The Dof transcription factor COG1 acts as a key regulator of plant biomass by promoting photosynthesis and starch accumulation.

Photosynthetic efficiency is the primary determinant of crop yield, including vegetative biomass and grain yield. Manipulation of key transcription factors known to directly control photosynthetic machinery can be an effective strategy to improve photosynthetic traits. In this study, we identified an Arabidopsis gain-of-function mutant, cogwheel1-3D, that shows a significantly enlarged rosette and increased biomass compared with wild-type plants. Overexpression of COG1, a Dof transcription factor, recapitulated the phenotype of cogwheel1-3D, whereas knocking out COG1 and its six paralogs resulted in a reduced rosette size and decreased biomass. Transcriptomic and quantitative reverse transcription polymerase chain reaction analyses demonstrated that COG1 and its paralogs were required for light-induced expression of genes involved in photosynthesis. Further chromatin immunoprecipitation and electrophoretic mobility shift assays indicated that COG1 can directly bind to the promoter regions of multiple genes encoding light-harvesting antenna proteins. Physiological, biochemical, and microscopy analyses revealed that COG1 enhances photosynthetic capacity and starch accumulation in Arabidopsis rosette leaves. Furthermore, combined results of bioinformatic, genetic, and molecular experiments suggested that the functions of COG1 in increasing biomass are conserved in different plant species. These results collectively demonstrated that COG1 acts as a key regulator of plant biomass by promoting photosynthesis and starch accumulation. Manipulating COG1 to optimize photosynthetic capacity would create new strategies for future crop yield improvement.

The EPFL-ERf-SERK signaling controls integument development in Arabidopsis.

As the seed precursor, the ovule produces the female gametophyte (or embryo sac), and the subsequent double fertilization occurs in it. The integuments emerge sequentially from the integument primordia at the early stages of ovule development and finally enwrap the embryo sac gradually during gametogenesis, protecting and nursing the embryo sac. However, the mechanisms regulating integument development are still obscure. In this study, we show that SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASES (SERKs) play essential roles during integument development in Arabidopsis thaliana. The serk1/2/3 triple mutant shows arrested integuments and abnormal embryo sacs, similar defects also found in the triple loss-of-function mutants of ERECTA family (ERf) genes. Ovules of serk1/2/3 er erl1/2 show defects similar to er erl1/2 and serk1/2/3. Results of yeast two-hybrid analyses, bimolecular fluorescence complementation (BiFC) analyses, and co-immunoprecipitation assays demonstrated that SERKs interact with ERf, which depends on EPIDERMAL PATTERNING FACTOR-LIKE (EPFL) family small peptides. The sextuple mutant epfl1/2/3/4/5/6 shows integument defects similar to both of er erl1/2 and serk1/2/3. Our results demonstrate that ERf-SERK-mediated EPFL signaling orchestrates the development of the female gametophyte and the surrounding sporophytic integuments.

SERKs regulate embryonic cuticle integrity through the TWS1-GSO1/2 signaling pathway in Arabidopsis.

The embryonic cuticle integrity is critical for the embryo to separate from the neighboring endosperm. The sulfated TWISTED SEED1 (TWS1) peptide precursor generated in the embryo diffuses through gaps of the nascent cuticle to the surrounding endosperm, where it is cleaved by ABNORMAL LEAF SHAPE1 (ALE1) and becomes an active mature form. The active TWS1 is perceived by receptor-like protein kinases GASSHO1 (GSO1) and GSO2 in the embryonic epidermal cells to start the downstream signaling and guide the formation of an intact embryonic cuticle. However, the early signaling events after TWS1 is perceived by GSO1/2 are still unknown. Here, we report that serk1/2/3 embryos show cuticle defects similar to ale1, tws1, and gso1/2. Genetic and biochemical analyses were performed to dissect the signaling pathway mediated by SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASEs (SERKs) during cuticle development. SERKs function with GSO1/2 in a common pathway to monitor the integrity of the embryonic cuticle. SERKs interact with GSO1/2, which can be enhanced dramatically by TWS1. The phosphorylation levels of SERKs and GSO1/2 rely on each other and can respond to and be elevated by TWS1. Our results demonstrate that SERKs may function as coreceptors of GSO1/2 to transduce the TWS1 signal and ultimately regulate embryonic cuticle integrity.

