Targeting Acute Myeloid Leukemia Stem Cells Through Perturbation of Mitochondrial Calcium.

Acute myeloid leukemia stem cells (LSCs) are uniquely reliant on oxidative phosphorylation (OXPHOS) for survival. Moreover, maintenance of OXPHOS is dependent on BCL-2, creating a therapeutic opportunity to target LSCs using the BCL-2 inhibitor venetoclax. While venetoclax-based regimens have shown promising clinical activity, the emergence of drug resistance is prevalent. Thus, in the present study, we investigated how mitochondrial properties may influence venetoclax responsiveness. Our data show that utilization of mitochondrial calcium is fundamentally different between drug-responsive and non-responsive LSCs. By comparison, venetoclax-resistant LSCs demonstrate a more active metabolic (i.e. OXPHOS) status with relatively high levels of calcium. Consequently, we tested genetic and pharmacological approaches to target the mitochondrial calcium uniporter, MCU. We demonstrate that inhibition of calcium uptake reduces OXPHOS and leads to eradication of venetoclax-resistant LSCs. These findings demonstrate a central role for calcium signaling in LSCs and provide an avenue for clinical management of venetoclax resistance.

Serotype epidemiology and antibiotic resistance of pneumococcal isolates colonizing infants in Botswana (2016-2019).

BACKGROUND: In 2012, Botswana introduced 13-valent pneumococcal conjugate vaccine (PCV-13) to its childhood immunization program in a 3+0 schedule, achieving coverage rates of above 90% by 2014. In other settings, PCV introduction has been followed by an increase in carriage or disease caused by non-vaccine serotypes, including some serotypes with a high prevalence of antibiotic resistance. METHODS: We characterized the serotype epidemiology and antibiotic resistance of pneumococcal isolates cultured from nasopharyngeal samples collected from infants (≤12 months) in southeastern Botswana between 2016 and 2019. Capsular serotyping was performed using the Quellung reaction. E-tests were used to determine minimum inhibitory concentrations for common antibiotics. RESULTS: We cultured 264 pneumococcal isolates from samples collected from 150 infants. At the time of sample collection, 81% of infants had received at least one dose of PCV-13 and 53% had completed the three-dose series. PCV-13 serotypes accounted for 27% of isolates, with the most prevalent vaccine serotypes being 19F (n = 20, 8%), 19A (n = 16, 6%), and 6A (n = 10, 4%). The most frequently identified non-vaccine serotypes were 23B (n = 29, 11%), 21 (n = 12, 5%), and 16F (n = 11, 4%). Only three (1%) pneumococcal isolates were resistant to amoxicillin; however, we observed an increasing prevalence of penicillin resistance using the meningitis breakpoint (2016: 41%, 2019: 71%; Cochran-Armitage test for trend, p = 0.0003) and non-susceptibility to trimethoprim-sulfamethoxazole (2016: 55%, 2019: 79%; p = 0.04). Three (1%) isolates were multi-drug resistant. CONCLUSIONS: PCV-13 serotypes accounted for a substantial proportion of isolates colonizing infants in Botswana during a four-year period starting four years after vaccine introduction. A low prevalence of amoxicillin resistance supports its continued use as the first-line agent for non-meningeal pneumococcal infections. The observed increase in penicillin resistance at the meningitis breakpoint and the low prevalence of resistance to ceftriaxone supports use of third-generation cephalosporins for empirical treatment of suspected bacterial meningitis.

Evacuation and Health Care Outcomes Among Assisted Living Residents After Hurricane Irma.

