Do aluminum (Al)-hyperaccumulator and phosphorus (P)-solubilising species assist neighbouring plants sensitive to Al toxicity and P deficiency?

We aimed to evaluate the facilitation effects of an aluminum (Al) hyperaccumulator species bearing cluster roots, Gevuina avellana, on the seedling growth and performance of an Al-intolerant and phosphorus (P)-deficient-sensitive plant, Vaccinium corymbosum. For this, seedlings of G. avellana and V. corymbosum were grown alone or together as follows: i) two G. avellana seedlings, ii) one G. avellana + one V. corymbosum and iii) two V. corymbosum, in soil supplemented with Al (as Al2(SO4)3) and in the control (without Al supplementation). We determined relative growth rate (RGR), photosynthetic rate, chlorophyll concentration, lipid peroxidation and Al and nutrient concentration [Nitrogen (N), P, potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), and sulfur (S)] in leaves and roots of both species. The results showed that, in general, G. avellana did not assist V. corymbosum to enhance its RGR nor reduce its Al uptake. However, G. avellana assisted V. corymbosum in enhanced N acquisition and, consequently, to increase its chlorophyll concentration and photosynthetic rate. Besides, V. corymbosum had lower lipid peroxidation in leaves when grown in the soil with high Al supplementation in association with G. avellana. Our results suggest a facilitating effect of G. avellana to V. corymbosum when grown in soils with high Al concentration, by enhancing chlorophyll concentrations and photosynthetic rate, and decreasing the oxidative damage to lipids.

Description of a new ultrasound sign to distinguish Crohn's anal fistula from cryptoglandular fistula: The rosary sign.

AIM: Endoanal and endorectal ultrasound are essential diagnostic tools for perianal fistula. Recent studies have examined ultrasound signs that help differentiate cryptoglandular anal fistula from perianal fistulizing Crohn's disease. The main aim of this work was to describe a new ultrasound sign for perianal fistula and to evaluate its ability to differentiate Crohn's disease from cryptoglandular anal fistula. METHOD: This study included 363 patients (113 women; mean age 46.5 ± 14.3 years). Overall, 287 (79.1%) patients had a cryptoglandular perianal fistula and 76 (20.9%) had fistulizing Crohn's disease. All patients underwent three-dimensional anal endosonography for perianal fistula. The reading was carried out by two observers. RESULTS: Observer 1, who was an experienced sonographer and colorectal surgeon, observed the ultrasound sign in 120 patients (33.1%), while observer 2, who was inexperienced, observed it in 129 patients (35.5%). The overall interobserver agreement was 67.22%. The Kappa coefficient measuring interobserver agreement was 0.273 (0.17-0.38). Among those patients with Crohn's disease, 48.68% had the sign and 16% did not (p = 0.001). A logistic regression study showed that the sign was a predictor of Crohn's disease (p = 0.001), with an odds ratio of 2.33 (1.39-3.91). Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 38.68%, 71.08%, 30.83%, 83.95% and 66.39%, respectively. CONCLUSION: This study provides a new ultrasound sign for perianal fistula (the rosary sign) in patients with Crohn's disease. The sign can be used to differentiate Crohn's disease from other types of fistula. This is useful in the management of patients with anal fistula.

Ecophysiological Performance of Proteaceae Species From Southern South America Growing on Substrates Derived From Young Volcanic Materials.

Southern South American Proteaceae thrive on young volcanic substrates, which are extremely low in plant-available phosphorus (P). Most Proteaceae exhibit a nutrient-acquisition strategy based on the release of carboxylates from specialized roots, named cluster roots (CR). Some Proteaceae colonize young volcanic substrates which has been related to CR functioning. However, physiological functioning of other Proteaceae on recent volcanic substrates is unknown. We conducted an experiment with seedlings of five Proteaceae (Gevuina avellana, Embothrium coccineum, Lomatia hirsuta, L. ferruginea, and L. dentata) grown in three volcanic materials. Two of them are substrates with very low nutrient concentrations, collected from the most recent deposits of the volcanoes Choshuenco and Calbuco (Chile). The other volcanic material corresponds to a developed soil that exhibits a high nutrient availability. We assessed morphological responses (i.e., height, biomass, and CR formation), seed and leaf macronutrient and micronutrient concentrations and carboxylates exuded by roots. The results show that G. avellana was less affected by nutrient availability of the volcanic substrate, probably because it had a greater nutrient content in its seeds and produced large CR exuding carboxylates that supported their initial growth. Embothrium coccineum exhibited greater total plant height and leaf P concentration than Lomatia species. In general, in all species leaf macronutrient concentrations were reduced on nutrient-poor volcanic substrates, while leaf micronutrient concentrations were highly variable depending on species and volcanic material. We conclude that Proteaceae from temperate rainforests differ in their capacity to grow and acquire nutrients from young and nutrient-poor volcanic substrates. The greater seed nutrient content, low nutrient requirements (only for G. avellana) and ability to mobilize nutrients help explain why G. avellana and E. coccineum are better colonizers of recent volcanic substrates than Lomatia species.

