Strain Echocardiography to Predict Postoperative Atrial Fibrillation

Postoperative atrial fibrillation (POAF) complicates 15% to 40% of cardiovascular surgeries. Its incidence progressively increases with aging, reaching 50% in octogenarians. This arrhythmia is usually transient but it increases the risk of embolic stroke, prolonged hospital stay, and cardiovascular mortality. Though many pathophysiological mechanisms are known, POAF prediction is still a hot topic of discussion. Doppler echocardiogram and, lately, strain echocardiography have shown significant capacity to predict POAF. Alterations in oxidative stress, calcium handling, mitochondrial dysfunction, inflammation, fibrosis, and tissue aging are among the mechanisms that predispose patients to the perfect “atrial storm”. Manifestations of these mechanisms have been related to enlarged atria and impaired function, which can be detected prior to surgery. Specific alterations in the atrial reservoir and pump function, as well as atrial dyssynchrony determined by echocardiographic atrial strain, can predict POAF and help to shed light on which patients could benefit from preventive therapy.

Computer-aided prediction of polyp histology on white light colonoscopy using surface pattern analysis

BACKGROUND

This study aimed to evaluate a new computational histology prediction system based on colorectal polyp textural surface patterns using high definition white light images.

METHODS

Textural elements (textons) were characterized according to their contrast with respect to the surface, shape, and number of bifurcations, assuming that dysplastic polyps are associated with highly contrasted, large tubular patterns with some degree of bifurcation. Computer-aided diagnosis (CAD) was compared with pathological diagnosis and the diagnosis made by endoscopists using Kudo and Narrow-Band Imaging International Colorectal Endoscopic classifications.

RESULTS

Images of 225 polyps were evaluated (142 dysplastic and 83 nondysplastic). The CAD system correctly classified 205 polyps (91.1 %): 131/142 dysplastic (92.3 %) and 74/83 (89.2 %) nondysplastic. For the subgroup of 100 diminutive polyps (≤ 5 mm), CAD correctly classified 87 polyps (87.0 %): 43/50 (86.0 %) dysplastic and 44/50 (88.0 %) nondysplastic. There were no statistically significant differences in polyp histology prediction between the CAD system and endoscopist assessment.

CONCLUSION

A computer vision system based on the characterization of the polyp surface in white light accurately predicted colorectal polyp histology.

Weeds and ground-dwelling predators' response to two different weed management systems in glyphosate-tolerant cotton: A farm-scale study

The use of glyphosate, as a post-emergence broad-spectrum herbicide in genetically modified glyphosate-tolerant (GT) cotton, supposes a big change in weed management programs with respect to a conventional regime. Thus, alterations in arable flora and arthropod fauna must be considered when evaluating their potential impacts. A 3-year farm-scale study was conducted in a 2-ha GT cotton crop, in southern Spain, to compare the effects of conventional and glyphosate herbicide regimes on weed abundance and diversity and their consequences for ground-dwelling predators. Surveys reveal that weed density was relatively low within all treatments with a few dominant species, with significantly higher weed densities and modifications of the floristic composition in glyphosate-treated plots that led to an increase in the abundance of Portulaca oleracea and to a reduction in plant diversity. The activity-density of the main predatory arthropod taxa (spiders, ground beetles, rove beetles and earwigs) varied among years, but no significant differences were obtained between conventional and glyphosate herbicide regimes. However, significant differences between treatments were obtained for ground beetles species richness and diversity, being higher under the glyphosate herbicide regime, and a positive correlation with weed density could be established for both parameters. The implications of these findings to weed control in GT cotton are discussed.

Behavioral evidence of hunting and foraging techniques by a top predator suggests the importance of scavenging for preadults

Scavenging may be a regular feeding behavior for some facultative raptor species occupying low quality habitats and/or with little experience in hunting techniques. However, its importance has been largely underestimated due to methodological limitations in identifying the real proportion in the diet. Here, through direct observations, we assessed the hunting and foraging success of the threatened Spanish imperial eagle Aquila adalberti determining the influence of age, sex, breeding status, habitat quality, prey type, and landscape characteristics. From 465 observations, Spanish imperial eagles used hunting in flight (42%), scavenging (30%), hunting from a perch (16%) and kleptoparasitism (12%). Our model suggests that Prey size and Prey type best explain hunting success, followed by Landscape and Sex. Our findings suggest that Spanish imperial eagles increase hunting success with age, with scavenging and kleptoparasitism regularly used as juveniles. The absence of relationships with any of the variables considered suggests that kleptoparasitism is an opportunistic behavior used sporadically. Scavenging is also independent of habitat quality and landscape characteristics. Accordingly, low prey density is not a driver of carrion use for preadult individuals, suggesting that a lack of hunting ability obliges this age‐class to use this alternative feeding technique regularly. As a result, the threatened Spanish imperial eagle population is also prone to mortality related to the illegal use of poison baits and, potentially, veterinary drugs (i.e., diclofenac).

