Leukotriene B4 and late asthmatic reactions induced by toluene diisocyanate

1990 ◽  
Vol 68 (4) ◽  
pp. 1576-1580 ◽  
Author(s):  
E. Zocca ◽  
L. M. Fabbri ◽  
P. Boschetto ◽  
M. Plebani ◽  
M. Masiero ◽  
...  
Keyword(s):  
High Performance ◽  
Leukotriene B4 ◽  
Toluene Diisocyanate ◽  
Reverse Phase ◽  
The Third ◽  
Specific Radioimmunoassay ◽  
Asthmatic Reaction ◽  
The Mean ◽  
Late Asthmatic Reaction ◽  
Mean Concentration

We investigated whether leukotriene B4 (LTB4) is released from the lungs of sensitized subjects during asthmatic reactions induced by toluene diisocyanate (TDI). We examined three groups of TDI-sensitized subjects, one after no exposure to TDI, the second 8 h after an exposure to TDI that caused an early asthmatic reaction, and the third 8 h after an exposure to TDI that caused a late asthmatic reaction. We analyzed bronchoalveolar lavage (BAL) fluid by reverse-phase high-performance liquid chromatography and by specific radioimmunoassay. The mean concentration of LTB4 was higher [0.31 +/- 0.09 (SE) ng/ml, range 0.15-0.51] in BAL fluid of sensitized subjects who developed a late asthmatic reaction than in BAL fluid of subjects who developed an early asthmatic reaction (0.05 +/- 0.04 ng/ml, range 0-0.224), and no LTB4 was detectable in the control subjects. We also performed BAL 8 h after TDI exposure on four TDI-sensitized late-dual reactors who were on steroid treatment. In this group of subjects no LTB4 was detectable. These results suggest that LTB4 may be involved in late asthmatic reactions induced by TDI.

Specific 3H radioimmunoassay with a monoclonal antibody for monitoring cyclosporine in blood.

1988 ◽  
Vol 34 (2) ◽  
pp. 257-260 ◽  
Author(s):  
P E Ball ◽  
H Munzer ◽  
H P Keller ◽  
E Abisch ◽  
J Rosenthaler
Keyword(s):  
Monoclonal Antibody ◽  
Bone Marrow ◽  
High Performance Liquid Chromatography ◽  
High Performance ◽  
Limit Of Detection ◽  
Parent Drug ◽  
Sample Volume ◽  
Specific Radioimmunoassay ◽  
The Mean ◽  
Blood Specimens

Abstract A specific radioimmunoassay involving a mouse monoclonal antibody to cyclosporine has been developed for monitoring the parent drug in blood. Pretreatment with methanol removes cyclosporine from the erythrocytes. The limit of detection is about 12 micrograms/L, sample volume is 50 microL of blood, and within- and between-assay CVs are less than 7%. Assay results correlated well with those obtained by "high-performance" liquid chromatography (HPLC) for liver (n = 42), for heart (n = 64), for bone-marrow (n = 36), and for kidney (n = 140). For blood specimens obtained from patients treated with cyclosporine postoperatively for as long as 65 months, the mean RIA/HPLC ratio in all with transplant indications was close to 1. Therefore, the specific radioimmunoassay apparently can be used instead of HPLC to measure the parent drug in blood.

scholarly journals The Effect of Surgery on the Concentration of Circulating Megakaryocytes and Platelets

Blood ◽  
1968 ◽  
Vol 32 (3) ◽  
pp. 393-401 ◽  
Author(s):  
ALEXANDER BRESLOW ◽  
RICHARD M. KAUFMAN ◽  
ALAN R. LAWSKY
Keyword(s):  
Maximal Level ◽  
Men And Women ◽  
The Third ◽  
Antecubital Vein ◽  
Platelet Concentration ◽  
The Mean ◽  
Normal Men ◽  
Mean Concentration

Abstract The mean concentration of megakaryocytes in antecubital vein blood of 43 normal men and women was 3.4/ml. (range 0-13). No circulating megakaryocytes were found in 6 patients with thrombocytopenia due to marrow failure. Following surgery the average maximal megakaryocyte level increased to 50/ml. (range 15-190) from a preoperative mean of 8/ml. The maximal level was reached on about the third postoperative day with the platelet concentration reaching maximal levels 3 to 6 days later.

