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1.
Cureus ; 15(10): e47543, 2023 Oct.
Article in English | MEDLINE | ID: mdl-38022286

ABSTRACT

Metastasis to the gastrointestinal (GI) tract should always be a consideration when melanoma, particularly metastatic disease, is diagnosed. While metastasis to the small intestine is common, given its rich blood supply, metastasis to the pancreatic ducts is extremely rare. In patients with pancreatic divisum, disease spread to the minor papilla can greatly increase the chance of developing pancreatitis due to the potential for increased pancreatic intraductal pressure. We present one unique case of metastatic melanoma to the minor duodenal papilla causing pancreatitis.

2.
JAMA ; 330(19): 1852-1861, 2023 11 21.
Article in English | MEDLINE | ID: mdl-37824112

ABSTRACT

Importance: Red blood cell (RBC) transfusion is common among patients admitted to the intensive care unit (ICU). Despite multiple randomized clinical trials of hemoglobin (Hb) thresholds for transfusion, little is known about how these thresholds are incorporated into current practice. Objective: To evaluate and describe ICU RBC transfusion practices worldwide. Design, Setting, and Participants: International, prospective, cohort study that involved 3643 adult patients from 233 ICUs in 30 countries on 6 continents from March 2019 to October 2022 with data collection in prespecified weeks. Exposure: ICU stay. Main Outcomes and Measures: The primary outcome was the occurrence of RBC transfusion during ICU stay. Additional outcomes included the indication(s) for RBC transfusion (consisting of clinical reasons and physiological triggers), the stated Hb threshold and actual measured Hb values before and after an RBC transfusion, and the number of units transfused. Results: Among 3908 potentially eligible patients, 3643 were included across 233 ICUs (median of 11 patients per ICU [IQR, 5-20]) in 30 countries on 6 continents. Among the participants, the mean (SD) age was 61 (16) years, 62% were male (2267/3643), and the median Sequential Organ Failure Assessment score was 3.2 (IQR, 1.5-6.0). A total of 894 patients (25%) received 1 or more RBC transfusions during their ICU stay, with a median total of 2 units per patient (IQR, 1-4). The proportion of patients who received a transfusion ranged from 0% to 100% across centers, from 0% to 80% across countries, and from 19% to 45% across continents. Among the patients who received a transfusion, a total of 1727 RBC transfusions were administered, wherein the most common clinical indications were low Hb value (n = 1412 [81.8%]; mean [SD] lowest Hb before transfusion, 7.4 [1.2] g/dL), active bleeding (n = 479; 27.7%), and hemodynamic instability (n = 406 [23.5%]). Among the events with a stated physiological trigger, the most frequently stated triggers were hypotension (n = 728 [42.2%]), tachycardia (n = 474 [27.4%]), and increased lactate levels (n = 308 [17.8%]). The median lowest Hb level on days with an RBC transfusion ranged from 5.2 g/dL to 13.1 g/dL across centers, from 5.3 g/dL to 9.1 g/dL across countries, and from 7.2 g/dL to 8.7 g/dL across continents. Approximately 84% of ICUs administered transfusions to patients at a median Hb level greater than 7 g/dL. Conclusions and Relevance: RBC transfusion was common in patients admitted to ICUs worldwide between 2019 and 2022, with high variability across centers in transfusion practices.


