Overcoming parental intolerance in childhood nocturnal enuresis: a survey of professional opinion.
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Adult↗
Biomedical subjects
S McKenna
Publications and source records attributed to S McKenna.
Nottingham health profile scores predict the outcome and support aggressive revascularisation for critical ischaemia.
AIMS: to assess changes in health related quality of life (HRQoL) following peripheral arterial reconstruction for critical limb ischaemia (CLI). METHODS: sixty patients with CLI were prospectively evaluated with the Nottingham Health Profile (NHP) before and 3 and 12 months after arterial reconstruction. In addition, at 12 months, patients were asked if their expectations of the revascularisation had been met and whether they considered the surgical treatment had been worthwhile. RESULTS: primary amputations and mortality were 5% and 3% and after 12 months 12% and 12% respectively. Three months after surgery scores on the pain and sleep sections of the NHP had improved significantly (p < 0.05). These improvements were maintained at 12 months. CONCLUSION: revascularisation for CLI improves HRQoL and pre-operative health perceptions are related to surgical outcome.
Aged↗
BRCA1 and GADD45 mediated G2/M cell cycle arrest in response to antimicrotubule agents.
BRCA1 is a tumour suppressor gene implicated in the predisposition to early onset breast and ovarian cancer. We have generated cell lines with inducible expression of BRCA1 to evaluate its role in mediating the cellular response to various chemotherapeutic drugs commonly used in the treatment of breast and ovarian cancer. Induction of BRCA1 in the presence of Taxol and Vincristine resulted in a dramatic increase in cell death; an effect that was preceded by an acute arrest at the G2/M phase of the cell cycle and which correlated with BRCA1 mediated induction of GADD45. A proportion of the arrested cells were blocked in mitosis suggesting activation of both a G2 and a mitotic spindle checkpoint. In contrast, no specific interaction was observed between BRCA1 induction and treatment of cells with a range of DNA damaging agents including Cisplatin and Adriamycin. Inducible expression of GADD45 in the presence of Taxol induced both G2 and mitotic arrest in these cells consistent with a role for GADD45 in contributing to these effects. Our results support a role for both BRCA1 and GADD45 in selectively regulating a G2/M checkpoint in response to antimicrotubule agents and raise the possibility that their expression levels in cells may contribute to the toxicity observed with these compounds.
Antineoplastic Agents↗
Noncovalent interaction between ubiquitin and the human DNA repair protein Mms2 is required for Ubc13-mediated polyubiquitination.
Ubiquitin-conjugating enzyme variants share significant sequence similarity with typical E2 (ubiquitin-conjugating) enzymes of the protein ubiquitination pathway but lack their characteristic active site cysteine residue. The MMS2 gene of Saccharomyces cerevisiae encodes one such ubiquitin-conjugating enzyme variant that is involved in the error-free DNA postreplicative repair pathway through its association with Ubc13, an E2. The Mms2-Ubc13 heterodimer is capable of linking ubiquitin molecules to one another through an isopeptide bond between the C terminus and Lys-63. Using highly purified components, we show here that the human forms of Mms2 and Ubc13 associate into a heterodimer that is stable over a range of conditions. The ubiquitin-thiol ester form of the heterodimer can be produced by the direct activation of its Ubc13 subunit with E1 (ubiquitin-activating enzyme) or by the association of Mms2 with the Ubc13-ubiquitin thiol ester. The activated heterodimer is capable of transferring its covalently bound ubiquitin to Lys-63 of an untethered ubiquitin molecule, resulting in diubiquitin as the predominant species. In (1)H (15)N HSQC ((1)H (15)N heteronuclear single quantum coherence) NMR experiments, we have mapped the surface determinants of tethered and untethered ubiquitin that interact with Mms2 and Ubc13 in both their monomeric and dimeric forms. These results have identified a surface of untethered ubiquitin that interacts with Mms2 in the monomeric and heterodimeric form. Furthermore, the C-terminal tail of ubiquitin does not participate in this interaction. These results suggest that the role of Mms2 is to correctly orient either a target-bound or untethered ubiquitin molecule such that its Lys-63 is placed proximally to the C terminus of the ubiquitin molecule that is linked to the active site of Ubc13.
