Carbamyl Analogs of Phosphatidylcholines Synthesis, Interaction With Phospholipases and Permeability Behavior of their Liposomes

A novel class of phospholipase-resisting phosphatidylcholine analogs, in which the C-2 ester group or both C-1 and C-2 ester groups have been replaced by carbamyloxy functions (-NH-C-O-), have been synthesized. These lipids were not degraded by phospholipase A2 while complete hydrolysis occurred with phospholipase C. Ultrasonic irradiation of the aqueous dispersions of the phospholipids in the presence as well as in the absence of cholesterol resulted in the formation of closed bilayer structures as evidenced by negative staining electron microscopy and also by their ability to entrap [14C]glucose. The leakage rates of glucose at 37°C from liposomes of these compounds have also been measured. Liposomes consisting of 1,2-dipentadecanylcarbamyloxy-sn-glycero- 3-phosphorylcholine were found to be more leaky (2.1 %/h) as compared to the liposomes of 1-palmitoyl-2-pentadecanylcarbamyloxy-sn -glycero-3-phosphoryl- choline (O.5%/h). Moreover, inclusion of cholesterol (33 mol%) into the bilayers of the former phospholipid had no effect on the leakage rate (2.4%/h) while it effectively reduced permeability of the latter (O.22%/h). These phosphatidylcholines are useful for studying the possible role of phospholipases in the capture and lysis of liposomes in vivo.

Stability of liposomes in circulation is markedly enhanced by structural modification of their phospholipid component

Replacement of the C-2 ester group in phosphatidylcholine by the carbamyloxy function rendered its liposomes completely stable and longer living in the circulation of rats.

Assibi A. Amidu 2009. Matrix Nominal Phrases in Kiswahili Bantu. A Study of their Effects on Argument Syntax.

Assibi A. Amidu's contribution is undoubtedly a highly challenging one to the direct study of the Kiswahili Bantu language. Aiming at complementing the existing grammars and monographs of living languages the author intends to illuminate some paradoxes of the Kiswahili syntax and morphology. Having defined this aim he presents a clearly structured monograph to the interested reader, consisting of six chapters, relating to one another.

A view through gloomy glasses: accuracy and bias in relationships of narcissists

Narcissists’ perception of others is marked by a negative bias in the service of their own self-enhancement. The aim of this study was to determine whether narcissists’ negative bias extends to the perception of romantic partners too. In addition, we explored whether partners of narcissists succumb to specific perception biases as well. During 14 days, 86 couples completed measures of support given to and received from their partners. The results indicated that both male and female narcissists were more accurate in detecting negative support (e.g., blaming the partner for his or her problems) received from their partners, while female narcissists only were less accurate in perceiving altruistic support motives (e.g., truly enjoying to help the partner) of their male partner. Moreover, narcissists as well as their partners displayed a negative bias by underestimating the amount of altruistic support motives reported by each of them. On the other hand, partners of narcissists were positively biased as well and underestimated the negative support given by the narcissists. Results are discussed in relation to the self-regulatory goals of narcissists and of their partners and with respect to the possible impact of their accuracy and biases on the couple wellbeing.

miR-21 and its target gene CCL20 are both highly overexpressed in the microenvironment of colorectal tumors: significance of their regulation

Recently, we reported a functional interaction between miR-21 and its identified chemokine target CCL20 in colorectal cancer (CRC) cell lines. Here, we investigated whether such functional interactions are permitted at the cellular level which would require an inverse correlation of expression and also co-expression of miR-21 and CCL20 in the same cell. Expression profiling was performed using qPCR, and ELISA, in situ hybridization and immunohistochemistry were applied for the presentation of their cellular localization. We demonstrated that miR-21 as well as CCL20 were both significantly upregulated in CRC tissues; thus, showing no antidromic expression pattern. This provided an initial clue that miR-21 and CCL20 may not be expressed in the same cell. In addition, we located miR-21 expression at the cellular level predominantly in stromal cells such as tumor-associated fibroblasts and to a minor degree in immune cells such as macrophages and lymphocytes. Likewise, CCL20 expression was primarily detected in tumor-infiltrating immune cells. Thus, investigating the cellular localization of miR-21 and its target CCL20 revealed that both molecules are expressed predominantly in the microenvironment of CRC tumors.

Neutral biodiversity theory can explain the imbalance of phylogenetic trees but not the tempo of their diversification

Numerous evolutionary studies have sought to explain the distribution of diversity across the limbs of the tree of life. At the same time, ecological studies have sought to explain differences in diversity and relative abundance within and among ecological communities. Traditionally, these patterns have been considered separately, but models that consider processes operating at the level of individuals, such as neutral biodiversity theory (NBT), can provide a link between them. Here, we compare evolutionary dynamics across a suite of NBT models. We show that NBT can yield phylogenetic tree topologies with imbalance closely resembling empirical observations. In general, metacommunities that exhibit greater disparity in abundance are characterized by more imbalanced phylogenetic trees. However, NBT fails to capture the tempo of diversification as represented by the distribution of branching events through time. We suggest that population-level processes might therefore help explain the asymmetry of phylogenetic trees, but that tree shape might mislead estimates of evolutionary rates unless the diversification process is modeled explicitly.

The history of the Jews, from the taking of Jerusalem by Titus, to the present time, comprising a narrative of their wanderings, persecutions, commercial enterprises, literature, manners, customs, and forms of worship : with an account of the various efforts made for their conversion

[James A. Huie]

The present state of the Jews : wherein is contained an exact account of their customs, secular and religious ; to which is annexed a summary discourse of the Misna, Talmud, and Gemara

by L. Addison