Normal Respiration Research Articles

Chemical kinetic characteristics of methane/air mixture explosion and its affecting factors

Gas explosion in coal mines caused a large number of deaths, injuries and property losses. Gas explosion still happens occasionally in recent years. It is known that most people died from CO poisoning in gas explosion. But the details of toxic gases produced and their impacts on people need further investigation. In order to study the products and species in gas explosion, an analysis of chemical kinetic characteristics was conducted using CHEMKIN III with detailed mechanism (GRI-Mech3.0) package. A closed homogeneous 0-D reactor was adopted to investigate the kinetic behavior of gas explosion. The initial conditions were set, similar to those in the real tunnel environment. The profiles of four reactants, toxic gases and free radicals were obtained. The threshold values of people exposed to different poisonous gases were analyzed to study their impacts on people. Sensitivity analysis of key elementary reaction to free radical was performed to find possible reactions which can suppress gas explosion. The results show that the ignition delay time is the longest at fuel-rich condition. The O2 concentration decreases from 19% to 2% at stoichiometric ratio, which could not support normal respiration after explosion. It is found that the concentration of CO ranks the highest among the four toxic gases. Toxicity analysis indicates that those exposed to such condition will soon die of asphyxia. This is consistent with the accident investigation findings that the majority of fatalities result from inhalation of CO. The concentration of CO at fuel-rich condition is higher than that at fuel-lean condition. The relationship between the final free radical concentration and initial CH4 concentration exhibits a reverse U shape. Sensitivity analysis reveals that free radicals are mostly sensitive to the intermediate reaction R156 (forward direction) and R158 (reverse direction). It provides a possible direction to research the corresponding chemicals for gas explosion suppression. This work would provide theoretical support for gas explosion suppression technology and decision-making of personal protection in rescuing trapped coal miners. It is of great importance for developing suppression chemicals of gas explosion.

Fumarate hydratase is a critical metabolic regulator of hematopoietic stem cell functions.

Strict regulation of stem cell metabolism is essential for tissue functions and tumor suppression. In this study, we investigated the role of fumarate hydratase (Fh1), a key component of the mitochondrial tricarboxylic acid (TCA) cycle and cytosolic fumarate metabolism, in normal and leukemic hematopoiesis. Hematopoiesis-specific Fh1 deletion (resulting in endogenous fumarate accumulation and a genetic TCA cycle block reflected by decreased maximal mitochondrial respiration) caused lethal fetal liver hematopoietic defects and hematopoietic stem cell (HSC) failure. Reexpression of extramitochondrial Fh1 (which normalized fumarate levels but not maximal mitochondrial respiration) rescued these phenotypes, indicating the causal role of cellular fumarate accumulation. However, HSCs lacking mitochondrial Fh1 (which had normal fumarate levels but defective maximal mitochondrial respiration) failed to self-renew and displayed lymphoid differentiation defects. In contrast, leukemia-initiating cells lacking mitochondrial Fh1 efficiently propagated Meis1/Hoxa9-driven leukemia. Thus, we identify novel roles for fumarate metabolism in HSC maintenance and hematopoietic differentiation and reveal a differential requirement for mitochondrial Fh1 in normal hematopoiesis and leukemia propagation.

Gender Linked Metric Analysis of Portal Vein: A Sonographic Appraisal.

Portal hypertension is one of the most mystifying and disconcerting abdominal ailment. Ultrasonography (USG) is an effective diagnostic tool for its prompt management. Knowledge of normal calibre of portal vein in a local setting is essential as literature reports contrasting values in different regions. It helps in early diagnosis of portal hypertension even before it is clinically manifested thereby assisting clinicians and interventional radiologists in pertinent management. Study was aimed to evaluate the Portal Vein Diameter (PVD) and find its correlation with gender by using USG in North Indian population. A total of 300 healthy adults were included in the study. Portal vein diameter was measured in supine position and normal respiration by grey scale USG. The portal vein diameter was correlated with age and gender statistically using independent Student's t-test and ANOVA. Mean PVD of (9.49±1.03 mm) was observed in the present cross-sectional study. Male showed a significantly higher mean PVD (9.70±1.02 mm) as compared to females (9.10±0.94 mm). Scarcity of information concerning ultrasonographically measured standard portal vein diameter and inconstant values reported in literature necessitates the need for establishing local standard value. In the given subset of population the portal vein diameter was influenced by the gender. The information will be helpful in prompt diagnosis and management of portal hypertension.

