Structure and activation mechanism of the rice Salt Overly Sensitive 1 (SOS1) Na+/H+ antiporter.

Salinity is one of the most severe abiotic stresses that adversely affect plant growth and agricultural productivity. The plant Na+/H+ antiporter Salt Overly Sensitive 1 (SOS1) located in the plasma membrane extrudes excess Na+ out of cells in response to salt stress and confers salt tolerance. However, the molecular mechanism underlying SOS1 activation remains largely elusive. Here we elucidate two cryo-electron microscopy structures of rice (Oryza sativa) SOS1, a full-length protein in an auto-inhibited state and a truncated version in an active state. The SOS1 forms a dimeric architecture, with an NhaA-folded transmembrane domain portion in the membrane and an elongated cytosolic portion of multiple regulatory domains in the cytoplasm. The structural comparison shows that SOS1 adopts an elevator transport mechanism accompanied by a conformational transition of the highly conserved Pro148 in the unwound transmembrane helix 5 (TM5), switching from an occluded conformation in the auto-inhibited state to a conducting conformation in the active state. These findings allow us to propose an inhibition-release mechanism for SOS1 activation and elucidate how SOS1 controls Na+ homeostasis in response to salt stress.

The self-medication behaviors of residents and the factors related to the consideration of drug efficacy and safety-A cross-sectional study in China.

Background: Over-the-counter (OTC) drugs facilitates residents self-medication. However, inappropriate self-medications have become a serious problem in China and even all over the world. Objectives: To make an investigation on the current status of Chinese residents' self-medication behaviors and important considerations, and to explore the factors related to the considerations of drug efficacy and safety. Design: A quantitative, cross-sectional study. Methods: Multi-stage sampling was used to conduct a cross-sectional investigation in China 22 provinces, 5 autonomous regions and 4 municipalities directly under the Central Government. State that an interviewer-administrated questionnaire, was used for data collection. The questionnaire that was used in the investigation included demographic sociological characteristics, health literacy scale-short form (HLS-SF), the 10-item Big Five Inventory (BFI-10), the EuroQol-5D visual analogue scale (EQ-5D VAS), self-medication status and important considerations when self-medicating. Descriptive statistics were performed, and the Chi-square test was used for univariate analysis. Log-binomial regression was used for multivariate analysis on whether residents regard drug efficacy or safety as an important consideration. Results: 9256 respondents were included in the data analysis. The self-medication rate of Chinese adults was as high as 99.1%. Paracetamol and other analgesics were the most common types of OTC medication that respondents purchased, followed by vitamins/minerals. Medical staff recommendations, drug safety and efficacy were the top three important considerations. The residents in the east, central and western regions who consider safety is 63.5%, 61.5%, and 66.8% respectively. The proportion of curative effect was 60.2%, 55.7%, and 61.4% respectively. Log-binomial regression showed that western respondents, retired people, those who mainly used ways including basic medical insurance for employees, commercial medical insurance, free medical treatment to cover their medical cost, respondents with high neuroticism, high health literacy were more likely to consider drug safety as an important factor (p < 0.05). Eastern respondents, employed, main way of medical expenses borne was Out-of-pocket Payment, those with chronic disease were more likely to consider drug efficacy as an important factor (p < 0.05). Female, respondents with high levels of agreeableness, conscientiousness, openness, and self-rated health status were more likely to regard both drug safety and efficacy as important considerations (p < 0.05). Conclusion: Self-medication is practiced by most Chinese adults. Whether Chinese adults take drug efficacy or safety as an important consideration is related to their demographic and sociological characteristics, Big Five personality characteristics, health literacy and self-assessed health status. There is a need to strengthen the management of OTC drugs and public education about self-medication.

Structure and activity of SLAC1 channels for stomatal signaling in leaves.

Stomata in leaves regulate gas exchange between the plant and its atmosphere. Various environmental stimuli elicit abscisic acid (ABA); ABA leads to phosphoactivation of slow anion channel 1 (SLAC1); SLAC1 activity reduces turgor pressure in aperture-defining guard cells; and stomatal closure ensues. We used electrophysiology for functional characterizations of Arabidopsis thaliana SLAC1 (AtSLAC1) and cryoelectron microscopy (cryo-EM) for structural analysis of Brachypodium distachyon SLAC1 (BdSLAC1), at 2.97-Å resolution. We identified 14 phosphorylation sites in AtSLAC1 and showed nearly 330-fold channel-activity enhancement with 4 to 6 of these phosphorylated. Seven SLAC1-conserved arginines are poised in BdSLAC1 for regulatory interaction with the N-terminal extension. This BdSLAC1 structure has its pores closed, in a basal state, spring loaded by phenylalanyl residues in high-energy conformations. SLAC1 phosphorylation fine-tunes an equilibrium between basal and activated SLAC1 trimers, thereby controlling the degree of stomatal opening.