Exploring the clinical potential of an automatic colonic polyp detection method based on the creation of energy maps

BACKGROUND AND AIMS

Polyp miss-rate is a drawback of colonoscopy that increases significantly for small polyps. We explored the efficacy of an automatic computer-vision method for polyp detection.

METHODS

Our method relies on a model that defines polyp boundaries as valleys of image intensity. Valley information is integrated into energy maps that represent the likelihood of the presence of a polyp.

RESULTS

In 24 videos containing polyps from routine colonoscopies, all polyps were detected in at least one frame. The mean of the maximum values on the energy map was higher for frames with polyps than without (P < 0.001). Performance improved in high quality frames (AUC = 0.79 [95 %CI 0.70 - 0.87] vs. 0.75 [95 %CI 0.66 - 0.83]). With 3.75 set as the maximum threshold value, sensitivity and specificity for the detection of polyps were 70.4 % (95 %CI 60.3 % - 80.8 %) and 72.4 % (95 %CI 61.6 % - 84.6 %), respectively.

CONCLUSION

Energy maps performed well for colonic polyp detection, indicating their potential applicability in clinical practice.

Puberty in the corpus callosum

Adolescence is an important period for brain development. White matter growth is influenced by sex hormones such as testosterone, and the corpus callosum-the largest white matter structure in the human brain-may change structurally during the hormone-laden period of adolescence. Little is known about puberty's relationship to structural brain development, even though pubertal stage may better predict cognitive and behavioral maturity than chronological age. We therefore aimed to establish the presence and direction of pubertal effects on callosal anatomy. For this purpose, we applied advanced surface-based mesh-modeling to map correlations between callosal thickness and pubertal stage in a large and well-matched sample of 124 children and adolescents (62 female and 62 male) aged 5-18years from a normative database. When linking callosal anatomy to pubertal status, only positive correlations reached statistical significance, indicating that callosal growth advances with puberty. In tests of differences in callosal anatomy at different stages of puberty, callosal growth was concentrated in different locations depending on the pubertal stage. Changing levels of circulating sex hormones during different phases of puberty likely contributed to the observed effects, and further research is clearly needed. Direct quantification of sex hormone levels and regional fiber connectivity-ideally using fiber tractography-will reveal whether hormones are the main drivers of callosal change during puberty. These callosal findings may lead to hypotheses regarding cortical changes during puberty, which may promote or result from changes in inter-hemispheric connectivity.

Extremotolerance and resistance of lichens: comparative studies on five species used in astrobiological research II. Secondary lichen compounds

Lichens, which are symbioses of a fungus and one or two photoautotrophs, frequently tolerate extreme environmental conditions. This makes them valuable model systems in astrobiological research to fathom the limits and limitations of eukaryotic symbioses. Various studies demonstrated the high resistance of selected extremotolerant lichens towards extreme, non-terrestrial abiotic factors including space exposure, hypervelocity impact simulations as well as space and Martian parameter simulations. This study focusses on the diverse set of secondary lichen compounds (SLCs) that act as photo- and UVR-protective substances. Five lichen species used in present-day astrobiological research were compared: Buellia frigida, Circinaria gyrosa, Rhizocarpon geographicum, Xanthoria elegans, and Pleopsidium chlorophanum. Detailed investigation of secondary substances including photosynthetic pigments was performed for whole lichen thalli but also for axenically cultivated mycobionts and photobionts by methods of UV/VIS-spectrophotometry and two types of high performance liquid chromatography (HPLC). Additionally, a set of chemical tests is presented to confirm the formation of melanic compounds in lichen and mycobiont samples. All investigated lichens reveal various sets of SLCs, except C. gyrosa where only melanin was putatively identified. Such studies will help to assess the contribution of SLCs on lichen extremotolerance, to understand the adaptation of lichens to prevalent abiotic stressors of the respective habitat, and to form a basis for interpreting recent and future astrobiological experiments. As most of the identified SLCs demonstrated a high capacity in absorbing UVR, they may also explain the high resistance of lichens towards non-terrestrial UVR.

