Per- and polyfluoroalkyl substances (PFAS), trace elements and life history parameters of mass-stranded common dolphins (Delphinus delphis) in New Zealand

Profiles of 33 PFAS analytes and 12 essential and non-essential trace elements were measured in livers of stranded common dolphins (Delphinus delphis) from New Zealand. PFAS concentrations reported were largely comparable to those measured in other marine mammal species globally and composed mostly of long-chain compounds including perfluorooctanesulfonic acid (PFOS), perfluorododecanoic acid (PFDoDA), perfluorotridecanoic acid (PFTrDA) and perfluorooctanesulfonamide (FOSA). PFAS profiles did not vary significantly by location, body condition, or life history. Notably, significant positive correlations were observed within respective PFAS and trace elements. However, only negative correlations were evident between these two contaminant types, suggesting different exposure and metabolic pathways. Age-associated concentrations were found for PFTrDA and four trace elements, i.e. silver, mercury, cadmium, selenium, indicating differences in the bioaccumulation biomagnification mechanisms. Overall, our results contribute to global understanding of accumulation of PFAS by offering first insights of PFAS exposure in cetaceans living within South Pacific Australasian waters.

Mechanobiology of the intervertebral disc

Intervertebral disc degeneration has been linked in humans to extreme spinal loading regimens. However, mechanisms by which spinal force influences disc cellularity, morphology and consequently biomechanical function are unclear. To gain insight into mechanobiological interactions within the disc, we developed an in vivo murine tail-compression model. Results from this model demonstrate how deviations in spinal stress induce a cycle of altered cell function and morphology as the disc remodels to a new homoeostatic configuration.

STUDIES OF TOTAL ERYTHROCYTE AND LEUCOCYTE COUNTS OF FOWLS: IV. ERYTHROCYTE AND LEUCOCYTE COUNTS OF BIRDS RAISED IN CONFINEMENT

Erythrocyte and leucocyte counts were made of 65 S.C White Leghorn females and 50 S.C. White Leghorn males which were raised in confinement from the age of one day until sexual maturity.The mean erythrocyte count of the males was significantly higher than the mean of the females. There was no significant difference between the mean leucocyte counts of the males and the females. The erythrocyte counts of the confined birds were significantly lower than those of normal birds kept under natural conditions and those of one- to two-day-old chicks, while the leucocyte counts were significantly higher.

STUDIES OF TOTAL ERYTHROCYTE AND LEUCOCYTE COUNTS OF FOWLS: III. VARIATION IN NUMBER OF BLOOD CELLS OF NORMAL FOWL

Following the technique recommended by Shaw in which the erythrocytes and leucocytes are counted in the same chamber, the authors made total erythrocyte and leucocyte counts of 100 apparently healthy and vigorous single-comb White Leghorn hens. Following the counts, post-mortem examinations did not reveal any striking abnormalities. With few exceptions the birds were singularly free from intestinal parasites.The range of the erythrocyte counts was found to be 1,805,000 to 3,845,000, and of leucocyte counts 18,330 to 49,000. The data are analyzed statistically.In respect to the erythrocyte counts, the authors' data are in complete agreement with the recent studies by Cook and Dearstyne of 75 female birds. There is, however, a marked difference in the range (3,000–47,000) and the mean of the leucocyte counts, which may be due to the different technique employed by Cooke and Dearstyne.Total erythrocyte and leucocyte counts were also made of 47 one- to two-day-old chicks. The range of the erythrocyte counts was found to be 1,800,000 to 3,180,000 and of the leucocyte counts 15,000 to 28,330. A statistical analysis of the data is presented. In the case of the baby chicks, since the environmental conditions are relatively uniform, it would appear that factors other than environment affect the total erythrocyte and leucocyte counts of individual chicks.