Insoluble Vascular Amyloid Deposits Trigger Disruption of the Neurovascular Unit in Alzheimer’s Disease Brains

Alzheimer’s disease (AD) is a neurodegenerative disease, characterized histopathologically by intra-neuronal tau-related lesions and by the accumulation of amyloid β-peptide (Aβ) in the brain parenchyma and around cerebral blood vessels. According to the vascular hypothesis of AD, an alteration in the neurovascular unit (NVU) could lead to Aβ vascular accumulation and promote neuronal dysfunction, accelerating neurodegeneration and dementia. To date, the effects of insoluble vascular Aβ deposits on the NVU and the blood–brain barrier (BBB) are unknown. In this study, we analyze different Aβ species and their association with the cells that make up the NVU. We evaluated post-mortem AD brain tissue. Multiple immunofluorescence assays were performed against different species of Aβ and the main elements that constitute the NVU. Our results showed that there are insoluble vascular deposits of both full-length and truncated Aβ species. Besides, insoluble aggregates are associated with a decrease in the phenotype of the cellular components that constitute the NVU and with BBB disruption. This approach could help identify new therapeutic targets against key molecules and receptors in the NVU that can prevent the accumulation of vascular fibrillar Aβ in AD.     

Response of the hypothalamic neurons to stimulation of the vestibular nerve and lateral vestibular nucleus in rabbits

Effects of single, double, and rhythmic stimulation upon hypothalamic neurons responding to the 1st excitatory phase of lateral vestibular nucleus stimulation, were studied. The data obtained show that activation of some hypothalamic neurons following stimulation of the lateral vestibular nucleus has a monosynaptic character. The findings suggest that ascending afferents from the lateral vestibular nucleus to the hypothalamus pass via oligo- as well as polysynaptic pathways.     

The effect of spermine on protein kinase activity and number of cytosolic estradiol receptors

Spermine decreased distinctly the activity of Ca2+ -phospholipid-dependent protein kinases, whereas not affected the protein kinase A activity. Content of cytosol estradiol receptors was drastically decreased in rat uterine in presence of the polyamine. The data obtained and literature data suggest that activation of estradiol receptors appears to occur after phosphorylation by means of Ca2+ - dependent protein kinases, which are regulated via phosphoinositide-involving mechanism, i.e. these receptors acquire the ability to bind hormones.     

Closed-chest cardiopulmonary bypass and cardioplegia: basis for less invasive cardiac surgery

BACKGROUND: We developed a method of closed-chest cardiopulmonary bypass to arrest and protect the heart with cardioplegic solution. This method was used in 54 dogs and the results were retrospectively analyzed. METHODS: Bypass cannulas were placed in the right femoral vessels. A balloon occlusion catheter was passed via the left femoral artery and positioned in the ascending aorta. A pulmonary artery vent was placed via the jugular vein. In 17 of the dogs retrograde cardioplegia was provided with a percutaneous coronary sinus catheter. RESULTS: Cardiopulmonary bypass time was 111 +/- 27 minutes (mean +/- standard deviation) and cardiac arrest time was 66 +/- 21 minutes. Preoperative cardiac outputs were 2.9 +/- 0.70 L/min and postoperative outputs were 2.9 +/- 0.65 L/min (p = not significant). Twenty-one-French and 23F femoral arterial cannulas that allowed coaxial placement of the ascending aortic balloon catheter were tested in 3 male calves. Line pressures were higher, but not clinically limiting, with the balloon catheter placed coaxially. CONCLUSIONS: Adequate cardiopulmonary bypass and cardioplegia can be achieved in the dog without opening the chest, facilitating less invasive cardiac operations. A human clinical trial is in progress.     

Combined pathology of the pancreas and myocardium in myocardial infarction and acute destructive pancreatitis

Pancreas was studied in 30 patients who died of myocardial infarction (MI). Total pancreonecrosis was found in 1 case (recurring MI), diffuse focal pancreonecrosis in 3 cases (the second MI). Local microcirculation disturbances, thrombosis of some interlobular veins, degenerative changes of the exocrine pancreocytes with translocation of zymogen granules and their parapedesis into the edematous interstitium were found in all other cases. Focal metabolic myocardial damage and circulation disturbances mainly in the subendocardium of the left ventricle myocardium were found in the heart of 3 patients who died of pancreonecrosis and 60 white rats with pancreatitis induced by chloroethyl. There was a redistribution of Ca2+ in the ultrastructural components of the cardiomyocytes with its accumulation in the cytosol and sarcoplasmic reticulum. The most pronounced and widespread myocardial damage was observed in the hemorrhagic stage of pancreatitis.     

Radiation in systems with near zero dielectric constant

We discuss radiation effects in systems with near zero dielectric constant. An enhancement of intensity using the example of transition and diffusive radiation is demonstrated. A sharp peak in the transition radiation spectral-angular intensity is predicted. Numerical estimates for specific systems are made and possible applications are discussed.     

GABA reuptake by rat brain slices in hypokinesia and under the influence of cinnarizine and flunarizine

The paper outlines a package of programmes for computer-aided processing of electrocardiograms in children and adolescents, for determination of amplitude-time responses of cardiographic complexes, waves, and intervals and for syndrome conclusion in terms of clinical electrocardiography. The package has been prepared in Turbo-Pascal and Assembler languages.     

Serologic reactivity of a synthetic peptide from human immunodeficiency virus type 1 gp41 with sera from a Mexican population

The reactivities of 1,172 serum samples obtained from asymptomatic human immunodeficiency virus type 1 (HIV-1)-positive and HIV-1-negative individuals residing in Mexico to a synthetic disulfide-looped peptide from the HIV-1 gp41 (amino acids 602 to 616 [IWGCSGKLICTTAVP] were examined by an enzyme-linked immunoadsorbent assay (ELISA) procedure. Antibodies to the synthetic peptide were detected in 261 of 268 serum samples from HIV-positive individuals (sensitivity, 97.4%). The peptide also reacted with 12 of 904 serum samples from control HIV-negative individuals (specificity, 98.7%). Western blots (immunoblots) of four of the seven serum samples that produced false-negative results in the ELISA showed that three of them reacted weakly with gp41 and strongly with gp120, p55, and/or p24. Potential diagnostic difficulties raised by the reported C1q binding capacity of this peptide were also evaluated: few and weak false-positive results were found among sera from patients with rheumatoid arthritis (1 of 31) and neurocysticercosis (2 of 111). In fact, strong reactivity with the peptide spotted an undetected HIV infection underlying clinical neurocysticercosis.