Subject(s)
Anemia , Transfusion Medicine , Adult , Humans , Male , Middle Aged , Female , Erythrocyte Transfusion/adverse effects , Erythrocyte Transfusion/statistics & numerical data , Cohort Studies , Prospective Studies , Hemoglobins , Intensive Care Units/statistics & numerical data
4.
Adv Exp Med Biol ; 1414: 1-26, 2023.
Article in English | MEDLINE | ID: mdl-35708844

ABSTRACT

Three human nucleases, SNM1A, SNM1B/Apollo, and SNM1C/Artemis, belong to the SNM1 gene family. These nucleases are involved in various cellular functions, including homologous recombination, nonhomologous end-joining, cell cycle regulation, and telomere maintenance. These three proteins share a similar catalytic domain, which is characterized as a fused metallo-ß-lactamase and a CPSF-Artemis-SNM1-PSO2 domain. SNM1A and SNM1B/Apollo are exonucleases, whereas SNM1C/Artemis is an endonuclease. This review contains a summary of recent research on SNM1's cellular and biochemical functions, as well as structural biology studies. In addition, protein structure prediction by the artificial intelligence program AlphaFold provides a different view of the proteins' non-catalytic domain features, which may be used in combination with current results from X-ray crystallography and cryo-EM to understand their mechanism more clearly.


Subject(s)
DNA Repair Enzymes , DNA Repair , Humans , Artificial Intelligence , DNA Repair Enzymes/genetics , DNA Repair Enzymes/metabolism , Endonucleases/genetics , Endonucleases/metabolism , Exodeoxyribonucleases/genetics , Exodeoxyribonucleases/metabolism , Nuclear Proteins/metabolism , Cell Cycle Proteins/metabolism
5.
Crit Care Resusc ; 25(4): 193-200, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38234319

ABSTRACT

Objective: To describe current transfusion practices in intensive care units (ICUs) in Australia and New Zealand, compare them against national guidelines, and describe how viscoelastic haemostatic assays (VHAs) are used in guiding transfusion decisions. Design setting and participants: Prospective, multicentre, binational point-prevalence study. All adult patients admitted to participating ICUs on a single day in 2021. Main outcome measures: Transfusion types, amounts, clinical reasons, and triggers; use of anti-platelet medications, anti-coagulation, and VHA. Results: Of 712 adult patients in 51 ICUs, 71 (10%) patients received a transfusion during the 24hr period of observation. Compared to patients not transfused, these patients had higher Acute Physiology and Chronic Health Evaluation II scores (19 versus 17, p = 0.02), a greater proportion were mechanically ventilated (49.3% versus 37.3%, p < 0.05), and more had systemic inflammatory response syndrome (70.4% versus 51.3%, p < 0.01). Overall, 63 (8.8%) patients received red blood cell (RBC) transfusions, 10 (1.4%) patients received platelet transfusions, 6 (0.8%) patients received fresh frozen plasma (FFP), and 5 (0.7%) patients received cryoprecipitate. VHA was available in 42 (82.4%) sites but only used in 6.6% of transfusion episodes when available. Alignment with guidelines was found for 98.6% of RBC transfusions, but only 61.6% for platelet, 28.6% for FFP, and 20% for cryoprecipitate transfusions. Conclusions: Non-RBC transfusion decisions are often not aligned with guidelines and VHA is commonly available but rarely used to guide transfusions. Better evidence to guide transfusions in ICUs is needed.

6.
DNA Repair (Amst) ; 120: 103422, 2022 12.
Article in English | MEDLINE | ID: mdl-36332285

ABSTRACT

Artemis is a 692 aa nuclease that is essential for opening hairpins during vertebrate V(D)J recombination. Artemis is also important in the DNA repair of double-strand breaks via the nonhomologous DNA end joining (NHEJ) pathway. Therefore, absence of Artemis has been shown to result not only in the blockage of lymphocyte development in vertebrates, but also sensitivity of organisms and cells to double-strand break-inducing events that arise in the course of normal metabolism. Nonhomologous DNA end joining (NHEJ) is the major pathway for the repair of double-strand DNA breaks in most vertebrate cells during most of the cell cycle, including in resting cells. Artemis is the primary nuclease for resection of damaged DNA at double-strand breaks. Artemis alone is inactive as an endonuclease, though it has 5'-exonuclease activity. The endonuclease activity requires physical interaction with DNA-PKcs and subsequent activation steps. Truncation of the C-terminal half of Artemis permits Artemis to be active, even without DNA-PKcs. Here we create a systematic set of deletions from the Artemis C-terminus to determine the minimal extent of C-terminal deletion for Artemis to function in a DNA-PKcs-independent manner. We discuss these data in the context of recent structural studies. The results will be useful in future studies to determine the full range of functions of the C-terminal region of Artemis in the regulation of its endonuclease activity.


