Alarm substance in Gyrinus aeratus (Coleoptera,Gyrinidae)

Gyrinid beetles are common in ponds and lakes in Sweden, where they aggregate in open areas of the surface. Gyrinid beetles have pygidial glands which produce compounds rendering them unpalatable to fish. This study examines whether the pygidial secretion can be used for alarm purposes in addition to other functions. Experiments showed that gyrinid beetles responded to water prepared with the pygidial compounds by evasive behaviour. The beetles did not respond when the compound was mediated by air. One component of the defense system of gyrinids is how they advertise their presence. The aggregation of dark beetles with their typical motion pattern when alerted is very conspicuous and easily identified by an experienced predator. We suggest that this aspect of gyrinid defence can be characterized as aposematic.     

Rotoitidae, a curious new family of Chalcidoidea (Hymenoptera) from New Zealand

Abstract. A new chalcidoid family, Rotoitidae fam.n., is described from New Zealand. The probable systematic affinities of Rotoitidae are discussed and the type genus and a single included species, Rotoita basalis gen. et sp.n., are described and illustrated.     

Expression and regulation of cyclic nucleotide phosphodiesterases in human and rat pancreatic islets

As shown by transgenic mouse models and by using phosphodiesterase 3 (PDE3) inhibitors, PDE3B has an important role in the regulation of insulin secretion in pancreatic β-cells. However, very little is known about the regulation of the enzyme. Here, we show that PDE3B is activated in response to high glucose, insulin and cAMP elevation in rat pancreatic islets and INS-1 (832/13) cells. Activation by glucose was not affected by the presence of diazoxide. PDE3B activation was coupled to an increase as well as a decrease in total phosphorylation of the enzyme. In addition to PDE3B, several other PDEs were detected in human pancreatic islets: PDE1, PDE3, PDE4C, PDE7A, PDE8A and PDE10A. We conclude that PDE3B is activated in response to agents relevant for β-cell function and that activation is linked to increased as well as decreased phosphorylation of the enzyme. Moreover, we conclude that several PDEs are present in human pancreatic islets.     

Absence of BoLA class I antigens on bovine spermatozoa

Summary. Forty AI bulls were tested for BoLA class I antigens by means of eight specific polyclonal reagents. By means of immobilization and sperm penetration tests these antigens were not detected on sperm cells. Isoimmunization studies with the use of sperm as antigenic stimuli and insemination of frozen spermatozoa diluted in specific reagents did not prove the presence of BoLA class I antigens on bovine spermatozoa. The cytotoxic tests used in this investigation were not reliable.     

AGE DEPENDENCE OF THE NUMBER OF THE STEM CELLS IN HAEMOPOIETIC TISSUES OF RATS

The number and concentration of haemopoietic stem cells in the femoral bone marrow and spleen of Wistar rats of different ages were investigated. Stem cells were assayed by the spleen colony technique in irradiated rat recipients. The ability of the recipient spleen to harvest transplanted tissue as a macroscopic colony was found to be dependent on the recipient's age. Changes with senescence were observed also in the concentration and the size of the stem cell compartment both in the marrow and spleen. No differences were demonstrated in the seeding of transplanted colony-forming units into the spleen of recipients of 1 and 4 months of age. A rats-mice strain difference in the effect of senescence on the haemopoietic stem cells is discussed.     

Fueling phocids: Divergent exploitation of primary energy sources and parallel ontogenetic diet switches among three species of subarctic seals