Extremotolerance and resistance of lichens: comparative studies on five species used in astrobiological research I. Morphological and anatomical characteristics

Lichens are symbioses of two organisms, a fungal mycobiont and a photoautotrophic photobiont. In nature, many lichens tolerate extreme environmental conditions and thus became valuable models in astrobiological research to fathom biological resistance towards non-terrestrial conditions; including space exposure, hypervelocity impact simulations as well as space and Martian parameter simulations. All studies demonstrated the high resistance towards non-terrestrial abiotic factors of selected extremotolerant lichens. Besides other adaptations, this study focuses on the morphological and anatomical traits by comparing five lichen species-Circinaria gyrosa, Rhizocarpon geographicum, Xanthoria elegans, Buellia frigida, Pleopsidium chlorophanum-used in present-day astrobiological research. Detailed investigation of thallus organization by microscopy methods allows to study the effect of morphology on lichen resistance and forms a basis for interpreting data of recent and future experiments. All investigated lichens reveal a common heteromerous thallus structure but diverging sets of morphological-anatomical traits, as intra-/extra-thalline mucilage matrices, cortices, algal arrangements, and hyphal strands. In B. frigida, R. geographicum, and X. elegans the combination of pigmented cortex, algal arrangement, and mucilage seems to enhance resistance, while subcortex and algal clustering seem to be crucial in C. gyrosa, as well as pigmented cortices and basal thallus protrusions in P. chlorophanum. Thus, generalizations on morphologically conferred resistance have to be avoided. Such differences might reflect the diverging evolutionary histories and are advantageous by adapting lichens to prevalent abiotic stressors. The peculiar lichen morphology demonstrates its remarkable stake in resisting extreme terrestrial conditions and may explain the high resistance of lichens found in astrobiological research.

Limits of laparoscopic radical nephrectomy

OBJECTIVES

Laparoscopic radical nephrectomy is considered to be the technique of choice in the management of stage T1 and T2 renal cancer, through increased expertise in this alternative type of surgery has served to expand its indications. In any case, these procedures have a series of limitations which are tied to the intrinsic characteristics of laparoscopic surgery, and associated with patient and tumor characteristics, and surgeon's expertise.

METHODS

We performed a bibliographic review through Pub Med database.

RESULTS

The present study discusses the different indications and establishes the current limits of laparoscopic surgery applied to the management of renal tumors (including T3 and T4). Its role in cell reducing therapy for metastatic disease, and the available methods to reduce tumor implantation in the surgical ports are also commented.

CONCLUSIONS

Radical laparoscopic surgery is the technique of choice for the treatment of renal tumors in stage T1 and T2. There are not significant differences among the different approaches, and it has lower incision-related morbidity compared to traditional surgery, a shorter period of convalescence and the same oncological efficacy.

Effects of sprout cutting plus systemic herbicide application on the initial growth of giant reed

Chlorophyll fluorescence analysis (CFA) has been successfully used to rapidly determine the responses of different plants to herbicides. It has not, however, been used to test the effect of these products on invasive riparian species. This paper reports the use of CFA to determine photosynthetic activity in Arundo donax, an invasive reed causing serious problems in Mediterranean riparian habitats, in response to systemic herbicide application following cutting. Growth was measured in terms of new sprout relative height and sprout and rhizome relative biomass. CFA showed glyphosate, from half the on-label dose of 5 L ai.ha(-1)upwards, to have a significant effect (100% reduction) on photosynthetic activity at 21 days after treatment (DAT), while profoxydim, from half the on-label dose of 0.375 L ai.ha(-1)upwards, caused a 70% reduction soon after application, although these plants later recovered. Azimsulfuron, cyhalofop-butyl and penoxsulam had no significant effect on photosynthetic activity at any dose. At 60 DAT, glyphosate (from half the on-label dose of 5 L ai.ha(-1)upwards) was associated with a 90% reduction in sprout height, while profoxydim (from half the on-label dose of 0.375 L ai.ha(-1)upwards) caused a 50% reduction. No dose (0-2x the on-label dose) of azimsulfuron, penoxsulam or cyhalofop-butyl was associated with any significant growth reduction at 60 DAT. The results show that CFA can be used to successfully measure the response of these invasive plants to herbicides, and that glyphosate, and possibly profoxydim, might be used to control Arundo donax after initial cutting.

Targeted massively parallel sequencing provides comprehensive genetic diagnosis for patients with disorders of sex development

Disorders of sex development (DSD) are rare disorders in which there is discordance between chromosomal, gonadal, and phenotypic sex. Only a minority of patients clinically diagnosed with DSD obtains a molecular diagnosis, leaving a large gap in our understanding of the prevalence, management, and outcomes in affected patients. We created a novel DSD-genetic diagnostic tool, in which sex development genes are captured using RNA probes and undergo massively parallel sequencing. In the pilot group of 14 patients, we determined sex chromosome dosage, copy number variation, and gene mutations. In the patients with a known genetic diagnosis (obtained either on a clinical or research basis), this test identified the molecular cause in 100% (7/7) of patients. In patients in whom no molecular diagnosis had been made, this tool identified a genetic diagnosis in two of seven patients. Targeted sequencing of genes representing a specific spectrum of disorders can result in a higher rate of genetic diagnoses than current diagnostic approaches. Our DSD diagnostic tool provides for first time, in a single blood test, a comprehensive genetic diagnosis in patients presenting with a wide range of urogenital anomalies.

