[Differential diagnoses of benign eyelid tumors in children and adolescents]. / Differenzialdiagnosen benigner Lidtumoren bei Kindern und Jugendlichen.

BACKGROUND: The clinical diagnosis as well as the treatment approach of periocular tumors in childhood and adolescence can be challenging. Knowledge of the most important differential diagnoses and their clinicopathological correlation is helpful for the treatment approach. OBJECTIVE: The clinical and histological characteristics of various eyelid tumors in childhood and adolescence are presented taking the excision frequencies into consideration. MATERIAL AND METHODS: The frequencies and clinicopathologic correlation of the most important eyelid tumors (n = 485) are presented based on the data of the ophthalmopathology laboratory of the University Eye Hospital Bonn from 1998-2023. RESULTS: The most frequent tumor in childhood and adolescence is chalazion (57.3%), followed by dermoid cysts (16.7%) and molluscum contagiosum (9.6%). Other lesions of childhood and adolescence include pilomatrixoma (2.1%), hemangioma and other vascular malformations (4.7%) and rare differential diagnoses, such as subcutaneous calcifying nodules and xanthogranuloma. Guidance on the approach in different age groups is presented in the form of a decision tree. CONCLUSION: Tumors in children and adolescents are mostly benign, yet there are important indications for excision. A histological examination of any excised tissue in childhood and adolescence is obligatory because unexpected findings are not uncommon and the spectrum of lesions also differs from that in adulthood. Knowledge of the histological picture can be very helpful in the preoperative clinical classification and for planning further procedures.

Complex refractive index of freshly excised human breast tissue as a marker of disease.

We report differences in the refractive index of healthy and tumorous freshly excised human breast tissue as determined from reflectance profile measurements at five wavelengths (432 nm, 532 nm, 633 nm, 964 nm, 1551 nm) in the visible and near-infrared using a standard prism-coupling refractometer. These refractive index differences, particularly in the near-infrared, can be used to distinguish fibroadenomas and cancerous growths not only from normal breast tissue but also from each other.

Tissue evacuated during joint replacement procedure as a source of mononuclear cells.

BACKGROUND: Different cell populations from bone marrow were used in various clinical trials for cardiac diseases during last decade. Four clinical studies are ongoing in our institution and enroll patients with cardiac diseases, coronary disease, type 2 diabetes, and osteoarthritis. The density gradient is used to separate bone marrow mononuclear cells. Joint replacement procedures were associated with significant loss of tissue. Usually, excess tissue as bone marrow, peripheral blood and fat are removed to clean operation site. The aim of this study is to prove whether removed tissue during joint replacement procedure can be considered as a significant source of mononuclear cells. METHODS: Excised tissue obtained during joint replacement procedure was collected by AutoLog system. Bone marrow tissue was collected by iliac crest puncture. Mononuclear cells from both sources were isolated by using Ficoll density gradient centrifugation. Flow cytometry was used to detect mononuclear cell, CD34+ population counts and cell viability. Tissue processing yields between the group of joint replacement and iliac crest puncture group were compared. RESULTS: Together, 34 bone marrow tissue processings were performed. On average, samples contained 46.31 ± 9.35 ml of bone marrow solution. Average cell yield in final product was 28.64 ± 9.35 × 106 MNCs and 0.77 ± 1.51 × 106 CD34+ population. In case of tissue removed during joint replacement nine processings were performed. On average samples contained 450 ± 157.69 ml of tissue solution. Average cell yield in final product was 76.67 ± 35.42 × 106 MNCs and 1.33 ± 0.97 × 106 CD34+ population. CONCLUSIONS: Tissue processing analysis shows that tissue removed during joint replacement procedure can be assumed as a significant source of mononuclear cells. Methods used for bone marrow-derived mononuclear cell extraction can be applied to the excess tissue.

Nose-to-Brain Delivery: Investigation of the Transport of Nanoparticles with Different Surface Characteristics and Sizes in Excised Porcine Olfactory Epithelium.

The ability to deliver therapeutically relevant amounts of drugs directly from the nasal cavity to the central nervous system to treat neurological diseases is dependent on the availability of efficient drug delivery systems. Increased delivery and/or therapeutic effect has been shown for drugs encapsulated in nanoparticles; however, the factors governing the transport of the drugs and/or the nanoparticles from the nasal cavity to the brain are not clear. The present study evaluates the potential transport of nanoparticles across the olfactory epithelium in relation to nanoparticle characteristics. Model systems, 20, 100, and 200 nm fluorescent carboxylated polystyrene (PS) nanoparticles that were nonmodified or surface modified with polysorbate 80 (P80-PS) or chitosan (C-PS), were assessed for transport across excised porcine olfactory epithelium mounted in a vertical Franz diffusion cell. Assessment of the nanoparticle content in the donor chamber of the diffusion cell, accompanied by fluorescence microscopy of dismounted tissues, revealed a loss of nanoparticle content from the donor suspension and their association with the excised tissue, depending on the surface properties and particle size. Chitosan surface modification of PS nanoparticles resulted in the highest tissue association among the tested systems, with the associated nanoparticles primarily located in the mucus, whereas the polysorbate 80-modified nanoparticles showed some penetration into the epithelial cell layer. Assessment of the bioelectrical properties, metabolic activity, and histology of the excised olfactory epithelium showed that C-PS nanoparticles applied in pH 6.0 buffer produced a damaging effect on the epithelial cell layer in a size-dependent manner, with fine 20 nm sized nanoparticles causing substantial tissue damage relative to that with the 100 and 200 nm counterparts. Although histology showed that the olfactory tissue was affected by the application of citrate buffer that was augmented by addition of chitosan in solution, this was not reflected in the bioelectrical parameters and the metabolic activity of the tissue. Regarding transport across the excised olfactory tissue, none of the nanoparticle systems tested, irrespective of particle size or surface modification, was transported across the epithelium to appear in measurable amounts in the receiver chamber.