Periodontal mechano-sensory responses following trauma to permanent incisor teeth in children

Abstract –  The aim of this study was to investigate mechano-sensory responses of injured and uninjured incisor teeth. Twenty-five children who had experienced dental trauma, together with age- and gender-matched controls, were studied prospectively. Touch thresholds of incisor teeth from both groups were determined using calibrated sets of von Frey hairs (force range 0.5–10.0 g in 0.5 g increments) using a forced choice staircase method. Forces were applied perpendicular to the buccal enamel surfaces along the midline, 2 mm from the incisal edge. Touch threshold was defined as the lowest force detected in three out of the five occasions. Following statistical analysis, P  < 0.05 was considered significant. At initial examination, the touch threshold values of 25 traumatised teeth were significantly greater than the untraumatised controls ( P  < 0.001), and these values approached those of the control teeth over 3–12 months ( P  > 0.05). Dental trauma was associated with increased touch thresholds in permanent incisor teeth, with recovery toward healthy control values usually occurring between 3–12 months.     

MANAGEMENT TO PREVENT BLEEDING DURING ENDOSCOPIC SUBMUCOSAL DISSECTION USING THE FLUSH KNIFE FOR GASTRIC TUMORS

The gastric vasculature responsible for intraoperative bleeding in endosocpic submucosal dissection (ESD) is the ramified vascular network occupying the middle of the submucosal layer and large vessels penetrating the muscle layer. Appropriate management for these vessels must be addressed. The trimming of the ramified vascular network can be safely performed with coagulation mode following shallow mucosal cutting. A large penetrating vessel usually requires precoagulation prior to dissection. These procedures are effectively performed with the water jet short needle knife (Flush knife).     

不同针刺深度对前列腺增生症大鼠重量指数的影响及形态学观察

目的与方法 采用深刺和浅刺对丙酸睾酮所致前列增生症（BPH）大鼠模型进行干预，研究其作用殊同。结果 针刺组前列腺，膀胱指数明显小于模型组；形态学观察，针刺组较模型组增生明显减轻，腺上皮呈单层柱状，腺体数目明显减少，间质充血，钙化明显减轻，结缔组织无增生，腺腔内分泌物减少。深刺组好于浅刺组。结论 深刺对实验性BPH大鼠的干预作用好于浅刺方法。     

Effect of Guchi Gao on HGF and PDL in periodontal tissue cells

The effects of eight herbs of Guchi Gao on periodontal tissue cells were investigated. The results show that Herba Dendrobii, Radix Ophiopogonis, and two other herbs can significantly promote attachment of human gingival fibroblasts (HGF) and periodontal ligament cells (PDL) and enhance the proliferation of the latter. This may account for the effect of Guchi Gao and suggests a potential treatment for periodontitis in the future.     

方丝弓矫治器加载与牙松动度提取参数关系的初步探讨

目的：研究FX－1型牙松动度测量系统提取参数与临床牙松动度的关系。进一步明确其临床实用价值。方法：受试者为安底二类错He畸形患者，男2人，女4人，受试牙为B区中切牙、B区第一前磨牙；方丝弓矫治器加载前后各测定1次，间隔8－11d；第一牙位测定7次，测量时间为上午10时；测量前后各拍摄X线片一张。结果：方丝弓矫治器加载前爱试牙临床松动度不足Ⅰ度，加载后均达到Ⅰ度；X线片示加载后除近牙颈部牙周膜腔略为增宽外，余无明显变化，方丝弓矫治器加载前后，参数S、K值的变化不具有统计学上的显著性差异，而参数t1,t2加载后经加载前增大，且具有统计学上的显著性差异，结论：牙松动度信号中的时间参数t1,t2能够早期监测临床牙松动度的改变。     

Auditory arousal thresholds after selective slow-wave sleep deprivation.

