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1.
Nucl Med Commun ; 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39267525

RESUMO

OBJECTIVE: Visual assessments of amyloid-ß PET, used for Alzheimer's disease (AD) diagnosis and treatment evaluation, require a careful approach when different PET ligands are utilized. Because the gray matter (GM) and white matter (WM) ligand bindings vary with age, the objective was to investigate the agreement between visual reads of 11C- and 18F-PET scans. METHODS: Cognitively unimpaired (CU) younger adults (N = 30; 39.5 ± 6.0 years), CU older adults (N = 30; 68.6 ± 5.9 years), and adults with AD (N = 22; 67.0 ± 8.5 years) underwent brain MRI, 11C-Pittsburgh compound-B (PiB)-PET, and 18F-flutemetamol-PET. Amyloid-ß deposition was assessed visually by two nuclear medicine specialists on 11C-PiB-PET and 18F-flutemetamol-PET, and quantitatively by PET centiloids. RESULTS: Seventy-two 11C-PiB-PET and 18F-flutemetamol-PET visual reads were concordant. However, 1 18F-flutemetamol-PET and 9 11C-PiB-PET were discordant with quantitative values. In four additional cases, while 11C-PiB-PET and 18F-flutemetamol-PET visual reads were concordant, both were discordant with quantitative values. Disagreements in CU younger adults were only with 11C-PiB-PET visual reads. The remaining disagreements were with CU older adults. CONCLUSION: Age, GM/WM binding, amyloid-ß load, and disease severity may affect visual assessments of PET ligands. Increase in WM binding with age causes a loss of contrast between GM and WM on 11C-PiB-PET, particularly in CU younger adults, leading to false positivity. In CU older adults, increased WM signal may bleed more into cortical regions, hiding subtle cortical uptake, especially with 18F-flutemetamol, whereas 11C-PiB can detect true regional positivity. Understanding these differences will improve patient care and treatment evaluation in clinic and clinical trials.

2.
J Hum Evol ; 195: 103580, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39226621

RESUMO

Thermoregulation is argued to be an important factor influencing body breadth in hominins based on the relationship of surface area to body mass first proposed by Bergmann. Selection for a narrow thorax, and thus a narrow pelvis, increases body surface area relative to body mass, which could be beneficial in hot climates if it leads to a decrease in core body temperature. However, the relationship between pelvic breadth and thermoregulation in humans has not been established. Although previous work has shown that bi-iliac breadth is significantly positively associated with latitude in humans, we lack an understanding of whether this association is due to climate-related selection, neutral evolutionary processes, or other selective pressures. A missing piece of the puzzle is whether body breadth at the iliac blades is an important factor in thermoregulation. Here, we examine this in a mixed-sex sample of 28 adult runners who ran for one hour at 3.14 m s-1 in a variety of climatic conditions while their core body temperatures were measured using internal temperature sensors. The association of maximum core temperature with anthropometric and demographic variables such as age, sex, mass, body fat percentage, and bi-iliac breadth was analyzed using a linear mixed-effect model. Due to the small sample size, the model was also bootstrapped. We found that an increase in absolute bi-iliac breadth was significantly associated with an increase in maximum core temperature. Overall, this preliminary analysis suggests a link between variation in bi-iliac breadth and maximum core body temperature during running, but further investigation is needed.


Assuntos
Regulação da Temperatura Corporal , Temperatura Corporal , Humanos , Masculino , Feminino , Adulto , Regulação da Temperatura Corporal/fisiologia , Ílio/anatomia & histologia , Ílio/fisiologia , Adulto Jovem , Corrida/fisiologia , Pessoa de Meia-Idade
5.
J Pediatr ; : 114323, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39304118

