Impacto de los subtipos intrínsecos del cáncer de mama en la predicción de metástasis en los ganglios axilares / Impact of intrinsic subtypes of breast cancer in predicting axillary node metastases

Resumen: Introducción: Observamos que el compromiso axilar es uno de los factores de pronóstico más importantes. Aunque la asociación entre el compromiso axilar y el tamaño tumoral ha sido estudiada en varias series, la relación del subtipo según la inmunohistoquímica (IHQ) para predecir compromiso axilar, no es muy conocida. El objetivo de este estudio es correlacionar los subtipos intrínsecos según la IHQ con la afectación axilar. Como objetivos secundarios evaluamos la sobrevida global y libre de enfermedad. Material y métodos: Se incluyeron en este estudio 1.413 pacientes operadas en forma consecutiva en el Hospital Italiano de Buenos Aires con diagnóstico de cáncer de mama primario (se excluyeron los estadios IV) entre los años 2007 y 2012. Fueron analizados los datos clínicos y patológicos de las pacientes que realizaron la biopsia del ganglio centinela o la linfadenectomía axilar. Los subtipos se clasificaron en cuatro grupos según la IHQ: luminal A (RE+, RP+, HER–, Ki67 <15%); luminal B (RE+, RP+, HER+, Ki67 >14%); HER2 (RE–, RP–, HER+); y triple negativo (RE–, RP–, HER–). Resultados: Evaluamos 1.413 pacientes de las cuales se analizaron 1.248 casos, donde 386 casos (31%) mostraron metástasis en los ganglios axilares. Tomando como referencia al grupo luminal A encontramos que la presencia de compromiso axilar es significativo en aquellos subtipos luminal B y HER (p<0,0001), no así en el subtipo TN (p=0,4468). Mediante un modelo de regresión logística múltiple se evaluó la probabilidad de compromiso axilar ajustado por cada uno de los diferentes subtipos tumorales, tamaño tumoral. En aquellos tumores menores de 2 cm observamos que los tumores luminal B y los TN aumentan el riesgo de compromiso axilar con un OR=2,73 (95% IC: 1,73-4,31; p>0,000), y un OR=2,05 (95% IC: 1,13-3,70; p=0,017), respectivamente, y los tumores HER2 aumentan el riesgo con un OR=6,62 (95% IC: 3,02-14,50; p>0,000).

Ganglio centinela en cáncer de mama: experiencia de 11 años del Servicio de Ginecología del HIBA / Sentinel node in breast cancer: eleven years experience of the Breast Pathology Branch of the HIBA

Objetivo: el objetivo de este trabajo es presenter la experiencia en ganglio centinela (GC) del Sector Patología del Servicio de Ginecología del Hospital Italiano de Buenos Aires en 11 años (junio 1997 / junio 2008). Material y métodos: se evaluaron retrospectivamente las historias clínicas de las pacientes operadas por cáncer de mama estadio I y II con axila clínicamentes negativa. Hasta julio de 2009 hemos efectuado 1.032 procedimientos; 147 procedimientos que conforman el período de aprendizaje y mejoramiento del método, siempre seguida la biopsia del GC de vaciamiento axilar (06/1997 - 12/2001), y 885 en los cuales no se efectuó linfadenectomía axilar al resultar negativo el GC. A los fines de tener un seguimiento adecuado de la población analizamos 638 procedimientos realizados en 630 pacientes. Resultados: el tamaño tumoral promedio en carcinoma invasor fue 12mm (2-36mm). El ganglio centinela se halló en 623 casos (tasa de detección 97,64%). El promedio de ganglios obtenidos por procedimiento fue 1,86 (rango 1-5). De los 623 casos de GC hallado, 90 casos (14,4%) mostraron compromiso tumoral en el GC [76 casos de macrometástasis (84,44%), 13 casos micrometástasis (14,4%), y 1 caso de células tumorales aisladas (1,1%)]. En 42 de 44 casos (95,45%) de metástasis masiva en el GC, hubo ganglios no centinela comprometidos. Estos mismo se observó en 25 de 32 casos de macrometástasis sin compromiso masivo (78,12%) y en 3 de 13 casos de micrometástasis (23,07%). En la impronta intraoperatoria, 14 casos resultaron ser positivos en el estudio diferido [FN 15,55% (IC 95%. 8,7%-25,0)]. El VPN de la impronta intraoperatoria de nuestra casuística fue 97,44% (IC 95%. 95,6-98,5). El VPP 100% (94,5-100). La sensibilidad de la impronta operatoria fue 84,44% (IC 95%: 75,57-90,05). Se registró una recaída axilar al año de la cirugía con ganglio centinela negativo (0,18%) con una medida de seguimiento de 46 meses (12-84 meses).

Ganglio centinela en cáncer de mama: experiencia de 11 años del Servicio de Ginecología del HIBA / Sentinel node in breast cancer: eleven years experience of the Breast Pathology Branch of the HIBA

Objetivo: el objetivo de este trabajo es presenter la experiencia en ganglio centinela (GC) del Sector Patología del Servicio de Ginecología del Hospital Italiano de Buenos Aires en 11 años (junio 1997 / junio 2008). Material y métodos: se evaluaron retrospectivamente las historias clínicas de las pacientes operadas por cáncer de mama estadio I y II con axila clínicamentes negativa. Hasta julio de 2009 hemos efectuado 1.032 procedimientos; 147 procedimientos que conforman el período de aprendizaje y mejoramiento del método, siempre seguida la biopsia del GC de vaciamiento axilar (06/1997 - 12/2001), y 885 en los cuales no se efectuó linfadenectomía axilar al resultar negativo el GC. A los fines de tener un seguimiento adecuado de la población analizamos 638 procedimientos realizados en 630 pacientes. Resultados: el tamaño tumoral promedio en carcinoma invasor fue 12mm (2-36mm). El ganglio centinela se halló en 623 casos (tasa de detección 97,64%). El promedio de ganglios obtenidos por procedimiento fue 1,86 (rango 1-5). De los 623 casos de GC hallado, 90 casos (14,4%) mostraron compromiso tumoral en el GC [76 casos de macrometástasis (84,44%), 13 casos micrometástasis (14,4%), y 1 caso de células tumorales aisladas (1,1%)]. En 42 de 44 casos (95,45%) de metástasis masiva en el GC, hubo ganglios no centinela comprometidos. Estos mismo se observó en 25 de 32 casos de macrometástasis sin compromiso masivo (78,12%) y en 3 de 13 casos de micrometástasis (23,07%). En la impronta intraoperatoria, 14 casos resultaron ser positivos en el estudio diferido [FN 15,55% (IC 95%. 8,7%-25,0)]. El VPN de la impronta intraoperatoria de nuestra casuística fue 97,44% (IC 95%. 95,6-98,5). El VPP 100% (94,5-100). La sensibilidad de la impronta operatoria fue 84,44% (IC 95%: 75,57-90,05). Se registró una recaída axilar al año de la cirugía con ganglio centinela negativo (0,18%) con una medida de seguimiento de 46 meses (12-84 meses).(AU)

Auxin fluxes in the root apex co-regulate gravitropism and lateral root initiation.

Root architecture plays an important role in water and nutrient acquisition and in the ability of the plant to adapt to the soil. Lateral root development is the main determinant of the shape of the root system and is controlled by external factors such as nutrient concentration. Here it is shown that lateral root initiation and root gravitropism, two processes that are regulated by auxin, are co-regulated in Arabidopsis. A mathematical model was generated that can predict the effects of gravistimulations on lateral root initiation density and suggests that lateral root initiation is controlled by an inhibitory fields mechanism. Moreover, gene transactivation experiments suggest a mechanism involving a single auxin transport route for both responses. Finally, co-regulation may offer a selective advantage by optimizing soil exploration as supported by a simple quantitative analysis.

Mechanisms of primordium formation during adventitious root development from walnut cotyledon explants.

In walnut (Juglans regia L.), an otherwise difficult-to-root species, explants of cotyledons have been shown to generate complete roots in the absence of exogenous growth regulators. In the present study, this process of root formation was shown to follow a pattern of adventitious, rather than primary or lateral, ontogeny: (i) the arrangement of vascular bundles in the region of root formation was of the petiole type; (ii) a typical root primordium was formed at the side of the procambium within a meristematic ring of actively dividing cells located around each vascular bundle; (iii) the developing root apical meristem was connected in a lateral way with the vascular bundle of the petiole. This adventitious root formation occurred in three main stages of cell division, primordium formation and organization of apical meristem. These stages were characterized by expression of LATERAL ROOT PRIMORDIUM-1 and CHALCONE SYNTHASE genes, which were found to be sequentially expressed during the formation of the primordium. Activation of genes related to root cell differentiation started at the early stage of primordium formation prior to organization of the root apical meristem. The systematic development of adventitious root primordia at a precise site gave indications on the positional and biochemical cues that are necessary for adventitious root formation.

Expression of antisense chalcone synthase RNA in transgenic hybrid walnut microcuttings. Effect on flavonoid content and rooting ability.

