Background Glaucoma,an irreversible optic nerve neuropathy,always results in blindness.This study aimed to evaluate glaucoma-like features in the rat episcleral vein cauterization （EVC） model by multiple in vivo and in vitro evidences.Methods Wistar rat was used in this study.The elevated intraocular pressure （IOP） was induced by cauterization of three episcleral veins.lOP was monitored with Tono-Pen XL tonometer.Time-dependent changes to the neuronal retinal layers were quantified by Fourier domain-optical coherence tomography.The function of retina was evaluated by electroretinogram （ERG）.Survival of retinal ganglion cells （RGCs） was quantified by retrograde labeling.Histology study was performed with retinal sections stained with hematoxylin-eosin,glial fibrillary acidic protein,and neuronal nuclear antigen.Retina and aqueous humor protein were extracted and cytotoxic protein tumor necrosis factor alpha （TNF-α） and alpha-2 macroglobulin （α2m） were measured with Western blotting.Results EVC is a relatively facile intervention,with low failure rates （＜5％）.After surgical intervention,chronic mild lOP elevation （about 1.6-fold over normal,P ＜0.05） was induced for at least 6 weeks without requiring a second intervention.High lOP causes chronic and progressive loss of RGCs （averaging about 4％ per week）,progressive thinning of neuronal retinal layers （3-5 μm per week）,and reduction of a-and b-wave in ERG.EVC method can also induce glial cell activation and alterations of inflammation proteins,such as TNF-α and α2m.Conclusion EVC method can establish a robust,reliable,economic and highly reproducible glaucomatous animal model.
Bai YujingZhu YingtingChen QinXu JingMarinko V. SarunicUri H. SaragoviZhuo Yehong
Background Intra-abdominal hypertension （IAH） is common in acute respiratory distress syndrome （ARDS） patients and when resulting in decrease of chest wall compliance will weaken the effect of positive end expiratory pressure （PEEP）. We investigated the effect of PEEP titrated by transpulmonary pressure （Ptp） on oxygenation and respiratory mechanics in ARDS patients with IAH compared with PEEP titrated by ARDSnet protocol. Methods ARDS patients admitted to the intensive care unit （ICU） of the Zhongda Hospital were enrolled. Patients were ventilated with volume control mode with tidal volume of 6 ml/kg under two different PEEP levels titrated by Ptp method and ARDSnet protocol. Respiratory mechanics, gas exchange and haemodynamics were measured after 30 minutes of ventilation in each round. IAH was defined as intra-abdominal pressure of 12 mmHg or more, Results Seven ARDS patients with IAH and 8 ARDS patients without IAH were enrolled. PEEP titrated by Ptp were significant higher than PEEP titrated by ARDSnet protocol in both ARDS patients with IAH （（17.3±2.6）cmH20 vs. （6.3±1.6） cmH2O and without IAH （（9.5±2.1） cmH2O vs. （7.8±1.9） cmH2O）. Arterial pressure of O2/fraction of inspired oxygen （PaO2/ FiO2） was much higher under PEEP titrated by Ptp when compared with PEEP titrated by ARDSnet protocol in ARDS patients with IAH （（27.2±4.0） cmHg vs. （20.9± 5.0） cmHg. But no significant difference of PaO2/FiO2 between the two methods was found in ARDS patients without IAH. In ARDS patients with IAH, static compliance of lung and respiratory system were higher under PEEP titrated by Ptp than by ARDSnet protocol. In ARDS patients with IAH, central venous pressure （CVP） was higher during PEEP titrated by Ptp than by ARDSnet protocol. Conclusion Positive end expiratory pressure titrated by transpulmonary pressure was higher than PEEP titrated by ARDSnet protocol and improved oxygenation and respiratory mechanics in ARDS patients with IAH.
YANG Yi LI Yang LIU Song-qiao LIU Ling HUANG Ying-zi GUO Feng-mei QIU Hai-bo
This paper concerns two-person zero-sum games for a class of average-payoff continuous-time Markov processes in Polish spaces.The underlying processes are determined by transition rates that are allowed to be unbounded,and the payoff function may have neither upper nor lower bounds.We use two optimality inequalities to replace the so-called optimality equation in the previous literature.Under more general conditions,these optimality inequalities yield the existence of the value of the game and of a pair of optimal stationary strategies.Under some additional conditions we further establish the optimality equation itself.Finally,we use several examples to illustrate our results,and also to show the difference between the conditions in this paper and those in the literature.In particular,one of these examples shows that our approach is more general than all of the existing ones because it allows nonergodic Markov processes.