RADIOIMMUNOASSAY OF 3,3′-DI-IODOTHYRONINE IN UNEXTRACTED SERUM: THE EFFECT OF ENDOGENOUS TRI-IODOTHYRONINE

1978 ◽  
Vol 79 (3) ◽  
pp. 357-362 ◽  
Author(s):  
T. J. VISSER ◽  
L. M. KRIEGER-QUIST ◽  
R. DOCTER ◽  
G. HENNEMANN
Keyword(s):  
Human Serum ◽  
Limit Of Detection ◽  
Cross Reactivity ◽  
Transport Proteins ◽  
Normal Serum ◽  
Serum Concentrations ◽  
Specific Radioimmunoassay ◽  
Highly Sensitive ◽  
The Mean ◽  
Mean Concentration

The development of a highly sensitive and specific radioimmunoassay for 3,3′-di-iodothyronine (3,3′-T2) is described. The assay was applied to the measurement of 3,3′-T2 in unextracted human serum and used 8-anilino-l-naphthalene-sulphonic acid to inhibit the binding of 3,3′-T2 to serum transport proteins. The lower limit of detection of the assay was 2 fmol 3,3′-T2 per tube, which corresponded to 10 pmol 3,3′-T2/l serum. The mean concentration of 3,3′-T2 in normal serum was found to be 23 pmol/l, which is considerably lower than most values reported previously. Evidence is presented which suggests that the cross-reactivity of tri-iodothyronine with the antiserum to 3,3′-T2 is an important factor in the measurement of serum concentrations of 3,3′-T2 by radioimmunoassay.

CORTISOL AND CORTISONE IN SALIVA OF PREGNANCY

1963 ◽  
Vol 26 (2) ◽  
pp. 189-195 ◽  
Author(s):  
M. S. GREAVES ◽  
H. F. WEST
Keyword(s):  
Rheumatoid Arthritis ◽  
Salivary Gland ◽  
Pregnant Women ◽  
Connective Tissues ◽  
Third Trimester ◽  
The Third ◽  
Reasonable Explanation ◽  
The Mean ◽  
Mixed Saliva ◽  
Mean Concentration

SUMMARY The concentration of cortisol and cortisone in mixed saliva has been measured in normal non-pregnant women, normal pregnant women in the third trimester of pregnancy and pregnant ones with mild toxaemia in the third trimester. The ratio of cortisol to cortisone was 1:4 for the non-pregnant and 1:5 for the pregnant women. The mean concentration of cortisol for the pregnant subjects was twice that of the non-pregnant and the mean concentration of cortisone three times that of the non-pregnant women. Filtration studies showed no significant binding of cortisol or cortisone in the saliva. It is concluded that the raised concentration of cortisol and cortisone in saliva indicates a raised concentration in the cells of the salivary gland. If this rise is common to the connective tissues generally it provides a reasonable explanation for the remission of rheumatoid arthritis experienced by some patients in the latter months of pregnancy.

IDENTIFICATION OF A NEUTROPHIL ELASTASE CLEAVAGE SITE ON THE Act -CHAIN OF PRIMATE FIBRINOGEN

1987 ◽  
Author(s):  
J Weitz ◽  
S Landman ◽  
S Birken
Keyword(s):  
Neutrophil Elastase ◽  
Cleavage Site ◽  
High Performance ◽  
Human Neutrophil Elastase ◽  
Amino Acid Sequence Analysis ◽  
Specific Radioimmunoassay ◽  
Human Thrombin ◽  
The Mean

Human neutrophil elastase (HNE) cleaves the Aα21-22 bond of fibrinogen thus releasing the fibrinopeptide A (FPA)-containing fragment Aαl-21. Plasma Aal-21 levels reflect in vivo HNE activity and peptide levels are increased in cigarette smokers and patients with chronic lung disease. To further explore the HNE-fibrinogen interaction, we set out to develop an animal model. The digestion of purified baboon and marmoset fibrinogen by human thrombin, HNE and extracts of baboon and marmoset neutrophils was monitored with a specific radioimmunoassay for human FPA. Thrcmbin produced quantitative release (2 mol/mol fibrinogen) of FPA. In contrast, HNE and the neutrophil extracts did not release FPA, but rather, produced quantitative release of a larger, FPA-containing fragment. Immunochemically, this fragment was clearly distinguishable from FPA in that in vitro thrombin treatment increased its immunoreactivity 1,000-fold (thrombin increasable FPA or TIFPA). TIFPA release by the neutrophil extracts was blocked by α1-proteinase inhibitor, a specific HNE inhibitor (MeO-Suc-Ala2-Pro-ValCH2Cl) and an anti-HNE IgG, indicating that elastase was the responsible proteinase and that there was homology between the human and primate enzymes. The products of HNE and neutrophil extract proteolysis of the primate fibrinogens were then separated by high performance liquid chromatography and the TIFPA-containing fractions were subjected to amino acid sequence analysis. The FPA-containing fragments each consisted of 21 amino acids, had minor substitutions when compared with human A α] -21 [Baboon: Aα(3) Ser - Thr; Marmoset Aα(l) Ala - Thr, Aα(3) Ser - Thr, Aα(ll) Glu - Ala], and exhibited complete crossreactivity with the human peptide. Using the TIFPA assay, there was good recovery of primate or human Aαl-21 added to primate blood and the mean peptide level in 8 healthy marmosets was similar to that in man (0.5 nM and 0.4 nM, respectively). In conclusion, (1) the Aα;21 -22 bond of baboon and marmoset fibrinogen is a cleavage site for human and primate elastase, (2) baboon and marmoset Aal-21 can be measured with the assay for the human peptide, and (3) the primate serves as a useful model for the study of elastase-fibrinogen interactions.

