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1.
Acta Neuropathol Commun ; 12(1): 99, 2024 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-38886865

RESUMO

Filaments made of residues 120-254 of transmembrane protein 106B (TMEM106B) form in an age-dependent manner and can be extracted from the brains of neurologically normal individuals and those of subjects with a variety of neurodegenerative diseases. TMEM106B filament formation requires cleavage at residue 120 of the 274 amino acid protein; at present, it is not known if residues 255-274 form the fuzzy coat of TMEM106B filaments. Here we show that a second cleavage appears likely, based on staining with an antibody raised against residues 263-274 of TMEM106B. We also show that besides the brain TMEM106B inclusions form in dorsal root ganglia and spinal cord, where they were mostly found in non-neuronal cells. We confirm that in the brain, inclusions were most abundant in astrocytes. No inclusions were detected in heart, liver, spleen or hilar lymph nodes. Based on their staining with luminescent conjugated oligothiophenes, we confirm that TMEM106B inclusions are amyloids. By in situ immunoelectron microscopy, TMEM106B assemblies were often found in structures resembling endosomes and lysosomes.


Assuntos
Proteínas de Membrana , Proteínas do Tecido Nervoso , Proteínas de Membrana/metabolismo , Humanos , Proteínas do Tecido Nervoso/metabolismo , Medula Espinal/metabolismo , Amiloide/metabolismo , Gânglios Espinais/metabolismo , Encéfalo/metabolismo , Masculino , Feminino , Sistema Nervoso Periférico/metabolismo , Idoso , Animais
2.
Br Dent J ; 236(7): 528-532, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38609611

RESUMO

Some dentists choose to ignore the subject of occlusion, while others propose a set of doctrinal rules. It is of little wonder therefore that it can become a source of confusion and even controversy. This series of two papers aims, firstly, to answer the very simple question of 'what is occlusion?'. It will put occlusion into the context of the articulatory system because that is the bio-mechanical environment where the majority of dentists do their work. The concept of jaw relation will also be discussed but within the context of this locomotive system. Ideal occlusion will be described but only after answering the question: for whom or what might an occlusion be considered ideal? Although, in the book of which this is the first chapter, he presents what has worked for him during many years as a general dental practitioner, university lecturer and specialist in restorative dentistry, he has tried not to be didactic because he feels that, in a profession, there are no right answers, only the right questions.


Assuntos
Odontólogos , Papel Profissional , Humanos , Masculino , Oclusão Dentária , Odontologia , Emoções
3.
Br Dent J ; 236(6): 447-452, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38519673

RESUMO

Some dentists choose to ignore the subject of occlusion, while others propose a set of doctrinal rules. It is of little wonder therefore that it can become a source of confusion and even controversy. This series of two papers aims, firstly, to answer the very simple question of 'what is occlusion?'. It will put occlusion into the context of the articulatory system because that is the bio-mechanical environment where the majority of dentists do their work. The concept of jaw relation will also be discussed but within the context of this locomotive system. Ideal occlusion will be described but only after answering the question: for whom or what might an occlusion be considered ideal? Although, in the book of which this is the first chapter, he presents what has worked for him during many years as a general dental practitioner, university lecturer and specialist in restorative dentistry, he has tried not to be didactic because he feels that, in a profession, there are no right answers, only the right questions.


Assuntos
Odontólogos , Papel Profissional , Humanos , Oclusão Dentária , Odontologia
4.
J Oral Rehabil ; 51(5): 785-794, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38151896

RESUMO

BACKGROUND: Despite advances in temporomandibular disorders' (TMDs) diagnosis, the diagnostic process continues to be problematic in non-specialist settings. OBJECTIVE: To complete a Delphi process to shorten the Diagnostic Criteria for TMD (DC/TMD) to a brief DC/TMD (bDC/TMD) for expedient clinical diagnosis and initial management. METHODS: An international Delphi panel was created with 23 clinicians representing major specialities, general dentistry and related fields. The process comprised a full day workshop, seven virtual meetings, six rounds of electronic discussion and finally an open consultation at a virtual international symposium. RESULTS: Within the physical axis (Axis 1), the self-report Symptom Questionnaire of the DC/TMD did not require shortening from 14 items for the bDC/TMD. The compulsory use of the TMD pain screener was removed reducing the total number of Axis 1 items by 18%. The DC/TMD Axis 1 10-section examination protocol (25 movements, up to 12 sets of bilateral palpations) was reduced to four sections in the bDC/TMD protocol involving three movements and three sets of palpations. Axis I then resulted in two groups of diagnoses: painful TMD (inclusive of secondary headache), and common joint-related TMD with functional implications. The psychosocial axis (Axis 2) was shortened to an ultra-brief 11 item assessment. CONCLUSION: The bDC/TMD represents a substantially reduced and likely expedited method to establish (grouping) diagnoses in TMDs. This may provide greater utility for settings requiring less granular diagnoses for the implementation of initial treatment, for example non-specialist general dental practice.


