Coaccumulation of cadmium and zinc in tissues of sentinel mallards (Anas platyrhynchos) using a former dredge-disposal impoundment.

Six- to eight-month-old female farm-raised mallards (Anas platyrhynchos) were used to examine the accumulation of and association among cadmium (Cd), zinc (Zn), and copper (Cu) from an impoundment constructed to contain sediments dredged from a lake contaminated by a zinc smelter. Cd was not detectable in the livers t of farm-raised mallards (day 0), although sentinel mallards accumulated hepatic Cd in the first 7 days after release. By day 14, mean concentrations of Cd in kidneys (= 2.82 mg/kg wet weight) had increased 3.4-fold. The mean pancreatic Cd concentration increased 59% between days 7 and 14. Renal Zn increased nominally, whereas pancreatic Zn increased 63% in sentinel ducks after release. Hepatic Zn increased significantly in the first week of release. Renal and pancreatic Cu concentrations did not change significantly, whereas concentrations of Cu in livers of ducks increased 50% in the 7 days after release before decreasing by nearly the same degree. Concentrations of Cd and Zn were correlated in livers of sentinel mallards on days 7 and 14. Cd and Cu were not correlated in the tissues of any cohort. Cu and Zn were correlated in the livers of farm-raised mallards, in the pancreases of sentinel mallards at day 7, and in the kidneys of the ducks in all three treatments. The relationship between Cd and Zn in tissues of ducks in our study was complicated by simultaneous exposure to increased and heterogeneous concentrations of Cd and Zn, both of which can induce metallothionein and compete for this and other ligands.

Use of a simulated gizzard to measure bioavailability of metals and other elements to waterfowl.

We used a simulated gizzard environment to examine the bioavailability of barium, cadmium, copper, lead and zinc to wild and sentinel mallards (Anas platyrhynchos) using a seasonally-flooded wetland. This impoundment was originally constructed as a containment area for dredged sediments which were contaminated through previous smelting operations. Extraction of elements from gizzard contents indicated that sentinel mallards experienced greater exposure to contaminants than their wild counterparts. Concentrations of the selected elements extracted from ingesta were lower than in seeds and sediments from the study site. Notable exceptions were barium and lead, which were not detected in seeds of some plant species, though they were present in the ingesta of one or more treatment groups. This technique may provide a more realistic means of estimating bioavailability and exposure than methods which measure total concentrations of elements in dietary components. The use of sentinel mallards may result in inflated estimates of risk to wild ducks using seasonally-available wetlands.

Effects of lead, iron, and bismuth alloy shot embedded in the breast muscles of game-farm mallards.

Effects of five lead (Pb), iron (Fe), or bismuth (Bi)/tin (Sn) alloy shot embedded in the breast muscles of game-farm mallards (Anas platyrhynchos) were studied from 28 March 1994 through 27 March 1995. We detected no differences in the mean survival times, mean hematocrits, or mean body weights among the three shot types. Connective tissue encapsulated Pb and Bi/Sn shot but only slight changes occurred in tissues surrounding the shot. Recovered Pb and Bi/Sn shot were essentially unchanged in appearance and weight. A thin zone of "oxide" surrounded Fe shot with a slight inflammatory response and a small amount of scarring adjacent to the embedded shot. Fe shot decreased slightly in weight while embedded. Bacterial infections were absent in all dosed ducks. Mean weights of kidneys, livers, and gonads did not vary by type of shot. Kidneys and livers of Bi-dosed ducks had higher concentrations of Bi than in Pb- and Fe-dosed ducks. Muscle and blood showed no differences in Bi concentrations among doses. We found no histological dose-related effects in kidneys, liver, and gonads from the embedded shot.

Balloon embolectomy catheter-induced arterial injury: a comparison of four catheters.

