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2.
Front Oncol ; 14: 1376652, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38606094

RESUMO

Introduction: From the advancement of treatment of pediatric cancer diagnosis, the five-year survival rate has increased significantly. However, the adverse consequence of improved survival rate is the second malignant neoplasm. Although previous studies provided information on the incidence and risk of SMN in long term survivors of childhood cancer, there is still scarce information known for short term (< 5 years) prognosis. This study aims to assess the incidence, characteristics, management, and outcome of children who develop SMN malignancies within 5 years of diagnosis of their initial cancer. Method: This is a retrospective cohort study of early Second Malignant Neoplasms (SMN) in pediatric oncology patients. The Cancer in Young People - Canada (CYP-C) national pediatric cancer registry was used and reviewed pediatric patients diagnosed with their first cancer from 2000-2015. Results: A total of 20,272 pediatric patients with a diagnosis of a first malignancy were analyzed. Of them, 0.7% were diagnosed with a SMN within the first 5 years following their first cancer diagnosis. Development of a SMN impacted survival, shown by an inferior survival rate in the SMN cohort (79.1%) after three years compared to that of the non-SMN cohort (89.7%). Several possible risk factors have been identified in the study including the use of epipodophyllotoxins, exposure to radiation, and hematopoietic stem cell 169 transplant. Discussion: This is the first national study assessing the incidence, 170 characteristics, risk factors and outcome of early SMN in Canadian children 171 from age 0-15 from 2000-2015.

3.
Analyst ; 149(9): 2573-2585, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38469706

RESUMO

Gaseous fragment ions generated in mass spectrometers may be employed as "building blocks" for the synthesis of novel molecules on surfaces using ion soft-landing. A fundamental understanding of the reactivity of the fragment ions is required to control bond formation of deposited fragments in surface layers. The fragment ion [B12X11]- (X = halogen) is formed by collision-induced dissociation (CID) from the precursor [B12X12]2- dianion. [B12X11]- is highly reactive and ion soft-landing experiments have shown that this ion binds to the alkyl chains of organic molecules on surfaces. In this work we investigate whether specific modifications of the precursor ion affect the chemical properties of the fragment ions to such an extent that attachment to functional groups of organic molecules on surfaces occurs and binding of alkyl chains is prevented. Therefore, a halogen substituent was replaced by a thiocyanate substituent. CID of the precursor [B12I11(SCN)]2- ion preferentially yields the fragment ion [B12I8S(CN)]-, which shows significantly altered reactivity compared to the fragment ions of [B12I12]2-. [B12I8S(CN)]- has a previously unknown structural element, wherein a sulfur atom bridges three boron atoms. Gas-phase reactions with different neutral reactants (cyclohexane, dimethyl sulfide, and dimethyl amine) accompanied by theoretical studies indicate that [B12I8S(CN)]- binds with higher selectivity to functional groups of organic molecules than fragment ions of [B12I12]2- (e.g., [B12I11]- and [B12I9]-). These findings were further confirmed by ion soft-landing experiments, which showed that [B12I8S(CN)]- ions attacked ester groups of adipates and phthalates, whereas [B12I11]- ions only bound to alkyl chains of the same reagents.

4.
Curr Radiopharm ; 2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-38031270

RESUMO

BACKGROUND: Ovarian disease constitutes various types of endocrine disorders, such as polycystic ovarian syndrome (PCOS), ovarian cancer, premature ovarian failure, ovarian endometriosis, and ovarian cysts. The prevalence of ovarian-related diseases is highly vulnerable in the world. The utility of various drug delivery systems for ovarian diseases has resulted in varied success. Moreover, most of them lead to severe adverse effects and are incapable of ameliorating the signs and symptoms of the condition. HYPOTHESIS: Intrauterine devices (IUDs) have positioned themselves as a mechanism to deliver the drug for various ovarian-related diseases. Thereby avoiding various stability-related issues arising due to various physiological barriers of the female reproductive tract. However, the use of intrauterine devices for drug delivery to the ovaries has not been fully explored. This is attributed to the fact that they cause cysts in the ovaries and skepticism among patients and physicians. Photo-sensitive devices are an appealing approach for managing disorders affecting the ovaries. Photo-sensitive in situ forming intrauterine implants (IUIs) have several advantages, including simplicity in application, reduced invasiveness, as well as improved site-specific drug release control. Polymeric nanoparticles (PNPs) loaded with a drug may be a suitable choice to provide sustained release, alter the pharmacokinetics, and reduce the dose and dosing frequency. CONCLUSION: The current manuscript hypothesizes the utility of a PNP-loaded biodegradable photo-responsive intrauterine implantable device as an alternate novel strategy for ameliorating ovarian-related diseases.

