Nδ-acetylornithine and S-methylcysteine in blood plasma

N^δ-Acetylornithine and S-methylcysteine have been identified as minor components of deproteinized blood plasma of human and bovine blood. Human blood plasma contains a variable amount of acetylornithine, averaging 1.1 ± 0.4 μmol/l (range 0.8–0.2 μmol/l). Urine contains a very small amount of acetylornithine, approximately 1 nmol/mg creatinine (1 μmol/day). Human blood plasma contains 3.9 ± 1.9 μmol/l (range 1.4–6.5 μmol/l) of S-methylcysteine. Urine contains approximately 5 nmol/mg creatinine; after acid hydrolysis the amount is increased to 20 nmol/mg creatinine.     

The influence of citrate, EDTA, and heparin anticoagulants to human plasma LC–MS lipidomic profiling

Lipid profiling of human plasma by liquid chromatography-electrospray ionization coupled to mass spectrometry (LC–ESI-MS) is being used to identify biomarkers of health, disease, and treatment efficacy. However, there is no consensus on the choice of anticoagulant to perform and compare lipidomic measurements. This study assessed the effect of the anticoagulants citrate, EDTA, and heparin, on eight synthetic and 80 plasma lipids, and compared lipidomic data among anticoagulants. Lipid extraction was affected distinctively by the anticoagulant of choice likely due to the different physico-chemical properties among anticoagulants. Peak areas of seventy endogenous lipids showed significant differences between citrate–heparin and EDTA–heparin comparisons similar to those observed for synthetic lipids. Only ten endogenous lipid species showed comparable peak areas among the three anticoagulants. Correction by a structurally related internal standard only partly eliminated differences among anticoagulants (ANOVA, P value <0.001). However, comparisons among anticoagulants were possible for most endogenous lipids after correction of peak areas by the sum of areas of its lipid class. Our observations indicate that the choice of anticoagulant distinctively impact the peak response of most lipid species by LC–ESI-MS. Lipidomic data from plasma obtained with different anticoagulants should address differences in matrix effects and extraction procedures since ion strength, plasma pH, and different physicochemical properties among anticoagulants influence lipid extraction and LC–ESI-MS analysis.     

Photochemiluminescent detection of antiradical activity; IV: testing of lipid-soluble antioxidants

A new method for quantification of antiradical properties of pure lipid-soluble antioxidants and for measurement of integral antioxidant capacity in the lipid phase (ACL) of polycomponent systems, such as blood plasma or tissue homogenates, is developed. It is based on an antioxidant-sensitive inhibition of a photo-induced, chemiluminescence accompanied autoxidation of luminol. The sensitivity of the photochemiluminescent (PCL) assay lies within nmol quantities of substances, the measuring range for α-tocopherol is between 0.1 and 3 nmol. The interassay variability of the method is lower than 5%, the intraassay variability <2%. The antioxidant efficiency of γ-tocopherol was found to be 43% of α-tocopherol. The results of the PCL measurements on pure antioxidants and on lipid extracts from blood plasma were compared with the level of, ‘vitamin E’ (VE) determined as a sum of α- and γ-tocopherol by HPLC. Very good coincidence of both methods was observed for pure substances (r = 0.998, P<0.001). The ACL of human blood plasma was found to be 27.98 ± 0.68 μmol equivalents of α-tocopherol/l (mean ± mean error, n = 142), it is ∼ 25% more than the concentration of VE found in the same samples (22.09 ± 0.59 μmol/l). In this case, the correlation of both parameters was lower: r = 0.811, P<0.001. The animal experiments showed that synthetic antioxidants may not only increase the value of ACL of blood plasma but in the same time reduce the concentration of biological antioxidants, e.g. VE drastically. The prooxidant activity of synthetic antioxidants in vivo or the replacing of structured α-tocopherol from its position can be the cause. This important circumstance has to be considered during the testing of new antioxidants for clinical application.     

