BACKGROUND:Lumbar disc herniation is the most common cause of lumbago in clinic, which seriously affect the patient's daily life, study and work. Therefore, studies on biomechanics of lumbar intervertebral disk benefit to prevent and treat the diseases associated with lumbar intervertebral disk. OBJECTIVE: To summarize the biomechanical progress of lumbar intervertebral disk. METHODS: The first author retrieved China National Knowledge Infrastructure and PubMed database for literatures published from 2009 to 2014. The key words were intervertebral disc, nucleus pulposus, biomechanics, fibrosis annulus, cartilage in Chinese and English, respectively. Articles regarding biomechanical characteristics of lumbar intervertebral disk, nucleus pulposus, fibrosis annulus and cartilage were included, and repetitive studies were excluded. Totaly 5 072 articles were retrieved initialy. In accordance with inclusion and exclusion criteria, 41 articles were included in result analysis. RESULTS AND CONCLUSION:We can fuly understand the pathogenesis, development and adverse consequences of diseases related to the lumbar intervertebral disk by summarizing the structural features and internal pressure of lumbar intervertebral disk and the effect of different loads, biomechanical characteristics of lumbar intervertebral disk with degenerative changes and establishment of mechanical model of lumbar intervertebral disk. It is of directive significance for daily health care of the lumbar intervertebral disk and how to better use force, a physical factor, to solve the lumbar intervertebral disk problems.

Objective To explore the effects of hypoxia on the growth,mitochondria distribution and function of mouse embryonic fibroblasts(MEFs).Methods MEFs were sub-cultured in the hypoxia group containing 5％ oxygen and normal oxygen group containing 20％ oxygen,every 24 hours,living MEFs were counted by using trypan blue staining.Mito-Tracker Green was used to stain mitochondria,then cells were observed by using laser confocal microscope.The ATP kit was used to detect ATP synthesis.Results During the logarithmic phase,the numbers of living cells in the hypoxia group were higher than those in the normal oxygen group,the differences were statistically significant (P＜0.05).The percentages of perinuclear mitochondrial in the hypoxia group were higher than those in the normal oxygen group,the differences were statistically significant (P＜0.05).Meanwhile,the significant difference was found in the ATP level between the two groups (P＜0.05).Conclusion The distribution of mitochondria in MEFs and energy synthesis are influenced by the hypoxic culture condition,which could be better for promoting cell growth compared with normal oxygen culture condition.

The mutation status of calreticulin gene (CALR) is helpful for the diagnosis of JAK2 / MPL mutation-negative myeloproliferative neoplasms (MPN), and is closely related to the MPN progression and prognosis.Currently, Sanger sequencing, PCR-fragment analysis, high resolution melting, Taqman RQPCRand the next generation sequencing have been reported to be used to detecting the CALR gene mutations.A proper method for CALR mutation detection and a right laboratory diagnostic procedure according to the MPN-related molecular markers will facilitate the rapid and effective diagnosis and treatment of MPN.

Myelodysplastic syndromes ( MDS ) represent a heterogeneous group of clonal hematopoietic disorders with diverse clinical course .Because of the heterogeneity and the lack of molecular markers to monitor disease progression, clinical management of MDS patients is challenging .Recently, with the development of molecular analysis techniques , an increasing number of MDS related molecular biomarkers have been reported.In this review, we will discuss the clinical applications of the newly reported molecular makers in terms of diagnosis , prognosis and treatment.These markers may improve the diagnosis and prognostic assessment systems of MDS , which may potentially be used to guide decision making in the individual therapy.

Objective To survey the incidence of acquired adult aplastic anemia (AA) in Shanghai, China. Meanwhile, we compared it with the previous data from China in 1986 and other countries in order to explore the trends. Methods Newly diagnosed AA patients were registered in 6 districts (Jingan, Xuhui, Huangpu, Changning, Putuo, Yangpu ) in Shanghai from 2004 to 2006. Then we calculated the crude and age-adjusted incidence of AA according to the population data from Shanghai Statistic Yearbook. Results There were 38 adult patients with acquired AA. The average crude incidence of AA was 0. 33/100 000 from 2004 to 2006. The incidences per 100 000 persons per year were 0. 40, 0. 14and 0. 64 in 18-34, 35-59 and ≥ 60 years, respectively. The rate of severe AA was 0. 17/100 000.Conclusion The incidence of severe AA has no marked change, but the total rate is a little decreased compared with the data from China in 1986.

Background The application of femtosecond laser in the corneal refractive surgery has made great progression recent years,but the morphology characteristic of corneal stroma surface after making-flap of femtosecond laser is closely concerned.Objective This study was to analyze the influence of photodisrnption of femtosecond laser on the corneal stroma surface and to investigate the effect of different laser pulse energy on the sudace ultrastructure of corneal stroma.Methods Corneal flaps were made with Visu Max femtosecond laser in 16 fresh porcine eyes with the pulse energy 125 nJ,155 nJ and 195 nJ respectively,and Moria-M2 microkeratome was used as control.Scanning electron microscopy (S-3400N Hitachi High-Technologies Corp) was used to observe and compare the ultrastructural characteristic of corneal stroma bed surface after making of corneal flap.Results The corneal strnma was evaporated and created a smooth surface when photodisrnption happened in the femtosecond laser group.Residual tissue bridges could been exhibited among the cavitation bubbles under the scanning electron microscope.Corneal strnma surface was smooth in the 125 nJ pulse energy group,but some tissue bridges still were visible.In the 155 nJ pulse energy group,much more smooth surface was seen without tissue bridges and mechanical damages on the corneal surface.However,the surface quality was worse and many tissue bridges and grooves existed in the 195 nJ pulse energy group.In addition,different sizes of slots caused by big cavitation bubbles were visible with the round and oval shape.The edges were regular and sharp with small damage zone after cutting with femtoseeond laser.However,many elevated fibril tissues could be seen on the corneal surface after making of flap with microkeratome.Many crimp and irregularity tissues were found on the surface.Blunt surface and indentations appeared in the cutting edge.Conclusions The mierostrueture of corneal stroma surface is more smoother after making of corneal flap with fentosecond laser in comparison with microkeratome.Pulse energy of 155 nJ is preferably during the making-flap with femtosecond laser.

OBJECTIVETo investigate the effect of midazolam on human ether-a-go-go (hERG) K+ channels exogenously expressed in human embryonic kidney cells (HEK-293) and the underlying molecular mechanisms.

METHODSWhole-cell patch clamp technique was used to record WT, Y652A and F656C hERG K+ current expressed in HEK-293 cells.

RESULTSMidazolam inhibited hERG K+ current in a concentration-dependent manner, the half-maximum block concentrations (IC50) values were (1.31 ± 0.32) µmol/L. The half-activation voltage (V1/2) were (2.32 ± 0.38) mV for the control and (-1.96 ± 0.83) mV for 1.0 µmol/L midazolam. The half-inactivation voltage (V1/2) was slightly shifted towards negative voltages from (-49.25 ± 0.69) mV in control to (-57.53 ± 0.53) mV after 1.0 µmol/L midazolam (P < 0.05). Mutations in drug-binding sites (Y652A or F656C) of the hERG channel significantly attenuated the hERG current blockade by midazolam.

CONCLUSIONMidazolam can block hERG K+ channel and cause the speed of inactivation faster. Mutations in the drug-binding sites (Y652 or F656) of the hERG channel were found to attenuate hERG current blockage by midazolam.

Dose-Response Relationship, Drug ; Ether-A-Go-Go Potassium Channels ; drug effects ; HEK293 Cells ; Humans ; Midazolam ; pharmacology ; Mutation ; Patch-Clamp Techniques ; Potassium Channel Blockers ; pharmacology

Background Clinical researches showed that antimicrobial-resistance of bacterium is gradually serious.It is very important to master pathogen distribution and antimicrobial susceptibility after eye surgery.Objective This study was to investigate the distribution and drug sensitivity of pathogenic bacteria from ocular operative infection in 3-year duration to provide a reference for reasonable selection of antibiotics.Methods Sixtyfive positive specimens were obtained from 65 patients due to postoperative infection in Department of Ophthalmology of Shenzhou Hospital and Shengjing Hospital from 2009 January through 2011 December.The pathogenic bacteria were isolated and then the drug sensitivity test of conventional antibiotics was performed.Results Among the 65 ophthalmic specimens,35 strains of Gram-positive bacteria were isolated with the constituent ratio 53.8％,and 15 strains of Gram-negative bacteria accounted for 23.1％.Fungus was found in 15 cases with the constituent ratio 23.1％.Staphylococcus epidermidis accounted for 42.9％ in Gram-positive bacteria,and Pseudomonas aeruginosa accounted for 33.3％ in Gram-negative bacteria.Aspergillus was the main component of fungus,which accounted for 60.0％ of the proportion 3 strains of methicillin-resistant Staphylococcus aureus (MRSA) in 8 strains of Staphylococcus aureus,but no vancomycin-resistant Enterococcus (VRE) and vancomycin-resistant Staphylococcus (VRS) were seen.The in vitro drug sensitivity test showed that the main Gram-positive bacteria,Staphylococcus epidermidis and Staphylococcus aureus,were sensitive to linezolid,vancomycin,levofloxacin and ciprofloxacin with the sensitive rates ＞50.0％,and these bacteria were lowly sensitive to penicillin and erythromycin with the sensitive rates ≤30.0％.Pseudomonas aeruginosa appeared to be the main Gram-negative bacteria,showing a sensitive rate ≥ 80.0％ to tobramycin,amikacin,ceftazidime,cefepime,cefoperazone/sulbactam,piperacillin/tazobactam,imipenem and meropenem.Conclusions Staphylococcus epidermidis,Staphylococcus aureus,Pseudomonas aeruginosa and Aspergillus are primary pathogens in ocular infection after operation.Antibiotics such as penicillin,erythromycin,levofloxacin,cefotaxime seem to be relatively high resistant to eye infection.To choose sensitive antibiotics timely and reasonably is a key to the prevention and control of ocular infection after operation.

