后巩膜加固术在高度近视性黄斑病变手术中的应用

近视性黄斑病变致盲率高,常用治疗手段为玻璃体切割术,然而单纯玻璃体切割术对于已出现严重后巩膜葡萄肿的超高度近视患者疗效欠佳。近年来临床应用玻璃体切割术联合后巩膜加固术治疗高度近视继发眼底病变,特别在黄斑劈裂及黄斑裂孔病例中,疗效肯定,前景可期。我们针对近年来后巩膜加固术的材料与术式变迁作一全面综述,并进一步讨论其应用于眼底手术中的发展远景。     

Treatment of early cut-out of a lag screw using a trochanter supporting plate: 11 consecutive patients with unstable intertrochanteric fractures

Introduction Superior cut-out of a lag screw remains a serious complication in the treatment of intertrochanteric fractures. It is related to the stability of fracture reduction. We describe the application of a trochanter supporting plate (TSP) to restore the fracture stability after early cut-out of a lag screw in unstable intertrochanteric fractures.Materials and methods A total of 11 consecutive patients with superior cut-out of the lag screw of a dynamic hip screw (DHS) or a gamma nail in an unstable intertrochanteric fracture occurring within 6 months after surgery were included in the present study. They underwent repeat surgery for placement of a DHS and a laterally mounted TSP of our design. All patients were monitored for at least 6 months (median 15 months; range 6–28 months).Results There was no repeated cut-out of a lag screw, and 10 patients (91%) achieved bony union within 5 months. At the last follow-up, all patients could walk with or without aids.Conclusion It reveals that a TSP, as an adjuvant to a lag screw placed inferiorly, is an easy and safe solution for the treatment of early cut-out of a lag screw in unstable intertrochanteric fractures.     

Oral bisphosphonate use in the elderly is not associated with acute kidney injury

Intravenous bisphosphonates can cause acute kidney injury; however, this risk was not found with oral bisphosphonates in randomized clinical trials with restrictive eligibility criteria. In order to provide complementary safety data, we studied the risk of acute kidney injury in a population-based cohort of 122,727 patients aged 66 years and older discharged from hospital following a new fragility fracture and no history of bisphosphonate use in the prior year. Bisphosphonate treatment was identified within 120 days after discharge and event rates were measured from 90 days of therapy initiation. The primary outcome was hospitalization with acute kidney injury with secondary outcomes of new nephrology consultation and, in a subset of patients with laboratory values, acute kidney injury was defined as an increase in serum creatinine. We identified 18,286 bisphosphonate users and 104,441 non-users with a mean age of 81 years. Of 5772 patients with laboratory values, 40% had chronic kidney disease (eGFR <60?ml/min per 1.73?m(2)). Overall, there was no statistically significant difference in the risk of acute kidney injury among bisphosphonate users compared to non-users (adjusted odds ratio 1.03), and no significant differences in other outcomes or in subgroups of patients with baseline chronic kidney disease. Thus, in this older population-based cohort, oral bisphosphonate use was not associated with acute kidney injury.     

Scale‐up of MSC under hypoxic conditions for allogeneic transplantation and enhancing bony regeneration in a rabbit calvarial defect model

To realize the therapeutic potential of mesenchymal stem cells (MSCs), we aimed to develop a method for isolating and expanding New Zealand rabbit MSCs in a great scale. Rabbit MSCs expanded under hypoxic and normoxic conditions were compared in terms of replication capacity, differentiation potential, and the capacity for allogeneic transplantation in a calvarial defect model. The cells from all tested rabbits were expanded more rapidly when plated at low‐density under hypoxic conditions compared to under normoxic conditions. Moreover, cells expanded under hypoxic conditions increased in the potential of osteoblastic, adipocytic, and chondrocytic differentiation. More importantly, radiographic analysis and micro‐CT measurement of bone volume revealed the hypoxic cells when transplanted in the calvarial defects of another rabbit increased in the ability to repair bone defect compared to the normoxic cells. Six weeks after allogeneic transplantation of hypoxic MSCs, histological analysis revealed a callus spanned the length of the defect, and several bone tissues spotted in the implant. At 12 weeks, new bone had formed throughout the implant. Using BrdU labeling to track the transplanted cells, the hypoxic cells were more detected in the newly formed bone compared to the normoxic cells. For defects treated with allogeneic MSCs, no adverse host response could be detected at any time‐point. In conclusion, we have developed a robust method for isolation and expansion of rabbit MSCs by combining low‐density with hypoxic culture, which can be applied for the design of clinical trials in allogeneic transplantation of MSCs for bone healing. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1213–1220, 2012     

[18F]Fluciclatide in the in vivo evaluation of human melanoma and renal tumors expressing αvβ3 and αvβ5 integrins

Purpose

[¹⁸F]Fluciclatide is an integrin-targeted PET radiopharmaceutical. α_vβ₃ and α_vβ₅ are upregulated in tumor angiogenesis as well as on some tumor cell surfaces. Our aim was to use [¹⁸F]fluciclatide (formerly known as [¹⁸F]AH111585) for PET imaging of angiogenesis in melanoma and renal tumors and compare with tumor integrin expression.

