Influence of introducing a maneuverable vacuum extractor cup on maternal hospital stay after instrumental birth. Retrospective cohort study / Repercusión de la introducción de la ventosa obstétrica maniobrable en un centro hospitalario sobre la estancia materna tras parto instrumental. Estudio de cohortes retrospectivo

Objectives: The aim of our study is to evaluate the impact of the introduction of a maneuverable vacuum extractor cup on the length of hospital stay after assisted vaginal birth in nulliparous women in a hospital where no vacuum devices were used. Methods: This single center retrospective analytical study included two groups of nulliparous women who had undergone an assisted vaginal birth. The 2 groups differ according to the availability or not of a maneuverable vacuum extractor cup. The first group includes the last 54 instrumental births until May 2017, when only obstetric forceps and Thierry's spatulas were available in our center; the second group includes the first 54 instrumental births since May 2018 in our center, when obstetric forceps, Thierry's spatulas and maneuverable vacuum extractor cup were available. Maneuverable vacuum extractor cups had been available for 12 months in the second group. Results: In the no vacuum cup group, Kjelland forceps and Thierry's spatulas were used in 29 (53.7%) and 25 (46.3%) of the 54 assisted vaginal births, respectively. In the vacuum available group, a vacuum cup was chosen in 30 (55.6%), Kjelland forceps were used in 18 (33.3%) and Thierry's spatulas in 6 (11.1%) of the assisted vaginal births. 22 women (40.7%) had a postpartum hospital stay longer than 3 days in the group with no maneuverable vacuum extractor cup availability, versus 3 women (5.6%) in the group with availability of a maneuverable vacuum extractor cup, p<0.001. Average postpartum hospital stay length was 3.17±0.803 days versus 2.81±0.585, p<0.001. There was also a significant reduction in the number of episiotomies. Conclusion: The introduction of a maneuverable vacuum extractor cup in a center where only forceps and Thierry's spatulas had been used resulted in a decrease in postpartum hospital stay in nulliparous women.(AU)

Objetivos: El objetivo de nuestro estudio es evaluar el impacto de la introducción de una ventosa obstétrica con cazoleta maniobrable en la duración de la estancia hospitalaria tras parto instrumental en mujeres nulíparas en un hospital donde no se utilizaban ventosas obstétricas. Métodos: Este estudio de cohortes retrospectivo unicéntrico incluyó 2 grupos de mujeres nulíparas sometidas a parto instrumental. Los 2 grupos se diferencian según la disponibilidad o no de ventosa obstétrica en el centro. El primer grupo se compone de las últimas 54 mujeres a las que se les asistió un parto instrumental hasta mayo del 2017, cuando solo había disponibilidad de fórceps obstétricos y espátulas de Thierry en nuestro centro; el segundo grupo se compone de las primeras 54 mujeres a las que se les asistió un parto instrumental desde mayo del 2018 en nuestro centro, cuando había disponibilidad de fórceps obstétricos, de espátulas de Thierry y de ventosa obstétrica con cazoleta maniobrable (esta última desde hacía 12 meses). Resultados: En el grupo sin disponibilidad de ventosa obstétrica, se utilizaron fórceps de Kjelland y espátulas de Thierry en 29 (53,7%) y 25 (46,3%) de los 54 partos instrumentales, respectivamente. En el grupo con disponibilidad de ventosa, se usó la ventosa en 30 (55,6%), fórceps de Kjelland en 18 (33,3%) y espátulas de Thierry en 6 (11,1%) de los partos instrumentales; 22 mujeres (40,7%) tuvieron una estancia hospitalaria tras el parto mayor de 3 días en el grupo sin disponibilidad de ventosa, frente a 3 mujeres (5,6%) en el grupo con disponibilidad de ventosa, p<0,001. La duración media de la estancia hospitalaria tras el parto fue de 3,17±0,803 días frente a 2,81±0,585, p<0,001. También hubo una reducción significativa en el número de episiotomías.(AU)

Protecting quantum entanglement from leakage and qubit errors via repetitive parity measurements.

