The most important prognostic factor in breast cancer is the presence or absence of metastases in axillary lymph nodes. Frozen section and touch imprint cytology are conventional intra-operative methods used in the detection of metastatic breast cancer with varying sensitivities and specificities. The limitation of these methods led to the development of alternative molecular diagnostic tests, such as GeneSearch, a commercial real-time quantitative Polymerase Chain Reaction (RT-qPCR) assay that allows for an intra-operative diagnosis of metastatic breast cancer. When the GeneSearch assay was discontinued, Metasin was developed as an in-house RT-qPCR replacement assay. Metasin targets the epithelial cell marker cytokeratin 19 (CK19) and the breast marker mammaglobin (MGB) mRNA to confirm the presence or absence of metastatic disease, whilst the reference gene porphobilinogen deaminase (PBGD) acts as a positive control for the performance of the assay. The optimised assay can produce a result within 32 minutes allowing it to be used in the intra-operative setting to detect metastatic breast cancer in sentinel lymph nodes. 154 archived lymph node homogenates that were previously analysed by both GeneSearch and histology in parallel were used to validate Metasin. Out of 154 cases, 148 showed concordance with both GeneSearch and Metasin with 111 cases being negative and 37 cases being positive. There were six discordant cases, four in which only Metasin detected metastases and two in which only GeneSearch picked up metastases. Out of the four Metasin-only positive cases, three were found to be positive on histology after deeper levels were cut in the slices sent for histological assessment. Therefore, one case could not be shown histologically to be positive for metastases. There were two cases that were missed by Metasin but picked up by GeneSearch. One case was positive on histology and the second case negative for histology. The error rate for Metasin was 3.89%. The sensitivity and specificity of the Metasin assay were found to be 95% and 98% respectively, and the positive and negative predictive values were 90% and 98% respectively. These results are comparable to those of GeneSearch. Metasin had an assay time of less than 45 minutes and was operated by biomedical scientists. The results of the validation process were deemed acceptable for the assay to be run live and used in the clinical setting. Metasin continues to provide breast cancer patients at Princess Alexandra Hospital with all the advantages that a molecular intra-operative diagnostic service provides.

Submitted by Katiane Souza (katyane.souza@gmail.com) on 2016-04-21T00:51:23Z No. of bitstreams: 1 arquivototal.pdf: 2203586 bytes, checksum: 632c234a3beaf879d47073782b8ec380 (MD5) / Made available in DSpace on 2016-04-21T00:51:24Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2203586 bytes, checksum: 632c234a3beaf879d47073782b8ec380 (MD5) Previous issue date: 2007-06-18 / Brazil is one of the three main pineapple producers in the world, being the state of Paraíba, especially, considered as the first of them. The area cultivated has slightly increased due to the small offer of good quality seedlings. This work aimed to develop a cv. EMEPA 1 micropropagation protocol especially selected to be cultivated in the state of Paraíba. The cv. EMEPA 1 axillary gems used were disinfested and inoculated in half MS solid with 5,8 pH. There was incubation in a growth room with temperature of 25 ± 5oC and photoperiod of 16 hours/light at a luminous intensity of 30 pmol.m-2.s-1, except for the etiolation phase, held at B.O.D, with no light and temperature of 28 ± 1oC. The cv. EMEPA 1 micropropagation protocol was developed according to the existing literature, comprising the following phases: treatment and isolation of explants (TI); establishing of explants (EE); etiolation (ES); regeneration (RE); multiplication (MU); extent; rooting ®; acclimatization (AC). A completely randomized design (CRD) was used in all the phases as follows: TI – CRD with 4 x 4 factorial array (4 concentrations of sodium hypochlorite x 4 exposition times to sodium hypochlorite), with 10 repetitions containing 1 explant per bottle; EE – DIC with 6 treatments comprised of 10 repetitions containing 1 explant per bottle; ES – CRD with 4 treatments, comprised of 10 repetitions containing 1 defoliated plantule per test tube; RE – DIC with 4 treatments, comprised of 10 repetitions containing 1 etiolated sprout per Petri’s plaque; MU – CRD with 8 treatments, comprised of 10 repetitions containing 1 explant per bottle; AL – CRD with 4 treatments comprised of 10 repetitions containing 1 plantule per bottle; and AC – CRD with 11 treatments, comprised of 4 repetitions containing 5 plants each. It was concluded that the concentration of 2% of sodium hypochlorite for 10 minutes causes gems disinfestation and the establishment can be carried out by means of tillage without any growth regulators. The etiolation can be achieved in MS with 1,86 mg.L-1 of ANA and regeneration in MS with 1,8mg.L-1 of ANA + 2,0 mg.L-1 of BAP. For the multiplication, the type of tillage indicated is MS supplemented with 2,0 mg.L-1 of BAP + 0,5 mg.L-1 of ANA.; in extent, the type of crop MS without any dilution causes the highest growth of plantules, whereas the addition of ANA prompts increase in number and decrease of plantules root size and the organic compound favors increase and development of pineapple plantules produced in vitro during the acclimatizing phase. / Mundialmente o Brasil se encontra entre os três maiores produtores de abacaxi e o Estado da Paraíba é reconhecido com primeiro produtor. A área cultivada tem aumentado pouco devido à pequena oferta de mudas de boa qualidade. Este trabalho teve por objetivo desenvolver um protocolo de micropropagação para a cv. EMEPA 1 selecionada especialmente para o Estado da Paraíba. Utilizaram-se gemas axilares da cv. EMEPA 1, que foram desinfestadas e inoculadas em meio MS sólido, com pH de 5,8. A incubação foi em sala de crescimento com temperatura de 25 ± 5 ºC e fotoperíodo de 16 horas luz, a uma intensidade luminosa de 30 `mol.m- 2.s-1, exceto na fase de estiolamento, que foi em B.O.D. na ausência de luz com temperatura de 28 ± 1 ºC. O protocolo de micropropagação para a cv. EMEPA 1 foi desenvolvido de acordo com a literatura existente e contempla as fases: tratamento e isolamento dos explantes (TI); estabelecimento de explantes (EE); estiolamento (ES); regeneração (RE); multiplicação (MU); alongamento (AL); enraizamento (EN) e aclimatação (AC). Em todas as fases se empregou o delineamento inteiramente casualizado (DIC), conforme a seguir: TI – DIC com arranjo fatorial 4 x 4 (4 concentrações de hipoclorito de sódio x 4 tempos de exposição ao hipoclorito de sódio), com 10 repetições contendo 1 explante por frasco; EE – DIC com 6 tratamentos, composto de 10 repetições contendo 1 explante por frasco; ES – DIC com 4 tratamentos, composto de 10 repetições contendo 1 plântula desfolhada por tubo de ensaio; RE – DIC com 4 tratamentos, composto de 10 repetições contendo 1 broto estiolado por placa de Petri; MU – DIC com 8 tratamentos, composto de 10 repetições contendo 1 explante por frasco; AL – DIC com 4 tratamentos, composto de 10 repetições contendo 1 plântula por frasco; EN – DIC com 4 tratamentos, composto de 10 repetições contendo 1 plântula por frasco e AC – DIC com 11 tratamentos, composto de 4 repetições contendo 5 plantas cada. Concluiu-se que a concentração de 2% de hipoclorito de sódio por 10 minutos, promove a desinfestação das gemas e o estabelecimento pode ser em meio de cultivo sem reguladores de crescimento, o estiolamento pode ser realizado em meio MS com 1,86 mg.L-1 de ANA e a regeneração em meio MS com 1,8 mg.L-1 de ANA + 2,0 mg.L-1 de BAP. Para a multiplicação o meio de cultivo indicado é o MS suplementado com 2,0 mg.L-1 de BAP + 0,5 mg.L-1 de ANA; no alongamento o meio de cultura MS sem diluição proporciona o maior crescimento das plântulas, enquanto a adição do ANA promove o aumento no número e a diminuição do tamanho das raízes das plântulas e o composto orgânico favorece o crescimento e o desenvolvimento de plântulas de abacaxizeiro, produzidas in vitro, na fase de aclimatação.

