Fish and macroinvertebrate assemblages reveal extensive degradation of the world's rivers

Rivers suffer from multiple stressors acting simultaneously on their biota, but the consequences are poorly quantified at the global scale. We evaluated the biological condition of rivers globally, including the largest proportion of countries from the Global South published to date. We gathered macroinvertebrate- and fish-based assessments from 72,275 and 37,676 sites, respectively, from 64 study regions across six continents and 45 nations. Because assessments were based on differing methods, different systems were consolidated into a 3-class system: Good, Impaired, or Severely Impaired, following common guidelines. The proportion of sites in each class by study area was calculated and each region was assigned a Köppen-Geiger climate type, Human Footprint score (addressing landscape alterations), Human Development Index (HDI) score (addressing social welfare), % rivers with good ambient water quality, % protected freshwater key biodiversity areas; and % of forest area net change rate. We found that 50% of macroinvertebrate sites and 42% of fish sites were in Good condition, whereas 21% and 29% were Severely Impaired, respectively. The poorest biological conditions occurred in Arid and Equatorial climates and the best conditions occurred in Snow climates. Severely Impaired conditions were associated (Pearson correlation coefficient) with higher HDI scores, poorer physico-chemical water quality, and lower proportions of protected freshwater areas. Good biological conditions were associated with good water quality and increased forested areas. It is essential to implement statutory bioassessment programs in Asian, African, and South American countries, and continue them in Oceania, Europe, and North America. There is a need to invest in assessments based on fish, as there is less information globally and fish were strong indicators of degradation. Our study highlights a need to increase the extent and number of protected river catchments, preserve and restore natural forested areas in the catchments, treat wastewater discharges, and improve river connectivity.

Disparities in Radiotherapy: Practice Patterns Analysis of DIBH use in Non-English Speakers

PURPOSE/OBJECTIVES

To examine current practice patterns in non-English speaking patients with breast cancer undergoing Deep Inspiratory Breath Hold (DIBH).

MATERIALS/METHODS

An anonymous, voluntary REDCap survey was distributed to 60 residency program coordinators of U.S. radiation oncology departments to survey their faculty and recent graduates. Eligibility was limited to board-certified radiation oncologists who have treated breast cancer within the prior 6 months.

RESULTS

There were 69 respondents, 53 of whom were eligible. 42% (n=22) of eligible respondents were from the main site at an academic center, with 28% (n=15) representing a satellite site, and 30% (n=16) from private practice. 53% reported at least 10% of their patients were non-English speaking. 90% offered DIBH at their institution and of those, 74% used DIBH for at least 1/4^th of their patients with breast cancer. 98% of those who use DIBH performed coaching at simulation, with 32% answering they would be "less likely" to utilize DIBH for non-English speakers. When utilized, 94% take into consideration potential language barriers for proper execution of DIBH. However, 51% had an interpreter present 76-100% of the time at CT simulation, which decreased to 31% at first fraction, and 11% at subsequent treatments. For non-English speaking patients undergoing DIBH coaching without a certified interpreter, 55% of respondents indicated that they provided verbal coaching in English, 32% indicated "not applicable" because they always use a certified interpreter, 11% used visual aids, and 32% indicated "other." Of those who answered other, the most commonly cited response was utilizing therapists or staff who spoke the patient's native language.

CONCLUSIONS

Disparities in the application of DIBH exist despite its established utility in reducing cardiac dose. This study provides evidence that language barriers may impact physician treatment practices from initial consideration of DIBH to subsequent delivery. This data suggests that breast cancer treatment considerations and subsequent execution are negatively affected in non-English speaking patients.

A strategic sampling design revealed the local genetic structure of cold-water fluvial sculpin: a focus on groundwater-dependent water temperature heterogeneity

A key piece of information for ecosystem management is the relationship between the environment and population genetic structure. However, it is difficult to clearly quantify the effects of environmental factors on genetic differentiation because of spatial autocorrelation and analytical problems. In this study, we focused on stream ecosystems and the environmental heterogeneity caused by groundwater and constructed a sampling design in which geographic distance and environmental differences are not correlated. Using multiplexed ISSR genotyping by sequencing (MIG-seq) method, a fine-scale population genetics study was conducted in fluvial sculpin Cottus nozawae, for which summer water temperature is the determinant factor in distribution and survival. There was a clear genetic structure in the watershed. Although a significant isolation-by-distance pattern was detected in the watershed, there was no association between genetic differentiation and water temperature. Instead, asymmetric gene flow from relatively low-temperature streams to high-temperature streams was detected, indicating the importance of low-temperature streams and continuous habitats. The groundwater-focused sampling strategy yielded insightful results for conservation.

