One-Stage Repair of Adult Aortic Coarctation and Concomitant Cardiac Diseases: Ascending to Abdominal Aorta Extra-Anatomical Bypass Combined with Cardiac Surgery.

BACKGROUND: To evaluate one-stage repair with ascending to abdominal aorta extra-anatomical bypass combined with cardiac surgery for adult aortic coarctation (COA) concomitant with cardiac diseases. METHODS: Between February 2009 and September 2016, 24 consecutive patients (79.17% male, mean age 36.04±13.67years) with COA and concomitant cardiac diseases underwent one-stage repair (ascending to abdominal aorta extra-anatomical bypass combined with cardiac surgery). Two (2) patients who underwent off-pump coronary artery surgery combined with ascending to abdominal aorta bypass did not require cardiopulmonary bypass. Twenty-two (22) patients underwent one-stage repair under cardiopulmonary bypass. RESULTS: No in-hospital mortality was observed. There was a significant reduction in baseline systolic blood pressure from 159.80±23.58 to 127.0±6.86mmHg. Mean upper-lower limb blood gradient pressure decreased significantly from 37.80±8.73 to 11.47±2.12mmHg after surgery. Two (2) patients required prolonged mechanical ventilation for respiratory dysfunction. One patient needed temporary continuous renal replacement therapy. No re-exploration for bleeding and gastrointestinal complications was needed. There was no postoperative paraplegia or permanent neurological abnormalities. Grafts were patent for all patients and no graft-related complications were observed in the hospital. Median follow-up was 41.50 months (interquartile range [IQR] 16.75-64.50 months) and 6-year survival was 76.39%. Median number of antihypertensive drugs was 0 (IQR 0-1), which was a significant reduction compared with preoperative drugs (2, IQR 1-3). CONCLUSIONS: Ascending to abdominal extra-anatomical aorta bypass combined with cardiac surgery is a safe and effective one-stage repair technique for patients with COA concomitant with cardiac diseases.

Profiling of mRNA and long non-coding RNA of urothelial cancer in recipients after renal transplantation.

The molecular mechanism and signal transduction pathways involved in urothelial cancer (UC) after renal transplantation (RTx) remain unknown. In this study, we investigated the profiling of messenger RNA (mRNA) and long non-coding RNA (lncRNA) in RTx recipients with UC. The mRNA and lncRNA of six pairs of UC and corresponding normal urothelial tissues in RTx recipients were profiled using Arraystar Human lncRNA Microarray V3.0, which is designed for the global profiling of 26,109 coding transcripts and 30,586 lncRNAs. Quantitative real-time PCR (qRT-PCR) was used to validate the differentially expressed mRNAs and lncRNAs. Molecular function classification and biological process classification for the differentially expressed mRNAs were analyzed with Gene Ontology. The key pathways that were associated with UC after RTx were analyzed using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Compared to normal urothelial tissues, 1597 mRNAs were upregulated and 1032 mRNAs were downregulated in UC; 2107 lncRNAs were upregulated and 1794 lncRNAs were downregulated (greater than twofold). Further qRT-PCR analysis of mRNA and lncRNA expression showed well consistency with the data of microarray analysis. The expression of matrix metalloprotease (MMP)-3, MMP-10, MMP-12, and MMP-13 was significantly increased, while the expression of CD36 was decreased in UC after RTx. Co-expression analysis of lncRNAs and their nearby coding genes showed that lncRNAs may play critical roles in regulating nearby genes in the carcinogenesis of UC. Our results also suggest that peroxisome proliferator-activated receptor (PPAR) signaling may be involved in UC after RTx. Moreover, several cytokines and their receptors were also significantly upregulated in UC after RTx, suggesting that cytokines might be modulated and participated in the carcinogenesis of UC after RTx. We analyzed the potential molecular mechanism and pathways involved in the UC of RTx recipients. Our results revealed that several key regulatory pathways and lncRNAs play critical roles in the carcinogenesis of UC, and suggest that UC in RTx recipients may be more likely to invade and metastasis. However, the detailed functional analysis of these mechanisms should be further performed in the future.

Surgical management of aortic regurgitation secondary to Behcet's disease.

Background: Aortic regurgitation (AR) related to Behcet's disease (BD) is rare, but usually fatal. Perivalvular leakage (PVL) is high if AR related to BD treated with regular AVR. In this study, we report the surgical management of AR secondary to BD. Methods: Between September 2017 and April 2022, 38 patients with AR secondary to Behcet's disease had surgery in our center. 17 patients did not have a BD diagnosis before surgery, 2 of them were diagnosed during surgery and received Bentall procedure. The remaining 15 patients received conventional AVR. 21 patients were diagnosed as BD before surgery, all of them received modified Bentall procedures. All patients were followed up by regular outpatient visits, transthoracic echocardiogram and CT angiography were performed to evaluate the aorta and aortic valve. Results: Seventeen patients did not have a BD diagnosis at the time of surgery. Out of them, 15 patients received conventional AVR, and a total of 13 patients suffered PVL after surgery. Twenty-one patients had a BD diagnosis before surgery. They received modified Bentall procedures and IST and steroids were given both pre- and post-surgery. In this group treated with Bentall procedure no patient suffered PVL during follow up. Conclusions: PVL is a complex scenario after conventional AVR for AR in BD. Modified Bentall procedure seems superior to isolated AVR in these cases. The use of IST and steroids before and after surgery in combination with modified Bentall procedure could have a role in effectively reducing PVL.

Impact of pulmonary arterial systolic pressure on patients with mitral valve disease combined with atrial fibrillation.

Objective: To determine whether different changes of pulmonary artery systolic pressure (PASP) after surgeries have an impact on the long-term outcomes in patients with rheumatic and degenerative mitral valve (MV) disease and atrial fibrillation. Methods: Between 2004 and 2016, 1,188 patients with rheumatic and degenerative MV disease undergoing MV and Cox-Maze procedure were identified. Clinic outcomes, as well as rhythm state and echocardiography indices in long-term follow-up were recorded. Patients were grouped by the changes of PASP (persistently normal, persistently increased, increased, and decreased) from preoperative estimation to follow-up. Results: A complete echocardiography was performed at baseline and after 5 years. During follow-up, free of death and atrial fibrillation (AF) off antiarrhythmic drugs was 90 and 61%, 78 and 41% at 5 and 10 years, respectively. Survival rate was higher in patients with persistently normal and became worse in patients with persistently increased and increased PASP (log-rank 166.0, P < 0.0001). Moreover, the patients with persistently normal PASP had a lowest risk of recurrent AF (SHR: 0817; CI: 0.765-0.872; P < 0.0001) after considering death as a competing risk. A persistently normal PASP at follow-up and degenerative MV disease were associated with improved survival and sinus rhythm (SR) maintenance at multivariable Cox regression analysis (P < 0.05). Conclusion: Patients with degenerative MV disease or have persistently normal PASP during follow-up have better survival and SR maintenance rate than patients with either rheumatic MV disease or persistently abnormal PASP.

Impacts of vegetation on particle concentrations in roadside environments.

In roadside environments, commuters are exposed to a high level of traffic-related pollution. Despite vegetation is often used to mitigate air pollution in road environments, its air quality impacts are complex and could be both positive or negative depending on specific conditions. This study conducted field measurements to assess the air quality impacts of roadside vegetation. Three common street vegetation configurations (dense vegetation, porous vegetation, and clearing) were selected and the concentrations of size-resolved particles and black carbon were measured. Results show that dense vegetation formed an accumulation area of particle pollutants on the sidewalk and bikeway, which was attributable to the increased deposition of pollutants. Compared with porous vegetation, the increase in particle concentrations before dense vegetation was 0-35% on the sidewalk (closer to vegetation) and 0-6% on the bikeway. Due to high homogeneity, fine particles (0.3-1 µm) showed low variability among different sample points, while coarse particles (>1 µm) showed high variability and presented a significant increase in concentration before dense vegetation. Porous vegetation showed weak interception effects on pollutants, and the particle concentrations before porous vegetation were close to those in the clearing. The horizontal decay of particle concentrations in porous and dense vegetation showed that particle pollutants were difficult to penetrate dense vegetation, which concentrations of particles presented a pronounced increase in the front part (0-5 m) of dense vegetation but also showed a large drop across it. These results suggest that vegetation serves as a good filter to clean the air and could improve the air quality away from the vegetation but could also worsen the air quality close to the vegetation. This study provides an insight into the environmental impacts of roadside vegetation, which could have practical implications in air pollution abatement.

[Efficacy of mitral valve repair for anterior leaflet prolapse of mitral valve].

