Determination of soluble angiotensin-converting enzyme 2 in saliva samples and its association with nicotine

INTRODUCTION

The Angiotensin-Converting Enzyme 2 (ACE2) is the main receptor of the SARS-CoV-2. There is contradictory evidence on how the exposure to nicotine may module the concentration of soluble ACE2 (sACE2). The aim of this study was to assess the association between nicotine and sACE2 concentrations in saliva samples.

METHODS

Pooled analysis performed with data retrieved from two studies (n = 634 and n = 302). Geometric mean (GM) concentrations of sACE2, both total and relative to the total amount of protein in the sample, were compared according to sociodemographic variables and variables associated to nicotine. Multivariable linear regression models were fitted to explore the associations of sACE2 with nicotine adjusting for sex, age and body mass index. Spearman's rank-correlation coefficients were estimated between the concentrations of nicotine and cotinine, and pack-years, the concentration of relative sACE2 and the isoforms of sACE2.

RESULTS

We observed a significant increase of 0.108‰ and 0.087 ng/μl in the relative and absolute salivary sACE2 GM concentrations, respectively, between the lowest and highest nicotine levels. Similar results were observed for cotinine. These associations did not change in the multivariable linear models. There was a low correlation of nicotine and cotinine concentration with the concentration of relative salivary sACE2 (r_s = 0.153 and r_s = 0.132, respectively), pack-years (r_s = 0.222 and r_s = 0.235, respectively) and with the concentration of isoform 40 KDa (r_s = 0.193 and r_s = 0.140, respectively).

CONCLUSION

Salivary nicotine concentration seems to be limitedly associated with the concentration of sACE2.

Polyurethane Foam Residue Biodegradation through the Tenebrio molitor Digestive Tract: Microbial Communities and Enzymatic Activity

Polyurethane (PU) is a widely used polymer with a highly complex recycling process due to its chemical structure. Eliminating polyurethane is limited to incineration or accumulation in landfills. Biodegradation by enzymes and microorganisms has been studied for decades as an effective method of biological decomposition. In this study, Tenebrio molitor larvae (T. molitor) were fed polyurethane foam. They degraded the polymer by 35% in 17 days, resulting in a 14% weight loss in the mealworms. Changes in the T. molitor gut bacterial community and diversity were observed, which may be due to the colonization of the species associated with PU degradation. The physical and structural biodegradation of the PU, as achieved by T. molitor, was observed and compared to the characteristics of the original PU (PU-virgin) using Fourier Transform InfraRed spectroscopy (FTIR), Thermal Gravimetric Analysis (TGA), and Scanning Electron Microphotography (SEM).

Secondhand Tobacco Smoke and Functional Impairments in Older Adults Living in the Community

BACKGROUND/AIM

There has been no comprehensive examination of the potential association of SHS with broad functional limitation assessment in older adults, where functional limitations are burdensome and challenging.

METHODS

We examined 2258 community-dwelling non-smoking older adults from the Seniors-Enrica-2-cohort. At baseline (2017) and follow-up (2019) grip strength was measured with a Jamar dynamometer, lower-extremity performance with the Short Physical Performance Battery (SPPB), overall physical function using the physical component summary (PCS) of the Spanish version of the SF-12, frailty with a Deficits Accumulation Index (DAI), and mobility limitations with the Rosow-Breslau scale. Baseline exposure to SHS was assessed by serum cotinine, and past exposure was self-reported. Cross-sectional analyses were performed using linear and logistic regression models, whereas functional performance changes were examined using repeated measures models with robust SE estimates.

RESULTS

Overall, the median (IQR) serum cotinine concentration was 0.079 (0.035-0.175) ng/ml, with 20 participants presenting concentrations ≥3 ng/ml. Compared to the unexposed, fully-adjusted models showed that the highest exposure group (≥0.239 ng/ml) presented lower grip strength (mean difference: -1.05 kg; 95% CI = -1.80, -0.31) and higher DAI scores (1.52; 95% CI = 0.38, 2.66) at baseline. Similarly, in models of self-reported past exposure, never-smokers who had lived with ≥2 smokers or been exposed to higher SHS cumulative doses showed lower baseline SPPB values, higher DAI scores, and higher prevalence of mobility limitations. In prospective analyses, those in the highest quartile of baseline cotinine presented harmful SPPB [-0.24 (-0.46, -0.02)] and DAI [1.28 (0.00, 2.55)] changes, and higher risk of mobility limitations [hazard ratio: 1.64; 95% CI = 1.01, 2.68] than the unexposed.

CONCLUSIONS

SHS exposure over the life-course and during old age may accelerate functional decline.

IMPLICATIONS

This manuscript provides a comprehensive examination of the relationship between secondhand smoke exposure and a broad range of functional limitations in older adults. Results show that: (i) non-smokers who had been exposed to higher cumulative doses of SHS in adulthood show worse physical function than non-exposed. (ii) Exposure to SHS during old age, as measured with cotinine concentrations, is associated with accelerated short-term functional declines. (iii) The effects of SHS are stronger among older adults with chronic morbidities. (iv) Results suggest that more efforts are needed to protect older adults from passive smoking, especially to those with chronic conditions because of their potential greater vulnerability to the effects of SHS.

Thermogravimetry coupled with mass spectrometry successfully used to quantify polyethylene and polystyrene microplastics in organic amendments

The global consumption of plastic is growing year by year, producing small plastic pieces known as microplastics (MPs) that adversely affect ecosystems. The use of organic amendments (compost and manure) polluted with MPs affects the quality of agricultural soils, and these MPs can be incorporated into the food chain and negatively impact human health. Current European legislation only considers large plastic particles in organic amendments. There is no information regarding MP pollution. Thus, the development of a methodology to support future legislation ensuring the quality of agricultural soils and food safety is necessary. This proposed methodology is based on thermogravimetry coupled with mass spectrometry to quantify polyethylene and polystyrene (PE and PS) MPs through their mass spectrometry signal intensity of characteristic PE (m/z 41, 43 and 56) and PS (m/z 78 and 104) ions. This method has been validated with several organic amendments where the MP content ranged from 52.6 to 4365.7 mg kg^-1 for PE-MPs and from 1.1 to 64.3 mg kg^-1 for PS-MPs. The proposed methodology is a quick and robust analytical method to quantify MPs in organic amendments that could support new legislation.

Objectively measured secondhand tobacco smoke and cognitive impairment in disability-free older adults

Previous studies have suggested that exposure to secondhand smoke (SHS) may be associated with greater risk of cognitive impairment. However, no longitudinal study has examined the association of serum cotinine (as objective measure of SHS exposure) and cognitive function in older adults. We used data from 2087 non-smoking adults aged≥65 years participating in the ENRICA-2 cohort and free from limitations in Instrumental Activities of Daily Living. Cognitive function was assessed through the Mini-Mental State Examination (MMSE), the Digit Span Backwards subtest (DSBT), the Luria's motor series subtest from the Frontal Assessment Battery, the Trail Making Test A (TMT-A), the Free and Cued Selective Reminding Test (FCSRT), and the Categorical Verbal Fluency Test (CFT) of the 7 min test. Cross-sectional analyses were performed using multivariable logistic and ordered logistic models, while analyses on changes in cognition over time used multivariable repeated-measures mixed-effects models. Compared to the unexposed, those in the highest exposure group (≥0.161 ng/ml) were more likely to have cognitive impairment (MMSE<24) (odds ratio [OR]:1.64; 95% confidence interval [CI]:1.04-2.60) and lower DSBT scores (OR:1.25; 95%CI:1.00-1.57), as well as a non-significant higher odds of a lower score in the Luria test (OR:1.23; 95%CI:0.92-1.64) or episodic memory impairment (FCSRT<12, OR:1.38; 95%CI:0.90-2.11). In longitudinal analyses, those with baseline cotinine ≥0.161 ng/ml showed an increased risk of cognitive impairment (MMSE<24,OR:2.23; 95%CI:1.14-4.33; p-trend across cotinine categories = 0.028) and decreased DSBT (OR:1.23; 95%CI:1.01-1.51; p-trend across cotinine categories = 0.046). Findings show an increased risk of global cognitive impairment and declines in working memory performance in older adults exposed to SHS. More efforts are needed to protect older adults from SHS in areas not covered by smoke-free legislation.

