The Halo Density Profiles with Non-Standard N-body Simulations

We propose a new numerical procedure to simulate a single dark halo of any size and mass in a hierarchical framework coupling the extended Press-Schechter formalism (EPSF) to N-body simulations. The procedure consists of assigning cosmological initial conditions to the particles of a single halo with a EPSF technique and following only the dynamical evolution using a serial N-body code. The computational box is fixed with a side of $0.5 h^{-1}$ Mpc. This allows to simulate galaxy cluster halos using appropriate scaling relations, to ensure savings in computing time and code speed. The code can describe the properties of halos composed of collisionless or collisional dark matter. For collisionless Cold Dark Matter (CDM) particles the NFW profile is reproduced for galactic halos as well as galaxy cluster halos. Using this numerical technique we study some characteristics of halos assumed to be isolated or placed in a cosmological context in presence of weak self-interacting dark matter: the soft core formation and the core collapse. The self-interacting dark matter cross section per unit mass is assumed to be inversely proportional to the particle collision velocity: $\sigma/m_{x} \propto 1/v$.Comment: Accepted for publication in MNRAS (2 figures added

DIEP flap perfusion assessment using microdialysis versus Doppler ultrasonography. A comparative study

BackgroundThe increasing number of buried free-tissue transfer procedures and the need for an objective method to evaluate vascular complications of free flaps has led to the development of new technologies. Microdialysis has been used to monitor free flaps using interstitial biological markers. Previous uses mainly focused on muscular flaps. Our aim is to compare external Doppler ultrasonography (EDU) evaluation versus microdialysis in the early follow-up of adipocutaneous flaps, and propose an efficient postoperative monitoring protocol. MethodsWe retrospectively assessed 68 consecutive DIEP flaps (50 patients) performed between January 2019 and March 2021. All flaps received standardized post-operative monitoring using clinical signs, EDU and microdialysis. Glucose and lactate concentrations were assessed using glucose 6 mmol/L as ischemic trend thresholds. We calculated Glucose/Lactate ratio as a new parameter for the assessment of flap viability. ResultsAmong all the 68 flaps, two flaps returned to the operative theater when a combination of unsatisfactory microdialysis values and clinical/EDU signs identified vascular impairment; only one developed total flap necrosis. Reoperation rate was 2.94% with an overall flap success rate of 98.53%. External Doppler ultrasonography had 100% sensitivity and 82% specificity, while microdialysis had 100% sensitivity and 100% specificity. ConclusionsMicrodialysis values proved flap viability sooner than external Doppler ultrasonography, making it an excellent tool for post-operative monitoring. With the appropriate thresholds for glucose and lactate concentrations, and glucose/lactate ratio used as a new parameter, it can help potentially avoiding unnecessary re-explorations, and reducing flap ischemia times

Free-style technique versus computed tomographic angiography-guided perforator selection in deep inferior epigastric perforator flap harvest: a prospective clinical study

Background: Computed tomographic angiography (CTA) is the preferred diagnostic tool in preoperative deep inferior epigastric perforator (DIEP) flap assessment, though some surgeons prefer approaching perforator selection with intraoperative findings alone. Methods: This prospective observational study conducted between 2015 and 2020 assessed our intraoperative decision-making "free-style" technique for DIEP flap harvest. Any patient with indication for immediate or delayed breast reconstruction using abdominally based flaps and who received preoperative CTA was enrolled. Only unilateral cases performed by the same surgeon were considered. Allergy to iodine-based contrast media, renal impairment and claustrophobia were other exclusion criteria. Primary endpoint consisted in comparing operative times and complication rates between free-style technique and CTA-guided approach. Secondary endpoints included evaluation of agreement rate between intraoperative findings and CTA, and identification of variables affecting operative time and complication rate. Demographics, surgical information, agreement versus non-agreement and complications were collected. Results: Starting from 206 patients, 100 were enrolled. Fifty were assigned to Group A, receiving DIEP flap with free-style technique. The other 50 were assigned to Group B, receiving DIEP flap with CTA-guided perforators selection. Study groups' demographics were homogenous. Operative time was statistically lower (p = .036) in free-style group (252.4 ± 44.77 min vs. 265.6 ± 31.67 min). Complication rates were higher in CTA-guided group (10% vs. 2%) though this was not significant (p = .092). Overall agreement rate in dominant perforator selection between intraoperatively and CTA-based assessment was 81%. Multiple regression analysis showed no variable increased complication rate, though CTA-guided approach, BMI > 30 and harvesting more than one perforator were respectively associated with B-coefficient of 17.391 (2.430-32.351, 95% CI) [p = .023], 3.50 (0.640-6.379, 95% CI) [p = .017] and 18.887 (6.232-31.542, 95% CI) [p = .004], predicting increased operative time. Conclusions: The free-style technique proved to be a useful tool for guiding DIEP flap harvest with good sensibility in detecting the dominant perforator suggested by CTA without statistically increasing surgery duration and complications

