Life-threatening dermatitis artefacta.
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Dermatitis↗
Biomedical subjects
J B Ross
Publications and source records attributed to J B Ross.
Steroid-binding site of human and rabbit sex steroid binding protein of plasma: fluorescence characterization with equilenin.
The interaction of the estrogen d-3-hydroxy-1,3,5(10),6,8-estrapentaen-17-one (equilenin) with the human and rabbit sex steroid binding proteins (hSBP and rSBP, respectively) has been investigated by using fluorescence and absorption spectroscopy. Equilenin competes for the binding of 5 alpha-dihydrotestosterone. The calculated binding constant of equilenin for rSBP is 1.9 X 10(7) M-1 at 4 degrees C, which can be compared with the binding constant of 5.7 X 10(7) M-1 reported for hSBP [Ross, J.B.A., Torres, R., & Petra, P.H. (1982) FEBS Lett. 149, 240]. The results of fluorescence quenching experiments with the collisional quenchers KI and acrylamide indicate that the bound steroid has limited accessibility to the bulk solvent and that there are no anionic surface groups near the steroid-binding site. The fluorescence excitation spectra of SBP-equilenin complexes are similar to the absorption spectra of equilenin in low-dielectric solvents. The fluorescence emission of the SBP-equilenin complexes, however, exhibits wavelength shifts (red shifts) opposite to those of the steroid in low-dielectric solvents or complexed with beta-cyclodextrin (blue shifts) but similar to the red shift produced by addition of the proton acceptor triethylamine to equilenin in cyclohexane. These data indicate that the steroid-binding site of hSBP and rSBP is a nonpolar cavity containing a proton acceptor that participates in a specific interaction, possibly a hydrogen bond, with the 3'-hydroxyl group of the bound steroid.
17-Ketosteroids↗
Time-resolved fluorescence and 1H NMR studies of tyrosine and tyrosine analogues: correlation of NMR-determined rotamer populations and fluorescence kinetics.
The time-resolved fluorescence properties of phenol and straight-chained phenol derivatives and tyrosine and simple tyrosine derivatives are reported for the pH range below neutrality. Phenol and straight-chained phenol derivatives exhibit single exponential fluorescence decay kinetics in this pH range unless they have a titratable carboxyl group. If a carboxyl group is present, the data follow a two-state, ground-state, Henderson-Hasselbalch relationship. Tyrosine and its derivatives with a free carboxyl group display complex fluorescence decay behavior as a function of pH. The complex kinetics cannot be fully explained by titration of a carboxyl group; other ground-state processes are evident, especially since tyrosine analogues with a blocked carboxyl group are also multiexponential. The fluorescence kinetics can be explained by a ground-state rotamer model. Comparison of the preexponential weighting factors (amplitudes) of the fluorescence decay constants with the 1H NMR determined phenol side-chain rotamer populations shows that tyrosine derivatives with a blocked or protonated carboxyl group have at least one rotamer exchanging more slowly than the radiative and nonradiative rates, and the fluorescence data are consistent with a slow-exchange model for all three rotamers, the shortest fluorescence decay constant is associated with a rotamer where the carbonyl group can contact the phenol ring, and in the tyrosine zwitterion, either rotamer interconversion is fast and an average lifetime is seen or rotamer interconversion is slow and the individual fluorescence decay constants are similar.
Hydrogen-Ion Concentration↗
Time-resolved fluorescence and 1H NMR studies of tyrosyl residues in oxytocin and small peptides: correlation of NMR-determined conformations of tyrosyl residues and fluorescence decay kinetics.
Steady-state and time-resolved fluorescence properties of the single tyrosyl residue in oxytocin and two oxytocin derivatives at pH 3 are presented. The decay kinetics of the tyrosyl residue are complex for each compound. By use of a linked-function analysis, the fluorescence kinetics can be explained by a ground-state rotamer model. The linked function assumes that the preexponential weighting factors (amplitudes) of the fluorescence decay constants have the same relative relationship as the 1H NMR determined phenol side-chain rotamer populations. According to this model, the static quenching of the oxytocin fluorescence can be attributed to an interaction between one specific rotamer population of the tyrosine ring and the internal disulfide bridge.
Kinetics↗
Molecular characterization of the sex steroid binding protein (SBP) of plasma. Re-examination of rabbit SBP and comparison with the human, macaque and baboon proteins.
