Synthesis of a collagenase inhibitor by gingival fibroblasts in culture.

Human collagenase was inhibited by test solutions of human gingival fibroblast culture media. The fibroblast-derived collagenase inhibitor was only slightly affected by 10 micrograms trypsin but was inactivated with 100 micrograms trypsin. The chaotropic agent KSCN (3 M) completely inactivated the inhibitor, whereas the thiol-blocking reagent, p-aminophenylmercuric acetate, partially inactivated the inhibitor. Inhibitory activity was retained at 60 degrees C but was abolished at 100 degrees C. Following ammonium sulfate fractionation, the fibroblast inhibitor was recovered in the supernatant at concentrations of at least 70% saturation. It is suggested that collagenase latency in soft connective tissues may derive from a collagenase-inhibitor complex formed by interaction of collagenase and a fibroblast-derived inhibitor.

Reducing surgically induced astigmatism by using a scleral tunnel.

We conducted a prospective study of 36 eyes undergoing pars plana lensectomy, vitrectomy, and implantation of an intraocular lens. We used a scleral tunnel begun 3 mm posterior to the corneoscleral limbus and entered the anterior chamber through clear cornea. We found that this technique produced minimal postoperative astigmatism. After follow-up periods ranging from three to 15 months, the average change in the flatter meridian was -0.07 diopter and that in the steeper meridian was +0.26 diopter. The mean induced astigmatism was -0.33 diopter. A group of nine eyes undergoing pars plana lensectomy and vitrectomy alone showed no significant changes in the postoperative astigmatism. Statistical comparisons established that there was no significant difference between eyes undergoing intraocular lens implantation in addition to pars plana lensectomy and vitrectomy and those not undergoing intraocular lens implantation.

Identification of collagenase in cultured blood mononuclear cells.

Mononuclear cells isolated from peripheral whole blood were fractionated by erythrocyte-rosetting into T cells and non-T cell subpopulations which were tested for collagenase-producing capacity. Mononuclear cells and purified T lymphocytes, as well as non-T (B) lymphocytes, produced collagenase during serum-free culture. Removal of the macrophages from the non-T cells did not affect collagenase production by lymphocytes.

Cataract and uveitis management by pars plana lensectomy and vitrectomy by ultrasonic fragmentation.

Cataract and uveitis occurs usually in young individuals and produces loss of vision from opacification of both the lens and vitreous. The condition does not lend itself to conventional surgery. In the experience of the authors and several other investigators, pars plana lensectomy and vitrectomy by ultrasonic fragmentation not only improves vision but apparently causes a remission of uveitis. A retrospective study of 23 eyes with cataract and uveitis undergoing pars plana lensectomy and vitrectomy by ultrasonic fragmentation (21 eyes) or vitrectomy alone (2 eyes) showed improved vision in 91.3%, no operative complications, and remission of the uveitis in 100% with observation periods of 1-11 years (average, 5 years). Pars plana lensectomy and vitrectomy appears to be the treatment of choice in cataract and chronic uveitis.

Pars plana lensectomy and vitrectomy by ultrasonic fragmentation: Part III--Results in eyes without other ocular pathology or an implant.

The records of 320 eyes without other ocular pathology undergoing pars plana lensectomy and vitrectomy by ultrasonic fragmentation for routine cataract extraction without an implant were reviewed retrospectively. Three hundred two (302/320-94.4%) had vision between 20/20-20/40. Reasons for vision less than 20/40 in 18/320 (5.6%) eyes included 5/320 (1.5%) with retinal detachments, 11/320 (3.4%) with clinically apparent cystoid maculopathy, 1/320 (0.3%) with a macular hole, and 1/320 (0.3%) with retained lens material. Comparison was made between 184 lensectomies performed by the original technique and 136 pars plana lensectomies performed by the modified technique. Vision between 20/20-20/40 was achieved by 168/184 (91.3%) of the original technique group versus 134/136 (98.5%) of the modified technique group. In the latter group, there was one retinal detachment (0.7%), one macular hole (0.7%) and no clinical cystoid maculopathy. Fluorescein angiography performed three months postoperatively in eyes having vision of 20/20-20/40 of the modified lensectomy group showed cystoid maculopathy in one eye which had undergone trauma-induced wound dehiscence.