A multicenter study of the clinical features of allergic rhinitis in central China.

BACKGROUND: Several epidemiological surveys of allergic rhinitis (AR) have been conducted in China. However, the clinical features of AR are still not clear enough. The aim of the current study was to perform a multicenter investigation to evaluate the clinical features of AR in China. METHODS: A multicenter investigation was performed in 13 allergy centers in central China. A disease-related questionnaire was completed by each patient themselves or with guardian assistance after the diagnosis of AR. The clinical features of AR and allergen profile were analyzed. RESULTS: Eleven thousand four patients who were diagnosed with AR were recruited in this study. The percentages of classification of AR according to the Allergic Rhinitis and Its Impact on Asthma guidelines were 9.7% intermittent mild (IM), 3.1% persistent mild (PM), 33.9% intermittent moderate-severe (IMS), and 53.3% persistent moderate-severe (PMS). There were 61.6 and 42.2% AR patients who had concomitant ocular or lower respiratory symptoms in clinic. The occurrence of ocular and lower respiratory symptoms was found to be gradually increased from IM, PM, and IMS to PMS. Cold air and temperature change were the two most common factors triggering the nasal symptoms. Dermatophagoides pteronyssinus and Dermatophagoides farinae were the most important allergens of central China. CONCLUSIONS: This study has contributed to a better understanding of clinical features of AR in China.

A prospective multicenter study of systemic reactions in standardized specific immunotherapy for allergic rhinitis in China.

BACKGROUND: Standardized allergen-specific immunotherapy (SIT) has been used in China for years. However, there is no extensive study of the safety of standardized SIT in Chinese patients until now. The aim of the current study is to perform a prospective and multicenter study to evaluate the systemic reactions (SRs) of standardized SIT in Chinese patients. METHODS: The study was performed in 13 allergy centers in China, using the same vaccine and practice procedure. The length of observation period was 2 years. SRs were recorded and analyzed. RESULTS: There were 666 patients included (261 children and 405 adults). All patients finished the initial phase and 47 patients withdrew during the maintenance phase. There were 0.47% (94/19,963) SRs in all injections (0.72% in children and 0.31% in adults); 8.26% (55/666) patients experienced SRs (12.26% children and 5.68% adults). The occurrence of SRs was significantly higher in children than that in adults (p < 0.01). A higher ratio of SRs was found among patients accompanied with asthma. There were 74.47% SRs of grade I, 15.96% SRs of grade II, 7.45% SRs of grade III, and 2.13% SRs of grade IV. There were 90.43% of SRs associated with the discomfort of lower respiratory tract. CONCLUSION: This multicenter study showed that properly conducted standardized SIT was a safe treatment for allergic rhinitis in China. The incidence of SRs was higher in children than that in adults.

Toxoplasma gondii immunoglobulin G antibodies and nonfatal suicidal self-directed violence.

OBJECTIVE: The primary aim was to relate Toxoplasma gondii seropositivity and serointensity to scores on the self-rated Suicide Assessment Scale (SUAS-S). Another aim was to reevaluate the previously reported positive association between T gondii serointensity and a history of nonfatal suicidal self-directed violence. METHOD: This cross-sectional, observational study compared T gondii serointensity and seropositivity in plasma from 54 adult suicide attempters (inpatients at Lund University Hospital, Lund, Sweden) and 30 adult control subjects (randomly selected from the municipal population register in Lund, Sweden) recruited between 2006 and 2010. The potential of patients and controls for self-directed violence was evaluated with the SUAS-S. Psychiatric diagnoses were made according to DSM-IV criteria. Plasma samples were tested for immunoglobulin G antibodies to T gondii, cytomegalovirus, and herpes simplex virus type 1. Data were analyzed using multivariable logistic regression to investigate the association between T gondii serointensity or seropositivity and a history of nonfatal suicidal self-directed violence; multivariable linear regression was used to explore the relationship between T gondii serointensity or seropositivity and the SUAS-S. Both regression models included sex, age, and body mass index as covariates. RESULTS: Seropositivity of T gondii (adjusted odds ratio [OR] = 7.12; 95% CI, 1.66-30.6; P = .008) and serointensity of T gondii (adjusted OR = 2.01; 95% CI, 1.09-3.71; P = .03) were positively associated with a history of nonfatal suicidal self-directed violence. Seropositivity of T gondii was associated with higher SUAS-S scores, a relationship significant for the whole sample (P = .026), but not for suicide attempters only. No significant associations with other pathogens were identified. CONCLUSIONS: These results are consistent with previous reports on the association between T gondii infection and nonfatal suicidal self-directed violence. Confirming these results in future large longitudinal studies and including suicide as an outcome may lead to novel individualized approaches in suicide prevention.

Identification of neural feedback for upright stance in humans: stabilization rather than sway minimization.

A fundamental issue in motor control is how to determine the task goals for a given behavior. Here, we address this question by separately identifying the musculoskeletal and feedback components of the human postural control loop. Eighteen subjects were perturbed by two mechanical perturbations (gentle pulling from behind at waist and shoulder levels) and one sensory perturbation (movement of a virtual visual scene). Body kinematics was described by the leg and trunk segment angles in the sagittal plane. Muscle activations were described by ankle and hip EMG signals, with each EMG signal computed as a weighted sum of rectified EMG signals from multiple muscles at the given joint. The mechanical perturbations were used to identify feedback, defined as the mapping from the two segment angles to the two EMG signals. The sensory perturbation was used to estimate parameters in a mechanistic model of the plant, defined as the mapping from the two EMG signals to the two segment angles. Using the plant model and optimal control theory, we compared identified feedback to optimal feedback for a range of cost functions. Identified feedback was similar to feedback that stabilizes upright stance with near-minimum muscle activation, but was not consistent with feedback that substantially increases muscle activation to reduce movements of the body's center of mass or center of pressure. The results suggest that the common assumption of reducing sway may not apply to musculoskeletal systems that are inherently unstable.

