Deformation of the corona radiata and internal capsule in normal pressure hydrocephalus

Background and purposeThe pathophysiology of the clinical manifestations in normal pressure hydrocephalus (NPH) remains obscure. Ventricular dilatation could generate forces on the paracentral fibers of the corona radiata (CR), hence interfering with their function and producing the classical clinical triad. The analysis of the regional displacement and deformation of the white matter bundles, forming the corona radiata and internal capsule, may clarify the relationship between ventricular dilatation and clinical manifestations in NPH.MethodAn experimental finite element (FE) analysis was used to simulate ventricular dilatation in 3 dimensions (3D) and to calculate the strain and deformation on the surrounding parenchyma. Magnetic resonance diffusion tensor imaging-based white matter tractography was then applied to retrieve the displacement and deformation exerted along various fiber bundles of the corona radiata and internal capsule. Anterior and posterior limb displacements and elongations were compared using a paired samples t-test.ResultsThe internal capsule, hence the corona radiata, of each cerebral hemisphere was segmented into anterior and posterior limbs. Mean displacements and elongations were calculated for each limb. Mean displacement was significantly larger in the anterior limb whereas mean deformation was larger in the posterior limb (P < 0.01).ConclusionThe present simulation demonstrates that ventricular dilatation does not have a homogeneous effect on the periventricular fibre tracts, with a particular load on the corticospinal tract. The affection of this tract remains thereby a potential factor in the generation of the NPH gait disorders.     

手法处理头位难产在少数民族偏远地区的意义

目的 探讨经阴道徒手旋转胎头处理头位难产的临床应用价值.方法 回顾性分析经阴道徒手旋转胎头处理头位难产的病例,分析其异常头先露、先露高低、宫口扩张及胎儿体重与徒手旋转胎头处理后分娩情况.结果 头位难产1356例,占分娩总数的20.56%.对其中1030例孕妇进行了经阴道徒手旋转纠正头先露异常,顺产842例,成功率81.75%;剖宫产141例(13.69%),阴道助产47例(4.56%),失败188例,失败率18.52%.持续性枕后位与枕横位徒手旋转胎头成功率明显高于前不均倾位及高直位(P<0.01);先露S+1以下徒手旋转胎头成功率明显高于S+1以上者(P<0.01);宫口开大4cm以上徒手旋转胎头成功率明显高于宫口开大4cm以下者(P<0.01);胎儿体重3750g以下时,徒手旋转胎头成功率明显高于胎儿体重3750g以上者(P<0.01).结论 重视头盆评分及产程观察,适时经阴道徒手旋转异常头先露,能有效提高头位难产的阴道分娩率,降低剖宫产率,对少数民族偏远地区有重要意义.     

Role of microparticles in recurrent miscarriages and other adverse pregnancies: a review

The multiple functions attributed to microparticles (MPs) include blood coagulation, inflammation, tumorigenesis, angiogenesis, immunomodulatory functions and intercellular cross talk. These have drawn considerable interest during the last few years. The prothrombotic nature of MPs has linked them with almost all groups of thrombotic disorders including recurrent miscarriage (RM) and other abnormal pregnancy outcomes. Two authors (SS and RP) conducted a search independently on the computerized databases MEDLINE and EMBASE using relevant key words. Contradictory reports were observed on the association of MPs with RM. While most of the reports showed increased prevalence of MPs, both platelet and endothelial cell derived, in RM, some did not show any association. Almost all the reports showed a strong association of MPs with preeclampsia (PE), while the association with other adverse pregnancy conditions was not very conclusive. It may be concluded that MPs by themselves may result in adverse conditions or that they may be additive factors to an already existing prothrombotic state due to acquired or genetic thrombophilia or some unknown thrombophilic condition, besides the pre-existing hypercoagulable status of pregnancy.     

Children's Perception of Temporally Distorted Sentential Approximations of Varying Length

The purpose of this study was to investigate the abilities of second-grade and fourth-grade children to auditorially process three orders of three- and five-word sentential approximations, which had normal interstimulus intervals (ISI) and ISIs of 200 and 400 ms. Results showed that percent correct scores decreased as a function of increasing sentence length and ISI, and decreasing order of sentential approximation and grade level. The results are discussed relative to theoretical notions of short-term memory and auditory perceptual processing as well as potential clinical applications     

Dosimetric comparison of IMRT rectal and anal canal plans generated using an anterior dose avoidance structure

To describe a dosimetric method using an anterior dose avoidance structure (ADAS) during the treatment planning process for intensity-modulated radiation therapy (IMRT) for patients with anal canal and rectal carcinomas. A total of 20 patients were planned on the Elekta/CMS XiO treatment planning system, version 4.5.1 (Maryland Heights MO) with a superposition algorithm. For each patient, 2 plans were created: one employing an ADAS (ADAS plan) and the other replanned without an ADAS (non-ADAS plan). The ADAS was defined to occupy the volume between the inguinal nodes and primary target providing a single organ at risk that is completely outside of the target volume. Each plan used the same beam parameters and was analyzed by comparing target coverage, overall plan dose conformity using a conformity number (CN) equation, bowel dose-volume histograms, and the number of segments, daily treatment duration, and global maximum dose. The ADAS and non-ADAS plans were equivalent in target coverage, mean global maximum dose, and sparing of small bowel in low-dose regions (5, 10, 15, and 20 Gy). The mean difference between the CN value for the non-ADAS plans and ADAS plans was 0.04 ± 0.03 (p < 0.001). The mean difference in the number of segments was 15.7 ± 12.7 (p < 0.001) in favor of ADAS plans. The ADAS plan delivery time was shorter by 2.0 ± 1.5 minutes (p < 0.001) than the non-ADAS one. The ADAS has proven to be a powerful tool when planning rectal and anal canal IMRT cases with critical structures partially contained inside the target volume.     

Attentional Dysfunction Associated with Posttraumatic Stress Disorder Among Rape Survivors

Posttraumatic stress disorder (PTSD) is characterized by subjective reports of decreased concentration and an inability to sustain attention. Some empirical validation of these symptoms has been demonstrated via reduced performance on attentional tests among war veterans with PTSD. However, the significance of such findings is unclear given high co-morbidity with other psychiatric, neurologic, and substance abuse disorders among veterans. The present study examined neuropsychological functioning among rape survivors with PTSD, a patient population with comparatively low rates of psychiatric co-morbidity. Rape survivors with PTSD (PTSD+; n = 15) were compared to rape survivors without PTSD (PTSD–; n = 16) and age- and education-matched nontraumatized controls (CTRL; n = 16) on tests of attention. Performance of the PTSD+ group was significantly worse than the other groups on measures of sustained and divided attention, but not on shifting of visuospatial selective attention. Performance differences were not attributable to co-morbid psychiatric disorders or substance abuse. The implications of these findings regarding the effects of trauma on attentional functions are discussed.     

Computed tomography of the orbit – A review and an update

Computed tomography (CT) and magnetic resonance imaging (MRI) of the orbit have been competing for the hearts and minds of health care providers for well over 2 decades. While several drawbacks pertaining to CT have been outlined since the introduction of MRI, CT remains the standard diagnostic test for evaluating cross-sectional, 2 or 3-dimensional images of the body.     

Review: Embryo- and endometrium-derived exosomes and their potential role in assisted reproductive treatments–liquid biopsies for endometrial receptivity

Multiple pregnancies resulting from the transfer of more than one embryo pose a significant threat to offspring born through Assisted Reproductive Treatments (ART). Transferring one embryo at a time would eliminate this risk. However, current approaches of identifying the highest quality embryo to transfer are either unreliable (e.g. morphology assessment) or highly invasive and potentially detrimental to embryos (e.g. PGD). Approaches for non-invasive embryo selection would be a major advancement that would increase efficiency and reduce both the costs and the risks associated with ART. Exosomes are a particular subtype of extracellular vesicles (EVs) that are secreted from a wide range of cells, including placental and endometrium cells. Exosomes are very stable vesicles that contain a broad spectrum of molecules, including proteins, mRNAs and miRNAs. Very little is known about this form of cell-to-cell communication in the context of ovarian follicular biology and implantation, but emerging data suggest that exosomes secreted by the blastocyst could influence gene expression and receptivity of endometrial cells thereby controlling its own implantation. Here we review emerging findings regarding exosomal signalling in reproductive biology and the prospects for mapping blastocyst-derived exosomal profiles as a means for supporting single embryo transfer policies.     

Articular Ultrasound in Asymptomatic Volunteers: Identification of the Worst Measures of Synovial Hypertrophy,Synovial Blood Flow and Joint Damage Among Small-, Medium- and Large-Sized Joints

Articular ultrasound of 6500 joint recesses was performed for the purpose of identifying which joint had the highest measurements among small-sized (SSJ), medium-sized (MSJ) and large-sized (LSJ) joints. Quantitative measurements of synovial hypertrophy (QSR) and semiquantitative measurements of synovial hypertrophy (SSH), power Doppler (SPD) and bone erosion (SBE) (score: 0–3) were made. Higher measurements (p < 0.01) of QSR were obtained in the second metatarsophalangeal joint (MTP), talonavicular joint, and hip. The highest SSH scores (2/3) were obtained in the second MTP, talonavicular joint, hip and knee; the highest SPD scores (1/2/3) in the first MTP, second MTP, dorsal second metacarpophalangeal (MCP) and radiocarpal recesses; and the highest SBE scores (2/3) in the radiocarpal, ulnocarpal and posterior recesses of the glenohumeral joint. In conclusion, higher measurements of synovial hypertrophy were found in the first and second MTPs (SSJ), talonavicular recess (MSJ) and hip (LSJ). Synovial blood flow was frequent in the first MTP and radiocarpal recess. Bone erosion stood out only in the glenohumeral joint.     

Multivariate normal tissue complication probability modeling of vaginal late toxicity after brachytherapy for cervical cancer

PurposeTo explore the best variables combination for a predictive model of vaginal toxicity in cervical cancer patients undergoing brachytherapy (BT).Methods and MaterialsClinical and 3-dimensional dosimetric parameters were retrospectively extracted from an institutional database of consecutive patients undergoing intracavitary BT after external beam radiation therapy from 2006 to 2013 for a cervical cancer. A least absolute shrinkage and selection operator selection procedure in Cox's proportional hazards regression model was performed to select a set of relevant predictors for a multivariate normal tissue complication probability model of Grade ≥2 vaginal late toxicity. Outcomes reliability was internally assessed by bootstrap resampling method.ResultsOne hundred sixty-nine women were included in the present study with a median followup time of 3.8 years (interquartile range [IQR], 1.9–5.6 years). The 2 years and 5 years cumulative incidence rates of Grade ≥2 late vaginal toxicity were 19.9% and 27.5%, respectively. Among 31 metrics and six clinical factors extracted, the optimal model included two dosimetric variables: V70_Gy and D5_% (the percentage volume that received a dose greater or equal to 70 Gy and the minimum dose given to the hottest 5% volume, respectively). Area under the ROC curve at 2 and 5 years of followup were 0.85 and 0.91, respectively. Regarding internal validation, median area under the ROC curve of bootstrap predictions was 0.83 (IQR, 0.78–0.88) and 0.89 (IQR, 0.85–0.93) at 2 and 5 years of followup, respectively.ConclusionsA multivariate normal tissue complication probability model for severe vaginal toxicity based on two dosimetric variables (V70_Gy and D5_%) provides reliable discrimination capability in a cohort of cervical cancer treated with external beam radiation therapy and BT.