Plasmocitoma extramedular solitario rinosinusal: reporte de caso y revisión de literatura / Solitary extramedullary plasmacytoma of the rhinosinusal cavity: a case report and literature review

Resumen El plasmocitoma extramedular solitario (PES) es una neooplasia maligna infrecuente caracterizada por una proliferación aislada de células plasmáticas monoclonales en tejido extramedular. La localización más frecuente es en cabeza y cuello con predominio en el territorio rinosinusal, sin embargo, estas lesiones malignas representan menos del 1% de los tumores de esta región anatómica. El diagnostico requiere una alta sospecha clínica, análisis histopatológico acucioso, estudios serológicos y exámenes radiológicos sistémicos de acuerdo a los criterios diagnósticos establecidos en la literatura internacional. Se analiza el caso de un paciente masculino con un PES que se presentó como un tumor de fosa nasal derecha y obstrucción nasal de meses de evolución con hallazgos clínicos e imagenológicos inespecíficos. El diagnóstico definitivo se realizó mediante biopsia endoscópica nasal y estudio histopatológico. El tratamiento fue abordado de manera multidisciplinaria entre otorrinolaringología, hematología y radiooncología. De acuerdo a las guías internacionales, se decidió realizar radioterapia localizada con buen resultado clínico precoz. El PES requiere un abordaje multidisciplinario para lograr un diagnóstico y tratamiento oportuno, siendo imprescindible la exclusión del mieloma múltiple debido a las diferencias terapéuticas y en pronóstico clínico. El tratamiento puede realizarse con radioterapia y/o cirugía, siendo la radioterapia el pilar de tratamiento.

Abstract Solitary extramedullary plasmacytoma (SEP) is a rare malignant neoplasm characterized by isolated proliferation of monoclonal plasma cells in extramedullary tissue. The most frequent location is in the head and neck with a predominance in the rhinosinusal territory; however, these malignant lesions represent less than 1% of the tumors in this anatomical region. The diagnosis requires a high clinical suspicion, careful histopathological analysis, serological studies and systemic radiological examinations according to the diagnostic criteria established in the international literature. We analyze the case of a male patient with SEP that presented as a tumor of the right nostril and nasal obstruction of months of evolution with nonspecific clinical and imaging findings. The definitive diagnosis was made by nasal endoscopic biopsy and histopathological study. The treatment was approached by multidisciplinary teamwork. According to international guidelines, it was decided to perform localized radiotherapy with good early clinical results. SEP requires a multidisciplinary approach to achieve a timely diagnosis and treatment, being essential exclusion of multiple myeloma due to the therapeutic differences and prognosis. Treatment can be done with radiation therapy and/or surgery; radiation therapy is the mainstay of treatment.

Ictericia obstructiva secundaria a tumor de células granulares de la vía biliar extrahepática / Obstuctive jaundice secondary to extrahepatic bile ducts granular cell tumor

Bile ducts granular cell tumor is a rare entity. Of neural origin, mostly benign, may, however, present mimicking malignancy. We report a 32 years old female presenting with painless jaundice and extrahepatic bile ducts stenosis confirmed with MRC. Extrahepatic bile ducts resection is performed. Reconstruction involves four independent ducts to a Roux en Y enteric loop. She has a good postoperative outcome, with no evidence of complications nor recurrence at 17 months of follow up.

El tumor de células granulares en la vía biliar es una neoplasia rara de origen neural, en su mayoría benigna y cuya presentación puede sugerir patología maligna. Objetivo: Se presenta el caso clínico, características anatomopatológicas, manejo y evolución de una paciente joven que se presenta con ictericia obstructiva por estenosis subcarinal biliar. Paciente y Método: Paciente 32 años, sexo femenino, con ictericia, coluria y prurito. Diagnóstico de estenosis biliar y dilatación de vía biliar intrahepática se confirma con colangiorresonancia magnética. Se realiza resección de vía biliar extrahepática desde supracarinal que incluye vía biliar distal. Reconstitución bilioentérica a Y de Roux que involucra cuatro conductos intrahepáticos. Evoluciona en forma satisfactoria en el postoperatorio. El seguimiento alejado a 17 meses revela una satisfactoria condición de la paciente, sin signos de complicación o recidiva. Conclusión: El manejo por un equipo de experiencia multidisciplinario nos permitió ayudar a una paciente con rara patología, benigna en lo histológico, pero que puede representar un gran desafío técnico.