Methods

Eighteen evaluable patients with solid tumors ≥2.0 cm underwent [¹⁸F]fluciclatide PET/CT. All patients underwent surgery and tumor tissue samples were obtained. Immunohistochemical (IHC) staining with mouse monoclonal antibodies and diaminobenzidine (DAB) was applied to snap-frozen tumor specimens, and additional IHC was done on formalin-fixed paraffin-embedded samples. DAB optical density (OD) data from digitized whole-tissue sections were compared with PET SUV_{80% max}, and Patlak influx rate constant (K _i) data, tumor by tumor.

Results

Tumors from all 18 patients demonstrated measurable [¹⁸F]fluciclatide uptake. At the final dynamic time-point (55 min after injection), renal malignancies (in 11 patients) demonstrated an average SUV_{80% max} of 6.4?±?2.0 (range 3.8 – 10.0), while the average SUV_{80% max} for metastatic melanoma lesions (in 6 patients) was 3.0?±?2.0 (range 0.7 – 6.5). There was a statistically significant difference in [¹⁸F]fluciclatide uptake between chromophobe and nonchromophobe renal cell carcinoma (RCCs, with SUV_{80% max} of 8.2?±?1.8 and 5.4?±?1.4 (P?=?0.020) and tumor-to-normal kidney (T/N) ratios of 1.5?±?0.4 and 0.9?±?0.2, respectively (P?=?0.029). The highest Pearson's correlation coefficients were obtained when comparing Patlak K _i and α_vβ₅ OD when segregating the patient population between melanoma and RCC (r?=?0.83 for K _i vs. melanoma and r?=?0.91 for K _i vs. RCC). SUV_{80% max} showed a moderate correlation with α_vβ₅ and α_vβ₃ OD.

Conclusion

[¹⁸F]Fluciclatide PET imaging was well tolerated and demonstrated favorable characteristics for imaging α_vβ₃ and α_vβ₅ expression in melanoma and RCC. Higher uptake was observed in chromophobe than in nonchromophobe RCC. [¹⁸F]Fluciclatide may be a useful radiotracer to improve knowledge of integrin expression.     

Restoration of bone defect and enhancement of bone ingrowth using partially demineralized bone matrix and marrow stromal cells

PURPOSE: This study aimed to investigate the capability of combining marrow stromal cells (MSC) and partially demineralized bone matrix (PDBM) to fill bone defect and enhance bone ingrowth using a canine non-weight-bearing gap model. METHODS: Custom-made implants with 3mm gap between the porous surface and the host bone were used. The implants were inserted into the distal femurs of 25 mongrel dogs and the gaps were randomly assigned to be filled with culture-expanded autologous MSC-loaded PDBM, autograft, fresh-frozen allograft, PDBM alone, or nothing as controls. Histomorphometry using backscattered scanning electron microscopic examination, and mechanical push-out test were performed at 6 months after surgery. RESULTS: Histomorphometry showed that amounts of bone regeneration in the gap and bone ingrowth into the porous-coated surface in the MSC-loaded PDBM-treated group were comparable to those of autograft-treated group and were significantly greater than those of allograft-treated, PDBM-treated, or non-grafted groups. Mechanical test showed the same differences. CONCLUSION: The results of this study showed that combining PDBM and autologous culture-expanded MSC restored bone stock and enhanced bone ingrowth into the porous-coated area in a canine non-weight-bearing gap model. This combination may provide an option for reconstructing bone defect when we perform a cementless revision arthroplasty.     

Impact of initial dialysis modality and modality switches on Medicare expenditures of end-stage renal disease patients

BACKGROUND: The number of end-stage renal disease (ESRD) enrollees and Medicare expenditures have increased dramatically. Pathways and associated Medicare expenditures in ESRD treatment need to be examined to potentially improve the efficiency of care. METHODS: This study examines the impact of initial dialysis modality choice and subsequent modality switches on Medicare expenditure in a 3-year period. The Dialysis Morbidity and Mortality Study Wave 2 data by the United States Renal Data System (USRDS) is used along with the USRDS Core CD and USRDS claims data. RESULTS: A total of 3423 incident dialysis patients (approximately equal number of peritoneal dialysis and hemodialysis) were included in the analysis. Unadjusted average annual Medicare expenditure (in 2004 dollars) for peritoneal dialysis as first modality was 53,277 dollars(95% CI 50,626 dollars-55,927 dollars), and 72,189 dollars (95% CI 67,513 dollars-76,865 dollars) for hemodialysis. Compared to "hemodialysis, no switch" subgroup, "peritoneal dialysis, no switch" had a significantly lower annual expenditure (44,111 dollars vs. 72,185 dollars) (P < 0.001). "Peritoneal dialysis, with at least one switch" and "hemodialysis, with at least one switch" had a lower or similar annual expenditure of 66,639 dollars and 72,335 dollars, respectively. After adjusting for patient characteristics, annual Medicare expenditure was still significantly lower for patients with peritoneal dialysis as the initial modality (56,807 dollars vs. 68,253 dollars) (P < 0.001). Similarly, compared to "hemdialysis, no switch" subgroup, "peritoneal dialysis, no switch" and "peritoneal dialysis, with at least one switch" had a significantly lower total expenditure. Further analysis showed that time-to-first switch also independently impacted total expenditure. CONCLUSION: Initial modality choice (peritoneal dialysis or hemodialysis) and subsequent modality switches had significant implications for Medicare expenditure on ESRD treatments.