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Biomedical subjects

T Ohata

Publications and source records attributed to T Ohata.

At least 73 records · Page 4Linked to original sources

Determination of urinary free cortisol by high performance liquid chromatography with sulphuric acid-ethanol derivatization and column switching.

A rapid and highly sensitive determination method for urinary free cortisol has been developed using reversed phase high performance liquid chromatography (HPLC) with a precolumn for sulphuric acid-ethanol fluorescence derivatization and column switching. Urinary cortisol, eluted from the octadecylsilane-bonded silica (ODS) minicolumn with 90% aqueous ethanol, was derivatized with the addition of sulphuric acid only at ambient temperature. Cortisol derivatives injected directly onto the ODS precolumn were purified on-line. After switching the columns, the cortisol derivative was separated on an ODS analytical column with a retention time of 15.3 min and monitored at an emission wavelength of 520 nm (exitation wavelength of 365 nm) to decrease the detection limit to 0.26 microgram/dL (signal-to-noise ratio = 3). The automated HPLC operation resulted in good reproducibility and recovery of the stable cortisol derivative at 5 degrees C.

Chromatography, High Pressure Liquid↗

Normothermia has beneficial effects in cardiopulmonary bypass attenuating inflammatory reactions.

"Post perfusion syndrome" after cardiopulmonary bypass (CPB) has been known to be evoked by inflammatory reactions. To elucidate the effect of perfusate temperature during CPB on subsequent inflammatory reactions, serum levels of interleukin (IL)-6, IL-8, tumor necrosis factor-alpha, IL-1 beta, and polymorphonuclear (PMN) elastase were measured before and after (0, 12 hours, and 24 hours after) CPB in adult patients undergoing cardiac operations. Patients were divided into two groups: the normothermic CPB group (NOR, 34 degrees C perfusate temperature, n = 8) and hypothermic CPB group (HYP, 28 degrees C perfusate temperature, n = 8). In both groups, IL-6, IL-8, and PMN elastase levels were elevated during CPB, while the increase of tumor necrosis factor-alpha and IL-1 beta was not detected. The increase in IL-8 and PMN elastase levels at 12 hours after CPB was significantly less in NOR than in HYP (IL-8; NOR versus HYP, 15.1 +/- 12.9 versus 62.5 +/- 30.6 pg/ml, p < 0.05, PMN elastase; 394 +/- 200 versus 1085 +/- 523 micrograms/L, p < 0.05) while neither group showed any difference in IL-8 and PMN elastase at 24 hours after CPB. There was no difference in IL-6 between the two groups, and no significant increase in tumor necrosis factor-alpha and IL-1 beta levels were detected in either group after CPB. These results demonstrate that although CPB activated inflammatory reactions detected by IL-8 and PMN elastase activity, post operative persistence of these reactions were attenuated by warm CPB.

Adult↗

Hemodynamic effect of inhaled nitric oxide in dilated cardiomyopathy patients on LVAD support.

Recently it has been shown that inhaled nitric oxide (NO), which has been proven to contribute to improvement in critical pulmonary hypertension, may provide a favorable effect early after left ventricular assist device (LVAD) support. To improve right ventricular function, inhalation of NO was added to treatment with conventional catecholamines for four consecutive dilated cardiomyopathy (DCM) patients following institution of LVAD. In two patients 1 hr after inhalation of NO, central venous pressure (CVP), mean pulmonary arterial pressure (PAm), and pulmonary vascular resistance (PVR) were improved. These results led to better LVAD output and resulted in an adequate cardiac index. On the other hand, a right VAD (RVAD) was implemented in one patient whose high CVP, PAm, and PVR continued; he was weaned after 8 days of RVAD support. Another patient who had a high CVP but normal PAm and PVR before and after inhalation of NO had no improvement in his hemodynamic state. These data suggest that inhaled NO may improve systemic circulation by reducing right ventricular afterload and may become a promising and convenient therapy before placing RVAD in DCM patients under LVAD support. RVAD should be conducted in patients with right ventricular failure or when pulmonary hypertension is associated with impaired right ventricular reserve, even after inhalation of NO.

Administration, Inhalation↗