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2.
Case Rep Infect Dis ; 2013: 293823, 2013.
Article in English | MEDLINE | ID: mdl-24383017

ABSTRACT

Background. Coinfection with human immunodeficiency virus (HIV) and syphilis has been occurring at increasing rates, with the greatest increases being seen among men who have sex with men. Secondary syphilis rarely presents with liver disease, and the diagnosis may be overlooked in favor of more common causes of liver injury in this setting, such as viral hepatitis, antiretroviral therapy, alcohol use, and opportunistic infections. Case Presentation. We describe a 43-year-old patient with HIV who presented with symptoms suggesting acute pancreatitis. Investigation led to a diagnosis of hepatitis and pancreatitis, both attributed to syphilis. Conclusion. Syphilis should be included as part of the initial diagnosis among patients with HIV presenting with abnormal liver and pancreatic enzymes.

3.
Avian Dis ; 57(4): 716-29, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24597113

ABSTRACT

Ernest Edward Tyzzer (1875-1965) was a physician, specializing at first (1902-1916) in cancer research and then from 1916 as a parasitologist. He was born of English parents in Wakefield, Massachusetts, where he lived all his life. Educated in Wakefield public schools, Brown University (Ph.B., A.M., Hon. Sc.D.), and Harvard University (M.D.), he established during his 40-yr career (1902-1942) an international reputation in oncology, pathology, virology, bacteriology, parasitology, and taxonomic zoology in relation to human and veterinary medicine. His contributions to knowledge of avian diseases were outstanding and wide-ranging. Seminal work included: new descriptions of tumors in chickens; the first record of Cryptosporidium in birds; studies on the biology, morphology, in vitro culture, and epizootiology of the blackhead (histomonosis) parasite and its reclassification under a new genus Histomonas; descriptions of eight new taxa of amebae and flagellates in chickens, turkeys, and ruffed grouse; descriptions of seven new species of Eimeria in chickens, turkeys, pheasants, and quail as well as studies on their biology, immunogenicity, virulence, and epizootiology; a description of the trematode Collyriclum in English sparrows; the first record of mycosis in ruffed grouse; the recognition of birds as a source of equine encephalomyelitis infections of humans; the first American record of infectious sinusitis in turkeys and discovery of a curative treatment; and studies of Newcastle disease and avian influenza during the war research program of the 1940s. Application of Tyzzer's histomonosis research to farm practice saved the Massachusetts turkey industry from extinction in the 1920s and significantly influenced the recovery of turkey farming nationally.


Subject(s)
Animal Husbandry/history , Bird Diseases/history , Bird Diseases/parasitology , Eukaryota/classification , Eukaryota/physiology , Animal Husbandry/economics , Animal Husbandry/methods , Animals , Bird Diseases/diagnosis , Birds , Eukaryota/cytology , Eukaryota/pathogenicity , History, 20th Century , Protozoan Infections, Animal/parasitology , United States
4.
Poult Sci ; 89(9): 1788-801, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20709963

ABSTRACT

In July 1971, the polyether ionophorous antibiotic monensin was introduced in the United States for the control of coccidiosis in poultry. At that time, prospects for new anticoccidial agents were not good. Amprolium had enjoyed several years of use, but many other compounds had been abandoned as resistance to them developed. After the introduction of monensin, most commercial broilers were medicated with the drug and it is still widely used for this purpose today. Apart from in poultry, monensin is also used to control coccidiosis in game birds, sheep, and cattle. Indeed, more animals have been medicated with ionophores, such as monensin, for control of disease than any other medicinal agents in the history of veterinary medicine. In this review, we discuss the discovery, mode of action, and efficacy of monensin, together with matters of importance to the poultry industry such as commercial use, drug resistance, toxicity, pharmacology and residues, host immunity to coccidiosis, and effects in other avian species.


