New direct assay of free protein S antigen applied to diagnosis of protein S deficiency

Congenital deficiencies of protein S (PS) are associated with thrombophilia. Their characterization and classification have been hampered by the complex physiology of the protein C-protein S system and the poor standardization and reliability of laboratory assays. The free active form of protein S is usually determined by immunoassay using polyclonal antibodies in the plasma supernate after polyethyleneglycol (PEG) precipitation. A new one step ELISA using two monoclonal antibodies specific for distinct epitopes of the free form of protein S has been developed for the direct measurement of free PS in untreated plasma. We have tested two ELISA assays for free PS. One assay was based on the PEG precipitation (Asserachrom PS, Stago, Asnières, France) whereas the other was a one step ELISA assay (Asserachrom free PS, Stago). Values were obtained in 35 PS deficient patients recruited among 500 consecutive patients evaluated by the laboratory for diagnosis of congenital disorders of coagulation. Values were compared to those obtained in 50 patients with no PS deficiency matched for age and sex with the PS deficient patients as well as in 33 normal subjects and in 12 pregnant women. Strong correlation was found between the two tests (r = 0.81, p < 10(-5)) in the entire population (n = 130), as well as in the separate groups. The new one step ELISA was more accurate than the PEG free PS determination. Determination of PS activity and antigens allowed us to separate quantitative and qualitative deficiencies. Among the qualitative deficiencies, isolated decrease in PS activity was the most frequent defect observed (66%). This fact questions the substitution of PS activity assays by the one step antigenic free PS ELISA assay.     

Radioimmunoassay for the testosterone 5 alpha-reductase inhibitor turosteride in biological fluids

An antiserum against turosteride (code name FCE 26073), a potent testosterone 5 alpha-reductase inhibitor, has been raised in rabbits by immunization with an immunogen produced by conjugation of a derivative of FCE 26073 (FCE 27424) to bovine serum albumin. The antiserum was able to distinguish FCE 26073 from its derivatives modified at the 17 beta position and from all the endogenous steroids tested. A radioimmunoassay for the determination of FCE 26073 in human plasma and urine was developed using this antiserum and tritium labeled turosteride. FCE 26073 was extracted from 50 microliters of plasma or 25 microliters of urine using ethyl-ether with a recovery greater than 90%. Using this procedure it was possible to achieve a final limit of quantitation of 142 pg/ml in plasma and 284 pg/ml in urine. The assay was validated in terms of reproducibility, accuracy and precision in the range 3.9-250 pg/50 microliters of plasma and 25 microliters of urine. The plasma concentration of FCE 26073 in a healthy male volunteer who received 0.2 mg of the drug was measured using the radioimmunoassay.     

沙利度胺治疗急性白血病的疗效及对血管调控因子水平的影响

目的 观察沙利度胺联合化疗治疗急性白血病的临床疗效及其对血浆血管内皮生长因子(VEGF)、血管内皮生长因子受体(VEGFR)、碱性成纤维细胞生长因子(bFGF)水平的影响.方法 急性白血病患者36例,随机分为试验组及对照组各18例.每组均予以常规化疗方案标准剂量化疗,试验组同时口服沙利度胺100 mg/d.治疗前及治疗后8周分别采集外周血,双抗体夹心酶联免疫吸附法(ELISA)检测血浆VEGF、VEGFR、bFGF含量.以15位健康体检者为健康对照组.结果 试验组与对照组有效率分别为88.9%(16/18)和77.8%(14/18),差异有统计学意义(x2=4.103,P＜0.05).试验组与对照组治疗前血浆VEGF水平分别为(389.78±249.94)和(318.54±125.78)pg/ml,高于健康组的(132.91±26.66)pg/ml(t=3.141、3.024,均P＜0.01);治疗后分别为(211.74±36.72)和(288.02±31.77)pg/ml,高于健康组(t=2.413、2.324,均P＜0.05);试验组与对照组治疗前VEGF差异无统计学意义(t=1.384,P＞0.05),治疗后差异有统计学意义(t=2.793,P＜0.05).试验组与对照组治疗前血浆VEGFR水平分别为(2490.75±1695.9)和(2322.78±1105.87)pg/ml,高于健康组的(1134.98±378.45)pg/ml(t=2.914、2.783,均P＜0.01);治疗后分别为(1359.71±390.24)和(1753.89±337.04)pg/ml,与健康组相比差异有统计学意义(t=2.572、2.447,均P＜0.05);试验组与对照组治疗前VEGFR差异无统计学意义(t=1.276,P＞0.05),治疗后差异有统计学意义(t=2.486,P＜0.05).试验组与对照组治疗前血浆bFGF水平分别为(2.43±0.27)和(2.4l±0.33)ng/ml,高于健康组的(1.83±0.44)ng/ml(t=4.982、4.171,均P＜0.05);治疗后分别为(2.09±0.17)和(2.11±0.31)ng/ml,与健康组相比差异有统计学意义(t=3.01l、2.773,均P＜0.05);试验组与对照组治疗前及治疗后相比差异无统计学意义(t=0.953、1.282,均P＞0.05).结论 沙利度胺联合化疗可提高急性白血病患者的缓解率,有可能成为一种通过抗血管新生从而抑制白血病细胞生长及浸润的有效治疗方法.     

