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K Hennessy

Publications and source records attributed to K Hennessy.

At least 19 recordsLinked to original sources
PubMed2006

Self-tuned quantum dot gain in photonic crystal lasers.

We demonstrate that very few (2-4) quantum dots as a gain medium are sufficient to realize a photonic-crystal laser based on a high-quality nanocavity. Photon correlation measurements show a transition from a thermal to a coherent light state proving that lasing action occurs at ultralow thresholds. Observation of lasing is unexpected since the cavity mode is in general not resonant with the discrete quantum dot states and emission at those frequencies is suppressed. In this situation, the quasicontinuous quantum dot states become crucial since they provide an energy-transfer channel into the lasing mode, effectively leading to a self-tuned resonance for the gain medium.

Journal Article↗
PubMed2005

piggyBac internal sequences are necessary for efficient transformation of target genomes.

A previously reported piggyBac minimal sequence cartridge, which is capable of efficient transposition in embryo interplasmid transposition assays, failed to produce transformants at a significant frequency in Drosophila melanogaster compared with full-length or less extensive internal deletion constructs. We have re-examined the importance of these internal domain (ID) sequences for germline transformation using a PCR strategy that effectively adds increasing lengths of ID sequences to each terminus. A series of these piggyBac ID synthetic deletion plasmids containing the 3xP3-ECFP marker gene are compared for germline transformation of D. melanogaster. Our analyses identify a minimal sequence configuration that is sufficient for movement of piggyBac vectored sequences from plasmids into the insect genome. Southern hybridizations confirm the presence of the piggyBac transposon sequences, and insertion site analyses confirm these integrations target TTAA sites. The results verify that ID sequences adjacent to the 5' and 3' terminal repeat domains are crucial for effective germline transformation with piggyBac even though they are not required for excision or interplasmid transposition. Using this information we reconstructed an inverted repeat cartridge, ITR1.1k, and a minimal piggyBac transposon vector, pXL-BacII-ECFP, each of which contains these identified ID sequences in addition to the terminal repeat configuration previously described as essential for mobility. We confirm in independent experiments that these new minimal constructs yield transformation frequencies similar to the control piggyBac vector. Sequencing analyses of our constructs verify the position and the source of a point mutation within the 3' internal repeat sequence of our vectors that has no apparent effect on transformation efficiency.

Animals↗
PubMed2002

Simultaneous flow cytometric analysis of phagocytosis and oxidative burst activity in equine leukocytes.

This paper describes a method for simultaneously measuring phagocytosis and oxidative burst activity in equine peripheral blood leukocytes by flow cytometry. Opsonized propidium iodide-labelled Staphylococcus aureus (PI-Sa) was used to measure the uptake of bacteria by equine phacocytes and the oxidative burst activity by oxidation of dihydrorhodamine 123. The requirements to achieve optimal activity of phagocytosis and oxidative burst are described. The advantage of the simultaneous technique is that it provides both independent and comparative values for phagocytosis and the oxidative burst, for the detection of impaired mechanisms of microbial destruction. Furthermore, the technique allows evaluation of opsonization activity in this context.

Animals↗
PubMed2002

Utility and accuracy of template-directed dye-terminator incorporation with fluorescence-polarization detection for genotyping single nucleotide polymorphisms.

There are little independent data available about how well single nucleotide polymorphism (SNP) genotyping technologies perform in the typical molecular genetics laboratory. We evaluated the utility and accuracy of a widely used technology, template-directed dye-terminator incorporation with fluorescence-polarization detection (FP-TDI), in a sample of 177 SNPs selected solely on the basis of map location. Genotypes were generated without optimization using standard protocols. Overall, 81% of the SNPs we studied generated readable genotypes by FP-TDI. Thirty-two SNPs were genotyped in duplicate by PCR-RFLP orfluorescent dye-terminator sequencing. Out of a total of 631 duplicate genotypes, no true discrepancies were detected. The true error rate has a 95% chance of lying between 0 and 6 out of 1000 genotypes. We also tested for deviations from Hardy-Weinberg Equilibrium in 33 SNPs genotyped in 50 unrelated individuals, and no significant deviations were detected. Our FP-TDI data were readily adaptable to automated genotype calling using our own method of cluster analysis, which assigns a probability score to each genotype call. We conclude that FP-TDI is both efficient and accurate. The method can easily fill the needs of SNP genotyping projects at the scale typically used for regional or candidate-gene association studies.

Fluorescence Polarization↗
PubMed2000

Characterization of peripheral blood and pulmonary leukocyte function in healthy foals.

Studies in infants and foals indicate an age-dependent maturation of peripheral lymphocyte subsets. The age-dependent relationship for maturation of cellular immune responses, such as phagocytosis and lymphocyte responses of the peripheral and pulmonary-derived leukocytes, has not been characterized in foals. Lymphocyte subpopulations, mitogen stimulation response of lymphocytes, lymphokine-activated killing cell activity, phagocytosis and oxidative burst activity, and serum immunoglobulin (Ig) classes G and M concentrations were determined in developing foals. This study illustrates age-dependent changes in immunoglobulin class concentrations, lymphocyte subsets, and EqMHC Class II expression in cells of the peripheral blood and lungs of developing neonatal-to-weanling foals. The increase in peripheral blood and BAL B-lymphocytes and serum immunoglobulins in developing foals suggests expansion of immune cell populations during a time in which environmental pathogen exposure is great. General immune function, mitogenic responses, LAK cell activity, opsonized phagocytosis, and oxidative burst activity of newborns was similar to the adult horse. Total immune-cell numbers, rather than function, seemed to be the limiting factor in the development of the equine neonatal immune system. There was an age-related percent increase in the appearance of pulmonary lymphocytes, but a percent decrease in macrophages. Although development of the respiratory immune system follows changes in the peripheral blood, cellular expansion, activation, and migration may occur at a slower pace, making the respiratory environment susceptible to pathogens prior to optimal immune system maturity.

Aging↗
PubMed1997

The nucleotide sequence of Saccharomyces cerevisiae chromosome V.

Here we report the sequence of 569,202 base pairs of Saccharomyces cerevisiae chromosome V. Analysis of the sequence revealed a centromere, two telomeres and 271 open reading frames (ORFs) plus 13 tRNAs and four small nuclear RNAs. There are two Tyl transposable elements, each of which contains an ORF (included in the count of 271). Of the ORFs, 78 (29%) are new, 81 (30%) have potential homologues in the public databases, and 112 (41%) are previously characterized yeast genes.

Base Sequence↗
PubMed1997

Clinical pathways in home nutrition support.

In home-care settings, physicians with various medical specialties may order home enteral and/or parenteral nutrition support. Clinical pathways may be used to provide a clear, concise, standardized method for ordering and monitoring home nutrition support. The clinical pathways should be appropriate for 80% of the patients placed on the pathways, allowing for a 20% variance, or deviation, from the pathway. In one home-care facility, disease-specific clinical pathways have been used for longer than 1 year for patients with a variety of diseases requiring home nutrition support. To determine the usefulness of the home nutrition support clinical pathways, data obtained from 20 patients were analyzed. Patients were followed up while being treated using home nutrition support clinical pathways designed for oncology (9 patients), human immunodeficiency virus/acquired immunodeficiency syndrome (2 patients), short bowel syndrome (6 patients), and hyperemesis (3 patients) for 191 weeks. Overall, an average variance (deviation from the pathway) of 22% (the number of variances divided by the total weeks of therapy) was observed. The use of the pathways to provide enteral or parenteral nutrition facilitated more cost-effective care by following pathway guidelines for obtaining laboratory values and patient visits. Communication between the home-care staff and the physician was also improved. Clinical pathways can enable standardization of care for patients receiving nutrition support at home.

Critical Pathways↗
PubMed1996

The myeloid-cell-specific c-fes promoter is regulated by Sp1, PU.1, and a novel transcription factor.

