of the airway-alveolus and its relationship to pulmonary blood flow. Vd/Vt and DC measurement constitute a reliable method to predict outcome in patients with CDH.
Hernia, Diaphragmatic↗
Glutathionylation of the p50 subunit of NF-kappaB: a mechanism for redox-induced inhibition of DNA binding.
The cellular redox status can modify the function of NF-kappaB, whose DNA-binding activity can be inhibited by oxidative, nitrosative, and nonphysiological agents such as diamide, iodoacetamide, or N-ethylmaleimide. This inhibitory effect has been proposed to be mediated by the oxidation of a conserved cysteine in its DNA-binding domain (Cys62) through unknown biochemical mechanisms. The aim of this work was to identify new oxidative modifications in Cys62 involved in the redox regulation of the NF-kappaB subunit p50. To address this problem, we exposed p50, both the native form (p50WT) and its corresponding mutant in Cys62 (C62S), to changes in the redox pair glutathione/glutathione disulfide (GSH/GSSG) ratio ranging from 100 to 0.1, which may correspond to intracellular (patho)physiological states. A ratio between 1 and 0.1 resulted in a 40-70% inhibition of the DNA binding of p50WT, having no effect on the C62S mutant. Mass spectrometry studies, molecular modeling, and incorporation of (3)H-glutathione assays were consistent with an S-glutathionylation of p50WT in Cys62. Maximal incorporation of (3)H-glutathione to the p50WT and C62S was of 0.4 and 0.1 mol of (3)H-GSH/mol of protein, respectively. Because this covalent glutathione incorporation did not show a perfect correlation with the observed inhibition in the DNA-binding activity of p50WT, we searched for other modifications contributing to the maximal inhibition. MALDI-TOF and nanospray-QIT studies revealed the formation of sulfenic acid as an alternative or concomitant oxidative modification of p50. In summary, these data are consistent with new oxidative modifications in p50 that could be involved in redox regulatory mechanisms for NF-kappaB. These postranslational modifications could represent a molecular basis for the coupling of pro-oxidative stimuli to gene expression.
Amino Acid Sequence↗
The Cys-67 residue of HLA-B27 influences cell surface stability, peptide specificity, and T-cell antigen presentation.
Cys-67 of HLA-B27 is located in the B pocket, which determines peptide-binding specificity. We analyzed effects of the Cys-67 --> Ser mutation on cell surface expression, peptide specificity, and T-cell recognition of HLA-B*2705. Surface expression was assessed with antibodies recognizing either native or unfolded HLA proteins. Whereas native B*2705 molecules predominated over unfolded ones, this ratio was reversed in the mutant, suggesting lower stability. Comparison of B*2705- and Cys-67 --> Ser-bound peptides revealed that the mutant failed to bind approximately 15% of the B*2705 ligands, while binding as many novel ones. Two peptides with Gln-2 found in both B*2705 and Cys-67 --> Ser are the first demonstration of natural B*2705 ligands lacking Arg-2. Other effects of the mutation on peptide specificity were: 1) average molecular mass of natural ligands higher than for B*2705, 2) bias against small residues at peptide position (P) 1, and 3) increased P2 permissiveness. The results suggest that the Cys-67 --> Ser mutation weakens B pocket interactions, leading to decreased stability of the mutant-peptide complexes. This may be partially compensated by interactions involving bulky P1 residues. The effect of the mutation on allorecognition was consistent with that on peptide specificity. Our results may aid understanding of the pathogenetic role of HLA-B27 in spondyloarthropathy.
Amino Acid Substitution↗
Characterization and partial sequencing of species-specific sarcoplasmic polypeptides from commercial hake species by mass spectrometry following two-dimensional electrophoresis.
The Merluccidae family comprises marine species, some of them of high commercial value and others less appreciated, whose commercialization in Europe under the generic name of "hake" is highly remarkable. The potential of proteomics was employed in this study with the aim of achieving the differential characterization of five different hake species: Merluccius merluccius (European hake), M. australis (Southern hake), M. hubbsi (Argentinian hake), M. gayi (Chilean hake), and M. capensis (Cape hake), some of them very closely related. Species-specific polypeptides were observed for the five hake species studied in isoelectric focusing (IEF) and/or two-dimensional electrophoresis (2-DE) high-resolution gels. The peptide mass maps of two polypeptide groups, previously selected by 2-DE analysis as potentially species-specific, were obtained by "in-gel" tryptic digestion, followed by matrix assisted laser desorption/ ionization-time of flight-mass spectrometry (MALDI-TOF-MS). Analysis of group A polypeptides (with pI in the range of 5.0-5.5 and molecular mass of 17 kDa), allowed the differential classification of the hake species into two groups: the East Atlantic coast group and the West Atlantic coast group. Moreover, the peptide mass-maps from the heat-resistant parvalbumin fraction (pI below 4.5; molecular mass <12 kDa) allowed the detection of a peptide characteristic of M. australis not present in the other four hake species tested. A specific 17 kDa protein from M. merluccius was also partially sequenced by nanospray-ion trap-tandem MS, revealing a high homology with rat nucleoside diphosphate kinase A (NDKA). This work opens the way to the application of proteomics to the differential characterization of commercial hake species at the molecular level.