BACKGROUND: In order to maintain non-weight bearing restrictions of the lower extremity, an assistive device must be utilized. Currently most devices require the restricted limb to be held in a static position while the contralateral extremity provides forward propulsion. Atrophy and disuse conditions ensue rapidly, slowing healing and prolonging recovery. A hands-free single crutch (HFSC) utilizes both lower extremities, potentially reducing atrophy. The purpose of this study was to examine the Electromyography (EMG) differences between a HFSC and standard axillary crutches (SAC). METHODS: A prospective, crossover study was performed using 21 healthy volunteers from an active duty foot and ankle clinic. Demographic data was obtained and then subjects were fitted with a HFSC and SAC. Wireless surface EMG sensors were applied to the belly of the rectus femoris (RF), vastus lateralis (VL), lateral gastrocnemius (LG), and the gluteus maximus (GM) by a board-certified orthopedic surgeon. Subjects then ambulated at a self-selected velocity for 30 meters, while 15 seconds of the gait cycle was recorded for each device. Mean muscle activity and the maximum voluntary isometric contraction (MVIC) were recorded. RESULTS: The RF, GM, and LG showed statistically significant increased levels of muscle activity while using the HFSC compared to SAC (respectively P = 0.05, P = 0.03, P = 0.03). The VL did not show statistically higher muscle activity while using the HFSC (P = 0.051). The RF, GM, and VL showed statistically significant higher MVIC percentages while using the HFSC compared to using SAC (respectively P = 0.005, P = 0.005, P = 0.013). The LG did not show statistically higher MVIC percentage while using the HFSC (P = 0.076). CONCLUSION: The HFSC subjects demonstrated increased muscle recruitment and intensity while maintaining cyclic contractions consistent with bipedal gait pattern. SAC demonstrated less recruitment and intensity with an isometric pattern regardless of the phase of gait. / 2022-06-04T00:00:00Z

INTRODUÇÃO: O status linfonodal da axila ainda permanece como importante fator prognóstico em pacientes com câncer de mama invasivo. Muitos estudos já relataram a importância da ultrassonografia axilar e da punção aspirativa por agulha fina (PAAF) na avaliação pré-operatória das pacientes com câncer de mama. Nossos objetivos foram avaliar as características ultrassonográficas dos linfonodos axilares relacionadas à metástase linfonodal e o papel da PAAF na avaliação pré-operatória de pacientes com câncer de mama. Nosso objetivo secundário foi avaliar se, dependendo das características dos tumores, linfonodos sem alterações na ultrassonografia poderiam ter comprometimento metastático. MÉTODOS: Este estudo foi realizado no Instituto de Radiologia e no Instituto do Câncer do HCFMUSP. Foram incluídas 182 pacientes com câncer de mama invasivo recém-diagnosticado, sendo que, destas, apenas 145 realizaram cirurgia - 74 prosseguiram direto para cirurgia e 71 realizaram tratamento neoadjuvante e após cirurgia. Foi realizada avaliação ultrassonográfica da axila ipsilateral ao tumor e punção aspirativa por agulha fina de um linfonodo selecionado pelo radiologista. Os dados ultrassonográficos dos linfonodos e os achados citológicos da PAAF foram correlacionados com os resultados anatomopatológicos da biópsia do linfonodo sentinela ou do esvaziamento axilar. RESULTADOS: Nas 74 pacientes (75 axilas) que não realizaram tratamento neoadjuvante, as características ultrassonográficas do linfonodo associadas à metástase na análise univariada foram espessamento cortical difuso e a obliteração parcial ou completa do hilo gorduroso. A sensibilidade, especificidade, acurácia, valor preditivo positivo (VPP) e valor preditivo negativo (VPN) da ultrassonografia foram, respectivamente, 72,7%, 57,1%, 64,0%, 57,1% e 72,7% (p=0,009), e da PAAF: 36,4%, 97,6%, 70,7%, 92,3% e 66,1% (p < 0,001). Incluindo apenas linfonodos alterados na ultrassonografia, obtivemos, respectivamente, sensibilidade, especificidade, acurácia, VPP e VPN de 50%, 94%, 69%, 92% 59% (p=0,001). Nenhuma PAAF de linfonodo classificado como normal na ultrassonografia teve resultado positivo. Obtivemos, nas análises das curvas ROC, um valor de corte da espessura da cortical de 2,65 mm (p < 0,001) e do tamanho do tumor pré-cirúrgico de 2,45 cm (p=0,042). Na análise multivariada, as seguintes características foram associadas à metástase linfonodal: espessura da cortical (p = 0,005), tamanho do tumor pré-cirúrgico (p = 0,030), status pré-menopausa (p = 0,017), tipo histológico não especial (p = 0,034) e localização do tumor no quadrante superolateral (p = 0,011). Construiu-se um modelo de predição de risco de metástase axilar usando estas características. Nas 71 pacientes que realizaram tratamento adjuvante, a única característica do linfonodo associada à metástase linfonodal foi a forma redonda ou irregular. Os demais resultados deste grupo não podem ser generalizados, pois não é possível separar o efeito do tratamento nesta população. CONCLUSÕES: Linfonodos axilares com espessamento cortical difuso e com obliteração parcial ou completa do hilo gorduroso estão associados à malignidade. A PAAF apresentou-se mais útil nos linfonodos alterados, com sensibilidade de 50%. Pacientes com PAAF positivas devem ser encaminhadas para esvaziamento axilar ou quimioterapia neoadjuvante. Não há benefício da realização da PAAF em linfonodos sem alterações na ultrassonografia / BACKGROUND: The lymph node status of the axilla remains an important prognostic factor in patients with invasive breast cancer. Many studies have already reported the importance of axillary ultrasonography and fine needle aspiration (FNA) in the preoperative evaluation of patients with breast cancer. Our objectives were to evaluate the ultrasound characteristics of axillary lymph nodes related to lymph node metastasis and the role of FNA in the preoperative evaluation of patients with breast cancer. Our secondary objective was to assess whether, depending on the tumor characteristics, lymph nodes that showed no change on ultrasonography could have metastatic involvement. METHODS: This study was conducted at the Institute of Radiology and the Institute of Cancer of HCFMUSP. A total of 182 patients with newly diagnosed invasive breast cancer were included, of whom only 145 had undergone surgery - 74 went straight to surgery and 71 underwent neoadjuvant treatment and after surgery. Ultrasound evaluation of the axilla ipsilateral to the tumor and fine needle aspiration of a lymph node selected by the radiologist were performed. The ultrasound data of the lymph nodes and the cytological findings of FNA were correlated with pathology results from sentinel lymph node biopsy or surgical dissection. RESULTS: In the 74 patients (75 axillae) who did not undergo neoadjuvant treatment, the ultrasound characteristics of the lymph nodes associated with metastasis in the univariate analysis were diffuse cortical thickening and partial or complete fatty hilum obliteration. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of ultrasound were respectively 72.7%, 57.1%, 64.0%, 57.1% and 72.7% (p = 0.009) and of the FNA 36.4%, 97.6%, 70.7%, 92.3% and 66.1% (p <0.001). Including only atypical lymph nodes on ultrasonography, we obtained respectively sensitivity, specificity, accuracy, PPV and NPV of 50%, 94%, 69% 92% and 59% (p = 0.001). No FNA of lymph node classified as normal on ultrasonography had a positive result. With ROC curves analysis we obtained a cut-off value of cortical thickness of 2.65 mm (p <0.001) and pre-surgical tumor size of 2.45 cm (p = 0.042). In the multivariate analysis, the following characteristics were associated with lymph node metastasis: cortical thickness (p = 0.005), preoperative tumor size (p = 0.030), premenopausal status (p = 0.017), non-special histological type and tumor location in the upper outer quadrant (p = 0.011). A predictive model of axillary metastasis risk was constructed using these characteristics. In the 71 patients who underwent adjuvant treatment the only feature of the lymph node associated with lymph node metastasis was the round or irregular shape. The other results of this group cannot be generalized since it is not possible to separate the treatment effect in this population. CONCLUSIONS: Axillary lymph nodes with diffuse cortical thickening and with partial or complete fatty hilum obliteration are associated with malignancy. FNA was more useful in atypical lymph nodes, with a sensitivity of 50%. Patients with positive FNA should be referred for axillary surgical dissection or neoadjuvant chemotherapy. There is no benefit of performing FNA in lymph nodes without changes in ultrasound

INTRODUÇÃO: O status linfonodal da axila ainda permanece como importante fator prognóstico em pacientes com câncer de mama invasivo. Muitos estudos já relataram a importância da ultrassonografia axilar e da punção aspirativa por agulha fina (PAAF) na avaliação pré-operatória das pacientes com câncer de mama. Nossos objetivos foram avaliar as características ultrassonográficas dos linfonodos axilares relacionadas à metástase linfonodal e o papel da PAAF na avaliação pré-operatória de pacientes com câncer de mama. Nosso objetivo secundário foi avaliar se, dependendo das características dos tumores, linfonodos sem alterações na ultrassonografia poderiam ter comprometimento metastático. MÉTODOS: Este estudo foi realizado no Instituto de Radiologia e no Instituto do Câncer do HCFMUSP. Foram incluídas 182 pacientes com câncer de mama invasivo recém-diagnosticado, sendo que, destas, apenas 145 realizaram cirurgia - 74 prosseguiram direto para cirurgia e 71 realizaram tratamento neoadjuvante e após cirurgia. Foi realizada avaliação ultrassonográfica da axila ipsilateral ao tumor e punção aspirativa por agulha fina de um linfonodo selecionado pelo radiologista. Os dados ultrassonográficos dos linfonodos e os achados citológicos da PAAF foram correlacionados com os resultados anatomopatológicos da biópsia do linfonodo sentinela ou do esvaziamento axilar. RESULTADOS: Nas 74 pacientes (75 axilas) que não realizaram tratamento neoadjuvante, as características ultrassonográficas do linfonodo associadas à metástase na análise univariada foram espessamento cortical difuso e a obliteração parcial ou completa do hilo gorduroso. A sensibilidade, especificidade, acurácia, valor preditivo positivo (VPP) e valor preditivo negativo (VPN) da ultrassonografia foram, respectivamente, 72,7%, 57,1%, 64,0%, 57,1% e 72,7% (p=0,009), e da PAAF: 36,4%, 97,6%, 70,7%, 92,3% e 66,1% (p < 0,001). Incluindo apenas linfonodos alterados na ultrassonografia, obtivemos, respectivamente, sensibilidade, especificidade, acurácia, VPP e VPN de 50%, 94%, 69%, 92% 59% (p=0,001). Nenhuma PAAF de linfonodo classificado como normal na ultrassonografia teve resultado positivo. Obtivemos, nas análises das curvas ROC, um valor de corte da espessura da cortical de 2,65 mm (p < 0,001) e do tamanho do tumor pré-cirúrgico de 2,45 cm (p=0,042). Na análise multivariada, as seguintes características foram associadas à metástase linfonodal: espessura da cortical (p = 0,005), tamanho do tumor pré-cirúrgico (p = 0,030), status pré-menopausa (p = 0,017), tipo histológico não especial (p = 0,034) e localização do tumor no quadrante superolateral (p = 0,011). Construiu-se um modelo de predição de risco de metástase axilar usando estas características. Nas 71 pacientes que realizaram tratamento adjuvante, a única característica do linfonodo associada à metástase linfonodal foi a forma redonda ou irregular. Os demais resultados deste grupo não podem ser generalizados, pois não é possível separar o efeito do tratamento nesta população. CONCLUSÕES: Linfonodos axilares com espessamento cortical difuso e com obliteração parcial ou completa do hilo gorduroso estão associados à malignidade. A PAAF apresentou-se mais útil nos linfonodos alterados, com sensibilidade de 50%. Pacientes com PAAF positivas devem ser encaminhadas para esvaziamento axilar ou quimioterapia neoadjuvante. Não há benefício da realização da PAAF em linfonodos sem alterações na ultrassonografia / BACKGROUND: The lymph node status of the axilla remains an important prognostic factor in patients with invasive breast cancer. Many studies have already reported the importance of axillary ultrasonography and fine needle aspiration (FNA) in the preoperative evaluation of patients with breast cancer. Our objectives were to evaluate the ultrasound characteristics of axillary lymph nodes related to lymph node metastasis and the role of FNA in the preoperative evaluation of patients with breast cancer. Our secondary objective was to assess whether, depending on the tumor characteristics, lymph nodes that showed no change on ultrasonography could have metastatic involvement. METHODS: This study was conducted at the Institute of Radiology and the Institute of Cancer of HCFMUSP. A total of 182 patients with newly diagnosed invasive breast cancer were included, of whom only 145 had undergone surgery - 74 went straight to surgery and 71 underwent neoadjuvant treatment and after surgery. Ultrasound evaluation of the axilla ipsilateral to the tumor and fine needle aspiration of a lymph node selected by the radiologist were performed. The ultrasound data of the lymph nodes and the cytological findings of FNA were correlated with pathology results from sentinel lymph node biopsy or surgical dissection. RESULTS: In the 74 patients (75 axillae) who did not undergo neoadjuvant treatment, the ultrasound characteristics of the lymph nodes associated with metastasis in the univariate analysis were diffuse cortical thickening and partial or complete fatty hilum obliteration. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of ultrasound were respectively 72.7%, 57.1%, 64.0%, 57.1% and 72.7% (p = 0.009) and of the FNA 36.4%, 97.6%, 70.7%, 92.3% and 66.1% (p <0.001). Including only atypical lymph nodes on ultrasonography, we obtained respectively sensitivity, specificity, accuracy, PPV and NPV of 50%, 94%, 69% 92% and 59% (p = 0.001). No FNA of lymph node classified as normal on ultrasonography had a positive result. With ROC curves analysis we obtained a cut-off value of cortical thickness of 2.65 mm (p <0.001) and pre-surgical tumor size of 2.45 cm (p = 0.042). In the multivariate analysis, the following characteristics were associated with lymph node metastasis: cortical thickness (p = 0.005), preoperative tumor size (p = 0.030), premenopausal status (p = 0.017), non-special histological type and tumor location in the upper outer quadrant (p = 0.011). A predictive model of axillary metastasis risk was constructed using these characteristics. In the 71 patients who underwent adjuvant treatment the only feature of the lymph node associated with lymph node metastasis was the round or irregular shape. The other results of this group cannot be generalized since it is not possible to separate the treatment effect in this population. CONCLUSIONS: Axillary lymph nodes with diffuse cortical thickening and with partial or complete fatty hilum obliteration are associated with malignancy. FNA was more useful in atypical lymph nodes, with a sensitivity of 50%. Patients with positive FNA should be referred for axillary surgical dissection or neoadjuvant chemotherapy. There is no benefit of performing FNA in lymph nodes without changes in ultrasound

Poaceae (or Gramineae) belong to the grass family and is one of the largest families among flowering plants on land. They include some of the most important cereal crops such as rice (Oryza sativa), barley (Hordeum vulgare), wheat (Triticum aestivum), maize (Zea mays), and sorghum (Sorghum bicolor). The characteristic bushy appearance of grass plants, including cereal crops, is formed by the activities of axillary meristems (AMs) generated in the leaf axil. These give rise to tillers from the basal nodes which recapitulate secondary growth axis and AMs are formed during vegetative development. On transition to flowering the apical meristem transforming to an inflorescence meristem (IM) which produces branches from axillary meristem. These IM gives rise to branches that ultimately bear florets. Vegetative branching/tillering determines plant biomass and influences the number of inflorescences per plant. While inflorescence branching determines the number of florets and hence seeds. Thus the overall activity of axillary meristems plays a key role in determining plant architecture during both vegetative and reproductive stages. In Arabidopsis, research on the plant specific transcription factor LEAFY (LFY) has pioneered our understanding of its regulatory functions during transition from vegetative to reproductive development and its role in specifying a floral meristem (FM) identity to the newly arising lateral meristems. In the FM LFY activates other FM genes and genes for floral organ patterning transcription factors. LFY is strongly expressed throughout the young floral meristems from the earliest stages of specification but is completely absent from the IM (Weigel et al., 1992). LFY expression can also be detected at low levels in the newly emerging leaf primordia during the vegetative phase, and these levels gradually increase until the floral transition (Blazquez et al., 1997; Hempel et al., 1997). In rice, the LFY ortholog-RFL/APO2 is expressed predominantly in very young branching panicles/ inflorescence meristems (Kyozuka et al., 1998; Prasad et al., 2003) while in the vegetative phase RFL is expressed at axils of leaves (Rao et al., 2008). In rice FMs expression is restricted to primordia of lodicules, stamens, carpels and ovules (Ikeda-Kawakatsu et al., 2012). Knockdown of RFL activity or loss of function mutants show delayed flowering and poor panicle branching with reduced number of florets and lower fertility (Rao et al., 2008, Ikeda-Kawakatsu et al., 2012). In some genotypes reduced vegetative axillary branching is also compromised (Rao et al., 2008). On the other hand RFL overexpression leads to the early flowering, attributing a role as an activator for the transition of vegetative meristems to inflorescence meristems (Rao et al., 2008). Thus, RFL shows a distinct developmental expression profile, has unique mutant phenotypes as compared to Arabidopsis LFY thus indicating a divergence in functions. We have used various functional genomics approaches to investigate regulatory networks controlledby RFL in the vegetative axillary meristems and in branching panicles with florets. These regulatory effects influence tillering and panicle branching, thus contributing to rice plant architecture. RFL functions in axillary meristem Vegetative AMs are secondary shoot meristems whose outgrowth determines plant architecture. In rice, AMs form tillers from basal nodes and mutants with altered tillering reveal that an interplay between transcription factors and the phytohormones - auxin, strigolactone underpins this process. We probed the relationship between RFL and other factors that control AM development. Our findings indicate that the derangements in AM development that occur on RFL knockdown arise from its early effects during specification of these meristems and also later effects during their outgrowth of AM as a tiller. Overall, the derailments of both steps of AM development lead to reduced tillering in plants with reduced RFL activity. Our studies on the gene expression status for key transcription factor genes, genes for strigolactone pathway and for auxin transporters gave an insight on the interplay between RFL, LAX1 and strigolactone signalling. Expression levels of LAX1 and CUC genes, that encode transcription factors with AM specification functions, were modulated upon RFL knockdown and on induction of RFL:ΔGR fusion protein. Thus our findings imply a likely, direct activating role for RFL in AM development that acts in part, through attaining appropriate LAX1 expression levels. Our data place meristem specification transcription factors LAX1 and CUC downstream to RFL. Arabidopsis LFY has a predominant role in conferring floral meristem (FM) identity (Weigel et al., 1992; Wagner, 2009; Irish, 2010; Moyroud et al., 2010). Its functions in axillary meristems were not known until recently. The latter functions were uncovered with the new LFYHARA allele with only partial defects in floral meristem identity (Chahtane et al., 2013). This mutant allele showed LFY can promote growth of vegetative AMs through its direct target REGULATOR OF AXILLARY MERISTEMS1 (RAX1), a R2R3 myb domain factor (Chahtane et al., 2013). These functions for Arabidopsis LFY and RAX1 in AMs development are parallel to and redundant with the pathway regulated by LATERAL SUPPRESSOR (LAS) and REGULATOR OF AXILLARY MERISTEM FORMATION1 (ROX1) (Yang et al., 2012; Greb et al., 2003). Interestingly, ROX1 is orthologous to rice LAX1 and our data show LAX1 expression levels in rice panicles and in culms with vegetative AMs is dependent on the expression status of RFL. Thus, we speculate that as compared to Arabidopsis AM development, in rice the LFY-dependent and LFY-independent regulatory pathways for AMs development are closely linked. In Arabidopsis, CUC2 and CUC3 genes in addition to their role in shoot meristem formation and organ separation play a role in AM development possibly by defining a boundary for the emerging AM. These functions for the Arabidopsis CUC genes are routed through their effects on LAS and also by mechanisms independent of LAS (Hibara et al., 2006; Raman et al., 2008). These data show modulation in RFL activity using the inducible RFL:∆GR protein leads to corresponding expression changes in CUC1/CUC2 and CUC3 genes expression in culm tissues. Thus, during rice AM development the meristem functions of RFL and CUC genes are related. Consequent to specification of AM the buds are kept dormant. Bud outgrowth is influenced by auxin and strigolactone signalling pathways. We investigated the transcript levels, in rice culms of genes involved in strigolactone biosynthesis and perception and found the strigolactone biosynthesis gene D10 and hormone perception gene are significantly upregulated in RFL knockdown plants. Further, bioassays were done for strigolactone levels, where we used arbuscular mycorrhiza colonization assay as an indicator for strigolactone levels in wild type plants and in RFL knockdown plants. These data validate higher strigolactone signalling in RFL knockdown plants. To probe the relationship between RFL and the strigolactone pathway we created plants knocked down for both RFL and D3. For comparison of the tillering phenotype of these double knockdown plants we created plants with D3 knockdown alone. We observed reduced tillering in plants with knockdown of both RFL and D3 as compared to the tiller number in plants with knockdown of D3 alone. These data suggest that RFL acts upstream to D3 of control bud outgrowth. As effects of strigolactones are influenced by auxin transport we studied expression of OsPIN1 and OsPIN3 in RFL knockdown plants. Their reduced expression was correlated with auxin deficiency phenotypes of the roots in RFL knockdown plants. These data in conjunction with observations on OsPIN3 the gene expression modulation by the induction of RFL:∆GR allow us to speculate on a relationship between RFL, auxin transport and strigolactones with regard to bud outgrowth. We propose that the low tillering phenotype of RFL knockdown plants arises from weakened PATS, consequent to low levels of PIN1 and PIN3, coupled with moderate increase in strigolactones. Taken together, our findings suggest functions for RFL during AM specification and tiller bud outgrowth. RFL functions in panicle branching Prior studies on phenotypes of RFL knockdown or loss of function mutants suggested roles for RFL in transition to flowering, inflorescence meristem development, emergence of lateral organs and floral organ development (Rao et al., 2008; Ikeda-Kawakatsu et al., 2012). It has been speculated that RFL acts to suppress the transition from inflorescence meristem to floral meristem through its interaction with APO1 (Ikeda-Kawakatsu et al., 2012). The downstream genes regulated by RFL in these processes have not yet been elucidated. To identify direct targets of RFL in developing panicles we adopted ChIP-seq coupled with studies on gene expression modulation on induction of RFL. For the former we raised polyclonal anti-sera and chromatin from branching panicles with few florets. For gene expression modulation studies, we created transgenics with a T-DNA construct where an artificial miRNA against 3’UTR specifically knocked endogenous RFL and the same T-DNA had a second expression cassette for generation of a chemically inducible RFL-ΔGR protein that is not targeted by amiR RFL. Our preliminary ChIP-seq data in the wild type panicle tissues hints that RFL binds to hundreds of loci across the genome thus providing first glimpse of direct targets of RFL in these tissues. These data, while preliminary, were manually curated to identify likely targets that function in flowering, we summarize here some key findings. Our study indicates a role of RFL in flowering transition by activating genes like OsSPL14 and OsPRMT6a. Recent studies indicate that OsSPL14 directly binds to the promoter of OsMADS56 or FTL1, the rice homologs of SOC1 and FT to promote flowering (Lu et al., 2013). As RFL knockdown plants show highly reduced expression of OsMADS50/SOC1 and for RFT1 (Rao et al., 2008), and we show here RFL can bind and induce OsSPL14 expression we suggest the RFL¬OsSPL14 module can contribute to the transition of the SAM to flowering. Further, OsSPL14 in the young panicles directly activates DENSE AND ERECT PANICLE1 (DEP1) to control panicle length (Lu et al., 2013). Thus RFL-OsSPL14-DEP1 module could explain the role of RFL in controlling panicle architecture (Rao et al., 2008; Ikeda-Kawakatsu et al., 2012). Thus RFL plays a role in floral transition and this function is conserved across several LFY homologs. Our data ChIP-seq in the wild type tissue and gene expression modulation studies in transgenics also give molecular evidences for the role of RFL in suppression of floral fate. The direct binding of RFL to OsMADS17, OsYABBY3, OsMADS58 and HD-ZIP-IV loci and the changes in their transcript levels on induction of RFL support this hypothesis. Once the transition from SAM to FM takes place, we speculate RFL represses the conversion of inflorescence branch meristems to floral fate by negatively regulating OsYABBY3, HD-ZIP class IV and OsMADS17 that can promote differentiation. These hypotheses indicate a diverged function for RFL in floral fate repression. Arabidopsis LFY is known to activate the expression of AGAMOUS (AG), whose orthologs in rice are OsMADS3 and OsMADS58. Our studies confirm conservation with regard to RFL binding to cis elements at OsMADS58 locus that is homologous to Arabidopsis AG. But importantly we show altered consequences of this binding on gene expression. We find RFL can suppress the expression of OsMADS58 which we speculate can promote a meristematic fate. Further, we also present the abnormal upregulation of floral organ fate genes on RFL downregulation. These data too indicate functions of RFL, are in part, distinct from the role of Arabidopsis LFY where it works in promoting floral meristem specification and development. These inferences are supported by our data that rice gene homologs for AP1, AP3 and SEP3 are not directly regulated by RFL, unlike their direct regulation by Arabidopsis LFY during flower development. We also report the expression levels of LAX1, FZP, OsIDS1 and OsMADS34 genes involved in meristem phase change and IM