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Biomedical subjects

L King

Publications and source records attributed to L King.

At least 37 records · Page 2Linked to original sources
PubMed2000

Drawing up and administering intramuscular injections: a review of the literature.

Drawing up and administering intramuscular injections: a review of the literature Intramuscular (IM) injections have been an integral part of drug administration in nursing practice for almost half a century. However, there are some conflicting practices which warrant investigation to determine their effectiveness in this aspect of patient care. To this end, this paper presents the results of a literature review which was carried out in order to establish current understanding of present day knowledge, procedures and guidelines for the administration of IM injections. Areas addressed within this review include injection sites used, injuries associated with IM injections, issues surrounding needle selection and volume administered through IM injections, injection techniques and nursing skills associated with IM injections. Synthesis of the research reviewed allows the development of research-based guidelines for this skill. These guidelines offer a framework for nurses who wish to provide practice in line with current research into the process of drawing up and administration of intramuscular injections.

Clinical Competence↗
PubMed2000

Trends of polycyclic aromatic hydrocarbon levels and mutagenicity in Santiago's inhalable airborne particles in the period 1992-1996.

Trends of polycyclic aromatic hydrocarbons (PAHs) for 1992-1996 (cold season) and their mutagenic activity were investigated in organic extracts from the Santiago, Chile, inhalable particles (PM(10)). The highest PAH concentrations were observed in 1992 and declined dramatically in the following years. During this period, total PAHs decreased 85%, carcinogenic PAHs 82%, and benzo[a]pyrene, the most potent carcinogen, 85%. In spite of this significant decrease, PAH levels in respirable particles were higher than those reported in recent studies in Australia, Europe, and the United States. PAH profiles were analyzed by principal component (PC) analysis and Pearson correlation analysis. PC1 represents 71% of the variance, suggesting that most PAHs might originate predominantly from one main generic source. Higher correlations were obtained for the major carcinogenic PAHs. Most of the samples assayed were highly mutagenic to Salmonella typhimurium both in the presence and in the absence of metabolic activation system (S9), especially in the coarse fraction, but direct mutagenicity did not decline significantly. Incubation of calf thymus DNA with organic extracts from particulate matter and xanthine oxidase allowed the detection of five nitro-PAH-DNA adducts. Thus, nitroarenes might play an important role in the mutagenic activity of inhalable particles in Santiago, representing a high risk for human health.

Administration, Inhalation↗
PubMed2000

Moving out of the laboratory: does nicotine improve everyday attention?

The most robust demonstrations of the nicotine-related performance effects on human cognitive processes are seen in tasks that measure attention. If nicotine does have some potential for enhancing attention, the obvious question to ask is whether the effects demonstrated in the laboratory hold any significance for real-life performance. This paper describes three studies that compare the effects in smokers of a single own brand cigarette on laboratory tests of attention and on everyday analogues of these laboratory tasks. In the laboratory measures of sustained attention and in the everyday analogue, performance advantages were registered in the smoking condition. These benefits were observed in smokers who abstained for a self-determined period of not less than 2 h. The studies were unable to replicate previous research reporting positive effects of smoking on a laboratory task of selective attention, the Stroop task. Small but significant improvements in performance were registered in the everyday analogues, which involved sustaining attention in a dual task situation, a telephone directory search task and a map search task. In addition, smokers showed a significant colour-naming decrement for smoking-related stimuli in the Stroop task. This attentional bias towards smoking-related words occurred independent of whether they had abstained or recently smoked an own brand cigarette. The effect is discussed in terms of the two-component model of processing bias for emotionally valenced stimuli.

Adolescent↗
PubMed2000

Coreceptor competition for association with CD4 may change the susceptibility of human cells to infection with T-tropic and macrophagetropic isolates of human immunodeficiency virus type 1.

The chemokine receptors CCR5 and CXCR4 were found to function in vivo as the principal coreceptors for M-tropic and T-tropic human immunodeficiency virus (HIV) strains, respectively. Since many primary cells express multiple chemokine receptors, it was important to determine if the efficiency of virus-cell fusion is influenced not only by the presence of the appropriate coreceptor (CXCR4 or CCR5) but also by the levels of other coreceptors expressed by the same target cells. We found that in cells with low to medium surface CD4 density, coexpression of CCR5 and CXCR4 resulted in a significant reduction in the fusion with CXCR4 domain (X4) envelope-expressing cells and in their susceptibility to infection with X4 viruses. The inhibition could be reversed either by increasing the density of surface CD4 or by antibodies against the N terminus and second extracellular domains of CCR5. In addition, treatment of macrophages with a combination of anti-CCR5 antibodies or beta-chemokines increased their fusion with X4 envelope-expressing cells. Conversely, overexpression of CXCR4 compared with CCR5 inhibited CCR5-dependent HIV-dependent fusion in 3T3.CD4.401 cells. Thus, coreceptor competition for association with CD4 may occur in vivo and is likely to have important implications for the course of HIV type 1 infection, as well as for the outcome of coreceptor-targeted therapies.