A CLE-BAM-CIK signalling module controls root protophloem differentiation in Arabidopsis.

Exogenous application of CLAVATA3 (CLV3)/EMBRYO SURROUNDING REGION (CLE) peptides suppresses protophloem differentiation and leads to the consumption of the proximal root meristem. However, the exact CLE peptides and the corresponding receptor complex regulating protophloem differentiation have not yet been clarified. Through expression pattern and phylogenetic analyses, CLE25/26/45 were identified as candidate peptides. Further genetic analyses, physiological assays and specific protophloem marker observations indicated that CLE25/26/45, BARELY ANY MERISTEM1/3 (BAM1/3) and CLV3 INSENSITIVE KINASEs (CIKs) are involved in regulating protophloem differentiation. The cle25 26 45 and cik2 3 4 5 6 mutation can greatly rescue the root defects of brevis radix (brx) and octopus (ops) mutants. The protophloem differentiation and proximal root meristem consumption of clv1 bam1 3 and cik2 3 4 5 6 were insensitive to CLE25/26/45 treatments. cle25 26 45, clv1 bam1 3 and cik2 3 4 5 6 displayed similar premature protophloem. In addition, CLE25/26/45 induced the interactions between BAMs and CIKs in vivo. Furthermore, CLE25/26/45 enhanced the phosphorylation levels of CIKs, which were greatly impaired in clv1 bam1 3 mutant. Our work clarifies that the CLE25/26/45-BAM1/3-CIK2/3/4/5/6 signalling module genetically acts downstream of BRX and OPS to suppress protophloem differentiation.

[Nucleic acid aptamer-based traditional Chinese medicine application:therapy,targeting and diagnosis].

Nucleic acid aptamers, broad-spectrum target-specific single-stranded oligonucleotides, serve as molecules in targeted therapy, targeted delivery and disease diagnosis for the treatment of tumor or microbial infection and clinical detection. Due to the existence of components in the use of traditional Chinese medicine(TCM), the target is difficult to concentrate and the specificity of treatment is poor. The effective components of TCM are toxic components, so a highly sensitive detection method is urgently needed to reduce the toxicity problem at the same time. The combined application of TCM and modern medical treatment strategy are difficult and cannot improve the therapeutic effect. Aptamers, advantageous in biosensors, aptamer-nanoparticles for targeted drug delivery, and aptamer-siRNA chimeras, are expected to connect Chinese medicinals with nanotechnology, diagnostic technology and combined therapies. We summarized the preparation, screening, and modification techniques of nucleic acid aptamers and the biomedical applications and advantages in therapy, targeting, and diagnosis, aiming at providing a reference for the in-depth research and development in TCM.

Receptor-like Kinases in Root Development: Current Progress and Future Directions.

Cell-to-cell and cell-to-environment communications are critical to the growth and development of plants. Cell surface-localized receptor-like kinases (RLKs) are mainly involved in sensing various extracellular signals to initiate their corresponding cellular responses. As important vegetative organs for higher plants to adapt to a terrestrial living situation, roots play a critical role for the survival of plants. It has been demonstrated that RLKs control many biological processes during root growth and development. In this review, we summarize several key regulatory processes during Arabidopsis root development in which RLKs play critical roles. We also put forward a number of relevant questions that are required to be explored in future studies.

Loss of the common immune coreceptor BAK1 leads to NLR-dependent cell death.

