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Programmed cell death (self-induced) is intrinsic to all cellular life forms, including unicellular organisms. However, cell death research has focused on animal models to understand cancer, degenerative disorders, and developmental processes. Recently delineated suicidal death mechanisms in bacteria and fungi have revealed ancient origins of animal cell death that are intertwined with immune mechanisms, allaying earlier doubts that self-inflicted cell death pathways exist in microorganisms. Approximately 20 mammalian death pathways have been partially characterized over the last 35 years. By contrast, more than 100 death mechanisms have been identified in bacteria and a few fungi in recent years. However, cell death is nearly unstudied in most human pathogenic microbes that cause major public health burdens. Here, we consider how the current understanding of programmed cell death arose through animal studies and how recently uncovered microbial cell death mechanisms in fungi and bacteria resemble and differ from mechanisms of mammalian cell death.
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Apoptosis , Hongos , Animales , Humanos , Apoptosis/genética , Hongos/genética , Hongos/metabolismo , Bacterias , MamíferosRESUMEN
A pet cockatoo was the suspected source of Cryptococcus neoformans recovered from an immunocompromised patient with cryptococcosis based on molecular analyses available in 2000. Here, we report whole genome sequence analysis of the clinical and cockatoo strains. Both are closely related MATα strains belonging to the VNII lineage, confirming that the human infection likely originated from pet bird exposure. The two strains differ by 61 single nucleotide polymorphisms, including eight nonsynonymous changes involving seven genes. To ascertain whether changes in these genes are selected for during mammalian infection, we passaged the cockatoo strain in mice. Remarkably, isolates obtained from mouse tissue possess a frameshift mutation in one of the seven genes altered in the human sample (LQVO5_000317), a gene predicted to encode an SWI-SNF chromatin-remodeling complex protein. In addition, both cockatoo and patient strains as well as mouse-passaged isolates obtained from brain tissue had a premature stop codon in a homologue of ZFC3 (LQVO5_004463), a predicted single-zinc finger containing protein, which is associated with larger capsules when deleted and reverted to a full-length protein in the mouse-passaged isolates obtained from lung tissue. The patient strain and mouse-passaged isolates show variability in virulence factors, with differences in capsule size, melanization, rates of nonlytic expulsion from macrophages, and amoeba predation resistance. Our results establish that environmental strains undergo genomic and phenotypic changes during mammalian passage, suggesting that animal virulence can be a mechanism for genetic change and that the genomes of clinical isolates may provide a readout of mutations acquired during infection.
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Criptococosis , Cryptococcus neoformans , Humanos , Animales , Ratones , Cryptococcus neoformans/genética , Virulencia/genética , Factores de Virulencia/genética , Evolución Biológica , MamíferosRESUMEN
Mammary gland homeostasis is maintained by adult tissue stem-progenitor cells residing within the luminal and basal epithelia. Dysregulation of mammary stem cells is a key mechanism for cancer development. However, stem cell characterization is challenging because reporter models using cell-specific promoters do not fully recapitulate the mammary stem cell populations. We previously found that a 270-basepair Runx1 enhancer element, named eR1, marked stem cells in the blood and stomach. Here, we identified eR1 activity in a rare subpopulation of the ERα-negative luminal epithelium in mouse mammary glands. Lineage-tracing using an eR1-CreERT2 mouse model revealed that eR1+ luminal cells generated the entire luminal lineage and milk-secreting alveoli-eR1 therefore specifically marks lineage-restricted luminal stem cells. eR1-targeted-conditional knockout of Runx1 led to the expansion of luminal epithelial cells, accompanied by elevated ERα expression. Our findings demonstrate a definitive role for Runx1 in the regulation of the eR1-positive luminal stem cell proliferation during mammary homeostasis. Our findings identify a mechanistic link for Runx1 in stem cell proliferation and its dysregulation in breast cancer. Runx1 inactivation is therefore likely to be an early hit in the cell-of-origin of ERα+ luminal type breast cancer.
