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Biomedical subjects

R E Ferrell

Publications and source records attributed to R E Ferrell.

At least 325 records · Page 18Linked to original sources
PubMed1982

Oculocutaneous albinoidism as a manifestation of reduced neural crest derivatives in the Prader-Willi syndrome.

Nine patients with Prader-Willi syndrome (five female and four male; one Oriental and eight white), all of whom had interstitial deletions of the proximal long arm of one chromosome 15 (q11-q13) were found to have decreased tyrosinase activity in isolated hair bulbs. As infants, all patients had light hair and skin coloring, both of which darkened with age. Light and electron microscopic analysis of skin and hair bulbs disclosed a reduced number of melanocytes in the basal epidermis and hair bulbs. Each patient demonstrated decreased pigmentation of the iris stroma, which was accentuated peripherally and manifested clinically as iris translucency. There was no foveal hypoplasia, nystagmus, or photophobia, and ocular function was normal. Oculocutaneous albinoidism is thus a component of del(15q) Prader-Willi syndrome with reduction of melanocytes of neural crest origin (skin, hair, and iris stroma) and retention of normal retinal and iris pigment epithelia of neuroectodermal origin.

Adolescent↗
PubMed1982

Variable expressivity of autosomal dominant anterior segment mesenchymal dysgenesis in six generations.

Of 58 members in a six-generation family with anterior segment mesenchymal dysgenesis with variable expressivity, 21 of 35 members (60%) at risk were affected. Of the 15 living affected family members, nine (60%) had visual acuities of 6/12 (20/40) or better in at least one eye, five (33%) had visual acuities between 6/15 and 6/60 (20/50 and 20/200) in at least one eye, and one (7%) had a visual acuity of less than counting fingers at one foot in both eyes. All nine affected patients who underwent slit-lamp examinations had corneal abnormalities with and without synechiae. All 15 affected patients also had cataracts, and three of the 15 (20%) had optic nerve abnormalities. In a corneal button from the severely affected proband, Descemet's layer and endothelial cells were absent even in the periphery. Other corneal and lenticular changes were secondary to the primary endothelial defect. Anterior segment mesenchymal dysgenesis in this family appeared to be caused by an aberration of the first wave of mesenchyme from the rim of the optic cup.

Adolescent↗
PubMed1982

Familial rheumatoid arthritis: a kindred identified through a proband with seronegative juvenile arthritis includes members with seropositive, adult-onset disease.

Segregation of chromosome #6 markers has been studied in a large family, identified by a proband with seronegative, juvenile-onset rheumatoid arthritis, which contains four other individuals with adult-onset rheumatoid arthritis (RA). Two of the adult-onset patients have classical seropositive RA. Sera from two healthy members of this family also contain rheumatoid factors (RF). Six family members had crossovers in the short arm of chromosome #6. Three individuals with recombinants between HLA-B and HLA-D were identified; three others had identifiable crossovers between HLA-D and GLO (Glyoxylase 1). Linkage analysis suggested that susceptibility to RA in this family was influenced by a dominant gene located centromeric to HLA-B. The highest lod score (1.64) was obtained for linkage to GLO at a recombination rate of zero. Inheritance of specific chromosome #6 or Gm immunoglobulin allotype markers did not appear to influence serum RF. These results agree with previous family studies which suggest that acquisition of childhood- and adult-onset RA is influenced by a common disease susceptibility gene, linked to the major histocompatibility gene complex.

Adolescent↗
PubMed1982

Wilms tumor with aniridia/iris dysplasia and apparently normal chromosomes.

Two patients with Wilms tumor, iris dysplasia (complete aniridia in one and subtle iris defects in the other), normal karyotypes, and no gene loss demonstrable by enzyme marker and direct DNA analyses are presented. The findings indicate that aniridia and less severe iris defects define a risk for Wilms tumor even in the absence of del (11p13), and that there is as yet no consistent biochemical genetic marker for the aniridia-Wilms tumor association.

Adolescent↗
PubMed1982

Effect of chronic altitude hypoxia on hematologic and glycolytic parameters.

The physiological effect of chronic exposure to altitude hypoxia on the glycolytic intermediates, adenosine triphosphate and 2,3-diphosphoglyceric acid, and the hematologic parameters, hemoglobin, hematocrit, and mean cell hemoglobin concentration, has been examined in an indigenous population, the Aymara, of the Departamento de Arica, Chile. This population normally resides at three altitudes: the coast (0-500 m), the sierra (2,500-3,500 m), and the altiplano (above 4,200 m). After isolation of altitude from other environmental factors (age, sex, body build, ethnicity, smoking, and residential permanence), an increase in 2,3-diphosphoglycerate and a decrease in adenosine triphosphate was observed. Both hemoglobin and hematocrit increased as expected, but mean cell hemoglobin concentration declined. It is proposed that a decline in the activity of a single enzyme, pyruvate kinase, can account for these observed changes and suggests a pivotal role for pyruvate kinase in the physiological adaptation to altitude hypoxia.

2,3-Diphosphoglycerate↗
PubMed1982

Anterior segment mesenchymal dysgenesis: probable linkage to the MNS blood group on chromosome 4.

Thirty-seven blood samples were analyzed for linkage from members of a single family with an anterior segment mesenchymal dysgenesis (ASMD1) with variable expressivity affecting members of at least six generations. Maximum-likelihood analysis for linkage between ASMD1 and 14 biochemical and serological markers in the family showed a probable linkage between ASMD1 and the MNS blood group on the long arm of chromosome 4 (Z = 2.36 at a recombination fraction of .09).

