Gentisate (2,5 dihydroxybenzoate) pathway is one of three typical routes for bacterial aromatic catabolism Although it is less common than either of the extensively studied pathways through catechols, the gentisate pathway also plays an important role in bacterial aromatic catabolism This article reviews recent developments of this pathway, both in biochemistry and molecular biology

Strain NCIMB 10467, a lignin degrader, was reclassified as genus Burkholderia according to its 16S rDNA sequence. It seems that the metabolism of protocatechuate by this strain is diverse under the induction of various substrates. A 9505-bp DNA fragment extending from α conserved region of the gene, which encodes β subunit of orthocleavage protocatechuate 3, 4-dioxygenase(P34D; EC 1.13.11.3),was obtained by genome walking. Sequence analysis revealed two deduced open reading frames, pcaG and pcaH, encoding the α and β subunits of P34D respectively in this fragment. The P34D activity could be detected when pcaGH were expressed in E. Coli and the disruption of pcaH in strain NCIMB 10467 has lead to loss of its ability to catabolize protocatechuate. It was proved that the cloned pcaGH were encoding a functional protocatechuate 3, 4-dioxygenase which was necessary for the protocatechuate metabolism in this strain.

Objective To access the incidence,clinical characteristics and the factors affecting therapy of respiratory distress syndrome (RDS) in the infants at term and near term delivered by elective cesarean section.Methods A retrospective cohort study among consecutively admitted infants with RDS at the Neonatal Intensive Care Unit of the Department of Neonatology,Xiangya Hospital,Central South University from Jan.2004 to Dec.2011 were conducted.The inborn infants at 36-42 weeks gestation with RDS,whom were delivered by Elective Cesarean Section from January 1 st,2004 to December 31st,2011 were enrolled.These cases with the timing of elective caesarean section,gestational age,intrauterine infection,asphyxia at birth,which affecting the occurrence of RDS were compared.Results Fifty one infants were entered into the study,which were all met standard of Elective Cesarean Section.Among these infants,33 cases (64.7％,33/51 cases) were delivered by cesarean section without any reason.In these 51 cases,the constituent ratio of elective caesarean section in gestational age ＞ 39 weeks was lower than in gestational age ＞ 36-＜39 weeks,and the difference was significant (31.4％ vs 68.6％,x2 =0.560,P ＜0.01).Asphyxia at birth was the main risk factors of term and near term with RDS (OR =7.306,95％CI:0.018-51.101,P =0.041).Compared to the infants whom born without asphyxia,the infants born with asphyxia usually came out to RDS right after born (x2 =0.080,P ＜ 0.01),required longer time of mechanical ventilation and had significant lower effective ratio (x2 =0.071,8.843,all P ＜ 0.01).Conclusions Asphyxia is the first manifestations of term and near term infants with RDS.These infants often can be onset after birth.

OBJECTIVEThe aim of this study was to rebuild the anatomic structures of the mandibular bone and the canal, and to testify the reliability of the rebuilt model.

METHODS15 mandibular bones with teeth are chosen, and a three-dimensional model was built with the method of CT. The slices vertical to the compensating curve were made in every dental position. Then the authors collected the data of alveoli and mandibular canal in every slice. The same work was done to the bone specimen, and then comparative analysis was done.

RESULTSThe wideness of the alveoli and 10 mm bellow increased from mesial to distal position. It was the same of the alveoli from the top to the bottom. The mandibular canal lied in the inner and inferior side of the mandibular body. There was no significant difference in data collected with these two methods.

CONCLUSIONDifferent types of dental implants should be chosen according to the anatomic characteristic of the mandibular bone in every dental position before the operation to avoid complications. And a reliable, accurate and direct method of planning an implant operation is to rebuild a three-dimensional model.

Adult ; Computer Graphics ; Humans ; Mandible ; anatomy & histology ; diagnostic imaging ; innervation ; Mandibular Nerve ; anatomy & histology ; Models, Anatomic ; Tomography, Spiral Computed ; methods

BACKGROUND: Embryonic stem cells fESCs) develop from early blastular inner cell mass.Under proper condition,ESCs can maintain undifferentiated state in vitro,normal diploid nuclear type,and proliferative potential.In addition,ESCs possess multi-directional differentiation capacity and can differentiate into all sorts of cells of three germ layers. OBJECTIVE: To investigate the feasibility of directed differentiation of ESCs towards thyroid cells in vitro as well as related molecular expression. DESIGN,TIME AND SETTING: A cell-based observational experiment was performed at the Bank of Cord Blood,Second Hospital Affiliated to Sun Yat-sen University between January 2004 and December 2006.MATERIALS: Balb/c pregnant mice at pregnancy 12.5-14.5 days were used for preparation of embryonic fibroblast feeder layer.E14 mouse embryonic stem cell (ESC) strains were gifted by professor Xu from Harvard University.METHODS: Murine El4 ESCs were cultured in methylcellulose semisolid medium to form embryoid bodies (Ebs).These Ebs were transferred for further inductive culture with the stepwise addition of growth factors- thyrotropin (TSH),insulin and kalium iodidum (KI).The cultured thyroid cells of adult Kunming mice were taken as positive control.MAIN OUTCOME MEASURES: ①Cellular morphological change in the process of differentiation.② Detection of expression levels of TSHR,PAX8,TTF-2,and TIF-1 by immunofluorescence assay.③ Detection of expression levels of TSHR,PAX8,NIS,TPO,and Tg by reverse transcription-polymerase chain reaction (RT-PCR).RESULTS: The differentiated cells had clear boundary,exhibiting round,oval,shuttle-shaped,or polygon adhesive growth.On day 6 of inductive ifferentiation,the differentiated cells showed the expression of PAX8,NIS,TPO,Tg,and TSHR,the specific gene of thyroid ceils.On day 8 of inductive differentiation,the expression of TSHR,TIF-1,PAX8,and TIF-2 was detectable in the differentiated cells with morphous similar to thyroid cells.CONCLUSION: ESCs can differentiate towards thyroid cells under given inductive conditions.