Influence of Deep Sedation in Intensive Care Medicine Memories of Critical COVID-19 Survivors.

Introduction: Critical care survivors sustain a variety of sequelae after intensive care medicine (ICM) admission, and the Coronavirus Disease 2019 (COVID-19) pandemic has added further challenges. Specifically, ICM memories play a significant role, and delusional memories are associated with poor outcomes post-discharge including a delayed return to work and sleep problems. Deep sedation has been associated with a greater risk of perceiving delusional memories, bringing a move toward lighter sedation. However, there are limited reports on post-ICM memories in COVID-19, and influence of deep sedation has not been fully defined. Therefore, we aimed to evaluate ICM-memory recall in COVID-19 survivors and their relation with deep sedation. Materials/Methods: Adult COVID-19 ICM survivors admitted to a Portuguese University Hospital between October 2020 and April 2021 (second/third "waves") were evaluated 1 to 2 months post-discharge using "ICU Memory Tool," to assess real, emotional, and delusional memories. Results: The study included 132 patients (67% male; median age = 62 years, Acute Physiology and Chronic Health Evaluation [APACHE]-II = 15, Simplified Acute Physiology Score [SAPS]-II = 35, ICM stay = 9 days). Approximately 42% received deep sedation (median duration = 19 days). Most participants reported real (87%) and emotional (77%) recalls, with lesser delusional memories (36.4%). Deeply sedated patients reported significantly fewer real memories (78.6% vs 93.4%, P = .012) and increased delusional memories (60.7% vs 18.4%, P < .001), with no difference in emotional memories (75% vs 80.4%, P = .468). In multivariate analysis, deep sedation had a significant, independent association with delusional memories, increasing their likelihood by a factor of approximately 6 (OR = 6.274; 95% confidence interval = 1.165-33.773, P = .032), without influencing real (P = .545) or emotional (P = .133) memories. Conclusions: This study contributes to a better understanding of the potential adverse effects of deep sedation on ICM memories in critical COVID-19 survivors, indicating a significant, independent association with the incidence of delusional recalls. Although further studies are needed to support these findings, they suggest that strategies targeted to minimize sedation should be favored, aiming to improve long-term recovery.

Biotechnological production of specialty aromatic and aromatic-derivative compounds.

Aromatic compounds are an important class of chemicals with different industrial applications. They are usually produced by chemical synthesis from petroleum-derived feedstocks, such as toluene, xylene and benzene. However, we are now facing threats from the excessive use of fossil fuels causing environmental problems such as global warming. Furthermore, fossil resources are not infinite, and will ultimately be depleted. To cope with these problems, the sustainable production of aromatic chemicals from renewable non-food biomass is urgent. With this in mind, the search for alternative methodologies to produce aromatic compounds using low-cost and environmentally friendly processes is becoming more and more important. Microorganisms are able to produce aromatic and aromatic-derivative compounds from sugar-based carbon sources. Metabolic engineering strategies as well as bioprocess optimization enable the development of microbial cell factories capable of efficiently producing aromatic compounds. This review presents current breakthroughs in microbial production of specialty aromatic and aromatic-derivative products, providing an overview on the general strategies and methodologies applied to build microbial cell factories for the production of these compounds. We present and describe some of the current challenges and gaps that must be overcome in order to render the biotechnological production of specialty aromatic and aromatic-derivative attractive and economically feasible at industrial scale.

Video-Assisted Anal Fistula Treatment (VAAFT) for complex anorectal fistula: efficacy and risk factors for failure at 3-year follow-up.

