Perivascular neurons instruct 3D vascular lattice formation via neurovascular contact

The vasculature of the central nervous system is a 3D lattice composed of laminar vascular beds interconnected by penetrating vessels. The mechanisms controlling 3D lattice network formation remain largely unknown. Combining viral labeling, genetic marking, and single-cell profiling in the mouse retina, we discovered a perivascular neuronal subset, annotated as Fam19a4/Nts-positive retinal ganglion cells (Fam19a4/Nts-RGCs), directly contacting the vasculature with perisomatic endfeet. Developmental ablation of Fam19a4/Nts-RGCs led to disoriented growth of penetrating vessels near the ganglion cell layer (GCL), leading to a disorganized 3D vascular lattice. We identified enriched PIEZO2 expression in Fam19a4/Nts-RGCs. Piezo2 loss from all retinal neurons or Fam19a4/Nts-RGCs abolished the direct neurovascular contacts and phenocopied the Fam19a4/Nts-RGC ablation deficits. The defective vascular structure led to reduced capillary perfusion and sensitized the retina to ischemic insults. Furthermore, we uncovered a Piezo2-dependent perivascular granule cell subset for cerebellar vascular patterning, indicating neuronal Piezo2-dependent 3D vascular patterning in the brain.

Plant size, latitude, and phylogeny explain within-population variability in herbivory

Interactions between plants and herbivores are central in most ecosystems, but their strength is highly variable. The amount of variability within a system is thought to influence most aspects of plant-herbivore biology, from ecological stability to plant defense evolution. Our understanding of what influences variability, however, is limited by sparse data. We collected standardized surveys of herbivory for 503 plant species at 790 sites across 116° of latitude. With these data, we show that within-population variability in herbivory increases with latitude, decreases with plant size, and is phylogenetically structured. Differences in the magnitude of variability are thus central to how plant-herbivore biology varies across macroscale gradients. We argue that increased focus on interaction variability will advance understanding of patterns of life on Earth.

Comparison of Three Handheld Fundus Cameras for Assessment of the Vertical Cup-To-Disk Ratio

Purpose To compare the quality of optic nerve photographs from three different handheld fundus cameras and to assess the reproducibility and agreement of vertical cup-to-disk ratio (VCDR) measurements from each camera. Methods Adult patients from a comprehensive ophthalmology clinic and an intravitreous injection clinic in northern Thailand were recruited for this cross-sectional study. Each participant had optic nerve photography performed with each of 3 handheld cameras: the Volk iNview, Volk Pictor Plus, and Peek Retina. Images were graded for VCDR in a masked fashion by two photo-graders and images with > 0.2 discrepancy in VCDR were assessed by a third photo-grader. Results A total of 355 eyes underwent imaging with three different handheld fundus cameras. Optic nerve images were judged ungradable in 130 (37%) eyes imaged with Peek Retina, compared to 36 (10%) and 55 (15%) eyes imaged with the iNview and Pictor Plus, respectively. For 193 eyes with gradable images from all 3 cameras, inter-rater reliability for VCDR measurements was poor or moderate for each of the cameras, with intraclass correlation coefficients ranging from 0.41 to 0.52. A VCDR ≥ 0.6 was found in 6 eyes on iNview images, 9 eyes on Pictor Plus images, and 3 eyes on Peek images, with poor agreement between cameras (e.g., no eyes graded as VCDR ≥ 0.6 on images from both the iNview and Pictor Plus). Conclusions Inter-rater reliability of VCDR grades from 3 handheld cameras was poor. Cameras did not agree on which eyes had large VCDRs.

Longitudinal Use of Telehealth During the COVID-19 Pandemic and Utility of Asynchronous Testing for Subspecialty-Level Ophthalmic Care

Importance

Telehealth in ophthalmology has traditionally focused on preventive disease screening with limited use in outpatient evaluation. The unique conditions of the COVID-19 pandemic afforded the opportunity to evaluate different implementations of teleophthalmology at scale, providing insight into expanding teleophthalmology care.

Objective

To compare telehealth use in ophthalmology with other specialties and assess the feasibility of augmenting ophthalmic telehealth encounters with asynchronous testing during the COVID-19 pandemic.

Design, Setting, and Participants

This quality improvement study evaluated retrospective, longitudinal, observational data from the first 18 months of the COVID-19 pandemic (January 1, 2020, through July 31, 2021) for 881 080 patients receiving care from outpatient primary care, cardiology, neurology, gastroenterology, surgery, neurosurgery, urology, orthopedic surgery, otolaryngology, obstetrics/gynecology, and ophthalmology clinics of the University of California, San Francisco. Asynchronous testing was evaluated for teleophthalmology encounters.

Interventions

A hybrid care model wherein ophthalmic testing data were acquired asynchronously and used to augment telehealth encounters.

Main Outcomes and Measures

Telehealth as a percentage of total volume of ambulatory care and use of asynchronous testing for ophthalmic conditions.

Results

The volume of in-person outpatient visits dropped by 83.3% (39 488 of 47 390) across the evaluated specialties at the onset of shelter-in-place orders for the COVID-19 pandemic, and the initial use of telehealth increased for these specialties before stabilizing over the 18-month study period. In ophthalmology, telehealth use peaked at 488 of 1575 encounters (31.0%) early in the pandemic and returned to mostly in-person visits as COVID-19 restrictions lifted. Elective use of telehealth was highest in gastroenterology, urology, neurology, and neurosurgery and lowest in ophthalmology. Asynchronous testing was combined with 126 teleophthalmology encounters, resulting in change of clinical management for 32 patients (25.4%) and no change for 91 (72.2%).

Conclusions and Relevance

Telehealth increased across various specialties during the COVID-19 pandemic. Combining teleophthalmic visits with asynchronous testing suggested that this approach is feasible for subspecialty-level evaluation. Additional study is needed to evaluate whether asynchronous testing outside the same institution could provide an effective and lasting approach for expanding the reach of ophthalmic telehealth.