The Search of Vagal Pulmonary Pleural Innervation

The visceral pleura envelops the lung lobes. The visceral and parietal pleurae form the pleural cavity with negative pressure to keep the normal respiration possible. The lungs are complicatedly innervated by bilateral vagal and spinal nerves that have the sensory and motor components. Pulmonary vagal sensory receptors have been identified within the tissues in the extrapulmonary and intrapulmonary airways. However, vagal vs. spinal innervation in the pulmonary visceral pleura has been undecided. Möllgaard (1912) determined the neurons that innervate the lungs by whole or partial extirpation of the lung lobe. Larsell (1922) examined the vagal degeneration in the lungs and supported the vagal origin. However, Larsell and Coffey (1928) turned to the spinal origin when they inserted the balloon between the lung lobe and the chest wall or diaphragm and found no change in the rate and depth of inspiration. With vagotomy and excision of the second and third thoracic spinal ganglia, Honjin (1956) determined the vagal and rejected the spinal origin. With vagotomy, Pintelon and colleague (2007) identified non-vagal ＂visceral pleura receptors＂. Recently, we identified the classical hilar and novel non-hilar vagal pleural innervation pathways and two kinds of vagal nerve endings in the visceral pleura and triangular ligaments. Most of the areas that face the dorsal thoracic cavity have no vagal innervation, whereas the interlobar areas and those areas that face the heart receive bilateral or unilateral vagal innervation with a left-vagus-rostral-lung vs. right-vagus-caudal-lung lateralized innervation pattern. The experimental considerations and meanings for the vagal innervation pattern are discussed.

In Vivo Measurements of T2 Relaxation Time of Mouse Lungs during Inspiration and Expiration.

PurposeThe interest in measurements of magnetic resonance imaging relaxation times, T1, T2, T2*, with intention to characterize healthy and diseased lungs has increased recently. Animal studies play an important role in this context providing models for understanding and linking the measured relaxation time changes to the underlying physiology or disease. The aim of this work was to study how the measured transversal relaxation time (T2) in healthy lungs is affected by normal respiration in mouse.MethodT2 of lung was measured in anaesthetized freely breathing mice. Image acquisition was performed on a 4.7 T, Bruker BioSpec with a multi spin-echo sequence (Car-Purcell-Meiboom-Gill) in both end-expiration and end-inspiration. The echo trains consisted of ten echoes of inter echo time 3.5 ms or 4.0 ms. The proton density, T2 and noise floor were fitted to the measured signals of the lung parenchyma with a Levenberg-Marquardt least-squares three-parameter fit.ResultsT2 in the lungs was longer (p<0.01) at end-expiration (9.7±0.7 ms) than at end-inspiration (9.0±0.8 ms) measured with inter-echo time 3.5 ms. The corresponding relative proton density (lung/muscle tissue) was higher (p<0.001) during end-expiration, (0.61±0.06) than during end-inspiration (0.48±0.05). The ratio of relative proton density at end-inspiration to that at end-expiration was 0.78±0.09. Similar results were found for inter-echo time 4.0 ms and there was no significant difference between the T2 values or proton densities acquired with different interecho times. The T2 value increased linearly (p< 0.001) with proton density.ConclusionThe measured T2 in-vivo is affected by diffusion across internal magnetic susceptibility gradients. In the lungs these gradients are modulated by respiration, as verified by calculations. In conclusion the measured T2 was found to be dependent on the size of the alveoli.

Calcium channel regulator Mid1 links TORC2-mediated changes in mitochondrial respiration to autophagy.

