Osteoporosis y cirugía de raquis: estrategias de tratamiento médico / Osteoporosis and spinal surgery: strategies for medical and surgical treatment

La prevalencia de osteoporosis en pacientes sometidos a cirugía de raquis se ha estimado en el 50% de las mujeres de más de 50 años, cifra superior a la de la población en general ajustada por edad. Consecuentemente, muchos autores recomiendan la evaluación sistemática y el tratamiento oportuno de la osteoporosis en la mayoría de pacientes que se van a someter a una cirugía de artrodesis. La disminución de la densidad mineral ósea (DMO) es el principal factor de riesgo independiente relacionado con el fracaso de la instrumentación en las cirugías de fusión lumbar. Las complicaciones derivadas de la cirugía de fusión vertebral son más frecuentes en pacientes mayores de 65 años y osteoporóticos. Las complicaciones tempranas más frecuentes son el pullout o arrancamiento de los tornillos pediculares, la fractura pedicular y la fractura por mecanismo de compresión en el segmento vertebral adyacente. Después de los 3 meses, las complicaciones más frecuentes son la pseudoartrosis, la fractura o la movilización de las barras, la subsidencia de cajas intersomáticas vertebral y la cifosis de la unión proximal. Existen algunos ensayos clínicos de cirugía de artrodesis de columna con tratamiento perioperatorio con alendronato, ácido zoledrónico, o teriparatida que han demostrado ser efectivos en la mejoría clínica y el incremento de las tasas de fusión. Existen diversas modificaciones en el arsenal quirúrgico que pueden mejorar las tasas de fusión y disminuir las complicaciones quirúrgicas, a destacar la artrodesis con tornillos pediculares cementados y tornillos expansibles. Finalmente existen ensayos clínicos aleatorizados que han demostrado que los tratamientos de refuerzo vertebral en fracturas vertebrales osteoporóticas son claramente beneficiosos a corto y a largo plazo

The prevalence of osteoporosis in patients undergoing spinal surgery is estimated at 50% in women over 50 years, a higher figure than in the general population adjusted for age. Consequently, many authors recommend the systematic assessment and timely treatment of osteoporosis in most patients who are going to undergo arthrodesis. The decrease in bone mineral density (BMD) is the main factor in independent risk related to the failure of the instrumentation in spinal fusion surgeries. Complications arising from spinal fusion are more frequent in osteoporotic patients over 65. The most frequent early complications are pullout or tearing pedicular screws, pedicular fracture and fracture by compression in the adjacent vertebral segment. After 3 months, the most frequent complications are pseudoarthrosis, fracture or mobilization of the bars, subsidence of vertebral intersomatic boxes and the kyphosis of the proximal joint. There are some clinical trials of spinal arthrodesis surgery with perioperative treatment with alendronate, zoledronic acid, or teriparatide that have been shown to be effective in clinical improvement and increase in fusion rates. Several modifications in the surgical arsenal may improve fusion rates and decrease surgical complications. Arthrodesis has been highlighted with cemented and expandable pedicle screws. Finally, randomized clinical trials have shown that vertebral reinforcement treatments in osteoporotic vertebral fractures are beneficial in the short and long term

Effect of electrical stunning frequency and current waveform in poultry welfare and meat quality.

This study aimed to evaluate the effects of different stunning frequencies and electrical current waveforms on chicken welfare and meat quality. Two-hundred-thirty-two Cobb broilers, 48 d of age and 2.76 ± 0.47 live-weight, were randomly assigned into 4 stunning treatments - 2 frequencies (300 Hz and 650 Hz) and 2 current waveforms (direct current [DC] and alternating current [AC]). Broilers were electrically stunned in a water bath in a commercial slaughterhouse (70 V, 100 mA). The electronarcosis and stunning efficiency were confirmed by assessment of visual parameters (absence of rhythmic breathing, ocular reflex, and coordinated wing flapping) and blood parameters (lactate, glucose, creatine kinase, sodium, and potassium), which were measured after bleeding. The incidence of traumas and injuries was assessed after plucking. Meat quality analysis was performed in Pectoralis major (PM), with determinations of pH, breast yield (PMY), water holding capacity (WHC), water absorption capacity (WAC), thawing loss (DL), cooking loss (CL), shear force (SF), and instrumental color (a*, b*, L*, C*, and h). The interaction between waveform and frequency was significant (P < 0.05) only for lactate, sodium, and lightness (L*). Lactate and sodium levels decreased at 300 Hz-DC. Meat lightness increased at 300 Hz-DC. The individual effect of frequency was significant for glucose, creatine kinase, potassium, WHC, PMY, b*, C*, and h. Regarding waveform, AC decreased plasma glucose and DC decreased creatine kinase and WAC. In general, stunning frequency exerts greater influence than waveform on the welfare and meat quality parameters of broilers. The use of frequency at 650 Hz proved to render animals efficiently unconscious and to promote greater meat quality.

