Identification of potential serum metabolic biomarkers for patient with keratoconus using untargeted metabolomics approach.

This study aimed to investigate the metabolite differences between patients with keratoconus and control subjects and identify potential serum biomarkers for keratoconus using a non-targeted metabolomics approach. Venous blood samples were obtained from patients with keratoconus (n = 20) as well as from age-, gender- and race-matched control subjects (n = 20). Metabolites extracted from serum were separated and analyzed by liquid chromatography/quadrupole time-of-flight mass spectrometer. Processing of raw data and analysis of the data files was performed using Agilent Mass Hunter Qualitative software. The identified metabolites were subjected to a principal component and hierarchical cluster analysis. Appropriate statistical tests were used to analyze the metabolomic profiling data. Together, the analysis revealed that the dehydroepiandrosterone sulfate from the steroidal hormone synthesis pathway was significantly upregulated in patients with keratoconus (p < 0.05). Also, a combination of eicosanoids from the arachidonic acid pathway, mainly prostaglandin F2α, prostaglandin A2, 16,16-dimethyl prostaglandin E2, and 5-hydroxyeicosatetraenoic acid were collectively up-regulated as a group in keratoconus patients (p < 0.05). On the other hand, glycerophospholipid PS(17:2(9Z,12Z)/20:4(5Z,8Z,11Z,14Z)) was found to be significantly upregulated in the metabolomics profiles of control subjects (p < 0.05). The differently regulated metabolites provide insights into the pathophysiology of keratoconus and could potentially be used as biomarkers for keratoconus to aid in screening for individuals at risk hence, enabling early diagnosis and timely monitoring of disease.

Effects of a carrot juice intervention on plasma carotenoids, oxidative stress, and inflammation in overweight breast cancer survivors.

Evidence suggests that higher plasma carotenoid concentrations are protective in relation to breast cancer recurrence. This simple randomized carrot juice intervention study was designed to test the hypothesis that daily intake of 8 ounces of fresh BetaSweet (anthocyanin-rich) or Balero orange carrot juice would increase plasma total carotenoid concentrations to levels previously shown to be associated with reduced breast cancer recurrence. It was hypothesized that regular carrot juice intake would be associated with reductions in oxidative stress (8-iso-PGF2α) and inflammation (thromboxane B2, prostaglandin E2 metabolites, and hsC-reactive protein). Sixty-nine overweight breast cancer survivors consumed fresh carrot juice made from study-provided carrots for 3 wk. Total plasma carotenoids increased by 1.65 and 1.38 umol/L for the BetaSweet and Balero carrot juice, respectively. Rise in total plasma carotenoids for the overall sample was inversely associated with 8-iso-PGFα (OR: 0.13; 95% CI: 0.20 to 0.75; no differences were shown by carrot variety. These results suggest daily intake of fresh carrot juice is a simple and effective approach to increasing plasma total carotenoids and in turn reducing oxidative stress, but not inflammatory markers, in women previously treated for breast cancer.

A radioimmunoassay for prostaglandin A1 in human peripheral blood.

A specific, sensitive and accurate radioimmunoassay (RIA) method for the measurement of prostaglandin A1 (PGA1) in either human whole blood or plasma is described. Whole blood is immediately lysed with distilled water containing tritiated indicator. When plasma is assayed, the blood samples are handled at 4 C and rapidly centrifuged. The lysate or plasma is adjusted to pH 5 with buffer and quickly extracted with 5% methanol in dichloromethane. The whole blood or plasma extract is then purified by Sephadex LH20 chromatography using the system methanol: methylene chloride (5:95) which separates the major groups of PGA, PGE and PGF. The RIA is then performed using an antiserum generated in rabbits from PGA1 coupled to bovine thyroglobulin. The antibody is highly specific, possessing very low cross reactivity to other prostaglandins (PGA2, PGE, PGB and PGF). Activated florisil or ammonium sulfate can be used to separate bound from free prostaglandin. This whole blood or plasma method yields blank values of only 2 +/- 2 pg per sample with a between assay precision determined by duplicate analysis of 8% and interassay precision of 3%. The mean whole blood PGA1 concentration in 27 subjects in 2.5 +/- 1.6 (SD) ng per 100 ml. No significant sex difference in PGA1 levels was noted and values were similar whether measured in whole blood or cooled plasma rapidly prepared and extracted. These values of PGA1 are much lower than those RIA values reported by others for "PGA" using antibodies with lower specificities.

