Retrograde thrombectomy of acute common carotid artery occlusion with mobile thrombus: illustrative cases.

BACKGROUND: Acute embolic occlusion of the common carotid artery (CCA) alone is rare. However, once it occurs, recanalization is challenging due to the large volume of the clot, larger diameter of the CCA, and risk of procedure-related distal embolism into the intracranial arteries. OBSERVATIONS: The authors report two cases of acute embolic occlusion of CCA alone, caused by a cardiac embolus trapped at the proximal end of a preexisting atherosclerotic plaque at the cervical carotid bifurcation. In both cases, the CCA was successfully recanalized using retrograde thrombectomy in a hybrid operating room. In case 1, a 78-year-old male with acute right CCA occlusion underwent retrograde thrombectomy, where the cervical carotid bifurcation was exposed and incised, and the entire embolus was retrieved with forceps. Despite successful revascularization, massive bleeding from the CCA just after the retrieval remained a concern. In case 2, a 79-year-old female with acute right CCA occlusion underwent retrograde thrombectomy in the same manner. Because manual retrieval failed, a Fogarty balloon catheter inserted from the arteriotomy successfully retrieved the entire thrombus with minimal blood loss. LESSONS: Retrograde thrombectomy through the arteriotomy of the cervical carotid bifurcation safely and effectively recanalizes acute embolic occlusion of the CCA alone.

Disruption of fetal eye development caused by insulin-induced maternal hypoglycemia in rats.

We previously revealed that insulin-induced severe and long-lasting maternal hypoglycemia in rats caused anophthalmia and microphthalmia in fetuses; however, it remained unclear whether hypoglycemia-induced eye anomalies were developmental retardation or disruption, and when and how they developed. Hence, we induced hypoglycemia in pregnant Sprague-Dawley rats by injecting insulin from Days 6 to 11 of pregnancy and performed periodical histopathological examination of fetal eyes from embryonic days (E)10 to 20. On E10, optic vesicle had developed normally both in the control and insulin-treated group; however, on E11, optic cup (OC) had developed in the control group but not in the insulin-treated group. On E12, neural retina (NR), retinal pigmented epithelium (RPE), lens, and presumptive cornea had been observed in the control group. In contrast, lens pit and OC with remaining space between RPE and NR had developed in the insulin-treated group. From E13 to E15, developmental disruption characterized by defects, hypoplasia, and degeneration in the retina, lens, and cornea was observed in the insulin-treated group, resulting in anophthalmia or microphthalmia on E20. Moreover, the expression of MITF and chx10, which are essential for early eye development by expressing in the presumptive retina and lens and regulating each other's expression level, was ectopic and suppressed on E11. In conclusion, insulin-induced maternal hypoglycemia caused developmental disruption, but not simple developmental retardation of fetal eyes, and its trigger might be a failure of presumptive retina and lens to interact on E11.

Effects of glucokinase activator, DS-7309, on embryo-fetal developmental toxicity in rats and rabbits.

The toxicological effects of DS-7309, a glucokinase activator, on pregnancy and embryo-fetal development in rats and rabbits and maternal blood glucose levels were examined. DS-7309 was administered at 3, 10, or 100 mg/kg to rats from Days 7-17 of pregnancy or at 10, 30, or 100 mg/kg to rabbits from Days 6-18 of pregnancy. In rats, maternal hypoglycemia (approximately 50 mg/dL) was seen at 3 and 10 mg/kg, but it recovered 7 h after dosing, leading to no toxic changes. In contrast, continuous severe maternal hypoglycemia (approximately 40 mg/dL, ≥7 h), fetal eye anomalies, and decreased fetal body weight were noted at 100 mg/kg. In rabbits, no fetal anomalies were seen at 10 and 30 mg/kg where maternal blood glucose level dropped to approximately 60-90 mg/dL, but recovered by 7 h after dosing at the latest. In contrast, at 100 mg/kg, severe hypoglycemia (around 60 mg/dL) was maintained and did not recover until 24 h after dosing; it resulted in decreased fetal viability and increased fetal skeleton anomalies. These findings indicate that DS-7309 could lead to embryo-fetal toxicity in rats and rabbits, with such toxicity considered to be related to continuous severe maternal hypoglycemia.

