Non-random interactions within and across guilds shape the potential to coexist in multi-trophic ecological communities

Theory posits that the persistence of species in ecological communities is shaped by their interactions within and across trophic guilds. However, we lack empirical evaluations of how the structure, strength and sign of biotic interactions drive the potential to coexist in diverse multi-trophic communities. Here, we model community feasibility domains, a theoretically informed measure of multi-species coexistence probability, from grassland communities comprising more than 45 species on average from three trophic guilds (plants, pollinators and herbivores). Contrary to our hypothesis, increasing community complexity, measured either as the number of guilds or community richness, did not decrease community feasibility. Rather, we observed that high degrees of species self-regulation and niche partitioning allow for maintaining larger levels of community feasibility and higher species persistence in more diverse communities. Our results show that biotic interactions within and across guilds are not random in nature and both structures significantly contribute to maintaining multi-trophic diversity.

A genome-wide association study identifies novel gene associations with facial skin wrinkling and mole count in Latin Americans

BACKGROUND

Genome-wide association studies (GWASs) have identified genes influencing skin ageing and mole count in Europeans, but little is known about the relevance of these (or other genes) in non-Europeans.

OBJECTIVES

To conduct a GWAS for facial skin ageing and mole count in adults < 40 years old, of mixed European, Native American and African ancestry, recruited in Latin America.

METHODS

Skin ageing and mole count scores were obtained from facial photographs of over 6000 individuals. After quality control checks, three wrinkling traits and mole count were retained for genetic analyses. DNA samples were genotyped with Illumina's HumanOmniExpress chip. Association testing was performed on around 8 703 729 single-nucleotide polymorphisms (SNPs) across the autosomal genome.

RESULTS

Genome-wide significant association was observed at four genome regions: two were associated with wrinkling (in 1p13·3 and 21q21·2), one with mole count (in 1q32·3) and one with both wrinkling and mole count (in 5p13·2). Associated SNPs in 5p13·2 and in 1p13·3 are intronic within SLC45A2 and VAV3, respectively, while SNPs in 1q32·3 are near the SLC30A1 gene, and those in 21q21·2 occur in a gene desert. Analyses of SNPs in IRF4 and MC1R are consistent with a role of these genes in skin ageing.

CONCLUSIONS

We replicate the association of wrinkling with variants in SLC45A2, IRF4 and MC1R reported in Europeans. We identify VAV3 and SLC30A1 as two novel candidate genes impacting on wrinkling and mole count, respectively. We provide the first evidence that SLC45A2 influences mole count, in addition to variants in this gene affecting melanoma risk in Europeans.

DG Connect Funded Projects on Information and Communication Technologies (ICT) for Old Age People: Beyond Silos, CareWell and SmartCare

Information and communication technologies (ICT) are promising for the long-term care of older and frequently frail people. These innovations can improve health outcomes, quality of life and efficiency of care processes, while supporting independent living. However, they may be disruptive innovations. As all European member states are facing an increasing complexity of health and social care, good practices in ICT should be identified and evaluated. Three projects funded by DG CNECT are related to Active and Healthy Ageing (AHA) and frailty: (i) BeyondSilos, dealing with independent living and integrated services, (ii) CareWell, providing integrated care coordination, patient empowerment and home support and (iii) SmartCare, proposing a common set of standard functional specifications for an ICT platform enabling the delivery of integrated care to older patients. The three projects described in this paper provide a unique pan-European research field to further study implementation efforts and outcomes of new technologies. Below, based on a description of the projects, the authors display four domains that are in their views fundamental for in-depth exploration of heterogeneity in the European context: 1. Definition of easily transferable, high level pathways with solid evidence-base; 2. Change management in implementing ICT enabled integrated care; 3. Evaluation and data collection methodologies based on existing experience with MAST and MEDAL methodologies; and 4. Construction of new models for delivery of health and social care. Understanding complementarity, synergies and differences between the three unique projects can help to identify a more effective roll out of best practices within a varying European context.

