Centennial Review: History and husbandry recommendations for raising Pekin ducks in research or commercial production

By some accounts, ducks were domesticated between 400 and 10,000 yr ago and have been a growing portion of the poultry industry for decades. Ducks specifically, and waterfowl in general, have unique health, housing, nutrition and welfare concerns compared to their galliform counterparts. Although there have been many research publications in regards to health, nutrition, behavior, and welfare of ducks there have been very few reviews to provide an overview of these numerous studies, and only one text has attempted to review all aspects of the duck industry, from breeders to meat ducks. This review covers incubation, hatching, housing, welfare, nutrition, and euthanasia and highlights the needs for additional research at all levels of duck production. The purpose of this review is to provide guidelines to raise and house ducks for research as specifically related to industry practices.

Mechanical analysis of transversal iliac fracture stabilization using dynamic compression plate or screws and PMM in polyurethane bone model

ABSTRACT Pelvic fractures correspond to 20 to 30 % of the fractures observed in dogs. Complete fractures, especially with bone axis deviation should be surgically treated. The mechanical study of surgical techniques is of utmost importance to assess the best way of treating these injuries. This study compared, biomechanically, the use of a dynamic compression plate (DCP) and screws (group 1) or screws and polymethylmethacrylate (PMMA) (group 2) to stabilize an iliac fracture using a static test. Sixteen canine synthetic hemi-pelvises (test specimens) with a transverse iliac osteotomy were used. After fixation with implants, a load was applied to the acetabulum until failure. Group 1 maximal compressive load was 133.9±18.60 N, displacement at yield 21.10±3.59mm and stiffness 125.22±12.25N/mm. Group 2 maximal compressive load was 183.50±27.38N, displacement at yield 16.66±5.42mm and stiffness 215.68±33.34N/mm. The stabilization with polymethylmethacrylate was stronger than dynamic compression plate since it resisted a greater load in all test specimens.

The Coalition for Sustainable Egg Supply project: An introduction

In the United States, empirical information on the sustainability of commercial-scale egg production is lacking. The passage of state regulations specific to hen housing created urgency to better understand the effects of different housing systems on the sustainability of the egg supply, and stimulated the formation of a coalition, the Coalition for a Sustainable Egg Supply (CSES), to conduct research on this topic. The CSES is a multi-stakeholder group with 27 members, including food manufacturers, research institutions, scientists, restaurants, food service, retail food companies, egg suppliers, and nongovernmental organizations. A commercial-scale study was developed to better understand the effect of 3 housing systems (conventional cage, enriched colony, and cage-free aviary) on 5 areas related to a sustainable egg supply. These 5 sustainability areas represent effects on people, animals, and the environment: animal health and well-being, environment, food safety, worker health and safety, and food affordability. Five teams of scientists, each associated with a sustainability area, conducted an integrated field study at a commercial site in the upper Midwest through 2 flock cycles in 3 housing systems. This paper provides a brief overview of the CSES project to serve as an introduction for the papers that follow in this volume of Poultry Science.

Site-selective inhibition of plastid RNA editing by heat shock and antibiotics: a role for plastid translation in RNA editing

RNA editing in higher plant plastids changes single cytidine residues to uridine through an unknown mechanism. In order to investigate the relation of editing to physiological processes and to other steps in plastid gene expression, we have tested the sensitivity of chloroplast RNA editing to heat shock and antibiotics. We show that heat shock conditions as well as treatment of plants with prokaryotic translational inhibitors can inhibit plastid RNA editing. Surprisingly, this inhibitory effect is confined to a limited number of plastid editing sites suggesting that some site-specific factor(s) but none of the general components of the plastid RNA editing machinery are compromised. Contrary to previous expectations, our results provide evidence for a role of plastid translation in RNA editing.

