Normal Room Light Research Articles

Phloxine B, a versatile bacterial stain

The data presented suggest that Phloxine B, a color additive for food, drugs, and cosmetics has a potential use as a nontoxic, faster (<2 min), inexpensive (350 tests for <1 cent material) and simpler to use alternative to Gram staining. Using Phloxine B staining it was possible to differentiate among gram-negative and gram-positive bacteria by visual determination under normal room lighting, light microscopy, fluorescence microscopy and confocal microscopy. This work demonstrated that Phloxine B can be used as a differential versatile bacterial stain and establishes a correlation between the staining properties of the dye and its bactericidal effect.

Phloxine B, a versatile bacterial stain

The data presented suggest that Phloxine B, a color additive for food, drugs, and cosmetics has a potential use as a nontoxic, faster (<2 min), inexpensive (350 tests for <1 cent material) and simpler to use alternative to Gram staining. Using Phloxine B staining it was possible to differentiate among Gram-negative and Gram-positive bacteria by visual determination under normal room lighting, light microscopy, fluorescence microscopy and confocal microscopy. This work demonstrated that Phloxine B can be used as a differential versatile bacterial stain and establishes a correlation between the staining properties of the dye and its bactericidal effect.

Allocentric cues do not always improve whole body reaching performance

The aim of this investigation was to gain further insight into control strategies used for whole body reaching tasks. Subjects were requested to step and reach to remembered target locations in normal room lighting (LIGHT) and complete darkness (DARK) with their gaze directed toward or eccentric to the remembered target location. Targets were located centrally at three different heights. Eccentric anchors for gaze direction were located at target height and initial target distance, either 30 degrees to the right or 20 degrees to the left of target location. Control trials, where targets remained in place, and remembered target trials were randomly presented. We recorded movements of the hand, eye and head, while subjects stepped and reached to real or remembered target locations. Lateral, vertical and anterior-posterior (AP) hand errors and eye location, and gaze direction deviations were determined relative to control trials. Final hand location errors varied by target height, lighting condition and gaze eccentricity. Lower reaches in the DARK compared to the LIGHT condition were common, and when matched with a tendency to reach above the low target, help explain more accurate reaches for this target in darkness. Anchoring the gaze eccentrically reduced hand errors in the AP direction and increased errors in the lateral direction. These results could be explained by deviations in eye locations and gaze directions, which were deemed significant predictors of final reach errors, accounting for a 17-47% of final hand error variance. Results also confirmed a link between gaze deviations and hand and head displacements, suggesting that gaze direction is used as a common input for movement of the hand and body. Additional links between constant and variable eye deviations and hand errors were common for the AP direction but not for lateral or vertical directions. When combined with data regarding hand error predictions, we found that subjects' alterations in body movement in the AP direction were associated with AP adjustments in their reach, but final hand position adjustments were associated with gaze direction alterations for movements in the vertical and horizontal directions. These results support the hypothesis that gaze direction provides a control signal for hand and body movement and that this control signal is used for movement direction and not amplitude.

Low light and low ammonium are key factors for guayule leaf tissue shoot organogenesis and transformation

A new method has been developed for guayule tissue culture and transformation. Guayule leaf explants have a poor survival rate when placed on normal MS medium and under normal culture room light conditions. Low light and low ammonium treatment greatly improved shoot organogenesis and transformation from leaf tissues. Using this method, a 35S promoter driven BAR gene and an ubiquitin-3 promoter driven GUS gene (with intron) have been successfully introduced into guayule. These transgenic guayule plants were resistant to the herbicide ammonium-glufosinate and were positive to GUS staining. Molecular analysis showed the expected band and signal in all GUS positive transformants. The transformation efficiency with glufosinate selection ranged from 3 to 6%. Transformation with a pBIN19-based plasmid containing a NPTII gene and then selection with kanamycin also works well using this method. The ratio of kanamycin-resistant calli to total starting explants reached 50% in some experiments.