Binding Sites↗
Introns resolve the conflict between base order-dependent stem-loop potential and the encoding of RNA or protein: further evidence from overlapping genes.
Many eukaryotic genes are split into exons and introns, the latter being removed post-transcriptionally so that only exon sequences appear in cytoplasmic RNAs. Since introns appear in both protein-encoding RNAs and non-protein-coding RNAs, they interrupt genetic information per se, not just protein-encoding information. A DNA sequence has the potential to carry more than one type of genetic information, but different types may conflict. Thus, it has been proposed that introns arose because sequences were unable to contain concomitantly complete information for the encoding both of stem-loops and of cytoplasmic products (protein and/or RNA). Stem-loop potential is held to be selectively advantageous since it promotes the recombination-dependent correction of genetic errors. Stem-loop potential, the best local measure of which is base order-dependent stem-loop potential, tends to be less in exons than in introns. This is particularly evident in genes evolving rapidly under positive Darwinian selection, where the protein-encoding function is dominant. Evidence is now presented that the rare regions where genes overlap also impose excessive encoding demands so that the concomitant coding of base order-dependent stem-loop potential is decreased. Our results are consistent with the hypothesis that sequences with high stem-loop potential arose in the early 'RNA world'. Ancestors of modern genes would have entered this world when sequences (exons) encoding cytoplasmic products, were interspersed with sequences (introns) encoding selectively advantageous stem-loops. Purine-loading pressure would also have favoured intron formation.
Animals↗
Structure of a conjugating enzyme-ubiquitin thiolester intermediate reveals a novel role for the ubiquitin tail.
BACKGROUND: Ubiquitin-conjugating enzymes (E2s) are central enzymes involved in ubiquitin-mediated protein degradation. During this process, ubiquitin (Ub) and the E2 protein form an unstable E2-Ub thiolester intermediate prior to the transfer of ubiquitin to an E3-ligase protein and the labeling of a substrate for degradation. A series of complex interactions occur among the target substrate, ubiquitin, E2, and E3 in order to efficiently facilitate the transfer of the ubiquitin molecule. However, due to the inherent instability of the E2-Ub thiolester, the structural details of this complex intermediate are not known. RESULTS: A three-dimensional model of the E2-Ub thiolester intermediate has been determined for the catalytic domain of the E2 protein Ubc1 (Ubc1(Delta450)) and ubiquitin from S. cerevisiae. The interface of the E2-Ub intermediate was determined by kinetically monitoring thiolester formation by 1H-(15)N HSQC spectra by using combinations of 15N-labeled and unlabeled Ubc1(Delta450) and Ub proteins. By using the surface interface as a guide and the X-ray structures of Ub and the 1.9 A structure of Ubc1(Delta450) determined here, docking simulations followed by energy minimization were used to produce the first model of a E2-Ub thiolester intermediate. CONCLUSIONS: Complementary surfaces were found on the E2 and Ub proteins whereby the C terminus of Ub wraps around the E2 protein terminating in the thiolester between C88 (Ubc1(Delta450)) and G76 (Ub). The model supports in vivo and in vitro experiments of E2 derivatives carrying surface residue substitutions. Furthermore, the model provides insights into the arrangement of Ub, E2, and E3 within a ternary targeting complex.
Computer Simulation↗
The nursing management of diarrhoea and constipation before and after the implementation of a bowel management protocol.