Diagnostic accuracy of handheld fundus photography: A comparative study of three commercially available cameras

The objective of this study was to compare the sensitivity and specificity of handheld fundus cameras in detecting diabetic retinopathy (DR), diabetic macular edema (DME), and macular degeneration. Participants in the study, conducted at Maharaj Nakorn Hospital in Northern Thailand between September 2018 and May 2019, underwent an ophthalmologist examination as well as mydriatic fundus photography with three handheld fundus cameras (iNview, Peek Retina, Pictor Plus). Photographs were graded and adjudicated by masked ophthalmologists. Outcome measures included the sensitivity and specificity of each fundus camera for detecting DR, DME, and macular degeneration, relative to ophthalmologist examination. Fundus photographs of 355 eyes from 185 participants were captured with each of the three retinal cameras. Of the 355 eyes, 102 had DR, 71 had DME, and 89 had macular degeneration on ophthalmologist examination. The Pictor Plus was the most sensitive camera for each of the diseases (73-77%) and also achieved relatively high specificity (77-91%). The Peek Retina was the most specific (96-99%), although in part due to its low sensitivity (6-18%). The iNview had slightly lower estimates of sensitivity (55-72%) and specificity (86-90%) compared to the Pictor Plus. These findings demonstrated that the handheld cameras achieved high specificity but variable sensitivities in detecting DR, DME, and macular degeneration. The Pictor Plus, iNview, and Peek Retina would have distinct advantages and disadvantages when applied for utilization in tele-ophthalmology retinal screening programs.

Remote corneal suturing wet lab: microsurgical education during the COVID-19 pandemic

PURPOSE

To study the feasibility and efficacy of a new remote wet lab for microsurgical education using a corneal suturing task.

SETTING

Department of Ophthalmology, University of California San Francisco, San Francisco, California, USA.

DESIGN

Prospective randomized controlled study.

METHODS

Ten ophthalmology residents were stratified by postgraduate year and randomized to perform a corneal suturing task consisting of placing the 4 cardinal sutures for a penetrating keratoplasty in porcine eyes with or without remote ophthalmology attending feedback. Subsequently, both groups repeated the same task without remote feedback to test whether initial remote feedback affected subsequent performance. Finally, the group without feedback was crossed over to repeat the same corneal suturing task with remote feedback. The effectiveness of the remote wet lab was assessed subjectively by survey and objectively by grading each suture pass.

RESULTS

Resident-reported comfort with corneal suturing improved significantly after the remote wet lab for all residents. Residents and attendings rated the remote wet lab as equally or more effective compared with previous in-person wet labs and overall effective in corneal suturing. Attendings rated the remote wet lab as effective in multiple domains of microsurgical education using a modified microsurgical global rating scale. Objective corneal suturing performance was similar for both groups.

CONCLUSIONS

The remote wet lab was feasible and effective for training ophthalmology residents in corneal suturing. This represents a new social distancing compliant platform for microsurgical education during the COVID-19 pandemic.

The Role of Telemedicine to Alleviate an Increasingly Burdened Healthcare System: Retinopathy of Prematurity

Telemedicine-based remote digital fundus imaging (RDFI-TM) offers a promising platform for the screening of retinopathy of prematurity. RDFI-TM addresses some of the challenges faced by ophthalmologists in examining this vulnerable population in both low- and high-income countries. In this review, we studied the evidence on the use of RDFI-TM and analyzed the practical framework for RDFI-TM systems. We assessed the novel technological advances that can be deployed within RDFI-TM systems including noncontact imaging systems, smartphone-based imaging tools, and deep learning algorithms.

Reducing Native Ant Abundance Decreases Predation Rates in Midwestern Grasslands

Diverse and robust predator communities are important for effective prey suppression in natural and managed communities. Ants are ubiquitous components of terrestrial systems but their contributions to natural prey suppression is relatively understudied in temperate regions. Growing evidence suggests that ants can play a significant role in the removal of insect prey within grasslands, but their impact is difficult to separate from that of nonant predators. To test how ants may contribute to prey suppression in grasslands, we used poison baits (with physical exclosures) to selectively reduce the ant population in common garden settings, then tracked ant and nonant ground predator abundance and diversity, and removal of sentinel egg prey for 7 wk. We found that poison baits reduced ant abundance without a significant negative impact on abundance of nonant ground predators, and that a reduction in ant abundance decreased the proportion of sentinel prey eggs removed. Even a modest decrease (~20%) in abundance of several ant species, including the numerically dominant Lasius neoniger Emery (Hymenoptera: Formicidae), significantly reduced sentinel prey removal rates. Our results suggest that ants disproportionately contribute to ground-based predation of arthropod prey in grasslands. Changes in the amount of grasslands on the landscape and its management may have important implications for ant prevalence and natural prey suppression services in agricultural landscapes.

Usability testing of a smartphone-based retinal camera among first-time users in the primary care setting

Smartphone-based retinal photography is a promising method for increasing accessibility of retinal screening in the primary care and community settings. Recent work has focused on validating its use in detection of diabetic retinopathy. However, retinal imaging can be technically challenging and additional work is needed to improve ease of retinal imaging in the primary care setting. We therefore performed usability testing of a smartphone-based retinal camera, RetinaScope, among medical assistants in primary care who had never performed retinal imaging. A total of 24 medical assistants performed first-time imaging in a total of five rounds of testing, and iterative improvements to the device were made between test rounds based on the results. The time to acquire a single ~50 degree image of the posterior pole of a model eye decreased from 283 ± 60 seconds to 34 ± 17 seconds (p < 0.01) for first-time users. The time to acquire 5 overlapping images of the retina decreased from 325 ± 60 seconds to 118 ± 26 seconds (p = 0.02) for first-time users. Testing in the human eye demonstrated that a single wide-view retinal image could be captured in 65 ± 7 seconds and 5 overlapping images in 229 ± 114 seconds. Users reported high Systems Usability Scores of 86 ± 13 throughout the rounds, reflecting a high level of comfort in first-time operation of the device. Our study demonstrates that smartphone-based retinal photography has the potential to be quickly adopted among medical assistants in the primary care setting.

Smartphone-Based, Rapid, Wide-Field Fundus Photography for Diagnosis of Pediatric Retinal Diseases

Purpose

An important, unmet clinical need is for cost-effective, reliable, easy-to-use, and portable retinal photography to evaluate preventable causes of vision loss in children. This study presents the feasibility of a novel smartphone-based retinal imaging device tailored to imaging the pediatric fundus.