Stereoselective binding of isradipine to human plasma proteins

Isradipine (PN 200–110) is a highly potent calcium entry blocker with an asymmetrically substituted dihydropyridine ring (methyl- and isopropylester, respectively). The binding of the (+)-(S)-isradipine and (?)-(R)-isradipine to isolated human serum albumin (HSA, 30 μmol/l) and α₁-acid glycoprotein (AAG, 10 μmol/l) has been studied in vitro over a wide range of isradipine concentrations (0.06–20 μmol/l) using high-performance liquid chromatography (HPLC). HPLC experiments revealed that both isradipine enantiomers were bound to one class of high-affinity binding sites on the AAG molecule (n_(S) = 0.83 ± 0.05, K_a(S) = (1.33 ± 0.25) × 10⁶ 1/mol, n_(R) = 0.85 ± 0.07, K_a(R) = (1.17 ± 0.44) × 10⁷ l/mol). The (R)-enantiomer also exhibited an interaction with the secondary low-affinity binding sites (n′K′_{a (R)} = (2.66 ± 0.65) × 10⁴ l/mol). In contrast, the pharmacologically more potent (+)-(S)-enantiomer was more strongly bound to HSA than its optical antipode (n_(S) = 1.07 ± 0.07, K_a(S) = (1.76 ± 0.26) × 10⁵ l/mol, nK_a(R) = (3.62 ± 0.06) × 10⁴ l/mol). In general, the resulting binding characteristics of individual isradipine enantiomers showed stereoselectivity, but this was opposite for the two most important plasma binding proteins. The process of accumulation of isradipine by human platelets in the therapeutically relevant range (10–80 ng/ml) at 37°C was devoid of stereoselectivity. © 1995 Wiley-Liss, Inc.     

Serum selenium levels in Slovak population

Blood serum selenium levels were measured in 576 healthy middle aged adults (40–60 yr, 255 men and 321 women) residing in both urban and rural areas in four districts of Slovakia. Serum selenium was determined by electrothermal AAS. The mean (±SD) serum selenium concentration was 0.852±0.335 μmol/L, ranging from 0.219–2.30 μmol/L. A large proportion of the individuals (19.62%) exhibited serum selenium levels under 0.57 μmol/L (45 μmol/L). There was no significant correlation between serum, selenium concentration and age, sex, and smoking status. There were significant differences between districts. The lowest mean (±SD) serum selenium was 0.664±0.269 μmol/L, the highest mean serum selenium (±SD) was 0.975±0.361 μmol/L. This differences could probably be attributed to the selenium, content in the soil of the different areas, which would contribute to the average daily selenium intake. In comparison with serum selenium levels in other European countries, the concentrations of selenium in the Slovak population are relatively low.     

Plasma coenzyme Q10 concentrations are not decreased in male patients with coronary atherosclerosis

Coenzyme Q₁₀ (CoQ₁₀) is an important mitochondrial electron transfer component and has been postulated to function as a powerful antioxidant protecting LDL from oxidative damage. It could thus reduce the risk of cardiovascular disease. Thus far, beneficial effects of supplementation with CoQ₁₀ have been reported. To study the relation between unsupplemented concentrations of plasma CoQ₁₀ and coronary atherosclerosis, we performed a case-control study among 71 male cases with angiographically documented severe coronary atherosclerosis and 69 healthy male controls free from symptomatic cardiovascular disease and without atherosclerotic plaques in the carotid artery.

Plasma CoQ₁₀ concentrations (mean ± SE) were 0.86 ± 0.04 vs. 0.83 ± 0.04 μmol/l for cases and controls, respectively. The CoQ₁₀/LDL-cholesterol ratio (μmol/mmol) was slightly lower in cases than in controls (0.22 ± 0.01 vs. 0.26 ± 0.03). Differences in CoQ₁₀ concentrations and CoQ₁₀/LDL-cholesterol ratio did not reach significance. The odds ratios (95% confidence interval) for the risk of coronary atherosclerosis calculated per μmol/l increase of CoQ₁₀ was 1.12 (0.28–4.43) after adjustment for age, smoking habits, total cholesterol and diastolic blood pressure.

