Disability,depression and somatization in a low back pain population

Objective: The aim of this study was to determine the prevalence of low back pain (LBP) in a primary care setting population and examine its association with the symptoms of depression and somatization. Methods: This is a cross‐sectional study, utilising a survey carried out in primary health care clinics (PHCs) in Al‐Ain, United Arab Emirates (UAE). A multistage stratified sampling design was used and a representative sample of 1304 UAE nationals aged 18–65 years who attended PHC clinics for any reason were included and 1103 (84.5%) subjects agreed to participate and responded to the questionnaire during a period from June 2001 to January 2002. A specially designed questionnaire with three parts was used for the data collection: socio‐demographic information of the studied subjects, modified version of the Roland‐Morris scale for evaluating back‐related functional disability and SCL‐90 R for depression and somatization subscales was used to assess depressive and somatic symptoms. Results: Of the total number of subjects surveyed (1103), 586 (53.1%) were men and 517 (46.9%) women. The mean age was 34.9 ± 13.4 years for men and 33.5 ± 11.8 years for women. The prevalence of LBP in the studied subjects was 64.7% (95% CI, 60.7–68.5] with 46.7% among men and 53.3% among women. There were a significant differences between the subjects with LBP and without LBP with respect to gender (P < 0.001), body mass index (BMI) (P < 0.001), occupational status (P < 0.001) and living environment (P = 0.016). Functional disability was higher in patients with LBP. Young patients in aged 15–34 years, patients with preparatory/secondary educational level and students showed higher depressive symptoms. A similar pattern was found in patients with somatic symptoms. Factor analysis revealed a strong association between depression and somatization in LBP patients. Conclusions: Functional disability was higher in with LBP. Furthermore, symptoms of depression and somatization are prevalent among LBP patients.     

Physiological consequences of a high work of breathing during heavy exercise in humans

The healthy respiratory system has a remarkable capacity for meeting the metabolic demands placed upon it during strenuous exercise. For example, in order to regulate alveolar partial pressure of oxygen and carbon dioxide during heavy workloads, a 20-fold increase in alveolar ventilation can occur. The high metabolic costs and subsequent increased work of breathing associated with this ventilatory increase can result in a number of limitations to the healthy respiratory system. Two examples of respiratory system limitations that are associated with a high work of breathing are expiratory flow limitation and exercise-induced diaphragmatic fatigue. Expiratory flow limitation can lead to an inability to increase alveolar ventilation () in the face of increasing metabolic demands, resulting in gas exchange impairment and diminished endurance exercise performance. Furthermore, the high ventilatory requirements of endurance athletes and the inherent anatomical differences in females could make these groups more susceptible to expiratory flow limitation. Fatigue of the diaphragm has also been documented after strenuous exercise and may be related to a mechanism which increases sympathetic vasoconstrictor outflow and reduces limb blood flow during prolonged exercise. This competition between the muscles of respiration and locomotion for a limited cardiac output may have dramatic consequences for exercise performance. This brief review summarizes the literature as it pertains to the work of breathing, expiratory flow limitation, and exercise-induced diaphragmatic fatigue in healthy humans.     

Bradykinin-induced release of thromboxane B2 into bronchoalveolar lavage fluid of guinea pigs: relationship to airflow obstruction