BACKGROUND: The aim of this study was to assess the 3-year objective and subjective outcomes of patients with complex anorectal fistula treated with Video-Assisted Anal Fistula Treatment (VAAFT). Furthermore, we evaluated the risk factors associated with recurrence. METHODS: All consecutive patients with complex anorectal fistula who underwent VAAFT in Beata Vergine Hospital of Mendrisio, Switzerland, from January 2013 to January 2016, were enrolled. Patients with suspicion or diagnosis of Crohn's disease, malignancy, previous history of radiotherapy or radical pelvic surgery were excluded. Preoperative clinical assessment based upon medical history, physical examination and endosonography, was performed in all patients. Data regarding subjective outcomes (the Patient Global Impression of Improvement, patient satisfaction scores and Wexner score), objective cure rate (absence of fistula at clinical examination), and adverse events were collected during follow-up. Uni and multivariate analysis were performed to investigate outcomes. RESULTS: One hundred and four patients had VAAFT. At 3-year follow-up, 96 patients (92.3%) were available for the evaluation. At 3 years after surgery, 81 of 96 patients (84.4%) declared themselves cured (p = 0.60). Similarly, at 3-year evaluation, 80 of 96 patients (83.3%) were objectively cured (p = 0.52). No serious intraoperative or postoperative complications were reported. All recurrences were treated with a repeat VAAFT procedure resulting in a complete healing. Uni and multivariate analysis of variables potentially involved in the failure of VAAFT showed that age ≥ 50 years was the only factor associated at risk of recurrence. CONCLUSIONS: VAAFT is a highly effective safe procedure for the treatment of anorectal fistula, with a low recurrence rate at 3-year follow-up. However, our study demonstrated that age ≥ 50 years is a risk factor for failure of VAAFT.

Noninvasive prenatal testing: benefits and limitations of the available tests.

BACKGROUND: The „gold standard“ for prenatal diagnosis of aneuploidies is provided by the karyotype, which has high accuracy, but is dependent on invasive procedures, which generate risk of fetal loss. Different methodologies of development of noninvasive prenatal genetic tests (NIPT) for tracking aneuploidies, including sex chromosomes, have been made available for clinical use, for some microdeletions and triploids and for exclusion of paternity. These exams make use of three methodological tools: s-MPS, t-MPS and SNP. Genetic tests, despite the high cost, cover a broader range of clinical applications, have the advantage that can be performed early, with high accuracy, and low false positive rate. Type of article: Review. SETTING: Department of Obstetrics and Gynecology, Science College of Santa Casa of São Paulo (FSMSCSP), São Paulo-SP, Brazil. DESIGN AND METHODS: This study was a non-asystematic review, which searched PubMed / MEDLINE as a research source and aimed at the compilation of data, which allowed approaching the evolution, the technical and methodological advances of the available tests, the recognition of its benefits, limitations and future perspectives on NIPT. CONCLUSION: NIPT stand out for being applied earlier during the pregnancy with high accuracy and low false-positive rates, including a broad spectrum of clinical applications. The t-MPS is a recent technique used to evaluate aneuploidy that shows greater accuracy and lower cost than the s-MPS, but that is limited to being applied only to the most common aneuploidies. The SNP technique can search for more genetic conditions, besides presenting better accuracy.

Accuracy of p57KIP2 compared with genotyping to diagnose complete hydatidiform mole: a systematic review and meta-analysis.

BACKGROUND: Distinguishing hydatidiform moles (HMs) from nonmolar specimens and the subclassification of HM are important because complete hydatidiform mole (CHM) is associated with an increased risk of development of gestational trophoblastic neoplasia. However, diagnosis based solely on morphology has poor inter-observer reproducibility. Recent studies have demonstrated that the use of p57KIP2 immunostaining improves diagnostic accuracy for CHM. OBJECTIVES: To evaluate the accuracy of p57KIP2 immunostaining compared with molecular genotyping for the diagnosis of CHM. SEARCH STRATEGY: Major databases were searched from inception to March 2017 using the terms 'hydatidiform mole', 'p57', and 'genotyping', with their variations, and the search limit for the relevant study design. SELECTION CRITERIA: Any cross-sectional study, case series, case-control study, cohort study, or clinical trial that evaluated the accuracy of p57KIP2 immunostaining for the diagnosis of CHM compared with genotyping was included. Case reports, narrative reviews, expert opinions, and animal testing were excluded. DATA COLLECTION AND ANALYSIS: Extracted accuracy data were tabulated and pooled using a hierarchical bivariate random effects model. MAIN RESULTS: Bivariate meta-analysis produced a summary sensitivity of 0.984 (95% CI: 0.916-1.000) and specificity of 0.625 (95% CI: 0.503-0.736) with significant heterogeneity for specificity (I2 = 71.8, chi-square P = 0.029). The pooled summary diagnostic odds ratio was 56.54 (95% CI: 11.03-289.74) with no heterogeneity (I2 = 0.00%, chi-square P = 0.67). The diagnostic performance of the test was high with an area under the curve of (AUC) 0.980. CONCLUSIONS: p57KIP2 immunostaining is accurate when diagnosing CHM. It can be used as an adjunct test in a combination algorithmic approach. TWEETABLE ABSTRACT: A meta-analysis to evaluate the accuracy of p57KIP2 compared with genotyping to diagnose CHM.

