Objetivo: Determinar os valores normativos da área de secção transversa mínima nasofaríngea de indivíduos sem anomalias craniofaciais e em diferentes faixas etárias. Método: Participaram do estudo 96 indivíduos sem anomalias craniofaciais, de ambos os sexos, subdivididos em 4 grupos etários: crianças com idade entre 6 e 10 anos (G1), adolescentes de 11 a 17 anos (G2), adultos jovens entre 18 e 39 anos (G3) e adultos de meia-idade entre 40 e 59 anos (G4). Verificou-se o índice de massa corpórea (IMC), a partir das medidas de peso e altura, e a circunferência cervical (CC), por meio de fita métrica pediátrica. A área de secção transversa mínima nasofaríngea (área nasofaríngea ANF) foi determinada por meio de rinomanometria anterior modificada (técnica fluxo-pressão), utilizando o sistema PERCI-SARS (versão 3.50 Microtronics Corp.). A significância da diferença entre as médias dos quatro grupos etários foi verificada por meio do teste Kruskal-Wallis, para amostras não pareadas. A correlação entre ANF e IMC, e ANF e CC, em cada grupo estudado, foi verificada por meio do coeficiente de correlação de Spearman. Foram aceitos como significantes os valores de p<0,05. Resultados: Todos os indivíduos apresentaram IMC indicativo de peso normal, exceto um único adulto jovem que apresentou índice de sobrepeso. A CC média de mulheres e homens adultos (G3 e G4) apresentou-se dentro da normalidade, sugerindo ausência de risco para obesidade. Os valores médios±DP da ANF foram de 1,025±0,054cm2, 1,055±0,081cm2, 1,050±0,083cm2 e 1,054±0,081cm2, respectivamente, para G1, G2, G3 e G4, não havendo diferença entre as 4 faixas etárias. Não houve correlação entre a ANF e o IMC e a ANF e a CC, em nenhum dos grupos estudados. Conclusão: Os valores normativos de ANF foram determinados para indivíduos sem anomalias craniofaciais de diferentes faixas etarias e servirão como referência em estudos envolvendo obstrução nasofaríngea. / Objective: To establish normative values of minimum cross-sectional nasopharyngeal area in individuals without craniofacial anomalies at different age ranges. Method: Ninety-six individuals of both genders, without craniofacial anomalies were evaluated. Participants were divided into 4 age groups: children, aged 6 to 10 years (G1); adolescents, aged 11 to 17 years (G2); young adults, 18 to 39 years (G3) and middle-aged adults, 40 to 59 years (G4). The body mass index (BMI) was calculated based on weight and height, and neck circumference (NC) was measured with a pediatric measuring tape. Minimum cross-sectional nasopharyngeal area (nasopharyngeal area NPA) was assessed by means of modified anterior rhinomanometry (pressure-flow technique) using a PERCI-SARS system (version 3.50 Microtronics Corp.). The difference between the mean values of the 4 age groups were verified by the Kruskal-Wallis test, for unpaired samples. Correlations between NPA and BMI, and NPA and NC were verified for each group by the Spearmans correlation coefficient. Differences were analyzed at a significance level of 5%. Results: All individuals presented normal BMI, except one young adult, which presented BMI suggestive of overweight. Mean NC values from adult women and men (G3 and G4) were within the normal range, suggesting no risk for obesity. Mean±SD values of NPA were 1.025±0.054cm2, 1.055±0.081cm2, 1.050±0.083cm2 and 1.054±0.081cm2 respectively, for groups G1, G2, G3 and G4, showing that there were no differences between the four age ranges. There was no correlation between NPA and BMI, and NPA and NC, in none of the studied groups. Conclusion: Normative data of NPA were established for individuals without craniofacial anomalies from different age ranges and may be used as reference values for future studies concerning nasopharyngeal obstruction.

