AbstractToxic shock syndrome toxin‐1 (TSST‐1) is a potent superantigen produced by Staphylococcus aureus. In addition to menstrual and nonmenstrual toxic shock syndromes, TSST‐1 is also implicated in the immunopathogenesis of pneumonia, infective endocarditis, neonatal exanthematous disease, and atopic dermatitis among others. Superantigens first bind to major histocompatibility complex (MHC) class II molecules and then activate a large proportion of T cells by cross‐linking their T cell receptor. As binding to MHC class II molecules is a critical step in the robust activation of the immune system by TSST‐1 and other superantigens, polymorphic variations between different HLA‐DR alleles could potentially influence the magnitude of immune activation and immunopathology caused by TSST‐1. As TSST‐1 is highly toxic to humans and given that multiple variations of alleles of HLA‐DR and HLA‐DQ are expressed in each individual, it is difficult to determine how HLA‐DR polymorphisms quantitatively and qualitatively impact immune activation caused by TSST‐1 in humans. However, such investigations can be conducted on transgenic mice lacking all endogenous MHC class II molecules and expressing specific HLA class II alleles. Therefore, transgenic mice expressing different HLA‐DRB1 alleles (HLA‐DRB1*15:01, HLA‐DRB1*15:02, HLA‐DRB1*03:01, HLA‐DRB1*04:01), and sharing HLA‐A1*01:01 chain, were systemically challenged with purified TSST‐1 and multiple immune parameters were assessed. Among the HLA‐DR alleles, mice expressing HLA‐DRB1*15:01 allele elicited a significantly higher serum cytokine/chemokine response; greater splenic T cell expansion and most severe organ pathology. Our study highlights the potential utility of human leukocyte antigen (HLA) transgenic mice in understanding the impact of HLA polymorphisms on the outcomes of diseases caused by TSST‐1 and other superantigens.
Meal replacements followed by topiramate for the treatment of adolescent severe obesity: A pilot randomized controlled trial
ObjectiveTo assess the safety and efficacy of short‐term meal replacement therapy followed by topiramate for body mass index (BMI) reduction in adolescents with severe obesity.MethodsAdolescents (ages 12–18 years) with severe obesity (BMI ≥1.2 times the 95th percentile or BMI ≥35 kg/m2) were recruited for this double‐blind, randomized, placebo‐controlled trial. Participants completed 4 weeks of meal replacement therapy followed by randomization (1:1) to either 24 weeks of topiramate 75 mg/day or placebo. Mean changes were compared between groups.ResultsThirty adolescents (mean age 15.2 ± 1.7 years, mean BMI 40.3 ± 4.6 kg/m2) completed the meal replacement phase and were randomized; 21 completed the study. The difference in mean percent change in BMI between the topiramate and placebo groups was not significant (−1.9%; 95% CI: −5.2% to +1.5%; P = 0.291). Significant improvements in visceral fat and very‐low‐density lipoprotein cholesterol were observed in the topiramate compared with the placebo group. There were no concerning changes in neurocognitive function or bone health.ConclusionsIn this pilot study, 4 weeks of meal replacement therapy followed by 24 weeks of low‐dose topiramate compared with meal replacement therapy alone did not result in significant BMI reduction for adolescents with severe obesity.
P4‐129: Predicting Alzheimer’s Disease in Asymptomatic Subjects Using a Hierarchical Hidden Markov Model, A Wordlist Memory Task, and the Mayo Aging Study
AimsThe International Collaboration on Cancer Reporting (ICCR) is a not‐for‐profit organization formed by the Royal Colleges of Pathologists of Australasia and the United Kingdom, the College of American Pathologists, the Canadian Association of Pathologists–Association Canadienne des Pathologists in association with the Canadian Partnership Against Cancer, and the European Society of Pathology. Its goal is to produce standardized, internationally agreed, evidence‐based datasets for use throughout the world.Methods and resultsThis article describes the development of a cancer dataset by the multidisciplinary ICCR expert panel for the reporting of thymic epithelial tumours. The dataset includes ‘required’ (mandatory) and ‘recommended’ (non‐mandatory) elements, which are validated by a review of current evidence and supported by explanatory text. Seven required elements and 12 recommended elements were agreed by the international dataset authoring committee to represent the essential information for the reporting of thymic epithelial tumours.ConclusionsThe use of an internationally agreed, structured pathology dataset for reporting thymic tumours provides all of the necessary information for optimal patient management, facilitates consistent and accurate data collection, and provides valuable data for research and international benchmarking. The dataset also provides a valuable resource for those countries and institutions that are not in a position to develop their own datasets.
What Factors Influence the Outcome of Surgically Treated Soft Tissue Sarcomas of the Hand and Wrist?
