Fluorescence Polarization Immunoassay Research Articles

A highly specific and sensitive fluorescence polarization immunoassay for the rapid detection of triazophos residue in agricultural products

A highly specific and sensitive fluorescence polarization immunoassay for the rapid detection of triazophos.

Fit-for-purpose chromatographic method for the determination of amikacin in human plasma for the dosage control of patients

In this paper, a simple, rapid and sensitive method based on liquid chromatography with fluorimetric detection (HPLC-FLD) for the determination of amikacin (AMK) in human plasma is developed. Determination is performed by pre-column derivatization of AMK with ortho-phtalaldehyde (OPA) in presence of N-acetyl-L-cysteine (NAC) at pH 9.5 for 5min at 80°C. In our knowledge, this is the first time that NAC has been used in AMK derivatization. Derivatization conditions (pH, AMK/OPA/NAC molar ratios, temperature and reaction time) are optimized to obtain a single and stable, at room temperature, derivative. Separation of the derivative is achieved on a reversed phase LC column (Kromasil C18, 5μm, 150×4.6 i.d. mm) with a mobile phase of 0.05M phosphate buffer:acetonitrile (80:20, v/v) pumped at flow rate of 1.0mL/min. Detection is performed using 337 and 439nm for excitation and emission wavelengths, respectively. The method is fitted for the purpose of being a competitive alternative to the currently used method in many hospitals for AMK dosage control: fluorescence polarization immunoassay (FPIA). The method exhibits linearity in the 0.17–10µgmL−1 concentration range with a squared correlation coefficient higher than 0.995. Trueness and intermediate precision are estimated using spiked drug free plasma samples, which fulfill current UNE-EN ISO15189:2007 accreditation schemes. Finally, for the first time, statistical comparison against the FPIA method is demonstrated using plasma samples from 31 patients under treatment with AMK.

A universal multi-wavelength fluorescence polarization immunoassay for multiplexed detection of mycotoxins in maize

Multi-analyte immunoassays have attracted increasing attention due to their short assay times, low sample consumption, and reduced detection costs per assay. In this work, we describe a homologous and high-throughput multi-wavelength fluorescence polarization immunoassay (MWFPIA) for the multiplexed detection of mycotoxins. Three typical Fusarium mycotoxins, deoxynivalenol (DON), T-2 toxin and fumonisin B1 (FB1), were labeled with different dyes. Tracers and specific monoclonal antibodies (mAbs) were employed in the MWFPIA to simultaneously detect the three mycotoxins. Under optimal conditions, the limits of detection using MWFPIA were 242.0μgkg−1 for DON, 17.8μgkg−1 for T-2 toxin and 331.5μg kg−1 for FB1, providing sufficient sensitivity to meet the action levels of these three contaminants in maize as set by the European Union. The use of a methanol/water (2:3, v/v) mixture for sample pretreatment allowed recoveries ranging from 76.5–106.3%, with coefficients of variation less than 21.7%. The total time of analysis, including sample preparation, was less than 30min. Twenty naturally contaminated maize samples were tested using MWFPIA and HPLC–MS/MS, with correlation coefficients (R2) of 0.97 for DON and 0.99 for FB1. By changing the targets of interest, homologous MWFPIA, a method with high sensitivity, a simple procedure and a short analysis time, can easily be extended to other chemical contaminants. Thus, MWFPIA represents a versatile strategy for food safety analysis.

Rhubarb decreased the systemic exposure of cyclosporine, a probe substrate of P-glycoprotein and CYP 3A

1. Rhubarb, rhizome of Rheum palmatum L. (RP), is an important herb in clinical Chinese medicine.2. Cyclosporine (CSP) is an immunosuppressant with narrow therapeutic window. The oral bioavailability of CSP was associated with P-glycoprotein (P-gp) and CYP 3A4. CSP was used as a probe substrate to investigate the in vivo modulation effects of RP on P-gp and CYP 3A.3. Rats were orally administered 2.5 mg/kg of CSP with and without 0.25 and 1.0 g/kg of RP. The blood CSP concentration was determined by a specific monoclonal fluorescence polarization immunoassay.4. Both dosages of RP significantly decreased the Cmax and AUC0–t of CSP in rats. Mechanism studies indicated that RP activated the functions of P-gp and CYP 3A.5. RP ingestion reduced the systemic exposure of CSP through activating P-gp and CYP 3A.

