Void-induced cross slip of screw dislocations in fcc copper

Pinning interaction between a screw dislocation and a void in fcc copper is investigated by means of molecular dynamics simulation. A screw dislocation bows out to undergo depinning on the original glide plane at low temperatures, where the behavior of the depinning stress is consistent with that obtained by a continuum model. If the temperature is higher than 300 K, the motion of a screw dislocation is no longer restricted to a single glide plane due to cross slip on the void surface. Several depinning mechanisms that involve multiple glide planes are found. In particular, a depinning mechanism that produces an intrinsic prismatic loop is found. We show that these complex depinning mechanisms significantly increase the depinning stress

PITHD1 is essential for male fertilization

The proteasome is a protein-degrading molecular complex that is necessary for protein homeostasis and various biological functions, including cell cycle regulation, signal transduction, and immune response. Proteasome activity is finely regulated by a variety of proteasome-interacting molecules. PITHD1 is a recently described molecule that has a domain putatively capable of interacting with the proteasome. However, it is unknown as to whether PITHD1 can actually bind to proteasomes and what it does in vivo. Here we report that PITHD1 is detected specifically in the spermatids in the testis and the cortical thymic epithelium in the thymus. Interestingly, PITHD1 associates with immunoproteasomes in the testis, but not with thymoproteasomes in the thymus. Mice deficient in PITHD1 exhibit severe male infertility accompanied with morphological abnormalities and impaired motility of spermatozoa. Furthermore, PITHD1 deficiency reduces proteasome activity in the testis and alters the amount of proteins that are important for fertilization capability by the sperm. However, the PITHD1-deficient mice demonstrate no detectable defects in the thymus, including T cell development. Collectively, our results identify PITHD1 as a proteasome-interacting protein that plays a nonredundant role in the male reproductive system

PITHD1 is a proteasome-interacting protein essential for male fertilization

Hiroyuki Kondo, Takafumi Matsumura, Mari Kaneko, Kenichi Inoue, Hidetaka Kosako, Masahito Ikawa, Yousuke Takahama, Izumi Ohigashi, PITHD1 is a proteasome-interacting protein essential for male fertilization, Journal of Biological Chemistry, Volume 295, Issue 6, 2020, Pages 1658-1672, ISSN 0021-9258, https://doi.org/10.1074/jbc.RA119.011144

Insulinoma with symptoms of suspected transient ischemic attack : A case report

We report the case of a６７-year-old woman who had symptoms suggestive of a transient ischemic attack（TIA）, such as lightheadedness and transient visual changes before meals for ４ months. She experienced altered consciousness before lunch and was taken to the emergency room２weeks ago. She had repeated hypoglycemia with a blood glucose level of ３１ mg/dL. Insulin secretion was not suppressed, with an immunoreactive insulin level of １４．０ μU/mL and connecting peptide immunoreactivity of １．８３ ng/mL for occasional blood glucose levels of ４９ mg/dL. Dynamic CT revealed a １７‐mm mass enhanced during the arterial phase in the pancreatic uncinate process, suggestive of a pancreatic neuroendocrine tumor. A selective arterial secretagogue（calcium）injection test revealed the localization of insulinoma in the head of the pancreas. Therefore, pancreatoduodenectomy was performed. Hyperglycemia occurred after the surgery, and it was judged that the insulinoma was resected. This case showed TIA-like symptoms without signs of sympathetic overdrive associated with hypoglycemia. Thus, the diagnosis was delayed. Insulinoma may present with symptoms of neuroglycopenia but not autonomic activity due to hypoglycemia. Insulinoma should be distinguished in patients with unknown neurological symptoms since neuroglycopenia caused by insulinoma is diverse

Evaluation of growth status using endocrine growth indices, insulin-like growth factor (IGF)-I and IGF-binding protein-1b, in out-migrating juvenile chum salmon

This study aimed to utilize circulating insulin-like growth factor binding protein (IGFBP)-1b as a negative index of growth to evaluate the growth status of juvenile chum salmon (Oncorhynchus keta) in the ocean. First, rearing experiments using PIT-tagged juveniles were conducted to examine the relationship of circulating IGFBP-1b with growth rate of the fish in May and in June. The serum IGFBP-1b level negatively correlated with fish growth rate in both months, suggesting its utility as a negative index of growth. Next, the growth status of out-migrating juveniles in northeastern Hokkaido, Japan, was monitored for 3 years using the growth indices. Serum levels of IGF-I, a positive index of growth, in fish collected from the nearshore zone were low in May and high in June of all years. Levels of serum IGFBP-1b showed a trend opposite to that of serum IGF-I. However, the IGF-I/IGFBP-1b molar ratios well reflected the seasonal and regional trends. These findings suggest that the juveniles in June left the nearshore area under better growth conditions. The present study also suggests that the use of multiple growth indices would improve the sensitivity and accuracy to evaluate the current growth status of out-migrating juvenile chum salmon