Geology-dependent impacts of forest conversion on stream fish diversity

Forest conversion is one of the greatest global threats to biodiversity, and land-use change and subsequent biodiversity declines sometimes occur over a variety of underlying geologies. However, how forest conversion and underlying geology interact to alter biodiversity is underappreciated, although spatial variability in geology is considered an integral part of sustaining ecosystems. We aimed to examine the effects of forest conversion to farmland, the underlying geology, and their interaction on the stream fishes' diversity, evenness, and abundance in northeastern Japan. We disentangled complex pathways between abiotic and biotic factors with structural equation modeling. Species diversity of stream fishes was indirectly shaped by the interaction of land use and underlying geology. Diversity declined due to nutrient enrichment associated with farmlands, which was mainly the result of changes in evenness rather than by changes in species richness. This impact was strongest in streams with volcanic geology with coarse substrates probably because of the differential responses of abundant stream fishes to nutrient enrichment (i.e., dominance) and the high dependency of these fishes on large streambed materials during their life cycles. Our findings suggest that remediation of deforested or degraded forest landscapes would be more efficient if the interaction between land use and underlying geology was considered. For example, the negative impacts of farmland on evenness were larger in streams with volcanic geology than in other stream types, suggesting that riparian forest restoration along such streams would efficiently provide restoration benefits to stream fishes. Our results also suggest that land clearing around such streams should be avoided to conserve species evenness of stream fishes.

Bovine Endocarditis Associated with Mycoplasma bovis

Mycoplasma bovis is a microorganism associated with pneumonia, mastitis, arthritis and otitis media of cattle; however, there are no reports of this organism causing bovine endocarditis. Five adult cattle with endocarditis characterized by caseated lesions (diameter 5-12 cm) of the endocardial surface of the left atrium, but without lesions in heart valves or affecting the right side of the heart, were identified in slaughterhouses in Japan. M. bovis was successfully isolated from the lesions and M. bovis antigen was detected immunohistochemically within the lesions. The results suggest that the lesions may have been associated with M. bovis alone. To our knowledge, this is the first demonstration of bovine endocarditis associated with M. bovis.

Predicting the ecological impacts of large-dam removals on a river network based on habitat-network structure and flow regimes

Large dams provide vital protection and services to humans. However, an increasing number of large dams worldwide are old and not operating properly. The removal of large dams has excellent potential to restore habitat connectivity and flow regimes; therefore, projecting the related ecological consequences is an emerging need for water resource and ecosystem management. However, no modeling methods are currently available for such projections at the basin scale. We devised a scheme that integrates changes in flow regimes and habitat network structure into a basin-scale impact assessment of removal of large dams and applied it to the Nagara-Ibi Basin, Japan. We used a graph-theoretical approach and a hydrological model, to quantify changes in habitat availability for 11 freshwater fishes at the basin scale under multiple removal scenarios. We compared these results with the change predicted using a conventional scheme that considered only changes to the habitat network due to dam removal. Our proposed scheme revealed that an increase in flow variability associated with dam removal projected both positive and negative effects on basin-scale habitat availability, depending on the focal species, endangered species had a negative response to dam removal. In contrast, the conventional approach projected only positive effects for all species. This difference in the outcomes indicates that large-dam removal can have negative and positive effects on watershed restoration due to changes in flow regimes. Our results also suggest the effect of removal of large dams may depend on the dams and their locations. Our study is the first step in projecting ecological trade-offs associated with the removal of large dams on riverscapes at the basin scale and provides a foundation for future process-based watershed restoration.

Appearance of US-like porcine epidemic diarrhoea virus (PEDV) strains before US outbreaks and genetic heterogeneity of PEDVs collected in Northern Vietnam during 2012-2015

Porcine epidemic diarrhoea virus (PEDV) is the aetiologic agent of porcine epidemic diarrhoea (PED), a highly contagious enteric disease that is threatening the swine industry globally. Since PED was first reported in Southern Vietnam in 2009, the disease has spread throughout the country and caused substantial economic losses. To identify PEDVs responsible for the recent outbreaks, the full-length spike (S) gene of 25 field PEDV strains collected from seven northern provinces of Vietnam was sequenced and analysed. The sequence analysis revealed that the S genes of Vietnamese PEDVs were heterogeneous and classified into four genotypes, namely North America and Asian non-S INDEL, Asian non-S INDEL, new S INDEL and classical S INDEL. This study reported the pre-existence of US-like PEDV strains in Vietnam. Thirteen Vietnamese variants had a truncated S protein that was 261 amino acids shorter than the normal protein. We also detected one novel variant with an 8-amino acid insertion located in the receptor-binding region for porcine aminopeptidase N. Compared to the commercial vaccine strains, the emerging Vietnamese strains were genetically distant and had various amino acid differences in epitope regions and N-glycosylation sites in the S protein. The development of novel vaccines based on the emerging Vietnamese strains may be contributive to the control of the current PED outbreaks.