Background: Soft tissue sarcomas (STS) of the hand are exceedingly rare. The aim of this study was to review our institution’s experience with STS of the hand to identify factors affecting outcomes and survivorship. Methods: We retrospectively reviewed the records of 46 hand STS treated with definitive surgery at our institution between 1992 and 2013. Pertinent demographics as well as information regarding the surgical procedure, and disease status at latest follow-up were reviewed. Mean age at diagnosis was 38 years with a mean follow-up of 5 years. Results: The most common tumor subtypes were epithelioid (n = 10) and synovial sarcoma (n = 8). Sixty-one percent were superficial in location. Thirty-three patients had had a nononcologic resection prior to definitive surgical treatment at our institution. Ultimately, negative margins were obtained in all cases. Local recurrence was observed in 5 patients and distant metastases in 14 patients. Tumor sizes ≥2 cm, American Joint Committee on Cancer (AJCC) grade, and depth of the tumor were found to adversely affect the outcome in terms of disease-free and overall survival. Reexcision of an inadvertently excised tumor at an outside institution did not adversely affect the outcome. The 10-year overall and disease-free survival was 72% and 63%. Conclusions: Local recurrence after a wide excision was observed infrequently; however, distant disease was relatively common. Tumors with a size ≥2 cm were associated with a worse disease-free and overall survival, highlighting the aggressive nature of these tumors.
Cutaneous nodular fasciitis with genetic analysis: a case series
Nodular fasciitis is a benign self‐limited myofibroblastic neoplasm, which usually involves the upper extremities and trunk of young patients. These tumors have been shown to harbor a translocation involving the MYH9 and USP6 genes, leading to overexpression of the latter. We report seven cases of nodular fasciitis with cutaneous presentations. All cases involved the dermis, with six involving the superficial subcutis, and one auricular tumor extending into cartilage. All cases showed USP6 rearrangement by fluorescence in situ hybridization; in two of three cases, the characteristic MYH9‐USP6 fusion was shown by RT‐PCR. All patients underwent conservative resection. Nodular fasciitis is an uncommon mesenchymal neoplasm that can occasionally present in superficial locations and is sometimes mistaken for a malignant process. Molecular testing can be useful to distinguish this entity from other cutaneous spindle cell tumors.
No Evidence That Genetic Variation in the Myeloid-Derived Suppressor Cell Pathway Influences Ovarian Cancer Survival
Knowledge Gaps in Cardiovascular Care of Older Adults: A Scientific Statement from the American Heart Association, American College of Cardiology, and American Geriatrics Society: Executive Summary
The incidence and prevalence of most cardiovascular disorders increase with age, and cardiovascular disease ( CVD ) is the leading cause of death and major disability in adults aged 75 and older. Despite the effect of CVD on quality of life, morbidity, and mortality in older adults, individuals aged 75 and older have been markedly underrepresented in most major cardiovascular trials, and virtually all trials have excluded older adults with complex comorbidities, significant physical or cognitive disabilities, frailty, or residence in nursing homes and assisted living facilities. As a result, current guidelines are unable to provide evidence‐based recommendations for diagnosis and treatment of older adults typical of those encountered in routine clinical practice. The objectives of this scientific statement are to summarize current guideline recommendations as they apply to older adults, identify critical gaps in knowledge that preclude informed evidence‐based decision‐making, and recommend future research to close existing knowledge gaps. To achieve these objectives, a detailed review was conducted of current American College of Cardiology/American Heart Association ( ACC / AHA ) and American Stroke Association ( ASA ) guidelines to identify content and recommendations that explicitly targeted older adults. A pervasive lack of evidence to guide clinical decision‐making in older adults with CVD was found, as well as a paucity of data on the effect of diagnostic and therapeutic interventions on outcomes that are particularly important to older adults, such as quality of life, physical function, and maintenance of independence. Accordingly, there is a critical need for a multitude of large population‐based studies and clinical trials that include a broad spectrum of older adults representative of those seen in clinical practice and that incorporate relevant outcomes important to older adults in the study design. The results of these studies will provide the foundation for future evidence‐based guidelines applicable to older adults and enhance person‐centered care of older individuals with CVD in the United States and around the world.
