Estimation of tuna population by the improved analytical pipeline of unique molecular identifier-assisted HaCeD-Seq (haplotype count from eDNA).

Many studies have investigated the ability to identify species from environmental DNA (eDNA). However, even when individual species are identified, the accurate estimation of their abundances by traditional eDNA analyses has been still difficult. We previously developed a novel analytical method called HaCeD-Seq (Haplotype Count from eDNA), which focuses on the mitochondrial D-loop sequence. The D-loop is a rapidly evolving sequence and has been used to estimate the abundance of eel species in breeding water. In the current study, we have further improved this method by applying unique molecular identifier (UMI) tags, which eliminate the PCR and sequencing errors and extend the detection range by an order of magnitude. Based on this improved HaCeD-Seq pipeline, we computed the abundance of Pacific bluefin tuna (Thunnus orientalis) in aquarium tanks at the Tokyo Sea Life Park (Kasai, Tokyo, Japan). This tuna species is commercially important but is at high risk of resource depletion. With the developed UMI tag method, 90 out of 96 haplotypes (94%) were successfully detected from Pacific bluefin tuna eDNA. By contrast, only 29 out of 96 haplotypes (30%) were detected when UMI tags were not used. Our findings indicate the potential for conducting non-invasive fish stock surveys by sampling eDNA.

Primary sellar lymphoma: intravascular large B-cell lymphoma diagnosed as a double cancer and improved with chemotherapy, and literature review of primary parasellar lymphoma.

Lymphoma is one of the causative factors of hypothalamus-pituitary dysfunction, and intravascular large B-cell lymphoma (IVLBCL) is a subtype of primary extranodal neoplasm. A 69-year-old woman visited our hospital because of general fatigue. We diagnosed her with presumable non-functional primary pituitary adenoma and subsequent dysfunction. Eight months after, the patient revisited our hospital because of dyspnea. Though we conducted systemic investigations including chest and abdomen enhanced computer tomography, transbronchial lung biopsy, and bone marrow biopsy, the diagnosis was not confirmed. Inadvertently, a breast cancer was found, and the surgical specimen proved that the patient had double cancer-adenocarcinoma and IVLBCL. Rituximab, cyclophosphamide, adriamycin, vincristine, and prednisolone regimen was initiated, and complete remission was achieved. Notably, the sellar mass returned to normal size with improved function. We reviewed 32 patients with primary parasellar lymphoma. In affected sites, both sellar and pituitary stalk (6.7%), both hypothalamus and pituitary stalk (6.7%), only sellar (63.3%), only pituitary stalk (6.7%), only hypothalamus (13.3%), and only clivus (3.3%) were observed. In hypothalamus-pituitary dysfunction, both anterior and posterior dysfunction (20.7%), only anterior dysfunction (58.6%), only posterior dysfunction (3.4%), and no dysfunction (17.2%) were observed. It seemed that hypothalamic lesion is related to both anterior and posterior dysfunction, while sellar lesion is related to mainly anterior dysfunction. In cranial nerve dysfunction, 2nd nerve dysfunction (45.2%) and 6th nerve dysfunction (35.5%) were frequently observed. It seemed that sellar lesion is related to both 2nd and 6th nerve dysfunction, while hypothalamic lesion is related to mainly 2nd nerve dysfunction.