The aim of this study was to evaluate the role of thromboxane A₂ in bradykinin-induced airflow obstruction in guinea pig in vivo. Airway insufflation pressure (P_i) was measured to assess airflow obstruction and the thromboxane B₂ (a stable metabolite of thromboxane A₂) concentration in bronchoalvelolar lavage fluid was determined by radioimmunoassay. The animals were pretreated with propranolol (1 mg/kg i.v.) and suxamethonium (5 mg i.v.) prior to bradykinin administration. Bradykinin instillation into the trachea (300 nmol) induced a P_i increase (47.5 ± 8.3 cm H₂O versus 23.8 ± 1.5 in sham) and significant thromboxane B₂ release into bronchoalveolar lavage fluid (79 ± 19 pg/ml versus 19 ± 6 in sham). A thromboxane synthase inhibitor (OKY-046, 30 mg/kg i.v.; ((E-E)-3-[p(1H-imidazole-1-yl-methyl) phenyl]-2-propenoic acid hydrochloride mono-hydrate)) or a thromboxane A₂ receptor antagonist (ICI192,605, 0.5 mg/kg i.v.; (4-(Z)-6-(2-o-chloro-phenyl-4-o-hydroxyphenyl-1,3-dioxan-cis-5-yl)hexenoic acid)) reduced the P_i increase evoked by bradykinin (38.7 ± 3.8 and 40.6 ± 3.8 cm H₂O, respectively). OKY-046 abolished the thromboxane B₂ release. A platelet-activating factor receptor antagonist, WEB2086 (1 mg/kg i.v.; (3-[4-(chlorophenyl)-9-methyl-6H-thienol [3,2-f][1,2,4]trizolo-[4,3-a][1,4] diazepin-2-yl]1-4-(4-morpholinyl)-1-propanon) did not significantly affect any measured parameter. We conclude that, in guinea pigs, bradykinin-induced airway effects are associated with a local thromboxane A₂ release.     

A Dynamic Morphometric Model of the Normal Lung for Studying Expiratory Flow Limitation in Mechanical Ventilation

A nonlinear dynamic morphometric model of breathing mechanics during artificial ventilation is described. On the basis of the Weibel symmetrical representation of the tracheobronchial tree, the model accurately accounts for the geometrical and mechanical characteristics of the conductive zone and packs the respiratory zone into a viscoelastic Voigt body. The model also accounts for the main mechanisms limiting expiratory flow (wave speed limitation and viscous flow limitation), in order to reproduce satisfactorily, under dynamic conditions, the expiratory flow limitation phenomenon occurring in normal subjects when the difference between alveolar pressure and tracheal pressure (driving pressure) is high. Several expirations characterized by different levels of driving pressure are simulated and expiratory flow limitation is detected by plotting the isovolume pressure–flow curves. The model is used to study the time course of resistance and total cross-sectional area as well as the ratio of fluid velocity to wave speed (speed index), in conductive airway generations. The results highlight that the coupling between dissipative pressure losses and airway compliance leads to onset of expiratory flow limitation in normal lungs when driving pressure is increased significantly by applying a subatmospheric pressure to the outlet of the ventilator expiratory channel; wave speed limitation becomes predominant at still higher driving pressures.     

Etiology of individual differences in reading performance: A test of sex limitation

To test the hypothesis that the etiology of individual differences in reading performance differs in males and females, reading performance data from twin pairs tested in the Colorado Learning Disabilities Research Center were fitted to structural equation models of sex limitation. The sample included 513 pairs of twins in which at least one member of each pair has a positive school history of reading problems [228 monozygotic (MZ), 176 same-sex dizygotic (DZ), and 109 opposite-sex DZ pairs] and 302 matched control pairs [148 MZ, 98 same-sex DZ, and 56 opposite-sex DZ pairs]. Estimates of the genetic correlation between performance in males and females were obtained by analysis of data from both same-sex and opposite-sex twin pairs (Neale and Cardon, 1992). The full model fit the data well ²=17,74, df=16,p=0.340), and the resulting genetic parameter estimates were highly similar in males and females in both the proband and the control samples. The correlations between genetic influences in males and females do not differ among groups (change in ²=0.95, df=1,p0.25), and the resulting pooled estimate is about .5. Thus, results of this analysis suggest that the etiology of individual differences in reading performance may differ to some extent in males and females.     

