Haematopoietic properties of ethanolic extract of Ageratum conyzoides (Goat weed) in Albino rats.

The potential haematological effects associated with the administration of ethanolic leaf extract of Ageratum conyzoides was investigated in rats. 27 rats were randomly divided into four groups. The first group had 6 rats and served as control, the remaining 3 experimental groups and had 7 rats each. These later groups were gavaged with the extract of Ageratum conyzoides in concentrations of 200 mg/kg, 400 mg/kg and 500 mg/kg respectively for 30 days at a dose of 0.1 ml/body weight. The control group was gavaged with 0.9% sodium chloride at a dose of 0.1 m1/body weight as placebo. The extract at the doses administered was found to increase in a dose-related fashion PCV and Hb ([P < 0.01] for 200 mg/kg and [P < 0.001] for 400 mg/kg and 500 mg/kg), RBC ([P < 0.05] for 400 mg/Kg and 500 mg/kg) and marginal increases that were not significant for 200 mg/kg); MCH and MCV ([P < 0.05] and [P < 0.01] for 400mg/kg and 500mg/kg respectively) 200 mg/kg was not significant. MCHC recorded no significant change. WBC recorded marginal increases that were not significant, similarly, the differential white blood cell recorded marginal increases that were not significant, except lymphocytes that recorded significant increase in group 4 [P < 0.05]. Marginal Decreases in body weight were also observed, these decreases were however not significant. The result of this study thus indicate haematopoietic potentials of the extract and could possibly remedy anaemia.     

N-Glycosylation-dependent Control of Functional Expression of Background Potassium Channels K2P3.1 and K2P9.1

Two-pore domain potassium (K_2P) channels play fundamental roles in cellular processes by enabling a constitutive leak of potassium from cells in which they are expressed, thus influencing cellular membrane potential and activity. Hence, regulation of these channels is of critical importance to cellular function. A key regulatory mechanism of K_2P channels is the control of their cell surface expression. Membrane protein delivery to and retrieval from the cell surface is controlled by their passage through the secretory and endocytic pathways, and post-translational modifications regulate their progression through these pathways. All but one of the K_2P channels possess consensus N-linked glycosylation sites, and here we demonstrate that the conserved putative N-glycosylation site in K_2P3.1 and K_2P9.1 is a glycan acceptor site. Patch clamp analysis revealed that disruption of channel glycosylation reduced K_2P3.1 current, and flow cytometry was instrumental in attributing this to a decreased number of channels on the cell surface. Similar findings were observed when cells were cultured in reduced glucose concentrations. Disruption of N-linked glycosylation has less of an effect on K_2P9.1, with a small reduction in number of channels on the surface observed, but no functional implications detected. Because nonglycosylated channels appear to pass through the secretory pathway in a manner comparable with glycosylated channels, the evidence presented here suggests that the decreased number of nonglycosylated K_2P3.1 channels on the cell surface may be due to their decreased stability.     

The physiological target for LeuRS translational quality control is norvaline

The fidelity of protein synthesis depends on the capacity of aminoacyl‐tRNA synthetases (AARSs) to couple only cognate amino acid‐tRNA pairs. If amino acid selectivity is compromised, fidelity can be ensured by an inherent AARS editing activity that hydrolyses mischarged tRNAs. Here, we show that the editing activity of Escherichia coli leucyl‐tRNA synthetase (EcLeuRS) is not required to prevent incorrect isoleucine incorporation. Rather, as shown by kinetic, structural and in vivo approaches, the prime biological function of LeuRS editing is to prevent mis‐incorporation of the non‐standard amino acid norvaline. This conclusion follows from a reassessment of the discriminatory power of LeuRS against isoleucine and the demonstration that a LeuRS editing‐deficient E. coli strain grows normally in high concentrations of isoleucine but not under oxygen deprivation conditions when norvaline accumulates to substantial levels. Thus, AARS‐based translational quality control is a key feature for bacterial adaptive response to oxygen deprivation. The non‐essential role for editing under normal bacterial growth has important implications for the development of resistance to antimicrobial agents targeting the LeuRS editing site.     

Hybridization effects and genetic diversity of the common and black‐tufted marmoset (Callithrix jacchus and Callithrix penicillata) mitochondrial control region

Hybridization is continually documented in primates, but effects of natural and anthropogenic hybridization on biodiversity are still unclear and differentiating between these contexts remains challenging in regards to primate evolution and conservation. Here, we examine hybridization effects on the mitochondrial DNA (mtDNA) control region of Callithrix marmosets, which provide a unique glimpse into interspecific mating under distinct anthropogenic and natural conditions. DNA was sampled from 40 marmosets along a 50‐km transect from a previously uncharacterized hybrid zone in NE Brazil between the ranges of Callithrix jacchus and Callithrix penicillata. DNA was also collected from 46 marmosets along a 30‐km transect in a hybrid zone in Rio de Janeiro state, Brazil, where exotic marmosets appeared in the 1980s. Combining Callithrix DNA sampled inside and outside of these hybrid zones, phylogenetic and network analyses show C. jacchus and C. penicillata being parental species to sampled hybrids. We expand limited Callithrix population genetics work by describing mtDNA diversity and demographic history of these parental species. We show ancient population expansion in C. jacchus and historically constant population size in C. penicillata, with the latter being more genetically diverse than the former. The natural hybrid zone contained higher genetic diversity relative to the anthropogenic zone. While our data suggest hybrid swarm formation within the anthropogenic zone due to removed physical reproductive barriers, this pattern is not seen in the natural hybrid zone. These results suggest different genetic dynamics within natural and anthropogenic hybridization contexts that carry important implications for primate evolution and conservation. Am J Phys Anthropol 155:522–536, 2014. © 2014 Wiley Periodicals, Inc.     

