Patient description: The patient is a 16-year-old girl recently diagnosed with myasthenia gravis, class IIa. She complains of diplopia and weakness affecting in her upper extremities. She had a positive anti-AChR antibody test, and her single fiber electromyography (SFEMG) was positive. She is on acetylcholinesterase inhibitor treatment combined with immunosuppressants. But she still has some symptoms. She does not smoke or use illicit drugs. She is not sexually active, and her menses are regular. Her physical exam and lab studies are not remarkable for any other abnormalities. BP: 110/75 Hgb: 11 g/dl WBC: 8000 /mm3 Plt: 300000 /ml Creatinine: 0.5 mg/dl BUN: 10 mg/dl Beta hcg: negative for pregnancy

Clinical trial eligibility criteria: eligible ages (years): 0.0-999.0,  Sjogren's Syndrome Female gender only, ages 18 to 75. Patients should have documented primary Sjogren's syndrome as determined by protocol 84-D-0056. The diagnosis of primary Sjogren's syndrome will be based on the presence of all three of the following: Salivary gland abnormalities; Lacrimal gland abnormalities; Serologic abnormalities. Controls should have no signs or symptoms of Sjogren's syndrome, and negative serologic testing reconfirmed within 2 weeks of the OGTT. Willingness to: a) participate in phase I and II of the protocol; b) follow the guidelines set to prepare for the OGTT; and c) modify current medical therapy if necessary. Must be able to comply with protocol procedures. No patients with "incomplete" Sjogren's syndrome, i.e., with less than three positive findings as described above. No presence of physical or mental conditions that may interfere with the protocol. These the following diseases and conditions: (Present at time of phase I/II): significant disruption of sleep-wake pattern (i.e., less than 4 hours of continuous sleep, on the night before the OGTT only), BMI less than 18 or equal to/greater than 30, anemia with Hgb less than 10 gm/dl, use of tobacco or alcohol; (Within the past 6 weeks): acute weight change (greater than 5%), use of contraceptives -BCP-, Depoprovera or Norplant), irregular menstrual cycle, lactation, blood drawing in excess of 50 ml, use of recreational drugs, modification of estrogen replacement therapy; (Within the past 6 months): chronic pattern of weight change (greater than 10%), eating disorders, uncontrolled hypo/hyperthyroidism, breast cancer, lymphoma or other malignancy, pregnancy, treatment for depression, insulinoma, VIPoma, pheochromocytoma, atrophic gastritis, active tuberculosis or treatment for it; (A history of): HIV+, sarcoidosis, secondary Sjogren's syndrome, bleeding diathesis, organ transplant, severe neuroendocrine, renal, cardiovascular, pulmonary or gastrointestinal disease (e.g., renal insufficiency, unstable angina, heart failure, severe emphysema, Crohn's disease), diabetes mellitus, acromegaly and mental retardation. No contraindications to OGTT. These Hospital inpatient status, acute illness, immobilization, starvation, severe emotional distress within one week of the OGTT; Low carbohydrate diet (less than 150 g/day) for 3 days preceding the OGTT; Pregnancy; Therapy which impairs glucose tolerance: e.g., niacin, thiazide diuretics, phenytoin, excess thyroxine or psychotropic drugs within 1 month of phase I, oral contraceptives within 6 weeks of phase I, glucocorticoid treatment within the past 6 months (or one year if treatment lasted over 2 weeks), Beta blockers/agonists (e.g., terbutaline) within 2 days of phase I; Diabetes mellitus; Glucose intolerance. Subjects may not take medications that can affect somatostatin levels, such as antidepressants, benzodiazepines, neuromodulators (e.g., cholinergic, alpha/beta adrenergic), oral contraceptives (BCP), steroid hormones (with the exception of estrogen replacement therapy -ERT-, for which subjects will be matched), immunomodulators, anticonvulsants (e.g., carbamazepine), cimetidine -Tagamet® (Registered Trademark)-, herbal remedies (because of their variable substance content). Subjects may not take drugs affecting gastrin secretion: antacids (e.g., Maalox® (Registered Trademark), Mylanta® (Registered Trademark), H(2) receptor antagonists (e.g., famotidine -Pepcid® (Registered Trademark)-, ranitidine -Zantac® (Registered Trademark)-), cathecolamines, atropine, haloperidol. To become eligible, subjects should be able to safely discontinue these medications at least one month prior to phase I. Antacids, H(2) antagonists and neuromodulators (e.g., Salagen) may be discontinued 2 days prior to phase I. Patients cannot have take experimental drugs within 1 month of the beginning of the protocol