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Receptor alfa de Estrógeno , Glándulas Mamarias Animales , Animales , Linaje de la Célula , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Subunidad alfa 2 del Factor de Unión al Sitio Principal/metabolismo , Elementos de Facilitación Genéticos/genética , Células Epiteliales/metabolismo , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/metabolismo , Ratones , Células Madre/metabolismoRESUMEN
Current drug discovery involves finding leading drug candidates for further development. New scientific approaches include molecular docking, ADMET studies, and molecular dynamic simulation to determine targets and lead compounds. Hepatitis B is a disease of concern that is a life-threatening liver infection. The protein considered for the study was HBx. The hepatitis B X-interacting protein crystal structure was obtained from the PDB database (PDB ID-3MSH). Twenty ligands were chosen from the PubChem database for further in silico studies. The present study focused on in silico molecular docking studies using iGEMDOCK. The triethylene glycol monoethyl ether derivative showed an optimum binding affinity with the molecular target HBx, with a high negative affinity binding energy of -59.02 kcal/mol. Lipinski's rule of five, Veber, and Ghose were followed in subsequent ADMET studies. Molecular dynamic simulation was performed to confirm the docking studies and to analyze the stability of the structure. In these respects, the triethylene glycol monoethyl ether derivative may be a promising molecule to prepare future hepatitis B drug candidates. Substantial research effort to find a promising drug for hepatitis B is warranted in the future.
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Simulación del Acoplamiento MolecularRESUMEN
Cryptococcus neoformans is a facultative intracellular pathogen and its interaction with macrophages is a key event determining the outcome of infection. Urease is a major virulence factor in C. neoformans but its role during macrophage interaction has not been characterized. Consequently, we analyzed the effect of urease on fungal-macrophage interaction using wild-type, urease-deficient and urease-complemented strains of C. neoformans. The frequency of non-lytic exocytosis events was reduced in the absence of urease. Urease-positive C. neoformans manifested reduced and delayed intracellular replication with fewer macrophages displaying phagolysosomal membrane permeabilization. The production of urease was associated with increased phagolysosomal pH, which in turn reduced growth of urease-positive C. neoformans inside macrophages. Interestingly, the ure1 mutant strain grew slower in fungal growth medium which was buffered to neutral pH (pH 7.4). Mice inoculated with macrophages carrying urease-deficient C. neoformans had lower fungal burden in the brain than mice infected with macrophages carrying wild-type strain. In contrast, the absence of urease did not affect survival of yeast when interacting with amoebae. Because of the inability of the urease deletion mutant to grow on urea as a sole nitrogen source, we hypothesize urease plays a nutritional role involved in nitrogen acquisition in the environment. Taken together, our data demonstrate that urease affects fitness within the mammalian phagosome, promoting non-lytic exocytosis while delaying intracellular replication and thus reducing phagolysosomal membrane damage, events that could facilitate cryptococcal dissemination when transported inside macrophages. This system provides an example where an enzyme involved in nutrient acquisition modulates virulence during mammalian infection.
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Encéfalo/patología , Criptococosis/patología , Cryptococcus neoformans/enzimología , Macrófagos/patología , Fagosomas/patología , Ureasa/metabolismo , Virulencia , Animales , Encéfalo/enzimología , Encéfalo/microbiología , Células Cultivadas , Criptococosis/microbiología , Femenino , Concentración de Iones de Hidrógeno , Macrófagos/enzimología , Macrófagos/microbiología , Ratones , Ratones Endogámicos C57BL , Fagosomas/enzimología , Ureasa/genética , Factores de Virulencia/metabolismoRESUMEN
Epigenetic regulation of gene expression by histone-modifying corepressor complexes is central to normal animal development. The NAD(+)-dependent deacetylase and gene repressor SIRT1 removes histone H4K16 acetylation marks and facilitates heterochromatin formation. However, the mechanistic contribution of SIRT1 to epigenetic regulation at euchromatic loci and whether it acts in concert with other chromatin-modifying activities to control developmental gene expression programs remain unclear. We describe here a SIRT1 corepressor complex containing the histone H3K4 demethylase LSD1/KDM1A and several other LSD1-associated proteins. SIRT1 and LSD1 interact directly and play conserved and concerted roles in H4K16 deacetylation and H3K4 demethylation to repress genes regulated by the Notch signaling pathway. Mutations in Drosophila SIRT1 and LSD1 orthologs result in similar developmental phenotypes and genetically interact with the Notch pathway in Drosophila. These findings offer new insights into conserved mechanisms of epigenetic gene repression and regulation of development by SIRT1 in metazoans.
