Polymorphism of nuclear inclusions in carcinoma of the cervix uteri

Frequency, polymorphism and ultrastructural characteristics of the nuclear inclusion bodies encountered in cancers of the uterine cervix are reported and briefly discussed. The nuclear inclusions are grouped in three distinct types: a) nuclear bodies (comprising type I and II inclusions according to Bouteille et al.'s classification), b) inclusion of cytoplasmic origin, and c) particles of chromatic material. The ultrastructural aspects of the chromatic particles suggest an early structuration of viral chromatin into core material. There appears to be a direct relation between the frequency of chromatic particles and raised antiherpetic antibodies in the patient's sera.     

Leptin receptor signaling in midbrain dopamine neurons regulates feeding

The leptin hormone is critical for normal food intake and metabolism. While leptin receptor (Lepr) function has been well studied in the hypothalamus, the functional relevance of Lepr expression in the ventral tegmental area (VTA) has not been investigated. The VTA contains dopamine neurons that are important in modulating motivated behavior, addiction, and reward. Here, we show that VTA dopamine neurons express Lepr mRNA and respond to leptin with activation of an intracellular JAK-STAT pathway and a reduction in firing rate. Direct administration of leptin to the VTA caused decreased food intake while long-term RNAi-mediated knockdown of Lepr in the VTA led to increased food intake, locomotor activity, and sensitivity to highly palatable food. These data support a critical role for VTA Lepr in regulating feeding behavior and provide functional evidence for direct action of a peripheral metabolic signal on VTA dopamine neurons.     

Vaginocervical stimulation induces Fos in glutamate neurons in the ventromedial hypothalamus: Attenuation by estrogen and progesterone

Vaginocervical stimulation (VCS) induces the immediate-early gene product Fos in the ventromedial hypothalamus (VMH) of female rats. However, this induction is lower in ovariectomized rats that receive estradiol benzoate (EB) and progesterone (P) relative to an oil vehicle. We have observed that a substantial proportion of cells activated in the VMH by VCS stain for glutamate, and infusions of glutamate or its selective receptor agonists to the VMH inhibit both appetitive and consummatory sexual behaviors in females. This raises the possibility that VCS activates an inhibitory glutamate system in the VMH, and that ovarian steroids blunt the activation, although it is not known whether EB or P, alone or in combination, lead to this effect. The present experiment examined the ability of VCS to induce Fos in glutamate neurons in the VMH of ovariectomized rats under 4 hormonal regimens: oil, EB alone, P alone, or EB + P, following 1 or 50 distributed VCSs administered with a lubricated glass rod over the course of 1 h. Treatment with EB or P alone significantly reduced the number of glutamate neurons activated by 1 VCS, with P being more effective than EB. Treatment with EB + P also produced a significant reduction, but not to the extent of EB or P alone. Although EB and P work in synergy to activate sexual behavior in female rats, actions of EB or P alone are sufficient to blunt the ability of VCS to activate glutamate neurons in the VMH. It thus appears that ovarian steroids may “disinhibit” sexual responding, in part, by dampening the ability of VCS to activate glutamate neurons in the VMH. In turn, this may allow females to receive a sufficient number of intromissions for the activation of sexual reward and the facilitation of pregnancy.     

Simvastatin potentiates tumor necrosis factor alpha-mediated apoptosis of human vascular endothelial cells via the inhibition of the geranylgeranylation of RhoA

