The Calpain-7 protease functions together with the ESCRT-III protein IST1 within the midbody to regulate the timing and completion of abscission.

The Endosomal Sorting Complexes Required for Transport (ESCRT) machinery mediates the membrane fission step that completes cytokinetic abscission and separates dividing cells. Filaments composed of ESCRT-III subunits constrict membranes of the intercellular bridge midbody to the abscission point. These filaments also bind and recruit cofactors whose activities help execute abscission and/or delay abscission timing in response to mitotic errors via the NoCut/Abscission checkpoint. We previously showed that the ESCRT-III subunit IST1 binds the cysteine protease Calpain-7 (CAPN7) and that CAPN7 is required for both efficient abscission and NoCut checkpoint maintenance (Wenzel et al., 2022). Here, we report biochemical and crystallographic studies showing that the tandem microtubule-interacting and trafficking (MIT) domains of CAPN7 bind simultaneously to two distinct IST1 MIT interaction motifs. Structure-guided point mutations in either CAPN7 MIT domain disrupted IST1 binding in vitro and in cells, and depletion/rescue experiments showed that the CAPN7-IST1 interaction is required for (1) CAPN7 recruitment to midbodies, (2) efficient abscission, and (3) NoCut checkpoint arrest. CAPN7 proteolytic activity is also required for abscission and checkpoint maintenance. Hence, IST1 recruits CAPN7 to midbodies, where its proteolytic activity is required to regulate and complete abscission.

NuRD complex recruitment to Thpok mediates CD4+ T cell lineage differentiation.

Although BTB-zinc finger (BTB-ZF) transcription factors control the differentiation of multiple hematopoietic and immune lineages, how they function is poorly understood. The BTB-ZF factor Thpok controls intrathymic CD4+ T cell development and the expression of most CD4+ and CD8+ lineage genes. Here, we identify the nucleosome remodeling and deacetylase (NuRD) complex as a critical Thpok cofactor. Using mass spectrometry and coimmunoprecipitation in primary T cells, we show that Thpok binds NuRD components independently of DNA association. We locate three amino acid residues within the Thpok BTB domain that are required for both NuRD binding and Thpok functions. Conversely, a chimeric protein merging the NuRD component Mta2 to a BTB-less version of Thpok supports CD4+ T cell development, indicating that NuRD recruitment recapitulates the functions of the Thpok BTB domain. We found that NuRD mediates Thpok repression of CD8+ lineage genes, including the transcription factor Runx3, but is dispensable for Cd4 expression. We show that these functions cannot be performed by the BTB domain of the Thpok-related factor Bcl6, which fails to bind NuRD. Thus, cofactor binding critically contributes to the functional specificity of BTB-ZF factors, which control the differentiation of most hematopoietic subsets.

Analysis of curcumin and piperine in biological samples by reversed-phase liquid chromatography with multi-wavelength detection.

Widely accessible food phytochemicals such as curcumin have been reported to have anti-inflammatory and anticarcinogenic properties. However, curcumin has poor absorption in the gut, and piperine has been of interest as a dietary compound that can enhance curcumin bioavailability. The aim of this study was to develop and optimize a technique using reversed-phase chromatography with multi-wavelength detection for the simultaneous measurement of curcumin and piperine in various biological matrices. Emodin was used as an internal standard. Protein precipitation and liquid-liquid extraction based on acetonitrile provided good recovery of these analytes. A 150 mm × 4.6 mm I.D. Luna C18 column was used under isocratic conditions to separate curcumin, piperine, and emodin with baseline resolution, and with good separation from other sample components, in as little as 4 min. The detection limits for curcumin and piperine were 3 and 7 ng/mL, respectively. This method has been used to quantitate these compounds in samples such as human intestinal epithelial cell lysates and mouse plasma or GI tissues in research aimed at examining the bioavailability of curcumin in the presence of piperine.

Regional anaesthesia practice for arteriovenous fistula formation surgery.

