765,312 research outputs found
Gastrointestinal parasites of feral cats from Christmas Island
Objective To investigate the gastrointestinal parasites present in feral cats on Christmas Island, with particular interest in the protozoan parasite Toxoplasma gondii. Procedure Faecal and serum samples were collected from 28 and 25 cats respectively that were trapped as part of an ongoing eradication program being run on Christmas Island by the Department of Environment and Conservation. Faecal samples were screened microscopically for helminth and protozoan parasites. Serum samples were screened for antibodies to T gondii using a commercial indirect immunofluorescence assay (IFA) and a latex agglutination test (LAT). Results The most common helminth parasites detected were Toxocara cati (present in 15 of 28 faecal samples), Strongyloides sp (13/28), Aelurostrongylus abstrusus, (7/28), an unidentified capillarid (6/28) and Ancylostoma sp (4/28). Based on serology, T gondii was the most common parasite detected (protozoan or otherwise) with antibodies detected in 24 serum samples by IFA and 23 serum samples by LAT. Conclusion Cats on Christmas Island harbour many of the helminth and protozoan parasites reported from feral cats elsewhere in Australia. The high seroprevalence of T gondii in these cats indicates a high level of exposure to the parasite in this environment
Evaluation of the stability of human erythropoietin in samples for radioimmunoassay
Radioimmunoassays for erythropoietin are limited so far to a few specialized laboratories and this requires transport and storage of samples. We therefore tested the stability of immunoreactive erythropoietin in serum and plasma samples obtained from a uremic and a nonuremic anemic patient. No significant change in the concentration of immunoreactive erythropoietin was found in either serum or plasma samples for up to 14 days of storage. This type of stability was observed no matter whether the samples were stored at room temperature, 4 degrees C, or -20 degrees C. There was no difference between the estimates of erythropoietin in serum and heparinized plasma. Validity of the radioimmunoassay used in this study was demonstrated by parallelism of dilution curves of test specimens and the 2nd International Reference Preparation for erythropoietin and by a close correlation between the immunoreactivity and the bioactivity of the hormone, as assessed in the same samples by the exhypoxic polycythemic mouse bioassay. In conclusion the data obtained clearly indicate that the necessity of storage and transport of clinical samples does not limit the practicability of the radioimmunoassay for erythropoietin
Optimizing Measurement of Vascular Endothelial Growth Factor in Small Blood Samples of Premature Infants
To establish a method that allows for the reliable assessment of vascular endothelial growth factor (VEGF-A) concentrations in very small blood samples of preterm infants. Systemic VEGF measurements are important in view of the most appropriate Anti-VEGF drug to be used for the treatment of acute retinopathy of prematurity (ROP). Cord blood samples from preterm (n = 6) infants, blood samples from preterm infants with treatment requiring ROP (n = 12), and blood samples from healthy adults (n = 10) were collected. Serum, citrate plasma, and serum from recalcified citrate blood were obtained. Levels of VEGF-A and platelet factor-4 (PF-4) were quantified by ELISA or AlphaLISA immunoassay. VEGF-A levels could be detected by both assays, with the AlphaLISA generating slightly lower levels in healthy adults, but not in cord blood of preterm infants. In plasma samples, VEGF levels ranged from non detectable to 181 pg/ml. PF-4 concentrations were between 0.16-3.88 microg/ml. Values of VEGF-A and PF-4 in serum and recalcified serum were significantly higher compared to plasma through the release of these cytokines after platelet activation. In plasma samples of infants with ROP, VEGF-A could always be detected and its values ranged from 19.50 to 245.91 pg/ml and PF-4 concentrations were between 0.1 and 3.3 microg/ml. Using the AlphaLISA kit, we were able to detect VEGF in small sample volumes (5 microl plasma or serum/well) in premature infants with treatment requiring ROP and to monitor platelet activation by PF-4 detection. Minimal blood probe volumes reduce phlebotomy losses avoiding the risk of iatrogenic anemia, thus allowing close monitoring of the cytokine levels in these very fragile infants
Immunoreactive human chorionic gonadotropin and its free ß-subunit in serum and ascites of patients with malignant tumors
Human chorionic gonadotropin (hCG) is a clinically relevant marker of trophoblastic and nontrophoblastic malignancies. In the present studies, in addition to determining serum hCG, we investigated the presence and properties of hCG immunoreactivity in ascites of patients with nontrophoblastic malignant tumors and, for comparison, in ascites caused by cirrhotic liver disease. Total hCG immunoreactivity [hCG (+hCG-ß)] was found to be elevated above the reference value (>5 IU/liter) in the serum of 2 of 20 patients with cirrhosis and 11 of 20 patients with malignant tumors. For comparison, in ascites, hCG (+hCG-ß) concentrations were frequently higher than in the corresponding serum samples and exceeded 10 IU/liter in 0 of 20 cirrhotic samples and in 16 of 20 malignant samples.