Defective measles virus in human subacute sclerosing panencephalitis brain

Evidence is presented showing that the brain cells of patients with subacute sclerosing panencephalitis (SSPE) contain mutant measles (MV) genomes having the characteristics of 5' copy-back defective interfering (DI) RNAs. Using a polymerase chain reaction-based amplification specific for copy-back DIs, abundant, discrete cDNAs representing different-sized MV defective RNA species were generated from each SSPE brain. The defective genomes were cloned in two portions. The most common of these defective species were sequenced, confirming their MV genome origin and 5' copy-back nature. We deduced that the minimum DI stem length of these species was 95 nucleotides, further delimiting the prerequisite 5' regulatory region sequences specifying MV genomic replication/encapsidation functions. This calculation assumes a precise copy-back mechanism and complete complementarity of the panhandle structure. Since the SSPE-derived viral genome encodes dysfunctional viral envelope proteins, we hypothesize that SSPE brains may lack the high degree of selective pressure encountered in tissue culture MV infections. This allows for the coexistence of numerous replication-competent defective particles in each SSPE brain. A role for viral defective particles as modulators of this persistent measles virus infection of humans is proposed.

Changing practice patterns in refractive surgery: results of a survey of the American Society of Cataract and Refractive Surgery

A questionnaire on refractive surgical practice was sent to the entire membership of the American Society of Cataract and Refractive Surgery in 1992. One thousand eight hundred and forty-one (1,841) of the 4,950 members returned the survey for a response rate of 37.2%. The questionnaire was designed to be self-administered and elicited information on types of refractive procedures performed in the survey year and the preceding year, as well as the intent to perform refractive procedures in the future. Surgeons who perform radial keratotomy (RK) increased from 22% in 1991 to 30% in 1992; 45% expected to perform RK in 1993-1994. The following categories of information were requested: characteristics of RK patients, techniques used by the surgeon, characteristics of the surgeon's overall practice, type of RK training, surgical outcome, and prevalence of complications. The results of this survey indicate that the use of RK and astigmatic keratotomy (AK), as well as other refractive procedures, is steadily increasing. Radial keratotomy was mainly performed on patients 20 to 49 years of age who had low to moderate myopia. The majority of surgeons used four to eight radials, centrally directed incisions, and single depth settings. Three quarters of the surveyed RK surgeons used the Casebeer nomogram. The survey results indicated that 42% of surgeons performing photorefractive keratectomy (PRK) did not perform RK or other refractive procedures, suggesting that growth in the practice of PRK following FDA approval may come from both current RK surgeons and novice refractive surgeons.

Effects of reduced dietary magnesium on platelet production and function in hamsters

The increased vulnerability of animals fed a magnesium (Mg)-deficient (MD) diet to ischemia-induced myocardial necrosis has been attributed to changes in myocardial electrolyte metabolism. However, a variety of hematologic changes have also been reported in MD and some of these, such as an increase in platelet aggregability, may contribute to the increased myocardial vulnerability. In the present study, we quantified the effect of MD on platelet and megakaryocyte abundance as well as on platelet aggregability with and without an administered calcium channel blocker (nifedipine). Hamsters were fed either a "minimal Mg" diet, in which the level of Mg was kept just high enough to prevent seizures, or a "preset Mg" diet containing precisely known amounts of Mg. Animals fed the minimum Mg diet showed an initial increase in the platelet count, which returned to control range when the dietary Mg was increased to 9 mmoles/kg. Animals on the preset Mg diet showed an increased platelet count if the Mg level was 10 mmoles/kg or less. In addition to the increase in number, platelets from MD animals were less responsive to the aggregation-inhibiting effect of nifedipine than were platelets from control animals, although MD itself did not result in an increased aggregability under the conditions used here. Animals with an increase in circulating platelets showed decreased megakaryocyte abundance in the femoral marrow, but megakaryocytes that were present were larger than those in control animals. These results indicate a profound effect of dietary Mg deficiency on platelet biology. The observed changes could contribute to the increase in myocardial vulnerability to injury found in MD animals.

Detection of neuron specific enolase concentrations in cerebrospinal fluid from patients with neurological disorders by means of a sensitive enzyme immunoassay

An enzyme linked immunosorbent assay (ELISA) for the detection of neuron specific enolase (NSE) in cerebrospinal fluid (CSF) was developed. The sensitivity of the ELISA was less than 1 microgram/ml. This sensitivity is comparable with radioimmunoassays which have the disadvantage that radiolabelled products are used. The developed assay was used to measure cerebrospinal fluid neuron specific enolase (CSF-NSE) levels in 1178 patients with neurological disorders to establish its potential usefulness and clinical application. CSF-NSE levels in this group of patients were independent of sex and no correlation with age was found. CSF-NSE was significantly increased in Creutzfeldt-Jacob disease, meningeal hemorrhage, thrombosis, Guillain-Barré syndrome and in schizophrenia.

