Comparison of the stability of different concentrations of fluorescein sodium on the detection of tear film rupture time / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To analyze the stability of different concentrations of fluorescein sodium solution on the detection of tear break-up time(TBUT).METHODS:A retrospective study. A total of 150 cases(150 eyes)who came to our dry eye clinic with good cooperation from August 2019 to September 2021 were selected for the study, and the subjects were randomly divided into five groups, which were fluorescein sodium(FLS, 0.5%), FLS(1.0%), FLS(1.5%), FLS(2.0%)and fluorescein sodium parallel(FLSP), with 30 patients in each group(all the right eyes were the subject eyes). Each group was dripped with the corresponding fluorescein sodium. The FLSP group was the fluorescent test strip detection group. The slit lamp image scores of different concentration groups were compared, the survival time of sodium fluorescein at the instant, 2, 5, 10, 15 and 30min points was observed in each group, and the mean value of TBUT in each group was recorded.RESULTS: The image score of FLS(0.5%)group was significantly higher than that of the other four groups(t=7.746, 21.483, 116.190, 38.730, all P<0.01). The image score of FLS(1.0%)group was significantly higher than that of FLS(1.5%)and FLS(2.0%)group(t=10.742, 15.492, all P<0.01). The survival time of fluorescein in FLS(0.5%)group was significantly shorter than that of the other four groups(t=8.226, 7.458, 9.159, 12.347, all P<0.01). The survival time of fluorescein in FLS(1.5%)group was significantly longer than that of FLS(1.0%)and FLS(2.0%)group(t=15.428, 13.274, all P<0.05). TBUT in FLS(0.5%)group was significantly higher than that of the other four groups at 2min(t=22.767, 22.345, 15.494, 17.213, all P<0.01), and was significantly lower than that of the other four groups at 10min(t=23.266, 25.353, 10.183, 22.025, all P<0.01). The mean first TBUT of FLS(1.5%)group was significantly shorter than that of the other four groups(t=25.236, 21.374, 19.658, 72.341, all P<0.01), and the mean first TBUT of FLSP group was significantly longer than that of the other four groups(t=22.487, 30.267, 60.247, 40.857, all P<0.01). There was no significant correlation between TBUT and ocular surface disease index(OSDI)and tear river height(rs=-0.072, 0.219, P=0.689, 0.112). TBUT was positively correlated with tear secretion(rs=0.674, P<0.01).CONCLUSION: FLS(0.5%)had higher image quality but it was only suitable for observing staining within 5min, and the FLSP group was more suitable for clinical observation of corneal fluorescence staining for a longer period; FLS(1.5%)was the most stable and reliable concentration and dose for the detection of TBUT.

Clinical characteristics of 70 patients with coronavirus disease 2019 accompanied with diarrhea / 中华消化杂志

Objective:To retrospectively analyze the clinical characteristics of patients with coronavirus disease 2019 (COVID-19) accompanied with diarrhea.Methods:From January 11 to February 6 in 2020, the clinical data of 663 patients diagnosed with COVID-19 admitted to Renmin Hospital of Wuhan University were collected and divided into diarrhea group and non-diarrhea group according to whether they had diarrhea or not. The differences in baseline characteristics, basic disease history, clinical manifestations, chest computed tomography (CT), laboratory findings, disease severity and mortality between the two groups were compared. Chi-square test and Fisher exact test were used for statistical analysis.Results:Among 663 COVID-19 patients, 70 (10.6%) patients accompanied with diarrhea. The proportion of fatigue and increased lactate dehydrogenase (LDH) levels of diarrhea group were higher than those of non-diarrhea group (58.6%, 41/70 vs. 28.2%, 167/593; and 64.2%, 43/67 vs. 50.4%, 277/550), and the differences were statistically significant ( χ2=26.891 and 4.566, both P<0.05). There was no statistically significant difference in the proportion of pneumonia in chest CT between diarrhea group and non-diarrhea group (100.0%, 62/62 vs. 99.4%, 529/532) ( P>0.05). There were no statistically significant differences in the proportions of mild and normal type, severe type and critical type between diarrhea group and non-diarrhea group (35.7%, 25/70 vs. 38.6%, 229/593; 50.0%, 35/70 vs. 47.2%, 280/593; and 14.3%, 10/70 vs. 14.2%, 84/593, respectively) (all P>0.05). There were no statistically significant differences in the mortality of mild and normal type, severe type and critical type between diarrhea group and non-diarrhea group (0 vs. 0.5%, 3/593; 0 vs. 0 and 1.4%, 1/70 vs. 3.5%, 21/593) (all P>0.05). Conclusions:Patients with COVID-19 accompanied with diarrhea are more likely to have fatigue and increased LDH level. Diarrhea is not significantly correlated with the disease severity of patients with COVID-19.

Resonance light scattering spectroscopy can directly characterize protein solubility / 南方医科大学学报

OBJECTIVE@#To develop a fast, sensitive and cost-effective method based on resonance light scattering (RLS) for characterization of protein solubility to facilitate detection of changes in solubility of mutant proteins.@*METHODS@#We examined the response curve of RLS intensities to the protein concentrations in synchronous scanning mode. The curve intersection points were searched to predict the maximal concentrations of the protein in dispersion state, which defined the solubility of the protein in this given state. Bovine serum albumin (BSA, 0-50 g/L) was used as the model to investigate the influences of pH values (6.5, 7.0, and 7.4) and salt concentrations (0.05, 0.10, 0.15, and 0.20 mol/L) on the determined solubility. The solubility of glutathione S-transferase isoenzymes alpha (GSTA, 0-27.0 g/L) and Mμ (GSTM, 0-20.0 g/L) were estimated for comparison. The RLS-based method was used to determine the solubility of uricase (MGU, 0-0.4 g/L) to provide assistance in improving the solubility of its mutants.@*RESULTS@#We identified two intersection points in the RLS response curves of the tested proteins, among which the lower one represented an approximation of the maximal concentration (or the solubility of the protein) in single molecular dispersion, and the higher one the saturated concentration of the protein in multiple molecular aggregation. In HEPES buffer, the two intersection points of BSA (isoelectric point 4.6) both increased with the increase of pH (6.5-7.4), and their values were ~1.2 g/L and ~33 g/L at pH 7.4, respectively; the latter concentration approached the solubility of commercial BSA in the same buffer at the same pH. The addition of NaCl reduced the values of the two intersection points, and increasing salt ion concentration decreased the values of the lower intersection points. Further characterizations of GSTA and GSTM showed that the low concentration intersection points of the two proteins were ~0.7 g/L and ~0.8 g/L, and their high concentration intersection points were ~10 g/L and ~11 g/L, respectively, both lower than those of BSA, indicating the feasibility of the direct characterization of protein solubility by RLS. The two concentration intersection points of MGU were 0.24 g/L and 0.30 g/L, respectively, and the low concentration intersection point of its selected mutant was increased by 2 times.@*CONCLUSIONS@#RLS allows direct characterization of the solubility of macromolecular proteins. This method, which is simple and sensitive and needs only a small amount of proteins, has a unique advantage for rapid comparison of solubility of low-abundance protein mutants.

Characterization of Mycobacterium tuberculosis dihydrofolate reductase immobilized on magnetic nanoparticles / 生物工程学报

