Characterization of mutations in the b subunit of F1F0 ATP synthase in Escherichia coli

Site-directed mutagenesis was used to investigate the restrictions on Ala-79 of the b subunit in F1F0 adenosine triphosphate synthase. This amino acid had been previously identified as particularly sensitive to mutation (McCormick, K. A., and Cain, B. D. (1991) J. Bacteriol. 173, 7240-7248). Mutant uncF (b) genes were placed under control of the lac promoter and monitored for F1F0 ATP synthase function in an uncF(b) deletion strain. Three deleterious bAla-79 mutations were moved to the unc operon in the chromosome by homologous recombination. Decreases in enzymatic activity in the uncF (b) mutant strains resulted from reduced amounts of enzyme. With the exception of the bAla-79-->Pro mutation, high expression of mutant uncF (b) genes resulted in increases in F1F0 ATP synthase activity which were sufficient to overcome the defects. In addition to the decrease in the amount of enzyme, the bAla-79-->Lys mutation affected ATP synthesis to a much greater extent than ATP-driven proton translocation. The evidence supports our earlier hypothesis, in which bAla-79 was proposed to play an important, but not essential, structural role in F1F0 ATP synthase assembly or stability.

Behavioral management strategies for urinary incontinence

Behavioral interventions are recommended by Agency for Health Care Policy and Research Clinical Guideline as the first line of treatment for most types of urinary incontinence. This article defines and briefly describes the six behavioral treatment techniques and discusses the research base for the efficacy of each type of intervention. Caveats and needed research are also presented.

Clinical practice guidelines. The Agency for Health Care Policy and Research fosters the development of evidence-based guidelines

As medical technology increases rapidly and becomes more complex, clinical practice guidelines can help healthcare providers assess current practices and integrate technological advances. Through the Agency for Health Care Policy and Research (AHCPR), the federal government has begun to facilitate the development of clinical practice guidelines. Expert or contract panels, authorized by the AHCPR, develop guidelines on specific clinical conditions. The AHCPR guideline methodology is designed to produce evidence-based guidelines that are valid, clinically applicable, and clinically flexible. Each panel spends a year or more developing the guideline, beginning with an extensive literature search and review. The panel prepares evidence tables, statistically analyzes aggregate data (where appropriate), conducts harm and benefit analyses, and prepares health policy analyses (or cost-impact studies). During this process, the panel holds an open forum to solicit comments on the guideline topic. After this public discussion, the panel prepares a final draft of the guideline. Several hundred individuals review the guideline. Some policymakers believe clinical practice guidelines can lead to better healthcare outcomes. Guidelines can provide information in a useful format for clinicians to use at the bedside or the point of decision making in patient care. Guidelines also provide information that can be used in continuing education and professional education programs.

Urinary incontinence: an augmented prompted void approach

Continence improves from 44.7% dryness at baseline to 54.7% at the end of treatment, an improvement of 22%, or about one incontinent episode per day. Urinary incontinence is improved in cognitively impaired residents by augmenting the prompted voiding procedure with a bellpad. Bladder behavior changes with behavioral treatment strategies, because the volume voided into an appropriate receptacle increased an average of 26 mL per 2 hours. Reimbursement policies should not exclude treatment of the severely cognitively impaired nor the immobile in nursing homes.

Assessing toileting skills and habits in an adult day care center

In a structured assessment of mobility and toileting skills, all the continent clients but only 46.2% of incontinent clients were able to toilet themselves, even with verbal and physical guidance. Unobtrusive observation of toileting habits indicated that incontinent clients used the toilet less often than continent clients and used more staff assistance to do so. On mental status examination, incontinent clients scored significantly lower than continent clients. Incontinence in this population is a multidimensional disorder in which physical disability is a predominant factor.

Targeted mutagenesis of the b subunit of F1F0 ATP synthase in Escherichia coli: Glu-77 through Gln-85

Subunit b of Escherichia coli F1F0 ATP synthase contains a large hydrophilic region thought to be involved in the interaction between F1 and F0. Oligonucleotide-directed mutagenesis was used to evaluate the functional importance of a segment of this region from Glu-77 through Gln-85. The mutagenesis procedure employed a phagemid DNA template and a doped oligonucleotide primer designed to generate a predetermined collection of missense mutations in the target segment. Sixty-one mutant phagemids were identified and shown to contain nucleotide substitutions encoding 37 novel missense mutations. Mutations were isolated singly or in combinations of up to four mutations per recombinant phagemid. F1F0 ATP synthase function was studied by mutant phagemid complementation of a novel E. coli strain in which the uncF (b) gene was deleted. Complementation was assessed by observing growth on solid succinate minimal medium. Many phagemid-encoded uncF (b) gene mutations in the targeted segment resulted in growth phenotypes indistinguishable from those of strains expressing the native b subunit, suggesting abundant F1F0 ATP synthase activity. In contrast, several specific mutations were associated with a loss of enzyme function. Phagemids specifying the Ala-79----Pro, Arg-82----Pro, Arg-83----Pro, or Gln-85----Pro mutation failed to complement uncF (b) gene-deficient E. coli. F1F0 ATP synthase displayed the greatest sensitivity to mutations altering a single site in the target segment, Ala-79. The evidence suggests that Ala-79 occupies a restricted position in the enzyme complex.

