Origin of Homochirality in Amino Acids Induced by Lyman-α Irradiation in the Early Stage of the Milky Way.

The enantiomeric excess (ee) of l-form amino acids found in the Murchison meteorite poses some issues about the cosmic origin of their chirality. Circular dichroism (CD) spectra of amino acids in the far-ultraviolet (FUV) at around 6.8 eV (182 nm) indicate that the circularly polarized light can induce ee through photochemical reactions. Here, we resort to ab initio calculations to extract the CD spectra up to the vacuum-ultraviolet (VUV) region (∼11 eV), and we propose a novel equation to compute the ee applicable to a wider range of light frequency than what is available to date. This allows us to show that the strength of the induced ee (|ee|) in the 10 eV VUV region is comparable to the one in the 6.8 eV FUV region. This feature is common for some key amino acids (alanine, 2-aminobutyric acid, and valine). In space, intense Lyman-α (Lyα) light of 10.2 eV is emitted from star forming regions. This study provides a theoretical basis that Lyα emitter from an early starburst in the Milky Way plays a crucial role in initiating the ee of amino acids.

Enantioselective amino acid interactions in solution.

Enantiomeric excesses (ee) of L-amino acids in meteorites are higher than 10%, especially for isovaline (Iva). This suggests the existence of some kind of triggering mechanism responsible for the amplification of the ee from an initial small value. Here, we investigate the dimeric molecular interactions of alanine (Ala) and Iva in solution as an initial nucleation step of crystals at an accurate first-principles level. We find that the dimeric interaction of Iva is more chirality-dependent than that of Ala, thus providing a clear molecular-level insight into the enantioselectivity of amino acids in solution.

Enantiomeric Excesses of Aminonitrile Precursors Determine the Homochirality of Amino Acids.

High enantiomeric excesses (ee's) of l-amino acids, including non-proteinogenic amino acid isovaline (Iva), were discovered in the Murchison meteorite, but the detailed molecular mechanism responsible for the observed ee of amino acids remains elusive and inconsistent, because Iva has an inverted circular dichroism (CD) spectrum with respect to α-H amino acids, e.g., alanine. To address this issue, we resort to accurate ab initio calculations for amino acids and their precursors in the Strecker synthesis. We evaluated their photolysis-induced ee in the range 5-11 eV including the Lyman alpha emission line (Lyα), the typical intensive 10.2 eV radiation ascribed to the early phase of galactic evolution. We show that only the aminonitrile precursors are characterized by positive ee in the Lyα region, explaining why right-handed circularly polarized Lyα (R-CP-Lyα) induces homologous l-amino acids. This study shows that the homochirality of amino acids is produced at the aminonitrile precursors stage.

Theoretical Investigation into a Possibility of Formation of Propylene Oxide Homochirality in Space.

The preferential synthesis or destruction of a single enantiomer by ultraviolet circularly polarized light (UV-CPL) has been proposed as a possible triggering mechanism for the extraterrestrial origin of homochirality. Herein, we investigate the photoabsorption property of propylene oxide (c-C3H6O) for UV-CPL in the Lyman-α region. Our calculations show that c-C3H6O was produced by CH3+ and CH3CH(OH)CH3 or C3H7• and O (triplet). The computed electronic circular dichroism spectra show that c-C3H6O and the intermediate (CH3CH(OH)CH2+) could absorb the UV-CPL originating from the Lyman-α emitter spectrum, suggesting that the photolysis of c-C3H6O or CH3CH(OH)CH2+ upon irradiation could induce chiral symmetry breakage.

Comprehensive Search of Stable Isomers of Alanine and Alanine Precursors in Prebiotic Syntheses.

Enantiomeric excesses of l-amino acids have been detected in meteorites; however, their molecular mechanism and prebiotic syntheses are still a matter of debate. To elucidate the origin of homochirality, alanine and the chiral precursors formed in prebiotic processes were investigated with regard to their stabilities among their isomers by employing the minimum energy principle, namely, the abundancy of a molecule in the interstellar medium is directly correlated to the stability among isomers. To facilitate the search for possible isomers, we developed a new isomer search algorithm, the random connection method, and performed a thorough search for all the stable isomers within a given chemical formula. We found that alanine and most of its precursors are located at higher energy by more than 5.7 kcal mol-1, with respect to the most stable isomer that consists of a linear-chain structure, whereas only the 2-aminopropanenitrile is the most stable isomer among all others possible. The inherent stability of the α-amino nitrile suggests that the 2-aminopropanenitrile is the dominant contribution in the formation of the common enantiomeric excess over α-amino acids.

GRIM-19 is a target of mycobacterial Zn2+ metalloprotease 1 and indispensable for NLRP3 inflammasome activation.

Tuberculosis is a communicable disease caused by Mycobacterium tuberculosis which primarily infects macrophages and establishes intracellular parasitism. A mycobacterial virulence factor Zn2+ metalloprotease 1 (Zmp1) is known to suppress interleukin (IL)-1ß production by inhibiting caspase-1 resulting in phagosome maturation arrest. However, the molecular mechanism of caspase-1 inhibition by Zmp1 is still elusive. Here, we identified GRIM-19 (also known as NDUFA13), an essential subunit of mitochondrial respiratory chain complex I, as a novel Zmp1-binding protein. Using the CRISPR/Cas9 system, we generated GRIM-19 knockout murine macrophage cell line J774.1 and found that GRIM-19 is essential for IL-1ß production during mycobacterial infection as well as in response to NLRP3 inflammasome-activating stimuli such as extracellular ATP or nigericin. We also found that GRIM-19 is required for the generation of mitochondrial reactive oxygen species and NLRP3-dependent activation of caspase-1. Loss of GRIM-19 or forced expression of Zmp1 resulted in a decrease in mitochondrial membrane potential. Our study revealed a previously unrecognized role of GRIM-19 as an essential regulator of NLRP3 inflammasome and a molecular mechanism underlying Zmp1-mediated suppression of IL-1ß production during mycobacterial infection.

Porphyromonas gingivalis Components/Secretions Synergistically Enhance Pneumonia Caused by Streptococcus pneumoniae in Mice.

Streptococcus pneumoniae is an important causative organism of respiratory tract infections. Although periodontal bacteria have been shown to influence respiratory infections such as aspiration pneumonia, the synergistic effect of S. pneumoniae and Porphyromonas gingivalis, a periodontopathic bacterium, on pneumococcal infections is unclear. To investigate whether P. gingivalis accelerates pneumococcal infections, we tested the effects of inoculating P. gingivalis culture supernatant (PgSup) into S. pneumoniae-infected mice. Mice were intratracheally injected with S. pneumoniae and PgSup to induce pneumonia, and lung histopathological sections and the absolute number and frequency of neutrophils and macrophages in the lung were analyzed. Proinflammatory cytokine/chemokine expression was examined by qPCR and ELISA. Inflammatory cell infiltration was observed in S. pneumoniae-infected mice and S. pnemoniae and PgSup mixed-infected mice, and mixed-infected mice showed more pronounced inflammation in lung. The ratios of monocytes/macrophages and neutrophils were not significantly different between the lungs of S. pneumoniae-infected mice and those of mixed-infected mice. PgSup synergistically increased TNF-α expression/production and IL-17 production compared with S. pneumoniae infection alone. We demonstrated that PgSup enhanced inflammation in pneumonia caused by S. pneumoniae, suggesting that virulence factors produced by P. gingivalis are involved in the exacerbation of respiratory tract infections such as aspiration pneumonia.

TREM2 is a receptor for non-glycosylated mycolic acids of mycobacteria that limits anti-mycobacterial macrophage activation.

Mycobacterial cell-wall glycolipids elicit an anti-mycobacterial immune response via FcRγ-associated C-type lectin receptors, including Mincle, and caspase-recruitment domain family member 9 (CARD9). Additionally, mycobacteria harbor immuno-evasive cell-wall lipids associated with virulence and latency; however, a mechanism of action is unclear. Here, we show that the DAP12-associated triggering receptor expressed on myeloid cells 2 (TREM2) recognizes mycobacterial cell-wall mycolic acid (MA)-containing lipids and suggest a mechanism by which mycobacteria control host immunity via TREM2. Macrophages respond to glycosylated MA-containing lipids in a Mincle/FcRγ/CARD9-dependent manner to produce inflammatory cytokines and recruit inducible nitric oxide synthase (iNOS)-positive mycobactericidal macrophages. Conversely, macrophages respond to non-glycosylated MAs in a TREM2/DAP12-dependent but CARD9-independent manner to recruit iNOS-negative mycobacterium-permissive macrophages. Furthermore, TREM2 deletion enhances Mincle-induced macrophage activation in vitro and inflammation in vivo and accelerates the elimination of mycobacterial infection, suggesting that TREM2-DAP12 signaling counteracts Mincle-FcRγ-CARD9-mediated anti-mycobacterial immunity. Mycobacteria, therefore, harness TREM2 for immune evasion.

First-Principles Study of the Reaction Mechanism of CHO + H on Graphene Surface.

Many organic molecules observed in the interstellar medium are considered to be formed on dust grains and populated into the gas phase. We analyzed the reaction of HCO + H on a graphene surface using ab initio molecular dynamics simulations as a case study of the formation and desorption of organic molecules on interstellar dust particles. During the reactions of chemisorbed CHO (chemisorbed at the C atom) with free H, CO was generated and efficiently desorbed from the surface. These results suggest that the reactions, of which the reactant forms a covalent bond with the surface while the product does not, cause efficient desorption of the product upon reaction. In such reactions a repulsive force between the product and the surface would be generated and accelerate translation of the product in a specific direction. In addition, it was also shown that the branching ratio of the reactions between radical species on the surface would be affected by the form of the adsorption on the surface, e.g., when a free H reacted with the CHO chemisorbed at the C atom, CH2O was not generated.

Dispensable role of chemokine receptors in migration of mycobacterial antigen-specific CD4+ T cells into Mycobacterium-infected lung.

Mycobacterial antigen-specific CD4+ Th1 cells have pivotal role in protective immunity against mycobacterial infections including pulmonary tuberculosis. In the course of the infection, Th1 cells differentiate in the lung-draining lymph nodes and migrate into the infected lung. Chemokine receptors on T cells are involved in T cell migration into the intestine and skin. However, role of chemokine receptors in the migration of CD4+ T cells into the lung is not yet established. To address the issue, the role of chemokine receptors in T cell migration into the mycobacteria-infected lung was analyzed using mycobacterial Ag85B peptide 25-specific T cell receptor-transgenic (P25) CD4+ T cells. The P25 T cells in the Mycobacterium bovis BCG-infected lung and lung-draining mediastinal lymph node expressed chemokine receptors CCR5, CCR6, CXCR3 and CXCR5 which bind chemokines expressed by the BCG-infected lung. To further analyze the role of the chemokine receptors in the migration of the BCG-primed P25 T cells into the lung or mediastinal lymph node, the P25 T cells were adoptively transferred into the BCG-infected wild type mice, and their migration into the lung was monitored. Unexpectedly, blocking of chemokine receptor function with pertussis toxin, a G-protein inhibitor, failed to suppress migration of the T cells into the infected lung although the treatment completely blocked migration of the mediastinal lymph node P25 T cells into the recipient lymph node. The results suggest that interaction of chemokine receptors on mycobacterial antigen-specific Th1 cells with chemokines is dispensable in their migration into the mycobacteria-infected lung.

Influence of technique used to attach the infusion set to peristaltic finger smart-pumps on dispensing time: an experimental study.

BACKGROUND: Infusion sets designed for peristaltic finger smart pumps (PFSPs) are necessary for the pumps' accurate handling. We previously found that medication dispensing is occasionally incomplete following the calculated infusion time when using certain combinations of PFSPs and infusion sets at a Japanese hospital. Thus, in this study, we investigated the cause of this observed delay by determining the effect of infusion set attachment technique on dispensing time using a combination of three kinds of PFSPs and five kinds of polyvinyl chloride (PVC) and polybutadiene (PB) infusion sets. METHODS: PFSPs with their exclusive infusion sets were used. The PVC and PB infusion sets were either not stretched or stretched to 1-3 cm and attached to the PFSP's liquid delivery system. PFSP dispensing rates were set at 25-400 mL/h. The primary outcome was the time required to dispense 100 mL of saline in a volumetric flask. RESULTS: The complete dispensing time correlated with the input time for all equipment combinations when the infusion sets were not stretched before attachment to the PFSP (R2 = 0.9998-1.0000). When stretched, the complete dispensing time was longer than the input time (P < 0.01-0.05, analysis of variance with Tukey-Kramer multiple comparisons). The maximum dispensing time extension ratio for the PVC and PB infusion sets was 141.8% and 113.0%, respectively. CONCLUSION: Certain attachment techniques for infusion sets can adversely prolong drug dispensing time. As such, pharmacists should provide medical staff with information about the devices used to administer drugs, as well as about the drugs themselves.

Interleukin-17 family cytokines in protective immunity against infections: role of hematopoietic cell-derived and non-hematopoietic cell-derived interleukin-17s.

Interleukin-17 family cytokines, consisting of six members, participate in immune response in infections and autoimmune and inflammatory diseases. The prototype cytokine of the family, IL-17A, was originally identified from CD4+ T cells which are now termed Th17 cells. Later, IL-17A-producing cells were expanded to include various hematopoietic cells, namely CD8+ T cells (Tc17), invariant NKT cells, γδ T cells, non-T non-B lymphocytes (termed type 3 innate lymphoid cells) and neutrophils. Some IL-17 family cytokines other than IL-17A are also expressed by CD4+ T cells: IL-17E by Th2 cells and IL-17F by Th17 cells. IL-17A and IL-17F induce expression of pro-inflammatory cytokines to induce inflammation and anti-microbial peptides to kill pathogens, whereas IL-17E induces allergic inflammation. However, the functions of other IL-17 family cytokines have been unclear. Recent studies have shown that IL-17B and IL-17C are expressed by epithelial rather than hematopoietic cells. Interestingly, expression of IL-17E and IL-17F by epithelial cells has also been reported and epithelial cell-derived IL-17 family cytokines shown to play important roles in immune responses to infections at epithelial sites. In this review, we summarize current information on hematopoietic cell-derived IL-17A and non-hematopoietic cell-derived IL-17B, IL-17C, IL-17D, IL-17E and IL-17F in infections and propose functional differences between these two categories of IL-17 family cytokines.

Involvement of IL-17A-producing TCR γδ T cells in late protective immunity against pulmonary Mycobacterium tuberculosis infection.

INTRODUCTION: Interleukin (IL)-17A is a cytokine originally reported to induce neutrophil-mediated inflammation and anti-microbial activity. The CD4+ T cells, which produce IL-17A, have been well characterized as Th17 cells. On the other hand, IL-17A-producing TCR γδ+ T cells have been reported to participate in the immune response at an early stage of infection with Listeria monocytogenes and Mycobacterium bovis in mice. However, the involvement of IL-17A in protective immunity was not clearly demonstrated in the chronic stage of M. tuberculosis-infected mice. METHODS: We analyzed role of IL-17A in host defense against chronically infected M. tuberculosis using IL-17A KO mice. RESULTS: We found that TCR γδ+ T cells are a primary source of IL-17A, but that mycobacterial antigen-specific Th17 cells were hardly detected even at the chronic stage of M. tuberculosis infection. IL-17A-deficient mice showed a decreased survival rate, and increased bacterial burden in the lungs after the infection when compared to the wild-type mice. Furthermore, a histological analysis showed an impaired granuloma formation in the infected lungs of IL-17A-deficient mice, which was considered to be due to a decrease of IFN-γ and TNF at the chronic stage. CONCLUSION: Our data suggest that the IL-17A-producing TCR γδ+ T cells, rather than the Th17 cells, in the infected lungs are an indispensable source of protective immunity against M. tuberculosis infection.

C-Type Lectin Receptor DCAR Recognizes Mycobacterial Phosphatidyl-Inositol Mannosides to Promote a Th1 Response during Infection.

Phosphatidyl-inositol mannosides (PIM) are glycolipids unique to mycobacteria and other related bacteria that stimulate host immune responses and are implicated in mycobacteria pathogenicity. Here, we found that the FcRγ-coupled C-type lectin receptor DCAR (dendritic cell immunoactivating receptor; gene symbol Clec4b1) is a direct receptor for PIM. Mycobacteria activated reporter cells expressing DCAR, and delipidation of mycobacteria abolished this activity. Acylated PIMs purified from mycobacteria were identified as ligands for DCAR. DCAR was predominantly expressed in small peritoneal macrophages and monocyte-derived inflammatory cells in lungs and spleen. These cells produced monocyte chemoattractant protein-1 (MCP-1) upon PIM treatment, and absence of DCAR or FcRγ abrogated MCP-1 production. Upon mycobacterial infection, Clec4b1-deficient mice showed reduced numbers of monocyte-derived inflammatory cells at the infection site, impaired IFNγ production by T cells, and an increased bacterial load. Thus, DCAR is a critical receptor for PIM that functions to promote T cell responses against mycobacteria.

Factors Influencing the Accurate Administration of Peristaltic Finger Infusion Pumps Attached to Polyvinylchloride Infusion Sets Containing Tris(2-ethylhexyl) trimellitate.

An accurate continuous intravenous injection via a peristaltic finger infusion pump has been utilized at outpatient clinics recently. An infusion element designed for this pump is necessary for the accurate handling of the pump, and for proper use of this equipment, we need accurate information. Our experiments have shown that medication administration has occasionally been incomplete at the calculated input time when a peristaltic finger infusion pump has been used. In this paper, we have investigated the cause of the delay in the administration time and the effect of the attachment procedure using a combination of features from three kinds of such infusion pumps and five kinds of exclusive polyvinyl chloride (PVC) infusion sets, under various conditions. Our results suggest that the time required for complete administration was correlated to the input time when five kinds of PVC tubing without stretching were attached to three kinds of peristaltic finger infusion pumps (R(2)=0.9998-1.0000). However, when the PVC tubing was stretched 1-3 cm and was attached to the pump, the time required for complete administration of the solution was prolonged compared to the recommended listed input time (p<0.01-0.05, ANOVA, Tukey-Kramer multiple comparison). Therefore, we suggest that the procedure technique used by the medical staff and involving the infusion pump adversely prolonged the time required for completion of the administration of medication. In our opinion, pharmacists must provide information concerning not only the drugs, but also the medical devices used to the physicians and nurses.

Recombinant Mycobacterium bovis bacillus Calmette-Guérin expressing Ag85B-IL-7 fusion protein enhances IL-17A-producing innate γδ T cells.

Interleukin 7 (IL-7) has an important function in the development and maintenance of IL-17A+ γδ T cells. We here constructed a recombinant Mycobacterium bovis bacillus Calmette-Guérin expressing antigen 85B (Ag85B)-IL-7 fusion protein (rBCG-Ag85B-IL-7). The Ag85B-IL-7 fusion protein and IL-7 were detected in the bacterial lysate of rBCG-Ag85B-IL-7. rBCG-Ag85B-IL-7 was the same in number as control rBCG expressing Ag85B (rBCG-Ag85B) in the lung at the early stage after intravenous inoculation, whereas the numbers of IL-17A+ γδ T cells and Ag-specific Th1 cells were significantly higher in the lungs of mice inoculated with rBCG-Ag85B-IL-7 than those inoculated with rBCG-Ag85B. The Ag-specific Th1 cell response was impaired in mice lacking IL-17A+ γδ T cells after inoculation with rBCG-Ag85B-IL-7. Thus, rBCG-Ag85B-IL-7 increases the pool size of IL-17A+ γδ T cells, which subsequently augment the Th1 response to mycobacterial infection.

Interleukin-22-Induced Antimicrobial Phospholipase A2 Group IIA Mediates Protective Innate Immunity of Nonhematopoietic Cells against Listeria monocytogenes.

