Seasonal changes of serum 25-hydroxyvitamin D and intact parathyroid hormone levels in a normal Japanese population.

We conducted an observational study in order to assess the prevalence of hypovitaminosis D and its seasonal changes, in the Tokai area (N35.3 E137.0), in 197 normal subjects in Japan. The mean serum 25-hydroxyvitamin D (25-OHD) level measured by direct radioimmunoassay (RIA) was lowest at the end of winter, and highest at the end of summer (15.1+/-7.1 ng/ml in March; 21.5+/-5.5 ng/ml in June; 31.6+/-5.6 ng/ml in September; 23.1+/-5.3 ng/ml in December; mean+/-SD). The prevalence of hypovitaminosis D (<20 ng/ml) was 86.7%, 33.4%, 1.0%, and 26.0% in March, June, September, and December, respectively. Mean plasma intact parathyroid hormone (iPTH) concentration was lowest at the end of summer and highest at the end of winter (28.2+/-9.3 pg/ml in March; 21.7+/-7.0 pg/ml in June; 19.8+/-6.9 pg/ml in September; and 25.7+/-9.2 pg/ml in December; mean+/-SD). Serum 25-OHD was inversely associated with iPTH (coefficient, -0.223; r=0.251; P<0.001). Serum 25-OHD levels were higher in men than in women. The serum 25-OHD level was positively associated with age, body weight, and body mass index, but not with body fat content. These results suggest a high prevalence of hypovitaminosis D associated with elevation of iPTH in Japan, in winter, even in a sunny area.

Pulmonary artery obstruction caused by thoracic aortic dissection: a case with unique pathological findings.

Pulmonary artery obstruction is a rare complication of acute thoracic aortic dissection. A 74-year-old woman was admitted to hospital with respiratory distress. Computed tomography scan showed right pulmonary artery occlusion and a thoracic aortic dissection of the Stanford A type. Lung perfusion scan revealed a defect in the entire right lung field. These findings mimicked acute pulmonary thromboembolism accompanying aortic dissection. On the other hand, pulmonary angiography revealed a round smooth defect of the right pulmonary artery, indicating an extrinsic compression. The patient finally died of cardiac tamponade. Autopsy disclosed that the right pulmonary artery was compressed by a hematoma in the adventitial space around the pulmonary artery. Such a mechanism of pulmonary artery obstruction caused by acute aortic dissection is unique, and is distinct from that caused by chronic non-dissecting aortic aneurysms, which themselves compress the pulmonary arteries. This complication inevitably follows aortic rupture; therefore, emergency operation to repair the dissected aorta must be performed to avoid the following catastrophic event.

Transient lymphocytic panhypophysitis associated with SIADH leading to diabetes insipidus after glucocorticoid replacement.

A 52-year-old man presented with vomiting, general fatigue and hyponatremia. His symptoms and signs were consistent with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Endocrine studies revealed hypopituitarism and administration of hydrocortisone resulted in a marked polyuria. The patient was diagnosed as masked diabetes insipidus. The lymphocytic hypophysitis was also diagnosed on the basis of MRI findings and anti-pituitary antibody. Six months later, these abnormalities disappeared. Diabetes insipidus may exist in a case of hyponatremia due to contrastive SIADH. Such patients may recover spontaneously and careful follow-up is required, avoiding a long-term treatment by monotonous continuation of hormonal replacement.

[Primary cardiac lymphoma: a case report].

A 83-year-old woman was admitted because of pretibial edema. Echocardiography demonstrated a huge tumor in the right atrium and ventricle. Transvenous biopsy failed to obtain sufficient specimens for the histological diagnosis. The tumor progressed rapidly and heart failure was intractable. The diagnosis was primary cardiac lymphoma on the basis of elevated soluble interleukin-2 receptor and solitary accumulation of gallium-67 in the heart. Chemotherapy was immediately started. After two courses of chemotherapy, the intracardiac tumor disappeared. However, one month later, the tumor relapsed in the anterior mediastinum. Needle biopsy disclosed diffuse B-cell non-Hodgkin's malignant lymphoma. Additional irradiation reduced the tumor. Early diagnosis and immediate chemotherapy are important for the treatment of primary cardiac lymphoma.