Corn silage management I: effects of hybrid, maturity, and mechanical processing on chemical and physical characteristics

Two experiments were conducted to evaluate the effects of hybrid, maturity, and mechanical processing of whole plant corn on chemical and physical characteristics, particle size, pack density, and dry matter recovery. In the first experiment, hybrid 3845 whole plant corn was harvested at hard dough, one-third milkline, and two-thirds milkline with a theoretical length-of-cut of 6.4 mm. In the second experiment, hybrids 3845 and Quanta were harvested at one-third milkline, two-thirds milkline, and blackline stages of maturity with a theoretical length-of-cut of 12.7 mm. At each stage of maturity, corn was harvested with and without mechanical processing by using a John Deere 5830 harvester with an onboard kernel processor. The percentage of intact corn kernels present in unprocessed corn silage explained 62% of variation in total tract starch digestibility. As the amount of intact kernels increased, total tract starch digestibility decreased. Post-ensiled vitreousness of corn kernels within the corn silage explained 31 and 48% of the variation of total tract starch digestibility for processed and unprocessed treatments, respectively. For a given amount of vitreous starch in corn kernels, total tract starch digestibility was lower for cows fed unprocessed corn silage compared with processed corn silage. This suggests that processing corn silage disrupts the dense protein matrix within the corn kernel where starch is embedded, therefore making the starch more available for digestion. Particle size of corn silage and orts that contained corn silage was reduced when it was processed. Wet pack density was greater for processed compared with unprocessed corn silage.

Differential effects of hyperlipidemia on insulin secretion in islets of langerhans from hyperglycemic versus normoglycemic rats

Chronic elevations in plasma levels of fatty acids (FAs) adversely affect pancreatic beta-cell function in type 2 diabetes. In vitro, we have previously shown that deleterious effects of prolonged exposure of isolated islets to FAs were dependent on the presence of elevated glucose concentration. This led us to hypothesize that both hyperlipidemia and hyperglycemia must be present simultaneously for FAs to affect beta-cell function. To test this hypothesis in vivo, we administered a high-fat diet for 6 weeks to Goto-Kakizaki (GK) rats. High-fat feeding had no effect on insulin secretion, insulin content, or insulin mRNA levels in islets from normoglycemic Wistar rats. In contrast, high-fat feeding markedly impaired glucose-induced insulin secretion in islets from GK rats. High-fat feeding did not affect triglyceride (TG) content or the rate of glucose oxidation in islets. It was, however, accompanied by a twofold increase in uncoupling protein (UCP)-2 levels in GK rat islets. Insulin treatment completely normalized glucose-induced insulin secretion and prevented the increase in UCP-2 expression in islets from high-fat-fed GK rats. We conclude that hyperlipidemia induced by high-fat feeding affects insulin secretion in islets from hyperglycemic GK rats only, by a mechanism which may involve, at least in part, modulation of UCP-2 expression.

Corn silage management: effects of maturity, inoculation, and mechanical processing on pack density and aerobic stability

Three experiments were conducted to evaluate the effects of inoculation, maturity, and mechanical processing of corn silage on aerobic stability and pack density. Corn silage was stored in 20-L mini silos for the three aerobic stability experiments. Corn silage was stored in 80-L mini silos for the three pack-density experiments. The wet pack density of corn silage tended to decrease as maturity advanced in all of the pack-density experiments, and processed corn silage had a greater wet pack density compared with unprocessed corn silage in two of the three 20-L mini silo experiments. Aerobic stability, measured as the number of hours to reach 1.7 degrees C above ambient, was greater for processed corn silage in two of the three 20-L mini silo experiments, and was greater for inoculated corn silage across the three 20-L mini silo experiments. Inoculation of corn silage with lactic acid producing bacteria tended to improve aerobic stability of corn silage more than maturity and mechanical processing.