Influence of robotics in surgical complication rate in elderly population with rectal cancer.

BACKGROUND: Rectal cancer surgery is a technically complex procedure. Moreover, short-term outcomes show high rate of complications especially in elderly and laparoscopic surgery has not demonstrated to be able to reduce this complication rate. Robotics has several advantages in pelvic surgical procedures, which could have an impact in complication rates in elderly patients. AIMS: The aim of our study is to demonstrate whether robotic surgery has any influence on the reduction of complications in the aged population undergoing rectal cancer. METHODS: We performed a retrospective analysis of a prospective database of 151 patients who underwent robotic surgery for rectal cancer. We divided our population into three groups: under 65-year-old, between 65- and 80-year-old and above 80-year-old. We recorded complications in each group intra and post procedure. RESULTS: The present study included 151 patients (94 males). Of them, 77 patients were under 66 year old, 63 patients were between 66 and 79 year old and 11 patients were 80 year old and above. The analysis showed conversion rates of 10.38%, 13.69%, 27.27%, and the complication rate of 23.4%, 23.8%, and 27.3% in each group. Univariate analysis showed no differences between the three groups. Nevertheless, there were statistical differences from BMI, ASA and neoadjuvant therapy. In multivariant analysis only neoadjuvant therapy was significant. CONCLUSIONS: Robotic approach does not decrease complications in elderly population and conversion is similar in these age groups. So we should not rule out robotic surgery in elderly patients, although we must select each case with a multidisciplinary approach.

Autologous Platelet-Rich Plasma in the Treatment of Perianal Fistula in Crohn's Disease.

AIM: To assess clinical healing in patients with perianal Crohn's disease with local intrafistular injection of autologous platelet-rich plasma. METHOD: The pilot study was conducted at a single centre between January 2013 and December 2015. Autologous platelet-rich plasma was prepared in platelet-rich and platelet-poor fractions for local intrafistular injection in patients with proven, established perianal Crohn's disease. Patients were permitted biological therapies, and the Perianal Crohn's Disease Activity Index was recorded. Patients were followed for 48 weeks for clinical signs of healing (complete, partial or non-healing), monitoring fistula drainage, closure and epithelialization. RESULTS: The study included 29 patients (19 males; mean age 38 ± 12.8 years) with four exclusions in the operating room because surgery was not indicated and four lost to follow-up. Five adverse events were recorded, with two requiring the drainage of abscess collections. Of the 21 patients assessable at 24 weeks, there was complete healing, partial healing and non-healing in 7 (33.3%), 8 (38.1%) and 6 (28.6%) patients, respectively. By 48 weeks, there was complete healing, partial healing and non-healing in 6 (40%), 6 (40%) and 3 (20%) patients, respectively, with a reduction in the number of visible external fistula openings at both time points (P = 0.021). By the end of the study, there was a higher trend of healing if biological therapies were continued (85.7% with biologics vs. 75% without, P = 0.527), but there were no statistically significant differences and no differences in the Perianal Crohn's Disease Activity Index. CONCLUSION: Autologous platelet-rich plasma is safe in patients with perianal Crohn's disease, with an acceptable healing rate over a medium-term follow-up, particularly if biological therapies are used concomitantly.

Treatment of transsphincteric fistula-in-ano with growth factors from autologous platelets: results of a phase II clinical trial.

PURPOSE: The aim of this paper is to evaluate to the safety, feasibility and efficacy of a novel treatment for transsphincteric cryptoglandular fistula: injection of autologous plasma rich in growth factors (PRGF) into the fistula tract accompanied by sealing using a fibrin plug created from the activated platelet-poor fraction of the same plasma. METHOD: This article is a prospective, phase II clinical trial. The procedure was externally audited. Thirty-six patients diagnosed with transsphincteric fistula-in-ano were included. All patients underwent follow-up examinations at 1 week and again at 3, 6 and 12 months after discharge. Main outcome measures safety (number of adverse events), feasibility and effectiveness of the treatment. RESULTS: A total of 36 patients received the study treatment, with the procedure found to be feasible in all patients. A total of seven adverse events (AE) related to the injected product or surgical procedure were identified in 4 of 36 patients. At the end of the follow-up period (12 months), 33.3% of patients (12/36) had achieved complete fistula healing and 11.1% of patients (4/36) had achieved partial healing. In total, this amounted to 44.4% of patients (16/36) being asymptomatic at final follow-up. In successfully healed patients, a gradual reduction in pain was observed, as measured using a Visual Analog Scale (VAS) (p = 0.0278). Compared to baseline, a significant improvement in Wexner score was seen in patients achieving total or partial healing of the fistula (p = 0.0195). CONCLUSIONS: The study treatment was safe and feasible, with apparently modest efficacy rates. Continence and pain improvement following treatment may be considered predictive factors for healing.

