Background: Hematological parameters derived from complete blood count (CBC) are inexpensive and widely available markers with potential utility in risk stratification of acute coronary syndrome (ACS). However, their incremental prognostic value when used alongside contemporary risk stratification tools such as the Troponin-only Manchester Acute Coronary Syndrome (T-MACS) score remains unclear. Methods: In this prospective, single-center cohort study, 521 patients presenting with non-ST-segment elevation myocardial infarction (NSTEMI) or unstable angina were enrolled. Admission CBC parameters (white blood cell count, neutrophils, monocytes, red cell distribution width, mean platelet volume) and derived inflammatory indices (neutrophil-to-lymphocyte ratio, white blood cell-to-mean platelet volume ratio, lymphocyte-to-monocyte ratio, mean platelet volume-to-platelet ratio, and red cell distribution width-to-platelet ratio) were recorded. T-MACS risk scores were calculated, and patients were followed for 30-day major adverse cardiac events (MACE), mortality, and coronary interventions. Associations were assessed using univariate and multivariate logistic regression analyses. Results: Patients experiencing 30-day MACE or mortality had significantly higher white blood cell counts, neutrophil counts, and WMR values (all p < 0.05). Several hematological indices showed significant associations with T-MACS risk categories. In multivariate analysis, intermediate- and high-risk T-MACS classifications independently predicted 30-day MACE (OR 4.49, 95% CI:1.46-13.77, p = 0.009; OR 9.34, 95% CI:3.00-29.03, p < 0.001, respectively), whereas white blood cell count, neutrophil count, and WMR did not demonstrate independent prognostic value beyond T-MACS classification. Conclusions: Admission white blood cell count, neutrophil count, and WMR are associated with short-term adverse outcomes and T-MACS risk severity in patients with NSTE-ACS. However, these markers do not provide additional prognostic value beyond T-MACS classification. These findings suggest that CBC-derived inflammatory markers primarily reflect disease severity rather than incremental prognostic information in the contemporary high-sensitivity troponin era.
Adrenal incidentalomas (AIs) are frequently discovered during imaging performed for unrelated conditions. While most are benign and non-functional, a subset demonstrates hormonal activity or malignant potential. This study aimed to describe the clinical and radiological characteristics, natural history and predictors of mild autonomous cortisol secretion (MACS) in a Malaysian cohort. This retrospective multicentre study reviewed medical records of 251 patients with AIs from three tertiary hospitals in Malaysia. Data on demographics, imaging findings, hormonal evaluations, histopathological diagnoses and longitudinal follow-up, including serial imaging and hormonal assessments, were collected and analysed. The median age of the cohort was 58 years (IQR 19), with a slight female predominance (53%). The population was predominantly Malay (n = 126, 50.2%), followed by Chinese (36.3%) and Indian (12.7%). The median follow-up duration was 39 months.Most AIs were non-malignant (92%) and non-functioning (72%). Bilateral lesions were present in 9.6% of patients. Among non-malignant AIs, 27% were functioning, with higher rates of hypertension and osteoporosis, larger tumour size and greater tumour density. Adrenalectomy was more commonly performed in the functioning group, mainly for MACS and pheochromocytoma. In contrast, 94% of benign non-functioning AIs were managed conservatively, with no cases of malignant transformation and only one case developing hormonal activity over a median follow-up of 30 months. Among the 20 malignant AIs, 12 were primary adrenal carcinomas. Malignant AIs were associated with larger size, overt Cushing's syndrome, higher Hounsfield units, lower contrast washout and increased mortality.MACS was identified in 12.7% of the cohort. It was associated with bilateral lesions, larger tumour size, and higher prevalence of diabetes, dyslipidaemia, obesity and osteoporosis. On multivariate analysis, only bilaterality and osteoporosis remained significant predictors of MACS. This study reinforces that most benign non-functioning AIs carry minimal risk of progression, supporting less intensive follow-up in stable cases. Bilaterality and osteoporosis were identified as independent predictors of MACS, emphasizing the importance of targeted hormonal and bone health monitoring in these patients.