We conducted a survey and semi-structured qualitative interviews to investigate current anaesthetic practice for arteriovenous fistula formation surgery in the UK. Responses were received from 39 out of 59 vascular centres where arteriovenous access surgery is performed, a response rate of 66%. Thirty-five centres reported routine use of brachial plexus blocks, but variation in anaesthetic skill-mix and practice were observed. Interviews were conducted with 19 clinicians from 10 NHS Trusts including anaesthetists, vascular access and renal nurses, surgeons and nephrologists. Thematic analysis identified five key findings: (1) current anaesthetic practice showed that centres could be classified as 'regional anaesthesia dominant' or 'local anaesthesia/mixed'; (2) decision making around mode of anaesthesia highlighted the key role of surgeons as frontline decision makers across both centre types; (3) perceived barriers and facilitators of regional block use included clinicians' beliefs and preferences, resource considerations and patients' treatment preferences; (4) anaesthetists' preference for supraclavicular blocks emerged, alongside acknowledgement of varied practice; (5) there was widespread support for a future randomised controlled trial, although clinician equipoise issues and logistical/resource-related concerns were viewed as potential challenges. The use of regional anaesthesia for arteriovenous fistula formation in the UK is varied and influenced by a multitude of factors. Despite the availability of anaesthetists capable of performing regional blocks, there are other limiting factors that influence the routine use of this technique. The study also highlighted the perceived need for a large multicentre, randomised controlled trial to provide an evidence base to inform current practice.

Scoping review of mode of anaesthesia in emergency surgery.

BACKGROUND: Emergency surgery encompasses more than 50 per cent of the surgical workload; however, research efforts are disproportionally low. The mode of anaesthesia used during emergency surgery may affect outcomes, but the extent of research and the impact of the different modes of anaesthesia used are unclear. METHODS: MEDLINE and Embase were searched using scoping review methodology with a rapid systematic search strategy, identifying any study comparing locoregional (local, nerve block, subarachnoid, epidural) anaesthesia with general anaesthesia. All studies describing outcomes of emergency surgery with differing modes of anaesthesia were identified. Excluded were: studies published before 2003, studies enrolling patients aged less than 18 years and studies using sedation only. RESULTS: Forty-two studies were identified, describing 11 surgical procedures. Most publications were retrospective cohort studies (32). A very broad range of clinical and patient-reported outcomes were described, with wide variation in the outcomes reported in different studies. CONCLUSION: Reporting of mode of anaesthesia is inconsistent across different procedures and is often absent. There is a need for directed research efforts to improve the reporting standards of anaesthesia interventions, to understand the role of different modes of anaesthesia in specific emergency surgical procedures, and to standardize outcome reporting using core outcome sets.

ANTECEDENTES: La cirugía de urgencias constituye > 50% de la carga de trabajo quirúrgico, aunque los esfuerzos realizados en investigación en este ámbito son desproporcionadamente bajos. La modalidad de anestesia utilizada durante la cirugía de urgencias puede afectar a los resultados, sin embargo, la investigación realizada y el impacto de los diferentes tipos de anestesia utilizados no están claros. MÉTODOS: Se realizaron búsquedas en Medline y Embase utilizando una metodología enfocada a la recuperación de revisiones, con una estrategia de búsqueda sistemática rápida, identificando cualquier estudio que comparara la anestesia locorregional (local, bloqueo nervioso, subaracnoidea, epidural) con la anestesia general. Se identificaron todos los estudios que describían los resultados de la cirugía de urgencias con diferentes tipos de anestesia. Se excluyeron los estudios publicados antes del 2003, los estudios que reclutaron pacientes < 18 años y los estudios que solo usaron sedación. RESULTADOS: Se identificaron 42 estudios que describían 11 procedimientos quirúrgicos. La mayoría de publicaciones fueron estudios de cohortes retrospectivos (n = 32). Se describió una gama muy amplia de resultados clínicos y resultados aportados por los pacientes, con una amplia variación en los resultados de los diferentes estudios. CONCLUSIÓN: Los resultados publicados respecto a la modalidad de anestesia empleada en diferentes procedimientos quirúrgicos son inconsistentes, a menudo esta información está ausente y no se pueden establecer conclusiones sobre el impacto del tipo de anestesia en los resultados. Es necesario realizar esfuerzos dirigidos a la investigación para mejorar la notificación de los estándares de los procedimientos de anestesia, comprender el papel de los diferentes tipos de anestesia en los procedimientos quirúrgicos específicos de urgencias, y estandarizar la presentación de los resultados obtenidos utilizando un conjunto de datos principales.

