Examination of the exposome in an animal model: The impact of high fat diet and rat strain on local and systemic immune markers following occupational welding fume exposure.

The goal of this study was to investigate the impact of multiple exposomal factors (genetics, lifestyle factors, environmental/occupational exposures) on pulmonary inflammation and corresponding alterations in local/systemic immune parameters. Accordingly, male Sprague-Dawley (SD) and Brown Norway (BN) rats were maintained on either regular (Reg) or high fat (HF) diets for 24wk. Welding fume (WF) exposure (inhalation) occurred between 7 and 12wk. Rats were euthanized at 7, 12, and 24wk to evaluate local and systemic immune markers corresponding to the baseline, exposure, and recovery phases of the study, respectively. At 7wk, HF-fed animals exhibited several immune alterations (blood leukocyte/neutrophil number, lymph node B-cell proportionality)-effects which were more pronounced in SD rats. Indices of lung injury/inflammation were elevated in all WF-exposed animals at 12wk; however, diet appeared to preferentially impact SD rats at this time point, as several inflammatory markers (lymph node cellularity, lung neutrophils) were further elevated in HF over Reg animals. Overall, SD rats exhibited the greatest capacity for recovery by 24wk. In BN rats, resolution of immune alterations was further compromised by HF diet, as many exposure-induced alterations in local/systemic immune markers were still evident in HF/WF animals at 24wk. Collectively, HF diet appeared to have a greater impact on global immune status and exposure-induced lung injury in SD rats, but a more pronounced effect on inflammation resolution in BN rats. These results illustrate the combined impact of genetic, lifestyle, and environmental factors in modulating immunological responsivity and emphasize the importance of the exposome in shaping biological responses.

Effects of pulmonary exposure to chemically-distinct welding fumes on neuroendocrine markers of toxicity.

Exposure to welding fumes may result in disorders of the pulmonary, cardiovascular, and reproductive systems. Welders are also at a greater risk of developing symptoms similar to those seen in individuals with idiopathic Parkinson's disease. In welders, there are studies that suggest that alterations in circulating prolactin concentrations may be indicative of injury to the dopamine (DA) neurons in the substantia nigra. The goal of these studies was to use an established model of welding particulate exposure to mimic the effects of welding fume inhalation on reproductive functions. Since previous investigators suggested that changes in circulating prolactin may be an early marker of DA neuron injury, movement disorders, and reproductive dysfunction, prolactin, hypothalamic tyrosine hydroxylase (TH) levels (a marker of DA synthesis), and other measures of hypothalamic-pituitary-gonadal (HPG) function were measured after repetitive instillation of welding fume particulates generated by flux core arc-hard surfacing (FCA-HS), manual metal arc-hard surfacing (MMA-HS) or gas metal arc-mild steel (GMA-MS) welding, or manganese chloride (MnCl2). Exposure to welding fume particulate resulted in the accumulation of various metals in the pituitary and testes of rats, along with changes in hypothalamic TH and serum prolactin levels. Exposure to particulates with high concentrations of soluble manganese (Mn) appeared to exert the greatest influence on TH activity levels and serum prolactin concentrations. Thus, circulating prolactin levels may serve as a biomarker for welding fume/Mn-induced neurotoxicity. Other reproductive measures were collected, and these data were consistent with epidemiological findings that prolactin and testosterone may serve as biomarkers of welding particulate induced DA neuron and reproductive dysfunction.

Eggshell color in brown-egg laying hens - a review.

The major pigment in eggshells of brown-egg laying hens is protoporphyrin IX, but traces of biliverdin and its zinc chelates are also present. The pigment appears to be synthesized in the shell gland. The protoporphyrin IX synthetic pathway is well defined, but precisely where and how it is synthesized in the shell gland of the brown-egg laying hen is still ambiguous. The pigment is deposited onto all shell layers including the shell membranes, but most of it is concentrated in the outermost layer of the calcareous shell and in the cuticle. Recently, the genes that are involved in pigment synthesis have been identified, but the genetic control of synthesis and deposition of brown pigment in the commercial laying hen is not fully understood. The brown coloration of the shell is an important shell quality parameter and has a positive influence on consumer preference. The extent of pigment deposition is influenced by the housing system, hen age, hen strain, diet, stressors, and certain diseases such as infectious bronchitis. In this article, the physiological and biochemical characteristics of the brown pigment in commercial brown-egg layers are reviewed in relation to its various functions in the poultry industry.