Importance: Evacuation has been found to be associated with adverse outcomes among nursing home residents during hurricanes, but the outcomes for assisted living (AL) residents remain unknown. Objective: To examine the association between evacuation and health care outcomes (ie, emergency department visits, hospitalizations, mortality, and nursing home visits) among Florida AL residents exposed to Hurricane Irma. Design, Setting, and Participants: Retrospective cohort study using 2017 Medicare claims data. Participants were a cohort of Florida AL residents who were aged 65 years or older, enrolled in Medicare fee-for-service, and resided in 9-digit zip codes corresponding to US assisted living communities with 25 or more beds on September 10, 2017, the day of Hurricane Irma's landfall. Propensity score matching was used to match evacuated residents to those that sheltered-in-place based on resident and AL characteristics. Data were analyzed from September 2022 to February 2024. Exposure: Whether the AL community evacuated or sheltered-in-place before Hurricane Irma made landfall. Main Outcomes and Measures: Thirty- and 90-day emergency department visits, hospitalizations, mortality, and nursing home admissions. Results: The study cohort included 25 130 Florida AL residents (mean [SD] age 81 [9] years); 3402 (13.5%) evacuated and 21 728 (86.5%) did not evacuate. The evacuated group had 2223 women (65.3%), and the group that sheltered-in-place had 14 556 women (67.0%). In the evacuated group, 42 residents (1.2%) were Black, 93 (2.7%) were Hispanic, and 3225 (94.8%) were White. In the group that sheltered in place, 490 residents (2.3%) were Black, 707 (3.3%) were Hispanic, and 20 212 (93.0%) were White. After 1:4 propensity score matching, when compared with sheltering-in-place, evacuation was associated with a 16% greater odds of emergency department visits (adjusted odds ratio [AOR], 1.16; 95% CI, 1.01-1.33; P = .04) and 51% greater odds of nursing home visits (AOR, 1.51; 95% CI, 1.14-2.00; P = .01) within 30 days of Hurricane Irma's landfall. Hospitalization and mortality did not vary significantly by evacuation status within 30 or 90 days after the landfall date. Conclusions and Relevance: In this cohort study of Florida AL residents, there was an increased risk of nursing home and emergency department visits within 30 days of Hurricane Irma's landfall among residents from communities that evacuated before the storm when compared with residents from communities that sheltered-in-place. The stress and disruption caused by evacuation may yield poorer immediate health outcomes after a major storm for AL residents. Therefore, the potential benefits and harms of evacuating vs sheltering-in-place must be carefully considered when developing emergency planning and response.

Carotid Blood Flow as a Surrogate for Pulse Contour Analysis in Assessment of Fluid Responsiveness: A Prospective, Observational, Single-Centre Study (Contour Study).

Background and objectives The quest for an accurate and reliable non-invasive method of assessing cardiac output in critically ill patients is still ongoing. Carotid artery Doppler is a promising non-invasive, reproducible, and feasible bedside monitor. So we compared the change in cardiac output derived from arterial pressure waveforms (pulse contour analysis) with that from carotid artery Doppler-derived measurements, in post-major elective abdominal surgery patients. Materials and methods We conducted a prospective observational study in 30 adult post-major elective abdominal surgery patients admitted to the Gastroenterology and Liver Transplant intensive care unit postoperatively on mechanical ventilator support, who were found to be fluid responsive clinically on passive leg raise (PLR) test. Demographics and vasopressor support were recorded. Hemodynamic parameters including heart rate, systolic blood pressure (SBP), diastolic blood pressure (DBP), cardiac output (CO) using arterial pulse contour analysis (Vigileo monitor/FloTrac® sensor; Edwards Lifesciences, Irvine, California, United States), and carotid blood flow (CBF) were recorded on the baseline, pre- and post- PLR, and post fluid bolus administration. Balanced salt solution at the rate of 6ml/kg over 20 minutes was given as a fluid bolus. Results Of the 30 patients who were included in the study, 16 patients (53.3%) were on vasopressor support, mean (± SD) age of the patients was 52.93 (± 8.13) years. There was a significant increase in the SBP (mmHg) pre- to post-PLR, that is, 112.2±15.57 and 118.7±14.96, respectively (p-value = 0.001). Also from pre-PLR to post-fluid bolus administration, the increase in SBP was significant, 112.2±15.57 and 121.93±13.96, respectively (p-value = 0.001). The change in cardiac output measured using Vigileo and CBF from pre- to post-PLR (7.66±1.45 to 9.14±1.76, p< 0.001 for Vigileo and 8.10±1.66 to 9.72±1.99, p<0.001 for CBF) and pre-PLR to post fluid administration (7.66±1.45 to 9.39±1.77, p< 0.001 for Vigileo and 8.10±1.66 to 10.31±2.26, p< 0.001 for CBF) were significant. There was a positive correlation between the change in cardiac output as measured from arterial pulse contour analysis technique (Vigileo) and that measured from CBF (r=0.884) pre- and post-PLR. There was a significant correlation between cardiac output measurements derived from two techniques, before PLR, after PLR, and after fluid expansion (p< 0.001 for each variable). The change in cardiac output before PLR and after fluid expansion was also correlated by both the techniques (correlation coefficient being, r=0.781). Conclusion There was a significant positive correlation of the CO (absolute and change) measurements pre- and post-interventions (that is, PLR and fluid bolus administration) as made by pulse contour analysis (Vigileo) and by CBF in post-surgical patients. Pulse wave Doppler of CBF could be used as a surrogate for invasive measures of CO measurement for prediction of fluid responsiveness in this subgroup. Further larger studies can be performed to validate the same.