Methods

Several modifications for children were made to our previous device, including a child-friendly 3D printed housing of animals, attention-grabbing targets, enhanced image stitching, and video-recording capabilities. Retinal photographs were obtained in children undergoing routine dilated eye examination. Experienced masked retina-specialist graders determined photograph quality and made diagnoses based on the images, which were compared to the treating clinician's diagnosis.

Results

Dilated fundus photographs were acquired in 43 patients with a mean age of 6.7 years. The diagnoses included retinoblastoma, Coats' disease, commotio retinae, and optic nerve hypoplasia, among others. Mean time to acquire five standard photographs totaling 90-degree field of vision was 2.3 ± 1.1 minutes. Patients rated their experience of image acquisition favorably, with a Likert score of 4.6 ± 0.8 out of 5. There was 96% agreement between image-based diagnosis and the treating clinician's diagnosis.

Conclusions

We report a handheld smartphone-based device with modifications tailored for wide-field fundus photography in pediatric patients that can rapidly acquire fundus photos while being well-tolerated.

Translational Relevance

Advances in handheld smartphone-based fundus photography devices decrease the technical barrier for image acquisition in children and may potentially increase access to ophthalmic care in communities with limited resources.

A Smartphone-Based Tool for Rapid, Portable, and Automated Wide-Field Retinal Imaging

Purpose

High-quality, wide-field retinal imaging is a valuable method for screening preventable, vision-threatening diseases of the retina. Smartphone-based retinal cameras hold promise for increasing access to retinal imaging, but variable image quality and restricted field of view can limit their utility. We developed and clinically tested a smartphone-based system that addresses these challenges with automation-assisted imaging.

Methods

The system was designed to improve smartphone retinal imaging by combining automated fixation guidance, photomontage, and multicolored illumination with optimized optics, user-tested ergonomics, and touch-screen interface. System performance was evaluated from images of ophthalmic patients taken by nonophthalmic personnel. Two masked ophthalmologists evaluated images for abnormalities and disease severity.

Results

The system automatically generated 100° retinal photomontages from five overlapping images in under 1 minute at full resolution (52.3 pixels per retinal degree) fully on-phone, revealing numerous retinal abnormalities. Feasibility of the system for diabetic retinopathy (DR) screening using the retinal photomontages was performed in 71 diabetics by masked graders. DR grade matched perfectly with dilated clinical examination in 55.1% of eyes and within 1 severity level for 85.2% of eyes. For referral-warranted DR, average sensitivity was 93.3% and specificity 56.8%.

Conclusions

Automation-assisted imaging produced high-quality, wide-field retinal images that demonstrate the potential of smartphone-based retinal cameras to be used for retinal disease screening.

Translational Relevance

Enhancement of smartphone-based retinal imaging through automation and software intelligence holds great promise for increasing the accessibility of retinal screening.

Glaucoma Screening in Nepal: Cup-to-Disc Estimate With Standard Mydriatic Fundus Camera Compared to Portable Nonmydriatic Camera

PURPOSE

To compare cup-to-disc ratio (CDR) measurements from images taken with a portable, 45-degree nonmydriatic fundus camera to images from a traditional tabletop mydriatic fundus camera.

DESIGN

Prospective, cross-sectional, comparative instrument validation study.

METHODS

Setting: Clinic-based.

STUDY POPULATION

A total of 422 eyes of 211 subjects were recruited from the Tilganga Institute of Ophthalmology (Kathmandu, Nepal). Two masked readers measured CDR and noted possible evidence of glaucoma (CDR ≥ 0.7 or the presence of a notch or disc hemorrhage) from fundus photographs taken with a nonmydriatic portable camera and a mydriatic standard camera. Each image was graded twice.

MAIN OUTCOME MEASURES

Effect of camera modality on CDR measurement; inter- and intraobserver agreement for each camera for the diagnosis of glaucoma.

RESULTS

A total of 196 eyes (46.5%) were diagnosed with glaucoma by chart review; 41.2%-59.0% of eyes were remotely diagnosed with glaucoma over grader, repeat measurement, and camera modality. There was no significant difference in CDR measurement between cameras after adjusting for grader and measurement order (estimate = 0.004, 95% confidence interval [CI], 0.003-0.011, P = .24). There was moderate interobserver reliability for the diagnosis of glaucoma (Pictor: κ = 0.54, CI, 0.46-0.61; Topcon: κ = 0.63, CI, 0.55-0.70) and moderate intraobserver agreement upon repeat grading (Pictor: κ = 0.63 and 0.64, for graders 1 and 2, respectively; Topcon: κ = 0.72 and 0.80, for graders 1 and 2, respectively).

CONCLUSIONS

A portable, nonmydriatic, fundus camera can facilitate remote evaluation of disc images on par with standard mydriatic fundus photography.

The effect of PPARγ agonist on SGLT2 and glucagon expressions in alpha cells under hyperglycemia

BACKGROUND

Although sodium glucose cotransporter 2 (SGLT2) inhibitors have many beneficial effects for type 2 diabetes, including decreased cardiovascular death, recent reports that they increased glucagon through SGLT2 inhibition raised some concern. Troglitazone, Peroxisome proliferator-activated receptor γ (PPAR-γ) agonist, was reported to increase SGLT2 in renal proximal tubule cells, but its role on pancreatic alpha cells have not been reported. We investigated the effect of troglitazone on SGLT2 expression in alpha cells and subsequent glucagon regulation in hyperglycemia.

METHODS

An Alpha TC1-6 cell line was cultured in control (5 mM) or hyperglycemia (HG, 15 mM) for 72 h. We applied troglitazone with or without PPARγ antagonist (GW9662 10 μM). To investigate the involvement of PI3K/Akt pathway, we applied troglitazone with or without Wortmanin. We measured sodium glucose transporter 2 (SGLT2) and glucagon (GCG) mRNA and protein expression. PPAR gamma, PI3K and Akt protein were also measured.

