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1.
Cancers (Basel) ; 16(5)2024 Feb 21.
Article in English | MEDLINE | ID: mdl-38473224

ABSTRACT

The concept and policies of multicancer early detection (MCED) have gained significant attention from governments worldwide in recent years. In the era of burgeoning artificial intelligence (AI) technology, the integration of MCED with AI has become a prevailing trend, giving rise to a plethora of MCED AI products. However, due to the heterogeneity of both the detection targets and the AI technologies, the overall diversity of MCED AI products remains considerable. The types of detection targets encompass protein biomarkers, cell-free DNA, or combinations of these biomarkers. In the development of AI models, different model training approaches are employed, including datasets of case-control studies or real-world cancer screening datasets. Various validation techniques, such as cross-validation, location-wise validation, and time-wise validation, are used. All of the factors show significant impacts on the predictive efficacy of MCED AIs. After the completion of AI model development, deploying the MCED AIs in clinical practice presents numerous challenges, including presenting the predictive reports, identifying the potential locations and types of tumors, and addressing cancer-related information, such as clinical follow-up and treatment. This study reviews several mature MCED AI products currently available in the market, detecting their composing factors from serum biomarker detection, MCED AI training/validation, and the clinical application. This review illuminates the challenges encountered by existing MCED AI products across these stages, offering insights into the continued development and obstacles within the field of MCED AI.

2.
Comput Biol Med ; 144: 105362, 2022 05.
Article in English | MEDLINE | ID: mdl-35299045

ABSTRACT

BACKGROUND: Machine learning (ML) has emerged as a superior method for the analysis of large datasets. Application of ML is often hindered by incompleteness of the data which is particularly evident when approaching disease screening data due to varied testing regimens across medical institutions. Here we explored the utility of multiple ML algorithms to predict cancer risk when trained using a large but incomplete real-world dataset of tumor marker (TM) values. METHODS: TM screening data were collected from a large asymptomatic cohort (n = 163,174) at two independent medical centers. The cohort included 785 individuals who were subsequently diagnosed with cancer. Data included levels of up to eight TMs, but for most subjects, only a subset of the biomarkers were tested. In some instances, TM values were available at multiple time points, but intervals between tests varied widely. The data were used to train and test various machine learning models to evaluate their robustness for predicting cancer risk. Multiple methods for data imputation were explored and models were developed for both single time-point as well as time-series data. RESULTS: The ML algorithm, long short-term memory (LSTM), demonstrated superiority over other models for dealing with irregular medical data. A cancer risk prediction tool was trained and validated for a single time-point test of a TM panel including up to four biomarkers (AUROC = 0.831, 95% CI: 0.827-0.835) which outperformed a single threshold method using the same biomarkers. A second model relying on time series data of up to four time-points for 5 TMs had an AUROC of 0.931. CONCLUSIONS: A cancer risk prediction tool was developed by training a LSTM model using a large but incomplete real-world dataset of TM values. The LSTM model was best able to handle irregular data compared to other ML models. The use of time-series TM data can further improve the predictive performance of LSTM models even when the intervals between tests vary widely. These risk prediction tools are useful to direct subjects to further screening sooner, resulting in earlier detection of occult tumors.


Subject(s)
Deep Learning , Neoplasms , Biomarkers, Tumor , Humans , Machine Learning , Memory, Short-Term , Neoplasms/diagnosis
3.
Front Oncol ; 11: 783744, 2021.
Article in English | MEDLINE | ID: mdl-35004304