Autophagy is a catabolic process that recycles cytoplasmic contents and is crucial for cell survival during stress. The target of rapamycin (TOR) kinase regulates autophagy as part of two distinct protein complexes, TORC1 and TORC2. TORC1 negatively regulates autophagy according to nitrogen availability. In contrast, TORC2 functions as a positive regulator of autophagy during amino acid starvation, via its target kinase Ypk1, by repressing the activity of the calcium-dependent phosphatase calcineurin and promoting the general amino acid control (GAAC) response. Precisely how TORC2-Ypk1 signaling regulates calcineurin within this pathway remains unknown. Here we demonstrate that activation of calcineurin requires Mid1, an endoplasmic reticulum-localized calcium channel regulatory protein implicated in the oxidative stress response. We find that normal mitochondrial respiration is perturbed in TORC2-Ypk1-deficient cells, which results in the accumulation of mitochondrial-derived reactive oxygen species that signal to Mid1 to activate calcineurin, thereby inhibiting the GAAC response and autophagy. These findings describe a novel pathway involving TORC2, mitochondrial oxidative stress, and calcium homeostasis for autophagy regulation.

Vagal nerve endings in visceral pleura and triangular ligaments of the rat lung.

The inner thoracic cavity is lined by the parietal pleura, and the lung lobes are covered by the visceral pleura. The parietal and visceral plurae form the pleural cavity that has negative pressure within to enable normal respiration. The lung tissues are bilaterally innervated by vagal and spinal nerves, including sensory and motor components. This complicated innervation pattern has made it difficult to discern the vagal vs. spinal processes in the pulmonary visceral pleura. With and without vagotomy, we identified vagal nerve fibres and endings distributed extensively in the visceral pleura ('P'-type nerve endings) and triangular ligaments ('L'-type nerve endings) by injecting wheat germ agglutinin-horseradish peroxidase as a tracer into the nucleus of solitary tract or nodose ganglion of male Sprague-Dawley rats. We found the hilar and non-hilar vagal pulmonary pleural innervation pathways. In the hilar pathway, vagal sub-branches enter the hilum and follow the pleural sheet to give off the terminal arborizations. In the non-hilar pathway, vagal sub-branches run caudally along the oesophagus and either directly enter the ventral-middle-mediastinal left lobe or follow the triangular ligaments to enter the left and inferior lobe. Both vagi innervate: (i) the superior, middle and accessory lobes on the ventral surfaces that face the heart; (ii) the dorsal-rostral superior lobe; (iii) the dorsal-caudal left lobe; and (iv) the left triangular ligament. Innervated only by the left vagus is: (i) the ventral-rostral and dorsal-rostral left lobe via the hilar pathway; (ii) the ventral-middle-mediastinal left lobe and the dorsal accessory lobe that face the left lobe via the non-hilar pathway; and (iii) the ventral-rostral inferior lobe that faces the heart. Innervated only by the right vagus, via the non-hilar pathway, is: (i) the inferior (ventral and dorsal) and left (ventral only) lobe in the area near the triangular ligament; (ii) the dorsal-middle-mediastinal left lobe; and (iii) the right triangular ligament. Other regions innervated with unknown vagal pathways include: (i) the middle lobe that faces the superior and inferior lobe; (ii) the rostral-mediastinal inferior lobe that faces the middle lobe; and (iii) the ventral accessory lobe that faces the diaphragm. Our study demonstrated that most areas that face the dorsal thoracic cavity have no vagal innervation, whereas the interlobar and heart-facing areas are bilaterally or unilaterally innervated with a left-rostral vs. right-caudal lateralized innervation pattern. This innervation pattern may account for the fact that the respiratory regulation in rats has a lateralized right-side dominant pattern.