Iron limitation induces motility in uropathogenic E. coli CFT073 partially through action of LpdA.

More than half of women will experience a urinary tract infection (UTI) with most cases caused by uropathogenic Escherichia coli (UPEC). Bacterial swimming motility enhances UPEC pathogenicity, resulting in more severe disease outcomes including kidney infection. Surprisingly, the connection between motility and iron limitation is mostly unexplored despite the lack of free iron available in the host. We sought to investigate a potential connection between iron restriction and regulation of motility in UPEC. We cultured E. coli CFT073, a prototypical UPEC strain, under iron limitation and observed that CFT073 had elevated fliC (flagella) promoter activity, and this iron-specific response was repressed by the addition of exogenous iron. We confirmed increased flagellar expression in CFT073 by measuring fliC transcript, FliC protein, and surface-expressed flagella under iron-limited conditions. Interestingly, known motility regulator flhDC did not have altered transcription under these conditions. To define the regulatory mechanism of this response, we constructed single knockouts of eight master regulators and found the iron-regulated response was lost in crp, arcA, and fis mutants. Thus, we focused on the five genes regulated by all three regulators. Of the five genes knocked out, the iron-regulated motility response was most strongly dysregulated in the lpdA mutant, which also resulted in significantly lowered fitness in the murine model of ascending UTI, both against the WT and a non-motile fliC mutant. Collectively, we demonstrated that iron-mediated motility in CFT073 is partially regulated by lpdA, which contributes to the understanding of how uropathogens differentially regulate motility mechanisms in the iron-restricted host. IMPORTANCE: Urinary tract infections (UTIs) are ubiquitous and responsible for over five billion dollars in associated health care costs annually. Both iron acquisition and motility are highly studied virulence factors associated with uropathogenic Escherichia coli (UPEC), the main causative agent of uncomplicated UTI. This work is innovative by providing mechanistic insight into the synergistic relationship between these two critical virulence properties. Here, we demonstrate that iron limitation has pleiotropic effects with consequences that extend beyond metabolism and impact other virulence mechanisms. Indeed, targeting iron acquisition as a therapy may lead to an undesirable enhancement of UPEC pathogenesis through increased motility. It is vital to understand the full breadth of UPEC pathogenesis to adequately respond to this common infection, especially with the increase of antibiotic-resistant pathogens.

The location of protoporphyrin in the eggshell of brown-shelled eggs.

Protoporphyrin has been identified as the main eggshell pigment in brown-shelled eggs. However, there has been some uncertainty concerning the distribution of the pigment within the shell (and cuticle) in brown-shelled eggs. Most previous studies have suggested that the bulk of the shell pigment is deposited in the cuticle of the shell. The present study measured the levels of protoporphyrin in intact eggshells and in shells from which the cuticle had been removed, using eggs from flocks at 3 different ages. This enabled the calculation of the relative amount of protoporphyrin in the calcareous eggshell and the cuticle layer of the eggshell. The majority of the protoporphyrin pigment was located in the calcareous part of the eggshell (80-87%) with a minority contained within the cuticle (13-20%). These findings suggest that studies focused on maintenance of shell color in brown-shelled eggs need to consider the stage of egg formation at which the reduction in pigment deposition is occurring.

Altered motility in response to iron-limitation is regulated by lpdA in uropathogenic E. coli CFT073.