HMG-CoA reductase inhibitors (statins) are widely used in the treatment and prevention of atherosclerosis. Here we demonstrate that the HMG-CoA reductase inhibitor simvastatin potentiates TNFalpha-mediated apoptosis and TNFalpha signaling in human umbilical vein endothelial cells (HUVECs). While 2.5 microM simvastatin or 40 ng/ml TNFalpha alone had only a small effect on apoptosis in HUVECs, co-incubation with simvastatin and TNFalpha markedly increased apoptosis in a time- and dose-dependent manner as measured by FACS analysis of propidium iodide-stained cells. Geranylgeraniol, which serves as a substrate for the geranylgeranylation of small GTP binding proteins such as RhoA, which is required for the function and membrane localization of Rho, reversed the effect of simvastatin on apoptosis. GGTI, an inhibitor of protein geranylgeranylation, mimicked the effect of simvastatin on apoptosis and interfered with the membrane localization of RhoA. Furthermore, simvastatin increased the expression of the TNFalpha type I receptor (TNFalphaRI) with a dose dependence and a dependence on geranylgeranylation similar to that demonstrated for the potentiation of TNFalpha-mediated apoptosis. Adenoviral expression of a dominant-negative RhoA mimicked the effect of simvastatin on the expression of TNFalphaRI, while adenoviral expression of a dominant-activating RhoA mutant reversed the effect of simvastatin on the expression of TNFalphaRI. Simvastatin also potentiated TNFalpha signaling as determined by increased TNFalpha-mediated E-selectin expression. These data support the conclusion that TNFalpha signaling is under the negative control of RhoA and that statins potentiate TNFalpha signaling at least in part via interference with RhoA inhibition of TNFalpha type I receptor expression.     

NMR structures of the histidine-rich peptide LAH4 in micellar environments: membrane insertion, pH-dependent mode of antimicrobial action, and DNA transfection

The LAH4 family of histidine-rich peptides exhibits potent antimicrobial and DNA transfection activities, both of which require interactions with cellular membranes. The bilayer association of the peptides has been shown to be strongly pH-dependent, with in-planar alignments under acidic conditions and transmembrane orientations when the histidines are discharged. Therefore, we investigated the pH- and temperature-dependent conformations of LAH4 in DPC micellar solutions and in a TFE/PBS solvent mixture. In the presence of detergent and at pH 4.1, LAH4 adopts helical conformations between residues 9 and 24 concomitantly with a high hydrophobic moment. At pH 6.1, a helix-loop-helix structure forms with a hinge encompassing residues His¹⁰-Ala¹³. The data suggest that the high density of histidine residues and the resulting electrostatic repulsion lead to both a decrease in the pK values of the histidines and a less stable α-helical conformation of this region. The hinged structure at pH 6.1 facilitates membrane anchoring and insertion. At pH 7.8, the histidines are uncharged and an extended helical conformation including residues 4-21 is again obtained. LAH4 thus exhibits a high degree of conformational plasticity. The structures provide a stroboscopic view of the conformational changes that occur during membrane insertion, and are discussed in the context of antimicrobial activity and DNA transfection.     

A realistic meteorological assessment of perennial biofuel crop deployment: a Southern Great Plains perspective

Utility of perennial bioenergy crops (e.g., switchgrass and miscanthus) offers unique opportunities to transition toward a more sustainable energy pathway due to their reduced carbon footprint, averted competition with food crops, and ability to grow on abandoned and degraded farmlands. Studies that have examined biogeophysical impacts of these crops noted a positive feedback between near‐surface cooling and enhanced evapotranspiration (ET), but also potential unintended consequences of soil moisture and groundwater depletion. To better understand hydrometeorological effects of perennial bioenergy crop expansion, this study conducted high‐resolution (2‐km grid spacing) simulations with a state‐of‐the‐art atmospheric model (Weather Research and Forecasting system) dynamically coupled to a land surface model. We applied the modeling system over the Southern Plains of the United States during a normal precipitation year (2007) and a drought year (2011). By focusing the deployment of bioenergy cropping systems on marginal and abandoned farmland areas (to reduce the potential conflict with food systems), the research presented here is the first realistic examination of hydrometeorological impacts associated with perennial bioenergy crop expansion. Our results illustrate that the deployment of perennial bioenergy crops leads to widespread cooling (1–2 °C) that is largely driven by an enhanced reflection of shortwave radiation and, secondarily, due to an enhanced ET. Bioenergy crop deployment was shown to reduce the impacts of drought through simultaneous moistening and cooling of the near‐surface environment. However, simulated impacts on near‐surface cooling and ET were reduced during the drought relative to a normal precipitation year, revealing differential effects based on background environmental conditions. This study serves as a key step toward the assessment of hydroclimatic sustainability associated with perennial bioenergy crop expansion under diverse hydrometeorological conditions by highlighting the driving mechanisms and processes associated with this energy pathway.     

Evaluation of the new TNM-staging system for thymic malignancies: impact on indication and survival

Background

The objective of this study is the evaluation of the Masaoka-Koga and the International Association for the Study of Lung Cancer (IASLC)/International Thymic Malignancy Interest Group (ITMIG) proposal for the new TNM-staging system on clinical implementation and prognosis of thymic malignancies.

Methods

A retrospective study of 76 patients who underwent surgery between January 2005 and December 2015 for thymoma. Kaplan–Meier survival analysis was used to determine overall and recurrence-free survival rates.

Results

Indication for surgery was primary mediastinal tumor (n =?55), pleural manifestation (n =?17), or mediastinal recurrence (n =?4) after surgery for thymoma. Early Masaoka-Koga stages I (n =?9) and II (n =?14) shifted to the new stage I (n =?23). Advanced stages III (Masaoka-Koga: n =?20; ITMIG/IASLC: n =?17) and IV (Masaoka-Koga: n =?33; ITMIG/IASLC: n =?35) remained nearly similar and were associated with higher levels of WHO stages. Within each staging system, the survival curves differed significantly with the best 5-year survival in early stages I and II (91%). Survival for stage IV (70 to 77%) was significantly better compared to stage III (49 to 54%). Early stages had a significant longer recurrence-free survival (86 to 90%) than advanced stages III and IV (55 to 56%).

Conclusions

The proportion of patients with IASLC/ITMIG stage I increased remarkably, whereas the distribution in advanced stages III and IV was nearly similar. The new TNM-staging system presents a clinically useful and applicable system, which can be used for indication, stage-adapted therapy, and prediction of prognosis for overall and recurrence-free survival.

     

Localizing genes in Drosophila melanogaster polytene chromosomes by fluorescence in situ hybridization

This paper describes a method for the identification of single copy genes in Drosophila melanogaster polytene chromosomes, using fluorescence in situ hybridization (FISH). We demonstrate the detection of white (w) , a gene previously mapped to 1-1.5 region of the linkage map, and to 3C2 region of the cytogenetic map of X chromosome. Squash preparations of polytene chromosomes from salivary glands dissected out from third instar larvae of Drosophila melanogaster were denatured and subjected to hybridization with a digoxigenin labeled probe, corresponding to mini-white gene. The preparations were then washed and incubated with antidigoxigenin-fluorescein antibodies. After removal of the nonspecifically bound antibodies, the polytene chromosomes were counterstained with propidium iodide. Fluorescence microscopy revealed white locus in the X chromosome in a subterminal location, in agreement with the above mentioned maps. The protocol is efficient and adaptable for simultaneously multiple signal detection.     

Protein trafficking on sliding clamps

The sliding clamps of chromosomal replicases are acted upon by both the clamp loader and DNA polymerase. Several other proteins and polymerases also interact with the clamp. These proteins bind the clamp at the same spot and use it in sequential fashion. First the clamp loader must bind the clamp in order to load it onto DNA, but directly thereafter the clamp loader must clear away from the clamp so it can be used by the replicative DNA polymerase. At the end of replication, the replicase is ejected from the clamp, which presumably allows the clamp to interact with yet other proteins after its use by the replicase. This paper describes how different proteins in the Escherichia coli replicase, DNA polymerase III holoenzyme, coordinate their traffic flow on the clamp. The mechanism by which traffic flow on the beta clamp is directed is based on competition of the proteins for the clamp, where DNA structure modulates the competition. It seems likely that the principles will generalize to a traffic flow of other factors on these circular clamp proteins.