Verification of absorbed dose rates in reference beta radiation fields: Measurements with an extrapolation chamber and radiochromic film.

Beta Secondary Standard 2 (BSS 2) provides beta radiation fields with certified values of absorbed dose to tissue and the derived operational radiation protection quantities. As part of the quality assurance, the reliability of the CDTN BSS2 system was verified through measurements in the 90Sr/90Y and 85Kr beta radiation fields. Absorbed dose rates and their angular variation were measured with a 23392 model PTW extrapolation chamber and with Gafchromic radiochromic films on a PMMA slab phantom. The feasibility of using both methods was analyzed.

CIEMAT EXTERNAL DOSIMETRY SERVICE: ISO/IEC 17025 ACCREDITATION AND 3 Y OF OPERATIONAL EXPERIENCE AS AN ACCREDITED LABORATORY.

In 2008, the CIEMAT Radiation Dosimetry Service decided to implement a quality management system, in accordance with established requirements, in order to achieve ISO/IEC 17025 accreditation. Although the Service comprises the approved individual monitoring services of both external and internal radiation, this paper is specific to the actions taken by the External Dosimetry Service, including personal and environmental dosimetry laboratories, to gain accreditation and the reflections of 3 y of operational experience as an accredited laboratory.

Membrane surface functionalization via theophylline derivative coating and streptavidin immobilization.

Poly(vinylidene fluoride) (PVDF) and regenerated cellulose (RC) membranes were surface-modified by the adsorption of one adenosine receptor antagonist: the theophylline-oligo(ethylene glycol)-alkene derivative, Theo1. Surface modification was carried out by immersion of the membrane in a dichloromethane solution of Theo1 (PVDF+Theo1 and RC+Theo1 samples). Membrane surfaces with partial coverage by theophylline and/or its inclusion in the membrane structures were studied by X-ray photoelectron spectroscopy (XPS), solid-state nuclear magnetic resonance (SNMR), impedance spectroscopy (IS) and contact angle (CA) measurements. The Theo1 orientation was inferred from the data. Streptavidin (SA) was immobilized onto the membrane/Theo1 hybrid material. The protein-theophylline Theo1 interaction was visualized with bright field microscopy (BFM).

Feasibility of EBT Gafchromic films for comparison exercises among standard beta radiation fields.

The feasibility of using radiochromic films to verify the metrological coherence among standard beta radiation fields was evaluated. Exercises were done between two Brazilian metrology laboratories in beta fields from (90)Sr/(90)Y, (85)Kr and (147)Pm radiation sources. Results showed that the radiochromic film was useful for field mapping aiming uniformity and alignment verification and it was not reliable for absorbed dose measurements only for (147)Pm beta field.

Pyogenic versus amoebic liver abscesses. A comparative clinical study in a series of 58 patients.

OBJECTIVE: To compare the clinical and epidemiological characteristics of patients with pyogenic liver abscess (PLA) and with amebic liver abscess (AHA) in order to determine the potential factors that may help improve diagnosis and treatment for this disease. MATERIAL AND METHOD: A retrospective study of clinical histories of 45 patients with PLA and 13 with ALA, diagnosed between 1985 and 2005 in Donostia Hospital in San Sebastián. RESULTS: Among the 45 patients with PLA (30 men and 15 women, with a mean age of 61 years and 11 months), more than a half were cholangitic (13 cases) or were of unknown origin (15 cases). In 10 patients, diabetes was considered to be a predisposing condition. Increased ESR (> 30), leukocytosis (> 12,000), fever and abdominal pain were observed in 95.5%, 86.7%, 82.8% and 68.9%, respectively. Twenty-five patients had single abscesses. Abscess and blood cultures were positive in 77.1% and 50% of cases, respectively (44.4% with polymicrobial infection). E. coli and S. milleri were the most commonly found germs. A percutaneous drainage was performed on 22 patients. Mean hospital stay was 27 days, and overall mortality, including that related to concomitant conditions, was 7 of 45 cases.Of the 13 cases of ALA (7 men and 6 women, with mean age of 42,9 years), 2 were locally acquired. Increased AF and GGTP (> 2N), fever, leukocytosis and ESR (> 30) were observed in 92.3, 77, 70 and 61.5% of cases, respectively. There were single abscesses in 10 patients and all except one were located in the right lobe. The serological test for E. histolytica (IFF > or = 1/256) was positive in 100% of cases. A percutaneous drainage was carried out on 6 patients. Mean hospital stay was 18 days and two patients died. CONCLUSIONS: In our series, the clinical parameters suggesting pyogenic origin were: age 50 or older, male gender, diabetes, moderately elevated bilirubin and transaminases. In amoebic cases the associated features were being aged 45 or younger, diarrhoea, and presence of a single abscess in the right lobe. Parasitism by E. histolytica must be considered in the differential diagnosis of liver abscesses, even with no epidemiological clinical history of travel and/or immigration.

