A genetic module at one locus in rice protects chloroplasts to enhance thermotolerance

How the plasma membrane senses external heat-stress signals to communicate with chloroplasts to orchestrate thermotolerance remains elusive. We identified a quantitative trait locus, Thermo-tolerance 3 (TT3), consisting of two genes, TT3.1 and TT3.2, that interact together to enhance rice thermotolerance and reduce grain-yield losses caused by heat stress. Upon heat stress, plasma membrane-localized E3 ligase TT3.1 translocates to the endosomes, on which TT3.1 ubiquitinates chloroplast precursor protein TT3.2 for vacuolar degradation, implying that TT3.1 might serve as a potential thermosensor. Lesser accumulated, mature TT3.2 proteins in chloroplasts are essential for protecting thylakoids from heat stress. Our findings not only reveal a TT3.1-TT3.2 genetic module at one locus that transduces heat signals from plasma membrane to chloroplasts but also provide the strategy for breeding highly thermotolerant crops.

Multi-channel electrochemiluminescence of luminol at a copper electrode

Multi-channel electrochemiluminescence (ECL) of luminol at a copper electrode has been studied under conventional cyclic voltammetric (CV) conditions. Compared with the ECL of luminol at other electrodes, three ECL peaks were observed at 0.30, -0.24 and -0.65 V (vs. SCE), respectively, which was also imaged by a CCD camera. The effects of potential scan direction, anodic reverse potential, the presence of N2 and O2 of the solution, the pH of the solution, the NaNO3 concentration and the potential scan rate were examined. The effect of n-alkanethiol self-assembled monolayers on copper electrodes and 20 L-amino acids, dopamine, adrenaline and noradrenaline on the ECL of luminol were also investigated. The emission spectra of various ECL peaks at different potentials demonstrated that all ECL peaks were related to the luminol reaction. The results show that the oxygen dissolved in solution and copper oxide covered on the surface of the electrode play an important role in the luminol ECL process at a copper electrode. It has been proposed that three ECL channels of luminol at a copper electrode resulted from the reactions of luminol or luminol radical electrooxidized by luminol with various electrogenerated oxygen-containing species, such as O2, OOH- and copper oxides at different potentials.

Exploring the binding features of polybrominated diphenyl ethers as estrogen receptor antagonists: docking studies

The polybrominated diphenyl ethers (PBDEs) accumulating in nature are known to be endocrine-disrupting compounds. Of first concern are those interacting with and altering activity of the human estrogen receptor alpha (hERalpha). In this study a docking study was carried out to explore the binding modes of PBDE compounds as hERalpha antagonists. It was found that some of the PBDE compounds with antiestrogenic activity extended into the channel of the estrogen receptor (ER), which is usually occupied by the alkylamine side chain of the ER antagonists raloxifene (RAL) and 4-hydroxytamoxifen (OHT), while most PBDE compounds without antiestrogenic activity adopted binding modes similar to that of ER agonist 17beta-estradiol (E2), located in the binding cavity and which did not protrude into the channel. The present study suggests that pose comparison based on docking is useful for discriminating whether or not PBDE compounds have antiestrogenic activity. Knowing the binding modes of compounds in hERalpha can help to screen out antiestrogenic compounds and further develop descriptive and predictive models in ecotoxicology.

Cathodic electrochemiluminescence of acetonitrile, acetonitrile–1,10-phenanthroline and acetonitrile–ternary Eu(III) complexes at a gold electrode

