Latitudinal cline in the foraging dichotomy of loggerhead sea turtles reveals the importance of East China Sea for priority conservation

Special Issue: Biological traits, geographic distributions and species conservation in aquatic ecosystems[Aim]Quantifying the importance of habitat areas for conservation of highly migratory marine species with complex life histories can be challenging. For example loggerhead turtles (Caretta caretta) nesting in Japan forage both oceanically and neritically after their reproductive period. Here, we aimed to quantify the proportions of turtles using these two contrasting habitats (foraging dichotomy) to suggest priority conservation areas. [Location]North Pacific Ocean. [Methods]We examined the occurrence of foraging dichotomy at three nesting sites (Ishigaki, Okinoerabu Islands and Ichinomiya) based on stable isotope analysis of the egg yolks for 82 turtles and satellite tracking of post-nesting migration for 12 turtles. Moreover, we used the data of three other sites from previous studies (Yakushima Island, Minabe and Omaezaki). [Results]Two neritic foraging grounds (East China Sea and the coastal area of the Japanese archipelago), and an oceanic ground (North Pacific Ocean) were identified. We found a latitudinal cline with respect to the occurrence of foraging dichotomy; >84% of the females nesting at southern sites (Ishigaki and Okinoerabu Islands), 73% at middle sites (Yakushima Island and Minabe) and <46% at northern sites (Omaezaki and Ichinomiya) were neritic foragers; the proportion of oceanic foragers increased at northern sites. Based on the annual number of nests in the entire nesting region of Japan, satellite tracking and the latitudinal cline of foraging dichotomy, we estimated that 70% and 9% of annual nesting females in Japan utilize the neritic foraging habitat in the East China Sea and the coastal area of the Japanese archipelago, respectively, and that and 22% utilize the oceanic habitat of the North Pacific Ocean. [Main conclusions]The East China Sea represents a critical foraging habitat for the North Pacific populations of endangered loggerhead sea turtles. Our findings emphasize the need for international management to ensure their protection

Increased number of CD16(+)CD56(dim) NK cells in peripheral blood mononuclear cells after allogeneic cord blood transplantation

In the present study, we investigated subpopulations of NK cells and the expression of stimulatory and inhibitory NK receptors after adult blood and bone marrow transplantation (BBMT) and cord blood transplantation (CBT). There were significant increases in CD16(+)CD56(dim) cell proportion and in absolute number in peripheral blood mononuclear cells (PBMC) during a period of 4 months to 9 months after CBT compared with these in normal PBMC, cord blood (CB), and in PBMC after BBMT. Also, increased numbers of CD16(+)CD56(dim) NK cell sustained in some patients until 4 years after CBT. This CD16(+)CD56(dim) cell subset after CBT exhibited decreased expression of NKG2A compared with that in CB and increased expression of NKG2C. Purified CD16(+)CD56(dim) cells from patients 8-9 months after CBT exhibited significantly higher levels of cytolytic activity against K562 than did purified CD16(+)CD56(bright) cells and also whole PBMC. The CD16(+)CD56(dim) cell subset with a high level of cytolytic activity significantly increased after CBT, and these cells may be responsible for NK cell-mediated immunity after CBT

Sequential chemotherapy and myeloablative allogeneic hematopoietic stem cell transplantation for refractory acute lymphoblastic leukemia

The prognosis of patients receiving allogeneic hematopoietic stem cell transplantation (HSCT) for refractory acute lymphoblastic leukemia (ALL) is very poor. To improve survival rates, we attempted to intensify the conditioning regimen with daunorubicin, vincristine, prednisolone, medium-dose etoposide, cyclophosphamide, and total body irradiation (DNR/VCR/PSL plus medium-dose VP/CY/TBI). Four patients in relapse or induction failure of B-precursor ALL without other complications underwent allogeneic HSCT. Initially, chemotherapy comprising DNR 60 mg/m2 for 3 days, VCR 1.4 mg/m2 for 1 day, and PSL 60 mg/m2 for 3 days was administered, which was followed by medium-dose VP/CY/TBI; some modifications were made for individual patients. All patients achieved engraftment and complete remission after HSCT. Regimen-related toxicities were tolerable and no patient died within 100 days. Two patients were alive without disease on days 563 and 1055. The third patient relapsed on day 951, while the fourth died on day 179 without disease. Our results indicate that intensified myeloablative HSCT should be considered for patients with refractory ALL

Successful treatment of acute myelogenous leukemia with favorable cytogenetics by reduced-intensity stem cell transplantation

Acute myelogenous leukemia (AML) with favorable cytogenetics responds well to chemotherapy. If the leukemia relapses, allogenic hematopoietic stem transplantation (allo-HSCT) is considered as a treatment option. Since the efficacy of reduced-intensity stem cell transplantation (RIST) for AML with favorable cytogenetics has not been established, we retrospectively analyzed the outcomes of allo-HSCT in AML patients according to cytogenetic risks. The outcome of allo-HSCT for AML patients with favorable cytogenetics seemed to be superior to that for AML patients with intermediate cytogenetics. In AML patients with favorable cytogenetics, the 3-year overall survival (OS) and relapse-free survival (RFS) rates were 88% and 76%, respectively, in the RIST group. Both the 3-year OS and RFS rates were 81% in the conventional stem cell transplantation (CST) group. The outcome of RIST for AML patients with favorable cytogenetics was comparable to that for patients who received CST despite the more advanced age and greater organ dysfunction in RIST group than in CST group. None of the patients died within 90 days after RIST. Moreover, there was no relapse in patients with favorable cytogenetics who were in hematological remission prior to RIST. Thus, RIST for AML patients with favorable cytogenetics in remission is safe and effective