Subject(s)
Coccidiosis/veterinary , Coccidiostats/therapeutic use , Monensin/therapeutic use , Poultry Diseases/drug therapy , Animals , Coccidiosis/drug therapy , Drug Resistance , Monensin/chemistry , Monensin/pharmacology , Poultry
5.
Neurogastroenterol Motil ; 22(4): 381-6, e89, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20377793

ABSTRACT

BACKGROUND: Inappropriate or excessive, non-swallow related, reflexive relaxation of the upper esophageal sphincter (UES) in response to esophageal distension may be the principal mechanism permitting retrograde trans-sphincteric flow during acid regurgitation. The neural pathways mediating reflexive UES relaxation in the human have received little attention. Patients with laryngitis demonstrate an increased acid reflux in the proximal esophagus. Such events, combined with an increased tendency for UES relaxation, might precipitate regurgitation into the pharynx. The aim was to determine whether the esophago-UES relaxation reflex induced by rapid esophageal distension is upregulated in patients with posterior laryngitis. METHODS: In 21 healthy volunteers and 14 patients with posterior laryngitis, UES responses to rapid air insufflation were examined. UES responses were monitored with perfused manometry catheter with a oval sleeve sensor. KEY RESULTS: The probability of triggering UES relaxation in response to the rapid esophageal air distension, for all volumes of insufflation, was higher in laryngitis (45%) than in health (17%). The minimum distension volume required to elicit an UES relaxation response was significantly lower in laryngitis patients when compared with controls. Patients who demonstrated a laryngoscopic response to a trial of omeprazole, were less likely to generate a distension-induced UES contractile response (5%) than patients who did not respond (23%). CONCLUSIONS & INFERENCES: The threshold for esophageal distension-induced UES relaxation is reduced in patients with laryngitis when compared with controls. This finding supports the hypothesis that in this population, a hypersensitive belch-like response may be one contributory mechanism of regurgitation when triggered by an abrupt spontaneous gastro-esophageal reflux event.


Subject(s)
Esophageal Sphincter, Upper/physiopathology , Esophagus/physiopathology , Laryngopharyngeal Reflux/physiopathology , Muscle Relaxation/physiology , Adult , Aged , Anti-Ulcer Agents/therapeutic use , Female , Humans , Laryngopharyngeal Reflux/drug therapy , Laryngoscopy , Male , Manometry , Middle Aged , Omeprazole/therapeutic use , Patient Selection , Peristalsis/physiology , Pharynx/physiopathology , Severity of Illness Index , Surveys and Questionnaires , Treatment Outcome
6.
Syst Parasitol ; 76(1): 69-76, 2010 May.
Article in English | MEDLINE | ID: mdl-20401580

ABSTRACT

Preservation of the exogenous oöcyst stage of coccidian parasites (phylum Apicomplexa N.D. Levine, 1970) as type-specimens of newly described species has long been problematical. Conventional fixatives have proved unsatisfactory, and compromises such as embedding oöcysts in resin or photographing them are not entirely appropriate for various reasons. As an alternative, chilled potassium dichromate solution (normally used in the laboratory to prevent putrefaction of temporary preparations of live oöcysts) has been tested as a long-term preservative of sporulated oöcysts of Eimeria brunetti P.P. Levine, 1942, E. maxima Tyzzer, 1929, E. mitis Tyzzer, 1929, E. necatrix Johnson, 1930, E. praecox Johnson, 1930 and E. tenella (Railliet & Lucet, 1891) (suborder Eimeriorina Léger, 1911; family Eimeriidae Minchin, 1903). Oöcysts from faeces of chickens Gallus gallus (Linnaeus) were placed in 2.5% w/v aqueous potassium dichromate solution (PDS) and stored in the dark at 4 +/- 2 degrees C. After 23 years in storage, oöcysts of each species were administered orally to chickens and failed to initiate infections, indicating that the oöcysts were dead. Nevertheless, after about 24 years, DNA was still recoverable from the oöcysts, and the original species identifications made by classic parasitological methods were confirmed by polymerase chain reaction assays. Furthermore, after almost 25 years, microscopical examination revealed that the walls and internal structures remained well preserved in 83-98% of the oöcysts of the six species investigated. Hence, PDS is potentially suitable for the long-term preservation of sporulated coccidian oöcysts as type-specimens for taxonomic purposes. The samples used in this study are now in the care of the Natural History Museum, London, UK. It is recommended that they be monitored in like manner, by suitably qualified scientists, at intervals of about 5 years to assess their state of preservation and the recoverability of DNA. Enough material is available to monitor it until it is at least 100 years old.


