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1.
Cell ; 158(3): 534-48, 2014 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-25018104

RESUMEN

Depending on endoplasmic reticulum (ER) stress levels, the ER transmembrane multidomain protein IRE1α promotes either adaptation or apoptosis. Unfolded ER proteins cause IRE1α lumenal domain homo-oligomerization, inducing trans autophosphorylation that further drives homo-oligomerization of its cytosolic kinase/endoribonuclease (RNase) domains to activate mRNA splicing of adaptive XBP1 transcription factor. However, under high/chronic ER stress, IRE1α surpasses an oligomerization threshold that expands RNase substrate repertoire to many ER-localized mRNAs, leading to apoptosis. To modulate these effects, we developed ATP-competitive IRE1α Kinase-Inhibiting RNase Attenuators-KIRAs-that allosterically inhibit IRE1α's RNase by breaking oligomers. One optimized KIRA, KIRA6, inhibits IRE1α in vivo and promotes cell survival under ER stress. Intravitreally, KIRA6 preserves photoreceptor functional viability in rat models of ER stress-induced retinal degeneration. Systemically, KIRA6 preserves pancreatic ß cells, increases insulin, and reduces hyperglycemia in Akita diabetic mice. Thus, IRE1α powerfully controls cell fate but can itself be controlled with small molecules to reduce cell degeneration.


Asunto(s)
Estrés del Retículo Endoplásmico , Endorribonucleasas/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Regulación Alostérica , Animales , Apoptosis/efectos de los fármacos , Línea Celular , Endorribonucleasas/química , Endorribonucleasas/metabolismo , Activación Enzimática/efectos de los fármacos , Humanos , Islotes Pancreáticos/metabolismo , Masculino , Ratones , Proteínas Serina-Treonina Quinasas/química , Proteínas Serina-Treonina Quinasas/metabolismo , Ratas , Retina/metabolismo , Ribonucleasas/antagonistas & inhibidores
2.
Nature ; 583(7815): 211-214, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32641814

RESUMEN

The discovery of a radioactively powered kilonova associated with the binary neutron-star merger GW170817 remains the only confirmed electromagnetic counterpart to a gravitational-wave event1,2. Observations of the late-time electromagnetic emission, however, do not agree with the expectations from standard neutron-star merger models. Although the large measured ejecta mass3,4 could be explained by a progenitor system that is asymmetric in terms of the stellar component masses (that is, with a mass ratio q of 0.7 to 0.8)5, the known Galactic population of merging double neutron-star systems (that is, those that will coalesce within billions of years or less) has until now consisted only of nearly equal-mass (q > 0.9) binaries6. The pulsar PSR J1913+1102 is a double system in a five-hour, low-eccentricity (0.09) orbit, with an orbital separation of 1.8 solar radii7, and the two neutron stars are predicted to coalesce in [Formula: see text] million years owing to gravitational-wave emission. Here we report that the masses of the pulsar and the companion neutron star, as measured by a dedicated pulsar timing campaign, are 1.62 ± 0.03 and 1.27 ± 0.03 solar masses, respectively. With a measured mass ratio of q = 0.78 ± 0.03, this is the most asymmetric merging system reported so far. On the basis of this detection, our population synthesis analysis implies that such asymmetric binaries represent between 2 and 30 per cent (90 per cent confidence) of the total population of merging binaries. The coalescence of a member of this population offers a possible explanation for the anomalous properties of GW170817, including the observed kilonova emission from that event.

3.
Phys Rev Lett ; 131(17): 171001, 2023 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-37955508

RESUMEN

Pulsar Timing Array experiments probe the presence of possible scalar or pseudoscalar ultralight dark matter particles through decade-long timing of an ensemble of galactic millisecond radio pulsars. With the second data release of the European Pulsar Timing Array, we focus on the most robust scenario, in which dark matter interacts only gravitationally with ordinary baryonic matter. Our results show that ultralight particles with masses 10^{-24.0} eV≲m≲10^{-23.3} eV cannot constitute 100% of the measured local dark matter density, but can have at most local density ρ≲0.3 GeV/cm^{3}.

