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Biomedical subjects

K L Jones

Publications and source records attributed to K L Jones.

At least 217 records · Page 12Linked to original sources
PubMed1986

Growth hormone deficiency in the Rothmund-Thomson syndrome.

We describe the first proven occurrence of growth hormone deficiency in an individual with the Rothmund-Thomson syndrome. This was suspected because of the patient's severely retarded growth and bone age and her failure to respond normally to growth hormone stimulation testing with l-DOPA, arginine, and growth hormone releasing factor. In addition, we have briefly reviewed other genetic and malformation syndromes that have been found associated with growth hormone deficiency. We recommend that growth hormone deficiency be considered in these syndromes, especially when the growth failure is more marked than expected.

Arginine↗
PubMed1986

A distinct lethal neonatal chondrodysplasia with snail-like pelvis: Schneckenbecken dysplasia.

We describe the clinical, radiographic, histopathologic, and ultrastructural features of a distinct neonatal lethal chondrodysplasia inherited as an autosomal recessive trait. The characteristic radiographic findings consist of flattened, hypoplastic vertebral bodies; short ribs; hypoplastic iliac bones with "a snail-like" configuration; short, broad long-bones with dumbbell-like appearance; short and wide fibula; and precocious ossification of the tarsus. Chondro-osseous histology is characteristic with hypervascularity, increased cellular density, and normal size chondrocytes with a centrally located round nucleus and absence of lacunar space. Because of the snail-like radiographic appearance of the pelvis in this disorder, we propose the name "Schneckenbecken dysplasia" (ie, German for snail pelvis).

Dwarfism↗
PubMed1986

The growth of cultured rabbit articular chondrocytes is stimulated by pituitary growth factors but not by purified human growth hormone or ovine prolactin.

Recent reports describing a direct stimulation by GH of bone and cartilage growth led us to compare the in vitro mitogenic effects of highly purified human GH and PRL and two pituitary-derived growth factors in rabbit articular chondrocytes. These preparations were tested for their ability to promote [3H]thymidine incorporation into growth-arrested monolayer chondrocyte cultures and were also assayed in cell growth experiments. The factors tested included 22,000-dalton and 20,000-dalton human GH ovine PRL, glycosylated ovine PRL, bovine pituitary fibroblast growth factor (bpFGF), and a partially purified pituitary growth factor distinct from bpFGF. We found that no significant mitogenic effect was produced by either of the human GH or PRL preparations. Both of the pituitary-derived growth factors were potent mitogens, with bpFGF active at a final medium concentration of 10 pg/ml. These studies support the large body of evidence that GH has no significant direct in vitro effect on chondrocyte growth. The very potent effects of the pituitary-derived growth factors raise the possibility that their presence in GH preparations may be responsible for the in vitro mitogenic effects attributed to these preparations.

Animals↗
PubMed1986

Release of the 22,000- and the 20,000-dalton variants of growth hormone in vivo and in vitro by human anterior pituitary cells.

Using a combination of polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and immunoblotting with antihuman GH (anti-hGH) serum, we quantitatively and independently measured the major 22,000-dalton form of hGH (hGH22K) and the 20,000-dalton form (hGH20K). This technique was equally effective in assaying cell culture media or human sera. We studied isolated human pituitary cell cultures during a 16-day incubation period with and without stimulation by GH-releasing hormone (GHRH). Under basal conditions, the cells released 2.83 +/- 0.24 (+/- SEM) microgram hGH22K/ml . day and 0.67 +/- 0.17 microgram hGH20K/ml . day. GHRH (10(-8) M) treatment resulted in stimulation of both hGH22K and hGH20K by 24 h. We also measured both hGH22K and hGH20K in the sera of normal subjects before and after an iv bolus injection of 100 micrograms GHRH. hGH20K increased as did hGH22K. Peak concentrations of both variants occurred 45 min after GHRH administration. The results of this study indicate that the combination of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting is an accurate and effective means of separately assaying hGH22K and hGH20K. We also demonstrated that primary monolayer cultures of human pituitary cells are an excellent model system for study of the secretion of these two hGH variants.

Adult↗
PubMed1986

Central nervous system anomalies associated with meningomyelocele, hydrocephalus, and the Arnold-Chiari malformation: reappraisal of theories regarding the pathogenesis of posterior neural tube closure defects.

