Two studies were carried out to test the hypothesis that the fall and recovery of nasal resistance after exercise in asthmatic and non-asthmatic subjects are related to the development of bronchoconstriction after exercise. In study 1 nasal resistance (posterior rhinomanometry) and specific airway resistance (sRaw) were measured before challenge and one, five, 10 and 30 minutes after four minutes of exhausting legwork exercise in nine asthmatic subjects and nine age matched healthy subjects. One minute after exercise there was a reduction in nasal resistance of 49% (SD 15%) from baseline in the healthy subjects and of 66% (17%) in the asthmatic subjects. This response and the subsequent return of nasal resistance to baseline values did not differ significantly between the two groups despite a substantial difference in the change in sRaw, an increase of 74% (45%) in the asthmatic subjects 10 minutes after exercise, and no change in the non-asthmatic subjects. In study 2, nasal and specific airway resistances were monitored according to the same measurement protocol in six subjects with increased airway reactivity. Subjects exercised on two occasions, wearing a noseclip, once while breathing cold, dry air and once while breathing warm, humid air. The fall in nasal resistance was similar under both conditions (to 47% and 39% of baseline), through sRaw rose only after cold air inhalation (to 172% of baseline). The results indicate that the nasal response to exercise is not related to bronchial obstruction in asthmatic subjects after exercise or to the temperature or humidity of the air inspired through the mouth during exercise.
Acoustic rhinometry is a new technique which evaluates nasal obstruction by analysing reflections of a sound pulse introduced via the nostrils. The technique is rapid, reproducible, non-invasive and requires minimal cooperation from the subject. Unlike rhinomanometry it does not require airflow. A graph of nasal cross-sectional area as a function of distance from the nostril is produced, from which several area and volume estimates of the nasal cavity can be derived. The reliability of the method is greatest in the anterior nasal cavity, which is the site of the nasal valve. We have applied the technique to the study of normal nasal physiology in adults and children and to a range of pathological conditions. The role of acoustic rhinometry in diagnosis is somewhat limited compared to nasal endoscopy, but it is useful for nasal challenge and for quantifying nasal obstruction. Monitoring of medical and surgical therapy is a more promising application. In future, acoustic rhinometry is likely to be of particular help in evaluating childhood nasal obstruction, as it is well tolerated by children as young as 3 years old-a group of patients to whom objective tests have hitherto been difficult to apply.
The nasal valve region plays a key role in nasal breathing. In the international literature, a variety of techniques have been described to rectify nasal valve compromise, but based on the present evidence it is impossible to counsel a patient as to which technique is most effective. The aim of this study was to evaluate the results of surgery of the nasal valve through a hemitransfixion incision objectively with nasal endoscopy and rhinomanometry. The study group consisted of 54 males and 15 females with a mean age of 41.8 ± 14.4 years, (range: 21-72 years). After a mean follow-up of 8 ± 4.1 months, nasal endoscopy demonstrated the favourable effects of surgical treatment with a normalization of the nasal valve angles. Only 5 patients showed persistent nasal valve stenosis, and were scheduled for revision surgery. Preoperatively, total decongested inspiratory NARs were 0.245 ± 0.091 Pa/cm3/s and decreased significantly after the operation (p < 0.0005) to 0.154 ± 0.059 Pa/cm3/s. Similarly, preoperatively total decongested expiratory NARs were 0.188 ± 0.068 Pa/cm3/s and decreased significantly after the operation (p < 0.0005) to 0.142 ± 0.059 Pa/cm3/s. Moreover, total dilated inspiratory and expiratory NARs resulted significantly (p < 0.0005) lower than the preoperatively total decongested NARs, with a mean value of 0.120 ± 0.059 Pa/cm3/s and 0.102 ± 0.057 Pa/cm3/s, respectively. Statistical analysis did not reveal any influence of sex and age in rhinomanometric measurements. Hemitransfixion incision allowed a wide access to the whole valve area for inspection and correction of the various components. Rhinomanometry, performed in a decongested condition and after dilation test, was thus a useful diagnostic tool for the preoperative diagnosis of nasal valve obstruction and permitted to assess quantitatively the favourable effect of surgical procedures.
