PRAME promotes in vitro leukemia cells death by regulating S100A4/p53 signaling

OBJECTIVE

PRAME (Preferentially Expressed Antigen in Melanoma) is a tumor-associated antigen recognized by immunocytes, and it induces cytotoxic T cell-mediated responses in melanoma. PRAME is expressed in a wide variety of tumors, but in contrast with most other tumor-associated antigens, it is also expressed in leukemias. The physiologic role of PRAME remains elusive. Recently, it has found PRAME could be involved in the regulation of cell death in leukemias, but the mechanism of the function is unclear. Here, we confirm that PRAME induces leukemias cell death by regulation of S100A4/p53 signaling.

MATERIALS AND METHODS

The pCDNA3-PRAME plasmid and its control were transfected with the KG-1 cells. The pCDNA3-PRAME transfected KG-1 cells were then transiently transfected with S100A4 cDNA or wt-p53 siRNA. The PRAME siRNA and its control were transfected with the K562 cells. The PRAME siRNA transfected K562 cells were then transiently transfected with S100A4 siRNA or pGMp53-Lu. PRAME, S100A4 and P53 were detected by Western blot assay in different time point. Annexin V/propidium iodide and MTT methods were used to detect apoptosis and cell survival rate.

RESULTS

KG-1 cells overexpressing the PRAME gene significantly induces apoptosis and decreases proliferation in vitro, followed by down-regulation of S100A4 and up-regulation of p53. Up-regulation of S100A4 by S100A4 transfection inhibits PRAME-induced p53 up-regulation. Furthermore, up-regulation of S100A4 by S100A4 transfection or down-regulation of p53 by p53 siRNA transfection reduces apoptosis and increases proliferation in vitro. Knockdown of PRAME in K562 cells significantly increases proliferation in vitro, followed by up-regulation of S100A4 and down-regulation of p53. The downregulation of S100A4 by S100A4 siRNA transfection increased p53 expression. Furthermore, downregulation of S100A4 by S100A4 siRNA transfection or up-regulation of p53 by p53 transfection decreases proliferation in vitro.

CONCLUSIONS

Our results suggest that the leukemias expressing high levels of PRAME has a favorable prognosis. PRAME promotes in vitro leukemia cells death by regulating S100A4/p53 signaling.

Reduced Penetrance of PRRT2 Mutation in a Chinese Family With Infantile Convulsion and Choreoathetosis Syndrome

Paroxysmal kinesigenic dyskinesia is a rare episodic movement disorder that can be isolated or associated with benign infantile seizures as part of choreoathetosis syndrome. Mutations in the PRRT2 gene have been recently identified as a cause of paroxysmal kinesigenic dyskinesia and infantile convulsion and choreoathetosis (ICCA). We reported a PRRT2 heterozygous mutation (c.604-607delTCAC, p.S202Hfs*25) in a 3-generation Chinese family with infantile convulsion and choreoathetosis and paroxysmal kinesigenic dyskinesia. The mutation was present in 5 family members, of which 4 were clinically affected and 1 was an obligate carrier with reduced penetrance of PRRT2. The affected carriers of this mutation presented with a similar type of infantile convulsion during early childhood and developed additional paroxysmal kinesigenic dyskinesia symptoms later in life. In addition, they all had a dramatic clinical response to oxcarbazepine/phenytoin therapy. Reduced penetrance of the PRRT2 mutation in this family could warrant genetic counseling.

Identification and characterisation of tobacco microRNA transcriptome using high-throughput sequencing

MicroRNAs (miRNAs) are post-transcriptional regulators that are involved in numerous biological processes in plants. In this study, we investigate miRNAs in Honghua Dajinyuan, an agronomically important species of tobacco in China. Here, we report a comprehensive analysis of miRNA expression profiles in the leaf, stem and root using a high-throughput sequencing approach. A total of 165 miRNAs, representing 55 conserved families, and 50 novel miRNAs, representing 19 families, were identified in three libraries. In addition, 12 miRNAs were randomly selected from a differentially expressed conserved miRNA family in three libraries with expression alterations and subjected to qRT-PCR validation. Of these, the expression level of nta-miR167d is highly enriched in the leaf tissue. In addition, the expression level of nta-miR319a is prominently enriched in the stem, while nta-miR160c is highly enriched in the root. Moreover, the target prediction showed that most of the targets coded for transcription factors that are involved in cellular and metabolic processes. GO analysis showed that most of the targets were involved in organelle function, served binding functions, and take part in cellular and metabolic processes. This study helps shed new light on understanding the role of miRNAs in different parts of the tobacco plant and adds a significant number of novel miRNAs to the tobacco miRNA transcriptome.

