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PubMed1977

Dual origin of highly social behavior among bees.

A study of behavior and structure indicates that highly eusocial behavior arose twice in the bees--i.e., in the stingless bees (Meliponinae) and in the honeybees (Apinae). Morphological features demonstrate the distinctiveness of these two groups and the relationship of the latter to bumblebees (Bombini) and orchid bees (Euglossin). The social behaviors of the stingless bees and honeybees, while more or less equally elaborate, are so different as to support their independent origins. The primitive apids, along with the related Xylocopinae (in the Anthophoridae), appear to have had the potential for parasocial, subsocial, and primitively eusocial behavior and from such forms the two highly eusocial groups arose.

Animals↗
PubMed1994

Investigation of the active site and the conformational stability of nucleoside diphosphate kinase by site-directed mutagenesis.

Nucleoside-diphosphate kinase (EC 2.7.4.6) catalyzes phosphate exchange between nucleoside triphosphates and nucleoside diphosphates. Its 17 kDa subunits are highly conserved throughout evolution in both sequence and tertiary structure. Using site-directed mutagenesis we investigated the function of 8 amino acids (Lys16, Tyr56, Arg92, Thr98, Arg109, Asn119, Ser124, and Glu133) that are totally conserved among all nucleoside diphosphate kinases known to date. The mutant proteins all show decreased specific activity and support roles for these residues in catalysis, substrate binding, or both, as was previously proposed on the basis of the x-ray structure (Moréra, S., Lascu, I., Dumas, C., LeBras, G., Briozzo, P., Véron, M., and Janin, J. (1994) Biochemistry 33, 459-467). Furthermore, residues Lys16, Arg109, and Asn 119 were identified to play important roles in conformational stability or subunit interactions. We show that Lys16 and Asn119 form a rigid structure that is important for enzymatic function and that Arg109, known to interact with the phosphate moiety of the substrate, also plays an important role in subunit association. The dual roles of Lys16, Arg109, and Asn119 in both substrate binding and subunit assembly provide further evidence for a functional coupling between catalytic activity and quaternary structure in nucleoside diphosphate kinase.

Amino Acid Sequence↗
PubMed2006

A two-hit trigger for siRNA biogenesis in plants.

In Arabidopsis, microRNA-directed cleavage can define one end of RNAs that then generate phased siRNAs. However, most miRNA-targeted RNAs do not spawn siRNAs, suggesting the existence of additional determinants within those that do. We find that in moss, phased siRNAs arise from regions flanked by dual miR390 cleavage sites. AtTAS3, an siRNA locus important for development and conserved among higher plants, also has dual miR390 complementary sites. Both sites bind miR390 in vitro and are functionally required in Arabidopsis, but cleavage is undetectable at the 5' site--demonstrating that noncleavable sites can be functional in plants. Phased siRNAs also emanate from the bounded regions of every Arabidopsis gene with two known microRNA/siRNA complementary sites, but only rarely from genes with single sites. Therefore, two "hits,"--often, but not always, two cleavage events--constitute a conserved trigger for siRNA biogenesis, a finding with implications for recognition and silencing of aberrant RNA.

Arabidopsis↗
PubMed1998

Issues in identification and linkage of patient records across an integrated delivery system.

