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AB598 is a CD39 inhibitory antibody being pursued for the treatment of solid tumors in combination with chemotherapy and immunotherapy. CD39 metabolizes extracellular ATP (eATP), an alarmin capable of promoting anti-tumor immune responses, into adenosine, an immuno-inhibitory metabolite. By inhibiting CD39, the consumption of eATP is reduced, resulting in a pro-inflammatory milieu in which eATP can activate myeloid cells to promote anti-tumor immunity. The preclinical characterization of AB598 provides a mechanistic rationale for combining AB598 with chemotherapy in the clinic. Chemotherapy can induce ATP release from tumor cells and, when preserved by AB598, both chemotherapy-induced eATP and exogenously added ATP promote the function of monocyte-derived dendritic cells via P2Y11 signaling. Inhibition of CD39 in the presence of ATP can promote inflammasome activation in in vitro-derived macrophages, an effect mediated by P2X7. In a MOLP8 murine xenograft model, AB598 results in full inhibition of intratumoral enzymatic activity, an increase in intratumoral ATP, a decrease of extracellular CD39 on tumor cells, and ultimately, control of tumor growth. In cynomolgus monkeys, systemically dosed AB598 results in effective enzymatic inhibition in tissues, full peripheral and tissue target engagement, and a reduction in cell surface CD39 both in tissues and in the periphery. Taken together, these data support a promising therapeutic strategy of harnessing the eATP generated by standard-of-care chemotherapies to prime the tumor microenvironment for a productive anti-tumor immune response.
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T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) is an inhibitory receptor on immune cells that outcompetes an activating receptor, CD226, for shared ligands. Tumor-infiltrating lymphocytes express TIGIT and CD226 on regulatory T cells (Treg) and on CD8+ T cells with tumor-reactive or exhausted phenotypes, supporting the potential of therapeutically targeting TIGIT to enhance antitumor immunity. To optimize the efficacy of therapeutic antibodies against TIGIT, it is necessary to understand IgG Fc (Fcγ) receptor binding for therapeutic benefit. In this study, we showed that combining Fc-enabled (Fce) or Fc-silent (Fcs) anti-TIGIT with antiprogrammed cell death protein 1 in mice resulted in enhanced control of tumors by differential mechanisms: Fce anti-TIGIT promoted the depletion of intratumoral Treg, whereas Fcs anti-TIGIT did not. Despite leaving Treg numbers intact, Fcs anti-TIGIT potentiated the activation of tumor-specific exhausted CD8+ populations in a lymph node-dependent manner. Fce anti-TIGIT induced antibody-dependent cell-mediated cytotoxicity against human Treg in vitro, and significant decreases in Treg were measured in the peripheral blood of patients with phase I solid tumor cancer treated with Fce anti-TIGIT. In contrast, Fcs anti-TIGIT did not deplete human Treg in vitro and was associated with anecdotal objective clinical responses in two patients with phase I solid tumor cancer whose peripheral Treg frequencies remained stable on treatment. Collectively, these data provide evidence for pharmacologic activity and antitumor efficacy of anti-TIGIT antibodies lacking the ability to engage Fcγ receptor. SIGNIFICANCE: Fcs-silent anti-TIGIT antibodies enhance the activation of tumor-specific pre-exhausted T cells and promote antitumor efficacy without depleting T regulatory cells.