3T3 Cells↗
PubMed2000

CCR8 on human thymocytes functions as a human immunodeficiency virus type 1 coreceptor.

To determine whether human immunodeficiency virus type 1 (HIV-1) coreceptors besides CXCR4 and CCR5 are involved in HIV-1 infection of the thymus, we focused on CCR8, a receptor for the chemokine I-309, because of its high expression in the thymus. Similar levels of CCR8 mRNA were detected in immature and mature primary human thymocytes. Consistent with this, [(125)I]I-309 was shown to bind specifically and with similar affinity to the surface of immature and mature human thymocytes. Fusion of human thymocytes with cells expressing HIV-1 X4 or X4R5 envelope glycoprotein was inhibited by I-309 in a dose-dependent manner. In addition, I-309 partially inhibited productive infection of human thymocytes by X4, R5, and X4R5 HIV-1 strains. Our data provide the first evidence that CCR8 functions as an HIV-1 coreceptor on primary human cells and suggest that CCR8 may contribute to HIV-1-induced thymic pathogenesis.

Chemokine CCL1↗
PubMed2000

Using brief assessments to evaluate aberrant behavior maintained by attention.

We examined the use of brief functional assessments to identify idiosyncratic variables associated with aberrant behavior maintained by positive reinforcement in the form of attention. Two participants with severe developmental disabilities and their parents were involved in the assessment and treatment evaluation process. A modified attention condition was introduced, which involved both parents interacting with a third person. Results of the assessment demonstrated that aberrant behavior occurred only in the modified attention condition for both participants. Treatment consisted of the parents delivering attention on a fixed-time schedule during this specific social context. Results indicated that the treatment reduced problem behavior. Follow-up evaluations with 1 participant indicated maintenance of treatment effects for up to 6 months.

Adult↗
PubMed1999

Specificity of peptide-induced depolymerization of the recombinant carboxy-terminal fragment of BiP/GRP78.

In the present study, we have used a non-denaturing gel electrophoresis assay to characterize the specificity of the peptide-induced depolymerization process of the isolated recombinant C-terminal domain (C30) of the molecular chaperone BiP, in the presence of specific synthetic peptides and with the neuropeptide Substance P. In the absence of peptidic ligand, C30 self-associates readily into multiple oligomeric species. Upon peptide addition, C30 oligomers convert into dimers, then into monomers. Our data indicate that the algorithm we previously developed to predict putative BiP binding sites in any protein sequence is also a good indicator as to whether a peptide can efficiently induce depolymerization of the C-terminal peptide binding domain and stimulate the ATPase activity of the full-length protein.

Amino Acid Sequence↗
PubMed1999

N-acylglycine amidation: implications for the biosynthesis of fatty acid primary amides.

Bifunctional peptidylglycine alpha-amidating enzyme (alpha-AE) catalyzes the O2-dependent conversion of C-terminal glycine-extended prohormones to the active, C-terminal alpha-amidated peptide and glyoxylate. We show that alpha-AE will also catalyze the oxidative cleavage of N-acylglycines, from N-formylglycine to N-arachidonoylglycine. N-Formylglycine is the smallest amide substrate yet reported for alpha-AE. The (V/K)app for N-acylglycine amidation varies approximately 1000-fold, with the (V/K)app increasing as the acyl chain length increases. This effect is largely an effect on the KM,app; the KM,app for N-formylglycine is 23 +/- 0.88 mM, while the KM,app for N-lauroylglycine and longer chain N-acylglycines is in the range of 60-90 microM. For the amidation of N-acetylglycine, N-(tert-butoxycarbonyl)glycine, N-hexanoylglycine, and N-oleoylglycine, the rate of O2 consumption is faster than the rate of glyoxylate production. These results indicate that there must be the initial formation of an oxidized intermediate from the N-acylglycine before glyoxylate is produced. The intermediate is shown to be N-acyl-alpha-hydroxyglycine by two-dimensional 1H-13C heteronuclear multiple quantum coherence (HMQC) NMR.

Adult↗
PubMed1999

"First aid for scalds" campaign: reaching Sydney's Chinese, Vietnamese, and Arabic speaking communities.

