Tumor adenomatoide pleural / Adenomatoid pleural tumor

Introduction: Adenomatoid tumors are rare benign neoplasms, pleural is a very rare location, reporting only 4 cases worldwide and none in our country. Case report: A 30 year-old female patient, that in the context of a preventive health examination, presents a mediastinal solid mass in the right hemithorax, in the thorax radiography. The lesion of 8 cm x 7 cm x 2.4 cm was surgically removed. Histology shows a lesion compatible with pleural adenomatoid tumor and inmunohistochemistry is positive for markers such as calretinin and cytokeratin 5/6. Discussion: The pleural adenomatoid tumor is an uncommon neoplasm with benign behavior and several differential diagnoses.

Introducción: Los tumores adenomatoides son neoplasias benignas poco frecuentes, cuya ubicación pleural es de muy baja frecuencia, reportándose sólo 4 casos a nivel mundial y ninguno nacional a la fecha. Las muestras parciales en biopsia intraoperaratoria, en ausencia de antecedentes clínico-radiológicos puede representar un desafío diagnóstico. Caso clínico: Paciente de sexo femenino, 30 años que en contexto de un examen preventivo de salud se pesquisa en la radiografía de tórax una masa sólida mediastínica en hemitórax derecho. Se extirpa lesión redondeada de 8 cm. La histología muestra lesión compatible con tumor adenomatoide pleural y la inmunohistoquímica positividad para marcadores Calretinina y Citoqueratina 5/6. Discusión: El tumor adenomatoide pleural en una entidad poco frecuente, de comportamiento benigno, con diversos diagnósticos diferenciales.

[Radiologic study on postnatal ossification of the first metatarsal bone]. / Estudio radiológico sobre la osificación postnatal del primer metatarsiano.

BACKGROUND: Classical descriptions of the ossification of the first metatarsal bone show the existence of a single proximal secondary ossification nucleus, mimicking the typical ossification of a phalanx. However, there are studies that show the presence of a second distal ossification nucleus and discuss its nature: epiphysis or pseudoepiphysis. The objective of the study is to establish the prevalence of such distal nucleus, determine its role in the growth of the radius and its relation with different qualitative variables. MATERIAL AND METHODS: We conducted a retrospective study that included 971 dorsoplantar images from 225 patients. We analyzed the presence of such nucleus, the age of appearance and closure, the relation with different qualitative variables and their contribution to the longitudinal growth of the first metatarsal bone. RESULTS: The distal ossification nucleus appears in 40% of all images and in 81.1% of cases ages 4-7 years. Mean age of appearance is 3.07 years, while physeal closure occurs at a mean of 7.67 years. We found a significantly higher frequency of physeal closure in children, patients with Egyptian type foot, flat foot, and index-plus and Egyptian type foot combinations. The definitive length of the first metatarsal bone is greater in patients with a distal ossification nucleus. CONCLUSIONS: We may state the presence of the distal ossification nucleus of the first metatarsal bone that behaves as a fertile growth cartilage.

Characterization of cell death events induced by anti-neoplastic drugs cisplatin, paclitaxel and 5-fluorouracil on human hepatoma cell lines: Possible mechanisms of cell resistance.

