Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 654
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
PLoS Biol ; 20(9): e3001798, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-36103550

RESUMEN

Sensory pathways provide complex and multifaceted information to the brain. Recent advances have created new opportunities for applying our understanding of the brain to sensory prothesis development. Yet complex sensor physiology, limited numbers of electrodes, and nonspecific stimulation have proven to be a challenge for many sensory systems. In contrast, the vestibular system is uniquely suited for prosthesis development. Its peripheral anatomy allows site-specific stimulation of 3 separate sensory organs that encode distinct directions of head motion. Accordingly, here, we investigated whether implementing natural encoding strategies improves vestibular prosthesis performance. The eye movements produced by the vestibulo-ocular reflex (VOR), which plays an essential role in maintaining visual stability, were measured to quantify performance. Overall, implementing the natural tuning dynamics of vestibular afferents produced more temporally accurate VOR eye movements. Exploration of the parameter space further revealed that more dynamic tunings were not beneficial due to saturation and unnatural phase advances. Trends were comparable for stimulation encoding virtual versus physical head rotations, with gains enhanced in the latter case. Finally, using computational methods, we found that the same simple model explained the eye movements evoked by sinusoidal and transient stimulation and that a stimulation efficacy substantially less than 100% could account for our results. Taken together, our results establish that prosthesis encodings that incorporate naturalistic afferent dynamics and account for activation efficacy are well suited for restoration of gaze stability. More generally, these results emphasize the benefits of leveraging the brain's endogenous coding strategies in prosthesis development to improve functional outcomes.


Asunto(s)
Miembros Artificiales , Vestíbulo del Laberinto , Animales , Movimientos Oculares , Macaca mulatta , Reflejo Vestibuloocular/fisiología , Vestíbulo del Laberinto/fisiología
2.
Epilepsia ; 65(6): 1568-1580, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38606600

RESUMEN

OBJECTIVE: This study was undertaken to determine whether hippocampal T2 hyperintensity predicts sequelae of febrile status epilepticus, including hippocampal atrophy, sclerosis, and mesial temporal lobe epilepsy. METHODS: Acute magnetic resonance imaging (MRI) was obtained within a mean of 4.4 (SD = 5.5, median = 2.0) days after febrile status on >200 infants with follow-up MRI at approximately 1, 5, and 10 years. Hippocampal size, morphology, and T2 signal intensity were scored visually by neuroradiologists blinded to clinical details. Hippocampal volumetry provided quantitative measurement. Upon the occurrence of two or more unprovoked seizures, subjects were reassessed for epilepsy. Hippocampal volumes were normalized using total brain volumes. RESULTS: Fourteen of 22 subjects with acute hippocampal T2 hyperintensity returned for follow-up MRI, and 10 developed definite hippocampal sclerosis, which persisted through the 10-year follow-up. Hippocampi appearing normal initially remained normal on visual inspection. However, in subjects with normal-appearing hippocampi, volumetrics indicated that male, but not female, hippocampi were smaller than controls, but increasing hippocampal asymmetry was not seen following febrile status. Forty-four subjects developed epilepsy; six developed mesial temporal lobe epilepsy and, of the six, two had definite, two had equivocal, and two had no hippocampal sclerosis. Only one subject developed mesial temporal epilepsy without initial hyperintensity, and that subject had hippocampal malrotation. Ten-year cumulative incidence of all types of epilepsy, including mesial temporal epilepsy, was highest in subjects with initial T2 hyperintensity and lowest in those with normal signal and no other brain abnormalities. SIGNIFICANCE: Hippocampal T2 hyperintensity following febrile status epilepticus predicted hippocampal sclerosis and significant likelihood of mesial temporal lobe epilepsy. Normal hippocampal appearance in the acute postictal MRI was followed by maintained normal appearance, symmetric growth, and lower risk of epilepsy. Volumetric measurement detected mildly decreased hippocampal volume in males with febrile status.