CO2-dependent migration and relocation of LCIB, a pyrenoid-peripheral protein in Chlamydomonas reinhardtii.

Most microalgae overcome the difficulty of acquiring inorganic carbon (Ci) in aquatic environments by inducing a CO2-concentrating mechanism (CCM). In the green alga Chlamydomonas reinhardtii, two distinct photosynthetic acclimation states have been described under CO2-limiting conditions (low-CO2 [LC] and very low-CO2 [VLC]). LC-inducible protein B (LCIB), structurally characterized as carbonic anhydrase, localizes in the chloroplast stroma under CO2-supplied and LC conditions. In VLC conditions, it migrates to aggregate around the pyrenoid, where the CO2-fixing enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase is enriched. Although the physiological importance of LCIB localization changes in the chloroplast has been shown, factors necessary for the localization changes remain uncertain. Here, we examined the effect of pH, light availability, photosynthetic electron flow, and protein synthesis on the localization changes, along with measuring Ci concentrations. LCIB dispersed or localized in the basal region of the chloroplast stroma at 8.3-15 µM CO2, whereas LCIB migrated toward the pyrenoid at 6.5 µM CO2. Furthermore, LCIB relocated toward the pyrenoid at 2.6-3.4 µM CO2, even in cells in the dark or treated with 3-(3,4-dichlorophenyl)-1,1-dimethylurea and cycloheximide in light. In contrast, in the mutant lacking CCM1, a master regulator of CCM, LCIB remained dispersed even at 4.3 µM CO2. Meanwhile, a simultaneous expression of LCIC, an interacting protein of LCIB, induced the localization of several speckled structures at the pyrenoid periphery. These results suggest that the localization changes of LCIB require LCIC and are controlled by CO2 concentration with ∼7 µM as the boundary.

Three-dimensional Visualization of Aortic Arch Morphology via Rearrangement of Non-enhanced Thoracic CT Images.

Objective: The objective of this study was to evaluate the reproducibility of three-dimensional (3D) images of the aortic arch reconstructed using a novel image processing algorithm for non-enhanced computed tomography (CT) images of the cervicothorax and abdomen obtained before emergency endovascular surgery. Case Presentations: In all, 46 patients who underwent acute mechanical thrombectomy between January and December 2018 were examined. The anatomical variations of the aortic arch were reproduced in all cases; however, the reproduction of the carotid arteries was difficult. Conclusion: Our novel 3D analysis system enables obtaining information on the aortic arch easily from plain CT data that may be useful in acute endovascular treatment.

Acute Proximal Anterior Circulation Occlusion after Pulmonary Lobectomy Treated by Endovascular Therapy: Two Case Reports.

Objective: We report two cases of acute proximal anterior circulation occlusion after pulmonary lobectomy. Case Presentation: Case 1 was a 64-year-old male who presented with occlusion of the right middle cerebral artery (MCA) one day after left lower lobectomy. Case 2 was a 68-year-old male who presented with occlusion of the right internal carotid artery (ICA). In both cases, mechanical thrombectomy was performed for complete recanalization and symptoms were improved. Conclusion: Prompt mechanical thrombectomy in the acute phase after pulmonary lobectomy improved the prognosis of patients with acute proximal anterior circulation occlusion. It is important to share information about ischemic complications with medical staff engaged in thoracic surgery.

Optimizing in-hospital triage for large vessel occlusion using a novel clinical scale (GAI2AA).

