Protocol Design Challenges in the Detection of Awareness in Aware Subjects Using EEG Signals.

Recent studies have evidenced serious difficulties in detecting covert awareness with electroencephalography-based techniques both in unresponsive patients and in healthy control subjects. This work reproduces the protocol design in two recent mental imagery studies with a larger group comprising 20 healthy volunteers. The main goal is assessing if modifications in the signal extraction techniques, training-testing/cross-validation routines, and hypotheses evoked in the statistical analysis, can provide solutions to the serious difficulties documented in the literature. The lack of robustness in the results advises for further search of alternative protocols more suitable for machine learning classification and of better performing signal treatment techniques. Specific recommendations are made using the findings in this work.

Substitute or complement? Defining the relative place of EEG and fMRI in the detection of voluntary brain reactions.

To improve the assessment of awareness in patients with disorders of consciousness, recent protocols using functional Magnetic Resonance Imaging (fMRI) have been developed, and led some specialized coma centers to use this method on a routine basis. Recently, promising results have also been observed with electroencephalography (EEG), a less expensive and widely available technique. However, since the spatiotemporal nature of the recorded signal differs between both EEG and fMRI, the question of whether one method could substitute or should complement the other method is a matter of debate. In this study, we compared the neural processes of two well-known EEG and fMRI mental imagery protocols to define the relative place of each method in the assessment of awareness. A group of 20 healthy volunteers performed both EEG and fMRI command-following and communication tasks. Distinct command following was found with both EEG and fMRI for five subjects, only with fMRI for 12 subjects, and only with EEG for one subject. In the communication task, neither EEG nor fMRI alone gave satisfactory results and no reliable communication could be established in approximately 1/3rd of the participants. If fMRI showed the best performance to detect volitional reactions in mental imagery tasks, our results provide evidence that the use of EEG must not be underestimated since a better detection was found with this method for at least one subject. More than being used as a substitute, EEG should complement fMRI to improve the detection of sign of awareness, and to reduce the risks of misjudgments.

Silage from maize (Zea mays), annual ryegrass (Lolium multiflorum) or their mixture in the dry season feeding of grazing dairy cows in small-scale dairy production systems in the highlands of Mexico.

Small-scale dairy systems based on grazing have dry-season herbage shortages. A repeated 3 x 3 Latin Square experiment evaluated grazing with silage from maize (MS), annual ryegrass (ARG) or a mixture (MIX) with 9 cows with 3 week periods; continuously grazed at 3.6 cows/ha with 3.6 kg DM/day of concentrate. Treatments were 7 kg DM of MS, ARG or a 2 MS:1 ARG mixture. Milk yield (MY), milk composition, live-weight, body condition, silage and concentrate intake were recorded. Herbage DM intake was estimated indirectly. Activity budgets were done for economic analysis. MY on MS (21.5 kg/cow/d) was 0.06 higher than on ARG (P < 0.09) with no differences on MIX. There were no differences for milk fat, milk protein, or body condition score. Live-weight on ARG was higher (P < 0.01) than on MS or MIX. Silage intake was higher (P < 0.01) on ARG and MS than on MIX. Herbage intake was lower (P < 0.05) on MS, compared with MIX and ARG. Total DM intake on ARG was higher than MS (P < 0.01), and MIX in between. MS resulted in 0.12 higher economic returns over ARG which had highest costs. Annual ryegrass may have a place in small-scale systems, but not as silage due to higher costs.

Lesiones vasculares de la extremidad inferior causados por osteocondromas / Vascular lesions in the lower limbs caused by osteochondromas

Introducción. El tumor óseo más frecuente de la población es el osteocondroma (OC). Se puede encontrar deforma esporádica o múltiple, y característicamente afecta a los huesos largos de la extremidad inferior durante la etapade crecimiento. Suele ser asintomático, pero en su crecimiento puede lesionar estructuras vasculares, originando roturay formación de pseudoaneurismas. En la bibliografía médica hasta hoy, la serie más numerosa refiere seis pacientes conlesión vascular por este tumor. Objetivo. Presentar y analizar nuestra experiencia sobre cuatro casos de este tipo de complicacionesvasculares originadas por OC. Pacientes y métodos. En todos se vio afectada la arteria poplítea. Caso 1: varón,16 años, OC múltiple y rotura arterial de cinco días de evolución; caso 2: varón, 9 años, OC esporádico y pseudoaneurismade un mes de evolución; caso 3: varón, 17 años, OC esporádico y pseudoaneurisma gigante de mes y mediode evolución; caso 4: mujer, 19 años, OC múltiple y pseudoaneurisma de once meses de evolución. La reconstrucción arterialfue con parche venoso en tres casos y sutura directa en uno. Resultados. No hubo recidivas de los OC en los casos1 y 2, de prolongado seguimiento. El análisis anatomopatológico confirmó la benignidad en todos. Curso postoperatoriofavorable y alta hospitalaria precoz. Conclusión. Es necesario descartar este cuadro ante dolor en extremidades inferioresen adolescentes debido a la frecuencia de estos tumores, especialmente si se conoce la existencia previa de OC. Es importanteel estudio de imagen con reconstrucción arterial antes de la cirugía. Es necesario resecar de modo preventivolos OC de crecimiento hacia trayectos vasculares, aun siendo asintomáticos

