Aggregated chromosomes/chromatin transfer: a novel approach for mitochondrial replacement with minimal mitochondrial carryover: the implications of mouse experiments for human aggregated chromosome transfer.

Nuclear transfer techniques, including spindle chromosome complex (SC) transfer and pronuclear transfer, have been employed to mitigate mitochondrial diseases. Nevertheless, the challenge of mitochondrial DNA (mtDNA) carryover remains unresolved. Previously, we introduced a method for aggregated chromosome (AC) transfer in human subjects, offering a potential solution. However, the subsequent rates of embryonic development have remained unexplored owing to legal limitations in Japan, and animal studies have been hindered by a lack of AC formation in other species. Building upon our success in generating ACs within mouse oocytes via utilization of the phosphodiesterase inhibitor 3-isobutyl 1-methylxanthine (IBMX), this study has established a mouse model for AC transfer. Subsequently, a comparative analysis of embryo development rates and mtDNA carryover between AC transfer and SC transfer was conducted. Additionally, the mitochondrial distribution around SC and AC structures was investigated, revealing that in oocytes at the metaphase II stage, the mitochondria exhibited a relatively concentrated arrangement around the spindle apparatus, while the distribution of mitochondria in AC-formed oocytes appeared to be independent of the AC position. The AC transfer approach produced a marked augmentation in rates of fertilization, embryo cleavage, and blastocyst formation, especially as compared to scenarios without AC transfer in IBMX-treated AC-formed oocytes. No significant disparities in fertilization and embryo development rates were observed between AC and SC transfers. However, relative real-time PCR analyses revealed that the mtDNA carryover for AC transfers was one-tenth and therefore significantly lower than that of SC transfers. This study successfully accomplished nuclear transfers with ACs in mouse oocytes, offering an insight into the potential of AC transfers as a solution to heteroplasmy-related challenges. These findings are promising in terms of future investigation with human oocytes, thus advancing AC transfer as an innovative approach in the field of human nuclear transfer methodology.

Teriparatide improves microarchitectural characteristics of peri-implant bone in orchiectomized rats.

This study evaluated the peri-implant bone repair in orchiectomized rats receiving intermittently PTH 1-34. The treatment returned the bone quality and quantity of the animals to normal in the computerized microtomography, laser confocal microscopy, and histological analysis. The PTH 1-34 promoted marked bone formation with increased volume, improved quality, and greater bone turnover. INTRODUCTION: Osteoporosis can be a problem in implant osseointegration. So this study aimed to evaluate the quantity and quality of peri-implant bone repair in orchiectomized Wistar rats receiving intermittently administered PTH 1-34. METHODS: Animals (n = 24) were divided into 3 groups: healthy control (SHAM), orchiectomized (ORQ), and orchiectomized and treated with 0.5 µg/kg/day PTH 1-34 (TERI), and each received an implant in the right and left tibial metaphysis, which was allowed to repair for 60 days. The resultant bone formation was evaluated through computerized microtomography (micro-CT) to compare the percent bone volume (BV/TV), trabecular thickness (Tb.Th), trabecular number and separation (Tb.N, Tb.Sp), and bone implant contact (BIC) through the intersection surface (i.S) between groups. Laser confocal microscopy was used to evaluate fluorochrome areas for mineral apposition rate (MAR) and neoformed bone area (NBA). In addition, histological evaluation of calcified tissues with Stevenel blue and alizarin red staining was performed. RESULTS: Treatment with PTH 1-34 returned the bone quality and quantity of the osteoporotic animal to normal, as the TERI group presented statistically significant higher values for BV/TV, Tb.Th, and BIC parameters compared with ORQ (p < 0.05), but when compared with SHAM (p > 0.05), no statistical difference was noted. In addition, in the bone turnover analysis (MAR, NBA) for TERI, the highest results are presented, followed by SHAM, and then ORQ (TERI × ORQ: p < 0.05). CONCLUSIONS: Intermittent treatment with PTH 1-34 on orchiectomized animals promoted marked bone formation with increased volume, improved quality, and greater bone turnover in the peri-implant space, returning the bone quality and quantity to the present standard in healthy animals.

