Prolonged cardiac xenograft survival in guinea pig-to-rat model by a highly active cobra venom factor

A highly active cobra venom factor (CVF) was isolated from the venom of Naja kaouthia by sequential column chromatography. It displays strong anticomplementary activity, and has 1515 U of anti complementary activity per mg protein. A single dose of 0.1 mg/kg CVF given i.v. to rats completely abrogated complement activity for nearly 5 days. Given 0.02 mg/kg of CVF. the complement activity of rats was reduced by more than 96.5% in 6 It. In guinea pig-to-rat heart transplant model, rats treated with a single dose of 0.05 mg/kg CVF had significantly prolonged xenograft survival (56.12 +/- 6.27 h in CVF-treated rats vs. 0.19 +/- 0.07 h in control rats, P < 0.001). (C) 2003 Elsevier Ltd. All rights reserved.

TMVA, a novel GPIb-binding protein, significantly prevents platelet microthrombi formation and prolongs discordant cardiac xenograft survival

In xenotransplantation, donor endothelium is the first target of immunological attack. Activation of the endothelial cell by preformed natural antibodies leads to platelet binding via the interaction of the glycoprotein (GP) Ib and von Willebrand factor (vWF). TMVA is a novel GPIb-binding protein purified from the venom of Trimeresurus mucrosquamatus. In this study, the inhibitory effect of TMVA on platelet aggregation in rats and the effect on discordant guinea pig-to-rat cardiac xenograft survival were investigated. Three doses (8, 20 or 40 mug/kg) of TMVA were infused intravenously to 30 rats respectively. Platelet aggregation rate was assayed 0.5, 12, and 24 h after TMVA administration. Wister rats underwent guinea pig cardiac cervical heterotopic transplantation using single dosing of TMVA (20 mug/kg, i.v., 0.5 h before reperfusion). Additionally, levels of TXB2 and 6-keto-PGF(1alpha) within rejected graft tissues were determined by radioimmunoassay. Treatment with TMVA at a dose of 20 or 40 mug/kg resulted in complete inhibition of platelet aggregation 0.5 h after TMVA administration. Rats receiving guinea pig cardiac xenografts after TMVA therapy had significantly prolonged xenograft survival. Histologic and immunopathologic analysis of cardiac xenografts in TMVA treatment group showed no intragraft platelet microthrombi formation and fibrin deposition. Additionally, the ratio of 6-keto-PGF(1alpha) to TXB2 in TMVA treatment group was significantly higher than those in control group. We conclude that the use of this novel GPIb-binding protein was very effective in preventing platelet microthrombi formation and fibrin deposition in a guinea pig-to-rat model and resulted in prolongation of xenograft survival. The increased ratio of PGI(2)/TXA(2) in TMVA treatment group may protect xenografts from the endothelial cell activation and contribute to the prolongation of xenograft survival.

Medaka vasa is required for migration but not survival of primordial germ cells

Vasa is essential for germline development. However, the precise processes in which vasa involves vary considerably in diverse animal phyla. Here we show that vasa is required for primordial germ cell (PGC) migration in the medakafish. vasa knockdown by two morpholinos led to the PGC migration defect that was rescued by coinjection of Vasa RNA. Interestingly, Vasa knockdown did not alter the PGC number, identity, proliferation and motility even at ectopic locations. We established a cell culture system for tracing PGCs at the single cell level in vitro. In this culture system, control and morpholino-injected gastrulae produced the same PGC number and the same time course of PGC survival. importantly, vasa-depleted PGCs in culture had similar motility and locomotion to normal PGCs. Expression patterns of wt1a, sdf1b and cxcT4b in migratory tissues remained unchanged by Vasa knockdown. By chimera formation we show that PGCs from vasa-depleted blastulae failed to migrate properly in the normal environment, whereas control PGCs migrated normally in vasa-disrupted embryos. Furthermore, ectopic PGCs in vasa-depleted embryos also retained all the PGC properties examined. Taken together, medaka vasa is cell-autonomously required for PGC migration, but dispensable to PGC proliferation, motility, identity and survival. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

Predominant expression and cellular distribution of fish Agr2 in renal collecting system

Anterior gradient 2 (Agr2) genes encode secretory proteins, and play significant roles in anterior-posterior patterning and tumor metastasis. Agr2 transcripts were shown to display quite diverse tissue distribution in different species, and little was known about the cellular localization of Agr2 proteins. In this study, we identified an Agr2 homologue from gibe[ carp (Carassius auratus gibelio), and revealed the expression patterns and cellular localization during embryogenesis and in adult tissues. The full-length cDNA of CagAgr2 is 803 nucleotides (nt) with an open reading frame of 510 nt encoding 169 amino acids. The Agr2 C-terminus matches to the class I PDZ-interacting motif, suggesting that it might be a PDZ-binding protein. During embryogenesis, CagAgr2 was found to be transcribed in the mucus-secreting hatching gland from tailbud stage and later in the pharynx region, swim bladder and pronephric duct as revealed by RT-PCR and whole mount in situ hybridization. In the adult fish, its transcription was predominantly confined to the kidney, and lower transcription levels were also found in the intestine, ovary and gills. To further localize the Agr2 protein, the anti-CagAgr2 polyclonal antibody was produced and used for immunofluorescence observation. In agreement with mRNA expression data, the Agr2 protein was localized in the pronephric duct of 3dph larvae. In adult fish, Agr2 protein expression is confined to the renal collecting system with asymmetric distribution along the apical-basolateral axis. The data provided suggestive evidence that fish Agr2 might be involved in differentiation and secretory functions of kidney epithelium. (C) 2009 Elsevier Inc. All rights reserved.

Chronic effects of water-borne PFOS exposure on growth, survival and hepatotoxicity in zebrafish: A partial life-cycle test

Perfluorooctane sulfonate (PFOS) is widely distributed and persistent in the environment and wildlife. The main aim of this study was to investigate the impact of long-term exposure to low concentrations of PFOS in zebrafish. Zebrafish fry (F-0, 14d post-fertilization, dpf) were exposed via the water for 70d to 0 (control), 10, 50 and 250 mu g L-1 PFOS, followed by a further 30d to assess recovery in clean water. The effects on survival and growth parameters and liver histopathology were assessed. Although growth suppression (weight and length) was observed in fish treated with high concentrations PFOS during the exposure period, no mortality was observed throughout the 70d experiment. Embryos and larvae (F-1) derived from maternal exposure suffered malformation and mortality. Exposure to 50 and 250 mu g L-1 PFOS could inhibit the growth of the gonads (GSI) in the female zebrafish. Histopathological alterations, primary with lipid droplets accumulation, were most prominently seen in the liver of males and the changes were not reversible, even after the fish were allowed to recover for 30d in clean water. The triiodothyronine (T-3)) levels were not significantly changed in any of the exposure groups. Hepatic vitellogenin (VTG) gene expression was significantly up-regulated in both male and female zebrafish, but the sex ratio was not altered. The overall results suggested that lower concentrations of PFOS in maternal exposure could result in offspring deformation and mortality. (c) 2008 Elsevier Ltd. All rights reserved.

Experimental studies on the effects of toxic Microcystis aeruginosa PCC7820 on the survival and reproduction of two freshwater rotifers Brachionus calyciflorus and Brachionus rubens

Blooms of Microcystis aeruginosa frequently occur in many eutrophic lakes in China, however, there is very little experimental study on the relationship between Microcystis and rotifers from Chinese waters. The effects of different concentrations of toxic M. aeruginosa PCC7820 on two common freshwater rotifers Brachionus calyciflorus and B. rubens were investigated in laboratory experiments. B. calyciflorus was able to utilize this strain of M. aeruginosa as a food source. However, M. aeruginosa suppressed the survival and reproduction of B. calyciflorus at the highest concentration (10(6) cells/ml) probably due to the inadequate nutrition. B. rubens was inhibited by toxic M. aeruginosa PCC7820 and the inhibition increased with the increasing Microcystis concentration. Our study indicates that the two rotifers have different sensitivities to toxic M. aeruginosa and that toxic cyanobacteria may affect zooplankton community structure by differentially inhibiting the different zooplankton taxa.

Effects of live food and formulated diets on survival, growth and protein content of first-feeding larvae of Plelteobagrus fulvidraco

In recent years, much progress has been made in the rearing of fish larvae fed only artificial diets. A preliminary study was made in an attempt to evaluate the effects of live food and formulated diets on survival, growth and body protein content of first-feeding larvae of Plelteobagrus fulvidraco. Three test diets varying in protein level were formulated: Feed 1 containing 45% protein, Feed 2 with 50% protein and Feed 3 with 55% protein. Larvae fed live food (newly hatched Artemia, unenriched) were the control. The experiment started 3 days post-hatch and lasted for 23 days. At the end of the 23-day trial, survival was best in the control group (65.6%) whereby the final body weight and specific growth rate (SGR) were significantly lower than those in the test feed groups. At the same time, coefficients of variation for SGR and final body weight in the test groups were significantly higher than those in the control. Whole body protein content in all treatments showed a similar tendency during development: significantly higher 3 days post-hatch, then decreasing significantly, and then increasing unstatistically 10 days post-hatch. All results suggest that live food is still better for first-feeding larvae of P. fulvidraco, since live food leads to healthier larvae growth.

Effects of salinity on food intake, growth, and survival of pufferfish (Fugu obscurus)

The food intake, growth, food conversion ratio and survival of yearling pufferfish, Fugu obscurus Abe, were investigated under different water salinity conditions over a 54-day period. Within the salinity regimes of 0 (freshwater), 8, 18, and 35parts per thousand, the food intake levels were 0.97%, 1.43%, 1.19% and 1.01%, respectively; food conversion ratios were 1.31, 1.93, 1.61 and 1.36, respectively; and specific growth rates were 0.41%, 1.15%, 0.84%, and 0.35%, respectively. The three data series were reduced with increasing salinity. However, the survival rates did not show the same tendencies, which were 80%, 100%, 100%, and 67%, respectively. There were significant differences among the treatments. In conclusion, the yearling pufferfish optimum culture salinity condition was about 8parts per thousand.

The precocious Chinese mitten crab: Changes of gonad, survival rate, and life span in a freshwater lake

Changes of the gonad. survival rate, and life span of the precocious (i.e., sexually mature in their first October-November, at the age of 5 or 6 months) Chinese mitten crab (Eriocheir sinensis) were studied in a small, shallow, macrophytic, freshwater lake along the middle reaches of the Changjiang River, China. The gonosomatic index (GSI) reached peak during the next March when the female GSI was 12.32 +/- 1.75 SD% and the male GSI A as 4.24 +/- 0.19%. The sexual glands degraded from then on. In the first ten-day period of the following July, there was no complete ovum in the ovary. and the sperm became thin and lost adhesion. The population declined sharply from November to July, and the last one (a female) died in the middle of July, which indicated that the life span of the precocious crab was about 12 months (from larval hatching in June to death in July of next year). The survival curve might be expressed as Y = 1.09exp(-0.018x) (Y survival rate; x: days) for the precocious crabs stocked in experimental cages.

Survival, growth, sex ratio, and maturity of the Chinese mitten crab (Eriocheir sinensis) reared in a Chinese pond

Aspects of the biology of pond-cultured Chinese mitten crab (Eriocheir sinensis H. Milne-Edwards) were studied from June to November 1993. The survival rate of the population was estimated at 18.6%, and there was no significant difference between sexes in growth (t-test, P > 0.05). As the crabs grew from 7.3 to 33.8 mm in mean carapace length, seven molts were observed for the population. The intermolt period ranged from seven to 22 days and lengthened with increased size. Sex ratio at each sampling time did not differ significantly from 1:1 (Chi-square test, P > 0.05). Female crabs presumably required about eleven postlarval molts to reach sexually mature size, which was 34.1 +/- 3.9 (SD) mm. in carapace length in this study.

Independent adaptation to riverine habitats allowed survival of ancient cetacean lineages

The four species of "river dolphins" are associated with six separate great river systems on three subcontinents and have been grouped for more than a century into a single taxon based on their similar appearance. However, several morphologists recently questioned the monophyly of that group. By using phylogenetic analyses of nucleotide sequences from three mitochondrial and two nuclear genes, we demonstrate with statistical significance that extant river dolphins are not monophyletic and suggest that they are relict species whose adaptation to riverine habitats incidentally insured their survival against major environmental changes in the marine ecosystem or the emergence of Delphinidae.

The influence of fractionation on cell survival and premature differentiation after carbon ion irradiation

Carbon ion radiotherapy/Fractionated irradiation/R-BE/Premature terminal differentiation. To investigate the influence of fractionation on cell survival and radiation induced premature differentiation as markers for early and late effects after X-rays and carbon irradiation. Normal human fibroblasts NHDF, AG1522B and WI-38 were irradiated With 250 kV X-rays, or 266 MeV/u, 195 MeV/u and I I MeV/u carbon ions. Cytotoxicity was measured by a clonogenic survival assay or by determination of the differentiation pattern. Experiments with high-energy carbon ions show that fractionation induced repair effects are similar to photon irradiation. The RBE10 values for clonogenic survival are 1.3 and 1.6 for irradiation in one or two fractions for NHDF cells and around 1.2 for AG1522B cells regardless of the fractionation scheme. The RBE for a doubling of post mitotic fibroblasts (PMF) in the population is I for both single and two fractionated irradiation of NHDF cells. Using I I MeV/u carbon ions, no repair effect can be seen in WI-38 cells. The RBE10 for clonogenic survival is 3.2 for single irradiation and 4.9 for two fractionated irradiations. The RBE for a doubling of PMF is 3.1 and 5.0 for single and two fractionated irradiations, respectively. For both cell lines the effects of high-energy carbon ions representing the irradiation of the skin and the normal tissue in the entrance channel are similar to the effects of X-rays. The fractionation effects are maintained. For the lower energy, which is representative for the irradiation of the tumor region. RBE is enhanced for clonogenic survival as well as for premature terminal differentiation. Fractionation effects are not detectable. Consequently, the therapeutic ratio is significantly enhanced by fractionated irradiation with carbon ions.