Discrepancy of xenon concentrations between end-tidal and blood collection methods in xenon-enhanced computed tomographic measurement of cerebral blood flow

Summary Using xenon-enhanced computed tomography for the study of cerebral blood flow, simultaneous measurements of end-tidal and arterial blood xenon concentrations using the blood collection method were performed to investigate the validity of substituting the end-tidal for the arterial blood xenon concentration. Simultaneous measurement by both methods was performed 68 times in 27 patients. There was no statistical correlation between the arterial blood accumulation rate constant obtained by arterial blood and end-tidal samples, nor between the arterial blood saturation value obtained by the two methods, even when correction was made for age. In brain tissue, all parameters calculated using the end-tidal concentration were lower than those using arterial blood. We therefore suggest that cerebral blood flow values calculated using end-tidal xenon concentration are useful only for qualitative cerebral blood flow mapping, and not applicable to absolute values of cerebral blood flow.     

Analysis of lymph node metastatic pattern in relation to prognosis and recurrence in pN2 resected lung cancer patients]

Lymph node metastasis was analyzed quantitatively with 4 categories and relation to post surgical survival and recurrence pattern was studied in patients with pN2 primary lung cancer who underwent relatively curative or relatively noncurative resection of the tumors. There was no relation between metastatic coefficient and post surgical survival, however, better survival was observed when the metastatic ratio and metastatic frequency were low and metastatic mode was random or skip pattern rather than sequential pattern. Metastatic coefficient and metastatic frequency were higher in cases with recurrence in lymph nodes but the former was lower and the latter was higher in cases with recurrence in intra-pulmonary dissemination or metastasis. There was no relation between metastatic coefficient and distant metastasis but metastatic frequency was lower in cases with recurrence in distant metastasis. Cases with sequential lymph node metastasis showed a tendency of lymph node recurrence and intrapulmonary metastasis and those with random or skip metastasis of lymph nodes had a tendency of distant metastasis.     

Peritumoral brain edema associated with meningioma--histological study of the tumor margin and surrounding brain.

Thirty-nine cases of intracranial meningiomas were analyzed to identify factors causing brain edema. Edema was significantly correlated with tumor size and the destruction of the leptomeninges and cortex. Meningotheliomatous meningioma tended to have more peritumoral edema. There was no correlation between the presence of edema and location of the tumor or histological features including lymphocytic infiltration and the presence of glial fibrillary acidic protein-positive cells in the tumor tissue. Larger tumors destroy the leptomeninges and cerebral cortex, allowing direct transmission of humoral edema-promoting factor or edema fluid into the white matter, resulting in vasogenic edema.     

Mechanisms of long-lasting effects of benidipine on Ca current in guinea-pig ventricular cells.

1. Benidipine (KW-3049), a new derivative of 1,4-dihydropyridine (DHP), showed dose-dependent inhibition of Ca current (ICa) which was elicited by depolarization from -40 mV to +10 mV at 0.2 Hz in single cardiac cells isolated from guinea-pig ventricle under whole cell voltage clamp. Half inhibition doses (IC50) of benidipine and nifedipine for the peak ICa at +10 mV were 2.7 nM and 63.1 nM, respectively. 2. A change in holding potential from -40 to -75 mV partially removed the block induced by both 10 nM benidipine and 100 nM nifedipine. The block of ICa by benidipine strongly depended upon holding potentials as did that induced by nifedipine. 3. The effect of 100 nM nifedipine was mostly removed when the cells were kept quiescent at holding potentials negative to -75 mV for 5 min after withdrawal of nifedipine. In contrast, hyperpolarization for several minutes did not significantly accelerate the removal of benidipine-induced block after withdrawal of the drug. Effects of 10 nM benidipine could not be washed out for up to 30 min regardless of the holding potentials. 4. It is suggested that the dissociation of benidipine from the DHP binding site, like that of nifedipine, is greatly accelerated by hyperpolarization. Benidipine but not nifedipine may have an additional interaction with the channel or lipid membrane and cannot be washed away even after the dissociation. Alternatively, the dissociation of benidipine from the DHP binding site may be too slow to occur substantially during the limited period of hyperpolarization in the present study (less than 30 min).(ABSTRACT TRUNCATED AT 250 WORDS)     

Horseshoe anomaly of the pancreas.

A 72-year-old man with recurrent pancreatitis and a horseshoe-shaped anomaly of the pancreas is described. The diagnosis was made by endoscopic retrograde cholangiopancreatography (ERCP) and computed tomography scan; laparotomy was confirmatory. The abnormal duct branched to the lower left from an enlarged Santorini's duct; a thin Wirsung's duct was joined at its distal portion to the junction of the abnormal duct. The anomaly was associated with a cystic dilatation of the common bile duct with stone and cholecystolithiasis. This anomaly is considered to be a variation of the dominant dorsal duct syndrome.