Making partners in the city: impact of urban soil P enrichment on the partnership between an invasive herb and arbuscular mycorrhizal fungi in a tropical city

The mutualistic relationship between plants and arbuscular mycorrhizal (AM) fungi is essential for optimal plant nutrition, enabling plants to better withstand biotic and abiotic stressors and enhancing survival, reproduction, and colonization of new environments. Activities, such as soil enrichment or compaction, may decrease the benefits of AM fungi for plants, potentially reducing interactions in urban environments. Here, we examine this prediction by studying how urbanization alters AM interactions with the invasive herb Ruellia nudiflora (Acanthaceae). We collected soil and plants from deep urban sites (DUS; e.g., sidewalks), open urban sites (OUS; parks), and rural sites (RS) to analyse soil nutrient content, plant morphology, AM colonization rates, spore density, richness, and diversity. Contrary to predicted, DUS had the lowest soil nutrient concentration, except for phosphorus, reducing AM colonization. This supports the prediction of reduced AM interactions in urban environments. We also found that potassium affects the AM association. Urban plants had smaller and more compact root systems compared to their rural counterparts, but there were no discernible differences in AM fungi communities between urban and rural environments. Phosphorus enrichment in sidewalks is the main driver of reductionof R. nudiflora-AM fungi interactions in Mérida. More studies are needed to gain a better understanding of how AM fungi contribute to plant colonization in urban environments.

Femoracetabular impingement treated with surgical hip dislocation: Short-term results

BACKGROUND AND OBJECTIVE

Most of the studies available in the literature related to the treatment of femoroacetabular impingement (FAA) with surgical hip dislocation (CLD) come from Europe and North America. This study describes the short-term results of the LQC technique for treating PFA in a cohort of Colombian patients.

PATIENTS AND METHODS

We retrospectively analysed 42 cases of PFA treated with LQC from 2006 to 2018. The same orthopaedic surgeon performed all surgeries. Clinical outcome was assessed using the Merle d'Aubigné scores, while radiological assessment was performed using the Tönnis score.

RESULTS

Fifteen women and 25 men were included in the study, with a mean age of 36.3 years. Two patients had bilateral symptomatic involvement. Of the 42 cases, there were 13 cam type, 11 pincer type and 18 mixed. Preoperatively, 31 hips were classified as poor and moderate, and 11 as good according to the Merle d'Aubigné scale. The preoperative Tönnis radiological classification showed grade 0 in half of the cases. The mean duration of follow-up was 24 months (12 to 37). The final postoperative Merle d'Aubigné scores classified 7 cases as poor or moderate, and 35 as good to excellent (p<0.05). The postoperative Tönnis score showed no significant variation. As complications, one patient had heterotopic ossification, and three had trochanteric nonunion requiring refixation.

CONCLUSION

Our results suggest that the LQC technique for the treatment of patients with PFA shows satisfactory short-term results with a low complication rate. To our knowledge, this is the first report of results of the surgical procedure for hip dislocation in our region.

Mutualistic and antagonistic interactions differ in wild and domesticated papaya (Carica papaya) in its centre of origin

Shifts in phenotypes derived from the domestication syndromes impact plant performance but may also affect interactions with other species in the community (e.g. mutualists and antagonists). Moreover, plantations often differ from the natural conditions experienced by the wild relatives of cultivated plants, potentially altering the nature of ecological interactions. However, apart from herbivory, little is known about how domestication and cultivation practices (e.g. insecticide application) can modify multiple ecological interactions simultaneously in wild and domesticated plants. In four sites on the Yucatan Peninsula, we compared the diversity of mutualists (e.g. moths) and antagonists (e.g. viruses) in wild and domesticated plants of papaya. For each individual, we recorded floral visitors and rates of visitation at three time periods during the day. We recorded type and percentage of damage by antagonists in three leaves of all individuals. Finally, we explored if plant sex had an effect on the interaction with floral visitors. The main floral visitors were ants and Trigona species, whereas viruses caused the main type of foliar damage. Wild individuals had a higher diversity and visitation rate of floral visitors, and less foliar damage from antagonists. Wild male individuals were more visited, but we observed a similar amount and diversity of damage in both sexes. The time of day did not have an effect on diversity of floral visitors. Together, cultivation practices and domestication appear to have an effect on the reduction in diversity of floral visitors in domesticated papaya, as well as an increase in foliar damage.

Secretion of biologically active pancreatitis-associated protein I (PAP) by genetically modified dairy Lactococcus lactis NZ9000 in the prevention of intestinal mucositis

Background

Mucositis is one of the most relevant gastrointestinal inflammatory conditions in humans, generated by the use of chemotherapy drugs, such as 5-fluoracil (5-FU). 5-FU-induced mucositis affects 80% of patients undergoing oncological treatment causing mucosal gut dysfunctions and great discomfort. As current therapy drugs presents limitations in alleviating mucositis symptoms, alternative strategies are being pursued. Recent studies have shown that the antimicrobial pancreatitis-associated protein (PAP) has a protective role in intestinal inflammatory processes. Indeed, it was demonstrated that a recombinant strain of Lactococcus lactis expressing human PAP (LL-PAP) could prevent and improve murine DNBS-induced colitis, an inflammatory bowel disease (IBD) that causes severe inflammation of the colon. Hence, in this study we sought to evaluate the protective effects of LL-PAP on 5-FU-induced experimental mucositis in BALB/c mice as a novel approach to treat the disease.

Results

Our results show that non-recombinant L. lactis NZ9000 have antagonistic activity, in vitro, against the enteroinvasive gastrointestinal pathogen L. monocytogenes and confirmed PAP inhibitory effect against Opportunistic E. faecalis. Moreover, L. lactis was able to prevent histological damage, reduce neutrophil and eosinophil infiltration and secretory Immunoglobulin-A in mice injected with 5-FU. Recombinant lactococci carrying antimicrobial PAP did not improve those markers of inflammation, although its expression was associated with villous architecture preservation and increased secretory granules density inside Paneth cells in response to 5-FU inflammation.

Conclusions

We have demonstrated for the first time that L. lactis NZ9000 by itself, is able to prevent 5-FU-induced intestinal inflammation in BALB/c mice. Moreover, PAP delivered by recombinant L. lactis strain showed additional protective effects in mice epithelium, revealing to be a promising strategy to treat intestinal mucositis.

Surface functionalization for tailoring the aggregation and magnetic behaviour of silica-coated iron oxide nanostructures

We report here a detailed structural and magnetic study of different silica nanocapsules containing uniform and highly crystalline maghemite nanoparticles. The magnetic phase consists of 5 nm triethylene glycol (TREG)- or dimercaptosuccinic acid (DMSA)-coated maghemite particles. TREG-coated nanoparticles were synthesized by thermal decomposition. In a second step, TREG ligands were exchanged by DMSA. After the ligand exchange, the ζ potential of the particles changed from -10 to -40 mV, whereas the hydrodynamic size remained constant at around 15 nm. Particles coated by TREG and DMSA were encapsulated in silica following a sol-gel procedure. The encapsulation of TREG-coated nanoparticles led to large magnetic aggregates, which were embedded in coalesced silica structures. However, DMSA-coated nanoparticles led to small magnetic clusters inserted in silica spheres of around 100 nm. The final nanostructures can be described as the result of several competing factors at play. Magnetic measurements indicate that in the TREG-coated nanoparticles the interparticle magnetic interaction scenario has not dramatically changed after the silica encapsulation, whereas in the DMSA-coated nanoparticles, the magnetic interactions were screened due to the function of the silica template. Moreover, the analysis of the AC susceptibility suggests that our systems essentially behave as cluster spin glass systems.

Population dynamics and damage caused by the leafminer Liriomyza huidobrensis Blanchard (Diptera: Agromyzidae), on seven potato processing varieties grown in temperate environment

The leafminer Liriomyza huidobrensis Blanchard is considered a key pest for potatoes in Argentina. Population dynamics and leaf damage caused by the leafminer on seven selected potato processing varieties were assessed at Balcarce during the 2002 and 2003 growing seasons. Adult population dynamic was monitored using yellow sticky traps, while leaf damage (punctures and mines) was assessed using a damage index scale from low to severe. Liriomyza huidobrensis adults were present throughout the growing season and the population increased along crop development. The same was true for all varieties regarding larval damage, being low on early crop stages and severe late in the season. Varieties were grouped in two different categories according to damage scale index. Shepody, Kennebec, Frital and Innovator showed a higher damage index when compared with Santana, Ranger Russet and Russet Burbank, which exhibited a lower damage. Moreover, it could be assumed that damage was related to the foliage greenness, with light green colored varieties (Shepody, Kennebec, Frital and Innovator) being more attractive and affected by L. huidobrensis.

[Practice guideline for the administration of drugs with parenteral nutrition]

The "Y" administering of drugs or administering them during parenteral nutrition should not be a normal practice in daily clinical operations, due to the problems of the possible lack of physio-chemical stability in the lipid emulsion forming the mixture of aminoacids, glucose, lipids, electrolytes, vitamins and oligoelements or the chemistry of the drug itself with these components. Also, the "Y" administration of drugs in parenteral nutrition increases the risk of infection in the catheter, since it is handled much more often. Despite these problems, there are clinical situations (such as preoedema of the lung, inadequate syndrome of the antidiuretic hormone in bone marrow transplants), in which it is necessary to restrict to a minimum the fluids to be perfused. As an example, we could mention Ranitidine in TPN or the elimination of second line peripheric maintenance serum and the administering of other drugs in "Y" using a syringe or microdrop system. The same case as in patients subjected to bone marrow transplants, where due to polypharmacy and transfusions, drugs should be administered in "Y". This study is an updated review of the chemical stability of drugs administered in "Y" or in parenteral nutrition, and the physio-chemical stability of the lipid emulsion.