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Biomedical subjects

S Kusaka

Publications and source records attributed to S Kusaka.

81 records · Page 5Linked to original sources

The response of human T lymphocytes against alloantigens following Fas-mediated activation-induced cell death.

We examined the response of T lymphocytes activated with specific alloantigens following Fas-mediated apoptosis; using a mixed lymphocyte culture (MLC) system. Cells obtained from an MLC after 6 or 7 days of culture were incubated for are additional 24 hours in the presence or absence of the agonistic monoclonal antibody (MoAb), 7C11, or the antagonistic MoAb, ZB4. We assessed DNA fragmentation/specific cytotoxiy of the MoAb-treated cells. Cells harvested after 4 days of culture were sensitive to apoptosis induced by 7C11 with maximum DNA fragmentation observed on day 6. ZB4 slightly inhibited apoptosis of the cells compared with controls. The simultaneous addition of recombinant interleukin-2 (rIL-2) with the MoAbs significantly inhibited DNA fragmentation in control and ZB4-treated cells, but had little effect on the 7C11-treated cells. Control and ZB4-treated MLC cells showed cytotoxic activities against specific target cells, namely >10%. In contrast, the 7C11-treated cells showed <5% cytotoxicity. Although the addition of rIL-2 increased specific percentage cytotoxicity of control and ZB4-treated cells, it had little effect on the specific cytotoxic activity of the 7C11-treated MLC cells. These results suggest that specific cytotoxic T lymphocytes may be eliminated via apoptosis mediated by the Fas/Fas ligand system.

Adult↗

Magnifying prismatic lenses for vitrectomy.

PURPOSE: Viewing the fundus at higher magnification during vitrectomy makes surgical procedures much safer; however, the scope of magnification of the peripheral fundus has been limited. For better visualization of the periphery of the fundus, we have developed two new contact lenses called magnifying prismatic lenses. METHODS: The magnifying 15 degrees and 30 degrees prismatic lenses are made of a glass with a high index of refraction (n = 1.883). The lenses have a convex upper surface to provide a magnified view of the peripheral fundus. RESULTS: These magnifying 15 degrees and 30 degrees prismatic lenses provide an approximately 2x magnified view of the peripheral fundus. They also provide a more extensive view of the peripheral fundus than a regular (plano-concave) prismatic lens when the eye is tilted. CONCLUSION: The magnifying prismatic lenses are useful for viewing into the peripheral fundus with higher magnification.

Fundus Oculi↗

Treatment of full-thickness macular holes with autologous serum.

A total of 28 patients (29 eyes) with stage 2-4 idiopathic full-thickness macular holes were treated with the use of autologous serum. Autologous serum (20-30 microL) was placed over each macular hole followed by injection of 16% perfluoropropane gas. Postoperatively, 28 eyes (97%) had flattening of the macular hole, and the hole could not be detected in 27 eyes (93%). Twenty-two eyes (76%) showed visual acuity improvement by at least two lines or more. Preoperative factors such as good visual acuity, earlier stage, and younger age were correlated with postoperative good visual acuity. These results suggest that autologous serum is beneficial in the treatment of full-thickness macular holes.

Adult↗

Long-term visual recovery after scleral buckling for macula-off retinal detachments.

The authors retrospectively investigated the long-term visual recovery in 32 macular reattached eyes that had been monitored for more than 5 years after surgery. The best corrected visual acuities were better at 5 years postoperatively than at 3 months by two lines or more in 17 eyes (53%). In these 17 eyes, visual acuities continued to improve for up to 10 years after surgery. In the other 15 eyes, the visual acuities remained within one line of the 3-month values. Improvement of the long-term postoperative visual acuity was found to be statistically correlated with younger age, no or mild myopia (>-5 diopters), and shorter duration of macular detachment (< or =30 days). Surgeons should be aware that the visual function of reattached retinas may continue to improve over the long term, especially when these beneficial factors are present.

Adolescent↗

Properties and biodegradability of ultra-high-molecular-weight poly[(R)-hydroxybutyrate] produced by a recombinant Escherichia coli.

Ultra-high-molecular-weight poly[(R)-3-hydroxybutyrate] (P(3HB)) (Mw = 3-11 x 10(6)) was produced from glucose by a recombinant Escherichia coli XL1-Blue (pSYL105) harboring Ralstonia eutropha H16 polyhydroxyalkanoate (PHA) biosynthesis genes. Morphology of ultra-high-molecular-weight P(3HB) granules in the recombinant cells was studied by transmission electron microscopy. The recombinant E. coli contained several P(3HB) granules within a cell. Freeze-fracture morphology of ultra-high-molecular-weight P(3HB) granules showed the needle-type as that of P(3HB) granules in R. eutropha. Both the P(3HB) granules in wet cells and wet native granules isolated from the recombinant cells proved to be amorphous on the X-ray diffraction patterns. Mechanical properties of ultra-high-molecular-weight P(3HB) films were markedly improved by stretching over 400%, resulting from high crystallinity and highly oriented crystal regions. Biodegradability of the films of ultra-high-molecular-weight P(3HB) was tested with an extracellular polyhydroxybutyrate depolymerase from Alcaligenes faecalis T1. The rate of enzymatic erosion of P(3HB) films was not dependent of the molecular weight but was dependent of the crystallinity. In addition, it is demonstrated that all ultra-high-molecular-weight P(3HB) films were completely degraded at 25 degrees C in a natural river freshwater within 3 weeks.

Acyltransferases↗