Medicine, Health Care and Philosophy - Can transfusions of blood plasma slow down ageing or even rejuvenate people? Recent preclinical studies and experimental tests inspired by the technique known... 相似文献
In our series of 525 patients operated on for acoustic neuroma, there were three false-positive computed tomography findings resulting in unnecessary surgery. The histories and results of laboratory investigations and surgery are presented. Discussion of the outcome had gadolinium-enhanced magnetic resonance imaging been performed is presented. 相似文献
Background: Airway irritation was hypothesized to trigger the transient cardiovascular stimulation associated with desflurane. The authors administered desflurane during cardiopulmonary bypass (CPB), thus avoiding airway contact, and compared the effects of rapid increases of desflurane to 1.5 MAC on systemic vascular resistance index (SVRI) and catecholamine response to those of 1.5 MAC sevoflurane.
Methods: Forty-eight patients, undergoing elective coronary bypass surgery, were randomly allocated to receive either desflurane or sevoflurane during hypothermic (32-33 [degree sign] Celsius) nonpulsatile CPB at exhaust gas concentrations of 1.5 MAC for 15 min. SVRI was calculated at baseline, 1, 2, 3, 4, 5, 7, 9, 12, and 15 min after starting volatile anesthetics' delivery. Plasma catecholamine concentrations were determined in 12 desflurane-treated patients and 12 sevoflurane-treated patients at baseline, 5, and 15 min.
Results: The time-course of Delta SVRI, (changes in SVRI from baseline), from baseline to 5 min was significantly different between desflurane- and sevoflurane-treated patients, whereas there was no difference from 7 to 15 min. In the desflurane group, SVRI from 1 to 7 min remained unchanged to baseline level, thereafter declining to significantly lower values at 9, 12, and 15 min compared with values from 0 to 5 min, whereas sevoflurane produced an immediate and significant reduction in SVRI. With desflurane, catecholamine concentrations remained unchanged to baseline level at 5 and 15 min; with sevoflurane, they decreased with time. 相似文献
Investigators often study rats by microCT to investigate the pathogenesis and treatment of skeletal disorders in humans. However, microCT measurements provide information only on bone mineral content and not the solid matrix. CT scans are often carried out on cancellous bone, which contains a significant volume of marrow cells, stroma, water, and fat, and thus the apparent bone mineral density (BMD) does not reflect the mineral density within the matrix, where the mineral crystals are localized. Water- and fat-suppressed solid-state proton projection imaging (WASPI) was utilized in this study to image the solid matrix content (collagen, tightly bound water, and other immobile molecules) of rat femur specimens, and meet the challenges of small sample size and demanding submillimeter resolution. A method is introduced to recover the central region of k-space, which is always lost in the receiver dead time when free induction decays (FIDs) are acquired. With this approach, points near the k-space origin are sampled under a small number of radial projections at reduced gradient strength. The typical scan time for the current WASPI experiments was 2 hr. Proton solid-matrix images of rat femurs with 0.4-mm resolution and 12-mm field of view (FOV) were obtained. This method provides a noninvasive means of studying bone matrix in small animals. 相似文献
Poly[nitrilo-bis(phenylamino)phosphoranetriyl]s ( 3a–d ) were synthesized and characterized in dilute solution and in the solid state. The synthesis was accomplished by thermal polymerization of of 2,2,4,4,6,6-hexachloro--triazatriphosphorane ( 1 ) at 240°C, followed by the reaction of the soluble product, poly(nitrilodichlorophosphoranetriyl) ( 2 ), with aniline or its derivatives. Elemental analyses show the presence of some residual chlorine, which, according to the IR spectra, does not seem to be ascribed to an incomplete substitution. All the polymers have intrinsic viscosities in tetrahydrofuran higher than 100ml g?1, and high weight average molecular weights (Mw ≥ 7 · 105). The molecular weight distribution is very broad (Mw/Mn ≥ 13,4) which could suggest either a branched structure or a complex mechanism of polymerization. From DSC measurements the glass transition temperatures are found to be between 70 and 98°C and the related values of specific heat increments, ΔC,p, are between 0,13 J g?1 K?1 and 0,27 J g?1 K?1; the densities are in the order of 1,3 g ml?1. 相似文献
The occurence of the human and rat epidermal SH-protease inhibitors in various human and rat tissues was studied by double radial immunodiffusion against specific antisera to the inhibitors. An immunoreactive protein was found in the extracts prepared from human and rat epidermis and from eosophageal and vaginal squamous epithelia, and from rat pro-ventricular squamous epithelium. No immunoreactive protein was found in man or rat in any other of their tissues, studied by us. The results strongly suggest that a protein reminiscent of the human or rat epidermal SH-protease inhibitor is present in squamous epithelia but not in other tissues. The identity of the epidermal inhibitor and the immunoreactive protein in the other squamous epithelia was confirmed by immunodiffusion, immunoelectrophoresis and gel chromatography, and by immunoinhibition of the papain inhibiting activity of the human epidermal and oesophageal inhibitors by gammaglobulins separated from antiserum to the human epidermal inhibitor. 相似文献
Alport syndrome (AS) is caused by mutations in collagen IV, which is widespread in the basement membranes of many organs, including the kidneys, eyes, and ears. Whereas the effects of collagen IV changes in the cochlea are well known, no changes have been described in the posterior labyrinth. The aim of this study was to investigate both the auditory and the vestibular function of a group of individuals with AS. Seventeen patients, aged 9–52, underwent audiological tests including pure‐tone and speech audiometry, immittance test and otoacoustic emissions and vestibular tests including video head impulse test, rotatory test, and vestibular evoked myogenic potentials. Hearing loss affected 25% of the males and 27.3% of the females with X‐linked AS. It was sensorineural with a cochlear localization and a variable severity. 50% of the males and 45.4% of the females had a hearing impairment in the high‐frequency range. Otoacoustic emissions were absent in about one‐third of the individuals. A peripheral vestibular dysfunction was present in 75% of the males and 45.4% of the females, with no complaints of vertigo or dizziness. The vestibular impairment was compensated and the vestibulo‐ocular reflex asymmetry was more evident in rotatory tests carried out at lower than higher speeds; a vestibular hypofunction was present in all hearing impaired ears although it was also found in subjects with normal hearing. A posterior labyrinth injury should be hypothesized in AS even when the patient does not manifest hearing disorders or evident signs of renal failure. 相似文献