Validación de un test de tamizaje para el diagnóstico de demencia asociada a edad, en Chile / Validation of a screening test for age associated cognitive impairment, in Chile

Background: The real prevalence of dementia in a given population must be determined through prevalence studies, using validated screening tests. Aim: To validate and determine cutoff points for a cognitive impairment screening test composed by the Folstein Mini Mental State Examination (MMSE) and Pfeffer Functional Activities Questionnaire (PFAQ). Material and methods: Validation of the diagnostic test in a sample of 100 subjects over 65 years old (85 from the project ½Age associated dementias¼ and 15 with a confirmed diagnosis of dementia). All were subjected to a complete neuropsychological test by a trained neurologist, that constituted the ½gold standard¼ for the diagnosis of dementia. An independent interviewer applied the MMSE to the subjects and the PFAQ to a next of kin informer. Cutoff points were calculated using ROC curves. The points with the better equilibrium between sensitivity and specificity were selected, considering differences in results between groups with low and high educational level. Results: The cutoff point for MMSE was 21/22, with a sensitivity of 93.6 per cent (95 per cent CI 70.6-99.7per cent) and a specificity of 46.1per cent (95per cent CI 34.7-57.8 per cent). The figure for PFAQ was 5/6, with a sensitivity of 89.2per cent (95per cent CI 70.6-99.7per cent) and a specificity of 70.7per cent (95 per cent CI 58.9-80.3 per cent). The combination of both instruments gave a sensitivity of 94.4per cent (95 per cent CI 58.9-80.3 per cent) and a specificity of 83.3 per cent (95 per cent CI 72.3-90.7per cent). Conclusions: This screening test, using MMSE and PFAQ, has a good sensitivity and specificity for the diagnosis of dementia in Chile. Being simple and of low cost, it can be applied in primary health care.

Binding of host iron-binding proteins and expression of iron-regulated membrane proteins by different serotypes of Pasteurella multocida causing haemorrhagic septicaemia.

Pasteurella multocida strains of serotype B: 2,5, B: 3,4 and E: 2,5 are associated with haemorrhagic septicaemia in domestic and feral ruminants. These strains were investigated for their ability to bind transferrin, lactoferrin and haemoglobin and for their ability to use these host iron-binding proteins as a source of iron. All strains bound haemoglobin, none of the strains bound lactoferrin, whereas transferrin binding was restricted to serotype B: 2,5 strains. Growth experiments indicated that transferrin (serotype B: 2,5) and haemoglobin could restore bacterial growth under iron-depleted conditions. Two distinct serotype-independent profiles of iron-regulated membrane proteins were expressed in vitro as well as in vivo.

[Results in the treatment of 82 cases of endometrial cancer. Surgical staging vs clinical staging]. / Resultados en el tratamiento de 82 casos de cáncer de endometrio. Etapificación quirúrgica versus etapificación clínica.

Eighty two cases of endometrial carcinoma were treated from 1971 to 1994. From them twelve patients were clinically staged and 70 were staged according to 1989 FIGO classification. Thirty five patients received complementary total radiation therapy to the abdomen, pelvis and intravaginal depending on the depth of miometrial invasion, positivity of peritoneal cytology or extrauterine involvement. Thirty two patients presented with carcinoma localized to the endometrial layer received no complementary treatment. Three patients were under exploratory laparotomy with surgical non curative resection due to massive abdominal tumor invasion. The follow up revealed 59 patients free of disease (77.6%). The relapse date was 22.3%. The relapse in the clinically staged patients (n = 12) was 41.6%. The mortality rate was 15.8%.

Leucine-responsive regulatory protein, IS1 insertions, and the negative regulator FaeA control the expression of the fae (K88) operon in Escherichia coli.

Nucleotide sequence analysis of the fae operon encoding the biosynthesis of K88 fimbriae revealed the presence of two divergently transcribed regulatory genes, faeA and faeB, separated by two inverted IS1 insertions. The amino acid sequences of the regulatory proteins FaeA and FaeB show similarity to the primary structure of corresponding regulatory proteins involved in the biosynthesis of Pap and S fimbriae. Expression of faeA is positively controlled by the FaeA protein, whereas K88 fimbriae production is negatively controlled by the co-operative activity of FaeA and the leucine-responsive regulatory protein (Lrp). Exchange of FaeA for Papl, a positive regulator of Pap fimbriae expression, also represses K88 production indicating that the combination Papl/Lrp has opposite effects on fae and pap expression. Mutations in faeB had no effect on the biosynthesis of K88 fimbriae. The presence of the two IS1 insertions is hypothesized to neutralize part of the repression of K88 biosynthesis by FaeA/Lrp. Like pap, the fae operon does not respond to exogenous leucine.

