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Diagnosis of rickettsial diseases using samples dried on blotting paper.

The use of filter paper is an inexpensive and convenient method for collecting, storing, and transporting blood samples for serological studies. In addition, samples occupy little space and can be readily transported without refrigeration. Rickettsial diseases often evolve according to an epidemic mode and are now considered reemerging diseases, especially in developing countries, under conditions where fieldwork could be difficult. The suitability of collecting whole-blood specimens on filter paper discs for rickettsial antibody assay was evaluated. Dried blood specimens from 64 individuals with antibodies to Coxiella burnetii, Bartonella quintana, or Rickettsia conorii were tested for rickettsial antibodies by microimmunofluorescence. Although occasional titers were 1 or 2 dilutions lower than those of tested serum samples, no statistically significant differences were observed. Among patients with negative serology, no false positives were found. This study demonstrated that the recovery of antibodies from finger-stick blood dried on filter paper after elution produces results comparable to those obtained by recovering antibodies from serum. Storing paper samples for 1 month at room temperature or at 4 degrees C did not significantly affect the level of antibodies recovered. This report shows the utility of this sample collection method in developing countries where refrigeration is not possible and venipuncture is problematic.

Antibodies, Bacterial↗

New paper enzyme-linked immunosorbent technique compared with microimmunofluorescence for detection of human serum antibodies to Rickettsia tsutsugamushi.

A new paper enzyme-linked immunosorbent assay was developed for the screening and titration of human serum antibodies against the scrub typhus rickettsia, Rickettsia tsutsugamushi. The objective [corrected] was to provide a relatively simple method for antibody screening which required neither sophisticated laboratory equipment nor a high degree of technological skill. The technique develops an enzyme product from filter paper saturated with a 5-aminosalicylic acid substrate and enzymatically reacted with a commerically available anti-human immunoglobulin G peroxidase conjugate. The product of the enzymatic reaction can be interpreted visually. Comparison of 351 human sera tested by the immunofluorescent and paper enzyme-linked immunosorbent assays against a three-antigen pool of the Karp, Kato, and Gilliam strains of R. tsutsugamushi demonstrated an agreement of 96%. The sensitivity of the paper enzyme-linked immunosorbent assay as compared to immunofluorescence was 98.2%, and the specificity was 94.4%.

Antibodies, Bacterial↗

Comparison of paired whole milk and dried filter paper samples for anti-enterotoxin and anti-rotavirus activities.

Milk specimens, 75 from cows immunized against cholera toxin and 35 from a human population in which enterotoxigenic Escherichia coli and rotaviral infections are endemic, were collected as paired filter paper and frozen whole milk samples. Each pair was tested for antibody activity against heat-labile E. coli and Vibrio cholerae enterotoxins. Additionally, 12 of the 35 paired human milk samples stored as frozen whole milk and dried on filter paper were tested for anti-rotavirus immunoglobulin A. Anti-enterotoxin and anti-rotavirus immunoglobulin A titers in milk dried on filter paper compared favorably with those of their frozen whole milk pairs. Filter paper samples offered considerable advantages for field collection, transportation, and storage over frozen liquid samples.

Animals↗

Preserving the sterility of surgical dressings wrapped in paper and other materials.

Materials for wrapping surgical dressings were studied by a method which measured the recontamination rate in packs stored for periods of up to several weeks. Of the materials tested a thick crêpe paper was better than calico and balloon cloth fabrics. Dressings wrapped in paper were not significantly contaminated after storage in dusty places for periods of up to three weeks. For added protection during handling and for convenience in transport and storage, paper packs may be sterilized and kept in paper-lined cartons. The shelf life in good storage conditions would be many weeks at least.

Bandages↗

Mortality from asthma and chronic obstructive pulmonary disease among workers in a soft paper mill: a case-referent study.