Campylobacter and Salmonella are prevalent in broiler farms in Kyushu, Japan: results of a 2-year distribution and circulation dynamics audit

AIM

To elucidate the distribution and circulation dynamics of Campylobacter and Salmonella in Japanese chicken broiler flocks.

METHODS AND RESULTS

A 2-year investigation of the distribution of Campylobacter and Salmonella was conducted in 25 broiler flocks at nine farms in Japan from 2013 to 2014. Campylobacter and Salmonella tested positive in 11 (44·0%) and 24 (96·0%) broiler flocks respectively. One hundred and ninety-five Campylobacter and 184 Salmonella isolates were characterized into 12 Campylobacter (including two novel genotypes) and three Salmonella MLST genotypes. Only Salmonella isolation between caecal and environmental samples were significantly correlated. Further, one litter sample tested positive for Salmonella before new chicks were introduced. The Campylobacter strains rapidly lost culturability within 2-18 days; in contrast, the Salmonella strains survived from 64-211 days in artificially inoculated water samples.

CONCLUSION

No persistent circulation-mediated Campylobacter contamination was observed. In contrast, circulation of Salmonella in broiler houses was seen, apparently due to the litter excreted from broiler flocks, as well as Salmonella-contaminated water and feed.

SIGNIFICANCE AND IMPACT OF THE STUDY

This paper provides the distribution, genotypic data and circulation dynamics of Campylobacter and Salmonella as recently observed in Japanese chicken broiler farms.

To what extent do human-altered landscapes retain population connectivity? Historical changes in gene flow of wetland fish Pungitius pungitius

Understanding how human-altered landscapes affect population connectivity is valuable for conservation planning. Natural connectivity among wetlands, which is maintained by floods, is disappearing owing to farmland expansion. Using genetic data, we assessed historical changes in the population connectivity of the ninespine stickleback within a human-altered wetland system. We predicted that: (i) the contemporary gene flow maintained by the artificial watercourse network may be restricted to a smaller spatial scale compared with the gene flow preceding alteration, and (ii) the contemporary gene flow is dominated by the downstream direction owing to the construction of low-head barriers. We evaluated the potential source population in both timescales. Seventeen studied populations were grouped into four genetically different clusters, and we estimated the migration rates among these clusters. Contemporary migration was restricted to between neighbouring clusters, although a directional change was not detected. Furthermore, we consistently found the same potential source cluster, from past to present, characterized by large amounts of remnant habitats connected by artificial watercourses. These findings highlight that: (i) artificial connectivity can sustain the short-distance connectivity of the ninespine stickleback, which contributes to maintaining the potential source populations; however, (ii) population connectivity throughout the landscape has been prevented by agricultural developments.

An analysis of factors affecting production performance in broiler flocks on Japanese commercial farms

1. The present study determined descriptive values of the main production measurements of flocks and assessed the relationship between these measurements and related management factors in Japanese commercial broiler farms. 2. The data set included 5060 flock records from 183 farms. The production index was calculated as follows: liveability × average daily gain/feed conversion ratio × 10. Management factors included in the analysis were broiler breeder age, the time interval between successive flocks, the season of placement and stocking density. 3. The mean (±SD) production index was 283.9 ± 28.83. Management factors significantly associated with a decreased production index were low broiler breeder age, flocks placed in summer and high stocking density (P < 0.05). 4. In regard to an interaction for the production index, flocks with high stocking density had a lower production index than those with low stocking density in flocks with a low broiler breeder age (P < 0.05). In summer, flocks with a short time interval between successive flocks had a lower production index than those with an intermediate or long time interval (P < 0.05). 5. The present study identified factors related to flock performance. The knowledge obtained from this analysis will contribute to improve flock performance by optimising management.

The monitoring of insects to maintain biodiversity in Ogawa Fores Reserve

The results of a biodiversity monitoring program conducted in the Ogawa Forest Reserve and its vicinity, situated in a cool temperate region of Japan, identified three different patterns for species richness. Forests of the region are characterized by a mosaic of secondary deciduous stands of various ages scattered among plantations of conifers. The three different types of change in species richness observed in response to the stand age are as follows: Type I (butterflies, tube-renting bees and wasps, hoverflies, fruit flies, and longicorn beetles), the species diversity was highest in open areas, just after clear-cutting, decreasing with the stand age; Type II (mushrooms and mites associated with them), older stands showed greater diversity than younger stands; and, Type III (moths, oribatid mites, collembolas, carabid beetles, and ants), the number of species did not change greatly with the stand age, though ordination analysis revealed that there was variation in species compositions. These results indicate that combinations of stands of different ages, or heterogeneously arranged stands, can contribute to the maintenance of insect biodiversity at the landscape level.

Comparative studies of the persistence of animal mycoplasmas under different environmental conditions

A comparison of the persistence of mycoplasmas in animals was carried out. When inoculated into liquid media, strains of Mycoplasma bovis, M. arginini, Acholeplasma laidlawii, and A. axanthum persisted for 59-185 days post-inoculation. The survival periods were not significantly influenced by temperature (4, 30, 37 degrees C, and room temperature). The survival periods for M. bovigenitalium, M. gallisepticum, M. bovirhinis, and M. gateae ranged from <7 to 185 days depending on medium components and temperature. Further, it was determined that strains of M. bovigenitalium, M. bovis, M. bovirhinis, M. arginini, and A. laidlawii persisted in a dry paper disc for at most 28, 126, 154, 56 and over >168 days at 4 degrees C, respectively. At 4 degrees C, strains of M. gallisepticum, M. columborale, M. edwardii, M. felis, and M. gateae survived for at most 28, 21, 42, 28, 28 and 70 days, respectively. At 30 degrees C, strains of M. bovis, M. bovirhinis, M. arginini, A. laidlawii, and M. gallisepticum persisted for at most 28, 84, 56, >168 and 14 days, respectively, but strains of M. gallisepticum, M. columborale, M. edwardii, M. felis, M. gateae, and U. diversum did not survive for more than 14 days. In an outdoor environment, strains of M. bovirhinis and A. laidlawii survived for at most 28 and 14 days, respectively. Finally, it was found that 14 isolates of M. gallisepticum persisted for periods similar to those of the reference strains. The results under dry conditions at a variety of temperatures presented contribute to understanding the epizootiology of mycoplasmal infections in the field.

Effect of bicozamycin on the eradication of Shiga toxin-producing Escherichia coli in calves

Fifty-nine calves, aged 11 days to 9 months, from three farms breeding Japanese Black beef cattle in Miyazaki Prefecture, Japan, were examined for the presence of Shiga toxin-producing Escherichia coli (STEC). A high prevalence of STEC was detected among calves, with 45 (76.3%) animals carrying STEC including different serogroups (O26, O74, O111, O114, O119, O127, O153, O157, and ONT) and toxin types. The number of STEC in the feces was estimated by a combined method involving enumeration of colony-forming units by a plate-most-probable-number (plate-MPN) technique and polymerase chain reaction for the detection of Shiga toxin genes. Fecal shedding ranged from 10(1) to 10(10) MPN/g feces. To evaluate the safety and efficacy of bicozamycin (BCM: previously named as bicyclomycin) in eradicating STEC, 30 calves carrying STEC with or without diarrhea were examined. Fifteen calves were treated orally with BCM (10 mg/kg/day) once daily for 5 days, and the other 15 were untreated. Twenty-four hours after the last dose, fecal specimens were collected from both groups to compare the number of coliforms and STEC with those before treatment. BCM-treated animals had a significantly lower number of coliforms and STEC compared to the untreated calves. The STEC eradication rate was 86.6% (13/15) in the BCM-treated group, compared to 0% (0/15) in the control group. The corresponding cure rates for diarrhea were 87.5 (7/8) and 0% (0/3), respectively. No adverse reactions were observed in the calves during treatment. It is concluded that BCM is an effective agent for the eradication of STEC in calves with or without diarrhea.

Detection of Akabane viral antigens in spontaneous lymphohistiocytic encephalomyelitis in cattle

A 5-month-old Japanese black bull calf and twenty-seven 1-27-day-old calves exhibiting neurological signs between August and October 1998 were examined. The bull calf exhibited rapid breathing, fever, hypersensitivity, and ataxia and was euthanized 4 days after the onset of symptoms. The 27 calves primarily exhibited ataxia, and 15 had arthrogryposis. Histological examination of the bull calf revealed perivascular infiltraction by mononuclear cells, diffuse to multifocal gliosis, and neuronal necrosis in the brain and spinal cord. Multiple malacic foci were found in the midbrain in 5 cases. In contrast, in the 15 calves necropsied in October, there were fewer inflammatory changes, but there was neuronal cell loss in the ventral horn and a decrease in myelinated axons in the lateral and ventral funiculi. Immunohistochemical examination using a rabbit antiserum against Akabane virus strain OBE-1 revealed a large amount of viral antigen in the degenerating neurons and glial cells of the bull calf, mainly in the spinal gray matter. Small amounts of viral antigen in swollen axons and a few glial cells were found in 5 of 27 calves. Thirteen of the 27 calves had high neutralization antibody titers against the Akabane virus, whereas there was no significant antibody titer in most of the calves necropsied during August. The present study revealed that viral antigen detection was very useful for the diagnosis of Akabane diseases in the 5-month-old bull calf that was suspected to be infected postnatally, while it had limited usefulness in the other young calves.

Intestinal spirochetosis in wild sika deer (Cervus nippon yesoensis) infected with Brachyspira species

Seven adult free-ranging sika deer (Cervus nippon yesoensis) were examined by histology, immunohistochemistry and electron microscopy for intestinal spirochetal infection. Histologically epithelial and goblet cell hyperplasia and edema of the lamina propria mucosa with macrophage and lymphocyte infiltration were observed in the cecum and colon in 6 of the 7 deer. Numerous argyrophilic spirochetes were present in the crypts and some had invaded epithelial and goblet cells and caused degeneration. Immunohistochemically the organisms stained positively with polyclonal antisera against Brachyspira (Serpulina) hyodysenteriae and B. pilosicoli. Ultrastructurally they were 6-14 microm long, 0.2-0.3 microm wide and had 4-6 coils and 13 axial filaments per cell; such features were closely similar to those in the Brachyspira species. These results showed that the spirochetes were capable of inducing enteritis in deer and this intestinal spirochete infection might already be prevalent among wild sika deer in Japan. There is a possibility that this spirochetal colitis is a new syndrome in sika deer and that the same and/or similar spirochetes have infected ruminants, including sika deer and cattle.

Isolation of porcine epidemic diarrhea virus in porcine cell cultures and experimental infection of pigs of different ages

This paper describes the isolation of porcine epidemic diarrhea (PED) virus in Vero and porcine cell cultures, and the influence of age on disease in experimental infection. PED virus was isolated from the small intestine of piglets inoculated with PED samples and cultured in Vero, porcine bladder and kidney cells propagated in collagen-coated tissue culture plates in maintenance medium (MM) containing trypsin. In porcine bladder and kidney cell cultures inoculated with isolated PED virus, cytopathic effects (CPE) including cell fusion were detected. Specific brilliant fluorescence was observed in the cytoplasm of these cells. Two- and 7-day old, and 2-, 4-, 8- and 12-week old specific pathogen-free (SPF) pigs were orally inoculated with PED virus isolated from an outbreak. All 2- and 7-day old pigs inoculated developed severe watery diarrhea from post-inoculation day (PID) 1 and died between PID 3 and 4. Although three of five 2-week old pigs developed diarrhea on PID 1-4, they eventually recovered. In the 4-week old group, three of five pigs had mild diarrhea for 1-2 days. None of the 8- and 12-week old pigs showed any clinical signs. Antibodies against PED virus were detected in all surviving pigs by virus neutralization (VN) test and immunofluorescence assay (IFA). Therefore, there is an age-dependent resistance to pathogenic PED virus infection in pigs.

[Estimation of probiotics by infection model of infant rabbit with enterohemorrhagic Escherichia coli O157:H7]

We examined the preventative effect against enterohemorrhagic Escherichia coli O157:H7 (EHEC) infection in rabbits on administration of probiotics contained in Streptococcus faecalis, Clostridium butyricum and Bacillus mesentericus. The probiotics were administered to 5 days old Japanese white rabbits throughout the experiment. Inoculation of 10(6) colony forming units (CFUs) of EHEC per rabbit was tried 8 days after birth. Three days after EHEC inoculation, in the control group (not administered probiotics), diarrhea was observed in approximately 80% of the rabbits, on the other hand, in the group administered probiotics, rabbits showed diarrhea in 15%. In necropsy, the number of EHEC in the contents of the cecum and the number of attaching and effacing (AE) lesions were fewer in the probiotics group than in the control group. These results suggest that infant rabbits are useful as a colitis model for EHEC, and the probiotics are effective for the prevention of the growth of EHEC in the intestine and for diarrhea.

A novel developmental process of intestinal epithelial lesions in a calf infected with attaching and effacing Escherichia coli

A comparative study on the adhesion of attaching and effacing Escherichia coli (AEEC) to the enterocytes between the colon of a calf and the jejunum of a piglet showed differences in the developmental process of attaching and effacing (AE) lesions. In the calf, pedestals consisted of fused microvilli, while in the piglet they developed from the apical epithelial cell membranes after effacing microvilli. Microvilli adjacent to the AEEC attachment site were atrophic in the calf, whereas they were elongated in the piglet. The production of AE lesions in the calf may be indicative of a novel developmental process with AEEC infection.

A chick model for the study of "attaching and effacing Escherichia coli" infection

Young chicks were experimentally infected with 6 strains of AEEC isolated from calves, pigs, chicks, and humans. AEEC colonized the cecum of chicks and induced the AE lesions on the mucosal surface. In the early stages of the AE lesions, AEEC attached to the enterocyte were enfolded with the microvilli. In the advanced stages, microvilli and cytoskeletons of the enterocytes were disrupted, and cytoplasmic cups and pedestal-like protrusions were formed on the cell surface. The AE lesions interconnected with the adjacent lesions, and it formed the network on the mucosal surface. Leukocytes infiltrated in the mucosa associated with AE lesions, and lymphatic nodules also developed. The results of these studies support the conclusion that chicks can be used as a model for the study of the lesions caused by AEEC.

A new adherent form of an attaching and effacing Escherichia coli (eaeA+, bfp-) to the intestinal epithelial cells of chicks

The adherent site of "attaching and effacing Escherichia coli" (AEEC; O103: H-, SK-1 strain) on the intestinal epithelial cells of chicks infected naturally and experimentally was ultrastructurally investigated. The eaeA gene was detected by polymerase chain reaction in the SK-1 strain of E. coli isolated from the intestinal content of a chick infected naturally, however, the bundle-forming pilus (bfp) gene could not be detected. The SK-1 strain (bfp-) of AEEC could attach to the intestinal epithelial cell and induce attaching-effacing lesions in the intestine of chicks. Transmission electron microscopy revealed numerous pilus-like microfilaments in the space between colibacilli and the membranes of the intestinal epithelial cells. The present study suggests that SK-1 strain (eaeA+, bfp-) may attach closely to the intestinal epithelial cells by a novel adhesion different from bfp.

Natural infection with attaching and effacing Escherichia coli (O 103:H-) in chicks

The existence of natural infection with attaching and effacing Escherichia coli (AEEC) in chicks was reported. Numerous Gram-negative bacilli were attached to the enterocyte in association with lesions characterized on a wavy appearance of the mucosal surface in the intestines of six chicks. Immunohistochemically, these bacteria reacted positively with antiserum to Escherichia coli (O 103). By electron microscopy, numerous colibacilli were seen to be closely attached to the surface membranes of the enterocytes. In regions of bacterial attachment, almost all cell microvilli were effaced, and some of the remaining ones were elongated and/or disoriented. Part of the cell membrane formed a cup invagination and pedestal-like protrusion associated with the attached bacteria. A concentration of electron-dense material was seen beneath the adherent organisms. Bacteriologically, numerous E. coli (O 103:H-) were isolated from the jejunal contents of two chicks and the E. coli did not produce verotoxin or enterotoxin. The characteristic lesions could also be induced in the cecal mucosa of young chicks experimentally inoculated with the isolated E. coli. This is the first report of natural infection in chicks with AEEC.

An immunohistochemical investigation of porcine epidemic diarrhoea

A sudden outbreak of epidemic diarrhoea of piglets occurred in Japan, the principal features being watery diarrhoea, dehydration and high mortality in newborn animals. The microscopical lesions were villous atrophy in the small intestine, the villous enterocytes being vacuolated and cuboidal in shape. The villus-crypt ratio was severely reduced, varying from 1:1 to 3:1. Transmission electron microscopy showed numerous coronaviruses within the cytoplasm of enterocytes and among microvilli. Specific antigens of porcine epidemic diarrhoea (PED) virus were detected in the cytoplasm of enterocytes by the streptavidin-biotin (SAB) technique. Infected cells, which were most abundant in the villous epithelia of the jejunum and ileum, were present in small numbers in the large intestine, the crypt epithelia, the lamina propria and Peyer's patches. The study suggests that the SAB technique is useful for the diagnosis of PED.

Partial characterization of larval antigens of Strongyloides papillosus by western blot analysis

Western blotting was used to analyse the antigens in extracts of adult and infective larvae (SIL) of Strongyloides papillosus with serum of infected rabbits. Several proteins in both the extracts reacted with immunoglobulin G in the serum. A protein of about 16 kDa in the extract of SIL showed an especially strong reaction. No cross-reaction was observed among proteins in the extracts of adult worms of such cattle helminths as Fasciola gigantica, Homalogaster paloniae, Trichuris discolor and Setaria digitata to S. papillosus-infected rabbit serum. The cuticle of the worms and substances in the worm tracks showed positive reaction with the immunoperoxidase test on SIL with the serum.

Experimental infection of young chicks with attaching and effacing Escherichia coli

Young chicks were inoculated with six different strains of attaching and effacing Escherichia coli isolated from the feces of calves, pigs, chicks, and humans. Colibacilli of some serotypes had colonized the cecum of chicks by 7 days after inoculation. The characteristic lesions associated with bacterial attachment were also seen on the mucosal surface of the cecum. Electron microscopy revealed numerous colibacilli closely attached to the surface membrane of enterocytes. Cell membranes formed cups and pedestals at the base of the attached bacilli. The results of this study support the conclusion that young chicks can be used as a model for the study of the lesions caused by attaching and effacing E. coli strains.

Radiopacity of dental cements

The radiopacity of zinc phosphate, polycarboxylate and glass ionomer dental luting materials was determined and the values were compared with those of tooth substrates. The radiographs of the 2 mm thick specimens were taken together with tooth slices and pure aluminum step wedges. The radiographic density of the specimens was measured using a densitometer and expressed in terms of the equivalent thickness of aluminum per unit thickness of material. All the zinc phosphate and polycarboxylate cements showed radiopacity values greater than that of enamel (3.5), while one glass ionomer material showed a radiopacity value lower than that of dentin (2.0). A radiopacity value greater than 3.5 may be desirable for the detection of luting materials or for their distinction from decayed tooth structure on the dental radiograph.

Sarcoid granuloma-like lesions in the lungs of broiler chicks

Sarcoid granuloma-like lesions were observed in the lungs of two broiler chicks showing depressed growth. Multinucleated giant cells in the lesions often contained foreign bodies comprising amorphous and laminated material. These were morphologically similar to Schaumann bodies found in human sarcoidosis. This is the first report of sarcoid granuloma-like lesions and Schaumann body-like material in chickens.

Radiopacity and physical properties of titanium-polymethacrylate composite

Titanium-polymethacrylate composite was prepared as an x-ray-opaque filler for composite core materials. The base monomers of the composite were 2,2-bis [4-(3-methacryloyloxy-2-hydroxypropoxy) phenyl] propane (Bis-GMA) and triethyleneglycol dimethacrylate (TEGDMA). Pure titanium powder was used as a radiopaque element. Two functional methacrylates--isopropyl dimethacryloyl isostearoyl titanate (KR-7) and 4-methacryloyloxyethyl trimellitate anhydride (4-META)--were adopted as couplers of titanium powder. The radiopacity of composites was determined in terms of their equivalent thickness of aluminum per unit thickness of material. Compressive and transverse strengths of the composites were measured by use of coupled and untreated titanium fillers. The composites that contained 70% and 80% titanium by weight showed more radiopacity than enamel and less than amalgam. Radiopacity was controlled by the content of titanium filler in the composite. The decrease in compressive and transverse strengths of the composites was 0.7 to 15.9% and 43.7 to 52.9%, respectively, after one year's immersion in water. The decrease in transverse strength was remarkable; however, this deterioration was diminished by use of both KR-7 and 4-META as couplers for titanium. Thus, prepared titanium-polymethacrylate composite may be used as a radiopaque composite filler for self-curing composite core materials.

[Chick embryo culture using duck egg shell--first successful hatch ]

The suitability of duck egg shell (DES) for chick embryo culture was investigated. Chick embryos were transferred into DESs with all egg contents after 3 days of normal incubation and cultured. The vessels made of polyethylene cling film were used for shell-less control. Among 35 embryos cultured in DESs, 21 survived until 16 days of incubation (13 days after transfer) and finally 3 newly hatched chicks were obtained at 22 days of incubation. One of them died 4 days later, but remaining two became full-grown cocks showing normal body weight and production of fertile sperms. Among 37 embryos cultured in polyethylene vessels, none survived over the period of 19 days of incubation. It is suggested that DES culture system may be useful for the various experiments using chick embryos.

Diarrhea induced by Treponema hyodysenteriae: a young chick cecal model for swine dysentery

The experimental infection of 25 young chicks with Treponema hyodysenteriae was carried out. Treponemes were isolated from 21 of 25 chicks on day 21 after inoculation. The ceca of chicks infected with treponemes were atrophied. The lumen was filled with a white watery fluid instead of digested feed. In some infected chicks, a cecal core was observed with the fluid in the cecum. The cecal core was grayish, hard, and rod shaped. It consisted of eroded cells and debris of treponemes and resembled the pseudomembrane. Bloody mucus was also observed in one chick. The thickness of the mucosae in 17 of 25 chicks were markedly increased. The histological changes were classified into two types. In the case of regressive changes of epithelial cells which mean severe erosion, the laminae propriae were exposed. Hemorrhage, edema, and heterophil infiltration in the laminae propriae were also confirmed. Numerous treponemes were observed within the edematous area under the remaining epithelia and also invaded the epithelial cells and laminae propriae. In the other case, progressive changes, that is, hyperplasia of mucosal epithelial cells and elongation of the crypt, were observed. The epithelia consisted mainly of cuboidal basophilic cells, mitotic cells, and goblet cells. The mitotic cells increased in number and were also observed near the superficial luminal surface of the ceca. Mucous goblet cells were also considerably increased in number. The erosion of superficial luminal epithelial cells was not so severe, but edema in laminae propriae was frequently observed. Electron-microscopic observation demonstrated that the basophilic epithelial cells were polyribosome rich, mitochondria poor, and lipid droplet poor. Furthermore, tonofibril-like structures under the terminal web in cytoplasms were lost, and numerous membrane-bound vesicles at the terminal web with free ribosomes were observed. In places, a number of vesicles were observed between microvilli, and some vesicles were released from the apical cytoplasm of epithelial cells. Microvilli also became scarce and irregular. The junctional complexes between cuboidal cells became unclear, the interdigitations between cuboidal cells became loose, and the intercellular spaces were widened. In conclusion, the appearance of numerous membrane-bound vesicles at the terminal web and the dilated intercellular space indicates increased secretion of water and electrolytes, and the abnormal proliferation of such immature epithelial cells indicates impaired absorption. On the basis of our findings, we can say that diarrhea induced by T. hyodysenteriae can be developed by synergism between impaired absorption and increased secretion by intestinal mucosae with hyperplastic immature epithelial cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Enteropathogenicity of Treponema hyodysenteriae in young chicks

Observation by scanning electron microscopy served to demonstrate that Treponema hyodysenteriae colonized the cecal mucosa of young chicks on day 3 after inoculation and produced lesions from 9 days after inoculation. Severe and clearly visible lesions were present on the cecal mucosa of all chicks necropsied 18, 21, and 24 days after inoculation. Severe lesions such as roughness of mucosal surface and disappearance of the mucosal foldings were observed at low magnification. The lesions were characterized by a destruction of superficial epithelial cells and dilation of crypt orifices. The dilated orifices of crypts were clearly observed, and the number of the crypts increased as compared with that of the crypts on the cecal surface in non-infected chicks. At high magnification, mucosal epithelial cells were found to be desquamated and the surface of the lamina propria mucosae had appeared. Numerous treponemas became visible on the surface of damaged epithelial cells and on the surface of the lamina propria mucosae.

Investigations into the location of Treponema hyodysenteriae in the cecum of experimentally infected young broiler chicks by light- and electronmicroscopy

Numerous Treponema hyodysenteriae were present both on the mucosal surface and in the deep crypts of the cecum of young broiler chicks 7 and 14 days after inoculation with the treponemes. The treponemes in the ceca of chicks inoculated with 10(8) cells were observed more frequently than those of chicks inoculated with 10(7) cells. The treponemes in the ceca were observed by light microscopy, scanning electron microscopy and transmission electron microscopy. The lesions were primarily confined to the cecum. Desquamation of epithelial cells, edema, leukocytic infiltration and hemorrhage were observed in the mucosae.

Experimental infection of young broiler chicks with Treponema hyodysenteriae

In young broiler chicks which were inoculated with 10(8) cells of Treponema hyodysenteriae within 24 hr after hatching, numerous treponemes were observed by scanning electron microscopy on the surface of the cecal mucosa 7 and 14 days after the inoculation. However, in the groups inoculated with 10(7) cells, treponemes were not observed on the cecal mucosa 14 days after the inoculation, and the isolation rate from the cecal contents was lower than that from cecal contents of chicks inoculated with 10(8) cells. While the cecal mucosa of noninfected chicks had a smooth surface, that of the chicks infected with treponemes was generally roughened and the epithelium was eroded. Numerous treponemes were also observed within the eroded epithelium.