OBJECTIVES: The aim of this study is to assess Auditory Arousal Thresholds (AATs) three times during an undisturbed baseline night and to compare them to AATs during the recovery night that follows two consecutive nights of selective SWS deprivation. The presence of a time-of-night effect on AATs will also be assessed. METHODS: Ten male Ss slept in the laboratory for 6 consecutive nights. The first two nights were undisturbed. The 3rd night was considered as baseline. During the 4th and 5th nights, selective SWS deprivation was obtained by means of acoustic stimulation. The 6th night was a recovery. In the last 4 nights Ss were awakened three times, after 2, 5 and 7.5 h of sleep, respectively. All the awakenings were carried out from stage 2 (after at least 5 consecutive min of stage 2), by means of 1000 Hz ascending tone series. The AAT determination was based on EEG-EMG criteria: at least 10-s of clear alpha rhythm and/or a 10 s movement arousal. RESULTS: During both deprivation nights, SWS amount was close to zero. In the ensuing recovery night a significant SWS rebound was found, accompanied by a significant increase of AATs with respect to the baseline. Furthermore, there was a significant linear decrease of AATs during the night. Finally, the individual correlations between AATs and SWS amount were significant in 4 out of 10 Ss. CONCLUSIONS: These results confirm that AATs are a reliable index of sleep depth by showing that the SWS rebound following selective SWS deprivation is paralleled by a significant AAT enhancement. The experimental paradigm also allows us to claim that AATs show a decreasing linear trend during the night, having excluded any procedural bias. Finally, AATs can be directly related to SWS amount that preceded the awakening, although the individual correlations between AATs and SWS have to be considered with caution, given the high inter-subject variability and the small number of observations.     

Non‐invasive monitoring of muscle blood perfusion by photoplethysmography: evaluation of a new application

Aim: To evaluate a specially developed photoplethysmographic (PPG) technique, using green and near‐infrared light sources, for simultaneous non‐invasive monitoring of skin and muscle perfusion. Methods: Evaluation was based on assessments of changes in blood perfusion to various provocations, such as post‐exercise hyperaemia and hyperaemia following the application of liniment. The deep penetrating feature of PPG was investigated by measurement of optical radiation inside the muscle. Simultaneous measurements using ultrasound Doppler and the new PPG application were performed to elucidate differences between the two methods. Specific problems related to the influence of skin temperature on blood flow were highlightened, as well. Results: Following static and dynamic contractions an immediate increase in muscle perfusion was shown, without increase in skin perfusion. Liniment application to the skin induced a rapid increase in skin perfusion, but not in muscle. Both similarities and differences in blood flow measured by Ultrasound Doppler and PPG were demonstrated. The radiant power measured inside the muscle, by use of an optical fibre, showed that the near‐infrared light penetrates down to the vascular depth inside the muscle. Conclusions: The results of this study indicate the potentiality of the method for non‐invasive measurement of local muscle perfusion, although some considerations still have to be accounted for, such as influence of temperature on blood perfusion.     

Visual pursuit over textured backgrounds in different depth planes

Summary Several investigators have reported that voluntary pursuit of a moving object is less smooth when it moves over a textured background compared with when it moves over a dark background. Furthermore, when a person fixates a stationary target on a moving background, microdrifts of the eyes occur in the direction of motion of the background. These two facts suggest that OKN is not completely switched off during voluntary pursuit or fixation. Howard and Simpson (1989) found that optokinetic nystagmus (OKN) is only weakly evoked by moving stimuli which are out of the plane of convergence. This led to the prediction that voluntary pursuit of a visual target should be disrupted more by a stationary background in the same depth plane than by a background which is nearer or further away than the pursuit target. Pursuit disruption was measured by the frequency and total amplitude of saccadic intrusions. For horizontal pursuit, disruption was reduced, compared with the coplanar condition, when the textured background was further away than the target but not when it was nearer. For vertical pursuit, disruption was reduced in both the far and near conditions compared with the coplanar condition. In both cases disruption was least when the background was dark.