Multiple sclerosis: serial study of gadolinium-enhanced MR imaging

Thirteen patients with definite multiple sclerosis (MS), studied 16-24 months previously with magnetic resonance (MR) imaging with and without enhancement by intravenously administered gadolinium diethylenetriaminepentaacetic acid (DTPA) dimeglumine, were reexamined with a similar protocol. Assessment of enhancement and clinical activity in both studies revealed that enhancement was observed in 13 of 14 cases in which clinical activity had changed within 4 weeks of the study and thus appeared more sensitive than clinical examination in determining active disease. The 3-minute postinjection, short repetition time image (TR) was the most efficient for depicting enhancement. Enhancing lesions (active plaques) arose from previously hyper- or isointense regions on long TR images. Previously active lesions reverted to areas of iso- or hyperintensity on long TR images. Serial comparison of long TR images in this population reveals a decrease in high-intensity lesions on long TR images in some cases and an increase in others. The findings of high-intensity regions on long TR images and previously enhancing lesions both becoming isointense suggests that transient inflammatory changes with concomitant edema without demyelination and/or with significant remyelination may occur in some MS lesions. MS lesions are dynamic; both active and inactive lesions may show dramatic change on longitudinal MR imaging studies.     

有创与无创序贯通气治疗慢性阻塞性肺病急性加重期临床研究

目的比较有创与无创序贯通气治疗慢性阻塞性肺病急性加重期的疗效。方法所有患者均入住ICU病房,有创通气采用容量型辅助-控制方式（A/C）以后改为同步间歇强制通气＋压力支持方式（SIMV＋PSV）,然后,根据患者的血气情况和耐受程度逐渐下调呼吸机参数,所有患者均同时应用抗感染、平喘、化痰等常规治疗。序贯通气组逐渐下调直至SIMV为10次/分左右,PSV为10cmH2O左右。如果患者无呼吸困难发生,则拔除气管插管,改用无创通气,IPAP在8～18cmH2O,EPAP在3～5cmH2O,根据血气调整呼吸机参数,直至撤机。对照组则继续采用有创通气,下调SIMV和PSV分别在5次/分和5cmH2O水平,撤机观察,如病情稳定超过4h则拔管。观察两组中机械通气的时间、住ICU时间、VAP的发生、病死率以及撤机的成功与失败的例数。结果有创机械通气时间,序贯组为（10±2）d,而对照组为（19±2）d（P〈0.05）,住ICU时间序贯组为（14±3）d,而对照组为（24±6）d（P〈0.05）,发生VAP的例数序贯组为1例,而对照组8例（P〈0.05）。结论序贯通气治疗比对照组的机械通气时间,ICU留住时间,VAP的发生例数减少。     

Scoliosis surgery in neurofibromatosis

Twenty-three patients who were treated by posterior spinal fusion with neurofibromatous scoliosis were reviewed to study the adequacy of spinal fusion, rate of pseudarthrosis, and incidence of complications. Twenty patients achieved a solid fusion with posterior surgery alone. Thirteen patients required one or more posterior augmentation procedures because of progressive deformity. Three patients with dystrophic kyphoscoliosis required an anterior spinal fusion in addition to the posterior fusion to achieve a solid fusion mass. The type of graft material, Harrington instrumentation, and degree of kyphosis or scoliosis had no effect on the rate of pseudarthrosis. Preoperative neuroradiographic evaluation was found to be warranted for all patients with neurofibromatous scoliosis.     

Increased tumor localization and reduced immune response to adenoviral vector formulated with the liposome DDAB/DOPE

We aimed to increase the efficiency of adenoviral vectors by limiting adenoviral spread from the target site and reducing unwanted host immune responses to the vector. We complexed adenoviral vectors with DDAB–DOPE liposomes to form adenovirus–liposomal (AL) complexes. AL complexes were delivered by intratumoral injection in an immunocompetent subcutaneous rat tumor model and the immunogenicity of the AL complexes and the expression efficiency in the tumor and other organs was examined. Animals treated with the AL complexes had significantly lower levels of β-galactosidase expression in systemic tissues compared to animals treated with the naked adenovirus (NA) (P < 0.05). The tumor to non-tumor ratio of β-galactosidase marker expression was significantly higher for the AL complex treated animals. NA induced significantly higher titers of adenoviral-specific antibodies compared to the AL complexes (P < 0.05). The AL complexes provided protection (immunoshielding) to the adenovirus from neutralizing antibody. Forty-seven percent more β-galactosidase expression was detected following intratumoral injection with AL complexes compared to the NA in animals pre-immunized with adenovirus.

