Mycobacterium tuberculosis infection drives differential responses in the bone marrow hematopoietic stem and progenitor cells.

Hematopoietic stem and progenitor cells (HSPCs) play a vital role in the host response to infection through the rapid and robust production of mature immune cells. These HSPC responses can be influenced, directly and indirectly, by pathogens as well. Infection with Mycobacterium tuberculosis (Mtb) can drive lymphopoiesis through modulation of type I interferon (IFN) signaling. We have previously found that the presence of a drug resistance (DR)-conferring mutation in Mtb drives altered host-pathogen interactions and heightened type I IFN production in vitro. But the impacts of this DR mutation on in vivo host responses to Mtb infection, particularly the hematopoietic compartment, remain unexplored. Using a mouse model, we show that, while drug-sensitive Mtb infection induces expansion of HSPC subsets and a skew toward lymphopoiesis, DR Mtb infection fails to induce an expansion of these subsets and an accumulation of mature granulocytes in the bone marrow. Using single-cell RNA sequencing, we show that the HSCs from DR Mtb-infected mice fail to upregulate pathways related to cytokine signaling across all profiled HSC subsets. Collectively, our studies report a novel finding of a chronic infection that fails to induce a potent hematopoietic response that can be further investigated to understand pathogen-host interaction at the level of hematopoiesis.

Heat and mass transfer analysis for magnetized flow of [Formula: see text] nanolubricant with variable properties: an application of Cattaneo-Christov model.

The current study scrutinizes heat and mass transfer features of magnetized flow of [Formula: see text] nanolubricant over Riga plate in a Darcy Forchheimer medium. The effects of variable viscosity, thermal radiation, variable thermal conductivity, viscous dissipation and uniform heat source/sink are examined in this study. The diffusion model presented by Cattaneo-Christov is incorporated in this study to enclose heat and mass transport phenomenon. Additionally, the mass transfer rate is inspected subjected to the effects of variable solutal diffusivity and higher order chemical reaction. Heat and mass transfer phenomena have significant applications in the disciplines of science and technology that can be seen everywhere in nature. This simultaneous transportation phenomenon indicates a variety of applications in manufacturing processes, aerodynamics, cooling systems, environmental sciences, oceanography, food industries, biological disciplines, and energy transport systems etc. The modeled system of PDEs is metamorphosed to nonlinear ODEs with the introduction of appropriate transformations. An eminent bvp4c method in MATLAB has been incorporated to execute the resulting system of ODEs numerically. The outcomes of velocity, temperature and concentration profiles corresponding to various emerging parameters have been exposed graphically. The motion of [Formula: see text] nanolubricant tends to enhance significantly with larger modified Hartmann number, whereas converse behavior is reported by increasing porosity parameter and variable viscosity parameter. The greater heat transfer rate is observed for variable thermal conductivity parameter. The rates of heat and mass transfer slow down for thermal and solutal time relaxation parameters respectively. The concentration profile gets enriched by growing the order of the chemical reaction and variable mass diffusivity parameter. It is concluded that by increasing solid volume fraction up to [Formula: see text], the viscosity of the nanolubricant enhances up to [Formula: see text] which consequently slows down motion of the nanolubricant but increases temperature and concentration profiles.

Numerically analysis of Marangoni convective flow of hybrid nanofluid over an infinite disk with thermophoresis particle deposition.