Frequency-dependent shear properties of annulus fibrosus and nucleus pulposus by magnetic resonance elastography.

Aging and degeneration are associated with changes in mechanical properties in the intervertebral disc, generating interest in the establishment of mechanical properties as early biomarkers for the degenerative cascade. Magnetic resonance elastography (MRE) of the intervertebral disc is usually limited to the nucleus pulposus, as the annulus fibrosus is stiffer and less hydrated. The objective of this work was to adapt high-frequency needle MRE to the characterization of the shear modulus of both the nucleus pulposus and annulus fibrosus. Bovine intervertebral discs were removed from fresh oxtails and characterized by needle MRE. The needle was inserted in the center of the disc and vibrations were generated by an amplified piezoelectric actuator. MRE acquisitions were performed on a 4.7-T small-animal MR scanner using a spin echo sequence with sinusoidal motion encoding gradients. Acquisitions were repeated over a frequency range of 1000-1800 Hz. The local frequency estimation inversion algorithm was used to compute the shear modulus. Stiffness maps allowed the visualization of the soft nucleus pulposus surrounded by the stiffer annulus fibrosus surrounded by the homogeneous gel. A significant difference in shear modulus between the nucleus pulposus and annulus fibrosus, and an increase in the shear modulus with excitation frequency, were observed, in agreement with the literature. This study demonstrates that global characterization of both the nucleus pulposus and annulus fibrosus of the intervertebral disc is possible with needle MRE using a preclinical magnetic resonance imaging (MRI) scanner. MRE can be a powerful method for the mapping of the complex properties of the intervertebral disc. The developed method could be adapted for in situ use by preserving adjacent vertebrae and puncturing the side of the intervertebral disc, thereby allowing an assessment of the contribution of osmotic pressure to the mechanical behavior of the intervertebral disc.

Requirements for accurate estimation of anisotropic material parameters by magnetic resonance elastography: A computational study.

PURPOSE: To establish the essential requirements for characterization of a transversely isotropic material by magnetic resonance elastography (MRE). THEORY AND METHODS: Three methods for characterizing nearly incompressible, transversely isotropic (ITI) materials were used to analyze data from closed-form expressions for traveling waves, finite-element (FE) simulations of waves in homogeneous ITI material, and FE simulations of waves in heterogeneous material. Key properties are the complex shear modulus µ2 , shear anisotropy ϕ=µ1/µ2-1, and tensile anisotropy ζ=E1/E2-1. RESULTS: Each method provided good estimates of ITI parameters when both slow and fast shear waves with multiple propagation directions were present. No method gave accurate estimates when the displacement field contained only slow shear waves, only fast shear waves, or waves with only a single propagation direction. Methods based on directional filtering are robust to noise and include explicit checks of propagation and polarization. Curl-based methods led to more accurate estimates in low noise conditions. Parameter estimation in heterogeneous materials is challenging for all methods. CONCLUSIONS: Multiple shear waves, both slow and fast, with different propagation directions, must be present in the displacement field for accurate parameter estimates in ITI materials. Experimental design and data analysis can ensure that these requirements are met. Magn Reson Med 78:2360-2372, 2017. © 2017 International Society for Magnetic Resonance in Medicine.

A cortical folding model incorporating stress-dependent growth explains gyral wavelengths and stress patterns in the developing brain.

In humans and many other mammals, the cortex (the outer layer of the brain) folds during development. The mechanics of folding are not well understood; leading explanations are either incomplete or at odds with physical measurements. We propose a mathematical model in which (i) folding is driven by tangential expansion of the cortex and (ii) deeper layers grow in response to the resulting stress. In this model the wavelength of cortical folds depends predictably on the rate of cortical growth relative to the rate of stress-induced growth. We show analytically and in simulations that faster cortical expansion leads to shorter gyral wavelengths; slower cortical expansion leads to long wavelengths or even smooth (lissencephalic) surfaces. No inner or outer (skull) constraint is needed to produce folding, but initial shape and mechanical heterogeneity influence the final shape. The proposed model predicts patterns of stress in the tissue that are consistent with experimental observations.

Elastic characterization of transversely isotropic soft materials by dynamic shear and asymmetric indentation.

