Biomedical subjects
J B Stanbury
Publications and source records attributed to J B Stanbury.
Influence of nutritional state on the disposal of orally and intramuscularly administered iodized oil to iodine repleted older children and adult women.
Iodinated oil (Ethiodol, 1 or 2 ml) was administered po or by im administration to adult women and older children in rural highland Ecuador who were either well nourished or malnourished to determine the effect of nutritional status on the disposal rate of iodine. These subjects resides in a region previously severely deficient in iodine, but this had been corrected in these subjects by prior administration of iodinated oil or by use of iodized salt or both. Malnutrition as determined by the conventional standards of height for age was associated with a significantly shortened retention time of the administered iodine, whether given po or im. The half life of retention was approximately half in the malourished of that in the well nourished. If these findings can be extrapolated to chronically iodine deficient subjects, then malnourished populations in need of iodine supplementation should either receive higher dosages than those conventionally employed or more frequent dosage.
Effects on school children of prophylaxis of mothers with iodized oil in an area of iodine deficiency.
The results of tests of intellectual and psychomotor performance and school performance in a group of school children from a rural impoverished and iodine deficient Andean community whose mothers received injections of iodinated oil prior to the end of the first trimester of pregnancy have been compared with results in children from a neighboring comparable community whose mothers had received no iodinated oil. Subjects between ages 8 and 15 were studied. Statistically significant differences were not observed between the two groups in tests of intellectual function, but children of mothers who had received iodinated oil performed better on tests of psychomotor maturation. The group whose mothers had received oil performed distinctly better when assessed in terms of school drop-out rates, grades achieved, grades repeated, and in overall performance as judged by teacher notes in school records. Performance of both groups on standard tests of intellectual and psychomotor function was lower than standard scores. This may be a result of social and cultural deprivation, the general malnutrition prevailing in the region or other unidentified factors. The improved scoring and school performance exhibited by the children of mothers who received iodinated oil underlines the importance of prophylaxis with iodine in iodine deficient regions as one important contributor to community development.
Biochemical changes in periodontal ligament ground substance associated with short-term intrusive loadings in adult monkeys (Macaca Fascicularis).
Proteoglycan-like fractions (PG) were isolated from the ligaments of teeth undergoing various degrees of intrusive loadings. The PG were characterized by their molecular-size profiles on Sepharose 4B, the presence of uronic acid in the separated fractions and by the electrophoretic detection of constituent glycosaminoglycans including heparan sulphate, hyaluronic acid, dermatan sulphate and chondroitin-4-sulphate. The high molecular-weight fraction, peak i (estimated minimum size, 2 X 10(6) daltons) of the normal-functioning (stressed) ligament was reduced approx. 70 per cent, compared with ligament undisturbed for 3 h. There was a decrease in peak-i size between 0.25 and 1 N loadings of approx. 72 per cent. The 4 N loadings produced a further decrease followed by an increase during a 3 h undisturbed recovery phase. Thus changes in the chemistry and properties of the ground-substance components of the periodontal ligament could partly explain changes in tooth mobility.
Studies on the organic polyanionic constituents of human acquired dental pellicle.
Extracts of acquired dental pellicle were obtained by a two-step procedure. Pellicle formed on cleaned teeth was first extracted using 2 M CaCl2, and the remainder then removed by scraping followed by solubilization in 5 per cent (w/v) EDTA. The 2 M CaCl2 extract contained high-molecular-weight glycoprotein which was present in only trace amounts in the EDTA extract. Cellulose-acetate electrophoresis of both extracts revealed low-molecular weight protein which contained phosphate. This protein tentatively identified as a phosphoprotein, disappeared as the pellicle matured. The findings have implications in relation to early bacterial colonization of the tooth surface.
A case report on international cooperation in the study of thyroid disease.
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Glycosaminoglycans in human gingival crevicular fluid as indicators of active periodontal disease.
The glycosaminoglycans (GAG) in gingival crevicular fluid (GCF) were investigated by cellulose-acetate electrophoresis of samples from individual sites of defined conditions variously affecting the tissues of the periodontium. The non-sulphated GAG, hyaluronic acid, was present in all samples and was the only major band from sites of chronic gingivitis. An additional sulphated GAG band identified by enzymic digestions as chondroitin-4-sulphate, was detected in GCF from sites of untreated-advanced periodontitis. Initial samples from sites of early periodontitis and juvenile periodontitis yielded a similar additional band which was not detected, however, in samples collected after either surgery to eliminate deep pockets or daily subgingival irrigation with a chlorhexidine solution. Sulphated GAG was also present in fluid from the control situations, i.e. of teeth either undergoing orthodontic movement or showing evidence of trauma from occlusion, and from healing tooth-extraction wounds. Thus the presence of such a component in GCF correlates with those clinical conditions in which degradative changes are occurring in the deeper-periodontal tissues. The electrophoretic profile of GAG in a sample of GCF may be a sensitive laboratory method of indicating active phases of destructive periodontal disease at individual sites.
Neurological signs in congenital iodine-deficiency disorder (endemic cretinism).
Neurological examinations were made of 67 children and adults with congenital iodine-deficiency disorder (endemic cretinism) in four rural villages in highland Ecuador. There was a distinct and readily identifiable pattern of neurological deficits. These included, to varying degrees: deaf-mutism or lesser degrees of bilateral hearing-loss or dysarthria; spasticity, particularly involving the proximal lower extremities; mental deficiency of a characteristic type; and rigidity and bradykinesia. Not all of these elements were found in all cases. Less common features were strabismus, kyphoscoliosis and frontal-lobe signs. There were exceptional cases with hypotonia. In contrast, cerebellar function was largely spared, as were functions of emotion and attention, vegetative and autonomic functions, social interaction, and probably memory, except in the most severely involved.
