Amniotic fluid as a rich source of mesenchymal stromal cells for transplantation therapy

Stem cells isolated from amniotic fluid are known to be able to differentiate into different cells types, thus being considered as a powerful tool for cellular therapy of different human diseases. In the last 4 years, amniotic fluid-derived stem (AFS) cells have been shown to express embryonic and adult stem cell markers. These cells can be considered an intermediate stage between embryonic stem cells and adult stem cells. AFS cells can give rise to adipogenic, osteogenic, myogenic, endothelial, neurogenic, and hepatic lineages, inclusive of all embryonic germ layers. AFS cells have a high renewal capacity and can be expanded for over 250 doublings without any detectable loss of chromosomal telomere length. Taken together, all these data provide evidence that amniotic fluid represents a new and very promising source of stem cells for research, as well as clinical applications. Certainly stem cells from amniotic fluid will be useful both for a customized cell supply for newly born children and for banking cells to be used for therapeutic cell transplantation in immunogically matched recipients. Further investigations are also warranted to fully explore the amniotic cells' potential for adult human disorders.     

Improvement of bone mineral density and markers of proximal renal tubular function in chronic hepatitis B patients switched from tenofovir disoproxil fumarate to tenofovir alafenamide

Tenofovir alafenamide (TAF) is a novel prodrug that reduces tenofovir plasma levels by 90% compared to tenofovir disoproxil fumarate (TDF), resulting in decreased bone mineral density (BMD) loss and renal toxicity. We aimed to study changes in BMD and markers of renal function of chronic hepatitis B (CHB) patients previously treated with TDF who were switched to TAF in as early as 12 weeks. This was a prospective single‐arm open‐label study of 75 CHB patients treated with TDF 300 mg daily who were switched to TAF 25 mg daily and followed for 24 weeks. All patients had been treated with TDF for at least 12 months and had HBV DNA <21 IU/mL at the time of switch. BMD and markers of renal function were taken on the day of switch and repeated after 12 and 24 weeks of TAF treatment. Hip and spine bone mineral density significantly increased from baseline to week 12 (+12.9% and +2.4%, respectively, P < 0.01). There were significant decreases in urinary beta‐2‐microglobulin to creatinine and retinol‐binding protein to creatinine ratios by week 12 (P < 0.01 for both). Mean estimated glomerular filtration rate (GFR) did not change. Tubular reabsorption of phosphate was decreased at week 24 (P < 0.05). In conclusion, CHB patients previously treated with TDF experienced significant improvement in bone density and some markers of renal tubular function and as early as 12 weeks after switching to TAF. Bone density changes associated with TDF may not be entirely related to renal handling of phosphate.     

Gadoxetate disodium-enhanced MR imaging: differentiation between early-enhancing non-tumorous lesions and hypervascular hepatocellular carcinomas

Purpose

To retrospectively assess imaging features that help differentiate early-enhancing non-tumorous (EN) hepatic lesions from hepatocellular carcinomas (HCCs) on gadoxetate disodium-enhanced MR imaging.

Materials and methods

Our institutional review board approved this retrospective study. We reviewed the studies of 158 patients (92 men and 65 women; age range: 29-91; mean age: 65.6 years) with chronic liver damage, who underwent gadoxetate disodium-enhanced MR imaging at 3T MR scanner. Hypervascular lesions identified during the hepatic artery phase were selected for a study cohort. The location, shape, size (maximum diameter and maximum area), and contrast enhancement signal intensity characteristics of the lesions were evaluated, then compared between the EN and HCC lesions.

Results

A total of 65 EN lesions (range: 3-60 mm, mean: 13.6 ± 10.6 mm) from 35 patients and 33 HCCs (range: 9-61 mm, mean: 19.3 ± 12.6 mm) from 20 patients were identified. Lesions were more frequently round or oval in shape for HCCs (n = 29; 88%) than ENs (n = 26; 40%) (P < 0.01). Unexpectedly, some ENs (n = 12; 18%) showed hypointensity on hepatocyte-phase, and 6 (50%) of them were T2 hyperintense. For lesions smaller than 2 cm (9 ENs and 21 HCCs) on hepatic arterial-phase images, the mean area of hypointensity in hepatocyte-phase (54.2 ± 33.1 mm²) was significantly smaller than those of the corresponding hyperintensity in hepatic arterial-phase (97.1 ± 42.0 mm²) for EN lesions (P = 0.019), whereas no significant difference in area was found for HCCs.

Conclusion

EN lesions may occasionally present with hypointensity during the hepatocyte-phase; presenting a diagnostic dilemma. In this situation, EN lesions may be differentiated from HCCs when a hypointense area in hepatocyte-phase is smaller than the corresponding hypervascular area in hepatic-arterial phase.     

Orbital floor reconstruction considering orbital floor slope

Orbital floor fractures are among the more challenging injuries faced by plastic surgeons. Enophthalmos is defined as backward, usually downward, displacement of the globe into the bony orbit. We describe reconstruction of the orbital floor slope in orbital floor fractures that prevents postoperative complications, especially posttraumatic enophthalmos. Thirty-three patients with orbital floor fractures were treated using reconstruction of the orbital floor slope between April 2009 and July 2010. The patients ranged in age from 12 to 54 years. There were 31 males and 2 females. All patients were operated on using a transconjunctival approach under general anesthesia. The orbital floor was reconstructed with poly-l/d-lactide sheets in all cases. Preoperatively, 23 [Float1]patients (69%) had enophthalmos, and 12 patients (36%) had symptomatic diplopia. The enophthalmos was corrected in 20 patients (86%), and the diplopia resolved in 10 (83%). Extrinsic ocular movement was impaired preoperatively in 1 patient (3%), but resolved after surgery. No patient had impaired visual acuity preoperatively or postoperatively. The results suggest that orbital floor reconstruction considering the orbital floor slope is a safe, reliable method with fewer complications that is more effective at preventing posttraumatic enophthalmos.     

Comparative study of the postoperative complications of microvascular surgery in elderly and young patients

Free flap reconstruction of complex defects has revolutionized cancer and trauma treatment and offers a reliable and efficient method for reconstructing tissue defects. We analyzed the donor, flap, and systemic complications in an aging group and in a group of younger patients to identify whether age is an important factor in complication rates. This study was a retrospective review of the medical records of 43 consecutive patients who underwent free flap reconstructions. Patients were divided into two groups according to age (group A: younger than 60 years, group B: 60 years or older). We analyzed the free flap types and donor site, flap, and postoperative systemic complications. Statistical analyses were performed to determine the influence of age on complication rate. Donor site complications developed in three cases in group A and in three cases in group B. Flap complications occurred in 17 cases in group A and in 5 cases in group B. Systemic complications occurred in two cases in group A and in five cases in group B. Age did not have a statistically significant impact on free flap complications, and old age was not a risk factor for free flap surgery.