Subject(s)
Chickens/parasitology , DNA, Protozoan/genetics , Eimeria/genetics , Parasitology/methods , Preservation, Biological/methods , Spores, Protozoan/genetics , Animals , Eimeria/isolation & purification , Feces/parasitology , Fixatives/pharmacology , Polymerase Chain Reaction , Potassium Dichromate/pharmacology , Time Factors
7.
Syst Parasitol ; 76(1): 77-9, 2010 May.
Article in English | MEDLINE | ID: mdl-20401581

ABSTRACT

The coccidian Eimeria meleagridis Tyzzer, an apicomplexan parasite of the turkey, was long believed to be innocuous, but recent research suggests that it may be of greater economic importance than previously realised. Hitherto, the date of publication of both the name and the original species description has invariably been wrongly cited as 1927, an error first committed by the describer himself and perpetuated ever since. In fact, the name as published in 1927 was a nomen nudum, being unaccompanied by any indication or description. Tyzzer's first valid publication of the name with a description was two years later. Hence the correct formal authorship attribution is Eimeria meleagridis Tyzzer, 1929.


Subject(s)
Chronology as Topic , Eimeria/classification , Terminology as Topic , Animals , Turkeys/parasitology
8.
Avian Pathol ; 38(5): 359-66, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19937523

ABSTRACT

The pathogenesis in chickens of the apicomplexan Eimeria praecox was compared with that of Eimeria acervulina, using intestinal lesions, mucosal integrity, body weight gain (BWG) and the feed conversion ratio (FCR) as criteria. Characteristics of each species were described by combinations of polymerase chain reaction assays and classic parasitological signs. There were considerable overlaps in lengths, breadths, shape indices and volumes of the oocysts of each species. Both species caused statistically significant reductions in BWG at the lowest inocula tested (500,000 sporulated oocysts per bird of E. praecox and 250,000 of E. acervulina). E. praecox was observed for the first time to cause actual body weight loss and marked increases in FCR, as did E. acervulina. E. acervulina caused gross, white pathognomonic lesions, but E. praecox caused micro-lesions, visible in fresh tissue only with a dissecting microscope. Occasionally, lesions of the Houghton strain of E. acervulina were observed to be rounded, rather than typically "ladder-like". Both species caused villous erosion and atrophy. No mortality occurred in birds receiving up to 1 million sporulated oocysts of either species. Using BWG and FCR as criteria, the virulence of recent field strains of E. praecox from Wales (Tynygongl) and the USA (Raleigh) was compared with English laboratory strains of E. praecox (Houghton) and E. acervulina (Houghton). E. praecox (Tynygongl) was markedly more virulent than E. acervulina (Houghton), which was more virulent than E. praecox (Raleigh) and E. praecox (Houghton).


Subject(s)
Coccidiosis/veterinary , Eimeria/pathogenicity , Poultry Diseases/parasitology , Animals , Chickens , Coccidiosis/parasitology , Coccidiosis/pathology , Coccidiosis/physiopathology , DNA, Protozoan , Eimeria/classification , Eimeria/genetics , Intestinal Mucosa/pathology , Intestines/pathology , Oocysts/parasitology , Poultry Diseases/pathology , Poultry Diseases/physiopathology , United States , Virulence , Wales
9.
Psychophysiology ; 46(4): 862-9, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19470128

ABSTRACT

Positive affect was examined as a predictor of (1) cardiovascular reactivity during a sadness and an anger recall task and recovery following the protocol, (2) epinephrine (EPI) and norepinephrine (NOREPI) reactivity and level during the recall protocol, and (3) the diurnal pattern of salivary cortisol. Sample was 328 individuals. Negative affect, age, race, sex, smoking status, income, and BMI were adjusted. During sadness recall, positive affect was inversely related to systolic blood pressure (p=.007) and diastolic blood pressure (p=.049) reactivity, and unrelated to heart rate (p=.226). Positive affect was unrelated to reactivity during anger recall (ps>.19), and was unrelated to recovery at the end of the recall protocol. Positive affect was inversely related to the mean level of NOREPI (p=.046), and unrelated to EPI (p=.149). Positive affect was inversely related to the increase in cortisol 30 min post awakening (p=.042), and unrelated to the evening decline in cortisol levels (p=.174). Positive emotions may be relevant to good health.