scholarly journals METHOD DEVELOPMENT AND VALIDATION OF EPROSARTAN MESYLATE AND ITS IMPURITIES USING REVERSE PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

2016 ◽  
Vol 8 (4) ◽  
pp. 49 ◽  
Author(s):  
O. S. S. Chandana ◽  
D. Sathis Kumar ◽  
R. Ravichandra Babu
Keyword(s):  
High Performance ◽  
Method Development ◽  
Hplc Method ◽  
Reverse Phase ◽  
Related Substances ◽  
Rp Hplc ◽  
Method Development And Validation ◽  
The Mean ◽  
Development And Validation

Objective: Our main objective is to develop an accurate and precise RP-HPLC method for the determination of Eprosartan Mesylate and its impurities. Methods: A Develosil ODS UG-5; (150 × 4.6) mm; 5 µm column was used for the Separation of drugs by a mobile phase consisting of Buffer and Acetonitrile mixture in the gradient proportion. The flow rate maintained was 0.8 ml/min and the wavelength used for detection was 235 nm.Results: The linearity was observed in the range of 0.025-50µg/ml of spiked impurities in Eprosartan Mesylate, impurity 1 and impurity 2 with a correlation coefficient of 0.99927, 0.99910 and 0.99934 respectively. The mean percentage recoveries for LOQ, 50%, 80%, 100%, 150% and 200% accuracy were found to be 101.5±1.51, 107.0±1.7, 104.6±0.4, 102.8±0.36, 101.7±0.26 and 101.3±0.15 respectively for impurities in Eprosartan Mesylate, impurity 1 and impurity 2. Linearity, accuracy, precision and robustness parameters for the suggested method were estimated for validation.Conclusion: The developed method is uncomplicated, accurate, sensitive and precise for the determination of related substances in the Eprosartan Mesylate. The satisfying % recoveries and low % RSD Values confirmed the suitability of the developed method for the usual analysis of Eprosartan mesylate in pharmaceuticals.

scholarly journals A Limited Survey of Aflatoxins and Zearalenone in Feed and Feed Ingredients from Pakistan

2016 ◽  
Vol 79 (10) ◽  
pp. 1798-1801 ◽  
Author(s):  
SHAHZAD ZAFAR IQBAL ◽  
MUHAMMAD RAFIQUE ASI ◽  
SONIA NISAR ◽  
KHALID MAHMOOD ZIA ◽  
SELAMAT JINAP ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
High Performance ◽  
Poultry Feed ◽  
Fluorescence Detector ◽  
Limit Of Quantification ◽  
Feed Ingredients ◽  
Cotton Seed Meal ◽  
The Mean ◽  
Mean Concentration ◽  
Feed Samples

ABSTRACT This work presents current information on the presence of aflatoxins (AFs) and zearalenone (ZEN) in feed and feed ingredients from Punjab, Pakistan. The 105 samples tested were concentrated feed, i.e., cotton seed meal (18 samples) and soybean meal (14), and feed ingredients, i.e., crushed corn (17), crushed wheat (15), barley (17). and poultry feed (24). Samples were analyzed using high-performance liquid chromatography equipped with a fluorescence detector. Analysis revealed that 69 of 105 samples were contaminated with AFs, and the highest mean concentrations of AFB1 (6.20 μg/kg) and total AFs (9.30 μg/kg) were found in poultry feed samples. The mean total AF concentrations ranged from the limit of quantification to 165.5 μg/kg. However, 75 of the 105 samples were positive for ZEN. The highest mean concentration (19.45 μg/kg) was found in poultry feed samples. The mean ZEN concentrations were 0.15 to 145.30 μg/kg. The prevalence of AFs and ZEN was high in feed and feed ingredients and needs urgent attention.

scholarly journals BISPHENOL A DETECTION IN PACKAGED DRINKING WATER AND BEVERAGES USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

