Dearomatization drives complexity generation in freshwater organic matter

Dissolved organic matter (DOM) is one of the most complex, dynamic and abundant sources of organic carbon, but its chemical reactivity remains uncertain1-3. Greater insights into DOM structural features could facilitate understanding its synthesis, turnover and processing in the global carbon cycle4,5. Here we use complementary multiplicity-edited 13C nuclear magnetic resonance (NMR) spectra to quantify key substructures assembling the carbon skeletons of DOM from four main Amazon rivers and two mid-size Swedish boreal lakes. We find that one type of reaction mechanism, oxidative dearomatization (ODA), widely used in organic synthetic chemistry to create natural product scaffolds6-10, is probably a key driver for generating structural diversity during processing of DOM that are rich in suitable polyphenolic precursor molecules. Our data suggest a high abundance of tetrahedral quaternary carbons bound to one oxygen and three carbon atoms (OCqC3 units). These units are rare in common biomolecules but could be readily produced by ODA of lignin-derived and tannin-derived polyphenols. Tautomerization of (poly)phenols by ODA creates non-planar cyclohexadienones, which are subject to immediate and parallel cycloadditions. This combination leads to a proliferation of structural diversity of DOM compounds from early stages of DOM processing, with an increase in oxygenated aliphatic structures. Overall, we propose that ODA is a key reaction mechanism for complexity acceleration in the processing of DOM molecules, creation of new oxygenated aliphatic molecules and that it could be prevalent in nature.

Distinct Non-conservative Behavior of Dissolved Organic Matter after Mixing Solimões/Negro and Amazon/Tapajós River Waters

Positive and negative electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry and 1H NMR revealed major compositional and structural changes of dissolved organic matter (DOM) after mixing two sets of river waters in Amazon confluences: the Solimões and Negro Rivers (S + N) and the Amazon and Tapajós Rivers (A + T). We also studied the effects of water mixing ratios and incubation time on the composition and structure of DOM molecules. NMR spectra demonstrated large-scale structural transformations in the case of S + N mixing, with gain of pure and functionalized aliphatic units and loss of all other structures after 1d incubation. A + T mixing resulted in comparatively minor structural alterations, with a major gain of small aliphatic biomolecular binding motifs. Remarkably, structural alterations from mixing to 1d incubation were in essence reversed from 1d to 5d incubation for both S + N and A + T mixing experiments. Heterotrophic bacterial production (HBP) in endmembers S, N, and S + N mixtures remained near 0.03 μgC L-1 h-1, whereas HBP in A, T, and A + T were about five times higher. High rates of dark carbon fixation took place at S + N mixing in particular. In-depth biogeochemical characterization revealed major distinctions between DOM biogeochemical changes and temporal evolution at these key confluence sites within the Amazon basin.

Comprehensive assessment of dissolved organic matter processing in the Amazon River and its major tributaries revealed by positive and negative electrospray mass spectrometry and NMR spectroscopy

Rivers are natural biogeochemical systems shaping the fates of dissolved organic matter (DOM) from leaving soils to reaching the oceans. This study focuses on Amazon basin DOM processing employing negative and positive electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI[±] FT-ICR MS) and nuclear magnetic resonance spectroscopy (NMR) to reveal effects of major processes on the compositional space and structural characteristics of black, white and clear water systems. These include non-conservative mixing at the confluences of (1) Solimões and the Negro River, (2) the Amazon River and the Madeira River, and (3) in-stream processing of Amazon River DOM between the Madeira River and the Tapajós River. The Negro River (black water) supplies more highly oxygenated and high molecular weight compounds, whereas the Solimões and Madeira Rivers (white water) contribute more CHNO and CHOS molecules to the Amazon River main stem. Aliphatic CHO and abundant CHNO compounds prevail in Tapajos River DOM (clear water), likely originating from primary production. Sorption onto particles and heterotrophic microbial degradation are probably the principal mechanisms for the observed changes in DOM composition in the Amazon River and its tributaries.

[Comparative study of the treatment of subtrochanteric fractures in elderly patients: reconstruction nail T2 vs long Gamma nail]

INTRODUCTION

Subtrochanteric fractures are associated with a high rate of complications. Intramedullary nails have proven to be the best choice for treatment, but no implant has been shown to be superior to another. We want to study the differences between treating subtrochanteric fractures in the elderly with two different types of nails: T2 Recon vs Gamma3 long.

