bluuebunny/crossref_metadata_2025 huggingface dataset:
The humoral immune response of rainbow trout, Salmo gairdneri Richardson, and rabbits to Aeromonas salmonicida extracellular products
Authors: HASTINGS T. S. , ELLIS A. E.
Published: April 2006

Abstract. Controversy exists concerning the efficacy of vaccinating fish against furunculosis. Where success is claimed, there has been little attempt to characterize the protective antigens or confirm their immunogenicity. In this report, the immunogenicity of native extracellular products (ECP) of Aeromonas salmonicida and a formalin‐inactivated toxoid of ECP (f‐ECP) was studied in rainbow trout and rabbits, with particular attention to the putative bacterial virulence factors protease and haemolysin. Using crossed immunoelectrophoresis and Protein‐A absorption, antibodies to seven ECP components were detected in the rabbit following immunization with native ECP; antihaemolysin antibodies were found but antibodies to the protease could not be detected. Antibodies to at least 14 components of ECP, including haemotysin and protease, were detected in the rabbit following immunization with f‐ECP. In trout immunized either with native ECP or f‐ECP, antibodies to only four ECP antigens were detected and no antibodies to haemolysin or protease were found. The results may explain previous reports that passive immunization with rabbit antisera gave superior protection against furunculosis compared with antisera raised in fish, and indicate that many extracellular antigens of A. salmonicida may require modification in order to improve their immunogenicity in fish.
Emaciation of pond‐cultured snakehead, Channa striatus (Fowler)
Authors: NASH G. , ROBERTS R. J. , CHINABUT SUPRANEE , AREERAT SOFA , LIMSUWAN C.
Published: April 2006

Abstract. A new disease condition which may affect up to 20% of a population has been recognized in pond cultured snakeheads, Channa striatus (Fowler). Clinically, affected fish are inappetent and severely emaciated; histologically and ultrastructurally, emaciated pond reared snakeheads display extensive striated myofibrillar and sarcoplasmic degeneration and necrosis with inflammatory changes.
Immune protection in carp, Cyprinus carpio L., after immunization with Aeromonas hydrophila crude lipopolysaccharide
Authors: BABA T. , IMAMURA J. , IZAWA K. , IKEDA K.
Published: April 2006

Abstract. Vaccination with crude lipopolysaccharide (LPS) induced better protection against infection with Aeromonas hydrophila in carp than vaccination with formalin killed vaccine. Dipping fish in vaccine for 2 h at 25°C was more effective than intraperitoneal injection of the vaccine in procedural simplicity, lower stress loading and the degree of protection acquired. In carp immunized with crude LPS by the dip method, antibodies were not detected by bacteriai agglutination, passive haemagglutination and the agar diffusion tests. The results indicate that the protection against A. hydrophila infection in carp is not dependent on humoral immunity.
A novel assay to detect macrophage bactericidal activity in fish: factors influencing the killing of Aeromonas salmonicida
Authors: GRAHAM (nee CHUNG) S. , JEFFRIES A. H. , SECOMBES C. J.
Published: April 2006

Abstract. A novel assay to detect macrophage bactericidal activity is reported. It utilizes the reduction of a tetrazoiium dye, MTT, to colorimetrically detect the number of surviving bacteria after incubation with the macrophages. This assay has been optimized for the killing of Aeromonas salmonicida and its advantages over conventional colony counting are discussed. Using this assay, the authors have shown that normal macrophages are able to kill an A‐layer lacking strain of A. salmonicida (004) but not an A‐layer possessing strain (048). In contrast, macrophages activated in vivo were shown to be capable of killing both strains effectively.
Lesions associated with natural and experimental infections of Aeromonas hydrophila in channel catfish, Ictalurus punctatus (Rafinesque)
Authors: VENTURA M. T. , GRIZZLE J. M.
Published: April 2006

Abstract. Histologic differences were observed in channel catfish, Ictalurus punctatus (Rafinesque), with naturally occurring cutaneous (bacteria isolated only from lesions of skin and superficial muscle) and systemic Aeromonas hydrophila infections. Systemic infections were characterized by diffuse necrosis in several internal organs and the presence of melanin‐containing macrophages in the blood. Fish with only cutaneous infections had several types of concealed lesions including increased amounts of lipofuscin and haemosiderin in the liver and spleen; however, most visceral organs were not necrotic. The average condition factor of fish with cutaneous infections was lower than for fish with systemic infections. Early histologic lesions in channel catfish experimentally infected by immersion in a suspension of A. hydrophila were similar to lesions observed in naturally occurring systemic infections and to lesions previously reported in channel catfish injected intraperitoneally with A. hydrophila. In experimentally infected fish, all lesions healed in fish that did not die, and prolonged infections limited to skin and muscle did not occur.
Virulence of the aetiological agent of goldfish ulcer disease in Atlantic salmon, Salmo salar L.
Authors: CARSON J. , HANDLINGER J.
Published: April 2006

Abstract. An atypical strain of Aeromonas salmonicida was isolated from goldfish. Carassitis auraius L., with cutaneous ulcerativc lesions. Atlantic salmon, Salmo salar L., weighing 30–40 g were challenged parentcrally and by hath immersion with this strain. It was found to be highly virulent in both forms of challenge and was capable of achieving an LD50 of three colony‐forming units in parenterally challenged fish. The gross lesions and histopathology of infected fish bore a close resemblance to classical furunculosis in salmonids. Goldfish ulcer disease is endemic to some regions of Australia and represents a potential threat to the emerging salmonid farming industry.
Viral haemorrhagic septicaemia (VHS) in grayling, Thymallus thymallus L.
Authors: MEIER W. , WAHLI T.
Published: April 2006