Cathodic electrochemiluminescence (ECL) behaviours of the acetonitrile, acetonitrile-1,10-phenanthroline (phen) and acetonitrile-ternary Eu(III) complex systems at a gold electrode were studied. One very weak cathodic ECL-2 at -3.5 V was observed in 0.1 mol/L tetrabutylammonium tetrafluoroborate (TBABF(4)) acetonitrile solution. When 10 mmol/L tetrabutylammonium peroxydisulphate [(TBA)(2)S(2)O(8)] was added to 0.1 mol/L TBABF(4) acetonitrile solution, another cathodic ECL-1 at -2.7 V appeared and the potential for ECL-2 was shifted from -3.5 to -3.1 V. Furthermore, ECL-2 intensity was enhanced about 20-fold. When 1 x 10(-4) mol/L phen was added to 0.1 mol/L TBABF(4) + 10 mmol/L (TBA)(2)S(2)O(8) acetonitrile solution, the ECL intensities of ECL-1 and ECL-2 were enhanced about 20-fold compared with those of 0.1 mol/L TBABF(4) + 10 mmol/L (TBA)(2)S(2)O(8) acetonitrile solution. The maximum emission peaks of ECL-1 and ECL-2 in the three systems mentioned above appeared at about 530 nm. The products obtained by electrolysing 0.1 mol/L TBABF(4) acetonitrile solution at -3.5 V for 20 min were analysed by Fourier Transform Infrared (FTIR) spectra and gas chromatography-mass spectrometry (GC-MS) and the emitter of ECL-1 and ECL-2 was identified as excited state polyacetonitrile. When ternary Eu(III) complexes were presented in 0.1 mol/L TBABF(4) + 10 mmol/L (TBA)(2)S(2)O(8) acetonitrile solution, another maximum emission peak with a narrow band centred at about 610 nm appeared in ECL-1 in addition to the maximum emission peaks at about 530 nm for ECL-1 and ECL-2. The emitter of ECL emission at 610 nm was identified as the excited states Eu(III)*. The mechanisms for cathodic ECL behaviours of the acetonitrile, acetonitrile-phen and acetonitrile-ternary Eu(III) complex systems at a gold electrode have been proposed. The extremely sharp emission bands for ternary Eu(III) complexes may have analytical potential.

Optimization of rice panicle architecture by specifically suppressing ligand-receptor pairs

Rice panicle architecture determines the grain number per panicle and therefore impacts grain yield. The OsER1-OsMKKK10-OsMKK4-OsMPK6 pathway shapes panicle architecture by regulating cytokinin metabolism. However, the specific upstream ligands perceived by the OsER1 receptor are unknown. Here, we report that the EPIDERMAL PATTERNING FACTOR (EPF)/EPF-LIKE (EPFL) small secreted peptide family members OsEPFL6, OsEPFL7, OsEPFL8, and OsEPFL9 synergistically contribute to rice panicle morphogenesis by recognizing the OsER1 receptor and activating the mitogen-activated protein kinase cascade. Notably, OsEPFL6, OsEPFL7, OsEPFL8, and OsEPFL9 negatively regulate spikelet number per panicle, but OsEPFL8 also controls rice spikelet fertility. A osepfl6 osepfl7 osepfl9 triple mutant had significantly enhanced grain yield without affecting spikelet fertility, suggesting that specifically suppressing the OsEPFL6-OsER1, OsEPFL7-OsER1, and OsEPFL9-OsER1 ligand-receptor pairs can optimize rice panicle architecture. These findings provide a framework for fundamental understanding of the role of ligand-receptor signaling in rice panicle development and demonstrate a potential method to overcome the trade-off between spikelet number and fertility.

An α/β hydrolase family member negatively regulates salt tolerance but promotes flowering through three distinct functions in rice

Ongoing soil salinization drastically threatens crop growth, development, and yield worldwide. It is therefore crucial that we improve salt tolerance in rice by exploiting natural genetic variation. However, many salt-responsive genes confer undesirable phenotypes and therefore cannot be effectively applied to practical agricultural production. In this study, we identified a quantitative trait locus for salt tolerance from the African rice species Oryza glaberrima and named it as Salt Tolerance and Heading Date 1 (STH1). We found that STH1 regulates fatty acid metabolic homeostasis, probably by catalyzing the hydrolytic degradation of fatty acids, which contributes to salt tolerance. Meanwhile, we demonstrated that STH1 forms a protein complex with D3 and a vital regulatory factor in salt tolerance, OsHAL3, to regulate the protein abundance of OsHAL3 via the 26S proteasome pathway. Furthermore, we revealed that STH1 also serves as a co-activator with the floral integrator gene Heading date 1 to balance the expression of the florigen gene Heading date 3a under different circumstances, thus coordinating the regulation of salt tolerance and heading date. Notably, the allele of STH1 associated with enhanced salt tolerance and high yield is found in some African rice accessions but barely in Asian cultivars. Introgression of the STH1^HP46 allele from African rice into modern rice cultivars is a desirable approach for boosting grain yield under salt stress. Collectively, our discoveries not only provide conceptual advances on the mechanisms of salt tolerance and synergetic regulation between salt tolerance and flowering time but also offer potential strategies to overcome the challenges resulted from increasingly serious soil salinization that many crops are facing.