MATERIAL AND METHODS

Comparative retrospective study between 2013 and 2015 with 54 patients with subtrochanteric fractures and more than 65 years. The average follow-up is 12 months; 26 patients were treated with T2 Recon, and 28 with Gamma3. The duration of surgery, need for transfusion, evolution and complications of fractures were compared in both groups.

RESULTS

The duration of surgery was significantly longer for T2 Recon (p = 0.035), while the need for transfusion and fracture evolution were similar in both groups. Three cases required another surgery to achieve the final consolidation of the fracture. Two of them due to a failure of the T2 Recon implant, which represents 7.69% of the patients in this group, while the other case belonged to the Gamma3 group and it was sufficient to perform a nail dynamization.

CONCLUSIONS

We found no statistically significant differences, except for a longer surgical time in the T2 Recon group, being a surgeon-dependent variable that is not enough to prove that one nail is better than another.

Molecular differences between water column and sediment pore water SPE-DOM in ten Swedish boreal lakes

Boreal lakes are considered hot spots of dissolved organic matter (DOM) processing within the global carbon cycle. This study has used FT-ICR mass spectrometry and comprehensive data evaluation to assess the molecular differences of SPE-DOM between lake column water SPE-DOM and sedimentary pore water SPE-DOM in 10 Swedish boreal lakes of the Malingsbo area, which were selected for their large diversity of physicochemical and morphological characteristics. While lake column water is well mixed and fairly oxygenated, sedimentary pore water is subject to depletion of oxygen and to confinement of molecules. Robust trends were deduced from molecular compositions present in all compartments and in all 10 lakes ("common compositions") with recognition of relative abundance. Sedimentary pore water SPE-DOM featured higher proportions of heteroatoms N and S, higher average H/C ratios in presence of higher DBE/C ratios, and higher average oxygenation than lake column water SPE-DOM. These trends were observed in all lakes except Ljustjärn, which is a ground water fed kettle lake with an unique lake biogeochemistry. Analogous trends were also observed in case of single or a few lakes and operated also for compounds present solely in either lake column water or sedimentary pore water. Unique compounds detected in either compartments and/or in a few lakes showed higher molecular diversity than the "common compositions". Processing of DOM molecules in sediments included selective preservation for polyphenolic compounds and microbial resynthesis of selected molecules of considerable diversity.

Repeatedly recurring pleomorphic adenoma: a therapeutic challenge

Pleomorphic adenoma (PA) is the most common tumour of the salivary glands, and can recur even after proper surgery. The extent and timing of surgery for recurrent tumours remains controversial, and multiple recurrences pose a special challenge. We evaluated all recurrent PAs (RPAs) treated at the Helsinki University Hospital through 2004-2013 focusing on patients with multiple recurrences. Follow-up data were obtained until January 2018. Of the 47 patients, 70% were women and the median age was 33.5 years. Most of the RPAs were located in the parotid gland (87%), and six (13%) in the submandibular gland. One-third (17/47) of tumours had been primarily excised. This patient population experienced 75 recurrent events in total with two or more recurrences in 14 patients (30%). The time interval between recurrences shortened after each recurrent event and the tumour was more likely to be multifocal. At the end of the follow-up period, 15% had recurrent disease and malignant transformation had occurred in 6%. Treatment for PA and RPA is challenging and requires centralised management. Patients with RPA are often young and recurrences may cause lifelong morbidity, especially when the tumour recurs repeatedly. The utilisation and timing of postoperative radiotherapy needs to be discussed as well as the potential risk for malignant transformation in this patient population.

Extensive processing of sediment pore water dissolved organic matter during anoxic incubation as observed by high-field mass spectrometry (FTICR-MS)