Intensive care unit (ICU) patients frequently suffer problems associated with both diarrhoea and constipation. Strategies to optimise the management of these conditions need to focus on improving the communication between staff and ensuring effective treatment is implemented. The team involved in this study developed a Bowel Management Protocol (BMP). The effect of this BMP on the documentation of assessment and management of diarrhoea and constipation was evaluated using a quasi-experimental research design. Data were collected via a retrospective audit of medical records. Two groups of patient records were randomly sampled. The records of 60 patients who were admitted to ICU in the 6 months before the introduction of the BMP were accessed together with the records of 60 patients admitted in the 6 months following the introduction of the BMP. Data were collected regarding patient demographics and the assessment and management of bowel function before and after BMP introduction. The results indicated that a BMP improved documentation of the assessment of bowel function. In addition, there was an improvement in the documentation of nursing intervention in the presence of constipation and diarrhoea. These results have to be interpreted with caution because, despite random sampling over two 6 month periods, there were statistically significant differences in age, length of stay, method of feeding and medical diagnosis between the two groups. Further research into the effectiveness of using a BMP is recommended.
Adolescent↗
Crystal structure of the human ubiquitin conjugating enzyme complex, hMms2-hUbc13.
The ubiquitin conjugating enzyme complex Mms2-Ubc13 plays a key role in post-replicative DNA repair in yeast and the NF-kappaB signal transduction pathway in humans. This complex assembles novel polyubiquitin chains onto yet uncharacterized protein targets. Here we report the crystal structure of a complex between hMms2 (Uev1) and hUbc13 at 1.85 A resolution and a structure of free hMms2 at 1.9 A resolution. These structures reveal that the hMms2 monomer undergoes a localized conformational change upon interaction with hUbc13. The nature of the interface provides a physical basis for the preference of Mms2 for Ubc13 as a partner over a variety of other structurally similar ubiquitin-conjugating enzymes. The structure of the hMms2-hUbc13 complex provides the conceptual foundation for understanding the mechanism of Lys 63 multiubiquitin chain assembly and for its interactions with the RING finger proteins Rad5 and Traf6.
Adenosine Triphosphatases↗
Uncovering BRCA1-regulated signalling pathways by microarray-based expression profiling.
The introduction of microarray technology to the scientific and medical communities has dramatically changed the way in which we now address basic biomedical questions. Expression profiling using microarrays facilitates an experimental approach where alterations in the transcript level of entire transcriptomes can be simultaneously assayed in response to defined stimuli. We have used microarray analysis to identify downstream transcriptional targets of the BRCA1 (Breast Cancer 1) tumour-suppressor gene as a means of defining its function. BRCA1 has been implicated in the predisposition to early onset breast and ovarian cancer and while its exact function remains to be defined, roles in DNA repair, cell-cycle control and transcriptional regulation have been implied. In the current study we have generated cell lines with tetracycline-regulated, inducible expression of BRCA1 as a tool to identify genes, which might represent important effectors of BRCA1 function. Oligonucleotide array-based expression profiling identified a number of genes that were upregulated at various times following inducible expression of BRCA1 including the DNA damage-responsive gene GADD45 (Growth Arrest after DNA Damage). Identified targets were confirmed by Northern blot analysis and their functional significance as BRCA1 targets examined.
BRCA1 Protein↗
Regulation of virulence gene expression in Shigella flexneri, a facultative intracellular pathogen.
Shigella flexneri and its close relatives are facultative intracellular pathogens of humans and are the etiological agents of bacillary dysentery. These bacteria secrete proteins that enable them to enter human epithelial cells via an elaborate and fascinating cell biology. This behaviour depends on a complicated regulon of virulence genes, whose expression is controlled in response to a multiplicity of environmental signals. This review describes and attempts to interpret these gene control mechanisms.
Bacterial Toxins↗
Adaptation and validation of the rheumatoid arthritis quality of life scale for use in Canada.
