"Double-edged sword" effect of reactive oxygen species (ROS) in tumor development and carcinogenesis.

Reactive oxygen species (ROS) are small reactive molecules produced by cellular metabolism and regulate various physiological and pathological functions. Many studies have shown that ROS plays an essential role in the proliferation and inhibition of tumor cells. Different concentrations of ROS can have a "double-edged sword" effect on the occurrence and development of tumors. A certain concentration of ROS can activate growth-promoting signals, enhance the proliferation and invasion of tumor cells, and cause damage to biomacromolecules such as proteins and nucleic acids. However, ROS can enhance the body's antitumor signal at higher levels by initiating oxidative stress-induced apoptosis and autophagy in tumor cells. This review analyzes ROS's unique bidirectional regulation mechanism on tumor cells, focusing on the key signaling pathways and regulatory factors that ROS affect the occurrence and development of tumors and providing ideas for an in-depth understanding of the mechanism of ROS action and its clinical application.

[Analysis of vocal fold vibration characteristics of spasmodic dysphonia by laryngeal high speed photography combined with glottis area wave].

Objective: To analyze the characteristics of vocal fold vibration of normal people and patients with spasmodic dysphonia (SD) using laryngeal high speed videoendoscopy combined with glottal area wave analysis. Methods: This prospective study examined twenty healthy subjects (10 males and 10 females), 12 patients with adductor spasmodic dysphonia(AdSD) (2 males,10 females)as AdSD group and 2 patients with abductor spasmodic dysphonia(AbSD) (2 males) as AbSD group. Twelve of healthy subjects (2 males,10 females) were selected as control group according to AdSD group gender match. All the subjects were recruited from the Department of Voice, Zhongshan Hospital, Xiamen University from October 2019 to December 2020. All subjects underwent laryngeal high speed videoendoscopy and 10 vibration periods were selected from each recording and were used to quantitatively analyze the change of glottal area and vocal fold vibration parameters (Speed Quotient (SQ), Open Quotient (OQ) and Close Quotient (CQ)). Results: 1. There were statistically significant differences in SQ, CQ and OQ between males and females in the healthy subjects (t=12.28, 5.59, 5.59, P<0.05). The change of the glottal area during each vibration period in healthy subjects was relatively stable(0.19-0.42). 2. The change of the glottal area during each vibration period in AdSD subjects had larger fluctuations, with the glottal area change index fluctuating in the range of 0.31 to 0.62. The SQ value of the AdSD group was significantly lower than that of control group (t=4.246, P<0.05). There were no significant differences in OQ and CQ between AdSD group and normal group (t=1.064, 1.332, P>0.05); The SQ value of the AbSD group tended to increase compared to normal group. Conclusions: Laryngeal high speed videoendoscopy combined with glottal area wave analysis has a certain reference value in the studying the vibration characteristics of SD patients. SQ has good specificity.

Applications of Cryogenic Electron Microscopy in Biomineralization Research.

Biological mineralization is a natural process manifested by living organisms in which inorganic minerals crystallize under the scrupulous control of biomolecules, producing hierarchical organic-inorganic composite structures with physical properties and design that galvanize even the most ardent structural engineer and architect. Understanding the mechanisms that control the formation of biominerals is challenging in the biomimetic engineering of hard tissues. In this regard, the contribution of cryogenic electron microscopy (cryo-EM) has been nothing short of phenomenal. By preserving materials in their native hydrated status and reducing damage caused by ion beam radiation, cryo-EM outperforms conventional transmission electron microscopy in its ability to directly observe the morphologic evolution of mineral precursor phases at different stages of biomineralization with nanoscale spatial resolution and subsecond temporal resolution in 2 or 3 dimensions. In the present review, the development and applications of cryo-EM are discussed to support the use of this powerful technique in dental research. Because of the rapid development of cryogenic sample preparation techniques, direct electron detection, and image-processing algorithms, the last decade has witnessed an exponential increase in the use of cryo-EM in structural biology and materials research. By amalgamating with other analytic techniques, cryo-EM may be used for qualitative and quantitative analyses of the kinetics and thermodynamic mechanisms in which organic macromolecules participate in the transformation of mineral precursors from their original liquid state to amorphous and ultimately crystalline phases. The present review concentrates on the biomineralization of calcium phosphate mineral phases, while that of calcium carbonate, silica, and magnetite is only briefly mentioned. Bioinspired organic matrix-mediated inorganic crystallization strategies are discussed from the perspective of tissue regeneration engineering.

Effects of Cryopreservation on Acrosin Activity and DNA Damage of Russian Sturgeon (Acipenser gueldenstaedtii) Semen.

BACKGROUND: Cryopreservation of sturgeon sperm can be successful, but there can be a decrease in sperm viability and the reasons are not clear. OBJECTIVE: To investigate variations in the acrosin activity and the DNA integrity of Acipenser gueldenstaedtii semen during cryopreservation at -196ºC. MATERIALS AND METHODS: Fish semen samples were randomly divided into three groups: [1] fresh control; [2] native semen diluted 1:1 with 23.4 mM sucrose + 0.25 mM KCl + 30 mM Tris (pH 8.0) and the addition of 10% methanol as cryoprotectant; and [3] semen without any diluents or cryoprotectants. Acrosin activity and DNA damage (COMET assay) were assessed. RESULTS: The average acrosin activity fell to 61% and 27% of the control for cryoprotected and non-cryoprotected semen after cryopreservation. The differences among the three groups were significant (P<0.05). We also observed that various indexes of DNA damage (L-tail; tail DNA, tail momentum, olive tail momentum) were higher in semen that had been frozen. CONCLUSION: Although cryopreservation of semen induces decreased acrosin activity and increased DNA damage, cryoprotectants can protect the semen during cryopreservation.

[Application of dynamic CT scan in the three-dimensional dynamic morphology changes of laryngeal soft tissue in unilateral vocal fold paralysis patients].

Objective: To explore the dynamic changes of three-dimensional morphology of laryngeal soft tissue and its clinical value in the unilateral vocal fold paralysis (UVFP) patients through dynamic CT scanning during the process from inspiration to phonation. Methods: From October 2017 to July 2019, a retrospective study was performed in 18 patients with UVFP (10 males and 8 females with the range of age from 29 to 75 years old) and 10 normal subjects (5 males and 5 females with the range of age from 25 to 58 years old) in Department of Voice-Otolaryngology Head and Neck Surgery, Section Two, Zhongshan Hospital Xiamen University. The laryngeal dynamic computed tomography (CT) of cine mode was performed. Ten dynamic sequence images of vocal folds movements were obtained during the process from inspiration to phonation. Based on the dynamic changes of glottic area and the displacement of cricoid cartilage. The above dynamic sequence images were divided into inspiratory phase and phonation phase as well as open phase and closed phase. The soft tissue parameters were measured respectively, including vocal folds length, width, thickness and subglottal convergence angle. Independent-sample t test was used to analyze between UVFP group and control group. Results: During the process from inspiration to phonation, the morphology of vocal folds in control group was relatively stable at inspiratory phase and closed phase in phonation. When open phase and closed phase of phonation were switching, the morphology of vocal folds changed obviously. The length of vocal folds became longer (1.19±0.10) mm, the width became wider (2.19±0.17) mm, the thickness became thinner (2.66±0.56) mm, and the subglottal convergence angle decreased (31.45±4.78)°. Compared with the controll group, in the open phase, the thickness and width of the vocal fold on affected side in the UVFP group were thinner (t=10.25, P<0.001) and wider (t=5.25, P<0.001).While in the closed phase, the subglottal convergence angle was larger (t=4.41, P=0.001).The width of the healthy side vocal fold in the UVFP was wider (t=2.54, P=0.026) than that in the control group. The differences in other parameters were not statistically significant. Conclusions: Dynamic laryngeal CT scanning provides a simple and non-invasive method for the objective and quantitative measurement of the dynamic changes of laryngeal morphology from inspiration to phonation. Compared with the control group, the characteristic dynamic changes among UVFP were observed during this particular process, which included changes of subglottal convergence angle and thickness of vocal muscle due to denervation. In addition, in UVFP group, the width of the vocal fold healthy side in the closed phase may be used to assess its compensatory function.

Meta-analysis of preoperative high-sensitivity cardiac troponin measurement in non-cardiac surgical patients at risk of cardiovascular complications.

BACKGROUND: Patients undergoing major non-cardiac surgery are at risk of cardiovascular complications. Raised levels of high-sensitivity troponin are frequently detected before operation among these patients. However, the prognostic value of high-sensitivity troponin in predicting postoperative outcomes remains unclear. METHODS: A systematic search of PubMed, Embase and Science Citation Index Expanded was undertaken for observational studies published before March 2018 that reported associations between raised preoperative levels of high-sensitivity troponin and postoperative major adverse cardiac events and/or mortality after non-cardiac surgery. Meta-analyses were performed, where possible, using random-effects models. RESULTS: Seven cohort studies with a total of 4836 patients were included. A raised preoperative high-sensitivity troponin level was associated with a higher risk of short-term major adverse cardiac events (risk ratio (RR) 2·92, 95 per cent c.i. 1·96 to 4·37; I2  = 82·6 per cent), short-term mortality (RR 5·39, 3·21 to 9·06; I2  = 0 per cent) and long-term mortality (RR 2·90, 1·83 to 4·59, I2  = 74·2 per cent). The addition of preoperative high-sensitivity troponin measurement provided improvements in cardiovascular risk discrimination (increase in C-index ranged from 0·058 to 0·109) and classification (quantified by continuous net reclassification improvement) compared with Lee's Revised Cardiac Risk Index alone. There was substantial heterogeneity and inadequate risk stratification analysis in the included studies. CONCLUSION: Raised preoperative levels of high-sensitivity troponin appear to represent a risk for postoperative major adverse cardiac events and mortality. Further study is required before high-sensitivity troponin can be used to predict risk stratification in routine clinical practice.

ANTECEDENTES: Los pacientes a los que se realiza una cirugía mayor no cardíaca tienen riesgo de presentar complicaciones cardiovasculares. En estos pacientes se observan con frecuencia niveles preoperatorios elevados de troponina de alta sensibilidad (high-sensitivity troponin, hs-cTn). Sin embargo, el valor pronóstico de la hs-cTn para predecir los resultados postoperatorios no está bien definido. MÉTODOS: Se realizó una búsqueda sistemática en las bases de datos PubMed, EMBASE y Science Citation Index Expanded de estudios observacionales publicados antes de marzo de 2018 que analizasen la posible relación de los niveles elevados preoperatorios de hs-cTn y los efectos adversos graves de tipo cardíaco (major adverse cardiac events, MACE) postoperatorios y/o la mortalidad después de la cirugía no cardíaca. Se realizó el metaanálisis utilizando modelos de efectos aleatorios siempre que fuera posible. RESULTADOS: Se incluyeron siete estudios de cohortes con un total de 4.836 pacientes. La elevación preoperatoria de hs-cTn se asoció con un mayor riesgo de MACE a corto plazo (tasa de riesgo, risk ratio, RR 2,92, i.c. del 95% 1,96-4,37, I2 = 82,6%) y con la mortalidad a corto plazo (RR 5,39, i.c. del 95 % 3,21-9,06, I2 = 0%) y a largo plazo (RR 2,90, i.c. del 95% 1,83-4,59, I2 = 74,2%). Añadir la medición preoperatoria de hs-cTn mejoró la capacidad discriminativa para el riesgo cardiovascular (aumento de 5,8% a 10,9% en el índice C) y también la clasificación de los pacientes (cuantificada mediante el índice de reclasificación neta continua) en comparación con el uso de solo el índice de riesgo cardíaco revisado de Lee. En los estudios incluidos, hubo gran heterogeneidad y análisis inadecuado de la estratificación del riesgo. CONCLUSIÓN: Los niveles preoperatorios elevados de troponina de alta sensibilidad parecen ser un marcador de riesgo de efectos adversos graves de tipo cardíaco en el postoperatorio y de mortalidad. Se requieren más estudios antes de utilizar la troponina de alta sensibilidad para la estratificación del riesgo en la práctica clínica rutinaria.

Properties of oscillatory neuronal activity in the basal ganglia and thalamus in patients with Parkinson's disease.