RESULTS

Exposure of alpha TC cells to HG for 72 h increased glucagon mRNA and protein expression. HG decreased SGLT2 mRNA and protein expression. Troglitazone significantly reversed HG-induced reduction of SGLT2 expression and increase of glucagon secretion. PPARγ antagonist (GW9662 10 μM) decreased the expression of SGLT2 and increased glucagon as HG did. Hyperglycemia increased PI3K and pAkt expression in alpha cells. Wortmanin (PI3K inhibitor, 1 μM) reversed HG-induced SGLT2 decrease and glucagon increase. Troglitazone treatment decreased PI3K and pAkt expression in HG.

CONCLUSION

In conclusion, PPARγ agonist, troglitazone improved glucose transport SGLT2 dysfunction and subsequent glucagon dysregulation in alpha cell under hyperglycemia. Those effects were through the involvement of PI3K/pAkt signaling pathway. This study may add one more reason for the ideal combination of PPARγ agonist and SGLT2 inhibitor in clinical practice.

Associations of Low Muscle Mass and the Metabolic Syndrome in Caucasian and Asian Middle-aged and Older Adults

OBJECTIVE

Age-related declines in skeletal muscle mass may confer significant metabolic consequences for older adults. Associations of low muscle mass and metabolic syndrome (MetS) in Caucasians, and comparisons with associations observed in Asian populations, have not been reported. We examined associations of low muscle mass and metabolic syndrome (MetS) in Asian and Caucasian middle-aged and older men and women using criteria for low muscle mass.

DESIGN, SETTING AND PARTICIPANTS

Two population-based studies of Australian (Tasmanian Older Adult Cohort Study; TASOAC; N=1005) and Korean (Korean Sarcopenic Obesity Study; KSOS; N=376) community-dwelling adults, mean age 62 and 58 years, respectively.

MEASUREMENTS

Appendicular lean mass (aLM) determined by dual-energy X-ray absorptiometry and normalised to height squared (aLM/Ht2), weight (aLM/Wt) or body mass index (aLM/BMI). Participants in the lowest sex-specific 20% for aLM measures were defined as having low muscle mass. MetS was defined according to National Cholesterol Education Program Adult Treatment Panel III criteria.

RESULTS

Although Australians demonstrated generally unfavourable anthropometric and metabolic characteristics compared to Koreans, prevalence of MetS was similar (29.5% in Australians and 31.4% in Koreans, respectively). Low aLM/Ht2 was associated with significantly reduced likelihood of MetS in both Australians (OR: 0.30, 95% CI 0.19 - 0.46) and Koreans (OR: 0.31, 95% CI 0.16 - 0.62). Conversely, low aLM/BMI was associated with increased odds for MetS in Australians (OR: 1.78, 95% CI 1.12 - 2.84), but not Koreans (OR: 1.33, 95% CI = 0.67 - 2.64).

CONCLUSION

Low aLM/BMI is associated with significantly increased likelihood of MetS in Australian adults, but not Koreans, suggesting potential differences in effects of low muscle mass relative to body mass on cardiometabolic health in Caucasian and Asian middle-aged and older adults. Low muscle mass relative to height is associated with reduced likelihood of MetS in both populations.

Molecular identification of venous progenitors in the dorsal aorta reveals an aortic origin for the cardinal vein in mammals

Coordinated arterial-venous differentiation is crucial for vascular development and function. The origin of the cardinal vein (CV) in mammals is unknown, while conflicting theories have been reported in chick and zebrafish. Here, we provide the first molecular characterization of endothelial cells (ECs) expressing venous molecular markers, or venous-fated ECs, within the emergent dorsal aorta (DA). These ECs, expressing the venous molecular markers Coup-TFII and EphB4, cohabited the early DA with ECs expressing the arterial molecular markers ephrin B2, Notch and connexin 40. These mixed ECs in the early DA expressed either the arterial or venous molecular marker, but rarely both. Subsequently, the DA exhibited uniform arterial markers. Real-time imaging of mouse embryos revealed EC movement from the DA to the CV during the stage when venous-fated ECs occupied the DA. We analyzed mutants for EphB4, which encodes a receptor tyrosine kinase for the ephrin B2 ligand, as we hypothesized that ephrin B2/EphB4 signaling may mediate the repulsion of venous-fated ECs from the DA to the CV. Using an EC quantification approach, we discovered that venous-fated ECs increased in the DA and decreased in the CV in the mutants, whereas the rest of the ECs in each vessel were unaffected. This result suggests that the venous-fated ECs were retained in the DA and missing in the CV in the EphB4 mutant, and thus that ephrin B2/EphB4 signaling normally functions to clear venous-fated ECs from the DA to the CV by cell repulsion. Therefore, our cellular and molecular evidence suggests that the DA harbors venous progenitors that move to participate in CV formation, and that ephrin B2/EphB4 signaling regulates this aortic contribution to the mammalian CV.

Percentage of the population at high risk of osteoporotic fracture in South Korea: analysis of the 2010 Fifth Korean National Health and Nutrition Examination survey data

Osteoporosis and high-risk osteopenia (high-risk of osteoporotic fractures) are highly prevalent in South Korean postmenopausal women and men aged 50 years and over.

INTRODUCTION

This study determined the percentages of the population at high risk of osteoporotic fractures according to the World Health Organization (WHO) criteria and the Fracture Risk Assessment (FRAX) model.

METHODS

Data collected from the 2010 Fifth Korean National Health and Nutrition Examination Survey, a cross-sectional survey of the general South Korean general population, were analyzed. The percentages of the population with high-risk osteopenia according to the US National Osteoporosis Foundation (NOF) and Japanese treatment guidelines were subsequently determined and compared.

RESULTS

Based on the WHO criteria and FRAX model, 37.7% of the menopausal women and 12.7% of the men aged 50 years and older are at high risk of osteoporotic fracture. According to the Japanese and NOF guidelines, 10.9 (10.6% of men and 11.2% of women) and 10.7% (10.6% of men and 10.9% of women), respectively, of the study population with osteopenia are at high risk of fracture. By age group, 49.3% of Korean women aged 55 years and older, 67.7% of Korean women aged 65 years and older, and 33.5% of Korean men aged 75 years and older are at high risk.

