Transcriptomic analysis and molecular docking reveal genes involved in the response of Aedes aegypti larvae to an essential oil extracted from Eucalyptus

BACKGROUND

Aedes aegypti (L.) is an urban mosquito, vector of several arboviruses that cause severe diseases in hundreds of million people each year. The resistance to synthetic insecticides developed by Ae. aegypti populations worldwide has contributed to failures in vector control campaigns, increasing the impact of arbovirus diseases. In this context, plant-derived essential oils with larvicidal activity could be an attractive alternative for vector control. However, the mode of action and the detoxificant response of mosquitoes to plant derived compounds have not been established, impairing the optimization of their use.

METHODS AND FINDINGS

Here we compare gene expression in Ae. aegypti larvae after 14 hrs of exposure to Eucalyptus camaldulensis essential oil with a control group exposed to vehicle (acetone) for the same lapse, by using RNA-Seq. We found differentially expressed genes encoding for cuticle proteins, fatty-acid synthesis, membrane transporters and detoxificant related gene families (i.e. heat shock proteins, cytochromes P450, glutathione transferases, UDP-glycosyltransferases and ABC transporters). Finally, our RNA-Seq and molecular docking results provide evidence pointing to a central involvement of chemosensory proteins in the detoxificant response in mosquitoes.

CONCLUSIONS AND SIGNIFICANCE

Our work contributes to the understanding of the physiological response of Ae. aegypti larvae to an intoxication with a natural toxic distilled from Eucalyptus leafs. The results suggest an involvement of most of the gene families associated to detoxification of xenobiotics in insects. Noteworthy, this work provides important information regarding the implication of chemosensory proteins in the detoxification of a natural larvicide. Understanding the mode of detoxification of Eucalyptus distilled compounds could contribute to their implementation as a tool in mosquito control.

Insecticide Resistance Mechanisms in Triatoma infestans (Reduviidae: Triatominae): The Putative Role of Enhanced Detoxification and Knockdown Resistance (kdr) Allele in a Resistant Hotspot From the Argentine Chaco

Chagas disease affects around 6 million people in the world, and in Latin America, it is mainly transmitted by the kissing bug. Chemical control of the vector with pyrethroid insecticides has been the most frequently used tool to reduce the disease incidence. Failures of field control have been detected in areas of the Argentinian Gran Chaco that correlate with high levels of insecticide resistance. Here, we provide evidence of the mechanisms involved in the resistance to insecticides of field populations of T. infestans from General Güemes Department (Chaco Province, Argentina). The biochemical analysis suggests the increase in the activity of the degradative enzymes P450 oxidases and esterases as a minor contributive mechanism in low-resistance populations. The molecular study revealed high frequencies of the kdr L925I mutation at the voltage-gated sodium channel as responsible for the high resistance ratios detected. This knowledge contributes to the generation of comprehensive vector control strategies that reduce the incidence of the disease.

Orcokinin neuropeptides regulate ecdysis in the hemimetabolous insect Rhodnius prolixus

To grow and develop insects must undergo ecdysis. During this process, the individual sheds the old cuticle to emerge as the following developmental stage. During ecdysis, different programed behaviors are regulated by neuropeptidergic pathways. In general, components of these pathways are better characterized in crustacean and holometabolous insects than in hemimetabola. In insects, the orkoninin gene produces two different neuropeptide precursors by alternative splicing: orcokinin A and orcokinin B. Although orcokinins are well conserved in insect species, their physiological role remains elusive. Here we describe a new splicing variant of the orcokinin gene in the hemimetabolous triatomine Rhodnius prolixus. We further analyze the expression pattern and the function of the alternatively spliced RhoprOK transcripts by means of immunohistochemistry and RNAi-mediated gene silencing. Our results indicate that orkoninis play an essential role in the peptidergic signaling pathway regulating ecdysis in the hemimetabolous insect Rhodnius prolixus.

Neuropeptidomics in Triatoma infestans. Comparative transcriptomic analysis among triatomines