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Receptores Inmunológicos , Linfocitos T Reguladores , Animales , Linfocitos T Reguladores/inmunología , Ratones , Receptores Inmunológicos/inmunología , Receptores Inmunológicos/antagonistas & inhibidores , Humanos , Linfocitos Infiltrantes de Tumor/inmunología , Femenino , Linfocitos T CD8-positivos/inmunología , Ratones Endogámicos C57BL , Línea Celular Tumoral , Neoplasias/inmunología , Neoplasias/tratamiento farmacológicoRESUMEN
BACKGROUND AND OBJECTIVE: The therapeutic use of vildagliptin and insulin (VIL-INS) or vildagliptin and metformin in combination with insulin (VIL-MET-INS) in the Indian scenario has yet to be explored by generating real-world evidence. Therefore, the present study aimed to evaluate the demographic, clinical characteristics, and treatment patterns of patients with type 2 diabetes mellitus (T2DM) in Indian settings in the above context. METHODOLOGY: This observational study conducted at 600 healthcare centers in India retrospectively analyzed data of adult patients with T2DM who had been treated with either vildagliptin with insulin or a combination of vildagliptin and metformin with insulin. Data were collected from medical records and analyzed by appropriate statistical tests. RESULTS: A total of 12,603 patients with T2DM were included with a mean age of 53.4 years of which 63.8% were males. The majority of patients (n=6511; 51.7%) received a combination of vildagliptin and metformin on top of insulin. A significantly high proportion of patients in the age group of 18-40 years received this treatment compared to patients who were initiated on insulin treatment after vildagliptin and metformin combination (11.6% vs. 9.7%; P<0.001). Of all the patients, 70.0% were able to achieve target glycemic control with either VIS-INS or VIL-MET-INS. After treatment with VIL-INS or VIL-MET-INS, the mean glycated hemoglobin (HbA1c) levels significantly decreased with a mean change of 1.46%. Out of all patients, 13.5% experienced weight changes during treatment, with 67.4% of them showing weight loss. A total of 68 patients reported hypoglycemic events and among them, 49 patients had mild hypoglycemic events. Physician global evaluation of efficacy and tolerability showed a majority of patients rated their experience as good to excellent (86.3% and 86.0%, respectively). CONCLUSION: Both treatment regimens were effective in terms of reduced HbA1c to achieve glycemic control. Furthermore, it is well tolerated without an increase in the risk of hypoglycemia or weight gain. Hence, this therapy has favorable outcomes for T2DM management in Indian clinical settings.
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Phosphoinositide-3-kinase γ (PI3Kγ) is highly expressed in immune cells and promotes the production and migration of inflammatory mediators. The inhibition of PI3Kγ has been shown to repolarize the tumor immune microenvironment to a more inflammatory phenotype, thereby controlling immune suppression in cancer. Herein, we report the structure-based optimization of an early lead series of pyrazolopyrimidine isoindolinones, which culminated in the discovery of highly potent and isoform-selective PI3Kγ inhibitors with favorable drug-like properties. X-ray cocrystal structure analysis, molecular docking studies, and detailed structure-activity relationship investigations resulted in the identification of the optimal amide and isoindolinone substituents to achieve a desirable combination of potency, selectivity, and metabolic stability. Preliminary in vitro studies indicate that inhibition of PI3Kγ with compound 56 results in a significant immune response by increasing pro-inflammatory cytokine gene expression in M1 macrophages.
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Amidas/química , Fosfatidilinositol 3-Quinasa Clase Ib/química , Diseño de Fármacos , Descubrimiento de Drogas , Inhibidores de las Quinasa Fosfoinosítidos-3/farmacología , Pirimidinas/química , Animales , Humanos , Masculino , Simulación del Acoplamiento Molecular , Ratas , Ratas Sprague-Dawley , Relación Estructura-ActividadRESUMEN
The current method of agriculture entails the usage of excessive amounts of pesticides and fertilizers. The blatant use of conventional pesticides and fertilizers over several decades has led to their bioaccumulation with adverse effects on soil biodiversity and the development of resistance by pests. With the decline in clinically useful antibiotics and increase in multi drug resistant microbes, it is imperative to develop new and effective antimicrobial therapies. Growing awareness and demand for efficacious biorational pesticides are on the rise. Silver nanoparticles are widely known antimicrobials and have been in use for several purposes for a long time. This work reviews the implications of applying silver nanoparticles in agriculture and their possible consequences. The physiological and biochemical changes in plants due to the uptake of silver nanoparticles as a consequence of its morphology, capping biomolecules and method of application are comprehensively discussed in this review article. Studies on tolerance levels or stress due to silver nanoparticles by variation in concentration/doses on diverse flora and fauna are also analyzed here. Further, phytotoxicity and genotoxicity due to the metal as well as its transformation in soil, water and sludge are taken into account. We also gauge the potential of biogenic silver nanoparticles-viable antimicrobial agents for enhanced applications in agriculture as biopesticides.
