Leukocyte filtration improves brain protection after a prolonged period of hypothermic circulatory arrest: A study in a chronic porcine model.

BACKGROUND: Ischemic cerebral injury follows a well-attested sequence of events, including 3 phases: depolarization, biochemical cascade, and reperfusion injury. Leukocyte infiltration and cytokine-mediated inflammatory reaction are known to play a pivotal role in the reperfusion phase. These events exacerbate the brain injury by impairing the normal microvascular perfusion and through the release of cytotoxic enzymes. The aim of the present study was to determine whether a leukocyte-depleting filter (LeukoGuard LG6, Pall Biomedical, Portsmouth, United Kingdom) could improve the cerebral outcome after hypothermic circulatory arrest. METHODS: Twenty pigs (23-30 kg) were randomly assigned to undergo cardiopulmonary bypass with or without a leukocyte-depleting filter before and after a 75-minute period of hypothermic circulatory arrest at 20 degrees C. Electroencephalographic recovery, S-100beta protein levels, and cytokine levels (interleukin 1beta, interleukin 8, and tumor necrosis factor alpha) were recorded up to the first postoperative day. Postoperatively, all animals were evaluated daily until death or until electively being put to death on day 7 by using a quantitative behavioral score. A postmortem histologic analysis of the brain was carried out on all animals. RESULTS: The rate of mortality was 2 of 10 in the leukocyte-depletion group and 5 of 10 in control animals. The risk for early death in control animals was 2.5 (95% confidence interval, 0.63-10.0) times higher than that of the leukocyte-depleted animals. The median behavioral score at day 7 was higher in the leukocyte-depletion group (8.5 vs 3.5; P =.04). The median of total histopathologic score was 8.5 in the leukocyte-depletion group and 15.5 in the control group (P =.005). CONCLUSION: A leukocyte-depleting filter improves brain protection after a prolonged period of hypothermic circulatory arrest.

Incorporation of selenium-75 into seminal plasma and spermatozoa of the bull.

75Se was given intravenously into 5 bulls. Multiple blood and semen samples were taken and during slaughter 5, 10, 15, 20 and 80 days later samples of various reproductive and other organs were collected. After injection, 75Se in blood reached a peak at 6 h followed by a rapid decline. The label was mainly found in serum with very low levels in erythrocytes. Initially the serum 75Se was bound to a macromolecule with a mw of 80 kDa, but later a larger molecule (100 kDa) was observed. In semen 75Se was first mainly found in seminal plasma, where a plateau level was reached at 5 d followed by a gradual decline after 12 d. The total semen level, however, increased after 14 d and this increase was due to a rapid appearance of the label in spermatozoa. The sperm 75Se level reached a plateau at 20 d and remained high until 40 days, after which a gradual decline ensued. The seminal plasma 75Se eluted in gel filtration coincident with glutathione peroxidase. The highest levels of 75Se were found in the kidney followed by seminal vesicles and testicles. The seminal vesicle secretion was particularly rich in 75Se and its fractionation resembled that of the seminal plasma. 75Se appeared in the epididymal caput within 5 days and passed through the epididymis in 20 days. It is concluded that 75Se is actively incorporated in the bull seminal vesicles into GSH-Px, while in the testis it is incorporated into a structural sperm protein during spermatogenesis.

Ultrastructure of a tail stump sperm defect in an Ayrshire bull.

The sperm cells in the ejaculate of a sterile Ayrshire bull were studied by light microscopy as well as scanning and transmission electron microscopy. The spermatozoa showed an almost total lack of tails, whereas the heads appeared morphologically normal. The cytoplasmic residue at the caudal end of the head contained numerous membrane structures as well as mitochondria and incomplete elements of the proximal centriole and striated column. The basic disturbance appears to be a hereditary defect in the spermiogenesis.

Familial undulatory nystagmus in Ayrshire bulls in Finland.

The article describes a familial, undulatory nystagmus in Finnish Ayrshire bulls. The nystagmus appeared as a high-frequency tremor with a small amplitude and it was similar in both eyes. The vision didn't seem to be affected. In three of the affected five bulls a slight paramyoclonia posterior ('stretches') was also noticed. A histological examination of the vestibular nuclei with the adjacent brain area revealed no abnormalities. The pedigree of the bulls suggests a recessive autosomal inheritance.

Selenium in reproductive organs, seminal fluid and serum of men and bulls.

The concentrations of selenium in the reproductive organs, seminal fluid and serum of human males and bulls were analysed using an atomic absorption spectrometer with Zeeman background correction. The mean (+/- SD) concentration of selenium in human seminal fluid (33.4 +/- 14.1 micrograms/l, n = 70) was less than half the level detected in serum (78.2 +/- 9.9 micrograms/l, n = 32). In bulls, the mean selenium concentration in seminal fluid (457.4 +/- 108.7 micrograms/l, n = 113) was about nine times higher than in human males, while the level in serum (49.1 +/- 5.1 micrograms/l, n = 94) was significantly (P less than 0.001) lower than in human serum. The selenium concentration (500 +/- 244 micrograms/l) in the bovine seminal vesicle secretions were comparable to those in the seminal fluid and this gland appears to be mainly responsible for the high selenium levels in the seminal fluid. The mean selenium concentration in reproductive tissues of both species was highest in the testes. The distribution of selenium in the bovine epididymis was biphasic. The testicular and epididymal selenium are associated mainly with macromolecules of the spermatogenic cells and spermatozoa. It was concluded that studies in farm and laboratory animals do not necessarily form a reliable basis for conclusions with regard to human male reproduction, since selenium may have a different role and importance in the reproduction of various species.