Abstract Maintenance of the mitochondrial respiratory chain complexes plays crucial role for the aerobic metabolism of the eukaryotes such as unicellular yeasts, for example, Saccharomyces cerevisiae as well as of human being. Mitochondrial respiratory function has been studied using the yeast S. cerevisiae as a model organism. Since yeast cells are also able to grow without respiration by fermentation, identification of the nuclear genes linked to respiratory function is possible by generation of nuclear gene deletions and testing for respiration-deficient phenotype of the yeast deletion strains id est for yeast cells only poorly or not at all growing on the media containing non-fermentable carbon sources. This study reports identification of a novel mitochondrial 2-enoyl thioester reductase from the yeasts Candida tropicalis and S. cerevisiae, Etr1p and Mrf1p, respectively. Examination of the function of these proteins in the respiration-deficient mrf1Δ strain from S. cerevisiae suggests that the reductase is involved in mitochondrial fatty acid synthesis (FAS type II) in the yeast. Site-directed mutagenesis of a conserved tyrosine in the catalytic site of the enzyme indicated that the 2-enoyl thioester reductase activity is critical for mitochondrial respiratory competence. In addition, subcellular localization to mitochondria was required for the complementation of the respiration-deficient phenotype of the yeast reductase deletion strain. The crystal structure for the Etr catalytic site mutant indicated the structural integrity of the mutant supporting the requirement of the tyrosine for the catalysis. Characterization of Etr crystal structures both in apo- and holo-forms containing NADPH established Etr as a member of novel subfamily of enoyl thioester reductases in the superfamily of medium-chain dehydrogenases/reductases (MDR). Two isoforms of Etr with the difference in three amino acids only are encoded by two distinct genes in C. tropicalis, whereas only single gene encodes the reductase functioning in the mitochondria in S. cerevisiae. The presence of two genes in C. tropicalis was taken as an example of genetic redundancy in this yeast, the two genes also shown to be expressed in slightly different ways under various carbon sources available for growth.

No description available.

Background: Patients with chronic neck pain have a number of factors that could constitute a predisposition for respiratory dysfunction. However, the existing evidence is limited and not well established, and many questions such as the association of neck pain deficits with respiratory function remain unanswered. Thus, the aim of this study was to investigate whether patients with chronic neck have accompanying respiratory dysfunction and which are the neck pain deficits which principally predispose to these respiratory disturbances.Methods: In this case-control observational study, 45 patients with chronic idiopathic neck pain (>6 months, at least once per week) and 45 healthy age-, gender-, height- and weight-matched controls were voluntarily recruited. A third group of 10 patients with chronic non-spinal musculoskeletal pain was also used, but only for future reference. Participants' neck muscle strength and endurance were measured by an isometric neck dynamometer and craniocervical flexion test respectively. Range of movement was assessed by using an ultrasound-based motion analysis system. Forward head posture was assessed by obtaining lateral photographs and calculating the craniovertebral angle. Disability and neck pain intensity were assessed through the Neck Disability Index and Visual Analogue Scale. Psychological assessment was performed by using the Hospital Anxiety and Depression Scale, the Pain Catastrophizing Scale and the Tampa Scale for Kinesiophobia. Spirometry was used for assessing pulmonary volumes, flows and maximal voluntary ventilation. Respiratory muscle strength was assessed by using a mouth pressure meter. Finally, PaCO2 was assessed by using transcutaneous blood gas monitoring.Results: Patients with chronic neck pain were found to have weaker respiratory muscles than healthy controls (p<0.05). Their pulmonary volumes and maximal voluntary ventilation were also found to be reduced (p<0.05). Their mean respiratory flows were found to be unaffected (p>0.05), whereas their peak flows were reduced (p<0.05). Their partial pressure of carbon dioxide was also found to be affected (p<0.05), revealing existence of hypocapnia (PaCO2<35mmHg). The neck pain deficits that were found to be mostly correlated with these respiratory parameters were the neck muscle strength, neck muscle endurance, kinesiophobia, catastrophizing and pain intensity (r>0.3, p<0.05). Finally, the regression models revealed that neck pain deficits and especially neck muscle strength can provide a quite generalizable accurate estimation of this respiratory dysfunction (R2=0.28-0.52).Conclusions: Patients with chronic neck pain present dysfunction of their respiratory system which can be mainly manifested as respiratory weakness and/or hypocapnia. Pain intensity, neck muscle weakness, fatigue and kinesiophobia seem to be the most important deficits predisposing to this respiratory dysfunction. The understanding of this dysfunction could have a great impact on various clinical aspects notably patient assessment, rehabilitation and drug prescription. However, further research is suggested mainly directed towards optimizing treatment protocols and developing classification systems improving clinical reasoning.

By superimposing an artificial water flow over the gills out of phase with the natural breathing movements of the fish, it has been possible to demonstrate that bradycardia and cardiorespiratory synchrony develop in response to decreased peripheral oxygen levels. Further evidence that peripheral and not central receptors are involved was furnished by injecting deoxygenated blood into the dorsal aorta; no effect on heart rate or breathing was observed. Bradycardia still develops in response to hypoxia at the respiratory surface even during the absence of branchial blood flow demonstrating that the circulatory system is not involved in this reflex. Numerous tastebud-like receptors have been found lining the anterior faces of the gill bars. These are innervated by the branchial branches of the vagus nerve. Stimulation of the cut central ends of these nerves results in responses similar to those obtained when environmental oxygen levels are decreased. It is suggested that these tastebud-like organs are the receptors and that the branchial branches of the vagus nerve form one afferent pathway for reflex bradycardia and cardiorespiratory synchrony. Other possible afferent pathways are suggested and the functional significance of the reflex is discussed. / Science, Faculty of / Zoology, Department of / Graduate

Birds are a diverse group of vertebrates, with over 10,000 extant species. Diversification into volant, aquatic and terrestrial environmental niches has precipitated a remarkable morphological diversity between species. Birds have a unique respiratory system consisting of a rigid lung connected to an air sac system. Air is pumped into the respiratory system via movements of the ribcage and sternum. Previous research identified the uncinate processes, ossified projections extending from the vertebral ribs, as critical respiratory and locomotor structures. Uncinate processes facilitate inspiration and expiration through associated muscles that displace the ribs and therefore sternum. External intercostal muscles project from the processes and function during locomotion to stabilise body roll. Therefore uncinate processes provide a link between breathing and locomotion in birds. The objective of my PhD is to extend beyond this basic research on uncinate processes to investigate how diversity in avian body morphology relates to the fundamental functions of breathing and locomotion.While the function of uncinate processes in respiration has been identified, the mechanism whereby ventilatory movements are elicited is not known. Therefore I present a model that demonstrates how respiratory movements of the skeleton are facilitated by the lever action of uncinate processes. Furthermore, variation in process and sternal morphology is driven by adaptation to different forms of locomotion. Therefore fundamental differences in breathing mechanics may be associated with specialisation to locomotor behaviour. Detailed developmental studies of the uncinate processes in birds are almost nonexistent. I provide the first detailed description of developmental changes in the uncinate processes in the turkey. Ossification of the uncinate processes begins around the time of hatch. However, the base is cartilaginous upon hatching and so the lever action of the processes may be compromised in the chick. I provide further evidence for a functional link between process length and respiratory physiology, since elongated processes support an elevated resting metabolic rate in birds. This link was further explored in physiological experiments where the energetic cost of walking in the barnacle goose was manipulated by load carrying. Carrying extra mass on the sternum is more energetically costly than an equivalent back load indicating that the cost of breathing increased. A directly proportional relationship exists between increasing mass of back load and metabolic rate, while sternal loads were approximately twice as expensive to carry during locomotion. Leg loads incurred the greatest increase in metabolism. Finally, I demonstrate how uncinate processes functioned as respiratory structures in basal avian species and a theropod ancestor of modern birds. Development of the uncinate processes may have been an important step in the evolution of the avian lung - air sac system.The principal findings of the five first author research articles presented in this PhD thesis shed important new light on the ventilatory mechanics in birds and highlight interactions between breathing and locomotion. Diversity in avian body morphology driven by adaptation to various locomotor behaviours has resulted in modification of the respiratory system.

Arterial desaturation in fit athletes, during exercise at an intensity greater than or equal to 90% of VO₂ max has been reported by a number of authors yet the etiology of these changes remain obscure. Inadequate pulmonary ventilation due to a blunted respiratory drive, or lung mechanics has been implicated as a factor in the etiology of this phenomenon. It was the purpose of this experiment to investigate the relationship between arterial desaturation and ventilatory response to hypoxia (HVR). Twelve healthy male subjects ( age = 23.8 ± 3.6 yrs., height = 181.6 ±₋₁ 5.6 cms., Weight = 73.7 ± 6.2 kg., VO₂ max = 63.2 ± 2.2 ml .kg . -1 2 .min⁻¹) performed a five minute exercise test on a treadmill at 100% of VO₂ max. Arterial samples for pH, PCO₂, PO₂, and SaO₂ were withdrawn via an indwelling arterial cannula at rest and every 15s throughout the exercise test. The blood gas samples were analyzed with an Instrument Laboratories 1306 blood gas analyzer. Ventilation and VO₂ were measured by a Beckman metabolic measurement cart. On a separate occasion the ventilatory response to hypoxia (HVR) was determined by recording VE as progressive hypoxia was induced by adding N₂ to a mixing chamber. SaO₂ was measured using a Hewlett-Packard ear oximeter; to maintain isocapnia small ammounts of CO₂ were added to the open circuit system. ANOVA for repeated measured was used to evaluate changes in blood gases, ventilation, and VO₂. Simple linear regression and multiple linear regression was used to evaluate the relationship between the changes in SaO₂ and HVR and the descriptive variables. Subjects showed a significant decline in arterial saturation and PO₂ over the course of the test (p < 0.01,and p < 0.01). Four subjects (Mild) exhibited modest decreases in SaO₂ to (94.6 ± 1.9%), three (Moderate) showed an intermediate response (SaO₂ 91.6 ± 0.1%) and five (Marked) demonstrated a marked decrease in arterial saturation (SaO₂ = 90.0 + 1.2%). The differences in PO₂ and SaO₂ between Mild and Marked groups were significant ( p < 0.05, and p < 0.01); there were no significant differences between groups in VE, VO₂, pH or PCO . There was no significant correlation between the lowest SaO₂ reached and HVR, or any of the descriptive variables. Nine subjects did not reach maximal VE (as determined by the VO₂ max test) on the exercise test, two subjects 2 exhibited similar ventilation, and the remaining subject exceeded maximal VE, but fell into the Mild group with respect to desaturation. Oxygen uptake exceeded that recorded for the VO₂ max determination for four of the five subjects in the Marked group; the remaining subjects demonstrated lower or similar values. It was concluded that arterial desaturation was not related to blunted hypoxic drive. / Education, Faculty of / Curriculum and Pedagogy (EDCP), Department of / Graduate

M.Tech. / Low-intensity laser irradiation (LILI), also known as photo-biostimulation, is a type of phototherapy which is based on the application of low power monochromatic and coherent light mostly in the wavelength range of 600 to 1 000 nm to injuries and lesions to stimulate healing. LILI has been shown to increase adenosine triphosphate (ATP) synthesis, cell proliferation (Silveira et al., 2007 and 2009; Hawkins and Abrahamse, 2006a) and collagen synthesis, and release of growth factors from cells (Eells et al., 2004). LILI has not been fully embraced and is mainly due to the fact that the biochemical mechanisms underlying the positive effects are not completely understood (Hamblin and Demidova, 2006). Though the mechanisms of photo-biostimulation on a variety of mitochondrial enzymes have been proposed and studied by different researchers, most of the mechanisms are based on oxygen consumption studies and lack direct experimental support (Chen et al., 2008). This project was designed to study the enzyme activity and expression of the mitochondrial respiratory chain complexes (I to V) post-irradiation with a wavelength of 660 nm and a fluence of 5 or 15 J/cm2 in isolated human skin fibroblast cells. Diabetes mellitus (DM) is a group of diseases marked by high levels of blood glucose resulting from defects in insulin production, insulin action or both. It is found worldwide and is estimated to affect 1.1% of the world population (World Health Organization, WHO, 2002). Estimates from 2009 by the International Diabetes Federation suggest that the number of adults with diabetes in the world will expand by 54%, from 284.6 million in 2010 to 438.4 million in 2030. The projected growth for sub-Saharan Africa is 98%, from 12.1 million in 2010 to 23.9 million in 2030 (Mbanya et al., 2010). Though DM is more common in industrialized countries, the trend is changing.

