Arsenic is an environmental toxicant known to be a carcinogen and endocrine disruptor. Maternal exposure to arsenic has been associated with fetus malformation and reproductive disorders in male ...offspring. However, it is unclear the extent to which those effects remain during postnatal development and adulthood. Therefore, this study aimed to investigate the long‐term effects of prenatal arsenic exposure on reproductive parameters of male offspring at peripubertal and adult periods. Pregnant female Wistar rats were exposed to 0 or 10 mg/L sodium arsenite in drinking water from gestational day 1 (GD 1) until GD 21 and male pups were analyzed at postnatal day 44 (PND 44) and PND 70. We observed that some reproductive parameters were affected differently by arsenic exposure at each age evaluated. The body and reproductive organs weights, as well as testicular and epididymal morphology were strongly affected in peripubertal animals and recovered at adult period. On the other hand, the antioxidant genes expression (SOD1, SOD2, CAT and GSTK1) and the endogenous antioxidant system were affected in the testes and epididymides from both peripubertal and adult rats. Finally, an impairment in daily sperm production and in sperm parameters was observed in adult animals. Taken together, our findings show that prenatal arsenic exposure affected reproductive parameters of peripubertal and adult male rats mainly due to oxidative stress. Collectively, those alterations may be affecting fertility potential of adult animals.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
2.
Arsenic exposure intensifies glycogen nephrosis in diabetic rats Sertorio, Marcela Nascimento; Souza, Ana Cláudia Ferreira; Bastos, Daniel Silva Sena ...
Environmental science and pollution research international,
04/2019, Volume:
26, Issue:
12
Journal Article
Peer reviewed
It is known that either arsenic exposure or diabetes can impact renal function. However, it is unclear how these combined factors may influence kidney functions. Therefore, we evaluated ...morphological, functional, and oxidative parameters in the kidney of diabetic rats exposed to arsenic. Healthy male Wistar rats and streptozotocin-induced diabetic rats were exposed to 0 and 10 mg/L arsenate through drinking water for 40 days. Renal tissue was assessed using morphometry, mitosis and apoptosis markers, mineral proportion, oxidative stress markers, as well as the activity of antioxidant enzymes and membrane-bound adenosine triphosphatases. Arsenate intake altered glucose levels in healthy animals, but it did not reach hyperglycemic conditions. In diabetic animals, arsenate led to a remarkable increase of glycogen nephrosis in distal tubules. In these animals, additionally, the activity of catalase and glutathione
S
-transferase, besides the proportion of Fe, Cu, and K in renal tissue, was altered. Nevertheless, arsenate did not accumulate in the kidney and did not impact on other parameters previously altered by diabetes, including levels of malondialdehyde, Na, urea, creatinine, and apoptosis and mitosis markers. In conclusion, besides the intensification of glycogen nephrosis, the kidney was able to handle arsenate toxicity at this point, preventing arsenic deposition in the exposed groups and the impairment of renal function.
Purpose--To analyze the configurations of legitimacy, dynamic capabilities, and business resources consistent with the survival of post-incubated companies. Theoretical framework--"Liability of ...newness" highlights that nascent companies suffer from factors that hinder their survival. However, business incubators help to develop nascent businesses. This paper seeks to show how different configurations between legitimacy, dynamic capabilities, and resources can form a strategic orientation for survival. Design/methodology/approach--The strategy of multiple case studies was applied to 90 companies and the techniques of fuzzy set qualitative comparative analysis (fsQCA) were used. Findings--The results present two configurations of technology-based companies with high perceptions of legitimacy, resources, and dynamic capabilities that differ by size and satisfaction. A third configuration of technology-based companies has high perceptions of legitimacy and resources. A fourth configuration involves technology-based companies with high perceptions of legitimacy, a larger size, and satisfaction with the incubator. Practical & social implications of research--For managers, the results make it possible to create an incubation environment that is able to identify and fill the individual gaps of the enterprises. In addition, they indicate that business incubator managers and/or funders should focus their efforts on the incubation of technology-based companies. Originality/value--The first is to reinforce the central role of legitimacy for survival. The second is to show that the interrelationship between legitimacy, resources, and dynamic capabilities forms resilient organizational configurations in different ways. Keywords: Liability of newness, enterprise configuration, post-incubation, organizational survival, fsQCA.
Reproductive seasonality in Neotropical bats has been assessed to the better understand their reproductive behavior. This knowledge is especially important for the control of Desmodus rotundus ...population as it is a transmitter of rabies virus. Therefore, we aimed to evaluate the functional activity of testis and epididymis of D. rotundus in dry and rainy seasons under a morphological approach. We observed an increase in tubular diameter and epithelial height of the seminiferous tubules during the rainy season. In the latter, additionally, stereological analysis of the testis showed increased proportion of seminiferous epithelium and reduced percentage of lumen. The sperm number in caput/corpus epididymis increased in rainy season, whereas sperm count and transit time were reduced in cauda region. These alterations were probably related to the recovery of epithelium activities after mating season in dry season. Despite altered nuclear and cytoplasm parameters of Leydig cells between seasons, the volume and number of these cells were constant. Moreover, no change in serum testosterone levels, daily sperm production, and apoptotic index were observed, which indicates that the reproductive pattern in D. rotundus does not change between seasons. Our study offers a baseline for the management of vampire bat population as an attempt to control rabies disease.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Objective The aim of this study was to evaluate perceptions regarding esthetic appearance of the smile in cases of orthognathic surgery for correction of maxillary gingival display. Study Design ...Alterations were made to an extraoral front-view photograph of a gingival smile in normal occlusion by repositioning the maxilla to simulate bone tissue removal and gingival exposure. Images were printed on photographic paper attached to questionnaires distributed among laypersons, professionals, and dental students to evaluate degree of esthetics (n = 150). To evaluate degree of esthetics, an attractiveness-scale was used, with 0 representing hardly attractive, 5 attractive, and 10 very attractive. Results All of the evaluated groups demonstrated that large gingival extension does not always affect esthetic appearance of the smile. Insufficiently visualized maxillary incisors were considered hardly attractive and received statistically lower scores ( P < .05). Conclusions According to esthetic parameters, gingiva play important roles in composition of the smile, but only when they are exposed to a small extent.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Arsenic is a pollutant widely found in the environment due to natural and anthropogenic sources. Exposure to arsenic forms in drinking water has been related with male reproductive dysfunctions in ...humans and experimental animals at adult age. However, the impact of this pollutant on postnatal reproductive development of male offspring exposed in utero to arsenic is still unknown. Therefore, this study aimed to investigate the effects of prenatal arsenic exposure on the postnatal development of the testes and epididymides of rats, during prepuberty. For this purpose, pregnant female Wistar rats were provided drinking water containing 0 or 10 mg/L sodium arsenite (AsNaO2) from gestational day 1 (GD 1) until GD 21 and the male offspring was evaluated in different periods of prepuberty. Our results showed that prenatal arsenic exposure affected the initial sexual development of male pups, reducing their body weight and relative anogenital distance at postnatal day 1. At different periods of prepuberty, male pups from arsenic exposed dams showed a reduction of body and reproductive organs weights, testosterone levels and testis morphometric parameters. Moreover, these pups presented changes in the expression of SOD1, SOD2, CAT and GSTK1 genes and in the activity of superoxide dismutase, catalase and glutathione s-transferase in the testes and epididymides during prepuberty. Taken together, our results show that prenatal arsenic exposure provoked reproductive disorders in prepubertal male rats, probably due to reproductive reprograming and oxidative stress induced by this pollutant.
•Prenatal arsenic exposure affected rat male reproductive development.•Gestational exposure to arsenic caused reproductive reprogramming in male rats.•Testis and epididymis of prepubertal rats are damaged by prenatal arsenic exposure.•Prenatal arsenic exposure disturbed antioxidant genes and enzymes in male pups.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The main source of environmental arsenic exposure in most countries of the world is drinking water in which inorganic forms of arsenic predominate. The present study was aimed to test the impact of ...two different compounds of inorganic arsenic in histomorphometric and enzymatic parameters in the testes by oral exposition. Adult Wistar male rats were exposed to sodium arsenite and arsenate in drinking water, testing for each chemical form the concentrations of 0.01 and 10Â mg/L per 56Â days. The animals intoxicated with arsenic, mainly sodium arsenite, showed reduction in the percentage of seminiferous epithelium and in proportion and volume of Leydig cells. Moreover, there was an increase in the percentage of tunica propria, lumen, lymphatic space, blood vessels, and macrophages. The activity of superoxide dismutase (SOD) did not change among the groups. However, the activity of catalase (CAT) decreased in animals exposed to both arsenic compounds. In addition, the higher concentration of arsenic, mainly as sodium arsenite, caused vacuolization in the seminiferous epithelium. The body and testes weight as well as testosterone concentration remained unchanged among the groups. In conclusion, exposition to arsenic, mainly as sodium arsenite, caused alteration in histomorphometric parameters and antioxidant defense system in the testes.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
•Epithelium height decreased along the duct from caput to cauda regions.•Principal cells are the most abundant cell type, mainly in the epididymis cauda.•The relative frequency of basal and clear ...cells did not change along the duct.•PAS-positive labeling in cytoplasmic granules and stereocilia of principal cells.•Goblet-shaped clear cell showed apical mitochondria and electron-lucid vesicles.
The blood-feeding behavior of Desmodus rotundus made this bat a potential vector of rabies virus and a public health issue. Consequently, the better understanding of its reproductive biology becomes valuable for the development of methods to control its population. In this study, we described morphological aspects of epithelial cells in D. rotundus’ epididymis using light and transmission electron microscopy methods. The duct compartment was the main component of initial segment (83%), caput (90%), corpus (88%) and cauda (80%) regions. The epithelium lining the duct presented a progressive decrease in its height from initial segment to cauda regions. Moreover, the morphology of each cell type was the same along the entire duct. Similarly to rodents, columnar-shaped principal cells were the most abundant cell type throughout the epididymis, followed by basal and clear cells. Differently in rat and mice, the frequency of clear cells did not increase in the epididymis cauda, whereas the proportion of principal and basal cells was greater in this region. Furthermore, D. rotundus presented goblet-shaped clear cells with the nucleus located in the apical portion of the epididymal epithelium. This cellular portion also presented electron-lucid vesicles of different sizes that may correspond to vesicles enriched with proteins related to proton secretion. In addition to the findings regarding clear cells’ structural organization, basal cells presented scarce cytoplasm and no axiopodia. Taken these findings together, we suggest that the mechanism of luminal acidification may have other pathways in D. rotundus than those described in rodents.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Soil nitrogen dynamics in terrestrial ecosystems can be evaluated by analyzing the natural abundances of N isotope ratio mass spectrometry (δ15N) because δ15N integrates decades of organic matter ...transformations in the soil. On a large scale, the δ15N of soil organic matter across climate gradients may provide critical insights into understanding regional patterns of N cycling. However, the mechanisms that control N cycling in some tropical regions still present critical gaps, particularly in dry ecosystems. We evaluated the variation of soil δ15N in Alisols along the climatic gradient of three physiographic regions in Northeast Brazil: Zona da Mata (humid, rainfall well distributed throughout the year), Agreste (subhumid, rainfall concentrated in 5–7 months), and Sertão (semiarid, rainfall in highly intense events, concentrated over 3–5 months). Soil samples were collected at the 0–20 cm depth layer and analyzed for physical and chemical characteristics, including soil δ15N, by mass spectrometry. A linear model with physical biological, chemical, and climatic variables was generated to explain the spatial distribution of the soil δ15N. The map modeled values δ15N for Pernambuco State was produced using all observed values and the best-performing explicit spatial predictive variables in the model selection – pH, clay content, mean temperature, mean precipitation, and potential of evapotranspiration. Soil δ15N was positively related to clay content and negatively associated with the pH, temperature, rain, and evapotranspiration, expressing differences in nitrogen dynamics along the climatic gradient. In the Sertão, the low and erratic rainfall combined with a neutral pH and high temperature provide adequate conditions for nitrogen transformations and cause high soil δ15N.
Display omitted
•Soil δ15N decreases with the increase of temperature in Brazilian semi-arid.•Soil δ15N increases with the increase of evapotranspiration in Brazilian semi-arid.•Frequency and intensity of rainfall affect the dynamics of N in the soil.•Climate is the principal driver of soil δ15N in Pernambuco state, northeast Brazil.•Clay content is an important factor for the stability of nitrogen in the soil.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
To evaluate the degree of perception of laypersons, dental professionals, and dental students regarding dental esthetics in cases with mandibular central incisor extraction.
Using a smile photograph ...of a person with normal occlusion and all teeth, modifications were made to reflect the extraction of a mandibular incisor of various compositions and sizes. For this purpose a program specifically for image manipulation (Adobe Photoshop CS3, Adobe Systems Inc) was used. After manipulation the images were printed on photographic paper, attached to a questionnaire and distributed to laypersons, dental professionals, and dental students (n = 90) to evaluate the degree of perception and esthetic using a scale of attractiveness, where 0 = hardly attractive, 5 = attractive, and 10 = very attractive. The differences between examiners were checked by the Mann-Whitney test. All the statistics were performed with a confidence level of 95%.
The results demonstrated the skill of the dental professionals and dental students in perceiving the difference between cases of normal occlusion and cases where an incisor was lacking (P < .05). The photograph in which the lateral incisors were shown to be larger than the central incisor was the one that obtained the highest value among the cases of extraction in all groups of evaluators.
It can be concluded that dental professionals and dental students are more skillful at identifying deviation from normality. In addition, central incisor extraction should always be discarded when there are other treatment options available.
PDF