Asunto(s)
Epilepsia del Lóbulo Temporal , Hipocampo , Imagen por Resonancia Magnética , Esclerosis , Convulsiones Febriles , Estado Epiléptico , Humanos , Hipocampo/patología , Hipocampo/diagnóstico por imagen , Epilepsia del Lóbulo Temporal/diagnóstico por imagen , Epilepsia del Lóbulo Temporal/patología , Masculino , Femenino , Esclerosis/patología , Estado Epiléptico/diagnóstico por imagen , Estado Epiléptico/patología , Estado Epiléptico/etiología , Convulsiones Febriles/patología , Convulsiones Febriles/diagnóstico por imagen , Lactante , Preescolar , Niño , Estudios de Seguimiento , Atrofia/patología , Esclerosis del Hipocampo
3.
Am J Otolaryngol ; 45(4): 104261, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38574513

RESUMEN

OBJECTIVE: To compare clinical outcomes in patients with and without history of tobacco use who underwent Zenker's diverticulotomy (ZD). STUDY DESIGN: Single institution retrospective review. SETTING: Tertiary care academic hospital. METHODS: A retrospective review of patients who underwent ZD via an open stapler, rigid endoscopic CO2 laser, stapler or harmonic scalpel, and flexible endoscopic technique from January 2006 to December 2020 was performed. Data were abstracted for patient demographics, diverticular features, and rates of adverse events and symptomatic recurrence. RESULTS: Out of 424 patients, 146 (34.4 %) had a history of tobacco use: 126 (29.7 %) were former smokers, and 20 (4.7 %) were active smokers. In univariable cross-sectional analyses, the likelihood of postoperative bleeding, perforation, emergency department visits, unplanned readmission, or recurrence did not demonstrate an association with tobacco use history even after adjustment for age, sex, and surgical approach. Similarly, in Cox Proportional Hazards regression, tobacco use was not associated with an increased risk of recurrence, even after correcting for age, sex, and type of surgery. The median time to recurrence observed in our cohort was 11.5 years amongst non-smokers, 8.7 years amongst former smokers, and 1.2 years amongst active smokers (p = 0.94). CONCLUSIONS: There were no significant differences in post-operative adverse events or frequency of recurrence of ZD between active, former, and non-smokers. Although underpowered and not statistically significant, median time to recurrence appears to be shorter in smokers when compared with former and non-smokers following surgery.


Asunto(s)
Recurrencia , Divertículo de Zenker , Humanos , Divertículo de Zenker/cirugía , Masculino , Femenino , Estudios Retrospectivos , Anciano , Persona de Mediana Edad , Resultado del Tratamiento , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Uso de Tabaco/efectos adversos , Estudios Transversales
4.
J Am Chem Soc ; 145(36): 19691-19706, 2023 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-37638886

RESUMEN

Chemical modifications are necessary to ensure the metabolic stability and efficacy of oligonucleotide-based therapeutics. Here, we describe analyses of the α-(l)-threofuranosyl nucleic acid (TNA) modification, which has a shorter 3'-2' internucleotide linkage than the natural DNA and RNA, in the context of small interfering RNAs (siRNAs). The TNA modification enhanced nuclease resistance more than 2'-O-methyl or 2'-fluoro ribose modifications. TNA-containing siRNAs were prepared as triantennary N-acetylgalactosamine conjugates and were tested in cultured cells and mice. With the exceptions of position 2 of the antisense strand and position 11 of the sense strand, the TNA modification did not inhibit the activity of the RNA interference machinery. In a rat toxicology study, TNA placed at position 7 of the antisense strand of the siRNA mitigated off-target effects, likely due to the decrease in the thermodynamic binding affinity relative to the 2'-O-methyl residue. Analysis of the crystal structure of an RNA octamer with a single TNA on each strand showed that the tetrose sugar adopts a C4'-exo pucker. Computational models of siRNA antisense strands containing TNA bound to Argonaute 2 suggest that TNA is well accommodated in the region kinked by the enzyme. The combined data indicate that the TNA nucleotides are promising modifications expected to increase the potency, duration of action, and safety of siRNAs.


Asunto(s)
Ácidos Nucleicos , Animales , Ratones , Ratas , ARN Interferente Pequeño , Nucleótidos , Interferencia de ARN , Acetilgalactosamina
5.
J Neurophysiol ; 129(5): 1157-1176, 2023 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-37018758

