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2.
J Org Chem ; 89(14): 9910-9922, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-38959240

RESUMO

A modular, enantioselective approach to access the bioactive 7,9-dihydroxy- and 9-hydroxy-7-keto-8,4'-oxyneolignans is disclosed, which employs stereoselective Mitsunobu reactions of enantiopure 2-aryl-1,3-dioxan-5-ols and functionalized phenols. The enantiopure dioxanols are prepared through Sharpless asymmetric dihydroxylation of protected coniferyl or sinapyl alcohols and subsequent benzylidene acetal formation. Through a mix-and-match coupling approach, six of the eight possible erythro-7,9-dihydroxy-8,4'-oxyneolignan enantiomeric natural products (bearing a C-1' hydroxypropyl chain) were generated following sequential deprotection. Subsequent benzylic oxidation afforded the 7-keto-derivatives, resulting in enantioselective syntheses of each enantiomer of the natural products asprenol B and icariol A1.

3.
Biol Psychol ; 192: 108847, 2024 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-39038634

RESUMO

The locus coeruleus (LC) produces the neuromodulators norepinephrine and dopamine, and projects widely to subcortical and cortical brain regions. The LC has been a focus of neuroimaging biomarker development for the early detection of Alzheimer's disease (AD) since it was identified as one of the earliest brain regions to develop tau pathology. Our recent research established the use of positron emission tomography (PET) to measure LC catecholamine synthesis capacity in cognitively unimpaired older adults. We extend this work by investigating the possible influence of pathology and LC neurochemical function on LC network activity using functional magnetic resonance imaging (fMRI). In separate sessions, participants underwent PET imaging to measure LC catecholamine synthesis capacity ([18F]Fluoro-m-tyrosine), tau pathology ([18F]Flortaucipir), and amyloid-ß pathology ([11C]Pittsburgh compound B), and fMRI imaging to measure LC functional network activity at rest. Consistent with a growing body of research in aging and preclinical AD, we find that higher functional network activity is associated with higher tau burden in individuals at risk of developing AD (amyloid-ß positive). Critically, relationships between higher LC network activity and higher pathology (amyloid-ß and tau) were moderated by LC catecholamine synthesis capacity. High levels of LC catecholamine synthesis capacity reduced relationships between higher network activity and pathology. Broadly, these findings support the view that individual differences in functional network activity are shaped by interactions between pathology and neuromodulator function, and point to catecholamine systems as potential therapeutic targets.

4.
J Learn Disabil ; : 222194241263646, 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39056893

RESUMO

Establishing validated science programs for students with or at risk for learning disabilities requires testing treatment effects and exploring differential response patterns. This study explored whether students' initial mathematics and reading skills influenced their treatment response to a whole-class, second-grade science program called Scientific Explorers (Sci2). The original Sci2 study employed a cluster randomized controlled design and included 294 students from 18 second-grade classrooms. Differential effects of the program by initial mathematics and reading skill levels were not observed for an interactive science assessment and a distal science outcome measure. However, based on initial reading skill levels, moderation results were found on a science vocabulary measure, suggesting the effects of Sci2 were greatest for students with higher initial reading skills. Similar results were found using initial mathematics skill levels as a predictor of differential response such that students with higher mathematics skills reaped stronger treatment effects on the vocabulary measure. Further, we found initial mathematics skills also influenced outcomes on the proximal science content assessment, where students with higher initial mathematics skills led to higher outcomes. Overall, findings suggest Sci2 produced robust effects for all students (g = 0.24-1.23), regardless of initial skill proficiencies. Implications for exploring differential response in science intervention research are discussed.

5.
EBioMedicine ; 106: 105227, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39018754

RESUMO

BACKGROUND: A highly effective vaccine for malaria remains an elusive target, at least in part due to the under-appreciated natural parasite variation. This study aimed to investigate genetic and structural variation, and immune selection of leading malaria vaccine candidates across the Plasmodium falciparum's life cycle. METHODS: We analysed 325 P. falciparum whole genome sequences from Zambia, in addition to 791 genomes from five other African countries available in the MalariaGEN Pf3k Database. Ten vaccine antigens spanning three life-history stages were examined for genetic and structural variations, using population genetics measures, haplotype network analysis, and 3D structure selection analysis. FINDINGS: Among the ten antigens analysed, only three in the transmission-blocking vaccine category display P. falciparum 3D7 as the dominant haplotype. The antigens AMA1, CSP, MSP119 and CelTOS, are much more diverse than the other antigens, and their epitope regions are under moderate to strong balancing selection. In contrast, Rh5, a blood stage antigen, displays low diversity yet slightly stronger immune selection in the merozoite-blocking epitope region. Except for CelTOS, the transmission-blocking antigens Pfs25, Pfs48/45, Pfs230, Pfs47, and Pfs28 exhibit minimal diversity and no immune selection in epitopes that induce strain-transcending antibodies, suggesting potential effectiveness of 3D7-based vaccines in blocking transmission. INTERPRETATION: These findings offer valuable insights into the selection of optimal vaccine candidates against P. falciparum. Based on our results, we recommend prioritising conserved merozoite antigens and transmission-blocking antigens. Combining these antigens in multi-stage approaches may be particularly promising for malaria vaccine development initiatives. FUNDING: Purdue Department of Biological Sciences; Puskas Memorial Fellowship; National Institute of Allergy and Infectious Diseases (U19AI089680).

6.
Aging (Albany NY) ; 16(13): 10694-10723, 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38976646

RESUMO

Idiopathic pulmonary fibrosis (IPF) is an age-related disease with poor prognosis and limited therapeutic options. Activation of lung fibroblasts and differentiation to myofibroblasts are the principal effectors of disease pathology, but damage and senescence of alveolar epithelial cells, specifically type II (ATII) cells, has recently been identified as a potential trigger event for the progressive disease cycle. Targeting ATII senescence and the senescence-associated secretory phenotype (SASP) is an attractive therapeutic strategy; however, translatable primary human cell models that enable mechanistic studies and drug development are lacking. Here, we describe a novel system of conditioned medium (CM) transfer from bleomycin-induced senescent primary alveolar epithelial cells (AEC) onto normal human lung fibroblasts (NHLF) that demonstrates an enhanced fibrotic transcriptional and secretory phenotype compared to non-senescent AEC CM treatment or direct bleomycin damage of the NHLFs. In this system, the bleomycin-treated AECs exhibit classical hallmarks of cellular senescence, including SASP and a gene expression profile that resembles aberrant epithelial cells of the IPF lung. Fibroblast activation by CM transfer is attenuated by pre-treatment of senescent AECs with the senolytic Navitoclax and AD80, but not with the standard of care agent Nintedanib or senomorphic JAK-targeting drugs (e.g., ABT-317, ruxolitinib). This model provides a relevant human system for profiling novel senescence-targeting therapeutics for IPF drug development.


Assuntos
Células Epiteliais Alveolares , Bleomicina , Senescência Celular , Fibroblastos , Fibrose Pulmonar Idiopática , Humanos , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Bleomicina/toxicidade , Bleomicina/farmacologia , Senescência Celular/efeitos dos fármacos , Células Epiteliais Alveolares/efeitos dos fármacos , Células Epiteliais Alveolares/metabolismo , Células Epiteliais Alveolares/patologia , Fibrose Pulmonar Idiopática/patologia , Fibrose Pulmonar Idiopática/metabolismo , Meios de Cultivo Condicionados/farmacologia , Indóis/farmacologia , Fenótipo Secretor Associado à Senescência/efeitos dos fármacos , Pulmão/patologia , Pulmão/citologia , Pulmão/efeitos dos fármacos , Sulfonamidas/farmacologia , Senoterapia/farmacologia , Células Cultivadas , Pirimidinas/farmacologia , Pirazóis/farmacologia , Nitrilas/farmacologia , Compostos de Anilina
7.
Histopathology ; 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39044682

RESUMO

AIMS: Superficial CD34-positive fibroblastic tumour (SCD34FT) is an uncommon but distinctive low-grade neoplasm of the skin and subcutis that shows frequent CADM3 expression by immunohistochemistry (IHC). In this study, prompted by an index case resembling 'atypical fibrous histiocytoma (FH)' that was positive for CADM3 IHC, we systematically examined a cohort of tumours previously diagnosed as 'atypical FH' by applying CADM3 and fluorescence in situ hybridization (FISH) for PRDM10 rearrangement, to investigate the overlap between these tumour types. METHODS AND RESULTS: Forty cases of atypical FH were retrieved, including CD34-positive tumours (n = 20) and CD34-negative tumours (n = 20). All tumours were stained for CADM3. All CADM3-positive tumours were evaluated by FISH to assess for PRDM10 rearrangement. Eleven CD34-positive tumours (11/20, 55%) coexpressed CADM3 and were reclassified as SCD34FT. None (0/20) of the CD34-negative atypical FH were CADM3-positive. Reclassified SCD34FT (10/11) arose on the lower extremity, with frequent involvement of the thigh (n = 8). Features suggestive of atypical FH were observed in many reclassified cases including variable cellularity, spindled morphology, infiltrative tumour margins, collagen entrapment, epidermal hyperpigmentation, and acanthosis. Variably prominent multinucleate giant cells, including Touton-like forms, were also present. An informative FISH result was obtained in 10/11 reclassified tumours, with 60% (6/10) demonstrating PRDM10 rearrangement. CONCLUSION: A significant subset of tumours that histologically resemble atypical FH, and are positive for CD34, coexpress CADM3 and harbour PRDM10 rearrangement, supporting their reclassification as SCD34FT. Awareness of this morphologic overlap and the application of CADM3 IHC can aid the distinction between SCD34FT and atypical FH.

8.
Nat Mater ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38956352

RESUMO

Medium- and high-entropy alloys are an emerging class of materials that can exhibit outstanding combinations of strength and ductility for engineering applications. Computational simulations have suggested the presence of short-range order (SRO) in these alloys, and recent experimental evidence is also beginning to emerge. Unfortunately, the difficulty in quantifying the SRO under different heat treatment conditions has generated much debate on the atomic preferencing and implications of SRO on mechanical properties. Here we develop an approach to measure SRO using atom probe tomography. This method balances the limitations of atom probe tomography with the threshold values of SRO to map the regimes where the required atomistic neighbourhood information is preserved and where it is not. We demonstrate the method with a case study of the CoCrNi alloy and use this to monitor SRO changes induced by heat treatments. These species-specific SRO measurements enable the generation of computational simulations of atomic neighbourhood models that are equivalent to the experiment and can contribute to the further understanding and design of medium- and high-entropy alloys and other materials systems where SRO may occur.

9.
Oncogene ; 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39048659

RESUMO

Solid tumours have abnormally high intracellular [Na+]. The activity of various Na+ channels may underlie this Na+ accumulation. Voltage-gated Na+ channels (VGSCs) have been shown to be functionally active in cancer cell lines, where they promote invasion. However, the mechanisms involved, and clinical relevance, are incompletely understood. Here, we show that protein expression of the Nav1.5 VGSC subtype strongly correlates with increased metastasis and shortened cancer-specific survival in breast cancer patients. In addition, VGSCs are functionally active in patient-derived breast tumour cells, cell lines, and cancer-associated fibroblasts. Knockdown of Nav1.5 in a mouse model of breast cancer suppresses expression of invasion-regulating genes. Nav1.5 activity increases ATP demand and glycolysis in breast cancer cells, likely by upregulating activity of the Na+/K+ ATPase, thus promoting H+ production and extracellular acidification. The pH of murine xenograft tumours is lower at the periphery than in the core, in regions of higher proliferation and lower apoptosis. In turn, acidic extracellular pH elevates persistent Na+ influx through Nav1.5 into breast cancer cells. Together, these findings show positive feedback between extracellular acidification and the movement of Na+ into cancer cells which can facilitate invasion. These results highlight the clinical significance of Nav1.5 activity as a potentiator of breast cancer metastasis and provide further evidence supporting the use of VGSC inhibitors in cancer treatment.

10.
Clin Exp Ophthalmol ; 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39048918

RESUMO

BACKGROUND: To report the clinicopathological features and epidemiology of iris melanoma in Queensland, Australia. METHODS: This was a retrospective study of 86 patients with iris melanoma treated between 2001 and 2022 at the Queensland Ocular Oncology Service, Brisbane, Australia. Main outcome measures included demographics, clinical and phenotypic features, age-adjusted incidence and relative survival. RESULTS: Eighty-six patients (63% female) were included. Mean age was 54 years (range 17-82 years). The majority of patients (97%) were Caucasian, with blue eyes, fair skin and Fitzpatrick Skin Type I or II. Demographic features and clinical history showed a tendency for high ultraviolet radiation (UVR) exposure in the cohort. Histopathology was available in 69 cases (82%), and of these, 77% tumours were of spindle cell origin, with low-risk genetic profiles. Patients were followed for a mean of 8 years (median 7, range 1-21 years) after diagnosis, and only one case of metastasis was documented. CONCLUSIONS: The association of iris freckles, history of UVR exposure and dermatologic findings supports the role of UVR in iris melanoma. Occupation and avocation history, as well as evaluation of iris freckles may offer an easily accessible way of stratifying the risk of an individual for development of UVR-related uveal melanoma.

11.
JAMA Netw Open ; 7(7): e2424076, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-39042406

RESUMO

Importance: Mental health disorders are common after mild traumatic brain injury (mTBI) and likely exacerbate postconcussive symptoms and disability. Early detection could improve clinical outcomes, but the accuracy of mental health screening tools in this population has not been well established. Objective: To determine the diagnostic accuracy of the Patient Health Questionnaire-9 (PHQ-9), Generalizaed Anxiety Disorder-7 (GAD-7), and Primary Care PTSD (Posttramatic Stress Disorder) Screen for Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) (DSM-5) (PC-PTSD-5) in adults with mTBI. Design, Setting, and Participants: This diagnostic study was performed as a secondary analysis of a cluster randomized clinical trial. Self-report mental health screening tools (PHQ-9, GAD-7, and PC-PTSD-5) were administered online 12 weeks after mTBI and compared against a structured psychodiagnostic interview (Mini-International Neuropsychiatric Interview for DSM-5 (MINI) over videoconference at the same time. Adults with mTBI (N = 537) were recruited from February 1, 2021, to October 25, 2022. Main Outcomes and Measures: Presence of a major depressive episode, anxiety disorders, and PTSD were determined by a blinded assessor with the MINI. Diagnostic accuracy statistics were derived for the PHQ-9, GAD-7, and PC-PTSD-5. Findings were disaggregated for participants with and without persistent postconcussion symptoms (PPCS) by International and Statistical Classification of Diseases, Tenth Revision criteria. Results: Data were available for 499 of 537 trial participants, 278 (55.7%) of whom were female; the mean (SD) age was 38.8 (13.9) years. Each screening questionnaire had strong diagnostic accuracy in the overall sample for optimal cut points (area under the curve [AUC], ≥0.80; sensitivity, 0.55-0.94; specificity, 0.64-0.94). The AUC (difference of 0.01-0.13) and specificity (difference, 5-65 percentage points) were lower in those with PPCS present compared with PPCS absent, but the prevalence of at least 1 mental health disorder was 3 to 5 times higher in patients with PPCS present. The GAD-7 had slightly better performance than the PC-PTSD-5 for detecting PTSD (AUC, 0.85 [95% CI, 0.80-0.89] vs 0.80 [95% CI, 0.72-0.87]). The optimal cutoff on the PHQ-9 was 5 or more symptoms experienced on more than half of days; on the GAD-7, a total score of at least 7. Conclusions and Relevance: The findings of this diagnostic study suggest that the PHQ-9, GAD-7 and PC-PTSD-5 accurately screen for mental health disorders in patients with mTBI. Future research should corroborate optimal test cutoffs for this population.


Assuntos
Transtornos de Estresse Pós-Traumáticos , Humanos , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Transtornos de Estresse Pós-Traumáticos/diagnóstico , Síndrome Pós-Concussão/diagnóstico , Síndrome Pós-Concussão/psicologia , Sensibilidade e Especificidade , Concussão Encefálica/diagnóstico , Concussão Encefálica/psicologia , Concussão Encefálica/complicações , Programas de Rastreamento/métodos , Transtornos de Ansiedade/diagnóstico , Transtornos de Ansiedade/etiologia
12.
Genes (Basel) ; 15(7)2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-39062652

RESUMO

Adolescence is a critical developmental period when the brain is plastic, and stress exposure can have lasting physiological consequences. One mechanism through which adolescent stress may have lasting effects is by altering microRNAs (miRNAs), leading to wide-scale gene expression changes. Three prior independent studies used unbiased approaches (RNA sequencing or microarray) to identify miRNAs differentially expressed by chronic variable stress in male rodents. In all three studies, miRNA-200a was differentially expressed in areas of the brain associated with emotion regulation. The current study extends this research to determine if chronic non-variable adolescent stress downregulates miRNA-200a expression by looking at two strains (BALB/cJ and C57BL/6J) of male and female mice. We utilized a 14-day (2 h/day) restraint stress protocol and verified stress effects on adolescent body weight gain and circulating corticosterone concentrations relative to non-restraint controls. Mice were then left undisturbed until they were euthanized in adulthood, at which time brains were collected to measure miRNA-200a in the ventral hippocampus. Three weeks after adolescent stress ended, differences in body weight between groups were no longer significant; however, animals exposed to stress had less miRNA-200a expression in the ventral hippocampus than control animals. These data implicate miRNA-200a expression as a potential mechanism by which adolescent stress can have persistent impacts on multiple outcomes in both male and female mice.


Assuntos
Camundongos Endogâmicos C57BL , MicroRNAs , Restrição Física , Estresse Psicológico , Animais , MicroRNAs/genética , Feminino , Masculino , Camundongos , Estresse Psicológico/genética , Camundongos Endogâmicos BALB C , Regulação para Baixo , Hipocampo/metabolismo , Corticosterona/sangue
13.
Genes (Basel) ; 15(7)2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-39062685

RESUMO

Lung cancer patients treated with targeted therapies frequently respond well but invariably relapse due to the development of drug resistance. Drug resistance is in part mediated by a subset of cancer cells termed "drug-tolerant persisters" (DTPs), which enter a dormant, slow-cycling state that enables them to survive drug exposure. DTPs also exhibit stem cell-like characteristics, broad epigenetic reprogramming, altered metabolism, and a mutagenic phenotype mediated by adaptive mutability. While several studies have characterised the transcriptional changes that lead to the altered phenotypes exhibited in DTPs, these studies have focused predominantly on protein coding changes. As long non-coding RNAs (lncRNAs) are also implicated in the phenotypes altered in DTPs, it is likely that they play a role in the biology of drug tolerance. In this review, we outline how lncRNAs may contribute to the key characteristics of DTPs, their potential roles in tolerance to targeted therapies, and the emergence of genetic resistance in lung adenocarcinoma.


Assuntos
Adenocarcinoma de Pulmão , Resistencia a Medicamentos Antineoplásicos , Neoplasias Pulmonares , RNA Longo não Codificante , Humanos , RNA Longo não Codificante/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Resistencia a Medicamentos Antineoplásicos/genética , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/tratamento farmacológico , Adenocarcinoma de Pulmão/patologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Antineoplásicos/uso terapêutico , Antineoplásicos/farmacologia , Tolerância a Medicamentos/genética
14.
Pathogens ; 13(7)2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-39057790

RESUMO

Cu is an antimicrobial that is commonly applied to premise (i.e., building) plumbing systems for Legionella control, but the precise mechanisms of inactivation are not well defined. Here, we applied a suite of viability assays and mass spectrometry-based proteomics to assess the mechanistic effects of Cu on L. pneumophila. Although a five- to six-log reduction in culturability was observed with 5 mg/L Cu2+ exposure, cell membrane integrity only indicated a <50% reduction. Whole-cell proteomic analysis revealed that AhpD, a protein related to oxidative stress, was elevated in Cu-exposed Legionella relative to culturable cells. Other proteins related to cell membrane synthesis and motility were also higher for the Cu-exposed cells relative to controls without Cu. While the proteins related to primary metabolism decreased for the Cu-exposed cells, no significant differences in the abundance of proteins related to virulence or infectivity were found, which was consistent with the ability of VBNC cells to cause infections. Whereas the cell-membrane integrity assay provided an upper-bound measurement of viability, an amoebae co-culture assay provided a lower-bound limit. The findings have important implications for assessing Legionella risk following its exposure to copper in engineered water systems.

15.
Cell ; 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39059380

RESUMO

The highly conserved and essential Plasmodium falciparum reticulocyte-binding protein homolog 5 (PfRH5) has emerged as the leading target for vaccines against the disease-causing blood stage of malaria. However, the features of the human vaccine-induced antibody response that confer highly potent inhibition of malaria parasite invasion into red blood cells are not well defined. Here, we characterize 236 human IgG monoclonal antibodies, derived from 15 donors, induced by the most advanced PfRH5 vaccine. We define the antigenic landscape of this molecule and establish that epitope specificity, antibody association rate, and intra-PfRH5 antibody interactions are key determinants of functional anti-parasitic potency. In addition, we identify a germline IgG gene combination that results in an exceptionally potent class of antibody and demonstrate its prophylactic potential to protect against P. falciparum parasite challenge in vivo. This comprehensive dataset provides a framework to guide rational design of next-generation vaccines and prophylactic antibodies to protect against blood-stage malaria.

16.
J Natl Compr Canc Netw ; 22(5): 331-357, 2024 07.
Artigo em Inglês | MEDLINE | ID: mdl-39019058

RESUMO

Breast cancer is treated with a multidisciplinary approach involving surgical oncology, radiation oncology, and medical oncology. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Breast Cancer include recommendations for clinical management of patients with carcinoma in situ, invasive breast cancer, Paget's disease, Phyllodes tumor, inflammatory breast cancer, and management of breast cancer during pregnancy. The content featured in this issue focuses on the recommendations for overall management of systemic therapy (preoperative and adjuvant) options for nonmetastatic breast cancer. For the full version of the NCCN Guidelines for Breast Cancer, visit NCCN.org.


Assuntos
Neoplasias da Mama , Humanos , Neoplasias da Mama/terapia , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/patologia , Feminino , Oncologia/normas , Oncologia/métodos , Terapia Combinada/normas
17.
Cureus ; 16(6): e62547, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-39022503

RESUMO

Dermatofibrosarcoma protuberans (DFSP) is a rare, slow-growing, malignant tumor in the dermis and subcutaneous fat diagnosed by pathological and immunohistochemical examinations. This case report provides the dermatological findings of a 73-year-old woman with DFSP who presented to a primary care clinic with a longstanding nodular lesion on her left upper thigh. Dermatological examination showed a solitary, skin-colored violaceous/hyperpigmented nodule on the superior anteromedial portion of the left thigh. A punch biopsy revealed spindle cell proliferation, and diffuse CD34 positivity, confirming the diagnosis of DFSP. A dermatology referral was placed for further management and complete surgical excision. Patient underwent wide local excision (WLE) and has no recurrence to date. Unfortunately, DFSP is commonly misdiagnosed before skin biopsy which delays treatment. This case is significant because DFSP is not often diagnosed accurately outside the dermatology specialty and serves as a reminder to practitioners to use biopsies during the diagnostic process of skin findings to prevent the delay in management.

18.
Artigo em Inglês | MEDLINE | ID: mdl-39024077

RESUMO

Transcranial focused ultrasound (tFUS) procedures such as neuromodulation and blood brain barrier opening require precise focus placement within the brain. MRI is currently the most reliable tool for focus localization but can be prohibitive for procedures requiring recurrent therapies. We designed, fabricated, and characterized a patient-specific, 3D-printed, stereotactic frame for repeated tFUS therapy. The frame is compact with minimal footprint, can be removed and re-secured between treatments while maintaining sub-mm accuracy and will allow for precise and repeatable transcranial FUS treatment without the need for MR-guidance following the initial calibration scan. Focus localization and repeatability were assessed via MR-thermometry and MR-ARFI on an ex vivo skull-phantom and in vivo non-human primates (NHP), respectively. Focal localization, registration, steering, and re-steering were accomplished during the initial MRI calibration scan session. Keeping steering coordinates fixed in subsequent therapy and imaging sessions, we found good agreement between steered foci and intended target, with target registration error of 1.2 ± 0.3 (n = 4, ex vivo) and 1.0 ± 0.5 (n = 3, in vivo) mm. Focus position (steered and non-steered) was consistent, with sub-mm variation in each dimension between studies. Our 3D-printed, patient-specific stereotactic frame can reliably position and orient the ultrasound transducer for repeated targeting of brain regions using a single MR-based calibration. The compact frame allows for high-precision tFUS to be carried out outside the magnet, and could help reduce the cost of tFUS treatments where repeated application of an ultrasound focus is required with high precision.

19.
Sci Rep ; 14(1): 16086, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38992064

RESUMO

The classical amyloid cascade hypothesis postulates that the aggregation of amyloid plaques and the accumulation of intracellular hyperphosphorylated Tau tangles, together, lead to profound neuronal death. However, emerging research has demonstrated that soluble amyloid-ß oligomers (SAßOs) accumulate early, prior to amyloid plaque formation. SAßOs induce memory impairment and disrupt cognitive function independent of amyloid-ß plaques, and even in the absence of plaque formation. This work describes the development and characterization of a novel anti-SAßO (E3) nanobody generated from an alpaca immunized with SAßO. In-vitro assays and in-vivo studies using 5XFAD mice indicate that the fluorescein (FAM)-labeled E3 nanobody recognizes both SAßOs and amyloid-ß plaques. The E3 nanobody traverses across the blood-brain barrier and binds to amyloid species in the brain of 5XFAD mice. Imaging of mouse brains reveals that SAßO and amyloid-ß plaques are not only different in size, shape, and morphology, but also have a distinct spatial distribution in the brain. SAßOs are associated with neurons, while amyloid plaques reside in the extracellular matrix. The results of this study demonstrate that the SAßO nanobody can serve as a diagnostic agent with potential theragnostic applications in Alzheimer's disease.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Placa Amiloide , Anticorpos de Domínio Único , Animais , Peptídeos beta-Amiloides/metabolismo , Peptídeos beta-Amiloides/imunologia , Anticorpos de Domínio Único/imunologia , Anticorpos de Domínio Único/química , Camundongos , Placa Amiloide/metabolismo , Doença de Alzheimer/metabolismo , Humanos , Encéfalo/metabolismo , Encéfalo/patologia , Barreira Hematoencefálica/metabolismo , Camundongos Transgênicos , Camelídeos Americanos , Modelos Animais de Doenças
20.
Chem Commun (Camb) ; 60(60): 7713-7716, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-38967350

RESUMO

This study investigated the ammonia decomposition mechanism over Ru/CeO2. Isotopic tests using ND3 revealed that the rate-determining step involves adsorbed nitrogen atoms on Ru. Moreover, an inverse kinetic isotope effect where ND3 decomposition was faster than NH3 was clearly observed. The origin of the inverse effect was explained by the lower D coverage on the catalyst surface compared to H coverage for mitigating the inhibition of ND3 activation.

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