Prosorhynchoides borealis Bartoli, Gibson & Bray, 2006 (Digenea: Bucephalidae) cercariae from Abra prismatica (Mollusca: Bivalvia) in Icelandic waters.

This paper reports the adult stage of Prosorhynchoides borealis (Digenea) from Lophius piscatorius in Icelandic waters and infections with the larval stages (sporocysts and cercariae) found for the first time in the bivalve Abra prismatica (Semelidae). The previously known first intermediate host was Abra alba (Semelidae). Ribosomal DNA sequencing studies on all three life stages of the parasite (cercariae, metacercariae, adults) were performed to confirm their identites. Morphometric measurements confirmed that the adult worms belong to the newly described species P. borealis. Prosorhynchoides borealis sporocysts filled with cercariae were found in 16% of A. prismatica bivalves sampled at depths between 34 and 93 m off South Iceland. Prevalence ranged from 0 to 44% between different localities. The parasite was found only in the larger bivalves. Extensive sporocyst infection in the haemocoel of the foot caused mechanical muscle damage with subsequent degeneration and necrosis. Other tissues, including the digestive gland, nephridia, gills and intestine, were less heavily infected. Only focal necrosis was observed in the digestive gland, nephridia and gills, and local atrophy in the intestine. Cercariae were also observed in the lumen of both the stomach and intestine. This is the first report of A. prismatica as an alternative first intermediate host for P. borealis. Ribosomal DNA sequence data reveals 100% homology in the data between cercariae, metacercariae and adult digeneans, supporting the morphological data suggesting that all stages belong to the same species.

Progress of co-infections of Trichodina cooperi and T. murmanica parasitising farmed Atlantic cod Gadus morhua juveniles in Iceland.

Two year classes of wild cod juveniles, caught for on-rearing in shore-based tanks, were examined for Trichodina spp. infections at regular intervals for 9 mo. The prevalence, density and proportion of each species found was determined. Additionally, biomass, seawater temperature and salinity in the tanks was recorded regularly. Two species were identified: T. cooperi and T. murmanica. Their prevalence, density and proportion varied between sampling times, T. cooperi being the dominant species, more prevalent and in higher density in the beginning. In the following months, T. murmanica gradually increased its prevalence, density and proportion, reaching an almost total dominance in both year classes after 7 mo of rearing. The results indicate that the rearing environment on this farm favoured T. murmanica. Changes in salinity could explain this to some extent; a drop in salinity, due to an inflow of geothermal freshwater to control the temperature during the coldest months, coincided fairly well with an increasing proportion of T. murmanica. Transfer of wild fish into the rearing environment, with a subsequent increase in biomass, resulted in a proliferation of trichodinids. This may have altered the interaction between species and the competition for resources. It is conceivable that a higher host density favours one Trichodina species over the other. Temperature could also play a role. During the first 3 to 4 mo of rearing, the temperature in the tanks followed the temperature of the open sea, which dropped by 3 to 5 degrees C. This study is a part of a larger project on monitoring the progress of various infectious diseases in farmed cod of wild origin.

Immune parameters of immunised cod (Gadus morhua L.).

The immune response of cod (Gadus morhua L.) is unusual in that specific antibody response is limited or absent. In the present study cod was immunised with haptenated and non-haptenated protein antigen at two different temperatures and the antibody response monitored over a period of 18 months. Other humoral parameters of immunological importance were also analysed, namely total immunoglobulin concentration, anti-protease and spontaneous haemolytic activity. No specific antibody response was detected but increased activity of non-specific anti-TNP antibodies was observed 10-12 weeks after immunisation, irrespective of the antigen used. This antibody activity was attributed to the adjuvant used (FCA) and did not cross react with other antigens tested. Other parameters were probably not influenced by the immunisation but seasonal fluctuations were indicated. The immunoglobulin level appeared to peak in August-September and the anti-protease activity and the haemolytic activity in October-January.

Prevalence of postherpetic neuralgia after a first episode of herpes zoster: prospective study with long term follow up.

OBJECTIVE: To estimate the frequency, duration, and clinical importance of postherpetic neuralgia after a single episode of herpes zoster. DESIGN: Prospective cohort study with long term follow up. SETTING: Primary health care in Iceland. PARTICIPANTS: 421 patients with a single episode of herpes zoster. MAIN OUTCOME MEASURES: Age and sex distribution of patients with herpes zoster, point prevalence of postherpetic neuralgia, and severity of pain at 1, 3, 6, and 12 months and up to 7.6 years after the outbreak of zoster. RESULTS: Among patients younger than 60 years, the risk of postherpetic neuralgia three months after the start of the zoster rash was 1.8% (95% confidence interval 0.59% to 4.18%) and pain was mild in all cases. In patients 60 years and older, the risk of postherpetic neuralgia increased but the pain was usually mild or moderate. After three months severe pain was recorded in two patients older than 60 years (1.7%, 2.14% to 6.15%). After 12 months no patient reported severe pain and 14 patients (3.3%) had mild or moderate pain. Seven of these became pain free within two to seven years, and five reported mild pain and one moderate pain after 7.6 years of follow up. Sex was not a predictor of postherpetic neuralgia. Possible immunomodulating comorbidity (such as malignancy, systemic steroid use, diabetes) was present in 17 patients. CONCLUSIONS: The probability of longstanding pain of clinical importance after herpes zoster is low in an unselected population of primary care patients essentially untreated with antiviral drugs.

Characterization of Vibrio viscosus and Vibrio wodanis isolated at different geographical locations: a proposal for reclassification of Vibrio viscosus as Moritella viscosa comb. nov.

Vibrio viscosus and Vibrio wodanis are recently described species of psychrotropic bacteria that have been found associated with a disease called 'winter ulcer', affecting salmonid fish reared in saline water in Norway, Iceland and recently in Scotland. V. viscosus and V. wodanis strains initially isolated from fish in Iceland and Norway were subjected to characterization using biochemical tests, SDS-PAGE of whole-cell proteins and a novel DNA fingerprinting method, amplified fragment length polymorphism (AFLP). The V. viscosus strains isolated from diseased fish grouped into homogeneous subgroups according to geographical origin and challenge experiments revealed that representatives of these groups are virulent. The results revealed that the V. wodanis strains are heterogeneous genotypically and phenotypically. Sequencing of almost complete 16S rRNA genes of V. viscosus and V. wodanis revealed that V. viscosus showed a 99.1% sequence similarity to Moritella marina and V. wodanis showed a 98.8% sequence similarity to Vibrio logei CIP 103204. A reclassification of Vibrio viscosus as Moritella viscosa comb. nov. is proposed.

Humoral immune parameters in Atlantic cod (Gadus morhua L.) I. The effects of environmental temperature.

The effects of environmental temperature on certain humoral immune parameters in Atlantic cod (Gadus morhua L.) were studied. Serum samples were collected from captive cod, of wild origin, kept at different temperatures for 12 months. It was found that immunoglobulin and natural antibody levels increased with increasing temperature whereas the total serum protein concentration, anti-protease activity, iron concentration, unsaturated and total iron binding capacity decreased with increasing temperature. Haemolytic activity and percentage iron saturation also tended to decrease with increasing temperature although this was not statistically significant.

Humoral immune parameters in Atlantic cod (Gadus morhua L.) II. The effects of size and gender under different environmental conditions.

The effects of size and gender on several humoral immune parameters in cod were examined under different environmental conditions. Serum samples were collected from wild cod of different sizes. Two samplings were undertaken: In the spring in relatively cold waters off the north west coast of Iceland and in the fall in relatively warm waters off the west coast of Iceland. Most of the parameters increased with increasing cod size, except the haemolytic activity which decreased. Higher serum protein levels were seen in cod sampled in the fall than in the spring. In cod sampled in the spring there was an apparent difference between specimens < 75 cm in length and the larger specimens with respect to haemolytic activity and iron concentration. None of the parameters were influenced by the gender of the cod.

Herpes zoster in children and adolescents.

OBJECTIVES: To follow the clinical course of herpes zoster and to determine the incidence, frequency of complications and association with malignancy in children and adolescents. DESIGN: Prospective cohort study in a primary health care setting in Iceland. The main outcome measures were age and sex distribution of patients and discomfort or pain 1, 3 and 12 months after the rash and general health before and 3 to 6 years after the zoster episode. RESULTS: During observation of the target population for a period of 75750 person years, 121 episodes of acute zoster developed (incidence 1.6/1000/year) in 118 patients. End points were gained for all 118 patients after 554 person years of follow-up. Systemic acyclovir was never used. No patient developed postherpetic neuralgia, moderate or severe pain or any pain lasting longer than 1 month from start of the rash (95% confidence interval, 0 to 0.03). Potential immunomodulating conditions were diagnosed in 3 patients (2.5%) within 3 months of contracting zoster. Only 5 (4%) had a history of severe diseases. CONCLUSIONS: The probability of postherpetic neuralgia in children and adolescents is extremely low. Zoster is seldom associated with undiagnosed malignancy in the primary care setting.

Identification of atypical Aeromonas salmonicida: inter-laboratory evaluation and harmonization of methods.

The atypical isolates of Aeromonas salmonicida are becoming increasingly important as the frequency of isolation of bacteria belonging to this group continues to rise. The primary object of this study was to compare and evaluate the results obtained in various laboratories concerning the biochemical identification of atypical Aer. salmonicida before and after standardization of media and methods. Five laboratories examined 25 isolates of Aer. salmonicida from diverse fish species and geographical locations including the reference strains of Aer. salmonicida subsp. salmonicida (NCMB 1102) and Aer. salmonicida subsp. achromogenes (NCMB 1110). Without standardization of the methods, 100% agreement was obtained only for two tests: motility and ornithine decarboxylase. The main reason for the discrepancies found was the variation of the incubation time prior to reading the biochemical reactions. After standardization, improvement was obtained with the identification; however, disagreement was still observed between the different laboratories. These findings demonstrate the difficulties involved in a proper identification of atypical Aer. salmonicida and also that data presented in the literature on various strains of Aer. salmonicida are not readily comparable. This paper seems to be the first on standardization of microbiological tests for identification of fish pathogens and the results obtained show the need for standardization of methods both within and between laboratories.

Short-term physiological changes in turbot and seabream juveniles exposed to exogenous ammonia.

Seabream and turbot juveniles (40-520 g) were exposed to constant exogenous NH5-N concentrations (1.27-4.27 mmol/l; pH, 8.15). In 96 hr acclimated fish, plasma TA-N (total ammonia nitrogen) contents were positively correlated to ambient ammonia concentrations. The LD50 were 2.2-2.5 mmol/l TA-N in both species. There were no marked osmoregulatory disturbances and plasma urea-N, thyroid hormones levels and gill (Na-K)-ATPase activities were only affected at the highest concentrations. Liver GOT, GPT and GIDH activity dose-response were low and species dependent. In cannulated and non-cannulated turbot exposed to half 96 hr LC50 (lethal ambient concentration for 50% of the population), there was a rapid, pronounced and prolonged increase in plasma TA-N, followed by an immediate decline when exogenous ammonia supply was stopped. Maximum loading and unloading were observed within 1-3 hr. Plasma cortisol levels indicated a stressful situation in exposed fish (150 ng/ml) and a quick recovery capacity. In dose and time response experiments, the most relevant physiological indicator of ammonia stress was blood TA-N content. Other parameters tested led either to transient or low amplitude responses except when fish approached death.

[Research in bacterial diseases of salmonid fish.].

The main bacterial diseases in Icelandic aquaculture are furunculosis, bacterial kidney disease (BKD) and vibriosis. Atypical furunculosis caused by A. salmonicida ssp. achromogenes is an endemic disease causing high mortality in salmonids yearly. Classical furunculosis caused by A. salmonicida ssp. salmonicida was first diagnosed in Iceland in 1995. At Keldur the research focus has been on studying the virulence mechanism of A. salmonicida ssp. achromogenes, the immune response evoked in the fish, and vaccine development. Farmed salmonids have been vaccinated with good results against atypical furunculosis with an autogenous bacterin since 1992. Recent results indicate some crossprotection of the autogenous bacterin of A. salmonicida ssp. achromogenes against classical furunculosis. BKD caused by Renibacterium salmoninarum is another endemic disease in Iceland. An intensive program for brood fish screening has been developed. Fertilized eggs from all infected parents are destroyed which has proved to be highly successful for controlling BKD. ELIS A and PCR methods for rapid diagnosis have been developed. BKD in wild stocks of trout is presently being studied. A variety of Vibrio spp. strains have been isolated from skin lesions of infected salmon. Antibiotics and autogeneous vaccines have been used for disease control with good results. Enteric redmouth disease caused by Yersinia ruckeri has once been diagnosed from farmed salmon in 1990.

A comparative study of the estrogenic effects of tamoxifen and 17 beta-estradiol in postmenopausal women.

The effects of tamoxifen and 17 beta-estradiol on the levels of FSH, PRL, and pregnancy zone protein were compared in two groups of postmenopausal women. Seventeen women with breast cancer were treated with tamoxifen (20 mg, twice a day). Fourteen women with climacteric complaints were given 17 beta-estradiol (2 mg, daily). A close parallelism between the effects of 17 beta-estradiol and the antiestrogen was obtained in all three markers studied. The percent decreases in FSH after 1 month were 29 and 44 and, after 3 months, 26 and 34 in the tamoxifen and estradiol groups, respectively. The decreases in PRL after 1 and 3 months of treatment with tamoxifen were 36% and 71%, and 19% and 31% after treatment with estradiol. Both treatments increased PZP serum levels, tamoxifen by 32% and 44% and estradiol by 55% and 70% after 1 and 3 months. Thus, tamoxifen was found to exert weak estrogenic effects in postmenopausal women.

A comparative longitudinal study on sex hormone binding globulin capacity during estrogen replacement therapy.

An aqueous two-phase equilibrium partition system was used to assay SHBG-binding capacity. Sera from groups of postmenopausal women before and during unopposed estrogen replacement therapy were analyzed. The induction of SHBG showed considerable differences between different estrogens. Ethinyl-estradiol in a daily dose of 0.05 mg gave a 70% increase in the serum concentration of this liver derived protein. Estradiol-17 beta, 2 mg daily and estrone sulphate 1.25 mg gave moderate changes, whereas estriol in different doses had no effect. SHBG induction may reflect estrogen overtreatment.

Estrogen replacement therapy after the menopause. Estrogenicity and metabolic effects.

Certain metabolic effects were investigated in post-menopausal women undergoing oral estrogen replacement therapy for 6 months using various substances. The increases in serum concentration of the estrogen-sensitive proteins, pregnancy zone protein (PZP), and sex hormone binding globulin (SHBG) had very similar and dose-dependent patterns. Ethinyl-estradiol was found to be much more potent than the "natural" estrogens. Estriol in various doses did not increase the protein level. Gonadotropin inhibition occurred in a dose-dependent manner. In terms of FSH suppression ethinyl-estradiol was approximately 120 times as potent as the "natural" estrogens. There was a striking resemblance between the "estrogenicity" of four different estrogens when expressed both in inhibition of gonadotropins and in induction of the two serum proteins SHBG and ceruloplasmin. Estriol caused a significant depression of FSH when given orally in a dose of 2 mg three times daily. Prolactin was found to decrease during treatment with low doses of estrogens. Estrogen therapy was found to have only moderate effects on adrenal androgens. Tamoxifen, and anti-estrogen, was found to exert distinctly estrogenic effects during treatment of post-menopausal women. In post-menopausal women with low amounts of circulating estrogens the tamoxifen-receptor complex itself may produce a net estrogenic response. Serum samples from post-menopausal women treated with ethinyl estradiol 0.05 mg and estrone sulphate 2.5 mg daily were found to reduce the lymphocyte reactivity in mixed lymphocyte cultures.

Estrogenic potency of oral replacement therapy estimated by the induction of pregnancy zone protein.

The induction of a highly estrogen-inducible plasma protein, the pregnancy zone protein/pregnancy associated alpha 2-globulin (PZP/PA alpha 2 G), was used to design a sensitive method to quantify and compare the potency of various estrogens commonly used in clinical practice. Serum PZP levels were followed in 100 post-menopausal women during 6 months' estrogen replacement therapy. Ethinyl estradiol caused more marked changes than the natural estrogens. Conjugated estrogens were more potent than estrone sulphate and estradiol-17 beta which had similar values. Estriol, irrespective of daily dosage, exerted a negative effect. The following sequence of equipotency was calculated: ethinyl estradiol = 100 x conjugated estrogens = 450 x estrone sulphate = 500 x estradiol-17 beta = 650 x estradiol valerate. These data were compared with other estimates of estrogenic potency from the literature. Compared with other clinical methods, PZP induction offers several advantages. Factors such as intestinal absorption, protein binding and intracellular metabolism are included in the net result of an increased protein synthesis which is easily followed in patients' sera during therapy.

Effects of various oestrogens on circulating androgens and cortisol during replacement therapy in post-menopausal women.

The influence of various oestrogens during unopposed replacement therapy on circulating androgens and cortisol was studied in 65 post-menopausal women. As dose dependent decrease in dehydroepiandrosterone sulphate (DHAS) was found. Ethinyloestradiol (0.05 mg daily) already gave a significant decrease after 1 mth of treatment. The decline following 17 beta-oestradiol (2 mg) and oestrone sulphate (2.5 mg) was less pronounced. Oestriol (6 mg daily) had no effect. Ethinyloestradiol also increased the levels of total cortisol and testosterone, probable because of serum protein induction, while 17 beta-oestradiol had no significant effect. Serum levels of androstenedione remained unchanged during therapy.

Comparison of four methods of differential typing of isolates of Shigella sonnei.

An epidemiological study of Sonne dysentery in Dundee during the years 1971-6 was made by examining, in respect of 1420 isolates of Shigella sonnei, the discriminating power of colicine typing, antibiogram testing, biotyping and resistotyping and the stabilty of the markers they provided. Colicine typing identified nine colicine types, including four not previously described. However, because types 4 and 4 var., determined by col Ib, and type U, producing no colicines, accounted for 96% of the isolates, discrimination with colicine typing was poor. In antibiotic sensitivity test, 13 different antibiogram patterns were noted. Less than 1% of the isolates were sensitive to all of the eight antibiotics tested; most were multiply drug-resistant. Resistance to kanamycin, neomycin and paromomycin (KNP) was apparently due to a single resistance determinant, widely distributed in a majority (53%) of the isolates. When definitive times were chosen for reading each biotyping test, only maltose and rhamnose of the 13 "sugars' tested differentiated isolates into prompt- and late-fermenting types. Though the ability to ferment rhamnose was a stable property, it discriminated only 1.5% of the minority, late-fermenting type. Resistotyping with six chemicals discriminated eight epidemiologically valid resistotypes, including three new types. However, 93 of the isolates belonged to only three resistotypes. Analysis of the data for isolated from 286 epidemiologically distinct episodes showed that the variability of colicine and antibiogram characters, found among isolates within, respectively, 40 and 28% of the episodes, was generally associated with loss or gain of a plasmid ("col Ib-KNP') which determined production of colicine Ib and KNP resistance. These characters varied both in vivo and in vitro. Variability of resistotype characters, on the other hand, was observed in only 28 (9%) episodes, 14 of which possibly represented examples of mixed or sequential infections. For accurate epidemiological tracing of strains of Sh. sonnei in a community, resistotyping, the technique showing the greatest discrimination and least variability of the four tested, should be included as the principal typing method.

Discrimination by multiple typing of isolates of Shigella sonnei in Dundee (1971-6).

Different strains of Shigella sonnei present in Dundee from 1971 to 1976 were identified by a "multiple typing' method in which resistotyping, used as the main method of differentiation, was supplemented by colicine typing, antibiogram testing and biotyping. At least 19 different "multiple types' (MTs) were identified by combining information from the four typing techniques. The relation of the different types and their possible derivation from each other are discussed. The practical value of multiple typing was demonstrated in a study of 247 isolates, of three distinct MTs, recovered from 178 persons involved in an extended outbreak centred primarily on day nurseries. A few episodes that yielded isolates of different resistotypes were analysed to determine whether the cultures were: isolates of the same strain different in resistotype as a result of in vivo or in vitro variation of resistotype characters, or isolates of distinct strains of different resistotypes. The multiple typing approach clarified the way in which different MTs emerged, persisted, disappeared or co-existed in the community during the 6 years of the study.