ABSTRACT

BACKGROUND: Aspartate ß-hydroxylase (ASPH) is an embryonic transmembrane protein aberrantly upregulated in cancer cells, associated with malignant transformation and, in some reports, with poor clinical prognosis. OBJECTIVE: To report the expression patterns of ASPH in acute myeloid leukemia (AML). METHODS: Cell surface expression of ASPH was measured via 8-color multiparameter flow cytometry in 41 AML patient samples (31 bone marrow, 10 blood) using fluorescein isothiocyanate (FITC)-conjugated anti-ASPH antibody, SNS-622. A mean fluorescent intensity (MFI) of 10 was used as a cutoff for ASPH surface expression positivity. Data regarding patient and disease characteristics were collected. RESULTS: ASPH surface expression was found on AML blasts in 16 samples (39%). Higher ASPH expression was seen in myeloblasts of African American patients (p=0.02), but no correlation was found between ASPH expression and other patient or disease characteristics. No association was found between ASPH status and CR rate (p=0.53), EFS (p=0.87), or OS (p=0.17). CONCLUSIONS: ASPH is expressed on blasts in approximately 40% of AML cases, and may serve as a new therapeutically targetable leukemia-associated antigen.

4.
Front Genet ; 11: 605, 2020.
Article in English | MEDLINE | ID: mdl-32719714

ABSTRACT

BACKGROUND: Duchenne muscular dystrophy (DMD) is a rare and severe X-linked muscular dystrophy in which the standard of care with variable outcome, also due to different drug response, is chronic off-label treatment with corticosteroids (CS). In order to search for SNP biomarkers for corticosteroid responsiveness, we genotyped variants across 205 DMD-related genes in patients with differential response to steroid treatment. METHODS AND FINDINGS: We enrolled a total of 228 DMD patients with identified dystrophin mutations, 78 of these patients have been under corticosteroid treatment for at least 5 years. DMD patients were defined as high responders (HR) if they had maintained the ability to walk after 15 years of age and low responders (LR) for those who had lost ambulation before the age of 10 despite corticosteroid therapy. Based on interactome mapping, we prioritized 205 genes and sequenced them in 21 DMD patients (discovery cohort or DiC = 21). We identified 43 SNPs that discriminate between HR and LR. Discriminant Analysis of Principal Components (DAPC) prioritized 2 response-associated SNPs in the TNFRSF10A gene. Validation of this genotype was done in two additional larger cohorts composed of 46 DMD patients on corticosteroid therapy (validation cohorts or VaC1), and 150 non ambulant DMD patients and never treated with corticosteroids (VaC2). SNP analysis in all validation cohorts (N = 207) showed that the CT haplotype is significantly associated with HR DMDs confirming the discovery results. CONCLUSION: We have shown that TNFRSF10A CT haplotype correlates with corticosteroid response in DMD patients and propose it as an exploratory CS response biomarker.

5.
Cancers (Basel) ; 12(6)2020 Jun 01.
Article in English | MEDLINE | ID: mdl-32492934

ABSTRACT

BACKGROUND: Tumor markers are used to screen tens of millions of individuals worldwide at annual health check-ups, especially in East Asia. Machine learning (ML)-based algorithms that improve the diagnostic accuracy and clinical utility of these tests can have substantial impact leading to the early diagnosis of cancer. METHODS: ML-based algorithms, including a cancer screening algorithm and a secondary organ of origin algorithm, were developed and validated using a large real world dataset (RWD) from asymptomatic individuals undergoing routine cancer screening at a Taiwanese medical center between May 2001 and April 2015. External validation was performed using data from the same period from a separate medical center. The data set included tumor marker values, age, and gender from 27,938 individuals, including 342 subsequently confirmed cancer cases. RESULTS: Separate gender-specific cancer screening algorithms were developed. For men, a logistic regression-based algorithm outperformed single-marker and other ML-based algorithms, with a mean area under the receiver operating characteristic curve (AUROC) of 0.7654 in internal and 0.8736 in external cross validation. For women, a random forest-based algorithm attained a mean AUROC of 0.6665 in internal and 0.6938 in external cross validation. The median time to cancer diagnosis (TTD) in men was 451.5, 204.5, and 28 days for the mild, moderate, and high-risk groups, respectively; for women, the median TTD was 229, 132, and 125 days for the mild, moderate, and high-risk groups. A second algorithm was developed to predict the most likely affected organ systems for at-risk individuals. The algorithm yielded 0.8120 sensitivity and 0.6490 specificity for men, and 0.8170 sensitivity and 0.6750 specificity for women. CONCLUSIONS: ML-derived algorithms, trained and validated by using a RWD, can significantly improve tumor marker-based screening for multiple types of early stage cancers, suggest the tissue of origin, and provide guidance for patient follow-up.