We conclude that an unsupplemented plasma CoQ₁₀ concentration is not related to risk of coronary atherosclerosis.     

Total bile acids in hyperlipidaemic serum determined by bioluminescent and spectrophotometric methods

A simple, rapid and sensitive bioluminescent method has been used to measure total bile acids in hyperlipidaemic serum. We found that the levels of total bile acids in hypertriglyceridaemic and hypercholesterolemic sera determined by a spectrophotometric method were four-fold higher than those measured by the bioluminescent method (6.73 ± 4.07 μmol/l (mean ± SD) by bioluminescent and 26.10 ± 13.42 μmol/l by the spectrophotometric method). There was no difference in total bile acid levels between these two methods for normal serum (4.72 ± 3.38 μmol/l by bioluminescence and 4.49 ± 3.27 μmol/l by the spectrophotometric method).     

Assessment of the Zinc and Copper Status in Alpaca

This study was performed with the aim of investigating the concentration of zinc and copper in the blood of healthy alpacas (Vicugna pacos) kept in central Europe and to compare the concentration of Zn and Cu in plasma and in whole blood. A further objective was to evaluate blood Zn and Cu in relation to different micromineral supplementation, age and sex groups of alpacas. A total of 299 alpacas (224 adults and 75 crias) from 18 farms were included in this study. The concentrations of copper and zinc in plasma/whole blood were measured by flame atomic absorption spectrometry. The results of this study show high individual variability in plasma Zn (median 3.54, range 1.56–8.01 μmol/l), whole blood Zn (median 10.01, range 6.23–75.0 μmol/l), plasma Cu (median 7.53, range 2.93–16.41 μmol/l) and whole blood Cu (median 6.33, range 3.02–13.95 μmol/l). Plasma Zn was not significantly influenced by sex, age or feeding group. Whole blood Zn was only significantly higher in females than in males. The intake of Zn in all groups was equal to or higher than the nutritional recommendation. During excessive supplementation, Zn absorption decreased and thus blood Zn did not reflect the higher intake. Only a weak correlation was found (Spearman correlation coefficient r = 0.384; p > 0.01; n = 204) between plasma and whole blood Zn concentrations. Plasma copper concentration was significantly influenced by age, sex and feeding; whole blood Cu by age and feeding. However, neither plasma Cu nor whole blood Cu reflected the intake of the element. We found a close correlation between plasma and blood copper concentrations (Spearman correlation coefficient r = 0.9043; p ≤ 0.01; n = 99). According to our results, copper in plasma or blood is not a good indicator of copper intake.     

Fine structure and motility of spermatozoa and composition of the seminal plasma in the perch