Assuntos
Dor Facial , Transtornos da Articulação Temporomandibular , Humanos , Dor Facial/diagnóstico , Cefaleia/diagnóstico , Exame Físico , Palpação
5.
Org Biomol Chem ; 21(42): 8535-8547, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37840474

RESUMO

We describe the synthesis of trihydroxylated cyclohexane ß-amino acids from (-)-shikimic acid, in their cis and trans configuration, and the incorporation of the trans isomer into a trans-2-aminocyclohexanecarboxylic acid peptide chain. Subsequently, the hydroxyl groups were partially or totally deprotected. The structural study of the new peptides by FTIR, CD, solution NMR and DFT calculations revealed that they all fold into a 14-helix secondary structure, similarly to the homooligomer of trans-2-aminocyclohexanecarboxylic acid. This means that the high degree of substitution of the cyclohexane ring of the new residue is compatible with the adoption of a stable helical secondary structure and opens opportunities for the design of more elaborate peptidic foldamers with oriented polar substituents at selected positions of the cycloalkane residues.


Assuntos
Aminoácidos , Ácidos Cicloexanocarboxílicos , Aminoácidos/química , Peptídeos/química , Estrutura Secundária de Proteína
6.
J Histochem Cytochem ; 71(6): 301-320, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37350564

RESUMO

Retinal astrocytes are vital for neuronal homeostasis in the retina. Together with Müller glia, they provide retinal cells with neurotrophic factors, antioxidative support, and defense mechanisms such as the formation of the blood-retinal barrier. Substantial heterogeneity of astrocyte morphology and function represents a challenge for identification of distinct subtypes which may be potential targets for therapeutic purposes. Hence, identification of novel markers of astrocyte subpopulations is highly relevant to better understand the molecular mechanisms involved in retinal development, homeostasis, and pathology. In this study, we observed that the cell cycle regulator, p16INK4a, is expressed in immature astrocytes in the mouse retina. Immunohistochemical analysis showed p16INK4a expression in the optic nerve of wild-type mice from 3 days to 3 months of age and in the nerve fiber layer of the adult mouse retina. Colocalization of p16INK4a expression and glial fibrillary acidic protein (immature/mature astrocyte marker) tends to decrease with age. However, colocalization of p16INK4a expression and vimentin (immature astrocyte marker) remains high in the optic nerve from the early postnatal period to adulthood. The observations from this study provide a valuable tool for further investigations of ocular astrocytes in the developing retina as well as in degenerative retinopathies.


Assuntos
Astrócitos , Inibidor p16 de Quinase Dependente de Ciclina , Camundongos , Animais , Astrócitos/metabolismo , Inibidor p16 de Quinase Dependente de Ciclina/análise , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Neuroglia , Retina/metabolismo , Proteína Glial Fibrilar Ácida/análise , Ciclo Celular
7.
Eur J Med Chem ; 258: 115509, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37343464

RESUMO

Acute myeloid leukaemia (AML) is an aggressive type of leukaemia with low rates of long-term survival. While the current standard of care is based on cytotoxic chemotherapy, a promising emerging approach is differentiation therapy. However, most current differentiating agents target specific mutations and are effective only in certain patient subtypes. To identify agents which may be effective in wider population cohorts, we performed a phenotypic screen with the myeloid marker CD11b and identified a compound series that was able to differentiate AML cell lines in vitro regardless of their mutation status. Structure-activity relationship studies revealed that replacing the formamide and catechol methyl ether groups with sulfonamide and indazole respectively improved the in vitro metabolic profile of the series while maintaining the differentiation profile in multiple cell lines. This optimisation exercise enabled progression of a lead compound to in vivo efficacy testing. Our work supports the promise of phenotypic screening to identify novel small molecules that induce differentiation in a wide range of AML subtypes.