Chromosome Mapping↗
PubMed1981

Familial retinoblastoma and chromosome 13 deletion transmitted via an insertional translocation.

Surviving persons from a kindred in which retinoblastoma occurred over four generations, transmitted by eight unaffected individuals, underwent chromosomal analysis. The results revealed that the development of retinoblastoma was associated with a constitutional chromosome deletion del(13)(q13.1q14.5) and that the unaffected transmitting state was associated with a balanced insertional translocation. These findings indicate that predisposition to retinoblastoma may be attributed to the loss of specific genetic material and that a chromosomal mechanism may explain apparent lack of gene penetrance in certain families. The development of unilateral, and not bilateral, retinoblastoma suggests either that the chromosome deletion is different from the mutation of heritable retinoblastoma in general, or that the chromosome deletion lessens the probability of subsequent somatic carcinogenic events.

Carboxylesterase↗
PubMed1981

Autosomal dominant cone-rod dystrophy: a linkage study with 17 biochemical and serological markers.

Five generations of a family with autosomal-dominant cone-rod dystrophy (CRD) with complete penetrance have been previously studied extensively clinically. The young members of this family were reevaluated, and blood from 73 available family members was studied with 17 biochemical and serological markers. A total of 25 relatives was found to be affected. Linkage between the gene for CRD in this family and the markers studied could not be established by maximum likelihood analysis.

Adolescent↗
PubMed1981

The St. Lawrence Island Eskimos: genetic variation and genetic distance.

The Eskimos of St. Lawrence Island have been typed for genetic variation at 44 discrete genetic loci. Three private polymorphisms, at the 2,3-diphosphoglycerate mutase, peptidase B, and purine nucleoside phosphorylase loci, have been observed, which may be useful in future studies of genetic relationships between Eskimos and other circumpolar populations. Genetic distance analysis reveals a close relationship between the St. Lawrence Island Eskimos and other Eskimo populations and that the Eskimo populations form a distinct cluster from Amerindian populations. The St. Lawrence Island Eskimos appear to be more similar to Asiatic Eskimos than to other groups. Caucasian admixture in this population is estimated to be between 2 and 7%.

Alaska↗
PubMed1981

Catalase levels in patients with aniridia and/or Wilms' tumor: utility and limitations.

The gene for red blood cell (RBC) catalase has recently been mapped to 11p13, and a gene dosage effect has been demonstrated for individuals with triplication or deletion of that region. Deletion of the 11p13 band has also been associated with aniridia, with and without Wilm's tumor. We studied the RBC catalase levels in individuals without detectable chromosomal abnormalities but with aniridia, Wilm's tumor, and the combination of aniridia and Wilms' tumor, to determine whether catalase levels might provide evidence for a submicroscopic chromosomal deletion in the 11p13 region. All karyotypically normal patients were found to have normal catalase levels.

Catalase↗
PubMed1981

2,3-Diphosphoglycerate and night vision.

Recovery of night vision at altitude has been examined in relationship to changes of 2,3,diphosphoglycerate (DPG). It appears that, if DPG influences night adaptation, its effect is small. Inter-individual variability is large, both in terms of DPG and performance on the MESOP, the device used to measure dark adaptation.

2,3-Diphosphoglycerate↗
PubMed1980

Biochemical markers in a species endangered by introgression: the red wolf.

The red wolf (Canis rufus), native to much of the southeastern United States, is endangered by man's activities and by hybridization with other species of the genus Canis. The absence of diagnostic morphological markers to distinguish the red wolf from its hybrids has led to the application of the methods of biochemical genetics to this problem. The finding of a unique electrophoretically determined allele with a distribution congruent with the geographical distribution of the remaining red wolf population is reported.

Acid Phosphatase↗
PubMed1980

Variable expressivity in autosomal dominant aniridia by clinical, electrophysiologic, and angiographic criteria.

Of 39 members in a family with autosomal dominant aniridia with variable expressivity, 16 members, representing 50% (15 out of 30) of those at risk, were affected. Of these, ten of 16 (63%) had visual acuity of 6/12 (20/40) or better in at least one eye, and six of 16 (37%) had visual acuity between 6/15 (20/50) and 6/60 (20/200) in at least one eye. Affected patients had nystagmus (12, 75%), cataracts (nine, 56%), strabismus (15, 94%), amblyopia (six, 37%), corneal pannus (one, 6%) glaucoma (one, 6%), macular hypoplasia (five, 31%), and optic nerve hypoplasia (one, 6%). The good visual acuity in this family indicates that absence of iris tissue is not responsible for the decreased visual acuity usually associated with aniridia. The decreased visual acuity correlates instead with a decreased macular reflex and with a decreased electroretinogram amplitude. Affected family members have abnormal persistence of vessels in the macular region angiographically, and when sufficient iris tissue is present to be studied angiographically, there are abnormal vascular loops and leakage of dye at the pupillary border.

Adolescent↗
PubMed1980

Autosomal dominant aniridia: probable linkage to acid phosphatase-1 locus on chromosome 2.

Maximum likelihood analysis for linkage between autosomal dominant aniridia and 12 biochemical and serological markers in a single large family showed a probable linkage between autosomal dominant aniridia and the enzyme acid phosphatase-1. The presence of an autosomal dominant aniridia gene linked to acid phosphatase-1 on chromosome arm 2p and the existence of an aniridia syndrome resulting from deletion of band 13 of the short arm of chromosome 11 establishes a chromosome basis for genetic heterogeneity of aniridia phenotypes.

Acid Phosphatase↗