Abstract 12609: Impaired Mitochondrial Respiration Precedes Clinical Heart Failure in Right Ventricular Pressure Overload

Introduction: Congenital heart disease patients with right-sided obstruction have increased stress on the right ventricle (RV) leading to right ventricular hypertrophy (RVH) and failure (RVF). The critical role of mitochondrial energetics in the development of RVH and RVF is not known. We hypothesize that mitochondrial dysfunction contributes to the chronic energy deficit and mechanical dysfunction in heart failure. Methods: Adult, male FVB mice underwent pulmonary artery banding (PAB) to induce RVH (n=9) and RVF (n=4) and were compared to sham-operated controls (n=9). We used a high-resolution Oxygraph2K respirometer to measure oxygen consumption in tissue and in isolated mitochondria from the RV free wall. We evaluated leak respiration during substrate utilization by complex 1-NADH dehydrogenase and complex 2-succinate dehydrogenase and during maximal ATP generation by complex 5-ATP synthase. Groups were compared using ANOVA. Data is presented as mean ± SEM (*p&lt;0.05). Results: All mice had a PAB gradient of 30-40 mmHg by echocardiography. RVH mice had preserved systolic function while RVF mice had heart failure (ascites, tachypnea, hepatomegaly) and decreased function (Table). RVH showed preserved complex 1 mediated respiration but lower complex 2 and 5 respiration and lower respiratory control ratios (RCR) while in RVF, all complexes showed impaired respiration (Table). However, isolated mitochondria from RVF demonstrated preserved respiratory capacity when supplied with exogenous substrates and no change in complex levels. Conclusion: Mitochondrial respiration is impaired even in stable RVH and progressively worsens in RVF in vivo. Interestingly, isolated mitochondria show normal respiration in RVF when supplied with substrates ex vivo suggesting a defect with substrate delivery rather than intrinsic mitochondrial function. Strategies to enhance substrate delivery may improve ATP generation and thereby preserve function in heart failure.

The Assembly Factor SDHAF2 Is Dispensable for Flavination of the Catalytic Subunit of Mitochondrial Complex II in Breast Cancer Cells

Mitochondrial complex II or succinate dehydrogenase (SDH) is at the crossroads of oxidative phosphorylation and the tricarboxylic acid cycle. It has been shown that Sdh5 (SDHAF2/SDH5 in mammals) is required for flavination of the subunit Sdh1 (SDHA in human cells) in yeast. Here we demonstrate that in human breast cancer cells, SDHAF2/SDH5 is dispensable for SDHA flavination. In contrast to yeast, CRISPR-Cas9 nickase-mediated SDHAF2 KO breast cancer cells feature flavinated SDHA and retain fully assembled and functional complex II, as well as normal mitochondrial respiration. Our data show that SDHA flavination is independent of SDHAF2 in breast cancer cells, employing an alternative mechanism.

How to Effectively Use High-Resolution Esophageal Manometry

How to Effectively Use High-Resolution Esophageal Manometry

Retrospective 4D MR image construction from free-breathing slice Acquisitions: A novel graph-based approach.

Dynamic or 4D imaging of the thorax has many applications. Both prospective and retrospective respiratory gating and tracking techniques have been developed for 4D imaging via CT and MRI. For pediatric imaging, due to radiation concerns, MRI becomes the de facto modality of choice. In thoracic insufficiency syndrome (TIS), patients often suffer from extreme malformations of the chest wall, diaphragm, and/or spine with inability of the thorax to support normal respiration or lung growth (Campbell etal., 2003, Campbell and Smith, 2007), as such patient cooperation needed by some of the gating and tracking techniques are difficult to realize without causing patient discomfort and interference with the breathing mechanism itself. Therefore (ventilator-supported) free-breathing MRI acquisition is currently the best choice for imaging these patients. This, however, raises a question of how to create a consistent 4D image from such acquisitions. This paper presents a novel graph-based technique for compiling the best 4D image volume representing the thorax over one respiratory cycle from slice images acquired during unencumbered natural tidal-breathing of pediatric TIS patients. In our approach, for each coronal (or sagittal) slice position, images are acquired at a rate of about 200-300ms/slice over several natural breathing cycles which yields over 2000 slices. A weighted graph is formed where each acquired slice constitutes a node and the weight of the arc between two nodes defines the degree of contiguity in space and time of the two slices. For each respiratory phase, an optimal 3D spatial image is constructed by finding the best path in the graph in the spatial direction. The set of all such 3D images for a given respiratory cycle constitutes a 4D image. Subsequently, the best 4D image among all such constructed images is found over all imaged respiratory cycles. Two types of evaluation studies are carried out to understand the behavior of this algorithm and in comparison to a method called Random Stacking - a 4D phantom study and 10 4D MRI acquisitions from TIS patients and normal subjects. The 4D phantom was constructed by 3D printing the pleural spaces of an adult thorax, which were segmented in a breath-held MRI acquisition. Qualitative visual inspection via cine display of the slices in space and time and in 3D rendered form showed smooth variation for all data sets constructed by the proposed method. Quantitative evaluation was carried out to measure spatial and temporal contiguity of the slices via segmented pleural spaces. The optimal method showed smooth variation of the pleural space as compared to Random Stacking whose behavior was erratic. The volumes of the pleural spaces at the respiratory phase corresponding to end inspiration and end expiration were compared to volumes obtained from breath-hold acquisitions at roughly the same phase. The mean difference was found to be roughly 3%. The proposed method is purely image-based and post-hoc and does not need breath holding or external surrogates or instruments to record respiratory motion or tidal volume. This is important and practically warranted for pediatric patients. The constructed 4D images portray spatial and temporal smoothness that should be expected in a consistent 4D volume. We believe that the method can be routinely used for thoracic 4D imaging.

Anatomical and functional deficiencies of the crural diaphragm in patients with esophagitis.

Inspiratory esophagogastric junction (EGJ) pressure is lower in gastroesophageal reflux disease (GERD) and patients fail to increase EGJ pressure during the inspiratory effort. The aim of this study was to assess the EGJ activity during inspiratory maneuvers (high-resolution manometry, HRM) and the crural diaphragm (CD) thickness (endoscopic ultrasound, EUS) in GERD. Twenty esophagitis patients (average age 45years, 7 grade A, 13 grade B) had HRM and EUS. Forty-three controls were recruited; 30 had HRM (average age 33years), and 13 had EUS (average age 40years). The EGJ contractility index (EGJ-CI) (mm Hg×cm) was measured during normal respiration and two inspiratory maneuvers: without and with inspiratory loads of 12, 24, and 48cmH2 O (TH-maneuvers). A composite metric for TH-maneuvers ("EGJ total activity") was defined as the product of the maximal EGJ pressure and the length of its aboral excursion during the maneuver (mm Hg×cm). The CD thickness (cm) was measured during expiration (12MHz). Expiratory lower esophageal sphincter pressure and integrated relaxation pressure were lower in GERD. The EGJ-CI and the "EGJ total activity" were lower in GERD during TH-maneuvers (48-cmH2 O load: 168.4±13.8 vs 114.8±9.6, P=.006). Patients failed to sustain the inspiratory CD activity across the 12 and 48-cmH2 O efforts. The CD was thinner in GERD patients (0.37±0.03 vs 0.49±0.04, P=.02). The CD thickness correlated with the increment in the "EGJ total activity" in GERD without a hiatal hernia (r=.702, P=.016, n=11). There are anatomical changes and functional failure of the CD in esophagitis patients supporting the possibility of a skeletal muscle deficiency in GERD.

Abnormal thyroid hormones and non-thyroidal illness syndrome in obstructive sleep apnea, and effects of CPAP treatment

ObjectiveIn obstructive sleep apnea (OSA), while both hypothyroidism and hyperthyroidism have been studied, the occurrence of non-thyroidal illness syndrome (NTIS) (normal thyroid stimulating hormone [TSH] with low triiodotironine) has not been investigated. We explored the occurrence of NTIS in patients with moderate to severe OSA and its relationship to the severity of nocturnal respiratory disorders. We also studied the occurrence of subclinical hypothyroidism (SH, ie, high TSH with normal thyroxine) in OSA and changes in circulating TSH, free triiodotironine (fT3) and free thyroxine (fT4) after CPAP treatment. MethodsAfter a nocturnal respiratory polysomnography, 125 consecutive patients with moderate to severe OSA and 60 control subjects with normal nocturnal respiration were recruited. Morning circulating TSH, fT3, and fT4 were measured in all subjects. In a subsample of patients, nocturnal polysomnography and hormonal determinations were repeated after CPAP treatment for five months. ResultsNTIS was found in 13 (10.4%), and SH in ten (8%) OSA subjects, but not in any control subjects. Patients with NTIS showed worse mean nocturnal oxygen saturation and time with saturation <90% (both p < 0.001). After treatment, NTIS subjects (n = 13) showed an increase in fT3 (p < 0.001) to the normal range, and SH subjects (n = 6) a slight decrease in TSH (p = 0.01). In the patients with normal hormones before treatment (n = 45), no change was observed. ConclusionsNTIS may occur in OSA patients with severe nocturnal hypoxemia. OSA treatment is followed by an improvement in TSH in patients with abnormal baseline levels of this hormone, and by recovery of NTIS.

Females report higher postoperative pain scores than males after ankle surgery

ObjectivesThe majority of patients experience moderate-to-intense pain following ankle surgery. Early, adequate treatment of postoperative pain is desirable for optimal pain relief, which in turn may facilitate optimal pulmonary function, normal respiration pattern, rehabilitation and prevention of a chronic pain condition. In this retrospective study, we aimed to identify possible predictors of moderate-to-intense postoperative pain while in the Post Anaesthesia Care Unit (PACU) in patients operated for ankle fractures. Materials and methodsSocial demographics and clinical characteristics from admission throughout the stay in the PACU were collected from the hospital patient record system in retrospect. Pain was assessed using a Visual Analogue Scale (VAS) or a verbal Numeric Rating Scale (vNRS). A VAS/vNRS score 4–6 was classified as moderate and 7–10 as intense pain. Other factors which were investigated were time from ankle fracture to surgery, anaesthetic procedure, pre-, per- and postoperative medical treatment, radiological classification, complexity of fracture, operative technique, and time using tourniquet procedure. ResultsData from 336 patients who underwent surgery to repair an ankle fracture between January 2009 and December 2010 were analysed. None of the following variables had a statistically significant effect on pain; age, weight, smoking, timeframe from fracture to operation, type of anaesthesia, opioids given peroperatively, complexity of the fracture, operation technique or tourniquet inflation procedure. Female sex predicted moderate-to-intense postoperative pain in the PACU with odds ratio 2.31 (95% confidence interval 1.39–3.86), P=0.001. As far as we know, this is the first study to show a sex difference in reporting pain in the first hours after surgery for ankle fracture. ConclusionFemale patients operated for ankle fracture report higher pain-intensity-score than male patients while in the PACU. ImplicationsOur findings suggest that treatment strategies to prevent high peaks of pain should particularly target women operated for an ankle fracture.

Assessment of continuous acoustic respiratory rate monitoring as an addition to a pulse oximetry-based patient surveillance system.

Technology advances make it possible to consider continuous acoustic respiratory rate monitoring as an integral component of physiologic surveillance systems. This study explores technical and logistical aspects of augmenting pulse oximetry-based patient surveillance systems with continuous respiratory rate monitoring and offers some insight into the impact on patient deterioration detection that may result. Acoustic respiratory rate sensors were introduced to a general care pulse oximetry-based surveillance system with respiratory rate alarms deactivated. Simulation was used after 4324 patient days to determine appropriate alarm thresholds for respiratory rate, which were then activated. Data were collected for an additional 4382 patient days. Physiologic parameters, alarm data, sensor utilization and patient/staff feedback were collected throughout the study and analyzed. No notable technical or workflow issues were observed. Sensor utilization was 57%, with patient refusal leading reasons for nonuse (22.7%). With respiratory rate alarm thresholds set to 6 and 40breaths/min., the majority of nurse pager clinical notifications were triggered by low oxygen saturation values (43%), followed by low respiratory rate values (21%) and low pulse rate values (13%). Mean respiratory rate collected was 16.6±3.8breaths/min. The vast majority (82%) of low oxygen saturation states coincided with normal respiration rates of 12-20breaths/min. Continuous respiratory rate monitoring can be successfully added to a pulse oximetry-based surveillance system without significant technical, logistical or workflow issues and is moderately well-tolerated by patients. Respiratory rate sensor alarms did not significantly impact overall system alarm burden. Respiratory rate and oxygen saturation distributions suggest adding continuous respiratory rate monitoring to a pulse oximetry-based surveillance system may not significantly improve patient deterioration detection.