Compatibility of palonosetron with cyclophosphamide and with ifosfamide during simulated Y-site administration

The physical and chemical compatibility of palonosetron with cyclophosphamide and with ifosfamide during simulated Y-site administration was studied. Test samples were prepared in triplicate by mixing 7.5 mL of palonosetron hydrochloride 50 microg (of palonosetron) per milliliter with 7.5 mL of cyclophosphamide 10 mg/mL and with ifosfamide 20 mg/mL. Physical stability was assessed by turbidimetry, particle sizing, and visual inspection. Chemical stability was assessed by stability-indicating high-performance liquid chromatography. Evaluations were performed immediately and one and four hours after mixing. The samples were clear and colorless when viewed in normal fluorescent room light and when viewed with a high-intensity monodirectional light. Turbidity remained unchanged, and particulate content was low and exhibited little change. Palonosetron, cyclophosphamide, and ifosfamide remained chemically stable throughout the four-hour test period. Palonosetron hydrochloride was physically compatible with cyclophosphamide or ifosfamide during simulated Y-site administration.

Palonosetron HCl Compatibility and Stability with Doxorubicin HCl and Epirubicin HCl During Simulated Y-Site Administration

Palonosetron HCl is a selective 5-HT3 receptor antagonist used for the prevention of chemotherapy-induced nausea and vomiting. Palonosetron HCl may be administered with other drugs by Y-site administration, including doxorubicin HCI and epirubicin HCI. Consequently, stability and compatability information are needed to verify the acceptability of such Y-site administration. To evaluate the physical and chemical stability of undiluted palonosetron HCl 50 microg/mL with doxorubicin HCl 1 mg/mL and epirubicin HCl 0.5 mg/mL during simulated Y-site administration. Triplicate samples of palonosetron HCl with each of the anthracycline chemotherapy drugs were tested. Samples were stored and evaluated for up to 4 hours at room temperature near 23 degrees C. Physical stability was assessed using turbidimetric and particulate measurement, as well as visual inspection. Chemical stability was assessed by HPLC. All of the admixtures were clear and red-orange when viewed in normal fluorescent room light and with a Tyndall beam. Measured turbidity and particulate content were low initially and remained low throughout the study. The drug concentration was unchanged in any of the samples throughout the study. Palonosetron HCl is physically and chemically stable with doxorubicin HCl and epirubicin HCl during simulated Y-site administration of these drugs over 4 hours at ambient room temperature.

Physical and chemical stability of palonosetron HCl with cisplatin, carboplatin, and oxaliplatin during simulated Y-site administration

The objective of this study was to evaluate the physical and chemical stability of undiluted palonosetron HCl 50 mcg/mL with cisplatin 0.5 mg/mL, carboplatin 5 mg/mL, and with oxaliplatin 0.5 mg/mL in infusion solutions during simulated Y-site administration. Triplicate test samples were prepared by admixing 7.5 mL of palonosetron HCl with 7.5 mL of the cisplatin, carboplatin, and oxaliplatin dilutions. Physical stability was assessed using a multistep evaluation procedure that included both turbidimetric and particulate measurement as well as visual inspection. Chemical stability was assessed using stability-indicating HPLC analytical techniques based on the determination of drug concentrations. Evaluations were performed initially upon mixing and 1 and 4 hours after mixing. The samples were clear and colourless when viewed in normal fluorescent room light and when viewed with a Tyndall beam. Measured turbidity remained unchanged and particulate content was low and exhibited little change. HPLC analysis found palonosetron HCl, cisplatin, carboplatin, and oxaliplatin remained stable throughout the 4-hour test with no drug loss. Palonosetron HCl is physically compatible and chemically stable with cisplatin, carboplatin, and oxaliplatin during Y-site administration.

Bromination of tri(isopropyl)boroxine and asymmetric synthesis of (2-cyano-3,3-dimethylcyclopropyl)boronic esters

Bromination of triisopropylboroxine to tris(1-bromo-1-methylethyl)boroxine is far more facile than α-bromination of sec-alkylboronic esters. Normal fluorescent room light is sufficient to initiate the free radical reaction, which can be carried out as a titration. The steric environment for replacement of the bromine by lithioacetonitrile and subsequent asymmetric insertion of a chloromethyl group into the carbonboron bond is more highly hindered than what has been studied previously, and the pinanediol ester proved to be the only useful chiral boronic ester in such circumstances. Cyclization of the cyano-substituted boronic ester to the corresponding cyclopropylboronic ester yielded a mixture of diastereomers, presumably the result of base-induced epimerization of the initially formed major isomer having the boronic ester and cyano groups trans.

Stability of cefepime hydrochloride in AutoDose Infusion System bags.

To evaluate the physical and chemical stability of cefepime (as the hydrochloride) 1 g/100 mL and 4 g/100 mL admixed in NaCl 0.9% injection and packaged in AutoDose Infusion System bags. Triplicate test samples of cefepime hydrochloride in NaCl 0.9% injection were packaged in ethylene vinyl acetate plastic containers, AutoDose bags, designed for use in the AutoDose Infusion System. Samples were stored protected from light and evaluated at appropriate intervals for up to 7 days at room temperature of approximately 23 degrees C and 30 days under refrigeration at 4 degrees C. Physical stability was assessed using turbidimetric and particulate measurement, as well as visual inspection. Chemical stability was assessed by HPLC. All of the admixtures were initially clear and light yellow when viewed in normal fluorescent room light and with a Tyndall beam. Measured turbidity and particulate content were low initially but increased over time, eventually becoming a yellow or orange precipitate. The higher concentration precipitated earlier; refrigeration slowed precipitation for both test concentrations. HPLC analysis found that the 1-g/100 mL concentration maintained adequate stability for 2 days at 23 degrees C and up to 30 days at 4 degrees C. The 4-g/100 mL concentration maintained adequate stability for 1 day at room temperature and 7 days under refrigeration; however, unacceptable drug loss and precipitation developed after those time points. Cefepime hydrochloride exhibited physical and chemical stability consistent with previous stability studies. The AutoDose Infusion System bags were not found to affect adversely the physical and chemical stability of this drug.

Light-induced Resistance of the Keratin Network to the Filament-disrupting Tyrosine Phosphatase Inhibitor Orthovanadate

Epidermal keratinocytes respond to low-dose light irradiation by inducing signaling cascades that lead to long-term effects on gene transcription thereby protecting cells against damage. In contrast, little is known about immediate light-induced alterations of structural proteins. We have made the intriguing observation that light produces fundamental changes in the properties of the keratin filament system of cultured epidermoid A-431 cells. A short light exposure (1-10 min) causes the keratin cytoskeleton to become immediately resistant to the tyrosine phosphatase inhibitor orthovanadate, which otherwise disrupts the keratin filament network completely in just a few minutes. This protective effect is inducible throughout the entire visible spectrum and is elicited by normal room light (<200 Lux). Exposure of cells to monochromatic light of various wavelengths is therefore equally effective. In addition, the acquisition of orthovanadate resistance has been directly monitored in living cells; a partially disrupted keratin cytoskeleton recovers to a completely filamentous network in half an hour. Finally, the protective light effect is largely reversed in 2 h and can be mimicked by preincubation with the p38 kinase inhibitor SB203580. In contrast, the mitogen-activated protein kinase inhibitor PD98059 and epidermal growth factor inhibit orthovanadate action to a lesser extent. Taken together, these observations suggest a stabilizing function of light on the keratin filament network; this may be of relevance to the treatment of skin diseases with reduced keratin stability.

Stability of Imipenem-Cilastatin Sodium in AutoDose Infusion System Bags

The objective of this study was to evaluate the physical and chemical stability of imipenem-cilastatin sodium 250 mg/100 mL and 500 mg/100 mL (of each drug component) admixed in 0.9% sodium chloride injection packaged in AutoDose Infusion System bags. Triplicate test samples were prepared by bringing the required amount of imipenem-cilastatin sodium injection to volume with 0.9% sodium chloride injection. A total of 100 mL of each of the test solutions was packaged in each of three ethylene vinyl acetate (EVA) AutoDose bags designed for use in the AutoDose Infusion System for each storage condition. Samples were protected from light and evaluated at appropriate intervals for up to three days at 23°C and 14 days at 4°C. Physical stability was assessed using a multistep evaluation procedure that included turbidimetric and particulate measurement in addition to visual inspection. Chemical stability was assessed with stability-indicating high performance liquid chromatography (HPLC) analytical techniques, based on initial drug concentrations and concentrations at appropriate intervals over the study periods. The admixtures were clear throughout the study when viewed in normal fluorescent room light and with a Tyndall beam. Measured turbidity and particulate content were low initially and exhibited little change throughout the study. HPLC analysis revealed extensive decomposition in the samples, with imipenem being the less stable component. The instability of the imipenem-cilastatin sodium admixtures is consistent with previous studies. Admixtures stored under refrigeration should be used immediately upon warming to room temperature due to the rapid rate of imipenem decomposition. The AutoDose Infusion System bags were not found to affect adversely or improve the physical and chemical stability of this drug.

Stability of methylprednisolone sodium succinate in autodose infusion system bags.

To evaluate the physical and chemical stabilities of methylprednisolone sodium succinate solutions packaged in sterile AutoDose Infusion System bags. Laboratory. The test samples were prepared by reconstituting the methylprednisolone sodium succinate, adding the required amount of drug to the AutoDose Infusion System bags, and diluting to the target concentrations of 100 mg/100 mL and 1 gram/100 mL with 0.9% Sodium Chloride Injection. Physical stability and chemical stability based on drug concentrations initially and at appropriate intervals over periods up to 3 days at 23 degrees C and 30 days at 4 degrees C. The admixtures initially were clear when viewed in normal fluorescent room light and with a Tyndall beam. Measured turbidity and particulate content were low initially and exhibited little change. All samples were essentially colorless throughout the study. High-performance liquid chromatography analysis revealed some decomposition in the samples. Methylprednisolone sodium succinate exhibited about 8% loss after 2 days and about 13% loss after 3 days at 23 degrees C. In the samples stored at 4 degrees C, methylprednisolone sodium succinate exhibited acceptable stability through 21 days of storage, but losses exceeded 10% after 30 days. Methylprednisolone sodium succinate exhibited physical and chemical stabilities consistent with those found in previous studies. The AutoDose Infusion System bags did not adversely affect the physical or chemical stability of this drug.

The growth andproperties of GaN:As layers prepared by plasma-assistedmolecular beam epitaxy

We have studied the growth and properties of GaN:As layersprepared by molecular beam epitaxy, using a plasma source foractive nitrogen. We have demonstrated that arsenic dopingduring growth produces films showing blue emission at roomtemperature. The blue emission is centred at 2.6 eV and is morethan a decade stronger than the band edge emission. The filmsare predominantly wurtzite, but with a small cubic contentwhich exists mainly close to the substrate-epilayer interface.We have investigated the influence of growth conditions on theintensity of this blue emission. In films grown under optimumconditions, the blue emission is strong enough to be clearlyvisible under normal room lighting. We have also discussed the transition from As-doped GaN showing blue emission to theformation of GaN1-xAsx alloys. We have determinedthat for a fixed arsenic flux, increasing the N/Ga ratio leadsto the formation of alloy films. Our results suggest that thismaterials system may have potential applications in electronicand opto-electronic devices.

Strong blue emission from GaN isoelectronically doped with arsenic

We have shown that for GaN films grown by molecular beam epitaxy, strong blue emission is observed for samples isoelectronically doped with arsenic. This blue emission is very strong and can be observed at room temperature in normal room lighting and is more than one order of magnitude stronger than the band edge emission in regular GaN films. The films were grown on sapphire substrates by plasma-assisted molecular beam epitaxy, using both As 2 and As 4. In this paper we present detailed studies of the influence of the growth conditions including the arsenic flux, the group V:III ratio and substrate temperature on the intensity of the blue emission from arsenic doped GaN. This work suggests that GaNAs may potentially be a replacement for InGaN alloys in optical device applications.

Stability of Ciprofloxacin and Vancomycin Hydrochloride in AutoDose Infusion System Bags

The objective of this study was to evaluate the physical and chemical stability of ciprofloxacin 400 mg/100 mL and vancomycin as the hydrochloride 1 g/100 mL each admixed in 0.9% sodium chloride injection packaged in AutoDose Infusion System bags. Triplicate test samples were prepared by admixing the necessary amount of each antibiotic with a portion of 0.9% sodium chloride injection and bringing the admixture of each drug to a final volume of 100 mL with additional 0.9% sodium chloride injection. The test solutions were packaged in ethylene vinyl acetate (EVA) plastic containers (AutoDose dags) designed for use in the AutoDose Infusion System. Samples were protected from light and evaluated at appropriate intervals for up to 7 days at 23°C and up to 30 days at 4°C. Physical stability was assessed using a multistep evaluation procedure that included turbidimetric and particulate measurement as well as visual inspection. Chemical stability was assessed using stability-indicating HPLC analytical techniques based on the determination of drug concentrations initially and at appropriate intervals over the study periods. The admixtures were clear and colorless when viewed in normal fluorescent room light and with a Tyndall beam. Measured turbidity and particulate content were low and exhibited little change. HPLC analysis found that both ciprofloxacin and vancomycin hydrochloride remained stable for 30 days at 4°C and 7 days at 23°C. Both ciprofloxacin and vancomycin hydrochloride exhibited physical and chemical stability consistent with previous studies on these drugs. The AutoDose Infusion System bags were not found to affect adversely the physical and chemical stability of these antibiotics.

Stability of piperacillin and ticarcillin in AutoDose infusion system bags.

To evaluate the physical and chemical stability of piperacillin sodium 3 and 4 g/100 mL and ticarcillin disodium 3 g/100 mL each admixed in NaCl 0.9% injection packaged in AutoDose Infusion System bags. Triplicate test samples of the penicillin antibiotics in NaCl 0.9% injection were packaged in ethylene vinyl acetate (EVA) plastic containers, AutoDose bags, designed for use in the AutoDose Infusion System. Samples were stored protected from light and evaluated at appropriate intervals for up to seven days at 23 degrees C and up to 30 days at 4 degrees C. Physical stability was assessed using turbidimetric and particulate measurement as well as visual inspection. Chemical stability was assessed by HPLC. All of the penicillin admixtures initially were clear when viewed in normal fluorescent room light and with a Tyndall beam. Measured turbidity and particulate content were low initially and exhibited little change in the ticarcillin disodium samples throughout the study. The piperacillin sodium samples exhibited small increases in measured haze throughout the study, but no accompanying increase in particulates > or = 1.04 microm was found. All samples were essentially colorless throughout the study. HPLC analysis found some decomposition in the samples. Piperacillin sodium exhibited a 9-10% loss after five days at 23 degrees C. In the samples stored at 4 degrees C, piperacillin sodium exhibited acceptable stability through 21 days of storage, but losses exceeded 10% after 30 days. Ticarcillin disodium exhibited a 7% loss after three days, but 14% after five days at 23 degrees C. Less than 7% loss occurred after 21 days, but 12% loss after 30 days at 4 degrees C. Piperacillin sodium and ticarcillin disodium exhibited physical and chemical stability consistent with previous studies on these drugs. The AutoDose Infusion System bags were not found to adversely affect the physical and chemical stability of these penicillin antibiotics.

Deficits in allothetic and idiothetic spatial behavior in rats with posterior cingulate cortex lesions

The cingulate cortex plays a central role in bridging neocortical and limbic structures involved in allothetic navigation, a form of navigation requiring the use of external cues. Animals can also navigate using idiothetic cues, which are cues generated by self-movement, but there have been no definitive tests of whether cingulate cortex also plays a role in idiothetic navigation. Rats with anterior cingulate (medial frontal) and posterior cingulate cortex (retrosplenial) suction ablations were trained to search for large food pellets on an open table, and the accuracy with which they returned home with the food was measured. In the idiothetic task they searched for food from a novel starting location under infrared light, and with surface olfactory cues displaced. The rats also received two tests of allothetic navigation. They were tested on a matching-to-place task in which they foraged for food from a number of successively presented new locations under normal room light, and they were trained to locate a hidden platform in a swimming pool (Morris place task). The group with posterior cingulate cortex lesions was severely impaired on all of the navigation tasks whereas the group with anterior cingulate cortex lesions displayed no deficit on the idiothetic task and only moderate deficits on the other tasks. The results demonstrate a role for posterior cingulate region in idiothetic navigation.

Incompatibility of Erythromycin Lactobionate and Sulfamethoxazole/Trimethoprim with Linezolid Injection

The objective of this study was to evaluate the physical compatibility and chemical stability of linezolid 200 mg/100 mL admixed with erythromycin lactobionate 500 mg and separately with sulfamethoxazole 400 mg/trimethoprim 80 mg for up to 7 days at 4° C and 23° C. The test samples were prepared by adding the required amount of erythromycin lactobionate and sulfamethoxazole/trimethoprim to separate bags of linezolid injection. Evaluations were made at the initial time point and at 1, 3, 5, and 7 days of storage at temperatures of 4° C and 23° C for physical and chemical stability. Physical stability was assessed using visual observation in normal light and a high-intensity monodirectional light beam (Tyndall beam). In addition, turbidity and particle content were measured electronically. Chemical stability was evaluated by using stability-indicating high-performance liquid chromatographic (HPLC) analytical techniques. The linezolid admixtures with erythromycin lactobionate were clear and colorless when viewed in normal fluorescent room light and using a Tyndall beam. Measured turbidity and particulate content were low and exhibited little change. HPLC analysis found no loss of linezolid in any sample stored at either temperature throughout the study. However, erythromycin lactobionate underwent rapid and extensive losses. Under refrigeration, erythromycin losses were about 45% in 24 hours; at room temperature, losses of over 80% occurred during the first day. The linezolid admixtures with sulfamethoxazole/trimethoprim resulted in gross precipitation nearly immediately upon preparation of all samples. The precipitate consisted of white needle-like crystals. HPLC analysis found that both sulfamethoxazole and trimethoprim had precipitated. Consequently, no further analysis was performed on these samples.

Compatibility and stability of linezolid injection admixed with three quinolone antibiotics.

To evaluate the physical compatibility and chemical stability of linezolid 200 mg/100 mL admixed with ciprofloxacin 400 mg, ofloxacin 400 mg, and levofloxacin 500 mg for seven days at 4 and 23 degrees C. The test samples were prepared by adding the required amount of the quinolone antibiotic to bags of linezolid injection. Evaluations for physical and chemical stability were performed initially and after one, three, five, and seven days of storage at temperatures of 4 and 23 degrees C. Physical stability was assessed using visual observation in normal light and using a high-intensity monodirectional light beam. In addition, turbidity and particle content were measured electronically. Chemical stability of the drugs was evaluated by using stability-indicating HPLC analytical techniques. The linezolid admixtures with levofloxacin and ofloxacin were clear and pale yellow when viewed in normal fluorescent room light, and slightly hazy with a green cast when viewed using a Tyndall beam. Measured turbidity and particulate content were low and exhibited little change. HPLC analysis found no loss of the drugs in any sample stored at either temperature throughout the study. The linezolid admixtures with ciprofloxacin stored at room temperature (23 degrees C) were clear and nearly colorless in normal room light and when viewed using a Tyndall beam. They exhibited little or no change in measured turbidity or particulate content during the study period. HPLC analysis found no loss of either drug in seven days. However, the refrigerated samples were only compatible for 24 hours and developed a gross white precipitate thereafter. Admixtures of linezolid 200 mg/100 mL with levofloxacin 500 mg and with ofloxacin 400 mg were physically compatible and chemically stable for at least seven days stored at 4 and 23 degrees C. Admixtures of linezolid with ciprofloxacin 400 mg were compatible and stable for seven days at 23 degrees C, but ciprofloxacin precipitation occurred after 24 hours stored under refrigeration. Linezolid/ciprofloxacin admixtures should not be stored under refrigeration.

Compatibility and Stability of Linezolid Injection Admixed with Aztreonam or Piperacillin Sodium

To evaluate the physical compatibility and chemical stability of linezolid (Zyvox-Pharmacia) 200 mg/100 mL admixed with aztreonam (Azactam-Squibb) 2 grams and separately with piperacillin sodium (Pipracil-Lederle) 3 grams over 7 days at 4 degrees C and 23 degrees C. Controlled experimental trial. Laboratory. Test samples were prepared by adding the required amount of aztreonam or piperacillin sodium to separate bags of linezolid injection 200 mg/100 mL. Physical compatibility and chemical stability based on drug concentrations initially and after 1, 3, 5, and 7 days of storage at 4 degrees C and 23 degrees C. All of the linezolid admixtures with aztreonam and with piperacillin sodium were clear when viewed in normal fluorescent room light and with a Tyndall beam. Measured turbidity and particulate content were low and exhibited little change throughout the study at both storage temperatures. High-performance liquid chromatography analysis found little or no loss of linezolid in any sample stored at either temperature throughout the study. Aztreonam in the linezolid admixtures was stable for 7 days, exhibiting less than 5% loss at 4 degrees C and 9% loss at 23 degrees C. Piperacillin sodium in the linezolid admixtures was stable for 7 days at 4 degrees C, exhibiting no loss, but was stable for only 3 days at 23 degrees C with losses of about 5%. Losses had increased to 9% to 12% after 5 days of storage at room temperature. Admixtures of linezolid 200 mg/100 mL with aztreonam 2 grams or piperacillin sodium 3 grams were physically compatible and chemically stable for at least 7 days stored at 4 degrees C and for 7 days or 3 days, respectively, at 23 degrees C.