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Biomedical subjects

H B Burch

Publications and source records attributed to H B Burch.

76 records · Page 5Linked to original sources
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Immunogenicity of a unique region of the human thyrotropin receptor.

Clarifying the role of the TSH receptor protein in the autoimmune process may be the key to understanding the development of Graves' disease. In the present study we used a 16 amino acid peptide of the human TSH receptor (hTSHR) to immunize rabbits. A comparable, but theoretically less immunogenic, peptide was injected into other rabbits. The antibody response against these and other peptides, as well as against solubilized human thyroid membrane (TM) and guinea pig fat cell membrane (GPF) proteins, was tested using ELISA and Western blots. The GPF and TM binding pattern of rabbits' sera was compared to that of Graves' patients' sera. We have identified an area of antigenic cross-reactivity between GPF and TM; a 63 kD protein was present in both GPF and TM, and this protein uniformly bound IgG-s of the rabbits' postimmunization sera and one of eight Graves' patient's serum. We have shown that i) a theoretically immunogenic 16 amino acid peptide was indeed highly immunogenic in rabbits, ii) antibodies binding to GPF and TM were detected after immunization, and iii) the peak of thyroid stimulating immunoglobulin activity of sera was followed by a transient elevation of serum triiodothyronine levels. Further studies investigating the immunogenic epitopes of the hTSHR as well as characterizing the 63 kD protein are indicated.

Amino Acid Sequence↗
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Fine needle aspiration of thyroid nodules. Determinants of insufficiency rate and malignancy yield at thyroidectomy.

OBJECTIVE: To evaluate patient- and practice-specific determinants of the thyroid nodule fine needle aspiration (FNA) insufficiency rate and malignancy yield at a tertiary-care teaching hospital. STUDY DESIGN: All FNAs of thyroid nodules performed from August 1990 to October 1993 at the Walter Reed Army Medical Center Endocrinology Clinic were reviewed and the results analyzed for correlation with surgical outcome, scintiscanning result and operator experience. Provider-specific factors influencing the FNA insufficiency rate, surgical referral pattern and malignancy yield were evaluated. RESULTS: A total of 504 aspirations in 422 patients with thyroid nodules were included in the analysis. The sensitivity of FNA for detecting malignancy was 80%, specificity was 73.2%, and accuracy was 75.2%. A significant negative correlation was found between recent aspirator experience and the insufficiency rate. Repeat aspiration of nodules previously yielding benign cytology increased the malignancy yield. Surgical excision of nodules with insufficient aspirations gave a low malignancy yield, and aspiration of nodules that were "hot" on scintiscanning rarely yielded false positive FNA results. CONCLUSION: Specific limitations of thyroid nodule FNA include a large number of aspirates containing insufficient cytologic material and a variable malignancy yield. Specific recommendations based on the findings in this report are: the establishment of uniform criteria for judging specimen adequacy, the performance of repeat aspiration on thyroid nodules with previously benign aspirates, the abandonment of scintiscanning in the routine management of thyroid nodules and a conservative approach to clinically indolent nodules repeatedly found to have scant cellularity on FNA. Based on these findings, an algorithm for the diagnostic evaluation of a solid thyroid nodule can be constructed.

Adolescent↗
PubMedDate not supplied

Gluconeogenic enzymes in defined structures of developing rat nephron.

Three gluconeogenic enzymes, P-pyruvate carboxykinase (PPCK), fructose-1-6 bisphosphatase (FBPase), and glucose-6-phosphatase (G6Pase) were measured in identified structures of rat nephron from 2 days before birth to maturity. In the proximal convoluted tubule, the three enzymes increased from the earliest age assayed to +14 days (PPCK, 7-fold, FBPase, 2-fold and G6Pase, 50-fold). Among the 7 defined structures that were analyzed, highest levels at all ages were in the proximal convoluted tubule with almost no activity in the distal convoluted tubule. All three enzymes had negligible activity in the neogenic zone and mesenchyme. Supported by grants from the Public Health Service (HD 03891 and NS-05221) and the American Cancer Society (P-78).

Aging↗