Congener-specific profile and toxicity assessment of PCBs in green turtles (Chelonia mydas) from the Hawaiian Islands.

Chemical pollution may play a role in the etiology of fibropapillomatosis in green turtles (Chelonia mydas). In this preliminary study, polychlorinated biphenyls (PCBs) were measured in the livers and adipose fats of green turtles collected after they were stranded on Oahu Island, Hawaii in 1992-1993. Average concentrations of total PCBs were 45-58 ng/g dry weight and 73-665 ng/g in the liver and adipose tissues, respectively. Hexachlorobiphenyls were predominant homologues, PCBs 153 and 138 were dominant congeners in all the turtle tissues. Among the most toxic coplanar congeners, in the order of abundance, were PCB 77 > 126 > 169. Estimated toxic equivalents (TEQs) of PCBs to 2,3,7,8-tetrachlorodibenzo-p-dioxin were 8-15 pg/g in the livers and 13-48 pg/g in the adipose tissues. PCB 126 contributed 85-91% of the total TEQs.

[Assessment of left ventricular contraction with LV Emax during cardiopulmonary bypass in patients with open heart surgery].

There are few reports on the assessment of left ventricular contraction during cardiopulmonary bypass (CPB) in open heart surgery. LV Emax is thought to be a load-independent index of left ventricular function. We used a left ventricular conductance catheter to measure LV Emax from "non-working beating heart" during CPB in 16 patients who underwent open heart surgery. During CPB, at 45 minutes after aortic declamping, changes of heart rate with atrial pacing (120/min) did not change LV Emax, but after intravenous dobutamine administration (DOB, 10 micrograms/kg/min) LV Emax increased by 26% (p < 0.01). DOB increased LV Emax in 14 of 16 patients during CPB. These 14 patients were weaned from CPB without difficulty. But in 2 other patients DOB didn't increase LV Emax during CPB. In order to be weaned from CPB, the two patients needed epinephrine and intraaortic balloon pumping. We concluded that change of LV Emax made by intravenous administration of dobutamine is one of useful indexes to assess left ventricular contractility during cardiopulmonary bypass.

[Intraoperative assessment of left ventricular function with left ventricular pressure-volume relationships in patients with open heart surgery].

There are few reports on the assessment of the left ventricular function from left pressure-volume relationships intraoperatively in open heart surgery. LV Emax, Ea/Ees and EW/PVA efficiency were assessed intraoperatively by using a left ventricular conductance catheter in patients with aortocoronary bypass. After dobutamine administration (DOB, 10 micrograms/kg/min), LV Emax was increased by 33 +/- 23% during cardiopulmonary bypass (CPB) and 60 +/- 38% after weaning from CPB. Ea/Ees changed from 2.14 +/- 1.36 to 1.08 +/- 0.47 after weaning from CPB with dobutamine administration. EW/PVA efficiency changed from 52 +/- 12% to 66 +/- 10%. The change of LV Emax after dobutamine administration was correlated with the change of LV Emax after weaning from CPB and was correlated with Ea/Ees and EW/PVA efficiency after weaning from CPB. We concluded that measuring LV Emax before and after dobutamine administration during CPB is useful to assess left ventricular contraction clinically.