Behavior of plasma levels of endothelin 1 and noradrenaline in patients with stable angina during the cold pressor test

The aim of this study was to evaluate the behaviour of plasma endothelin-1 (ET-1) and norepinephrine (NE) levels in patients with stable angina during a sympathetic stimulation test as the cold pressor test. We enrolled in the study 29 subjects: 14 patients with stable angina (all men, mean age 58.3 +/- 7.3 years) and 15 healthy subjects (all men, mean age 54 +/- 5 years). All patients with stable angina had a stenosis of the coronary arteries (at least 70% of the stenosis in one of the coronary arteries) confirmed by angiography. Before (-15 min; 0 min) during (+2 min) and after the cold pressor test (+5 min, +10 min, +20 min, +30 min) were measured the blood pressure and the heart rate. At the same time were collected venous samples for the ET-1 and NE determination. ET-1 levels increased only in the patients with stable angina (ET-1: O' = 9.8 +/- 3.7 pg/ml; +2' = 11.1 +/- 4.5 pg/ml; +10' = 14.8 +/- 7.1 pg/ml; +20' = 11.6 +/- 5.1 pg/ml; p < 0.05 vs 0', +2'; +20'). The NE levels increased in both groups (NE stable angina: 0' = 105 +/- 31 pg/ml; +2' = 206 +/- 127 pg/ml; +5' = 223 +/- 135 pg/ml; p < .05 vs +2', +5'); (NE healthy subjects 0' = 85 +/- 10 pg/ml; +2' 165 +/- 49 pg/ml; p < 0.05 vs + 2'). In conclusion, our study showed that cold pressor test is a stimulus for the sympathetic system in both groups. The increased levels of ET-1 detected only in the patients with stable angina suggest that this peptide can take part to the pathogenesis of the coronary artery disease.     

Development and validation of a sensitive and specific radioimmunoassay for the determination of cicaprost in biological samples

Cicaprost is a potent, chemically and metabolically stable PGI2-mimetic. Pharmacodynamic effects were observed after oral administration of approximately 10 micrograms in man when plasma levels were in the low pg-range. The present report describes the development of a selective antiserum and a tracer with high specific activity and their use for the RIA determination of Cicaprost in biological samples. Cicaprost-[3H]-methylester with a specific activity of 819 GBq/mmol was used as a tracer. RIA-analyses were carried out with 0.05-0.5 ml plasma adjusted to pH 2 with 1 N HCl and extracted with 2.5 ml diethylether. Separation of antiserum bound and unbound Cicaprost was achieved by the charcoal method. Extraction recovery of Cicaprost was approximately 90% at pH approximately 2. The detection limit of the assay was 10-20 pg/ml plasma. Coefficients of variations were 6, 3 and 9% (within-day, n = 5) and 25, 12 and 10% (day-to-day, n = 11) at 50, 100 and 200 pg/ml. HPLC-chromatograms of plasma extracts did not reveal any peak apart from Cicaprost, demonstrating the specificity of the method. The present RIA for Cicaprost exhibits high specificity and sensitivity and will be used for further bioanalyses in pharmacokinetic study.     