In order to elucidate the nature of the hCG immunoreactive material, all samples were then assessed by immunoradiometric assays specific for the intact hCG molecule (holo-hCG) and the free hCG-ß subunit, respectively. In the holo-hCG assay, elevated values were detected in 0 of 20 (0 of 20) cirrhotic ascites (serum) samples and 0 of 20 (1 of 20) malignant ascites (serum) samples. In the free hCG-ß assay, on the other hand, no positive results were obtained in the ascites or serum of 20 patients with liver cirrhosis; however, 8 of 20 serum samples and 16 of 20 ascites samples derived from tumor patients were positive. In accord with the immunological data, gel chromatographical studies of malignant ascites revealed the abundance of free hCG-ß subunit rather than that of holo-hCG. In contrast to malignancy-related ascites, in ascites of patients receiving hCG injections for treatment of infertility, holo-hCG was more abundant than free hCG-ß immunoreactivity. Incubation experiments of purified holo-hCG in ascites for 24 h at -20, 20, or 37°C showed no substantial dissociation of the hCG molecule and release of free hCG-ß immunoreactivity, thus arguing against production of free hCG-ß by degradation of holo-hCG and in favor of its tumor-related secretion.
In conclusion, hCG-ß immunoreactivity is frequently elevated in malignancy-related ascites and appears to be related to the presence of free ß subunit of hCG rather than that of the intact hCG molecule. Interestingly, hCG-ß determination in ascites proved to be clearly superior to serum measurement in discriminating between tumor and cirrhosis. Thus, hCG-ß might be a useful marker of malignancy-related ascites and should be prospectively assessed for possible clinical use in comparison with other well-established parameters, such as cytology and protein determination. For this purpose, according to our results, only assays that exhibit a high sensitivity for free hCG-ß subunit appear to be suitable
Free serum cortisol: quantification applying equilibrium dialysis or ultrafiltration and an automated immunoassay system
Background: Quantification of bioactive, free serum cortisol concentrations can characterize adrenocortical function more appropriately compared to total serum cortisol measurement. Ultrafiltration or equilibrium dialysis of serum samples allow direct measurement of free serum cortisol concentrations but respective methods have poorly been validated so far. The aim of our study was to investigate the analytical performance of free serum cortisol measurement employing equilibrium dialysis and ultrafiltration. Methods: Two commercially available ultrafiltration devices and self-assembled dialysis cells, respectively, were studied. Cortisol was quantified in filtrate or dialysate using an automated immunoassay system. Using two serum pools, the inter-assay coefficient of variation was determined for the three methods and a method comparison was performed. Results: Inter-assay coefficients of variation (n=10) between 3.2% and 14.8% were observed in the imprecision study. Method comparison demonstrated close agreement between free serum cortisol results obtained by ultrafiltration and equilibrium dialysis, respectively (equilibrium dialysis = 1.2x ultrafiltration+3.9 nmol/L; r=0.99; n=35). Conclusions: Direct quantification of free serum cortisol after equilibrium dialysis or ultrafiltration of the samples offers acceptable reproducibility and results in close agreement can be obtained. Both methods can potentially be introduced into a routine laboratory setting
Epidemiology and the agreement rate of serological tests in human brucellosis in North East of Iran
