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Biomedical subjects

J L O'Brien

Publications and source records attributed to J L O'Brien.

31 records · Page 2Linked to original sources

Molecular characterization of a third malic enzyme-like AP65 adhesin gene of Trichomonas vaginalis.

Adherence to the vaginal epithelium by the sexually transmitted parasite Trichomonas vaginalis is mediated by four trichomonad surface proteins (AP65, AP51, AP33 and AP23). We recently showed that the 65-kDa adhesin is a member of a multigene family comprised of two similar but distinct proteins, AP65-1 and AP65-2, encoded by the genes ap65-1 and ap65-2, respectively. An additional immuno-crossreactive clone, the 1.2 kb F11.1 cDNA, was isolated from a phagemid expression library and encoded a fusion protein of approximately 46,000 daltons (46 kDa) that bound to HeLa cell surfaces. A significant portion of the 5' end was missing which, using the 5'-RACE method, was obtained and combined with the F11.1 clone to give a full-length cDNA. The ap65-3 gene encoded for a protein of 567 amino acids with a molecular mass of 63.1 kDa. The gene showed 88% and 96% identity at the DNA level with ap65-1 and ap65-2, respectively. Restriction mapping confirmed that the three AP65 genes are different. Southern analysis revealed that the ap65-3 gene is present in the T. vaginalis genome in multiple copies. Experiments with agar clones of trichomonads showed that each gene of the multigene family is present in all parasites, and Northern analysis showed that ap65-3 is expressed and transcriptionally regulated by iron. The ap65-3 gene had a leader sequence and, as with ap65-1 and ap65-2, showed significant homology to malic enzyme. Finally, analysis of the 3'-untranslated regions revealed that the transcript of ap65-3 had a long poly (A) tail in comparison to ap65-1 and ap65-2. Even more intriguing, sequences were found that may relate to differential degradation of select AP65 transcripts, such as the sequence motifs AUUUA for ap65-1 mRNA and UUAUUUAU for the ap65-2 mRNA, which were not found for ap65-3.

Amino Acid Sequence↗

Implementation of total quality management: conventional wisdom versus reality.

Hospitals nationwide are beginning to implement continuous quality improvement (CQI) (Barsness et al. 1993; Kosta 1992). In large part this is due to the belief that the implementation of CQI will lead to higher quality patient care, improved patient satisfaction, better employee morale, and lower cost service delivery. However, to date there have been few empirical studies of CQI implementation efforts in healthcare (Shortell et al. 1994).

Chief Executive Officers, Hospital↗

Keys for successful implementation of total quality management in hospitals.

This article reports the findings of an analysis of the implementation of continuous quality improvement (CQI) or total quality management (TQM) programs in 10 hospitals. This analysis is the result of a 2-year study designed to identify and assess the ingredients that lead to the successful implementation of CQI programs in acute care hospitals.

Hospital Administration↗

An integrative model for organization-wide quality improvement: lessons from the field.

This article describes a model of CQI that is designed to characterize the elements necessary for successfully improving quality at an organization-wide level; describe and understand the organizational dynamics in implementing an organization-wide effort; and aid in diagnosing and solving common implementation challenges. Three cases illustrate the model and how it can be used.

Health Services Research↗

Cloning and molecular characterization of two genes encoding adhesion proteins involved in Trichomonas vaginalis cytoadherence.

Cytoadherence to the vaginal epithelium is a critical step in infection by the eukaryotic flagellate Trichomonas vaginalis. Four trichomonad surface proteins (AP65, AP51, AP33 and AP23) mediate cytoadherence. The cDNA encoding the AP65 adhesin was isolated from a phagemid cDNA expression library by screening with antiserum and monoclonal antibody (mAb) raised against the purified trichomonad AP65 protein. Two clones, F11.2 and F11.5, coded for immuno-crossreactive recombinant proteins that possessed functional properties equal to the T. vaginalis AP65 adhesin. Analysis of full-length sequences corresponding to the F11.2 and F11.5 cDNAs revealed that both contained 1701-base open reading frames (ORFs) that encoded proteins of 63 281 daltons and 83 087 daltons, respectively. Comparison of the full-length sequences showed 87% identity at the nucleotide level and 91% identity at the protein level. Restriction-enzyme mapping and Southern analysis reaffirmed the distinctness of the F11.2 and F11.5 cDNAs, indicating that two different AP65 genes (now called ap65-1 and ap65-2) are present in the T. vaginalis genome in at least two copies each. Northern analysis detected high levels of transcript of approximately 1.8 kb for both ap65-1 and ap65-2 genes in trichomonads grown only in high-iron medium, confirming the transcriptional regulation of adhesin synthesis by iron. Homology searches revealed significant similarity (38% amino acid identity and 54% nucleotide identity) to malic enzymes. However, purified malic enzyme and mAb to AP65 crossreactive with malic enzyme neither inhibited cytoadherence of T. vaginalis to host cells nor prevented binding of the trichomonad AP65 to HeLa cells in a ligand assay.