A serum protein involved in aging?

Aging of the brain is characterized, in part, by the appearance of protein anomalies. The proteins deposited within the nervous system structures are hardly soluble. This physiological phenomenon turns out to be pathological, quantitatively at least, and perhaps even qualitatively, in dementia of the Alzheimer's type (DAT). One might wonder whether the brain protein anomalies are related to a general process and, thus, could generate anomalies of the serum proteins. Therefore, we examined, with two-dimensional electrophoresis (2DE), 120 serum samples collected from different neurological patients and 24 serum samples from a control group, and we reached the following conclusion: a protein spot, normally not found and named 10M, corresponding to a molecular weight of 30 kDa with an isoelectric point of +/- 8, is seen in 31% of the patients affected with a neurological disease and in 90% of patients affected with DAT. The frequency of the appearance of this spot, seen after 2DE, increases with age. We wonder whether this protein is playing a role in the formation of the neuropathological lesions observed in DAT.

Blood and cerebrospinal fluid anomalies in brain ageing and Alzheimer's disease

The glial fibrillary acidic protein (GFAP), myelin basic protein (MBP), S100 protein (S100), gamma gamma-enolase and neurofilament proteins were determined in the CSF of neurological patients. In Alzheimer's disease (AD), the GFAP values were very often increased but this was not specific to this disease. In 2 cases of familial AD, increases in neurofilament protein were detected. The determination of autoantibodies against neurofilament proteins in blood showed rather low values in AD, although they were higher than in subacute sclerosing panencephalitis (SSPE) and Chagas' disease. Increases were observed in diseases not related to AD such as vascular disorders and Parkinson's disease.

Anti-neurofilament antibodies in blood of patients with neurological diseases

A method has been developed to determine quantitatively the level of the anti-neurofilament antibodies in the blood of patients affected with different neurological diseases. In 7 out of the 52 patients, taken as controls and in 33 out of the 208 patients affected with neurological diseases, the antibody levels were increased. The increases were greater in 43 patients with Parkinson dementia and amyotrophic lateral sclerosis who originated from Guam. On the other hand, the levels were very low in 10 patients affected with subacute sclerosing panencephalitis and in 11 cases with Chagas' disease. In 24 cases with dementia of Alzheimer type, the levels were normal.

A serum protein affecting the regulation of the immune system

A thermostable alpha 2 globulin inhibiting the immunoglobulin/anti-immunoglobulin reaction was demonstrated working with subacute sclerosing panencephalitis (SSPE) and control serum IgG. This protein was isolated from SSPE and normal human blood, it inhibits the immunoglobulin/anti-immunoglobulin reaction but no other antigen/antibody reactions when applying different immunochemical methods such as nitrocellulose immunofixation, 2 site immunoradiometric assay, solid phase radioimmunoassay in coated cups. This was demonstrated, working on the one hand with measles virus strain Edmonston or SSPE virus strain D.R. and SSPE serum and on the other hand with IgG from SSPE and control serum. This alpha 2 globulin, an inhibiting protein, appears to be related to "normal immunosuppressive protein".

Blood-brain barrier in chronic relapsing experimental allergic encephalomyelitis: a correlative study between cerebrospinal fluid protein concentrations and tracer leakage in the central nervous system

Blood-brain barrier (BBB) permeability in chronic relapsing experimental allergic encephalomyelitis was studied morphologically in tracer studies with horseradish peroxidase (HRP) as well as by quantitative determination of HRP, albumin, and IgG in serum and cerebrospinal fluid (CSF). BBB damage was found to be localized in demyelinating plaques and in blood vessels with vasculitis. Actively demyelinating lesions showed massive increase in BBB permeability, whereas in inactive or remyelinated lesions BBB damage was either minimal or absent. Determination of serum proteins in the CSF of animals with severe disease and a high incidence of actively demyelinating lesions showed evidence of BBB damage (reduction of Q-albumin) and an IgG-index in the normal range. In animals with only inactive lesions the Q-albumin was normal, the IgG index, however, was elevated. This finding indicates intrathecal IgG synthesis. A correlation between morphologically visualized tracer leakage in the central nervous system (CNS) with serum protein concentrations in the CSF revealed that elevated CSF albumin is a reliable indicator for BBB damage in lesions, located near the inner or outer surface of the brain and spinal cord. However, singular focal lesions with BBB damage located in the depth of the CNS parenchyma may not be accompanied by CSF protein alterations. The invariable presence of BBB damage in active inflammatory demyelinating lesions and its absence in inactive plaques or in the unaffected nervous tissue may be important in therapy, not only in experimental allergic encephalomyelitis but also in multiple sclerosis (MS).