Rational Roots of Sympathetic Overactivity by Neurogenic Pulmonary Edema Modeling Arising from Sympathyco-Vagal Imbalance in Subarachnoid Hemorrhage: An Experimental Study

Autonomous innervations of the lungs are maintained by cervical sympathetic and vagal nerves. Sympathetic overactivity-induced neurogenic pulmonary edema (NPE) is known as a serious complication of subarachnoid hemorrhage, but the rational neuronal mechanism of that overactivity has not yet been clarified fully. The aim of this study was to examine whether there is a relationship between vagal nerve ischemia related sympathetic overactivity and neurogenic pulmonary edema in subarachnoid hemorrhage. This study was conducted on 27 rabbits. A control group was formed of 5 animals, a sham group of 7 to which saline was administered, and a study group of 15 animals that were injected with homologous arterial blood into the cisterna magna. Electrocardiography and respiratory rhythm parameters were monitored for 3 weeks and the animals were then decapitated. Statistical analysis was made of the numbers of degenerated axons in the pulmonary branches of the vagal nerves, the neuron density of stellate ganglions and the vasospasm index of the pulmonary arteries. In the control group, the normal respiration rate was 34 ± 6 bpm, total axon number was 1600 ± 270/mm(2), degenerated axon number was 10 ± 3/mm(2), and vasospasm index was 1.34 ± 0.25. The sham group values were 30 ± 3 bpm, 163 ± 47/mm(2), and 1.95 ± 0.45 and the study group values were 45 ± 8 bpm, 530 ± 92/mm(2), and 2.76 ± 0.83. The mean stellate ganglion neuron density was evaluated as 8.112 ± 1.230/mm(3) in all animals, as 7.420 ± 4.10/mm(3) in animals with slight NPE, and as 12.512 ± 1.236/mm(3) in animals that developed severe NPE. High neuron density of stellate ganglion may have important roots in sympathetic overactivity-related NPE development in subarachnoid hemorrhage.

Primate Diversity of the Nasal Conchae: Are there Functional Differences?

Despite their great importance in normal respiration, the nasal conchae have undergone a substantial amount of evolutionary change among the primates. With strepsirhines retaining a primitive condition of four to six ethmoturbinals situated in a committed recessus olfactorius, haplorhines have departed from this condition by expressing only one or two ethmoturbinals and lacking a transverse ethmoidal lamina that would otherwise separate respiratory and olfactory areas of the nose. Among the most derived of the haplorhines are humans, who have undergone a substantial restructuring of the facial skeleton and upper airway over the evolution of the genus Homo. Yet, even among humans, there is an impressive array of variation that may, at times, become of clinical importance. We assessed variability in the number of conchae among 16 human cadavers (nine females and seven males). It was found that all possessed a total of three nasal conchae but a great amount of diversity in the size and appearance of the ethmoturbinals was present. We found two cases of a bifid first ethmoturbinal, one case of concha bullosa, and one case of an extremely small second ethmoturbinal. The results indicate that, among humans, the inferior turbinate is far less variable in morphology than the ethmoturbinals. This is likely related to its role as the primary center for heat and moisture exchange during normal respiration. We posit that this is a functionally constrained structure that cannot accommodate as much morphological variation as the ethmoturbinals, which lie further from the areas of highest airflow velocity.