Subject(s)
DNA-Binding Proteins , Nuclear Proteins , Animals , DNA-Binding Proteins/metabolism , Nuclear Proteins/metabolism , DNA-Activated Protein Kinase/metabolism , Endonucleases/metabolism , DNA End-Joining Repair , DNA Repair , DNA/metabolism
7.
Cureus ; 14(6): e26153, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35747109

ABSTRACT

Suspicion for soft tissue malignancy of the hand is usually low because most tumors of the hand are small and benign. We present a case of an elderly female who presented with a rapidly enlarging, ulcerating hand mass over a few months. She was diagnosed with undifferentiated pleomorphic sarcoma (UPS), a high-grade, aggressive soft-tissue sarcoma. Computed tomography (CT) of the chest was conducted for staging purposes. It showed multiple subcentimeter pulmonary nodules, findings that were initially worrisome for metastatic disease but later proved to be newly and incidentally diagnosed granulomatous disease of the lungs. This case highlights the importance of early recognition of potential malignancy in soft-tissue tumors of the hand to facilitate proper referral and initiation of appropriate oncologic therapies. Due to early diagnosis and intervention, our patient had locally advanced disease without metastasis, a type of cancer known to have a high degree of metastatic potential.

8.
Cureus ; 13(11): e19491, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34912632

ABSTRACT

Unilateral adrenal infarction is a rare cause of acute abdomen in pregnancy (AAP). Its presentation is non-specific and requires a high index of suspicion with a low threshold to obtain radiographic imaging for diagnosis. Evaluating AAP is challenging as diagnostic radiographic imaging is often limited in relation to radiation exposure to the developing fetus. We describe a case of a 24-year-old pregnant female who presented with severe acute abdominal pain. The patient's pain was refractory to intravenous analgesics and ultrasonography was inconclusive. Computed tomography (CT) scan was not obtained due to the risk of radiation exposure to the developing fetus. Due to the persistence of pain and suspicions for other serious etiologies, magnetic resonance imaging (MRI) was completed and the patient was diagnosed with acute unilateral adrenal infarction. In this case report, unilateral adrenal infarction was likely secondary to elevated plasma factor VIII levels. Even with the physiological elevation of factor VIII levels during pregnancy, levels greater than 150 IU/dL confer greater than five-fold increased risk of venous thrombosis. Once hemorrhage is excluded, patients should be started on therapeutic anticoagulation to prevent progression of adrenal infarct or infarction of the contralateral adrenal gland. Prompt recognition and treatment of acute adrenal infarction during pregnancy are of paramount importance to prevent adverse outcomes for both the mother and fetus.

9.
Transfus Med Rev ; 35(4): 73-79, 2021 10.
Article in English | MEDLINE | ID: mdl-34690031

ABSTRACT

While massive transfusion (MT) recipients account for a small proportion of all transfused patients, they account for approximately 10% of blood products issued. Furthermore, MT events pose organizational and logistical challenges for health care providers, laboratory and transfusion services. Overall, the majority of MT events are to support major bleeding in surgical patients, trauma and gastrointestinal hemorrhage. The clinical context in which the bleeding event occurred, the number of blood products required, patient age and comorbidities are the most important predictors of outcomes for short- and long-term survival. These data are important to inform blood services, clinicians and health care providers in order to improve care and outcomes for patients with major bleeding. There is no standard accepted definition of MT, with most definitions based on number of blood components administered within a certain time-period or activation of MT protocol. The type of definition used has implications for the clinical characteristics of MT recipients included in epidemiological and interventional studies. In order to understand trends in incidence of MT, variation in blood utilization and patient outcomes, and to harmonize research outcomes, a standard and universally accepted definition of MT is urgently required.


