Lesions caused by cardiovascular flukes (Digenea : Spirorchidae) in stranded green turtles (Chelonia mydas)

Evidence of infection with spirorchid flukes (Digenea: Spirorchidae) was sought at necropsy of 96 stranded green turtles, Chelonia mydas, that were examined during the course of a survey of marine turtle mortality in southeastern Queensland, Australia. Three species of spirorchid (Hapalotrema mehrai, H. postorchis, and Neospirorchis schistosomatoides) were identified. Severe disease due to spirorchid fluke infection (spirorchidiasis) was implicated as the principal cause of mortality in 10 turtles (10%), and appeared to be one of multiple severe problems in an additional 29 turtles (30%). Although flukes were observed in only 45% of stranded C. mydas in this study, presumed spirorchid fluke infection was diagnosed in an additional 53% of turtles, based principally on characteristic necropsy lesions and to a lesser extent on the histopathological detection of spirorchid eggs. Characteristic necropsy lesions included miliary spirorchid egg granulomas, which were observed most readily on serosal surfaces, particularly of the small intestine. Cardiovascular lesions included mural endocarditis, arteritis, and thrombosis, frequently accompanied by aneurysm formation. Resolution of thrombi was observed to occur via a combination of granuloma formation about indigestible components (spirorchid fluke egg shells) and exteriorization through the vessel wall, which resulted in granulomatous nodules on the adventitial surface. Septic aortic thrombosis complicated by disseminated bacterial infection, observed in five turtles, was recorded for the first time. Egg granulomas were ubiquitous in turtle tissues throughout this study. Although they generally appeared to be mild or incidental lesions, they were occasionally associated with severe multifocal granulomatous pneumonia or meningitis.

From sabotage to camouflage: viral evasion of cytotoxic T lymphocyte and natural killer cell-mediated immunity

The outcome of a virus infection is strongly influenced by interactions between host immune defences and virus 'anti-defence' mechanisms. For many viruses, their continued survival depends on, the speed of their attach: their capacity to replicate and transmit to uninfected hosts prior to their elimination by an effective immune response. In contrast, the success of persistent viruses lies in their capacity for immunological subterfuge: the evasion of host defence mechanisms by either mutation (covered elsewhere in this issue, by Gould and Bangham, pp. 321-328) or interference with the action of host cellular proteins that are important components of the immune response. This review will focus on the strategies employed by persistent viruses against two formidable host defences against virus infection: the CD8+ cytotoxic T lymphocyte (CTL) and natural killer (NK) cell responses.

Achieving the millennium development goals for health - Cost effectiveness analysis of strategies for. maternal and neonatal health in developing countries

Objective To determine the costs and benefits of interventions for maternal and newborn health to assess the appropriateness of current strategies and guide future plans to attain the millennium development goals. Design Cost effectiveness analysis. Setting Two regions classified by the World Health Organization according to their epidemiological grouping: Afr-E, those countries in sub-Saharan Africa with very high adult and high child mortality, and Sear-D, comprising countries in South East Asia with high adult and high child mortality. Data sources Effectiveness data from several sources, including trials, observational studies, and expert opinion. For resource inputs, quantifies came from WHO guidelines, literature, and expert opinion, and prices from the WHO choosing interventions that are cost effective database. Main outcome measures Cost per disability adjusted life year (DALY) averted in year 2000 international dollars. Results The most cost effective mix of interventions was similar in Afr-E and Sear-D. These were the community based newborn care package, followed by antenatal care (tetanus toxoid, screening for pre-eclampsia, screening and treatment of asymptomatic bacteriuria and syphilis); skilled attendance at birth, offering first level maternal and neonatal care around childbirth; and emergency obstetric and neonatal care around and after birth. Screening and treatment of maternal syphilis, community based management of neonatal pneumonia, and steroids given during the antenatal period were relatively less cost effective in Sear-D. Scaling up all of the included interventions to 95% coverage would halve neonatal and maternal deaths. Conclusion Preventive interventions at the community level for newborn babies and at the primary care level for mothers and newborn babies are extremely cost effective, but the millennium development goals for maternal and child health will not be achieved without universal access to clinical services as well.