CONCLUSION

As a very large percentage of the South Korean postmenopausal population has osteoporosis or high-risk osteopenia, greater effort at identifying and treating this population should be expended to prevent osteoporotic fracture.

Abstract 187: Constitutively Active Notch4 Elicits Brain Arteriovenous Malformations through Capillary Enlargement

Brain arteriovenous (AV) malformation (BAVM) is characterized by focal lesions of enlarged, tangled vessels that shunt blood from arteries to veins. BAVMs can rupture and cause life-threatening stroke. The origin of BAVM is currently unknown. We have developed a transgenic mouse model of BAVM via endothelial expression of constitutively-active Notch4 (Notch4*). Here, using two-photon excited fluorescence microscopy through chronically-implanted cranial windows, we obtained 4D data on the formation of BAVMs in live animals. We found that BAVMs arose from enlargement of pre-existing capillaries - judged as vessels with capillary diameter and blood flow as well as the absence of smooth muscle coverage. Capillary enlargement began promptly following the start of Notch4* expression and often occurred before increases in blood flow. Supporting the capillary origin of BAVMs, alterations in Notch signaling in endothelial cells of capillaries and veins, but not arteries, affected BAVM formation. Although the initiation of capillary enlargement was widespread, more proximal, lower resistance, AV connections grew into AVMs at the expense of more distal AV connections, by increasing in diameter and blood flow velocity through a positive feedback effect. Our data uncovers a mechanism underlying the focal BAVM formation elicited by a perturbation in gene expression throughout the endothelium.

Active cathepsins B, L, and S in murine and human pancreatitis

Cathepsins regulate premature trypsinogen activation within acinar cells, a key initial step in pancreatitis. The identity, origin, and causative roles of activated cathepsins in pancreatic inflammation and pain are not defined. By using a near infrared-labeled activity-based probe (GB123) that covalently modifies active cathepsins, we localized and identified activated cathepsins in mice with cerulein-induced pancreatitis and in pancreatic juice from patients with chronic pancreatitis. We used inhibitors of activated cathepsins to define their causative role in pancreatic inflammation and pain. After GB123 administration to mice with pancreatitis, reflectance and confocal imaging showed significant accumulation of the probe in inflamed pancreas compared with controls, particularly in acinar cells and macrophages, and in spinal cord microglia and neurons. Biochemical analysis of pancreatic extracts identified them as cathepsins B, L, and S (Cat-B, Cat-L, and Cat-S, respectively). These active cathepsins were also identified in pancreatic juice from patients with chronic pancreatitis undergoing an endoscopic procedure for the treatment of pain, indicating cathepsin secretion. The cathepsin inhibitor K11777 suppressed cerulein-induced activation of Cat-B, Cat-L, and Cat-S in the pancreas and ameliorated pancreatic inflammation, nocifensive behavior, and activation of spinal nociceptive neurons. Thus pancreatitis is associated with an increase in the active forms of the proteases Cat-B, Cat-L, and Cat-S in pancreatic acinar cells and macrophages, and in spinal neurons and microglial cells. Inhibition of cathepsin activation ameliorated pancreatic inflammation and pain. Activity-based probes permit identification of proteases that are predictive biomarkers of disease progression and response to therapy and may be useful noninvasive tools for the detection of pancreatic inflammation.

A decision tree-based approach for identifying urban-rural differences in metabolic syndrome risk factors in the adult Korean population

AIM

The purpose of this study was to explore the difference in the pattern of metabolic syndrome (MetS) in urban and rural populations in Korea using data mining techniques.

SUBJECTS AND METHODS

In total, 1013 adults >30 yr of age from urban (184 males and 313 females) and rural districts (211 males and 305 females) were recruited from Gyeongsangnam-do, Korea. Modified National Cholesterol Education Program Adult Treatment Panel III criteria were used to identify individuals with MetS. We applied a decision tree analysis to elucidate the differences in the clustering of MetS components between the urban and rural populations.

RESULTS

The prevalence of MetS was 33.2% and 35.2% in urban and rural districts, respectively (p=0.598). The decision-tree approach revealed that the combination of high serum triglycerides (TG) + high systolic blood pressure (SBP), high TG + low HDL cholesterol, and high waist circumference (WC) + high SBP + high fasting plasma glucose (FPG) were strong predictors of MetS in the urban population, whereas the combination of TG + SBP + WC and SBP + WC + FPG showed high positive predictive value for the presence of MetS in the rural population.

CONCLUSIONS

Although no significant difference was found for the prevalence of MetS between the two populations, the differences in the clustering pattern of MetS components in urban and rural districts in Korea were identified by decision tree analysis. Our findings may serve as a basis to design necessary population-based intervention programs for prevention and progression of MetS and its complications in Korea.

X-space MPI: magnetic nanoparticles for safe medical imaging

One quarter of all iodinated contrast X-ray clinical imaging studies are now performed on Chronic Kidney Disease (CKD) patients. Unfortunately, the iodine contrast agent used in X-ray is often toxic to CKD patients' weak kidneys, leading to significant morbidity and mortality. Hence, we are pioneering a new medical imaging method, called Magnetic Particle Imaging (MPI), to replace X-ray and CT iodinated angiography, especially for CKD patients. MPI uses magnetic nanoparticle contrast agents that are much safer than iodine for CKD patients. MPI already offers superb contrast and extraordinary sensitivity. The iron oxide nanoparticle tracers required for MPI are also used in MRI, and some are already approved for human use, but the contrast agents are far more effective at illuminating blood vessels when used in the MPI modality. We have recently developed a systems theoretic framework for MPI called x-space MPI, which has already dramatically improved the speed and robustness of MPI image reconstruction. X-space MPI has allowed us to optimize the hardware for fi ve MPI scanners. Moreover, x-space MPI provides a powerful framework for optimizing the size and magnetic properties of the iron oxide nanoparticle tracers used in MPI. Currently MPI nanoparticles have diameters in the 10-20 nanometer range, enabling millimeter-scale resolution in small animals. X-space MPI theory predicts that larger nanoparticles could enable up to 250 micrometer resolution imaging, which would represent a major breakthrough in safe imaging for CKD patients.