Rhinoplasty; Nasal valve; Rhinomanometry
BACKGROUND--Although the nose and the bronchi are both involved in the process of regulating respiratory heat exchange, thermal changes may precipitate airway obstruction during exercise but rarely cause nasal obstruction in patients with rhinitis. The cause of the different response of the nose and bronchial tree has hardly been investigated. This study was performed to assess the response of the nose during exercise in the presence of rhinitis, asthma, and in normal controls. METHODS--Ten healthy subjects (group 1), 15 patients with asthma and rhinitis (group 2), 10 with rhinitis only (group 3), and 11 with asthma only (group 4) were included in the study. Exercise was performed on a bicycle ergometer for six minutes, reaching a heart rate of 80% of predicted. Bronchial and nasal responses were measured by forced expiratory volume in one second (FEV1) and posterior rhinomanometry, respectively. A drop in the FEV1 of 20% or more was considered a positive exercise induced asthma challenge test. RESULTS--Heart rate and ventilation increased by a similar proportion in the four groups. The FEV1 significantly decreased in asthmatic patients (groups 2 and 4) but it did not change in healthy subjects (group 1) or in those with rhinitis (group 3). Thirteen asthmatic patients developed exercise induced asthma. Nasal patency increased with exercise by a similar proportion in all groups, and no differences were detected between those with rhinitis (groups 2 and 3) and those without (groups 1 and 4). Nasal patency had returned to basal values at 25 minutes after completion of exercise in the four groups. The nose of patients with exercise induced asthma, however, remained significantly more patent than in patients without exercise induced asthma between 10 and 30 minutes after exercise. CONCLUSIONS--These results suggest that the nose responds differently from the bronchi during exercise induced airway obstruction: whereas the bronchial tree responds by becoming narrowed, the nose becomes more patent. These findings suggest that the mechanisms regulating the response of the nose to exercise are different from those involved in the response of the bronchial tree.
To study the relationship between oncogenesis by v-src and normal cellular signalling pathways, we determined the effects of v-src on 3T3-TNR9 cells, a Swiss 3T3 variant which does not respond mitogenically to tumor promoters such as 12-O-tetradecanoyl-phorbol-13-acetate (TPA). We found that src was unable to transform these variant cells, whether the oncogene was introduced by infection with a murine retrovirus vector or by transfection with plasmid DNA. 3T3-TNR9 cells were not inherently resistant to transformation, since infection with similar recombinant retroviruses containing either v-ras or v-abl did induce transformation. Further analysis of Swiss 3T3 and 3T3-TNR9 cell populations infected with the v-src-containing retrovirus revealed that although the amount of v-src DNA in each was approximately the same, the level of the v-src message and protein and the overall level of phosphotyrosine expressed in the infected variants was much less than in infected parental cells. Cotransfection experiments using separate v-src and neo plasmids revealed a decrease in the number of G418-resistant colonies when transfections of TNR9 cells occurred in the presence of the src-containing plasmid, suggesting a growth inhibitory effect of v-src on 3T3-TNR9 cells, as has also been found for TPA itself. Since v-src cannot transform this variant cell line, which does not respond mitogenically to the protein kinase C agonist TPA, we suggest that src makes use of the protein kinase C pathway as part of its signalling activities.
Nasal obstruction is a common symptom. Rhinomanometry is a tool to objectively assess the nasal airway. A prospective study was undertaken to assess the nasal airflow and nasal resistance in 25 patients of deviated nasal septum undergoing septoplasty using rhinomanometry preoperatively and postoperatively. Rhinomanometric improvement in nasal airflow and decreased nasal resistance were found in 88% patients after surgery.
