Rotation Of Complex Research Articles

Mitochondrial Inhibitory Factor Protein 1 Functions as an Endogenous Inhibitor for Coupling Factor 6.

Coupling factor 6 (CF6) forces a counter-clockwise rotation of plasma membrane F1 Fo complex unlike a proton-mediated clockwise rotation in the mitochondria, resulting in ATP hydrolysis, proton import, and apoptosis. Inhibitory peptide 1 (IF1) inhibits a unidirectional counter-clockwise rotation of F1 Fo complex without affecting ATP synthesis by a clockwise rotation. We tested the hypothesis that IF1 may antagonize the biological action of CF6 in human embryonic kidney 293 cells. We generated mature and immature IF1 expression vectors and those labeled with GFP at the C-terminus. In the immature IF1-GFP overexpressing cells, the mitochondrial network of IF1-GFP was newly found at the plasma membrane after peripheral translocation, whereas in mature IF1-GFP transfected cells, a less punctuate rather homogenous pattern was found in the cytoplasm. IF1 protein was detected in the exosome fraction of culture media, and it was enhanced by mature or immature IF1 transfection. Extracellular ATP hydrolysis was enhanced by CF6, whereas immature or mature IF1 transfection suppressed ATP hydrolysis in response to CF6. Intracellular pH was decreased by CF6 but was unchanged after immature IF1 transfection. CF6-induced increase in apoptotic cells was blocked by immature or mature IF1, being accompanied by protein kinase B (PKB) phosphorylation. IF1 antagonizes the pro-apoptotic action of CF6 by relief of intracellular acidification and resultant phosphorylation of PKB. Given the widespread biological actions of CF6, the physiological and pathological functions of IF1 may be expected to be complex. J. Cell. Biochem. 117: 1680-1687, 2016. © 2015 Wiley Periodicals, Inc.

Development of a Robotic Assembly for Analyzing the Instantaneous Axis of Rotation of the Foot Ankle Complex.

Ankle instantaneous axis of rotation (IAR) measurements represent a more complete parameter for characterizing joint motion. However, few studies have implemented this measurement to study normal, injured, or pathological foot ankle biomechanics. A novel testing protocol was developed to simulate aspects of in vivo foot ankle mechanics during mid-stance gait in a human cadaveric specimen. A lower leg was mounted in a robotic testing platform with the tibia upright and foot flat on the baseplate. Axial tibia loads (ATLs) were controlled as a function of a vertical ground reaction force (vGRF) set at half body weight (356 N) and a 50% vGRF (178 N) Achilles tendon load. Two specimens were repetitively loaded over 10 degrees of dorsiflexion and 20 degrees of plantar flexion. Platform axes were controlled within 2 microns and 0.008 degrees resulting in ATL measurements within ±2 N of target conditions. Mean ATLs and IAR values were not significantly different between cycles of motion, but IAR values were significantly different between dorsiflexion and plantar flexion. A linear regression analysis showed no significant differences between slopes of plantar flexion paths. The customized robotic platform and advanced testing protocol produced repeatable and accurate measurements of the IAR, useful for assessing foot ankle biomechanics under different loading scenarios and foot conditions.

Architecture of the Rix1-Rea1 checkpoint machinery during pre-60S-ribosome remodeling.

Ribosome synthesis is catalyzed by ∼200 assembly factors, which facilitate efficient production of mature ribosomes. Here, we determined the cryo-EM structure of a Saccharomyces cerevisiae nucleoplasmic pre-60S particle containing the dynein-related 550-kDa Rea1 AAA(+) ATPase and the Rix1 subcomplex. This particle differs from its preceding state, the early Arx1 particle, by two massive structural rearrangements: an ∼180° rotation of the 5S ribonucleoprotein complex and the central protuberance (CP) rRNA helices, and the removal of the 'foot' structure from the 3' end of the 5.8S rRNA. Progression from the Arx1 to the Rix1 particle was blocked by mutational perturbation of the Rix1-Rea1 interaction but not by a dominant-lethal Rea1 AAA(+) ATPase-ring mutant. After remodeling, the Rix1 subcomplex and Rea1 become suitably positioned to sense correct structural maturation of the CP, which allows unidirectional progression toward mature ribosomes.