The effect of aspirin and indomethacin on the TRH response in man.

A double-blind study of the effect of two inhibitors of prostaglandin synthesis on the TRH stimulation of serum TSH and prolactin was carried out in 35 normal males. The subjects were evaluated before and after the administration of indomethacin or aspirin for one week. Both indomethacin and aspirin lowered plasma prostaglandin E and F levels significantly. Indomethacin treatment had no effect on the serum TSH or prolactin response to 100 mug TRH or the serum T3 and T4 levels. In contrast, aspirin treatment significantly decreased the serum TSH response to TRH and significantly lowered mean total serum T3 (RIA) and T4 (D). There was no effect on the prolactin response to TRH. These findings suggest that aspirin blocks TRH responsiveness by a mechanism other than the inhibition of prostaglandin synthesis, probably by its previously demonstrated effect on increasing the fraction of unbound thyroid hormone.

Role of prostaglandins in the pathogenesis of Bartter's syndrome.

Increased renal prostaglandins activated by beta-catecholamines could produce renal tubular sodium wasting and angiotensin pressor resistance observed in Bartter's syndrome. We therefore measured plasma renin activity (PRA), aldosterone and prostaglandin A (PGA) by radioimmunoassay, and body composition by isotope dilution prior to and following beta-adrenergic blockade with propranolol (200 mg/day for 4 days) and prostaglandin synthesis inhibition by indomethacin (200 mg/day for 4 days) in a patient with Bartter's syndrome on a 250 meq sodium diet. After the administration of propranolol, body weight increased 3 kg, daily urine sodium decreased within 24 hours from 230 to 64 meq, and urine potassium from 102 to 45 meq, but PRA and the aldosterone level remained elevated. With the administration of indomethacin, body weight increased 5 kg, daily urinary sodium decreased within 24 hours to 11meq and urine potassium to 16 meq, PRA (normal less than 3 ng/100 ml/hour) decreased from 55 to 4.3 ng/ml/hour, plasma aldosterone (normal less than 8 ng/100 ml) from 74.1 to 3.6 ng/100 ml, and whole blood PGA (normal 546 +/- 307 pg/ml) decreased from 1,390 and 945 to 86 pg/ml. After the administration of propranolol or indomethacin, exchangeable sodium, total body water, extracellular volume and plasma volume all increased from less than to greater than predicted, and pressor resistance to angiotensin was normalized. These results suggest that Bartter's syndrome results from beta adrenergic and prostaglandin-mediated proximal tubular rejection of sodium leading to increased distal sodium-potassium exchange.

Fate of prostaglandins E(1) and A(1) in the human pulmonary circulation.

It is recognized that the lung extracts norepinephrine and 5-hydroxytryptamine from the pulmonary circulation and that this process is affected by cardiopulmonary bypass. Since alterations in the lung's processing of vasoactive substances may be a mechanism of pulmonary injury sustained during operation, we investigated the lung's ability to extract or metabolize prostaglandin A1 (ga1) and prostaglandin E1 (PGE 1). Sixteen patients undergoing cardiac surgery were studied. In five patients, just before going on bypass, a 10 ml of blood was withdrawn at a constant rate, simultaneously from the pulmonary artery and left atrium. In 11 patients, 3H-PGE1 was injected just prior to bypass and, in five of these, again after coming off bypass. Extraction was calculated from tritium activity in the samples. Metabolites were quantitated by thin-layer chromatography after being identified by marker compounds run simultaneously in each chromatogram. The pulmonary extraction of PGA1 was 11.3 +/- 2.3% and there were no detectable metabolites in left atrial blood. Before bypass the extraction of PGE1 was 42.3 +/- 14.3% and after bypass 24.8 +/- 10.0% (P less than 0.005; Student's paired t test). PGE1 was extensively metabolized with 79.7 +/- 7.1% of total radioactivity appearing in the left atrium as metabolites before bypass and 89.1 +/- 2.0% appearing after bypass. This study indicates that PGA(1) is not metabolized by the lung and is only slightly extracted. On the other hand, PGE(1) is extensively extracted and metabolized. While the rate of metabolism is not significantly affected by cardiopulmonary bypass, the extractiom before bypass was significantly greater than after bypass.

Plasma prostaglandins in pregnancy.