Use of a Vertical Expandable Prosthetic Titanium Rib in Children With Thoracic Insufficiency Syndrome and Scoliosis.

Thoracic insufficiency syndrome is the inability of the thorax to support normal respiration or lung growth. One treatment to address the thoracic deformities associated with the syndrome is placement of a vertical expandable prosthetic titanium rib. The goal is to restore thoracic volume, symmetry, and function and to allow for growth of the thorax in skeletally immature children. The main topics include indications for placement of a titanium rib, postoperative nursing care, potential complications, long-term follow-up, quality-of-life issues, and implications for critical care nurses and advanced practice nurses.

Scanning Electrochemical Microscopy Imaging during Respiratory Burst in Human Cell.

Phagocytic cells, such as neutrophils and monocytes, consume oxygen and generate reactive oxygen species (ROS) in response to external stimuli. Among the various ROS, the superoxide anion radical is known to be primarily produced by nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase. In the current study, we attempt to evaluate the respiratory burst by monitoring the rapid consumption of oxygen by using scanning electrochemical microscopy (SECM) imaging. The respiratory burst was measured in a human monocytic cell line (THP-1 cells) derived from an acute monocytic leukemia patient under the effect of the exogenous addition of phorbol 12-myristate 13-acetate, which acts as a differentiation inducer. SECM imaging composed of a microelectrode was used to compare oxygen consumption between normal cellular respiration and during respiratory burst in THP-1 cells. Two-dimensional respiratory activity imaging was performed using XY-scan. In addition, the quantitative evaluation of oxygen consumption in THP-1 cells was performed using a Z-scan. The results obtained show higher consumption of oxygen in cells undergoing respiratory burst. SECM imaging is thus claimed to be a highly sensitive and appropriate technique compared to other existing techniques available for evaluating oxidative stress in human cells, making it potentially useful for widespread applications in biomedical research and clinical trials.

Carbon stable isotopes as indicators of the origin and evolution of CO2 and CH4 in urban solid waste disposal sites and nearby areas

Isotopic compositions of CH4 and CO2 surface and subsurface gases and groundwater from an urban solid waste disposal site from Gualeguaychu city (Argentina) were measured to detect origin, depth distribution, migration lateral, CH4 oxidation, and dissolution in groundwater. The highest CH4 concentrations (60–88 %) with δ13C-CH4 (between −60 and −45 ‰) and δ2H-CH4 (between −350 and −260 ‰) were attributed to CH4 originated by microbial sources, v. gr. acetate fermentation. The δ13C-CO2 related to this CH4 (between −15 and −5.9 ‰) were compatible with this process. Also, the increase of DIC associated to an increase in δ13C-DIC values (−12.4, −6.4, −5.8, −1.5, +0.1 and +4 ‰) indicated the transport of dissolved gases (from methanogenesis) in the groundwater flow system. High excess deuterium in 3 piezometers suggests that there were hydrogen isotope exchange between CH4 and water too. Evidences for CH4 oxidation were decrease in CH4 concentrations, shift in C and H isotope ratios of CH4 to more enriched in the remaining CH4 (in both, δ13C-CH4 >−50 ‰ and δ2H >−260 ‰) and depletion in 13C of the associated CO2 (<−20 ‰). Since surface CH4 and CO2 concentrations over the covering layer were very low, and the major CH4 concentrations were found between 60m and 90 cm depth, it is very probable USW has been compacted with low permeability materials (e.g., clay) avoiding large emissions to the atmosphere and creating horizontal barriers within the waste that enable lateral gas migration. Horizontally, it can be seen that these gases migrated outside the disposal site following the topography and that CH4 disappeared leading to anomalous concentrations of CO2 whose values are greater than those produced by normal soil respiration. The isotopic value (δ13C) of this CO2 was also different from that of normal soil respiration (~−25 ‰) and reflected effects that generated isotopic depletion by diffusion (~−25 to −32 ‰). The analysis of C isotopes as the main tracer, together H isotopes, has allowed the effective detection of the origin and those secondary processes.