Heterologous production of resveratrol in bacterial hosts: current status and perspectives.

The polyphenol resveratrol (3,5,4'-trihydroxystilbene) is a well-known plant secondary metabolite, commonly used as a medical ingredient and a nutritional supplement. Due to its health-promoting properties, the demand for resveratrol is expected to continue growing. This stilbene can be found in different plants, including grapes, berries (blackberries, blueberries and raspberries), peanuts and their derived food products, such as wine and juice. The commercially available resveratrol is usually extracted from plants, however this procedure has several drawbacks such as low concentration of the product of interest, seasonal variation, risk of plant diseases and product stability. Alternative production processes are being developed to enable the biotechnological production of resveratrol by genetically engineering several microbial hosts, such as Escherichia coli, Corynebacterium glutamicum, Lactococcus lactis, among others. However, these bacterial species are not able to naturally synthetize resveratrol and therefore genetic modifications have been performed. The application of emerging metabolic engineering offers new possibilities for strain and process optimization. This mini-review will discuss the recent progress on resveratrol biosynthesis in engineered bacteria, with a special focus on the metabolic engineering modifications, as well as the optimization of the production process. These strategies offer new tools to overcome the limitations and challenges for microbial production of resveratrol in industry.

Metal fractionation in sludge from sewage UASB treatment.

This study evaluates the trace metal composition and fractionation in sludge samples from anaerobic sewage treatment plants from six cities in Brazil. Ten metals were evaluated: Ni, Mn, Se, Co, Fe, Zn, K, Cu, Pb and Cr. Specific methanogenic activity of the sludge was also evaluated using acetic acid as the substrate. Among the essential trace metals for anaerobic digestion, Se, Zn, Ni and Fe were found at a high percentage in the organic matter/sulfide fraction in all sludge samples analyzed. These metals are less available for microorganisms than other metals, i.e., Co and K, which were present in significant amounts in the exchangeable and carbonate fractions. Cu is not typically reported as an essential metal but as a possible inhibitor. One of the samples showed a total Cu concentration close to the maximal amount allowed for reuse as fertilizer. Among the non-essential trace metals, Pb was present in all sludge samples at similar low concentrations and was primarily present in the residual fraction, demonstrating very low availability. Cr was found at low concentrations in all sludge samples, except for the sludge from STP5; interestingly, this sludge presented the lowest specific methanogenic activity, indicating possible Cr toxicity.

Hormonal contraceptive use before hCG remission does not increase the risk of gestational trophoblastic neoplasia following complete hydatidiform mole: a historical database review.