Protecting quantum information from errors is essential for large-scale quantum computation. Quantum error correction (QEC) encodes information in entangled states of many qubits and performs parity measurements to identify errors without destroying the encoded information. However, traditional QEC cannot handle leakage from the qubit computational space. Leakage affects leading experimental platforms, based on trapped ions and superconducting circuits, which use effective qubits within many-level physical systems. We investigate how two-transmon entangled states evolve under repeated parity measurements and demonstrate the use of hidden Markov models to detect leakage using only the record of parity measurement outcomes required for QEC. We show the stabilization of Bell states over up to 26 parity measurements by mitigating leakage using postselection and correcting qubit errors using Pauli-frame transformations. Our leakage identification method is computationally efficient and thus compatible with real-time leakage tracking and correction in larger quantum processors.

Fast, High-Fidelity Conditional-Phase Gate Exploiting Leakage Interference in Weakly Anharmonic Superconducting Qubits.

Conditional-phase (cz) gates in transmons can be realized by flux pulsing computational states towards resonance with noncomputational ones. We present a 40 ns cz gate based on a bipolar flux pulse suppressing leakage (0.1%) by interference and approaching the speed limit set by exchange coupling. This pulse harnesses a built-in echo to enhance fidelity (99.1%) and is robust to long-timescale distortion in the flux-control line, ensuring repeatability. Numerical simulations matching experiment show that fidelity is limited by high-frequency dephasing and leakage by short-timescale distortion.

Circadian monitoring as an aging predictor.

The ageing process is associated with sleep and circadian rhythm (SCR) frailty, as well as greater sensitivity to chronodisruption. This is essentially due to reduced day/night contrast, decreased sensitivity to light, napping and a more sedentary lifestyle. Thus, the aim of this study is to develop an algorithm to identify a SCR phenotype as belonging to young or aged subjects. To do this, 44 young and 44 aged subjects were recruited, and their distal skin temperature (DST), activity, body position, light, environmental temperature and the integrated variable TAP rhythms were recorded under free-living conditions for five consecutive workdays. Each variable yielded an individual decision tree to differentiate between young and elderly subjects (DST, activity, position, light, environmental temperature and TAP), with agreement rates of between 76.1% (light) and 92% (TAP). These decision trees were combined into a unique decision tree that reached an agreement rate of 95.3% (4 errors out of 88, all of them around the cut-off point). Age-related SCR changes were very significant, thus allowing to discriminate accurately between young and aged people when implemented in decision trees. This is useful to identify chronodisrupted populations that could benefit from chronoenhancement strategies.

Impact of a shift work-like lighting schedule on the functioning of the circadian system in the short-lived fish Nothobranchius furzeri.

Adult Nothobranchius furzeri of the MZM-04/10 strain were individually kept and subjected to a "5 + 2" shifting lighting schedule (SHIFT) for 8 weeks in order to evaluate the desynchronizing effects of a simulated human-like shift-work schedule on the functioning of the circadian system (CS). With this aim, sixteen 21-week-old N. furzeri were placed into a Morning, Night and Evening schedule (lights on from 08:00 to 16:00, 00:00 to 08:00 and 16:00 to 00:00 h, respectively) and fed once a day in the middle of the corresponding photophase (12:00, 04:00 and 20:00 h, respectively). Then, in the weekends (2 days), fish were always returned to the Morning shift. As controls, 16 fish were maintained under a non-shifting LD cycle condition (CONTROL) throughout the whole experiment, with lights on from 08:00 to 16:00 h. Rest-activity rhythm (RAR) of fish subjected to SHIFT showed several symptoms of chronodisruption, such as a decrease in the percentage of diurnal activity and a reduction of the relative amplitude and the circadian function index with time. When a periodogram analysis was performed, RAR of N. furzeri under SHIFT conditions showed up to three separate circadian components: one longer than 24 h (26.5 h) that followed the weekly 8 h delays; a short-period component (~23 h) that was related to the weekend's phase advances, and finally, a 24 h component. The shifting LD schedule also affected fish CS at a molecular level, with several significant differences in the expression of core genes of the molecular clock (bmal1, clock, rorα, rev-erbα) between SHIFT and CONTROL animals. RAR impairment along with changes in clock gene expression could be associated with high stress and accelerated aging in these fish.