branching are RFL dependent. This is consistent with its role in the suppression of determinacy, thereby extending the IM activity for branch formation. But as yet we do not know if these effects are direct. Together, our data report direct targets of RFL that contribute to its functions in meristem regulation, flowering transition, and suppression of floral organ development. Overall, our preliminary data on RFL chromatin occupancy combined with our detailed studies on the modulation of gene expression provides evidence for targets and pathways unique to the rice RFL during inflorescence development. Comparative analysis of genes downstream to RFL in vegetative tillers Vs panicles Tillers and panicle branches arise from the axillary meristems at vegetative and reproductive stages, respectively, of a rice plant and overall contribute to the plant architecture. Some regulatory factors control branching in both these tissues - for example, MOC1 and LAX1. Mutants at these loci affect tillers and panicle branch development thus indicating common mechanisms control lateral branch primordia development (Li et al., 2003; Komatsu et al., 2003; Oikawa and Kyozuka, 2009). Knockdown of RFL activity or loss-of-function mutants cause significantly reduced panicle branching and in few instances, reduction in vegetative axillary branching (Rao et al., 2008; Ikeda- Kawakatsu et al., 2012). We took up the global expression profiling of RFL knockdown plants compared to wild type plants in the axillary meristem and branching panicle tissue. These data provide a useful list of potential targets of RFL in axillary meristem and branching panicle tissue. The comparative analysis of the genes affected in the two tissues indicates only a subset of genes is affected by RFL in both the vegetative axillary meristems and branching panicle. These genes include transcription factors (OsSPL14, Zn finger domain protein, and bHLH domain protein), hormone signalling molecules (GA2 ox9) and cell signalling (LRR protein) as a set of genes activated by RFL in both tissues. On the other hand, these comparative expression profiling studies also show distinct set of genes deregulated by RFL knockdown in these two tissues therefore implicating RFL functions have a tissue-specific context. The genes deregulated only in axillary meristem tissue only include D3- involved in the perception of strigolactone, OsMADS34 speculated to have a role in floral transition and RCN1 involved in transition to flowering. On the other hand, the genes – CUC1, OsMADS3, OsMADS58 involved in organ development and floral meristem determination were found to be deregulated only in panicle tissues of RFL knockdown plants. These data point towards presence of distinct mechanisms for the development of AMs as tillers versus the development of panicle axillary as rachis branches. Overall, these data implicate genes involved in transition to flowering, axillary meristem development and floral meristem development are controlled by RFL in different meristems to thereby control plant architecture and transition to flowering.

LFY of Arabidopsis is a member of a unique plant specific transcription factor family. It is involved in giving meristem a determinate floral fate by the activation of floral organ identity genes and preventing inflorescence meristem identity. RFL is a homolog of FLO/LFY in rice. Studies from our lab on rice RFL, based on the effects of knockdown or overexpression, showed its major functions are in timing the conversion of SAM to IM and to prevent the premature conversion of branch meristem to spikelets. Additionally roles in vegetative axillary meristem specification have been also been identified in laboratory. Here, we attempt to delineate molecular pathways directly regulated by RFL as a transcription factor controlling inflorescence and floral development in rice. Part I: Identification of global target genes bound by RFL in developing rice inflorescences We carried out ChIP sequencing of the DNA bound by RFL in panicles (01.-0.3cm stage) using anti-RFL antibody. DNA sequences in one library pool were analyses by the MACS algorithm (FDR<0.01), to find 8000 binding sites while the SPP algorithm identified 5000 enriched peaks. These mapped to 2500 or 2800 gene-associated loci respectively, 617 of which were common loci to both pipelines. Several RFL bound gene loci were homologs of Arabidopsis thaliana LFY gene targets. Such gene targets underscore conserved downstream targets for LFY-proteins in evolutionarily very distinct species. AtLFY is known to bind variants of CCANT/G cis element classified as primary, inflorescence or seedling type. We scanned for these three types of cis elements at 123 RFL bound genes with likely functions in flowering. For a few of these 123 rice loci we find one of these cis motifs (p-value<0.001) in RFL bound ChIP-seq data. To validate these targets of RFL, we adopted in vitro DNA-protein binding assays with bacterially purified RFL protein. We confirm RFL target interactions with some genes implicated in flowering time, others in photoperiod triggered flowering, circadian rhythm, gibberellin hormone pathway, inflorescence development and branching. The in vitro experiments hint different RFL-DNA binding properties as compared to Arabidopsis LFY. We report binding to sequences at rice gene loci that are unique targets. Part II: Pathways regulated by RFL for reproductive transition and panicle development To co-relate DNA binding of RFL to target loci with changes in their gene expression, expression studies were taken up for selected set of genes implicated in rice flowering transition and panicle architecture. To study in planta and tissue specific gene regulation by RFL we raised RFL dsRNAi transgenics. Comparative transcript analysis in these RFL partial knockdown lines and matched wild type tissues reveal that RFL is an activator for some genes and repressor for other gene targets. We also examined if the gene expression effects of RFL knockdown can be reversed by induced complementation with an RFL-GR protein. We raised transgenics plants with a T-DNA ubi:RFL-GR, 35S CaMV:amiR RFL for these experiments. In planta target gene transcript levels were assessed in various conditions conditions. These studies validate rice RFL as an activator of some panicle architecture genes. Part III: Analysis of endogenous RFL protein in WT rice tissues Studies in Arabidopsis and in petunia with LFY and AFL, respectively, implicate these some abnormal mobility as compared to their predicted molecular weight when overexpressed. We studied endogenous RFL protein abundance in planta, adopting western analysis with anti-RFL antibody. We consistently identify two prominent cross reacting bands in different tissues which can be also be pulled-down from whole nuclear extracts of panicle and axillary meristem tissues. We speculate on likely modifications and possible functions for the same.