Unresponsiveness to a kidney graft after a fully matched allogenic bone marrow transplantation combined with low-dose tacrolimus therapy: a case report

We present the case of a patient with past medical history of acute mieloblastic leukemia treated with a related, fully match alogenic bone marrow transplantation (BMT). He presented after BMT treatment graft versus host disease (GVHD) and thrombotic thrombocytopenic purpura. He also developed end-stage renal disease that required renal replacement therapy. A preemptive kidney transplant was performed. The haematopoiesis were in complete chimera and the patient developed tolerance to the kidney graft, requiring only minimal immunossupression because of his GVHD.

Comparison of three microtube column agglutination systems for antibody screening: DG Gel, DiaMed-ID and Ortho BioVue

The aims of the present study were to evaluate the estimated diagnostic accuracy of a new microtube column agglutination system (DG Gel, Diagnostic Grifols, Barcelona, Spain), to analyse the antibody reactivity and to compare the data with the two well-established DiaMed-ID and Ortho BioVue systems. We collected 3024 consecutive samples from blood donors, transfusion recipients and pregnant women, and 100 samples containing antibodies of known specificity. All these samples were tested in parallel by the three microtube agglutination systems. The estimated sensitivity was 100% for DG Gel and Ortho BioVue and 97.58% for DiaMed-ID. The estimated specificity was 99.93% for Ortho BioVue and 100% for DiaMed-ID and DG Gel. The score mean and range of the antibody titration of DG Gel, DiaMed-ID and Ortho BioVue were 34.31 (5-119), 30.3 (3-121) and 37.38 (3-112), respectively. All three column agglutination systems work well showing a high estimated diagnostic accuracy.

[Contrast sensitivity to intraocular lens TECNIS Z-9000]

PURPOSE

To evaluate the increase in contrast sensitivity to intraocular lens TECNIS Z-9000 (Pfizer) compared with other intraocular lenses.

METHOD

We implanted a TECNIS Z-9000 lens in 18 patients who had another type of intraocular lens implanted in their other eye. We then tested contrast sensitivity under both mesopic and photopic conditions using the VCTS (Vision Contrast Test System) provided by Vistech Consultants Inc.

RESULTS

There was an improved contrast sensitivity at low and medium frequencies, following TECNIS-Z 9000 lens implantation, however this improvement did not reach statistical significance. There were significant differences at high frequencies, which are directly related to the quality of visual function.

CONCLUSIONS

TECNIS Z-9000 lens implantation (with a modified anterior surface) achieves a significant improvement in contrast sensitivity, meaning in practice an increase in the quality of visual function.

Specific interaction of tissue-type plasminogen activator (t-PA) with annexin II on the membrane of pancreatic cancer cells activates plasminogen and promotes invasion in vitro

BACKGROUND

Overexpression of tissue plasminogen activator (t-PA) in pancreatic cancer cells promotes invasion and proliferation in vitro and tumour growth and angiogenesis in vivo.

AIMS

To understand the mechanisms by which t-PA favours cancer progression, we analysed the surface membrane proteins responsible for binding specifically t-PA and studied the contribution of this interaction to the t-PA promoted invasion of pancreatic cancer cells.

METHODS

The ability of t-PA to activate plasmin and a fluorogenic plasmin substrate was used to analyse the nature of the binding of active t-PA to cell surfaces. Specific binding was determined in two pancreatic cancer cell lines (SK-PC-1 and PANC-1), and complex formation analysed by co-immunoprecipitation experiments and co-immunolocalisation in tumours. The functional role of the interaction was studied in Matrigel invasion assays.

RESULTS

t-PA bound to PANC-1 and SK-PC-1 cells in a specific and saturable manner while maintaining its activity. This binding was competitively inhibited by specific peptides interfering with the interaction of t-PA with annexin II. The t-PA/annexin II interaction on pancreatic cancer cells was also supported by co-immunoprecipitation assays using anti-t-PA antibodies and, reciprocally, with antiannexin II antibodies. In addition, confocal microscopy showed t-PA and annexin II colocalisation in tumour tissues. Finally, disruption of the t-PA/annexin II interaction by a specific hexapeptide significantly decreased the invasive capacity of SK-PC-1 cells in vitro.