Subject(s)
Affect/physiology , Hemodynamics/physiology , Hydrocortisone/metabolism , Norepinephrine/blood , Saliva/chemistry , Adult , Body Mass Index , Circadian Rhythm/physiology , Female , Humans , Male , Socioeconomic Factors
11.
Microbes Infect ; 9(1): 87-95, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17194612

ABSTRACT

The control of mycobacterial infections is dependent on the finely tuned synergism between the innate and adaptive immune responses. The macrophage is the major host cell for Mycobacterium tuberculosis and the degree of virulence of mycobacteria may influence the initial macrophage response to infection. The cell wall molecule, phthiocerol dimycocerosate (DIM), is an important virulence factor that influences the early growth of M. tuberculosis in the lungs. To explore the basis for this effect we have compared the early gene response of human THP-1 macrophages to infection with virulent M. tuberculosis and the DIM-deficient DeltafadD26 M. tuberculosis strain using microarrays. Detailed analysis revealed a common core of macrophage genes, which were rapidly induced following infection with both strains, and deficiency of DIM had no significant effect on this initial macrophage transcriptional responses. In addition to chemokines and pro-inflammatory cytokines, the early response genes included components of the Toll-like receptor signalling, antigen presentation and apoptotic pathways, interferon response genes, cell surface receptors and their ligands, including TNF-related apoptosis inducing ligand (TRAIL) and CD40, and other novel genes. Therefore, although fadD26 deficiency is responsible for the early attenuation of the growth of M. tuberculosis in vivo, this effect is not associated with differences in the initial macrophage transcriptional response.


Subject(s)
Lipids/deficiency , Macrophages/immunology , Macrophages/physiology , Mycobacterium tuberculosis/immunology , Animals , Antigens, Bacterial/immunology , Cell Line , Female , Flow Cytometry/methods , Humans , Kinetics , Macrophages/microbiology , Mice , Mice, Inbred C57BL , Mycobacterium tuberculosis/genetics , Mycobacterium tuberculosis/pathogenicity , Oligonucleotide Array Sequence Analysis , Reverse Transcriptase Polymerase Chain Reaction/methods , Transcriptional Activation , Virulence Factors/immunology
12.
Vet Parasitol ; 136(3-4): 233-42, 2006 Mar 31.
Article in English | MEDLINE | ID: mdl-16388903

ABSTRACT

For the assessment of coccidial oocyst production by chickens, some modified form of the McMaster counting method is commonly used. The objective of this study was to evaluate a standard method and to compare it to a new, faster method, in which all the preparative stages before counting are carried out in the same container into which the original faecal sample was collected. A stock suspension containing purified oocysts of all seven valid Eimeria species that parasitize chickens was prepared, from which seven concentrations of oocyst suspensions were made. Since the faecal material in a sample influences the ability of oocysts to float up in a McMaster chamber, the new method was tested to establish the optimal amount of faeces in the original sample. Control oocyst suspensions containing no faeces were also tested, and three series of counts using the new method were compared with the standard McMaster method. The results were statistically analysed by agreement analysis. Repeatability and between-operator variation of both methods were also tested by agreement analysis. Counting by the standard McMaster method underestimated the true number of oocysts. The new method gave counts in agreement with the true number of oocysts if using 1 g of faeces per sample. With 2 g of faeces, counts were obtained that agreed with counts by the standard McMaster method. Both methods showed agreement between repeated measurements. The new method used on a sample containing 2 g of faeces provides a convenient alternative to the standard modified McMaster method. A 1-g faecal sample increases agreement with the true numbers of oocysts. Processing of a sample with the new method is about nine times faster than with the standard method.