OBJECTIVE: To re-evaluate the safety of hormonal contraceptives (HC) after uterine evacuation of complete hydatidiform mole (CHM). DESIGN: Historical database review. SETTING: Charing Cross Hospital Gestational Trophoblastic Disease Centre, London, United Kingdom. POPULATION: Two thousand four hundred and twenty-three women with CHM of whom 154 commenced HC while their human chorionic gonadotropin (hCG) was still elevated, followed between 2003 and 2012. METHODS: We compared time to hCG remission between HC users and nonusers. The relationship between HC use and gestational trophoblastic neoplasia (GTN) development was assessed. The relationship between HC use and a high International Federation of Gynecology and Obstetrics (FIGO) risk score was determined. MAIN OUTCOME MEASURES: Time to hCG remission, risk of developing postmolar GTN and proportion of women with high FIGO risk score. RESULTS: No relationship was observed between HC use with mean time to hCG remission (HC users versus non-users: 12 weeks in both, P = 0.19), GTN development (HC users versus non-users: 20.1 and 16.7%, P = 0.26) or high-risk FIGO score (HC users versus nonusers: 0% and 8%, P = 0.15). Moreover, no association between HC and GTN development was found, even when an age-adjusted model was used (OR = 1.37, 95% CI 0.91-2.08, P = 0.13). CONCLUSIONS: The use of current HC is not associated with development of postmolar GTN or delayed time to hCG remission. Therefore, HC can be safely used to prevent a new conception following CHM regardless of hCG level. TWEETABLE ABSTRACT: Non-concurrent cohort study to re-evaluate the safety of low dose HCs after uterine evacuation of CHM.

Biotechnological production of γ-decalactone, a peach like aroma, by Yarrowia lipolytica.

The request for new flavourings increases every year. Consumer perception that everything natural is better is causing an increase demand for natural aroma additives. Biotechnology has become a way to get natural products. γ-Decalactone is a peach-like aroma widely used in dairy products, beverages and others food industries. In more recent years, more and more studies and industrial processes were endorsed to cost-effect this compound production. One of the best-known methods to produce γ-decalactone is from ricinoleic acid catalyzed by Yarrowia lipolytica, a generally regarded as safe status yeast. As yet, several factors affecting γ-decalactone production remain to be fully understood and optimized. In this review, we focus on the aromatic compound γ-decalactone and its production by Y. lipolytica. The metabolic pathway of lactone production and degradation are addressed. Critical analysis of novel strategies of bioprocess engineering, metabolic and genetic engineering and other strategies for the enhancement of the aroma productivity are presented.

Anti-inflammatory and antiproliferative evaluation of 4ß-cinnamoyloxy,1ß,3α-dihydroxyeudesm-7,8-ene from Verbesina persicifolia and derivatives.

The anti-inflammatory and antiproliferative activities of 4ß-cinnamoyloxy,1ß,3α-dihydroxyeudesm-7,8-ene (1) and of three derivatives, namely diacetate (2), hydrogenate (3) and diacetate hydrogenate (4) were evaluated. All derivatives exert an anti-inflammatory effect significantly lower than that exerted by 1. Otherwise, both the lead compound and 2-4 showed a comparable antiproliferative activity on human tumor cell lines. The investigation of the mechanism of action accountable for cytotoxicity highlighted the capacity to impair mitochondrial functions through two different pathways, depending on chemical structure. In particular, the lead compound 1 and derivative 3 are able to induce mitochondrial permeability transition, while derivatives 2 and 4 inhibit Complex II in the respiratory chain.

Chemotherapy is not needed when complete evacuation of gestational choriocarcinoma leads to hCG normalization.

BACKGROUND: The standard treatment for gestational choriocarcinoma is chemotherapy. OBJECTIVE: To describe the risk of recurrence with expectant management of gestational choriocarcinoma that has reached a normal human chorionic gonadotropin level after tumor removal without adjuvant chemotherapy. METHODS: A retrospective multicenter international cohort study was conducted from 1981 to 2017 involving 11 gestational trophoblastic disease reference centers with patient's follow-up extended until 2023. Clinical and biological data of included patients were extracted from each center's database. The inclusion criteria were i) histological diagnosis of gestational choriocarcinoma in any kind of placental tissue retrieved, ii) spontaneous normalization of human chorionic gonadotropin level following choriocarcinoma retrieval, iii) patient did not receive any oncological treatment for the choriocarcinoma, iv) and at least 6 months of follow-up after the first human chorionic gonadotropin level normalization. RESULTS: Among 80 patients with retrieved gestational choriocarcinoma and whose human chorionic gonadotropin level normalized without any other oncological therapy, none had a recurrence of choriocarcinoma after a median follow-up of 50 months. The median interval between choriocarcinoma excision and human chorionic gonadotropin level normalization was 48 days. The International Federation of Gynecology and Obstetrics/World Health Organization risk score was ≤6 in 93.7% of the cases. CONCLUSIONS: This multicenter international study reports that selected patients with gestational choriocarcinoma managed in gestational trophoblastic disease reference centers did not experience any relapse when the initial tumor evacuation is followed by human chorionic gonadotropin level normalization without any additional treatment. Expectant management may be a safe approach for highly selected patients.

