Impact and process evaluation of a primary-school Food Education and Sustainability Training (FEAST) program in 10-12-year-old children in Australia: pragmatic cluster non-randomized controlled trial.

BACKGROUND: Environmentally sustainable food initiatives accompanying nutrition education, such as the Food Education and Sustainability Training (FEAST) program, have gained traction in school settings. The aim of this trial was to conduct an impact and process evaluation of FEAST, to evaluate its effect on children's fruit and vegetable (F&V) intakes, and secondary outcomes: F&V variety consumed, nutrition knowledge, food preparation/cooking skills, self-efficacy and behaviours, food waste knowledge and behaviours, and food production knowledge. METHODS: FEAST was a 10-week curriculum-aligned program, designed to educate children about healthy eating, food waste, and sustainability, while teaching cooking skills. It was implemented by classroom teachers, face-to-face and online, during COVID-19 school closures, in Australia in 2021. A custom designed survey was used to collect baseline and post-intervention data from students. Generalised linear mixed models (GLMM) estimated group differences in pre-post changes for primary and secondary outcomes. Surveys were also administered to students and teachers to evaluate intervention implementation. RESULTS: Twenty schools participated and self-selected to be either intervention schools (n = 10) or wait-list control (WLC) schools (n = 10). A total of 977, 5th and 6th grade children participated in the trial with a mean age of 11.1 years (SD ± 0.7). The FEAST intervention, compared to WLC, did not result in significant increases in primary outcomes nor secondary outcomes. The process evaluation revealed FEAST was well-received by students and teachers, but COVID-19 school closures hindered implementation fidelity with a less intense program delivered under the constraints of pandemic lockdowns. CONCLUSIONS: This is the first cluster non-randomized controlled trial designed to independently evaluate FEAST in the primary-school setting. No evidence was found for improved F&V intakes in children, nor secondary outcomes. However, the positive process evaluation results suggest that further trials of the program are warranted. If implemented as originally designed (pre-pandemic), with increased duration and complemented by supporting school policies, such programs have the potential to improve children's daily F&V intakes, cooking skills and food waste behaviours. This would support the Australian curriculum and contribute to: health promotion within schools and sustainable schools initiatives, the national agenda to reduce food waste and sustainable development goals. AUSTRALIAN AND NEW ZEALAND CLINICAL TRIALS REGISTRY: [ACTRN12620001347954]- Registered prospectively on 14/12/2020.

Evaluating OzHarvest's primary-school Food Education and Sustainability Training (FEAST) program in 10-12-year-old children in Australia: protocol for a pragmatic cluster non-randomized controlled trial.

BACKGROUND: The promotion of healthy eating is a public health priority. Poor dietary behaviours, including low fruit and vegetable (F&V) consumption are of particular concern among children. Novel nutrition promotion strategies are needed to improve F&V consumption. Sustainability education could be used to support nutrition education within the school context. The purpose of this paper is to report the protocol for impact and process evaluation of the school-based Food Education and Sustainability Training (FEAST) program, designed to educate children about sustainability, food waste and nutrition, using hands-on cooking activities. METHODS: A pragmatic, parallel, cluster non-randomized controlled trial with pre- and post-measures, will be implemented among 20 primary schools (10 intervention vs 10 wait-list-control) within NSW, Australia, involving children in Grades 5-6. FEAST is a curriculum-aligned program, delivered as a 1.5-h lesson/week, for a 10-week unit of inquiry, incorporating theory and cooking. FEAST was developed using theoretical frameworks which included Social Cognitive Theory and the Precede-Proceed Planning model. Primary outcomes include children's self-reported F&V intakes (serves/day). Food literacy constructs such as: nutrition knowledge, food preparation and cooking skills, self-efficacy and behaviours, food waste knowledge and behaviours and food production knowledge, will be assessed as secondary outcomes. Process evaluation will assess program reach, adoption, implementation, maintenance, satisfaction and perceived benefits by teachers and students. An online survey (including quantitative and qualitative questions) was developed for administration at baseline (impact evaluation) and immediately post-intervention (impact and process evaluation). Intervention effects on quantitative study outcomes will be estimated with ​generalised linear mixed models, including random effects and will follow the intention-to-treat principles. Open-ended questions embedded within the surveys will be analysed qualitatively using content and thematic analyses. DISCUSSION: Results from this trial will provide valuable information on the value of adding environmental sustainability strategies to nutrition education in schools. Results will inform the design of future research and programs focused on primary-school children's nutrition, sustainability-related behaviours and experiential school-based interventions. TRIAL REGISTRATION: Trial registered 14th December 2020 with the Australian and New Zealand Clinical Trials Registry ( ACTRN12620001347954 ).

