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1.
J Appl Phycol ; 36(2): 697-711, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38765689

RESUMEN

Ulvan is a green macroalgal cell wall polysaccharide that has tremendous potential for valorisation due to its unique composition of sulphated rhamnose, glucuronic acid, iduronic acid and xylose. Several potential applications such as production of biofuels, bioplastics and other value-added products necessitate the breakdown of the polysaccharide to oligomers or monomers. Research on ulvan saccharifying enzymes has been continually increasing over the last decade, with the increasing focus on valorisation of seaweed biomass for a biobased economy. Lyases are the first of several enzymes that are involved in saccharifying the polysaccharide and several ulvan lyases have been structurally and biochemically characterised to enable their effective use in the valorisation processes. This study investigates the whole genome of Vibrio sp. FNV38, an ulvan metabolising organism and biochemical characteristics of a PL24 ulvan lyase that it possesses. The genome of Vibrio sp. FNV38 has a diverse CAZy profile with several genes involved in the metabolism of ulvan, cellulose, agar, and alginate. The enzyme exhibits optimal activity at pH 8.5 in 100 mM Tris-HCl buffer and 30 °C. However, its thermal stability is poor with significant loss of activity after 2 h of incubation at temperatures above 25 °C. Breakdown product analysis reveals that the enzyme depolymerised the polysaccharide predominantly to disaccharides and tetrasaccharides. Supplementary Information: The online version contains supplementary material available at 10.1007/s10811-023-03136-3.

2.
Front Mol Biosci ; 11: 1327963, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38665936

RESUMEN

The heterodimeric kinesin-2 motor (KIF3A/KIF3B with accessory protein KAP3) drives intraflagellar transport, essential for ciliogenesis and ciliary function. Three point mutations in the KIF3B subunit have recently been linked to disease in humans (E250Q and L523P) and Bengal cats (A334T) (Cogné et al., Am. J. Hum. Genet., 2020, 106, 893-904). Patients display retinal atrophy and, in some cases, other ciliopathy phenotypes. However, the molecular mechanism leading to disease is currently unknown. Here, we used Kif3a -/- ;Kif3b -/- (knockout) 3T3 cells, which cannot make cilia, to characterize these mutations. While reexpression of KIF3B(E250Q) and KIF3B(L523P) did not rescue ciliogenesis, reexpression of wildtype or KIF3B(A334T) restored ciliogenesis to wildtype levels. Fluorescent tagging revealed that the E250Q mutant decorated microtubules and thus is a rigor mutation. The L523P mutation, in the alpha-helical stalk domain, surprisingly did not affect formation of the KIF3A/KIF3B/KAP3 complex but instead impaired motility along microtubules. Lastly, expression of the A334T motor was reduced in comparison to all other motors, and this motor displayed an impaired ability to disperse the Golgi complex when artificially linked to this high-load cargo. In summary, this work uses cell-based assays to elucidate the molecular effects of disease-causing mutations in the KIF3B subunit on the kinesin-2 holoenzyme.