More than half of all women will experience a urinary tract infection (UTI) in their lifetime with most cases caused by uropathogenic Escherichia coli (UPEC). Bacterial motility enhances UPEC pathogenicity, resulting in more severe disease outcomes including kidney infection. Surprisingly, the connection between motility and iron limitation is mostly unexplored, despite the lack of free iron available in the host. Therefore, we sought to explore the potential connection between iron restriction and regulation of motility in UPEC. We cultured E. coli CFT073, a prototypical UPEC strain, in media containing an iron chelator. Under iron limitation, CFT073 had elevated fliC (flagella) promoter activity, driving motility on the leading edge of the colony. Furthermore, this iron-specific response was repressed by the addition of exogenous iron. We confirmed increased flagella expression in CFT073 by measuring fliC transcript, FliC protein, and surface-expressed flagella under iron-limited conditions. To define the regulatory mechanism, we constructed single knockouts of eight master regulators. The iron-regulated response was lost in crp, arcA, and fis mutants. Thus, we focused on the five genes regulated by all three transcription factors. Of the five genes knocked out, the iron-regulated motility response was most strongly dysregulated in an lpdA mutant, which also resulted in significantly lowered fitness in the murine model of ascending UTI. Collectively, we demonstrated that iron-mediated motility in CFT073 is regulated by lpdA , which contributes to the understanding of how uropathogens differentially regulate motility mechanisms in the iron-restricted host. Importance: Urinary tract infections (UTIs) are ubiquitous and responsible for over five billion dollars in associated health care costs annually. Both iron acquisition and motility are highly studied virulence factors associated with uropathogenic E. coli (UPEC), the main causative agent of uncomplicated UTI. This work is innovative by providing mechanistic insight into the synergistic relationship between these two critical virulence properties. Here, we demonstrate that iron limitation has pleiotropic effects with consequences that extend beyond metabolism, and impact other virulence mechanisms. Indeed, targeting iron acquisition as a therapy may lead to an undesirable enhancement of UPEC pathogenesis through increased motility. It is vital to understand the full breadth of UPEC pathogenesis to adequately respond to this common infection, especially with the increase of antibiotic resistant pathogens.

Extraesophageal gastroesophageal reflux disease (GERD) symptoms are not more frequently associated with proximal esophageal reflux than typical GERD symptoms.

Extraesophageal (EE) symptoms such as cough and throat clearing are common in patients referred for reflux testing, but are less commonly associated with gastroesophageal reflux disease (GERD). Patients with reflux associated EE symptoms often lack typical GERD symptoms of heartburn and regurgitation. Our aim was to compare the frequency of proximal esophageal reflux between esophageal (typical) symptoms and EE (atypical) symptoms. Combined multichannel intraluminal impedance-pH (MII-pH) tracings were blinded by an investigator so that symptom markers were relabeled with a number without disclosure of symptom type. We selected 40 patients with at least five reflux-related symptom events for one of four symptoms (heartburn, regurgitation, cough, or throat clearing). A blinded investigator analyzed all 200 reflux episodes, reporting the proximal esophageal extent of the reflux for all symptoms. The percentage of symptom-related reflux extending proximally to 17 cm above the LES was similar among all four symptom types. At least 50% of all symptoms were associated with proximal esophageal reflux to 17 cm, with regurgitation having the highest frequency at 60%. Our data indicate that EE symptoms are not more frequently associated with proximal esophageal reflux than typical esophageal symptoms.

Recovery of Salmonella from eggshell wash, eggshell crush, and egg internal contents of unwashed commercial shell eggs in Australia.

The experiment was conducted to study the prevalence of Salmonella spp. on the eggshell surface, eggshell membranes or pores, and in egg internal contents from unwashed eggs collected from commercial caged layer farms in Australia. Eggshell rinsate, shell crush, and egg internal contents (yolk and albumen) of eggs were processed for Salmonella spp. Salmonella Infantis and Salmonella subspecies 1, serotype 4,12:d were isolated from the eggshell surface. Salmonella spp. were not isolated from any eggshell crush or egg internal contents. It would appear that the occurrence of Salmonella in the Australian egg industry is low.

Zinc hydroxychloride supplementation improves tibia bone development and intestinal health of broiler chickens.

This study was conducted to investigate the effects of zinc (Zn), as a combination of oxide (ZnO) and sulfate (ZnSO4), compared with incremental levels of zinc hydroxychloride (ZH) on tibia traits, intestinal integrity, expression of selected jejunal genes, cecal short chain fatty acids and microbial composition in broilers. Day-old male Ross 308 chicks (n = 784) were randomly allocated to seven dietary treatments, each replicated seven times with 16 chicks per replication. The dietary treatments included a negative control diet (NC) with no supplemental Zn, a positive control (PC) with 100 mg/kg supplemental Zn from an ionic bound source combination (50 mg/kg ZnO + 50 mg/kg ZnSO4), and the NC diet supplemented with one of 20, 40, 60, 80, or 100 mg/kg Zn as ZH. The diets were fed over starter (1-14 d) and grower (14-35 d) phases, with tissue and digesta samples collected from 3 birds per replicate on days 14 and 35. The results showed that dietary Zn level had a significant effect on tibia breaking strength on d 35 (P < 0.05), and tibia Zn concentration both on d 14 and d 35 (P < 0.01). Dietary Zn levels linearly (P < 0.01) increased cecal lactic acid production, increased Lactobacillus, and decreased Bacillus and total bacteria counts (P < 0.05). Inclusion of 80 and 100 mg/kg Zn as ZH tended to upregulate the expression of claudin-1 (P = 0.088) and tight junction protein-1 (P = 0.086). The results obtained in this study suggest that a non-Zn supplemented diet can negatively influence tibia development and gut microbiota composition in broiler chickens. Higher supplemental Zn in the diet alters cecal microbiota population in favor of Lactobacillus and can decrease the total bacterial load. Supplemental Zn level in the feed have the potential to manipulate the jejunal gut integrity at a molecular level.

