Citations

Xeroderma Pigmentosum group C (XP-C) is an autosomal recessive disorder caused by mutations in the XPC gene, leading to defective nucleotide excision repair. This defect leads to genomic instability and a profound cancer predisposition. To model this disease, we generated induced pluripotent stem cells (iPSCs) from an XP-C patient carrying a novel homozygous nonsense mutation in the XPC gene (c.1830C>A). The resulting iPSCs demonstrated typical pluripotent characteristics, including expression of key markers and trilineage differentiation capability. However, genomic assessment revealed progressive karyotypic instability during extended culture. While initial whole-genome sequencing detected no major chromosomal abnormalities, subsequent G-banding analysis identified acquired trisomy 12 in two lines (CL12 and CL27) and a derivative X chromosome in a third line (CL30). These abnormalities were absent in early-passage analyses, indicating that they were acquired and selected for during extended culture. The acquisition of a derivative X chromosome in CL30, alongside recurrent trisomy 12, represents a unique cytogenetic signature likely attributable to the underlying XPC defect. We hypothesize that the loss of GG-NER creates a permissive genomic environment, accelerating the accumulation of DNA damage and chromosomal missegregation under replicative stress. This temporal divergence in genomic integrity highlights how culture pressures drive chromosomal evolution in XP-C iPSCs independently of initial reprogramming. Our findings emphasize that XP-C iPSCs require continuous genomic surveillance and provide a model for investigating how DNA repair deficiencies interact with in vitro culture stress.

ABSTRACT Tendon adhesion is a major complication following tendon reconstruction surgery in the hand. Previous studies showed that a combination of hyaluronic acid (HA) and gelatin, covalently bound to the tendon surface, can provide a durable gliding surface to reduce adhesions in animal models both in‐vitro and in‐vivo. We have developed a similar product using good manufacturing practice (GMP) standards, in preparation for use in humans. This study aimed to examine the frictional properties and elastic modulus of the Manufactured Tendon Lubricant (MTL) when applied to an extrasynovial canine peroneus longus (PL) tendon in‐vitro. Twenty PL tendons along with the 2nd and 5th digits from adult canine forepaws, were obtained (mean age: 12 months, weight: 35 kg) from animals sacrificed in Institutional Animal Care and Use Committee (IACUC) approved protocols. Tendons were treated either with the MTL or saline solution, as a control. Eight tendons from each group (MTL vs saline‐treated) underwent friction testing, using a previously described protocol, followed by indentation testing to assess tendon elastic modulus (a marker of successful crosslinking). Two tendons from each group were not tested and were sent for scanning electron microscopy (SEM). The MTL group had significantly ( p < 0.001) lower friction and gliding resistance as well as higher elastic modulus of the PL tendons, compared to the saline group. This study demonstrates that MTL provides lubricating effects and fixation to the tendon surface and may be suitable for human testing.

ABSTRACT Chimeric antigen receptor T-cell (CART) and T-cell engager (TCE) therapies targeting B-cell maturation antigen (BCMA) are transforming the treatment landscape for relapsed multiple myeloma (MM). However, despite impressive initial response rates, most patients eventually relapse. To investigate this unmet medical need, we applied whole-genome sequencing (WGS) to MM cells from cohorts of 102 relapsed patients treated with anti-BCMA CART and TCE therapies. Several genomic alterations were associated with clinical outcomes, particularly primary refractoriness, including high genomic complexity and mutations in genes regulating plasma cell identity, which predicted resistance to therapy. Single-cell RNA sequencing further revealed that MM cells from refractory patients exhibited high proliferation signatures and reduced expression of TNFRSF17 (encoding BCMA), while were less enriched for plasma cell–associated transcriptional programs, a phenomenon we term “plasma cell identity escape.” This profile was strongly associated with immune dysregulation of CD8 T cells including increased activation and exhaustion. This evolution of MM toward a more proliferative and lineage-divergent state, refractory to the anti-BCMA T-cell redirecting therapies, was functionally validated in preclinical MM mouse models. Collectively, our results comprehensively define the cellular and molecular mechanisms underlying primary resistance to anti-BCMA therapies.