Prolactin, interleukin-2 and FGF-2 stimulate expression, nuclear distribution and DNA-binding of rat homolog of pombe Cdc5 in Nb2 T lymphoma cells

Pombe and human Cdc5 have been implicated in G2/M progression, but recently Cdc5 was identified as a component of a multiprotein complex essential for pre-mRNA splicing. We have previously isolated a prolactin (PRL)-inducible partial cDNA (1907 bp) encoding rat Cdc5. In the present study, the full length rCdc5 sequence (2847 bp) was obtained by 5'-RACE and cytokine regulation of Cdc5 expression was examined. PRL and interleukin-2 (IL2) act as mitogens in Nb2 T-lymphoma cells. Fibroblast growth factor (FGF-2) is not mitogenic in Nb2 cells but inhibits apoptosis of PRL-deprived cells. This study showed that PRL, IL-2 and FGF-2 rapidly increased Nb2 Cdc5 expression (3.4 kb mRNA) to reach 2-3-fold above controls at 4 h, and Cdc5 mRNA levels remained elevated at 24 h. There was a corresponding 2-3-fold increase in Cdc5 protein (105 kDa) levels at 24 h. Immunoblotting and fluorescent confocal microscopy showed predominant nuclear/perinuclear Cdc5 in quiescent Nb2 cells. PRL or FGF-2 treatment transiently increased nuclear Cdc5-specific immunofluorescence at 4 h but IL-2 gave maximal nuclear accumulation of Cdc5 at 24 h. The deduced rCdc5 protein has approximately 98% amino acid identity with human Cdc5. Like other Cdc5 family members, the N-terminus of rCdc5 contains two repeats of a DNA-binding domain found in a-, b- and c-Myb. Gel shift assays using (32)P-labeled Myb consensus oligonucleotides revealed two Myb-specific DNA-protein complexes in Nb2 nuclear extracts. Formation of both complexes was increased by PRL or FGF-2 at 1-5 and at 20 h and was partially inhibited by anti-Myb or anti-Cdc5 antibodies. In summary, rapid activation of Cdc5 in response to mitogenic and non-mitogenic stimuli suggests a complex role for Cdc5 in cellular regulation and this may not be restricted to mitotic entry or G2/M progression as previously supposed.

Consumption of watercress fails to alter coumarin metabolism in humans

Watercress is an excellent source of phenethyl isothiocyanate (PEITC), an effective inhibitor of nitrosamine carcinogenesis in rodents. The mechanism of inhibition is believed to be due in part to inhibition of cytochrome P450 (P450) enzymes. P450 2A6 is a catalyst for the metabolic activation of several nitrosamines. In this study, we investigated the effect of watercress consumption on coumarin 7-hydroxylation, a P450 2A6-specific reaction, in a group of 15 nonsmoking, healthy volunteers. The urinary excretion of 7-hydroxycoumarin (7OHC) was determined. For 6 of the 15 subjects, watercress consumption decreased the amount of 7OHC excreted in the first 2 h following coumarin administration. However, the mean 0- to 2-h excretion of 7OHC for all 15 subjects was not significantly lowered by the consumption of watercress, 2.8 +/- 0.78 versus 3.1 +/- 0.53 mg (+/-S.D.). The mean 7OHC excreted from 2 to 4 h (1.1 +/- 0.50 mg) was significantly higher (P = 0.027) during watercress consumption than before (0.77 +/- 0.22 mg), suggesting a delay in coumarin metabolism. Total excretion of 7OHC was unaffected by watercress consumption. Therefore, under the conditions of our study, PEITC and other constituents of watercress had at most a marginal inhibitory effect on P450 2A6-catalyzed coumarin 7-hydroxylation.

Development of a nursing management practice atlas. Part 2, Variation in use of nursing and financial resources

Developing mechanisms for making benchmark comparisons among hospital organization is a challenge that has been embraced by nurse executives. A methodologic approach for ensuring data congruency when using available secondary data bases for making benchmark comparisons was detailed in part one (July/August) of this two-part series. This second article analyzes nursing management data using a set of nursing and financial resource variables identified by senior nurse executives of the hospital sites involved in this study.

Developing a nursing management practice atlas: Part 1, Methodological approaches to ensure data consistency

Challenges associated with the use of secondary data sources for benchmarking in nursing administration research are identified. A methodological approach for ensuring data consistency is presented in part one of this two-part series. Part two (September 2000) will provide an analysis of the nursing management data, based on a set of nursing and financial resource benchmarking variables identified by the senior nurse executives of these sites. Initial findings show evidence of data consistency across similar hospitals.

