[Clinical significance of tumor content of epidermal growth factor receptor in breast cancer]

OBJECTIVE

To determine the content of epidermal growth factor receptor (EGFR) using a radioligand method in breast cancer and to analyze the relationship between the EGFR levels and the characteristics of patients and tumors. Prognostic significance was also analyzed.

MATERIAL AND METHODS

EGFR was measured by a single point radioligand assay in 265 invasive breast carcinomas tissues. In addition, estrogen and progesterone receptors (ER and PR) were measured by enzymatic immunoassays. We analyze the relationship of EGFR levels with the different clinico-pathologic parameters.

RESULTS

EGFR levels in breast carcinomas varied widely (0.1 to 403) with a median at 4 fmol/mg prot. The significantly higher concentrations of EGFR were detected in patients under 60 years old (p = 0.042), undifferentiated tumors (p = 0.04), and carcinomas with negative ER and PR (p < 0.019 y p < 0018, respectively). In addition, there was a negative correlation between EGFR and the ER and PR levels (p < 0.05). EGFR levels did not show any relationship with the patient's prognosis.

CONCLUSIONS

In addition, intratumoral levels of EGFR in breast carcinomas vary widely and the highest concentrations are associated with the most aggresive characteristics of the tumor.

[Fiberoptic bronchoscopy, 3-D reconstruction of the airway and virtual bronchoscopy in patients with airway malformations. Preliminary report]

Bronchoscopy is the diagnostic gold standard in patients with airway malformations. Helical CT scan has produced studies such as virtual bronchoscopy or 3-D reconstruction of the airway. The purpose of this study is to analyze the correlation between fiberoptic bronchoscopy, virtual bronchoscopy and 3-D reconstruction of the airway in patients with airway malformations.

METHODS

From January 2001 to March 2002 we evaluated the airway of 17 patients with airway malformations by means of a diagnostic protocol consisting on fiberoptic bronchoscopy, and Helical CT scan with 3-D reconstruction of the airway and virtual bronchoscopy. The radiologist had no access to bronchoscopic information. Age at study, associated cardiovascular anomalies, indications, localization, degree of diagnostic concordance, etiology and influence in treatment were analyzed.

RESULTS

20 studies were done to 17 patients whose mean age was 1.64 +/- 0.48 years (7 days-7 years). Twelve patients had associated anomalies of the aorta, pulmonary arteries or supraortic vessels. Excellent concordance was obtained in 13 cases (65%), good in 6 (30%) and poor in one (5%). 3-D reconstruction of the airway and adjacent vascular structures provided additional information in 14 cases (70%): in 3 exact length of the tracheal lesion and in 11 defined the cause of the compression. In all the cases, absolute concordance in localization was obtained. CT scan information modified treatment in 6 patients (35%). In 7 patients with associated vascular anomalies, no further image studies were done, confirming the anatomy concordance during surgery.

CONCLUSIONS

3-D reconstruction of the airway and virtual bronchoscopy are excellent diagnostic tools in patients with airway malformations, and contribute to define the etiology, length and diameter of the lesion. Excellent diagnostic correlation was obtained between analogic and virtual bronchoscopies, although further multicentric studies should be conducted.

Apolipoprotein D expression in metastasic lymph nodes of breast cancer

BACKGROUND

Apolipoprotein D is a glycoprotein of the human plasma whose functional role remains unclear. On the other hand, this protein is also produced by breast carcinomas and is positively associated with a favorable outcome of patients. However, none study has focused on metastasic lesions.

AIM

To analyze apolipoprotein D expression in breast cancer patients and their synchronous metastasic axillary lymph nodes.

METHODS

We analyzed by immunohistochemical assay both, the tumoral expression of apolipoprotein D in primary tumors and in their synchronous metastasic axillary lymph nodes of 30 node-positive breast cancer patients.

RESULTS

Of the primary tumors, 28 (93.3%) showed a positive immunostaining for apolipoprotein D, although there was wide variability immunostaining values. On the other hand, 16 (53.3%) patients showed a positive immunostaining for the protein in their tumoral lymph nodes. In addition, there was a significant positive relationship between the tumoral expression of apolipoprotein D in primary tumors and metastasic lymph nodes (P < 0.05). However, only immunostaining values of the protein in primary tumors achieve statistical signification (P < 0.05) as prognostic factor of favorable evolution to predict overall survival from patients.

CONCLUSIONS

Apolipoprotein D is also expressed in metastasic lymph nodes of breast carcinomas, but with a different pattern of immunostaining and less clinical significance than in primary tumors.