Provision of ambrisentan from a health-system specialty pharmacy affiliated with a pulmonary hypertension Center of Comprehensive Care.

PURPOSE: This descriptive report describes the process used to obtain access to providing ambrisentan from a health-system specialty pharmacy (HSSP) affiliated with a pulmonary hypertension Center of Comprehensive Care, develop a pulmonary arterial hypertension (PAH) care team at the HSSP, and characterize medication adherence and access metrics. SUMMARY: PAH is a rare disease treated with several specialty medications requiring intensive monitoring. Historically, specialty medications used to treat PAH have been provided by only select specialty pharmacies due to restricted drug distribution channels. It is recommended that patients with PAH receive their care at centers with expertise in the diagnosis and management of this disorder, but the HSSPs at these expert centers are unable to provide specialty PAH medications. The current care model for PAH leads to patients receiving their medical and pharmaceutical care from separate entities. This descriptive report describes a multidisciplinary team's approach to gaining access to providing ambrisentan and developing a disease state care team within an established HSSP. After implementing this service, specialty pharmacy metrics were assessed, including proportion of days covered (PDC), time to first fill, patient contact rate, Risk Evaluation and Mitigation Strategy (REMS) program compliance, time to prior authorization (PA) approval, rate of optimal adherence (PDC of >80%), and PA renewal rate, to demonstrate a proof-of-concept HSSP model for PAH. In this model, the HSSP was able to demonstrate high-quality specialty pharmacy metrics with regard to medication adherence, medication access, and REMS program compliance. CONCLUSION: The development of a PAH care team to provide ambrisentan at an existing HSSP was associated with high adherence rates, efficient and reliable medication access, and REMS program compliance.

An Interdisciplinary Videoconference to Improve Transitions of Care and Reduce Readmission, Cost, and Post-Acute Length of Stay in a Teaching and Community Hospital.

OBJECTIVES: Coordination of care across health care settings is needed to ensure safe patient transfers. We examined the effects of the ECHO-Care Transitions program (ECHO-CT) on readmissions, skilled nursing facility (SNF) length of stay (LOS), and costs. DESIGN: This is a prospective cohort study evaluating the ECHO-CT program. The intervention consisted of weekly 90-minute teleconferences between hospital and SNF-based teams to discuss the care of recently discharged patients. SETTING AND PARTICIPANTS: The intervention occurred at one small community hospital and 7 affiliated SNFs and 1 large teaching hospital and 11 associated SNFs between March 23, 2019, and February 25, 2021. A total of 882 patients received the intervention. METHODS: We selected 13 hospitals and 172 SNFs as controls. Specific hospital-SNF pairings within the intervention and control groups are referred to as hospital-SNF dyads. Using Medicare claims data for more than 10,000 patients with transfers between these hospital-SNF dyads, we performed multivariable regression to evaluate differences in 30-day rehospitalization rates, SNF lengths of stay, and SNF costs between patients discharged to intervention and control hospital-SNF dyads. We split the post period into pre-COVID and COVID periods and ran models separately for the small community and large teaching hospitals. RESULTS: There was no significant difference-in-differences among intervention compared to control facilities during either post-acute care period for any of the outcomes. CONCLUSIONS AND IMPLICATIONS: Although video-communication of care plans between hospitalists and post-acute care clinicians makes good clinical sense, our analysis was unable to detect significant reductions in rehospitalizations, SNF lengths of stay, or SNF Medicare costs. Disruption of the usual processes of care by the COVID pandemic may have played a role in the null findings.

Pre-hospitalization dysphagia and feeding tube placement in nursing home residents with advanced dementia.

BACKGROUND: Despite research demonstrating the risks of using feeding tubes in persons with advanced dementia, they continue to be placed. The natural history of dysphagia among patients with advanced dementia has not been examined. We conducted a secondary analysis of a national cohort of persons with advanced dementia staying at a nursing home stay before hospitalization to examine (1) pre-hospitalization dysphagia prevalence and (2) risk of feeding tube placement during hospitalization based on preexisting dysphagia. METHODS: A retrospective cohort study consisting of all nursing home (NH) residents (≥66 years) with advanced dementia (Cognitive Function Scale score ≥2), a hospitalization between 2013-2017, and a Minimum Data Set (MDS) 3.0 assessment within 120 days before hospitalization. Pre-hospitalization dysphagia status and surgically placed feeding tube insertion during hospitalization were determined by MDS 3.0 swallowing items and ICD-9 codes, respectively. A multivariate logistic model clustering on hospital was used to examine the association of dysphagia with percutaneous endoscopic gastrostomy (PEG) feeding tube placement after adjustment for confounders. RESULTS: Between 2013 and 2017, 889,983 persons with NH stay with advanced dementia (mean age: 84.5, SD: 7.5, and 63.5% female) were hospitalized. Pre-hospitalization dysphagia was documented in 5.4% (n = 47,574) and characterized by oral dysphagia (n = 21,438, 2.4%), pharyngeal dysphagia (n = 24,257, 2.7%), and general swallowing complaints/pain (n = 14,928, 1.7%). Overall, PEG feeding tubes were placed in 3529 patients (11.2%) with pre-hospitalization dysphagia, whereas 27,893 (88.8%) did not have pre-hospitalization dysphagia according to MDS 3.0 items. Feeding tube placement risk increased with the number of dysphagia items noted on the pre-hospitalization MDS (6 vs. 0 dysphagia variables: OR = 5.43, 95% CI: 3.19-9.27). CONCLUSIONS: Based on MDS 3.0 assessment, only 11% of PEG feeding tubes were inserted in persons with prior dysphagia. Future research is needed on whether this represents inadequate assessment or the impact of potentially reversible intercurrent illness resulting in feeding tube placement.

Targeting Acute Myeloid Leukemia Stem Cells Through Perturbation of Mitochondrial Calcium.