6.
Cancer Lett ; 449: 87-98, 2019 05 01.
Article in English | MEDLINE | ID: mdl-30768955

ABSTRACT

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive malignancy with very limited treatment options. Antibody drug conjugates (ADCs) are promising cytotoxic agents capable of highly selective delivery. Aspartate-ß-hydroxylase (ASPH) is a type II transmembrane protein highly expressed in PDACs (97.1%) but not normal pancreas. We investigated anti-tumor effects of an ADC guided by a human monoclonal antibody (SNS-622) against ASPH in human PDAC cell lines and derived subcutaneous (s.c.) xenograft as well as a patient-derived xenograft (PDX) murine model with spontaneous pulmonary metastasis. The cytotoxic effects exhibited by several candidate payloads linked to SNS-622 antibody targeting ASPH+ PDACs were analyzed. After i.v. administration of SNS-622-emtansine (DM1) ADC, the primary PDAC tumor growth and progression (number and size of pulmonary metastases) were determined. The PDAC cell lines, s.c. and PDX tumors treated with ADC were tested for cell proliferation, cytotoxicity and apoptosis by MTS and immunohistochemistry (IHC) assays. SNS-622-DM1 construct has demonstrated optimal anti-tumor effects in vitro. In the PDX model of human PDAC, SNS-622-DM1 ADC exerted substantially inhibitory effects on tumor growth and pulmonary metastasis through attenuating proliferation and promoting apoptosis.


Subject(s)
Calcium-Binding Proteins/antagonists & inhibitors , Carcinoma, Pancreatic Ductal/drug therapy , Immunoconjugates/administration & dosage , Lung Neoplasms/drug therapy , Lung Neoplasms/secondary , Membrane Proteins/antagonists & inhibitors , Mixed Function Oxygenases/antagonists & inhibitors , Muscle Proteins/antagonists & inhibitors , Pancreatic Neoplasms/drug therapy , Administration, Intravenous , Animals , Carcinoma, Pancreatic Ductal/enzymology , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival , Gene Expression Regulation, Neoplastic/drug effects , Humans , Immunoconjugates/pharmacology , Lung Neoplasms/enzymology , Mice , Pancreatic Neoplasms/enzymology , Up-Regulation/drug effects , Xenograft Model Antitumor Assays
7.
Heliyon ; 3(9): e00407, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28971150

ABSTRACT

BACKGROUND AND AIMS: Hepatocellular carcinoma (HCC) is a difficult to treat tumor with a poor prognosis. Aspartate ß-hydroxylase (ASPH) is a highly conserved enzyme overexpressed on the cell surface of both murine and human HCC cells. METHODS: We evaluated therapeutic effects of nanoparticle lambda (λ) phage vaccine constructs against ASPH expressing murine liver tumors. Mice were immunized before and after subcutaneous implantation of a syngeneic BNL HCC cell line. Antitumor actively was assessed by generation of antigen specific cellular immune responses and the identification of tumor infiltrating lymphocytes. RESULTS: Prophylactic and therapeutic immunization significantly delayed HCC growth and progression. ASPH-antigen specific CD4+ and CD8+ lymphocytes were identified in the spleen of tumor bearing mice and cytotoxicity was directed against ASPH expressing BNL HCC cells. Furthermore, vaccination generated antigen specific Th1 and Th2 cytokine secretion by immune cells. There was widespread necrosis with infiltration of CD3+ and CD8+ T cells in HCC tumors of λ phage vaccinated mice compared to controls. Moreover, further confirmation of anti-tumor effects on ASPH expressing tumor cell growth were obtained in another murine syngeneic vaccine model with pulmonary metastases. CONCLUSIONS: These observations suggest that ASPH may serve as a highly antigenic target for immunotherapy.

