Pressure Points Technique for Traumatic Proximal Axillary Artery Hemorrhage: A Case Report.

INTRODUCTION: While the pressure points technique for proximal hemorrhage control is long known, it is not recommended in standard prehospital guidelines based on a study showing the inability to maintain occlusion for over two minutes. MAIN SYMPTOM: This report details a gunshot wound to the left axillary area with complete transection of the axillary artery, leading to profuse junctional hemorrhage and profound hemorrhagic shock. THERAPEUTIC INTERVENTION: Proximal pressure of the subclavian artery was applied against the first rib (the pressure points technique) and maintained for 28 minutes. OUTCOMES: Cessation of apparent bleeding and excellent, enduring physiologic response to blood transfusion were observed. CONCLUSION: The pressure points technique can be life-saving in junctional arterial hemorrhage and should be reconsidered in prehospital guidelines.

Isolated Versus Non-isolated Traumatic Brain Injuries Identification and Decision Making: A Comparative Study.

BACKGROUND: Traumatic brain injury (TBI) is a significant cause of death in the battlefield. TBI can be challenging to diagnose in the combat setting and remains a substantial challenge for advanced life support (ALS) providers. OBJECTIVES: To compare prehospital and hospitalization characteristics between isolated and non-isolated TBI. To examine the effects of TBI with coexisting injuries on patient evaluation and outcomes based on the Israeli Defense Forces Trauma Registry and the Israeli National Trauma Registry of soldiers hospitalized for TBI between the years 2006-2017. METHODS: A total of 885 casualties were eligible for our study, of whom 271 (30%) had isolated TBI. Only 35% of hospitalized patients with isolated TBI were defined as urgent by the ALS providers versus 67% in the non-isolated TBI group (P < 0.001). RESULTS: Overall, 29% of the TBIs in the non-isolated group were missed by the ALS providers vs. 11% in the isolated group. CONCLUSIONS: Concomitant injuries may delay the diagnosis of TBI by ALS providers. These findings should be considered in the prehospital evaluation to potentially improve the care and outcome of head injury patients.

SARS-CoV-2 Vaccine Acceptance Disparity Among Israeli Defense Forces Personnel.

INTRODUCTION: Promoting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine acceptance and uptake became necessary to achieve a high vaccination rate and subsequently herd immunity. Although the Israeli population has been largely acceptant of the SARS-CoV-2 vaccine, vaccine hesitancy has remained a major concern, especially in younger adults. We hypothesized that young adults who refused SARS-CoV-2 vaccination differed from those who have been adherent and could be characterized. Studying this specific population and recognizing individuals within this group who might be more probable to refuse vaccination can enable to target measures to further promote vaccination acceptance. METHODS: We conducted a cross-sectional comparison in a study population comprised of 17,435 Israeli Defense Forces (IDF) personnel who were SARS-CoV-2 vaccine eligible. This group included 14,834 vaccinated and 2,601 nonvaccinated individuals. Patient characteristics including occupational parameters, demographic features, psychotechnical grading (an intelligence assessment score), education level, and medical background were collected. RESULTS: The median age was 20.57 years and almost 80% were males. At the time of data collection, most individuals (85.1%, n = 14,834) have been vaccinated. Officers and noncommissioned officers were more likely to be vaccinated compared with regular soldiers (96%, and 90.2% vs. 83.3% respectively, P < .001), as well as combat battalions stationed personnel compared to their peers in rear and administrative units (89.4% vs. 78.4%, P < .001). Socioeconomic clusters were also associated with vaccination adherence, with 92.9% vs. 79.5% vaccination rates in the highest and lowest clusters, respectively (P < .001). Younger age, no previous immigration status, higher education level, and higher psychotechnical grades were also found associated with an increased likelihood of being vaccinated (P < .001). CONCLUSIONS: In a large cohort of enlisted IDF personnel, disparity in SARS-CoV-2 vaccine adherence was found to be related to multiple socioeconomic, educational, and military service-related variables. Although some differences were substantial, others were small and of questionable public health significance. Acknowledging these differences may enable community leaders, health care providers, and administrators to target specific populations in order to further promote SARS-CoV-2 vaccination acceptance.

Promoting Compliance to COVID-19 Vaccination in Military Units.

