Stress-elicited changes in amino acid levels of hemolymph of Aplysia californica

The effects of stress produced by noxious cutaneous stimulation on the concentration of 18 amino acids in the hemolymph of Aplysia californica were examined. The concentration of alanine and glutamate increased in response to stress and remained elevated for at least 6 h. The total amino acid concentration in the hemolymph did not change significantly in response to stress. It is concluded that stress evokes an increase in circulating alanine and glutamate levels. These factors may then act in a paracrine, endocrine, or neuroendocrine manner to modify stress-associated behaviors.Abbreviations AA amino acids(s) - bw body weight - SEM standard error of the mean - SW sea water     

GAS CHROMATOGRAPHIC–MASS SPECTROMETRIC ANALYSIS OF BIOGENIC AMINES IN IDENTIFIED NEURONS AND TISSUES OF HIRUDO MEDICINALIS

—Previous workers have reported that the colossal cells of Retzius in the segmental ganglia of the medicinal leech contain about 2.3 pmol of 5-hydroxytryptamme (5-HT)/cell body. We verify the identify of 5-HT in the Retzius cells by gas chromatography-mass spectrometry and derive concentrations of 1.3–4.1 pmol/neuron by analyses of eight individually dissected Retzius cell bodies. The Retzius cell bodies contain about 30% of the 5-HT in each ganglion. An average of 25 pmol 5-HT/mg tissue, a concentration about 500 times lower than that in the Retzius cell, was found in the fibrous, pigmented tissue surrounding the leech nervous system. We could not detect γ-aminobutyric acid, octopamine, dopamine or norepinephrine in the Retzius cells, in the pigmented tissue, or, with the possible exception of dopamine (±0.4 pmol/ganglion), in whole ganglia. Furthermore, we could not detect 5-HT in pooled samples of 100 non-chromaffin control neurons.     

Role of ultrasonography in diagnosing early rheumatoid arthritis and remission of rheumatoid arthritis - a systematic review of the literature

Introduction

Ultrasonography (US) might have an added value to clinical examination in diagnosing early rheumatoid arthritis (RA) and assessing remission of RA. We aimed to clarify the added value of US in RA in these situations performing a systematic review.

Methods

A systematic literature search was performed for RA, US, diagnosis and remission. Methodological quality was assessed; the wide variability in the design of studies prohibited pooling of results.

Results

Six papers on the added value of US diagnosing early RA were found, in which at least bilateral metacarpophalangeal (MCP), wrists and metatarsophalangeal (MTP) joints were scanned. Compared to clinical examination, US was superior with regard to detecting synovitis and predicting progression to persistent arthritis or RA. Eleven papers on assessing remission were identified, in which at least the wrist and the MCP joints of the dominant hand were scanned. Often US detected inflammation in patients clinically in remission, irrespective of the remission criteria used. Power Doppler signs of synovitis predicted X-ray progression and future flare in patients clinically in remission.

Conclusions

US appears to have added value to clinical examination for diagnosing of RA when scanning at least MCP, wrist and MTP joints, and, when evaluating remission of RA, scanning at least wrist and MCP joints of the dominant hand. For both purposes primarily power Doppler US might be used since its results are less equivocal than those of greyscale US.     

The relation between cartilage biomarkers (C2C,C1,2C,CS846, and CPII) and the long-term outcome of rheumatoid arthritis patients within the CAMERA trial

Introduction  

The aim of this study was to investigate whether serum biomarker levels of C2C, C1,2C, CS846, and CPII can predict the long-term course of disease activity and radiographic progression early in the disease course of rheumatoid arthritis (RA).     

Involvement of metabotropic glutamate receptors in excitatory amino acid and GABA release following spinal cord injury in rat

Spinal cord injury (SCI) leads to an increase in extracellular excitatory amino acid (EAA) concentrations resulting in glutamate receptor-mediated excitotoxic events. The glutamate receptors include ionotropic (iGluRs) and metabotropic (mGluR) receptors. Of the three groups of mGluRs, group-I activation can initiate intracellular pathways that lead to further transmitter release. Groups II and III mGluRs function mainly as autoreceptors to regulate neurotransmitter release. In an effort to examine the role of mGluRs in the increase in EAAs following SCI, we administered AIDA, a potent group-I mGluR antagonist immediately after injury. To determine subtype specific roles of the group-I mGluRs, we evaluated EAA release following LY 367385 (mGluR1 antagonist) and MPEP (mGluR5 antagonist) administration. To evaluate group-II and -III mGluRs we administered APDC (group-II agonist) and L-AP4 (group-III agonist) immediately following injury; additionally, we initiated treatment with CPPG (group-II/-III antagonist) and LY 341495 (group-II antagonist) 5 min prior to injury. Subjects were adult male Sprague-Dawley rats (225-250 g), impact injured at T10 with an NYU impactor (12.5 mm drop). Agents were injected into the epicenter of injury, amino acids where collected by microdialysis fibers inserted 0.5 mm caudal from the edge of the impact region and quantified by HPLC. Treatment with AIDA significantly decreased extracellular EAA and GABA concentrations. MPEP reduced EAA concentrations without affecting GABA. Combining LY 367385 and MPEP resulted in a decrease in EAA and GABA concentrations greater than either agent alone. L-AP4 decreased EAA levels, while treatment with LY 341495 increased EAA levels. These results suggest that mGluRs play an important role in EAA toxicity following SCI.     