Determining how marine predators partition resources is hindered by the difficulty in obtaining information on diet and distribution. Stable isotopes (SI) of carbon (¹³C/¹²C, δ¹³C) and nitrogen (¹⁵N/¹⁴N, δ¹⁵N) provide a two‐dimensional estimate of the dietary space of consumers; an animal's isotopic composition is directly influenced by what they consume and where they feed. Harp (Pagophilus groenlandicus) and hooded (Cystophora cristata) seals are abundant phocid species found in the North Atlantic. We measured and contrasted SI values between seals sampled at nearshore and offshore sites to test for effects of sampling location, sex, age‐class, and body size to gain insight into how these species partition space and prey resources. In addition we contrasted previously published results for gray seals (Halichoerus grypus). Isotope values differed significantly by age class and location in harp and hooded seals. We found significant differences in SI values (mean δ¹³C and δ¹⁵N ± SE) between all species. Hooded seals, a continental shelf‐edge, deep‐diving species, exhibited low SI values (juveniles: ?20.9‰ ± 0.03‰, 13.36‰ ± 0.05‰; adults: ?20.41‰ ± 0.03‰, 14.81‰ ± 0.04‰) characteristic of feeding on meso‐ to bathypelagic prey. Harp seals, which dive to moderate depths primarily on the shelf had intermediate SI values (juveniles: ?20.53‰ ± 0.01‰, 13.91‰ ± 0.01‰; adults: ?20.13‰ ± 0.01‰, 14.96‰ ± 0.01‰) characteristic of feeding on epipelagic prey, whereas gray seals, which feed on or near the sea floor in shallow shelf waters, had high SI values (juveniles: ?19.74‰ ± 0.04‰, 17.51‰ ± 0.05‰; adults: ?18.86‰ ± 0.01‰, 17.23‰ ± 0.02‰) characteristic of feeding on demersal prey. In all species, δ¹³C values increased with body size and age in the same manner, indicating that seals exploit or forage in deeper habitats as they get larger and older. We hypothesize that the consistent ontogenetic shift in foraging niche, despite large differences between species in their diving behavior, geographic range and habitat use, not only reflects increased access to different prey due to increased diving capacity, but a progressive adjustment to balance energy budgets by reducing foraging costs.     

Effect of some analgesics on Paraoxonase-1 purified from human serum

The in vitro effects of the analgesic drugs, lornoxicam, indomethacin, tenoxicam, diclofenac sodium, ketoprofen and lincomycine, on the activity of purified human serum paraoxonase (hPON1) (EC 3.1.8.1.) were evaluated. hPON1 was purified from human serum with a final specific activity of 3840 U mg^?1 and a purity of 25.3 % using simple chromatographic methods, including DEAE-Sephadex anion exchange and Sepharose 4B-L-tyrozine-1-napthylamine hydrophobic interaction chromatography. SDS-polyacrylamide gel electrophoresis indicated a single protein band corresponding to hPON1. The six analgesics dose-dependently decreased in vitro hPON1 activity, with IC₅₀ values for lornoxicam, indomethacin, tenoxicam, diclofenac sodium, ketoprofen and lincomycine of 0.136, 0.195, 0.340, 1.639, 6.23 and 9.638 mM, respectively. K_i constants were 0.009, 0.097, 0.306, 0.805, 13.010 and 11.116 mM, respectively. Analgesics showed different inhibition mechanisms: lornoxicam, diclofenac sodium and lincomycine were uncompetitive, indomethacin and tenoxicam were competitive, ketoprofen was noncompetitive. According to the results, inhibition potency was lornoxicam>indomethacin>tenoxicam> diclofenac sodium>ketoprofen> lincomycine.     

The effects of kefir,koumiss, yogurt and commercial probiotic formulations on PPARα and PPAR-β/δ expressions in mouse kidney

Commercial probiotic capsules that contain probiotic bacteria, kefir, koumiss and yogurt contain beneficial microorganisms that affect cholesterol levels and immune response, and are used for treatment of some diseases. We investigated using immunohistochemistry the effects of kefir, koumiss, yogurt and a commercial probiotic formulation on the expression levels of peroxisome proliferator-activated receptor-α (PPARα) and peroxisome proliferator-activated receptor-β/δ (PPAR-β/δ), which are members of the nuclear steroid hormone receptor superfamily in mouse kidney. Mice were assigned to five groups: group 1, commercial probiotic capsules; group 2, kefir; group 3, koumiss; group 4, yogurt; group 5, control. After oral administration for 15 days, body weights were recorded and kidney tissue samples were obtained. Hematoxylin & eosin staining and the streptavidin-biotin peroxidase complex (ABC) method were applied to tissue sections to examine histology and to determine the localization of PPARα and PPAR-β/δ in the kidneys. We found that the weights of the mice in the kefir, koumiss, yogurt and commercial probiotic capsules groups were increased compared to controls. No differences in kidney histology were observed in any of the experimental groups. Kefir, koumiss, yogurt and the commercial probiotic preparation increased PPARα and PPAR-β/δ expressions.