Chagas' disease, affecting up to 6-7 million people worldwide, is transmitted to humans through the feces of triatomine kissing bugs. From these, Rhodnius prolixus, Triatoma dimidiata, Triatoma infestans and Triatoma pallidipennis are important vectors distributed throughout the Latin American subcontinent. Resistance to pyrethroids has been developed by some triatomine populations, especially T. infestans, obstructing their control. Given their role in the regulation of physiological processes, neuroendocrine-derived factors have been proposed as a source of molecular targets for new-generation insecticides. However, the involvement of neuropeptides in insecticide metabolism and resistance in insects has been poorly studied. In the present work, the sequences of 20 neuropeptide precursor genes in T. infestans, 16 in T. dimidiata, and 13 in T. pallidipennis detected in transcriptomic databases are reported, and a comparative analysis in triatomines is presented. A total of 59 neuropeptides were validated by liquid chromatography-tandem mass spectrometry in brain and nervous ganglia from T. infestans, revealing the existence of differential post-translational modifications, extended and truncated forms. The results suggest a high sequence conservation in some neuropeptide systems in triatomines, whereas remarkable differences occur in several others within the core domains. Comparisons of the basal expression levels for several neuropeptide precursor genes between pyrethroid sensitive and resistant population of T. infestans are also presented here, in order to introduce a proof of concept to test the involvement of neuropeptides in insecticide resistance. From the precursors tested, NVP and ITG peptides are significantly higher expressed in the resistant population. To our knowledge, this is the first report to associate differential neuropeptide expression with insecticide resistance. The information provided here contributes to creating conditions to widely extend functional and genetic studies involving neuropeptides in triatomines.

DEVELOPMENT OF A RAPID PROCEDURE TO ANALYSE Pu, Am AND 90Sr IN EMERGENCY URINE BIOASSAY IN CIEMAT BIOELIMINATION LABORATORY: METHOD VALIDATION BY EMERGENCY BIOASSAY INTERCOMPARISON EXERCISES

After a radiological or nuclear incident, it is necessary to give a prompt response and to know the number of persons exposed to internal contamination, to evaluate the contamination levels in each person and even and to identify the radionuclides involved. In vitro laboratories routine monitoring measurements employed to quantify (90)Sr and actinides in urine require radiochemical separation and long counting time, which implies a minimum of 1 or 2 weeks to obtain the results, respectively. In this work, rapid radiochemical separation method applied directly to urine samples is presented. It is based on minimal sample preparation, without co-precipitation phase, using extraction resin columns and vacuum box technology. Pu isotopes and (241)Am are isolated, electrodeposited and measured by alpha spectrometry, whereas (90)Sr is measured by liquid scintillation counting. Finally, results of the participation in European Radiation Dosimetry Group intercomparison on Emergency Bioassay exercise and Bundesamt für Strahlenschutz exercise validate the accuracy of this procedure.

THE CHALLENGE OF CIEMAT INTERNAL DOSIMETRY SERVICE FOR ACCREDITATION ACCORDING TO ISO/IEC 17025 STANDARD, FOR IN VIVO AND IN VITRO MONITORING AND DOSE ASSESSMENT OF INTERNAL EXPOSURES

The accreditation of an Internal Dosimetry Service (IDS) according to ISO/IEC 17025 Standard is a challenge. The aim of this process is to guarantee the technical competence for the monitoring of radionuclides incorporated in the body and for the evaluation of the associated committed effective dose E(50). This publication describes the main accreditation issues addressed by CIEMAT IDS regarding all the procedures involving good practice in internal dosimetry, focussing in the difficulties to ensure the traceability in the whole process, the appropriate calculation of detection limit of measurement techniques, the validation of methods (monitoring and dose assessments), the description of all the uncertainty sources and the interpretation of monitoring data to evaluate the intake and the committed effective dose.

RETROSPECTIVE METHOD VALIDATION AND UNCERTAINTY ESTIMATION FOR ACTINIDES DETERMINATION IN EXCRETA BY ALPHA SPECTROMETRY

Two essential technical requirements of ISO 17025 guide for accreditation of testing and calibration laboratories are the validation of methods and the estimation of all sources of uncertainty that may affect the analytical result. Bioelimination Laboratory from Radiation Dosimetry Service of CIEMAT (Spain) uses alpha spectrometry to quantify alpha emitters (Pu, Am, Th, U and Cm isotopes) in urine and faecal samples from workers exposed to internal radiation. Therefore and as a step previous to achieving the ISO 17025 accreditation, the laboratory has performed retrospective studies based on the obtained results in the past few years to validate the analytical method. Uncertainty estimation was done identifying and quantifying all the contributions, and finally the overall combined standard uncertainty was calculated.

The role of coagulation disorders in patients with retinal vein occlusion

BACKGROUND

The role of a hypercoagulable state in the pathogenesis of retinal vein occlusion (RVO) has not been conclusively established.

AIM

To analyse the prevalence of thrombophilia in RVO.

DESIGN

Prospective case-control study.

METHODS

All the patients diagnosed with RVO were referred to an Internal Medicine clinic and compared with sex- and age-matched individuals from a population-based cohort. Demographic, clinical and laboratory variables (including a thrombophilia panel) were analysed.

