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Biomedical subjects

J G Hall

Publications and source records attributed to J G Hall.

At least 253 records · Page 14Linked to original sources
PubMed1981

Short-limbed dwarfism: ultrasonographic diagnosis by mensuration of fetal femoral length.

The femoral lengths of 70 normal fetuses, five short-limbed dwarfs, and two additional normal fetuses at risk for dwarfism were measured employing linear array real-time (rapid B-scan) ultrasonographic systems. Early results indicate that prenatal diagnosis of short-limbed dwarfs can be accomplished by this technique, in some instances early enough to allow parents to consider elective abortion. The data also indicate fundamental differences in the growth pattern of certain dwarf syndromes.

Dwarfism↗
PubMed1981

Receptors for the excitatory amino acids.

1. Pharmacological evidence indicates that excitatory amino acid receptors are of three types: (a) glutamate/quisqualate-activated, GDEE-antagonized, (b) NMDA-activated, D alpha AA-antagonized, and (c) kainate-activated with no known specific antagonist. 2. Some agonists can activate both types (a) and (b); and other antagonists can affect more than one class of receptor. 3. The GDEE-sensitive receptors accept molecules in which the distal carboxyl-amino nitrogen distance approaches 0.2nm, while D alpha AA-sensitive receptors react with molecules in a more extended configuration. The "folded" receptor appears to have a higher affinity for its ligands in cases where molecules theoretically could react with either type. 4. D-glutamate can act as an agonist at the "extended" receptor and an antagonist of the "folded" type. 5. Kainate receptors appear also to be "extended" receptors perhaps physiologically activated by glutamate, but differ from those which are blocked by D alpha AA. We are grateful to Drs. J. Davies and J.C. Watkins for sending us manuscripts prior to their publication. H. McL is supported by the Medical Research Council of Canada.

2-Aminoadipic Acid↗
PubMed1980

X-linked cutis laxa: defective cross-link formation in collagen due to decreased lysyl oxidase activity.

We studied several members of a family with an X-linked form of cutis laxa; the affected males have mild skin laxity, a characteristic facies, skeletal abnormalities, structural abnormalities of the genitourinary tract, and low serum copper levels. The activity of lysyl oxidase, a copper-dependent enzyme involved in cross-link formation in collagen, was decreased in skin-biopsy specimens (13 to 26 per cent of normal) and in culture medium from cells to two affected males (15 to 20 per cent of normal). Immunoreactive lysyl oxidase from skin of both patients was virtually undetectable by immunodiffusion assay. The amounts of lysyl-derived aldehydes (the product formed in collagen and elastin by lysyl oxidase) and of cross-links formed from these products were decreased in dermal fibroblasts in culture. Collagen extractability from these cells was increased in culture. These findings suggest that lysyl oxidase deficiency provides the biochemical basis of the X-linked form of cutis laxa.

Amino Acid Oxidoreductases↗
PubMed1980

Rothmund-Thomson syndrome with severe dwarfism.

Two patients had severe dwarfism and limb anomalies, but also had other clinical characteristics of the Rothmund-Thomson syndrome, including characteristic skin changes, abnormal hair growth, sensitivity to sunlight, defective nails and teeth, and juvenile cataracts. We emphasize that this diagnosis should be considered in any patient with extremely short statute, associated skeletal anomalies, and an early onset of typical cutaneous changes.

Adult↗
PubMed1980

Lip pits, cleft lip and/or palate, and congenital heart disease.

Three individuals in whom lip pits and cleft lip and/or cleft palate were found in association with congenital heart disease are described. These individuals did not have the characteristics of previously delineated syndromes in which lip pits occur, including Vanderwoude syndrome, popliteal pterygium syndrome, and orodigitofacial dysostosis. Literature review failed to show any previously reported cases in which pits were observed in association with congenital heart disease.

Cleft Lip↗
PubMed1980

Effect of skin painting with oxazolone on the local extravasation of mononuclear cells in sheep.