Hyperargininemia: the rat as a model for the human disease and the comparative response to enzyme replacement therapy with free arginase and arginase-loaded erythrocytes in vivo

Rat erythrocytes lack arginase as do the erythrocytes of human homozygote patients with hyperargininemia due to arginase deficiency. The rat has physiological liver arginase activity and plasma arginine and ornithine levels between the homozygotes and the heterozygotes with hyperargininemia. In rats, one injection of free arginase induces a transient exogenous arginase effect which is abolished after 24 hr. One injection of isoionic arginase-loaded erythrocytes provokes an exogenous arginase effect in physiological "hyperargininemic" rats and pathological "hyperargininemic"-made rats for at least 8 and 5 days respectively. The very transient response in vivo to exogenous free arginase can be considerably prolonged by entrapment of the arginase in isoionic prepared erythrocytes.

Antibodies-restricted heterogeneity in serum and cerebrospinal fluid of chronic relapsing experimental allergic encephalomyelitis

An animal model which might help to study multiple sclerosis has long been sought. With chronic relapsing experimental allergic encephalitis (EAE), the search seems to have brought hope and evidence of comparable pathology whether concerned with clinical or neuropathological results, but no study of the cerebrospinal fluid (CSF) electrophoretic pattern has been made so far. A new sensitive method enables to study the CSF proteins: unconcentrated CSF proteins after agar gel electrophoresis are stained with silver reagents. The silver technique allows to follow the evolution of the inflammatory reaction in chronic relapsing EAE as well as in the acute form of EAE. This technique provides an additional approach to the study of EAE and an argument in favor of chronic relapsing EAE in guinea pigs as a model for multiple sclerosis.

Glial cells identified by anti-alpha-albumin (anti-GFA) in human pineal gland

Alpha-albumin, a CNS specific protein, identical to GFA protein and specific glial cells, has been found in the human pineal gland using histoimmunological and quantitative methods. The significance of its presence in the pineal gland is discussed.

Subacute sclerosing panencephalitis antibodies against measles virus polypeptides

Antibodies to measles virus proteins in SSPE, MS and control human sera were compared using measles virus strain Edmonston, productive SSPE strain Mantooth and non-productive SSPE strain DR. The viral antigens were subjected to transfer electrophoresis, incubated with sera and localized after a second incubation with peroxidase labeled immunoglobulins. High levels of antibodies to all measles viral proteins are present in SSPE sera and CSF and to a lesser degree in MS and control sera although the non-productive SSPE strains lack one viral protein (M protein) present in wild type measles virus strains and the productive SSPE strains.

Serological identification of viral antigens after electrophoretic transfer

The method described permits detection of specific antibodies to antigenic material, the protein components of which can first be separated by electrophoresis and then transferred to a supporting medium where their reactivity with antibody may be demonstrated using peroxidase-labelled anti-Ig. Results are described for measles virus and measles-like virus isolated from subacute sclerosing panencephalitis (SSPE) brain. Dilutions, incubation time and conditions, detection with peroxidase-labelled immunoglobulins and selection of substrate are described and discussed.

Immunochemical determination and immunocytological localization of brain-specific protein alpha-albumin (GFA) in isolated astrocytes

Astrocyte- and neuron-enriched fractions were isolated by preparative centrifugatin from rat brain and human brain, obtained at autopsy. The brain-specific protein alpha-albumin (GFA) was studied in these fractions by quantitative immunoradiochemical and by immunocytological methods. It is concluded that morphologically intact astrocytes can be isolated not only from rat, but also from human brain. In the rat, alpha-albumin (GFA) is only found in the astrocyte-enriched fractions; this shows that detemination of alpha-albumin (GFA) is useful for the evaluation of cell separation methods for the brain. From the astrocyte-enriched fractions, four times more alpha-albumin (GFA) can be extracted when detergent (0.1% SDS) is used, than when an aqueous extract is made. About +/- 0.15 X 10(-6) particles were extracted in 1 ml of either PBS or SDS/PBS. This suggests that alpha-albumin (GFA) exists in at least two forms, one hydrosoluble, and one detergent soluble, possibly structurally bound, form.