The protein product of the c-fps/fes (c-fes) proto-oncogene has been implicated in the normal development of myeloid cells (macrophages and neutrophils). mRNA for c-fes has been detected exclusively in myeloid cells and vascular endothelial cells in adult mammals. Although a 13-kilobase-pair (kb) human c-fes transgene exhibits high levels of expression in mice, the sequences that confer myeloid-cell-specific expression of the human c-fes gene have not been defined. Transient-transfection experiments demonstrated that plasmids containing 446 bp of c-fes 5'-flanking sequences linked to a luciferase reporter gene were active exclusively in myeloid cells. No other DNA element within the 13-kb human c-fes locus contained positive cis-acting elements, with the exception of a weakly active region within the 3'-flanking sequences. DNase I footprinting assays revealed four distinct sites that bind myeloid nuclear proteins (-408 to -386, -293 to -254, -76 to -65, and -34 to +3). However, the first two footprints resided in sequences that were largely dispensable for transient activity. Plasmids containing 151 bp of 5'-flanking sequences confer myeloid-cell-specific gene expression. Electrophoretic mobility shift analyses demonstrated that the 151-bp region contains nuclear protein binding sites for Sp1, PU.1, and/or Elf-1, and a novel factor. This unidentified factor binds immediately 3' of the PU.1/Elf-1 sites and appears to be myeloid cell specific. Mutation of the PU.1/Elf-1 site or the 3' site (FP4-3') within the context of the c-fes promoter resulted in substantially reduced activity in transient transfections. Furthermore, transient-cotransfection assay demonstrated that PU.1 (and not Elf-1) can transactivate the c-fes promoter in nonmyeloid cell lines. We conclude that the human c-fes gene contains a strong myeloid-cell-specific promoter that is regulated by Sp1, PU.1, and a novel transcription factor.

Animals↗
PubMed1994

DNA sequence confidence estimation.

A significant bottleneck in the current DNA sequencing process is the manual editing of trace data generated by automated DNA sequencers. This step is used to correct base calls and to associate to each base call a confidence level. The confidence levels are used in the assembly process to determine overlaps and to resolve discrepancies in determining the consensus sequence. This single step may cost as much as 4 to 8 cents per finished base. We report an approach to automated trace editing using classification trees to detect and exploit context-based patterns in trace peak heights. Local base composition and nearby peak heights account for 80% of the variations in peak heights. Classification algorithms were developed to identify 37% of automated base calls that differ from the consensus sequence. With these algorithms, 12% of the base calls had confidence levels less than 90%.

Algorithms↗
PubMed1993

A dangerous lack of understanding.

In the past, inadequate information on the effects of maternal alcohol consumption on the fetus meant that not enough emphasis was placed on this topic in prenatal and preconceptual teaching. Today, fetal alcohol syndrome is a widely accepted diagnosis in the medical community. Health professionals now stress the importance of abstinence from alcohol during pregnancy, especially during the first trimester. Unfortunately, a surprising number of adults have but a meagre knowledge of the risks. This dangerous lack of understanding represents a failure in health promotion.

Female↗
PubMed1990

Nutrition support nursing: a specialty practice: historical development.

Nutrition Support Nursing as an area of specialization within nursing emerged from the development of new technology that enabled patients to be fed totally by vein and from the realization that this complex, new therapy could not be administered safely and effectively without the involvement of nurses who had special expertise. This paper will examine how a specialty organization has developed and evolved over two decades, characterized by dramatic changes in the health care system. The involvement of nurses in nutrition support facilitated the early research in this area and was instrumental in developing a strong nursing role in the care of these patients.

Curriculum↗
PubMed1989

Expression of Epstein-Barr virus transformation-associated genes in tissues of patients with EBV lymphoproliferative disease.

Epstein-Barr virus (EBV) has been associated with serious or fatal lymphoproliferative disease in immunocompromised patients. EBV nuclear protein 2 and latent membrane protein are characteristically expressed in B lymphocytes proliferating in vitro in response to growth transformation by EBV. These two proteins are thought to be effectors of lymphocyte growth since they increase the expression of B-lymphocyte activation (CD23) and cell-adhesion (LFA 3 and ICAM 1) molecules in vitro. Using monoclonal antibody-immune microscopy, we have demonstrated that these two EBV proteins and their associated B-lymphocyte activation or adhesion molecules are expressed in the infiltrating B lymphocytes in immunocompromised patients with EBV lymphoproliferative disease. These monoclonal antibodies should be useful in the early diagnosis of EBV lymphoproliferative disease and in distinguishing it from other B-lymphocyte cancers associated with EBV, such as Burkitt's lymphoma. The finding of EBV nuclear protein 2 and latent membrane protein and their associated activation or adhesion molecules provides a further pathophysiologic link between EBV and the proliferation of B lymphocytes in immunocompromised patients.

Adult↗
PubMed1989

Nutritional support and gastrointestinal disease.