Estimation of mercury background values in sediment and biota of the Bijagós archipelago, Guinea-Bissau.

This work evaluates the mercury (Hg) contamination status (sediments and biota) of the Bijagós archipelago, off the coast of Guinea-Bissau. Sediments exhibited very low concentrations (<1-12ngg(-1)), pointing to negligible sources of anthropogenic Hg in the region. Nevertheless, Hg is well correlated to the fine fraction, aluminium, and loss on ignition, indicating the effect of grain size and organic matter content on the presence of Hg in sediments. Mercury in the bivalves Tagelus adansoni and Senilia senilis did not vary considerably among sites, ranging within narrow intervals (0.09-0.12 and 0.12-0.14µgg(-1) (dry weight), respectively). Divergent substrate preferences/feeding tactics may justify slight differences between species. The value 11ngg(-1) is proposed as the sediment background concentration for this West-African coastal region, and concentrations within the interval 8-10ngg(-1) (wet weight) may be considered as reference range for S. senilis and T. adansoni in future monitoring studies.

A Pragmatic Bayesian Perspective on Correlation Analysis : The exoplanetary gravity - stellar activity case.

We apply the Bayesian framework to assess the presence of a correlation between two quantities. To do so, we estimate the probability distribution of the parameter of interest, ρ, characterizing the strength of the correlation. We provide an implementation of these ideas and concepts using python programming language and the pyMC module in a very short (∼ 130 lines of code, heavily commented) and user-friendly program. We used this tool to assess the presence and properties of the correlation between planetary surface gravity and stellar activity level as measured by the log([Formula: see text]) indicator. The results of the Bayesian analysis are qualitatively similar to those obtained via p-value analysis, and support the presence of a correlation in the data. The results are more robust in their derivation and more informative, revealing interesting features such as asymmetric posterior distributions or markedly different credible intervals, and allowing for a deeper exploration. We encourage the reader interested in this kind of problem to apply our code to his/her own scientific problems. The full understanding of what the Bayesian framework is can only be gained through the insight that comes by handling priors, assessing the convergence of Monte Carlo runs, and a multitude of other practical problems. We hope to contribute so that Bayesian analysis becomes a tool in the toolkit of researchers, and they understand by experience its advantages and limitations.

Reflected Light from Giant Planets in Habitable Zones: Tapping into the Power of the Cross-Correlation Function.

The direct detection of reflected light from exoplanets is an excellent probe for the characterization of their atmospheres. The greatest challenge for this task is the low planet-to-star flux ratio, which even in the most favourable case is of the order of 10-4 in the optical. This ratio decreases even more for planets in their host's habitable zone, typically lower than 10-7. To reach the signal-to-noise level required for such detections, we propose to unleash the power of the Cross Correlation Function in combination with the collecting power of next generation observing facilities. The technique we propose has already yielded positive results by detecting the reflected spectral signature of 51 Pegasi b (see Martins et al. 2015). In this work, we attempted to infer the number of hours required for the detection of several planets in their host's habitable zone using the aforementioned technique from theoretical EELT observations. Our results show that for 5 of the selected planets it should be possible to directly recover their reflected spectral signature.

Core-shell magnetite-silica dithiocarbamate-derivatised particles achieve the Water Framework Directive quality criteria for mercury in surface waters.

The sorption capacity of nanoporous titanosilicate Engelhard titanosilicate number 4 (ETS-4) and silica-coated magnetite particles derivatised with dithiocarbamate groups towards Hg(II) was evaluated and compared in spiked ultra-pure and spiked surface-river water, for different batch factors. In the former, and using a batch factor of 100 m(3)/kg and an initial Hg(II) concentrations matching the maximum allowed concentration in an effluent discharge, both materials achieve Hg(II) uptake efficiencies in excess of 99 % and a residual metal concentration lower than the guideline value for drinking water quality. For the surface-river water and the same initial concentration, the Hg(II) uptake efficiency of magnetite particles is outstanding, achieving the quality criteria established by the Water Framework Directive (concerning Hg concentration in surface waters) using a batch factor of 50 m(3)/kg, while the efficiency of ETS-4 is significantly inferior. The dissimilar sorbents' Hg(II) removal efficiency is attributed to different uptake mechanisms. This study also highlights the importance of assessing the effective capacity of the sorbents under realistic conditions in order to achieve trustable results.

