Ventilation-induced changes correlate to pulmonary vascular response and VEGF, VEGFR-1/2, and eNOS expression in the rat model of postnatal hypoxia.

Neonatal asphyxia occurs due to reduction in oxygen supply to vital organs in the newborn. Rapid restoration of oxygen to the lungs after a long period of asphyxia can cause lung injury and decline of respiratory function, which result from the activity of molecules that induce vascular changes in the lung such as nitric oxide (NO) and vascular endothelial growth factors (VEGF). In this study, we evaluated the pulmonary and vascular morphometry of rats submitted to the model of neonatal asphyxia and mechanical ventilation, their expression of pulmonary VEGF, VEGF receptors (VEGFR-1/VEGFR-2), and endothelial NO synthase (eNOS). Neonate Sprague-Dawley rats (CEUA #043/2011) were divided into four groups (n=8 each): control (C), control submitted to ventilation (CV), hypoxia (H), and hypoxia submitted to ventilation (HV). The fetuses were harvested at 21.5 days of gestation. The morphometric variables measured were body weight (BW), total lung weight (TLW), left lung weight (LLW), and TLW/BW ratio. Pulmonary vascular measurements, VEGFR-1, VEGFR-2, VEGF, and eNOS immunohistochemistry were performed. The morphometric analysis showed decreased TLW and TLW/BW ratio in HV compared to C and H (P<0.005). Immunohistochemistry showed increased VEGFR-2/VEGF and decreased VEGFR-1 expression in H (P<0.05) and lower eNOS expression in H and HV. Median wall thickness was increased in H, and the expression of VEGFR-1, VEGFR-2, VEGF, and eNOS was altered, especially in neonates undergoing H and HV. These data suggested the occurrence of arteriolar wall changes mediated by NO and VEGF signaling in neonatal hypoxia.

Ventilation-induced changes correlate to pulmonary vascular response and VEGF, VEGFR-1/2, and eNOS expression in the rat model of postnatal hypoxia

Neonatal asphyxia occurs due to reduction in oxygen supply to vital organs in the newborn. Rapid restoration of oxygen to the lungs after a long period of asphyxia can cause lung injury and decline of respiratory function, which result from the activity of molecules that induce vascular changes in the lung such as nitric oxide (NO) and vascular endothelial growth factors (VEGF). In this study, we evaluated the pulmonary and vascular morphometry of rats submitted to the model of neonatal asphyxia and mechanical ventilation, their expression of pulmonary VEGF, VEGF receptors (VEGFR-1/VEGFR-2), and endothelial NO synthase (eNOS). Neonate Sprague-Dawley rats (CEUA #043/2011) were divided into four groups (n=8 each): control (C), control submitted to ventilation (CV), hypoxia (H), and hypoxia submitted to ventilation (HV). The fetuses were harvested at 21.5 days of gestation. The morphometric variables measured were body weight (BW), total lung weight (TLW), left lung weight (LLW), and TLW/BW ratio. Pulmonary vascular measurements, VEGFR-1, VEGFR-2, VEGF, and eNOS immunohistochemistry were performed. The morphometric analysis showed decreased TLW and TLW/BW ratio in HV compared to C and H (P<0.005). Immunohistochemistry showed increased VEGFR-2/VEGF and decreased VEGFR-1 expression in H (P<0.05) and lower eNOS expression in H and HV. Median wall thickness was increased in H, and the expression of VEGFR-1, VEGFR-2, VEGF, and eNOS was altered, especially in neonates undergoing H and HV. These data suggested the occurrence of arteriolar wall changes mediated by NO and VEGF signaling in neonatal hypoxia.

Developmental neurotoxic effects of graphene oxide exposure in zebrafish larvae (Danio rerio).