OBJECTIVE: To identify a proximal anterior circulation occlusion for effectively administering immediate mechanical thrombectomy by developing a novel, simple diagnostic scale to predict the occlusion, to compare its validity with available scales, and to assess its utility. METHODS: To develop a novel clinical scale, we retrospectively analyzed a cohort of 429 patients with acute ischemic stroke from a single center. The novel scale GAI2AA was applied to a prospective cohort of 259 patients from 3 stroke centers for external validation. The utility of the scale as an in-hospital triage was compared for the temporal factors of 158 patients with the occlusion. RESULTS: In a scale-developmental phase, those with a proximal anterior circulation occlusion had significantly more frequent signs of hemispheric symptoms, including gaze palsy, aphasia, inattention, arm paresis, and atrial fibrillation. The GAI2AA scale was developed using consolidated hemispheric symptoms and was scored as follows: score = 2, arm paresis score = 1, and atrial fibrillation score = 1. A cutoff value ≥3 was optimal for the correlation between sensitivity (88%) and specificity (81%), with a C statistic of 0.90 (95% confidence interval 0.87-0.93). External validation indicated that discrimination was significantly better than or not different from that of available complex scales. Door-to-puncture time was significantly reduced (91 [82-111] vs 52 [32-75] minutes, p < 0.001). CONCLUSION: The GAI2AA scale showed high sensitivity and specificity when an optimal cutoff score was used and was useful as an in-hospital triage tool.

Historical control data on developmental toxicity studies in rats.

Historical control data from prenatal developmental toxicity studies in rats have been used to evaluate whether toxicology outcomes were induced by exposure to a chemical or were within the range of spontaneous variation. These data are also important for monitoring animal characteristics. As a follow-up to historical control data from 1998 to 2010, this study analyzed control data from prenatal developmental studies performed in rats from 2011 to 2015. Data were collected from studies performed by 24 Japanese laboratories, including 15 pharmaceutical and chemical companies and nine contract research organizations, in Sprague-Dawley and two-sub-strains of Wistar Hannover rats. The data included maternal reproductive findings at terminal cesarean section and fetal findings, including incidences of spontaneous external, visceral, and skeletal anomalies. No noticeable differences in maternal reproductive data were observed among laboratories. The inter-laboratory variations in the incidences of fetal anomalies seemed to be due to differences in the selection of observation parameters, observation criteria, and classification of the findings, as well as to differences in terminology of fetal alterations. These historical control data may be helpful for adequate interpretation of experimental results and for evaluating the reproductive and developmental toxicities of various chemicals.

Safety and Efficacy of Intravenous Low-Dose Alteplase in Relative Contraindication Patients with Acute Ischemic Stroke.

OBJECT: The purpose of this study was to investigate the safety and efficacy of intravenous low-dose alteplase for acute ischemic stroke patients with relative contraindications. METHODS: The consecutive series of patients admitted within 4.5 hours of ischemic stroke onset between September 2012 and April 2017 were retrospectively evaluated. A good outcome at 90 days and symptomatic intracerebral hemorrhage were evaluated to determine the association with intravenous low-dose alteplase, especially in the presence of relative contraindications. RESULTS: Intravenous low-dose alteplase was administered to 219 of 315 patients (70%). A significantly higher number of patients treated with intravenous low-dose alteplase achieved a good outcome compared with those treated without alteplase (60% versus 44%; P = .014). The incidence of symptomatic intracerebral hemorrhage was not significantly different between the treatment groups. Multivariable logistic regression analysis of good outcome revealed that the significant independent factors were age of 81 years or older (odds ratio, .33; 95% confidence interval, .18-.60), National Institutes of Health Stroke Scale (NIHSS) of 4 or less (compared with NIHSS, 5-25; odds ratio, 3.3; 95% confidence interval, 1.8-6.4), modified Rankin scale score of 1 before stroke (odds ratio, .32; 95% confidence interval, .14-.73), and large changes on first brain imaging (odds ratio, .16; 95% confidence interval, .058-.44). Even with these relative contraindications, intravenous low-dose alteplase was still associated with good outcome (odds ratio, 3.1; 95% confidence interval, 1.6-5.8). CONCLUSIONS: Intravenous low-dose alteplase treatment can be safe and effective in relative contraindication patients with acute ischemic stroke.