Estimation of the flow of microbial nitrogen to the duodenum using milk uric acid or allantoin

Data were collected from 10 experiments with duodenally cannulated Holstein dairy cows (271 combinations of cow and period) to evaluate the relationship between milk purine metabolites and microbial nitrogen flow. Experiments evaluated the effects of dietary factors on microbial N production and included: 1) supplemental sources of ruminally protected amino acids; 2) grass silage treated with fibrolytic enzymes; 3) bacterial inoculation of corn silage; 4) a comparison of corn and barley grain; 5) ruminal starch availability as affected by corn silages of varying maturity; and, 6) ruminal starch availability as affected by corn silages harvested at varying chop length and with or without mechanical processing. The coefficient of determination for individual experiments for the relationship between microbial nitrogen flow and allantoin or uric acid excretion in milk ranged from -0.01 to 0.77 and -0.06 to 0.22 respectively. Across all experiments, the coefficients of determination between microbial nitrogen flow and allantoin or uric acid excretion in milk were r2 = 0.09 and 0.01 respectively. Milk allantoin output was used to develop a prediction equation estimating microbial nitrogen flow to the duodenum. The greatest predictive value (r2 = 0.25) relationship was observed across non-bST experiments and included the factors of allantoin excretion, milk yield, dry matter intake, and days in milk. When milk yield was included in the model, the predictive value improved (r2 = 0.44). Based on these data, milk uric acid excretion alone cannot be used to predict microbial N production accurately [corrected].

Optimization of a fluoroscope to reduce radiation exposure in pediatric imaging

BACKGROUND

A new children's hospital provided the impetus to investigate radiation dose and image quality in a fluoroscope that was specially engineered for pediatric fluoroscopy. Radiation protection management recommends radiation exposures that are as low as reasonably achievable, while still maintaining diagnostic image quality.

OBJECTIVES

To obtain comparative phantom imaging data on radiation exposure and image quality from a newly installed fluoroscope before and after optimization for pediatric imaging.

MATERIALS AND METHODS

Images were acquired from various thickness phantoms, simulating differing patient sizes. The images were evaluated for visualization of high- and low-contrast objects and for radiation exposure. Effects due to use of the image intensifier anti-scatter grid were also investigated.

RESULTS

The optimization of the new fluoroscope for pediatric operation reduced radiation exposure by about 50% (compared to the originally installed fluoroscope), with very little loss of image quality. Pulsed fluoroscopy was able to lower radiation dose to less than 10% of continuous fluoroscopy, while still maintaining acceptable phantom image quality.

CONCLUSION

Radiation exposure in pediatric fluoroscopy can be reduced to values well below the exposure settings that are typically found on unoptimized fluoroscopes. Pulsed fluoroscopy is considered a requisite for optimal pediatric fluoroscopy.

Novobiocin-induced VP-16 accumulation and MRP expression in human leukemia and ovarian carcinoma cells

We have previously reported that novobiocin potentiates the cytotoxic activity of etoposide (VP-16) and teniposide (VM-26) in a number of experimental tumor cell lines by inhibition of the efflux of the epipodophyllotoxins by an ATP-requiring transporter. In leukemia cells from 12/19 patients and in ovarian carcinoma cells from 2/4 patients, novobiocin, in a concentration range of 150-1000 microM, increased the intracellular accumulation of VP-16 by 30-250% by inhibiting its efflux. Novobiocin did not significantly increase the intracellular concentration of VP-16 in human mononuclear bone marrow cells from two individuals with normal bone marrow, suggesting that it might be possible to selectively modulate the intracellular accumulation of the epipodophyllotoxin in tumor cells relative to normal hematopoietic tissue. Previous findings from our laboratory have provided evidence that the membrane transporter for VP-16 which is inhibited by novobiocin is distinct from the P-glycoprotein. The expression of MRP, measured by immunoblotting, was variable in novobiocin-responsive and non-responsive leukemia cells, indicating that no direct relationship existed between the modulatory activity of novobiocin on the transport of VP-16 and the expression of the MRP gene. The findings indicate that the novobiocin-sensitive VP-16 transporter is (i) present in high frequency in leukemia and ovarian carcinoma cells, and (ii) probably not the P-glycoprotein or MRP.

Diamino benzo[b]thiophene derivatives as a novel class of active site directed thrombin inhibitors. 5. Potency, efficacy, and pharmacokinetic properties of modified C-3 side chain derivatives

A systematic investigation of the structure-activity relationships of the C-3 side chain of the screening hit 1a led to the identification of the potent thrombin inhibitors 23c, 28c, and 31c. Their activities (1240, 903, and 1271 x 10(6) L/mol, respectively) represent 2200- and 2900-fold increases in potency over the starting lead 1a. This activity enhancement was accomplished with an increase of thrombin selectivity. The in vitro anticoagulant profiles of derivatives 28c and 31c were determined, and they compare favorably with the clinical agent H-R-1-[4aS, 8aS]perhydroisoquinolyl-prolyl-arginyl aldehyde (D-Piq-Pro-Arg-H; 32). The more potent members of this series have been studied in an arterial/venous shunt (AV shunt) model of thrombosis and were found to be efficacious in reducing clot formation. However, their efficacy is currently limited by their rapid and extensive distribution following administration.

Keratoconus with good unaided visual acuities: two case reports

BACKGROUND

Ophthalmic evaluation of patients with keratoconus (KC) often reveals highly myopic and irregular astigmatic refractive corrections. Irregular corneal astigmatism and central corneal scarring in patients with KC often result in a loss of best-corrected spectacle acuity. Rigid gaspermeable contact lenses generally optimize visual acuities for patients with KC.

CASE REPORTS

Two cases are discussed of patients who manifested clinically diagnosed KC but unusually good unaided Snellen visual acuities (20/25+ or better) in both eyes.

CONCLUSION

Good unaided visual acuities are not necessarily inconsistent with the diagnosis of KC.

Sleep disturbances in children with human immunodeficiency virus infection

OBJECTIVE

To describe the sleep patterns and level of fatigue in children and adolescents (6-18 years of age) with HIV infection, compared with ethnic-, gender-, and age-matched healthy children in the home setting.

DESIGN

Descriptive, comparative.

SETTING

Conducted in each child's home environment.

STUDY PARTICIPANTS

Eighteen HIV-infected and 15 noninfected children completed the study. The Centers for Disease Control and Prevention HIV classifications for the 18 HIV-infected children were: A (n = 7), B (n = 6), and C (n = 5).

METHODS

A symptom diary was developed using a previously validated fatigue assessment scale, modified for use with children. Content validity of the diary was established with a panel of 5 experts in child development and pediatric HIV disease. Children were asked to complete the diary each morning and evening for 3 days. Each child wore a wrist actigraph during the same period.

RESULTS

The HIV-infected children had significantly more wake time after sleep onset, compared with noninfected children (13.55% vs 7. 47%). The HIV-infected children had more awakenings (25.33 vs 16.71) and were awake for longer periods (3.01 vs 1.01 minutes), compared with noninfected children. By parent report, 7 HIV-infected children napped and 2 noninfected children napped, indicating greater daytime fatigue in the HIV-infected children. HIV-infected children also reported a greater level of evening tiredness (2.47 vs 1.8).

CONCLUSIONS

The findings from this study suggest that sleep disturbances occur in HIV-infected children, similar to findings previously described in HIV-infected adults. Additional research is necessary to characterize the nature and patterns of sleep disturbance and fatigue related to pediatric HIV-infection, to assess the impact these may have on daily activities, and to develop strategies to improve sleep for these children.

Characterization of multiple products of cytochrome P450 2A6-catalyzed cotinine metabolism

The primary metabolite of nicotine in smokers is cotinine. Cotinine is further metabolized to trans-3'-hydroxycotinine, the major urinary metabolite of nicotine in tobacco users. It was recently reported that cytochrome P450 2A6 catalyzes the conversion of cotinine to trans-3'-hydroxycotinine. In this work, we report that P450 2A6 metabolizes cotinine not only to trans-3'-hydroxycotinine but also to 5'-hydroxycotinine, norcotinine, and a fourth as yet unidentified metabolite. The products of baculovirus-expressed P450 2A6 [methyl-(3)H]cotinine metabolism were analyzed by radioflow HPLC. Three (3)H-labeled metabolites were detected and were present in approximately equal amounts. The identities of two of the metabolites were confirmed to be 5'-hydroxycotinine and trans-3'-hydroxycotinine by LC/MS/MS and LC/MS analysis and comparison to standards. The third product was not identified. A fourth product of P450 2A6-catalyzed cotinine metabolism was detected by LC/MS. It was identified by cochromatography with a standard and MS and MS/MS data to be norcotinine. An attempt was made to further characterize the unidentified (3)H-labeled metabolite by comparison to the cotinine metabolites generated by hamster liver microsomes. Hamster liver microsomes contain a P450, 2A8, which is closely related to P450 2A6, and have previously been shown to metabolize cotinine to three hydroxylated products, trans-3'-hydroxycotinine, 5'-hydroxycotinine, and N-(hydroxymethyl)norcotinine. We were unable to confirm that N-(hydroxymethyl)norcotinine was the unidentified cotinine metabolite generated by P450 2A6.

Dibasic benzo[b]thiophene derivatives as a novel class of active site directed thrombin inhibitors: 2. Sidechain optimization and demonstration of in vivo efficacy

Potent, subnanomolar thrombin inhibitors 4, 5, and 6 are developed through side chain optimization of novel, benzo[b]thiophene-based small organic entities 2 and 3 and through SAR additivity studies of the new structural elements identified. X-ray crystallographic studies of 4b-thrombin complex revealed a hydrophobic and an electrostatic interaction of these new elements with thrombin at the S2 and S3 binding sites. In vitro and in vivo pharmacological studies showed that 4, 5, and 6 are potent anticoagulants in human plasma with demonstrated antithrombotic efficacy in a rat model of thrombosis.

Pharmacology of LY315920/S-5920, [[3-(aminooxoacetyl)-2-ethyl-1- (phenylmethyl)-1H-indol-4-yl]oxy] acetate, a potent and selective secretory phospholipase A2 inhibitor: A new class of anti-inflammatory drugs, SPI

LY315920 is a potent, selective inhibitor of recombinant human, group IIA, nonpancreatic secretory PLA2 (sPLA2). In a chromogenic isolated enzyme assay, LY315920 inhibited sPLA2 activity with an IC50 of 9 +/- 1 nM or 7.3 x 10(-6) mole fraction, which approached the stiochiometric limit of this assay. The true potency of LY315920 was defined using a deoxycholate/phosphatidylcholine assay with a mole fraction of 1.5 x 10(-6). LY315920 was 40-fold less active against human, group IB, pancreatic sPLA2 and was inactive against cytosolic PLA2 and the constitutive and inducible forms of cyclooxygenase. Human sPLA2-induced release of thromboxane A2 (TXA2) from isolated guinea pig lung bronchoalveolar lavage cells was inhibited by LY315920 with an IC50 of 0.79 microM. The release of TXA2 from these cells by N-formyl-methionyl-leucyl-phenylalanine or arachidonic acid was not inhibited. The i.v. administration of LY315920, 5 min before harvesting the bronchoalveolar lavage cells, resulted in the inhibition of sPLA2-induced production of TXA2 with an ED50 of 16.1 mg/kg. Challenge of guinea pig lung pleural strips with sPLA2 produced contractile responses that were suppressed in a concentration-dependent manner by LY315920 with an apparent KB of 83 +/- 14 nM. Contractile responses induced by arachidonic acid were not altered. Intravenous or oral administration of LY315920 to transgenic mice expressing the human sPLA2 protein inhibited serum sPLA2 activity in a dose-related manner over a 4-h time course. LY315920 is a potent and selective sPLA2 inhibitor and represents a new class of anti-inflammatory agent designated SPI. This agent is currently undergoing clinical evaluation and should help to define the role of sPLA2 in various inflammatory disease states.

Estimation of the flow of microbial nitrogen to the duodenum using urinary uric acid or allantoin

Data were collected from six experiments using duodenally cannulated Holstein dairy cows (88 combinations of cow and period) to evaluate the relationship between urinary purine metabolites and microbial N flow. Experiments evaluated the effects of dietary factors on microbial N production, which included 1) varying concentrations of ruminally degradable protein and nonstructural carbohydrates, 2) supplemental sources of protected amino acids, 3) grass silage treated with fibrolytic enzymes, 4) bacterial inoculation of corn silage, and 5) ruminal starch availability as affected by corn silages of varying maturity. The coefficient of determination for individual experiments that measured the relationship between microbial N flow and allantoin or uric acid excretion in urine ranged from 0.01 to 0.68 and 0.02 to 0.82, respectively. Across all experiments, the coefficients of determination between microbial N flow and allantoin or uric acid excretion in urine were r2 = 0.002 and 0.11, respectively. Removal of data from one experiment improved the overall coefficient of determination between microbial N flow and urinary uric acid to r2 = 0.32. Urinary allantoin excretion across experiments was negatively correlated with microbial N flow, but urinary allantoin excretion within experiments was positively correlated with microbial N flow. Uric acid excretion in urine was positively correlated with microbial N flow across and within experiments, except for one experiment. Our data demonstrate that uric acid excretion in urine can be used to predict microbial N production, except in early lactation, and that urinary allantoin excretion cannot be used to predict microbial N production accurately among cows at different stages of lactation.

Indole inhibitors of human nonpancreatic secretory phospholipase A2. 3. Indole-3-glyoxamides

The preceding papers of this series detail the development of functionalized indole-3-acetamides as inhibitors of hnps-PLA2. We describe here the extension of the structure-activity relationship to include a series of indole-3-glyoxamide derivatives. Functionalized indole-3-glyoxamides with an acidic substituent appended to the 4- or 5-position of the indole ring were prepared and tested as inhibitors of hnps-PLA2. It was found that the indole-3-glyoxamides with a 4-oxyacetic acid substituent had optimal inhibitory activity. These inhibitors exhibited an improvement in potency over the best of the indole-3-acetamides, and LY315920 (6m) was selected for evaluation clinically as an hnps-PLA2 inhibitor.

Indole inhibitors of human nonpancreatic secretory phospholipase A2. 1. Indole-3-acetamides

Phospholipases (PLAs) produce rate-limiting precursors in the biosynthesis of various types of biologically active lipids involved in inflammatory processes. Increased levels of human nonpancreatic secretory phospholipase A2 (hnps-PLA2) have been detected in several pathological conditions. An inhibitor of this enzyme could have therapeutic utility. A broad screening program was carried out to identify chemical structures which could inhibit hnps-PLA2. One of the lead compounds generated by the screening program was 5-methoxy-2-methyl-1-(phenylmethyl)-1H-indole-3-acetic acid (13a). We describe the syntheses, structure--activity relationships, and pharmacological activities of a series of indole-3-acetamides and related compounds derived from this lead. This SAR was undertaken with the aid of X-ray crystal structures of complexes between the inhibitors and hnps-PLA2 which were of great value in directing the SAR.

Indole inhibitors of human nonpancreatic secretory phospholipase A2. 2. Indole-3-acetamides with additional functionality

As reported in our previous paper, a series of indole-3-acetamides which possessed potency and selectivity as inhibitors of human nonpancreatic secretory phospholipase A2(hnps-PLA2) was developed. The design of these compounds was based on information derived from x-ray crystal structures determined for complexes between the enzyme and its inhibitors. We describe here the further implementation of this structure-based design strategy and continued SAR development to produce indole-3-acetamides with additional functionalities which provide increased interaction with important residues within the enzyme active site. These efforts led to inhibitors with substantially enhanced potency and selectivity.

Evaluation of the Microbial Identification System for identification of clinically isolated yeasts

The Microbial Identification System (MIS; Microbial ID, Inc., Newark, Del.) was evaluated for the identification of 550 clinically isolated yeasts. The organisms evaluated were fresh clinical isolates identified by methods routinely used in our laboratory (API 20C and conventional methods) and included Candida albicans (n = 294), C. glabrata (n = 145), C. tropicalis (n = 58), C. parapsilosis (n = 33), and other yeasts (n = 20). In preparation for fatty acid analysis, yeasts were inoculated onto Sabouraud dextrose agar and incubated at 28 degrees C for 24 h. Yeasts were harvested, saponified, derivatized, and extracted, and fatty acid analysis was performed according to the manufacturer's instructions. Fatty acid profiles were analyzed, and computer identifications were made with the Yeast Clinical Library (database version 3.8). Of the 550 isolates tested, 374 (68.0%) were correctly identified to the species level, with 87 (15.8%) being incorrectly identified and 89 (16.2%) giving no identification. Repeat testing of isolates giving no identification resulted in an additional 18 isolates being correctly identified. This gave the MIS an overall identification rate of 71.3%. The most frequently misidentified yeast was C. glabrata, which was identified as Saccharomyces cerevisiae 32.4% of the time. On the basis of these results, the MIS, with its current database, does not appear suitable for the routine identification of clinically important yeasts.