Historically, the health information systems community has viewed linking personal records as a mundane task. The oversimplified view that routine database manipulation can accurately identify multiple records for a single individual is erroneous, an assumption based on a misperception of the quality of the underlying data. Such data have been adversely affected by the evolution of individual facility patient indexes from multiple systems and the results of backload procedures, and the lack of focus on the need for data integrity by users of the automated systems. Much of the random, invalid data we identify on a daily basis is directly associated with the need for system users to place data in the patient record while they face the situation of having no obvious data field in which to place them. Combined with an underlying lack of standards for the collection of personal identification information, this results in pure chaos when reviewing an MPI file containing a million records at the start of a linkage evaluation project. We have documented the considerable effort that must therefore be made in standardizing the MPI files using stringent analytical procedures and applying common edit routines before commencing record linkage. This preprocessing effort must then be supplemented with sophisticated matching procedures that can handle the dual challenge of minimizing false negatives (the failure to identify true linkages) and false positives (the incorrect linking of records that do not represent the same person). The identification of pairs of linked records does not, however, complete an EPI loading. Because it is fairly common for a multiple facility linkage evaluation to identify more than two medical record numbers for the same patient, and the primary goal of an EPI is to assign a unique identifier for the patient which will link that patient's multiple files, it becomes necessary to develop a means of readily associating three or more records for the same patient. One approach we have used with great success is to assign a common, sequential identification number to all linked medical record numbers for the same patient regardless of facility. The assignment of linkage identification numbers is computer-intensive and is generally accomplished with a highly iterative process. Both system memory and hard disk resources are fully tested as the number of good linkages in an overlap evaluation reaches the half-million mark or greater. Because the primary linkage analysis goal is to develop linkages on pairs of records, with confidence levels based on the comparison of information for those two records, thresholds must be set to decide which linkages should be accepted as true without any human evaluation. If the threshold is set too low, the defined linkage groups may incorrectly join the medical record numbers for different persons. But if the threshold is set too high, there will be undesired duplication of persons in the enterprise system. As in the identification of the underlying linkage pairs, the development of a confidence measure greatly facilitates the assignment of the unique identification numbers needed in the EPI implementation.

Algorithms↗
PubMed1989

Dual parameter analysis of myeloma cells by flow cytometry. DNA content of cells containing monotypic cytoplasmic immunoglobulin.

Dual-parameter flow cytometric analysis of monotypic cytoplasmic immunoglobulin (CIg) and DNA content on 15 myeloma marrows allowed S-phase determination of the CIg(+) tumor separately from the CIg(-) hematopoietic cell pool. The median percentage of the CIg(+) cells in S-phase was 2% compared with 5% for the CIg(-) cells. The median survival of patients with more than 2%, and those with 2% or less CIg(+) S-phase cells was 2 months and more than 13 months, respectively, from the time of study. Ploidy analysis identified four patterns of plasma cell DNA content: entirely hyperdiploid, entirely diploid, combined diploid and tetraploid stemlines, and tumors containing diploid and aneuploid CIg(+) cells. A monotypic CIg(+) double stemline myeloma was distinguished from two aneuploid tumors containing admixed normal, diploid polyclonal plasma cells. This technique provides an improved and expedient means for determining the proliferating fractions of myeloma cells and enhances recognition of double stemline tumors and clonal evolution in myeloma.

Cytoplasm↗
PubMed2001

Parent-offspring coadaptation and the dual genetic control of maternal care.

In many animal species, the amount of care provided by parents is determined through a complex interaction of offspring signals and responses by parents to those signals. As predicted by honest signaling theory, we show that in the burrower bug, Sehirus cinctus, maternal provisioning responds to experimental manipulations of offspring condition. Despite this predicted environmental influence, we find evidence from two cross-foster experiments that variation in maternal care also stems from two distinct genetic sources: variation among offspring in their ability to elicit care and variation among parents in their response to offspring signals. Furthermore, as predicted by maternal-offspring coadaptation theory, offspring signaling is negatively genetically correlated with maternal provisioning.

Adaptation, Physiological↗
PubMed1993

[The population history of the Japanese].

This paper introduces a "dual structure model" that explains the population history of the Japanese population including the Okinawa islanders (Ryukyus) and Ainu under a single hypothesis. The model assumes that the first occupants of the Japanese Archipelago came from somewhere in Southeast Asia in the Upper Palaeolithic age and gave rise to the people in the Neolithic Jomon age, or Jomonese; then the second wave of migration from North Asia took place in and after the Aeneolithic Yayoi age; and the populations of both lineages gradually mixed with each other. The "dual structure model" also assumes that the population intermixture is still continuing and the dual structure of the Japanese population is maintained even today. Thus, several regional differences such as those between eastern and western Japan in physical as well as cultural characteristics can be explained by the rates of intermixture that vary from region to region. In general, this model agrees well not only with physical and cultural evidence but also with non-human evidence revealed by man's symbiotic animals such as Japanese dogs and mice. At the same time, the model provides a reasonable way of explanation in regard to affinities and relationships among the Japanese main islanders, Ryukyus and Ainu.

Asian People↗
PubMed2025

Evolutionary Diversification and Functions of the Candidate Male Killing Gene wmk.

Symbiont-mediated male killing (MK) is a mechanism that selectively eliminates male offspring, often by disrupting sex-specific developmental processes. In Drosophila melanogaster, the WO-mediated killing gene wmk from Wolbachia prophage WO transgenically reproduces the MK phenotype, yet how the gene evolves and functions across diverse Wolbachia has not been systematically investigated. We analyzed 32 Wolbachia genomes available in the NCBI database to study wmk homologs across different arthropod hosts, reproductive parasitism functions, and Wolbachia supergroups. First, we report at least five distinct wmk phylogenetic clusters (Types I to V), often organized in multigenic dyads or triads. Second, among MK Wolbachia, there is a significantly higher number of wmk genes and diversity in Lepidoptera strains than in Drosophila strains, which exclusively harbor wmk Types I and III. Third, there are three patterns of wmk sequence and genomic organizational changes in Drosophila MK strains that associate with different evolutionary trajectories underpinning the MK phenotype. Fourth, single and combinatory transgenic expression of Types I and III in D. melanogaster uncovers male-biased lethality associated with Type I; however, dual expression of the Types together elicits a major reduction in offspring number. Fifth, wmk genes have low expression level across D. melanogaster developmental stages relative to the cifA and cifB genes, which could explain why cytoplasmic incompatibility is expressed in this system. These findings establish a complex and phylogenetically informed genetic basis of wmk-induced lethality, highlighting the role of gene copy number and expression, wmk Types, and host background in shaping the phenotype.

Animals↗
PubMed2003

Leucine biosynthesis in fungi: entering metabolism through the back door.

After exploring evolutionary aspects of branched-chain amino acid biosynthesis, the review focuses on the extended leucine biosynthetic pathway as it operates in Saccharomyces cerevisiae. First, the genes and enzymes specific for the leucine pathway are considered: LEU4 and LEU9 (encoding the alpha-isopropylmalate synthase isoenzymes), LEU1 (isopropylmalate isomerase), and LEU2 (beta-isopropylmalate dehydrogenase). Emphasis is given to the unusual distribution of the branched-chain amino acid pathway enzymes between mitochondrial matrix and cytosol, on the newly defined role of Leu5p, and on regulatory mechanisms governing gene expression and enzyme activity, including new evidence for the metabolic importance of the regulation of alpha-isopropylmalate synthase by coenzyme A. Next, structure-function relationships of the transcriptional regulator Leu3p are addressed, defining its dual role as activator and repressor and discussing evidence in support of the self-masking model. Recent data pointing at a more extended Leu3p regulon are discussed. An overview of the layered controls of the extended leucine pathway is provided that includes a description of the newly recognized roles of Ilv5p and Bat1p in maintaining mitochondrial integrity. Finally, branched-chain amino acid biosynthesis and its regulation in other fungi are summarized, the question of leucine as metabolic signal is addressed, and possible directions of future research in this area are outlined.

2-Isopropylmalate Synthase↗
PubMed2005

Diversity and functional plasticity of eukaryotic selenoproteins: identification and characterization of the SelJ family.

Selenoproteins are a diverse group of proteins that contain selenocysteine (Sec), the 21st amino acid. In the genetic code, UGA serves as a termination signal and a Sec codon. This dual role has precluded the automatic annotation of selenoproteins. Recent advances in the computational identification of selenoprotein genes have provided a first glimpse of the size, functions, and phylogenetic diversity of eukaryotic selenoproteomes. Here, we describe the identification of a selenoprotein family named SelJ. In contrast to known selenoproteins, SelJ appears to be restricted to actinopterygian fishes and sea urchin, with Cys homologues only found in cnidarians. SelJ shows significant similarity to the jellyfish J1-crystallins and with them constitutes a distinct subfamily within the large family of ADP-ribosylation enzymes. Consistent with its potential role as a structural crystallin, SelJ has preferential and homogeneous expression in the eye lens in early stages of zebrafish development. A structural role for SelJ would be in contrast to the majority of known selenoenzymes. The unusually highly restricted phylogenetic distribution of SelJ, its specialization, and the comparative analysis of eukaryotic selenoproteomes reveal the diversity and functional plasticity of selenoproteins and point to a mosaic evolution of the use of Sec in proteins.

Adenosine Diphosphate Ribose↗
PubMed1989

The polymorphic Fc gamma receptor II gene maps to human chromosome 1q.

Human receptors for IgG (Fc gamma R) play important roles in the immune response. Expression of the human Fc gamma RII gene may be relevant in immune complex related disorders such as systemic lupus erythematosus and Sjogren's syndrome. We have used spot blot analysis of dual laser-sorted human chromosomes to localize the Fc gamma RII gene to human chromosome 1. Spot blot analysis of sorted derivative chromosomes sublocalized the gene to the chromosome 1 long arm (1q12----q25.1). This subchromosomal localization involved reassigning a reciprocal chromosome translocation breakpoint. We also identified Xmn I and Taq I Fc gamma RII polymorphic restriction sites that arose before the races diverged. These common Xmn I and Taq I polymorphisms are predicted to be informative for segregation analysis with human diseases in 85% of all matings.

Antigens, Differentiation↗
PubMed2001

Primary prevention of glucocorticoid-induced osteoporosis with intravenous pamidronate and calcium: a prospective controlled 1-year study comparing a single infusion, an infusion given once every 3 months, and calcium alone.

The aim of this study was to compare the action of two regimens of intravenous (iv) pamidronate in the primary prevention of glucocorticoid-induced osteoporosis (GC-OP). The primary purpose of the study was to determine whether any differences in bone mineral density (BMD) appeared after 1 year. A secondary endpoint aimed at assessing the remodeling parameters in order to better understand the mechanisms of action of the various regimens. Thirty-two patients, who required first-time, long-term glucocorticoid therapy at a daily dose of at least 10 mg of prednisolone, were studied. Simultaneously with the initiation of their glucocorticoid treatment, patients also were randomly allocated to receive a single iv infusion of 90 mg of pamidronate at the start (group A); a first infusion of 90 mg of pamidronate followed, subsequently, by an iv infusion of 30 mg pamidronate every 3 months (group B); and a daily 800-mg elemental calcium supplement given as calcium carbonate (group C), which also was taken by patients in groups A and B. Patients were matched for starting glucocorticoid doses, sex, menopausal status, and hormonal replacement therapy. Lumbar spine and hip (total and subregions) BMDs were measured at the outset and repeated at 6-month intervals by dual-energy X-ray absorptiometry (DXA; Hologic QDR-2000). Bone turnover was assessed by measurement of total and bone-specific serum alkaline phosphatase activity (B-ALP), serum osteocalcin (OC), and serum C-telopeptide cross-links of type I collagen (CTX). After 1 year, the mean BMD changes for groups A, B, and C were, respectively, 1.7, 2.3, and -4.6% at the lumbar spine; 1.2, 1.2, and -3.1% at the femoral neck; 1.0, 2.6, and -2.2% for the total hip region. No difference was observed between pamidronate regimens but a highly significant difference was observed between both pamidronate regimens and the control group at the lumbar spine (p < 0.001), at the femoral neck (p < 0.01), and for the total hip (p < 0.05). A significant decrease of serum C-telopeptide was observed, after 3 months, in groups A and B (p = 0.029), but a sustained decrease of bone resorption over time was observed only in group B. As far as BMD evolution over 1 year was concerned, iv pamidronate, given either as a single infusion or once every 3 months, effectively achieved primary prevention of GC-OP.

Alkaline Phosphatase↗
PubMed1993

[Evolution of pacing modes in patients with implanted pacemakers. Personal considerations on a case load of 171 patients].

In this study retrospectively analyse pacemaker-implantation activity carried out during the last 5 years at the Laboratory of Electrophysiology, affiliated with the Cattedra di Cardiologia of the University of Naples--II Ateneo. Evolution in pacing modes is considered with regard to the patient age, the underlying pathologies and the technical progress in the field. The study has been performed in our laboratory, which is fit up for electrophysiologic studies and implantation of either temporary or permanent pacemakers. Patients included in this study have been implanted in our laboratory either for urgency or for election. They have been retrospectively divided into two groups (age < 65 yrs, 129 patients, and age < 65 yrs, 42 patients); in addition the patients have been classified according to the pathology leading to the implantation: atrio-ventricular block (second degree or third degree), low frequency fibrillation, sick sinus syndrome and carotid sinus syndrome. 171 patients have been examined, of whom 129 > 65 yrs. and 42 < 65 yrs. As for the pacing indication, 54 were atrio-ventricular block (56.1%), 50 were sick sinus syndrome (31.6%), 20 low frequency fibrillation (11.7%), and 1 was carotid sinus syndrome (0.6%). The ratio between single- and dual-chamber pacemakers has been progressively changing: in 1987 we implanted 33 single-chamber and no dual-chamber pacemaker, compared to 7 single- and 23 dual-chamber pacemaker implanted in the last year. This trend is in good agreement with literature data.

Aged↗
PubMed1989

[Pyoderma gangrenosum and IgA gammopathy. Association with atrophic gastritis].

Pyoderma gangrenosum (PG) is a rare condition remarkable for its association with particular diseases, notably haemopathies and gastrointestinal diseases. As regards haemopathies, the associations most frequently encountered are with myeloid malignancies and monoclonal dysglobulinaemia. The association of PG with mainly inflammatory digestive tract diseases is also classical. The lack of publications concerning gastric atrophy and the dual haematological and gastric pathology which characterizes our case have prompted us to report it. A 60-year-old woman without significant history was admitted for PG on both knees, following vesiculo-bullous lesions. Laboratory examinations detected a normochromic anaemia tending to be macrocytic, a marked inflammatory syndrome and a monoclonal lambda light chain IgA peak at protein immunoelectrophoresis. Bone marrow biopsy, skeletal radiography and a search for Bence-Jones proteinuria were normal or negative. Colonoscopy showed no abnormality, but fibroscopy of the upper digestive tract revealed a severe gastric atrophy en plaques. Serum vitamin B12 level was moderately low, but there was no other sign of pernicious anaemia. After one month treatment with systemic corticosteroids, healing was obtained under replacement vitamin therapy. PG recurred a few months later; serum vitamin B12 level was normal, and the lesions healed after systemic corticosteroid treatment. In non-myelomatous dysglobulinaemia IgA is frequently found and there is no light chain predominance. PG often precedes dysglobulinaemia. Evolution towards a true myeloma seems to be exceptional. In a recent publication, 17 cases of association between PG and myeloma were mentioned, the IgA type being most common. Protein electrophoresis is indispensable in patients with PG. Five cases of congenital hypogammaglobulinaemia have been recorded, including three with IgA deficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

Agammaglobulinemia↗
PubMed2005

Evolutionary approaches to understanding sleep.

A major controversy over REM sleep's role in memory processing may owe to inadequate allowances for the highly conservative nature of evolutionary adaptations. The controversy hinges on whether NREM sleep, alone, retains primitive memory processing capabilities. The selective pressure for primitive sleep, is thought to have been the need to obviate conflicts between enormous neural processing requirements of complex visual analysis and split-second control of movements, on the one hand, and memory processing, on the other. The most efficient memory processing during mammalian and avian sleep appears to be a two-step process: synapses in individual component circuits of events are reinforced primarily by slow brain waves during NREM sleep, with the reinforced components temporally bound by fast waves, and manifested as dreams, during REM sleep. This dual action could account for partitioning of sleep periods into multiple NREM-REM cycles. It is proposed that in the absence of REM sleep, all needed memory processing can be accomplished by NREM sleep, alone, though less efficiently. Many symptoms of fatal familial insomnia are attributed to subnormal nightly reinforcement of brain circuitry because of almost total loss of sleep, and compensatory responses thereto during waking. During this disorder, sensory circuitry seemingly is spared by virtue of its supernormal reinforcement during almost continuous waking. Contrariwise, sparing of an adult's 'higher faculties' in encephalitis lethargica appears to owe to supernormal circuit reinforcement during almost continuous sleep.

Awareness↗
PubMed1985

Dual cutaneous reactions to anti-human IgE; no change in plasma level of the split product complement C3d or effect of heparin.

The possible dependence of the dual cutaneous reaction (DCR) on activation of the complement and coagulation systems was further elucidated. Heterologous whole anti-human IgE was injected intradermally (i.d.) on the volar aspect of the forearms of 17 drug-free healthy volunteers and venous samples for the selected laboratory test collected from the adjacent cubital vein. Plasma level of C3 split products (C3d) did not change significantly 6 h and 96 h after the injection of anti-IgE inducing immediate cutaneous reactions (ICRs) or DCRs as compared with prechallenge values. Conventional heparin, a compound with anti-coagulant and anti-complementary effects, injected i.d. (200 IE) concomitantly with and by s.c. (1000 IE) infiltration of the whealing 15 and 90 min subsequently to anti-IgE challenge produced no significant inhibition of the resulting ICRs or DCRs. The results suggest that the previously reported involvement of the coagulation process is a secondary phenomenon and do not support the concept that activation of the complement system is necessary for the evolution of DCRs.

Adult↗
PubMed2004

Nondisjunction rates of mouse specific chromosomes involved in heterozygous Rb rearrangements measured by chromosome painting of spermatocytes II. I. The effects of the number of trivalents.

Dual-colour FISH painting with alternative fluorescent chromosome-specific probes allowed us to distinguish chromosomes 1, 4, 6 and 14. The purpose was to check whether nondisjunction rates of specific chromosomes involved in heterozygous Robertsonian fusions are independent of the number of trivalents, or an epistatic effect among Rb chromosomes takes place affecting nondisjunction rates. Probes were used on DAPI-stained metaphases of spermatocytes II of laboratory strains of mice with reconstructed karyotypes heterozygous for one, two, three or four Robertsonian metacentrics in an all-acrocentric background. The existence of such epistatic interactions was not verified.

Aneuploidy↗
PubMed2005

Nature of gram-negative rod antibiotic resistance during antibiotic rotation.

PURPOSE: The aim of this study was to characterize the evolution of gram-negative antibiotic resistance during a study of empiric antibiotic rotation. METHODS: We showed previously that quarterly rotation of a single antibiotic class is inferior to cycling two antibiotics per quarter for empiric treatment of gram-negative rod (GNR) infections, as evidenced by increased incidence of antibiotic-resistant GNR (rGNR) infections. Resistance patterns were examined by quantifying GNRs resistant to one or more of the following drug classes: Aminoglycosides, cephalosporins, carbapenems, fluoroquinolones, or piperacillin-tazobactam. For all rGNR isolates, the mean number of antibiotic classes to which an organism was resistant was calculated per quarter, as was the number of rGNR species. RESULTS: Single-antibiotic rotation (SAR) was associated with significant increases in the incidence of piperacillin-tazobactam (p < 0.0005) and cephalosporin (p = 0.003) resistance, reaching nearly 25% and 30% of rGNR isolates respectively, most notably during the quarter of designated cephalosporin use (VI). Multi-drug resistance emerged over time; resistant classes/resistant GNR isolates ranged from 1.2 in the dual-antibiotic rotation (DAR) to 1.9 in the SAR period (p = 0.02). Resistance was evident in an increasing number of unique GNR species. On average, 1.3 species were isolated per month in the DAR period and 3.0/month in the SAR period (p = 0.004), but proportionally, no single GNR species became significantly more resistant across time. Compared to only 5.8% in the DAR period, 29% noncompliance was observed in the SAR, with a six-fold increase in the use of nonscheduled empiric antibiotics due to the presence of an organism resistant to the scheduled rotation drug. CONCLUSIONS: A single-antibiotic rotation is associated with increased incidence and heterogeneity of resistant GNR isolates, as well as increased multiple-drug-class resistance. The attenuation of resistance observed in the single-antibiotic rotation may reflect the effect of unintended antibiotic heterogeneity driven by increasing resistance to the antibiotic class recommended for use each quarter. This suggests that reliance on a single antibiotic class for empiric treatment of GNR infection exerts sufficient pressure within the environment to encourage the development of diversified resistance, as well as cross-resistance over antibiotic classes, thus narrowing the availability of effective antibiotic treatment.

Anti-Bacterial Agents↗