RESULTS

One hundred and seventy patients (93 men and 77 women; 68 ± 11 years) and 170 controls (80 men and 90 women; 67 ± 10 years) were included. RVO was peripheral in 113 cases. Genetic thrombophilia was detected in 13% of patients. Acquired thrombophilia was observed in 10% of cases and 4.7 % of controls (P < 0.01). Sixty-three percent of cases and 24.6% of controls had serum hyperhomocysteinemia (odds ratio [OR] 5.2, IC 95% 2.7-10.1; P < 0.0001) : In RVO patients aged <50 years (n = 11), 36.4% had genetic thrombophilia (P = 0.04), as well as 50% of those without vascular risk factors (n = 18; P = 0.01). Forty-one (24%) patients with RVO received antiplatelet agents and 13 (7.6%) were on anticoagulants due to preexistent atrial fibrillation.

CONCLUSIONS

We suggest that, in patients with RVO, hyperhomocysteinemia and antiphospholipid syndrome should be ruled out. Moreover, a study of genetic thrombophilia should only be considered in those aged <50 years or without cardiovascular risk factors. Antiplatelet therapy with aspirin is probably the treatment of choice of RVO, to reduce the overall vascular risk. Anticoagulation should only be considered in patients with high-risk thrombophilia.

Identification of G protein coupled receptors for opsines and neurohormones in Rhodnius prolixus. Genomic and transcriptomic analysis

The importance of Chagas disease motivated the scientific effort to obtain the complete genomic sequence of the vector species Rhodnius prolixus, this information is also relevant to the understanding of triatomine biology in general. The central nervous system is the key regulator of insect physiology and behavior. Neurohormones (neuropeptides and biogenic amines) are the chemical messengers involved in the regulation and integration of neuroendocrine signals. In insects, this signaling is mainly mediated by the interaction of neurohormone ligands with G protein coupled receptors (GPCRs). The recently sequenced R. prolixus genome provides us with the opportunity to analyze this important family of genes in triatomines, supplying relevant information for further functional studies. Next-generation sequencing methods offer an excellent opportunity for transcriptomic exploration in key organs and tissues in the presence of a reference genome as well as when a reference genome is not available. We undertook a genomic analysis to obtain a genome-wide inventory of opsines and the GPCRs for neurohormones in R. prolixus. Furthermore, we performed a transcriptomic analysis of R. prolixus central nervous system, focusing on neuropeptide precursor genes and neurohormone and opsines GPCRs. In addition, we mined the whole transcriptomes of Triatoma dimidiata, Triatoma infestans and Triatoma pallidipennis - three sanitary relevant triatomine species - to identify neuropeptide precursors and GPCRs genes. Our study reveals a high degree of sequence conservation in the molecular components of the neuroendocrine system of triatomines.

Examining Mechanisms of Pyrethroid Resistance in Eggs of Two Populations of the Chagas' Disease Vector Triatoma infestans (Hemiptera: Reduviidae)

Chagas disease is a zoonosis transmitted to man by blood-sucking triatomine bugs found in the Americas. Triatoma infestans (Klug, 1834) is the main vector of Chagas' disease in Argentina. The control of this illness relies heavily on vector control through the use of insecticide. However, resistance to pyrethroid insecticides associated with ineffective field treatments has been increasingly reported in T. infestans from Argentina and Bolivia. There are few reports on the expression and causes of resistance in eggs of resistant populations, and even fewer studies on insecticide resistance throughout embryonic development. In this study, we explore the biochemical and molecular mechanisms potentially associated with the deltamethrin resistance assessed in the developing eggs of the Argentinean (Campo Largo) and Bolivian (Entre Ríos) T. infestans populations.We found measurable activity of monooxigenases and pyrethroid esterases throughout embryonic development. The pyrethroid esterase activity grew steadily throughout development in all the studied populations and was highest in eggs 12 d old. Mean enzyme activity increased from 13.6 to 16.3 and 22.2 picomol 7-hydroxycoumarin/min (7-OHC) in eggs of 4-, 7-, and 12 d old from the susceptible reference bug colony. Mean activity of resistant populations increased from 16.0 to 25.9 picomol 7-OHC/min in eggs of 4- to 12 d old in Entre Ríos population, and from 15.9 to 28.9 picomol 7-OHC/min in Campo Largo population. Molecular analysis of susceptible and resistant developing eggs detected L1014F mutation in both resistant populations, but no L925I mutation was found in any of the studied populations.Higher esterase activity and L1014F presence justify the resistance to pyrethroid throughout developing eggs of both studied T. infestans populations. The description of resistance profiles including resistance mechanisms involved will allow a rational design of campaigns for the control of Chagas disease transmission.

Serum uric acid is associated with quantitative ultrasound parameters in men: data from the Camargo cohort

This study analyzes the association between serum uric acid levels and heel quantitative ultrasound (QUS) parameters in men aged 50 or more from the Camargo cohort. We found that higher serum uric acid levels are positively associated with all QUS measurements, suggesting a better bone quality in men with elevated serum uric acid values.

