Search PubMed⌕ Search

Biomedical subjects

C A Gorman

Publications and source records attributed to C A Gorman.

At least 55 records · Page 3Linked to original sources
PubMed1991

Stimulation of glycosaminoglycan accumulation by interferon gamma in cultured human retroocular fibroblasts.

Fully expressed Graves' disease involves an accumulation of glycosaminoglycan (GAG) in the retroocular connective tissue which contributes to the pathogenesis of ophthalmopathy. We treated cultured retroocular and dermal fibroblasts with recombinant interferon gamma (100 U/ml) for 16-24h and measured [3H]GAG accumulation. The cytokine stimulated [3H]GAG accumulation in retroocular fibroblast cultures obtained from eight different donors by 36-124% above control values. In contrast, interferon gamma had no consistent effect on macromolecular accumulation in dermal fibroblast cultures derived from the pretibium or from areas ordinarily uninvolved in Graves' dermopathy. These results suggest that retroocular fibroblasts may be uniquely targeted for one action of interferon gamma which involves the modulation of GAG metabolism.

Cells, Cultured↗
PubMed1991

Increased induction of HLA-DR by interferon-gamma in cultured fibroblasts derived from patients with Graves' ophthalmopathy and pretibial dermopathy.

We investigated the effects of several cytokines on HLA-DR expression in cultured fibroblasts derived from retroocular connective tissue and pretibial and abdominal skin of patients with Graves' ophthalmopathy (GO) and pretibial dermopathy (PTD), as well as from normal individuals. We hypothesized that differences in response to cytokines between fibroblasts from various anatomical areas might play a role in the site-selective involvement of the extrathyroidal manifestations of Graves' disease. HLA-DR expression in fibroblasts was quantitated by scanning densitometry of whole cell lysates subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. Direct immunofluorescence of cell monolayers was also performed. We hypothesize that unique characteristics of these fibroblasts may play a role in GO and PTD. Cultured retroocular, pretibial, and abdominal fibroblasts from patients with Graves' disease as well as from normal individuals did not express HLA-DR spontaneously. Treatment in vitro with interferon-gamma (IFN gamma; 100 U/mL) for 5 days induced HLA-DR by 50- to 80-fold (P less than 0.0001) in fibroblasts from all sites and subjects studied. However, IFN gamma-induced HLA-DR expression was significantly greater in retroocular (P less than 0.005) and pretibial (P less than 0.0005) fibroblasts from patients with GO and PTD than in fibroblasts obtained from the same anatomical sites of normal individuals. Further, retroocular and pretibial fibroblasts from patients with GO and PTD responded to IFN gamma more vigorously than did abdominal fibroblasts from these same patients (P less than 0.0001). IFN gamma-induced HLA-DR expression was enhanced by concomitant treatment with tumor necrosis factor-alpha (100 U/mL). In contrast, treatment of retroocular fibroblasts with transforming growth factor-beta (10 ng/mL), epidermal growth factor (1 ng/mL), or interleukin-6 (IL-6; 100 U/mL) significantly attenuated IFN gamma-induced HLA-DR reactivity by 40-59% (P less than 0.05). Incubation of retroocular fibroblasts with tumor necrosis factor-alpha, IL-1 alpha (10 U/mL), IL-2 (10 U/mL), IL-6, granulocyte-macrophage colony-stimulating factor (100 U/mL), epidermal growth factor, and transforming growth factor-beta alone did not affect HLA-DR expression. These results indicate that several cytokines can influence HLA-DR expression in cultured fibroblasts. The enhanced induction of HLA-DR by IFN gamma in retroocular and pretibial fibroblasts compared with that in abdominal fibroblasts may partially explain the selective involvement of the retroocular connective tissue and pretibial skin in fully expressed Graves disease.

Cell Line↗
PubMed1991

Detection, cellular localization, and modulation of heat shock proteins in cultured fibroblasts from patients with extrathyroidal manifestations of Graves' disease.

We hypothesize that fibroblasts obtained from the retroocular space and the pretibial skin, sites affected by the peripheral manifestations of Graves' disease, share unique characteristics that may in part explain the site specificity of Graves' ophthalmopathy (GO) and pretibial myxedema (PTM). Heat shock proteins (HSPs), synthesized by cells undergoing stress, function to maintain cellular homeostasis and are probably involved in the intracellular processing and cell surface presentation of antigens. We investigated possible differences in the expression of 70-kDa HSPs between cultured fibroblasts obtained from patients with severe GO and normal individuals. In addition, we compared HSP expression in fibroblasts derived from tissues involved in the extrathyroidal manifestation of Graves' disease (GO and PTM) with that in fibroblasts from uninvolved tissues. HSPs were detected by both immunoblotting and indirect immunofluorescence, using monoclonal antibodies that are directed against HSP72, HSP72/73 (termed HSP70), and HSP90. HSP expression at baseline and after treatment with various cytokines and heat stress was examined. At baseline, HSP72 reactivity was exclusively detected in retroocular and pretibial fibroblasts from patients with severe GO and PTM, but was not observed in abdominal fibroblasts from these patients and was not detectable in fibroblasts from any anatomical site of normal individuals. The abundance of HSP70 expression at baseline and after treatment with certain cytokines was significantly greater in retroocular and pretibial fibroblasts from patients with GO than in normal individuals. In addition, characteristic changes in the cellular localization of HSPs before and after exposure to heat stress and cytokines were observed; cell surface expression of HSP70 was detected at baseline in fibroblasts from patients, but not in normal fibroblasts. These data provide the first evidence that HSPs are differentially expressed by fibroblasts derived from tissues affected by the extrathyroidal manifestations of GD. These proteins may have a role in localized immune processes, leading to the development of GO and PTM.

Biopsy↗
PubMed1990

Clinical review 13: Diagnosis and management of Graves' ophthalmopathy.

Although Graves ophthalmopathy is a potentially sight threatening and disfiguring condition that can be frightening for the patient to experience, there are effective means of management. At the present time, treatment is based on the relief of excessive intraorbital pressures and is accomplished either by shrinking the orbital contents or by expanding the orbital volume. The most effective treatment modality or combination of modalities is an area of controversy. However, it must be remembered that the approach to management undertaken should be finely tuned to the needs of the particular individual afflicted with the condition. Perhaps with a greater understanding of pathophysiology, more reliable and effective treatments, based on specific pathophysiological mechanisms, may be developed. In addition, tests to reliably predict those patients most likely to progress in their disease might be developed, allowing preventive measures to be taken.

Female↗
PubMed1990

Iodine-131 treatment of Graves' disease using modified early iodine-131 uptake measurements in therapy dose calculations.

We hypothesized that early uptake of iodine-131 (131I) at 3-6 hr (EU) by the thyroid could be used to calculate 131I therapy with results comparable to those obtained using late uptake of 131I at 20-28 hr (LU) results. A retrospective study was undertaken. Twenty-seven patients with untreated thyrotoxic Graves' disease were given 3-5 microCi of 131I and EU and LU were determined with an uptake probe. We derived a "best fit" curve on plots of EU (X-axis) and LU (Y-axis). The equation for the curve (LU = -55.7 + 73.2 log EU) was used to predict late uptake (PU) from EU results on a second group of 24 similarly defined Graves' patients. PU and measured LU were then applied to 131I treatment calculations in these 24 patients. PU correlated closely with LU (r = 0.94). Dose calculations based on PU and LU gave very similar results (r = 0.97). Using this method, same day diagnosis and treatment of Graves' is achievable.

Female↗
PubMed1989

Presence of antibodies in the sera of patients with Graves' disease recognizing a 23 kilodalton fibroblast protein.