Effect of postural stress on left ventricular performance using the continuous-wave Doppler technique

To evaluate the effect of postural shifts on continuous-wave Doppler indices of left ventricular performance in normal man, we recorded Doppler signals suprasternally in 69 healthy volunteers, ranging in age from 20 to 86 years, in the supine position and 2 min after assumption of sitting and standing postures. All indices decreased progressively with increasing orthostasis: peak acceleration (PKA): 15.6 +/- 4.5 m/s2 to 14.0 +/- 4.0 m/s2 to 13.6 +/- 4.6 m/s2; peak velocity (PKV): 0.64 +/- 0.18 m/s to 0.58 +/- 0.17 m/s to 0.56 +/- 0.17 m/s; stroke distance (SD): 11.4 +/- 3.7 cm to 9.8 +/- 3.4 cm to 8.0 +/- 2.8 cm; SD x heart rate (VIH): 717 +/- 272 cm to 655 +/- 268 cm to 572 +/- 217 cm, from supine to sitting to standing, respectively (p less than 0.001). In contrast heart rate increased modestly from 62.4 +/- 10.0 bpm supine, to 66.9 +/- 12.4 bpm sitting, to 71.3 +/- 9.9 bpm standing (p less than .001). Similar postural changes in Doppler variables were seen in all three age groups (20 to 44 years; 45 to 64 years; and 65 to 86 years). Thus, orthostasis in normal subjects is accompanied by a reduction in all continuous-wave Doppler indices of left ventricular performance, regardless of age.

Future data needs for quality of care monitoring, DRG considerations, reimbursement and outcome measurement

For nurses and vendors, the challenge to achieve a useful automated record involves becoming participants in the organizations defining the nursing component of the medical record. The development of systems that monitor costs, quality and access are means to better support nurses and other health professionals.

Evaluation of UNIS: Urological Nursing Information Systems

Unis is a nurse expert system prototype specifically designed to assist nurses caring for elderly, incontinent patients residing in nursing homes. Two studies measuring the performance level of UNIS were implemented. In the first study, results of sessions with UNIS on case studies of elderly, incontinent patients were compared to sessions with nurse experts. The relevance of questions, value of recommendations and overall performance were rated by an evaluation panel. In the second study, UNIS was implemented on two nursing units in a nursing home. The number of wet occurrences of patients residing on units where UNIS was consulted by nurses was compared to the number of wet occurrences of patients residing on units where UNIS was not consulted by nurses. The knowledge of urinary incontinence of nurses who consulted UNIS and those who did not consult UNIS were also compared. The results indicate that when judged by an evaluation panel, the relevance of the questions and value of the recommendations generated by UNIS were not rated significantly different than ratings assigned to nurse experts consulting on the same case studies. There was a significant difference between assigned ratings for overall performance; F.01 (4,16) = 10.4. UNIS scored the highest on four out of five case studies. In the second study, the number of wet occurrences of patients residing on units where nurses consulted UNIS decreased significantly; F.01 (2,9) = 34.67. The knowledge of urinary incontinence also improved significantly when nurses' consulted UNIS; F.001 (2,157) = 19.46. The methods and results of these two studies are presented.

Cost-effectiveness of treating incontinence in severely mobility-impaired long term care residents

Severely mobility-impaired residents in long term care facilities are usually incontinent. The incontinence and immobility predispose this group to decubitus ulcers and urinary tract infections that have been described as adding to the "consequence costs of incontinence" of $80 million per year. In this quasi-experimental study of ten subjects, a mechanical lift (Clinilift) was used with a two-hour schedule to improve incontinence. Subjects showed improvement in not only dryness but also volume of urine voided and the frequency of decubitus ulcers and UTIs. Because this incontinence treatment is labor intensive, the costs of treating incontinence increased by $2.90 over the cost of providing incontinent care. When the costs of decubitus ulcers and urinary tract infections are considered, however, the treatment savings were $13.38 per patient per day.

Do nurses consistently document incontinence?

1. Urinary incontinence is inconsistently documented on medical records of nursing home residents. 2. Documentation of urinary incontinence by professional nurses may be improved by changes in organizational factors such as staffing, policy implementation, and staff education. 3. Forms that employ cue words for eliminative status show more documentation of continence status than forms that have an open format. 4. Evaluation of changes in nursing practice in the nursing home setting can benefit from nursing studies that employ an organizational perspective.

Nursing management of urinary incontinence in geriatric inpatients

The management and treatment of incontinence represent two interrelated areas--providing enough providers of care and describing the types of management and treatment options available to the incontinent patient. This article has stressed that adequate staffing underlies any successful program of continence management and treatment. In addition, many options for the management and treatment of incontinence in the elderly have been presented. Of importance are the specific nursing implications that will make many continence protocols successful. These guidelines can provide the basis for planning patient care through the nursing process. This article has also addressed management and treatment strategies for incontinence that not only improve incontinence in patients but may cure it. These include behavioral management strategies which nurses should be encouraged to use in treating incontinent patients in the community. These same behavioral management strategies are being studied in inpatient settings, and the results indicate that nurses in inpatient settings and long-term care facilities should implement behavioral treatment programs for incontinent patients.