Early steps in avian reovirus morphogenesis.

Avian reoviruses are important pathogens that may cause considerable economic losses in poultry farming. Their genome expresses at least eight structural and four nonstructural proteins, three of them encoded by the S1 gene. These viruses enter cells by receptor-mediated endocytosis, and acidification of virus-containing endosomes is necessary for the virus to uncoat and release transcriptionally active cores into the cytosol. Avian reoviruses replicate within cytoplasmic inclusions of globular morphology, termed viral factories, which are not microtubule-associated, and which are formed by the nonstructural protein muNS. This protein also mediates the association of some viral proteins (but not of others) with inclusions, suggesting that the recruitment of viral proteins into avian reovirus factories has specificity. Avian reovirus morphogenesis is a complex and temporally controlled process that takes place exclusively within viral factories of infected cells. Core assembly takes place within the first 30 min after the synthesis of their protein components, and fully formed cores are then coated by outer-capsid polypeptides over the next 30 min to generate mature infectious reovirions. Based on data from avian reovirus studies and on results reported for other members of the Reoviridae family, we present a model for avian reovirus gene expression and morphogenesis.

The avian reovirus genome segment S1 is a functionally tricistronic gene that expresses one structural and two nonstructural proteins in infected cells.

The avian reovirus S1 gene contains three partially overlapping, out-of-phase open reading frames (ORFs) that the highly conserved in all avian reovirus strains examined to date. The three S1 ORFs of the avian reovirus strain S1133 were individually expressed in bacterial cells, and their purified translation products used as antigens to raise specific polyclonal antibodies. With these antibodies we were able to demonstrate that all three S1 ORFs from different avian reovirus strains are translatable in infected cells. Proteins p10 and p17, which are specified by ORF1 and ORF2, respectively, are nonstructural proteins which associate with cell membranes, whereas ORF3 directs the synthesis of protein sigma C, a structural oligomeric protein responsible for cell attachment. While intracellular synthesis of protein sigma C was demonstrated a long time ago and that of protein p10 was reported recently, this is the first time that expression of the S1 ORF2 has been demonstrated experimentally. Thus, the previously reported coding capacity of the avian reovirus genome is now expanded to 14 proteins, of which ten are structural (lambda A, lambda B, lambda C, microA, microB, microBC, microBN, sigma A, sigma B, and sigma C) and four are nonstructural (microNS, sigma NS, p17, and p10). Finally, protein p10, but not p17 or sigma C, induces cell-cell fusion when transiently expressed in mammalian cells, supporting a previously published observation that the polypeptide encoded by the S1 ORF1 plays an important role in the syncytial phenotype displayed by avian reoviruses.

Oligomerization and cell-binding properties of the avian reovirus cell-attachment protein sigmaC.

Avian reovirus protein sigmaC, the viral cell-attachment protein, is a minor component of the outer-capsid shell of the viral particle that is synthesized in small amounts in infected cells. We cloned the sigmaC-encoding ORF in vector pIL-2f, expressed it in Escherichia coli, and partially purified the resulting recombinant protein from inclusion bodies. Rabbit polyclonal antibodies raised against the recombinant protein specifically recognized the viral polypeptide in ELISA, immunoprecipitation, and Western blotting. To study the oligomerization capacity and cell-binding affinity of protein sigmaC, the sigmaC-encoding ORF was also expressed in chicken embryo fibroblasts (CEFs) and in reticulocyte lysates. In all three systems protein sigmaC is expressed as a multimer with identical electrophoretic mobility to the naturally occurring protein. Cell-binding experiments show that both in vitro and in vivo expressed protein sigmaC display affinity for CEF receptors, and this property is exclusively associated with the oligomeric form of the protein. The fact that incubation of CEF cells with the recombinant protein expressed in bacterial cells completely blocks the binding of purified reovirions indicates both that binding of this protein to cells is specific and saturable, and that reovirions and protein sigmaC bind to the same class of cell receptor. Saturation binding experiments, performed with the recombinant protein expressed in E. coli and with purified reovirions, showed that the number of cellular receptor sites (CRSs) for avian reovirus S1133 is 1.8 x 10(4) per CEF cell, whereas the number of cellular receptor units (CRUs) for sigmaC is 2.2 x 10(5) per CEF cell. These results are consistent with previous reports on the binding of mammalian reoviruses.

Possible involvement of the double-stranded RNA-binding core protein sigmaA in the resistance of avian reovirus to interferon.

Treatment of primary cultures of chicken embryo fibroblasts with a recombinant chicken alpha/beta interferon (rcIFN) induces an antiviral state that causes a strong inhibition of vaccinia virus and vesicular stomatitis virus replication but has no effect on avian reovirus S1133 replication. The fact that avian reovirus polypeptides are synthesized normally in rcIFN-treated cells prompted us to investigate whether this virus expresses factors that interfere with the activation and/or the activity of the IFN-induced, double-stranded RNA (dsRNA)-dependent enzymes. Our results demonstrate that extracts of avian-reovirus-infected cells, but not those of uninfected cells, are able to relieve the translation-inhibitory activity of dsRNA in reticulocyte lysates, by blocking the activation of the dsRNA-dependent enzymes. In addition, our results show that protein sigmaA, an S1133 core polypeptide, binds to dsRNA in an irreversible manner and that clearing this protein from extracts of infected cells abolishes their protranslational capacity. Taken together, our results raise the interesting possibility that protein sigmaA antagonizes the IFN-induced cellular response against avian reovirus by blocking the intracellular activation of enzyme pathways dependent on dsRNA, as has been suggested for several other viral dsRNA-binding proteins.

A new double-stranded RNA mycovirus from Botrytis cinerea.

A simple double-stranded RNA mycovirus was detected in a wild-type Botrytis cinerea 55k strain. The virus was located in the fungus cytoplasm as free particles of approximately 28 nm in diameter. The mycovirus possesses a single double-stranded genome segment of 1.8 kilobase pairs (kbp) encapsidated within an isometric protein coat whose main structural component is a polypeptide of 68 kDa. Cells infected with this virus showed an important degree of cellular degeneration.

[Metanephric adenoma. A new embryonal tumor of the kidney]. / Adenoma metanéfrico. Un nuevo tumor embrionario de riñón.

Metanephric adenoma is a kidney tumour first identified in 1988 and classified within the group of nephroblastic tumours. It is described as a benign tumour with no capacity to become malignant or metastatic, predominant in women in a 2:1 ratio relative to men, and which can develop at any point in life. In most cases, it is incidentally found as a result of an abdominal ultrasound study for signs and symptoms unrelated to the kidney. Less commonly it presents with pain, polycythemia, haematuria or palpable mass. The key radiologic sign is calcification, which occurs in a statistically higher proportion than in any other renal neoplasia. From the pathoanatomical point of view, the tumour consists of small acinus separated by acellular stroma resembling the hamartomatous elements of nephroblastomatosis and Wilms' tumour. This paper contributes one case of metanephric adenoma, the first one in the national literature.

Permeabilization of mammalian cells to proteins: poliovirus 2A(pro) as a probe to analyze entry of proteins into cells.

Two hybrid protein molecules containing the poliovirus protease 2A (MBP-2A(pro)) (maltose-binding protein-2A(pro) and MBP-Pseudomonas exotoxin A-2A(pro)) have been constructed and purified. Both hybrid proteins efficiently cleave the translation initiation factor eIF-4G when they are co-internalized into cells with adenovirus particles. Almost no intact eIF-4G can be detected in cells incubated with these proteins following this method. Reovirus infectious subviral particles also promote the delivery of MBP-2A(pro) into cells, although less efficiently than adenovirus particles. None of the other methods employed to permeabilize cells to MBP-2A(pro) achieves the degree of eIF-4G cleavage observed with adenovirus particles. By comparison about 30% of cells electroporated with MBP-2A(pro) still contain intact eIF-4G. More drastic electroporation conditions lead to a significant decrease of cell survival. Osmotic lysis of pinocytic vesicles resulted in 30% of the eIF-4G being cleaved in cells treated in suspension. Delivery of MBP-2A(pro) by pH-sensitive liposomes leads to poor hydrolysis of eIF-4G. Taken together our results indicate that permeabilization of cells with adenovirus particles is the most efficient method for introducing MBP-2A(pro) into cells.

Protein architecture of avian reovirus S1133 and identification of the cell attachment protein.

There are a number of discrepancies in the literature regarding the protein composition of the avian reoviruses. The present study demonstrates that avian reovirus S1133 contains at least 10 proteins (lambdaA, lambdaB, lambdaC, muA, muB, muBC, muBN, sigmaA, sigmaB, and sigmaC). Polypeptides muB, muBC, muBN, sigmaB, and sigmaC are components of the outer capsid layer of the virus, while lambdaA, lambdaB, muA, and sigmaA are core polypeptides. Protein lambdaC is a component of both layers, extending from the inner core to the outer capsid. The minor outer-capsid polypeptide sigmaC is shown to be the cell attachment protein, since it is the only viral polypeptide present in extracts of S1133-infected cells that binds specifically to chicken embryo fibroblasts; furthermore, its binding to avian cells was competitively inhibited by S1133 reovirions but not by mammalian reovirions. Our results also show that sigmaC is an oligomeric protein both in the virion and free in the cytoplasm, and preliminary results suggest that the multimer is made up of three monomeric units.

