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PubMed1992

Microbiologic assessment of tissue biopsy samples from ileal pouch patients.

Tissue biopsy samples from patients with and without ileal pouches were examined by electron microscopic and microbiologic culture techniques to determine the numbers and types of microorganisms closely associated with or within the tissue biopsy samples. The disease status of each patient was determined by endoscopic and histopathologic methods. Of the 78 biopsy samples included in this study, 64 (82%) yielded obligately anaerobic and/or facultative bacteria when they were cultured. Fourteen of the 78 samples (17.9%) were negative by culture. Of the positive samples, 54 contained facultatively anaerobic bacterial species and 50 yielded obligately anaerobic species. The total counts for facultatively anaerobic bacteria for samples from patients with pouchitis were significantly greater than for samples from patients in control groups. In addition, the number of samples from patients with normal pouches that did not contain obligate anaerobes was significantly less than that from patients with pouchitis; 4 of 23 and 6 of 12 samples, respectively (P less than 0.043). For samples in which organisms were detected, there was agreement with electron microscopic detection of bacteria in 23 of 27 samples, for an overall sensitivity of electron microscopy compared with that of culture of 85%. The qualitative studies resulted in the characterization of 273 isolates comprising 77 different phenotypes. The specificity of these findings in patients with ileal pouchitis is discussed.

Bacteria, Anaerobic↗
PubMed2006

Comparison between the Hybrid Capture II Test and an SPF1/GP6+ PCR-based assay for detection of human papillomavirus DNA in cervical swab samples.

We compared the efficacy of human papillomavirus (HPV) DNA detection between a PCR-based genechip (Easychip HPV Blot [hereafter referred to as HPV Blot]; King Car, Taiwan) method and Hybrid Capture II (HCII; Digene, Gaithersburg, MD) in women with previous normal (n = 146) or abnormal (> or =atypical squamous cells of undetermined significance [ASCUS] [n = 208]) cytology. A total of 354 cervical swab samples were collected for HPV DNA assay by both HCII and SPF1/GP6+ PCR followed by HPV Blot tests. Colposcopy-directed biopsy was performed if clinically indicated. Of the 354 samples, HPV-positive rates by these two methods (HCII and HPV Blot) were 12.6% and 18.2% in 143 normal samples, 36.2% and 45.7% in 105 ASCUS samples, 57.4% and 57.4% in 94 low-grade squamous intraepithelial lesion samples, and 83.3% and 75.0% in 12 high-grade squamous intraepithelial lesion samples, respectively. The concordance of HPV Blot and HCII was 80.8% (286/354), and the agreement between the methods (kappa value, 0.68) was substantial. Discrepancies were further investigated by at least one of the following three methods: direct sequencing, type-specific PCR, and HPV Blot genotyping of cervical biopsy tissue. In the 15 HCII-positive samples, HPV Blot detected only non-HCII HPV genotypes; results of further verification methods were consistent with the latter test in the 15 samples. Of the 20 samples with HCII-negative and HPV Blot-positive results, 18 were found to contain the 13 HCII high-risk genotypes by verification methods. In only 16.7% (3/18) of the HCII-positive but HPV Blot-negative samples, further studies detected the 13 HCII genotypes. We conclude that HPV Blot seemed comparable to HCII for detection of HPV DNA in cervical swab samples.

Base Sequence↗
PubMed1992

Evaluation of an enzyme immunoassay kit for detecting cryptosporidium in faeces and environmental samples.