Microbiota Characterization of Compost Using Omics Approaches Opens New Perspectives for Phytophthora Root Rot Control

Phytophthora root rot caused by Phytophthora nicotianae is an economically important disease in pepper crops. The use of suppressive composts is a low environmental impact method for its control. Although attempts have been made to reveal the relationship between microbiota and compost suppressiveness, little is known about the microorganisms associated with disease suppression. Here, an Ion Torrent platform was used to assess the microbial composition of composts made of different agro-industrial waste and with different levels of suppressiveness against P. nicotianae. Both bacterial and fungal populations responded differently depending on the chemical heterogeneity of materials used during the composting process. High proportions (67–75%) of vineyard pruning waste were used in the most suppressive composts, COM-A and COM-B. This material may have promoted the presence of higher relative abundance of Ascomycota as well as higher microbial activity, which have proved to be essential for controlling the disease. Although no unique fungi or bacteria have been detected in neither suppressive nor conducive composts, relatively high abundance of Fusarium and Zopfiella were found in compost COM-B and COM-A, respectively. To the best of our knowledge, this is the first work that studies compost metabolome. Surprisingly, composts and peat clustered together in principal component analysis of the metabolic data according to their levels of suppressiveness achieved. This study demonstrated the need for combining the information provided by different techniques, including metagenomics and metametabolomics, to better understand the ability of compost to control plant diseases.

Molecular methods (digital PCR and real-time PCR) for the quantification of low copy DNA of Phytophthora nicotianae in environmental samples

BACKGROUND

Currently, real-time polymerase chain reaction (qPCR) is the technique most often used to quantify pathogen presence. Digital PCR (dPCR) is a new technique with the potential to have a substantial impact on plant pathology research owing to its reproducibility, sensitivity and low susceptibility to inhibitors. In this study, we evaluated the feasibility of using dPCR and qPCR to quantify Phytophthora nicotianae in several background matrices, including host tissues (stems and roots) and soil samples.

RESULTS

In spite of the low dynamic range of dPCR (3 logs compared with 7 logs for qPCR), this technique proved to have very high precision applicable at very low copy numbers. The dPCR was able to detect accurately the pathogen in all type of samples in a broad concentration range. Moreover, dPCR seems to be less susceptible to inhibitors than qPCR in plant samples. Linear regression analysis showed a high correlation between the results obtained with the two techniques in soil, stem and root samples, with R(2) = 0.873, 0.999 and 0.995 respectively.

CONCLUSIONS

These results suggest that dPCR is a promising alternative for quantifying soil-borne pathogens in environmental samples, even in early stages of the disease.

Presence of pharmaceuticals and heavy metals in the waters of a Mediterranean coastal wetland: Potential interactions and the influence of the environment

The occurrence of 17 relevant pharmaceuticals and 7 heavy metals in the waters of the Pego-Oliva Marsh Natural Park (Valencia Community, Spain) were monitored. Thirty four zones (including the lagoon and the most important irrigation channels), covering the main land uses and water sources, were selected for sampling. Thirty three of them were contaminated with at least one pharmaceutical. Ibuprofen and codeine were the pharmaceuticals more frequently detected, in concentrations between 4.8 and 1.2 ng/L and a maximum of 59 ng/L and 63 ng/L, respectively. Regarding metals, Zn showed values under the detection limit in all the samples, while Cd, Co, Cr, Cu, Ni and Pb were detected at concentrations lower than the WHO and EU maximum levels for drinking waters. Ni showed significant direct correlations with diazepam, norfloxacin, ofloxacin and fenofibrate, and inverse relationships with ibuprofen, at 99 and 95% of significance. Cu, Co and Cr also showed significant correlations with some of the pharmaceuticals. These interactions could favor the synergistic/antagonistic interactions among pharmaceuticals and metals in the marsh, which can affect its aquatic fauna and flora or even human health. The influences of the water sources, land uses and spatial distribution of both types of contaminants were also studied.

Characterization of Phytophthora nicotianae isolates in southeast Spain and their detection and quantification through a real-time TaqMan PCR

BACKGROUND

The soil-borne pathogens Phytophthora nicotianae and P. capsici are the causal agents of root and stem rot of many plant species. Although P. capsici was considered the causal agent in one of the main pepper production areas of Spain to date, evidence of the presence of P. nicotianae was found. We aimed to survey the presence of P. nicotianae and study the variability in its populations in this area in order to improve the management of Tristeza disease.

RESULTS

A new specific primer and a TaqMan probe were designed based on the internal transcribed spacer regions of ribosomal DNA to detect and quantify P. nicotianae. Both morphological and molecular analysis showed its presence and confirmed it to be the causal agent of the Phytophthora disease symptoms in the studied area. The genetic characterization among P. nicotianae populations showed a low variability of genetic diversity among the isolates. Only isolates of the A2 mating type were detected.

CONCLUSIONS

Not only is a specific and early detection of P. nicotianae essential but also the study of genetic variability among isolates for the appropriate management of the disease, above all, in producing areas with favorable conditions for the advance of the disease.

Archaeal community dynamics and abiotic characteristics in a mesophilic anaerobic co-digestion process treating fruit and vegetable processing waste sludge with chopped fresh artichoke waste

This study evaluated the feasibility of obtaining methane in anaerobic digestion (AD) from the waste products generated by the processing of fruit and vegetables. During the first phase (0-55 d) of the AD using sludge from fruit and vegetable processing, an average value of 244±88 L kg(-1) dry matter d(-1)of biogas production was obtained, and methane content reached 65% of the biogas. Co-digestion with chopped fresh artichoke wastes in a second phase (55-71 d) enhanced biogas production, and resulted in an average value of 354±68 L kg(-1) dry matter d(-1), with higher methane content (more than 70%). The archaeal community involved in methane production was studied using the ANAEROCHIP microarray and real-time PCR. Results indicated that species of Methanosaeta and Methanosarcina were important during the AD process. Methanosarcina numbers increased after the addition of chopped fresh artichoke, while Methanosaeta numbers decreased.

