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Biomedical subjects

D L Reynolds

Publications and source records attributed to D L Reynolds.

At least 55 records · Page 3Linked to original sources
PubMedDate not supplied

Characterization of the stunting syndrome agent: physicochemical properties.

Stunting syndrome is an enteric disease of turkeys causing diarrhea, reduced weight gain, poor feed efficiency, and maldigestion. The etiologic agent is a newly identified, but unclassified, virus termed the stunting syndrome agent (SSA). The SSA is a pleomorphic, enveloped virus ranging from 60 to 95 nm in diameter. The objectives of this study were to characterize the physicochemical properties of SSA. SSA hemagglutinated rat erythrocytes at 4 C and room temperature. Treatment of SSA with ether resulted in loss of infectivity. SSA was resistant to pH changes between pH 3.0 and pH 9.0 at 37 C for 1 hr. The virus was inactivated at pH > or = 10. SSA was resistant to treatment with trypsin, chymotrypsin, pancreatin, phospholipase C, and sodium deoxycholate. Treatment of SSA with trypsin, chymotrypsin, and pancreatin resulted in enhanced viral infectivity. The viral genome extracted from purified SSA was sensitive to RNAse treatment. Using oligo d(T)16-18 and random hexamers as primers, the SSA genome was amplified using the reverse transcription-polymerase chain reaction conditions but was not amplified using polymerase chain reaction conditions. The enrichment of viral genome was achieved following poly-A+ selection. These studies provide evidence that the SSA is a positive-sense, single-stranded RNA virus having many characteristics (stability at acidic pH, resistant to proteolytic enzymes and bile salt) consistent with other enveloped enteric viruses.

Animals↗
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The sensitivity and specificity of a reverse transcription-polymerase chain reaction assay for the avian pneumovirus (Colorado strain).

A reverse transcription-polymerase chain reaction (RT-PCR) assay for the detection of avian pneumovirus (APV), Colorado strain (US/CO), was evaluated for sensitivity and specificity. The single-tube RT-PCR assay utilized primers developed from the matrix (M) gene sequence of the US/CO APV. The RT-PCR amplified the US/CO APV but did not amplify other pneumoviruses, including the avian pneumoviruses subgroups A and B. The RT-PCR was capable of detecting between 10(0.25) mean tissue culture infective dose (TCID50) and 10(-0.44) TCID50 of the US/CO APV. These results have demonstrated that the single-tube RT-PCR assay is a specific and sensitive assay for the detection of US/CO APV.

Animals↗
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A multiplex reverse transcription-polymerase chain reaction assay for Newcastle disease virus and avian pneumovirus (Colorado strain).

Newcastle disease virus (NDV) and avian pneumovirus (APV) cause Newcastle disease and rhinotracheitis respectively, in turkeys. Both of these viruses infect the respiratory system. A one-tube, multiplex, reverse transcription-polymerase chain reaction (RT-PCR) assay for the detection of both NDV and Colorado strain of APV (APV-Col) was developed and evaluated. The primers, specific for each virus, were designed from the matrix protein gene of APV-Col and the fusion protein gene of NDV to amplify products of 631 and 309 nucleotides, respectively. The multiplex RT-PCR assay, for detecting both viruses simultaneously, was compared with the single-virus RT-PCR assays for its sensitivity and specificity. The specific primers amplified products of predicted size from each virus in the multiplex as well as the single-virus RT-PCR assays. The multiplex RT-PCR assay was determined to be equivalent to the single-virus RT-PCR assays for detecting both NDV and APV-Col. This multiplex RT-PCR assay proved to be a sensitive method for the simultaneous and rapid detection of NDV and APV-Col. This assay has the potential for clinical diagnostic applications.

Animals↗
PubMedDate not supplied

Detection of avian pneumovirus in tissues and swab specimens from infected turkeys.

Conventional nested and TaqMan reverse transcription-polymerase chain reaction (RT-PCR) assays for the detection of avian pneumovirus (APV) were evaluated and compared with virus isolation (VI) for sensitivity and specificity. Respiratory tissues and tracheal swabs were collected from experimentally inoculated turkeys between 1 and 21 days postinoculation (DPI) and tested by all detection methods. APV was detected by both RT-PCR procedures as early as 1 DPI and as late as 17 DPI, whereas virus was isolated only between 3 and 7 DPI. Pooled tracheal swab supernatant and dry swabs were excellent specimens for the detection of APV between 3 and 8 DPI. Turbinate and sinus specimens were the most productive samples over the entire collection period. Both RT-PCR assays were rapid and more sensitive than VI for the detection of APV in tissue and swab specimens from infected turkeys. RT-PCR allows for the rapid detection of APV from a variety of respiratory tissues as well as from dry swabs and tracheal swab supernatants. Antibody to APV was detected in 50% of the sampled APV-inoculated birds at 8 and 9 DPI by enzyme-linked immunosorbent assay (ELISA). Early seroconversion (8-10 DPI) allows antibody detection to be used as a screening tool for APV. Rapid and sensitive detection methods are needed for APV, a highly contagious disease affecting U.S. poultry.

Animals↗
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Measuring alcohol abuse in the community: consumption, binge-drinking, and alcohol-related consequences ("alcoholism").

This study reported and compared community health indicators for the measurement of alcohol abuse. Using data from the 1989 Hamilton-Wentworth Health Survey, similar rates were found for four differing definitions of alcohol abuse: 1) drinking everyday (5.7%, 95% confidence limit (CL) = 3.8-7.7%), 2) drinking at least 14 drinks in the past seven days (12.1%, 95% CL = 9.2-15.1%), 3) frequent binging on 10 drinks or more (9.4%, 95% CL = 6.9-11.8%), and 4) "alcoholism" as defined by the Michigan Alcoholism Screening Test (MAST) (7.4%, 95% CL = 5.1-9.7%). Binging on five drinks or more occurred frequently (37.0, 95% CL = 32.8-41.1%). All indicators of alcohol abuse from the survey were significantly higher for males as compared to females (p < 0.05), and demonstrated varying distributions by age. Estimates of drinking consumption based on the sale of alcoholic beverages in the community were also examined and found to estimate consumption levels nearly double that of the self-reported survey data. Relevance to public health planning and monitoring is discussed.

Adolescent↗
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Healthy communications: producing a health report (Infowatch) for monitoring and promoting health in local communities.

In order to bridge the gap between producers and users of community health data, we have developed a standardized format to provide a simple, comprehensive approach to the communication of epidemiologic data at the local level. Infowatch follows a series of format and style rules selected to enhance readability. The four-page format is divided into six sections: introduction and scope; "results" presented as charts, figures and text; policy implications (through consultation with community groups); methodological summary; references for self-study; and, invitation for reader feedback. An editorial committee comprising experts and representatives from local interest groups ensures that the data presented are relevant and of high quality. The content of each Infowatch issue varies depending on community priorities. Infowatch is distributed to 3,000 people, including representatives from health-related, academic, governmental and non-governmental agencies. Five areas assess qualitatively the impact of Infowatch: reader, media, policy, education, and solicited responses. Overall, response from all categories has been favourable with evidence of infiltration into policy.

Community Health Services↗
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Evaluation of the cell-mediated immune response of chickens vaccinated with Newcastle disease virus as determined by the under-agarose leukocyte-migration-inhibition technique.

The under-agarose leukocyte-migration-inhibition (LMI) assay for the evaluation of cell-mediated immunity (CMI) was developed for use in chickens. A significant CMI response was demonstrated in chickens vaccinated with Newcastle disease vaccine by using this assay. Results also indicated that the under-agarose LMI test was a reproducible and relatively easy assay to perform. Serologic antibody titers were determined to study the correlation between hemagglutination-inhibition (HI) titers and LMI levels using the HI microassay. The presence of the CMI response always correlated to the presence of the serologic immune response and vice versa. However, the quantitative level of the CMI response did not always correspond to the quantitative level of the serologic immune response. Going by results of this study, we were unable to predict humoral antibody level on the basis of a CMI response and vice versa.

Animals↗
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Reliability of cancer mortality statistics in Ontario: a comparison of incident and death diagnoses, 1979-1983.

