Cyclooxygenase-2 inhibition increases gastric tone and delays gastric emptying in rats.

We evaluated the effects of cyclooxygenase-2 (COX-2) selective inhibitors, COX-1 selective inhibitor, or COX non-selective inhibitor on gastric emptying and intestinal transit of liquids, and evaluated the effect of a COX-2 selective inhibitor on gastric tonus (GT). Male Wistar rats were treated per os with saline (control), rofecoxib, celecoxib, ketorolac, rofecoxib + ketorolac, celecoxib + ketorolac, or indomethacin. After 1 h, rats were gavage-fed (1.5 mL) with the test meal (5% glucose solution with 0.05 g mL(-1) phenol red) and killed 10, 20 or 30 min later. Gastric, proximal, medial or distal small intestine dye recovery (GDR and IDR, respectively) were measured by spectrophotometry. The animals of the other group were treated with i.v. valdecoxib or saline, and GT was continuously observed for 120 min using a pletismomether system. Compared with the control group, treatment with COX-2 inhibitors, alone or with ketocolac, as well as with indomethacin increased GDR (P < 0.05) at 10-, 20- or 30-min postprandial intervals. Ketorolac alone did not change the GDR, but increased the proximal IDR (P < 0.05) at 10 min, and decreased medial IDR (P < 0.05) at 10 and 20 min. Valdecoxib increased (P < 0.01) GT 60, 80 and 100 min after administration. In conclusion, COX-2 inhibition delayed the gastric emptying of liquids and increased GT in rats.     

纯钛表面酸碱处理及生物矿化的初步研究

目的:探讨不同的酸、碱处理条件下纯钛表面生物矿化沉积磷灰石层的差异。方法:对商用纯钛分别采用磨光处理、酸处理、酸碱处理或酸碱及热处理,然后放入模拟体液(SBF)中矿化处理7天;采用SEM观察试样表面的形貌,采用XRD分析试样表面沉积层的相组成。结果:经酸碱处理后纯钛形成微粗糙表面,随着碱液浓度的升高和采用热处理,试样表面的粗糙度增加且更均匀;经碱液处理的试样矿化后其表面出现磷灰石沉积层;而未处理组未发现磷灰石沉积层;XRD图谱分析发现矿化表面沉积物为HCA,钙磷比为1.37。结论:碱液处理有利于磷灰石层的形成,而改变碱液浓度和是否采用热处理对磷灰石沉积能力有影响。     

Overt use of a tactile/kinaesthetic strategy shifts to covert processing in rehabilitation of letter-by-letter reading

Background: Letter-by-letter readers identify each letter of the word they are reading serially in left to right order before recognising the word. When their letter naming is also impaired, letter-by-letter reading is inaccurate and can render even single word reading very poor. Tactile and/or kinaesthetic strategies have been reported to improve reading in these patients, but only under certain conditions or for a limited set of stimuli.

Aims: The primary aim of the current study was to determine whether a tactile/kinaesthetic treatment could significantly improve reading specifically under normal reading conditions, i.e., reading untrained words presented in free vision and read without overt use of the strategy.

Methods & Procedures: Three chronic letter-by-letter readers participated in a tactile/kinaesthetic treatment aimed at first improving letter-naming accuracy (phase 1) and then letter-by-letter reading speed (phase 2). In a multiple case series design, accuracy and speed of reading untrained words without overt use of the trained tactile/kinaesthetic strategy was assessed before phase 1, after phase 1, and again after phase 2.

Outcomes & Results: All three patients significantly improved both their speed and accuracy in reading untrained words without overt use of the trained tactile/kinaesthetic strategy. All three patients required the additional practice in phase 2 to achieve significant improvement. Treatment did not target sentence-level reading, yet two of the three patients became so adept that they could read entire sentences.

Conclusions: This study replicates previous findings on the efficacy of tactile/kinaesthetic treatment for letter-by-letter readers with poor letter naming. It further demonstrates that this treatment can alter cognitive processing such that words never specifically trained can be read in free vision without overtly using the trained strategy. The data suggest that an important element in achieving this level of generalisation is continuing training beyond the point of initial mastery (i.e., accurate letter naming).     

Differential Reorganization of Fusiform Gyrus in Two Types of Alexia after Stroke

Lesions affecting the left fusiform gyrus (FG) commonly result in dyslexia and recovery largely depends on efficient reorganization of the reading network. We performed a follow-up fMRI study to elucidate the reorganization patterns of the FG according to the recovery of reading ability in two patients (MH with pure alexia and KM with alexia with agraphia) after stroke involving the left FG. Initially, MH was an effortful letter-by-letter (LBL) reader, and she improved to become a proficient LBL reader. The initial fMRI results showed scattered activation on occipital and ventral temporal cortex during reading, which was localized to right FG in the follow-up study. KM's severe alexia with agraphia did not improve, even after 6 months had passed since the onset of the alexia. The initial and follow-up fMRI results showed no significant activation in the bilateral FG or central higher language areas during word reading. Our results suggest that the reorganization of the FG is different according to the type of alexia and the amount of clinical recovery in each patient. Also, the successful reorganization of the visual component of reading in the right FG is responsible for the recovery of LBL reading in pure alexia.     

Pure motor stroke as the most frequent lacunar syndrome: A clinical update

Pure motor stroke (PMS), also known as pure motor hemiparesis, is the most common of any lacunar form (between one half and two thirds of cases, depending on the series). In an acute stroke registry, 733 patients presented a lacunar infarct and PMS accounted for 12.7% (n = 342) of all first-ever stroke patients and for 48% of all lacunar syndromes. The posterior limb of the internal capsule, corona radiata, and pons are the most frequent brain topographies. Infarcts in the mesencephalus or medullary pyramid have been exceptionally reported. This present update is focused on the clinical evidence and mechanisms underlying the relationship between PMS and different stroke etiologies.     

Comparison of heart rate variability parameters during complex partial seizures and psychogenic nonepileptic seizures

Purpose: Psychogenic nonepileptic seizures (PNES) superficially resemble epileptic seizures. Little is known about ictal autonomic nervous system (ANS) activity changes in epilepsy and PNES. This study compares ictal heart rate variability (HRV) parameters as a reflection of ANS tone in epileptic seizures and PNES, and explores differences between interictal and ictal ANS tone in both patient groups. Methods: Ictal HRV parameters were extracted from single‐lead electrocardiography (ECG) data collected during video–electroencephalography (EEG) recordings of 26 patients with medically refractory temporal lobe epilepsy and 24 age‐ and sex‐matched patients with PNES. One seizure per patient in a resting, wake, supine state was analyzed. Interictal ECG data were available for comparison from 14 patients in both groups. HRV parameters in time and frequency domains were analyzed (low frequency [LF], high frequency [HF], standard deviation of all consecutive normal R wave intervals [SDNN], square root of the mean of the sum of the squares of differences between adjacent normal R wave intervals [RMSSD]). CVI (cardiovagal index), CSI (cardiosympathetic index), and ApEn (approximate entropy) were calculated from Lorenz plots. Key Findings: There were significant differences between ictal HRV measures during epileptic and nonepileptic seizures in the time and frequency domains. CSI (p < 0.001) was higher in epileptic seizures. Time interval between two consecutive R waves in the ECG (RR interval) (p = 0.002), LF (p = 0.02), HF (p = 0.003), and RMSSD (p = 0.003) were significantly lower during epileptic seizures. Binary logistic regression yielded a significant model based on the differences in CSI classifying 88% of patients with epilepsy and 73% of patients with PNES correctly. The comparison between resting and ictal states in both seizure disorders revealed significant differences in RR interval (epilepsy p < 0.001, PNES p = 0.01), CSI (epilepsy p < 0.001, PNES p = 0.02), HF (epilepsy p = 0.002, PNES p = 0.03), and RMSSD (epilepsy p = 0.004, PNES p = 0.04). In patients with epilepsy there were also significant differences in ictal versus interictal mean values of ApEn (p = 0.03) and LF (p = 0.04). Although CSI was significantly higher, the other parameters were lower during the seizures. Stepwise binary regression in the 14 patients with epilepsy produced a significant model differentiating resting state from seizures in 100% of cases. The same statistical approach did not yield a significant model in the PNES group. Significance: Our results show greater ANS activation in epileptic seizures than in PNES. The biggest ictal HRV changes associated with epileptic seizures (CSI, HF, and RMSSD) reflect high sympathetic system activation and reduced vagal tone. The reduced ApEn also reflects a high sympathetic tone. The observed ictal alterations of HRV patterns may be a more specific marker of epileptic seizures than heart rate changes alone. These altered HRV patterns could be used to detect seizures and also to differentiate epileptic seizures from PNES. Larger studies are justified with intergroup and intragroup comparisons between ictal and resting states.     

Hearing results of surgery for tympanosclerosis

Between January 1990 and December 2003, 117 patients were surgically treated for tympanosclerosis at a tertiary referral center. The objective of our study was to review the hearing results in this cohort. The patients were divided into three groups: predominant involvement of tympanic membrane (33 cases), predominant fixation of malleus or/and incus (72 cases), and stapedial fixation (12 cases). Preoperative and postoperative air–bone gap (ABG), and pure tone average (PTA) were compared after short-term and long-term follow-up, and statistical significance was determined. After surgery, air–bone gap was improved by 11.7 dB after short-term, and by 10.9 dB after long-term observation period. The improvement of ABG was not significantly different between the groups. Pure tone average (PTA) was improved by 15.2 dB in short-term period, with decrease of results in the long-term follow-up to 10.3 dB. Successful hearing result as judged by ABG was obtained in 66.7% with affected tympanic membrane, in 65.3% with malleus or/and incus fixation, and in 50.0% with stapedial fixation. Statistical analysis confirmed significant improvement of hearing for all groups. Highly significant difference was noted for low frequency ABG (0.5, 1, and 2 kHz). Hearing improvement on ABG was preserved after long-term observation. No significant sensorineural hearing loss was seen in this series. Surgery for tympanosclerosis results in significant improvement of ABG and PTA. Most of the improvement is obtained in lower frequencies. Long-term results are comparable to short-term results, with slight hearing deterioration in stapedial fixation.     

An experimental model for the study of transient lower oesophageal sphincter relaxation and motor function of the proximal stomach in humans

A simple and reliable experimental model would be useful in human research on new drugs which target transient lower oesophageal sphincter (LOS) relaxation. The aim was to investigate the effect of repeated distensions on the rate of transient LOS relaxation, LOS pressure and motor function of the proximal stomach. Twelve healthy subjects were studied with a multilumen manometric assembly incorporating a sleeve sensor for the LOS and a bag positioned in the proximal stomach and connected to a barostat. Intrabag volume was set at 75% of the threshold for gastric discomfort and maintained for two 30-min distension periods separated by a 45-min washout with the bag deflated. The studies lasted 145 +/- 2 min. The rate of transient LOS relaxations was similar during the two distensions, 3.5;2-4 vs 3;2.5-4 (median;interquartile range) and so was LOS pressure. Baseline intrabag pressure, as a measure of gastric tone, and the number of pressure waves, as a measure of phasic contractions, were also similar, 11.3;9.3-12.3 mmHg vs 10.8;9.3-12.5 mmHg and 16;13-28 mmHg vs 19;15-29 mmHg, respectively. Our model allows to perform 1-day studies which can assess two experimental conditions on transient LOS relaxations and motor function of the proximal stomach within an acceptable time span.     

纯钛嵌体微渗漏的对比研究

目的评价纯钛嵌体分别采用三种不同粘结材料粘结的微渗漏情况,为临床应用提供参考依据。方法选择36颗健康上前磨牙,随机分为3个实验组,每组12颗牙。分别用玻璃离子水门汀、树脂改良型玻璃离子水门汀和树脂水门汀粘结固位。统计学方法,应用sPss10．0统计学软件,采用Kruskal—Wallis检验和Mann—Whitney U秩和检验,取α=0．05为显著性标准。结果①同一种材料嵌体用不同粘结材料粘结,其微渗漏程度差异有统计学意义（P〈0．05）;②轴壁的微渗漏较龈壁的微渗漏差异有统计学意义（P〈0．05）。结论①树脂改良型玻璃离子水门汀和树脂水门汀的抗微渗漏性能优于玻璃离子水门汀。②轴壁的微渗漏较龈壁的微渗漏明显减小。     

Increases in spontaneous activity in the dorsal cochlear nucleus of the rat following exposure to high-intensity sound

The effects of intense sound exposure on neural activity in the dorsal cochlear nucleus (DCN) were studied in the rat. Seventeen anesthetized adult rats were exposed to a 10-kHz tone at 125–130 dB SPL for 4 h. Fourteen unexposed rats served as controls. Spontaneous activity (SA) and neural thresholds at the characteristic frequency were measured in three rows of 8–12 sites along the mediolateral, tonotopic, axis of the DCN surface 27–61 days after exposure. The results showed that intense tone exposure induced chronic increases in SA. This hyperactivity was found to be distributed broadly across the DCN with an emphasis around the 10-kHz locus and was associated with shifted response thresholds. These findings demonstrate the usefulness of the rat for studies of physiological phenomena related to noise-induced tinnitus and hearing loss.