Catalytic partial oxidation coupled with membrane purification to improve resource and energy efficiency in syngas production.

Catalytic partial oxidation coupled with membrane purification is a new process scheme to improve resource and energy efficiency in a well-established and large scale-process like syngas production. Experimentation in a semi industrial-scale unit (20 Nm(3) h(-1) production) shows that a novel syngas production scheme based on a pre-reforming stage followed by a membrane for hydrogen separation, a catalytic partial oxidation step, and a further step of syngas purification by membrane allows the oxygen-to-carbon ratio to be decreased while maintaining levels of feed conversion. For a total feed conversion of 40 %, for example, the integrated novel architecture reduces oxygen consumption by over 50 %, with thus a corresponding improvement in resource efficiency and an improved energy efficiency and economics, these factors largely depending on the air separation stage used to produce pure oxygen.

IGF-I/IGFBP system: metabolism outline and physical exercise.

The GH/IGF-I system plays a well-known hormonal role and its effects, mainly anabolic and insulin-sensitizing, are mediated through endocrine as well as paracrine/ autocrine mechanisms. This system includes the binding proteins, namely GH binding proteins and IGF-I binding proteins (IGFBP). As expected, this axis plays a key role in organism modification in consequence of a physical exercise. Physical activity, training, and exercise capacity chiefly involve anabolism process modifications of various tissues, in particular muscular adjustments. Numerous investigators found a correlation among the level of exercise tolerance, muscle strength or walking speed and IGF-I/IGFBP-3 concentrations. However, also inverse and absent correlations between circulating IGF-I concentrations and acute or chronic exercise responses have been reported. IGF-I is generally accepted as an important GH mediator with metabolic effects, through both endocrine and paracrine or autocrine mechanisms. GH is the main regulator of the hepatic synthesis of IGF-I and IGFBP-3, which is the most abundant IGF carrier in human plasma. Recently, it has been shown that the physical exercise stimulatory impact on skeletal muscles is mediated through an increased local IGF-I synthesis with an IGFPB involvement. An absent association of exercise performance and circulating IGF-I may indicate that exercise will exert muscle strength by predominately locally derived paracrine or autocrine mediators rather than endocrine circulating IGF-I. The present review considers the general aspects of the IGF/IGFPB system and the role of the IGF/IGFPB system in relation to physical exercise (type, duration, etc.) taking into account the training aspects.

An update: salivary hormones and physical exercise.

Saliva contains cells and compounds, of local and non-local oral origin, namely inorganic, organic non-protein, protein/polypeptide, and lipid molecules. Moreover, some hormones, commonly assayed in plasma, such as steroids, are detectable in oral fluid and peptide/protein, and non-steroid hormones have been investigated. The sports practice environment and athletes' availability, together with hormone molecule characteristics in saliva and physical exercise behavior effects, confirm this body fluid as an alternative to serum. This review focuses on the relation between salivary steroids and psycho-physiological stress and underlines how the measurement of salivary cortisol provides an approach of self-report psychological indicator and anxiety change in relation to exercise performance. The correlation between salivary and plasma steroid hormone (cortisol, testosterone, and dehydroepiandrosterone (DHEA)) levels, observed during exercise, has been considered, underlining how the type, duration, and intensity of the exercise influence the salivary steroid concentrations in the same way as serum-level variations. Training conditions have been considered in relation to the salivary hormonal response. This review focuses on studies related to salivary hormone measurements, mainly steroids, in physical exercise. Saliva use in physical disciplines, as a real alternative to serum, could be a future perspective.

Salivary free insulin-like growth factor-i levels: effects of an acute physical exercise in athletes.

BACKGROUND/AIMS: The offer of human saliva IGF-I (sIGF-I) measurement in athletes investigation is a new proposal. The aim was to investigate the physical exercise effect on sIGF-I and explore plasma free IGF-I relation. MATERIALS AND METHODS: Saliva and blood were collected from well-trained athletes, investigated immediately before and at the end of a physical exercise test. RESULTS: sIGF-I was significantly increased at the end of the physical exercise. The plasma free IGF-I concentrations did not demonstrate any difference. The saliva total protein level (sTP) was also significantly increased. A positive correlation between sTP and sIGF-I, was observed, both before and after physical exercise, and between salivary and plasma free IGF-I only after physical exercise. The salivary free IGF-I level significantly increased after physical exercise, moreover a correlation with the plasma levels exists in post-exercise condition. CONCLUSION: The physical exercise affects sIGF-I as well as the sTP. The correlation between plasma and salivary free IGF-I levels only in post-exercise condition suggests further studies to investigate the effects of different type and duration of physical exercise. The comparison with other salivary biochemical parameter investigation would also further increase comprehension on the role of salivary IGF-I.