Diffusion tensor imaging-based research on human white matter anatomy.

The aim of this study is to investigate the white matter by the diffusion tensor imaging and the Chinese visible human dataset and to provide the 3D anatomical data of the corticospinal tract for the neurosurgical planning by studying the probabilistic maps and the reproducibility of the corticospinal tract. Diffusion tensor images and high-resolution T1-weighted images of 15 healthy volunteers were acquired; the DTI data were processed using DtiStudio and FSL software. The FA and color FA maps were compared with the sectional images of the Chinese visible human dataset. The probability maps of the corticospinal tract were generated as a quantitative measure of reproducibility for each voxel of the stereotaxic space. The fibers displayed by the diffusion tensor imaging were well consistent with the sectional images of the Chinese visible human dataset and the existing anatomical knowledge. The three-dimensional architecture of the white matter fibers could be clearly visualized on the diffusion tensor tractography. The diffusion tensor tractography can establish the 3D probability maps of the corticospinal tract, in which the degree of intersubject reproducibility of the corticospinal tract is consistent with the previous architectonic report. DTI is a reliable method of studying the fiber connectivity in human brain, but it is difficult to identify the tiny fibers. The probability maps are useful for evaluating and identifying the corticospinal tract in the DTI, providing anatomical information for the preoperative planning and improving the accuracy of surgical risk assessments preoperatively.

Creation of a female and male segmentation dataset based on Chinese Visible Human (CVH).

OBJECTIVE: Segmentation is a necessary step when creating realistic three-dimensional (3D) models. In order to build 3D models of whole body structures and have a wider lateral application, the thin sectional anatomical images of the Chinese Visible Human (CVH) dataset should be segmented. The more detailed structures are segmented to provide greater potential for wider application of the segmented images. MATERIALS AND METHODS: All the images based on the CVH male and female dataset were segmented semi-automatically using PHOTOSHOP software. This research lasted about 7 years. RESULT: In this study, 869 structures of CVH male and 860 structures of CVH female were semi-automatically segmented, and the formats for the segmented color-filled image data were PSD and PNG. In these segmented structures, nearly all skeletal muscles included muscle belly and tendon, and hollow organs included their organ walls and their lumen. Most nerve trunks, small arteries, lymph nodes, and lymph ducts were also segmented. Many surface-rendering and volume-rendering organ models were created using these segmented images. CONCLUSION: The CVH male and female images represent the normal Asian population. After segmentation, the images can be reconstructed directly in 3D and greatly facilitate the biological modeling of physical and physiological information, a great help in improving medical and biological science in China.

Glenohumeral joint tuberculosis that mimics frozen shoulder: a retrospective analysis.

BACKGROUND: Although the incidence of osteoarticular tuberculosis is increasing, glenohumeral joint tuberculosis is rare and often misdiagnosed in its early stages. Our objective was to study the incidence of the initial misdiagnosis as frozen shoulder and the duration of the prediagnostic period among patients with glenohumeral joint tuberculosis. METHODS: The clinical records of 21 patients with tuberculosis of the shoulder joint were retrospectively analyzed. RESULTS: Among the 16 patients with glenohumeral joint tuberculosis, 14 (87.5%) were initially diagnosed as having frozen shoulder instead of glenohumeral joint tuberculosis at their primary care clinics. Two patients actually showed both shoulder pain and limited range of motion, although they did not have a record of initial diagnosis with frozen shoulder. Consequently, 14 (87.5%) of the patients in our study with glenohumeral joint tuberculosis were likely misdiagnosed as having frozen shoulder. On the other hand, this group accounted for 3.6% (n = 16) of 450 patients who, during the same period, had been initially diagnosed with frozen shoulder at our institution. The mean prediagnostic period to attain the final, correct diagnosis of glenohumeral joint tuberculosis for this group was 14.5 months. CONCLUSION: It appears that misdiagnosis is common and early diagnosis of tubercular infection in the glenohumeral joint has become increasingly difficult. Glenohumeral joint tuberculosis should be suspected in cases of longstanding pain in the shoulder. It is necessary to re-examine these frozen shoulder patients with repeated plain radiographs followed by further imaging studies, especially magnetic resonance imaging, if conservative therapy fails.

MRI findings for frozen shoulder evaluation: is the thickness of the coracohumeral ligament a valuable diagnostic tool?