OBJECTIVE: To evaluate the therapeutic effects of mitral valve repair for the treatment of the anterior leaflet prolapse of mitral valve. METHODS: From November 1998 to October 2007, 210 patients with severe anterior leaflet prolapse of mitral valve underwent valve repair. The condition of valve was preoperative, intraoperative, and postoperative assessed with echocardiography. RESULTS: Edge-to-edge repair technique was used in 134 cases (63.8%). The cardiac function was NYHA class I in 168 cases and class II in 40 cases after operation. Patients were followup for 1 - 150 (25.7 +/- 29.0) months, two patients (0.95%) died of postoperative low cardiac output syndrome. Echocardiography examination indicated that the mean JP2 postoperative left atrial diameter was (37.7 +/- 9.2) mm against the preoperative value of (47.5 +/- 12.7) mm (P < 0.05), the mean postoperative left ventricular end-diastolic diameter was (51.7 +/- 7.9) mm against the preoperative value of (67.7 +/- 10.3) mm (P < 0.05), the mean postoperative left ventricular ejection fraction was (62.2 +/- 3.2)% against the preoperative value of (52.2 +/- 6.4)% (P < 0.05), and the mean preoperative regurgitation area was (10.4 +/- 4.1) cm(2) against the postoperative value of (4.1 +/- 1.7) cm(2) (P < 0.01). CONCLUSIONS: Optimal outcome was achieved by appropriate edge-to-edge technique or other mitral valve repair techniques for anterior leaflet prolapse of mitral valve. Edge-to-edge technique is a reliable and efficient surgical technique.

Acute Aortic Dissection in Young Adult Patients: Clinical Characteristics, Management, and Perioperative Outcomes.

Background: Acute aorta dissection (AD) is a fatal emergency, however, studies addressing the clinical characteristics, management, and outcome of acute AD in young adult patients aged under 45 years in China are very few.Methods: A retrospective study including 490 patients with acute AD as the final diagnosis was conducted. Patients' demographics, clinical characteristics, medical history, and laboratory and diagnostic imaging findings were retrieved from medical records. Results: The median age of young adult patients with acute AD was 38 years old with an interquartile range from 33 to 41. Male and smoker constituted 84.49% and 50.61% of the cohort, respectively. Hypertension was found in 54.49%, while Marfan syndrome was seen in 4.29% of the patients. Abrupt onset of chest or back pain was the most common symptoms (85.31%), while altered consciousness, coma and oliguria were less reported. Most patients (89.39%) were managed with surgical interventions. Typical complications (central nervous system complications, spinal cord ischemia, myocardial ischemia/infarction, mesenteric ischemia/infarction and acute renal failure) were seen in a small portion of treated patients during perioperative period. For in-hospital mortality there were 24 (∼5%) cases recorded. Correlation analysis indicated that perioperative complications were associated with the length of cardiopulmonary bypass (CPB) (P < 0.0001), and mortality after surgery correlated history of prior cardiac surgery (P = 0.043). Conclusion: CPB and prior cardiac surgery were associated with perioperative complications and mortality after surgery, respectively. The findings are valuable to the further refinement of diagnosis and surgical management of patients with acute aortic dissection.

Treatment with Corticosteroid and/or Immunosuppressive Agents before Surgery can Effectively Improve the Surgical Outcome in Patients with Takayasu's Arteritis.

OBJECTIVE: To analyze the clinical outcome of corticosteroid and/or immunosuppressive treatment preoperatively in patients with Takayasu's arteritis. PATIENTS AND METHODS: Forty-six patients with Takayasu's arteritis who received cardiovascular surgery between January 2010 and December 2015 in Beijing Anzhen Hospital were enrolled in this study. Their clinical characteristics, preoperative drug therapy, surgical treatment, and pathological examination results were retrospectively analyzed for the effect of drugs on outcome of the surgery. RESULTS: All 8 patients with active disease prior to surgery had postoperative complications including one death due to stubborn perivalvular regurgitation induced heart failure during the perioperative period. Among 38 patients without active disease prior to surgery, only 4 patients (10.5%) had postoperative complications. Thirty-four patients showed symptomatic relief in the perioperative period, of whom 23 patients treated with corticosteroid and/or immunosuppressive agents preoperatively. CONCLUSION: The surgery can effectively improve the symptoms of patients with Takayasu's arteritis. Active disease of Takayasu's arteritis markedly increased risk for postoperative complication and resulted in poor outcome of the surgery. Treatment with corticosteroid and/or immunosuppressive agents before surgery can effectively control the patient's condition, improve the rate of remission, and effectively reduce the incidence of postoperative complications.

Thoracoabdominal aortic replacement for Crawford extent II aneurysm after thoracic endovascular aortic repair.

