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Biomedical subjects

F H Allen

Publications and source records attributed to F H Allen.

At least 19 recordsLinked to original sources
PubMed1991

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.

Computers↗
PubMed1979

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.

Abnormalities, Multiple↗
PubMed1978

Cystic neoplasms of the pancreas: new angiographic and ultrasonographic findings.

Cystic neoplasms of the pancreas (cystadenoma, cystadenocarcinoma) are rare tumors. Early diagnosis and differentiation from other pancreatic lesions are essential for appropriate management. Pancreatic angiography and gray scale ultrasonography facilitate rapid, accurate diagnosis and proper surgical therapy. In a 7 year period, eight patients were studied (one cystadenoma, seven cystadenocarcinoma); five had selective visceral angiography and six underwent abdominal ultrasonography. The ultrasonographic characteristics of these neoplasms and some new angiographic findings are presented. The sonographic findings for cystadenocarcinoma were similar to those of cystadenoma.

Adult↗
PubMed1977

Biochemical genetics of MN.

Quantitative hemagglutination studies of the MN-hemizygous (M/-) patient and his family reported by German et al. are given together with data on the electrophoretic mobility of their red cells. These results, and those obtained on the cells of a donor of the MU phenotype (MU=M+N-S-s-U+); Mu=M+N-S-s-U), demonstrate a series of shortcomings in the current 'precursor transferase' theory of the biochemical genetics of MN antigens. Another theory is proposed, according to which the effects of the MN genes take place exclusively in the protein part of the glycopeptide. The MN proteins would carry acceptor sites for the antigenic oligosaccharides which are put together by enzymes genetically independent of MN. In M glycoproteins, the acceptor sites are close to each other, in doublets, while in N they are all separate. This model is shown to apply successfully to several difficult problems in MN.

Electrophoresis↗
PubMed1977

Anti-Lu14: a Lutheran antibody defining the product of an allele at the Lu8 blood group locus.

A 'new' Lutheran-related antibody, named anti-Lu14, reacts with approximately 2.4% of random bloods. Red cells of the rare Lu:-8 phenotype are Lu:14. The data indicate, with a high probability, that the Lu 14 antigen is a product of an allele of Lu8 and that Lu14 and Lu8 comprise a third pair of alleles at the Lutheran locus. Red cells of the original Sw (a+) propositus are Lu:14. By coincidence, he has inherited two low-incidence genes. This observation may explain the discrepancy in different families concerning a possible relationship between Swa and Lutheran. Pedigree information now suggests that Swa is not a Lutheran gene.

Alleles↗
PubMed1976

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.

Diabetes Mellitus, Type 1↗
PubMed1976

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.

ABO Blood-Group System↗
PubMed1976

Rhmod, a second kindred (Craig).

Three Rhmod siblings were found to have identical Rh: w1, w2, -3, -4, w5 (see article) phenotypes. All had stomatocytic hemolytic anemia. On quantitative hemagglutination studies, as well as on hand tests, all Rh antigens were not equally depressed. Rh17 (Hr0, 'not D') and Rh29 (RH, 'total Rh') were both normal. Rh5 (hr", e) was only slightly depressed. Rh25 (LW) had 50% of the expression expected in normal Rh:-1 cells. Rh1 (Rh0, D), Rh13 (RhA), Rh14 (RhB), Rh15 (RhC), and Rh16 (RhD), were severely depressed. Rh2 (rh', C) was depressed, while Rh7 (rhi, Ce) was absent. Both Rh19 (hrS) and Rh31 (hrB) were depressed. Rh12 (rhG, G) was distinctly depressed, scoring considerably less than rGrG red cells. The unrelated parents, the child of the proposita, and some siblings of each parent showed lessened depression of Rh antigens without displaying the consistent pattern that might be expected from a presumed single suppressor gene. Absence of a consistent pattern may have resulted from differing Rh genotypes, but a frequently observed depression involved Rh14, Rh15, and Rh16 (RhB, RhC, and RhD) without an effect on either Rh1 (RH3 or D) or Rh13 (RhA).

Female↗
PubMed1976

Linkage relationships of the loci of the major histocompatibility complex in families with a recombination in the HLA region.

A number of families with an established recombination in the major histocompatibility complex has been investigated for markers known to be coded by genes of this linkage group. The results provide further data on the relative position of the loci for HLA-A, HLA-B, HLA-C, HLA-D, Bf, Chido, Rodgers and PGM3 on chromosome 6. A positive lodscore for linkage between HLA and blood group P was found; lodscores between HLA and nineteen other markers were negative.

Chromosome Mapping↗
PubMed1976

Monozygotic twins discordant for sex.

A pair of monozygotic, adolescent twins is discordant for sex. The phenotypic female twin has chromosome constitution of 46, XY/45, X. She displays many signs of Turner's syndrome, including typical facies, webbed neck, malformed left kidney, high plasma gonadotropins, and streak ovaries. However, her height is 154 cm which exceeds the height usually reported in Turner's syndrome. The male twin has a karyotype of 46, XY and normal sexual development. Only two other reports of pairs of monozygotic twins of opposite sex have been published.

Adolescent↗
PubMed1975

Echocardiographic observation of ventricular volume changes and swinging septal position in massive pericardial effusion.

Swinging interventricular septal position and ventricular volume changes associated with respiration were studied in a patient with massive uremic pericardial effusion and pulsus paradoxus. Inspiration was regularly associated with a posterior swinging septal position which dramatically increased right ventricular (RV) volume with a lesser change in left ventricular (LV) volume. Expiration was consistently accompanied by an anterior swing of septal position which nearly obliterated the RV with slight enlargement of the LV. The above changes produced a pendulum-like motion of the septal position as the patient breathed. This may reflect the ventricular volume changes that accompany respiration in severe pericardial effusion association with pulsus paradoxus.

Adult↗
PubMed1975

Chronic granulomatous disease and the Kell blood groups.

Fifteen antigenic determinants are known to be related to the Kell blood group. Some boys with X-linked chronic granulomatous disease have the very rare McLeod or Ko phenotype on their red cells. Serological studies of the McLeod type suggest that the weak Kell antigens that are present differ qualitatively and quantitatively from those on red cells of common Kell type. A new antigen, Kx, has been characterized and shown to be present on red cells and neutrophil leucocytes. Lack of red-cell Kx is associated with the McLeod phenotype, lack of leucocyte Kx is associated with chronic granulomatous disease.

Antigen-Antibody Reactions↗
PubMed1975

Ankylosing spondylitis in a large kindred: clinical and genetic studies.

In a kindred of 66 members spanning four generations, seven cases of ankylosing spondylitis (AS) HAVE BEEN FOUND. Four of these were in a single sibship of 13. AS was associated with HL-A27 in three of the four involved siblings, but close linkage was shown to be unlikely. Knowledge of HL-A genotype has made possible informed counseling for younger members of the sibship of 13, some of whom, as teenagers, already have back pain.

Adolescent↗