We examined whether antibodies (present in sera from patients with Graves' disease) might be directed against a connective tissue cellular component of the anatomical regions affected in the peripheral manifestations of that disease. Accordingly, we performed immunoblot analyses of cultured retroocular and pretibial fibroblasts. Retroocular connective tissue was obtained during orbital decompression surgery (n = 7) and at autopsy from normal individuals (n = 2). Pretibial skin biopsies were obtained from patients with pretibial dermopathy (n = 3) and at autopsy (n = 2). In addition, biopsies from other regions [extraocular muscle (n = 6), thyroid (n = 2), and abdominal skin (n = 3)] were also collected at surgery or autopsy. Serum samples were obtained from patients with severe Graves' ophthalmopathy (n = 31), hyperthyroid Graves' disease without overt ophthalmopathy (n = 13), nodular thyroid disease (n = 7), Hashimoto's thyroiditis (n = 7), rheumatoid arthritis (n = 5), and systemic lupus erythematosus (n = 3) and from normal individuals (n = 33). Electrophoresed fibroblast proteins were immunoblotted with 1:100 dilutions of sera using an antihuman immunoglobulin G-alkaline phosphatase conjugate. Antibodies against a 23kDa fibroblast protein were present in the sera from 24 of 44 (56%) of patients with Graves' disease with or without ophthalmopathy, 0 of 7 nodular thyroid disease, 0 of 7 Hashimoto's thyroiditis, 0 of 5 rheumatoid arthritis, 0 of 3 systemic lupus erythematosus, and 5 of 33 (15%) normal subjects. Significant differences in the observed frequency of antibodies existed between the Graves' disease group and the normal control group (P less than 0.01) or those patients with the other conditions (P less than 0.01). This 23kDa antigen was apparent in fibroblasts derived from individuals with Graves' disease as well as normal individuals and was present in fibroblasts from all anatomical sites studied. It was the sole protein uniquely recognized by sera from patients with Graves' disease. However, this serum reactivity did not appear to be related to the presence of clinically overt ophthalmopathy or pretibial dermopathy. Subcellular localization studies disclosed that the antigen was present in the supernatant but not the pellet resulting from a 100,000 x g centrifugation of whole cell sonicates. Antibodies against a 23kDa fibroblast protein are present in the majority of sera from patients with Graves' disease and rarely in sera from either normal individuals or those with other thyroid disorders or autoimmune diseases. Our results suggest the possibility that antibodies directed against this fibroblast antigen may be related to the developm

Antibodies↗
PubMed1989

Hormonal regulation of hyaluronate synthesis in cultured human fibroblasts: evidence for differences between retroocular and dermal fibroblasts.

Fibroblasts derived from retroocular connective tissue and skin were propagated in culture in an effort to identify structural and functional differences in connective tissue which might explain the apparent region-specific involvement in Graves' disease. Striking morphological differences existed between cultured cells from the two anatomical sites. Inhibition of glycosaminoglycan (GAG) accumulation by T3 and dexamethasone in these cultures was compared. Confluent cultures were labeled with [3H]acetate, and total [3H]GAG was quantitated. Fibroblasts from the skin responded to T3 (100 nmol/L) and dexamethasone (100 nmol/L) with 27% and 55% inhibition of [3H]GAG accumulation, respectively (n = 12). In contrast, retroocular fibroblasts responded with 12% and 8% inhibition (n = 6) to the two hormones. When cultures from abdominal skin and retroocular tissue were treated with n-butyrate (10 mM), a compound known to inhibit hyaluronate specifically, they responded similarly with 78% and 83% inhibition, respectively. A pulse-chase study was performed using fibroblasts from both sites, and no [3H]GAG degradation could be detected for the duration of the chase period (up to 72 h). These results suggest that retroocular fibroblasts, likely participants in the pathogenesis of Graves' ophthalmopathy, do not respond vigorously to T3 or glucocorticoids in terms of inhibition of [3H]GAG synthesis as do their dermal counterparts.

Cells, Cultured↗
PubMed1988

Triiodothyronine: a substrate for the thermostable and thermolabile forms of human phenol sulfotransferase.

The enzyme(s) responsible for the sulfate conjugation of L-T3 in man has not been characterized. T3 sulfotransferase (T3-ST) activity was characterized in normal human liver tissue obtained during clinically indicated surgical resection. Subcellular distribution studies showed that the T3-ST activity was localized to the cytoplasmic fraction. This finding raised the possibility that T3-ST activity might be similar to the 2 previously identified forms of cytoplasmic phenol sulfotransferase (PST) found in human tissue. A thermostable (TS) form of PST catalyzes the sulfate conjugation of micromolar concentrations of p-nitrophenol, and a thermolabile (TL) form catalyzes the sulfate conjugation of dopamine and other monoamines. Thermal stability and enzyme inhibitor experiments showed that T3-ST activity in pooled liver homogenates was very similar to the TS form of PST. The apparent similarity of T3-ST to TS PST was studied further by measuring T3-ST, TS PST, and TL PST activities in 20 individual liver samples. T3-ST activities correlated significantly with TS PST activities (r = 0.939; P less than 0.001) measured with p-nitrophenol, but not with TL PST activities (r = -0.118; P greater than 0.6) measured with dopamine. However, sulfation of T3 by the TL form of the enzyme might have been masked by the 18-fold higher specific activity of TS than TL PST in human liver homogenates. When the two forms of PST were separated by ion exchange chromatography, T3 was found to be a substrate for both the TS and TL forms of PST. "True" Km values for T3 were similar for TS and TL PST (81 and 127 microM, respectively).

