Preoperative dietitian-led Very Low Calorie Diet (VLCD) Clinic for adults living with obesity undergoing gynaecology, laparoscopic cholecystectomy and hernia repair procedures: a pilot parallel randomised controlled trial.

Obesity can increase the risk of postoperative complications. Despite increased demand for patients living with obesity to lose weight prior to common surgical procedures, the impact of intentional weight loss on surgical outcomes is largely unknown. We aimed to conduct a pilot study to assess the feasibility of a full-scale randomised controlled trial (RCT) to examine the effect of preoperative dietitian-led Very Low Calorie Diet (VLCD) Clinic on surgical outcomes in gynaecology and general surgeries. Between August 2021 and January 2023, a convenience sample of adults living with obesity (BMI ≥ 30 kg/m2) awaiting gynaecology, laparoscopic cholecystectomy and ventral hernia repair procedures were randomised to dietitian-led VLCD (800-1000 kcal using meal replacements and allowed foods), or control (no dietary intervention), 2-12 weeks preoperatively. Primary outcome was feasibility (recruitment, adherence, safety, attendance, acceptability and quality of life (QoL)). Secondary outcomes were anthropometry and 30-d postoperative outcomes. Outcomes were analysed as intention-to-treat. Fifty-one participants were recruited (n 23 VLCD, n 28 control), mean 48 (sd 13) years, 86 % female, and mean BMI 35·8 (sd 4·6) kg/m2. Recruitment was disrupted by COVID-19, but other thresholds for feasibility were met for VLCD group: high adherence without unfavourable body composition change, high acceptability, improved pre/post QoL (22·1 ± 15 points, < 0·001), with greater reductions in weight (-5·5 kg VLCD v. -0·9 kg control, P < 0·05) waist circumference (-6·6 cm VLCD v. +0·6 control, P < 0·05) and fewer 30-d complications (n 4/21) than controls (n 8/22) (P > 0·05). The RCT study design was deemed feasible in a public hospital setting. The dietitian-led VLCD resulted in significant weight loss and waist circumference reduction compared with a control group, without unfavourable body composition change and improved QoL.

Impact of a dietitian-led very low calorie diet clinic on perioperative risk for patients with obesity awaiting elective, non-bariatric surgery: A retrospective cohort study.

BACKGROUND: Despite a lack of evidence that intentional weight loss reduces the risk of postoperative complications, adults with obesity are commonly asked to lose weight before elective surgery. We hypothesized that patients undertaking dietitian-led preoperative, very low calorie diet treatment could reduce perioperative surgery risks, as per validated risk scoring systems. The purpose of this study was to measure the impact of a dietitian-led preoperative very low calorie diet clinic on the American Society of Anesthesiologists physical status scores and National Surgical Quality Improvement Program Surgical Risk Calculator scores for patients with obesity awaiting non-bariatric elective surgery. METHODS: This retrospective cohort study included patients referred to the preoperative dietitian-led very low calorie diet clinic before elective surgical procedures over a 2-year-9-month period. The dietitian prescribed individualized, very low calorie diet-based treatment. Primary outcomes were changes in the American Society of Anesthesiologists and Surgical Risk Calculator scores from pretreatment until surgery. RESULTS: A total of 141 eligible participants (48 ± 13.4 years, 76% women, body mass index 41.7 ± 6.3 kg/m2) demonstrated clinically significant weight loss (mean 7.1 ± 6.1kg, 5.2% body weight, P < .001). Median treatment duration was 13 weeks (interquartile range 6.2-19.2 weeks). Five participants (3.5%) avoided surgery due to weight loss-related improvements in their condition. American Society of Anesthesiologists scores improved for 16% (n = 22/141) of participants. Overall, the median surgical risk calculator estimated risk of 'serious' and 'any' postoperative complication reduced from 4.8% to 3.9% (P < .001) and 6% to 5.1% (P < .001), respectively. Reduction in all Surgical Risk Calculator scores occurred, including surgical site infection, re-admission, and cardiac events (P < .05). CONCLUSION: The dietitian-led preoperative, very low calorie diet clinic improved American Society of Anesthesiologists and Surgical Risk Calculator scores for non-bariatric elective surgery patients with obesity. Randomized controlled trials comparing this approach with a control group are warranted.