In a case-referent study encompassing 33 cases and 228 referents the potential risk for asthma and chronic obstructive pulmonary disease and respiratory cancer among workers in a soft paper mill was evaluated. The cases were selected from registers of deaths and burials in the parishes around the paper mill. Information on exposure was obtained from the personnel register of the mill but because of shortage of information the cases could only be classified as "exposed" or "non-exposed." At some places in the mill the concentrations of paper dust had previously been high, 10-30 mg/m3. Employment at the paper mill was found to be associated with an increased risk of bronchial asthma and chronic obstructive pulmonary disease (odds ratio = 3.8, p less than 0.05).

Adult↗

Continuous image recording using gray-tone, dry-process silver paper.

A method of recording continuous gray-tone images on dry-process silver paper from raster-scan video signals is described. The Tektronix 4634 image-forming module uses a fiber-optic faceplate cathode-ray tube to couple the light output onto the recording paper. The latent image is heat developed and presented in sheet form. An initial comparison between dry silver paper and conventional film for video-generated computed tomography and nuclear medicine examinations, shows little apparent difference in image quality. Considerable cost savings are possible when using dry silver paper. Additional cost savings are possible if multiple images can be recorded on each dry silver sheet.

Costs and Cost Analysis↗

Phage typing of mycobacteria using paper discs.

The suitability of phage-impregnated paper discs for the phage typing of mycobacteria was studied. The relevance of the routine test dilution, the volume of the phage used, the mode of incubation, and the effect of prolonged storage of phage-impregnated paper discs were considered. By using paper discs, each impregnated with one of 5 different mycobacteriophages (BG1, BK1, G37, CRI-3 and LG) that lyse Mycobacterium smegmatis 607B, it was determined that 100 x the routine test dilution in a volume of at least 20 microliter was required for phage lysis. Soaked and dried paper discs produced larger areas of lysis than those with 20-microliter volumes. Soaked discs were found to be stable even after storage for 8 weeks at 4 degrees C.

Bacteriological Techniques↗

Performance of three enzymic methods for filter paper glucose determination.

Collection of blood spots on filter paper offers a practical alternative for home monitoring of diabetic patients. We have compared the merits of three protein precipitants, trichloracetic acid (TCA), perchloric acid (PCA) and sulphosalicylic acid (SSA) for the elution of glucose from the filter paper, and their subsequent effects on three enzymic methods, glucose dehydrogenase (GDH), hexokinase (HK), and glucose oxidase (GOD) for the determination of glucose using a microcentrifugal analyser. The combination of TCA elutant with the GDH method was superior with respect to time course of reaction and elution time from the filter paper, and was chosen for routine use. Within- and between-batch precision for this method was 2.7% and 3.2% respectively at normal glucose concentrations. Recovery of glucose added to whole blood was 110 +/- 5%. Comparison with an automated glucose oxidase method for plasma glucose gave a slope of 1.1, intercept of -0.7 and a correlation coefficient of 0.9 (n = 64). We conclude that the combination of TCA and glucose dehydrogenase provides a robust, precise and accurate method for the quantitation of glucose in filter-paper blood spots. The procedure offers increased sensitivity and better precision than GOD methods. The use of TCA as elutant gives a faster elution time and has the least effect on any of the enzymic methods.

Blood Glucose↗

Collecting, archiving and processing DNA from wildlife samples using FTA databasing paper.

BACKGROUND: Methods involving the analysis of nucleic acids have become widespread in the fields of traditional biology and ecology, however the storage and transport of samples collected in the field to the laboratory in such a manner to allow purification of intact nucleic acids can prove problematical. RESULTS: FTA databasing paper is widely used in human forensic analysis for the storage of biological samples and for purification of nucleic acids. The possible uses of FTA databasing paper in the purification of DNA from samples of wildlife origin were examined, with particular reference to problems expected due to the nature of samples of wildlife origin. The processing of blood and tissue samples, the possibility of excess DNA in blood samples due to nucleated erythrocytes, and the analysis of degraded samples were all examined, as was the question of long term storage of blood samples on FTA paper. Examples of the end use of the purified DNA are given for all protocols and the rationale behind the processing procedures is also explained to allow the end user to adjust the protocols as required. CONCLUSIONS: FTA paper is eminently suitable for collection of, and purification of nucleic acids from, biological samples from a wide range of wildlife species. This technology makes the collection and storage of such samples much simpler.