This study discusses the flow of hybrid nanofluid over an infinite disk in a Darcy-Forchheimer permeable medium with variable thermal conductivity and viscosity. The objective of the current theoretical investigation is to identify the thermal energy characteristics of the nanomaterial flow resulting from thermo-solutal Marangoni convection on a disc surface. By including the impacts of activation energy, heat source, thermophoretic particle deposition and microorganisms the proposed mathematical model becomes more novel. The Cattaneo-Christov mass and heat flux law is taken into account when examining the features of mass and heat transmission rather than the traditional Fourier and Fick heat and mass flux law. MoS2 and Ag nanoparticles are dispersed in the base fluid water to synthesize the hybrid nanofluid. PDEs are transformed to ODEs by using similarity transformations. The RKF-45th order shooting method is used to solve the equations. With the use of appropriate graphs, the effects of a number of non-dimensional parameters on velocity, concentration, microorganism, and temperature fields are addressed. The local Nusselt number, density of motile microorganisms and Sherwood number are calculated numerically and graphically to derive correlations in terms of the relevant key parameters. The findings show that as we increase the Marangoni convection parameter, skin friction, local density of motile microorganisms, Sherwood number, velocity, temperature and microorganisms profiles increase, whereas Nusselt number and concentration profile exhibit an opposite behavior. The fluid velocity is reduced as a result of enhancing the Forchheimer parameter and Darcy parameter.

Neonatal imprinting of alveolar macrophages via neutrophil-derived 12-HETE.

Resident-tissue macrophages (RTMs) arise from embryonic precursors1,2, yet the developmental signals that shape their longevity remain largely unknown. Here we demonstrate in mice genetically deficient in 12-lipoxygenase and 15-lipoxygenase (Alox15-/- mice) that neonatal neutrophil-derived 12-HETE is required for self-renewal and maintenance of alveolar macrophages (AMs) during lung development. Although the seeding and differentiation of AM progenitors remained intact, the absence of 12-HETE led to a significant reduction in AMs in adult lungs and enhanced senescence owing to increased prostaglandin E2 production. A compromised AM compartment resulted in increased susceptibility to acute lung injury induced by lipopolysaccharide and to pulmonary infections with influenza A virus or SARS-CoV-2. Our results highlight the complexity of prenatal RTM programming and reveal their dependency on in trans eicosanoid production by neutrophils for lifelong self-renewal.

Novel approaches to preventing phagosomal infections: timing is key.

Prophylactic vaccination strategies designed to prevent diseases caused by pathogens using the phagolysosome of innate immune cells as a site of intracellular replication and survival have been largely ineffective. These include Mycobacterium tuberculosis (Mtb), Leishmania spp., and Cryptococcus spp. These failed strategies have traditionally targeted CD4+ T helper (Th) 1 cell-mediated immune memory, deeming it crucial for vaccine efficacy. This failure warrants an investigation of alternative mediators of protection. Here, we suggest three novel approaches to activate phagocytic cells prior to or at the time of infection. We hypothesize that preventing the formation of the pathogen niche within the phagolysosome is essential for preventing disease, and a greater emphasis on the timing of phagocyte activation should generate more effective prophylactic treatment options.

A single centre experience of local perforator flaps in oncoplastic breast surgery; a cross-sectional study.

Background & objectives: Various oncoplastic techniques have emerged over the years to preserve breast cosmesis and symmetry without compromising the principles of tumor excision. One of the newer techniques for breast volume replacement to achieve symmetry and cosmesis is the use of fasciocutaneous pedicled chest wall perforator flaps or local perforator flaps (LPF). The objectives of this study were to document the details of the surgical procedure as well as patient-reported satisfaction and well-being following the procedure using a validated BREAST-Q tool among Pakistani women. Materials & methods: This cross-sectional study was conducted from March 2019 to February 2021 enrolling 25 female patients who underwent breast conservative surgery using LPF for breast tumors at The Aga Khan University Hospital, Karachi. Data related to the procedure was collected on a pre-designed proforma. Cosmetic outcomes and patient satisfaction were evaluated using 2 scales from BREAST-Q BCT domain version 2.0. The questionnaire was self-administered by the patients during their routine follow-up in the clinic. Data was analyzed using the Statistical Package for Social Sciences (SPSS) version 23. Mean (SD)/median (IQR) were computed for quantitative variables and frequency and percentages were calculated for qualitative variables. 2 sample t-test was applied. P-value ≤0.05 was considered significant. Results: 25 patients underwent LPF with a mean age of 47 ± 13.1 years. 8 LICAP, 7 AICAP, and 10 LTAP flaps were performed. Two postoperative complications of wound site erythema were encountered. 23 women were eligible for the BREAST-Q survey. Median (IQR) postoperative satisfaction with breasts and physical well-being chest (equivalent Rasch transformed score) was 100 (41) and 76 [18] respectively. We found high satisfaction with breasts and comparable physical well-being among Pakistani women after LPF surgeries. Conclusion: Local perforator flaps in oncoplastic breast-conserving surgery are a good option showing high satisfaction with breasts and physical well-being in Pakistani women.

