Temperature-sensitive forms of large and small invertase in a mutant derived from a SUC1 strain of Saccharomyces cerevisiae.

Mutagenesis of the sucrose-fermenting (SUC1) Saccharomyces cerevisiae strain 4059-358D yielded an invertase-negative mutant (D10). Subsequent mutagenic treatment of D10 gave a sucrose-fermenting revertant (D10-ER1) that contained the same amount of large (mannoprotein) invertase as strain 4059-358D but only trace amounts of the smaller intracellular nonglycosylated enzyme. Limited genetic evidence indicated that the mutations in D10 and D10-ER1 are allelic to the SUC1 gene. The large invertases from D10-ER1 and 4059-358D were purified and compared. The two enzymes have similar specific activity and Km for sucrose, cross-react immunologically, and show the same subunit molecular weight after removal of the carbohydrate with endo-beta-N-acetylglucosaminidae H. They differ in that the large enzyme from the revertant is rapidly inactivated at 55 degrees C, whereas that from the parent is relatively stable at 65 degrees C. The small invertase in extracts of D10-ER1 is also heat sensitive as compared to the small enzyme from the original parent strain. The low level of small invertase in mutant D10-ER1 may reflect increased intracellular degradation of this heat-labile form. In several crosses of D10-ER1 with strains carrying the SUC1 or SUC3 genes, the temperature sensitivity of the large and small invertases and the low cellular level of small invertase appeared to cosegregate. These findings are evidence that SUC1 is a structural gene for invertase and that both large and small forms are encoded by a single gene. A detailed genetic analysis is presented in a companion paper.

The effectiveness of one-on-one nurse education on the outcomes of high-risk adult and pediatric patients with asthma.

The effects of an asthma self-management program on asthma outcomes were evaluated in adult and pediatric patients with asthma who were considered at high risk (i.e., those who were not in control of their disease as determined by resource utilization, medication use, or lack of use). The program consisted of one-on-one nurse-to-patient ("nurse champion") education and subsequent assessment of asthma outcomes using the Asthma Quality Assessment System (AQAS) questionnaire, which measured asthma severity, patient quality of life, asthma awareness and knowledge, confidence in managing asthma, use of peak flow meters, asthma symptoms, medication use, lost work or school days, and affect of asthma. Over the course of six months, nurse champions educated 201 patients from four managed care plans and collected data at baseline and during four follow-up sessions. Adult patients and pediatric patient caregivers reported significant improvements in quality of life, and clinical and process measures. Significant increases in asthma knowledge were observed immediately after patient education, including greater than 89% increase in the proportion of patients who reported that they know "a lot" about the "things that cause asthma symptoms." Significant decreases were also found in work or school days missed, urgent care utilization, and hospital admission rates. Appropriate preventive care visits increased by more than 40%. These results indicate that the nurse champion program was associated with an improvement in asthma outcomes in high-risk adult and pediatric patients and warrant further evaluation in controlled studies. Incorporating one-on-one education programs into asthma management is an effective and rapid means of improving asthma outcomes.

How nurses perceive medication errors.

It is widely believed that the number of medication errors reported at each hospital represents only the tip of the iceberg. The reported data rarely address issues beyond the number of incidents that occur. A study conducted at an urban community hospital found that medication errors are under-reported and that nurses view medication errors as multiple cause incidents.

Genetic control of invertase formation in Saccharomyces cerevisiae. I. Isolation and characterization of mutants affecting sucrose utilization.

Nine sucrose nonfermenting mutants have been isolated from yeast strain EK-6B, carrying the tightly linked SUC3 and MAL3 genes. These mutants are allelic to the SUC3 gene recessive in nature and none of them has detectable levels of either internal or external invertase. A single point mutation leading to the loss of both invertases suggests that either SUC3 is a control gene or codes for a polypeptide which is shared by both invertases.

[Rare medicinal mercury poisoning]. / Eine seltene medizinale Quecksilber-Vergiftung.

After an accidental injury of the bowel during a hysterectomy, the patients peritoneal cavity was irrigated for disinfection with a solution containing a mercury-compound. The patient died 40 days after this "peritoneal lavage" with a 0.2% solution of mercury-II-oxycanide. The disinfection with the toxic compound during operation can be judged as a medical mistreatment leading to death of the patient. The mercury concentration in blood (0.1 mg Hg per 100 g blood), taken during autopsy, exceeded normal values severalfold. The cause of death was diagnosed as a "multiorgan-failure", caused by an "iatrogenic mercury poisoning". The results of toxicological analysis, histological examination and the findings of autopsy are presented.

Genetic control of invertase formation in Saccharomyces cerevisiae. II. Isolation and characterization of mutants conferring invertase hyperproduction in strain EK-6B carrying the SUC3 gene.

Invertase formation in the yeast Saccharomyces cerevisiae is subject to repression by hexoses in the growth medium. Mutagen-induced (ethyl methanesulfonate or N-methyl-N-nitro-nitrosoguanidine) invertase hyperproducer mutants have been derived from the SUC3 MAL3 strain EK-6B by selecting for their ability to grow on media containing the sugar raffinose plus 2-deoxy-D-glucose (2DG). Raffinose like sucrose is a betta-fructoside which can be hydrolyzed by yeast invertase (beta-fructoside which can be hydrolyzed by yeast invertase (beta-fructofuranoside fructohydrolase). These mutants, designated dgr, produce higher levels of invertase (pi-glucosidase levels are also elevated but to a lesser extent) under conditions normally repressing invertase biosynthesis in the parent. Invertases of mutants dgr2 and dgr3 are indistinguishable from that of EK-6B with respect to their Km's for sucrose and thermal labilities. Genetic studies revealed that dgr2 and dgr3 are recessive and unlinked to the SUC3 gene.

High-average-power dye laser at Lawrence Livermore National Laboratory.

The copper-laser-pumped dye laser system developed at the Lawrence Livermore National Laboratory (LLNL) is now capable of sustained, efficient, and reliable operation at total powers exceeding 2500 W and single amplifier chain powers exceeding 1300 W. Wavelength center frequency stability is maintainable to < 50 MHz. Laser dyes developed at LLNL permit tunability from 550 to 650 nm. Wave-front quality is < lambda/4 peak to valley. The system is operated remotely with the aid of a comprehensive set of diagnostics. Besides supporting its primary atomic-vapor-laser-isotope-separation mission, the system is being used in alternate applications such as materials processing and the generation of artificial guide stars.

Relationship of large and small invertases in Saccharomyces: mutant selectively deficient in small invertase.

A mutant strain of Saccharomyces cerevisiae (D10-ER1) has been isolated after a two-step mutagenesis of strain 4059-358D (SUC 1) using ethyl methane sulfonate. Cells of this new strain produced a level of total invertase equaling that of 4059 but contained only trace amounts of the small, internal, aglycan form of the enzyme (less than 0.1% of total in D10-ER1 compared with 6% in 4059). When D10.ER1 was crossed with an invertase-hyperproducing strain dgr3 (SUC3), progeny were isolated (HZ400-5A and HZ400-2C) in which levels of total invertase had at least quadrupled. The percentage of small invertase, however, remained insignificant. Levels of small invertase in strain HZ400-5A were determined by affinity chromatography on conconavalin A-Sepharose, gel permeation chromatography, and isopycnic centrifugation in CsCl. The large invertase of the SUC1 yeasts described here was found to contain a form apparently greater in size than the large invertase of the SUC2 strain FH4C; this probably reflects a higher content of carbohydrate. The overall results of this study do not support a direct structural relationship between large and small invertases. The implications on invertase biosynthesis and structure are discussed.