A characteristic feature of the induction of cell-mediated delayed hypersensitivity reactions by chemicals such as oxazolone is the enlargement of lymphocyte traffic areas in the paracortices of regional lymph nodes. In sheep oxazolone is a powerful immunogen but the cellular changes in lymph efferent from nodes draining areas of oxazolone-painted skin do not differ significantly from responses to conventional antigens. Specific complement-binding antibodies appear in the plasma of sensitized sheep, which respond to secondary challenges with an immediate Arthus reaction. In studies of peripheral lymph from areas of skin painted with oxazolone the number of mononuclear cells in the lymph increased 10--50-fold two days or so after skin painting. Most of these cells were small lymphocytes lacking surface immunoglobulin (presumptive 'T' cells). This big increase in lymphocyte traffic through the skin may be a consequence of the binding to local structural proteins of myriads of oxazolone epitopes. If so, and bearing in mind the large doses of immunogen used in experiments on mice, it is easy to envisage how the traffic areas of lymph nodes expand and become congested with lymphocytes after being flooded with a highly immunogenic and reactive chemical like oxazolone. Whether this is relevant to the induction of cell-mediated immunity is unknown.

Animals↗
PubMed1980

Genetic counseling for adoptees at risk for specific inherited disorders.

We present 5 cases in which family history showed that a child given up for adoption some years earlier was at 50% risk for inheritance of Huntington disease, myotonic dystrophy, myotonic dystrophy, Fabry disease, von Willebrand disease, and Waardenburg syndrome, respectively. In all cases, the biological mothers (the probands) requested that the genetic counseling provided for them and their children be shared with the adoptive family. The decision whether or not to seek out the adoptee was based upon explicit assessment of the potential benefits and potential difficulties involved in contacting the adoptive family and attempting to provide genetic counseling. We have formulated some recommendations for dealing with other families with similar separation of relatives by adoption on the basis of these experiences.

Adoption↗
PubMed1980

Endocardial fibroelastosis, neurologic dysfunction and unusual facial appearance in two brothers, coincidentally associated with dominantly inherited macrocephaly.

We describe two brothers with endocardial fibroelastosis, unusual facial appearance, and cryptorchidism. The surviving brother has mental retardation, seizures and possible hypothalamic dysfunction. Both brothers have a head size greater than two standard deviations above normal; this appears to be related to superimposed presence of coincidental autosomal dominant macrocephaly in this family.

Cryptorchidism↗
PubMed1980

Gardner syndrome and periampullary malignancy.

In a family with colonic polyposis and the typical associated findings of Gardner syndrome (osteomas and soft-tissue tumors), two and possibly four of the affected members developed periampullary malignancy. A review indicates that individuals with Gardner syndrome may have a 100- to 200-fold increased risk of developing periampullary carcinoma when compared to the general population. While certain families and certain individuals (those with other duodenal involvement, males and those with all of the characteristics of Gardner syndrome expressed) may be most susceptible, all patients with Gardner syndrome should be periodically endoscopically evaluated for the presence of upper gastrointestinal tract disease.

Adolescent↗
PubMed1980

Congenital hypothalamic hamartoblastoma, hypopituitarism, imperforate anus and postaxial polydactyly--a new syndrome? Part I: clinical, causal, and pathogenetic considerations.

We report on six infants with a neonatally lethal malformation syndrome of hypothalamic hamartoblastoma, postaxial polydactyly, and imperforate anus. Some, but not all, patients had laryngeal cleft, abnormal lung lobulation, renal agenesis and/or renal dysplasia, short 4th metacarpals, nail dysplasia, multiple buccal frenula, hypoadrenalism, microphallus, congenital heart defect, and intrauterine growth retardation. The infants also had hypopituitarism and hypoadrenalism. All were sporadic cases, parents were not consanguineous, chromosomes were apparently normal. Family histories were unremarkable. There was insecticide and/or herbicide exposure in several of the cases, but no exposures were common to all 6 mothers. Five of the patients were born within an 8-month period, but all in different geographic locations. It is postulated that this is a previously apparently unreported syndrome of presently unknown cause.

Anus, Imperforate↗
PubMed1980

Congenital hypothalamic hamartoblastoma, hypopituitarism, imperforate anus, and postaxial polydactyly--a new syndrome? Part II: Neuropathological considerations.

Unusual and virtually identical hypothalamic tumors were recently studied in three unrelated neonates with a similar complex malformation syndrome. Previous reports of either the hypothalamic tumors or the syndrome as a whole have not been found. Each tumor was apparent on the inferior surface of the cerebrum and extended from the optic chiasma to the interpeduncular fossa. The tumor replaced the hypothalamus and other nuclei which originate in the embryonic hypothalamic plate; it was principally composed of cells resembling primitive, undifferentiated germinal cells. The term "hamartoblastoma" is used to designate these tumors in order to emphasize the malformational and neoplastic aspects. In addition, short olfactory tracts suggest a relation to the arrhinencephaly field defect.

Anus, Imperforate↗