Tissue Architectural Cues Drive Organ Targeting of Tumor Cells in Zebrafish.

Tumor cells encounter a myriad of physical cues upon arrest and extravasation in capillary beds. Here, we examined the role of physical factors in non-random organ colonization using a zebrafish xenograft model. We observed a two-step process by which mammalian mammary tumor cells showed non-random organ colonization. Initial homing was driven by vessel architecture, where greater numbers of cells became arrested in the topographically disordered blood vessels of the caudal vascular plexus (CVP) than in the linear vessels in the brain. Following arrest, bone-marrow- and brain-tropic clones exhibited organ-specific patterns of extravasation. Extravasation was mediated by ß1 integrin, where knockdown of ß1 integrin reduced extravasation in the CVP but did not affect extravasation of a brain-tropic clone in the brain. In contrast, silencing myosin 1B redirected early colonization from the brain to the CVP. Our results suggest that organ selectivity is driven by both vessel topography and cell-type-dependent extravasation.

Inhibition of HIV Maturation via Selective Unfolding and Cross-Linking of Gag Polyprotein by a Mercaptobenzamide Acetylator.

For HIV to become infectious, any new virion produced from an infected cell must undergo a maturation process that involves the assembly of viral polyproteins Gag and Gag-Pol at the membrane surface. The self-assembly of these viral proteins drives formation of a new viral particle as well as the activation of HIV protease, which is needed to cleave the polyproteins so that the final core structure of the virus will properly form. Molecules that interfere with HIV maturation will prevent any new virions from infecting additional cells. In this manuscript, we characterize the unique mechanism by which a mercaptobenzamide thioester small molecule (SAMT-247) interferes with HIV maturation via a series of selective acetylations at highly conserved cysteine and lysine residues in Gag and Gag-Pol polyproteins. The results provide the first insights into how acetylation can be utilized to perturb the process of HIV maturation and reveal a new strategy to limit the infectivity of HIV.

Use of Methohexital and Dexmedetomidine for Maintenance of Anesthesia in a Patient With Mitochondrial Myopathy: A Case Report.

Provision of anesthesia for patients with mitochondrial disorders is associated with a unique set of challenges. These disorders are rare, which complicates efforts to develop high quality, evidence-based guidelines to inform the perioperative management of those who suffer from them. Accordingly, case reports remain an important source of information regarding their care. Here we present the case of a 27-year-old female patient with mitochondrial myopathy and a history suggestive of malignant hyperthermia susceptibility who received general anesthesia for 2 consecutive surgeries. The induction agents included fentanyl, ketamine, and methohexital. The maintenance agents were methohexital, sufentanil, and dexmedetomidine.

Quantifying overlap between the Deepwater Horizon oil spill and predicted bluefin tuna spawning habitat in the Gulf of Mexico.

Atlantic bluefin tuna (Thunnus thynnus) are distributed throughout the North Atlantic and are both economically valuable and heavily exploited. The fishery is currently managed as two spawning populations, with the GOM population being severely depleted for over 20 years. In April-August of 2010, the Deepwater Horizon oil spill released approximately 4 million barrels of oil into the GOM, with severe ecosystem and economic impacts. Acute oil exposure results in mortality of bluefin eggs and larvae, while chronic effects on spawning adults are less well understood. Here we used 16 years of electronic tagging data for 66 bluefin tuna to identify spawning events, to quantify habitat preferences, and to predict habitat use and oil exposure within Gulf of Mexico spawning grounds. More than 54,000 km2 (5%) of predicted spawning habitat within the US EEZ was oiled during the week of peak oil dispersal, with potentially lethal effects on eggs and larvae. Although the oil spill overlapped with a relatively small portion of predicted spawning habitat, the cumulative impact from oil, ocean warming and bycatch mortality on GOM spawning grounds may result in significant effects for a population that shows little evidence of rebuilding.

Simulation of Tangential Excision: A Test for Construct Validity.

A foundational skill in burn surgery is tangential excision (TE). The purpose of this study was to develop a simulation model for TE, hypothesizing that simulation could be used in surgical training. TE simulation was created using the TE knife, foam, mineral oil, and base. Subjects, surgeons, or surgeons in training, were given a pre- and post-task questionnaire about experience with TE. Subjects were divided into three TE experience groups: novice--none, intermediate--some, and expert--TE in current or past practice. The task was to excise pre-marked rectangles, generating four excisional products (EPs). Evaluators blindly assessed performance by EP analysis using a novel scoring tool and reviewed videos using a modified objective structured assessment of technical skill (OSATS) rubric. Inter-rater reliabilities and P values were obtained, comparing Novice and Intermediate with Expert scores. Forty subjects completed the study: 16 were identified as TE novices, 17 as intermediates, and seven as experts. All EPs and videos were reviewed blindly by two evaluators using the EP scoring tool and OSATS methodology, respectively. Intraclass correlation coefficients were calculated to measure inter-rater reliabilities, which were acceptable (ICC => 0.42) for OSATS, time, and EP analysis: border and texture. Statistical differences between Novice and Expert scores were found (P < .0100, P < .0200, P < .0025, and P < .0005, respectively). Statistical differences between Intermediate and Expert scores were also found (P < .0100, P < .0200, P < .0100, and P < .0025, respectively). Post-simulation survey results showed experts 86% of the time agreeing or strongly agreeing that the simulation was similar to the clinical skin and 100% felt it would be a useful for training before clinical performance. Simulation for TE was successfully created to blindly discern level of TE experience. Participants agreed that simulation could play an essential role in burn surgical training.

Immediate permanent implant reconstruction following mastectomy with capsule preservation in patients with prior augmentation mammoplasty.

Prior breast augmentation in patients desiring post-mastectomy reconstruction provides a unique opportunity for capsular preservation and immediate, single-step implant reconstruction. We report a case series of a single-surgeon experience with immediate implant reconstruction after skin-sparing mastectomy in patients with prior subpectoral augmentation. Final implant volumes, complications, and outcomes were examined. Twenty patients (15 bilateral, total 35 breasts) were included. Eighteen (90%) patients were treated for cancer. Mean augmentation-to-reconstruction interval was 9 years (range, 3-19 years). Mean patient age was 45.1 years (range, 37-64 years). Eight patients (40%) received postoperative chemotherapy and two (10%) radiation. Mean mastectomy weight was 321 g. Mean weight of the implants removed was 346 g. Mean volume of new implants was 487 mL. All patients underwent capsulotomy (100% superior, 85% medial, 30% inferior, 5% lateral). Mean operative time was less than 1 hour for bilateral reconstruction. With average follow-up of 25.6 months, 2 patients were re-operated on for asymmetry (implant malposition, synmastia). Thirty-day complications included 1 implant loss due to infection, 1 drain placement with implant salvage, 1 hematoma requiring evacuation, and 1 cellulitis treated with antibiotics. There were no late complications and no capsular contractures. None have required further oncologic surgery. No cancer recurrences have been detected. In patients who desire prosthetic reconstruction similar to their original submuscular augmentation, capsule preservation and implant replacement with a larger prosthetic inserted within the old capsule is safe, fast, and aesthetically pleasing without compromising oncologic principles.

Sociodemographic factors associated with cervical cancer screening coverage and follow-up of high grade abnormal results in a population-based cohort.

INTRODUCTION: A cervical cytology based screening program is effective if there is regular screening of the 'at risk' population and close follow-up of those labeled abnormal. METHODS: This is a population cohort study of women between 20-69 year old who were eligible in Ontario from 2008-2010. We used administrative data to evaluate the rates of cervical cancer screening and follow-up of high grade Pap tests. Variation in cervical cytology coverage and follow-up of high grade abnormal results are associated with age, area level income and health region. Multivariate logistic regression was used to identify independent factors associated with screening and followup. RESULTS: 3.7million women were eligible for screening of which 72% had a Pap smear in the prior 3years. These rates varied by age, income and region (p<0.0001). Women residing in the lowest income neighborhoods were half as likely to be screened (p<0.0001). 83% of those with an high grade intraepithelial lesion Pap test result had follow-up with colposcopy or treatment within 6months and this varied by year, age, income and region (p<0.0001). CONCLUSIONS: Despite universal health coverage, cervical cancer screening rates are suboptimal with older and low income women being at greatest risk. Follow-up among women with high grade abnormal tests is mediocre at 3months and acceptable at 6months. Novel models of cervical cancer screening program implementation are needed to address these inadequacies.

The use of autologous platelet-leukocyte-enriched plasma to minimize drain burden and prevent seroma formation in latissimus dorsi breast reconstruction.

INTRODUCTION: Seromas and drains are major sources of morbidity associated with latissimus dorsi breast reconstruction. Our goal was to look at an autologous platelet-leukocyte-enriched plasma spray and to assess its efficacy in reducing drain burden and seroma formation. METHODS: We performed a single surgeon, patient-controlled, blinded study on bilateral latissimus dorsi breast reconstruction patients in which we applied autologous platelet-leukocyte-enriched plasma to one side and measured drain amounts, time to drain removal, and seroma rate. RESULTS: Twelve patients were included in this study. The average age was 41.1 years, and the average body mass index was 21.6 kg/m. Average volume of drain output showed neither difference (789 mL spray side vs. 790 mL control side) nor average time to drain removal (11.83 days spray side vs. 11.5 days control side). There were 2 complications reported: 1 hematoma (8.33%) and 1 seroma (8.33%) that required aspiration in a postoperative visit. CONCLUSIONS: It appears after 12 patients that there is no demonstrable difference regarding drain output, time to drain removal, or seroma incidence between the study and the control group. We feel a larger study population would add power and confirm these findings.

The scarless latissimus dorsi flap for full muscle coverage in device-based immediate breast reconstruction: an autologous alternative to acellular dermal matrix.

BACKGROUND: Thin patients have fewer autologous options in postmastectomy reconstruction and are frequently limited to device-based techniques. The latissimus dorsi flap remains a viable option with which to provide autologous coverage, although for certain patients the donor scar can be a point of contention. The scarless latissimus dorsi flap is a way of mitigating these concerns. The authors present their 6-year single-surgeon experience with scarless latissimus dorsi flap reconstruction. METHODS: A retrospective review of scarless latissimus dorsi flap reconstruction was performed. Charts from 2003 to 2009 were queried for demographic characteristics, nonoperative therapies, and short- and long-term complications. Results were compared with historical data. RESULTS: Thirty-one patients with 52 flaps were identified. Fifty-one flaps were immediate reconstructions, with an average age of 47 years and body mass index of 22.8 kg/m. Thirteen patients were treated with chemotherapy and four were irradiated, two preoperatively. The single drain was removed on average at 21 days. Complications included three hematomas (5.8 percent), two capsular contractures (3.8 percent), and two infections (3.8 percent). Average time to secondary reconstruction was 143 days. There were five unplanned revisions (9.6 percent). There were no flap failures or tissue expander losses. CONCLUSIONS: The scarless latissimus dorsi flap is an effective method for providing durable homogenous device coverage in the thinner patient (body mass index <24). With the advent of acellular dermal matrices, device coverage has been made simpler, but this comes at a cost. Coverage is thin, the matrix is not initially vascularized, and products are expensive. For these reasons, use of the scarless latissimus dorsi flap is an excellent alternative, particularly in the patient with a low body mass index. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.(Figure is included in full-text article.).

Fibrocartilage tissue engineering: the role of the stress environment on cell morphology and matrix expression.

Although much is known about the effects of uniaxial mechanical loading on fibrocartilage development, the stress fields to which fibrocartilaginous regions are subjected to during development are mutiaxial. That fibrocartilage develops at tendon-to-bone attachments and in compressive regions of tendons is well established. However, the three-dimensional (3D) nature of the stresses needed for the development of fibrocartilage is not known. Here, we developed and applied an in vitro system to determine whether fibrocartilage can develop under a state of periodic hydrostatic tension in which only a single principal component of stress is compressive. This question is vital to efforts to mechanically guide morphogenesis and matrix expression in engineered tissue replacements. Mesenchymal stromal cells in a 3D culture were exposed to compressive and tensile stresses as a result of an external tensile hydrostatic stress field. The stress field was characterized through mechanical modeling. Tensile cyclic stresses promoted spindle-shaped cells, upregulation of scleraxis and type one collagen, and cell alignment with the direction of tension. Cells experiencing a single compressive stress component exhibited rounded cell morphology and random cell orientation. No difference in mRNA expression of the genes Sox9 and aggrecan was observed when comparing tensile and compressive regions unless the medium was supplemented with the chondrogenic factor transforming growth factor beta3. In that case, Sox9 was upregulated under static loading conditions and aggrecan was upregulated under cyclic loading conditions. In conclusion, the fibrous component of fibrocartilage could be generated using only mechanical cues, but generation of the cartilaginous component of fibrocartilage required biologic factors in addition to mechanical cues. These studies support the hypothesis that the 3D stress environment influences cell activity and gene expression in fibrocartilage development.