The fine structure and motility of spermatozoa and the composition of the seminal plasma of the perch Perca fluviatilis are investigated by electron microscopy, computer assisted cell motility analysis (CMA) and biochemical methods. The spermatozoon is asymmetrical as the flagellum inserts mediolateral on the nucleus. It lacks an acrosome, has an ovoid head and a small midpiece with one mitochondrion. Sperm motility–initiated in distilled water (10° C)–is characterized as follows: 85·0 ± 2·7% of the spermatozoa are motile, the main swimming type (10 ± 1 s after motility initiation) is the linear motion (61·4 ± 24·4%) and the average swimming velocity is 122·4 ± 21·9 μm s^–1. When motility is initiated with NaCl, glucose or sucrose solutions of 100 mosmol kg^–1 the percentage of motile spermatozoa and the swimming types are similar as in water, but the swimming velocity (174·0 ± 22·3 μm s^–1) is significantly higher. Motility is inhibited by high osmolality of the diluent: when increasing the osmolality of the saline solutions to 350 mosmol kg^–1 sperm motility is totally suppressed while potassium (10–40 mmol 1^–1) does not affect motility parameters. pH optimum for sperm motility is between pH 7·0 and 8·5. The seminal fluid contains 124·01 ± 21·68 mmol 1^–1 sodium, 10·22 ± 1·11 mmol 1^–1 potassium and 0·72 ± 0·26 mmol 1^–1 calcium. pH is 8·25 ± 0·09, and osmolality 283·90 ± 37·19 mosmol kg^–1. The following organic components were determined: monosaccharides (glucose 63 ± 19 μmol 1^–1, fructose 54 ± 28 μmol 1^–1, galactose 59 ± 25 μmol 1^–1), lipids (cholesterol 5·51 ± 6·42 μmol 1^–1, triglycerides 72 ± l00 μmol l^–1, cholesteryloleate 15–150 μmol 1^–1, phosphatidylcholine 26 · 31 μmol 1^–1, glycolipids 1–10 mg 100 m1^–1), lactate 108 ± 99 μmol 1^–1, hydroxybutyrate 102 ± 99 nmol 1^–1, choline 59 ± 159 μmol 1^–1, protein 344·75 ± 59·06 mg 100m1^–1, enzymes (β-d -glucuronidase l.4 ± 0.7 μmol h^–1 100 ml^–1, protease (caseolytic activity) 1·0 ± 0·6 μmol h^–1 100 ml^–1, alkaline phosphatase 2520·0 ± 861·0 μmol h^–1 100 ml^–1, acid phosphatase 44.0 ± 16.0 μmol h^–1 100 ml^–1, glucose-6-phosphate dehydrogenase 38·9 ± 86·9 μmol h^–1 100 ml^–1, lactate dehydrogenase 134·4 ± 69·6 μmol h^–1 100 ml^–1, butyrylcholine esterase 0·014 ± 0·010 μmol h^–1 100 ml^–1, adenosine triphosphatase 562·8 ± 665·4 μmol h ^–1 100 ml^–1).     

Elevated Levels of Lead in Blood of Different Groups in the Urban Population of Enugu State,Nigeria

Two hundred and forty blood samples were collected from children, women, and men in urban areas of Enugu State, Nigeria. The samples were analyzed for lead by atomic absorption spectrophotometry. Results show the range and % detectable values were 3.9–88.1 μg/dl and 97.92%, respectively. The sample population was classified according to age groups (≤12, 13–25, and >25 years), sex, occupationally and non-occupationally exposed, pregnant women/nursing mothers and other women, and those exposed/or not exposed to some possible risk factors. This was done to find out if there is a trend within the different categories, which will help in identifying toxicity risk groups of lead in Nigeria. Children had the highest range of blood lead levels (12–88 μg/dl), with a mean level of 48.8 μg/dl. Males showed a higher mean concentration for lead than did the women in our study, while pregnant women/nursing mothers had a lower mean concentration (28.8 ± 19.8 μg/dl) of lead than the other women (32.8 ± 12 μg/dl). There was significant difference between the responses for some of the factors, showing that concentrations of lead are affected by these factors. The generally polluted environment probably has had significant impact on the lead blood burden of the Nigerian population.     

Inter- and intra-individual variation in plasma and red blood cell vitamin E after supplementation

To establish the range of individual blood responses to supplemental vitamin E, 30 healthy subjects ingested 75 mg of deuterium-labelled α-tocopherol with a standard breakfast. Blood was collected at 6, 9, 12, 27 and 51 h post ingestion and deuterated (d₆) and non-deuterated (d₀) α-tocopherol concentrations were determined in plasma and red blood cells (RBC) by GC-MS. To examine intra-individual responses, 6 of these subjects were re-examined at 6-month intervals over a 30-month period. Post ingestion, the amount of d₆-α-tocopherol in blood increased rapidly with time with maximal concentrations seen at 12 h (plasma) and 27 h (RBC) in most subjects. At these times, d₆-α-tocopherol concentration ranged from 0.3–12.4 μmol/l in plasma and 0.6–4.09 μmol/l packed cell in RBC. Area under the curve calculations indicated inter-individual differences of α-tocopherol uptake to be 40-fold for plasma (12.9–493.3 μmol h/l) and 6-fold for RBC (24.4–146.1 μmol h/l packed RBC). Intra-individual variation in α-tocopherol uptake was small in comparison and remained relatively constant over the 30-month period. We conclude that vitamin E uptake varies widely in the normal population, although it is comparatively stable for an individual over time. These differences likely arise from variations in the regulation of vitamin E uptake and metabolism between subjects. Factors regulating this process must be better understood before the optimal intake of vitamin E can be ascertained.     