AIMS: To evaluate a commercially available enzyme immunoassay based on a monoclonal antibody to a genus specific Cryptosporidium (IDEIA Cryptosporidium; Dako) antigen for detecting Cryptosporidium oocysts in faecal and environmental samples. METHODS: 435 human faecal samples and post-filtration deposits from 10 reservoir samples, and from six tap water samples seeded with Cryptosporidium oocysts, were examined by EIA according to the manufacturer's instructions, and by microscopic examination of phenolauramine stained smears. Samples giving discrepant results were examined by specific immunofluorescence, before and after concentration of oocysts. RESULTS: Sixteen (3.6%) faecal samples were positive by both microscopy and EIA; five (1.1%) were positive by microscopy of auramine-phenol stained smears (but were not confirmed by specific immunofluorescence) and negative by EIA; one (0.2%) was positive by EIA alone, but confirmed by specific immunofluorescence; and 362 (83.2%) were negative by both microscopy and EIA. Compared with immunofluorescence positive faecal samples, the sensitivity of conventional microscopy and EIA were 94% and 100%, and specificity 76.4% and 100%, respectively. Fifty one (11.7%) were not examined by microscopy due to detection of other pathogens in a previous sample from that patient, but were found to be negative by EIA. Ten reservoir water samples (not suspected of being linked to cases of cryptosporidiosis) were negative by both microscopy and EIA. Of six samples of tap water seeded with varying concentrations of Cryptosporidium oocysts, two (10(2) and 10(3) oocysts/l) were positive by both microscopy and EIA, two (10 and 1/l) by EIA alone, and two (0.1/l and unseeded water) were negative by both microscopy and EIA. CONCLUSIONS: The kit is simple and rapid to use and offers a less subjective method than microscopy for detecting Cryptosporidium in faecal samples submitted to a busy diagnostic laboratory.

Animals↗
PubMed1998

Quality assessment of protected specimen brush samples by microscopic cell count.

Protected specimen brushing (PSB), combined with quantitative culture, is now recognized as one of the reference methods for diagnosis of nosocomial pneumonia. However, no criteria exist with which to assess the quality of the PSB sample. We studied numbers of inflammatory cells and bronchial cells per microscopic field (magnification: x500, objective x50) in cytospin preparations of PSB samples. Results of cell count and quantitative culture in a first study period were compared with those in a second study period, following adaptation of the PSB technique and collection of samples from more peripheral sites. The cellular content of samples from patients and controls was investigated. We examined 86 samples from patients with suspected nosocomial pneumonia and 15 samples from uninfected controls. The number of samples with a high cellular content was considerably greater in the second study period. No positive cultures were obtained from samples containing < 10 cells per field. The numbers of cells in samples from uninfected controls were comparable to the numbers in samples from patients. Our results indicate that absence of cells probably represents inadequate sampling. Negative PSB cultures with cytospin preparations containing < 10 cells per microscopic field should therefore be considered with caution, and resampling considered.

Bacteria↗
PubMed1998

Preparation of urine samples for trace metal determination: a study with aluminium analysis by inductively coupled plasma optical emission spectrometry.

Urinary analysis of trace metals forms a significant role in clinical chemistry, but the optimal preparation and analysis of urine samples has not been investigated. Human urine is generally supersaturated with dissolved solids. Therefore, samples often precipitate following collection. X-ray microanalysis showed that this precipitate was predominantly rich in calcium and phosphorus but could include some trace metals from urine, potentially lowering their concentrations in solution. Hence, the precipitate must be fully redissolved for accurate analysis of trace metals in urine. Methods are emphasized for the best collection and preparation of urine samples for subsequent trace metal analysis; in this work inductively coupled plasma optical emission spectrometry (ICPOES) was used for the analysis of aluminium. For optimal accuracy, peak profiles were collected over 396.147 nm-396.157 nm. Urinary aluminium levels were investigated from 10 healthy volunteers and concentrations were obtained using either aqueous, pooled or individual urine-based standard curves. Since urine has a highly variable matrix, individual sample-based standards, which are unique to that particular sample, gave the most accurate results. However, where sample size is small or sample numbers are unfeasibly large, pooled sample-based standards give good approximations to within 15% and, with appropriate validation, other elements as internal standards could also be used for approximations. Aqueous standards should be avoided. Spike-recovery experiments confirmed these data since individual sample based standards showed optimal recovery [99.3 (4.4)%], while pooled sample-based standards were a close proxy [101.6 (9.2)%] but aqueous standards were inappropriate [137.4 (12.8)%]. Postprandial urinary aluminium levels of the 10 volunteers were [7.2 (3.7)micrograms/L] after analysis using individual sample-based standard curves.

Aluminum↗
PubMed2005

Two spent dialysate samples are sufficient for hemodialysis efficacy assessment.

