Measurement of TSH receptor blocking immunoglobulins using 3H-adenine incorporation into FRTL-5 and JPO9 cells: use in a child with neonatal hypothyroidism

OBJECTIVE The aim of this study was to develop an assay for the measurement of thyroid blocking antibodies (TBAb), based on the ability of patient serum to inhibit TSH stimulated ³H-cAMP production following incubation of FRTL-5 or JPOS cells with ³H-adenine. The assay was then used to evaluate a child born with neonatal hypothyroidism. DESIGN The levels of TBAb, TSAb (thyroid stimulating antibodies), TBII (TSH binding Inhibitory antibodies), and the thyroid antibodies anti-thyroid peroxidase and thymoglobulin antibodies were measured in both mother and child over a 6-month post-natal period. PATIENT The assay for TBAb was used to evaluate a child born with neonatal hypothyroidism whose mother had a history of hypothyroidism due to Haehimoto's thyrolditis. A ^99mTc pertechnetate scan showed no evidence of functioning thyroid tissue. At 20 months of age an ultrasound verified a normally positioned thyroid. RESULTS Initially, high levels of TBII and antithyroid antibodies were present in the serum of both mother and child. In both, the levels of TSAb were undetectable but there were significant levels of TBAb. The levels of TBAb decreased to control levels in the child within 2 months of birth but remained elevated in the mother's serum. CONCLUSIONS This case of neonatal hypothyroidism associated with the passage of thyroid blocking antibodies demonstrates the utility of this new assay in the differential diagnosis of neonatal hypothyroidism.     

Clinical and prognostic significance of in vivo differentiation in acute myeloid leukemia

Bromodeoxyuridine (BrdU) was administered to 86 newly diagnosed patients with standard risk acute myeloid leukemia (AML) prior to starting induction therapy and the labeling index (LI), durations of S-phase (Ts), and the cell cycle (Tc) of myeloblasts were determined. Induction therapy with cytosine arabinoside and daunomycin was subsequently started. Bone marrow biopsies were obtained on days 6 and 17 and weekly thereafter, and were treated with a monoclonal anti-BrdU antibody to determine the fate of cells labeled on day 0 by BrdU. BrdU labeled granulocytes indicating the presence of in vivo differentiation (Diff+) were identified in 48 patients ranging from 1+ (1–10 labeled cells) to 4+ (greater than 31 labeled granulocytes). When compared to 38 differentiation negative (Diff-) patients, Diff+ group had longer Ts (14.5 hr vs. 10.95 hr, P = 0.015) and Tc (59.7 hr vs. 41.7 hr, P = 0.017). Remission duration was significantly longer (no median) for 3–4+ Diff+ as compared to Diff- (median = 220 days) patients (Wilcoxon P = 0.04). We conclude that the detection of in vivo differentiation in AML patients indicates a favorable long-term prognosis either due to the presence of a substantial amount of normal residual hematopoiesis prior to starting induction therapy or due to the ability of leukemic cells to undergo differentiation. © 1993 Wiley-Liss, Inc.     

Molecular characterization of a ring chromosome 16 from a patient with bilateral cataracts.

A four-month-old white female, who was referred to us for genetic evaluation because of severe developmental delay, dysmorphic features, and bilateral cataracts, was found by routine cytogenetic analysis to have ring chromosome 16 in almost all cells analyzed. Ring chromosome 16 was confirmed and further delineated by fluorescence in situ hybridization (FISH). Breakpoints between loci D16S521 and KG8 on the short arm and D16S3121 and D16S303 on the long arm of chromosome 16 were determined by polymerase chain reaction (PCR) analysis. The deleted chromosome was of maternal origin. To our knowledge, this is the first case of ring chromosome 16 associated with bilateral cataracts. Comparison of previously reported cases with deletion of chromosome 16 and our case suggests the presence of cataract locus within 1 Mb of the terminus of 16q.     

Pharmacokinetic Model of Ascorbic Acid in Healthy Male Volunteers During Depletion and Repletion

Purpose. To develop a new pharmacokinetic model for ascorbic acid (vitamin C) since no previously published model describes ascorbic acid absorption and disposition over a broad physiologic range of doses and plasma concentrations. Methods. A new model was developed through exploratory simulations. The model was fitted to pharmacokinetic data obtained from seven healthy volunteers who underwent ascorbic acid depletion then gradual repletion. Concentrations of ascorbic acid were measured in plasma and urine. Final pharmacokinetic model parameter estimates were obtained using nonlinear regression analysis. Results. The new model included saturable absorption, distribution and renal tubular reabsorption parameters. The model described ascorbic acid concentrations in plasma, cells, and urine during depletion and gradual repletion phases with a residual error less than 15%. Conclusions. The model was useful for obtaining a new understanding of the likely causes for the complex concentration-time profile observed during gradual repletion. At doses of 200 to 2500 mg per day, the plateau in pre-dose concentrations is largely due to apparent saturation of tissue uptake and less a function of oral bioavailability and renal excretion than previously thought.     

Molluscum contagiosum presenting as cellulitis in an AIDS patient: Cytologic and ultrastructural features

This report describes the cytologic features of molluscum contagiosum presenting clinically as a left thigh abscess in a 29-yr-old male with AIDS. the fine-needle aspiration findings are correlated with the histologic and ultrastructural findings. Molluscum contagiosum's clinical presentation, natural course, and induction of host immune responses in immunocompetent and immunosuppressed individuals as identified by light microscopy, immunocytochemically and ultrastructurally are reviewed. Molluscum contagiosum presenting clinically and cytologically as an abscess is unusual. in this report, we emphasize the inclusion of molluscum contagiosum in a differential diagnosis of an abscess, particularly in immunosuppressed patients, and discuss the cytologic differential diagnoses. © 1995 Willey- Liss, Inc.     

Sumatriptan contracts large coronary arteries of beagle dogs through 5-HT1-like receptors

Summary The effects of 5-hydroxytryptamine (5-HT), 5-carboxamidotryptamine (5-CT), methysergide and sumatriptan were studied on endothelium-denuded rings of beagle dog large coronary arteries. Submicromolar concentrations of the compounds contracted the rings with the order of potency 5-CT > 5-HT >sumatriptan = methysergide. Concentrations greater than 2 M of both 5-HT and 5-CT, and 60 mol/l methysergide also caused concentration-dependent relaxation. Sumatriptan did not cause relaxation. Peak intrinsic activities relative to the plateau contraction to sumatriptan (1.00), were 5-CT 0.47, 5-HT 0.87 and methysergide 0.51. Ketanserin 1 mol/l affected neither contractile responses nor relaxant responses to 5-CT, methysergide and sumatriptan and only caused marginal blockade of the contractile effects of 5-HT. Methiothepin 200 nM shifted the concentration-contractile response curves by around 2 log units, as expected from its affinity for 5-HT₁-like receptors.The rank order of contractile potency of the agonists, the antagonism by methiothepin and the resistance to blockade by ketanserin are consistent with a nearly exclusive involvement of 5-HT₁-like receptors. Isolated large coronary arteries from beagle dogs may be a suitable model for the study of human coronary artery 5-HT₁-like receptors that are involved in the spasm observed with 5-HT and sumatriptan. Correspondence to A. J. Kaumann at the above address