The mechanical characterization of soft anisotropic materials is a fundamental challenge because of difficulties in applying mechanical loads to soft matter and the need to combine information from multiple tests. A method to characterize the linear elastic properties of transversely isotropic soft materials is proposed, based on the combination of dynamic shear testing (DST) and asymmetric indentation. The procedure was demonstrated by characterizing a nearly incompressible transversely isotropic soft material. A soft gel with controlled anisotropy was obtained by polymerizing a mixture of fibrinogen and thrombin solutions in a high field magnet (B = 11.7 T); fibrils in the resulting gel were predominantly aligned parallel to the magnetic field. Aligned fibrin gels were subject to dynamic (20-40 Hz) shear deformation in two orthogonal directions. The shear storage modulus was 1.08 ± 0. 42 kPa (mean ± std. dev.) for shear in a plane parallel to the dominant fiber direction, and 0.58 ± 0.21 kPa for shear in the plane of isotropy. Gels were indented by a rectangular tip of a large aspect ratio, aligned either parallel or perpendicular to the normal to the plane of transverse isotropy. Aligned fibrin gels appeared stiffer when indented with the long axis of a rectangular tip perpendicular to the dominant fiber direction. Three-dimensional numerical simulations of asymmetric indentation were used to determine the relationship between direction-dependent differences in indentation stiffness and material parameters. This approach enables the estimation of a complete set of parameters for an incompressible, transversely isotropic, linear elastic material.

Propulsive forces on the flagellum during locomotion of Chlamydomonas reinhardtii.

The distributed propulsive forces exerted on the flagellum of the swimming alga Chlamydomonas reinhardtii by surrounding fluid were estimated from experimental image data. Images of uniflagellate mutant Chlamydomonas cells were obtained at 350 frames/s with 125-nm spatial resolution, and the motion of the cell body and the flagellum were analyzed in the context of low-Reynolds-number fluid mechanics. Wild-type uniflagellate cells, as well as uniflagellate cells lacking inner dynein arms (ida3) or outer dynein arms (oda2) were studied. Ida3 cells exhibit stunted flagellar waveforms, whereas oda2 cells beat with lower frequency. Image registration and sorting algorithms provided high-resolution estimates of the motion of the cell body, as well as detailed kinematics of the flagellum. The swimming cell was modeled as an ellipsoid in Stokes flow, propelled by viscous forces on the flagellum. The normal and tangential components of force on the flagellum (f(N) and f(T)) were related by resistive coefficients (C(N) and C(T)) to the corresponding components of velocity (V(N) and V(T)).The values of these coefficients were estimated by satisfying equilibrium requirements for force and torque on the cell. The estimated values of the resistive coefficients are consistent among all three genotypes and similar to theoretical predictions.

Multiple ulcers in the small and large intestines occurred during tocilizumab therapy for rheumatoid arthritis.

Tocilizumab is a monoclonal antibody against human interleukin-6 receptor which blocks the binding of interleukin-6 to its receptor. Tocilizumab is effective for the treatment of inflammatory disorders including rheumatoid arthritis. We report a case of multiple ulcers in the small and large intestines, which occurred during tocilizumab therapy. A 57-year-old woman started to use tocilizumab for rheumatoid arthritis. Three months later, she complained of hematochezia. Double-balloon endoscopy revealed multiple small aphthoid ulcers in the small and large intestines. One month after the woman had recovered, she was given tocilizumab again. The woman had hematochezia and abdominal pain again 2 weeks later. Colonoscopy revealed multiple round, discrete punched-out ulcers in the terminal ileum, and vast deep ulcers from the cecum to the descending colon. Bioptic histopathology and cultivation showed non-specific findings. Six weeks after discontinuation of tocilizumab, ulcers in the small and large intestine dramatically improved, leaving ulcer scars. This disease course and the results of examination made us strongly suspect that tocilizumab induced multiple ulcers in the small and large intestines. Interleukin-6 is a pleiotropic cytokine and involved in intestinal mucosal wound healing as well as in inflammatory processes. It is possible that tocilizumab inhibited tissue repair of the intestine and caused intestinal ulcers.