To explore the immobilization of target proteins for screening libraries of ligand mixtures, magnetic submicron particles (MSP) functionalized with Ni²⁺-NTA and carboxyl were compared for the immobilization of Mycobacterium tuberculosis dihydrofolate reductase (MtDHFR). MtDHFR fused with 6×His was expressed, purified and characterized for kinetics. MtDHFR was immobilized on Ni²⁺-NTA-functionalized MSP directly and carboxyl-functionalized MSP upon activation. The immobilization capacity, residual activity, thermostability and affinities for putative inhibitors were characterized. MtDHFR immobilized on Ni²⁺-NTA-functionalized MSP retained about 32% activity of the free one with the immobilization capacity of (93±12) mg/g of MSP (n=3). Ni²⁺ and EDTA synergistically inhibited MtDHFR activity, while Fe³⁺ had no obvious interference. MtDHFR immobilized on carboxyl-functionalized MSP retained (87±4)% activity of the free one with the immobilization capacity of (8.6±0.6) mg/g MSP (n=3). In 100 mmol/L HEPES (pH 7.0) containing 50 mmol/L KCl, there was no significant loss of the activities of the free and immobilized MtDHFR after storage at 0 °C for 16 h, but nearly 60% and 35% loss of their activities after storage at 25 °C for 16 h, respectively. The inhibition effects of methotrexate on the immobilized and free MtDHFR were consistent (P>0.05). The immobilization of MtDHFR on carboxyl-functionalized MSP was thus favorable for higher retained activity and better thermostability, with promise for rapid screening of its ligand mixtures.

Simulation-based medical education and its implementation in neonatal asphyxia resuscitation training / 中华医学教育探索杂志

Simulation-based medical education is a new teaching method using modern intelligent science and technology to carry out clinical practice training,This article analyzes the current situation of simulation teaching training in neonatal asphyxia resuscitation and discusses its advantages,namely highly simulated and repetitive teaching scene,safe and reliable teaching process,potentially incentive teaching environment,flexible teaching content and cooperation of the teaching team.

Comparison of Different Dosages of Rocuronium on Abdominal Wound Closure / 昆明医科大学学报

Objective To evaluate the effects of different dosages of rocuronium on abdominal wound closure under general anesthesia.Methods Ninety ASA class I or II patients scheduled for elective abdominal surgery under general anesthesia were randomized into three groups with 30 cases each.Each group received rocuronium 1 time of ED95 (0.3 mg/kg),0.5 time of ED95 (0.15 mg/kg),0.2 time of ED95 (0.06 mg/kg) respectively when closing the abdominal wall.TOF recovered to 25%, 75%, 90%, time of eye-opening on command, time of head-lift for more than 5 seconds,extubation time, the rate of upper airways obstruction after extubation and the satisfaction score for the muscle relaxation to general surgeons were recorded.Results TOF values had no significantly different among the three groups before abdominal wound closure (P＞0.05).Compared with group A and group B,time of TOF in group C was significangtly increased after administration of rocuronium (P＜0.05) . Time of TOF recovery to 25%, 75%, 90%in group C were significangtly decreased (P＜0.01).Compared with group A and group B, time of eye-opening on command ,head-lift for more than 5 seconds and extubation time were significantly shorter in group C.There were 8,4,0 patients undwent upper airways obstruction among each group respectively after extubation (P＜0.05).The satisfaction score for muscle relaxation among three groups had no significant difference.Conclusion An additional administration of 0.2 time of ED95 (0.06 mg/kg) rocuronium before abdominal wound closure in abdominal surgery can achieve satisfactory muscle relaxation for surgeons.

MicroRNA-373 Inhibits Cell Proliferation and Invasion via Targeting BRF2 in Human Non-small Cell Lung Cancer A549 Cell Line / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The purpose of this study was to investigate the biological role and mechanism of miR-373 targeting of TFIIB-related factor 2 (BRF2) in the regulation of non-small cell lung cancer (NSCLC) cells. MATERIALS AND METHODS: miRNA microarray chip analysis of four paired NSCLC and adjacent non-tumor tissues was performed. Quantitative real-time polymerase chain reaction (qRT-PCR) andwestern blotting were used to detect the expression levels of miR-373 and BRF2 in NSCLC tissues and cell lines. The dual-luciferase reporter method was performed to determine if BRF2 is a target of miR-373. MTT, wound-healing, Transwell, and flow cytometric assays were conducted to examine the proliferation, migration, invasion, and cell cycle progression of NSCLC A549 cells, respectively; western blotting was used to detect the expression of epithelial-mesenchymal transition (EMT)–related proteins. RESULTS: The miRNA microarray chip analysis demonstrated that miR-373 was down-regulated in NSCLC tissues, and this result was confirmed by qRT-PCR. Additionally, miR-373 was confirmed to target BRF2. Moreover, miR-373 expression was inversely correlated with BRF2 expression in NSCLC tissues and cell lines; both miR-373 down-regulation and BRF2 up-regulation were strongly associated with the clinicopathological features and prognosis of NSCLC patients. In vitro, overexpression of miR-373 markedly inhibited cell proliferation, migration, and invasion; up-regulated the expression of E-cadherin; and down-regulated the expression of N-cadherin and Snail in A549 cell. Knockdown BRF2 by siRNA resulted in effects similar to those caused by overexpression of miR-373. CONCLUSION: MiR-373 is decreased in NSCLC, and overexpression of miR-373 can suppress cell EMT, and inhibit the proliferation, migration, and invasion of NSCLC A549 cells by targeting BRF2.

Prediction of maximum absorption activities with polyclonalantibodies immobilized on magnetic submicron particles torecognize positive mutants / 西安交通大学学报(医学版)

Objective To observe polyclonal antibodies immobilized on magnetic submicron particles (MSP) as affinity adsorbents and test the reliability of predicted maximum adsorption activity of an enzyme/mutant from a cell lysate (Vs) in recognizing positive mutants.Methods Escherichia coli alkaline phosphatase (ECAP) and Pseudomonas Aeruginosa arylsulfatase (PAAS) were purified by affinity chromatography to serve as immunogens for the preparation of their antisera, which after fractionation by 33％ ammonium sulfate and DEAE-cellulose chromatography yielded the respective polyclonal antibodies.After activation of COOH on MSP, polyclonal antibodies of each enzyme were immobilized to give MSP-polyAb.Activities of an adsorbed enzyme were measured with a chromogenic substrate of 4-nitrphenol by determining absorbance at 405nm after the termination of reaction by alkali.Based on the response curve of activities of the adsorbed enzyme to protein quantities of a lysate, Vs was predicted for comparison.Results The maximum adsorption quantity of ECAP or PAAS on the respective MSP-polyAb was about 2.0mg/g.Specific activity of ECAP after affinity purification was about 70-fold of that of PAAS.ECAP mutant R168K showing about 50％ activity improvement versus ECAP was recognized by comparison of Vs predicted with only 2.5μg of MSP-polyAb;with PAAS mutant G138S as the starting one, the use of 10.0μg of MSP-polyAb to predict Vs recognized the mutants bearing more than 20％ activity improvement.Conclusion With an optimized quantity of MSP-polyAb to predict Vs, weak positive mutants of an enzyme of low activity can be recognized when activities of the adsorbed enzyme/mutant are reliably measured.

A follow up observation of the effects of preventive measures on iodine deficiency disorders in Aksu, Xinjiang / 中华地方病学杂志

Objective To evaluate the iodine nutritional condition among populations in Aksu after implementing free iodized salt in population of Xinjiang.Methods According to the National Iodine Deficiency Monitoring Programme (Revised),totally 45 villages (towns) of subordinated 8 counties and Aksu City,Xinjiang were selected for collecting salt samples.Meanwhile,in 27 villages (towns) primary schools,school-aged children (8-10 years old) were selected for collecting disposable urine samples,B ultrasound was used to check thyroid volume and intelligence (IQ) was evaluated by China Combined Raven Test (CRT).Pregnant women were sampled for collecting their disposable urine near the primary schools.Both the children and pregnant women were evaluated the iodine deficiency disorders (IDD) knowledge awareness by questionnaire.The urine iodine concentration was measured by the ammonium persulfate digestion-As-Ce catalytic spectrophotometer method.The salt iodine concentration was measured by the direct titrimetric method,and other kinds of iodine in salt were measured by referee method (GB/T 13025.7-2012).Results A total of 2 700 household salt samples were collected,the average of iodine concentration in household salt was (26.95 ± 5.10) mg/kg.The coverage of household iodized salt was 98.56％ (2 661/2 700).The coverage of edible iodized salt was 98.00％ (2 646/2 700).A total of 2 159 urine samples were collected,the median of urine iodine concentration (UIC) among school-aged children (8-10 years old) was 235.50 μg/L.The total goiter rate was 1.51％ (33/2 179) among children aged 8-10 years old.A total of 2 098 people were conducted IQ test,the average IQ was 88.03 ± 17.14.A total of 1 047 urine samples were collected,the median of UIC among pregnant women was 213.50 μg/L.The IDD knowledge awareness rate of children and women were 98.82％ (751/760) and 99.23％ (258/260),respectively.Conclusions The iodine nutrition is in an adequate range,awareness of IDD prevention is obviously improved among children which is representative of common people and pregnant women after implementing the free iodized salt in population of Xinjiang in Aksu.The policy of preventing IDD based on this policy has showed enormous effect.

The cultivation of long-term-system medical undergraduates' innovative ability with the aid of extracurricular scientific and technological activities / 中华医学教育探索杂志

An auxiliary training system was explored for the development of creativity of long-termsystem medical undergraduates through scientific researches in spare time.In practice,professionals from research groups of different disciplines were recruited for developing wide-scope theoretical and technical bases of the undergraduates through training among these research groups followed by focused researches on topics of the running projects of these professionals.The undergraduates were engaged in a serial of research activities,including the discovery of problems for reasoning out scientific research projects,the writing of their project proposals,the summary of their data and the writing of reports,to develop their creativity and their qualification for scientific researches.

Research advance on intervertebral disc degeneration and cell death / 中国骨伤

Intervertebral disc degeneration is considered as a primary cause of clinical low back pain, however the molecular mechanism is not clear yet. Recently, researches on the molecular basis of intervertebral disc degeneration have become a hotspot. The special structure and biomechanics properties of the disc contribute to its propensity toward degeneration. Intervertebral disc degeneration is associated with the changes of the cytological behavior,including the increase in cell death and the degradation of extracellular matrix. However, the mechanism of cell death including cell apoptosis and autophagy in intervertebral disc degeneration remains unclear. Further study on the molecular mechanism of intervertebral disc degeneration is the foundation of improving and treating the intervertebral disc degeneration in the future. Although some progresses are made in the aspect of biological study, the biological environment of intervertebral disc itself is still a challenge for the development of biological treatment. This article is to review the latest advance on the biological characteristics of normal intervertebral disc and the cell death in the process of the intervertebral disc degeneration.

Unsedated versus sedated gastrointestinal endoscopy: A questionnaire investigation in Wuhan, central China / 华中科技大学学报（医学）（英德文版）

National data show that in China mainland unsedated gastrointestinal (GI) endoscopy has been applied in most hospitals for clinical examination, while sedated GI endoscopy is only performed in some hospitals. The purpose of this study was to compare sedated versus unsedated GI endoscopy regarding cost, safety, degree of comfort, tolerance level and overall satisfaction of patients over a 6-month period investigation. From March to September 2011, a questionnaire survey was performed on 1800 patients and 30 physicians at Zhongnan Hospital of Wuhan University and Wuhan General Hospital of Guangzhou Military Command. The patients fell into two groups according to their own decisions: the unsedated group (n=1000) and the sedated group (n=800). After examination, the patients and the physicians were required to fill in a questionnaire form. All the data were analyzed statistically. The results showed that the main factors the patients took for consideration between sedated and unsedated procedures included economy, comfort and safety. The income levels between the sedated and unsedated groups showed significant difference (P<0.01). Most patients in the unsedated group had lower income and were covered by less medical insurance. The tolerance rate was 92.4% vs. 65.5% between the sedated and unsedated group, respectively. 95.5% patients in the sedated group and 72.1% patients in the unsedated group chose the same endoscopy procedure for repeat examination. The survey data from endoscopists suggested the sedated procedure was more comfortable but less safe than the unsedated procedure (P<0.01). In China, unsedated GI endoscopy is now widely accepted by the majority of patients due to low cost and safety. Compared to unsedated GI endoscopy, sedated GI endoscopy is less painful, but more expensive and less safe. With the rapid improvement of people's living standard and the reliability of sedation technology, we expect sedated GI endoscopy will be gradually accepted by more patients.

Unsedated versus sedated gastrointestinal endoscopy: a questionnaire investigation in Wuhan, central China / 华中科技大学学报（医学）（英德文版）

National data show that in China mainland unsedated gastrointestinal (GI) endoscopy has been applied in most hospitals for clinical examination, while sedated GI endoscopy is only performed in some hospitals. The purpose of this study was to compare sedated versus unsedated GI endoscopy regarding cost, safety, degree of comfort, tolerance level and overall satisfaction of patients over a 6-month period investigation. From March to September 2011, a questionnaire survey was performed on 1800 patients and 30 physicians at Zhongnan Hospital of Wuhan University and Wuhan General Hospital of Guangzhou Military Command. The patients fell into two groups according to their own decisions: the unsedated group (n=1000) and the sedated group (n=800). After examination, the patients and the physicians were required to fill in a questionnaire form. All the data were analyzed statistically. The results showed that the main factors the patients took for consideration between sedated and unsedated procedures included economy, comfort and safety. The income levels between the sedated and unsedated groups showed significant difference (P<0.01). Most patients in the unsedated group had lower income and were covered by less medical insurance. The tolerance rate was 92.4% vs. 65.5% between the sedated and unsedated group, respectively. 95.5% patients in the sedated group and 72.1% patients in the unsedated group chose the same endoscopy procedure for repeat examination. The survey data from endoscopists suggested the sedated procedure was more comfortable but less safe than the unsedated procedure (P<0.01). In China, unsedated GI endoscopy is now widely accepted by the majority of patients due to low cost and safety. Compared to unsedated GI endoscopy, sedated GI endoscopy is less painful, but more expensive and less safe. With the rapid improvement of people's living standard and the reliability of sedation technology, we expect sedated GI endoscopy will be gradually accepted by more patients.

Screening and Identification of The Proteins Interacting With NLS-RARα Protein / 生物化学与生物物理进展

Acute promyelocytic leukemia (APL) is characterized by the generation of the prototypic promyelocytic leukemia-retinoicacid receptor alpha (PML-RARα), an oncogenic fusion protein due to chromosomal translocation. In a human myeloid cell line,PML-RARα is cleaved by neutrophil elastase (NE) to produce the mutational PML [nuclear localization signal (NLS) deletion andRARα (NLS-RARα, containing NLS of PML), both of which may play an important role in APL pathogenesis. The yeast two-hybridtechnique was used to screen the intracellular proteins interacting with NLS-RARα, which may be involved in NLS-RARα signaling. The NLS-RARα coding sequence was amplified by polymerase chain reaction method and was cloned into the bait plasmid pGBKT7vector, which, after the confirmation by sequencing, was transformed into yeast AH109 and the subsequent expression of bait plasmidwas proved by Western-blot. The transformed yeast AH109 was mated with yeast Y187 (containing leukemia cDNA library plasmidspACT2) in medium. Diploid yeast was plated on synthetic dropout nutrient medium containing X-α-gal for screening. After beingreintroduced into yeast AH109 and sequenced to verify the expression of ORF, eight positive colonies were obtained, among whichonecontaining JTV-1 was cloned. The interaction between NLS-RARα and JTV-1 was further supported by indirect immunofluorescence,GST pull-down and co-immunoprecipitation, respectively. These findings brought some new clues for the further exploration ofNLS-RARα signaling to APL.

Rest tension-based characterization of isometric contractility of Bufo gastrocnemius ex vivo / 南方医科大学学报

<p><b>OBJECTIVE</b>To characterize the isometric contractility of Bufo gastrocnemius ex vivo in light of the rest tension.</p><p><b>METHODS</b>Bufo gastrocnemius treated with SOD inhibitor and ascorbate was stimulated electrically (12 V DC, 2 ms duration with a 2 s interval) to record the tension within 10 min. Weighted fitting to the relaxation curve of the tension below 90% of the peak tension with a mono-exponential model yielded the rest tension and relaxation rate.</p><p><b>RESULTS</b>The control gastrocnemius showed monotonic decrease of the rest tension, but treatment with SOD inhibitor and ascorbate resulted in a decrease of the rest tension followed by a fast increase within a 1.0 min contraction. The increase of the rest tension at 7.0 min of contraction of the treated muscle was significantly greater than that of the control muscle. The control muscle showed a monotonic decrease of the relaxation rate in 10 min, whereas treatment with SOD inhibitor and ascorbate produced increased relaxation rate followed by monotonic decrease till a plateau was reached. In the course of the 10 min recording, the relaxation rate of the treated muscle was lower than that of the control after the same duration of contraction.</p><p><b>CONCLUSION</b>Rest tension is a characteristic index to represent the skeletal muscle contractility.</p>

Effects of ascorbic acid on relaxation of ex vivo Bufo gastrocnemius during sustained isometric contraction / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of ascorbic acid (VC) on relaxation of ex vivo Bufo gastrocnemius during sustained isometric contraction.</p><p><b>METHODS</b>Dynamic tension of the muscle was recorded under constant voltage stimulation within 7.0 min at 2 s intervals. The rest tension and relaxation rate of the muscle was obtained by weighted fitting to the relaxation process of tension <90% of its peak with a mono-exponential model to characterize the muscular relaxation.</p><p><b>RESULTS</b>VC at 2.0 mmol/L alone or in combination with the inhibitors of the antixoidation enzymes (surperoxide dismutase, glutathione peroxidase and catalase) resulted in negligible alterations in the muscular relaxation kinetics. VC combined with the inhibitor of surperoxide dismutase resulted in significantly lowered relaxation rate while increased rest tension, but VC with the inhibitor of either catalase or glutathione peroxidase showed negligible action. VC combined with the inhibitors of all the 3 enzymes also caused significant effect on the muscular relaxation kinetics, which was similar the effect of VC with superoxide dismutase inhibitor.</p><p><b>CONCLUSION</b>VC at high concentration may result in oxidative toxicity to the biological system rich in transitional metal ion complexes but with low antioxidation capacity by causing superoxide-mediated oxidative damages.</p>

Correlation of serum arylesterase activity on phenylacetate estimated by the integrated method to common classical biochemical indexes of liver damage / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The correlation of serum arylesterase (PON1) activity on phenylacetate determined by an integrated method to classical biochemical indexes of liver damage was investigated for the use of PON1 activity to evaluate liver damage. PON1 reaction curve as absorbance at 270 nm for 0.20 mmol/L phenylacetate hydrolysis was analyzed by the integrated method to determine maximal PON1 reaction rate. Classical biochemical indexes of liver damage were determined routinely. The 95% confidence threshold of PON1 activity in sera from healthy individuals was 2.12 mkat/L [(4.73+/-1.31) mkat/L, n=105]. PON1 activity in clinical sera was closely correlated to serum albumin, total protein and the ratio of albumin to globulins, but was weakly correlated to both direct and total bilirubin in serum. There were no correlations of PON1 activity to gamma-glutamyltransferase, alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase. Among 127 clinical sera with PON1 activity>2.12 mkat/L, there were 92% healthy individuals examined by albumin, 90% healthy individuals examined by total protein, 88% healthy individuals examined by total bilirubin, 86% healthy individuals examined by direct bilirubin and 64% healthy individuals examined by the ratio of albumin to globulins, respectively. In each group of healthy individuals judged by classical biochemical indexes of close correlation to PON1 activity, percentage of healthy individuals examined by PON1 activity was always >80%. These results suggested PON1 activity on phenylacetate estimated by the integrated method was also suitable for the evaluation of liver damage.

A new linearly-combined bi-exponential model for kinetic analysis of the isometric relaxation process of Bufo gastrocnemius under electric stimulation in vitro / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

There was a slow-relaxing tail of skeletal muscles in vitro upon the inhibition of Ca(2+)-pump by cyclopiazonic acid (CPA). Herein, a new linearly-combined bi-exponential model to resolve this slow-relaxing tail from the fast-relaxing phase was investigated for kinetic analysis of the isometric relaxation process of Bufo gastrocnemius in vitro, in comparison to the single exponential model and the classical bi-exponential model. During repetitive stimulations at a 2-s interval by square pulses of a 2-ms duration at 12 V direct currency (DC), the isometric tension of Bufo gastrocnemius was recorded at 100 Hz. The relaxation curve with tensions falling from 90% of the peak to the 15th datum before next stimulation was analyzed by three exponential models using a program in MATLAB 6.5. Both the goodness of fit and the distribution of the residuals for the best fitting supported the comparable validity of this new bi-exponential model for kinetic analysis of the relaxation process of the control muscles. After CPA treatment, however, this new bi-exponential model showed an obvious statistical superiority for kinetic analysis of the muscle relaxation process, and it gave the estimated rest tension consistent to that by experimentation, whereas both the classical bi-exponential model and the single exponential model gave biased rest tensions. Moreover, after the treatment of muscles by CPA, both the single exponential model and the classical bi-exponential model yielded lowered relaxation rates, nevertheless, this new bi-exponential model had relaxation rates of negligible changes except much higher rest tensions. These results suggest that this novel linearly-combined bi-exponential model is desirable for kinetic analysis of the relaxation process of muscles with altered Ca(2+)-pumping activity.

The Certification of HONcode and Moral Norms of Domestic Medicine and Health Websites / 中华医学教育探索杂志

This paper gives a brief introduction of the moral norms of medicine & health websites,HONcode,and its certification in international and domestic medicine & health websites.To build a standard for healthy and clear online data environment,it was suggested that the ideas of HONcode be applied to the quality control of domestic medicine & health websites.

Evaluation of a kinetic uricase method for serum uric acid assay by predicting background absorbance of uricase reaction solution with an integrated method / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

A patented kinetic uricase method was evaluated for serum uric acid assay. Initial absorbance of the reaction mixture before uricase action (A(0)) was obtained by correcting the absorbance at 293 nm measured before the addition of uricase solution, and background absorbance (A(b)) was predicted by an integrated method. Uric acid concentration in reaction solution was calculated from A, the difference between A(0) and A(b), using the absorptivity preset for uric acid. This kinetic uricase method exhibited CV<4.3% and recovery of 100%. Lipids, bilirubin, hemoglobin, ascorbic acid, reduced glutathione and xanthine <0.32 mmol/L in serum had no significant effects. A linearly responded to 1.2 to 37.5 micromol/L uric acid in reaction solution containing 15 microl serum. The slope of linear response was consistent with the absorptivity preset for uric acid while the intercept was consistent with that for serum alone. Uric acid concentrations in clinic sera by different uricase methods positively correlated to each other. By Bland-Altman analysis, this kinetic uricase method accorded with that by quantifying the total change of UV absorbance on the completion of uricase reaction. These results demonstrated that this kinetic uricase method is reliable for serum uric acid assay with enhanced resistance to both xanthine and other common errors, wider range of linear response and much lower cost.