Animals↗

Suitability of resin-coated photographic paper for skin dose measurement during fluoroscopically-guided X-ray procedures.

The need for mapping skin doses during fluoroscopically-guided X-ray procedures has been described by a number of institutions and experts. Different large photographic or X-ray films placed on the patient's skin have been found to be useful for recording doses up to 1.0-2.0 Gy - depending on the film - and up to 15 Gy using radiochromic films. Though the upper limit of the film sensitivity is seldom exceeded during interventional procedures, the main disadvantage of the X-ray films is still the excessive sensitivity for long, high dose procedures. Radiochromic films show poor definition for doses below 0.5 Gy and are expensive. The goal of the present paper is to analyse the possibilities of using common resin-coated photographic paper for this purpose. Sensitometric curves obtained with different paper types processed in conventional X-ray film automatic processors demonstrate that some of them can be used with better results than X-ray films at a very low cost. Doses from about 10 mGy to near 3.0 Gy can be measured with good accuracy using a variety of glossy photographic papers.

Dose-Response Relationship, Radiation↗

Analysis of pyrimidine synthesis "de novo" intermediates in urine and dried urine filter- paper strips with HPLC-electrospray tandem mass spectrometry.

BACKGROUND: The concentrations of the pyrimidine "de novo" metabolites and their degradation products in urine are useful indicators for the diagnosis of an inborn error of the pyrimidine de novo pathway or a urea-cycle defect. Until now, no procedure was available that allowed the analysis of all of these metabolites in a single analytical run. We describe a rapid, specific method to measure these metabolites by HPLC-tandem mass spectrometry. METHODS: Urine or urine-soaked filter-paper strips were used to measure N-carbamyl-aspartate, dihydroorotate, orotate, orotidine, uridine, and uracil. Reversed-phase HPLC was combined with electrospray ionization tandem mass spectrometry, and detection was performed by multiple-reaction monitoring. Stable-isotope-labeled reference compounds were used as internal standards. RESULTS: All pyrimidine de novo metabolites and their degradation products were measured within a single analytical run of 14 min with lower limits of detection of 0.4-3 micromol/L. The intra- and interassay variation for urine with added compounds was 1.2-5% for urines and 2-9% for filter-paper extracts of the urines. Recoveries of the added metabolites were 97-106% for urine samples and 97-115% for filter-paper extracts of the urines. Analysis of urine samples from patients with a urea-cycle defect or pyrimidine degradation defect showed an aberrant metabolic profile when compared with controls. CONCLUSION: HPLC with electrospray ionization tandem mass spectrometry allows rapid testing for disorders affecting the pyrimidine de novo pathway. The use of filter-paper strips could facilitate collection, transport, and storage of urine samples.

Argininosuccinic Aciduria↗

A comparison of Web- with paper-based surveys of gay and bisexual men who vacationed in a gay resort community.

Internet Web page survey responses were compared with those collected using traditional paper-and-pencil strategies to assess relative inclusion of a geographically dispersed population and comparativeness in responses. Three hundred and seven gay or bisexual men who had vacationed in a particular gay community completed Web-based and 244 paper-and-pencil questionnaires. Each questionnaire contained the same wording and question order. More Internet respondents than paper reported bisexual identity, nonmetropolitan residence, greater numbers of nonmain male partners for unprotected anal intercourse, and alcohol use than did paper-and-pencil respondents. Few other differences were identified. Assessing the reach of survey distribution can add to our knowledge base of surveys fielded using the Internet. Similarly, examining the potential biases in modes of administering convenience surveys can assist researchers to select the survey data collection method most appropriate to their research goals and design studies to assess the effect of the methods that are used.

Bisexuality↗

Bioluminescence inhibition assays for toxicity screening of wood extractives and biocides in paper mill process waters.

