Neuroanatomy of dyslexia: An allometric approach

Despite evidence for a difference in total brain volume between dyslexic and good readers, no previous neuroimaging study examined differences in allometric scaling (i.e. differences in the relationship between regional and total brain volumes) between dyslexic and good readers. The present study aims to fill this gap by testing differences in allometric scaling and regional brain volume differences in dyslexic and good readers. Object‐based morphometry analysis was used to determine grey and white matter volumes of the four lobes, the cerebellum and limbic structures in 130 dyslexic and 106 good readers aged 8–14 years. Data were collected across three countries (France, Poland and Germany). Three methodological approaches were used as follows: principal component analysis (PCA), linear regression and multiple‐group confirmatory factor analysis (MGCFA). Difference in total brain volume between good and dyslexic readers was Cohen's d = 0.39. We found no difference in allometric scaling, nor in regional brain volume between dyslexic and good readers. Results of our three methodological approaches (PCA, linear regression and MGCFA) were consistent. This study provides evidence for total brain volume differences between dyslexic and control children, but no evidence for differences in the volumes of the four lobes, the cerebellum or limbic structures, once allometry is taken into account. It also finds no evidence for a difference in allometric relationships between the groups. We highlight the methodological interest of the MGCFA approach to investigate such research issues.     

Determination of toxic element levels (lead and cadmium) in commonly used cosmetic products in Iran

Toxic elements are commonly used in cosmetic products for many reasons like coloring pigments or blocking ultraviolet light; however, the level of some metals exceed specific concentration which can cause serious safety issues. This study aims to evaluate the content of lead and cadmium in samples of sunscreen and foundation creams, most frequently used brands of cosmetic products, in Iran. Concentration of lead in the sunscreens and foundation creams was lower than that of USFDA standards. The content of cadmium was higher than Europe Union standard. Effort must be made to inform the users about the harmful consequences of cosmetics.     

Effect of long-term administration of ranitidine,a histamine H2 receptor antagonist,on bone metabolism in young growing rats

Background

Histamine regulates function of osteoclasts and osteoblasts, however data regarding the influence of histamine H2 receptors antagonists on bone tissue are ambiguous. Factors that influence growing skeleton may have an important impact on the peak bone mass and future risk of fractures. The aim of our study was the assessment of influence of ranitidine, on growing bones.

Influence of fiber-reinforced composites on the resistance to fracture of vertically fractured and reattached fragments

Introduction

The aim of this in vitro study was to evaluate the fracture type and test the effects of 2 different fibers on fracture strength of roots with reattached fragments. The null hypothesis was that adding suitable fibers to the content of dual-cure adhesive resin cement increases the fracture resistance of reattached fragments under vertical forces.

Methods

Root canals of 45 teeth were prepared, and the teeth were intentionally fractured into 2 separate fragments. Control groups (n = 7 each) consisted of unfractured teeth with instrumented and obturated or only instrumented root canals. The fractured teeth were divided into 3 groups (n = 15 each), and separated fragments were reattached by using (1) dual-cured resin cement (Clearfil SA), (2) dual-cured resin cement + polyethylene fiber (Construct), or (3) dual-cured resin cement + glass fiber (Stick-Net). Force was applied at a constant speed of 0.5 mm/min to the root until fracture. Mean load was recorded and analyzed statistically by using Kruskal-Wallis and Dunn tests (P = .05). Fracture types were analyzed by using χ² analysis with Yates correction.

Results

Stick-Net demonstrated the lowest fracture resistance (P < .05), whereas Construct and Clearfil SA had similar fracture strengths (P > .05). The roots in the control group showed the highest fracture resistance. However, there was no statistically significant difference between the Construct, Clearfil SA, and control groups (P > .05).

Conclusions

Separated fragments of vertically fractured teeth can be reattached by using a dual-cured resin or by adding polyethylene fiber (Construct).     

拔牙畏惧的患者自控疗法研究

目的：用提高患者的自控能力来缓解患者拔牙时的就诊压力。方法：对第一次拔取第三磨牙的患者作牙科畏惧评定，筛选出患有牙科畏惧症的患者，拔牙术前给予三种不同的外科准备，评价患者对自控能力的信心和术中的行为反应，并将各组结果进行比较。结果：术前放松组减轻了患者的就诊压力，改善了术中的行为反应，而术前放松强化组又优于单纯的放松组。结论：患者的自信和自控是可操纵的，这种心理辅助疗法能减轻患者面对牙科就诊的压力。     

Evidence for reactive nitrogen species formation in the gingivomucosal tissue

An increase in nitric oxide production has been demonstrated in periodontitis. Here we investigated the potential role of nitric-oxide-derived nitrating species (such as peroxynitrite) in a rat model of ligature-induced periodontitis. Formation of 3-nitrotyrosine, the stable product formed from tyrosine reacting with nitric-oxide-derived nitrating species, was detected in the gingivomucosal tissue. 3-Nitrotyrosine immunohistochemical analysis revealed a significant elevation in the number of immunopositive leukocytes, and higher immunoreactivity of the gingival ligaments and epithelium in the ligated than in the contralateral (control) side. On both sides, several 3-nitrotyrosine-positive bands and, on the ligated side, a unique 52-kDa 3-nitrotyrosine-positive band were detected by Western blot. However, in the sterile gingivomucosal tissue of rat pups, no 3-nitrotyrosine or inducible nitric oxide synthase immunoreactivity was found. Analysis of these data suggests that resident bacteria of the gingivomucosal tissue induce an increase in reactive nitrogen species, which is greatly enhanced by plaque formation in periodontitis.     

Validity of conventional surgical treatment methods for mandibular dentigerous cysts. Two case reports

Dentigerous cysts, which are the most commonly seen odontogenic cysts in the jaws, usually expand asymptomatically and extensively. They are surgically eliminated along with the accompanying impacted tooth, because of their destructive nature to the surrounding vital structures, tissues, bone and teeth. The surgical treatment for removing dentigerous cysts includes decompression, marsupialization, enucleation or curettage of the cyst through an extraoral or intraoral approach. Cysts causing tooth displacement and involving loss of bone are treated by marsupialization or decompression, followed by enucleation. In the cases presented here, both patients had enlarged dentigerous cysts in the left mandibular molar region, with an accompanying impacted tooth. Both cases were treated surgically by the enucleation technique alone, without any need for additional autogenous grafts or alloplastic materials to regain integrity of bone structure. They were rehabilitated with dental implants. The implant-retained fixed prostheses functioned well throughout the 24-month evaluation time; and the functional and psychological needs of the patients were provided successfully.     

抑郁症患者健康知识需求调查分析

目的 了解抑郁症患健康知识需求。方法 采用自行设计问卷调查表发放给32例抑郁症病人。结果 病人最迫切需求的健康知识内容是：疾病相关知识，用药知识，心理调护。在入院初期需求率较低，恢复期需求率较高。康复知识在恢复期需求率较高。康复期最需求预防疾病复发知识和复查时间，需求率分别为96．9％、93．8％。结论 对患进行健康教育，必须针对患疾病各个时期的健康需求，有利于促进疾病康复，明显降低复发率。     

One year follow-up of alcohol and illicit substance use in first-episode psychosis: Does gender matter?

Longitudinal studies on first-episode psychosis (FEP) patients have shown a decrease of substance use disorders (SUDs) over the first years of illness, but there has been less focus on the gender aspect. The present study examines stability of alcohol and illicit substance use, with specific focus on gender, in a one year follow-up investigation of 154 FEP patients (91 men, 63 women) in Oslo, Norway, using criteria for DSM-IV substance use disorder diagnosis, the Alcohol Use Disorders Identification Test (AUDIT) and the Drug Use Disorders Identification Test (DUDIT). The results show that cannabis was the most frequently used illicit substance at both times. Significantly more men (34%) than women (13%) had a current illicit SUD at baseline. At follow-up, the rate of illicit SUDs was significantly reduced in men (18%) but not in women (11%). There were no significant gender differences in the rate of current alcohol use disorders (AUD) (men 14%; women 8%) at baseline, and no significant reduction in AUD in any of the genders at follow-up. At follow-up, total AUDIT and DUDIT scores were reduced in men only. In conclusion, the high and persistent rate of SUDs, particularly of cannabis, among men and women during the first year of treatment for psychosis should be addressed in the clinical management of the patients. Female FEP patients who are also substance users may be particularly vulnerable in this regard and warrant closer attention.