INTRODUCTION: The measure of dialysis efficacy is expressed as Kt/V value (calculated from predialysis and postdialysis blood urea concentration). The aim of this study was to assess the possibility of direct calculation of Kt/V value from two spent dialysate samples by using the regular blood-based Kt/V calculation formula with dialysate samples used as surrogates for blood samples, and to detect the most appropriate couple of dialysate samples for Kt/V estimation. PATIENTS AND METHODS: Fifty-two single hemodialysis treatments in 34 anuric patients on chronic bicarbonate low-flux hemodialysis were observed. Kt/V values according to Daugirdas formula from two blood samples and from two dialysate samples were calculated. RESULTS: Kt/V values calculated according to Daugirdas 2 nd generation formula from blood samples (Kt/V sp Daugirdas) were in significant correlation with all Kt/V values obtained from two spent dialysate samples. The highest correlation coefficient (r = 0.74, p < 0.001) and the least standard error of mean of the differences were found between Kt/V sp Daugirdas and value obtained with substitution of urea concentration from dialysate samples taken 60 minutes after dialysis start and at the end of the dialysis into Daugirdas 2 nd generation formula (Kt/V D C D(60) -C D(e) ), which can be expressed as a equation of linear regression y = 0.47 + 0.86x. The highest correlation coefficient (r =0.74, p < 0.001) was found between Kt/V sp Daugirdas values equilibrated according to Daugirdas rate formula, and Kt/V D C D(60) -C D(e) value, which can also be expressed as an equation of linear regression y = 0.43 + 0.73x. CONCLUSION: The results of this study clearly show the sufficiency of only two spent dialysate samples for direct estimation of the Kt/V values, with no blood sample required.

Adult↗
PubMed2005

Evaluation of a PCR to detect Salmonella in fecal samples of horses admitted to a veterinary teaching hospital.

The diagnostic accuracy of a PCR used to identify horses shedding Salmonella spp. in their feces during hospitalization was estimated, relative to bacterial culture of serially collected fecal samples, using longitudinal data. Five or more fecal samples were collected from each of 116 horses admitted as inpatients, for reasons other than gastrointestinal disease, between July 26, 2001 and October 25, 2002. All 873 fecal samples collected were tested with a PCR based on oligonucleotide primers defining a highly conserved segment of the histidine transport operon gene of Salmonella typhimurium, and each sample was cultured for Salmonella spp. One or more samples from 87 (75%) horses were PCR positive, and Salmonella was cultured from 1 or more samples from 11 (9.5%) horses. All culture-positive horses had at least 1 PCR-positive result, whereas only 29 (28%) culture-negative horses were PCR negative on all fecal samples tested. The PCR was most specific, relative to bacterial culture of serially collected fecal samples, when used to test samples from Quarterhorse or breeds other than Thoroughbred or Standardbred, or from clinical (vs. healthy, accompanying horses) cases. Overall, the PCR had the greatest agreement (70%), compared with bacterial culture of serially collected fecal samples, using a cutoff of 2 or more positive PCR test results to define a Salmonella-positive horse. The reasons why some fecal samples, from which Salmonella organisms cannot be isolated, are PCR positive need to be determined before the PCR can be incorporated into Salmonella surveillance programs for hospitalized equine populations.

Animals↗
PubMed2005

Comparison of individual and pooled sampling methods for detecting bacterial pathogens of fish.

Examination of finfish populations for viral and bacterial pathogens is an important component of fish disease control programs worldwide. Two methods are commonly used for collecting tissue samples for bacteriological culture, the currently accepted standards for detection of bacterial fish pathogens. The method specified in the Office International des Epizooties Manual of Diagnostic Tests for Aquatic Animals permits combining renal and splenic tissues from as many as 5 fish into pooled samples. The American Fisheries Society (AFS) Blue Book/US Fish and Wildlife Service (USFWS) Inspection Manual specifies the use of a bacteriological loop for collecting samples from the kidney of individual fish. An alternative would be to more fully utilize the pooled samples taken for virology. If implemented, this approach would provide substantial savings in labor and materials. To compare the relative performance of the AFS/USFWS method and this alternative approach, cultures of Yersinia ruckeri were used to establish low-level infections in groups of rainbow trout (Oncorhynchus mykiss) that were sampled by both methods. Yersinia ruckeri was cultured from 22 of 37 groups by at least 1 method. The loop method yielded 18 positive groups, with 1 group positive in the loop samples but negative in the pooled samples. The pooled samples produced 21 positive groups, with 4 groups positive in the pooled samples but negative in the loop samples. There was statistically significant agreement (Spearman coefficient 0.80, P < 0.001) in the relative ability of the 2 sampling methods to permit detection of low-level bacterial infections of rainbow trout.

Animals↗
PubMed2006

Critical points of DNA quantification by real-time PCR--effects of DNA extraction method and sample matrix on quantification of genetically modified organisms.

BACKGROUND: Real-time PCR is the technique of choice for nucleic acid quantification. In the field of detection of genetically modified organisms (GMOs) quantification of biotech products may be required to fulfil legislative requirements. However, successful quantification depends crucially on the quality of the sample DNA analyzed. Methods for GMO detection are generally validated on certified reference materials that are in the form of powdered grain material, while detection in routine laboratories must be performed on a wide variety of sample matrixes. Due to food processing, the DNA in sample matrixes can be present in low amounts and also degraded. In addition, molecules of plant origin or from other sources that affect PCR amplification of samples will influence the reliability of the quantification. Further, the wide variety of sample matrixes presents a challenge for detection laboratories. The extraction method must ensure high yield and quality of the DNA obtained and must be carefully selected, since even components of DNA extraction solutions can influence PCR reactions. GMO quantification is based on a standard curve, therefore similarity of PCR efficiency for the sample and standard reference material is a prerequisite for exact quantification. Little information on the performance of real-time PCR on samples of different matrixes is available. RESULTS: Five commonly used DNA extraction techniques were compared and their suitability for quantitative analysis was assessed. The effect of sample matrix on nucleic acid quantification was assessed by comparing 4 maize and 4 soybean matrixes. In addition 205 maize and soybean samples from routine analysis were analyzed for PCR efficiency to assess variability of PCR performance within each sample matrix. Together with the amount of DNA needed for reliable quantification, PCR efficiency is the crucial parameter determining the reliability of quantitative results, therefore it was chosen as the primary criterion by which to evaluate the quality and performance on different matrixes and extraction techniques. The effect of PCR efficiency on the resulting GMO content is demonstrated. CONCLUSION: The crucial influence of extraction technique and sample matrix properties on the results of GMO quantification is demonstrated. Appropriate extraction techniques for each matrix need to be determined to achieve accurate DNA quantification. Nevertheless, as it is shown that in the area of food and feed testing matrix with certain specificities is impossible to define strict quality controls need to be introduced to monitor PCR. The results of our study are also applicable to other fields of quantitative testing by real-time PCR.

DNA, Plant↗
PubMed2006

Quantification of damage in DNA recovered from highly degraded samples--a case study on DNA in faeces.

BACKGROUND: Poorly preserved biological tissues have become an important source of DNA for a wide range of zoological studies. Measuring the quality of DNA obtained from these samples is often desired; however, there are no widely used techniques available for quantifying damage in highly degraded DNA samples. We present a general method that can be used to determine the frequency of polymerase blocking DNA damage in specific gene-regions in such samples. The approach uses quantitative PCR to measure the amount of DNA present at several fragment sizes within a sample. According to a model of random degradation the amount of available template will decline exponentially with increasing fragment size in damaged samples, and the frequency of DNA damage (lambda) can be estimated by determining the rate of decline. RESULTS: The method is illustrated through the analysis of DNA extracted from sea lion faecal samples. Faeces contain a complex mixture of DNA from several sources and different components are expected to be differentially degraded. We estimated the frequency of DNA damage in both predator and prey DNA within individual faecal samples. The distribution of fragment lengths for each target fit well with the assumption of a random degradation process and, in keeping with our expectations, the estimated frequency of damage was always less in predator DNA than in prey DNA within the same sample (mean lambda(predator) = 0.0106 per nucleotide; mean lambda(prey) = 0.0176 per nucleotide). This study is the first to explicitly define the amount of template damage in any DNA extracted from faeces and the first to quantify the amount of predator and prey DNA present within individual faecal samples. CONCLUSION: We present an approach for characterizing mixed, highly degraded PCR templates such as those often encountered in ecological studies using non-invasive samples as a source of DNA, wildlife forensics investigations and ancient DNA research. This method will allow researchers to measure template quality in order to evaluate alternate sources of DNA, different methods of sample preservation and different DNA extraction protocols. The technique could also be applied to study the process of DNA decay.

Journal Article↗
PubMed2003

Effect of number of lymph nodes sampled on outcome in patients with stage I non-small-cell lung cancer.

PURPOSE: We postulate that surgical sampling and pathologic evaluation of lymph nodes of surgical specimens from patients with stage I non-small-cell lung cancer (NSCLC) can have an effect on the time to recurrence and survival of these patients. PATIENTS AND METHODS: We analyzed data on 442 patients with stage I NSCLC who were treated with surgical resection and some form of lymph node sampling. Associations between total lymph nodes sampled and disease-free survival (DFS) and overall survival (OS) were investigated. The effect of total lymph node stations sampled and the surgical techniques (random lymph node sampling, systematic sampling [SS], or complete mediastinal lymph node dissection [MLND]) on DFS and OS was also studied. Complete MLND and SS were defined as dissection or sampling of levels 4, 7, and 10 for right-sided lesions and levels 5 or 6 and 7 for left-sided lesions. RESULTS: Patients were divided into quartiles on the basis of total number of lymph nodes sampled. Improved DFS and OS were associated with greater number of lymph nodes sampled. SS and MLND were associated with improved survival compared with random lymph node sampling. The total number of lymph nodes sampled maintained strong significance in the multivariate analysis. CONCLUSION: These results indicate that examining a greater number of lymph nodes in patients with stage I NSCLC treated with resection increases the likelihood of proper staging and affects patient outcome. Such information is important not only for therapy and prognosis of individuals but also for identifying those who may benefit from adjuvant therapy.

Adult↗
PubMed2005

Blood sampling from the cranial vena cava in the Norway rat (Rattus norvegicus).

This paper describes blood sampling from the cranial vena cava (CVC) in the Norway rat. In order to limit stress, the blood sampling should be done under short-term inhalation anaesthesia, for example, an oxygen/isoflurane mixture. The injection site is just cranial to the first rib, 0.3-0.8 cm lateral to the manubrium when the animal is in dorsal recumbency. The needle, attached to a syringe, is inserted at 30 degrees in the direction of the opposite femoral head. After penetration of the skin, negative pressure is developed in the syringe and the insertion of the needle is continued for another 0.2-1 cm in the given direction until blood begins to flow. The amount of blood sampled ranges from 0.8 to 2.5 mL depending on the body weight of the patient. A trial on 50 rats aged 5-24 months included 25 rats sampled once, eight rats sampled twice with an interval of seven days, 11 rats sampled twice with an interval of three weeks and four rats sampled four times with intervals of four weeks--a total of 87 blood samplings. The serious complications quoted in association with blood sampling from the CVC in other experimental animals (vascular lacerations, heart puncture, serious haemorrhage, tracheal and throat trauma) were not observed in our study. There were only four blood samplings (4.5%) with mild haemorrhage from the injection site, due to erroneous sampling from the jugular vein.

Anesthesia, Inhalation↗
PubMed1995

Issues associated with the design of a national probability sample for human exposure assessment.

Data obtained from national probability sample surveys provide important information on the prevalence of various health conditions and distributions of physical and biochemical characteristics of the U.S. population. The sample design of a survey specifies how sampling from a designated population over a stated period is to be accomplished. A survey's analytical objectives and interests--in particular subpopulations--affect the sample design strategy. Selected subdomains of the population often must be oversampled so that estimates can be made with acceptable precision. This article addresses sample design considerations for a national probability sample for human tissue monitoring and specimen banking. Among the sampling issues addressed are the oversampling of special populations e.g., minority groups and at-risk groups such as low income or elderly persons; geographic coverage; and sample size considerations. The sample design for a major health survey, the Third National Health and Nutrition Examination Survey (NHANES III), is used to illustrate a complex, multistage probability sample design and to highlight some of the sampling issues discussed in this article.

