Aerodynamics of Sneezing

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SummaryThere are similarities between allergic rhinitis (AR) and atopic bronchial asthma in their pathophysiology, although some differences also exist. For example, some AR patients without asthma demonstrate airway hyperresponsiveness (AHR) of the lower respiratory tract. Similar findings have been noted in patients with atopic dermatitis. This indicates that a systemic sensitization to antigen itself plays a pivotal role in the induction of AHR in sensitized individuals independently of eosinophilic inflammation in the lower airway. To clarify the mechanism, we studied a mouse model and found that transfer of antigen‐induced memory/effector cells can induce AHR in normal mice without airway inflammation. Dendritic cells (DCs) play a critical role in antigen‐induced immune response. We investigated the role of cysteinyl leukotrienes (cysLTs) in DC functions. BALB/c mice were sensitized with ovalbumin (OVA) and aluminium hydroxide (alum) twice, and subjected to OVA inhalation to induce airway inflammation. Systemic OVA sensitization alone up‐regulated cysLTs in the lung and stimulated T‐helper type 2 (Th2) cytokines production, whereas leukotriene receptor antagonist (LTRA) suppressed these productions. OVA sensitization enhanced DC functions such as antigen‐presenting capacity and cytokine production, and LTRA also attenuated them. Finally, we treated mice with LTRA during systemic sensitization and examined the effect on subsequent airway inflammation induced by OVA inhalation. LTRA suppressed all indicators of inflammation such as airway eosinophilia, Th2‐type cytokine production, and AHR along with decreased DC functions of the lung. These results indicate that modulating the antigen‐induced up‐regulation of DC functions in the early phase could attenuate further development of eosinophilic inflammation in the lower airway. Taking the similarities of lower and nasal airway into account, cysLTs may also play a critical role in the pathogenesis of AR; therefore, LTRA could be effective against AR from the initial presentation to the inflammation phase.

Veins were considered merely as passive conduits of blood until Mellander ([13][1]) reported that stimulation of sympathetic nerves supplying the cat's hindquarters resulted in a decrease in regional blood volume. This and other work led Folkow and Mellander ([4][2]) to assert that veins were “at

Recently, many questions have been presented on the air streams in the nasal cavity, including the many unknown about the air stream in the paranasal sinus, the postoperative nasal cavity and the regenerated paranasal sinus. This thesis treated the route of the air st- reams through the direct observation on corpses. 1. The route of the air streams in the nasal cavity. 2. The route of the air streams in the para-nasal sinus. 3. The route of the air streams in the post-operative nasal cavity and the regener-ated paranasal sinus. a) The air streams in the postoperative nasal cavity. b) The air streams in the regenerated para nasal sinuses at the five weeks after combined sinectomy. At breathing in normal case of the nasal cavi- ty and the paranasal sinus, air runs out of the paranasal sinus during expiratory phase. At transitive phase it pours suddenly, and then gradually through inspiratory phase. Also, in the case of the postoperative regenerated para- nasal sinus, air stream takes the regular route ac- cording to the nasal forms. This thesis was to study the model form of the sinus of wound, which was united by the combined ethmoidectomy and maxillotomy several weeks before, and to treat the complex air route arised between sinus of wound and the nasal ca- vity through opened way to medius meatus and inferior meatus window.

Membrane potential changes in vocal cord tensor motoneurons during breathing, vocalization, coughing and swallowing in decerebrate cats.