Visual flow is interpreted relative to multisegment postural control.

To control upright stance, the human nervous system must estimate the movements of multiple body segments based on multisensory information. To investigate how visual information contributes to such multisegmental estimation, participants were exposed to 3 types of visual-scene movement: translation in the anteroposterior direction, rotation about the ankle joint, and rotation about the hip joint. Trunk and leg responses were larger for rotational than for translational movements, but only at lower stimulus frequencies. Based on a feedback-control theoretical framework, these results indicated that visual inputs distinguish between translation and rotation of the head. Also, visual condition effects were similar for the leg and trunk segments, suggesting a control strategy with a single control signal that determines the activation of all muscles.

Quality of reporting of randomized clinical trials in tai chi interventions-a systematic review.

Objectives. To evaluate the reporting quality of published randomized clinical trials (RCTs) in the Tai Chi literature following the publication of the CONSORT guidelines in 2001. Data Sources. The OVID MEDLINE and PUBMED databases. Review Methods. To survey the general characteristics of Tai Chi RCTs in the literature, we included any report if (i) it was an original report of the trial; (ii) its design was RCT; (iii) one of the treatments being tested was Tai Chi; and (iv) it was in English. In addition, we assessed the reporting quality of RCTs that were published between 2002 and 2007, using a modified CONSORT checklist of 40 items. The adequate description of Tai Chi interventions in these trials was examined against a 10-item checklist adapted from previous reviews. Results. The search yielded 31 Tai Chi RCTs published from 2002 to 2007 and only 11 for 1992-2001. Among trials published during 2002-2007, the most adequately reported criteria were related to background, participant eligibility and interpretation of the study results. Nonetheless, the most poorly reported items were associated with randomization allocation concealment, implementation of randomization and the definitions of period of recruitment and follow-up. In addition, only 23% of RCTs provided adequate details of Tai Chi intervention used in the trials. Conclusion. The findings in this review indicated that the reporting quality of Tai Chi intervention trials is sub-optimal. Substantial improvement is required to meet the CONSORT guidelines and allow assessment of the quality of evidence. We believe that not only investigators, but also journal editors, reviewers and funding agencies need to follow the CONSORT guidelines to improve the standards of research and strengthen the evidence base for Tai Chi and for complementary and alternative medicine.

The influence of sensory information on two-component coordination during quiet stance.

When standing quietly, human upright stance is typically approximated as a single segment inverted pendulum. In contrast, investigations, which perturb upright stance with support, surface translations or visual driving stimuli have shown that the body behaves like a two-segment pendulum, displaying both in-phase and anti-phase patterns between the upper and lower body. We have recently shown that these patterns co-exist during quiet stance; in-phase and anti-phase for frequencies below and above 1 Hz, respectively. Here we investigated whether the characteristics of these basic patterns were influenced by the addition or removal of sensory information. Ten healthy young subjects stood upright on a rigid platform with different combinations of sensory information: eyes were open or closed with or without light touch contact (<1N) of the right index fingertip with a 5 cm diameter rigid force plate. The in-phase and anti-phase pattern co-exist in both the anterior-posterior (AP) and medial-lateral (ML) directions of sway. The real part of trunk-leg complex coherence decreased with the addition of vision and light touch, corresponding to a transition from the in-phase to anti-phase pattern at a lower frequency. In the AP direction, the decrease was only observed at frequencies below 1 Hz where the in-phase pattern predominates. Additional sensory information had no observable effect at sway frequencies above 1 Hz, where the anti-phase pattern predominates. Both patterns are clearly the result of a double-linked inverted pendulum dynamics, but the coherence of the in-phase pattern is more susceptible to modulation by sensory information than the anti-phase pattern.

Sensory reweighting with translational visual stimuli in young and elderly adults: the role of state-dependent noise.

The properties of sensory reweighting for control of human upright stance have primarily been investigated through experimental techniques such as sinusoidal driving of postural sway. However, other forms of visual inputs that are commonly encountered, such as translation, may produce different adaptive responses. We directly compared sinusoidal and translatory inputs at stimulus parameters that made stimulus velocity comparable with each type of stimulus. Young healthy individuals were compared with healthy elderly and elderly designated as "fall-prone" to investigate whether the hypothesized basis for poor balance control in the "fall-prone" elderly is related to their ability to reweight sensory inputs appropriately. Standing subjects were presented with visual displays which moved in the medial-lateral direction either by (1) oscillating at different amplitudes or (2) simultaneously oscillating and translating at different speeds. All three subject groups showed that increasing the amplitude of the oscillations led to a decrease in gain. Increasing translation speed led to decreases in gain only at speeds above 1 cm/s. This suggests that the nervous system is processing more than just stimulus velocity to determine the postural response. A model implementing "state-dependent noise", in which visual stimulus noise increases with relative speed, was developed to account for the difference between translation and oscillation. The weak group effects question the common view that the fall-prone elderly are deficient in sensory reweighting. One explanation for the apparent discrepancy is that the slow, small-amplitude visual stimuli used in this study probe the asymptotic dynamics of the postural response. If given enough time, even the fall-prone elderly are able to adapt to a new sensory environment appropriately. However, the asymptotic adaptive response may not be functional in terms of preventing falls.