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C Starr

Publications and source records attributed to C Starr.

17 recordsLinked to original sources
PubMed2001

Hypothetical fears and quantitative risk analysis.

Hypothetical fears are concepts, not quantities. Their conceptual nature makes impractical conventional quantitative risk analyses (QRA) based on benefit/cost/risk, so they become an unmeasured influence in national decision making. The decision process involves two steps, the Analytic Stage (QRA based) and the Priority Stage (resource allocation competition). This article suggests that a quantitative estimate of the social cost of fear reduction to acceptable levels be used as a surrogate QRA input to the Priority Stage.

Journal Article↗
PubMed2000

Powerful reactions

Explore the source record for details and available documents.

Journal Article↗
PubMed2000

The ultimate uncertainty--intergenerational planning.

The philosophic and practical aspects of intergenerational planning for a 50-100-year time frame are reviewed, with recognition of its speculative quality. Society's near term choice of future physical pathways based on comparative quantitative benefit/cost/risk analyses of alternatives is usually modified by the intervention of a variety of time-dependent, nontechnical value systems. Further, the continuous competition among society's disparate technical systems, capital investment choices, and planning objectives all contribute to the uncertainty of the intergenerational outcome of any plan. Nevertheless, the quantitative planning process provides an essential base. Benefit/cost/risk projections are discussed for both the case with a historical database and the case without such a historical base. The end-objectives and continuous nature of such benefit/cost/risk analyses are described.

Journal Article↗
PubMed1999

Effect of methylene blue, indigo carmine, and Renografin on human sperm motility.

OBJECTIVES: To evaluate the effect of commonly used intraoperative vasography and tissue staining agents, indigo carmine, methylene blue, and Renografin, on sperm motility. METHODS: Semen from 20 healthy men was obtained after 2 to 4 days of abstinence. Sperm motility was initially evaluated in each specimen. Standard solutions of indigo carmine, methylene blue, and Renografin-60 were diluted 2x and 4x with lactated Ringer's solution. Equal aliquots of sperm were mixed with undiluted and diluted drugs, and sperm motility was assessed. RESULTS: Initial mean sperm motility was 70.3%+/-3.0%. Undiluted methylene blue and Renografin severely depressed sperm motility to 1.1%+/-0.5% and 2.3%+/-0.7%, respectively (P <0.05). Diluted methylene blue depressed motility to 4.9%+/-1.8% and 11.2%+/-3.0% (P < 0.05). Diluted Renografin depressed motility to 25.1%+/-4.1% and 55.3%+/-3.3% (P < 0.05). Although undiluted and 2x-diluted indigo carmine moderately decreased sperm motility (48.9%+/-3.2% and 61.7%+/-3.0%, P < 0.05), 4x-diluted indigo carmine had minimal effect on sperm motility (67.3%+/-2.8%, P > 0.05). Lactated Ringer's solution had no effect on sperm motility. CONCLUSIONS: We found a severe, immediate reduction in sperm motility after exposure to undiluted standard solutions of methylene blue and Renografin. Dilution of Renografin significantly decreased its negative impact on the sperm motility, whereas the adverse effect of methylene blue remained fairly constant even with increasing dilution. Sperm motility should be assessed prior to application of these agents. Sperm should be aspirated for immediate use and/or cryopreservation prior to the use of these agents. Indigo carmine may be safely used as a tissue stain or vasography agent with a minimal effect on sperm motility in dilutions of 4x and higher.

Adult↗
PubMed1999

Metabolic and genetic determinants of HDL metabolism and hepatic lipase activity in normolipidemic females.

The metabolic and genetic determinants of HDL cholesterol (HDL-C) levels and HDL turnover were studied in 36 normolipidemic female subjects on a whole-food low-fat metabolic diet. Lipid, lipoprotein, and apolipoprotein levels, lipoprotein size, and apolipoprotein turnover parameters were determined, as were genetic variation at one site in the hepatic lipase promoter and six sites in the apolipoprotein AI/CIII/AIV gene cluster. Menopause had no significant effect on HDL-C or turnover. Stepwise multiple regression analysis revealed that HDL-C was most strongly correlated with HDL size, apolipoprotein A-II (apoA-II), and apolipoprotein A-I (apoA-I) levels, which together could account for 90% of the variation in HDL-C. HDL size was inversely correlated with triglycerides, body mass index, and hepatic lipase activity, which together accounted for 82% of the variation in HDL size. The hepatic lipase promoter genotype had a strong effect on hepatic lipase activity and could account for 38% of the variation in hepatic lipase activity. The apoA-I transport rate (AI-TR) was the major determinant of apoA-I levels, but AI-TR was not associated with six common genetic polymorphism in the apoAI/CIII/AIV gene cluster.A simplified model of HDL metabolism is proposed, in which A-I and apoA-II levels combined with triglycerides, and hepatic lipase activity could account for 80% of the variation in HDL-C.

Adult↗
PubMed1998

Structural determination of oligosaccharides from recombinant iduronidase released with peptide N-glycanase F using fluorophore-assisted carbohydrate electrophoresis.