Purification of cytochrome b5 from pig testis microsomes by isoelectric focusing in an immobiline pH gradient

To evaluate the diagnostic value of thrombopoietin (TPO, c-mpl ligand) measurements, and clarify the regulatory mechanisms of TPO in normal and in thrombocytopenic conditions, the plasma TPO concentration was determined in normal individuals (n = 20), umbilical cord blood (n = 40), chronic idiopathic thrombocytopenic purpura (ITP; n = 16), in severe aplastic anaemia (SAA; n = 3), chemotherapy-induced bone marrow hypoplasia (n = 10), myelodysplastic syndrome (MDS; n = 11), and sequentially during peripheral blood progenitor cell transplantation (n = 7). A commercially available ELISA and EDTA-plasma samples were used for the analysis. The plasma TPO concentration in the normals and umbilical cord blood were 52 +/- 12 pg/ml and 66 +/- 12 pg/ml, respectively. The corresponding values in patients with SAA and chemotherapy-induced bone marrow hypoplasia were 1514 +/- 336 pg/ml and 1950 +/- 1684 pg/ml, respectively, and the TPO concentration, measured sequentially after myeloablative chemotherapy and peripheral blood progenitor cell transplantation, was inversely related to the platelet count. In contrast, the plasma TPO recorded in patients with ITP (64 +/- 20 pg/ml) and MDS (68 +/- 23 pg/ml) were only slightly higher than normal levels. In conclusion, TPO levels were significantly elevated in patients in which bone marrow megakaryocytes and platelets in circulation were markedly reduced, whereas TPO levels were normal in ITP patients, and only slightly increased in the MDS patients. These latter patients displayed a preserved number of megakaryocytes in bone marrow biopsies. Our data support the suggestion that megakaryocyte mass affects the plasma TPO concentration. In thrombocytopenic patients a substantially increased plasma TPO implies deficient megakaryocyte numbers. However, TPO measurements do not distinguish between ITP and thrombocytopenia due to dysmegakaryopoiesis, as seen in MDS patients.     

Relationships between plasma levels of type-II phospholipase A2, PAF-acetylhydrolase, leukotriene B4, complements, endothelin-1, and thrombomodulin in patients with sepsis

We determined the plasma levels of type-II phospholipase A2 (type II PLA2), platelet-activating factor acetylhydrolase (PAFAH) leukotriene B4 (LTB4) and of several complements (C3a, C4a, and C5a), which are considered to be among the cytokines and eicosanoids involved in vascular endothelial disorders and that vary in concentration during sepsis. We investigated the relationship between those levels and those of ET-1 and TM levels in plasma. Plasma levels of type II PLA2, PAFAH, LTB4, C3a, C4a, ET-1, and TM at the time that sepsis was diagnosed in 30 patients were 218.3 +/- 179.9 ng/ml, 23.92 +/- 9.66 nmol/min/ml, 90.35 +/- 31.49 pg/ml, 838.73 +/- 2.30 pg/ml, 1951.46 +/- 1697.78 pg/ml, 6.98 +/- 4.08 pg/ml and 7.80 +/- 3.34 ng/ml, respectively. The C5a plasma level was below the limit of detection in all cases. There were significant correlations between type II PLA2 and ET-1 plasma levels (r = 0.39, p = 0.032) and C3a and ET-1 plasma levels (r = 0.60, p = 0.03). There were also significant correlations between type II PLA2 and TM levels in plasma (r = 0.76, p = 0.0017), PAFAH and TM plasma levels (r = 0.53, p = 0.037), LTB4 and TM plasma levels (r = 0.46, p = 0.016) and C4a and TM plasma levels (r = 0.58, p = 0.037). Results suggest that the elevation of type II PLA2, PAFAH, LTB4 and complement in plasma is involved in vascular endothelial disorders in patients with sepsis.     

Ambulatory sports in asthma improves physical fitness and reduces asthma-induced hospital stay

BACKGROUND: Prevention of posttransfusion non-A,non-B hepatitis in recipients of blood components improved considerably with the introduction of the second-generation of hepatitis C virus (HCV) antibody tests. In 1993, third-generation HCV antibody assays were introduced in Europe. STUDY DESIGN AND METHODS: The performance of three generations of anti-HCV enzyme-linked immunosorbent assay (ELISA) (ELISA-1, -2, -3) was compared in routine blood donor screening (99,394 donations were tested with ELISA-1, 167,999 donations with ELISA-2, and 262,090 donations with ELISA-3) and in serial samples from nine patients with documented acute posttransfusion HCV infection. RESULTS: Eight (0.01%) repeat donors, previously negative in ELISA-1, were found positive in ELISA-2 and were confirmed as positive in second-generation recombinant immunoblot assay and/or cDNA polymerase chain reaction. In the donor population, no difference in the sensitivity of ELISA-2 and -3 was observed. The specificity of the three generations of ELISAs was comparable (99.8, 99.7, and 99.7%). In seroconversion samples, ELISA-2 and -3 detected HCV antibodies at the same time in seven patients, but in two patients, ELISA-3 found HCV antibodies, respectively, 63 and 77 days earlier than ELISA-2 did. In the seroconversion samples, ELISA-2 and -3 were significantly more sensitive than second- and third-generation recombinant immunoblot assays. CONCLUSION: ELISA-3 did not detect more HCV-infected individuals in a donor population that previously tested negative in ELISA-2, but it did detect HCV antibodies earlier in some patients with acute HCV infection. ELISA-2 and -3 were significantly more sensitive than second- and third-generation recombinant immunoblot assays.     

