Decellularization of precision-cut kidney slices-application of physical and chemical methods

The extracellular matrix (ECM) obtained by decellularization provides scaffolds with the natural complex architecture and biochemical composition of the target organ. Whole kidney decellularization by perfusion uses the vasculature to remove cells leaving a scaffold that can be recellularized with patient-specific cells. However, decellularization and recellularization are highly complex processes that require intensive optimization of various parameters. In pursuit of this, a huge number of animals must be sacrificed. Therefore, we used precision-cut kidney slices (PCKS) as a source of natural scaffolds, which were decellularized by immersion in chemical reagents allowing the examination of more parameters with less animals. However, chemical reagents have a damaging effect on the structure and components of the ECM. Therefore, this study aimed at investigating the effects of physical treatment methods on the effectiveness of PCKS decellularization by immersion in chemical reagents (CHEM). PCKS were treated physically before or during immersion in chemicals (CHEM) with high hydrostatic pressure (HHP), freezing-thawing cycles (FTC) or in an ultrasonic bath system (UBS). Biochemical and DNA quantification as well as structural evaluation with conventional histology and scanning electron microscopy (SEM) were performed. Compared to decellularization by CHEM alone, FTC treatment prior to CHEM was the most effective in reducing DNA while also preserving glycosaminoglycan (GAG) content. Moreover, while UBS resulted in a comparable reduction of DNA, it was the least effective in retaining GAGs. In contrast, despite the pretreatment with HHP with pressures up to 200 MPa, it was the least effective in DNA removal. Histological scoring showed that HHP scaffolds received the best score followed by UBS, FTC and CHEM scaffolds. However further analysis with SEM demonstrated a higher deterioration of the ultrastructure in UBS scaffolds. Altogether, pretreatment with FTC prior to CHEM resulted in a better balance between DNA removal and structural preservation.

Comparison of Loading Doses of Ziv-Aflibercept and Aflibercept in Neovascular Age-Related Macular Degeneration

PURPOSE

The aim of this study was to compare outcomes of 3 loading doses of ziv-aflibercept and aflibercept in treatment-naïve neovascular age-related macular degeneration (nAMD).

DESIGN

Retrospective, nonrandomized, comparative study.

METHODS

This was a retrospective chart review which included cases with treatment-naïve nAMD. The patients were divided into 2 groups (group 1, ziv-aflibercept; group 2, aflibercept). Groups 1 and 2 received 1.25 mg/0.05 mL of intravitreal ziv-aflibercept and 2 mg/0.05 mL aflibercept, respectively every month for 3 months. Best-corrected visual acuity (BCVA) in Snellen and logarithm of minimum angle of resolution (logMAR), central subfoveal thickness (CSFT), subretinal hyperreflective material height, neurosensory detachment height, and pigment epithelial detachment height were recorded at baseline and 3 monthly follow-up.

RESULTS

Twenty-three eyes of 23 patients were included (males 14, females 9). Twelve and 11 eyes were included in group 1 and group 2, respectively. Group 1 showed statistically significant improvement in BCVA (P < 0.001) and CSFT (P=0.007) through 3 months compared with baseline. There was significant change in BCVA from baseline at 1st month (P = 0.007), 2nd month (P = 0.002) and 3rd month (P = 0.008). In group 2, there was no significant improvement in BCVA, CSFT, subretinal hyperreflective material height, neurosensory detachment, and pigment epithelial detachment height from baseline through 3 months.

CONCLUSIONS

After 3 loading doses, ziv-aflibercept showed efficacy in terms of improved BCVA and reduction of CSFT from baseline whereas aflibercept did not show such improvement. Considering the cost- effectiveness and the proven safety of ziv-aflibercept, it is a viable option for the crucial, initial 3 doses in the treatment of nAMD.

"Jampolsky Syndrome": superior rectus overaction-contracture syndrome: prevalence, characteristics, etiology and management

BACKGROUND AND PURPOSE

To further describe the Superior Rectus Overaction/Contracture Syndrome (SRSy) first described by Jampolsky in 1964.

METHODS OF STUDY

Twenty-five patients demonstrating findings characteristic of an isolated SRSy of various etiologies, but unrelated to superior oblique palsy or dissociated vertical deviation DVD, are reported. Eleven patients had surgery, consisting of superior rectus (SR) recession in ten patients and a Knapp procedure to the fellow eye (with presumed diagnosis of double elevator palsy) in one patient.

RESULTS

Of the 10 patients who had SR recession of the affected eye, 9 were satisfactorily alleviated of their vertical deviation with elimination of the forced tilt difference, whereas one patient developed the SRSy in the fellow eye soon after surgery. The patient who had the Knapp procedure to the fellow eye showed, one week postoperatively, full sursumduction of that eye with significant bilateral DVD.

CONCLUSION

SRSy is a common syndrome of several various etiologies. Not infrequently, whether or not associated with DVD, it may masquerade as weakness of the contralateral inferior oblique and/or superior rectus muscles. The treatment of choice is weakening of the overacting contracted SR muscle.

Ethmoid sinus osteoma presenting as epiphora and orbital cellulitis: case report and literature review

Paranasal sinus osteoma is a slow-growing, benign, encapsulated bony tumor that may be commonly asymptomatic, being detected incidentally in 1% of plain sinus radiographs or in 3% of sinus computerized tomographic scans. In a patient presenting with orbital cellulitis and epiphora, computed tomography disclosed a large osteoma of the ethmoid sinus. Excision of the osteoma allowed recovery of vision, return of extraocular muscle function, and resolution of choroidal folds. Proptosis, diplopia, and visual loss are other frequent presenting signs of paranasal osteomas. Epidemiology, diagnosis, treatment, and pathologic findings in paranasal sinus osteoma are reviewed.