28,983 research outputs found
Transport suction apparatus and absorption materials evaluation
The specific objectives were as follows. The effectiveness and function was evaluated of the hand held, manually powered v-vac for suction during microgravity. The function was evaluated of the battery powered laerdal suction unit in microgravity. The two units in control of various types of simulated bodily fluids were compared. Various types of tubing and attachments were evaluated which are required to control the collection of bodily fluids during transport. Various materials were evaluated for absorption of simulated bodily fluids. And potential problems were identified for waste management and containment of secretions and fluids during transport. Test procedures, results, and conclusions are briefly discussed
Towards the modeling of mucus draining from human lung: role of airways deformation on air-mucus interaction
Chest physiotherapy is an empirical technique used to help secretions to get
out of the lung whenever stagnation occurs. Although commonly used, little is
known about the inner mechanisms of chest physiotherapy and controversies about
its use are coming out regularly. Thus, a scientific validation of chest
physiotherapy is needed to evaluate its effects on secretions.
We setup a quasi-static numerical model of chest physiotherapy based on
thorax and lung physiology and on their respective biophysics. We modeled the
lung with an idealized deformable symmetric bifurcating tree. Bronchi and their
inner fluids mechanics are assumed axisymmetric. Static data from the
literature is used to build a model for the lung's mechanics. Secretions motion
is the consequence of the shear constraints apply by the air flow. The input of
the model is the pressure on the chest wall at each time, and the output is the
bronchi geometry and air and secretions properties.
In the limit of our model, we mimicked manual and mechanical chest
physiotherapy techniques. We show that for secretions to move, air flow has to
be high enough to overcome secretion resistance to motion. Moreover, the higher
the pressure or the quicker it is applied, the higher is the air flow and thus
the mobilization of secretions. However, pressures too high are efficient up to
a point where airways compressions prevents air flow to increases any further.
Generally, the first effects of manipulations is a decrease of the airway tree
hydrodynamic resistance, thus improving ventilation even if secretions do not
get out of the lungs. Also, some secretions might be pushed deeper into the
lungs; this effect is stronger for high pressures and for mechanical chest
physiotherapy. Finally, we propose and tested two adimensional numbers that
depend on lung properties and that allow to measure the efficiency and comfort
of a manipulation
Glutathione s-transferase omega in the lung and sputum supernatants of COPD patients
BACKGROUND: The major contribution to oxidant related lung damage in COPD is from the
oxidant/antioxidant imbalance and possibly impaired antioxidant defence. Glutathione (GSH) is one
of the most important antioxidants in human lung and lung secretions, but the mechanisms
participating in its homeostasis are partly unclear. Glutathione-S-transferase omega (GSTO) is a
recently characterized cysteine containing enzyme with the capability to bind and release GSH in
vitro. GSTO has not been investigated in human lung or lung diseases.
METHODS: GSTO1-1 was investigated by immunohistochemistry and Western blot analysis in 72
lung tissue specimens and 40 sputum specimens from non-smokers, smokers and COPD, in
bronchoalveolar lavage fluid and in plasma from healthy non-smokers and smokers. It was also
examined in human monocytes and bronchial epithelial cells and their culture mediums in vitro.
RESULTS: GSTO1-1 was mainly expressed in alveolar macrophages, but it was also found in airway
and alveolar epithelium and in extracellular fluids including sputum supernatants, bronchoalveolar
lavage fluid, plasma and cell culture mediums. The levels of GSTO1-1 were significantly lower in the
sputum supernatants (p = 0.023) and lung homogenates (p = 0.003) of COPD patients than in nonsmokers.