Deciphering the hormonal signalling network behind the systemic resistance induced by Trichoderma harzianum in tomato

Root colonization by selected Trichoderma isolates can activate in the plant a systemic defense response that is effective against a broad-spectrum of plant pathogens. Diverse plant hormones play pivotal roles in the regulation of the defense signaling network that leads to the induction of systemic resistance triggered by beneficial organisms [induced systemic resistance (ISR)]. Among them, jasmonic acid (JA) and ethylene (ET) signaling pathways are generally essential for ISR. However, Trichoderma ISR (TISR) is believed to involve a wider variety of signaling routes, interconnected in a complex network of cross-communicating hormone pathways. Using tomato as a model, an integrative analysis of the main mechanisms involved in the systemic resistance induced by Trichoderma harzianum against the necrotrophic leaf pathogen Botrytis cinerea was performed. Root colonization by T. harzianum rendered the leaves more resistant to B. cinerea independently of major effects on plant nutrition. The analysis of disease development in shoots of tomato mutant lines impaired in the synthesis of the key defense-related hormones JA, ET, salicylic acid (SA), and abscisic acid (ABA), and the peptide prosystemin (PS) evidenced the requirement of intact JA, SA, and ABA signaling pathways for a functional TISR. Expression analysis of several hormone-related marker genes point to the role of priming for enhanced JA-dependent defense responses upon pathogen infection. Together, our results indicate that although TISR induced in tomato against necrotrophs is mainly based on boosted JA-dependent responses, the pathways regulated by the plant hormones SA- and ABA are also required for successful TISR development.

The interaction with arbuscular mycorrhizal fungi or Trichoderma harzianum alters the shoot hormonal profile in melon plants

Arbuscular mycorrhizal fungi (AMF) and Trichoderma harzianum are known to affect plant growth and disease resistance through interaction with phytohormone synthesis or transport in the plant. Cross-talk between these microorganisms and their host plants normally occurs in nature and may affect plant resistance. Simultaneous quantification in the shoots of melon plants revealed significant changes in the levels of several hormones in response to inoculation with T. harzianum and two different AMF (Glomus intraradices and Glomus mosseae). Analysis of zeatin (Ze), indole-3-acetic acid (IAA), 1-aminocyclopropane-1-carboxylic acid (ACC), salicylic acid (SA), jasmonic acid (JA) and abscisic acid (ABA) in the shoot showed common and divergent responses of melon plants to G. intraradices and G. mosseae. T. harzianum effected systemic increases in Ze, IAA, ACC, SA, JA and ABA. The interaction of T. harzianum and the AMF with the plant produced a characteristic hormonal profile, which differed from that produced by inoculation with each microorganism singly, suggesting an attenuation of the plant response, related to the hormones SA, JA and ethylene. These results are discussed in relation to their involvement in biomass allocation and basal resistance against Fusarium wilt.

Passive smoking in babies: the BIBE study (Brief Intervention in babies. Effectiveness)

BACKGROUND

There is evidence that exposure to passive smoking in general, and in babies in particular, is an important cause of morbimortality. Passive smoking is related to an increased risk of pediatric diseases such as sudden death syndrome, acute respiratory diseases, worsening of asthma, acute-chronic middle ear disease and slowing of lung growth.The objective of this article is to describe the BIBE study protocol. The BIBE study aims to determine the effectiveness of a brief intervention within the context of Primary Care, directed to mothers and fathers that smoke, in order to reduce the exposure of babies to passive smoking (ETS).

METHODS/DESIGN

Cluster randomized field trial (control and intervention group), multicentric and open.

SUBJECT

Fathers and/or mothers who are smokers and their babies (under 18 months) that attend pediatric services in Primary Care in Catalonia.The measurements will be taken at three points in time, in each of the fathers and/or mothers who respond to a questionnaire regarding their baby's clinical background and characteristics of the baby's exposure, together with variables related to the parents' tobacco consumption. A hair sample of the baby will be taken at the beginning of the study and at six months after the initial visit (biological determination of nicotine). The intervention group will apply a brief intervention in passive smoking after specific training and the control group will apply the habitual care.

DISCUSSION

Exposure to ETS is an avoidable factor related to infant morbimortality. Interventions to reduce exposure to ETS in babies are potentially beneficial for their health.The BIBE study evaluates an intervention to reduce exposure to ETS that takes advantage of pediatric visits. Interventions in the form of advice, conducted by pediatric professionals, are an excellent opportunity for prevention and protection of infants against the harmful effects of ETS.

TRIAL REGISTRATION

Clinical Trials.gov Identifier: NCT00788996.

Utilisation of citrus compost-based growing media amended with Trichodermaharzianum T-78 in Cucumismelo L. seedling production

Two citrus composts (C1: composed of 40% citrus wastes, 20% sludge obtained from a citrus industry waste-water treatment facility and 40% green residues; C2: composed of 60% citrus wastes and 40% green residues, and no sludge) and their water extracts amended with Trichodermaharzianum T-78 (T. harzianum T-78) were assayed in order to verify if these composts could act as a partial substitute for peat-based growing media as well as enhance suppressiveness against Fusarium wilt in the production of melon (Cucumismelo L.) seedlings at greenhouse nurseries. Over a 43-day growth cycle of melon seedlings, measurements were taken of the nutriactive effect (the capability of a substrate to express additional and/or synergistic nutritional and biostimulating effects), the pathogen incidence (percentage of fresh weight loss of melon plants grown on treatments infected with Fusariumoxysporum with respect to the same treatment without inoculation of the phytopathogen) and the trend of the T.harzianum T-78 population. A nutriactive effect was observed in the tested citrus compost-based growing media (96% and 112% plant weight increase with respect to peat for C1Th and C2Th, respectively). Pathogen incidence was significantly lower in C2Th than peat (12% compared to 33%), while no difference was observed in C1Th. The T.harzianum T-78 population showed a significant decrease at the first sampling time compared to the initial quantity (from 10(6) to 10(5)CFUg(-1)), but later recovered over time. These results demonstrate that the combination of citrus compost and T.harzianum T-78 can be a viable alternative to peat and can minimise the application of chemicals necessary to control Fusarium wilt in greenhouse nurseries for melon seedling production.

Citrus compost and its water extract for cultivation of melon plants in greenhouse nurseries. Evaluation of nutriactive and biocontrol effects

Two different types of citrus composts, and their water extracts, were tested with regard to their utilisations as partial substitutes for peat in growing media for melon seedlings in greenhouse nurseries. Both compost showed higher plant growth than peat. Compost composed by citrus waste and green residue (C2) showed greater plant growth than compost obtained from the same organic matrices mentioned above further the addition of sludge obtained from citrus industry (C1). Compost C2 showed a greater auxinic effect than C1 and it was the only one that showed cytokinic effect. Both composts also demonstrated a biocontrol effect against Fusarium oxysporum for melon plants: the effects were also higher in C2 than in C1. Higher number of isolated fungi was active against F. oxysporum in compost C2, than compost C1. No different bacterial biocontrol efficacy was observed between both composts. The water extracts of both composts gave lower plant yields than their solid matrices, their relative effects being similar to those of the solid composts (C2 extract gave higher plant yields than the extract from C1). The biocontrol effects of compost water extracts followed the same trend.

Monitoring gene therapy by external imaging of mRNA: pilot study on murine erythropoietin

Gene therapy is anticipated as being an important medical development. Essential to its effectiveness is the appropriate activity (protein expression) in the expected target cells. A noninvasive diagnostic procedure of successful gene expression will be of paramount importance to validate its use or its misuse (eg, sports gene doping). Externally detectable labeled oligonucleotide hybridizing with the messenger RNA generated by the transferred gene has been proposed as a possibility to monitor successful gene therapy. The authors selected the erythropoietin gene (Epo) for a pilot study on erythropoietin protein expression in mouse muscle. Oligonucleotides of peptide nucleic acid (PNA) type capable of antisense binding to unique murine Epo-mRNA sequences were synthesized by solid phase methods, and elongated at the N-terminus with the HIV Tat (48-60) cell penetrating peptide. They were labeled with fluorescence and radioactive tags to verify penetration and longer half-life properties in Epo gene transfected C2C12 mouse muscle cells as compared with corresponding wild-type cells. Downregulation of newly expressed erythropoietin protein in such cells additionally confirmed the penetration and hybridizing properties of the selected labeled oligonucleotide. I-labeled Tat-PNAs were intravenously injected into mice that had previously received the Epo gene into the right tibialis muscle by DNA electrotransfer. Preferential accumulation of radioactivity in the transferred limb as compared with the contralateral limb was ascertained, especially for I-Tat-CTA CGT AGA CCA CT (labeled Tat-PNA 1). This study provides experimental data to support the potential use of external noninvasive image detection to monitor gene therapy. The extension of the approach to more sensitive methods for whole-body external detection such as positron emission tomography appears feasible.