Intracellular posttranslational modifications of S1133 avian reovirus proteins.

Avian reovirus S1133 specifies at least 10 primary translation products, eight of which are present in the viral particle and two of which are nonstructural proteins. In the work presented here, we studied the covalent modifications undergone by these translation products in the infected cell. The structural polypeptide mu2 was shown to be intracellularly modified by both myristoylation and proteolysis. The site-specific cleavage of mu2 yielded a large carboxy-terminal fragment and a myristoylated approximately 5,500-Mr peptide corresponding to the amino terminus. Both mu2 and its cleavage products were found to be structural components of the reovirion. Most avian reovirus proteins were found to be glycosylated and to have a blocking group at the amino terminus. In contrast to the mammalian reovirus system, none of the avian reovirus polypeptides was found to incorporate phosphorus during infection. Our results add to current understanding of the similarities and differences between avian and mammalian reoviruses.

[Wünderlich syndrome caused by metastatic gastric sarcoma in the kidney. Report of a case]. / Síndrome de Wünderlich por metástasis de sarcoma gástrico en riñón. Aportación de un caso.

Contribution of one case of Wünderlich Syndrome secondary to a simple metastasis to the right kidney from a gastric sarcoma operated three years earlier. Pain, palpable mass on the side and decreased haematocrit were the primary symptoms. Diagnosis was confirmed by Computerized Axial Tomography. The therapeutical approach was radical nephrectomy. At 5 years, this female patient remains alive showing no evidence of tumoral disease in the follow-up controls performed.

[PSA and hormone-refractory period in prostatic cancer]. / PSA y periodo hormonorrefractario del cáncer de próstata.

Study of the characteristics of the hormone-refractory period in 32 patients with disseminated prostate cancer who had achieved a complete response to total androgen suppression, appreciating in all of them a subclinical or asymptomatic stage and a clinical or symptomatic one. The subclinical stage was characterized by raised PSA levels and ranged between 3-35 months; at 12 months 59% of patients had advanced to the symptomatic stage, while at 24 months this percentage is 84%. The clinical stage extends from appearance of symptoms to the patient's death, ranging from 3 to 32 months; at 12 months 41% has died; and 91% at 2 years.

The entry of reovirus into L cells is dependent on vacuolar proton-ATPase activity.

Inhibitors of vacuolar proton-ATPase activity (5 microM bafilomycin A1 or 50 nM concanamycin A) prevented infection by reovirus particles but not by infectious subviral particles (ISVPs). Neither compound affected virus attachment or internalization. However, both compounds potently blocked cleavage of the viral protein mu 1C. Finally, both reovirus particles and ISVPs efficiently translocated the toxin alpha-sarcin to the cytosol during virus entry. Bafilomycin A1 blocked translocation of alpha-sarcin by reovirus particles but not by ISVPs.

Endogenous enzymatic activities of the avian reovirus S1133: identification of the viral capping enzyme.

Avian reovirus S1133 was shown to contain all the enzymatic activities required for the synthesis of mature viral transcripts, including a dsRNA-dependent RNA polymerase, a nucleoside triphosphate phosphohydrolase, an mRNA guanylyltransferase, and two mRNA methyltransferases. The virus used these enzymes both in vitro and in vivo to catalyze the synthesis of viral mRNAs containing a type-1 cap at their 5' ends. Incubation of reovirions with GTP led to the formation of an intermediate structure consisting of GMP bound to the viral core protein lambda 3 through a phosphoamide linkage. The reaction was specific for GTP and required the presence of both Mg2+ and inorganic pyrophosphatase. The GMP moiety can be transferred from the lambda 3-GMP complex to acceptors such as GDP and GTP, yielding GpppG and GppppG, respectively. Our results demonstrate that lambda 3 is the avian reovirus guanylyltransferase.

[Polypoid cystitis mimicking bladder tumor]. / Cistitis polipoide simulando un tumor de vejiga.

Presentation of one case of polypoid cystitis in a 38 year-old male, with no urological history. The form of clinic presentation and the endoscopic exploration induced to suspect the existence of a bladder tumour. Diagnosis was confirmed by the result of the histopathological study of the piece.

Protein coding assignment of avian reovirus strain S1133.

Avian reovirus S1133 encodes 10 primary translation products, 8 of which are structural components of the viral particle and 2 of which are nonstructural proteins. The identity of the gene that codes for each of these polypeptides was determined by in vitro translation of denatured individual genome segments.