Subject(s)
Chickens , Coccidiosis/veterinary , Eimeria/isolation & purification , Oocysts/isolation & purification , Parasite Egg Count/veterinary , Animals , Coccidiosis/diagnosis , Feces/parasitology , Parasite Egg Count/methods , Poultry Diseases , Reproducibility of Results , Sensitivity and Specificity , Time Factors
13.
Vet Parasitol ; 135(1): 15-23, 2006 Jan 15.
Article in English | MEDLINE | ID: mdl-16361061

ABSTRACT

The virulence of a field strain of the chicken coccidian parasite Eimeria acervulina (Boreham I), dually resistant to the chemically unrelated anticoccidial agents decoquinate and clopidol, was compared with that of a drug-sensitive laboratory strain (Ongar) of the same species. Following a single heavy infection (prevented from recycling), both strains exhibited pathogenic effects typical of their species, viz., pathognomonic lesions, adverse effects on body weight gain and feed conversion ratio (FCR), but no mortality. One week after infection, chicks infected with either strain had a statistically significantly worse weight gain than the uninfected control; the Boreham I strain produced more oocysts, and caused slightly more severe duodenal lesions and poorer FCRs than the Ongar strain (all those effects being non-significant). After 3 weeks, there were no significant differences between any cumulative effects of either strain, nor any differences from the uninfected control. However, from 2 to 3 weeks after infection, chicks infected with either strain had a greater feed consumption and growth rate than uninfected chicks. When chicks reared on solid floors were given lighter infections of either strain, which were allowed subsequently to recycle naturally, there were no consistent reductions in weight gains, but feed consumption was higher than that of uninfected chicks. Whatever, the mode of infection, there were no significant differences between the weights of infected and uninfected chicks after 3 weeks, but the FCR of infected chicks was usually poorer than that of uninfected chicks. The difference between the virulences of the Boreham I and Ongar strains was not greater than that between various drug-resistant strains or between various sensitive strains of several Eimeria species recorded in the literature. It is therefore concluded that there was no difference between the virulences of the two strains of E. acervulina that could be attributed to the drug-resistance of one of them.


Subject(s)
Chickens/parasitology , Coccidiosis/veterinary , Coccidiostats/pharmacology , Eimeria/drug effects , Poultry Diseases/parasitology , Animals , Clopidol/pharmacology , Coccidiosis/drug therapy , Coccidiosis/parasitology , Decoquinate/pharmacology , Drug Resistance/genetics , Eimeria/pathogenicity , Energy Intake , Floors and Floorcoverings , Male , Oocysts/isolation & purification , Poultry Diseases/drug therapy , Random Allocation , Virulence , Weight Gain
14.
Vet Parasitol ; 135(1): 1-14, 2006 Jan 15.
Article in English | MEDLINE | ID: mdl-16289564

ABSTRACT

Decoquinate is a quinolone coccidiostat introduced during 1967 as an in-feed prophylactic for broiler chickens. Despite early drug-resistance problems and its age, the drug is still used commercially worldwide. Decoquinate here serves as a valuable model in a field study that addresses the dynamics and economic impact of the development of coccidial resistance to potent synthetic anticoccidial drugs. The results of this unique, hitherto unpublished, study on the initial emergence of resistance of avian coccidia (Eimeria spp.) to a new drug in the field may be of strategic value in the continued use of decoquinate or the introduction of new drugs. The commercial performance of the first 3-5 crops of broilers to be medicated with decoquinate on each of six farms was monitored during 14 months in 1968-1969, supplemented by assessments of the species, population dynamics and decoquinate-resistance of coccidia isolated from each farm. During the rearing of each flock in a single shed on each farm, oocysts were counted in fresh faecal samples collected on three occasions, and the species were identified by their morphology if possible, supported if necessary by the biological characteristics of infections in chickens. E. acervulina was the most common species, followed by E. mitis, E. maxima, E. tenella and E. praecox. E. brunetti occurred rarely, and E. necatrix was not found. Decoquinate-resistance was evident in several species during the rearing of the first decoquinate-medicated crop on each farm, although clinical coccidiosis did not occur. It was concluded that inherently resistant mutants of E. acervulina, E. brunetti, E. maxima, E. tenella, and probably also E. mitis and E. praecox, were selected from field populations by 6 weeks during their first exposure to decoquinate. During up to four more subsequent crops, cycling of resistant parasites stimulated host immunity, which had no obvious adverse impact on commercial performance. There was no apparent seasonal effect. A hypothesis is proposed to explain the sudden and rapid emergence of quinolone-resistance in the coccidia, and why bird health was not thereby compromised in these circumstances.


