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Biomedical subjects

E Beutler

Publications and source records attributed to E Beutler.

At least 379 records · Page 21Linked to original sources
PubMed1979

The biochemical genetics of the hexosaminidase system in man.

Tay-Sachs disease and related GM2 ganglioside storage disorders result from the absence of one form of hexosaminidase, HEX A. The persistence of a second major hexosaminidase isozyme, HEX B, does not protect against the lethal accumulation of GM2 ganglioside in the central nervous system. Using immunologic and biochemical techniques, it has been demonstrated that the two major isozymes of hexosaminidase, HEX A and HEX B, share a common subunit, the structure of HEX A being designated (alpha beta)n and the structure of HEX B being designated as (beta2)n. The minor isozyme, HEX S, is an alpha chain homopolymer designated (alpha2)n, and HEX C seems unrelated to the HEX A, B, S system. The structures of other minor isozymes have not been totally resolved, but HEX I1, I2, and P (which may be identical to I2) appear to represent forms of HEX B.

Enzyme Precursors↗
PubMed1979

Depletion of red cell ATP by incubation with 2-deoxyglucose.

In order to devise a more physiologic system for measuring depletion of red cell ATP levels, the effect of incubating human erythrocytes with 2-deoxyglucose has been investigated. ATP depletion proceeds very slowly at a 20 mM concentration of 2-deoxyglucose, a level which exceeds the Km of hexokinase for this substrate by more than 10-fold. However, at 160 mM concentration of 2-deoxyglucose, ATP depletion proceeds sufficiently rapidly that nearly 90% of ATP has disappeared from the red cell after 2 1/2 hr of incubation. To explain this observation, a number of additional studies were carried out. It was found that 2-deoxyglucose penetrated rapidly into red cells. Phosphorylation of 2-deoxyglucose in red cells was inhibited by both products of the 2-deoxyglucose-phosphorylating reaction, namely, 2-deoxyglucose-6-phosphate and ADP. Inhibition of 2-deoxyglucose phosphorylation was diminished at higher-than-physiologic pH levels. Red cells may be relatively rapidly depleted of ATP by incubation with 100 mM 2-deoxyglucose in a saline-phosphate-buffered medium, pH 7.8. In such rapidly depleted cells, the morphologic changes which formerly were attributed to ATP depletion do not occur.

Adenosine Triphosphate↗
PubMed1979

Transport accounts for glutathione turnover in human erythrocytes.

Human erythrocytes were incubated with 3H-glycine to label the glutathione pool. These cells were then used to determine the rate of oxidized glutathione (GSSG) transport out of erythrocytes. For 6 normal individuals, the mean transport rate was 6.7 nmole GSSG/hr/ml red cells. This transport rate would suggest a half-life of 4.7 days for the erythrocytic glutathione, which is in close agreemwnt with the observed in vivo half-life of 4 days. These data demonstrate that GSSG transport can account for the observed turnover of erythrocytic glutathione.

Biological Transport↗
PubMed1979

The storage of hard-packed red blood cells in citrate-phosphate-dextrose (CPD) and CPD-adenine (CPDA-1).

The preservation of red cells "hard packed" to a hematocrit of over 80% from blood collected in citrate-phosphate-dextrose (CPD) or CPD-adenine (CPDA-1) has been investigated. After 21 days of storage, cells that had been collected in CPD solution had consumed most or all of the available glucose and manifested markedly impaired viability after reinfusion into the normal donor. In contrast, red cells prepared from blood collected in CPDA-1, a medium containing supplementary adenine and an increased amount of glucose, maintained higher glucose and adenosine triphosphate levels and, in most instances, manifested satisfactory posttransfusion viability. We emphasize that in addition to providing longer shelf life of stored blood, CPDA-1 provides a better hard-packed red cell concentrate for transfusion at 21 days.

Adenine↗
PubMed1979

Electrophoresis of glucocerebrosidase from normal and Gaucher disease fibroblasts.

A polyacrylamide gel electrophoresis system for glucocerebrosidase has been developed. This method was used to characterize the glucocerebrosidase activity of normal and Gaucher disease fibroblasts; the residual glucocerebrosidase activity in adult Gaucher disease fibroblasts co-migrates with the activity from normal fibroblasts.

Cells, Cultured↗
PubMed1979

Erythrocyte cellular and membrane deformability in hereditary spherocytosis.

In order to determine whether the relative rigidity of the hereditary spherocytosis (HS) red cell is due to membrane rididity or merely to an altered surface/volume ratio, we investigated the deformability of resealed red cell membranes from patients with HS. Whereas the osmotic fragility of intact red cells of HS patients showed the expected increase, the osmotic fragility of resealed HS membranes was normal, thus indicating that their surface/volume ratio was normal. Measurements with an ektacytometer showed that deformability of intact HS cells was markedly diminished, whereas deformability of resealed HS membranes was normal. These findings indicate that the HS red cell membrane is not intrinsically abnormally rigid, as has been suggested, but that the lack of deformability of the erythrocyte is primarily a function of the altered surface/volume ratio.

Dextrans↗
PubMed1978

Continuous intravenous deferoxamine infusion. Treatment of secondary hemochromatosis in adults.

Adult patients with chronic iron overload were given oral ascorbic acid and continuous intravenous infusions of deferoxamine mesylate. The dosage of deferoxamine mesylate was altered every 48 hours from 1 g/sq m/24 hr to 2 or 4 g/sq m/24 hr. The average iron mobilization was 55.6 mg per day at the 1 g/sq m/24 hr dosage level, 78.6 mg every 24 hours at the 2 g/sq m/24 hr dosage level, and 90.1 mg every 24 hours at the 4 g/sq m/24 hr dosage level. Iron mobilization was undiminished when successive 14-day courses of deferoxamine separated by six-week intervals were administered.

Administration, Oral↗