Mechanical Thrombectomy in Anterior Circulation Occlusion Could Be More Effective than Medical Management Even in Low DWI-ASPECTS Patients.

The purpose of this study was to investigate whether patients with low preoperative Diffusion-weighted Imaging Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) could benefit from mechanical thrombectomy for acute anterior circulation occlusion. This was a retrospective, non-blinded, cohort study. From September 2012 to August 2016, 83 consecutive patients of acute anterior circulation occlusion were treated with thrombectomy using second-generation devices or medical management. The DWI-ASPECTS was scored after the first MRI. Patient characteristics and clinical outcomes were compared between the treatment groups. Significant dependence was defined as a modified Rankin scale score ≥3 at 90 days. As a result, 33 patients underwent mechanical thrombectomy and 50 received medical management. In the mechanical thrombectomy group, the variable of lower DWI-ASPECTS (5, 4-6 vs. 8, 7-8, P < 0.001), especially ≤6, was significantly associated with poor prognosis. However, compared with patients of DWI-ASPECTS ≤ 6 who received medical management, there were significantly fewer patients with poor outcomes in thrombectomy (dependent in 11 of 15 vs. 23 of 23, respectively; P = 0.019). Although patients with lower pretreatment DWI-ASPECTS could benefit less from thrombectomy, their outcomes were still better than medical management. Therefore, mechanical thrombectomy could be considered in some patients with low pretreatment DWI-ASPECTS.

Effects of maternal hypoglycemia on fetal eye and skeleton development in rats.

The relationship between insulin-induced maternal hypoglycemia and teratogenicity was investigated in detail. We injected 4 different forms of insulin (insulin human, aspart, glargine, and detemir) subcutaneously at 1 or 2 dose levels to Sprague-Dawley rats from Days 6 to 11 of pregnancy, measured blood glucose levels, and conducted fetal examination. In the insulin human and aspart (low dose) groups, while severe hypoglycemia (approximately 50mg/dL) was seen, it lasted only 6h and no fetal anomalies were observed. Fetal axial skeleton anomalies were observed in the aspart (high dose) group, which exhibited intermediate-duration of severe hypoglycemia (9h). Eye and axial skeleton anomalies were observed in the glargine and detemir groups, which exhibited continuous severe hypoglycemia (≥9h). These results revealed that insulin-induced maternal hypoglycemia caused fetal eye and skeleton anomalies and the causative key factors were duration of maternal severe hypoglycemia.

Dynamic simulations show repeated narrowing maximizes DNA linearization in elastomeric nanochannels.

This paper uses computer simulations to reveal unprecedented details about linearization of deoxyribonucleic acid (DNA) inside dynamic nanochannels that can be repeatedly widened and narrowed. We first analyze the effect of rate of channel narrowing on DNA linearization dynamics. Quick (∼0.1 s) narrowing of nanoscale channels results in rapid overstretching of the semi-flexible chain followed by a slower (∼0.1-10 s) relaxation to an equilibrium extension. Two phenomena that induce linearization during channel narrowing, namely, elongational-flow and confinement, occur simultaneously, regardless of narrowing speed. Interestingly, although elongational flow is a minimum at the mid-point of the channel and increases towards the two ends, neither the linearization dynamics nor the degree of DNA extension varies significantly with the center-of-mass of the polymer projected on the channel axis. We also noticed that there was a significant difference in time to reach the equilibrium length, as well as the degree of DNA linearization at short times, depending on the initial conformation of the biopolymer. Based on these observations, we tested a novel linearization protocol where the channels are narrowed and widened repeatedly, allowing DNA to explore multiple conformations. Repeated narrowing and widening, something uniquely enabled by the elastomeric nanochannels, significantly decrease the time to reach the equilibrium-level of stretch when performed within periods comparable to the chain relaxation time and more effectively untangle chains into more linearized biopolymers.

Media additives to promote spheroid circularity and compactness in hanging drop platform.