Nasal obstruction; Rhinomanometry; Nas al resistance; Nasal airflow; Septoplasty
Adequate perception of nasal airflow (i.e., nasal patency) is an important consideration for patients with nasal sinus diseases. The perception of a lack of nasal patency becomes the primary symptom that drives these patients to seek medical treatment. However, clinical assessment of nasal patency remains a challenge because we lack objective measurements that correlate well with what patients perceive.The current study examined factors that may influence perceived patency, including air temperature, humidity, mucosal cooling, nasal resistance, and trigeminal sensitivity. Forty-four healthy subjects rated nasal patency while sampling air from three facial exposure boxes that were ventilated with untreated room air, cold air, and dry air, respectively. In all conditions, air temperature and relative humidity inside each box were recorded with sensors connected to a computer. Nasal resistance and minimum airway cross-sectional area (MCA) were measured using rhinomanometry and acoustic rhinometry, respectively. General trigeminal sensitivity was assessed through lateralization thresholds to butanol. No significant correlation was found between perceived patency and nasal resistance or MCA. In contrast, air temperature, humidity, and butanol threshold combined significantly contributed to the ratings of patency, with mucosal cooling (heat loss) being the most heavily weighted predictor. Air humidity significantly influences perceived patency, suggesting that mucosal cooling rather than air temperature alone provides the trigeminal sensation that results in perception of patency. The dynamic cooling between the airstream and the mucosal wall may be quantified experimentally or computationally and could potentially lead to a new clinical evaluation tool.
Obstructive sleep apnoea syndrome is a disease characterized by a collapse of the pharyngeal airway resulting in repeated episodes of airflow
cessation, oxygen desaturation, and sleep disruption. It is a common disorder affecting at least 2-4% of the adult population. The role
of nasal resistance in the pathogenesis of sleep disordered breathing and sleep apnoea has not been completely clarified. Aim of the present
study was to establish whether nasal resistance and nasal volumes, measured by means of Active Anterior Rhinomanometry and Acoustic
Rhinometry together with Muco-Ciliary Transport time play a positive predictive role in the evaluation of Obstructive sleep apnoea
syndrome patients before running a nocturnal polysomnographic recording. A retrospective study was performed analysing 223 patients
referred for suspected Obstructive sleep apnoea syndrome. All patients were submitted to complete otorhinolaryngological evaluation and
underwent nocturnal polysomnography. On the basis of polysomnographic data analysis, the apnoea-hypopnoea index and snoring index,
patients were classified into two groups: Group 1 (110/223 patients) with a diagnosis of mild-moderate Obstructive sleep apnoea syndrome
(apnoea-hypopnoea index < 30) and Group 2 (113/223 patients) affected by snoring without associated hypoxaemia/hypercapnia. A control
group of 76 subjects, not complaining of sleep disorders and free from nasal symptoms was also selected. The results showed, in all the
snoring and Obstructive sleep apnoea syndrome patients, total nasal resistance and increased Muco-Ciliary Transport time compared to
standard values. Furthermore, the apnoea-hypopnoea index was significantly higher in patients with higher nasal resistence and significantly
different between the groups. These results allow us to propose the simultaneous evaluation of nasal functions by Active Anterior
Rhinomanometry, Acoustic Rhinometry, and Muco-Ciliary Transport time in the selection of patients undergoing polysomnography.
Sleep respiratory disorders; Obstructive sleep apnoea syndrome; Nasal functionality tests; Polysomnography
The effect of aspirin on nasal resistance to airflow was investigated by rhinomanometry in 25 healthy subjects before and after ingestion of aspirin or vitamin C in a double blind crossover trial. Aspirin caused a significant increase in nasal resistance compared with vitamin C. The effect of aspirin may be due to its inhibition of the synthesis of prostaglandins.
The normal values for lung resistance and lung capacity of children, as determined by impulse oscillometry (IOS), are different for children of different ethnicities. However, reference values there is no available reference value for Korean preschool children have yet to be determined. The aim of the present study was to determine the normal ranges of IOS parameters in Korean preschool children.
A total of 133 healthy Korean preschool children were selected from 639 children (aged 3 to 6 years) who attended kindergarten in Seongnam, Gyeonggi province, Korea. Healthy children were defined according to the European Respiratory Society (ERS) criteria. All subjects underwent lung function tests using IOS. The relationships between IOS value (respiratory resistance (Rrs) and reactance (Xrs) at 5 and 10 Hz and resonance frequency (RF)) and age, height, and weight were analyzed by simple linear and multiple linear regression analyses.