OBJECTIVE: The Rheumatoid Arthritis Quality of Life questionnaire (RAQoL) was developed simultaneously in the UK and the Netherlands to measure quality of life in patients with RA. We adapted and validated the RAQoL for the English-Canadian and French-Canadian languages and culture. METHODS: The UK RAQoL was translated into French-Canadian by a bilingual translation panel. Separate lay panels were then used to ensure that this and the English-Canadian instruments were appropriate for use with Canadian patients. Interviews were conducted with 15 French-Canadian and 15 English-Canadian patients with RA to determine the content validity. Reliability and construct validity were established by means of test-retest mail surveys conducted with 92 French-Canadian and 87 English-Canadian RA patients. The survey consisted of the adapted RAQoL, the Health Assessment Questionnaire (HAQ), and a demographic questionnaire. RESULTS: The RAQoL was successfully adapted for both the French and English-Canadian cultures. Field testing showed both versions to be well received by respondents. Of the French-Canadian patients included in the postal survey, 52 responded at Time 1 and 50 at Time 2. For the English-Canadian sample, 54 responded at both time points. Missing data rates for the RAQoL were low and floor and ceiling effects were minimal. Test-retest reliability was good for both versions: 0.87 for the French-Canadian and 0.95 for the English-Canadian. Alpha coefficients (0.92 for the French-Canadian, 0.93 for the English-Canadian) showed the items to be adequately interrelated and scores on the measure showed moderate to high correlations with the HAQ, confirming construct validity. Both versions of the RAQoL were also able to distinguish patient groups that differed according to perceived health status and perceived severity of RA. In addition, the French-Canadian version was able to distinguish patients who rated today as bad or very bad from those who rated today as good or very good. CONCLUSION: The new versions of the RAQoL were well received by both French and English speaking Canadians. The psychometric quality of the adapted questionnaires means they are suitable for inclusion in clinical trials involving patients with RA.
Adult↗
Invisalign: technology or mythology?
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Adult↗
Deregulated expression of promyelocytic leukemia zinc finger protein in B-cell chronic lymphocytic leukemias does not affect cyclin A expression.
INTRODUCTION: The promyelocytic leukemia zinc finger (PLZF) gene encodes a transcription factor expressed in myeloid, lymphoid and CD34(+) progenitor cells. Structurally related to BCL-6, which is involved in human lymphoma, PLZF may have a role in proliferation, differentiation and survival of hematopoietic cells, that could be mediated by transcriptional repression of the cyclin A gene. MATERIALS AND METHODS: Quantitative competitive reverse transcription-polymerase chain reaction was used to measure the levels of expression of PLZF and cyclin A in normal leukocyte subsets (including CD19(+) lymphocytes, n=21) and malignant B lymphocytes (including B-chronic lymphocytic leukemias [B-CLL], n=63). Results obtained with this method were confirmed by Western and Northern blot analysis. Transactivation assays were performed using an expression construct for PLZF and two cyclin A promoter luciferase reporters in an Epstein-Barr virus (EBV)-transformed B-cell line. Cyclin A expression, cell growth kinetics, and cell cycle were analysed in stable clones of the Burkitt lymphoma (BL) B-cell line DG75 with inducible expression of PLZF, generated using the tetracycline-regulated expression system. RESULTS: Expression of PLZF was 100-fold downregulated in 90% B-CLL (56/63) compared to normal B lymphocytes (P<0.001). B-CLL patients with the highest levels of PLZF had a poorer survival (P<0.013). In transactivation assays, PLZF inhibited the activity of the cyclin A reporters by 50%, demonstrating that PLZF can repress cyclin A expression in non-malignant B lymphocytes. However, in B-CLL patients, the level of cyclin A expression was found to be within the normal range. Altered PLZF function in B lymphoid malignancies was further corroborated in the PLZF-regulatable DG75 clones, where induction of PLZF expression did not significantly alter the levels of cyclin A expression, the cell growth kinetics, or the cell cycle phase distribution. CONCLUSION: The lower survival of patients with the highest levels of PLZF suggests that this protein may be a marker of progression in B-CLL. The absence of co-ordinated regulation of PLZF and cyclin A genes in B-CLL and in a malignant B-cell line may indicate a loss of cyclin A control by PLZF in B-CLL and other B-cell disorders. Deregulation of PLZF could thus play a role in B-cell malignancy.
Antigens, CD↗
Application of a disease-specific, quality-of-life measure (QoL-AGHDA) in growth hormone-deficient adults and a random population sample in Sweden: validation of the measure by rasch analysis.
