TM Test Research Articles

Evaluation of the ColiMast™ Test for Detection of Coliform Mastitis in Dairy Cattle

Since the distribution of pathogens causing clinical mastitis varies widely among dairy herds, a rapid and accurate method of determining the type of pathogen involved would be useful. The ColiMast™ test consists of selective growth media in a vial. After incubation, a color change indicates the presence of coliform organisms. This research evaluated characteristics of the ColiMast TM test for detecting coliform organisms in clinical mastitis milk samples and as a diagnostic aid in a mastitis treatment decision-making protocol.

Preliminary toxicity assessment of water after treatment with uv-irradiation and UVC/H 2O 2

Photooxidation (UV radiation) and enhanced photooxidation (UVC/H 2O 2) are water treatment technologies which remove aquatic natural organic matter (NOM) by photodegradation, producing lower molecular weight components and CO 2. Since these technologies are being investigated for the treatment of drinking water, knowledge of the potential toxicity of the photooxidation by-products is vital. The potential toxicity of UVA-, UVB-, UVC-irradiated, and UVC/H 2O 2-treated aquatic NOM in two spot samples from two Australian reservoirs was analysed in two spot samples using Vibrio fischeri in the Microtox TM test, African green monkey kidney cells (AS/NZS 4020:1999), and Daphnia carinata in an acute immobilisation test. Toxicity was not apparent for both the Microtox TM procedure and cytotoxicity analyses for the UVC-irradiated and UVC/H 2O 2-treated NOM samples, while UVA- and UVB-irradiated water samples were non-toxic to D. carinata. In contrast, acute toxicity was observed for UVC- and UVC/H 2O 2-treated water samples. The observed toxicity was attributed to photooxidative degradation of NOM-metal binding sites, which resulted in the release of bioavailable copper ions, as evidenced by higher concentrations of free copper ions in photooxidised water. As the total copper concentrations of the two raw water samples were well below the Australian Water Quality Guidelines for metals in domestic supplies, the release of copper from photooxidised NOM is unlikely to cause health concerns in these samples.

The role of HBV DNA quantitative PCR in monitoring the response to interferon treatment in chronic hepatitis B virus infection

Background/Aims: To investigate whether the measurement of HBV DNA by quantitative polymerase chain reaction (PCR) is helpful in monitoring response to interferon treatment in chronic hepatitis B virus infection, we have determined sequentially serum levels of HBV DNA during and up to 18 months after treatment, in 10 patients with a sustained response (all anti-HBe positive, five also HBsAg negative and anti-HBs positive) and, as controls, in 12 non-responders. Methods: Serum HBV DNA was measured by standard hybrisation assay (Genostics, Abbott) and by quantitative PCR (Amplicor HBV Monitor ™ test, Roche Diagnostic Systems). Results: A clear difference in HBV viral load between responders and non-responders was observed from the fourth week of treatment and was maintained throughout the study period. At the last follow up 16–26 (median 21) months after starting treatment, all the 10 responders were HBV DNA negative by hybridisation. By PCR, however, five (one anti-HBs and four anti-HBe positive) were still HBV DNA positive. In addition, one anti-HBs positive patient HBV DNA negative by PCR at last follow up, had fluctuating levels of HBV DNA by PCR during the observation period, only intermittently falling below the threshold of the assay. Conclusions: The measurement of HBV DNA by quantitative PCR provides early prediction of response to interferon, allowing prompt modification of treatment. With this technique, HBV DNA is detected in a high proportion of sustained responders, suggesting that HBV may never be completely eliminated by interferon treatment, even after anti-HBs seroconversion.

A new flash method for measuring the toxicity of solid and colored samples

A new approach far determining the toxicity of solid and highly coloured samples was developed. The measurement is based on the BioTox ™ test utilising bioluminescent Vibrio fischeri. The measurements were done with solid samples taken from an old industry area using a luminometer capable of monitoring light emission in a kinetic mode. In the method the signal from the sample is measured immediately after getting into contact with the sample and again after an incubation period of less than one minute, and therefore no correction factors are needed. The results are comparable to the results obtained with the standard Vibrio fischeri toxicity test (correlation coefficient r = 0,836) with a slightly reduced sensitivity but with many new features including ultra fast performance.

