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Biomedical subjects

T Huang

Publications and source records attributed to T Huang.

At least 199 records · Page 11Linked to original sources

Testosterone secreting adrenal cortical adenomas.

We report the hormonal and radiological evaluation of two cases of adrenal cortical adenomas that secreted testosterone exclusively. We discuss some of the pitfalls in the diagnosis of this lesion, and summarize the current knowledge of the characteristic hormonal features in the two cases and the 12 cases previously reported.

17-Ketosteroids↗

Steroid hormone secretion from a virilizing lipoid cell tumor of the ovary.

The authors report the case of a 23-year-old woman with a virilizing lipoid cell tumor of the ovary. The patient developed precocious puberty at age 4 and from age 5 to 10 years was treated weekly with intramuscular medroxyprogesterone acetate. She began to menstruate spontaneously at age 13, but developed hirsutism, acne, and irregular menses at age 15 followed by secondary amenorrhea at age 20. Steroid analyses demonstrated elevated peripheral plasma levels of testosterone, dihydrotestosterone, androstenedione, 17 alpha-hydroxyprogesterone, progesterone, desoxycorticosterone, estrone, and estradiol. Catheterization of the adrenal and ovarian veins revealed increased secretion of testosterone, dehydroepiandrosterone, androstenedione, 17 alpha-hydroxyprogesterone, progesterone, desoxycortcosterone, and corticosterone, 11-desoxycortisol, cortisol, estrone, and estradiol from the right ovarian vein. At surgery a right ovarian lipoid cell tumor was removed. Incubation studies with the tumor tissue confirmed the presence of gonadal and adrenocortical steroids. The tissue also contained high-affinity human chorionic gonadotropin-luteinizing hormone binding sites with normal binding affinity.

Adrenal Cortex Hormones↗

Solid-phase synthesis of polynucleotides. III. Synthesis of polynucleotides with defined sequences by the block coupling phosphotriester method.

Preparation of the three hexadecanucleotides, dGpTpApTpCpApCpGpApGpGpCpCpCpTpT, dCpGpApCpGpApGpCpGpTpGpApCpApCpC and cTpGpCpCpGpGpCpCpApCpGpApTpGpCpG, is described by a rapid and simple solid-phase method on polyacrylamide supports. The synthesis were performed by the extension of the method described in the previous paper using di and trinucleotides of defined sequences as an incoming 3'-phosphodiester unit. Although the coupling yields to form phosphotriester bonds are slightly lower than those for the homothymidylic acid series, pure polydeoxyribonucleotides of defined sequences can be synthesized without any major difficulty.

Base Sequence↗

Solid-phase synthesis of polynucleotides. IV. Usage of polystyrene resins for the synthesis of polydeoxyribonucleotides by the phosphostriester method.

Contrary to the expectation, the Merrifield polystyrene resin, 2% cross-linked by divinylbenzene, is as efficient as the polyacrylmorpholide resin for the synthesis of polydeoxyribonucleotides using a phosphotriester method. On the Merrifield resin, the tetradecamer, dTpCpGpTpCpApApCpTpGpGpCpTpT, and the hexadecamer, dCpCpApGpTpCpApCpGpApCpGpTpTpGpT, were synthesized by the phosphotriester method using di and trinucleotide blocks as coupling units.

Base Sequence↗

Natural history of papillary lesions of the urinary bladder in schistosomiasis.

Variable epithelial hyperplasia was observed in urinary bladder of nine capuchin monkeys (Cebus apella) when examined at cystotomy 94 to 164 weeks after infection with Schistosoma haematobium. These hosts were followed for 24 to 136 weeks postcystotomy to determine the status of bladder lesions in relation to duration of infection and to ascertain whether lesion samples removed at cystotomy reestablished themselves in autologous and heterologous transfers. There was involution of urothelial hyperplasia in eight of nine animals and no evidence for establishment of transplanted bladder lesions.

Animals↗

Experimental biharzial bladder cancer: tryptophan metabolism in nonhuman primates experimentally infected with Schistosoma haematobium.