Survey of Australian clinicians' antenatal care and management practices in pregnant women with a history of bariatric surgery.

Background: Pregnancy following bariatric surgery requires tailored care. The current Australian care provision and its alignment with consensus guidelines is unclear. Methods: Antenatal care clinicians were invited to complete a web-based survey assessing multidisciplinary referral, gestational diabetes mellitus (GDM) and micronutrient management practices. Results: Respondents (n = 100) cared for pregnant women with a history of bariatric surgery at least monthly (63%) with most (54%) not using a specific guideline to direct care. GDM screening methods included one-week of home blood glucose monitoring (43%) or the oral glucose tolerance test (42%). Pregnancy multivitamin supplementation changes (59%) with bariatric surgery type were common. Half (54%) screened for micronutrient deficiencies every trimester and conducted additional growth ultrasounds (50%). Conclusion: The care clinicians report providing may not align with current international consensus guidelines. Further studies with increased obstetric clinician response may aid increased understanding of current practices. The development of workplace management guidelines for pregnancy in women with a history of bariatric surgery may assist with providing consistent evidence-based care.

Multi-site evaluation of advanced practice hand therapy clinics for the management of patients with trigger digit.

STUDY DESIGN: Prospective cohort design. BACKGROUND: Patient time on Australian public hospital surgical outpatient department (SOPD) waitlists often exceeds clinical recommendations for chronic hand conditions. Diversion to allied health is an alternative option, however evidence regarding patient and organizational outcomes in hand therapy is lacking. PURPOSE OF THE STUDY: To evaluate clinical and organizational efficacy, patient outcomes and satisfaction of diversion of referrals for patients with trigger digit (TD) from SOPD waitlists to Advanced Practice Hand Therapy (APHT) at 3 Australian hospitals. METHODS: Data was collected from eligible patients with TD through chart reviews and telephone satisfaction surveys. Data included number of patients requiring SOPD review, repeat referral to SOPD in the 12 months following APHT discharge, patient-rated outcomes, satisfaction scores, wait times to SOPD review and conversion to surgery-rates. Mann Whitney-U, t-test, Pearson's chi-squared test and a Binary Logistic Regression analysis were performed. RESULTS: 104 patients completed APHT treatment. Seventy patients (67%) did not require return to the SOPD waitlist. Repeat referral to SOPD within 12 months of APHT discharge occurred for only 1 patient. Patients requiring SOPD review after APHT treatment were seen within target time frames and demonstrated 88% conversion to surgery-rates. Michigan Hand Outcome Questionnaire scores showed greater improvement in those not requiring SOPD review (P< .001~25.9 vs 4.2). Regression analysis identified a negative association between initial total Michigan Hand Outcome Questionnaire scores and unfavorable discharge outcomes (OR 0.96, P= .007). Most (81%-93%) patients indicated satisfaction with the APHT service. CONCLUSION: Diversion of referrals for TD from SOPD to APHT is an effective waitlist management strategy, with the propensity to reduce waiting times, improve patient flow, whilst resulting in favorable clinical and patient-rated outcomes and satisfaction.

Elective Surgery in Adult Patients with Excess Weight: Can Preoperative Dietary Interventions Improve Surgical Outcomes? A Systematic Review.