The risk associated with wood extractives, biocides, and other additives in pulp and paper mill effluents was evaluated by performing a characterization of process waters and effluents in terms of toxicity and chemical analysis. The individual toxicity of 10 resin acids, two unsaturated fatty acids, and three biocides was estimated by measuring the bioluminescence inhibition with a ToxAlert 100 system. Median effective concentration values (EC50) of 4.3 to 17.9, 1.2 to 1.5, and 0.022 to 0.50 mg/L were obtained, respectively. Mixtures of these three families of compounds showed antagonistic effects. Chemical analysis of process waters was performed by liquid chromatography- and gas chromatography-mass spectrometry. Biocides such as 2-(thiocyanomethylthio)-benzotiazole (TCMTB) (EC50 = 0.022 mg/L) and 2,2-dibromo-3-nitrilpropionamide (DBNPA) (EC50 = 0.50 mg/L) were the most toxic compounds tested and were detected at concentrations of 16 and 59 microg/L, respectively, in a closed-circuit recycling paper mill. Process waters from kraft pulp mills, printing paper mills, and packing board paper mills showed the highest concentration of resin acids (up to 400 microg/L) and accounted for inhibition percentages up to 100%. Detergent degradation products such as nonylphenol (NP) and octylphenol (OP) and the plasticizer bisphenol A (BPA) were also detected in the waters at levels of 0.6 to 10.6, 0.3 to 1.4, and 0.7 to 187 microg/L, respectively. However, once these waters were biologically treated, the concentration of detected organic compounds diminished and the toxicity decreased in most cases to values of inhibition lower than 20%.

Abietanes↗

Fecal contamination in child day care centers: cloth vs paper diapers.

OBJECTIVES: Cloth diapers with front closure and all-in-one design were compared with paper diapers containing absorbent gel material for their influence on fecal contamination of the environment in licensed child day care centers. METHODS: One infant room and two toddler rooms in each of four day care centers were monitored for the presence of fecal bacteria. Microbial samples were taken from the play/sleep area, the diaper-changing area, and the hands of the caregivers and the children. Sampling was done twice weekly for two 4-week periods. Each center used either cloth or paper diapers during the first period, changing to the other diaper type during the second period. RESULTS: A total of 1722 samples were cultured, 881 during the first 4 weeks and 841 during the second 4 weeks. The frequency of isolation of fecal organisms ranged from a low of 12% of the total bacteria isolates at a center using cloth diapers, to highs of 46% and 45%, respectively, at a center using first paper and then cloth diapers. Sink faucets and the hands of the caregivers and the children were often contaminated. CONCLUSIONS: Analysis of the results of comparisons between cloth and paper diapers showed no significant difference in the frequency (F = .380, P < .535) or the intensity of fecal contamination in child day care centers.

Bacteria↗

Accuracy of a filter paper method for measuring glycosylated hemoglobin.

OBJECTIVE: To compare glycosylated hemoglobin (GH) results obtained by filter paper fingerstick collection and mailed for assay by affinity chromatography with results from a venous sample assayed by ion-exchange chromatography (HbA1) in a local laboratory. RESEARCH DESIGN AND METHODS: Fifty-eight volunteer subjects with insulin-dependent diabetes mellitus (IDDM), aged 5-24 yr, included patients at a referral-based IDDM clinic and subjects in an ongoing research study. We obtained two blood samples from each subject. One was collected by fingerstick onto filter paper, the other by venipuncture into a vacutainer. We sent filter paper samples to the Diabetes Research Laboratory (Univ. of Missouri, Columbia, MO) for analysis. Vacutainer samples were sent to the Clinical Chemistry Department of the Clinical Laboratory, University of Colorado Health Sciences Center. RESULTS: Results were highly correlated (r = 0.89, P = 0.0001). Fifty-nine percent were classified identically when results were normalized to SD units and grouped to suggest levels of clinical concern. CONCLUSIONS: The filter paper method is a convenient, accurate measure of glycosylated hemoglobin in young people with IDDM. It should be considered a credible alternative research and clinical tool.

Adolescent↗

A procedure for drug screening without the need to transport urines: use of ion exchange papers and hemagglutination inhibition.