Appearance of granulocyte-macrophage colony-stimulating factor activity at allergen-challenged cutaneous late-phase reaction sites

The cytokines IL-3 and granulocyte-macrophage CSF (GM-CSF) activate and/or prime monocytes, basophils, and eosinophils for a number of proinflammatory events in vitro. It was hypothesized that IL-3 and GM-CSF might also participate in the local inflammatory cascades that occur at cutaneous blister sites after Ag challenge in vivo. The M-07e megakaryocytic leukemia cell line, which proliferates in response to IL-3 or GM-CSF, was used to determine whether these cytokines were present in fluids derived after Ag challenge in the cutaneous blister chamber model. Fluids from blister chambers after either Ag (timothy grass, orchard grass, or ragweed) or vehicle control challenge were collected hourly for 12 h from nine patients with allergic rhinitis. Cytokine (IL-3/GM-CSF) activity was modestly elevated at 4 h after Ag challenge compared to control with the median of maximal proliferation 4% (range, 2 to 22%) vs 2% (range, 1 to 14%), respectively (Ag vs control, p < 0.03). Activity peaked at 7 h (Ag = 10%, range 1 to 12%, vs control = 1%, range 1 to 9%, p < 0.02) and then steadily declined. No increase in cytokine activity over control was seen in Ag-challenged nonatopics (n = 5, p = NS), indicating that release did not result from a nonspecific effect of the Ag solution. Neutralization of cytokine bioactivity in pooled late phase reaction (LPR) fluids from h 4 to 12 (n = 5) with anti-IL-3, anti-GM-CSF, or both antisera revealed that the majority of the activity was GM-CSF. To better quantify cytokine levels, pooled LPR fluids prepared from an additional 11 subjects were concentration-dialyzed (10x) and tested for cytokine activity. Pooled fluids from Ag-challenged sites contained a median of 625 pg/ml (range, 30 to 1250 pg/ml) GM-CSF equivalents, whereas those from the vehicle control-challenged sites contained a median 30 pg/ml (range, 30 to 300 pg/ml) GM-CSF equivalents (p < 0.004 Ag vs control groups, n = 11). Concentrated fluid from Ag- and control-challenged sites in two nonatopic subjects contained < 10 pg/ml cytokine activity. To evaluate the IL-3 and GM-CSF activity with a separate technique, ELISA were performed on separately pooled blister fluids from six atopic subjects. Although no IL-3 activity was detected after Ag challenge in these six subjects, all of them demonstrated levels of GM-CSF at Ag-challenged sites comparable to that found in the bioassay.(ABSTRACT TRUNCATED AT 400 WORDS)     

Effects of exercise on plasma level of brain natriuretic peptide in congestive heart failure with and without left ventricular dysfunction

This study was designed to determine whether plasma brain natriuretic peptide (BNP) increases in response to exercise in patients with congestive heart failure and to show what kind of hemodynamic abnormalities induce increased secretion of BNP during exercise. Plasma levels of atrial natriuretic peptide (ANP) and BNP and hemodynamic parameters were measured during upright bicycle exercise tests in seven patients with dilated cardiomyopathy and nine with mitral stenosis. At rest, there were no intergroup differences in cardiac output or pulmonary capillary wedge pressure; however, the group with dilated cardiomyopathy had higher left ventricular end-diastolic pressures and lower left ventricular ejection fractions than did the group with mitral stenosis. Plasma ANP levels were comparable between the dilated cardiomyopathy group (170 +/- 77 [SE] pg/ml) and the mitral stenosis group (106 +/- 33 pg/ml) (p, not significant), whereas BNP was significantly higher in the dilated cardiomyopathy group (221 +/- 80 pg/ml) than in the other group (37 +/- 10 pg/ml) (p < 0.05). The plasma concentration of BNP but not of ANP significantly correlated with left ventricular end-diastolic pressure and volume. Exercise increased plasma ANP and BNP in the two groups. The dilated cardiomyopathy group had a larger increment in BNP (+157 +/- 79 pg/ml) than did the mitral stenosis group (+17 +/- 5 pg/ml) (p < 0.05), although the increase in pulmonary capillary wedge pressure was greater in the mitral stenosis group. Thus exercise increases plasma levels of BNP, and impaired left ventricular function may be a main factor in the greater increment in BNP during exercise in patients with congestive heart failure.     

Acute and delayed hormonal changes in mitral stenosis treated by balloon valvulotomy

The role of left atrial and aortic pressures on the secretion of the main hormones controlling blood volume is still subject to debate in humans. Because of increased mean left atrial pressure and decreased mean aortic pressure produced by balloon inflation in patients with mitral stenosis treated with balloon valvulotomy, the hormonal changes occurring acutely (group II of patients) were measured. The same studies (group I patients) were also performed 48 hours after this treatment, a period at which left atrial pressure permanently diminished. Inflation of the balloon resulted in a decrease in plasma renin activity and increases in plasma atrial natriuretic factor (ANF) and plasma arginine vasopressin (AVP). Forty-eight hours after balloon valvulotomy, which had produced a decrease in left atrial pressure, plasma ANF was lower (58.9 +/- 7.9 vs 95.3 +/- 11.9 pg/ml; p < 0.001), and plasma renin activity (2,575 +/- 533 vs 960 +/- 113 pg/ml/hour; p < 0.01), plasma angiotensin II (25.0 +/- 4.1 vs 9.3 +/- 1.3 pg/ml; p < 0.001) and plasma aldosterone (181.7 +/- 36.7 vs 139.9 +/- 19.8 pg/ml; p < 0.05) were higher than their respective control levels 24 hours before treatment of the stenosis. In contrast, plasma AVP (3.7 +/- 0.25 vs 4.4 +/- 0.31 pg/ml; p = 0.001) diminished moderately along with plasma osmolality (282.4 +/- 0.1 vs 286.2 +/- 0.6 mOsm/kg; p < 0.001). Urinary sodium excretion was also examined before and after balloon valvulotomy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Basal sympatho-adrenal function in quadriplegic man

Plasma catecholamines (CA) were measured at 15 min intervals over a 4 h time period in 5 supine, chronic, quadriplegic male humans subjects. CA levels fluctuated over time through a wide range, often exhibiting brief bursts of very high CA levels which differed from the slower duration fluctuations seen in normal subjects. Spikes of increased plasma CA often, but not always, correlated with muscle spasms, urination or pain and were often accompanied by appropriate changes in blood pressure and heart rate. When examined over a 4 h period, the subjects' median plasma norepinephrine (NE) levels (305.5 +/- 26.8 pg/ml) were within the normal, age-corrected range while plasma epinephrine (E) levels (210.4 +/- 48.9 pg/ml) were higher than those seen in normal control subjects (89.0 +/- 6.9 pg/ml) tested under similar conditions. Also, plasma NE and E levels in the quadriplegics correlated positively in 3 out of 5 subjects which was similar to the balance in normal subjects. Therefore, resting sympatho-adrenal tone, as indicated by plasma catecholamine levels, in quadriplegics is not decreased, but is either normal or increased. Activation of these systems is probably under the control of local spinal reflexes which appear to be capable of maintaining many of the resting automatic functions of the individual.     

Automated determination of levodopa and carbidopa in plasma by high-performance liquid chromatography-electrochemical detection using an on-line flow injection analysis sample pretreatment unit

This method describes the determination of propiomazine by direct injection of rat plasma into a chromatography system based on coupled reversed-phase columns. An extraction column, packed with porous silica particles with covalent-bound alpha1-acid glycoprotein (AGP), was used to separate the plasma proteins from the analyte. After isolation the analyte was transferred to the analytical column for separation and detection. Propiomazine was detected by an electrochemical detector and the limit of quantification was 2.0 ng/ml (100 pg injected). The absolute recovery was 80.9+/-2.4% at 9.0 ng/ml level. The inter-day and intra-day precision was 10.9% (5.6 ng/ml) and 2.8% (9.0 ng/ml), respectively.     

Column switching in capillary liquid chromatography-tandem mass spectrometry for the quantitation of pg/ml concentrations of the free basic drug tolterodine and its active 5-hydroxymethyl metabolite in microliter volumes of plasma

A capillary column switching system was developed for the determination of low, unbound concentrations of the basic drug tolterodine and its active 5-hydroxymethyl (5-HM) metabolite in human plasma. Free concentrations of tolterodine and 5-HM at pM and nM (pg/ml and ng/ml) levels were obtained by ultrafiltration of 40-400 microliters plasma at 37 degrees C. The free fraction (%) was independent of the plasma concentrations of the analytes. Detection of the analytes was performed by sheathless electrospray tandem mass spectrometry in the multiple-reaction monitoring mode. The selectivity of the mass spectrometric detection and the additional clean-up on the pre-column allowed direct injection of the ultrafiltrated plasma samples. Tolterodine and 5-HM were pre-concentrated on a reversed-phase capillary pre-column (1 cm x 200 microns) and subsequently backflushed onto the separation column (25 cm x 200 microns). The stability of the chromatographic system was good; a large number of ultrafiltrated plasma samples could be injected and the relative standard deviation of the retention times was typically < or = 1% (within-day). The accuracy was between 86 and 105% and the precision was between 1 and 7% without the use of an internal standard. Linear calibration curves were obtained between 100 pM and 100 nM.     

Early changes in plasma brain and atrial natriuretic peptides in premature infants: correlation with pulmonary arterial pressure

To define the change in plasma natriuretic peptides in newborns, we prospectively studied 10 premature infants. They were followed sequentially during the first week of extrauterine life by two-dimensional and pulsed Doppler echocardiography, and studied for atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP). We estimated mean pulmonary arterial pressure (MPAP) and measured blood pressure on days 1, 2, 3, 5, 7, respectively. Plasma ANP levels were 81.7 +/- 11.4 pg/ml on day 1 and 67.9 +/- 6.0 pg/ml on day 7, respectively. Between day 2 and day 7, there was a fall in MPAP, i.e. from 37 +/- 4 mmHg to 22 +/- 2 mmHg (P < 0.01), which was associated with a significant decrease in plasma BNP (41.8 +/- 10.1 pg/ml on day 2 vs. 10.4 +/- 0.9 pg/ml on day 7, P < 0.01). There was a positive correlation between MPAP and plasma BNP level (r = 0.643, P < 0.0001), but there was no correlation between MPAP and plasma ANP level. These data suggest that the pattern of secretion of BNP is different from that of ANP and that BNP levels reflect the changes of pulmonary arterial pressure in the neonatal period in premature infants.     

Interleukin 8 released after acute myocardial infarction is mainly bound to erythrocytes

OBJECTIVE: To determine whether rapid clearance of interleukin 8 (IL-8) from plasma through binding to the erythrocyte chemokine receptor may be responsible for failure to detect IL-8 consistently after acute myocardial infarction. DESIGN: Plasma concentrations of IL-8 were measured at frequent intervals in 43 consecutive patients. In 21 of these, erythrocyte bound IL-8 concentrations were also measured. The influence of infarct size, type of treatment, and the presence of early successful reperfusion on IL-8 release was assessed. RESULTS: Peak IL-8 concentrations in plasma were raised in 31 of the 43 patients (68%). Median plasma IL-8 concentrations were 16.0 pg/ml (range 2.4 to 225.0 pg/ml) six hours after the onset of chest pain. Twelve hours after the onset of symptoms, plasma IL-8 concentrations had already returned to normal in 27 patients. In contrast, in 18 of 21 patients (86%), erythrocyte bound IL-8 concentrations were raised at between 6 and 30 hours, with a median peak value of 59.8 pg/ml (range 19 to 148 pg/ml). No correlation between peak creatine kinase MB and peak IL-8 (plasma or erythrocyte bound) was observed. There was a significant difference in peak plasma IL-8 concentrations between patients who underwent direct PTCA (19.4 pg/ml) and those who received conservative treatment (9.9 pg/ml; p = 0.0206), but no correlation with the presence of early successful reperfusion. CONCLUSIONS: IL-8 is released in plasma after acute myocardial infarction and subsequently binds to red blood cells, resulting in only a transient rise of plasma IL-8 and a more prolonged increase of erythrocyte bound IL-8.     