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Nanopartículas del Metal , Plata , Agentes de Control Biológico , Fertilizantes , Nanopartículas del Metal/toxicidad , Estudios Prospectivos , Plata/toxicidadRESUMEN
Hyptis suaveolens is considered one of the most potent invaders in the eastern part of Uttar Pradesh, India. Climate change especially precipitation variability along with invasion has enormous consequences. To understand how an invasive plant (H. suaveolens) performs and interacts with precipitation variability, particularly in tropical monsoon climate, is vital. To assess the above, three rainout shelters with simulated rainfall of 1600 mm (60% more rainfall than ambient), 1100 mm (average rainfall) and 800 mm (20% less rainfall than ambient) along with one unsheltered plot (open C) were established. Three invaded grassland (IG) and three uninvaded grasslands (NIG) patches of 1 × 1 m2 size were established randomly in each sheltered and unsheltered plot. Among the studied physiological properties and growth measurements, photosynthetic rate, height, diameter and biomass varied significantly with precipitation, in general, the maximum value of these in plots receiving maximum precipitation. Also, the aboveground biomass of H. suaveolens was found to be more sensitive towards precipitation treatment than belowground biomass. H. suaveolens biomass was linearly related to soil moisture (R2 = 0.73), and a linear combination of SM and soil pH increased the R2 value by 19%. The results indicate that H. suaveolens mediates certain soil properties especially related to N-mineralisation, to maintain a constant supply of nutrient, for faster growth under the favourable condition of enhanced precipitation. These findings suggest that the population of H. suaveolens has not evolved drought tolerance, so it is likely that H. suaveolens will not spread in the part of the world which is drier either naturally or due to climate change.
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Pradera , Hyptis , Biomasa , Monitoreo del Ambiente , India , LluviaRESUMEN
BACKGROUND: Human height is a classic polygenic trait and currently available data explains only 10% of the phenotypic variation in height. Almost 60%-80% of the children coming to pediatric and endocrinology outpatient department for the evaluation of short stature are still labeled as idiopathic. OBJECTIVES: The aim of this study is to identify various chromosomal alterations causing idiopathic short stature (ISS) and short stature with dysmorphic features not pertaining to known genetic syndromes. MATERIALS AND METHODS: After exclusion of all nutritional, systemic, endocrine, and syndromic causes of short stature, 19 patients with height <2 standard deviation scores were subjected to chromosomal microarray (CMA) study using Affymetrix CytoScan 750K array and CMA Scanner 3000 platform. RESULTS: We identified total 61 copy-number variant (CNV) and polymorphs (33 gains, 11 loss, and 17 gain-mosaics) not described as normal variants in database of genomic variations. We identified SHOX haploinsufficiency as a cause of short stature in two patients, whereas one patient was gain-mosaic for SHOX. All three had normal conventional karyotype. One of these patients also had deletion of PAX3, which could be the cause of both short stature and associated mild intellectual impairment in this patient. We also found a long noncoding RNA, namely, KIAA0125 and a pseudogene ADAM6 in 18 out of our 19 patients which might have a regulatory role. CONCLUSION: This study shows that CMA is a very promising tool for the identification of pathogenic CNVs in patients with ISS. It can also help to identify novel genes controlling height and can open up new insight into pathophysiologic mechanisms underlying ISS, and thus may help to unfold new therapeutic targets for treatment of this condition. The association of CNV having genes for long noncoding RNAs, such as KIAA0125 and pseudogene such as ADAM6 with ISS suggest that they may play a role in controlling the expression of height-related genes and it needs further investigations.