Line-scanning particle image velocimetry: an optical approach for quantifying a wide range of blood flow speeds in live animals

BACKGROUND

The ability to measure blood velocities is critical for studying vascular development, physiology, and pathology. A key challenge is to quantify a wide range of blood velocities in vessels deep within living specimens with concurrent diffraction-limited resolution imaging of vascular cells. Two-photon laser scanning microscopy (TPLSM) has shown tremendous promise in analyzing blood velocities hundreds of micrometers deep in animals with cellular resolution. However, current analysis of TPLSM-based data is limited to the lower range of blood velocities and is not adequate to study faster velocities in many normal or disease conditions.

METHODOLOGY/PRINCIPAL FINDINGS

We developed line-scanning particle image velocimetry (LS-PIV), which used TPLSM data to quantify peak blood velocities up to 84 mm/s in live mice harboring brain arteriovenous malformation, a disease characterized by high flow. With this method, we were able to accurately detect the elevated blood velocities and exaggerated pulsatility along the abnormal vascular network in these animals. LS-PIV robustly analyzed noisy data from vessels as deep as 850 µm below the brain surface. In addition to analyzing in vivo data, we validated the accuracy of LS-PIV up to 800 mm/s using simulations with known velocity and noise parameters.

CONCLUSIONS/SIGNIFICANCE

To our knowledge, these blood velocity measurements are the fastest recorded with TPLSM. Partnered with transgenic mice carrying cell-specific fluorescent reporters, LS-PIV will also enable the direct in vivo correlation of cellular, biochemical, and hemodynamic parameters in high flow vascular development and diseases such as atherogenesis, arteriogenesis, and vascular anomalies.

Notch4 normalization reduces blood vessel size in arteriovenous malformations

Abnormally enlarged blood vessels underlie many life-threatening disorders including arteriovenous (AV) malformations (AVMs). The core defect in AVMs is high-flow AV shunts, which connect arteries directly to veins, "stealing" blood from capillaries. Here, we studied mouse brain AV shunts caused by up-regulation of Notch signaling in endothelial cells (ECs) through transgenic expression of constitutively active Notch4 (Notch4*). Using four-dimensional two-photon imaging through a cranial window, we found that normalizing Notch signaling by repressing Notch4* expression converted large-caliber, high-flow AV shunts to capillary-like vessels. The structural regression of the high-flow AV shunts returned blood to capillaries, thus reversing tissue hypoxia. This regression was initiated by vessel narrowing without the loss of ECs and required restoration of EphB4 receptor expression by venous ECs. Normalization of Notch signaling resulting in regression of high-flow AV shunts, and a return to normal blood flow suggests that targeting the Notch pathway may be useful therapeutically for treating diseases such as AVMs.

Synchronous ipsilateral Bochdalek and Morgagni diaphragmatic hernias: a case report

The etiology of congenital diaphragmatic hernia (CDH) is unknown. Phenotypic patterns of CDH defects provide clues about normal diaphragm development and the pathophysiology of CDH. We report a case of a patient who was diagnosed with CDH postnatally and was found on imaging to have simultaneous Bochdalek and Morgagni hernias on the right side. During the operative repair of these defects, an additional left-sided Morgagni-type defect was also found. To the best of our knowledge, this form of CDH has not been previously reported.

The association between the ratio of visceral fat to thigh muscle area and metabolic syndrome: the Korean Sarcopenic Obesity Study (KSOS)

OBJECTIVE

A relationship between visceral fat accumulation and metabolic syndrome (MetS) has been established. However, the effect of a relative increase in visceral fat and a decrease in muscle mass on metabolic disorders has not been investigated. The aim of the present study was to examine the association between the ratio of visceral fat to thigh muscle area (VMR) and MetS in Korean adults. STUDY SUBJECT/MEASUREMENTS: A total of 264 age-and gender-matched subjects recruited from the Korean Sarcopenic Obesity Study (KSOS), an ongoing prospective observational cohort study, were categorized into four groups based on their body mass index (BMI) and VMR. We measured visceral fat area and thigh muscle area using computed tomography.

RESULTS

Subjects with MetS showed a significantly higher VMR than those without MetS. In both obese and nonobese groups, the subjects with a higher VMR had a higher prevalence of MetS than those in the lower VMR groups. VMR was significantly related to components of the metabolic syndrome, especially in women, and was positively correlated with a number of MetS components in both men and women. In multiple logistic regression analysis, the odds ratio for MetS was 6·72 (highest vs lowest quartile, 95% confidence interval, 1·60-28·14) after an adjustment of potential confounders, including BMI and waist-to-hip ratio.

CONCLUSION

VMR is significantly increased in subjects with MetS and independently associated with MetS. These results suggest that the VMR may be a potential indicator for MetS risk in Korean adults.

Arterial-venous segregation by selective cell sprouting: an alternative mode of blood vessel formation

Blood vessels form de novo (vasculogenesis) or upon sprouting of capillaries from preexisting vessels (angiogenesis). With high-resolution imaging of zebrafish vascular development, we uncovered a third mode of blood vessel formation whereby the first embryonic artery and vein, two unconnected blood vessels, arise from a common precursor vessel. The first embryonic vein formed by selective sprouting of progenitor cells from the precursor vessel, followed by vessel segregation. These processes were regulated by the ligand EphrinB2 and its receptor EphB4, which are expressed in arterial-fated and venous-fated progenitors, respectively, and interact to orient the direction of progenitor migration. Thus, directional control of progenitor migration drives arterial-venous segregation and generation of separate parallel vessels from a single precursor vessel, a process essential for vascular development.

A Ubiquitous Chronic Disease Care system using cellular phones and the internet

AIMS

The rapidly increasing prevalence of chronic diseases is an important challenge to healthcare systems worldwide. To improve the quality and efficiency of chronic disease care, we investigated the effectiveness and applicability of the Ubiquitous Chronic Disease Care (UCDC) system using cellular phones and the internet for overweight patients with both Type 2 diabetes and hypertension.

METHODS

We conducted a randomized, controlled clinical trial over 3 months that included 123 patients at a university hospital and a community public health centre.

RESULTS

After 12 weeks, there were significant improvements in HbA(1c) in the intervention group (7.6 +/- 0.9% to 7.1 +/- 0.8%, P < 0.001) compared with the control group (7.4 +/- 0.9% to 7.6 +/- 1.0%, P = 0.03). Furthermore, we observed a significant reduction in systolic and diastolic blood pressure, as well as improvements in total cholesterol, low-density lipoprotein-cholesterol and triglyceride levels in the intervention group. Furthermore, there was a significant increase in adiponectin levels in the intervention group compared with the control group, although high-sensitivity C-reactive protein and interleukin-6 levels did not change in either group.

CONCLUSIONS

The novel UCDC system presented in this paper improved multiple metabolic parameters simultaneously in overweight patients with both Type 2 diabetes and hypertension.

Effect of exercise training on A-FABP, lipocalin-2 and RBP4 levels in obese women

OBJECTIVE

Lipocalin family proteins, including adipocyte fatty acid-binding protein (A-FABP), lipocalin-2 and retinol-binding protein 4 (RBP4), have recently been identified as novel adipokines associated with obesity, type 2 diabetes and the metabolic syndrome. We have evaluated the effect of exercise training on lipocalin family proteins and inflammatory markers.

STUDY SUBJECTS

Thirty obese Korean women and 15 age-matched nonobese control subjects were studied.

DESIGN

Concentrations of the lipocalin family proteins were compared between obese and nonobese women and were evaluated before and 3 months after an exercise programme consisting of aerobic exercise (45 min/session, 300 kcal/day) and muscle strength training (20 min/session, 100 kcal/day) five times a week.

RESULTS

Obese women exhibited higher A-FABP levels compared to nonobese women (21.4 +/- 6.4 microg/l vs. 13.6 +/- 4.4 microg/l, P < 0.001). However, neither lipocalin-2 nor RBP4 levels were significantly different between the two groups, although the difference in lipocalin-2 was marginally significant (P = 0.054). Circulating A-FABP levels were significantly associated with body mass index (BMI), waist circumference, triglyceride, alanine aminotransferase (ALT), lipocalin-2 and high-sensitivity C-reactive protein (hsCRP) levels. After 3 months of the exercise training programme, serum A-FABP levels decreased significantly from 21.4 +/- 6.4 microg/l to 19.3 +/- 6.8 microg/l (P = 0.038), along with a reduction in weight, BMI, waist circumference, fasting glucose and total cholesterol levels. There was no significant change in the lipocalin-2 and RBP4 levels, although IL-6 levels increased after the exercise programme.

CONCLUSION

Exercise training with weight loss induced a significant reduction in circulating A-FABP levels in obese Korean women.

Association of extracellular cleavage of E-cadherin mediated by MMP-7 with HGF-induced in vitro invasion in human stomach cancer cells

BACKGROUND

Proteolytic shedding of the ectodomain of a variety of transmembrane proteins, including cell-to-cell adhesion molecules, has been observed in solid cancers. We have investigated whether extracellular cleavage of E-cadherin mediated by matrix metalloproteinase-7 (MMP-7) is involved in hepatocyte growth factor (HGF) induced in vitro invasion in stomach cancer cells.

METHODS

The effects of HGF on the expression of E-cadherin/beta-catenin and MMP-7 at both the protein and mRNA levels were assessed in stomach cancer cells, NUGC-3 and MKN-28, and in cells in which the expression of MMP-7 was downregulated by transfection with a MMP-7 short hairpin RNA plasmid.

RESULTS

Treatment with HGF increased the extracellular cleavage of E-cadherin and the release of MMP-7 and reduced the level of E-cadherin in a dose- and time-dependent manner. HGF treatment repressed the phosphorylation of beta-catenin in a Triton-soluble fraction, but enhanced this phosphorylation in a Triton-insoluble fraction. The association of E-cadherin with beta-catenin was decreased by HGF treatment in the Triton-soluble fraction. In addition, treatment of MMP-7 short hairpin RNA transfected NUGC-3 cells with HGF resulted in no extracellular cleavage of E-cadherin and also decreased the in vitro cell invasion.

CONCLUSIONS

These results suggest that incubation with HGF mediated the release of MMP-7, resulting in extracellular cleavage of E-cadherin from stomach cancer cells. This might be a key mechanism in HGF-induced in vitro invasion and metastasis.

A mechanistic study of the antibacterial effect of silver ions on Escherichia coli and Staphylococcus aureus

To investigate the mechanism of inhibition of silver ions on microorganisms, two strains of bacteria, namely Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), were treated with AgNO(3) and studied using combined electron microscopy and X-ray microanalysis. Similar morphological changes occurred in both E. coli and S. aureus cells after Ag(+) treatment. The cytoplasm membrane detached from the cell wall. A remarkable electron-light region appeared in the center of the cells, which contained condensed deoxyribonucleic acid (DNA) molecules. There are many small electron-dense granules either surrounding the cell wall or depositing inside the cells. The existence of elements of silver and sulfur in the electron-dense granules and cytoplasm detected by X-ray microanalysis suggested the antibacterial mechanism of silver: DNA lost its replication ability and the protein became inactivated after Ag(+) treatment. The slighter morphological changes of S. aureus compared with E. coli recommended a defense system of S. aureus against the inhibitory effects of Ag(+) ions.

Antimicrobial effects of metal ions (Ag+, Cu2+, Zn2+) in hydroxyapatite

The antimicrobial ceramics (AC) based on hydroxyapatite (HA) were made in a wet chemical process with additions of AgNO3, Cu(NO3)2. 3H2O and Zn(NO3)2. 6H2O. The ACs were composed of metal-ion substituted hydroxyapatite and nitrate-apatite, which was identified by X-ray diffraction. The viable count and turbidity measurement was adopted to observe the antimicrobial effects of the various ACs. The aerobic Escherichia coli was used in the study. An obvious antimicrobial effect against E. coli was observed in Ag+ AC. In contrast to Ag+ AC, it was difficult to ascertain any bactericidal effect in the case of Cu2+ and Zn2+ AC. The bactericidal effect of Ag+ was observed using a dialysis tube experiment. This suggests that Ag+ dissolved out and reacted with E. coli, thus inhibiting its growth.

