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Biomedical subjects

Yang Xie

Publications and source records attributed to Yang Xie.

18 recordsLinked to original sources

Genetic haplotypes in VWA8, OSBPL6, and ADAMTS9-AS2 are associated with immune-related adverse effects in ICI-treated patients with cancer.

BACKGROUND: Immune-related adverse events (irAEs) remain largely unpredictable, potentially affecting multiple organ systems and occurring at almost any point during and even occasionally after immune checkpoint inhibitor (ICI) treatment. To identify populations at risk for these immune-mediated toxicities, we analyzed genetic characteristics and immune markers associated with clinically significant irAEs. METHODS: We carried out a genome-wide association study on 373 white patients receiving ICI treatment. We identified single nucleotide polymorphisms associated with irAEs. Blood cytokine profiling and peripheral blood mononuclear cell RNA sequencing were performed at pretreatment baseline and 6-8 weeks after ICI initiation. Findings were validated in two external cohorts. RESULTS: We identified genetic haplotypes in VWA8 (Von Willebrand Factor A Domain Containing 8), OSBPL6 (Oxysterol Binding Protein Like 6), and ADAMTS9-AS2 (ADAM Metallopeptidase With Thrombospondin Type 1 Motif 9 Antisense RNA 2) associated with grade &#x2265;2 irAEs. Patients carrying risk haplotypes for one or more genes exhibited significantly greater rates of grade &#x2265;2 (OR 3.02; 95%&#x2009;CI 1.83 to 5.02; p<0.001), grade &#x2265;3 (OR 3.59; 95%&#x2009;CI 1.93 to 6.64; p<0.001), and multiple type irAE (OR 2.60; 95%&#x2009;CI 1.53 to 4.39; p<0.001). Serum CCL3 levels were significantly elevated in individuals carrying risk haplotypes (p=0.03). Gene expression analysis demonstrated activated autoimmune and inflammatory pathways in the genetic risk group. CONCLUSIONS: Novel polymorphisms in VWA8, OSBPL6, and ADAMTS9-AS2 may impact immune pathways, promote inflammation, potentiate autoimmune phenotypes, and convey risk of irAE in ICI-treated patients.

Humans↗

Incorporating prior information via shrinkage: a combined analysis of genome-wide location data and gene expression data.

Transcriptional control is a critical step in regulation of gene expression. Understanding such a control on a genomic level involves deciphering the mechanisms and structures of regulatory programmes and networks. A difficulty arises due to the weak signal and high noise in various sources of data while most current approaches are limited to analysis of a single source of data. A natural alternative is to improve statistical efficiency and power by a combined analysis of multiple sources of data. Here we propose a shrinkage method to combine genome-wide location data and gene expression data to detect the binding sites or target genes of a transcription factor. Specifically, a prior 'non-target' gene list is generated by analysing the expression data, and then this information is incorporated into the subsequent binding data analysis via a shrinkage method. There is a Bayesian justification for this shrinkage method. Both simulated and real data were used to evaluate the proposed method and compare it with analysing binding data alone. In simulation studies, the proposed method gives higher sensitivity and lower false discovery rate (FDR) in detecting the target genes. In real data example, the proposed method can reduce the estimated FDR and increase the power to detect the previously known target genes of a broad transcription regulator, leucine responsive regulatory protein (Lrp) in Escherichia coli. This method can also be used to incorporate other information, such as gene ontology (GO), to microarray data analysis to detect differentially expressed genes.

Bayes Theorem↗

Production of a novel recombinant Drosophila melanogaster acetylcholinesterase for detection of organophosphate and carbamate insecticide residues.

A novel recombinant Drosophila melanogaster acetylcholinesterase (R-DmAChE) produced in Pichia pastoris was first reported in this study. We cloned the DmAChE cDNA by reverse transcription PCR with removal of the signal for glycosylphosphatidylinositol (GPI) anchor attachment and the endogenous signal peptide coding sequence, and inserted it into P. pastoris vector pPIC9K under control of the alcohol oxidase gene AOX1 promoter (5'AOX1). The expression cassette of AChE cDNA was then introduced into methylotrophic yeast GS115 and several recombinant strains expressing R-DmAChE were obtained. The secreted R-DmAChE showed high stability in neutral phosphate buffer at 4 degrees C, and its kinetic parameters were identical to those of the native DmAChE. The bimolecular rate constants of R-DmAChE to dichlorvos, aldicarb and carbaryl were ranging from three to six times higher than of native DmAChE. Within six insecticides, the R-DmAChE was more sensitive than EeAChE, NbAChE and HuAChE. For 10 widely used insecticides, the IC50 values to the R-DmAChE were much lower than those to AChEs commonly used in China. With the R-DmAChE-based assay, samples spiked with three concentrations of pesticides caused enzymatic activity inhibition with R.S.D. of 0-13.7%. These results suggest that the R-DmAChE can be useful for detection of organophosphate and carbamate insecticide residues.

Acetylcholinesterase↗

Dynamics of paramagnetic agents by off-resonance rotating frame technique in the presence of magnetization transfer effect.

The simple method for measuring the rotational correlation time of paramagnetic ion chelates via off-resonance rotating frame technique is challenged in vivo by the magnetization transfer effect. A theoretical model for the spin relaxation of water protons in the presence of paramagnetic ion chelates and magnetization transfer effect is described. This model considers the competitive relaxations of water protons by the paramagnetic relaxation pathway and the magnetization transfer pathway. The influence of magnetization transfer on the total residual z-magnetization has been quantitatively evaluated in the context of the magnetization map and various difference magnetization profiles for the macromolecule conjugated Gd-DTPA in cross-linked protein gels. The numerical simulations and experimental validations confirm that the rotational correlation time for the paramagnetic ion chelates can be measured even in the presence of strong magnetization transfer. This spin relaxation model also provides novel approaches to enhance the detection sensitivity for paramagnetic labeling by suppressing the spin relaxations caused by the magnetization transfer. The inclusion of the magnetization transfer effect allows us to use the magnetization map as a simulation tool to design efficient paramagnetic labeling targeting at specific tissues, to design experiments running at low RF power depositions, and to optimize the sensitivity for detecting paramagnetic labeling. Thus, the presented method will be a very useful tool for the in vivo applications such as molecular imaging via paramagnetic labeling.

Algorithms↗

Dynamics of paramagnetic agents by off-resonance rotating frame technique.

Off-resonance rotating frame technique offers a novel tool to explore the dynamics of paramagnetic agents at high magnetic fields (B0 > 3T). Based on the effect of paramagnetic relaxation enhancement in the off-resonance rotating frame, a new method is described here for determining the dynamics of paramagnetic ion chelates from the residual z-magnetizations of water protons. In this method, the dynamics of the chelates are identified by the difference magnetization profiles, which are the subtraction of the residual z-magnetization as a function of frequency offset obtained at two sets of RF amplitude omega(1) and pulse duration tau. The choices of omega(1) and tau are guided by a 2-D magnetization map that is created numerically by plotting the residual z-magnetization as a function of effective field angle theta and off-resonance pulse duration tau. From the region of magnetization map that is the most sensitive to the alteration of the paramagnetic relaxation enhancement efficiency R(1rho)/R1, the ratio of the off-resonance rotating frame relaxation rate constant R(1rho) verse the laboratory frame relaxation rate constant R(1), three types of difference magnetization profiles can be generated. The magnetization map and the difference magnetization profiles are correlated with the rotational correlation time tauR of Gd-DTPA through numerical simulations, and further validated by the experimental data for a series of macromolecule conjugated Gd-DTPA in aqueous solutions. Effects of hydration water number q, diffusion coefficient D, magnetic field strength B0 and multiple rotational correlation times are explored with the simulations of the magnetization map. This method not only provides a simple and reliable approach to determine the dynamics of paramagnetic labeling of molecular/cellular events at high magnetic fields, but also a new strategy for spectral editing in NMR/MRI based on the dynamics of paramagnetic labeling in vivo.

Algorithms↗

Analysis of pleiotropic transcriptional profiles: a case study of DNA gyrase inhibition.

Genetic and environmental perturbations often result in complex transcriptional responses involving multiple genes and regulons. In order to understand the nature of a response, one has to account for the contribution of the downstream effects to the formation of a response. Such analysis can be carried out within a statistical framework in which the individual effects are independently collected and then combined within a linear model. Here, we modeled the contribution of DNA replication, supercoiling, and repair to the transcriptional response of inhibition of the Escherichia coli gyrase. By representing the gyrase inhibition as a true pleiotropic phenomenon, we were able to demonstrate that: (1) DNA replication is required for the formation of spatial transcriptional domains; (2) the transcriptional response to the gyrase inhibition is coordinated between at least two modules involved in DNA maintenance, relaxation and damage response; (3) the genes whose transcriptional response to the gyrase inhibition does not depend on the main relaxation activity of the cell can be classified on the basis of a GC excess in their upstream and coding sequences; and (4) relaxation by topoisomerase I dominates the transcriptional response, followed by the effects of replication and RecA. We functionally tested the effect of the interaction between relaxation and repair activities, and found support for the model derived from the microarray data. We conclude that modeling compound transcriptional profiles as a combination of downstream transcriptional effects allows for a more realistic, accurate, and meaningful representation of the transcriptional activity of a genome.

DNA Gyrase↗

Efficiency of paramagnetic relaxation enhancement in off-resonance rotating frame.

Transferring from laboratory frame to off-resonance rotating frame for the (1)H spin can compensate the relaxivity loss for paramagnetic agents at the magnetic field strength higher than 3 Tesla and enhance water relaxation rate constant significantly. A comprehensive theory for calculating the relaxation rate constants in the off-resonance rotating frame is described. This theory considers the contributions from both inner shell and outer shell water. The derived relaxation rate constants and relaxation enhancement efficiency as a function of the magnetic field strength and the effective field parameters are directly correlated to the structures, dynamics and environments of paramagnetic agents. To validate the theoretical predictions, we have measured the relaxation enhancement efficiency for a series of macromolecule conjugated gadolinium chelates at 9.4 Tesla. The experimental results confirmed the theoretical predictions. The theory also predicts the relaxation enhancement for T(2)-type paramagnetic agents at high magnetic fields. Promising fields of applications include situations where T(1)- or T(2)-type paramagnetic agents are used for labeling molecular/cellular events.

Animals↗

Managed care, consumerism, preventive medicine: does a causal connection exist?

Managed care plans, and HMOs in particular, have long touted that their emphasis is on preventive care, to avoid expensive illness later in life. However, few articles in the contemporary literature adequately address this claim. The available evidence seems to support that HMOs do, in fact, provide greater access to preventive services, but the limitations of this research are substantial. This article discusses the scientific evidence on the relationships between managed care arrangements and the implications for preventive care in the current era, emphasizing consumer choices and less-restrictive plan structures.

Community Participation↗

A note on using permutation-based false discovery rate estimates to compare different analysis methods for microarray data.

MOTIVATION: False discovery rate (FDR) is defined as the expected percentage of false positives among all the claimed positives. In practice, with the true FDR unknown, an estimated FDR can serve as a criterion to evaluate the performance of various statistical methods under the condition that the estimated FDR approximates the true FDR well, or at least, it does not improperly favor or disfavor any particular method. Permutation methods have become popular to estimate FDR in genomic studies. The purpose of this paper is 2-fold. First, we investigate theoretically and empirically whether the standard permutation-based FDR estimator is biased, and if so, whether the bias inappropriately favors or disfavors any method. Second, we propose a simple modification of the standard permutation to yield a better FDR estimator, which can in turn serve as a more fair criterion to evaluate various statistical methods. RESULTS: Both simulated and real data examples are used for illustration and comparison. Three commonly used test statistics, the sample mean, SAM statistic and Student's t-statistic, are considered. The results show that the standard permutation method overestimates FDR. The overestimation is the most severe for the sample mean statistic while the least for the t-statistic with the SAM-statistic lying between the two extremes, suggesting that one has to be cautious when using the standard permutation-based FDR estimates to evaluate various statistical methods. In addition, our proposed FDR estimation method is simple and outperforms the standard method.

Algorithms↗

Genome-wide localization of mobile elements: experimental, statistical and biological considerations.

BACKGROUND: The distribution and location of insertion elements in a genome is an excellent tool to track the evolution of bacterial strains and a useful molecular marker to distinguish between closely related bacterial isolates. The information about the genomic locations of IS elements is available in public sequence databases. However, the locations of mobile elements may vary from strain to strain and within the population of an individual strain. Tools that allow de novo localization of IS elements and are independent of existing sequence information are essential to map insertion elements and advance our knowledge of the role that such elements play in gene regulation and genome plasticity in bacteria. RESULTS: In this study, we present an efficient and reliable method for linear mapping of mobile elements using whole-genome DNA microarrays. In addition, we describe an algorithm for analysis of microarray data that can be applied to find DNA sequences physically juxtaposed with a target sequence of interest. This approach was used to map the locations of the IS5 elements in the genome of Escherichia coli K12. All IS5 elements present in the E. coli genome known from GenBank sequence data were identified. Furthermore, previously unknown insertion sites were predicted with high sensitivity and specificity. Two variants of E. coli K-12 MG1655 within a population of this strain were predicted by our analysis. The only significant difference between these two isolates was the presence of an IS5 element upstream of the main flagella regulator, flhDC. Additional experiments confirmed this prediction and showed that these isolates were phenotypically distinct. The effect of IS5 on the transcriptional activity of motility and chemotaxis genes in the genome of E. coli strain MG1655 was examined. Comparative analysis of expression profiles revealed that the presence of IS5 results in a mild enhancement of transcription of the flagellar genes that translates into a slight increase in motility. CONCLUSION: In summary, this work presents a case study of an experimental and analytical application of DNA microarrays to map insertion elements in bacteria and gains an insight into biological processes that might otherwise be overlooked by relying solely on the available genome sequence data.

DNA Transposable Elements↗

Chemopreventive activity of selenocysteine prodrugs against tobacco-derived nitrosamine (NNK) induced lung tumors in the A/J mouse.

Prodrugs of L-selenocysteine have potential utility in cancer chemoprevention. This study reports the efficacy of three selenazolidine-4(R)-carboxylic acids, (2-unsubstituted, 2-oxo, and 2-methyl derivatives; SCA, OSCA, and MSCA, respectively) against tobacco-related lung tumorigenesis in a mouse model. Seven days after initiation of an AIN-76A diet supplemented with sodium selenite (5 ppm Se), L-selenomethionine (3.75 ppm Se), Se-methyl-L-selenocysteine (3 ppm Se), L-selenocystine (15 ppm Se), SCA (15 ppm Se), OSCA (15 ppm Se), or MSCA (15 ppm Se), mice received 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK; 10 micromol, i.p.). After an additional 16 weeks on the diets, two compounds, OSCA and selenocystine, significantly reduced lung adenoma multiplicity from 7.2 tumors per mouse in the NNK group to 4.5 and 4.6 tumors per mouse, respectively. Neither selenium concentration nor glutathione peroxidase activity in either RBCs or liver served as surrogate indicators of tumor reduction. Hepatic selenium levels were significantly elevated by all selenium-containing compounds except Se-methyl-L-selenocysteine and SCA; RBC selenium levels by all except sodium selenite and MSCA. With the exception of L-selenomethionine, RBC glutathione peroxidase activity was increased along with the elevated selenium levels. Hepatic glutathione peroxidase activity was elevated by all Se-compounds except SCA. The two compounds showing significant tumor reduction (OSCA and selenocystine) were the only two compounds that showed ubiquity of changes, elevating both selenium levels and GPx activity in both liver and RBC.

Animals↗

Maternal diet and infant leukemia: the DNA topoisomerase II inhibitor hypothesis: a report from the children's oncology group.

BACKGROUND: The MLL 11q23 translocation arises in utero and is present in 75% of infant leukemias. That MLL+ acute myeloid leukemia (AML) can arise following chemotherapy with DNA topoisomerase II (DNAt2) inhibitors suggests that these substances, which also occur naturally in foods, may contribute toward infant leukemia. We hypothesized that maternal consumption of dietary DNAt2 inhibitors during pregnancy would increase the risk of infant leukemia, particularly AML(MLL+). METHODS: This Children's Oncology Group case-control study consisted of 240 incident cases of infant acute leukemia [AML and acute lymphoblastic leukemia (ALL)] diagnosed during 1996 to 2002 and 255 random digit dialed controls. Maternal diet during pregnancy was determined through a food frequency questionnaire. An index of specific foods identified a priori to contain DNAt2 inhibitors as well as vegetables and fruits were created and analyzed using unconditional logistic regression. RESULTS: There was little evidence of an association between the specific DNAt2 index and leukemia overall and by subtype. An exception was AML(MLL+); odds ratios (95% confidence intervals) comparing the second to fourth quartiles to the first were 1.9 (0.5-7.0), 2.1 (0.6-7.7), and 3.2 (0.9-11.9), respectively (P for trend = 0.10). For the vegetable and fruit index, there were significant or near-significant inverse linear trends for all leukemias combined, ALL(MLL+), and AML(MLL-). CONCLUSION: Overall, maternal consumption of fresh vegetables and fruits during pregnancy was associated with a decreased risk of infant leukemia, particularly MLL+. However, for AML(MLL+) cases, maternal consumption of specific DNAt2 inhibitors seemed to increase risk. Although based on small numbers, these data provide some support for distinct etiologic pathways in infant leukemia.

Acute Disease↗

Characteristics of selenazolidine prodrugs of selenocysteine: toxicity, selenium levels, and glutathione peroxidase induction in A/J mice.

We have previously reported the synthesis and characterization of two new classes of selenazolidine-4(R)-carboxylic acids (2-oxo and 2-methyl-SCAs) (OSCA and MSCA, respectively), as well as the "parent" compound, selenazolidine-4(R)-carboxylic acid (SCA, selenaproline). These compounds were designed as prodrugs of L-selenocysteine with potential application in cancer chemoprevention or other clinical uses. We will be exploring the chemopreventive activity of the new compounds in the well-established A/J mouse model of tobacco-induced lung carcinogenesis. The objectives of the present study were to investigate several fundamental biochemical endpoints after selenazolidine administration compared with other selenium-containing agents. Groups of mice were fed either AIN-76A diet alone or the diet supplemented with the following selenium compounds (ppm Se): sodium selenite (5), L-selenomethionine (3.75), L-selenocystine (15), Se-methyl-L-selenocysteine (3), MSCA (5, 10, or 15), OSCA (5, 10, or 15), or SCA (5, 10, or 15). After 28 days of supplementation, toxicity of the selenazolidines was not evident, as measured by outward appearance and behavior, body and organ weight changes, and histological evaluation of liver and lung tissue. Select treatment groups showed significant increases in selenium levels in blood and tissues. Increased activity of selenium-dependent glutathione peroxidase (GPx) in blood and liver illustrated that the selenazolidines provided a source of biologically-available selenium.

Animals↗

Risperidone in combination with mood stabilizers: a 10-week continuation phase study in bipolar I disorder.

BACKGROUND: Combination therapy (risperidone and a mood stabilizer) for patients with a history of bipolar disorder (DSM-IV) and hospitalized for treatment of a manic episode was assessed in a 13-week study. METHOD: Subjects received flexible doses of a mood stabilizer (lithium or divalproex) plus placebo, risperidone, or haloperidol in a 3-week double-blind study. They could then enter a 10-week open-label study during which they received risperidone combined with a mood stabilizer. RESULTS: Of the 156 patients enrolled in the 3-week study, 85 entered the 10-week open-label extension, of whom 48 completed 10 weeks of treatment. The mean +/- SE doses of risperidone were 3.8 +/- 0.3 mg/day during the 3-week study and 3.1 +/- 0.2 mg/day during the 10-week study. At double-blind endpoint, mean reductions in Young Mania Rating Scale (YMRS) scores were significantly greater in patients receiving risperidone plus mood stabilizer than in those receiving placebo plus mood stabilizer (-14.3 vs. -8.2, p <.001). Further significant (p <.001) reductions were seen during the 10 weeks of treatment with risperidone plus mood stabilizer. Symptom remission (YMRS score <or= 12) was seen in 38 patients (79%) at the end of the 10-week study. Scores on the Brief Psychiatric Rating Scale, Hamilton Rating Scale for Depression, and Clinical Global Impressions scale improved significantly (p <.05) during both the 3-week and 10-week studies. Treatment was well tolerated, and modest weight gain was observed during the 13-week study period. CONCLUSION: The combination of risperidone and a mood stabilizer was efficacious and well tolerated in the continuation treatment of patients initially hospitalized for the management of an acute manic episode.

Adult↗

Characteristics of selenazolidine prodrugs of selenocysteine: toxicity and glutathione peroxidase induction in V79 cells.

Novel selenazolidine prodrugs of selenocysteine are being developed as potential selenium delivery agents for cancer chemoprevention and other clinical uses. The 2-unsubstituted compound, selenazolidine-4(R)-carboxylic acid (L-SCA), and the 2-oxo- and 2-methyl analogues possessing D-stereochemistry (D-OSCA and D-MSCA, respectively) were synthesized and chemically characterized. L/D pairs, along with other organoselenium compounds and common inorganic forms, were studied in cultured V79 cells to understand their inherent toxicity and their ability to induce selenium-dependent glutathione peroxidase (GPx) activity, which indicates the provision of biologically available selenium. All of the selenazolidines were much less toxic to the cells than was sodium selenite (IC(50) approximately 17 microM) or the parent selenolamines, L- or D-selenocystine (IC(50) approximately 34 or 39 microM, respectively); OSCA was less toxic than MSCA. The stereoisomers of OSCA produced very different IC(50) values (L-OSCA, approximately 451 microM; D-OSCA, >3000 microM), while the IC(50) values derived for the stereoisomers of MSCA were of the same order of magnitude (L-MSCA, approximately 79 microM; D-MSCA, approximately 160 microM). Compounds possessing L-stereochemistry were at least as active with respect to GPx induction as was sodium selenite (2.2-fold increase at 15 microM). L-Selenocystine produced a 4.2-fold increase in GPx activity at 30 microM, while L-SCA produced a 5.9-fold increase, followed by L-OSCA (4.6-fold) and L-MSCA (2.1-fold), all at 100 microM. Compounds possessing D-stereochemistry showed minimal ability to induce GPx activity (D-selenocystine, 1.0-fold increase; D-OSCA, 1.4-fold increase; D-MSCA, 1.3-fold increase).

Animals↗

Cancer in the Minnesota Hmong population.

BACKGROUND: The Hmong are an isolated, agrarian people who settled in the mountainous regions of what today are Vietnam, Cambodia, and Laos. After the Vietnam War, many Hmong were relocated to the U.S. Minnesota has the second largest population (after California) of Hmong individuals. The objective of this study was to examine cancer incidence in this population, because it may indicate areas for targeted surveillance and intervention. METHODS: The Minnesota Cancer Surveillance System database was screened for Hmong surnames, and proportional incidence ratios (PIRs) were calculated for the period 1988-1999. RESULTS: Compared with all Minnesotans, the Hmong population had increased PIRs for nasopharyngeal cancer (PIR, 39.39; 95% confidence interval [95% CI], 21.01-66.86), gastric cancer (PIR, 8.70; 95% CI, 5.39-13.25), hepatic cancer (PIR, 8.08; 95% CI, 3.88-14.71), and cervical cancer (PIR, 3.72; 95% CI, 2.04-6.20) and had decreased PIRs for prostate cancer, breast cancer, Hodgkin disease, and melanoma. CONCLUSIONS: The current observations have implications for cancer control interventions. In particular, an increased incidence of cervical cancer might be addressed in part by targeting culturally sensitive screening programs in the Hmong population.

Adolescent↗

Trends in leukemia incidence and survival in the United States (1973-1998).

BACKGROUND: It is estimated that each year, approximately 30,800 individuals will be diagnosed with leukemia in the United States and 21,700 individuals will die of the disease. Although the overall incidence of leukemia has been declining in the United States, recent reports suggest that incidence rates may be increasing for certain age and racial groups. METHODS: Leukemia incidence (including acute lymphoblastic leukemia [ALL], acute myeloid leukemia [AML], chronic myeloid leukemia [CML], and chronic lymphoblastic leukemia [CLL]) and 5-year survival rates were obtained from the Surveillance, Epidemiology, and End Results (SEER) program. Specific rates for age (birth-19, 20-44, 45-64, and 65 + years), gender, and race (black, white) were also examined. RESULTS: A total of 66,404 cases of leukemia were identified for the period 1973-1998 in the nine reporting SEER sites. For children younger than 20 years old, the overall incidence rate of leukemia increased significantly (estimated annual percent change [EAPC] = 0.5%, 95% confidence interval [CI] = 0.1-0.9), whereas the rate decreased significantly among the group 65 years and older (EAPC = - 0.3, 95% CI = - 0.5 to - 0.1). Incidence rates for CLL and CML decreased significantly during this time period, whereas incidence rates for AML remained stable. Children younger than 20 years old experienced a 15% increase in the 5-year survival rates for both ALL and AML when comparing the two 10-year periods of 1974-1983 and 1984-1993. In contrast, there was little overall improvement in survival for adults 45 years and older. In particular, there was a notable decrease in the overall 5-year survival for blacks older than 65 years and for black males older than 44 years. CONCLUSIONS: Although the current study confirmed some of the results noted in other populations, the observed overall decline in leukemia survival for blacks is surprising and warrants further investigation.

Adolescent↗

Prescription medication use during pregnancy and risk of infant leukemia (United States).

OBJECTIVE: We explored whether maternal medication use during pregnancy may be an important etiologic area for investigation in studies of infant leukemia. METHODS: In this case-control study, associations were explored between specific medications as recorded in the medical records of 243 mothers of infants who were diagnosed with leukemia at < 18 months of age and 393 mothers ol infants without leukemia identified through random digit dialing. Cases included 157 acute lymphoblastic (ALL), 77 acute myeloid (AML), and nine other leukemias. A total of 27 different drugs that were prescribed for at least six women were analyzed. RESULTS: Overall, non-statistically significant negative associations (Odds ratios, OR < 0.5) were observed with amoxicillin, nystatin, clomiphene, levothyroxine, cefaclor, and trimethobenzamide HCL. When cases were restricted to either myeloid or lymphoblastic leukemia, cotrimoxazole was prescribed for five ALL case mothers and no matched controls; no association with cotrimoxazole was observed with AML. CONCLUSIONS: Given the number of comparisons, chance cannot be ruled out for any of the associations found here. However, a strength of this study is the lack of recall bias. The disparate data observed between AML and ALL in some instances may indicate areas of interest; they will be explored further in a case-control study of infant leukemia that is currently underway.

Case-Control Studies↗