Short-term parenteral application of α-tocopherol leads to increased concentration in plasma and tissues of the rat

Numerous studies suggest that supplemental vitamin E prior to or during vast surgeries might diminish or even prevent ischemia/reperfusion-induced injuries. In the present placebo-controlled study male Sprague-Dawley rats were supplemented parenterally or orally with α-tocopherol for three consecutive days. The applied amount of α-tocopherol was 2.3 μmol per day for oral and 1.2 μmol per day for parenteral supplementation. The enrichment of vitamin E concentrations in plasma and tissue samples (aortic endothelium, liver, and lung) was determined by HPLC. The vitamin E level was elevated following intravenous supplementation in plasma (21.4±1.9 μmol/L vs. 10.2±1.7 μmol/L in parenteral control group), in aortic endothelium (1.1±0.2 pmol/mm² vs. 0.5±0.1 pmol/mm²) and in liver and lung (41.3±7.5 pmol/mg vs. 22.9±6.5 pmol/mg and 75.6±13.6 pmol/mg vs. 51.7±5.9 pmol/mg, respectively). Oral supplementation for three days also led to an increased level in liver (38.2±7.7 pmol/mg vs. 22.9±6.6 pmol/mg in oral control group) and in lung (67.8±5.7 pmol/mg vs. 51.7±9.3 pmol/mg) but not in aortic endothelium or plasma (0.8±0.3 pmol/mm² vs. 0.6±0.3 pmol/mm² and 12.0±2.2 μmol/L vs. 10.7±2.6 μol/L.)     

Relationships among spermatozoal abnormalities and the selenium concentration of blood plasma,semen, and reproductive tissues in young bulls

The concentration of selenium (Se) was measured by instrumental neutron activation analysis in samples of blood plasma, semen, and reproductive and non-reproductive tissues obtained from each of 12 young bulls (8 Angus and 4 Simmental). Semen was collected by electro-ejaculation and used for measurements of the frequency of primary and secondary spermatozoal abnormalities. The mean Se concentration (μg/ml) of semen (± SD) was 0.461 (±0.223) compared to 0.061 (±0.014) for blood plasma. Tissue from the testis, caput epididymis and cauda epididymis had mean Se concentrations of from 2.5 to 2.7 μg/g compared to less than 1.8 μg/g in all other tissues except the pituitary gland (3.4 μg/g) and kidney cortex (6.9 μg/g).Correlations of the proportional incidence of spermatozoal abnormalities with Se concentrations in reproductive tissues, semen or blood plasma were low. Although Se may be concentrated in the testis and epididymis, the Se concentration was not related to spermatozoal abnormalities.     

Determination of vitamin A in dried human blood spots by high-performance capillary electrophoresis with laser-excited fluorescence detection

We have developed a high-performance capillary electrophoresis (HPCE) method to analyze the retinol (vitamin A) concentration as retinol-retinol binding protein (holo-RBP) from microvolumes of serum (5–10 μl) or one to two drops (∼20 μl) of blood collected and air-dried on blood collection filter paper. A 0.64-cm diameter disk was cut from the dried whole blood specimens and the samples were dissolved in a pretreatment buffer and filtered. Filtrate was injected onto the HPCE column for analysis. The separation was carried out in a 60 cm × 50 μm I.D. fused-silica capillary and the running voltage was 20 kV. A HeCd laser with a wavelength of 325 nm was used for excitation, and the fluorescence of the holo-RBP complex was monitored at 465 nm by a photodiode. A virtual linear relationship was obtained for the retinol concentrations between HPCE and HPLC for 28 serum samples, 19 dried venous blood samples and 9 capillary dried blood spot samples, indicating that valid measures of serum retinol can be obtained from one to two drops of capillary blood collected on filter paper. The absolute detection limit for retinol by HPCE is below 3 μg/l. The method is very useful for vitamin A level screening, especially for children and premature new-born babies.     

