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Microfluidic devices are attracting attention for their ability to provide a biomimetic microenvironment wherein cells are arranged in a particular pattern and provided fluidic and mechanical forces. In this study, we evaluated drug transport across Caco-2 cell layers in microfluidic devices and investigated the effects of fluid flow on drug transport and metabolism. We designed a microfluidic device that comprises two blocks of polydimethylsiloxane and a sandwiched polyethylene terephthalate membrane with pores 3.0 µm in diameter. When cultured in a dynamic fluid environment, Caco-2 cells were multilayered and developed microvilli on the surface as compared with a static environment. Drugs with higher lipophilicity exhibited higher permeability across the Caco-2 layers, as well as in the conventional method using Transwells, and the fluidic conditions had little effect on permeability. In the Caco-2 cell layers cultured in Transwells and microfluidic devices, the basal-to-apical transport of rhodamine 123, a substrate of P-glycoprotein, was greater than the apical-to-basal transport, and the presence of tariquidar, an inhibitor of P-glycoprotein, completely diminished asymmetric transport. Furthermore, fluidic conditions promoted the metabolism of temocapril by carboxylesterases. On the other hand, we showed that fluidic conditions have little effect on gene expression of several transporters and metabolic enzymes. These results provide useful information regarding the application of microfluidic devices in drug transport and metabolism studies.

Background Although a few cases of accessory breast cancer (ABC) have been reported, most were in the axillary region. We encountered an extremely rare case of ABC in the inframammary region (IMR). Case presentation The patient was a 68-year-old postmenopausal woman who had noticed a congenital accessory nipple in her left IMR with slight, occasional discharge 20 years ago. Recently, she noticed a mass under the accessory nipple and visited a nearby clinic; fine-needle aspiration cytology of the mass revealed that it was malignant. She presented to our department 2 weeks after she had noticed the mass. Physical and imaging examinations showed an irregular tumor mass 1.7 × 1.4 × 1.0 cm in size connected to the accessory nipple beneath the left normal breast. Neither distant metastasis nor lymph node swelling was observed. Ultrasound-guided core needle biopsy revealed the mass to be invasive ductal carcinoma. We diagnosed her tumor as ABC in the left IMR; cT1cN0M0: stage IA. Curative wide resection with sentinel node biopsy was performed. Intraoperative evaluation of the frozen section revealed a hot and green ipsilateral axillary lymph node that was free from carcinoma; therefore, nodal dissection was avoided. Histopathological examination including immunochemical staining revealed that the tumor was invasive ductal carcinoma arising from the accessory breast tissue, scirrhous type, 1.7 × 1.4 × 1.0 cm in size, with a solid intraductal component. There was no lymphovascular infiltration, and the surgical margin was 1.5 cm or more. The tumor was estrogen and progesterone receptor-positive, Her2/neu-negative, and had a Ki-67 labeling index of 20%. There was no involvement of the three hot and/or green nodes. The final classification was pT1cN0(sn)M0: stage IA. Letrozole 2.5 mg/day will be administered for 5 years as adjuvant hormonal therapy. Conclusions A cutaneous and/or subcutaneous lesion except for proper breast tissue on the milk line, or mammary ridge from axilla to groin may be an accessory breast tissue. Its serial abnormalities must be worried malignant potential to ductal carcinoma which needs some imaging and pathological examinations for definitive diagnosis and appropriate treatment according to the usual orthotopic breast cancer without delay.

Background The incidence of radiation-associated angiosarcoma (RAA) of the breast has been increasing, and its prognosis is reportedly poor. It is important to remove tumor tissues completely to prevent recurrence. Case presentation We report two cases of patients with RAA of the breast. Both patients had a nodule in their remaining breast a few years after undergoing breast-conserving surgery and radiation therapy for breast cancer. The nodules were diagnosed as angiosarcoma by skin biopsy and open biopsy, respectively. To determine the extent of lesion spread, mapping biopsy was performed before surgery. Both patients underwent mastectomy, extensive skin resection, and split skin grafting. Pathological findings showed that their tumors could be completely resected. After surgery, chemotherapy was performed. Conclusion In our cases, no local or distant recurrence has been detected in either patient for over 4 years. We identified the range of tumor invasion by preoperative mapping biopsy and completely resected all tumor tissue.

We report a DNA-gold nanoparticle (AuNP) hybrid hydrogel in which the AuNPs crosslink enzymatically synthesized DNA to form a gel network. PCR-elongated DNA and AuNPs act as a one-dimensional polymer and cross-linkers, respectively. The DNA-AuNP hydrogel has the functional properties of both long DNA and the AuNPs.

We successfully implemented solvent extraction of short, single-stranded RNA using reverse micelles (water-in-oil microemulsions) with a DNA-surfactant. A thrombin-binding RNA aptamer was enzymatically synthesized and purified by extraction using the reverse micellar system. The extracted RNA aptamer retained thrombin-binding activity after the extraction procedure.

Apocrine papillary lesion (APL) is difficult to diagnose as benign or malignant. We experienced an APL remaining in the body for 22 years. We present a case of a 71-year-old woman who had undergone excisional biopsy 22 years previously at the first hospital that she visited. 1 year previously, she had undergone fine-needle aspiration cytology at a second hospital, and the lesion was diagnosed as potentially malignant. She underwent core-needle biopsy at a third hospital, but whether the lesion was benign or malignant could not be definitively diagnosed. We performed right mastectomy and sentinel lymph-node biopsy, because her tumor was suspected to be malignant based on imaging means, and malignancy could not be ruled out on either biopsy or cytology. The histopathological diagnosis was tiny foci of apocrine proliferative lesion with massive hemorrhagic necrosis and no tumor metastasis in two sentinel lymph nodes. Retrospectively, we compared all of the patient’s previous specimens with the present ones, and applied the recent pathological diagnostic criteria. Although the biopsy specimen excised 22 years ago suggested an encapsulated apocrine papillary carcinoma or a papilloma with apocrine ductal carcinoma in situ, neither infiltration nor metastasis has occurred. Furthermore, neither the pathological findings nor the clinical behavior has changed over time.