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Fulltext PDLLA-Zn-nitrided Fe bioresorbable scaffold with 53-μm-thick metallic struts and tunable multistage biodegradation function

Shen D, Qi H, Lin W, Zhang W, Bian D, Shi X, et al.

Sci Adv, 2021 Jun;7(23).
PMID: 34088662 DOI: 10.1126/sciadv.abf0614

Balancing the biodegradability and mechanical integrity of a bioresorbable scaffold (BRS) with time after implantation to match the remodeling of the scaffolded blood vessel is important, but a key challenge in doing so remains. This study presents a novel intercalated structure of a metallic BRS by introducing a nanoscale Zn sacrificial layer between the nitrided Fe platform and the sirolimus-carrying poly(d,l-lactide) drug coating. The PDLLA-Zn-FeN BRS shows a multistage biodegradation behavior, maintaining mechanical integrity at the initial stage and exhibiting accelerated biodegradation at the subsequent stage in both rabbit abdominal aortas and human coronary arteries, where complete biodegradation was observed about 2 years after implantation. The presence of the nanoscale Zn sacrificial layer with an adjustable thickness also contributes to the tunable biodegradation of BRS and allows the reduction of the metallic strut thickness to 53 μm, with radial strength as strong as that of the current permanent drug-eluting stents.
Fulltext Clinical practice with steroid therapy for Duchenne muscular dystrophy: An expert survey in Asia and Oceania

Takeuchi F, Nakamura H, Yonemoto N, Komaki H, Rosales RL, Kornberg AJ, et al.

Brain Dev, 2020 Mar;42(3):277-288.
PMID: 31980267 DOI: 10.1016/j.braindev.2019.12.005

BACKGROUND: Several studies on clinical practice for Duchenne muscular dystrophy (DMD) have been conducted in Western countries. However, there have been only a few similar studies in Asia and Oceania. Here, we investigate the steroid therapy-related clinical practice for DMD among the local experts. In 2015, we conducted a DMD expert survey in Asia and Oceania to acquire information regarding patients with DMD and to assess current clinical practice with the cooperation of Asian and Oceanian Myology Centre, a neuromuscular disease research network.
RESULTS: We obtained survey responses from 87 out of 148 clinicians (62%) from 13 countries and regions. In China, 1385 DMD patients were followed-up by 5 respondent neurologists, and 84% were between 0 and 9 years of age (15% were 10-19 years, 1% > 19 years). While in Japan, 1032 patients were followed-up by 20 clinicians, and the age distribution was similar between the 3 groups (27% were 0-9 years, 35% were 10-19 years, 38% were >19 years). Most respondent clinicians (91%) were aware of DMD standard of care recommendations. Daily prednisolone/prednisone administration was used most frequently at initiation (N = 45, 64%). Inconsistent opinion on steroid therapy after loss of ambulation and medication for bone protection was observed.
CONCLUSIONS: Rare disease research infrastructures have been underdeveloped in many of Asian and Oceanian countries. In this situation, our results show the snapshots of current medical situation and clinical practice in DMD. For further epidemiological studies, expansion of DMD registries is necessary.
Fulltext Genetic diversity and transmission patterns of Burkholderia pseudomallei on Hainan island, China, revealed by a population genomics analysis

Zheng H, Qin J, Chen H, Hu H, Zhang X, Yang C, et al.

