BRCA1-IRIS promotes human tumor progression through PTEN blockade and HIF-1α activation.

BRCA1 is an established breast and ovarian tumor suppressor gene that encodes multiple protein products whose individual contributions to human cancer suppression are poorly understood. BRCA1-IRIS (also known as "IRIS"), an alternatively spliced BRCA1 product and a chromatin-bound replication and transcription regulator, is overexpressed in various primary human cancers, including breast cancer, lung cancer, acute myeloid leukemia, and certain other carcinomas. Its naturally occurring overexpression can promote the metastasis of patient-derived xenograft (PDX) cells and other human cancer cells in mouse models. The IRIS-driven metastatic mechanism results from IRIS-dependent suppression of phosphatase and tensin homolog (PTEN) transcription, which in turn perturbs the PI3K/AKT/GSK-3ß pathway leading to prolyl hydroxylase-independent HIF-1α stabilization and activation in a normoxic environment. Thus, despite the tumor-suppressing genetic origin of IRIS, its properties more closely resemble those of an oncoprotein that, when spontaneously overexpressed, can, paradoxically, drive human tumor progression.

Human Fallopian Tube Epithelial Cell Culture Model To Study Host Responses to Chlamydia trachomatis Infection.

Chlamydia trachomatis infection of the human fallopian tubes can lead to damaging inflammation and scarring, ultimately resulting in infertility. To study the human cellular responses to chlamydial infection, researchers have frequently used transformed cell lines that can have limited translational relevance. We developed a primary human fallopian tube epithelial cell model based on a method previously established for culture of primary human bronchial epithelial cells. After protease digestion and physical dissociation of excised fallopian tubes, epithelial cell precursors were expanded in growth factor-containing medium. Expanded cells were cryopreserved to generate a biobank of cells from multiple donors and cultured at an air-liquid interface. Culture conditions stimulated cellular differentiation into polarized mucin-secreting and multiciliated cells, recapitulating the architecture of human fallopian tube epithelium. The polarized and differentiated cells were infected with a clinical isolate of C. trachomatis, and inclusions containing chlamydial developmental forms were visualized by fluorescence and electron microscopy. Apical secretions from infected cells contained increased amounts of proteins associated with chlamydial growth and replication, including transferrin receptor protein 1, the amino acid transporters SLC3A2 and SLC1A5, and the T-cell chemoattractants CXCL10, CXCL11, and RANTES. Flow cytometry revealed that chlamydial infection induced cell surface expression of T-cell homing and activation proteins, including ICAM-1, VCAM-1, HLA class I and II, and interferon gamma receptor. This human fallopian tube epithelial cell culture model is an important tool with translational potential for studying cellular responses to Chlamydia and other sexually transmitted pathogens.

Use of MRI in diabetic lumbosacral radiculoplexus neuropathy: case report and review of the literature.

Diabetic lumbosacral radiculoplexus neuropathy is often confused with radiculopathy in the context of spinal degenerative disc disease including spinal stenosis. Accuracy in diagnosis may prevent unnecessary interventional procedures including selective nerve root blocks or epidural steroid injections or even surgery in selected cases. Our patient with known diabetes and lumbar disc disease presented with acute onset of pain in L5-S1 distribution of the left lower extremity. Initial MR imaging of the lumbar spine did not show sufficient structural changes to explain her symptomatology. An MR neurogram of the lumbosacral plexus revealed inflammation within the bilateral sciatic and femoral nerves; subsequent EMG demonstrated a generalized sensorimotor neuropathy but no evidence of plexopathy. To our knowledge, this is the first case report that utilized MR imaging of the pelvis to assist in the diagnosis of diabetic lumbosacral radiculoplexus neuropathy (DLRPN).

Mobile learning in medicine: an evaluation of attitudes and behaviours of medical students.

