A novel bilateral grafting technique for studying patterning in Hydra.

Control of patterning and the specification of body axes are fundamental aspects of animal development involving complex interactions between chemical, physical, and genetic signals. The freshwater polyp Hydra has long been recognized as a useful model system to address these questions due to its simple anatomy, optical transparency, and strong regenerative abilities, which enabled clever grafting experiments to alter and probe patterning. Reliable methods exist for the transplantation of small tissue pieces into the body column or the combination of sections cut perpendicular to the body axis, which can be used to examine oral-aboral gradients and axis induction potential of tissue fragments. However, existing methods do not allow researchers to probe questions of axis alignment and lateral information exchange. We therefore developed a technique to produce chimeric animals split longitudinally along the body axis of the animal by anesthetizing the animals with the terpene linalool and threading the donor pieces onto pairs of fine glass needles. Our novel approach can be applied to study questions in Hydra research that have thus far been inaccessible, including patterning processes acting perpendicular to the oral-aboral axis and the extent of lateral cell migration.

Can Breast Cancer Biopsy Influence Sentinel Lymph Node Status?

INTRODUCTION: We evaluated whether the needle size could influence metastasis occurrence in the axillary sentinel lymph node (SLN) in ultrasound-guided core needle biopsy (US-CNB) of breast cancer (BC). MATERIALS AND METHODS: The data from all patients with breast lesions who had undergone US-CNB at our institution from January 2011 to January 2015 were retrospectively reviewed. A total of 377 BC cases were included using the following criteria: (1) percutaneous biopsy-proven invasive BC; and (2) SLN dissection with histopathologic examination. The patients were divided into 2 groups according to the needle size used: 14 gauge versus 16 or 18 gauge. SLN metastasis classification followed the 7th American Joint Committee on Cancer (2010) TNM pathologic staging factors: macrometastases, micrometastases, isolated tumor cells, or negative. Only macrometastases and micrometastases were considered positive, and the positive and negative rates were calculated for the overall population and for both needle size groups. RESULTS: Of the 377 BC cases, 268 US-CNB procedures were performed using a 14-gauge needle and 109 with a 16- or 18-gauge needle, respectively. The negative rate was significantly related statistically with the needle size, with a greater prevalence in the 14-gauge group on both extemporaneous analysis (P = .019) and definitive analysis (P = .002). The macrometastasis rate was 17% (63 of 377) for the 14-gauge and 3% (12 of 377) for the 16- and 18-gauge needles, respectively. CONCLUSION: Our preliminary results have suggested that use of a large needle size in CNB does not influence SLN status; thus, preoperative breast biopsy can be considered a safe procedure in the diagnosis of malignant breast lesions.