Adipose Tissue Therapeutics for Scar Rehabilitation after Thermal Injury

Background: Burn injuries are common and in the long term can lead to hypertrophic or keloid scars, pain and pruritus, limited mobility across joints, and disfigurement. Numerous reports suggest adipose derived tissues, including adipose derived stem cells (ADSCs) and processed lipoaspirate, can improve acutely healing wounds from a variety of etiologies including excisional, thermal, and radiation injuries by both secretion of growth factors and direct differentiation. There are many options for scar treatment, including laser therapy, silicone sheets, steroid injection, and even skin grafting however these techniques either lack optimal efficacy or involve significant cost and morbidity. Clinical case series suggest a beneficial effect of adipose tissues in improving scarred tissues, however this phenomenon has not been extensively studied in animal models especially in a thermal scar model. Objectives: (1) Determine if adipose tissue can accelerate and improve scar remodeling subacutely after acute wound healing has occurred. (2) Determine if the effect is related to adipose derived stem cells or other components of lipoaspirate. Methods: 50 CD1 nu/nu athymic mice received a standardized 70°C 10 second burn with a brass rod to the dorsal skin. Digital photographs and hyperspectral images were taken immediately following injury and serially over the study’s entirety. Burned skin reliably progressed through normal stages of wound healing to a scarred and granulating state. At six weeks post-burn animals received subcutaneous injection immediately beneath the scar with fresh human lipoaspirate (n=10), high dose hADSCs in matrigel (n=10), low dose hADSCs in matrigel (n=10), matrigel control (n=10), or were not injected (n=10). At 4 weeks post-injection (10 weeks post-burn) animals were sacrificed and tissue samples were harvested for histological molecular analysis. Results: Oxygenation and perfusion profiles from hyperspectral imaging and scar wound area correlated between groups suggesting methodological consistency of burns prior to any intervention. Oxygenated hemoglobin at 10 weeks in scars treated with lipoaspirate increased significantly more compared to 6-week pre-treatment baseline than all other groups (1.57x vs. 0.85x, p Conclusion: A consistent model of burn injury and scar maturation is described. Preliminary HSI and scar area data suggest scar improvement in lipoaspirate treated scars compared to ADSCs and controls

Lipoaspirate and Adipose Stem Cells as Potential Therapeutics for Chronic Scars

Introduction: Burn injuries can lead to hypertrophic or keloid scars, causing pain and long lasting mobility issues. Current therapies are often unsatisfactory, costly, or morbid. Prior studies suggest adipose derived stem cells (ADSCs) and lipoaspirate can improve scar outcomes of acute thermal wounds. Clinical reports suggest lipoaspirate and ADSCs can improve chronic burn scar remodeling. However, this has not been extensively studied in animal models. We sought to determine if adipose tissue can improve chronic scar remodeling and to compare the effects of ADSCs and processed lipoaspirate. Methods: 50 CD1 nu/nu athymic mice received a standardized deep partial-thickness thermal burn. Scars matured for 6 weeks. Photographs and perfusion measurements by hyperspectral imaging (HSI) were taken over the entire study. Lipoaspirate and ADSCs (SVF and ex-vivo culture with flow cytometry confirmation) were obtained from a discarded human pannus specimen. After 6 weeks, animals received a 0.6cc subcutaneous graft beneath the scar of either: human lipoaspirate processed with the Coleman technique, high-dose (106) hADSCs in Matrigel, low-dose (104) hADSCs in Matrigel, Matrigel only, or not injected (n=10 per group). At 10 weeks, animals were sacrificed and scar tissue was harvested for histological and molecular analysis. Results: HSI oxygenated hemoglobin values in lipoaspirate treated scars increased significantly more compared to 6-week pre-treatment baseline than all other groups (p \u3c 0.05). Planimetry analysis showed reduction in wound area in lipoaspirate treated mice compared to control groups (p \u3c 0.01). Blood vessel density quantification on Masson’s trichrome stains suggests increased density in lipoaspirate treated scars versus controls (p \u3c 0.01). Conclusion: HSI, blood vessel density, and scar analysis suggest improvement in lipoaspirate treated scars compared to controls. Preliminary molecular data offers some insight to this trend. No effect was seen with ADSCs at either concentration at the analyzed timepoints. Molecular analyses are ongoing to investigate cellular mechanisms in regulating scar remodeling

Gastric Outlet Obstruction at Bugando Medical Centre in Northwestern Tanzania: A Prospective Review of 184 Cases.

Gastric outlet obstruction poses diagnostic and therapeutic challenges to general surgeons practicing in resource-limited countries. There is a paucity of published data on this subject in our setting. This study was undertaken to highlight the etiological spectrum and treatment outcome of gastric outlet obstruction in our setting and to identify prognostic factors for morbidity and mortality. This was a descriptive prospective study which was conducted at Bugando Medical Centre between March 2009 and February 2013. All patients with a clinical diagnosis of gastric outlet obstruction were, after informed consent for the study, consecutively enrolled into the study. Statistical data analysis was done using SPSS computer software version 17.0. A total of 184 patients were studied. More than two-third of patients were males. Patients with malignant gastric outlet obstruction were older than those of benign type. This difference was statistically significant (p < 0.001). Gastric cancer was the commonest malignant cause of gastric outlet obstruction where as peptic ulcer disease was the commonest benign cause. In children, the commonest cause of gastric outlet obstruction was congenital pyloric stenosis (13.0%). Non-bilious vomiting (100%) and weight loss (93.5%) were the most frequent symptoms. Eighteen (9.8%) patients were HIV positive with the median CD 4+ count of 282 cells/μl. A total of 168 (91.3%) patients underwent surgery. Of these, gastro-jejunostomy (61.9%) was the most common surgical procedure performed. The complication rate was 32.1 % mainly surgical site infections (38.2%). The median hospital stay and mortality rate were 14 days and 18.5% respectively. The presence of postoperative complication was the main predictor of hospital stay (p = 0.002), whereas the age > 60 years, co-existing medical illness, malignant cause, HIV positivity, low CD 4 count (<200 cells/μl), high ASA class and presence of surgical site infection significantly predicted mortality ( p< 0.001). The follow up of patients was generally poor as more than 60% of patients were lost to follow up. Gastric outlet obstruction in our setting is more prevalent in males and the cause is mostly malignant. The majority of patients present late with poor general condition. Early recognition of the diagnosis, aggressive resuscitation and early institution of surgical management is of paramount importance if morbidity and mortality associated with gastric outlet obstruction are to be avoided

Challenges and Solutions for Vehicular Ad-Hoc Networks Based on Lightweight Blockchains

Current research with Vehicular Ad-hoc Networks (VANETs) has focused on adapting an efficient consensus mechanism and reducing the blockchain size while maintaining security. Care must be taken when implementing blockchains within VANET applications to leverage the chains’ strengths while mitigating their weaknesses. These chains can serve as distributed ledgers that provide storage for more than financial transactions. The security provided by longer blockchains constitutes a nearly immutable, decentralized data structure that can store any data relevant to the applications. However, these chains must be adapted to the ad-hoc, resource-constrained environments found in VANETs. In the absence of abundant resources and reliable network connections, chain operation and maintenance must address the challenges presented by highly mobile nodes in novel ways, including situations such as emergency messaging that require real-time responses. Researchers have included different mechanisms to realize lightweight blockchains, such as adding reputation to existing consensus mechanisms, condensing the consensus committees, using geographical information, and monitoring a nodes behavior in attempts to adapt blockchains to these domains. This paper analyzes the challenges and gives solutions for these different mechanisms to realize lightweight blockchains for VANETs

Design of a Novel Terahertz Metamaterial Absorber for Sensing Applications

This paper presents and evaluates a new terahertz metamaterial absorber (MMA) for sensing applications. Because of its unique properties, metamaterial-based sensors are widely employed in a variety of applications. The reported structure comprises of two identical metallic patches, a dielectric spacer and a ground metal plane. The finite element approach has been utilized to simulate and analyse the design. It is found that the MMA offered a prominent resonant peak with near 100% absorbance at frequency 4.5 THz due to the resultant effect of coupling between the two identical patches. In addition, surface current distribution, absorption mechanism and structural parametric analysis has also been investigated. The peak is designated as \u27A\u27, with a line width of 0.02 THz and a quality factor (Q-factor) of 225, which is sensitive to the refractive index of the environment (RI). As a result of its highly sensitive sensing capabilities, the proposed design can be employed as a sensor for refractive index, having 1.6 THz per refractive index unit (RIU) sensitivity and figure of merit (FoM) of 80 in terms of change in RI of the environment. The majority of biomedical samples have RI of 1.3 to 1.36, which is worth highlighting. Thus, biomedical applications may be possible with the suggested sensor

Double gastric dieulafoy′s lesion treated with endoscopic band ligation

Dieulafoy’s lesion is an uncommon cause of non-variceal upper gastrointestinal (GI) bleed. They are commonly seen in stomach and are usually single. Rarely, multiple DLs may cause clinically significant GI bleed. We report a rare case of upper GI bleed due to two DL along the lesser curvature of the stomach. Hemostasis was achieved by endoscopic band ligation. Patient did not have further recurrences and was asymptomatic after 2 years

Sentiment Analysis of COVID-19 Tweets Using Deep Learning and Lexicon-Based Approaches

Social media is a platform where people communicate, share content, and build relationships. Due to the current pandemic, many people are turning to social networks such as Facebook, WhatsApp, Twitter, etc., to express their feelings. In this paper, we analyse the sentiments of Indian citizens about the COVID-19 pandemic and vaccination drive using text messages posted on the Twitter platform. The sentiments were classified using deep learning and lexicon-based techniques. A lexicon-based approach was used to classify the polarity of the tweets using the tools VADER and NRCLex. A recurrent neural network was trained using Bi-LSTM and GRU techniques, achieving 92.70% and 91.24% accuracy on the COVID-19 dataset. Accuracy values of 92.48% and 93.03% were obtained for the vaccination tweets classification with Bi-LSTM and GRU, respectively. The developed models can assist healthcare workers and policymakers to make the right decisions in the upcoming pandemic outbreaks