RESUMEN
Small beta barrel proteins are attractive targets for computational design because of their considerable functional diversity despite their very small size (<70 amino acids). However, there are considerable challenges to designing such structures, and there has been little success thus far. Because of the small size, the hydrophobic core stabilizing the fold is necessarily very small, and the conformational strain of barrel closure can oppose folding; also intermolecular aggregation through free beta strand edges can compete with proper monomer folding. Here, we explore the de novo design of small beta barrel topologies using both Rosetta energy-based methods and deep learning approaches to design four small beta barrel folds: Src homology 3 (SH3) and oligonucleotide/oligosaccharide-binding (OB) topologies found in nature and five and six up-and-down-stranded barrels rarely if ever seen in nature. Both approaches yielded successful designs with high thermal stability and experimentally determined structures with less than 2.4 Å rmsd from the designed models. Using deep learning for backbone generation and Rosetta for sequence design yielded higher design success rates and increased structural diversity than Rosetta alone. The ability to design a large and structurally diverse set of small beta barrel proteins greatly increases the protein shape space available for designing binders to protein targets of interest.
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Aminoácidos , Proteínas , Estructura Secundaria de Proteína , Modelos Moleculares , Proteínas/química , Conformación Proteica en Lámina beta , Pliegue de ProteínaRESUMEN
Due to hormonal variations, heart failure with preserved ejection fraction (HFpEF) remains prevalent in women and affects almost half of the heart failure (HF) patients. Given the yearly death rate of 10-30% and the unavailability of medications targeting HFpEF, the need arises for a better understanding of the fundamental mechanisms of this syndrome. This comprehensive review explores sex-specific differences in traditional risk factors; female-specific factors that may impact HFpEF development and response to therapy, including variations in hormone levels that may occur pre- and post-menopausal or during pregnancy; and disparities in comorbidities, clinical presentation, and diagnostic challenges. Lastly, the review addresses prognostic outcomes, noting that women with HFpEF have a poor quality of life but a higher survival rate. It also discusses novel biomarkers and precision medicine, emphasizing their potential to improve early detection and personalized treatment.
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Insuficiencia Cardíaca , Masculino , Humanos , Femenino , Pronóstico , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/epidemiología , Insuficiencia Cardíaca/tratamiento farmacológico , Función Ventricular Izquierda/fisiología , Volumen Sistólico/fisiología , Calidad de Vida , Factores de RiesgoRESUMEN
Herbal products are preferable to synthetic medicines, and the use of traditional medicines is increasing day-by-day. The current study was designed to evaluate the potentials of bioactive compounds from Citrullus colocynthis by performing FTIR, HPLC, and GC-MS analyses, which explore the good concentration of the secondary metabolites, such as gallic acid (74.854 ppm), vanillic acid (122.616 ppm), and ferulic acid (101.045 ppm) with considerable bioactivities. Antimicrobial protein was estimated by performing SDS-PAGE, ranging from 15 to 70 kDa in all protein fractions. The current study also checked the cytotoxicity of the bioactive compounds in the active fraction of C. colocynthis, and to perform this activity, the groups of rats were arranged with 16 rats randomly divided into four groups (three experimental and one control) by administering various dosage of methanolic fractions in dose-dependent manner. Histopathology was conducted on the livers of the rats after 15 days of sacrifice under deep anesthesia. In liver cell slides examined at the maximum dose of 600 mg/kg, minimal morphological changes, such as slight ballooning, nuclear variation, vacuolar degeneration, and hydropic degeneration, were observed. Furthermore, the in silico analysis identified bioactive compounds as potential drug candidates.
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Citrullus colocynthis , Ratas , Animales , Extractos Vegetales , Medicina Tradicional , HígadoRESUMEN
The aim of this study was to develop the ranostic nanocomposite by conjugating quantum dots with functional, therapeutic and targeting moieties. The quantum dots nanoparticles were used to diagnose and deliver anti-tumor drugs in a controlled manner to cancerous cells by fusing with tumor cell surfaces. To enhance the attachment of the nano-composite to specific tumor cells without harming neighboring normal cells, folic acid was conjugated with the nano-composite as folate receptors are over expressed in different kinds of tumors. The study was conducted for one year at the University of Punjab. The quantum dots were synthesized by a hydrothermal process using cadmium acetate and sodium sulfide. The response was evaluated on breast tumor samples for binding and nano-composite delivery under a fluorescent microscope. Fourier-transform infrared analysis was performed to confirm CdS conjugation with cysteine, folic acid and curcumin. The results showed that the quantum dot conjugate provides a two-way attack on cancer cells and causes increased cellular apoptosis. Further testing on murine animal models is required to confirm the results of this research study.