Multidimensional Circadian Monitoring by Wearable Biosensors in Parkinson's Disease.

Parkinson's disease (PD) is associated with several non-motor symptoms that may precede the diagnosis and constitute a major source of frailty in this population. The digital era in health care has open up new prospects to move forward from the qualitative and subjective scoring for PD with the use of new wearable biosensors that enable frequent quantitative, reliable, repeatable, and multidimensional measurements to be made with minimal discomfort and inconvenience for patients. A cross-sectional study was conducted to test a wrist-worn device combined with machine-learning processing to detect circadian rhythms of sleep, motor, and autonomic disruption, which can be suitable for the objective and non-invasive evaluation of PD patients. Wrist skin temperature, motor acceleration, time in movement, hand position, light exposure, and sleep rhythms were continuously measured in 12 PD patients and 12 age-matched healthy controls for seven consecutive days using an ambulatory circadian monitoring device (ACM). Our study demonstrates that a multichannel ACM device collects reliable and complementary information from motor (acceleration and time in movement) and common non-motor (sleep and skin temperature rhythms) features frequently disrupted in PD. Acceleration during the daytime (as indicative of motor impairment), time in movement during sleep (representative of fragmented sleep) and their ratio (A/T) are the best indexes to objectively characterize the most common symptoms of PD, allowing for a reliable and easy scoring method to evaluate patients. Chronodisruption score, measured by the integrative algorithm known as the circadian function index is directly linked to a low A/T score. Our work attempts to implement innovative technologies based on wearable, multisensor, objective, and easy-to-use devices, to quantify PD circadian rhythms in huge populations over extended periods of time, while controlling at the same time exposure to exogenous circadian synchronizers.

Evolution of Nanowire Transmon Qubits and Their Coherence in a Magnetic Field.

We present an experimental study of flux- and gate-tunable nanowire transmons with state-of-the-art relaxation time allowing quantitative extraction of flux and charge noise coupling to the Josephson energy. We evidence coherence sweet spots for charge, tuned by voltage on a proximal side gate, where first order sensitivity to switching two-level systems and background 1/f noise is minimized. Next, we investigate the evolution of a nanowire transmon in a parallel magnetic field up to 70 mT, the upper bound set by the closing of the induced gap. Several features observed in the field dependence of qubit energy relaxation and dephasing times are not fully understood. Using nanowires with a thinner, partially covering Al shell will enable operation of these circuits up to 0.5 T, a regime relevant for topological quantum computation and other applications.

Capacity estimation and verification of quantum channels with arbitrarily correlated errors.

The central figure of merit for quantum memories and quantum communication devices is their capacity to store and transmit quantum information. Here, we present a protocol that estimates a lower bound on a channel's quantum capacity, even when there are arbitrarily correlated errors. One application of these protocols is to test the performance of quantum repeaters for transmitting quantum information. Our protocol is easy to implement and comes in two versions. The first estimates the one-shot quantum capacity by preparing and measuring in two different bases, where all involved qubits are used as test qubits. The second verifies on-the-fly that a channel's one-shot quantum capacity exceeds a minimal tolerated value while storing or communicating data. We discuss the performance using simple examples, such as the dephasing channel for which our method is asymptotically optimal. Finally, we apply our method to a superconducting qubit in experiment.

Shoulder patient-specific guide: First experience in 10 patients indicates room for improvement.

