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Biomedical subjects

J S Han

Publications and source records attributed to J S Han.

386 records · Page 22Linked to original sources
PubMedDate not supplied

Transtubular potassium concentration gradient (TTKG) and urine ammonium in differential diagnosis of hypokalemia.

BACKGROUND: Hypokalemia is a common and sometimes serious clinical problem, whose etiological diagnosis can frequently be based on the patient's history and the clinical setting. Measurement of urinary indices such as excretory rate of K+, random urine K+ concentrations and blood acid-base parameters have been employed in the pathophysiological diagnosis, though with some pitfalls. METHODS: To investigate the diagnostic usefulness of the transtubular potassium concentration gradient (TTKG) and urine ammonium in the differentiation of hypokalemia, we measured serum K+ and osmolality, random urine electrolytes, osmolality and ammonium, the urinary [Na]/[K] ratio (U(Na)/K), plasma aldosterone and TTKG in 7 patients with diarrhea, 6 with vomiting, 7 with mineralocorticoid excess, 6 with diuretic usage, and compared them with those of 7 overnight fasted and acid-loaded healthy volunteers. RESULTS: The urine K+ concentrations did not reflect urinary loss of potassium according to the subjects' hydration status. U(Na)/k in the hypokalemic patients with mineralocorticoid excess (1.4 +/- 0.5) was lower than in normal subjects (2.3 +/- 0.4) (p<0.05). TTKG was higher in hypokalemic patients with mineralocorticoid excess (13.3 +/- 4.4) and diuretic usage (8.6 +/- 1.3) and lower in those with diarrhea (1.6 +/- 0.3) than in the normal controls (5.0 +/- 0.7) (p<0.5). TTKG in the patients with vomiting (3.5 +/- 0.6) was the same as in normal controls. TTKG was stronger correlated with the plasma aldosterone levels in the hypokalemic patients due to renal potassium loss. Urine ammonium concentrations of the acid-loaded normal subjects (73.3 +/- 5.0 mEq/L), patients with diarrhea (74.4 +/- 2.0 mEq/L) and patients with mineralocorticoid excess (68.7 +/- 6.9 mEq/L) were higher than in overnight-fasted normal subjects (31.3 +/- 4.9 mEq/L). CONCLUSION: TTKG and random urine ammonium were useful in the pathophysiological differential diagnosis of hypokalemia.

Diagnosis, Differential↗
PubMedDate not supplied

Bilateral emphysematous pyelonephritis with perirenal abscess cured by conservative therapy.

Emphysematous pyelonephritis is a rare life-threatening infection of the renal parenchyma. It usually affects unilateral kidney and occurs mostly in diabetic patients. It is characterized by the presence of gas within the renal parenchyma and requires prompt diagnosis and early aggressive therapy. Bilateral emphysematous pyelonephritis is even more rare and is associated with high mortality. We describe a case of a 62-year-old diabetic woman who presented with nonketotic hyperosmolar coma and bilateral emphysematous pyelonephritis caused by Klebsiella pneumoniae. Diagnosis of bilateral emphysematous pyelonephritis was confirmed by an abdominal computed tomographic scan and microbiologic studies. Our patient was successfully treated using percutaneous catheter drainage and long-term antibiotic therapy.

Abdominal Abscess↗
PubMedDate not supplied

Coagulopathy in hemorrhagic fever with renal syndrome (Korean hemorrhagic fever).

The pathophysiology of bleeding manifestations in hemorrhagic fever with renal syndrome (HFRS) was elucidated by serially evaluating coagulation and fibrinolytic profiles and complement alterations in patients with HFRS. In the early stage of the disease, platelet counts, platelet survival time, and platelet aggregation in vitro decreased. Prolongation of bleeding time, prothrombin time, and activated partial thromboplastin time was noted, with decreases in coagulation factors II, V, VIII, IX, and X. Levels of fibrinogen were decreased, and those of fibrinogen-fibrin degradation products in serum and urine were increased. Concentrations of plasminogen, alpha 2-plasmin inhibitor, and antithrombin III in plasma were depressed. Procoagulant activity was present in plasma. Circulating immune complexes were found, whereas serum levels of C3 were decreased. In the early stage of HFRS, thrombocytopenia, defects in platelet function, and disseminated intravascular coagulation may play central roles in the pathogenesis of bleeding manifestations. Vasculopathy and immunologic aberrations also may play a role.

Antigen-Antibody Complex↗
PubMedDate not supplied

Demonstration of diastematomyelia and associated abnormalities with MR imaging.

Three patients were studied with a 0.3 T superconducting magnet to assess the role of magnetic resonance (MR) imaging in the recognition and evaluation of diastematomyelia and associated abnormalities. Comparison was made with other imaging techniques, including metrizamide computed tomographic (CT) myelography. With MR imaging, the divided spinal cord was well imaged in its entire craniocaudal extent, comparable to CT myelography. The bony septum, when it contained a marrow cavity, was also seen well. In two patients, dural ectasia and low position of the spinal cord with and without associated lipoma were clearly imaged. MR imaging demonstrated associated syringohydromyelia in one patient that was not detected by other radiologic studies. This preliminary experience with MR imaging of diastematomyelia suggests that once the bony details of the abnormality are defined, MR imaging can delineate the presence and extent of the divided spinal cord as well as its associated abnormalities adequately, obviating other studies.

Adolescent↗
PubMedDate not supplied

Computed tomography of carotid-cavernous fistula.

Fourteen patients with angiographically-proven carotid-cavernous fistulas were evaluated by computed tomography (CT). Unilateral or bilateral exophthalmos was noted in 12 patients. Slight blurring of the margin of the globe was present in two, presumably due to pulsations of the globe or conjunctival edema. Superior ophthalmic veins were prominent in 12 patients and were often larger on the side of the fistula. Irregularity or absence of contrast enhancement of the superior ophthalmic vein may indicate partial or complete thrombosis. Focal bulging or diffuse distention of the cavernous sinus was noted in nine patients. Enlargement of the extraocular muscles was observed in seven with swelling of the eyelids and edema of the conjunctiva in eight patients. The pattern of venous drainage, type of fistula, and time intervals between trauma, commencement of fistula, and CT scan may affect the CT manifestations of carotid-cavernous fistulas.

Adult↗
PubMedDate not supplied

Mycobacterium tuberculosis infection in a corticosteroid-treated rheumatic disease patient population.

OBJECTIVE: To investigate the incidence and risk factors of Mycobacterium tuberculosis infection in longterm corticosteroid treated rheumatic disease patients. METHODS: We assessed retrospectively the incidence of active tuberculosis and its risk factors in 269 rheumatic disease patients treated with moderate to high doses of corticosteroid for an evaluation period representing 1,035 corticosteroid years of therapy. RESULTS: The mean daily dose of steroid was 18.7 mg prednisolone and the mean daily dose during the first year of treatment was 20.4 mg prednisolone. 21 of these patients developed active tuberculosis resulting in an incidence rate of 20/1,000 patient-years. Cumulative and mean daily steroid doses during the follow-up period and during the first year of treatment, and a history of steroid pulse therapy were significantly correlated with the development of tuberculosis. A past history of tuberculosis, initial chest P-A abnormality, the starting dose of steroid, a history of more than 30 mg/day of prednisolone for more than one month, and a history of cytotoxic therapy were not related to the development of tuberculosis. CONCLUSION: The incidence of active tuberculosis is increased in rheumatic patients on moderate-to-high dose steroid treatment. Its risk factors are the cumulative and mean daily steroid doses during the follow-up period and during the first year of steroid treatment, and a history of steroid pulse therapy.

Adolescent↗