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Curcumina , Neoplasias , Puntos Cuánticos , Animales , Ratones , Curcumina/farmacología , Ácido Fólico , Neoplasias/tratamiento farmacológicoRESUMEN
BACKGROUND: As the global burden of disease evolves, lower-resource countries like Nepal face a double burden of non-communicable and infectious disease. Rapid adaptation is required for Nepal's health system to provide life-long, person-centred care while simultaneously improving quality of infectious disease services. Social determinants of health be key in addressing health disparities and could direct policy decisions to promote health and manage the disease burden. Thus, we explore the association of social determinants with the double burden of disease in Nepal. METHODS: This is a retrospective, ecological, cross-sectional analysis of infectious and non-communicable disease outcome data (2017 to 2019) and data on social determinants of health (2011 to 2013) for 753 municipalities in Nepal. Multinomial logistic regression was conducted to evaluate the associations between social determinants and disease burden. RESULTS: The 'high-burden' combined double burden (non-communicable and infectious disease) outcome was associated with more accessible municipalities, (adjOR3.94[95%CI2.94-5.28]), municipalities with higher proportions of vaccine coverage (adjOR12.49[95%CI3.05-51.09]) and malnutrition (adjOR9.19E103[95%CI19.68E42-8.72E164]), lower average number of people per household (adjOR0.32[95%CI0.22-0.47]) and lower indigenous population (adjOR0.20[95%CI0.06-0.65]) compared to the 'low-burden' category on multivariable analysis. 'High-burden' of non-communicable disease was associated with more accessible municipalities (adjOR1.93[95%CI1.45-2.57]), higher female proportion within the municipality (adjOR1.69E8[95%CI3227.74-8.82E12]), nutritional deficiency (adjOR1.39E17[95%CI11799.83-1.64E30]) and malnutrition (adjOR2.17E131[95%CI4.41E79-1.07E183]) and lower proportions of population under five years (adjOR1.05E-10[95%CI9.95E-18-0.001]), indigenous population (adjOR0.32[95%CI0.11-0.91]), average people per household (adjOR0.44[95%CI0.26-0.73]) and households with no piped water (adjOR0.21[95%CI0.09-0.49]), compared to the 'low-burden' category on adjusted analysis. 'High burden' of infectious disease was also associated with more accessible municipalities (adjOR4.29[95%CI3.05-6.05]), higher proportions of population under five years (adjOR3.78E9[95%CI9418.25-1.51E15]), vaccine coverage (adjOR25.42[95%CI7.85-82.29]) and malnutrition (adjOR4.29E41[95%CI12408.29-1.48E79]) and lower proportions of households using firewood as fuel (adjOR0.39[95%CI0.20-0.79]) ('moderate-burden' category only) compared to 'low-burden'. CONCLUSIONS: While this study produced imprecise estimates and cannot be interpreted for individual risk, more accessible municipalities were consistently associated with higher disease burden than remote areas. Female sex, lower average number per household, non-indigenous population and poor nutrition were also associated with higher burden of disease and offer targets to direct interventions to reduce the burden of infectious and non-communicable disease and manage the double burden of disease in Nepal.