Unusual presentation of plasmablastic lymphoma involving ovarian mature cystic teratoma: a case report

Background

Plasmablastic lymphoma (PBL) is relatively new clinical entity described as a distinct subtype of diffuse large B-cell lymphoma (DLBCL). It is characterized by its aggressive nature and proliferation of large neoplastic cells resembling immunoblasts including cells with more obvious plasmacytic differentiation. In this case report, we describe an unexpected finding of PBL associated with a mature cystic teratoma of the ovary in a young immune competent woman.

Case presentation

A 19-year old woman was admitted to the hospital with generalized lymphadenopathy, a pelvic tumor mass measuring 35?×?30 cm and a 4 cm lump in her right breast. She underwent a right salpingo-oophorectomy, lymphadenectomy, splenectomy, omentectomy, and a right breast lumpectomy. On macroscopic examination the right ovary was replaced by a thick-walled multilocular cystic tumor. Upon incision, the cysts were filled with thick, greasy sebaceous material and hair and there were several solid nodules within the cyst walls. Histological examination revealed a mature cystic teratoma and malignant non-Hodgkin lymphoma (NHL) within the solid nodules. Tumor tissue from the right breast, spleen and lymph nodes, all had the same histological, NHL morphology. After extensive immunostaining, a diagnosis of PBL was made. Following surgery, the patient was treated with different chemotherapy regimens, without any significant regression of the disease, and died of multiple organ failure.

Conclusions

Primary NHL of the ovary is relatively rare occurrence while secondary involvement by lymphoma is much more common. PBL is a rare lymphoma, primarily reported in the jaw and oral mucosa, but also documented in extra-oral sites. To the best of our knowledge, this is the first case described in a mature ovarian cystic teratoma. Although the patient was HIV-negative and immune competent, she had progressive disease and died despite aggressive chemotherapy 11 months after the initial diagnosis.

     

Acid sensitive background potassium channels K2P3.1 and K2P9.1 undergo rapid dynamin-dependent endocytosis

Acid-sensitive, two-pore domain potassium channels, K_2P3.1 and K_2P9.1, are implicated in cardiac and nervous tissue responses to hormones, neurotransmitters and drugs. K_2P3.1 and K_2P9.1 leak potassium from the cell at rest and directly impact membrane potential. Hence altering channel number on the cell surface drives changes in cellular electrical properties. The rate of K_2P3.1 and K_2P9.1 delivery to and recovery from the plasma membrane determines both channel number at the cell surface and potassium leak from cells. This study examines the endocytosis of K_2P3.1 and K_2P9.1. Plasma membrane biotinylation was used to follow the fate of internalized GFP-tagged rat K_2P3.1 and K_2P9.1 transiently expressed in HeLa cells. Confocal fluorescence images were analyzed using Imaris software, which revealed that both channels are endocytosed by a dynamin-dependent mechanism and over the course of 60 min, move progressively toward the nucleus. Endogenous endocytosis of human K_2P3.1 and K_2P9.1 was examined in the lung carcinoma cell line, A549. Endogenous channels are endocytosed over a similar time-scale to the channels expressed transiently in HeLa cells. These findings both validate the use of recombinant systems and identify an endogenous model system in which K_2P3.1 and K_2P9.1 trafficking can be further studied.     

An analysis of fish distribution in Kainji lake Nigeria

The distribution of fish in the three major habitats (inshore, surface and bottom) in Kainji Lake was studied using gill-nets in graded fleets each consisting of seven nets with mesh sizes ranging from 5 cm to 18 cm. No significant difference was observed in the annual yields of fish in the three habitats. Three of the nine major families, however, gave higher yields in selected habitats. Characidae and Cichlidae were most abundant in the shore and surface and Bagridae in the shore and bottom. Catches of the Cichlidae in the surface were limited to areas where the mean depth was below 7 meters. Analysis of variance showed no significant difference in the overall yields of fish among sampling areas located within the major strata of the lake. Although a general trend was observed in the seasonal yields of fish, with higher yields during low water, the variations were not significant either for the overall annual yields or among sets. The implications of these findings in relation to the mode of life of the major fish species and the stability of the fish population are discussed.     

The small pyramidal neuron of the rat cerebral cortex

Summary The pyramidal neurons in layers II and III of the rat parietal cortex have dendritic spines which form synapses with axon terminals. These synapses have synaptic clefts containing granular material that is concentrated towards the middle of the cleft to form a plaque. Only a small amount of dense material occurs on the cytoplasmic face of the presynaptic membrane, while there is a prominent dense layer, some 300 Å deep, in the dendritic spine. When the synapses formed by the smallest dendritic spines are examined in a frontal or en face plane of section this postsynaptic density has the form of a disc. In the synapses on larger spines, the disc is perforated to form a ring, and in the largest spines a number of perforations may occur. Because of these perforations, in larger synapses sections passing at right angles to the plane of the synaptic junction may show two or more separate postsynaptic densities. The possible significance of these findings is discussed.This work was supported by United States Public Health Service Research Grant No. NB-07016 from the National Institutes of Neurological Diseases and Blindness. The authors wish to express their sincere thanks to Lawrence McCarthy and Charmian Proskauer for their valuable assistance.