Abstract. Two outbreaks of viral haemorrhagic septicaemia (VHS) have been detected in grayling, Thymallus thymallus L., in Switzerland, The affected fry showed a septicaemic haemorrhage. Due to their similar biotopes, the susceptibility of grayling and rainbow trout to the VHS virus has been compared. The mortality rates varied between 56 and 100% depending on the age of the fish and the infection dose, but no distinct loss‐associated difference occurred between grayling and rainbow trout when comparing the same age group and infection dose. Anaemia, scattered subcutaneous and intermuscular haemorrhages and enteritis were frequent macroscopic findings. The major histopathological changes included necrotic foci in the liver, spleen, intestinal mucosa and haematopoietic part of the kidney, whereas a severe tubulonephrosis was detectable in the urinary part of the kidney.
Further studies on Zschokkella russelli Tripathi (Myxozoa: Myxosporea) from Ciliata mustela L. (Teleostei; Gadidae), with emphasis on ultrastructural pathology and sporogenesis
Authors: DAVIES A. J. , SIENKOWSKI I. K.
Published: April 2006

Abstract In this second study of the myxozoan Zschokkella russelli Tripathi from Wales, infection occurred in 71‐0% of five‐bearded rocklings, Ciliata mustela L.; all infected fish were mature and immature fish were uninfected. Histologieal studies showed ehanges to gallbladder and liver that mostly conformed with earher findings, but sinusoidal dilation, which had not been seen previously, was present in three of 22 infected livers. Thickening around hepatic ducts was shown by transmission electron microscopy (TEM) to comprise fibroblasts and associated collagen bundles, while the attenuated epithelium of hepatic ducts bore few mierovilli. Zschokkella russelli plasmodia were seen by TEM to have fine tubular structures, particularly adjacent to developing sporonts. Spores showed long extensions to the sporoplasm, while spore valves had up to 18 surface ridges each and depressions between ridges were supported by microtubules. Otherwise, in its general ultrastructure and sporogenesis Z. russelli resembled other myxosporida.
An investigation into oxytetracycline residues in Atlantic salmon, Salmo salar L.
Authors: BRUNO D. W.
Published: April 2006

Abstract. An outbreak of clinical furunculosis in commercially reared Atlantic salmon, Salmo salar L., broodfish in fresh water was successfully treated with a single intraperitoneal injection of oxytetracycline. The mean serum oxytetracycline residue in these fully mature fish did not decline and, at 8 weeks post‐injection, was 3·7 μg/ml. In contrast, the mean serum residues in other fully mature but healthy fish declined during an 8‐week experimental period to 1·3 μg/ml. The mean concentration of oxytetracycline in the liver of healthy mature fish was approximately two‐fold that of similar aged but non‐mature fish, and approximately four‐fold the concentration found in post‐smolts. Oxytetracycline residues 8 weeks after injection exceeded the minimum inhibitory concentration required for oxytetracycline sensitive Aeromonas salmonicida isolates in all groups, therefore under these circumstances, this antibiotic may be effective at a lower dose than that currently recommended. The histology of the liver from the furunculosis‐surviving broodfish showed an increase in tissue lesions when compared with the other mature and non‐mature fish in fresh water. The combination of prior infection and the physiological status of fasting broodfish may have influenced the rate at which this antibiotic is removed, and, in cases where these residues persist, there may be further damage to the liver.
Mycotic dermatitis in a freshwater gizzard shad, the bony bream, Nematalosa erebi (Günther), in the River Murray, South Australia
Authors: PUCKRIDGE J. T. , WALKER K. F. , LANGDON J. S. , DALEY C. , BEAKES G. W.
Published: April 2006

Abstract. The lower Murray population of bony bream is subject to an annual epidemic of the oomycete Saprolegnia (principally S. parasitica) and the bacterium Aeromonas hydrophila. The epidemic is species‐specific; it mainly affects adults whose susceptibility may be increased by stress due to winter cold. Lesions occur on the mid‐flank and are characterized by an external mycelium, epidermal erosion, scale loss, hypodermal and muscular oedema, haemorrhage, myofibril degeneration and by the presence of Saprolegnia hyphae at all stages of infection. Although A. hydrophila is common in advanced lesions there is no significant systemic bacterial infection. This appears to be a primary mycotic dermatitis and is noteworthy because Saprolegnia is best‐known as a secondary pathogen.
Proteases secreted by strains ofAeromonas salmonicida
Authors: PRICE N. C. , STEVENS L. , DUNCAN D. , SNODGRASS M.
Published: April 2006

Abstract.The proteases secreted by four strains (MT004, 1102, 480 and 480P‐) ofAeromonas salmonicidagrown in liquid culture have been studied. Strains MT004, 1102 and 480 all show a similar pattern with two types of proteases produced; one of molecular weight 70 000 which is active against casein and gelatin and one (or more) of lower molecular weight (about 20 000) which is (are) active against gelatin but not casein. Strain 480P‐produces only the latter type of protease(s). The protease of molecular weight 70 000 is classified as a serine‐type protease, but further characterization of the features of its active site has not yet proved possible. The results are discussed in terms of the previously published but often contradictory data on the proteases ofA. salmonicida.
Efficacy studies of passive immunization against Aeromonas salmonicida infection in brook trout, Salvelinus fontinalis (Mitchill)
Authors: MARQUIS H. , LALLIER R.
Published: April 2006