INTRODUCTION

Higher serum uric acid concentrations have been associated with higher bone mineral density and lower prevalence of fractures. However, there are no studies that have assessed the bone quality properties in Caucasians. Therefore, we have analyzed the association between quantitative ultrasound (QUS) and serum uric acid levels in adult men from a population-based cohort.

METHODS

A total of 868 men older than 50 were recruited from a larger cohort (Camargo Cohort) after excluding those with any known condition or drug treatment with a possible influence on bone metabolism, or those with a previous diagnosis of gout or taking hipouricemic agents. Bone turnover markers (PINP and CTX), 25OH-vitamin D and PTH levels were measured by electrochemiluminiscence. BMD was determined by DXA, and heel QUS with a gel-coupled device.

RESULTS

Lumbar, femoral neck and total hip BMD was significantly higher in men with higher serum uric acid levels. QUS parameters were also significantly higher in men with high uric acid levels than those with lower values, and increased continuously across quartiles after adjustment for confounding variables. In multiple regression analysis, serum uric acid was significantly associated with all QUS parameters. Finally, men with serum acid levels above median showed higher values in all the QUS parameters than men with lower values.

CONCLUSIONS

Higher serum uric acid levels in men older than 50 years are positively associated with QUS parameters. These data might suggest a better bone quality in men with elevated serum uric acid values.

Breed, slaughter weight and ageing time effects on physico-chemical characteristics of lamb meat

The effects of breed, slaughter weight and ageing time on the meat quality of the three most important Spanish breeds were considered. Two hundred and twenty-five lambs of Rasa Aragonesa-local meat breed-, Churra-local dairy breed- and Spanish Merino were used. Animals (75 of each breed) were slaughtered at three different live weights (10-12, 20-22 or 30-32 kg), and the meat was aged for 1, 2, 4, 8 or 16 days. The meat pH, colour, amount of haem pigments, intramuscular fat, moisture, hydroxyproline content and sarcomere length were measured at 24 h post-mortem. Meat texture was measured by compression after each ageing time. The pH of the samples ranged from 5.50 to 5.58. Meat colour varied with breed and slaughter weight (P⩽0.01), the M. longissimus thoracis was lighter in the youngest animals and in the Churra breed and redder in Merinos. Intramuscular fat increased and moisture decreased for heavier lambs. Differences in collagen were associated with breed (P⩽0.01); total and insoluble collagen contents were higher in the Churra breed. Sarcomere length was only slightly affected by slaughter weight. Meat from the Churra breed had the highest values at high levels of compression. Suckling lambs (10-12 kg) had greater myofibrillar toughness than heavier lambs and ageing strongly influenced myofibrillar tenderness.

Bilateral Leydig Cell Tumor in a Six-Year-Old Intersex Goat Affected by Polled Intersex Syndrome

A 6-year-old, sterile, Blanca Celtibérica breed adult doe was referred to our faculty. The doe had external female genitalia, a short anogenital distance, and normally shaped udders. Masculinization signs in the head shape and male behavior were also noted at the time of referral. Genetic analysis demonstrated normal 2n = 60 XX karyotype and an absence of the sex-determining region Y (SRY). The animal was homozygous for a DNA deletion responsible for the Polled Intersex Syndrome (PIS). A uterus and 2 uterine horns were present at the postmortem examination. Gartner's ducts and degenerated Wolffian derivatives persisted. There were 2 intra-abdominal testicle-like structures, one of which consisted of epididymal and deferent ducts. An advanced Leydig cell tumor, resulting in almost total destruction of the intratesticular structures, was also observed. Leydig cell tumors usually produce testosterone. Thus, these histologic findings are compatible with the evident virilization.

Caracterización de la canal y la carne de la raza bovina menorquina

Se evaluaron las características de la canal y de la carne de los animales de la raza bovina Menorquina como paso previo para la creación de una marca de calidad. Se utilizaron 8 machos de un año de edad. Las variables estudiadas fueron: conformación, engrasamiento, morfometría de la canal, pH, color, textura y valoración sensorial. La canal resultó mejor que la de la Frisona, su competidora directa en la isla. La raza Menorquina presentó valores bajos en el análisis instrumental de la textura, siendo bien valorada sensorialmente.