Background ‘Exception from informed consent’ research requires community consultation to ensure that the views of the local population have been considered. Using market research companies to distribute surveys across local populations is attractive because it ensures adequate response rates. It is not known whether individuals who respond to surveys are typical of the targeted communities. The purpose of this study is to compare the demographics of the survey respondents with that of the general population in the same area. Methods This is an analysis of data collected as part of the ‘Trauma Resuscitation with Group O Whole Blood or Products’ (TROOP) trial. The surveys used a commercial market research service to reach the communities of interest and consisted of 18 questions designed to evaluate respondents’ willingness to be enrolled in the TROOP trial and the demographics of survey respondents. Results Catchment populations varied from 0.5 to 9.4 million residents, with a total of 33.5 million. The racial and ethnic composition of the population (and the survey respondents, in brackets) was 44.8% (57.0%) white, 25.7% (13.4%) Hispanic, 12.7% (19.4%) black, 8.0% (2.5%) multiracial, 7.9% (4.4%) Asian, 0.7% (0.9%) Native American, and 0.2% (0.5%) Islanders. Of the male population (and survey respondents, in brackets), 12.2% (15.3%) were aged 18years to 24 years, 20.5% (22.3%) aged 25 years to 34 years, 18.1% (24.9%) aged 35 years to 44 years, 16.3% (18.5%) aged 45 years to 54 years, 15.5% (14.8%) aged 55 years to 64 years, and 17.4% (4.3%) aged 65 years and over. Of the female population (and survey respondents, in brackets), 11.0% (18.5%) were aged 18 years to 24 years, 18.4% (22.6%) aged 25 years to 34 years, 16.4% (23.5%) aged 35 years to 44 years, 15.0% (17.3%) aged 45 years to 54 years, 18.5% (14.1%) aged 55 years to 64 years, and 20.6% (3.9%) aged 65 years and over. Conclusions For this trial, using a market research company to distribute community surveys resulted in respondents that are broadly representative of the geographic areas where the trial will be conducted, except for individuals over the age of 65 years and older. This finding provides reassurance to investigators and institutional review boards that the views expressed by respondents are representative of the population where the trial will be conducted. Level of evidence III

ABSTRACT The concentration of cells is a key component of modern blood tests. Given the biomarker potential of extracellular vesicles (EVs) in blood, we aimed to establish reference ranges for blood cell‐derived EVs using flow cytometry. To address the orders‐of‐magnitude variability in reported EV concentrations between different flow cytometers (FCMs), we first validated a calibration methodology to enable reproducible EV concentration measurements. The methodology was evaluated in an interlaboratory comparison study and shows that calibration reduces the median absolute deviation of EV concentrations measured on 25 different FCMs from 67 % to 25 %–31 %. The calibration methodology was then used to determine reference ranges of erythrocyte‐, leukocyte‐, and platelet‐derived EVs in human blood plasma in a cohort of healthy individuals ( n = 224). This study demonstrates that calibration enables comparable concentration measurements of blood cell‐derived EVs, thereby bringing EVs one step closer to clinical applications.

ABSTRACT Accurate identification of dysplasia in Barrett's esophagus (BE) remains a challenge. Advanced optical imaging techniques may allow for better localization of dysplasia in BE. Here, we have assessed the potential clinical utility of a previously described multimodal imaging probe combining optical coherence tomography (OCT) with angle‐resolved low coherence interferometry (a/LCI) to prospectively identify dysplasia in BE. Imaging was conducted on 37 patients undergoing endoscopic surveillance of BE, yielding co‐registered biopsies of 50 esophageal sites. The a/LCI nuclear morphology data were compared to a previous decision line to prospectively predict dysplasia, demonstrating 100% sensitivity, 93% specificity, and 94% overall accuracy. The NPV was 100%, comparable to previous a/LCI studies. The addition of OCT imaging markedly improved PPV and specificity, compared to previous studies with a/LCI alone, illustrating the clinical utility of the combined platform. These findings suggest that combining OCT and a/LCI enables better detection of dysplasia by providing better guidance.

ABSTRACT Primary cutaneous NUT adnexal carcinoma is an emerging provisional tumor entity characterized by NUTM1 rearrangement with fusion partners different from poroid neoplasms. These tumors should be distinguished from NUT carcinomas with a histopathologic appearance of poorly differentiated squamous cell carcinoma, which tend to behave more aggressively and demonstrate a widespread anatomic distribution. Since fewer than 20 cases of NUT adnexal carcinoma have been reported in the literature, we report herein another case to enhance our knowledge of the spectrum of clinical and pathologic features associated with this tumor. This case is characterized by an unusual clinical course. The lesion was present and slowly progressed over the course of 13 years prior to biopsy and excision. The tumor was composed of epithelial and myoepithelial elements with a range of features, including ductal, cribriform, and solid, with papillary, secretory, and keratocystic changes. The patient underwent wide local excision and sentinel lymph node biopsy, which revealed metastatic tumor. Molecular testing identified a BRD3‐NUTM1 fusion, confirming the diagnosis of NUT adnexal carcinoma. The patient remains disease‐free at 1‐year follow‐up without further therapy.