Midterm results of adjunctive neck therapies performed during elective infrarenal aortic aneurysm repair.

OBJECTIVE: This study evaluated the durability of adjunctive endovascular neck procedures, including aortic cuffs, Palmaz stents (Cordis, Miami Lakes, Fla), and high-pressure balloon angioplasty, at managing intraoperative proximal neck complications during endovascular aortic aneurysm repair (EVAR). METHODS: This was a single-center retrospective review of EVARs. The primary outcome variable studied was survival free of a graft-related event (GRE). GRE was defined by the occurrence of one of the following: type I endoleak, sac enlargement, aneurysm rupture, death, or procedure related to the aortic neck. These outcome variables were assessed relative to the preoperative anatomic neck variables (neck length, diameter, degree of angulation, degree of circumferential thrombus, and presence of conicity), procedural variables (manufacturing type of graft, use of a Palmaz stent), and patient characteristics (age and presence of medical comorbidities). Outcomes were assessed by t tests, Pearson χ(2), and Kaplan-Meier analysis, when appropriate. RESULTS: A total of 174 EVARs performed between January 2005 and December 2007 were evaluated. Fifty-six adjunctive procedures were performed, with a 97% primary-assisted exclusion rate. Patients who received an adjunctive therapy had similar freedom from a GRE compared with EVARs that did not require adjunctive therapy (35.5 ± 2.6 vs 34.8 ± 1.5 months, P = .31, log-rank test). Subset analysis identified a significant association between Palmaz stent placement at the time of EVAR and decreased freedom from GREs (hazard ratio, 2.87; 95% confidence interval, 1.21-6.77; P = .02). CONCLUSIONS: Midterm results suggest that adjunctive therapies to manage intraoperative proximal neck complications do not compromise durability. The subset of patients requiring aortic neck Palmaz stent placement at the time of EVAR are among those at highest risk for subsequent GRE.

The rising prevalence and changing age distribution of multiple sclerosis in Manitoba.

OBJECTIVE: Several studies suggest an increasing prevalence of multiple sclerosis (MS) in Canada. We aimed to validate a case definition for MS using administrative health insurance data, and to describe the incidence and prevalence of MS in Manitoba, Canada. METHODS: We used provincial administrative claims data to identify persons with demyelinating disease using International Classification of Diseases 9/10 codes and prescription claims. To validate the case definition, questionnaires were mailed to 2,000 randomly selected persons with an encounter for demyelinating disease, requesting permission for medical records review. We used diagnoses abstracted from medical records as the gold standard to evaluate candidate case definitions using administrative data. RESULTS: From 1984 to 1997, cases of MS using claims data were defined as persons with > or = 7 medical contacts for MS. From 1998 onward, cases were defined as persons with > or = 3 medical contacts. As compared to medical records, this definition had a positive predictive value of 80.5% and negative predictive value of 75.5%. From 1998 to 2006, the average age- and sex-adjusted annual incidence of MS per 100,000 population was 11.4 (95% confidence interval [CI] 10.7-12.0). The age-adjusted prevalence of MS per 100,000 population increased from 32.6 (95% CI 29.4-35.8) in 1984 to 226.7 (95% CI 218.1-235.3) in 2006, with the peak prevalence shifting to older age groups. CONCLUSION: The prevalence of multiple sclerosis (MS) in Manitoba is among the highest in the world. The rising prevalence with minimally changing incidence suggests improving survival. This study supports the use of administrative data to develop case definitions and further define the epidemiology of MS.