Urine cortisol and cortisone and water intake in athletes.

AIM: The aim of this study was to investigate the urine cortisol (F) and cortisone (E) relation, having a well-defined water intake. METHODS: Urine specimens were collected from 10 male trained cyclists (19+/-1 year, 70+/-4 kg, 179+/-4 cm), at rest just before the test (pre-exe) and until 45 min after the cycle ergometer exercise test (45 min at 50-60% VO2max) (post-exe) in the morning. This investigation measured the diuresis in the pre-exe and post-exe after each athlete had drunk 1 L of water from waking-up, after bladder emptying, to the start of the test (pre-exe) and 1 L during the 45 min after the exercise (post-exe). RESULTS: Urinary F and E concentrations demonstrated a significant decrease comparing pre-exe with post-exe (177+/-134 vs 64+/-21 and 706+/-475 vs 372+/-178 nmol.L(-1) respectively, p < 0.05). This significant decrease was verified when diuresis and urinary creatinine were taken into account and the ratio measured. CONCLUSION: One litre of water intake after exercise seemed to have no effect on urine F and E excretion. Moreover the urine F/E ratio was not statistically different comparing pre-exe with post-exe.

Measurement of free IGF-I saliva levels: perspectives in the detection of GH/IGF axis in athletes.

OBJECTIVES: To examine an immunoassay for measuring free IGF-I in a saliva specimen (free sIGF-I) and to study the levels in relation to the training conditions comparing young athletes and sedentary females. DESIGN AND METHODS: The analysis was carried out by modifying a commercial kit for plasma matrix to measure the free sIGF-I. The plasma free and total IGF-I fractions, hGH and salivary total proteins were also measured. Saliva and blood specimens were collected from 15 well-trained young female volleyball athletes and from a control group of 14 young sedentary females. RESULTS: The calibration curve to assay free sIGF-I covered the range 0.05-5.00 microg/L. The detection limit was 0.07 microg/L. The within-run and between-run imprecision CVs were 10% and 13% respectively. The average recovery was 88%. Free sIGF-I, measured in 15 athletes and in 14 young sedentary females, was 0.10+/-0.03 and 0.20+/-0.05 micarog/L respectively (p<0.001). CONCLUSIONS: There were decreased levels of free sIGF-I in well-trained athletes, compared with sedentary females. This decrease could be related to a greater tissue requirement by the active muscle subjected to intense exercise for several days.

First Report of Fusarium Wilt of Flue-Cured Tobacco Caused by Fusarium oxysporum f. sp. batatas in Spain.

Tobacco (Nicotiana tabaccum L.) is among the most important crops in La Vera Region (Cáceres, west-central Spain) where, since 2001, flue-cured tobacco plants showing typical symptoms of a vascular disease associated to the cyst nematode (Globodera tabacum) complex have been frequently observed (2). Symptoms observed were wilting, yellowing, and drying of the leaves, usually on one side of the plant; stunted and distorted leaves with curved midribs due to the unequal growth; and brown vascular discoloration of stems and midribs. Several diseased plants were collected during the summers of 2003 and 2004, and F. oxysporum was consistently isolated from sections of necrotic midribs. To confirm the pathogenicity of F. oxysporum isolates, plants of flue-cured tobacco (cv. Ct-681) were inoculated. Since Fusarium wilt of tobacco may be caused by F. oxysporum f. sp. vasinfectum or F. oxysporum f. sp. batatas (1), plants of cotton (cv. Acala) and sweet potato (cvs. Nemagold and Nancy Hall) were also inoculated to determine the forma specialis designation. Twenty plants per cultivar and isolate were inoculated with six isolates at the two to four true-leaf stage by pouring into the substrate 200 ml of a conidial suspension (1 × 105 CFU/ml). After inoculation, plants were incubated in a growth chamber at 28°C (day) and 24°C (night) with a 16-h photoperiod. All six F. oxysporum isolates were pathogenic to tobacco and sweet potato, but there were differences among isolates in time from inoculation to appearance of first disease symptoms (7 to 15 days after inoculation in tobacco and sweet potato) and also in disease severity 30 days after inoculation (60 to 100% wilt or mortality in tobacco and 50 to 100% in sweet potato). F. oxysporum was reisolated from stems of inoculated plants. No disease symptom was observed in cotton plants 60 days after inoculation, and F. oxysporum was not reisolated from them. Results of inoculation on the differential hosts indicated that disease symptoms in tobacco were caused by F. oxysporum f. sp. batatas. To our knowledge, this is the first report of F. oxysporum f. sp. batatas causing disease in flue-cured tobacco in Spain. References: (1) G. M. Armstrong and J. K. Armstrong. Phytopathology 58:1242, 1968. (2) G. Espárrago and I. Blanco. Plant Dis. 86:1402, 2002.

Elite volunteer athletes of different sport disciplines may have elevated baseline GH levels divorced from unaltered levels of both IGF-I and GH-dependent bone and collagen markers: a study on-the-field.

Seventy-seven Italian eliteathletes(42 M, 35 F, mean age +/- SE: 24.4-0.7 yr, age range: 17-47 yr) of different sport disciplines (sprinters, triathletes, middle-distance runners, road-walkers, cyclists, rowing athletes, skiers, roller hockey players, swimmers) were sampled on-the-field (before a training session) for the determination of basal GH, IGF-I, C-terminal cross-linked telopeptide of type I collagen (ICTP) and amino-terminal propeptide of type III procollagen (PIIINP) levels, two GH-dependent peripheral markers of bone and collagen turnover, respectively. Basal GH concentrations were significantly higher (p<0.001) in female (5.8 +/- 1.0 ng/ml) vs male athletes (1.8 +/- 0.5 ng/ml), with a large spread of values in either gender. Mean GH levels of athletes were significantly higher than those recorded in age-matched sedentary controls (females: 2.5 +/- 0.5 ng/ml, p<0.001; males: 0.5 +/- 0.2 ng/ml, p<0.05). Among female athletes, 7/35 had basal GH values higher than the upper limit of control values (>9.5 ng/ml), while among males 7/42 had values higher than the upper limit of male sedentary controls (>3.6 ng/ml). No significant differences in basal GH concentrations were found between females taking oral contraceptives (OC) and those who did not receive this treatment (5.0 +/- 2.1 vs 6.0 +/- 1.2 ng/ml). IGF-I levels (236.4 +/- 7.8 ng/ml) were in the normal range for age in all athletes (except for 1 athlete with slightly increased levels), no significant correlation being found between GH and IGF-I levels (R2=0.0393). Mean ICTP (4.6 +/- 0.2 ng/ml) and PIIINP (4.4-0.1 ng/ml) concentrations of elite athletes were not significantly different from those recorded in age and matched healthy sedentary subjects; 4 athletes showed increased PIIINP levels and 2 had increased ICTP levels. ICTP and PIIINP levels were positively correlated with chronological age (p<0.001), a positive correlation being also found between the two markers (p<0.001). On the contrary, no significant correlation was found between basal GH/IGF-I levels and ICTP/PIIINP levels. In conclusion, the present study demonstrates that: 1) elite athletes (particularly females), which have frequently increased basal GH on-the-field, have actually normal IGF-I levels; 2) ICTP and PIIINP levels of athletes are similar to those recorded in healthy sedentary, being significantly higher in younger subjects of both groups; 3) the presence of increased basal GH levels, being associated with normal IGF-I, ICTP and PIIINP levels, is probably the result of a transient GH peak in this study group. Further additional studies are requested to verify the possible use of these peripheral GH-dependent markers for detecting exogenous chronic administration of recombinant GH in athletes.

Gender-, age-, body composition- and training workload-dependent differences of GH response to a discipline-specific training session in elite athletes: a study on the field.