Microb Genom, 2021 11;7(11).
PMID: 34762026 DOI: 10.1099/mgen.0.000659

Burkholderia pseudomallei is a Gram-negative soil-dwelling bacillus that causes melioidosis, a frequently fatal infectious disease, in tropical and subtropical regions. Previous studies have identified the overall genetic and evolutionary characteristics of B. pseudomallei on a global scale, including its origin and transmission routes. However, beyond its known hyperendemicity foci in northern Australia and Southeast Asia, the distribution and genetic characteristics of B. pseudomallei in most tropical regions remain poorly understood, including in southern China. Here, we sequenced the genomes of 122 B. pseudomallei strains collected from Hainan, an island in southern China, in 2002-2018, to investigate the population structure, relationships with global strains, local epidemiology, and virulence and antimicrobial-resistance factors. A phylogenetic analysis and hierarchical clustering divided the Hainan strains into nine phylogenic groups (PGs), 80 % of which were concentrated within five major groups (group 1: corresponding to minor sequence types [STs], 12.3 %; group 3: ST46 and ST50, 31.1 %; group 9: ST58, 13.1 %; group 11: ST55, 8.2 %; group 15: mainly ST658, 15.6%). A phylogenetic analysis that included global strains suggested that B. pseudomallei in Hainan originated from Southeast Asian countries, transmitted in multiple historical importation events. We also identified several mutual transmission events between Hainan and Southeast Asian countries in recent years, including three importation events from Thailand and Singapore to Hainan and three exportation events from Hainan to Singapore, Malaysia, and Taiwan island. A statistical analysis of the temporal distribution showed that the Hainan strains of groups 3, 9, and 15 have dominated the disease epidemic locally in the last 5 years. The spatial distribution of the Hainan strains demonstrated that some PGs are distributed in different cities on Hainan island, and by combining phylogenic and geographic distribution information, we detected 21 between-city transmission events, indicating its frequent local transmission. The detection of virulence factor genes showed that 56 % of the Hainan strains in group 1 encode a B. pseudomallei-specific adherence factor, boaB, confirming the specific pathogenic characteristics of the Hainan strains in group 1. An analysis of the antimicrobial-resistance potential of B. pseudomallei showed that various kinds of alterations were identified in clinically relevant antibiotic resistance factors, such as AmrR, PenA and PBP3, etc. Our results clarify the population structure, local epidemiology, and pathogenic characteristics of B. pseudomallei in Hainan, providing further insight into its regional and global transmission networks and improving our knowledge of its global phylogeography.
Robot-assisted Cavectomy Versus Thrombectomy for Level II Inferior Vena Cava Thrombus: Decision-making Scheme and Multi-institutional Analysis

Shi T, Huang Q, Liu K, Du S, Fan Y, Yang L, et al.

Eur Urol, 2020 10;78(4):592-602.
PMID: 32305170 DOI: 10.1016/j.eururo.2020.03.020

BACKGROUND: Robot-assisted thrombectomy (RAT) for inferior vena cava (IVC) thrombus (RAT-IVCT) is being increasingly reported. However, the techniques and indications for robot-assisted cavectomy (RAC) for IVC thrombus are not well described.
OBJECTIVE: To develop a decision-making program and analyze multi-institutional outcomes of RAC-IVCT versus RAT-IVCT.
DESIGN, SETTING, AND PARTICIPANTS: Ninety patients with renal cell carcinoma (RCC) with level II IVCT were included from eight Chinese urological centers, and underwent RAC-IVCT (30 patients) or RAT-IVCT (60 patients) from June 2013 to January 2019.
SURGICAL PROCEDURE: The surgical strategy was based on IVCT imaging characteristics. RAT-IVCT was performed with standardized cavotomy, thrombectomy, and IVC reconstruction. RAC-IVCT was mainly performed in patients with extensive IVC wall invasion when the collateral blood vessels were well-established. For right-sided RCC, the IVC from the infrarenal vein to the infrahepatic veins was stapled. For left-sided RCC, the IVC from the suprarenal vein to the infrahepatic veins was removed and caudal IVC reconstruction was performed to ensure the right renal vein returned through the IVC collaterals.
MEASUREMENTS: Clinicopathological, operative, and survival outcomes were collected and analyzed.
RESULTS AND LIMITATIONS: All procedures were successfully performed without open conversion. The median operation time (268 vs 190 min) and estimated blood loss (1500 vs 400 ml) were significantly greater for RAC-IVCT versus RAT-IVCT (both p < 0.001). IVC invasion was a risk factor for progression-free and overall survival at midterm follow-up. Large-volume and long-term follow-up studies are needed.
CONCLUSIONS: RAC-IVCT or RAT-IVCT represents an alternative minimally invasive approach for selected RCC patients with level II IVCT. Selection of RAC-IVCT or RAT-IVCT is mainly based on preoperative IVCT imaging characteristics, including the presence of IVC wall invasion, the affected kidney, and establishment of the collateral circulation.
PATIENT SUMMARY: In this study we found that robotic surgeries for level II inferior vena cava thrombus were feasible and safe. Preoperative imaging played an important role in establishing an appropriate surgical plan.
Fulltext Comparative genomics of the nonlegume Parasponia reveals insights into evolution of nitrogen-fixing rhizobium symbioses

van Velzen R, Holmer R, Bu F, Rutten L, van Zeijl A, Liu W, et al.

