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PubMed2005

Botanical and dietary supplements for menopausal symptoms: what works, what does not.

BACKGROUND: Approximately two thirds of women who reach menopause develop menopausal symptoms, primarily hot flashes. Hormone therapy long was considered the first-line treatment for vasomotor symptoms. However, given the results of the Women's Health Initiative (WHI), many women are reluctant to use exogenous hormones for symptomatic treatment and are turning to botanicals and dietary supplement (BDS) products for relief. Despite the fact that there is limited scientific evidence describing efficacy and long-term safety of such products, many women find these natural treatments appealing. Perimenopausal and postmenopausal women are among the highest users of these products, but 70% of women do not tell their healthcare providers about their use. Compounding this issue is the fact that few clinicians ask their patients about use of BDS, largely because they have not been exposed to alternative medical practices in their training and are unfamiliar with these products. METHODS: This paper reviews the botanicals and dietary supplements commonly used in menopause (such as black cohosh, red clover, and soy products) as well as the available data on efficacy and safety. We searched the MEDLINE database from 1966 to December 2004 using terms related to BDS and menopausal symptoms for perimenopausal or postmenopausal women. Abstracts from relevant meetings as well as reference books and websites on herbal supplements were also searched. Randomized, controlled trials (RCTs) were used if available; open trials and comparison group studies were used when RCTs were not available. RESULTS AND CONCLUSIONS: The evidence to date suggests that black cohosh is safe and effective for reducing menopausal symptoms, primarily hot flashes and possibly mood disorders. Phytoestrogen extracts, including soy foods and red clover, appear to have at best only minimal effect on menopausal symptoms but have positive health effects on plasma lipid concentrations and may reduce heart disease. St. John's wort has been shown to improve mild to moderate depression in the general population and appears to show efficacy for mood disorders related to the menopausal transition. Other commonly used botanicals have limited evidence to demonstrate safety and efficacy for relief of symptoms related to menopause.

Diet↗

PubMed2006

Roles for the calcium sensing receptor in primary and metastatic cancer.

AIM: To review the role of the calcium sensing receptor (CASR) in colorectal, breast and parathyroid cancers and related cell lines, and to discuss the effects of CASR in the setting of bone metastases from breast cancer. METHODS: We performed a literature search of the PubMed database of the National Library of Medicine (NLM) to identify articles concerning the CASR's involvement in different cancers. Further relevant papers were obtained from the references of those identified in the original search. RESULTS: Loss of CASR expression is understood to be associated with abnormal differentiation and progression of colorectal carcinoma. It is expressed in both normal and malignant breast tissues and has been implicated in the vicious cycle of bone metastases through its interactions with the parathyroid hormone related peptide (PTHrP). In parathyroid tissue, CASR expression has been linked to proliferation of both parathyroid adenomas and carcinomas. CONCLUSION: Apart from its role in calcium homeostasis, the CASR has many diverse functions in a variety of tissue types throughout the body, and is involved in various signalling pathways relating to cell proliferation and differentiation. CASR has been shown to be involved in the progression and spread of a variety of cancers such as colorectal, breast and parathyroid, and is likely to be the focus of much research to further elucidate its precise role.

Bone Neoplasms↗

PubMed1997

Six novel mutations in the emerin gene causing X-linked Emery-Dreifuss muscular dystrophy.

Mutations in the emerin gene, also referred to as the STA- or EMD-gene, have been found to be the cause of X-linked Emery-Dreifuss muscular dystrophy (EMD). For the present study an optimized set of primers was designed to amplify and sequence each of the six emerin gene exons, including the intron/exon boundaries. All emerin gene exons of 30 unrelated EMD patients have been screened by heteroduplex analysis. Aberrant patterns of single exons were found in seven patients. Direct sequencing of the respective exons revealed six novel mutations distributed in the promotor region and exons 3-6 (delta nt -19 to -40; delta AG nt 620-621; ins A nt 895; delta AT nt 908-909; C-->A nt 1420; ins TA nt 1570). By this study, the first mutations in the promotor region and in exon 5 have been identified. Each of the 25 mutations that have been described so far, including those from the present study, abolishes the synthesis of functional emerin. The mutations were submitted to the EMD Mutation database (http://www.path.cam.ac.uk/emd).