Detection of infectious bronchitis virus strain N1/88 from the oviduct and feces of experimentally infected vaccinated and unvaccinated hens.

Hens were vaccinated during the rearing phase with infectious bronchitis virus (IBV) vaccines commercially available in Australia (Vic S and A3) or left unvaccinated and then challenged with the N1/88 strain of IBV at 30 wk of age. Oviduct and fecal samples were collected at regular intervals after N1/88 challenge. A locked nucleic acid probe-based reverse transcription real-time PCR test was designed and used to detect the IBV strain N1/88 from the oviduct and feces of unvaccinated and vaccinated laying hens. Using a recombinant plasmid standard, the detection limit of the reaction was found to be 100 copies and independent assay runs showed reproducible threshold cycle values. Viral RNA was detected in the oviduct of 12 unvaccinated then challenged hens and viral RNA increased sharply on d 10 and 12 postinfection (p.i.). By contrast, among the hens in the vaccinated group, N1/88 was detectable only in the oviduct of 2 hens at 8 and 12 d p.i. N1/88 challenge. Viral RNA was detected in feces of 2 unvaccinated hens up to 4 wk p.i. and in 1 vaccinated hen up to 3 wk p.i. This shows that rearing phase vaccination lowers the total viral RNA of the strain N1/88, even though this strain shows considerable antigenic and genetic variation from the vaccine strain. This new test will be useful for the rapid identification of the N1/88 strain of IBV from oviduct and fecal samples.

Evaluation of an intervention targeting loneliness and isolation for older people in North Wales.

AIMS: Age Cymru Gwynedd and Môn provided a service, Cadwyn Môn, which aimed to reduce loneliness and isolation of older people living on Anglesey, North Wales. It involved working with individuals to identify goals, beginning on a one-to-one basis, with the aim of integrating into a wider social setting. The aim of this study was evaluate the impact of Cadwyn Môn on those who received the service. METHODS: The evaluation adopted a mixed-methods design. Standardized measures of loneliness, social isolation and well-being were obtained at baseline and follow-up time points, and a qualitative element explored client experiences further. RESULTS: Improvements were observed in all standardized measures. Qualitative interviews also revealed important psychological and lifestyle changes. CONCLUSIONS: Given the anticipated rise in loneliness and social isolation alongside an ageing population, this evaluation contributes to understanding the qualities required for interventions to be effective. The findings provide support for the importance of developing individualized interventions that aim to gradually re-integrate people into their communities.

Copper hydroxychloride is more efficacious than copper sulfate in improving broiler chicken's growth performance, both at nutritional and growth-promoting levels.

This study was designed to compare the effects of nutritional and growth-promoting levels of copper hydroxychloride (CH) with copper sulfate (CuSO4) on growth, carcass characteristics, tibia traits and mineral concentration in broilers fed a conventional wheat-soybean meal-based diet. Day-old Ross 308 male chicks (n = 864) were randomly assigned into 8 dietary treatments with 6 replicates of 18 chicks per treatment. The dietary treatments included a basal diet containing no supplemental copper (Cu) serving as the negative control (NC); basal diet supplemented with 15 or 200 mg/kg Cu as CuSO4; basal diet supplemented with either 15, 50, 100, 150, or 200 mg/kg Cu from CH. Diets were fed over the starter (day 1-14) and grower (day 14-35) phases. Birds in the NC group gained the same body weight and had similar feed conversion ratio (FCR) to birds receiving 15 mg/kg Cu as CuSO4, but birds receiving 15 mg/kg Cu as CH had a lower FCR than the NC birds (day 0-35; P < 0.05). Birds fed 200 mg/kg Cu as CH gained more weight (77 g/bird) and had a lower FCR (3.2 point) compared with those fed 200 mg/kg Cu as CuSO4 (P < 0.01). Based on broken-line regression models, the optimum inclusion level of Cu as CH in the diet for optimal body weight gain and FCR were estimated to be 109.5 and 72.3 mg/kg, respectively (P < 0.001). Carcass characteristics were not affected by dietary Cu sources or levels (P > 0.05). The highest and lowest tibia ash content were observed in birds fed diet with 150 mg/kg Cu as CH and 200 mg/kg Cu as CuSO4, respectively (P < 0.05). Supplementation with 200 mg/kg Cu as CH resulted in higher duodenal mucosa Cu content compared with the diet containing 200 mg/kg Cu as CuSO4 (P < 0.001). In conclusion, supplementation of Cu from CH was more efficacious than CuSO4 in promoting growth performance, both at nutritional and pharmacological levels.

Evaluation of the skin-sensitizing potential of gold nanoparticles and the impact of established dermal sensitivity on the pulmonary immune response to various forms of gold.

Gold nanoparticles (AuNP) are largely biocompatible; however, many studies have demonstrated their potential to modulate various immune cell functions. The potential allergenicity of AuNP remains unclear despite the recognition of gold as a common contact allergen. In these studies, AuNP (29 nm) dermal sensitization potential was assessed via Local Lymph Node Assay (LLNA). Soluble gold (III) chloride (AuCl3) caused lymph node (LN) expansion (SI 10.9), whereas bulk particles (Au, 942 nm) and AuNP did not. Next, the pulmonary immune effects of AuNP (10, 30, 90 µg) were assessed 1, 4, and 8 days post-aspiration. All markers of lung injury and inflammation remained unaltered, but a dose-responsive increase in LN size was observed. Finally, mice were dermally-sensitized to AuCl3 then aspirated once, twice, or three times with Au or AuNP in doses normalized for mass or surface area (SA) to assess the impact of existing contact sensitivity to gold on lung immune responses. Sensitized animals exhibited enhanced responsivity to the metal, wherein subsequent immune alterations were largely conserved with respect to dose SA. The greatest increase in bronchoalveolar lavage (BAL) lymphocyte number was observed in the high dose group - simultaneous to preferential expansion of BAL/LN CD8+ T-cells. Comparatively, the lower SA-based doses of Au/AuNP caused more modest elevations in BAL lymphocyte influx (predominantly CD4+ phenotype), exposure-dependent increases in serum IgE, and selective expansion/activation of LN CD4+ T-cells and B-cells. Overall, these findings suggest that AuNP are unlikely to cause sensitization; however, established contact sensitivity to gold may increase immune responsivity following pulmonary AuNP exposure.

LNA probe-based real-time RT-PCR for the detection of infectious bronchitis virus from the oviduct of unvaccinated and vaccinated laying hens.

In the present study, LNA-probe based real-time PCR was designed for the detection and absolute quantification of infectious bronchitis virus (IBV) from the oviduct of unvaccinated and vaccinated hens after IBV challenge. Using a recombinant plasmid standard, the detection limit of the reaction was found to be 10 copies and independent assay runs showed reproducible Ct values. Amongst the unvaccinated hens, the virus could be detected between 6 and 20 days post-infection (p.i.), with a peak of viral load between 10 and 14 days p.i. The virus was also detectable in the oviduct of vaccinated, challenged hens although the viral load was much lower compared to the viral load in the oviduct of unvaccinated, challenged hens. This indicates that rearing phase vaccination can offer significant protection of the fully functional oviduct against a pathogenic strain of IBV. The present test will be useful for the rapid identification of IBV directly from clinical samples. Most vaccination trials investigating the efficacy of vaccines for layer and breeder hens have been conducted based on the respiratory tract response. Evaluation of viral load from the oviduct of vaccinated and unvaccinated hens is an efficient method for assessing oviduct protection in commercial laying hens.

Kidney function in the Spinifex hopping mouse, Notomys alexis.