Ninety-nine Italian elite athletes (61 M, 38 F, mean age +/- SE: 24.1 +/- 0.6 yr, age range: 17-47 yr) of different disciplines volunteered to participate in this investigation. Basal GH concentrations were significantly higher (p<0.0001) in females (6.2 +/- 1.1 ng/ml) vs males (1.9 +/- 0.5 ng/ml). Basal GH values were negatively correlated with age and body mass index (BMI); no significant correlation was found between GH and IGF-I levels. Among female athletes, 8/38 had basal GH values higher than 10 ng/ml [2/8 athletes were taking oral contraceptives (OC)], while among males 6/61 had values higher than 5 ng/ml. In females, training sessions significantly increased (p<0.0001) basal GH concentrations (peak GH: 18.5 +/- 1.9 ng/ml), while in males GH responses were lower than in females (11.8 +/- 1.4 ng/ml, vs F: p<0.005). Six out of 38 female and 6/61 male athletes were considered GH hypo-responders (i.e. negative difference between peak GH and basal GH values), the large majority of them being subjects with elevated basal GH concentrations. In responsive athletes, peak GH values occurred immediately at the end of the training session both in males and in females; GH concentrations rapidly declined during recovery. No significant correlations were found between peak GH and age, body weight and BMI in either gender. GH responses were directly related (p<0.001) to the intensity of the workload during the sessions. In conclusion, the present study demonstrates that: 1) some elite athletes had increased GH concentrations before training, which were however associated with normal IGF-I levels; 2) GH peaks after a discipline-specific training session were significantly higher in females than in males performing the same discipline, gender-related differences disappearing when post-exercise total GH outputs (area under the curve) were compared; 3) peak GH values were directly correlated with training workload; 4) GH concentrations rapidly declined during recovery, values at the end of the post-training GH sampling being generally lower than those found in basal condition.

GH/IGF system, cirrhosis and liver transplantation.

The GH-related effects are primarily mediated by insulin-like growth factor I (IGF-I), a peptide hormone almost completely produced by the liver. Liver cirrhosis is usually accompanied by a fall in protein turnover. Furthermore, an important consequence of chronic liver disease (CLD) is growth hormone/insulin-like growth factor (GH/IGF) axis modification and growth failure. Nutritional status also suffers in this condition, and IGF-I has been proposed as a marker of hepatocellular dysfunction, malnutrition and survival. CLD is characterised by alterations of various clinical biochemistry laboratory parameters. Aminotransferases, bilirubin, plasma proteins, together with prothrombin time and gamma globulins, are usually examined for laboratory diagnostic and/or monitoring purposes. These traditional parameters are also used in the perioperative liver transplantation, but an early signal of graft functioning has still not been established. The aim of the present work is a review of the possibility offered by the clinical biochemistry laboratory GH/IGF investigation in the outcome of liver transplantation.

Physiological and clinical implications of proANP(1-98) circulating levels in the perioperative phase of liver transplantation.

BACKGROUND: ProANP(1-126), the prohormone synthesized and secreted by atrial myocites, generates an ANP peptide family, the main forms of which are proANP(1-30), proANP(31-67), proANP(1-98) and proANP(99-126). These molecular circulating forms are involved in hemodynamic and electrolyte homeostasis. In cirrhotic patients, volume homeostasis is almost impaired due to abnormal sodium retention, which results in ascites formation and hemodynamic changes, including high cardiac output and low systemic vascular resistance. During liver transplantation, in the anhepatic phase, hemodynamic instability may occur because of decreased venous return due to surgical manipulation of inferior vena cava, considerable blood loss or cross-clamping. Moreover, marked hemodynamic instability is often observed at the reperfusion of the graft. AIMS: The aims of present study are to investigate the changes of ANP during the perioperative phases of Orthotopic Liver Transplantation (OLTx) in end-stage cirrhotic patients. PATIENTS AND METHODS: From July to September 1999, 11 cirrhotic patients undergoing to OLTx were included in the study: seven males and four females (average age 46+/-10.4 years) affected by post-alcoholic cirrhosis [Hypertension 15 (1990) 9], post-hepatitis cirrhosis [D.G. Gardner, M.C. Lapointe, B. Kovacic-Milivojevic, C.F. Deschepper, Molecular analisys and regulation of the atrial natriuretic factor gene, in: A.D. Struphers (Ed.), Frontiers in Farmacology and Therapeutics: Atrial Natriuretic Factor, Blackwell, Oxford, England, 1991, pp. 1-22], Wilson disease [Life Sci. 28 (1981) 89] and polycystic disease [Life Sci. 28 (1981) 89], autoimmune cirrhosis [Life Sci. 28 (1981) 89]. In each patient, a hemodynamic assessment was achieved using a Swan-Ganz catheter. Periferical venous samples were performed during and immediately after OLTx for the determination of ANP(1-98) and other biohumoral parameters. RESULTS: Mean ANP(1-98) (pmol/ml mean+/-SD) basal levels resulted higher than that recorded in the group of healthy subjects. A significant correlation between 24-h post-reperfusion ANP and intra-operative RBC and RIS requirement was found (p<0.05). The basal values resulted significantly higher than that observed at phase II degrees (p<0.04) and lower than that at phase VI degrees (p<0.05); the anesthetic induction values were significantly lower than that observed at phase VI degrees (p<0.03). CONCLUSIONS: ANP(1-98) values may represent a useful marker of hemodynamic derangements during and after OLTx. Further clinical correlations will need a larger patient basis.