Determining Breast Implant Prevalence. A Population Study of Italian Chest Radiographs

Background Current breast implant prevalence within the general population remains elusive. An accurate prevalence is critical to serve as the denominator for any assessment of breast implant-related complication. The purpose of this manuscript is to assess this prevalence in women aged 20-70 years in Italy.Materials and Methods Eight reviewers, demonstrating a mean sensitivity of 87.0% and specificity of 97.0%, were recruited for retrospective identification of implants on chest radiographs from a tertiary academic hospital in a major urban setting. Three final reviewers were selected, and they assessed all eligible chest radiographs collected between January and December 2019. The hospital-based population was compared to epidemiological data at a local, regional and national level to demonstrate homogeneity of age structures using the phi correlation coefficient.Results We identified 3,448 chest X-rays which yielded 140 implants, with an overall prevalence of 4.1% for women aged 20-70. Implants were bilateral in 76% of cases and unilateral in 24%. They were placed cosmetically in 47.1% cases and used for reconstruction in 52.9% cases. Phi correlation coefficient found no differences across hospital-based, local, regional and national populations.Conclusion A validated method was performed to estimate implant prevalence from an academic hospital in a major urban setting at 4.1% and was used to estimate national prevalence in Italy. The implications of this epidemiologic study may reach across national borders for improved understanding of breast implant epidemiology and in predicting the total number of patients within a given population that may be affected by device complications

Study of the effect of different breast implant surfaces on capsule formation and host inflammatory response in an animal model

Background: Breast implants are biomaterials eliciting a physiological and mandatory foreign body response. Objectives: The authors designed an animal study to investigate the impact of different implant surfaces on the formation of the periprosthetic capsule, the inflammatory response, and the cellular composition. Methods: The authors implanted 1 scaled-down version of breast implants by different manufactures on 70 female Sprague Dawley rats. Animals were divided into 5 groups of 14 animals. Group A received a smooth implant (Ra ≈ 0.5 µm) according to the ISO 14607-2018 classification, Group B a smooth implant (Ra ≈ 3.2 µm), Group C a smooth implant (Ra ≈ 5 µm), Group D a macrotextured implant (Ra ≈ 62 µm), and Group E a macrotextured implant (Ra ≈ 75 µm). At 60 days, all animals received a magnetic resonance imaging (MRI), and 35 animals were killed and their capsules sent for histology (capsule thickness, inflammatory infiltrate) and immunohistochemistry analysis (cellular characterization). The remaining animals repeated the MRI at 120 days and were killed following the same protocol. Results: MRI showed a thinner capsule in the smooth implants (Groups A-C) at 60 days (P < .001) but not at 120 days (P = .039), confirmed with histology both at 60 days (P = .005) and 120 days (P < .001). Smooth implants (Groups A-C) presented a mild inflammatory response at 60 days that was maintained at 120 days and a high M2-Macrophage concentration (anti-inflammatory). Conclusions: Our study confirms that smooth implants form a thinner capsule, inferior inflammatory infiltrate, and a cellular composition that indicates a mild host inflammatory response. A new host inflammatory response classification is elaborated classifying breast implants into mild, moderate, and high