CONCLUSION: GSTO1-1 is abundant in the alveolar macrophages, but it is also present in
extracellular fluids and in airway secretions, the levels being decreased in COPD. The clinical
significance of GSTO1-1 and its role in regulating GSH homeostasis in airway secretions, however,
needs further investigations
EBOV-RNA test with RT-PCR in ocular fluids of Ebola survivors can help to safely perform cataract surgery
Since the Ebola virus (EBOV) was discovered in 1976, the recent 2014â2016 Ebola virus disease (EVD) outbreak in West Africa was the largest with 28,600 cases and about 11,300 deaths. This epidemic started in Guinea and spread rapidly across the borders in Sierra Leone and Liberia (1). After an incubation period of 2 to 21 days EBOV manifests clinically as a hemorrhagic fever that can lead to death by hypovolemic shock and multisystem failure generally within a month of infection. Human-to-human transmission of EBOV occurs by direct contact (through cutaneous or mucosal lesions) with blood, secretions, organs or other body fluids of infected persons, and by indirect contact with environments contaminated with such fluids
Electrophysiological responses to conspecific odorants in Xenopus laevis show potential for chemical signaling
The fully aquatic African clawed frog, Xenopus laevis, has an unusual and highly adapted nose that allows it to separately sample both airborne and waterborne stimuli. The function of the adult water nose has received little study, despite the fact that it is quite likely to receive information about conspecifics through secretions released into the water and could aid the frog in making decisions about social and reproductive behaviors. To assess the potential for chemical communication in this species, we developed an in situ electroolfactogram preparation and tested the olfactory responses of adult males to cloacal fluids and skin secretions from male and female conspecifics. We found robust olfactory responses to all conspecific stimuli, with greatest sensitivity to female cloacal fluids. These results open the door to further testing to identify compounds within cloacal fluids and skin secretions that are driving these responses and examine behavioral responses to those compounds. Understanding the role of chemical communication in social and reproductive behaviors may add to our rich understanding of vocal communication to create a more complete picture of social behavior in this species
HIV-1 RNA Levels and Antiretroviral Drug Resistance in Blood and Non-Blood Compartments from HIV-1âInfected Men and Women enrolled in AIDS Clinical Trials Group Study A5077
Background: Detectable HIV-1 in body compartments can lead to transmission and antiretroviral resistance. Although sex differences in viral shedding have been demonstrated, mechanisms and magnitude are unclear. We compared RNA levels in blood, genital-secretions and saliva; and drug resistance in plasma and genital-secretions of men and women starting/changing antiretroviral therapy (ART) in the AIDS Clinical Trials Group (ACTG) 5077 study. Methods: Blood, saliva and genital-secretions (compartment fluids) were collected from HIV-infected adults (â„13 years) at 14 United-States sites, who were initiating or changing ART with plasma viral load (VL) â„2,000 copies/mL. VL testing was performed on all compartment fluids and HIV resistance genotyping on plasma and genital-secretions. Spearman rank correlations were used to evaluate concordance and Fisherâs and McNemarâs exact tests to compare VL between sexes and among compartments. Results: Samples were available for 143 subjects; 36% treated (23 men, 29 women) and 64% âuntreatedâ (40 men, 51 women). RNA detection was significantly more frequent in plasma (100%) than genital-secretions (57%) and saliva (64%) (P<0.001). A higher proportion of men had genital shedding versus women (78% versus 41%), and RNA detection was more frequent in saliva versus genital-secretions in women when adjusted for censoring at the limit of assay detection. Inter-compartment fluid VL concordance was low in both sexes. In 22 (13 men, 9 women) paired plasma-genital-secretion genotypes from treated subjects, most had detectable resistance in both plasma (77%) and genital-secretions (68%). Resistance discordance was observed between compartments in 14% of subjects. Conclusions: HIV shedding and drug resistance detection prior to initiation/change of ART in ACTG 5077 subjects differed among tissues and between sexes, making the gold standard blood-plasma compartment assessment not fully representative of HIV at other tissue sites. Mechanisms of potential sex-dependent tissue compartmentalization should be further characterized to aid in optimizing treatment and prevention of HIV transmission. Trial Registration ClinicalTrials.gov NCT0000748
Lactoferrin. A natural glycoprotein involved in iron and inflammatory homeostasis
Human lactoferrin (hLf), an iron-binding multifunctional cationic glycoprotein secreted by exocrine glands and by neutrophils, is a key element of host defenses. HLf and bovine Lf (bLf), possessing high sequence homology and identical functions, inhibit bacterial growth and biofilm dependently from iron binding ability while, independently, bacterial adhesion to and the entry into cells. In infected/inflamed host cells, bLf exerts an anti-inflammatory activity against interleukin-6 (IL-6), thus up-regulating ferroportin (Fpn) and transferrin receptor 1 (TfR1) and down-regulating ferritin (Ftn), pivotal actors of iron and inflammatory homeostasis (IIH). Consequently, bLf inhibits intracellular iron overload, an unsafe condition enhancing in vivo susceptibility to infections, as well as anemia of inflammation (AI), re-establishing IIH. In pregnant women, affected by AI, bLf oral administration decreases IL-6 and increases hematological parameters. This surprising effect is unrelated to iron supplementation by bLf (80 ”g instead of 1-2 mg/day), but to its role on IIH. AI is unrelated to the lack of iron, but to iron delocalization: cellular/tissue overload and blood deficiency. BLf cures AI by restoring iron from cells to blood through Fpn up-expression. Indeed, anti-inflammatory activity of oral and intravaginal bLf prevents preterm delivery. Promising bLf treatments can prevent/cure transitory inflammation/anemia/oral pathologies in athletes
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