Influence of Sorghum Cultivar, Nitrogen Fertilization, and Insecticides on Infestations of the Sugarcane Aphid (Hemiptera: Aphididae) in the Southern United States.

The sugarcane aphid, Melanaphis sacchari Zehntner, is an economically damaging pest of sorghum, Sorghum bicolor (L.), across the southern United States. Field experiments investigated impacts of sorghum cultivar, nitrogen fertilization, and insecticides on M. sacchari infestations and sorghum yields in Louisiana and South Carolina in 2017 and 2018. In South Carolina, M. sacchari densities in unprotected plots peaked on 30-31 July of both years before declining by early- to mid-August. In Louisiana, infestations peaked on 26 and 12 July for 2017 and 2018, respectively, and declined by mid-August. Nitrogen fertilization influenced M. sacchari densities in Louisiana in 2018 with the highest-level infestations recorded from plots that received high N rates. Densities of M. sacchari on susceptible sorghum cultivar, DKS 38-88, were 1.5- to 2.3-fold greater than on DKS 37-07 in both years in Louisiana and in 2018 in South Carolina. Nitrogen fertilization was associated with improved sorghum yields in Louisiana experiments. Sorghum yields across experiments were 2- to 4-fold greater in plots protected with multiple insecticide applications than in unprotected plots. Yield from plots with insecticides sprayed once at currently used action thresholds differed from unprotected plots only in the 2018 Louisiana experiment. Results from these experiments indicate insecticidal protection of susceptible sorghum cultivars remains critical throughout much of the southern United States. Further research is needed to develop integrated management programs that incorporate fertilization manipulation, cultivar resistance, and insecticidal control.

Clinical experience of intracranial chordoma - A systematic review and meta-analysis of the literature.

Chordomas are rare neoplasms of the axial skeleton, with a predilection for the clival region. The lack of data about intracranial chordomas has led to inconsistent reporting of their clinical behavior and management principles. We performed a systematic review and meta-analysis with the aim of reporting on clinical behavior and management in the literature. We performed an electronic search of the MEDLINE, EMBASE, LILACS, Web of Science, Cochrane, and CINAHL databases. We included studies of patients with intracranial chordoma that had undergone surgical management with 5-year data available. The weighted mean estimate of 5-year OS was 77.4% (95% CI, 72.9-81.7%) whilst the 5-year PFS estimate was 49.4% (95% CI, 41.6-57.3%). A wide variety of surgical approaches were utilised, with transcranial approaches being the commonest. Surgeons achieved gross total resection in 29.4% of cases (95% CI, 17.6-43.0%), Sub-total resection in 60.9% of cases (95% CI, 40.2-79.8%) and partial resection in 19.7% (95% CI; 11.9 to 28.9%). The total complication rate was 28.5% (95% CI, 18.4-39.8%), with the commonest being new cranial nerve palsy (weighted mean 11.1%, 95% CI, 7.11-15.7%). Our review demonstrates that a wide range of management options exist in the literature. These should be tailored to each patient based on factors including tumoral location, local involvement and capabilities of the surgical team. The outcomes of chordoma management have largely been stable with no improvement despite improvements in modern surgical techniques.

Interleukin-22 regulates antimicrobial peptide expression and keratinocyte differentiation to control Staphylococcus aureus colonization of the nasal mucosa.

The local immune response occurring during Staphylococcus aureus nasal colonization remains ill-defined. Studies have highlighted the importance of T-cell immunity in controlling S. aureus colonization of the nasal mucosa. We extend these observations, identifying a critical role for interleukin (IL)-22 in this process. IL-22 is basally expressed within the nasal mucosa and is induced upon S. aureus colonization. IL-22 is produced by CD4+ and CD8+ T lymphocytes at this site, with innate-like lymphocytes also contributing. IL-22-/- mice demonstrate significantly elevated levels of S. aureus nasal colonization as compared with wild-type (WT) mice. This was associated with reduced expression of antimicrobial peptides (AMPs) in the nose. Furthermore, expression of staphylococcal ligands loricrin and cytokeratin 10 was higher in the noses of IL-22-/- as compared with WT mice. IL-17 has been shown to regulate S. aureus nasal colonization by controlling local neutrophil responses; however, IL-17 expression and neutrophil responses were comparable in the noses of IL-22-/- and WT mice during S. aureus colonization. We conclude that IL-22 has an important role in controlling S. aureus nasal colonization through distinct mechanisms, with IL-22 mediating its effect exclusively by inducing AMP expression and controlling availability of staphylococcal ligands.