Physico-chemical characterization of the sex steroid-binding protein, SBP, of rabbit plasma reveals that it is a dimer of mol. wt 85,800 composed of similar subunits of mol. wt 43,000. These data confirm our original proposal for a dimeric structure. The protein contains 9% carbohydrate, comprised of mannose, galactose, N-acetylglucosamine and sialic acid. It is devoid of N-acetylgalactosamine and fucose. The protein binds one molecule of 5 alpha-dihydrotestosterone per dimer with a Kd of 0.89 nM (12 degrees C). Comparison with the human, monkey and baboon SBPs indicates that all these proteins have the same dimeric molecular organization and exhibit microheterogeneity in SDS-PAGE and isoelectricfocusing. Rabbit SBP, however, contains less carbohydrate and has a higher polypeptide molecular weight than all the other SBPs. Spectrophotometric data also indicate that some tryptophan residues are in a different chemical environment than those in other SBPs. The observed microheterogeneity in all four SBP species is due for the most part to variable glycosylation of the subunit and variability at the amino-terminal region of the subunit. Combination of these and other phenomena will generate a significant number of isomeric forms of the SBP subunit which will then interact stoichiometrically to yield active dimeric SBP molecules. These differ slightly from each other depending upon the charge and size of the subunit comprising the dimeric structure, and will result in the observed microheterogeneity of pure SBP preparations. Based on these results along with more recent amino acid sequence data, we conclude that all four SBPs are dimers composed of identical polypeptide chains.
Amino Acid Sequence↗
Linked-function analysis of fluorescence decay kinetics: resolution of side-chain rotamer populations of a single aromatic amino acid in small polypeptides.
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Fluorescence↗
Estradiol entry into endometrial cells in suspension.
Cells from a human endometrial adenocarcinoma cell line (HEC-50) were superfused with mixtures of [3H]E2 and [14C]E1 in order to estimate rates of entry and exit of E1 and E2 into and out of cells according to previously published procedures (J. steroid Biochem., 13 (1980) 1379). Proportionality between rates of entry and concentrations of E2 outside the cells, indicative of passive diffusion, was found at levels of E2 ranging from 1 to 100 ng/ml. Effects of albumin and of pure human sex steroid binding protein (SBP) on the rate of entry of E2 were also evaluated in parallel superfusions. In other single tracer experiments, [3H]E2 was used at concentrations as low as 100 pg/ml and the effects of plasma proteins on entry were evaluated by measuring steady-state concentrations of E2 and E1 in cells and superfusate. Results from these experiments indicate that albumin, and to a larger extent SBP, reduced the entry of E2 into HEC-50 cells. Similar results were obtained when CG-5 cells, a variant of the human breast cancer cell line MCF-7, were superfused with [3H]E2. Further experiments are needed, however, to determine the physiologic role of plasma estrogen binding proteins on the entry and metabolism of E1 and E2 into target cells.
Adenocarcinoma↗
Multiple granulation tissue lesions occurring in isotretinoin treatment of acne vulgaris--successful response to topical corticosteroid therapy.
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Acne Vulgaris↗
Familial X-linked ichthyosis, steroid sulfatase deficiency, mental retardation, and nullisomy for Xp223-pter.
Steroid sulfatase (STS)-deficient X-linked ichthyosis was diagnosed in a man with short stature and mental retardation. His generation includes five similarly affected male members. A translocation chromosome is segregating in this Newfoundland kindred. The proband's mother and grandmother have normal skin and are of normal intelligence. From his carrier mother, the proband inherited an X short arm (Xp) to Y long arm (Yq) translocation chromosome, with the entire Y short arm and the X short arm terminal segment deleted (Xp223-pter). His cells are completely deficient in STS activity, confirming assignment of the STS locus to Xp223-pter. Effective management of his ichthyosis included treatment with 6% salicylic acid gel under plastic occlusion and removal of the scales by scrubbing.
Adult↗
Goodpasture's syndrome associated with skin involvement.
To our knowledge, skin lesions associated with Goodpasture's syndrome have not been reported to date. A patient developed discrete, macular, erythematous lesions on the instep of his foot, noted at the time of his admission to the hospital for treatment of Goodpasture's syndrome. Investigation showed perivasculitis and significant deposits of IgM and C3 at the dermoepidermal junction in the lesion site but not in the nearby skin. IgM deposits in the skin are unusual and the same immunoglobulin is found in the kidney in this syndrome. IgM deposit was absent from control samples of skin from four other patients with this syndrome. It is possible that these findings are significant.
Anti-Glomerular Basement Membrane Disease↗
Aplasia cutis congenita.
A newborn child was noted to have an ulcerated lesion on the vertex of her scalp, which was diagnosed as aplasia cutis congenita. As this disorder is relatively rare and frequently misdiagnosed, this case is reported and the relevant literature reviewed.
Female↗
Purification and characterization of the sex steroid binding protein from macaque serum. Comparison with the human protein.