Dissolved organic matter (DOM) contained in lake sediments is a carbon source for many microbial degradation processes, including aerobic and anaerobic mineralization. During anaerobic degradation, DOM is partially consumed and transformed into new molecules while the greenhouse gases methane (CH₄) and carbon dioxide (CO₂) are produced. In this study, we used ultrahigh resolution mass spectrometry to trace differences in the composition of solid-phase extractable (PPL resin) pore water DOM (SPE-DOM) isolated from surface sediments of three boreal lakes before and after 40 days of anoxic incubation, with concomitant determination of CH₄ and CO₂ evolution. CH₄ and CO₂ production detected by gas chromatography varied considerably among replicates and accounted for fractions of ∼2-4 × 10^-4 of sedimentary organic carbon for CO₂ and ∼0.8-2.4 × 10^-5 for CH₄. In contrast, the relative changes of key bulk parameters during incubation, such as relative proportions of molecular series, elemental ratios, average mass and unsaturation, were regularly in the percent range (1-3% for compounds decreasing and 4-10% for compounds increasing), i.e. several orders of magnitude higher than mineralization alone. Computation of the average carbon oxidation state in CHO molecules of lake pore water DOM revealed rather non-selective large scale transformations of organic matter during incubation, with depletion of highly oxidized and highly reduced CHO molecules, and formation of rather non-labile fulvic acid type molecules. In general, proportions of CHO compounds slightly decreased. Nearly saturated CHO and CHOS lipid-like substances declined during incubation: these rather commonplace molecules were less specific indicators of lake sediment alteration than the particular compounds, such as certain oxygenated aromatics and carboxyl-rich alicyclic acids (CRAM) found more abundant after incubation. There was a remarkable general increase in many CHNO compounds during incubation across all lakes. Differences in DOM transformation between lakes corresponded with lake size and water residence time. While in the small lake Svarttjärn, CRAM increased during incubation, lignin-and tannin-like compounds were enriched in the large lake Bisen, suggesting selective preservation of these rather non-labile aromatic compounds rather than recent synthesis. SPE-DOM after incubation may represent freshly synthesized compounds, leftover bulk DOM which is primarily composed of intrinsically refractory molecules and/or microbial metabolites which were not consumed in our experiments. In spite of a low fraction of the total DOM being mineralized to CO₂ and CH₄, the more pronounced change in molecular DOM composition during the incubation indicates that diagenetic modification of organic matter can be substantial compared to complete mineralization.

[Dislocation of the proximal hallux interphalangeal joint with interposition of a sesamoid bone: a blibliographic review]

The irreducible dislocation of the hallux interphalangeal joint is an infrequent condition and only a few cases have been described. It presents as dorsal dislocation with interposition of the sesamoid bone, which has the possibility of being radiologically undetectable. We present the case of a 29 year-old patient who, after a sports trauma sustained a hallux interphalangeal dislocation that went unnoticed for eight days. Since, closed reduction was not possible, as occurred in several cases reported in the literature, open reduction was performed through a dorsal incision. Based on a bibliographic review, it is possible to state that there are several treatment options and multiple approaches, and that these lesions usually have a good prognosis.

Guidelines for the management of gastroenteropancreatic neuroendocrine (including carcinoid) tumours (NETs)

These guidelines update previous guidance published in 2005. They have been revised by a group who are members of the UK and Ireland Neuroendocrine Tumour Society with endorsement from the clinical committees of the British Society of Gastroenterology, the Society for Endocrinology, the Association of Surgeons of Great Britain and Ireland (and its Surgical Specialty Associations), the British Society of Gastrointestinal and Abdominal Radiology and others. The authorship represents leaders of the various groups in the UK and Ireland Neuroendocrine Tumour Society, but a large amount of work has been carried out by other specialists, many of whom attended a guidelines conference in May 2009. We have attempted to represent this work in the acknowledgements section. Over the past few years, there have been advances in the management of neuroendocrine tumours, which have included clearer characterisation, more specific and therapeutically relevant diagnosis, and improved treatments. However, there remain few randomised trials in the field and the disease is uncommon, hence all evidence must be considered weak in comparison with other more common cancers.

A multicentre study of capecitabine, oxaliplatin plus bevacizumab as perioperative treatment of patients with poor-risk colorectal liver-only metastases not selected for upfront resection

BACKGROUND

Perioperative chemotherapy improves outcome in resectable colorectal liver-only metastasis (CLM). This study aimed to evaluate perioperative CAPOX (capecitabine-oxaliplatin) plus bevacizumab in patients with poor-risk CLM not selected for upfront resection.

PATIENTS AND METHODS

Poor-risk CLM was defined as follows: more than four metastases, diameter >5 cm, R0 resection unlikely, inadequate viable liver function if undergoing upfront resection, inability to retain liver vascular supply, or synchronous colorectal primary presentation. Patients underwent baseline computed tomography, magnetic resonance imaging, and/or positron emission tomography (PET) for staging and received neoadjuvant CAPOX plus bevacizumab, with resectability assessed every four cycles. Primary end point was radiological objective response rate (ORR).