The IOS success rate was 89.5%, yielding data on 119 children. Linear regression identified height as the best predictor of Rrs and Xrs. Using stepwise multiple linear regressions based on age, height, and weight, we determined regression equations and coefficients of determination (R2) for boys (Rrs5=1.934-0.009×Height, R2=12.1%; Xrs5=0.774+0.006×Height-0.002×Age, R2=20.2% and for girls (Rrs5=2.201-0.012×Height, R2=18.2%; Xrs5=-0.674+0.004×Height, R2=10.5%).
This study provides reference values for IOS measurements of normal Korean preschool children. These provide a basis for the diagnosis and monitoring of preschool children with a variety of respiratory diseases.
Impulse oscillation system; Reference values; Airway resistance; Preschool children
Cephalometric analysis is essential for planning treatment in maxillofacial and aesthetic facial surgery. Although photometric analysis of the Korean nose has been attempted in the past, anthropometry of the deeper nasal structures in the same population based on computerized tomography (CT) has not been published. We therefore measured three anthropometric parameters of the nose on CT scans in our clinical series of patients.
We conducted the current retrospective study of a total of 100 patients (n=100) who underwent a CT-guided radiological measurement at our institution during a period ranging from January of 2008 to August of 2010. In these patients, we took three anthropometric measurements: the nasofrontal angle, the pyramidal angle, and the linear distance between the nasion and the tip of the nasal bone.
The mean nasofrontal angle was 131.14° in the male patients and 140.70° in the female patients. The mean linear distance between the nasion and the tip of the nasal bone was 21.28 mm and 18.02 mm, respectively. The mean nasal pyramidal angle was 112.89° and 103.25° at the level of the nasal root, 117.49° and 115.60° at the middle level of the nasal bone, and 127.99° and 125.04° at the level of the tip of the nasal bone, respectively.
In conclusion, our data will be helpful in the preparation of silicone implants for augmentation and/or corrective rhinoplasty in ethnic Korean people.
Anthropometry; Nose; Rhinoplasty; Korea
OBJECTIVE: To study the relation between exposure and nasal function in woodwork teachers. METHODS: 39 selected woodwork teachers employed full time and 32 control subjects (other school personnel) were examined at the beginning and at the end of a working week with symptom rating, nose and throat inspection, rhinomanometry, nasal mucociliary clearance test, and a smell identification test. During one working day of the same week climate, dust and terpene concentrations were measured in all 39 schools. RESULTS: The ventilation rate was highest in rooms with mechanical ventilation. Range of total dust (personally sampled) was 0.12-1.18 mg/m3, respirable dust 0.02-0.21 mg/m3, and terpenes (area sampled) 0.02-6.8 mg/m3. In contrast to the control subjects, the woodwork teachers had more nasal symptoms on the Thursday afternoon than on the Monday morning, especially those working in rooms without mechanical ventilation. Their mucociliary clearance worsened during the week (mean increase 4 min, P < 0.001). A small impairment of olfactory function was also found, but their rhinomanometric values did not change significantly. Nasal symptoms correlated weakly with the percentage of respirable dust in the total dust. Otherwise there were no significant dose-effect relations between measured dust or terpene concentrations and nasal tests. CONCLUSIONS: The woodwork teachers had mainly reversible nasal complaints, impaired nasal mucociliary clearance and olfactory function related to the work environment, with dust concentrations below the Swedish threshold limit value of 2 mg/m3.
We prepared an allergen challenge chamber (ACC) which facilitates quantitative pollen challenge at any time, and, so, the acquisition of objective data. The aim of this study was to evaluate peak nasal inspiratory flow rate (PIFR) as an endpoint during allergen challenge and compare this with rhinomanometry (Rhino) and acoustic rhinometry (AR).
The study was conducted in November, which is not in pollen season. Subjects were exposed to Japanese cedar pollen at a concentration of 50,000 counts/m3in ACC for 120 minutes each day for 2 days. Subject recorded nasal symptoms before challenge and every 15 minutes after challenge initiation. Nasal symptoms (sneezing frequency, nasal blowing frequency, nasal obstruction) were recorded before challenge and every 15 minutes after challenge initiation. For the evaluation of nasal obstruction, we used visual analog scales (VASs); subjects marked a site on a 10-cm line corresponding to the symptom severity on which absence of symptoms was designated as 0 and worst imaginable symptom as 10. PIFR was measured using an In-check flow meter and nasal resistance was measured using Rhino. The cross-sectional area in the nasal cavity was also measured using AR before and after challenge as an indicator of nasal obstruction.