BACKGROUND: On December 27th, 2020, the Israeli Defense Forces initiated a mass COVID-19 vaccination campaign aiming to vaccinate its personnel. This population upheld specific characteristics in terms of age and sex, lack of significant comorbidities, and a general scarcity of risk factors for sustaining a severe COVID-19 illness. We present the measures taken to increase vaccination compliance, and the vaccination rate that followed these actions. Our secondary goal was to compare between vaccination rates in frontline battalions and highly essential military units (group A) and rear administration and support military units (group B). METHODS: This was a retrospective review that included 70 military units that were composed of 18,719 individuals of both sexes, mostly free of significant comorbidities. We divided the challenges of maximizing vaccination rates into two main categories: vaccine compliance (including communication and information) and logistical challenges. We compared the vaccination rates in groups A and B using a multivariable linear regression model. A P-value of .05 was considered significant. RESULTS: The mean age in 70 military units was 22.77 ± 1.35 (range 18-50) years, 71.13% males. A total of 726 (3.88%) individuals have been found positive for SARS-CoV-2 between March 1st, 2020 and February 18th, 2021. On February 18th, 2021, 54 days after the vaccination campaign was launched, 15,871 (84.79%) of the study population have been vaccinated by the first dose of Pfizer COVID-19 vaccine, expressing an 88.21% compliance rate (excluding recovered COVID-19 cases who were not prioritized to be vaccinated at this stage). Vaccination compliance in military units from group A was found to be higher when compared to group B (P < .001), leading to a 90.02% of group A population being either previously SARS-CoV-2 positive or COVID-19 vaccinated. CONCLUSIONS: A designated army campaign led by a multidisciplinary team could rapidly achieve a high COVID-19 vaccination rate. The information presented can serve organizations worldwide with similar characteristics that plan a mass COVID-19 vaccination campaign.

Intradiscal quantitative chemical exchange saturation transfer MRI signal correlates with discogenic pain in human patients.

Low back pain (LBP) is often a result of a degenerative process in the intervertebral disc. The precise origin of discogenic pain is diagnosed by the invasive procedure of provocative discography (PD). Previously, we developed quantitative chemical exchange saturation transfer (qCEST) magnetic resonance imaging (MRI) to detect pH as a biomarker for discogenic pain. Based on these findings we initiated a clinical study with the goal to evaluate the correlation between qCEST values and PD results in LBP patients. Twenty five volunteers with chronic low back pain were subjected to T2-weighted (T2w) and qCEST MRI scans followed by PD. A total of 72 discs were analyzed. The average qCEST signal value of painful discs was significantly higher than non-painful discs (p = 0.012). The ratio between qCEST and normalized T2w was found to be significantly higher in painful discs compared to non-painful discs (p = 0.0022). A receiver operating characteristics (ROC) analysis indicated that qCEST/T2w ratio could be used to differentiate between painful and non-painful discs with 78% sensitivity and 81% specificity. The results of the study suggest that qCEST could be used for the diagnosis of discogenic pain, in conjunction with the commonly used T2w scan.

Socio-demographic disparities in amblyopia prevalence among 1.5 million adolescents.

BACKGROUND: Amblyopia, when not diagnosed at appropriate age, leads to uncorrectable visual impairment with considerable social and financial implications. The aim of this study was to assess socio-demographic disparities in amblyopia prevalence among Israeli adolescents, in order to identify susceptible groups in the population. METHODS: A nationwide, population-based, cross-sectional study of Israeli adolescents examined between 1993 and 2017. All study participants underwent visual acuity examination with socio-demographic data and previous medical history documented. Associations were analyzed using univariable and multivariable logistic regression models. RESULTS: Among 1 334 650 Israeli-born candidates aged 17.15±0.26 years, amblyopia was diagnosed in 1.07%. The overall prevalence of amblyopia has declined from 1.59% in 1993 to 0.87% in 2017. Being in the lowest socioeconomic status and below average cognitive function scores increased the odds of amblyopia in both males [odds ratio (OR) 1.64, 95% confidence interval (CI) 1.45-1.87; OR 1.27, 95% CI 1.19-1.35, respectively] and females (OR 1.61, 95% CI 1.30-1.98; OR 1.27, 95% CI 1.18-1.36, respectively). Among males, Orthodox and ultra-Orthodox educational systems were associated with increased odds of amblyopia (OR 1.16, 95% CI 1.09-1.25; OR 1.90, 95% CI 1.73-2.09). A significantly higher prevalence of amblyopia was recorded among 219 983 immigrants (1.51%, P<0.001). CONCLUSIONS: Although the overall prevalence of amblyopia has decreased during the observed years, we found substantial evidence of socio-demographic disparities in amblyopia prevalence among adolescents, suggesting disparities in the prevention of the disease and its treatment. Demonstration of inequities at a national level could aid future guidance of health policy and augment current vision screening programs.