Walnut somatic embryos (Juglans nigra x Juglans regia) were transformed with a vector containing a neomycin phosphotransferase II, a beta-glucuronidase and an antisense chalcone synthase (chs) gene. This antisense construct included a 400 bp cDNA fragment of a walnut chs gene under the control of the duplicated CaMV-35S promoter. Molecular, biochemical and biological characterizations were performed both on transformed embryos propagated by secondary somatic embryogenesis and on microshoots developed by in vitro culture of embryonic epicotyls from somatic embryos. Thirteen transformed lines with the vector containing the antisense chs gene, one line with only the gus and nptII genes and one untransformed line were maintained in tissue culture. Six of the antisense lines were shown to be flavonoid-deficient. They exhibited a strongly reduced expression of chs genes, very low chalcone synthase activity and no detectable amounts of quercitrin, myricitrin, flavane-3-ols and proanthocyanidins in stems. Rooting tests showed that decreased flavonoid content in stems of antisense chs transformed lines was associated with enhanced adventitious root formation. Free auxin and conjugated auxin contents were determined during the latter phase of the micropropagation, and no variations were detected between control and antisense chs transformed lines. The in vitro plants developed a large basal callus and apical necrosis upon auxinic induction and the transformed lines highly deficient in flavonoids were more sensitive to exogenous application of indolebutyric acid (IBA).

Insight into naphthoquinone metabolism: beta-glucosidase-catalysed hydrolysis of hydrojuglone beta-D-glucopyranoside.

In plants, the naphthoquinone juglone is known to be involved in pathogenic defence mechanisms, but it may also take part in plant developmental processes. This naphthoquinone can accumulate in a glycosylated form, namely hydrojuglone beta-d-glucopyranoside. The structural configuration of this compound was shown to be 1, 5-dihydroxy-4-naphthalenyl-beta-d-glucopyranoside by means of MS, NMR and nuclear Overhauser effect spectroscopy analyses. A hydrojuglone beta-d-glucopyranoside beta-glucosidase (EC 3.2.1.21) was purified to homogeneity from Juglans regia L. The enzyme catalysed the release of juglone from hydrojuglone beta-d-glucopyranoside with high specificity and showed Michaelis-Menten kinetics with Km=0.62 mM and Vmax=14.5 microkat/mg of protein. This enzyme also showed a higher activity towards beta-d-fucosyl than beta-d-glucosyl bonds. The purified enzyme had an apparent Mr of 64000 by SDS/PAGE and a pI 8.9 by isoelectrofocusing PAGE. The purified enzyme was inhibited by several bivalent cations, such as Cu2+, Fe2+, Hg2+, and by d-glucono-1,5-lactone, showing non-competitive inhibition of the mixed type.

Histological investigation of walnut cotyledon fragments for a better understanding of in vitro adventitious root initiation.

Rapid formation of adventitious roots by walnut cotyledon fragments in vitro was traced by light microscopy. It was shown that this plant model is characterized by two major developmental processes: a) confined elongation of the cotyledon petiole caused by a limited number of cell divisions and b) formation of a morphogenetic zone around each initially wounded vascular bundle within 36 h after detachment of the embryonic axis. During the first phase of development, granular storage protein bodies dissolved, and starch grains were deposited mainly in the distal portion of the cotyledon fragments. Rapidly, new globular protein bodies were formed, and phenolic inclusions accumulated in the vacuoles of epidermal and subepidermal cells and of individual cells close to the vascular bundles. Each adventitious root was found to be in continuity with a single vascular bundle of the cotyledon petiole. A short auxin treatment suppressed the formation of large roots and induced numerous tiny rootlets dispersed all over the surface of the cotyledons.

Use of antioxidants in extraction of tannins from walnut plants.

The radial diffusion assay was applied to estimate the amount of total tannins in extracts from walnut plant materials. We found that the protein-precipitating activity of the tannin extracts were increased by 30-75 % when antioxidants (ascorbic acid or sodium metabisulfite, 5.5 mM) were added in extraction solvents (50% aqueous methanol). The extracts obtained with Na2S2O5 were much less brown than control. Moreover, two-dimensional thin-layer chromatography revealed some additional polyphenolic compounds in the extracts made with Na2S2O5. These results suggest that the amount of tannins and/or their protein-precipitating property may be strongly affected by oxidation events during extraction procedure. The addition of antioxidants in the extraction solvents is useful to limit this problem.

Design criteria for a Raman spectrometer.

A Raman spectrochemical system has been developed based on laser radiation as the parent source. The high intensity of such radiation requires special considerations in the design of the spectrometer to reduce scattered primary radiation to better than one in part in 10(10), and these considerations are discussed. Coupling specimens of differing sizes and types to the incident radiation to optimize the intensity of Raman scattering necessitates differing approaches in optical design, and these are presented. Other design features discussed are the optics employed to collect and relay Raman radiation to the spectrometer, and the photon counting detector system. The performance of the system is typified by spectra obtained from specimens that present difficulties characteristic of Raman spectroscopy.