When the volunteers with cedar pollinosis were exposed to cedar pollen in ACC, pollinosis symptoms were induced significantly. Changes in the 3 symptoms (sneezing frequency, nose-blowing frequency, nasal obstruction) were investigated before and after challenges on 2 consecutive days. No significant symptoms were induced on the first day of challenge in the non-pollen season. However, each of the 3 symptoms became more severe with second day of challenge, and a significant increase was seen in cumulative values by the second day. In terms of the allergen challenge test, we found a significant correlation between nasal obstruction symptom (VAS) and PIFR, but not AR and Rhino.
PIFR after allergen challenge is more sensitive than AR or Rhino in detecting nasal obstruction using the allergen challenge chamber.
Several ultramicroscopic studies have confirmed the presence of biofilms in ENT diseases, such as chronic rhinosinusitis, nasal polyposis or adenoid hypertrophy. Recently, it has been reported that light microscopy nasal cytology can identify biofilms, which appear as cyan-stained “Infectious Spots.”
Subjects suffering from a wide spectrum of nasal disorders, after a detailed clinical history and ENT examination, underwent nasal fibroendoscopy, skin prick test, rhinomanometry and nasal cytology.
1410 subjects were studied. The infectious spot was present in 107 of them (7.6%) patients; this percentage reached 55.4% in 193 patients who had clear cytologic signs of infectious rhinitis. Biofilms were largely more frequent in patients with adenoid hypertrophy (57.4%), followed by nasal polyposis (24%), chronic rhinosinusitis (9.5%) and non-allergic “cellular” rhinitis (7.6%). Nasal cytology was normal in the remaining patients, with no infectous spot detectable. Statistical analysis showed that nasal resistances were significantly higher in presence of biofilms in patients affected by adenoid hypertrophy (P = 0.003), nasal polyposis (P < 0.001), chronic rhinosinusitis (P = 0.018) and septal deviation (P = 0.001).
The results demonstrate that biofilms are not present only in infectious rhinopathies, but also in inflammatory and/or immune-mediateddiseases. Biofilms were more frequent in patients with higher degree of nasal obstruction as assessed by nasal endoscopy (grade III and IV adenoids and stage-3 polyposis) and rhinomanometry. Nasal cytology, by allowing the identification of biofilms represents a useful diagnostic tool with promising research implications.
During the past decades, numerous computational fluid dynamics (CFD) studies, constructed from CT or MRI images, have simulated human nasal models. As compared to rhinomanometry and acoustic rhinometry, which provide quantitative information only of nasal airflow, resistance, and cross sectional areas, CFD enables additional measurements of airflow passing through the nasal cavity that help visualize the physiologic impact of alterations in intranasal structures. Therefore, it becomes possible to quantitatively measure, and visually appreciate, the airflow pattern (laminar or turbulent), velocity, pressure, wall shear stress, particle deposition, and temperature changes at different flow rates, in different parts of the nasal cavity. The effects of both existing anatomical factors, as well as post-operative changes, can be assessed. With recent improvements in CFD technology and computing power, there is a promising future for CFD to become a useful tool in planning, predicting, and evaluating outcomes of nasal surgery. This review discusses the possibilities and potential impacts, as well as technical limitations, of using CFD simulation to better understand nasal airflow physiology.
Computational fluid dynamics; Nose models; Nasal airflow dynamics; Airflow physiology and pathophysiology
Our investigation aimed to visualize the 3-D spatial distribution of nasal cavity mucosal swelling under levocetirizine prophylactic treatment on exposure to allergens. This study made use of standard rhinologic diagnostics such as rhinomanometry and acoustic rhinometry, as well as 24 hours rhinometry and magnetic resonance imaging (MRI).
