Stem cells are a group of self-renewal cells with the potential to differentiate into a variety of cell lineages. Embryonic stem cells can differentiate into more than 200 types of cell lineages belonging to endodermal, mesodermal and ectodermal tissues. Corneal epithelial cells derive from epidermal ectoderm during embryonic development. When the ocular surface is severely damaged, corneal epithelium with proliferation potential is essential for its reconstruction. Recent studies are focused on differentiation of bioactive corneal epithelial cells. This review summarizes signaling pathways including Notch, Wnt, bone morphogenetc protein or fibroblast growth factor pathways that are involved in regu?lating the development of embryonic ectoderm and corneal epithelial cells revealed in previous studies.

BACKGROUND: The application of polymerized 2-hydroxyethyl methacryate (PHEMA) in many organs of living body shows good biocompatibility.OBJECTIVE: To observe the biocompatibility and fibrovascular condition of methl-methacrylate (MMA) modified PHEMA hydrogel orbital implant.DESIGN: Single sample observation.SETTING: Department of Ophthalmology, the General Hospital of Chinese PLA; Institute of Polymer Science,Department of Chemical Engineering, Tinghua university.MATERIALS: Twenty-five New Zealand rabbits of either gender and clean grade, weighing 2.0 to 2.5 kg, were provided by the Animal Experimental Center, General Hospital of Chinese PLA. The animals were observed at postoperative 2, 4,8, 12 and 24 weeks, 5 at each time point. The experiment was permitted by ethics committee. MMA modified PHEMA hydrogel orbital implant was provided by Institute of Polymer Research, Department of Chemical Engineering, Tinghua University. The experiment was permitted by ethics committee.METHODS: This experiment was carried out in the laboratory of Department of Ophthalmology, the General Hospital of Chinese PLA from March to October 2003. The right eye served as operation eye. When the rabbits were anesthetized,their eyelids were open with eyelid retractor. Bulbar conjunctiva was open along the edge of limbus of cornea for isolating fascia. Oculorotatory muscle was isolated and pre-set suture line was made, then muscle was cut off. When optical nerve was cut off, eyeball was completely excised. A MMA modified PHEMA hydrogel orbital implant with the diameter of 14 mm was implanted into the fossa orbitalis of rabbits. Single photon emission computed tomography (SPECT) was performed at postoperative 2, 4, 8, 12 and 24 weeks. The hydrogel orbital implant was taken out at postoperative 2, 4, 8,12 and 24 weeks for light microscope, immunohistochemical and electron microscope examinations.MAIN OUTCOME MEASURES: Vascularization of hydrogel orbital implant was observed in vivo by isotope tracing observation at different time points. Vascularization of hydrogel orbital implant was observed ex vivo by light microscope,immunohistochemical and electron microscope observations.RESULTS: All 25 New Zealand rabbits were involved in the final analysis. ①SPECT examination showed that isotope increased around the implants at week 2, and extended gradually at weeks 4 and 8. The radiotracer accumulated evenly in the implants from surrounding to the center at week 12. ②Light microscopic examination of the prostheses revealed fiber vessels grew from the surrounding to the center. At week 2,fibrovascular tissue grew in the hole of implant. Long or round cells with deeply dyed nucleuses were found in the hole, being fibroblasts. The vascular structure in the hole of the implant was clear, and vascular wall and blood cells were found. The inflammatory cells were mainly neutrophils and lymphocytes, and occasionally large macrophages. ③Scanning electron microscope showed that fibrovascular tissue grew in the hole of the implant, and was dense and intercrossed at week 12. ④ Conjunctiva split appeared postoperatively in 1 of 25 cases, and healed well after two times of operation. Conjunctival congestion lessened and conjunctiva healed within postoperative 7 days in the remaining 24 animals.CONCLUSION: MMA modified PHEMA hydrogel orbital implant has good histocompatibility and fast vascularization process, and is easy to be operated with fewer complications. So, it is a safe and practicable new type orbital implant.

