[Motion-in-depth Perception and Static Stereopsis of Patients with Strabismics].

OBJECTIVE: To determine the role of motion-in-depth perception and static stereopsis in strabismics, and factors associated with the perception of motion-in-depth. METHODS: A total of 84 strabismic patients (including 57 intermittent exotropes, 12 constant exotropes and 15 esotropes) and 16 normal controls were recruited. Binocular fusion ability, static stereopsis and motion-in-depth perception were tested using the computer-generated stereoscopic stimuli. The correlations between these tests were analyzed. RESULTS: There was a significant correlation between motion-in-depth perception and static stereopsis in strabismics. Only patients with static stereopsis demonstrated the perception of motion-in-depth. A positive correlation was found between motion-in-depth perception thresholds and static stereopsis in intermittent exotropes. All participants in the control group had motion-in-depth perception and static stereopsis. The participants with stereopsis had significantly lower thresholds than those with strabismus (P<0.01). The perception of motion-in-depth varied with the type of strabismus: 87.7% of the intermittent exotropes exhibited motion-in-depth perception, whereas none of the constant strabismics were able to pass the motion-in-depth perception tests. The perception of motion-in-depth was correlated with the presence of binocular fusion. CONCLUSIONS: Motion-in-depth perception is correlated with static stereopsis in strabismics. The perception of motion-in-depth varies with the type of strabismus: only intermittent exotropes have the perception of motion-in-depth.

[Study of stress distribution in mandibular first premolar restored by composite resin with root screw of different length in different occlusion].

OBJECTIVE: To investigate stress distribution in mandibular first premolar restored by composite resin with root screw of different length in different occlusion. METHODS: An three dimensional finite element model of mandibular first premolar restored by composite resin with root screw was constructed by using spiral CT image reconstruction technique, Mimics, Pro/Engineer, Pro/Mechanica software. Based on this model, stress distribution in dentin, composite resin and root screw was analyzed in the situation of different screw length and different occlusion. RESULTS: When the occlusion was tripod contact and cusp tip-ovoid fossa contact, the stress of dentin, composite resin and root screw were all much less than their compressive strength. And also in this situation, the stress of bond surface between the composite resin and dentin was less than the bond strength of composite resin. The screw was longer but no more than 8 mm, the dentin stress distributes better. CONCLUSION: In the restoration of large area mandibular first premolar crown defection, tripod contact and cusp tip-ovoid fossa contact with 8 mm root screw is recommended.

Encapsulated transgene cells attenuate hypertension, cardiac hypertrophy and enhance renal function in Goldblatt hypertensive rats.

BACKGROUND: The success of any gene-therapy approach depends on the survival of the genetically engineered cells that are implanted in the patient to deliver the therapeutic product. Immunoisolation of nonautologous cells within a microcapsule is a unique approach for gene therapy. METHODS: We employed an immunoisolation device that protects nonautologous cells from destruction, to implant human atrial natriuretic peptide (hANP)-producing Chinese hamster ovary (CHO) cells in two-kidney, one-clip (2K1C) hypertensive rats. CHO cells transfected with the plasmid CMV-cANP were encapsulated in biocompatible polycaprolactone (PCL) capsules, and then the PCL capsules were implanted into 2K1C hypertensive rats intraperitoneally. RESULTS: The implantation of encapsulated hANP-producing cells caused a significant delay of blood pressure (BP) increase 2 weeks post-implantation and the effect lasted for more than 5 months. The implantation of encapsulated hANP-producing cells also caused significant increases in renal blood flow (RBF), glomerular filtration rate (GFR), sodium output, urine excretion, and urinary cGMP levels. These beneficial effects were reflected morphologically by an attenuation of the glomerular sclerotic lesions, reduction in cardiomyocyte size, tubular injury and renal arterial thickening. Immunoreactive hANP can be detected in the blood of 2K1C rats after implantation of the PCL capsules containing hANP-producing cells. CONCLUSIONS: This study demonstrates the usefulness of encapsulated ANP gene transfected cells as a new tool for ANP gene delivery in studying renovascular hypertension and cardiovascular diseases. Thus, our results may have important implications for clinical use of transgene cells as therapeutic agents in the treatment of cardiovascular diseases.