A suitable test subject with a history of allergic rhinitis was identified during the symptom-free interval after the pollen season when she showed signs of “minimal persistent inflammation,” consisting of pronounced reaction to nasal challenge with allergens. Provocation with birch pollen caused moderate symptoms of allergic rhinitis. Nasal provocation tests were performed before and after 2 and 5 weeks of treatment with levocetirizine 5 mg OD. Long-term rhinometry was carried out to detect the progress of the nasal cycle and relative flow variances over 24 hours. Flexible air tubes required for this new procedure made it possible to quantify relative pressure changes. High resolution MRI was also used to capture, visualize, and process the geometrical data of the nasal cavity immediately before and after the challenge tests. Based upon the MRI data, we computed the nasal airflow using a computational fluid dynamics (CFD) nasal model to visualize intranasal pressure and flow. Rhinomanometry and acoustic rhinometry were performed to validate the results.
After 36 days of treatment with levocetirizine, a 16% improvement in the nasal flow relative to baseline and an increase by 3.4 cm3 of the total nasal baseline volume were documented as compared to the allergen challenge of the untreated case. 3-D images illustrated that treatment inhibited the allergen provocation effects on nasal airflow and normalised nasal flow velocity and pressure, including in the olfactory region.
Besides improving the nasal airflow to an almost normal pattern, levocetirizine also helps prevents the patient from having an allergic response, even 24 hours after last drug intake. Furthermore, it can improve olfaction by restoring airflow to the olfactory region.
Nasal and sinusal complaints are considered common among swimmers. Aim of the present study was to evaluate the nasal and bronchial functions, before and after swimming, and the relationship between nasal resistances and FEV1 in competitive swimmers. A group of 30 competitive swimmers were examined: spirometry and nasal respiratory tests were carried out before and after swimming. Moreover, both the competitive swimmers and the 150 visitors of a swimming pool were asked to complete a specific questionnaire. In this questionnaire, 18% of the population reported nasal-sinusal symptoms after swimming. The differences between nasal volumes and resistances before and after swimming were not statistically significant. Nasal patency increased or remained unchanged in 21/30 athletes. The variations in FEV1 were not statistically significant. In conclusion, results showed that swimming is able to increase nasal patency or to leave it unchanged. Temporary worsening of the nasal patency was observed in only a few hyper-reactive patients. In the whole group, no variations, at bronchial level, were found.
Nose; Nasal physiology; Swimming pool; Chlorine
This study tested the hypotheses that the hypertonic environment of the renal medulla regulates the expression of cystic fibrosis transmembrane conductance regulator protein (CFTR) and its natural splice variant, TNR-CFTR. To accomplish this, Madin- Darby canine kidney (MDCK) stable cell lines expressing TNR-CFTR or CFTR were used. The cells were treated with hypertonic medium made with either NaCl or urea or sucrose (480 mOsm/kg or 560 mOsm/kg) to mimic the tonicity of the renal medulla environment. Western blot data showed that CFTR and TNR-CFTR total cell protein is increased by hypertonic medium, but using the surface biotinylation technique, only CFTR was found to be increased in cell plasma membrane. Confocal microscopy showed TNR-CFTR localization primarily at the endoplasmic reticulum and plasma membrane. In conclusion, CFTR and TNR-CFTR have different patterns of distribution in MDCK cells and they are modulated by a hypertonic environment, suggesting their physiological importance in renal medulla.
CFTR; TNR-CFTR; Sodium chloride; Urea Sucrose; MDCK cells; Hypertonic environment Plasma membrane
Measuring grip and pinch strength is an important part of hand injury evaluation. Currently, there are no standardized values of normal grip and pinch strength among the Korean population, and lack of such data prevents objective evaluation of post-surgical recovery in strength. This study was designed to establish the normal values of grip and pinch strength among the healthy Korean population and to identify any dependent variables affecting grip and pinch strength.
A cross-sectional study was carried out. The inclusion criterion was being a healthy Korean person without a previous history of hand trauma. The grip strength was measured using a Jamar dynamometer. Pulp and key pinch strength were measured with a hydraulic pinch gauge. Intra-individual and inter-individual variations in these variables were analyzed in a standardized statistical manner.
There were a total of 336 healthy participants between 13 and 77 years of age. As would be expected in any given population, the mean grip and pinch strength was greater in the right hand than the left. Male participants (137) showed mean strengths greater than female participants (199) when adjusted for age. Among the male participants, anthropometric variables correlated positively with grip strength, but no such correlations were identifiable in female participants in a statistically significant way.
Objective measurements of hand strength are an important component of hand injury evaluation, and population-specific normative data are essential for clinical and research purposes. This study reports updated normative hand strengths of the South Korean population in the 21st century.
Hand strength; Pinch strength; Muscle dynamometer; Korean population; Demographic transition
Methylenetetrahydrofolate reductase (MTHFR) is the main regulatory enzyme for homocysteine metabolism. In the present study, we evaluated whether the MTHFR 677C>T and 1298A>C gene polymorphisms are associated with SBI and plasma homocysteine concentration in a Korean population.
Materials and Methods
We enrolled 264 patients with SBI and 234 healthy controls in South Korea. Fasting plasma total homocysteine (tHcy) concentrations were measured, and genotype analysis of the MTHFR gene was carried out.
The plasma tHcy levels were significantly higher in patients with SBI than in healthy controls. Despite a significant association between the MTHFR 677TT genotype and hyperhomocysteinemia, the MTHFR 677C>T genotypes did not appear to influence susceptibility to SBI. However, odds ratios of the 1298AC and 1298AC + CC genotypes for the 1298AA genotype were significantly different between SBI patients and normal controls. The frequencies of 677C-1298A and 677C-1298C haplotypes were significantly higher in the SBI group than in the control group.
This study demonstrates that the MTHFR 1298A>C polymorphism is a risk factor for SBI in a Korean population. The genotypes of 677C>T and 1298A>C polymorphisms interact additively, and increase the risk of SBI in Korean subjects.
Methylenetetrahydrofolate reductase; polymorphism; haplotype; silent brain infarction
Background and aim: Peak Nasal Inspiratory Flow Rate (PNIFR) is a clinical trial that has been instituted in clinical practice in order to determine the extent of nasal airway patency and it is used to assess the degree of nasal obstruction. This study attempts to provide tables referring to normal values of PNIFR in children and adolescents.
Patients and Methods: Three thousand one hundred and seventy pupils aged between 5 – 18 years, were selected to enter the study. Children with acute or chronic upper airway obstruction, such as acute obstructive pulmonary disease or allergic rhinitis and children below the 3rd percentile for weight and/or height were excluded from the study. All children that took part in the study were subjected to PNIFR measurements by using a portable Youlten Peak Flow meter.
Results: A continuous increase of PNIFR values for boys and girls in relation to age increase was recorded. PNIFR values were higher in boys compared to girls and this difference was statistically significant until the age of 12.
Conclusion: Normal ranges for PNIFR standards are of great importance for the study of nasal patency, evaluation of the degree of nasal obstruction and application of treatment. This is the first time that a detailed description of PNIFR standards becomes available for the Greek population of children and adolescents.
nasal inspiratory flow rate; normal values; children; adolescents
The feedback-inhibited form of Bacillus subtilis glutamine synthetase regulates the activity of the TnrA transcription factor through a protein-protein interaction that prevents TnrA from binding to DNA. Five mutants containing feedback-resistant glutamine synthetases (E65G, S66P, M68I, H195Y, and P318S) were isolated by screening for colonies capable of cross-feeding Gln− cells. In vitro enzymatic assays revealed that the mutant enzymes had increased resistance to inhibition by glutamine, AMP, and methionine sulfoximine. The mutant proteins had a variety of enzymatic alterations that included changes in the levels of enzymatic activity and in substrate Km values. Constitutive expression of TnrA- and GlnR-regulated genes was seen in all five mutants. In gel mobility shift assays, the E65G and S66P enzymes were unable to inhibit TnrA DNA binding, while the other three mutant proteins (M68I, H195Y, and P318S) showed partial inhibition of TnrA DNA binding. A homology model of B. subtilis glutamine synthetase revealed that the five mutated amino acid residues are located in the enzyme active site. These observations are consistent with the hypothesis that glutamine and AMP bind at the active site to bring about feedback inhibition of glutamine synthetase.
Nasal bone assessment has been incorporated into Down syndrome screening in first trimester. Several studies have established the normal reference values for fetal nasal bone length in the first trimester, which were found to be varied by population. However, the study on reliability of nasal bone length measurement was limited with contradictory results. This study aimed to investigate the reliability of fetal nasal bone length measurement at 11–14 weeks of gestation in the Thai population.