We compared the underlying cause of cancer death listed on death certificates, to the registry diagnosis from the incident file in the Ontario Cancer Registry (OCR). For the 68,772 cancer deaths having both a registry diagnosis and a cancer cause of death, 79.3% agreed between the two sources at the third digit level of ICD-9; this rose to 85.8% when sites were aggregated into about 30-site groups (positive predictive value 85.8%, sensitivity 82.9%). The most common sites, accounting for greater than 80% of all cancer deaths, all had agreement rates above 80%. Sites of questionable reliability, comprising less than 10% of all cancer deaths, included liver and larynx, and most other ill-defined and unspecified sites. Recommendations to improve the quality of published cancer mortality statistics include combining colon and rectum, and the non-Hodgkin's lymphomas. Caution in the use and interpretation of statistics for cancers of the liver and larynx is suggested owing to poor reliability.

Cause of Death↗
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Long-segmented filamentous organisms observed in poults experimentally infected with stunting syndrome agent.

One-day-old turkeys were inoculated per os with material shown previously to induce stunting syndrome (SS). Weight gain and feed efficiency of inoculated poults from 1 to 13 days of age were impaired (P less than 0.01) compared with uninoculated poults. Examination of the jejunal mucosa by scanning and transmission electron microscopy showed the presence of long-segmented filamentous organisms (LSFOs) in poults that had been inoculated with SS. These organisms were not seen in jejuna of uninoculated poults. Further research is needed to characterize LSFOs and to determine their involvement, if any, in the adverse effects associated with SS.

Animals↗
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An avidin-biotin enhanced dot-immunobinding assay for the detection of Mycoplasma gallisepticum and M. synoviae serum antibodies in chickens.

A dot-immunobinding assay was enhanced by the incorporation of avidin and biotin reagents into the test system (DAB assay). This assay was used to detect serum antibodies to Mycoplasma gallisepticum (MG) and M. synoviae (MS) from chickens. Serum samples were tested by rapid serum plate (RSP), hemagglutination-inhibition (HI), and DAB assay methods. These results were compared. The DAB assay was at least 20 times more sensitive in detecting antibodies for MS and at least 75 times more sensitive in detecting antibodies for MG than the HI test. The DAB assay was as specific as the HI test. The DAB assay was also more sensitive and specific than the RSP test. Some cross-reactions occurred when low dilutions of high-titer sera were used in the DAB assay. Parameters for determining negative, suspicious, and positive samples were established. The DAB assay for MG and MS may have several applications, including use as a screening test and a confirmatory test.

Animals↗
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Use of an avidin-biotin enhanced dot-immunobinding assay to detect antibodies for avian mycoplasma in sera from Iowa market turkeys.

A dot-immunobinding assay, amplified with avidin and biotin (DAB assay), was used to detect serum antibodies to Mycoplasma iowae in immunized turkeys. The DAB assay was used to test serum samples from 122 commercial market turkey flocks obtained from four Iowa processing plants. The samples were pooled and tested for the presence of antibodies to four species of Mycoplasma spp. considered to be important pathogens for turkeys: M. gallisepticum (MG), M. iowae (MI), M. meleagridis (MM), and M. synoviae (MS). The occurrence of antibodies against these mycoplasmas, as determined by the DAB assay, were 5.7% for MG, 18.0% for MI, 77.9% for MM, and 9.8% for MS.

Animals↗
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Isolation and serial propagation of turkey rotaviruses in a fetal rhesus monkey kidney (MA104) cell line.

Turkey rotaviruses from the intestinal contents of poults were isolated and serially propagated in MA104 cell monolayers by a simple procedure. The initial virus isolation was done by low-speed centrifugation of the inoculum onto the monolayers, and subsequent passages were accomplished in roller-tube monolayers using trypsin-treated virus suspensions. Each of the turkey rotavirus isolates possessed the morphologic, antigenic, and genomic attributes characteristic of turkey group A rotaviruses. Attempts to isolate and serially propagate turkey rotavirus-like viruses in MA104 cell monolayers by this procedure were unsuccessful. Turkey reoviruses also did not serially propagate in MA104 cell monolayers by this procedure.

Animals↗
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A survey of enteric viruses of turkey poults.