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Desnutrición , Enfermedades no Transmisibles , Costo de Enfermedad , Estudios Transversales , Femenino , Promoción de la Salud , Humanos , Desnutrición/epidemiología , Nepal/epidemiología , Estudios Retrospectivos , Determinantes Sociales de la SaludRESUMEN
Medicinal plants have played an essential role in the treatment of various diseases. Thymus vulgaris, a medicinal plant, has been extensively used for biological and pharmaceutical potential. The current study was performed to check the biopotential of active biological compounds. The GC-MS analysis identified 31 compounds in methanolic crude extract, among which thymol, carvacrol, p-cymene, and eugenol are the main phytoconstituents present in T. vulgaris. The HPLC analysis quantified that flavonoids and phenolic acids are present in a good concentration in the active fraction of ethyl acetate and n-butanol. FTIR confirmed the presence of functional groups such as phenols, a carboxylic group, hydroxy group, alcohols, and a benzene ring. Among both fractions, ethyl acetate showed high antioxidant activity in the DPPH (84.1 0.88) and ABTS (87.1 0.89) assays, respectively. The anti-inflammatory activity of the fractions was done in vitro and in vivo by using a carrageenan-induced paw edema assay, while the hexane-based extract showed high anti-inflammatory activity (57.1 0.54) in a dose-response manner. Furthermore, the lead compound responsible for inhibition in the denaturation of proteins is thymol, which exhibits the highest binding affinity with COX1 (-6.4 KJ/mol) and COX2 (-6.3 KJ/mol) inflammatory proteins. The hepatotoxicity analysis showed that plant-based phytoconstituents are safe to use and have no toxicity, with no necrosis, fibrosis, and vacuolar degeneration, even at a high concentration of 800 mg/kg body weight. Furthermore, the in silico analysis of HPLC phytochemical compounds against gastric cancer genes showed that chlorogenic acid exhibited anticancer activity and showed good drug-designing characteristics. Thrombolysis and hemolysis are the major concerns of individuals suffering from gastric cancer. However, the T. vulgaris fractions showed thrombolysis from 17.6 to 5.4%; similarly, hemolysis ranged from 9.73 to 7.1% at a concentration of 12 mg/mL. The phytoconstituents present in T. vulgaris have the potential for multiple pharmacological applications. This should be further investigated to isolate bioactive compounds that can be used for the treatment of different ailments.
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Plantas Medicinales , Neoplasias Gástricas , Thymus (Planta) , Humanos , Cromatografía de Gases y Espectrometría de Masas , Extractos Vegetales/química , Neoplasias Gástricas/tratamiento farmacológico , Fitoquímicos/farmacología , Plantas Medicinales/química , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Antioxidantes/farmacología , Ciclooxigenasa 2RESUMEN
Neonatal haemolytic disease in the new-born remains of prime importance for paediatricians due to high perinatal morbidity and mortality rates. The Rh antigen family comprises several different antigens, out of which, D antigen incompatibility is well known for causing severe haemolytic disease in the foetus. Although the current literature shows anomalous cases where coexisting non-D-Rh and D-Rh antigens are the causative agents, there is very little information regarding post-natal outcomes in neonates bearing two different incompatibilities simultaneously. Herein, we discuss an unusual case of anti-D as well as anti-C antibodies (non-D-Rh) in a male neonate born to a Rh-negative mother, who developed jaundice and haemolysis in post-natal life. The neonate underwent exchange transfusion and photo therapy due to raised serum bilirubin levels, supplemented with repeated blood transfusions, intravenous immunoglobulin therapy, and immunosuppressive therapy. He responded well to the management and was later discharged from the hospital. Long-term follow-up revealed no side-effects.
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Antígenos de Grupos Sanguíneos , Eritroblastosis Fetal , Embarazo , Femenino , Recién Nacido , Masculino , Humanos , Eritroblastosis Fetal/terapia , Globulina Inmune rho(D) , Transfusión SanguíneaRESUMEN
Solid pseudopapillary neoplasms are rare and represent approximately 4% of all cystic pancreatic tumours, and predominately affect females. They have an excellent prognosis, however 10-15% of the patients show metastasis at the time of surgery or recurrence of tumour during follow-up after pancreatectomy. Surgical resection is the recommended treatment. We present a rare case of a 15-year-old female, with a pseudopapillary tumour of the pancreas which was diagnosed pre-operatively.
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Carcinoma Papilar , Neoplasias Pancreáticas , Adolescente , Carcinoma Papilar/cirugía , Niño , Femenino , Humanos , Recurrencia Local de Neoplasia , Páncreas , Pancreatectomía , Neoplasias Pancreáticas/cirugíaRESUMEN
The artery of Percheron is a rare variant of the posterior cerebral circulation. It is characterised by a single arterial trunk that supplies blood to bilateral paramedian thalami and rostral midbrain. Its occlusion can have a very wide range of presentation, and initial imaging including CT of the head maybe normal. Diagnosis and eventual treatment is usually delayed. We describe the case of an elderly man who presented with loss of consciousness, aphasia, and bilateral lower limb weakness. He was diagnosed with bilateral thalamic infarction due to the occlusion of the artery of Percheron only after an MRI of the brain was performed. Despite treatment his symptoms did not resolve completely.
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Arterias , Infarto Cerebral , Anciano , Infarto Cerebral/diagnóstico por imagen , Infarto Cerebral/etiología , Humanos , Imagen por Resonancia Magnética , Masculino , Mesencéfalo , Tálamo/diagnóstico por imagenRESUMEN
BACKGROUND: The most common primary CNS tumor in children is the medulloblastoma, which generally occurs in the posterior fossa and can spread through the CNS and spinal cord. Although the recurrence of renal cell carcinoma as a secondary tumor to neuroblastoma has been reported with successful anti-neoplastic treatment, the rare occurrence of a child who initially had medulloblastoma and then developed translocation renal cell carcinoma has never been reported before. CASE PRESENTATION: We report the case of a 12-year-old boy who initially presented with complaints of vomiting and headache. An MRI head confirmed the presence of 4 × 4 × 3 cm lesion which was resected completely and histopathology report confirmed the diagnosis of medulloblastoma Grade IV. Four years later, the child came for a follow-up visit and during routine screening, a CT scan showed heterogeneous lesion arising from the lower pole calyx of right kidney. The patient was referred to pediatric surgery for right radical nephrectomy involving the right adrenal gland. The histopathology report was consistent with the diagnosis of translocation renal cell carcinoma. CONCLUSION: Central nervous system (CNS) tumors remain the leading cause of death among pediatric neoplasms. We advise genetic testing of index cases and the establishment of an international tumor registry for a challenging disease.
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Carcinoma de Células Renales , Neoplasias Cerebelosas , Neoplasias Renales , Meduloblastoma , Carcinoma de Células Renales/diagnóstico por imagen , Carcinoma de Células Renales/cirugía , Neoplasias Cerebelosas/diagnóstico por imagen , Neoplasias Cerebelosas/genética , Neoplasias Cerebelosas/cirugía , Niño , Humanos , Neoplasias Renales/diagnóstico por imagen , Neoplasias Renales/genética , Neoplasias Renales/cirugía , Masculino , Meduloblastoma/diagnóstico por imagen , Meduloblastoma/cirugía , Recurrencia Local de NeoplasiaRESUMEN
Covid-19 pandemic has significantly challenged the healthcare delivery across the world. Surgery departments across the country responded to this challenge by halting all non-emergency procedures. This delay in diagnosis and management of surgical disease could result in significant mortality and morbidity among the most vulnerable population-the children. In this manuscript, we discuss the measures adopted as well as the challenges faced by the pediatric surgery department at Aga Khan University Hospital, Karachi (AKUH), Pakistan, which is a private, not-for-profit entity and providing optimum surgical care to the patients. We also underscore the need for global strategies for tackling such crisis.
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Infecciones por Coronavirus/epidemiología , Pandemias , Neumonía Viral/epidemiología , Procedimientos Quirúrgicos Operativos/estadística & datos numéricos , Centros de Atención Terciaria/estadística & datos numéricos , COVID-19 , Niño , Comorbilidad , Humanos , Pakistán/epidemiologíaRESUMEN
Extracellular vesicles (EVs) are membranous vesicles secreted by both prokaryotic and eukaryotic cells and play a vital role in intercellular communication. EVs are classified into several subtypes based on their origin, physical characteristics, and biomolecular makeup. Exosomes, a subtype of EVs, are released by the fusion of multivesicular bodies (MVB) with the plasma membrane of the cell. Several methods have been described in literature to isolate exosomes from biofluids including blood, urine, milk, and cell culture media, among others. While differential ultracentrifugation (dUC) has been widely used to isolate exosomes, other techniques including ultrafiltration, precipitating agents such as poly-ethylene glycol (PEG), immunoaffinity capture, microfluidics, and size-exclusion chromatography (SEC) have emerged as credible alternatives with pros and cons associated with each. In this review, we provide a summary of commonly used exosomal isolation techniques with a focus on SEC as an ideal methodology. We evaluate the efficacy of SEC to isolate exosomes from an array of biological fluids, with a particular focus on its application to adipose tissue-derived exosomes. We argue that exosomes isolated via SEC are relatively pure and functional, and that this methodology is reproducible, scalable, inexpensive, and does not require specialized equipment or user expertise. However, it must be noted that while SEC is a good candidate method to isolate exosomes, direct comparative studies are required to support this conclusion.
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Cromatografía en Gel/métodos , Exosomas/química , Exosomas/metabolismo , Animales , Vesículas Extracelulares/química , Vesículas Extracelulares/metabolismo , Humanos , Ultracentrifugación/métodos , Ultrafiltración/métodosRESUMEN
Bickerstaff Brainstem Encephalitis, a rare variant of Guillain- Barre Syndrome has an estimated prevalence of eight per 100 million individuals. It presents with the classic triad of ataxia, ophthalmoplegia and altered consciousness. We report the case of a 10-year-old child who presented with low grade fever, hypersomnia and inability to walk. Central nervous system examination revealed ophthalmoplegia and multiple cranial nerve palsies. However, CSF examination showed lack of albuminocytological dissociation with no previous history of respiratory or gastrointestinal tract infection. Unavailability of Anti-GQ1b antibodies led to a diagnosis based on suggestive clinical features, abnormal MRI signals and prompt response to corticosteroid administration. Intravenous Methyl Prednisolone in a dose of 30mg/kg/day was administered for 10 days followed by oral Prednisolone 2 mg/kg/day. After complete recovery the patient was discharged, Prednisolone was tapered gradually and eventually discontinued after four months.
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Encefalitis , Oftalmopatías , Síndrome de Guillain-Barré , Ataxia , Tronco Encefálico/diagnóstico por imagen , Niño , Encefalitis/diagnóstico , Encefalitis/tratamiento farmacológico , HumanosRESUMEN
Familial Adenomatous Polyposis accounts for <1% of all the colorectal cancer cases, with progression to colorectal cancer usually at >20 years of age. Endoscopy is essential for the diagnosis with definitive treatment involving prophylactic total colectomy. With current surgical advances, this is routinely being performed with the aid of laparoscopy. Due to resource limitations and non-availability of the screening programs in the developing world, such cases remain under diagnosed. Genetic testing is necessary for prognostication of both the index case and their at-risk family members. Thus, we present a rare case of an eight-year-old female, with an early onset progression to colorectal cancer with Familial Adenomatous Polyposis. We performed a prophylactic laparoscopic total procto-colectomy with ileo-anal anastomosis, which to our knowledge is the first ever-performed procedure in Pakistan. We conclude that progression to colorectal carcinoma in familial adenomatous polyposis can present at an earlier age than that reported in the literature. Laparoscopic total colectomy has similar outcomes than open surgical methods with better cosmetic results.
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Adenocarcinoma/cirugía , Poliposis Adenomatosa del Colon/cirugía , Laparoscopía/métodos , Proctocolectomía Restauradora/métodos , Adenocarcinoma/complicaciones , Adenocarcinoma/patología , Poliposis Adenomatosa del Colon/complicaciones , Poliposis Adenomatosa del Colon/patología , Anemia/etiología , Anemia/terapia , Transfusión Sanguínea , Niño , Femenino , Hemorragia Gastrointestinal/etiología , Hemorragia Gastrointestinal/terapia , Humanos , Ileus/terapia , Escisión del Ganglio Linfático , Ganglios Linfáticos/patología , Márgenes de Escisión , Complicaciones Posoperatorias/terapiaRESUMEN
There is huge burden of paediatric surgical diseases in low and middle income countries. Issues behind such a scenario include lack of trained paediatric surgeons, higher mortality due to infections, and poor postoperative care. The possible solution is improvement in the existing structure, which is government hospitals, because they are the most prevalent form of healthcare delivery in such countries. Proper coding system, research and identification of paediatric bellwether procedures can improve the existing health system. Task shifting and sharing can help in many areas. The doctors leaving their countries for better training and employment options should be properly incentivised locally. A lot can be done in terms of providing infrastructure, finances, changing mind-sets, developing expertise, making registry and rehabilitation. By doing so, millions of paediatric mortalities can be prevented in low and middle income countries.
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Países en Desarrollo , Cirugía General , Salud Global , Accesibilidad a los Servicios de Salud , Pediatría , Calidad de la Atención de Salud , Quemaduras/cirugía , Niño , Anomalías Congénitas/cirugía , Humanos , Unidades de Cuidado Intensivo Pediátrico/provisión & distribución , Cuidados Posoperatorios/normas , Instrumentos Quirúrgicos/provisión & distribución , Traumatología , Ventiladores Mecánicos/provisión & distribución , Heridas y Lesiones/cirugíaRESUMEN
OBJECTIVE: To determine the frequency and outcome of electrolyte imbalance in seriously ill children admitted in Paediatric Intensive Care Unit (PICU) of a public sector hospital in Karachi. METHODS: All children between the ages of one month to 12 years admitted in PICU from May 2017 to October 2017 were included. Blood samples were drawn to determine the baseline sodium, potassium, calcium, magnesium and phosphorous and followed 24 hourly or earlier, if needed (Those who had imbalance at admission or on subsequent repeat labs as per protocol). RESULTS: A total of 101 children were included in the study. Electrolyte imbalance was seen in 84%. A single electrolyte imbalance was noted in 30.58%. Hypocalcemia was the most frequent abnormality noted in 57.6%. Among the total expiries during the study period 91% had electrolyte imbalance. Mortality within 48 hours and duration of stay was also increased in these patients. CONCLUSION: Electrolyte imbalance is an important prognostic indicator in critically ill patients.
RESUMEN
In view of anxiolytic, antidepressant and memory strengthen properties of Allium cepa (AC; onion) bulb in various investigations; we aimed to evaluate the useful effects of onion on single immobilization stress -induced biochemical and behavioral changes. Mice in test group were treated with AC powder (200 mg/kg/day), dissolved in water, while the control group were received drinking water for 14 days. After 14 days control and AC treated mice were further divided into unstressed and stressed groups. Animals in the stressed group were subjected to immobilization stress for 2 h. 24-h after the immobilization stress, behavioral activities were monitored. Immobilization stress-induced an anxiogenic behavior in mice subjected to elevated plus maze test (EPM) and light dark activity test (LDA). 2-h immobilization stress-induced depressive behavior in animals measured by forced swim test (FST). Administration of AC attenuated the immobilization stress-induced behavioral deficits. Highest memory performance was observed in stressed mice that were pre-treated with AC in Morris water maze (MWM). Brain lipid peroxidation, antioxidant enzymes (SOD, CAT, GPx) and acetylcholinesterase (AChE) activities were also estimated. Present study suggests a role of antioxidant enzymes in the attenuation of 2-h stress induced anxiety and depression, and enhanced cognitive function as well by AC. The findings therefore suggest that supplementation of AC may be beneficial in the treatment of anxiety, depression and enhancement of memory function.
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Ansiedad/tratamiento farmacológico , Depresión/tratamiento farmacológico , Memoria/efectos de los fármacos , Extractos Vegetales/farmacología , Animales , Ansiolíticos/farmacología , Antidepresivos/farmacología , Ansiedad/fisiopatología , Conducta Animal/efectos de los fármacos , Encéfalo/efectos de los fármacos , Encéfalo/fisiopatología , Trastorno Depresivo/tratamiento farmacológico , Peroxidación de Lípido/efectos de los fármacos , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Ratones , Cebollas , Estrés Psicológico/fisiopatologíaRESUMEN
Over last few decades, hepatitis C has emerged as a serious infection that has threatened the health and budgets of millions in the world. The objective of health professionals to treat it with recommended therapy of Alfa interferon and Ribavirin combination presents certain risks. One of the alarms is the ability of interferon to stimulate the production of autoantibodies in the body resulting in expression of autoimmune diseases in few who develop these antibodies. The case presented here is about unmasking of myasthenia gravis in a patient who received alfa interferon therapy for her chronic hepatitis C. Alfa interferon probably plays an important role in manifestation of the diseases in susceptible patients and all autoimmune diseases cannot be taken as mere side effects of the therapy. Clinicians need to be alert to pick up these diseases earlier so that the prompt management is possible.
