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PubMed1985

Analysis of mosquito control agency public education programs in the United States.

Mosquito control is an important element of public health maintenance in the United States. Mosquito control agencies in this country have embraced the concept of Integrated Mosquito Control for the last decade or more. This concept ideally integrates the elements of chemical control, biological control and physical control, augmented by a planned public education program, into the total operational mosquito control program. Public education is the activity of routinely providing mosquito control information to the public-at-large, so that breeding sources on private properties can be reduced or eliminated. Public education appears to be highly regarded by the vast majority of American mosquito control workers. Despite this, it is not used as extensively by most mosquito control agencies as the more traditional chemical, biological and physical control methods. This study indicates that only a very small portion of the budgets of this country's mosquito control agencies is allocated to public education activities.

Health Education↗
PubMed2006

Mouse homologue of skin-specific retroviral-like aspartic protease involved in wrinkle formation.

Retroviral proteases are encoded in the retroviral genome and are responsible for maturation and assembly of infectious virus particles. A number of retroviral protease sequences with retroviral elements are integrated in every eukaryotic genome as endogenous retroviruses. Recently, retroviral-like aspartic proteases that were not embedded within endogenous retroviral elements were identified throughout the eukaryotic and prokaryotic genomes. However, the physiological role of this novel protease family, especially in mammals, is not known. During the high throughput in situ hybridization screening of mouse epidermis, as a granular layer-expressing clone, we identified a mouse homologue of SASPase (Skin ASpartic Protease), a recently identified retroviral-like aspartic protease. We detected and purified the endogenous 32-kDa (mSASP32) and 15-kDa (mSASP15) forms of mSASP from mouse stratum corneum extracts and determined their amino acid sequences. Next, we bacterially produced recombinant mSASP15 via autoprocessing of GST-mSASP32. Purified recombinant mSASP15 cleaved a quenched fluorogenic peptide substrate, designed from the autoprocessing site for mSASP32 maximally at pH 5.77, which is close to the pH of the epidermal surface. Finally, we generated mSASP-deficient mice that at 5 weeks of age showed fine wrinkles that ran parallel on the lateral trunk without apparent epidermal differentiation defects. These results indicate that the retroviral-like aspartic protease, SASPase, is involved in prevention of fine wrinkle formation via activation in a weakly acidic stratum corneum environment. This study provides the first evidence that retroviral-like aspartic protease is functionally important in mammalian tissue organization.

Amino Acid Sequence↗
PubMed1989

Vital links. Hospital's geriatric program integrates the spectrum of care.

In July 1988 St. Mary Medical Center (SMMC), Long Beach, CA, established Older Adult Services (OAS) to help the elderly of the community. At the time, SMMC was already providing a number of services for the elderly, but OAS enables it to provide a continuum of care. In addition, the medical staff committee developing the geriatric program recommended establishing a geriatric assessment team headed by a fellowship-trained geriatrician, having that geriatrician serve as medical director of the inpatient skilled nursing facility (SNF), having the geriatric team develop treatment protocols in various aspects of care, and extending OAS within the community. The categories of service within the continuum are extended care, acute care, ambulatory care, home care, outreach, wellness, and housing. SMMC does not directly provide all services; rather, through integrating mechanisms, it uses community-based services or services provided by other institutions to meet some patient needs. A key element to integrating the continuum is the involvement of OAS in the SNF. The SNF medical director can bring the expertise of the geriatric assessment team to a wide sphere of the medical community. This sphere of influence quickly spreads to the hospital's entire medical community. Through direct participation in utilization review and quality assurance in the SNF, the OAS director can influence the quality of care.

Aged↗
PubMed1998

Complex structure of knob DNA on maize chromosome 9. Retrotransposon invasion into heterochromatin.

The recovery of maize (Zea mays L.) chromosome addition lines of oat (Avena sativa L.) from oat x maize crosses enables us to analyze the structure and composition of specific regions, such as knobs, of individual maize chromosomes. A DNA hybridization blot panel of eight individual maize chromosome addition lines revealed that 180-bp repeats found in knobs are present in each of these maize chromosomes, but the copy number varies from approximately 100 to 25, 000. Cosmid clones with knob DNA segments were isolated from a genomic library of an oat-maize chromosome 9 addition line with the help of the 180-bp knob-associated repeated DNA sequence used as a probe. Cloned knob DNA segments revealed a complex organization in which blocks of tandemly arranged 180-bp repeating units are interrupted by insertions of other repeated DNA sequences, mostly represented by individual full size copies of retrotransposable elements. There is an obvious preference for the integration of retrotransposable elements into certain sites (hot spots) of the 180-bp repeat. Sequence microheterogeneity including point mutations and duplications was found in copies of 180-bp repeats. The 180-bp repeats within an array all had the same polarity. Restriction maps constructed for 23 cloned knob DNA fragments revealed the positions of polymorphic sites and sites of integration of insertion elements. Discovery of the interspersion of retrotransposable elements among blocks of tandem repeats in maize and some other organisms suggests that this pattern may be basic to heterochromatin organization for eukaryotes.

Avena↗
PubMed2003

Sustainable correction of junctional epidermolysis bullosa via transposon-mediated nonviral gene transfer.

Sustainable correction of severe human genetic disorders of self-renewing tissues, such as the blistering skin disease junctional epidermolysis bullosa (JEB), is facilitated by stable genomic integration of therapeutic genes into somatic tissue stem cells. While integrating viral vectors can achieve this, they suffer from logistical and biosafety concerns. To circumvent these limitations, we used the Sleeping Beauty transposable element to integrate the LAMB3 cDNA into genomes of epidermal holoclones from six unrelated JEB patients. These cells regenerate human JEB skin that is normalized at the level of laminin 5 protein expression, hemidesmosome formation and blistering. Transposon-mediated gene delivery therefore affords an opportunity for stable gene delivery in JEB and other human diseases.

Animals↗
PubMed1996

Malignant conversion of chemically transformed normal human cells.

Two structurally unrelated chemicals, aflatoxin B1 and propane sultone, transformed human foreskin cells to a stage of anchorage-independent growth. Isolation from agar and repopulation in monolayer culture of these transformed cells was followed by transfection with a cDNA library, which resulted in cells that exhibited an altered epithelioid morphology. Chemically transformed/nontransfected cells and transfected normal cells did not undergo a significant morphological change. These epithelioid-appearing, transfected cells, when inoculated into nude mice, form progressively growing tumors. The tumors are histopathologically interpreted as carcinomas. All of the first generation tumors in the surrogate hosts exhibited characteristic rates of growth similar to those of transplants of spontaneous human tumors. In the second generation of tumor xenografts, the progressively growing tumors derived from the transfected cells exhibited a more rapid rate of growth. Southern analysis and reverse transcription PCR confirmed that a 1.3-kb genetic element was integrated into the genome and was actively being transcribed. Examination of the metaphase chromosomes in normal human cells revealed that the genetic element responsible for this conversion was located at site 31-32 of the q arm of chromosome 7. The DNA sequence of this 1.3-kb genetic element contains a coding region for 79 amino acids and a long 3'-untranslated region and appears to be identical to CATR1.3 isolated from tumors produced by methyl methanesulfonate-converted, nontransplantable human tumor cells.

Aflatoxin B1↗
PubMed1988

Insertional activation of a promoterless thymidine kinase gene.

A plasmid carrying a promoterless herpes simplex virus thymidine kinase gene was transfected via calcium phosphate precipitation into LM (tk-) mouse fibroblast cells. The transfected gene was efficiently expressed, as the transfected cells grew perfectly well in selective hypoxanthine-aminopterin-thymidine medium, suggesting that the thymidine kinase-coding region became linked to a promoterlike element on integration into the recipient genome. To investigate the structure of the surrogate promoter, we first isolated the integrated gene from a genomic library. The nucleotide sequence of the DNA adjacent to the thymidine kinase-coding sequence was then determined. We found, first, that the integration of the transfected DNA apparently occurred by a blunt end ligation mechanism involving no obvious sequence similarities between integrated and recipient DNA and, second, that the 5'-flanking region included a TATA box, two CCAAT boxes, and a GC box element. However, the TATA box motif and the most proximal CCAAT box appeared to be sufficient for full promoter activity, as determined by the transfection efficiencies of appropriate plasmid constructs. Except for these canonical promoter elements, the surrogate promoter had no obvious similarities to known thymidine kinase gene promoters.

Animals↗
PubMed2006

The genomic distribution of L1 elements: the role of insertion bias and natural selection.

LINE-1 (L1) retrotransposons constitute the most successful family of retroelements in mammals and account for as much as 20% of mammalian DNA. L1 elements can be found in all genomic regions but they are far more abundant in AT-rich, gene-poor, and low-recombining regions of the genome. In addition, the sex chromosomes and some genes seem disproportionately enriched in L1 elements. Insertion bias and selective processes can both account for this biased distribution of L1 elements. L1 elements do not appear to insert randomly in the genome and this insertion bias can at least partially explain the genomic distribution of L1. The contrasted distribution of L1 and Alu elements suggests that postinsertional processes play a major role in shaping L1 distribution. The most likely mechanism is the loss of recently integrated L1 elements that are deleterious (negative selection) either because of disruption of gene function or their ability to mediate ectopic recombination. By comparison, the retention of L1 elements because of some positive effect is limited to a small fraction of the genome. Understanding the respective importance of insertion bias and selection will require a better knowledge of insertion mechanisms and the dynamics of L1 inserts in populations.

Journal Article↗
PubMed1999

Interspersed DNA element restricted to a specific group of telomeres in the dipteran Chironomus pallidivittatus.

Telomeres in the dipteran Chironomus pallidivittatus terminate with 340bp tandem DNA repeats belonging to different subfamilies with characteristic intertelomeric distribution. We have now found, interspersed between such repeats, a composite element of approx. 1400bp present in two similar size variants, with several components of nontelomeric origin. There were about 50 copies of the element, predominantly or exclusively present in a previously defined group of telomeres, characterized by a unique set of telomeric tandem repeat subfamilies. Elements were integrated at irregular distances from each other, and intervening telomeric tandem repeat DNA was variable in composition. Nevertheless, the flanks immediately surrounding the elements were identical for different elements; in other words, there was a site-specific insertion. We suggest that this selective invasion of a small part of the genome by an interspersed, probably rapidly evolving element is best explained by repeated gene conversions.

Animals↗
PubMed2001

Formation of helical hairpins during membrane protein integration into the endoplasmic reticulum membrane. Role of the N and C-terminal flanking regions.

The helical hairpin, two closely spaced transmembrane helices separated by a short turn, is a common structural element in integral membrane proteins. Previous studies on the sequence determinants of helical hairpin formation have focussed on the role of polar and charged residues placed centrally in a long stretch of hydrophobic residues, and have yielded a "propensity scale" for the relative efficiency with which different residues promote the formation of helical hairpins. In this study, we shift our attention to the role of charged residues flanking the hydrophobic stretch. Clusters of charged residues are known to hinder membrane translocation, and thus flanking charged residues may conceivably force a long hydrophobic segment to form a helical hairpin even if there are no or only weakly turn-promoting residues in the hydrophobic stretch. We indeed find that Lys and, more surprisingly, Asp residues strongly affect helical hairpin formation when placed next to a poly-Leu-based transmembrane segment. We also find that a cluster of four consecutive Lys residues can affect the efficiency of helical hairpin formation even when placed approximately 30 residues downstream of the hydrophobic stretch. These observations have interesting implications for the way we picture membrane protein topogenesis within the context of the endoplasmic reticulum (ER) translocon.

Aspartic Acid↗
PubMed2003

Computation of dynamic adsorption with adaptive integral, finite difference, and finite element methods.

Analysis of diffusion-controlled adsorption and surface tension in one-dimensional planar coordinates with a finite diffusion length and a nonlinear isotherm, such as the Langmuir or Frumkin isotherm, requires numerical solution of the governing equations. This paper presents three numerical methods for solving this problem. First, the often-used integral (I) method with the trapezoidal rule approximation is improved by implementing a technique for error estimation and choosing time-step sizes adaptively. Next, an improved finite difference (FD) method and a new finite element (FE) method are developed. Both methods incorporate (a). an algorithm for generating spatially stretched grids and (b). a predictor-corrector method with adaptive time integration. The analytical solution of the problem for a linear dynamic isotherm (Henry isotherm) is used to validate the numerical solutions. Solutions for the Langmuir and Frumkin isotherms obtained using the I, FD, and FE methods are compared with regard to accuracy and efficiency. The results show that to attain the same accuracy, the FE method is the most efficient of the three methods used.

Adsorption↗
PubMed2001

Hermes-mediated germ-line transformation of the Mediterranean fruit fly Ceratitis capitata.

We report the use of the Hermes transposable element for germ-line transformation of the Mediterranean fruit fly, Ceratitis capitata. Hermes was able to genetically transform this insect at an estimated frequency between 0.6 and 1.1%, which is comparable to the transformation frequencies obtained for this species when using other transposable elements. Hermes integrates into the medfly genome by a cut-and-paste mechanism and the sequences integrated into the genome are delimited by the terminal nucleotides of the Hermes inverted terminal repeats. Integration resulted in the generation of 8 bp target site duplications, the sequences of which conformed to the target site duplications generated by hAT element transposition in insects. The Hermes element is one additional genetic tool that can be deployed in manipulating and characterizing the medfly genome.

Animals↗
PubMedDate not supplied

Integrating the therapeutic community and work release for drug-involved offenders. The CREST Program.

As the nation's first therapeutic community (TC) and work release center for drug involved offenders, CREST combines the basic elements of both modalities into an effective agent for behavioral change. This article explores the ways in which these elements are integrated and applied, and the outcome of such treatment as determined by subsequent substance abuse and criminal activity. Clients entering the program from prison progress through several phases of counseling, group interaction, confrontation, and education before they enter the work release phase, where they gain realistic experience and can implement what they learned in the TC concerning living drug free. Follow-up data collected at 6 and 18 months after entry into the program indicate that CREST clients have significantly lower relapse and recidivism rates than a comparable comparison group. CREST has similar effects on relapse and recidivism across sexes, racial/ethnic groups, and different age categories, although length of time in treatment and whether clients graduated do impact outcome variables.

Adolescent↗
PubMed2006

Nanoscale avalanche photodiodes for highly sensitive and spatially resolved photon detection.

Integrating nanophotonics with electronics could enhance and/or enable opportunities in areas ranging from communications and computing to novel diagnostics. Light sources and detectors are important elements for integration, and key progress has been made using semiconducting nanowires and carbon nanotubes to yield electrically driven sources and photoconductor detectors. Detection with photoconductors has relatively poor sensitivity at the nanometre scale, and thus large amplification is required to detect low light levels and ultimately single photons with reasonable response time. Here, we report avalanche multiplication of the photocurrent in nanoscale p-n diodes consisting of crossed silicon-cadmium sulphide nanowires. Electrical transport and optical measurements demonstrate that the nanowire avalanche photodiodes (nanoAPDs) have ultrahigh sensitivity with detection limits of less than 100 photons, and subwavelength spatial resolution of at least 250 nm. Crossed nanowire arrays also show that nanoAPDs are reproducible and can be addressed independently without cross-talk. NanoAPDs and arrays could open new opportunities for ultradense integrated systems, sensing and imaging applications.

Journal Article↗
PubMed2001

The clc element of Pseudomonas sp. strain B13 and other mobile degradative elements employing phage-like integrases.

Genes for metabolic pathways in bacteria that degrade aromatic or aliphatic pollutants have mostly been confined to either plasmid DNAs or to the chromosome. For a few pathways, including classical pathways for chlorocatechol and biphenyl degradation, recent evidence has been obtained for location of the pathway genes on mobile DNA elements which employ phage-like integrases. This enables the DNA elements to integrate into specific sites on the chromosome and yet to excise and transfer to other host bacteria. This mini-review gives an overview of those elements and their relationship to an increasing number of phage-like elements associated with bacterial virulence.

Biodegradation, Environmental↗
PubMed1986

Transposable genetic element found in the 5'-flanking region of the fibroin H-chain gene in a genomic clone from the silkworm Bombyx mori.

A transposable genetic element was found in the 5'-flanking region of the fibroin H-chain gene in one of the genomic clones from the silkworm Bombyx mori. This element, named K-1.4, is about 1 X 4 X 10(3) base-pairs long, contains an open reading frame of only 225 base-pairs and has inverted repeats of 12 base-pairs at both ends. Duplication of three base-pairs seems to have occurred when this element was integrated into the silkworm genome. About 15 copies of K-1.4 are present per haploid genome of various silkworm strains. Genomic loci of some of these elements are different among different strains or even among individual offspring of the same parents. K-1.4 is present also in the genome of Bombyx mandarina. The K-1.4-related sequences are present in some species belonging to the family Saturniidae.

Animals↗
PubMed2001

HERV-K(OLD): ancestor sequences of the human endogenous retrovirus family HERV-K(HML-2).

Sequences homologous to the human endogenous retrovirus (HERV) family HERV-K(HML-2) are present in all Old World primate species. A previous study showed that a central region of the HERV-K(HML-2) gag genes in Hominoidea species displays a 96-bp deletion compared to the gag genes in lower Old World primates. The more ancient HERV-K(HML-2) sequences present in lower Old World primates were apparently not conserved during hominoid evolution, as opposed to the deletion variants. To further clarify the evolutionary origin of the HERV-K(HML-2) family, we screened GenBank with the 96-bp gag-sequence characteristic of lower Old World primates and identified, to date, 10 human sequence entries harboring either full-length or partially deleted proviral structures, probably representing remnants of a more ancient HERV-K(HML-2) variant. The high degree of mutations demonstrates the long-time presence of these HERV-K(OLD) proviruses in the genome. Nevertheless, they still belong to the HML-2 family as deduced from dot matrix and phylogenetic analyses. We estimate, based on the family ages of integrated Alu elements and on long terminal repeat (LTR) divergence data, that the average age of HERV-K(OLD) proviruses is ca. 28 million years, supporting an integration time before the evolutionary split of Hominoidea from lower Old World primates. Analysis of HERV-K(OLD) LTR sequences led to the distinction of two subgroups, both of which cluster with LTRs belonging to an evolutionarily older cluster. Taken together, our data give further insight into the evolutionary history of the HERV-K(HML-2) family during primate evolution.

Amino Acid Sequence↗
PubMed2005

Prophage-like elements in bifidobacteria: insights from genomics, transcription, integration, distribution, and phylogenetic analysis.

So far, there is only fragmentary and unconfirmed information on bacteriophages infecting the genus Bifidobacterium. In this report we analyzed three prophage-like elements that are present in the genomes of Bifidobacterium breve UCC 2003, Bifidobacterium longum NCC 2705, and Bifidobacterium longum DJO10A, designated Bbr-1, Bl-1, and Blj-1, respectively. These prophagelike elements exhibit homology with genes of double-stranded DNA bacteriophages spanning a broad phylogenetic range of host bacteria and are surprisingly closely related to bacteriophages infecting low-G+C bacteria. All three prophage-like elements are integrated in a tRNA(Met) gene, which appears to be reconstructed following phage integration. Analysis of the distribution of this integration site in many bifidobacterial species revealed that the attB sites are well conserved. The Blj-1 prophage is 36.9 kb long and was induced when a B. longum DJO10A culture was exposed to mitomycin C or hydrogen peroxide. The Bbr-1 prophage-like element appears to consist of a noninducible 28.5-kb chimeric DNA fragment composed of a composite mobile element inserted into prophage-like sequences, which do not appear to be widely distributed among B. breve strains. Northern blot analysis of the Bbr-1 prophage-like element showed that large parts of its genome are transcriptionally silent. Interestingly, a gene predicted to encode an extracellular beta-glucosidase carried within the Bbr-1 prophage-like element was shown to be transcribed.

Base Sequence↗