Total plasma homocysteine determination by liquid chromatography before and after methionine loading: Results in cerebrovascular disease

Elevated homocysteine (HCY) levels in tissues and blood are associated with premature occlusive diseases. A number of techniques have been developed to assay HCY, including high-performance liquid chromatography (HPLC) with fluorimetric or electrochemical detection, and radioenzymatic methods. The present study evaluated the adaptation of a liquid chromatographic, ion-exchange technique with postcolumn derivatization using ninhydrin. Fasting and moreover post-methionine load total plasma HCY were assayed in 50 patients three months after a stroke and in 20 age-matched controls. Ion-exchange liquid chromatography was performed on an amino acid analyzer using a modified procedure to improve methionine and HCY separation. HCY values in the fasting state were moderately but significantly increased (P<0.05) in the patients compared to the controls: 10.5±3.4 versus 9.3±2.3 μmol/l. The difference between the two groups was amplified in post-load HCY results, which were significantly increased (P<0.05) in the patients: 41.6±17.8 versus 29.2±5.5 μmol/l in controls. The relationship between cerebrovascular disease and impaired HCY metabolism has previously been emphasized by other investigators. Our findings suggest that certain inherited and/or acquired HCY disorders observed in the fasting state (14%) and especially in post-methionine load conditions (32%) may occur during acute disease, and that total plasma HCY can be determined by ion-exchange chromatography even after oral methionine loading.     

Ultrafiltration-light absorption spectrophotometric determination of silicon in blood

An ultrafiltration-light absorption spectrometric method for soluble molybdate-reactive silicon was assessed and applied to bovine and ovine blood plasma and sera, giving precise analytical results. Interfering protein above molecular weight 10,000–25,000 was removed by ultrafiltration, and silicon in ultrafiltrates was quantitated by measuring light absorption at 810 nm of the 1,2,4-aminonaphthol sulfonic acid/ascorbic acid-reduced silicomolybdate. Chemical interferences on the color-forming reaction of remaining blood components were tested by measuring recoveries of silicon added to real blood plasma samples and to synthetic blood plasma solutions, the latter containing typical levels of the major ions Na⁺, K⁺, Ca²⁺, HCO₃^?, and Cl^?, together with varying quantities of the potential interferants (amount per analytical reaction): phosphate (0–0.5 mg P), ferric ion (0–3 mg), fluoride (0–1.25 mg), vanadate (0–0.5 mg V), arsenate (0–10 μg As), and germanate (0–0.5 μg Ge). The mean recovery of added 0.8–9 μg silicon/g of bovine and ovine plasma was 97.7% (SE = 1.0, n = 17); the mean recovery of 1 and 5 μg silicon from synthetic blood plasma solutions with interferant levels up to 50-fold that in normal plasma was 99.2% (SE = 0.3, n = 47). Silicon concentrations found in bovine and ovine blood plasma and sera were typically around 7 μg/ml with procedural reagent blanks consistently low at a mean of 0.12 μg/test (SD = 0.011, n = 20). The silicon level in Center for Disease Control bovine serum (reference specimen Lot R-2274) was found to be (mean ± SE, n = 10) 1.147 ± 0.013 μg/g or 1.172 ± 0.013 μg/ml (25°C). The method detectivity (detection limit) was estimated at 0.03 μg.     

Biological variation of ascorbic acid and α-tocopherol

Accumulating evidence that free radicals may contribute to various diseases, has sparked epidemiological and experimental studies of the correlation between plasma levels of antioxidant vitamins and risk to develop cancer, ischaemic heart disease and stroke. These studies often do not take into account the random biological fluctuation of the antioxidant concentration, which occurs in each individual. The weekly and monthly variability of the antioxidants ascorbic acid and α-tocopherol was studied in 12 healthy volunteers (4 women and 8 men) aged 23–45 years. Vitamin levels were determined using high performance liquid chromatography. Over 12 weeks the mean plasma concentration of ascorbic acid was 42± 12 μmol/I and of α-tocopherol was 31±3 μmol/I. The intraindividual coefficients of variation (estimated using analysis of variance techniques) were 26% (ascorbic acid) and 12% (α-tocopherol). The analytical goal for imprecision was achieved for both vitamins, i.e. it was less than one-half of the measured intraindividual variation. Both antioxidants showed marked individuality, indicating that an individual's reference values are more useful than population-based data. The critical difference required for significance of changes in serial results is smaller for α-tocopherol (34%) than that for ascorbic acid (72%).     

The effects of anticoagulants on hematological indices and blood cell morphology of common carp (Cyprinus carpio L.)

Hematological parameters (Ht, Hb, RBC, WBC, PLT), erythrocyte size, and osmotic fragility, differential leukocyte count, ROS production in common carp blood collected on three anticoagulants: heparin (10 IU/mL, Na2EDTA (0.1, 0.5, and 1 mg/mL), and sodium citrate (0.3 mg/mL) were compared. Na2EDTA caused partial blood hemolysis in Ht tubes which made Ht measurement impossible, and resulted in high variability of the results. Both, citrate and Na2EDTA increased sensitivity of red blood cells to hemolysis. Na2EDTA also induced erythrocyte anisocytosis and anisonucleosis. Na2EDTA significantly increased ROS production but no effect of anticoagulants on WBC, PLT or differential leukocyte count was observed. The obtained results show that Na2EDTA should not be used for evaluation of red blood cell parameters and erythrocyte morphology, and for ROS production measurement in common carp. Heparin proved to be the most appropriate anticoagulant to use for this species, although Na2EDTA and sodium citrate may be used for WBC and leukocyte differential count evaluations.     

Green-blood pigmentation in lizards

The green pigment in the plasma of the scincid lizard genus Prasinohaema is identified as the bile pigment biliverdin. Concentrations of biliverdin in the plasma of P. flavipes, P. prehensicauda and P. virens are 714 ± 79 μmol/1 (mean ± one standard deviation), 1020 ± 624 μmol/1 and 819 ± 89 μmol/1, respectively. These values represent the highest concentration of plasma biliverdin measured for any organism and are the first report of non-pathological biliverdin accumulation in amniotes. We review the literature for fish species with high concentrations of plasma biliverdin and pathological biliverdin accumulation in humans; we find that Prasinohaema species have plasma biliverdin concentrations approximately 1.5–30 times greater than fish species with green blood plasma and 40 times greater than humans with green jaundice.     

Sensitive assay for measuring amoxicillin in human plasma and middle ear fluid using solid-phase extraction and reversed-phase high-performance liquid chromatography

We developed a sensitive assay to measure amoxicillin in human plasma and midle ear fluid (MEF) using solid-phase extraction and reversed-phase HPLC. Amoxicillin and cefadroxil, the internal standard, were extracted from 50–200 μl of sample with Bond Elut C₁₈ cartridges. The exact was analyzed on a 15 cm × 2 mm, 5μm Keystone MOS Hypersil-1 (C₈) column with UV detection at 210 nm. The mobile phase was 6% acetonitrile in 5 mM phosphate buffer (pH = 6.5) and 5 mM tetrabutylammonium. The average absolute recovery of amoxicillin and cefadroxil were 91.2 ± 16.6% and 91.0 ± 6.8%, respectively. The limit of quantitation was 0.125 μg/ml with 200 μl sample size. The linear range was from 0.125 to 35.0 μg/ml with correlation coefficients greater than 0.999. These analytic conditions produced a highly sensitive amoxicillin assay in human body fluids without derivatization.