Plants utilize a two-tiered immune system consisting of pattern recognition receptor (PRR)-triggered immunity (PTI) and effector-triggered immunity (ETI) to defend themselves against pathogenic microbes. The receptor protein kinase BAK1 plays a central role in multiple PTI signaling pathways in Arabidopsis However, double mutants made by BAK1 and its closest paralog BKK1 exhibit autoimmune phenotypes, including cell death resembling a typical nucleotide-binding leucine-rich repeat protein (NLR)-mediated ETI response. The molecular mechanisms of the cell death caused by the depletion of BAK1 and BKK1 are poorly understood. Here, we show that the cell-death phenotype of bak1 bkk1 is suppressed when a group of NLRs, ADR1s, are mutated, indicating the cell-death of bak1 bkk1 is the consequence of NLR activation. Furthermore, introduction of a Pseudomonas syringae effector HopB1, which proteolytically cleaves activated BAK1 and its paralogs via either gene transformation or bacterium-delivery, results in a cell-death phenotype in an ADR1s-dependent manner. Our study thus pinpoints that BAK1 and its paralogs are likely guarded by NLRs.

Asymmetric distribution of cytokinins determines root hydrotropism in Arabidopsis thaliana.

The phenomenon of plant root tips sensing moisture gradient in soil and growing towards higher water potential is designated as root hydrotropism, which is critical for plants to survive when water is a limited factor. Molecular mechanisms regulating such a fundamental process, however, are largely unknown. Here we report our identification that cytokinins are key signaling molecules directing root growth orientation in a hydrostimulation (moisture gradient) condition. Lower water potential side of the root tip shows more cytokinin response relative to the higher water potential side. Consequently, two cytokinin downstream type-A response regulators, ARR16 and ARR17, were found to be up-regulated at the lower water potential side, causing increased cell division in the meristem zone, which allows the root to bend towards higher water potential side. Genetic analyses indicated that various cytokinin biosynthesis and signaling mutants, including the arr16 arr17 double mutant, are significantly less responsive to hydrostimulation. Consistently, treatments with chemical inhibitors interfering with either cytokinin biosynthesis or cell division completely abolished root hydrotropic response. Asymmetrically induced expression of ARR16 or ARR17 effectively led to root bending in both wild-type and miz1, a previously known hydrotropism-defective mutant. These data demonstrate that asymmetric cytokinin distribution is a primary determinant governing root hydrotropism.

[Synovial chondromatosis of the right temporomandibular joint: report of one case].

Synovial chondromatosis of the temporomandibular joint(TMJ) is an extremely rare condition. A case of synovial chondromatosis with postoperative recurrence and involvement of base of skull was reported. The clinic pathological features, diagnosis and treatment were discussed with literature review.

[Leukoencephalopathy with cerebral calcification and cysts: a case report and review of literature].

OBJECTIVE: To improve the diagnostic ability of leukoencephalopathy with cerebral calcifications and cysts (LCC), a rare central nervous system disease. METHODS: The clinical manifestations, neuroimages and neuropathological features of a 19-year-old male patient were analyzed. A total of 20 cases from 14 literatures were reviewed. RESULT: The patient was admitted with right limb weakness, cognitive decline, headache and blurred eyesight. Head CT scan showed multiple calcifications, cysts formation and leukoencephalopathy. Brain MRI showed several cysts in bilateral hemisphere, basal ganglia, thalamus and paraventricular areas. A mural nodule was noted inside one of the cyst, which was enhanced on the contrasted MRI. The wall of the cysts was partially enhanced, but not with the fluid inside the cysts. The corresponding CT calcifications foci showed on T1 and T2 with either both hyperintensity or both hypointensity, which was also partial enhanced. Extensive leukoencephalopathy was formed around the cysts and the ventricles. But neither Cho nor NAA changed a lot on MRS. Amplitude diagram of SWI series exhibited multiple round small dark signals all over the affected areas with mixed signals showed in the phase diagram, which indicated both calcifications and microbleeding at the lesions. Neuropathological examinations found no tumor cells in the operated cyst, and showed angiomatous small blood cells were dominant in the cyst wall. Hyaline degenerations, microcalcifications and hemosiderin deposition were observed. No obvious demyelination was discovered, while gliosis, numerous Rosenthal fibers and fibrinoid vascular necrosis were found around the lesions. The clinical, neuroimaging and pathological features of this patient were in accordance with the cases reported in the literatures. CONCLUSIONS: Neuroimaging is the most important method for the diagnosis of LCC. As small vessel lesions are probably closely related to the pathophysiology of LCC, SWI could be recommended to further reveal the etiology of LCC.