This systematic review summarises the literature regarding the impact of preoperative dietary interventions on non-bariatric surgery outcomes for patients with excess weight/obesity, a known risk factor for poor surgical outcomes. Four electronic databases were searched for non-bariatric surgery studies that evaluated the surgical outcomes of a preoperative diet that focused on weight/fat loss or improvement of liver steatosis. Meta-analysis was unfeasible due to the extreme heterogeneity of variables. Fourteen studies, including five randomised controlled trials, were selected. Laparoscopic cholecystectomy, hernia repair, and liver resection were most studied. Diet-induced weight loss ranged from 1.4 kg to 25 kg. Preoperative very low calorie diet (≤800 kcal) or low calorie diet (≤900 kcal) for one to three weeks resulted in: reduction in blood loss for two liver resection and one gastrectomy study (-27 to -411 mL, p < 0.05), and for laparoscopic cholecystectomy, reduction of six minutes in operating time (p < 0.05) and reduced difficulty of aspects of procedure (p < 0.05). There was no difference in length of stay (n = 7 studies). Preoperative ≤ 900 kcal diets for one to three weeks could improve surgical outcomes for laparoscopic cholecystectomy, liver resection, and gastrectomy. Multiple randomised controlled trials with common surgical outcomes are required to establish impact on other surgeries.

Novel tricyclic glycal-based TRIB1 inducers that reprogram LDL metabolism in hepatic cells.

Increased expression of the Tribbles pseudokinase 1 gene (TRIB1) is associated with lower plasma levels of LDL cholesterol and triglycerides, higher levels of HDL cholesterol and decreased risk of coronary artery disease and myocardial infarction. We identified a class of tricyclic glycal core-based compounds that upregulate TRIB1 expression in human HepG2 cells and phenocopy the effects of genetic TRIB1 overexpression as they inhibit expression of triglyceride synthesis genes and ApoB secretion in cells. In addition to predicted effects related to downregulation of VLDL assembly and secretion these compounds also have unexpected effects as they upregulate expression of LDLR and stimulate LDL uptake. This activity profile is unique and favorably differs from profiles produced by statins or other lipoprotein targeting therapies. BRD8518, the initial lead compound from the tricyclic glycal class, exhibited stereochemically dependent activity and the potency far exceeding previously described benzofuran BRD0418. Gene expression profiling of cells treated with BRD8518 demonstrated the anticipated changes in lipid metabolic genes and revealed a broad stimulation of early response genes. Consistently, we found that BRD8518 activity is MEK1/2 dependent and the treatment of HepG2 cells with BRD8518 stimulates ERK1/2 phosphorylation. In agreement with down-regulation of genes controlling triglyceride synthesis and assembly of lipoprotein particles, the mass spectrometry analysis of cell extracts showed reduced rate of incorporation of stable isotope labeled glycerol into triglycerides in BRD8518 treated cells. Furthermore, we describe medicinal chemistry efforts that led to identification of BRD8518 analogs with enhanced potency and pharmacokinetic properties suitable for in vivo studies.

Dietitians' opinions regarding refeeding syndrome, clinical guidelines and extended scope of practice.

AIM: Refeeding syndrome (RFS) prevalence rates vary across studies depending on the criteria used for assessment and identification. For registered dietitians, the assessment and management of RFS is highly reliant on daily serum electrolyte values; however, registered dietitians working within Australia do not currently possess laboratory test ordering privileges. We aimed to examine the opinions of registered dietitians regarding RFS identification, management and guidelines and the option of using extended scope of practice to order electrolyte monitoring autonomously. METHODS: A multi-method action research approach was used, incorporating two projects. The first was a survey examining Australian registered dietitians' (n = 187) opinions regarding RFS identification, management and guidelines, and autonomous electrolyte monitoring. To establish if results were similar internationally, an interview was conducted with 22 registered dietitians working within 10 different countries. Data were analysed using chi-square tests and thematic analysis. RESULTS: Australian registered dietitians (75%) identify patients at risk of RFS at a high rate of more than once per fortnight, with 74% reporting that they have previously worked with a patient diagnosed with RFS. Results varied internationally, with respondents from eight countries reporting that RFS is a problem within acute care versus respondents from five countries having never treated a patient with RFS. The majority (≥89%) of registered dietitians desire new guidelines and the option to order patient electrolyte monitoring autonomously. CONCLUSIONS: Our findings suggest that more stringent tools for the identification of RFS are necessary. There was limited uniformity across countries, and updated practice guidelines are needed.