Plasma atrial natriuretic peptide (ANP) fragments proANP (1-30) and proANP (31-67) measurements in chronic heart failure: a useful index for heart transplantation?

The family of the atrial natriuretic peptides, proANP fragments and the active alphaANP, is strongly related to heart disease. The aim was to study in CHF subjects the relation of mdANP and NtANP with brain natriuretic peptide (BNP) and with other traditional medical parameters. Sixteen CHF patients (aged 51.9+/-13.7 years) and 16 healthy subjects age matched (50.8+/-5.9 years) were selected. Both NtANP and mdANP were higher in CHF patients than in healthy subjects (1436+/-288 vs. 288+/-22 pmol/l p<0.001 and 2305+/-383 vs. 423+/-65 pmol/l p<0.0001, respectively). BNP in CHF patients was 28.0+/-9 pmol/l (reference values 1.7+/-1.8 pmol/l). Both NtANP and mdANP demonstrated positive correlation with BNP, p<0.0001 and with left atrial end-systolic volume, p<0.05. BNP correlated with left ventricular mass, p<0.03. In conclusion, plasma NtANP and mdANP analyses are useful laboratory markers in CHF patient investigation and follow up. In particular, they could be employed as non-invasive parameters to follow up worsening of systolic dysfunction until heart transplantation is required.

Circulating immunoreactive proANP1-30 and proANP31-67 responses to acute exercise.

The circulating immunoreactive atrial natriuretic peptide (C-terminal; alpha-ANP) increases during exercise to become suppressed in the first hours of the recovery. The response of the N-terminal ANP fragments to acute exercise is not known while proANP (31-67) appears to be elevated with chronic exercise. We evaluated the plasma concentrations of the N-terminal ANP fragments (1-30) and (31-67) in oarsmen (n=10) before and after two acute exercise bouts separated by 5 h. As control, measurements were made on a day with no exercise (n=12). At rest, the concentrations of proANP(1-30) and proANP(31-67) were 344+/-42 and 810+/-172 pmol x l(-1), respectively. Half an hour after the first exercise bout, proANP(1-30) was elevated (to 404+/-48 pmol x l(-1); P<0.05) and decreased below the pre-exercise level (to 316+/-41 pmol x l(-1); P<0.05) 4 h into the recovery period. Also, 30 min after the second exercise session, the concentration of proANP(1-30) was elevated to 408+/-45 pmol x l(-1) (P<0.05) and the pre-exercise level was re-established on the following morning. Thus, proANP(1-30), rather than proANP(31-67), responded to acute exercise. These results suggest that atrial distension and, therefore, the central blood volume changes markedly in athletes during a day with repeated exercise bouts.

Plasma lactate, GH and GH-binding protein levels in exercise following BCAA supplementation in athletes.

Branched chain amino acids (BCAA) stimulate protein synthesis, and growth hormone (GH) is a mediator in this process. A pre-exercise BCAA ingestion increases muscle BCAA uptake and use. Therefore after one month of chronic BCAA treatment (0.2 gkg(-1) of body weight), the effects of a pre-exercise oral supplementation of BCAA (9.64 g) on the plasma lactate (La) were examined in triathletes, before and after 60 min of physical exercise (75% of VO2 max). The plasma levels of GH (pGH) and of growth hormone binding protein (pGHBP) were also studied. The end-exercise La of each athlete was higher than basal. Furthermore, after the chronic BCAA treatment, these end-exercise levels were lower than before this treatment (8.6+/-0.8 mmol L(-1) after vs 12.8+/-1.0 mmol L(-1) before treatment; p < 0.05 [mean +/- std. err.]). The end-exercise pGH of each athlete was higher than basal (p < 0.05). Furthermore, after the chronic treatment, this end-exercise pGH was higher (but not significantly, p = 0.08) than before this treatment (12.2+/-2.0 ng mL(-1) before vs 33.8+/-13.6 ngmL(-1) after treatment). The end-exercise pGHBP was higher than basal (p < 0.05); and after the BCAA chronic treatment, this end-exercise pGHBP was 738+/-85 pmol L(-1) before vs 1691+/-555 pmol L(-1) after. pGH/pGHBP ratio was unchanged in each athlete and between the groups, but a tendency to increase was observed at end-exercise. The lower La at the end of an intense muscular exercise may reflect an improvement of BCAA use, due to the BCAA chronic treatment. The chronic BCAA effects on pGH and pGHBP might suggest an improvement of muscle activity through protein synthesis.