CONCLUSION

t-PA specifically binds to annexin II on the extracellular membrane of pancreatic cancer cells where it activates local plasmin production and tumour cell invasion. These findings may be clinically relevant for future therapeutic strategies based on specific drugs that counteract the activity of t-PA or its receptor annexin II, or their interaction at the surface level.

Relación entre Factores Individuales y Familiares de Riesgo para Desórdenes Alimenticios en Alumnos de Enseñanza Media

La presente investigación explora la relación entre los distintos factores de riesgode la anorexia nerviosa. Específicamente, considera edad, peso, altura, autoestima,depresión, cohesión familiar, conflicto familiar, adaptabilidad familiar. El análisisbivariado arroja las correlaciones más significativas entre autoestima y depresión(–0.728), Depresión y Anorexia (0.710), Autoestima y Anorexia (–0.699). Tambiénaparecen como significativas las correlaciones entre Anorexia Nerviosa y conflicto(0.406), cohesión (-0.289) y peso (0.285). En el análisis multivariado, la predicción de riesgo está determinada por Depresión, Autoestima, Peso, Conflicto, Cohesión, Altura y el tipo de establecimiento. Además, se discuten resultados y posibles líneas de investigación a partir de los hallazgos.

Flow cytometric assessment of allopurinol susceptibility in Leishmania infantum promastigote

BACKGROUND

Leishmaniasis is a major tropical and subtropical parasitic disease. Sodium stibogluconate, N-methyl -D-glucamine antimoniate, amphotericin B, pentamidine, and ketoconazole are drugs used to treat this disease. Some of these drugs cause severe adverse side effects and treatment failures are common. Allopurinol, a purine analog, has been used to treat leishmaniasis, alone or combined with the previously mentioned drugs. Low cost, ease of administration (oral), and lack of toxicity make allopurinol a particularly appealing candidate.

METHODS

The effect of allopurinol on Leishmania infantum (MCAN/ES/89/IPZ229/1/89, zymodeme MON1) wild-type promastigotes (wt-p229), and an altered form of these promastigotes (allo-p229) resulting from long term in vitro exposure to allopurinol, was determined by [(3)H]-thymidine incorporation assays and by diverse flow cytometric approaches.

RESULTS

Allopurinol arrested the proliferative capacity of wt-p229 promastigotes, reduced the proportion of viable cells, and decreased their total protein content. In contrast, allo-p229 promastigote proliferation was only slightly decelerated and the proportion of viable cells and the protein content were not affected by the allopurinol treatment.

CONCLUSIONS

The flow cytometry approach allowed us to demonstrate differences in allopurinol susceptibility of the two promastigote forms, expanding the spectrum of flow cytometry applications in studies of parasite resistance.

Bioequivalence study of paracetamol tablets: in vitro-in vivo correlation

The bioequivalence of three chemically equivalent paracetamol generic Mexican products (500 mg tablets) was evaluated in 12 healthy volunteers using the American innovator product (Tylenol, McNeil, Fort Washington, PA), as the reference. Single oral doses of each product were administered at 1-week intervals using a 4 x 4 Latin square design balanced for the first residual effect. The total amount of paracetamol excreted in urine in 24 hr was taken as a measure of bioavailability. In addition, moment analysis was used to estimate in vitro mean dissolution time (MDT) from dissolution profiles obtained following the USP 23 dissolution test specified for paracetamol tablets and to estimate in vivo mean residence time (MRT) from urinary excretion data. Significant differences in the dissolution performance and in the cumulative amount of paracetamol excreted in urine up to 24 hr were observed when the data were analyzed by analysis of variance (ANOVA) (p < .05). Classical and Westlake 90% confidence limits, as well as the two-sided t test proposed by Schuirmann, and the Anderson-Hauck power analysis supported the final conclusion that only one of the three generic paracetamol products studied can be considered equivalent to the reference product Tylenol. A linear correlation between in vitro MDT and in vivo MRT was found.

