Chronic Benzene Exposure Aggravates Pressure Overload-Induced Cardiac Dysfunction

Benzene is a ubiquitous environmental pollutant abundant in household products, petrochemicals, and cigarette smoke. Benzene is a well-known carcinogen in humans and experimental animals; however, little is known about the cardiovascular toxicity of benzene. Recent population-based studies indicate that benzene exposure is associated with an increased risk for heart failure. Nonetheless, it is unclear whether benzene exposure is sufficient to induce and/or exacerbate heart failure. We examined the effects of benzene (50 ppm, 6 h/day, 5 days/week, and 6 weeks) or high-efficiency particulate absorbing-filtered air exposure on transverse aortic constriction (TAC)-induced pressure overload in male C57BL/6J mice. Our data show that benzene exposure had no effect on cardiac function in the Sham group; however, it significantly compromised cardiac function as depicted by a significant decrease in fractional shortening and ejection fraction, as compared with TAC/Air-exposed mice. RNA-seq analysis of the cardiac tissue from the TAC/benzene-exposed mice showed a significant increase in several genes associated with adhesion molecules, cell-cell adhesion, inflammation, and stress response. In particular, neutrophils were implicated in our unbiased analyses. Indeed, immunofluorescence studies showed that TAC/benzene exposure promotes infiltration of CD11b(+)/S100A8(+)/myeloperoxidase(+)-positive neutrophils in the hearts by 3-fold. In vitro, the benzene metabolites, hydroquinone, and catechol, induced the expression of P-selectin in cardiac microvascular endothelial cells by 5-fold and increased the adhesion of neutrophils to these endothelial cells by 1.5- to 2.0-fold. Benzene metabolite-induced adhesion of neutrophils to the endothelial cells was attenuated by anti-P-selectin antibody. Together, these data suggest that benzene exacerbates heart failure by promoting endothelial activation and neutrophil recruitment

ВИКОРИСТАННЯ СИСТЕМИ КОНТРОЛЮ СТАНУ СТРІЛОЧНИХ ДВИГУНІВ ПО КРИВІЙ СПОЖИВАННЯ СТРУМУ В РЕМОНТНО-ТЕХНІЧНИХ ДІЛЬНИЦЯХ

The analysis of existing method of verification of pointer engines of direct current with the successive excitation in the repair-technical areas has been conducted, the automated device for the exposure of refusals in the electric engines on the curves of consumption of current in the conditions of repair-technical areas at the periodic examination has been offered.Проведен анализ существующей методики проверки в ремонтно-технических участках стрелочных двигателей постоянного тока с последовательным возбуждением, предложено автоматизированное устройство для выявления отказов в электрических двигателях по кривым потребления тока в условиях ремонтнотехнических участков при периодическом осмотре.Проведено аналіз існуючої методики перевірки в ремонтно-технічних дільницях стрілочних двигунів постійного струму з послідовним збудженням, запропоновано автоматизований пристрій для виявлення відмов електричних двигунів по кривих споживання струму в умовах ремонтно-технічної дільниці при періодичному огляді

Medulloblastomas of the Cerebellum in Children: Clinicopathologic Comparison

Abstract Embryonal neuroepithelial tumours of the brain, grade IV are mainly observed in children and are characterized by rapid metastatic spread and frequent recurrence. The aim of the work is to compare structural features of medulloblastomas of the cerebellum in children of different age groups taking into account localization, metastatic spread and treatment outcomes. Materials and methods. The results of complete examination and surgical treatment of 289 children with medulloblastoma of the cerebellum at the Department of Pediatric Neurosurgery of Institute of neurosurgery named after A.P. Romodanov over the period of 1993–2013 were analysed. The children’s age ranged from 1 month to 17 years: peak of medulloblastoma detection was registered at the age of 4–7. Results. As part of the study all the patients were divided into four age groups. Younger children rarely had brainstem lesion. In children of older age brainstem lesion, invasion into cerebral aqueduct with the development of noncommunicating hydrocephalus were registered. Total resection of medulloblastoma in younger children was performed in 40 % of cases, subtotal – in 42 %, partial – in 18 %. In children of older age total resection of medulloblastoma was carried out in 36%, subtotal – in 52 %, partial – in 12 % of cases. Histological analysis of tumours involved morphological characteristics of general histoarchitecture, correlation between parenchymal and stromal component, presence of Homer Wright pseudorosettes, collonar structures, pale insulas, true ependymal rosettes, formation of braided collonar structures, prevalence of small low-differentiated structures, number of mitoses, neoangiogenesis and angioproliferation, presence of colliquative and coagulation necroses, evidence and type of invasion, lymphocytic infiltration of tumour tissue. The following variations were defined histologically: classical – 9470/3 in 34 cases (17.9 %), desmoplastic/nodular – 9471/3 in 17 cases (8.9 %), with extensive nodularity – 9471/3 in 59 cases (31.2 %), large-cell (anaplastic) – 9474/3 in 51 cases (26.9 %), does not belong to any of the above (transitional/combined) – 9470/3 in 28 cases (15.1 %). Conclusions. It was established that survival index after total and subtotal tumour resection was not significantly different; a negative prognostic factor was only a partial removal of the tumour

Humidity-enhanced sub-ppm sensitivity to ammonia of covalently functionalized single-wall carbon nanotube bundle layers

A low-cost method for carbon nanotubes (CNTs) network production from solutions on flexible polyethylene naphthalate substrates has been adopted to prepare high quality and well characterized SWCNT bundle layers to be used as the active layer in chemiresistor gas sensors. Two types of SWCNTs have been tested: pristine SWCNTs, deposited from a surfactant solution, and covalently functionalized SWCNTs, deposited from a dimethyl-acetamide solution. The humidity effects on the sensitivity of the SWCNTs network to NH 3 have been investigated. The results show that relative humidity favors the response to NH 3 , confirming recent theoretical predictions. The COOH-functionalized sample displays the largest response owing to both its hydrophilic nature, favoring the interaction with H 2 O molecules, and its largest surface area. Compared to data available in the literature, the present sensors display a remarkable sensitivity well below the ppm range, which makes them quite promising for environmental and medical applications, where NH 3 concentrations (mostly of the order of tens of ppb) have to be detected