Structure of the Pseudorabies Virus Capsid: Comparison with Herpes Simplex Virus Type 1 and Differential Binding of Essential Minor Proteins

The structure of pseudorabies virus (PRV) capsids isolated from the nucleus of infected cells and from PRV virions was determined by cryo-electron microscopy (cryo-EM) and compared to herpes simplex virus type 1 (HSV-1) capsids. PRV capsid structures closely resemble those of HSV-1, including distribution of the capsid vertex specific component (CVSC) of HSV-1, which is a heterodimer of the pUL17 and pUL25 proteins. Occupancy of CVSC on all PRV capsids is near 100%, compared to ~ 50% reported for HSV-1 C-capsids and 25% or less that we measure for HSV-1 A- and B-capsids. A PRV mutant lacking pUL25 does not produce C-capsids and lacks visible CVSC density in the cryo-EM-based reconstruction. A reconstruction of PRV capsids in which green fluorescent protein was fused within the N-terminus of pUL25 confirmed previous studies with a similar HSV-1 capsid mutant localizing pUL25 to the CVSC density region that is distal to the penton. However, comparison of the CVSC density in a 9-Å-resolution PRV C-capsid map with the available crystal structure of HSV-1 pUL25 failed to find a satisfactory fit, suggesting either a different fold for PRV pUL25 or a capsid-bound conformation for pUL25 that does not match the X-ray model determined from protein crystallized in solution. The PRV capsid imaged within virions closely resembles C-capsids with the addition of weak but significant density shrouding the pentons that we attribute to tegument proteins. Our results demonstrate significant structure conservation between the PRV and HSV capsids.     

Short-term variations of mycosporine-like amino acids in the carrageenan-producing red macroalga Mazzaella laminarioides (Gigartinales,Rhodophyta) are related to nitrate availability

Journal of Applied Phycology - The effect of solar UV radiation exposure and NO3– supply on mycosporine-like amino acids (MAAs) accumulation in the carrageenan-producing red macroalga...     

VE-cadherin-p120 interaction is required for maintenance of endothelial barrier function

Interaction of p120 with juxtamembrane domain (JMD) of VE-cadherin has been implicated in regulation of endothelial cell-cell adhesion. We used a number of approaches to alter the level of p120 available for binding to VE-cadherin as a means to investigate the role of p120-VE-cadherin interaction in regulation of barrier function in confluent endothelial monolayers. Expression of an epitope-tagged fragment corresponding to JMD of VE-cadherin resulted in a decrease in endothelial barrier function as assessed by changes in albumin clearance and electrical resistance. Binding of JMD-Flag to p120 resulted in a decreased level of p120. In addition to decreasing p120 level, expression of JMD also decreased level of VE-cadherin. Expression of JMD also caused an increase in MLC phosphorylation and rearrangement of actin cytoskeleton, which, coupled with decreased cadherin, can contribute to loss of barrier function. Reducing p120 by siRNA resulted in a decrease in VE-cadherin, whereas increasing the level of p120 increased the level of VE-cadherin, demonstrating that p120 regulates the level of VE-cadherin. Overexpression of p120 was, however, associated with decreased barrier function and rearrangement of the actin cytoskeleton. Interestingly, expression of p120 was able to inhibit thrombin-induced increases in MLC phosphorylation, suggesting that p120 inhibits activation of Rho/Rho kinase pathway in endothelial cells. Excess p120 also prevented JMD-induced increases in MLC phosphorylation, correlating this phosphorylation with Rho/Rho kinase pathway. These findings show p120 plays a major role in regulating endothelial barrier function, as either a decrease or increase of p120 resulted in disruption of permeability across cell monolayers.     

Comparison of alpha- and gamma-thrombin on lung fluid balance in anesthetized sheep

We examined the effects of varying dosages of thrombin on lung fluid balance in halothane-anesthetized sheep prepared with lung lymph fistulas. A 15-min iv infusion of sublethal doses of alpha-thrombin (2.5 clotting units/micrograms), the native enzyme, at 0.6 or 1.1 nmol active enzyme/kg body wt increased the mean pulmonary arterial pressure (Ppa) and pulmonary vascular resistance (PVR) two- to threefold. Neither parameter increased in a dose-dependent manner. Platelet counts decreased 50% with both dosages. Leukocyte counts decreased 35 and 75% from base line in the low- and high-dosage groups, respectively, and reached comparable levels of 50% below base line at 60-min postinfusion in both groups. Plasma fibrinogen concentrations decreased in a dose-dependent manner preceding dose-dependent increases in pulmonary lymph flow (Qlym) and lymph protein clearance (Clym). Fibrin deposition in pulmonary vessels was greater at 30 than at 180 min postinfusion. In contrast, a 15-min iv infusion of gamma-thrombin (0.002 clotting units/micrograms), which lacks the fibrinogen recognition site, at 1.2 nmol active enzyme/kg produced no significant increases in PVR, Ppa, Qlym, or Clym. The fibrinogen concentration did not change significantly, whereas platelet and leukocyte counts decreased 25% within 15 min. Fibrin microthrombi were less prominent in pulmonary vessels. Fibrin deposition associated with intravascular coagulation may be an important factor mediating thrombin-induced increases in pulmonary transvascular fluid and protein exchange.     

Measurement of albumin permeability across endothelial monolayers in vitro

We have developed an experimental system to measure the permeability of the cultured endothelial monolayer. The luminal-to-abluminal flux of 125I-albumin across cultured pulmonary endothelium was expressed as a clearance rate equal to the permeability-surface area product. After clearance rate measurement for a 30-min base-line period, a test agent was added to the luminal side, and the clearance rate was remeasured during a 30-min experimental period. In control studies the base-line clearance rate was 0.343 +/- 0.017 microliter/min. After correction for the diffusional resistances of the filter and unstirred layers, the calculated permeability of the endothelial monolayer was 1.2 X 10(-5) cm/s. When culture medium was the test agent, the experimental clearance rate was unchanged from the base-line value. After addition of 4 mM oleic acid to the luminal chamber, the clearance rate was 0.528 +/- 0.017 microliter/min compared with a base-line value of 0.330 +/- 0.008 microliter/min (P less than 0.005). This method allows the calculation of endothelial permeability with correction for unstirred layers and the use of each monolayer as its own control.     

Mental patients in prisons

Mental conditions usually affect cognitive, emotional and volitional aspects and functions of the personality, which are also functions of interest in law, as they are essential at the time of adjudicating guilt, labeling the accused a criminal, and proffering a sentence. A relationship between mental illness and criminality has, thus, been described and given as one of the reasons for the large number of mental patients in prisons. Whether this relationship is one of causality or one that flows through many other variables is a matter of debate, but there is no debating that prisons have become a de facto part, and an important one, of mental health systems in many countries. This paper deals with the issue of the relationship and provides estimates of prevalence of mental patients in prisons culled from many studies in different countries. It also provides some direction for the management of mental patients as they crowd correctional systems.