Evidence for Early Bacteremia/Endotoxemia and Inflammatory Responses after Trauma - Hemorrhage and Complement Activation in a Nonhuman Primate Model

There is criticism that the major line of evidence regarding posttraumatic inflammatory response and bacterial translocation has mainly come from experiments in rodents. The aim of this study was therefore to investigate the very early bacteremia/endotoxemia and inflammatory response in nonhuman primates. Six baboons were subjected to hemorrhagic shock (40 mm Hg mean arterial pressure) preceded by infusion of zymosan-activated plasma (to simulate trauma-associated complement activation) followed by reinfusion for 1 h. Measurements of complement and granulocyte (PMN) activation, cytokines of the inflammatory network, soluble cytokine receptors, and bacteria/endotoxin translocation (BT) were performed. There were significantly increased levels of PMN elastase, interleukin-6, and soluble tumor necrosis factors (TNF) receptors, but not of TNF. BT was evident from positive blood cultures, and from trendwise increased endotoxin plasma levels. Early liver damage was shown from elevated glutathione S-transferase (GST) plasma levels. Complement activation and hemorrhagic shock lead to an early inflammatory response together with bacteremia/endotoxemia as evidence of translocation from the gut already during the shock period in subhuman primates.     

Synthesis of optimal feedback guidance law for homing missiles using neural networks

Most existing missiles are guided by proportional navigation guidance (PNG) law, but PNG is a particular case for LQ guidance rule with two main assumptions of small line‐of‐sight angles and negligible acceleration along the line‐of‐sight. However, most missile engagements exceed these limits because of high tangential and normal accelerations. Unfortunately, it is not possible to determine the feedback guidance law for non‐linear systems such as homing missiles in real‐time. We use artificial neural networks to synthesize feedback laws for homing missiles with non‐linear state equations. We first obtain an open‐loop optimal numerical solution for non‐linear state equations and then use these data to train a feed‐forward multilayer neural network in an off‐line session. The network is then used effectively in a real‐time for feedback guidance method. Simulation results show that this neural networks guidance method can efficiently produce an optimal feedback law in spite of relatively simple network architecture. Copyright © 2000 John Wiley & Sons, Ltd.     

Crocin improved amyloid beta induced long‐term potentiation and memory deficits in the hippocampal CA1 neurons in freely moving rats

Extracellular beta‐amyloid (Aβ) accumulation and deposition is the main factor, which causes synaptic loss and eventually cells death in Alzheimer's disease (AD). Memory loss and long‐term potentiation (LTP) dysfunction in the hippocampus are involved in the AD. The involvement of crocin, as the main and active constituent of saffron extract in learning and memory processes, has been proposed. Here we investigated the probable therapeutic effect of crocin on memory, LTP, and neuronal apoptosis using in vivo Aβ models of the AD. The Aβ peptide (1–42) was bilaterally administered into the frontal‐cortex using stereotaxic apparatus. Five hours after surgery, rats were given intraperitoneal crocin (30 mg/kg) daily, which repeated for 12 days. Barnes maze results showed that administration of crocin significantly improves spatial memory indicators such as latency time to achieving the target hole and the number of errors when compared to Aβ‐group. Passive avoidance test revealed that crocin significantly increased the step‐through‐latency compared to Aβ‐treated alone. These learning deficits in Aβ‐treated animals correlated with a reduction of LTP in hippocampal CA1 synapses in freely moving rats, which crocin improved population spike amplitude and mean field excitatory postsynaptic potentials (fEPSP) slope reduction induced by Aβ. Neuronal apoptosis was detected by TUNEL assay and the expression levels of c‐Fos proteins were examined by Western blotting. Crocin significantly reduced the number of TUNEL‐positive cells in the CA1 region and decreased c‐Fos in the hippocampus compared to Aβ‐group. In vivo Aβ treatment altered significantly the electrophysiological properties of CA1 neurons and crocin further confirmed a neuroprotective action against Aβ toxicity.     

Analysis of brain subnetworks within the context of their whole‐brain networks

Analyzing the structure and function of the brain from a network perspective has increased considerably over the past two decades, with regional subnetwork analyses becoming prominent in the recent literature. However, despite the fact that the brain, as a complex system of interacting subsystems (i.e., subnetworks), cannot be fully understood by analyzing its constituent parts as independent elements, most studies extract subnetworks from the whole and treat them as independent networks. This approach entails neglecting their interactions with other brain regions and precludes identifying potential compensatory mechanisms outside the analyzed subnetwork. In this study, using simulated and empirical data, we show that the analysis of brain subnetworks within the context of their whole‐brain networks, that is, including their interactions with other brain regions, can yield different outcomes when compared to analyzing them as independent networks. We also provide a multivariate mixed‐effects modeling framework that allows analyzing subnetworks within the context of their whole‐brain networks, and show that it can better disentangle global (whole‐brain) and local (subnetwork) differences when compared to standard t‐test analyses. T‐test analyses may produce misleading results in identifying complex global and local level differences. The provided multivariate model is an extension of a previously developed model for global, system‐level hypotheses about the brain. The modified version detailed here provides the same utilities as the original model—quantifying the relationship between phenotypes and brain connectivity, comparing brain networks among groups, predicting brain connectivity from phenotypes, and simulating brain networks—but for local, subnetwork‐level hypotheses.     

Investigating the Frequency of the ERCC1 Gene C8092A Polymorphism in Iranian Patients with Advanced Gastric Cancer Receiving Platinum-based Chemotherapy

Background: Platinum compounds are the main drugs for treatment of advanced gastric cancer. Previous studies have shown that clinical outcome with platinum-based compounds depends on ERCC1 polymorphisms. The aim of this study was to investigate the frequency of a common polymorphism of ERCC1 gene (C8092A) in Iranian patients with advanced gastric cancer receiving platinum chemotherapy. Materials and Methods: Genetic analysis of the ERCC1 C8092A polymorphism was performed by the PCR - RFLP method using 50 paraffin-embedded tissue specimens. Results: Of the 50 cases, 32% of individuals showed CC genotype, 24% of them had CA genotype and 44% of patients had AA genotype. Conclusions: Based on the results, using of platinum-based chemotherapy would be expected to be specifically beneficial in only 32% of patients.     

Tubal gestation and schistosomiasis: a case report

BACKGROUND: Schistosomal infections of the female reproductive tract are common in countries where the parasite is endemic. Serious complications, such as ectopic pregnancy and infertility, may arise in patients with gynecologic schistosomiasis. CASE: A primiparous, African woman presented with vaginal bleeding and was found to have an ectopic pregnancy. Laparoscopy revealed distorted pelvic anatomy due to dense adhesions. Pathologic examination confirmed an ectopic pregnancy and identified Schistosoma haematobium ova in the patient's fallopian tube. Urine examination was confirmatory, and the patient was treated and referred for fertility counseling. CONCLUSION: Clinicians should consider schistosomiasis as a possible etiology for gynecologic complaints, including serious complications such as ectopic pregnancy and infertility, in patients from endemic regions.     

Unconscious orientation processing depends on perceptual load

The effects of perceptual load on the level of adaptation to task-irrelevant and invisible oriented gratings were examined. Participants performed a task at fixation under conditions of low (detecting color targets) or high (detecting conjunctions of color and shape) perceptual load. Simultaneously, a task-irrelevant-oriented grating was presented monocularly in a more peripheral location but was suppressed from awareness by flashing a dynamic mask stimulus at the same retinal location in the other eye. Orientation-specific adaptation to the invisible irrelevant grating was found at low perceptual load but was eliminated with high perceptual load. These results demonstrate that early unconscious processing of orientation depends on the allocation of limited attentional capacity, and conversely that the allocation of attentional capacity under low (versus high) load is insufficient to bring orientation representations to awareness.