5.
Pharmaceuticals (Basel) ; 16(2)2023 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-37259345

RESUMO

Polycystic Ovarian Syndrome (PCOS) comprises a set of symptoms that pose significant risk factors for various diseases, including type 2 diabetes, cardiovascular disease, and cancer. Effective and safe methods to treat all the pathological symptoms of PCOS are not available. The gut microbiota has been shown to play an essential role in PCOS incidence and progression. Many dietary plants, prebiotics, and probiotics have been reported to ameliorate PCOS. Gut microbiota shows its effects in PCOS via a number of mechanistic pathways including maintenance of homeostasis, regulation of lipid and blood glucose levels. The effect of gut microbiota on PCOS has been widely reported in animal models but there are only a few reports of human studies. Increasing the diversity of gut microbiota, and up-regulating PCOS ameliorating gut microbiota are some of the ways through which prebiotics, probiotics, and polyphenols work. We present a comprehensive review on polyphenols from natural origin, probiotics, and fecal microbiota therapy that may be used to treat PCOS by modifying the gut microbiota.

6.
Drug Discov Today ; 28(5): 103571, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36990145

RESUMO

Diabetes mellitus (DM) has become one of the most prevalent diseases across the globe, mainly because of the inability of existing treatment strategies to target its root cause (i.e., pancreatic ß cell damage). Polymeric micelles (PMs) have gained attention as a treatment option for DM by targeting misfolded islet amyloid polypeptide protein (IAPP), which is common in more than 90% of DM patients. Such misfolding could result from either oxidative stress or mutation in the gene encoding IAPP. In this review, we discuss progress in the designing of PMs to halt islet amyloidosis along with their mechanism and dynamics of interactions with IAPP. We also discuss the clinical challenges associated with the translation of PMs as anti-islet amyloidogenic agents.


Assuntos
Diabetes Mellitus Tipo 2 , Ilhotas Pancreáticas , Humanos , Diabetes Mellitus Tipo 2/metabolismo , Ilhotas Pancreáticas/metabolismo , Micelas , Amiloide/genética , Polipeptídeo Amiloide das Ilhotas Pancreáticas/genética , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo
7.
Eur J Pharmacol ; 931: 175173, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-35940236

RESUMO

Advances in biotechnology have led to improving human health with number of novel approaches to mitigate life-threatening diseases such as human immunodeficiency virus (HIV) infection, cancer, and neurodegenerative diseases. In the case of HIV, the damage caused by the retrovirus to the immune system leads to opportunistic infection as well as an elevated risk of autoimmune disease and cancer. Furthermore, clinical symptoms associated with the virus itself may arise. Antiretroviral drug therapy using reverse transcriptase inhibitors, protease inhibitors, fusion inhibitor, chemokine receptor 5 antagonist and integrase strand transfer inhibitors have shown promising results in treating HIV infection and available in market in the form of various dosage forms. However, they are unable to completely cure the disease because of complexity in pathogenesis of HIV. In addition, these drugs have some limitations of poor solubility, permeability or, poor receptor binding capacity. To overcome these drawbacks, many novel drug delivery systems for the drugs belonging to above mentioned categories have been developed. The possibility of treating HIV infection using CRISPR-Cas9 gene editing has been found in 2015. This provided a new area of research to the scientists who are working towards alternative treatment strategies for HIV infections. The present article describes about various treatment strategies used to treat HIV infections with special emphasis on the role of CRISPR/Cas9 gene-based technology. The potential benefits of specific epigenetic modification in the c-c chemokine receptor 5 gene (CCR5) via various delivery methods are also highlighted.


