ObjectiveTo observe the effects of the two kinds of rigid fixed bridge design on the stress of the alveolar bone of mandibular first molar after hemisection.MethodsThe normal mandibular first molars were selected as control group. The two-abutment teeth and three-abutment teeth rigidly fixed bridge designs were selected as trial group. Stress distributions in the remaining sections of the alveolar bone models were evaluated with photoelastic stress analysis method.ResultsThe stress values of two kinds of rigid fixed bridge design were higher than the control group but still below the twice. There was no significantly difference between two-abutment teeth rigidly fixed bridge design and three-abutment teeth rigidly fixed bridge design (P>0.05).ConclusionTwo-abutment teeth rigidly fixed bridge of mandibular first molar should be chosen after hemisection.

ObjectiveTo discuss the design and fabrication of the photoelastic model of mandibular first molar after hemisection.MethodsAccording to principles of similarity, different materials were used to manufacture the photoelastic model of mandibular first molar with hemisection, which included teeth, alveolar bone and pericementum.ResultsThe photoelastic modle of mandibular first molar with hemisection was manufactured, which was as similar as noumenon in appearance, parameter and boundary condition.ConclusionThe photoelastic model can be applied in qualitative analysis of the stress distribution in the periodontal supporting tissues of mandibular first molar with hemisection.

Adult ; China ; Humans ; Male ; Neisseria meningitidis, Serogroup C ; drug effects ; genetics ; isolation & purification

To investigate the effect of acid and alkali stress on ginsenoside content of Panax ginseng, adventitious roots culture in bioreactors were incubated for 30 d and pH value was adjusted. Ginsenoside content increased by reducing or raising the pH in culture medium, the muxium ginsenoside content was determined on the 5th days after acid treatment and on the 7th days after alkali treatment. The result of histochemical localization of ginsenoside revealed that the red color from light to dark were found in the adventitious root tissue, and ginsenoside mainly located in the pericycle cells where appeared the dark red color.
Ginsenosides ; metabolism ; Hydrogen-Ion Concentration ; Panax ; metabolism ; physiology ; Plant Roots ; metabolism ; Stress, Physiological ; Time Factors

To improve cell suspension culture system of Panax ginseng, the dynamic of cell growth and medium consumption were studied, and the effects of filter on the culture vessel, revolution number, and inoculation density on cell growth and ginsenoside accumulation were also investigated. The maximum cell growth and ginsenoside accumulation was found on the 20th days of suspension culture, therefore, 20 days were confirmed as a suitable culture period for mass production of ginsenoside. Cell growth and ginsenoside content were promoted when the culture vessel had a ventilated filter. Revolution speed during suspension culture affected cell growth, but not ginsenoside content, a peak of ginsenoside productivity was found in the treatment of 120 r x min(-1). Inoculation density also influenced cell growth and ginsenoside accumulation, inoculation density of 6 g was better than other inoculation densities, the ginsenoside content and productivity were up to 12.8 mg x g(-1) DW and 146.6 mg x L(-1), respectively.
Cell Culture Techniques ; methods ; Cell Proliferation ; Culture Media ; chemistry ; Ginsenosides ; metabolism ; Panax ; cytology ; growth & development ; metabolism ; Suspensions

OBJECTIVETo evaluate mechanical behavior of different fixed prosthesis following molar hemisection therapy for clinical reference.

METHODSFinite element method and photoelastic method were employed to investigate the stress distribution around the reserved distal root of the first mandibular molar with various fixed prosthesis designs. The restorations of single crown of the first mandibular molar, combined crowns of the first and second mandibular molars, combined crowns of the second mandibular premolar and first mandibular molar, and combined crowns of the second mandibular premolar, the first and second mandibular molars were designed. The same load was simulated on the occlusal surfaces of the molars.

RESULTSThe results of two studies showed that the stress around the reserved root in the single crown model was over 3 times as much as that of the normal model, the first mandibular molar with normal roots and a crown. For the combined crowns of the first and second mandibular molars, the stress was almost twice of the normal stress. While in the models of the combined crowns of the second mandibular premolar and first mandibular molar, as well as the combined crowns of the second mandibular premolar, the first and second mandibular molars, the stress distributions were similar to that in normal conditions.

CONCLUSIONSBoth the results indicated that the restoration of two-unit dual-ended combined crowns has favorable stress distribution and is applicable for the reserved root following the hemisection therapy.