RESULTS

Forty-six patients were recruited, of which 91% underwent PET to ensure metastases confined to liver. Following neoadjuvant CAPOX plus bevacizumab, the ORR was 78% (95% confidence interval 63% to 89%). This allowed 12 of 30 (40%) patients with initial nonsynchronous unresectable CLM to be converted to resectability. In addition, 10 of 15 (67%) patients with synchronous resectable CLM underwent liver resection, with four additional patients being observed alone due to excellent response to neoadjuvant therapy. No grade 3-4 perioperative complications were seen.

CONCLUSION

Neoadjuvant CAPOX plus bevacizumab resulted in a high response rate for patients with CLMs with poor-risk features not selected for upfront resection and converted 40% of patients to resectability.

Efficacy and tolerability of limited field radiotherapy with concurrent capecitabine in locally advanced pancreatic cancer

AIMS

Patients with locally advanced pancreatic cancer (LAPC) are most commonly managed with chemotherapy or concurrent chemoradiotherapy (CRT), which may or may not include non-involved regional lymph nodes in the clinical target volume. We present our results of CRT for LAPC using capecitabine and delivering radiotherapy to a limited radiation field that excluded non-involved regional lymph nodes from the clinical target volume.

MATERIALS AND METHODS

Thirty patients were studied. Patients received 50.4 Gy external beam radiotherapy in 28 fractions, delivered to a planning target volume expanded from the primary tumour and involved nodes only. Capecitabine (500-600 mg/m2) was given twice daily continuously during radiotherapy. Toxicity and efficacy data were prospectively collected.

RESULTS

Nausea, vomiting and tumour pain were the most common grade 2 toxicities. One patient developed grade 3 nausea. The median time to progression was 8.8 months, with 20% remaining progression free at 1 year. The median overall survival was 9.7 months with a 1 year survival of 30%. Of 21 patients with imaged progression, 13 (62%) progressed systemically, three (14%) had local progression, two (10%) had locoregional progression and three (14%) progressed with both local/locoregional and systemic disease.

CONCLUSION

CRT using capecitabine and limited field radiotherapy is a well-tolerated, relatively efficacious treatment for LAPC. The low toxicity and low regional progression rates support the use of limited field radiotherapy, allowing evaluation of this regimen with other anti-cancer agents.

A PET imaging study of the vascular disruptive agent OXi4503 to confirm in vivo mechanism of action in a phase I trial

e14510

Background: OXi4500, the active product of OXi4503, reversibly binds at the colchicine binding site on the ß subunit of tubulin. This study investigated its mechanism of action using PET molecular imaging Methods: OXi4503 was administered by 3 weekly IV infusions in a phase 1 trial (32 pts). Between 1.6 & 15.4 mg/m2 dose levels, PET imaging was performed with 15O-labelled water (measuring blood perfusion) pretreatment & at 90min & 24hr after first infusion (8pts) & at 28days (1 pt). [18F]fluorodeoxyglucose (FDG) (measuring proliferative activity) was performed pretreatment & at 28 days (9pts) Results: 9 pts (mean age 48.5yrs) were studied: CRC (2), pancreatic (1), MM (6). 2 pts with MM (3.8 & 6.5 mg/m2) achieved stable disease. Toxicity included pyrexia, lethargy & hypertension. There was a dose-dependent linear increase in peak plasma concentrations & AUC of OXi4503 & OXi4500. Sustained tumour blood perfusion reduction (50% at 90min & 24hr) was seen in all metastases in the CRC pt treated at 15.4 mg/m2 after just one dose & resulted in FDG reduction (23% in all 5 mets) & tumor marker response. Doses between 1.9 & 11.0 mg/m2 produced dose independent reductions in tumour perfusion which were more variable & less marked with 3/8 pts showing a reduction in tumour FDG uptake. The 1pt studied at 28 days (8.5 g/m2) showed further sustained reduction in tumour blood flow (40%). Variable dose independent changes in normal tissue perfusion were seen at all dose levels eg in 3/4 pt splenic perfusion showed a dose-independent decrease (20–30%) at 90min with recovery at 24hr Conclusions: OXi4503 shows significant activity at 15.4 mg/m2 in line with its proposed mechanism of action. Characterisation of the mixed tumour perfusion response at lower doses will aid planning & assessing combination studies. The MTD is now being identified. Sponsored by CRUK.