Notomys alexis (Spinifex hopping mouse) is found in the arid zone of Australia. The structure and function of the kidneys allow this species to conserve water. This study investigated the rate at which N. alexis can reduce urine volume and increase the concentration of electrolytes and solutes when water deprived. It also looked at the response to rehydration, following a period of water deprivation. The laboratory mouse, Mus musculus domesticus, was used for comparison. N. alexis is able to reduce urine volume and increase urine concentration more rapidly than M. m. domesticus when water deprived. This appears to occur prior to any measurable changes in plasma electrolyte concentrations and is not due to reductions in glomerular filtration rate. Gradual water deprivation over a period of 10 days allowed N. alexis to adjust so that urine composition was similar in many ways to animals that had ad libitum access to water, whereas M. m. domesticus required significant water supplementation to maintain body weight at 85% of initial body weight. Ability to concentrate urine rapidly is characteristic of a well-insulated renal medulla [Bankir, L., DeRouffignac, C., 1985. Urinary concentrating ability: insights from comparative anatomy. Am. J. Physiol. 249, R643-666]. However, a well-insulated medulla is normally associated with slow dilution of urine when animals are rehydrated. N. alexis was able to produce dilute urine very rapidly following rehydration of water deprived animals. Physiological control of renal function appears to be complex. Although M. m. domesticus is able to produce concentrated urine, it is unable to survive without free water and responds more slowly to water deprivation.

Human factor VIII procoagulant protein. Monoclonal antibodies define precursor-product relationships and functional epitopes.

The human Factor VIII procoagulant protein (VIII:C) purified from commercial Factor VIII concentrate consisted of a polypeptide doublet of 80,000 mol wt, a 92,000-mol wt polypeptide, and additional polypeptides of up to 188,000 mol wt. Thrombin digests contained a doublet of 72,000 mol wt, as well as 54,000- and 44,000-mol wt fragments. Proteolysis studies of purified VIII:C using thrombin and activated protein C have suggested that the 92,000- and 80,000 (or 72,000)-mol wt polypeptides comprise activated VIII:C. We have now used seven monoclonal antibodies raised against purified VIII:C to construct a preliminary epitope map of these VIII:C polypeptides. The specific VIII:C polypeptides with which the monoclonal antibodies reacted were determined by immunoblotting of VIII:C onto nitrocellulose sheets after reduced NaDodSO4-polyacrylamide gel electrophoresis. A minimum of five distinct epitopes were defined by these monoclonal anti-VIII:C antibodies. Identification of polypeptides bearing these epitopes allowed localization of distinct thrombin cleavage sites to the 92,000- and 80,000-mol wt chains, helped define polypeptide chain precursor-product relationships, and suggested that both the 92,000- and 80,000-mol wt polypeptides are necessary for VIII:C function. These data and their interpretation are consistent with the published description of the complete primary structure of VIII:C and its thrombin cleavage products. The 92,000- and 80,000-mol wt chains have been located at the amino- and carboxy-terminal ends of the molecule, respectively.

Independent modulation of von Willebrand factor and fibrinogen binding to the platelet membrane glycoprotein IIb/IIIa complex as demonstrated by monoclonal antibody.

In this study we have used two new monoclonal antibodies, designated LJP5 and LJP9, as well as a previously described one, AP2, all specific for the platelet membrane glycoprotein (GP)IIb/IIIa complex. None of them reacted with dissociated GPIIb or GPIIIa. The monovalent Fab fragment of both LJP5 and LJP9 bound to unstimulated platelets in a saturable manner, but binding was markedly decreased after platelets had been incubated at 37 degrees C in the absence of added extracellular calcium. The binding of LJP9 was not affected by AP2, but was blocked by excess LJP5. On the contrary, the binding of LJP5 was blocked in the presence of both AP2 and LJP9. Thus, these antibodies bound to distinct epitopes of GPIIb/IIIa. At saturation, the binding to unstimulated platelets was between 2.41 and 10.9 X 10(4) molecules/platelet for LJP5 and between 3.47 and 9.1 X 10(4) molecules/platelet for LJP9 (range of 11 and 10 experiments, respectively). Binding increased up to 50% after thrombin stimulation. The estimated association constant, Ka, was 2.7 X 10(7) M-1 for LJP5 and 3.85 X 10(7) M-1 for LJP9. Both LJP5 and LJP9 partially inhibited the association of 45Ca2+ with the surface of unstimulated platelets. Moreover, both antibodies blocked the binding of von Willebrand factor (vWF) to stimulated platelets, whereas only LJP9, but not LJP5, blocked fibrinogen binding. LJP9 was also a potent inhibitor of platelet aggregation, whereas LJP5 was without effect in this regard. The results of the present study demonstrate that independent modulation of vWF and fibrinogen binding to stimulated platelets can be attained with monoclonal antibodies directed against distinct epitopes of GPIIb/IIIa.

Ultrastructural study of infectious bronchitis virus infection in infundibulum and magnum of commercial laying hens.

The infundibulum and magnum of the oviduct were examined in hens in full lay which were infected with two Australian strains of infectious bronchitis virus (IBV). The ultramicroscopic changes in the infundibulum and magnum were compared with control hens which had eggs at different positions in the oviduct. The ciliated and granular cells of the surface epithelia and secretory epithelial cells of the tubular glands were the target cells of IBV. No pathological changes were recorded during 2-8 days post-infection (p.i.). Patchy loss of cilia occurred at 10-14 days p.i. Between 16 and 24 days p.i., there was no cilia loss and lymphoid nodules were observed in the muscularis layer of the infundibulum and magnum of some hens from both infected groups. Virus particles were detected mostly in the rough endoplasmic reticulum (RER) and Golgi complex between 10 and 12 days p.i. Cytopathology was noticed in various cell organelles between the 10th and 14th days p.i. There was an increase in RER deposits in infected cells, irrespective of egg position in the oviduct. The magnum was more affected than the infundibulum. Cellular changes were more severe in the infundibulum and magnum of T-infected hens as compared to N1/88-infected hens. Eggs with watery whites which were laid by infected hens could be attributed to cytopathological changes in the granular epithelial cells and tubular gland epithelial cells of the magnum resulting in reduced synthesis of albumen proteins. IBV can cause pathology in parts of the fully functional oviduct which may persist up to the 30th day p.i. However, both the challenge strains of IBV can cause a small number of hens to cease production. Loss of cilia in both the infundibulum and magnum pose a potential threat of secondary bacterial infection and also may affect fertility in breeder hens.

Ultrastructural observations on effects of infectious bronchitis virus in eggshell-forming regions of the oviduct of the commercial laying hen.

The pathogenesis of 2 strains of infectious bronchitis virus (T and N1/88 strains) was studied in the eggshell-forming regions of the oviduct of commercial laying hens. There were no external shell deformities, except for paler shells. There was no decline in egg production in either of the infected groups. One hen from the N1/88-infected group and 2 hens from the T-infected group were out of lay. The light, scanning, and transmission electron microscopic changes in infected shell-forming regions of the oviduct were compared with the control oviducts at different egg positions. The ultrastructural finding revealed that the extent of cytopathology in the isthmus was greater than in the tubular shell gland and shell gland pouch. The T strain of infectious bronchitis virus was more pathogenic compared with the N1/88 strain. Severe cytopathology was recorded in the shell-forming region of hens that were out of production, and virus particles were observed in hens that had stopped laying. Virus particles were recorded in the dilated rough endoplasmic reticulum and Golgi complex of the isthmus, tubular shell gland, and shell gland pouch of all 3 hens that had stopped laying. Although a decrease in egg production and deterioration in eggshell quality were not observed in this trial, cessation of egg production in a small number of hens could be due to severe cytopathology in the eggshell-forming regions of the oviduct.

Comparative histopathology of two serotypes of infectious bronchitis virus (T and n1/88) in laying hens and cockerels.

The comparative and sequential histopathology of different tissues of unvaccinated laying hens and cockerels were studied in chickens exposed to T and N1/88 strain of infectious bronchitis virus (IBV). The Harderian gland and trachea of hens and cockerels in both T- and N1/88-infected groups were damaged to a similar extent. The cecum was unaffected for both strains of IBV in both hens and cockerels. The sequential histopathological changes in hens revealed that IBV multiplies initially in the Harderian gland, then in the tracheal mucosa and simultaneously in the kidney and regions of the oviduct such as the magnum, tubular shell gland, and shell gland pouch. In cockerels, IBV multiplies first in the Harderian gland, then simultaneously in the trachea and kidney. Overall, the severity and persistence of lesions were greater in the kidneys of T-infected hens as compared with N1/88-infected hens. However, pathological changes in the kidney were mild in T- and N1/88-infected cockerels.