RESUMEN
Continuous administration of low-intensity whole-body vibration (WBV) gradually diminishes bone mechanosensitivity over time, leading to a weakening of its osteogenic effect. We investigated whether discretizing WBV into bouts with short rest intervals was effective in enhancing osteoporotic bone repair. Ten-week-old female mice were ovariectomized and underwent drill-hole defect surgery (Day 0) on the right tibial diaphysis at 11 weeks of age. The mice underwent one of three regimens starting from Day 1 for 5 days/week: continuous WBV at 45 Hz and 0.3 g for 7.5 min/day (cWBV); 3-s bouts of WBV at 45 Hz, 0.3 g followed by 9-s rest intervals, repeated for 30 min/day (repeated bouts of whole-body vibration with short rest intervals [rWBV]); or a sham treatment. Both the cWBV and rWBV groups received a total of 20,250 vibration cycles per day. On either Day 7 or 14 posteuthanasia (n = 6/group/timepoint), the bone and angiogenic vasculature in the defect were computed tomography imaged using synchrotron light. By Day 14, the bone repair was most advanced in the rWBV group, showing a higher bone volume fraction and a more uniform mineral distribution compared with the sham group. The cWBV group exhibited an intermediate level of bone repair between the sham and rWBV groups. The rWBV group had a decrease in large-sized angiogenic vessels, while the cWBV group showed an increase in such vessels. In conclusion, osteoporotic bone repair was enhanced by WBV bouts with short rest intervals, which may potentially be attributed to the improved mechanosensitivity of osteogenic cells and alterations in angiogenic vasculature.
Asunto(s)
Ratones Endogámicos C57BL , Osteoporosis , Vibración , Animales , Vibración/uso terapéutico , Femenino , Osteoporosis/terapia , RatonesRESUMEN
Histological examination of specimens from 22 donated elderly cadavers and 15 human fetuses revealed that the cricopharyngeus muscle (CPM) provided (1) posterior circular muscle fibers adjacent to the external aspect of the uppermost esophageal circular muscle and (2) a thin anterior sling connecting to that same muscle. Another thick lateral bundle of longitudinal muscle originated independently from a fascia covering the posterior cricoarytenoideus muscle, extended laterally and posteriorly, and occupied a space after the CPM had disappeared at the anterolateral angle of the esophagus below the cricoid. The thick fascia contained abundant elastic fibers along the internal surface of the pharyngeal constrictors (posteromedial elastic lamina), but was interrupted or discontinued near the cricoid origin of the CPM. As no submucosal smooth muscles or elastic fibers were connected to it, the CPM did not accompany a specific elastic structure at the interface between the pharyngeal and esophageal muscles. In fetuses, the medial half of the CPM was inserted into the cricoid while the lateral half continued to the sternothyroideus muscle or ended at a fascia covering the cricothyroideus. These anterolateral ends provided a mechanical load for longitudinal growth of the pharyngeal constrictors. Consequently, the CPM was unlikely to develop and grow to form the upper esophageal sphincter, and the muscle bundle crossing the lateral aspect of the pharyngo-esophageal junction appeared to have a secondary passive role as a sphincter. This situation contrasts with that of another sphincter in the human body formed from striated muscle. Clin. Anat., 33:782-794, 2020. © 2019 Wiley Periodicals, Inc.
Asunto(s)
Esfínter Esofágico Superior/anatomía & histología , Músculos Faríngeos/anatomía & histología , Anciano , Anciano de 80 o más Años , Cadáver , Esfínter Esofágico Superior/embriología , Femenino , Feto , Humanos , Masculino , Músculos Faríngeos/embriologíaRESUMEN
An 82-year-old man with severe cardiac dysfunction due to ischemic cardiac myopathy was diagnosed as indication for biventricular pacing. His left ventricular ejection fraction was 22%. Because of difficulty in coronary sinus lead fixation, epicardial lead implantation through a thoracotomy under general anesthesia was scheduled. Intraaortic balloon pumping (IABP) was started prior to the operation. Anesthesia was induced by midazolam and fentanyl, and maintained with fentanyl and low dose propofol infusion. Milrinone was infused throughout the operation. Except for just after the anesthesia induction, systolic blood pressure was kept well around 100 mmHg. The operation was completed without any ploblems. NYHA classification improved markedly (class IV to class II) by biventricular pacing. Using IABP, we could maintain blood pressure and stabilize hemodynamics during left ventricular lead implantation in a patient with severe heart failure.
Asunto(s)
Anestesia General , Estimulación Cardíaca Artificial , Electrodos Implantados , Insuficiencia Cardíaca/terapia , Marcapaso Artificial , Anciano de 80 o más Años , Ventrículos Cardíacos , Humanos , Contrapulsador Intraaórtico , Cuidados Intraoperatorios , Masculino , Monitoreo Intraoperatorio , Pericardio , Índice de Severidad de la EnfermedadRESUMEN
BACKGROUND: Although there is a considerable difference in the number of clinical reports of neurologic injury between spinal anesthesia and other regional techniques, there are no animal data concerning a difference in the local anesthetic neurotoxicity between intrathecal and epidural administration. In the current study, the functional and morphologic effects of lidocaine administered intrathecally and epidurally were compared in rats. METHODS: Male rats were implanted with an intrathecal or epidural catheter through L4-L5 vertebra in the caudal direction. In experiment 1, to determine relative anesthetic potency, 16 rats received repetitive injections of 2.5% lidocaine into intrathecal or epidural space in different volumes and were examined for tail flick test for 90 min. In experiment 2, to ascertain whether the relative potency obtained in experiment 1 would apply to other concentrations of lidocaine, additional rats received saline, 1%, 2.5%, or 5% lidocaine in a volume of 20 or 100 microl through the intrathecal or epidural catheter, respectively. In experiment 3, additional rats that received saline, 2.5% lidocaine, or 10% lidocaine in a volume of 20 or 100 microl through the intrathecal or epidural catheter, respectively, were examined for persistent functional impairment and morphologic damage. RESULTS: In experiment 1, the two techniques produced parallel dose-effect curves that significantly differed from each other. The potency ratio calculated was approximately 4.72 (3.65-6.07):1 for intrathecal:epidural lidocaine. In experiment 2, every lidocaine solution produced a similar increase in tail flick latency for the two techniques. In experiment 3, five of eight rats given 10% intrathecal lidocaine incurred functional impairment 4 days after injection, whereas no rats in the other groups did. Significantly more morphologic damage was observed in rats given 10% intrathecal lidocaine than in those given 10% epidural lidocaine. CONCLUSIONS: Persistent functional impairment occurred only after intrathecal lidocaine. Histologic damage in the nerve roots and the spinal cord was less severe after epidural lidocaine than after intrathecal lidocaine. The current results substantiate the clinical impression that neurologic complications are less frequent after epidural anesthesia than after spinal anesthesia.
Asunto(s)
Anestesia Epidural/métodos , Lidocaína/administración & dosificación , Lidocaína/toxicidad , Dimensión del Dolor/efectos de los fármacos , Médula Espinal/efectos de los fármacos , Anestesia Epidural/efectos adversos , Animales , Relación Dosis-Respuesta a Droga , Inyecciones Espinales , Masculino , Dimensión del Dolor/métodos , Ratas , Ratas Sprague-Dawley , Médula Espinal/patologíaRESUMEN
BACKGROUND: Haemodynamic effects of caudal anaesthesia in children have not been fully investigated. In the present study, we evaluated pulmonary haemodynamics during caudal anaesthesia in otherwise healthy children using Doppler-echocardiography. METHODS: Fifteen children undergoing elective lower abdominal surgery were randomly divided into two groups: nine children received 1.5% lidocaine and six physiological saline in the caudal epidural space. General anaesthesia was slowly induced and maintained using nitrous oxide and sevoflurane in oxygen. An epidural catheter was inserted into the caudal epidural space. Haemodynamic data including those with echocardiography were measured before and after epidural administration of lidocaine or saline. RESULTS: Mean blood pressure, end diastolic diameter of the left ventricle, ejection fraction of the left ventricle and mean velocity circumferential fibre shortening did not change in either group following caudal epidural block. Indices of pulmonary Doppler flow velocity, including peak velocity of pulmonary flow and acceleration-to-ejection time ratio, demonstrated a significant decrease after caudal lidocaine, but not after saline. CONCLUSIONS: Our data suggest that pulmonary Doppler flow velocity changes during caudal epidural anaesthesia, probably due to an increase in the pulmonary arterial resistance.