Introduction: Improved aquatic animal health management is vital to aquaculture's role in global food security

Global food security and nutrition depend heavily on aquaculture, the continued growth of which is crucial as the world heads towards a human population of at least 9 billion by 2050, while harvests from wild capture will, at best, stabilise at current levels. Thus, a fundamental question is: how can we sustainably increase aquatic food production? It is clear that aquatic animal diseases present a substantial threat and, consequently, aquatic animal health management has a critical role in food security. An ecosystem approach to aquaculture will mitigate impacts on ecosystem services and biodiversity, and provide the necessary resilience to future disease threats, including those exacerbated by climate change. Due to the nature of aquatic production systems, this approach must encompass fisheries and other sectors that share the same resources. Improved aquatic animal health management must be a key component of aquaculture's future. At the national level, public-private partnerships are vital in achieving objectives of common benefit. Improved disease reporting and response is critical in the control of listed and emerging diseases and can only be achieved through government, industry and stakeholder collaboration. Great potential exists to improve biosecurity from the farm to national level, but this will only be achieved through collaboration. Industry cannot develop effective biosecurity without a clear government strategy and support, specifically legislation which provides an effective framework for safe trade. Governments have a key role in creating a regulatory environment that supports effective biosecurity and is attractive to investment; such as one that supports the development and regulatory approval of therapeutics. The improved control of transboundary diseases requires the wider and more consistent implementation of OIE standards, particularly on disease notification. This can only be achieved through improved collaboration between trading partners and by supporting low- and middle-income countries to strengthen their aquatic animal health services. There is incredible potential for aquaculture to continue its rapid growth and increase its contribution to global food security. However, sustainable growth of aquaculture is threatened by both known diseases, which we cannot effectively control, and new diseases, which may become pandemic. Recent pandemics have shown that global production systems are epidemiologically connected and, consequently, aquatic animal diseases present a shared global threat that demands global solidarity. The world now depends on a sustainable future for aquaculture and improved aquatic animal health management is critical to its continued and growing contribution to global food security.

A new approach to the management of emerging diseases of aquatic animals

Since 1970, aquaculture has grown at a rate of between 5% and 10% per annum. It has achieved this by expanding into new areas, farming new (often non-native) species and intensifying production. These features of aquaculture, combined with large-scale movements of animals, have driven disease emergence, with negative consequences for both production and biodiversity. Efforts to improve the management of emerging diseases of aquatic animals must include actions to reduce the rate of disease emergence, enhance disease detection and reporting, and improve responses to prevent disease spread. The rate of disease emergence can be reduced by understanding the underpinning mechanisms and developing measures to mitigate them. The three principal mechanisms of disease emergence, namely, host switching, decreased host immunocompetence and increased pathogen virulence, have many drivers. The most important of these drivers are those that expose susceptible hosts to novel pathogens (e.g. the introduction of non-native hosts, translocation of pathogens, and increased interaction between wild and farmed populations), followed by host switching. Exposure to wild populations can be reduced through infrastructure and management measures to reduce escapes or exclude wild animals (e.g. barrier nets, filtration and closed-confinement technology). A high standard of health management ensures immunocompetence and resistance to putative new pathogens and strains, and thus reduces the rate of emergence. Appropriate site selection and husbandry can reduce the likelihood of pathogens developing increased virulence by preventing their continuous cycling in geographically or temporally linked populations. The under-reporting of emerging aquatic animal diseases constrains appropriate investigation and timely response. At the producer level, employing information and communications technology (e.g. smartphone applications and Cloud computing) to collect and manage data, coupled with a farmer-centric approach to surveillance, could improve reporting. In addition, reporting behaviours must be understood and disincentives mitigated. At the international level, improving the reporting of emerging diseases to the World Organisation for Animal Health allows Member Countries to implement appropriate measures to reduce transboundary spread. Reporting would be incentivised if the global response included the provision of support to low-income countries to, in the short term, control a reported emerging disease, and, in the longer term, develop aquatic animal health services. Early detection and reporting of emerging diseases are only of benefit if Competent Authorities' responses prevent disease spread. Effective responses to emerging diseases are challenging because basic information and tools are often lacking. Consequently, responses are likely to be sub-optimal unless contingency plans have been developed and tested, and decision-making arrangements have been well established.