Data Collection↗
PubMed2003

Optimal sampling strategies to assess inulin clearance in children by the inulin single-injection method.

BACKGROUND: Glomerular filtration rate in patients can be determined by estimating the plasma clearance of inulin with the single-injection method. In this method, a single bolus injection of inulin is administered and several blood samples are collected. For practical and convenient application of this method in children, it is important that a minimal number of samples are drawn. The aim of this study was to develop and validate sampling strategies with fewer samples for reliable prediction of inulin clearance in pediatric patients by the inulin single-bolus-injection method. METHODS: Complete inulin plasma concentration-time curves of 154 patients were divided into an index (n = 100) and a validation set (n = 54). A population pharmacokinetic model was developed for the index set. Optimal sampling times were selected based on D-optimality theory. For the validation set, Bayesian estimates of clearance were generated using the derived population parameters and concentrations at two to four sampling times. Bayesian estimates of clearance were compared with the individual reference values of clearance. RESULTS: The strategies with samples taken at 10/30/90/240 min, 10/30/240 min, 10/90/240 min, 30/90/240 min, and 90/240 min allowed accurate prediction of inulin clearance (bias <3% and not significantly different from 0; imprecision <15%). CONCLUSIONS: Strategies involving two to four samples, including a sample at 240 min after administration of inulin, in the inulin single-injection method allow accurate prediction of inulin clearance in pediatric patients. Even one blood sample at 240 min showed acceptable performance. The proposed strategies are practical and convenient to children, and reduce repetitive blood sampling without compromising accuracy.

Adolescent↗
PubMed1992

Comparison between bronchial and alveolar samples of bronchoalveolar lavage fluid in asthma.

BACKGROUND: Cell content of BALF may vary according to the segment of the lung washed. It was proposed to separate BALF into several aliquots, the first sample being more related to bronchi. The present study compared bronchial and alveolar samples by fractionating aliquots of BALF in normal and asthmatic subjects. METHODS: One hundred asthmatic subjects (mean +/- SEM: 37 +/- 1.5 yr in age) were compared with 31 normal subjects (mean +/- SEM: 32 +/- 2.2 yr in age). None of the subjects was a smoker and none was taking drugs that might interfere with the results. The severity of asthma was defined by the clinical score of Aas examining the chronic severity of asthma and ranging from 1 to 5 (range: 1 to 4; mean +/- SEM: 2.2 +/- 0.1) and FEV1 (range: 45 to 130 percent; mean +/- SEM: 82 +/- 1.8 percent of predicted values). Bronchoscopy was done in a standardized manner. A first aliquot of 50 ml of saline each were instilled and the BALF recovered was pooled (alveolar sample). After centrifugation, total and differential cell counts (May Grünwald-Giemsa) were carried out on bronchial and alveolar samples. RESULTS: The alveolar sample contained significantly more cells per milliliter of BALF than the bronchial sample in normal (p less than 0.0077, Wilcoxon test) and in asthmatic subjects (p = 0.0001, Wilcoxon test). Both in normal and asthmatic subjects, bronchial samples contained significantly more neutrophils and epithelial cells and fewer macrophages and lymphocytes than alveolar samples. In asthmatic subjects, the bronchial sample contained a significantly greater percentage of eosinophils than the alveolar sample. Eosinophils were significantly increased in asthmatic subjects for both the bronchial and alveolar samples. Bronchial and alveolar eosinophilia both were correlated with the Aas score (r = 0.25, p = 0.024 and r = 0.38, p = 0.0006, respectively, by Spearman Rank test). CONCLUSIONS: This study shows in a large number of subjects that the cell content of bronchial and more distal segments of the lung is not comparable, indicating that studies should not give pooled data in asthmatic subjects. Moreover, it confirms the presence of BALF eosinophilia in asthmatic subjects.

Adolescent↗
PubMed2000

Presence-absence sequential sampling plan for northern fowl mite, Ornithonyssus sylviarum (Acari: Macronyssidae), on caged-layer hens.

