Gamma camera scintigraphy of tumours using (195m)Pt-cisplatin.

Platinum enriched with 194Pt was irradiated for 4 days in NRG's TIRO 1 reactor, to produce (195m)Pt. Spectral analysis of the product was performed using a calibrated hyper pure germanium detector and its constituent radioisotopes were identified as (195m)Pt, 199Au and 192Ir. Using the detector's intrinsic efficiency calibration, their activities were estimated to be 1049, 133 and 5.8 MBq, respectively. The performance of the gamma camera was tested using quality control procedures recommended by the Institute of Physics and Engineering in Medicine (IPEM) and was found to be satisfactory. A torso phantom was used to determine the minimum detection limit (MDL) of (195m)Pt in a 2 cm diameter tumour using SPECT acquisitions (32 steps, 60 s per step). The MDL was found to be 8 ppm assuming an administered patient dose of 50 MBq and a total cisplatin dose of 105 mg. This work indicates that (195m)Pt-cisplatin is suitable for clinical scintigraphy and has led to the development of a clinical protocol that has been approved for a pilot study.

Biochemical effects of oral sodium phosphate.

Our objective was to monitor serum and urine biochemical changes after oral sodium phosphate cleansing in a prospectively designed study. The study subjects were seven healthy, asymptomatic adults. Sodium phosphate 45 ml diluted in 45 ml water was given orally at baseline and 12 hr later. Calcium, ionized calcium, phosphorus, sodium, potassium, creatinine, and PTH were analyzed at 2, 4, 6, 9, 12, 14, 16, 18, 21 and 24 hr after the first challenge. Urinary calcium, phosphorus, sodium, potassium, and cyclic AMP were analyzed at baseline and every 2 hr after oral sodium phosphate. Blood pressure, pulse, and respiratory rate were recorded every 2 hr and symptom questionnaires using visual analog scales were completed. A marked rise in phosphorus (peak range 3.6-12.4 mg/dl, P < 0.001) and falls in calcium (P < 0.001) and ionized calcium (P < 0.001) were seen. Rises seen in PTH and urinary cAMP confirmed the physiologic significance of the biochemical effect. There were no significant changes in other serum and urine laboratory or clinical assessments. Reported significant symptoms included bloating, cramps, abdominal pain, and nausea. Significant hypocalcemia and hyperphosphatemia after oral sodium phosphate raises concern about its use in normal individuals. Oral sodium phosphate should not be administered in patients with cardiopulmonary, renal, or hepatic disease.

Recognizing primary biliary cirrhosis and primary sclerosing cholangitis.

Nonsuppurative cholangiopathies such as primary biliary cirrhosis and primary sclerosing cholangitis are chronic cholestatic liver diseases that result from inflammation of the biliary system. Recent advances in management options for patients with primary biliary cirrhosis and primary sclerosing cholangitis have facilitated treatment by family physicians. Patients with significant laboratory abnormalities on liver tests for cholestasis should be evaluated for possible primary biliary cirrhosis or primary sclerosing cholangitis. Investigation with liver biopsy and endoscopic retrograde cholangiopancreatography should be considered if abnormal biochemical findings remain unexplained after a careful history and physical examination are performed, a thorough medication history is obtained and abdominal ultrasonography is conducted to search for biliary obstruction.