Development of SCAR Markers and an SYBR Green Assay to Detect Puccinia striiformis f. sp. tritici in Infected Wheat Leaves

Stripe rust, caused by the pathogenic fungus Puccinia striiformis f. sp. tritici, is an important disease of wheat worldwide. A rapid and reliable detection of the pathogen in latent infected wheat leaves is useful for accurate and early forecast of outbreaks and timely application of fungicides for managing the disease. Using the previously reported primer pair Bt2a/Bt2b, a 362-bp amplicon was obtained from P. striiformis f. sp. tritici and a 486-bp amplicon was obtained from both P. triticina (the leaf rust pathogen) and P. graminis f. sp. tritici (the stem rust pathogen). Based on the sequence of the 362-bp fragment, two pairs of sequence characterized amplified region (SCAR) primers were designed. PSTF117/PSTR363 produced a 274-bp amplicon and TF114/TR323 produced a 180-bp amplicon from P. striiformis f. sp. tritici, whereas they did not produce any amplicon from P. triticina, P. graminis f. sp. tritici, or any other wheat-infecting fungi. The detection limit of PSTF117/PSTR363 was 1 pg/µl and TF114/TR323 was 100 fg/µl. Both SCAR markers could be detected in wheat leaves 9 h post inoculation. An SYBR Green RT-PCR method was also developed to detect P. striiformis f. sp. tritici in infected leaves with the detection limit of 1.0 fg DNA from asymptomatic leaf samples of 6 h after inoculation. These methods should be useful for rapid diagnosis and accurate detection of P. striiformis f. sp. tritici in infected wheat leaves for timely control of the disease.

A11 Tetramer-assisted characterization of Rta-specific CD8+ T-cell responses in healthy virus carriers

HLA Class I-restricted CD8(+) T-cell responses are believed to play an important role in controlling Epstein-Barr virus (EBV) infection, which has been consistently associated with nasopharyngeal carcinoma (NPC). Immediate early transactivator Rta of EBV has been shown to be associated with the reactivation of EBV from latency and drive the lytic cascade of EBV and comprise an important target for EBV-specific cellular cytotoxicity. Furthermore, BRLF1 is specifically expressed in NPC tumor cells. The protein product of BRLF1, Rta, could then be considered as a NPC tumor antigen. Therefore, cellular immunity against Rta represents a very important part of the immunity against NPC, as they should prevent the replication of EBV. In the present study, Rta-specific CD8(+) T-cell responses in healthy virus carriers were characterized by using A1101 tetramer containing the known Rta epitope ATIGTAMYK (134-142). We clearly showed A1101/ATIGTAMYK tetramer-reactive CD8(+) T cells in the circulation of healthy virus carriers, ranging from 2.13 to 9.03%. We then studied the expression of perforin and interferon-gamma (IFN-gamma) secretion in these Rta-specific T cells. Our study demonstrated that Rta-specific T cells are capable of IFN-gamma production and nearly 90% of the Rta-specific CD8(+) T cells expressed perforin. Presumably, these are the cells that play an important role in determining the initiation of the lytic cycle or the clearance of EBV.

Three-dimensional quantitative structure activity relationship (3D-QSAR) analysis for in vitro toxicity of chlorophenols to HepG2 cells

In the present paper, comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were applied to investigate two 3D-QSAR models for the cytotoxicity of chlorophenols. These models have evaluated the intensity of chlorophenols' toxicity on HepG2 cells in vitro. The CoMFA model has both high consistency and predictability. The contribution of the electrostatic field to biological activity is greater than that of the steric field. The CoMSIA model used in this study includes two fields, one is hydrophobic field, and the other is electrostatic field. The relative contribution of them is 0.789:0.211. Consisted with the CoMFA model, the CoMSIA electrostatic filed also plays a dominant role. The CoMFA and CoMSIA contour maps significantly elucidated that the electrostatic field is more important than the other fields and might be one of the reasons resulting in potential reactive mechanism involved in cell proliferation inhibition.