Introduction of Adipose-Derived Stem Cells in Decellularized Nerve Allografts
Objective: Successful repair of segmental peripheral nerve defects remains a clinical challenge. The current clinical gold standard for such injuries is to use an autologous nerve graft, but this creates donor site morbidity with loss of sensation and potential scarring. Processed nerve allografts have been used to bridge segmental nerve gaps experimentally and clinically. However, in large nerve defects, functional outcomes are not comparable with autograft reconstruction yet; the longer the nerve gap, the poorer the outcome. Nerve architecture and the extracellular matrix (ECM) are preserved after processing; however, all cellular material including Schwann cells and axons are removed. The addition of supporting cells has been proposed to improve the decellularized allograft. Adipose-Derived Mesenchymal Stem Cells (AMSC) can potentially provide the necessary support for nerve regeneration due to local production of essential growth factors. While the mechanisms underlying the neurotrophic potential of AMSC remains unknown, it is postulated that the remaining ECM still has biological activity that influences the AMSC and their differentiation. Therefore, the purpose of this study was to quantitate the changes in gene expression profiles of the cells and quantify the actual produced growth factors after seeding the allograft with AMSC in vitro. Method: A total of 35 human nerve allografts were decellularized and seeded with human AMSC. At each time point (1, 3, 14, 21, and 28 days), total RNA was extracted, reverse transcribed into complementary DNA (cDNA), and quantitative reverse transcription–polymerase chain reaction (qRT-PCR) was performed in combination with gene specific assays for genes essential for nerve regeneration including nerve growth factor (NGF), Brain-derived neurotrophic factor (BDNF), pleiotrophin vascular endothelial growth factor (PTN VEGF), and growth associated protein 43 (GAP43).Additional genes were analyzed to map AMSC characteristics including proliferation, apoptosis, myelinization, and ECM molecules. Production of growth factors was evaluated and quantified using enzyme-linked immunosorbent assay (ELISA). All samples were analyzed in triplicates and data were compared with AMSC cultured in media only. Results: Semiquantitative RT-PCR analysis showed that the interaction of the processed allograft and AMSC enhanced the expression of the neurotrophic factors NGF, BDNF, and GAP43. The expression of the angiogenic molecules, vascular endothelial growth factor A (VEGF-A) was also increased and remained significantly elevated at 28 days post seeding. Analysis of ECM-related gene expression showed that laminin subunit beta-2 (LAMB2), collagen type I alpha 1 (COL1A1), collagen type III alpha 1 (COL3A1), fibulin 1 (FBLN1), were significantly elevated until 21 days post seeding while after 28 days, these levels were normalized. Angiogenic factor cluster of differentiation 31 (CD31) and neurotrophic factor PTN expression were down regulated in the seeded cells. Quantitative results of the ELISA analysis are pending. We anticipate differences in growth factor levels released by the seeded allograft compared with the control expression levels. Conclusion: This study demonstrates that the remaining ECM of the decellularized nerve allograft has a stimulating effect on AMSC. Upon the seeding, secretion of neurotrophic and angiogenic factors were triggered; the cells cultured on the allograft showed enhanced levels of neurotrophic genes. This is hypothesized to be a consequence of specific cell-ECM interactions within the allograft. The combination of patient’s own easily accessible, abundant supply of stem cells harvested from adipose tissue and the readily available processed nerve allograft is potentially a promising method for individualized peripheral nerve repair.
Surgical Revascularization of Cryopreserved Allografts
Objective: The treatment of segmental bone defects remains challenging as complications frequently occur with the currently available methods, including vascularized autograft, prosthetic replacement, bone transport, and cryopreserved bone allograft (CBA). Although the use of CBA is comparatively simple, it lacks donor site morbidity and provides immediate stability; however, the grafts remain largely necrotic, resulting in high failure rates due to nonunion, infection, and stress fractures. Revitalizing the CBA has the potential to solve these problems. Previous studies in small animal models have shown the use of surgical revascularization to induce neoangiogenesis and improve bone viability in the CBA. The purpose of this study is to investigate if surgical revascularization enhances bone circulation and bone remodeling in a tibial defect orthotopic reconstruction model, placing a cryopreserved allograft in a Yucatan mini pig. Methods: Cryopreserved tibial bone allografts were transplanted in swine leukocyte antigen (SLA)-type-mismatched Yucatan mini pigs after creating a 3.5-cm segmental bone defect in the tibia. The anterior tibial arteriovenous bundle (AV-bundle) was inserted into the intramedullary canal. Eight pigs received a patent AV-bundle (revascularized group), 8 pigs received a proximally ligated AV-bundle (control group), and the contralateral side was used as an untreated control. The graft was fixated with a locking compression plate to provide a weightbearing construction. After 20 weeks, the pigs were killed and the tibia was removed and analyzed. Neoangiogenesis was evaluated by quantifying vascular volumes using the microcomputed tomography. Bone remodeling was measured by quantitative histomorphometry and micro-computed tomography. Results: Seven AV-bundles in the revascularized group were patent and 1 bundle was thrombosed due to partial dislocation of the graft. Total vascular volume was higher in the revascularized allografts (127 mm 3 ) compared with both the control group (40 mm 3 , P = .003) and the contralateral side (29 mm 3 P = .000). All patent bundles showed neovascularization extending into the cortical bone. Revascularized allografts had increased bone remodeling in the inner cortical area of the graft compared with the non-revascularized grafts (bone formation rate: 381 ± 60 µm 3 /µm 3 /year vs 299 ± 143 µm 3 /µm 3 /year, P = .05). In both the revascularized group and the control group, the bone formation rate exceed the contralateral side: In the revascularized grafts, the bone formation was 305% of contralateral side, and in the non-revascularized grafts, the bone formation was 179% of the contralateral side. There was no statistical significant difference in outer cortical bone formation between the revascularized and the non-revascularized allografts. Conclusion: Surgical revascularization of porcine tibial CBAs by implantation of an AV-bundle creates an enhanced autogenous neoangiogenic circulation and accelerates active bone formation.