Background The past two decades have witnessed tremendous growth in the appreciation and treatment of sacroiliac joint (SIJ) complex pain, including anatomical dissections that shed light on innervation, an appreciation for the contribution of extra-articular components to SIJ complex pain, the advent of radiofrequency ablation (RFA) and a host of minimally-invasive surgical techniques. Yet, there is no standardization of diagnosis and treatment paradigms. Methods In February 2023, the Boards of Directors for the American Academy of Pain Medicine (AAPM) and American Society of Regional Anesthesia & Pain Medicine (ASRA-PM) approved the development of multispecialty guidelines on SIJ complex pain. Thirty partner organizations with clinical and scientific interests in SIJ complex pain were identified, and formal letters of request-for-participation were sent to each, along with a request for nominees to serve on the committee. Twenty five organizations agreed to participate in addition to the Departments of Defense and Veterans Affairs. A steering committee developed 21 questions, which spanned criteria for diagnosis, non-interventional and interventional treatments including surgery, technical parameters on how to optimize results, and what constitutes positive outcomes. Questions were methodically assigned to specialized modules comprising 4–5 members with complementary expertise, who collaborated with the Subcommittee Lead and one of three Committee Chairs to develop preliminary drafts. Following thorough revisions, these drafts were subsequently submitted to the full committee for comprehensive review. A modified Delphi method was used in which the answers to questions were sent to the committee en bloc and comments were returned in a non-blinded fashion to the Chairs, who incorporated the comments and sent out revised versions until consensus was achieved. During a committee meeting before commencement, it was agreed that recommendations would be noted when there was >50% agreement among committee members, but that a formal recommendation would require ≥75% consensus. Results Twenty-one organizations formally endorsed the guidelines. The American Society of Anesthesiologists, and American Academy of Physical Medicine & Rehabilitation, and the North American Spine Society affirmed the benefit of the guidelines but did not officially endorse them. The American Academy of Neurology declined to affirm the benefit of the guidelines citing ‘lack of relevance to their membership.’ Per policies, while the Departments of Defense and Veterans Affairs did not formally review the guidelines for endorsement, their representatives approved them. In addition to being endorsed or the benefit affirmed by all voting organizations, complete consensus from committee members was obtained on all 21 questions. On two recommendations, there were dissensions from three societies who thought that selecting patients for sacral lateral branch RFA and minimally-invasive fusion should be based on ≥75% relief from two blocks instead of at least 50% relief from a single block before RFA, and greater than 50% pain relief with documented functional improvement after a single block before fusion. One additional society (Latin American Society of Regional Anesthesia) abstained on the statement that the evidence is stronger for extra-articular than intra-articular injections. The committee found that a battery of physical exam tests has reasonable sensitivity, but lower specificity, for identifying intra-articular but not extra-articular pain, with negative tests having greater predictive value than positive ones. Intra-articular injections have diagnostic validity for SIJ intra-articular, but not extra-articular, pain. There is unclear or negative evidence for imaging. The prevalence rates of intra-articular and extra-articular pathology are comparable, with both intra- and extra-articular steroid injections providing at least 4 weeks of relief in well-selected patients. However, the evidence is slightly stronger for extra-articular corticosteroid injections to provide short-term relief. The evidence base for non-interventional therapies is indirect, extrapolated mostly from low back pain studies. There is weak evidence supporting dextrose-based prolotherapy and platelet-rich plasma to provide at least 3 months of pain relief. There is strong evidence for sacral lateral branch RFA to provide relief for at least 6 months in individuals with extra-articular pathology, with face validity and indirect evidence from randomized trials supporting sacral lateral branch blocks as a prognostic tool. There is stronger evidence for larger lesions or more aggressive lesioning strategies than for less stringent techniques. There is weak evidence to support non-steroidal anti-inflammatory drugs to prevent neuritis after RFA, and in most cases anticoagulation does not require cessation in the periprocedural period. With an aggressive lesioning strategy, sensory stimulation provides minimal therapeutic benefit, with weak, extrapolated evidence that motor stimulation can provide safety benefit. The cut-off to designate diagnostic or prognostic blocks as positive is most commonly set at 50%, with higher values not shown to improve outcomes for more definitive procedures; for therapeutic treatment outcomes, the evidence supports a lower threshold of ≥30% pain relief or meaningful benefit on non-pain outcomes (eg, opioid cessation) for designation of a positive response. For carefully selected patients with intra-articular SIJ complex pain based on controlled blocks who have failed conservative therapies, there is weak or very weak evidence that minimally invasive SIJ fusion can provide benefit for at least one year. Conclusions SIJ complex pain remains an underappreciated source of chronic low back pain, affecting between 15% and 30% of patients with axial pain predominantly below L5. Answers to many questions were limited by low-quality evidence, indicating the need for better research. SIJ complex pain is a multifarious condition (ie, pain can be from different portions of both the intra- and extra-articular components of the joint) for which an interdisciplinary, multimodal treatment plan can optimize treatment outcomes.