A healthy, full-term infant is born via uncomplicated vaginal delivery. As part of a research study, blood is drawn 30 minutes after birth. Which of the following laboratory findings is expected at this time point?
A 10-year-old patient admitted after a traumatic brain injury develops polyuria. Laboratory results show a low serum sodium of 125 mEq/L, high urine output, and a high urine sodium concentration of 160 mEq/L. On examination, the patient is clinically hypovolemic with orthostatic hypotension. Which condition best explains this clinical and laboratory picture?
An 11-year-old obese female is newly diagnosed with type 2 diabetes mellitus with an HbA1c of 7.8% and mild polyuria. In addition to comprehensive lifestyle modification counseling, what is the most appropriate first-line pharmacologic therapy to initiate?
A 6-year-old boy presents to your clinic with severe short stature. His parents are of average height. During the physical exam, you note the presence of a solitary median maxillary central incisor. This finding raises your suspicion for an underlying hypothalamic-pituitary disorder. The presence of this specific midline facial anomaly indicates a higher likelihood of which pituitary hormone deficiency?
An 8-year-old boy with a history of a central nervous system tumor was treated one year ago with cranial radiation at a dose of 55 Gy. Which pituitary hormone is most vulnerable and leads to a deficiency?
A 14-year-old boy is referred for delayed puberty and short stature. He has no secondary sexual characteristics, his height is at the 3rd percentile, and his bone age is 12 years. His father also experienced a late growth spurt and is now of normal height. The pediatrician considers a short course of testosterone therapy to address significant psychosocial concerns. What is the primary goal of this intervention?
A 14-day-old male infant is recalled for an abnormal newborn screen showing a significantly elevated 17-hydroxyprogesterone level. The infant has been feeding poorly for the last two days and has had one episode of emesis. On evaluation, he is found to be hyponatremic and hyperkalemic. Which of the following is the most likely diagnosis?
A 16-year-old asymptomatic female is diagnosed with diabetes during a school screening. Her fasting glucose is consistently around 130 mg/dL and her HbA1c is 6.8%. Her mother and maternal grandmother were also diagnosed with mild diabetes as young adults. Autoantibody testing is negative. Which diagnosis is most likely in this patient?
A 4-year-old boy is evaluated for accelerated growth, development of pubic hair, and acne over the last six months. His bone age is 7 years. Laboratory studies show markedly elevated serum dehydroepiandrosterone sulfate (DHEAS) and testosterone, but a normal 17-hydroxyprogesterone level. A low-dose dexamethasone suppression test fails to suppress his cortisol. An abdominal ultrasound is most likely to reveal which of the following?
An 11-year-old female with Graves disease, started on methimazole three weeks ago, presents to the emergency department with a fever of 102°F (38.9°C) and a severe sore throat. What is the most crucial initial step in her management?