Search

Maternal effects on offspring viability significantly contribute to the productivity and resilience of exploited marine fish populations. The temporal trend of biomass of chub mackerel (Scomber japonicus) in the western North Pacific showed cyclic fluctuation patterns, but it has been rapidly increasing since 2011. Although there are several assumptions regarding the mechanisms of the population dynamics of this species in these waters, there is a contradiction in the effects of thermal environmental conditions on recruitment success. We explored the effects of maternal age and/or previous spawning experience on egg and offspring traits of captive chub mackerel in response to thermal conditions. Moreover, from the relationship between the growth rate and temperature experienced by captive fish, the experienced temperatures of wild specimens were assessed. The sizes of eggs spawned from females aged 1–3 years were negatively correlated with temperature, but the effects of maternal age on egg size and nutrition were significant with larger and nutrient-rich eggs spawned from 2- or 3-year-old females (repeat spawners) than those from 1-year-old females (first-time spawners) at a given temperature. Such temperature- and maternal-age-dependent egg traits reflected the standard length of first-feeding larvae. The effects of maternal age on the starvation tolerance of larvae after hatching and body sizes of first-feeding larvae were also evident in larvae derived from 3-year-old females showing longer starvation tolerance and larger body heights than those from 1-year-old females. Further, larvae derived from 3-year-old females grew significantly faster than those from 1-year-old females at the tested temperatures. The process of ontogenetic development and growth rate of captive specimens until age 25 days were positively correlated with temperature. Meanwhile, the estimated temperatures experienced by wild specimens until age 25 days ranged from 18.0 to 20.3°C. These findings suggested that there were opposing thermal responses between maternal and offspring traits of chub mackerel, but the temperatures experienced by the main recruit fish may be restricted within the range of temperatures available for spawning. We discuss the mechanisms of reproductive success of this species in accordance with the maternal spawning experience and thermal effects on life history traits.

Aim. This study was aimed to clarify the effectiveness of conservative treatment without performing early colonoscopy and the indications for early colonoscopy in patients with colonic diverticular hemorrhage. Methods. This retrospective study included 142 participants who were urgently hospitalized due to bloody stools and were diagnosed with colonic diverticular hemorrhage between April 2012 and December 2016. At the time of hospital visit, only when both shock based on vital signs and intestinal extravasation on abdominal contrast-enhanced computed tomography were observed, early colonoscopy was performed within 24 hours after hospitalization. However, in other cases, patients were conservatively treated without undergoing early colonoscopy. In cases of initial treatment failure in patients with shock, interventional radiology (IVR) was performed without undergoing early colonoscopy. Results. Conservative treatment was performed in 137 (96.5%) patients, and spontaneous hemostasis was achieved in all patients. By contrast, urgent hemostasis was performed in five (3.5%) patients; three and two attained successful hemostasis via early colonoscopy and IVR, respectively. There were no significant differences between two groups in terms of early rebleeding (7.3% vs. 0%,P=0.690) and recurrent bleeding (22.7% vs. 20.0%, P=0.685). The factors associated with the cumulative recurrent bleeding rates were a previous history of colonic diverticular hemorrhage (hazard ratio 5.63, 95% confidence interval 2.68–12.0, P

Capital breeders develop gametes by using energy that was stored before the spawning season. Energy is allocated to growth and reproduction, and limited food availability affects the balance of energy allocation, especially in fish that mature within a year, such as western sand lance (Ammodytes japonicus). This species aestivates without feeding until winter spawning and utilize energy stores that were accumulated prior to aestivation for maturation and spawning. This study aimed to evaluate the growth, energy storage, maturation rate, and reproduction of A. japonicus in response to food availability before aestivation. We conducted laboratory experiments in which young-of-the-year A. japonicus were fed at rates of 4% and 1% of their body weight per day; assigned as high and low ration groups, respectively. In June, body length was found to be significantly larger in the high ration group than in the low ration group, but the somatic condition did not differ significantly between the groups. Maturation rates and average fecundities were 1.0 and 6297 in the high ration group and 0.8 and 2251 in the low ration group, respectively. These results indicate that food availability before aestivation strongly governs the reproductive potential of A. japonicus, and suggest the involvement of mechanisms in the inter-annual recruitment variation in sand lance species.

Omphalocele is a human congenital anomaly in ventral body wall closure and may be caused by impaired formation of the primary abdominal wall (PAW) and/or defects in abdominal muscle development. Here, we report that mice doubly deficient in homeobox genes Six4 and Six5 showed the same ventral body wall closure defects as those seen in human omphalocele. SIX4 and SIX5 were localized in surface ectodermal cells and somatic mesoderm-derived mesenchymal and coelomic epithelial cells (CECs) in the PAW. Six4−/−;Six5−/− fetuses exhibited a large omphalocele with protrusion of both the liver and intestine, or a small omphalocele with protrusion of the intestine, with complete penetrance. The umbilical ring of Six4−/−;Six5−/− embryos was shifted anteriorly and its lateral size was larger than that of normal embryos at the E11.5 stage, before the onset of myoblast migration into the PAW. The proliferation rates of surface ectodermal cells in the left and right PAW and somatic mesoderm-derived cells in the right PAW were lower in Six4−/−;Six5−/− embryos than those of wild-type embryos at E10.5. The transition from CECs of the PAW to rounded mesothelial progenitor cells was impaired and the inner coelomic surface of the PAW was relatively smooth in Six4−/−;Six5−/− embryos at E11.25. Furthermore, Six4 overexpression in CECs of the PAW promoted ingression of CECs. Taken together, our results suggest that Six4 and Six5 are required for growth and morphological change of the PAW, and the impairment of these processes is linked to the abnormal positioning and expansion of the umbilical ring, which results in omphalocele.

Summary The mammalian cerebral cortex develops from proliferative apical progenitor cells (APs) that exhibit cell cycle-dependent nuclear movement (interkinetic nuclear migration; INM), which may be important for efficient and continuous production of neurons. The Pax6 transcription factor plays a major role in INM by regulating various downstream molecules. We have previously observed abnormal INM and unstable localization of the centrosome in APs of the Pax6 homozygous mutant rat embryo. To understand the mechanisms of INM, we focused on the centrosomes of APs. One of the centrosomal proteins, ninein, is specifically localized in the centrosome of APs. We observed a dramatic downregulation of ninein in APs of the Pax6 mutant. Moreover, knockdown of ninein by RNAi induced ectopic distribution of reduced numbers of BrdU-positive (S-phase) and PH3-positive (M-phase) cells. Furthermore, time-lapsed imaging demonstrated that knockdown of ninein in vivo induced abnormal INM. Finally, we observed impaired microtubule regrowth in neural progenitors taken from Pax6 homozygous mutant rat embryos, which was recovered by via ninein overexpression. We also found that ninein knockdown enlarged the surface size area of apical endfeet of the APs. Our results suggest that ninein plays a role in the molecular machinery essential for INM by connecting microtubules to the centrosome.

Antimitochondrial antibody (AMA) is one of the representative features of primary biliary cirrhosis (PBC). PBC is a female-dominant disease usually presenting intrahepatic bile duct destruction, cholestasis and fibrosis with or without chronic nonsuppurative destructive cholangitis. We presented the case of a 63-year-old man with acute liver failure who had AMA, pronounced alanine aminotransferase elevation and high bilirubinemia. We administered corticosteroids and rescued this patient without liver transplantation. It is well known that some patients within the spectrum of autoimmune liver disease present with characteristics of both PBC and autoimmune hepatitis. Although corticosteroids may be associated with a significant worsening of adverse events in patients with PBC, if acute liver failure in AMA-positive cases is progressive, the administration of corticosteroids has to be considered, as well as the preparation of urgent liver transplantation.

The key role of the respiratory neural center is respiratory rhythm generation to maintain homeostasis through the control of arterial blood pCO2/pH and pO2 levels. The neuronal network responsible for respiratory rhythm generation in neonatal rat resides in the ventral side of the medulla and is composed of two groups; the parafacial respiratory group (pFRG) and the pre-Bötzinger complex group (preBötC). The pFRG partially overlaps in the retrotrapezoid nucleus (RTN), which was originally identified in adult cats and rats. Part of the pre-inspiratory (Pre-I) neurons in the RTN/pFRG serves as central chemoreceptor neurons and the CO2 sensitive Pre-I neurons express homeobox gene Phox2b. Phox2b encodes a transcription factor and is essential for the development of the sensory-motor visceral circuits. Mutations in human PHOX2B cause congenital hypoventilation syndrome, which is characterized by blunted ventilatory response to hypercapnia. Here we describe the generation of a novel transgenic (Tg) rat harboring fluorescently labeled Pre-I neurons in the RTN/pFRG. In addition, the Tg rat showed fluorescent signals in autonomic enteric neurons and carotid bodies. Because the Tg rat expresses inducible Cre recombinase in PHOX2B-positive cells during development, it is a potentially powerful tool for dissecting the entire picture of the respiratory neural network during development and for identifying the CO2/O2 sensor molecules in the adult central and peripheral nervous systems.

This paper deals with the application of a simple adaptive algorithm for robust tracking control of an electro-pneumatic clutch actuator with output feedback. We present a mathematical model of the strongly nonlinear system, and implement an adaptive algorithm, based on a parallel feedforward compensator (PFC) to remove the relative-degree-1 restriction. We propose a practical method of constructing the PFC, and introduce a simple modification that removes an inherent restriction on bandwidth of the nonlinear system. We show that the adaptive algorithm deals well with nonlinearities, and we achieve tracking corresponding to a settling-time of 150 ms.

To confirm the clinical significance of NF-κB and JNK protein expression from experimentally identified candidates for predicting prognosis for patients with 5-FU treatment, we evaluated the protein expression of surgically removed specimens. A total of 79 specimens were obtained from 30 gastric and 49 colorectal cancer patients who underwent R0 resection followed by postoperative 5-FU based adjuvant chemotherapy. Immunohistochemical examinations of NF-κB and JNK on tissue microarrays (TMAs) revealed that significantly shorter time-to-relapse (TTR) in both NF-κB(+) and JNK(-) subgroups in both gastric (NF-κB(+), p = 0.0002, HR11.7. 95%CI3 3.2-43.4; JNK(-), p = 0.0302, HR4.4, 95%CI 1.2-16.6) and colon (NF-κB(+), p = 0.0038, HR36.9, 95%CI 3.2-426.0; JNK(-), p = 0.0098, HR3.2, 95%CI 1.3-7.7) cancers. These protein expression patterns also show strong discriminately power in gastric cancer patients for overall survival rate, suggesting a potential utility as prognostic or chemosensitivity markers. Baseline expression of these proteins using gastric cancer cell lines demonstrated the reciprocal patterns between NF-κB and JNK, while 5-FU exposure of these cell lines only induced NF-κB, suggesting that NF-κB plays a dominant role in the response to 5-FU. Subsequent siRNA experiments confirmed that gene knockdown of NF-κB increased 5-FU-specific sensitivity, whereas that of JNK did not affect the chemosensitivity. These results suggest that the expression of these proteins may aid in the decisions involved with adjuvant chemotherapy for gastrointestinal tract cancers.

The mammalian neocortex is characterized as a six-layered laminar structure, in which distinct types of pyramidal neurons are distributed coordinately during embryogenesis. In contrast, no other vertebrate class possesses a brain region that is strictly analogous to the neocortical structure. Although it is widely accepted that the pallium, a dorsal forebrain region, is specified in all vertebrate species, little is known of the differential mechanisms underlying laminated or non-laminated structures in the pallium. Here we show that differences in patterns of neuronal specification and migration provide the pallial architectonic diversity. We compared the neurogenesis in mammalian and avian pallium, focusing on subtype-specific gene expression, and found that the avian pallium generates distinct types of neurons in a spatially restricted manner. Furthermore, expression of Reelin gene is hardly detected in the developing avian pallium, and an experimental increase in Reelin-positive cells in the avian pallium modified radial fiber organization, which resulted in dramatic changes in the morphology of migrating neurons. Our results demonstrate that distinct mechanisms govern the patterns of neuronal specification in mammalian and avian pallial development, and that Reelin-dependent neuronal migration plays a critical role in mammalian type corticogenesis. These lines of evidence shed light on the developmental programs underlying the evolution of the mammalian specific laminated cortex.