BACKGROUND: Implantation of the glenoid component of a total shoulder prosthesis can be facilitated by using a patient-specific guide (PSG) designed to ensure replication of the preoperatively planned position. The objective of this study was to assess the reliability and accuracy of a PSG in replicating the planned glenoid component position during total shoulder arthroplasty (TSA). HYPOTHESIS: Additional criteria should be used for 3D preoperative planning and PSG design to further improve the accuracy of glenoid component positioning. MATERIAL AND METHODS: We studied 10 patients who underwent TSA with use of a PSG to position the glenoid component after preoperative 3D planning. Postoperative glenoid version and tilt were measured and compared to the planned values. We also used new criteria to assess implant rotation and global 3D position, as well as accuracy of the 3D pilot hole for the glenoid guide-pin. RESULTS: Mean errors in glenoid position were -1.7°±4.4° for version, -0.4°±4.9° for tilt, and 6.0°±13.5° for rotation. Mean difference in global orientation of the glenoid implant versus the planned value was 4.9°±2.5°. Mean 3D discrepancy in glenoid pilot hole position was 2.9±0.5mm; the discrepancy was greater in the mediolateral direction (1.9±0.9mm) than in the supero-inferior (1.1±1.2mm) and antero-posterior (0.8±1.2mm) directions. DISCUSSION: The poor performance of the PSG in controlling rotation and reaming may explain the difference in global glenoid position compared to the planned value. Improvements in PSG design to incorporate these two parameters deserve consideration. LEVEL OF EVIDENCE: II, prospective cohort study.

Exceso ponderal infantil y adolescente: factores modificables, herencia genética y percepción de la imagen corporal / Excess weight in children and adolescents: modifiable factors, genetic inheritance and body image perception

Introducción: el sobrepeso y obesidad alcanzan una alta prevalencia entre niños y adolescentes en España. Los hábitos modificables, la carga genética y la percepción del peso empeoran con los años, convirtiendo a los niños en adultos con sobrepeso. Se analizó la relevancia de distintos factores modificables (hábitos alimentarios, actividad física, sedentarismo y horas de sueño), la herencia genética, así como la percepción de su imagen corporal, en el exceso ponderal de niños y adolescentes. Material y métodos: estudio observacional retrospectivo de 101 escolares de Madrid (edad media de diez años), con recogida de datos antropométricos (peso, talla, pliegues cutáneos y circunferencia de cintura), dietéticos (KidMed®), de actividad física (IPAQ® adaptado), sedentarismo, horas de sueño y percepción del peso e imagen corporal. Resultados: el 31% de los niños presentaba exceso ponderal. Un 53,4% necesitaba mejorar la dieta. Fue mayor el número de participantes con normopeso que no seguían una alta adherencia a la dieta mediterránea que aquellos con sobrepeso-obesidad que sí se adherían. No se observó correlación estadísticamente significativa entre el estado ponderal (según el percentil de peso) y las características corporales de los padres, pero sí en función del índice de masa corporal (IMC).A un 70% de obesos y un 50% de desnutridos les gustaría pesar lo mismo. Conclusiones: los factores modificables no se relacionaron con un mayor exceso ponderal. El peso de los progenitores tuvo influencia en el estado ponderal de los hijos, aunque no se obtuvieron resultados estadísticamente significativos al analizar los factores modificables y la herencia en conjunto (AU)

Introduction: overweight and obesity achieve a high prevalence among children and adolescents in Spain. Modifiable habits, combined with the genetic load and weight perception, declines over the years making children overweight adults. Our aim was to analyze the relevance in excess weight of various modifiable factors (dietary habits, physical activity, sedentary lifestyle and sleep), heredity and body image perception in children and adolescents. Methods: a retrospective observational study of 101 schoolchildren in Madrid (mean age 10 years) was performed with collection of anthropometric (weight, height, skinfold thickness and waist circumference), dietary (KidMed), physical activity (IPAQ adapted), sedentary lifestyle, sleep and perception of weight and body image data. Results: 31% of children had excess weight. 53.4% ​​needed diet improvement. The number of participants with normal weight who did not follow a high adherence to the Mediterranean diet was greater than those with overweight-obesity who did adhered. No statistically significant results between weight status (according to weight percentile) and body parental characteristics were obtained, but according to BMI. 70% of obese and 50% of malnourished would like to stay in their weigh. Conclusion: modifiable factors were not associated with an increased excess weight. Parents’ weight had some influence on the weight status of children, although no statistically significant results were obtained when both modifiable factors and heredity were analyzed altogether (AU)

Repeated quantum error correction on a continuously encoded qubit by real-time feedback.

Reliable quantum information processing in the face of errors is a major fundamental and technological challenge. Quantum error correction protects quantum states by encoding a logical quantum bit (qubit) in multiple physical qubits. To be compatible with universal fault-tolerant computations, it is essential that states remain encoded at all times and that errors are actively corrected. Here we demonstrate such active error correction on a continuously protected logical qubit using a diamond quantum processor. We encode the logical qubit in three long-lived nuclear spins, repeatedly detect phase errors by non-destructive measurements, and apply corrections by real-time feedback. The actively error-corrected qubit is robust against errors and encoded quantum superposition states are preserved beyond the natural dephasing time of the best physical qubit in the encoding. These results establish a powerful platform to investigate error correction under different types of noise and mark an important step towards fault-tolerant quantum information processing.

Validation of an innovative method, based on tilt sensing, for the assessment of activity and body position.

Since there is less movement during sleep than during wake, the recording of body movements by actigraphy has been used to indirectly evaluate the sleep-wake cycle. In general, most actigraphic devices are placed on the wrist and their measures are based on acceleration detection. Here, we propose an alternative way of measuring actigraphy at the level of the arm for joint evaluation of activity and body position. This method analyzes the tilt of three axes, scoring activity as the cumulative change of degrees per minute with respect to the previous sampling, and measuring arm tilt for the body position inference. In this study, subjects (N = 13) went about their daily routine for 7 days, kept daily sleep logs, wore three ambulatory monitoring devices and collected sequential saliva samples during evenings for the measurement of dim light melatonin onset (DLMO). These devices measured motor activity (arm activity, AA) and body position (P) using the tilt sensing of the arm, with acceleration (wrist acceleration, WA) and skin temperature at wrist level (WT). Cosinor, Fourier and non-parametric rhythmic analyses were performed for the different variables, and the results were compared by the ANOVA test. Linear correlations were also performed between actimetry methods (AA and WA) and WT. The AA and WA suitability for circadian phase prediction and for evaluating the sleep-wake cycle was assessed by comparison with the DLMO and sleep logs, respectively. All correlations between rhythmic parameters obtained from AA and WA were highly significant. Only parameters related to activity levels, such as mesor, RA (relative amplitude), VL5 and VM10 (value for the 5 and 10 consecutive hours of minimum and maximum activity, respectively) showed significant differences between AA and WA records. However, when a correlation analysis was performed on the phase markers acrophase, mid-time for the 10 consecutive hours of highest (M10) and mid-time for the five consecutive hours of lowest activity (L5) with DLMO, all of them showed a significant correlation for AA (R = 0.607, p = 0.028; R = 0.582, p = 0.037; R = 0.620, p = 0.031, respectively), while for WA, only acrophase did (R = 0.621, p = 0.031). Regarding sleep detection, WA showed higher specificity than AA (0.95 ± 0.01 versus 0.86 ± 0.02), while the agreement rate and sensitivity were higher for AA (0.76 ± 0.02 versus 0.66 ± 0.02 and 0.71 ± 0.03 versus 0.53 ± 0.03, respectively). Cohen's kappa coefficient also presented the highest values for AA (0.49 ± 0.04) and AP (0.64 ± 0.04), followed by WT (0.45 ± 0.06) and WA (0.37 ± 0.04). The findings demonstrate that this alternative actigraphy method (AA), based on tilt sensing of the arm, can be used to reliably evaluate the activity and sleep-wake rhythm, since it presents a higher agreement rate and sensitivity for detecting sleep, at the same time allows the detection of body position and improves circadian phase assessment compared to the classical actigraphic method based on wrist acceleration.

Ontogeny and aging of the distal skin temperature rhythm in humans.