How does transmembrane electrochemical potential drive the rotation of Fo motor in an ATP synthase?

While the field of ATP synthase research has a long history filled with landmark discoveries, recent structural works provide us with important insights into the mechanisms that links the proton movement with the rotation of the Fo motor. Here, we propose a mechanism of unidirectional rotation of the Fo complex, which is in agreement with these new structural insights as well as our more general ΔΨ-driving hypothesis of membrane proteins: A proton path in the rotor-stator interface is formed dynamically in concert with the rotation of the Fo rotor. The trajectory of the proton viewed in the reference system of the rotor (R-path) must lag behind that of the stator (S-path). The proton moves from a higher energy site to a lower site following both trajectories simultaneously. The two trajectories meet each other at the transient proton-binding site, resulting in a relative rotation between the rotor and stator. The kinetic energy of protons gained from ΔΨ is transferred to the c-ring as the protons are captured sequentially by the binding sites along the proton path, thus driving the unidirectional rotation of the c-ring. Our ΔΨ-driving hypothesis on Fo motor is an attempt to unveil the robust mechanism of energy conversion in the highly conserved, ubiquitously expressed rotary ATP synthases.

Three-dimensional evaluation of superior airway space after orthognathic surgery with counterclockwise rotation of the maxillomandibular complex

Three-dimensional evaluation of superior airway space after orthognathic surgery with counterclockwise rotation of the maxillomandibular complex

Posterior Pharyngeal Airway in Clockwise Rotation of Maxillomandibular Complex Using Surgery-first Orthognathic Approach.

Background:Because obstructive sleep apnea is known to be an important preexisting factor causing chronic disease, many investigations have been done recently. There have been few reports regarding the posterior pharyngeal airway after clockwise rotation of maxillomandibular complex. Because the 2-jaw surgery in class III patients could cause obstructive sleep apnea or snoring, we investigated the posterior pharyngeal airway change of the clockwise maxillomandibular complex in the surgery-first orthognathic approach for the correction of class III dentofacial deformities.Methods:A cephalometric evaluation of 35 patients with skeletal class III deformity was performed preoperatively and postoperatively. Three measurements of the posterior pharyngeal airway space (nasopharynx, oropharynx, and hypopharynx) and hyoid bone positions (the distance from palatal plane to hyoid bone and the distance from mandibular plane to the hyoid bone) were evaluated and correlated with the skeletal movement of the jaws using imaging software (V-Ceph, Osstem, Seoul, Korea).Results:The preoperative airway space turned out to be enlarged in class III dentofacial deformities compared with those of normal persons. The preoperative P1, P2, and P3 in our cohort were increased and posterior nasal spine to hyoid bone and mandibular plane to hyoid bone were decreased compared with those of normal person’s data because the cohort consists of prognathic patients where the mandible is located in forward position. After 6 months, most values were nearly normal.Conclusion:Orthognathic surgery based on clockwise rotation of maxillomandibular complex did not cause severe posterior airway space changes at 6 months postoperation.

Skeletal stability in orthognathic surgery: evaluation of methods of rigid internal fixation after counterclockwise rotation in patients with class II deformities

Our aim was to assess the influence of internal fixation in skeletal stability on patients who had had counterclockwise rotation of the maxillomandibular complex and mandibular advancement procedures. We studied 60 records of 20 patients (14 female, 6 male), mean (range) age at operation 29 (16-50) years. The mean (range) postoperative follow-up was 15 (8-24) months. Sixty standard lateral cephalometric radiographs were randomly traced and digitised by one senior radiologist to estimate surgical and postoperative changes. Patients were divided into two groups, the first group (n=10) of which had fixation with only 2.0 system plates (2 plates with monocortical screws alone) and the second (n=10) of which had hybrid fixation (1 plate with monocortical screws and 2 or 3 bicortical bone screws). During operation the change in the mean occlusal plane with counterclockwise rotation was 9.4° (range -17.3 to -2.5mm). The maxilla moved forward and upward. All the anterior mandibular measurements had advanced horizontally, the mean (range) being 17 (6.4 to 9.9) mm for the pogonion, and 17.6 (6.0 to 30.7) mm for the menton. At the longest follow-up period, there were significant long-term changes, but these were clinically acceptable (<2mm). There was no significant difference between the two groups in postoperative stability or in the magnitude of the advancement and stability.