OBJECTIVE: Growth hormone deficiency (GHD) in adults has been associated with impaired health status and quality of life (QoL) in several studies using generic measures, and in a few studies using recently developed disease-specific measures. Theoretically, disease-specific measures may be more sensitive and succinct than generic measures, and hence prove convenient for general use in clinical practice. The present study sought to validate the scaling properties of the disease-specific QoL-AGHDA measure through the implementation of Rasch analysis. The study also sought to compare, by using the QoL-AGHDA, the QoL of a relatively large Swedish cohort of adults with untreated GHD with that of a reference population also from Sweden. PATIENTS: The QoL of 111 adults with untreated GHD from Stockholm and Göteborg was compared with that of 1448 adult subjects randomly selected from the population of Göteborg. MEASUREMENTS: The scaling properties of the QoL-AGHDA were assessed by investigating its fit to a dichotomous Rasch model. Rasch-transformed QoL scores from the QoL-AGHDA questionnaire were stratified by age and gender, and 95% confidence intervals were calculated. RESULTS: Rasch analysis of the QoL-AGHDA indicated the measure to be robust in terms of its unidimensionality and ordering properties, and lack of differential item functioning. The raw scores produced by the QoL-AGHDA are at the ordinal level. Non-overlapping 95% confidence intervals of Rasch-transformed interval scores in most age categories indicated that men and women with GHD had significantly lower QoL than the reference population. CONCLUSION: The Swedish QoL-AGHDA has good scaling properties, and hence can be considered a robust measure. It is suitable for assessing quality of life in adults with GH deficiency, and for making comparisons with adults who are not growth hormone deficient. Adult GH deficiency is associated with a significant impairment in QoL.
Adult↗
The neutralization of type I IFN biologic actions by anti-IFNAR-2 monoclonal antibodies is not entirely due to inhibition of Jak-Stat tyrosine phosphorylation.
A panel of monoclonal antibodies (mAb) derived against human interferon-alpha/beta receptor-2 (IFNAR-2) was evaluated for their ability to antagonize the biologic effects of type 1 interferons (IFN-alpha1, IFN-alpha2a, and IFN-beta). Anti-IFNAR-2 mAb 117.7, 35.9, 53.2, and 51.44 neutralized type I IFN-mediated antiviral, antiproliferative, and major histocompatibility complex (MHC) class I upregulation functions. However, only mAb 51.44 neutralized IFN-alpha2a and IFN-beta-mediated natural killer (NK) cell cytotoxicity. In BIAcore and cell binding studies, only mAb 51.44 and 234.28 inhibited IFN-alpha2a and IFN-beta binding to its receptor. The receptor blockade by mAb 51.44 and 234.28 resulted in the inhibition of IFN-alpha2a and IFN-beta-induced tyrosine phosphorylation of Jak1, Tyk2, Stat1/2/3, and IFNAR-1/2 and inhibition of IFN-stimulated gene factor 3 (ISGF3) formation. mAb 117.7, 35.9, and 53.2, although antagonists of IFN's biologic activities, did not block the binding of IFN-alpha/beta to its receptor. The 117.7 mAb, representative of this class of receptor nonblocking mAb, induced hyper-tyrosine phosphorylation of IFNAR-2 in the presence of IFN-alpha/beta but did not inhibit IFN-alpha/beta-induced Jak-Stat tyrosine phosphorylation and ISGF3 complex formation. These results show that the neutralization of type I IFN biologic actions by anti-IFNAR-2 mAb cannot be entirely explained by inhibition of Jak-Stat tyrosine phosphorylation.
Antibodies, Monoclonal↗
Rapid voluntary testing and counseling for HIV. Acceptability and feasibility in Zambian antenatal care clinics.
