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Biomedical subjects

R W Carson

Publications and source records attributed to R W Carson.

2 recordsLinked to original sources

Removal of plasma porphyrins with high-flux hemodialysis in porphyria cutanea tarda associated with end-stage renal disease.

Plasma porphyrin levels are markedly increased in patients with porphyria cutanea tarda (PCT) associated with end-stage renal disease. Conventional hemodialysis (CHD) with lower blood flow rates (less than 250 mL/min) and cuprophan or cellulose acetate membranes is ineffective in removing significant amounts of porphyrins in this condition. Changes in plasma porphyrin levels and porphyrin clearances during hemodialysis with higher blood flow rates and more-permeable, high-efficiency cellulose acetate and high-flux polysulfone dialyzers were evaluated in a chronic hemodialysis patient with PCT and markedly elevated plasma porphyrins. The polysulfone membrane achieved significantly better fractional porphyrin removal (P = 0.02) and porphyrin clearances (P less than 0.01) than did the high-efficiency cellulose acetate membrane. After conversion from maintenance CHD with a standard cellulose acetate dialyzer to a 4-wk period of high-flux hemodialysis (HFHD) with a polysulfone dialyzer, predialysis plasma porphyrins fell by 37%. After returning to CHD, plasma porphyrins returned to the higher prestudy levels. These observations suggest that HFHD with more permeable membranes and higher blood flow rates removes porphyrins more effectively than does CHD. HFHD may be a useful adjunct to other measures used in treating dialysis patients with PCT.

Cellulose

Arthroscopic meniscectomy.

A technique is described for doing arthroscopic meniscectomies using short curved instruments passed through flexible, sealable Teflon sleeves. The goal, with few exceptions, was to achieve en bloc subtotal resection of the posterior two-thirds of the meniscus. The location and character of the lesions found in this series tend to support this pattern of excision. Immediate postoperative morbidity is astonishingly less than that seen with open meniscectomy. Economic losses, including medical costs and time off work, were significantly less, and short term results compare favorably with those of conventional meniscectomy in regard to relief of symptoms and restoration of function.

Adult