Base Sequence↗

PubMed2004

A physical reference state unifies the structure-derived potential of mean force for protein folding and binding.

Extracting knowledge-based statistical potential from known structures of proteins is proved to be a simple, effective method to obtain an approximate free-energy function. However, the different compositions of amino acid residues at the core, the surface, and the binding interface of proteins prohibited the establishment of a unified statistical potential for folding and binding despite the fact that the physical basis of the interaction (water-mediated interaction between amino acids) is the same. Recently, a physical state of ideal gas, rather than a statistically averaged state, has been used as the reference state for extracting the net interaction energy between amino acid residues of monomeric proteins. Here, we find that this monomer-based potential is more accurate than an existing all-atom knowledge-based potential trained with interfacial structures of dimers in distinguishing native complex structures from docking decoys (100% success rate vs. 52% in 21 dimer/trimer decoy sets). It is also more accurate than a recently developed semiphysical empirical free-energy functional enhanced by an orientation-dependent hydrogen-bonding potential in distinguishing native state from Rosetta docking decoys (94% success rate vs. 74% in 31 antibody-antigen and other complexes based on Z score). In addition, the monomer potential achieved a 93% success rate in distinguishing true dimeric interfaces from artificial crystal interfaces. More importantly, without additional parameters, the potential provides an accurate prediction of binding free energy of protein-peptide and protein-protein complexes (a correlation coefficient of 0.87 and a root-mean-square deviation of 1.76 kcal/mol with 69 experimental data points). This work marks a significant step toward a unified knowledge-based potential that quantitatively captures the common physical principle underlying folding and binding. A Web server for academic users, established for the prediction of binding free energy and the energy evaluation of the protein-protein complexes, may be found at http://theory.med.buffalo.edu.

Antigen-Antibody Complex↗

PubMed2002

Identification of proteins from two-dimensional polyacrylamide gels using a novel acid-labile surfactant.

Protein identification by peptide mass mapping usually involves digestion of gel-separated proteins with trypsin, followed by mass measurement of the resulting peptides by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Positive identification requires measurement of enough peptide masses to obtain a definitive match with sequence information recorded in protein or DNA sequence databases. However, competitive binding and ionization of residual surfactant introduced during polyacrylamide gel electrophoresis (PAGE) can inhibit solid-phase extraction and MS analysis of tryptic peptides. We have evaluated a novel, acid-labile surfactant (ALS) as an alternative to sodium dodecylsulfate (SDS) for two-dimensional (2-D) PAGE separation and MALDI-MS mapping of proteins. ALS was substituted for SDS at the same concentration in buffers and gels used for 2-D PAGE. Manual and automated procedures for spot cutting and in-gel digestion were used to process Coomassie stained proteins for MS analysis. Results indicate that substituting ALS for SDS during PAGE can significantly increase the number of peptides detected by MALDI-MS, especially for proteins of relatively low abundance. This effect is attributed to decomposition of ALS under acidic conditions during gel staining, destaining, peptide extraction and MS sample preparation. Automated excision and digestion procedures reduce contamination by keratin and other impurities, further enhancing MS identification of gel separated proteins.

Alkanesulfonates↗

PubMedDate not supplied

Neighborhood behavior of in silico structural spaces with respect to in vitro activity spaces-a novel understanding of the molecular similarity principle in the context of multiple receptor binding profiles.

As a consequence of recent advances in the field of High Throughput Screening, the systematic testing ("in vitro profiling") of compounds against a panel of targets covering different therapeutic areas is nowadays used to generate relevant information with respect to the in vivo behavior of drug candidates. However, the development of chemoinformatics tools required for the exploitation of such data is yet in an incipient phase. In this paper, a formalism for the analysis of activity profile vectors (describing the experimental responses of compounds in each of the considered activity tests) is introduced and applied at the study of Neighborhood Behavior (NB; the hypothesis that structurally similar compounds display similar biological properties) of molecular similarity metrics. The experimental activity profiles define an Activity Space in which more than 500 drugs and reference compounds are positioned, their coordinates being inhibitory propensities in the included tests and unambiguously characterizing a molecule in terms of its receptor binding properties. While previous studies of Neighborhood Behavior had to rely on a loose classification of compounds in terms of the therapeutic areas they were designed for, here the NB of a calculated "in silico" similarity metric has been redefined as a relationships between intermolecular dissimilarity scores in the "structural" and "activity" spaces, respectively, and expressed in terms of two quantitative criteria: "consistency" (the propensity of the metric to selectively rank activity-related compound pairs among the structurally most similar pairs) and "completeness" (monitoring the retrieval rate of activity-related compound pairs among the best ranked pairs of structural neighbors). These criteria were used to calibrate and validate a similarity metric based on Fuzzy Bipolar Pharmacophore Fingerprints.

Algorithms↗

PubMed2001

Simultaneous modelling of metabolic, genetic and product-interaction networks.

The creation of cell models from annotated genome information, as well as additional data from other databases, requires both a format and medium for its distribution. Standards are described for the representation of the data in the form of Document Type Definitions (DTDs) for XML files. Separate DTDs are detailed for genetic, metabolic and gene product-interaction networks, which can be used to hold information on individual subsystems, or which may be combined to create a whole cell DTD. In the execution of this work, a fifth DTD was also created for a metabolite thesaurus, which allows incorporation of metabolite synonyms and generic nomenclature data into the models. A gene-regulation classification scheme was also created, to facilitate incorporation of gene regulatory information in an efficient manner. The work is described with particular reference to the metabolic network of Escherichia coli, which contains 808 individual enzymes. The assignment of confidence levels to these data, through the use of Gene Ontology evidence codes, is highlighted. In silico investigations may now be performed using the mathematical simulation workbench, DBsolve, which incorporates the facility to introduce data directly from XML.

Computational Biology↗

PubMed2006

Characterization of plasma proteome in biliary atresia.

BACKGROUND: Biliary atresia (BA) is a disorder during infancy with unknown etiology in which progression frequently leads to liver cirrhosis. Plasma proteome is characterized in this study. METHODS: Twelve paired plasma samples from 6 children with BA who received surgical correction at early stage and then liver transplantation at late stage of liver cirrhosis were studied. Plasma samples from 2 subjects without liver disorder were used as normal reference for 2-dimensional gel electrophoresis and for identification of protein spots by mass spectrometric analysis. Plasma samples from another 3 normal subjects (with a total of 5) were used for nephelometric quantification of immunoglobulin kappa light chain in comparison with patients' samples. RESULTS: Among the protein spots detected, ranging from 6 to 200 kDa mass with pIs of 3-10, significant up-regulation of immunoglobulin kappa light chain was found at the late stage of BA, which was subsequently confirmed by nephelometric analysis. Conversely, significant decrease of apolipoprotein (Apo) A-I and C-II, haptoglobin alpha2 and beta chain, and transthyretin were detected during the progression of BA. CONCLUSIONS: Increased immunoglobulin kappa light chain detected in late-stage BA characterizes adverse immune modulation in this disorder. Decreased apolipoproteins, haptoglobin and transthyretin levels might be potential markers of progressive liver injury, fibrosis and defective lipid metabolism in BA.

Biliary Atresia↗

PubMed2006

Deriving pathway maps from automated text analysis using a grammar-based approach.

We demonstrate how automated text analysis can be used to support the large-scale analysis of metabolic and regulatory pathways by deriving pathway maps from textual descriptions found in the scientific literature. The main assumption is that correct syntactic analysis combined with domain-specific heuristics provides a good basis for relation extraction. Our method uses an algorithm that searches through the syntactic trees produced by a parser based on a Referent Grammar formalism, identifies relations mentioned in the sentence, and classifies them with respect to their semantic class and epistemic status (facts, counterfactuals, hypotheses). The semantic categories used in the classification are based on the relation set used in KEGG (Kyoto Encyclopedia of Genes and Genomes), so that pathway maps using KEGG notation can be automatically generated. We present the current version of the relation extraction algorithm and an evaluation based on a corpus of abstracts obtained from PubMed. The results indicate that the method is able to combine a reasonable coverage with high accuracy. We found that 61% of all sentences were parsed, and 97% of the parse trees were judged to be correct. The extraction algorithm was tested on a sample of 300 parse trees and was found to produce correct extractions in 90.5% of the cases.

Abstracting and Indexing↗

PubMed1992

Quantile distributions of amino acid usage in protein classes.

A comparative study of the compositional properties of various protein sets from both cellular and viral organisms is presented. Invariants and contrasts of amino acid usages have been discerned for different protein function classes and for different species using robust statistical methods based on quantile distributions and stochastic ordering relationships. In addition, a quantitative criterion to assess amino acid compositional extremes relative to a reference protein set is proposed and applied. Invariants of amino acid usage relate mainly to the central range of quantile distributions, whereas contrasts occur mainly in the tails of the distributions, especially contrasts between eukaryote and prokaryote species. Influences from genomic constraint are evident, for example, in the arginine:lysine ratios and the usage frequencies of residues encoded by G + C-rich versus A + T-rich codon types. The structurally similar amino acids, glutamate versus aspartate and phenylalanine versus tyrosine, show stochastic dominance relationships for most species protein sets favoring glutamate and phenylalanine respectively. The quantile distribution of hydrophobic amino acid usages in prokaryote data dominates the corresponding quantile distribution in human data. In contrast, glutamate, cysteine, proline and serine usages in human proteins dominate the corresponding quantile distributions in Escherichia coli. E. coli dominates human in the use of basic residues, but no dominance ordering applies to acidic residues. The discussion centers on commonalities and anomalies of the amino acid compositional spectrum in relation to species, function, cellular localization, biochemical and steric attributes, complexity of the amino acid biosynthetic pathway, amino acid relative abundances and founder effects.

Amino Acids↗

PubMed2002

Shannon information theoretic computation of synonymous codon usage biases in coding regions of human and mouse genomes.

Exonic GC of human mRNA reference sequences (RefSeqs), as well as A, C, G, and T in codon position 3 are linearly correlated with genomic GC. These observations utilize information from the completed human genome sequence and a large, high-quality set of human and mouse coding sequences, and are in accord with similar determinations published by others. A Shannon Information Theoretic measure of bias in synonymous codon usage was developed. When applied to either human or mouse RefSeqs, this measure is nonlinearly correlated with genomic, exonic, and third codon position A, C, G, and T. Information values between orthologous mouse and human RefSeqs are linearly correlated: mouse = 0.092 + 0.55 human. Mouse genes were consistently placed in genomic regions whose GC content was closer to 50% than was the GC content of the human ortholog. Since the (nonlinear) information versus percent GC curve has a minimum at 50% GC and monotonically increases with increasing distance from 50% GC, this phenomenon directly results in the low slope of 0.55. This appears to be a manifestation of an evolutionary strategy for placement of genes in regions of the genome with a GC content that relates synonymous codon bias and protein folding.

Animals↗

PubMed2000

Association between hematocrit level and mortality in hemodialysis patients. Case study of the anemic patient.

A large, 4-year, retrospective study of the HCFA end-stage renal disease (ESRD) claims database, Parts A and B, was conducted to determine the association between hematocrit (Hct) level and survival in patients on hemodialysis. Patients who survived the last 6 months of each year and had at least 4 Epoetin alfa claims qualified for the study. Cohort entry years were 1990 through 1993, with the relative risk (RR) of mortality evaluated during the following year. Patients were stratified into four groups on the basis of mean Hct levels in the 6-month entry period: < 27%, 27% to < 30%, 30% to < 33%, and 33% to 36%. Using the 30% to < 33% Hct group as reference (relative risk (RR) = 1), patients whose mean 6-month Hct was in the 33% to 36% range were associated with significantly lower RR of mortality, while patients whose mean 6-month Hct was below 30% were associated with significantly higher RR of mortality. This epidemiologic study highlighted an important association between higher hematocrits in hemodialysis patients and lower RR of mortal.

Anemia, Iron-Deficiency↗

PubMed2004

Distinct protein interfaces in transmembrane domains suggest an in vivo folding model.

Given the known high-resolution structures of alpha-helical transmembrane domains, we show that there are statistically distinct classes of transmembrane interfaces which relate to the folding and oligomerization of transmembrane domains. Distinct types of interfaces have been categorized and refer to those between: the same polypeptide chain, different polypeptide chains, helices that are sequential neighbors, and those that are nonsequential. These different interfaces may reflect different phases in the mechanism of transmembrane domain folding and are consistent with the current experimental evidence pertaining to the folding and oligomerization of transmembrane domains. The classes of helix-helix interfaces have been identified in terms of the numbers and different types of pairwise amino acid interactions. The specific measures used are interaction entropy, the information content of interacting partners compared to a random set of contacts, the amino acid composition of the classes and the abundances of specific amino acid pairs in close contact. Knowledge of the clear differences in the types of helix-helix contacts helps with the derivation of knowledge-based constraints which until now have focused on only the interiors of transmembrane domains as compared to the exterior. Taken together, an in vivo model for membrane protein folding is presented, which is distinct from the familiar two-stage model. The model takes into account the different interfaces of membrane helices defined herein, and the available data regarding folding in the translocation channel.

Databases, Protein↗

PubMed2006

Natalizumab for induction of remission in Crohn's disease.

BACKGROUND: The pathogenesis of Crohn's disease involves migration of leukocytes into gut tissue and subsequent inflammation. Natalizumab (Tysabri, Elan Pharmaceuticals and Biogen Idec) a recombinant humanized IgG4 monoclonal antibody that blocks adhesion and subsequent migration of leukocytes into the gut by binding the alpha4 integrin is a member of a new class of molecules known as selective adhesion molecule (SAM) inhibitors. The results of animal studies suggest that alpha4 integrin blockade could be a useful therapy for inflammatory bowel disease. The results of randomized controlled trials suggest that natalizumab may be an effective therapy for active Crohn's disease. This systematic review summarizes the current evidence on the use of natalizumab for the induction of remission in Crohn's disease. OBJECTIVES: To determine the efficacy and safety of natalizumab for induction of remission in Crohn's disease. SEARCH STRATEGY: A computer assisted search of the Cochrane Central Register of Controlled Trials, the Cochrane Inflammatory Bowel Disease and Functional Bowel Disorders Review Group Specialized Trials Register, MEDLINE and EMBASE was performed to identify relevant publications between 1966 and June 2005. The medical subject heading (MeSH) terms "Crohn disease" or "inflammatory bowel disease", "Natalizumab" or "Antegren" or "Tysabri" and "Antibodies, Monoclonal" were used to perform key word searches of each database. Manual searches of reference lists from potentially relevant papers were performed in order to identify additional studies that may have been missed using the computer-assisted search strategy. Abstracts from major gastroenterological meetings were searched to identify research submitted in abstract form only. Personal contacts, leaders in the field, and the manufacturers were contacted to identify other studies which may not be published. SELECTION CRITERIA: We included only randomized controlled trials comparing natalizumab to a placebo or control therapy for the induction of remission in Crohn's disease. DATA COLLECTION AND ANALYSIS: Data were analyzed using Review Manager (RevMan 4.2.8). All data were analyzed on an intention-to-treat basis. For pooled data, summary test statistics were derived using the relative risk and 95% confidence intervals. Fixed and random effects models were used where appropriate. The definitions of treatment success, remission and clinical improvement were set by the authors of each paper, and the data were combined for analysis only if these definitions were sufficiently similar. MAIN RESULTS: Pooled data from the three included studies suggest that natalizumab (3 to 4 mg/kg) may be effective for induction of clinical response and remission in patients with moderately to severely active Crohn's disease. This benefit is statistically significant for one, two and three infusion treatments. There was a trend toward increased benefit with additional infusions of natalizumab. Natalizumab appears to provide greater benefit for patient subgroups characterized by objective confirmation of active inflammation or chronically active disease despite conventional therapies. These subgroup analyses demonstrated significantly greater clinical response and remission rates for natalizumab compared with placebo in patients with elevated C-reactive protein levels, active disease despite the use of immunosuppressants, or prior anti-tumor necrosis factor therapy. These benefits were apparent for both short term (one infusion) and longer term treatment (two or three infusions). Natalizumab was generally well tolerated and the safety profile observed in the three included studies was similar. Adverse events occurred infrequently and were experienced by a similar proportion of natalizumab and placebo treated patients. There were no statistically significant differences between natalizumab and placebo treated patients in the proportions of patients who withdrew due to adverse events or those who experienced serious adverse events. The included trials lacked adequate power to detect serious adverse events that occur infrequently. Recently, two patients with multiple sclerosis treated with natalizumab in combination with interferon beta-1a and one patient with Crohn's disease treated with natalizumab in combination with azathioprine developed progressive multifocal leukoencephalopathy (PML) resulting in two patient deaths. As a result all dosing in clinical trials and commercial use of natalizumab has been suspended. A retrospective investigation was conducted to assess the risk of PML in natalizumab treated patients and no new cases were identified. AUTHORS' CONCLUSIONS: Pooled data and the results of an ongoing study suggest that natalizumab may be effective for induction of clinical response and remission in patients with moderately to severely active Crohn's disease. The clinical benefit of induction therapy with natalizumab in Crohn's disease should be weighed against the potential risk of serious adverse events. Currently natalizumab is not available on the market for routine clinical use as a consequence of the unexpected association with PML. However, preliminary data from the retrospective investigation of adverse events associated with natalizumab suggest that it may be possible to identify patients at risk for PML by testing for the appearance of JC virus in plasma.

Antibodies, Monoclonal↗

PubMed2005

A compendium of Caenorhabditis elegans regulatory transcription factors: a resource for mapping transcription regulatory networks.

BACKGROUND: Transcription regulatory networks are composed of interactions between transcription factors and their target genes. Whereas unicellular networks have been studied extensively, metazoan transcription regulatory networks remain largely unexplored. Caenorhabditis elegans provides a powerful model to study such metazoan networks because its genome is completely sequenced and many functional genomic tools are available. While C. elegans gene predictions have undergone continuous refinement, this is not true for the annotation of functional transcription factors. The comprehensive identification of transcription factors is essential for the systematic mapping of transcription regulatory networks because it enables the creation of physical transcription factor resources that can be used in assays to map interactions between transcription factors and their target genes. RESULTS: By computational searches and extensive manual curation, we have identified a compendium of 934 transcription factor genes (referred to as wTF2.0). We find that manual curation drastically reduces the number of both false positive and false negative transcription factor predictions. We discuss how transcription factor splice variants and dimer formation may affect the total number of functional transcription factors. In contrast to mouse transcription factor genes, we find that C. elegans transcription factor genes do not undergo significantly more splicing than other genes. This difference may contribute to differences in organism complexity. We identify candidate redundant worm transcription factor genes and orthologous worm and human transcription factor pairs. Finally, we discuss how wTF2.0 can be used together with physical transcription factor clone resources to facilitate the systematic mapping of C. elegans transcription regulatory networks. CONCLUSION: wTF2.0 provides a starting point to decipher the transcription regulatory networks that control metazoan development and function.

Animals↗

PubMed2006

Atherogenic lipid profiles in rheumatoid arthritis.

AIMS: Rheumatoid arthritis is associated with an excess mortality from cardiovascular disease, and this may be related to an atherogenic lipid profile. We set out to identify whether there was a correlation between disease activity and levels of different lipid fractions in a stable population of patients with rheumatoid arthritis on disease-modifying therapy. METHODS: Patients with rheumatoid arthritis were selected from our database and requested to have inflammatory markers and a fasting lipid profile taken at their next visit for monitoring of their disease modifying therapy. RESULTS: 204 patients were recruited for the study. A statistically significant relationship exists between reduced HDL and elevated CRP (p=0.01) and ESR (p=0.041). Elevated ESR, but not elevated CRP, was associated with raised LDL cholesterol (p=0.014). Fourteen patients (6.8%) were receiving statin therapy and 71 (34.8%) were taking prednisone. Use of prednisone, independent of dose, was associated with elevated triglyceride levels (p=0.041). CONCLUSIONS: This study supports previous work showing that rheumatoid arthritis is associated with an adverse lipid profile. While good disease control is clearly important, we should not neglect management of traditional cardiovascular risk factors.

Adult↗

PubMed2005

A 18F-MPPF PET normative database of 5-HT1A receptor binding in men and women over aging.

UNLABELLED: Neurotransmission imaging studies require normative data for the statistical assessment of neurophysiologic dysfunctions. 2'-Methoxyphenyl-(N-2'-pyridinyl)-p-18F-fluoro-benzamidoethylpiperazine (18F-MPPF) is a specific serotonin 5-HT1A antagonist PET tracer recently characterized, modeled, and used for clinical research to explore abnormalities in the serotoninergic system. Our study reports, to our knowledge, the first large normative imaging database of 18F-MPPF binding potential (BP) over aging, for both males and females. METHODS: Fifty-three healthy volunteers (27 females, 26 males; age, 20-70 y) were selected to undergo structural MRI and single-injection 18F-MPPF multiframe dynamic PET. 18F-MPPF BP values were computed using a nonlinear modeling method with tissue reference. The statistical assessment of the effect of age and sex was performed both at the anatomic structure level, using regions of interest drawn manually on individual MR images, and at the voxel level, using normalized BP parametric images in different statistical parametric mapping designs. RESULTS: A negative linear correlation between age and 18F-MPPF binding (3.6% decrease by decade) was found in females but not in males and involved most of the limbic and paralimbic regions; on the other hand, males in their 30s showed decreased binding in most cerebral regions. CONCLUSION: A comparison of males and females revealed higher BP values independent of age in females in the right hemisphere and a different evolution of BP over aging. These results confirm the necessity of a database for further statistical analysis in individuals or groups with pathology.

Adult↗

PubMed1993

Linking yeast genetics to mammalian genomes: identification and mapping of the human homolog of CDC27 via the expressed sequence tag (EST) data base.

We describe a strategy for quickly identifying and positionally mapping human homologs of yeast genes to cross-reference the biological and genetic information known about yeast genes to mammalian chromosomal maps. Optimized computer search methods have been developed to scan the rapidly expanding expressed sequence tag (EST) data base to find human open reading frames related to yeast protein sequence queries. These methods take advantage of the newly developed BLOSUM scoring matrices and the query masking function SEG. The corresponding human cDNA is then used to obtain a high-resolution map position on human and mouse chromosomes, providing the links between yeast genetic analysis and mapped mammalian loci. By using these methods, a human homolog of Saccharomyces cerevisiae CDC27 has been identified and mapped to human chromosome 17 and mouse chromosome 11 between the Pkca and Erbb-2 genes. Human CDC27 encodes an 823-aa protein with global similarity to its fungal homologs CDC27, nuc2+, and BimA. Comprehensive cross-referencing of genes and mutant phenotypes described in humans, mice, and yeast should accelerate the study of normal eukaryotic biology and human disease states.

Amino Acid Sequence↗