Background: Brucellosis still remains a major health problem with different symptoms and various diagnostic methods. Diagnostic methods of brucellosis are usually based on detecting specific antibodies in the patient’s serum. Nowadays, many serological tests are applied for the diagnosis of human brucellosis. Most routine tests are serum agglutination tests based on Wright and 2-Mercaptoethanol (2-ME). Objectives: The aim of this study (cross sectional study) was to evaluate the prevalence of brucellosis and assess the degree of agreement among serum samples of suspected brucellosis serological tests routinely performed in Mashhad, Iran. Patients and Methods: This study was conducted in Mashhad from August 2011 to September 2012. Sera (2 - 3 mL) were collected from 83 cases suspected of brucellosis among 594 patients. Ten serum samples were collected from healthy subjects as control sera. Rose Bengal test for initial screening and Wright and 2 ME as standard tests were conducted to determine antibody titers. Thereafter, IgG and IgM levels were determined by the Enzyme Linked Immunosorbent Assay (ELISA) method. Results: Among 83 serum samples, Rose Bengal test was able to identify 20 (12%) positive specimens; the standard tube agglutination test was able to detect 30 (18%) positive samples, and the ELISA IgG and ELISA IgM were able to trace 42 (21%) and 13 (6.5%) positive samples, respectively. Ten control samples had negative results for the ELISA method. The results were calculated by the Kappa formula. The highest level of agreement was among 1 = KRB-SAT tests and the lowest level of agreement was among tests K ELISA IgM-IgG = 0.30. Conclusions: According to the results, brucellosis has remained endemic in this region. Most cases were detected by ELISA IgG. The highest kappa agreements were between tests KRB-SAT, KRB-IgG and KSAT-IgG, while the lowest levels of agreement were between tests SAT-IgM and ELISA IgM-IgG. Considering that ELISA IgM results are covered by SAT and ELISA IgG test results, applications of this test do not seem necessary. © 2015, Infectious Diseases and Tropical Medicine Research Center
A Large Outbreak of Hepatitis E Among a Displaced Population in Darfur, Sudan, 2004: The Role of Water Treatment Methods.
BACKGROUND: The conflict in Darfur, Sudan, was responsible for the displacement of 1.8 million civilians. We investigated a large outbreak of hepatitis E virus (HEV) infection in Mornay camp (78,800 inhabitants) in western Darfur. METHODS: To describe the outbreak, we used clinical and demographic information from cases recorded at the camp between 26 July and 31 December 2004. We conducted a case-cohort study and a retrospective cohort study to identify risk factors for clinical and asymptomatic hepatitis E, respectively. We collected stool and serum samples from animals and performed a bacteriological analysis of water samples. Human samples were tested for immunoglobulin G and immunoglobulin M antibody to HEV (for serum samples) and for amplification of the HEV genome (for serum and stool samples). RESULTS: In 6 months, 2621 hepatitis E cases were recorded (attack rate, 3.3%), with a case-fatality rate of 1.7% (45 deaths, 19 of which involved were pregnant women). Risk factors for clinical HEV infection included age of 15-45 years (odds ratio, 2.13; 95% confidence interval, 1.02-4.46) and drinking chlorinated surface water (odds ratio, 2.49; 95% confidence interval, 1.22-5.08). Both factors were also suggestive of increased risk for asymptomatic HEV infection, although this was not found to be statistically significant. HEV RNA was positively identified in serum samples obtained from 2 donkeys. No bacteria were identified from any sample of chlorinated water tested. CONCLUSIONS: Current recommendations to ensure a safe water supply may have been insufficient to inactivate HEV and control this epidemic. This research highlights the need to evaluate current water treatment methods and to identify alternative solutions adapted to complex emergencies
State of Harmonization of 24 Serum Albumin Measurement Procedures and Implications for Medical Decisions
BACKGROUND: Measurements of serum and plasma albumin are widely used in medicine, including as indicators of quality of patient care in renal dialysis centers. METHODS: Pools were prepared from residual patient serum (n = 50) and heparin plasma (n = 48) from patients without renal disease, and serum from patients with kidney failure before hemodialysis (n = 53). Albumin was measured in all samples and in ERM-DA470k/IFCC reference material (RM) by 3 immunochemical, 9 bromcresol green (BCG), and 12 bromcresol purple (BCP) methods. RESULTS: Two of 3 immunochemical procedures, 5 of 9 BCG, and 10 of 12 BCP methods recovered the RM value within its uncertainty. One immunochemical and 3 BCG methods were biased vs the RM value. Random error components were small for all measurement procedures. The Tina-quant immunochemical method was chosen as the reference measurement procedure based on recovery and results of error analyses. Mean biases for BCG vs Tina-quant were 1.5% to 13.9% and were larger at lower albumin concentrations. BCP methods\u27 mean biases were -5.4% to 1.2% irrespective of albumin concentration. Biases for plasma samples were generally higher than for serum samples for all method types. For most measurement procedures, biases were lower for serum from patients on hemodialysis vs patients without kidney disease. CONCLUSIONS: Significant differences among immunochemical, BCG, and BCP methods compromise interpretation of serum. albumin results. Guidelines and calculations for clinical management of kidney and other diseases must consider the method used for albumin measurement until harmonization can be achieved
Evaluation of Canine Pancreas-Specific Lipase Activity, Lipase Activity, and Trypsin-Like Immunoreactivity in an Experimental Model of Acute Kidney Injury in Dogs.
BackgroundDiagnosis of pancreatitis in dogs is complicated by extrapancreatic disorders that can alter the results of laboratory tests. Extrapancreatic disorders can also affect the diagnosis of exocrine pancreatic insufficiency (EPI). The effects of acute kidney injury (AKI) on pancreas-specific lipase activity (Spec cPL(®) Test), serum lipase activity and trypsin-like immunoreactivity (TLI) in dogs have not been evaluated.Hypothesis/objectivesSerum Spec cPL, lipase activity, and TLI concentrations will increase secondary to decreased kidney function.AnimalsFive purpose-bred dogs.MethodsExperimental prospective study. Gentamicin was used to induce AKI in 5 purpose-bred dogs. Serum samples were collected for measurement of creatinine, Spec cPL, lipase activity and TLI over 60 days, during both induction of, and recovery from, AKI.ResultsAll dogs developed and recovered from AKI. Six of 52 (12%) serum Spec cPL concentrations were increased (2 in the equivocal zone and 4 consistent with pancreatitis) in 2 of 5 (40%) dogs. Two of 51 (4%) serum lipase activity values were increased in 2 of 5 dogs. Serum TLI was increased above the reference range in 17 of 50 (34%) samples in 3 of 5 dogs. For all biomarkers, there was no consistent correlation with increases in serum creatinine concentration.Conclusions and clinical importanceDecreased renal excretion during experimental AKI did not cause consistent and correlated increases in serum Spec cPL, lipase activity, or TLI in this cohort of dogs
Zinc and Copper Levels in Patients with Primary Hypertension and Normotension
One of the causes of primary hypertension is an exposure to free radicals. The formation of free radicals in the body can be prevented by taking antioxidants. Zinc and copper are cofactors of endogenous antioxidant enzyme superoxide dismutase. This study aimed to analyze the differences of zinc and copper levels in primary hypertensive and normotensive patients. This was an analytical observational study with cross sectional design and simple random sampling method. Subjects were patients aged 40-70 years at Haji General Hospital consisting of 15 primary hypertensive patients and 15 normotensive individuals (comparison group). Data was collected through interviews and laboratory test of blood samples. Zinc and Copper serum concentrations were measured by AAS. Data were analyzed by chi-square and independent samples t-test. The results showed that the mean levels of zinc and copper in primary hypertensive patients was lower than normotensive. However, statistically there was no difference in zinc serum levels (p=0.852) in the two groups, and there was a significant difference in copper serum levels (p=0.032). It can be concluded that there were differences in copper serum levels between the two groups but not with the levels of zinc
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