The vitreous body is a tenuous gel that contains collagen and hyaluronan. The fraction of the polymer network is only about 1-2%. Thus, about 98-99% of water is sustained within 2% of the polymer network. The vitreous body is located between the lens and the retina that comprises 80% of the overall volume of eye. The functions of the vitreous body are supposed to keep the shape of the eyeball, to absorb the external mechanical shock, to maintain the homoeostasis of the eye, and to regulate the position of the lens. The appearance of fresh vitreous body is transparent, and hence, the vitreous body is considered a uniform tissue. Many studies performed to date have suggested that hyaluronan, which has a coil shape, is uniformly distributed throughout the three-dimensional network of collagen fibers that form the triple helix in the vitreous body. Also, as a macroscopic structure, vitreous body has cistern. Further, the collapse of the vitreous body in the eye may cause many diseases such as posterior vitreous detachment, vitreous bleeding, and retinal detachment. We demonstrate the vitreous substitute that contains hyaluronan and its evaluation.

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A cataract is clouding of lens that causes visual disturbance. Age-related cataract is very common. Surgery is the only effective treatment for improvement of visual acuity. Such treatment involves removing the lens and replacing it with an artificial intraocular lens. A viscoelastic substance has both high viscosity and elasticity, so it is widely used to create and reserve space in cataract surgery. Using viscoelastic substance facilitates cataract surgery and reduces corneal endothelial damage. (Corneal endothelium has the function of keeping cornea clear.) Therefore, a viscoelastic substance is a necessary tool in cataract surgery.
Recently, Arshinoff reported a technique using viscoelastic substances with different physical properties to protect the corneal endothelium (soft-shell technique). The soft-shell technique to maximize the advantages and minimize the disadvantages of both types uses dispersive and cohesive viscoelastic substances together in sequence based on the deaired surgical goal. I would like to describe the usefulness of the soft-shell technique in cataract surgery.

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Temporomandibular arthrosis (TMD) is a disease which has symptoms as restricted mouth opening, joint noise and/or joint pain. Therefore several conditions are included in this disease. Now TMD is divided into five categories; the masticatory muscle disorder (type I), capsule-ligament disorders (type II), disc disorders, i.e. internal derangement (type III), degenerative joint diseases, osteoarthrosis (type IV), and others (type V). Type III and IV are the major part of TMD. The etiology had been considered to be “malocclusion” or other “occlusion related conditions”, and so the aim of the treatment of TMD have (had) been directed to eliminate the suspicious malocclusion and to reduce the dislocated disc. Recent studies revealed that the occlusion will not be the true cause of TMD.
Our goal of the treatment of TMD is to improve the ADL of the patients, avoiding the change of the occlusion. To achieve this, we perform “jaw mobilization” like stretching and the intra-articular injection of hyaluronic acid solution after the irrigation of joint space. When comparing the results of the above mentioned method with “jaw mobilization” alone, the combined method showed the better consequence; especially the pain was significantly diminished within two weeks.

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Neo Red Cell (NRC) is a liposome-encapsulated Hb vesicle, which is expected to improve myocardial perfusion because of their high oxygen carrying capacity and small particle size (200nm). To explore the possibility of NRC as a therapeutic agent for coronary microcirculatory failure, we measured regional myocardial flow distributions with and without NRC transfusion. In control (n=6) and in NRC-transfused rats (n=6) under general anesthesia, tritium-labeled desmethylimipramine (HDMI) was injected through a cannula advanced into the left ventricular cavity from a cervical artery. The NRC transfusion was performed by infusing NRC (10 ml) into a femoral vein while collecting arterial blood (10 ml) from a femoral artery. Myocardial slices of 10μm thick were made from the left ventricular subepi-to subendocardium and within-layer HDMI distributions (relative flow distributions) were detected by digitalradiography with the resolution of 100μm. Furthermore, histological evaluation was performed with hematoxylin-eosin staining and hemoglobin staining for the NRC-transfused myocardium. After the NRC transfusion, hematocrit was decreased from 44±2% to 26±5% and volume fraction of NRC was 8±1%. Heart rates and mean blood pressure were almost the same, whereas cervical arterial flow was 1.5 times higher in NRC-transfused than in control rats. Global flow heterogeneity quantitated by the coefficient of variation of flows was lower in NRC-transfused than in control hearts. The histological evaluation showed no evidence of tissue edema and the extravasation of NRC. These results suggest that the NRC transfusion decreases heterogeneity of myocardial flows with keeping the heart performance and reducing microvascular flow resistance. Thus, NRC will have a therapeutic value in the improvement of regional myocardial perfusion.

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