8.
Cancer Biother Radiopharm ; 32(2): 57-65, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28301261

ABSTRACT

There is a need for novel effective and safe therapies for metastatic breast cancer based on targeting tumor-specific molecular markers of cancer. Human aspartyl (asparaginyl) ß-hydroxylase (HAAH) is a highly conserved enzyme that hydroxylates epidermal growth factor-like domains in transformation-associated proteins and is overexpressed in a variety of cancers, including breast cancer. A fully human monoclonal antibody (mAb) PAN-622 has been developed to HAAH. In this study, they describe the development of PAN-622 mAb as an agent for imaging and radioimmunotherapy of metastatic breast cancer. PAN-622 was conjugated to several ligands such as DOTA, CHXA″, and DTPA to enable subsequent radiolabeling and its immunoreactivity was evaluated by an HAAH-specific enzyme-linked immunosorbent assay and binding to the HAAH-positive cells. As a result, DTPA-PAN-622 was chosen to investigate biodistribution in healthy CD-1 female mice and 4T1 mammary tumor-bearing BALB/c mice. The 111In-DTPA-pan622 mAb concentrated in the primary tumors and to some degree in lung metastases as shown by SPECT/CT and Cherenkov imaging. A pilot therapy study with 213Bi-DTPA-PAN-622 demonstrated a significant effect on the primary tumor. The authors concluded that human mAb PAN-622 to HAAH is a promising reagent for development of imaging and possible therapeutic agents for the treatment of metastatic breast cancer.


Subject(s)
Antibodies, Monoclonal/chemistry , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/drug therapy , Mixed Function Oxygenases/chemistry , Animals , Breast Neoplasms/radiotherapy , Cell Line, Tumor , Diagnostic Imaging/methods , Enzyme-Linked Immunosorbent Assay , Female , Humans , Ligands , Mice , Mice, Inbred BALB C , Neoplasm Metastasis , Radioimmunotherapy/methods , Tissue Distribution
9.
J Cell Sci ; 129(8): 1671-84, 2016 Apr 15.
Article in English | MEDLINE | ID: mdl-26945058

ABSTRACT

Collagen VI myopathies are genetic disorders caused by mutations in collagen 6 A1, A2 and A3 genes, ranging from the severe Ullrich congenital muscular dystrophy to the milder Bethlem myopathy, which is recapitulated by collagen-VI-null (Col6a1(-/-)) mice. Abnormalities in mitochondria and autophagic pathway have been proposed as pathogenic causes of collagen VI myopathies, but the link between collagen VI defects and these metabolic circuits remains unknown. To unravel the expression profiling perturbation in muscles with collagen VI myopathies, we performed a deep RNA profiling in both Col6a1(-/-)mice and patients with collagen VI pathology. The interactome map identified common pathways suggesting a previously undetected connection between circadian genes and collagen VI pathology. Intriguingly, Bmal1(-/-)(also known as Arntl) mice, a well-characterized model displaying arrhythmic circadian rhythms, showed profound deregulation of the collagen VI pathway and of autophagy-related genes. The involvement of circadian rhythms in collagen VI myopathies is new and links autophagy and mitochondrial abnormalities. It also opens new avenues for therapies of hereditary myopathies to modulate the molecular clock or potential gene-environment interactions that might modify muscle damage pathogenesis.


