The Throat Pack Debate: A Review of Current Practice in UK and Ireland Cleft Centers.

INTRODUCTION: The use of throat packs during oropharyngeal surgery has long been a topic of debate among cleft surgeons. The advantage of inserting an absorbent tulle within the pharynx must be weighed against the risk of unintended retention postoperatively. Despite safety check mechanisms in place, retention may occur with potentially life-threatening consequences. We present a comprehensive review of throat pack use in all cleft units within the United Kingdom and Ireland. METHODS: All 20 cleft surgery units in the United Kingdom and Ireland were surveyed on their use of throat packs in children aged 6 months to 2 years undergoing elective cleft palate surgery. RESULTS: The response rate to the survey was 100%. Seventy-five percent of units currently use throat packs; in 40%, they are used in addition to cuffed endotracheal tubes (ETTs). Inclusion of the throat pack in the surgical swab count was perceived as the safest mechanism employed to avoid retention. 26.1% of respondents were aware of at least 1 incident of pack retention in their unit. DISCUSSION/CONCLUSION: The reported UK and Irish experience demonstrates that three-quarters of units routinely use packs. Notably, a quarter of respondents to the survey have experience of an incident of throat pack retention. Nevertheless, the majority of respondents considered the perceived risk of retaining a pack to be low. The growing use of microcuffed ETTs in UK cleft units paired with a low incidence of perioperative complications when a throat pack is not introduced might prompt cleft surgeons to review routine pharyngeal packing.

A simple, inexpensive and non-microscope based model for microsurgical training.

In this manuscript we present a simple, inexpensive, non-microscope training model for microsurgery.

Identification of a Hematopoietic Cell Dedifferentiation-Inducing Factor.

It has long been realized that hematopoietic cells may have the capacity to trans-differentiate into non-lymphohematopoietic cells under specific conditions. However, the mechanisms and the factors for hematopoietic cell trans-differentiation remain unknown. In an in vitro culture system, we found that using a conditioned medium from proliferating fibroblasts can induce a subset of hematopoietic cells to become adherent fibroblast-like cells (FLCs). FLCs are not fibroblasts nor other mesenchymal stromal cells, based on their expression of type-1 collagen, and other stromal cell marker genes. To identify the active factors in the conditioned medium, we cultured fibroblasts in a serum-free medium and collected it for further purification. Using the fractions from filter devices of different molecular weight cut-offs, and ammonium sulfate precipitation collected from the medium, we found the active fraction is a protein. We then purified this fraction by using fast protein liquid chromatography (FPLC) and identified it by mass spectrometer as macrophage colony-stimulating factor (M-CSF). The mechanisms of M-CSF-inducing trans-differentiation of hematopoietic cells seem to involve a tyrosine kinase signalling pathway and its known receptor. The FLCs express a number of stem cell markers including SSEA-1 and -3, OCT3/4, NANOG, and SOX2. Spontaneous and induced differentiation experiments confirmed that FLCs can be further differentiated into cell types of three germ layers. These data indicate that hematopoietic cells can be induced by M-CSF to dedifferentiate to multipotent stem cells. This study also provides a simple method to generate multipotent stem cells for clinical applications.

IDO expressing fibroblasts promote the expansion of antigen specific regulatory T cells.

Regulatory CD4(+)CD25(+)Foxp3(+) T cells (Tregs) can be induced and expanded by dendritic cells (DCs) in the presence of the enzyme indoleamine 2,3-dioxygenase (IDO). Here we report that a possible alternative to DCs are IDO expressing dermal fibroblasts (DFs), which are easier to isolate and sustain in culture compared to DCs. When mouse splenocytes were co-cultured with IDO expressing DFs, a significant increase in frequency and the number of Tregs was found compared to those of control group (13.16%±1.8 vs. 5.53%±1.2, p<0.05). Despite observing a higher total number of dead CD4(+) cells in the IDO group, there was a more abundant live CD4(+)CD25(+) subpopulation in this group. Further analysis reveales that these CD4(+) CD25(+) cells have the capacity to expand in the presence of IDO expressing DFs. Greater number of CTLA-4(+) cells and high expression of TGF-ß and IL-10 were found in CD4(+) cells of the IDO group compared to those of the controls. This finding confirmed a suppressive functionality of the expanded Tregs. Furthermore, CD4(+) CD25(+) cells isolated from the IDO group showed an alloantigen specific suppressive effect in a mixed lymphocyte reaction assay. These results confirm that IDO expressing dermal fibroblasts can expand a population of suppressive antigen specific Tregs. In conclusion, IDO expressing dermal fibroblasts have the capacity to stimulate the expansion of a subset of Tregs which can be used to generate antigen-specific immune tolerance.