Interaction of acid glycosaminoglycans (mucopolysaccharides) with hydroxyapatite.
Selected acidic glycosaminoglycans (GAG) have been used as a model series to study some binding properties of hydroxyapatite. The order of binding was heparin, heparin sulfate, dermatan sulfage/chondroitin-4-sulfate/chondroitin-6-sulfate (all similar) and hyaluronic acid, indicating that the negative charge on the molecules is a major determinant in the binding process. Both calcium and saliva pretreatment led to an increase in uptake of selected GAG whereas fluoride even at 1 and 3 parts/106 levels led to a graded reduction in uptake. The clinical significance of these findings may be related to the presence of certain GAG in the dental integuments and to the interaction of a chemically defined group of compounds at a specific solid surface. Such findings may also have an application in studies on endogenous mineralization. The results are in accord with the generally held view that polyanions may interact electrostatically with calcium sites present in the crystal lattice of the hydroxyapatite.
The metabolism of proteoglycans and glycosaminoglycans in inflamed human gingiva.
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Interactions of protein deficiency, cyanide, and thiocyanate on thyroid function in neonatal and adult rats.
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Effect of maternal hypothyroidism and triiodothyronine on the fetus and newborn in rats.
Of 36 adult female rats studied 19 were radiothyroidectomized; 3 weeks later all rats were bred. Radiothyroidectomized rats were divided into Groups I-III. Group I was untreated. Maternal weight gain was not noted until day 9 and was steady thereafter. Group III rats were treated with triiodothyronine up to the first day of pregnancy, but were hypothyroid during gestation (elevated TSH and low T3). Group II rats were treated with T3 up to the day of delivery. The pregnancy, its outcome, and TSH and T3 levels were similar to the normal controls (Group VI). Pregnancy, its outcome, and TSH and T3 levels were not different from controls when T3 was given to normal rats up to day 1 of pregnancy (Group IV). T3 concentrations were elevated in the normal rats which were given T3 continuously up to the day of delivery (Group V). However, the animals did not appear to be thyrotoxic and TSH was not suppressed. The size of the litters of Group I mothers was significantly less than in other groups and this difference may be attributed to an increased tendency to resorb implanted fetuses in untreated hypothyroid mothers. However, activity, day of eye opening weight gain, and TSH and T3 levels of the pups of all the groups were similar up to age 21 days. The data indicate the independence of the fetal pituitary-thyroid axis from maternal thyroidal status in rats.
Metabolic aspects of a protein-sparing modified fast in the dietary management of Prader-Willi obesity.
Four adolescents or young adults with the Prader-Willi syndrome (hypotonia, mental retardation, hypogonadism and obesity) received a protein-sparing modified fast consisting of 1.5 g of meat protein per kilogram of ideal body weight and meeting vitamin, mineral and fluid requirements. Evaluation of nitrogen and energy metabolism revealed the development of starvation ketosis and a positive nitrogen balance. Serial whole-body potassium measurements in two patients confirmed preservation of lean tissue despite continuing loss of weight. Clinical diabetes mellitus in two subjects was rapidly ameliorated by the regimen. Short-term weight loss greater than 18 kg occurred in three of the four subjects, and reduced weight persisted during observation periods of 26 to 44 months. This degree of outpatient diet adherence by mentally deficient subjects, who do not normally experience satiety, suggests that hunger is eliminated or at least reduced by modified, protein-sparing fasting.
Partial and total iodide organification defect in different sibships in a kindred.
Identical twins with goiter but without intellectual retardation and with slightly delayed bone age were found to have defective iodide organification as demonstrated by incomplete perchlorate discharge tests. They are grandnieces of a normal member of a sibship which included four children with severe retardation and complete thyroid iodide organification defect. The parents and grandparents are not consanguine. Possible explanations are considered for the problem of why the disorder is manifest completely in one sibship and only partially in the other.
An improved electrophoretic procedure for the detection of acidic glycosaminoglycans (mucopolysaccharides).
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Studies on a cell line from a functional rat thyroid tumor in continuous culture.
A clonal cell line derived from a functional and transplantable rat thyroid tumor was established in continuous monolayer culture by the use of enzymatic dissociation followed by an alternate culture-animal passage procedure. After being implanted backin the animal and again plated in culture, epithelial-like cells aggregated and rearranged themselves over the bottoms of dishes in structures resembling cross sections of a normal thyroid gland. The same morphology and growth pattern were maintained after innumerable subcultures and freeze/thawing periods. Cells grew with a population-doubling time of about 24 h in serum-supplemented synthetic medium. Cell monolayers stained with periodic acid-Schiff (PAS) showed a uniformly epithelial-like morphology; their cytoplasm contained abundant PAS-positive material that was resistant to enzymatic digestion with amylase. Thin-layer chromatography of acid-butanol cell extracts in primary and clonal cultures, followed by a specific and sensitive staining method for iodine compounds, demonstrated the presence of monoiodotyrosine (MIT), diiodotyrosine, and triiodothyronine-thyroxine. In contrast, in similar extracts obtained from a cultured liver cell line, the only iodinated amino acid was MIT. Thus, with regard to the above criteria, this cell line preserved specialized thyroid cell morphology and function.
The metabolism of perchlorate in the rat.
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Factors which may alter the epidemiology of endemic goiter.
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