Anti-EPO and anti-NESP antibodies raised against synthetic peptides that reproduce the minimal amino acid sequence differences between EPO and NESP

Erythropoietin (EPO) is a hormone that regulates red blood cell production. Recombinant human EPO (rHuEPO) and NESP (novel erythropoiesis stimulating protein) have been produced for therapeutic purposes and also to improve sports performance. The primary sequences of rHuEPO and NESP differ by just five amino acids. Due to the high homology, no antibodies that are able to discriminate between both molecules have been obtained until now. The aim of the present work was to design synthetic peptides corresponding to the sequence that differs between EPO and NESP (87-90aa), that can then be used as immunogens to develop specific rabbit polyclonal antibodies for selectively detecting EPO and NESP. Three peptides were synthesized: EPO (81-95), NESP (81-95), and NESP (86-104), and these were coupled to KLH and OVA for immunization and screening purposes, respectively. The sera obtained were tested by ELISA on synthetic peptide-OVA conjugates and purified by immunoaffinity chromatography against the corresponding synthetic peptide. The specific purified antibodies were characterized by ELISA, SDS-PAGE, and isoelectric focusing, followed by western blot. Antisera raised against EPO (81-95) recognized rHuEPO but not NESP. In contrast, anti-NESP (84-106) sera gave a specific anti-NESP response only after immunoaffinity purification on a NESP (86-91) column. An efficient strategy for generating specific antibodies against EPO and NESP can be achieved by selecting suitable synthetic peptides. The antibodies obtained are able to differentiate between rHuEPO and NESP, and may be particularly useful for screening purposes in both therapeutic and antidoping contexts.

Effect of Physical Fitness and Endurance Exercise on Indirect Biomarkers of Recombinant Growth Hormone Misuse: Insulin-Like Growth Factor I and Procollagen Type III Peptide

Serum insulin-like growth factor-I (IGF-I) and procollagen type III peptide (P-III-P) have been proposed as indirect biomarkers of rhGH misuse in sports. The purpose of the present study was to investigate concentrations of these biomarkers in athletes at different levels of physical fitness and endurance exercise. Serum total IGF-I and P-III-P were measured in 96 elite athletes of various sports along the training season; in 21 recreational athletes at baseline non-exercising conditions and in another 129 recreational athletes before and after long-distance races (10 and 21 km). No differences were evidenced for IGF-I concentrations, but statistically higher values of serum P-III-P were found in elite athletes compared to recreational ones. Among elite athletes, the specific sport did not affect serum IGF-I. However, P-III-P was statistically higher in the sport performed by the youngest athletes (rhythmic gymnastics), even after correction of the logarithm of the concentration by the reciprocal of age. Over the training season, the within-athlete variabilities of IGF-I and P-III-P in elite athletes were low (22.8 % and 21.7 %, respectively). Recreational athletes taking part in a 21 km competition race showed a significant increase in serum values of IGF-I and P-III-P immediately after the event. Exercise workload and age had a significant effect on serum concentration of P-III-P, while age alone affected IGF-I serum concentrations. Therefore, athlete's reference concentration ranges for doping detection should include subjects from as many different ages and sports as possible.

Effect of physical fitness and endurance exercise on indirect biomarkers of recombinant erythropoietin misuse

Erythropoietin (EPO) and soluble transferrin receptor (sTfR) in serum have been proposed as indirect biomarkers for the detection of recombinant human EPO (rhEPO) misuse in sport. The purpose of the present study was to investigate the influence of different levels of physical fitness, sport, different training workload during the sport season, and endurance exercise in the concentrations of these serum biomarkers for their application into mathematical models to indirectly detect rhEPO misuse. Serum EPO and sTfR concentrations were measured in 96 elite athletes of various sports along the sport season, in 21 recreational athletes at baseline (non exercising) conditions and in 129 other recreational athletes before and after long-distance races (10 and 21 km). In elite athletes, hemoglobin concentrations and percentage of reticulocytes were also measured, and indirect detection models applied. In recreational athletes, for EPO and sTfR, significant differences were only observed after the 21-km race. In baseline conditions, no differences were observed between recreational and elite athletes for EPO and sTfR. In elite athletes, individual EPO and sTfR concentrations slightly changed over the sport season, with coefficients of variation (CV) of 26.1 % and 9.0 %, respectively. Hemoglobin and reticulocytes were influenced by sport, but their individual variation over the sport season was not physiologically relevant (CV of 3.7 % and 21.3 %, respectively). When applying mathematical models for detection of rhEPO administration, only one elite athlete obtained an individual model score above the established thresholds. Physical fitness, sport and different training workload during the sport season had no substantial effect on serum EPO and sTfR concentrations, except in recreational athletes after a 21-km race. Variations observed in mathematical models to detect EPO administration were mainly due to fluctuation in hemoglobin concentrations, commonly observed in elite athletes.

Microbial community structure at different depths in disturbed and undisturbed semiarid Mediterranean forest soils

Metabolic abilities and micrfiobial community structure were investigated through three semiarid Mediterranean soils of SE Spain. The soils were (1) a Typic Calcixerept under an adult pine plantation (PP), growing on abandoned agricultural terraces; (2) a Typic Calcixeroll under a native pinewood (NP); and (3) a Typic Haploxerept covered with a grass steppe (GS). PP and NP were similar as regards their genesis, but the former used to be tilled. NP and GS were undisturbed and supported natural and seminatural vegetation, respectively. Seven samples in 10-cm depth increments were taken in triplicate along each soil profile. Community-level physiological profiles based on sole-C-source use were determined to characterize the metabolic abilities. A 16S rDNA polymerase chain reaction-denaturing gradient gel electrophoresis analysis was performed to investigate the microbial genetic structure. Plant cover and land-use history were major determinants of microbial community structure. Microbial communities residing in soils under a native pinewood, the most diverse and stable plant cover, were the most complex both metabolically and genetically. The microbial community structure distinctly changed with depth, related to the quantity and quality of total organic carbon. Both undisturbed soils showed falling gradients of metabolic and genetic complexity, which were invariably of a greater magnitude in the mature woodland than in the grass steppe. In the planted pinewood, however, the substrate-use diversity increased with depth, apparently a response to the depleted metabolic abilities within its upper layer (0-30 cm). Tilling and plant cover removal might be responsible for such a perturbation. In the same profile, molecular fingerprint patterns of the topsoil layer (0-10 cm) indicated a disturbed genetic structure that might underlie the loss of metabolic abilities. However, the genetic structure of the deeper layers of the planted and native pinewoods was not dissimilar, revealing that equivalent genetic resources perform different environmental functions under changing soil scenarios.