Breathing is an essential homeostatic function and its disruption leads to disability, brain damage, and death. Serotonin (5-hydroxytryptamine; 5-HT) neurons in the brainstem play an important role in control of breathing. Medullary 5-HT neurons are stimulated by increased CO₂ and subsequently stimulate respiratory nuclei to increase ventilation and maintain normal blood gas levels. Anesthetic-induced breathing dysfunction is a serious concern in healthcare settings. In research settings, experiments are often performed under anesthesia, and therefore it is important to understand how these drugs affect animal physiology. Unfortunately, little is known about how anesthetics modulate 5-HT neurons, breathing, and CO₂ chemoreception in mice, as many of the previous studies have been performed in different species. Characterizing how anesthetics commonly used in both research and clinical settings affect 5-HT neurons, breathing and CO₂ chemoreception is valuable to the broader field of neuroscience since these drugs are so ubiquitously used in research. Breathing dysfunction and defects in the serotonergic system have been implicated in disorders, such as sudden unexpected death in epilepsy (SUDEP) and sudden infant death syndrome (SIDS), which means better characterizing the role of 5-HT neurons in breathing has translational impact as well. Here I examine whether halogenated inhalational anesthetics, which potentiate TWIK-related acid-sensitive K⁺ (TASK) currents and GABAA receptors, could mask an effect of CO₂ on 5-HT neurons. During in vivo plethysmography in mice, a therapeutic level of isoflurane (1%) markedly reduced the hypercapnic ventilatory response (HCVR) in all mouse strains tested. In dissociated cell cultures, isoflurane (1%) hyperpolarized 5-HT neurons and inhibited spontaneous firing. A subsequent decrease in pH from 7.4 to 7.2 depolarized 5-HT neurons, but that was insufficient to reach threshold for firing. Depolarizing current restored baseline firing and the firing frequency response to acidosis, indicating that isoflurane did not block the underlying mechanisms mediating chemosensitivity. These results demonstrate that isoflurane masks 5-HT neuron chemosensitivity in vitro, and markedly decreases the HCVR in vivo. Next, I demonstrate that ketamine-xylazine or urethane anesthesia also significantly reduced the HCVR in mice at both therapeutic and sub-therapeutic doses. However, mice treated with a sub-therapeutic dose of anesthesia decreased their O₂ consumption in parallel, and thus matched their ventilation to metabolic demands. Mice that were anesthetized with the therapeutic dose did not sufficiently match their breathing and metabolic demands, and thus anesthesia induced hypoventilation. Recordings from 5-HT neurons in culture indicated that neither ketamine nor urethane affected 5-HT neuron chemosensitivity. These data demonstrate that anesthetics with different molecular targets similarly reduce the HCVR in mice, but not all of their effects are mediated via 5-HT neurons. Moreover, both ketamine-xylazine and urethane anesthesia altered baseline breathing in different ways, suggesting they targeted different parts of the respiratory network. Finally I show that isoflurane anesthesia in neonatal mice caused depression of resting ventilation, which was different from isoflurane-anesthetized adults. This effect was more pronounced in wildtype mice compared to littermates with genetic deletion of 5-HT neurons. Isoflurane-induced breathing depression decreased and mice fully recovered following washout of isoflurane at P8. I observed that genetic deletion of 5-HT neurons in mice with a congenic C57Bl/6 background led to a more severe phenotype than previously described in mixed genetic background strains. These mice had decreased survival, severe growth retardation, and reduced baseline ventilation. These results indicate that 5-HT neurons have a different role during the neonatal period and that some mouse strains are more sensitive to genetic deletion of 5-HT neurons; thus, background genetics play an important role in phenotype presentation. In summary, different classes of anesthetics each strongly depress chemoreception. Isoflurane seems to affect breathing, in part, by hyperpolarizing 5-HT neurons and masking their chemosensitivity, whereas ketamine and urethane have less effect on 5-HT neurons. However, both ketamine-xylazine and urethane anesthesia alter baseline breathing. Isoflurane anesthesia decreases baseline ventilation in neonates, but this effect is absent in adults, which suggests that the effects of isoflurane on breathing changes as mice age. These data are important for the field of respiratory physiology because they highlight the sensitivity of breathing to the effects of anesthetics. These results are valuable to the broader field of neuroscience, because anesthetics are widely used during in vivo research. Additionally, some transgenic mouse strains are more sensitive to 5-HT neuron deletion depending on their genetic background. In the future it will be critical to characterize the molecular mechanisms that underlie these phenomena.

Coastal nutrient loading is a growing concern in urbanized communities and has led to alterations in above- and belowground processes throughout estuarine systems. Mangrove forests are highly productive coastal habitats that exhibit large carbon stocks contained mostly to the deep soils. Since nutrient enrichment has been found to increase mangrove aboveground growth, it’s presumed that nutrient enrichment will also increase belowground respiration rates. Disturbances in soil nutrient content may alter the mangrove carbon cycle by increasing the amount of CO2 lost to the atmosphere from enhanced microbial and root respiration. In this study, soil respiration responded greatest to nitrogen enrichment, but pneumatophore root respiration responded greatest to phosphorus enrichment. Nutrient limitation can shift between different ecological processes and responses to nutrient enrichment tend to be system specific in tidally influenced ecosystems. Understanding the implications of coastal nutrient loading will improve ecosystem models of carbon exchange and belowground processes. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection