Objective In a large-scale clinical medical examination, A2 type best multiple-choice test questions to the same knowledge were used respectively in simple and complex form, to compare the difficulty and discrimination indices of the two forms of test questions and provide evidence to the improve-ment of clinical medical examination. Method In a large-scale clinical medical examination more than 4000 candidates participated, and 20 questions to different knowledge points were randomly selected and used in the examination respectively in simple and complex A2 type best multiple-choice test questions. The difficulty and discrimination indices of the two forms of test questions were compared. Results The average difficulty coefficient of the 20 simple test questions (65.5 words per question in average) is 0.6829, and the average discriminative powers are 0.2675 and 0.2579 respectively using identification index method and point biserial correlation method. The average difficulty coefficient of the 20 complex test ques-tions (135.5 words per question in average) is 0.7095, and the average discriminative powers are 0.3065 and 0.2967 respectively using identification index method and point biserial correlation method. Conclusion To the same knowledge points, the average difficulty of complex A2 type best multiple-choice test questions is slightly lower than the simple ones, while the average discriminative power is increased in the complex questions. The complex A2 type test questions are of higher quality and more in line with the requirements of the medical entrance examination, medical education and examination reform.

OBJECTIVE:To investigate the effects of total paeony glycoside (TPG) on the expression of tumor suppressor gene in lung cancer model rats. METHODS:90 rats were randomly divided into normal group,model group,positive control group [cyclophosphamide,50 mg/(kg·d)] and TPG low-dose,medium-dose and high-dose groups [50,100,200 mg/(kg·d)] with 15 rates in each group. Except for normal group,other groups were given disposable infusion of carcinogenic iodized oil via left lobe bronchus to induce lung cancer model. After modeling,those groups were given relevant medicine intravenously from Monday to Friday,while normal group and model group were given constant volume of normal saline intravenously for consecutive 16 weeks. The expression of multidrug resistance associated protein(MRP),human multidrug resistance gene(MDR1),P21 and P16 mRNA in lung tissue of rats were determined by RT-PCR;the expression of P53 protein in lung cancer tissue was determined by IHC method.The rate of positive expression was calculated,and pathological change of lung tissue was observed. RESULTS:Com-pared with normal group,the expression of MRP,MDR1,P21,P16 mRNA and P53 protein(positive rate of 66.67%)in lung tis-sue was increased significantly in model group (P<0.05);compared with model group,the expression of MRP,MDR1,P21, P16 mRNA and P53 protein (positive rate of 46.67%,46.67%,40.00%,13.33%) decreased in positive control group,TPG low-dose,medium-dose and high-dose groups in dose-dependent manner,and the decrease of TPG medium-dose and high-dose groups were more significant than that of positive control group (P<0.05);there was statistical significance in above indexes among TPG groups(P<0.05). CONCLUSIONS:TPG could inhibit the expression of MRP,MDR1,P21,P16 gene and P53 pro-tein in lung cancer model rats significantly.

Objective To explore the risk association of ABCA1-V771M polymorphism with coronary heart disease (CHD) in Hart nationality in Northwest of China. Methods With case-control study, ABCA1-V771M polymorphism was detected in 204 unrelated Hart nationality people in Northwest of China, and all the subjects by coronary angiography were grouped into 106 cases and 98 controls. The genotypes and alleles frequency distribution of ABCA1-V771M polymorphisms were analyzed by PCR-RFLP analysis, and the clinical statistics of serum lipids were compared and its effects of ABCA1-V771M polymorphism on the plasma lipid levels and coronary atherosclerotic heart disease were analyzed. Results The genotypic frequencies of ABCA1-V771M polymorphism matched well under Hardy-Weinberg equilibrium (P>0.05), V and M allelic frequencies were 33.3% and 66.7%. In comparison with VV+VM genotype carriers, MM genotypes carriers had much lower plasma levels of HDL-C (P<0. 001) and much higher plasma levels of TG (P<0. 05). M allelic frequency in CHD group was significantly higher than V allelic frequency (P<0. 05). M allele was related with more severity of atherosclerosis in the coronary artery than V allele (P<0.05). However, there was no obvious difference in the incidence of AMI among carriers with three genotypes of ABCA1-V771M polymorphism (P>0.05). Conclusion ABCA1-V771M polymorphism was not only associated with the plasma levels of HDL-C and TG, but also related to the susceptibility and severity of coronary atheroselerotic heart disease. Moreover, M771 allele appeared to be atherogenie among Han population in Northwest of China.