Two different hepatoma cell lines were incubated for 48h with chemotherapeutic drugs cisplatin, paclitaxel and 5-FU to determine their ability to induce cytotoxicity and DNA fragmentation as well as to modify the expression of some cell death-related genes that could be involved in the resistance to therapy. We observed that cisplatin and paclitaxel induced cytotoxicity, but significant differences between both cell lines, were found only in the case of paclitaxel. At 48h, apoptosis was clearly present in Hep3B cells treated with cisplatin and HepG2 cells treated with paclitaxel. 5-FU induced cytotoxicity in both cell lines but only at higher concentrations than the other two drugs, triggering apoptosis and necrosis in HepG2 cells and only necrosis in Hep3B. When a time course was performed for the first 8h of treatment to elucidate the initial mechanism of cell death responsible for DNA fragmentation, we observed that 5-FU in Hep3B, and cisplatin in both cell lines, induces primary necrosis, whereas at the concentration tested here, paclitaxel clearly triggers apoptosis in both cell lines. HepG2 cells were weakly sensitive to 5-FU in the first 8h of treatment, so the primary mechanism of cell death was not clear, but results seem to indicate that it could be apoptosis. At 48h, Bax was not up-regulated with any of the treatments, whereas cisplatin was able to induce Bcl-xL down-regulation in both cell lines. Treatment with 5-FU also down-regulated Bcl-xL in HepG2 cells. We also measured variations in the expression of survivin, an inhibitor of apoptosis that has also been involved in mitototic catastrophe. Hep3B cells seem to show an increase in protein levels with all treatments. Exposure to paclitaxel resulted in the highest effect. In the case of HepG2 cells, there was a decrease in survivin expression when cells were treated with 5FU and paclitaxel, both treatments showing complete loss of the protein. Using an antibody that recognizes unprocessed caspase-3, we observed that the enzyme was assumingly activated in HepG2 cells treated with 5FU and paclitaxel, but only weakly after treatment with cisplatin. Hep3B cells did not show activation since the levels of the pro-enzyme remained the same as that in the control. In conclusion, the three drugs tested in this study could induce cell death, with paclitaxel being more effective inducing apoptosis. 5FU was only effective at high doses and its mechanism seems to be primarily related to necrosis in Hep3B and probably apoptosis in HepG2. Cisplatin mechanism of cell death is probably mediated by the decrease in anti-apoptotic protein Bcl-xL whereas paclitaxel and 5FU are decreasing the apoptosis inhibitor survivin. According to pro-enzyme levels, caspase-3 was only activated in HepG2 cells, whereas in the case of Hep3B cells the mechanisms of toxicity appear to be caspase-3-independent at the time and concentrations tested in this study. The resistance of Hep3B cells to death induced by chemotherapy could be related to an increase in the expression of IAP survivin, which can decrease cell response to the treatment or even switch the type of death from apoptosis to another kind, making therapy less efficient.

Preservation of bone collagen from the late Cretaceous period studied by immunological techniques and atomic force microscopy.

Late Cretaceous avian bone tissues from Argentina demonstrate exceptional preservation. Skeletal elements are preserved in partial articulation and suspended in three dimensions in a medium-grained sandstone matrix, indicating unusual perimortem taphonomic conditions. Preservation extends to the microstructural and molecular levels. Bone tissues respond to collagenase digestion and histochemical stains. In situ immunohistochemistry localizes binding sites for avian collagen antibodies in fossil tissues. Immunohistochemical studies do not, however, guarantee the preservation of molecular integrity. A protein may retain sufficient antigenicity for antibody binding even though degradation may render it incapable of original function. Therefore, we have applied atomic force microscopy to address the integrity and functionality of retained organic structures. Collagen pull-off measurements not only support immunochemical evidence for collagen preservation for antibody recognition but also imply preservation of the whole molecular integrity. No appreciable differences in collagen pull-off properties were measured between fossil and extant bone samples under physiological conditions.

[Signet ring cell carcinoma of sigmoid colon in an adolescent patient. Report of a case]. / Carcinoma de Células en anillo de sello del Colon en Adolecentes.

We report the case of a female patient, sixteen years old who was diagnosed of signet ring cell carcinoma of sigmoid colon. We discuss the clinical presentation outstanding the early presentation of this unusual cancer.

Quiste coledociano. Descripción de tres casos / Coledochal cyst. Description of three cases