HLA microsatellite associations with insulin-dependent diabetes mellitus in Singaporean Chinese

Singaporean Chinese with insulin-dependent diabetes mellitus (IDDM) have previously been shown to be associated with the DRB1*0301 haplotype and the joint occurrence of DRB1*0301/*0901 and DRB1*0301/*04. The present study extended previous HLA associations by investigating the HLA region using four microsatellites (TNFa, D6S273, TAP1, DQCARII). Seventy-five IDDM patients and 80 healthy controls were studied. TNFa*3 (RR = 2.26), TNFa*12 (RR = 3.30), TAP1*9 (RR = 2.55) showed increased frequencies while TNFa*11 (RR = 0.29), TAP1*4 (RR = 0.50) showed decreased frequencies in patients compared to controls. Linkage analysis suggested that the positive associations of TNFa*3 and TAP1*9 were secondary to that of DRB1*0301. However, TNFa*12 appeared to provide additional risks to IDDM besides the DRB1*0301 haplotype, whereas TNFa*11 and TAP1*4 conferred an independent protective effect against IDDM. Our findings reinforce the notion that susceptibility to and protection against IDDM may include TNF region. In the present study, TNFa*12 seemed to be the primary association in the DRB1*0405 haplotype and may play an independent role in the pathogenesis of IDDM through TNF-alpha function.

HLA microsatellite associations with insulin-dependent diabetes mellitus in Singaporean Chinese

Singaporean Chinese with insulin-dependent diabetes mellitus (IDDM) have previously been shown to be associated with the DRB1*0301 haplotype and the joint occurrence of DRB1*0301/*0901 and DRB1*0301/*04. The present study extended previous HLA associations by investigating the HLA region using four microsatellites (TNFa, D6S273, TAP1, DQCARII). Seventy-five IDDM patients and 80 healthy controls were studied. TNFa*3 (RR = 2.26), TNFa*12 (RR = 3.30), TAP1*9 (RR = 2.55) showed increased frequencies while TNFa*11 (RR = 0.29), TAP1*4 (RR = 0.50) showed decreased frequencies in patients compared to controls. Linkage analysis suggested that the positive associations of TNFa*3 and TAP1*9 were secondary to that of DRB1*0301. However, TNFa*12 appeared to provide additional risks to IDDM besides the DRB1*0301 haplotype, whereas TNFa*11 and TAP1*4 conferred an independent protective effect against IDDM. Our findings reinforce the notion that susceptibility to and protection against IDDM may include TNF region. In the present study, TNFa*12 seemed to be the primary association in the DRB1*0405 haplotype and may play an independent role in the pathogenesis of IDDM through TNF-alpha function.

Cytological identification of an isotetrasomic in rice and its application to centromere mapping

The aneuploid with isochromosome or telochromosome is ideal material for exploring the position of centromere in lingkage map. For obtaining these aneuploids in rice, the primary trisomics from triplo-1 to triplo-12 and the aneuploids derived from a triploid of indica rice variety Zhongxian 3037 were carefully investigated. From the offsprings of triplo-10, a primary trisomic of chromosome 10 of the variety, an isotetrasomic "triplo-10-1" was obtained. Cytological investigation revealed that a pair of extra isochromosomes of triplo-10-1 were come from the short arm of chromosome 10. In the offsprings of the isotetrasomic, a secondary trisomic "triplo-10-2", in which the extra- chromosome was an isochromosome derived from the short arm of chromosome 10, was identified. With the isotetrasomic, secondary trisomic, primary trisomic and diploid of variety Zhongxian 3037, different molecular markers were used for exploring the position of the centromere of chromosome 10. Based on the DNA dosage effect, it was verified that the molecular markers G1125, G333 and L169 were located on the short arm, G1084 and other 16 available molecular markers were on the long arm of chromosome 10. So the centromere of chromosome 10 was located somewhere between G1125 and G1084 according to the RFLP linkage map given by Kurata et al[1]. The distance from G1125 to G1084 was about 3.2 cM.

Associations of HLA microsatellites with rheumatoid arthritis in Singaporean Chinese

Rheumatoid arthritis in Singaporean Chinese has previously been shown to be associated with the DRB1*0405, DRB1*1001 haplotypes and to the DRB1*0901 haplotype when the former two were removed. The present paper focused on eight HLA associated microsatellite markers (TNFa, TNFd, D6S273, TAP1CA, DQCAR, DQCARII, D6S2222, D6S2223) and their allelic associations with Chinese RA. 60 RA patients and 75 healthy controls were studied. It appeared that DQCARII*194/DRB1*0405/TNFa*117 was part of the extended haplotype predisposed to RA, whereas DRB1*0901/D6S273*128 contributed to susceptibility to RA to a lesser degree in Singaporean Chinese. Additionally, a negative association with DQCAR*186/DRB1*0301/D6S273*122/TNFd*124 was observed. No association with disease development was observed in this study.

[The fMRI research of vestibular migraine neural pathways]

Objective:To investigate the abnormal functional response of neural pathways of vestibular migraine (VM) patients, located the functional area, and inferred the possible mechanism. Method:Twenty patients of VM, 20 of migraine without aura (MwoA), and 20 of healthy controls (HC), underwent whole-brain blood oxygen level-dependent (BOLD) fMRI during ear irrigation with cold water. We chose the stimulation image and the diapause stimulation image. Analyses explored functional area with BOLD signal change of the three groups. Result:We observed task-positive BOLD signal change in cortical and subcortical pattern in response to ear irrigation of all participants. Such as parietal lobe, temporal lobe, insular lobe, cingulate gyrus, thalamus, caudate nucleus, optic radiation, precuneus. VM patients showed a significantly task-negative in thalamic and fusiform gyrus in comparison with the other groups (P<0.05). Conclusion:fMRI could response the respective functional area objectively. We inferred the possible mechanism of VM was abnormal activation of thalamus and fusiform gyrus, produced crossing between the vestibular sensory pathway conduction and the pain conduction.

Development of quantitative structure activity relationships in toxicity prediction of complex mixtures

AIM

To predict the toxicity of mixtures of halogenated benzenes (narcotics).

METHODS

Acute toxicity test of single chemicals and mixtures was performed using Photobacterium phosphoreum. Partition coefficients of mixtures were calculated by a special equation. Quantitative structure-activity relationship (QSAR) studies were carried out based on results of toxicity tests, n-octanol/water partition coefficient (Kow), and partition coefficient of mixtures (Kmix).

RESULTS

1) There was a good relationship between toxicity and lgKow for single compounds. 2) QSAR analysis showed a perfect correlation between the calculated Kmix and the mixture toxicity for binary mixtures. 3) Using the QSAR model of binary mixtures, the toxicity of other related mixtures containing different composition and fraction was predicted very well.

CONCLUSION

The toxicity of halogenated benzene mixtures (narcotics) was predicted by QSAR. This kind of study is helpful for assessing the toxicity of narcotic mixtures.

Functional studies in the human submandibular duct cell line, HSG-PA, suggest a second salivary gland receptor subtype for nucleotides

Extracellular nucleotides, acting through P2 purinoceptors, have been implicated in the regulation of ion transporting epithelia, including salivary gland acini. Multiple P2 purinoceptor subtypes have been suggested, including P2X, P2Y and P2U (or nucleotide) subtypes, as well as the P2Z subtype found in rat parotid acinar cells. We investigated responses to ATP, ATP analogs and UTP in transformed human submandibular gland duct cells (HSG-PA), in order to compare duct cell purinoreceptors with those in acinar cells. ATP, UTP and some ATP analogs increased, with different potencies, inositol phosphate accumulation, calcium mobilization and potassium efflux. Nucleotide-stimulated calcium mobilization occurred in the absence of, but was enhanced by, extracellular calcium, and maximal potassium efflux required extracellular calcium. UTP and ATP demonstrated equal potencies of about 1 microM and similar efficacies in eliciting these responses, and identical rank orders of potency for stimulating calcium mobilization and potassium efflux were obtained: UTP = ATP greater than ATP gamma S greater than ADP greater than ADP beta S, with alpha,beta-methylene-ATP and 2-methylthio-ATP having little or no effect. Agents reported to block nucleotide effects in parotid acini were ineffective in HSG-PA cells, and experiments in Mg(++)- and Ca(++)-free medium did not indicate that a form of ATP other than MgATP was the active species at the HSG-PA purinoceptor. The extracellular nucleotide effects were not altered by pertussis toxin. These results indicate the presence of a P2U or nucleotide receptor subtype in HSG-PA submandibular duct cells distinguishable from the P2Z purinoceptor of rat parotid acinar cells, suggesting involvement of multiple nucleotide receptor subtypes in salivary gland regulation.