4.
Nat Chem Biol ; 17(11): 1148-1156, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34556859

RESUMEN

The unfolded protein response (UPR) homeostatically matches endoplasmic reticulum (ER) protein-folding capacity to cellular secretory needs. However, under high or chronic ER stress, the UPR triggers apoptosis. This cell fate dichotomy is promoted by differential activation of the ER transmembrane kinase/endoribonuclease (RNase) IRE1α. We previously found that the RNase of IRE1α can be either fully activated or inactivated by ATP-competitive kinase inhibitors. Here we developed kinase inhibitors, partial antagonists of IRE1α RNase (PAIRs), that partially antagonize the IRE1α RNase at full occupancy. Biochemical and structural studies show that PAIRs promote partial RNase antagonism by intermediately displacing the helix αC in the IRE1α kinase domain. In insulin-producing ß-cells, PAIRs permit adaptive splicing of Xbp1 mRNA while quelling destructive ER mRNA endonucleolytic decay and apoptosis. By preserving Xbp1 mRNA splicing, PAIRs allow B cells to differentiate into immunoglobulin-producing plasma cells. Thus, an intermediate RNase-inhibitory 'sweet spot', achieved by PAIR-bound IRE1α, captures a desirable conformation for drugging this master UPR sensor/effector.


Asunto(s)
Adenosina Trifosfato/farmacología , Endorribonucleasas/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Adenosina Trifosfato/química , Endorribonucleasas/metabolismo , Humanos , Modelos Moleculares , Estructura Molecular , Inhibidores de Proteínas Quinasas/química , Proteínas Serina-Treonina Quinasas/metabolismo , Desplegamiento Proteico/efectos de los fármacos
5.
BMC Psychiatry ; 22(1): 569, 2022 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-35999535

RESUMEN

BACKGROUND: Well-being is an important aspect of people's lives and can be considered as an index of social progress. The Warwick Edinburgh Mental Well-being scale (WEMWBS) was developed to capture subjective mental well-being. It is a widely tested measure of mental well-being at the population level and has 14 items and a short-form with 7 items. This study was carried out to culturally validate and adapt the WEMWBS among a Sinhala speaking population in Sri Lanka. METHODS: A forward and backward translation of the scale into Sinhala was done followed by a cognitive interview. The translated and culturally adapted scale and other mental health scales were administered to a sample of 294 persons between the ages of 17-73 using a paper-based version (n = 210) and an online survey (n = 84). Internal consistency reliability and test-retest reliability were tested. Construct validity, and convergent and discriminant validity were assessed using the total sample. RESULTS: The translated questionnaire had good face and content validity. Internal consistency reliability was 0.91 and 0.84 for the 14-item and 7-item scales, respectively. Test-retest reliability over two weeks was satisfactory (Spearman r = 0.72 p < 0.001). Confirmatory factor analysis supported a one factor model. Convergent validity was assessed using WHO-5 well-being index (Spearman r = 0.67, p < 0.001), Patient Health Questionnaire (PHQ-9) (Spearman r = (-0.45), p < 0.001) and Kessler psychological distress scale (K10) (Spearman r = (-0.55), p < 0.001). CONCLUSIONS: The translated and culturally adapted Sinhala version of the WEMWBS has acceptable psychometric properties to assess mental well-being at the population level among the Sinhala speaking population in Sri Lanka.


Asunto(s)
Salud Mental , Traducciones , Adolescente , Adulto , Anciano , Humanos , Persona de Mediana Edad , Psicometría/métodos , Reproducibilidad de los Resultados , Sri Lanka , Encuestas y Cuestionarios , Adulto Joven
6.
BMC Public Health ; 22(1): 2330, 2022 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-36514064

RESUMEN

BACKGROUND: Data on adult asthma is scarce in Sri Lanka. The objective of this study was to estimate the prevalence of asthma and its symptoms in adult Sri Lankans.  METHODS: A cross-sectional study using a translated version of the European Community Respiratory Health Survey screening questionnaire on subjects ≥ 18 years from 7 provinces in Sri Lanka was conducted. The asthma was defined as "wheezing in the past 12 months (current wheeze)", self-reported asthma attack in the past 12 months or on current asthma medication use. RESULTS: Among 1872 subjects (45.1% males, 48.8% between 18-44 years of age), the prevalence of current wheeze was 23.9% (95%CI: 22.0%-25.9%), self-reported asthma was 11.8% (95%CI: 10.3%-13.2%) and current asthma medication use was 11.1% (95% CI: 9.6%-12.5%). The prevalences were higher in adults > 44 years, 31.4% positively responded to any of the above questions (95%CI: 29.3%-33.4%) and 60.9% of current wheezers did not report having asthma whilst 38.2% used asthma medication. Among current wheezers, 80.1% had at least one other symptom, cough being the commonest. Those with no current wheeze, self-reported asthma and on current asthma medication use, 30%, 35.9% and 36.6%, respectively, reported at least one other symptom. Smokers comprises 22% current wheezers, 20.6% of self-reported asthmatics and 18.7% of current asthma medication users. CONCLUSIONS: The prevalence of asthma in Sri Lankan adults is higher than the other South Asian countries and higher in the older age group. A significant percentage of symptomatic individuals did not report having asthma or being on medication.