Abstract. Aeromonas salmonicida, the aetiologic agent of furunculosis, causes high mortality in cultured salmonids. Experiments were conducted to determine the therapeutic and prophylactic efficacy of passive immunization against furunculosis in brook trout, Salvelinus fontinalis (Mitchill), infected by immersion. Rabbit hyperimmune serum was produced against a virulent strain of A. salmonicida and an aliquot of this serum was absorbed with cells of a non‐virulent strain of A. salmonicida. Immunoglobulins from aliquots of the absorbed and non‐absorbed serum were purified using affinity chromatography. Each serum or immunoglobulin preparation was tested in passive immunization experiments. Brook trout were infected by immersion in a suspension of virulent A. salmonicida, and passively immunized by intraperitoneal injection at the time of experimental infection, or at various periods after experimental infection. Passive immunization of brook trout against furunculosis was therapeutically efficacious when effected either at zero, 24 or 48h post‐infection, but not at 72 or 96h. Purified rabbit immunoglobulins specific to virulent A. salmonicida were as protective as the initial rabbit hyperimmune serum in protecting brook trout against furunculosis. To determine the prophylactic efficacy of this treatment, the groups of fish passively immunized at the time of the experimental infection were challenged a second time at either 14, 35, 41 or 56 days after passive immunization. Brook trout were protected against a second experimental bath challenge with virulent A. salmonicida for a period of 35–41 days.
Urine properties in carp, Cyprinus carpio L., with sekoke disease
Authors: KAKUTA I. , NAMBA K.
Published: April 2006

Abstract. Changes in the properties of urine and blood of carp with sekoke disease were studied. With the progress of this disease, the parameters of blood and particularly urine changed significantly. After 120 days, urine flow, osmolarity and concentrations of inorganic ions (K+, Ca2+, Mg2+, Cl−) and organic compounds (ammonium, creatine and creatinine, protein, glucose) in the experimental group showed higher values than those of the controls. Even after 60 days, when clinical signs of sekoke disease were not evident, abnormally high concentrations of ammonium, protein and glucose in the urine were found in the experimental group.
Peculiar cases of intracardiac parasitism in the pilchard, Sardina pilchardus (Walbaum), by a pennellid copepod belonging to the genus Lernaeenicus
Authors: ROUSSET V. , RAIBAUT A.
Published: April 2006

Abstract. The pilchard, Sardina pilchardus (Walbaum), is parasitized in coastal waters in the Languedoc‐Roussillon region (South of France) by a copepod species which belongs to the genus Lernaeenicus (Siphonostomatoida, Pennellidae). These mesoparasites become established in various parts of the body of the host (eye, lateral muscle or muscle at the bases of fins). Examination of specimens which had penetrated at the root of pectoral fins revealed that some had penetrated the heart. A curious case of transcardiac parasitism was observed. Host tissue reactions caused by the presence of parasites are described.
The bacterial flora of rainbow trout, Salmo gairdneri Richardson, and brown trout, Salmo trutta L., eggs and its relationship to developmental success
Authors: BARKER G. A. , SMITH S. N. , BROMAGE N. R.
Published: April 2006

Abstract. The bacterial flora of rainbow, Salmo gairdneri Richardson, and brown trout, Salmo trutta L., eggs was studied during incubation. Few bacteria were considered to exist internally, although Pseudomonas species and Aeromonas hydrophila were isolated. During incubation, large numbers of bacteria approaching 500 colony forming units/mm2 accumulated around egg surfaces. Both rainbow and brown trout eggs placed in a through‐flow system were colonized mainly by Pseudomonas sp. and A. hydrophila, whilst rainbow trout eggs in a separate recycling system were dominated by a Cytophaga species. Glass beads were also incubated (as an inert surface) and found to support significantly lower numbers of bacteria. Egg mortalities were recorded daily and found to differ significantly between both fish species and water conditions. Statistical analysis indicated a potentially significant correlation between hatching success and numbers of surface bacteria.
Ulcerative skin and fin lesions in reared turbot, Scophthalmus maximus (L.)
Authors: DEVESA S. , BARJA J. L. , TORANZO A. E.
Published: April 2006

Abstract. In this report, the authors describe the evolution of an ulcerative disease that occurred during July and August 1986 in cultured juvenile turbot, Scophthalmus maximus (L.), in northwestern Spain. The daily fish mortality ranged from less than 1 to 7·5%, and the total of cumulative losses were 23·2%. The start of the epizootic was closely associated with a sudden increase of water temperature to values higher than 20·C. Peaks of mortality were observed during the development of the disease. Affected turbot showed erratic swimming, respiratory distress and inappetence. The lesions began as white discoloured foci on the skin, operculum, and base of dorsal and caudal fins which could suffer a total destruction of the interradial membrane. In an advanced stage of this condition, the epithelial surface of the centre of the lesions sloughed off and shallow and haemorrhagic ulcers were produced. Three distinct areas were observed in the ulcerative lesions with a clear predominance of different microorganisms: (1) a peripheric pale zone invaded by a ciliate protozoan resembling Cryptocaryon spp.; (2) an intermediate greyish‐dark area containing large numbers of fastidious myxobacteria which failed to grow in culture media; and (3) a central haemorrhagic zone where we have isolated two halophilic, urease positive Vibrio strains (closely related to V. carchariae). No microbial involvement was detected in the internal organs of affected fish. The virulence assays conducted with the Vibrio strains failed to reproduce the signs of the disease, either by intraperitoneal inoculation or by water challenge after skin abrasion. The use of alternate baths of formalin/malachite green and nitrofurazone resulted in an effective therapy to control the mortalities.
Immunoglobulin heterogeneity in the rainbow trout, Salmo gairdneri Richardson
Authors: SANCHEZ C. , DOMINGUEZ J. , COLL J.
Published: April 2006

Abstract. Hetereogeneity of rainbow trout immunoglobulins was demonstrated by using monoclonal antibody 1A6 and polyacrylamide‐gradient gel electrophoresis. Immunoglobulins defined by elisa using monoclonal antibody 1A6 were about 30% of the total immunoglobulins, detected by elisa using polyclonal antibodies, in healthy rainbow trout. In trout obtained from farms with a previous history of infectious viral diseases, 1A6‐immunoglobulins were only about 14% of the total. Several serum pools from infected trout could be totally depleted of 1A6‐immunoglobulins (about 12% of total immunoglobulins) by affinity chromatography over Sepharose immobilized monoclonal antibody 1A6. Polyacrylamide‐gradient gel electrophoresis under denaturing conditions of total immunoglobulins, 1A6 immunoglobulins and no‐1A6 immunoglobulins purified by affinity chromatography, showed a majority heavy chain of 70 KDa and a minority heavy chain of about 60 KDa, two light chains of 24 and 26 KDa, and a 11–14 KDa polypeptide.
Pathology of red spot disease in sea mullet, Mugil cephalus L., from eastern Australia
Authors: CALLINAN R. B. , FRASER G. C. , VIRGONA J. L.
Published: April 2006

Abstract. Lesions present on sea mullet, Mugil cephalus L., during the first 3 weeks of red spot disease outbreaks are described. Necrotizing dermatitis is a severe, locally extensive, granulomatous lesion associated with invasion of dermis and underlying skeletal muscle by numerous, non‐septate, fungal hyphae 12–18 μm in diameter. Erythematous dermatitis is a mild to severe, focal, chronic active dermatitis without fungal involvement. Lesions intermediate between these two forms, with small to moderate numbers of fungal hyphae in dermis and skeletal muscle also occur. Findings indicate that erythematous dermatitis lesions and intermediate‐type lesions subsequently resolve, while necrotizing dermatitis lesions consistently develop into dermal ulcers, with associated severe necrotizing granulomatous myositis. Generally, dermal ulcers occur significantly more often on posterior and dorsal areas of the body surface than on anterior and ventral areas. Lesions heal by combinations of epidermal and dermal repair, fibroplasia, destruction of fungi, removal of necrotic skeletal muscle and regeneration of myofibres. Atrophy of exocrine pancreas occurs in both diseased and clinically normal fish, but is generally more severe in diseased fish. The possible roles of suspected disease determinants, including falls in dissolved oxygen concentrations to sub‐lethal levels prior to red spot disease outbreaks, are discussed.
A new species of Goussia (Apicomplexa, Coccidia) in the kidney tubules of the cod, Gadus morhua L.
Authors: MORRISON C. M. , POYNTON S. L.
Published: April 2006

Abstract. Segments of the kidney tubules of about 16% of cod caught in the approaches to Halifax Harbour were found to contain a coccidian parasite. Macrogametes developed in an epicellular position, and microgamonts, unsporulated and sporulating oocysts, and free sporocysts, were found in the lumen of the kidney tubule. The epithelial cells of the kidney tubules were damaged and granulomas often formed around infected tubules. The presence of a suture dividing the sporocyst wall into two valves could only be determined using electron microscopy. Other coccidians which have been placed in the genus Eimeria because sutures could not be seen using light microscopy, although no Stieda body was present, may also belong to the genus Goussia. No other coccidians have been reported in the kidney tubules of marine fish, and the name Goussia spraguei sp. nov., is proposed.
Chromatoblastomas and related pigmented lesions in deepwater redfish, Sebastes mentella (Travin), from North Atlantic areas, especially the Irminger Sea
Authors: BOGOVSKI S. P. , BAKAI Y. I.
Published: April 2006

Abstract This study involved 34 960 specimens of deepwater redfish, Sebastes mentella (Travin), from the North Atlantic, 21 460 of them from the Irminger Sea. One hundred and three specimens of this species, 96 with pigmented lesions, were examined histologically. The black patches on the redfish skin proved to be superficial melanosis (48 cases) and deep melanosis (24 cases). Skin pterinophorosis was noted in 20 cases. Pigment tissue neoplasms were observed in 26 fish; all were benign chromatoblastomas. Fourteen tumours were diagnosed as melanomas originating from melanophores, seven as pterinophoromas originating from pterinophores, and five as pterino‐melanophoromas or melano‐pterinophoromas of mixed origin of both chromatophore types. The tumours on the trunk of redfish occurred only in pigmented areas larger than 20 cm2. Fish with such areas constitute no more than 2.4% of the total Irminger Sea redfish population. Most (76.2%) of pigmented lesions in this redfish population did not exceed 5 cm2 in area. The arrangement of pigmented areas differed in males and females. In females, 97% of patches were found between the pectoral and the first dorsal fins, whilst in males, 84% of patches were situated on the head and caudal fin. Pigmented lesions occurred 2–5 times more often in females than males. The causes of pigment tissue neoplasms and pigmented lesions in deepwater redfish are unknown.
Autoagglutination, growth on tryptone‐soy‐Coomassieagar, outer membrane protein patterns and virulence of Aeromonas salmonicida strains
Authors: BERNOTH E.‐M.
Published: April 2006

Abstract. Twelve Aeromonas salmonicida isolates were examined for autoagglutination, colony colour on tryptone soy agar supplemented with Coomassie brilliant blue (TSA‐C), and outer membrane protein pattern by sodium dodecyl sulphate‐polyacrylamide gel electrophoresis (SDS‐PAGE). Autoagglutination did not correlate with colony colour on TSA‐C, nor with the presence of the additional 49‐kDa protein (A‐protein) in all strains tested. However, there was a correlation between colour on TSA‐C and A‐protein. Two weakly autoagglutinating isolates with no A‐protein detectable in SDS‐PAGE and with negative staining behaviour on TSA‐C shared another additional protein, designated X‐protein. One of these isolates was virulent for juvenile rainbow trout, the other one avirulent. Thus, for the strains examined, neither autoagglutination nor X‐protein were reliable indicators of virulence, and absence of A‐protein did not necessarily mean avirulence.
Immunohistological localization of trypsin in mucus‐secreting cell layers of Atlantic salmon, Salmo salar L.
Authors: BRAUN R. , ARNESEN J. A. , RINNE A. , HJELMELAND K.
Published: April 2006

Abstract. Immunohistochcmical examination showed that trypsin was present in mucus‐secreting cell layers of Atlantic salmon, such as surface epithelial cells of gills and intestine, and epidermal cells of dorsal skin. Trypsin in tissue slices was identified by an immunohisto‐chemical technique which used affinity purified immunoglobulins from rabbit antisera against purified salmon pancreatic trypsin as primary antibodies. Most of the positively stained cells appeared to be granulated and secretory. The authors hypothesize that trypsin in mucus‐secreting cell layers is a part of the non‐specific immune defence of the fish.
Immunosuppression in juvenile carp, Cyprinus carpio L.: the effects of the corticosteroids triamcinolone acetonide and hydrocortisone 21‐hemisuccinate (cortisol) on acquired immunity and the humoral antibody response to Ichthyophthirius multifiliis Fouquet
Authors: HOUGHTON G. , MATTHEWS R. A.
Published: April 2006

Abstract. Juvenile carp, Cyprinus carpio L., were immunized against Ichthyophthirius multifiliis following controlled exposure to the infective theront stage. On challenge, with a potentially lethal dose of theronts, all immunized fish survived, in contrast to 100% mortality in non‐immunized fish. Fourteen days following exposure to the challenge infection, immune and non‐immune fish were injected intraperitoneally with either triamcinolone acetonide or hydrocortisone 21‐hemisuccinate (cortisol) at doses of 100 μg or 10 μg/g body weight. Controls, including immunized and non‐immunized fish, were injected with saline or left untreated. Six days following corticosteroid administration, fish were exposed to challenge infections of I multifiliis. All fish treated with corticosteroid developed heavy infections with up to 100% mortality. Repeat experiments gave comparable results. Serum antibody levels recorded in similarly treated fish at intervals of 12 h and/or 1 week following corticosteroid administration were found to be relatively unaffected. The results are discussed in relation to the immune response to I multifiliis.
Effects of oral vaccination against vibriosis in turbot, Scophthalmus maximus (L.), and sea bass, Dicentrarchus labrax (L.)
Authors: DEC C. , ANGELIDIS P. , LAURENCIN F. BAUDIN
Published: April 2006

Abstract. Turbot, Scophthalmus maximus (L.), and sea bass, Dicentrarchus labrax (L.), are susceptible to vibriosis, a septicaemia caused in France by Vibrio anguillarum 408. A bacterin produced with this strain by Rhône–Merieux has been tested orally in both species and, as a comparison, by intraperitoneal injection. During a challenge carried out 4 weeks later by intraperitoneal inoculation, the protection observed in orally vaccinated fishes was significant (72 % in sea bass and 70 % in turbot). Eleven weeks after vaccination, this protection is still significant. The mean titre of serum agglutinins was weakly increased in orally vaccinated fishes. Bacteriostatic antibodies have also been searched for in serum, but compared to agglutination, the applied technique leads to lower titres and it has not been possible to prove the presence of such antibodies after oral vaccination. Passive immunizations using serum from orally vaccinated fishes (2 months after vaccination) confers some protection against a challenge carried out by inoculation of virulent vibrio. Therefore, the production of serum factors following oral vaccination of sea bass and turbot may be involved in generalized protection of fish.
The effects of trichlorfon, praziquantel and copper sulphate on various stages of the monogenean Benedeniella posterocolpa, a skin parasite of the cownose ray, Rhinoptera bonasus (Mitchill)
Authors: THONEY D. A.
Published: April 2006

Abstract. Monogeneans of the superfamily Capsaloidea have been a severe problem in maintaining both teleosts and elasmobranchs in captivity. Infestations of Benedeniella posterocolpa on the skin of the cownose ray, Rhinoptera bonasus, provided an excellent model for testing the effects of trichlorfon (0‐7ppm), praziquantel (20ppm) and copper sulphate (0‐25 ppm) on adult monogeneans in situ, and on adult monogeneans, oncomiracidia and eggs in vitro. One treatment with praziquantel eliminated 100% of the worms from the skin of rays. Two treatments with trichlorfon only eliminated 81% of the worms. Praziquantel killed all worms tested in vitro within 6h and prevented egg deposition. Trichlorfon killed all worms within 21 h, but some eggs were deposited. Copper sulphate had little effect on worms in vitro. Both trichlorfon and praziquantcl immobilized oncomiracidia while copper sulphate had little effect. Eggs were relatively resistant to these chemicals; however, trichlorfon and praziquantel were the most effective in killing eggs.
Immunization of channel catfish, Ictalurus punctatus Rafinesque, against Ichthyophthirius multifiliis (Fouquet): killed versus live vaccines
Authors: BURKART M. A. , CLARK T. G. , DICKERSON H. W.
Published: April 2006

Abstract. Fish surviving infection with the pathogenic ciliated protozoan, Ichthyophthirius multifiliis (Fouquet, 1876), become resistant to subsequent infection by the parasite. The acquired immunity suggests that development of a vaccine against the parasite may be possible. Because of the advantages of immunoprophylaxis for treatment of the disease, an effort has been made to determine whether fish exposed to killed parasite preparations can resist subsequent lethal challenge. Both the route of administration and the effects of stage specific antigens have been examined. Channel catfish vaccinated by intraperitoneal (i.p.) injection or bath immersion with killed I multifiliis tomites show 100% mortality following a standard challenge protocol. Similarly, 100% mortality was observed in test groups injected with tomite cilia. In both cases, a consistent difference in days to death between control and test group animals was observed. Although complete mortality was seen with fish injected with tomite preparations, fish vaccinated with killed trophonts (the feeding stage of the parasite) had a much greater degree of protection with approximately 50% of fish surviving an otherwise lethal challenge. Finally, animals injected intraperitoneally with live tomites showed nearly complete immunity and were identical in their response to fish which survive natural infection. The response of fish vaccinated with live parasites indicates that animals injected intraperitoneally can develop surface immunity and that i.p. injection is a suitable route of administration for potential I. multifiliis vaccines.
In vivo and in vitro cell‐mediated immune responses of rainbow trout, Oncorhynchus mykiss (Walbaum), against Cryptobia salmositica Katz, 1951 (Sarcomastigophora: Kinetoplastida)
Authors: THOMAS P. T. , WOO P. T. K.
Published: April 2006

Abstract. Delayed‐type hypersensitivity (DTH) reaction (an in vivo manifestation of cell‐mediated immunity) was detected in Oncorhynchus mykiss maintained on a pantothenic‐acid‐supplemented diet 2 weeks after infection with Cryptobia salmositica. The reaction was similar to that in mammals with mononuclear cell infiltration into the dermis and muscle layers and the presence of oedema. DTH reaction was also displayed by fish on a pantothcnic‐acid‐supplemented diet that had recovered from the infection and were protected against further infection. The reaction was less marked in infected or protected fish on a pantothenie‐acid‐deficient diet. Inhibition of macrophage migration (an in vitro expression of cell‐mediated immunity) was observed when head kidney cell suspensions from protected fish maintained on either pantothenic acid supplemented or deficient diets were incubated with Cryptobia antigen. No inhibition of migration was evident when head kidney cell suspensions from the above fish were incubated without antigen, nor was it evident when cells from uninfected fish were used. The occurrence of a typical DTH reaction in rainbow trout and the feasibility of assessing it by measuring the thickness of the induration provides a simple and practical method for assessing cell‐mediated immunity in large scale vaccination programmes against pathogens.
The secretion of amylase, phospholipase and protease from Aeromonas salmonicida, and the correlation with membrane‐associated ribosomes
Authors: CAMPBELL C. M. , DUNCAN D. , PRICE N. C. , STEVENS L.
Published: April 2006

Abstract. The following extracellular enzymes have been readily detected in the culture filtrates from Aeromonas salmonicida: amylase, phospholipase, lysophospholipase and ribonuclease. Amylase and phospholipase have been partially characterized. Evidence suggests that glycogen may be the natural substrate for amylase, and that the role of the enzyme in natural infection is to digest glycogen present in fish muscle. The secretion of amylase activity is suppressed by the addition of glucose to the growth medium. The amounts of amylase, phospholipase and protease that can be detected in culture filtrates decreases with increase in the growth temperature from 25 to 32°C. This marked decrease in secretion of hydrolytic enzymes occurs although the initial growth rates at 25 and 32°C are similar. Free and membrane associated ribosomes have been isolated from cultures grown at 25 and 32°C. At 32°C there is a smaller proportion of membrane‐associated ribosomes and this is consistent with the hypothesis that extracellular enzymes from Aeromonas salmonicida are secreted on membrane‐bound polysomes.
Regression effect of carp, Cyprinus carpio L., peripheral blood lymphocytes on CHV‐induced carp papilloma
Authors: MORITA N. , SANO T.
Published: April 2006

Abstract. The effect of peripheral blood lymphocytes (PBL) of carp, Cyprinus carpio L., was investigated on the regression of papilloma which had been induced in carp experimentally infected with Herpesvirus cyprini (CHV). The regression of the papilloma was delayed in carp injected with anti‐carp PBL serum. In addition, the spontaneous cytotoxic activity of PBL derived from normal carp was suppressed by injection with anti‐carp PBL serum. These results suggest that the spontaneous cytotoxic activity of carp PBL plays an important role in the regression of carp papilloma.
Concentration and detection of Aeromonas salmonicida from hatchery water
Authors: MAHESHKUMAR S. , GOYAL S. M. , ECONOMON P. P.
Published: April 2006

Abstract. A method using 1‐MDS electropositive filters for the concentration of Aeromonas salmonicida from hatchery water was developed. The procedure consisted of passing hatchery water at ambient pH through the filters followed by the elution of the adsorbed bacteria in a small volume of 3% beef extract solution (pH 10.0). A 300‐fold reduction in volume of hatchery water and an average recovery of 35% of the seeded bacteria was achieved.
Cross‐protection after immunization of Atlantic salmon, Salmo salar L., against different strains of Vibrio salmonicida
Authors: LILLEHAUG A. , SØRUM R. H. , RAMSTAD A.
Published: April 2006

Abstract. Atlantic salmon were immunized with one or other of two bacterins made from different strains of Vibrio salmonicida. The two strains differed both in geographic origin and plasmid profile. One of the strains had given rise to disease outbreaks in salmon and also in cod which were kept in net‐pens. However, by using a virulent challenge, it appeared that salmon, immunized with any of the two strains, were also protected against infection with the other. This result indicates that the two strains are serologically similar.
Microsporidiosis due to a pleistophorid in marron, Cherax tenuimanus (Smith), (Decapoda: Parastacidae)
Authors: LANGDON J. S.
Published: April 2006

Abstract. Microsporidiosis in the freshwater crayfish Cherax tenuimanus (Smith), or marron, was found to be due to a pleistophorid characterized by a single sporulation sequence producing eight, 16, 32 or 64 monomorphometric spores in a sporophorous vesicle with a fine two‐layered wall. Infection occurred predominantly in locomotor, cardiac and gastrointestinal striated muscle. The disease ranged from subclinical infections where haemocytic encapsulation and infiltration of the spore masses controlled its progress, to fulminant disease with multifocal infection in the absence of effective haemocytic responses. The lethal lesions in the latter cases appeared to be those in the proventriculus. Prevalence of infection and incidence of mortality were low. The same microsporidian was found in subclinically infected C. quinquecarinatus (Gray) and C. quadricarinatus (von Mortens).
Antibody specificities in Atlantic salmon, Salmo salar L., against the fish pathogens Vibrio salmonicida and Vibrio anguillarum
Authors: BøGWALD J. , STENSVAG K. , HOFFMAN J. , JØRGENSEN T.
Published: April 2006

Abstract. Specificities of polyclonal salmon antisera made against the fish pathogens Vibrio salmonicida and Vibrio anguillarum were studied. Using ELISA and Western blot techniques, antisera made against V. salmonicida or V. anguillarum serovar 1 demonstrated high responses against the homologous bacterium or its isolated LPS. In contrast, antisera obtained after immunization with V. anguillarum serovar 2 displayed low antibody titres against homologous antigens. Elcctrophoretic transfer of SDS‐PAGE separated V. salmonicida LPS antigen to nitrocellulose strips and subsequent immunostaining with salmon antisera revealed a strong reaction exclusively in the low molecular weight region (<14kD). On the other hand, immunoblots of V. anguillarum LPS preparations using salmon immunesera raised against this species showed a heterogenous staining pattern ranging from high to medium LPS‐size. In addition, most of the salmon antisera made against V. anguillarum serovar 2 also reacted with a low molecular weight LPS antigen band.
The relationship between the neighbourhood environment and adverse birth outcomes
Authors: Farley Thomas A. , Mason Karen , Rice Janet , Habel Joanna D. , Scribner Richard , Cohen Deborah A.
Published: April 2006

Intrauterine growth retardation and preterm birth are more frequent in African‐American women and women of lower socio‐economic status, but the reasons for these disparities are not fully understood. The physical and social environments in which these women live may contribute to these disparities. We conducted a multilevel study to explore whether conditions of mothers’ neighbourhood of residence contribute to adverse birth outcomes independent of individual‐level determinants. We analysed data from 105 111 births in 1015 census tracts in Louisiana during 1997–98, merging it with data from other existing sources on neighbourhood socio‐economic status, neighbourhood physical deterioration, and neighbourhood density of retail outlets selling tobacco, alcohol and foods.

After controlling for individual‐level sociodemographic factors, tract‐level median household income was positively associated with both birthweight‐for‐gestational‐age and gestational age at birth. Neighbourhood physical deterioration was associated with these birth outcomes in ecological analyses but only inconsistently associated with them after controlling for individual‐level factors. Neither gestational age nor birthweight‐for‐gestational‐age was associated with the neighbourhood density of alcohol outlets, tobacco outlets, fast‐food restaurants or grocery supermarkets. We conclude that measures of neighbourhood economic conditions are associated with both fetal growth and the length of gestation independent of individual‐level factors, but that readily available measures of neighbourhood retail outlets are not. Additional studies are needed to better understand the nature of environmental influences on birth outcomes.
The Undergraduate‐Postgraduate Interface
Authors: Vrotsos IA
Published: April 2006

The goal of dental education, since the mid‐19th century when the first Dental Schools appeared in Europe and America, has been to produce dentists able to carry out established dental therapies and serve the needs of patients. The range of content of Dental Education has been changing radically every 20–30 years, but especially in the last half of the 20th century, the need for constant reassessment, modification and amendment of dental curricula became apparent.

Hence, after the 1950s it became clear that dental curricula were not able to provide the breadth of knowledge and clinical expertise that had accumulated in certain areas in dentistry, such as oral surgery and orthodontics. This resulted in the appreciation of the need for organising and establishing university or non‐university courses which would provide dentists with the additional specialised knowledge within a timeframe of two and later three years.

This marked the birth of postgraduate programmes. Fifty years later, and based on the experience that has accumulated mainly from the ‘dentally developed’ countries in Western Europe and USA we can say that the ‘philosophy’ of dental postgraduate education remains largely the same. In other words, the main aim of postgraduate programmes remains to provide knowledge and practical skills in specialised areas of dentistry with the purpose of creating (i) clinical practitioners specialised in specific areas (specialisation, specialty) and (ii) general dentists with a strong scientific background, able to provide original research in basic sciences and with the necessary training and experience in organising and delivering dental education.

As a general rule, postgraduate education is not antagonistic to undergraduate education, but on the contrary, it represents an extension of the knowledge acquired in undergraduate education into specific areas of interest and in certain directions. It is generally accepted that advanced postgraduate education can be successfully accomplished only on the basis of a complete, well‐organised undergraduate education. In the absence of this basis, the effectiveness of postgraduate programmes in succeeding in their goals can only be limited. This has been proved many times, at least in the USA, during the final evaluation (final performance) of postgraduate students coming from ‘dentally developed’ countries, in comparison with students having a low level of undergraduate education. Hence at the beginning of the 21st century, we can affirm that the efforts for good administration, high curriculum level and clear goals of postgraduate studies must be based on a well‐structured, well‐functioning and productive undergraduate dental education systems.
Graduate Programmes for Clinical Disciplines
Authors: Athanasiou A
Published: April 2006

The aim of this presentation was to provide a stimulus for discussion regarding graduate programmes for clinical disciplines because many countries and organisations are in the process of establishing, improving or harmonising their standards concerning these educational activities. Various aspects of graduate programmes for clinical disciplines were discussed including curricula, degrees/diplomas, structure of clinical education, teacher/student interaction models, research activities and assessment criteria/methods. The presentation gave emphasis to the European experience, but similarities and differences in comparison to the US models were also discussed.
Impact of alternate definitions of fever resolution on the composite endpoint in clinical trials of empirical antifungal therapy for neutropenic patients with persistent fever: analysis of results from the Caspofungin Empirical Therapy Study
Authors: De Pauw B.E. , Sable C.A. , Walsh T.J. , Lupinacci R.J. , Bourque M.R. , Wise B.A. , Nguyen B.‐Y. , DiNubile M.J. , Teppler H.
Published: April 2006

Abstract: Background. Sensitivity analyses were incorporated in a Phase III study of caspofungin vs. liposomal amphotericin B as empirical antifungal therapy for febrile neutropenic patients to determine the impact of varying definitions of fever resolution on response rates.

Methods. The primary analysis used a 5‐part composite endpoint: resolution of any baseline invasive fungal infection, no breakthrough invasive fungal infection, survival, no premature discontinuation of study drug, and fever resolution for 48 h during the period of neutropenia. Pre‐specified analyses used 3 other definitions for fever resolution: afebrile for 24 h during the period of neutropenia, afebrile at 7 days post therapy, and eliminating fever resolution altogether from the composite endpoint. Patients were stratified on entry by use of antifungal prophylaxis and risk of infection. Allogeneic hematopoietic stem cell transplants or relapsed acute leukemia defined high‐risk patients.

Results. In the primary analysis, 41% of patients in each treatment group met the fever‐resolution criteria. Low‐risk patients had shorter durations of neutropenia but failed fever‐resolution criteria more often than high‐risk patients. In each exploratory analysis, response rates increased in both treatment groups compared to the primary analysis, particularly in low‐risk patients.

Conclusions. Response rates for the primary composite endpoint for both treatment groups in this study were driven by low rates of fever resolution. Requiring fever resolution during neutropenia in a composite endpoint can mask more clinically relevant outcomes.
Treatment of multidrug‐resistant cytomegalovirus retinitis with systemically administered leflunomide
Authors: Levi M.E. , Mandava N. , Chan L.K. , Weinberg A. , Olson J.L.
Published: April 2006

Abstract: Multiresistant cytomegalovirus (CMV) infection is increasingly recognized in solid organ transplant recipients. Leflunomide is a novel drug with both immunosuppressive and anti‐CMV properties. Herein we report a case of a renal transplant recipient treated with leflunomide for multiresistant CMV retinitis, and provide correlation between serum and vitreous levels of leflunomide. She had stabilization of her retinitis and measurable levels of drug in her vitreous fluid and serum. These initial findings suggest that leflunomide may be useful in the treatment of CMV disease, including retinitis in patients after solid organ transplantation.