Simian Varicella Virus Induces Apoptosis in Monkey Kidney Cells by the Intrinsic Pathway and Involves Downregulation of Bcl-2 Expression

Simian varicella virus (SVV) causes varicella in primates, becomes latent in ganglionic neurons, and reactivates to produce zoster. SVV produces a cytopathic effect in monkey kidney cells in tissue culture. To study the mechanism by which SVV-infected cells die, we examined markers of apoptosis 24 to 64 h postinfection (hpi). Western blot analysis of virus-infected cell lysates revealed a significant increase in the levels of the cleaved active form of caspase-3, accompanied by a parallel increase in caspase-3 activity at 40 to 64 hpi. Caspase-9, a marker for the intrinsic pathway, was activated significantly in SVV-infected cells at all time points, whereas trace levels of the active form of caspase-8, an extrinsic pathway marker, was detected only at 64 hpi. Bcl-2 expression at the mRNA and protein levels was decreased by 50 to 70% throughout the course of virus infection. Release of cytochrome c, an activator of caspase-9, from mitochondria into the cytoplasm was increased by 200% at 64 hpi. Analysis of Vero cells infected with SVV expressing green fluorescent protein (SVV-GFP) at 64 hpi revealed colocalization of the active forms of caspase-3 and caspase-9 and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) staining with GFP. A significant decrease in the bcl-2 mRNA levels along with an abundance of mRNA specific for SVV genes 63, 40, and 21 was seen in the fraction of Vero cells that were infected with SVV-GFP. Together, these findings indicate that SVV induces apoptosis in cultured Vero cells through the intrinsic pathway in which Bcl-2 is downregulated.Apoptosis, a regulated form of cell death, plays a critical role in the homeostasis of multicellular organisms. Key features include membrane blebbing, chromatin condensation, and cell shrinkage. UV irradiation, deprivation of growth factors, and viral infection all cause apoptosis in cultured cells. Apoptosis is triggered by sequential activation of a group of cysteine proteases known as caspases. Apoptosis proceeds primarily through two pathways. The extrinsic pathway involves activation of caspase-8 and is initiated by ligand interaction with Fas or death receptors, while the intrinsic pathway is activated by an imbalance between proapoptotic (e.g., Bad and Bax) and antiapoptotic (e.g., Bcl-2 and Bcl-xL) proteins in mitochondria (21), resulting in release of cytochrome c from mitochondria, which in turn activates caspase-9. Bcl-2 plays an important role in cell survival (22, 32). Both caspase-8 and caspase-9 activate caspase-3, which along with other effector caspases, cleave critical cellular proteins, resulting in apoptosis.Simian varicella virus (SVV), the primate counterpart of human varicella zoster virus (VZV), produces a naturally occurring exanthematous disease that mimics human varicella (9, 18). Clinical and pathological changes produced by SVV infection of primates are similar to those produced by human varicella, and both VZV and SVV reactivate from latently infected ganglionic neurons (4, 13, 23, 33). The SVV and VZV genomes share a high degree of nucleotide homology (3, 10), and SVV-specific antibodies cross-react with human VZV in serum neutralization and complement fixation tests (5, 6, 30). Both viruses produce a cytopathic effect in monkey kidney cells in tissue culture (2, 29, 31). VZV has been shown to cause apoptosis in cultured Vero cells, human foreskin fibroblasts, and peripheral blood mononuclear cells isolated from healthy donors but not in primary human dorsal root ganglionic neurons (12, 13, 16, 28). Apoptosis is also seen in peripheral blood mononuclear cells of children infected with VZV in vivo (25). Thus, VZV-induced apoptosis may be cell type specific. The main objectives of this study were to determine if SVV induces apoptosis in cultured Vero cells, a monkey kidney cell line, and to identify the specific pathways.     

Seed dormancy release and germination characteristics of <i>Corispermum lehmannianum</i> Bunge,an endemic species in the Gurbantunggut desert of China

Seed dormancy release and germination of Corispermum lehmannianum Bunge were tested using various treatments: temperature, cold stratification, gibberelins (GA3), dry storage and sand burial. Results showed that temperature and light did not affect the germination of fresh seeds, cold stratification and GA3 could improve seed germination, whereas dry storage and sand burial did not. The germination percentage was highest at 35/20 °C after the cold stratification and GA3 treatments. Corispermum lehmannianum seeds were classified as non-deep, Type-2, physiological dormancy (PD), whose seed dormancy could be released by cold stratification and GA3.     

Differential retrotranslocation of mitochondrial Bax and Bak

The Bcl-2 proteins Bax and Bak can permeabilize the outer mitochondrial membrane and commit cells to apoptosis. Pro-survival Bcl-2 proteins control Bax by constant retrotranslocation into the cytosol of healthy cells. The stabilization of cytosolic Bax raises the question whether the functionally redundant but largely mitochondrial Bak shares this level of regulation. Here we report that Bak is retrotranslocated from the mitochondria by pro-survival Bcl-2 proteins. Bak is present in the cytosol of human cells and tissues, but low shuttling rates cause predominant mitochondrial Bak localization. Interchanging the membrane anchors of Bax and Bak reverses their subcellular localization compared to the wild-type proteins. Strikingly, the reduction of Bax shuttling to the level of Bak retrotranslocation results in full Bax toxicity even in absence of apoptosis induction. Thus, fast Bax retrotranslocation is required to protect cells from commitment to programmed death.