OBJECTIVES:Atelectasis develops in critically ill obese patients when undergoing mechanical ventilation due to increased pleural pressure. The current study aimed to determine the relationship ...between transpulmonary pressure, lung mechanics, and lung morphology and to quantify the benefits of a decremental positive end-expiratory pressure trial preceded by a recruitment maneuver.
DESIGN:Prospective, crossover, nonrandomized interventional study.
SETTING:Medical and Surgical Intensive Care Units at Massachusetts General Hospital (Boston, MA) and University Animal Research Laboratory (São Paulo, Brazil).
PATIENTS/SUBJECTS:Critically ill obese patients with acute respiratory failure and anesthetized swine.
INTERVENTIONS:Clinical data from 16 mechanically ventilated critically ill obese patients were analyzed. An animal model of obesity with reversible atelectasis was developed by placing fluid filled bags on the abdomen to describe changes of lung mechanics, lung morphology, and pulmonary hemodynamics in 10 swine.
MEASUREMENTS AND MAIN RESULTS:In obese patients (body mass index, 48 ± 11 kg/m), 21.7 ± 3.7 cm H2O of positive end-expiratory pressure resulted in the lowest elastance of the respiratory system (18.6 ± 6.1 cm H2O/L) after a recruitment maneuver and decremental positive end-expiratory pressure and corresponded to a positive (2.1 ± 2.2 cm H2O) end-expiratory transpulmonary pressure. Ventilation at lowest elastance positive end-expiratory pressure preceded by a recruitment maneuver restored end-expiratory lung volume (30.4 ± 9.1 mL/kg ideal body weight) and oxygenation (273.4 ± 72.1 mm Hg). In the swine model, lung collapse and intratidal recruitment/derecruitment occurred when the positive end-expiratory transpulmonary pressure decreased below 2–4 cm H2O. After the development of atelectasis, a decremental positive end-expiratory pressure trial preceded by lung recruitment identified the positive end-expiratory pressure level (17.4 ± 2.1 cm H2O) needed to restore poorly and nonaerated lung tissue, reestablishing lung elastance and oxygenation while avoiding increased pulmonary vascular resistance.
CONCLUSIONS:In obesity, low-to-negative values of transpulmonary pressure predict lung collapse and intratidal recruitment/derecruitment. A decremental positive end-expiratory pressure trial preceded by a recruitment maneuver reverses atelectasis, improves lung mechanics, distribution of ventilation and oxygenation, and does not increase pulmonary vascular resistance.
•Some components of the renin-angiotensin system (RAS) are altered under conditions of estrogen deficiency and hypertension.•Exercise training reverses the detrimental effects of ovariectomy on the ...aortic reactivity to ANG II and ANG-(1-7) in hypertensive rats.•Exercise training modulates RAS independently of estrogen therapy, protecting the hypertensive postmenopausal women against CVD.
The renin-angiotensin-system is an important component of cardiovascular control and is up-regulated under various conditions, including hypertension and menopause. The aim of this study was to evaluate the effects of swimming training and estrogen therapy (ET) on angiotensin-II (ANG II)-induced vasoconstriction and angiotensin-(1-7) ANG-(1-7)-induced vasorelaxation in aortic rings from ovariectomized spontaneously hypertensive rats. Animals were divided into Sham (SH), Ovariectomized (OVX), Ovariectomized treated with E2 (OE2), Ovariectomized plus swimming (OSW) and Ovariectomized treated with E2 plus swimming (OE2+SW) groups. ET entailed the administration of 5μg of 17β-Estradiol three times per week. Swimming was undertaken for sixty minutes each day, five times per week. Both, training and ET were initiated seven days following ovariectomy. Forty-eight hours after the last treatment or training session, the animals’ systolic blood pressures were measured, and blood samples were collected to measure plasma ANG II and ANG-(1-7) levels via radioimmunoassay. In aortic rings, the vascular reactivity to ANG II and ANG-(1-7) was assessed. Expression of ANG-(1-7) in aortic wall was analyzed by immunohistochemistry. The results showed that both exercise and ET increased plasma ANG II levels despite attenuating systolic blood pressure. Ovariectomy increased constrictor responses to ANG II and decreased dilatory responses to ANG-(1-7), which were reversed by swimming independently of ET. Moreover, it was observed an apparent increase in ANG-(1-7) content in the aorta of the groups subjected to training and ET. Exercise training may play a cardioprotective role independently of ET and may be an alternative to ET in hypertensive postmenopausal women.
Sex differences in the human olfactory function reportedly exist for olfactory sensitivity, odorant identification and memory, and tasks in which odors are rated based on psychological features such ...as familiarity, intensity, pleasantness, and others. Which might be the neural bases for these behavioral differences? The number of cells in olfactory regions, and especially the number of neurons, may represent a more accurate indicator of the neural machinery than volume or weight, but besides gross volume measures of the human olfactory bulb, no systematic study of sex differences in the absolute number of cells has yet been undertaken. In this work, we investigate a possible sexual dimorphism in the olfactory bulb, by quantifying postmortem material from 7 men and 11 women (ages 55-94 years) with the isotropic fractionator, an unbiased and accurate method to estimate absolute cell numbers in brain regions. Female bulbs weighed 0.132 g in average, while male bulbs weighed 0.137 g, a non-significant difference; however, the total number of cells was 16.2 million in females, and 9.2 million in males, a significant difference of 43.2%. The number of neurons in females reached 6.9 million, being no more than 3.5 million in males, a difference of 49.3%. The number of non-neuronal cells also proved higher in women than in men: 9.3 million and 5.7 million, respectively, a significant difference of 38.7%. The same differences remained when corrected for mass. Results demonstrate a sex-related difference in the absolute number of total, neuronal and non-neuronal cells, favoring women by 40-50%. It is conceivable that these differences in quantitative cellularity may have functional impact, albeit difficult to infer how exactly this would be, without knowing the specific circuits cells make. However, the reported advantage of women as compared to men may stimulate future work on sex dimorphism of synaptic microcircuitry in the olfactory bulb.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Introduction In this study, we aimed to assess the relationship between normative and perceived orthodontic treatment need associated with quality of life, self-esteem, and self-perception. Methods ...The sample included 248 schoolchildren aged 12 years. The normative aspect of orthodontic treatment was assessed by the Dental Health Component and the Aesthetic Component of the Index of Orthodontic Treatment Need. The subjects were further evaluated for their oral health-related quality of life, self-esteem, and self-perception of oral esthetics. The Aesthetic Component of the Index of Orthodontic Treatment Need was considered as the response variable, and generalized linear models estimated by the GENMOD procedure (release 9.3, 2010; SAS Institute, Cary, NC). Model 1 was estimated with only the intercept, providing the basis for evaluating the reduction in variance in the other models studied; then the variables were tested sequentially, considering P ≤0.05 as the criterion for remaining in the model. Results In the model, self-perception and self-esteem were statistically significant in relation to the perceived need for treatment. The normative need was significantly associated with the outcome variable and was not influenced by independent variables. Conclusions The normative need for orthodontics treatment was not overestimated by the perceived need, and the perceived need was not influenced by sex and the impact on quality of life.
Angiotensin-converting enzyme 2 (ACE2) converts the vasopressor angiotensin II (Ang II) into angiotensin (1-7) Ang(1-7), a peptide reported to have vasodilatory and cardioprotective properties. ...Inactivation of the ACE2 gene in mice has been reported by one group to result in an accumulation of Ang II in the heart and an age-related defect in cardiac contractility. A second study confirmed the role of ACE2 as an Ang II clearance enzyme but failed to reproduce the contractility defects previously reported in ACE2-deficient mice. The reasons for these differences are unclear but could include differences in the accumulation of Ang II or the deficiencies in Ang(1-7) in the mouse models used. As a result, the roles of ACE2, Ang II, and Ang(1-7) in the heart remain controversial. Using a novel strategy, we targeted the chronic overproduction of either Ang II or Ang(1-7) in the heart of transgenic mice and tested their effect on age-related contractility and on cardiac remodeling in response to a hypertensive challenge. We demonstrate that a chronic accumulation of Ang II in the heart does not result in cardiac contractility defects, even in older (8-month-old) mice. Likewise, transgenic animals with an 8-fold increase in Ang(1-7) peptide in the heart exhibited no differences in resting blood pressure or cardiac contractility as compared to age-matched controls, but they had significantly less ventricular hypertrophy and fibrosis than their nontransgenic littermates in response to a hypertensive challenge. Analysis of downstream signaling cascades demonstrates that cardiac Ang(1-7) selectively modulates some of the downstream signaling effectors of cardiac remodeling. These results suggest that Ang(1-7) can reduce hypertension-induced cardiac remodeling through a direct effect on the heart and raise the possibility that pathologies associated with ACE2 inactivation are mediated in part by a decrease in production of Ang(1-7).
This study aimed to explore the perception of orthodontic treatment need by using the Dental Aesthetic Index (DAI) and the Index of Orthodontic Treatment Need (IOTN).
A cross-sectional study was ...conducted on a representative random sample (N = 248) of adolescents aged 12 years. The DAI and both components of IOTN were used to evaluate malocclusion. The association between the Dental Health Component of the IOTN with gender and ethnic group were analyzed by chi-square test. The concordances between the indexes were analyzed by the kappa statistic, with 95% confidence intervals (CIs).
The prevalence of adolescents with high severity and orthodontic treatment need was 10.5% (95% CI, 6.7-14.3), 36.5% (95% CI, 32.3-44.3), and 73.4% (95% CI, 67.9-78.9) for the Aesthetic Component of the IOTN, Dental Health Component of the IOTN, and DAI, respectively. The indexes showed high agreement for the cases with low treatment need, whereas low concordance was observed for the cases with high treatment need.
The perception of orthodontic treatment need was assessed differently using DAI and IOTN.
•Index of Orthodontic Treatment Need and Dental Aesthetic Index assess orthodontic treatment need differently.•For low treatment need, the agreement was high.•For high treatment need, the concordance was low.
The impact of water deficit on sucrose metabolism in sink organs like the fruit remains poorly known despite the need to improve fruit crops resilience to drought in the face of climate change. The ...present study investigated the effects of water deficit on sucrose metabolism and related gene expression in tomato fruits, aiming to identify candidate genes for improving fruit quality upon low water availability. Tomato plants were subjected to irrigated control and water deficit (−60% water supply compared to control) treatments, which were applied from the first fruit set to first fruit maturity stages. The results have shown that water deficit significantly reduced fruit dry biomass and number, among other plant physiological and growth variables, but substantially increased the total soluble solids content. The determination of soluble sugars on the basis of fruit dry weight revealed an active accumulation of sucrose and concomitant reduction in glucose and fructose levels in response to water deficit. The complete repertoire of genes encoding sucrose synthase (
SUSY1-7
), sucrose-phosphate synthase (
SPS1-4
), and cytosolic (
CIN1-8
), vacuolar (
VIN1-2
) and cell wall invertases (
WIN1-4
) was identified and characterized, of which
SlSUSY4
,
SlSPS1
,
SlCIN3
,
SlVIN2
, and
SlCWIN2
were shown to be positively regulated by water deficit. Collectively, these results show that water deficit regulates positively the expression of certain genes from different gene families related to sucrose metabolism in fruits, favoring the active accumulation of sucrose in this organ under water-limiting conditions.
Although increasing evidence confirms neuropsychiatric manifestations associated mainly with severe COVID-19 infection, long-term neuropsychiatric dysfunction (recently characterized as part of “long ...COVID-19” syndrome) has been frequently observed after mild infection. We show the spectrum of cerebral impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, ranging from long-term alterations in mildly infected individuals (orbitofrontal cortical atrophy, neurocognitive impairment, excessive fatigue and anxiety symptoms) to severe acute damage confirmed in brain tissue samples extracted from the orbitofrontal region (via endonasal transethmoidal access) from individuals who died of COVID-19. In an independent cohort of 26 individuals who died of COVID-19, we used histopathological signs of brain damage as a guide for possible SARS-CoV-2 brain infection and found that among the 5 individuals who exhibited those signs, all of them had genetic material of the virus in the brain. Brain tissue samples from these five patients also exhibited foci of SARS-CoV-2 infection and replication, particularly in astrocytes. Supporting the hypothesis of astrocyte infection, neural stem cell–derived human astrocytes in vitro are susceptible to SARS-CoV-2 infection through a noncanonical mechanism that involves spike–NRP1 interaction. SARS-CoV-2–infected astrocytes manifested changes in energy metabolism and in key proteins and metabolites used to fuel neurons, as well as in the biogenesis of neurotransmitters. Moreover, human astrocyte infection elicits a secretory phenotype that reduces neuronal viability. Our data support the model in which SARS-CoV-2 reaches the brain, infects astrocytes, and consequently, leads to neuronal death or dysfunction. These deregulated processes could contribute to the structural and functional alterations seen in the brains of COVID-19 patients.
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