We previously reported that acute myeloid leukemia stem cells (LSCs) are uniquely reliant on oxidative phosphorylation (OXPHOS) for survival. Moreover, maintenance of OXPHOS is dependent on BCL2, creating a therapeutic opportunity to target LSCs using the BCL2 inhibitor drug venetoclax. While venetoclax-based regimens have indeed shown promising clinical activity, the emergence of drug resistance is prevalent. Thus, in the present study, we investigated how mitochondrial properties may influence mechanisms that dictate venetoclax responsiveness. Our data show that utilization of mitochondrial calcium is fundamentally different between drug responsive and non-responsive LSCs. By comparison, venetoclax-resistant LSCs demonstrate a more active metabolic (i.e., OXPHOS) status with relatively high steady-state levels of calcium. Consequently, we tested genetic and pharmacological approaches to target the mitochondrial calcium uniporter, MCU. We demonstrate that inhibition of calcium uptake sharply reduces OXPHOS and leads to eradication of venetoclax-resistant LSCs. These findings demonstrate a central role for calcium signaling in the biology of LSCs and provide a therapeutic avenue for clinical management of venetoclax resistance.

Fluid Responsiveness in Critically Ill Patients Using Carotid Peak Systolic Velocity Variability: A New Frontier.

Background and objectives A fluid responder is a patient who can increase his stroke volume/ cardiac output by more than 10%-15% after a fluid bolus. Left ventricular outflow tract (LVOT) velocity time integral (VTI) variability is widely used as an adynamic parameter of fluid responsiveness, but a transthoracic echo view of LVOT VTI is often time-consuming and, at times, difficult to achieve. So, in the quest for another parameter that might equally be a good surrogate marker of stroke volume variation, carotid peak systolic velocity (CPSV) variation has been studied. The objective was to assess CPSV variation in patients who are already fluid responders. Methods The sample size was calculated considering a minimum correlation coefficient of 0.5. Adult patients in whom the physician wanted to give a fluid bolus and whose average LVOT VTI was more than 15% over 3 respiratory cycles were included in the study. Demographic variables, along with hemodynamic parameters such as heart rate, blood pressure, the need for vasopressors, mode of breathing (spontaneous or mechanical ventilation), and CPSV variation,were noted and averaged over three respiratory cycles. Fluid bolus (Plasmalyte) 6 ml/kg bolus over 10-15 minutes. Post-fluid hemodynamic variables, along with averaged LVOT VTI over three respiratory cycles and averaged CPSV variation over three respiratory cycles, are noted. Results Thirty adult patients were evaluated in the study. In spontaneously breathing patients (n=12), the average CPSV variation expressed as mean + standard deviation before and after fluid administration of 6ml/kg of ideal body weight was 14.1 ± 3.4 and 5.4 ± 2.6, respectively (p < 0.05). In mechanically ventilated patients (n=18), the average CPSV variation expressed as mean + standard deviation before and after fluid administration of 6ml/kg of ideal body weight fluid was 15 ± 5.3 and 6.5 ± 3.1, respectively (p <0.005). Overall, there was a statistically significant positive correlation between LVOT VTI variation and CPSV variation before fluid therapy (correlation coefficient 0.56 and p-value 0.001) and a statistically significant moderate positive correlation post-fluid therapy (correlation coefficient 0.37 and p-value 0.043). Conclusion We found a significant decrease in CPSV variation post-fluid administration in patients who are fluid responders, which mimics a decrease in stroke volume variation after fluid administration in patients who are fluid responsive.

A Novel Type of Monocytic Leukemia Stem Cell Revealed by the Clinical Use of Venetoclax-Based Therapy.

The BCL2 inhibitor venetoclax has recently emerged as an important component of acute myeloid leukemia (AML) therapy. Notably, use of this agent has revealed a previously unrecognized form of pathogenesis characterized by monocytic disease progression. We demonstrate that this form of disease arises from a fundamentally different type of leukemia stem cell (LSC), which we designate as monocytic LSC (m-LSC), that is developmentally and clinically distinct from the more well-described primitive LSC (p-LSC). The m-LSC is distinguished by a unique immunophenotype (CD34-, CD4+, CD11b-, CD14-, CD36-), unique transcriptional state, reliance on purine metabolism, and selective sensitivity to cladribine. Critically, in some instances, m-LSC and p-LSC subtypes can co-reside in the same patient with AML and simultaneously contribute to overall tumor biology. Thus, our findings demonstrate that LSC heterogeneity has direct clinical significance and highlight the need to distinguish and target m-LSCs as a means to improve clinical outcomes with venetoclax-based regimens. SIGNIFICANCE: These studies identify and characterize a new type of human acute myeloid LSC that is responsible for monocytic disease progression in patients with AML treated with venetoclax-based regimens. Our studies describe the phenotype, molecular properties, and drug sensitivities of this unique LSC subclass. This article is featured in Selected Articles from This Issue, p. 1949.

Pancreatic islet cell type-specific transcriptomic changes during pregnancy and postpartum.

Pancreatic ß-cell mass expands during pregnancy and regresses in the postpartum period in conjunction with dynamic metabolic demands on maternal glucose homeostasis. To understand transcriptional changes driving these adaptations in ß-cells and other islet cell types, we performed single-cell RNA sequencing on islets from virgin, late gestation, and early postpartum mice. We identified transcriptional signatures unique to gestation and the postpartum in ß-cells, including induction of the AP-1 transcription factor subunits and other genes involved in the immediate-early response (IEGs). In addition, we found pregnancy and postpartum-induced changes differed within each endocrine cell type, and in endothelial cells and antigen-presenting cells within islets. Together, our data reveal insights into cell type-specific transcriptional changes responsible for adaptations by islet cells to pregnancy and their resolution postpartum.

Vitamin C Status of US Adults Assessed as Part of the National Health and Nutrition Examination Survey Remained Unchanged between 2003-2006 and 2017-2018.

BACKGROUND: We compared serum vitamin C (VIC) status of the adult (≥20 y) US population in the National Health and Nutrition Examination Survey (NHANES) 2017-2018 with combined data from 2003-2004 and 2005-2006. METHODS: VIC was measured using HPLC with electrochemical detection. Mean data were stratified by age, sex, race/Hispanic origin, income, body mass index, dietary intake, supplement use, and smoking status. Prevalence of VIC deficiency (<11.4 µmol/L) was calculated. RESULTS: In NHANES 2017-2018, the mean VIC was 8 µmol/L higher in people ≥60 y compared with those 20-59 y of age, 10 µmol/L lower in men vs women, 8 µmol/L lower in low vs high income, 11 µmol/L lower in obese vs healthy weight, and 15 µmol/L lower in smokers vs nonsmokers. Differences in mean VIC across race/Hispanic origin groups ranged from 2 to 7 µmol/L. Mean VIC was 27 µmol/L higher with vitamin C-containing supplement use and positively associated (Spearman ρ = 0.33; P < 0.0001) with increasing dietary intake. The associations between mean VIC and the investigated covariates were generally consistent and the prevalence of deficiency was not significantly different between survey periods (6.8% vs 7.0%; P = 0.83). However, a few subgroups had double the risk. We found no significant survey differences in mean VIC (51.2 vs 54.0 µmol/L; P = 0.09). CONCLUSIONS: Overall VIC status of the US adult population has remained stable since last assessed in the NHANES 2005-2006 survey. Vitamin C deficiency remained high for those with low dietary intake and who smoke.

The relationship between exposure to Hurricane Harvey and mortality among nursing home residents.