Natural oscillatory modes of 3D deformation of the human brain in vivo.

Natural modes and frequencies of three-dimensional (3D) deformation of the human brain were identified from in vivo tagged magnetic resonance images (MRI) acquired dynamically during transient mild acceleration of the head. Twenty 3D strain fields, estimated from tagged MRI image volumes in 19 adult subjects, were analyzed using dynamic mode decomposition (DMD). These strain fields represented dynamic, 3D brain deformations during constrained head accelerations, either involving rotation about the vertical axis of the neck or neck extension. DMD results reveal fundamental oscillatory modes of deformation at damped frequencies near 7 Hz (in neck rotation) and 11 Hz (in neck extension). Modes at these frequencies were found consistently among all subjects. These characteristic features of 3D human brain deformation are important for understanding the response of the brain in head impacts and provide valuable quantitative criteria for the evaluation and use of computer models of brain mechanics.

Endoscopic submucosal dissection of early colorectal tumors using a grasping-type scissors forceps: a preliminary clinical study.

To reduce the risk of complications related to endoscopic submucosal dissection (ESD), we developed a new grasping-type scissors forceps (GSF), which can grasp and incise the targeted tissue using an electrosurgical current. We prospectively evaluated the efficacy and safety of ESD using GSF for the removal of colorectal tumors in 10 consecutive patients. After the submucosa had been injected with a solution, the lesion was separated from the surrounding normal mucosa by complete incision around the lesion using the GSF. A piece of submucosal tissue was grasped and cut with the GSF using an electrosurgical current to achieve submucosal excision. All lesions were treated easily and safely with no unexpected incisions. No delayed hemorrhage or perforation occurred. En bloc resection was obtained in all cases. The tumor-free lateral/basal margins were obtained in eight out of 10 patients. ESD using GSF appears to be an easy, safe, and technically efficient method for resecting early colorectal tumors.

Clinical and endoscopic characteristics of acute haemorrhagic rectal ulcer, and endoscopic haemostatic treatment: a retrospective study of 95 patients.

AIM: Acute haemorrhagic rectal ulcer (AHRU) is characterized by sudden onset of painless and massive rectal bleeding in elderly bedridden patients who have serious illness. Endoscopic diagnosis and management of AHRU is, however, still controversial. We retrospectively investigated 95 AHRU patients to elucidate the clinical characteristics, endoscopic findings and haemostatic strategies. METHOD: Between January 1999 and March 2007, 95 patients were diagnosed with AHRU in our hospital. Medical records and colonoscopy files were reviewed. Clinical features, colonoscopic findings, haemostatic treatment and outcome of the patients were evaluated. RESULTS: Eighty per cent of the patients were bedridden at the onset. The most frequent underlying disorder was cerebrovascular disease (36.8%). Hypoalbuminaemia (< 3.5 g/dl) was seen in 92.6% of the patients. Endoscopic findings of AHRU were classified as circumferential ulcer (41.1%), linear or nearly round small ulcer(s) (44.2%), circumferential and small ulcer(s) (7.4%) and Dieulafoy-like ulcer (7.4%). Primary endoscopic haemostatic treatment was performed in 45.3% of cases. Recurrent bleeding occurred in 24.2% of patients. Permanent haemostasis was achieved by secondary endoscopic treatment in 82.6% of re-bleeding patients. CONCLUSION: Understanding the typical clinical and endoscopic findings and careful endoscopic examination are important for the accurate diagnosis of AHRU, and endoscopic haemostatic therapy may be effective for bleeding patients.

Temporal localization of osteocalcin protein during healing of tooth extraction sockets in rats.

AIM: The aim of this study was to evaluate the expression of osteocalcin protein during the alveolar bone healing process in rats. METHODS: Twenty four rats were used in this study and, after anesthetic induction, they had their right upper incisors extracted. At 7, 14, 21 and 28 days after the tooth extraction, the animals were injected 4% formaldehyde. The histological tissue pieces were colored in hematoxilin and eosin and the immunohistochemistry reaction for osteocalcin was performed. RESULTS: At seven days lesser neoformed trabeculae bone and a small quantity of osteocalcin labeling were observed. At 14 and 21 days a larger quantity of neoformed trabeculae bone and higher osteocalcin values were detected. At 28 days the largest quantity of neoformed trabeculae bone and a decrease on the amount of osteocalcin immunolabelling were noticed. CONCLUSION: According to our results and considering the limits of the present study it is possible to conclude that a greater osteocalcin expression is observed at 14 and 21 days postoperatively, characterizing the periods when intense mineralization of the bone tissue occurs during the alveolar bone healing process.