Phylogenetic relationships among Spanish goats breeds

We partially sequenced the mitochondrial hypervariable region 1 (HVR1) in 60 goats belonging to six Spanish breeds. The analysis of these and previously published sequences reveals a weak phylogeographical structure in the Iberian Peninsula breeds. Individuals from a single breed did not group into a single cluster. Furthermore, individuals from different breeds often shared single phylogenetic tree branches after UPGMA analysis. This could reflect the non-existence of breed isolation because of traditional seasonal pastoralism and annual long-distance migrations. Three goats belonging to the C maternal lineage were found, demonstrating a wider than previously thought distribution for this lineage.

Preparation of 2-mercaptobenzothiazole-derivatized mesoporous silica and removal of Hg(ii) from aqueous solution

Mesoporous silicas (SBA-15 and MCM-41) have been functionalized by two different methods. Using the heterogeneous route the silylating agent, 3-chloropropyltriethoxysilane, was initially immobilized onto the mesoporous silica surface to give the chlorinated mesoporous silica Cl-SBA-15 or Cl-MCM-41. In a second reaction a multifunctionalized N,S donor compound (2-mercaptobenzothiazol) was incorporated to obtain the functionalized silicas denoted as MBT-SBA-15-Het and MBT-MCM-41-Het. Using the homogeneous route, the functionalization was achieved via the one step reaction of the mesoporous silica with an organic ligand containing the chelating functions, to give the modified mesoporous silicas denoted as MBT-SBA-15-Hom or MBT-MCM-41-Hom. The functionalized mesoporous silicas were employed as adsorbents for the regeneration of aqueous solutions at pH 6 contaminated with Hg(ii) at room temperature. Results obtained indicate that mercury adsorption was higher in the mesoporus silicas prepared by the homogeneous method, and the maximum adsorption value (0.24 +/- 0.02 mmol Hg(ii) g(-1)) was obtained for MBT-SBA-15-Hom. The chemically stability in acid medium of the functionalized silicas, possibility its regeneration washing with concentrate HCl, resulting in the reuse of the adsorbent material for several cycles.

Guidance on individual monitoring programmes for radioisotopic techniques in molecular and cellular biology

The radioisotope techniques used in molecular and cellular biology involve external and internal irradiation risk. The personal dosemeter may be a reasonable indicator for external irradiation. However, it is necessary to control the possible internal contamination associated with the development of these techniques. The aim of this project is to analyse the most usual techniques and to establish programmes of internal monitoring for specific radionuclides (32P, 35S, 14C, 3H, 125I and 131I). To elaborate these programmes it was necessary to analyse the radioisotope techniques. Two models have been applied (NRPB and IAEA) to the more significant techniques, according to the physical and chemical nature of the radionuclides, their potential importance in occupational exposure and the possible injury to the genetic material of the cell. The results allowed the identification of the techniques with possible risk of internal contamination. It was necessary to identify groups of workers that require individual monitoring. The risk groups have been established among the professionals exposed, according to different parameters: the general characteristics of receptor, the radionuclides used (the same user can work with one, two or three radionuclides at the same time) and the results of the models applied. Also a control group was established. The study of possible intakes in these groups has been made by urinalysis and whole-body counter. The theoretical results are coherent with the experimental results. They have allowed guidance to individual monitoring to be proposed. Basically, the document shows: (1) the analysis of the radiosotopic techniques, taking into account the special containment equipment; (2) the establishment of the need of individual monitoring; and (3) the required frequency of measurements in a routine programme.

Critical points in the transport of cattle to slaughter in Spain that may compromise the animals' welfare

The welfare of cattle depends greatly on the attitudes and training of stockpersons and on the availability of appropriate facilities. Much has been learned about stress during transport, but less attention has been paid to identifying and correcting critical points, partly because they vary widely both nationally and internationally. A survey of cattle transport in Spain was made in an effort to determine which parts of the process most compromised the animals' welfare. Data were collected on the methods and facilities for loading and unloading, transport times, types of vehicle and slaughterhouse practices. Loading facilities were adequate and loading times generally short but some farms continued to use an electric goad and weather-proofing was generally poor. The average journey time within Spain was three-and-a-half hours, but many trips were made abroad (especially to Italy), few drivers received specific training courses and the types and quality of vehicles varied widely. The average unloading time was very short but the animals were not always inspected for injuries or dirtiness. Lairage times were normally more than eight hours but few slaughterhouses had air-conditioning equipment to prevent excessive heat or dehydration. Almost all stockpersons avoided either regrouping animals or housing or transporting animals at high densities.