Catecholamine and blood lactate responses to incremental rowing and running exercise

Ten collegiate rowers performed discontinuous incremental exercise to their tolerable limit on two occasions: once on a rowing ergometer and once on a treadmill. Ventilation and pulmonary gas exchange were monitored continuously, and blood was sampled from a venous catheter located in the back of the hand or forearm for determination of blood lactate ([La]) and plasma epinephrine ([Epi]) and norepinephrine ([NE]) concentrations. Thresholds for lactate (LT), epinephrine (Epi-T), and norepinephrine (NE-T) were determined for each subject under each condition and defined as breakpoints when plotted as a function of O2 uptake (VO2). For running, LT (3.76 +/- 0.18 l/min) was lower (P < 0.05) than Epi-T (4.35 +/- 0.14 l/min) and NE-T (4.04 +/- 0.19 l/min). For rowing, LT (3.35 +/- 0.16 l/min) was lower (P < 0.05) than Epi-T (3.72 +/- 0.22 l/min) and NE-T (3.70 +/- 0.18 l/min) and was lower (P < 0.05) than LT for running. Within each mode of exercise, Epi-T and NE-T did not differ. Because LT occurred at a significantly lower VO2 than either Epi-T or NE-T, we conclude that catecholamine thresholds, per se, were not the cause of LT. However, for both modes of exercise LT occurred at a plasma [Epi] of approximately 200-250 pg/ml (rowing, 221 +/- 48 pg/ml; running, 245 +/- 45 pg/ml); these concentrations are consistent with the plasma [Epi] reported necessary for eliciting increments in blood [La] during Epi infusion at rest. Plasma [NE] at LT differed significantly between modes (rowing, 820 +/- 127 pg/ml; running, 1,712 +/- 217 pg/ml).(ABSTRACT TRUNCATED AT 250 WORDS)     

Quantitative and topographical study of retinal ganglion cells in the chameleon (Chameleo chameleon)

The existence of a circadian rhythm of atrial natriuretic peptide (ANP) in humans is controversial. We studied the plasma ANP response to isotonic blood volume expansion in the morning and in the afternoon and its relationship with adrenocorticotropic hormone (ACTH)-cortisol diurnal variation in seven normal subjects. Basal plasma ANP level was similar in the morning (19.6 +/- 2.4 pg/ml) and in the afternoon (21.8 +/- 4.8 pg/ml). The ANP peak obtained with saline infusion (0.9% NaCl, 12 ml/kg) in the morning (49.4 +/- 8 pg/ml) did not differ from that obtained in the afternoon (60.3 +/- 10.1 pg/ml). There was no correlation between the individual mean cortisol and ACTH levels and the ANP peak obtained with saline infusion. These data indicate no diurnal variation in plasma ANP secretion induced by blood volume expansion and no relationship between plasma ANP peak and ACTH-cortisol diurnal variation.     

Genetic and electrophysiological studies of Drosophila syntaxin-1A demonstrate its role in nonneuronal secretion and neurotransmission

Development of a new method for the determination of Cr(III) and Cr(VI) is described. Anion-exchange high-performance liquid chromatography (HPLC) was used to separate Cr(III) and Cr(VI) with on-line detection by inductively coupled plasma atomic emission spectroscopy (ICP-AES) at 2766 A in preliminary studies, and inductively coupled plasma mass spectrometry (ICP-MS) with single-ion monitoring at m/z 52 and m/z 53 for final work. A mobile phase consisting of ammonium sulfate and ammonium hydroxide was used, and a simple chelation procedure with EDTA was followed to stabilize the Cr(III) species in standard solutions. ICP-MS results indicated the feasibility of using chromium isotope m/z 53 instead of the more abundant m/z 52 isotope due to a high mobile-phase background most significantly from the SO+ polyatomic interference. The absolute detection limits based on peak-height calculations were 40 pg for Cr(III) and 100 pg for Cr(VI) in aqueous media by HPLC-ICP-MS. The linear dynamic range extended from 5 ppb (ng/ml) to 1 ppm (micrograms/ml) for both species. By HPLC-ICP-AES, detection limits were 100 ng for Cr(III) and 200 ng for Cr(VI). Cr(III) was detected in NIST-SRM 1643c (National Institute of Standards and Technology-Standard Reference Material, Trace Elements in Water) by HPLC-ICP-MS at the 20 ppb level.