Plasma prostaglandins were determined by radioimmunoassay in 92 pregnant and 14 nonpregnant women. There was significant elevation of PGA-like material in the first trimester of pregnancy (1744 pg/ml) over that seen in nonpregnant women (576 pg/ml) with continuation of that elevation in the second and third trimesters. No significant difference existed among PGE levels of the nonpregnant group (251 pg/ml) and the first two trimesters of pregnancy (384 pg/ml and 294 pg/ml); the PGE level of the third trimester group (443 pg/ml) was significantly elevated over that of the nonpregnant group. PGF levels remained constant during all trimesters (135 pg/ml, 144 pg/ml, and 130 pg/ml) but exhibited plasma concentrations significantly higher than the nonpregnant group (78 pg/ml). Potential role (s) of prostaglandins as mediators of cardiovascular and renal changes of pregnancy are discussed.

Rapid antibody production and sample preparation for radioimmunoassay of prostaglandin A.

A dialysis equilibrium method for plasma or tissue preparation for radioimmunoassay of prostaglandins is presented and compared to the silica gel column technique. The plasma or tissue is extracted, dried, redissolved in buffer and dialyzed for further purification before assay. Results comparing both methods shows that dialysis equilibrium greatly simplifies the silica gel column technique yet preserves specificity, sensitivity and reproducibility. In addition a rapid micromethod for the development of a specific antibody to prostaglandin A is detailed.

Prostaglandins and hypertension in chronic renal diseases.

The role of prostaglandin A (PG A) in the pathogenesis of renal hypertension has been studied. The concentration of endogenous PG A was measured in the peripheral plasma by radioimmunoassay in patients with chronic renal disease and in control subjects. The mean plasma concentration of PG A1 equivalents was as follows: 1. normotensive healthy volunteers (n=23): 115 +/- 15 pg/ml 2. patients in terminal renal failure on regular hemodialysis a) anephric patients (n=6): 51+/- 21 pg/ml b) patients retaining their own kidneys, all but one with hypertension (n=9): 231 +/- 51 pg/ml (P less than 0.01 versus control) 3. patients with chronic renal disease a) with hypertension (n=7): 204 +/- 60 pg/ml (P less than 0.01 versus control) b) without hypertension (n=11): 136 +/- 30 pg/ml. Renal hypertension was associated with high levels of PG A in peripheral blood. This increase is probably a secondary adaptative mechanism for the excretion of a greater fraction of the glomerular filtrate at a lower blood pressure. PG A may represent a circulating "antihypertensive hormones".

The fate of prostaglandin A1-5,6-3H in the rat.

The plasma concentrations, tissue distribution and excretion of prostaglandin A1 (PGA1) and related metabolites have been determined in rats, following the intravenous injection of a single dose of PGA1-5,6-3H. Urinary and faecal excretion accounted for averages of 25 and 43% of the administered dose of PGA1, respectively. Oxidative cleavage of the carboxyl side chain of PGA1 appeared to be a major metabolic pathway in the rat. PGA1-5,6-3H was deemed unsuitable for metabolism studies in man, in view of the significant loss of tritium label from the prostaglandin;

[Prostaglandins and benign mastopathies (author's transl)]. / Prostaglandines et mastopathie bénigne.

During both phases of their menstrual cycle, women who suffer from benign mastopathies evidence hormonal deficiency, which is total although of variable magnitude, as shown by oestradiol (E2) and progesterone (p) plasma levels. by contrast, these women show a concomitant and large rise of prostaglandin E2 (PGE2) plasma level. An oestrogen directed PGE2 synthesis by the mammary epithelium is likely to occur. The patients whose mammary thermography displays PG synthesis can be cooled by the administration of PG synthesis inhibitors. They show a steroid deficiency which is more or less pronounced without having any marked imbalance of the E2-P ratio. By contrast, patients who exhibit no thermographic response show a marked relative rise in oestrogen during both phases of the menstrual cycle. The significance of PG synthesis and relatively raised oestrogen levels will be discussed in relationship to the risk of breast cancer.

[Comparison of the blood plasma depressor prostaglandin content and the indicators of hemodynamics in dogs with experimental myocardial infarct and cardiogenic shock]. / Sopostavlenie soderzhaniia depressornykh prostaglandinov v plazme krovi i pokazatelei gemodinamiki u sobak s eksperimental'nym infarktom miokarda i kardiogennym shokom.

