Evaluation of 18 F-fluorodeoxyglucose positron emission tomography and computed tomography with histopathologic correlation in the initial staging of head and neck cancer

OBJECTIVE: To prospectively evaluate the use of 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET) in the initial staging of squamous cell head and neck carcinoma. SUMMARY BACKGROUND DATA: The status of cervical lymph nodes is an important prognostic factor and determinant of management approach in squamous cell head and neck cancer. METHODS: FDG-PET findings were compared with those of computed tomography (CT) before removal of the primary tumor and/or neck dissection. Histopathologic analysis was used as the gold standard for assessment of the sensitivity and specificity of these modalities. RESULTS: FDG-PET correctly identified the primary tumor in 35 of 40 patients in whom the site of the primary was known clinically and still present (sensitivity 88%). None of four unknown primaries were detected. Tumors not detected by FDG-PET were generally superficial, with depths of less than 4 mm. CT correctly identified 18 of the 35 primary tumors (sensitivity 51%). Eleven of 17 CT false-negative tumors were detected by FDG-PET. The sensitivity and specificity for the presence of metastatic neck disease on FDG-PET were 82% and 100%, respectively; those for CT were 81% and 81%, respectively. FDG-PET was true positive for metastatic neck disease in two of the three CT false-negative patients. CONCLUSIONS: FDG-PET shows promise in the initial staging of head and neck cancer and provides additional accuracy to a conventional staging process using CT.     

Bone microstructure at the distal tibia provides a strength advantage to males in late puberty: An HR‐pQCT study

Bone is a complex structure with many levels of organization. Advanced imaging tools such as high‐resolution (HR) peripheral quantitative computed tomography (pQCT) provide the opportunity to investigate how components of bone microstructure differ between the sexes and across developmental periods. The aim of this study was to quantify the age‐ and sex‐related differences in bone microstructure and bone strength in adolescent males and females. We used HR‐pQCT (XtremeCT, Scanco Medical, Geneva, Switzerland) to assess total bone area (ToA), total bone density (ToD), trabecular bone density (TrD), cortical bone density (CoD), cortical thickness (Cort.Th), trabecular bone volume (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular spacing standard deviation (Tb.Sp SD), and bone strength index (BSI, mg²/mm⁴) at the distal tibia in 133 females and 146 males (15 to 20 years of age). We used a general linear model to determine differences by age‐ and sex‐group and age × sex interactions (p < 0.05). Across age categories, ToD, CoD, Cort.Th, and BSI were significantly lower at 15 and 16 years compared with 17 to 18 and 19 to 20 years in males and females. There were no differences in ToA, TrD, and BV/TV across age for either sex. Between sexes, males had significantly greater ToA, TrD, Cort.Th, BV/TV, Tb.N, and BSI compared with females; CoD and Tb.Sp SD were significantly greater for females in every age category. Males' larger and denser bones confer a bone‐strength advantage from a young age compared with females. These structural differences could represent bones that are less able to withstand loads in compression in females. © 2010 American Society for Bone and Mineral Research     

In Vivo Anergized T Cells Form Altered Immunological Synapses In Vitro

T cells contact allogeneic antigen presenting cells (APCs) and assemble, at their contact interface, a molecular platform called the immunological synapse. Synapse-based molecules provide directional signals for the T cell--either positive signals, resulting in T-cell activation, or negative signals causing T-cell inactivation or anergy. To better understand the molecular basis of in vivo T-cell anergy we analyzed the contacts made between in vivo anergized T cells and APCs, and determined which signaling molecules were included or excluded from their immunological synapses. Anergy was induced in TCR transgenic mice by the intravenous injection of semiallogeneic donor spleen cells. T cells from anergized mice were mixed with APCs, the T-cell/APC synapses imaged using deconvolution microscopy, and their molecular compositions were determined. T cells from anergic mice formed unstable immunological synapses in vitro with allogeneic APCs and failed to recruit the signaling proteins necessary to initiate T-cell activation. These findings suggest that T-cell anergy induced by exposure to semiallogeneic donor cells is associated with defects in the earliest events of T-cell activation, immunological synapse formation and recruitment of TCR-mediated signaling proteins.     

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目的 报告成功实施腹腔镜迷你胃旁路术治疗单纯性肥胖并2型糖尿病病人1例。方法 第二军医大学附属长海医院微创外科于2007年11月对1例伴有2型糖尿病的单纯性肥胖症病人行腹腔镜迷你胃旁路术。结果 病人手术顺利，手术时间135min，术中出血20mL。术后30d内无手术并发症，随访30d，体重下降15kg，体重指数（BMI）减少4．9。术后第8天停用一切降糖药物，各项糖尿病检查指标均正常。结论 腹腔镜迷你胃旁路术是相对安全、简单的术式，近期减重效果良好，对2型糖尿病具有很好的治疗效果。     

Limited role for IVUS in the endovascular repair of aortoiliac aneurysms.

BACKGROUND: To determine the need for routine versus selective intraoperative IVUS during endovascular aortoiliac aneurysm (AIA) repair. METHODS: One-hundred and eighty-eight endovascular AIA repairs performed over a 5-year period were reviewed and included in the study. Surgeon-made aorto-uni-femoral grafts (n=78) and industry-made bifurcated or tube grafts (n=110) were used. In the initial 51 cases IVUS was routinely performed. In the latter 137 cases IVUS was used selectively. In this group graft deformities suspected on completion angiography or pullback pressure measurements were treated with balloon dilatation and stenting. IVUS was then performed only in the presence of a persistent pressure gradient or inconclusive angiographic findings. RESULTS: In the initial 51 cases IVUS revealed 20 lesions of which 8 were not initially detected angiographically and which required further treatment. In the latter 137 cases IVUS was necessary in only 1 case, and guided the treatment of an angiographically undetectable lesion. There have been no late episodes of graft compression, kinking, or thrombosis in the selective IVUS group. CONCLUSIONS: The use of pullback pressure measurements with a low threshold for angioplasty and stenting, especially in unsupported grafts, followed by the selective use of IVUS decreases the overall requirement for IVUS and its associated costs.     

Increasing incidence of midterm and long-term complications after endovascular graft repair of abdominal aortic aneurysms: a note of caution based on a 9-year experience

OBJECTIVE: To analyze the late complications after endovascular graft repair of elective abdominal aortic aneurysms (AAAs) at the authors' institution since November 1992. SUMMARY BACKGROUND DATA: Recently, the use of endovascular grafts for the treatment of AAAs has increased dramatically. However, there is little midterm or long-term proof of their efficacy. METHODS: During the past 9 years, 239 endovascular graft repairs were performed for nonruptured AAAs, many (86%) in high-risk patients or in those with complex anatomy. The grafts used were Montefiore (n = 97), Ancure/EVT (n = 14), Vanguard (n = 16), Talent (n = 47), Excluder (n = 20), AneuRx (n = 29), and Zenith (n = 16). All but the AneuRx and Ancure repairs were performed as part of a U.S. phase 1 or phase 2 clinical trial under a Food and Drug Administration investigational device exemption. Procedural outcomes and follow-up results were prospectively recorded. RESULTS: The major complication and death rates within 30 days of endovascular graft repair were 17.6% and 8.5%, respectively. The technical success rate with complete AAA exclusion was 88.7%. During follow-up to 75 months (mean +/- standard deviation, 15.7 +/- 6.3 months), 53 patients (22%) died of unrelated causes. Two AAAs treated with endovascular grafts ruptured and were surgically repaired, with one death. Other late complications included type 1 endoleak (n = 7), aortoduodenal fistula (n = 2), graft thrombosis/stenosis (n = 7), limb separation or fabric tear with a subsequent type 3 endoleak (n = 1), and a persistent type 2 endoleak (n = 13). Secondary intervention or surgery was required in 23 patients (10%). These included deployment of a second graft (n = 4), open AAA repair (n = 5), coil embolization (n = 6), extraanatomic bypass (n = 4), and stent placement (n = 3). CONCLUSION: With longer follow-up, complications occurred with increasing frequency. Although most could be managed with some form of endovascular reintervention, some complications resulted in a high death rate. Although endovascular graft repair is less invasive and sometimes effective in the long term, it is often not a definitive procedure. These findings mandate long-term surveillance and prospective studies to prove the effectiveness of endovascular graft repair.     

Enhanced accumulation of A2E in individuals homozygous or heterozygous for mutations in BEST1 (VMD2)

Best vitelliform macular dystrophy (BMD) is an autosomal dominant inherited macular degenerative disease caused by mutations in the gene BEST1 (formerly VMD2). Prior reports indicate that BMD is characterized histopathologically by accumulation of lipofuscin in the retinal pigment epithelium (RPE). However, this accumulation has not been quantified and the chemical composition of lipofuscin in BMD has not been examined. In this study we characterize the histopathology of a donor eye from a rare individual homozygous for a mutation (W93C) in BEST1. We find that this individual's disease was not any more severe than has been described for heterozygotes. We then used this tissue to quantify lipofuscin accumulation by enriching intracellular granules from RPE cells on sucrose gradients and counting the granules in each density fraction. Granules from the homozygous donor eye as well as a donor eye from an individual heterozygous for the mutation T6R were compared with age-matched control eyes. Interestingly, the least dense fraction, representing classical lipofuscin granules was either not present or significantly diminished in the BMD donor eyes and the autoflourescence associated with lipofuscin had shifted to denser fractions. However, a substantial enrichment for granules in fractions of higher density was also noted in the BMD samples. Inspection of granules from the homozygous donor eye by electron microscopy revealed a complex abnormal multilobular structure. Analysis of granules by HPLC indicated a approximately 1.6- and approximately fourfold overall increase in A2E in the BMD eyes versus age-matched control eyes, with a shift of A2E to more dense granules in the BMD donor eyes. Despite the increase in A2E and total intracellular granules, the RPE in the homozygous donor eyes was relatively well preserved. Based on these data we conclude that the clinical and histopathologic consequences to the homozygous donor were not any more severe than has been reported previously for individuals who are established or presumptive heterozygotes. We find that A2E is a component of the lipofuscin accumulated in BMD and that it is more abundant than in control eyes suggesting that the etiology of BMD is similar to Stargardt's disease and Stargardt-like macular dystrophy. Finally, the changes we observe in the granules suggest that the histopathology and eventual vision loss associated with BMD may be due to defects in the ability of the RPE to fully degrade phagocytosed photoreceptor outer segments.