Assuntos
Antineoplásicos , Leucemia Mieloide Aguda , Humanos , Leucemia Mieloide Aguda/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular , Diferenciação Celular , Piridinas/farmacologia
8.
J Org Chem ; 88(13): 8093-8098, 2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-37311064

RESUMO

The synthesis of a range of loline alkaloids is reported. The C(7) and C(7a) stereogenic centers for the targets were formed by the established conjugate addition of lithium (S)-N-benzyl-N-(α-methylbenzyl)amide to tert-butyl 5-benzyloxypent-2-enoate, ensuing enolate oxidation to give an α-hydroxy-ß-amino ester, and then formal exchange of the resultant amino and hydroxyl functionalities (via the intermediacy of the corresponding aziridinium ion) to give an α-amino-ß-hydroxy ester. Subsequent transformation gave a 3-hydroxyprolinal derivative which was converted to the corresponding N-tert-butylsulfinylimine. Mannich-type reaction with the enolate derived from O-Boc protected methyl glycolate then formed the remaining C(1) and C(2) stereogenic centers for the targets. The 2,7-ether bridge was formed by a displacement reaction, completing construction of the loline alkaloid core. Facile manipulations then gave a range of loline alkaloids, including loline itself.


Assuntos
Alcaloides , Alcaloides de Pirrolizidina , Oxirredução , Estereoisomerismo
9.
Br Dent J ; 234(6): 422-426, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36964364

RESUMO

This article will provide an overview of the diagnosis of common temporomandibular disorders (TMDs) and bruxism, along with their relevance in management of tooth wear. When assessing and managing a tooth wear case, the teeth should not be considered in isolation, but as part of the articulatory system, which has three inter-related elements: the teeth, the temporomandibular joints and the masticatory muscles. The presence/absence of bruxism and TMD are highly relevant, although there may not be a causal relationship between these. A consideration of TMD and bruxism, together with the potential impact these may have on the patient during and after any management of tooth wear, will form part of patient education and the informed consent process.


Assuntos
Bruxismo , Transtornos da Articulação Temporomandibular , Atrito Dentário , Humanos , Bruxismo/complicações , Bruxismo/diagnóstico , Transtornos da Articulação Temporomandibular/complicações , Transtornos da Articulação Temporomandibular/diagnóstico , Articulação Temporomandibular
10.
iScience ; 25(8): 104787, 2022 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-35992086

RESUMO

Despite much progress in developing better drugs, many patients with acute myeloid leukemia (AML) still die within a year of diagnosis. This is partly because it is difficult to identify therapeutic targets that are effective across multiple AML subtypes. One common factor across AML subtypes is the presence of a block in differentiation. Overcoming this block should allow for the identification of therapies that are not dependent on a specific mutation for their efficacy. Here, we used a phenotypic screen to identify compounds that stimulate differentiation in genetically diverse AML cell lines. Lead compounds were shown to decrease tumor burden and to increase survival in vivo. Using multiple complementary target deconvolution approaches, these compounds were revealed to be anti-mitotic tubulin disruptors that cause differentiation by inducing a G2-M mitotic arrest. Together, these results reveal a function for tubulin disruptors in causing differentiation of AML cells.

11.
J Clin Virol ; 155: 105248, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35952426

RESUMO

Background The COVID-19 pandemic continues to devastate communities all over the world. The aim of this study was to evaluate the efficacy and safety of the test agent as a prophylaxis against SARS-CoV-2 infection in a population of high-risk healthcare workers. Methods The study was a multi-centre, prospective, double blind, randomized, placebo-controlled trial. Key eligibility criteria included absence of significant co-morbidity and no previous SARS-CoV-2 infection or vaccination. Participants were randomised to either the active agent nasal spray or placebo using computer generated random number tables. The nasal spray was administered 3 times daily over a 45 day course. The primary end point was the percentage of subjects who tested positive for IgGS (anti-spike, immunoglobulin G specific to the spike protein of SARS-CoV-2) at day 45. Results Between 16th April 2021 and 26th July 2021, 556 participants were analysed for the primary endpoint (275 Test; 281 Placebo). The test agent significantly reduced SARS-CoV-2 infection compared to placebo [36 cases (13.1%) Vs 97 cases (34.5%); OR 0.29 (95% CI; 0.18-0.45), p < 0.0001]. Fewer clinical symptoms were also seen in the test group [57 cases (17.6%) vs 112 cases (34.6%); OR 0.40, (95% CI; 0.27-0.59), p < 0.0001]. No harmful effects were associated with taking the test agent. Conclusion The test agent significantly reduced SARS-CoV-2 infection in healthcare workers, with 62% fewer infections when compared to placebo. It was found to be safe and well tolerated and offers a novel treatment option for prophylaxis against SARS-CoV-2 infection.


Assuntos
COVID-19 , COVID-19/prevenção & controle , Humanos , Sprays Nasais , Pandemias/prevenção & controle , Estudos Prospectivos , SARS-CoV-2
12.
J Nat Prod ; 85(7): 1872-1879, 2022 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-35771599

RESUMO

The first asymmetric synthesis of microgrewiapine C, a piperidine alkaloid isolated from Microcos paniculata, is reported. This synthesis prompted correction of the 1H and 13C NMR data for the natural sample of the alkaloid, which was achieved by reanalysis of the original spectra. The corrected data for the natural product were found to be identical to those of the synthetic sample prepared herein, thus confirming the structural and relative configurational assignment of microgrewiapine C. Although comparison of specific rotation values indicates that the (1R,2S,3S,6S) absolute configuration should be assigned to the alkaloid, consideration of potential common biosynthetic origins of microgrewiapine C and congeners suggests that further phytochemical investigations are warranted.


Assuntos
Alcaloides , Malvaceae , Alcaloides/química , Malvaceae/química , Estrutura Molecular , Piperidinas/química , Estereoisomerismo
13.
Bioorg Med Chem ; 69: 116812, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35772287

RESUMO

A therapeutic approach that holds the potential to treat all Duchenne muscular dystrophy (DMD) patient populations is utrophin modulation. Ezutromid, a first generation utrophin modulator which was later found to act via antagonism of the arylhydrocarbon receptor, progressed to Phase 2 clinical trials. Although interim data showed target engagement and functional improvements, ezutromid ultimately failed to meet its clinical endpoints. We recently described the identification of a new class of hydrazide utrophin modulators which has a different mechanism of action to ezutromid. In this study we report our early optimisation studies on this hydrazide series. The new analogues had significantly improved potency in cell-based assays, increased sp3 character and reduced lipophilicity, which also improved their physicochemical properties. A representative new analogue combining these attributes increased utrophin protein in dystrophic mouse cells showing it can be used as a chemical tool to reveal new insights regarding utrophin upregulation as a strategy for DMD therapeutic intervention.


Assuntos
Distrofia Muscular de Duchenne , Animais , Hidrazinas/farmacologia , Hidrazinas/uso terapêutico , Camundongos , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/tratamento farmacológico , Distrofia Muscular de Duchenne/metabolismo , Relação Estrutura-Atividade , Regulação para Cima , Utrofina/genética , Utrofina/metabolismo , Utrofina/uso terapêutico
14.
Br Dent J ; 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35676461

RESUMO

Introduction Trismus has been identified as a red flag sign that may lead to an early identification of a malignant lesion. A simple checklist was devised to allow clinicians to identify patients who may be at risk.Methods The implementation of this checklist at the temporomandibular disorder clinic of the University Dental Hospital of Manchester has been audited through ten annual cycles, each examining a sample of 50 clinical records of patients referred to the clinic. The standards set were that the presence of the trismus checklist in new patient examination notes should be 100%, the recording of mouth opening should be 100% and that the trismus checklist should be correctly filled in 100% of the time.Results The incidence of trismus ranged from 0-20%. The presence of the trismus checklist in new patient examination notes ranged from 78-100% compliance. The recording of mouth opening ranged from 80-100% compliance. The trismus checklist was not always filled in correctly: it ranged from 50-100%.Conclusion The use of audit has led to the evolution of the checklist and to improvements in its implementation. The trismus checklist has aided the early identification of malignancy. Future work should look at its implementation in a wider range of settings.

15.
J Nat Prod ; 85(1): 306-312, 2022 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-34918520

RESUMO

The formation of O-acetyl microgrewiapine A is investigated. NMR data for the authentic sample derived from the natural product are corrected. Wholly synthetic samples, produced from reductive N-methylation of synthetic microcosamine A (to give synthetic microgrewiapine A) followed by O-acetylation, exhibit NMR data that are identical to those of the authentic sample. The previous report that this two-step transformation proceeds with epimerization at C-6 is thus shown to be in error: the purported sample of O-acetyl 6-epi-microgrewiapine A is structurally misassigned and is, in fact, O-acetyl microgrewiapine A. A plausible rationale for the structural misassignment is advanced.


Assuntos
Alcaloides/química , Piperidinas/química , Acetilação , Alcaloides/síntese química , Produtos Biológicos/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Metilação , Estrutura Molecular , Piperidinas/síntese química , Espectroscopia de Prótons por Ressonância Magnética
16.
eNeuro ; 9(6)2022.
Artigo em Inglês | MEDLINE | ID: mdl-36635241

RESUMO

Alzheimer's Disease (AD) is characterized by the pathologic assembly of amyloid ß (Aß) peptide, which deposits into extracellular plaques, and tau, which accumulates in intraneuronal inclusions. To investigate the link between Aß and tau pathologies, experimental models featuring both pathologies are needed. We developed a mouse model featuring both tau and Aß pathologies by knocking the P290S mutation into murine Mapt and crossing these Mapt P290S knock-in (KI) mice with the App NL-G-F KI line. Mapt P290S KI mice developed a small number of tau inclusions, which increased with age. The amount of tau pathology was significantly larger in App NL-G-F xMapt P290S KI mice from 18 months of age onward. Tau pathology was higher in limbic areas, including hippocampus, amygdala, and piriform/entorhinal cortex. We also observed AT100-positive and Gallyas-Braak-silver-positive dystrophic neurites containing assembled filamentous tau, as visualized by in situ electron microscopy. Using a cell-based tau seeding assay, we showed that Sarkosyl-insoluble brain extracts from both 18-month-old Mapt P290S KI and App NL-G-F xMapt P290S KI mice were seed competent, with brain extracts from double-KI mice seeding significantly more than those from the Mapt P290S KI mice. Finally, we showed that App NL-G-F xMapt P290S KI mice had neurodegeneration in the piriform cortex from 18 months of age. We suggest that App NL-G-F xMapt P290S KI mice provide a good model for studying the interactions of aggregation-prone tau, Aß, neuritic plaques, neurodegeneration, and aging.


Assuntos
Doença de Alzheimer , Animais , Camundongos , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Encéfalo/metabolismo , Modelos Animais de Doenças , Camundongos Transgênicos , Placa Amiloide/patologia , Proteínas tau/genética , Proteínas tau/metabolismo
18.
Molecules ; 26(21)2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34771052

RESUMO

Acute myeloid leukemia (AML) is the most aggressive type of blood cancer, and there is a continued need for new treatments that are well tolerated and improve long-term survival rates in patients. Induction of differentiation has emerged as a promising alternative to conventional cytotoxic chemotherapy, but known agents lack efficacy in genetically distinct patient populations. Previously, we established a phenotypic screen to identify small molecules that could stimulate differentiation in a range of AML cell lines. Utilising this strategy, a 1,5-dihydrobenzo[e][1,4]oxazepin-2(3H)-one hit compound was identified. Herein, we report the hit validation in vitro, structure-activity relationship (SAR) studies and the pharmacokinetic profiles for selected compounds.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Antineoplásicos/síntese química , Linhagem Celular Tumoral , Células Cultivadas , Técnicas de Química Sintética , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Leucemia Mieloide Aguda , Estrutura Molecular , Relação Estrutura-Atividade
19.
J Med Chem ; 64(21): 15608-15628, 2021 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-34672555

RESUMO

Induction of differentiation is a promising therapeutic strategy against acute myeloid leukemia. However, current differentiation therapies are effective only to specific patient populations. To identify novel differentiation agents with wider efficacy, we developed a phenotypic high-throughput screen with a range of genetically diverse cell lines. From the resulting hits, one chemical scaffold was optimized in terms of activity and physicochemical properties to yield OXS007417, a proof-of-concept tool compound, which was also able to decrease tumor volume in a murine in vivo xenograft model.


Assuntos
Antineoplásicos/farmacologia , Leucemia Mieloide Aguda/tratamento farmacológico , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Leucemia Mieloide Aguda/patologia , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/patologia , Fenótipo , Relação Estrutura-Atividade , Células Tumorais Cultivadas
20.
Mater Sociomed ; 33(2): 138-144, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34483743

RESUMO

BACKGROUND: Critically informed discursive research has rarely been used to capture the way psychoanalytic psychotherapists organize their talk with regards to Autism Spectrum Disorders (ASD). OBJECTIVE: To understand the language about autism in psychoanalytic talk in terms of i) interpretive repertoires, ii) subject positions and iii) autistic ways of being that circulate inside psychoanalysts' discourses. METHODS: This paper presents the data and findings of a critical discursive psychological research which analyzed the talk of eight experienced psychoanalysts. As part of a wider research project this study strived to provide an understanding of the way autism was deployed in free associative narrative interviews. RESULTS: Focusing on the micro and the macro level of discourse, the analysis of the data pointed to a rather dilemmatic framework mobilizing therapeutic talk. This framework was organised around a quadrant of interpretive repertoires, which on the one hand fought against the traditional medicalized discourses about autism, while on the other repositioned autism in the same subordinate positions crafted by biomedical regimes. CONCLUSION: A need for breaking from this rather malleable discursive ecosystem is advocated in order to give life to a more democratic let alone emancipating clinical and political environment.

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