Asunto(s)
Asma , Ruidos Respiratorios , Masculino , Adulto , Humanos , Anciano , Femenino , Prevalencia , Sri Lanka/epidemiología , Estudios Transversales , Asma/tratamiento farmacológico , Asma/epidemiología
7.
J Zoo Wildl Med ; 52(2): 437-444, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34130385

RESUMEN

Evaluation and improvement of immobilization methods are important for wildlife welfare and biodiversity conservation. The sedative and physiological effects of xylazine (50-110 mg per elephant; 0.09-0.15 mg/kg IM) were evaluated in 15 juvenile Asian elephants (Elephas maximus) in Sri Lanka. The time from xylazine injection until first sign of sedation, handling, and reversal with yohimbine (0.009-0.03 mg/kg IV) were recorded. Behavioral signs, level of sedation (no effect, light, moderate, or deep) and response to handling were assessed. Rectal temperature, pulse, and respiratory rates were recorded and arterial blood samples were analyzed 30 and 45 min after xylazine injection. The first sign of sedation occurred within 5-18 min. Standing sedation was induced in all elephants, but the level of sedation varied differently over time for each elephant. Twelve elephants remained standing throughout the sedation period, while 3 elephants became laterally recumbent. Sedative effects included lowered head and trunk, droopy ears, snoring, and penis protrusion. Pulse rate, respiratory rate, and rectal temperature ranged between 30-45 beats/min, 4-12 breaths/min, and 35.6-37.2°C, respectively, at 30 min after xylazine injection, and there were no changes over time. Pulmonary function and acid-base balance were adequate (range partial pressures of arterial oxygen 73-123 mmHg and carbon dioxide 33-52 mmHg, arterial hemoglobin oxygen saturation 96-99%, pH 7.34-7.54, lactate 0.9-2.5 mmol/L). Yohimbine was administered 46-110 min after the injection of xylazine, and the first sign of recovery occurred within 1-4 min. Resedation after reversal with yohimbine was observed in two elephants. In conclusion, xylazine at the doses used induced light to deep sedation with stable physiology and most elephants remained standing.


Asunto(s)
Sedación Consciente/veterinaria , Elefantes , Xilazina/farmacología , Yohimbina/farmacología , Antagonistas de Receptores Adrenérgicos alfa 2/farmacología , Animales , Femenino , Hipnóticos y Sedantes/farmacología , Masculino
8.
Health Qual Life Outcomes ; 18(1): 305, 2020 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-32912245

RESUMEN

PURPOSE: The WHO-5 well-being index is a widely used, short rating scale that measures subjective well-being. We translated the WHO-5 index into Sinhala and tested its psychometric properties including measurement invariance among diverse groups in a community sample in Sri Lanka. METHODS: The sample of 267 persons aged between 16 and 75 years was recruited from a semi-urban area. 219 completed a paper-based questionnaire and 48 responded to an online survey. Construct validity was tested for factorial validity (Confirmatory Factor Analysis -CFA), convergent validity and known group validity. Composite reliability for congeneric measures and test-retest reliability were also tested. Multi-group CFA (MG-CFA) was used to test measurement invariance. RESULTS: The translated Sinhala version demonstrated good content and face validity. Internal consistency reliability of the five items had a Cronbach's alpha of 0.85 and test-retest reliability over 2 weeks was satisfactory (Pearson r = 0.72, p < 0.001, ICC = 0.82). Confirmatory factor analysis supported factorial validity with a [Formula: see text] =4.99 (p = 0.28), a RMSEA of 0.03 (90% C.I. =0.00-0.10), a SRMR of 0.02, a TLI of 0.99 and a CFI of 0.99; factor loadings were between 0.55 and 0.89. Measurement invariance was acceptable for configural, metric and scalar invariance for gender. WHO-5 scores were significantly negatively correlated with the Patient Health Questionnaire (PHQ-9) (Pearson's r = - 0.45, p < 0.001) scores and the Kessler Psychological Distress Scale (K10) scores (Pearson's r = - 0.56, p < 0.001). CONCLUSION: The Sinhala translation of WHO-5 well-being index has shown acceptable psychometric properties and can be used for assessing mental well-being in the community in Sri Lanka. Further testing of the measure with larger and diverse (including different ethnic/cultural) groups are indicated to test measurement invariance of the measure.