BACKGROUND: Nursing home (NH) residents are vulnerable to mortality after natural disasters. We examined NH residents' excess all-cause mortality associated with Hurricane Harvey, a unique disaster with long-lasting flooding effects. We also explored how mortality differed between short-stay and long-stay residents and by chronic conditions. METHODS: We conducted a retrospective observational study of Texas NH residents, comparing 30- and 90-day mortality among residents exposed to Hurricane Harvey in August 2017 to residents not exposed in the same location and time period during the previous 2 years. Data came from the Minimum Data Set Assessments and the Medicare Beneficiary Summary File. We used linear probability models to examine the association between hurricane exposure and mortality, adjusting for resident demographics, clinical acuity, and NH fixed effects. Models were stratified by short-stay and long-stay status. We also described differences in mortality by residents' chronic conditions. RESULTS: In 2017, 18,479 Texas NH residents were exposed to Hurricane Harvey. Exposure to Hurricane Harvey was not significantly associated with 30-day mortality. However, 7.6% (95% CI: 7.2, 7.9) of long-stay residents died 90 days after exposure to Harvey, compared to 6.3% (95% CI: 6.0, 6.7) during 2015. Apparently, this effect was driven by chronic obstructive pulmonary disease (COPD) as approximately 9.2% of these residents died within 90 days after Harvey landing compared to 7.2% in 2015 (p < 0.01). CONCLUSIONS: Hurricane exposure appears to have significant consequences for mortality among long-stay NH residents, which appear to materialize over the long-term (90 days post-hurricane in our study) and may not be apparent immediately (30 days post-hurricane in our study). NH residents with COPD may be particularly vulnerable to increased mortality risk following hurricane exposure. The results highlight the need to pay special attention to mortality risk in NH residents, particularly those with COPD, following hurricane exposure.

Colonic Microflora Protagonist of Liver Metabolism and Gut Permeability: Study on Mice Model.

Alteration of gut microflora results in a metabolic imbalance in the liver. In the present study, we investigate the reversal potential of alteration of the colonic microflora via improving metabolism balance and regulating the altered tight junction of the intestinal tract. Animals were fed with high sugar diet to mimic the onset of the pathophysiological conditions of diabetes. Following induction, animals were divided into two reversal groups i.e., crude cefdinir and colon-specific formulated cefdinir, to alter the gut microflora. In the present study, we have tried to quantify the microbial content via metagenome analysis to provide an actual picture of the alteration and subsequent reversal. Expression of mRNA of junctional protein and parameters involved in liver metabolism was determined using qPCR. Results indicated direct effect of altered composition of gut microflora on the gut permeability and metabolic alteration. Metagenomic analysis showed least evenness and richness in the HSD group whereas antibiotic-treated groups showed reversal of microflora towards control group with increased richness, evenness and decreased distance on PCoA plot. This changes in gut microflora composition changes expression of metabolic markers and thus insulin sensitivity. Targeting colonic microflora to have a reversal effect on T2D pathogenesis, found to have a positive impact on liver metabolic state with improved permeability markers of gut with SCFA alteration. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-022-01032-x.

Gut microbiome and type 2 diabetes.

Dietary patterns with excess caloric have shaped a complex metabolic disorders like type 2 diabetes (T2D). T2D involves complications in the metabolism of glucose, lipid, cholesterol and their storage. Along with the metabolic dysregulation, systemic inflammation is also the reason for Insulin Resistance and T2D. The importance of gut microbiota has recently been highlighted. It establishes a link between dietary patterns and the types of bacteria that overgrow and modify fermentation bi-products such as SCFA, secondary bile acids, and mucosal immune cells. These changes have a direct impact on the liver's metabolism and immune system. As a result, using Pre-Pro-biotics to manage microbiota can assist overcome or lessening disease symptoms. Antibiotics are currently employed to produce a germ-free environment or to eradicate specific types of bacteria in order to better understand the role of microflora. This chapter covers the basics of good bacteria, as well as the mechanisms that they work on.

Ex Vivo Expansion of Phenotypic and Transcriptomic Chronic Myeloid Leukemia Stem Cells.