Intestinal samples from 91 turkey flocks between 1 day and 5 weeks of age were examined for enteric viruses using electron microscopy and electropherotyping. These flocks originated from eight operations in six states. Individual flocks were sampled only once. At the time of sampling, 31 flocks were considered normal/healthy and 60 were considered to have enteric disease. The most frequently identified viruses from diseased flocks were astroviruses (78%) and rotavirus-like viruses (RVLVs) (67%). Far less frequent were rotaviruses (22%), atypical rotaviruses (12%), enteroviruses (5%), and reoviruses (2%). Only 10% of the samples from diseased flocks were negative, but 48% of the samples from normal/healthy flocks were negative. Astroviruses and RVLVs were far less frequent in normal/healthy flocks than in diseased flocks, but rotaviruses were identified slightly more often. No viruses were detected from flocks sampled within the first few days of life. Astrovirus infections seemed to occur at an earlier age than other virus infections. Seldom was only one type of virus identified. Astrovirus + RVLV was the most frequently identified combination in diseased flocks.

Animals↗
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Enteric viral infections of turkey poults: incidence of infection.

Four flocks from one commercial market-turkey operation in Ohio were monitored for the presence of enteric viruses. Each flock was sampled at intervals from placement until at least 7 weeks of age; sampling was more frequent in the first 4 weeks of life. The earliest infections detected were astrovirus infections or combination infections of astrovirus and rotavirus-like virus (RVLV) or astrovirus and rotavirus. During the first 4 weeks of life, astrovirus was the most frequently detected virus, followed by RVLV, then rotavirus. These viruses were seldom detected beyond 4 weeks of age. In three of the four flocks, no viruses were detected in samples collected before 6 days of age; in one flock, however, rotavirus and astrovirus were identified from samples collected at 3 days of age. Experimental infection of specific-pathogen-free poults with astrovirus and RVLV produced enteric diseases in poults and demonstrated that astrovirus was shed into the intestinal tract before RVLV. Poults experimentally infected with astrovirus and RVLV displayed clinical signs of diarrhea and upon necropsy exhibited dilated ceca, frothy gaseous intestinal contents, and loss of intestinal tone.

Adenoviridae Infections↗
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Demonstration of rotavirus and rotavirus-like virus in the intestinal contents of diarrheic pheasant chicks.

Intestinal content samples from four flocks of pheasant chicks experiencing diarrhea and increased mortality were evaluated using immune electron microscopy and genome electropherotyping techniques. Enteric viruses serologically and electropherotypically indistinguishable from turkey rotaviruses and turkey rotavirus-like viruses (RVLVs) were detected. Rotavirus-only infections, RVLV-only infections, and simultaneous rotavirus and RVLV infections were demonstrated in these flocks.

Animals↗
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Analytical methods for measuring uric acid in biological samples and food products.

During the last 7 decades, uric acid methodology has kept pace with the introduction of state-of-the-art technology (e.g., spectroscopy, electrochemistry, chromatography) or the discovery of unique chemical processes (e.g., redox, enzymatic). We envision this practice will continue in the future. There never will be a single analytical method applicable for biofluids or foodstuffs. Therefore, it is imperative that the analyst not only understand the advantages and disadvantages of a procedure, but also thoroughly understand its underlying chemical and technological principles. Since many procedures available for analysis of biofluids and foodstuffs rely on identical chemical or technological principles, this report shall review both sample types and the available spectroscopic, electroanalytical, and chromatographic methods.

Animals↗
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Astrovirus: a cause of an enteric disease in turkey poults.

Virus particles of 30 nm diameter and star-shaped morphology were detected in intestinal contents of turkey poults and were identified as astroviruses. Seventy-six intestinal samples from 65 commercial turkey flocks between 6 and 35 days of age were evaluated for the presence of astroviruses by immune electron microscopy. Astroviruses were frequently detected in intestinal samples from poults that had enteritis and diarrhea of undetermined etiology. Astroviruses were geographically widespread and were present in poults from all six operations evaluated. Astroviruses were inoculated into specific-pathogen-free poults. Changes observed in the gastrointestinal tract were: dilatated ceca containing yellowish frothy contents, gaseous fluid in the intestinal tract, and loss of tone of the intestinal tract (gut thinness). Poults experimentally inoculated with astrovirus gained significantly less body weight and absorbed significantly less D-xylose than uninoculated controls.

Animals↗