NK Cells Rapidly Reject Allogeneic Bone Marrow in the Spleen Through a Perforin- and Ly49D-Dependent, but NKG2D-Independent Mechanism

We have used a sensitive and specific in vivo killing assay to monitor the kinetics, anatomic location and mechanisms controlling NK-mediated rejection of Balb/c bone marrow by C57BL/6 natural killer (NK) cells. We find that NK killing of fully allogeneic bone marrow is a rapid, highly efficient process, leading to substantial rejection of transplanted marrow within 6 h of transplant and elimination of 85% of the transplanted cells within 2 days. NK-mediated rejection occurred predominantly in the spleen, with sparing of rejection in the bone marrow and lymph nodes. Rejection was dependent on Perforin gene function, but was independent of interferon-gamma. Finally, rejection of Balb/c bone marrow by B6 NK cells required signaling through the Ly49D receptor, but occurred despite blockade of NKG2D, which distinguishes these results from previous studies using semiallogeneic transplant pairs. These results identify NK cells as highly active mediators of bone marrow rejection, and suggest that inhibiting NK function early during transplantation may increase the efficiency of engraftment and allow successful engraftment of limiting doses of donor bone marrow.     

Effects of gastric bypass procedures on bone mineral density,calcium, parathyroid hormone,and vitamin d

Weight loss after gastric bypass procedures has been well studied, but the long-term metabolic sequelae are not known. Data on bone mineral density (BMD), calcium, parathyroid hormone, and vitamin D were collected preoperatively and at yearly intervals after gastric bypass procedures. A total of 230 patients underwent preoperative BMD scans. Fifteen patients were osteopenic preoperatively, and three patients subsequently developed osteopenia postoperatively within the first year. No patient had or developed osteoporosis. At 1 year, total forearm BMD decreased by 0.55% (n = 91; P = .03) and radius BMD had increased overall by 1.85% (n = 23; P = .008); both total hip and lumbar spine BMD decreased by 9.27% (n = 22; P < .001) and 4.53% (n = 31; P < .001), respectively. By the second postoperative year, BMD in the total forearm had decreased an additional 3.62% (n = 14; P<.001), whereas radius BMD remained unchanged. Although total hip and lumbar spine BMD significantly decreased at 1 year, by year 2 both total hip and lumbar spine BMD only slightly decreased and were not significantly different from before the operation. Serum calcium decreased from 9.8 mg/dL to 9.2 during the first year (not significant [NS]) and then to 8.8 (NS) by the second year. Parathyroid hormone increased from 59.7 pg/mL (nl 10-65 pg/mL) preoperatively to 63.1 during year 1 (NS) and continued to increase to 64.7 by year 2 (NS). No difference was noted among levels of 25-hydroxy vitamin D preoperatively (25.2 ng/mL; nl 10-65 ng/mL), at 1 year (34.4), and at 2 years (35.4). Our data indicate that bone loss is highest in the first year after gastric bypass with stabilization, and that, in some cases, there is an increase in bone density after the first year. Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18, 2005 (oral presentation).     

术中射频消融后病灶刮除治疗脊柱转移瘤

目的:探讨术中射频消融(RFA)后再行病灶刮除术治疗脊柱转移瘤的可行性及疗效.方法:2004年～2006年,对11例脊柱转移瘤患者术中实施RFA后再行病灶刮除术,将FRA前后病灶标本进行光镜和电镜病理检查,随访患者疼痛缓解情况及肿瘤复发情况.结果:术中未出现脊髓和神经根损伤,RFA后瘤组织固缩,刮除顺利,出血量350～3800ml,平均1024.5ml.全部病例得到6个月以上随访,平均9.8个月,全部患者生存期超过6个月,VAS评分术前平均5.8分,术后6个月时平均1.9分.1例出现局部肿瘤复发.RFA前的标本光、电镜检查均未见肿瘤组织坏死.RFA后光镜检查3例无明显坏死,9例肿瘤细胞完全坏死:电镜检查10例肿瘤细胞完全坏死,1例肿瘤细胞部分坏死,1例无明显坏死.结论:术中RFA后再行病灶刮除治疗脊柱转移瘤安全可行,有利于肿瘤的刮除,减少局部复发的风险.     

手法复位石膏外固定治疗Barton骨折

Barton骨折是桡骨远端背侧、掌侧缘骨折,合并腕的半脱位,是一种较少见的关节内骨折。自1998年以来对21例Barton骨折患者采用闭合手法整复、石膏夹板外固定治疗,经随访观察,疗效满意。     

RF refocused echoes of J-coupled spin systems: effects on RARE-based spectroscopic imaging.

A numerical simulation tool was developed to calculate the echo amplitudes of J-coupled resonances within a series of radiofrequency (RF) refocused echoes. The signal modulation due to J-coupling in rapid acquisition with relaxation enhancement (RARE) is suppressed only when the inverse of the pulse interval (tau) is large compared to both the chemical shift (CS) difference (Deltadelta) of the coupled spins and the coupling constant. In contrast, the echo amplitudes in ultrafast low-flip-angle RARE (U-FLARE) oscillate around a quasi-steady-state value that is greater than zero (neglecting relaxation and diffusion) even when Deltadelta > 1/tau. The flip-angle distribution over the measured slice caused by the use of Gaussian-shape slice-selective refocusing pulses further reduces the echo oscillations. When the pulse interval falls short of the fast pulse rate regime, spectroscopic U-FLARE provides an improved spatial impulse response in the phase-encoding (PE) direction compared to spectroscopic RARE.     

Electrophysiological study on differentiation of rat bone marrow stromal stem cells into neuron-like cells in vitro by edaravone

To explore the electrophysiological proper-ties of differentiation of rat bone marrow-derived stromal stem cells (rBMSCs) to neuron-like cells in vitro by edaravone, a new type of free radical scavenger. Methods: Stromal stem cells were separated from rat bone marrow with Ficoll-Paque reagent and expanded in different culture medium in vitro, rBMSCs were induced by edaravone containing serum-free L-DMEM. Morphologic observation and Western blot analysis including the ex-pression of Nav1.6, Kv1.2, Kv1.3, Cav1.2 were performed, and whole patch-clamp technique was used. Results: Cyton contraction and long processes were shown in differentiated stromal stem cells. Nav1.6, Kv1.2, Kv1.3 and Cav1.2 were expressed in both differentiated and undifferentiated cells. However, the expression of channel proteins in differentiated cells was up-regulated. Consistently, their resting potential and outward currents were also enhanced in the differentiated cells, which was especially significant in the outward rectifier potassium current. Conclusion: In vitro, neuron-like cells derived from rBMSCs, induced by edaravone, possess electrophysiologi-cal properties of neurons.     

Comparison of Marker Intervals and Number of Sib Pairs Used for Linkage Analysis on Simulated Nuclear Family Data

Using a two‐stage global scan design, we analyzed general population replicates 1 and 42 of the Genetic Analysis Workshop (GAW) 12 simulated data set using three methods: revisited Haseman‐Elston (HER), maximum likelihood variance estimation (ML), and variance components (VC). Three marker densities, 5‐, 10‐, and 15‐cM intervals, were examined in the first‐stage scan. We found that the 10‐cM interval appears to be the most cost‐effective approach in genotyping without sacrificing power when using a first stage significance level of 0.01. Subsequently, we performed the second‐stage scan at 1‐cM intervals for those putative positive regions identified in the first‐stage scan at a significance level of 0.01. We also compared the power to detect linkage using different numbers of sib pairs for a genome‐wide scan at a 10‐cM interval and found that power decreases nonlinearly as the number of sib pairs decreases. © 2001 Wiley‐Liss, Inc.     

First clinical experiences with an implantable bone conduction hearing aid at the University of Amsterdam

Summary A transcutaneous bone-conduction hearing aid was implanted in 11 patients who were not suitable for transcranial sound amplification. Audiological and surgical selection criteria were followed strictly. One device had to be explanted and minor revision surgery was needed in two cases for skin irritation and scarring. In general the aids were well tolerated but the amplification power of the external device proved to be insufficient in some patients, in whom bone conduction levels were on the borderline of the selection limits. Correspondence to: W.A. Dreschler     

Fiberglass or silica exposure and increased nephritis or ESRD (end-stage renal disease)

The U.S. multiplant cohort mortality study of workers producing manufactured mineral fibers is finding increasing mortality from nephritis and/or nephrosis. We examine other data sets to see if similar effects can be identified. In a case-referent study among Michigan patients with end-stage renal disease (ESRD), men with exposures to silica have elevated odds ratio for ESRD. In a California occupational mortality study based on 1979–81 data, a number of the construction trades, farmers, and farm laborers show excess mortality for renal disease. The highest mortality ratio is found in the category including insulation workers. This ratio remains significantly elevated when adjusted for estimated exposures to smoking, alcohol, and for socio-economic status. California mortality data from 20 years earlier (1959–61) fail to show much excess renal disease in construction workers, but do for farmers. In Singapore, granite workers with a long-term exposure to silica have excess excretion of albumin and similar compounds compared to less exposed controls, leading to the presumption that silica exposure can lead to silica nephrotoxicity. Balkan nephropathy has been associated with consumption of well water high in silica. In the Negev of Israel, dust storms are a vehicle for increasing respiratory uptake of silica. The Beduin, thought to be a population with maximal exposures, have higher rates of ESRD than do Jews in the age groups over 60 years. Although high blood concentrations of silica are found in persons with renal failure, the close association with elevated creatinine has been interpreted as evidence that the buildup of silica is due to renal failure, rather than vice-versa. The evidence is consistent with, but not yet compelling, that exposure to silica, which can be readily absorbed (or dissolved) from the lung, may increase the long-term risk of renal disease including renal failure. © 1993 Wiley-Liss, Inc.     

Bone marrow fat content in relation to bone remodeling and serum chemistry in intact and ovariectomized dogs

Summary It was previously shown that 11 months after ovariectomy the volume fraction of trabecular bone in the spine and 11th rib medullary canal of Beagle dogs (6 control, 9 ovariectomized) was significantly reduced. In this paper it is shown that these changes are accompanied by increased marrow fat volume in the 11th rib (59.0±9.5% vs. 44.3 ±10.0%). Conversely, the volume fraction of functional (hematopoietic) cells in the marrow was reduced by ovariectomy. Additionally, variations in marrow fat volume were tested for correlation with 22 other variables pertinent to bone physiology. Marrow fat volume was significantly positively correlated with serum osteocalcin, rib trabecular bone porosity, rib cross-sectional area, and gains in body weight. It was negatively correlated with serum estrogen concentrations and the extent of rib trabecular surfaces labeled with tetracycline.