A nonhuman primate species infected with Schistosoma haematobium provided a model system for controlled studies on biharzial bladder cancer. Urinary excretion of tryptophan metabolites by capuchin monkeys (Cebus apella) was similar to that of humans when expressed per g creatinine. Liver tryptophan oxygenase activity of the capuchin monkeys was comparable to that of humans. Excretion of 3-hydroxykynurenine and 3-hydroxyanthranilic acid was elevated above control levels in capuchin monkeys infected experimentally with S. haematobium. The capuchin-S. haematobium system closely resembles the human biharziasis system and offers a reproducible laboratory model system for the controlled study of the parasitology, pathogenesis, and biochemistry of biharzial bladder cancer.

3-Hydroxyanthranilic Acid↗

MRX8: an X-linked mental retardation condition with linkage to Xq21.

A family in which 6 males have X-linked mental retardation has been studied with polymorphic DNA probes. The males differ from unaffected males only in impaired intellect and in smaller head size. The gene that causes mental retardation in the family appears to be located in band Xq21 on the basis of linkage with 3 markers: DXS250, DXS345 and DXS3 (theta max = 0.00; Zmax = 1.6). A multipoint lod score of 2.36 was obtain with no recombination relative to DXS326 in Xq21. This family is considered to have nonspecific X-linked mental retardation and has been given the designation MRX8.

Adult↗

Spastic paraplegia with iron deposits in the basal ganglia: a new X-linked mental retardation syndrome.

We report on a family with X-linked mental retardation (XLMR) and severe spastic paraplegia. Appearance is normal but there is severe involvement of the lower limbs (affected relatives never walked), with minimal involvement of the upper limbs and unusual MRI findings including macrogyria, white matter hypoplasia, lack of myelination and a markedly increased paramagnetic signal suggestive of iron deposition. Linkage studies documented possible linkage, with no recombination, between the disease locus and DXS424. A 7-point linkage analysis yielded a maximum LOD score of 1.9, (theta = 0.00) for three loci spanning Xq22-q25. The combination of the unusual clinical and MRI findings and the tentative localization to a region different than other XLMR syndromes with spastic paraplegia, provide good evidence that this is a new XLMR syndrome.

Adult↗

Colony-stimulating factor in middle ear cholesteatoma.

Granulocyte-macrophage colony stimulating factor (GM-CSF) was found in human middle ear cholesteatoma tissues by immunohistochemical technique using mouse monoclonal anti-(human) GM-CSF IgG. Immunofluorescent staining showed the presence of GM-CSF in the peribasal area, in some suprabasal cells of the epithelium, and in the inflammatory connective tissue, especially in the monocytes and fibroblasts. These findings were confirmed by the immunoperoxidase method. Staining of the external ear canal epithelium, however, was significantly weaker than that of the cholesteatoma epithelium. The presence of GM-CSF in cholesteatoma appears to be a response to inflammation occurring in the middle ear cavity. Moreover, our in vitro study showed that GM-CSF induced the proliferation and protein synthesis of basal keratinocytes. This study suggests that GM-CSF is involved in the development and destructive effects of middle ear cholesteatoma.

Cell Differentiation↗

Oxidative stress-induced apoptosis of cochlear sensory cells: otoprotective strategies.

Apoptosis is an important process, both for normal development of the inner ear and for removal of oxidative-stress damaged sensory cells from the cochlea. Oxidative-stressors of auditory sensory cells include: loss of trophic factor support, ischemia-reperfusion, and ototoxins. Loss of trophic factor support and cisplatin ototoxicity, both initiate the intracellular production of reactive oxygen species and free radicals. The interaction of reactive oxygen species and free radicals with membrane phospholipids of auditory sensory cells creates aldehydic lipid peroxidation products. One of these aldehydes, 4-hydroxynonenal, functions as a mediator of apoptosis for both auditory neurons and hair cells. We present several approaches for the prevention of auditory sensory loss from reactive oxygen species-induced apoptosis: 1) preventing the formation of reactive oxygen species; (2) neutralizing the toxic products of membrane lipid peroxidation; and 3) blocking the damaged sensory cells' apoptotic pathway.

Animals↗

A new syndrome: heart defects, laryngeal anomalies, preaxial polydactyly, and colonic aganglionosis in sibs.

We present two siblings, one male and one female, who have heart defects, duplication of toes, airway anomalies, and aganglionosis. The brother also has a bilateral complete cleft lip and palate. His airway anomalies include short epiglottis and aryepiglottic folds, which are different from his sister who has a bifid epiglottis with a central epiglottic mass. Both siblings have had some developmental delay. This constellation of anomalies appears to be unique and may represent a new autosomal recessive disorder.

Child, Preschool↗