Comparison of two tourniquet application times for regional intravenous limb perfusions with amikacin in sedated or anesthetized horses

Regional limb perfusion (RLP) in horses has proven to be a simple and effective technique for the treatment of synovial and musculoskeletal infections in the distal portion of the limbs. The ideal tourniquet time needed to achieve therapeutic synovial concentrations remains unknown. The pharmacokinetic effects of general anesthesia (GA) versus standing sedation (SS) RLP on synovial amikacin concentrations are not completely understood. This study investigated the pharmacokinetic effects of RLP under general anesthesia (GA) versus standing sedation (SS) on synovial amikacin concentration following 20 or 30 min tourniquet time. Using 1 g of amikacin RLP was performed in two groups of six horses (GA and SS). A pneumatic tourniquet was applied proximal to the carpus and maintained for 20 or 30 min. Two weeks later, the opposite treatment (20 or 30 min) was randomly performed in the opposite limb of horses in each group (GA and SS).Synovial fluid samples were collected from the metacarpophalangeal (MCP) and radiocarpal (RC) joints. Amikacin was quantified by a fluorescence polarization immunoassay. Regardless of the group, no significant difference in the synovial amikacin concentrations was noted between 20 and 30 min RLP. Mean synovial concentrations of amikacin in the standing sedated horses were significantly higher in the MCP joint at 30 min (P = 0.003) compared to horses under general anesthesia. No significant difference was noted for the RC joint.

Sensitive immunochemical approaches for quantitative (FPIA) and qualitative (lateral flow tests) determination of gentamicin in milk

Three kinds of immunoassays for the determination of gentamicin in milk samples were developed and validated. First, a fast and easily-performed fluorescence polarization immunoassay was used for characterization of the employed polyclonal antibody. The calculated Kaff were (1.9±0.4)×109М−1 and (6.0±0.2)×106М−1 for the high- and low-affinity fractions respectively. The assay was characterized with a good sensitivity, the limit of detection being 5μgkg−1. Two different kinds of detection labels, i.e. colloidal gold (CG) and quantum dots (QDs), were evaluated for use in lateral-flow format with respect to rapid visual on-site testing. The cut-off levels for both qualitative formats were selected based on the maximum level for gentamicin in milk established by the European Commission, 100μgkg−1, resulting in a 10μgkg−1 cut-off considering sample dilution. The intra-laboratory validation was performed with sterilized milk samples artificially spiked with gentamicin at concentrations less than, equal to, and greater than the cut-off level. It was shown that milk products could be analyzed without any sample preparation, except for dilution with the buffer solution. The rates of false-positive and false-negative results were below 5% for both labels. The different developed immunoassays were tested towards gentamicin determination in artificially-spiked and naturally contaminated milk samples.

Head to head evaluation of the analytical performance of two commercial methotrexate immunoassays and comparison with liquid chromatography-mass spectrometry and the former fluorescence polarization immunoassay

Monitoring of plasma drug levels is mandatory in patients receiving high-dose methotrexate. This study evaluated the analytical performance of the novel Architect and the established ARK™ methotrexate immunoassay (running on the Roche Cobas© c502 analyzer) in comparison with liquid chromatography-mass spectrometry (LC-MS) and the TDx/TDxFLx Methotrexate II assay. Imprecision and linearity were verified for the Architect and ARK assay according to CLSI EP15-A3 and EP6-A guidelines, respectively. The reported limit of quantitation (0.04 μmol/L) was tested for both assays according to the CLSI EP17-A2 guideline. Correlation and agreement between the different assays were evaluated using residual plasma samples (n=153). Total imprecision was <6.3% and <9.5% for the Architect and ARK assay, respectively. The claimed linearity and limit of quantitation were confirmed for the Architect assay. For the ARK assay, imprecision at the limit of quantitation was <18% with a positive bias resulting in a high total error up to 58%, and hence the linearity could not be confirmed. Both assays showed strong correlations with the TDX assay and LC-MS but a positive bias of 12.2% and 20.5% in comparison to LC-MS for the Architect and ARK assay, respectively. For the ARK assay this bias increased dramatically for samples with concentrations towards the limit of quantitation. The Architect assay is suitable for monitoring plasma methotrexate, but the ARK assay showed unsatisfactory performance in the analysis of low concentrated samples. Unlike the TDX assay, both assays require manual dilution of samples at higher concentrations, which delays sample processing in clinical routine.

