OBJECTIVETo compare the consistency of root canal configuration types of mandibular first premolar by using micro-CT and radio visio graphy (RVG).

METHODSOne hundred extracted mandibular first premolars with complete dental root and apex which received no endodontic treatment were randomly selected. Each tooth was radiographed with RVG through a buccolingual and mesiodistal direction, and then scanned with micro-CT and reconstructed. The classifications of the root canal types according to Vertucci's type with the two methods were compared.

RESULTSThe canal patterns were classified as type I (67%), type III (3%), type V (18%), type VII (2%), additional type (10%) with micro-CT and canal patterns as type I (71%), type III (2%), type V (23%), type VII (1%), additional type (3%) with RVG. 63% of teeth showed one canal in both micro-CT and RVG. Only 25% of teeth were diagnosed as complex canal by the same canal type in both micro-CT and RVG. The Kappa value between micro-CT and RVG was 0.541 which suggested that the two kinds of methods had intermediate consistency. 82.8% of the premolars with root groove had two or more than two canals.

CONCLUSIONAlthough RVG can basically reflect the root canal system type of the mandibular first premolars in vitro, it offers poor accuracy images to complex root canals. Micro-CT three-dimensional images could clearly and precisely display the root canal system morphology of the mandibular first pre-molars in vitro.

Bicuspid ; Dental Pulp Cavity ; Humans ; Mandible ; Molar ; Root Canal Therapy ; Tooth Root ; X-Ray Microtomography

To explore the effects of bilirubin on alveolar macrophages (AM) and expression of iNOS and NO in them in emphysema model, the rats were pretreated with bilirubin before exposed to smoke. AM were isolated from bronchoalveolar lavage fluid (BALF) and cultured. Pathological microscopic examination of AM and immunohistochemical analysis of iNOS were performed. Nitric oxide (NO) content in the samples was determined by nitrate reductase technique. The results showed both alveoli and alveolar septum appeared normal in size and shape in normal group. AM showed kidney-shaped nucleus and were rich in Golgi complexes and primary lysosomes in the cytoplasm. The inner membrane of mitochondrion was continuous. Most cristae of the mitochondria were intact. In model group, the alveoli were expanded, ruptured and bullaes were formed. Both the population and sizes of AM increased significantly. Secondary lysosomes were rich in the cytoplasm. Deformation and pyknosis of the nucleus, swelling of the mitochondrions and rupture of the inner mitochondrial membrane could also be seen. At high magnification, most of the mitochondrial cristae were broken, or completely lost at certain points. In bilirubin group, alveoli partly expanded and the population of AM also increased, with morphological changes being slighter than that in model group. Both NO contents and expression of iNOS in model group were higher than those in normal group (P<0.05). In bilirubin group the two indice were lower than those in model group (P<0.05). Our findings suggested that high expression of iNOS and high NO content in AM accelerate the development of emphysema associated with smoking in rats. Bilirubin may exert protective effects on AM and retards the development of emphysema in rats.
Animals ; Antioxidants ; pharmacology ; Bilirubin ; pharmacology ; Cells, Cultured ; Emphysema ; metabolism ; pathology ; Female ; Macrophages, Alveolar ; drug effects ; metabolism ; pathology ; Male ; Nitric Oxide ; biosynthesis ; Nitric Oxide Synthase ; biosynthesis ; Nitric Oxide Synthase Type II ; Rats ; Rats, Wistar