Myenteric networks of interstitial cells of Cajal are reduced in horses with inflammatory bowel disease.

BACKGROUND: Inflammatory bowel disease (IBD) is a well-recognised but poorly understood disease complex in the horse. Clinical signs may vary but often include weight loss, diarrhoea and colic. The effect this disease process may have on the gastrointestinal pacemaker cells (the interstitial cells of Cajal), enteric neurons and glial cells has not been previously evaluated in the horse. OBJECTIVES: To compare the density of the interstitial cells of Cajal (ICC), enteric neurons and glial cells in horses with IBD to those of normal horses using immunohistochemical markers. STUDY DESIGN: Retrospective, quantitative immunohistochemical study. METHODS: Ileal samples were collected during post-mortem examinations from 14 horses with a clinical and histopathological diagnosis of IBD and from eight normal controls. All horses were Standardbreds 1-15 years of age. Six of the IBD cases had eosinophilic gastroenteritis (EG) while the remaining eight had granulomatous enteritis (GE). Tissue sections were labelled with anti-CD117 (c-Kit), anti-TMEM16 (TMEM16), anti-protein gene product (PGP9.5) and anti-glial fibrillary acidic protein (GFAP) using standard immunohistochemical labelling techniques. Image analysis was performed to quantify the presence of ICC (CD117, TMEM16) as well as neuronal (PGP9.5) and enteroglial (GFAP) networks. RESULTS: Interstitial cells of Cajal networks were significantly reduced in the myenteric plexus (MP) region in IBD horses compared with the controls for both markers (P<0.05). There was no significant difference in the density of the neuronal or glial cell markers between the two groups (P>0.05). MAIN LIMITATIONS: The number of horses included in the study. CONCLUSIONS: Disruption to ICC networks may contribute to the clinical signs of colic in some horses with IBD. Further studies are needed to establish the pathophysiological mechanisms involved and the functional effects of the reduced ICC networks.

Early detection of neutralizing antibodies to interferon-beta in multiple sclerosis patients: binding antibodies predict neutralizing antibody development.

BACKGROUND: Neutralizing antibodies (NAb) affect efficacy of interferon-beta (IFN-b) treatment in multiple sclerosis (MS) patients. NAbs evolve in up to 44% of treated patients, usually between 6-18 months on therapy. OBJECTIVES: To investigate whether early binding antibody (BAb) titers or different IFN-b biomarkers predict NAb evolution. METHODS: We included patients with MS or clinically isolated syndrome (CIS) receiving de novo IFN-b treatment in this prospective European multicenter study. Blood samples were collected at baseline, before and after the first IFN-b administration, and again after 3, 12 and 24 months on that therapy; for determination of NAbs, BAbs, gene expression of MxA and protein concentrations of MMP-9, TIMP-1, sTRAIL, CXCL-10 and CCL-2. RESULTS: We found that 22 of 164 (13.4%) patients developed NAbs during a median time of 23.8 months on IFN-b treatment. Of these patients, 78.9% were BAb-positive after 3 months. BAb titers ≥ 1:2400 predicted NAb evolution with a sensitivity of 74.7% and a specificity of 98.5%. Cross-sectionally, MxA levels were significantly diminished in the BAb/NAb-positive samples; similarly, CXCL-10 and sTRAIL concentrations in BAb/NAb-positive and BAb-positive/NAb-negative samples, respectively, were also diminished compared to BAb/NAb-negative samples. CONCLUSIONS: BAb titers reliably predict NAbs. CXCL-10 is a promising sensitive biomarker for IFN-b response and its abrogation by anti-IFN-b antibodies.

Microarray and cytokine analyses of field cases of pigs with diarrhoea.

This field study explored the cytokine expression in intestinal tissue and serum from 19 diarrhoeic and 9 healthy pigs in herds with a long-time history of Lawsonia intracellularis-infection. The disease, proliferative enteropathy (PE), is associated with diarrhoea and poor performance in growers and haemorrhagic diarrhoea and sudden death in finisher pigs, but the immunopathology is poorly understood. Histopathology, demonstration of L. intracellularis and porcine circovirus type 2 (PCV2) in intestinal tissue by PCR, and detection of serum antibodies to L. intracellularis, were performed. The presence of IL-1ß, IL-6, IL-10, IFN-α, IFN-γ, TNF-α and TGF-ß in sera was determined by immunoassays, and intestinal mRNA expression of these cytokines plus IL-12p40 was determined by qPCR. Intestinal specimens from pigs with intestinal adenomatosis (n=2), proliferative haemorrhagic enteropathy or swine dysentery (n=2), and controls (n=2) were analysed by a genome wide porcine microarray. The clinical signs of PE were not always supported by the subsequent analyses, and the presence of PCV2 may have contributed to an increased mRNA expression for IFN-γ in intestinal specimens from some pigs. The limited gene expression in the microarray analyses and the limited expression of cytokines in both sera and intestines, indicate that the immune response is poorly activated in the initial course of an infection with L. intracellularis. However, the gene encoding for insulin-like growth factor binding protein 3 (IGFBP-3) was up-regulated in two pigs with prominent mucosal proliferation.

Expression of serotonin and its 5-HT1A receptor in canine cutaneous mast cell tumours.

Mast cells of a number of different animal species have been reported to contain serotonin (5-hydroxytryptamine; 5-HT), a monoamine capable of numerous and complex actions, which may include an impact on tumour growth. Limited previous studies have suggested that normal or neoplastic canine mast cells do not express 5-HT. In the present study, canine cutaneous mast cell tumours (MCTs) of Patnaik histological grades I-III were investigated immunohistochemically for expression of 5-HT and its receptor (R) 5-HT1A. The proportion of positively labelled cells and the intensity of labelling of individual cells were determined. Both 5-HT and the 5-HT1A receptor were expressed by non-neoplastic dermal mast cells and neoplastic mast cells. More neoplastic mast cells expressed 5-HT than the 5-HT1AR. Poorly differentiated tumours expressed fewer of both molecules, but the better differentiated mast cells at the periphery of such lesions had more consistent 5-HT expression. 5-HT and the 5-HT1A receptor may be involved in the differentiation of canine MCTs and in the microvascular complications associated with these neoplasms.

Mice overexpressing murine oncostatin M (OSM) exhibit changes in hematopoietic and other organs that are distinct from those of mice overexpressing human OSM or bovine OSM.

Oncostatin M (OSM) and leukemia inhibitory factor (LIF) belong to the interleukin-6 family of cytokines. The authors' previous in vitro work demonstrated that in mouse cells mouse OSM (mOSM) signals through a heterodimeric receptor complex incorporating the mOSM-specific receptor mOSMRbeta while human OSM (hOSM) and bovine OSM (bOSM) use the mouse LIF receptor mLIFRbeta rather than mOSMRbeta. These in vitro data suggest that prior studies in mouse systems with hOSM or bOSM (the usual molecules used in early studies) reflect LIF rather than OSM biology. The current work assessed whether or not this divergence in actions among these three OSMs also occurs in vivo in mouse models. Adult female (C57BL/6J x DBA/2J) F(1) mice were engineered to stably overexpress mOSM, hOSM, or bOSM by retrovirus-mediated gene transfer (n = 10 or more per group). After 4 weeks, molecular and hematologic profiles and anatomic phenotypes in multiple organs were assessed by standard techniques. Animals overexpressing either hOSM or bOSM had an identical phenotype resembling that associated with LIF activation, including significant hematologic abnormalities (anemia, neutrophilia, lymphopenia, eosinopenia, and thrombocytosis); weight loss; profound enlargement (lymph node, spleen) and/or structural reorganization (lymph node, spleen, thymus) of lymphoid organs; and severe osteosclerosis. In contrast, mice overexpressing mOSM did not develop hematologic changes, weight loss, or osteosclerosis and exhibited more modest and anatomically distinct restructuring of lymphoid organs. These data indicate that activities imputed to OSM and the mOSMRbeta signaling pathway using in vitro and in vivo mouse experimental systems are unique to mOSM.

Persistent immune responses in late infection and after treatment in experimental Schistosoma bovis infections in goats.