The study proposes a digital stethoscope to assist physicians who are not respiratory specialists to diagnose specific diseases from lung sounds in local areas which lacks specialists and advanced medical equipment. The digital stethoscope presents a spectrogram of the auscultatory sound that illustrates changes in its feature values to visually present the area where the abnormal sound occurs. It not only assists non-specialist physicians in diagnosis but also provides easier explanations for patients. Accurate auscultation requires specialized knowledge and experience. Non-specialist physicians have difficulty distinguishing the characteristics of abnormal sounds among lung sounds which include a wide variety of sounds. Even if they find an abnormal sound suspected to be a disease, physicians will provide patients with only oral diagnosis explanations which would prevent patients from understanding their conditions in depth. The proposed method converts lung sound data collected by a digital stethoscope into a visual spectrogram showing the frequency features. The method uses the short-time Fourier transform as a method to extract the frequency features of lung sounds for each short segment in the whole time series of the lung sound. The converted spectrogram is used to detect disease-specific abnormal sounds comprehensively. The degree of abnormal sounds that appears in the inspiratory and expiratory phases varies with disease progression. The proposed method identifies abnormal sounds in the inspiratory and expiratory phases. Based on the inspiratory and expiratory phases recorded in the diagnostic by specialists, the method derives whether the abnormal sound occurs in each phase. It enables the method to detect specific respiratory diseases along with the degree of their progression. Furthermore, it also allows the method to visually present the location of detected abnormal sounds to patients. This paper uses a short-time Fourier transform as a method for extracting frequency features of lung sounds in a certain range. It also shows that feature extraction as a spectrogram that emphasizes the low frequency band, which is the human audible range, is effective in assisting the non-specialist physician in diagnosis. This paper prepares experimental data from real diagnoses so that data noise and disease features can be taken into account. The diagnostic accuracy is evaluated with a method of segmenting spectrogram images to extract frequency features at specific times. The method constructs a model for detecting fine crackles using the machine learning algorithm Decision Tree. The experimental results have shown that the accuracy of detecting fine crackles is 0.89. The high accuracy obtained from this model allows us to confirm the effectiveness of the proposed method for supporting for non-specialist physicians to distinguish abnormal sounds. The successful detection of fine crackles in the expiratory or inspiratory phase suggests that the progression degree of the disease could be estimated with the proposed digital stethoscope. The digital stethoscope will make it possible to accurately diagnose respiratory diseases along with a comprehensive explanation of diagnosis results to patients in areas with poor medical facilities. It also provides non-specialists with dependable diagnostic aid.

The role of the dorsolateral pons in the control of expiratory duration (Te) and breathing frequency is incompletely understood. A subregion of the pontine parabrachial-Kölliker-Fuse (PB-KF) complex of dogs was identified via microinjections, in which localized pharmacologically induced increases in neuronal activity produced increases in breathing rate while decreases in neuronal activity produced decreases in breathing rate. This subregion is also very sensitive to local and systemic opioids. The purpose of this study was to precisely characterize the relationship between the PB-KF subregion pattern of altered neuronal activity and the control of respiratory phase timing as well as the time course of the phrenic nerve activity/neurogram (PNG). Pulse train electrical stimulation patterns synchronized with the onset of the expiratory (E) and/or phrenic inspiratory (I) phase were delivered via a small concentric bipolar electrode while the PNG was recorded in decerebrate, vagotomized dogs. Step frequency patterns during the E phase produced a marked frequency-dependent decrease in Te, while similar step inputs during the I phase increased inspiratory duration (Ti) by 14 ± 3%. Delayed pulse trains were capable of pacing the breathing rate by terminating the E phase and also of triggering a consistent stereotypical inspiratory PNG pattern, even when evoked during apnea. This property suggests that the I-phase pattern generator functions in a monostable circuit mode with a stable E phase and a transient I phase. Thus the I-pattern generator must contain neurons with nonlinear pacemaker-like properties, which allow the network to rapidly obtain a full on-state followed by relatively slow inactivation. The activated network can be further modulated and supplies excitatory drive to the neurons involved with pattern generation.NEW & NOTEWORTHY A circumscribed subregion of the pontine medial parabrachial nucleus plays a key role in the control of breathing frequency primarily via changes in expiratory duration. Excitation of this subregion triggers the onset of the inspiratory phase, resulting in a stereotypical ramplike phrenic activity pattern independent of time within the expiratory phase. The ability to pace the I-burst rate suggests that the in vivo I-pattern generating network must contain functioning pacemaker neurons.

This review discussed the contribution of eosinophilic upper airway inflammation includes allergic rhinitis (AR) and chronic rhinosinusitis (CRS) to the pathophysiology and course of asthma, the representative counterpart in the lower airway. The presence of concomitant AR can affect the severity of asthma in patients who have both diseases; however, it is still debatable whether the presence of asthma affects the severity of AR. Hypersensitivity, obstruction and/or inflammation in the lower airway can be detected in patients with AR without awareness or diagnosis of asthma, and AR is known as a risk factor for the new onset of wheeze and asthma both in children and adults. Allergen immunotherapy, pharmacotherapy and surgery for AR can contribute to asthma control; however, a clear preventive effect on the new onset of asthma has been demonstrated only for immunotherapy. Pathological similarities such as epithelial shedding are also seen between asthma and CRS, especially eosinophilic CRS. Abnormal sinus findings on computed tomography are seen in the majority of asthmatic patients, and asthmatic patients with CRS show a significant impairment in Quality of Life (QOL) and pulmonary function as compared to those without CRS. Conversely, lower airway inflammation and dysfunction are seen in non-asthmatic patients with CRS. Treatments for CRS that include pharmacotherapy such as anti-leukotrienes, surgery, and aspirin desensitization show a beneficial effect on concomitant asthma. Acting as a gatekeeper of the united airways, the control of inflammation in the nose is crucial for improvement of the QOL of patients with co-existing AR/CRS and asthma.

Coughing maneuvers and forced expirations were observed in seven laryngectomized patients. Flow (V), air actually respired through the tracheostoma (VATPS), volume change of the body rlethysmograph (VB0X) and intraesophageal pressure (P) were simultaneously recorded.A paroxysm of a normal cough is divided into the inspiratory, minimum flow and expiratory phases. A coughing maneuver of the laryngectomized is lacking in the minimum flow phase. This is the most apparent and conclusive characteristic since the “tussive squeeze, ” a drainage mechanism of coughing, for the considerable part occurs in the minimum flow phase. Their intrathorathorcic airway compressions do not always accelerate the linear velocity of the expiratory air. In addition to the absence of protective upper airways in laryngectomized patiets, inefficient coughs are also related with latent or manifest existence of chronic obstructive pulmonary diseases. An efficient cough for them seems to be a preceding big inspiration immediately followed by successive several bursts with mild expiratory efforts.

Although allergic rhinitis and asthma have been assessed and treated as separate diseases, they often occur together. The connection between asthma and rhinitis is not a new discovery. This association has been recognized since earlier times. In the second century, Galen hypothesized that sinonasal disease caused lung disease through a direct anatomic connection. But, the nature of the link between the nose and the lung has been poorly understood until recent years (McFadden, 1986). Because the prevalence rates of rhinitis and asthma, as with all allergic diseases, are increasing worldwide, there is a growing interest in the interaction between upper and lower airways (Bousquet et al.,ARIA Workshop Group. World Health Organization, 2001). Allergic rhinitis (AR) is the most common atopic disease all over the world affecting almost 10% to 30% of population (Berger, 2003; Settipane, 2003). Although it generally is not considered a severe disorder, the socioeconomic costs of AR are substantial . It adversely affects quality of life of the patients, work productivity and school performance as well as increasing health care costs (Bachert et al., 2002; Meltzer et al., 2004). Patients who have asthma and rhinitis tend to have more severe disease with higher treatment costs. Treatment of rhinitis may improve asthma control, and early treatment of allergies may prevent the development of asthma (Marple, 2010). The connection between upper and lower airways has become a topic of great interest over the past few decades. It is now well established that rhinitis and asthma frequently co-exist, with approximately 20-50% of AR patients have concomitant asthma and over the 80% of asthmatics have nasal symptoms (Bousquet et al., 2003; Braunstahl & Fokkens, 2003). During this time of period, a body of evidence concerning the relationship between allergic rhinitis and asthma lead to the concept of unified airways or “one airway one disease”. Recent advances in the understanding and knowledge of the underlying mechanisms has been integrated into the “Allergic rhinitis and its impact on asthma” international report (Bousquet et al., ARIA Workshop, 2001). This document have been provided an comprehensive overview of current knowledge on allergic rhinitis and asthma, and evidence-based guidelines for the treatment. Neverthless not all patients with rhinitis present with asthma, the reason why are unknown. The “united airway disease” hypothesis proposes that upper and lower airway disease are both manifestations of a single inflammatory process of entire respiratory tract (Togias, 2003).

Allergic rhinitis and asthma are common chronic airway diseases that present significant public health challenges. Previous research has shown how the nasal and oral mycobiomes influence the onset, progression and severity of these two conditions, but no study so far has directly compared those mycobiomes within the same cohort during health and disease. To address this gap, I analyzed next-generation fungal ITS sequence data from 349 participants, including individuals with allergic rhinitis, asthma, and healthy controls. The nasal and oral mycobiomes showed a great overlap in composition but differed significantly (p < 0.04) in the relative abundance of several dominant genera. Moreover, only 18.6% of the fungal amplicon variants were shared among cavities. Microbial alpha-diversity was significantly higher (p < 0.05) in the nasal cavity, while beta-diversity varied significantly (p < 0.045) across all indices and clinical groups. Fungal networks were largely fragmented and showed relatively low ecological niche specialization, which contrasts with a previous study of bacteriomes from the same cohort. These networks also differed in structure, complexity and keystone nodes across clinical phenotypes. Overall, these findings highlight that the nasal and oral mycobiomes play distinct yet interconnected roles in allergic rhinitis and asthma.

Measurement of nitric oxide (NO) levels in exhaled air from the upper and lower airways is currently used as a non-invasive marker of inflammation in respiratory diseases. Assessment of NO exhaled from the lower air respiratory tract is considered to be a quick method for confirmation and control of asthma in patients as well as an estimation of treatment efficiency. The main aim of this study was to determine differences between levels of exhaled nitric oxide (fractional exhaled NO; FeNO) in patients with respiratory disease as measured by an electrochemical analyzer. Measurements were taken in 352 pediatric patients aged 4–17 with cystic fibrosis (CF) (n = 43), asthma (n = 69), allergic rhinitis (AR) (n = 70), asthma and AR (n = 128) and non-diseased children (n = 42) recruited from the Allergology Outpatient Department, Provincial Hospital No 2, Rzeszów. The second objective of this study was to assess any correlations between FeNO and clinical parameters of patients. The level of FeNO in patients with CF was normal when compared with control subjects (10.8 ± 2.9 versus 11.4 ± 6 ppb). We found significantly higher FeNO in patients with asthma (26.6 ± 15.3 ppb, p < 0.001), AR (18.4 ± 9.6 ppb, p < 0.01) as well as in patients with both asthma and AR (43.3 ± 31.1 ppb, p < 0.001) when compared to healthy children. Statistical analysis revealed a positive correlation between FeNO and age, height and weight of control subjects, and height in children with AR. FeNO was independent of sex, BMI, spirometry and blood results as well as the type of residence in control children and subjects with CF, asthma, AR and combined asthma and AR. In conclusion, we found normal levels of FeNO in children with CF and elevated levels in patients with asthma, AR and combined asthma and AR as compared to control subjects. Due to conflicting data, there is still a need for additional research, especially related to regarding factors that affect FeNO levels in respiratory disease.

D1-dopamine receptor blockade slows respiratory rhythm and enhances opioid-mediated depression

The objective of the present work was to develop new computational parameters to examine the characteristics of respiratory cycle phases from the tracheal breathing sound signal during sleep. Tracheal sound data from 14 patients (10 males and 4 females) were examined. From each patient, a 10 min long section of normal and a 10 min section of flow-limited breathing during sleep were analysed. The computationally determined proportional durations of the respiratory phases were first investigated. Moreover, the phase durations and breathing sound amplitude levels were used to calculate the area under the breathing sound envelope signal during inspiration and expiration phases. An inspiratory sound index was then developed to provide the percentage of this type of area during the inspiratory phase with respect to the combined area of inspiratory and expiratory phases. The proportional duration of the inspiratory phase showed statistically significantly higher values during flow-limited breathing than during normal breathing and inspiratory pause displayed an opposite difference. The inspiratory sound index showed statistically significantly higher values during flow-limited breathing than during normal breathing. The presented novel computational parameters could contribute to the examination of sleep-disordered breathing or as a screening tool.

Indacaterol and tiotropium combination therapy in patients with chronic obstructive pulmonary disease