In circadian terms, human ontogeny is characterized by the emergence of a daily pattern, from a previous ultradian pattern, for most variables during the first 6 months of life. Circadian aging in humans is characterized by a phase advance, accompanied by rhythm fragmentation and flattening. Despite an expanding body of literature focused on distal skin temperature, little information is available about the ontogeny and practically nothing about age-related changes in this rhythm. Thus, the aim was to evaluate the degree of maturation and aging of the circadian pattern of distal skin temperature to identify those parameters that are modified throughout life and could be used to differentiate subjects according to their age. For this, distal skin temperature was measured in 197 volunteers (55 % women), including babies aged 15 days (30 subjects), 1 month (28 subjects), 3 months (31 subjects), and 6 months (10 subjects); young adults aged 19 years (37 subjects); middle-aged persons aged 46 years (27 subjects); older people aged 72 (34 subjects). Circadian system maturation was associated with an increase in amplitude and a reduction in skin temperature during sleep. During adulthood, women showed a more robust pattern (lower fragmentation, and higher night-time temperature, amplitude, circadian function index, and first harmonic relative power); however, these differences were lost with aging, a period of life that was consistently associated with a phase advance of the rhythm. In summary, distal skin temperature pattern can be used as a robust variable to discern between different ages throughout the life.

Circadian phase assessment by ambulatory monitoring in humans: correlation with dim light melatonin onset.

The increased prevalence of circadian disruptions due to abnormal coupling between internal and external time makes the detection of circadian phase in humans by ambulatory recordings a compelling need. Here, we propose an accurate practical procedure to estimate circadian phase with the least possible burden for the subject, that is, without the restraints of a constant routine protocol or laboratory techniques such as melatonin quantification, both of which are standard procedures. In this validation study, subjects (N = 13) wore ambulatory monitoring devices, kept daily sleep diaries and went about their daily routine for 10 days. The devices measured skin temperature at wrist level (WT), motor activity and body position on the arm, and light exposure by means of a sensor placed on the chest. Dim light melatonin onset (DLMO) was used to compare and evaluate the accuracy of the ambulatory variables in assessing circadian phase. An evening increase in WT: WTOnset (WTOn) and "WT increase onset" (WTiO) was found to anticipate the evening increase in melatonin, while decreases in motor activity (Activity Offset or AcOff), body position (Position Offset (POff)), integrative TAP (a combination of WT, activity and body position) (TAPOffset or TAPOff) and an increase in declared sleep propensity were phase delayed with respect to DLMO. The phase markers obtained from subjective sleep (R = 0.811), WT (R = 0.756) and the composite variable TAP (R = 0.720) were highly and significantly correlated with DLMO. The findings strongly support a new method to calculate circadian phase based on WT (WTiO) that accurately predicts and shows a temporal association with DLMO. WTiO is especially recommended due to its simplicity and applicability to clinical use under conditions where knowing endogenous circadian phase is important, such as in cancer chronotherapy and light therapy.

Wrist skin temperature, motor activity, and body position as determinants of the circadian pattern of blood pressure.

Although the circadian blood pressure (BP) pattern has been extensively studied, the determinants of this rhythm are not fully understood. Peripheral vasodilatation is a regulatory mechanism for BP maintenance. However, it remains to be established whether the increase of nocturnal distal skin temperature associated with heat loss could also reflect the dipping status. For the first time, this paper investigates the relationship between BP and skin wrist temperature (WT), to evaluate whether the WT circadian rhythm can serve as screening procedure to detect dipping/non-dipping BP patterns. In addition, the authors compare the relationship between WT and other variables previously described as determinants of the BP pattern, such as physical activity and body position. Measurements of WT, motor activity, and body position for 5 d, plus ambulatory BP for 24-h during that span, were obtained from 28 diurnally active normotensive volunteers. WT was negatively correlated, whereas activity and body position were positively correlated, with systolic and diastolic BPs. However, these relationships were stronger during the rest than activity phase. In addition, a 78.6% concordance was detected between the observed dips in BP and the predicted BP pattern calculated based on the WT rhythm. Thus, these results suggest that the increase in WT produced by heat loss during the rest phase through peripheral skin blood vessels is the result of blood vessel vasodilatation reflexes in response to a shift from a standing to a supine position, together with shift in the circadian sympathetic/parasympathetic balance (nocturnal parasympathetic activation). In conclusion, WT could be considered as a potential new screening procedure to implement the diagnosis of non-dipping BP pattern.