Subject(s)
Blood Transfusion , Wounds and Injuries , Blood Component Transfusion , Comorbidity , Hemorrhage/epidemiology , Humans , Incidence
10.
Structure ; 29(8): 873-885.e5, 2021 08 05.
Article in English | MEDLINE | ID: mdl-33784495

ABSTRACT

Taspase1 is an Ntn-hydrolase overexpressed in primary human cancers, coordinating cancer cell proliferation, invasion, and metastasis. Loss of Taspase1 activity disrupts proliferation of human cancer cells in vitro and in mouse models of glioblastoma. Taspase1 is synthesized as an inactive proenzyme, becoming active upon intramolecular cleavage. The activation process changes the conformation of a long fragment at the C-terminus of the α subunit, for which no full-length structural information exists and whose function is poorly understood. We present a cloning strategy to generate a circularly permuted form of Taspase1 to determine the crystallographic structure of active Taspase1. We discovered that this region forms a long helix and is indispensable for the catalytic activity of Taspase1. Our study highlights the importance of this element for the enzymatic activity of Ntn-hydrolases, suggesting that it could be a potential target for the design of inhibitors with potential to be developed into anticancer therapeutics.


Subject(s)
Endopeptidases/chemistry , Endopeptidases/metabolism , Cloning, Molecular , Crystallography, X-Ray , Dynamic Light Scattering , Endopeptidases/genetics , Enzyme Activation , Humans , Models, Molecular , Protein Domains , Protein Structure, Secondary
11.
Bioorg Med Chem Lett ; 41: 127974, 2021 06 01.
Article in English | MEDLINE | ID: mdl-33771585

ABSTRACT

Lactate dehydrogenase (LDH) is a critical enzyme in the glycolytic metabolism pathway that is used by many tumor cells. Inhibitors of LDH may be expected to inhibit the metabolic processes in cancer cells and thus selectively delay or inhibit growth in transformed versus normal cells. We have previously disclosed a pyrazole-based series of potent LDH inhibitors with long residence times on the enzyme. Here, we report the elaboration of a new subseries of LDH inhibitors based on those leads. These new compounds potently inhibit both LDHA and LDHB enzymes, and inhibit lactate production in cancer cell lines.


Subject(s)
Aniline Compounds/pharmacology , Antineoplastic Agents/pharmacology , Drug Design , Ethers/pharmacology , L-Lactate Dehydrogenase/antagonists & inhibitors , L-Lactate Dehydrogenase/metabolism , Aniline Compounds/chemistry , Antineoplastic Agents/chemistry , Cell Line, Tumor , Ethers/chemistry , Humans , L-Lactate Dehydrogenase/chemistry
12.
J Med Chem ; 63(19): 10984-11011, 2020 10 08.
Article in English | MEDLINE | ID: mdl-32902275

ABSTRACT

Lactate dehydrogenase (LDH) catalyzes the conversion of pyruvate to lactate, with concomitant oxidation of reduced nicotinamide adenine dinucleotide as the final step in the glycolytic pathway. Glycolysis plays an important role in the metabolic plasticity of cancer cells and has long been recognized as a potential therapeutic target. Thus, potent, selective inhibitors of LDH represent an attractive therapeutic approach. However, to date, pharmacological agents have failed to achieve significant target engagement in vivo, possibly because the protein is present in cells at very high concentrations. We report herein a lead optimization campaign focused on a pyrazole-based series of compounds, using structure-based design concepts, coupled with optimization of cellular potency, in vitro drug-target residence times, and in vivo PK properties, to identify first-in-class inhibitors that demonstrate LDH inhibition in vivo. The lead compounds, named NCATS-SM1440 (43) and NCATS-SM1441 (52), possess desirable attributes for further studying the effect of in vivo LDH inhibition.