Introduction. The most common bone tumour is osteochondroma (OC). It may be found in both sporadicsolitary or multiple forms, and characteristically affects the long bones of the lower limbs while the individual is stillgrowing. It is usually asymptomatic but as it grows it may injure vascular structures, giving rise to ruptures and theformation of pseudoaneurysms. In the medical literature to date, the most numerous series consisted of six patients withvascular lesions due to this kind of tumour. Aim. To report and analyse our experience on four cases of this sort ofvascular complications produced by OC. Patients and methods. In all cases the popliteal artery was involved. Case 1:male, 16 years old, multiple OC and a five-day history of arterial rupture; case 2: male, 9 years old, sporadic OC and aone-month history of pseudoaneurysm; case 3: male, 17 years old, sporadic OC and a one-month history of giantpseudoaneurysm; case 4: female, 19 years old, sporadic OC and an 11-months’ history of pseudoaneurysm. Arterialreconstruction was performed with a vein patch in three cases and direct suturing in one case. Results. There were norecurrences of OC in cases 1 and 2, which were subject to long follow-ups. Pathological analysis confirmed the tumourswere benign in all cases. Post-operative progress was favourable and patients were soon discharged from hospital.Conclusions. This condition needs to be ruled out when dealing with pain in the lower limbs in teenagers, due to thefrequency of these tumours, especially if OC is known to have existed previously. An imaging study is important witharterial reconstruction before surgery. OCs growing towards vascular pathways must be excised as a preventivemeasure, even though they are asymptomatic

[Heart arrest in cemented hip arthroplasty]. / Paro cardíaco en artroplastia de cadera cementada.

Hip arthroplasty is a common surgical intervention in our hospital practice, involving high perioperative risk related to patients age and multiple concomitant diseases. Hemodynamic complications described vary from slight hypotension during surgery to heart failure and sudden death, particularly if the operation involves a cemented femoral component. Because of the type of patients undergoing such operations (elderly patients, with osteoporosis and scarce cardiopulmonary reserve), the unclear origin of complications and the lack of consensus on what constitutes adequate monitoring during surgery, hip arthroplasty is problematic for the specialists involved. We report on five deaths during cemented hip arthroplasty; after reviewing the case history and autopsy report of one, we believe the events leading to death were triggered by massive pulmonary embolism.

A case of cardiac hydatidosis.

We present the case of a female patient with a diagnosis of hydatidosis located in the heart. Although echinococcosis is endemic to our country, very few cases of cardiac hydatidosis are normally reported. In our patient, the hydatid cyst was located in the septum and in the right ventricular cavity; it presented other unusual features, such as the fact that it was located exclusively in the heart, that it first manifested as anaphylactic shock of unknown origin and that it required immediate surgical treatment because of severe haemodynamic compromise.

Specificity-determining regions of a lepidopteran-specific insecticidal protein produced by Bacillus thuringiensis.

The lepidopteran-specific, insecticidal crystal proteins of Bacillus thuringiensis vary in toxicity to different species of lepidopteran larvae. We report studies of CryIA(a) and CryIA(c), two related proteins that have different degrees of toxicity to Heliothis virescens yet very similar degrees of toxicity to Manduca sexta. The amino acid differences between these proteins are located primarily between residues 280 and 722. We have constructed a series of chimeric proteins and determined their toxicities to both insects. The most significant findings arise from the replacement of three segments of the cryIA(c) gene with homologous portions of the cryIA(a) gene: codons 332-428, 429-447, and 448-722. Each of these segments contributed substantially and largely additively toward efficacy for H. virescens. However, replacement of the 429-447 segment of cryIA(c) gene with the cryIA(a) sequence resulted in a 27-50-fold reduction in toxicity toward M. sexta whereas the reduction in toxicity to H. virescens was only 3-4-fold. Subdivision of the 429-447 segment and replacements involving residues within this segment reduced toxicity to M. sexta by 5- to more than 2000-fold whereas toxicity to H. virescens was only reduced 3-10-fold. These observations indicate that: 1) different but overlapping regions of the cryIA(c) gene determine specificity to each of the two test insects; 2) some of the examined gene segments interact in determining specificity; and 3) different sequences in the cryIA(a) and cryIA(c) genes are required for maximal toxicity to M. sexta.

The cell-free synthesis of cytochrome c by a microsomal fraction from rat liver.

Conditions were investigated for demonstrating the synthesis in vitro of the complete molecule of cytochrome c by isolated liver microsomal systems from partially hepatectomized rats. It was first found that in vivo the early labelled cytochrome c associated with the microsomal fraction required, by comparison with the mitochondrial pool, more drastic conditions of extraction and its binding was less affected by freezing and thawing of the subcellular particles. The procedure of extraction and purification of cytochrome c had to be modified accordingly, to assure the recovery of the recently synthesized molecule. Several subcellular fractions were isolated from regenerating liver with a homogenization medium containing either 5 or 10mm-Mg(2+) and most of them were active in the synthesis of the cytochrome c apoprotein. The microsomal fraction, in the presence of either cell sap or pH5.0 fraction, was also able to incorporate [(59)Fe]haemin, delta-amino[(3)H]laevulic acid and (55)Fe into the prosthetic group of cytochrome c. These experiments confirm firmly the conclusions of our previous results obtained in vivo showing that both the apoprotein and the haem moieties are made and linked together on cytoplasmic ribosomes and only then is the complete molecule transferred to the mitochondria.