3.
Eur Heart J ; 45(18): 1647-1658, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38513060

RESUMEN

BACKGROUND AND AIMS: Contrast-induced nephropathy (CIN), also known as contrast-associated acute kidney injury (CA-AKI) underlies a significant proportion of the morbidity and mortality following coronary angiographic procedures in high-risk patients and remains a significant unmet need. In pre-clinical studies inorganic nitrate, which is chemically reduced in vivo to nitric oxide, is renoprotective but this observation is yet to be translated clinically. In this study, the efficacy of inorganic nitrate in the prevention of CIN in high-risk patients presenting with acute coronary syndromes (ACS) is reported. METHODS: NITRATE-CIN is a double-blind, randomized, single-centre, placebo-controlled trial assessing efficacy of inorganic nitrate in CIN prevention in at-risk patients presenting with ACS. Patients were randomized 1:1 to once daily potassium nitrate (12 mmol) or placebo (potassium chloride) capsules for 5 days. The primary endpoint was CIN (KDIGO criteria). Secondary outcomes included kidney function [estimated glomerular filtration rate (eGFR)] at 3 months, rates of procedural myocardial infarction, and major adverse cardiac events (MACE) at 12 months. This study is registered with ClinicalTrials.gov: NCT03627130. RESULTS: Over 3 years, 640 patients were randomized with a median follow-up of 1.0 years, 319 received inorganic nitrate with 321 received placebo. The mean age of trial participants was 71.0 years, with 73.3% male and 75.2% Caucasian; 45.9% had diabetes, 56.0% had chronic kidney disease (eGFR <60 mL/min) and the mean Mehran score of the population was 10. Inorganic nitrate treatment significantly reduced CIN rates (9.1%) vs. placebo (30.5%, P < .001). This difference persisted after adjustment for baseline creatinine and diabetes status (odds ratio 0.21, 95% confidence interval 0.13-0.34). Secondary outcomes were improved with inorganic nitrate, with lower rates of procedural myocardial infarction (2.7% vs. 12.5%, P = .003), improved 3-month renal function (between-group change in eGFR 5.17, 95% CI 2.94-7.39) and reduced 1-year MACE (9.1% vs. 18.1%, P = .001) vs. placebo. CONCLUSIONS: In patients at risk of renal injury undergoing coronary angiography for ACS, a short (5 day) course of once-daily inorganic nitrate reduced CIN, improved kidney outcomes at 3 months, and MACE events at 1 year compared to placebo.


Asunto(s)
Síndrome Coronario Agudo , Lesión Renal Aguda , Medios de Contraste , Angiografía Coronaria , Nitratos , Humanos , Angiografía Coronaria/efectos adversos , Angiografía Coronaria/métodos , Medios de Contraste/efectos adversos , Masculino , Femenino , Método Doble Ciego , Nitratos/administración & dosificación , Nitratos/uso terapéutico , Lesión Renal Aguda/inducido químicamente , Lesión Renal Aguda/prevención & control , Anciano , Persona de Mediana Edad , Tasa de Filtración Glomerular/efectos de los fármacos , Compuestos de Potasio/administración & dosificación , Compuestos de Potasio/uso terapéutico
4.
iScience ; 27(3): 109149, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38405607

RESUMEN

Primary cilia are essential signaling organelles that protrude from most cells in the body. Heterodimeric kinesin-2 (KIF3A/KIF3B/KAP3) powers several intracellular transport processes, including intraflagellar transport (IFT), essential for ciliogenesis. A long-standing question is how a motor protein is differentially regulated for specific cargos. Since phosphorylation of the KIF3A tail domain was suggested to regulate the activity of kinesin-2 for ciliogenesis, similarly as for the cytosolic cargo N-Cadherin, we set out to map the phosphosites involved in this regulation. Using well-characterized Kif3a-/-; Kif3b-/- mouse embryonic fibroblasts, we performed ciliogenesis rescue assays with a library of phosphomimetic mutants comprising all predicted phosphosites in the KIF3A tail domain. In contrast to previous reports, we found that KIF3A tail domain phosphorylation is dispensable for ciliogenesis in mammals. Thus, mammalian kinesin-2 is differently regulated for IFT than currently thought, consistent with the idea of differential regulation for ciliary and cytosolic cargo.