A pilot study on the feasibility of European harmonized human biomonitoring: Strategies towards a common approach, challenges and opportunities.

In 2004 the European Commission and Member States initiated activities towards a harmonized approach for Human Biomonitoring surveys throughout Europe. The main objective was to sustain environmental health policy by building a coherent and sustainable framework and by increasing the comparability of data across countries. A pilot study to test common guidelines for setting up surveys was considered a key step in this process. Through a bottom-up approach that included all stakeholders, a joint study protocol was elaborated. From September 2011 till February 2012, 17 European countries collected data from 1844 mother-child pairs in the frame of DEMOnstration of a study to COordinate and Perform Human Biomonitoring on a European Scale (DEMOCOPHES).(1) Mercury in hair and urinary cadmium and cotinine were selected as biomarkers of exposure covered by sufficient analytical experience. Phthalate metabolites and Bisphenol A in urine were added to take into account increasing public and political awareness for emerging types of contaminants and to test less advanced markers/markers covered by less analytical experience. Extensive efforts towards chemo-analytical comparability were included. The pilot study showed that common approaches can be found in a context of considerable differences with respect to experience and expertize, socio-cultural background, economic situation and national priorities. It also evidenced that comparable Human Biomonitoring results can be obtained in such context. A European network was built, exchanging information, expertize and experiences, and providing training on all aspects of a survey. A key challenge was finding the right balance between a rigid structure allowing maximal comparability and a flexible approach increasing feasibility and capacity building. Next steps in European harmonization in Human Biomonitoring surveys include the establishment of a joint process for prioritization of substances to cover and biomarkers to develop, linking biomonitoring surveys with health examination surveys and with research, and coping with the diverse implementations of EU regulations and international guidelines with respect to ethics and privacy.

Temsirolimus combined with sorafenib in hepatocellular carcinoma: a phase I dose-finding trial with pharmacokinetic and biomarker correlates.

BACKGROUND: Based upon preclinical evidence for improved antitumor activity in combination, this phase I study investigated the maximum-tolerated dose (MTD), safety, activity, pharmacokinetics (PK), and biomarkers of the mammalian target of rapamycin inhibitor, temsirolimus, combined with sorafenib in hepatocellular carcinoma (HCC). PATIENTS AND METHODS: Patients with incurable HCC and Child Pugh score ≤B7 were treated with sorafenib plus temsirolimus by 3 + 3 design. The dose-limiting toxicity (DLT) interval was 28 days. The response was assessed every two cycles. PK of temsirolimus was measured in a cohort at MTD. RESULTS: Twenty-five patients were enrolled. The MTD was temsirolimus 10 mg weekly plus sorafenib 200 mg twice daily. Among 18 patients at MTD, DLT included grade 3 hand-foot skin reaction (HFSR) and grade 3 thrombocytopenia. Grade 3 or 4 related adverse events at MTD included hypophosphatemia (33%), infection (22%), thrombocytopenia (17%), HFSR (11%), and fatigue (11%). With sorafenib, temsirolimus clearance was more rapid (P < 0.05). Two patients (8%) had a confirmed partial response (PR); 15 (60%) had stable disease (SD). Alpha-fetoprotein (AFP) declined ≥50% in 60% assessable patients. CONCLUSION: The MTD of sorafenib plus temsirolimus in HCC was lower than in other tumor types. HCC-specific phase I studies are necessary. The observed efficacy warrants further study.

The effects of bevacizumab on postoperative complications in patients undergoing colorectal and pancreatic cancer resection.

Bevacizumab (Avastin™; rhuMab VEGF), a monoclonal antibody targeting vascular endothelial growth factor (VEGF), has seen increased use in the perioperative treatment of colorectal and pancreatic cancer. Little is known, however, regarding its impact on surgical outcomes in patients undergoing resection. The objective of this review was to examine if the addition of bevacizumab to existing neoadjuvant regimens increases morbidity after cancer resection.

Dermatologic infections in cancer patients treated with epidermal growth factor receptor inhibitor therapy.