A 53 year-old male presented with a one-day history of a swollen arm and dull, aching pain in the right upper extremity. The patient reported commencing exercising daily over the prior week with a modified, oscillating dumbbell; commonly referred to as a Shake Weight. Imaging revealed an occlusive thrombus in the right axillary, proximal brachial and basilic veins. The patient was treated with a 24-hour tPA infusion followed by mechanical thrombectomy, balloon angioplasty, and stent placement for a residual thrombus and stenosis. The patient was discharged the following day on warfarin and aspirin. This is the first report of effort-induced thrombosis of the upper extremity following the use of a modified, oscillating dumbbell. Due to the growing popularity of modified dumbbells and the possible risk for axillary vein thrombosis, consideration should be made to caution consumers of this potential complication.

Characterization of the ontogenic program is essential to infer about palnts adaptation strategies. Frequently, morphogenesis of tropical forage grasses is reported to be analogous to that of temperate forage grasses. However, tropical grasses show stem development still during the vegetative phase of growth and under high light availability conditions. Stem elongation potentially impacts plants growth, with implications for grazing management. In tropical conditions, elephantgrass cv. Napier is considered one of the most productive grass species under grazing. The objective of this study was to characterize the ontogenic development of elephantgrass, coordination between phytomers, stem elongation and leaf and internode coordination in main and primary axes, using an isolated plant protocol. The experiment was conducted in Piracicaba, SP, during the Spring (2015), Summer (2016) and Autumn (2016), using a complete randomized block design, with 4 replicates. Eighty fiber cement tanks (0.343 m3) were used. Each block was composed of 20 tanks, 10 used to evaluate the morphogenic and developmental characteristics and 10 for the destructive evaluations. Measurements of leaf and stem elongation were performed every two days to determine the following variables: leaf appearance rate (LAR), leaf elongation rate (LER), leaf elongation duration (LED) and final leaf length (FLL). From day 10 of the evaluation period in Summer and Autumn and day 25 in Spring, 10 cuts were performed for destructive assessments every 5 days. At the time of the destructive evaluations, the following variables were measured: apical meristem heigth (AMH); sheath tube length (STL); number of expanding leaves (NEL); number of expanded leaves (NEXL). Measurements of sheath length (SL) and internode length (IL) were performed only on the main axis. On the main axis LAR (0.02 leaves degree-days-1) and LER (0.26 cm degree-days-1) were constant, whereas LED and FLL increased with leaf rank on the axis. LED ranged from 150 to 280 degree-days from phytomer 10 to 20. In Autumn, due to flowering, LED decreased with leaf rank. SL increased until reaching a maximum value of approximately 10-12 cm from the phytomer 12-13 onwards. When evaluated in phyllochronic units, similar pattern was observed across seasons of the year for a common leaf rank group. However, in all seasons, higher leaf ranks presented greater LED. Higher LAR were reported for topmost primary axes and LER increased with leaf rank until reaching a maximum, remaining constant afterwards. The LED increased with leaf rank in main and primary axes. The stem elongation began from phytomer 8 on the main axis in all seasons of the year, and in earlier phytomers for the other primary axes. In the main axis, internode length ranged from 0.5-2.0 cm for phytomer 8 until reaching a maximum value of 8-10 cm for phytomers 12-13 onwards, in Spring and Summer. During Autumn, maximum values of internode length were approximately 20 cm. Internode elongation begins concomitantly with the cessation of leaf elongation, and after 5 phyllochronic units from leaf appearance. In all axes, STL increased until reaching a maximum value of approximately 12-13 cm in Summer and 11-12 cm in Spring, coinciding with the beginning of stem elongation. The ontogenic development described for elephantgrass differs from that reported for temperate forage grasses. There was a seasonality effect. Axes development presents a hierarchical and synchronized organization. However, for the upper axes and topmost phytomers behavior is different and needs to be investigated. The stem elongation process can be described by the number of produced leaves. This study provides a key element for understanding phenotypic plasticity and corresponds to an useful information to identify the onset of stem elongation in field conditons. This result can potentially be used for functional-structural plant modelling. / A caracterização do desenvolvimento ontogênico é de fundamental importância para inferir sobre estratégias de adaptação das plantas. Frequentemente, a morfogênese de gramíneas tropicais é reportada como análoga à de gramíneas de clima temperado. No entanto, gramíneas tropicais apresentam colmo ainda na fase vegetativa e com elevada disponibilidade de luz. O alongamento de colmo potencialmente altera a dinâmica do desenvolvimento, com implicações sobre o manejo do pastejo. Em condições tropicais, o capim-elefante cv. Napier é considerado uma das gramíneas mais produtivas sob condições de pastejo. Objetivou-se com esse estudo caracterizar o desenvolvimento ontogênico do capim-elefante, a coordenação entre fitômeros, o alongamento de colmo e a coordenação entre folha e entrenó em perfilhos principais e axilares, em condições de plantas isoladas. O experimento foi conduzido em Piracicaba-SP, durante a Primavera (2015), Verão (2016) e Outono (2016), utilizando um delineamento em blocos completos casualizados, com 4 repetições. Foram instalados 80 tanques de fibrocimento (0,343 m3). Cada bloco era composto por 20 tanques, sendo que 10 foram utilizados para avaliar as características morfogênicas e de desenvolvimento e os outros 10 para as avaliações destrutivas. Medições do alongamento da lâmina foliar e do colmo foram realizadas a cada dois dias, para determinação das variáveis: taxa de aparecimento de folhas (TAF), taxa de alongamento de folhas (TAlF), duração do alongamento de folhas (DAF) e comprimento final da folha (CFF). A partir do dia 10 do período de avaliação no Verão e no Outono e do dia 25 na Primavera, foram feitos 10 cortes para avaliações destrutivas, a cada 5 dias. Por ocasião das avaliações destrutivas, as seguintes variáveis