[Table: see text]

An ecological risk assessment of the acute and chronic toxicity of the herbicide picloram to the threatened bull trout (Salvelinus confluentus) and the rainbow trout (Onchorhyncus mykiss)

We conducted acute and chronic toxicity studies of the effects of picloram acid on the threatened bull trout (Salvelinus confluentus) and the standard coldwater surrogate rainbow trout (Oncorhynchus mykiss). Juvenile fish were chronically exposed for 30 days in a proportional flow-through diluter to measured concentrations of 0, 0.30, 0.60, 1.18, 2.37, and 4.75 mg/L picloram. No mortality of either species was observed at the highest concentration. Bull trout were twofold more sensitive to picloram (30-day maximum acceptable toxic concentration of 0.80 mg/L) compared to rainbow trout (30-day maximum acceptable toxic concentration of 1.67 mg/L) based on the endpoint of growth. Picloram was acutely toxic to rainbow trout at 36 mg/L (96-h ALC50). The acute:chronic ratio for rainbow trout exposed to picloram was 22. The chronic toxicity of picloram was compared to modeled and measured environmental exposure concentrations (EECs) using a four-tiered system. The Tier 1, worst-case exposure estimate, based on a direct application of the current maximum use rate (1.1 kg/ha picloram) to a standardized aquatic ecosystem (water body of 1-ha area and 1-m depth), resulted in an EEC of 0.73 mg/L picloram and chronic risk quotients of 0.91 and 0.44 for bull trout and rainbow trout, respectively. Higher-tiered exposure estimates reduced chronic risk quotients 10-fold. Results of this study indicate that picloram, if properly applied according to the manufacturer's label, poses little risk to the threatened bull trout or rainbow trout in northwestern rangeland environments on either an acute or a chronic basis.

Protection from Staphylococcus aureus mastitis associated with poly-N-acetyl beta-1,6 glucosamine specific antibody production using biofilm-embedded bacteria

Staphylococcus aureus vaccines based on bacterins surrounded by slime, surface polysaccharides coupled to protein carriers and polysaccharides embedded in liposomes administered together with non-biofilm bacterins confer protection against mastitis. However, it remains unknown whether protective antibodies are directed to slime-associated known exopolysaccharides and could be produced in the absence of bacterin immunizations. Here, a sheep mastitis vaccination study was carried out using bacterins, crude bacterial extracts or a purified exopolysaccharide from biofilm bacteria delivered in different vehicles. This polysaccharide reacted specifically with antibodies to poly-N-acetyl-beta-1,6-glucosamine (PNAG) and not with antibodies to other capsular antigens or bacterial components. Following intra-mammary challenge with biofilm-producing bacteria, antibody production against the polysaccharide, milk bacterial counts and mastitis lesions were determined. Bacterins from strong biofilm-producing bacteria triggered the highest production of antibodies to PNAG and conferred the highest protection against infection and mastitis, compared with weak biofilm-producing bacteria and non-cellular inocula. Thus, bacterins from strong biofilm bacteria, rather than purified polysaccharide, are proposed as a cost-efficient vaccination against S. aureus ruminant mastitis.

[Profile of bipolar disorder outpatients: a cross-sectional study in the Madrid Community]

INTRODUCTION

The purpose of this cross-sectional study is to obtain a sociodemographic, clinical, psychosocial functioning and therapeutic profile of bipolar outpatients in the Madrid Community.

METHODS

A total of 115 outpatients were consecutively recruited by 10 psychiatrists.

RESULTS

Mean time between initial symptoms and an accurate bipolar diagnosis was of 7.6 years. A depressive episode was the onset of the illness in most patients independently of clinical subtype. Syndromal or subsyndromal symptoms were present in 47% of the patient population, dominating the depressive polarity (33.1%). A subjectively reduced perception of quality of life was associated to the presence of depressive symptoms and a worse clinical outcome last year. More than half of the patients (58.2%) were overweight or obese. Lithium was the most frequently used mood stabilizer (71.3%), whereas 41% of the patients were taking at least three psychotropic drugs.