A validated flame AAS method for determining magnesium in a multivitamin pharmaceutical preparation

A rapid method for determining magnesium in a multivitamin pharmaceutical preparation has been validated. This element is analysed by flame atomic absorption spectrometry after dissolution of the sample in acid medium. Linearity, precision, accuracy and robustness of the method have been determined, and detection and quantification limits have been calculated. Linearity of response was verified for concentrations ranging from 0.05 to 0.40 mg x l(-1) of magnesium. Correlation coefficient of the calibration straight lines was always > or =0.9999. Repeatability of the method gave relative standard deviation (R.S.D.) of 0.6%. Reproducibility of the method calculated after analysis of samples by the same analyst in different days (day-to-day fluctuation) and by two different analysts in different days (analyst-to-analyst fluctuation) gave relative standard deviation of 1.1 and 1.6%, respectively. Mean recoveries of magnesium obtained after spiking sample placebos with increasing amounts of magnesium chloride ranged from 98.9 to 100.8%. Robustness of the method evaluated by changing different experimental conditions under which analyses were performed, gave relative standard deviation from 0.2 to 0.5%. Limits of detection and quantification were 3.8 and 7.0 microg of Mg per gram of sample, respectively. Results show the suitability of the method for direct measurement of magnesium in a water-soluble multivitamin pharmaceutical preparation.

Vitamin B1 and B6 retention in milk after continuous-flow microwave and conventional heating at high temperatures

The effect of continuous-flow microwave treatment at high temperatures on the retention of vitamins B1 and B6 in raw milk with different fat content was evaluated. Results were compared with those obtained using a conventional system (tubular heat exchanger) with the same heating and cooling phases. Heat treatment of whole (3.4% fat) and skim (0.5% fat) milk at 90 degrees C produced no losses of vitamin B1 or vitamin B6 (pyridoxamine and pyridoxal). However, at 110 and 120 degrees C, while vitamin B1 content of milk remained constant, pyridoxamine increased (4 to 5% and 9 to 11%, respectively) and pyridoxal decreased (5 to 6% and 9 to 12%, respectively). Under the assayed conditions, no differences were observed between the content of these vitamins in conventionally and continuous-flow microwave-treated milk.

Determination by capillary electrophoresis of total and available niacin in different development stage of raw and processed legumes: comparison with high-performance liquid chromatography

The available and total niacin evolution during maturation of yellow pea lupine (Lupinus luteus L., cv. Juno), pea (Pisum sativum L., cv. Ergo), faba bean (Vicia faba sp. minor Harz, cv. Tibo) and in germinated and high-pressure heated peas (Pisum sativum L., cv. Esla) have been determined by capillary electrophoresis (CE). The results have been compared with those obtained by high-performance liquid chromatography (HPLC). The values obtained by CE were similar to those obtained by HPLC. Maturation of seeds significantly reduced the available and total niacin content in legumes. The available/total niacin ratio during seed maturation depends on the type of legume. In faba beans and peas, a reduction was observed which was more pronounced in the case of peas. For lupine seeds, the ripening produced an increase (34%) in the available/total niacin ratio 50 days after flowering (DAF). Pea germination produced an overall increase in available and total niacin content although the available/total niacin ratio decreased. High pressure heating of pea yielded an increase in the available niacin content and available/total niacin ratio but the total niacin content did not change.

Determination of iron and molybdenum in a dietetic preparation by flame AAS after dry ashing

Methods for the determination of iron and molybdenum in a dietetic pharmaceutical preparation by flame atomic absorption spectrometry (FAAS) after dry ashing at 600 degrees C have been validated. Linearity, precision, accuracy, detection and quantification limits, specificity and robustness have been determined. Linearity of response was verified for concentrations ranging from 0.50 to 4.00 mg l(-1) of iron and 1.00 to 6.00 mg l(-1) of molybdenum. Precision of the methods, performed under conditions of repeatability and reproducibility, gave relative standard deviations of 0.4 and 1.1%, respectively, for the iron determination and of 1.0 and 6.5%, respectively, for the molybdenum determination. Mean recoveries determined after spiking dietetic preparation placebos ranged from 97.1 to 102.6% for iron and 95.2 to 102.9% for molybdenum. The limit of detection for iron was 126 microg g(-1) and for molybdenum 129 microg l(-1). Quantification limits were 420 and 433microg l(-1) for iron and molybdenum, respectively. No interference in the iron and molybdenum determination due to other components present in the dietetic capsules was found. Day-to-day and analyst-to-analyst variability was less than 1.1% for iron and 4.5% for molybdenum. Results show the suitability of the method for measurement of iron and molybdenum in a complex matrix sample such as a dietetic pharmaceutical preparation.