Subject(s)
Enzyme Inhibitors/pharmacology , L-Lactate Dehydrogenase/antagonists & inhibitors , Pyrazoles/pharmacology , Animals , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacokinetics , Half-Life , Humans , Mice , Structure-Activity Relationship , Xenograft Model Antitumor Assays
13.
Transfusion ; 60(10): 2272-2283, 2020 10.
Article in English | MEDLINE | ID: mdl-32757209

ABSTRACT

Platelet (PLT) transfusions are limited and costly resources. Accurately predicting clinical demand while limiting product wastage remains difficult. A PLT transfusion prediction score was developed for use in cardiac surgery patients who commonly require PLT transfusions. STUDY DESIGN AND METHODS: Using the Australian and New Zealand Society of Cardiac and Thoracic Surgeons National Cardiac Surgery Database, significant predictors for PLT transfusion were identified by multivariate logistic regression. Using a development data set containing 2005 to 2016 data, the Australian Cardiac Surgery Platelet Transfusion (ACSePT) risk prediction tool was developed by assigning weights to each significant predictor that corresponded to a probability of PLT transfusion. The predicted probability for each score was compared to actual PLT transfusion occurrence in a validation (2017) data set. RESULTS: The development data set contained 38 independent variables and 91 521 observations. The validation data set contained 12 529 observations. The optimal model contained 23 variables significant at P < .001 and an area under the receiver operating characteristic (ROC) curve of 0.69 (95% confidence interval [CI], 0.68-0.69). ACSePT contained nine variables and had an area under the ROC curve of 0.66 (95% CI, 0.65-0.66) and overall predicted probability of PLT transfusion of 19.8% for the validation data set compared to an observed risk of 20.3%. CONCLUSION: The ACSePT risk prediction tool is the first scoring system to predict a cardiac surgery patient's risk of receiving a PLT transfusion. It can be used to identify patients at higher risk of receiving PLT transfusions for inclusion in clinical trials and by PLT inventory managers to predict PLT demand.


Subject(s)
Cardiac Surgical Procedures , Databases, Factual , Platelet Transfusion , Australia , New Zealand , Predictive Value of Tests , Retrospective Studies , Risk Assessment , Risk Factors , Societies, Medical , Thoracic Surgery
14.
Health Equity ; 4(1): 190-197, 2020.
Article in English | MEDLINE | ID: mdl-32440616

ABSTRACT

Introduction: The social impact of inflammatory bowel disease (IBD) on student transition to college is significant, yet poorly understood. Methods: Two 90-min focus groups (FGs) were conducted with eight student-patients with IBD. Reflective journals were used to corroborate, elaborate, or challenge emergent FG findings. Results: Six themes emerged: (1) transitioning to college, (2) interacting with physicians, (3) affecting social life, (4) managing the disease by yourself and through support, (5) coping strategies, and (6) facing disease challenges. These themes remained relevant in the reflective writings. Analysis of serial journal entries showed that students' social life and engagement in coursework was affected 66% and 54% of the time, respectively. Conclusion: Our findings offer guidance for improving students' college success, quality of care, and enhancing physician-patient interactions. Students with IBD have a disability that may not be obvious or visible. They require specific support to help them transition and succeed in college.