[Immunoenzyme analysis of post-vaccination secretory immunity to influenza A and B viruses using a manufactured monoclonal immunoenzyme test system]

The formation of postvaccinal secretory immunity to influenza A and B viruses was studied by a new monoclonal enzyme immunoassay test system for measuring specific secretory IgA in young people vaccinated with live cold-adapted vaccines (LCAV) intranasally and with inactivated commercial centrifuged influenza vaccine (IIV) parenterally, intranasally, and orally. Secretory IgA most intensively accumulated in subjects intranasally vaccinated with LCAV, less so in subjects vaccinated with IIV intranasally and orally, and just negligibly in those vaccinated with IIV parenterally. In vaccinees immunized with LCAV intranasally the intensity of immune secretory response depended on the initial concentrations of specific IgA before vaccination. Intranasal administration of LCAV in the presence of high concentrations of secretory IgA led in some subjects either to a decrease in the incidence of conversions or to a 2-8-fold drop of their initial titers. Parenteral injection of IIV caused the most expressed suppression of the immune response in the secretory immunity system. Use of biological stimulant adaptogen increased 2.2 times the incidence of conversions of secretory IgA in subjects intranasally vaccinated with LCAV.

A case of biliary cystadenocarcinoma

Biliary cystadenocarcinoma is a very rare cystic tumor that arises in the liver or, less frequently, in the extrahepatic biliary system. It has been shown to arise in congenital liver cysts, bile ducts, biliary cystadenoma, in the context of fibropolycystic disease and in the hepatoduodenal ligament. Common presenting symptoms include an abdominal mass, local pain, nausea, jaundice, fever or occasional ascites. Some patients are asymptomatic, the lesion being an incidental finding at autopsy or surgery. Approximately 50 cases have been reported in the literature. We report a case of biliary cystadenocarcinoma in a 63-year-old man with a review of the literature.

[The use of saliva for study in the immunoenzyme analysis of postvaccinal and postinfectious immunity to influenza]

Paired specimens of blood sera, upper respiratory tract secretions, and saliva from healthy, influenza-infected, and live influenza trivaccine-immunized humans were tested in parallel by HI tests and enzyme immunoassay (EIA). The resulting comparative data suggest that determination by EIA of specific secretory IgA in the saliva may be recommended as an independent test for large-scale influenza diagnosis, evaluation of the immune status of people, and trials of influenza vaccines. By immunologic parameters, this method is not inferior to the standard ones. At the same time its advantages include simplicity and readily available large volumes of saliva even from children as well as no necessity to bleed subjects to be examined.

[Antibody functional activity in immunization with influenza vaccines]

The functional activity of serum antibody had been shown previously to reflect the state of resistance to influenza more accurately than antibody concentration. The functional activity of antibodies in the vaccination process was studied. The immune response to influenza antigens was found to be accompanied by an increase in the functional activity of antibodies, the intensity of this increase was the highest in natural influenza infection, moderate after administration of live vaccines and the least after immunization with inactivated preparations. The vaccine strains may differ significantly in their capacity to stimulate antibody with high functional activity. The quantitative parameters of the functional activity of antibody are directly related to the antigen dose and frequency of antigenic stimulation.

A case of primary intestinal lymphangiectasia

A 26-year-old male patient who had an 8 years history of recurrent peripheral edema with diarrhea and hypoproteinemia was evaluated. Endoscopic jejunal and ileal biopsy revealed markedly dilated mucosal lymph vessels with no evidence of inflammation. 99mTc-labeled human serum albumin (HSA) scintigraphy showed significant activity accumulating in the gastrointestinal tract to represent 99mTc-HSA leakage into the bowel lumen. A diagnosis of protein losing enteropathy and intestinal lymphangiectasia could be made. After treatment with a high protein and fat restricted diet, his symptoms subsided and the serum protein level was normalized.

[Regularities of formation in a general population of serum antibodies to previously circulated influenza A viruses]

The spectrum of antibody production against hemagglutinin of all known influenza A virus serotypes after influenza A (H3N2) infection in persons of all age groups (from 1 month to 72 years) was analysed to investigated the regularities of accumulation of antibodies against influenza A viruses gone out of circulation. For the same purpose, a long-term (many years) longitudinal analysis of serum anti-HA antibody levels against "old" influenza A (HSW1N1), A (H0N1), A (H1N1), A (H2N2), and A (H3N2) viruses was carried out in children and adults of various age groups in 6 cities of different geographical regions of the country. Based on the results of the study, the concept of the "original antigenic sin" is analysed critically, and a new original concept on the regularities of antibody genesis against previously prevalent influenza A viruses and the factors affecting this process has been formulated.

[Indicators of collective immunity to influenza depending on the blood group and sex of the population]

Immunological investigations of the time course of serum anti-HA and anti-NA antibodies against influenza A and B viruses in the female and male population with blood groups 0(I), A(II), B(III), and AB(IV) were carried out for several months. The persons with the blood group AB (IV) were shown to be most sensitive to influenza A and B. They were affected by the epidemic virus earlier and more severely than those with the other blood groups. A special method is proposed for prediction of the etiology of the forthcoming epidemic. A correlation between blood groups and titres of anti-HA but not anti-NA antibodies was observed. The view on the lack of the genetic factor influence on the affliction with influenza and antibody response in persons of different sexes is substantiated.

[Characteristics of the immunologic response to Mycoplasma pneumoniae as a polyclonal lymphocyte activator]

M. pneumoniae, used as mitogen, was shown to initiate the synthesis of antibodies to salmonellae in the culture of lymphocytes obtained from healthy donors as actively as lectins and Staphylococcus aureus protein A. In these experiments IgG antibodies were mainly synthesized. The serological study of a group of persons (333 subjects) for 2.5 years revealed that seroconversion to M. pneumoniae and simultaneously to viruses occurred in 78% of cases. In more than a half of the cases a rise in the titers of antibodies to M. pneumoniae and simultaneously to salmonellae was found to occur with no cases of salmonellosis being registered. The results of this study make it possible to come to the conclusion that M. pneumoniae is a polyclonal activator of antibody-producing cells in vitro and, probably, in vivo.