Although graphene oxide (GO), a nanomaterial with hexagonal planar layer, has been widely studied due to its applications in neurobiology that include drug delivery and tissue engineering, additional studies to assess its potential toxic effects are still needed. Thus, this study evaluated the effects of GO exposure (at 5, 10, 50 or 100mg/L) during six consecutive days on mortality, hatching, spontaneous movement, heart rate, morphology, locomotion behavior, acetylcholinesterase (AChE) activity, dopamine levels and relative gene expression of developmental neurology-related genes using zebrafish larvae. In the 5mg/L dose, synapsin IIa expression up-regulation was seen concomitantly with down-regulation of dat expression, showing a potential compensatory mechanism. Moreover, the 10mg/L exposure caused an increase in heart rate, in absolute turn angle, brain cell damage and a decrease in dopamine levels. These alterations may be associated with autophagosome formation found in GO-exposed larval brain. No changes were observed on higher doses of GO exposure, probably due to nanomaterial agglomeration. Taken together, these results show that toxic effects of GO exposure are not dose-dependent, and are preeminent in lower concentrations. Additional studies are needed to deepen the specific mechanisms of GO neurotoxicity and are required to elucidate its potential biomedical use.

No iron fertilization in the equatorial Pacific Ocean during the last ice age.

The equatorial Pacific Ocean is one of the major high-nutrient, low-chlorophyll regions in the global ocean. In such regions, the consumption of the available macro-nutrients such as nitrate and phosphate is thought to be limited in part by the low abundance of the critical micro-nutrient iron. Greater atmospheric dust deposition could have fertilized the equatorial Pacific with iron during the last ice age--the Last Glacial Period (LGP)--but the effect of increased ice-age dust fluxes on primary productivity in the equatorial Pacific remains uncertain. Here we present meridional transects of dust (derived from the (232)Th proxy), phytoplankton productivity (using opal, (231)Pa/(230)Th and excess Ba), and the degree of nitrate consumption (using foraminifera-bound δ(15)N) from six cores in the central equatorial Pacific for the Holocene (0-10,000 years ago) and the LGP (17,000-27,000 years ago). We find that, although dust deposition in the central equatorial Pacific was two to three times greater in the LGP than in the Holocene, productivity was the same or lower, and the degree of nitrate consumption was the same. These biogeochemical findings suggest that the relatively greater ice-age dust fluxes were not large enough to provide substantial iron fertilization to the central equatorial Pacific. This may have been because the absolute rate of dust deposition in the LGP (although greater than the Holocene rate) was very low. The lower productivity coupled with unchanged nitrate consumption suggests that the subsurface major nutrient concentrations were lower in the central equatorial Pacific during the LGP. As these nutrients are today dominantly sourced from the Subantarctic Zone of the Southern Ocean, we propose that the central equatorial Pacific data are consistent with more nutrient consumption in the Subantarctic Zone, possibly owing to iron fertilization as a result of higher absolute dust fluxes in this region. Thus, ice-age iron fertilization in the Subantarctic Zone would have ultimately worked to lower, not raise, equatorial Pacific productivity.

Relationships between dendritic morphology, spatial distribution and firing patterns in rat layer 1 neurons

The cortical layer 1 contains mainly small interneurons, which have traditionally been classified according to their axonal morphology. The dendritic morphology of these cells, however, has received little attention and remains ill defined. Very little is known about how the dendritic morphology and spatial distribution of these cells may relate to functional neuronal properties. We used biocytin labeling and whole cell patch clamp recordings, associated with digital reconstruction and quantitative morphological analysis, to assess correlations between dendritic morphology, spatial distribution and membrane properties of rat layer 1 neurons. A total of 106 cells were recorded, labeled and subjected to morphological analysis. Based on the quantitative patterns of their dendritic arbor, cells were divided into four major morphotypes: horizontal, radial, ascendant, and descendant cells. Descendant cells exhibited a highly distinct spatial distribution in relation to other morphotypes, suggesting that they may have a distinct function in these cortical circuits. A significant difference was also found in the distribution of firing patterns between each morphotype and between the neuronal populations of each sublayer. Passive membrane properties were, however, statistically homogeneous among all subgroups. We speculate that the differences observed in active membrane properties might be related to differences in the synaptic input of specific types of afferent fibers and to differences in the computational roles of each morphotype in layer 1 circuits. Our findings provide new insights into dendritic morphology and neuronal spatial distribution in layer 1 circuits, indicating that variations in these properties may be correlated with distinct physiological functions.

Relationships between dendritic morphology, spatial distribution and firing patterns in rat layer 1 neurons.

The cortical layer 1 contains mainly small interneurons, which have traditionally been classified according to their axonal morphology. The dendritic morphology of these cells, however, has received little attention and remains ill defined. Very little is known about how the dendritic morphology and spatial distribution of these cells may relate to functional neuronal properties. We used biocytin labeling and whole cell patch clamp recordings, associated with digital reconstruction and quantitative morphological analysis, to assess correlations between dendritic morphology, spatial distribution and membrane properties of rat layer 1 neurons. A total of 106 cells were recorded, labeled and subjected to morphological analysis. Based on the quantitative patterns of their dendritic arbor, cells were divided into four major morphotypes: horizontal, radial, ascendant, and descendant cells. Descendant cells exhibited a highly distinct spatial distribution in relation to other morphotypes, suggesting that they may have a distinct function in these cortical circuits. A significant difference was also found in the distribution of firing patterns between each morphotype and between the neuronal populations of each sublayer. Passive membrane properties were, however, statistically homogeneous among all subgroups. We speculate that the differences observed in active membrane properties might be related to differences in the synaptic input of specific types of afferent fibers and to differences in the computational roles of each morphotype in layer 1 circuits. Our findings provide new insights into dendritic morphology and neuronal spatial distribution in layer 1 circuits, indicating that variations in these properties may be correlated with distinct physiological functions.

Avaliação da atividade cicatrizante do óleo de pequi (Caryocar coriaceum Wittm) em feridas cutâneas produzidas experimentalmente em ratos / Evaluation of the healing activity of pequi (Caryocar coriaceum Wittm) oil in cutaneous wounds induced experimentally in rats

O objetivo deste estudo foi demonstrar os efeitos do tratamento tópico do creme à base de óleo de pequi (Caryocar coriaceum Wittm) utilizando 40 ratos (Rattus norvegicus albinus) da linhagem Wistar, machos, com 60 dias de idade. Esses foram divididos em dois grupos: I) composto por 20 ratos com feridas cutâneas tratados com aplicação tópica do creme base com 10% de óleo de pequi; II) com o mesmo número de animais que receberam a aplicação tópica do creme base sem o óleo de pequi. Após antissepsia e anestesia local foi produzida cirurgicamente ferida circular de 1 cm de diâmetro na região dorso lombar. As lesões cutâneas foram avaliadas sob o aspecto clínico, morfométrica e histológico no 3o, 7o, 14o e 21o dias pós-operatório. No grupo tratado com creme à base de óleo de pequi houve aceleração na evolução do processo cicatricial. As feridas dos animais desse grupo apresentaram redução significativa a partir do décimo quarto dia pós-operatório, bem como foram verificados nesse período achados histológicos característicos da etapa final do processo de cicatrização tais como: acentuada quantidade de fibroblastos, fibras colágenas e completo processo de reepitelização, enquanto que as feridas do grupo controle necessitaram de mais tempo para resolução do processo cicatricial.

The main objective of this study was to demonstrate the effects of topical treatment with ointment containing pequi oil (Caryocar coriaceum Wittm), using 40 male 60-day-old mice (Rattus norvegicus albinus) from the Wistar line. These were divided into two groups: I) composed by 20 mice with cutaneous wounds treated by topical application of the ointment based on 10% pequi oil; II) the same number of mice, receiving the topical application of ointment without pequi oil. After antisepsis and local anesthesia, round 1-cm-diameter wounds were made on the lower back region. The wounds were evaluated in regard to clinical, morphometric and histological aspects on the 3rd, 7th, 14th and 21st postoperative days. The group treated with the pequi ointment presented acceleration in the healing process. The animals' wounds of this group showed a meaningful reduction from the 14th postoperative day, when histological characteristics from the ending of the healing process were noted, such as a large amount of fibroblasts, collagen fibers and a complete process of reepithelialization, while the wounds of the control group needed more time for the healing process.

A comparison of colony counts of breast milk using two methods of breast cleansing.

The purpose of this study was to identify if special breast cleansing before breast pumping would have an affect on lowering bacterial colony counts of cultured breast milk. Sixty-five women whose infants were being cared for in a NICU and who wished to pump their breasts for future breast milk feedings were randomly assigned to one of two groups: members of a control group were instructed to wash their hands thoroughly before breast pumping, and members of an experimental group were instructed to wash their hands thoroughly and were given special instructions on breast cleansing. All other breast pumping and milk collection instructions for both groups remained the same. A student's t-test revealed a significant difference between the two groups; women who performed special breast cleansing before breast pumping had significantly lower bacterial colony counts in their cultured breast milks.