Calculation of maximal removal rate of indocyanine green to measure hepatic functional mass in dogs by use of the nine-hour method.

OBJECTIVE: To establish a versatile and reliable procedure for the determination of indocyanine green maximal removal rate (ICG Rmax) to measure hepatic functional mass in dogs within 9 hours (9-hour method). DESIGN: Relation between 9-hour and standard 3-day methods was examined. ANIMALS: 101 healthy dogs. PROCEDURE: On investigation of the optimal technical conditions allowing completion of all procedures in a day, the appropriate IV administered doses of ICG were 0.125, 0.5, and 2.0 mg/kg of body weight, and the best blood sample collection times for obtaining plasma half-life at these 3 doses were before and 3, 6, and 9 minutes after ICG administration. RESULTS: Comparison of the 9-hour with 3-day method yielded a correlation coefficient (r) of 0.84, indicating close (P < 0.01) correlation. In the 9-hour method, mean +/- SD of ICG Rmax in healthy dogs was 0.24 +/- 0.09 mg/kg/min in male (n = 62) and was 0.23 +/- 0.06 mg/kg/min in female (n = 21) Beagles, and was 0.21 +/- 0.10 mg/kg/min in male (n = 11) and 0.20 +/- 0.07 mg/kg/min in female (n = 7) mixed-breed dogs. In Beagles treated orally with carbon tetrachloride (0.1 ml/kg in gelatine capsules) thrice weekly during a 10-week period, plasma alanine transaminase activity plateaued at a high value (> 2,000 IU/L) on day 5, and remained at this value until the end of the study. The ICG Rmax changed accordingly: day 5, 0.17; day 10, 0.11; day 40, 0.05; and day 60, 0.06 mg/kg/min. CONCLUSION: The 9-hour method for determination of ICG Rmax correlates favorably with the 3-day method. CLINICAL RELEVANCE: This procedure may be practically applied in veterinary clinics in terms of prediction of hepatic functional mass, and for diagnosis of hepatotoxicosis induced by certain compounds.

Cytologic detection of malignant mesothelioma of the pericardium.

We have reported a very rare case, malignant mesothelioma of the pericardium, with the initial diagnosis made by cytology from the smears of the pericardial fluid. There were numerous large clusters in the smears, in which two types of cells were mixed: adenocarcinoma-like round cells and fibrosarcoma-like spindly cells. Some round cells very much resembled benign mesothelial cells. Central collagenous stalks and brush borders with long microvilli in the round cell aggregates were specific for carcinomatous mesothelioma and differentiated the round cells from adenocarcinoma cells. On the other hand, the spindly and pleomorphic tumor cells, present both singly and in clusters, implied malignancy. Therefore, a preliminary cytologic diagnosis of probable mixed malignant mesothelioma was made. Histopathologic and electron microscopic examinations confirmed the cytologic description that this tumor was a malignant mesothelioma.