Background Package and tissue patch implantation are common methods for repair of filtering bleb leaking after anti-glaucoma surgery.But the scarring or re-leakage of filtering bleb probably occur again.Objective This study was to investigate the repair effect of acellular dermal matrix (ADM) on filtering bleb leaking in rabbit model and compare the effectiveness among ADM,amniotic membrane and conjunctival overlap.Methods Trabeculectomy was performed on 48 eyes of 24 New Zealand rabbits,and models of filtering bleb leaking were established.The models were randomized into ADM group,amniotic membrane group and conjunctival covering group based on randomized number table.ADM patches with 4 mm×4 mm were implanted across lamellar cornea and sclera at a bridge in the ADM group,and the same size of amniotic membranes were used in the amniotic membrane group,and conjunctiva was sutured to limbus in the conjunctiva overlap group.The intraocular pressure (IOP) was measured before surgery and 1 day,1 week,1 month,3 months and 6 months after surgery.The biocompatibility of materials above was assessed under the slit lamp microscope,and the status of filtering bleb was evaluated and compared with anterior segment optical coherent tomography (AS-OCT) 1 day,1 week,1 month,3 months and 6 months after surgery.Results Before surgery and 1 day,1 week,1 month,3 months and 6 months after surgery,the IOP was (26.9±4.3),(16.6±5.1),(22.1 ±6.2),(18.3±6.5),(22.7±2.5),(23.4±1.4) mmHg in the AMD group,(29.9±5.4),(14.9 ± 6.4),(21.6 ± 7.8),(26.3 ± 4.1),(26.0 ± 4.2) and (23.0 ± 5.3) mmHg in the amniotic membrane group,and (28.7 ±4.3),(15.7 ±7.0),(22.0±6.3),(28.2±4.1),(24.7 ±4.1),(23.0±2.7) mmHg in the conjunctival overlap group,showing significant differences among different groups and various time points (Fgroup =8.419,P=0.011 ;Ftme =15.543,P=0.000).The IOPs were significantly lower from 1 day through 3 months after operation than those before operation in the AMD group (P =0.000,0.000,0.006,0.045) ; while the IOPs were reduced only from 1 day through 1 week after operation in comparison with before operation in the amniotic membrane group and the conjunctival overlap group (P =0.000,0.001).One month after surgery,the IOPs were significantly declined in the ADM group compared with the amniotic membrane group and the conjunctival overlap group (P =0.001,0.000).The grafts were clear under the slit lamp microscope and exhibited the valid filtering bleb until 3 months after operation under the AS-OCT in the ADM group.However,the valid filtering bleb remained only 1 month after surgery in the amniotic membrane group and the conjunctival overlap group.Neovascularization on the filtering bleb was found 3 months in the AMD group but 1 month in the amniotic membrane group and the conjunctival overlap group.Conclusions Compared with amniotic membrane and conjunctival tissue,ADM patch for the repair of filtering bleb leakage can increase the survival duration of filtering bleb and remain lower IOP.

Objective To investigate the relationship between the disorder of learning and memory in lead rats and the argnine vasopressin (AVP) and the somatotatin (SS) of hippocampus.Methods Sixty healthy 2-month old Sprague-Dawley rats were randomly divided into normal control group and lead group. Normal control group was given deionized water and the lead group was given 0.1% lead acetate deionized water for 3 months to make chronic lead rat. Learning and memory ability was tested by the Y-maze test. The content of AVP and SS in hippocampus were tested by the immunohistochemical method. Results The learning memory ability and the content of AVP and SS in hippocampus CA1 section of the lead group were degraded obviously than the control group(all P0.05)in hippocampus CA3 section of the lead group were degraded also.Conclusion The disorder of the learning and memory of the lead exposure rats may be due to the decrease of the content of AVP and SS in hippocampus.