Prevalence and awareness of diabetes mellitus among a rural population in China: results from Liaoning Province

AIM

To clarify the diabetes prevalence trends among the rural population in northern China.

METHODS

All eligible permanent residents aged ≥ 35 years in selected rural villages of Liaoning province were invited to participate in the study. A total of 11 600 people completed all questionnaires and were included in the study. The response rate was 85.3%. Fasting plasma glucose levels were measured after at least 12 h of fasting and diabetes was diagnosed according to WHO criteria, i.e. fasting plasma glucose ≥ 7 mmol/l and/or being on treatment for diabetes. Impaired fasting glucose was defined according to the 1997 and the 2010 American Diabetes Association (ADA) criteria (6.1-6.9 and 5.6-6.9 mmol/l, respectively). Previous diagnoses of diabetes were assessed on the basis of self-reports.

RESULTS

The prevalence of diabetes among adults in the rural population was 10.6% (10.0% in men and 11.1% in women). The prevalence of impaired fasting glucose was 13.0 and 36.1% according to the 1997 and the 2010 ADA criteria, respectively. The prevalence of previously diagnosed diabetes was 4.3% among the whole population (3.3% in men and 5.1% in women). The prevalence of previously diagnosed diabetes was 34.8% in men and 50.2% in women. Only 29.6% of men and 42% of women with diabetes had taken oral hypoglycaemic agents or insulin to lower their blood sugar. In multivariate analysis, age, drinking habits, BMI, dyslipidaemia and family history of diabetes were identified as independent risk factors for diabetes, and occupational physical activity, smoking and lean meat intake were identified as independent protective factors for diabetes.

CONCLUSIONS

The prevalence of diabetes and impaired fasting glucose were found to be high in this rural population. Although the rate of treatment of people with diabetes has increased, the glycaemic control rate was still at a low level.

Meta-analyses of seven GIGYF2 polymorphisms with Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder that affects ~2% of the global population aged ≥65 years. Grb10-interacting GYF protein-2 (GIGYF2) can influence the development of PD through the regulation of insulin-like growth factor-1. The aim of the present meta-analysis study was to establish the contribution of GIGYF2 polymorphisms to PD. The study was conducted based on nine eligible studies consisting of 7,246 PD patients and 7,544 healthy controls. The results indicated that the GIGYF2 C.3630A>G polymorphism increased the risk of PD by 37% [P=0.008; odds ratio (OR), 1.37; 95% confidence interval (CI), 1.08-1.73] and that the GIGYF2 C.167G>A polymorphism was significantly associated with PD (P=0.003; OR, 3.67; 95% CI, 1.56-8.68). The meta-analyses of the other five GIGYF2 polymorphisms (C.1378C>A, C.1554G>A, C.2940A>G, C.1370C>A and C.3651G>A) did not reveal any significant associations. The present meta-analyses of the GIGYF2 genetic polymorphisms may provide a comprehensive overview of this PD candidate gene for future studies.

Significant association between TAP2 polymorphisms and rheumatoid arthritis: a meta-analysis

Background

Rheumatoid arthritis (RA) is a severe chronic immune mediated inflammatory disease that has been shown to be associated with human leukocyte antigen (HLA) loci. The transporter associated with antigen processing 2 (TAP2) has been identified to play an important role in the HLA-associated diseases and immune response. The goal of our meta-analysis was to summarize the contribution of TAP2 polymorphisms to the risk of RA.

Methods

Meta-analyses were performed between RA and 3 TAP2 coding polymorphisms that comprised TAP2-379Ile > Val (rs1800454), TAP2-565Ala > Thr (rs2228396) and TAP2-665Thr > Ala (rs241447). The meta-analyses were involved with 9 studies (24 individual studies) among 973 cases and 965 controls.