Astrocytic homeostatic programs, many of which are regulated by the circadian clock, are disrupted early in neurodegenerative disease. The core clock transcription factor (TF) BMAL1 is required for normal astrocyte function, but its role during disease remains unclear. This is partly because methods for identifying cell type-specific TF binding sites are limited. Here, we developed MACS-Calling Cards (MACS-CC), a strategy for mapping astrocyte-specific TF occupancy in vivo. We used MACS-CC to define BMAL1 binding in the Cln3 Δex7/8 mouse model of CLN3 disease, a fatal neurodegenerative disorder marked by early astrocyte dysfunction and circadian disruption. BMAL1 binding was extensively redistributed in Cln3 Δex7/8 astrocytes: wild-type-specific binding sites enriched near glial differentiation genes, whereas Cln3 Δex7/8 -specific sites lacked functional enrichment. Consistent with these changes, Cln3 Δex7/8 astrocytes decreased expression of mature astrocyte markers. To define mechanisms underlying BMAL1 retargeting, we tested whether altered chromatin accessibility explained the changes in BMAL1 binding. Although chromatin accessibility was broadly remodeled, differential accessibility did not predict BMAL1 redistribution. Instead, motif analysis suggested that loss of cooperative TF interactions drives BMAL1 retargeting. These findings demonstrate that MACS-CC enables astrocyte-specific TF occupancy mapping and reveals mechanisms behind early rewiring of circadian regulatory programs within a model of a neurodegenerative disease.
Chronic kidney disease (CKD) affects over 37 million adults in the United States, and people living with HIV (PLWH) are at greater risk for progression to end-stage kidney disease. Although both conditions are common among PLWH, the potential pathways through which depression and use of medications with nephrotoxic potential may influence CKD development remain underexplored. We evaluated the relationships of depression and nephrotoxic medication use with CKD prevalence among PLWH, and investigated the potential mediating effects of these factors on the pathway to CKD among PLWH. We analyzed data from the Multicenter AIDS Cohort Study (MACS)/Women's Interagency HIV Study (WIHS) Combined Cohort Study (MWCCS). Baseline CKD prevalence was estimated using Visit 101 only (November 2020-September 2021). To examine associations with CKD over time, we fit generalized estimating equations (GEE) using repeated observations from Visits 101-103 (November 2020-March 30, 2023) with a Poisson distribution and log link to estimate relative risks (RR) and account for within-participant correlation. Counterfactual-based causal mediation analyses were conducted using Visit 101-103 data to evaluate whether elevated depressive symptoms (CES-D ≥ 16) or nephrotoxic medication use mediated the HIV-CKD association while adjusting for baseline confounders. Among 2,530 participants [1,622 PLWH and 908 people living without HIV (PLWoH)], CKD prevalence was higher in PLWH (18.1%) compared to PLWoH (9.7%). In univariate repeated-measures GEE models, HIV serostatus (RR = 1.37, 95% CI: 1.28-1.48, p < 0.0001) and Nephrotoxic medication use (RR = 1.49, 95% CI: 1.30-1.71, p < 0.0001) were significantly associated with higher CKD risk. Several covariates were also associated with CKD in univariate GEE models, including age (RR = 1.03, 95% CI: 1.03-1.03, p < 0.0001), non-Hispanic Black (RR = 1.19, 95% CI: 1.11-1.27, p < 0.0001) compared to non-Hispanic White, diabetes (RR = 1.26, 95% CI: 1.17-1.35, p < 0.0001), and higher income (RR = 0.99, 95% CI: 0.98-1.00, p = 0.005). Depressive symptoms were not associated with CKD in mediation-model adjusted analyses and did not mediate the HIV-CKD association. Mediation analysis indicated that nephrotoxic medication use accounted for a small but significant proportion of the HIV-CKD association (indirect effect OR = 1.02, 95% CI: 1.00-1.03, p = 0.02). While it is well established that PLWH have a higher prevalence of CKD compared to PLWoH, our findings suggest that nephrotoxic medication use may modestly amplify this risk. Although most of the risk appears to be attributable to the direct effects of HIV, these medications represent a modifiable contributor. PLWH receiving such treatments may benefit from closer kidney function monitoring. Future research should evaluate psychosocial contributors to CKD using designs that incorporate clinical depression diagnosis and treatment data to clarify depression-related pathways.
Oral diseases are prevalent and linked to systemic health outcomes. People with HIV may face elevated oral disease risk, yet data on dental disease in this population remain limited. In this cross-sectional study, we analyzed oral health data collected from 2927 participants in the MACS/WIHS Combined Cohort Study (968 women with HIV [WWH], 450 women without HIV [WWoH], 941 men with HIV [MWH], 568 men without HIV [MWoH]) who had intraoral photographs collected and evaluated by dentist-researchers. We used log-binomial regression to examine associations between demographic and clinical characteristics and two outcomes: missing teeth and untreated caries or residual roots, stratified by sex. Among 2927 participants (median [interquartile range, IQR] age: WWH, 55.3 years [48.3-61.6]; WWoH, 53.3 [44.8-60.3]; MWH, 55.1 [42.6-62.9]; MWoH, 62.9 [50.1-69.5]), women experienced a higher prevalence of tooth loss and untreated decay than men. Among participants aged 65 years or older, 15% to 21% of women were edentulous (compared with 2% to 3% of men), and 30% to 31% were missing at least a full arch of teeth (compared with 4% to 6% of men). In multivariable analyses, age was a dominant predictor of missing teeth among men (age ≥ 65 vs. <45 years: adjusted prevalence ratio [aPR], 1.49; 95% confidence interval [CI], 1.29-1.73). Income was the strongest predictor of untreated decay among women, more strongly predictive than age (highest vs. lowest income: aPR, 0.11; 95% CI, 0.03-0.43). Disparities by race/ethnicity persisted among men but were absent among women, who experienced extreme poverty and poor outcomes regardless of race/ethnicity. HIV serostatus was not independently associated with either outcome. Dental disease burden in this population reflected socioeconomic disparities rather than HIV infection. Racial disparities were absent among women, who had uniformly low incomes and poor oral health outcomes across all groups, highlighting substantial barriers to dental care access that warrant policy attention.
To analyze if there are differences in the urinary steroid profile before and after cosyntropin stimulation and in the surgical outcomes between patients with primary aldosteronism (PA) with associated mild autonomous secretion of cortisol (MACS) (MACS-PA) and those without it (only PA). We conducted a prospective, multicenter study of patients consecutively diagnosed with PA in whom a 24-hour urine collection was performed to measure 33 urinary steroid metabolites levels before and after 250 μg intravenous cosyntropin. MACS was defined by the presence of cortisol after a 1 mg-dexamethasone suppression test >1.8 μg/dL and confirmed adrenocorticotropic hormone (ACTH) independency. Fifty-three patients with PA were included in the study: 15 with MACS-PA and 38 with only PA. Baseline characteristics of both groups were similar, except for higher levels of A1C levels in the first group (P = .034). The baseline urinary steroid profile showed higher levels of β-cortol and β-cortolone in patients with MACS-PA than in those with only PA, and after ACTH stimulation, patients with MACS-PA had a lower increase of glucocorticoids excretion than patients without MACS including α-cortol and 11β-OH-androsterone. Some metabolites even experienced a decrease in their levels after ACTH stimulation (tetrahydrocortisone, α-cortolone, and β-cortolone). Patients with MACS-PA experienced a lower postsurgical decrease in systolic and diastolic blood pressure than in patients with only PA. Patients with MACS-PA exhibited a higher excretion of glucocorticoid metabolites and a lower response to ACTH than patients with PA without associated MACS. Patients with MACS-PA experience a lower quantitative improvement in systolic and diastolic blood pressure after adrenalectomy than patients with only PA.
Mild autonomous cortisol secretion (MACS) leads to the clustered manifestations of hypertension (HT), diabetes, and metabolic syndromes. However, whether the effect of MACS on myocardial remodeling and cardiac function is similar to that of Cushing's syndrome remains unclear. This study aimed to compare the metabolic risks and impact on cardiac structure and function between MACS and Cushing's syndrome. This retrospective study evaluated patients with nonfunctioning adrenal tumors (NFAT), MACS, and Cushing's syndrome. Metabolic parameters and cardiac structure/function indices were compared among the groups. Overall, 208 patients with NFAT ( n  = 20), MACS ( n  = 108), and Cushing's syndrome ( n  = 80) were included. HT, diabetes, and metabolic syndrome were significantly more prevalent in the MACS group than in the NFAT group. Compared with the NFAT group, the MACS group showed significantly higher left ventricular mass index (LVMI) ( P  = 0.011) and rates of pathological LVMI elevation ( P  = 0.025). LVMI was significantly higher in both the MACS ( P  = 0.002) and Cushing's groups ( P  < 0.001) than in the NFAT group. Meanwhile, the metabolic parameters and LVMI were not significantly different between the MACS and Cushing's groups. Autonomous cortisol secretion (ACS), including MACS, is associated with higher metabolic risk and LVMI than is NFAT. The metabolic risk and LVMI elevation in MACS are comparable to those in Cushing's syndrome. Hence, all patients with ACS require clinical attention, regardless of the clinical manifestations.
Adrenal incidentalomas are an increasing clinical concern and, while most are non-functioning adrenal adenomas (NFAA), a relevant subset is associated with mild autonomous cortisol secretion (MACS), condition linked to various comorbidities, including metabolic and musculoskeletal alterations. However, the association with a reduction in muscle strength and mass is still controversial. We evaluated the effects of mild cortisol excess on skeletal muscle health, body composition, and quality of life (QoL) in patients with adrenal incidentalomas associated with MACS, compared with those with NFAA and healthy controls. Sixty-two participants were enrolled: 21 with MACS, 21 with NFAA, and 20 healthy controls. Skeletal muscle strength was assessed using handgrip dynamometry, the sit-to-stand test, and the Medical Research Council (MRC) scale. Body composition was analyzed by bioelectrical impedance analysis (BIA), and quality of life was assessed using the EQ-5D and SARC-F questionnaires. Patients with MACS had a significantly higher prevalence of osteopenia and osteoporosis compared to NFAA and controls (61.9% vs. 28.6% and 25%, respectively; p= 0.03). No significant differences were observed in fat-free mass (FFM), muscle mass (MM), or fat mass (FM) among groups. MACS patients showed significantly reduced MRC scores for biceps and quadriceps compared to controls (p=0.04). Patients with osteoporosis/osteopenia and reduced muscle strength exhibited higher post-dexamethasone suppression test (DST) cortisol concentrations although not significant. Similarly, QoL scores showed a trend toward greater impairment in the MACS group. It's one of the first studies assessing muscle mass and performance in MACS compared to NFAA and healthy controls. Our results underline the impact of mild hypercortisolism on proximal myopathy, suggesting an under-recognized musculoskeletal impact supporting the clinical relevance of MACS.
This study aimed to evaluate the relationship between mild autonomous cortisol secretion (MACS) caused by adrenal adenomas and hepatic fat fraction (HFF) measured by dual-echo Dixon chemical shift-encoded MRI (dual-echo CSE-MRI). This retrospective study included 151 patients with 169 adrenal adenomas evaluated between November 2023 and November 2025. According to post-1 mg dexamethasone suppression test (DST) cortisol levels, patients were classified as having MACS or non-functioning adrenal incidentalomas (NFAI). HFF was quantitatively assessed using dual-echo CSE-MRI. Clinical, biochemical, and imaging findings were analyzed. Correlation analyses and multivariate regression models were used to identify factors associated with hepatic fat fraction and MACS. Forty-five adrenal adenomas (26.6%) were classified as MACS. HFF was significantly higher in patients with MACS compared with those with NFAI (16.0% ± 13.3% vs. 7.1% ± 7.6%, p < 0.001). HFF showed a significant positive correlation with post-DST cortisol levels (r = 0.316, p < 0.001) and fasting glucose levels (r = 0.312, p < 0.001). In multivariate logistic regression analysis, hepatic fat fraction remained independently associated with MACS (OR: 1.084, p < 0.001). Multivariate linear regression analysis demonstrated that post-DST cortisol levels, fasting glucose levels, and age were independently associated with HFF. Hepatic fat fraction measured by dual-echo CSE-MRI is increased in patients with MACS and is associated with cortisol excess.
Autologous chimeric antigen receptor (CAR) expressing T-Cells (CAR-T) have been efficiently used in hematological malignancies but their efficacy in solid tumors remains limited. CAR therapies via the use of macrophages, offer a promising avenue due to their unique ability to infiltrate tumors and to initiate phagocytosis. To generate a preclinical model of CAR-Macs, we have designed a novel CAR-construct to target EGFRVIII-expressing glioblastoma cells (DK-MG) using THP-1 monocytic cell line able to differentiate towards macrophages. The CAR structure comprises a ScFv recognizing specifically EGFRVIII and MEGF10 intracellular domain which enhances tethering and phagocytosis activity. THP-1 cell line expressing CAR and control constructs were generated via lentiviral transduction followed by generation of monocytes and CAR-expressing M1 macrophages (CAR-Macs). To evaluate their ability of phagocytosis, we co-cultured THP-1 derived WT macrophages or CAR-Macs in the presence of target DK-MG cells. Confocal microscopy experiments revealed highly efficient phagocytosis of DK-MG EGFRVIII cells by CAR-Macs (~ 60%) as compared to WT cells (~ 15%). The killing potential of the anti-EGFRVIII CAR-Macs against the glioblastoma cell line has also been observed using video microscopy. ELISA and LDH assays performed in co-culture supernatants, showed an increase of IL-6 and LDH levels suggesting efficient cytotoxicity via CAR-Macs. Transcriptome analyses performed in purified CAR-Macs, revealed evidence of a molecular signature in favor of successful phagocytosis. The model described in this work is suitable for allowing translation to iPSC-derived macrophages to generate clinically applicable future cell therapy approaches in solid tumors expressing mutated variant EGFRVIII.
Mild autonomous cortisol secretion (MACS) has an increasing prevalence with age and is associated with cardiometabolic comorbidity and increased mortality. Current guidelines recommend the majority of patients with MACS be managed conservatively, with select people referred for laparoscopic adrenalectomy. There are currently no licensed medications for MACS. We aimed to systematically review the literature to map out the current available evidence on the use of medical therapy in the treatment of MACS and to assess the research gap. Additionally, we sought to establish the outcome measurements used, to inform the design of future prospective clinical trials. We searched MEDLINE and EMBASE from conception as well as clinical trial registries to detect all original studies of medical treatments in MACS. Titles and abstracts were screened and full articles reviewed. A total of 5369 results were found from the search strategy. Thirteen studies met the inclusion criteria, of which 8 were conference abstracts and 5 full-text studies were included in the final analysis. This included 2 studies of metyrapone and 3 studies that used mifepristone. Common outcome measures included blood pressure, glucose measurements, weight, and side effect data. There is a considerable knowledge gap with regard to the medical management of MACS. Current available evidence consists of a handful of small, heterogeneous studies with a suggestion of a potential benefit in initiating mifepristone or metyrapone in this cohort. Our results highlight the urgent need for larger, prospective studies. To support this, we have provided suggestions for outcome measures.
Alcohol use disorder (AUD) is a chronic relapsing disorder with high early rehospitalization rates. Valid instruments assessing dependence severity, craving, and relapse risk are fundamental for follow-up. The aim of this study was to examine the psychometric properties of the Hungarian Severity of Alcohol Dependence Questionnaire (SADQ), Multidimensional Alcohol Craving Scale (MACS), Penn Alcohol Craving Scale (PACS) and Alcohol Relapse Risk Scale (ARRS), and test their utility in predicting relapse risk and rehospitalization. Ninety-three AUD inpatients were assessed on hospitalization day 8 with SADQ, AUDIT, MACS, PACS, visual analogue scale (VAS) of craving and ARRS, and followed for 3 months. Internal consistency and concurrent validity were evaluated. We tested whether SADQ and ARRS predicted 3-month rehospitalization (logistic regressions), whether MACS and PACS predicted relapse risk (linear regression). The 3-month rehospitalization rate was 21.5%. All scales showed high internal consistency (α = 0.86-0.94) and concurrent validity. After item reduction based on item-total correlations, the 27-item ARRS (ARRS-27) showed higher internal consistency, and predicted rehospitalization (OR = 1.12, 95% CI: 1.05-1.18; p < 0.001). Higher SADQ scores predicted rehospitalization (OR = 1.05, 95% CI: 1.02-1.09; p = 0.007). MACS (p < 0.001) and PACS (p = 0.046) scores predicted ARRS scores (R2 = 0.53), with MACS showing the stronger effect. Based on our preliminary results, the Hungarian SADQ, MACS, PACS, and ARRS-27 are reliable instruments with predictive value for relapse risk and rehospitalization in AUD. Their combined use might support a treatment and relapse-prevention algorithm, improving clinical care and guiding future research.
Midair collisions (MACs), while rare for air carriers, are not infrequent for general aviation, partly reflecting the limitations of the see-and-avoid method. However, considering technological advances potentially offsetting ocular limitations and little research on the subject, we sought to determine 1) whether the MAC rate has declined over time and 2) the underlying causes. MACs' (1995-2023) injury severity, mission type, and ambient conditions were per the National Transportation Safety Board database. Statistics used Poisson distributions/Chi-square tests. There were 480 aircraft (90% and 8% fixed-/rotary-wing aircraft, respectively) involved in 257 midair events. Despite an overall decline (63% reduction) in MAC rates (2020-2023), the proportion of fatal events (44-58%) was unchanged. Aircraft engaged in personal and training missions represented 61% and 24% of MACs, respectively, with the training mission MAC rate declining 70%. Although traffic density is highest surrounding aerodromes, surprisingly, only half of the MACs were within this environment. MAC rates, adjusted for arrival/departure counts, at aerodromes with a control tower were 6.5-fold lower compared with airports lacking such a facility. However, some MACs were still evident for aircraft receiving traffic deconfliction services, and for such mishaps, 78% were due to pilots not maintaining visual separation. The following recommendations are advanced. General aviation authorities and organizations should update pilot training curricula and safety programs to include training on physiological limitations, e.g. field of vision deterioration with advancing age. Further, the findings herein warrant future research to determine whether over-reliance on electronic traffic displays and panel modernization negatively impact external visual scanning. Boyd D, Anderson C. Midair collisions over a period of technological advances targeting human performance deficits. Aerosp Med Hum Perform. 2026; 97(6):443-450.
Minimal access cardiac surgery (MACS) can mitigate the increasing risk profile of cardiac surgery patients and is associated with improved postoperative outcomes. One of the ways to manage the steep learning curve of MACS is the use of surgical simulation training. We conducted a narrative review to identify the relevant literature discussing MACS simulation training. We identified 20 studies using our search strategy. Various platforms were represented: high-fidelity (n = 8), low-fidelity (n = 6), and animal studies (n = 6). Virtual reality (VR) appeared in two wet-lab studies as an adjunct. The surgical approach was video-assisted thoracoscopic surgery (VATS) in 11 and robotic-assisted thoracoscopic surgery (RATS) in nine. The most simulated procedure was minimal access mitral valve (MV) repair (n = 16). Most studies (n = 16) evaluated the impact of simulation training on the surgical skill of participants with varying baseline MACS experience. A small proportion of included studies (n = 4) carried out only fidelity testing. While some standardised assessment tools were used, there was considerable variation in how surgical skill and fidelity were assessed. There are an increasing number of publications on MACS simulation training, with equal focus on bench and animal models. MV procedures were the most simulated, suggesting a drive towards increasing the scope of minimal access MV training.
FACS-based CRISPR screening has emerged as a potent tool for dissecting the genetic networks that regulate cell-surface glycosylation. However, existing protocols can be tedious and are not compatible with many cell models. We developed a lectin-based magnetic-activated cell sorting platform (Lec-MACS) that enables rapid identification of genes controlling expression of specific cell-surface glycans. Lec-MACS offers superior speed and multiplexability compared to FACS, while also being well-suited to studying cell models that are not amenable to flow-based sorting. We subsequently applied Lec-MACS to map genes that regulate hypersialylation in an adherent breast cancer cell line. Subsequent hit validation confirmed an unexpected link between DNA damage response signaling and cell-surface sialylation. The Lec-MACS method will expand the scope and throughput of genetic screens targeted at cell-surface glycans.
Disruption of the circadian glucocorticoid rhythm occurs in human settings including chronic stress, sleep restriction, circadian misalignment, ageing and autonomous cortisol secretion; in mild autonomous cortisol secretion (MACS) and Cushing's syndrome, loss of the normal cortisol trough is clinically informative, and flatter diurnal cortisol profiles are associated with cardiometabolic disease. We previously showed that flattening of glucocorticoid rhythms in mice induces rapid and sustained hyperinsulinemia without hyper or hypo-glycaemia, implying that glucocorticoid rhythms may directly regulate the relationship between circulating glucose and systemic insulin output. Here we tested the hypothesis that beta cell glucocorticoid receptor (GR) signalling is required for the compensatory hyperinsulinaemia that maintains glucose homeostasis during glucocorticoid rhythm flattening, and that this reflects glucocorticoid-dependent reprogramming of beta cell stimulus-secretion coupling. Glucocorticoid rhythms were flattened in male C57BL/6J mice by subcutaneous corticosterone pellet implantation, which elevates trough levels and reduces peak amplitude while preserving the daily mean hormone concentration. Fasting plasma insulin and blood glucose were measured longitudinally and compared with placebo-implanted controls and high-fat diet-fed mice. Beta cell secretory function was assessed by static and dynamic glucose-stimulated insulin secretion in isolated islets, and beta cell excitability by GCaMP6f Ca²⁺ imaging in islets from Ins1-Cre;GCaMP6f mice. To test the requirement for beta cell GR in mature beta cells while avoiding developmental effects of constitutive GR deletion, we generated adult-inducible beta cell-specific GR knockout mice (MIP-CreERT;Nr3c1fl/fl; βGRKO). Combined beta cell and hepatic GR knockout mice (double-GRKO) were used to examine an additional extra-pancreatic contribution to systemic insulin availability. Glucose tolerance and insulin sensitivity were assessed by intraperitoneal glucose and insulin tolerance tests. As a secondary question, a possible contribution of altered insulin clearance was examined from plasma C-peptide:insulin ratios and hepatic insulin-degrading enzyme (IDE) abundance. Glucocorticoid rhythm flattening produced sustained hyperinsulinaemia with maintained euglycaemia, distinct from the delayed hyperinsulinaemia and hyperglycaemia observed in high-fat diet-fed mice. Islets from glucocorticoid-flattened mice exhibited increased insulin secretion at subthreshold (3 mmol/l) glucose, enhanced secretory responses to stimulatory glucose and increased Ca²⁺ responses, indicating a lowered glucose threshold for beta cell activation that persisted ex vivo. Beta cell-specific deletion of GR markedly attenuated the hyperinsulinaemic response to glucocorticoid flattening (insulin AUC reduced ∼40% vs controls; p < 0.001) and produced progressive hyperglycaemia and impaired glucose tolerance, despite unchanged or improved insulin sensitivity. A reduced plasma C-peptide:insulin molar ratio (p = 0.007) and decreased hepatic IDE abundance (p = 0.032) indicated that reduced insulin clearance contributes additionally to the elevated circulating insulin, and combined beta cell and hepatic GR deletion lowered circulating insulin further than beta cell GR deletion alone. The absence of hypoglycaemia despite persistent hyperinsulinaemia is consistent with concurrent insulin resistance. Beta cell GR signalling is required for the compensatory hyperinsulinaemia that maintains glucose homeostasis when glucocorticoid rhythmicity is disrupted, acting through glucocorticoid-dependent lowering of the glucose threshold for insulin secretion; reduced insulin clearance contributes additionally to the rise in circulating insulin. These findings identify beta cell GR signalling as a key determinant of glucose homeostasis during disrupted glucocorticoid rhythmicity. Clinically, the work is most relevant not simply to nonspecific chronic stress, but to human states in which the cortisol rhythm is measurably flattened or the nocturnal trough is lost, including MACS, Cushing's syndrome, sleep restriction, shift work/circadian misalignment and ageing. What is already known about this subject?: Flattened or disrupted glucocorticoid rhythmicity in humans is observed most directly in MACS and Cushing's syndrome, where loss of the late-night cortisol nadir is clinically informative, and more broadly as flatter salivary cortisol slopes or elevated evening cortisol in ageing, sleep restriction and circadian misalignment; these patterns are associated with type 2 diabetes, cardiovascular disease and mortality.Flattening of glucocorticoid rhythms in mice induces rapid and sustained hyperinsulinaemia without hypoglycaemia, indicating that circulating insulin can be elevated independently of glucose.Hepatic insulin clearance, mediated in part by insulin-degrading enzyme and CEACAM1, is a major determinant of circulating insulin levels.What is the key question?: How does disruption of glucocorticoid rhythmicity increase circulating insulin while maintaining glycaemic control, and is beta cell glucocorticoid receptor signalling required for this adaptive response?What are the new findings?: Glucocorticoid rhythm flattening lowers the glucose threshold for beta cell activation through enhanced Ca²⁺ excitability, an effect that persists in isolated islets and indicates in vivo reprogramming of beta cell function. Beta cell-specific deletion of the glucocorticoid receptor blunts the hyperinsulinaemic response to glucocorticoid flattening and produces hyperglycaemia and impaired glucose tolerance despite unchanged or improved insulin sensitivity.Reduced insulin clearance, associated with decreased hepatic insulin-degrading enzyme abundance, contributes additionally to the elevated circulating insulin, but is not required for maintenance of glucose homeostasis.How might this impact on clinical practice in the foreseeable future?: Identifying beta cell glucocorticoid receptor signalling as a requirement for glucose homeostasis during disrupted glucocorticoid rhythmicity may inform strategies for understanding hyperinsulinaemia and steroid-associated metabolic dysfunction in human conditions marked by loss of the cortisol trough or flatter diurnal cortisol profiles, particularly MACS, Cushing's syndrome, shift work/circadian misalignment and ageing.