BACKGROUND: Recent studies have demonstrated that the coracohumeral ligament (CHL) is shortened and thickened in a frozen shoulder. We analyzed the rate in CHL visualization between patients with frozen shoulder and normal volunteers using Magnetic Resonance Imaging (MRI) to determine the CHL thickness in the patients with a frozen shoulder. METHODS AND FINDINGS: There were 72 shoulder joints in 72 patients (50 femles and 22 males with a mean age of 53.5 years) with clinical evidence and MR imaging evidence of frozen shoulder. These were prospectively analyzed to identify and measure the maximum thickness of the CHL. The control group, which included 120 shoulder joints in 60 normal volunteer individuals (30 females and 30 males with a mean age of 50.5 years) was also referred for MR imaging. A chi-square test was used to analyze the data of the rate of CHL visualization between the patients with frozen shoulder and the control group. A two-way ANOVA was used to analyze the mean maximal thickness of CHL. The CHL was visualized in 110 out of 120 shoulders in the control group (91.7%), and in 57 out of 72 shoulders for the frozen shoulder group (79.2%), there was significant difference, using a chi-square test (P<0.05). The CHL was not visualized in 10 out of 120 shoulders in the control group (8.3%), and 15 out of 72 shoulders in the frozen shoulder group (20.8%), there was a significant difference (P<0.05). The CHL thickness (3.99±1.68 mm) in the patients with frozen shoulder was significantly greater than that thickness (3.08±1.32 mm) in the control group, using a two-way ANOVA (P<0.001). The CHL thickness (3.52±1.52 mm, n = 97) in the female shoulders was no significantly greater than that thickness (3.22±1.49 mm, n = 70) in the male shoulders, using a two-way ANOVA (P>0.05). CONCLUSIONS: MR Imaging is a satisfactory method for CHL depiction, and a thickened CHL is highly suggestive of frozen shoulder.

Changes of brain structure and function in ADHD children.

To explore the changes of brain structure and function in attention-deficit/hyperactivity disorder (ADHD), fifteen ADHD patients (inattention subtype) and 15 normal control participants were recruited, the brain structure and function of these subjects were investigated by combining structural magnetic resonance imaging (MRI), diffusion tensor imaging and resting-state functional MRI. The results showed that ADHD patients had a significant decrease in the volume of the white matter (P = 0.04), and a trend toward decreased volume of brain structures except for the putamen and globus pallidus. The visualization of statistical difference maps of the cortical thickness showed that ADHD patients had focal thinning in bilateral frontal regions and the right cingulate cortex (P < 0.05 uncorrected, except for a cluster threshold of 10 voxels). Statistical analysis of the FA maps revealed that ADHD patients had significantly decreased FA in the forceps minor, the internal capsule, the corona radiata, the splenium of the corpus callosum, and the bilateral basal ganglia (P < 0.05 uncorrected as above). ADHD patients had significantly decreased functional connectivity in the anterior cingulate cortex, posterior cingulate cortex, lateral prefrontal cortex, left precuneus and thalamus, but increased functional connectivity in bilateral posterior medial frontal cortex in the default mode network (P < 0.05 uncorrected as above). Our results provide new insights into the changes of the brain structure and function in ADHD, which suggests that alterations in the brain structural and functional connectivity might implicate the pathophysiology of ADHD.

A novel technique for three-dimensional reconstruction for surgical simulation around the craniocervical junction region.

Performing surgeries on the craniocervical junction presents a technical challenge for operating surgeons. Three-dimensional (3D) reconstruction and surgical simulation have improved the efficacy and success rate of surgeries. The aim of this study was to create a 3D, digitized visible model of the craniocervical junction region to help realize accurate simulation of craniocervical surgery on a graphic workstation. Transverse sectional anatomy data for the study were chosen from the first Chinese visible human. Manual axial segmentation of the skull base, cervical spine, cerebellum, vertebral artery, internal carotid artery, sigmoid sinus, internal jugular vein, brain stem, and spinal cord were carried out by using Photoshop software. The segmented structures were reconstructed in 3 dimensions with surface and volume rendering to accurately display 3D models spatially. In contrast to conventional 3D reconstruction techniques that are based on computed tomography and magnetic resonance imaging Digital Imaging and Communications in Medicine (DICOM) inputs and provide mostly osseous details, this technique can help to illustrate the surrounding soft tissue structure and provide a realistic surgical simulation. The reconstructed 3D model was successfully used in simulating complex procedures in the virtual environment, including the transoral approach, bone drillings, and clivus resection.

Creation of the digital three-dimensional model of the prostate and its adjacent structures based on Chinese visible human.

We managed to provide three-dimensional digitized visible model of the prostate and its adjacent structures and to provide morphological data for imaging diagnosis and male urological surgery. With 3D-DOCTOR software, the contour line of prostate and its adjacent structures including rectum, bladder, male urethra, ureter, seminal vesicle, ductus deferens, ejaculatory ducts, obturator internus, levator ani, coccygeus, male pelvis, femur, prostatic nervous and venous plexus, internal and external iliac arteries were segmented from the Chinese visible human (CVH)-1 data set and the three-dimensional surfaces of intrapelvic visceras were successfully and accurately reconstructed via surface rendering, which can also be manipulated individually and interactively. Combined with AMIRA software, surface rendering reconstructed model of male urological organs and its adjacent structures via volume rendering reconstruction can be displayed together clearly and actually. It provides a learning tool of practicing virtual anatomy and virtual urological surgery for medical students and younger surgeons.

Segmentation and three-dimension reconstruction of Chinese digitized human cerebrum.

OBJECTIVE: A 3D digitized visible model of human cerebrum was built to provide anatomical structure for making plans of cerebral surgical operation and realizing accurate simulation of cerebrum on computer. METHODS: Transverse sectional anatomy data of the cerebrum were chosen from the first Chinese visible human (one male and one female). Semi-automated segmentation and Photoshop software were selected to segment cerebral cortex, white matter, basal nuclei, lateral ventricle, hippocampus, etc. On personal computer, the segmented structures were reconstructed in 3D with volume rendering reconstruction and surface rendering reconstruction. RESULTS: Two accurately segmented images of the main structures of cerebrum were completed. The reconstructed structures can be displayed singly, in small groups or as a whole and can be continuously rotated in 3D space at different velocities. CONCLUSION: Combining volume-rendering reconstruction with surface rendering reconstruction overcomes the defects of surface rendering reconstruction that lack of internal anatomical information, which provides a new method for 3D reconstruction. The reconstructed cerebrum and the main internal structures are realistic, which demonstrates the natural shape and exact position of the structures. It provides an accurate model for the automated segmentation algorithmic study and provides a digitized anatomical mode of cerebrum.

[Visualization and thin sectional anatomy of the laryngeal cartilages].

OBJECTIVE: To establish digitized visible model of the laryngeal cartilages of the visible human, providing morphological data for image diagnosis and laryngectomy. METHODS: Cross-sectional images of fresh tissues from the Chinese visible human data set were reviewed, and the laryngeal cartilages structures data were used, the data was on a section-by-section basis. Three-dimensional computer reconstructions of the laryngeal cartilages were generated from these data by surface rendering on a SGI workstation. RESULTS: The digital images from the visible human offer unique insights into the complex anatomy and ossification of the laryngeal cartilages, the quality of the computerized 3D-reconstructed images was distinct and perfect. CONCLUSIONS: The visible human data set can provide complete and accurate data The digitized model of the laryngeal cartilages offer unique insights into the laryngeal anatomy, could be used for resident education, rehearsal of an unfamiliar surgery and for developing a new surgical approach.

The Chinese Visible Human (CVH) datasets incorporate technical and imaging advances on earlier digital humans.

We report the availability of a digitized Chinese male and a digitzed Chinese female typical of the population and with no obvious abnormalities. The embalming and milling procedures incorporate three technical improvements over earlier digitized cadavers. Vascular perfusion with coloured gelatin was performed to facilitate blood vessel identification. Embalmed cadavers were embedded in gelatin and cryosectioned whole so as to avoid section loss resulting from cutting the body into smaller pieces. Milling performed at -25 degrees C prevented small structures (e.g. teeth, concha nasalis and articular cartilage) from falling off from the milling surface. The male image set (.tiff images each of 36 Mb) has a section resolution of 3072 x 2048 pixels ( approximately 170 micro m, the accompanying magnetic resonance imaging and computer tomography data have a resolution of 512 x 512, i.e. approximately 440 micro m). The Chinese Visible Human male and female datasets are available at http://www.chinesevisiblehuman.com. (The male is 90.65 Gb and female 131.04 Gb). MPEG videos of direct records of real-time volume rendering are at: http://www.cse.cuhk.edu.hk/~crc

Creation of the Chinese visible human data set.

The United States Visible Human Project (VHP) created a digital image data set of complete human male (data acquisition finished in November 1994) and female (data acquisition finished in December 1995) cadavers in magnetic resonance imaging (MRI), computed tomography (CT), and anatomical (anatomic serial section) modes. VHP aroused worldwide enthusiasm for Visible Human Research (VHR), and the data set is being used in a variety of research and educational domains. The Visible Korean Human (VKH) male was produced in March 2001. To accelerate worldwide VHR and to promote virtual anatomy as a revolutionary break with conventional anatomy, more visible human data sets representative of different populations of the world are in demand. The Chinese Visible Human (CVH) male (created in October 2002) and female (created in February 2003) project achieved greater integrity of images, easier blood vessel identification, and were free of organic lesion (unlike the other visible human projects). We performed data acquisition, three-dimensional (3D) reconstruction, and visualization with improved technology to create CVH male and female. CVH is the first volumetric data representing a complete normal adult human male and female of an Asian population. This article presents the history of Chinese Visible Human cadavers and the methods and technology used to produce the data set.