Transcutaneous cisternal puncture for sampling of cerebrospinal fluid in awake rat.

Reported cisternal puncture methods require the anesthetization and fixation of an animal within a stereotaxic frame. To determine the effect of anesthesia and animal fixation on the central nervous system (CNS), amino acid concentrations of cerebrospinal fluid (CSF) sampled by transcutaneous cisternal puncture were compared among awake rats, pentobarbital-anesthetized rats and pentobarbital-anesthetized rats fixed in a stereotaxic frame. Although the concentrations of many amino acids in the CSF of pentobarbital-anesthetized rats were lower than in awake rats, use of the stereotaxic frame resulted in significantly increased amino acid concentrations in the CSF. These data indicate that CSF sampling by transcutaneous cisternal puncture from awake rats is a suitable method for serial measurement of drug effects on the CNS.     

Correlation of PP and PR intervals in premature low birth weight infants.

We examined the developmental change by which autonomic neural activity associated respiration modulates spontaneous firing rate of sinus (SA) node and atrioventricular (AV) conduction in premature infants born with low birth weight (LBWI). The purpose of this study was to clarify whether variation of PR is correlated with that of PP or those are independent in LBWI with immature autonomic nervous system. We investigated, therefore, whether there are spontaneous functional differences in the innervation of SA and AV nodes. Further, we evaluated the maturation of autonomic nervous system progressing in the period, on the day of birth (Day 0) to approximately one month after the birth (Month 1). This study was performed in thirteen LBWI during deep sleep. EEG, EOG, ECG, respiratory waves were digitized on line, spontaneous firing cycle of SA node (PP), and AV nodal conduction time (PR) that were recorded on Day 0 and Month 1. Then, the data were analyzed as follows: 1) correlations among the means and standard deviations (SD) of PP, PR and RR, 2) variance evaluation of PP and PR intervals by Lorenz plot analysis method, 3) correlation analysis among PP, PR and RR intervals by linear regression method and 4) frequency analysis for PP and PR intervals by high-speed Fourier transform method (FFT) and determination of frequency density. The PP interval decreased as growing in the period. Contrary PR interval increased. In LBWI, the automatic nervous activities including parasympathetic nerve activity for spontaneous firing cycle of SA node and ventricular excitation cycle on Month 1 were higher than Day 0. It was assumed that the vagal nerve activity for the AV conduction was enhanced. However, there was no significant change in linear regression slope for the spontaneous firing cycle of SA node and the AV conduction time. Postnatal LF/HF changes for PP and PR obtained by frequency analysis, were opposite. Therefore, it was suggested that the maturity of autonomic nervous system progresses in the period, Day 0 to approximately Month 1, but the variations in PP and PR are independent each other.     

l-Isoleucine (Ile) Promotes Anthocyanin Accumulation in Apples

Journal of Plant Growth Regulation - The functions of l-isoleucine (Ile) in anthocyanin biosynthesis were investigated in apple fruit. Whole trees (Malus × domestica Bokh.) were...     

Calbindin-Positive Neurons Co-express Functional Markers in a Location-Dependent Manner Within the A11 Region of the Rat Brain

The A11 region plays a role in numerous physiological functions, including pain and locomotor activity, and consists of a variety of neurons including GABAergic, calbindin positive (Calb⁺), and dopaminergic (DA) neurons. However, the neurochemical nature of Calb⁺ neurons and their regulatory role in the A11 region remain largely unknown. In this study, we examined the kind of functional markers co-expressed in the Calb⁺ neurons using sections from 8-week-old rats. To examine a marker related to classical neurotransmitters, we performed in situ hybridization for vesicular glutamate transporter 2 (vGluT2) or glutamate decarboxylase (GAD) 65 and 67, in conjunction with Calb immunohistochemistry. We found cellular co-expression of Calb with vGluT2 or GAD65/67 throughout the A11 region. Nearly all Calb⁺/GAD65/67⁺ neurons were found in the rostral-middle aspect of the A11 region. In contrast, Calb⁺/vGluT2⁺ neurons were found predominantly in the middle-caudal aspect of the A11 region. For receptors and neuropeptides, we performed immunohistochemistry for androgen receptor (AR), estrogen receptors (ERα and ERβ), and calcitonin gene-related peptide (CGRP). We found that Calb⁺ neurons co-expressed AR in the rostral aspect of the A11 region in both male and female rats. However, we rarely find cellular co-expression of Calb with ERα or ERβ in this region. For CGRP, we found both Calb⁺ neurons with or without CGRP expression. These results demonstrate that Calb⁺ neurons co-express many functional markers. Calb⁺ neurons have a distinct distribution pattern and may play a variety of regulatory roles, depending on their location within the A11 region.

     

Bortezomib Reduces the Tumorigenicity of Multiple Myeloma via Downregulation of Upregulated Targets in Clonogenic Side Population Cells

Side population (SP) cells in cancers, including multiple myeloma, exhibit tumor-initiating characteristics. In the present study, we isolated SP cells from human myeloma cell lines and primary tumors to detect potential therapeutic targets specifically expressed in SP cells. We found that SP cells from myeloma cell lines (RPMI 8226, AMO1, KMS-12-BM, KMS-11) express CD138 and that non-SP cells include a CD138-negative population. Serial transplantation of SP and non-SP cells into NOD/Shi-scid IL-2γnul mice revealed that clonogenic myeloma SP cells are highly tumorigenic and possess a capacity for self-renewal. Gene expression analysis showed that SP cells from five MM cell lines (RPMI 8226, AMO1, KMS-12-BM, KMS-11, JJN3) express genes involved in the cell cycle and mitosis (e.g., CCNB1, CDC25C, CDC2, BIRC5, CENPE, SKA1, AURKB, KIFs, TOP2A, ASPM), polycomb (e.g., EZH2, EPC1) and ubiquitin-proteasome (e.g., UBE2D3, UBE3C, PSMA5) more strongly than do non-SP cells. Moreover, CCNB1, AURKB, EZH2 and PSMA5 were also upregulated in the SPs from eight primary myeloma samples. On that basis, we used an aurora kinase inhibitor (VX-680) and a proteasome inhibitor (bortezomib) with RPMI 8226 and AMO1 cells to determine whether these agents could be used to selectively target the myeloma SP. We found that both these drugs reduced the SP fraction, though bortezomib did so more effectively than VX-680 due to its ability to reduce levels of both phospho-histone H3 (p-hist. H3) and EZH2; VX-680 reduced only p-hist. H3. This is the first report to show that certain oncogenes are specifically expressed in the myeloma SP, and that bortezomib effectively downregulates expression of their products. Our approach may be useful for screening new agents with which to target a cell population possessing strong tumor initiating potential in multiple myeloma.     

Collective Chasing Behavior between Cooperators and Defectors in the Spatial Prisoner’s Dilemma

Cooperation is one of the essential factors for all biological organisms in major evolutionary transitions. Recent studies have investigated the effect of migration for the evolution of cooperation. However, little is known about whether and how an individuals’ cooperativeness coevolves with mobility. One possibility is that mobility enhances cooperation by enabling cooperators to escape from defectors and form clusters; the other possibility is that mobility inhibits cooperation by helping the defectors to catch and exploit the groups of cooperators. In this study we investigate the coevolutionary dynamics by using the prisoner’s dilemma game model on a lattice structure. The computer simulations demonstrate that natural selection maintains cooperation in the form of evolutionary chasing between the cooperators and defectors. First, cooperative groups grow and collectively move in the same direction. Then, mutant defectors emerge and invade the cooperative groups, after which the defectors exploit the cooperators. Then other cooperative groups emerge due to mutation and the cycle is repeated. Here, it is worth noting that, as a result of natural selection, the mobility evolves towards directional migration, but not to random or completely fixed migration. Furthermore, with directional migration, the rate of global population extinction is lower when compared with other cases without the evolution of mobility (i.e., when mobility is preset to random or fixed). These findings illustrate the coevolutionary dynamics of cooperation and mobility through the directional chasing between cooperators and defectors.     

Signal Peptidase Complex Subunit 1 Participates in the Assembly of Hepatitis C Virus through an Interaction with E2 and NS2

Hepatitis C virus (HCV) nonstructural protein 2 (NS2) is a hydrophobic, transmembrane protein that is required not only for NS2-NS3 cleavage, but also for infectious virus production. To identify cellular factors that interact with NS2 and are important for HCV propagation, we screened a human liver cDNA library by split-ubiquitin membrane yeast two-hybrid assay using full-length NS2 as a bait, and identified signal peptidase complex subunit 1 (SPCS1), which is a component of the microsomal signal peptidase complex. Silencing of endogenous SPCS1 resulted in markedly reduced production of infectious HCV, whereas neither processing of structural proteins, cell entry, RNA replication, nor release of virus from the cells was impaired. Propagation of Japanese encephalitis virus was not affected by knockdown of SPCS1, suggesting that SPCS1 does not widely modulate the viral lifecycles of the Flaviviridae family. SPCS1 was found to interact with both NS2 and E2. A complex of NS2, E2, and SPCS1 was formed in cells as demonstrated by co-immunoprecipitation assays. Knockdown of SPCS1 impaired interaction of NS2 with E2. Our findings suggest that SPCS1 plays a key role in the formation of the membrane-associated NS2-E2 complex via its interaction with NS2 and E2, which leads to a coordinating interaction between the structural and non-structural proteins and facilitates the early step of assembly of infectious particles.     

Direct observation of bear myrmecophagy: Relationship between bears’ feeding habits and ant phenology

We studied the ant-feeding behavior of Asiatic black bears (Ursus thibetanus) through direct observation in the Ashio area of Japan. We recorded the bears’ “time foraging per ant nest” (TPN), documented the seasonal occurrence of ants in their scats, estimated phenological changes in caste composition of the nests of two abundant ant species (Lasius flavus and L. hayashi), and calculated the nutritional composition of queens, males, workers, queen pupae, and non-queen pupae of both species. We addressed two main hypotheses: (1) ant-nest phenology, especially the availability of pupae, affects bears’ myrmecophagy level; and (2) TPN changes according to the caste composition of ant nests. Bears in the Ashio area consumed more ants than in previous studies elsewhere in Japan, with consumption peaking in early July. The availability of pupae may trigger ant feeding by bears. And, because queen pupae were heavier than members of other castes, calories per individual were higher. TPN varied during the study period (late June–early August). There was a negative relationship between frequency of occurrence of pupae in ant nests and TPN; because pupae cannot move by themselves, bears could consume them effectively and quickly. Thus, bears may change their ant-foraging behavior (especially TPN) based on ant nest composition.     

Seasonal changes and altitudinal variation in deer fecal pellet decay

Surveying dung pellet groups to estimate population size requires knowledge of the dung decay rates in different environmental conditions. We evaluated seasonal and elevational differences in the decay rates of fresh deer pellets in the Ashio–Nikko Mountains, Japan. At each of four sites (1,500, 1,200, 900, and 600 m above sea level), we set out four replicates of 50 fresh deer pellets each month from September 2008 to August 2009. Dung pellet groups were evaluated after 24 h and again monthly. We also monitored the dung beetle fauna monthly using pitfall traps. Dung beetle activity was positively correlated with temperature, and the rate of dung decay was strongly correlated with dung beetle dry weight. Decay was most rapid during summer and at lower altitudes; pellets set out during winter did not decay until the following spring. Resource managers who use dung surveys to estimate population sizes in mountainous regions should consider the decay rates at different altitudes.