A TT1-SCE1 module integrates ubiquitination and SUMOylation to regulate heat tolerance in rice

Heat stress poses a significant threat to grain yield. As an α2 subunit of the 26S proteasome, TT1 has been shown to act as a critical regulator of rice heat tolerance. However, the heat tolerance mechanisms mediated by TT1 remain elusive. In this study, we unveiled that small ubiquitin-like modifier (SUMO)-conjugating enzyme 1 (SCE1), which interacts with TT1 and acts as a downstream component of TT1, is engaged in TT1-mediated 26S proteasome degradation. We showed that SCE1 functions as a negative regulator of heat tolerance in rice, which is associated with its ubiquitination modification. Furthermore, we observed that small heat-shock proteins (sHSPs) such as Hsp24.1 and Hsp40 can undergo SUMOylation mediated by SCE1, leading to increased accumulation of sHSPs in the absence of SCE1. Reducing protein levels of SCE1 significantly enhanced grain yield under high-temperature stress by improving seed-setting rate and rice grain filling capacity. Taken together, these results uncover the critical role of SCE1 in the TT1-mediated heat tolerance pathway by regulating the abundance of sHSPs and SUMOylation, and ultimately modulating rice heat tolerance. These findings underscore the great potential of the TT1-SCE1 module in improving the heat tolerance of crops.

Fine-tuning gibberellin improves rice alkali-thermal tolerance and yield

Soil alkalinization and global warming are predicted to pose major challenges to agriculture in the future, as they continue to accelerate, markedly reducing global arable land and crop yields1,2. Therefore, strategies for future agriculture are needed to further improve globally cultivated, relatively high-yielding Green Revolution varieties (GRVs) derived from the SEMIDWARF 1 (SD1) gene3,4. Here we propose that precise regulation of the phytohormone gibberellin (GA) to optimal levels is the key to not only confer alkali-thermal tolerance to GRVs, but also to further enhance their yield. Endogenous modulation of ALKALI-THERMAL TOLERANCE 1/2 (ATT1/2), quantitative trait loci encoding GA20-oxidases or exogenous application of GA minimized rice yield loss affected by sodic soils. Mechanistically, high GA concentrations induce reactive oxygen species over-accumulation, whereas low GA concentrations repress the expression of stress-tolerance genes by means of DELLA-NGR5-mediated H3K27me3 methylation. We further showed that ATT1 induces large fluctuations in GA levels, whereas ATT2 is the ideal candidate for fine-tuning GA concentrations to appropriate levels to balance reactive oxygen species and H3K27me3 methylation to improve alkali-thermal tolerance and yield. Thus, ATT2 is expected to be a potential new post-Green Revolution gene that could be harnessed to develop and use marginal lands for sustainable agriculture in the future.

[Isolation and cytological identification of a desynaptic variant in rice]

A sterile variant was found from the population of a japonica rice variety Lunhui 422. Cytological investigation was conducted in meiosis. It is showed that the sterility was caused by desynapsis. As there were 8.69 bivalents in average occurred to be desynaptic, moreover, the most number of the desynaptic bivalents reached 12 at post diakinsis. It can be considered that the desynaptic variation is a complete desynapsis found in rice so far.

[Effect analysis on endoscopic transnasal resection of epidural cholesteatoma at paracentral skull base]

Objective: To indicate the clinical features of endoscopic transnasal resection of epidural cholesteatoma at paracentral skull base and to analyze its efficacy. Methods: The total excision rate, postoperative complications and postoperative curative effect of 7 patients (4 males and 3 females, aging from 32 to 63 years old) who underwent middle skull base surgery for epidural cholesteatoma resection under transnasal endoscope at Tianjin Huanhu Hospital between August 2017 and August 2020 were retrospectively reviewed. All patients were followed up for 6 to 36 months. The postoperative MRI, clinical symptoms and recurrence were reviewed. Descriptive statistical methods were used for analysis. Results: Among the 7 patients, there were total resection (complete resection of cyst contents and capsule) in 4 patients, near-total resection (complete resection of cyst contents, incomplete resection of cyst capsule) in 1 patient, and subtotal resection (incomplete resection of cyst contents and capsule) in 2 patients. The clinical symptoms of all patients were improved postoperatively with 1 patient who had no clinical symptoms. One case had postoperative cerebrospinal fluid rhinorrhea, which was cured after lumbar drainage and nasal iodoform gauge packing. Up to now, 7 patients (including patients with partial resection) had no recurrence. Conclusion: Endoscopic transnasal approaches may be effectively used for resection of epidural cholesteatoma in the paracentral skull base in carefully selected cases.