BACKGROUND: The cardinal features of Parkinson's disease (PD) are bradykinesia, rigidity and rest tremor. Abnormal activity in the basal ganglia is predicted to underlie the mechanism of motor symptoms. This study aims to characterize properties of oscillatory activity in the basal ganglia and motor thalamus in patients with PD. METHODS: Twenty-nine patients with PD who underwent bilateral or unilateral electrode implantation for subthalamic nucleus (STN) DBS (n = 11), unilateral pallidotomy (n = 9) and unilateral thalamotomy (n = 9) were studied. Microelectrode recordings in the STN, globus pallidus internus (GPi) and ventral oral posterior/ventral intermediate of thalamus (Vop/Vim) were performed. Electromyography of the contralateral limbs was recorded. Single unit characteristics including interspike intervals were analyzed. Spectral and coherence analyses were assessed. Mean spontaneous firing rate (MSFR) of neurons was calculated. Analysis of variance and X2 test were performed. RESULTS: Of 76 STN neurons, 39.5% were 4-6 Hz band oscillatory neurons and 28.9% were ß frequency band (ßFB) oscillatory neurons. The MSFR was 44.2 ± 7.6 Hz. Of 62 GPi neurons, 37.1% were 4-6 Hz band oscillatory neurons and 27.4% were ßFB neurons. The MSFR was 80.9 ± 9.6 Hz. Of 44 Vop neurons, 65.9% were 4-6 Hz band oscillatory neurons and 9% were ßFB neurons. The MSFR was 24.4 ± 4.2 Hz. Of 30 Vim oscillatory neurons, 70% were 4-6 Hz band oscillatory neurons and 13.3% were ßFB neurons. The MSFR was 30.3 ± 3.6 Hz. Further analysis indicated that proportion of ßFB oscillatory neurons in STN and GPi was higher than that of similar neurons in the Vop and Vim (P < 0.05). Conversely, the proportion of 4-6 Hz band oscillatory neurons and tremor related neurons in the Vim and Vop was higher than that of STN and GPi (P < 0.05). The highest MSFR was for GPi oscillatory neurons whereas the lowest MSFR was for Vop oscillatory neurons (P < 0.005). CONCLUSION: The alterations in neuronal activity in basal ganglia play a critical role in generation of parkinsonism. ß oscillatory activity is more prominent in basal ganglia than in thalamus suggesting that the activity likely results from dopaminergic depletion. While both basal ganglia and thalamus have tremor activity, the thalamus appears to play a more important role in tremor production, and basal ganglia ß oscillatory activity might be the trigger.

Association of fish and long-chain omega-3 fatty acids intakes with total and cause-specific mortality: prospective analysis of 421 309 individuals.

BACKGROUND: Prevailing dietary guidelines recommend regular fish consumption. However, the associations of fish and long-chain omega-3 polyunsaturated fatty acids (LCn-3 PUFAs) intakes with mortality remain unclear. OBJECTIVES: To examine the associations of fish and LCn-3 PUFAs intakes with total and cause-specific mortality. METHODS: A total of 240 729 men and 180 580 women from NIH-AARP Diet and Health Study were prospectively followed-up for 16 years. Dietary intakes were assessed using a validated NIH Diet History Questionnaire. RESULTS: A total of 54 230 men and 30 882 women died during 6.07 million person-years of follow-up. Higher fish and LCn-3 PUFAs intakes were significantly associated with lower total mortality (P < 0.0001). Comparing the highest with lowest quintiles of fish intake, men had 9% (95% confidence interval, 6-11%) lower total mortality, 10% (6-15%) lower cardiovascular disease (CVD) mortality, 6% (1-10%) lower cancer mortality, 20% (11-28%) lower respiratory disease mortality and 37% (17-53%) lower chronic liver disease mortality, while women had 8% (5-12%) lower total mortality, 10% (3-17%) lower CVD mortality and 38% (20-52%) lower Alzheimer's disease mortality. Fried fish consumption was not related to mortality in men whereas positively associated with mortality from all causes (P = 0.011), CVD and respiratory disease in women. LCn-3 PUFAs intake was associated with 15% and 18% lower CVD mortality in men and women across extreme quintiles, respectively. CONCLUSION: Consumption of fish and LCn-3 PUFAs was robustly associated with lower mortality from major causes. Our findings support current guidelines for fish consumption while advice on non-frying preparation methods is needed.

[Effect of cricothyroid and thyroarytenoid muscle botulinum toxin injection on patients with dyspnea caused by bilateral recurrent laryngeal nerve paresis].

Objective: To discuss the clinical effect of small dose of botulinum toxin injection in cricothyroid muscle and thyroarytenoid muscle on patients with incomplete bilateral recurrent laryngeal nerve paresis. Methods: Six patients were selected with Ⅰor Ⅱ or Ⅲ degree of dyspnea diagnosed as bilateral recurrent laryngeal nerve injury by laryngeal electromyography, and small dose of botulinum toxin injection was performed in cricothyroid muscle and thyroarytenoid muscle as a treatment. Degree of dyspnea was assessed one month before and after the treatment, and the stroboscopic laryngoscope results, acoustic parameters and CT image of the patients were collected in the 6 patients. The relevant parameters were also collected one month before and after treatment, including the degree of dyspnea, stroboscopic laryngoscope results, acoustic parameters and CT image of the patients. The angle between bilateral vocal cords in stroboscopy at full inspiratory was calculated, acoustic parameters (F0, jitter, shimmer) were analysed, and vocal length, width and the vocal region were measured. Then, the paired t test was performed for statistical analysis between before and after one month injection, the one way analysis of variance was performed among vocal parameters in CT image. Result: Botulinum toxin injection was successfully completed in the 6 patients, followed without any serious complications. The degree of dyspnea was alleviated to some extent after treatment in all 6 patients; the angle between bilateral vocal cords at the end of a deep inspiration was significantly increased (t=2.44, P<0.05) after the treatment. The changes of F0 and jitter between before and after treatment were not statistically significant (t=0.72, t=1.42, P>0.05). Shimmer was significantly decreased after treatment (t=2.61, P<0.05). Vocal fold length, width and vocal region increased with F0, there was a statistically significant difference between different F0 before injection, and there was no statistically significant difference between different F0 after injection. The follow-up time was respectively seven months, 1 year, 1 year, 18 months, 22 months and 2 years respectively. Conclusion: Small dose of botulinum toxin injection in bilateral cricothyroid muscles and thyroarytenoid muscles can relieve the dyspnea caused by bilateral vocal cords paresis to some extent, accompanied without serious complications, despite the sound quality was slightly worse.

[Effect of extent of glottal incompetence on phonation in excised canine larynx models].

Objective: To compare the acoustic signal, mucosal wave and aerodynamic parameter (phonation threshold pressure, PTP) under different sub-glottal pressure (SGP) on the excised canine models with different extent of glottal incompetence. Methods: Perturbation measures and nonlinear dynamic measures were applied to analyze the acoustic signal (jitter, shimmer), mucosal wave [frequency(F), amplitude(A), phase(P)] and PTP from our study including 11 excised canine larynges with different extent of glottal incompetence (0 mm, 1 mm, 2 mm, 3 mm, n=11, respectively) under 1-4 kPa sub-glottal pressure. Results: There were significant differences between different groups in jitter, shimmer, amplitude, frequency and PTP under various SGPs and extent of glottal incompetence (all P<0.05), inversely, there was no significant difference in P between groups (P>0.05). Jitter and shimmer changed obviously when the SGP increased to 3 kPa in the control group and GI 1 mm group. Jitter and shimmer changed obviously when the SGP increased to 2 kPa in the GI 2 mm and 3 mm groups. The F and A of mucosal wave increased with increasing SGP, decreased with increasing GI, and the P changed irregularly. There was statistically significant difference of PTP between different GI groups. Conclusions: The SGP and the extent of GI had obvious affection on the the acoustic signal, mucosal wave and aerodynamic parameters.

Subthalamic oscillatory activity in parkinsonian patients with off-period dystonia.

OBJECTIVES: The study was aimed to explore oscillatory activity in the subthalamic nucleus (STN) in Parkinson's disease (PD) with off-period dystonia, a type of levodopa-induced dyskinesias (LID). METHODS: Eighteen patients with PD who underwent STN DBS were studied. Nine patients had dyskinesia defined as the LID group and nine patients who did not present any sign of dyskinesia were defined as the control group. Microelectrode recordings in the STN together with electromyogram (EMG) were recorded. Spectral and coherence analyses were performed to study the neuronal oscillations in relation to limb muscles. RESULTS: Two hundred and fifteen neurons were identified. There were 39 neurons with tremor-frequency band (4-7 Hz) oscillation, 57 neurons with ß-frequency band (12-30 Hz, ß-FB) oscillation and 100 neurons without oscillation, and 19 neurons with very low-frequency band oscillation at a mean peak power of 1.2 ± 0.5 Hz (LFB). These LFB oscillatory neurons (n = 15) were frequently significantly coherent with EMG of off-period dystonia. Notably, 89% (n = 17) neurons with LFB oscillation were found in the patients in the off-dystonia group. The age at onset of PD, duration of PD, and levodopa equivalent dose daily consumption were statistically different between two groups (P < 0.05). CONCLUSIONS: Subthalamic LFB oscillatory neurons seem to play an important role in the genesis of off-period dystonia in advanced PD. Clinical and demographic analyses confirmed that the earlier age at onset of PD, longer duration of PD, and levodopa exposure are important risk factors in the development of the type of LID.

RUNX3 promoter methylation correlation with pathogenesis of hepatocellular carcinoma in Asians.

The aim of this study was to elucidate the role of RUNX3 promoter methylation in the pathogenesis of hepatocellular carcinoma (HCC) among Asians. For this purpose, we performed a comprehensive search of Chinese and English language scientific literature databases using stringent selection criteria; ultimately, we identified relevant studies that specifically assessed the correlation between RUNX3 promoter methylation and HCC. All data was retrieved and analyzed by two independent investigators using the STATA software (version 12.0). Initially, 132 studies (103 in Chinese, 29 in English) were retrieved; 122 were eliminated through a stepwise filtering process. Finally, 10 studies conducted in Asian populations (5 Chinese, 4 Japanese, 1 Korean) fulfilled all the inclusion criteria of our meta-analysis. The studies included 588 HCC patients (641 cancer tissues; 593 adjacent normal tissues) and 184 healthy controls. We observed that RUNX3 promoter methylation was significantly higher in cancer tissues than in adjacent normal tissues (RR = 6.35, 95%CI = 3.62-11.14, P < 0.001) and normal control tissues (RR = 17.31, 95%CI = 7.08-42.34, P < 0.001). RUNX3 promoter methylation status did not differ significantly between patients with different TNM stages (RR = 0.88, 95%CI = 0.70-1.10, P = 0.269) and histological grades (RR = 0.86, 95%CI = 0.65-1.14, P = 0.304), suggesting that RUNX3 promoter methylation is linked to the origin of HCC but not to its progression from non-metastatic to metastatic stages. This in turn indicated that RUNX3 could be an early diagnostic marker distinguishing benign from malignant hepatocellular carcinoma.

Effects of missense mutations in sortase A gene on enzyme activity in Streptococcus mutans.

BACKGROUND: Streptococcus mutans (S. mutans) is the major aetiological agent of dental caries, and the transpeptidase Sortase A (SrtA) plays a major role in cariogenicity. The T168G and G470A missense mutations in the srtA gene may be linked to caries susceptibility, as demonstrated in our previous studies. This study aimed to investigate the effects of these missense mutations of the srtA gene on SrtA enzyme activity in S. mutans. METHODS: The point mutated recombinant S.mutans T168G and G470A sortases were expressed in expression plasmid pET32a. S. mutans UA159 sortase coding gene srtA was used as the template for point mutation. Enzymatic activity was assessed by quantifying increases in the fluorescence intensity generated when a substrate Dabcyl-QALPNTGEE-Edans was cleaved by SrtA. The kinetic constants were calculated based on the curve fit for the Michaelis-Menten equation. RESULTS: SrtA△N40(UA159) and the mutant enzymes, SrtA△N40(D56E) and SrtA△N40(R157H), were expressed and purified. A kinetic analysis showed that the affinity of SrtA△N40(D56E) and SrtA△N40(R157H) remained approximately equal to the affinity of SrtA△N40(UA159), as determined by the Michaelis constant (K m ). However, the catalytic rate constant (k cat ) and catalytic efficiency (k cat /K m ) of SrtA△N40(D56E) were reduced compared with those of SrtA△N40(R157H) and SrtA△N40(UA159), whereas the k cat and k cat /K m values of SrtA△N40(R157H) were slightly lower than those of SrtA△N40(UA159). CONCLUSIONS: The findings of this study indicate that the T168G missense mutation of the srtA gene results in a significant reduction in enzymatic activity compared with S. mutans UA159, suggesting that the T168G missense mutation of the srtA gene may be related to low cariogenicity.

[A study on the X-ray measurement predictors of difficult laryngealexposure in patients undergoing microlaryngosurgery].