Periodontal inflammation in renal transplant recipients receiving everolimus or tacrolimus - preliminary results.

OBJECTIVE: To compare oral health status between renal transplant recipients (RTRs) receiving tacrolimus (Tac) or everolimus (ERL) as immunosuppressive therapy. DESIGN: This study is a cross-sectional study. METHODS: Thirty-six RTRs receiving Tac and 22 RTRs receiving ERL were included in the study. Age, gender, time since transplant and pharmacological data were recorded for both groups. Oral health status was assessed through the evaluation of teeth, periodontal parameters as well as saliva flow rate and pH. RESULTS: RTRs receiving ERL were older than those receiving Tac. No differences were found between groups concerning oral hygiene habits, oral symptoms, smoking habits, unstimulated and stimulated saliva flow rate and pH, clinical attachment level or the number of decayed, missing and filled teeth. However, RTRs receiving ERL presented lower visible plaque index and lower values for bleeding on probing when compared to RTRs receiving Tac. In addition, RTRs receiving ERL presented a gingival index varying from normal to moderate inflammation whereas RTRs receiving Tac presented a gingival index varying from mild to severe inflammation. CONCLUSIONS: RTRs receiving ERL have lower periodontal inflammation when compared to RTRs receiving Tac.

Management of von Willebrand disease type 3 during pregnancy - 2 cases reports.

BACKGROUND: von Willebrand disease type 3, is an extremely rare condition. It can be severe and potentially life-threatening, particularly in pregnant women during labor and subsequently during early puerperium. Due to its rarity, there is no optimal treatment/management during pregnancy. CASE: We describe two cases of pregnant women with von Willebrand disease type 3, and its successful surveillance and treatment with Haemate P FVIII (human plasma-derived von Willebrand Factor-ristocetin co-factor associated with human coagulation factor VIII), during pregnancy, partum and puerperium. CONCLUSIONS: Daily prophylaxis with Haemate P FVIII in women with von Willebrand disease type 3, starting 2 hours before caesarean section until the 7th day of puerperium, associated with close analytical and clinical surveillance seems to be a safe clinical option.

Impaired post exercise heart rate recovery in anabolic steroid users.

Previous study showed that muscle sympathetic nerve activity (MSNA) was augmented in anabolic steroids users (AASU). In the present study, we tested the hypothesis that the heart rate (HR) responses after maximal exercise testing would be reduced in AASU. 10 male AASU and 10 AAS nonusers (AASNU) were studied. Cardiopulmonary exercise was performed to assess the functional capacity and heart rate recovery. MSNA was recorded directly from the peroneal nerve by microneurography technique. Peak oxygen consumption (VO2) was lower in AASU compared to AASNU (43.66±2.24 vs. 52.70±1.68 ml/kg/min, P=0.005). HR recovery (HRR) at first and second minute was lower in AASU than AASNU (21±2 vs. 27±2 bpm, P=0.02 and 37±4 vs. 45±2 bpm, P=0.05, respectively). MSNA was higher in AASU than AASNU (29±3 vs. 20±1 bursts/min, P=0.01). Further analysis showed a correlation between HRR and MSNA (r=- 0.64, P=0.02), HRR at first minute and peak VO2 (r=0.70, P=0.01) and HRR at second minute and peak VO2 (r=0.62, P=0.02). The exacerbated sympathetic outflow associated with a lower parasympathetic activation after maximal exercise, which impairs heart rate recovery, strengthens the idea of autonomic imbalance in AASU.

Oral habits as risk factors for anterior open bite in the deciduous and mixed dentition - cross-sectional study.