[Study of the extent and rate of bioavailability of ibuprofen tablets]

The extent and rate of bioavailability of ibuprofen tablets were determined in a crossover clinical trial in 18 healthy subjects of both sexes. The study was approved by the local ethical committee and was authorized by the Spanish Medicines Agency. Volunteers signed an informed consent form and were included in accordance with the standard procedures for this type of study. In two distinct sessions participants received a single 600 mg ibuprofen dose as Gelofeno(®) 600 mg tablets (Laboratorios Gelos S.L.), or as the reference formulation, Neobrufen(®) 600 mg tablets. Ibuprofen concentrations in plasma were determined immediately before (0 h) and 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12 and 24 h after drug administration. The pharmacokinetic parameters were then calculated. In all subjects, Gelofeno(®) 600 mg tablets produced plasma concentrations above the quantification limit between 15 and 30 minutes after administration, and in 9 (50%) of these subjects maximal plasma concentrations were reached at 1 h. The median t(max) was 1.25 h, and the average maximal plasma concentration was 40.7 mg/l. Gelofeno(®) 600 mg tablets were bioequivalent both in extent and in rate of bioavailability compared with the reference drug. The formulation showed good tolerability and no medication-related adverse effects were observed.

Biopesticide effect of green compost against fusarium wilt on melon plants

AIMS

The biopesticide effect of four green composts against fusarium wilt in melon plants and the effect of soil quality in soils amended with composts were assayed.

METHODS AND RESULTS

The composts consisted of pruning wastes, with or without addition of coffee wastes (3/1 and 4/1, dry wt/dry wt) or urea (1000/1, dry wt/dry wt). In vitro experiments suggested the biopesticide effect of the composts against Fusarium oxysporum, while only the compost of pine bark and urea (1000/1dry wt/dry wt) had an abiotic effect. Melon plant growth with composts and F. oxysporum was one to four times greater than in the non-amended soil, although there was no significant decrease in the level of the F. oxysporum in the soil. The addition of composts to the soil also improved its biological quality, as assessed by microbiological and biochemical parameters: ATP and hydrolases involved in the P (phosphatase), C (beta-glucosidase) and N (urease) cycles.

CONCLUSIONS

Green composts had greater beneficial characteristics, improved plant growth and controlled fusarium wilt in melon plants. These composts improve the soil quality of semi-arid agricultural soils.

SIGNIFICANCE AND IMPACT OF THE STUDY

Biotic and abiotic factors from composts have been tested as responsible of their biopesticide activity against fusarium wilt.

Evaluation of immunoassays for the measurement of insulin-like growth factor-I and procollagen type III peptide, indirect biomarkers of recombinant human growth hormone misuse in sport

Insulin-like growth factor-I (IGF-I) and procollagen type III peptide (P-III-P) have been proposed as indirect biomarkers for the detection of the misuse of recombinant human growth hormone in sport. An extended intra- and inter-laboratory validation of commercially available immunoassays was carried out. For total IGF-I, two radioimmunoassay (RIA) kits (IGF-I/RIA1, Nichols Institute Diagnostics and IGF-I/RIA2, Mediagnost) and one enzyme-linked immunosorbent assay (ELISA) (R&D) were evaluated. For P-III-P, two RIA kits (P-III-P/RIA3, Cis-bioInternational and P-III-P/RIA4, Orion Diagnostica) were studied. The intra-laboratory precision and accuracy values for all IGF-I assays were better than 15%. The IGF-I/ELISA showed the lowest limit of quantification (LOQ) and its calibration curve covered the range of concentrations found in human serum samples. Higher agreement between laboratory results was obtained for IGF-I/ELISA and IGF-I/RIA1. Low inter-technique correlation was obtained for the three assays; the only comparable results were obtained between IGF-I/ELISA and IGF-I/RIA1. For P-III-P, intra-laboratory precision and accuracy values better than 15% were obtained for both assays in almost all cases. The calibration curve for P-III-P/RIA4 covered the range of concentrations of serum samples, while 30% of the values for P-III-P/RIA3 were below the calibration sample with the lowest concentration. Inter-laboratory correlation was also higher for P-III-P/RIA4. In summary, ELISA and RIA4 were the most suitable assays for measurement of IGF-I and P-III-P, respectively, in serum samples. However, the validation studies carried out show the need for harmonization of immunoassay parameters to improve the reproducibility and comparability of results between different laboratories and in different studies.

Influence of the stabilisation of organic materials on their biopesticide effect in soils

Some organic materials have shown a suppressive effect on several diseases induced by soilborne plant pathogens. We have carried out a laboratory experiment (microcosm) to ascertain the influence of the stabilisation process of sewage sludge on it biopesticide effect when Pythium ultimum or Phytophthora sp. were introduced to soil as pathogens for pea or pepper. When P. ultimum was introduced there was a 63.8% reduction in the weight of the stems grown in the control, 47.6% in the presence of sewage sludge, but only 24.7% with compost. The same biopesticide effect was evident from the weight of the roots. The biopesticide effect was also strong when compost was used as organic amendment in the presence of Phytophthora, as could be seen from stem and shoot weight and length. The data showed that the degree of stabilisation of the organic material (compost) had a positive influence on it biopesticide effect. The changes undergone by a soil after the addition of organic materials helped to explain the biopesticide effect of the amendment. The organic treatments reduced P. ultimum and Phytophthora sp. populations.

Evaluation of immunoassays for the measurement of soluble transferrin receptor as an indirect biomarker of recombinant human erythropoietin misuse in sport

Soluble transferrin receptor (sTfR) has been proposed as an indirect biomarker of the misuse of recombinant human erythropoietin in sport. An extended validation of four commercially available immunoassays for its measurement in serum is presented. Two ELISA techniques (ELISA1: Orion Diagnostica; ELISA2: R&D Systems), an immunoturbidimetric technique (Turbid: Roche Diagnostics), and a nephelometric technique (Nephel: Dade Behring) were investigated. Intra-laboratory precision better than 3% and correct accuracies were obtained for the Turbid and Nephel techniques using autoanalysers. Slightly worse precision (but always better than 11%) and correct accuracies were also obtained in almost all cases for the two ELISA techniques. Inter-laboratory results showed higher concordances for the ELISA procedures (intraclass correlation coefficients of 0.848 for ELISA1 and 0.973 for ELISA2 which was clearly better). Inter-technique correlations were good for the four techniques with lower dispersions found for the techniques using autoanalysers, i.e. Turbid and Nephel. While Turbid and ELISA1 results (expressed in mg/l) were comparable, results obtained with Nephel were approximately 2.7 times lower. The relationship between those three techniques was maintained when compared with ELISA2, which uses different units (nmol/l). We conclude that ELISA2 and Nephel in our hands were the most suitable techniques in terms of sensitivity, precision and accuracy, and adequacy of the calibration curve for the measurement of sTfR in real serum samples. Discrepancies observed in the results obtained with the different sTfR techniques showed that different reference standards were used and harmonization is recommended in order to obtain comparable results.

Recombinant Erythropoietin and Analogues

Erythropoietin (EPO) increases the number of circulating erythrocytes and thus muscle oxygenation. The availability of the recombinant protein (rEPO) has increased the risk of its illegal use in sports, its detection being a difficult challenge. Five different hematopoietic parameters were initially chosen as indirect markers of rEPO abuse: concentration of serum EPO, concentration of serum-soluble transferrin receptors (sTFr), hematocrit, percentage of reticulocytes, and percentage of macrocytes. New models considering only hemoglobin, serum EPO concentration, and percentage of reticulocytes are simpler and seem to be more sensitive when low doses of rEPO are used. A more direct method of urine analysis (isoelectrofocusing, double blotting, and chemiluminescent detection) based on the charge differences between rEPO and endogenous EPO, related to their carbohydrate composition, provides proof of rEPO use. Furthermore, this approach permits the detection of darbepoetin, a direct analogue of EPO also known as NESP ("new erythropoiesis stimulating protein"). Recently a protein conjugate, "synthetic erythropoiesis protein" (SEP), containing precision-length, monodisperse, negatively charged polymers instead of oligosaccharides has been synthesized. Finally, EPO-mimetics are molecules capable of acting as EPO in dimerizing the EPO receptor. Two kinds of EPO-mimetics have been described: peptides and nonpeptides. The enhancement of oxygen availability to muscles by rEPO, analogues, and mimetics constitutes one of the main challenges to doping control. Major steps have already been developed for detection ofrEPO and some analogues. In the near future, the transfection to an athlete's body of genes that code for erythropoietin might be an emerging doping issue, and sports authorities have incorporated "gene doping" among the prohibited practices.

Fast screening of anabolic steroids and other banned doping substances in human urine by gas chromatography/tandem mass spectrometry

A fast and sensitive method for the comprehensive screening of anabolic agents and other banned doping substances using gas chromatography/tandem mass spectrometry (GC/MS/MS) with an external ionization ion trap mass spectrometer is presented. The method takes advantage of the resolving power of MS/MS to eliminate background interferences, thus speeding up the chromatographic analysis. For each compound, different fragmentation reactions were studied and their collision energies optimized to obtain the best sensitivity in terms of their signal-to-noise ratio (S/N). A dramatic reduction in overall analysis time was achieved compared with other common approaches. More than 50 substances could finally be monitored in less than 7.4 min with detection limits (S/N >3) lower than 0.5 ng ml(-1) for most of the compounds with special sensitivity requirements according to the International Olympic Committee (IOC). A validation procedure for qualitative analysis was performed. The selectivity of the method showed that no interfering peaks were observed at the retention time of the analytes. Good intermediate precision, below 25% for most of the compounds, and robustness were observed. The optimized method was successfully applied to analyse more than 100 real human urine samples with optimum sensitivity and specificity rates.

Effectiveness of municipal waste compost and its humic fraction in suppressing Pythium ultimum

The effect of addition of a municipal solid waste (MSW) compost and its water-soluble and humic fraction to suppress the effect of Pythium ultimum on pea plants was studied and compared with that of a chemical pesticide (metalaxyl). The biotic and abiotic characteristics of compost involved in the biocontrol effects of these materials were also evaluated. The addition into soil of whole composts and their humic fractions reduced the effect of the pathogen on pea plants, significantly reducing the number of root lesions and Pythium populations and avoiding reductions of plant growth. The greatest pathogen suppression was achieved with the chemical pesticide. However, it also caused a significant decrease in the number of nontarget bacteria and fungi and on beneficial soil microorganisms such as Trichoderma and Pseudomonas. Addition of organic amendments increased population size of nontarget and specific biocontrol microorganisms. The humic fraction showed similar results to compost. All this suggests that metalaxyl has a nonspecific effect, producing adverse effects on aspects of soil quality. This was avoided if the chemical pesticide was reduced and replaced by organic amendments such as an MSW compost or its humic fraction.

13C/12C isotope ratio MS analysis of testosterone, in chemicals and pharmaceutical preparations

The 13C/12C ratio can be used to detect testosterone misuse in sport because (semi)-synthetic testosterone is supposed to have a 13C abundance different from that of endogenous natural human testosterone. In this study, gas chromatography/combustion isotope ratio mass spectrometry (GC/C/IRMS) analysis for the measurement of the delta 13C/1000 value of testosterone from esterified forms of 13 pharmaceutical preparations, six reagent grade chemicals and three bulk materials (raw materials used in pharmaceutical proarations) obtained world-wide was investigated after applying a strong acidic solvolytic procedure. Mean delta 13C/1000 values of non esterified (free) testosterone from chemicals and bulk materials of several testosterone esters were in the range: -25.91/-32.82/1000 while the value obtained for a (semi)-synthetic, reagent grade, free testosterone was -27.36/1000. The delta 13C/1000 results obtained for testosterone from the pharmaceuticals investigated containing testosterone esters were quite homogeneous (mean and S.D. of delta 13C/1000 values of free testosterone: 27.43 +/- 0.76/1000), being the range between -26.18 and -30.04/1000. Values described above were clearly different from those reported by several authors for endogenous natural human testosterone and its main metabolites excreted into the urine in non-consumers of testosterone (delta 13C/1000 range: from -21.3 to -24.4/1000), while they were similar to those of urinary testosterone and metabolites from individuals treated with testosterone esters and testosterone precursors. This finding justifies the fact that administration of these pharmaceutical formulations led to a statistical decrease of carbon isotope ratio of urinary testosterone and its main metabolites in treated subjects.

Effect of biocontrol strains of Trichoderma on plant growth, Pythium ultimum polulations, soil microbial communities and soil enzyme activities

Five strains of Trichoderma with known biocontrol activities were assessed for their effect upon pea growth and their antagonistic activity against large Pythium ultimum inocula. The effect of Trichoderma inocula upon the indigenous soil microflora and soil enzyme activities in the presence and absence of Pythium is assessed. In the absence of Pythium, Trichoderma strain N47 significantly increased the wet shoot weight by 15% but did not significantly affect the dry weight, whilst strains T4 and N47 significantly increased the root weights by 22% and 80%) respectively. Strains TH1 and N47 resulted in significantly greater root lengths. Pythium inoculation significantly reduced the root length and the number of lateral roots and nodules, and significantly increased the root and rhizosphere soil fungal populations. Pythium inoculation significantly reduced the plant wet and dry shoot weights and significantly increased the wet and the dry shoot/root ratio. All the Trichoderma strains reduced the number of lesions caused by Pythium and increased the number of lateral roots. The effect of the Pythium on emergence and shoot growth was significantly reduced by all the Trichoderma strains except strain To10. Inoculation with Trichoderma strains TH1 and T4 resulted in significantly greater wet root weights (62% and 57%, respectively) in the presence of Pythium compared to the Pythium control. Strain N47 significantly increased the shoot/root ratio compared to the Pythium control. Inoculation with Trichoderma strains T4, T12 and N47 significantly reduced Pythium populations. Pythium increased the activity of C, N and P cycle enzymes, whilst four Trichoderma strains reduced this effect, indicating reduced plant damage and C leakage. Overall, strains T4 and N47 had the greatest beneficial characteristics, as both these strains improved plant growth in the absence of Pythium and reduced plant damage in the presence of Pythium. The dual properties of these strains improve the commercial application, giving them an advantage over single action inocula, especially in the absence of plant pathogens.

Effect of biocontrol strains of Trichoderma on plant growth, Pythium ultimum polulations, soil microbial communities and soil enzyme activities

Five strains of Trichoderma with known biocontrol activities were assessed for their effect upon pea growth and their antagonistic activity against large Pythium ultimum inocula. The effect of Trichoderma inocula upon the indigenous soil microflora and soil enzyme activities in the presence and absence of Pythium is assessed. In the absence of Pythium, Trichoderma strain N47 significantly increased the wet shoot weight by 15% but did not significantly affect the dry weight, whilst strains T4 and N47 significantly increased the root weights by 22% and 80%) respectively. Strains TH1 and N47 resulted in significantly greater root lengths. Pythium inoculation significantly reduced the root length and the number of lateral roots and nodules, and significantly increased the root and rhizosphere soil fungal populations. Pythium inoculation significantly reduced the plant wet and dry shoot weights and significantly increased the wet and the dry shoot/root ratio. All the Trichoderma strains reduced the number of lesions caused by Pythium and increased the number of lateral roots. The effect of the Pythium on emergence and shoot growth was significantly reduced by all the Trichoderma strains except strain To10. Inoculation with Trichoderma strains TH1 and T4 resulted in significantly greater wet root weights (62% and 57%, respectively) in the presence of Pythium compared to the Pythium control. Strain N47 significantly increased the shoot/root ratio compared to the Pythium control. Inoculation with Trichoderma strains T4, T12 and N47 significantly reduced Pythium populations. Pythium increased the activity of C, N and P cycle enzymes, whilst four Trichoderma strains reduced this effect, indicating reduced plant damage and C leakage. Overall, strains T4 and N47 had the greatest beneficial characteristics, as both these strains improved plant growth in the absence of Pythium and reduced plant damage in the presence of Pythium. The dual properties of these strains improve the commercial application, giving them an advantage over single action inocula, especially in the absence of plant pathogens.

Effects of food restriction on food avoidance and risk of acute poisoning of captive feral pigeons from fonofos-treated seeds

Fonofos is a highly toxic insecticide to birds that, when used as a cereal seed treatment, has caused mortality of free-living feral pigeons (Columba livia). Pigeons kept individually under ad libitum feeding conditions in the laboratory do not suffer lethal poisoning because they develop a strong avoidance response to fonofos-treated seed, which restricts consumption to below lethal levels. Two laboratory experiments were conducted to assess the role of avoidance in reducing the risk of acute poisoning of captive birds under food stress. In the first experiment, pigeons acclimatized to feed on untreated wheat seeds for 6 h/day were presented with fonofos-treated seeds for 6 h on a testing day, following normal food surplus in one experimental group (eight birds) and 6 days of deprivation in another (eight birds). In the second experiment, different pigeons were acclimatized to a feeding regime of 2 h/day and treated seeds were offered without previous restriction (eight birds) or after 6 days of food restriction in which birds were given 15% of normal intake (eight birds). In the second experiment, six birds in each experimental group were videotaped to study their feeding behavior. Survivors at the end of the testing day were killed, and all birds were dissected and analyzed to determine carcass and pectoral muscle composition. Food-stressed birds lost approximately 11% of their initial body weight during 6 days of total or partial food restriction, but they still had visible fat deposits and a high body fat content, indicating that they were in good body condition in terms of energy reserves. Consumption of treated seeds on the testing day was reduced in comparison with normal intake of untreated seed in all birds, but there were differences between experimental groups. In ad libitum-fed birds, consumption of treated seed in each experiment averaged 12% and 19% of normal levels, exposure to fonofos was below lethal levels, and no bird died. In food-stressed birds, consumption was higher (34% or 56% of normal levels for the first and second experiments, respectively) and led to the ingestion of seed containing lethal doses of pesticide. Two birds in the first experiment and three in the second died of acute poisoning within around 2 h of initial exposure. The avoidance response developed quickly in both ad libitum-fed and food-stressed birds. Feeding took place in most birds almost exclusively in the first 9 min of the testing day. Within this interval, birds of the two experimental groups stopped ingesting treated seeds around 6 min after the onset of feeding. The differences between experimental groups in consumption of treated seed were due to the higher feeding rate and effective feeding time in food-stressed birds. It is concluded that although feral pigeons under severe food stress develop an early and strong conditioned food aversion to fonofos-treated seeds, avoidance does not always prevent mortality. The need for including hunger stress as a factor in avian dietary toxicity tests to make testing conditions more representative of those experienced by wild birds is discussed. http://link.springer-ny. com/link/service/journals/00244/bibs/37n1p115.html

Fully automated analytical method for codeine quantification in human plasma using on-line solid-phase extraction and high-performance liquid chromatography with ultraviolet detection

A simple, sensitive and fully automated analytical method for the analysis of codeine in human plasma is presented. Samples are added with oxycodone, used as internal standard (I.S.), and directly loaded in the autosampler tray. An on-line sample clean-up system based on solid-phase extraction (SPE) cartridges (Bond-Elut C2, 20 mg) and value switching (Prospekt) is used. Isocratic elution improved reproducibility and allowed the recirculation of the mobile phase. A Hypersil BDS C18, 3 microns, 10 x 0.46 cm column was used and detection was done by UV monitoring at 212 nm. Retention times of norcodeine (codeine metabolite), codeine and oxycodone (I.S.) were 5.5, 6.4 and 9.1 min, respectively. Morphine was left to elute in the chromatographic front. Detection limit for codeine was 0.5 microgram l-1 and inter-assay precision (expressed as relative standard deviation) and accuracy (expressed as relative error) measured at 2 micrograms l-1 were 5.03% and 1.82%. Calibration range was 2-140 micrograms l-1.

Quantitative determination of tricyclic antidepressants and their metabolites in plasma by solid-phase extraction (Bond-Elut TCA) and separation by capillary gas chromatography with nitrogen-phosphorous detection

An analytical method for the simultaneous determination of amitriptyline, nortriptyline, imipramine, desipramine, clomipramine, and desmethylclomipramine in human plasma using promazine as internal standard is described. The method is based on a solid-phase extraction procedure using the Bond-Elut TCA columns followed by separation and detection using capillary gas chromatography with a specific nitrogen phosphorous detector (GC/NPD). Using the new extraction procedure, the problem of adsorption losses was overcome, and good recoveries were achieved for all compounds tested (>87%). Furthermore, clean extracts free of chromatographic interferences were obtained. Complete separation of underivatized, tricyclic antidepressant compounds was achieved in <11 minutes with reliable chromatographic performance. The limits of detection ranged from 1.2 to 5.8 microg/l. Calibration curves, showing good linearity, were prepared covering the therapeutic concentrations range expected (20 to 500 microg/l). The interassay precision values (RSD) ranged from 4.5% to 9.8%. It is concluded that extraction of amitriptyline, nortriptyline, imipramine, desipramine, clomipramine, and desmethylclomipramine, with Bond Elut TCA solid-phase columns followed by their detection using GC/NPD provides a sensitive and reproducible method that can be easily automated for immediate and routine analysis of clinical samples.

Direct determination of anabolic steroids in human urine by on-line solid-phase extraction/liquid chromatography/mass spectrometry

A fully automated method is presented for the determination of anabolic steroids in human urine. On line solid-phase extraction with automatic cartridge exchange is used for sample clean-up followed by an high-performance liquid chromatographic isocratic separation. A narrow-bore 5 microns reversed-phase column (250 x 2.1 mm i.d.) at a flow rate of 0.2 ml min-1 is connected to a particle beam interface linked to a single-quadrupole mass spectrometer. No derivatization is needed and normal electron impact mass spectra are obtained for a series of up to 28 steroids and metabolites. Urine samples collected following the ingestion of therapeutic doses of some of the steroids were analysed and the detection and confirmation of excreted compounds accomplished. A dramatic reduction in human intervention and overall analysis time was achieved compared with other common approaches.

Rapid and sensitive determination of zidovudine and zidovudine glucuronide in human plasma by ion-pair high-performance liquid chromatography

A rapid, simple and sensitive method is described for the simultaneous determination in human plasma of the well known antiviral agent zidovudine (AZT) and its main metabolite, zidovudine-5'-O-glucuronide (G-AZT), using a solid-phase extraction method for sample preparation and a rapid ion-pair HPLC separation method with diode-array ultraviolet detection. The method overcomes the problems experienced in other procedures because of the large difference in polarity of the two compounds and the pH-sensitive retention of G-AZT by using n-octylamine to increase the retention of the glucuronide and improve the overall chromatographic behaviour. AZT and G-AZT are eluted at 3.6 and 5 min, respectively, with 7-ethyltheophylline used as internal standard eluting at 4.2 min. Caffeine, a good marker for the elution of related compounds present in plasma, appears well before, at 2.6 min. Quantification limits were established at 0.025 and 0.050 micrograms/ml for AZT and G-AZT, respectively. The improvement in method reproducibility due to the late elution of G-AZT could be observed even at the quantification limit at which an inter-assay relative standard deviation of only 6.4% was found after 3 months of routine use of the method.

International cooperation in analytical chemistry: experience of antidoping control at the XI Pan American Games

We describe the experience of the international cooperation carried out for antidoping control at the XI Pan American Games. A temporary accreditation was granted by the International Olympic Committee to the accredited laboratory of Barcelona (Spain) to set up a Doping Control Laboratory in Havana. Two other laboratories from Mexico and Cuba contributed personnel, materials, and instrumentation. The main issues associated with the preparation and organization of the project are described. During 16 days, 741 urine samples were tested for stimulants, narcotics, anabolic steroids, beta-blockers, diuretics, cannabinoids, local anesthetics, and human chorionic gonadotropin by gas-liquid chromatography, gas chromatography/mass spectrometry, high-performance liquid chromatography, and immunoassay techniques. Analytical methodologies, quality-control strategies, and the main results are reported.

International cooperation in analytical chemistry: experience of antidoping control at the XI Pan American Games

We describe the experience of the international cooperation carried out for antidoping control at the XI Pan American Games. A temporary accreditation was granted by the International Olympic Committee to the accredited laboratory of Barcelona (Spain) to set up a Doping Control Laboratory in Havana. Two other laboratories from Mexico and Cuba contributed personnel, materials, and instrumentation. The main issues associated with the preparation and organization of the project are described. During 16 days, 741 urine samples were tested for stimulants, narcotics, anabolic steroids, beta-blockers, diuretics, cannabinoids, local anesthetics, and human chorionic gonadotropin by gas-liquid chromatography, gas chromatography/mass spectrometry, high-performance liquid chromatography, and immunoassay techniques. Analytical methodologies, quality-control strategies, and the main results are reported.

Variability of venous anatomy of rat testis: application to experimental testicular surgery

The venous drainage of the testis of the laboratory rat was observed in 31 animals. The right testicular (internal spermatic) vein drained directly into the right common iliac vein in 77.4%, and into the inferior vena cava in 22.6% of the animals. The left testicular vein drained into the left common iliac vein in all animals, but in 90.3% there was also an accessory branch of the testicular vein draining into the left renal vein. These observations suggest that in the rat the exact anatomy of the venous drainage of each testis should be identified prior to undertaking any surgical procedure on the testis where the venous vasculature plays a major role such as testicular transplantation or the creation of an experimental varicocele.

[The development of the torsion angle of the tibia-fibula unit in various age groups]

We studied the torsion angle of the tibiofibular unit in both lower legs of 1588 schoolchildren of both sexes (998 girls and 590 boys), aged between 3 and 18 years divided into four age groups. The torsion angle of the tibio-fibular unit progressively increases with age. Stable values were measured only in the 11-15 years age group. Statistically significant differences of the torsion angle between one lower limb and the other were detected in the girls of the 6-10 and 11-15 age groups, and in the boys of the 6-10 age groups.

Long-term effects of prepubertal testicular vessel ligation on testicular function in the rat

To determine the effects of unilateral testicular vein and artery ligation in the immature rat on the function and final location of the testis at adulthood, 10-day-old male rats underwent either a sham operation or unilateral ligation of these vessels of the still undescended testis. Testicular location, blood flow, size and histology as well as ventral prostate weights were measured 50 days later at adulthood. At age 60 days, it was determined that all testes were descended into the scrotum, and there were no differences in testis and ventral prostate weights, intratesticular sperm counts and mean seminiferous tubular area between the control and sham operated animals. However, there was an 18% reduction in testicular blood flow (ml. per 100 gm. per minute +/- standard error of mean) in the operated animals when compared to the sham (20.43 +/- 1.10 versus 16.69 +/- 0.74, p less than 0.02). These data indicate that although there is a slight but significant reduction in testicular blood flow at adulthood when the testicular artery and vein are ligated early in life, this diminution is not sufficient to alter the ultimate location, testicular weight and spermatogenic function of the testis. This would suggest that after ligation of the main testicular vessels to the immature testis, the collateral blood supply is able to compensate with time to allow normal growth and development of the testis. These experimental observations provide additional support for the 2-staged approach to the high undescended testis whereby the testicular vessels are initially ligated and a subsequent procedure is performed to place the undescended testis into the scrotum.

[Mucinous cystadenoma of ileocecal appendix]

We present two patients with mucinous cystadenoma and mucinous cystadenocarcinoma of the appendix, respectively. These are very uncommon lesions in that localization. We point out the lack of specificity of the term "mucocele" and also the need of strict criteria to define this type of lesions in order to establish the adequate treatment. Usually the diagnosis is not possible before surgery. The treatment consists of simple appendectomy for the benign lesions and right hemicolectomy for mucinous carcinoma.

Recovery of testicular blood flow following ligation of testicular vessels

To determine whether initial ligation of the testicular vessels of the high undescended testis followed by a delayed secondary orchiopexy is a viable alternative to the classical Fowler-Stephens procedure, a series of preliminary experiments were conducted in the rat in which testicular blood flow was measured by the 133xenon washout technique before, and 1 hour and 30 days after ligation of the vessels. In addition, testicular histology, and testis and sex-accessory tissue weights were measured in 6 control, 6 sham operated and 6 testicular vessel ligated rats 54 days after vessel ligation. The data demonstrate that ligation and division of the testicular blood vessels produce an 80 per cent decrease in testicular blood flow 1 hour after ligation of the vessels. However, 30 days later testis blood flow returns to the control and pre-treatment value. There were no significant changes in testis or sex-accessory tissue weights 54 days after vessel ligation. Histologically, 4 of the surgically operated testes demonstrated necrosis of less than 25 per cent of the seminiferous tubules while 1 testis demonstrated more than 75 per cent necrosis. The rest of the tubules in all 6 testes demonstrated normal spermatogenesis. From this study we conclude that initial testicular vessel ligation produces an immediate decrease in testicular blood flow but with time the collateral vessels are able to compensate and return the testis blood flow to its normal pre-treatment value. These preliminary observations lend support for the concept that initial ligation of the testicular vessels followed by a delayed secondary orchiopexy in patients with a high undescended testis may be a possible alternative to the classical Fowler-Stephens approach.

Corticosteroid-binding globulin in depression

We undertook this study to evaluate the role of plasma free and total cortisol, and corticosteroid-binding globulin (CBG) in depression. Plasma was collected from 15 drug-free depressed patients and 15 age and sex-matched control subjects at 0900 and 2300 and at 1600 following an oral dose of dexamethasone. Depressed patients had elevated concentrations of both free and total cortisol at all time points studied. The binding capacity and affinity of plasma CBG for cortisol was similar in both groups at all times studied. No differences in CBG measures were noted if the depressed subjects were divided into elderly or younger subjects and dexamethasone suppression test (DST) suppressors or non-suppressors.