Investigating antenatal nutrition education preferences in South-East Queensland, including Maori and Pasifika women.

BACKGROUND: Little is reported about the nutrition-related needs and preferences of women seeking maternity services, particularly Maori and Pasifika (M&P) women who have higher chronic disease rates in Queensland. AIM: Nutrition-related knowledge, needs, behaviours and education preferences were compared between women of M&P ancestry and non-Maori and Pasifika women (NMP). METHOD: Women (≥18 years) admitted to the postnatal ward were surveyed. Anthropometry, dietary quality, nutrition education preferences, country of birth and ancestry were collected. Analysis included chi-squared and t-tests. FINDINGS: The survey was completed by 399 eligible women. Country of birth data suggested 4% of respondents were Pasifika and failed to separately identify New Zealand Maori, whereas 18% of respondents (n=73) reported M&P ancestry. Descriptors were similar between groups (28±5 years; 91% any breastfeeding; 18% gestational diabetes mellitus; p>0.05). However M&P women were less often university educated (M&P:6(9%); NMP:71(22%), p<0.01) and more likely had >2 children (M&P: 30(54%); NMP:70(30%), p<0.01). M&P women reported heavier weight at conception (M&P:79.0±20.2kg, 29.2±7.5kg/m2; NMP:71.3±18.9kg, 26.3±6.5kg/m2, p<0.01), and were more likely to report excess gestational weight gain (M&P:30(56%), NMP:96(36%), p<0.05). Most (>75%) women did not know their recommended weight gain. Many respondents reported inadequate intake of vegetables (95%), fruit (29%) and dairy (69%) during pregnancy. Two-fifths (38-41%) reported interest in perinatal nutrition education, with topics including healthy eating postpartum. DISCUSSION: Findings enable targeted service delivery according to women's preferences. CONCLUSION: Collecting ancestral and maternal data to facilitate the provision of appropriate nutrition education may be critical for achieving optimal maternal outcomes in Maori and Pasifika women.

The accuracy and consistency of nutrition care process terminology use in cases of refeeding syndrome.

AIM: Using standardised terminology in acute care has encouraged consistency in patient care and the evaluation of outcomes. As such, the Nutrition Care Process (NCP) and Nutrition Care Process Terminology (NCPT) may assist dietitian nutritionists in the delivery of high quality nutrition care worldwide; however, limited research has been conducted examining the consistency and accuracy of its use. We aimed to examine the NCPT that dietitian nutritionists would use to formulate a diagnostic statement relating to refeeding syndrome (RFS). METHODS: A multimethod action research approach was used, incorporating two projects. The first was a survey examining Australian dietitian nutritionists' (n = 195) opinions regarding NCPT use in cases of RFS. To establish if results were similar internationally, an interview was then conducted with 22 dietitian nutritionists working within 10 different countries. RESULTS: 'Imbalance of nutrients' was only identified as a correct code by 17% of respondents in project 1. No mention of this term was made in project 2. Also 86% of respondents incorrectly selected more than one diagnostic code. The majority of respondents (80%, n = 52/65) who incorrectly selected 'Malnutrition', without also selecting 'Imbalance of nutrients', selected 'reduce intake' as an intervention, suggesting some misunderstanding in the requirement for interrelated diagnoses, interventions and goals. CONCLUSIONS: Our findings demonstrate that there is limited accuracy and consistency in selecting nutritional diagnostic codes in relation to RFS. Respondents also demonstrated limited knowledge regarding appropriate application of the NCP and NCPT. Implementation practices may require further refinement, as accurate and consistent use is required to procure the benefits of standardised terminology.

Identification of Highly Specific Diversity-Oriented Synthesis-Derived Inhibitors of Clostridium difficile.

