The occurrence of alternative Nod factor (NF)-independent symbiosis between legumes and rhizobia was first demonstrated in some Aeschynomene species that are nodulated by photosynthetic bradyrhizobia lacking the canonical nodABC genes. In this study, we revealed that a large diversity of non-photosynthetic bradyrhizobia, including B. elkanii, was also able to induce nodules on the NFindependent Aeschynomene species, A. indica. Using cytological analysis of the nodules and the nitrogenase enzyme activity as markers, a gradient in the symbiotic interaction between bradyrhizobial strains and A. indica could be distinguished. This ranged from strains that induced nodules that were only infected intercellularly to rhizobial strains that formed nodules in which the host cells were invaded intracellularly and that displayed a weak nitrogenase activity. In all nonphotosynthetic bradyrhizobia, the type III secretion system (T3SS) appears required to trigger nodule organogenesis. In contrast, genome sequence analysis revealed that apart from a few exceptions, like the Bradyrhizobium ORS285 strain, photosynthetic bradyrhizobia strains lack a T3SS. Furthermore, analysis of the symbiotic properties of an ORS285 T3SS mutant revealed that the T3SS could have a positive or negative role for the interaction with NF-dependent Aeschynomene species, but that it is dispensable for the interaction with all NF-independent Aeschynomene species tested. Taken together, these data indicate that two NF-independent symbiotic processes are possible between legumes and rhizobia: one dependent on a T3SS and one using a so far unknown mechanism.

Objective: This study retrospectively investigated the usefulness of intraoperative diagnosis based on imprint cytology and frozen sections for ovarian germ cell tumor. Study Design: Intraoperative studies were reviewed for 23 cases with ovarian germ cell tumor treatment for which both frozen sections and imprint cytology were available. Final histopathologic diagnoses were compared with those based on intraoperative examinations. Results: Underlying pathologies included dysgerminoma (n = 6), yolk sac tumor (n = 1), non-gestational choriocarcinoma (n = 1), mature cystic teratoma with malignant transformation (n = 1), immature teratoma (n = 11), and mixed germ cell tumor (n = 3). Discrepancies between intraoperative imprint cytology and definitive histologic diagnosis were seen in 6 of the 23 cases. Accuracy was 54.5% (6/11) for immature teratoma and 91.7% (11/12) for other tumors. Cytologic examination facilitated accurate diagnosis in both of our cases, and intraoperative diagnosis by frozen section proved inaccurate. Conclusion: These results demonstrate that intraoperative assessment based on imprint cytology for immature teratoma has a relatively lower sensitivity, but an acceptable sensitivity for other germ cell tumors. Diagnostic approaches combining frozen sections and imprint cytology are advisable to improve the yield for intraoperative diagnosis.

ObjectiveWe aimed to develop and reinforce a clinical management regimen for atypical endometrial cell (ATEC) categories within the descriptive reporting format for endometrial cytology.MethodsBetween January 2013 and December 2014, 215 samples, for which histological examination was performed immediately or within 3 months after cytology, were cytologically diagnosed as ATEC. For these samples, the medical records were retrospectively reviewed to identify risk factors for malignancy.ResultsAmong 152 samples diagnosed as ATEC, of undetermined significance, 19 (12.5%) were malignant. In the younger group (age <55 years), the χ2 values of body mass index (BMI) ≥25 kg/m2 (5.85), gravidity (5.64) and parity (5.15) were relatively high, suggesting that these were risk factors for malignancy. Of the nulligravida patients, those with BMI ≥25 kg/m2, 28% were diagnosed with malignant disease. In the older group (≥55 years), endometrial thickening (6.84), atypical genital bleeding (6.43) and BMI ≥25 kg/m2 (3.79) were found to be risk factors for malignancy. Of the patients with endometrial thickening and atypical genital bleeding, 67% were diagnosed with malignant disease. Among 63 samples diagnosed as ATEC, cannot exclude atypical endometrial hyperplasia or more, 35 (55.6%) samples were positive for malignancy.ConclusionsHigh‐risk patients diagnosed with ATEC, of undetermined significance were identified. Endometrial biopsy should be considered for nulligravida patients aged <55 years with a BMI ≥25 kg/m2.

Objective: The cytological diagnosis of coelomic fluid is essential for examining malignant mesothelioma (MM). However, reactive mesothelium (RM), caused by various factors, is morphologically similar to MM and thus often complicates the differential diagnosis. Here, nuclear luminance and steric alterations were assessed for the discriminant analysis of MM and RM. Study Design: Thirteen epithelial MM and 11 RM cases were included. One hundred alterations in the numbers of nuclear pixels and focus layers and the coefficient of variation of nuclear luminance among layers were determined for each case to conduct discriminant analysis using the Mahalanobis distance. Results: A cutoff value of 0.072 allowed highly accurate discrimination of MM (89.5%) and RM (89.6%). Fifteen cells appeared in 6 agglomerates of indiscriminable MM cases. The 6 agglomerates were individually examined. Malignant cells were dominant in 3 agglomerates (50%), allowing the discrimination of malignant cases. Conclusion: Discrimination using nuclear luminance and steric alterations is useful for morphologically indiscriminable MM cases. Three-dimensional analysis of agglomerates will be further investigated to improve the diagnostic accuracy.