B chromosomes: the troubles of integration

Starting with a spontaneous B-A centric fusion found in a natural population of the grasshopper Eyprepocnemis plorans, we have obtained different strains carrying the rearrangement in various conditions and doses. Using this material, we have analyzed the meiotic behavior of the translocated chromosome in living cultured spermatocytes, simulating the successive steps of a hypothetical process of integration of a B chromosome into the standard genome via B-A centric fusion. Remarkably, the behavior of fusion heterozygotes, the initial step of the integration process, is much more regular than that of any other configuration, including homozygotes. The reasons for the failure of B chromosome integration into the normal complement by translocation are discussed.

[Acute myocardial infarction in patients under 45 years]

INTRODUCTION AND OBJECTIVE

To evaluate the differential features of acute myocardial infarction in patients younger than 45 years old compared to older patients.

PATIENTS AND METHODS

From 1995 to 1999, delays in the assistance, evaluation, and therapeutic strategies as well as complications in patients hospitalized with a diagnosis of acute myocardial infarction, have been registered in the intensive care units of the 17 hospitals participating in the PRIMVAC Register.

RESULTS

During the study, 10,213 patients were registered, 6.8% younger than 45 years old (691 patients). Young patients show a greater prevalence of cigarette smoking (80.9 vs 34.1%; p < 0.0001) and hypercholesterolemia (39.9 vs 28.6%; p < 0.0001), whereas arterial hypertension, diabetes, and history of coronary disease were significantly more frequent in the older group. This subgroup reached the healthcare system at an earlier stage (120 vs 160 min; p < 0.0001). Thrombolysis was performed in 59.9% of patients younger than 45 years and in 45.9% of patients older than 45 years. Young patients were more frequently given aspirin (94.5%), heparin (70.6%), and beta-blocker drugs (38.4%), whereas patients older than 45 years were given a higher percentage of ACEI, digoxin, and inotropic drugs. Younger patients had a better prognosis and a lower mortality rate (3.5 vs 14%; p < 0.00001).

CONCLUSIONS

Acute myocardial infarction in patients younger than 45 years had different clinical features and responded to different therapeutic and diagnostic approaches than acute myocardial infarction in patients over 45 years, as well as a better short-term prognosis.

Prevalence of acute intermittent porphyria in a Mexican psychiatric population

BACKGROUND

Acute intermittent porphyria is a hereditary error of porphyrin metabolism in which the main metabolic defect is caused by a decrease in porphobilinogen deaminase activity. Previous work has demonstrated a higher prevalence of acute intermittent porphyria in the psychiatric patient population than in the general population. The goal of this study was evaluate 300 psychiatric patients and 150 control subjects to detect acute intermittent porphyria by measurement of porphobilinogen (PBG) deaminase activity in blood.

METHODS

Screening for porphobilinogen deaminase activity was carried out by fluorometric measurement of porphyrins synthesized during 1 h in blood and the measurement of delta-aminolevulinic acid and porphobilinogen in urine.

RESULTS

We found two psychiatric patients, one male and one female, with decreased porphobilinogen deaminase activity. When the families of these patients were studied, one brother was found to have an abnormality. Among controls, a woman was found to have the abnormality and her father was found to have typical features of the disease.

CONCLUSIONS

These results indicate a prevalence of porphyria in Mexican psychiatric patients similar to controls, and that measurement of PBG deaminase activity is a good tool for defining acute intermittent porphyria carriers.

[Light microscopy study of rat testicle after vasectomy]

Bilateral scrotal vasectomy with double ligature and deferent duct section was performed in 55 male Wistar rats randomly assigned to three groups: control, simulated and experimental, which were studied after 1, 2, 6, 10 and 14 weeks post-vasectomy. At 6 weeks after vasectomy testicular atrophy, destructuration of epithelium germination, absence of spermatozoa, thickening and folding of tubular membrane were observed as well as a large dilation of interstitial space, features that are all increased after 10 and 14 weeks.

Endocrine evaluation in a patient with MURCS association and ovarian agenesis

A new case of Mullerian duct aplasia, renal aplasia, and cervicothoracic somite dysplasia (MURCS association) in a 16-yr-old female patient is reported. In addition, agenesis of the right ovary plus hypoplasia of the right craniofacial bones were also present. Dynamic tests of anterior pituitary reserve (LH-RH, TRH and hypoglycemia) showed normal responsiveness of this gland in terms of LH, FSH, TSH, prolactin and growth hormone secretion, whilst a subnormal plasma cortisol response to hypoglycemia and exogenous ACTH (in the presence of unilateral adrenal agenesis) was found. Functional integrity of the hypothalamic-pituitary-ovarian axis was also documented. The presence of two additional and previously unreported congenital anomalies in this patient with MURCS association underlines the wide spectrum of the syndrome.