15.
ChemMedChem ; 15(8): 685-694, 2020 04 20.
Article in English | MEDLINE | ID: mdl-32162487

ABSTRACT

A major challenge of targeted cancer therapy is the selection for drug-resistant mutations in tumor cells leading to loss of treatment effectiveness. p97/VCP is central regulator of protein homeostasis and a promising anticancer target because of its vital role in cell growth and survival. One ATP-competitive p97 inhibitor, CB-5083, has entered clinical trials. Selective pressure on HCT116 cells dosed with CB-5083 identified five different resistant mutants. Identification of p97 inhibitors with different mechanisms of action would offer the potential to overcome this class of resistance mutations. Our results demonstrate that two CB-5083 resistant p97 mutants, N660 K and T688 A, were also resistant to several other ATP-competitive p97 inhibitors, whereas inhibition by two allosteric p97 inhibitors NMS-873 and UPCDC-30245 were unaffected by these mutations. We also established a CB-5083 resistant cell line that harbors a new p97 double mutation (D649 A/T688 A). While CB-5083, NMS-873, and UPCDC-30245 all effectively inhibited proliferation of the parental HCT116 cell line, NMS-873 and UPCDC-30245 were 30-fold more potent in inhibiting the CB-5083 resistant D649 A/T688 A double mutant than CB-5083. Our results suggest that allosteric p97 inhibitors are promising alternatives when resistance to ATP-competitive p97 inhibitors arises during anticancer treatment.


Subject(s)
Acetanilides/pharmacology , Adenosine Triphosphatases/antagonists & inhibitors , Antineoplastic Agents/pharmacology , Benzothiazoles/pharmacology , Enzyme Inhibitors/pharmacology , Indoles/pharmacology , Nuclear Proteins/antagonists & inhibitors , Pyrimidines/pharmacology , Acetanilides/chemistry , Adenosine Triphosphatases/genetics , Adenosine Triphosphatases/metabolism , Adenosine Triphosphate/metabolism , Allosteric Regulation/drug effects , Antineoplastic Agents/chemistry , Benzothiazoles/chemistry , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Resistance, Neoplasm/drug effects , Drug Screening Assays, Antitumor , Enzyme Inhibitors/chemistry , HCT116 Cells , Humans , Indoles/chemistry , Models, Molecular , Molecular Structure , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Pyrimidines/chemistry
16.
Transfus Med Rev ; 34(1): 42-50, 2020 01.
Article in English | MEDLINE | ID: mdl-31685352

ABSTRACT

Current platelet concentrates are perishable blood products with short shelf lives. Combined with often unpredictable demand, this results in platelet inventory management problems, manifested by high rates of outdating frequently reported at 10% to 20%, and sometimes inadequate clinical supply. The objective of this study was to critically review the published methodologies on measures to reduce platelet outdating rates, in order to determine how platelet outdating and availability can be improved. We performed a systematic review of journal articles published in English to May 2019 identified from MEDLINE, with reported methods to improve platelet inventory outdating rates and availability. The complexity of each methodology was scored based on whether a typical blood bank manager could design, implement and run a platelet outdating program based on the methodology. Twenty-four relevant citations were found-these included 8 citations employing operational research (OR) methodologies, 7 evaluation/best practice, 6 simulation and 3 forecasting. Over half the included studies have been published within the last decade. The citations reporting the lowest predicted outdating were also the most complex methods. Overall predicted outdating and shortages were less than 4% based on the available data. In conclusion, we found that research interest in platelet inventory management problems has increased in line with platelet demand and methods to assist in reducing outdating rates without increased shortages have been available now for 4 decades; high rates of platelet outdating do however continue to be reported around the world. Developments in platelet preparation and storage, and other new approaches, may assist in addressing this problem.


Subject(s)
Blood Platelets/cytology , Blood Platelets/physiology , Blood Preservation/standards , Drug Stability , Blood Banks/organization & administration , Blood Banks/standards , Blood Component Removal/adverse effects , Blood Component Removal/methods , Blood Preservation/methods , Computer Simulation , Humans , Time Factors
17.
Crit Care ; 22(1): 185, 2018 08 05.
Article in English | MEDLINE | ID: mdl-30077181