The sex steroid binding protein (SBP) of Macaca mulatta and Macaca nemestrina sera has been purified to homogeneity and chemically characterized. The native protein is a glycoprotein having a molecular weight of approximately 88 000 and is composed of two similar subunits of molecular weight 47 000 as estimated by sodium dodecyl sulfate gel electrophoresis. One molecule of 5 alpha-dihydrotestosterone is bound per dimer with a KD equal to 1.6 nM at 11 degrees C. Isoelectric focusing patterns reveal the presence of at least 12 different forms of dimeric SBP molecules probably resulting from the presence of different amounts or types of carbohydrate side chains. The data indicate a very close similarity in molecular and steroid-binding properties to human SBP and establish the macaque monkey as a valuable animal model to study the physiological role of SBP in humans.
Amino Acids↗
Yellow nail syndrome and chronic sinusitis.
This paper reports the case of female patient who presented with the yellow nail syndrome and was ultimately found to have related chronic pansinusitis and bronchitis. The head and neck manifestations of this syndrome are described as well as the successful management of her sinusitis.
Adult↗
Treatment of coccidioidomycosis with ketoconazole: an evaluation utilizing a new scoring system.
The evaluation of the response of patients with coccidioidomycosis to any therapeutic modality is a major challenge. A numerical scoring system was devised to quantitate separately the severity of disease on clinical presentation, the findings on chest film, bone scan, gallium scan, serology and skin test with coccidioidin and spherulin. The scoring system was used to evaluate the response to treatment with ketoconazole of seven patients with infiltrate pulmonary coccidioidomycosis; 20 patients with chronic cavitary coccidioidomycosis; and 40 patients with disseminated coccidioidomycosis. Dissemination included the soft tissue in 15, bone in 15, synovium in 11 and skin in 18. In all categories clinical severity scores improved dramatically. Radiographic scores showed similar improvement in cases of infiltrative pulmonary coccidioidomycosis but showed no change in cavitary coccidioidomycosis. Serology scores improved significantly (-2 or more) in one of seven infiltrative pulmonary cases, three of twenty chronic cavitary cases and twenty-three of forty disseminated cases. Among those with adequate mycology followup, cultures converted to negative in two of three infiltrative pulmonary coccidioidomycosis; seven of fourteen chronic cavitary coccidioidomycosis; and sixteen of twenty-two with disseminated disease. Unfortunately, when ketoconazole was discontinued or interrupted, symptoms recurred in four of twenty (20 percent) with chronic cavitary and ten of forty (25 percent) of disseminated cases. The disease in two patients progressed while on ketonconazole. One of those developed meningitis.
Antifungal Agents↗
Current status of the molecular structure and function of the plasma sex steroid-binding protein (SBP).
Purification and characterization of the sex steroid-binding protein (SBP) from human, macaque, baboon, and rabbit sera indicate that the protein is composed of two polypeptide chains which associate noncovalently to yield a native structure having molecular weight distributions of about 88,000 for primate SBPs, and 80,000 for rabbit SBP. The subunit molecular weight distributions are 44,000 for human SBP, 47,000 for macaque and baboon SBP's, and 40,000 for rabbit SBP. Isoelectric focusing show extensive microheterogeneity for all four SBPs. The patterns appear to be unique for each species and reveal the presence of at least twelve bands of different colour intensity reflecting a specific spectrum of active SBP molecules. The existence of the large number of dimeric forms of SBP arises through the combination of many variants of the same two subunits containing different amounts and types of carbohydrate sidechains. Physiological studies on the intravenous infusion of pure rhesus SBP, human SBP, and purified monospecific SBP-antibodies into the rhesus reveal an inverse relationship between SBP and the metabolic clearance rate of testosterone. The effect is complex and depends on the concentration of SBP, albumin, and testosterone which in turn influences the distribution of testosterone between albumin and SBP.
Animals↗
Alopecia totalis as a presentation of cutaneous metastasis (alopecia neoplastica).
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Adenocarcinoma↗
Fetal lung maturity assessed by fluorescence polarization: evaluation of predictive value, correction for endogenous fluorescence, and comparison with L/S ratio.
The steady-state polarization (or anisotropy) of the fluorescent dye 1,6-diphenyl-1,3-5-hexatriene in amniotic fluid samples and the lecithin/sphingomyelin ratio of the samples were correlated with development of respiratory distress syndrome in newborns. We found that clinical samples have a variable endogenous fluorescence that reduces the observed polarization (or anisotropy). This background is a major interference in the assessment of fetal lung maturity by the polarization method. Correction for this interference, by also measuring the blank fluorescence and anisotropy of the sample, provides a clinical tool with a lower coefficient of variation than that of the more time-consuming lecithin/sphingomyelin ratio. The clinical correlation for 17 cases of respiratory distress syndrome in a high-risk population (60 births; twins counted as a single birth) indicates that the two methods are equivalent for predicting immature fetal lung status.
Amniotic Fluid↗