The protective effect of puerarin against myocardial reperfusion injury. Study on cardiac function

In order to find out if puerarin could protect the hearts from myocardial reperfusion injury after cardiac arrest, twelve dogs divided into two equal groups were placed on moderately hypothermic cardiopulmonary bypass and their hearts were subjected to 140 min of cold cardioplegic arrest and 60 min of reperfusion. In the control group, the hearts were perfused with a crystalloid cardioplegic solution (CPS) through the aortic root every 20 min during arrest. In the treated group, the hearts received CPS containing puerarin (2 mg/kg). Cardiac hemodynamic variables were monitored throughout the experiments. Left ventricular function curves were formed before ischemia and after 60 min of reperfusion. The results showed that the recovery of left ventricular function in the treated group was significantly better than that in the controls (81 +/- 11% versus 39 +/- 7%, P less than 0.01). Compared with preischemic values, the increase of coronary blood flow (CBF) at cardiac arrest in the puerarin-treated group was higher than that in the control group (214 +/- 11 versus 177 +/- 4 ml/min, P less than 0.01). The data indicate that puerarin has protective effects on the cardiac function after prolonged arrest and reperfusion.

[Clinical analysis of brain abscess after endoscopic repairment of cerebrospinal fluid rhinorrhea]

Objective: To explore the clinical characteristics of the complication of brain abscesses after cerebrospinal fluid rhinorrhea repairment. Methods: A retrospective analysis was conducted on 149 patients undergone endoscopic repairment of cerebrospinal fluid rhinorrhea from October 2007 to October 2017 in Department of Otorhinolaryngology Head and Neck Surgery, Tianjin HuanHu Hospital. The clinical characteristics and treating methods of 3 brain abscess cases were analyzed. Results: Of the 149 patients accepted the endoscopic repairment of cerebrospinal fluid rhinorrhea, 3 cases were complicated with postoperative brain abscesses, which showed as frontal lobe abscess by strengthened head MRI. The incidence of abscess was 2.0%. Abscess formation time was within 10 d after surgery. One case was treated with antibiotic and reducing intracranial pressure, while other 2 cases were treated with puncture drainage. After following-up of 1 to 24 months, these 3 cases had no recurrence of cerebrospinal fluid rhinorrhea or abscess. Conclusions: The complication of brain abscess formation after endoscopic repairment of cerebrospinal fluid rhinorrhea is more common in frontal lobe, which may take place within 7-10 d postoperatively. Conservative treatment is the first choice. Under the condition of obvious symptoms and pus cavity fusion, puncture drainage can be performed.

Dysfunction of duplicated pair rice histone acetyltransferases causes segregation distortion and an interspecific reproductive barrier

Postzygotic reproductive isolation, which results in the irreversible divergence of species, is commonly accompanied by hybrid sterility, necrosis/weakness, or lethality in the F1 or other offspring generations. Here we show that the loss of function of HWS1 and HWS2, a couple of duplicated paralogs, together confer complete interspecific incompatibility between Asian and African rice. Both of these non-Mendelian determinants encode the putative Esa1-associated factor 6 (EAF6) protein, which functions as a characteristic subunit of the histone H4 acetyltransferase complex regulating transcriptional activation via genome-wide histone modification. The proliferating tapetum and inappropriate polar nuclei arrangement cause defective pollen and seeds in F2 hybrid offspring due to the recombinant HWS1/2-mediated misregulation of vitamin (biotin and thiamine) metabolism and lipid synthesis. Evolutionary analysis of HWS1/2 suggests that this gene pair has undergone incomplete lineage sorting (ILS) and multiple gene duplication events during speciation. Our findings have not only uncovered a pair of speciation genes that control hybrid breakdown but also illustrate a passive mechanism that could be scaled up and used in the guidance and optimization of hybrid breeding applications for distant hybridization.