CT two-dimensional reformation versus three-dimensional volume rendering with regard to surgical findings in the preoperative assessment of the ossicular chain in chronic suppurative otitis media.

PURPOSE: To assess the role of three-dimensional volume rendering (3DVR) in the preoperative assessment of the ossicular chain in chronic suppurative otitis media (CSOM). MATERIALS AND METHODS: Sixty-six patients with CSOM were included in this prospective study. Temporal bone was scanned with a 128-channel multidetector row CT and the axial data was transferred to the workstation for multiplanar reformation (MPR) and 3DVR reconstructions. Evaluation of the ossicular chain according to a three-point scoring system on two-dimensional reformation (2D) and 3DVR was performed independently by two radiologists. The evaluation results were compared with surgical findings. RESULTS: 2D showed over 89% accuracy in the assessment of segmental absence of the ossicular chain in CSOM, no matter how small the segmental size was. 3DVR was as accurate as 2D for the assessment of segmental absence. However, 3DVR was found to be more accurate than 2D in the evaluation of partial erosion of segments. CONCLUSION: Both 3DVR and 2D are accurate and reliable for the assessment of the ossicular chain in CSOM. The inclusion of 3DVR images in the imaging protocol improves the accuracy of 2D in detecting ossicular erosion from CSOM.

[Magnetic resonance spectroscopy-guided stereotactic biopsy for brain lesion].

OBJECTIVE: To study the clinical value of magnetic resonance spectroscopy (MRS) image in stereotactic biopsy for brain lesion. METHODS: From April 2008 to April 2010, 126 cases (72 male and 54 female, aged from 10 to 82 years, mean 45 years) of brain lesion which were difficult to diagnose were divided into two groups by random number table, 62 cases were executed for MRI-guided frameless stereotactic biopsy (MRI group), 64 cases were executed for MRI and MRS-guided frameless stereotactic biopsy (MRS group). Operation used MRI and Three-dimensional MRS image to locate, and used frameless CAS-R-2 robots to carry out the positioning operating. RESULTS: No surgery-related deaths and infections. Pathological diagnosis was 106 cases of brain tumors, 6 cases of inflammatory disease, 4 cases of tumor-like demyelinating disease and multiple sclerosis, 3 cases of neurodegenerative disease, 7 cases failed to obtain positive pathological diagnosis. The total rate of positive diagnosis was 94.4%, the positive rate in MRS-guided stereotactic biopsy group was 98.4% (63/64), the positive rate of conventional MRI-guided biopsy group was 90.3% (56/62), and there was statistically significant difference between the two groups (χ(2) = 3.92, P = 0.047). Four cases presented with postoperative complications, the complication rate was 3.2% (4/126); the complications were cerebral hemorrhage associated with aphasia, epilepsy, subcutaneous hematoma, gastrointestinal bleeding, which were improved after treatment. CONCLUSIONS: MRS-guided stereotactic biopsy group has a higher positive rate than MRI-guided stereotactic biopsy group, indicating that this method can improve the positive rate of diagnosis, and thus will help to formulate treatment plan for brain lesion.

[Clinical features and neuroimaging findings of 12 patients with acute disseminated encephalomyelitis involved in corpus callosum].