The lysosomal storage disorder mucopolysaccharidoses I (MPS I) is caused by a deficiency in the production of alpha-L-iduronidase. Recently, a recombinant alpha-L-iduronidase has been produced in Chinese hamster ovary (CHO) cells. It is thought that for alpha-L-iduronidase to be correctly targeted to the lysosomal vesicle a particular oligosaccharide make-up must be present, and characterization of the carbohydrates is critical. Oligosaccharides from alpha-L-iduronidase were analyzed using fluorophore-assisted carbohydrate electrophoresis (FACE). The FACE system uses polyacrylamide gel electrophoresis to separate, quantify, and determine the sequence of oligosaccharides released from glycoproteins. Asparagine-linked oligosaccharides were released from alpha-L-iduronidase using the enzyme peptide N-glycanase F (PNGase F). Released oligosaccharides were labeled with a fluorophore at the reducing termini by reductive amination. A total of nine bands were sequenced from the released pool of oligosaccharides. The pool of fluorescently labeled oligosaccharides was then electrophoresed in preparative gels and each band individually excised and extracted. Isolated bands were treated with a series of exoenzymes to determine the sequence of monosaccharides that make up a particular oligosaccharide. A total of eighteen different oligosaccharides were identified from the original pool of oligosaccharides. A majority of the oligosaccharides, over 73%, were found to be of the sialylated complex type. Four of the oligosaccharides were phosphorylated, making up approximately 11% of the carbohydrate pool, and the remaining 15% were of the oligomannose type.

Amidohydrolases↗
PubMed1995

Capillary and slab gel electrophoresis profiling of oligosaccharides.

Capillary electrophoresis with laser-induced fluorescent detection, a one-dimensional version of the well-established planar analytical method of polyacrylamide gel electrophoresis, has been proven to be a powerful new microanalytical method for profiling complex carbohydrates. In this paper a comparison is presented between the planar high concentration polyacrylamide gel electrophoresis method and capillary electrophoresis of different carbohydrates with respect to performance and efficiency. N-Linked oligosaccharides were released from several glycoproteins, including fetuin, human immunodeficiency virus (HIV) envelope recombinant glycoprotein (GP-120), alpha 1-acid glycoprotein and ribonuclease B, using recombinant peptide-N-glycosidase F (PNGase F). Both separation methods involve labeling of the released carbohydrates at the reducing end with the fluorescent dye, disodium 8-amino-1,3,6-naphthalene trisulfonate (ANTS). Fluorophore labeling was followed by separation of the labeled oligosaccharides either by high concentration polyacrylamide gel electrophoresis or capillary electrophoresis.

Animals↗
PubMed1992

Education for industrial ecology.

The societal issues relevant to the subject of industrial ecology call for the participation of broadly educated engineers who can integrate their technology with the social, political, environmental, and economic aspects of its applications. This increase in the responsibility of traditional engineering to include the end-use, obsolescence, and disposition of technical products signals a new era for engineering education.

Journal Article↗
PubMed1983

Dietary fiber decreases cholesterol and phospholipid synthesis in rat intestine.

The effects of fiber ingestion on the incorporation of oleic acid into triglyceride and lecithin, acetate incorporation into cholesterol, and monosaccharide and amino acid transport were determined in rat intestine. Prolonged pectin (10% by weight) ingestion caused a decrease in jejunal and ileal cholesterol synthesis (33% and 52%, respectively). Pectin ingestion reduced cholesterol synthesis by 60% in ileal crypt cells, but did not affect cholesterol synthesis in the jejunal or ileal villus cells or in jejunal crypt cells. Cholesterol synthesis in isolated crypt cells was markedly less than in isolated villus cells. Prolonged ingestion of a fiber-free diet supplemented with either cellulose or pectin (10% and 5% by weight, respectively) decreased jejunal lecithin glucose and leucine absorption but did not affect jejunal triglyceride synthesis.

Acetates↗
PubMedDate not supplied

Carotid artery stump pressure: its variability when measured serially.

At 189 operations in 174 patients, carotid artery stump pressure (CSP) was measured serially to determine variability during carotid endarterectomy with eucarbic general anesthesia. Overall, 34 of 174 (19.5%) had significant variation in CSP which would have affected selective use of a bypass shunt based on CSP criteria. In those with CSP initially below 50 torr, 26 of 76 (34%) rose above 50 torr even, though systemic pressure was constant or declined. Eight of 113 pts (7%) with initial CSP equal to or above 50 torr subsequent had CSP below 50 torr. CSP did not vary as a function of age, sex, intracranial disease judged by biplanar arteriography, or contralateral carotid stenosis but did vary with preoperative status. Asymptomatic patients had CSP above 50 torr in a high proportion of cases, 24 of 27 (89%) unlike those with TIA, 72 of 116 (62%) or prior stroke, 17 of 31 (54%) (P = 0.003). We conclude that carotid stump pressure is variable in many patients which may account for some of the conflicting observations on the need for shunts in carotid surgery.

Blood Pressure↗