Patient description: The patient is a 35-year-old woman with myasthenia gravis, class IIa. She complains of diplopia and fatigue and weakness that affects mainly her upper limbs. She had a positive anti-AChR antibody test, and her single fiber electromyography (SFEMG) was positive. She takes pyridostigmine 60 mg three times a day. But she still has some symptoms that interfere with her job. She is a research coordinator and has 3 children. Her 70-year-old father has hypertension. She does not smoke or use illicit drugs. She drinks alcohol occasionally at social events. Her physical exam and lab studies were 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): 21.0-65.0,  Type 2 Diabetes Mellitus Obesity Aim 2a. Subjects. Two groups (aged 21-65) will be studied: lean (BMI<25), healthy insulin sensitive subjects, and obese (BMI>30) nondiabetics 20 subjects will be enrolled 1. Subjects must be able to communicate meaningfully with the investigator and must be legally competent to provide written informed consent. 2. Subjects may be of either sex with age as described in each protocol. Female subjects must be non-lactating and will be eligible only if they have a negative pregnancy test throughout the study period. 3. Subjects must range in age as described in each specific protocol. 4. Subjects must have the following laboratory values: Hematocrit ≥ 35 vol% Serum creatinine ≤ 1.6 mg/dl AST (SGOT) < 2 times upper limit of normal ALT (SGPT) < 2 times upper limit of normal Alkaline phosphatase < 2 times upper limit of normal Triglycerides < 150 mg/dl. PT 11.7 -14.3 (During Liposyn/heparin infusion, PT will be determined to insure that it is < 1.5-2.0 times the normal value.) PTT 23.0-37.0. Aim 2b (muscle contraction and acetylation). Subjects. Two groups (aged 21-65) will be studied: lean (BMI<25), healthy insulin sensitive subjects, and obese (BMI>30) 32 subjects will be enrolled Subjects must be able to communicate meaningfully with the investigator and must be legally competent to provide written informed consent Subjects may be of either sex with age as described in each protocol. Female subjects must be non-lactating and will be eligible only if they have a negative pregnancy test throughout the study period Subjects must range in age as described in each specific protocol Subjects must have the following laboratory values: Hematocrit ≥ 35 vol% Serum creatinine ≤ 1.6 mg/dl AST (SGOT) < 2 times upper limit of normal ALT (SGPT) < 2 times upper limit of normal Alkaline phosphatase < 2 times upper limit of normal Triglycerides < 150 mg/dl. PT 11.7 -14.3 (During Liposyn/heparin infusion, PT will be determined to insure that it is < 1.5-2.0 times the normal value.) PTT 23.0-37.0. Aim 3 Subjects. Two groups (aged 21-65) will be studied: lean (BMI<25), healthy insulin sensitive subjects, and obese (BMI>30) 20 subjects will be enrolled Subjects must be able to communicate meaningfully with the investigator and must be legally competent to provide written informed consent Subjects may be of either sex with age as described in each protocol. Female subjects must be non-lactating and will be eligible only if they have a negative pregnancy test throughout the study period Subjects must range in age as described in each specific protocol Subjects must have the following laboratory values: Hematocrit ≥ 35 vol% Serum creatinine ≤ 1.6 mg/dl AST (SGOT) < 2 times upper limit of normal ALT (SGPT) < 2 times upper limit of normal Alkaline phosphatase < 2 times upper limit of normal Triglycerides < 150 mg/dl. INR < 1.3  Aim 2a Subjects must not be receiving any of the following medications: thiazide or furosemide diuretics, beta-blockers, or other chronic medications with known adverse effects on glucose tolerance levels unless the patient has been on a stable dose of such agents for the past three months before entry into the study. Subjects may be taking a stable dose of estrogens or other hormonal replacement therapy, if the subject has been on these agents for the prior three months. Subjects taking systemic glucocorticoids are excluded Subjects with a history of clinically significant heart disease (New York Heart Classification greater than grade II; more than non-specific ST-T wave changes on the EKG), peripheral vascular disease (history of claudication), or pulmonary disease (dyspnea on exertion of one flight or less; abnormal breath sounds on auscultation) will not be studied Recent systemic or pulmonary embolus, untreated high-risk proliferative retinopathy, recent retinal hemorrhage, uncontrolled hypertension, systolic BP>180, diastolic BP>105, autonomic neuropathy, resting heart rate >100, electrolyte abnormalities. Aim 2b Subjects must not be receiving any of the following medications: thiazide or furosemide diuretics, beta-blockers, or other chronic medications with known adverse effects on glucose tolerance levels unless the patient has been on a stable dose of such agents for the past three months before entry into the study. Subjects may be taking a stable dose of estrogens or other hormonal replacement therapy, if the subject has been on these agents for the prior three months. Subjects taking systemic glucocorticoids are excluded Subjects with a history of clinically significant heart disease (New York Heart Classification greater than grade II; more than non-specific ST-T wave changes on the EKG), peripheral vascular disease (history of claudication), or pulmonary disease (dyspnea on exertion of one flight or less; abnormal breath sounds on auscultation) will not be studied Recent systemic or pulmonary embolus, untreated high-risk proliferative retinopathy, recent retinal hemorrhage, uncontrolled hypertension, systolic BP>180, diastolic BP>105, autonomic neuropathy, resting heart rate >100, electrolyte abnormalities. Aim 3 Subjects must not be receiving any of the following medications: thiazide or furosemide diuretics, beta-blockers, or other chronic medications with known adverse effects on glucose tolerance levels unless the patient has been on a stable dose of such agents for the past three months before entry into the study. Subjects may be taking a stable dose of estrogens or other hormonal replacement therapy, if the subject has been on these agents for the prior three months. Subjects taking systemic glucocorticoids are excluded Subjects with a history of clinically significant heart disease (New York Heart Classification greater than grade II; more than non-specific ST-T wave changes on the EKG), peripheral vascular disease (history of claudication), or pulmonary disease (dyspnea on exertion of one flight or less; abnormal breath sounds on auscultation) will not be studied Recent systemic or pulmonary embolus, untreated high-risk proliferative retinopathy, recent retinal hemorrhage, uncontrolled hypertension, systolic BP>180, diastolic BP>105, autonomic neuropathy, resting heart rate >100, electrolyte abnormalities