Design of a sensitive fluorescent polarization immunoassay for rapid screening of milk for cephalexin.

In this paper we describe the development of a sensitive, fast, and easily performed fluorescence polarization immunoassay for determination of cephalexin in milk. The experimental work was performed to increase sensitivity and specificity. Therefore, the structures of the tracers were varied by synthesis of both cephalexin (CEX) and cephalotin (CET) conjugates with a variety of fluorescent labels. Two rabbit antisera containing antibodies against cephalexin and cephalotin were tested in homologous and heterologous combinations with the tracers. For every working antibody-tracer combination, the analytical conditions and cross-reactivity for structural analogues-cephalosporins and other antibiotics that could also be present in milk-were determined. It was found that the highest sensitivity was achieved by use of the homologous pair CET-EDF-anti-CET antibody (limit of detection (LOD) 0.4 μg kg(-1) for standard solutions prepared in buffer), but this combination was not appropriate because of high cross-reactivity with CET. For subsequent experiments, therefore, CEX- EDF-anti-CEX antibody were chosen (LOD 0.8 μg kg(-1) for standard solutions prepared in buffer). Part of this manuscript is devoted to the variation of precipitation agents for pretreatment of milk before analysis; milk is an extremely complicated matrix. The optimum protein precipitation agent was methanol. This technique for cephalexin determination was characterized by a limit of detection of 1 μg kg(-1). The method was validated by using naturally contaminated and spiked milk samples. The results obtained corresponded very well with those obtained by HPLC, which was used as confirmation method.

Fluorescence polarization measurement system using a liquid crystal layer and an image sensor.

The detection system which enables simultaneous fluorescence polarization (FP) measurement of multiple samples was proposed and proven by a proof-of-concept experiment on the viscosity dependence of FP of fluorescein sample in water-ethylene glycol solution and another experiment on the FP immunoassay of prostaglandin E2 sample. The measurement principle of FP is based on the synchronization between the orientation of the liquid crystal molecules and the sampling frequency of a CCD. This report is the first description of the simultaneous FP measurement of multiple samples. This system has a great potential for equipment miniaturization and price reduction as well as providing simultaneous FP measurement of multiple samples.

Quantification of Diethyl Phthalate by a Rapid and Homogenous Fluorescence Polarization Immunoassay

A rapid and homogenous fluorescence polarization immunoassay (FPIA) for diethyl phthalate is reported. Two haptens and three immunogens for diethyl phthalate were synthesized to generate polyclonal antibodies and fluorescein isothiocyanate labeled diethyl phthalate was prepared as the tracer. The antibodies, methanol concentration, and incubation time were optimized. The cross-reactivities of the optimized antibodies to other phthalate esters were characterized. The antibody shows excellent sensitivity with a limit of detection of 6.0 ng mL−1 and a half-inhibition concentration of diethyl phthalate of 40.4 ng mL−1. The immunoassay had a linear dynamic range from 10 to 200 ng mL−1. The mean coefficient of variation was lower than 11.3% for intra-assay and lower than 14.6% for inter-assay measurements. The limit of detection was 1.46 ng mL−1 in bottled drinking water, 0.34 µg mL−1 in juice, and 50.0 µg g−1 in pharmaceutical capsules. The recovery was from 85.9 to 114.9%, and the coefficients of variation were 4.3 to 17.0%. The developed immunoassay provided good sensitivity, specificity, accuracy, and may serve as an alternative for diethyl phthalate determination for field screening of food, pharmaceuticals, and environmental materials.