Amino Acid Sequence↗

Assessing the evidence on CQI: is the glass half empty or half full?

Review of the literature on CQI/TQM in both health care and non-health care settings reveals some evidence of a positive impact for selected dimensions of CQI/TQM. There is little research, however, that examines CQI/TQM as a holistic integrated approach to quality improvement, nor are there many studies that go beyond single or small sample case studies. Using a conceptual framework involving cultural, technical, strategic, and structural dimensions, a number of barriers to CQI implementation are identified along with suggestions for high-priority areas of research.

Evaluation Studies as Topic↗

Assessing the impact of continuous quality improvement/total quality management: concept versus implementation.

OBJECTIVE: This study examines the relationships among organizational culture, quality improvement processes and selected outcomes for a sample of up to 61 U. S. hospitals. DATA SOURCES AND STUDY SETTING: Primary data were collected from 61 U. S. hospitals (located primarily in the midwest and the west) on measures related to continuous quality improvement/total quality management (CQI/TQM), organizational culture, implementation approaches, and degree of quality improvement implementation based on the Baldrige Award criteria. These data were combined with independently collected data on perceived impact and objective measures of clinical efficiency (i.e., charges and length of stay) for six clinical conditions. STUDY DESIGN: The study involved cross-sectional examination of the named relationships. DATA COLLECTION/EXTRACTION METHODS: Reliable and valid scales for the organizational culture and quality improvement implementation measures were developed based on responses from over 7,000 individuals across the 61 hospitals with an overall completion rate of 72 percent. Independent data on perceived impact were collected from a national survey and independent data on clinical efficiency from a companion study of managed care. PRINCIPAL FINDINGS: A participative, flexible, risk-taking organizational culture was significantly related to quality improvement implementation. Quality improvement implementation, in turn, was positively associated with greater perceived patient outcomes and human resource development. Larger-size hospitals experienced lower clinical efficiency with regard to higher charges and higher length of stay, due in part to having more bureaucratic and hierarchical cultures that serve as a barrier to quality improvement implementation. CONCLUSIONS: What really matters is whether or not a hospital has a culture that supports quality improvement work and an approach that encourages flexible implementation. Larger-size hospitals face more difficult challenges in this regard.

Cross-Sectional Studies↗

Nevus of Ota and leptomeningeal melanocytic lesions.

Two patients with congenital nevus of Ota developed intracranial malignant melanocytic tumors. One had a localized tumor that resembled a melanocytoma, but the other had a more highly malignant tumor that diffusely seeded the leptomeninges. There are 10 prior cases in the world literature. These cases are contrasted with the other disorders in which melanotic skin lesions are associated with CNS melanocytic tumors, including neurocutaneous melanosis, cellular blue nevus, and metastatic malignant melanoma. Each disorder tends to involve particular sites of the CNS. The nevus of Ota can be considered a neurocristopathy and, rarely, may give rise to malignant CNS lesions.

Adult↗

New trends in hospital-based services for the elderly.

What types of long-term care services are hospitals providing for the elderly? An American Hospital Association survey reveals the types of services hospitals currently provide, including specialized geriatric programs, and what services they are likely to provide in the future.

Aged↗

Lorcainide. A comparative trial with quinidine gluconate in patients with previously untreated ventricular arrhythmias.

The efficacy of a new antiarrhythmic agent, lorcainide, was compared with that of quinidine gluconate in a fixed-dose, randomized, crossover trial. Of 26 previously untreated patients with frequent ventricular ectopic beats documented by 24-hour ambulatory monitoring, 17 completed four weeks of therapy with quinidine and 12 with lorcainide. Of 22 patients receiving both drugs, early termination of therapy due to side effects occurred in ten (45 percent) patients receiving lorcainide and five (23 percent) receiving quinidine. Lorcainide (100 mg twice daily or three times daily, dependent on body weight) effectively suppressed ventricular arrhythmias in seven of 12 (58 percent) patients completing four weeks of therapy, and suppression by quinidine gluconate (324 mg three times daily) occurred in five of 12 (59 percent) patients. We conclude that in a dose of 100 mg twice or three times daily, lorcainide is as effective as quinidine gluconate, 324 mg three times daily, for the suppression of chronic ventricular arrhythmias. However, the high incidence of adverse reactions experienced with lorcainide make it an unacceptable agent for first-line antiarrhythmic therapy.

Adult↗