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.     

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.     

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。     

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.     

Cross-ministry data on service use and limitations faced by children in special education

BackgroundChildren with disabilities often face limitations that cross support sectors. Objective: Our aim was to measure cross-ministry service use, outcomes, and functional limitations faced by children who qualified for special education.MethodsWe used longitudinal British Columbia ministry data linked to children (0-18y) registered in K-12 education. Children were grouped by special education funding (most to least; Level 1, Level 2, Level 3, Unfunded, and no special education), and related to 1) service use patterns, 2) the age they first used disability services, and 3) functional limitations reported in health visits. We also reported how length of special education use related to disability service use.ResultsOf 111,274 children, 154(0.1%) were Level 1, 4427(4.0%) Level 2, 2897(2.6%) Level 3, 13472(12.1%) Unfunded, and 90324(81.2%) not in special education. Children with higher funding levels, compared to lower levels of funding, generally were more likely to experience poorer outcomes, have functional limitations, have service needs, and receive early support. One exception was children with serious behavioral/mental health special education coding, which had poorer outcomes for their level of funding. Children received child disability supports early (about half of users started by 4y), but use was mostly limited to those with many years (9+years) of funded special education (70.7% of the all users) and biased to certain special education codes (i.e., Level 1, severe intellectual disability, and autism).ConclusionsThis study provides evidence of the long-term, diverse needs of children in special education and may be used to inform decisions surrounding their support.     

Correlations between pain and function in a longitudinal low back pain cohort

Purpose.?Most studies of low back pain (LBP) and functional limitation have been cross-sectional, and show only modest correlations between pain and function. Though functional limitation may be superior for predicting disability outcomes, there is a need to understand better the gap between pain and function. This study analysed changes in intra-individual correlations between pain and function over time.

Method.?Seventeen men and 16 women currently experiencing LBP provided self-reports of LBP (0-to-10 scale) and functional status (Back Pain Functional Scale) for a maximum of 8 weeks. Spearman correlation coefficients between pain and function scores were calculated for each individual. The effects of pain history, pain intensity, variability and trends over time on pain–function correlations were assessed.

Results.?There were no significant differences in correlation due to gender, age or pain intensity (low versus high). Participants with steeper slopes in change in pain score over the study period had significantly stronger correlations to function than those with weaker trends, r?==??0.91 and r?==??0.45, respectively. Participants with at least one pain-free score during the reporting period had significantly stronger correlations than those with no pain-free reports, r?==??0.80 and r?==??0.51, respectively. Participants having the first episode LBP had stronger correlations (r?==??0.85) than those with persistent symptoms of LBP (r?==??0.62).

Conclusions.?The results suggest that over the course of LBP, within-person pain–function correlations are stronger than those reported in cross-sectional, population-based studies. Changes in pain ratings over time may have more clinical relevance than differences in pain levels between individuals. Among those with more long-standing pain, factors other than pain intensity, such as pain catastrophising or fear avoidant beliefs, may have a greater effect on day-to-day perceptions of functional limitation.