This study aimed to determine the impact of dentinal tubule orientation on dentin bond strength to provide a reference for clinical cavity preparation in resin-bonded restoration.Patients aged 13-16 years were selected,including 18 males and 21 females.Forty-eight human maxillary first premolars from orthodontic extractions were chosen to prepare the test models with the dentinal tubule orientations perpendicular and parallel to the bonding substrate.The test models in the vertical and parallel groups were divided into three groups:total-etching with 20％ phosphoric acid,total-etching with 35％ phosphoric acid and self-etching,with the dentinal tubule surfaces bonded with composite resin blocks in each group.After the standard test models of dentinal tubule-composite resin blocks were placed in distilled water and stored at 37℃ for 24 h,shearing tests were performed using a universal material testing machine at a crosshead speed of 0.5 mm/min.The bond strength values in the vertical group were 19.33±1.59 MPa for the 20％ phosphoric acid group,21.39±2.34 MPa for the 35％ phosphoric acid group,and 16.88±1.54 MPa for the self-etching group.The bond strength values in the parallel group were 24.53±1.99MPa for the 20％ phosphoric acid group,25.16±2.88 MPa for the 35％ phosphoric acid group,and 20.83±1.99 for the self-etching group.After using same total-etching adhesive,the shear bond strength of the parallel group was higher than that of the vertical group,and the difference was statistically significant (P＜0.05).Regardless of vertical group or parallel group,the difference in the bond strength value between the total-etching groups and the self-etching group was statistically significant (P＜0.05).It was concluded that the dentin bonding substrate which was parallel to the direction of the dentin tubule achieved an improved bond strength;the total-etching adhesives achieved higher bond strengths in dentin bond than the self-etching adhesives.

Objective To study the prevalence of the mtDNA A1555G gene mutation in Chinese population with nonsyndromic hearing impairment.Methods PCR-RFLP,directional sequencing of PCR products were applied in 325 patients with nonsyndromic hearing impairment and 50 normal controls.Results The mutation rate of the mtDNA A1555G was 14.5% (47/325),28 of 47 cases were homozygosis,19 of 47 cases were heterozygosis.The same mutation was not detected in the control subjects.Conclusion The mutation rate of the mtDNA A1555G is relatively high in the Chinese NSHI patients,the mutation type includes both heterozygosis and homozygosis.

OBJECTIVETo find out the relationship between mutation of ATP7B gene promoter region and pathogenesis of Wilson disease(WD).

METHODSTwo of 48 WD patients presented C-->T base substitution mutations at the position -183. DNA sequences of the promoter region from normal and mutant samples were separated. The fragments containing the promoter region were cloned upstream of the luciferase. Luciferase activity was analyzed.

RESULTSThe luciferase activity of reporter gene containing normal sequence of ATP7B gene promoter region did not show significant difference as compared with that of reporter gene containing mutant promoter(n=3, P > 0.05).

CONCLUSIONNo influence of C-->T base substitution mutations on the activity of promoter was observed in study. The results suggest that WD pathogenesis relates little to the mutations of the promoter region in Chinese.

Adenosine Triphosphatases ; genetics ; Adolescent ; Adult ; Base Sequence ; Cation Transport Proteins ; genetics ; Cell Line, Tumor ; Child ; Copper-transporting ATPases ; DNA Mutational Analysis ; Female ; Hepatolenticular Degeneration ; genetics ; Humans ; Luciferases ; genetics ; metabolism ; Male ; Middle Aged ; Mutation ; Promoter Regions, Genetic ; genetics ; Young Adult

OBJECTIVETo study mitochondrial DNA (mtDNA) A1555G mutation in seven families with nonsyndromic hearing loss (NSHL).

METHODSPolymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and real time-amplification refractory mutation system-quantitative PCR (ARMS-qPCR) were applied to detect mtDNA A1555G mutation in seven NSHL families. Related clinical data were also collected and analyzed.