Subject(s)
ARNTL Transcription Factors/genetics , Circadian Clocks/physiology , Collagen Type VI/genetics , Contracture/genetics , Mitochondria/physiology , Muscular Dystrophies/congenital , Mutation/genetics , Sclerosis/genetics , Animals , Autophagy/genetics , Gene Expression Profiling , Humans , Mice , Mice, Knockout , Microarray Analysis , Muscular Dystrophies/genetics , RNA/analysis
10.
J Expo Sci Environ Epidemiol ; 21(2): 197-211, 2011.
Article in English | MEDLINE | ID: mdl-20197794

ABSTRACT

Cost-effective approaches for identifying and enrolling subjects in community-based epidemiological studies face many challenges. Additional challenges arise when a neighborhood scale of analysis is required to distinguish between individual- and group-level risk factors with strong environmental determinants. A stratified, two-stage, cross-sectional, address-based telephone survey of Greater Tucson, Arizona, was conducted in 2002-2003. Subjects were recruited from direct marketing data at neighborhood resolution using a geographic information system (GIS). Three geomorphic strata were divided into two demographic units. Households were randomly selected within census block groups, selected using the probability proportional to size technique. Purchased direct marketing lists represented 45.2% of Census 2000 households in the surveyed block groups. Survey design effect (1.6) on coccidioidomycosis prevalence (88 per 100,000 per year) was substantially reduced in four of the six strata (0.3-0.9). Race-ethnicity was more robust than age and gender to compensate for significant selection bias using poststratification. Clustered, address-based telephone surveys provide a cost-effective, valid method for recruiting populations from address-based lists using a GIS to design surveys and population survey statistical methods for analysis. Landscape ecology provides effective methods for identifying scales of analysis and units for stratification that will improve sampling efficiency when environmental variables of interest are strong predictors.


Subject(s)
Coccidioidomycosis/epidemiology , Environmental Exposure/analysis , Geographic Information Systems , Arizona/epidemiology , Coccidioidomycosis/diagnosis , Coccidioidomycosis/ethnology , Coccidioidomycosis/transmission , Cross-Sectional Studies , Demography , Epidemiologic Studies , Female , Humans , Male , Risk Factors , Telephone
11.
J Aging Phys Act ; 18(3): 313-34, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20651417

ABSTRACT

Little is known about how many years of life and disability-free years seniors can gain through exercise. Using data from the Cardiovascular Health Study, the authors estimated the extra years of life and self-reported healthy life (over 11 years) and years without impairment in activities of daily living (over 6 years) associated with quintiles of physical activity (PA) in older adults from different age groups. They estimated PA from the Minnesota Leisure Time Activities Questionnaire. Multivariable linear regression adjusted for health-related covariates. The relative gains in survival and years of healthy life (YHL) generally were proportionate to the amount of PA, greater among those 75+, and higher in men. Compared with being sedentary, the most active men 75+ had 1.49 more YHL (95% CI: 0.79, 2.19), and the most active women 75+ had 1.06 more YHL (95% CI: 0.44, 1.68). Seniors over age 74 experience the largest relative gains in survival and healthy life from physical activity.


Subject(s)
Cardiovascular Diseases/epidemiology , Exercise , Health Behavior , Health Status , Life Style , Activities of Daily Living , Age Factors , Aged , Aged, 80 and over , Cardiovascular Diseases/physiopathology , Cardiovascular Diseases/psychology , Cohort Studies , Female , Humans , Leisure Activities , Male , Quality-Adjusted Life Years , Sex Factors
12.
Am J Respir Crit Care Med ; 182(6): 819-25, 2010 Sep 15.
Article in English | MEDLINE | ID: mdl-20508218

ABSTRACT

RATIONALE: Sleep-disordered breathing (SDB), the recurrent episodic disruption of normal breathing during sleep, affects as much as 17% of U.S. adults, and may be more prevalent in poor urban environments. SDB and air pollution have been linked to increased cardiovascular diseases and mortality, but the association between pollution and SDB is poorly understood. OBJECTIVES: We used data from the Sleep Heart Health Study (SHHS), a U.S. multicenter cohort study assessing cardiovascular and other consequences of SDB, to examine whether particulate air matter less than 10 µm in aerodynamic diameter (PM(10)) was associated with SDB among persons 39 years of age and older. METHODS: Using baseline data from SHHS urban sites, outcomes included the following: the respiratory disturbance index (RDI); percentage of sleep time at less than 90% O(2) saturation; and sleep efficiency, measured by overnight in-home polysomnography. We applied a fixed-effect model containing a city effect, controlling for potential predictors. In all models we included both the 365-day moving averages of PM(10) and temperature (long-term effects) and the differences between the daily measures of these two predictors and their 365-day average (short-term effects). MEASUREMENTS AND MAIN RESULTS: In summer, increases in RDI or percentage of sleep time at less than 90% O(2) saturation, and decreases in sleep efficiency, were all associated with increases in short-term variation in PM(10). Over all seasons, we found that increased RDI was associated with an 11.5% (95% confidence interval: 1.96, 22.01) increase per interquartile range increase (25.5°F) in temperature. CONCLUSIONS: Reduction in air pollution exposure may decrease the severity of SDB and nocturnal hypoxemia and may improve cardiac risk.


Subject(s)
Air Pollutants/toxicity , Air Pollution/adverse effects , Particulate Matter/toxicity , Sleep Apnea Syndromes/etiology , Sleep/physiology , Urban Health , Adult , Aged , Aged, 80 and over , Cities , Cohort Studies , Female , Humans , Male , Middle Aged , Multicenter Studies as Topic , Particle Size , Polysomnography , Seasons , Severity of Illness Index , Sleep Apnea Syndromes/epidemiology , Temperature , United States/epidemiology
13.
Am J Respir Crit Care Med ; 182(2): 269-77, 2010 Jul 15.
Article in English | MEDLINE | ID: mdl-20339144

ABSTRACT

RATIONALE: Although obstructive sleep apnea is associated with physiological perturbations that increase risk of hypertension and are proatherogenic, it is uncertain whether sleep apnea is associated with increased stroke risk in the general population. OBJECTIVES: To quantify the incidence of ischemic stroke with sleep apnea in a community-based sample of men and women across a wide range of sleep apnea. METHODS: Baseline polysomnography was performed between 1995 and 1998 in a longitudinal cohort study. The primary exposure was the obstructive apnea-hypopnea index (OAHI) and outcome was incident ischemic stroke. MEASUREMENTS AND MAIN RESULTS: A total of 5,422 participants without a history of stroke at the baseline examination and untreated for sleep apnea were followed for a median of 8.7 years. One hundred ninety-three ischemic strokes were observed. In covariate-adjusted Cox proportional hazard models, a significant positive association between ischemic stroke and OAHI was observed in men (P value for linear trend: P = 0.016). Men in the highest OAHI quartile (>19) had an adjusted hazard ratio of 2.86 (95% confidence interval, 1.1-7.4). In the mild to moderate range (OAHI, 5-25), each one-unit increase in OAHI in men was estimated to increase stroke risk by 6% (95% confidence interval, 2-10%). In women, stroke was not significantly associated with OAHI quartiles, but increased risk was observed at an OAHI greater than 25. CONCLUSIONS: The strong adjusted association between ischemic stroke and OAHI in community-dwelling men with mild to moderate sleep apnea suggests that this is an appropriate target for future stroke prevention trials.


Subject(s)
Sleep Apnea, Obstructive/epidemiology , Stroke/epidemiology , Aged , Female , Humans , Longitudinal Studies , Male , Middle Aged , Polysomnography , Proportional Hazards Models , Prospective Studies , Severity of Illness Index , Sex Factors
14.
J Alzheimers Dis ; 17(3): 611-9, 2009.
Article in English | MEDLINE | ID: mdl-19433896

