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Biomedical subjects

C Flaherty

Publications and source records attributed to C Flaherty.

6 recordsLinked to original sources
PubMed1992

AraC protein contacts asymmetric sites in the Escherichia coli araFGH promoter.

AraC protein regulates the transcription of arabinose transport and catabolic operons in Escherichia coli through interaction with specific DNA sequences in the promoter regions of the operons. The interaction of AraC protein with two binding sites in the araFGH promoter was determined and compared to previously studied AraC binding sites in the araBAD promoter. Methylation and ethylation interference assays show that AraC protein binds along one side of the DNA to four adjacent major groove regions at each of the araFG1 and araFG2 sites. Mutations within any of the four regions of araFG1 greatly reduce protein binding in vitro. The promoter function in vivo is also greatly reduced, indicating that all four regions of the binding site are required. The chemical interference and genetic data, combined with the consensus sequence for AraC protein binding to ara promoters, support a binding motif in which two directly repeated units each span two adjacent turns of the DNA helix. The function of the two AraC binding sites was also examined. The proximal araFG1 site is required for promoter activation, whereas the distal araFG2 site has only a slight effect on the promoter activity.

Alkylation↗
PubMed1992

Sequence elements in the Escherichia coli araFGH promoter.

The Escherichia coli araFGH operon codes for proteins involved in the L-arabinose high-affinity transport system. Transcriptional regulation of the operon was studied by creating point mutations and deletions in the control region cloned into a GalK expression vector. The transcription start site was confirmed by RNA sequencing of transcripts. The sequences essential for polymerase function were localized by deletions and point mutations. Surprisingly, only a weak -10 consensus sequence, and no -35 sequence is required. Mutation of a guanosine at position -12 greatly reduced promoter activity, which suggests important polymerase interactions with DNA between the usual -10 and -35 positions. A double mutation toward the consensus in the -10 region was required to create a promoter capable of significant AraC-independent transcription. These results show that the araFGH promoter structure is similar to that of the galP1 promoter and is substantially different from that of the araBAD promoter. The effects of 11 mutations within the DNA region thought to bind the cyclic AMP receptor protein correlate well with the CRP consensus binding sequence and confirm that this region is responsible for cyclic AMP regulation. Deletion of the AraC binding site nearest the promoter, araFG1, eliminates arabinose regulation, whereas deletion of the upstream AraC binding site, araFG2, has only a slight effect on promoter activity.

Arabinose↗
PubMed1992

Dysfunctional grieving.

Dysfunctional grieving represents a failure to follow the predictable course of normal grieving to resolution (Lindemann, 1944). When the process deviates from the norm, the individual becomes overwhelmed and resorts to maladaptive coping. The process implies movement toward assimilation to or accommodation of the loss, resulting in progression toward social, psychological, and medical morbidity. Nurses will better assess the needs of the client with adequate information about the client's recent losses and perception of those losses. Such an assessment, in conjunction with an understanding of the signs, symptoms, and predisposing factors of complicated bereavement, will enable the nurse to develop a plan of effective intervention. Both case examples illustrate unresolved grief. In Case Example 1, the patient denied the importance of the relationship, which became masked with displaced anger and therefore delayed the grieving process. In Case Example 2, the patient's attempts at grieving over the loss of her son were complicated by her long-standing struggle with her husband's infidelity at the time of her pregnancy. The revelation of secondary loss is common in dysfunctional grieving. Resolution of grief encompasses not only accommodation to object loss, but also change in the pathological behaviors incorporated into the patient's self-image as a result of the loss (Lazare, 1979). The maladaptive operations employed by these patients to preserve self-image were discarded as the grief resolved. The focus of therapy included the loss of those behaviors as they were relinquished to prevent the patient from experiencing further anxiety and sense of loss (Zisook, 1987).(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Psychological↗
PubMed1986

Clinical measures to assess the practice and efficiency of breast self-examination.

If women examine their breasts thoroughly and regularly they may promptly recognize abnormal tissue changes. The level of skill and motivation required for effective breast self-examination (BSE), however, is very high. In a prospective study of 304 patients with newly diagnosed breast cancer, 165 (54%) claimed to practice BSE. On comparison with the remaining 139, the BSE practitioners reported their symptoms sooner than the nonpractitioners, and presented more often with clinically early tumors. There was, however, no difference in tumor size, and pathologic status of axillary nodes between the two groups. There were 60 patients who discovered the abnormalities during self-examination. On comparison with the remaining 244, significantly more BSE discoverers had shorter patient delay in presentation, but there was no significant difference in tumor size, clinical stage, and nodal status. It is concluded that these or similar clinical measures must be used in assessing the effectiveness of population-based BSE campaigns.

Age Factors↗
PubMed1986

Breast screening clinic versus health education session as outlets for education in breast self-examination.

A population based programme to educate women in breast self-examination (BSE) was organised as part of the UK Trial of Early Detection of Breast Cancer. Women who responded to an invitation to a meeting were educated in groups and were not routinely screened. Open access clinics offered x ray and clinical examination to all women in the study age group of 45 to 64. Women who presented for screening without prior BSE education were taught individually by clinic staff. Women taught by the two methods were surveyed by post and their BSE practice since education was compared. It was hypothesised that the women taught in clinics, who had been reassured of their breast normality, would practice BSE more regularly and correctly. Results did not confirm this hypothesis. Lower standards of practise and a higher level of anxiety at the time of survey were found in the group who presented at a free access clinic and had received individual teaching at the time of screening.

Breast↗