RESULTSThe mtDNA A1555G mutation was detected in members from the maternal side, including heteroplasmy and homozygosis, others were negative for this mutation. The copy number of homoplasmic or heteroplasmic mutations of mtDNA A1555G correlated well with the degree of deafness (R = 0.341, P = 0.022 and R = 0.85, P = 0.015, respectively).

CONCLUSIONThe mutation rate of the mtDNA A1555G is high in the NSHL patients, the mutation type include heteroplasmy and homozygosis. There is significant correlation between the mtDNA A1555G copy number and the severity of hearing loss.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child, Preschool ; DNA, Mitochondrial ; genetics ; Female ; Gene Dosage ; Hearing Loss ; genetics ; pathology ; Humans ; Infant ; Male ; Middle Aged ; Pedigree ; Point Mutation ; Young Adult

OBJECTIVETo review the clinical and genetic features of a pedigree of Kennedy disease in China.

METHODSThe clinical data of patients from a Kennedy disease family were collected. The numbers of trinucleotide CAG repeats in exon 1 of the androgen receptor gene were determined by DNA sequencing and repeat fragment analysis.

RESULTSIn the pedigree, 4 patients were identified as Kennedy disease. Clinical manifested with adult-onset, progressive proximal limb muscle weakness and atrophy, gynecomastia, oligospermia were also presented. The number of trinucleotide CAG repeats in exon 1 of the androgen receptor gene was 51 in the proband. The electrophysiological study showed sensory and motor involvement and their serum triglycerides values were elevated significantly.

CONCLUSIONAndrogen receptors gene testing is the most reliable diagnosing method, the patients suspected as Kennedy disease should have a gene testing of androgen receptors.

Base Sequence ; Bulbo-Spinal Atrophy, X-Linked ; diagnosis ; genetics ; Humans ; Male ; Middle Aged ; Molecular Sequence Data ; Pedigree ; Receptors, Androgen ; genetics ; Trinucleotide Repeats ; genetics

OBJECTIVETo investigate the treatment for traumatic intervertebrae disk herniation in cervical thoracic junction.

METHODSFrom 2003 to 2008, there were 10 patients with trautimatic intervertebral disk herniation in cervical thoracic junction, which included 6 males and 4 females, aged from 23 to 66 years (means 41.5 years). All of them were performed through the transforminal approach combined with internal fixation. After operation all patient underwent hyperbaric oxygen treatment. The function of spine was evaluated by JOA score system.

RESULTSAll patients were followed up for 8 to 16 months(means 13 months). All patients got recovery of spine function to some extent except one case with complete spine damaged. The JOA scores was improved from (8 +/- 3) before operation to (15 +/- 2) after operation.

CONCLUSIONEarly and effective treatment by transforminal operation could be helpful for the recovery of spine function.

Adult ; Aged ; Cervical Vertebrae ; injuries ; surgery ; Female ; Fracture Fixation, Internal ; methods ; Humans ; Intervertebral Disc Displacement ; surgery ; Male ; Middle Aged ; Thoracic Vertebrae ; injuries ; surgery

BACKGROUNDIt has been suggested that the ratio of mutant and wild type mitochondrial DNA may be related to its clinical phenotype. In this study, we developed a high sensitive real-time amplification refractory mutation system-quantitative polymerase chain reaction (RT-ARMS-qPCR) assay for quantitation of the mitochondrial DNA (mtDNA) with a mutated 1555 site, and explored the relationship between the ratio of mutated mtDNA and the severity of hearing loss of mitochondrial deafness (MD) patients of Fujian province in China.

METHODSAn amplified mtDNA fragment containing the 1555 site was ligated into a vector to construct a plasmid DNA standard. An RT-ARMS-qPCR system was used to measure the mtDNA copy number containing wild-type and mutant sequences in a cohort of 126 MD patients of Fujian province in China. Combined with the clinical data, we explored the relationship between the ratio of mutated mtDNA and the severity of hearing loss of MD.