Three-dimensional spheroid cultures have become increasingly popular as drug screening platforms, especially with the advent of different high throughput spheroid forming technologies. However, comparing drug efficacy across different cell types in spheroid culture can be difficult due to variations in spheroid morphologies and transport characteristics. Improving the reproducibility of compact, circular spheroids contributes to standardizing and increasing the fidelity of the desired gradient profiles in these drug screening three-dimensional tissue cultures. In this study we discuss the role that circularity and compaction has on spheroids, and demonstrate the impact methylcellulose (MethoCel) and collagen additives in the culture media can contribute to more compact and circular spheroid morphology. We demonstrate that improved spheroid formation is not a simple function of increased viscosity of the different macromolecule additives, suggesting that other macromolecular characteristics contribute to improved spheroid formation. Of the various macromolecular additives tested for hanging drop culture, MethoCel provided the most desirable spheroid formation. Additionally, the higher viscosity of MethoCel-containing media improved the ease of imaging of cellular spheroids within hanging drop cultures by reducing motion-induced image blur.

Investigation of the teratogenic potential of VLA-4 antagonist derivatives in rats.

Very late antigen-4 (VLA-4), which is concerned with cell-cell adhesion, plays important roles in development of the heart, and some VLA-4 antagonists cause cardiac anomalies. In this study, we evaluated the teratogenic potential of VLA-4 antagonist derivatives as screening, and investigated the conditions that induce cardiac anomalies. Seventeen compounds were orally administered to pregnant rats throughout the organogenesis period, and fetal examinations were performed. In addition, drug concentrations in the embryos were assayed. As a result, the incidence of ventricular septal defect (VSD) ranged from 0 to 100% depending on the compound. Plasma drug concentrations in the dams were related to increased incidence of VSD; however, these incidences were not increased when the concentration of the compound in the embryos at 24h after dosing was low. It is considered that continuous pharmacological activity in the embryo for more than 24h might disrupt closure of the ventricular septum.

Fracture-based fabrication of normally closed, adjustable, and fully reversible microscale fluidic channels.

Adjustable fluidic structures play an important role in microfluidic systems. Fracture of multilayered materials under applied tension has been previously demonstrated as a convenient, simple, and inexpensive approach to fabricate nanoscale adjustable structures; here, it is demonstrated how to extend this concept to the microscale. This is achieved by a novel pairing of materials that leverages fracture mechanics to limit crack formation to a specified region, allowing to create size-controllable and adjustable microfluidic structures. This technique can be used to fabricate "normally closed" microfluidic channels that are completely reversible, a feature that is challenging to achieve in conventional systems without careful engineering controls. The adjustable microfluidic channels are then applied to mechanically lyse single cells, and subsequently manipulate the released nuclear chromatin, creating new possibilities for epigenetic analysis of single cells. This simple, versatile, and robust technology provides an easily accessible pathway to construct adjustable microfluidic structures, which will be useful in developing complex assays and experiments even in resource-limited settings.

Historical control data on developmental toxicity studies in rodents.

Historical control data on rodent developmental toxicity studies, performed between 1994 and 2010, were obtained from 19 laboratories in Japan, including 10 pharmaceutical and chemical companies and nine contract research organizations. Rats, mice, and hamsters were used for developmental toxicity studies. Data included maternal reproductive findings at terminal cesarean sections and fetal findings including the spontaneous incidences of external, visceral, and skeletal anomalies. No noticeable differences were observed in maternal reproductive data between laboratories. Inter-laboratory variations in the incidences of fetuses with anomalies appeared to be due to differences in the selection of observation parameters, observation criteria, classification of the findings, and terminology of fetal alterations. Historical control data are useful for the appropriate interpretation of experimental results and evaluation of the effects of chemical on reproductive and developmental toxicities.

External mechanical cues trigger the establishment of the anterior-posterior axis in early mouse embryos.