Asunto(s)
Calidad de Vida/psicología , Encuestas y Cuestionarios/normas , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Psicometría/instrumentación , Reproducibilidad de los Resultados , Sri Lanka , Traducciones , Adulto Joven
9.
J Intellect Disabil Res ; 64(3): 251-257, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31808234

RESUMEN

BACKGROUND: Diagnosing Attention Deficit Hyperactivity Disorder (ADHD) in people with intellectual disability (ID) remains challenging. The Diagnostic and Statistical Manual of Mental Disorder V (DSM V) classification system is often used to diagnose ADHD in the general population; however, the presence of ID and other associated conditions such as autism and communication difficulties can make it difficult to apply the DSM V criteria in people with ID. Therefore, diagnosing ADHD in people with ID is often made using clinical judgement and/or the application of diagnostic criteria. There are no studies comparing the diagnostic accuracy of clinical judgement and the use of DSM V criteria in people with ID and ADHD. METHOD: The aims of the study were to compare the accuracy of the diagnosis of ADHD in people with ID according to the DSM V criteria versus clinical judgement and to determine which criteria are more reliable. A questionnaire was developed using five fictional case scenarios of people with ID. Questionnaires were presented to practising psychiatrists chosen as a convenience sample in the United Kingdom over a period of 12 months. Case scenarios were developed and agreed to be positive or negative for ADHD by the study authors prior to rating by clinicians. The clinicians were asked to read the scenarios and to make a judgement on the cases regarding the symptoms of ADHD. They were then presented with the 18 DSM V criteria of ADHD and asked to select the criteria they considered were present in each scenario. Sensitivity, specificity, likelihood ratios and predictive values for both the DSM V criteria and clinical opinions were calculated for correctly identifying the exemplar cases. RESULTS: The data showed strong sensitivity [0.82 95% confidence interval (CI) 0.74-0.89] and high specificity (1.00 95% CI 0.95-1.00) for the raters' clinical opinion. In contrast, the DSM V criteria alone, as assessed by the raters, did not reliably provide ADHD diagnoses, with a sensitivity of only 0.23 (95% CI 0.15-0.31). This difference in sensitivity between the two was statistically significant at P < 0.001. CONCLUSION: The study results suggest that clinical opinion is the 'gold standard' at present in diagnosing ADHD in adults with ID in the absence of a validated diagnostic tool in this group. Further studies are needed to understand how symptoms of ADHD can be presented differently in people with ID. DSM V criteria for ADHD may need to be adapted according to the severity of ID and other neurodevelopmental disorders.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad/diagnóstico , Razonamiento Clínico , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Discapacidad Intelectual/diagnóstico , Trastorno por Déficit de Atención con Hiperactividad/epidemiología , Comorbilidad , Humanos , Discapacidad Intelectual/epidemiología , Psiquiatría , Sensibilidad y Especificidad
10.
Parasitology ; 146(10): 1247-1255, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31084638

RESUMEN

Fasciola jacksoni is a significant contributor to the health and mortality of Asian elephants, particularly those in Sri Lanka. Despite the impact of fascioliasis on elephant populations, it is a neglected veterinary disease with limited taxonomic understanding. Molecular characterization and phylogenetic analysis of F. jacksoni were carried out to evaluate its suggested basal position in the Fasciolidae. Adult worms were collected during post-mortem of elephants, and eggs were collected from living elephants in National parks across Sri Lanka. Using the mitochondrial genes nicotinamide dehydrogenase subunit 1 (nad1) and cytochrome oxidase subunit 1 (cox1), and a partial 28S ribosomal DNA (28S rDNA), DNA sequences were generated from the F. jacksoni adult and egg material. Maximum likelihood (ML) phylogenetic analyses did not resolve F. jacksoni to be basal to the Fasciolidae. Furthermore, the ML analyses showed that the genus Fasciola was not monophyletic and that F. jacksoni was a sister species to the deer liver fluke Fascioloides magna. A clear framework is required to determine the taxonomic status of F. jacksoni and this current study provides the first detailed application of molecular techniques from multiple hosts across Sri Lanka with the production of reference DNA sequences for this important parasite.