This study explored host immune responses and their possible relationship to the anti-fecundity phenomenon in Schistosoma bovis-infected goats. The design comprised a primary infection with or without treatment at week (wk) 13, and with or without challenge at wk 36. Necropsy was performed at 36 or 52wk. Serum levels of anti-egg IgG, and anti-worm IgG and IgM, were measured by ELISA. In chronic infection, anti-worm antibodies stayed high, reflecting persisting worm burdens, whereas anti-egg IgG remained high despite minimized egg excretion. After treatment, anti-worm IgM and anti-egg IgG were minimized, but anti-worm IgG remained above the values of the uninfected controls. Histopathology showed lowered numbers of perioval granulomas in chronic infection and resolution of liver fibrosis with time, but intestinal lymphoplasmacytic perivasculitis and hepatic eosinophilic infiltrates were maintained at wk 52. Significant splenic plasmacytosis persisted after treatment. The results indicated that persistent immune responses, in chronically infected and in treated goats, may explain sustained worm fecundity depression at challenge infection.

Hepatic changes in congenital Schistosoma japonicum infections in pigs.

The inflammatory response in liver tissue from piglets congenitally infected with Schistosoma japonicum was examined at two different timepoints after infection. The piglets, which were the offspring of three sows infected with 9000 S. japonicum cercariae in the 10th week of gestation, were allocated into two groups (n=9 and 17) killed 5 or 11 weeks after birth, respectively. All piglets developed a low level infection,with no significant difference between the groups. Inflammatory lesions in the liver consisted mainly of granulomas in portal areas, often obliterating the portal veins, and frequently with central eggs or egg remnants. The granulomatous reaction consisted of epithelioid cells and occasional giant cells surrounded by layers of lymphocytes, eosinophils, plasma cells, and various amounts of collagen and fibroblasts. Mild to moderate infiltration of portal and septal connective tissue with eosinophils and lymphocytes was common, but the connective tissue was generally not increased. At the two timepoints, slight differences were observed in the numbers of eosinophils and lymphocytes in the granulomas and in the size of the granulomatous reaction. The same pattern of immunohistochemical labelling was seen in both groups. CD79alpha(+) B cells were scarce except in granuloma-associated lymphoid follicles;the majority of lymphocytes in granulomas and at other sites were CD3epsilon(+) T cells. The granulomatous reaction in the livers of piglets to schistosoma eggs from prenatal S. japonicum infection was similar to that seen in postnatal infection. Signs of immunomodulation of granulomas between the two timepoints of infection were not demonstrable.

Consecutive pathological and immunological alterations during experimentally induced swine dysentery - a study performed by repeated endoscopy and biopsy samplings through an intestinal cannula.

The development of intestinal lesions after inoculation with Brachyspira hyodysenteriae was followed by repeated endoscopy and biopsy sampling through a caecal cannula. Seven eight-week-old pigs were cannulated and inoculated, two were cannulated but not inoculated, and two pigs were inoculated but not cannulated. Endoscopy, biopsy, and blood sampling to determine SAA (serum amyloid A), haptoglobin, cortisol, and WBC counts were performed at scheduled time-points. At the third day of disease, endoscopy showed a hyperaemic, perturbed mucosa and excessive amount of mucus. Histologically, crypt hyperplasia, depletion of goblet cell mucus, and erosions were noted. Simultaneously, elevated acute phase proteins and circulating monocytes, and decreased number of intraepithelial CD3(+) cells were observed. After five days the pigs recovered. Intestinal lesions were demarcated and interspersed among apparently normal mucosa and blood parameters returned to initial values. Endoscopy through an intestinal cannula made it possible to follow the development of intestinal alterations in vivo and describe the sequential events during the course of swine dysentery. The number of animals used in a study could thus be minimised and the precision of the experiment increased.

Immunomodulation of the hepatic egg granuloma in Schistosoma japonicum-infected pigs.

Immunomodulation of perioval granulomas is a well-known phenomenon in schistosome-infected mice, but only little is known about granuloma modulation in other animal models of human schistosomiasis. In the present study, we explored immunomodulation of egg granulomas in the liver in a pig model of schistosomiasis japonica. Granuloma size was measured and T cells, B cells and IgG(+) plasma cells in granulomas were quantified in pigs at 9, 12 and 21 weeks post infection (wpi) with Schistosoma japonicum. Granulomas were largest at 9 wpi, had decreased significantly in size at 12 wpi and remained small at 21 wpi (9 vs. 12 and 21 wpi: P < 0.05). The size of granulomas containing mature and immature eggs, respectively, did not differ significantly. The density of T (CD3epsilon(+)) cells and IgG(+) plasma cells in granulomas was the same, irrespective of granuloma size and time points. B (CD79alpha(+)) cells were rare in granulomas. The results indicate that in pigs, S. japonicum egg granulomas in the liver are immunomodulated at an early stage of infection, and that not only mature but also immature eggs induce a marked granulomatous reaction in this species.