OBJECTIVE To screen for a simple,accurate and no-traumatic detecting method of Helicobacter pylori(Hp). METHODS Hp in gastric fluid and dental plaque was detected with fluorescent antibody method,bacterial culture,urease test and Hp diagnosis card at the same time in 62 cases with gastric and duodenal disease.The gather of gastric fluid applied the capsule method. RESULTS The detective rates of Hp in gastric fluid by four methods were 85.5%,9.7%,61.3%,and 56.5%;the detective rates of Hp in dental plaque by four methods were 88.7%,25.8%,69.4%,and 90.3%,respectively. CONCLUSIONS Fluorescent antibody method combined with capsule method detecting Hp in gastric fluid is specific,sensitive and without trauma.Thus,it is suggested to be used clinically.

ObjectiveTo investigate the feasibility of using pulse oximetry plethysmographic waveform (POP) to identify the restoration of spontaneous circulation (ROSC) during cardiopulmonary resuscitation (CPR).Methods An observational research was conducted. A porcine model of ventricular fibrillation (VF) arrest was reproduced. After 3 minutes of untreated VF, animals received CPR according to the latest CPR guidelines, providing chest compressions to a depth of 5 cm with a rate of 105 compressions per minute and instantaneous mechanical ventilation. After 2 minutes of CPR, animals were defibrillated with 100 J biphasic, followed by continuous chest compressions. Data of hemodynamic parameters, partial pressure of end-tidal carbon dioxide (PETCO2) and POP were collected. The change in POP was observed, and the characteristics of changes of the waves were recorded during the peri-CPR period using the time and frequency domain methods.Results VF was successfully induced in 6 pigs, except 1 death in anesthesia induction period.① After VF, invasive blood pressure waveform and POP of the animals disappeared. PETCO2 was (18.83±2.71) mmHg (1 mmHg=0.133 kPa), and diastolic arterial pressure was (23.83±5.49) mmHg in compression stage. Animals attained ROSC within 1 minute after defibrillation, with PETCO2 [(51.83±9.35) mmHg] and diastolic arterial pressure [(100.67±10.97) mmHg] elevated significantly compared with that of compression stage (t1 = 8.737,t2 = 25.860, bothP = 0.000), with appearance of arterial blood pressure waveform.② Characteristic changes in POP were found in all experimental animals. During the stages of induced VF, compression, ROSC, and compression termination, POP showed characteristic waveform changes. POP showed disappearance of waveform, regular compression wave, fluctuation hybrid and stable pulse wave in time domain method; while in the frequency domain method waveform disappearance, single peak of compression, double or fusion peak and single peak of pulse were observed.Conclusion Analysis of POP using time and frequency domain methods could not only quickly detect cardiac arrest, but also show a role as a feasible, non-invasive marker of ROSC during CPR.

OBJECTIVETo investigate the effect of diclofenac on the expression of Kv1.3 and Kir2.1 channels in human macrophages and the membrane potential and foaming process of the macrophages.

METHODSThe effect of diclofenac on the expression of Kv1.3 and Kir2.1 channels in cultured human monocyte-derived macrophages was investigated using real-time RT-PCR and Western blotting, and its effect on the membrane potential was analyzed with optical mapping of the membrane potential with voltage-sensitive dyes. The ratio of cholesterol ester (CE) in the macrophages following intake of oxidized low-density lipoprotein (OxLDL) was analyzed by an enzymatic fluorometric method.