BACKGROUND: The surgical treatment of Crawford extent II aneurysms after thoracic endovascular aortic repair (TEVAR) remains challenging, because of the need to remove the failed endograft and the complexity of the aortic reconstruction. We retrospectively reviewed our experience with surgical management of Crawford extent II aneurysms after TEVAR using thoracoabdominal aortic replacement (TAAR). METHODS: Eleven patients (10 males, 1 female) with Crawford extent II aneurysm after TEVAR were treated with TAAR between August 2012 and May 2015. The indications included: diameter >5.0 cm; persistent pain; size increase >0.5 cm/year; and no suitable landing zone for re-TEVAR. Five patients underwent surgery under deep hypothermic cardiac arrest, two under mild hypothermic cardiopulmonary bypass, and four under direct aortic cross-clamping under normothermia. Two patients had Marfan syndrome. RESULTS: There were no in-hospital deaths. Continuous renal replacement therapy was required in three patients. One patient needed re-intubation, and two patients had prolonged intubation (>72 h). One patient sustained paraplegia after surgery but recovered during follow-up. Cerebrospinal fluid drainage were used in four patients (3 immediately in the operation room, and 1 in the intensive care unit when the patient suffered paraplegia). One patient died during follow-up. CONCLUSIONS: TAAR represents a feasible option for the treatment of Crawford extent II aneurysms after TEVAR, with acceptable surgical risks and favorable results.

Onychogryphosis in tuberous sclerosis complex: an unusual feature.

Onychogryphosis is an acquired nail plate change. It often affects the toenail and is characterized by an opaque, yellow-brownish nail plate that is distorted, grossly thickened, elongated, and partly curved resembling a ram's horn. Tuberous sclerosis complex is a multisystem disorder associated with high rates of mental retardation, autism, cognitive impairment, behavioral problems, or seizures. Nail disease can also be associated, which is a concern to patients due to pain and nail distortion. We reported a typical tuberous sclerosis complex patient with distinctive clinical features of a ram's horn nails, which presented a great challenge to surgical treatment and nail restoration.

Effects of residual water on microtensile bond strength of one-bottle dentin adhesive systems with different solvent bases.

BACKGROUND: The wet-bonding technique is recommended for the one-bottle dentin adhesive systems, but the moisture concept varies widely among the instructions of manufacturers as well as among investigators. The aim of this study was to evaluate the effects of different dentin surface moisture on the microtensile bond strength(s) of an ethanol/water-based adhesive system and an acetone-based system to dentin. METHODS: Forty intact human premolars extracted for orthodontic reasons were used. Superficial occlusal flat dentin surfaces of these premolars were exposed, finished with wet 600-grit silicon carbide paper. Under four wet and dry conditions (overwet, blot dry, one-second dry and desiccated), resin composite was bonded to dentin by using Single Bond (SB) or Prime & Bond NT (PB) according to the manufacturers' instructions. The teeth were longitudinally sectioned in the "x" and "y" directions to obtain bonded beams with a cross-sectional area of 0.81 mm(2) with a slow-speed diamond saw. The bonded specimens were tested in tension at a crosshead speed of 1 mm/min until failure of the bonds. Failure modes were observed with a scanning electron microscope. The mean bond strengths were analyzed by one-way ANOVA and Turkey's test. RESULTS: The bond strength of the overwet/SB, blot dry/SB, one-second dry/SB and desiccated/SB groups was 10.87 MPa, 22.47 MPa, 24.91 MPa and 12.99 MPa, respectively. The bond strength of the overwet/PB, blot dry/PB, one-second dry/PB and desiccated/PB groups was 10.02 MPa, 20.67 MPa, 21.82 MPa and 10.09 MPa, respectively. For both SB and PB, the blot dry group and one-second dry group revealed significantly higher bond strengths than the overwet and desiccated groups (P < 0.05). CONCLUSIONS: In order to achieve the highest bond strength to dentin, keeping the dentin surface in an appropriately moist condition is critical for the one-bottle dentin adhesive systems with ethanol/water or acetone solvent.

[The observation of serum sexual hormone levels before and after treatment in male hyperthyroidisms].

