The effects of synthetic oligopeptide derived from enamel matrix derivative on cell proliferation and osteoblastic differentiation of human mesenchymal stem cells.

Enamel matrix derivative (EMD) is widely used in periodontal tissue regeneration therapy. However, because the bioactivity of EMD varies from batch to batch, and the use of a synthetic peptide could avoid use from an animal source, a completely synthetic peptide (SP) containing the active component of EMD would be useful. In this study an oligopeptide synthesized derived from EMD was evaluated for whether it contributes to periodontal tissue regeneration. We investigated the effects of the SP on cell proliferation and osteoblast differentiation of human mesenchymal stem cells (MSCs), which are involved in tissue regeneration. MSCs were treated with SP (0 to 1000 ng/mL), to determine the optimal concentration. We examined the effects of SP on cell proliferation and osteoblastic differentiation indicators such as alkaline phosphatase activity, the production of procollagen type 1 C-peptide and osteocalcin, and on mineralization. Additionally, we investigated the role of extracellular signal-related kinases (ERK) in cell proliferation and osteoblastic differentiation induced by SP. Our results suggest that SP promotes these processes in human MSCs, and that ERK inhibitors suppress these effects. In conclusion, SP promotes cell proliferation and osteoblastic differentiation of human MSCs, probably through the ERK pathway.

New device for MRI-guided surgical excision: report of a case.

A 37-year-old female was indicated to have a non-mass lesion in her left breast on ultrasonography (US) and visited our outpatient clinic. Mammography showed no findings of masses or microcalcification. Dynamic magnetic resonance imaging (MRI) showed a segmental enhanced lesion consisting of nodular and ring enhancement. A US-assisted vacuumed needle biopsy was performed, and the histological findings revealed sclerosing adenosis and apocrine metaplasia. After 1 year of follow-up, the MRI findings suggested both a benign lesion and ductal carcinoma in situ, and surgical excision was performed. We used a new device to evaluate the surgical margin on MRI. The non-mass lesion was excised according to the device-guided margin under local anesthesia. The histological findings revealed the features of mastopathy. Following excision, MRI showed no residual non-mass lesions, and the shape of the patient's left breast was maintained.

A synthetic oligopeptide derived from enamel matrix derivative promotes the differentiation of human periodontal ligament stem cells into osteoblast-like cells with increased mineralization.

BACKGROUND: In a previous study, the authors obtained a synthetic peptide (SP) for useful periodontal tissue regeneration. Periodontal ligament stem cells (PDLSCs) have multiple potentiality to contribute to tissue regeneration. The aim of this experiment is to investigate the effect of SP on human PDLSCs. METHODS: Periodontal ligament cells were obtained from healthy adult human third molars and used to isolate single PDLSC-derived colonies. The mesenchymal stem cell nature of the PDLSCs was confirmed by immunohistochemical evaluation of STRO-1 expression. Proliferation and osteoblastic differentiation were investigated by culturing PDLSCs in normal or osteogenic medium with and without SP (100 ng/mL). Osteoblast differentiation was assessed by measuring alkaline phosphatase (ALP) activity, osteocalcin production, mRNA expression of osteonectin, mineralization, and calcium deposition. RESULTS: Isolated PDLSCs were immunohistochemically positive for vimentin and STRO-1 and negative for cytokeratin. A greater number of calcified nodules were observed in osteogenic medium culture with SP than without. In the early and later stages of PDLSC culture with SP, osteonectin production and osteocalcin production were increased. SP in culture with osteogenic medium significantly enhanced proliferation of PDLSCs, as well as ALP activity, expression of osteonectin, osteocalcin production, formation of calcified nodules, and mineralization. CONCLUSIONS: SP enhances the formation of calcified nodules and osteocalcin production in the culture of PDLSCs into osteoblast-like cells and is a useful material for periodontal tissue regeneration.

MR-guided vacuum-assisted breast biopsy: is it an essential technique?

BACKGROUND: In the United States and Europe, MR-guided vacuum-assisted biopsy (VAB) is required for MR-only visible suspicious lesions that cannot be identified with mammography or ultrasonography. However, it is controversial as to whether MR-guided VAB is essential or not in Japan. The purpose of this study was to clarify the frequency of malignancy among the patients that underwent MR-guided VAB, and to discuss the need for this technique in Japan. METHODS: This study was approved by the Institutional Review Board of our hospital. A retrospective review was performed of 30 consecutive patients who had undergone MR-guided 11-gauge VAB. The biopsies were performed on a 1.5 T MR scanner using a commercially available biopsy system. All lesions seen with MRI could not be detected by mammography and second-look ultrasonography. RESULTS: All 30 lesions were assessed as category 4 or 5. The average lesion size of a mass enhancement before biopsy was 0.7 cm, and the average lesion size of a non-mass-like enhancement was 2.3 cm. The average number of cores of VAB was 19. The median time required to perform the VAB procedure was 35 min. The biopsy was successfully performed without important side effects in all patients. Histopathological findings were invasive ductal carcinoma in one (3%); ductal carcinoma in situ (DCIS) in seven (23%); and benign in 22 (73%). In one case, atypical ductal hyperplasia at VAB was upgraded to DCIS at surgical excision. CONCLUSION: MR-guided VAB can be performed safely and it is needed for MR-only visible suspicious lesions in Japan.

[Evaluation of the diagnostic efficacy of SPIO enhanced MRI in patients with focal hepatic lesions--comparison with CECT and CTAP].

The aim of this study was to compare the diagnostic efficacy of superparamagnetic iron oxide (SPIO)-enhanced MRI for the detection and diagnostic accuracy of focal liver lesions with helical contrast enhanced CT (CECT) and CT during arterial portography (CTAP). Thirty-nine patients (25 men and 14 women, mean age 63.5 years) were examined by SPIO-MRI and triple-phase CECT. Eleven of them were also examined by CTAP. There were a total of 96 confirmed focal hepatic lesions, 61 metastatic cancers in 18 patients and 35 hepatocellular carcinomas (HCCs) in 21 patients. Final diagnosis was established by operation in 25 cases, by biopsy in 7 cases, and by progression of disease on follow-up examination in the other 7 cases. The sensitivity of SPIO-MRI for HCC detection was almost equal to CECT, but that of SPIO-MRI for metastatic cancer detection, especially cancers smaller than 1 cm in size, was significantly superior to CECT. The sensitivity of SPIO-MRI for both HCC and metastatic cancer detection was almost equal to that of CTAP, but the specificity of SPIO-MRI for detection of both lesions was significantly superior to that of CTAP because CTAP produced a higher incidence of false-positive findings. In conclusion, SPIO-MRI could take the place of CTAP as a non-invasive excellent modality to determine the distribution of hepatic lesions preoperatively. SPIO-MRI could also be a useful modality to follow liver metastasis postoperatively in patients with advanced digestive cancers.