Amino Acid Sequence↗
Lysozyme expression by breast carcinomas, correlation with clinicopathologic parameters, and prognostic significance.
BACKGROUND: Here we evaluate the expression and prognostic value of lysozyme, a milk protein that is also synthesized by a significant percentage of breast carcinomas, in women with breast cancer. METHODS: Lysozyme expression was examined by immunohistochemical methods in a series of 177 breast cancer tissue sections. Staining was quantified by using the HSCORE system, which considers both the intensity and the percentage of cells staining at each intensity. The prognostic value of lysozyme was retrospectively evaluated by multivariate analysis that took into account conventional prognostic factors. RESULTS: A total of 126 of 177 carcinomas (69.4%) stained positive for this protein, but there were clear differences among them with regard to the intensity and percentage of stained cells. Lysozyme values were higher in well-differentiated and moderately differentiated tumors than in poorly differentiated tumors (P < .05). Similarly, lysozyme levels were higher in small and node-negative tumors than in large and node-positive tumors (P < .05). Moreover, results indicated that low lysozyme content predicted shorter relapse-free survival and overall survival (P < .005). Separate Cox multivariate analysis in subgroups of patients as defined by node status showed that lysozyme expression was an independent prognostic factor able to predict both relapse-free survival and overall survival in node-negative patients (P < .05). CONCLUSIONS: Tumoral expression of lysozyme is associated with lesions of favorable evolution in breast cancer. This milk protein may be a new prognostic factor in patients with breast cancer.
Adult↗
[Polyps of the biliary tract: is their preoperative diagnosis possible?].
Bile duct polyps are a very uncommon cause of obstructive jaundice. We present our experience of three patients diagnosed in the last 10 years. Initial presentation usually takes the form of obstructive jaundice associated with abdominal pain, which simulates biliary lithiasis. The diagnosis is usually surgical. Although in some cases radiological studies and endoscopic retrograde cholangiopancreatography (ERCP) may sometimes detect bile duct polyps, exact diagnosis before surgery is very unusual. The radiological signs that suggest the existence of a bile duct polyp in the ERCP seem to be the presence of repletion defects, fixed unilaterally to the biliary conduit, without meniscus and without circumferential stenosis of the affected conduit. The most frequently found polyps are fibroinflammatory, and less frequently adenomatous.
Adult↗
Cutaneous T-cell lymphoma presenting as disseminated, pigmented, purpura-like eruption.
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Ficusin↗
A quantum mechanics/molecular mechanics study of the highly enantioselective addition of diethylzinc to benzaldehyde promoted by (R)-2-piperidino-1,1,2-triphenylethanol.
The enantioselective addition of diethylzinc to benzaldehyde mediated by (R)-2-piperidino-1,1,2-triphenylethanol has been studied with the IMOMM procedure, using a RHF description for the quantum mechanical part of the calculation and the mm3(92) force field for the molecular mechanics part. Both the sign and the value of the observed enantioselectivity are well reproduced by the calculations, the relative energies of the four possible transition states being as follows: anti-Si (0.0 kcal.mol(-)(1)), syn-Re (2.7 kcal. mol(-)(1)), anti-Re (4.7 kcal.mol(-)(1)), syn-Si (5.9 kcal. mol(-)(1)). These energies show a perfect correlation with the bond distance in the transition state between zinc and the methylene unit of the ethyl group being transferred.
Benzaldehydes↗
Identification of amino acid residues of transcription factor AP-2 involved in DNA binding.