Occurrence and predictors of pressure ulcers during primary in-patient spinal cord injury rehabilitation.

STUDY DESIGN: Multicenter prospective cohort study. OBJECTIVES: To determine the occurrence and predictors for pressure ulcers in patients with spinal cord injury (SCI) during primary in-patient rehabilitation. SETTING: Eight Dutch rehabilitation centres with specialized SCI units. METHODS: The occurrence, location and stage of pressure ulcers were registered between admission and start of functional rehabilitation (called acute rehabilitation phase) and between start of functional rehabilitation and discharge. Possible risk factors for the occurrence of pressure ulcers during functional rehabilitation (personal and lesion characteristics, complications and functional independence) were measured at the start of functional rehabilitation and were entered as predictors in univariate and multivariate logistic regression analysis with pressure ulcers during functional rehabilitation as the dependent variable. RESULTS: Data for 193 patients (86%) were available. The occurrence of pressure ulcers, including stage 1, was 36.5% during acute rehabilitation phase and 39.4% during functional rehabilitation. Most pressure ulcers were located at the sacrum (43%), followed by heel (19%) and ischium (15%). The significant risk factors for pressure ulcers during functional rehabilitation were motor completeness of the lesion, tetraplegia, pressure ulcer during acute rehabilitation phase, pneumonia and/or pulmonary disease, low score on the Functional Independence Measure (FIM) self-care, continence, transfers, locomotion and total FIM motor score. Having had a pressure ulcer during acute rehabilitation phase was the strongest risk factor. CONCLUSION: The occurrence of pressure ulcers was comparable with other studies. A few significant risk factors were found, of which having had a pressure ulcer during acute rehabilitation phase being the strongest predictor.

Melatonin, a potential therapeutic agent for smooth muscle-related pathological conditions and aging.

Increases or decreases in the contractile response of smooth muscle underlie important pathological conditions such as hypertension, incontinence and altered gastrointestinal transit. These disorders are also frequently encountered in the aged population. Oxidative stress and inflammation are key features in the initiation, progression, and clinical manifestations of smooth muscle disorders. Melatonin, the major secretory product of the pineal gland, has free radical scavenging and antioxidative properties and protects against oxidative insult. Recently, widespread interest has grown regarding the apparent protective effects of melatonin on smooth muscle dysfunction. "In vitro" studies have shown that melatonin decreased vascular tone of vascular beds from control, hypertensive or aged animals, through the reduction of adrenergic contraction and the increase in acetylcholine-induced relaxation. "In vivo", melatonin also attenuates sympathetic tone by direct activation of melatonin receptors, scavenging free radicals or increasing NO availability in the central nervous system. In the gastrointestinal tract, melatonin treatment improves age-related impairments in gallbladder contractility and prevents deleterious effects of cholecystitis on smooth muscle and the enteric nervous system through suppression of oxidative stress. In addition, melatonin improves colonic transit time in constipation-predominant IBS patients. Melatonin is also able to restore impaired contractility of the detrusor muscle from old animals through normalization of Ca(2+) dependent and independent contraction, mitochondrial polarity, neuromuscular function and oxidative stress, which would explain the effects of melatonin counteracting cystometric changes in senescent animals. It also reverses bladder damage following ischemia/reperfusion. In conclusion, melatonin may be a promising candidate for future research of agents that modulate smooth muscle motility.

El sistema circadiano en el anciano: valoración clínica e intervenciones terapéuticas / No disponible

Todos los seres vivos en el planeta Tierra estamos sometidos a un entorno cambiante y cíclico que ha contribuido al desarrollo de un reloj biológico que les permite la anticipación a estos cambios. Este reloj necesita un conjunto de sincronizadores externos (zeitgebers) que lo pongan en hora cada día. Algunos de estos sincronizadores son la luz, el horario regular de comidas, ejercicio moderado, contactos sociales... Durante el envejecimiento, el reloj biológico va perdiendo paulatinamente su capacidad de marcar el ritmo al organismo. Es por ello que las terapias cronobiológicas que tratan de potenciar las señales sincronizadoras tienen mucho interés, no sólo por su eficacia, sino también por su bajo costo y la ausencia de efectos secundarios. En primer lugar y teniendo en cuenta que el mejor sincronizador para el reloj biológico es la luz, la terapia más eficaz es la luminoterapia con luz brillante. En segundo lugar habría que recomendar el mantenimiento de un horario estable de comidas, de ejercicio físico moderado y relaciones sociales. Todas estas son medidas que mejoran las entradas al reloj pero también podemos mejorar las salidas. El reloj marca el ritmo al organismo a través de una hormona, la melatonina. Con el envejecimiento, los niveles de melatonina endógena van disminuyendo y por ello, una terapia útil es la administración de melatonina exógena o de alguno de sus agonistas farmacológicos. Esta hormona actúa como señal temporal, pero igualmente como inductora del sueño, hormona antienvejecimiento, oncostática frente a ciertos tipos de tumores e inmunomoduladora. Para conocer el estado del sistema circadiano (el reloj biológico) y poder optimizar las terapias, es necesario medir algunos ritmos que se denominan «marcadores». Se trata de ritmos muy estables y que están controlados directamente por el reloj. Algunos ejemplos de estos ritmos son el de temperatura periférica y el de actividad motora. En ambos casos se trata de ritmos que se determinan mediante el empleo de técnicas no invasivas (AU)

No disponible

Influencia del ritmo de temperatura periférica sobre el ciclo sueño-vigilila / Influence of temperatura body rhythm on the sleep-wake cycle

La estrecha relación entre el ciclo de sueño vigilia y el ritmo de temperatura corporal es un hecho que se conoce desde hace tiempo, de tal forma que aumenta la propensión al sueño cuando la temperatura corporal central se acerca a su mínimo valor. No obstante, y dadas los inconvenientes metodológicos que plantea la medida del ritmo de temperatura corporal central (TCC) de forma continua, ha ido ganando interés la medida del ritmo de temperatura periférica (TP) como índice de somnolencia. El comportamiento de esta nueva variable en relación con el sueño es opuesto al del ritmo de TCC, de modo que son las elevaciones de TP las que van asociadas a una mayor propensión a dormir, mientras que los descensos inducen estados de vigilia. La TP no sólo se anticipa a los cambios que suceden en el ritmo de TCC, lo que subraya su carácter endógeno, sino que además constituye una señal que actúa sobre los centros reguladores del sueño, modificando la propensión al sueño. Es más, los datos más recientes apuntan a que la caída en la TCC, que se encuentra bajo el control del sistema circadiano, estaría fundamentalmente causada por un aumento en la disipación de calor, gracias a la vasodilatación de la piel y su calentamiento, y sería por lo tanto, la elevación de la temperatura distal, y no tanto la caída en la TCC, la señal que desencadena el inicio y mantenimiento del sueño. Este hecho permite introducir modificaciones en los patrones de comportamiento previos al sueño orientados a mejorar los cambios termorreguladores que facilitan el mismo (AU)

It has long been known that the sleep-wake cycle is closely related to the body temperature rhythm, in such a way that sleep propensity increases when the core body temperature (CBT) reaches a minimun value. However, the unpleasantness associated with the methods used for continuous CBT recordings has recently increased the interest for peripheral temperature (PT) measurements as an index of sleepeness. The peripheral temperature pattern is opposed to that of CBT with respect to sleep, since the propensity to fall asleep increases along with PT, while PT decrements are associated with alertness. Changes in peripheral temperature rhythm precede those of CBT, highlighting its endogenous component, and demonstrating that PT acts as a signal for sleep regulating centers. In addition, more recent data indicates that, under the circadian sistem control, CBT lowering is specially dependent on heat loss by skin vasodilation and heating, which means that it is the PT increment, rather than the CBT drop, which triggers sleep onset and its consolidation. Based on this assumption a number of behavioral pattern modifications can be suggested to improve those thermoregutranslatory changes that could facilitate sleep (AU)