Adult ; Dental Prosthesis Design ; Dental Stress Analysis ; Denture, Partial, Fixed ; Finite Element Analysis ; Humans ; Male ; Mandible ; Models, Anatomic ; Molar

The study is to investigate the effect of angiotensin II (Ang II) and its receptor blockers on migration and endothelin-1 (ET-1) expression of rat vascular adventitial fibroblast subpopulations. Vascular adventitial fibroblasts were individually expanded by using cloning rings, and the effects of Ang II on the migration of adventitial fibroblast subpopulations were evaluated by Transwell. Fluorescence quantitative-PCR detected the expression of preproET-1 mRNA induced by Ang II, and its receptor antagonists losartan and PD-123319. The concentration of ET-1 was determined by ELISA. It showed that spindle shaped and epithelioid shaped cells were isolated by using cloning rings, named as spindle cells and round cells. RT-PCR showed that fibroblast subpopulations did not have leukocytes, endothelial cells and smooth muscle cells, namely pure cell lines. Compared with respective control cells, two subpopulations had transferring ability. Ang II significantly improved round cells migration in a concentration-dependent manner, and had no obvious influence on spindle cells migration. Ang II (1 x 10(-8) - 1 x 10(-6) mol x L(-1)) significantly increased the expression of preproET-1 mRNA in round cells (P < 0.01), and had no significant effect on the expression of preproET-1 mRNA in spindle cells. Losartan blocked the expression of preproET-1 mRNA induced by Ang II in round cells, and had no significant effect on the expression of preproET-1 mRNA in spindle cells. The effects of Ang II and ET-1 receptor inhibitors on the release of ET-1 were similar to the expression of preproET-1 mRNA. The results indicate that there are two cell subpopulations: round cells and spindle cells in rat vascular adventitial fibroblasts. Ang II significantly improved cells migration, and increased the expression of ET-1 in round cell subpopulation. It suggested that there may be different migratory mechanisms in two cell subpopulations, and the two subpopulations may play a different role in vascular remodeling and reparative process.
Angiotensin II ; pharmacology ; Angiotensin Receptor Antagonists ; pharmacology ; Animals ; Cell Movement ; drug effects ; Cells, Cultured ; Endothelin-1 ; genetics ; metabolism ; Fibroblasts ; cytology ; metabolism ; Imidazoles ; pharmacology ; Losartan ; pharmacology ; Male ; Pyridines ; pharmacology ; RNA, Messenger ; metabolism ; Rats ; Rats, Sprague-Dawley ; Vasoconstrictor Agents ; pharmacology

OBJECTIVETo explore the factors affecting the growth of protocorms of Dendrobium candidum and substance synthesis in a reactor, in order to provide a new method for mass production of raw materials of D. candidum.

METHODProtocorms in vitro were used as experimental materials to study the effect of inoculum volume, light intensity and air volume on the growth of protocorms of D. candidum and the accumulation of polysaccharide and dendrobine in a 3 L-air lift balloon type bioreactor.

RESULTAfter 30 days of cultivation in a bioreactor, protocorms became dark green and grew well at the inoculum volume of 10 g x L(-1). The polysaccharide content in protocorms showed no difference at various inoculum volumes; whereas the dendrobine content showed differences (with the highest treatment at the inoculum volume of 10 g x L(-1)), particularly the productions of polysaccharide and alkaloid reached the maximum at the inoculum volume of 10 g x L(-1). The condition of 1 600 lx of light intensity was the most favorable for the growth of protocorms. Though light played a role of improving the accumulation of polysaccharide in protocorms of D. candidum, it could inhibit the accumulation of dendrobine. Polysaccharide content and production were better under light conditions of 1 600 and 2 400 lx than dark conditions. Despite the maximum dendrobine content in dark conditions, the dendrobine production showed the maximum in the light condition of 1 600 lx due to poor growth of protocorms. Protocorms grew well and became dark green at the air volume of 0.2 vvm (air volume culture volume per minute) , which was better than at 0.1 and 0.3, with maximum polysaccharide and dendrobine contents and productions.

CONCLUSIONIn a 3 L-air lift balloon type bioreactor with a working volume of 2 L, the conditions of 10 inoculum volume, 1 600 lx light intensity and 0.2 air volume were favorable for the growth of protocorms and the production of dendrobine. This demonstrates that the cultivation of D. candidum and substance synthesis in a reactor is an effectie approach for mass production of polysaccharide and dendrobine.

Air ; Alkaloids ; metabolism ; Bioreactors ; Dendrobium ; growth & development ; metabolism ; radiation effects ; Dose-Response Relationship, Radiation ; Light ; Plants, Medicinal ; growth & development ; metabolism ; radiation effects ; Polysaccharides ; metabolism ; Tissue Culture Techniques ; methods

Adolescent ; Adult ; Aged ; Child ; Echinococcosis, Hepatic ; complications ; surgery ; Female ; Humans ; Male ; Middle Aged ; Young Adult

BACKGROUNDAlveolar echinococcosis located in the adrenal gland can be considered a rare and aggressive infestation that radiologically and macroscopically mimics a malignant neoplasm. Its pathogenesis is poorly understood. This paper describes its clinical and radiological aspects and discusses its proper management.

METHODSThe records of two patients with adrenal gland alveolar echinococcosis who were diagnosed and treated in our center in 2009 were evaluated.

RESULTSNeither patient showed any signs of recurrence following radical surgical treatment and postoperative oral anthelmintic therapy.

CONCLUSIONRadical surgery can be a feasible, effective management option that results in a good prospective outcome.

Adrenal Glands ; pathology ; surgery ; Echinococcosis, Hepatic ; diagnosis ; surgery ; Female ; Humans ; Male ; Middle Aged