BACKGROUND: Patients treated with epidermal growth factor receptor inhibitors (EGFRIs) frequently experience dermatologic toxic effects. Whereas the impact of these effects on quality of life and EGFRI dosing has been described, their impact on physical health has not been ascertained. We examined the prevalence of infections that complicate dermatologic toxic effects of EGFRIs. METHODS: We used retrospective chart review methods to analyze 221 patients who were treated in the Skin and Eye Reactions to Inhibitors of EGFR and Kinases clinic, a referral clinic for dermatologic toxic effects of cancer therapies. We reviewed results of bacterial cultures, histopathologic assessment of biopsy samples, and immunohistochemical staining of skin specimens for viral pathogens that were recorded in the patients' medical records. Associations between patient demographic and treatment characteristics and the development of infections were examined using the Fisher exact test. All statistical tests were two-sided. RESULTS: Eighty-four (38%) of the 221 patients showed evidence of infection at sites of dermatologic toxic effect. Fifty (22.6%) of the 221 patients had cultures positive for Staphylococcus aureus, and 12 (5.4%) of the 221 patients cultured positive for methicillin-resistant S aureus. Less frequent infections included herpes simplex (3.2%), herpes zoster (1.8%), and dermatophytes (10.4%). The seborrheic region was the most prevalent site of infection, and patients with leukopenia had higher risk for infection than patients who did not have leukopenia (P = .005). Demographic factors and associated treatments were not associated with the occurrence of a dermatologic infection (P > or = .05). CONCLUSIONS: Patients with dermatologic toxic effects following treatment with EGFRIs have a high prevalence of cutaneous infections. Most notably, bacterial infections developed at sites previously affected by dermatologic toxic effects, with leukopenic patients being at greater risk.

A comparative analysis of transarterial downstaging for hepatocellular carcinoma: chemoembolization versus radioembolization.

Chemoembolization and other ablative therapies are routinely utilized in downstaging from United Network for Organ Sharing (UNOS) T3 to T2, thus potentially making patients transplant candidates under the UNOS model for end-stage liver disease (MELD) upgrade for hepatocellular carcinoma (HCC). This study was undertaken to compare the downstaging efficacy of transarterial chemoembolization (TACE) versus transarterial radioembolization. Eighty-six patients were treated with either TACE (n = 43) or transarterial radioembolization with Yttrium-90 microspheres (TARE-Y90; n = 43). Median tumor size was similar (TACE: 5.7 cm, TARE-Y90: 5.6 cm). Partial response rates favored TARE-Y90 versus TACE (61% vs. 37%). Downstaging to UNOS T2 was achieved in 31% of TACE and 58% of TARE-Y90 patients. Time to progression according to UNOS criteria was similar for both groups (18.2 months for TACE vs. 33.3 months for TARE-Y90, p = 0.098). Event-free survival was significantly greater for TARE-Y90 than TACE (17.7 vs. 7.1 months, p = 0.0017). Overall survival favored TARE-Y90 compared to TACE (censored 35.7/18.7 months; p = 0.18; uncensored 41.6/19.2 months; p = 0.008). In conclusion, TARE-Y90 appears to outperform TACE for downstaging HCC from UNOS T3 to T2.

A phase II study of pegylated-camptothecin (pegamotecan) in the treatment of locally advanced and metastatic gastric and gastro-oesophageal junction adenocarcinoma.

PURPOSE: Combination chemotherapy results in a significant survival advantage in patients with advanced gastric cancer compared to best supportive care. Nevertheless, the prognosis remains poor with a median survival of 8-10 months. Topoisomerase-I inhibitors such as irinotecan have activity in advanced gastric cancer. Pegamotecan may offer significant advantages over other topoisomerase-I inhibitors due to its prolonged circulating half-life, tolerability and passive tumour accumulation. PATIENTS AND METHODS: This was a non-randomised, multi-centre, two-step Fleming design phase II study. Eligible patients with locally advanced (inoperable) or metastatic gastric or gastro-oesophageal adenocarcinoma, with measurable disease, ECOG performance status < or =2, with adequate haematological, renal and hepatic function, who had received < or =1 prior chemotherapy regimen for advanced disease, were treated with 7,000 mg/m(2) of pegamotecan as a 1-h infusion every 21 days until disease progression or unacceptable toxicity. The primary efficacy measure was the objective response rate. RESULTS: Five of the 35 patients recruited into this study had a partial response (14.3%), with a median time to progression of 11.9 weeks (95% CI: 6.6, 13.1), and median overall survival of 38.1 weeks (95% CI: 29.0, 47.3). Grade 3/4 toxicities included neutropenia in 6 (17.1%) patients, thrombocytopenia in 4 (11.4%), fatigue in 8 (22.9%), nausea in 6 (17%), vomiting in 6 (17%) and anorexia in 4 (11.4%) patients. There were no episodes of febrile neutropenia and no toxic deaths. CONCLUSIONS: Pegamotecan has activity in this patient population and was generally well-tolerated. The favourable rate of haematological toxicities and diarrhoea compared with irinotecan in similar studies suggests that pegamotecan could be combined with other active agents in further studies in this disease.

Fibrosis, portal hypertension, and hepatic volume changes induced by intra-arterial radiotherapy with 90yttrium microspheres.

PURPOSE: To identify changes in hepatic parenchymal volume, fibrosis, and induction of portal hypertension following radioembolization with glass microspheres for patients with metastatic disease to the liver. RESULTS: In our series of sequential bilobar (n = 17) treatments, a mean decrease in liver volume of 11.8% was noted. In this group, a mean splenic volume increase of 27.9% and portal vein diameter increase of 4.8% were noted. For patients receiving unilobar treatments (n = 15), mean ipsilateral lobar volume decrease of 8.9%, contralateral lobar hypertrophy of 21.2%, and a 5.4% increase in portal vein diameter were also noted. These findings were not associated with clinical toxicities. CONCLUSION: (90)Yttrium radioembolization utilizing glass microspheres in patients with liver metastases results in changes of hepatic parenchymal volume and also induced findings suggestive of fibrosis and portal hypertension. Further studies assessing the long-term effects are warranted.

Investigating the possible role of benthic macroinvertebrates and zooplankton in the life cycle of the haplosporidian Bonamia ostreae.

Bonamia ostreae is a protistan parasite of the European flat oyster, Ostrea edulis. Though direct transmission of the parasite can occur between oysters, it is unclear if this represents the complete life cycle of the parasite, and the role of a secondary or intermediate host or carrier species cannot be ruled out. In this preliminary study, benthic macroinvertebrates and zooplankton from a B. ostreae-endemic area were screened for the presence of parasite DNA, using polymerase chain reaction (PCR). Eight benthic macroinvertebrates and nineteen grouped zooplankton samples gave positive results. Certain species, found positive for the parasite DNA, were then used in laboratory transmission trials, to investigate if they could infect naïve oysters. Transmission of B. ostreae was effected to two naïve oysters cohabiting with the brittle star, Ophiothrix fragilis.

Microfauna associated with amoebic gill disease in sea-farmed Atlantic salmon, Salmo salar L., smolts.

A study of microfauna, associated with pathological changes in the gills of Atlantic salmon, Salmo salar L., was conducted over 2001-2002. Monthly samples of 1(+) salmon smolts were taken, protozoan populations were quantified and gill health was assessed histologically. Protozoan densities were correlated with pathological changes, in order to determine their possible role in lesions in the gills. The most severe gill tissue changes were observed in summer/autumn and the least in spring. A diverse polyphyletic protozoan community was observed colonizing the gills, including Neoparamoeba sp., other amoebae, scuticociliates, Ichthyobodo-like flagellates, trichodinid ciliates and prostomatean ciliates. The earlier gill tissue changes in the gill were not always associated with the presence of these microorganisms, whereas amoebae (other than Neoparamoeba sp.), Ichthyobodo-like flagellates and trichodinid ciliates correlated with augmenting gill lesions. Neoparamoeba sp. was present, but its abundance did not correlate with the disease. This study suggests that a diversity of protozoans including Ichthyobodo-like flagellates, trichodinid ciliates and amoebae other than Neoparamoeba sp. are involved in the aetiology of amoebic gill disease in the Irish situation.

Reductions in tobacco smoke pollution and increases in support for smoke-free public places following the implementation of comprehensive smoke-free workplace legislation in the Republic of Ireland: findings from the ITC Ireland/UK Survey.

OBJECTIVE: To evaluate the psychosocial and behavioural impact of the first ever national level comprehensive workplace smoke-free law, implemented in Ireland in March 2004. DESIGN: Quasi-experimental prospective cohort survey: parallel cohort telephone surveys of national representative samples of adult smokers in Ireland (n = 769) and the UK (n = 416), surveyed before the law (December 2003 to January 2004) and 8-9 months after the law (December 2004 to January 2005). MAIN OUTCOME MEASURES: Respondents' reports of smoking in key public venues, support for total bans in those key venues, and behavioural changes due to the law. RESULTS: The Irish law led to dramatic declines in reported smoking in all venues, including workplaces (62% to 14%), restaurants (85% to 3%), and bars/pubs (98% to 5%). Support for total bans among Irish smokers increased in all venues, including workplaces (43% to 67%), restaurants (45% to 77%), and bars/pubs (13% to 46%). Overall, 83% of Irish smokers reported that the smoke-free law was a "good" or "very good" thing. The proportion of Irish homes with smoking bans also increased. Approximately 46% of Irish smokers reported that the law had made them more likely to quit. Among Irish smokers who had quit at post-legislation, 80% reported that the law had helped them quit and 88% reported that the law helped them stay quit. CONCLUSION: The Ireland smoke-free law stands as a positive example of how a population-level policy intervention can achieve its public health goals while achieving a high level of acceptance among smokers. These findings support initiatives in many countries toward implementing smoke-free legislation, particularly those who have ratified the Framework Convention on Tobacco Control, which calls for legislation to reduce tobacco smoke pollution.

Secondhand smoke exposure and risk following the Irish smoking ban: an assessment of salivary cotinine concentrations in hotel workers and air nicotine levels in bars.

OBJECTIVE: To investigate whether the Irish smoking ban has had an impact on secondhand smoke (SHS) exposures for hospitality workers. DESIGN, SETTING, AND PARTICIPANTS: Before and after the smoking ban a cohort of workers (n = 35) from a sample of city hotels (n = 15) were tested for saliva cotinine concentrations and completed questionnaires. Additionally, a random sample (n = 20) of city centre bars stratified by size (range 400-5000 square feet), were tested for air nicotine concentrations using passive samplers before and after the ban. MAIN OUTCOME MEASURES: Salivary cotinine concentrations (ng/ml), duration of self reported exposures to secondhand smoke, air nicotine (microg/cubic metre). RESULTS: Cotinine concentrations reduced by 69%, from 1.6 ng/ml to 0.5 ng/ml median (SD 1.29; p < 0.005). Overall 74% of subjects experienced decreases (range 16-99%), with 60% showing a halving of exposure levels at follow up. Self reported exposure to SHS at work showed a significant reduction from a median 30 hours a week to zero (p < 0.001). There was an 83% reduction in air nicotine concentrations from median 35.5 microg/m3 to 5.95 microg/m3 (p < 0.001). At baseline, three bars (16%) were below the 6.8 microg/m3 air nicotine significant risk level for lung cancer alone; at follow up this increased to 10 (53%). CONCLUSIONS: Passive smoking and associated risks were significantly reduced but not totally eliminated. Exposure to SHS is still possible for those working where smoking is still allowed and those working where smoke may migrate from outdoor areas. Further research is required to assess the true extent and magnitude of these exposures.

Environmental risk factors associated with amoebic gill disease in cultured salmon, Salmo salar L., smolts in Ireland.

A 2-year study was carried out on amoebic gill disease (AGD) involving monthly samples of 1+ Atlantic salmon, Salmo salar L., smolts, histological assessment of the gills and analysis of environmental data. Gill pathology was seen before amoebae could be detected microscopically. These changes in gill integrity were associated with marine environmental conditions, particularly elevated ammonium, nitrite and chlorophyll levels. The results suggest that the environmental changes predispose salmon to colonization by amoebae and ciliates. High densities of histophagous scuticociliates were observed in the gills during periods of advanced gill pathology. A number of different amoebae were observed in close association with gill pathology. Neoparamoeba was not seen in high densities, nor was it associated with gill pathology, indicating that Neoparamoeba may not be the primary agent of the AGD in Irish salmonid culture.

Small subunit ribosomal DNA characterization of an unidentified aurantiactinomyxon form and its oligochaete host Tubifex ignotus.

In this study, the small subunit (18S) ribosomal DNA gene from an aurantiactinomyxon form of unknown taxonomic position (A1) and from its aquatic oligochaete host (Tubifex ignotus) were characterized. Molecular sequence information on A1 was obtained to allow comparisons of this gene with known sequences from known myxosporean forms, and therefore to investigate possible relationships between this organism and its alternate myxosporean stage. Sequence data for the oligochaete host, together with morphological features, will allow reliable identification of this species in the future. Sequence data derived from the 18S DNA gene and data from other related or non-related organisms were analyzed and used to construct a phylogenetic tree. Phylogenetic studies provided an insight into the taxonomic position of A1. Sequence similarities within the 18S rDNA A1 gene and compared organisms indicated that A1 was most closely related to members of the sub-order Variisporina (Myxidium lieberkuehni [Ml] and Sphaerospora oncorhynchi [So]). Clustering of the 3 organisms in the same branch was well supported by high bootstrap values (81%). A1 showed higher similarities with sequences of Ml (approximately 80%) than with So (approximately 79%). Myxosporean sequence analysis indicated that phylogenetic arrangements do not support traditional classification based on morphological criteria of the spores, but rather support arrangement by tissue location. Marine actinosporeans Triactinomyxon sp. and Tetraspora discoidea were found to be associated with Platysporinid myxosporeans, supporting previous findings. In this study, 18S rDNA sequence data are generated for first time for the aquatic oligochaete T. ignotus. Phylogenetic 18S rDNA gene analyses performed with T. ignotus support and confirm existing morphological and molecular phylogenetic studies. Paraphyly of the Tubificidae family was noticed.

Susceptibility of three different strains of juvenile Atlantic halibut (Hippoglossus hippoglossus L.) cultured at two different temperatures to Vibrio anguillarum and temperature effect on antibody response.

Three geographically distinct-reared strains (Canadian, Icelandic, Norwegian) of juvenile Atlantic halibut (Hippoglossus hippoglossus L.) cultured at optimal and super-optimal growth temperatures (12 and 18 degrees C respectively), were challenged with a virulent isolate of Vibrio anguillarum by injection. The halibut were injected intraperitoneally with 100 microl of the bacterial suspension (1 x 10(6) cells per fish). After challenge, temperature and strain-related differences in survival were observed. Canadian and Icelandic halibut cultured at the super-optimal temperature of 18 degrees C were significantly more susceptible to infection than those strains cultured at 12 degrees C. Total mortality at 18 degrees C for the Canadian and Icelandic strains was 56.4 and 61.85% respectively, compared to 32 and 26.6% respectively at 12 degrees C. Norwegian halibut were significantly more resistant to infection with V. anguillarum at 18 degrees C compared to the other strains, with total mortality of 13.3%. There was no significant difference in total mortality of Norwegian halibut at 18 or 12 degrees C (13.3, 25% respectively). The specificity of the antibodies in sera from challenged halibut cultured at 18 degrees C was primarily to LPS. Immunoblots showed the presence of antibodies against O-side chain antigens. This reaction was strongest in sera from the Norwegian halibut strain compared with the Canadian and Icelandic halibut, which suggests that the difference in resistance to challenge may be ascribable to the presence of antibodies to LPS. Specific antibody levels, as measured by ELISA, increased with increasing temperature and strain differences were apparent, however these did not relate to disease resistance.

The effect of temperature on non-specific defence parameters of three strains of juvenile Atlantic halibut (Hippoglossus hippoglossus L.).

The effect of temperature (8, 12, 15 and 18 degrees C) on a variety of non-specific defence and haematological parameters was examined in three geographically distinct reared strains (Canadian, Icelandic, Norwegian) of Atlantic halibut. The results indicate that temperature exerts a considerable influence on some blood parameters (packed cell volume and the percentage population of leucocytes in peripheral blood) and on some humoral parameters (serum lysozyme activity and serum protein levels) of halibut. A high temperature of 18 degrees C caused a decrease in the number of circulating blood cells and an increase in serum lysozyme levels; effects consistent with those reported within the literature for stress. The different strains of halibut exhibited differing responses with respect to differential counts of peripheral blood lymphocytes and thrombocytes, and to serum protein concentrations, serum lysozyme activity, serum iron content, unsaturated iron binding capacity of serum and O2- production by kidney macrophages.

Lysozyme activity and protein concentration in the haemolymph of the flat oyster Ostrea edulis (L.).

Lysozyme activity and protein concentration in the haemolymph of the flat oyster Ostrea edulis were investigated. These biochemical constituents of the haemolymph could be an indication of the physiological condition and vitality of the defence system of an animal. Haemolymph protein and lysozyme in oysters were examined over an 18 month period to determine their relationship with the strain of oyster, the season, the site, and parasitism by Bonamia ostreae. Haemolymph protein concentration exhibited seasonal fluctuations and varied between strains. Levels of protein in oysters highly infected with B. ostreae were slightly depressed but not significantly so. Haemolymph lysozyme varied greatly between individuals but no correlation was found between lysozyme levels and infection of oysters by B. ostreae.