Asymmetric synthesis of succinic semialdehyde derivatives

The nucleophilic Michael addition of 2-(diphenylmethoxymethyl)-1-methyleneamino pyrrolidine 1Dto prochiral aliphatic and aromatic alkylidene malonates 2 takes place in the presence of MgI(2) to afford the corresponding Michael adducts 3 in excellent yields and good selectivities. In the aromatic series, optically pure (de > 98%) major diastereomers (S,S)-3 were isolated in good yields (77-93%) after chromatographic separation. Direct, racemization-free BF(3).OEt(2)-catalyzed thiolysis of compounds 3 afforded dithioacetals 7. These compounds were transformed into malonates 8 and succinic semialdehyde derivatives 9 by Raney Nickel mediated desulfuration or decarboxylation, respectively.

Proteomics as a tool for the investigation of seafood and other marine products

The state-of-the-art and future trends of the application of proteomics to seafood and other marine products are reviewed. Consumers' demands for seafood products have increased in the recent years and this situation has underlined the need to guarantee the safety, traceability, authenticity, and health benefits of such products. The increasing presence of commercially available aquaculture products has also prompted the seafood industry to face newer challenges. In this sense, a review of the present status and perspectives of the application of proteomics in the development of newer biotechnology products of marine origin is given.

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.

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.

[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.

Evidence of saxitoxin derivatives as causative agents in the 1997 mass mortality of monk seals in the Cape Blanc Peninsula

Monk seals in Cape Blanc (Western Sahara coast) suffered a mass mortality during May-July 1997 which was attributed to a morbillivirus. High performance liquid chromatography (HPLC) analysis on tissues of seals killed during the outbreak and on related fauna showed peaks with retention times coincident with those of some saxitoxin derivatives but their identity was not proved. Here we present results of further HPLC analyses that unambiguously prove the identity of these toxins by mass spectrometry (MS), supporting the hypothesis that this mortality of monk seals was caused by biotoxins rather than by a morbillivirus.

[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.

[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.

Asymmetric Michael addition of formaldehyde N,N-dialkylhydrazones to alkylidene malonates

Enantiopure formaldehyde N,N-dialkylhydrazones 1 smoothly react with prochiral alkylidene malonates 2 in the presence of MgI2 to afford the corresponding Michael adducts 3 in excellent yields and good diastereoselectivities; direct racemization-free BF3.OEt2-catalyzed thiolysis of the hydrazone C=N bond affords the corresponding dithioketals 7 in optically pure or enantiomerically enriched form.

[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.

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.

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.

Characterization of rpoB gene mutations in rifampicin resistant Mycobacterium tuberculosis strains isolated from pulmonary tuberculosis patients at 5 Mexican public hospitals

OBJECTIVE

To characterize the rpoB gene mutations of the rifampicin-resistant M. tuberculosis strains isolated in pulmonary tuberculosis patients from Mexico.

MATERIAL AND METHODS

Thirty-seven clinical M. tuberculosis isolates cultured on Löwenstein-Jensen media and obtained from consecutive tuberculosis patients in 5 public hospitals were analyzed by PCR and the INNO-LiPA Rif TB for amplification and detection of mutations associated with rifampicin resistance, respectively.

RESULTS

Twenty-three out of 37 isolates (62.2%) were found to be wild type (rifampicin susceptible), while 14 isolates (37.8%) contained mutations associated with rifampicin resistance. Seven out of the 37 isolates (18.9%) had a delta S1 mutation, in the nucleotide position number 511; one (2.7%) had a R4b mutation, in nucleotide H526D; five (13.5%) contained a R5 mutation, in nucleotide S531L; and one (2.7%) showed a double mutation delta S1/R4b.

CONCLUSION

According to the marker used (rifampicin resistance), at least five different strains of M. tuberculosis circulate among pulmonary tuberculosis patients in Mexico. rpoB gene mutations associated with rifampicin resistance are common in Mexico. A single mutation in nucleotide 511 was the most frequently observed, followed by single mutations in nucleotides S531L and H526D.

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.

Experimental and ab Initio Equilibrium Structure and Harmonic Force Field of 1,2,5-Oxadiazole

The equilibrium structure of 1,2,5-oxadiazole has been calculated ab initio at the CCSD(T) level using a polarized valence quadruple zeta basis set. The harmonic force field has also been calculated at the MP2/cc-pVTZ, B3LYP/6-311++G(3df, 2pd), and B3LYP/cc-pVQZ levels. These force fields have been subsequently scaled and further refined by fitting them to the experimental values of the vibrational fundamentals of three isotopomers and the centrifugal distortion constants of the parent molecule. The specific refinement of those scaled force constants particularly sensitive to the experimental data set was decisive for obtaining a more reliable harmonic potential. The resulting force fields are presented and used, together with the ground state rotational constants, to calculate an r(z) structure. The experimental r(0), r(s), and r(m) structures have also been determined. The different results have been compared and it is concluded that the ab initio structure is a good approximation of the equilibrium structure. It is also shown that the magnetic correction is not negligible, particularly for the inertial defect. Another interesting conclusion is that the anharmonicity of the C-H stretching might be unusually small. Copyright 2001 Academic Press.

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.

[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.