ABSTRACT

BACKGROUND: Platelets (PLTs) are usually stored for up to 5 days prior to transfusion, although in some blood services the storage period is extended to 7 days. During storage, changes occur in both PLT and storage medium, which may lead to PLT activation and dysfunction. The clinical significance of these changes remains uncertain. METHODS: We performed a systematic review to assess the association between PLT storage time and clinical or transfusion outcomes in patients receiving allogeneic PLT transfusion. We searched studies published in English between January 2000 and July 2017 identified from MEDLINE, Embase, PubMed and the Cochrane Libraries. RESULTS: Of the 18 studies identified, five included 4719 critically ill patients (trauma, post-cardiac surgery and a heterogeneous population of critically ill patients) and 13 included 8569 haematology patients. The five studies in critically ill patients were retrospective and did not find any association between PLT storage time when PLTs were stored for up to 5 days and mortality. There was also no association between older PLTs and sepsis in the two largest studies (n = 4008 patients). Of the 13 studies in haematology patients, seven analysed prolonged storage time up to 6.5 or 7 days. Administration of fresh PLTs (less than 2 or 3 days) was associated with a significant increase in corrected count increment (CCI) compared to older PLTs in seven of the eight studies analysing this outcome. One single centre retrospective study found an increase in bleeding events in patients receiving older PLTs. CONCLUSIONS: PLT storage time does not appear to be associated with clinical outcomes, including bleeding, sepsis or mortality, in critically ill patients or haematology patients. The freshest PLTs (less than 3 days) were associated with a better CCI, although there was no impact on bleeding events, questioning the clinical significance of this association. However, there is an absence of evidence to draw definitive conclusions, especially in critically ill patients.


Subject(s)
Blood Platelets/pathology , Drug Storage/standards , Platelet Transfusion/standards , Treatment Outcome , Blood Platelets/physiology , Critical Illness/therapy , Drug Storage/methods , Humans , Platelet Transfusion/methods
18.
J Med Chem ; 61(16): 7358-7373, 2018 08 23.
Article in English | MEDLINE | ID: mdl-30048132

ABSTRACT

The L-type amino acid transporter 1 (LAT1, SLC7A5) transports essential amino acids across the blood-brain barrier (BBB) and into cancer cells. To utilize LAT1 for drug delivery, potent amino acid promoieties are desired, as prodrugs must compete with millimolar concentrations of endogenous amino acids. To better understand ligand-transporter interactions that could improve potency, we developed structural LAT1 models to guide the design of substituted analogues of phenylalanine and histidine. Furthermore, we evaluated the structure-activity relationship (SAR) for both enantiomers of naturally occurring LAT1 substrates. Analogues were tested in cis-inhibition and trans-stimulation cell assays to determine potency and uptake rate. Surprisingly, LAT1 can transport amino acid-like substrates with wide-ranging polarities including those containing ionizable substituents. Additionally, the rate of LAT1 transport was generally nonstereoselective even though enantiomers likely exhibit different binding modes. Our findings have broad implications to the development of new treatments for brain disorders and cancer.


Subject(s)
Large Neutral Amino Acid-Transporter 1/chemistry , Large Neutral Amino Acid-Transporter 1/metabolism , Structure-Activity Relationship , Amino Acid Transport Systems/chemistry , Amino Acid Transport Systems/metabolism , Antiporters/chemistry , Antiporters/metabolism , Escherichia coli Proteins/chemistry , Escherichia coli Proteins/metabolism , HEK293 Cells , Humans , Large Neutral Amino Acid-Transporter 1/genetics , Ligands , Molecular Docking Simulation , Phenylalanine/chemistry , Phenylalanine/metabolism , Stereoisomerism , Structural Homology, Protein , Substrate Specificity
19.
Abdom Radiol (NY) ; 43(7): 1798-1806, 2018 07.
Article in English | MEDLINE | ID: mdl-29075825