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BACKGROUND AND OBJECTIVE: Type 2 diabetes mellitus (T2DM) may affect bone loss differentially in adult males and postmenopausal females. We evaluated the prevalence of osteoporosis in otherwise healthy adults with T2DM. MATERIALS AND METHODS: In a cross-sectional study, adults with T2DM, aged 50 years and above, were evaluated for bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA) scan at spine and hip. T-score of ≤-2.5 was defined as osteoporosis and score -2.49 to -1.0 as osteopenia at either site. Correlation of low BMD with demographic, clinical, and laboratory parameters including serum Vitamin D and serum testosterone (in males) was evaluated. RESULTS: In 200 patients, mean age was 64.5 ± 7.0 years and age differed significantly in males and females (P < 0.0001). Osteoporosis was present in 35.5% adults with T2DM. Significantly greater proportion of females had osteoporosis (49.5% vs. 22.3%, P < 0.0001). Frequency of osteoporosis at spine (33.5%) was higher than the same at hip (13.5%). Compared to males, significantly greater proportion of females had osteoporosis and osteopenia at both spine (P < 0.0001) and hip (P < 0.0001). Among all parameters assessed, a significant positive correlation of T-score at spine and hip was seen with body mass index in both males (r = 0.287, P = 0.003 at spine and r = 0.421, P < 0.0001 at hip) and females (r = 0.291, P = 0.004 at spine and r = 0.280, P = 0.010 at hip). There was no association of Vitamin D deficiency (45.5% patients) with either T-score and presence of osteoporosis either at spine (P = 0.388 and P = 0.177) or hip (P = 0.431 and P = 0.593). CONCLUSION: Prevalence of osteoporosis in otherwise healthy T2DM was 35.5% with greater prevalence in females than males. Body mass but not Vitamin D or testosterone has an important role in the determination of bone loss in T2DM.
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BACKGROUND: To describe the prevalence of missing teeth, use of bridges and dentures and unmet dental needs among those aged 60 years and above. The associations of these conditions with socio-demographics, type 2 diabetes mellitus and depression were also studied. The work was carried out in 7 Latin American and Caribbean (LAC) cities in 1999-2000. METHODS: A secondary analysis was conducted on the Survey of Health and Well-Being of Elders (SABE) dataset. The 7 cities were Buenos Aires, Bridgetown, São Paulo, Santiago, Havana, Mexico City and Montevideo. This survey did not employ any oral examinations. Descriptive statistics, chi-square and regression analysis were used to test for associations. RESULTS: Data for 10 902 persons were analyzed. Females made up 62% of the population. Across the SABE population, between 93.7% (Mexico City) to 99.9% (Santiago) reported missing teeth, with an average of 97.5%. Of those with missing teeth, between 55.1% (Mexico City) and 82.4% (São Paulo) reported having bridges or dentures, with an average of 70.1% across all SABE cities. The proportion of the SABE population with 'unmet dental needs' ranged from 85.8% (Santiago) to 98.4% (Havana), with an average of 94.5%. Bridgetown, São Paulo and Mexico City demonstrated a statistically significant association between aging and tooth loss. Generally a greater proportion of females (97.6%) reported tooth loss compared with males (96.8%), but in only São Paulo and Montevideo was there a statistically significant association between sex and tooth loss. Generally those with higher education reported less tooth loss, primary education (97.6% had tooth loss), secondary (96.8%) and tertiary (94.7%). All the SABE cities except Buenos Aires demonstrated a statistically significant association between tooth loss and education. CONCLUSIONS: The prevalence of missing teeth, use of bridges and dentures and unmet dental needs were high in the SABE cities in 1999-2000. In general across the SABE cities, the elderly with the most missing teeth were less educated or less likely to be a professional. They tended to be not working and were receiving a pension. Additionally they were less likely to report their health as 'excellent', were diabetic and were more likely to give responses suggestive of depression.
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Dentadura Completa/estadística & datos numéricos , Dentadura Parcial/estadística & datos numéricos , Salud Bucal/estadística & datos numéricos , Pérdida de Diente/epidemiología , Factores de Edad , Anciano , Anciano de 80 o más Años , Actitud Frente a la Salud , Región del Caribe/epidemiología , Estudios Transversales , Depresión/epidemiología , Diabetes Mellitus Tipo 2/epidemiología , Escolaridad , Empleo/estadística & datos numéricos , Femenino , Humanos , América Latina/epidemiología , Masculino , Estado Civil , Persona de Mediana Edad , Evaluación de Necesidades/estadística & datos numéricos , Ocupaciones/estadística & datos numéricos , Pensiones/estadística & datos numéricos , Factores Sexuales , Factores Socioeconómicos , Salud Urbana/estadística & datos numéricosRESUMEN
The objective of this research was to compare selected ecophysiological parameters for a wheat crop found in the Indo-Gangetic Plains of India and its five dominant weeds. The dominant and regionally ubiquitous weeds in the wheat field that was selected for the study were Anagallis arvensis, Chenopodium album, Melilotus albus, Phalaris minor and Rumex dentatus. Taller weeds, such as C. album and P. minor, constituted one group along with the crop, with a low photosynthetic rate, specific leaf area, leaf nitrogen mass basis, chlorophyll content, photosynthetic nitrogen-use efficiency and leaf area ratio, in comparison to shorter weeds, such as A. arvensis, M. albus and R. dentatus, which formed another group with a high photosynthetic rate, specific leaf area, leaf nitrogen mass basis, chlorophyll content, photosynthetic nitrogen-use efficiency and leaf area ratio. Interspecific variations in the photosynthetic rate were driven mainly by variability in the specific leaf area and leaf nitrogen content. The taller weeds and the crop had a low specific leaf area later in the season, whereas the smaller weeds had a relatively high specific leaf area, which might be an adaptation to the shaded environment below the canopy. The result indicates that any weed management in the wheat fields of the Indo-Gangetic Plains will need two different approaches because of the different strategies followed by the two weed groups that were identified in the present study.
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AIMS AND OBJECTIVES: To describe the diversity of clinical manifestations, laboratory findings and outcome of scrub typhus in hospitalised patients of SMS Hospital, Jaipur during 2012 and 2013. MATERIAL AND METHODS: All the cases of febrile illness with thrombocytopenia diagnosed as scrub typhus were analysed. Diagnosis was made by ELISA based IgM serology. OBSERVATIONS AND RESULTS: A total of 125 patients were studied. All of them presented with fever; the other major symptoms were headache, cough, dyspnoea and myalgias. On examination, patients had hepatosplenomegaly, lymphadenopathy and eschar. On investigation elevated SGOT, SGPT with normal or elevated bilirubin levels were the most common findings. Other laboratory findings were thrombocytopenia and deranged renal function tests. Most common X-ray finding observed in these patients was bilateral lung infiltrates. Other complications were MODS, ARDS, hypotension and meningoencephalitis. Majority responded to doxycycline. CONCLUSION: Scrub typhus though prevalent is under-reported in our country. It should be considered as an important differential diagnosis in a febrile patient with thrombocytopenia, deranged liver or renal functions, and B/L chest opacities. Early diagnosis and appropriate treatment is rewarding and prevents morbidity and mortality.
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Brotes de Enfermedades , Tifus por Ácaros/epidemiología , Adulto , Femenino , Fiebre/etiología , Humanos , India/epidemiología , Masculino , Embarazo , Tifus por Ácaros/complicaciones , Tifus por Ácaros/diagnóstico , Trombocitopenia/etiologíaRESUMEN
Dust is considered as one of the most widespread air pollutants. The objective of the study was to analyse the effect of dust load (DL) on the leaf attributes of the four tree species planted along the roadside at a low pollution Banaras Hindu University (BHU) campus and a highly polluted industrial area (Chunar, Mirzapur) of India. The studied leaf attributes were: leaf area, specific leaf area (SLA), relative water content (RWC), leaf nitrogen content (LNC), leaf phosphorus content (LPC), chlorophyll content (Chl), maximum stomatal conductance (Gs(max)), maximum photosynthetic rate (A (max)) and intrinsic water-use efficiency (WUEi). Results showed significant effect of sites and species for DL and the leaf attributes. Average DL across the four tree species was greater at Chunar, whereas, the average values of leaf attributes were greater at the BHU campus. Maximum DL was observed for Tectona grandis at Chunar site and minimum for Syzygium cumini at BHU campus. Across the two sites, maximum value of SLA, Chl and Gs(max) were exhibited by S. cumini, whereas, the greatest value of RWC, LNC, LPC, A (max) and WUEi were observed in Anthocephalus cadamba. A. cadamba and S. cumini exhibited 28 and 27 times more dust accumulation, respectively, at the most polluted Chunar site as compared to the BHU campus. They also exhibited less reduction in A (max) due to dust deposition as compared to the other two species. Therefore, both these species may be promoted for plantation along the roadside of the sites having greater dust deposition.
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Contaminantes Atmosféricos/análisis , Polvo/análisis , Hojas de la Planta/fisiología , Árboles/fisiología , Automóviles/estadística & datos numéricos , Clorofila/metabolismo , Monitoreo del Ambiente , India , Fotosíntesis/fisiología , Hojas de la Planta/metabolismo , Estomas de Plantas/fisiología , Árboles/metabolismoRESUMEN
Morphological (easily measureable) and physiological (hard to measure) traits of two closely related invasive alien congeners-Ageratum conyzoides L. and Ageratum houstonianum Mill. were studied with a perspective that which species will be potentially be more successful as an invader in the Indo-Gangetic plains of India. Leaf construction cost (LCC) is considered as a quantifiable measure of energy demand for biomass production and is related to energy use efficiency as it include component of both morphological and physiological traits. We hypothesised that a low LCC would give the invaders growth advantage by utilizing energy efficiently. Low LCC of A. houstonianum on mass basis (0.54 g glucose g( -1)) and area basis (20.48 g m( -2)) gives insight into the success of this invasive weed over A. conyzoides. The present study gives evidence that how the morphological traits are linked to physiological traits that could directly affect invasive attributes of the invader, which in turn would be crucial to prioritize species for ecosystem management.
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Ageratum/fisiología , Especies Introducidas , Malezas/fisiología , Ageratum/crecimiento & desarrollo , Conservación de los Recursos Naturales , India , Malezas/crecimiento & desarrolloRESUMEN
Hexamine is known to assist anisotropic growth of metal oxides and the same is also found to be true for magnetite nanosynthesis. In this work we elucidate the role of hexamine and other precursors in the formation of magnetite nanorods by the hydrothermal route and their stoichiometry. Various others hydrolyzing agents such as sodium hydroxide (NaOH), sodium hydroxide + hexamine, ammonia (NH(3)), ammonia + formaldehyde are also studied. The synthesized nanoparticles are characterized with the help of various techniques such as X-ray diffraction (XRD), FT-IR spectroscopy, UV-VIS-NIR spectroscopy, transmission electron microscopy (TEM), Mössbauer spectroscopy and SQUID magnetization measurements. It is found that only when ferric chloride, ferrous ammonium sulfate (FAS) and hexamine are used, well defined nanorods are formed. When sodium hydroxide and hexamine are used as a hydrolyzing system nearly spherical nanoparticles with small size (approximately 13 nm) are formed, as compared to the case of sodium hydroxide alone which leads to bigger cube like nanoparticles. Interestingly the decomposition products of hexamine do not lead to nanorod formation. Thus, slow decomposition of hexamine at elevated temperature and the consequent slow rise in pH is the key to the anisotropic growth of the iron oxide system.
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We report on the synthesis of iron oxide nanoparticles below 100 degrees C by a simple chemical protocol. The uniqueness of the method lies in the use of Ferrous ammonium sulphate (in conjugation with FeCl3) which helps maintain the stability of Fe2+ state in the reaction sequence thereby controlling the phase formation. Hexamine was added as the stabilizer. The nanoparticles synthesized at three different temperatures viz, 5 degrees, 27 degrees, and 95 degrees C are characterized by several techniques. Generally, when a mixture of Fe3+ and Fe2+ is added to sodium hydroxide, alpha-Fe2O3 (the anti-ferromagnetic phase) is formed after the dehydration process of the hydroxide. In our case however, the phases formed at all the three temperatures were found to be ferro (ferri) magnetic, implying modification of the formation chemistry due to the specifics of our method. The nanoparticles synthesized at the lowest temperature exhibit magnetite phase, while increase in growth temperature to 95 degrees C leads to the maghemite phase.