BACKGROUND: Mobile learning (mLearning) devices (such as tablets and smartphones) are increasingly part of the clinical environment but there is a limited and somewhat conflicting literature regarding the impact of such devices in the clinical learning environment. This study aims to: assess the impact of mLearning devices in the clinical learning environment on medical students' studying habits, attitudes towards mobile device supported learning; and the perceived reaction of clinicians and patients to the use of these devices as part of learning in the clinical setting. METHODS: Over three consecutive academic years, 18 cohorts of medical students (total n = 275) on a six-week rotation at a large teaching hospital in London were supplied with mLearning devices (iPad mini) to support their placement-based learning. Feedback on their experiences and perceptions was collected via pre- and post-use questionnaires. RESULTS: The results suggest mLearning devices have a positive effect on the students' perceived efficiency of working, while experience of usage not only confirmed pre-existing positive opinions about devices but also disputed some expected limitations associated with mLearning devices in the clinical workplace. Students were more likely to use devices in 'down-time' than as part of their clinical learning. As anticipated, both by users and from the literature, universal internet access was a major limitation to device use. The results were inconclusive about the student preference for device provision versus supporting a pre-owned device. CONCLUSION: M-learning devices can have a positive impact on the learning experiences medical students during their clinical attachments. The results supported the feasibility of providing mLearning devices to support learning in the clinical environment. However, universal internet is a fundamental limitation to optimal device utilisation.

The birth of aposematism: High phenotypic divergence and low genetic diversity in a young clade of poison frogs.

Rapid radiation coupled with low genetic divergence often hinders species delimitation and phylogeny estimation even if putative species are phenotypically distinct. Some aposematic species, such as poison frogs (Dendrobatidae), have high levels of intraspecific color polymorphism, which can lead to overestimation of species when phenotypic divergence primarily guides species delimitation. We explored this possibility in the youngest origin of aposematism (3-7 MYA) in poison frogs, Epipedobates, by comparing genetic divergence with color and acoustic divergence. We found low genetic divergence (2.6% in the 16S gene) despite substantial differences in color and acoustic signals. While chemical defense is inferred to have evolved in the ancestor of Epipedobates, aposematic coloration evolved at least twice or was lost once in Epipedobates, suggesting that it is evolutionarily labile. We inferred at least one event of introgression between two cryptically colored species with adjacent ranges (E. boulengeri and E. machalilla). We also find evidence for peripheral isolation resulting in phenotypic divergence and potential speciation of the aposematic E. tricolor from the non-aposematic E. machalilla. However, we were unable to estimate a well-supported species tree or delimit species using multispecies coalescent models. We attribute this failure to factors associated with recent speciation including mitochondrial introgression, incomplete lineage sorting, and too few informative molecular characters. We suggest that species delimitation within young aposematic lineages such as Epipedobates will require genome-level molecular studies. We caution against relying solely on DNA barcoding for species delimitation or identification and highlight the value of phenotypic divergence and natural history in delimiting species.

p53 deficiency linked to B cell translocation gene 2 (BTG2) loss enhances metastatic potential by promoting tumor growth in primary and metastatic sites in patient-derived xenograft (PDX) models of triple-negative breast cancer.

BACKGROUND: Despite advances in early diagnosis and treatment of cancer patients, metastasis remains the major cause of mortality. TP53 is one of the most frequently mutated genes in human cancer, and these alterations can occur during the early stages of oncogenesis or as later events as tumors progress to more aggressive forms. Previous studies have suggested that p53 plays a role in cellular pathways that govern metastasis. To investigate how p53 deficiency contributes to late-stage tumor growth and metastasis, we developed paired isogenic patient-derived xenograft (PDX) models of triple-negative breast cancer (TNBC) differing only in p53 status for longitudinal analysis. METHODS: Patient-derived isogenic human tumor lines differing only in p53 status were implanted into mouse mammary glands. Tumor growth and metastasis were monitored with bioluminescence imaging, and circulating tumor cells (CTCs) were quantified by flow cytometry. RNA-Seq was performed on p53-deficient and p53 wild-type tumors, and functional validation of a lead candidate gene was performed in vivo. RESULTS: Isogenic p53 wild-type and p53-deficient tumors metastasized out of mammary glands and colonized distant sites with similar frequency. However, p53-deficient tumors metastasized earlier than p53 wild-type tumors and grew faster in both primary and metastatic sites as a result of increased proliferation and decreased apoptosis. In addition, greater numbers of CTCs were detected in the blood of mice engrafted with p53-deficient tumors. However, when normalized to tumor mass, the number of CTCs isolated from mice bearing parental and p53-deficient tumors was not significantly different. Gene expression profiling followed by functional validation identified B cell translocation gene 2 (BTG2), a downstream effector of p53, as a negative regulator of tumor growth both at primary and metastatic sites. BTG2 expression status correlated with survival of TNBC patients. CONCLUSIONS: Using paired isogenic PDX-derived metastatic TNBC cells, loss of p53 promoted tumor growth and consequently increased tumor cell shedding into the blood, thus enhancing metastasis. Loss of BTG2 expression in p53-deficient tumors contributed to this metastatic potential by enhancing tumor growth in primary and metastatic sites. Furthermore, clinical data support conclusions generated from PDX models and indicate that BTG2 expression is a candidate prognostic biomarker for TNBC.

Two years of a pilot virtual melanoma education program for adolescents in Texas: Assessing knowledge gaps and demographic disparities.

A formal melanoma primary prevention program was developed for a target audience of grade-school adolescents near Houston, Texas, focusing on skin cancer education and promoting long-term sun safety habits. Upon application of a multivariable regression model, adolescents of Black, non-Hispanic race, male gender, and lower grade levels were independent predictors of lower baseline skin cancer prevention knowledge. These findings reveal potential areas to prioritize when addressing knowledge gaps in the adolescent community.

Therapeutic avenues in bone repair: Harnessing an anabolic osteopeptide, PEPITEM, to boost bone growth and prevent bone loss.

The existing suite of therapies for bone diseases largely act to prevent further bone loss but fail to stimulate healthy bone formation and repair. We describe an endogenous osteopeptide (PEPITEM) with anabolic osteogenic activity, regulating bone remodeling in health and disease. PEPITEM acts directly on osteoblasts through NCAM-1 signaling to promote their maturation and formation of new bone, leading to enhanced trabecular bone growth and strength. Simultaneously, PEPITEM stimulates an inhibitory paracrine loop: promoting osteoblast release of the decoy receptor osteoprotegerin, which sequesters RANKL, thereby limiting osteoclast activity and bone resorption. In disease models, PEPITEM therapy halts osteoporosis-induced bone loss and arthritis-induced bone damage in mice and stimulates new bone formation in osteoblasts derived from patient samples. Thus, PEPITEM offers an alternative therapeutic option in the management of diseases with excessive bone loss, promoting an endogenous anabolic pathway to induce bone remodeling and redress the imbalance in bone turnover.

A review of the pathogenesis of adult peritonsillar abscess: time for a re-evaluation.

OBJECTIVES: To perform a multifactorial exploration of the aetiology of peritonsillar abscess (PTA) in adults, in order to develop greater clinical understanding of the condition and improve management. DESIGN: A literature review exploring key pathogens, predisposing host factors and current pathogenic hypotheses. METHODS: A PubMed search for articles published between January 1980 and January 2012 using the terms 'peritonsillar abscess AND microbiology', 'peritonsillar abscess AND pathophysiology' and 'peritonsillar abscess AND etiology'. RESULTS: Major pathogens in PTA are opportunistic microflora. Group A streptococcal PTA infections present differently from polymicrobial PTA. A number of host factors influence the conditions required for the pathogenesis of PTA. CONCLUSIONS: PTA is clinically distinct from acute tonsillitis and occurs in people with a chronic underlying susceptibility. Targeting host factors, including oral hygiene, antibiotic use and smoking, may prevent PTA. Re-education of clinicians concerning the aetiology of PTA is necessary for appropriate disease management.

Lymph node dissections and survival in sublobar resection of non-small cell lung cancer ≤ 20 mm.

BACKGROUND: A randomized trial of lobectomy versus segmentectomy for small-sized (≤ 20 mm) non-small cell lung cancer (NSCLC) showed that patients who had undergone segmentectomy had a significantly longer overall survival (OS) than those who had lobectomy. More attention is needed regarding the required extent of thoracic lymphadenectomy in patients with small-sized NSCLC who undergo sublobar resection. METHODS: The National Cancer Database was queried for patients with clinically node-negative NSCLC ≤ 20 mm who had undergone sublobar resection between 2004 and 2017. OS of NSCLC patients by the number of lymph node dissections (LNDs) was analyzed using log-rank tests and Cox proportional hazards model. The cutoff value of the LNDs was set to 10 according to the Commission on Cancer's recommendation. RESULTS: This study included 4379 segmentectomy and 23,138 wedge resection cases. The sequential improvement in the HRs by the number of LNDs was evident, and the HR was the lowest if the number of LNDs exceeded 10. Patients with ≤ 9 LNDs had a significantly shorter OS than those with ≥ 10 LNDs (hazard ratio [HR] 1.50, 95% confidence interval [CI] 1.40-1.61, P < 0.0001). Multivariable analysis revealed that performing ≤ 9 LNDs was an independent factor for predicting OS (HR for death: 1.34, 95% CI 1.24-1.44, P < 0.0001). These results remained significant in subgroup analyses by the type of sublobar resection (segmentectomy, wedge resection). CONCLUSIONS: Performing ≥ 10 LNDs has a prognostic role in patients with small-sized NSCLC even if the resection is sublobar.