Caged-layer hens were scored as infested or uninfested by visual examination of the vent region, and the number of northern fowl mite, Ornithonyssus sylviarum (Canestrini & Fanzago), per hen was estimated. The proportion infested and average number of mites per hen were shown to have a highly significant, positive relationship (r = 0.936). Sampling among houses within a flock, and rows and sections within houses were analyzed to determine the reliability of sampling a representative portion of a flock. Low- and moderate-tolerance treatment thresholds, based on percentage of hens infested with mites, were developed from sampling 1 wk before and 1 wk after acaricide treatments determined necessary by the producer. These thresholds were used to compare a fixed (single) sampling plan, a curtailed procedure of the fixed sampling plan, and a sequential sampling plan based on a sequential probability ratio test, by sampling 174 hens (the maximum number needed for the single sampling plan). The sequential sampling plan required fewer hen examinations on average to reach a treatment decision than did the other plans, depending on the infestation tolerance limits. Using a low tolerance approach in which infestations below 15% are considered noneconomic (safe threshold) and infestations above 25% are considered economically important (action threshold), as few as 5 hens required examination to reach a treatment decision. Sequential sampling plan graphs are presented for 2 tolerance threshold scenarios (a 15% safe-threshold paired with a 25% action threshold and a 35% safe-threshold paired with a 45% action threshold). These sequential sampling plans using presence absence assessments should greatly facilitate monitoring and treatment decisions for this important pest.

Animals↗
PubMed2002

The development of emergent differential sample behavior in pigeons.

Three experiments attempted to replicate Manabe, Kawashima, and Staddon's (1995) finding of emergent differential sample behavior in budgerigars that has been interpreted as evidence of functional equivalence class formation. In Experiments 1 and 2, pigeons initially learned two-sample/ two-alternative matching to sample in which comparison presentation was contingent on pecking one sample on a differential-reinforcement-of-low-rate (DRL) schedule and the other on a fixed-ratio (FR) schedule. Later, two new samples were added to the task. Comparison presentation on these trials occurred after the first sample peck following a predetermined interval (Experiment 1) or after completion of either the DRL or FR requirement, whichever occurred first (Experiment 2). Experiment 1 found no evidence for emergent spaced versus rapid responding to the new samples as they established conditional control over the familiar choices. By contrast, differential responding did emerge for some pigeons in Experiment 2, with responding to each new sample coinciding with the pattern explicitly conditioned to the original sample occasioning the same comparison choice. This emergent effect, however, disappeared for most pigeons with continued training. Experiment 3 systematically replicated Experiment 2 using differential peck location as the sample behavior. Differential location pecking emerged to the new samples for most pigeons and remained intact throughout training. Our findings demonstrate a viable pigeon analogue to the budgerigar emergent calling paradigm and are discussed in terms of equivalence- and non-equivalence-based processes.

Animals↗
PubMedDate not supplied

Assessment of glycosylated hemoglobin measurement with sample collection papers.

It would be advantageous to be able to measure glycosylated hemoglobin (GHb) from a sample of blood dried on paper and sent to the physician by the patient. Indeed, such a technique has been introduced by Isolab (Akron, OH). We tested the validity of the method to determine whether applying the blood to paper and immediately assaying it correlates with the same sample assayed by the usual whole-blood technique, the size of sample applied to paper affects apparent GHb results, time and temperature of storage of the sample paper affect apparent GHb results, and plasma glucose concentration of the sample affects GHb results. The GHb of samples assayed immediately after application to sample paper versus those assayed as whole blood showed very good correlation (r = .93, P less than .001). Volume of the drop of blood applied to paper (25-100 microliters) did not affect results. However, there was a dramatic, temperature-dependent increase in apparent GHb when samples were stored on sample paper, averaging 12.5, 16.3, and 19.5% when stored at room temperature for 3, 6, and 9 days, respectively. Overall, apparent GHb rose from 1.3-fold in 3 days at 4 degrees C to 3.8-fold in 9 days at 37 degrees C. The rate of GHb formation was proportional to plasma glucose concentration, but removal of free glucose by ethanol or glucose oxidase did not yield consistent results for this method. We conclude that these sample papers are not useful as an approach to collecting blood samples for GHb measurement.

Blood Glucose↗