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Biomedical subjects

R J Gardner

Publications and source records attributed to R J Gardner.

At least 91 records · Page 5Linked to original sources
PubMed1987

The use of a DNA marker for carrier diagnosis in an X-linked disorder: Norrie's disease.

We report a family with the X-linked eye disorder Norrie's disease, in which DNA analysis enabled the distinction to be made between female carriers and non carriers. There was perfect cosegregation of the disease gene and the restriction fragment length polymorphism DXS7 which is recognised by the probe L1.28. Adding our data to those already on record, the lod score for linkage between DXS7 and Norrie's disease reaches 5.6, for a recombination fraction of 0.0. We anticipate that DNA testing will become a major investigative tool in genetic counselling.

Blindness↗
PubMed1987

Dominantly inherited dilated cardiomyopathy.

We describe a family in which there is segregating an autosomal dominant gene determining a cardiomyopathy. The pathodynamics is that of pump failure associated with dilatation of the heart, generally having an overt clinical onset from the fourth through seventh decades. Dysrhythmia is a frequent concomitant feature. There may be an associated skeletal myopathy, either producing a very mild proximal weakness or proving detectable only upon biopsy. This family is similar to other reported cases of familial dominant "idiopathic" dilated cardiomyopathy, but the nature of the heterogeneity within this category remains to be elucidated. The roles of echocardiography, cardiac biopsy, and skeletal muscle biopsy in the presymptomatic detection of the heterozygote are noted.

Adolescent↗
PubMed1986

Reconstruction of a type-B configuration monkey Sertoli cell: size, shape, and configurational and specialized cell-to-cell relationships.

A model of a stage-V monkey Sertoli cell was reconstructed from electron micrographs taken of semiserial sections. The configuration (type-B) was one in which spermatids were positioned near the lumen, their heads occupying shallow cylindrical recesses at the apical portion of the Sertoli cell. The cell volume was calculated to be 4,100 micron3, the surface area 2,400.68 micron2, and the surface-to-volume ratio 0.58:1. The reconstructed cell extended from the basal lamina to the tubular lumen and was generally of the tall columnar type although its surface contour was highly irregular. The dimensions of the cell [centripetal (68.46 micron), circumferential (18.40 micron), and longitudinal (21.63 micron)] were determined and cell surfaces designated. Relative and absolute surface areas of the reconstructed cell which faced other Sertoli cells, germ cells, basal lamina, and tubular lumen were calculated. Junctions and surface specializations were enumerated, catalogued, and depicted on diagrams of the cell surface. Where appropriate, type-A rat and type-B monkey Sertoli cells were compared and discussed. Morphometry was utilized to analyze the relative surface areas of germ cells adjoining the reconstructed cell to determine the percentage of their surface facing cellular and acellular elements, and these data were compared to data obtained for the rat.

Animals↗
PubMed1986

An association of caudal malformations arising from a defect in the "axial mesoderm" developmental field.

We have studied two newborn infants with a remarkable genital malformation, failure of urethral development with enormous bladder distension, atresia of the distal hindgut, vertebral abnormalities, and compression deformities. This is a pattern of anomalies similar to, and probably an extension of, the association of female pseudohermaphroditism and other anomalies (FPA) described by Lubinsky [Am J Med Genet 6:123-136, 1980]. We propose that its pathogenesis involves a defect expressed in mesoderm, especially caudal mesoderm. We offer some speculation on what might be its nature, with particular reference to the theory of cell surface molecules having a role in morphogenesis. We apply the concept of the developmental field to provide a clarifying perspective.

Abnormalities, Multiple↗
PubMed1986

Ring 21 chromosome: the mild end of the phenotypic spectrum.

The case is reported of a child with the karyotype 46,XY,r(21), who presented with linear growth retardation but who appears, at age 2 years 8 months, to be developing normally mentally. There is a small number of reports of mildly affected cases of r(21), and of some with an apparently completely normal phenotype. We presume a structural and functional cytogenetic heterogeneity underlies the observed phenotypic heterogeneity in the ring 21 spectrum.

Child, Preschool↗
PubMed1985

Sensory irritation potential of selected nasal tumorigens in the rat.

Several important chemicals, including formaldehyde, 1,4-dichloro-2-butene, bis-chloromethyl ether, hexamethylphosphoramide, and epichlorohydrin have been shown to produce nasal tumours in rats following repeated or continuous inhalation exposures. Some of these compounds are respiratory irritants. To determine whether there is a correlation between the ability of a chemical to produce sensory irritation and to elicit nasal tumours, the atmospheric concentration causing a 50% decrease in the respiratory rate (RD50) of male rats was determined. Three other nasal tumorigens, dimethylcarbamoyl chloride, 2,3,4-trichloro-1-butene and 1,2-ethoxy-3-phenoxypropane, were also studied. No correlation between sensory irritation potency and nasal tumorigenic potential was observed. The most potent nasal tumorigen hexamethylphosphoramide, which produces tumours in rats following 12 months' continuous exposure to 50 ppb, failed to cause any decrease in respiratory rate when tested at 351 ppm (an aerosol exposure level which exceeds atmospheric saturation by approximately ten times).

Animals↗
PubMed1983

Duplication 8q syndrome due to familial chromosome ins(10;8)(q21;q212q22).

We describe a kindred in which an ins(10;8)(q21;q212q22) chromosome rearrangement has been segregating for at least four generations. The risk for balanced carriers to have offspring with duplication of 8q212 leads to 8q22 is about 0.31. Individuals with unbalanced chromosomes are mildly to moderately mentally retarded and have a similar unusual appearance. Other manifestations include highly arched or cleft palate (8/9), micrognathia (6/9), sloped shoulders (4-6/9), convulsions (4/9), camptodactyly (3/9), pectus excavatum (2/9), elbow contractures (1/9), and postaxial polydactyly (1/9). The appearance and habitus resemble the mosaic trisomy 8 syndrome, although other anomalies of mosaic trisomy 8, such as vertebral, patellar, and renal defects, were not demonstrated.

Abnormalities, Multiple↗
PubMed1983

The fragile X chromosome in a large Indian kindred.

A large Indian kindred in which the fragile X chromosome is segregating has been investigated in Cape Town. Eight male hemizygotes and four female heterozygotes were mentally retarded. There is suggestive evidence that one deceased male of reportedly normal intelligence may have been a hemizygote. The existence of the fragile X syndrome in a number of different ethnic groups supports the contention that the gene controlling the phenotype and the fragile site are the same, or at least overlap.

Adolescent↗