Gary W. Cushing

MRI appearances of an ectopic pituitary adenoma: case report and review of the literature

MR images of an ectopic pituitary adenoma have been published in only a single case, a suprasellar mass. We present a patient with Cushings disease in whom MRI revealed a pituitary adenoma within the sphenoid sinus. Radiologic characteristics of ectopic pituitary adenomas are reviewed, with emphasis on MRI, which demonstrates a soft tissue mass, isointense with gray matter on T1-weighted images, which enhances in a heterogeneous manner.

The Effect of Methimazole on the Development of Spontaneous Lymphocytic Thyroiditis in the Diabetes-Prone BB/W Rat

Methimazole (MMI) administration decreases the incidence and intensity of experimentally induced lymphocytic thyroiditis (LT) in the female August rat and male A/J mouse. Spontaneous LT frequently occurs in the insulin-dependent type-I diabetic (DM) BB/W rat. Experiments were carried out to determine whether MMI administration to BB/W rats from 30 to 120 days, blood obtained for measurement of serum T4, TSH, and anti-Tg Ab (ELISA), and thyroids removed for histology. MMI administration was associated witha decrease in the incidence of LT (31% vs. 55%; p < 0.05) but no difference in the severity of the LT. Serum T4 was similar in the MMI and C groups, but seum TSH was slightly but significantly higher in MMI treated rats [43 ± 6 (mean ± SE) μU/ml vs. 30 ± 2.5; p < 0.05]. Serum anti-Tg Ab levels increased with age but MMI administration did not afect this rise. There was no significant difference in the incidence of insulin-dependent DM between the MMI and C rats (MMI, 56%; C, 74%). Conclusion: MMI administration to the genetically predisposed insulin-dependent diabetes and LT prone BB/W rat during the age when LT spontaneously occurs reduced the incidence of LT.

A Possible Role of Bacterial Antigens in the Pathogenesis of Autoimmune Thyroid Disease

This discussion concerns the possible relationship between bacterial antigens and the pathogenesis of autoimmune thyroid disease (AITD), with emphasis on the human pathogen Yersinia enterocolitica (Y.e.) and on Graves 1 disease. It is divided into three parts: a description of the fascinating background information that prompted us to investigate this topic; a brief description of our findings to date; and a consideration of their possible significance with respect to the pathogenesis of AITD.

Communication: Angle-resolved thermal dissociative sticking of CH4 on Pt(111): Further indication that rotation is a spectator to the gas-surface reaction dynamics

Effusive molecular beam measurements of angle-resolved thermal dissociative sticking coefficients for CH(4) impinging on a Pt(111) surface, at a temperature of 700 K, are reported and compared to theoretical predictions. The reactivity falls off steeply as the molecular angle of incidence increases away from the surface normal. Successful modeling of the thermal dissociative sticking behavior, consistent with existent CH(4) supersonic molecular beam experiments involving rotationally cold molecules, required that rotation be treated as a spectator degree of freedom.

Subclinical hypothyroidism. Understanding is the key to decision making.

Preview What causes subclinical hypothyroidism? How prevalent is it? When is it likely to progress to overt disease? Are clinical abnormalities sometimes present? Answers to these questions, as well as a discussion of treatment approaches, are found in this overview.

An effusive molecular beam technique for studies of polyatomic gas-surface reactivity and energy transfer.

An effusive molecular beam technique is described to measure alkane dissociative sticking coefficients, S(T(g), T(s); ϑ), on metal surfaces for which the impinging gas temperature, T(g), and surface temperature, T(s), can be independently varied, along with the angle of incidence, ϑ, of the impinging gas. Effusive beam experiments with T(g) = T(s) = T allow for determination of angle-resolved dissociative sticking coefficients, S(T; ϑ), which when averaged over the cos (ϑ)/π angular distribution appropriate to the impinging flux from a thermal ambient gas yield the thermal dissociative sticking coefficient, S(T). Nonequilibrium S(T(g), T(s); ϑ) measurements for which T(g) ≠ T(s) provide additional opportunities to characterize the transition state and gas-surface energy transfer at reactive energies. A resistively heated effusive molecular beam doser controls the T(g) of the impinging gas striking the surface. The flux of molecules striking the surface from the effusive beam is determined from knowledge of the dosing geometry, chamber pressure, and pumping speed. Separate experiments with a calibrated leak serve to fix the chamber pumping speed. Postdosing Auger electron spectroscopy is used to measure the carbon of the alkyl radical reaction product that is deposited on the surface as a result of alkane dissociative sticking. As implemented in a typical ultrahigh vacuum chamber for surface analysis, the technique has provided access to a dynamic range of roughly 6 orders of magnitude in the initial dissociative sticking coefficient for small alkanes on Pt(111).