2021 ◽  
Vol 9 (03) ◽  
pp. 111-117
Author(s):  
Neha P. Sangai ◽  
◽  
Himanshu A. Pandya ◽  
Keyword(s):  
Drinking Water ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Bisphenol A ◽  
High Performance ◽  
Bottled Water ◽  
High Concentration ◽  
Bottled Drinking Water ◽  
The Mean ◽  
Mean Concentration

Background: Bisphenol A is characterized as an endocrine disruptor as it interferes with the synthesis of hormones and metabolism resulting in abnormality in the homeostatis of exposed persons. It is used in the production of polycarbonate and epoxy resins which are utilized in the preparation of almost all plastic packaging materials like plastic bottles, cans, food containers, and coating on food containers. Objective: To detect leaching of Bisphenol A in 15 samples of Bottled water and Beverages using High Performance Liquid Chromatography. Methods: Liquid-liquid extraction technique was used for analytical detection of BPA from bottled drinking water and beverages. Results: BPA contamination in Bottled drinking water was calculated through mean concentration for a time period of 30 days as (0.38 ng/ml - 0 day), 8.86 ng/ml (5th day), 17.85 ng/ml (10th day), 30.35 ng/ml (20th day) and 44.48 ng/ml (30th day)). The mean concentration of BPA was observed to be 0.25 to 2.25 ng/ml. Also, the mean concentration of BPA at different temperatures was observed to be 5.96 ng/ml (at 40C), 5.62 ng/ml (at 200C) and 8.80 ng/ml (at 550C). The above results revealed presence of high concentration of BPA in all the samples of bottled drinking water and beverages. Conclusion: The results obtained in the above study depicted considerable amount of BPA leaching from bottled containers into drinking water and beverages. Prolong usage of bottled water and beverages should be avoided to reduce the risk of human exposure to BPA through leaching. Also, it was found that high temperatures resulted in increased BPA leaching.

Occurrence of Patulin in Organic, Conventional, and Handcrafted Apple Juices Marketed in Belgium

2006 ◽  
Vol 69 (6) ◽  
pp. 1371-1378 ◽  
Author(s):  
KATLEEN BAERT ◽  
BRUNO DE MEULENAER ◽  
ANALICE KAMALA ◽  
CHITUNDU KASASE ◽  
FRANK DEVLIEGHERE
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Apple Juice ◽  
Analytical Procedure ◽  
Uv Detection ◽  
Legal Limit ◽  
Two Samples ◽  
The Mean ◽  
Mean Concentration

The aim of this research was to compare the occurrence of patulin in a large group of organic, conventional, and handcrafted apple juices marketed in Belgium. An analytical procedure based on high-performance liquid chromatography with UV detection was validated and used to analyze 177 apple juice samples: 65 organic, 90 conventional, and 22 handcrafted. Patulin was detected in 22 samples (12%), and quantification was possible in 10 (6%) of these samples. The patulin content was higher than the European legal limit of 50 μg/liter in two samples of organic apple juice. Although, the incidence of patulin in organic (12%), conventional (13%), and handcrafted (10%) apple juices was not significantly different (P = 0.863), the mean concentration of patulin in contaminated samples was significantly higher in organic (43.1 μg/liter) than in conventional (10.2 μg/liter) (P = 0.02) and handcrafted (10.5 μg/liter) (P = 0.037) apple juice. The highest patulin concentrations were found in the most expensive apple juices because of the higher price of organic apple juice. This relation was not observed when only conventional apple juices were analyzed.

A high performance liquid chromatographic assay for the mycotoxin phomopsin A in lupin stubble

1987 ◽  
Vol 27 (1) ◽  
pp. 73 ◽  
Author(s):  
GR Hancock ◽  
P Vogel ◽  
DS Petterson
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
High Performance Liquid Chromatographic ◽  
Exchange Chromatography ◽  
Reverse Phase ◽  
Extraction And Purification ◽  
Wide Range ◽  
Total Analysis ◽  
The Mean ◽  
Liquid Chromatographic

An assay using high performance liquid chromatography to measure phomopsin A, the principal mycotoxin responsible for lupinosis is described. Samples of lupin stubble are extracted with methanol: water and purified by partitioning between n-butanol and water, chromatography on Amberlite XAD-2 and by cation exchange chromatography. The analysis is performed on a reverse phase C18 column using a methanol:water gradient and UV detection. The limit of detection for this procedure is 0.5 mg phomopsin A per kg stubble. Improvements to the extraction and purification procedures were made and total analysis time was reduced to 2 days. The mean (� s.d.) recovery for the purification procedure was 64.3 � 4.5% over a wide range of concentrations.

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