Asunto(s)
Elefantes/parasitología , Fasciola/clasificación , Fasciola/genética , Fascioliasis/veterinaria , Filogenia , Animales , Análisis por Conglomerados , ADN de Helmintos/química , ADN de Helmintos/genética , ADN Mitocondrial/química , ADN Mitocondrial/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Complejo IV de Transporte de Electrones/genética , Fasciola/aislamiento & purificación , Fascioliasis/parasitología , NADH Deshidrogenasa/genética , ARN Ribosómico 28S/genética , Análisis de Secuencia de ADN , Sri Lanka
11.
Acta Chim Slov ; 65(1): 150-159, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29562116

RESUMEN

The present study focused on using microencapsulation technique to develop an antioxidant and antibacterial active smart cotton fabric using encapsulated lime oil (LO). LO microcapsules were prepared via the complex coacervation method using chitosan and gum arabic wall materials. UV-Visible and FTIR spectrometry verified the successful encapsulation of LO. The synthesized LO microcapsules were irregular in shape and differed in size between 15-160 µm according to the optical and SEM images. The loading of the microcapsules was found to be 2943 ± 128 µL/g with a loading efficiency of 82 ± 4%. The antioxidant activity of the LO microcapsules was 1336 ± 17 µg PGE/g (Folin-Ciocalteu assay). Brine shrimp lethality assay indicated that the cytotoxicity of LO was minimized upon microencapsulation. Succinic acid was used as the binder to incorporate the LO microcapsules on to the cotton fabric. The SEM images confirmed the steady attachment of LO microcapsules to the cotton fibres. The cotton fabric containing LO microcapsules displayed significant antibacterial activity against four bacterial species prior to and after subjecting the fabric to wash conditions.

12.
Environ Monit Assess ; 188(1): 58, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26707404

RESUMEN

The use of water quality indices (WQIs) as a tool to evaluate the status of water quality in rivers has been introduced since the 1960s. The WQI transforms selected water quality parameters into a dimensionless number so that changes in river water quality at any particular location and time could be presented in a simple and easily understandable manner. Although many WQIs have been developed, there is no worldwide accepted method for implementing the steps used for developing a WQI. Thus, there is a continuing interest to develop accurate WQIs that suit a local or regional area. This paper aimed to provide significant contribution to the development of future river WQIs through a review of 30 existing WQIs based on the four steps needed to develop a WQI. These steps are the selection of parameters, the generation of sub-indices, the generation of parameter weights and the aggregation process to compute the final index value. From the 30 reviewed WQIs, 7 were identified as most important based on their wider use and they were discussed in detail. It was observed that a major factor that influences wider use of a WQI is the support provided by the government and authorities to implement a WQI as the main tool to evaluate the status of rivers. Since there is a lot of subjectivity and uncertainty involved in the steps for developing and applying a WQI, it is recommended that the opinion of local water quality experts is taken, especially in the first three steps (through techniques like Delphi method). It was also observed that uncertainty and sensitivity analysis was rarely undertaken to reduce uncertainty, and hence such an analysis is recommended for future studies.


Asunto(s)
Ríos/química , Contaminantes del Agua/normas , Contaminación del Agua/estadística & datos numéricos , Calidad del Agua/normas , Monitoreo del Ambiente/métodos , Agua Dulce
13.
Trop Anim Health Prod ; 47(1): 159-62, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25319451