5.
Exp Physiol ; 2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-38180298

RESUMEN

Space exploration involves many dangers including galactic cosmic radiation (GCR). This class of radiation includes high-energy protons and heavy ionizing ions. NASA has defined GCR as a carcinogenic risk for long-duration space missions. To date, no clear strategy has been developed to counter chronic GCR exposure. We hypothesize that preconditioning cells with low levels of radiation will be protective from subsequent higher radiation exposures. H9C2 cells were pretreated with 0.1 to 1.0 Gy X-rays. The challenge radiation exposure consisted of either 8 Gy X-rays or 75 cGy of GCR, using a five-ion GCRsim protocol. A cell doubling time assay was used to determine cell viability. An 8 Gy X-ray challenge alone significantly (P < 0.05) increased cell doubling time compared to the no-radiation control group. Low-dose radiation pre-treatment ameliorated the 8 Gy X-ray-induced increases in cell doubling time. A 75 cGy GCR challenge alone significantly increased cell doubling time compared to the no-radiation group. Following the 75 cGy challenge, only the 0.5 and 1.0 Gy pre-treatment ameliorated the 75 cGy-induced increases in cell doubling time. DNA damage or pathological oxidant stress will delay replicative functions and increase cell doubling time. Our results suggested that pretreatment with low-dose X-rays induced an adaptive response which offered a small but significant protection against a following higher radiation challenge. Although perhaps not a practical countermeasure, these findings may serve to offer insight into cell signalling pathways activated in response to low-dose irradiation and targeted for countermeasure development.

6.
Nat Chem Biol ; 20(1): 120-128, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38062262

RESUMEN

Macrocyclic peptides represent promising scaffolds for chemical tools and potential therapeutics. Synthetic methods for peptide macrocyclization are often hampered by C-terminal epimerization and oligomerization, leading to difficult scalability. While chemical strategies to circumvent this issue exist, they often require specific amino acids to be present in the peptide sequence. Herein, we report the characterization of Ulm16, a peptide cyclase belonging to the penicillin-binding protein-type class of thioesterases that catalyze head-to-tail macrolactamization of nonribosmal peptides. Ulm16 efficiently cyclizes various nonnative peptides ranging from 4 to 6 amino acids with catalytic efficiencies of up to 3 × 106 M-1 s-1. Unlike many previously described homologs, Ulm16 tolerates a variety of C- and N-terminal amino acids. The crystal structure of Ulm16, along with modeling of its substrates and site-directed mutagenesis, allows for rationalization of this wide substrate scope. Overall, Ulm16 represents a promising tool for the biocatalytic production of macrocyclic peptides.


Asunto(s)
Aminoácidos , Péptidos , Proteínas de Unión a las Penicilinas/metabolismo , Ciclización , Péptidos/química , Biocatálisis , Aminoácidos/metabolismo , Péptidos Cíclicos
8.
JAMA Netw Open ; 6(8): e2328810, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37578793

RESUMEN

Importance: Pharmacy deserts have increased, potentially affecting patient access and care. Historically, telepharmacies have been used to reduce pharmacy deserts to restore access, but states frequently restrict their operation. Objective: To analyze whether telepharmacy policy is associated with pharmacy deserts and access to pharmacy services. Design, Setting, and Participants: This cohort study analyzed pharmacy location and census data from 2016 through 2019 for US states with new telepharmacy policies. Nearby control states were used for comparison in a pretest-posttest nonequivalent group design. Statistical analysis was performed from January 2022 to July 2023. Exposure: Intervention states were selected if a change in telepharmacy policy was adopted in 2017 or 2018. Main Outcomes and Measures: Pharmacy deserts were defined as any geographic area located at least 10 miles from the nearest pharmacy. Primary outcomes included the change in number of telepharmacies, pharmacy deserts, and population in pharmacy deserts. Secondary outcomes included the percentage of telepharmacies located in medically underserved areas or populations (MUA/Ps), and the association between a telepharmacy opening nearby and the transition of a pharmacy desert into a nonpharmacy desert. Results: Twelve US states were included in the study (8 intervention states, 4 control states). Intervention states experienced an increase in the mean number of telepharmacies to 7.25 with a range of 4 (Arizona, Indiana) to 14 (Iowa), but control states remained at a mean of 0.25 telepharmacies with a range of 0 to 1 (Kansas). Compared with controls, intervention states experienced a 4.5% (95% CI, 1.6% to 7.4%) decrease in the percentage of places defined as pharmacy deserts (P = .001) and an 11.1% (95% CI, 2.4% to 22.6%) decrease in the population in a pharmacy desert (P = .03). Telepharmacies were more likely to be located in a MUA/P than traditional pharmacies (preperiod in MUA/P: 63.2% of telepharmacies [12 of 19] vs 33.9% of traditional pharmacies [5984 of 17 511]; P = .01; postperiod in MUA/P: 62.7% of telepharmacies [37 of 59] vs 33.7% of traditional pharmacies [5998 of 17 800]; P < .001). When a telepharmacy was established in pharmacy deserts, 37.5% (30 of 80) no longer met the study's definition of a pharmacy desert the following year. In contrast, only 1.8% of places (68 of 3892) where a nearby telepharmacy did not open experienced this change (χ21=416.4; P < .001). Conclusions and Relevance: In this cohort study, intervention states experienced a reduced population in pharmacy deserts, suggesting an association with new telepharmacy openings. States aiming to improve pharmacy access might consider less restrictive telepharmacy policies to potentially elicit greater patient outcomes.


Asunto(s)
Servicios Farmacéuticos , Farmacias , Farmacia , Humanos , Estudios de Cohortes , Área sin Atención Médica
9.
J Palliat Med ; 26(9): 1297-1301, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37192484

RESUMEN

Background: Oral medications, intravenous medications, and invasive interventions are effective means of neuropathic pain control. In patients with pain refractory to more conventional approaches, cingulum bundle ablation is an alternative treatment modality not routinely considered by providers. Case Description: A 42-year-old woman with history of cervical cancer in remission presented with intractable left lower extremity pain. Workup revealed radiation-induced left iliopsoas osteosarcoma complicated by deep venous occlusion and thrombosis. Her pain remained intractable to pharmacologic therapies and more invasive pain control interventions. A multidisciplinary decision was made to pursue bilateral subcortical cingulum bundle radiofrequency ablation. After a technically successful surgery, the patient exhibited improved pain control as evidenced by a decline in her numerical rating scale of pain and analgesic medication requirements. Conclusion: Cancer-related neuropathic pain often requires treatment with multiple modalities involving multidisciplinary teams. In select refractory cases, cingulum bundle ablation may be an effective alternative treatment modality.


Asunto(s)
Dolor en Cáncer , Neoplasias , Neuralgia , Dolor Intratable , Humanos , Adulto , Femenino , Manejo del Dolor , Dolor Intratable/etiología , Resultado del Tratamiento , Neoplasias/complicaciones
10.
Hand (N Y) ; : 15589447231153233, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36859808

RESUMEN

BACKGROUND: Unconscious bias of the clinician favors the diagnosis of carpal tunnel syndrome (CTS) in patients with median paresthesia. We hypothesized that more patients in this cohort would be diagnosed with proximal median nerve entrapment (PMNE) by strengthening our cognitive awareness of this alternative diagnosis. We also hypothesized that patients with PMNE may be successfully treated with surgical release of the lacertus fibrosus (LF). METHODS: In this retrospective study, cases of median nerve decompression at the carpal tunnel and in the proximal forearm for the 2-year periods before and after adopting strategies to mitigate cognitive bias for CTS were enumerated. Patients diagnosed with PMNE and treated by LF release under local anesthesia were evaluated to determine surgical outcome at minimum 2-year follow-up. Primary outcome measures were changes in preoperative median paresthesia and proximal median-innervated muscle strength. RESULTS: There was a statistically significant increase in PMNE cases identified after our heightened surveillance was initiated (z = 3.433, P < .001). In 10 of 12 cases, the patient had previous ipsilateral open carpal tunnel release (CTR) but experienced recurrent median paresthesia. In 8 cases evaluated an average of 5 years after LF release, there was improvement in median paresthesia and resolution of median-innervated muscle weakness. CONCLUSIONS: Owing to cognitive bias, some patients with PMNE may be misdiagnosed with CTS. All patients with median paresthesia, particularly those with persistent or recurrent symptoms after CTR, should be assessed for PMNE. Surgical release limited to the LF may be an effective treatment for PMNE.

12.
Neurosci Biobehav Rev ; 147: 105079, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36764637

RESUMEN

Child maltreatment (CM) encompasses sexual abuse, physical abuse, emotional abuse, neglect, and exposure to domestic and family violence. Epigenetic research investigating CM has focused on differential DNA methylation (DNAm) in genes associated with the stress response, but there has been limited evaluation of the specific effects of subtypes of CM. This systematic review of literature investigating DNAm associated with CM in non-clinical populations aimed to summarise the approaches currently used in research, how the type of maltreatment and age of exposure were encoded via methylation, and which genes have consistently been associated with CM. A total of fifty-four papers were eligible for review, including forty-one candidate gene studies, eight epigenome-wide association studies, and five studies with a mixed design. The ways in which the various forms of CM were conceptualised and measured varied between papers. Future studies would benefit from assessments that employ conceptually robust definitions of CM, and that capture important contextual information such as age of exposure and subtype of CM.


Asunto(s)
Maltrato a los Niños , Metilación de ADN , Niño , Humanos , Maltrato a los Niños/psicología
13.
PLoS One ; 18(2): e0279442, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36763672

RESUMEN

BACKGROUND: There is a dearth of evidence on the relationship between COVID-19 and metabolic conditions among the general U.S. population. We examined the prevalence and association of metabolic conditions with health and sociodemographic factors before and during the COVID-19 pandemic. METHODS: Data were drawn from the 2019 (N = 5,359) and 2020 (N = 3,830) Health Information National Trends Surveys on adults to compare observations before (2019) and during (2020) the COVID-19 pandemic. We conducted weighted descriptive and multivariable logistic regression analyses to assess the study objective. RESULTS: During the pandemic, compared to pre-pandemic, the prevalence of diabetes (18.10% vs. 17.28%) has increased, while the prevalence of hypertension (36.38% vs. 36.36%) and obesity (34.68% vs. 34.18%) has remained similar. In general, the prevalence of metabolic conditions was higher during the pandemic (56.09%) compared to pre-pandemic (54.96%). Compared to never smokers, former smokers had higher odds of metabolic conditions (AOR = 1.38, 95% CI = 1.01, 1.87 and AOR = 1.57, 95% CI = 1.10, 2.25) before and during the pandemic, respectively. People with mild anxiety/depression symptoms (before: AOR = 1.52, 95% CI = 1.06, 2.19 and during: AOR = 1.55, 95% CI = 1.01, 2.38) had higher odds of metabolic conditions relative to those with no anxiety/depression symptoms. CONCLUSION: This study found increased odds of metabolic conditions among certain subgroups of US adults during the pandemic. We recommend further studies and proper allocation of public health resources to address these conditions.


Asunto(s)
COVID-19 , Adulto , Humanos , COVID-19/epidemiología , Pandemias , Prevalencia , Factores Sociodemográficos , Depresión/epidemiología
14.
Elife ; 122023 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-36803359

RESUMEN

An in vitro model of human ovarian follicles would greatly benefit the study of female reproduction. Ovarian development requires the combination of germ cells and several types of somatic cells. Among these, granulosa cells play a key role in follicle formation and support for oogenesis. Whereas efficient protocols exist for generating human primordial germ cell-like cells (hPGCLCs) from human induced pluripotent stem cells (hiPSCs), a method of generating granulosa cells has been elusive. Here, we report that simultaneous overexpression of two transcription factors (TFs) can direct the differentiation of hiPSCs to granulosa-like cells. We elucidate the regulatory effects of several granulosa-related TFs and establish that overexpression of NR5A1 and either RUNX1 or RUNX2 is sufficient to generate granulosa-like cells. Our granulosa-like cells have transcriptomes similar to human fetal ovarian cells and recapitulate key ovarian phenotypes including follicle formation and steroidogenesis. When aggregated with hPGCLCs, our cells form ovary-like organoids (ovaroids) and support hPGCLC development from the premigratory to the gonadal stage as measured by induction of DAZL expression. This model system will provide unique opportunities for studying human ovarian biology and may enable the development of therapies for female reproductive health.


Ovaries are responsible for forming the eggs humans and other mammals need to reproduce. Once mature, the egg cell is released into the fallopian tube where it can be potentially fertilized by a sperm. Despite their crucial role, how eggs are made in the ovary is poorly understood. This is because ovaries are hard to access, making it difficult to conduct experiments on them. To overcome this, researchers have built artificial ovaries in the laboratory using stem cells from the embryos of mice which can develop into all cell types in the adult body. By culturing these embryonic stem cells under special conditions, researchers can convert them in to the two main cell types of the developing ovary: germ cells which go on to form eggs, and granulosa cells which help eggs grow and mature. The resulting lab-grown ovary can make eggs that produce live mice when fertilized. This approach has also been applied to human induced pluripotent stem cells (iPSCs), adult human cells which have been reprogrammed to a stem-like state. While this has produced human germ cells, generating human granulosa cells has been more challenging. Here, Pierson Smela, Kramme et al. show that activating a specific set of transcription factors (proteins that switch genes on or off) in iPSCs can make them transition to granulosa cells. First, the team tested random combinations of 35 transcription factors which, based on previous literature and genetic data, were likely to play a role in the formation of granulosa cells. This led to the identification of a small number of factors that caused the human iPSCs to develop features and carry out roles seen in mature granulosa cells; this includes producing an important reproductive hormone and supporting the maturation of germ cells. Pierson Smela, Kramme et al. found that growing these granulosa-like cells together with germ cells (also generated via iPSCs) resulted in structures similar to ovarian follicles which help eggs develop. These findings could help researchers build stable systems for studying how granulosa cells behave in human ovaries. This could lead to new insights about reproductive health.


Asunto(s)
Células Madre Pluripotentes Inducidas , Factores de Transcripción , Humanos , Femenino , Factores de Transcripción/metabolismo , Ovario/metabolismo , Oogénesis , Diferenciación Celular
15.
G3 (Bethesda) ; 12(3)2022 03 04.
Artículo en Inglés | MEDLINE | ID: mdl-35100363

RESUMEN

Two PIEZO mechanosensitive cation channels, PIEZO1 and PIEZO2, have been identified in mammals, where they are involved in numerous sensory processes. While structurally similar, PIEZO channels are expressed in distinct tissues and exhibit unique properties. How different PIEZOs transduce force, how their transduction mechanism varies, and how their unique properties match the functional needs of the tissues they are expressed in remain all-important unanswered questions. The nematode Caenorhabditis elegans has a single PIEZO ortholog (pezo-1) predicted to have 12 isoforms. These isoforms share many transmembrane domains but differ in those that distinguish PIEZO1 and PIEZO2 in mammals. We used transcriptional and translational reporters to show that putative promoter sequences immediately upstream of the start codon of long pezo-1 isoforms predominantly drive green fluorescent protein (GFP) expression in mesodermally derived tissues (such as muscle and glands). In contrast, sequences upstream of shorter pezo-1 isoforms resulted in GFP expression primarily in neurons. Putative promoters upstream of different isoforms drove GFP expression in different cells of the same organs of the digestive system. The observed unique pattern of complementary expression suggests that different isoforms could possess distinct functions within these organs. We used mutant analysis to show that pharyngeal muscles and glands require long pezo-1 isoforms to respond appropriately to the presence of food. The number of pezo-1 isoforms in C. elegans, their putative differential pattern of expression, and roles in experimentally tractable processes make this an attractive system to investigate the molecular basis for functional differences between members of the PIEZO family of mechanoreceptors.


Asunto(s)
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animales , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Ingestión de Alimentos , Canales Iónicos/metabolismo , Mecanorreceptores/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo
16.
Adv Physiol Educ ; 46(1): 45-55, 2022 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-34735306

RESUMEN

Introductory anatomy and physiology courses are either taught as discipline-specific courses (human anatomy and human physiology) or integrated sequences [combined human anatomy and physiology (A&P I and A&P II)]. This variation suggests there is no agreed upon pedagogical standard for teaching introductory anatomy and physiology. We surveyed undergraduate students enrolled in human anatomy, human physiology, A&P I, and A&P II to determine their course approach preference, either discipline-specific or an integrated A&P sequence, and the underlying reasons for their preferences. The literature suggests that understanding students' preferred learning environment influences learner satisfaction, level of achievement, and socioemotional adjustment in the classroom. Our qualitative analysis revealed students prefer an integrated A&P course approach to a discipline-specific sequence with "building on prior knowledge," "easier," and "increased understanding" emerging as the top reasons for their preferences. Our findings have implications for course design and curricular reforms.


Asunto(s)
Anatomía , Fisiología , Anatomía/educación , Curriculum , Evaluación Educacional , Humanos , Satisfacción Personal , Fisiología/educación , Estudiantes , Encuestas y Cuestionarios
17.
J Med Radiat Sci ; 69(1): 85-97, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34387031

RESUMEN

INTRODUCTION: Aimed to develop a simple and robust volumetric modulated arc radiotherapy (VMAT) solution for comprehensive lymph node (CLN) breast cancer without increase in low-dose wash. METHODS: Forty CLN-breast patient data sets were utilised to develop a knowledge-based planning (KBP) VMAT model, which limits low-dose wash using iterative learning and base-tangential methods as benchmark. Another twenty data sets were employed to validate the model comparing KBP-generated ipsilateral VMAT (ipsi-VMAT) plans against the benchmarked hybrid (h)-VMAT (departmental standard) and bowtie-VMAT (published best practice) methods. Planning target volume (PTV), conformity/homogeneity index (CI/HI), organ-at-risk (OAR), remaining-volume-at-risk (RVR) and blinded radiation oncologist (RO) plan preference were evaluated. RESULTS: Ipsi- and bowtie-VMAT plans were dosimetrically equivalent, achieving greater nodal target coverage (P < 0.05) compared to h-VMAT with minor reduction in breast coverage. CI was enhanced for a small reduction in breast HI with improved dose sparing to ipsilateral-lung and humeral head (P < 0.05) at immaterial expense to spinal cord. Significantly, low-dose wash to OARs and RVR were comparable between all plan types demonstrating a simple VMAT class solution robust to patient-specific anatomic variation can be applied to CLN breast without need for complex beam modification (hybrid plans, avoidance sectors or other). This result was supported by blinded RO review. CONCLUSIONS: A simple and robust ipsilateral VMAT class solution for CLN breast generated using iterative KBP modelling can achieve clinically acceptable target coverage and OAR sparing without unwanted increase in low-dose wash associated with increased second malignancy risk.


Asunto(s)
Oncología por Radiación , Radioterapia de Intensidad Modulada , Humanos , Bases del Conocimiento , Órganos en Riesgo , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia de Intensidad Modulada/métodos
18.
J Neurochem ; 160(2): 234-255, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34816431

RESUMEN

The nervous system monitors the environment to maintain homeostasis, which can be affected by stressful conditions. Using mammalian models of chronic stress, we previously observed altered brain levels of GPM6A, a protein involved in neuronal morphology. However, GPM6A's role in systemic stress responses remains unresolved. The nematode Caenorhabditis elegans expresses a GPM6A ortholog, the neuronal membrane glycoprotein 1 (NMGP-1). Because of the shared features between nematode and mammalian nervous systems and the vast genetic tools available in C. elegans, we used the worm to elucidate the role of GPM6A in the stress response. We first identified nmgp-1 expression in different amphid and phasmid neurons. To understand the nmgp-1 role, we characterized the behavior of nmgp-1(RNAi) animals and two nmgp-1 mutant alleles. Compared to control animals, mutant and RNAi-treated worms exhibited increased recovery time from the stress-resistant dauer stage, altered SDS chemosensation and reduced egg-laying rate resulting in egg retention (bag-of-worms phenotype). Silencing of nmgp-1 expression induced morphological abnormalities in the ASJ sensory neurons, partly responsible for dauer exit. These results indicate that nmgp-1 is required for neuronal morphology and for behaviors associated with chemosensation. Finally, we propose nmgp-1 mutants as a tool to screen drugs for human nervous system pathologies.


Asunto(s)
Adaptación Fisiológica/fisiología , Conducta Animal/fisiología , Caenorhabditis elegans/fisiología , Glicoproteínas de Membrana/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Animales , Proteínas de Caenorhabditis elegans/metabolismo , Femenino
19.
Brain Sci ; 11(11)2021 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-34827456

RESUMEN

Background: This is a retrospective study aimed at assessing the volumetric response, morbidity and failure rates of hypofractionated radiation therapy (HFRT) for definitive focal management of limited brain metastasis. Methods: Patients managed with HFRT for unresected limited metastatic (≤10 lesions) brain disease were entered into an ethics-approved database. Included patients had been deemed unsuitable for surgical resection, and lesions managed with prior radiation therapy were excluded. HFRT was delivered using IMRT or VMAT with 25 Gy or 30 Gy in five fractions. Individual lesions had volumetric assessment performed at three timepoints. The primary endpoint was the change of volume from baseline (GTV0) to one month post-HFRT (GTV1) and to seven months post-HFRT (GTV7). Secondary endpoints were local failure, survival and rates of radiation necrosis. Results: One hundred and twenty-four patients with 233 lesions were managed with HFRT. Median follow-up was 23.5 months with 32 (25.8%) patients alive at censure. Median overall survival was 7.3 months with 36.3% survival at 12 months. Superior survival was predicted by smaller GTV0 (p = 0.003) and increased percentage of volumetric response (p < 0.001). Systemic therapy was delivered to 81.5% of patients. At one month post-HFRT, 206 metastases (88.4%) were available for assessment and at seven months post-HFRT, 118 metastases (50.6%) were available. Median metastasis volume at GTV0 was 1.6 cm3 (range: 0.1-19.1). At GTV1 and GTV7, this reduced to 0.7 cm3 (p < 0.001) and 0.3 cm3 (p < 0.001), respectively, correlating to percentage reductions of 54.9% and 83.3%. No significant predictors of volumetric response following HFRT were identified. Local failure was identified in 4.3% of lesions and radiation necrosis in 3.9%. Conclusion: HFRT is an effective therapy for limited metastatic disease in the brain to maximise initial volumetric response whilst minimising toxicity.

20.
J Vis Exp ; (176)2021 10 25.
Artículo en Inglés | MEDLINE | ID: mdl-34747394

RESUMEN

The physicochemical characterization of nanomaterials (NMs) is often an analytical challenge, due to their small size (at least one dimension in the nanoscale, i.e. 1-100 nm), dynamic nature, and diverse properties. At the same time, reliable and repeatable characterization is paramount to ensure safety and quality in the manufacturing of NM-bearing products. There are several methods available to monitor and achieve reliable measurement of nanoscale-related properties, one example of which is Ultraviolet-Visible Spectroscopy (UV-Vis). This is a well-established, simple, and inexpensive technique that provides non-invasive and fast real-time screening evaluation of NM size, concentration, and aggregation state. Such features make UV-Vis an ideal methodology to assess the proficiency testing schemes (PTS) of a validated standard operating procedure (SOP) intended to evaluate the performance and reproducibility of a characterization method. In this paper, the PTS of six partner laboratories from the H2020 project ACEnano were assessed through an interlaboratory comparison (ILC). Standard gold (Au) colloid suspensions of different sizes (ranging 5-100 nm) were characterized by UV-Vis at the different institutions to develop an implementable and robust protocol for NM size characterization.


Asunto(s)
Oro , Nanoestructuras , Oro/química , Nanoestructuras/química , Reproducibilidad de los Resultados , Espectrofotometría Ultravioleta/métodos , Agua/química
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