Testicular Choriocarcinoma Presenting as Hyperthyroidism

A 46-year-old man with a remote history of benign skin cancer with no previous signs of hyperthyroidism presented to the clinic with abdominal pain that had lasted 1 week. Laboratory work showed hematocrit of 43% and hemoglobin of 14.7 g/dL, and computed tomography scan of the abdomen showed fat necrosis posterior to the stomach. The patient was recommended follow-up in 2 months. He then presented to the emergency department 1 month later with abdominal pain, melena, and shortness of breath lasting 1 month. In the emergency department, blood pressure was 110/66 mm Hg, and heart rate was 102 beats/min. Initial laboratory results showed hematocrit of 13.9% and hemoglobin of 4.5 g/dL. The international normalized ratio was 1.2. Computed tomography scan of the chest showed multiple lung masses, mediastinal and hilar adenopathy, and extensive hepatic metastases (Figure). Upper gastrointestinal endoscopy showed erosive esophagitis, and biopsy was nondiagnostic. Colonoscopy showed diverticulosis, and capsule endoscopy showed an ulcerated mass in the mid-distal small bowel. Computed tomographyeguided lung biopsy was performed. The patient’s symptoms improved with respect to gastrointestinal bleeding, and he was discharged with outpatient follow-up with pending pathology results. On discharge, blood pressure was 135/66 mm Hg and heart rate was 117 beats/min. Later biopsy results were nondiagnostic. The patient presented again 2 weeks later with similar abdominal pain, palpitations, weight loss, and heat intolerance. On examination, heart rate was 136 beats/min and regular. There were no signs of goiter or nodules. Testicular examination was normal. Computed tomography scan of the abdomen and pelvis revealed significant progression of metastatic disease involving the small bowel. Because of his symptoms, thyroid function tests were performed followed by betaehuman chorionic gonadotropin secondary to hyperthyroidism (thyroid-

Triglyceride High-Density Lipoprotein Ratios Predict Glycemia-Lowering in Response to Insulin Sensitizing Drugs in Type 2 Diabetes: A Post Hoc Analysis of the BARI 2D

Glycemic management is central in prevention of small vessel and cardiovascular complications in type 2 diabetes. With the plethora of newer medications and recommendations for a patient centered approach, more information is necessary to match the proper drug to each patient. We showed that BARI 2D, a five-year trial designed to compare two different glycemic treatment strategies, was suitable for assessing different responses according to different phenotypic characteristics. Treatment with insulin sensitizing medications such as thiazolidinediones and metformin was more effective in improving glycemic control, particularly in the more insulin resistant patient, when compared to the insulin provision strategy using insulin and or sulfonylureas. Triglyceride and high density lipoprotein ratio (TG/HDL-cholesterol ratio) was found to be a readily available and practical biomarker that helps to identify the insulin resistant patient. These results support the concept that not all medications for glycemic control work the same in all patients. Thus, tailored therapy can be done using phenotypic characteristics rather than a “one-size-fits-all approach.”

Hyperglycemia in the Surgical Intensive Care Unit

Hyperglycemia is the most common metabolic disturbance seen in the postoperative, intensive care patient. It can occur in patients with previously diagnosed diabetes mellitus, with undiagnosed diabetes,1 and in patients without diabetes under the acute stress of trauma, surgery, or myocardial infarction.2 Critical illness induces insulin resistance at the cellular level, which coupled with relative insulin inadequacy and unabated hepatic glucose release, leads to persistent elevation in blood glucose. A number of factors released during acute illness and stress act as mediators for this response, including cytokines, growth hormone, glucagon, catecholamines, and cortisol.3 Impairment of insulin action leads to lipolysis and protein catabolism that produce substrates for additional glucose production by the liver. Glycogenolysis is promoted by release or administration of catecholamines. Insulin-mediated glucose uptake by heart and skeletal muscle is impaired and further worsens glucose homeostasis. To some extent, the resultant increase in blood glucose can be adaptive to provide increased substrate to organs that do not require insulin for glucose uptake such as brain and blood cells. Not surprisingly, when pushed to the extreme by critical illness these accommodations can lead to untoward consequences requiring interventions in order to reverse this metabolic derangement.

Regulation of Growth of Thyroid Cells in Culture by TSH Receptor Antibodies and Other Humoral Factors

Highly differentiated target endocrine epithelia provide a valuable model for studies of cell replication, since their growth is regulated by their specific trophic hormone and since they may possibly respond as well to those growth factors that interact with a variety of cell types. Hence, studies of the independent and conjoint effects of trophic hormones and growth factors in target endocrine cells have the potential to elucidate both general mechanisms for the regulation of cell growth and abnormalities in endocrine cell growth that occur in disease.