Adult↗
PubMed1988

Distant metastases in differentiated thyroid carcinoma: a multivariate analysis of prognostic variables.

From a cohort of 988 patients with differentiated thyroid carcinoma receiving primary surgical treatment between 1946 and 1970, we studied the 85 (9%) patients who had distant metastases diagnosed during life. Clinically detected metastases were found in 7% of the 859 patients with papillary cancers, 19% of the 100 patients with follicular cancers, and 34% of the 29 patients with Hürthle cell cancers. The total experience amounted to 607 patient-years of observation after the diagnosis of metastases, with a median follow-up in the 12 survivors of 23 yr (range, 13-32 yr). At the time of first diagnosis of metastases, the lungs only were involved in 53%, and bones only in 20%; 16% had multiple organ involvement. The overall mortality rates 5 and 10 yr after the diagnosis of metastases were 65% and 75%, respectively. Seventy-eight percent of all deaths were directly attributable to thyroid cancer; 82% of cancer deaths occurred within 5 yr. By univariate analysis, patient age, tumor extent, pattern of lung involvement, radioiodine uptake of the metastases, and radioiodine treatment were significant prognostic factors. By multivariate analysis, only age (as a continuous variable) at the time of first diagnosis of distant metastases (P less than 0.0001) and involvement of multiple organ sites (P = 0.0003) were independently associated with cancer mortality. The survival at 5 yr in 12 patients aged less than 40 yr with only a single organ involved was 92%. Older patients (aged greater than or equal to 40 yr) with a single metastasis (n = 59) had a lower survival (38% at 5 yr). The highest risk of cancer death (92% at 5 yr) was found in the 14 patients (any age) who at the time of first diagnosis of metastases had multiple organ involvement. The Cox regression model suggested that radioiodine therapy did not have a significant influence on survival, after adjusting for age and extent of metastatic involvement.

Adolescent↗
PubMed1988

Diagnostic evaluation of Graves' ophthalmopathy.

The important questions to be answered in the course of decision-making in patients with Graves' ophthalmopathy include the following: 1. Is the eye problem owing to Graves' ophthalmopathy? If not, the cause of the eye problem must be sought. 2. Does the patient have serious medical problems apart from the thyroid and the eyes? Define type and severity, and risk to life and well-being. Do they preclude anesthesia or steroid therapy? 3. Is the patient euthyroid? Define thyroid abnormality and treat. 4. Is the eye problem the highest medical priority for the patient and the physician? If not, treat the highest priority, then return to the eyes. 5. Which particular manifestations of Graves' ophthalmopathy are the most troublesome to the patient? Establish priorities according to need and rational order for surgical procedures. 6. How have the eyes been treated in the past? What has been successful? What side effects have resulted? In the evaluation of a patient with possible Graves' ophthalmopathy, no single clinical or laboratory feature is necessary or pathognomonic of the disorder. The sufficient findings for a diagnosis are a matter of clinical judgment. Several diagnostic tools including CT scanning, various ophthalmologic examinations, and studies of thyroid function are available. The physician must use these tools, along with clinical judgment, to establish the diagnosis with maximum certainty. Following this, the particular manifestations of the disease that are most troublesome to the patient must be carefully defined and assessed. Only then can the treatment be optimally tailored to the patient's needs.

Graves Disease↗
PubMed1987

Suppressive therapy with levothyroxine for solitary thyroid nodules. A double-blind controlled clinical study.