Nutritional evaluation of ethanol-extracted lentil flours

Lentil flours were extracted with 80% ethanol at 25 and 50 degrees C for 1, 2, or 3 h. The various nitrogen fractions, soluble carbohydrates, three amino acids (Lys, His, and Tyr), available lysine, protein digestibility, and vitamins B(1) and B(2) were analyzed to evaluate the effect of extraction. Extraction resulted in an increase in the total nitrogen content of the extracted flours, with extraction temperature affecting the nature of the nitrogen (protein or nonprotein) content. There was also a large reduction in the oligosaccharides of the raffinose family, although the effect of temperature was appreciable only in the case of stachyose. There was hardly any effect on the concentrations of the amino acids analyzed or on protein digestibility; however, a positive correlation between protein digestibility and the available lysine was recorded in the samples. The vitamin B(1) and B(2) contents underwent variable decreases depending on extraction temperature.

Determination of lumbar muscular activity in helicopter pilots: a new approach

BACKGROUND

Discomfort in the lumbar region is a frequent complaint of helicopter pilots. Two factors that helicopter crewmembers relate to back pain are exposure to vibration and poor posture during flight, because during flight the seat and controls force the pilot to adopt an asymmetric posture. Repeated exposure to these adverse flight conditions could cause pathological changes in the spine. The purpose of this study was to compare right and left sided lumbar muscular activity in helicopter pilots under real flight conditions, using surface electromyography (SEMG) to demonstrate the effects of asymmetrical posture on the musculoskeletal system. An attempt was also made to correlate lumbar muscular activity with environmental factors and such variables as type of flight, type of helicopter, duration of flight, age, physical fitness, and height.

METHODS

Right- and left-sided lumbar electrical activity were measured using two-channel SEMG during 35 flights in 2 types of helicopter and a cockpit mock-up.

RESULTS

There was a statistically significant increase in right-sided lumbar activity when related to the duration of flight.

CONCLUSIONS

The data showed that when the pilot used the manual controls during flight, he did not maintain a symmetrical posture and contracted one side more than the other. We think the relationship between the greatest right-sided contraction and flight duration is due to maintaining an asymmetric posture over a long period. We also noted a tendency towards greater right lumbar musculature activity in older pilots.

Indirect monitoring of internal exposure in the decommissioning of a nuclear power plant in Spain

The experimental procedure used for the indirect measurement of internal exposure of workers involved in the first step of the decontamination of a nuclear power plant which is being decommissioned is presented. The establishment of decontamination and decommissioning programs is currently in progress at the nuclear power plant and monitoring procedures to assess workers' exposure have also been implemented. Due to the presence of transuranics, the monitoring program includes the analysis of excreta samples. An analytical method for the determination of plutonium (Pu) and americum (Am) in urine samples was developed. The radiochemical separation is based on the coprecipitation of transuranics and sequential isolation of Pu and Am by anion exchange and extraction chromatography. Finally, electrodeposited sources are prepared and counted by alpha-spectrometry.

[Ataxia telangiectasia: review of 13 new cases]

We report the review of 13 patients who were diagnosed of ataxia telangiectasia before 6 years of age. All of them manifested cerebelous ataxia, oculocutaneus telangiectasias (11), sinopulmonary infections (9), dystonia (9), oculomotor apraxia (9) and Burkitt linfoma (1). We analyse the most common presentation of the disease in early stages and the complementary studies performed. The prompt diagnosis allow us a better control of infections, malignant process and finally the possibility of genetic counseling.

Invasive maxillary aspergillosis after dental extraction. Case report and review of the literature

Paranasal sinus aspergillosis has usually been considered a rare disease, but it is seen more frequently in both immunocompromised and immunocompetent persons. Invasion may reach the sinuses via the nose or from the mouth after dental procedures. Even though the infection is usually limited to one or more sinuses, it may in certain cases extend to vascular or intracranial structures with a fatal outcome. In these cases, aggressive treatment is justified. We report a case of maxillary sinus aspergillosis that developed after dental extraction. Attention should be given to this possibility even after an apparently uncomplicated dental extraction.

Polymorphous low-grade adenocarcinoma of the oral cavity: a report of 14 cases

The clinicopathologic characteristics of 14 new cases of low-grade polymorphous adenocarcinoma of the oral cavity are presented. Tumors were located in the palate in 10 cases, and in one case each in the base of the tongue, buccal mucosa, tonsil, and retromolar pad. Nine cases were previously diagnosed as other categories of benign and malignant tumors. The tumors were classified as terminal-duct and low-grade papillary adenocarcinomas. Three cases developed local recurrence and four cases had lymph nodes metastasis, two on admission and two during the course of the disease. Two of the local recurrences and all cases with metastasis were salvaged with further surgery with or without irradiation. Recurrence and metastasis occurred only with the terminal duct adenocarcinoma. There was no death related to the neoplasm, although one patient is living with advanced disease.