Removal of mercury (II) by dithiocarbamate surface functionalized magnetite particles: application to synthetic and natural spiked waters.

In order to take advantage of the high affinity between mercury and sulphur, magnetite (Fe(3)O(4)) particles functionalized with dithiocarbamate groups (CS(2)(-)), were synthesized to be used as a new type of sorbent to remove Hg (II) from synthetic and natural spiked waters. The effectiveness of this type of sorbent was studied, and its potential as cleanup agent for contaminated waters was assessed. Batch stirred tank experiments were carried out by contacting a volume of solution with known amounts of functionalized Fe(3)O(4) particles, in order to study the effect of sorbent dose, salinity, and the kinetics and the equilibrium of this unit operation. A complete Hg (II) removal (ca. 99.8%) was attained with 6 mg/L of magnetic particles for an initial metal concentration of 50 µg/L. It was confirmed that highly complex matrices, such as seawater (ca. 99%) and river water (ca. 97%), do not affect the removal capacity of the functionalized magnetic particles. Concerning isotherms, no significant differences were observed between two- and three-parameter models (P = 0.05%); however, Sips isotherm provided the lowest values of SS and S(x/y), predicting a maximum sorption capacity of 206 mg/g, in the range of experimental conditions under study. The solid loadings measured in this essay surmount the majority of the values found in literature for other type of sorbents.

Helicobacter pylori genotypes are associated with clinical outcome in Portuguese patients and show a high prevalence of infections with multiple strains.

BACKGROUND: Clinical outcome of Helicobacter pylori infection is associated with virulence-associated bacterial genotypes. This study assessed the relationships between vacA, cagA and iceA genotypes and gastric diseases in Portuguese patients. METHODS: A total of 319 patients were endoscoped and gastric biopsy specimens were studied by PCR and reverse hybridization (LiPA). RESULTS: vacA genotypes s1/m1, s1/m2 and s2/m2 were observed in 53%, 14.5% and 32.5% of the cases, respectively. The majority (93.4%) of the s1 cases were s1b and 6.6% were s1a. Multiple vacA genotypes were found in 37.3% of the cases. Gastric ulcer and gastric carcinoma were associated with the presence of vacA s1 (P = 0.008 and P < 0.001, respectively) and vacA m1 genotypes (P = 0.007 and P < 0.001, respectively). Duodenal ulcers were associated with vacA s1 (P < 0.001) but not with the vacA m genotype (P = 0.221). cagA was present in 71.2% of the cases and was associated with duodenal ulcer (P < 0.001), gastric ulcer (P = 0.009) and gastric carcinoma (P < 0.001). iceA1 was found in 27.3% and iceA2 in 32.3% of the cases. In 36.7% of the isolates both iceA alleles were found, and 3.8% were negative for iceA. The iceA genotype was not associated with clinical outcome. CONCLUSIONS: vacA s1 and cagA+ H. pylori strains are associated with duodenal ulcer, gastric ulcer or gastric carcinoma. vacA m1 is associated with gastric ulcer or carcinoma but not with duodenal ulcer. Infection with multiple H. pylori strains is remarkably high in Portugal and is more frequent in duodenal ulcer patients.

Helicobacter pylori genotypes may determine gastric histopathology.

The outcome of Helicobacter pylori infection has been associated with specific virulence-associated bacterial genotypes. The present study aimed to investigate the gastric histopathology in Portuguese and Colombian patients infected with H. pylori and to assess its relationship with bacterial virulence-associated vacA, cagA, and iceA genotypes. A total of 370 patients from Portugal (n = 192) and Colombia (n = 178) were studied. Corpus and antrum biopsy specimens were collected from each individual. Histopathological features were recorded and graded according to the updated Sydney system. H. pylori vacA, cagA, and iceA genes were directly genotyped in the gastric biopsy specimens by polymerase chain reaction and reverse hybridization. Despite the significant differences between the Portuguese and Colombian patient groups, highly similar results were observed with respect to the relation between H. pylori genotypes and histopathology. H. pylori vacA s1, vacA m1, cagA+ genotypes were significantly associated with a higher H. pylori density, higher degrees of lymphocytic and neutrophilic infiltrates, atrophy, the type of intestinal metaplasia, and presence of epithelial damage. The iceA1 genotype was only associated with epithelial damage in Portuguese patients. These findings show that distinct H. pylori genotypes are strongly associated with histopathological findings in the stomach, confirming their relevance for the development of H. pylori-associated gastric pathology.

Lítio, Carbamazepina e Acido Valpróico: eficácia na fase de manutençäo / Lithium, carbamazepine and valproate: efficacy in the prophylaxis of bipolar disorder

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