Voluntary testing and counseling (VTC) for HIV/AIDS is now widely accepted as an effective HIV prevention and control strategy among heterosexual couples in sub-Saharan Africa. The most appropriate format and venue for VTC remains a topic of debate among clinicians and public health professionals. Our research done in Lusaka, Zambia, took a tripartite approach to exploring the most acceptable format and venue for VTC: a community survey of attitudes towards VTC, a pre- and postcounseling knowledge survey, and a pilot study of same-day VTC in urban antenatal care clinics. A community survey of 181 individuals was conducted in July-August 1996 based on a structured questionnaire. A pre- and post-VTC intervention knowledge survey was conducted during the same period among 82 couples attending the Zambia-UAB HIV Research Project (ZUHRP) HIV VTC center in Lusaka. Finally, same-day HIV VTC was pilot tested in six antenatal clinic locations during February-May 1997 and June-August 1998. The community survey revealed that 98% of participants support promotion of HIV VTC in the community and 83.8% prefer the same-day testing format. The knowledge survey revealed misconceptions about discordance within a couple and perinatal transmission of HIV. Pilot testing in antenatal clinics was well received, with 84% of pregnant women requesting testing and 25% having positive HIV serologies. Women with primary school or less education, those seeking antenatal care in local clinics, and those seen before the third trimester of pregnancy were more likely to request HIV testing. Testing and counseling for HIV were shown to be feasible and effective in the antenatal clinic setting. Implementation of same-day HIV VTC in antenatal clinics is an effective strategy to prevent vertical transmission and should be expanded to include couples to leverage a decrease in heterosexual transmission as well.
Acquired Immunodeficiency Syndrome↗
Alterations of the retinoic acid receptor alpha (RAR alpha) gene in myeloid and lymphoid malignancies.
The retinoic acid receptor alpha (RAR alpha) protein plays a central role in myeloid differentiation, and chromosomal translocations disrupting the RAR alpha gene are implicated in the development of acute myeloid leukaemia (AML). To identify haemopoietic malignant disorders which may also be linked to RAR alpha abnormalities, Southern blot analysis was performed in DNA from 153 patients with haematological malignancies other than AML FAB type M3 using RAR alpha cDNA probes. Alterations of RAR alpha were detected in 1/42 myelodysplastic syndromes (MDS), 2/24 AML, 3/47 B-chronic lymphocytic leukaemias (B-CLL), 0/40 lymphomas and 0/60 normal individuals. These data strongly suggest that alterations of RAR alpha might predispose for myeloid and lymphoid disorders.
Blotting, Northern↗
Identification of an IL-7-associated pre-pro-B cell growth-stimulating factor (PPBSF). II. PPBSF is a covalently linked heterodimer of IL-7 and a Mr 30,000 cofactor.
Evidence is provided in a companion paper for an IL-7-associated molecular complex that selectively stimulates the proliferation and presumptive differentiation of pre-pro-B cells in our long-term bone marrow culture system and "primes" them to proliferate in response to monomeric IL-7. Here, Western immunoblot analysis reveals that this pre-pro-B cell growth-stimulating factor (PPBSF) is a self-assembling heterodimer of IL-7 and a cofactor with a M(r) of 30,000. Thus, when developed with anti-IL-7 mAb, PPBSF migrates electrophoretically as a covalently bound approximately 55-kDa molecule under nonreducing conditions but dissociates under reducing conditions. Furthermore, the addition of rIL-7 or native IL-7 to medium conditioned by stromal cells from IL-7 gene-deleted (-/-) mice results in the formation of active 45-kDa and 55-kDa molecular complexes, respectively. Antiserum prepared in IL-7(-/-) mice against affinity-purified PPBSF contained separable reactivities for IL-7 and the non-IL-7 component of PPBSF. The PPBSF cofactor detected by this antiserum migrates as an approximately 30-kDa molecule and is able to maintain the viability, but not the proliferation, of pre-pro-B cells. Furthermore, the cofactor is produced constitutively by IL-7(-/-) and IL-7(+/+) bone marrow stromal cells under pro-B- but not pre-B-type culture conditions. Consequently, IL-7 appears to exist almost entirely as a heterodimer (i.e., PPBSF) in pro-B-type cultures, whereas it exists almost entirely as a monomer in pre-B-type cultures. Although the identity of the PPBSF cofactor remains to be determined, it does not appear to be stem cell factor, insulin-like growth factor-1, thymic stromal-derived lymphopoietin, flt3, stromal cell-derived factor-1, or IL-7R.
Animals↗