In 2013, the Centers for Disease Control highlighted Clostridium difficile as an urgent threat for antibiotic-resistant infections, in part due to the emergence of highly virulent fluoroquinolone-resistant strains. Limited therapeutic options currently exist, many of which result in disease relapse. We sought to identify molecules specifically targeting C. difficile in high-throughput screens of our diversity-oriented synthesis compound collection. We identified two scaffolds with apparently novel mechanisms of action that selectively target C. difficile while having little to no activity against other intestinal anaerobes; preliminary evidence suggests that compounds from one of these scaffolds target the glutamate racemase. In vivo efficacy data suggest that both compound series may provide lead optimization candidates.

Novel diversity-oriented synthesis-derived respiratory syncytial virus inhibitors identified via a high throughput replicon-based screen.

Respiratory syncytial virus (RSV) infections affect millions of children and adults every year. Despite the significant disease burden, there are currently no safe and effective vaccines or therapeutics. We employed a replicon-based high throughput screen combined with live-virus triaging assays to identify three novel diversity-oriented synthesis-derived scaffolds with activity against RSV. One of these small molecules is shown to target the RSV polymerase (L protein) to inhibit viral replication and transcription; the mechanisms of action of the other small molecules are currently unknown. The compounds described herein may provide attractive inhibitors for lead optimization campaigns.

High-throughput identification of genotype-specific cancer vulnerabilities in mixtures of barcoded tumor cell lines.

Hundreds of genetically characterized cell lines are available for the discovery of genotype-specific cancer vulnerabilities. However, screening large numbers of compounds against large numbers of cell lines is currently impractical, and such experiments are often difficult to control. Here we report a method called PRISM that allows pooled screening of mixtures of cancer cell lines by labeling each cell line with 24-nucleotide barcodes. PRISM revealed the expected patterns of cell killing seen in conventional (unpooled) assays. In a screen of 102 cell lines across 8,400 compounds, PRISM led to the identification of BRD-7880 as a potent and highly specific inhibitor of aurora kinases B and C. Cell line pools also efficiently formed tumors as xenografts, and PRISM recapitulated the expected pattern of erlotinib sensitivity in vivo.

Indolinyl-Thiazole Based Inhibitors of Scavenger Receptor-BI (SR-BI)-Mediated Lipid Transport.

A potent class of indolinyl-thiazole based inhibitors of cellular lipid uptake mediated by scavenger receptor, class B, type I (SR-BI) was identified via a high-throughput screen of the National Institutes of Health Molecular Libraries Small Molecule Repository (NIH MLSMR) in an assay measuring the uptake of the fluorescent lipid DiI from HDL particles. This class of compounds is represented by ML278 (17-11), a potent (average IC50 = 6 nM) and reversible inhibitor of lipid uptake via SR-BI. ML278 is a plasma-stable, noncytotoxic probe that exhibits moderate metabolic stability, thus displaying improved properties for in vitro and in vivo studies. Strikingly, ML278 and previously described inhibitors of lipid transport share the property of increasing the binding of HDL to SR-BI, rather than blocking it, suggesting there may be similarities in their mechanisms of action.

Discovery of bisamide-heterocycles as inhibitors of scavenger receptor BI (SR-BI)-mediated lipid uptake.

A new series of potent inhibitors of cellular lipid uptake from HDL particles mediated by scavenger receptor, class B, type I (SR-BI) was identified. The series was identified via a high-throughput screen of the National Institutes of Health Molecular Libraries Small Molecule Repository (NIH MLSMR) that measured the transfer of the fluorescent lipid DiI from HDL particles to CHO cells overexpressing SR-BI. The series is characterized by a linear peptidomimetic scaffold with two adjacent amide groups, as well as an aryl-substituted heterocycle. Analogs of the initial hit were rapidly prepared via Ugi 4-component reaction, and select enantiopure compounds were prepared via a stepwise sequence. Structure-activity relationship (SAR) studies suggest an oxygenated arene is preferred at the western end of the molecule, as well as highly lipophilic substituents on the central and eastern nitrogens. Compound 5e, with (R)-stereochemistry at the central carbon, was designated as probe ML279. Mechanistic studies indicate that ML279 stabilizes the interaction of HDL particles with SR-BI, and its effect is reversible. It shows good potency (IC50=17 nM), is non-toxic, plasma stable, and has improved solubility over our alternative probe ML278.

Benzo-fused lactams from a diversity-oriented synthesis (DOS) library as inhibitors of scavenger receptor BI (SR-BI)-mediated lipid uptake.

We report a new series of 8-membered benzo-fused lactams that inhibit cellular lipid uptake from HDL particles mediated by Scavenger Receptor, Class B, Type I (SR-BI). The series was identified via a high-throughput screen of the National Institutes of Health Molecular Libraries Small Molecule Repository (NIH MLSMR), measuring the transfer of the fluorescent lipid DiI from HDL particles to CHO cells overexpressing SR-BI. The series is part of a previously reported diversity-oriented synthesis (DOS) library prepared via a build-couple-pair approach. Detailed structure-activity relationship (SAR) studies were performed with a selection of the original library, as well as additional analogs prepared via solution phase synthesis. These studies demonstrate that the orientation of the substituents on the aliphatic ring have a critical effect on activity. Additionally, a lipophilic group is required at the western end of the molecule, and a northern hydroxyl group and a southern sulfonamide substituent also proved to be optimal. Compound 2p was found to possess a superior combination of potency (av IC50=0.10µM) and solubility (79µM in PBS), and it was designated as probe ML312.

Modulators of hepatic lipoprotein metabolism identified in a search for small-molecule inducers of tribbles pseudokinase 1 expression.

Recent genome wide association studies have linked tribbles pseudokinase 1 (TRIB1) to the risk of coronary artery disease (CAD). Based on the observations that increased expression of TRIB1 reduces secretion of VLDL and is associated with lower plasma levels of LDL cholesterol and triglycerides, higher plasma levels of HDL cholesterol and reduced risk for myocardial infarction, we carried out a high throughput phenotypic screen based on quantitative RT-PCR assay to identify compounds that induce TRIB1 expression in human HepG2 hepatoma cells. In a screen of a collection of diversity-oriented synthesis (DOS)-derived compounds, we identified a series of benzofuran-based compounds that upregulate TRIB1 expression and phenocopy the effects of TRIB1 cDNA overexpression, as they inhibit triglyceride synthesis and apoB secretion in cells. In addition, the compounds downregulate expression of MTTP and APOC3, key components of the lipoprotein assembly pathway. However, CRISPR-Cas9 induced chromosomal disruption of the TRIB1 locus in HepG2 cells, while confirming its regulatory role in lipoprotein metabolism, demonstrated that the effects of benzofurans persist in TRIB1-null cells indicating that TRIB1 is sufficient but not necessary to transmit the effects of the drug. Remarkably, active benzofurans, as well as natural products capable of TRIB1 upregulation, also modulate hepatic cell cholesterol metabolism by elevating the expression of LDLR transcript and LDL receptor protein, while reducing the levels of PCSK9 transcript and secreted PCSK9 protein and stimulating LDL uptake. The effects of benzofurans are not masked by cholesterol depletion and are independent of the SREBP-2 regulatory circuit, indicating that these compounds represent a novel class of chemically tractable small-molecule modulators that shift cellular lipoprotein metabolism in HepG2 cells from lipogenesis to scavenging.

Rates of adult acute inpatients documented as at risk of refeeding syndrome by dietitians.