Assuntos
Infecções por HIV , Sistemas CRISPR-Cas/genética , Edição de Genes/métodos , Terapia Genética/métodos , Infecções por HIV/tratamento farmacológico , Infecções por HIV/genética , Humanos , Receptores de Quimiocinas/genética
8.
Sci Rep ; 12(1): 13225, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35918463

RESUMO

Acute kidney injury (AKI) increases the risk of morbidity, mortality, and progression to chronic kidney disease (CKD). There are few data on the risk of CKD following community-acquired AKI (CA-AKI) and its predictors from developing countries. We evaluated the association of a panel of serum and urine biomarkers at the time of hospital discharge with 4-month renal outcome in CA-AKI. Patients of either sex, aged between 18 and 70 years, with no underlying CKD, and with CA-AKI were recruited at the time of discharge from hospital in this prospective observational study. Levels of serum and urine biomarkers were analyzed and association between these markers and development of CKD, defined as eGFR < 60 ml/min/1.73 m2 or dialysis dependence at 4 month after discharge, were analyzed using multivariate logistic regression analysis and penalized least absolute shrinkage and selection operator logistic regression. Out of a total 126 patients followed up for 4 months, 25 developed CKD. Those who developed CKD were older (p = 0.008), had higher serum creatinine (p < 0.001) and lower serum albumin (p = 0.001) at discharge. Adjusted logistic regression showed that each 10% increase in standardized serum myo-inositol oxygenase (MIOX) level increased the odds of progression to CKD by 13.5%. With 10% increase in standardized urine Neutrophil gelatinase-associated lipocalin (NGAL), serum creatinine and urine protein creatinine ratio (uPCR), increase in the odds of progression to CKD was 10.5%, 9.6% and 8%, respectively. Multivariable logistic model including serum MIOX, discharge serum creatinine and discharge uPCR, was able to predict the progression of CKD [AUC ROC 0.88; (95% CI 0.81, 0.95)]. High level serum MIOX levels at the time of discharge from hospital are associated with progression to CKD in patients with CA-AKI.


Assuntos
Injúria Renal Aguda , Insuficiência Renal Crônica , Injúria Renal Aguda/metabolismo , Adolescente , Adulto , Idoso , Biomarcadores , Creatinina , Hospitais , Humanos , Inositol Oxigenase/metabolismo , Lipocalina-2/urina , Pessoa de Meia-Idade , Alta do Paciente , Diálise Renal , Insuficiência Renal Crônica/complicações , Adulto Jovem
9.
Expert Opin Drug Deliv ; 19(7): 771-793, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35695697

RESUMO

INTRODUCTION: Diabetes mellitus (DM) is the most common metabolic disease and multifactorial, harming patients worldwide. Extensive research has been carried out in the search for novel drug delivery systems offering reliable control of glucose levels for diabetics, aiming at efficient management of DM. AREAS COVERED: Polymeric micelles (PMs) as smart drug delivery nanocarriers are discussed, focusing on oral drug delivery applications for the management of hyperglycemia. The most recent approaches used for the preparation of smart PMs employ molecular features of amphiphilic block copolymers (ABCs), such as stimulus sensitivity, ligand conjugation, and as a more specific example the ability to inhibit islet amyloidosis. EXPERT OPINION: PMs provide a unique platform for self-regulated or spatiotemporal drug delivery, mimicking the working mode of pancreatic islets to maintain glucose homeostasis for prolonged periods. This unique characteristic is achieved by tailoring the functional chemistry of ABCs considering the physicochemical traits of PMs, including sensing capabilities, hydrophobicity, etc. In addition, the application of ABCs for the inhibition of conformational changes in islet amyloid polypeptide garnered attention as one of the root causes of DM. However, research in this field is limited and further studies at the clinical level are required.


