Spatial distribution of human arachnoid trabeculae

Traumatic brain injury (TBI) is a common injury modality affecting a diverse patient population. Axonal injury occurs when the brain experiences excessive deformation as a result of head impact. Previous studies have shown that the arachnoid trabeculae (AT) in the subarachnoid space significantly influence the magnitude and distribution of brain deformation during impact. However, the quantity and spatial distribution of cranial AT in humans is unknown. Quantification of these microstructural features will improve understanding of force transfer during TBI, and may be a valuable dataset for microneurosurgical procedures. In this study, we quantify the spatial distribution of cranial AT in seven post-mortem human subjects. Optical coherence tomography (OCT) was used to conduct in situ imaging of AT microstructure across the surface of the human brain. OCT images were segmented to quantify the relative amounts of trabecular structures through a volume fraction (VF) measurement. The average VF for each brain ranged from 22.0% to 29.2%. Across all brains, there was a positive spatial correlation, with VF significantly greater by 12% near the superior aspect of the brain (p < .005), and significantly greater by 5%−10% in the frontal lobes (p < .005). These findings suggest that the distribution of AT between the brain and skull is heterogeneous, region-dependent, and likely contributes to brain deformation patterns. This study is the first to image and quantify human AT across the cerebrum and identify region-dependencies. Incorporation of this spatial heterogeneity may improve the accuracy of computational models of human TBI and enhance understanding of brain dynamics.     

Knowledge,attitudes and practices regarding COVID-19 among dental health care professionals: a cross-sectional study in Saudi Arabia

ObjectivesWith the increasing severity of the coronavirus disease (COVID-19) pandemic, it is essential that dental health care professionals (DHCPs) are prepared. The study aim was to assess the knowledge, attitudes and practices (KAP) regarding COVID-19 among DHCPs in Saudi Arabia.MethodsA cross-sectional study using a web-based survey was conducted. A validated and reliable questionnaire was developed that comprised 44 questions. Using Qualtrics survey software, DHCPs working in different settings were approached across five geographical regions of Saudi Arabia.ResultsA total of 318 respondents voluntarily participated in the survey. Most DHCPs showed a moderate level of knowledge (51.6%), a positive attitude (92.1%) and adequate practice standards (86.5%). We found that 94.7% of DHCPs had an adequate overall level of KAP. DHCPs with a doctorate significantly outscored DHCPs with other educational levels with respect to knowledge and practice. Older (51–60 years) DHCPs reported significantly more knowledge than younger DHCPs.ConclusionDHCPs displayed an average level of knowledge that needs to be enhanced through continuing education programmes. However, they showed a positive attitude and an acceptable level of practice, as they were abiding by guidelines issued from various international and national health agencies.     

Relationships between TIMP-1, CAIX,and clinical outcomes in Egyptian breast cancer

Serum levels of carbonic anhydrase IX (CAIX) and the tissue inhibitor of metalloproteinase 1 (TIMP-1) have been demonstrated to be associated with clinical outcomes. Elevated TIMP-1 levels have been associated with a poor prognosis of breast cancer. Therefore, this study was performed to explore the relationships between serum CAIX, TIMP-1, and clinical outcomes. One hundred and five female breast cancer patients, who do not receive adjuvant therapy at Mansoura University Hospital were recruited with informed consent for this study. Preoperative serum levels of CAIX and TIMP-1 were measured using an enzyme-linked immunosorbent assay. Among the breast cancer patients, 16.1 and 20.9 % had elevated TIMP-1 and CAIX l levels, respectively. In addition, 13.3 % had elevated both CAIX and TIMP-1 levels. Elevated serum levels CAIX was significantly associated with advanced histological grade, estrogen receptor status and progesterone receptor status. Moreover, Elevated TIMP-1 was significantly associated with number of tumor-positive lymph nodes and advanced histological grade. In Kaplan–Meier analysis, the disease-free survival (DFS) was lower in patients with high serum levels of CAIX and TIMP-1 compared to patients with normal serum concentration of CAIX and TIMP-1. Including TIMP-1, CAIX, and established prognostic factors in the multivariate analysis, the presence of elevated CAIX and TIMP-1 levels remained independent predictors of overall survival time (OS). A high serum TIMP-1 and CAIX levels were significantly associated with poorer DFS and OS among Egyptian primary breast cancer patients with elevated serum levels of CAIX and TIMP-1.     

Transesophageal Echocardiography of Intracardiac Thrombus in Congenital Heart Disease and Atrial Flutter: The Importance of Thorough Examination of the Fontan

Transesophageal echocardiography (TEE) is used in atrial flutter or fibrillation (AFF) before electric cardioversion to detect intracardiac thrombi. Previous studies have described the use of TEE to diagnose intracardiac thrombi in the left atrium and left atrial appendage, which has an incidence of 8 % among patients without congenital heart disease (CHD). In their practice the authors have noted a significant incidence of intracardiac thrombi in other structures of patients with CHD and AFF. This study aimed to determine the incidence and location of intracardiac thrombi using TEE in patients with CHD requiring electric cardioversion of AFF and to compare the use of TEE and transthoracic echo (TTE) to detect intracardiac thrombus in this population. A retrospective chart review of TEE and TTE findings for all patients with CHD who had electric cardioversion of AFF at our institution from 2005 to 2013 was conducted. The diagnosis, presence, and location of intracardiac thrombus were determined. The TEE and TTE results were compared. The study identified 27 patients with CHD who met the study entry criteria at our institution between 2005 and 2013. Seven of these patients had a single ventricle with Fontan palliation. All the patients presented with AFF and had TEE before electric cardioversion. No patients were excluded from the study. The patients ranged in age from 2 to 72 years (median, 21 years) and weighed 17–100 kg (median, 65 kg). The duration of AFF before TEE and attempted cardioversion ranged from 1 day to 3 weeks (median, 3.5 days). Intracardiac thrombus was present in 18 % (5/27) of the patients and in 57 % (4/7) of the Fontan patients with AFF. No embolic events were reported acutely or during a 6-month follow-up period. Among patients with CHD who present with AFF, a particularly high incidence of intracardiac thrombi is present in the Fontan patients that may be difficult to detect by TTE. Thorough TEE examination of the Fontan and related structures is indicated before electric cardioversion of AFF. The incidence of intracardiac thrombus in CHD patients is more than double that reported in non-CHD patients.     

The effect of ubiquinone on functional recovery and morphometric indices of sciatic nerve regeneration

A common cause of peripheral nerve injury is trauma. The positive effect of antioxidants on the improvement of nerve regeneration has currently become a focus of attention. In this experiment, the effect of intraperitoneal administration of ubiquinone (CoQ₁₀) on an acute experimentally sciatic nerve crush was studied in a rat model. Forty-five male Wistar rats, weighing between 160-180 g were used. The rats were randomly divided into two experimental groups (n=20). Each group was further subdivided into four subgroups of five animals each. Functional studies confirmed the faster recovery of regenerated axons in the treatment group compared to the un-treated group (P<0.05). Morphometric indices of the regenerated fibers showed the number and diameter of the myelinated fibers to be significantly higher in the treatment group than the un-treated group (P<0.05). Intraperitoneal administration of CoQ₁₀ (10 mg/kg/day) in the early inflammatory stage of sciatic nerve crush was found to improve nerve regeneration.Key Words: Ubiquinone (coenzyme Q₁₀), Peripheral nerve regeneration, Crush     

Identification of novel variants in Iranian consanguineous pedigrees with nonsyndromic hearing loss by next-generation sequencing

BackgroundThe extremely high genetic heterogeneity of hearing loss due to diverse group of genes encoding proteins required for development, function, and maintenance of the complex auditory system makes the genetic diagnosis of this disease challenging. Up to now, 121 different genes have been identified for nonsyndromic hearing loss (NSHL), of which 76 genes are responsible for the most common forms of NSHL, autosomal recessive nonsyndromic hearing loss (ARNSHL).MethodsAfter excluding mutations in the most common ARNSHL gene, GJB2, by Sanger sequencing, genetic screening for a panel of genes responsible for hereditary hearing impairment performed in 9 individuals with ARNSHL from unrelated Iranian consanguineous pedigrees.ResultsOne compound heterozygote and eight homozygote variants, of which five are novel, were identified: CDH23:p.(Glu1970Lys), and p.(Ala1072Asp), GIPC3:p.(Asn82Ser), and (p.Thr41Lys), MYO7A:p.[Phe456Phe]; p.[Met708Val], and p.(Gly163Arg), TECTA:p.(Leu17Leufs*19), OTOF:c.1392+1G>A, and TRIOBP:p.(Arg1068*). Sanger sequencing confirmed the segregation of the variants with the disease in each family.ConclusionFinding more variants and expanding the spectrum of hearing impairment mutations can increase the diagnostic value of molecular testing in the screening of patients and can improve counseling to minimize the risk of having affected children for at risk couples.     

Salivary duct carcinoma presenting with vaginal metastasis: case report

Vaginal cancer represents about 1-2% of the genital tract malignancies. Most cases represent metastasis from the cervix, endometrium or colon. Metastasis of salivary duct carcinoma to the vagina has not been previously reported. Salivary duct carcinoma (SDC) is a rare, highly aggressive tumor that most often involves the parotid gland. On presentation, SDC is metastasized to the regional lymph nodes in about 40% of cases. We report a case of metastatic salivary duct carcinoma presenting as a vaginal mass with bleeding. Diagnosis was confirmed by the histological appearance in addition to immunohistochemistry. To our knowledge this is the first reported case of vaginal metastasis from SDC. Small-sized primaries might be ignored by the patient, specially in the older age group, probably due to lack of manifesting symptoms like pain and bleeding. Some cancers, like SDC, have various histologic patterns in different areas of the tumor. Careful examinations of multiple sections, in addition to an immunohistochemical panel, and histologic comparison of all lesions are keys to a correct diagnosis.     

Effective Range of FSSW Parameters for High Load-Carrying Capacity of Dissimilar Steel A283M-C/Brass CuZn40 Joints

In the current study, a 2 mm thick low-carbon steel sheet (A283M—Grade C) was joined with a brass sheet (CuZn40) of 1 mm thickness using friction stir spot welding (FSSW). Different welding parameters including rotational speeds of 1000, 1250, and 1500 rpm, and dwell times of 5, 10, 20, and 30 s were applied to explore the effective range of parameters to have FSSW joints with high load-carrying capacity. The joint quality of the friction stir spot-welded (FSSWed) dissimilar materials was evaluated via visual examination, tensile lap shear test, hardness test, and macro- and microstructural investigation using SEM. Moreover, EDS analysis was applied to examine the mixing at the interfaces of the dissimilar materials. Heat input calculation for the FSSW of steel–brass was found to be linearly proportional with the number of revolutions per spot joint, with maximum heat input obtained of 11 kJ at the number of revolutions of 500. The temperature measurement during FSSW showed agreement with the heat input dependence on the number of revolution. However, at the same revolutions of 500, it was found that the higher rotation speed of 1500 rpm resulted in higher temperature of 583 °C compared to 535 °C at rotation speed of 1000 rpm. This implies the significant effect for the rotation speed in the increase of temperature. The macro investigations of the friction stir spot-welded joints transverse sections showed sound joints at the different investigated parameters with significant joint ligament between the steel and brass. FSSW of steel/brass joints with a number of revolutions ranging between 250 to 500 revolutions per spot at appropriate tool speed range (1000–1500 rpm) produces joints with high load-carrying capacity from 4 kN to 7.5 kN. The hardness showed an increase in the carbon steel (lower sheet) with maximum of 248 HV and an increase of brass hardness at mixed interface between brass and steel with significant reduction in the stir zone hardness. Microstructural investigation of the joint zone showed mechanical mixing between steel and brass with the steel extruded from the lower sheet into the upper brass sheet.     

Comparison of Clinical and Echocardiographic Outcomes After Surgical Redo Mitral Valve Replacement and Transcatheter Mitral Valve-in-Valve Therapy

Objectives

There are minimal data regarding clinical outcomes and echocardiographic findings after transcatheter mitral valve-in-valve replacement (TMVR) compared with redo surgical mitral valve replacement (SMVR).