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Antivirales/uso terapéutico , Hepatitis C Crónica/complicaciones , Hepatitis C Crónica/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Miastenia Gravis/diagnóstico , Ribavirina/uso terapéutico , Adulto , Quimioterapia Combinada , Femenino , Humanos , Miastenia Gravis/complicacionesRESUMEN
The purpose of this study was to investigate whether p53 regulates mitochondrial function via changes in mitochondrial protein import, complex IV (COX) assembly, or the expression of key proteins involved in mitochondrial dynamics and degradation. Mitochondria from p53 KO mice displayed ultra-structural alterations and were more punctate in appearance. This was accompanied by protein-specific alterations in fission, fusion, and mitophagy-related proteins. However, matrix-destined protein import into subsarcolemmal or intermyofibrillar mitochondria was unaffected in the absence of p53, despite mitochondrial subfraction-specific reductions in Tom20, Tim23, mtHsp70, and mtHsp60 in the knockout (KO) mitochondria. Complex IV activity in isolated mitochondria was also unchanged in KO mice, but two-dimensional blue native-PAGE revealed a reduction in the assembly of complex IV within the IMF fractions from KO mice in tandem with lower levels of the assembly protein Surf1. This observed defect in complex IV assembly may facilitate the previously documented impairment in mitochondrial function in p53 KO mice. We suspect that these morphological and functional impairments in mitochondria drive a decreased reliance on mitochondrial respiration as a means of energy production in skeletal muscle in the absence of p53.
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Mitocondrias Musculares/metabolismo , Dinámicas Mitocondriales , Músculo Esquelético/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Animales , Autofagia , Respiración de la Célula , Chaperonina 60/metabolismo , Complejo IV de Transporte de Electrones/metabolismo , Metabolismo Energético , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Ratones Noqueados , Mitocondrias Musculares/ultraestructura , Proteínas de Transporte de Membrana Mitocondrial , Proteínas del Complejo de Importación de Proteínas Precursoras Mitocondriales , Proteínas Mitocondriales/metabolismo , Mitofagia , Músculo Esquelético/ultraestructura , Transporte de Proteínas , Receptores de Superficie Celular/metabolismo , Transducción de Señal , Proteína p53 Supresora de Tumor/deficiencia , Proteína p53 Supresora de Tumor/genéticaRESUMEN
An acute bout of exercise activates downstream signaling cascades that ultimately result in mitochondrial biogenesis. In addition to inducing mitochondrial synthesis, exercise triggers the removal of damaged cellular material via autophagy and of dysfunctional mitochondria through mitophagy. Here, we investigated the necessity of p53 to the changes that transpire within the muscle upon an imposed metabolic and physiological challenge, such as a bout of endurance exercise. We randomly assigned wild-type (WT) and p53 knockout (KO) mice to control, acute exercise (AE; 90 min at 15 m/min), and AE + 3 h recovery (AER) groups and measured downstream alterations in markers of mitochondrial biogenesis, autophagy, and mitophagy. In the absence of p53, activation of p38 MAPK upon exercise was abolished, whereas CaMKII and AMP-activated protein kinase only displayed an attenuated enhancement in the AER group compared with WT mice. The translocation of peroxisome proliferator-activated receptor-γ coactivator-1 α to the nucleus was diminished and only observed in the AER group, and the subsequent increase in messenger RNA transcripts related to mitochondrial biogenesis with exercise and recovery was absent in the p53 KO animals. Whole-muscle autophagic and lysosomal markers did not respond to exercise, irrespective of the genotype of the exercised mice, with the exception of increased ubiquitination observed in KO mice with exercise. Markers of mitophagy were elevated in response to AE and AER conditions in both WT and p53 KO runners. The data suggest that p53 is important for the exercise-induced activation of mitochondrial synthesis and is integral in regulating autophagy during control conditions but not in response to exercise.