RESUMEN

The otolith end organs inform the brain about gravitational and linear accelerations, driving the otolith-ocular reflex (OOR) to stabilize the eyes during translational motion (e.g., moving forward without rotating) and head tilt with respect to gravity. We previously characterized OOR responses of normal chinchillas to whole body tilt and translation and to prosthetic electrical stimulation targeting the utricle and saccule via electrodes implanted in otherwise normal ears. Here we extend that work to examine OOR responses to tilt and translation stimuli after unilateral intratympanic gentamicin injection and to natural/mechanical and prosthetic/electrical stimulation delivered separately or in combination to animals with bilateral vestibular hypofunction after right ear intratympanic gentamicin injection followed by surgical disruption of the left labyrinth at the time of electrode implantation. Unilateral intratympanic gentamicin injection decreased natural OOR response magnitude to about half of normal, without markedly changing OOR response direction or symmetry. Subsequent surgical disruption of the contralateral labyrinth at the time of electrode implantation surgery further decreased OOR magnitude during natural stimulation, consistent with bimodal-bilateral otolith end organ hypofunction (ototoxic on the right ear, surgical on the left ear). Delivery of pulse frequency- or pulse amplitude-modulated prosthetic/electrical stimulation targeting the left utricle and saccule in phase with whole body tilt and translation motion stimuli yielded responses closer to normal than the deficient OOR responses of those same animals in response to head tilt and translation alone.NEW & NOTEWORTHY Previous studies to expand the scope of prosthetic stimulation of the otolith end organs showed that selective stimulation of the utricle and saccule is possible. This article further defines those possibilities by characterizing a diseased animal model and subsequently studying its responses to electrical stimulation alone and in combination with mechanical motion. We show that we can partially restore responses to tilt and translation in animals with unilateral gentamicin ototoxic injury and contralateral surgical disruption.


Asunto(s)
Ototoxicidad , Vestíbulo del Laberinto , Animales , Reflejo Vestibuloocular/fisiología , Membrana Otolítica/fisiología , Chinchilla , Gentamicinas
6.
Br J Haematol ; 201(1): 140-149, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36484101

RESUMEN

Autoimmune haemolytic anaemia (AIHA) is a rare clinical condition with immunoglobulin fixation on the surface of erythrocytes, with or without complement activation. The pathophysiology of AIHA is complex and multifactorial, presenting functional abnormalities of T and B lymphocytes that generate an imbalance between lymphocyte activation, immunotolerance and cytokine production that culminates in autoimmune haemolysis. In AIHA, further laboratory data are needed to predict relapse and refractoriness of therapy, and thus, prevent adverse side-effects and treatment-induced toxicity. The metabolomic profile of AIHA has not yet been described. Our group developed a cross-sectional study with follow-up to assess the metabolomic profile in these patients, as well as to compare the metabolites found depending on the activity and intensity of haemolysis. We analysed the plasma of 26 patients with primary warm AIHA compared to 150 healthy individuals by mass spectrometry. Of the 95 metabolites found in the patients with AIHA, four acylcarnitines, two phosphatidylcholines (PC), asymmetric dimethylarginine (ADMA) and three sphingomyelins were significantly increased. There was an increase in PC, spermine and spermidine in the AIHA group with haemolytic activity. The PC ae 34:3/PC ae 40:2 ratio, seen only in the 12-month relapse group, was a predictor of relapse with 81% specificity and 100% sensitivity. Increased sphingomyelin, ADMA, PC and polyamines in patients with warm AIHA can interfere in autoantigen and autoimmune recognition mechanisms in a number of ways (deficient action of regulatory T lymphocytes on erythrocyte recognition as self, negative regulation of macrophage nuclear factor kappa beta activity, perpetuation of effector T lymphocyte and antibody production against erythrocyte antigens). The presence of PC ae 34:3/PC ae 40:2 ratio as a relapse predictor can help in identifying cases that require more frequent follow-up or early second-line therapies.


Asunto(s)
Anemia Hemolítica Autoinmune , Humanos , Anemia Hemolítica Autoinmune/terapia , Hemólisis , Estudios Transversales , Eritrocitos
7.
Int J Obes (Lond) ; 47(12): 1309-1317, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37884665

RESUMEN

BACKGROUND/OBJECTIVES: When studying the effect of weight change between two time points on a health outcome using observational data, two main problems arise initially (i) 'when is time zero?' and (ii) 'which confounders should we account for?' From the baseline date or the 1st follow-up (when the weight change can be measured)? Different methods have been previously used in the literature that carry different sources of bias and hence produce different results. METHODS: We utilised the target trial emulation framework and considered weight change as a hypothetical intervention. First, we used a simplified example from a hypothetical randomised trial where no modelling is required. Then we simulated data from an observational study where modelling is needed. We demonstrate the problems of each of these methods and suggest a strategy. INTERVENTIONS: weight loss/gain vs maintenance. RESULTS: The recommended method defines time-zero at enrolment, but adjustment for confounders (or exclusion of individuals based on levels of confounders) should be performed both at enrolment and the 1st follow-up. CONCLUSIONS: The implementation of our suggested method [adjusting for (or excluding based on) confounders measured both at baseline and the 1st follow-up] can help researchers attenuate bias by avoiding some common pitfalls. Other methods that have been widely used in the past to estimate the effect of weight change on a health outcome are more biased. However, two issues remain (i) the exposure is not well-defined as there are different ways of changing weight (however we tried to reduce this problem by excluding individuals who develop a chronic disease); and (ii) immortal time bias, which may be small if the time to first follow up is short.