RESULTSThe variation coefficient in the cohort was 1.21%, the interassay variation coefficient was 1.78%, and the linear range was 10(2) - 10(8) copies/µl for detecting a recombinant, wild-type plasmid. The primers amplified only the intended sequences. Mutation copy number correlated with the degree of deafness in sporadic cases with heteroplasmic mutations of mtDNA A1555G (R = 0.811, P = 0.003), but not in sporadic cases with homoplasmic mutations (R = 0.007, P = 0.989). The copy number of homoplasmic or heteroplasmic mutations of mtDNA A1555G in familial cases correlated with degree of deafness (R = 0.352, P = 0.023 and R = 0.90, P = 0.012, respectively).

CONCLUSIONSThe RT-ARMS-qPCR system is suitable for determining the copy number of mtDNA fragments containing the A1555G mutation. The ratio of mutated mtDNA correlates with the severity of hearing loss of MD.

Adolescent ; Adult ; Child ; Child, Preschool ; China ; DNA, Mitochondrial ; genetics ; Deafness ; genetics ; Female ; Hearing Loss ; genetics ; Humans ; Male ; Mutation ; Reverse Transcriptase Polymerase Chain Reaction ; Young Adult

Objective To investigate the correlation of behavioral changes to brain edema and histological changes in rats with intracerebral hemorrhage (ICH). Methods ICH was induced by stereotactic injection of type Ⅶ collagenase into the straitum of rats, and the behavioral changes of the rats were assessed within 28 days by forelimb placing test, Berderson's grade and comer turn test. Histological examination of the brain tissue was performed with HE staining, and the brain edema of the rats was measured by dry-wet weight method. Results Behavioral tests of the rats confirmed obvious neurological deficits 2 days after ICH with gradual functional recovery in the following 4 weeks. Histological observation showed the presence of brain injury and evidence of injury repair after ICH. Brain edema was the most evident 2 days after the hemorrhage, which subsided gradually 7 days after ICH. An inverse correlation (r2=- 0.774, P<0.05) was found between forelimb placing score and the severity of brain edema. Conclusion Neural damage and repair occurs in the brain of rats following ICH, and the improvement of the neurological function of the rats is related in the early stage with the alleviation of brain edema, but in later stages, the improvement is associated primarily with histological repair of the neurological damage.

OBJECTIVETo prepare a cisplatin-impregnated coral-derived hydroxyapatite (CCHA) drug delivery system (DDS), and evaluate its inhibitory effect on human osteosarcoma cells U-2 OS, human breast cancer and prostatic carcinoma cells PC-3 in vitro.

METHODSThe coral-derived hydroxyapatite (CHA) was manufactured by hydrothermal exchange and impregnated with cisplatin by vacuum freeze-drying techniques. The leaching solutions of this DDS was collected at different intervals in a course of 8 weeks and their inhibitory effect on the cells was tested in vitro by MTT assay.

RESULTSElectron microscope showed that cisplatin was distributed homogeneously in the pores of CHA. The inhibition rates of the leaching solution on all the tumor cells exceeded 50% except for PC-3 cells, whose inhibition rate was 29.92% when treated with the solution collected at the eighth week.

CONCLUSIONCCHA allows sustained drug release and maintains excellent inhibitory effect on human bone tumor cells within 8 weeks in vitro.

Animals ; Anthozoa ; chemistry ; Antineoplastic Agents ; administration & dosage ; chemistry ; pharmacology ; Cell Line, Tumor ; Cell Survival ; drug effects ; Cisplatin ; administration & dosage ; chemistry ; pharmacology ; Drug Compounding ; methods ; Drug Delivery Systems ; Durapatite ; chemistry ; Humans ; Microscopy, Electron ; Time Factors

Acute Disease ; Adolescent ; Adult ; Aged ; China ; epidemiology ; Female ; Humans ; Male ; Middle Aged ; Pesticides ; poisoning ; Poisoning ; epidemiology