Medical treatment of Cushing syndrome (CS) with steroidogenesis inhibitors or ACTH-directed agents is typically given using a titration strategy to achieve "normal" exposure to cortisol, as determined by a 24-hour urine free cortisol (UFC) measurement. This approach generally achieves similar serum cortisol levels across the day and fails to provide a normal diurnal pattern of cortisol. Chronotherapy addresses this problem through weighted afternoon/evening dosing of cortisol-lowering drugs. Additionally, because of day-to-day variability of cortisol production, patients may be undertreated on days of higher cortisol production and overtreated on days of lower cortisol production. A "block and replace" strategy is an alternative approach in which consistent biochemical glucocorticoid deficiency is the goal, with added glucocorticoid replacement to provide physiologic diurnal exposure to cortisol. Recently, the term mild autonomous cortisol secretion (MACS) has been used to describe patients without clinical features of CS who fail to suppress cortisol after 1 mg dexamethasone. MACS includes individuals with an adrenal mass(es) who may have hypertension, type 2 diabetes mellitus, and/or osteoporosis. The role of medical vs surgical treatment of MACS is currently debated. We here review the advantages and disadvantages of each approach to medical treatment of CS and MACS, concluding that "block and replace" deserves wider consideration, especially in patients who have severe disease, and to avoid adrenal insufficiency in those with highly variable UFC, or are taking agents that may cause adrenal insufficiency. Conversely, in those with mild disease, chronotherapy normalizes nighttime cortisol exposure while reducing drug burden.
The prognostic significance of mucinous colorectal adenocarcinoma (MAC) is controversial. Some studies report good outcomes relative to conventional colorectal adenocarcinoma (CRC) as is similarly described for MACs in, e.g., the breast, lung, pancreas and prostate. However, other studies refute this, proclaiming either no difference or worse outcomes. Herein, we proffer additional insights into the biology of MAC to explain these conflicting findings. A literature search was undertaken using keywords pertaining to MAC. Archival cases from our database were analyzed to provide context for our findings. The unifying histologic feature of MACs is their >50% content of extracellular mucin, but they should not be viewed as a monolithic entity, as is commonly portrayed in databases. Instead, MAC is a heterogenous disease as defined by histologic and molecular phenotypes. For example, MACs arising from adenoma-like CRC have relatively good outcomes unlike those from traditional serrated adenomas. Likewise, other factors such as histologic grade (grade 1-3), genomics (e.g., BRAF, KRAS, TP53), microsatellite instability (MSI-H, MSI-L), consensus molecular subtypes (CMS1-CMS4), and mucin types (MUC2, MUC5AC) significantly influence prognosis. These pathophysiologic features, demographics (age and sex) and specific anatomic regions/topography (right/left colon/rectum) can be captured and used to improve prognostic stratification. In contrast to previous studies that largely demarcated MAC as a discrete entity, this paper shows the limitations of this approach by highlighting the various sub-entities comprising MAC. Recognition of this heterogeneity may help to inform future treatment algorithms.
Glutathione conjugation is a key metabolic detoxification pathway, and its downstream products, mercapturic acid conjugates (MACs), may serve as urinary biomarkers of toxicant exposure. However, MAC profiling is hindered by incomplete filtering coverage and the lack of comprehensive spectral and structural databases. To address these limitations, we developed an analytical workflow integrating novel enzymatic deacetylation with ultrahigh-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS)-based neutral loss filtering. The aminoacylase-1-mediated deacetylation provides an orthogonal approach to detect MACs that lack the characteristic neutral loss of 129.0426 Da. Additionally, an in-house MAC library of 734,170 putative structures, combined with an in silico structure annotation tool, facilitated efficient MAC identification. The strategy was validated using 11 MAC standards spiked into urine and applied to urine samples from 15 participants before and after consuming deep-fried foods. A total of 847 features were mapped to at least one MAC structure, exceeding the ∼100 reported in previous studies, with 581 absent from the Human Metabolome Database (HMDB) or PubChem. Postconsumption, 59 MACs increased and 11 decreased, reflecting exposure-related shifts in reactive aldehydes, lipid oxidation products, acylcarnitines, and acyl-CoA intermediates. These findings demonstrate the utility of the workflow for capturing urinary MAC changes associated with deep-fried food consumption and for prioritizing candidate exposure indicators of reactive chemical species for future validation studies.