CONCLUSIONS

Results of this study widely confirm previous data on bipolar disorder. Reduction in quality of life of bipolar patients associated to depressive symptoms must be highlighted. It is necessary to optimize treatments in bipolar disorder in order to improve prognosis.

Cross validation with the mood disorder questionnaire (MDQ) of an instrument for the detection of hypomania in Spanish: the 32 item hypomania symptom check list (HCL-32)

BACKGROUND

The detection and diagnosis of present or past hypomanic episodes is of key importance for the differential diagnosis between depressive disorders and type II bipolar disorder. However, there are few instruments available to satisfactorily screen for the latter condition. The Hypomania Symptom Checklist-32 (HCL-32) is a self-applied questionnaire with 32 hypomania items and 8 severity and functional impact items which is being developed in several European countries for this purpose. Our aim was to develop and validate the psychometric properties of the HCL-32 scale in Spain in patients with bipolar disorder and to compare its properties with other instruments available for the detection of bipolar II disorder.

METHODS

Patients were selected from 15 psychiatric outpatient departments, diagnosed with type I or type II bipolar disorder (BDI and BDII) and unipolar major depression (MD) according to DSM-IV-TR criteria. A control group of healthy subjects (HS) was likewise assessed. The patient selection criteria included a well-established diagnosis and a stable disorder and pharmacological treatment. The HCL-32 was administered to 237 subjects distributed among the above groups, on two occasions four weeks apart. We analysed the internal consistency, test-retest reliability and discriminative capacity of the HCL-32.

RESULTS

The internal consistency of the Spanish version of the HCL-32, evaluated by Cronbach's alpha, was 0.94. Mean of affirmative questions by group were 21.2 (SD 5.8) for BDI, 19.3 (SD 6.2) for BDII, 8.6 (SD 6.6) for MD and 6.6 (SD 6.1) for HS, with statistically significant differences between them (Kruskal-Wallis test, p<0.001). Concurrent validity using the diagnosis variable was 0.72. Test-retest reliability was 0.90. We analysed the best cut-off point by means of a ROC curve analysis; for 14 affirmative responses, a sensitivity of 0.85 95%CI (0.78, 0.91) and specificity of 0.79, 95%CI (0.72, 0.87) were obtained. The positive and negative probability ratios were 4.1 and 5.3 (1/0.19 respectively). HCL-32 shows a dual factor structure of items, one as an energy-activity factor and another one as a factor involving items related to disinhibition and problems with self-control and attention.

LIMITATIONS

The sample size of bipolar patients (particularly type BDII) should be increased in further studies.

CONCLUSIONS

The Spanish version of the HCL-32 has good psychometric properties and sufficient sensitivity and specificity, detecting 8 out of every 10 patients with BD. The HCL-32 is a useful screening tool of patients with bipolar disorder in clinical settings. In its present form it adequately discriminates between bipolar and unipolar or healthy subjects, but not between BD I and BII.

Spinosad, a naturally derived insecticide, for control of Aedes aegypti (Diptera: Culicidae): efficacy, persistence, and elicited oviposition response

The naturally derived insecticide spinosad is a reduced-risk material that is neurotoxic to Diptera. The 24-h 50% lethal concentration by laboratory bioassay in third instars of Aedes aegypti (L.) (Diptera: Culicidae) (Rockefeller strain) was estimated at 0.026 ppm. Two identical field trials were performed in an urban cemetery in southern Mexico during the dry and wet seasons. Water containers treated with 1 or 5 ppm spinosad suspension concentrate (Tracer, Dow Agrosciences) were as effective in preventing the development of Aedes spp. (mostly Ae. aegypti) as temephos granules during both trials, whereas the bacterial insecticide VectoBac 12AS performed poorly. The half-life of aqueous solutions of spinosad (10 ppm) placed in a warm sunny location was 2.1 d, compared with 24.5 d for solutions in a shaded location. Spinosad, temephos, and VectoBac were not repellent to gravid Ae. aegypti at the concentrations tested, and no ovicidal properties were observed. The 24-h survival of neonate larvae but was reduced by 94-100% in the presence of residues carried over from the spinosad treatments, but it was not affected by residues of temephos or VectoBac. The toxicological properties of spinosad, combined with its favorable environmental profile, should encourage the detailed evaluation of spinosad as a mosquito larvicide in domestic and urban environments.

