The idea that females of most mammalian species have lost the capacity for oocyte production at birth has been challenged recently by the finding that juvenile and adult mouse ovaries possess mitotically active germ cells. However, the existence of female germline stem cells (FGSCs) in postnatal mammalian ovaries still remains a controversial issue among reproductive biologists and stem cell researchers. We have now established a neonatal mouse FGSC line, with normal karyotype and high telomerase activity, by immunomagnetic isolation and culture for more than 15 months. FGSCs from adult mice were isolated and cultured for more than 6 months. These FGSCs were infected with GFP virus and transplanted into ovaries of infertile mice. Transplanted cells underwent oogenesis and the mice produced offspring that had the GFP transgene. These findings contribute to basic research into oogenesis and stem cell self-renewal and open up new possibilities for use of FGSCs in biotechnology and medicine.

Topographically, the AOT occurs in peripheral and central variants, the latter further in follicular (with embedded tooth) and extrafollicular (no embedded tooth) types. The AOT is slow growing with few or no symptoms. Tumor growth may cause displacement of teeth rather than root resorption. The follicular AOT mimics a follicular cyst, the extrafollicular a residual or "globulo-maxillary" cyst and the peripheral a gingival fibroma. All variants of AOT show identical histologic features. The central variants account for 97.2%, 73.0% of which are follicular. The follicular variant (M:F ratio 1 to 1.9) is three times as frequent as the extrafollicular. The follicular variant is diagnosed earlier in life (mean age 17 yr) than the extrafollicular (mean age 24 yr). 53.1% of all variants occur within the teens (13-19 yr). Follicular AOT is associated with one embedded tooth in 93.2%. Maxillary permanent canines account for 41.7% and all four canines for 60.1% of AOT-associated embedded teeth. Ranking four among the odontogenic tumors the AOT is not a particularly rare tumor. Conservative surgical excision is the treatment of choice. Documented recurrences have not been reported.

Interaction between commensal bacteria and intestinal epithelial cells (i-ECs) via TLRs is important for intestinal homeostasis. In this study, we found that the numbers of CD8αα TCRαβ and TCRγδ intestinal intraepithelial lymphocytes (i-IELs) were significantly decreased in MyD88-deficient (−/−) mice. The expression of IL-15 by i-ECs was severely reduced in MyD88−/− mice. Introduction of IL-15 transgene into MyD88−/− mice (MyD88−/− IL-15 transgenic mice) partly restored the numbers of CD8αα TCRαβ and TCRγδ i-IELs. The i-IEL in irradiated wild-type (WT) mice transferred with MyD88−/− bone marrow (BM) cells had the same proportions of i-IEL as WT mice, whereas those in irradiated MyD88−/− mice transferred with WT BM cells showed significantly reduced proportions of CD8αα TCRαβ and TCRγδ i-IELs, as was similar to the proportions found in MyD88−/− mice. However, irradiated MyD88−/− IL-15 transgenic mice transferred with WT BM cells had increased numbers of CD8αα TCRαβ and TCRγδ subsets in the i-IEL. These results suggest that parenchymal cells such as i-ECs contribute to the maintenance of CD8αα TCRαβ and γδ i-IELs at least partly via MyD88-dependent IL-15 production.

A combined analysis using conventional MRI, DWI and DCE-MRI is helpful in distinguishing benign from malignant tumours in the parotid gland.

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We were able to fit multiple echo time MRI data with high accuracy using the developed model. Parameters of the model likely capture information on microstructural and susceptibility-induced changes in the human brain. Magn Reson Med 77:1485-1494, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Parotid MALT lymphoma is characterized mainly by the solid-cystic form, whereas non-MALT lymphoma is characterized mainly by the solid form. The differences on CT and MRI can offer helpful information for differentiation of both types of parotid NHL.

Objective: The aim of this study was to evaluate the patient demographic and CT imaging findings of primary osteosarcoma of the jaws. Methods: 88 primary osteosarcomas of the jaws histopathologically diagnosed during 1997-2007 were reviewed. 21 cases of CT images were reviewed. Results: Of 88 patients, 51 (58%) had tumours in the mandible and 37 (42%) in the maxilla. The mean age was 37.8 years (range 9-80 years). The male-to-female ratio was 1.32:1. The mean age of patients with mandibular lesions was 41.04 years and in those with maxillary lesions it was 33.3 years. CT imaging findings were available in 21 patients. In the maxilla (n 5 9), all tumours (100%) arose from the alveolar ridge. In the mandible (n 5 12), most tumours (9 cases, 75%), arose from the ramus and/or condyle. All except two lesions had the epicentrum within the medullary cavity of the involved bone. The presence of periosteal reaction was demonstrated in 13 cases (62%). Soft-tissue extension was present in 18 lesions (86%), with calcification identified in 13 (72%). Conclusions: This study provides age, sex distribution, location and CT imaging features of primary osteosarcoma of the jaws.