Treatment efficacy and regulatory host responses in chronic experimental Schistosoma bovis infections in goats.

The aim of this study was to elucidate the regulatory responses and the long-term effect of praziquantel treatment in chronically Schistosoma bovis-infected West African Dwarf goats. Forty-two goats were used and the design comprised a primary infection followed by treatment at week 13, challenge infection at week 36 and termination at week 52. Dependent variables included clinico-pathological data, worm numbers, faecal and tissue egg counts, and gross pathology of the liver. The results showed that primary infections remained suppressed for up to 52 weeks and, although challenge infections imposed on 36-week-old primary infections established fully, the impairment of their egg production capacity provided protection against clinico-pathological consequences measured by body weight and haemoglobin levels. The study also confirmed a high efficacy (97.7%) of praziquantel for treatment of S. bovis infection in goats and showed that anthelminthic removal of primary infections does not interfere with the ability of the goat to elicit a marked resistance to a subsequent challenge infection. Although treated goats had more fibrous scarring of livers than untreated goats, no negative effects of liver lesions were reflected in weight gains of treated goats. This study provides strong evidence for the beneficial effects of anthelminthic treatment of young domestic stock as an element of treatment and preventive programmes.

Differential regulation of metzincins in experimental chronic renal allograft rejection: potential markers and novel therapeutic targets.

Chronic renal allograft rejection is characterized by alterations in the extracellular matrix compartment and in the proliferation of various cell types. These features are controlled, in part by the metzincin superfamily of metallo-endopeptidases, including matrix metalloproteinases (MMPs), a disintegrin and metalloproteinase (ADAM) and meprin. Therefore, we investigated the regulation of metzincins in the established Fisher to Lewis rat kidney transplant model. Studies were performed using frozen homogenates and paraffin sections of rat kidneys at day 0 (healthy controls) and during periods of chronic rejection at day +60 and day +100 following transplantation. The messenger RNA (mRNA) expression was examined by Affymetrix Rat Expression Array 230A GeneChip and by real-time Taqman polymerase chain reaction analyses. Protein expression was studied by zymography, Western blot analyses, and immunohistology. mRNA levels of MMPs (MMP-2/-11/-12/-14), of their inhibitors (tissue inhibitors of metalloproteinase (TIMP)-1/-2), ADAM-17 and transforming growth factor (TGF)-beta1 significantly increased during chronic renal allograft rejection. MMP-2 activity and immunohistological staining were augmented accordingly. The most important mRNA elevation was observed in the case of MMP-12. As expected, Western blot analyses also demonstrated increased production of MMP-12, MMP-14, and TIMP-2 (in the latter two cases as individual proteins and as complexes). In contrast, mRNA levels of MMP-9/-24 and meprin alpha/beta had decreased. Accordingly, MMP-9 protein levels and meprin alpha/beta synthesis and activity were downregulated significantly. Members of metzincin families (MMP, ADAM, and meprin) and of TIMPs are differentially regulated in chronic renal allograft rejection. Thus, an altered pattern of metzincins may represent novel diagnostic markers and possibly may provide novel targets for future therapeutic interventions.

Qualitative and quantitative analysis of antibody response against IFNbeta in patients with multiple sclerosis.

To date, inter- and intra-laboratory consistency of binding assays for measuring anti-interferon (IFN)beta antibodies has not been assessed. In this investigation, two independent laboratories tested a library of 80 serum specimens obtained from multiple sclerosis (MS) patients treated with IFNbeta. For binding antibodies (BAbs) evaluations, each laboratory used both a capture-ELISA (cELISA) and an enzyme-immuno-assay (EIA), which is commercially available. Samples were also tested for neutralizing antibodies (NAbs). Data demonstrated good intra-laboratory reliability (r(pearson) > or = 0.86), and a good overall agreement between the results obtained from the two centers, using both the cELISA (69/80 of observed agreements) and the EIA (67/80). Accordingly, kappa coefficients (K) showed good concurrence (K > or = 0.651). There was also substantial agreement between cELISA and EIA measurements, as performed in both centers (Orbassano, 66/80, K = 0.631; Basel, 70/80, K = 0.717). However, by comparing NAbs and BAbs titers obtained with both assays, we found that a high degree of BAb-negative samples were positive in NAb-assay. Thus, our study does not support the usefulness of ELISA-based BAb assays as a screening tool for NAbs. Otherwise, BAb-assays can be used as a confirmation test, indicating that the decrease of the biological effects is due to antibodies. In this context, both ELISA-based assays are equally reliable techniques.

Inhibition of matrix metalloproteinases and tumour necrosis factor alpha converting enzyme as adjuvant therapy in pneumococcal meningitis.

Matrix metalloproteinases (MMPs) and tumour necrosis factor alpha (TNF-alpha) converting enzyme (TACE) contribute synergistically to the pathophysiology of bacterial meningitis. TACE proteolytically releases several cell-surface proteins, including the proinflammatory cytokine TNF-alpha and its receptors. TNF-alpha in turn stimulates cells to produce active MMPs, which facilitate leucocyte extravasation and brain oedema by degradation of extracellular matrix components. In the present time-course studies of pneumococcal meningitis in infant rats, MMP-8 and -9 were 100- to 1000-fold transcriptionally upregulated, both in CSF cells and in brain tissue. Concentrations of TNF-alpha and MMP-9 in CSF peaked 12 h after infection and were closely correlated. Treatment with BB-1101 (15 mg/kg subcutaneously, twice daily), a hydroxamic acid-based inhibitor of MMP and TACE, downregulated the CSF concentration of TNF-alpha and decreased the incidences of seizures and mortality. Therapy with BB-1101, together with antibiotics, attenuated neuronal necrosis in the cortex and apoptosis in the hippocampus when given as a pretreatment at the time of infection and also when administration was started 18 h after infection. Functionally, the neuroprotective effect of BB-1101 preserved learning performance of rats assessed 3 weeks after the disease had been cured. Thus, combined inhibition of MMP and TACE offers a novel therapeutic strategy to prevent brain injury and neurological sequelae in bacterial meningitis.

The expression profile of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) in lesions and normal appearing white matter of multiple sclerosis.

In multiple sclerosis, matrix metalloproteinases (MMPs) are effectors of crucial pathogenetic steps, such as blood-brain barrier breakdown, invasion of brain parenchyma by immune cells and demyelination. However, only limited data are available on the types of MMPs induced in the course of multiple sclerosis, and on the role of their endogenous antagonists, the tissue inhibitors of metalloproteinases (TIMPs). We quantified the transcriptional expression of six MMPs and the four TIMPs in lesions and in normal appearing white matter (NAWM) from post-mortem multiple sclerosis brain tissue by real-time polymerase chain reaction, and compared levels with those in brain tissue from six control patients without neurological disease. The mRNA expression of MMP-7 and -9, but not of other metalloproteinases [MMP-2 and -3, and tumour necrosis factor (TNF)-alpha-converting-enzyme] was equally upregulated throughout all stages of lesion formation with active inflammation, and in most of matched NAWM tissue. The transcription of cytokines TNF-alpha/beta and IL (interleukin)-2, known modulators of MMPs, was upregulated only in distinct stages of lesion formation, while their receptors were not induced at all, which suggests that additional signalling molecules participate in the sustained upregulation of MMP-7 and -9 in multiple sclerosis. None of the TIMPs showed a significant induction over baseline expression of controls. We hypothesize that an imbalance between MMP and TIMP expression may cause a persistent proteolytic overactivity in multiple sclerosis, that may be a factor for continuous tissue destruction, and hence for secondary disease progression.

Intestinal cannulation: model for study of the midgut of the pig.

PURPOSE: To develop a pig model that would enable repeated biopsy specimen collection and endoscopic monitoring of the gut. This would increase precision of the experiment and reduce the number of experimental animals required. METHODS: Six 10-week-old Yorkshire pigs underwent surgery, and a cannula was inserted in the cecum. Two pigs served as non-operated controls. The health status of the animals was monitored by clinical, hematologic, and biochemical examinations and by studies of gut motility and microbial flora. The experimental period lasted for eight weeks and approximately 45 biopsy specimens were obtained from each animal. RESULTS: Repeated endoscopy was performed and biopsy specimens were taken. Adverse effects on the animal's health were not apparent, and differences were not evident in transit time of digesta or in diversity of the gut microbial flora. After surgery there was a transient increase in the concentrations of haptoglobin, serum amyloid A, and plasma cortisol, and in body temperature and white blood cell count. CONCLUSIONS: It is possible to use an intestinal cannula in the cecum both for endoscopy and biopsy specimen collection. The procedures did not influence health status of the pigs, nor alter gut function. The method will be useful in experimental infection studies as well as in other physiologic investigations.

Pathology and course of natural Schistosoma japonicum infection in pigs: results of a field study in Hubei province, China.

In order to obtain information on the natural course of porcine infection with Schistosoma japonicum, pigs were exposed to the cercariae of this parasite in a highly endemic region of China. Five, 5-month-old pigs previously infected with S. japonicum (group A) and 10, schistosome-naïve piglets (group B) were allowed on a pasture infested with Oncomelania snails for one transmission period (approximately 5.5 months). All the piglets rapidly acquired infection, and both groups remained infected throughout the study period. Group B showed fever, diarrhoea and anorexia in the early egg-excretion phase, and marked growth reduction. In both groups, post-mortem examination revealed live schistosomes and lesions associated with dead worms in the intestinal and mesenteric vasculature, and egg-related pathology in the large intestine and liver. Major findings were exudative lesions connected with egg excretion in the intestine, and granulomatous obstruction of portal veins in the liver. Signs of granuloma modulation were found in the liver, but not in the intestine. In conclusion, the study showed that field exposure of pigs to S. japonicum for one transmission period resulted in clinical disease and growth retardation in the youngest pigs, and significant pathology in both groups. Self cure, prominent in experimental porcine infections produced with single, high-dose inocula, was not induced in either group.

Tissue responses in experimental schistosomiasis japonica in the pig: a histopathologic study of different stages of single low- or high-dose infections.

The tissue responses of pigs exposed to either 100 or 2,000 Schistosoma japonicum cercariae were examined at 4, 11, 17, and 24 weeks postinfection (PI) to explore the pig as an animal model for pathologic aspects of human schistosomiasis japonica. Egg granulomas were present in the liver, intestine, and occasionally in the lungs from 11 weeks PI. There were also many free eggs and early exudative reactions to eggs in the intestine. At 11 weeks PI, pigs in the higher dose group showed marked periportal and septal fibrosis with minimal parenchymal destruction. Thereafter, lesions regressed spontaneously as the pigs underwent a self-cure. The lower dose group showed only mild lesions throughout the study. The degree of hepatic fibrosis was correlated with the density of eggs and granulomas in liver tissue. The results indicate that the pig would be particularly useful for studies of the development and resolution of schistosomal hepatic fibrosis, and also for investigations of the mechanisms behind the self-cure phenomenon.

The ephrin-A1 ligand and its receptor, EphA2, are expressed during tumor neovascularization.

Eph receptor tyrosine kinases and their ephrin ligands have been implicated in embryonic vascular development and in in vivo models of angiogenesis. Eph proteins may also regulate tumor neovascularization, but this role has not been previously investigated. To screen for Eph proteins expressed in tumor blood vessels, we used tumor xenografts grown in nude mice from MDA-MB-435 human breast cancer cells or KS1767 human Kaposi's sarcoma cells. By immunohistochemistry, the ephrin-A1 ligand and one of its receptors, EphA2, were detected throughout tumor vasculature. Double-labeling with anti-CD34 antibodies demonstrated that both ephrin-A1 and EphA2 were expressed in xenograft endothelial cells and also tumor cells. Furthermore, EphA2 was tyrosine-phosphorylated in the xenograft tumors, indicating that it was activated, presumably by interacting with ephrin-A1. Ephrin-A1 and EphA2 were also detected in both the vasculature and tumor cells of surgically removed human cancers. In an in vitro angiogenesis model, a dominant negative form of EphA2 inhibited capillary tube-like formation by human umbilical vein endothelial cells (HUVECs), demonstrating a requirement for EphA receptor signaling. These data suggest that ephrin-A1 and EphA2 play a role in human cancers, at least in part by influencing tumor neovascularization. Eph proteins may represent promising new targets for antiangiogenic cancer treatments.