Sarcoidosis: Evaluation and Treatment

Sarcoidosis is a multisystem granulomatous inflammatory disease of unknown etiology that can involve any organ. Ongoing dyspnea and dry cough in a young to middle-aged adult should increase the suspicion for sarcoidosis. Symptoms can present at any age and affect any organ system; however, pulmonary sarcoidosis is the most common. Extrapulmonary manifestations often involve cardiac, neurologic, ocular, and cutaneous systems. Patients with sarcoidosis can exhibit constitutional symptoms such as fever, unintentional weight loss, and fatigue. The early recognition and diagnosis of sarcoidosis are challenging because there is no diagnostic standard for testing, initial symptoms vary, and patients may be asymptomatic. Consensus guidelines recommend a holistic approach when diagnosing sarcoidosis that focuses on clinical presentation and radiographic findings, biopsy with evidence of noncaseating granulomas, involvement of more than one organ system, and elimination of other etiologies of granulomatous disease. Corticosteroids are the initial treatment for active disease, with refractory cases often requiring immunosuppressive or biologic therapies. Transplantation can be considered for advanced and end-stage disease depending on organ involvement.

Parathyroid Disorders

Parathyroid disorders are most often identified incidentally by abnormalities in serum calcium levels when screening for renal or bone disease or other conditions. Parathyroid hormone, which is released by the parathyroid glands primarily in response to low calcium levels, stimulates osteoclastic bone resorption and serum calcium elevation, reduces renal calcium clearance, and stimulates intestinal calcium absorption through synthesis of 1,25-dihydroxyvitamin D. Primary hyperparathyroidism, in which calcium levels are elevated without appropriate suppression of parathyroid hormone levels, is the most common cause of hypercalcemia and is often managed surgically. Indications for parathyroidectomy in primary hyperparathyroidism include presence of symptoms, age 50 years or younger, serum calcium level more than 1 mg per dL above the upper limit of normal, osteoporosis, creatinine clearance less than 60 mL per minute per 1.73 m2, nephrolithiasis, nephrocalcinosis, and hypercalciuria. Secondary hyperparathyroidism is caused by alterations in calcium, phosphate, and vitamin D regulation that result in elevated parathyroid hormone levels. It most commonly occurs with chronic kidney disease and vitamin D deficiency, and less commonly with gastrointestinal conditions that impair calcium absorption. Secondary hyperparathyroidism can be managed with calcium and vitamin D replacement and reduction of high phosphate levels. There is limited evidence for the use of calcimimetics and vitamin D analogues for persistently elevated parathyroid hormone levels. Hypoparathyroidism, which is most commonly caused by iatrogenic surgical destruction of the parathyroid glands, is less common and results in hypocalcemia. Multiple endocrine neoplasia types 1 and 2A are rare familial syndromes that can result in primary hyperparathyroidism and warrant genetic testing of family members, whereas parathyroid cancer is a rare finding in patients with hyperparathyroidism.

Physician use of an ambulatory medical record system: matching form and function

An ambulatory medical record system was implemented as a pilot project to determine the clinical and operational impacts of using interactive, computer-based systems in the outpatient setting. Of the 58 physicians who attempted to use the AMR system, 28 continue as active users. Physicians who discontinued use of the system reported a variety of reasons for their dissatisfaction. As a result of the pilot, the AMR implementation team and physicians understand better how to fit the AMR system to a physician's specific requirements, as well as enhance the operation of the physician's practice. Armed with the experience gained during the early phases of the implementation, the Cleveland Clinic Foundation now intends a cautious expansion and continued evaluation of the AMR system, with the objective of meeting organizational needs with appropriate technical functions.

Determinants of low birthweight: a comparative study

The study compares biological, socioeconomic and behavioural determinants of low birthweight in Cameroon and the United States. Some factors in low birthweight are found to be cross-national, but others are specific to the setting. Positive risk factors of low birthweight in both countries include unmarried motherhood, female sex, multiple births, and preterm births. Outcome of the previous pregnancy is a positive risk factor in the US, but not in Cameroon. Significant negative risk factors include prenatal care visits (in both countries), mother's education (in the US only), births to mothers aged 20-34 and birth orders of 2 or more (in Cameroon only). Separate analyses of all births and the subsamples of singleton births reveal that estimates for the two groups differ only marginally.

Characterization of human adipocyte adenosine receptors

125I-Hydroxyphenylisopropyl adenosine (125I-HPIA) was used to characterize adenosine receptors in human adipocyte plasma membranes. Steady state binding was achieved after 6 h at 37 degrees. Scatchard plots were linear, with a KD of approx. 2.5 nM, and Bmax of 360-1800 fmol/mg protein. (-)N6-phenylisopropyl adenosine (PIA) was a more potent inhibitor of binding than N-ethyl carboxamido adenosine, and (+)PIA was more than 10-fold less potent than (-)PIA, consistent with A1 adenosine receptor binding. Theophylline was a potent inhibitor of binding (IC50 approx. 10 microM). Photoaffinity cross-linking studies demonstrated that the receptor is a single subunit, Mr approx. 43 kDa. The findings demonstrate that the human adipocyte adenosine receptor is similar to the A1 adenosine receptor of rat adipocytes, although its molecular weight is higher, and its affinity for HPIA is lower than that of the rat.

Distribution of bombesin-like peptides in the alimentary canal of several vertebrate species

The objective of this study was to quantitate and characterize the variants of bombesin-like immunoreactivity in the alimentary canal of the rat, rabbit, hawk, owl, dog, monkey and human. Bombesin-like immunoreactivity was found throughout the entire gastrointestinal tract of all species studied. In the rat, the highest concentration of bombesin-like immunoreactivity was found in the colon. Gel chromatography showed that bombesin-like immunoreactivity corresponded to gastrin-releasing peptide (GRP-27) and GRP-10. In the dog, the greatest concentration of bombesin-like immunoreactivity was observed in the mucosal layer of the fundus, whereas the concentration of bombesin-like immunoreactivity in the muscle layer of the dog did not vary significantly from region to region. Gel chromatography showed that bombesin-like immunoreactivity in the dog corresponded to GRP-27, bombesin, GRP-10, and a smaller fragment. In the human, the concentration of bombesin-like immunoreactivity did not vary significantly from region to region in the mucosal and muscular layers. Gel chromatography of human fundal mucosa showed that bombesin-like immunoreactivity peaks occur in the regions of GRP-27, bombesin and GRP-10. These findings substantiate the observation that bombesin-like peptides play a variety of roles in the regulation of gut function.

Photochemical cross-linking of 125I-hydroxyphenylisopropyl adenosine to the A1 adenosine receptor of rat adipocytes

Rat adipocyte plasma membranes were incubated with the A1 adenosine receptor agonist, 125I-hydroxyphenylisopropyl adenosine (1 nM) and then treated with the photoactive cross-linking agent, ANB-NOS. The membranes were solubilized and analyzed by SDS-PAGE and autoradiography. A single protein, Mr approx. 38,000, was specifically labeled. Reduction with 2-mercaptoethanol did not affect the apparent Mr of the labeled protein. Labeling was inhibited by the adenosine receptor agonists, HPIA, PIA and NECA, and by the antagonist, theophylline, but was unaffected by inosine. We conclude that the A1 adenosine receptor is a single protein of Mr approx. 38,000.