Objective To discuss clinical results of self-made anatomical dynamic hip lock plate (ADHLP) in treatment of intertrochanteric fractures. Methods ADHLP was applied in 73 patients in-eluding 52 males and 21 females at age range of 19-92 years ( mean 54.7 years). Fractures were caused by traffic accidents in 32 patients, sllp in 21, fall from height in nine and other factors in 11. According to the Evans' s classification system, there were 42 patients with type Ⅰ fractures, 17 with type Ⅱ, nine with type Ⅲ and five with type Ⅳ. Self-made ADHLP was applied to manage various fractures with differ-ent operation strategies. The curative effect of ADHLP was observed for evaluation of ADHLP. Results The operation lasted for mean 60 minutes (40-90 minutes). The volume of blood loss was mean 200 ml (100-400 ml). All patients were followed up for 6-48 months (average 36 months), which showed that the function of hips was satisfactory, with excellence rate of 99%. There were no complications like coxa yam, femoral head eoncis, rotation displacement, iatrogenic fracture, infection or internal fixation break and loosening. Conclusions ADHLP takes advantages of reasonable vitodynamics, wide operation in-dicatioas, convenient operation, minor trauma, fast recovery, stable fixation and few complications for in-tertrochantefie fractures, especial]y osteoporotie and gemntal patients.

0.05), while there were obvious different effects at different time points in each group and between group A and B (P0.05). There was difference in the number of fibroblats and eosinophils between groups (P

To study cardiac function in an ovine model of chronic heart failure in relation to cardiac collagen and its phenotype, 11 sheep were developed into chronic heart failure by sequential microembolisation. Cardiac collagen contents and phenotypes were determined after hemodynamic evaluation at 6 months. The results showed that collagen contents and type Ⅰ /type Ⅲ collagen ratio in the left ventricle were increased significantly in heart failure group as compared with those in the normal group. Collagen concentration in left ventricle correlated significantly to left ventricular ejection fraction, left ventricular end diastolic pressure, dP/dt min , left ventricular diastolic diameter, and diastolic interventricular septum thickness.Our conclusion is increase in collagen content and type Ⅰ/Ⅲ collagen ratio may be partly responsible for the reduction of cardiac function seen in this model of heart failure.

Objective To evaluate the effect of a new one-piece PHEMA keratoprosthesis(Kpros) implanted in alkali burned rabbit corneas. Methods The experiment included two parts. In part one, the porous discs of PHEMA were inserted into the lamellar pockets of alkali-burned corneas and the results were observed clinically and histologically at various periods. In part two, seven one-piece Kpros were implanted into alkali burned rabbit corneas. The Kpros consisted of a central transparent optical area and a porous semi-transparent peripheral skirt. The surgical procedure was similar to that of penetrating keratoplasty. Clinical observations were carried out till 28 weeks. Results Both the porous discs and one-piece Kpros had been retained during the experiment. Severe complications as cataract, retro corneal membrane, retinal detachment and extrusion of material were not found until 28 weeks. There was no calcification in the samples, and inflammation was mild. Two weeks after implantation, fibroblasts and deposition of collagen were found in the pores of PHEMA discs. The fibroblasts in the pores look healthy and functionally active. The preliminary results were satisfactory. Conclusion This new one-piece Kpros had shown good biocompatibility. The porous peripheral skirt fuses well with the bed of burned cornea and proved to be stable. PHEMA materials is suitable for one-piece Kpros.