RESULTSThe expression of Kv1.3 and Kir2.1 channels in the macrophages were down-regulated by diclofenac (1.5 µmol/L and 15 µmol/L). Compared with those in the control group, Kv1.3 mRNA expression was reduced by over 80% and 90% (P<0.05), and Kir2.1 mRNA by over 20% and 30% (P>0.05), respectively; both their protein expression was reduced by over 10% and 60% with a dose- dependent effect (P<0.05). Diclofenac at the two doses dose-dependently reduced the surface fluorescence intensity of the macrophage, and the membrane potential was decreased by 28% and 54%, respectively (P<0.05). Incubation of the macrophages with 30 mg/L OxLDL for 60 h caused an obvious enlargement of the cell volume and deposition of numerous lipid granules in cytoplasm, resulting also in a CE/TC ratio over 50% (P<0.05). Diclofenac at 1.5 and 15 µmol/L both significantly decreased the CE/TC ratio to (23.624∓3.34)% and (13.601∓2.916)% (P<0.05), respectively, but this effect did not show a dose-response relationship (P>0.05).

CONCLUSIONDiclofenac can significant down-regulate the expression of Kv1.3 and Kir2.1 channels in human macrophages, lower their membrane potential and inhibit the process of foam cell formation.

Cells, Cultured ; Diclofenac ; pharmacology ; Foam Cells ; cytology ; drug effects ; Humans ; Kv1.3 Potassium Channel ; metabolism ; Macrophages ; drug effects ; metabolism ; physiology ; Membrane Potentials ; drug effects ; Potassium Channels, Inwardly Rectifying ; metabolism

Medical licensing examination is a well-accepted form to authenticate physicians' qualification for practicing in most countries. Assessment of medical humanities is of great importance in medical licensing examination. In this study, the medical humanity evaluation, including contents, forms, scores and proportion of the scores of the examinations, in the medical licensing examination and the empirical research examination of segmental physician examination in China and the United States was compared by analyzing literatures and comparative approach, with the clinical examinations as examples. Results showed that contents and proportion of the scores of medical humanities in the two countries were basically the same, but there were fewer stations in current medical licensing examination in China and improvement should be made in the examination form. The feasibility of standard patients in China's medical licensing examination should be further explored, so as to make full use of the guiding role of medical licensing examination in medical education.

OBJECTIVETo provide further pathogenic evidence of Granulocytic ehrlichia infection in China.

METHODSSpecific primers derived from 444-Epank gene were used to amplify Granulocytic ehrlichia DNA from specimens of ticks, animals and human blood. PCR products of ticks were cloned and sequenced.

RESULTS444 bp specific DNA fragments were amplified from 2 of 62 pools of Ixodes persulcatus collected from Heilongjiang province and 1 of 129 blood specimens from forest workers in Inner Mongolia. Eight animal specimens were negative. PCR products from ticks were then cloned and sequenced. It differed at 23 positions in comparison to American strain (AF047897) with 94.9% homology. The homology of deduced ammonia was 88.44%.

CONCLUSIONOur findings further confirmed that Granulocytic ehrlichia infection did exist in China.

DNA, Bacterial ; analysis ; Ehrlichia ; classification ; genetics ; isolation & purification ; Ehrlichiosis ; microbiology ; Genes, Bacterial ; Humans ; Phylogeny ; Polymerase Chain Reaction ; Sequence Analysis, DNA

OBJECTIVETo identify the gene mutation in a Chinese family with congenital long QT syndrome (LQTS) and predict the changes of the secondary structure of the protein.

METHODSPolymerase chain reaction and DNA sequencing were used to screen for KCNH2 mutation in the proband. After the mutation was identified, KCNH2 gene of the family members was screened by multiplex PCR with site-specific primers. Network analysis software was used to predict the secondary structure of the KCNH2 protein.

RESULTSA novel heterozygous missense mutation of F463L(GenBank accession no.EU218526) located at the transmembrane domain S2 of KCNH2 was detected. The mutation did not result in the change of the transmembrane domain, but altered the hydrophobicity and secondary structure of the protein.

CONCLUSIONThe novel mutation identified in this study has enriched the GenBank data of ion channel gene mutation in LQTS. The changes of the secondary structure caused by the gene mutation were analyzed by Mfold and TMHMM software, which may help to understand LQTS.

Adult ; Amino Acid Sequence ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; DNA Mutational Analysis ; ERG1 Potassium Channel ; Ether-A-Go-Go Potassium Channels ; chemistry ; genetics ; Female ; Humans ; Hydrophobic and Hydrophilic Interactions ; Long QT Syndrome ; congenital ; genetics ; Male ; Molecular Sequence Data ; Mutation, Missense ; Pedigree ; Protein Structure, Secondary ; Protein Structure, Tertiary

OBJECTIVE: To observe the toxicokinetic parameters, absorption characteristics and pathomorphological damage in different parts of the gastrointestinal tract of rats poisoned with different doses of diquat (DQ). METHODS: Ninety-six healthy male Wistar rats were randomly divided into a control group (six rats) and low (115.5 mg/kg), medium (231.0 mg/kg) and high (346.5 mg/kg) dose DQ poisoning groups (thirty rats in each dose group), and then the poisoning groups were randomly divided into 5 subgroups according to the time after exposure (15 minutes and 1, 3, 12, 36 hours; six rats in each subgroup). All rats in the exposure groups were given a single dose of DQ by gavage. Rats in the control group was given the same amount of saline by gavage. The general condition of the rats was recorded. Blood was collected from the inner canthus of the eye at 3 time points in each subgroup, and rats were sacrificed after the third blood collection to obtain gastrointestinal specimens. DQ concentrations in plasma and tissues were determined by ultra-high performance liquid chromatography and mass spectrometry (UPHLC-MS), and the toxic concentration-time curves were plotted to calculate the toxicokinetic parameters; the morphological structure of the intestine was observed under light microscopy, and the villi height and crypt depth were determined and the ratio (V/C) was calculated. RESULTS: DQ was detected in the plasma of the rats in the low, medium and high dose groups 5 minutes after exposure. The time to maximum plasma concentration (Tmax) was (0.85±0.22), (0.75±0.25) and (0.25±0.00) hours, respectively. The trend of plasma DQ concentration over time was similar in the three dose groups, but the plasma DQ concentration increased again at 36 hours in the high dose group. In terms of DQ concentration in gastrointestinal tissues, the highest concentrations of DQ were found in the stomach and small intestine from 15 minutes to 1 hour and in the colon at 3 hours. By 36 hours after poisoning, the concentrations of DQ in all parts of the stomach and intestine in the low and medium dose groups had decreased to lower levels. Gastrointestinal tissue (except jejunum) DQ concentrations in the high dose group tended to increase from 12 hours. Higher doses of DQ were still detectable [gastric, duodenal, ileal and colonic DQ concentrations of 6 400.0 (1 232.5), 4 889.0 (6 070.5), 10 300.0 (3 565.0) and 1 835.0 (202.5) mg/kg respectively]. Light microscopic observation of morphological and histopathological changes in the intestine shows that acute damage to the stomach, duodenum and jejunum of rats was observed 15 minutes after each dose of DQ, pathological lesions were observed in the ileum and colon 1 hour after exposure, the most severe gastrointestinal injury occurred at 12 hours, significant reduction in villi height, significant increase in crypt depth and lowest V/C ratio in all segments of the small intestine, damage begins to diminish by 36-hour post-intoxication. At the same time, morphological and histopathological damage to the intestine of rats at all time points increased significantly with increasing doses of the toxin. CONCLUSIONS The absorption of DQ in the digestive tract is rapid, and all segments of the gastrointestinal tract may absorb DQ. The toxicokinetics of DQ-tainted rats at different times and doses have different characteristics. In terms of timing, gastrointestinal damage was seen at 15 minutes after DQ, and began to diminish at 36 hours. In terms of dose, Tmax was advanced with the increase of dose and the peak time was shorter. The damage to the digestive system of DQ is closely related to the dose and retention time of the poison exposure.
Animals ; Male ; Rats ; Diquat/toxicity* ; Gastrointestinal Diseases ; Intestines ; Poisons ; Rats, Wistar ; Toxicokinetics