Asunto(s)
Evaluación de Resultado en la Atención de Salud , Aumento de Peso , Humanos , Sesgo
8.
Am J Pathol ; 192(11): 1506-1530, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35948078

RESUMEN

Idiopathic subglottic stenosis (iSGS) is a localized airway disease that almost exclusively affects females. Understanding the molecular mechanisms involved may provide insights leading to therapeutic interventions. Next-generation sequencing was performed on tissue sections from patients with iSGS (n = 22), antineutrophil cytoplasmic antibody-associated vasculitis (AAV; n = 5), and matched controls (n = 9) to explore candidate genes and mechanisms of disease. Gene expression changes were validated, and selected markers were identified by immunofluorescence staining. Epithelial-mesenchymal transition (EMT) and leukocyte extravasation pathways were the biological mechanisms most relevant to iSGS pathogenesis. Alternatively activated macrophages (M2) were abundant in the subepithelium and perisubmucosal glands of the airway in iSGS and AAV. Increased expression of the mesenchymal marker S100A4 and decreased expression of the epithelial marker epithelial cell adhesion molecule (EPCAM) further supported a role for EMT, but to different extents, in iSGS and antineutrophil cytoplasmic antibody-associated subglottic stenosis. In patients with iSGS, high expression of prostate transmembrane protein, androgen induced 1 (PMEPA1), an EMT regulator, was associated with a shorter recurrence interval (25 versus 116 months: hazard ratio = 4.16; P = 0.041; 95% CI, 1.056-15.60). Thus, EMT is a key pathogenetic mechanism of subglottic stenosis in iSGS and AAV. M2 macrophages contribute to the pathogenesis of both diseases, suggesting a shared profibrotic mechanism, and PMEPA1 may be a biomarker for predicting disease recurrence in iSGS.


Asunto(s)
Anticuerpos Anticitoplasma de Neutrófilos , Laringoestenosis , Masculino , Femenino , Humanos , Constricción Patológica , Pronóstico , Laringoestenosis/genética , Laringoestenosis/patología , Análisis de Secuencia de ARN , Proteínas de la Membrana/genética
9.
Nucleic Acids Res ; 49(18): 10250-10264, 2021 10 11.
Artículo en Inglés | MEDLINE | ID: mdl-34508350

RESUMEN

In order to achieve efficient therapeutic post-transcriptional gene-silencing mediated by the RNA interference (RNAi) pathway, small interfering RNAs (siRNAs) must be chemically modified. Several supra-RNA structures, with the potential to stabilize siRNAs metabolically have been evaluated for their ability to induce gene silencing, but all have limitations or have not been explored in therapeutically relevant contexts. Covalently closed circular RNA transcripts are prevalent in eukaryotes and have potential as biomarkers and disease targets, and circular RNA mimics are being explored for use as therapies. Here we report the synthesis and evaluation of small circular interfering RNAs (sciRNAs). To synthesize sciRNAs, a sense strand functionalized with the trivalent N-acetylgalactosamine (GalNAc) ligand and cyclized using 'click' chemistry was annealed to an antisense strand. This strategy was used for synthesis of small circles, but could also be used for synthesis of larger circular RNA mimics. We evaluated various sciRNA designs in vitro and in vivo. We observed improved metabolic stability of the sense strand upon circularization and off-target effects were eliminated. The 5'-(E)-vinylphosphonate modification of the antisense strand resulted in GalNAc-sciRNAs that are potent in vivo at therapeutically relevant doses. Physicochemical studies and NMR-based structural analysis, together with molecular modeling studies, shed light on the interactions of this novel class of siRNAs, which have a partial duplex character, with the RNAi machinery.


Asunto(s)
Silenciador del Gen , Interferencia de ARN , ARN Circular , ARN Interferente Pequeño , Animales , Femenino , Ratones , Ratones Endogámicos C57BL
10.
Am J Otolaryngol ; 44(4): 103864, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37001395

RESUMEN

OBJECTIVE: Flexible endoscopic Zenker's diverticulotomy (FEZD) is a procedure performed primarily by gastroenterologists for treatment of symptomatic Zenker's diverticulum (ZD). Given the lack of prior investigations with large sample sizes, we report on one of the largest series of patients who underwent FEZD. METHODS: A review of patients who underwent FEZD at our institution from 2006 to 2021 was performed. Data were abstracted for patient demographics, clinical features, procedural characteristics, adverse events, and outcomes. RESULTS: A total of 75 patients (37 women) with mean age of 77.9 (33-102) years and mean (range) follow-up of 1.1 (0-13.2) years were identified. 67.9 % of FEZD cases were performed under general anesthesia. The mean procedure time was 37.1 min. Same day discharge and resumption of oral intake was seen in 56.4 % and 57.1 % of cases, respectively. Adverse events included intraprocedural bleeding (15.7 %) controlled with endoscopic means, infection (4.8 %) exclusively managed with antibiotics in all but one case, subcutaneous emphysema (2.4 %), and perforation (10.7 %) conservatively managed in all but one case. 97.6 % of patients had sustained subjective improvement in symptoms following their procedure. Fifteen patients (20 %) experienced recurrence after undergoing initial FEZD-26.7 % percent of whom were sufficiently treated with repeat FEZDs. Younger age was associated with recurrence (p < 0.01). CONCLUSION: FEZD is an effective, safe procedure for the management of symptomatic ZD. It is a viable alternative for patients in whom otorhinolaryngological procedures via rigid endoscopy are not an option.


Asunto(s)
Esofagoscopía , Divertículo de Zenker , Humanos , Femenino , Anciano , Esofagoscopía/métodos , Estudios Retrospectivos , Endoscopios , Divertículo de Zenker/cirugía , Resultado del Tratamiento
11.
J Am Chem Soc ; 144(32): 14517-14534, 2022 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-35921401

RESUMEN

Although 2'-deoxy-2'-α-F-2'-ß-C-methyl (2'-F/Me) uridine nucleoside derivatives are a successful class of antiviral drugs, this modification had not been studied in oligonucleotides. Herein, we demonstrate the facile synthesis of 2'-F/Me-modified pyrimidine phosphoramidites and their subsequent incorporation into oligonucleotides. Despite the C3'-endo preorganization of the parent nucleoside, a single incorporation into RNA or DNA resulted in significant thermal destabilization of a duplex due to unfavorable enthalpy, likely resulting from steric effects. When located at the terminus of an oligonucleotide, the 2'-F/Me modification imparted more resistance to degradation than the corresponding 2'-fluoro nucleotides. Small interfering RNAs (siRNAs) modified at certain positions with 2'-F/Me had similar or better silencing activity than the parent siRNAs when delivered via a lipid nanoparticle formulation or as a triantennary N-acetylgalactosamine conjugate in cells and in mice. Modification in the seed region of the antisense strand at position 6 or 7 resulted in an activity equivalent to the parent in mice. Additionally, placement of the antisense strand at position 7 mitigated seed-based off-target effects in cell-based assays. When the 2'-F/Me modification was combined with 5'-vinyl phosphonate, both E and Z isomers had silencing activity comparable to the parent. In combination with other 2'-modifications such as 2'-O-methyl, the Z isomer is detrimental to silencing activity. Presumably, the equivalence of 5'-vinyl phosphonate isomers in the context of 2'-F/Me is driven by the steric and conformational features of the C-methyl-containing sugar ring. These data indicate that 2'-F/Me nucleotides are promising tools for nucleic acid-based therapeutic applications to increase potency, duration, and safety.


Asunto(s)
Organofosfonatos , Nucleótidos de Pirimidina , Animales , Liposomas , Ratones , Modelos Moleculares , Nanopartículas , Conformación de Ácido Nucleico , Nucleósidos , Nucleótidos , Oligonucleótidos , Fosfatos , Interferencia de ARN , ARN Interferente Pequeño/genética
12.
Mol Med ; 28(1): 44, 2022 04 25.
Artículo en Inglés | MEDLINE | ID: mdl-35468719

RESUMEN

BACKGROUND: Menopausal hormone therapy (MHT) is recommended for only five years to treat vasomotor symptoms and vulvovaginal atrophy because of safety concerns with long-term treatment. We investigated the ability of 2',3',4'-trihydroxychalcone (2',3',4'-THC) to modulate estrogen receptor (ER)-mediated responses in order to find drug candidates that could potentially prevent the adverse effects of long-term MHT treatment. METHODS: Transfection assays, real time-polymerase chain reaction, and microarrays were used to evaluate the effects of 2',3',4'-THC on gene regulation. Radioligand binding studies were used to determine if 2',3',4'-THC binds to ERα. Cell proliferation was examined in MCF-7 breast cancer cells by using growth curves and flow cytometry. Western blots were used to determine if 2',3',4'-THC alters the E2 activation of the MAPK pathway and degradation of ERα. Chromatin immunoprecipitation was used to measure ERα binding to genes. RESULTS: The 2',3',4'-THC/E2 combination produced a synergistic activation with ERα on reporter and endogenous genes in human U2OS osteosarcoma cells. Microarrays identified 824 genes that we termed reprogrammed genes because they were not regulated in U2OS-ERα cells unless they were treated with 2',3',4'-THC and E2 at the same time. 2',3',4'-THC blocked the proliferation of MCF-7 cells by preventing the E2-induced activation of MAPK and c-MYC transcription. The antiproliferative mechanism of 2',3',4'-THC differs from selective estrogen receptor modulators (SERMs) because 2',3',4'-THC did not bind to the E2 binding site in ERα like SERMs. CONCLUSION: Our study suggests that 2',3',4'-THC may represent a new class of ERα modulators that do not act as a direct agonists or antagonists. We consider 2',3',4'-THC to be a reprogramming compound, since it alters the activity of ERα on gene regulation and cell proliferation without competing with E2 for binding to ERα. The addition of a reprogramming drug to estrogens in MHT may offer a new strategy to overcome the adverse proliferative effects of estrogen in MHT by reprogramming ERα as opposed to an antagonist mechanism that involves blocking the binding of estrogen to ERα.


Asunto(s)
Neoplasias Óseas , Neoplasias de la Mama , Femenino , Humanos , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Proliferación Celular , Estradiol/metabolismo , Estradiol/farmacología , Receptor alfa de Estrógeno/agonistas , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/metabolismo , Estrógenos/farmacología , Moduladores Selectivos de los Receptores de Estrógeno/metabolismo , Moduladores Selectivos de los Receptores de Estrógeno/farmacología
13.
Histopathology ; 80(7): 1019-1025, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35040174

RESUMEN

The precursor lesion for the ~30% of colon carcinomas developing along the serrated pathway was first described in detail in 1996, and was named sessile serrated adenoma in 2003. Although the entity itself was controversial initially, over time the concept of a serrated pathway initiated by this lesion has become well accepted in the medical community. The name sessile serrated adenoma, however, has been controversial since the beginning and continues to be controversial. Alternative names, including serrated polyp with abnormal proliferation, sessile serrated polyp and, most recently, sessile serrated lesion, have been proposed. Despite the fact that the term sessile serrated lesion was adopted by the World Health Organization in 2019, none of these terms has received universal acceptance. In this article, arguments for and against adopting the term sessile serrated lesion are discussed in detail.


Asunto(s)
Adenoma , Neoplasias del Colon , Pólipos del Colon , Neoplasias Colorrectales , Adenoma/patología , Neoplasias del Colon/patología , Pólipos del Colon/patología , Neoplasias Colorrectales/patología , Humanos
14.
Chemistry ; 28(37): e202200978, 2022 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-35507693

RESUMEN

A method to rapidly diversify the molecules formed in organic crystals is introduced, with aryl nitriles playing a novel dual role as both hydrogen-bond acceptors and modifiable organic groups. The discovery of coexisting supramolecular synthons in the same crystal is also described. The general concept is demonstrated by using a bis(aryl nitrile) alkene that undergoes a hydrogen-bond-directed intermolecular [2+2] photodimerization to form a tetra(aryl nitrile)cyclobutane. The product is readily converted by click reactivity to a tetra(aryl tetrazole) and by hydrolysis to a tetra(aryl carboxylic acid). The integration of aryl nitriles into solid-state reactions opens broad avenues to post-modify products formed in crystalline solids for rapid diversification.


Asunto(s)
Ciclobutanos , Nitrilos , Ácidos Carboxílicos/química , Hidrógeno , Enlace de Hidrógeno , Nitrilos/química
15.
Chemistry ; 28(25): e202104604, 2022 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-35274391

RESUMEN

Cocrystallizations of diboronic acids [1,3-benzenediboronic acid (1,3-bdba), 1,4-benzenediboronic acid (1,4-bdba) and 4,4'-biphenyldiboronic acid (4,4'-bphdba)] and bipyridines [1,2-bis(4-pyridyl)ethylene (bpe) and 1,2-bis(4-pyridyl)ethane (bpeta)] generated the hydrogen-bonded 1 : 2 cocrystals [(1,4-bdba)(bpe)2 ] (1), [(1,4-bdba)(bpeta)2 ] (2), [(1,3-bdba)(bpe)2 (H2 O)2 ] (3) and [(1,3-bdba)(bpeta)2 (H2 O)] (4), wherein 1,3-bdba involved hydrated assemblies. The linear extended 4,4'-bphdba exhibited the formation of 1 : 1 cocrystals [(4,4'-bphdba)(bpe)] (5) and [(4,4'-bphdba-me)(bpeta)] (6). For 6, a hemiester was generated by an in-situ linker transformation. Single-crystal X-ray diffraction revealed all structures to be sustained by B(O)-H⋅⋅⋅N, B(O)-H⋅⋅⋅O, Ow -H⋅⋅⋅O, Ow -H⋅⋅⋅N, C-H⋅⋅⋅O, C-H⋅⋅⋅N, π⋅⋅⋅π, and C-H⋅⋅⋅π interactions. The cocrystals comprise 1D, 2D, and 3D hydrogen-bonded frameworks with components that display reactivities upon cocrystal formation and within the solids. In 1 and 3, the C=C bonds of the bpe molecules undergo a [2+2] photodimerization. UV radiation of each compound resulted in quantitative conversion of bpe into cyclobutane tpcb. The reactivity involving 1 occurred via 1D-to-2D single-crystal-to-single-crystal (SCSC) transformation. Our work supports the feasibility of the diboronic acids as formidable structural and reactivity building blocks for cocrystal construction.

16.
Diabetes Obes Metab ; 24(2): 204-211, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34622567

RESUMEN

AIM: To compare (in the LIRA-PRIME [NCT02730377], a randomized open-label trial), the efficacy of liraglutide in controlling glycaemia versus an oral antidiabetic drug (OAD) in patients with uncontrolled type 2 diabetes (T2D), despite metformin use in a primary care setting (n = 219 sites, n = 9 countries). MATERIALS AND METHODS: Adults (n = 1991) with T2D (HbA1c 7.5%-9.0%) receiving metformin were randomized 1:1 to liraglutide (≤1.8 mg/d) or one OAD, selected by the investigator, added to metformin, for up to 104 weeks. Primary endpoint: time to inadequate glycaemic control (HbA1c > 7.0%) at two scheduled consecutive visits after week 26. Outcomes were assessed for liraglutide versus a pooled OAD group, and (post hoc) liraglutide versus sodium-glucose co-transporter-2 inhibitors, dipeptidyl peptidase-4 inhibitors, and sulphonylureas individually. RESULTS: Among randomized patients (liraglutide, n = 996; OAD, n = 995), 47.6% were female, mean age was 57.4 years and mean HbA1c was 8.2%. Median time to inadequate glycaemic control was 44 weeks longer with liraglutide versus OAD (109 weeks [25% percentile, 38; 75% percentile, not available] vs. 65 weeks [25% percentile, 35; 75% percentile, 107], P < .0001). Changes in HbA1c and body weight at week 104 or at premature treatment discontinuation significantly favoured liraglutide over OAD. Hypoglycaemia rates were comparable between groups and few patients discontinued because of adverse events (liraglutide, 7.9% [n = 79]; OAD, 4.1% [n = 41]). Similar results were observed in the post hoc analysis for liraglutide versus individual OAD classes. CONCLUSIONS: Glycaemic control was better maintained with liraglutide versus OAD, supporting liraglutide use when intensifying therapy in primary care patients with T2D.


Asunto(s)
Diabetes Mellitus Tipo 2 , Metformina , Adulto , Glucemia , Diabetes Mellitus Tipo 2/inducido químicamente , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Quimioterapia Combinada , Femenino , Hemoglobina Glucada/análisis , Control Glucémico , Humanos , Hipoglucemiantes , Liraglutida/efectos adversos , Persona de Mediana Edad , Atención Primaria de Salud , Resultado del Tratamiento
17.
Nucleic Acids Res ; 48(8): 4028-4040, 2020 05 07.
Artículo en Inglés | MEDLINE | ID: mdl-32170309

RESUMEN

In this report, we investigated the hexopyranose chemical modification Altriol Nucleic Acid (ANA) within small interfering RNA (siRNA) duplexes that were otherwise fully modified with the 2'-deoxy-2'-fluoro and 2'-O-methyl pentofuranose chemical modifications. The siRNAs were designed to silence the transthyretin (Ttr) gene and were conjugated to a trivalent N-acetylgalactosamine (GalNAc) ligand for targeted delivery to hepatocytes. Sense and antisense strands of the parent duplex were synthesized with single ANA residues at each position on the strand, and the resulting siRNAs were evaluated for their ability to inhibit Ttr mRNA expression in vitro. Although ANA residues were detrimental at the 5' end of the antisense strand, the siRNAs with ANA at position 6 or 7 in the seed region had activity comparable to the parent. The siRNA with ANA at position 7 in the seed region was active in a mouse model. An Oligonucleotide with ANA at the 5' end was more stable in the presence of 5'-exonuclease than an oligonucleotide of the same sequence and chemical composition without the ANA modification. Modeling studies provide insight into the origins of regiospecific changes in potency of siRNAs and the increased protection against 5'-exonuclease degradation afforded by the ANA modification.