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Development is a dynamic process that includes an intricate balance between an increase in cell mass and an elimination of excess or defective cells. Although caspases have been intimately linked to apoptotic events, there are a few reports suggesting that these cysteine proteases can influence the differentiation and proliferation of cells. Specifically, the active form of caspase-3, which has been classified as an executor of apoptosis, recently has been implicated in a nonapoptotic role in the regulation of the cell cycle, cell proliferation, and cell differentiation. This study investigated the nonapoptotic function and phenotypic expression of active caspase-3-positive cells in the external granule cell layer (EGL) of the postnatal rat cerebellum by using biochemical and immunohistochemical analyses, respectively. Evidence that negates an apoptotic function for the caspase-3-positive EGL cells includes a failure to exhibit chromatin condensation (assessed with TOPRO), phosphatidyl serine externalization (Annexin V labeling), or DNA fragmentation (TUNEL labeling). Proliferative (Ki67-positive) and differentiated (TUJ1-positive) cells within the EGL exhibited a cytosolic expression of caspase-3, whereas terminally differentiated granule cells (NeuN-positive) in the internal granular layer and the migrating granule cells did not express active caspase-3. Thus, this study supports a nonapoptotic role for active caspase-3 in cells residing in the EGL and suggests a possible involvement in EGL proliferation and differentiation.
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Envejecimiento/metabolismo , Animales Recién Nacidos/metabolismo , Apoptosis , Caspasas/metabolismo , Cerebelo/enzimología , Cerebelo/crecimiento & desarrollo , Ratas/metabolismo , Animales , Animales Recién Nacidos/crecimiento & desarrollo , Biomarcadores/análisis , Caspasa 3 , Núcleo Celular/ultraestructura , Corteza Cerebelosa/citología , Corteza Cerebelosa/enzimología , Corteza Cerebelosa/fisiología , Cerebelo/fisiología , Femenino , Histocitoquímica , Masculino , Fenotipo , Ratas/crecimiento & desarrollo , Ratas Sprague-DawleyRESUMEN
Cerebellar Purkinje neurons (PNs) are selectively vulnerable to AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepriopionic acid)-induced delayed neurotoxicity known as dark cell degeneration (DCD) that is expressed as cytoplasmic and nuclear condensation, neuron shrinkage, and failure of physiology. The present study was initiated to determine whether AMPA-receptor-induced DCD in PNs is associated with Bax translocation to the mitochondria, cytochrome C release from the mitochondria, changes in mitochondrial potential, and activation of representative initiator and executor caspases that include caspase-9, caspase-3, and caspase-7. AMPA consistently and rapidly hyperpolarized mitochondria as reflected by an increase in MitoTracker Red CMS Ros fluorescence. Increases in Bax immunoreactivity were quantitatively and temporally variable and Bax failed to localize to mitochondria. Additionally, we observed a marked increase in immunoreactivity of cytochrome C although its release from mitochondria was not apparent. Mitochondrial membrane hyperpolarization and increases in cytochrome C immunoreactivity preceded caspase activation. Immunohistochemical analyses revealed the active form of caspases-3 and -9 were markedly and significantly increased in PNs following 30 microM AMPA, and caspase-9 activation preceded caspase-3. Increases in active caspase-7 immunoreactivity were less frequently encountered in PNs. Thus DCD shares some characteristics of apoptotic programmed cell death, but lacks typical mitochondrial pathophysiology associated with classic apoptosis. These findings suggest that AMPA-induced DCD is a form of active PCD that lies on a spectrum between classical apoptosis and passive necrosis.