Sharing responsibility between public and private sectors for the management of aquatic emergency animal diseases

Aquatic animal disease outbreaks affect both the public (represented by the government) and the private sector (represented by the aquaculture and fisheries industry). However, all too often, the responsibilities and costs of responding to an outbreak may not be shared. Without a mechanism for public and private sectors to work together, the outcomes of an emergency response may not be ideal, or of common benefit to all potentially affected parties. In Australia, a mechanism is being developed for public and private sectors to share the responsibilities and costs of responding to aquatic animal disease outbreaks, through an industry- government aquatic emergency animal disease response agreement. The agreement provides an approach for both public and private sectors to share the responsibilities and costs of responding to a disease outbreak and to coordinate disease prevention activities to reduce their shared risk. The key elements of the agreement include provisions to incentivise faster notification of disease outbreaks, facilitate a faster response, share decision-making and costs (including compensation for affected businesses), clarify the responsibilities of all parties and, most importantly, strengthen risk mitigation activities. This paper describes how the draft agreement has been developed among 18 industry and government parties, how key elements of the agreement may contribute to improved aquatic animal health outcomes, and the principles which could be applied by other OIE Member Countries.

The impact of local control on overall survival after stereotactic body radiotherapy for liver and lung metastases from colorectal cancer: a combined analysis of 388 patients with 500 metastases

BACKGROUND

The aim of this analysis was to model the effect of local control (LC) on overall survival (OS) in patients treated with stereotactic body radiotherapy (SBRT) for liver or lung metastases from colorectal cancer.

METHODS

The analysis is based on pooled data from two retrospective SBRT databases for pulmonary and hepatic metastases from 27 centers from Germany and Switzerland. Only patients with metastases from colorectal cancer were considered to avoid histology as a confounding factor. An illness-death model was employed to model the relationship between LC and OS.

RESULTS

Three hundred eighty-eight patients with 500 metastatic lesions (lung n = 209, liver n = 291) were included and analyzed. Median follow-up time for local recurrence assessment was 12.1 months. Ninety-nine patients with 112 lesions experienced local failure. Seventy-one of these patients died after local failure. Median survival time was 27.9 months in all patients and 25.4 months versus 30.6 months in patients with and without local failure after SBRT. The baseline risk of death after local failure exceeds the baseline risk of death without local failure at 10 months indicating better survival with LC.

CONCLUSION

In CRC patients with lung or liver metastases, our findings suggest improved long-term OS by achieving metastatic disease control using SBRT in patients with a projected OS estimate of > 12 months.

Nomogram based overall survival prediction in stereotactic body radiotherapy for oligo-metastatic lung disease

BACKGROUND

Radical local treatment of pulmonary metastases is practiced with increasing frequency due to acknowledgment and better understanding of oligo-metastatic disease. This study aimed to develop a nomogram predicting overall survival (OS) after stereotactic body radiotherapy (SBRT) for pulmonary metastases.

PATIENTS AND METHODS

A multi-institutional database of 670 patients treated with SBRT for pulmonary metastases was used as training cohort. Cox regression analysis with bidirectional variable elimination was performed to identify factors to be included into the nomogram model to predict 2-year OS. The calibration rate of the nomogram was assessed by plotting the actual Kaplan-Meier 2-year OS against the nomogram predicted survival. The nomogram was externally validated using two separate monocentric databases of 145 and 92 patients treated with SBRT for pulmonary metastases.

RESULTS

The median follow up of the trainings cohort was 14.3months, the 2-year and 5-year OS was 52.6% and 23.7%, respectively. Karnofsky performance index, type of the primary tumor, control of the primary tumor, maximum diameter of the largest treated metastasis and number of metastases (1 versus >1) were significant prognostic factors in the Cox model (all p<0.05). The calculated concordance-index for the nomogram was 0.73 (concordance indexes of all prognostic factors between 0.54 and 0.6). Based on the nomogram the training cohort was divided into 4 groups and 2-year OS ranged between 24.2% and 76.1% (predicted OS between 30.2% and 78.4%). The nomogram discriminated between risk groups in the two validation cohorts (concordance index 0.68 and 0.67).

CONCLUSIONS

A nomogram for prediction of OS after SBRT for pulmonary metastases was generated and externally validated. This tool might be helpful for interdisciplinary discussion and evaluation of local and systemic treatment options in the oligo-metastatic setting.

KEY MESSAGE

A nomogram for prediction of overall survival after stereotactic body radiotherapy (SBRT) for pulmonary metastases was developed and externally validated. This tool might be helpful for interdisciplinary discussion and evaluation of local and systemic treatment options in the oligo-metastatic setting.

Using the Neptune project to benefit Australian aquatic animal health research

Diseases of aquatic animals have had, and continue to have, a significant impact on aquatic animal health. In Australia, where fisheries and aquaculture are important industries, aquatic species have been subject to serious disease outbreaks, including pilchard herpesvirus, the cause of one of the largest wild fish kills ever recorded. At the same time, there is a consensus that Australia's parasite fauna are largely unknown, and that aquatic animal health information is difficult to access. Managing aquatic animal diseases is challenging because they may be entirely new, their hosts may be new to aquaculture, and specialist expertise and basic diagnostic tools may be lacking or absent. The Neptune project was created in response to these challenges, and it aims to increase awareness of aquatic animal diseases, improve disease management, and promote communication between aquatic animal health professionals in Australia. The project consists of an online database, a digital microscopy platform containing a whole-slide image library, a community space, and online communications technology. The database contains aquatic animal health information from published papers, government reports, and other sources, while the library contains slides of key diseases both endemic and exotic to Australia. These assets make Neptune a powerful resource for researchers, students, and biosecurity officials.

Survivin, a target to modulate the radiosensitivity of Ewing's sarcoma

BACKGROUND AND PURPOSE

Radiotherapy constitutes an essential element in the multimodal therapy of Ewing's sarcoma. Compared to other sarcomas, Ewing tumors normally show a good response to radiotherapy. However, there are consistently tumors with a radioresistant phenotype, and the underlying mechanisms are not known in detail. Here we investigated the association between survivin protein expression and the radiosensitivity of Ewing's sarcoma in vitro.

MATERIAL AND METHODS

An siRNA-based knockdown approach was used to investigate the influence of survivin expression on cell proliferation, double-strand break (DSB) induction and repair, apoptosis and colony-forming ability in four Ewing's sarcoma cell lines with and without irradiation.

RESULTS

Survivin protein and mRNA were upregulated in all cell lines tested in a dose-dependent manner. As a result of survivin knockdown, STA-ET-1 cells showed reduced cell proliferation, an increased number of radiation-induced DSBs, and reduced repair. Apoptosis was increased by knockdown alone and increased further in combination with irradiation. Colony formation was significantly reduced by survivin knockdown in combination with irradiation.

CONCLUSION

Survivin is a radiation-inducible protein in Ewing's sarcoma and its down-regulation sensitizes cells toward irradiation. Survivin knockdown in combination with radiation inhibits cell proliferation, repair, and colony formation significantly and increases apoptosis more than each single treatment alone. This might open new perspectives in the radiation treatment of Ewing's sarcoma.

National aquatic animal health plans: the Australian experience

Following a major pilchard (Sardinops sagax) mortality event in 1995, Australia recognised the need for a national approach to aquatic animal health, particularly with respectto disease response. Cooperation between industry and government led to the development of AQUAPLAN, Australia's National Strategic Plan for Aquatic Animal Health. Under AQUAPLAN, institutional arrangements for the national technical response to aquatic animal health emergencies were developed based on existing arrangements for terrestrial animal health. The number and range of Australian Aquatic Veterinary Emergency Plan (AQUAVETPLAN) manuals are rising steadily; these are manuals that outline Australia's approach to national disease preparedness and propose the technical response and control strategies to be activated. Additional resources include standard diagnostic techniques and a disease field identification guide. Simulation exercises provide training to respond to aquatic emergency animal disease events. While resource issues and addressing governance remain priorities for the further implementation of AQUAPLAN, the highest priority is the development of a formal arrangement between governments and private sectors on the response to an aquatic emergency animal disease event.

[Stereotactic body radiotherapy (SBRT) -- an overview under special consideration of SBRT and LITT in the therapy of liver metastases]

Stereotactic body radiotherapy (SBRT) is a high dose radiotherapy, the radiation dose is applicated one-time or in a few fractions exactly to the tumor or metastases under maximal separation from the normal tissue. Because of this a major expenditure of medical and technical efforts are necessary, a detailed description of the proceedings is following in the methodic part of this article. Indications of SBRT are especially medical irresectable lung tumors of early stages, primary liver/biliary tumors and pulmonary or liver metastases if there is an oncological benefit for the patients. The side effects are moderate, the local tumor control rate is between 78 to 100 %. Depending on the primary tumor the overall survival is prolonged statistically significant. In the Klinikum Krefeld indications of SBRT vs chemotherapy, LITT or resection are discussed by an interdisciplinary conference of gastroenterologists/oncologists, radiologists, radiooncologists and surgeons. An example of LITT will be shown also.

Effects of the gill monogenean Zeuxapta seriolae (Meserve, 1938) and treatment with hydrogen peroxide on pathophysiology of kingfish, Seriola lalandi Valenciennes, 1833

Infections by the gill fluke Zeuxapta seriolae are a serious concern for sea cage aquaculture of kingfish, Seriola lalandi. The present study aimed to determine the pathophysiological effects of a progressive infection with Z. seriolae and the effects of treatment with hydrogen peroxide. For the progression of infection study, infected fish were taken from a sea cage farm, treated to remove parasites and then infected by cohabitation with heavily infected fish. Samples were taken at 2-week intervals for 8 weeks. Infection intensity peaked at 4 weeks post-infection (mean intensity 565.9) and the number of mature worms (2 mm fixed length or larger) peaked at 6 weeks post-infection. Attachment of Z. seriolae appeared to cause little localized pathology; however, the occurrence of hyperplastic lamellae increased as the infection progressed. Haemoglobin concentrations were negatively correlated with Z. seriolae intensity and were lower than controls at 4 weeks (35.8% decrease) and 6 weeks (57.4% decrease) post-infection. Blood lactate concentration and plasma osmolality increased throughout the course of infection. For the effect of treatment experiment, groups of infected and non-infected fish were sampled either before or after treatment with hydrogen peroxide. Treated fish from both infected and uninfected groups had increased plasma lactate, osmolality and pH compared with pre-treatment groups. Treatment with hydrogen peroxide appeared to have acute effects on fish health but the magnitude (e.g. lactate, osmolality) and extent of the effects (e.g. haemoglobin) was much less than that caused by chronic infection with Z. seriolae.

Effects of temperature, salinity, desiccation and chemical treatments on egg embryonation and hatching success of Benedenia seriolae (Monogenea: Capsalidae), a parasite of farmed Seriola spp

The effects of temperature and salinity on the embryonation period and hatching success of eggs of Benedenia seriolae were investigated. Temperature strongly influenced embryonation period; eggs first hatched 5 days after laying at 28 degrees C and 16 days after laying at 14 degrees C. The relationship between temperature and embryonation period is described by quadratic regression equations for time to first and last hatching. Hatching success was >70% for B. seriolae eggs incubated at temperatures from 14 to 28 degrees C. However, no B. seriolae eggs embryonated and hatched at 30 degrees C and <2% of eggs hatched when incubated at 24 degrees C after transfer to 30 degrees C for 48 h. Embryonation period was similar for eggs incubated in sea water at 25, 30 and 35 per thousand salinity, but increased for eggs incubated at higher or lower salinities. When incubated at salinities ranging from 25 to 45 per thousand, more than 70% of B. seriolae eggs embryonated and hatched. Hatching success was lower at 20 and 50 per thousand salinity and few or no eggs hatched at 10 and 15 per thousand. Hatching of B. seriolae eggs can be prevented by desiccation for 3 min, by immersion in water at 50 degrees C for 30 s or by treatment with 25% ethanol for 3 min.

Migration, site-specificity and development of Benedenia lutjani (Monogenea: Capsalidae) on the surface of its host, Lutjanus carponotatus (Pisces: Lutjanidae)

Life-history attributes of the capsalid monogenean Benedenia lutjani, a parasite of Lutjanus carponotatus from the Great Barrier Reef, Queensland, Australia, were investigated from experimental infections. Oncomiracidia of B. lutjani invaded and attached at any site on the fish, but more commonly invaded body surfaces. Immature specimens then migrated to the pelvic fins. Development of the reproductive organs of B. lutjani corresponded with migratory movements on the host. Parasite aggregation on the pelvic fins coincided with the development of functional male reproductive organs and some protandrous worms that possessed a vagina appeared to be inseminated. Migration to, and aggregation on, the branchiostegal membranes (membranous folds posterior to the opercula) coincided with the onset of sexual maturity and commencement of egg production by parasites. The rate of parasite development and the timing of migratory events on the host were influenced by water temperature. All specimens of B. lutjani reached sexual maturity between 12 and 14 days p.i. at 24 degrees C and between 8 and 10 days p.i. at 27 degrees C. Anterior hamuli grew continually during a 16-day experiment at 27 degrees C and 25-day experiment at 23 degrees C and their length appeared to provide a suitable index to estimate parasite age. The possible adaptive significance of the migratory behaviour, site-specificity and its link with changes in parasite development are discussed.

Experimental susceptibility of some reef fish species to Benedenia lutjani (Monogenea: Capsalidae), a parasite of Lutjanus carponotatus (Pisces: Lutjanidae)

The susceptibility of species of lutjanid, lethrinid and serranid fish to infection by either larval or post-larval (juvenile and adult) specimens of the capsalid monogenean Benedenia lutjani Whittington and Kearn (1993) was examined experimentally. Four species of lutjanids became infected when exposed to larvae of B. lutjani, but three species of lethrinids and four species of serranids were not susceptible to larvae under the same conditions. Variability in the intensity of infection by larvae occurred within and between lutjanid species. Few post-larval specimens of B. lutjani transferred between individuals of the specific host Lutjanus carponotatus (Richardson 1842) in 60-l aquaria and none transferred between specimens of L. carponotatus in a 7,500-1 concrete tank. These results indicate that transfer of post-larval B. lutjani between individuals of the specific host is unlikely to occur in the wild. Other lutjanid species did not become infected when exposed to specimens of L. carponotatus infected heavily by post-larval B. lutjani, but two lethrinid species were susceptible to infection under the same conditions. These data indicate that different factors may mediate host-specificity for larval and post-larval B. lutjani.

Gyrodactylus anguillae (Monogenea: Gyrodactylidae) from anguillid eels (Anguilla australis and Anguilla reinhardtii) in Australia: a native or an exotic?

A species of Gyrodactylus collected from 2 species of anguillid eels (Anguilla australis Richardson, 1841 and Anguilla reinhardtii Steindachner, 1867) from Australia is identified as Gyrodactylus anguillae Ergens, 1960. The morphology of sclerites of G. anguillae specimens from Australia is in accordance with previous descriptions of specimens collected from A. anguilla (Linnaeus, 1758) from Europe and A. anguilla imported into Japan. Gyrodactylus anguillae was previously thought to be a parasite specific to A. anguilla, an eel that is native to freshwater catchments throughout Europe. Information on eel translocations and host and parasite biology is reviewed and it is hypothesized that G. anguillae is a naturally occurring parasite in Australia and not an introduction.

Three new species of Polyclithrum Rogers, 1967 (Gyrodactylidae: Monogenea) from mugilid fishes from Australia and Brazil, with a redescription of P. mugilini Rogers, 1967

Polyclithrum mugilini Rogers, 1967, a parasite of Mugil cephalus Linnaeus, is redescribed from type-material from Lake Seminole, Georgia, USA. Three new species of Polyclithrum Rogers, 1967 are also described: P. alberti n. sp. from M. cephalus from the Albert River, Queensland, Australia; P. boegeri n. sp. from M. platanus Günther from Rio da Guarda, State of Rio de Janeiro, Brazil; and P. corallense n. sp. from M. cephalus from Heron Island, Great Barrier Reef, Australia. The four species can be distinguished by the size and shape of haptoral sclerites, but in particular by accessory bar number 3, the dorsal bar, the marginal hooks and the hamulus point to shaft angle. The validity of Micropolyclithrum parvum Skinner, 1975, a parasite of M. cephalus in Biscayne Bay, Florida, is discussed, and a key to the species of Polyclithrum is presented.

The uterine epithelium of Gyrodactylus kobayashii (Monogenea: Gyrodactylidae): ultrastructure of basal matrices, cytoplasmic membranes and the birth plug, and comparison with other reproductive epithelia

Ultrastructural details of reproductive epithelia in the viviparous monogenean Gyrodactylus kobayashii are described. Specimens of G. kobayashii were fixed for transmission electron microscopy in glutaraldehyde in sodium cacodylate buffer followed by either 1% aqueous osmium tetroxide or 1% aqueous osmium tetroxide reduced with 1.5% potassium ferricyanide. All reproductive epithelia are underlain by a fibrillar basal matrix. The uterine basal matrix is electron-opaque after potassium ferricyanide reduced osmium tetroxide fixation suggesting the presence of carbohydrate-containing materials. With potassium ferricyanide reduced osmium tetroxide fixation, two prominent membrane systems were distinguished in the uterine epithelium. Basal invaginations are short infoldings of the basal membrane. The basal invaginations are common in other reproductive epithelia and tegument and probably enhance transport of materials by these epithelia. Laminated membranes are membrane stacks, resembling endoplasmic reticulum stacks. These membranes were abundant at the apical membrane. The birth plug is a solid cytoplasmic layer, lacking a lumen, and rich in cytoplasmic vesicles. This layer connects the tegument and the uterine epithelium.

Concurrent invaders--four exotic species of Monogenea now established on exotic freshwater fishes in Australia

Four species of exotic monogeneans are reported from five species of exotic freshwater fish in Australia: Gytrodactylus bullatarudis from Poecilia reticulata and Xiphophorus helleri in Queensland; Gyrodactylus macracanthus from Misgurnus anguillicaudatus in the Australian Capital Territory; Dactylogyrus extensus from Cyprinus carpio in the Australian Capital Territory; and Dactylogyrus anchoratus from Carassius auratus in the Australian Capital Territory. This is the first published record of described species of monogeneans of the genus Dactylogyrus or Gyrodactylus from Australia and the first report of parasites of M. anguillicaudatus in Australia. The establishment of exotic monogenean populations on Australian native fishes via host-switching is considered less likely than for other parasitic groups due to the generally high host-specificity of monogeneans, combined with the phylogenetic dissimilarity of native and exotic fishes. Similar establishments have occurred elsewhere, however, and the risk of these events increases with each new fish species introduction.

Chronic hepatitis C: the viral load per liver cell before treatment as a new marker to predict long-term response to IFN-alpha therapy

BACKGROUND/AIMS

So far, there are no reliable parameters that can predict the long-term sustained response to treatment with interferon-alpha in patients with chronic hepatitis C. In this study, we have developed a semi-quantitative method to determine the viral load per liver cell and have correlated this factor with the outcome of hepatitis C patients treated with interferon-alpha.

METHODS

Hepatitis C virus RNA levels were measured in serum, peripheral blood mononuclear cells and liver cells of randomly chosen hepatitis C patients before treatment with interferon-alpha (n=37). The number of cells present in the liver biopsies was determined by a polymerase chain reaction-based quantitation of the housekeeping gene beta-globin. The patients were divided into a responder ("R", n=15, 41%) and a non-responder ("NR", n=22, 59%) group, as defined by normal liver enzymes and negative hepatitis C virus-polymerase chain reaction 6 months after treatment.

RESULTS

Long-term sustained responders had a significantly lower viral load per liver cell (median: 5 vs. 650 copies/1000 liver cells, p-value: 0.0001), lower age (median: 32 vs. 54 years, p-value: 0.006) and lower percentage of geno- or serotype 1 (46% vs. 91%). Regarding viral load in serum and peripheral blood mononuclear cells, alanine aminotransferase levels, gamma-globulin levels and histological changes, no statistically significant differences were observed.

CONCLUSIONS

In chronic hepatitis C infection, a high viral load per liver cell represents a new marker to predict long-term response to therapy with IFN-alpha.

Variation in the egg cell forming region of Gyrodactylus kobayashii Hukuda, 1940 (Monogenea:Gyrodactylidae)

The egg cell forming region of Gyrodactylus kobayashii from goldfish (Carassius auratus) is a thin nucleated cytoplasmic layer surrounding the developing egg cell (= oocyte). The cytoplasm contains numerous elougate membranes. As parasites age, the egg cell forming region becomes electron lucent. The apical membrane of the egg cell forming region becomes disrupted in places. A basal matrix is indistinct in new-born and young worms, becoming more evident as worms grow older. Numerous pits (= basal pits) are found along the basal plasma membrane of worms with a mature male system. These pits appear to be stable components of the membrane and resemble hemidesmosomes. Basal pits were co-incident with sperm in the egg cell forming region in 3 of 5 worms examined. The function of the basal pits of G. kobayashii could not be determined. It is postulated, however, that they either assist sperm to traverse the egg cell forming region to fertilize the egg cell or stabilize the egg cell forming region against damage by sperm traversing this layer. The egg cell forming region encloses a large egg cell and 1 or more smaller differentiating egg cells. The ripening egg cell has a large nucleus and extensive cytoplasm. The cell has a thickened membrane. Large vacuoles and invaginations at the periphery of the egg cell appear to engulf cytoplasm of the egg cell forming region.

Hatching rhythms in the the capsalid monogeneans Benedenia lutjani from the skin and B. rohdei from the gills of Lutjanus carponotatus at Heron Island, Queensland, Australia

Spontaneous hatching of eggs of Benedenia lutjani and B. rohdei occurred after incubation for 4-6 days and 6-10 days, respectively, at a constant temperature in the range 22-28 degrees C when exposed to natural illumination or to alternating 12-h periods of light and darkness (LD12:12; light on, 06.00 h; light off, 18.00 h). Under these conditions, hatching of the eggs of both species was rhythmical, all larvae emerging only during periods of illumination. Hatching was not confined to particular times with the illuminated period. Evidence for an endogenous component to the rhythm was revealed by transfer of eggs from LD12:12 to continuous darkness (DD) near the end of the incubation period. Hatching, also occurred only during periods of illumination when eggs of each species were incubated under a DL12:12 regime (i.e. period of illumination 18.00 h to 06.0 h; period of darkness 06.00 h to 18.00 h). When the eggs of B. lutjani and B. rohdei were laid and incubated in DD or continuous illumination (LL), some degree of rhythmicity persisted, raising the possibility that the eggs inherit circadian rhythmicity from their parent. The hatching patterns of these 2 species of monogeneans are discussed in relation to host finding, host behaviour and limited observations on the behaviour of the oncomiracidia after hatching.

Interstitial pneumopathy after mantle field irradiation for Hodgkin's disease

This retrospective analysis was undertaken to determine the incidence of interstitial pneumopathy and the clinical course after mantle field irradiation for Hodgkin's disease focusing on the role of radio- and chemotherapy. 136 patients were evaluable, 40 having received radiotherapy only and 96 patients having received combined radio-chemotherapy. The median follow-up time was 21.5 months. The overall incidence was 19%; 4 patients died of severe interstitial pneumopathy and 3 died of simultaneous severe complications. The radiation dose was correlated with the incidence of interstitial pneumopathy (P = 0.0021).