RESUMO

OBJECTIVE: To examine if the annual patient volume of infants born very preterm (VPT, gestational age <32 weeks) at a hospital is associated with neonatal mortality and morbidity. STUDY DESIGN: We performed an observational, secondary data analysis using a 20-year panel of birth certificates linked to hospital discharge abstracts, including transfers in California, Michigan, Missouri, Oregon, Pennsylvania, and South Carolina from 1996 through 2015. The study included all in-hospital VPT deliveries (N=208,261). Study outcomes were in-hospital mortality or serious morbidity (intraventricular hemorrhage, necrotizing enterocolitis, retinopathy of prematurity, or bronchopulmonary dysplasia), attributed to the hospital of birth. Poisson regression models estimated the risk-adjusted relative risk (RR) for mortality and serious morbidity across different patient volume categories within a given hospital using hospital fixed effects. RESULTS: The risk of mortality and serious morbidity for VPT infants increased as the number of infants born VPT at a hospital decreased. Compared with VPT delivery volumes >100 infants per year, the risk of mortality increased when a given hospital had VPT delivery volumes < 60 per year, ranging from a RR of 1.13 (95% C.I. 1.02-1.25) for volumes between 50 to 59 to 1.39 (1.19-1.62) for VPT volumes <10, and the risk of mortality or serious morbidity increased when a given hospital had VPT volumes <100, ranging from a RR of 1.05 (1.02-1.08) for volumes between 90 to 99 and 1.27 (1.19-1.36) for VPT volumes <10. CONCLUSIONS: These results suggest that, for VPT infants, the risk of both mortality and mortality or serious morbidity is increased as the VPT volume within a given hospital declines.

6.
Sci Total Environ ; 954: 176310, 2024 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-39284440

RESUMO

Global plastic production has surged since the 1960s, resulting in the pervasive presence of microplastics in the environment, yet there is a substantial gap in understanding historical trends of plastic pollution in wildlife. Recent discoveries of significant microplastic contamination in fishes have sparked considerable contemporary advancements in analytical methods and hold the potential to fill gaps in historical trends. We measured the presence of microplastics in museum-archived myctophids (Stenobrachius leucopsarus, Diaphus theta, and Tarletonbeania crenularis) collected from 1962 to 2016, to determine if trends in contamination levels over time correspond with the rise in plastics production. Seventy particles were extracted from 57 of the 240 individuals (23.8 % average occurrence across the time series) consisting of primarily blue and black microfibers. Anthropogenically modified cellulose was the dominant material (87 %) identified through µFTIR analysis, with polypropylene and polyethylene particles occurring secondarily. Although the complete time series across a broad geographical range of the North Pacific did not reveal a significant temporal trend, myctophids collected in proximity to the U.S. west coast showed a trend towards increasing incidence of microplastic and microfiber ingestion over time (p ≤ 0.05). Using historical samples of species with higher ingestion levels and consistent collection locations would improve the reliability of future investigations.

7.
Artigo em Inglês | MEDLINE | ID: mdl-39298177

RESUMO

Importance: The most frequent presenting symptom for patients with human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) is a lateral neck mass. Circulating tumor tissue-modified viral (TTMV)-HPV DNA is a unique biomarker produced by the fragmentation of HPV DNA during the degradation of HPV-associated tumors, and its detection and quantitation are currently being used as an adjunct to imaging in monitoring for disease recurrence and may have utility for diagnosis. Objective: To measure the diagnostic characteristics of TTMV-HPV DNA compared with gold standard tissue biopsy for diagnosing HPV-OPSCC in patients presenting with an indeterminate lateral neck mass. Design, Setting, and Participants: This prospective diagnostic test study enrolled patients 18 years or older who presented with a lateral neck mass to a large urban tertiary health care system from December 2021 to June 2023. Participants underwent standard-of-care testing to obtain a tissue diagnosis and a single TTMV-HPV DNA measurement. Main Outcomes and Measures: The primary outcome of interest was sensitivity, while specificity, positive predictive value, and negative predictive value were secondary end points. A subset analysis was performed comparing test performance metrics between TTMV-HPV DNA testing and fine-needle aspiration. Results: A total of 138 patients were included, of whom 80 (58.0%) were men, with median age of 57.5 years (IQR, 43.3-67.0 years). Of 138 patients, 87 (63.0%) had neck masses in level 2 and 47 (34.1%) had HPV-OPSCC. TTMV-HPV DNA testing exhibited a sensitivity of 95.7% (95% CI, 85.5%-99.5% [45 of 47 patients]), specificity of 97.8% (95% CI, 92.3%-99.7% [89 of 91 patients]), positive predictive value of 95.7% (95% CI, 85.5%-99.5% [45 of 47 patients]), and negative predictive value of 97.8% (95% CI, 92.3%-99.7% [89 of 91 patients]). Conclusions and Relevance: In this diagnostic study of patients presenting with a lateral neck mass, circulating TTMV-HPV DNA demonstrated excellent diagnostic test characteristics for the detection of HPV-OPSCC. Such testing may have particular utility for patients in whom obtaining adequate tissue is problematic, as is often the case with cystic neck masses and unknown primary tumors.

8.
Cureus ; 16(8): e68305, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39221314

RESUMO

Calyceal rupture, defined as the extravasation of urine from the renal calyces into the perinephric or paranephric spaces, typically results from increased intrapelvic pressure due to urinary tract obstruction. This condition can lead to the formation of a perinephric urinoma and severe complications, such as infection, abscess formation, and impaired renal function. Timely diagnosis and management are crucial to prevent these adverse outcomes. Calyceal rupture often results from urolithiasis, with other causes including strictures, tumors, and congenital abnormalities. The rupture occurs when intrapelvic pressure exceeds the tensile strength of the calyceal walls, leading to urine leakage and potential inflammation or sepsis. Calyceal ruptures are quite rare, with their exact incidence not well-documented due to the infrequency of the condition and potential underreporting. Although relatively uncommon, the condition is more prevalent in individuals with recurrent nephrolithiasis and other predisposing factors. Timely recognition and intervention, guided by imaging studies such as non-contrast CT scans, are essential. Conservative management with medical therapy is effective in many cases, but surgical intervention may be necessary for larger stones or complications. This report presents the case of a 36-year-old female with calyceal rupture secondary to nephrolithiasis, presenting with severe flank pain. Upon initial presentation, the patient underwent a thorough workup, including imaging studies, appropriate medical management, and continuous monitoring. She was stabilized, her pain was effectively managed, and she was discharged with a scheduled outpatient follow-up. This case highlights the importance of early diagnosis, comprehensive management, and vigilant monitoring in preventing complications and promoting favorable outcomes.

9.
Cureus ; 16(8): e68203, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39221315

RESUMO

Colorectal adenocarcinoma is the most prevalent form of colorectal cancer, representing the majority of cases in the United States. The disease is driven by a series of genetic mutations, including alterations in the adenomatous polyposis coli (APC), Kirsten rat sarcoma viral oncogene homolog G12D (KRAS), human epidermal growth factor receptor 2 immunohistochemistry 3+ (HER-2 IHC3+), checkpoint kinase 2 (CHEK-2) and tumor protein P53 (TP53) genes, which lead to malignant transformation. While the standard treatment for metastatic colorectal cancer (mCRC) typically involves chemotherapy and targeted therapies, many patients experience disease progression, necessitating the exploration of novel treatments. Fruquintinib, a highly selective vascular endothelial growth factor (VEGFR) inhibitor, has emerged as a promising option for mCRC patients who have exhausted conventional therapies. However, its use is associated with significant bleeding risks, including rare but severe complications such as cerebellar hemorrhage. This case report presents a patient with mCRC who developed a cerebellar hemorrhage shortly after initiating fruquintinib therapy, highlighting the need for careful patient monitoring and individualized risk assessment to mitigate such serious adverse events.

10.
J Magn Reson Imaging ; 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39225586

RESUMO

BACKGROUND: Ductal features alone may not offer high diagnostic sensitivity or most accurate disease severity of chronic pancreatitis (CP). PURPOSE: Diagnose CP based on multiparametric MRI and MRCP features. STUDY TYPE: Prospective. POPULATION: Between February 2019 and May 2021, 46 control (23 males, 49.3 ± 14.1 years), 45 suspected (20 males, 48.7 ± 12.5 years), and 46 definite (20 males, 53.7 ± 14.6 years) CP patients were enrolled at seven hospitals enrolled in the MINIMAP study. CP classification was based on imaging findings and clinical presentation. FIELD STRENGTH AND SEQUENCES: 1.5 T. T1-weighted (T1W) spoiled gradient echo, T1 map with variable flip angle, dual-echo Dixon, secretin-enhanced MRCP before and after secretin infusion. ASSESSMENT: Dual-echo fat fraction (FF), T1 relaxation time, extracellular volume (ECV), T1 signal intensity ratio of the pancreas to the spleen (T1 score), arterial-to-venous enhancement ratio (AVR), pancreatic tail diameter (PTD), pancreas volume, late gadolinium enhancement, pancreatic ductal elasticity (PDE), and duodenal filling grade of secretin-enhanced MRCP were measured. STATISTICAL TESTS: Logistic regression analysis generated CP-MRI and secretin-enhanced CP-SMRI scores. Receiver operating characteristics analysis was used to differentiate definite CP from control. Interobserver agreement was assessed using Lin's concordance correlation coefficient. RESULTS: Compared to control, definite CP cohort showed significantly higher dual-echo FF (7% vs. 11%), lower AVR (1.35 vs. 0.85), smaller PTD (2.5 cm vs. 1.95 cm), higher ECV (28% vs. 38%), and higher incidence of PDE loss (6.5% vs. 50%). With the cut-off of >2.5 CP-MRI score (dual-echo FF, AVR, and PTD) and CP-SMRI score (dual-echo FF, AVR, PTD, and PDE) had cross-validated area under the curves of 0.84 (sensitivity 87%, specificity 68%) and 0.86 (sensitivity 89%, specificity 67%), respectively. Interobserver agreement for both CP-MRI and CP-SMRI scores was 0.74. CONCLUSION: The CP-MRI and CP-SMRI scores yielded acceptable performance and interobserver agreement for the diagnosis of CP. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.

11.
Sci Adv ; 10(36): eado0403, 2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-39231223

RESUMO

The current standard method for amino acid signal identification in protein NMR spectra is sequential assignment using triple-resonance experiments. Good software and elaborate heuristics exist, but the process remains laboriously manual. Machine learning does help, but its training databases need millions of samples that cover all relevant physics and every kind of instrumental artifact. In this communication, we offer a solution to this problem. We propose polyadic decompositions to store millions of simulated three-dimensional NMR spectra, on-the-fly generation of artifacts during training, a probabilistic way to incorporate prior and posterior information, and integration with the industry standard CcpNmr software framework. The resulting neural nets take [1H,13C] slices of mixed pyruvate-labeled HNCA spectra (different CA signal shapes for different residue types) and return an amino acid probability table. In combination with primary sequence information, backbones of common proteins (GB1, MBP, and INMT) are rapidly assigned from just the HNCA spectrum.


Assuntos
Proteínas , Proteínas/química , Ressonância Magnética Nuclear Biomolecular/métodos , Software , Aminoácidos/química , Algoritmos , Isótopos/química , Aprendizado de Máquina
12.
Oecologia ; 2024 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-39245757

RESUMO

Increasing atmospheric CO2 levels change the elemental composition in plants, altering their nutritional quality and affecting consumers and ecosystems. Ecological stoichiometry provides a framework for investigating how CO2-driven nutrient dilution in pollen affects bees by linking changes in pollen chemical element proportions to the nutritional needs of bees. We investigated the consequences of five years of Free Air CO2 Enrichment (FACE) in a mature oak-dominated temperate forest on the elemental composition of English oak (Quercus robur) pollen. We measured the concentrations and proportions of 12 elements (C, N, P, S, K, Na, Ca, Mg, Cu, Zn, Fe, and Mn) in Q. robur pollen-bearing flowers collected from the Birmingham Institute for Forest Research (BIFoR) FACE facility. An elevated CO2 (eCO2) level of 150 ppm above ambient significantly reduced the S, K, and Fe levels and altered the multi-element ratio, with different elements behaving differently. This shift in pollen multi-element composition may have subsequent cascading effects on higher trophic levels. To assess the impact on bees, we calculated the stoichiometric mismatch (a measure of the discrepancy between consumer needs and food quality) for two bee species, Osmia bicornis (red mason bee) and Apis mellifera (honey bee), that consume oak pollen in nature. We observed stoichiometric mismatches for P and S, in pollen under eCO2, which could negatively affect bees. We highlight the need for a comprehensive understanding of the changes in pollen multi-element stoichiometry under eCO2, which leads to nutrient limitations under climate change with consequences for bees.

13.
Palliat Med ; : 2692163241271049, 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39248200
14.
Plant Cell Environ ; 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39253967

RESUMO

Freezing air temperatures kill most leaves, yet the leaves of some species can survive these events. Tracking the temporal and spatial dynamics of freezing remains an impediment to characterizing frost tolerance. Here we deploye time-lapse imaging and image subtraction analysis, coupled with fine wire thermocouples, to discern the in situ spatial dynamics of freezing and thawing. Our method of analysis of pixel brightness reveals that ice formation in leaves exposed to natural frosts initiates in mesophyll before spreading to veins, and that while ex situ xylem sap freezes near 0°C, in situ xylem sap has a freezing point of -2°C in our model freezing-resistant species of Lonicera. Photosynthetic rates in leaves that have been exposed to a rapid freeze or thaw do not recover, but leaves exposed to a slow, natural freezing and thawing to -10°C do recover. Using this method, we are able to quantify the spatial formation and timing of freezing events in leaves, and suggest that in situ and ex situ freezing points for xylem sap can differ by more than 4°C depending on the rate of temperature decline.

15.
Proc Natl Acad Sci U S A ; 121(39): e2413100121, 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39292747

RESUMO

The adenosine di-phosphate (ADP) ribosylation factor (Arf) small guanosine tri-phosphate (GTP)ases function as molecular switches to activate signaling cascades that control membrane organization in eukaryotic cells. In Arf1, the GDP/GTP switch does not occur spontaneously but requires guanine nucleotide exchange factors (GEFs) and membranes. Exchange involves massive conformational changes, including disruption of the core ß-sheet. The mechanisms by which this energetically costly switch occurs remain to be elucidated. To probe the switch mechanism, we coupled pressure perturbation with nuclear magnetic resonance (NMR), Fourier Transform infra-red spectroscopy (FTIR), small-angle X-ray scattering (SAXS), fluorescence, and computation. Pressure induced the formation of a classical molten globule (MG) ensemble. Pressure also favored the GDP to GTP transition, providing strong support for the notion that the MG ensemble plays a functional role in the nucleotide switch. We propose that the MG ensemble allows for switching without the requirement for complete unfolding and may be recognized by GEFs. An MG-based switching mechanism could constitute a pervasive feature in Arfs and Arf-like GTPases, and more generally, the evolutionarily related (Ras-like small GTPases) Rags and Gα GTPases.


Assuntos
Fator 1 de Ribosilação do ADP , Guanosina Difosfato , Guanosina Trifosfato , Guanosina Difosfato/metabolismo , Fator 1 de Ribosilação do ADP/metabolismo , Fator 1 de Ribosilação do ADP/química , Fator 1 de Ribosilação do ADP/genética , Guanosina Trifosfato/metabolismo , Humanos , Espalhamento a Baixo Ângulo , Difração de Raios X , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Fatores de Troca do Nucleotídeo Guanina/química , Conformação Proteica , Espectroscopia de Infravermelho com Transformada de Fourier , Modelos Moleculares
16.
ACS Nano ; 2024 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-39288450

RESUMO

We report the bottom-up synthesis of colloidal two-dimensional (2D) layered silicon carbide (SiC) quantum dots with a cubic structure, lateral size of 5-10 nm, ⟨110⟩ exfoliation to few atomic layers, and surface passivation with 1-dodecene. Samples shielded from oxygen and plasma-annealed for purity exhibit narrow blue photoluminescence (PL) with quantum yields (QYs) over 60% in exceptional cases, while unshielded nanocrystals (NCs) exhibit broad blue/green/white PL with 10-15% QY. The latter scenario is attributed to excess surface carbon and oxygen accrued during synthesis and processing, with size separation through ultracentrifugation revealing size-dependent impurity emission. In contrast, the shape of the bright narrow blue PL shows little variation with NC size, while in both scenarios, the maximum QY occurs near four atomic layers. When dried under heat, the disk-like NC suspensions are observed to aggregate into microscale domains, with further self-assembly into planar superlattice domains with common crystalline orientation. The results are compared with photophysical simulations and bring clarity to the broad emission commonly reported for top-down approaches, while inspiring bottom-up schemes directed at improved material quality.

17.
Radiographics ; 44(10): e240036, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39298353

RESUMO

Skull base chordomas and chondrosarcomas are distinct types of rare, locally aggressive mesenchymal tumors that share key principles of imaging investigation and multidisciplinary care. Maximal safe surgical resection is the treatment choice for each, often via an expanded endoscopic endonasal approach, with or without multilayer skull base repair. Postoperative adjuvant radiation therapy is frequently administered, usually with particle therapy such as proton beam therapy (PBT). Compared with photon therapy, PBT enables dose escalation while limiting damage to dose-limiting neurologic structures, particularly the brainstem and optic apparatus, due to energy deposition being delivered at a high maximum with a rapid decrease at the end of the penetration range (Bragg peak phenomenon). Essential requirements for PBT following gross total or maximal safe resection are tissue diagnosis, minimal residual tumor after resection, and adequate clearance from PBT dose-limiting structures. The radiologist should understand surgical approaches and surgical techniques, including multilayer skull base repair, and be aware of evolution of postsurgical imaging appearances over time. Accurate radiologic review of all relevant preoperative imaging examinations and of intraoperative and postoperative MRI examinations plays a key role in management. The radiology report should reflect what the skull base surgeon and radiation oncologist need to know, including distance between the tumor and PBT dose-limiting structures, tumor sites that may be difficult to access via the endoscopic endonasal route, the relationship between intradural tumor and neurovascular structures, and tumor sites with implications for postresection stability. ©RSNA, 2024 Supplemental material is available for this article.


Assuntos
Condrossarcoma , Cordoma , Terapia com Prótons , Neoplasias da Base do Crânio , Humanos , Neoplasias da Base do Crânio/diagnóstico por imagem , Neoplasias da Base do Crânio/radioterapia , Neoplasias da Base do Crânio/cirurgia , Cordoma/diagnóstico por imagem , Cordoma/radioterapia , Cordoma/cirurgia , Condrossarcoma/radioterapia , Condrossarcoma/diagnóstico por imagem , Condrossarcoma/cirurgia , Terapia com Prótons/métodos , Imageamento por Ressonância Magnética/métodos
19.
Brain Commun ; 6(5): fcae300, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39291164

RESUMO

There is increasing interest in Alzheimer's disease related plasma biomarkers due to their accessibility and scalability. We hypothesized that integrating plasma biomarkers with other commonly used and available participant data (MRI, cardiovascular factors, lifestyle, genetics) using machine learning (ML) models can improve individual prediction of cognitive outcomes. Further, our goal was to evaluate the heterogeneity of these predictors across different age strata. This longitudinal study included 1185 participants from the Mayo Clinic Study of Aging who had complete plasma analyte work-up at baseline. We used the Quanterix Simoa immunoassay to measure neurofilament light, Aß1-42 and Aß1-40 (used as Aß42/Aß40 ratio), glial fibrillary acidic protein, and phosphorylated tau 181 (p-tau181). Participants' brain health was evaluated through gray and white matter structural MRIs. The study also considered cardiovascular factors (hyperlipidemia, hypertension, stroke, diabetes, chronic kidney disease), lifestyle factors (area deprivation index, body mass index, cognitive and physical activities), and genetic factors (APOE, single nucleotide polymorphisms, and polygenic risk scores). An ML model was developed to predict cognitive outcomes at baseline and decline (slope). Three models were created: a base model with groups of risk factors as predictors, an enhanced model included socio-demographics, and a final enhanced model by incorporating plasma and socio-demographics into the base models. Models were explained for three age strata: younger than 65 years, 65-80 years, and older than 80 years, and further divided based on amyloid positivity status. Regardless of amyloid status the plasma biomarkers showed comparable performance (R² = 0.15) to MRI (R² = 0.18) and cardiovascular measures (R² = 0.10) when predicting cognitive decline. Inclusion of cardiovascular or MRI measures with plasma in the presence of socio-demographic improved cognitive decline prediction (R² = 0.26 and 0.27). For amyloid positive individuals Aß42/Aß40, glial fibrillary acidic protein and p-tau181 were the top predictors of cognitive decline while Aß42/Aß40 was prominent for amyloid negative participants across all age groups. Socio-demographics explained a large portion of the variance in the amyloid negative individuals while the plasma biomarkers predominantly explained the variance in amyloid positive individuals (21% to 37% from the younger to the older age group). Plasma biomarkers performed similarly to MRI and cardiovascular measures when predicting cognitive outcomes and combining them with either measure resulted in better performance. Top predictors were heterogeneous between cross-sectional and longitudinal cognition models, across age groups, and amyloid status. Multimodal approaches will enhance the usefulness of plasma biomarkers through careful considerations of a study population's socio-demographics, brain and cardiovascular health.

20.
Cureus ; 16(9): e68866, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39246637

RESUMO

Calciphylaxis, also known as calcific uremic arteriolopathy, is a rapidly progressive, rare, and severe condition characterized by vascular calcification and skin necrosis. The pathophysiology involves cutaneous arteriolar calcification followed by subsequent tissue ischemia and infarction, which eventually causes extremely painful skin lesions. The condition is associated with substantial morbidity due to severe pain, non-healing wounds, increased susceptibility to infections, and frequent hospitalizations. Calciphylaxis is a highly fatal condition with one-year mortality rates greater than 50%, most frequently due to sepsis. This report presents a case of a 63-year-old male with end-stage kidney disease (ESKD) who presented with altered mental status and was found to have notable necrotic skin ulcers on the bilateral anterior thighs, a stage IV sacral decubitus ulcer, and necrotic lesions on the scrotum and penis. This case underscores the importance of maintaining a high clinical suspicion for rare conditions like calciphylaxis in patients with multiple risk factors. Diagnosing the disease earlier in its course may improve outcomes and overall prognosis. Unfortunately, in this case, the patient presented too late into the disease course, and ultimately discussions/placement with palliative care were undertaken.

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