Ultrasonographic evidence of Gatekeeper™ prosthesis migration in patients treated for faecal incontinence: a case series.

BACKGROUND: Faecal incontinence (FI) is both a medical and social problem, with an underestimated incidence. For patients with internal anal sphincter damage, implantation of biomaterial in the anal canal is a recognised treatment option. One such material, Gatekeeper™, has previously shown promising short- and medium-term results without any major complications, including displacement. The main aim of the present study is to assess the degree to which displacement of Gatekeeper prostheses may occur and to determine whether this is associated with patient outcomes. METHODS: Seven patients (six females) with a mean age of 55.6 years [50.5-57.2] and a mean FI duration of 6 ± 2 years were prospectively enrolled in the study. Each subject was anaesthetised and underwent implantation of six prostheses in the intersphincteric region, guided by endoanal 3D ultrasound (3D-EAU). Follow-up was performed at post-interventional months 1, 3, and 12 (median 12 ± 4 months), during which data were obtained from a defaecation diary, Wexner scale assessment, anorectal manometry (ARM), 3D-EAU, and a health status and quality of life questionnaire (FIQL). RESULTS: At 3-month follow-up, 3D-EAU revealed displacement of 24/42 prostheses in 5/7 patients. Of these, 15 had migrated to the lower portion and 9 to the upper portion of the anal canal and rectum. Despite this migration, treatment was considered successful in 3/7 patients. In one patient, it was necessary to remove a prosthesis due to spontaneous extrusion. CONCLUSIONS: We have shown that displacement of the Gatekeeper™ prosthesis occurs, but is not associated with poorer clinical outcomes.

Learning curve in robotic rectal cancer surgery: current state of affairs.

INTRODUCTION: Robotic-assisted rectal cancer surgery offers multiple advantages for surgeons, and it seems to yield the same clinical outcomes as regards the short-time follow-up of patients compared to conventional laparoscopy. This surgical approach emerges as a technique aiming at overcoming the limitations posed by rectal cancer and other surgical fields of difficult access, in order to obtain better outcomes and a shorter learning curve. MATERIAL AND METHODS: A systematic review of the literature of robot-assisted rectal surgery was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The search was conducted in October 2015 in PubMed, MEDLINE and the Cochrane Central Register of Controlled Trials, for articles published in the last 10 years and pertaining the learning curve of robotic surgery for colorectal cancer. It consisted of the following key words: "rectal cancer/learning curve/robotic-assisted laparoscopic surgery". RESULTS: A total of 34 references were identified, but only 9 full texts specifically addressed the analysis of the learning curve in robot-assisted rectal cancer surgery, 7 were case series and 2 were non-randomised case-comparison series. Eight papers used the cumulative sum (CUSUM) method, and only one author divided the series into two groups to compare both. The mean number of cases for phase I of the learning curve was calculated to be 29.7 patients; phase II corresponds to a mean number 37.4 patients. The mean number of cases required for the surgeon to be classed as an expert in robotic surgery was calculated to be 39 patients. CONCLUSION: Robotic advantages could have an impact on learning curve for rectal cancer and lower the number of cases that are necessary for rectal resections.

Molecular characterisation of a calmodulin gene, VcCaM1, that is differentially expressed under aluminium stress in highbush blueberry.

Calmodulin (CaM), a small acidic protein, is one of the best characterised Ca(2+) sensors in eukaryotes. This Ca(2+) -regulated protein plays a critical role in decoding and transducing environmental stress signals by activating specific targets. Many environmental stresses elicit changes in intracellular Ca(2+) activity that could initiate adaptive responses under adverse conditions. We report the first molecular cloning and characterisation of a calmodulin gene, VcCaM1 (Vaccinium corymbosum Calmodulin 1), in the woody shrub, highbush blueberry. VcCaM1 was first identified as VCAL19, a gene induced by aluminium stress in V. corymbosum L. A full-length cDNA of VcCaM1 containing a 766-bp open reading frame (ORF) encoding 149 amino acids was cloned from root RNA. The sequence encodes four Ca(2+) -binding motifs (EF-hands) and shows high similarity (99%) with the isoform CaM 201 of Daucus carota. Expression analyses showed that following Al treatment, VcCaM1 message level decreased in roots of Brigitta, an Al-resistant cultivar, and after 48 h, was lower than in Bluegold, an Al-sensitive cultivar. VcCAM1 message also decreased in leaves of both cultivars within 2 h of treatment. Message levels in leaves then increased by 24 h to control levels in Brigitta, but not in Bluegold, but then decreased again by 48 h. In conclusion, VcCaM1 does not appear to be directly involved in Al resistance, but may be involved in improved plant performance under Al toxicity conditions through regulation of Ca(2+) homeostasis and antioxidant systems in leaves.

Excess manganese differentially inhibits photosystem I versus II in Arabidopsis thaliana.

The effects of exposure to increasing manganese concentrations (50-1500 µM) from the start of the experiment on the functional performance of photosystem II (PSII) and photosystem I (PSI) and photosynthetic apparatus composition of Arabidopsis thaliana were compared. In agreement with earlier studies, excess Mn caused minimal changes in the PSII photochemical efficiency measured as F(v)/F(m), although the characteristic peak temperature of the S(2/3)Q(B) (-) charge recombinations was shifted to lower temperatures at the highest Mn concentration. SDS-PAGE and immunoblot analyses also did not exhibit any significant change in the relative abundance of PSII-associated polypeptides: PSII reaction centre protein D1, Lhcb1 (major light-harvesting protein of LHCII complex), and PsbO (OEC33, a 33 kDa protein of the oxygen-evolving complex). In addition, the abundance of Rubisco also did not change with Mn treatments. However, plants grown under excess Mn exhibited increased susceptibility to PSII photoinhibition. In contrast, in vivo measurements of the redox transients of PSI reaction centre (P700) showed a considerable gradual decrease in the extent of P700 photooxidation (P700(+)) under increased Mn concentrations compared to control. This was accompanied by a slower rate of P700(+) re-reduction indicating a downregulation of the PSI-dependent cyclic electron flow. The abundance of PSI reaction centre polypeptides (PsaA and PsaB) in plants under the highest Mn concentration was also significantly lower compared to the control. The results demonstrate for the first time that PSI is the major target of Mn toxicity within the photosynthetic apparatus of Arabidopsis plants. The possible involvement mechanisms of Mn toxicity targeting specifically PSI are discussed.

Low temperature responses of Nothofagus dombeyi and Nothofagus nitida, two evergreen species from south central Chile.

Nothofagus dombeyi (Mirb.) Blume and Nothofagus nitida (Phil.) Krasser are closely related evergreen trees native to south central Chile. Nothofagus dombeyi is a pioneer in habitats subject to high daytime irradiances and nighttime freezing temperatures and has a wider altitudinal and latitudinal distribution than N. nitida, which is restricted to more oceanic climates. We postulated that N. dombeyi has a greater cold-acclimation capacity, expressed as a greater capacity to maintain a functional photosynthetic apparatus at low temperatures, than N. nitida. Because cold-acclimation may be related to the accumulation of cryoprotective substances, we investigated relationships between ice nucleation temperature (IN), freezing temperature (FT), and the temperature causing injury to 50% of the leaf tissues (LT(50)) on the one hand, and concentrations of total soluble carbohydrates (TSC), starch and proline on the other hand. Observations were made throughout a seasonal cycle in adults and seedlings in the field and in seedlings in the laboratory under cold-acclimation inductive and non-inductive conditions. In adults, LT(50) values were lower in N. dombeyi than in N. nitida, suggesting that N. dombeyi is the more frost tolerant species. Adults of both species tolerated freezing in autumn and winter but not in spring and summer. In the fall and winter, seedlings of N. dombeyi had a much lower LT(50) than those of N. nitida. Nothofagus nitida seedlings, in autumn and winter, exhibited freezing avoidance mechanisms. Although elevated TSC and proline concentrations may contribute to freezing tolerance in adults of both species, an increase in proline concentration is unlikely to be the dominant frost tolerance response in adults because proline concentrations were higher in N. nitida than in N. dombeyi. In seedlings, however, there were large differences in proline accumulation between species that may account for the difference between them in freezing tolerance. Starch concentration in both species decreased during winter. Chlorophyll fluorescence indicated that maximal photochemical efficiency (F(v)/F(m)) remained at optimal values (~0.8) throughout the year. The effective photochemical efficiency of PSII (PhiPSII) and relative electron transport rates (ETR(r)) decreased in winter in both species. In seedlings, fluorescence parameters were more affected in winter in N. nitida than in N. dombeyi. We concluded that adults and seedlings of N. dombeyi are hardier than adults and seedlings of N. nitida, which is consistent with its wider latitudinal and altitudinal distribution.