Drug targets and mechanisms of resistance in the anaerobic protozoa

The anaerobic protozoa Giardia duodenalis, Trichomonas vaginalis, and Entamoeba histolytica infect up to a billion people each year. G. duodenalis and E. histolytica are primarily pathogens of the intestinal tract, although E. histolytica can form abscesses and invade other organs, where it can be fatal if left untreated. T. vaginalis infection is a sexually transmitted infection causing vaginitis and acute inflammatory disease of the genital mucosa. T. vaginalis has also been reported in the urinary tract fallopian tubes, and pelvis and can cause pneumonia, bronchitis, and oral lesions. Respiratory infections can be acquired perinatally. T. vaginalis infections have been associated with preterm delivery, low birth weight, and increased mortality as well as predisposing to human immunodeficiency virus infection, AIDS, and cervical cancer. All three organisms lack mitochondria and are susceptible to the nitroimidazole metronidazole because of similar low-redox-potential anaerobic metabolic pathways. Resistance to metronidazole and other drugs has been observed clinically and in the laboratory. Laboratory studies have identified the enzyme that activates metronidazole, pyruvate:ferredoxin oxidoreductase, to its nitroso form and distinct mechanisms of decreasing drug susceptibility that are induced in each organism. Although the nitroimidazoles have been the drug family of choice for treating the anaerobic protozoa, G. duodenalis is less susceptible to other antiparasitic drugs, such as furazolidone, albendazole, and quinacrine. Resistance has been demonstrated for each agent and the mechanism of resistance has been investigated. Metronidazole resistance in T. vaginalis is well documented, and the principal mechanisms have been defined Bypass metabolism, such as alternative oxidoreductases, have been discovered in both organisms. Aerobic versus anaerobic resistance in T. vaginalis is discussed. Mechanisms of metronidazole resistance in E. histolytica have recently been investigated ruing laboratory-induced resistant isolates. Instead of downregulation of the pyruvate:ferredoxin oxidoreductase and ferredoxin pathway as seen in G. duodenalis and T. vaginalis, E. histolytica induces oxidative stress mechanisms, including superoxide dismutase and peroxiredoxin. The review examines the value of investigating both clinical and laboratory-induced syngeneic drug-resistant isolates and dissection of the complementary data obtained. Comparison of resistance mechanisms in anaerobic bacteria and the parasitic protozoa is discussed as well as the value of studies of the epidemiology of resistance.

The natural history of Hendra and Nipah viruses

Pteropid bats (flying foxes), species of which are the probable natural host of both Hendra and Nipah viruses, occur in overlapping populations from India to Australia. Ecological changes associated with land use and with animal husbandry practices appear most likely to be associated with the emergence of these two agents. (C) 2001 Editions scientifiques et medicales Elsevier SAS.

Community-acquired Klebsiella pneumoniae bacteremia: Global differences in clinical patterns

We initiated a worldwide collaborative study, including 455 episodes of bacteremia, to elucidate the clinical patterns of Klebsiella pneumoniae. Historically, community-acquired pneumonia has been consistently associated with K. pneumoniae. Only four cases of community-acquired bacteremic K. pneumoniae pneumonia were seen in the 2-year study period in the United States, Argentina, Europe, or Australia; none were in alcoholics. In contrast, 53 cases of bacteremic K. pneumoniae pneumonia were observed in South Africa and Taiwan, where an association with alcoholism persisted (p=0.007). Twenty-five cases of a distinctive syndrome consisting of K. pneumoniae bacteremia in conjunction with community-acquired liver abscess, meningitis, or endophthalmitis were observed. A distinctive form of K. pneumoniae infection, often causing liver abscess, was identified, almost exclusively in Taiwan.

Keratinocyte Growth factor (KGF) in hematology and oncology

Keratinocyte Growth factor (KGF) is an epithelial cell growth factor of the fibroblast growth factor family and is produced by fibroblasts and microvascular endothelium in response to proinflammatory cytokines and steroid hormones. KGF is a heparin binding growth factor that exerts effects on epithelial cells in a paracrine fashion through interaction with KGF receptors. Preclinical data has demonstrated that KGF can prevent lung and gastrointestinal toxicity following chemotherapy and radiation and preliminary clinical data in the later setting supports these findings. In the experimental allogeneic bone marrow transplant scenario KGF has shown significant ability to prevent graft-versus-host disease by maintaining gastrointestinal tract integrity and acting as a cytokine shield to prevent subsequent proinflammatory cytokine generation. Within this setting KGF has also shown an ability to prevent experimental idiopathic pneumonia syndrome by stimulating production of surfactant protein A, promoting alveolar epithelialization and attenuating immune-mediated injury. Perhaps most unexpectantly, KGF appears able to maintain thymic function during allogeneic stern cell transplantation and so promote T cell engraftment and reconstitution. These data suggest that KGF will find a therapeutic role in the prevention of epithelial toxicity following intensive chemotherapy and radiotherapy protocols and in allogeneic stem cell transplantation.

Incidence, characteristics, and predictive factors for dysphagia after pediatric traumatic brain injury

Objective: (1) To establish an incidence figure for dysphagia in a population of pediatric traumatic brain injury (TBI) cases; (2) to provide descriptive data on the admitting characteristics, patterns of resolution, and outcomes of children with and without dysphagia after TBI; and (3) to identify any factors present at admission that may predict dysphagia. Participants: A total of 1, 145 children consecutively admitted to an acute care setting for traumatic brain injury between July 1995 and July 2000. Main outcome measure: Medical parameters relating to dysphagia based on medical chart review. Results: (1) Dysphagia incidence figure of 5.3% across all pediatric head injury admissions. Incidence figures of 68% for severe TBI, 15% for moderate TBI, and only 1% for mild brain injury. (2) Statistically significant differences were found between the dysphagic and nondysphagic subgroups on the variables of length of stay, length of ventilation, Glasgow Coma Scale (GCS), computed tomography classification, duration of speech pathology intervention, supplemental feeding duration, duration until initiation of oral intake (DIOF), duration to total oral intake (DTOF), and period of time from the initiation of intake until achievement of total oral intake (DI-TOF). (3) Significant predictive factors for dysphagia included GCS < 8.5 and a ventilation period in excess of 1.5 days. Conclusion: The provision of incidence data and predictive factors for dysphagia will enable clinicians in acute care settings to allocate resources necessary to deal with the predicted number of dysphagia cases in a pediatric population, and assist in predicting patients who are at risk for dysphagia following TBI. Early detection of patients with swallowing dysfunction will be aided by these data, in turn helping to facilitate effective medical and speech pathology intervention via assisting the reduction of medical complications such as aspiration pneumonia.

Toxoplasmosis in Indo-Pacific humpbacked dolphins (Sousa chinensis), from Queensland

Objective To describe the clinical signs, gross pathology, serology, bacteriology, histopathology, electron microscopy and immunohistochemistry findings associated with toxoplasmosis in four Indo-Pacific humpbacked dolphins (Sousa chinensis) that stranded in Queensland in 2000 and 2001. Design Clinical assessment, gross necropsy, and laboratory examinations. Procedure Necropsies were performed on four S chinensis to determine cause of death. Laboratory tests including serology, bacteriology, histopathology and transmission electron microscopy were done on the four dolphins. Immunohistochemistry was done on the brain, heart, liver, lung, spleen and adrenal gland from various dolphins to detect Toxoplasma gondii antigens. Results Necropsies showed all of four S chinensis that stranded in Queensland in 2000 and 2001 had evidence of predatory shark attack and three were extremely emaciated. Histopathological examinations showed all four dolphins had toxoplasmosis with tissue cysts resembling T gondii in the brain. Tachyzoite stages of T gondii were detected in the lungs, heart, liver, spleen and adrenal gland, variously of all four dolphins. Electron microscopy studies and immunohistochemistry confirmed the tissues cysts were those of T gondii. All four dolphins also had intercurrent disease including pneumonia, three had peritonitis and one had pancreatitis. Conclusion Four S chinensis necropsied in Queensland in 2000 and 2001 were found to be infected with toxoplasmosis. It is uncertain how these dolphins became infected and further studies are needed to determine how S chinensis acquire toxoplasmosis. All four dolphins stranded after periods of heavy rainfall, and coastal freshwater runoff may be a risk factor for T gondii infection in S chinensis. This disease should be of concern to wildlife managers since S chinensis is a rare species and its numbers appear to be declining.

The morbidity of Guillain-Barré syndrome admitted to the intensive care unit

Patients with severe forms of Guillain-Barré syndrome (GBS) require intensive care. Specific treatment, catheterization, and devices may increase morbidity in the intensive care unit (ICU). To understand the spectrum of morbidity associated with ICU care, the authors studied 114 patients with GBS. Major morbidity occurred in 60% of patients. Complications were uncommon if ICU stay was less than 3 weeks. Respiratory complications such as pneumonia and tracheobronchitis occurred in half of the patients and were linked to mechanical ventilation. Systemic infection occurred in one-fifth of patients and was more frequent with increasing duration of ICU admission. Direct complications of treatment and invasive procedures occurred infrequently. Life-threatening complications such as gastrointestinal bleeding and pulmonary embolism were very uncommon. Pulmonary morbidity predominates in patients with severe GBS admitted to the ICU. Attention to management of mechanical ventilation and weaning is important to minimize this complication of GBS. Other causes of morbidity in a tertiary center ICU are uncommon.