Oral Losartan After Limited Mandibulectomy for Treatment of Desmoid-Type Fibromatosis

Desmoid-type fibromatosis (DF) is a rare soft tissue lesion with an annual incidence of 2 to 4 per million population and peak incidence occurring at approximately 4.5 years of age. While benign, the tumor has a locally aggressive infiltrative growth pattern and a high rate of recurrence. Given the functional and aesthetic implications of excision and reconstruction in the facial skeleton, novel medical treatment options are highly desirable. We describe the case of a 3-year-old boy who presented with an enlarging, asymptomatic mass involving the left mandible. Biopsy revealed an immunohistochemical profile consistent with DF. Despite the high likelihood of recurrence, conservative, mandible-sparing en bloc resection and limited mandibulectomy were performed. Pathological and immunohistochemical analysis of the resection specimen revealed DF with grossly positive margins and elevated expression of angiotensin II type 1 receptor. Postoperative medical treatment with the angiotensin receptor blocker losartan was initiated. The patient remains medically stable and disease progression-free on repeat imaging at 20 months post-resection. We describe for the first time the successful use of the angiotensin blocker losartan following conservative surgery for management of DF.

The Impact of the COVID-19 Pandemic on Breast Reconstruction: A Canadian Perspective

BACKGROUND

The COVID-19 pandemic has led to unprecedented challenges and restrictions in surgical access across Canada, including for breast reconstructive services which are an integral component of comprehensive breast cancer care. We sought to determine how breast reconstructive services are being restricted, and what strategies may be employed to optimize the provision of breast reconstruction through a pan-Canadian evaluation from the providers' perspective.

METHODS

This was a cross-sectional survey of Canadian plastic and reconstructive surgeons who perform breast reconstruction. The 33-item web-based questionnaire was developed by a pan-Canadian working group of breast reconstruction experts and disseminated via email to members of the Canadian Society of Plastic Surgery. The questionnaire queried respondents on the impact of the COVID-19 pandemic and associated restrictions on surgeons' breast reconstruction practice patterns and opinions on strategies for resource utilization.

RESULTS

Responses were received from 49 surgeons, who reported practicing in 8 of 10 Canadian provinces. Restrictions on the provision of breast reconstructive procedures were most limited during the First Wave of the COVID-19 pandemic, where all respondents reported at least some reduction in capacity and more than a quarter reporting complete cessation. Average reported reduction in capacity ranged from 31% to 78% across all 3 waves. Autologous, delayed, and prophylactic reconstructions were most commonly restricted.

CONCLUSION

This study provides a pan-Canadian impact assessment on breast reconstructive services during the COVID-19 pandemic from the providers' perspective. To uphold the standards of patient-centred care, a unified approach to strategically reorganize health care delivery now and in the future is needed.

Understanding child anxiety before otoplasty: A qualitative study

BACKGROUND

Pre-operative anxiety in pediatric patients is a major concern in surgical care due to the future medical and behavioral consequences that can occur. The objective of this study was to understand the factors that lead to pre-operative anxiety before otoplasty.

METHODS

Participants at a Canadian pediatric hospital were identified to discuss their experience with otoplasty and any anxiety they experienced using a semi-structured interview. Interviews were transcribed and analyzed using a qualitative semantic thematic approach. Major themes were identified and supporting quotes were extracted from the interviews.

RESULTS

Ten participants were enrolled in the study. Three main themes (and seven subthemes) were identified: concern for post-operative well-being (perception by others, physical well-being, and negative experiences), fear of the unknown (surgical uncertainty, vulnerability), and support (family and friends, surgeon).

CONCLUSIONS

Otoplasty was shown to be an emotional experience for participants with multiple sources of anxiety being identified. While most anxiety sources were similar to those for other pediatric surgeries, a number were specific to otoplasty and its post-operative care plan. This understanding of anxiety will allow physicians and care teams to better prepare patients and their families for otoplasty and enhance the patient's overall experience.

Impaired trafficking of connexins in androgen-independent human prostate cancer cell lines and its mitigation by alpha-catenin

Gap junctions, composed of connexins, provide a pathway of direct intercellular communication for the diffusion of small molecules between cells. Evidence suggests that connexins act as tumor suppressors. We showed previously that expression of connexin-43 and connexin-32 in an indolent prostate cancer cell line, LNCaP, resulted in gap junction formation and growth inhibition. To elucidate the role of connexins in the progression of prostate cancer from a hormone-dependent to -independent state, we introduced connexin-43 and connexin-32 into an invasive, androgen-independent cell line, PC-3. Expression of these proteins in PC-3 cells resulted in intracellular accumulation. Western blot analysis revealed a lack of Triton-insoluble, plaque-assembled connexins. In contrast to LNCaP cells, connexins could not be cell surface-biotinylated and did not reside in the cell surface derived endocytic vesicles, in PC-3 cells, suggesting impaired trafficking to the cell surface. Intracellular accumulation of connexins was observed in several androgen-independent prostate cancer cell lines. Transient expression of alpha-catenin facilitated the trafficking of both connexins to the cell surface and induced gap junction assembly. Our results suggest that impaired trafficking, and not the inability to form gap junctions, is the major cause of communication deficiency in human prostate cancer cell lines.

Mechanisms of inactivation of E-cadherin in breast cancer cell lines

Loss of E-cadherin (CDH1) function is thought to contribute to progression in breast cancer and other solid tumors by increasing proliferation, invasion, and/or metastasis. In some cases, the restoration of CDH1 function may be an important therapeutic option. This possibility will depend on the mechanism by which CDH1 is inactivated. Here we present analyses of CDH1 expression, genetic mutation, and promoter methylation in CDH1 in 10 commonly used breast cancer cell lines. Five cell lines (BT-474, MCF-7, MDA-MB-361, MDA-MB-468, and T-47D) expressed CDH1 and were genetically normal. Five others (SK-BR-3, 600 MPE, MDA-MB-134 IV, CAMA1, and MDA-MB-435) did not express CDH1. Fluorescence in situ hybridization analyses of each of these cell lines showed evidence for the physical deletion of one allele of CDH1, and three cell lines were found to carry homozygous deletions. SK-BR-3 was deleted from exon 12 through the promoter; exon 6 was deleted in MDA-MB-134 IV cells, and 600 MPE cells carried a 21-bp deletion in the splicing acceptor site for exon 9. CAMA1 seemed to have been inactivated through promoter methylation. No explanation was found for the inactivation of CDH1 in MDA-MB-435.

Human cytotrophoblasts adopt a vascular phenotype as they differentiate. A strategy for successful endovascular invasion?

Establishment of the human placenta requires that fetal cytotrophoblast stem cells in anchoring chorionic villi become invasive. These cytotrophoblasts aggregate into cell columns and invade both the uterine interstitium and vasculature, anchoring the fetus to the mother and establishing blood flow to the placenta. Cytotrophoblasts colonizing spiral arterioles replace maternal endothelium as far as the first third of the myometrium. We show here that differentiating cytotrophoblasts transform their adhesion receptor phenotype so as to resemble the endothelial cells they replace. Cytotrophoblasts in cell columns show reduced E-cadherin staining and express VE-(endothelial) cadherin, platelet-endothelial adhesion molecule-1, vascular endothelial adhesion molecule-1, and alpha-4-integrins. Cytotrophoblasts in the uterine interstitium and maternal vasculature continue to express these receptors, and, like endothelial cells during angiogenesis, also stain for alphaVbeta3. In functional studies, alphaVbeta3 and VE-cadherin enhance, while E-cadherin restrains, cytotrophoblast invasiveness. Cytotrophoblasts expressing alpha4 integrins bound immobilized VCAM-1 in vitro, suggesting that this receptor-pair could mediate cytotrophoblast-endothelium or cytotrophoblast-cytotrophoblast interactions in vivo, during endovascular invasion. In the pregnancy disorder preeclampsia, in which endovascular invasion remains superficial, cytotrophoblasts fail to express most of these endothelial markers (Zhou et al., 1997. J. Clin. Invest. 99:2152-2164.), suggesting that this adhesion phenotype switch is required for successful endovascular invasion and normal placentation.

Characterization and quantitation of murine-delayed hypersensitivity responses elicted with particle-associated human gamma-globulin

Parameters delineating the utilization of particle-associated human gamma-globulin to quantitate murine-delayed hypersensitivity (DHS) responses include: (1) the conditions used to prepare HGG-coated polystyrene latex particles; (2) the marked increase in sensitivity of detection of delayed immune responsiveness using particle-bound HGG; (3) a histologic analysis of the lesions induced by HGG-latex in DHS mice, and (4) the increased retention of particle-associated as opposed to soluble HGG at the site of challenge. The potential utilization of particle-bound antigens as a sensitive method of assessing the role of delayed-type responsiveness in tumor and transplantation immunity is discussed.