A procedure was devised for screening for drug abuse in urine specimens by adsorbing the drugs onto papers loaded with ion-exchange resin. The drugs were then eluted from the papers into aqueous saline buffers, which were analyzed by hemagglutination inhibition with antisera specific for morphine, methadone, or barbiturates. The procedure combines the convenience of the ion-exchange papers with the precision and sensitivity of the immunoassay. The preliminary treatment consists of local treatment of urine specimens collected at many distant clinics with ion exchange papers that adsorb 50-65% of alkaloid drugs and 25% of barbiturates and can be shipped, after drying, in simple envelopes by regular mail to a central analytical laboratory for processing. At the central laboratory, portions of specimens are reconstituted in aqueous saline buffers, while drugs from other portions are extracted with solvents at appropriate pH. Drugs are detected in the reconstituted aqueous media by hemagglutination inhibition and spectrophotofluorimetry and confirmed in the solvent extracts by thin-layer chromatography. Recovery of labeled drugs after this treatment and urine screening data showed that the procedure is safe, convenient, and reliable in the case of opiate alkaloids, methadone, amphetamines, and phenothiazine tranquilizers but is less suitable for detection of barbiturates.

Chromatography, Ion Exchange↗

Bleed fastness of fluorescent whitening agents in mass whitened paper.

Paper samples mass whitened with fluorescent whiteing agents (FWAs) of three different types (di-, tetra-, and hexasulfonated derivatives of 4,4'-diaminostilbene-2,2'-disulfonic acid) were examined for bleed fastness in five different eluents. Fluorescece intensity was measured by a sensitive spectrofluorimetric technique instead of the usual visual assessment. The degree of bleed obtained from each of the FWAs tested was less than 0.4mg/600 cm2 of paper surface area. The FWAs were applied at a normal concentration of use i.e. 0.05% active substance. FWAs with a high degree of sulfonation tend to bleed in aqueous solvents, and those with a lower degree of sulfonation in alcohol solutions. In aqueous acid solutions the degree of bleed was very low in all cases (0.04 mg/600 cm2 of paper surface area). In fatty solutions there was no bleed at all. The limit of detection was 3mug/600 cm2 of paper surface area, with an accuracy of +/-15%.

Coloring Agents↗

Defects in pyrimidine degradation identified by HPLC-electrospray tandem mass spectrometry of urine specimens or urine-soaked filter paper strips.

BACKGROUND: Urinary concentrations of thymine, uracil, and their degradation products are useful indicators of deficiencies of enzymes of the pyrimidine degradation pathway. We describe a rapid, specific method to measure these concentrations to detect inborn errors of pyrimidine metabolism. METHODS: We used urine or urine-soaked filter-paper strips as samples and measured thymine, uracil, and their degradation products dihydrothymine, dihydrouracil, N:-carbamyl-ss-aminoisobutyric acid, and N:-carbamyl-ss-alanine. Reversed-phase HPLC was combined with electrospray ionization tandem mass spectrometry, and detection was performed by multiple-reaction monitoring. Stable-isotope-labeled reference compounds were used as internal standards. RESULTS: All pyrimidine degradation products could be measured in one analytical run of 15 min. Detection limits were 0.4-4 micromol/L. The intraassay imprecision (CV) of urine samples with added compounds was 1.3-12% for liquid urines and 1. 0-10% for filter-paper extracts of the urines. The interassay imprecision (CV) was 3-11% (100-200 micromol/L). Recoveries were 89-99% at 100-200 micromol/L and 95-106% at 1 mmol/L in liquid urines, and 93-103% at 100-200 micromol/L and 100-106% at 1 mmol/L in filter-paper samples. Correct identifications of deficiencies of the pyrimidine-degrading enzymes were readily made with urine samples from patients with known defects. CONCLUSIONS: HPLC with electrospray ionization tandem mass spectrometry allows rapid testing for disorders of the pyrimidine degradation pathway, and filter-paper samples allow easy collection, transport, and storage of urine samples.

Chromatography, High Pressure Liquid↗