Metastasizing mixed tumors (MMT) of salivary glands are inexplicably metastasize maintaining benign histology. There is no pathologic and flow cytometric analysis criteria to predict the metastasis. MMT is known to metastasize by local implantation, vascular and lymphatic embolization after multiple surgery to local recurrences of primary tumor. However, multiple metastasis including cranium and spine occurred even without surgery to the primary tumor in this case. No pathological evidence of malignancy could be found in both primary and metastatic tumor. MMT is considered as an low grade malignancy based on clinical behavior rather than histologic evidence, such as low mortality rate, long delay of metastasis after primary lesion. Cranial metastasis is also extremely rare and only two cases have been reported. We report this unusual case with a literature review.

Zeolites are micro-and meso-porous materials, generally synthesized in auto-claves under controlled temperature, pressure and humidity. With the help of organic structure directing agents (SDAs), precisely engineered pore sizes of several zeolite frameworks made of silicon-oxygen tehrahedron, allow for separation of isomeric chemical mixtures containing differently sized molecules like para-and orthoxylene. Top-down synthesis approaches involving exfoliation of a layered precursor material have led to creation of one-and one-and-half unit cell thick zeolite nanosheets [1][2][3]. However, top-down methods limit the synthesis of large area nanosheets due to the filtration steps involved. This leads to reduced separation performance of the nanosheets as compared to theoretical predictions.In this study, we have characterized by TEM, a newly developed direct, bottom-up method of fabricating large area MFI-type (3 letter zeolite framework code given by International Zeolite Association [4]) zeolite nanosheets [5]. Tracking the chronological events in growth through ex-situ BF-TEM imaging, diffraction and HAADF-STEM characterization (Figure 1), reveal that the seed particles, (i) are ~ 30 nm in size at the beginning, (ii) upon further growth elongate preferentially along b-axis of MFI-type unit cell, (iii) trigger a single rotational intergrowth leading to nucleation of a 5 nm thick, b-oriented MFI nanosheet and (iv) are rapidly encircled by a high-aspect ratio, large area diamond shaped nanosheet. Nucleation of the nanosheet is the key step during this crystal growth modality and TEM investigation of the seed and nanosheet shows that it shares a/b-twin relationship, with the seed being oriented down the a-axis when the sheet is b-oriented. Dark-field TEM reveals that the elongated seed has crystallographic misorientations, while BF-TEM imaging of extended growth periods of the particle compared with Multislice simulations [6] demonstrate the epitaxial thickening of the nanosheets. TEM operating procedures to minimize electron beam damage, Multislice simulations to understand BF-TEM images, crystallographic orientations and epitaxial thickening of the sheet will be discussed in detail [7].

No abstract

Background:The development of donor-specific antibodies (DSAs) is associated with chronic rejection, inferior graft survival, and poor quality of life. Recent HLA DR/DQ-eplets matching between donor and recipient are better predictors for the development of de novo DSAs and graft outcome. Limited data on the association between proper tacrolimus (Tac) level and HLA class II eplets-mismatch loads on kidney graft outcomes are available. Methods: We examined 194 kidney transplant recipients with molecular HLA typing by Luminex by July 2022. High total eplets MM (≥17), high all Abv eplets MM (≥7), high coefficient variability (CV, ≥17%), and high intrapatient variability (IPV, ≥13%) were defined, respectively. The purpose of our study was to evaluate whether different types of Tac levels (a nadir level, mean trough level, CV, and IPV) are associated with the development of de novo DSA and poor graft outcomes Results: The low nadir of Tac trough level (<6 ng/mL) is a risk factor for the development of de novo DR-DSA and DQ-DSA, respectively. Four different Tac tests; the low nadir of Tac level (<6 ng/mL), low mean Tac level (<7 ng/mL), high CV (≥17%), and high IPV (≥13%), were significantly associated with inferior graft survival. High low IPV and low total eplets MM showed the lowest death censored graft survival rate compared with the low/low group, as a reference. Independent predictors of graft failure on multivariate analysis were chronic ABMR, and the low nadir of Tac trough level (<6 ng/mL). Conclusions: Our study demonstrated that combined high DQ/DR-eplets mismatch with high IPV and/or low Tac trough levels were significantly associated with poor graft outcomes, respectively. We also tested four different Tac levels, which were related to inferior graft survival, but high eplets MM was not associated. Our study needs to verify whether intensifying immunosuppression improves graft outcomes among patients who have high DR, DQ-eplets mismatch.

No abstract