This study compared four brands of balloon embolectomy catheters with respect to their mechanical characteristics and the histologic responses they elicit. Seventy-two 4F Becton-Dickinson, Edwards, Electro-Catheter, and Shiley catheters were studied. In vitro studies of penetration forces demonstrated that the forces required for arterial puncture were greatest for Shiley (295 +/- 22 gm) and least for Edwards catheter tips (217 +/- 11 gm) (p less than 0.05). This indicates that the Shiley catheter is least likely to puncture vessels in patients. Studies of balloon eccentricity showed that none of the balloons distended with excessive eccentricity. Studies of balloon emptying time demonstrated that the silicon Becton-Dickinson balloon required more than two times as long (5.7 +/- 1.2 seconds) as all other balloons to empty. Balloon emptying time reflects the ability of the surgeon to rapidly adapt the balloon to changing vessel diameter in patients. Shear forces were studied in cylindrical segments of arteries in vitro. Initial shear forces were significantly different among all catheters, Becton-Dickinson greater than Edwards greater than Shiley greater than Electro-Catheter (p less than 0.05). In contrast, during catheter withdrawal dynamic shear forces were similar among the four brands of catheters. Balloon embolectomies were performed in vivo in the common carotid and common femoral arteries in 18 anesthetized dogs. Histologic examinations of the vessels exposed to 50, 100, and 200 gm shear forces showed that myointimal hyperplasia increased with rising shear forces for all catheters (p less than 0.05), but that there were no differences in the degree of myointimal hyperplasia elicited by the different brands of catheters.(ABSTRACT TRUNCATED AT 250 WORDS)

Early myointimal hyperplasia after balloon catheter embolectomy: effect of shear forces and multiple withdrawals.

Arterial stenosis occurring after balloon catheter embolectomy may be caused by myointimal hyperplasia (MIH). This study investigated the effects of shear force and repeated catheter withdrawals on the development of MIH after embolectomy. The procedures were performed in the common carotid and common femoral arteries of 18 anesthetized dogs. During catheter withdrawal, the balloons were filled gradually to produce shear forces rising smoothly from 50 to 200 gm. Four weeks after embolectomy, the vessels were perfusion-fixed in situ with 2% glutaraldehyde and were excised. The thickness and circumferential extent of MIH were measured in cross sections from segments of the vessels exposed to shear forces of 50, 100, and 200 gm. Sixty-nine of 72 arteries remained patent. Low shear force (50 gm) consistently elicited less MIH than did higher shear forces (p less than 0.05). At each level of shear force, repeated withdrawals resulted in greater circumferential extent of MIH than did single withdrawals (p less than 0.005). Although clinically it usually is necessary to perform multiple passes during balloon embolectomy, these data suggest that, in humans, attempts should be made to perform a minimal number of catheter withdrawals at low shear force to minimize the subsequent development of MIH.

High concordance between marker profiles of 22 human leukemia-lymphoma cell lines tested with the same monoclonal antibodies before and during the second international workshop on human differentiation antigens.

Our laboratory participated in the Second International Workshop and Conference on Human Leucocyte Differentiation Antigens. In this international study the reactivity profiles of monoclonal antibodies were analyzed on normal and malignant hematopoietic cells. The Workshop was divided into three categories: the T-cell, B-cell and myelomonocytic cell studies. We blindly tested 159 coded monoclonal antibodies of the panel for the T-cell study on 22 permanently established leukemia cell lines. The monoclonal antibodies were provided by the Workshop Committee and their reactivity with the target cells was visualized by standardized indirect immunofluorescence. After decoding it was recognized that 11 monoclonal antibodies had been examined on these cell lines prior to the Workshop. The reactivity of these 11 monoclonal antibodies was analyzed and compared with the earlier results. From a total of 217 paired tests done blindly in the Workshop study and prior to the Workshop, 191 tests (88%) did not show significantly different data. The possible reasons for discrepancies include nonspecific Fc-receptor-binding on some cell lines and a relatively nonspecific reactivity of some monoclonal antibodies. This analysis demonstrates the stability of the antigen expression on human leukemia-lymphoma cell lines grown at consistently optimal conditions, for the tests, using the same monoclonal antibodies as in the Workshop, had been performed 0.5-5 years prior to the Workshop study. On the other hand, nonspecific Fc-binding, wide "specificity" of monoclonal antibodies and a shift in antigen expression of the cells (due to poor growth conditions, involuntary induction of differentiation and other factors) must be taken into consideration upon immunological analysis.