Characterization of FapR, a positive regulator of expression of the 987P operon in enterotoxigenic Escherichia coli.

Expression of the 987P gene cluster is activated by the adjacent IS1 element of an STpa transposon. Nucleotide sequence analysis of the 987P-DNA region contiguous with this IS1 element revealed the presence of an open reading frame designated fapR, encoding a basic protein of 260 amino acid residues with a molecular mass of 30,349 Daltons. The gene product, FapR, possesses similarity to a number of positive regulators of gene expression: VirF, Rns, AppY and EnvY. Moreover, a 43-amino-acid residue sequence in the C-terminal part of FapR is similar to the C-terminal domain of AraC, RhaR, and RhaS. Expression of fapR is dependent on the adjacent IS1 element. The FapR protein appears to be required for activation of the silent promoter of the fimbrial subunit gene, fapC.

The 987P gene cluster in enterotoxigenic Escherichia coli contains an STpa transposon that activates 987P expression.

The genetic determinant for the production of 987P fimbriae has been cloned into pBR322. Analysis of frequently occurring deletions in the resultant recombinant plasmid, pPK180, revealed that the 987P gene cluster contains a transposon that encodes the synthesis of heat-stable enterotoxin STpa and is flanked by inverted repeats of IS1. Hybridization experiments with STpa- and 987P-specific probes demonstrated that a variety of STpa+ 987P+ wild-type Escherichia coli strains contained contiguous STpa-987P DNA, most likely on their chromosome. Transcription of the 987P gene cluster appeared to be activated by the adjacent IS1 element.

Structure and function of the androgen receptor.

The androgen receptor in several species (human, rat, calf) is a monomeric protein with a molecular mass of 100-110 kDa. The steroid binding domain is confined to a region of 30 kDa, while the DNA-binding domain has the size of approx. 10 kDa. A 40 kDa fragment containing both the DNA and steroid binding domain displayed a higher DNA binding activity than did the intact 100 kDa molecule. cDNA encoding the major part of the human androgen receptor was isolated. The cDNA contains an open reading frame of 2,277 bp but still lacks part of the 5'-coding sequence. Homology with the progesterone and glucocorticoid receptor was about 80% in the DNA binding domain and 50% in the steroid binding domain. The present data provide evidence that the androgen receptor belongs to the superfamily of ligand responsive transcriptional regulators and consists of three distinct domains each with a specialized function.

Organization and expression of genes involved in the biosynthesis of 987P fimbriae.

A chromosomal DNA segment encoding the biosynthesis of 987P fimbriae was isolated by cosmid-cloning and subsequent subcloning into pBR322. The 12 kb DNA segment expressed five polypeptides with apparent molecular weights of 81,000, 39,000, 28,500, 20,500, and 16,500, respectively. The location of the corresponding genes was determined by insertional mutagenesis using Tn5. The 20.5 K polypeptide was identified as the 987P fimbrial subunit by its reaction with specific anti-987P antibodies. The 81, 39, and 28.5 K polypeptides appeared to be accessory proteins involved in 987P production.

Organization and expression of genes involved in the biosynthesis of K99 fimbriae.

Escherichia coli K-12 minicells were used to study the expression of plasmid pFK99 encoding for the production of K99 fimbriae. Plasmid pFK99 is composed of a 6.7-kilobase pair DNA fragment derived from the wild-type K99 plasmid and the vector pBR322. The cloned K99 DNA expressed seven polypeptides with apparent masses of 18.2, 19.0, 21.0, 21.5, 26.5, 33.5, and 76.0 kilodaltons (kd). The 18.2-kd polypeptide was identified as the K99 fimbrial subunit by reaction with specific anti-K99 antibodies. The fimbrial subunit and the 19.0-, 26.5-, 33.5-, and 76.0-kd polypeptides appeared to be synthesized in a precursor form which was ca. 2 kd larger than the mature polypeptide. The location of the structural genes encoding the seven polypeptides on the physical map of pFK99 was established by analyzing a set of deletion derivatives of pFK99. The gene encoding the fimbrial subunit was located at the promoter proximal end of the K99 operon. Only mutants with a deletion in the gene encoding the 33.5- or the 19.0-kd polypeptide or both showed a weak expression of the K99 antigen and a comparably weak agglutination of horse or sheep erythrocytes. None of the deletion mutants was able to adhere to calf intestinal epithelial cells.