Thyroid nodules are present in up to 50 percent of adults in the fifth decade of life. Patients are often treated with thyroxine in order to reduce the size of the nodule, but the efficacy of thyrotropin-suppressive therapy with thyroxine remains uncertain. In this study, 53 patients with a colloid solitary thyroid nodule confirmed by biopsy were randomly assigned in a double-blind manner to receive placebo (n = 25) or levothyroxine (n = 28) for six months. Before treatment, pertechnetate-99m thyroid scanning showed that 22 percent of the nodules were functional, 25 percent hypofunctional, and 53 percent nonfunctional. High-resolution (10-MHz) sonography was used to measure the size of the nodules before and after treatment. Suppression of thyrotropin release was confirmed in the levothyroxine-treated group by the administration of thyrotropin-releasing hormone; thyrotropin release was normal in the placebo group. Six months of therapy did not significantly decrease the diameter or volume of the nodules in the levothyroxine group as compared with the placebo group. We conclude that the efficacy of levothyroxine therapy in reducing the size of colloid thyroid nodules is not apparent within six months, despite effective suppression of thyrotropin.

Adult↗
PubMed1987

Human retroocular fibroblasts in vitro: a model for the study of Graves' ophthalmopathy.

Orbital connective tissue and extraocular muscles are histologically abnormal in patients with Graves' ophthalmopathy (GO). Although extraocular muscles have been extensively studied as a target for autoimmune attack in the disease, no system has been available to study retroocular fibroblasts in GO. We developed a technique to isolate fibroblasts from minced explants of connective tissue removed in the course of transantral orbital decompression surgery for GO. Postmortem specimens from individuals without evidence of thyroid disease were obtained from the same anatomical site. Confluent cells could be passaged at least 10 times with stable morphology and frozen with greater than 75% viability. An enzyme-linked immunosorbent assay was used to study the in vitro binding of serum immunoglobulin G (IgG) to these cells. We found no difference in the degree of specific binding between GO cells and cells from normal individuals. However, there was significantly greater binding of IgG from GO sera than of that from normal serum to retroocular GO fibroblasts. These results suggest that serum IgG autoantibodies against normal retroocular fibroblasts are present in some GO patients.

Adult↗
PubMed1987

Choice of therapy and criteria for assessing treatment outcome in thyroid-associated ophthalmopathy.

Treatment recommended for thyroid-associated ophthalmopathy varies with the particular expression of the disease in a given patient. Medical therapy may be beneficial in the early phase before extensive fibrosis of retro-ocular muscles and connective tissue is established. Although corticosteroids reliably suppress acute inflammatory changes, evidence supporting efficacy of plasmapheresis, immunosuppressive drugs, iodine-131 ablation, and radiotherapy is inconclusive. Surgery on eyelids, extraocular muscles, and orbit effectively rehabilitates most patients with even the most severe ophthalmopathy while having no effect on the underlying autoimmune process. Future research should include continued attempts to identify the putative target antigens in the orbit and to define the controls of glycosaminoglycan synthesis. Until prevention by immunologic or other medical means is attainable, surgery on orbit, muscles, and eyelids appears the most effective mode of treatment for correction of the functional and cosmetic consequences of the ophthalmopathy associated with autoimmune thyroid disease.

Eye Diseases↗
PubMed1985

Stereospecific determination and in vivo monodeiodination of thyroxine enantiomers in euthyroid man.

To compare in man the absorption, serum disappearance, and peripheral monodeiodination of the thyroxine enantiomers, we studied six euthyroid subjects who, on separate occasions, orally ingested 3 mg of either dextrothyroxine (DT4) or levothyroxine (LT4). We measured the serum concentrations of total T4 (TT4), total T3, and reverse T3 (rT3) by nonstereospecific radioimmunoassay and we determined serum DT4 and LT4 by stereospecific chromatography. Mean serum TT4 levels from 4 hours were significantly greater after LT4 administration. After DT4 administration, stereospecific analysis of serum revealed two T4 peaks that persisted from 2 to 48 hours. The mean serum LT4 level did not significantly change during the 48 hours after DT4 administration. Increases in serum T3 and rT3 were seen from 2 hours after administration of either enantiomer. From 12 hours the levels of both triiodothyronines after LT4 were significantly higher than after DT4. In this short term study we found no evidence that in man DT4 is converted to LT4, nor is it preferentially deiodinated to rT3. The greater and more persistent increases in serum T4 and T3 observed after LT4 probably contribute to the known higher bioactivity of that enantiomer.

Absorption↗
PubMed1985

Diagnosis and management of endocrine ophthalmopathy.

Most patients with Graves' hyperthyroidism have mild or inapparent ophthalmopathy. For the unusual patient with severe ophthalmopathy, a generally successful, coordinated, combined interdisciplinary medical and surgical management program is outlined.

Exophthalmos↗