The significance of guinea worm infection in the immunological diagnosis of onchocerciasis and bancroftian filariasis

Infections with Dracunculus medinensis frequently occur in the same geographical area as infections with Onchocerca volvulus and Wuchereria bancrofti. This study analysed the significance of D. medinensis infections for the specificity and sensitivity of available tests for antibody-based diagnosis of onchocerciasis (using individual recombinant clones OV-10, OV-11 and OV-16, and the OV-7/OV-10/OV-16 tri-cocktail, in an enzyme-linked immunosorbent assay) and for circulating antigen-based diagnosis of bancroftian filariasis (using the TroBio ™ and the ICT ™ card tests). Some immunological cross-reactivity was observed with all tests. When using individual recombinant O. volvulus antigens, the highest assay indices were obtained for clone OV-10, and the lowest for clone OV-16. Testing the serum responses against the tri-cocktail of recombinant antigens did not notably improve the assay indices. Two of 40 serum samples from individuals with patent dracunculiasis gave a false positive response in the ICT ™ test and one of these was also positive in the TropBio ™ test. Possible implications of applying these diagnostic assays in areas endemic for dracunculiasis are discussed.

Evaluation of two tests based on the detection of histidine rich protein 2 for the diagnosis of imported Plasmodium falciparum malaria

The ParaSight ™-F dipstick test (Becton Dickinson, USA) and the ICT Malaria Pf ™ test (ICT, Australia) both detect histidine rich protein 2 (HRP-2), a water-soluble antigen expressed by Plasmodium falciparum trophozoites. The present study compared the diagnostic performance of both tests in persons returning to Belgium from countries endemic for malaria. During a period of 18 months both tests were performed on all patients returning from the tropics with a positive malaria blood film. Patients with fever without an obvious cause were used as controls. For the ParaSight ™-F test, considering P. falciparum trophozoites only, sensitivity was 95% and specificity 90%. Considering trophozoites of all species of Plasmodium, sensitivity was 71% and specificity 87%. Finally, considering patients with clinical malaria, the sensitivity of the test was 72% and specificity 87%. For the ICT Malaria Pf ™ test, sensitivity was 95% and specificity 89% for P. falciparum trophozoites only, 71% and 86% for trophozoites of all species, and 72% and 87% for clinical malaria. Both tests gave highly comparable results. However, antigen detection assays cannot replace conventional microscopy in diagnosing imported malaria. Thick blood film examination is more sensitive and more specific, it allows estimation of parasitaemia and distinction between parasite growth stages, and it covers all species. Moreover, with treated patients the use of antigen tests might lead to problems in determining the efficacy of therapy.

Comparison of the ParaSight ™-F test and the ICT Malaria Pf ™ test with the polymerase chain reaction for the diagnosis of Plasmodium falciparum malaria in travellers

Rapid and accurate methods are needed for the diagnosis of imported malaria. The ParaSight ™-F test and the ICT Malaria Pf ™ test are commercially available kits marketed for the diagnosis of Plasmodium falciparum malaria. Both tests are antigen-capture assays based on the detection of P. falciparum histidinerich protein 2 in peripheral blood. Using microscopy and a polymerase chain reaction (PCR)-based method as reference standards, we performed a ‘blinded’ comparison of these assays for the detection of P. falciparum infection in 200 febrile travellers returning from malaria-endemic areas. As determined by PCR and microscopy, 148 travellers had malaria and, of these patients, 54·7% ( 81 148 ) were infected with P. vivax only, 31·1% ( 46 148 ) with P. falciparum only, 9·5% ( 14 148 ) with P. ovale, 0·7% ( 1 148 ) with P.malariae, and 4·1% ( 6 148 ) had mixed infections. Compared to PCR, the ParaSight ™-F and ICT Malaria Pf ™ tests had initial sensitivities of 94% and 90% and specificities of 95% and 97%, respectively, for the detection of P. falciparum malaria. When discrepant samples were retested with day 0 and day 1 bloods, the sensitivities improved to 96% and 94%, respectively. The 2 remaining false negative results with the Para-Sight ™-F test and 2 of the 3 false negative results with the ICT Malaria Pf ™ test occurred in samples with <100 parasites/μL. The performance of these kits was not significantly different ( P = 0.75) and both are simple, rapid, and accurate tests for the detection of P. falciparum infection in the returned traveller.

Ratings of perceived exertion to determine intensity during outdoor running.

A paucity of data exists related to the usefulness of Ratings of Perceived Exertion (RPE) to set exercise intensity in non-laboratory settings. The purpose of this study was to determine if RPE could be used on an outdoor track to generate blood lactate and heart rate (HR) responses similar to those obtained on a treadmill (tm) run. Nine experienced runners (6 males, 3 females; VO2peak = 56.2 +/- 6.7 ml.kg-1.min-1) completed a horizontal, incremental tm test. HR, RPE, and lactate were measured for each stage. Subsequently, subjects ran for 30 min on an outdoor track at the RPE corresponding with 2.5 mM lactate during the tm run. Repeated measures ANOVA compared lactate and HR values at 2.5 mM lactate on the tm run and values obtained during the track run. Lactate during the track run was significantly higher (p < .05) than 2.5 mM throughout the 30 min (6.9 +/- 2.9, 6.3 +/- 2.9, and 5.8 +/- 3.0 mM at 10, 20, and 30 min, respectively). HR at 2.5 mM lactate during the tm run (173 +/- 6.1 bpm) was significantly lower (p < .05) than at min 10 and 20 of the track run (182.6 +/- 9.3 and 182.9 +/- 8.0 bpm, respectively) but not different from min 30 (181.3 +/- 10.6 bpm). In summary, it is difficult to generate specific physiological responses using RPE.

Atomic force microscopy, scanning electron microscopy and electrochemical characterization of Al alloys, conversion coatings, and primers used for aircraft

Characterization of the metal–coating interface is crucial to the understanding and prediction of the performance of corrosion protective coatings. To date, such characterization has been incomplete and performed on a scale of measurement that gives little microscopic-scale information. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) have the ability to provide such information. We present in this work the use of such methods to examine the interface between steel and marine coatings and to image the surface of untreated aircraft aluminum alloys. We have also imaged these aircraft alloys after chromate/phosphate pretreatment. AFM and SEM have also been used to investigate the changes in surface morphology, which accompany changes in the samples due to exposure. Electrochemical noise methods, electrochemical impedance spectroscopy measurements, and Prohesion TM testing were performed in parallel with the AFM/SEM measurements. The results, along with implications for aircraft coatings, are discussed.

Predicting the toxicity of complex mixtures using artificial neural networks

Industrial and municipal wastewaters constitute major sources of contamination of the aquatic compartment and represent a threat to aquatic life. Artificial neural networks based on three different learning paradigms were studied as a means of predicting acute toxicity to trout (5 days exposure to wastewaters) using input data from two simple microbiotests requiring only 5 or 15 min of incubation. These microbiotests were 1) the chemoluminescent peroxidase (Cl-Per) assay, which can detect radical scavengers and enzymeinhibiting substances, and 2) the luminescent bacteria toxicity test (Microtox TM), in which reduction of light emission by bacteria during exposure is taken as a measure of toxicity. The responses obtained with the trout bioassay, the Cl-Per and the Microtox TM test were analyzed through statistical correlation (Pearson product-moment correlation), unsupervised

LACTATE PRODUCTION IN RESPONSE TO MAXIMAL AND SUBMAXIMAL STAIRMASTER AND TREADMILL EXERCISE IN A SAMPLE OF MALE COLLEGE STUDENTS 933

The purpose of this study was to determine if muscular fatigue, as indicated by submaximal lactate production, was a factor limiting maximal performance on the StairMaster 4000PT (SM). Sixteen males, ages 20-28 years(mean 22.7±2.5) completed two maximal[SM-VO2max/treadmill(TM-VO2max))] and two submaximal (TM/SM) tests in four seperate visits to the laboratory. Maximal TM testing consisted of the Bruce protocol, while maximal SM testing involved manually progressing in intervals of 2 levels every 2 minutes. Submaximal testing consisted of a total of eight minutes of steady state exercise at 65% of TM-and SM-VO2max, respectively. The order of maximal and submaximal TM and SM testing was randomized. Prior to, and 1, 3, 5, and 7 minutes post maximal and submaximal testing on the TM and SM, fifty microliters of blood were collected via fingerprick of the index finger. Red blood cells were lysed and analyzed immediately with YSI 1500 Sport automated analyzer. Peak lactate was defined as the highest lactate measured (mmol·l-1) within minutes 1, 3, 5, and 7 post exercise. Statistical analysis (2 dependent t-tests with bonferroni correction factor 0.05/2=0.025) revealed: (1) TM-VO2max(3814.75±630.82 ml min-1) was significantly higher(t=7.5669,p=0.0001) compared to SM-VO2max (3230.38±543.74 ml min-1) and (2) submaximal SM-exercise resulted in a significantly greater (t=2.6547, p=0.0179) peak lactate (4.29±1.4 mmol·l-1) compared to submaximal TM-exercise(3.52±1.4mmol·l-1). Based on these results it was concluded that an increased lactate production found during submaximal exercise may be a factor limiting maximal performance on the SM.

Performance of the automated COBAS AMPLICOR ™ system for the detection of hepatitis C virus RNA

Background: The COBAS AMPLICOR ™ (CA) instrument for the amplification and detection steps of the AMPLICOR ™ molecular diagnostic assays has recently been introduced. The system contains a single thermal cycler with two independently controlled heating/cooling blocks, a pipettor, a magnetic particle washer, a photometer and an incubator. Objective: The performance of the CA instrument was evaluated in a routine diagnostic laboratory for the detection of hepatitis C virus (HCV) RNA. The new system was compared with the corresponding microwell plate assay (AMPLICOR HCV Test). Study design: Routine clinical sera (350) from hemodialysis patients and patients with chronic HCV infection and interferon therapy were studied. If discrepant results were obtained, both assays were repeated (specimen preparation, amplification and detection); in addition, the HCV copy number was determined with the AMPLICOR HCV MONITOR ™ Test. Results: There was a correlation between the CA HCV Test and the AMPLICOR HCV Test in 341 of 350 specimens (97%). After resolution of 9 discrepant results, the CA HCV Test gave a sensitivity of 97.8% and a specificity of 99.4%. The most common reason for discrepant results was a low HCV RNA copy number. Conclusion: The CA system was found to be a labor-saving, fast and reliable instrument for the amplification and detection steps of a RT-PCR molecular assay for detection of HCV RNA.

Problems and Recommendations in Using Algal Toxicity Testing to Evaluate Contaminated Sediments

Algae were used to evaluate the toxicity of elutriates prepared from contaminated sediments from several Great Lakes Areas of Concern. A single-species laboratory toxicity test using Selenastrum capricornutum was adapted from the U.S. Environmental Protection Agency's standard 96-h algal assay procedure. This standard method was converted to a 24-h photosynthetic test requiring only 25-mL sample volumes. Algal cells were exposed to elutriates supplemented with nutrients and radioactive inorganic carbon. Toxicity was measured as carbon uptake relative to controls. All elutriates were stimulatory relative to the negative control. Stimulation complicated interpretation of results and prevented calculation of effective concentrations causing a decrease in algal photosynthesis. Samples could be classified as toxic or non-toxic based upon dilution series response curves; however, classical dose:response curves were rarely observed. Algal results generally supported those derived from Daphnia and Microtox tm tests. Successful use of algal bioassays to evaluate the toxicity of sediment elutriates will require development of a standard media or sediment extract which could serve as an acceptable negative control or diluent. This could reduce the confounding effect of nutrient stimulation, which complicates the use of algal toxicity testing in sediment toxicity assessments.

Quantitative structure-toxicity relationships for 80 chlorinated compounds using quantum chemical descriptors

The acute toxicity to Photobacterium phosphoreum (Microtox TM test) of a set of 80 chlorinated compounds, containing aliphatics, benzenes, toluenes, phenols and anilines, was investigated using ‘Theoretical Linear Solvation Energy Relationship’ (TLSER) parameters. Quantative Structure-Activity Relationships (QSARs) were developed for chemical and toxicological subsets. Molecular volume (V mc) revealed to be the most important TLSER descriptor. For the complete data set and for the phenols the TLSER descriptors are superior to log P alone. In the case of the phenols this is related to electronic information being inherent in the electrostatic parameter q −, which is correlated to the pK a of the compounds. For the benzenes a quadratic term in V mc was very useful for the description of the toxicity. Many of the chlorinated aliphatics do not fit the narcosis I QSAR. Enhanced chemical reactivity due to the chlorine substitution may lead to activation or biodegradation of these compounds. The attempt to establish naccosis II QSARs for the polar narcotic chloroanilines and -phenols was unsuccessful. It seems that some chloroanilines interact directly with the bioluminescene system of P. phosphoreum. The authors emphasize that the concept of baseline narcosis implies that the ‘pure’ narcosis II mechanism decreases with increasing log P. The site of toxic action for narcosis II is therefore thought to be hydrophilic. Uncoupling of oxidative phosphorylation seems to play a minor role in the photobacterium than it does in fish. Reasons for this may be the ability of bacteria to crack and detoxify aromatic rings or the relative robustness of oxidative phosphorylation in bacteria.

Aquarunning and Gains in Cardiorespiratory Fitness

The primary purpose of this investigation was to determine the effects of deep-water run training on treadmill exercise (TM) and deep-water running (DWR) maximal oxygen consumptions (O2). Ten (8 F, 2 M) healthy sedentary subjects participated in randomly assigned TM and DWR O2max tests both pre- and posttraining. Treadmill O2max was assessed using either the Bruce protocol or a modification of it. Each deep-water running O2max test began at a warm-up cadence of 48 cycles · min−1, a cycle consisting of two steps. Thereafter intensity was increased by increasing leg cadence (66, 72, 76, etc.) every 3 min. Participants also underwent an 8-wk progressive, aerobic, interval deep-water running program. The sessions were conducted 3 days a week at 63 to 82% heart rate max for 16 to 36 min. Deep-water running produced gains in O2max of 10.6 for TM and 20.1% for DWR. Posttraining O2max values for TM and DWR were significantly greater than pretraining values. Thus deep-water run training improved the cardiorespiratory fitness of sedentary adults, produced greater gains in deep-water running O2max than in treadmill exercise O2max, and resulted in a training carryover effect to treadmill exercise.

Differentiation between fresh and thawed meat by an enzyme profile test

Exudates from fresh (stored at +4°C) and thawed pork and beef (frozen and stored below −20°C) was assayed by the rapid test kit API-ZYM TM to determine enzyme profiles. The test kit consists of 20 wells for different enzyme substrates. Of altogether 1040 results, only few reactions of the enzymes differed in their intensity between frozen and thawed pork or beef. Fresh pork showed a more intensive β-galactosidase and N-acetyl-β-glucosaminidase reaction while with fresh beef a more intensive reaction could only be detected for N-acetyl-β-glucosaminidase. Only N-acetyl-β-glucosaminidase showed significant differences between fresh and frozen meat in both species (α = 0·01). Considering the indistinct results of the test kit differentiation between frozen and thawed meat, the API-ZYM TM test kit is considered not suitable for distinguishing frozen from thawed pork or beef.

Specificity of Cholera Screen ™ test during an epidemic of cholera-like disease due to Vibrio cholerae O139 synonym Bengal

Specificity of Cholera Screen ™ test during an epidemic of cholera-like disease due to Vibrio cholerae O139 synonym Bengal

The validation of hydrocodes for orbital debris impact simulation

Orbital debris pose a danger for spacecraft in orbit. Protection against this threat is obtained by shielding. One or more shields placed at some distance from the structure to be protected can minimize the damage inflicted by projectiles at high velocity. The range of velocity between 0 and 8 km/s is well covered by tests. Unfortunately, the average velocity of debris in low earth orbit is above 10 km/s with a maximum velocity around 15 km/s. The methodology presented in this paper aims to validate the numerical approach. It will predict and extrapolate the behavior of multishock shields in the velocity range between 8 and 15km/s. The formation and propagation of the debris cloud, after perforation of the shields and the generation of damage in the backwall, are key factors. These phenomena are examined, discussed and illustrated with correlation between numerical simulation with EFHYD TM analytical formulae and test results.

Microtox TM response to volatile organic pollutants — implementation of the test in investigating accidental or deliberate watersupply pollution

The toxic effects of 7 mixtures of volatile organic pollutants vocols (Vs) (Supelco Cat. 87, Nos:4/ 8775, 8777, 8779, 8786, 8797, 8799, 8802), expressed as EC 20, 5 min EC 20, have been investigated on Photobacterium phosphoreum using the Microtox TM test (MTX). The results derived were compared with those from a gas chromatography ‘fingerprint screening test’. The individually measured EC 20s (for each V), correlated well with those calculated from the EC 20 of a solution containing all the Vs (correlation coefficient, r = 0.99997). This is indicative of a simple similar action and a clear additive toxic effect. The present work shows the capability of MTX in investigating combined toxic effects as well as the importance of MTX as a tool of a quick ‘battery’ response system in handling accidental or deliberate watersupply pollution.

Development and evaluation of a rapid, simple, sensitive, monoclonal antibody-based co-agglutination test for direct detection of Vibrio cholerae 01

Cholera epidemics caused by Vibrio cholerae 01 continue to represent a major public health concern in many developing countries. A rapid and simple test kit for the detection of V. cholerae 01 has been developed. The kit, CholeraScreen TM is a monoclonal antibody-based, co-agglutination test and is used directly with stool specimens. It does not include culturing the specimen and is performed without the need for sophisticated laboratory equipment. Specificity of the test was demonstrated, using 118 reference cultures, to which cross-reactions were not observed. Preliminary results of field trials carried out in Guatemala and Bangladesh demonstrated that the test is equally sensitive as conventional culture methods in detecting V. cholerae and, in many cases, more sensitive. The CholeraScreen TM test is simple, specific, and does not require culturing procedures, making it suitable for direct detection of cells of V. cholerae in clinical specimens, even in the field. Also, the test requires less than five minutes to complete.