Asunto(s)
Acetilgalactosamina/química , Carbohidratos/química , Interferencia de ARN , ARN Interferente Pequeño/química , Alcoholes del Azúcar/química , Animales , Células COS , Chlorocebus aethiops , Exorribonucleasas , Hepatocitos/metabolismo , Ratones , Conformación de Ácido Nucleico , Prealbúmina/genética , Ribonucleótidos/química
18.
Am J Otolaryngol ; 43(6): 103629, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36166881

RESUMEN

OBJECTIVES: Endoscopic laser wedge excision (LWE) is an effective treatment option for idiopathic subglottic stenosis (iSGS); however, data regarding complications following LWE are limited. The aim of the following analysis was to provide a review of frequency and type of complications that occur with LWE in patients with iSGS. STUDY DESIGN: Retrospective review. METHODS: Patients with iSGS undergoing LWE between January 2002 and September 2021 were performed. Demographic data were recorded. Complications were stratified into major and minor categories. The frequency of these complications and the respective treatment for them was analyzed. RESULTS: 212 patients within the study period underwent a total of 573 LWE procedures. All but two patients were female, with a median age of 54 years at time of LWE. Of these patients, 43 (20 %) patients experienced a complication. Of these, only 7 (15 %) of the reported complications were considered major while the rest were minor in nature. Major complications included 3 cases of post-operative hemoptysis, 1 case of tracheitis, and 3 cases of reduced vocal fold hypomobility with concurrent glottic stenosis. Minor complications consisted of 2 cases of tooth fracture and 34 cases of tongue paresthesia post-operatively that was self-limited. There were no mortalities. CONCLUSION: Major complications occur in <5 % of LWE procedures based off the analysis. All major complications were managed without significant long-term morbidity. Minor complications with the LWE are self-limited in nature. Our data supports the LWE as a safe treatment option for iSGS.


Asunto(s)
Laringoestenosis , Humanos , Femenino , Persona de Mediana Edad , Masculino , Constricción Patológica , Laringoestenosis/etiología , Laringoestenosis/cirugía , Endoscopía/métodos , Glotis/cirugía , Rayos Láser
20.
Gynecol Oncol ; 163(1): 162-170, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34446269

RESUMEN

OBJECTIVE: Platinum resistance, defined as the lack of response or relapse within six months of platinum-based chemotherapy, is an important determinant of survival in gynecologic cancer. We used quantitative Mass Spectrometry to identify metabolic signatures that predict platinum resistance in patients receiving chemotherapy for gynecologic cancers. METHODS: In this study 47 patients with adenocarcinoma of the ovary or uterus who were candidates for carboplatin plus paclitaxel submitted blood for quantitation of metabolites and surgical specimens for the isolation 3-dimensional organoids used to measure individual patient platinum resistance, ex vivo. Results were correlated with response, time to progression and survival. RESULTS: Of 47 patients, 27 (64.3%) achieved complete remission with a mean time to progression of 1.9 years (± 1.5), disease-free survival of 1.7 years (± 1.4) and overall survival of 2.6 years (± 1.6) and a mean cisplatin lethal concentration 50% (LC50) = 1.15 µg/ml (range 0.4-3.1). Cisplatin LC50's correlated with a non-significant decrease in complete remission (RR [95% CI] =0.76 [0.46-1.27]), diminished disease-free survival (median: 1.15 vs. 2.99 years, p = 0.038) and with biochemical signatures of 186 metabolites. Receiver operating curves (ROC) of lipid ratios, branched chain amino acids and the tryptophan to kynurenine ratio identified patients at the highest risk of relapse and death (AUC = 0.933) with a sensitivity of 92.0% and specificity of 86.0% (p < 0.001). CONCLUSIONS: Metabolic signatures in gynecologic cancer identify patients at the highest risk of relapse and death offering new diagnostic and prognostic tools for management of the advanced gynecologic tumors.


Asunto(s)
Metabolómica/métodos , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Uterinas/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carboplatino/administración & dosificación , Cisplatino/administración & dosificación , Resistencia a Antineoplásicos , Femenino , Humanos , Persona de Mediana Edad , Neoplasias Ováricas/metabolismo , Neoplasias Ováricas/mortalidad , Paclitaxel/administración & dosificación , Neoplasias Uterinas/metabolismo , Neoplasias Uterinas/mortalidad , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA