Publications by authors named "Buchanan D"

Natural cyclic peptides, a diverse class of bioactive compounds, have been isolated from various natural sources and are renowned for their extensive structural variability and broad spectrum of medicinal properties. Over 40 cyclic peptides or their derivatives are currently approved as medicines, underscoring their significant therapeutic potential. These compounds are employed in diverse roles, including antibiotics, antifungals, antiparasitics, immune modulators, and anti-inflammatory agents.

View Article and Find Full Text PDF

Carcinogenesis encompasses processes that lead to increased mutation rates, enhanced cellular division (tumour growth), and invasive growth. Colorectal cancer (CRC) carcinogenesis in carriers of pathogenic APC (path_APC) and pathogenic mismatch repair gene (path_MMR) variants is initiated by a second hit affecting the corresponding wild-type allele. In path_APC carriers, second hits result in the development of multiple adenomas, with CRC typically emerging after an additional 20 years.

View Article and Find Full Text PDF

Background: Individuals with cystic fibrosis (CF; a recessive disorder) have an increased risk of colorectal cancer (CRC). Evidence suggests individuals with a single CFTR variant may also have increased CRC risk.

Methods: Using population-based studies (GECCO, CORECT, CCFR, and ARIC; 53 785 CRC cases and 58 010 controls), we tested for an association between the most common CFTR variant (Phe508del) and CRC risk.

View Article and Find Full Text PDF

Background: Colorectal cancers (CRCs) from people with biallelic germline likely pathogenic/pathogenic variants in MUTYH or NTHL1 exhibit specific single base substitution (SBS) mutational signatures, namely combined SBS18 and SBS36 (SBS18+SBS36), and SBS30, respectively. The aim was to determine if adenomas from biallelic cases demonstrated these mutational signatures at diagnostic levels.

Methods: Whole-exome sequencing of FFPE tissue and matched blood-derived DNA was performed on 9 adenomas and 15 CRCs from 13 biallelic MUTYH cases, on 7 adenomas and 2 CRCs from 5 biallelic NTHL1 cases and on 27 adenomas and 26 CRCs from 46 non-hereditary (sporadic) participants.

View Article and Find Full Text PDF

Background: Discussing Advance Care Planning (ACP) with people living with dementia (PwD) is challenging due to topic sensitivity, fluctuating mental capacity and symptom of forgetfulness. Given communication difficulties, the preferences and expectations expressed in any ACP may reflect family and healthcare professional perspectives rather than the PwD. Starting discussions early in the disease trajectory may avoid this, but many PwD may not be ready at this point for such discussions.

View Article and Find Full Text PDF

Background: Microsatellite instability-high (MSI-high) tumors comprise ~15% of sporadic colorectal cancers (CRC) and are associated with elevated T cell infiltration. However, the universality of this response across T cell subtypes with distinct functions is unknown.

Methods: Including 1,236 CRC tumors from three observational studies, we conducted T cell profiling using a customized 9-plex (CD3, CD4, CD8, CD45RA, CD45RO, FOXP3, KRT, MKI67, and DAPI) multispectral immunofluorescence assay.

View Article and Find Full Text PDF

Menopausal users of hormone replacement therapy (HRT) are at increased breast cancer risk and decreased colorectal cancer (CRC) risk compared with individuals who have never used HRT, but these opposing associations may differ by familial risk of breast cancer and CRC. We harmonized data from 3 cohorts and generated separate breast cancer and CRC familial risk scores based on cancer family history. We defined moderate or strong family history as a risk score of 0.

View Article and Find Full Text PDF

Advancement of AI has opened new possibility for accurate diagnosis and prognosis using digital histopathology slides which not only saves hours of expert effort but also makes the estimation more standardized and accurate. However, preserving the AI model performance on the external sites is an extremely challenging problem in the histopathology domain which is primarily due to the difference in data acquisition and/or sampling bias. Although, AI models can also learn spurious correlation, they provide unequal performance across validation population.

View Article and Find Full Text PDF

Stanford Neuromodulation Therapy (SNT), has recently shown rapid efficacy in difficult to treat (DTT) depression. We conducted an exploratory analysis of individual symptom improvements during treatment, correlated with fMRI, to investigate this rapid improvement in 23 DTT participants from an SNT RCT (12 active, 11 sham). Montgomery-Åsberg Depression Rating Scale item 7 (Lassitude) was the earliest to show improvements between active and sham, as early as treatment day 2.

View Article and Find Full Text PDF
Article Synopsis
  • * A study identified a specific genetic variation at Chr6:31373718C>G that is associated with increased CRC risk, particularly in the younger population, with stronger odds for EOCRC compared to older adults.
  • * Analysis showed that individuals carrying the minor G allele have reduced expression of the immune-related MICA gene and lower levels of Natural Killer (NK) cell infiltration in tumors, suggesting a link between this genetic variation and tumor immune response.
View Article and Find Full Text PDF
Article Synopsis
  • Research explored the link between calcium intake, genetic variants in the calcium sensor receptor gene, and survival rates in colorectal cancer (CRC) patients, using data from 18,952 individuals.
  • No significant associations were found between dietary, supplemental, or total calcium intake and either all-cause or CRC-specific mortality, despite tracking 6,801 deaths over a median follow-up of 4.8 years.
  • The study noted potential interactions between supplemental calcium intake and certain genetic variants, suggesting that genetics may influence how calcium affects mortality in CRC patients.
View Article and Find Full Text PDF

Decades of neuroimaging studies have shown modest differences in brain structure and connectivity in depression, hindering mechanistic insights or the identification of risk factors for disease onset. Furthermore, whereas depression is episodic, few longitudinal neuroimaging studies exist, limiting understanding of mechanisms that drive mood-state transitions. The emerging field of precision functional mapping has used densely sampled longitudinal neuroimaging data to show behaviourally meaningful differences in brain network topography and connectivity between and in healthy individuals, but this approach has not been applied in depression.

View Article and Find Full Text PDF
Article Synopsis
  • Colorectal cancers (CRCs) linked to biallelic germline variants show specific mutational signatures (SBS18+SBS36 and SBS30) that could also be present in adenomas, which are precursors to CRCs.
  • A study sequenced DNA from adenomas and CRCs in biallelic cases and compared them with sporadic cases to investigate these signatures.
  • Results indicated that adenomas in biallelic cases had similar mutational signature proportions as their corresponding CRCs, suggesting testing adenomas could enhance the detection of biallelic cases and improve variant classification for better CRC prevention strategies.
View Article and Find Full Text PDF
Article Synopsis
  • Folate intake plays a crucial role in genetic and metabolic processes, and low levels are linked to higher cancer risk, specifically colorectal cancer (CRC).
  • The study analyzed dietary and supplemental folate intake among participants with CRC, investigating how this intake relates to specific genetic mutations using advanced sequencing techniques.
  • Results indicated that higher total folate intake generally reduced CRC risk, but the impact varied when considering mutation status in tumors, with a few specific gene mutations showing different associations with folate intake.
View Article and Find Full Text PDF
Article Synopsis
  • * rTMS is a safe and effective noninvasive treatment that has improved through recent algorithm optimizations, making it more accessible and affordable.
  • * The authors advocate for rTMS to be considered a first-line treatment for major depressive episodes due to its comparable efficacy and side effects relative to traditional therapies like psychotherapy and SSRIs, yet emphasize the need for more research for better validation.
View Article and Find Full Text PDF
Article Synopsis
  • * Researchers analyzed data from 52 studies, including nearly 31,000 CRC cases and over 41,000 controls, to explore the genetic interactions with regular aspirin/NSAID use.
  • * They found significant interactions with genetic variants in two specific regions (6q24.1 and 5p13.1), which could help uncover new targets for understanding how aspirin provides its protective effects against colorectal cancer.
View Article and Find Full Text PDF
Article Synopsis
  • Long-duration spaceflights are increasing but may pose risks to brain health, affecting performance and well-being.
  • Transcranial magnetic stimulation (TMS) shows promise in reducing behavioral and cognitive risks for astronauts during these missions.
  • The text discusses Earth-based TMS applications, its advantages over existing treatments, and the challenges of implementing this technology in space.
View Article and Find Full Text PDF
Article Synopsis
  • Consumption of fiber, fruits, and vegetables may lower the risk of colorectal cancer (CRC), but genetic factors might influence this connection.
  • A large study involving nearly 70,000 participants identified two significant genetic variants linked to dietary intake and CRC risk using advanced statistical methods.
  • The findings suggest specific genetic loci (SLC26A3 and NEGR1) may affect how fiber and fruit consumption interacts with CRC risk, highlighting the need for more research on the underlying mechanisms.
View Article and Find Full Text PDF
Article Synopsis
  • A deep learning algorithm called QuantCRC analyzes tumor morphologic features in stage III colon cancer to improve patient risk assessment based on DNA mismatch repair (MMR) status.
  • The study found significant differences in tumor features between deficient (d-MMR) and proficient (p-MMR) tumors, impacting prognosis and recurrence rates.
  • Results suggest that QuantCRC can effectively identify prognostic markers in routine tumor sections, potentially advancing understanding of cancer pathology and patient outcomes.
View Article and Find Full Text PDF
Article Synopsis
  • Survivors of colorectal cancer are at risk for developing a second primary colorectal cancer, termed metachronous colorectal cancer, and identifying features of the first tumor could help improve surveillance strategies.
  • In a study of 6085 colorectal cancer cases from the Colon Cancer Family Registry, 138 (2.3%) developed metachronous CRC over an average follow-up of 12 years, with specific factors influencing their risk.
  • Notably, individuals with synchronous tumors were 3.4 times more likely, and those with MMR-deficient tumors had a 72% higher risk, while those with an undifferentiated histologic type were 77% less likely to develop a second cancer. Existing surveillance guidelines may need
View Article and Find Full Text PDF

Genome-wide association studies (GWAS) have identified more than 200 common genetic variants independently associated with colorectal cancer (CRC) risk, but the causal variants and target genes are mostly unknown. We sought to fine-map all known CRC risk loci using GWAS data from 100,204 cases and 154,587 controls of East Asian and European ancestry. Our stepwise conditional analyses revealed 238 independent association signals of CRC risk, each with a set of credible causal variants (CCVs), of which 28 signals had a single CCV.

View Article and Find Full Text PDF

Globally, lung cancer is the leading cause of cancer death. Previous trials demonstrated that low-dose computed tomography lung cancer screening of high-risk individuals can reduce lung cancer mortality by 20% or more. Lung cancer screening has been approved by major guidelines in the United States, and over 4,000 sites offer screening.

View Article and Find Full Text PDF