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Proteínas de Drosophila/fisiología , Drosophila melanogaster/genética , Oxidorreductasas N-Desmetilantes/fisiología , Receptores Notch/genética , Sirtuina 1/fisiología , Animales , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/crecimiento & desarrollo , Epigénesis Genética , Regulación del Desarrollo de la Expresión Génica , Histonas/metabolismo , Inmunoprecipitación , Mutación , Oxidorreductasas N-Desmetilantes/genética , Oxidorreductasas N-Desmetilantes/metabolismo , Fenotipo , Receptores Notch/metabolismo , Sirtuina 1/genética , Sirtuina 1/metabolismoRESUMEN
Angiogenesis is a highly regulated process for formation of new blood vessels from pre-existing ones. Angiogenesis is dysregulated in various pathologies, including age-related macular degeneration, arthritis, and cancer. Inhibiting pathological angiogenesis therefore represents a promising therapeutic strategy for treating these disorders, highlighting the need to study angiogenesis in more detail. To this end, identifying the genes essential for blood vessel formation and elucidating their function are crucial for a complete understanding of angiogenesis. Here, focusing on potential candidate genes for angiogenesis, we performed a morpholino-based genetic screen in zebrafish and identified Cavin-2, a membrane-bound phosphatidylserine-binding protein and critical organizer of caveolae (small microdomains in the plasma membrane), as a regulator of angiogenesis. Using endothelial cells, we show that Cavin-2 is required for in vitro angiogenesis and also for endothelial cell proliferation, migration, and invasion. We noted a high level of Cavin-2 expression in the neovascular tufts in the mouse model of oxygen-induced retinopathy, suggesting a role for Cavin-2 in pathogenic angiogenesis. Interestingly, we also found that Cavin-2 regulates the production of nitric oxide (NO) in endothelial cells by controlling the stability and activity of the endothelial nitric-oxide synthase (eNOS) and that Cavin-2 knockdown cells produce much less NO than WT cells. Also, mass spectrometry, flow cytometry, and electron microscopy analyses indicated that Cavin-2 is secreted in endothelial microparticles (EMPs) and is required for EMP biogenesis. Taken together, our results indicate that in addition to its function in caveolae biogenesis, Cavin-2 plays a critical role in endothelial cell maintenance and function by regulating eNOS activity.
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Proteínas de la Membrana/metabolismo , Óxido Nítrico Sintasa de Tipo III/metabolismo , Neovascularización Retiniana/metabolismo , Retinopatía de la Prematuridad/metabolismo , Proteínas de Pez Cebra/metabolismo , Pez Cebra/metabolismo , Animales , Modelos Animales de Enfermedad , Estabilidad de Enzimas , Proteínas de la Membrana/genética , Ratones , Óxido Nítrico/genética , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo III/genética , Neovascularización Retiniana/genética , Retinopatía de la Prematuridad/genética , Retinopatía de la Prematuridad/patología , Pez Cebra/genética , Proteínas de Pez Cebra/genéticaRESUMEN
The sperm/oocyte decision in the hermaphrodite germline of Caenorhabditis elegans provides a powerful model for the characterization of stem cell fate specification and differentiation. The germline sex determination program that governs gamete fate has been well studied, but direct mediators of cell-type-specific transcription are largely unknown. We report the identification of spe-44 as a critical regulator of sperm gene expression. Deletion of spe-44 causes sperm-specific defects in cytokinesis, cell cycle progression, and organelle assembly resulting in sterility. Expression of spe-44 correlates precisely with spermatogenesis and is regulated by the germline sex determination pathway. spe-44 is required for the appropriate expression of several hundred sperm-enriched genes. The SPE-44 protein is restricted to the sperm-producing germline, where it localizes to the autosomes (which contain sperm genes) but is excluded from the transcriptionally silent X chromosome (which does not). The orthologous gene in other Caenorhabditis species is similarly expressed in a sex-biased manner, and the protein likewise exhibits autosome-specific localization in developing sperm, strongly suggestive of an evolutionarily conserved role in sperm gene expression. Our analysis represents the first identification of a transcriptional regulator whose primary function is the control of gamete-type-specific transcription in this system.
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Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Regulación del Desarrollo de la Expresión Génica , Procesos de Determinación del Sexo , Transducción de Señal/genética , Espermatozoides , Animales , Caenorhabditis elegans/genética , Caenorhabditis elegans/crecimiento & desarrollo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Puntos de Control del Ciclo Celular , Diferenciación Celular , Linaje de la Célula , Cromatina , Citocinesis , Masculino , Espermatogénesis/genética , Espermatozoides/citología , Espermatozoides/crecimiento & desarrollo , Espermatozoides/metabolismo , Células Madre/citología , Células Madre/metabolismo , Transcripción GenéticaRESUMEN
BACKGROUND AND OBJECTIVE: Intra capsular fracture of the neck of femur (FNF) treated traditionally with a dynamic hip screw (DHS) or three cancellous screws (3CS) has a high incidence of complications with reoperation rates between 20 % and 45 %. We hypothesized that FNF unites by primary healing. Therefore, intra-operative compression and absolute stability post-operatively until healing are essential. We postulated that FNF requires 2 types of implants- those which provide absolute stability for young patients with good bone stock and another with sliding mechanism for elderly patients with osteoporosis. We developed three novel fixation systems at our research institute in India using a modified DHS. In patients with good bone stock, locking DHS, called LHS and GSK triangular system (GSKT) provided intra-operative compression and absolute stability during the post-operative period. In those with poor bone stock, the controlled sliding DHS (CSDHS)was used as a locking implant might penetrate the hip joint. MATERIALS AND METHOD: 42 patients of FNF <55 years of age were studied. Among 39 patients with good bone stock, LHS was used in five patients and GSKT system was used in 34 patients. CSDHS was used in three patients with poor bone stock or communition. The patients were followed up for a minimum of eight months up to a maximum of two years, with the average follow up duration of 14 months. RESULTS: 32 out of 34 fractures treated by GSKT system united. Five cases managed by LHS and three by CSDHS, all united. The union rate was 95.2 %. Of the two failed cases, one patient had nonunion (NU), the other had deep infection. Avascular necrosis of the head (AVN) was detected in three patients treated with GSKT system in the second year following surgery. Two of them had hip pain while one was asymptomatic. Eight cases of FNF Pauwels type III underwent a primary valgus osteotomy. All of them united without complications. CONCLUSION: In patients with good bone stock, LHS and GSKT system allowed intra-operative compression and absolute post-operative stability without sliding of head fragment as the triangle construct is biomechanically the strongest. When bones are osteoporotic, a CSDHS provided controlled sliding (1 to 5 mm only). This pilot study showed a promising success rate of 95.2 %. We propose that the GSKT system may be used to treat intertrochanteric and other metaphyseal fractures as well. Further biomechanical studies are underway to strenghten the evidence needed for the widespread use of these implants.
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Tornillos Óseos , Fracturas del Cuello Femoral , Fijación Interna de Fracturas , Curación de Fractura , Humanos , Fracturas del Cuello Femoral/cirugía , Proyectos Piloto , Fijación Interna de Fracturas/métodos , Fijación Interna de Fracturas/instrumentación , Femenino , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Adulto , Curación de Fractura/fisiología , India/epidemiologíaRESUMEN
Caspases are a family of cysteine proteases that act as molecular scissors to cleave substrates and regulate biological processes such as programmed cell death and inflammation. Extensive efforts have been made to identify caspase substrates and to determine factors that dictate substrate specificity. Thousands of putative substrates have been identified for caspases that regulate an immunologically silent type of cell death known as apoptosis, but less is known about substrates of the inflammatory caspases that regulate an immunostimulatory type of cell death called pyroptosis. Furthermore, much of our understanding of caspase substrate specificities is derived from work done with peptide substrates, which do not often translate to native protein substrates. Our knowledge of inflammatory caspase biology and substrates has recently expanded and here, we discuss the recent advances in our understanding of caspase substrate specificities, with a focus on inflammatory caspases. We highlight new substrates that have been discovered and discuss the factors that engender specificity. Recent evidence suggests that inflammatory caspases likely utilize two binding interfaces to recognize and process substrates, the active site and a conserved exosite.
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Caspasas , Inflamación , Especificidad por Sustrato , Caspasas/metabolismo , Caspasas/genética , Humanos , Inflamación/metabolismo , Animales , Dominio Catalítico , PiroptosisRESUMEN
Cryptococcus neoformans causes lethal meningitis and accounts for approximately 10%-15% of AIDS-associated deaths worldwide. There are major gaps in our understanding of how this fungus invades the mammalian brain. To investigate the dynamics of C. neoformans tissue invasion, we mapped fungal localization and host cell interactions in infected brain, lung, and upper airways using mouse models of systemic and airway infection. To enable this, we developed an in situ imaging pipeline capable of measuring large volumes of tissue while preserving anatomical and cellular information by combining thick tissue sections, tissue clarification, and confocal imaging. We confirm high fungal burden in mouse upper airway after nasal inoculation. Yeast in turbinates were frequently titan cells, with faster kinetics than reported in mouse lungs. Importantly, we observed one instance of fungal cells enmeshed in lamina propria of the upper airways, suggesting penetration of airway mucosa as a possible route of tissue invasion and dissemination to the bloodstream. We extend previous literature positing bloodstream dissemination of C. neoformans, by finding viable fungi in the bloodstream of mice a few days after intranasal infection. As early as 24 h post systemic infection, the majority of C. neoformans cells traversed the blood-brain barrier, and were engulfed or in close proximity to microglia. Our work presents a new method for investigating microbial invasion, establishes that C. neoformans can breach multiple tissue barriers within the first days of infection, and demonstrates microglia as the first cells responding to C. neoformans invasion of the brain.IMPORTANCECryptococcal meningitis causes 10%-15% of AIDS-associated deaths globally. Still, brain-specific immunity to cryptococci is a conundrum. By employing innovative imaging, this study reveals what occurs during the first days of infection in brain and in airways. We found that titan cells predominate in upper airways and that cryptococci breach the upper airway mucosa, which implies that, at least in mice, the upper airways are a site for fungal dissemination. This would signify that mucosal immunity of the upper airway needs to be better understood. Importantly, we also show that microglia, the brain-resident macrophages, are the first responders to infection, and microglia clusters are formed surrounding cryptococci. This study opens the field to detailed molecular investigations on airway immune response, how fungus traverses the blood-brain barrier, how microglia respond to infection, and ultimately how microglia monitor the blood-brain barrier to preserve brain function.
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Síndrome de Inmunodeficiencia Adquirida , Criptococosis , Cryptococcus neoformans , Meningitis , Ratones , Animales , Microglía , Criptococosis/microbiología , Encéfalo/microbiología , MamíferosRESUMEN
On January 13th and 14th 2022, the Center for Translational Cancer Research organized the virtual third Indian Cancer Genome Atlas (ICGA) Conference 2022 "Biobanking to Omics - Collecting the Global Experience." This conference was planned as the steppingstone to help ICGA understand the road ahead and the probable roadblocks in its preparatory phase as ICGA begins to streamline the tumor tissue biobanking and multi-omics efforts in the Indian subcontinent. The first day of the conference was dedicated to updates on the current status of ICGA, the future prospect, and the global understanding of multi-omics efforts. The key highlights included two keynote speeches by Dr Wui Jin Koh, Senior Vice President and Chief Medical Office, National Comprehensive Cancer Network, and by Dr Christina Curtis, Associate Professor, Stanford University School of Medicine. The first day ended with an intriguing panel discussion on "ICGA updates and Future Steps." The second day focused on biobanking practices across the globe and several aspects of biobank setup such as infrastructure, maintenance, quality control, patient consent, and lessons learned from established biobanking setups. The talk by Rosita Kammler, Head, Translational Research Coordination, International Breast Cancer Study Group, Switzerland, and Ruhul Amin, Director, Bangladesh Medical Research Council were the key highlights. The second day also ended with an engaging panel discussion on "Tumor tissue biobanking - national and international perspectives." Overall, the conference was well received and had good attendance from national and international students, researchers, and faculty from academia as well as industry.
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Bancos de Muestras Biológicas , Neoplasias , Humanos , Neoplasias/genética , Neoplasias/terapia , BangladeshRESUMEN
The fungus Cryptococcus neoformans causes lethal meningitis in humans with weakened immune systems and is estimated to account for 10-15% of AIDS-associated deaths worldwide. There are major gaps in our understanding of how this environmental fungus evades the immune system and invades the mammalian brain before the onset of overt symptoms. To investigate the dynamics of C. neoformans tissue invasion, we mapped early fungal localisation and host cell interactions at early times in infected brain, lung, and upper airways using mouse models of systemic and airway infection. To enable this, we developed an in situ imaging pipeline capable of measuring large volumes of tissue while preserving anatomical and cellular information by combining thick tissue sections, tissue clarification, and confocal imaging. Made possible by these techniques, we confirm high fungal burden in mouse upper airway turbinates after nasal inoculation. Surprisingly, most yeasts in turbinates were titan cells, indicating this microenvironment enables titan cell formation with faster kinetics than reported in mouse lungs. Importantly, we observed one instance of fungal cells enmeshed in lamina propria of upper airways, suggesting penetration of airway mucosa as a possible route of tissue invasion and dissemination to the bloodstream. We extend previous literature positing bloodstream dissemination of C. neoformans, via imaging C. neoformans within blood vessels of mouse lungs and finding viable fungi in the bloodstream of mice a few days after intranasal infection, suggesting that bloodstream access can occur via lung alveoli. In a model of systemic cryptococcosis, we show that as early as 24 h post infection, majority of C. neoformans cells traversed the blood-brain barrier, and are engulfed or in close proximity to microglia. Our work establishes that C. neoformans can breach multiple tissue barriers within the first days of infection. This work presents a new method for investigating cryptococcal invasion mechanisms and demonstrates microglia as the primary cells responding to C. neoformans invasion.
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Introduction: The essential goal of neoadjuvant chemotherapy (NACT) is to downstage the primary tumor making it amenable for breast conservation surgery (BCS). However, since the safety of this surgery is paramount, post-NACT breast conservation rates remain low. As per the recommendation of the 2018 Early Breast Cancer Trialists' Collaborative Group (EBCTCG) overview of long-term post-NACT follow-up, we have devised a protocol for imaging, localization, rad-path analysis, and documentation of radiotherapy techniques to ensure the safety of post-NACT breast conservation. Methods: This is a retrospective cohort of 180 breast cancer patients who received NACT and were operated on by a single surgical oncologist from 2015 to 2020. After selection based on published guidelines, patients were treated with neoadjuvant systemic (chemo or hormone) therapy. In cases where primary tumors responded and reduced to 1-2 cm in size mid-NACT, the residual tumors were localized by clips under ultrasound guidance and calcification was wire localized. All patients were treated using appropriate surgical and oncoplastic techniques where indicated. Negative margins were ensured by intra-operative rad-path analysis. Adjuvant chemotherapy and radiotherapy were given as per protocol. Results: In 81 cases that required mastectomy at presentation, we were able to achieve a 72.8% post-NACT BCS rate with the help of oncoplasty. Overall, 142 of 180 (80%) patients were treated with breast conserving surgery of which 80% (121 of 142) were oncoplasty. Margins were assessed on intra-operative frozen and re-excised in the same setting. No positive margins were reported in final histopath of 142 breast conservation procedures. Post-operative complication rates after breast conservation in the first year were at 17% (24 of 142 including two major complications). Patient reported outcomes were satisfactory with increased satisfaction for breast conservation compared with immediate breast reconstruction. Discussion: Employing oncoplastic breast surgery (OBS) techniques following stringent protocols for accurate localization of the residual tumor, intra-operative rad-path analysis, and adjuvant treatments, we show successful breast conservation in 72.8% of our mastectomy-qualified patients after downstaging by NACT. We also report satisfactory outcomes for post-NACT surgery, patient-reported satisfaction, and survival.
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Hydrogen sulfide (H(2)S), a colorless gas with the pungent odor of rotten eggs has been reported to produce pharmacological actions in ocular and non-ocular tissues. We have evidence that H(2)S, using sodium hydrosulfide (NaHS) and sodium sulfide (Na(2)S) as donors can increase cyclic AMP (cAMP) production in neural retina. In the present study, we investigated the mechanism of action of H(2)S on cyclic nucleotide production in rat retinal pigment epithelial cells (RPE-J). Cultured RPE-J cells were incubated for 30 min in culture medium containing the cyclic nucleotide phosphodiesterase (PDE) inhibitor, IBMX (2 mM). Cells were exposed to varying concentrations of NaHS, the H(2)S substrate (L-cysteine), cyclooxygenase (COX) inhibitors or the diterpene activator of adenylate cyclase, forskolin in the presence or absence of H(2)S biosynthetic enzymes or the ATP-sensitive potassium (K(ATP)) channel antagonist, glibenclamide. Following drug-treatment at different time intervals, cell homogenates were prepared for cAMP assay using a well established methodology. In RPE-J cells, NaHS (10 nM-1 µM) produced a time-dependent increase in cAMP concentrations over basal levels which reached a maximum at 20 min. At this time point, both NaHS (1 nM-100 µM) and L-cysteine (1 nM-10 µM) produced a concentration-dependent significant (p<0.05) increase in cAMP concentrations over basal level. The effects of NaHS on cAMP levels in RPE-J cells was enhanced significantly (p<0.01) in the presence of the COX inhibitors, indomethacin and flurbiprofen. In RPE-J cells, the effects caused by forskolin (10 µM) on cAMP production were potentiated by addition of low concentrations of NaHS. Both the inhibitor of cystathionine ß-synthase (CBS), aminooxyacetic acid (AOA, 1 mM) and the inhibitor of cystathionine γ-lyase (CSE), proparglyglycine (PAG, 1mM) significantly attenuated the increased effect of L-cysteine on cAMP production. The K(ATP) channel antagonist, glibenclamide (100 µM) caused inhibition of NaHS induced-increase of cAMP formation in RPE-J cells. We conclude that, H(2)S (using H(2)S donor and substrate) can increase cAMP production in RPE-J cells, and removal of the apparent inhibitory effect of prostaglandins unmasks an excitatory activity of H(2)S on cAMP. Effects elicited by the H(2)S substrate on cAMP formation are dependent on biosynthesis of H(2)S catalyzed by the biosynthetic enzymes, CBS and CSE. In addition to the adenylyl cylcase pathway, K(ATP) channels are involved in mediating the observed effects of the H(2)S on cAMP production.
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AMP Cíclico/biosíntesis , Sulfuro de Hidrógeno/farmacología , Epitelio Pigmentado de la Retina/efectos de los fármacos , Alquinos/farmacología , Ácido Aminooxiacético/farmacología , Animales , Células Cultivadas , Inhibidores de la Ciclooxigenasa/farmacología , Cistationina betasintasa/fisiología , Cistationina gamma-Liasa/fisiología , Cisteína/farmacología , Relación Dosis-Respuesta a Droga , Activación Enzimática , Glicina/análogos & derivados , Glicina/farmacología , Canales KATP/metabolismo , Prostaglandinas/metabolismo , Ratas , Epitelio Pigmentado de la Retina/metabolismo , Sulfuros/farmacologíaRESUMEN
Breast cancers are treated according to the ER/PR or HER2 expression and show better survival outcomes with targeted therapy. Triple-negative breast cancers (TNBCs) with a lack of expression of ER/PR and HER2 are treated with systemic therapy with unpredictable responses and outcomes. It is essential to investigate novel markers to identify targeted therapies for TNBC. One such marker is YAP1, a transcription co-activator protein that shows association with poor prognosis of breast cancer. YAP1 transcriptionally regulates the expression of genes that drive the oncogenic phenotypes. Here, we assess a potential YAP target gene signature to predict a progressive subset of breast tumors from METABRIC and TCGA datasets. YAP1 target genes were shortlisted based on expression correlation and concordance with YAP1 expression and significant association with survival outcomes of patients. Hierarchical clustering was performed for the shortlisted genes. The utility of the clustered genes was assessed by survival analysis to identify a recurring subset. Expression of the shortlisted target genes showed significant association with survival outcomes of HER2-positive and TNBC subset in both datasets. The shortlisted genes were verified using an independent dataset. Further validation using IHC can prove the utility of this potential prognostic signature to identify a recurrent subset of HER2-positive and TNBC subtypes.
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A key component of the insect immune response is melanin production, including within nodules, or aggregations of immune cells surrounding microbes. Melanization produces oxidative and toxic intermediates that limit microbial infections. However, a direct fungicidal role of melanin during infection has not been demonstrated. We previously reported that the fungus Cryptococcus neoformans is encapsulated with melanin within nodules of Galleria mellonella hosts. Here we developed techniques to study melanin's role during C. neoformans infection in G. mellonella. We provided evidence that in vivo melanin-encapsulation was fungicidal. To further study immune melanization, we applied tissue-clearing techniques to visualize melanized nodules in situ throughout the larvae. Further, we developed a time-lapse microscopy protocol to visualize the melanization kinetics in extracted hemolymph following fungal exposure. Using this technique, we found that cryptococcal melanin and laccase enhance immune melanization. We extended this approach to study the fungal pathogens Candida albicans and Candida auris. We find that the yeast morphologies of these fungi elicited robust melanization responses, while hyphal and pseudohyphal morphologies were melanin-evasive. Approximately 23% of melanin-encapsulated C. albicans yeast can survive and breakthrough the encapsulation. Overall, our results provide direct evidence that immune melanization functions as a direct antifungal mechanism in G. mellonella.
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Criptococosis , Cryptococcus neoformans , Fungicidas Industriales , Mariposas Nocturnas , Animales , Criptococosis/microbiología , Candida albicans , Hemolinfa , MelaninasRESUMEN
Individuals who have shown recovery from coronavirus disease (COVID-19) are increasingly getting diagnosed with Mucormycosis or "Black fungus." It is a difficult condition to diagnose as it has symptoms that are common among a variety of diseases. Hence, it is important to identify the presenting signs and understand the underlying pathogenesis of COVID-19 associated Mucormycosis. The incidence of these mycotic infections has shown a substantial increase in current times owing to an increase in the prevalence of immunocompromised subjects, human immunodeficiency virus (HIV) infection, and acquired immunodeficiency syndrome (AIDS). Any suspected case of mucormycosis requires rapid diagnosis and management due to its rapid progression as well as the destructive course of infection. This article reviews the taxonomy, pathogenesis, and clinical signs along with laboratory investigations that may play a vital role in the timely diagnosis of this condition as it is mostly fatal.