A total of 111 pregnant women at 11–14 weeks of gestation attending for the routine first-trimester ultrasound examination were recruited. Each case was measured separately by two examiners. Examiner 1 performed the first measurement in all cases; any of the other 5 examiners consecutively performed the second measurement. Three independent measurements were performed by each examiner and they were blinded to the results of the others. Intraobserver and interobserver variabilities were evaluated with the intraclass correlation coefficient (ICC).
Nasal bone measurement was successfully performed in 106/111 cases (95.5%) by at least one examiner; 89 cases were performed by two examiners. The intraobserver variability was excellent for all examiners (ICC, 0.840-0.939). The interobserver variability between different pairs of examiners varied from moderate to excellent (ICC, 0.467-0.962). The interobserver variability between examiner 1 and any other examiner was good (ICC, 0.749). The Bland-Altman plot of the interobserver differences of nasal bone length measurements between examiner 1 and any other examiner showed good agreement.
The reliability of the fetal nasal bone length measurement at 11–14 weeks of gestation was good. The nasal bone length measurement was reproducible. Ethnicity has an effect on fetal nasal bone length, but reliability of nasal bone length measurement is critical to accuracy of screening and should be audited on an ongoing basis.
Ultrasound; Fetal nasal bone; First trimester; Reliability; Reproducibility
Acoustic rhinometry is a rapid, reliable and non-invasive technique for the evaluation of conditions associated with impaired nasal patency. This study aimed to examine the intersession repeatability of acoustic rhinometry measurements of unilateral and combined nasal parameters in a group of healthy volunteers.
Twenty healthy volunteers were studied. In each subject, acoustic rhinometry measurements were performed on five consecutive days, with multiple recordings. Five clinically relevant parameters were measured in each session and the intersession repeatability of these measurements was expressed in terms of mean coefficient of variation, intraclass correlation coefficient and inter-item correlations.
Intraclass correlation coefficients showed a high, and greater repeatability over time for all the combined (mean) values compared to the unilateral values. All intraclass correlations for combined values were ≥0.80 confirming almost perfect agreement. All intraclass correlations and inter-item correlations were associated with P<0.001. The mean coefficient of variation was low (<10%) for all but the proximal minimum cross sectional area (MCA1) measurements.
Acoustic rhinometry provides highly repeatable measurements of nasal patency, which is best for combined (mean) nasal parameters. This property makes it suitable for use in the diagnosis and follow-up of conditions associated with nasal obstruction, either structural or functional.
Acoustic rhinometry; Reproducibility of results; Nasal obstruction
BACKGROUND--A study was undertaken to determine if cephalometric radiographs could identify those who will benefit from nasal surgery in patients with a sleep apnoea hypopnoea syndrome (SAHS) and chronic nasal obstruction. METHODS--Fourteen patients with SAHS were enrolled. Those with normal posterior airway space and mandibular plane to hyoid bone distances on preoperative cephalometric radiographs were matched with those with abnormal cephalometry for the frequency of sleep disordered breathing and body mass index. Polysomnographic studies (all subjects) and nasal resistance measurements (n = 10) were performed one to three months before and two to three months after surgery (septoplasty, turbinectomy, and polypectomy). RESULTS--There was no difference in the baseline results of the polysomnographic studies between the two groups of patients. Nasal resistance decreased from a mean (SE) value of 2.9 (0.3) cm H2O/l/s before surgery to 1.4 (0.1) cm H2O/l/s after surgery in the normal cephalometry group and from 2.7 (0.3) cm H2O/l/s to 1.3 (0.3) cm H2O/l/s in the other group. The apnoea + hypopnoea index returned to normal (< 10 breathing abnormalities/hour) in all but one subject with normal cephalometric measurements, and sleep fragmentation improved with a decrease in the arousal index from 23.9 (3.3)/hour at baseline to 10.6 (2.5)/hour after surgery. Both of these parameters remained unchanged after surgery in the patients with abnormal cephalometry. CONCLUSIONS--Normal cephalometry is helpful in identifying patients with mild SAHS and nasal obstruction who will benefit from nasal surgery. The presence of craniomandibular abnormalities makes it unlikely that nasal surgery will improve sleep related breathing abnormalities.