The quantitative composition of depressor prostaglandins PGE1 and PGA1 in the plasma of arterial and venous blood and blood from the great cardiac vein was studied in comparison with the values of hemodynamics in dogs with experimental myocardial infarction and cardiogenic shock. The content of prostaglandins in blood plasma was determined by the radioimmune method. The development of acute coronary insufficiency was attended with changes in the quantitative composition of the depressor PGE1 and PGA1 in the plasma of arterial and venous blood and blood from the great cardiac vein. In myocardial infarction and particularly in cardiogenic shock, intensification of PGE1 and PGA1 synthesis and an increase in the consumption of these PG by the myocardium occurred beginning with the first hours following occlusion of the coronary arteries, which suggests that PGE1 and PGA1 may probably take part in the normalization of the activity of the affected heart.

[Quantitative composition of blood plasma prostaglandins in patients with ischemic heart disease]. / Kolichestvennyi sost v prostaglandinov plazmy krovi u bol'nykh ishemicheskoi bolezn'iu serdtsa

From the blood plasma of 34 patients with ischemic heart disease and hyperlipoproteinemia and without it and in 10 practically healthy persons prostaglandins E, A and F2alpha were isolated and the proportion of each one of them was determined by the radioimmunological method. Changes in the quantitative composition of the blood plasma prostaglandins in patients with ischemic heart disease and hyperlipoproteinemia were disclosed, these changes suggesting the participation of the substances in question in the pathogenesis of atherosclerosis.

[Content of prostaglandins E and A in the blood serum and kidneys of rabbits with vasorenal hypertension (study by radioimmunoassay)]. / Soderzhanie prostaglandinov E i A v syvorotke krovi i pochkakh krolikov s vazorenal'noi gipertoniei (radioimmunnoe issledovanie).

The content of depressor prostaglandins E and A was studied in the blood serum and cortical layer of the kidneys of 52 chinchilla rabbits with renovascular hypertension by way of radioimmunoassay using reagent kits of "Clinical Assay, Inc." (USA). The experimental and control rabbits were sacrificed in batches 1, 4, and 8 weeks after surgery. Some mechanisms of the participation of prostaglandins E and A in the pathogenesis of renovascular hypertension are discussed.

[Concentration of depressor and pressor prostaglandins in the blood of patients with cerebral hypertensive crises]. / Soderzhanie depressornykh i pressornykh prostaglandinov v plazme krovi u bol'nykh s tserebral'nymi gipertonicheskimi krizami.

The content of depressor and pressor prostaglandins in the blood plasma was examined by radioimmunology during different stages of hypertonic disease and in cerebral hypertensive crises. The achieved results were correlated with the data concerning the content of prostaglandins in normal individuals. These studies permitted to demonstrate certain changes in the level of pressor and depressor prostaglandins depending upon the stage of the hypertensive disease and crises states. In this respect the obtained facts allow to assume that prostaglandins play a certain role in the pathogenesis of different traits of the hypertensive disease.

[Prostaglandins A1, E1 and F2 alpha concentrations in the arterial and coronary venous blood of patients with ischemic heart disease during induced myocardial ischemia]. / Soderzhanie prostaglandinov A1, E1, F2 alpha v arterial'noi i koronarnoi venoznoi krovi u bol'nykh ishemicheskoi bolezn'iu serdtsa pri indutsirovannoi ishemii miokarda.

Prostaglandins (PGA1, PGE1 and PGF2 alpha) were assayed in 15 patients with chronic coronary disease during an anginal attack induced through frequent atrial stimulation. Measurements from eleven patients with intact coronary arteries served as control. Lactate extraction coefficient was used as a biochemical indicator of myocardial ischemia; the latter was associated with increased production of coronary sinus PGF2 alpha and arterial PGA1. No correlation could be established between PG levels in the studied series, the extent of ST depression on electrocardiograms, lactate extraction level and hemodynamic manifestations.

[Plasma prostaglandin reaction to furosemide in healthy persons and in hypertension patients consuming salt in an excessive amount]. / Reaktsiia prostaglandinov plazmy krovi na furosemid u zdorovykh liudei i bol'nykh gipertonicheskoi bolezn'iu, upotrebliaiushchikh sol' v izbytochnom kolichestve.