Assuntos
Diabetes Mellitus , Micelas , Diabetes Mellitus/tratamento farmacológico , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Glucose , Humanos , Polímeros/química
10.
Drug Discov Today ; 27(5): 1495-1512, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35158056

RESUMO

Polymeric micelles (PMs) have been explored pre-clinically for the delivery of chemotherapeutics to treat cancer. Their unique features, such as easy surface functionalization, stimuli-responsiveness, good stability, ability to modify drug release, enhanced permeation and retention effect, and potential to encapsulate more than one type of therapeutic molecules at a time, make them unique carriers for the targeted delivery or for enhancing the bioavailability of chemotherapeutics. PMs can also be used as theranostic nanocarriers for the mapping of drug therapy along with tumor imaging in patients with cancer. This review focuses on the limitations of existing treatment strategies and on innovative approaches employed for the functionalization of PMs for targeting cancer cells. In addition, the bottlenecks associated with the translation of PMs from the laboratory to clinics are also discussed.


Assuntos
Antineoplásicos , Neoplasias , Antineoplásicos/uso terapêutico , Portadores de Fármacos/uso terapêutico , Sistemas de Liberação de Medicamentos/métodos , Humanos , Micelas , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Polímeros/uso terapêutico
11.
Sci Transl Med ; 13(623): eabi7964, 2021 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-34878823

RESUMO

Endoreplication, duplication of the nuclear genome without cell division, occurs in disease to drive morphologic growth, cell fate, and function. Despite its criticality, the metabolic underpinnings of disease-induced endoreplication and its link to morphologic growth are unknown. Heart disease is characterized by endoreplication preceding cardiac hypertrophy. We identify ATP synthase as a central control node and determinant of cardiac endoreplication and hypertrophy by rechanneling free mitochondrial ADP to methylenetetrahydrofolate dehydrogenase 1 L (MTHFD1L), a mitochondrial localized rate-limiting enzyme of formate and de novo nucleotide biosynthesis. Concomitant activation of the adenosine monophosphate­activated protein kinase (AMPK)­retinoblastoma protein (Rb)-E2F axis co-opts metabolic products of MTHFD1L function to support DNA endoreplication and pathologic growth. Gain- and loss-of-function studies in genetic and surgical mouse heart disease models and correlation in individuals confirm direct coupling of deregulated energetics with endoreplication and pathologic overgrowth. Together, we identify cardiometabolic endoreplication as a hitherto unknown mechanism dictating pathologic growth progression in the failing myocardium.


Assuntos
Endorreduplicação , Cardiopatias , Animais , Ciclo Celular , Divisão Celular , Replicação do DNA , Camundongos
12.
CMAJ ; 193(47): E1798-E1806, 2021 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-34844937

RESUMO

BACKGROUND: The COVID-19 pandemic has had a major impact on access to health care resources. Our objective was to estimate the impact of the COVID-19 pandemic on the incidence of childhood cancer in Canada. We also aimed to compare the proportion of patients who enrolled in clinical trials at diagnosis, presented with metastatic disease or had an early death during the first 9 months of the COVID-19 pandemic compared with previous years. METHODS: We conducted an observational study that included children younger than 15 years with a new diagnosis of cancer between March 2016 and November 2020 at 1 of 17 Canadian pediatric oncology centres. Our primary outcome was the monthly age-standardized incidence rates (ASIRs) of cancers. We evaluated level and trend changes using interventional autoregressive integrated moving average models. Secondary outcomes were the proportion of patients who were enrolled in a clinical trial, who had metastatic or advanced disease and who died within 30 days. We compared the baseline and pandemic periods using rate ratios (RRs) and 95% confidence intervals (CIs). RESULTS: Age-standardized incidence rates during COVID-19 quarters were 157.7, 164.6, and 148.0 per million, respectively, whereas quarterly baseline ASIRs ranged between 150.3 and 175.1 per million (incidence RR 0.93 [95% CI 0.78 to 1.12] to incidence RR 1.04 [95% CI 0.87 to 1.24]). We found no statistically significant level or slope changes between the projected and observed ASIRs for all new cancers (parameter estimate [ß], level 4.98, 95% CI -15.1 to 25.04, p = 0.25), or when stratified by cancer type or by geographic area. Clinical trial enrolment rate was stable or increased during the pandemic compared with baseline (RR 1.22 [95% CI 0.70 to 2.13] to RR 1.71 [95% CI 1.01 to 2.89]). There was no difference in the proportion of patients with metastatic disease (RR 0.84 [95% CI 0.55 to 1.29] to RR 1.22 [0.84 to 1.79]), or who died within 30 days (RR 0.16 [95% CI 0.01 to 3.04] to RR 1.73 [95% CI 0.38 to 15.2]). INTERPRETATION: We did not observe a statistically significant change in the incidence of childhood cancer, or in the proportion of children enrolling in a clinical trial, presenting with metastatic disease or who died early during the first 9 months of the COVID-19 pandemic, which suggests that access to health care in pediatric oncology was not reduced substantially in Canada.


Assuntos
COVID-19/epidemiologia , Neoplasias/epidemiologia , Pandemias , Adolescente , Canadá/epidemiologia , Criança , Pré-Escolar , Ensaios Clínicos como Assunto/estatística & dados numéricos , Feminino , Humanos , Incidência , Lactente , Masculino , Neoplasias/mortalidade , Estudos Retrospectivos , SARS-CoV-2 , Fatores de Tempo
13.
Med Hypotheses ; 156: 110679, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34555619

RESUMO

Colon cancer is characterised by the persistent change in bowel habits due to the formation of polyps (cancerous) in the inner lining of the colon. Clinically, there are several anticancer drugs available to treat colon cancer. Oxaliplatin (third generation platinum drug) is widely prescribed anticancer drug due to its broad range anticancer properties and low toxicities over cisplatin and carboplatin. Currently, use of oxaliplatin as adjuvant chemotherapy represents a standard care for the treatment of advanced colon cancer. Despite this, its rapid degradation in systemic circulations upon administration, lack of tumor specificity, and low bioavailability limits its anticancer potential. On the other hand, vanillic acid (VA) has shown anticancer potential in colon cancer by targeting mTOR/Ras pathway, HIF-1α inhibition, NF-ĸB, and Nrf2 that regulate cell growth, cell survival, proliferation and adaptation to cancer microenvironment. Normal oral delivery of these two drugs offers non-specific drug release in gastrointestinal tract that leads to unwanted toxicity and very less amount of drug become available for colonic site. Therefore, loading of these two drugs in polysaccharide based functionalized polymeric micelles (FPMs) can offer selective targeting at colonic site and could offer better therapeutic efficacy at much lesser doses of drugs. Therefore, a new hypothesis has been proposed that the combination of vanillic acid with oxaliplatin co-loaded in FPMs could provide colon targeting ability with enhanced potency and safety profile by targeting multiple pathways than current adjuvant chemotherapies available in the market for the treatment of colon cancer.


Assuntos
Antineoplásicos , Neoplasias do Colo , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Neoplasias do Colo/tratamento farmacológico , Humanos , Micelas , Oxaliplatina/uso terapêutico , Polissacarídeos , Microambiente Tumoral , Ácido Vanílico/uso terapêutico
15.
J Control Release ; 334: 64-95, 2021 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-33887283

RESUMO

Amphiphilic block copolymers are widely utilized in the design of formulations owing to their unique physicochemical properties, flexible structures and functional chemistry. Amphiphilic polymeric micelles (APMs) formed from such copolymers have gained attention of the drug delivery scientists in past few decades for enhancing the bioavailability of lipophilic drugs, molecular targeting, sustained release, stimuli-responsive properties, enhanced therapeutic efficacy and reducing drug associated toxicity. Their properties including ease of surface modification, high surface area, small size, and enhanced permeation as well as retention (EPR) effect are mainly responsible for their utilization in the diagnosis and therapy of various diseases. However, some of the challenges associated with their use are premature drug release, low drug loading capacity, scale-up issues and their poor stability that need to be addressed for their wider clinical utility and commercialization. This review describes comprehensively their physicochemical properties, various methods of preparation, limitations followed by approaches employed for the development of optimized APMs, the impact of each preparation technique on the physicochemical properties of the resulting APMs as well as various biomedical applications of APMs. Based on the current scenario of their use in treatment and diagnosis of diseases, the directions in which future studies need to be carried out to explore their full potential are also discussed.


Assuntos
Portadores de Fármacos , Micelas , Composição de Medicamentos , Sistemas de Liberação de Medicamentos , Polímeros
16.
Assay Drug Dev Technol ; 18(6): 274-281, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32608988

RESUMO

Fisetin (FS) is a polyphenolic phytoconstituent reported to have various pharmacological activities such as antioxidant, antiparkinsonian, and antidepressant. An analytical method was developed and validated for the estimation of FS by ultrafast liquid chromatography using C-18 reverse phase column. Acetonitrile and orthophosphoric acid (0.2% v/v) in the ratio of 30:70 v/v was used as mobile phase. Flow rate was set at 1 mL/min. Chromatogram of FS was detected at wavelength of 362 nm. Retention time for FS was found to be 7.06 min. The developed method was found to be linear in the range of 2-10 µg/mL with regression coefficient of 0.9985. The method was validated as per the International Conference on Harmonization (ICH) Q2 (R1) guidelines. The percentage recovery was in the range of 95%-105%, which indicated the accuracy of the method. The percentage relative standard deviation (RSD) was found to be <2%, which indicates the precision of the method. Limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.46 and 1.41 µg/mL, respectively. The developed method was found to be robust as there was no significant change in response with change in flow rate, ratio of mobile phase, and pH. The method was successfully applied for estimation of drug loading and drug release from self-nanoemulsifying drug delivery system (SNEDDS). The % drug loading of FS in prepared liquid SNEDDS formulation was found to be 101.95%. The results of dissolution studies indicated 67.78% FS release in water at the end of 60 min.


Assuntos
Sistemas de Liberação de Medicamentos , Flavonóis/análise , Acetonitrilas/química , Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Ácidos Fosfóricos/química
17.
J Robot Surg ; 12(2): 303-310, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28730536

RESUMO

Gastric neurostimulation (GNS) with Enterra® therapy device (Medtronic, Minneapolis, MN) appears as the last resort for patients with refractory gastroparesis. Currently, the device has Humanitarian Use status by Food and Drug Administration, thereby requiring further investigation. We aim to describe its feasibility and clinical outcomes using robotic technique. From June 2014 to September 2016, 15 consecutive patients underwent robotic insertion of Enterra® device. Patient demographics, comorbidities, and clinical outcomes including mortality, length of stay, readmission rates, reoperation and complications were retrospectively collected. Patients were also assessed based on a validated 14-point questionnaire regarding satisfaction with the operation, quality of life and symptomatic relief. Mean age was 41.6 years ± 13.8 and there were 11 females (73.3%). No mortality was reported. The annual hospital admissions were reduced after GNS (2.5 ± 4.1 vs. 3.6 ± 4.4, p = 0.004). The frequency of bloating (p = 0.029) and severity of emesis (p = 0.038), early satiety (p = 0.042) and bloating (p = 0.031) were reduced after GNS. The severity and frequency total scores were also improved after GNS (12.6 ± 1.4 vs. 18.1 ± 2.7, p = 0.008 and 12.9 ± 2.2 vs. 16.1 ± 1.1, p = 0.016, respectively). This is the first report describing the clinical experience with robotic insertion of GNS device. This approach is safe and feasible and seems to have similar long-term outcomes as laparoscopic technique. Potential advantages to robotic technique include enhanced dexterity and suturing of the device within gastric wall. Further experience with large prospective studies and randomized clinical trials may be warranted.