Association of maternal homocysteine and vitamins status with the risk of neural tube defects in Tunisia: A case-control study.

This study was conducted to determine whether low folate and vitamin B12 levels, as well as high homocysteine levels in pregnant women are associated with neural tube defects (NTDs) in Tunisia. A total of 75 NTDs pregnancies and 75 matched controls were included in the study. Their vitamin B12, folate, and red blood cell folate concentrations were measured using a radio-immunoassay kit and total homocysteine concentrations were determined using a fluorescent polarization immunoassay. Vitamin B12 and folate concentrations were lower in NTD-affected pregnant women than in controls (respectively, p = 0.009 and p < 0.001). Total homocysteine concentration was significantly higher in the NTDs group than in controls (p = 0.008). In the case group, the folate levels were positively related with vitamin B12 levels (r = 0.54; p < 0.001) and negatively correlated with total homocysteine levels (r = -0.19; p = 0.04). Besides, red blood cell folate levels were positively correlated with folate levels (r = 0.24; p = 0.02) and negatively correlated with total homocysteine levels (r = -0.37; p = 0.001). Lower concentrations of folate and vitamin B12 are related to the increased risk of NTDs. Both folate and vitamin B12 intake insufficiency could contribute to the increased risk of NTDs. A dietary supplement, combining folate and vitamin B12, might be an effective measure to decrease the NTDs incidence in Tunisia.

P3‐099: The change of serum homocysteine (Hcy) and high sensitivity c‐reactive protein (hs‐CRP) in tibetan nationality patients with Alzheimer's disease in different high‐altitude areas

Tibetan nationality population was accounted for 48.4% in Qinghai-Tibet Plateau, which areas faced to many environmental stresses, including chronic hypoxia, high altitude and relative isolation from the outside world. To study Tibetan nationality patients of Alzheimer's disease(AD) at various high altitude areas, serum Homocysteine (Hcy) and high-sensitivity C-reactive protein (hs-CRP) was evaluated. We collected four groups of high altitude areas in Qinghai-Tibet Plateau: Xining region (middle altitude at 2,260m), Yushu region (high altitude at 3,800m above sea level): 25 Tibetan nationality patients of mild-to-moderate AD at middle altitude and healthy Tibetan nationality elderly from the same altitude;31 Tibetan nationality patients of mild-to-moderate AD at high altitude and healthy Tibetan nationality elderly from the same altitude. 112 people (50-87 years old) were the half women and men. The patients were diagnosed according to NINCDS /ADRDA and DSM-IV criteria as having the probable AD. Every people was investigated with a questionnaire, which including the basic information (age, race, cognize status, daily life and social economic condition and social intercourse, smoking, drinking, folic absorb, cholesterol and family history). Serum Hcy, VitaminB12 and folic acid were measured by Fluorescence Polarization Immunoassay. Serum hs-CRP, triglyceride (TG) and low density lipoprotein cholesterol (LDL-c) were measured by TOSHIBA TBA-2000FR analyzer. Compared to controls at same high altitude, Hcy and hs-CRP were significantly increased in Tibetan nationality patients with AD (P<0.01). In AD groups, HCY、TG、LDL-c and hs-CRP increased with altitude. On contrast, folic acid between AD and control group were decreased at high altitude compared those of middle altitude. Vitamin B12had no change in the all of four groups. Multiple logistic regression analysis showed the association between the nation, altitude, dietary habit, blood grease, folacins, Hcy, hs-CRP and patients with AD at Plateau. Through study of correlation of Tibetan patients with AD at various high altitudes and Hcy, hs-CRP, folic acid, TG and LDL-C, we found that Tibetan AD patients had dietary habits with more carnivorous dietary and high fat intake, less green vegetable and fruit intake to result in inadequate intake of folic acid. Therefore, Inflammation and vascular risk factors may contribute to the development of Tibetan nationality AD in hypoxia environment.