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Background: Both dermatoglyphic and cheiloscopic patterns are genetically determined. These patterns are known to be associated with type II diabetes or diabetes mellitus and hypertension which are also considered to have genetic influence due to their familial occurrence. Hence, the aim of this study was to compare reliability of both cheiloscopy and dermatoglyphics with hypertension and type II diabetes. Materials and Methods: This was a prospective study conducted on 300 study participants. Both cheiloscopic and dermatoglyphic patterns were recorded using validated techniques. Obtained patterns were analyzed and assessed for statistical analysis using the SPSS version 21.0 statistical software. The Chi-square test was used for analyzing the obtained data. Results: In the present study, no statistical correlation was obtained between either dermatoglyphic or cheiloscopic patterns and type II diabetes or hypertension. Conclusion: The present study showed that cheiloscopy or dermatoglyphics cannot be used as a predictive tool for assessing a subject's risk of developing type II diabetes or hypertension. These are contradictory findings, thus emphasizing more research in this area so that these noninvasive techniques can be used as predictive tools for developing essential hypertension or type II diabetes.
Résumé Contexte: Les modèles dermatoglyphiques et cheiloscopiques sont génétiquement déterminés. Ces modèles sont connus pour être associés au diabète de type II ou au diabète sucré et à l'hypertension qui sont également considérés comme ayant une influence génétique en raison de leur occurrence familiale.Par conséquent, le but de cette étude était de comparer la fiabilité de la cheiloscopie et des dermatoglyphes avec l'hypertension et le diabète de type II. Matériaux et méthodes: Il s'agissait d'une étude prospective menée auprès de 300 participants à l'étude.Les modèles cheiloscopiques et dermatoglyphiques ont été enregistrés utilisant des techniques validées.Les modèles obtenus ont été analysés et évalués pour analyse statistique à l'aide du logiciel statistique SPSS version 21.0.Le test Chi-square a été utilisé pour analyser les données obtenues. Résultats: Dans la présente étude, aucune corrélation statistique n'a été obtenue entre les modèles dermatoglyphiques ou cheiloscopiques et le diabète ou l'hypertension de type II. Conclusion: La présente étude a montré que la chéiloscopie ou les dermatoglyphes ne peuvent pas être utilisés comme outil prédictif pour évaluer le risque de développer le diabète ou l'hypertension de type II d'un sujet.Ce sont des résultats contradictoires, mettant ainsi l'accent sur plus de recherche dans ce domaine afin que ces techniques non invasives puissent être utilisées comme outils prédictifs pour développer l'hypertension essentielle ou le diabète de type II. Mots clés: Dermatoglyphes, hypertension, empreintes de lèvres, diabète de type II.
Asunto(s)
Diabetes Mellitus Tipo 2 , Hipertensión , Dermatoglifia , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/genética , Humanos , Estudios Prospectivos , Reproducibilidad de los ResultadosRESUMEN
OBJECTIVES: Evaluation of tumor-infiltrating lymphocytes (TILs) distribution in an Indian cohort of breast cancer patients for its prognostic significance. METHODS: A retrospective cohort of breast cancer patients from a single onco-surgeon's breast cancer clinic with a uniform treatment strategy was evaluated for TILs. Tumor sections were H&E stained and scored for the spatial distribution and percent stromal TILs infiltration by a certified pathologist. The scores were analysed for association with treatment response and survival outcomes across molecular subtypes. RESULTS: Total 229 breast cancer tumors were evaluated. Within spatial distribution categories, intra-tumoral TILs were observed to be associated with complete pathological response and lower recurrence frequency for the entire cohort. Subtype-wise analysis of stromal TILs (sTILs) re-enforced significantly higher infiltration in TNBC compared to HER2-positive and ER-positive tumors. A favourable association of higher stromal infiltration was observed with treatment response and disease outcomes, specifically in TNBC. CONCLUSION: Intra-tumoral TILs showed a higher proportion with favourable association with better patient outcomes in an Indian cohort, unlike western cohorts where both stromal and intra-tumoral TILs show similar association with prognosis. With further validation, TILs can be developed as a cost-effective surrogate marker for treatment response, especially in a low-resource setting such as India.