Registration of external causes of death in the Baltic States 1970-1997.

BACKGROUND: Trends in external causes of deaths in the Baltic States--Estonia, Latvia and Lithuania--were analysed against the background of turbulent political, social and economic changes. The reliability of mortality statistics concerning external causes of death in these countries is considered to be good. METHOD: This study is based on data published by the statistical offices of the three Baltic States and on data obtained through interviews with personnel employed at the national statistical offices. The study period was divided, by socio-political and economic factors, into a period of stagnation (1970-1984) and a period of reforms (1985-1997). RESULTS: During 1970-1984 a stable slightly upward trend of external causes of death rates was observed. The curve became S-shaped in the reform period: between 1984 and 1988 a marked decrease occurred followed by a rapid increase of rates until 1994, and then by 1997 a fall to the approximate level of 1984. The male to female ratio of external causes of death was between 3.4:1 and 4.2:1. External deaths accounted for 10% to 14% of all deaths before 1984. During the period 1984-1988 the proportion of external deaths was under 10% and peaked in 1994 at 16%. Fluctuations in the trends of external death were more pronounced among males than females in all Baltic countries. CONCLUSION: Trends in external causes of death were similar in Baltic States. High proportions of violent death decreased life-expectancy for both sexes, but markedly for males. Social stresses and alcohol consumption could be considered as factors influencing the mortality rates and specific fluctuations in trends of external death, especially among males.

Correlations of growth hormone (GH) and insulin-like growth factor I (IGF-I): effects of exercise and abuse by athletes.

The importance of hormones on body metabolism when physical exercise is carried out has been established for a long time. Growth hormone (GH) is crucial in energy metabolism as well as in body anabolism. Recent studies have increased our knowledge of GH's mechanisms of action. In particular, insulin-like growth factor I (IGF-I), the main hormone mediating the principal GH effects and other protein structures (i.e. the binding proteins related to these two hormones), has been recognized as playing a crucial role. The biochemical aspects relating to the molecules of the GH/IGF-I axis have been described here. Furthermore, the belief that GH and IGF-I enhance performance has induced an 'abuse' of GH (and possibly of IGF-I) by competitive sports athletes and amateurs. The present study outlines the best methods available to uncover abuse, as well as a series of potential research projects to recognize doping. The review also underlines the principal variables measurable in the laboratory and summarizes published reference ranges of these parameters. These biochemical and laboratory profiles describe principal experimental approaches, with the hope that this will stimulate new ideas on the subject of detecting doping practices.

Separation methods for acyclovir and related antiviral compounds.

Acyclovir (ACV) is an antiviral drug, which selectively inhibits replication of members of the herpes group of DNA viruses with low cell toxicity. Valaciclovir (VACV), a prodrug of ACV is usually preferred in the oral treatment of viral infections, mainly herpes simplex virus (HSV). Also other analogues such as ganciclovir and penciclovir are discussed here. The former acts against cytomegalovirus (CMV) in general and the latter against CMV retinitis. The action mechanism of these antiviral drugs is presented briefly here, mainly via phosphorylation and inhibition of the viral DNA polymerase. The therapeutic use and the pharmacokinetics are also outlined. The measurement of the concentration of acyclovir and related compounds in biological samples poses a particularly significant challenge because these drugs tend to be structurally similar to endogenous substances. The analysis requires the use of highly selective analytical techniques and chromatography methods are a first choice to determine drug content in pharmaceuticals and to measure them in body fluids. Chromatography can be considered the procedure of choice for the bio-analysis of this class of antiviral compounds, as this methodology is characterised by good specificity and accuracy and it is particularly useful when metabolites need to be monitored. Among chromatographic techniques, the reversed-phase (RP) HPLC is widely used for the analysis. C18 Silica columns from 7.5 to 30 cm in length are used, the separation is carried out mainly at room temperature and less than 10 min is sufficient for the analysis at 1.0-1.5 ml/min of flow-rate. The separation methods require an isocratic system, and various authors have proposed a variety of mobile phases. The detection requires absorbance or fluorescence measurements carried out at 250-254 nm and at lambdaex=260-285 nm, lambdaem=375-380 nm, respectively. The detection limit is about 0.3-10 ng/ml but the most important aspect is related to the sample treatment, mainly when body fluids are under examination. The plasma samples obtained from human blood are pre-treated with an acid or acetonitrile deproteinization and the supernatant after centrifugation is successively extracted before RP-HPLC injection. Capillary Electrophoresis methods are also discussed. This new analytical approach might be the expected evolution, in fact the analyses are improved with regard to time and performance, in particular coated capillary as well as addition of stabilisers have been employed. The time of analysis is shortened arriving at less than half a minute. Furthermore by using an electrochemical detection, and having a calibration linearity in the range of 0.2-20.0 ng/ml, the detection limit is 0.15 microg/ml. The measurements of acyclovir and penciclovir have been presented but in the future other related drugs will probably be available using CE methods.