Temporalis myofascial flap for maxillofacial reconstruction

To date, the temporalis myofascial flap has been used only to a limited extent for reconstruction in the maxillofacial region. Experience gained with 26 temporalis flaps in reconstruction of tissue defects in the periorbital region, skull base, maxilla, and oral cavity is presented. Only one patient developed total necrosis of the flap; significant necrosis did not occur in any other patient. The anatomy of the flap and surgical technique are briefly presented.

Acinic cell carcinoma of the salivary glands. A review of 20 new cases

Twenty patients with acinic cell carcinoma of the salivary glands are presented. Seventeen tumours were located in the parotid and three in minor salivary glands, one being considered intraosseous. According to the growth patterns, they were classified as solid-acinar in 8 patients, microcystic in 5 patients, follicular in 3 patients and papillocystic in 4 patients. 9 cases were considered high grade malignant tumours and among the 11 well-differentiated, 2 suffered dedifferentiation in local recurrences. Local recurrence appeared in 9 cases. Three cases had nodal disease on admission while 5 developed this during the course of the disease. Distant metastasis appeared in 2 cases. Local recurrence and nodal disease correlated with the degree of differentiation and state of the margins in the surgical specimen. We recommend an aggressive surgical approach followed by postoperative radiotherapy for the undifferentiated tumours and extensive ones. For the limited and better differentiated, a more limited excision, such as total parotidectomy preserving the facial nerve is suggested.

AIDS-related lymphoma of the oral cavity

Six new cases of non-Hodgkin's lymphoma (NHL), primarily located in the oral cavity, in patients infected by the human immunodeficiency virus (HIV), are presented. They all had a voluminous fungous tumoral mass, that extended from the gingiva to the buccal vestibule or palate. All were intravenous drug abusers. The diagnosis of AIDS was known in one patient, 2 patients presented with AIDS-related complex symptomatology, and in 3 cases NHL was the first manifestation of the HIV infection. All presented advanced stages (IV). Histologically, all were considered high grade NHL. It is recommended to determine the HIV status in all young patients affected with oral NHL. All intraoral lesions in AIDS patients or in patients that belong to a risk group should have a biopsy to rule out NHL or any other manifestations of AIDS.

Maxillofacial malignant peripheral nerve sheath tumours

The clinical and pathological features of 7 patients with MPNST in the maxillofacial area are reviewed. They occurred in five men and two women; ages ranged from seven to eighty years. The parotid area and infratemporal fossa were the commonest sites (two cases each), followed by the lower lip, cheek and central mandible (one case each). Two had the antecedent of an excised neurofibroma, one with von Recklinghausen's disease and radiotherapy, that had recurred many times. Pathological slides were revised. Immunohistochemistry with S-100 protein was positive in 6 of 7 cases; electron microscopy confirmed the diagnosis in 3 cases. None showed divergent differentiation. Surgical treatment was performed in all, with or without radiotherapy. Surgical margins were positive in five cases. Recurrence took place in six and was multiple in three. Surgical salvage of the local recurrences produced satisfactory results in 3 of the 6 cases. One patient developed lung metastasis.

[Benign hemophagocytic syndrome. First confirmed case in Panama]

The authors present the clinical history of the first case of benign hemophagocytic syndrome diagnosed in Panama. The patient, a 4 year old girl, presented with fever, anemia, cervical lymphadenitis, hepatomegaly, lymphocytosis and histophagocytosis of red cells, lymphocytes, neutrophils and platelets. Spontaneous remission of the fever occurred sixty days after the onset of the disease. Although it was not possible to demonstrate serologically that the syndrome was due to acute toxoplasmosis, she was treated with sulfadiazine and pyrimethamine for fifteen days, on the 37th hospital day, and with clindamycin for ten days, consecutively. Remission occurred seventy days after the onset of fever. A second serological examination for toxoplasmosis (immunofluorescent antibodies) was positive in a titer of 1:2048 again, nine months after the first serology.

Rhinocerebral mucormycosis. Presentation of two cases and review of the literature

Mucormycosis is a serious infection with a fulminating course caused by opportunistic fungi. The territory most frequently affected is the maxillofacial region. The disease develops in patients with severe metabolic and immunological disorders. We present two cases that illustrate its severity and the need for early diagnosis and aggressive treatment.

[Predictive value of ventricular extrasystole in the exertion test and its relation to the magnitude of coronary damage]

The predictive value of ventricular arrhythmias, associated with treadmill exercise testing was evaluated in 115 patients undergoing coronary angiography and left ventriculography within three months of the exercise test. 39 patients with ventricular arrhythmias (at least one premature ventricular complex, paired complex or ventricular tachycardia) had a higher or multivessels disease than the patients without ventricular arrhythmias (P less than 0.05). This study demonstrated that ventricular arrhythmias detected at exercise testing are related to the extent of coronary artery disease, and the presence of the left ventricular disfunction.