Objective:This paper seeks to identify useful and reliable indicators for predicting the occurrence of difficult laryngeal exposure(DLE) in microlaryngosurgery.Method:Sixty-two patients were given physical examinations,including 4 general parameters:age,sex,BMI,and MMI,and 14 physical measurement parameters(TA,UIA,LIA,IG,LIMD,MA,MCD,MH,MDI,HMD,TMD,SMD,TMA,THUIA).Univariate analysis,stepwise regression analysis and ROC curve analysis were employed to identify parameters with the potential to predict DLE.Result:We found sex(P<0.05) showed significant correlation with the laryngeal exposure score(P<0.05).We also found LIMD,MA,TMA and THUIA to be reliable DLE predictors.The cutoff values for predicting DLE were LIMD>4.53cm,MA>115.5°,TMA>99.2°,and THUIA>152.6°.Conclusion:X-ray measurement predictors of LIMD,MA,TMA,and THUIA before operation are important for the prediction of DLE.Sex is also the reliable DLE predictor.Males were prone to DLE.

[The role of acoustic analysis of fundamental frequency in differentiating arytenoid dislocation from vocal fold paralysis].

Objective:Analysis of the sustained vowels of acoustic parameters in arytenoid dislocation and vocal fold paralysis. To investigate their acoustic characteristics and evaluate the role of this acoustic analysis method in differentiating arytenoid dislocation from vocal fold paralysis. Method:Thirty-three cases with unilateral vocal cord movement disorders were collected.All cases were divided into arytenoid dislocation group and vocal fold paralysis group through the laryngeal electromyography. Each group was further devided into male group and female group. The voice signals of sustained vowel of /a/ were measured using the software MDVP and obtain the acoustic parameters(Jitter, Shimmer, SPI and Fo). The acoustic characteristics between the two groups were observed and compared. Results were analyzed using Rank sum test for group design.Result:There were significant differences in Fo between arytenoid dislocation group and vocal fold paralysis group in both male and female group（P <0.05）. And mean rank order of Fo in arytenoid dislocation group was greater than vocal fold paralysis group. There were no significant differences in jitter,shimmer and SPI between arytenoid dislocation group and vocal fold paralysis group（P >0.05）.Conclusion:Mean rank order of Fo in arytenoid dislocation group is greater than vocal fold paralysis group in both the male and the female group. Fo is of value in differentiating arytenoid dislocation from vocal fold paralysis. This provides a theoretical basis for the acoustic analysis method to identify these two diseases.

Isosmotic points and their ecological significance for juvenile Chinese sturgeon Acipenser sinensis.

Serum osmolality and ion concentrations were measured in juvenile Chinese sturgeon Acipenser sinensis at different salinities to determine the isosmotic point. Isosmotic and isoionic concentrations were calculated from the regressions for serum and ambient osmolality, with Na(+) , Cl(-) and K(+) as salinities 9·19, 8·17, 7·89 and 9·70, respectively. These values were consistent with the salinity of the habitat where juvenile A. sinensis occur in the Yangtze Estuary, suggesting that an isosmotic salinity is an important factor driving their habitat choice.

Effects of cryopreservation on motility characteristics and enzyme activity of sperm in a Chinese fish Nibea albiflora.

BACKGROUND: Growing evidence suggests that among the causes which deteriorate qualitative and functional characteristics of sperm after freezing and thawing, there are those linked to decrease of sperm motility and release of various enzymes in the cells and seminal plasma. OBJECTIVE: In the present study, the motility, fertilization and enzyme activity of sperm were analyzed after cryopreservation. MATERIALS AND METHODS: Computer-assisted sperm motility analysis (CASA) was used to evaluate the effect of cryopreservation on sperm motility of Nibea albiflora. RESULTS: The activities of total adenosine triphosphatase (ATPase), creatine kinase (CK), succinate dehydrogenase (SDH), lactate dehydrogenase (LDH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GR) in fresh and frozen seminal plasma and spermatozoa were measured respectively. Cryopreservation led to a decline in the percentage of motile sperm, moreover, other parameters of sperm motion, curvilinear and straight line velocities, linearity were changed observably (p < 0.05), the fertilizing capacity of post-thaw sperm was lower than that of the fresh sperm significantly. After cryopreservation, the activities of total ATPase, CK, SDH, LDH, SOD, CAT and GSH-Px increased in seminal plasma and decreased in spermatozoa respectively, but GR activity varied contrarily, GR activity dropped in seminal plasma and increased in spermatozoa. CONCLUSION: Cryopreservation had significant effects on the motility characteristics, fertilization ability and enzyme activity of the sperm of Nibea albiflora.