Comprehensive mutational analysis of yeast DEXD/H box RNA helicases involved in large ribosomal subunit biogenesis.

DEXD/H box putative RNA helicases are required for pre-rRNA processing in Saccharomyces cerevisiae, although their exact roles and substrates are unknown. To characterize the significance of the conserved motifs for helicase function, a series of five mutations were created in each of the eight essential RNA helicases (Has1, Dbp6, Dbp10, Mak5, Mtr4, Drs1, Spb4, and Dbp9) involved in 60S ribosomal subunit biogenesis. Each mutant helicase was screened for the ability to confer dominant negative growth defects and for functional complementation. Different mutations showed different degrees of growth inhibition among the helicases, suggesting that the conserved regions do not function identically in vivo. Mutations in motif I and motif II (the DEXD/H box) often conferred dominant negative growth defects, indicating that these mutations do not interfere with substrate binding. In addition, mutations in the putative unwinding domains (motif III) demonstrated that conserved amino acids are often not essential for function. Northern analysis of steady-state RNA from strains expressing mutant helicases showed that the dominant negative mutations also altered pre-rRNA processing. Coimmunoprecipitation experiments indicated that some RNA helicases associated with each other. In addition, we found that yeasts disrupted in expression of the two nonessential RNA helicases, Dbp3 and Dbp7, grew worse than when either one alone was disrupted.

What can we learn from patient dissatisfaction? An analysis of dissatisfying events at an academic medical center.

BACKGROUND: Patient satisfaction is typically measured by quantitative surveys using predetermined domains. However, dissatisfaction may be an entity distinct from satisfaction, may have different determinants, and may better reflect problems in healthcare delivery. OBJECTIVE: The aim of this study was to describe domains of dissatisfaction experienced by patients during hospitalization. SETTING: The setting was a U.S. urban academic medical center. PATIENTS: The patients were adults discharged between July 1, 2007 and June 30, 2008 INTERVENTION: The intervention was a postdischarge telephone interview: "If there was one thing we could have done to improve your experience in the hospital, what would it have been?" MEASUREMENTS: The measurements were standard qualitative analysis of suggestions for improvement. RESULTS: We randomly selected 976 of 9,764 interviews. A total of 439/976 (45.0%) included at least one suggestion for improvement. We identified six major domains of dissatisfaction: ineptitude (7.7%), disrespect (6.1%), waits (15.8%), ineffective communication (7.4%), lack of environmental control (15.6%), and substandard amenities (6.9%). These domains corresponded to six implicit expectations for quality hospital care: safety, treatment with respect and dignity, minimized wait times, effective communication, control over physical surroundings, and high-quality amenities. Some of these expectations, such as for safe care, effective communication between providers, and lack of disrespect, may not be adequately captured in existing patient satisfaction assessments. CONCLUSIONS: The results represent patient-generated priorities for quality improvement in healthcare. These priorities are not all consistently represented in standard patient satisfaction surveys and quality improvement initiatives. Patient input is critical to assessing the quality of hospital care and to identifying areas for improvement.

Effect of 4-(5-chloro-2-hydroxyphenyl)-3-(2-hydroxyethyl)-6-(trifluoromethyl)-quinolin-2(1H)-one (BMS-223131), a novel opener of large conductance Ca2+-activated K+ (maxi-K) channels on normal and stress-aggravated colonic motility and visceral nociception.

We evaluated the effects of 4-(5-chloro-2-hydroxyphenyl)-3-(2-hydroxyethyl)-6-(trifluoromethyl)-quinolin-2(1H)-one (BMS-223131), an opener of large conductance Ca(2+)-activated potassium (maxi-K) channels, on normal and stress-exacerbated colonic motility and visceral nociception in the rat. Fecal output was employed as an index of motility. Visceral nociception, in response to intracolonic balloon distension (10-90 mm Hg; 30 s duration), was evaluated using one of three indices: change in blood pressure, abdominal withdrawal, or myoelectrical activity. BMS-223131 (2, 6, or 20 mg/kg i.p.) produced a small but dose-dependent and significant reduction in cumulative 24-h fecal output. Fecal output in response to stress (1-h restraint plus bursts of air to the face) was markedly inhibited by BMS-223131, and moisture content was significantly reduced. With regard to visceral pain, the transient and distention-dependent reduction in arterial pressure in anesthetized animals was inhibited by BMS-223131 in a dose-dependent manner. Distension-induced abdominal withdrawal in conscious rats was also dose-dependently attenuated by BMS-223131. BMS-223131 at a dose of 20 mg/kg markedly attenuated the increase in myoelectrical activity evoked by balloon distention in conscious animals. BMS-223131 was also evaluated in viscerally hypersensitive rats (sensitized as neonates by intracolonic mustard oil) where it produced a robust dose-dependent attenuation of the abdominal withdrawal response. Compared with naive animals, BMS-223131 was more potent in the sensitized animals. Thus, BMS-223131 effectively reduced stress-induced colonic motility and visceral nociception supporting the potential utility of maxi-K channel openers for the treatment of bowel disorders involving dysfunctional motility and visceral sensitivity.