An isolated epileptic seizure elicits learning impairment which could be prevented by melatonin

We tested the relation between a single short tonic-clonic seizure elicited by flurothyl vapors and changes of learning in Morris water maze (MWM) in Wistar rats. Oxidative stress usually accompanies seizures. Large melatonin doses were applied immediately before and after seizures to test consequences on learning impairment. One hour of hypobaric hypoxia (8000 m) three days prior to the seizure served as an activator of intrinsic antioxidant systems. Learning in MWM (7 days) started 24 h after seizures. Following seizures, latencies in MWM were longer than in controls and were shortened by hypoxia and preventive melatonin application. Melatonin was also applied before hypoxia to influence free radical (FR) production and intrinsic antioxidant activation. Some behavioral characteristics were changed and preconditioning effect of hypoxia was reduced. Melatonin after seizure (150 s and 6 h) had negligible effect. Results allow us to hypothesize about the role of FR and the beneficial effect of melatonin on the behavioral consequences of seizures.     

Cryoglobulin Composition in Patients with Myocardial Infarction

The formation of an ischemic focus in the myocardium is paralleled by autoimmune processes involving immunoglobulins with abnormal thermal solubility, cryoglobulins. Serum levels of cryoglobulins and their complexes were measured in 25 patients with Q-forming myocardial infarction on days 1, 2, 3, 7, and 14 of the disease. Cryoprotein levels were measured by spectrophotometry, concentrations of IgM, IgA, IgG, and fibronectin by ELISA. Cryocomplexes in patients with myocardial infarction consist of polyclonal immunoglobulins of the main classes IgG and IgM, less often IgA, while cryoglobulinemia in this patient population is referred to type III according to the commonly used classification by Brouet. Fibronectin was detected in the cryocomplexes throughout the entire period of observation, its dynamics being opposite to that of the cryocomplexes level.     

Molecular Characterization of Patient-Derived Human Pancreatic Tumor Xenograft Models for Preclinical and Translational Development of Cancer Therapeutics

Preclinical evaluation of novel cancer agents requires models that accurately reflect the biology and molecular characteristics of human tumors. Molecular profiles of eight pancreatic ductal adenocarcinoma patient tumors were compared to corresponding passages of xenografts obtained by grafting tumor fragments into immunocompromised mice. Molecular characterization was performed by copy number analysis, gene expression and microRNA microarrays, mutation analysis, short tandem repeat (STR) profiling, and immunohistochemistry. Xenografts were found to be highly representative of their respective tumors, with a high degree of genetic stability observed by STR profiling and mutation analysis. Copy number variation (CNV) profiles of early and late xenograft passages were similar, with recurrent losses on chromosomes 1p, 3p, 4q, 6, 8p, 9, 10, 11q, 12p, 15q, 17, 18, 20p, and 21 and gains on 1q, 5p, 8q, 11q, 12q, 13q, 19q, and 20q. Pearson correlations of gene expression profiles of tumors and xenograft passages were above 0.88 for all models. Gene expression patterns between early and late passage xenografts were highly stable for each individual model. Changes observed in xenograft passages largely corresponded to human stromal compartment genes and inflammatory processes. While some differences exist between the primary tumors and corresponding xenografts, the molecular profiles remain stable after extensive passaging. Evidence for stability in molecular characteristics after several rounds of passaging lends confidence to clinical relevance and allows for expansion of models to generate the requisite number of animals required for cohorts used in drug screening and development studies.     

Long-term urban particulate air pollution, traffic noise, and arterial blood pressure

Background: Recent studies have shown an association of short-term exposure to fine particulate matter (PM) with transient increases in blood pressure (BP), but it is unclear whether long-term exposure has an effect on arterial BP and hypertension.Objectives: We investigated the cross-sectional association of residential long-term PM exposure with arterial BP and hypertension, taking short-term variations of PM and long-term road traffic noise exposure into account.Methods: We used baseline data (2000–2003) on 4,291 participants, 45–75 years of age, from the Heinz Nixdorf Recall Study, a population-based prospective cohort in Germany. Urban background exposure to PM with aerodynamic diameter ≤ 2.5 μm (PM_2.5) and ≤ 10 μm (PM₁₀) was assessed with a dispersion and chemistry transport model. We used generalized additive models, adjusting for short-term PM, meteorology, traffic proximity, and individual risk factors.Results: An interquartile increase in PM_2.5 (2.4 μg/m³) was associated with estimated increases in mean systolic and diastolic BP of 1.4 mmHg [95% confidence interval (CI): 0.5, 2.3] and 0.9 mmHg (95% CI: 0.4, 1.4), respectively. The observed relationship was independent of long-term exposure to road traffic noise and robust to the inclusion of many potential confounders. Residential proximity to high traffic and traffic noise exposure showed a tendency toward higher BP and an elevated prevalence of hypertension.Conclusions: We found an association of long-term exposure to PM with increased arterial BP in a population-based sample. This finding supports our hypothesis that long-term PM exposure may promote atherosclerosis, with air-pollution–induced increases in BP being one possible biological pathway.     

A Drosophila heat shock response represents an exception rather than a rule amongst Diptera species

Heat shock protein 70 (Hsp70) is the major player that underlies adaptive response to hyperthermia in all organisms studied to date. We investigated patterns of Hsp70 expression in larvae of dipteran species collected from natural populations of species belonging to four families from different evolutionary lineages of the order Diptera: Stratiomyidae, Tabanidae, Chironomidae and Ceratopogonidae. All investigated species showed a Hsp70 expression pattern that was different from the pattern in Drosophila. In contrast to Drosophila, all of the species in the families studied were characterized by high constitutive levels of Hsp70, which was more stable than that in Drosophila. When Stratiomyidae Hsp70 proteins were expressed in Drosophila cells, they became as short‐lived as the endogenous Hsp70. Interestingly, three species of Ceratopogonidae and a cold‐water species of Chironomidae exhibited high constitutive levels of Hsp70 mRNA and high basal levels of Hsp70. Furthermore, two species of Tabanidae were characterized by significant constitutive levels of Hsp70 and highly stable Hsp70 mRNA. In most cases, heat‐resistant species were characterized by a higher basal level of Hsp70 than more thermosensitive species. These data suggest that different trends were realized during the evolution of the molecular mechanisms underlying the regulation of the responses of Hsp70 genes to temperature fluctuations in the studied families.     

Color perception following intensive photic stimulation]

After a monocular effect of a short-term intensive light stimulation (of 80 mksec in duration with illuminance of 1600 cdl. sec) which followed complete dark adaptation, test subjects showed disorders in color perception. They included lowered decrease in the acuity of color discrimination measured in the AN-59 anomaloscope and significant distortion of the subjective evaluation of different color stimuli. The spectrum of an experimental intensive light effect was varied; it was thus shown that disorders in the color perception were associated with a nonuniform decrease of the sensitivity of color perceiving systems of the optic analyzer. The pattern and duration of these disturbances depended on the spectral composition and intensity of the light stimulus.