Homocysteine – relation to hypertension, age and smoking in patients with newly diagnosed essential hypertension

Introduction. An elevated circulating concentration of homocysteine is associated with an increased risk of coronary, cerebral, and peripheral vascular disease. The purpose of this study was to determine the concentrations of homocysteine in the patients with newly diagnosed essential hypertension and healthy subjects and to analyze the correlation between homocysteine level and the other parameters (age, blood pressure, smoking).Material and methods. The study group consisted of 18 patients with essential hypertension, 4 women and 14 men (mean age 43 ± 16 years) and 15 healthy volunteers, 8 women and 7 men (mean age 47 ± 10 years). Serum homocysteine was analyzed by FPIA method (Fluorescence Polarization Immunoassay).Results. The patients with essential hypertension had significantly higher homocysteine concentration compared to control group. No correlation was observed between homocysteine levels and age, diastolic, systolic blood pressure in subjects with essential hypertension. In healthy volunteers, only a correlation between age and homocysteine concentration was found.

Heterologous strategy enhancing the sensitivity of the fluorescence polarization immunoassay of clinafloxacin in goat milk.

Clinafloxacin is used for the treatment of disease in food-producing animals, e.g. Brucella melitensis, which often occurs in goats; however, the clinafloxacin residue in goat milk may harm human health and result in the development of drug-resistant bacterial strains or allergies. Despite this, there is not a rapid, sensitive and accurate analytical method in goat milk for rapid screening or monitoring purposes. One homologous and five heterologous tracers were designed and compared for fluorescence polarization immunoassay (FPIA) optimization. Based on the combination of a heterologous tracer (PAZ-FITC, synthesized with pazufloxacin and FITC) and the antibody against clinafloxacin, a highly sensitive FPIA was established for the detection of clinafloxacin residue in goat milk for the first time. The IC50 value was 29.3 µg L(-1) for clinafloxacin in the heterologous format - six times lower than that of the combination of the homologous tracers and the antibody. The recoveries ranged from 86.8% to 104.5%, with the relative standard deviation ranging from 4.1% to 7.2%. Validation by high-performance liquid chromatography (HPLC) confirmed that the results obtained from the proposed FPIA were in agreement with those of HPLC. This proposed heterologous strategy for enhanced FPIA is sensitive and rapid enough for the high-throughput detection of clinafloxacin residue in goat milk.

Effect of xanthotoxin (8-methoxypsoralen) on the anticonvulsant activity of classical antiepileptic drugs against maximal electroshock-induced seizures in mice

The effects of xanthotoxin (8-methoxypsoralen) on the anticonvulsant activity of four classical antiepileptic drugs (carbamazepine, phenobarbital, phenytoin and valproate) were studied in the mouse maximal electroshock seizure model.Tonic hind limb extension (seizure activity) was evoked in adult male albino Swiss mice by a current (25mA, 500V, 50Hz, 0.2s stimulus duration) delivered via auricular electrodes. Total brain concentrations of antiepileptic drugs were measured by fluorescence polarization immunoassay to ascertain any pharmacokinetic contribution to the observed anticonvulsant effects.Results indicate that xanthotoxin (50 and 100mg/kg, i.p.) significantly potentiated the anticonvulsant activity of carbamazepine against maximal electroshock-induced seizures (P<0.05 and P<0.001, respectively). Similarly, xanthotoxin (100mg/kg, i.p.) markedly enhanced the anticonvulsant action of valproate in the maximal electroshock seizure test (P<0.001). In contrast, xanthotoxin (100mg/kg, i.p.) did not affect the protective action of phenobarbital and phenytoin against maximal electroshock-induced seizures in mice. Moreover, xanthotoxin (100mg/kg, i.p.) significantly increased total brain concentrations of carbamazepine (P<0.001) and valproate (P<0.05), but not those of phenytoin and phenobarbital, indicating pharmacokinetic nature of interactions between drugs.In conclusion, the combinations of xanthotoxin with carbamazepine and valproate, despite their beneficial effects in terms of seizure suppression in mice, were probably due to a pharmacokinetic increase in total brain concentrations of these antiepileptic drugs in experimental animals.