Proc Natl Acad Sci U S A, 2018 May 15;115(20):E4700-E4709.
PMID: 29717040 DOI: 10.1073/pnas.1721395115

Nodules harboring nitrogen-fixing rhizobia are a well-known trait of legumes, but nodules also occur in other plant lineages, with rhizobia or the actinomycete Frankia as microsymbiont. It is generally assumed that nodulation evolved independently multiple times. However, molecular-genetic support for this hypothesis is lacking, as the genetic changes underlying nodule evolution remain elusive. We conducted genetic and comparative genomics studies by using Parasponia species (Cannabaceae), the only nonlegumes that can establish nitrogen-fixing nodules with rhizobium. Intergeneric crosses between Parasponia andersonii and its nonnodulating relative Trema tomentosa demonstrated that nodule organogenesis, but not intracellular infection, is a dominant genetic trait. Comparative transcriptomics of P. andersonii and the legume Medicago truncatula revealed utilization of at least 290 orthologous symbiosis genes in nodules. Among these are key genes that, in legumes, are essential for nodulation, including NODULE INCEPTION (NIN) and RHIZOBIUM-DIRECTED POLAR GROWTH (RPG). Comparative analysis of genomes from three Parasponia species and related nonnodulating plant species show evidence of parallel loss in nonnodulating species of putative orthologs of NIN, RPG, and NOD FACTOR PERCEPTION Parallel loss of these symbiosis genes indicates that these nonnodulating lineages lost the potential to nodulate. Taken together, our results challenge the view that nodulation evolved in parallel and raises the possibility that nodulation originated ∼100 Mya in a common ancestor of all nodulating plant species, but was subsequently lost in many descendant lineages. This will have profound implications for translational approaches aimed at engineering nitrogen-fixing nodules in crop plants.
IDRiD: Diabetic Retinopathy - Segmentation and Grading Challenge

Porwal P, Pachade S, Kokare M, Deshmukh G, Son J, Bae W, et al.

Med Image Anal, 2020 01;59:101561.
PMID: 31671320 DOI: 10.1016/j.media.2019.101561

Diabetic Retinopathy (DR) is the most common cause of avoidable vision loss, predominantly affecting the working-age population across the globe. Screening for DR, coupled with timely consultation and treatment, is a globally trusted policy to avoid vision loss. However, implementation of DR screening programs is challenging due to the scarcity of medical professionals able to screen a growing global diabetic population at risk for DR. Computer-aided disease diagnosis in retinal image analysis could provide a sustainable approach for such large-scale screening effort. The recent scientific advances in computing capacity and machine learning approaches provide an avenue for biomedical scientists to reach this goal. Aiming to advance the state-of-the-art in automatic DR diagnosis, a grand challenge on "Diabetic Retinopathy - Segmentation and Grading" was organized in conjunction with the IEEE International Symposium on Biomedical Imaging (ISBI - 2018). In this paper, we report the set-up and results of this challenge that is primarily based on Indian Diabetic Retinopathy Image Dataset (IDRiD). There were three principal sub-challenges: lesion segmentation, disease severity grading, and localization of retinal landmarks and segmentation. These multiple tasks in this challenge allow to test the generalizability of algorithms, and this is what makes it different from existing ones. It received a positive response from the scientific community with 148 submissions from 495 registrations effectively entered in this challenge. This paper outlines the challenge, its organization, the dataset used, evaluation methods and results of top-performing participating solutions. The top-performing approaches utilized a blend of clinical information, data augmentation, and an ensemble of models. These findings have the potential to enable new developments in retinal image analysis and image-based DR screening in particular.