Impact of environmental manipulation for Anopheles pseudopunctipennis Theobald control on aquatic insect communities in southern Mexico

Extraction of filamentous algae from river pools is highly effective for the control of Anophelespseudopunctipennis in southern Mexico. We determined the magnitude of changes to the aquatic insect community following single annual perturbations performed over two years. In 2001, algae were manually removed from all the pools in a 3 km long section of the River Coatán, Mexico, while an adjacent section was left as an untreated control. In 2002, the treatments of both zones were switched and algal extraction was repeated. The abundance of An. pseudopunctipennis larvae + pupae was dramatically reduced by this treatment and remained depressed for two to three months. A total of 11,922 aquatic insects from ten orders, 40 families, and 95 genera were collected in monthly samples taken over five months of each year. Algal extraction did not reduce the overall abundance of aquatic insects in river pools, but a greater abundance and a greater richness of taxa were observed in 2002 compared to the previous year. This was associated with reduced precipitation and river discharge in 2002 compared to 2001. Shannon diversity index values were significantly depressed following algal extraction for a period of three months, in both years, before returning to values similar to those of the control zone. However, differences between years were greater than differences between treatments within a particular year. When insects were classified by functional feeding group (FFG), no significant differences were detected in FFG densities between extraction and control zones over time in either year of the study. Similarly, percent model affinity index values were classified as "not impacted" by the extraction process. Discriminant function analysis identified two orders of insects (Diptera and Odonata), water temperature, dissolved oxygen and conductivity, and river volume (depth, width, and discharge) as being of significant value in defining control and treatment groups in both years. We conclude that habitat manipulation represents an effective and environmentally benign strategy for control of An. pseduopunctipennis. Variation in precipitation and river discharge between years was much more important in determining aquatic insect community composition than variation generated by the filamentous algal extraction treatment.

[Applicability of the ICF in measuring functioning and disability in unipolar depression in Primary Care settings]

INTRODUCTION

We use the biopsychosocial model of the International Classification of Functioning, Disability, and Health (ICF): a) to analyze functioning and disability patterns in unipolar depression cases attended in primary care settings; b) to study predictive and mediator variables related to disability in depression, and c) to determine the impact of traditional interventions in depression cases using functional remission as outcome measure.

DESIGN

Naturalistic, prospective, longitudinal.

SETTING

Multicenter study in primary care. Health Area 2. Region of Madrid.

PARTICIPANTS

Adult patients with a diagnosis of unipolar depression who initiate psychopharmacological treatment with selective serotonin reuptake inhibitor (SSRI) in primary care sites. Patients with history of bipolar disorders, psychotic disorders, dementias, and dependence of toxic substances will be excluded.

MAIN MEASUREMENTS

Level of functioning and disability in different domains of well-being assessed through ICF related instruments. Stressful life events, social support and cognitive schemes will be analyzed as mediator variables. Socio-demographic and clinical characteristics, psychopharmacological treatment and treatment compliance are considered independent factors. DISCUSSION AND PRACTICAL USE: Selection bias may affect the generalization of the results. The biopsychosocial model underlying the ICF and its methodology are applied to the study of depression in primary care settings for the first time in Spain. Improving our understanding of disability related factors in depressive patients is expected. This study is one of the main research priorities of the EU (MHADIE project).

Persistence of invertebrate iridescent virus 6 in tropical artificial aquatic environments. Brief report

The rate of loss of activity of invertebrate iridescent virus 6 (IIV-6, family Iridoviridae) was determined in two artificial aquatic habitats in southern Mexico, using a sensitive insect bioassay technique. IIV-6 placed in trays of water in direct sunlight suffered rapid loss of activity (99.99% reduction) over a period of 36 h, during which water temperatures fluctuated between 24 and 41 degrees C. No significant deactivation occurred during the hours of darkness. In contrast, IIV-6 placed in trays of water in the shade lost 97% of original activity over a 60 h period, during which water temperatures fluctuated from 24 to 31 degrees C. Longitudinal analysis involving mixed effects models of time (shade) and cumulative exposure to ultraviolet radiation (sunlight) indicated that the rate of deactivation was best described by third order polynomial equations in both cases. We conclude that the likelihood of transmission of IIVs in aquatic habitats will be mediated by the intensity of UV radiation and water temperature.