Determination of fluoroquinolone antibiotic levofloxacin in urine by fluorescence polarization immunoassay

A method of fluorescence polarization immunoassay (FPIA) has been developed for the determination of levofloxacin in urine. Fluorescein-tagged antigens (tracers) with various fluoroquinolones and fluorescent tags have been synthesized. The tracer based on garenoxacin labeled with 4-aminomethylfluorescein and polyclonal antibodies to levofloxacin was the most sensitive for the determination of fluoroquinolones. A FPIA method has been developed for the determination of levofloxacin with the limit of detection 1.0 ng/mL and analytical range from 2.5 to 50 ng/mL. A one-reagent FPIA method has been developed for the determination of levofloxacin with the limit of detection 0.5 ng/mL and analytical range from 1 to 10 ng/mL. The methods have been tested in the determination of levofloxacin in urine.

Effect of active infection on cytochrome P450-mediated metabolism of cyclosporine in renal transplant patients.

Infections downregulate cytochrome-P activities and thus may alter drug disposition, especially for drugs with a narrow therapeutic index. Cyclosporine (CyA), still used for the prevention of allograft rejection in renal transplant recipients in Egypt, seems to be affected by these infectious changes, based on random clinical observations. In the present study, the effects of bacterial and fungal infection on CyA metabolism were studied in renal transplant patients and subsequent nephrotoxicity was monitored. Twenty renal transplant patients, diagnosed with fungal or bacterial infection, were recruited from the renal transplantation outpatient clinic in Alexandria University Hospitals. No dose adjustment in CyA was performed at least 1 week before the onset of infection. Exclusion criteria were patients with acute or chronic unstable liver disease, elderly patients, and patients on concomitant drugs affecting CyA metabolism. CyA trough levels and serum creatinine (SCR) concentrations were measured by fluorescence polarization immunoassay and enzymatic assay, respectively, pre-infection, during infection and in many cases, post infection. CyA trough levels and SCR concentrations increased significantly during the infection (P < 0.001, P = 0.002) respectively. Of the patients, 87% experienced a concomitant rise in CyA trough level and SCR concentrations. No significant difference between pre-infection and post-infection levels of CyA trough and SCR was found. CyA trough and SCR levels increased during bacterial and fungal infections and returned to pre-infection levels once the infection was resolved. The data generated stress the importance of monitoring CyA levels during episodes of infection. Our recommendations concerning CyA dose adjustment differ according to severity and duration of infection.

Development of a Screening Fluorescence Polarization Immunoassay for the Simultaneous Detection of Fumonisins B1 and B2 in Maize

This paper reports the development of a screening fluorescence polarization immunoassay (FPIA) for the simultaneous detection of fumonisins B1 (FB1) and B2 (FB2) in maize. Three FB1 tracers including FB1-fluorescein isothiocyanate isomer I (FB1-FITC), FB1-5-([4,6-dichlorotriazine-2-yl]amino)-fluorescein (FB1-5-DTAF), and FB1-Texas Red-X succinimidyl ester (FB1-TRX) were synthesized and studied to select appropriate tracer-antibody pairs using seven previously produced monoclonal antibodies (mAbs). An FPIA employing the pair of FB1-FITC and mAb 4B9 showing 98.9% cross-reactivity (CR) toward FB2 was used to simultaneously detect FB1 and FB2. Maize flour samples were extracted with methanol/water (2:3, v/v). After optimization, the FPIA revealed a limit of detection (LOD) of 157.4 μg/kg for FB1 and an LOD of 290.6 μg/kg for FB2, respectively. Recoveries were measured for spiked samples of FB1 or FB2 separately, ranging from 84.7 to 93.6%, with a coefficient of variation (CV) of <9.9%. Total time needed for FPIA including sample pretreatment was <30 min. The FPIA was used to screen naturally contaminated maize samples. Results detected by FPIA showed good agreement with that of HPLC-MS/MS with a fit of R(2) = 0.99 for the simultaneous detection of FB1 and FB2. The established method offered a rapid, simple, sensitive, and high-throughput screening tool for the detection of fumonisins in maize.

