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P F Benson

Publications and source records attributed to P F Benson.

At least 19 recordsLinked to original sources
PubMed1995

EUK-8, a synthetic superoxide dismutase and catalase mimetic, ameliorates acute lung injury in endotoxemic swine.

Reactive oxygen metabolites are believed to be important mediators of sepsis- or lipopolysaccharide (LPS)-induced adult respiratory distress syndrome. EUK-8 is a novel, synthetic, low-molecular-weight salen-manganese complex that exhibits both superoxide dismutase and catalase activities in vitro. We hypothesized that treatment with EUK-8 would ameliorate pulmonary dysfunction in a porcine model of LPS-induced adult respiratory distress syndrome. At T = -18 h, pigs received an intravenous priming dose of LPS (20 micrograms/kg). Anesthetized ventilated swine were randomized to receive 1) no further treatment (n = 5); 2) LPS (250 micrograms/kg from T = 0 to 60 min, n = 6); 3) LPS and a low dose of EUK-8 (10-mg/kg bolus at T = -15 min and 1 mg/kg.h from T = 0 to 240 min, n = 6) or 4) LPS and a higher dose of EUK-8 (10-mg/kg bolus and 3 mg/kg.h, n = 6). Treatment with EUK-8, particularly at the higher dose, significantly attenuated many of the features of LPS-induced acute lung injury, including arterial hypoxemia, pulmonary hypertension, decreased dynamic pulmonary compliance and pulmonary edema. LPS caused an increase in lung tissue malondialdehyde content that was abrogated in both EUK-8-treated groups. EUK-8 treatment had no effect on circulating plasma levels of tumor necrosis factor-alpha, thromboxane B2 or 6-keto-prostaglandin F1 alpha. We conclude that EUK-8 prevents many of the manifestations of LPS-induced adult respiratory distress syndrome in pigs by detoxifying reactive oxygen metabolites without affecting the release of other important proinflammatory mediators.

Animals↗
PubMed1987

Progressive mental regression in siblings with Morquio disease type B (mucopolysaccharidosis IV B).

A brother and sister with clinical and radiological features of Morquio disease, but with atypical mental regression, are described. Leucocyte and fibroblast beta-galactosidase activity was deficient in the siblings, while N-acetylgalactosamine 6-sulphate sulphatase and neuraminidase were normal. Study of the residual fibroblast beta-galactosidase activity towards 4-methylumbelliferyl and p-nitrophenyl beta-D-galactosides indicated that the mutation resembles that in typical Morquio B disease (increased Km and similar pH maximum) rather than that in GM1-gangliosidosis. The patients have therefore been classified as having Morquio B disease with atypical mental regression rather than GM1-gangliosidosis variants with particularly severe bony abnormalities. The mutation was, however, distinct from that in Morquio B disease since residual activity towards the alternative artificial substrate 4-methylumbelliferyl-beta-D-fucoside was increased. The patients represent further examples of the heterogeneity that can result from mutation at the beta-galactosidase locus.

Bone Diseases, Developmental↗
PubMed1983

Prenatal tests for Sanfilippo disease type B in four pregnancies.

We report the prenatal diagnosis of two fetuses with Sanfilippo disease type B. In both pregnancies there were excessive amounts of heparan sulphate in amniotic fluid and the activity of N-acetyl-alpha-D-glucosaminidase was undetectable in cultured amniotic fluid cells. The predictions were confirmed by enzyme assay of cultured skin fibroblasts from the aborted fetus or the affected infant. The disorder was excluded for two other pregnancies at risk and the predictions are considered to be correct because of the normal progress of the healthy children.

Acetylglucosaminidase↗
PubMed1981

Reversal of clinical features of Hurler's disease and biochemical improvement after treatment by bone-marrow transplantation.

A one-year-old boy with type I H mucopolysaccharidosis (Hurler's disease) was given a bone-marrow transplant (BMT) from his mother in an attempt to replace the deficient enzyme, alpha-L-iduronidase (iduronidase). These is definite evidence of engraftment, the enzyme activity of the recipient's leucocytes reaching heterozygote levels within 37 days of the BMT. Graft-versus-host disease (GVHD) developed but was partially controlled by steroids. From 3-4 months after graft until the present (13 months after the graft) iduronidase activity has been present in the serum and the urine and there has been evidence of considerable degradation of glycosaminoglycans excreted in the urine. The hepatosplenomegaly has disappeared, corneal clouding has cleared, and deterioration in the child's development seems to have been arrested.

Aminoacridines↗
PubMed1981

Correct prenatal diagnosis of a Hurler fetus where amniotic fluid cell cultures were of maternal origin.

Contamination of amniotic fluid cell cultures by maternal cells can be expected to lead to misdiagnosis of fetal genotype in 0.1 to 0.5/100 cultures, when assays are carried out directly on cultured cells. Chemical analysis of the cell-free amniotic fluid supernatant may overcome this source of error and has the added advantages of speed and independence from amniotic cell culture failure. We describe a pregnancy at risk for Hurler's disease where amniotic cells cultured at amniocentesis had a female karyotype and an alpha-iduronidase activity towards both phenyl and 4-methylumbelliferyl substrates at the lower end of the normal range, suggesting a heterozygous fetus. An affected fetus was predicted, however, because of a high concentration of dermatan sulphate in the amniotic fluid. The discrepancy between these findings was shown to be due to maternal cell contamination of amniotic fluid cell cultures by the birth of a male infant with Hurler's disease.

Amniotic Fluid↗
PubMed1980

Fibroblast alpha-galactosidase A activity for identification of Fabry's disease heterozygotes.

The identification of female carriers of Fabry's disease is important for genetic counselling since prenatal diagnosis of affected fetuses is possible. The activities of either total alpha-galactosidase or alpha-galactosidase A in cultured fibroblasts were similar in Fabry carriers and controls and cannot therefore be used for carrier detection. Better discrimination between carriers and controls was found when total alpha-galactosidase activity was expressed as a ratio to beta-galactosidase activity, but overlap still occurred. However, there was complete discrimination between the ratio of alpha-galactosidase A to beta-galactosidase in cultured fibroblasts from five carriers of Fabry's disease and either 11 controls, seven hemizygote affected males or two of their female relatives.

Adult↗
PubMed1979

Prenatal diagnosis of Farber's disease.

Two pregnancies at risk for Farber's disease were monitored with amiocentesis at 15 and 16 weeks' gestation. In the first pregnancy tested, cultured amniotic-cell ceramidase activity was 7.8% of the control mean and an affected fetus was predicted. The pregnancy was terminated at 22 weeks' gestation and the diagnosis was confirmed by the demonstration of considerably elevated renal and hepatic ceramide concentrations and severe reduction of ceramidase activity in fetal brain and cultured fibroblasts. In the second pregnancy tested, cultured amniotic-cell ceramidase activity was within the control range, and the prediction of an unaffected fetus was confirmed in the newborn.

Amidohydrolases↗