OBJECTIVE: To summarize the clinical features and neuroimaging findings of the patients with acute disseminated encephalomyelitis (ADEM) involved in corpus callosum (CC) so as to distinguish it from other diseases. METHODS: A total of 12 ADEM patients with the involvement of CC during the period of 2010-2012 were recruited. There were 9 males and 3 females with a mean age of 31±14 years (range: 10-54). Their clinical and neuroimaging features were retrospectively reviewed and all data analyzed by SPSS 18.0. RESULTS: (1) All of them had an acute or subacute onset. Two patients had a history of vaccination and 5 suffered upper respiratory tract infection or diarrhea. (2) The presenting symptoms included fever (n=5), headache (n=4), unsteady gait (n=2), urinary retention (n=1), indifference (n=1) and delirium (n=1). (3) The main clinical symptoms included memory loss (n=9), delirium (n=5), somnolence (n=4), urinary retention (n=9), paraplegia (n=4) and unsteady gait (n=5). (4) The examinations of cerebrospinal fluid (CSF) revealed increased intracranial pressure (n=4), leucocytosis (n=3) and increased protein (n=7) of 7 cases. All oligoclonal bands were negative. (5) The lesions were involved in bilateral CCs in 12 patients. Among them, splenium was the most commonly affected (n=9), secondly stem (n=5) and lastly genu (n=4). For 6 patients, the intracranial lesions were all in their CCs. And among them, 2 cases were involved in spinal cord. Except for CC, there were other focal lesions in brain stem and cerebellum (n=4) and spinal cord (n=6). (6) On magnetic resonance imaging (MRI), all cases showed long T2 signal intensity with blurred images. And among them, 2 cases' lesions in brain were discerned only by diffuse weighing imaging (DWI) or T2 fast fluid-attenuated inversion recovery (T2FLAIR) instead of T2-weighted. The lesions of CCs showed on gadolinium-enhanced MRI were significantly enhanced and the shapes were sheet-like (4/6). Spinal cord lesions was found in 6 cases and most spinal cord lesions were discontinuous. And the number of spinal cord segments with lesions was from 4 to 8. The shapes of lesions of spinal cord showed on enhanced MRI were like thin line. (7) Most of them were misdiagnosed as viral encephalitis (n=5), tuberculous meningoencephalitis (n=1) and brain neoplasms (n=2). And another case was admitted into urology surgery ward due to urinary retention. CONCLUSION: There are three key points about the characteristics of the ADEM patients with CC lesions: (1) They may have an adult male preponderance. The distinctive symptoms include fever, headache, delirium, somnolence, memory loss, unsteady gait and urination disorders, etc.. (2) The number of lesions on brain MRI can be multiple or single, especially the lesions of CC (mostly in splenium). On MRI, all cases showed long T2 signal intensity with blurred images so that DWI and T2 FLAIR may have a higher efficiency of detecting the lesions. In particular, multiple lesions may be all enhanced or not enhanced at equal pace on enhanced MRI. (3) In ADEM patients with CC lesions, many indices of CSF chemical examination, such as increased intracranial pressure, leucocytosis, increased protein, low sugar and low chloride, indicate the presence of intracranial infective diseases. Therefore they are most likely to be misdiagnosed as viral encephalitis or tuberculous meningoencephalitis. However, CC is not the predilection site for viral encephalitis since CC belongs to white matter but not gray matter. So ADEM should be a more appropriate diagnosis for these cases.

[A multi-phase flow detector system based on gamma-ray].