OBJECTIVE: To explore the changes of serum sexual hormone levels in male hyperthyroidisms before and after treatment. METHODS: Compared with the control group, the serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T) and estradiol (E2) of 68 cases of male hyperthyroidisms before and after treatment were detected by chemiluminescence immunoassay technique, and then statistical analysis was performed. RESULTS: The serum T and E2 levels of male hyperthyroidisms were significantly higher than those of the control group before treatment (P < 0.005); while no significant difference in FSH and LH levels existed between the patients and the control group (P > 0.05). There was no difference in FSH, LH, T and E2 levels between patients and the control group after treatment (P > 0.05). CONCLUSION: There are sexual hormone metabolism disorder in hyperthyroidism men, and the increasing serum T and E2 levels are only to adapt the high metabolism environment, and the changes of hypothalamus-pituitary-gonadal axes. Along with the control of hyperthyroidism, the sexual hormone levels return to normal.

A new phenyl glycoside from the aerial parts of Equisetum hyemale.

A new phenyl glycoside, 2-(sophorosyl)-1-(4-hydroxyphenyl)ethanone (9), was isolated from the ethanolic extract of the aerial parts of Equisetum hyemale L., together with eight known compounds (1-8). The structures of these compounds were elucidated using a combination of spectroscopic analyses and chemical method. Of these nine compounds, 4 and 7 showed hepatoprotective effects towards tacrine-induced cytotoxicity in Hep 3B cells with EC50 values of 42.7 ± 1.5 and 132.6 ± 2.8 µM, respectively.

Onychogryphosis in tuberous sclerosis complex: an unusual feature

Abstract Onychogryphosis is an acquired nail plate change. It often affects the toenail and is characterized by an opaque, yellow-brownish nail plate that is distorted, grossly thickened, elongated, and partly curved resembling a ram's horn. Tuberous sclerosis complex is a multisystem disorder associated with high rates of mental retardation, autism, cognitive impairment, behavioral problems, or seizures. Nail disease can also be associated, which is a concern to patients due to pain and nail distortion. We reported a typical tuberous sclerosis complex patient with distinctive clinical features of a ram's horn nails, which presented a great challenge to surgical treatment and nail restoration.

[Influence of different dentin depths on microtensile bond strength of two dentin adhesive systems].

PURPOSE: To determine the microtensile bond strength of two adhesives systems to either superficial or deep dentin. METHODS: The crowns extracted human premolars were transversally sectioned next to the occlusal DEJ to expose flat dentin surfaces. The surfaces were bonded with: (1)two-step, total-etch adhesive Prime&Bond NT (PB),(2)wo-step, self-etching adhesive FL-Bond (FB), according to manufacturers' directions. Composite build-ups were constructed incrementally. After storage for 24 hours in water at 37 degrees, the teeth were longitudinally sectioned in the "x" and "y" directions to obtain bonded sticks with a cross-sectional area of 0.81mm(2) with a slow-speed diamond saw. The remaining dentin thickness (RDT) was measured to assess the superficial dentin group (RDT> or =3mm) and the deep dentin group (RDT< or =2mm). Microtensile bond strength measurements were evaluated. Fractured specimens were examined with a stereomicroscope at 60 magnification to determine the mode of failure. SPSS11.5 software package was used for analysis of the bond strengths. RESULTS: The results showed the bond strength of Prime&Bond NT were significantly higher either to superficial or deep dentin(P<0.05). Different dentin depths had no effect on the microtensile bond strengths of dentin bonding agent (P>0.05). No cohesive failure was observed in either superficial or deep dentin. Most of the failure was adhesive failure. CONCLUSIONS: From this study, it can be concluded that different dentin depths can not influence the microtensile bond strengths of Prime&Bond NT and FL-Bond adhesive systems.

[Microtensile bond strength and morphological evaluations of total-etch and self-etch adhesives to caries-affected dentin].

OBJECTIVE: To evaluate the microtensile bond strength and bond interface of total-etch or self-etch adhesives to normal dentin and caries-affected dentin. METHODS: A total of 20 molars with occlusal caries lesion were used. The caries-affected dentin was obtained by removing the caries-infected dentin under the guidance of the caries detector. Beyond the level of caries-affected dentin all the enamel and partial dentin were removed. The adhesive systems, two total-etch adhesives (All-Bond 2, Prime&Bond NT) and two self-etch adhesives (Clearfil SE Bond, Xeno III) were applied respectively under the instructions of manufacturers. A block of composite resin was build up superficially. All the teeth were sectioned to obtain bar-shaped specimens with bonded surface area about 0.9 mm x 0.9 mm. The specimens were divided into normal dentin group and caries-affected dentin group via stereomicroscope. The bond strength was tested in a microtensile tester with a crosshead speed of 1 mm/min. The mean values of bond strength were compared using two-way ANOVA. The bonding interface between the dentin and adhesives was qualitatively evaluated under the observation of scanning electron microscope (SEM). RESULTS: Two-way ANOVA revealed a significant influence of both the type of dentin and the adhesive systems tested on microtensile bond strength values. All the adhesives attained higher strength in normal dentin. In normal dentin, there was no significant difference between total-etch and self-etch adhesives. In caries-affected dentin, bond strength of Xeno III was significantly lower than the others. For SEM, the hybrid layer in caries-affected dentin was thicker but more porous than that in normal dentin. Compared with normal dentin, there was fewer resin tag exhibited in caries-affected dentin and no lateral branches were observed. CONCLUSIONS: The total-etch adhesive had higher bond strength than self-etch adhesive systems in caries-affected dentin.