Ground-state and single-particle energies of nuclei around 16O, 40Ca, and 56Ni from realistic nucleon-nucleon forces.

We perform ab initio calculations for nuclei around 16O, 40Ca, and 56Ni using realistic nucleon-nucleon forces. In particular, 56Ni is computed as the heaviest nucleus in this kind of ab initio calculation. Ground-state and single-particle energies including three-body-cluster effects are obtained within the framework of the unitary-model-operator approach. It is shown that the CD-Bonn nucleon-nucleon potential gives quite good results close to the experimental values for all nuclei in the present work.

Single-operator method for double-balloon endoscopy: a pilot study.

Double-balloon endoscopy (DBE) is a new technique that allows diagnosis and treatment throughout the entire small intestine. We have recently developed a method that allows a single operator to perform DBE, by employing "grip and pinch" and "hold (or 'keep') and slide" techniques. This one-person method obviates the need for two operators who must cooperate closely.

An uncommon cleft subtype of unilateral cleft lip and palate.

The finding that the vomer plays a crucial role in maxillary growth suggests that the bilateral cleft configuration of unilateral cleft lip and palate (UCLP), in which the vomer is detached from the non-cleft-side secondary hard palate, negatively influences palatal development, and this hypothesis was tested. Sixty persons with complete UCLP, including those with the vomer detached from (n = 30, b-UCLP) and attached to (n = 30, u-UCLP) the secondary hard palate, were analyzed morphologically, with the use of cast models taken at 10 days, 3 mos, and 12 mos of age. The anterio-posterior palatal length at 12 mos of age in those with b-UCLP was significantly shorter than that in those with u-UCLP, by 8.7% (p < 0.05). In addition, palatal width development in the first year in those with b-UCLP was also significantly retarded. These results suggest that the uncommon bilateral cleft subtype in UCLP should be included in the cleft classification.

Comparative study of volumetric changes and trabecular microarchitecture in human maxillary sinus bone augmentation with bioactive glass and autogenous bone graft: a prospective and randomized assessment.

The aim of this study was to compare the volumetric changes and the new bone microarchitecture in human maxillary sinuses augmented with bioactive glass (Biogran) alone, bioactive glass combined with autogenous bone graft (1:1), or autogenous bone graft alone. Twelve maxillary sinuses were grafted with bioactive glass (group 1), nine with bioactive glass mixed with autogenous bone graft 1:1 (group 2), and 12 with autogenous bone graft (group 3). Patients underwent cone beam computed tomography 15days after the procedure to determine the initial volume of the graft (T1) and again 6 months later (T2). Biopsies were obtained at the time of dental implant placement and were subjected to micro-computed tomography. The volumetric change was 44.2% in group 1, 37.9% in group 2, and 45.7% in group 3 (P>0.05). The trabecular microarchitecture results showed that the materials used in groups 1 and 2 were good bone substitutes. However, the addition of 50% bioactive glass to autogenous bone graft improved the microarchitecture of the graft. Furthermore, the results for volumetric changes indicated that bioactive glass, its association with autogenous bone graft in a 1:1 ratio, and autogenous bone graft alone have similar resorption.

Measurement of anisotropic mechanical properties in porcine brain white matter ex vivo using magnetic resonance elastography.

The mechanical properties of brain tissue, particularly those of white matter (WM), need to be characterized accurately for use in finite element (FE) models of brain biomechanics and traumatic brain injury (TBI). Magnetic resonance elastography (MRE) is a powerful tool for non-invasive estimation of the mechanical properties of soft tissues. While several studies involving direct mechanical tests of brain tissue have shown mechanical anisotropy, most MRE studies of brain tissue assume an isotropic model. In this study, an incompressible transversely isotropic (TI) material model parameterized by minimum shear modulus (µ2), shear anisotropy parameter (ϕ), and tensile anisotropy parameter (ζ) is applied to analyze MRE measurements of ex vivo porcine white matter (WM) brain tissue. To characterize shear anisotropy, "slow" (pure transverse) shear waves were propagated at 100, 200 and 300Hz through sections of ex vivo brain tissue including both WM and gray matter (GM). Shear waves were found to propagate with elliptical fronts, consistent with TI material behavior. Shear wave fields were also analyzed within regions of interest (ROI) to find local shear wavelengths parallel and perpendicular to fiber orientation. FE simulations of a TI material with a range of plausible shear modulus (µ2) and shear anisotropy parameters (ϕ) were run and the results were analyzed in the same fashion as the experimental case. Parameters of the FE simulations which most closely matched each experiment were taken to represent the mechanical properties of that particular sample. Using this approach, WM in the ex vivo porcine brain was found to be mildly anisotropic in shear with estimates of minimum shear modulus (actuation frequencies listed in parenthesis): µ2= 1.04 ± 0.12 kPa (at 100Hz), µ2= 1.94 ± 0.29 kPa (at 200Hz), and µ2= 2.88 ± 0.34 kPa (at 300Hz) and corresponding shear anisotropy factors of ϕ= 0.27 ± 0.09 (at 100Hz), ϕ= 0.29 ± 0.14 (at 200Hz) and ϕ= 0.34 ± 0.13 (at 300Hz). Future MRE studies will focus on tensile anisotropy, which will require both slow and fast shear waves for accurate estimation.

Requirement of nectin, but not cadherin, for formation of claudin-based tight junctions in annexin II-knockdown MDCK cells.

Adherens junctions (AJs) and tight junctions (TJs) comprise a junctional complex which plays key roles not only in cell adhesion and polarization but also in regulation of cell movement and proliferation in epithelial cells. E-Cadherin and nectin are major cell-cell adhesion molecules (CAMs) at AJs, whereas claudin is a major CAM at TJs. We have shown that the cadherin-based cell-cell adhesion is not formed in MDCK cells in which annexin II, a Ca(2+)- and phospholipid-binding protein, is knocked down. Here, we found that TJs and the nectin-based cell-cell adhesions were formed in annexin II-knockdown cells. The formation of TJs in annexin II-knockdown MDCK cells required the nectin-based cell-cell adhesion and afadin, a nectin- and actin-filament-binding protein. In addition, it required the activation of Cdc42 and Rac small G proteins and subsequent reorganization of the IQGAP1-dependent actin cytoskeleton which were induced by the nectin-based cell-cell adhesion. These results indicate that the nectin-based cell-cell adhesion and afadin, but not the cadherin-based cell-cell adhesion, are necessary for the formation of TJs and that the signaling by nectin and the subsequent reorganization of the actin cytoskeleton are also necessary for the formation of TJs under certain conditions.

Efficacy of the C-terminal telopeptide test in predicting the development of bisphosphonate-related osteonecrosis of the jaw: a systematic review.

This systematic review evaluated the efficacy of the morning fasting serum C-terminal telopeptide (CTX) test in predicting the development of bisphosphonate-related osteonecrosis of the jaw (BRONJ). A comprehensive search of studies published up to March 2016, and listed in the PubMed/MEDLINE, Web of Science, and Cochrane Library databases, was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. This review has been registered in the PROSPERO international prospective register of systematic reviews (CRD42016036717). The search identified 542 publications; eight studies were finally deemed eligible for inclusion according to the study criteria. These studies included a total 1442 patients (mean age 66.7 years). The most prescribed drug was alendronate, with osteoporosis being the most frequent indication for the prescription of bisphosphonates. Tooth extraction was the most common trigger for BRONJ. Of all patients evaluated after bisphosphonate treatment, only 24 (1.7%) developed BRONJ. All eight of the selected studies found that CTX levels were not predictive of the development of BRONJ. In conclusion, this systematic review indicates that the CTX test has no predictive value in determining the risk of osteonecrosis in patients taking bisphosphonates.