In the present paper, a gamma-ray based on-line detection system was designed for multi-phase flow measurement, where the complicated fluid property of multi-phase flow can be studied by using the principle of ray transmission. The system is made up of three parts, i. e., the sensing unit, the signal conditioning & processing unit and the computer imaging unit. The sensing unit consists of five 241 Am sources with principal energy of 59.5 keV and five sets of CdZnTe semiconductor detectors by using the Geant 4 simulating software toolkits. The sources and detectors are mounted equally at the cross section of pipeline to detect different phase medium simultaneously. This function of the system guarantees the real-time performance of the on-line detecting. In order to improve the accuracy of the probe, a low noise probe circuit was designed, including a low noise charge-sensitive preamplifier, a low noise amplifier, filter circuit and an eliminated zero-poles circuit. Some of the emitted gamma-ray photons from the radiation sources are detected by the sensing element, where the photo energy is transferred into electrical energy by using CdZnTe semiconductor detectors. The output of the sensing element is sent to the signal conditioning & processing unit, which is amplified and filtered to be a level-discriminated signal. Finally, the output of the signal conditioning & processing unit is sent to the computer imaging unit, in which the 2D images are reconstructed by using a certain reconstruction algorithm. Under the normal temperature, the system performs the test of energy spectrum and then it has better energy resolution about 4.38% for 241 Am 59.5 keV. The result reveals that our system has higher probe accuracy. Using experimental data, the images are reconstructed with Filter back projection (FBP) reconstruction algorithm. Images of high quality are achieved.

Gene cloning, expression, and characterization of a thermostable xylanase from Nesterenkonia xinjiangensis CCTCC AA001025.

An endo-beta-1,4-xylanase-encoding gene, xyn11NX, was cloned from Nesterenkonia xinjiangensis CCTCC AA001025 and expressed in Escherichia coli. The gene encoded a 192-amino acid polypeptide and a putative 50-amino acid signal peptide. The deduced amino acid sequence exhibited a high degree of similarity with the xylanases from Streptomyces thermocyaneoviolaceus (68%) and Thermobifida fusca (66%) belonging to glycoside hydrolase family 11. After purification to homogeneity, the recombinant Xyn11NX exhibited optimal activity at pH 7.0 and 55 degrees C and remained stable at weakly acidic to alkaline pH (pH 5.0-11.0). The enzyme was thermostable, retaining more than 80% of the initial activity after incubation at 60 degrees C for 1 h and more than 40% of the activity at 90 degrees C for 15 min. The K (m) and V (max) values for oat spelt xylan and birchwood xylan were 16.08 mg ml(-1) and 45.66 micromol min(-1) mg(-1) and 9.22 mg ml(-1) and 16.05 micromol min(-1) mg(-1), respectively. The predominant hydrolysis products were xylobiose and xylotriose when using oat spelt xylan or birchwood xylan as substrate.

Identification and characterization of two bamboo (Phyllostachys praecox) AP1/SQUA-like MADS-box genes during floral transition.

Bamboo (Bambusoideae) is by far the largest member of the grass family Poaceae, which is vital to the economy of many countries in the tropics and subtropics. However, the mechanism of flowering of bamboo (Phyllostachys praecox) is still unknown. In this study, we isolated two novel genes from P. praecox and evaluated their functional characteristics. The sequence and phylogenetic analysis indicated that these two genes, named PpMADS1 and PpMADS2, belong to FUL3 and FUL1 clade of Poaceae AP1/SQUA-like genes, respectively. The PpMADS2 possesses a truncated C terminus lacking the highly conserved paleoAP1 motif. It was further confirmed that the truncated C-terminal region was produced by natural sequence deletion in exons, but not by alternative splicing. Ectopic expression of PpMADS1 and PpMADS2 significantly promoted early flowering through upregulation of AP1 in Arabidopsis. Yeast two-hybrid experiments demonstrated that AP1 protein can interact with PpMADS1 but not PpMADS2, suggesting that these two genes may act differently in signaling early flowering of bamboo plants. RT-qPCR and in situ hybridization analysis revealed distinct expression patterns of these two genes in vegetative and reproductive tissues of bamboo. Taken together, our results suggest that both PpMADS1 and PpMADS2 are involved in floral transition, and PpMADS2 might play more important roles than PpMADS1 in floral development of Phyllostachys praecox.

Polyketides from a marine sponge-derived fungus Mycelia sterilia and proton-proton long-range coupling.