The use of nutritional support in patients with acute gastrointestinal disease requires a thorough knowledge of the pathophysiology and nutritional alterations that are caused by the disease process. Although nutritional therapy of a patient with gastrointestinal disease is not curative of the underlying disease, it does provide essential support to the patient, which improves response to, and eventual recovery from, illness. Special considerations need to be made to avoid complicating the patient's condition by inappropriate use of nutritional support solutions, which can lead to abnormal liver function.

Acute Disease↗
PubMed1987

Monoclonal antibodies to the latent membrane protein of Epstein-Barr virus reveal heterogeneity of the protein and inducible expression in virus-transformed cells.

Monoclonal antibodies specific for the 'latent membrane protein' (LMP) of Epstein-Barr virus (EBV), one of the effector proteins of EBV-induced B cell transformation, have been generated from mice immunized with a beta-galactosidase fusion protein containing the carboxyl half of the B95.8 strain LMP sequence. Four monoclonal IgG1 antibodies, designated CS.1, CS.2, CS.3 and CS.4, which together recognized at least three different epitopes on the molecule, were used to examine various aspects of LMP expression in B cell lines transformed in vitro. The pooled CS.1 to 4 reagent detected the LMPs encoded by each of 20 geographically distinct EBV isolates, despite a degree of inter-isolate heterogeneity in the size and antigenicity of the protein. In cell lines carrying the prototype B95.8 virus strain, particularly if these were virus producers, an additional lower molecular weight LMP was also detected; this appeared to correspond to the truncated form of the protein already predicted to exist from the analysis of B95.8 lytic cycle mRNAs. Attempts were made to identify an analogous truncated form of LMP in cell lines carrying other virus isolates after treatment with phorbol ester and/or sodium butyrate to induce virus production. Surprisingly these experiments showed that expression of the full length LMP molecule was itself strongly inducible by these agents; when monitored at the single cell level, this was a generalized response and was not restricted to cells entering a lytic cycle. Expression of LMP in EBV-transformed B cells therefore appears to be subject to a distinct type of regulation.

Antibodies, Monoclonal↗
PubMed1986

Epstein-Barr virus (EBV) antigen-specific leukocyte migration inhibition (LMI) in infectious mononucleosis (IM). I. Kinetics and response to a membrane protein on EBV-transformed cells.

Cell-mediated immune response of mononucleosis (IM) patients to Epstein-Barr virus (EBV)-determined antigens was measured by the leukocyte migration inhibition (LMI) assay. Patients in the acute phase of the disease failed to respond to partially purified nuclear antigen, EBNA, or to cell extracts that contained EBNA as the predominant EBV antigen. They showed a strong specific response to cell extracts enriched in early antigen (EA) and virus capsid antigen (VCA). The LMI response to EBNA appeared in convalescence in parallel with EBNA-specific antibodies, slightly later in children than in adults. Membrane fractions of EBV-carrying, virus nonproducer Raji cells induced an EBV-specific LMI at approximately the same time. A bacterial fusion protein containing the hydrophilic part of the virus-coded membrane antigen of latently EBV-infected cells also induced an EBV-specific response that parallelled the LMI reaction elicited by the Raji membrane fraction. This is in line with our previous finding (D. Sulitzeanu et al., J. Virol. 58, 230, 1986) that this fusion protein shares an epitope with Raji cell membranes.

Adolescent↗
PubMed1986

Definitive identification of a member of the Epstein-Barr virus nuclear protein 3 family.

Some Epstein-Barr virus (EBV) immune human antisera are known to react with a 142-kDa protein, EBV-encoded nuclear antigen 3 (EBNA3), which, like EBNA1 and EBNA2, is likely to be involved in the establishment of latent infection or growth transformation. We have now constructed gene fusions between Escherichia coli lacZ and an EBV DNA open reading frame (BERF1; BamHI E fragment rightward open reading frame 1), which is transcribed into an mRNA in latently infected cells. Purified hybrid protein from one of these constructs, chosen because of its reactivity with EBNA3-positive human antisera, was used to affinity purify the specific antibody from human antiserum. This specific antibody was used to prove that EBNA3 is encoded, at least in part, by BERF1, and that EBNA3 is in the nucleus of each latently infected cell. In rodent cells, BERF1 encodes a 120- to 130-kDa protein, which translocates to the nucleus and is recognized by EBNA3-positive human antisera. Two other proteins similar in size to EBNA3 are detected in latently infected cells by EBV immune human antisera. Two EBV open reading frames related to BERF1 may encode these proteins.

Animals↗