Results

Meta-analyses showed that TAP2-379Ile allele was significantly associated with an increased risk of RA (p = 0.0002, odds ratio (OR) = 1.44, 95% confidence interval (CI) = 1.18-1.74). This association was further shown only in the dominant model (p = 0.006, OR = 1.59, 95% CI = 1.14-2.22). Subgroup analyses by ethnicity revealed that the association of TAP2-379Ile was significant in Asians (p = 0.03, OR = 1.38, 95% CI = 1.04-1.83). In addition, another significant association of TAP2-565Thr allele with RA was observed in Europeans (p = 0.002, OR = 1.62, 95% CI = 1.20-2.20).

Conclusions

Our meta-analyses suggested that TAP2-379Ile allele was significantly associated with a 59% increased risk in the dominant effect model. Subgroup analyses by ethnicity showed that TAP2-379-Ile increased the risk of RA by 38% in Asians and TAP2-565Thr increased the risk of RA by 38% in Europeans.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2097080313124700

Association of NQO1 and TNF polymorphisms with Parkinson's disease: A meta-analysis of 15 genetic association studies

Parkinson's disease (PD) is a neurodegenerative movement d'isorder that affects ~2% of the population aged ≥65 years. NAD(P)H-quinone oxidoreductase 1 (NQO1) and tumor necrosis factor-α (TNF-α) are two important factors in the generation of oxidative stress in PD. The aim of the present study was to assess the association of NQO1 and tumor necrosis factor (TNF) polymorphisms with PD. A meta-analysis was performed that included data from 15 studies comprising 2,858 patients and 2,907 healthy controls. The results showed that TNF-1031 (rs1799964) was significantly associated with PD in the recessive [P=0.0005; odds ratio (OR), 3.19; 95% confidence interval (CI), 1.66-6.13] and additive models (P=0.0006; OR, 3.15; 95% CI, 1.63-3.51). However, there was no significant association in NQO1 C609T (rs1800566) and TNF-308 (rs1800629) with PD. To the best of our knowledge, the present study is the first meta-analysis of NQO1 and TNF polymorphisms with PD demonstrating that TNF-1031 polymorphism may be a risk factor for PD under either the recessive or additive models. However, the meta-analyses did not support the involvement of NQO1 C609T and TNF-308 in the risk of PD.

Polymorphisms of DRD2 and DRD3 genes and Parkinson's disease: A meta-analysis

Parkinson's disease (PD) is the second most common neurodegenerative disorder that affects ~2% of the population aged ≥65 years. The degeneration of dopamine neurons in the substantia nigra contributes to the pathogenesis of PD. Dopamine receptor D2 (DRD2) and dopamine receptor D3 (DRD3) are two key subtypes of dopamine receptors. The aim of our study was to evaluate the association between the polymorphisms of DRD2 and DRD3 genes and PD. Meta-analyses were conducted from 16 studies (46 stages) among 4,279 cases and 5,661 controls between PD and 9 polymorphisms (DRD2: rs1800497, rs1079597, rs6278, rs6279, rs273482, rs1799732 and rs1076563; DRD3: rs6280 and rs2134655). A significant association was observed between DRD3 rs2134655 polymorphism and PD [P=0.01, odds ratio (OR)=1.17, 95% confidence interval (CI): 1.03-1.32] and a borderline association was observed between DRD2 rs1800497 polymorphism and PD in Europeans (P=0.05, OR=1.13, 95% CI: 1.00-1.27). Findings of the current meta-analysis suggested that DRD3 rs2134655 polymorphism was associated with a 17% increased risk of PD and that DRD2 rs1800497 polymorphism had a potential to increase the risk of PD by 13% in Europeans. Future large-scale studies are required to confirm the ethnic difference of DRD2 rs1800497 polymorphism and to determine whether there were significant associations of PD with other polymorphisms in DRD2 and DRD3 genes.

Long-term self-renewal of human pluripotent stem cells on peptide-decorated poly(OEGMA-co-HEMA) brushes under fully defined conditions

Realization of the full potential of human induced pluripotent stem cells (hiPSC) in clinical applications requires the development of well-defined culture conditions for their long-term growth and directed differentiation. This paper describes a novel fully defined synthetic peptide-decorated substrate that supports self-renewal of hiPSC in commercially available xeno-free, chemically defined medium. The Au surface was deposited by a poly(OEGMA-co-HEMA) film, using the surface-initiated polymerization method (SIP) with the further step of carboxylation. The hiPSC generated from umbilical cord mesenchymal cells were successfully cultured for 10 passages on the peptide-tethered poly(OEGMA-co-HEMA) brushes for the first time. Cells maintained their characteristic morphology, proliferation and expressed high levels of markers of pluripotency, similar to the cells cultured on Matrigel™. Moreover, the cell adhesion could be tuned by the pattern and peptide concentration on the substrate. This well-defined, xeno-free and safe substrate, which supports long-term proliferation and self-renewal of hiPSC, will not only help to accelerate the translational perspectives of hiPSC, but also provide a platform to elucidate the underlying molecular mechanisms that regulate stem cell proliferation and differentiation via SIP technology.

Stabilization by hydrophobic protection as a molecular mechanism for organic carbon sequestration in maize-amended rice paddy soils

The hydrophobic components of soil organic matter (SOM) are reckoned to play an important role in the stabilization of soil organic carbon (SOC). The contribution of hydrophobic substances to SOC sequestration was evaluated in four different paddy soils in the South of China, following a 6-month incubation experiment with maize straw amendments. Soil samples included: a well developed paddy soil (TP) derived from clayey lacustrine deposits in the Tai Lake plain of Jiangsu; an acid clayey paddy soil (RP) derived from red earth in the rolling red soil area of Jiangxi; a weakly developed neutral paddy soil (PP) formed on Jurassic purple shale from Chongq; and a calcic Fluvisol (MS) derived from riverine sediments from a wetland along the Yangtze valley of Anhui, China. The SOC molecular composition after 30 and 180 days of incubation, was determined by off-line thermochemolysis followed by gas chromatography-mass spectrometry analysis. Lignin, lipids and carbohydrates were the predominant thermochemolysis products released from the treated soils. A selective preservation of hydrophobic OM, including lignin and lipids, was shown in maize amended soils with prolonged incubation. The decomposition of lignin and lipids was significantly slower in the TP and RP soils characterized by a larger content of extractable iron oxyhydrates (Fed) and lower pH. The overall increase in hydrophobic substances in maize incubated samples was correlated, positively, with total content of clay and Fed, and, negatively, with soil pH. Moreover, yields of both lignin and lipid components showed a significant relationship with SOC increase after incubation. These findings showed that the larger the lipid and lignin content of SOM, the greater was the stability of SOC, thereby suggesting that OM hydrophobic components may have an essential role in controlling the processes of OC sequestration in paddy soils of South China.

Microbial degradation of microcystin-LR by Ralstonia solanacearum

A bacterial strain was isolated from Lake Dianchi (China) and its degradability and degradative pathways of the cyanobacterial toxin microcystin-LR (MC-LR) were studied. On the basis of morphological, physiological and biochemical tests, the strain was identified as Ralstonia solanacearum. The acute oral toxicity tests showed that Ralstonia solanacearum belongs to a non-toxic class. This bacterium degraded MC-LR at the rate of 9.4 mg/L per day, which was higher than those of the other bacterial strains reported in the literature. As for the degradative pathways, the results showed that the Adda-Arg peptide bond of MC-LR was initially hydrolysed by Ralstonia solanacearum to form a linear molecule as an intermediate. The intermediate product subsequently underwent a cyclisation reaction via dehydration to form a final product with a small peptide ring at one end of the molecule. These biodegradative pathways were different from those reported with other bacterial strains, suggesting that MC-LR may undergo different transformations, and different products were formed due to different compositions of bacteria present in natural lakes and reservoirs. These results suggest that there is a significant potential for Ralstonia solanacearum as a degrader for MC-LR removal from wastewater.

Surface modification of Ti-6Al-4V alloy for biomineralization and specific biological response: Part I, inorganic modification

Titanium and its alloys represent the gold standard for orthopaedic and dental prosthetic devices, because of their good mechanical properties and biocompatibility. Recent research has been focused on surface treatments designed to promote their rapid osteointegration also in case of poor bone quality. A new surface treatment has been investigated in this research work, in order to improve tissue integration of titanium based implants. The surface treatment is able to induce a bioactive behaviour, without the introduction of a coating, and preserving mechanical properties of Ti6Al4V substrates (fatigue resistance). The application of the proposed technique results in a complex surface topography, characterized by the combination of a micro-roughness and a nanotexture, which can be coupled with the conventional macro-roughness induced by blasting. Modified metallic surfaces are rich in hydroxyls groups: this feature is extremely important for inorganic bioactivity (in vitro and in vivo apatite precipitation) and also for further functionalization procedures (grafting of biomolecules). Modified Ti6Al4V induced hydroxyapatite precipitation after 15 days soaking in simulated body fluid (SBF). The process was optimised in order to not induce cracks or damages on the surface. The surface oxide layer presents high scratch resistance.

EURADOS coordinated action on research, quality assurance and training of internal dose assessments

EURADOS working group on 'Internal Dosimetry (WG7)' represents a frame to develop activities in the field of internal exposures as coordinated actions on quality assurance (QA), research and training. The main tasks to carry out are the update of the IDEAS Guidelines as a reference document for the internal dosimetry community, the implementation and QA of new ICRP biokinetic models, the assessment of uncertainties related to internal dosimetry models and their application, the development of physiology-based models for biokinetics of radionuclides, stable isotope studies, biokinetic modelling of diethylene triamine pentaacetic acid decorporation therapy and Monte-Carlo applications to in vivo assessment of intakes. The working group is entirely supported by EURADOS; links are established with institutions such as IAEA, US Transuranium and Uranium Registries (USA) and CEA (France) for joint collaboration actions.

BP neural network classification for bleeding detection in wireless capsule endoscopy

Bleeding in the digestive tract is one of the most common gastrointestinal tract (GI) diseases, as well as the complication of some fatal diseases. Wireless capsule endoscopy (WCE) allows physicians to noninvasively examine the entire GI tract. However it is very laborious and time-consuming to inspect large numbers of WCE images, which limits the wider application of WCE. It is therefore important to develop an automatic and intelligent computer-aided bleeding detection technique. In this paper, a new method aimed at bleeding detection in WCE images is proposed. Colour texture features distinguishing the bleeding regions from non-bleeding regions are extracted in RGB and HSI colour spaces; then a neural network using the colour texture features as the feature vector inputs is designed to recognize the bleeding regions. The experiments demonstrate that the bleeding regions can be correctly recognized and clearly marked out. The sensitivity of the algorithm is 93% and the specificity is 96%.

Structural and functional characterization of a pollen-specific promoter NTPp13 in tobacco

A novel 407 bp nucleotide sequence NTPp13 was isolated from tobacco (Nicotiana tabacum L.) by PCR, its structure and function were characterized. The NTPp13 sequence was highly homologous with the pollen-specific expression promoter Zm13 from maize (Zea mays L.) and contained some key motifs which controlled pollen-specific expression. The NTPp13 was fused to the beta-glucuronidase (GUS) reporter gene and transferred into tobacco. Analysis of the transgenic plants revealed that this putative promoter fragment was sufficient to direct GUS expression specifically in the anther, exactly in the pollen and pollen tube, and that GUS activity reached the maximum at the stage of pollen grain began to separate. Further study showed that the expression of NTPp13 sequence at pollen was stable at the range of temperature measured. These data suggested that the NTPp13 sequence was likely the essential element of promoter region of an unknown pollen-specific gene from tobacco.

The role of Zn in the interplay among Langmuir–Blodgett multilayer and myelin basic protein: a quantitative analysis of XANES spectra

We have performed a quantitative analysis of the X-ray absorption near-edge structure (XANES) spectra at the Zinc K-edge of systems formed by phospholipid Langmuir-Blodgett multilayers (LBMLs) in the presence and in the absence of myelin basic protein (MBP) and in two hydration conditions. These spectra have been analysed by a new procedure called Minuit XANes (MXAN) which is able to perform a quantitative fit of XANES data in terms of structural parameters. By this method, we have been able to correlate the relevant differences between the spectra observed in the XANES range with the coordination changes due to reduction of the space around the Zinc when the level of hydration is lowered and/or the myelin basic protein is added. These spectral differences are peculiar of the XANES energy range, and are not present in the extended X-ray absorption fine structure (EXAFS) energy range where the analysis was previously performed. With this investigation, we give an unambiguous answer to the question of the role of zinc in such complexes by showing that the metal interacts with both the phospholipid heads of the substrate and the myelin basic protein.

Leukocyte 8-hydroxydeoxyguanosine and aromatic DNA adduct in coke-oven workers with polycyclic aromatic hydrocarbon exposure

OBJECTIVE

To investigate the potential for exposure to polycyclic aromatic hydrocarbons (PAHs) to induce oxidative DNA damage, we conducted a cross-sectional study in coke-oven workers employed at an iron-steel factory.

METHODS

The study population contained 119 coke-oven workers from different work areas of the oven and 38 controls. Personal information on age, employment duration, smoking habit and alcohol consumption was obtained at an interview. Leukocyte 8-hydroxydeoxyguanosine (8-OHdG) was measured by high performance liquid chromatography with electrochemical detection. Leukocyte aromatic DNA adducts as effective dose, and urinary 1-hydroxypyren as internal dose, were also measured, and used to analyze the relationship of 8-OHdG with other biomarkers for PAH exposure, tobacco smoke and alcohol consumption.

RESULTS

The leukocyte 8-OHdG revealed a wide inter-individual variation. The highest 8-OHdG level was detected in bottom-workers of the coke-oven. There were significant differences among the four different work areas ( P=0.02). We could not find significant correlation between 8-OHdG levels and urinary 1-hydroxypyrene, but a weakly positive correlation was found between 8-OHdG and leukocyte aromatic DNA adducts among all subjects (r=0.19 P=0.03). We could not observe any effect of smoking and alcohol drinking on 8-OHdG production.

CONCLUSION

We could not find clear evidence that PAH exposure induces oxidative DNA damage.

The solid-solution partitioning of heavy metals (Cu, Zn, Cd, Pb) in upland soils of England and Wales

Ninety-eight surface soils were sampled from the uplands of England and Wales, and analysed for loss-on-ignition (LOI), and total and dissolved base cations, Al, Fe, and trace heavy metals (Cu, Zn, Cd, Pb). The samples covered wide ranges of pH (3.4-8.3) and LOI (9-98%). Soil metal contents measured by extraction with 0.43 mol l-1 HNO3 and 0.1 mol l-1 EDTA were very similar, and generally lower than values obtained by extraction with a mixture of concentrated nitric and perchloric acids. Total heavy metal concentrations in soil solution depend positively upon soil metal content and [DOC], and negatively upon pH and LOI, values of r2 ranging from 0.39 (Cu) to 0.81 (Pb). Stronger correlations (r2=0.76-0.95) were obtained by multiple regression analysis involving free metal ion (Cu2+, Zn2+, Cd2+, Pb2+) concentrations calculated with the equilibrium speciation model WHAM/Model VI. The free metal ion concentrations depend positively upon MHNO3 and negatively upon pH and LOI. The data were also analysed by using WHAM/Model VI to describe solid-solution interactions as well as solution speciation; this involved calibrating each soil sample by adjusting the content of "active" humic matter to match the observed soil pH. The calibrated model provided fair predictions of total heavy metal concentrations in soil solution, and predicted free metal ion concentrations were in reasonable agreement with the values obtained from solution-only speciation calculations.

Characterization of pyridine nucleotide coenzymes in the hyperthermophilic archaeon Pyrococcus furiosus

Pyridine-type nucleotides were identified in cell-free extracts of the hyperthermophilic archaeon Pyrococcus furiosus by their ability to replace authentic nicotinamide adenine dinucleotide (phosphate) [NAD(P)] in assays using pure P. furiosus enzymes. The nucleotides were purified using a combination of ion-exchange and reverse-phase chromatography. They were identified as NAD and NADP by analyses using liquid chromatography-mass spectrometry and high performance liquid chromatography. Their intracellular concentrations were measured in P. furiosus grown using maltose and peptides as the carbon sources. The concentrations decreased during the lag phase but remained constant during the exponential phase at approximately 0.17 and 0.13 mM, respectively. The amount of NAD was significantly lower (more than four-fold lower) than that in mesophilic bacteria, although the NADP concentration was comparable. The internal concentrations of NADH and NADPH in P. furiosus were determined to be 0.14 mM and 0.04 mM, respectively. The overall cellular concentration of NAD(P)(H) in P. furiosus (0.48 mM) is about half the value in the mesophiles. The NAD(H)/NADP(H) ratio in P. furiosus is consistent with the preferred use of NADP by several catabolic enzymes that have been purified from this organism. The mechanisms by which hyperthermophiles stabilize these thermally labile nicotinamide nucleotides are not known.