声反射技术在测量正常人咽腔中的应用

目的 探讨正常人咽腔大小与阻塞性睡眠呼吸暂停病人发病机理的相互关系。方法 用声反射测量技术对24名健康志愿者的咽腔进行测量,咽腔面积测量是测量持续的缓慢呼气终末的肺总容量(Total Lung Capacity,TLC)和残余量(Residual Volume,RV),比较咽腔横断面积在男女成人肺容量的三个方面的表现:TLC,50％VC(50％ of vital Capacity)和RV。结果 男性咽腔面积在TLC6.4±1.3cm2,在50％VC5.4±0.9cm2和RV4.1±0.8cm2。女性咽腔面积在TLC4.8±0.6cm2,50％VC4.2±0.5cm2和RV3.7±0.6cm2。男女间不同的咽腔面积在TLC和50％VC中有显著的统计学意义,而在RV中无统计学意义。结论 (1)不同性别的咽腔面积与身体的尺寸大小有关。(2)在男女成人中显示咽腔面积随着肺容量的变化有相似的变化。(3)男性成人的咽腔面积随着年龄的增长而减小。     

醋酸亮丙瑞林注射液的高效液相色谱分析

目的　建立醋酸亮丙瑞林注射液中亮丙瑞林及杂质的测定方法。方法　采用高效液相色谱法。色谱柱 :Kromasil C₁₈-ODS(150mm×4.6mm ,5 μm)不锈钢柱 ;流动相 :水相 (800ml水 +21ml三乙胺 ,磷酸调pH 3.0 ,加水至 1000ml)-有机相 (正丙醇-乙腈 =2∶3)为 84∶16 ;检测波长:220nm ;含量测定采用外标法 ,杂质检查采用自身对照法。结果　在优化的色谱条件下 ,亮丙瑞林及杂质间均能完全分离 ,注射液辅料不干扰测定 ,亮丙瑞林线性范围 9.198～ 82.780 μg·ml^-1,检测限 1.93ng(S/N =3) ,含量测定的回收率 98.74%～100.3% ,RSD<1.5%。结论　该法专属性强,操作方便 ,结果准确 ,重现性好。     

胸部叩击及气流震荡叠加主动周期性呼吸在肺部感染性疾病中的应用

呼吸系统的疾病病因大都是来自肺部感染，感染的病因中细菌引起的肺炎最为常见。如肺炎链球菌、肺炎杆菌、大肠杆菌、绿脓杆菌等，肺部感染的早期治疗护理尤为重要，尤其是肺部异常分泌物的去除更为重要，而肺部异常分泌物的去除除了常规使用抗炎及对症治疗外，     

Functional limitation of the masticatory system in patients with bulbar involvement in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) with bulbar dysfunction affects the motor neurons responsible for controlling the muscles in the jaw, face, soft palate, pharynx, larynx and tongue. This cross‐sectional study aimed to determine the functional limitation of the jaw in patients with ALS and bulbar dysfunction who had upper motor neuron (UMN), lower motor neuron (LMN) or balanced involvement. One hundred and fifty‐three patients with ALS and 23 controls were included. All participants answered using the 8‐item Jaw Functional Limitation Scale (JFLS‐8). Patients with ALS were grouped by neurologic examination as follows: non‐bulbar ALS, bulbar UMN‐predominant ALS; bulbar LMN‐predominant ALS; and bulbar balanced (UMN + LMN) ALS. Jaw limitation between the different groups was compared using the Kruskal‐Wallis test. Patients with non‐bulbar ALS had similar mandibular limitations to healthy participants. Only patients with balanced UMN and LMN bulbar manifestations reported greater difficulties in chewing soft food or in jaw mobility compared to the non‐bulbar ALS group. Patients with bulbar involvement also had greater difficulties in chewing tough food or chicken and in swallowing and talking compared to the non‐bulbar group, regardless of whether UMN or LMN predominant. No significant differences were found between the groups in smiling and yawning difficulties. Bulbar involvement in patients with ALS is associated with functional limitation of the masticatory system. However, balanced bulbar UMN and LMN involvement is associated with the worst impairments in chewing soft food and in opening the jaw widely.