RESUMEN

The objective of this work was to evaluate the effect of two synchronization methods with prostaglandins F2α (PGF2α) on heifers and multiparous cows. Fourty-three Bos indicus cows (white and Red Fulani) were divided into four groups in a two-by-two factorial structure, parity x method of synchronization. The synchronization methods consisted of a two-dose regime which involved injection of animals on day 0 with PGF2α (Lutalyse) at 5 ml per cow intramuscularly. On day 11, the injection was repeated at the same dosage. On day 14 (72 h after the second injection), a fixed-time artificial insemination (AI) was done. On day 15 (96 h after the second injection), a second insemination was done. The one-and-a-half-dose regime consisted of an injection similar to the first treatment mentioned above on day 0. Thereafter, cows were observed for heat, and anyone showing heat was inseminated. A second dose was given on day 11 to all animals not having shown any heat. A fixed-time AI was done on days 14 and 15. Blood samples were collected on the day 0 of insemination for each cow while day 11 and day 21 after insemination. Progesterone was analysed by means of standard ELISA progesterone kits to determine its profiles after insemination. Results show no evidence of the effect of treatments on conception rates (P > 0.05). Similarly, heifers and multiparous cows had similar conception rates (P > 0.05). Between 3 weeks and 3 months of pregnancy, there was a loss of embryos of 28% in heifers and 20% in multiparous cows, but the difference between the two groups was not significant (P > 0.05). It recommended that farmers do not synchronize animals with poor body condition score (BCS). They should also monitor weight gains of heifers, remove them from the herd when they have been mixed with young growing bulls and put them in a breeding herd. The two-dose regime is better to be used in areas where the inseminator cannot easily be available.


Asunto(s)
Crianza de Animales Domésticos/métodos , Dinoprost/farmacología , Sincronización del Estro/métodos , Fertilización/efectos de los fármacos , Inseminación Artificial/veterinaria , Paridad/efectos de los fármacos , Progesterona/sangre , Animales , Cruzamiento/métodos , Camerún , Bovinos , Femenino , Masculino , Embarazo , Preñez , Factores de Tiempo
14.
Nat Chem Biol ; 8(12): 982-9, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23086298

RESUMEN

Under endoplasmic reticulum stress, unfolded protein accumulation leads to activation of the endoplasmic reticulum transmembrane kinase/endoRNase (RNase) IRE1α. IRE1α oligomerizes, autophosphorylates and initiates splicing of XBP1 mRNA, thus triggering the unfolded protein response (UPR). Here we show that IRE1α's kinase-controlled RNase can be regulated in two distinct modes with kinase inhibitors: one class of ligands occupies IRE1α's kinase ATP-binding site to activate RNase-mediated XBP1 mRNA splicing even without upstream endoplasmic reticulum stress, whereas a second class can inhibit the RNase through the same ATP-binding site, even under endoplasmic reticulum stress. Thus, alternative kinase conformations stabilized by distinct classes of ATP-competitive inhibitors can cause allosteric switching of IRE1α's RNase--either on or off. As dysregulation of the UPR has been implicated in a variety of cell degenerative and neoplastic disorders, small-molecule control over IRE1α should advance efforts to understand the UPR's role in pathophysiology and to develop drugs for endoplasmic reticulum stress-related diseases.


Asunto(s)
Endorribonucleasas/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Adaptadoras Transductoras de Señales , Catálisis , Células Cultivadas , Reactivos de Enlaces Cruzados , Proteínas de Unión al ADN/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Estrés del Retículo Endoplásmico/fisiología , Humanos , Péptidos y Proteínas de Señalización Intracelular , Isoenzimas/antagonistas & inhibidores , Isoenzimas/metabolismo , Conformación Molecular , Mutación/genética , Mutación/fisiología , Fosforilación , Empalme del ARN/efectos de los fármacos , Factores de Transcripción del Factor Regulador X , Ribonucleasas/metabolismo , Factores de Transcripción/metabolismo , Respuesta de Proteína Desplegada/efectos de los fármacos , Regulación hacia Arriba/efectos de los fármacos , Proteína 1 de Unión a la X-Box
15.
bioRxiv ; 2024 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-37461469

RESUMEN

Purpose: Metastatic castration-resistant prostate cancer remains incurable regardless of recent therapeutic advances. Prostate cancer tumors display highly glycolytic phenotypes as the cancer progresses. Non-specific inhibitors of glycolysis have not been utilized successfully for chemotherapy, because of their penchant to cause systemic toxicity. This study reports the preclinical activity, safety, and pharmacokinetics of a novel small molecule preclinical candidate, BKIDC-1553, with antiglycolytic activity. Experimental design: We tested a large battery of prostate cancer cell lines for inhibition of cell proliferation, in vitro. Cell cycle, metabolic and enzymatic assays were used to demonstrate their mechanism of action. A human PDX model implanted in mice and a human organoid were studied for sensitivity to our BKIDC preclinical candidate. A battery of pharmacokinetic experiments, absorption, distribution, metabolism, and excretion experiments, and in vitro and in vivo toxicology experiments were carried out to assess readiness for clinical trials. Results: We demonstrate a new class of small molecule inhibitors where antiglycolytic activity in prostate cancer cell lines is mediated through inhibition of hexokinase 2. These compounds display selective growth inhibition across multiple prostate cancer models. We describe a lead BKIDC-1553 that demonstrates promising activity in a preclinical xenograft model of advanced prostate cancer, equivalent to that of enzalutamide. BKIDC-1553 demonstrates safety and pharmacologic properties consistent with a compound that can be taken into human studies with expectations of a good safety margin and predicted dosing for efficacy. Conclusion: This work supports testing BKIDC-1553 and its derivatives in clinical trials for patients with advanced prostate cancer.

16.
Mol Cancer Ther ; 23(7): 973-994, 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38507737

RESUMEN

Metastatic castration-resistant prostate cancer remains incurable regardless of recent therapeutic advances. Prostate cancer tumors display highly glycolytic phenotypes as the cancer progresses. Nonspecific inhibitors of glycolysis have not been utilized successfully for chemotherapy, because of their penchant to cause systemic toxicity. This study reports the preclinical activity, safety, and pharmacokinetics of a novel small-molecule preclinical candidate, BKIDC-1553, with antiglycolytic activity. We tested a large battery of prostate cancer cell lines for inhibition of cell proliferation, in vitro. Cell-cycle, metabolic, and enzymatic assays were used to demonstrate their mechanism of action. A human patient-derived xenograft model implanted in mice and a human organoid were studied for sensitivity to our BKIDC preclinical candidate. A battery of pharmacokinetic experiments, absorption, distribution, metabolism, and excretion experiments, and in vitro and in vivo toxicology experiments were carried out to assess readiness for clinical trials. We demonstrate a new class of small-molecule inhibitors where antiglycolytic activity in prostate cancer cell lines is mediated through inhibition of hexokinase 2. These compounds display selective growth inhibition across multiple prostate cancer models. We describe a lead BKIDC-1553 that demonstrates promising activity in a preclinical xenograft model of advanced prostate cancer, equivalent to that of enzalutamide. BKIDC-1553 demonstrates safety and pharmacologic properties consistent with a compound that can be taken into human studies with expectations of a good safety margin and predicted dosing for efficacy. This work supports testing BKIDC-1553 and its derivatives in clinical trials for patients with advanced prostate cancer.


Asunto(s)
Proliferación Celular , Glucólisis , Ensayos Antitumor por Modelo de Xenoinjerto , Masculino , Humanos , Animales , Ratones , Glucólisis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Línea Celular Tumoral , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/metabolismo , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico
17.
Chembiochem ; 14(2): 209-16, 2013 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-23319368

RESUMEN

Protein kinases are essential enzymes for cellular signaling, and are often regulated by participation in protein complexes. The mitogen-activated protein kinase (MAPK) p38 is involved in multiple pathways, and its regulation depends on its interactions with other signaling proteins. However, the identification of p38-interacting proteins is challenging. For this reason, we have developed label transfer reagents (LTRs) that allow labeling of p38 signaling complexes. These LTRs leverage the potency and selectivity of known p38 inhibitors to place a photo-crosslinker and tag in the vicinity of p38 and its binding partners. Upon UV irradiation, proteins that are in close proximity to p38 are covalently crosslinked, and labeled proteins are detected and/or purified with an orthogonal chemical handle. Here we demonstrate that p38-selective LTRs selectively label a diversity of p38 binding partners, including substrates, activators, and inactivators. Furthermore, these LTRs can be used in immunoprecipitations to provide low-resolution structural information on p38-containing complexes.


Asunto(s)
Mapeo de Interacción de Proteínas/métodos , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Animales , Línea Celular , Humanos , Indicadores y Reactivos , Modelos Moleculares , Transducción de Señal , Coloración y Etiquetado , Rayos Ultravioleta , Proteínas Quinasas p38 Activadas por Mitógenos/química , Proteínas Quinasas p38 Activadas por Mitógenos/aislamiento & purificación
18.
J Environ Manage ; 128: 363-70, 2013 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-23786875

RESUMEN

There is the need to re-configure current urban water systems to achieve the objective of sustainable water sensitive cities. Stormwater represents a valuable alternative urban water source to reduce pressure on fresh water resources, and to mitigate the environmental impact of urban stormwater runoff. The selection of suitable urban stormwater harvesting sites is generally based on the judgement of water planners, who are faced with the challenge of considering multiple technical and socio-economic factors that influence the site suitability. To address this challenge, the present study developed a robust GIS based screening methodology for identifying potentially suitable stormwater harvesting sites in urban areas as a first pass for then more detailed investigation. The study initially evaluated suitability based on the match between harvestable runoff and demand through a concept of accumulated catchments. Drainage outlets of these accumulated catchments were considered as potential stormwater harvesting sites. These sites were screened and ranked under screening parameters namely demand, ratio of runoff to demand and weighted demand distance. The methodology described in this paper was successfully applied to a case study in Melbourne, Australia in collaboration with the local water utility. The methodology was found to be effective in supporting the selection of priority sites for stormwater harvesting schemes, as it provided the basis to identify, short-list and rank sites for further detailed investigation. The rapid identification of suitable sites for stormwater harvesting can assist planners in prioritising schemes in areas that will have the most impact on reducing potable water demand.


Asunto(s)
Abastecimiento de Agua , Australia , Ciudades , Toma de Decisiones , Sistemas de Información Geográfica , Lluvia , Movimientos del Agua
19.
ACS Chem Biol ; 18(2): 431-440, 2023 02 17.
Artículo en Inglés | MEDLINE | ID: mdl-36724382

RESUMEN

Cyclin-dependent kinases (CDKs) are key mediators of cell proliferation and have been a subject of oncology drug discovery efforts for over two decades. Several CDK and activator cyclin family members have been implicated in regulating the cell division cycle. While it is thought that there are canonical CDK-cyclin pairing preferences, the extent of selectivity is unclear, and increasing evidence suggests that the cell-cycle CDKs can be activated by a pool of available cyclins. The molecular details of CDK-cyclin specificity are not completely understood despite their importance for understanding cancer cell cycles and for pharmacological inhibition of cancer proliferation. We report here a biolayer interferometry assay that allows for facile quantification of CDK binding interactions with their cyclin activators. We applied this assay to measure the impact of Cdk2 inhibitors on Cyclin A (CycA) association and dissociation kinetics. We found that Type I inhibitors increase the affinity between Cdk2 and CycA by virtue of a slowed cyclin dissociation rate. In contrast, Type II inhibitors and other small-molecule Cdk2 binders have distinct effects on the CycA association and dissociation processes to decrease affinity. We propose that the differential impact of small molecules on the cyclin binding kinetics arises from the plasticity of the Cdk2 active site as the kinase transitions between active, intermediate, and inactive states.


Asunto(s)
Quinasas CDC2-CDC28 , Quinasas Ciclina-Dependientes , Quinasas Ciclina-Dependientes/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Quinasas CDC2-CDC28/metabolismo , Quinasa 2 Dependiente de la Ciclina/metabolismo , Ciclinas/metabolismo , Fosforilación , Quinasa 4 Dependiente de la Ciclina/metabolismo
20.
Mar Pollut Bull ; 194(Pt A): 115299, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37499569

RESUMEN

Microplastics (MPs) in different marine compartments are a global concern. This study investigated the abundance, distribution, and characteristics of microplastics from ten coral reef ecosystems in Sri Lanka, a non-quantified threat for some context. Microplastics were isolated and quantified in terms of abundance, shape, size, color, and polymer type with average abundances 546.7 ± 170.3 items kg-1, 9.8 ± 7.6 items m-3, and 46.3 ± 29.7 items kg-1 in corals, water, and sediments respectively. The most dominant microplastic type was blue, LDPE fibres. Acropora exhibited the highest amount. The significant differences in average microplastic abundances among corals suggest that they are capable of enriching microplastics depending on species-specific characteristics. Similar microplastic characteristics in corals and reef environment indicate that corals may have enriched microplastics from surface water and surface sediments. Microplastics being ubiquitous in selected reefs highlights the importance of coral reefs as a long-term microplastic sink in the ocean, contributing to the missing plastic phenomena.


Asunto(s)
Antozoos , Contaminantes Químicos del Agua , Animales , Arrecifes de Coral , Microplásticos , Plásticos , Ecosistema , Sri Lanka , Contaminantes Químicos del Agua/análisis , Agua , Monitoreo del Ambiente
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