Halpha rotation curves: the soft core question

We present high resolution Halpha rotation curves of 4 late-type dwarf galaxies and 2 low surface brightness galaxies (LSB) for which accurate HI rotation curves are available from the literature. Observations are carried out at Telescopio Nazionale Galileo (TNG). For LSB F583-1 an innovative dispersing element was used, the Volume Phase Holographic (VPH) with a dispersion of about 0.35 A/pxl. We find good agreement between the Halpha data and the HI observations and conclude that the HI data for these galaxies suffer very little from beam smearing. We show that the optical rotation curves of these dark matter dominated galaxies are best fitted by the Burkert profile. In the centers of galaxies, where the N-body simulations predict cuspy cores and fast rising rotation curves, our data seem to be in better agreement with the presence of soft cores.Comment: Accepted for Publication in ApJ with minor changes require

History of breast implants. Back to the future

Modern breast implants are a staple of plastic surgery, finding uses in esthetic and reconstructive procedures. Their history began in the 1960s, with the first generation of smooth devices with thick silicone elastomer, thick silicone gel, and Dacron patches on the back. They presented hard consistency, high capsular contracture rates and the patches increased the risk of rupture. In the same decade, polyurethane coating of implants was implemented. A sec- ond generation was introduced in the 1970s with a thinner shell, less viscous gel filler and no patches, but increased silicone bleed- through and rupture rates. The third generation, in the early 1980s, featured implants with a thicker multilayered elastomer shell rein- forced with silica to reduce rupture risk and prevent silicone bleed- through. A fourth generation from the late 1980s combined thick outer elastomer shells, more cohesive gel filler, and implemented for the first-time outer shell texturing. In the early 1990s, the fifth generation of devices pioneered an anatomical shape with highly cohesive form-stable gel filler and a rough outer shell surface. Sur- face texturing was hampered by the discovery of Breast Implant Associated-Anaplastic Large Cell Lymphoma and its link with tex- tured devices. From the 2010s, we have the era of the sixth gen- eration of implants, featuring innovations regarding the surface, with biomimetic surfaces, more resistant shells and variations in gel consistency. The road to innovation comprises setbacks such as the FDA moratorium in 1992, the PIP scandal, the Silimed CE mark temporary suspension and the FDA-requested voluntary recall of the Allergan BIOCELL implants

From breast implant to rough implant associated-ALCL (RIA-ALCL)

The FDA (Silver Spring, MD, USA) announcement in 2011 heralded the starting point of global alertness regarding the possible connection of breast implants with a rare form of a non-Hodgkin lymphoma: anaplastic large cell lymphoma (ALCL). Sporadic case reports, preliminary case review studies, and manuscripts proposing diagnostic, staging and treatment protocols, or etiopathogenesis theories filled the scientific lit- erature. In 2016, this new pathology was added as a distinct entity in the update to the World Health Organization (Geneva, Switzerland) classification of lymphoid neoplasms and now in- cludes over 420 cases in Europe1 and 1148 cases worldwide according to BIA-ALCL Global Network and EURAPS Scientific Committee on Device Safety and Development. The interest of scientific research towards this pathology increased year by year and was further boosted by a recent increase in media at- tention; therefore, various names or abbreviations have been given to it. The first attempt to give it a name was made by Story et al. in 2013, who referred to it as implant-associated ALCL, or iALCL.2 This was replaced the same year by Thompson et al. with the most widely accepted way of referring to it: breast im- plant–associated ALCL (BIA-ALCL).3 During the last 10 years, since the first FDA announce- ment, BIA-ALCL has been at the forefront of numerous dis- cussions in conferences around the world and hearings by regulatory authorities such as the FDA, the French National Security Agency of Medicines and Health Products (Issy-les- Moulineaux, France), the Therapeutic Goods Administration (Woden, Australia), and so on. In the past decade, as aware- ness increased toward implants and their connection with ALCL, numerous case reports were presented in which ALCL arose in sites other than the breast. This includes the gluteal region from textured gluteal implants, pacemakers, orthopedic implants for tibial and shoulder repair, dental implants, chest ports, and even bariatric surgery devices.4 Some patients have developed a misplaced fear of all breast implants, but to date no BIA-ALCL case has been published or officially regis- tered with a clear history of only smooth implants; therefore it can be considered as a pathology connected to textured im- plant surfaces only. Additionally, the Scientific Committee on Health, Environmental and Emerging Risks (Brussels, Belgium) recently expressed their final opinion on the safety of breast implants in relation to ALCL and concluded the existence of a causal relationship between textured breast implants and BIA-ALCL, indicating the texturization as the risk factor.5 We believe the current definition of “breast implant associated” is misleading because it suggests a direct connection to breast or breast implant, whereas the same ALCL can occur, although occasionally, in regions other than the breast and with im- plantable medical devices different from breast implants, all connected to each other by the rough surface of devices. We therefore believe that a more specific term such as Rough Implant Associated-Anaplastic Large Cell Lymphoma (RIA- ALCL) is needed to better define this pathology

Long-Term Clinical and Aesthetic Results of a Systematic Fat Transfer Protocol for Total Breast Reconstruction after Nipple-Sparing Mastectomy

Background: Autologous fat transfer can be safely offered for total breast reconstruction after nipple-sparing mastectomy. The aim of this study was to extend a fat transfer protocol to smokers and compare the long-term results among them and irradiated and nonirradiated patients. Methods: One hundred seventeen breasts after nipple-sparing mastectomy were prospectively enrolled and stratified in group A (25 irradiated), group B (21 smokers), or group C (71 controls). A standardized fat transfer protocol was used. Data collected were patient demographics, surgery information, and aesthetic analysis. Continuous and categorical variables were analyzed with the Kruskal-Wallis test, and the Cohen Kappa test was used to test interrater variability for the aesthetic analysis. Results: Groups were homogeneous for demographics (p > 0.05) but significantly different in number of fat transfer sessions (p < 0.001), mean volume of the first two treatments (p = 0.003), and mean total volume of injected fat (p = 0.002). Volume, shape, position of the breast mound, inframammary fold, and scar location subscales obtained high score evaluations without a significant difference among groups (p > 0.05), whereas skin texture subscale showed a lower score evaluation in group A (p = 0.003). Although a significant difference for total subscales was worse in group A (p = 0.004), the global score had a high rate evaluation in all groups (p = 0.145). Interrater reliability showed substantial agreement among all categories. Conclusion: Although further investigation is required, the authors confirm the efficacy of their fat transfer protocol for both irradiated and nonirradiated nipple-sparing mastectomy patients and propose its indication to smokers with comparable clinical and aesthetic results

Immediate prepectoral breast reconstruction using an ADM with smooth round implants. A prospective observational cohort study

Prepectoral breast reconstruction using acellular dermal matrices (ADMs) is well established and used in candidates for nipple/skin-sparing mastectomies; it is based on many different matrices and a great variability in breast implant selection. We describe our experience and clinical outcomes using Braxon & REG; ADMs and smooth round breast implants. Females aged 18-80 years who underwent mastectomies with immediate prepectoral reconstruction between April 2019 and April 2021 were prospectively included. Complications were classified as mastectomy-related (hematoma, necrosis) or reconstruction-related (seroma, infection, red breast syndrome). Binary logistic regression analysis was performed to assess correlation between complication rate and selected variables, which were analyzed per breast with Kruskal-Wallis H test. Fifty-eight patients (102 breasts) received 45 bilateral and 12 unilateral procedures. Drains collected 485.9 cc [range: 100-1260] and were removed 15.7 days [range: 6-29] postoperatively. We report 41 complications (40.2%): 33 mastectomy-related, 8 reconstruction-related. Reoperation occurred in 14 patients: 7 wound debridement and revisions under local anesthesia; and 7 explantation. Implant loss rate was 6.8%. Mastectomy and reconstruction complications were not correlated with any variable. In conclusion, we found prepectoral reconstruction with Braxon & REG; ADMs and smooth round implants to be associated with acceptable complication rates that are not influenced by any patient- or surgery-related factors. Drainage volume is comparable to other breast implant reconstructive techniques, but drains are left in place for longer.& COPY; 2023 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved