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Climate change would cause negative impacts on future agricultural production and food security. Adaptive measures should be taken to mitigate the adverse effects. The objectives of this study were to simulate the potential effects of climate change on maize yields in Heilongjiang Province and to evaluate two selected typical household-level autonomous adaptive measures (cultivar changes and planting time adjustments) for mitigating the risks of climate change based on the CERES-Maize model.The results showed that flowering duration and maturity duration of maize would be shortened in the future climate and thus maize yield would reduce by 11-46% during 2011-2099 relative to 1981-2010. Increased CO2 concentration would not benefit maize production significantly. However, substituting local cultivars with later-maturing ones and delaying the planting date could increase yields as the climate changes.The results provide insight regarding the likely impacts of climate change on maize yields and the efficacy of selected adaptive measures by presenting evidence-based implications and mitigation strategies for the potential negative impacts of future climate change.

The primary objective of this exploratory study was to evaluate the effect of a multivitamin multimineral with phytonutrient supplement on heart health risk factors. One hundred twenty healthy adults (40-70 y) were recruited in this 8-week randomized double blind placebo control study. B-carotene, a-tocopherol, vitamin C, red blood cell (RBC) folate, B6, B12, Zn, Se content in blood were measured on Day 1, 28 and 56 and quercetin was measured on Day 1 and 56. Heart health risk factors such as homocysteine (Hcy), high-sensitivity C-reactive protein (hs-CRP), oxidized LDL (ox-LDL), gamma-glutamyl transferase (GGT), uric acid and blood lipid profile were monitored on Day 1 and 56. Results showed that supplementation significantly improved quercetin (p=0.0047), vitamin C (p=0.0011), RBC folate (p=0.0027) and B6 (p=0.0012) status after 8 weeks of consumption. A greater decrease of Hcy (p=0.0314), GGT (p=0.0545) and uric acid (p=0.1683) was also observed. However, a lesser degree of increase of hs-CRP (p=0.2511...

Lung cancer including non-small cell lung cancer (NSCLC) and small cell lung cancer is one of the most aggressive tumors with high incidence and low survival rate. The typical NSCLC patients account for 80-85 % of the total lung cancer patients. To systemically explore the molecular mechanisms of NSCLC, we performed a molecular network analysis between human and mouse to identify key genes (pathways) involved in the occurrence of NSCLC. We automatically extracted the human-to-mouse orthologous interactions using the GeneWays system by natural language processing and further constructed molecular (gene and its products) networks by mapping the human-to-mouse interactions to NSCLC-related mammalian phenotypes, followed by module analysis using ClusterONE of Cytoscape and pathway enrichment analysis using the database for annotation, visualization and integrated discovery (DAVID) successively. A total of 70 genes were proven to be related to the mammalian phenotypes of NSCLC, and seven genes (ATAD5, BECN1, CDKN2A, FNTB, E2F1, KRAS and PTEN) were found to have a bearing on more than one mammalian phenotype (MP) each. Four network clusters centered by four genes thyroglobulin (TG), neurofibromatosis type-1 (NF1 ), neurofibromatosis type 2 (NF2 ) and E2F transcription factor 1 (E2F1) were generated. Genes in the four network modules were enriched in eight KEGG pathways (p value0.05), including pathways in cancer, small cell lung cancer, cell cycle and p53 signaling pathway. Genes p53 and E2F1 may play important roles in NSCLC occurrence, and thus can be considered as therapeutic targets for NSCLC.

We present a sensitive tracer method, suitable for in vivo human research, that uses β-[14C]carotene coupled with accelerator mass spectrometry (AMS) detection. Using this approach, the concentration-time course of a physiological (306 μg; 200 nCi) oral dose of β-[14C]carotene was determined for 209 days in plasma. Analytes included β-[14C]carotene, [14C]retinyl esters, [14C]retinol, and several [14C]retinoic acids. There was a 5.5-h lag between dosing and the appearance of 14C in plasma. Labeled β-carotene and [14C]retinyl esters rose and displayed several maxima with virtually identical kinetic profiles over the first 24-h period; elevated [14C]retinyl ester concentrations were sustained in the plasma compartment for >21 h postdosing. The appearance of [14C]retinol in plasma was also delayed 5.5 h postdosing and its concentration rose linearly for 28 h before declining. Cumulative urine and stool were collected for 17 and 10 days, respectively, and 57.4% of the dose was recovered in the stool within 48 h postdosing. The stool was the major excretion route for the absorbed dose. The turnover times (1/kel) for β-carotene and retinol were 58 and 302 days, respectively. Area under the curve analysis of the plasma response curves suggested a molar vitamin A value of 0.53 for β-carotene, with a minimum of 62% of the absorbed β-carotene being cleaved to vitamin A. In summary, AMS is an excellent tool for defining the in vivo metabolic behavior of β-carotene and related compounds at physiological concentrations. Further, our data suggest that retinyl esters derived from β-carotene may undergo hepatic resecretion with VLDL in a process similar to that observed for β-carotene.—Dueker, S. R., Y. Lin, B. A. Buchholz, P. D. Schneider, M. W. Lamé, H. J. Segall, J. S. Vogel, and A. J. Clifford. Long-term kinetic study of β-carotene, using accelerator mass spectrometry in an adult volunteer. J. Lipid Res. 2000. 41: 1790–1800.

Pharmacokinetics of physiologic doses of nutrients, pesticides, and herbicides can easily be traced in humans using a 14 C-labeled compound. Basic kinetics can be monitored in blood or urine by measuring the elevation in the 14 C content above the control predose tissue and converting to equivalents of the parent compound. High performance liquid chromatography (HPLC) is an excellent method for the chemical separation of complex mixtures whose profiles aAord estimation of biochemical pathways of metabolism. Compounds elute from the HPLC systems with characteristic retention times and can be collected in fractions that can then be graphitized for AMS measurement. Unknowns are tentatively identified by co-elution with known standards and chemical tests that reveal functional groupings. Metabolites are quantified with the 14 C signal. Thoroughly accounting for the carbon inventory in the LC solvents, ionpairing agents, samples, and carriers adds some complexity to the analysis. In most cases the total carbon inventory is dominated by carrier. Baseline background and stability need to be carefully monitored. Limits of quantitation near 10 amol of 14 C per HPLC fraction are typically achieved. Baselines are maintained by limiting injected 14 C activity

Localized folate deficiency may be a risk factor for cancer. Since, folate binding proteins (FBP) and reduced folate carrier proteins (RFC) mediate cellular transport of folate, we compared FBP concentrations in several organs from tumor-bearing transgenic (TBT) mice and tumor-free non-transgenic controls (NTC) of the same strain, age, and fed identical diets. Liver, spleen, brain, small intestine and kidney were individually homogenized in phosphate-buffered saline (PBS) and separated into membrane, cytoplasmic, mitochondrial/lysomal and nuclear fractions (confirmed with marker enzymes). Homogenates and fractions was analyzed for total protein, and FBP. We used rabbit anti-bovine milk antibody and ELISA to measure FBP. FBP concentrations in kidney, small intestine, and spleen of TBT mice were higher than those of NTC mice; the opposite was true in liver and lung. FBP seemed to be upregulated in kidneys (all fractions), small intestine (all fractions), and spleen (cytoplasmic and nuclear fractions only) of TBT mice compared to NTC mice; the opposite appeared true in liver (all fractions) and lung (all fractions). FBP concentrations in brain, heart, and muscle of TBT mice were not different from those in brain, heart and muscle of NTC mice. A longitudinal study will determine if these changes in FBP concentrations precede tumor onset.

In this paper, a hybrid scheme based on ray tracing method and the artificial neural networks for the field strength prediction is presented for the indoor environment. In the proposed scheme, ray tracing technique is used to coarsely predict the field strength according to the easily-acquired low accuracy geographical databases for the indoor scenarios. Then, the artificial neural networks are trained using measurement data or simulation data from fine geographical databases to compensate the effects caused by the detail geographical information in the propagation environments. In this way, high prediction accuracy is achieved with less running time. Simulation results reveal that using this hybrid method, the field strength is predicted in higher accuracy with less computation time.

This study was carried out to investigate the genetic polymorphism of nine short tandem repeat (STR) loci including D2S1772, D6S1043, D7S3048, D8S1132, D11S2368, D12S391, D13S325, D18S1364 and D22GATA198B05 in Chinese Han population of Henan province and to assess its value in forensic science. Genomic DNA was extracted by means of phenol-chloroform from 212 blood samples of unrelated healthy individuals in Henan Han population, and alleles were amplified with STRtyper-10F/G kit. The genotype distributions were in accordance with Hardy-Weinberg equilibrium (p>0.05). New core sequences were found in D2S1772, D7S3048, and D22GATA198B05 STR loci in Chinese Han population of Henan province, which were different from those of other populations. Two single-nucleotide polymorphism (SNP) sites were found at locus D18S1364 and D22GATA198B05, respectively. The heterozygosity (H), power of discrimination (PD), probability of exclusion (PE) and polymorphism information contents (PIC) ranged from 0.778 to 0.887, 0.928 to 0.967, 0.559 to 0.769 and 0.77 to 0.86, respectively. The total PD and combined PE of nine STR loci reached 0.999999999999363 and 0.999951, respectively. The nine STR loci are highly polymorphic in Chinese Han population of Henan province and they may be of great value in forensic science and human population genetics.Key words: short tandem repeat, repeat motif, genetic polymorphism, Han population, forensic genetics.

Background Botanical products are frequently used for treatment of nasal allergy. Three of these substances, Cinnamomum zeylanicum, Malpighia glabra, and Bidens pilosa, have been shown to have a number of anti-allergic properties in-vitro. The current study was conducted to determine the effects of these combined ingredients upon the nasal response to allergen challenge in patients with seasonal allergic rhinitis. Methods Twenty subjects were randomized to receive the combination botanical product, (CBP) 2 tablets three times a day, loratadine, 10 mg once a day in the morning, or placebo, using a randomized, double-blinded crossover design. Following 2 days of each treatment and during the third day of treatment, subjects underwent a nasal allergen challenge (NAC), in which nasal symptoms were assessed after each challenge dose and every 2 hours for 8 hours. Nasal lavage fluid was assessed for tryptase, prostaglandin D2, and leukotriene E4 concentrations and inflammatory cells. Results Loratadine significantly reduced the total nasal symptom score during the NAC compared with placebo (P = 0.04) while the CBP did not. During the 8 hour period following NAC, loratadine and the CBP both reduced NSS compared with placebo (P = 0.034 and P = 0.029, respectively). Analysis of nasal lavage fluid demonstrated that the CBP prevented the increase in prostaglandin D2 release following NAC, while neither loratadine nor placebo had this effect. None of the treatments significantly affected tryptase or leukotriene E4 release or inflammatory cell infiltration. Conclusion The CBP significantly reduced NSS during the 8 hours following NAC and marginally inhibited the release of prostaglandin D2 into nasal lavage fluid, suggesting potential clinical utility in patients with allergic rhinitis.

Lung cancer including non-small cell lung cancer (NSCLC) and small cell lung cancer is one of the most aggressive tumors with high incidence and low survival rate. The typical NSCLC patients account for 80–85 % of the total lung cancer patients. To systemically explore the molecular mechanisms of NSCLC, we performed a molecular network analysis between human and mouse to identify key genes (pathways) involved in the occurrence of NSCLC. We automatically extracted the human-to-mouse orthologous interactions using the GeneWays system by natural language processing and further constructed molecular (gene and its products) networks by mapping the human-to-mouse interactions to NSCLC-related mammalian phenotypes, followed by module analysis using ClusterONE of Cytoscape and pathway enrichment analysis using the database for annotation, visualization and integrated discovery (DAVID) successively. A total of 70 genes were proven to be related to the mammalian phenotypes of NSCLC, and seven genes (ATAD5, BECN1, CDKN2A, FNTB, E2F1, KRAS and PTEN) were found to have a bearing on more than one mammalian phenotype (MP) each. Four network clusters centered by four genes thyroglobulin (TG), neurofibromatosis type-1 (NF1 ), neurofibromatosis type 2 (NF2 ) and E2F transcription factor 1 (E2F1) were generated. Genes in the four network modules were enriched in eight KEGG pathways (p value

Background: A quantitative understanding of human folate metabolism is needed. Objective: The objective was to quantify and interpret human folate metabolism as it might occur in vivo. Design: Adults (n 13) received 0.5 nmol [ 14 C]pteroylmonoglutamate (100 nCi radioactivity) plus 79.5 nmol pteroylmonoglutamate in water orally. 14 C was measured in plasma, erythrocytes, urine, and feces for40 d. Kinetic modeling was used to analyze and interpret the data. Results: According to the data, the population was healthy and had a mean dietary folate intake of 1046 nmol/d, and the apparent dose absorption of 14 C was 79%. The model predictions showed that only 0.25% of plasma folate was destined for marrow, mean bile folate flux was 5351 nmol/d, and the digestibility of the mix (1046 5351 nmol/d) was 92%. About 33% of visceral pteroylmonoglutamate was converted to the polyglutamate form, most of the body folate was visceral (99%), most of the visceral folate was pteroylpolyglutamate (98%), total body folate was 225 mol, and pteroylpolyglutamate synthesis, recycling, and catabolism were 1985, 1429, and 556 nmol/d, respectively. Mean residence times were 0.525 d as visceral pteroylmonoglutamate, 119 d as visceral pteroylpolyglutamate, 0.0086 d as plasma folate, and 0.1 d as gastrointestinal folate. Conclusions: Across subjects, folate absorption, bile folate flux, and body folate stores were larger than prior estimates. Marrow folate uptake and pteroylpolyglutamate synthesis, recycling, and catabolism are saturable processes. Visceral pteroylpolyglutamate was an immediate precursor of plasma p-aminobenzoylglutamate. The model is a working hypothesis with derived features that are explicitly model-dependent. It successfully quantitated folate metabolism, encouraging further rigorous testing. Am J Clin Nutr 2004;80:680 –91.

2 Slow bone turnover rate and large day-to-day variation in excreted bone biomarkers create a challenge in assessing bone health in humans [1]. The use of the longlived radioisotope 41-calcium (41Ca; t1/2D»10 years), which has a rare natural abundance (41Ca/CaD»10i15), and accelerator mass spectrometry (AMS)1, which is able to detect 41Ca tracer, show great promise in resolving bone health issues [2–4]. However, sample processing for AMS measurements is a barrier to widespread Ca– AMS applications [5]. This communication summarizes an improved protocol for quantifying 41Ca concentrations in biological specimens. Calcium isotope tracers are present in multiple body pools. Saliva sampling is proposed as a noninvasive alternative to blood sampling in a week-long study of two subjects using stable Ca isotopes [6]. Urine is the ultimate noninvasive sample and is known to reXect average plasma levels [4], but high temporal resolution requires direct blood sampling. The previous AMS preparation protocol [4] did not address measurements of either saliva or serum specimens. Our protocol increases sample throughput at a reduced cost and expands routine 41Ca tracer determinations to a wider range of biological specimens including urine, serum, and saliva samples. Urine, fasting blood, and fasting saliva samples were collected at diVerent time points from a healthy post

We present the application of a nonparametric method to performing functional principal component analysis for functional curve data that consist of measurements of a random trajectory for a sample of subjects. This design typically consists of an irregular grid of time points on which repeated measurements are taken for a number of subjects. We introduce shrinkage estimates for the functional principal component scores that serve as the random effects in the model. Scatterplot smoothing methods are used to estimate the mean function and covariance surface of this model. We propose improved estimation in the neighborhood of and at the diagonal of the covariance surface, where the measurement errors are reflected. The presence of additive measurement errors motivates shrinkage estimates for the functional principal component scores. Shrinkage estimates are developed through best linear prediction and in a generalized version, aiming at minimizing one-curve-leave-out prediction error. The estimation of individual trajectories combines data obtained from that individual as well as all other individuals. We apply our methods to new data regarding the analysis of the level of 14C-folate in plasma as a function of time since dosing of healthy adults with a small tracer dose of 14C-folic acid. A time transformation was incorporated to handle design irregularity concerning the time points on which the measurements were taken. The proposed methodology, incorporating shrinkage and data-adaptive features, is seen to be well suited for describing population kinetics of 14C-folate-specific activity and random effects, and can also be applied to other functional data analysis problems.

The effect of vitamin A supplements on metabolic behavior of an oral tracer dose of [14C]beta-carotene was investigated in a longitudinal test-retest design in two adults. For the test, each subject ingested 1 nmol of [14C]beta-carotene (100 nCi) in an emulsified olive oil-banana drink. Total urine and stool were collected for up to 30 days; concentration-time patterns of [14C]beta-carotene, [14C]retinyl esters, and [14C]retinol were determined for 46 days. On Day 53, the subjects were placed on a daily vitamin A supplement (10000 IU/day), and a second dose of [14C]beta-carotene (retest) was given on Day 74. All 14C determinations were made using accelerator mass spectrometry. In both subjects, the vitamin A supplementation was associated with three main effects: 1). increased apparent absorption: test versus retest values rose from 57% to 74% (Subject 1) and from 52% to 75% (Subject 2); 2). an approximately 10-fold reduction in urinary excretion; and 3). a lower ratio of labeled retinyl ester/beta-carotene concentrations in the absorptive phase. The molar vitamin A value of the dose for the test was 0.62 mol (Subject 1) and 0.54 mol (Subject 2) vitamin A to 1 mol beta-carotene. Respective values for the retest were 0.85 and 0.74. These results show that while less cleavage of beta-carotene occurred due to vitamin A supplementation, higher absorption resulted in larger molar vitamin A values.

Nous proposons un modele stochastique pour la cinetiques de marquage de cellules avec un produit radiomarque. Ce modele est compose d'un modele parametrique pour la distribution du temps de penetration du marqueur dans les cellules et d'un modele non-parametrique de fonction de survie de la combinaison cellule-marqueur. L'objectif est de modeliser ainsi l'evolution au cours du temps de la fraction de cellules marquees parmi l'ensemble des cellules. Une experience recente avec des hematies et du folate radiomarque fournit des mesures longitudinales de cette fraction de cellules marquees. Le modele semi parametrique propose est ajuste a ces donnees et quelques unes des implications sont explorees. La methode proposee inclut egalement des inferences basees su le bootstrap.

To compare the therapeutic effects between CHOP-PVP and CHOP protocols for non-Hodgkin's lymphoma (NHL).Of 79 NHL patients, 40 received CHOP-PVP and 39 received CHOP protocol. Kaplan-Meier method was used for survival rate and Cox regression model for prognostic factors.The complete remission rate and overall response rate were 57.5% (23/40) and 87.5% (35/40) in CHOP-PVP group and they were 33.3% (13/39) and 69.2% (27/39) in CHOP group. There was a significant difference (P0.05) in the complete remission rate and overall response rate between the two groups. The main toxicity was myelosuppression. The leukocytopenia rate was 82.5% in CHOP-PVP group and 71.8% in CHOP group (P0.05) with no fatality in either group.CHOP-PVP protocol may be more effective for non-Hodgkin's lymphoma than CHOP protocol without increasing toxicity.

To investigate the effect of IL-12 on IFN-gamma and IL-10 production of peripheral blood mononuclear cells (PBMC) in chronic hepatitis B virus infection patients during IFN-alpha treatment.Before and after IFN-alpha treatment of 3 months and 6 months, PBMC of 20 patients with chronic hepatitis B virus infection were collected and cultured in vitro in the culture fluid containing PHA (100 microg/ml), HBcAg (1 microg/ml), or HBeAg (1 microg/ml) for 48 h under the condition of the presence or absence of IL-12 (10 ng/ml). Then the levels of IFN-gamma and IL-10 were determined by ELISA.There were 12 responders and 8 nonresponders to IFN-alpha treatment. In the responders, the enhancing effect of IL-12 on IFN-gamma production was significantly greater after IFN-alpha treatment than before the treatment. The production of IL-10 was suppressed in the presence of IL-12 after 3 months and 6 months of IFN-alpha treatment. In the same treatment time, the level of IFN-gamma in the presence of IL-12 was significantly higher than that in the absence of IL-12. To the nonresponders, the enhancing effect of IL-12 on IFN-gamma production was also significantly increased after IFN-alpha treatment. Moreover, in the same treatment time, the level of IFN-gamma in the presence of IL-12 was significantly higher than that in the absence of IL-12.The enhancing effect of IL-12 on IFN-gamma production of PBMC in patients with chronic hepatitis B virus infection is increased during IFN-alpha treatment. IFN-alpha and IL-12 may enhance the efficacy for the treatment of chronic hepatitis B virus infection.

Jun Li,1,* Lintao Bi,1 Yumei Lin,1,* Zhenxia Lu,1 Gang Hou2 1Department of Hematology and Oncology, China-Japan Union Hospital of Jilin University, Changchun,Jilin, People’s Republic of China; 2Department of Respiratory Medicine, The First Hospital of China Medical University, Shenyang, People’s Republic of China *These authors contributed equally tothis work Abstract: Multiple myeloma (MM) is a clonal malignancy characterized by the proliferation of malignant plasma cells in the bone marrow and the production of monoclonal immunoglobulin. In addition to genetic changes, gene hypermethylation is an alternative mechanism of tumor suppressor gene inactivation in MM. The cyclin-dependent kinase inhibitor 1 (CDKN2B or p15INK4B) gene lies adjacent to the tumor suppressor gene, cyclin-dependent kinase inhibitor 2 (CDKN2A), and is frequently mutated and deleted in a wide variety of tumors, including MM. However, there is a lack of systematic analysis of p15 epigenetic modification such as methylation in MM from different studies that can provide more powerful estimation of an effect. In this study, we have systematically reviewed the studies of p15INK4B promoter methylation in MM and quantified the association between p15INK4B promoter methylation and MM using meta-analysis methods. We observed that the frequency of p15INK4B methylation is significantly higher in MM patients than in normal healthy controls. The pooled odds ratio (OR) from ten studies including 394 MM and 99 normal individuals is 0.08, while confidence interval (CI) is 0.03–0.21 (P

University collaborations and internal research programs that trace isotopically labeled compounds in natural biological systems have grown significantly in the past few years. New research in molecular nutrition, protein sequencing, immunoassays, and toxicology now require hundreds to thousands of sample analyses per project. The goal of this effort was to strengthen this Laboratory and University health related research by the expansion of AMS access. This was achieved by our design and implementation of an AMS spectrometer that analyzes isotopic ions at lower energies in a more compact spectrometer without sacrificing precision or throughput. The decrease in ion energies is accompanied by a significant reduction in size and cost of the spectrometer. Our successful reduction in spectrometer cost, operation, and space will make this technology more appealing to research institutions, including industrial research centers. While others have also developed smaller spectrometers, these are limited in precision and throughput by the much lower intensities of ion beams that can be transmitted through them without differential loss of isotope species. The primary challenge in this project was mating the LLNL-designed high intensity negative ion source (Roberts, et al. 1994; Southon & Roberts, 2000) to available accelerator components and then showing that the precisionmore » and throughput would remain high enough to serve the research that needs large numbers of AMS analyses. The project also required reduction in operating complexity so that scientists and students would not require technical specialists to make their measurements. This report describes the experiments done to assure the needed spectrometer performance.« less

{beta}-Carotene is a tetraterpenoid distributed widely throughout the plant kingdom. It is a member of a group of pigments referred to as carotenoids that have the distinction of serving as metabolic precursors to vitamin A in humans and many animals [1,2]. We used Accelerator Mass Spectrometry (AMS) [3] to determine the metabolic behavior of a physiologic oral dose of {beta}-[{sup 14}C]carotene (200 nanoCuries; 0.57 {micro}mol) in a healthy human subject. Serial blood specimens were collected for 210-d and complete urine and feces were collected for 17 and 10-d, respectively. Balance data indicated that the dose was 42% bioavailable. The absorbed {beta}-carotene was lost slowly via urine in accord with the slow body turnover of {beta}-carotene and vitamin A [4]. HPLC fractionation of plasma taken at early time points (0-24-h) showed the label was distributed between {beta}-carotene and retinyl esters (vitamin A) derived from intestinal metabolism.

Whole blood folate level is a superior indicator of folate nutritional status than serum/plasma level. Problems with and lack of confidence in results of current whole blood folate assays have limited its popularity for assessing folate nutritional status. Here, an acid extraction GCMS detection method that measures total folate whole blood is presented. Folates are released from the matrix of whole blood and cleaved to para-aminobenzoic acid (pABA) by acid hydrolysis in the presence of [(13)C(6)]pABA as internal standard (IS). The hydrolysate is passed over a C18 resin to remove heme. The pABA isotopomers are ethyl esterified, isolated on C18 resin, and trifluoroacetylated. Following normal-phase HPLC separation, the isotopomers are silylated to their tBDMS derivatives. The abundance of these derivatives are measured at m/z 324 for [(13)C(6)]pABA as IS and m/z 318 for pABA from whole blood folate. Our method uses readily available chemicals and our results agree well with those using Lactobacillus casei, the current gold standard reference assay. The presence of folate analogs (methotrexate) or antibacterials (sulfonamines) does not affect our method. This feature makes it useful in monitoring folate status of patients undergoing chemotherapy. Before using our method, pABA supplements must be discontinued for a few days.

BACKGROUND Blood beta-carotene and vitamin A responses to oral beta-carotene are variable in humans. Some individuals are characterized as responders and others as low- or nonresponders. A better understanding of the conditions that produce the variability is important to help design public health programs that ensure vitamin A sufficiency. OBJECTIVE Our objective was to assess variability in absorption and conversion of beta-carotene to vitamin A in vivo in humans by using a novel double-tracer ?hexadeuterated (D(6)) beta-carotene and D(6) retinyl acetate approach. DESIGN Eleven healthy women were housed at the US Department of Agriculture Western Human Nutrition Research Center metabolic unit for 44 d, where they consumed diets adequate in vitamins and minerals except for carotenoids. After an adaptation period, the women were given 30 micromol D(6) retinyl acetate orally, followed 1 wk later with 37 micromol D(6) beta-carotene (approximately equimolar doses). Time-dependent plasma concentration curves were determined for D(6) retinol, D(6) beta-carotene, and trideuterated (D(3)) retinol (derived from D(6) beta-carotene). RESULTS Mean (+/-SE) absorption of D(6) beta-carotene was 3.3 +/- 1.3% for all subjects. The mean conversion ratio was 0.81 +/- 0.34 mol D(3) retinol to 1 mol D(6) beta-carotene for all subjects. However, only 6 of the 11 subjects had plasma D(6) beta-carotene and D(3) retinol concentrations that we could measure. The mean absorption of D(6) beta-carotene in these 6 subjects was 6.1 +/- 0.02% and their conversion ratio was 1.47 +/- 0.49 mol D(3) retinol to 1 mol D(6) beta-carotene. The remaining 5 subjects were low responders with

Under states of protein deficiency, the dietary limiting amino acid, rather than protein content, can act as the dietary stimulus to control diet selection. If fact, threonine-deficient rats will alter their diet selection patterns solely on the basis of very small changes (0.009 g/100 g) in the dietary threonine concentration. In these studies, we assessed whether lysine-deficient rats will also alter their diet selection patterns on the basis of small changes in dietary Lys concentration. In all experiments, growing rats were adapted to diets in which the protein fraction (purified amino acids or wheat gluten) was limiting in Lys. They were then given a choice between the adaptation diet (AD) diet and a slightly more deficient diet. Rats that were adapted to a Lys-deficient diet (0.25 g Lys/100 g) selected their AD over diets containing as little as 0.01% less Lys (P < 0.01) within 5 d. To determine how deficient rats must be before they alter their selection patterns, rats were adapted to diets containing various levels of Lys, i.e., 2 levels below the requirement for growth and 2 levels above the requirement for growth, but below the requirement for maximal nitrogen retention. Only rats adapted to diets containing Lys below their requirement for growth selected their AD over a diet containing 0.05% less Lys (P < 0.005). Finally, to determine whether rats will alter their selection to whole protein-based diets, rats were adapted to 25% wheat gluten diets supplemented with 0.03-0.21% Lys. Rats selected the AD over a diet containing as little as 0.09% less supplemental Lys by d 4 of the trial (P < 0.05). We conclude that rats are sensitive to changes as small as 0.01% in dietary Lys concentration, but that sensitivity requires prior adaptation to Lys-deficient diets.

Global temperatures are rising, and concerns about the response of agricultural production to climate change are increasing. Adaptation is a key factor that will shape the severity of impacts of future climate change on food production. Based on actual meteorological, soil and agricultural management data at site scale, the CERES-Rice model, combined with the Regional Climate Model (RCM)-PRECIS, was used to simulate both the effects of climate change on rice yields and the efficacy of adaptive options in Northeast China. The impact simulation showed that rice yield changes ranged from +0.1% to –44.9% (A2 scenario) and from –0.3% to –40.1% (B2 scenario) without considering CO2 fertilisation effects. When considering CO2 fertilisation effects, rice yield reductions induced by temperature increases were decreased at all sites. The CO2 fertilisation effects may partly offset the negative impacts of climate change on rice yields. Adaptive option results revealed that the adverse impacts of climate change on rice yields could be mitigated by advancing the planting dates, transplanting mid–late-maturing rice cultivars to replace early-maturing ones, and breeding new rice cultivars with high thermal requirements. Our findings provide insight into the possible impacts of climate change on rice production, and we suggest which adaptive strategies could be used to cope with future climate change, thus providing evidence-based suggestions for government policy on adaptive strategies.

This noninvasive method for collection and analysis of a wide range of aldehydes and ketones in human breath may enable assessment of lipid peroxidation and metabolic status in vivo. Breath samples are drawn through silica cartridges impregnated with 2,4-dinitrophenylhydrazine, which traps carbonyls as their hydrazone derivatives. The hydrazone derivatives are eluted from the cartridges with acetonitrile, separated by reversed-phase HPLC, and quantified spectrophotometrically. Using this method, we have measured formaldehyde, acetaldehyde, acetone, propanal, 2-butanone, butanal, pentanal, and hexanal. Recoveries of carbonyls added to Douglas bags were > 90%, except for 2-butanone, which was 86.2%. The overall CVs for sampling plus analyzing duplicate aliquots of breath were < 11%. The results indicate that this protocol can be used to monitor changes of carbonyl production by analyzing expired air, which may, with further study, indicate physiological and pathological status.