BACKGROUND: Streptococcus mutans (S. mutans) is generally considered to be the principal aetiological agent for dental caries, thrS gene may relate to the virulence of S. mutans involved in the adherence, acidogenicity and acidodurance.OBJECTIVE: To investigate the conservation status of the thrS gene of S. mutans and to construct the homologous recombinant plasmid.METHODS: Southern Blot was used to analyze the distdbuUon of thrS gene in S. mutans. The upstream and downstream sequences of thrS gene were cloned respectively into multiple cloning sites of suicide plasmid pFW5 to construct the recombinant plasmid,RESULTS AND CONCLUSION: The thrS gene was conserved in 6 strains of S. mutans in this test. By PCR analysis and enzyme digesting, it was confirmed that S. mutans thrS gene homologous recombinant plasmid was successfully constructed,which can be used in future research of construction of thrS -negative mutans of S. mutans strain UA159.

Objective To evaluate and compare the safety and advantage of different kinds of electrode system (monopolar and plasmakinetic techniques) in transcervical resection of myoma (TCRM). Methods A total of 60 patients undergoing TCRM were enrolled. Serum sodium (Na~+), chlorine (Cl~-), potassium (K+) and glucose (Glu) were measured before and after the operation. Meanwhile, the operation time, absorption volume and bleeding volume were also recorded after the operation. Results ① There were significant decreases in Na~+, Cl~-, K~+ and Glu concentrations in the monopolar group (P<0.05), but Glu increased significantly (P<0.05). Na~+, Cl~-, K~+ and Glu concentrations in plasmakinetic group, however, did not change significantly before and after the operation (P>0.05). ② After the operation, there were significant differences between the two groups in Na~+, Cl~- and Glu changes (P<0.05). The absorption volume and volume of bleeding during the operation were increased in monopolar group compared with those in plasmakinetic group (P<0.05). ③ In monopolar group, Na~+, Cl~- and Glu concentrations, the operation time, absorption volume and volume of bleeding were significantly higher in patients with type Ⅱ myoma than in those with type Ⅰ and 0. In plasmakinetic group, the operation time, absorption volume and volume of bleeding were significantly increased in type Ⅱ myoma patients. No significant difference was observed of Na~+, Cl~- and Glu concentrations between patients with the three types of myoma (P>0.05). Conclusion Plasmakinetic technique is superior to monopolar one in that it does not cause obvious changes in blood electrolytes and glucose and there is less bleeding during the operation. Myoma type has a greater effect on the absorption volume, operation time and volume of bleeding during operation, which are increased in type Ⅱ myoma than in type 0 and 1.

Objective:To knock the phospho-sugar mutase gene (psm) out of the genome of S. mutans strain UA159 and to construct the mutant will lay a foundation for the study of the function of the psm. Methods:Two upstream and downstream DNA sequences of the psm were selected and cloned respectively into multiple cloning sites I and II of suicide plasmid pFW5 to construct the recombinant plasmid which was confirmed by enzyme digesting and sequencing. The recombinant plasmid was transformed into S. mutans UA159 by natural transformation and antibiotic was used to screen the positive transformants. According to the principle of homologous recombination, allelic exchange between the recombinant plasmid and S. mutans UA159 was achieved. Results:By PCR analysis and sequencing, it was confirmed that the psm of S. mutans UA159 was substituted for resistant gene of spectinomycin. Conclusion: The psm-negative mutants of S. mutans UA159 is successfully constructed.