ABSTRACT

Oxidative stress plays a significant role in neurotoxicity associated with a variety of neurodegenerative diseases including Alzheimer's disease (AD). Increased oxidative stress has been shown to be a prominent and early feature of vulnerable neurons in AD. Olfactory neuroepithelial cells are affected at an early stage. Exposure to oxidative stress induces the accumulation of intracellular reactive oxygen species (ROS), which in turn causes cell damage in the form of protein, lipid, and DNA oxidations. Elevated ROS levels are also associated with increased deposition of amyloid-beta and formation of senile plaques, a hallmark of the AD brain. If enhanced ROS exceeds the basal level of cellular protective mechanisms, oxidative damage and cell death will result. Therefore, substances that can reduce oxidative stress are sought as potential drug candidates for treatment or preventative therapy of neurodegenerative diseases such as AD. PAN-811, also known as 3-aminopyridine-2-carboxaldehyde thiosemicarbazone or Triapine, is a small lipophilic compound that is currently being investigated in several Phase II clinical trials for cancer therapy due to its inhibition of ribonucleotide reductase activity. Here we show PAN-811 to be effective in preventing or reducing ROS accumulation and the resulting oxidative damages in both AD-derived and age-matched olfactory neuroepithelial cells.


Subject(s)
Alzheimer Disease/pathology , Neuroepithelial Cells/drug effects , Neuroprotective Agents/pharmacology , Olfactory Pathways/pathology , Oxidative Stress/drug effects , Pyridines/pharmacology , Reactive Oxygen Species/metabolism , Thiosemicarbazones/pharmacology , Aged , Aging/pathology , Analysis of Variance , Case-Control Studies , Cell Death/drug effects , Dose-Response Relationship, Drug , Extracellular Fluid/drug effects , Extracellular Fluid/metabolism , Humans , Hydrogen Peroxide/pharmacology , L-Lactate Dehydrogenase/metabolism , Oxidants/pharmacology
15.
Newsweek ; 149(20): 71, 2007 May 14.
Article in English | MEDLINE | ID: mdl-19130843
16.
CNS Drug Rev ; 12(1): 77-90, 2006.
Article in English | MEDLINE | ID: mdl-16834759

ABSTRACT

3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP) is a highly-hydrophobic small molecule that was originally developed for cancer therapy (Triapine, Vion Pharmaceuticals) due to its ability to inhibit ribonucleotide reductase, a key enzyme required for DNA synthesis. 3-AP has a high affinity for divalent cations, chelating the Fe(2+) at the R2 subunit of the enzyme and inhibiting formation of a tyrosyl radical essential for ribonucleotide reduction. We have demonstrated that 3-AP is also a potent neuroprotectant (as such, it is referred to as "PAN-811"). In vitro it completely blocks ischemic neurotoxicity at a concentration of 0.5 microM (EC(50) approximate, equals 0.35 microM) and hypoxic toxicity at 1.2 microM (EC(50) approximate, equals 0.75 microM). Full protection of primary cortical and striatal neurons can be achieved with 3-AP when it is added to the medium at up to six hours after an ischemic insult. 3-AP also suppresses cell death induced by neurotoxic agents, including staurosporine, veratridine and glutamate, indicating activity against a central target(s) in the neurodegenerative process. 3-AP acts via neutralization of two important intracellular effectors of excitatory neurotoxicity; calcium and free radicals. Its reported ability to elevate anti-apoptotic proteins is likely to be a consequence of the suppression of excessive intracellular free calcium. In a rat model of transient ischemia, a single bolus delivery of 3-AP 1 h after the initiation of ischemic attack reduced infarct volume by 59% when administered i.c.v. (50 mug per rat) and by 35% when administered i.v. (1 mg/kg). In Phase I clinical trials in cancer therapy 3-AP had no cardiovascular, CNS or other major adverse effects. Thus, 3-AP has a high potential for development as a novel, potent neuroprotectant for the treatment of neurodegenerative diseases.


Subject(s)
Analgesics/therapeutic use , Brain Diseases/prevention & control , Neoplasms/drug therapy , Neuroprotective Agents/therapeutic use , Pyridines/therapeutic use , Thiosemicarbazones/therapeutic use , Analgesics/chemistry , Analgesics/pharmacology , Animals , Brain Diseases/etiology , Brain Diseases/pathology , Cell Death/drug effects , Humans , Neurons/drug effects , Neuroprotective Agents/chemistry , Pyridines/chemistry , Pyridines/pharmacology , Thiosemicarbazones/chemistry , Thiosemicarbazones/pharmacology
17.
Proc Natl Acad Sci U S A ; 103(5): 1581-6, 2006 Jan 31.
Article in English | MEDLINE | ID: mdl-16423893

ABSTRACT

Cellular and molecular pathways underlying ischemic neurotoxicity are multifaceted and complex. Although many potentially neuroprotective agents have been investigated, the simplicity of their protective mechanisms has often resulted in insufficient clinical utility. We describe a previously uncharacterized class of potent neuroprotective compounds, represented by PAN-811, that effectively block both ischemic and hypoxic neurotoxicity. PAN-811 disrupts neurotoxic pathways by at least two modes of action. It causes a reduction of intracellular-free calcium as well as free radical scavenging resulting in a significant decrease in necrotic and apoptotic cell death. In a rat model of ischemic stroke, administration of PAN-811 i.c.v. 1 h after middle cerebral artery occlusion resulted in a 59% reduction in the volume of infarction. Human trials of PAN-811 for an unrelated indication have established a favorable safety and pharmacodynamic profile within the dose range required for neuroprotection warranting its clinical trial as a neuroprotective drug.


Subject(s)
Infarction, Middle Cerebral Artery/drug therapy , Ischemia , Neurodegenerative Diseases/drug therapy , Neuroprotective Agents/pharmacology , Pyridines/pharmacology , Thiosemicarbazones/pharmacology , Animals , Apoptosis , Blotting, Western , Calcium/metabolism , Cerebral Cortex/metabolism , Chelating Agents/pharmacology , Coculture Techniques , Corpus Striatum/metabolism , DNA Fragmentation , Disease Models, Animal , Dose-Response Relationship, Drug , Fluoresceins/pharmacology , Free Radical Scavengers/metabolism , Humans , Hypoxia , L-Lactate Dehydrogenase/metabolism , Male , Necrosis , Neurons/metabolism , Rats , Rats, Sprague-Dawley , Reactive Oxygen Species , Time Factors
20.
Prev Chronic Dis ; 2(1): A19, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15670472

ABSTRACT

BACKGROUND: The increase in childhood obesity and prevalence of chronic disease risk factors demonstrate the importance of creating healthy school environments. As part of the Border Health Strategic Initiative, the School Health Index was implemented in public schools in two counties along the Arizona, United States-Sonora, Mexico border. Developed in 2000 by the Centers for Disease Control and Prevention, the School Health Index offers a guide to assist schools in evaluating and improving opportunities for physical activity and good nutrition for their students. CONTEXT: Between 2000 and 2003, a total of 13 schools from five school districts in two counties participated in the School Health Index project despite academic pressures and limited resources. METHODS: The Border Health Strategic Initiative supported the hiring and training of an external coordinator in each county who was not part of the school system but who was an employee in an established community-based organization. The coordinators worked with the schools to implement the School Health Index, to develop action plans, and to monitor progress toward these goals. CONSEQUENCES: The School Health Index process and school team participation varied from school to school. Individual plans were different but all focused on reducing in-school access to unhealthy foods, identified as high-fat and/or of low nutritional value. Ideas for acting on this focus ranged from changing the content of school lunches to discontinuing the use of nonnutritious foods as classroom rewards. All plans included recommendations that could be implemented immediately as well as those that would require planning and perhaps the formation and assistance of a subcommittee (e.g., for developing or adopting a district-wide health curriculum). INTERPRETATION: After working with the School Health Index, most schools made at least one immediate change in their school environments. The external coordinator was essential to keeping the School Health Index results and action plans on the agendas of school administrators, especially during periods of staff turnover. Staff turnover, lack of time, and limited resources resulted in few schools achieving longer-term policy changes.


Subject(s)
Health Status Indicators , Arizona , Child , Humans , International Cooperation , Mexico , Schools
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