Detection of groundwater conduits in limestones with gravity surveys: data from the area of the Chicxulub Impact crater, Yucatan Peninsula, Mexico

Small negative gravity anomalies are found in gravity data from along the northwestern shoreline of the Yucatan Peninsula. These anomalies are shown to be due to elongate, shallow anomalous porosity zones in the Tertiary carbonates. These zones are caused primarily by groundwater solution and are presently active conduits for groundwater flow. The association of these small gravity anomalies with known topographic and structural features of the area, which partially overlies the Chicxulub Impact crater, indicates their development was influenced by structures, faults and/or fractures, within the Tertiary and pre-Tertiary carbonates.

Panorama of acute diarrhoeal diseases in Mexico

We examined the recent panorama of ADD related deaths in Mexico in an effort to assess the overall impact of control measures that may vary in space and time. We pay particular attention to mortality rates recorded between 1985-1995, that is, before and after the cholera emergency. The aim is to focus on the social groups at risk, using time series data represented in the form of images and produced by a geographic information system (GIS). We show the potential of such methods to define populations at risk and support the decision process.

Minimum inhibitory concentrations for selected antimicrobial agents against Fusobacterium necrophorum isolated from hepatic abscesses in cattle and sheep

Minimum inhibitory concentrations for 35 antimicrobial agents against 100 Fusobacterium necrophorum isolates from hepatic abscesses in sheep and cattle were determined. Twelve of the thirteen beta-lactam antibiotics tested inhibited growth of 100% of strains tested. Of the remaining antimicrobial agents, extensive susceptibility was found for: spiramycin, josamycin, lincomycin, tylosin, oxytetracycline, chlortetracycline, rufloxacin, metronidazole, cotrimoxazole, sulfadimethoxine, virginiamycin and fosfomycin.

Clinical pharmacokinetics of albendazole in patients with brain cysticercosis

Albendazole pharmacokinetics were studied in eight patients who were receiving albendazole in doses of 15 mg/kg per day for 8 days as treatment of brain cysticercosis. Albendazole was not detected in plasma, but its main metabolite albendazole sulphoxide could be measured. Maximum plasma levels for albendazole sulphoxide ranged from 0.45 to 2.96 micrograms/mL. The half-life of albendazole sulphoxide was between 10 and 15 hours. A double peak was found in three patients. Mean residence time values were from 14 to 20 hours. Plasma levels of albendazole sulphoxide at the steady state showed great intraindividual variability. The results suggest that albendazole can be administered twice daily rather than three times as is currently done.

Plasma and CSF levels of albendazole and praziquantel in patients with neurocysticercosis

Albendazole or praziquantel were measured in plasma and cerebrospinal fluid (CSF) in 29 patients with neurocysticercosis. Mean levels of albendazole in plasma were 0.918 microgram/ml and in CSF were 0.392 microgram/ml and levels of praziquantel were 1.640 micrograms/ml in plasma and 0.398 microgram/ml in CSF, after doses of 15 and 50 mg/kg, respectively. Drug concentrations in CSF were 43% for albendazole and 24% for praziquantel. The drug levels obtained for both drugs showed ample individual variations that were not related to age, sex, presence of inflammation in the subarachnoid space, or therapeutic effectiveness; such variations seem to be due to individual differences in pharmacokinetics. Both drugs were effective and the doses currently used of each drug seem to be optimal for therapy of neurocysticercosis.

Dexamethasone increases plasma levels of albendazole

Therapy of neurocysticercosis with cysticidal drugs is frequently complicated by the exacerbation of symptoms that follows the inflammation triggered by the acute destruction of cysticerci. Treatment of such adverse reactions with dexamethasone is highly effective. However, it has been shown that dexamethasone lowers the plasma levels of praziquantel, thus reducing its cysticidal efficacy. We measured plasma levels of albendazole, another strong cysticidal drug, when dexamethasone was given simultaneously. We found that dexamethasone increased the plasma levels of albendazole by about 50% (P less than 0.002); hence, it seems that cysticercosis and the ensuing inflammation can be treated simultaneously with albendazole and dexamethasone without diminishing the efficacy of the cysticidal drug.

[Removal of anaesthetic waste gases in the Kuhn system (author's transl)]

A simple device for the removal of anaesthetic gases from the Kuhn system is described. It does not interfere with the function of the system.