BACKGROUND & AIMS: Identification of Refeeding Syndrome (RFS) is vital for prevention and treatment of metabolic disturbances, yet no information exists that describes identification rates by dietitians in acute care. We aimed to describe rates and demographics of inpatients identified by dietitians as at-risk of RFS and factors associated with electrolyte levels post-dietetic assessment. METHODS: Eligible participants were adult (≥ 18 yrs) acute care inpatients reviewed by dietitians between March 2012-February 2013 and not admitted to intensive care prior to first dietetic assessment. Patient information was sourced from medical charts. Chi-squared, t-tests and linear regression analyses were conducted. RESULTS: Of 1661 eligible inpatients (55%F, 65 ± 18 yrs), 9% (n = 151) were documented as at-risk of RFS in the first dietetic medical chart entry. On average, patients identified with RFS-risk had four days greater hospital stay, were 13 kg lighter, more likely classified SGA C (36% vs. 7%), and on a modified diet (52% vs. 35%) than non-RFS patients (p < 0.05). Very low and low electrolyte values occurred within seven days post-dietetic assessment in 7% and 52%, respectively, of inpatients with RFS-risk. Regression analysis showed that electrolyte supplementation was positively associated (ß = 0.145-0.594), and number of RFS-related risk factors negatively associated (ß = -0.044-0.122), with potassium, magnesium and phosphate levels within seven days post-dietetic assessment (p < 0.05). CONCLUSION: Nine percent of adult inpatients were documented as at-risk of RFS by dietitians. Identification of at-risk patients was in accordance with RFS guidelines. Electrolyte supplementation was positively associated with electrolyte levels post-assessment. Consistency of RFS-risk identification between dietitians requires determination.

Diversity-oriented synthesis-facilitated medicinal chemistry: toward the development of novel antimalarial agents.

Here, we describe medicinal chemistry that was accelerated by a diversity-oriented synthesis (DOS) pathway, and in vivo studies of our previously reported macrocyclic antimalarial agent that derived from the synthetic pathway. Structure-activity relationships that focused on both appendage and skeletal features yielded a nanomolar inhibitor of P. falciparum asexual blood-stage growth with improved solubility and microsomal stability and reduced hERG binding. The build/couple/pair (B/C/P) synthetic strategy, used in the preparation of the original screening library, facilitated medicinal chemistry optimization of the antimalarial lead.

Identification of a small molecule that increases hemoglobin oxygen affinity and reduces SS erythrocyte sickling.

Small molecules that increase the oxygen affinity of human hemoglobin may reduce sickling of red blood cells in patients with sickle cell disease. We screened 38,700 compounds using small molecule microarrays and identified 427 molecules that bind to hemoglobin. We developed a high-throughput assay for evaluating the ability of the 427 small molecules to modulate the oxygen affinity of hemoglobin. We identified a novel allosteric effector of hemoglobin, di(5-(2,3-dihydro-1,4-benzodioxin-2-yl)-4H-1,2,4-triazol-3-yl)disulfide (TD-1). TD-1 induced a greater increase in oxygen affinity of human hemoglobin in solution and in red blood cells than did 5-hydroxymethyl-2-furfural (5-HMF), N-ethylmaleimide (NEM), or diformamidine disulfide. The three-dimensional structure of hemoglobin complexed with TD-1 revealed that monomeric units of TD-1 bound covalently to ß-Cys93 and ß-Cys112, as well as noncovalently to the central water cavity of the hemoglobin tetramer. The binding of TD-1 to hemoglobin stabilized the relaxed state (R3-state) of hemoglobin. TD-1 increased the oxygen affinity of sickle hemoglobin and inhibited in vitro hypoxia-induced sickling of red blood cells in patients with sickle cell disease without causing hemolysis. Our study indicates that TD-1 represents a novel lead molecule for the treatment of patients with sickle cell disease.

Diversity-oriented synthesis yields a new drug lead for treatment of chagas disease.

A phenotypic high-throughput screen using ∼100,000 compounds prepared using Diversity-Oriented Synthesis yielded stereoisomeric compounds with nanomolar growth-inhibition activity against the parasite Trypanosoma cruzi, the etiological agent of Chagas disease. After evaluating stereochemical dependence on solubility, plasma protein binding and microsomal stability, the SSS analogue (5) was chosen for structure-activity relationship studies. The p-phenoxy benzyl group appended to the secondary amine could be replaced with halobenzyl groups without loss in potency. The exocyclic primary alcohol is not needed for activity but the isonicotinamide substructure is required for activity. Most importantly, these compounds are trypanocidal and hence are attractive as drug leads for both acute and chronic stages of Chagas disease. Analogue (5) was nominated as the molecular libraries probe ML341 and is available through the Molecular Libraries Probe Production Centers Network.