The content of prostaglandins A, E, and F in healthy individuals and in persons with hypertensive disease who had taken salt in excess throughout life was studied by the radioimmune method. The reaction of blood prostaglandins to intravenous infusion of 40 mg of furosemid was watched. It was found that excessive intake of salt is attended with a decrease in the blood prostaglandin E content in healthy individuals and in persons suffering from hypertensive disease. The prostaglandin A content increases simultaneously, evidently for compensation, while the level of prostaglandin F is reduced. The changes in the prostaglandin content of a compensatory character disappear with the development of hypertensive disease. In healthy persons taking salt in excess, the reaction to the furosemid infusion was directed at providing maximum diuresis and natriuresis; in individuals of the control group it was aimed at arresting excess excretion of sodium and water from the body. In patients with hypertensive disease who took salt in excess, the reaction of prostaglandins to furosemid diminished and was practically absent in patients with a stable arterial pressure level.

[The content of prostaglandins A and E in the blood and renal tissues in the early phase of experimental acute renal failure caused by the crush syndrome]. / Soderzhanie prostaglandinov grupp A i E v krovi i tkaniakh pochek v rannei faze éksperimental'noi ostroi pochechnoi nedostatochnosti, vyzvannoi krash-sindromom.

Prostaglandin (PG) A and E content in the blood and renal tissues (cortex and medulla) has been studied in 25 dogs in the early phase of acute renal failure (ARF). It has been found that by the 4th hour of compression PG content increases drastically in the blood and renal cortex and decreases in the renal medulla. Compression relief and ARF progress were accompanied by a drop in PG concentration both in the blood and the renal cortex and medulla. It is concluded that enhanced PGE2 synthesis is a protective reaction preventing the damage of the renal structure and function. The following decrease in PGE2 level is mediated by progressing effect of aggressive factors on the interstitial cells of the renal medulla and the endothelial cells of the cortex vessels--as a basic source of endogenous PG synthesis. The results obtained are experimental proof of PGE2 use in the complex therapy of ARF.

[State of prostanoid-regulating function of the lungs in patients subjected to thoracic surgery]. / Sostoianie prostanoidreguliruiushchei funktsii legkikh u bol'nykh pri torakal'nykh operatsiiakh.

Lung capacity to regulate the level of plasma prostanoids at the expense of their destruction or extra synthesis is one of their numerous non-gas-exchange functions. Prostaglandins A, E, and F, prostacyclin, and thromboxane were measured in the arterial and venous blood of 23 patients before and after surgery. The level of prostanoids was sharply increased in surgical patients. Substrates with the broncho- and vasoconstrictive action predominate in the blood of patients with obstructive and restrictive changes in the lungs, this eventually leading to complications in the postoperative period.

High levels of interleukin-6 and 8-iso-prostaglandin in the exhaled breath condensate and serum of patients with chronic obstructive pulmonary disease related pulmonary hypertension.

BACKGROUND: Pulmonary hypertension (PH) is a common complication of chronic obstructive pulmonary disease (COPD). Although alveolar hypoxia is considered as a main cause of PH in COPD, structural and functional changes of pulmonary circulation are apparent at the initial stage of COPD. We hypothesized that an inflammatory response and oxidative stress might contribute to the formation of PH in COPD. METHODS: We measured the levels of interleukin-6 (IL-6) and 8-iso-prostaglandin (8-iso-PSG) in exhaled breath condensate (EBC) and serum in 40 patients with COPD only or in 45 patients with COPD combined with PH. Pulmonary arterial systolic pressure (PASP) was assessed by Doppler echocardiography and defined as PH when the value of systolic pressure was greater than 40 mmHg. RESULTS: Compared with the COPD only group, the level of IL-6 in EBC was significantly increased in all 45 patients with COPD combined with PH ((8.27±2.14) ng/L vs. (4.95±1.19) ng/L, P < 0.01). The level of IL-6 in serum was also elevated in patients with COPD combined with PH compared with the COPD only group ((72.8±21.6) ng/L vs. (43.58±13.38) ng/L, P < 0.01). Similarly, we also observed a significant increase in the level of 8-iso-PSG in both EBC and serum in the COPD with PH group, compared with the COPD only group (EBC: (9.00±2.49) ng/L vs. (5.96±2.31) ng/L, P < 0.01 and serum: (41.87±9.75) ng/L vs. (27.79±11.09) ng/L, P < 0.01). Additionally, the value of PASP in the PH group was confirmed to be positively correlated with the increase in the levels of IL-6 and 8-iso-PSG in both EBC and serum (r = 0.477-0.589, P < 0.05). CONCLUSION: The increase in the levels of IL-6 and 8-iso-PSG in EBC and serum correlates with the pathogenesis of PH in COPD.