Assuntos
Gastroparesia/cirurgia , Neuroestimuladores Implantáveis , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Procedimentos Cirúrgicos Robóticos/instrumentação , Adulto , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Náusea , Complicações Pós-Operatórias , Estudos Retrospectivos , Resultado do Tratamento , Vômito
18.
Surgery ; 158(4): 981-6; discussion 986-7, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26189069

RESUMO

PURPOSE: MicroRNA (miR)-26a has been identified as a tumor suppressor in pancreatic cancer cells. Although wild-type p53 controls cell-cycle progression, its mutant form normally present in pancreatic cancer loses this capability. Phosphorylation is known to restore wild-type activity to mutant p53. We, therefore, examined whether miR-26a treatment can restore wild-type functions of mutant p53 via phosphorylation, resulting in inhibition of cell growth. METHODS: The human pancreatic cancer cell line BxPc-3 harboring mutant p53 was used for colony formation, cell-cycle, and Western blotting assays. Gene profile analysis was conducted after transfection with pre-miR-26a. RESULTS: miR-26a expression significantly decreased cell proliferation by 80% along with marked inhibition of colony formation and cell migration. Cell-cycle inhibition at the G0/G1 interface was observed along with enhanced drug retention and increased chemosensitivity to gemcitabine. Mutant p53 was phosphorylated rapidly at its Ser9 and Ser392 residues, but not at Ser15 or Ser20. Gene profile analysis of pre-miR-26a-transfected cells showed a significant increase in gene transcripts promoting apoptosis and p53 activation, with decreased levels of genes involved in cell-cycle progression. CONCLUSION: Delivery of miR-26a may represent a novel strategy for inhibiting pancreatic cancer growth, at least in part by enhancing phosphorylation of mutant p53 to restore its wild-type functions.


Assuntos
Biomarcadores Tumorais/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Proliferação de Células/fisiologia , MicroRNAs/metabolismo , Neoplasias Pancreáticas/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Western Blotting , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Ciclo Celular/fisiologia , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Regulação Neoplásica da Expressão Gênica , Humanos , Mutação , Células-Tronco Neoplásicas , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Fosforilação , Transfecção , Proteína Supressora de Tumor p53/genética
19.
Indian J Clin Biochem ; 24(2): 208-10, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23105836

RESUMO

Hypomagnesaemia is common finding in current medical practice mainly in critically ill, post-operative patients and patients admitted to ICU in tertiary cancer cases. Magnesium has been directly implicated in hypokalemia, hypocalcaemia and dysrrthymias. We report a case of 60 year old patient, suffering from rectal carcinoma for a period of one year with confirmed hypokalemia, hypocalcaemia and hyponatremia. Magnesium supplementation corrected the underlying multiple electrolyte disturbances in the patient thus, establishing a positive correlation of magnesium with sodium, potassium and calcium.

20.
Adv Enzyme Regul ; 45: 112-25, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16054677

RESUMO

Mammalian ribonucleotide reductase (mRR) is a chemotherapeutic target. In common with other class Ia RRs, the enzyme is composed of two subunits (mR1 and mR2), with mR1 containing both the active site and allosteric effector sites and mR2 containing a stable tyrosyl radical that is essential for enzymatic activity. mRR is inhibited by Ac-FTLDADF (denoted P7), corresponding to the C-terminus of mR2, which competes with mR2 for binding to mR1. The enzyme has two physiologically important active forms, mR12mR22 and mR16(mR22)j (j=1-3), with high ATP concentrations favoring the latter. Here, we report on our progress in using structural and functional studies in conjunction with library screening to identify derivatives of tri-, tetra- and hexapeptides, and cyclic heptapeptides, having equal or significantly higher activities than P7 toward inhibition of one or both active forms. These identifications were made by screening candidate peptides both for their abilities to bind to mR1 competitively with P7 and to inhibit ribonucleotide reductase activity. A significant feature of both P7 and the newly identified derivatives is that they are stronger inhibitors of mR12mR22 than of mR16(mR22)j. For the tetrapeptides, this is due in part to their preferential binding to mR1 monomer. The possible application of these peptide derivatives in cancer chemotherapy, exploiting their preferential inhibition of mR12mR22, is considered.


Assuntos
Oligopeptídeos/farmacologia , Fragmentos de Peptídeos/farmacologia , Ribonucleotídeo Redutases/antagonistas & inibidores , Regulação Alostérica/fisiologia , Animais , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Camundongos , Modelos Moleculares , Oligopeptídeos/isolamento & purificação , Biblioteca de Peptídeos , Ribonucleotídeo Redutases/farmacologia
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