Circulating immunoreactive proANP(1-30) and proANP(31-67) in sedentary subjects and athletes.

BACKGROUND: Atrial natriuretic peptide (ANP) is synthesized and stored in myocytes as prohormone(1-126), which upon release is cleaved into proANP(1-98) and alpha-ANP(99-126). In addition, cleavage of proANP(1-98) produces proANP(1-30), proANP(31-67), and proANP(79-98) fragments. ProANP(1-30) and proANP(31-67) have roles in fluid and electrolyte homeostasis. The aim of the present study was to develop a plasma assay for proANP(1-30) and proANP(31-67) and to compare results in trained athletes and sedentary subjects. METHODS: Two competitive enzyme immunoassays were established with affinity-purified sheep antiserum against synthetic ANP fragments. The immunoreactivity (ir) of proANP(1-30) and proANP(31-67) was measured in 10-microL plasma samples without extraction in a microwell-based assay. Plasma concentrations in sedentary male subjects (n = 22) and male endurance athletes (n = 14) were examined. RESULTS: In the assay for ir-proANP(1-30) and ir-proANP(31-67), the concentrations at 95% B/B(0) were 4.7 and 14.2 pmol/L, respectively. Within-run CVs were 4-6% and 5-6%, and between-run CVs were 9% for both assays. Both assays were linear on dilution (y = 0.9945x - 0. 7291 and y = 1.0001x - 3.428), and the recoveries were 102-112% and 102-106%, respectively. In the sedentary and athletic groups, the ir-proANP(1-30) concentrations were similar: 318 +/- 38 pmol/L and 312 +/- 25 pmol/L (mean +/- SE), respectively, whereas the ir-proANP(31-67) was higher in the rowers (713 +/- 81 pmol/L) than in the sedentary subjects (387 +/- 71 pmol/L; P <0.005). CONCLUSIONS: The proANP fragment assays are precise (CV <10%) and exhibit nearly quantitative recovery (102-112%). Only ir-proANP(31-67) responds to physical training.

A rapid urine creatinine assay by capillary zone electrophoresis.

Using capillary zone electrophoresis, the urine creatinine (uCr) assay was validated in extemporaneous diluted urine, both in healthy subjects and athletes, with the uCr concentration as a reference value to compare excretion rates of other metabolites in the same samples. The electrokinetic sample injection was carried out at 10 kV per 10 s; UV absorbance detection was at 254 nm. Using standard samples, the creatinine migration mean time in 100 mmol/L acetate buffer, pH 4.4, was 3.3+/-0.2 min; the repeatability for absolute migration mean time was 0.6% and peak height repeatability was 2.9%. The correlation coefficient of the standard curve was r = 0.999 and the detection limit was 23.1 micromol/L. Intra- and interassay coefficients of variation (CV) were 3.0 and 3.6%, respectively; recovery was 99+/-3% and linearity was r= 0.98. Normal urine samples were diluted 1:80 in run buffer. The present CE urine creatinine assay showed a good correlation with HPLC and with Jaffe methods (r = 0.98 and r = 0.97, respectively; p < 0.0001). The uCr in the morning urine samples of 34 healthy males (M), 38 healthy females (F), and 83 male athletes (A) was 10.4+/-6.1 mmol/L, 10.8+/-8.1 mmol/L and 13.2+/-6.5 mmol/L, respectively. The uCr difference (p < 0.02) between M and A and a correlation (p < 0.05) with age in A were observed.