Failure of Nasal Defect Closures Following the Use of Continuous Positive Airway Pressure.

In this paper, we report a case series of three patients who developed nasal tip necrosis following Mohs micrographic surgery (MMS), complicated by the concomitant use of a continuous positive airway pressure (CPAP) machine for sleep apnea.

Demographics of Skin Cancer Knowledge Among Middle and High Schoolers in Texas.

INTRODUCTION: Adolescents, an age group that can reduce sun exposure early, may benefit from school-based skin cancer education programs. Literature regarding the demographics of melanoma knowledge is sparse. OBJECTIVES: This study sought to evaluate melanoma knowledge among students in Texas viewing John Wayne Cancer Foundation Block the Blaze (JWCFBTB) presentations and identify group differences with regard to sociodemographic factors. METHODS: Before JWCFBTB presentations delivered in Houston and Dallas by health professions students, a pre-presentation melanoma knowledge quiz was distributed. This survey was adapted from a 2000 study evaluating melanoma knowledge in middle and high schoolers in Houston and Dallas. Respondents were also asked to provide their gender, age, grade, race, parent education level, and whether they are first-generation American. ANOVA and Tukey tests were used to evaluate demographic group differences in scores. Logistic regression models determined predictors of answering selected true/false questions correctly. RESULTS: One-way ANOVA tests showed statistically significant group differences in pre-test scores for all demographic factors evaluated. Females, Whites/Caucasians, students whose parents hold graduate degrees, and older students had higher scores. Black students and non-first-generation Americans were more likely to answer selected commonly missed questions correctly. CONCLUSIONS: Results from 2000 and 2020-2021 indicate older students from higher grade levels know more about melanoma, suggesting adolescents may benefit from earlier skin cancer education. Racial minorities and individuals of low socioeconomic status, who suffer from disparities in melanoma treatment and mortality, showed poorer melanoma knowledge. Targeting skin cancer education to disadvantaged schools may help remedy such gaps.

Predictors of success in establishing orthotopic patient-derived xenograft models of triple negative breast cancer.

Patient-derived xenograft (PDX) models of breast cancer are an effective discovery platform and tool for preclinical pharmacologic testing and biomarker identification. We established orthotopic PDX models of triple negative breast cancer (TNBC) from the primary breast tumors of patients prior to and following neoadjuvant chemotherapy (NACT) while they were enrolled in the ARTEMIS trial (NCT02276443). Serial biopsies were obtained from patients prior to treatment (pre-NACT), from poorly responsive disease after four cycles of Adriamycin and cyclophosphamide (AC, mid-NACT), and in cases of AC-resistance, after a 3-month course of different experimental therapies and/or additional chemotherapy (post-NACT). Our study cohort includes a total of 269 fine needle aspirates (FNAs) from 217 women, generating a total of 62 PDX models (overall success-rate = 23%). Success of PDX engraftment was generally higher from those cancers that proved to be treatment-resistant, whether poorly responsive to AC as determined by ultrasound measurements mid-NACT (p = 0.063), RCB II/III status after NACT (p = 0.046), or metastatic relapse within 2 years of surgery (p = 0.008). TNBC molecular subtype determined from gene expression microarrays of pre-NACT tumors revealed no significant association with PDX engraftment rate (p = 0.877). Finally, we developed a statistical model predictive of PDX engraftment using percent Ki67 positive cells in the patient's diagnostic biopsy, positive lymph node status at diagnosis, and low volumetric reduction of the patient's tumor following AC treatment. This novel bank of 62 PDX models of TNBC provides a valuable resource for biomarker discovery and preclinical therapeutic trials aimed at improving neoadjuvant response rates for patients with TNBC.

Clinical impact of number of lymph nodes dissected on postoperative survival in node-negative small cell lung cancer.

Objectives: Small cell lung cancer (SCLC) is a lethal histologic subtype of lung cancer. Although the Commission on Cancer recommends pathological examination of at least 10 lymph nodes dissected (LNDs) for resected early-stage non-small cell lung cancer, its survival benefit of LNDs in patients with early-stage SCLC is unknown. Methods: The National Cancer Database was queried for SCLC patients with clinical stage I-II and clinical N0, NX disease per AJCC 7th edition who had undergone lobectomy between 2004 and 2017. Overall survival of SCLC patients by the number of LNDs was compared using Log-rank tests. Univariate and multivariable Cox proportional hazards analyses were performed. Results: In total, 688 (42%), 311 (20%), 247 (16%), 196 (12%), 126 (8%), and 36 (2%) of 1,584 patients with early-stage SCLC had ≥10, 7-9, 5-6, 3-4, 1-2, and 0 LNDs, respectively. The sequential improvement in the HRs was no longer evident if the number of LNDs exceeds 4. Patients with ≥3 LNDs (n = 1,422) had a significantly longer overall survival than those with <3 LNDs (n = 162) (hazard ratio for death: 0.76, 95% confidence interval: 0.62-0.94, P = 0.0087). Multivariate analysis revealed that ≥3 LNDs was an independent factor for predicting overall survival (hazard ratio for death: 0.76, 95% confidence interval: 0.61-0.93, P = 0.0083). Conclusions: Although we are reluctant to recommend a definitive "optimal number" of LNDs, our findings suggest the prognostic and therapeutic roles for performing ≥3 LNDs in patients with early-stage SCLC who undergo lobectomy.

Revisiting the East-West advancement flap: great for multiple anatomic locations.

BACKGROUND: The east-west advancement flap is a simple flap traditionally used to repair Mohs surgery defects on the nose. We aim to demonstrate this flap can be used with good cosmetic outcome and minimal complications on a variety of anatomical sites. METHODS: This study was a case series of four patients taking place between March 2021 and September 2021 with 4- to 6-week postoperative follow-up. RESULTS: Four male patients were included in the study. Repair sites included the helix, chin, wrist, and scalp. All patients and the Mohs surgeon reported satisfaction with the cosmetic outcome at 4- to 6-week postoperative follow-up with no complications. CONCLUSION: The east-west advancement flap is a viable repair option for Mohs surgery defects on a variety of anatomical sites.

How to Address Scar Pincushioning and Webbing of the Nasal Dorsum Using Surgical Defatting and Z-plasty.

Nonmelanoma skin cancer is the most common cancer, typically growing in sun-exposed areas, such as the nose. After complete excision of the tumor, the subsequent scar may exhibit multiple complications that are easily noticeable and cosmetically unsatisfactory. When performing a revision of such a scar, using a single surgical technique may be insufficient; rather, the surgeon may need to carefully plan and utilize several techniques to achieve the best cosmetic outcome. Here, we report a case that demonstrates successful use of surgical defatting and Z-plasty techniques to revise a scar of the nasal dorsum that exhibited pincushioning and webbing.

Geometry-Based Computational Fluid Dynamic Model for Predicting the Biological Behavior of Bone Tissue Engineering Scaffolds.

The use of biocompatible and biodegradable porous scaffolds produced via additive manufacturing is one of the most common approaches in tissue engineering. The geometric design of tissue engineering scaffolds (e.g., pore size, pore shape, and pore distribution) has a significant impact on their biological behavior. Fluid flow dynamics are important for understanding blood flow through a porous structure, as they determine the transport of nutrients and oxygen to cells and the flushing of toxic waste. The aim of this study is to investigate the impact of the scaffold architecture, pore size and distribution on its biological performance using Computational Fluid Dynamics (CFD). Different blood flow velocities (BFV) induce wall shear stresses (WSS) on cells. WSS values above 30 mPa are detrimental to their growth. In this study, two scaffold designs were considered: rectangular scaffolds with uniform square pores (300, 350, and 450 µm), and anatomically designed circular scaffolds with a bone-like structure and pore size gradient (476-979 µm). The anatomically designed scaffolds provided the best fluid flow conditions, suggesting a 24.21% improvement in the biological performance compared to the rectangular scaffolds. The numerical observations are aligned with those of previously reported biological studies.