Harry Harris

Adenosine deaminase polymorphism in man

1 A new and specific method for the study of adenosine deaminase isozymes is described. 2 Examination of red‐cell lysates has revealed three genetically determined electrophoretically different ADA phenotypes: ADA 1, ADA 2–1 and ADA 2. 3 Family studies indicate that these phenotypes are determined by two alleles, ADA1 and ADA2 at an autosomal locus. 4 Preliminary population data suggest that ADA2 has a frequency of about 0.06 in European, 0.04 in Negroes and 0.11 in Asiatic Indians. 5 The behaviour of the ADA isozyme pattern on storage or after treatment with thiol reagents suggests the occurrence of reactive sulphydryl groups in the enzyme molecules.

Differential inhibition of human serum cholinesterase with fluoride: recognition of two new phenotypes.

IT has been shown that individuals excessively sensitive to the drug suxamethonium have a reduced level of serum cholinesterase activity, and that this peculiarity is genetically determined1. It has also been found that the cholinesterase present in the serum of such suxamethonium-sensitive individuals is qualitatively different from that occurring in most normal people2. This difference can be most simply demonstrated by determining the degree of inhibition produced by certain anticholinesterase substances. For example, using 5 × 10−5 M benzoylcholine as substrate and 10−5 M dibucaine as inhibitor under standard conditions, the enzyme in most normal sera shows about 80 per cent inhibition, while that in sera from suxamethonium-sensitive individuals shows only about 20 per cent inhibition. The percentage inhibition obtained under these conditions has been called the dibucaine number (D.N.) and this appears to be a constant characteristic for any one individual3.

Genetical studies on a new variant of serum cholinesterase detected by electrophoresis.

1. At least four distinct zones with properties of serum cholinesterase (pseudocholinesterase) may be demonstrated by starch gel electrophoresis of normal serum or plasma. These have been called C1; C2, C3 and C4, and they have been observed in all the sera or plasmas studied. Most of the serum cholinesterase activity present is attributable to C4. C1( C2 and C3 are only minor components. In paper electrophoresis at pH 8·6, C1, C2, C3 and C4 have essentially the same mobility. Since they are well separated at this pH in starch gel electrophoresis it seems likely that they may represent a series of polymers of increasing molecular weight C1 < C3 < C4. C2 has a slightly greater mobility than C1, C3 and C4 in paper electrophoresis at pH 8·6.

A study of urine proteins by two-dimensional electrophoresis with special reference to the proteinuria of renal tubular disorders

Abstract The proteins in the urines of 118 patients with proteinuria have been examined by two-dimensional electrophoresis using a combination of the paper and starch gel methods. The existence of a type of urine protein pattern which is particularly associated with diseases involving non-specific renal tubular dysfunction has been confirmed. This “tubular” proteinuria is distinguished by the presence of characteristic proteins of unusual mobility which could not be detected by the present methods in either serum or in other types of proteinuria. The possible origin of the “tubular” proteins is discussed.

Differential inhibition of the serum cholinesterase phenotypes by solanine and solanidine

Solanine and solanidine inhibit differentially the serum cholinesterase of individuals of the ‘usual’, ‘intermediate’, and ‘atypical’ phenotypes. The effect is similar to that obtained with dilute aqueous extracts of potato.

The serum cholinesterase variants. A study of twenty-two families selected via the 'intermediate' phenotype.

Serum cholinesterase dibucaine numbers were determined in 119 individuals from 22 families selected through propositi with the ‘ intermediate’ phenotype as denned by dibucaine number. Nineteen of the spouses and 78 of the children of the propositi were studied.

Studies on the separate isozymes of red cell acid phosphatase phenotypes A and B. II. Comparison of kinetics and stabilities of the isozymes.

Comparisons were made of some of the properties of the isozymes of types A and B red cell acid phosphatase. In each case, the more anodal isozyme had a higher pH optimum and a lower Km for ^‐nitrophenyl phosphate. Thermostability tests indicated that this isozyme was also the least stable in both types. Evidence is also presented which suggests that the two isozymes within one type are interconvertible.

Red cell glucose‐6‐phosphate dehydrogenase activity in individuals with abnormal numbers of X‐chromosomes

Red cell glucose‐6‐phosphate dehydrogenase (G‐6‐PD) activity was measured in fourteen XXX, eleven XX Y, three XO individuals, four individuals who were 17 but had testicular feminization, and in appropriate male and female controls. No evidence for any quantitative relationship between the number of X‐chromosomes present and the level of red‐cell G‐6‐PD activity was observed. Since G‐6‐PD is known to be determined by at least one gene locus in the X‐chromosome, these results in agreement with others imply complete dosage compensation.

Double Beta-Lipoprotein: A New Genetic Variant in Man

A β-lipoprotein variant, in which two bands appear after electrophoresis, has been found in three generations of a family. The variant, immunologically also a β-lipoprotein, differs in molecular size, density, and charge fromn normal β-lipoprotein. Individuals showing the variant appear to be heterozygotus for an ulncommon multant gene.

Haptoglobins in cerebrospinal fluid

Abstract Haptoglobin was detected more readily in starch gel electrophoresis of C.S.F. concentrates from individuals of haptoglobin type 1-1 than from those of types 2−1 and 2-2. The haptoglobin pattern was the same as that observed in serum in type 1-1 but in types 2−1 and 2-2 the proportion of the different bands was changed as there was relatively more of the faster moving and presumably lower molecular weight components. If the haptoglobin in C.S.F. is derived from serum these results suggest that the lower molecular weight haptoglobin components gain entry into the C.S.F. relatively more easily than those of higher molecular weight.