AIM: Anterior open bite (AOB) is an occlusal anomaly commonly associated with oral habits (OH). The aim of this study was to determine the prevalence of OH as a risk factor for the AOB. MATERIALS AND METHODS: A group of children aged between 3 and 12 years were observed. The statistical methodology included independent chi-square test, Fisher's exact test and binary logistic regression. RESULTS: The frequency of oral habits was of 43.5% in the deciduous dentition and 54.2% in the mixed dentition. There was a statistically significant association of pacifier sucking: 61.7 and 16.1 odd ratios (OR), and tongue thrust: 3.9 and 9.2 OR with AOB in both groups, respectively. Thumb sucking occurred only in the deciduous dentition with 5.6 OR. CONCLUSION: OH and AOB have a high frequency in children. They hinder the normal development of dental and skeletal structures. As OH are risk factors for AOB, the damaging habits most frequently associated are: pacifier sucking, thumb sucking, and tongue thrust. Due to the correlation between the prevalence of AOB and OH, prevention strategies incorporating psychological data related to children should be integrated into a national public health programme.

Atmospheric pollution: influence on hospital admissions in paediatric rheumatic diseases.

OBJECTIVE: To investigate the lag structure effects from exposure to atmospheric pollution in acute outbursts in hospital admissions of paediatric rheumatic diseases (PRDs). METHODS: Morbidity data were obtained from the Brazilian Hospital Information System in seven consecutive years, including admissions due to seven PRDs (juvenile idiopathic arthritis, systemic lupus erythematosus, dermatomyositis, Henoch-Schönlein purpura, polyarteritis nodosa, systemic sclerosis and ankylosing spondylitis). Cases with secondary diagnosis of respiratory diseases were excluded. Daily concentrations of inhaled particulate matter (PM(10)), sulphur dioxide (SO(2)) nitrogen dioxide (NO(2)), ozone (O(3)) and carbon monoxide (CO) were evaluated. Generalized linear Poisson regression models controlling for short-term trend, seasonality, holidays, temperature and humidity were used. Lag structures and magnitude of air pollutants' effects were adopted to estimate restricted polynomial distributed lag models. RESULTS: The total number of admissions due to acute outbursts PRD was 1,821. The SO(2) interquartile range (7.79 µg/m(3)) was associated with an increase of 1.98% (confidence interval 0.25-3.69) in the number of hospital admissions due to outcome studied after 14 days of exposure. This effect was maintained until day 17. Of note, the other pollutants, with the exception of O(3), showed an increase in the number of hospital admissions from the second week. CONCLUSION: This study is the first to demonstrate a delayed association between SO(2) and PRD outburst, suggesting that oxidative stress reaction could trigger the inflammation of these diseases.

IL1 gene polymorphisms and unsuccessful dental implants.

OBJECTIVES: This study aimed to analyse the association between polymorphisms in the IL1 gene cluster and failure of dental implants in a Portuguese population. MATERIAL AND METHODS: A total of 155 Caucasian Portuguese subjects were divided into two groups: 100 with successful dental implants and 55 with unsuccessful dental implants. DNA was obtained through an oral mucosa scraping. PCR was used to identify the polymorphisms: single nucleotide changes in positions -889 of IL1A gene and +3953 of IL1B gene. RESULTS: The prevalence of the polymorphisms -889IL1A gene and +3953IL1B gene, determined by the positive result of TGP (Genetic Test for Periodontitis; CGC, Genetics, Portugal), in the studied population rehabilitated with dental implants was of 33.50%. Allele 1 of the IL1B gene was the most prevalent (62.20%), followed by allele 1 of the IL1A gene (54.80%) and the least frequent was allele 2 of IL1B gene (37.40%). Success of dental implants was mainly associated with a negative TGP result, whereas no success was found to be related to a positive result. There were no statistically significant differences between the alleles 1 and 2 of the genes IL1A and IL1B and the tobacco and alcohol consumption for the success or no success of the dental implants. CONCLUSIONS: The alleles 1 and 2 of IL1A gene and the alleles 1 and 2 of IL1B gene were statistically associated with the success or no success of the dental implants. Tobacco habit and alcohol consumption showed no statistically significant association with success or no success of the dental implants.