[Influence of storage methods on microtensile bond strength of dentin adhesive system].

PURPOSE: To compare the effects of teeth stored with different methods and different durations of storage on the microtensile bond strength of the dentin adhesive system Single Bond. METHODS: 30 human first premolars were stored immediately after extraction in one of five commonly used methods respectively: 0.02% distilled water and thymol, 10% formalin, 1% chloramine, distilled water at 4 degrees C and were refrigerated at -20 degrees C. After 10 days, 90 days, the dentin adhesive system Single Bond and composite Z250 were applied to superficial occlusal flat dentin according to the manufacturers' instructions and microtensile bond strength measurements were evaluated, freshly extracted teeth being used as control. Stero-microscope and scanning electronic microscope were used to evaluate the fracture modes of the microtensile bond strength specimens. Two-way ANOVA was used for analysis of the microtensile bond strengths among different groups. RESULTS: The results showed that there was significant difference among five tooth storage methods on the microtensile bond strength of dentin bonding agent (P=0.01). Compared with freshly extracted teeth, two of five storage methods/media, 0.02% distilled water and thymol at 4 degrees C (P=0.008) and distilled water at 4 degrees C (P=0.024), resulted in significantly lower microtensile bond strengths. The duration of teeth storage had no effect on the microtensile bond strength of dentin bonding agent (P=0.279). The interaction of two factors was significant (P=0.000). Stero-microscope and SEM examination indicated that all fracture modes were adhesive failures. CONCLUSIONS: From this study, it can be concluded that the teeth storage methods/media can influence the microtensile bond strength of Single Bond adhesive system. If sufficient numbers of freshly extracted teeth are not available for bond strength test, the freezing teeth at -20 degrees C and teeth stored in 1% chloramine at 4 degrees C are preferred .

[Microtensile bond strengths of three dentin adhesive systems].

OBJECTIVE: To evaluate in vitro the microtensile bond strengths of three dentin adhesive systems and their respective fracture modes. METHODS: A total of 15 intact young human premolars extracted for orthodontic reasons were used. The enamel of occlusal surfaces of these premolar teeth was removed and superficial dentine was exposed, finished with wet 600-grit silicon carbide paper. And then these teeth were randomly divided into three groups. A block of composite resin was bonded respectively with three dentin adhesive systems: All-bond 2 (Group AB(2)), Fluoro-Bond (Group FB) and Xeno III (Group Xeno) according to manufacturers' instructions. The bonded teeth were kept in distilled water for 24 h at 37 degrees C. The roots were removed from the remaining crown approximately 1 - 2 mm below the cemento-enamel junction with a slow-speed diamond saw. The teeth were sectioned to obtain bar-shaped specimens, whose bonded surface areas were about 0.8 mm(2). The specimens were stressed at a crosshead speed of 1 mm/min until rupture of the bond. SEM was used to observe the fracture modes. The mean bond strengths were compared using one-way ANOVA and LSD tests. The frequency of fracture modes was compared using Krukal-Wallis and Mann-Whitney U-test. RESULTS: Mean microtensile bond strengths were (29.56 +/- 5.47) MPa for Group AB(2), (15.81 +/- 7.67) MPa for Group Xeno, and (14.61 +/- 4.50) MPa for Group FB. The bond strength of Group AB(2) was greater than those of the other two groups (P < 0.01). The bond strengths of Group Xeno and Group FB were not significantly different. SEM examination indicated that the adhesive failure was the most mode of fracture. CONCLUSIONS: The microtensil bond strengths of three dentin adhesive systems to normal human dentine were different and the total-etching adhesive All-Bond 2 exhibited the greatest bond strength. It was recommended that dentin adhesive agent should be used according to clinical situation.