BACKGROUND:Polyhydroxyethyl methacrylate has excel ent optical properties and good hydrophilicity which has been widely applied in biological materials, such as contact lenses, intraocular lenses. In previous
experiments, artificial corneas made of polyhydroxyethyl methacrylate subcutaneously implanted or implanted into normal rabbit cornea have showed good biocompatibility and tear resistance.
OBJECTIVE:To evaluate the histopathological results of the porous skirt of new type one-piece keratoprosthesis made of polyhydroxyethyl methacrylate implanted to alkali burned rabbit corneas.
METHODS:New blood vessels and wal eyes formed in New Zealand rabbits at 3 months after alkali burned rabbit corneas. The porous discs of polyhydroxyethyl methacrylate were inserted into the lamel ar pocket of
alkali-burned corneas and the corneas were observed clinical y, histological y and ultrastructural y at 2, 8, 16 and 28 weeks after implantation,.
RESULTS AND CONCLUSION: Histopathology suggested that mild inflammatory reaction and no calcification were seen in al specimens, fibroblasts and deposition of col agens were found in the pores of the dics at 2 weeks after implantation;stable connection with cornea was formed by the end of 16 weeks;the pores were almost completely fil ed with new tissue, the number of cel s decreased, and mature fibers were mainly found at 28 weeks. Scanning electron microscope showed new tissue grew into the pores which were closely connected with the corneas. Transmission electron microscope exhibited cytoplasm migrating into the material was rich in rough endoplasmic reticula, showing strong synthetic function, col agen, proteoglycans, and other extracel ular matrix deposition. These findings indicate that the porous skirt of polyhydroxyethyl methacrylate implanted into the alkali burned rabbit corneas al owed corneal cel s migration, proliferation, secretion of the deposition of extracel ular matrix and the formation of new tissue to complete the stable connection with cornea, showing a better biocompatibility.

Objective To investigate the entry points for clinical work of intensive care unit (ICU) pharmacists.Methods Through combination with daily work and referring the domestic and foreign literature,the characteristics of ICU medications were discussed to find out the entry point for clinical work of ICU pharmacists.Results ICU patients particularly need individualized pharmaceutical care because of the special pathophysiological characteristics and medicine use.Conclusion ICU pharmacists should provide pharmaceutical care based on Pharmacokinetics/pharmacodynamics knowledge and focus on the drug dosage adjustment,drug interactions and adverse event prevention.

Objective To analyze the anatomic factors of the central retinal artery occlusion or the ophthalmic artery occlusion after the injection of facial cosmetic surgery.Methods Retrospectively analyzed 3 patients who occurred severely ocular complications just after facial cosmetic injection in last 2 years.The diagnosis of central retinal artery occlusion was confirmed by fundus examination and fundus fluoresce-in angiography.Analysis the blood vessel distribution of the injection site and characteristics of peri-orbit vascular anastomosis.Results All the 3 cases presented no light perception,with eye pain or (and)the eyeball pain.The fundus test and fundus fluorescein angiographies showed central retinal artery obstruction.Facial cosmetic injection pressure significantly exceeded the ophthalmic artery systolic pressure 2 seconds after injection (P <0.05).Dorsal nasal artery and angular artery were anastomotic,and the angular artery was usually anastomotic with lateral nasal branches of the posterior ciliary artery.The filler can enter the ophthalmic artery by the branches of the anastomosis,which can make ophthalmic artery occlusion,central retinal artery occlusion or get occlusion of their branches.Conclusion The injectant may get into the orbital artery and retrograde to the ophthalmic artery,which resulting in ophthalmic artery occlusion,or get into central retinal artery and posterior ciliary artery,which resulting in serious ocular complications.

BACKGROUND:Titanium implants as a safe biological material have been used to produce the artificial Russian titanium cornea, but complications stil exist, including artificial cornea shift, leakage, corneal tissue melting and artificial cornea discharge.
OBJECTIVE:To evaluate in vivo biocompatibility of hydroxyapatite modified titanium skirt for keratoprosthesis in alkali burn cornea.
METHODS:A total of 30 alkali burned New Zealand white rabbit corneas were divided into three group groups. Hydroxyapatite modified titanium skirt (experimental group) and titanium skirt (control group) were respectively inserted into the corneal stroma of rabbits. In the blank control group, only a lamel ar corneal incision was made.
RESULTS AND CONCLUSION:Al skirts were stable without necrosis, melting and exclusion during the observation period. The number of inflammatory cells in the experimental and control groups was significantly higher than that in the blank control group at 2 and 8 weeks postoperatively (P<0.05), but there was no difference in inflammatory cellinfiltration among different groups by the 16th week. The number of corneal fibroblasts increased significantly in the experimental group compared with the control and blank control group after 2, 8, 16 weeks (P<0.05). The extracellular matrix deposited on the surface of hydroxyapatite modified titanium skirt was denser and tighter than that on the surface of titanium skirt. It indicates that hydroxyapatite modified titanium skirt for keratoprosthesis can promote the interfacial biointegration of skirt and host cornea.