The volume of general surgery emergency cases in a government hospital during the COVID-19 pandemic and two other periods: a comparative, retrospective study.

BACKGROUND: During March and April 2020, reductions in non-COVID-19 hospital admissions were observed around the world. Elective surgeries, visits with general practitioners, and diagnoses of medical emergencies were consequently delayed. OBJECTIVE: To compare the characteristics of patients admitted to a northern Israeli hospital with common surgical complaints during three periods: the lockdown due to the COVID-19 outbreak, the Second Lebanon War in 2006, and a regular period. METHODS: Demographic, medical, laboratory, imaging, intraoperative, and pathological data were collected from electronic medical files of patients who received emergency treatment at the surgery department of a single hospital in northern Israel. We retrospectively compared the characteristics of patients who were admitted with various conditions during three periods. RESULTS: Patients' mean age and most of the clinical parameters assessed were similar between the periods. However, pain was reportedly higher during the COVID-19 than the control period (8.7 vs. 6.4 on a 10-point visual analog scale, P < 0.0001). During the COVID-19 outbreak, the Second Lebanon War, and the regular period, the mean numbers of patients admitted daily were 1.4, 4.4, and 3.0, respectively. The respective mean times from the onset of symptoms until admission were 3, 1, and 1.5 days, P < 0.001. The respective proportions of surgical interventions for appendiceal disease were 95%, 96%, and 69%; P = 0.03. CONCLUSIONS: Compared to a routine period, patients during the COVID-19 outbreak waited longer before turning to hospitalization, and reported more pain at arrival. Patients during both emergency periods were more often treated surgically than non-operatively.

Emergency open surgery with a duodenotomy and successful removal of an impacted basket following a complicated endoscopic retrograde cholangiopancreatography procedure: a case report.

BACKGROUND: Current management of choledocholithiasis entails the use of endoscopic retrograde cholangiopancreatography (ERCP) and clearance of the common bile duct. A rare complication of this procedure is the impaction of the basket by a large stone, which necessitates lithotripsy. Here we report a case of an impacted basket during ERCP, which was managed by open surgery with a duodenotomy and the manual removal of the basket. CASE PRESENTATION: A 79-year-old Caucasian man was admitted to our department with yellowish discoloration of urine, skin and eyes. Abdominal ultrasonography showed a slightly thickened gallbladder, multiple gallbladder stones, dilated intrahepatic bile ducts and extrahepatic bile extending to 1.1 cm. A computed tomography (CT) scan demonstrated a stone in the common bile duct, which caused dilation of the biliary ducts. The patient was diagnosed with obstructive jaundice secondary to choledocholithiasis; and underwent an ERCP, a sphincterotomy and stone extraction. Four days following discharge, the patient was readmitted with jaundice, abdominal pain, vomiting and fever. He was diagnosed with ascending cholangitis and treated initially with antibiotics. A second ERCP revealed a dilated common bile duct and choledocholithiasis. Stone removal with a basket failed, as did mechanical lithotripsy. Finally, the wires of the basket were ruptured and stacked in the common bile duct together with the stone. During exploratory laparotomy, adhesiolysis, a Kocher maneuver of the duodenum and a subtotal cholecystectomy were performed. Choledochotomy did not succeed in removing the impacted wires together with the stone. Therefore, a duodenotomy and an extension of the sphincterotomy were performed, followed by high-pressure lavage of the common bile duct to remove additional small biliary stones. The choledochotomy and duodenotomy were closed by a one-layer suture, and a prophylactic gastroenterostomy was performed to prevent leakage from the common bile duct and the duodenum. The postoperative course was satisfactory. CONCLUSIONS: This is the first report in the literature of removal of an impacted Dormia basket through the papilla by performing a duodenotomy and an extension of the sphincterotomy, followed by gastroenterostomy.

Microsurgery for management of primary and secondary lymphedema.