Los quistes coledocianos so dilataciones congénitas del conducto biliar común; su incidencia es muy baja; se han reportado más de 500 casos, de los cuales,, la tercera parte se han publicado en el Japón. La triada clásicadde ictericia, dolor y tumoración se evidencia en menos de un tercio de los niños, las complicaciones más frecuentes son colangitis, obstrucción duodenal y pancreatitis. El diagnóstico de los quistes se lo hace con ecografía, colangiografía intravenosa, tomografía axial computarizada o centellografía. El tratamiento es quirúrgico Exéresis del quiste y hepatiyeyunostomía en Y de Roux. En el presente trabajo se describen tres casos de quiste coledociano en pacientes pediátricos, con edades comprendidas entre tres y diez años, atendidos en el Servicio de Pediatría del "Hospital Santa Cruz", Caja Petrolera de Salud, en el lapso de meses, que acudieron a la consulta por presentar dolor intermitente en cuadrante abdominal superior derecho, sediagnosticaron los tres quistes por ecografía. El tratamiento realizado en los tres casos fue el de la quiatectomía y hepaticoyeyunostomía en Y de Roux. La evolución postoperatoria fue favorable, no evidenciandose ninguna complicación en los controles posteriores (seguimiento de dos años)

[Dextranomer in the postoperative of anorectal surgery]. / Dextranómero en el postoperatorio de cirugía anorrectal.

Twenty patients were treated with the usual hemorrhoidectomy and fistulectomy techniques; from the nature of the region it was assumed that the postoperative wounds developed infection. Dextranomer was applied locally on 10 patients and the other 10 served as controls. It was observed that the medicament was easy to apply and the patient adapted himself to it quickly enough; none of the group under study presented collateral effects which might contraindicate its use. The healing period was considerably reduced in the problem-group and the patients went back to their usual tasks before expected. Photographic series were taken from all of them during postoperative days until healing. There were not complications in any of the groups under study.

[Effects of emetine and ipecacuana on dopamine central mechanisms. A pilot study]. / Estudios sobre el efecto de la emetina y de la ipecacuana sobre los mecanismos centrales de la dopamina. Un estudio piloto.

The lack of any rotational behaviour in unilaterally dopamine lesioned animals after ipecacuana or emetine is a strong indication that these substances lack dopamine receptor stimulating properties when administered systematically. Our results thus support those of Lal et al. (1972). Our results do not allow any conclusions concerning the working mechanism of emetine. However, the lack of central dopamine receptor stimulating properties should probably not be explained by an inability to enter through the blood brain barrier but rather a lack of effect on dopamine receptors. This reasoning would also exclude the dopamine receptors in the chemo-trigger zone as responsible for the emetic effect. In terms of the clinical usage of ipecacuana it seems highly improbable that this usage may cause adverse psychotic like side effects due to stimulation of central dopamine receptors.

Estudios sobre el efecto de la emetina y de la ipecacuana sobre los mecanismos centrales de la dopamina. Un estudio piloto / [Effects of emetine and ipecacuana on dopamine central mechanisms. A pilot study]

The lack of any rotational behaviour in unilaterally dopamine lesioned animals after ipecacuana or emetine is a strong indication that these substances lack dopamine receptor stimulating properties when administered systematically. Our results thus support those of Lal et al. (1972). Our results do not allow any conclusions concerning the working mechanism of emetine. However, the lack of central dopamine receptor stimulating properties should probably not be explained by an inability to enter through the blood brain barrier but rather a lack of effect on dopamine receptors. This reasoning would also exclude the dopamine receptors in the chemo-trigger zone as responsible for the emetic effect. In terms of the clinical usage of ipecacuana it seems highly improbable that this usage may cause adverse psychotic like side effects due to stimulation of central dopamine receptors.

Estudios sobre el efecto de la emetina y de la ipecacuana sobre los mecanismos centrales de la dopamina. Un estudio piloto. / [Effects of emetine and ipecacuana on dopamine central mechanisms. A pilot study]

The lack of any rotational behaviour in unilaterally dopamine lesioned animals after ipecacuana or emetine is a strong indication that these substances lack dopamine receptor stimulating properties when administered systematically. Our results thus support those of Lal et al. (1972). Our results do not allow any conclusions concerning the working mechanism of emetine. However, the lack of central dopamine receptor stimulating properties should probably not be explained by an inability to enter through the blood brain barrier but rather a lack of effect on dopamine receptors. This reasoning would also exclude the dopamine receptors in the chemo-trigger zone as responsible for the emetic effect. In terms of the clinical usage of ipecacuana it seems highly improbable that this usage may cause adverse psychotic like side effects due to stimulation of central dopamine receptors.