Corrigendum: Curdlan Limits Mycobacterium tuberculosis Survival Through STAT-1 Regulated Nitric Oxide Production.

[This corrects the article DOI: 10.3389/fmicb.2019.01173.].

Brain motor and fear circuits regulate leukocytes during acute stress.

The nervous and immune systems are intricately linked1. Although psychological stress is known to modulate immune function, mechanistic pathways linking stress networks in the brain to peripheral leukocytes remain poorly understood2. Here we show that distinct brain regions shape leukocyte distribution and function throughout the body during acute stress in mice. Using optogenetics and chemogenetics, we demonstrate that motor circuits induce rapid neutrophil mobilization from the bone marrow to peripheral tissues through skeletal-muscle-derived neutrophil-attracting chemokines. Conversely, the paraventricular hypothalamus controls monocyte and lymphocyte egress from secondary lymphoid organs and blood to the bone marrow through direct, cell-intrinsic glucocorticoid signalling. These stress-induced, counter-directional, population-wide leukocyte shifts are associated with altered disease susceptibility. On the one hand, acute stress changes innate immunity by reprogramming neutrophils and directing their recruitment to sites of injury. On the other hand, corticotropin-releasing hormone neuron-mediated leukocyte shifts protect against the acquisition of autoimmunity, but impair immunity to SARS-CoV-2 and influenza infection. Collectively, these data show that distinct brain regions differentially and rapidly tailor the leukocyte landscape during psychological stress, therefore calibrating the ability of the immune system to respond to physical threats.

Male Breast Cancer: The Three Decades' Experience of a Tertiary Care Hospital in a Lower-Middle Income Country.

Introduction Male breast cancer is uncommon and managed on the guidelines of female breast cancer due to tumor rarity. We sought to identify the incidence, clinicopathological features, and survival of all male breast cancer patients managed in our hospital. Methods A retrospective cross-sectional study was conducted at Aga Khan University Hospital (AKUH), Karachi, Pakistan, from January 1986 to December 2018. Demographic data, treatment records, and follow-up data of all male breast cancer patients who were treated at AKUH was reviewed. Results Thirty-eight out of 42 patients who presented over a period of 32 years were included. The mean age was 63 years. The most common tumor type and subtype were invasive ductal carcinoma (89.5%) and luminal A (73.7%), respectively. The majority (36.8%) of the patients presented at stage III. Among 30 (78.9%) patients who underwent surgery, mastectomy was performed in 30 (78.9%), upfront axillary clearance in 24 (63.2%), axillary sampling in five (15.1%) cases, and sentinel lymph node biopsy in one (2.6%) case. Neoadjuvant chemotherapy was given to 10 (26.3%) patients, and adjuvant chemotherapy to eight (21.1%) patients. Adjuvant hormonal treatment was administered to 22 (57.9%) patients, and 13 (34%) patients received adjuvant radiation to the chest wall. The five-year overall survival was 38.2% and the median survival was 36 months. The five-year disease-free survival (DFS) was found to be 33.7%. Conclusion Breast cancer in males presents at an advanced stage with poor survival. Multicenter studies are required to accurately identify incidence, prognostic factors, and outcomes in order to have a better understanding of its management.

BCG vaccination provides protection against IAV but not SARS-CoV-2.

Since the vast majority of species solely rely on innate immunity for host defense, it stands to reason that a critical evolutionary trait like immunological memory evolved in this primitive branch of our immune system. There is ample evidence that vaccines such as bacillus Calmette-Guérin (BCG) induce protective innate immune memory responses (trained immunity) against heterologous pathogens. Here we show that while BCG vaccination significantly reduces morbidity and mortality against influenza A virus (IAV), it fails to provide protection against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). In contrast to IAV, SARS-CoV-2 infection leads to unique pulmonary vasculature damage facilitating viral dissemination to other organs, including the bone marrow (BM), a central site for BCG-mediated trained immunity. Finally, monocytes from BCG-vaccinated individuals mount an efficient cytokine response to IAV infection, while this response is minimal following SARS-CoV-2. Collectively, our data suggest that the protective capacity of BCG vaccination is contingent on viral pathogenesis and tissue tropism.

Analysing the trends in breast surgery practice during COVID-19 pandemic: A comparative study with the Pre-COVID era.

BACKGROUND: The emergence of coronavirus disease 2019 (COVID-19) pandemic has crippled the healthcare systems all over the world. Cancer treatment is indispensable and disruption in its provision can lead to unanticipated consequences. No local data exists that has quantified the impact of COVID-19 pandemic on breast cancer surgery in a lower middle-income country (LMIC), therefore, the present retrospective comparative cohort study is directed to determine the trends in breast surgery operative volumes and its outcomes at our institution in Pakistan. MATERIALS AND METHODS: Data was collected retrospectively from Pre-COVID-19 and COVID-19 era to determine impact of the current pandemic on breast cancer management practices and outcomes. RESULTS: Cohort results showed a decline in the number of surgeries during COVID-19 era. A total 149 cases were operated during study period vs. 231 during same Pre-COVID-19 i.e. a 35.5% drop in cancer surgeries. In early COVID-19 time frame, only 4 patients had breast reconstruction, 12 out of 149 (8.05%) surgical candidates were identified having positive COVID-19 status preoperatively and one ASA class 3 patient caught COVID-19 post-surgery and succumbed to virus. CONCLUSION: Pandemic has a negative effect on cancer management in a LMIC with compromised access and care of cancer patients.

Human alveolar macrophage metabolism is compromised during Mycobacterium tuberculosis infection.

Pulmonary macrophages have two distinct ontogenies: long-lived embryonically-seeded alveolar macrophages (AM) and bone marrow-derived macrophages (BMDM). Here, we show that after infection with a virulent strain of Mycobacterium tuberculosis (H37Rv), primary murine AM exhibit a unique transcriptomic signature characterized by metabolic reprogramming distinct from conventional BMDM. In contrast to BMDM, AM failed to shift from oxidative phosphorylation (OXPHOS) to glycolysis and consequently were unable to control infection with an avirulent strain (H37Ra). Importantly, healthy human AM infected with H37Ra equally demonstrated diminished energetics, recapitulating our observation in the murine model system. However, the results from seahorse showed that the shift towards glycolysis in both AM and BMDM was inhibited by H37Rv. We further demonstrated that pharmacological (e.g. metformin or the iron chelator desferrioxamine) reprogramming of AM towards glycolysis reduced necrosis and enhanced AM capacity to control H37Rv growth. Together, our results indicate that the unique bioenergetics of AM renders these cells a perfect target for Mtb survival and that metabolic reprogramming may be a viable host targeted therapy against TB.

Quantitative proteomics and biological activity of extracellular vesicles engineered to express SARS-CoV-2 spike protein.

SARS-CoV-2 viral infection led to the devastating COVID-19 pandemic, where illness stemmed from interactions between virions and recipient host cells resulting in multi-layered pathological consequences. The role of the infection portal is now understood to be the cellular angiotensin converting enzyme-2 (ACE2) receptor, which binds to viral spike (S) protein initiating virion internalisation process. Since SARS-CoV-2 virions bear some resemblance to endogenously produced small extracellular vesicles (sEVs) we reasoned that EVs engineered to express S protein (viral mimics) may interfere with viral infection. Here, we report generation of HEK293T cells producing sEVs enriched for transmembrane S-protein tagged with green fluorescent protein (S/GFP). Strikingly, S protein drove the GFP tag to the membrane of sEVs, while GFP alone was not efficiently included in the sEV cargo. High-throughput quantitative proteomics revealed that S/GFP sEVs contained over 1000 proteins including canonical components of the exosomal pathway such as ALIX, syntenin-1, and tetraspanins (CD81, CD9), but depleted for calnexin and cytochrome c. We found that 84 sEV proteins were significantly altered by the presence of S/GFP. S protein expressing EVs efficiently adhered to target cells in an ACE2-dependent manner, but they were poorly internalised. Importantly, prolonged administration of S/GFP EV to K18-hACE2 mice provided a significant protection against SARS-CoV-2 infection. Thus, the generation of sEV containing S protein can be considered as a novel therapeutic approach in reducing the transmission of SARS-CoV-2.

Immunotherapeutic Role of NOD-2 and TLR-4 Signaling as an Adjunct to Antituberculosis Chemotherapy.

Tuberculosis (TB) treatment is lengthy and inflicted with severe side-effects. Here, we attempted a novel strategy to reinforce host immunity through NOD-like receptor (NOD-2) and Toll-like receptor (TLR-4) signaling in the murine model of TB. Intriguingly, we noticed that it not only bolstered the immunity but also reduced the dose and duration of rifampicin and isoniazid therapy. Further, we observed expansion in the pool of effector (CD44hi, CD62Llo, CD127hi) and central (CD44hi, CD62Lhi, CD127hi) memory CD4 T cells and CD8 T cells and increased the intracellular killing of Mycobacterium tuberculosis (Mtb) by activated dendritic cells [CD86hi, CD40hi, IL-6hi, IL-12hi, TNF-αhi, nitric oxide (NO)hi] with significant reduction in Mtb load in the lungs and spleen of infected animals. We infer that the signaling through NOD-2 and TLR-4 may be an important approach to reduce the dose and duration of the drugs to treat TB.

Features of Cu and TiO2 in the flow of engine oil subject to thermal jump conditions.

The recent work investigates the heat transfer attributes in the flow of engine oil which comprises of nano-particles such as Cu and TiO2. The performance of Copper and Titanium oxide is over looked in the flow of engine oil. The energy equation is amended by the features of thermal radiation, viscous dissipation, and heat generation. The mathematical model signifies the porosity, entropy generation and moving flat horizontal surface with the non-uniform stretching velocity. Quasi-linearization, which is a persuasive numerical technique to solve the complex coupled differential equations, is used to acquire the numerical solution of the problem. Flow and heat transfer aspects of Cu-TiO2 in the flow are examined against the preeminent parameters. The flow is significantly affected by the thermal jump conditions and porous media. It is observed here that the temperature as well as heat transport rate is reduced with the effect of involved preeminent parameters. However, such fluids must be used with caution in applications where a control on the heat transfer is required. We may conclude that the recent study will provide assistance in thermal cooling systems such as engine and generator cooling, nuclear system cooling, aircraft refrigeration system, and so forth.

Oncoplastic surgery: A suitable alternative to conventional breast conserving surgery in low - Middle income countries; a retrospective cohort study.

INTRODUCTION: Breast Conserving Surgery (BCS) with whole breast radiation is now standard of care as a safer alternative to Mastectomy in terms of loco-regional recurrence and long-term survival. Despite this, a frequent pitfall of conventional BCS is positive surgical margins and need for second surgery with a reported frequency of 12-59 % in literature. Oncoplastic Surgery can be a safer, more cost effective alternate to conventional BCS owing to its higher rate of negative surgical margins (4-6% vs 12-59 %) and better cosmetic results. We aim to prove utility of Oncoplastic surgery for Low-Middle income countries. OBJECTIVE: The aim of this study was to determine Oncoplastic Surgery as a more appropriate alternative to Conventional Breast Conserving Surgery for Low-Middle Income countries in terms of its lower positive margins and re-excision rates. METHODOLOGY: A retrospective comparative single center study by reviewing patient's medical records from August 2016 to June 2020 was conducted. Rate of positive margins and re-excisions along with mean volume of resection specimen, mean tumor size and quadrant dealt by both surgical procedures were compared. RESULTS: Out of 421 patients 249 patients underwent oncoplastic surgery and were compared with 173 patients who had conventional breast conserving surgery. Positive margins were seen in 5 patients (2 %) in OPS group whereas in 31 (17.9 %) patients in BCS group (p value < 0.001). Therefore, 2 from OPS group and 17 from BCS group underwent re-excision (p value < 0.002).None in OPS group while 7 out of 17 patients in BCS group underwent mastectomy as second procedure. Mean tumor size in OPS group was 2.26 cm ± SD 1.66 and in BCS group was 1.94 cm ± SD 1.28. Majority of Lobular carcinoma and Ductal carcinoma in-situ, multifocal, upper inner and central quadrant tumors and those unresponsive to neo-adjuvant therapy were treated by Oncoplastic techniques. CONCLUSION: Oncoplastic surgery has shown promising results as a safer tool to deal with large, complex tumors, lesions in difficult anatomical locations, multifocal or progressing on neo-adjuvant therapy. With its low Re-excision rates, it is a better alternative to traditional Breast Conserving approach for overburdened and resource limited health care system of Low-Middle Income countries. Multi-center, prospective trials are needed to determine its feasibility.

n-Gram based language processing using Twitter dataset to identify COVID-19 patients.

Due to the rapid growth of electronic documents, e.g., tweets, blogs, Facebook posts, snaps in different languages that use the same writing script, language categorization, and processing have great importance. For instance, to identify COVID-19 positive patients or people's emotions on COVID-19 pandemic from tweets written in 35 different languages faster and accurate, language categorization and processing of tweets is significantly essential. Among many language categorization and processing techniques, character and word n-gram based techniques are very popular and simple but very efficient for categorizing and processing both short and large documents. One of the fundamental problems of language processing is the efficient use of memory space in implementing a technique so that a vast collection of documents can be easily categorized and processed. In this paper, we introduce a framework that categorizes the language of tweets using n-gram based language categorization technique and further processes the tweets using the machine-learning approach, Linear Support Vector Machine (LSVM), that may be able to identify COVID-19 positive patients. We evaluate and compare the performance of the proposed framework in terms of language categorization accuracy, precession, recall, and F-measure over n-gram length. The proposed framework is scalable as many other applications that involve extracting features and classifying languages collected from social media, and different types of networks may use this framework. This proposed framework, also being a part of health monitoring and improvement, tends to achieve the goal of having a sustainable society.

Utility of post mastectomy radiotherapy among patients with T1/ T2 N1 disease: A retrospective cohort study.

BACKGROUND: Pakistan has the highest incidence of breast cancer among Asian Countries but there is insufficient representation of local data addressing breast cancer treatment and outcome. We sought to determine the role of post-mastectomy radiotherapy (PMRT) in T1- T2 breast cancer with 1-3 positive axillary lymph nodes. METHODS: Data was reviewed retrospectively of total 755 patients out of which 291 received PMRT and 464 did not from two large breast cancer centres. RESULTS: With a median follow up of 78 months, 4 (4.5%) patients developed loco regional recurrence (LRR) in the PMRT group while a substantial number 74 (24.4%) recurred in the non PMRT group (p = 0.000). Loco regional free survival rate (LRFS) and overall survival rate (OS) was significantly better for PMRT patients than non-PMRT patients (P = <0.000). Multivariate analysis identified young age, lymphovascular invasion, extra capsular extension, triple negative and ER/PR negative were independent prognostic factors affecting loco regional free survival (LRFS). CONCLUSION: Disease recurrence is a substantial issue in 1-3 node group despite early stage, PMRT has an instrumental effect in improving LRFS and OS.