Response to Comments of Peter G. Mantle

The apparently high yield of testis tumors (25%) in rats exposed long-term to Ochratoxin A (OTA) is uninterpretable without data on tumor yield in unexposed rats. Conversely, our demonstration that prenatal exposure to OTA induces DNA adducts in the testes of newborn mice and the absence of these adducts in the testes of mice not exposed prenatally to OTA, is evidence for the presumptive carcinogenicity of OTA in the testis. Together with recent data showing that prenatal exposure to OTA depresses expression of DMRT1, a tumor suppressor gene in the testis, our findings suggest that OTA may be a cause of testicular cancer

Formation of Actin Networks in Microfluidic Concentration Gradients

The physical properties of cytoskeletal networks are contributors in a number of mechanical responses of cells, including cellular deformation and locomotion, and are crucial for the proper action of living cells. Local chemical gradients modulate cytoskeletal functionality including the interactions of the cytoskeleton with other cellular components. Actin is a major constituent of the cytoskeleton. Introducing a microfluidic-based platform, we explored the impact of concentration gradients on the formation and structural properties of actin networks. Microfluidic-controlled flow-free and steady-state experimental conditions allow for the generation of chemical gradients of different profiles, such as linear or step-like. We discovered specific features of actin networks emerging in defined gradients. In particular, we analyzed the effects of spatial conditions on network properties, bending rigidities of network links, and the network elasticity

Mutagenicity of Ochratoxin A and Its Hydroquinone Metabolite in the SupF Gene of the Mutation Reporter Plasmid Ps189

Ochratoxin A (OTA) is a mycotoxin that enhances renal tumor formation in the outer medulla of male rat kidney. Direct DNA damage and subsequent mutagenicity may contribute to these processes. In this study we have determined whether OTA in the absence or presence of activated rat liver microsomes (RLM) or redox-active transition metals (Fe(III) or Cu(II)) causes promutagenic DNA damage in the supF gene of the mutation reporter plasmid pS189 replicating in human Ad293 cells. In addition, we have assessed the mutagenicity of the hydroquinone metabolite (OTHQ) of OTA in the absence or presence of cysteine without added cofactors. Our results show that oxidation of OTA, either by RLM or by transition metal ions, activates OTA to a directly genotoxic mutagen(s). The Fe(III)/OTA system was the most potent mutagen in our experimental system, causing a 32-fold increase in mutant fraction (MF) above the spontaneous control MF. The Cu(II)/OTA system caused a 9-fold increase in MF, while a 6–10-fold increase in MF was observed for OTA in the presence of RLM. The OTHQ metabolite is also mutagenic, especially in the presence of cysteine, in which a 6-fold increase in MF was observed. Our data provide further insight into OTA bioactivation that may account for its in vivo mutagenicity in male rat kidney

Роль сечової кислоти в механізмах кардіоінотропних ефектів бальнеотерапевтичного комплексу курорту Трускавець

В русле концепции оо эндогенной мочевой кислоте как одном из звеньев механизма действия биоактивной воды Нафтуся на функциональные системы организма проанализированы совместные изменения под влиянием бальнеотерапии на курорте Трускавець уровня урикемии и сократительной активности миокарда. Выявлены три типа детерминации урикемией инотропии: ураторто-, уратинверс- и уратнезависимый типы, реализация которых обуславливается констелляцией 22 исходных параметров вегетативной регуляции, велоэргометрии, электролитного и липидного обменов, гемодинамики, а также антропометрии.It is detected three types determination of inotropy by plasma level of uric acid: uratorthodependent, uratinversdependent and uratindependent types. It is selected constellation of initial parameters of vegetative regulation, veloergometry, haemodynamic, antropometry, electrolythic and lipid exchange conditionizes these types

A doença de Chagas e o açaí: considerações sobre a situação no Amapá.

A doença de Chagas é causada pelo protozoário Trypanosoma cruzi, que pode ser transmitido por insetos popularmente chamados de ?barbeiros? contaminados. Na região Norte do Brasil, houve um aumento gradativo dos casos dessa doença, relacionando-a à ingestão da bebida processada de frutos de açaizeiro, consumida como refeição diária pela população. O barbeiro contaminado pode estar presente no fruto, durante a colheita, transporte, comercialização e no processamento em bebida nos estabelecimentos conhecidos como ?batedeiras?. O objetivo deste trabalho foi realizar análise temporal dos casos de doença de Chagas no Amapá no período de 2007 a 2018.bitstream/item/218793/1/CPAF-AP-2020-A-doenca-de-Chagas-e-o-acai.pd

Natural occurrence of ochratoxin A contamination in commercial black and white pepper products.

The concentration of ochratoxin A (OTA) in 120 commercial pepper (84 pre-packed and 36 bulk samples), which consist of local and imported white and black pepper in powder and seed form in Malaysia were determined. The objective of the study was to investigate and compare OTA concentration in black pepper and white pepper being commercialized in Malaysia. Determination method was based on HPLC with fluorescence detection coupled with immunoaffinity column clean-up step. Mobile phase consisted of acetonitrile-water-acetic acid (49.5:49.5:1.0, v/v/v), and flow rate was 1 ml/min. The LOD was 0.02 ng/g, and the average recovery values of OTA ranged from 79.5 to 92.0% in black pepper and 81.2-90.3% in white pepper. A total of 57 samples (47.5%) were contaminated with OTA ranging from 0.15 to 13.58 ng/g. The results showed that there was a significant difference between type of pepper and brands. OTA concentration in black pepper was significantly higher than white pepper (p < 0.05). The highest concentration of ochratoxin, 13.58 ng/g, was detected in a sample of black pepper seed followed by 12.64 ng/g in a sample of black pepper powder, both were bulk samples purchased from open market

Stiff polymer in monomer ensemble

We make use of the previously developed formalism for a monomer ensemble and include angular dependence of the segments of the polymer chains thus described. In particular we show how to deal with stiffness when the polymer chain is confined to certain regions. We investigate the stiffness from the perspectives of a differential equation, integral equations, or recursive relations for both continuum and lattice models. Exact analytical solutions are presented for two cases, whereas numerical results are shown for a third case.Comment: 10 pages, including 6 figure