AP-2 is a cell-type specific, developmentally regulated transcription factor which has been described as a critical regulator of gene expression during vertebrate development and embryogenesis. Although the overall domains of this factor necessary for their activity have been identified, the exact identity of AP-2 amino acid residues responsible for its interaction with the DNA structure has not yet been described. Here, we describe the identification of a region of AP-2 which was protected by an oligonucleotide probe containing its binding site from trypsin digestion, monitored by peptide mapping by MALDI-TOF mass spectrometry. Furthermore, we analyzed the relative in vitro DNA-binding activity, the stimulatory potency on the AP-2-dependent APOE promoter, as well as the ability to inhibit the effect of the wild-type protein of each one of a set of single-site substitution AP-2 mutants spanning the identified region. Taken together, our data clearly demonstrate that the region between amino acid residues 252-260 of AP-2 is essential for its DNA-binding activity. Particularly, the individual substitution in any of the residues 253, 254, 255, 257 or 260 is sufficient for completely abolishing the interaction with DNA and the stimulation of APOE promoter activity. These results indicate a crucial role of this region in the formation of an active DNA-binding domain and strongly suggest that these residues provide direct contacts with the DNA structure at the AP-2 binding site.
Amino Acid Sequence↗
An N-acetylated natural ligand of human histocompatibility leukocyte antigen (HLA)-B39. Classical major histocompatibility complex class I proteins bind peptides with a blocked NH(2) terminus in vivo.
Sequence-independent interactions involving the free peptidic NH(2) terminus are thought to be an essential feature of peptide binding to classical major histocompatibility complex (MHC) class I proteins. Challenging this paradigm, a natural Nalpha-acetylated ligand of human histocompatibility leukocyte antigen (HLA)-B39 was identified in this study. It matched the NH(2)-terminal sequence of two human helicases, was resistant to aminopeptidase M, and was produced with high yield from a synthetic 30 mer with the sequence of the putative parental protein by the 20S proteasome. This is the first reported natural ligand of classical MHC class I antigens that has a blocked NH(2) terminus.
Acetylation↗
Limited diversity of peptides related to an alloreactive T cell epitope in the HLA-B27-bound peptide repertoire results from restrictions at multiple steps along the processing-loading pathway.
The influence of various factors along the processing-loading pathway in limiting the diversity of HLA-B27-bound peptides around a core protein sequence was analyzed. The C5 proteasome subunit-derived RRFFPYYV and RRFFPYYVY peptides are natural B*2705 ligands. The octamer is an allospecific CTL epitope. Digestion of a 27-mer fragment of C5 revealed that both ligands are generated from this precursor substrate with the 20S proteasome in vitro in a ratio comparable to that in the B*2705-bound peptide pool. The C5 sequence allowed to derive a nested set of six additional peptides with 8-11 residues containing the core octamer sequence and the Arg2 motif of HLA-B27, none of which was found in the B27-bound pool. Together, low proteasomal yield, disfavored TAP-binding motifs, and low affinity for B*2705 accounted for the absence of four of the six peptides. The two remaining differed from the natural octamer or nonamer ligands only by an additional N-terminal Ser residue. Their stability in complex with B*2705 was lower than the respective natural ligands, raising the possibility that N-terminal trimming might have favored a shift toward the more stable peptides. The results suggest that the B*2705-bound peptide repertoire has a highly restricted diversity around a core alloantigenic sequence. This is not explained by a single bottleneck feature, but by multiple factors, including proteasomal generation, TAP-binding motifs, MHC-binding efficiency, and perhaps optimized stability through N-terminal trimming. Tapasin-dependent restrictions, although not excluded, were not required to explain the absence in vivo of the particular peptide set in this study.
Amino Acid Sequence↗
Identification of phosphorylation sites in proteins by nanospray quadrupole ion trap mass spectrometry.
A method is described for identifying serine phosphorylation sites in proteins, based on conventional (32)P labeling followed by electrophoretic separation, 'in-gel' digestion with a protease, peptide extraction, reversed-phase high-performance liquid chromatographic separation and collection and off-line analysis of the radioactive fractions by nanospray ion trap mass spectrometry. The method was successfully applied to the identification of three phosphorylation sites in two proteins which were subjected to in vitro phosphorylation under physiological conditions. Different combinations of the various scanning modes of the ion trap, including high-resolution, multiple subfragmentation (or MS(n)) and fast scan analysis, were employed to identify the phosphopeptides, determine their sequence and localize the exact site of phosphorylation. 'Blind' fragmentation using fast scans was used to analyze a phosphopeptide which was undetectable in other scanning modes. The sequence, phosphorylation site and double cysteine modification of the potassium adduct of a peptide containing 35 residues were also determined by multiple fragmentation. The results not only support the validity of the proposed method for routine identification of phosphorylation sites, but also demonstrate the exceptional capability of off-line ion trap mass spectrometry in combination with nanospray ionization for performing very detailed studies on the structure of peptides.
Chromatography, High Pressure Liquid↗