Mouse anterior-posterior axis polarization is preceded by formation of the distal visceral endoderm (DVE) by unknown mechanisms. Here, we show by in vitro culturing of embryos immediately after implantation in microfabricated cavities that the external mechanical cues exerted on the embryo are crucial for DVE formation, as well as the elongated egg cylinder shape, without affecting embryo-intrinsic transcriptional programs except those involving DVE-specific genes. This implies that these developmental events immediately after implantation are not simply embryo-autonomous processes but require extrinsic factors from maternal tissues. Moreover, the mechanical forces induce a breach of the basement membrane barrier at the distal portion locally, and thereby the transmigrated epiblast cells emerge as the DVE cells. Thus, we propose that external mechanical forces exerted by the interaction between embryo and maternal uterine tissues directly control the location of DVE formation at the distal tip and consequently establish the mammalian primary body axis.

Guided fracture of films on soft substrates to create micro/nano-feature arrays with controlled periodicity.

While the formation of cracks is often stochastic and considered undesirable, controlled fracture would enable rapid and low cost manufacture of micro/nanostructures. Here, we report a propagation-controlled technique to guide fracture of thin films supported on soft substrates to create crack arrays with highly controlled periodicity. Precision crack patterns are obtained by the use of strategically positioned stress-focusing V-notch features under conditions of slow application of strain to a degree where the notch features and intrinsic crack spacing match. This simple but robust approach provides a variety of precisely spaced crack arrays on both flat and curved surfaces. The general principles are applicable to a wide variety of multi-layered materials systems because the method does not require the careful control of defects associated with initiation-controlled approaches. There are also no intrinsic limitations on the area over which such patterning can be performed opening the way for large area micro/nano-manufacturing.

Micro- and nanofluidic technologies for epigenetic profiling.

This short review provides an overview of the impact micro- and nanotechnologies can make in studying epigenetic structures. The importance of mapping histone modifications on chromatin prompts us to highlight the complexities and challenges associated with histone mapping, as compared to DNA sequencing. First, the histone code comprised over 30 variations, compared to 4 nucleotides for DNA. Second, whereas DNA can be amplified using polymerase chain reaction, chromatin cannot be amplified, creating challenges in obtaining sufficient material for analysis. Third, while every person has only a single genome, there exist multiple epigenomes in cells of different types and origins. Finally, we summarize existing technologies for performing these types of analyses. Although there are still relatively few examples of micro- and nanofluidic technologies for chromatin analysis, the unique advantages of using such technologies to address inherent challenges in epigenetic studies, such as limited sample material, complex readouts, and the need for high-content screens, make this an area of significant growth and opportunity.

Induction of functional mesenchymal stem cells from rabbit embryonic stem cells by exposure to severe hypoxic conditions.

Embryonic stem cells (ESCs) have the potential to be used as an unlimited cell source for cell transplantation therapy, as well as for studying mechanisms of disease and early mammalian development. However, applications involving ESCs have been limited by the lack of reliable differentiation methods in many cases. Mesenchymal stem cells (MSCs) have also emerged as a promising cell source, but as suggested in recent studies, these cells display limited potential for proliferation and differentiation, thereby limiting their usefulness in the clinic and in the laboratory. Unfortunately, effective methods for induction of MSCs from pluripotent stem cells have not been established, and the development of such methods remains a major challenge facing stem cell biologists. Oxygen concentration is one of the most important factors regulating tissue development. It has profound effects on cell metabolism and physiology and can strongly influence stem cell fate. Here we demonstrate that severelow O(2) concentrations (1%) can function as a selective pressure for removing undifferentiated pluripotent cells during the induction of MSCs from rabbit ESCs (rESCs) and that MSCs induced under severe hypoxic conditions function as normal MSCs; that is, they repopulate after cloning, express specific markers (vimentin, CD29, CD90, CD105, and CD140a) and differentiate into adipocytes, osteoblasts, and chondrocytes. Furthermore, we demonstrate that these cells can contribute to cartilage regeneration in an in vivo rabbit model for joint cartilage injury. These results support the notion that exposing ESCs to severe hypoxic conditions during differentiation can be used as a strategy for the preparation of functional MSCs from ESCs.