ABSTRACT

PURPOSE: The purpose of the article is to compare information regarding small bowel lesions in Crohn's disease (CD) patients communicated by a published scoring system and radiology reports from electronic medical record (EMR) of cross-sectional abdominal imaging. METHODS: Two gastrointestinal radiologists (reference readers) blinded to EMR reports scored cross-sectional imaging exams using a published scoring system. Investigators compared EMR and radiologist scores based on the mentioned findings and severity documentation of each variable. Statistical analysis involved means and difference in proportions and logistic regression modeling. RESULTS: Seventy-three CD patients, with average age 40.6 years (± SD 14.4), having 80 small bowel lesions on imaging were included. EMR reports reliably mentioned within the consensus score included thickness (79%, p = 0.000), enhancement (70%, p = 0.000), active inflammation (86%, p = 0.000), perienteric fluid (82%, p = 0.000), and presence of stricture (62%, p = 0.002). Minimal lumen diameter (19%, p = 0.000), comb sign (19%, p = 0.000), lesion length (57%, p = 0.06), and fistula (50%, p = 1.0) were reported less often. There was a strong association between the EMR and scoring scale in noting severity of active inflammation (88%, p = 0.000), perienteric fluid (76%, p = 0.000), and internal fistula (71%, p = 0.000). The proportion matching severity values of comb sign and minimal lumen were 24% and 21%, respectively (p = 0.000). Severity matches for stricture were less likely among the non-GI radiologists (odds ratio = 0.33, SE = 0.168, p = 0.029). The odds of reporting stricture and fistula severity were 3.6 and 5.7, respectively, on MRE. CONCLUSIONS: Findings and severity of inflammation were communicated consistently. Stricture severity including minimal luminal diameter, was less reliably reported, though its prognostic significance impacts management.


Subject(s)
Crohn Disease/diagnosis , Electronic Health Records/statistics & numerical data , Intestine, Small/diagnostic imaging , Magnetic Resonance Imaging/methods , Tomography, X-Ray Computed/methods , Adolescent , Adult , Aged , Constriction, Pathologic , Crohn Disease/complications , Crohn Disease/diagnostic imaging , Cross-Sectional Studies , Female , Humans , Inflammation/complications , Inflammation/diagnosis , Male , Middle Aged , Observer Variation , Reproducibility of Results , Retrospective Studies , Severity of Illness Index , Young Adult
20.
J Med Chem ; 60(22): 9184-9204, 2017 11 22.
Article in English | MEDLINE | ID: mdl-29120638

ABSTRACT

We report the discovery and medicinal chemistry optimization of a novel series of pyrazole-based inhibitors of human lactate dehydrogenase (LDH). Utilization of a quantitative high-throughput screening paradigm facilitated hit identification, while structure-based design and multiparameter optimization enabled the development of compounds with potent enzymatic and cell-based inhibition of LDH enzymatic activity. Lead compounds such as 63 exhibit low nM inhibition of both LDHA and LDHB, submicromolar inhibition of lactate production, and inhibition of glycolysis in MiaPaCa2 pancreatic cancer and A673 sarcoma cells. Moreover, robust target engagement of LDHA by lead compounds was demonstrated using the cellular thermal shift assay (CETSA), and drug-target residence time was determined via SPR. Analysis of these data suggests that drug-target residence time (off-rate) may be an important attribute to consider for obtaining potent cell-based inhibition of this cancer metabolism target.


Subject(s)
Enzyme Inhibitors/pharmacology , L-Lactate Dehydrogenase/antagonists & inhibitors , Pyrazoles/pharmacology , Thiazoles/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Crystallography, X-Ray , Drug Discovery , Drug Screening Assays, Antitumor , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacokinetics , High-Throughput Screening Assays , Humans , Male , Membranes, Artificial , Mice , Microsomes, Liver/drug effects , Permeability , Pyrazoles/chemical synthesis , Pyrazoles/chemistry , Pyrazoles/pharmacokinetics , Rats , Solubility , Structure-Activity Relationship , Thiazoles/chemical synthesis , Thiazoles/chemistry , Thiazoles/pharmacokinetics
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