OBJECTIVE: The objective of this study was to evaluate the efficacy and safety of lymphaticovenular anastomosis (LVA) in patients with lymphedema. METHODS: A retrospective analysis was conducted of 70 patients suffering from primary or secondary lymphedema who underwent LVA surgery with indocyanine green fluorescence lymphangiography. Postoperative evaluation included qualitative and quantitative volumetric assessment and analysis. Limb volume was measured by circumferential tape measurement volumetric method, in which the limb is subdivided into five segments and each segment's circumference is measured. RESULTS: LVA was performed in 70 patients, 22 with primary lymphedema and 48 with secondary lymphedema. The difference in preoperative upper limb volume was 35% with mean postoperative follow-up of 9 months. The mean number of lymphovenous bypasses was 3.9. The reduction in limb volume at 3, 6, and 12 months was 40.4%, 41%, and 45%, respectively. Patients with early-stage lymphedema had significantly higher volume reductions than patients with late-stage lymphedema at 3, 6, and 12 months (48% vs 18%, 49% vs 22%, and 65% vs 31%; P < .001). For lower extremity lymphedema, the preoperative volume differential was 25.5%. The mean postoperative follow-up was 9 months. The reduction in limb volume at 3, 6, and 12 months was 28%, 37%, and 39%, respectively. CONCLUSIONS: LVA surgery is a safe and effective method of reducing lymphedema severity, especially in upper extremity lymphedema at an earlier disease stage.

Robotic inguinal hernia repair: Is it a new era in the management of inguinal hernia?

OBJECTIVE: We compared outcomes of elective inguinal hernia repair performed at one institution by three approaches: robotic-assistance, laparoscopic, and open. METHODS: Characteristics of the patients, the hernia and the procedures performed during 2014-2016 were accessed from patient electronic medical files of 137 elective inguinal hernia repairs. 24 surgeries were robotic-assisted, 16 laparoscopic and 97 open repairs. RESULTS: Distributions of age, sex and BMI did not differ between the groups. Bilateral repair was more common in the robotic (70.8%) than the laparoscopic (50.0%) and open groups (12.4%) (p < 0.001). Direct hernias were more common in the open (45.4%) than the robotic (20.8%) and laparoscopic (12.5%) groups (p < 0.001). Only 3 hernias were inguinoscrotal, all in the robotic group. The median operation times were 44.0, 79.0 and 92.5 min for the open, laparoscopic and robotic methods, respectively (p < 0.001). Among the unilateral repairs, the median operative times were the same for the robotic and laparoscopic procedures, 73 min, and less for the open procedures, 40 min. The proportion of patients hospitalized for 2-3 days was higher for open repair (13.4% vs. 6.2% and 0% for laparoscopic and robotic), but this difference was not statistically significant. The median maximal postoperative pain according to a 0-10-point visual analogue score was 5.0, 2.0 and 0 for open, laparoscopic and robotic procedures, respectively (p < 0.001). CONCLUSIONS: This report demonstrated the safety and feasibility of robotic-assisted inguinal hernia repair.

Continuous Monitoring of Mental Load During Virtual Simulator Training for Laparoscopic Surgery Reflects Laparoscopic Dexterity: A Comparative Study Using a Novel Wireless Device.

INTRODUCTION: Cognitive Load Theory (CLT) relates to the efficiency with which individuals manipulate the limited capacity of working memory load. Repeated training generally results in individual performance increase and cognitive load decrease, as measured by both behavioral and neuroimaging methods. One of the known biomarkers for cognitive load is frontal theta band, measured by an EEG. Simulation-based training is an effective tool for acquiring practical skills, specifically to train new surgeons in a controlled and hazard-free environment. Measuring the cognitive load of young surgeons undergoing such training can help to determine whether they are ready to take part in a real surgery. In this study, we measured the performance of medical students and interns in a surgery simulator, while their brain activity was monitored by a single-channel EEG. METHODS: A total of 38 medical students and interns were divided into three groups and underwent three experiments examining their behavioral performances. The participants were performing a task while being monitored by the Simbionix LAP MENTOR™. Their brain activity was simultaneously measured using a single-channel EEG with novel signal processing (Aurora by Neurosteer®). Each experiment included three trials of a simulator task performed with laparoscopic hands. The time retention between the tasks was different in each experiment, in order to examine changes in performance and cognitive load biomarkers that occurred during the task or as a result of nighttime sleep consolidation. RESULTS: The participants' behavioral performance improved with trial repetition in all three experiments. In Experiments 1 and 2, delta band and the novel VC9 biomarker (previously shown to correlate with cognitive load) exhibited a significant decrease in activity with trial repetition. Additionally, delta, VC9, and, to some extent, theta activity decreased with better individual performance. DISCUSSION: In correspondence with previous research, EEG markers delta, VC9, and theta (partially) decreased with lower cognitive load and higher performance; the novel biomarker, VC9, showed higher sensitivity to lower cognitive load levels. Together, these measurements may be used for the neuroimaging assessment of cognitive load while performing simulator laparoscopic tasks. This can potentially be expanded to evaluate the efficacy of different medical simulations to provide more efficient training to medical staff and measure cognitive and mental loads in real laparoscopic surgeries.

