Inhibition of chemiluminescent response of olive flounder Paralichthys olivaceus phagocytes by the scuticociliate parasite Uronema marinum

Experiments were conducted to evaluate the in vitro capacity of the scuticociliatian parasite Uronema marinum to inhibit chemiluminescence (CL) of olive flounder Paralichthys olivaceus phagocytes. Luminol-enhanced CL was used to measure the production of reactive oxygen intermediates (ROIs) generated by respiratory bursts of phagocytes using zymosan as a stimulant. Cytotoxic and antioxidative activities of excretory-secretory (ES) products of the parasite were evaluated as well. Live U. marinum and its ES products had a negative and dose-dependent effect on luminol-enhanced CL responses of zymosan-stimulated phagocytes of olive flounder. After CL assay, the number of phagocytes showing viability was significantly reduced in the cells incubated with live U. marinum at ratios of 2:1 and 1:1 phagocytes:ciliates or ES products with 0.3 mg protein ml(-1) compared to controls. Lysis of phagocytes by exposure to ES products was observed also. ES products from U. marinum showed considerably high activities of superoxide dismutase (SOD) and catalase. The results of this study suggest that U. marinum can protect itself against host's phagocytes mediated oxidative damage by destroying phagocytes and scavenging ROIs.     

Surface properties of Staphylococcus aureus affecting chemiluminescence response of human phagocytes

To assess the surface properties of Staphylococcus aureus affecting the response of human phagocytes, the effects of the organisms with different surface properties on the chemiluminescence (CL) response of human phagocytes were examined. The magnitude of the phagocytic CL response to hydrophobic strains was significantly greater than that to hydrophilic strains, while no significant difference in the CL response was seen between protein A-deficient strains and their parent strains. The CL response to the hydrophilic organisms prepared from a hydrophobic strain by trypsin treatment decreased significantly. These results suggest that the phagocytic CL response to staphylococci depends on the hydrophobicity of the surface, but not on the presence of protein A. Two protein A-deficient strains which were isolated from protein A-positive strains showed identical hydrophobicity with their parent strains. All of the hydrophilic strains isolated from hydrophobic strains possessed protein A identical to that of their parent strains. Moreover, a hydrophilic strain could be isolated from a protein A-deficient, hydrophobic strain. These results strongly suggest that protein A is not solely responsible for the surface hydrophobicity of S. aureus.     

Factors affecting the distribution of juvenile estuarine and inshore fish

The differential distributions of juveniles and adults of 25 species of teleost were investigated and compared from four habitat types in sub-tropical Moreton Bay, Queensland. The aim of the study was to identify factors influencing the distribution of juveniles, particularly the species which enter estuaries. The following habitats were sampled: a shallow, sheltered tidal estuary (Caboolture); a shallow, exposed bay with muddy substrates (Deception Bay); an exposed area of sandy substrates and seagrass (Toorbol Point) and a sheltered oceanic site with sandy substrates and seagrass (Kooringal). Data on diet, spawning seasons and recruitment periods of fry are presented together with measurements of salinity, temperature and turbidity. Species entering estuaries recruited mainly in summer (rainy season). The possible preference of juveniles for calm water, the roles of food and predation pressure, the effects of salinity, temperature and turbidity are discussed in relation to the biology and distribution of the fish. Salinity and temperature were probably not important to most juvenile fish. The effects of calm water, suitable food and predators vary according to species. Although all juveniles studied preferred shallow water, in the case of those entering estuaries, turbidity was the single most important factor. Juveniles of the same species occurred in both the estuary and Deception Bay where abiotic and biotic factors other than turbidity were different. During summer, turbidity gradients extended from east to west in Moreton Bay with highest turbidities in Caboolture estuary and Deception Bay. In winter, turbidities throughout Moreton Bay were low and relatively uniform. At this time many of the ‘clear water’ species occurred in Deception Bay. The influence of high turbidity on fish may be linked to reduced predation pressure and perhaps food supply in shallow water. Turbidity gradients in summer may aid fry in locating estuarine nursery grounds. It is apparent however, that juveniles of many species are probably not attracted to estuaries per se but to shallow turbid areas.     

Factors affecting fish diversity on a temperate reef

Synopsis Subtidal studies of fish stocks conducted along a rock breakwater in Southern California reveal a rich and diverse fauna with elements from cool and warm temperate regions. More than 100 species have been observed with half of these resident. Only a single large, permanently territorial species occurs on the reef though many small, often cryptic species defend home and/or reproductive sites. Many of the larger, mobile species orient to temperature stratification and a portion of the diversity can be allied to the ecotonal effect of stable stratification. Both large predators and herbivores are rare; the majority of the species are micropredators, grazing on sedentary or benthic microinvertebrates.Reproduction is keyed to spring-summer seasons, generally with pelagic eggs, embryos and larvae. The live-bearing resident embiotocids show the least fluctuation in numbers while many oviparous species have shown major changes in annual success during the study period. Although the success of individual species varies, the diversity and total abundance of fishes has remained relatively stable for the reef community as a whole. This stability cannot be considered to reflect an equilibrium community and in fact the structure of the community has changed significantly during the five year study.     

Factors affecting the efficiency of somatic cell nuclear transplantation in the fish embryo

Procedures to improve somatic cell nuclear transplantation in fish were evaluated. We reported effects of nonirradiated recipient eggs, inactivated recipient eggs, different combinations between recipient eggs and donor cells, duration of serum starvation, generation number, and passage number of donor cells on developmental rates of nuclear transplant (NT) embryos. Exposure to 25,000 R of gamma-rays inactivated recipient eggs. Single nucleus of cultured, synchronized somatic cell from gynogenetic bighead carp (Aristichthys nobilis) was transplanted into nonirradiated or genetically inactivated unfertilized egg of gibel carp (Carassius auratus gibelio). There was no significant difference in developmental rate between nonirradiated and inactivated recipient eggs (27.27% vs. 25.71%, respectively). Chromosome count showed that 70.59% of NT embryos contained 48 chromosomes. It showed that most NT embryos came from donor nuclei of bighead carp, which was supported by microsatellite analysis of NT embryos. But 23.53% of NT embryos contained more than 48 chromosomes. It was presumed that those superfluous chromosomes came from nonirradiated recipient eggs. Besides, 5.88% of NT embryos were chimeras. Eggs of blunt-snout bream (Megalobrama amblycephala) and gibel carp were better recipient eggs than those of loach (Misgurnus anguillicaudatus) (25% and 18.03% vs. 8.43%). Among different duration of serum starvation, developmental rate of NT embryos from somatic nuclei of three-day serum starvation was the highest, reaching 25.71% compared to 14.14% (control), 20% (five-day), and 21.95% (seven-day). Cultured donor cells of less passage facilitated reprogramming of NT embryos than those of more passage. Recloning might improve the developmental rate of NT embryos from the differentiated donor nuclei. Developmental rate of fourth generation was the highest (54.83%) and the lowest for first generation (14.14%) compared to second generation (38.96%) and third generation (53.01%).     

A new approach for analysis of chemiluminescent kinetics of activated phagocytes in blood

Luminol chemiluminescence (LCL) is a simple, sensitive and time-saving tool to elucidate the oxidative activity of polymorphonuclear leukocytes (PMNL). In this study, a new approach for analysing the LCL kinetics, recorded from stimulated PMNL, and for a more accurate elucidation of their functional state, is proposed. This approach is based on the proposal that the LCL kinetics of stimulated PMNL is a result of time-probabilistic nature of the processes, leading to light emission. On this basis the LCL response was described by the parameters of a Poisson-type distribution. Relationships between these parameters and some factors influencing LCL kinetics (number of PMNL and erythrocytes, temperature, stirring) were investigated. Their development in time was different. It was suggested, that the two phases of the model LCL response were connected with extracellular and intracellular LCL. The terms and the advantages of this approach for analysis of phagocyte oxidative capacity are discussed.     

The role of phagocytes in the protective mechanisms of fish

Phagocytes are cells principally dedicated to the recognition and elimination of invading organisms and damaged tissue. Those described in fish are the granulocytes (particularly neutrophils) and mononuclear phagocytes (tissue macrophages and circulating monocytes). Their movement to sites of microbial invasion is an early event in the inflammatory response and the role of host-derived factors as attractants, such as eicosanoids, is discussed. Opsonins mediate the recognition between phagocyte and particle, and receptors for serum complement component C3 and the Fc fragment of opsonic antibody have been described. Fundamental to the protection offered by the phagocytes is their bactericidal larvacidal activity, which is closely associated with the production of oxygen free radicals. Phagocytes as accessory cells are discussed, including their role in antigen presentation. A knowledge of the modulation of phagocyte function, with activation by various substances and suppression by others, is important if protective responses are to be achieved by up-regulating phagocyte activity.     

恶梦的影响因素研究

恶梦是与睡眠相关的常见心理现象.目前,恶梦的概念仍具有争议,但恶梦与心理健康的关系,已经引起了研究者广泛关注.恶梦的病因学研究表明,恶梦与遗传及生理因素有关;恶梦具有人格倾向性,应激与创伤因素是其产生的主要原因,与分裂症等精神疾病高度相关;恶梦与睡眠呼吸相关因素关系不是很明确;恶梦与多巴胺受体激动剂等药物显著相关,恶梦产生的其他因素研究尚待发现.然而这些因素与恶梦的因果关系并不确定,各因素之间的关系及作用机制有待进一步研究.未来的研究可以改进研究方法,扩大研究对象,进行纵向研究等.     

Ethanol inhibition of the chemiluminescent response of stimulated macrophages.

The effect of ethanol on the luminol-dependent chemiluminescence and cAMP level in mice peritoneal macrophages was investigated. Ethanol was shown to inhibit the chemiluminescence of macrophages by acting both as a "trap" for active radicals and as a suppressor of the cellular functional activity. A short preincubation of macrophages with ethanol results in a dose-dependent decrease of the chemiluminescent response to the stimulatory agent (opsonized zymosan). Ethanol was also shown to induce a peakwise rise of the intracellular cAMP after a 2-min incubation. The observed effects are correlated both in time and concentration, which allows the presumption that inhibition of the functional activity of macrophages is mediated by the increase of the intracellular cAMP level.     

Evolution of the inflammatory response in vertebrates: fish TNF-alpha is a powerful activator of endothelial cells but hardly activates phagocytes

TNF-alpha is conserved in all vertebrate classes and has been identified in all taxonomic groups of teleost fish. However, its biological activities and its role in infection are largely unknown. Using two complementary fish models, gilthead seabream and zebrafish, we report here that the main proinflammatory effects of fish TNF-alpha are mediated through the activation of endothelial cells. Thus, TNF-alpha promotes the expression of E-selectin and different CC and CXC chemokines in endothelial cells, thus explaining the recruitment and activation of phagocytes observed in vivo in both species. We also found that TLR ligands, and to some extent TNF-alpha, were able to increase the expression of MHC class II and CD83 in endothelial cells, which might suggest a role for fish endothelial cells and TNF-alpha in Ag presentation. Lastly, we found that TNF-alpha increases the susceptibility of the zebrafish to viral (spring viremia of carp virus) and bacterial (Streptococcus iniae) infections. Although the powerful actions of fish TNF-alpha on endothelial cells suggest that it might facilitate pathogen dissemination, it was found that TNF-alpha increased antiviral genes and, more importantly, had little effect on the viral load in early infection. In addition, the stimulation of ZF4 cells with TNF-alpha resulted in increased viral replication. Together, these results indicate that fish TNF-alpha displays different sorts of bioactivity to their mammalian counterparts and point to the complexity of the evolution that has taken place in the regulation of innate immunity by cytokines.     

Factors affecting response of groups of dairy cows managed for different calving-conception intervals

Factors which positively or adversely affect the response of cow groups to different planned conception periods were analyzed and quantified. Cows were randomly assigned to groups for breeding at postpartum intervals of 35 to 59, 60 to 90 and 120 to 150 days in a research herd, or 60 to 90 and 120 to 150 days in a cooperating commercial herd, with a planned preceding dry period of 60 days in both herds. Breeding at 35 to 59 and 60 to 90 days post partum resulted in a lower conception rate among multiparous cows but had no effect on primiparous cows. Genital disorders such as metritis, retained placenta, vulva inflammation and vaginitis, did not affect the start of luteal activity or length of the subsequent cycles, but caused a significant delay of the first behavioral estrus and, cosequently, a delay of the first insemination in the earlier breeding groups. About 30% of the cows in the different categories were inseminated three or more times and were considered to be repeat breeders. Response rates (number of cows conceiving on time/number assigned) in the later breeding group improved due to higher submission rates (number of cows submitted on time/number assigned), and the conception rates were higher (number of cows conceiving on time/number submitted). The rates in all groups were adversely affected by repeat breeding and genital disorders. The latter delayed the first insemination and the conception rate.     

Factors affecting the end-systolic pressure-volume relationship

The end-systolic pressure-volume relationship (ESPVR) defines the systolic limits of cardiac performance. Using an isolated cross-circulated canine heart preparation, we examined the influence of afterload impedance changes, changes in coronary artery pressure (CAP), and regional ischemia on the ESPVR. We found that afterload impedance did not change the slope of the ESPVR but that increases in resistance and characteristic impedance did shift the relation slightly to the left. There was no change in the ESPVR with changes in CAP above a certain critical value. A decrease in CAP below this value caused a progressive decline in the slope of the ESPVR. With regional ischemia the ESPVR became nonlinear, and there was a near parallel downward shift of the ESPVR in the high-volume range. This shift was directly proportional to the extent of ischemic area. We conclude that an adequate measurement of the ESPVR demands at least three pressure-volume points to check for linearity and characterization of both the slope and volume intercept.     

Factors affecting spermatogenesis in the stallion

Spermatogenesis is a process of division and differentiation by which spermatozoa are produced in seminiferous tubules. Seminiferous tubules are composed of somatic cells (myoid cells and Sertoli cells) and germ cells (spermatogonia, spermatocytes, and spermatids). Activities of these three germ cells divide spermatogenesis into spermatocytogenesis, meiosis, and spermiogenesis, respectively. Spermatocytogenesis involves mitotic cell division to increase the yield of spermatogenesis and to produce stem cells and primary spermatocytes. Meiosis involves duplication and exchange of genetic material and two cell divisions that reduce the chromosome number to haploid and yield four spermatids. Spermiogenesis is the differentiation without division of spherical spermatids into mature spermatids which are released from the luminal free surface as spermatozoa. The spermatogenic cycle (12.2 days in the horse) is superimposed on the three major divisions of spermatogenesis which takes 57 days. Spermatogenesis and germ cell degeneration can be quantified from numbers of germ cells in various steps of development throughout spermatogenesis, and quantitative measures are related to number of spermatozoa in the ejaculate. Germ cell degeneration occurs throughout spermatogenesis; however, the greatest seasonal impact on horses occurs during spermatocytogenesis. Daily spermatozoan production is related to the amount of germ cell degeneration, pubertal development, season of the year, and aging. Number of Sertoli cells and amount of smooth endoplasmic reticulum of Leydig cells and Leydig cell number are related to spermatozoan production. Seminiferous epithelium is sensitive to elevated temperature, dietary deficiencies, androgenic drugs (anabolic steroids), metals (cadmium and lead), x-ray exposure, dioxin, alcohol, and infectious diseases. However, these different factors may elicit the same temporary or permanent response in that degenerating germ cells become more common, multinucleate giant germ cells form by coalescence of spermatocytes or spermatids, the ratio of germ cells to Sertoli cells is reduced, and spermatozoan production is adversely affected. In short, spermatogenesis involves both mitotic and meiotic cell divisions and an unsurpassed example of cell differentiation in the production of the spermatozoon. Several extrinsic factors can influence spermatogenesis to cause a similar degenerative response of the seminiferous epithelium and reduce fertility of stallions.