A series of polyketide-originated metabolites (1-5) were isolated from a marine sponge-derived fungus Mycelia sterilia. Of these, 1-3 were new compounds. Their structures were elucidated by spectroscopic methods as (4R*, 5S*, 6S*, 8S*, 13R*)-1-(2,8-dihydroxy-1,2,6-trimethyl-1,2,6,7,8,8a-hexahydro-naphthalen-1-yl)-3-methoxy-propan-1-one (1), 4,8-dihydroxy-7-(2-hydroxy-ethyl)-6-methoxy-3,4-dihydro-2H-naphthalen-1-one (2) and 1-methyl-naphthalene-2,6-dicarboxylic acid (3). In 1, the proton-proton long-range coupling phenomenon claimed attention and was discussed.

Lidocaine-induced Brugada syndrome phenotype linked to a novel double mutation in the cardiac sodium channel.

Brugada syndrome has been linked to mutations in SCN5A. Agents that dissociate slowly from the sodium channel such as flecainide and ajmaline unmask the Brugada syndrome electrocardiogram and precipitate ventricular tachycardia/fibrillation. Lidocaine, an agent with rapid dissociation kinetics, has previously been shown to exert no effect in patients with Brugada syndrome. We characterized a novel double mutation of SCN5A (V232I in DI-S4+L1308F in DIII-S4) identified in a rare case of lidocaine (1 mg/kg)-induced Brugada syndrome. We studied lidocaine blockade of I(Na) generated by wild-type and V232I+L1308F mutant cardiac sodium channels expressed in mammalian TSA201 cells using patch clamp techniques. Despite no significant difference in steady-state gating parameters between V232I+L1308F and wild-type sodium currents at baseline, use-dependent inhibition of I(Na) by lidocaine was more pronounced in V232I+L1308F versus wild-type (73.0+/-0.1% versus 18.23+/-0.04% at 10 micromol/L measured at 10 Hz, respectively). A dose of 10 micromol/L lidocaine also caused a more negative shift of steady-state inactivation in V232I+L1308F versus wild-type (-14.1+/-0.3 mV and -4.8+/-0.3 mV, respectively). The individual mutations produced a much less accentuated effect. We report the first case of lidocaine-induced Brugada electrocardiogram phenotype. The double mutation in SCN5A, V232I, and L1308F alters the affinity of the cardiac sodium channel for lidocaine such that the drug assumes Class IC characteristics with potent use-dependent block of the sodium channel. Our results demonstrate an additive effect of the 2 missense mutations to sensitize the sodium channel to lidocaine. These findings suggest caution when treating patients carrying such genetic variations with Class I antiarrhythmic drugs.

[Value of multiplanar reconstruction of lumbar nerve roots on the same level by high resolution computed tomography in diagnosis of lumbar disc herniation and/or bulge].

OBJECTIVE: To explore value of multiplanar reconstruction of lumbar nerve roots on the same level by high resolution computed tomography (HRCT) in diagnosis of lumbar disc herniation and/or bulge (LDHB). METHODS: Thirty-one patients with manifestations of typical nerve root compression, such as lumbago and tenderness of percussion pain at the corresponding sites were scanned with 16-slice spiral CT and multiplanar reconstruction of lumbar nerve roots on the same level with the workshop ADW4.150, and were diagnosed as with LDHB with 50 segments. The diagnoses were confirmed by operation later. RESULTS: This technique showed not only the existence of LDHB but also the signs of nerve root compression, including the touch of nerve roots with the LDHB (100%), translocation of nerve roots (96%), morphological change (94%), changes of diameter (92%), changes of direction (88%), changes of density (80%), increase of the angle between the dural sac and nerve root (76%), etc. Along with the prolonging of time, the nerve roots became thinner in all segments. CONCLUSION: Multiplanar reconstruction of lumbar nerve roots on the same level by high resolution computed tomography is valuable in the diagnosis of lumbar disc herniation and/or bulge.