Conclusions

Complexing of adenovirus with liposomes provides a simple method to enhance tumor localization of the vector, decrease the immunogenicity of adenovirus, and provide protection of the virus from pre-existing neutralizing antibodies.     

Response to oral β-carotene supplementation in patients with cystic fibrosis: a 16-month follow-up study

The aim of this study was to determine the efficacy of long-term oral β -carotene supplementation for correcting impaired β -carotene status in cystic fibrosis patients. Thirty-five patients (2.3-30.5 years of age) with coefficients of fat absorption of 46-96% (median 88%) received β -carotene 0.5 mg/kg daily and were followed over a 16-month treatment period. Baseline plasma β -carotene concentrations in patients (meanSD, 0.090.06 μ mol/1) were significantly lower than those of age-matched controls (0.860.56 μ mol/1) ( p < 0.0001). Concentrations increased rapidly and reached a plateau at or before 3 weeks that was maintained throughout the study period. Values obtained at 3 weeks (0.890.64 μ mol/1) were significantly higher ( p < 0.0001) than those at baseline and did not differ from controls. Plasma retinol and α -tocopherol concentrations increased during the observation period, but remained within normal ranges. Plasma retinyl palmitate, which was below the detection limit in all but one patient at baseline, did not increase. Thus oral β -carotene supplementation is effective and normalizes β -carotene status of cystic fibrosis patients without evidence of significant side effects. β -Carotene, cystic fibrosis, LDL-cholesterol, oral supplementation, retinol, α-tocopherol     

A randomized controlled study of the use of transscleral diode laser and cryotherapy in the management of rhegmatogenous retinal detachment

PURPOSE: Cryotherapy, the most common modality used to create a chorioretinal adhesion during retinal reattachment surgery, is associated with the dispersion of viable pigment epithelial cells and breakdown of the blood-ocular barrier, which are thought to be causative in a number of postoperative events, including macular pucker, proliferative vitreoretinopathy (PVR), and cystoid macular edema. Transscleral diode laser has been used successfully to create a chorioretinal adhesion in retinal reattachment surgery (diopexy) and experimentally has been shown to cause less pigment dispersion and blood-ocular barrier breakdown than cryotherapy. The authors carried out a prospective randomized study to compare the results and complication rates of transscleral diopexy with those of cryopexy during surgery for rhegmatogenous retinal detachment (RRD). METHODS: Data from 120 patients with recent onset RRD without significant PVR who were suitable for scleral buckling surgery and randomized to treatment using diode laser or cryotherapy were analyzed. The primary outcome measure was reattachment at 6 months with one operation. Secondary outcome measures were pain and swelling on the first postoperative day, cystoid macular edema as assessed angiographically at 6 weeks, and visual acuity, macular epiretinal membrane, and pigment migration under the fovea at 3 months. RESULTS: There was no significant difference between the primary and secondary outcome measures between the two treatment groups, with a primary success rate of 83% in the diode group and 92% in the cryotherapy group. Pain and postoperative swelling on the first postoperative day were equivalent. Cystoid macular edema was angiographically present in 12% in the diode group and 14% in the cryotherapy group. Visual acuity of at least 20/40 was achieved in 54% of patients in both groups. The rate of PVR was 5% in the diode group and 3% in the cryotherapy group. CONCLUSION: In this study of patients with uncomplicated RD without significant preoperative PVR, the experimentally shown benefits of transscleral diode laser did not result in significant improvement in the results of reattachment surgery compared with cryotherapy.     

The results of surgery on macular holes associated with rhegmatogenous retinal detachment

PURPOSE: Macular holes can occur as a secondary phenomenon with or after otherwise successful repair of uncomplicated macula-off rhegmatogenous retinal detachments with peripheral breaks. The purpose of this study was to evaluate the anatomical and visual outcomes of vitrectomy surgery to close the macular holes in these situations. METHODS: A retrospective record review was completed for patients with a retinal detachment with peripheral breaks and a macular hole or those patients developing macular holes within 2 weeks of successful primary external buckling surgery for macula-off retinal detachment. In those patients with a concurrent macular hole and retinal detachment, a primary vitrectomy was carried out to close the macular hole and reattach the retina. In those patients who developed a macular hole after successful primary external buckling surgery, a secondary vitrectomy was then carried out to close the macular hole. RESULTS: The authors reviewed the records of 10 patients. All had a preoperative visual acuity of 20/400 or worse. After surgery, one patient achieved a best-corrected visual acuity of 20/40; six patients achieved a best-corrected visual acuity of 20/80; and three patients achieved a best-corrected visual acuity of 20/120. CONCLUSION: These results suggest that macular hole surgery is worthwhile for these patients and can provide satisfactory results in terms of visual improvement.