The Association Between Keratoconus and Body Mass Index: A Population-Based Cross-Sectional Study Among Half a Million Adolescents.

PURPOSE: To analyze the association between keratoconus and body mass index (BMI) among adolescents. DESIGN: Cross sectional study. METHODS: This was a nationwide, population-based study of candidates for military service in Israel attending the draft board in 2006 to 2014 who underwent an ophthalmologic examination. The study population included 579,946 males and females between 16 and 19.9 years of age. Subjects were divided into 4 groups based on adjusted BMI percentiles: underweight (8.3%), normal weight (73.9%), overweight (10.7%), and obese (7.1%). The odds for having keratoconus were compared with the normal weight group. The primary outcome measure was the odds ratio (OR) for the association between BMI groups and keratoconus. RESULTS: The prevalence of keratoconus in the general population was 164 cases per 100,000, increasing over time (P < .05). There was a greater prevalence of keratoconus among obese adolescents (270/100,000) than of overweight (179/100,000), normal weight (154/100,000), and underweight (141/100,000) adolescents. Compared with the normal weight group, the OR for obese adolescents was 1.50 (95% confidence interval [CI] 1.22-1.83; P < .05), the OR for overweight adolescents was 1.42 (95% CI 1.08-1.92; P < .05), and the OR for underweight adolescents was 0.84 (95% CI 0.65-1.09; P = .18) after adjustment for gender, age, height, country of origin, and socioeconomic status. CONCLUSIONS: This study provides strong evidence regarding the independent association between BMI and keratoconus. Overweight and obese adolescents have higher odds of having keratoconus compared with normal weight adolescents. BMI should be considered a risk factor for keratoconus and further research should elucidate how obesity is involved in the progress of keratoconus.

Association of Myopia with cognitive function among one million adolescents.

BACKGROUND: Myopia is a leading cause of visual impairment worldwide, and its increasing incidence is of public health concern. Cognitive function was associated with myopia among children, but evidence for adolescents is scarce. The purpose of this study was to determine whether myopia is associated with cognitive function, and which cognitive ability, verbal or non-verbal, is involved. METHODS: We conducted a population-based cross-sectional study of 1,022,425 Israeli candidates for military service aged 16.5-18 years. Participants underwent a comprehensive battery of tests assessing verbal and non-verbal intelligence, which yields a summarized cognitive function score (CFS). In addition, subjective visual acuity examination followed by objective non-cycloplegic refraction was carried out for each participant. Association between myopia and cognitive function was evaluated by multivariable logistic regression models adjusted for gender, age, country of origin, socioeconomic status, years of education, body mass index, height and year of examination. RESULTS: Compared to the intermediate CFS of the entire cohort, participants who had the highest CFS had 1.85-fold (95% CI, 1.81 to 1.89; P < .001) higher odds of having myopia and 2.73-fold (95% CI, 2.58 to 2.88; P < .001) higher odds of high myopia, while participants with the lowest CFS had 0.59-fold (95% CI, 0.57 to 0.61, P < .001) lower odds of having myopia. The verbal components of the cognitive function assessment had stronger associations with myopia than the non-verbal components (P < .001, for all). CONCLUSIONS: Cognitive function, especially verbal intelligence, is strongly and consistently associated with myopia among adolescents.

Chylous ascites as a late complication of one anastomosis gastric bypass-minigastric bypass: case report.

BACKGROUND: One anastomosis gastric bypass- minigastric bypass (OAGB-MGB) is an emerging bariatric surgery that is being endorsed by surgeons worldwide. Internal herniation is a rare and dreaded complication after malabsorptive bariatric procedures, which necessitates early diagnosis and intervention. CASE PRESENTATION: We describe a 29-year-old male with chylous ascites caused by an internal hernia 8 months following laparoscopic one anastomosis gastric bypass. An abdominal CT showed enlargement of lymph nodes at the mesentery, with a moderate amount of liquid in the abdomen and pelvis. An emergent exploratory laparoscopic surgery demonstrated an internal hernia at the Petersen's space with a moderate quantity of chylous ascites. The patient made an uneventful recovery after surgery. CONCLUSIONS: Internal herniation can occur after OAGB-MGB and in extremely rare cases lead to chylous ascites. To our knowledge, this is the first reported case of chylous ascites following one anastomosis gastric bypass.

A unusual case of multifocal pyogenic abscess formation following ERCP procedure.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is essential for managing biliary and pancreatic disorders. Infection is the most morbid complication of ERCP and among the most common causes of ERCP-related death. CASE PRESENTATION: A 69-year-old man presented with right upper quadrant abdominal pain, obstructive jaundice and abnormal liver function tests. Ultrasound revealed cholelithiasis without bile duct dilation. After receiving intravenous antibiotics for acute cholecystitis, the patient was discharged. Two weeks later, an endoscopic ultrasound demonstrated gallstones and CBD dilation of up to 6.4 mm with 2 filling defects. An ERCP was performed with a papillotomy and stone extraction. Twenty-four hours post-ERCP the patient developed a fever, chills, bilirubinemia and elevated liver function tests. Ascending cholangitis was empirically treated using Ceftriaxone and Metronidazole. However, the patient remained febrile, with a diffusely tender abdomen and elevated inflammatory markers. A CT revealed a very small hypodense lesion in the seventh liver segment. Extended-spectrum beta-lactamase positive Klebsiella Pneumonia and Enterococcus Hirae were identified, and the antibiotics were switched to Imipenem and Cilastatin. The hypodense lesion in the liver increased to 1.85 cm and a new hypodense lesion was seen in the right psoas. At day 10 post-ERCP, the patient started having low back pain and difficulty walking. MRI revealed L4-L5 discitis with a large epidural abscess, spanning L1-S1 and compressing the spinal cord. Decompressive laminectomy of L5 was done and Klebsiella pneumonia was identified. Due to continued drainage from the wound, high fever, we performed a total body CT which revealed increased liver and iliopsoas abscess. Decompressive laminectomy was expanded to include L2-L4 and multiple irrigations were done. Gentamycin and Vancomycin containing polymethylmethacrylate beads were implanted locally and drainage catheters were placed before wound closure. Multidisciplinary panel discussion was performed, and it was decided to continue with a non invasive approach . CONCLUSIONS: Early recognition of complications and individualized therapy by a multi-disciplined team is important for managing post-ERCP septic complications. Particular attention should be given to adequate coverage by empiric antibiotics.

BMP gene delivery for skeletal tissue regeneration.

Musculoskeletal disorders are common and can be associated with significant morbidity and reduced quality of life. Current treatments for major bone loss or cartilage defects are insufficient. Bone morphogenetic proteins (BMPs) are key players in the recruitment and regeneration of damaged musculoskeletal tissues, and attempts have been made to introduce the protein to fracture sites with limited success. In the last 20 years we have seen a substantial progress in the development of various BMP gene delivery platforms for several conditions. In this review we cover the progress made using several techniques for BMP gene delivery for bone as well as cartilage regeneration, with focus on recent advances in the field of skeletal tissue engineering. Some methods have shown success in large animal models, and with the global trend of introducing gene therapies into the clinical setting, it seems that the day in which BMP gene therapy will be viable for clinical use is near.

Human iPSCs can be differentiated into notochordal cells that reduce intervertebral disc degeneration in a porcine model.

Introduction: As many as 80% of the adult population experience back pain at some point in their lifetimes. Previous studies have indicated a link between back pain and intervertebral disc (IVD) degeneration. Despite decades of research, there is an urgent need for robust stem cell therapy targeting underlying causes rather than symptoms. It has been proposed that notochordal cells (NCs) appear to be the ideal cell type to regenerate the IVD: these cells disappear in humans as they mature, are replaced by nucleus pulposus (NP) cells, and their disappearance correlates with the initiation of degeneration of the disc. Human NCs are in short supply, thus here aimed for generation of notochordal-like cells from induced pluripotent cells (iPSCs). Methods: Human iPSCs were generated from normal dermal fibroblasts by transfecting plasmids encoding for six factors: OCT4, SOX2, KLF4, L-MYC, LIN28, and p53 shRNA. Then the iPSCs were treated with GSK3i to induce differentiation towards Primitive Streak Mesoderm (PSM). The differentiation was confirmed by qRT-PCR and immunofluorescence. PSM cells were transfected with Brachyury (Br)-encoding plasmid and the cells were encapsulated in Tetronic-tetraacrylate-fibrinogen (TF) hydrogel that mimics the NP environment (G'=1kPa), cultured in hypoxic conditions (2% O2) and with specifically defined growth media. The cells were also tested in vivo in a large animal model. IVD degeneration was induced after an annular puncture in pigs, 4 weeks later the cells were injected and IVDs were analyzed at 12 weeks after the injury using MRI, gene expression analysis and histology. Results: After short-term exposure of iPSCs to GSK3i there was a significant change in cell morphology, Primitive Streak Mesoderm (PSM) markers (Brachyury, MIXL1, FOXF1) were upregulated and markers of pluripotency (Nanog, Oct4, Sox2) were downregulated, both compared to the control group. PSM cells nucleofected with Br (PSM-Br) cultured in TF hydrogels retained the NC phenotype consistently for up to 8 weeks, as seen in the gene expression analysis. PSM-Br cells were co-cultured with bone marrow (BM)-derived mesenchymal stem cells (MSCs) which, with time, expressed the NC markers in higher levels, however the levels of expression in BM-MSCs alone did not change. Higher expression of NC and NP marker genes in human BM-MSCs was found to be induced by iNC-condition media (iNC-CM) than porcine NC-CM. The annular puncture induced IVD degeneration as early as 2 weeks after the procedure. The injected iNCs were detected in the degenerated discs after 8 weeks in vivo. The iNC-treated discs were found protected from degeneration. This was evident in histological analysis and changes in the pH levels, indicative of degeneration state of the discs, observed using qCEST MRI. Immunofluorescence stains show that their phenotype was consistent with the in vitro study, namely they still expressed the notochordal markers Keratin 18, Keratin 19, Noto and Brachyury. Conclusion: In the present study, we report a stepwise differentiation method to generate notochordal cells from human iPSCs. These cells not only demonstrate a sustainable notochordal cell phenotype in vitro and in vivo, but also show the functionality of notochordal cells and have protective effect in case of induced disc degeneration and prevent the change in the pH level of the injected IVDs. The mechanism of this effect could be suggested via the paracrine effect on resident cells, as it was shown in the in vitro studies with MSCs.

In Vivo Imaging of Exogenous Progenitor Cells in Tendon Regeneration via Superparamagnetic Iron Oxide Particles.

BACKGROUND: Although tendon injuries and repairs are common, treatment of these injuries has limitations. The application of mesenchymal progenitor cells (MPCs) is increasingly used to optimize the biological process of tendon repair healing. However, clinically relevant technologies that effectively assess the localization of exogenous MPCs in vivo are lacking. HYPOTHESIS: Exogenous MPCs labeled with superparamagnetic iron oxide (SPIO) particles would allow monitoring of the localization and retention of cells within the site of implantation via magnetic resonance imaging (MRI) without negatively affecting cell survival or differentiation. STUDY DESIGN: Descriptive laboratory study. METHODS: Genetically modified C3H10T1/2 MPCs engineered to express luciferase (Luc+) reporter gene were implanted into surgically created Achilles tendon defects of 10 athymic nude rats (Hsd:RH-Foxn1rnu). Of these animals, 5 animals received Luc+ C3H10T1/2 MPCs colabeled with SPIO nanoparticles (+SPIO). These 2 groups of animals then underwent optical imaging with quantification of bioluminescence and MRI at 7, 14, and 28 days after surgery. Statistical analysis was conducted by use of 2-way analysis of variance. At 28 days after surgery, animals were euthanized and the treated limbs underwent histologic analysis. RESULTS: Optical imaging demonstrated that the implanted cells not only survived but also proliferated in vivo, and these cells remained viable for at least 4 weeks after implantation. In addition, SPIO labeling did not appear to affect MPC survival or proliferation, as assessed by quantitative bioluminescence imaging (P > .05, n = 5). MRI demonstrated that SPIO labeling was an effective method to monitor cell localization, retention, and viability for at least 4 weeks after implantation. Histologic and immunofluorescence analyses of the repaired tendon defect sites demonstrated tenocyte-like labeled cells, suggesting that cell differentiation was not affected by labeling the cells with the SPIO nanoparticles. CONCLUSION: MRI of exogenous MPCs labeled with SPIO particles allows for effective in vivo assessments of cell localization and retention in the setting of tendon regeneration for at least 4 weeks after implantation. This SPIO labeling does not appear to impair cell survival, transgene expression, or differentiation. CLINICAL RELEVANCE: SPIO labeling of MPCs appears to be safe for in vivo assessments of MPCs in tendon regeneration therapies and may be used for future clinical investigations of musculoskeletal regenerative medicine.

Association Between Type of Educational System and Prevalence and Severity of Myopia Among Male Adolescents in Israel.

IMPORTANCE: A substantial portion of the public is diagnosed with myopia, which increases the risk of potential sight-threatening complications. The association between study style and the development of myopia is unclear. OBJECTIVE: To analyze the association between studying in different educational systems and the prevalence and severity of myopia among Jewish male adolescents in Israel. DESIGN, SETTING, AND PARTICIPANTS: A nationwide, population-based study was conducted of 22 823 male candidates for military service in Israel aged 17 to 18 years attending the military draft board in 2013 who underwent a medical examination and a visual acuity assessment. Statistical analysis was performed from January 1 to March 31, 2018. EXPOSURES: The participants studied in 1 of 3 Israeli educational systems: secular, Orthodox, or ultra-Orthodox. The ultra-Orthodox system and, to a lesser extent, the Orthodox system involve intensive reading starting in early childhood compared with the secular system. MAIN OUTCOMES AND MEASURES: The odds ratio (OR) for the association between educational system and the prevalence and severity of myopia. RESULTS: Among the 22 823 participants (mean [SD] age, 17.7 [0.6] years), there was a higher proportion of adolescents in the ultra-Orthodox educational system with myopia (1871 of 2276 [82.2%]) compared with adolescents in the Orthodox educational system (1604 of 3189 [50.3%]) and those in the secular educational system (5155 of 17 358 [29.7%]). Compared with adolescents in the secular educational system, those in the Orthodox educational system were more likely to have myopia (OR, 2.3; 95% CI, 2.1-2.5; P < .001), as were those in the ultra-Orthodox educational system (OR, 9.3; 95% CI, 8.2-10.7; P < .001), after adjustment for age, country of origin, socioeconomic status, years of education, and body mass index. The multivariable adjusted OR for high myopia (refractive error of at least -6.0 diopters) was 4.6 (95% CI, 3.8-5.5; P < .001) for adolescents in the Orthodox educational system and 38.5 (95% CI, 30.7-48.2; P < .001) for adolescents in the ultra-Orthodox educational system compared with adolescents in the secular educational system. CONCLUSIONS AND RELEVANCE: This study provides evidence of the independent association between educational systems and the prevalence and severity of myopia. Male adolescents in the ultra-Orthodox educational system have higher odds of having myopia and high myopia. These findings suggest that study styles that involve intensive reading and other near-work activities (those done at a short working distance) play a role in the development of myopia and warrant consideration of prevention strategies.

Nonviral ultrasound-mediated gene delivery in small and large animal models.

Ultrasound-mediated gene delivery (sonoporation) is a minimally invasive, nonviral and clinically translatable method of gene therapy. This method offers a favorable safety profile over that of viral vectors and is less invasive as compared with other physical gene delivery approaches (e.g., electroporation). We have previously used sonoporation to overexpress transgenes in different skeletal tissues in order to induce tissue regeneration. Here, we provide a protocol that could easily be adapted to address various other targets of tissue regeneration or additional applications, such as cancer and neurodegenerative diseases. This protocol describes how to prepare, conduct and optimize ultrasound-mediated gene delivery in both a murine and a porcine animal model. The protocol includes the preparation of a microbubble-DNA mix and in vivo sonoporation under ultrasound imaging. Ultrasound-mediated gene delivery can be accomplished within 10 min. After DNA delivery, animals can be followed to monitor gene expression, protein secretion and other transgene-specific outcomes, including tissue regeneration. This procedure can be accomplished by a competent graduate student or technician with prior experience in ultrasound imaging or in performing in vivo procedures.