Objective To define a parameter of autologous arteriovenous fistula stenosis that limits the fistula function for hemodialysis in our country.Methods Retrospectively study the doppler ultrasound of patients who accepted the percutaneous transluminal angioplasty (PTA) therapy due to autogenous arteriovenous fistula dysfunction;identify the least diameter of the fistula vein and compare it with the corresponding data of well-functioned fistula.Determine which absolute diameter constitutes a hemodynamically significant stenosis in a radioeephalic autologous arteriovenous fistula by receiver operating characteristic curve (ROC curve).Result Forty-two patients were enrolled in the study.The average age of those patients was 54.63±2.44 years old.Twenty-one patients were female.Twenty-six fistula located on the left arm.The minimal diameter of the dysfunction fistula averaged 1.57±0.07 mm,while the average forearm fistula vein diameter was 4.04±0.23 mm,significantly smaller than those in the compare group-an average minimal fistula vein diameter of 3.34±0.11 mm and a forearm vein diameter of 5.36(4.52,6.45) mm (P ＜ 0.05).The control group contained sixty-eight patients.The average age of those patients was 52.56±2.00 years old.Thirty-one patients were female.Forty-nine fistula located on the left arm.It was quiet appropriate in using minimal diameter of the fistula vein to indicate the dysfunction istula with an under-curve area of 0.979,95％C1 0.959-0.998.The under-curve area would be at the largest level when meeting the cutoff point at 2.40mm,in which it could achieve the area of 0.853.Conclusions The minimal diameter of the dysfunction wrist autogenous arteriovenous fistula was much smaller than the functioned ones.Minimal diameter of the fistula vein may serve as an effective parameter in detecting dysfunction fistula.

Objective To evaluate the value of MRI in qualitative and quantitative diagnosis of bone marrow involvement in patients with lymphoma. Methods 28 diagnosed lymphoma with bone marrow infiltration and 31 healthy spines as controls were included.MRI performance and the signal intensity ratio on T1WI (SIR1) of the spine bone marrow and cerebrospinal fluid were analyzed and statistical analyses were performed.Results Qualitative diagnosis among these patients,was shown than MRI results indicated that 27 cases had abnormal signal. The sensitivity of MRI was 96.4 ％. There were four main patterns of marrow infiltration in MRI,containing nodular pattern 21.4 ％ (6/28),scattered pattern 53.6 ％ (15/28),mottled pattern 14.3 ％ (4/28) and uniform pattern 7.1％ (2/28) respectively.By quantitative diagnosis the SIR1 of study group (1.251±0.253) was apparently lower than that in the control group (2.625±0.434) with statistical significance (t =15.022,P ＜ 0.001).The results of multiple comparisons showed that the SIR1 of mild degree (1.390±0.172),moderate degree (0.982±0.790) and severe degree (0.908±0.122) patients with lymphoma compared with the normal controls had significant differences (all P =0.000),and difference between mild and moderate degree had statistical significance (LSD,P =0.012),so did the difference between mild and severe degree (LSD,P =0.025).However,no significant difference could be seen between moderate and severe degree (LSD, P =0.757). Positive linear correlation was existed between the persentages of SIR1 and tumor cells in bone marrow (r =-0.765, P ＜ 0.001). Conclusion As a noninvasive and direct-viewing technique, MRI presents a global view of bone marrow with high sensitivity in detecting bone marrow involvement in lymphoma. To a certain extent, it could be possible to estimate the infiltration degree and evaluation of the tumor burden in bone marrow by quantitative measurement of MRI.