Th17/Regulatory T cells ratio evolution: A prospective study in a group of healthy pregnant women.

During pregnancy, the maternal immune system is challenged to tolerate a semi-allogenic fetus. A shift toward a tolerogenic profile is essential to ensure a healthy fetal and placental development. One of the most important mechanisms involved in the maternal immune tolerance towards the fetal antigens is expressed in the activity of the regulatory T (Treg) and Th17 cells. The behavior and equilibrium of these two T lymphocyte populations were rarely studied in normal healthy pregnancies through the beginning of gestation to the postpartum period. We conducted a prospective longitudinal observational study where peripheral blood lymphocyte subsets were analyzed in each trimester of pregnancy and postpartum period in a group of healthy pregnant women. Our study observed a consistent reduction in peripheric Treg cell count through all pregnancy while the Th17 cell count remained stable. The Th17/Treg ratio increases significantly throughout pregnancy to the postpartum period. These changes could be justified by the migration of the immunotolerant Treg cells to the maternal decidua and lead to the establishment of a systemic pro-inflammatory profile by the end of pregnancy. This data could explain why systemic syndromes like preeclampsia develop in susceptible women during the second half of pregnancy or why many autoimmune disorders flourish in the first weeks postpartum.

Is leaf fluctuating asymmetry related to plant and leaf size in Miconia albicans, a common Melastomataceae species?

Fluctuating asymmetry, defined as random differences between the two sides of a symmetrical structure, has been often related to development stress in both plants and animals. In plants, leaf fluctuating asymmetry has been related to stresses such as pollution and fire and may also be related to leaf growth and herbivory rates. We assessed whether leaf fluctuating asymmetry is related to plant and leaf size in Miconia albicans (Sw.) Triana (Melastomataceae), a common multi-stem Neotropical shrub, in a Brazilian savanna area. We collected 15 leaves from each of 70 individuals, and measured fluctuating asymmetry as the difference in area between the right and left sides of the leaves using the central vein as reference. To avoid spurious results due to measurement error, the division along the central vein was performed independently by three researchers. We also measured the basal area and height of each stem of the plant individuals. We used linear models to assess the relations between leaf fluctuating asymmetry, plant size and leaf size. No consistent relations were observed between leaf fluctuating asymmetry and plant size, as the analyses performed on the fluctuating asymmetry values obtained by the different researchers showed different results. However, relative fluctuating asymmetry values, obtained by dividing the fluctuating asymmetry by the total leaf area, tended to be smaller in larger leaves. It thus appears that, in the study species, fluctuating asymmetry is related to the developmental conditions faced by the individual leaves and not by the plant as a whole.

Temporal variation in pollen dispersal and breeding structure in a bee-pollinated Neotropical tree.

Variation among flowering seasons in the time of flowering, synchrony and length of flowering, and fluctuations in the abundance of pollinators may cause a variation in pollen dispersal distance. In this study, we analyzed the temporal variation in pollen dispersal and breeding structure in the Neotropical tree species Tabebuia aurea (Bignoniaceae) and evaluated pollen dispersal between a population inside the reserve and a patch of isolated individuals on the edge of the reserve, and tested the hypothesis that isolated individuals are sinking for pollen. All adult trees (260) within a population of 40 ha and 9 isolated individuals on the edge of the reserve were sampled, and from these adults, 21 open-pollinated progeny arrays were analyzed in 2 flowering seasons (309 seeds in 2004 and 328 in 2005). Genetic analyses were based on the polymorphism at 10 microsatellite loci. A high proportion of self-pollination found in both flowering seasons indicated a mixed-mating system. The mean pollen dispersal distance differed significantly between the two flowering seasons (307.78 m in 2004 and 396.26 m in 2005). Maximum pollen dispersal was 2608 m, but most pollination events (65%) occurred at distances <300 m. Our results also showed that isolated individuals are sinking for pollen, with high pollen flow between the population inside the reserve and individuals on the edge. These results are most likely due to the large pollinator species, which can potentially fly long distances, and also due to temporal variation in individual fecundity and contribution to pollen dispersal.