Neovascularization effect of biodegradable gelatin microspheres incorporating basic fibroblast growth factor.

Biodegradable microspheres were prepared through glutaraldehyde cross-linking of gelatin without using any surfactants as a carrier matrix of basic fibroblast growth factor (bFGF). In the in vitro system, bFGF was sorbed to microspheres of acidic gelatin with an isoelectric point (IEP) of 5.0, but not to those of basic gelatin with an IEP of 9.0. The rate of bFGF sorption to the acidic gelatin microsphere in phosphate-buffered saline solution (pH 7.4) was smaller than that in water. Following incorporation of bFGF into the microspheres at 4 degrees C for 12 h, bFGF release from the bFGF-incorporating microspheres was studied. Approximately 30% of incorporated bFGF was released from the acidic gelatin microsphere within the initial 3 h, followed by no substantial release, whereas the basic gelatin microsphere released almost completely the incorporated bFGF within 1 day. It is likely that when basic bFGF molecules were immobilized to the acidic gelatin constituting microspheres through polyion complexation, they were not readily released under the in vitro nondegradation condition of gelatin. Incorporation of anionic carboxylmethyl cellulose (CMC) into the acidic gelatin microspheres reduced the amount of bFGF desorbed initially. This indicates that the initial burst is ascribed to free bFGF which is not ionically interacted with the acidic gelatin. CMC will function as a bFGF sorbent to suppress the initial leakage from the microspheres. When injected subcutaneously into the mouse back, bFGF-incorporating acidic gelatin microspheres were degraded over time and induced neovascularization around the injection site, in marked contrast to bFGF in the solution form. CMC incorporation slowed down the biodegradation and vascularization effect of bFGF-incorporating gelatin microspheres. It was concluded that the gelatin microsphere was a promising carrier matrix of bFGF to enhance the vascularization effect.

[An investigation of factors in the pathogenesis of experimental autoimmune uveoretinitis (EAU) in congenic mice].

S-antigen or interphotoreceptor retinoid-binding protein (IRBP), when injected with Freund's complete adjuvant into mice, does not easily cause experimental autoimmune uveoretinitis (EAU). In this report, we describe the results of injecting IRBP with Freund's complete adjuvant, together with the intraperitoneal administration of Bordetella pertussis, into several types of congenic mice (B10, B10A, B10BR, B10D2). These congenic mice, of C57BL/10 (B10) origin, differ at the H-2 locus on chromosome 17. We were able to produce EAU in 38.5% of B10A mice, and 12.5% of B10BR mice, confirming that EAU can develop in these mice that carry the k genotype at the K, I-A, and I-E regions of the major histocompatibility complex (MHC) H-2 locus. We believe that the k genotype of the K, I-A, and I-E regions is important as a factor in the pathogenesis of EAU in congenic B10 mice.

Aluminium beta-cyclodextrin sulphate as a stabilizer and sustained-release carrier for basic fibroblast growth factor.

The water-insoluble aluminium salt of beta-cyclodextrin sulphate (Al.beta-CyD-Sul) was used as a stabilizer and sustained-release carrier for recombinant human basic fibroblast growth factor (bFGF). An adsorbate of bFGF with Al.beta-CyD-Sul was prepared by incubating the protein with a suspension of Al.beta-CyD-Sul in water. The mitogenic activity of bFGF released from the adsorbate, as indicated by the proliferation of kidney cells of baby hamster (BHK-21), was almost comparable with that of the intact bFGF. Al.beta-CyD-Sul significantly protected bFGF from proteolytic degradation by pepsin and alpha-chymotrypsin, compared with the water-soluble sodium salt. The in-vitro release of bFGF from the adsorbate was sustained in proportion to a rise in the ratio of Al.beta-CyD-Sul to the protein in the adsorbate. Of the bFGF preparations evaluated, the adsorbate of bFGF with Al.beta-CyD-Sul, when given subcutaneously to the rat, showed the most prominent increase in the formation of granulation tissues, due to the stabilization and slow-release of the mitogen. The limited data presented here suggest that the adsorbate of bFGF with Al.beta-CyD-Sul has a potent therapeutic efficacy for wound healing, and may be applicable to oral protein formulations for the treatment of intestinal mucosal erosions.

Immunohistochemical study on IRBP-induced EAU.

We studied the pathogenesis of IRBP-induced experimental autoimmune uveoretinitis (EAU) by immunohistochemical detection of various immune cells using specific monoclonal antibodies to their surface markers and adhesion molecules. The following results were obtained: (1) During each stage of EAU, CD4 positive T cells predominated over CD8 positive T cells in the retina and the uvea. (2) One day prior to the clinical onset of disease, la positive cells began to appear in the ciliary body. (3) LFA-1 and ICAM-1 were expressed on intraocularly infiltrating cells. (4) ICAM-1 was also expressed on endothelial cells of uveal and retinal vessels. In addition, ICAM-1 was expressed on ciliary body epithelium and retinal pigment epithelium, a finding which may be associated with the breakdown of the blood-ocular barrier. In conclusion, the expression of LFA-1 and ICAM-1 in EAU demonstrates that adhesion molecules, such as these, play an important role in inflammatory ocular disease in vivo.

Percutaneous nucleotomy. A new concept technique and 12 years' experience.

Lumbar disc herniations and degenerations are very prevalent lesions, and many surgical approaches have been adopted for these conditions. However, the results of conventional or extensive operations have not always been satisfying. In 1975, the author developed the technique of percutaneous nucleotomy in an effort to avoid the major surgeries then employed. Fenestration of the annulus and partial resection of the nuclear substance are achieved percutaneously by a posterolateral approach. Intradiscal pressure is reduced considerably, and relief of irritation of the nerve root or the pain receptors around the disc is obtained. The extraction of the herniated portion of the disc is not achieved by the procedure. However, the amount of herniated disc substance may be reduced by disc decompression with suction. The procedure can be done in a radiology department under local anesthesia and requires 30 to 60 minutes. Of 136 cases followed, 72% of the patients are satisfied. The concept and theoretical considerations, surgical instruments, details of improved technique, results, and complications of percutaneous nucleotomy are introduced and compared with the original technique.

The torque test as a measure of lateral dominance.

The present study was designed to assess the validity of the Torque Test as a measure of functional lateral dominance in children. One hundred forty-nine children were administered the Torque Test and The Harris Test of Lateral Dominance. A low but statistically significant correlation was found between torque and total lateral dominance.