Evidence for linkage between HL-A histocompatibility genes and those involved in the synthesis of the second component of complement.

HL-A analysis of a family with C2 deficiency revealed evidence for close linkage between the C2 defect and the histocompatibility HL-A loci. The propositus was homozygous both for C2 deficiency and the HL-A haplotype 10,W18. Among seven children of three double backcross matings, no recombinants were found. The possible significance of such linkage is discussed.

The HLA system in the families of patients with juvenile diabetes mellitus.

The HLA and Bf genotypes were determined in 10 families with one or more children with JDM. A statistically significant association was found between HLA-D-identity and the chance to present JDM within a sibship. No such association was detectable with the SD antigens. A highly significant increase in the frequency of intra-HLA recombination was also found in these families.

MN blood-group locus: data concerning the possible chromosomal location.

Combined data derived from clinical, cytogenetic, and blood-grouping studies of one family suggest that the MN locus is on the long arm of either the No. 2 or the No. 4 chromosome.

NB1, a new neutrophil-specific antigen involved in the pathogenesis of neonatal neutropenia.

A new human antigen is reported which is present only on blood neutrophils. A neutrophil-specific antigen, designated NA1, has previously been identified in two unrelated families, and was shown to be involved in fetomaternal incompatibility and the development of isoimmune neonatal neutropenia in five newborns. In the present paper, a second antigen, designated NB1, is identified in four families with seven affected children. Antibodies that react with this second antigen are shown to produce selective agglutination of neutrophils but not other blood cells. They are neither absorbed by cells prepared from solid tissues nor by non-neutrophilic blood cells. By family and population studies, NB is shown to be distinct from NA, representing an independent genetic locus. 68% of the New York population are homozygous for NB1, 29% heterozygous, and 3% negative. The NB locus is shown to be independent from those of HL-A and other known leukocyte antigens. No evidence for linkage between NA, NB, and red cell antigens was obtained.

Emergency treatment of status epilepticus.

Status epilepticus occurs in more than 50,000 people in the United States each year and should be considered a neurologic emergency. A variety of drugs are used to treat status epilepticus, including i.v. benzodiazepines, phenytoin, and barbiturates. They are all short of being ideal, primarily because of difficulties with administration or associated toxicity. Fosphenytoin, a prodrug and phosphate ester of phenytoin, was developed to overcome the drawbacks associated with i.v. phenytoin. With its efficacy, safety, and ease of administration, fosphenytoin is a valuable option for the treatment of status epilepticus.

Genetic linkage analysis in primary torsion dystonia.

We studied five families, each containing two siblings affected with torsion dystonia and having phenotypically normal parents, for linkage of dystonia to 18 marker systems, including HLA. Analysis assumed an autosomal recessive mode of inheritance. Linkage was not found. Two markers, HLA and MN, were excluded from tight linkage, and evidence against tight linkage to ABO, Rh, GC, and GLO was obtained.

Deletion mapping: further evidence for the location of acid phosphatase (ACP1) within 2p23.

The human red cell acid phosphatase (ACP1) locus was assigned to region 2p23 leads to 2pter by Ferguson-Smith et al [3], more specifically to 2p23 by Hamerton et al [5]. We describe two unrelated patients with deletion of chromosome 2, with similar breakpoints in the distal portion of band p23 (del(2) (p23)). ACP1 typing in both patients revealed heterozygous BA phenotypes. Thus, we assign the locus for ACP1 to the distal portion of 2p23.

Null types of the human erythrocyte blood groups. Philip Levine award lecture.

Null types of 12 human erythrocyte blood groups are reviewed. They have helped in identifying new antigens and defining the various genetically-distinct systems. They are very valuable in identifying the antibodies in alloimmunized people and in transfusion therapy of some of these people. Fy(a-b-) erythrocytes resist invasion by malarial parasites. At least two (Rh null and the McLeod type) are responsible for congenital hemolytic disorders. Testing for K15(Kx) on neutrophils appears to be diagnostic for chronic granulomatous disease of the sex-linked recessive type.

Physical growth, sexual maturation, body image and sickle cell disease.

PURPOSE: This study assessed delays in physical growth and sexual maturation, self-esteem and body image in youth with homozygous sickle hemoglobin disease (HgbSS). METHOD: A consecutive sample of 30 subjects age 8 through 19 with homozygous sickle cell disease (hemoglobin SS) and a similar number of control subjects matched for age, race, gender and socioeconomic status and free of chronic illness were examined for height, weight and Tanner staging of sexual development. Subjects also completed the Body Cathexis Scale and Piers-Harris Self-Concept Scale. Assessments were with paired samples t-tests. RESULTS: The subjects with sickle cell disease had significantly lower weights and were shorter than matched control subjects. Sexual development (physical) was also delayed in the sickle cell subjects. The study failed to find significant differences for either body image or self-esteem. CONCLUSIONS: The latency age and adolescent subjects with sickle cell disease had significant delays in physical (height, weight, secondary sexual characteristics) maturation. The study failed to find significant differences in either self-esteem or body image between the two groups. Theoretical constructs from the literature were presented which questioned the belief that these expected delays in physical growth and sexual maturation have an adverse effect upon self-esteem and body image.

Shape information from a critical point analysis of calculated electron density maps: application to DNA-drug systems.

A computational method is described for mapping the volume within the DNA double helix accessible to the groove-binding antibiotic netropsin. Topological critical point analysis is used to locate maxima in electron density maps reconstructed from crystallographically determined atomic coordinates. The peaks obtained in this way are represented as ellipsoids with axes related to local curvature of the electron density function. Combining the ellipsoids produces a single electron density function which can be probed to estimate effective volumes of the interacting species. Close complementarity between host and ligand in this example shows the method to give a good representation of the electron density function at various resolutions. At the atomic level, the ellipsoid method gives results which are in close agreement with those from the conventional spherical van der Waals approach.

Pharmacophoric pattern matching in files of three-dimensional chemical structures: characterization and use of generalized valence angle screens.

This paper describes the use of generalized valence angles for the screening of pharmacophoric pattern searches in databases of three-dimensional chemical structures. A generalized valence angle is defined as the angle between two vectors, AB and BC, which have a common vertex B, and in which both vectors correspond to formal chemical bonds; one vector corresponds to a bond and the other to a non-bonded interaction; or both vectors correspond to non-bonded interactions. The screens are identified by a statistical analysis of the frequencies of occurrence of these angle-based features in the Cambridge Structural Database. The occurrence frequencies are discussed and shown to be explicable in terms of small, commonly occurring structural features. The effectiveness of the screens is demonstrated by an extensive series of searches for representative pharmacophoric patterns. The results are compared with those obtained from a similar series of searches using distance-based screens: The latter are found to give a better level of performance, and evidence is presented to suggest that this is due to a high degree of association between the assignments of the angle-based screens.