OBJECTIVES: As a serious yet preventable problem, scald injuries in children have been a priority for prevention in Australia and other developed countries. Not only can the occurrence of scalds be prevented, but immediate first aid treatment offers an effective method for secondary prevention, reducing the severity of scalds. Despite the success of scald prevention initiatives, local evidence suggested that first aid knowledge was lacking in some minority ethnic groups. To redress this gap, the "First Aid for Scalds" campaign for those from a non-English speaking background was specifically targeted to three ethnic groups (Vietnamese, Chinese, and Arabic), with the aim of increasing the proportions of parents and caregivers who had correct knowledge of first aid treatment for scalds. The primary strategy was a media campaign, including advertisements on ethnic radio and in ethnic newspapers. METHODS: The evaluation design included formative research and impact evaluation. The impact evaluation study involved random population based telephone surveys with each of the three language groups, before and after the campaign, to assess the reach and effectiveness of the campaign. RESULTS: After the campaign, there were significant increases in the proportion of people who knew the correct first aid treatment for scalds. There were substantial variations in campaign recall and knowledge between each of the three language groups. The largest improvement was found in the Vietnamese group. CONCLUSION: The association between campaign recall and increase in correct knowledge, and the absence of any similar interventions during the campaign period, give credence to the conclusion that the changes observed were a result of the campaign. The results demonstrate the value of community based injury prevention campaigns specifically targeting linguistically diverse communities.

Accident Prevention↗
PubMed1999

Experience in treating recalcitrant scalp psoriasis with automated shampooing and debridement.

We report the cumulative clinical experience and financial implications of treating severe scalp psoriasis in an outpatient phototherapy center by means of an automated scalp debridement unit. Benefits of this approach included increased patient and staff satisfaction, enhanced response of recalcitrant scalp psoriasis, and detection of scalp dermatoses mimicking psoriasis.

Adolescent↗
PubMed1999

Erratum

The paper 'Interference of rheumatoid factor activity by aspartame, a dipeptide methyl ester' by Paul A. Ramsland, Bahereh F. Movafagh, Morris Reichlin and Allen B. Edmundson, J. Mol. Recognit. 1999; 12: 249--257, was published without the required colour plates. The publisher would like to apologise for this omission. The article is reprinted here in full. Please replace the previously published pages with those following. The electronic version of the article, including the colour plates, can be downloaded from the Wiley Interscience website at http://www.interscience.wiley.com. The plates have been included in the original paper, which appeared in Issue 4 of the journal.

Journal Article↗
PubMed1998

Substrate binding induces depolymerization of the C-terminal peptide binding domain of murine GRP78/BiP.

To investigate the role of each domain in BiP/GRP78 function, we have used a full-length recombinant BiP engineered to contain two enterokinase sites; one site is located after an N-terminal FLAG epitope, and a second site has been inserted at the junction between the N- and C-terminal domains (FLAG-BiP.ent). FLAG-BiP.ent oligomerizes into multiple species that interconvert with each other in a slow, concentration- and temperature-dependent equilibrium. Binding of ATP or AMP-PNP (adenosine 5'-(beta, gamma-imino)triphosphate), but not ADP, or of a peptidic substrate induces depolymerization of FLAG-BiP.ent and stabilization of monomeric species. Enterokinase cleavage of monomeric, nucleotide-free BiP.ent results in the physical dissociation of the 44-kDa N-terminal ATPase fragment (N44.ent) from the 30-kDa C-terminal substrate binding domain (C30.ent). Upon dissociation, the freed C-terminal substrate binding domain readily undergoes self-association while N44.ent remains monomeric. Enterokinase cleavage performed in the presence of a synthetic peptide prevents oligomerization of the freed C30.ent domain. Addition of ATP during enterokinase cleavage has no effect on C30.ent oligomerization. Our data clearly indicate that binding of a specific peptide onto the C-terminal domain, or ATP onto the N-terminal domain, induces internal conformational change(s) within the C30 domain that result(s) in BiP depolymerization.

Adenosine Triphosphate↗
PubMed1998

Ace2p, a regulator of CTS1 (chitinase) expression, affects pseudohyphal production in Saccharomyces cerevisiae.

Some diploid strains of Saccharomyces cerevisiae can grow both as a spherical yeast form and as a filamentous pseudohyphal form. Most yeasts capable of forming pseudohyphae possess a functional FLO8 gene. We show that disrupting the ACE2 transcription factor results in the production of pseudohyphae in a flo8-1 background. Disrupting the CTS1 (chitinase) gene also produces pseudohyphal growth in this background, but at a reduced level. Invasion of solid media by haploid and diploid cells is increased in ACE2 disruptions, but the diploids adhere poorly to the agar. Sigma1278b-derived strains, which generally produce pseudohyphae, have about 30-fold lower chitinase activity than other strains.

Cell Adhesion↗