Three-dimensional evaluation of superior airway space after orthognathic surgery with counterclockwise rotation and advancement of the maxillomandibular complex in Class II patients

The aim of this study was to assess changes in the superior airway space (SAS) in Class II patients undergoing orthognathic surgery with counterclockwise rotation of the maxillomandibular complex (MMC). A total of 23 patients (15 females and 8 males; mean age, 33 years) with symptoms of respiratory disease (mouth breathing) were studied. The patients were subjected to computed tomography analyses at two time intervals: T1 (preoperatively) and T2 (postoperative minimum of 6 months). The computed tomography images were exported to Dolphin Imaging 11.5 software to measure the surface area, minimum axial area, and volume of the SAS. The surgery (including a median mandibular advancement of 14 mm with an average rotation of 8 degrees) significantly increased the static SAS, with mean postoperative increases of 178 mm(2) in SA, 76.67 mm(2) in minimum axial area, and 10118.5 mm(3) in volume. A significant increase was also observed in the three-dimensional airspace following orthognathic surgery, which provided a greater permeability of the SAS in Class II patients. This confirmed the efficacy of this technique in the treatment of respiratory disorders.

Surgical management of congenital deformities with temporomandibular joint malformation.

This article discusses hemifacial microsomia and Treacher Collins syndrome relative to the nature of these congenital deformities as well as the clinical, radiographic, and diagnostic characteristics. These patients often have severe facial deformities with hypoplasia or aplasia of the temporomandibular joints (TMJs) and mandible. The surgical treatment options are presented, including the advantages and disadvantages of autogenous tissues versus patient-fitted total joint prostheses to reconstruct the TMJs and mandible as well as counterclockwise rotation of the maxillomandibular complex.

A simple polarimetry technique for predicting the absolute configuration of the preferred enantiomer in chiral host-guest inclusion complexes

Amethod for predicting the configuration of the preferred guest enantiomer in an inclusion complex with an optically pure host compound was developed. The method involves simply measuring the optical rotation of the host-guest inclusion complex as a whole, by means of polarimetry, and using this value in a calculation in order to obtain information about the guest configuration. The availability of standard optically pure guest materials is not required, nor is the isolation of the guest species from the hostcrystal, resulting in an attractive, inexpensive, rapid and simple procedure for this purpose. (Graphical Abstract) KEYWORDS Host-guest chemistry, polarimetry, optical rotation, supramolecular chemistry, inclusion chemistry.

Rotation technique of reduction malar plasty.

The 2 most common complications of reduction malarplasty are nonunion or malunion and cheek drooping. Because masseter muscle is attached from zygomatic process of the maxilla to inferior two thirds of the zygomatic arch, rigid fixation and intimate bone contact without creating a gap are crucial for reduction malarplasty.Mesial-clockwise rotation of the zygomaticomaxillary complex can produce intimate bone contact and facilitates reduction malarplasty.

Improved Apnea-Hypopnea Index and Lowest Oxygen Saturation After Maxillomandibular Advancement With or Without Counterclockwise Rotation in Patients With Obstructive Sleep Apnea: A Meta-Analysis

This study investigated whether patients with obstructive sleep apnea (OSA) who undergo maxillomandibular advancement (MMA) with counterclockwise (CCW) rotation compared with those who undergo MMA without CCW rotation have better outcomes. This was a systematic review with meta-analysis. The Medline and Cochrane databaseswere searched for randomized controlled trials using Medical Subject Headings. The predictor variable was operative technique, namely MMA with or without CCW rotation of the maxillofacial complex. The key outcome variables were changes in pre- and postsurgical values of pharyngeal volume measured on computed tomogram or cone-beam computed tomogram and changes in Apnea-Hypopnea Index (AHI) and lowest oxygen saturation (LSAT) values after surgery. Data were subjected to a meta-analysis based on odds ratios (OR) with 95% confidence intervals (CIs) and P values lower than .05 by χ(2) test were considered significant. Twenty-one randomized controlled trials were identified and 4 were assessed for the variables of interest. Postoperative AHI and LSAT measurements showed vast improvement. The sample was not large enough to make a correlation between pharyngeal volume changes and surgical method used. Postoperative parameters included an AHI lower than 5 (OR= 14.9; 95% CI, 2.7-83.5; P= .002), an AHI lower than 20 (OR = 114.8; 95% CI, 23.5-561.1; P <.00001), pooled results of a 50% decrease in the AHI (OR= 6.1; 95% CI, 2.2-17.0; P= .0006), and an increase greater than 90% in LSAT measurements during sleep (OR= 6.0; 95% CI, 1.8-19.9; P= .003). The funnel plot showed no evidence of publication bias. CCW-MMA or MMA in patients with OSA results in a statistically meaningful decrease in postoperative AHI and a statistically meaningful increase in postoperative LSAT.

Three-dimensional Evaluation of Superior Airway Space in Class II Patients Undergoing Orthognathic Surgery with Counterclockwise Rotation of the Maxillomandibular Complex

The aim of this retrospective study was to evaluate alterations in the superior airway space in Class II patients undergoing orthognathic surgery with counterclockwise rotation of Maxillomandibular Complex using Cone-beam computer tomography (CBCT) scans and the software program Dolphin Imaging® 11.5 (Dolphin Imaging and Management Solutions, Chatsworth,CA,USA) for three-dimensional measurement of surface area (AS) , minimum axial area (MAA) and volume (VOL) of the superior airway space. Twenty-three patients with a history of respiratory disorders were assessed, 15 females and 8 males with a mean age of 34.04 years (16 to 64 years). They were subjected to computer tomographies analyzes at two time intervals: T1 (preoperatively) and T2 (postoperative minimum of 6 months). The data obtained were tabulated and statistically analyzed. A t-Student and Wilcoxon paired test was used, with statistically significant results being obtained (p< 0.05), regarding an increase in superior airway space in patients undergoing orthognathic surgery with counterclockwise rotation of the MMC in this study.

Structural basis of bacterial protein translation elongation

Recently, better understanding of ribosome function has been achieved through structural determination. These results provided a wealth of information on how genetic codes are precisely translated into proteins that control life, as well as established the platform to put ribosome as one of the richest validated targets for antibacterial drug discovery. We discovered a new ribosome crystal form obtained from ribosome lacking subunit L9, which allows crystallization of the ribosome in the presence of elongation factors Tu and G (EF-Tu/EF-G), trapped by antibiotics kirromycin and fusidic acid, respectively. These structures for the first time at atomic level offer insight into the molecular mechanism of protein elongation, which lies at the heart of translation. In each elongation cycle, EF-G facilitates the movement of tRNA-mRNA by one codon, which is coupled to the ratchet-like rotation of the ribosome complex and is triggered by EF-G-mediated GTP hydrolysis. The structure of pre-translocational ribosome bound to EF-G trapped with a GTP analogue, sheds light on how the positioning of the catalytic residue His87 into the active site is coupled to the hydrophobic gate opening which involves the sarcin-ricin loop (SRL) and domain III of EF-G. These results provide the structural basis for the GTPase activation of EF-G. After translocation, a cognate deacylated tRNA can only move together with the codon into the ribosomal E site. We also determined the structure of a cognate tRNA bound to the ribosomal E site, representing an authentic ribosome elongation complex. Quality control in protein translation by bacterial toxin has been associated with ribosome stalling and rescue system that is critical for cell to adapt environmental stress. Finally, I will introduce our structural progress on bacterial toxin bound to ribosome towards understanding of a classical acid-base catalysis mechanism.

Assessment of Skeletal Stability After Counterclockwise Rotation of the Maxillomandibular Complex in Patients With Long-Face Pattern Subjected to Orthognathic Surgery

The aim of this study was to evaluate the long-term skeletal stability of counterclockwise maxillomandibular complex rotation in patients undergoing orthognathic surgery for long-face pattern. This retrospective study consisted of 10 patients who underwent the procedure between September 2002 and April 2008. To assess the skeletal stability, 30 preoperative (T1), recent postoperative (T2), and late postoperative (T3) cephalometric radiographs of the 10 patients were digitized and traced. To measure the stability in the occlusal plane and mandibular plane, the cephalometric points and planes were determined 3 times. In the long term, on average, the A-point moved 0.21 mm backward (AYT3-AYT2), the B-point moved 0.57 mm backward (BYT3-BYT2), and the posterior nasal spine moved 0.31 mm backward (PNSYT3-PNSYT2). On average, the anterior maxillary area (A-point) moved 0.14 mm downward (AXT3-AXT2), the mandible (B-point) moved 0.07 mm downward (BXT3-BXT2), and the posterior nasal spine moved approximately 0.18 mm upward (PNSXT3-PNSXT2). The occlusal plane increased by 0.75 degrees (OPT3-OPT2), and the mandibular plane increased by 0.45 degrees (MPT3-MPT2). It was observed that the counterclockwise rotation of the maxillomandibular complex produces stable results in patients with long-face pattern undergoing orthognathic surgery.

Evaluation of three-dimensional condylar morphology in patients undergoing orthognathic surgery with counterclockwise rotation of the maxillomandibular complex

Evaluation of three-dimensional condylar morphology in patients undergoing orthognathic surgery with counterclockwise rotation of the maxillomandibular complex

Minimum Presurgical Orthodontic Treatment with Two Jaw Surgery Combined with Anterior Segmental Osteotmy in Skeletal Class II Malocclusion: A Case Report

This case report describes the treatment of a 23-year-old woman who had lip protrusion with gummy smile and mentalis muscle strain. Orthognathic surgery was performed in conjunction with orthodontics. Minimum dental decompensation was performed with presurgical orthodontics followed by an anterior segmental osteotomy for the majority of dental decompensation. Counterclockwise rotation of the maxillomandibular complex was applied by LeFort I osteotomy, and bilateral sagittal split ramus osteotomies with anterior segmental osteotomy to achieve overall facial balance. The active treatment period was 15 months. Stable occlusion and skeletal relationship were observed after a 10-month follow-up period.

Does the reductive mastopexy with implant approach prevent the late bottoming out?

After breast surgery, the late upward rotation of the nipple-areola complex and the increase of the fullness at the lower pole of the breast have been defined as a bottoming out. Although several studies have focused on the safety and complication rate of the one-stage augmentation/mastopexy, there is no clear recommendation on how to prevent the late complication of ‘bottoming out’. A retrospective review was conducted of 48 consecutive patients who underwent one-stage mastopexy/augmentation using the reductive approach. When performing the one-stage augmentation/mastopexy procedure, using the reductive mastopexy approach does effectively reduce the internal tension from the lower pole of the breast and helps to prevent the occurrence of bottoming out.

Structure of EF-G–ribosome complex in a pretranslocation state

In protein synthesis, elongation factor G (EF-G) facilitates movement of tRNA-mRNA by one codon, which is coupled to the ratchet-like rotation of the ribosome complex and is triggered by EF-G-mediated GTP hydrolysis. Here we report the structure of a pretranslocational ribosome bound to Thermus thermophilus EF-G trapped with a GTP analog. The positioning of the catalytic His87 into the active site coupled to hydrophobic-gate opening involves the 23S rRNA sarcin-ricin loop and domain III of EF-G and provides a structural basis for the GTPase activation of EF-G. Interactions of the hybrid peptidyl-site-exit-site tRNA with ribosomal elements, including the entire L1 stalk and proteins S13 and S19, shed light on how formation and stabilization of the hybrid tRNA is coupled to head swiveling and body rotation of the 30S as well as to closure of the L1 stalk.

Biased Brownian stepping rotation of FoF1-ATP synthase driven by proton motive force

FoF1-ATP synthase (FoF1) produces most of the ATP in cells, uniquely, by converting the proton motive force (pmf) into ATP production via mechanical rotation of the inner rotor complex. Technical difficulties have hampered direct investigation of pmf-driven rotation, which are crucial to elucidating the chemomechanical coupling mechanism of FoF1. Here we develop a novel supported membrane system for direct observation of the rotation of FoF1 driven by pmf that was formed by photolysis of caged protons. Upon photolysis, FoF1 initiated rotation in the opposite direction to that of the ATP-driven rotation. The step size of pmf-driven rotation was 120°, suggesting that the kinetic bottleneck is a catalytic event on F1 with threefold symmetry. The reaction equilibrium was slightly biased to ATP synthesis like under physiological conditions, and FoF1 showed highly stochastic behaviour, frequently making a 120° backward step. This new experimental system would be applicable to single-molecule study of other membrane proteins.