Subject(s)
Chickens/parasitology , Coccidiosis/veterinary , Coccidiostats/pharmacology , Decoquinate/pharmacology , Eimeria/drug effects , Poultry Diseases/drug therapy , Animals , Coccidiosis/drug therapy , Coccidiosis/parasitology , Coccidiosis/prevention & control , Coccidiostats/therapeutic use , Decoquinate/therapeutic use , Drug Resistance , Feces/parasitology , Parasite Egg Count/veterinary , Parasitic Sensitivity Tests/veterinary , Poultry Diseases/parasitology , Poultry Diseases/prevention & control , United Kingdom
15.
Opt Lett ; 30(21): 2906-8, 2005 Nov 01.
Article in English | MEDLINE | ID: mdl-16279465

ABSTRACT

A highly elongated double-clad ribbon fiber that comprises a pure-silica inner cladding with transverse dimensions of approximately 1.4 mm by 0.23 mm with a linear array of ten ytterbium-doped cores has been fabricated and operated in a simple laser configuration pumped by two diode stacks. The fiber laser yielded 320 W of output power at a center wavelength of 1045 nm in a combined beam with beam propagation factors of approximately 2 (perpendicular to the array) and approximately 150 (parallel to the array) for 576 W of launched pump power. The slope efficiency with respect to absorbed pump power was 62%. The prospects for further power scaling and improved beam quality and efficiency are discussed.

16.
Avian Pathol ; 34(3): 159-80, 2005 Jun.
Article in English | MEDLINE | ID: mdl-16191699

ABSTRACT

Coccidiosis and necrotic enteritis (NE) are globally common, sometimes intercurrent, diseases of poultry. The risk of NE, due to the Gram-positive bacterium Clostridium perfringens, has increased in recent years because of the voluntary or legally required withdrawal of the use of certain in-feed antibiotic growth promoters with anticlostridial activity. In-feed ionophorous anticoccidial drugs incidentally also possess anticlostridial activity. Such ionophores, although not banned, are usually precluded when live anticoccidial vaccines are used, potentially increasing yet further the risk of NE. This review provides information for the design of rational, integrated management strategies for the prevention and control of coccidiosis and NE in chickens by maintaining gut integrity. Because of differences in local availability of feed ingredients and national legislations regarding antibiotic growth promoters and anticoccidial vaccine licensing, no universal strategy is applicable. The diseases and their interactions are described under the headings of forms of disease, diagnosis, sources of infection, pathophysiological effects, predisposing factors, and control methods. Elements of gut integrity, which influences host predisposition and clinical responses to disease, include physical development, immune competence, gut enzyme activity, mucin production, gut flora and epithelial damage. Experimental studies of coccidiosis and NE are compared, and where possible reconciled, with field observations. Gaps in knowledge and necessary further experiments are identified. Insights are provided regarding interactions between coccidiosis, NE, and the use of live anticoccidial vaccines. Recent changes in NE prevalence in commercial flocks, and their possible causes, are discussed. The necessarily wide range of topics reviewed emphasizes the enormous complexity of this disease combination, and indicates the importance of a multidisciplinary approach in order to reduce its harmful impact on the world's poultry industry.