foram medidas: altura do meristema apical (AMA); comprimento do tubo de bainha (CTB); número de folhas em expansão (NFE); número de folhas expandidas (NFEX). Medições da bainha foliar (BF) e do comprimento do entreno (CE) foram realizadas apenas para o eixo principal (perfilho basal). No eixo principal, a TAF (0,02 folhas graus-dias-1) e a TAlF (0,26 cm graus-dias-1) foram constantes, enquanto que a DAF e o CFF aumentou com nível de inserção da folha no perfilho. A DAF variou de 150 a 280 graus-dias do fitômero 10 ao 20. No Outono, em função do florescimento, a DAF diminuiu com o nível de inserção da folha. O comprimento da BF foi crescente até atingir um valor máximo de aproximadamente 10-12 cm do fitômero 12-13 em diante. Quando avaliado em unidades filocrônicas, padrão semelhante foi observado entre épocas do ano para um grupo comum de níveis de inserção de folhas. No entanto, em todas as estações, níveis de inserção de folhas superiores apresentaram maiores DAF. Maiores TAF foram reportadas para eixos primários (perfilhos axilares) localizados acima do nível do solo e a TAlF foi crescente com o nível de inserção da folha até atingir um nível máximo, apartir do qual foi constante. A DAF foi crescente com o nível de inserção da folha em todos os eixos. O alongamento do colmo ocorreu a partir do fitômero 8 no eixo principal em todas as estações do ano, e em fitômeros anteriores para os demais eixos primários. No eixo principal, o CE variou de 0,5-2,0 cm no fitômero 8 até atingir valores máximos de 8-10 cm do fitômero 12-13 em diante, na Primavera e Verão. No Outono, valores máximos de entrenó foram de aproximadamente 20 cm. O alongamento do entrenó inicia-se concomitantemente ao término do alogamento da folha, e a um tempo de 5 filocronos do aparecimento da folha. Em todos os eixos, o CTB aumentou até atingir um valor máximo de aproximadamente 12-13 cm no verão e 11-12 cm na primavera, momento que coincidiu com o início do alongamento do colmo. O desenvolvimento ontogênico descrito para capim-elefante diverge daquele descrito para gramíneas de clima temperado. Houve efeito de sazonalidade. O desenvolvimento dos eixos apresenta organização hierárquica e sincronizada. No entanto, para os eixos superiores e fitômeros acima do nível do solo, o comportamento é diferente. O alongamento do colmo pode ser descrito pelo número de folhas produzidas. Este estudo fornece um elemento-chave para a compreensão da plasticidade fenotítipa e informações úteis para identificar o início do alongamento do colmo no campo. Este resultado pode ser utilizado potencialmente para modelagem de processos estrutura-função da planta.

Sabemos hoje que os tumores sólidos apresentam uma composição celular heterogênia e que apenas uma pequena parcela dessas células apresenta capacidade de se proliferar e gerar novos tumores. Estudos prévios sobre a formação do câncer de mama têm sido realizados com base na combinação dos marcadores de superfície celular CD44 e CD24. Já foi demonstrado que uma subpopulação de células do câncer de mama com alta expressão de CD44 e baixa expressão de CD24 (CD44+/CD24-) tem maior capacidade de gerar tumores, quando comparadas com a subpopulação de células CD44-/CD24+. O objetivo do estudo foi identificar a taxa de células com fenótipo CD44+/CD24- presentes nos tumores mamários e relaciona-la com a taxa de comprometimento dos linfonodos axilares ipsilaterais por neoplasia, além de avaliar também sua relação com outros fatores sabidamente relacionados com mal prognóstico da paciente. Pacientes e métodos: avaliamos prospectivamente 53 amostras cirúrgicas provenientes de 42 pacientes com diagnóstico histopatológico de carcinoma de mama, quantificando as células CD44+/CD24- por citometria de fluxo. Relacionamos a porcentagem destas células encontrada em cada amostra com o comprometimento axilar, os receptores hormonais e Her-2, a idade da paciente, o grau histológico do tumor, o diâmetro patológico do tumor e o tipo histológico. Resultados: verificamos um significante aumento da população de células CD44+/CD24- no grupo de carcinomas ductais invasivos em pacientes que apresentavam metástase axilar [mediana 8,53% (3,6 71,2%)] em relação ao grupo de pacientes sem linfonodos comprometidos pela neoplasia [mediana 1,49% (0,3 17,1%)] (p=0,0002). Conclusão: concluímos então que quando estudamos vários tumores mamários invasivos de mesma classificação histológica, podemos notar que existe uma variação na quantidade de células CD44+/CD24- entre eles. Nosso estudo mostrou que essa variação está relacionada à agressividade tumoral e à sua capacidade de gerar metástases já que, tumores com maior quantidade de células CD44+/CD24- apresentam maior taxa de comprometimento dos linfonodos axilares. / It is known that solid tumors are composed by a heterogeneous combination of cells and only a small portion of these cells has the capacity to proliferate and generate new tumors. Previous studies about the breast cancer initiation have been based on a combination of CD44 and CD24cell surface markers. It has been shown that this subpopulation of breast cancer cells with high expression of CD44 and low expression of CD24 (CD44+/CD24-) has a greater capacity to generate tumors when compared with the subpopulation of cells CD44- /CD24+. The study objective was to identify whether the rate of cells with CD44+/CD24- phenotype present in breast tumors is related with the rate of ipsilateral lymph node metastasis, in addition to evaluate its relationship with other risk factors known to be related with worst prognosis. Patients and methods: we prospectively evaluated 53 surgical specimens from 42 patients with histological diagnosis of breast cancer, quantifying CD44+/CD24- cells through flow cytometry. We list the percentage of these cells found in each sample with axillary lymph node status, hormone receptors and Her-2, patient age, histological grade, pathological tumor diameter and histological tumorclassification. Results: we find a significant increase of CD44+/CD24- population in the invasive ductal carcinomas, in patients with axillary metastasis [median 8.53% (3.6 - 71.2%)] than in the group of patients without lymph nodes metastasis [median 1.49% (0.3 - 17.1%)] (p = 0.0002). Conclusion: when we studied several invasive breast tumors of same histological classification, we note that there is variation in the number of CD44+/CD24- cells. Our study showed that this variation is related to tumor aggressiveness and their ability to generate metastasis, because tumors with high rate of CD44+/CD24- cells have a higher rate of lymph node metastasis.