Complete gross and microscopic neuropathological examinations of 25 children who died with meningomyelocele, the Arnold-Chiari malformation, and hydrocephalus revealed a wide range and frequency of associated central nervous system malformations. The most remarkable of these anomalies were hypoplasia or aplasia of cranial nerve nuclei (20%), demonstrable obstruction of cerebrospinal fluid flow within the ventricular system (92%), cerebellar dysplasia (72%), a disorder of migration of cortical neurons (92%), fusion of the thalami (16%), agenesis of the corpus callosum (12%), and complete or partial agenesis of the olfactory tract and bulb (8%). The anomalies associated with posterior neural tube closure defects can no longer be considered secondary, but rather must be considered part of a spectrum of malformations caused by an unidentified primary insult to the central nervous system. The frequency and pattern of brain malformations associated with neural tube defects of some children with meningomyelocele suggest that such malformations may seriously affect intellectual outcome.

Arnold-Chiari Malformation↗
PubMed1986

Vascular steal: the pathogenetic mechanism producing sirenomelia and associated defects of the viscera and soft tissues.

Dissection of the abdominal vasculature in 11 cases of sirenomelia has demonstrated a pattern of vascular abnormalities that explains the defects usually found in this condition. The common feature is the presence of a single large artery, arising from high in the abdominal cavity, which assumes the function of the umbilical arteries and diverts nutrients from the caudal end of the embryo distal to the level of its origin. The steal vessel derives from the vitelline artery complex, an early embryonic vascular network that supplies the yolk sac. Arteries below the level of this steal vessel are underdeveloped and tissues dependent upon them for nutrient supply fail to develop, are malformed, or arrest in some incomplete stage. In contrast to the prevailing view that sirenomelia arises by posterior fusion of the two developing lower limbs, these studies suggest that the single lower extremity in sirenomelia arises from failure of the lower limb bud field to be cleaved into two lateral masses by an intervening allantois.

Abnormalities, Multiple↗
PubMed1985

Natural history of the fetal alcohol syndrome: a 10-year follow-up of eleven patients.

Of the eleven children who were the first to be diagnosed as having the fetal alcohol syndrome ten years ago, two are now dead, one is lost to follow-up, and the remaining eight continue to be growth deficient and dysmorphic. With menarche, which occurred with normal timing, the female patients developed increased body fat. The mothers were all severe chronic alcoholics. Four of the eight known survivors are of borderline intelligence and have needed some remedial teaching. The other four are severely handicapped intellectually and need complete supervision outside the home. The degree of growth deficiency and intellectual handicap was directly related to the extent of craniofacial abnormalities. New features of the syndrome include dental malalignments, malocclusions, and eustachian tube dysfunction, which may relate embryologically to midface hypoplasia.

Abnormalities, Multiple↗
PubMed1985

Human brain fibroblast growth factor. Isolation and partial chemical characterization.

Fibroblast growth factor (FGF) has been purified to homogeneity from human brain by a procedure involving salt precipitation, cation-exchange chromatography, Heparin-Sepharose affinity chromatography and reverse-phase HPLC. Isolation was monitored by radioimmunoassay and/or by testing column fractions for their capacity to stimulate the proliferation of vascular endothelial cells in vitro. The amino-terminal sequence of human brain FGF was determined as Pro-Ala-Leu-Pro-Glu-Asp-Gly-Gly-Ser-Gly-Ala-Phe-Pro-. This sequence is identical to that of the amino-terminal region of bovine FGF. Additional evidence, including amino acid composition, chromatographic retention behavior, and immunoreactivity suggest that the human and bovine mitogens are very similar in structure.

Amino Acid Sequence↗
PubMed1985

Carpenter syndrome: natural history and clinical spectrum.

Recently, we evaluated three sibs with Carpenter syndrome, permitting further clinical, orthopedic, radiographic, and psychometric delineation of this disorder. All three patients were operated on for craniostenosis at or before 2 months. Although all had gross motor delay in early infancy, two had normal intelligence at 12 months and 10 years, respectively. Bony abnormalities contributed to functional impairment especially in the older children. Preaxial polydactyly of feet was present in all three affected sibs and in all other reported individuals with this condition, allowing differentiation of Carpenter syndrome from the other autosomal-recessive acrocephalopolysyndactyly syndromes.

Adolescent↗
PubMed1985

Brachmann-de Lange syndrome: evidence for autosomal dominant inheritance.

We have evaluated a family in whom a mildly affected mother and her two severely affected sons have manifestations of the Brachmann-de Lange syndrome suggesting that some cases of this disorder are inherited in an autosomal dominant fashion. Documentation of the clinical phenotype in two generations of this family permits further delineation of the phenotypic spectrum of the disorder. The fact that most affected patients represent sporadic cases in otherwise normal families might represent the inability of severely affected individuals to reproduce.

Adult↗