Diagnostic value of brief microzone electrophoresis of unconcentrated CSF and agar gel electrophoresis of concentrated and unconcentrated CSF

This paper reports a comparison between brief microzone electrophoresis and agar gel electrophoresis of CSF proteins; 41 different CSFs were examined simultaneously by all three methods. Fractionation of gamma-globulins was found by brief microzone electrophoresis in 53.7% of unconcentrated CSF. This fractionation was found in 63.4% of unconcentrated CSF after agar gel electrophoresis, in 48.8% of concentrated CSF. Serum-like pherogram and the rapid alpha-globulin type were found equally often.

Comparison of the brain specific protein alpha-albumin and GFA (glial fibrillary acidic protein)

In this study, the brain specific proteins alpha-albumin and glial fibrillary acidic protein (GFA) are compared by several biochemical and immunological methods. It is concluded that alpha-albumin and GFA are immunologically identical and biochemically narrowly related. The existence of two forms of this protein, a water soluble and a water insoluble, under physiological conditions is discussed by comparing the results of quantitative determinations and histoimmunological localizations.

Cerebrospinal fluid proteins electrophoresis without prior concentration

There is a need for new methods to study CSF proteins. Kerenyi et al., 1973 and Verheecke, 1975 have already used this method and discussed its advantages. The electrophoresis is carried out according to the method of Wieme with as supporting medium agar. The volume applied varies between 5 to 15 microliters according to the total protein content and the width of the slit. Care must be taken to work at all times with bidistilled water and pro analysis reagents. After drying, the electrophoretic plates are reduced in a 10% solution of thiodiglycol, dried again, then immersed in 2% potassium hexacyanoferrate, washed thoroughly, then revealed with a silver nitrate solution (Kerenyi et al., 1973; Verheecke P., 1975) and left in 1% acetic acid. This technique is of major value as: 1. It avoids artefacts due to concentration and loss of proteins; 2. It works with very small amounts of fluid; 3. Where the CSF is silent for antibodies restricted heterogeneity using the classical methods, it reveals marked IgG fractionation.

Cerebrospinal fluid protein electrophoresis without prior concentration

There is a need for new methods to study CSF proteins. Kerenyi et al., 1973 and Verheecke, 1975 have already used this method and discussed its advantages. The electrophoresis is carried out according to the method of Wieme with as supporting medium agar. The volume applied varies between 5 to 15 microliter according to the total protein content and the width of the slit. Care must be taken to work at all times with bidistilled water and pro analysis reagents. After drying, the electrophoretic plates are reduced in a 10% solution of thiodiglycol, dried again, then immersed in 2% potassium hexacyanoferrate, washed thoroughly, then revealed with a silver nitrate solution (Kerenyi et al., 1973; Verheecke P., 1975) and left in 1% acetic acid. This technique is of major value as: 1. It avoids artefacts due to concentration and loss of proteins; 2. It works with very small amounts of fluid; 3. Where the CSF is silent for antibodies restricted heterogeneity using the classical methods, it reveals marked IgG Fractionation.

A two-site immunoradiometric assay for the determination of alpha-albumin

A two-site immunoradiometric assay for a brain specific protein (alpha-albumin or glial fibrillary acidic protein) is described which may be applied to other proteins. The assay variables studied are immunoadsorbent dilution, temperature, incubation times, reactivity of the labelled antibodies and effect of the washing. Each of these factors is optimalised, resulting in a sensitive, specific, reliable assay. The working range is 5--5000 ng/ml, the within-assay variance is 5%. No high dose hook effect is seen in this range. The method is applied for the measurement of alpha-albumin present in cerebrospinal fluid, nervous tissue extracts and cell cultures.

alpha-Albumin (glial fibrillary acidic protein) in normal and pathological human brain and cerebrospinal fluid

alpha-Albumin, a specific brain protein observed after agar gel electrophoresis and shown to be identical to the later described GFA, has been determined in normal and pathological human central nervous system and cerebrospinal fluid. The outcome of this study underlines the value of the detection of specific proteins of the brain in biological fluids.

A heat stable serum inhibitor of an antigen antibody reaction of subacute sclerosing panencephalitis

A factor which inhibits the antigen antibody reaction was isolated from the sera of patients affected with subacute sclerosing panencephalitis (SSPE), multiple sclerosis (MS) and also of control subjects. This factor inhibits the immune reaction between SSPE serum IgGs and measles virus. This inhibiting factor was detected in the alpha globulin region after agar gel electrophoresis, and is heat stable at 100 degrees C for ten minutes.

Imbalance of k/lambda ratios associated with high measles antibody titers in fractionated serum immunoglobulins of patients affected with subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis (SSPE) is a neurological disease which is characterized not only by the appearance of oligoclonal immunoglobulins in cerebrospinal fluid (CSF) and serum but also by high measles antibody titers and disturbed k/lambda ratios, as well in serum as in CSF. These findings lead to the hypothesis that specific immunoglobulins are produced by hyperimmunisation against measles and/or measles-like virus. Therefore the serum IgG from subacute sclerosing panencephalitis patients were fractionated by column isoelectric focusing and the k/lambda light chain ratio and the measles antibody titer of each fration were determined. The highest k/lambda ratios and the highest measles antibody titers were found mainly in two fractions at a pH ranging from 8.94-8.51 for the first and 8.88-8.24 for the second.

Use of enzyme-loaded erythrocytes in in-vitro correction of arginase-deficient erythrocytes in familial hyperargininemia

The capacity of arginase-deficient erythrocytes of patients with familial hyperargininemia to produce urea and to catabolize arginine can be increased in vitro by introducing human liver arginase into their erythrocytes. The results of this study on a specific human model show that it is possible to change the metabolic function of a genetically defective erythrocyte by incorporating exogenous human enzyme. The in vivo application of enzyme-loaded erythrocytes for enzyme replacement therapy of inborn metabolic errors in humans must await in vivo studies on animal models.

Use of enzyme-loaded erythrocytes in in-vitro correction of arginase-deficient erythrocytes in familial hyperargininemia

The capacity of arginase-deficient erythrocytes of patients with familial hyperargininemia to produce urea and to catabolize arginine can be increased in vitro by introducing human liver arginase into their erythrocytes. The results of this study on a specific human model show that it is possible to change the metabolic function of a genetically defective erythrocyte by incorporating exogenous human enzyme. The in vivo application of enzyme-loaded erythrocytes for enzyme replacement therapy of inborn metabolic errors in humans must await in vivo studies on animal models.

Structural homogeneity of human subacute sclerosing panencephalitis antibodies

Three homogeneous immunoglobulin fractions were isolated from the serum of a patient with subacute sclerosing panencephalitis (SSPE). All three fractions reacted in immunodiffusion with measles and SSPE virus preparations. The amino-terminal sequence of the light and heavy chains of one of the antibody fractions was determined by automated Edman degradation. A single amino acid residue was obtained at every step, confirming the homogeneity of this human antibody.

The chemical composition of idiopathic nonarteriosclerotic cerebral calcifications

Calculi from a case of cerebral idiopathic nonarteriosclerotic calcification (Fahr's disease) were examined. The stone consists of hydroxyapatite and possesses a typical structure: the calcification process seems to be initiated by the formation of small round bodies that are cemented to each other to form the final stone. Calcified vessels are also present, but seem to be a secondary effect. From a comparison with other calcifications, it is concluded that no pathologic significance should be attached to the relatively high levels of trace metals such as zinc, iron, copper, magnesium, lead, and others, with the possible exception of manganese. The organic matrix of the stone contains large quantities of protein. On hydrolysis of this fraction, an important unidentified ninhydrin-positive peak was found. No mucopolysaccharides were found.

Isolation and characterization of IgG globulins in subacute sclerosing panencephalitis

Patients affected with subacute sclerosing panencephalitis were found to show high measles antibody activity; γ-globulin M-components were detected in the serum, cerebrospinal fluid and brain tissue. The relative antibody activity was different in the different IgGs separated by gel filtration. The γ-globulins were separated into several components by isoelectric focussing on a sucrose gradient and each showed different degrees of measles antibody activity. Better separation was achieved by isoelectric focusing than by gel chromatography.