Objective To evaluate spectral CT imaging in characterizing the pathological type and the differentiation of gastric cancer.Methods Ninety-one patients diagnosed of gastric cancer were retrospectively analyzed.Patients were all underwent triple-phase enhanced scan using single source dualenergy CT on gemstone spectral imaging(GSI) mode.Three types of images were reconstructed for analysis:the water concentration (WC),iodine concentration (IC),and normalized iodine concentration (NIC).The patients were divided into groups of mucinous carcinoma (MUC),including mucinous adenocarcinoma and signet ring cell carcinoma,and non-mucinous gastric carcinoma (non-MUC).Independent-samples t test was used for statistical analysis.Results There were 24 patients of MUC and 67 patients of non-MUC.The IC and NIC of the non-MUC were significantly higher than the MUC in vein phase (VP) and in parenchymal phase (PP) [(21.33 ±6.31) × 100 vs (16.94 ±6.13) × 100 μg/ml,0.55 ±0.17 vs 0.42 ±0.14 in VP,and(20.65 ±5.49) × 100 vs (18.07 ±4.51) × 100 μg/ml,0.72 ±0.20 vs 0.57 ±0.12 in PP,respectively t =-2.948,-3.362,-2.261,-4.326,P ＜0.05].The IC and NIC of the signet ring cell carcinoma were statistically higher than those of the mucinous adenocarcinoma [(19.36 ± 4.75) × 100 vs (12.10 ±5.92) ×100μg/ml,0.49 ± 0.09 vs0.28±0.11 in VP,and (19.88±3.28) ×100 vs (14.45±4.62) ×100 μg/ml,0.63 ±0.08 vs 0.47 ±0.11 in PP,respectively t =3.253,5.180,3.339,3.850,P ＜0.01].For the poorly differentiated and well /moderately differentiated adenocarcinoma,the IC and NIC of the former were higher than those of the latter in VP and PP [(23.48 ±6.49) × 100 vs (18.98 ±5.26) × 100 μg/ml,0.61±0.16vs0.48±0.15 in VP,and (22.95±5.51) ×100 vs (18.28±4.47) ×100 μg/ml,0.81 ± 0.21 vs 0.63 ± 0.15 in PP,respectively t =3.098,3.249,3.766,4.117,P ＜ 0.01].The between-group differences of WC,IC and NIC in artery phase were no significant (P ＞ 0.05).Conclusions Different pathological types could determine different IC.The spectral CT imaging may be helpful for characterizing the pathological type of gastric cancer.

OBJECTIVETo compare the effects between mild moxibustion and specific electromagnetic spectrum therapy apparatus (TDP) for obsolete collateral ligament injury of interphalangeal joints.

METHODSSixty patients were randomly divided into a mild moxibustion group and a TDP group, 30 cases in each one. In the mild moxibustion group, pure moxa sticks were used at the affected digital joints locally for 20-30 min a time. In the TDP group, TDP was applied at the affected digital joints locally for 20-30 min a time. The treatment was given once a day for two courses, and 10-day treatment was made into a course. Visual analogue scale (VAS) for pain, swelling degree of the affected digital joints before and after treatment were observed and the clinical efficacy and safety were evaluated in the two groups.

RESULTSThe excellent rate was 56.7% (17/30) and the excellent and, good rate was 83.4% (25/30) in the mild moxibustion group,which were better than 36.7% (11/30) and 76.7% (23/30) in the TDP group respectively (both P < 0.01). After treatment the score of VAS and digital joints swelling degree were improved than those before treatment in the two groups (P < 0.01, P < 0.05), and the improvements of the mild moxibustion group were better than those of the TDP group (P < 0.01, P < 0.05).

CONCLUSIONMild moxibustion can apparently relieve the painful and swelling degree of obsolete collateral ligament injury of interphalangeal joints, which is superior to TDP.

Acupuncture Points ; Adolescent ; Adult ; Collateral Ligaments ; injuries ; Electromagnetic Radiation ; Female ; Humans ; Joint Diseases ; therapy ; Magnetic Field Therapy ; Male ; Moxibustion ; Pain Measurement ; Young Adult

Objective To investigate the protection effect of inferior vena cava filter on pulmonary embolism in patients with deep venous thrombosis(DVT) of lower extremities. Methods Inferior vena cava filters were placed in 55 patients with DVT. Simon Nitiol filter(SNF) was used in 25 cases,Trap Ease filter(TEF) in 13 cases and Antheor Temporal filter(ATF) in 17 cases.10 patients with DVT were treated by non operation therapy,45 patients by operation and transluminal angioplasties.Whether patients occurred pulmonary embolism was observed clinically,and the form and site of SNF and TEF were monitored by periodic fluoroscopy . Results Inferior vena cava filter was placed successfully in all patients.Symptoms and signs of DVT disappeared in all the patients after treatment . None of the putients occurred pulmonary embolism in this series. One case occurred inferior vena cava thrombolism in 16 months after SNF placement. Thrombus attached to ATF after the ATF taking off from inferior vena cava was found in 17 cases.Conclusions Inferior vena cava filter placement is a simple, safe and efficient method to prevent pulmonary embolism in a short period.But its long term complications should be considered and investigated.

Object To investigate the maturity status of the cephalic vein when the native arteriovenous fistula matures and set up indicators of a matured native arteriovenous fistula.Methods The diameter,flow rate and wall thickness of the cephalic vein were prospectively measured by Doppler ultrasound after the native fistula was created.Mature judgment was done by skilled nurses depending on their experience before the fistula was punctured.The ultrasound data was marked as proposed mature at the same time.After three times dialysis,if blood flow was fluent and complications such as prolonged bleeding time and hematoma were absent,fistula mature was confirmed.Results Thirty-one patients were admitted to the study,then fistula were matured.The average age of those patients was (52.93±3.21) years old.Thirteen patients were female.Twenty two fistula located on the left arm.Thirteen of the patients were diabetic nephropathy.The average diameter of cephalic vein was increased from (3.10±0.11) mm before surgery to (4.74±0.16) mm when the fistula was matured,though it was still smaller than 6 mm which K/DOQI guideline had recommended (P ＜ 0.05).The average mature period was (57.10±3.21) days.The matured fistula had an average high flow rate of (569.76±48.34) ml/min and wall thickness of (0.95±0.04) mm.The one-side 95％ credibility interval of the diameter,flow rate and wall thickness of cephalic vein was 4.44 mm,486.37 ml/min and 0.67 mm,respectively.Conclusions The diameter of cephalic vein in a matured native arteriovenous fistula in our study was significantly smaller than 6 mm which K/DOQI guideline had recommended.The indicators of native arteriovenous fistula mature in our country may different from abroad.

Objective To explore the protective effects and the mechanisms of peritoneal dialysis (PD) on multiple organs induced by acute organophosphoms pesticide poisoning(AOPP)in order to get a scientific basis for the application of PD to treat AOPP patients. Method The model of AOPP rabbits was made by intragastric administration of 25 mg/kg(0.5LD50)40% omethoate, and the symptoms of poisoning such as myosis, salivating and muscular tremor were observed. Eighteen male Japanese rabbits were randomly divided into control group and peritoneal dialysis group (PD group). Pralidoxime chloride and atropine were given by intra-muscular injection to rabbits of control group (re = 9). Rabbits of PD group ( n = 9) had a tube inserted into peritoneal cavity and peritoneal dialysis was given for 10 times after administration of pralidoxim chloride and atropine. Serum TNF-α,CK-MB (M.B. isoerizyme of creatine kinase), ALT, creatinine, and amylase were observed dynamically. The dialysate of peritoneal dialysis was remained in the peritoneal cavity for testing the nature of intoxicant by using Varian 3900/ Saturn 2100T GC/MS device. All data were analyzed with SPSS version 12.0 software. Statistical comparison between two groups was carried out by using student t-test and analysis of variance(ANOVA) followed by Dunnett-ttests before and after intoxication. The pearson correlation analysis was used for determination of the relationship between TNF-α and other biomarkers. Results After intoxication, serum TNF-α, CK-MB, ALT and amylase increased except creatinine, but the serum levels of those biomarkers in PD group were significantly lower than those in control group.The level of TNF-a had positive correlations with CK-MB ( r = 0.470), ALT ( r = 0.649), and amylase ( r = 0.517). The omethoate was detected in the dialysate of peritoneal dialysis. Conclusions Organophosphorus pesticides can lead the cardiac muscle, liver, kidney and pancreas to the injury through several mechanisms,and the inflammatory mediators play important role in the development of MODS induced by AOPP. Peritoneal dialysis can clean up intoxicants slowly and continuously and in turn lower down the level of inflammatory mediators resulted in protecting multiple organs from AOPP.