Subject(s)
Clostridium Infections/veterinary , Coccidiosis/veterinary , Enterocolitis, Necrotizing/veterinary , Poultry Diseases/physiopathology , Animal Husbandry , Animals , Chickens , Clostridium Infections/epidemiology , Clostridium Infections/physiopathology , Clostridium Infections/prevention & control , Coccidiosis/epidemiology , Coccidiosis/physiopathology , Coccidiosis/prevention & control , Diet , Enterocolitis, Necrotizing/epidemiology , Enterocolitis, Necrotizing/physiopathology , Enterocolitis, Necrotizing/prevention & control , Poultry Diseases/epidemiology , Poultry Diseases/prevention & control , Protozoan Vaccines
17.
Avian Pathol ; 34(4): 279-90, 2005 Aug.
Article in English | MEDLINE | ID: mdl-16147563

ABSTRACT

These guidelines are intended to aid those engaged in poultry research in the design, implementation and interpretation of laboratory, floor-pen and field studies for the assessment of the efficacy and safety of live anticoccidial vaccines for immunization of chickens and turkeys against Eimeria species. In addition to efficacy and safety requirements, manufacture, quality control and licensing considerations are discussed. The guidelines do not address subunit vaccines comprising non-viable material, but many of the principles described will be relevant to such vaccines if they are developed in the future. Guidelines are available in some countries for avian vaccines of bacterial or viral origin but specific standards for anticoccidial vaccines in poultry have not, as far as we know, been produced. Information is provided on general requirements of registration authorities (based upon regulations applicable in the European Union and the USA) for obtaining marketing authorizations for vaccines. These guidelines may assist poultry specialists in providing specific information for administrators involved in the decision-making process leading to registration of new vaccines, and are intended to facilitate the worldwide adoption of consistent, standard procedures.


Subject(s)
Clinical Trials as Topic/veterinary , Coccidiosis/veterinary , Drug Approval/methods , Poultry Diseases/prevention & control , Protozoan Vaccines , Animals , Chickens , Clinical Trials as Topic/standards , Coccidiosis/prevention & control , European Union , Protozoan Vaccines/adverse effects , Turkeys , United States
18.
Equine Vet J ; 37(5): 402-11, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16163941

ABSTRACT

REASONS FOR PERFORMING STUDY: The proposed biological mechanisms for exercise-induced pulmonary haemorrhage (EIPH) are many and varied. Better knowledge of risk factors should lead to achievable measures to reduce the incidence. OBJECTIVES: To identify risk factors associated with epistaxis following racing in UK Thoroughbreds, to gain possible insights into the pathogenesis of the condition and to investigate the association between epistaxis and race finishing position. METHODS: The association of epistaxis occurring on UK racecourses between 1996 and 1998 with a wide range of race-, horse- and start-level variables was examined in multivariable mixed effect logistic regression analyses. Four multivariable analyses were conducted, one for all race types considered collectively and one each for flat, hurdle and steeplechase race types considered separately. RESULTS: Risk of epistaxis was significantly increased for hurdle and steeplechase race types compared to both flat and National Hunt flat races. In 3 of the 4 final models, there was a significant biological trend for increasing risk of epistaxis with increasing ground hardness ('going') and accumulated years spent racing. However, in flat races epistaxis was such a rare outcome (0.33 cases per 1000 starts) that this subset analysis had insufficient power to measure the detectable effect of 'going' as statistically significant. Horses with epistaxis were significantly more likely to have a poorer finishing position than those without blood at the nostrils. CONCLUSIONS: Findings were consistent with the theory that locomotory impact-induced trauma contributes to exercise-induced epistaxis. Further validation of this hypothesis through application of similar methods to endoscopically visible EIPH and through biomechanical studies is warranted. POTENTIAL RELEVANCE: Knowledge of significant risk factors should allow formulation of practical measures, such as track watering, to reduce the risks of EIPH and epistaxis in racehorses.


Subject(s)
Epistaxis/veterinary , Horse Diseases/epidemiology , Physical Conditioning, Animal/physiology , Animals , Case-Control Studies , Epistaxis/epidemiology , Epistaxis/etiology , Female , Hemorrhage/epidemiology , Hemorrhage/etiology , Hemorrhage/veterinary , Horse Diseases/etiology , Horses , Logistic Models , Male , Physical Exertion/physiology , Risk Factors , Running/physiology , Seasons
19.
Vet Parasitol ; 129(3-4): 193-207, 2005 May 15.
Article in English | MEDLINE | ID: mdl-15845274

ABSTRACT

The apicomplexan parasite Plasmodium gallinaceum has not been much studied from the veterinary standpoint. Although it causes malaria in domesticated chickens, no effective drugs appear to be commercially available. A mixture of trimethoprim and sulphaquinoxaline (TMP/SQX, ratio 1:3), with a wide spectrum of activity against bacteria and coccidia, is here shown to be also efficacious against blood-induced P. gallinaceum malaria when administered therapeutically in the feed of chickens for 5-day periods, beginning on the day before infection, or on the day of infection, or up to four days after infection. Chickens were protected against mortality and reduction of weight gain. Three other criteria of efficacy, which showed good correlation with each other and also with the two commercial performance criteria, were the production of green diarrhoea (due to biliverdin), parasitaemia and reduced haematocrit values. When TMP/SQX treatments were initiated sooner than five days after infection, parasites were almost entirely eliminated from the blood, whereas treatments initiated later than four days after infection failed to protect birds against clinical disease. Birds protected by TMP/SQX against primary infection with P. gallinaceum were immune to clinical malaria when exposed to a severe blood-induced challenge of P. gallinaceum 28 days later.


Subject(s)
Antimalarials/therapeutic use , Chickens , Malaria, Avian/drug therapy , Plasmodium gallinaceum/growth & development , Poultry Diseases/drug therapy , Poultry Diseases/parasitology , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use , Animals , Diarrhea/drug therapy , Diarrhea/parasitology , Diarrhea/veterinary , Hematocrit/veterinary , Malaria, Avian/parasitology , Male , Parasitemia/drug therapy , Parasitemia/parasitology , Parasitemia/veterinary
20.
Avian Pathol ; 34(1): 29-47, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15763737

ABSTRACT

Data on the effects of Plasmodium gallinaceum on domesticated fowl are sparse, justifying a full investigation of its pathology. Clinical signs following blood-induced infections with the Wellcome line of strain 8A included depression, fever, anorexia, reduced weight gain, poor feed conversion, anaemia, green faeces and often death. After administration of 10(6) erythrocytic parasites, mortality 5 to 10 days after infection was 10% to 93% in chickens 7 to 84 days old. The older the birds, the lower the mortality and the longer the time to death. Onset of detectable parasitaemia occurred mostly during the second day after infection (59% of birds). Peak parasitaemia (approximately 70%) occurred on the sixth day in 85% of surviving birds. The patent period was usually 7 to 19 days. Abnormally low haematocrit values of < or =24% and high colonic temperatures of > or =42 degrees C were recorded. A febrile response is demonstrated conclusively here in P. gallinaceum malaria for the first time. Weight gain of malarious birds was reduced by approximately 18% to 51%, and feed conversion efficiency was often reduced by approximately 12% to 41%. Growth reduction was due entirely to anorexia. Liver weight relative to body weight (normally approximately 2% to 3%) increased to approximately 4.5% by 8 days, and relative spleen weight (normally approximately 0.2%) increased to 1.6% by 12 days. Specific gravities of livers and spleens in healthy and infected birds were approximately 1.09. Gall bladder volume in malarious birds 8 days after infection was approximately four times that of normal birds. Statistically significant changes occurred in the proportions of plasma proteins in malarious birds 8 days after infection; albumin and alpha2-globulin were reduced, while gamma1-globulin and gamma2-globulin were increased. Those changes coincided with significant increases in concentrations of plasma total protein and the enzymes aspartate aminotransferase, glutamate dehydrogenase and gamma-glutamyltransferase, and a decrease in creatinine. Green (biliverdin) colouration of the faeces was a consistent sign of malaria. Birds acquired non-sterile immunity after a single primary infection. The quantitative data presented facilitate selection of the most useful criteria for field diagnosis, estimation of potential economic losses, and assessment of potential avian antimalarial drugs.


Subject(s)
Malaria, Avian/physiopathology , Poultry Diseases/physiopathology , Animals , Body Temperature , Chickens , Feces , Gallbladder/pathology , Hematocrit/veterinary , Liver/pathology , Malaria, Avian/blood , Malaria, Avian/pathology , Male , Organ Size , Parasitemia/veterinary , Poultry Diseases/blood , Poultry Diseases/pathology , Spleen/pathology , Time Factors , Weight Gain
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