Relative Bioavailability of Orally Administered Fosphenytoin Sodium Injection Compared with Phenytoin Sodium Injection in Healthy Volunteers

To describe the pharmacokinetics of fosphenytoin (FPHT) sodium injection when administered orally, and to determine the relative oral bioavailability (FREL ) of FPHT sodium injection compared with PHT sodium injection based on pharmacokinetic modeling in healthy volunteers. Open-label, randomized, single-dose, two-period, two-sequence crossover study. University-affiliated clinical research center funded by the National Center of Research Resources. Ten healthy adult volunteers. Subjects were randomized to receive a single oral dose of either PHT sodium injection or FPHT sodium injection at a dose equivalent to 400mg PHT acid. Blood samples were collected at baseline (just prior to administration) and at 0.5, 1, 2, 4, 6, 12, 24, 48, and 72hours after dose administration. After a 7-14-day washout period, the subjects underwent the same study procedures for administration of the other agent (PHT or FPHT). The mean age and weight of the 10 subjects were 37years and 72.5kg, respectively, and the mean dose was 5.6mg/kg based on PHT acid equivalence. The mean FREL of FPHT was 1.21 (95% confidence interval [CI] 1.07-1.35). Serum PHT concentrations were determined by fluorescence polarization immunoassay. The median (range) maximum serum concentration (Cmax ) values were significantly higher after FPHT administration compared with PHT: 10.7 (9.0-19.4) mg/L versus 5.0 (3.2-8.9) mg/L (p=0.002). The PHT concentration after oral administration of FPHT displayed faster absorption compared with PHT, with a median (range) time to reach Cmax of 1.0 (0.5-2.0) hours versus 6.0 (2.0-24.0) hours (p=0.008). All subjects completed the study without any serious adverse events reported. FPHT sodium injection given orally was absorbed more rapidly and to a significantly greater extent than PHT sodium injection given orally to healthy volunteers. Further evaluation of oral FPHT as an alternative in patients requiring enteral feedings is warranted.

Plasma B-type Natriuretic Peptide (BNP) as a marker of left ventricular diastolic dysfunction in diabetic patients

The first stage of diabetic cardiomyopathy is represented by left ventricular diastolic dysfunction (LVDD) with preserved systolic function, in an asymptomatic patient. B-type Natriuretic Peptide (BNP) is a cardiac neurohormone predominantly released from the cardiac ventricles in response to left ventricular volume expansion and pressure overload. The diagnostic role of BNP for detecting LVDD in asymptomatic diabetic patients is still debated and this study was undertaken to find out this relationship of plasma BNP level with LVDD in asymptomatic diabetic patients. First 100 patients who had type 2 diabetes for more than 5 years and had no known cardiac disease other than LVDD (grade-1 &amp; 2), admitted in BIRDEM Hospital were recruited. Plasma BNP was measured by fluorescence polarization immunoassay (FPIA) method using AXSYM auto analyzer. Twodimensional, M-mode, spectral, and color flow Doppler echocardiograms was repeated on the same day of blood collection for plasma BNP measurement. After processing of all available data, statistical analysis of their significance was done with the help of computer based SPSS (Statistical Program for Social Science) program. Male female distribution of the study participants was 46% and 54% respectively. Mean plasma BNP level in all participants was 150 pg/ml. In male and female participants the values were 168 and 135 pg/ml respectively. The distribution did not show any significant association (p=0.491). Of the 100 study participants 89% had E/A ratio &lt;1. Distribution of participants with abnormal E/A and E/e did not show any significant association (p=0.955 and 0.844 respectively). Study participants with varying level of plasma BNP level were analyzed in terms of E/A and E/e ratio. Distribution of participants between BNP Groups and E/A and E/e groups did not show statistically significant association (p=0.529). We concluded that plasma BNP has no relation with LVDD (grade- 1 and 2) in patients with type 2 diabetes mellitus (T2DM) who had no known cardiac disease.Ibrahim Med. Coll. J. 2014; 8(1): 1-5