Despite decades of research, standard therapies remain ineffective for most leukemias, pushing toward an essential unmet need for targeted drug screens. Moreover, preclinical drug testing is an important consideration for success of clinical trials without affecting non-transformed stem cells. Using the transgenic chronic myeloid leukemia (CML) mouse model, we determine that leukemic stem cells (LSCs) are transcriptionally heterogenous with a preexistent drug-insensitive signature. To test targeting of potentially important pathways, we establish ex vivo expanded LSCs that have long-term engraftment and give rise to multilineage hematopoiesis. Expanded LSCs share transcriptomic signatures with primary LSCs including enrichment in Wnt, JAK-STAT, MAPK, mTOR and transforming growth factor ß signaling pathways. Drug testing on expanded LSCs show that transforming growth factor ß and Wnt inhibitors had significant effects on the viability of LSCs, but not leukemia-exposed healthy HSCs. This platform allows testing of multiple drugs at the same time to identify vulnerabilities of LSCs.

Orange G is a potential inhibitor of human insulin amyloid fibrillation and can be used as a probe to study mechanism of amyloid fibrillation and its inhibition.

The extracellular insoluble deposits of highly ordered cross-ß-structure-containing amyloid fibrils form the pathological basis for protein misfolding diseases. As amyloid fibrils are cytotoxic, inhibition of the process is a therapeutic strategy. Several small molecules have been identified and used as fibrillation inhibitors in the recent past. In this work, we investigate the effect of Orange G on insulin amyloid formation using fluorescence-based assays and negative-stain electron microscopy (EM). We show that Orange G effectively attenuates nucleation, thereby inhibiting amyloid fibrillation in a dose-dependent manner. Fluorescence quenching titrations of Orange G showed a reasonably strong binding affinity to native insulin. Binding isotherm measurements revealed the binding of Orange G to pre-formed insulin fibrils too, indicating that Orange G likely binds and stabilizes the mature fibrils and prevents the release of toxic oligomers which could be potential nuclei or templates for further fibrillation. Molecular docking of Orange G with native insulin and amyloid-like peptide structures were also carried out to analyse the contributing interactions and binding free energy. The findings of our study emphasize the use of Orange G as a molecular probe to identify and design inhibitors of amyloid fibrillation and to investigate the structural and toxic mechanisms underlying amyloid formation.

Deciphering Metabolic Adaptability of Leukemic Stem Cells.

Therapeutic targeting of leukemic stem cells is widely studied to control leukemia. An emerging approach gaining popularity is altering metabolism as a potential therapeutic opportunity. Studies have been carried out on hematopoietic and leukemic stem cells to identify vulnerable pathways without impacting the non-transformed, healthy counterparts. While many metabolic studies have been conducted using stem cells, most have been carried out in vitro or on a larger population of progenitor cells due to challenges imposed by the low frequency of stem cells found in vivo. This creates artifacts in the studies carried out, making it difficult to interpret and correlate the findings to stem cells directly. This review discusses the metabolic difference seen between hematopoietic stem cells and leukemic stem cells across different leukemic models. Moreover, we also shed light on the advancements of metabolic techniques and current limitations and areas for additional research of the field to study stem cell metabolism.

Plant based Bioavailability Enhancers.

Many of the synthetic and herbal drugs, despite their notable in vitro findings, demonstrate insignificant in vivo activity, the majority of the time due to poor bioavailability. As per Biopharmaceutical Classification System (BCS), one of the main concerns is low solubility and/or permeation of drugs resulting in reduced absorption and poor bioavailability. To overcome these issues, various strategies have been adopted, including the use of permeation enhancers which are also known as bioenhancers. Bioenhancers are synthetic or natural compounds that increase the bioavailability of drugs and nutrients such as vitamins, amino acids, minerals, etc., into the systemic circulation and at the site of action for exhibiting improved therapeutic action. By improving bioavailability, bioenhancers can reduce drug dose, decrease the treatment period, and circumvent the problem of drug resistance. Although numerous studies have reported the application of synthetic bioenhancers, plant based bioenhancers can serve as a better alternative owing to their natural origin. Literature reviews have revealed that plant-based bioenhancers have been used in a wide variety of antibiotics, antiviral, and anti-cancer therapeutics. These can be categorized based on their sources and mechanism of action. This review will provide a systematic and detailed overview of the various plant based bioenhancers and their applications.