Objective To investigate the multivariate analysis of renal parenchymal elastic changes in diabetic and the value of virtual touch quantization ( VTQ ) techniques in the diagnosis of diabetic nephropathy . Methods According to urinary albumin excretion rate( UAER) ,72 cases of diabetics were divided into 3 groups:the normal albuminuria group ( UAER<30 mg/24 h) 16 cases ,the trace albuminuria group(30 mg/24 h< UAER< 300 mg/24 h) 30 cases and the mass albuminuria group ( UAER > 300 mg/24 h) 26 cases . And 50 healthy volunteers were selected as the control group . The basic clinical data of subjects were collected ,routine laboratory tests were detected ,and VTQ was used to measure the left renal parenchymal shear wave velocity ( SWV ) ,then the statistical software was applied to analyze these data . Results The left renal parenchymal SWV in the control group ,the normal albuminuria group ,the trace albuminuria group and the mass albuminuria group increased in turn ,respectively ( 2 .01 ± 0 .22 ) m/s , (2 .20 ± 0 .22) m/s ,(2 .51 ± 0 .42) m/s ,(2 .88 ± 0 .32) m/s ,the difference among 4 groups was statistically significant( P <0 .05) . Multiple linear regression analysis showed that SWV ( Y) had linear relationship with duration of diabetes(X1 ) ,left renal parenchymal thickness(X2 ) and serum creatinine(X3 ) ,and the regression equation was Y = 2 .719 + 0 .043 X1 -0 .051 X2 + 0 .002 X3 . In addition ,SWV was positively correlated with the duration of diabetes and serum creatinine ,and negatively correlated with the left renalparenchymal thickness . Conclusions There is correlation between the left renal parenchymal SWV andduration of diabetes ,left renal parenchymal thickness and serum creatinine ,and the left renal parenchymal SWV increases as the renal injury aggravating . VTQ has a certain reference value to judge the degree of early renal damage in diabetics .

Objective To explore the feasibility of the promoting effect of ultrasound targeted microbubble destruction(UTMD) on establishment of type Ⅰ diabetic nephropathy in rats.Methods Forty male SD rats were randomly and equally divided into four groups(n =10):control group(group A),streptozocin group(group B),streptozocin and ultrasound microbubble group(group C) and streptozocin and UTMD group(group D).The fasting blood-glucose (FBG) were tested,the 24 h's urine were collected and the 24 h's urine mieroalbumin(mAlb) were measured and then urinary albumin excretion rate(UAER) were calculated twice a week at fixed time in all groups.When greater than 3-fold increase in UAER compared with controls at the same age and gender,the diabetic nephropathy model in rats was considered to be established successfully,then the change of time and weighed were recorded and rats were killed and collected the blood of left atrial appendage to measure,blood urea nitrogen (BUN),serum creatinine (SCr) and Alanine aminotransferase (ALT).The left kidneys were weighted and then observed glomerular pathological changes under light microscope and detected the expression of CD34 in kidney of rats in each group by immunohistochemical method.Results ①The time of establishing diabetic nephropathy model in group D was obviously shorter than that in group B and C (all P ＜ 0.05).The FBG,the kidney index,UAER,BUN and Scr values in group B,C and D were significantly higher than those in group A(all P ＜0.05),but ALT had no significant change among each groups(all P ＞0.05).②The pathological changes of diabetic nephropathy appeared in rats of group B,C and D;the expression of CD34 in B,C and D groups were raised.Conclusions UTMD can obviously shorten the molding time of type Ⅰ diabetic nephropathy rats,which has feasibility.

Demyelination of the central nervous system often occurs in neurodegenerative diseases， such as multiple sclerosis （MS）. The myelin sheath， a layer of myelin membrane wrapping the axon， plays a role in the rapid conduction and metabolic coupling of impulses for neurons. The exposure of the axon will lead to axonal degeneratio， and further neuronal degeneration， which is the main cause of dysfunction and even disability in patients with demyelinating neurodegenerative diseases. In addition to the demyelination of mature myelin sheath， remyelination disorder is also one of the major reasons leading to the development of the diseases. The myelin sheath is composed of oligodendrocytes （OLs） derived from oligodendrocyte progenitor cells （OPCs） which are differentiated from neural stem cells （NSCs）. The process of myelin regeneration， i.e.， remyelination， is the differentiation of NSCs into OLs. Recent studies have shown that this process is regulated by a variety of genes. MicroRNAs， as important regulators of neurodegenerative diseases， form a complex regulatory network in the process of myelin regeneration. This review summarizes the main molecular pathways of myelin regeneration and microRNAs involved in this process and classifies the mechanisms and targets. This review is expected to provide a theoretical reference for the future research on the treatment of demyelinating diseases by targeting the regulation of microRNAs.