Listeria monocytogenes is a bacterial pathogen which establishes intracellular parasitism in various cells, including macrophages and nonhematopoietic cells, such as hepatocytes. It has been reported that several proinflammatory cytokines have pivotal roles in innate protection against L. monocytogenes infection. We found that a proinflammatory cytokine, interleukin 22 (IL-22), was expressed by CD3(+) CD4(+) T cells at an early stage of L. monocytogenes infection in mice. To assess the influence of IL-22 on L. monocytogenes infection in hepatocytes, cells of a human hepatocellular carcinoma line, HepG2, were treated with IL-22 before L. monocytogenes infection in vitro. Gene expression analysis of the IL-22-treated HepG2 cells identified phospholipase A2 group IIA (PLA2G2A) as an upregulated antimicrobial molecule. Addition of recombinant PLA2G2A to the HepG2 culture significantly suppressed L. monocytogenes infection. Culture supernatant of the IL-22-treated HepG2 cells contained bactericidal activity against L. monocytogenes, and the activity was abrogated by a specific PLA2G2A inhibitor, demonstrating that HepG2 cells secreted PLA2G2A, which killed extracellular L. monocytogenes. Furthermore, colocalization of PLA2G2A and L. monocytogenes was detected in the IL-22-treated infected HepG2 cells, which suggests involvement of PLA2G2A in the mechanism of intracellular killing of L. monocytogenes by HepG2 cells. These results suggest that IL-22 induced at an early stage of L. monocytogenes infection enhances innate immunity against L. monocytogenes in the liver by stimulating hepatocytes to produce an antimicrobial molecule, PLA2G2A.

Enhanced effect of BCG vaccine against pulmonary Mycobacterium tuberculosis infection in mice with lung Th17 response to mycobacterial heparin-binding hemagglutinin adhesin antigen.

Although the BCG vaccine can prevent tuberculosis (TB) in infants, its ability to prevent adult pulmonary TB is reportedly limited. Therefore, development of a novel effective vaccine against pulmonary TB has become an international research priority. We have previously reported that intranasal vaccination of mice with a mycobacterial heparin-binding hemagglutinin adhesin (HBHA) plus mucosal adjuvant cholera toxin (CT) enhances production of IFN-γ and anti-HBHA antibody and suppresses extrapulmonary bacterial dissemination after intranasal infection with BCG. In the present study, the effects of intranasal HBHA + CT vaccine on murine pulmonary Mycobacterium tuberculosis (Mtb) infection were examined. Intranasal HBHA + CT vaccination alone failed to reduce the bacterial burden in the infected lung. However, a combination vaccine consisting of s.c. BCG priming and an intranasal HBHA + CT booster significantly enhanced protective immunity against pulmonary Mtb infection on day 14 compared with BCG vaccine alone. Further, it was found that intranasal HBHA + CT vaccine enhanced not only IFN-γ but also IL-17A production by HBHA-specific T cells in the lung after pulmonary Mtb infection. Therefore, this combination vaccine may be a good candidate for a new vaccine strategy against pulmonary TB.

IL-1 receptor antagonist-deficient mice develop autoimmune arthritis due to intrinsic activation of IL-17-producing CCR2(+)Vγ6(+)γδ T cells.

Interleukin-17 (IL-17)-producing γδ T (γδ17) cells have been implicated in inflammatory diseases, but the underlying pathogenic mechanisms remain unclear. Here, we show that both CD4(+) and γδ17 cells are required for the development of autoimmune arthritis in IL-1 receptor antagonist (IL-1Ra)-deficient mice. Specifically, activated CD4(+) T cells direct γδ T-cell infiltration by inducing CCL2 expression in joints. Furthermore, IL-17 reporter mice reveal that the Vγ6(+) subset of CCR2(+) γδ T cells preferentially produces IL-17 in inflamed joints. Importantly, because IL-1Ra normally suppresses IL-1R expression on γδ T cells, IL-1Ra-deficient mice exhibit elevated IL-1R expression on Vγ6(+) cells, which play a critical role in inducing them to produce IL-17. Our findings demonstrate a pathogenic mechanism in which adaptive and innate immunity induce an autoimmune disease in a coordinated manner.

Effects of outside air temperature on the preparation of antineoplastic drug solutions in biological safety cabinets.

PURPOSE: In Japan, biological safety cabinets are commonly used by medical staff to prepare antineoplastic agents. At the Division of Chemotherapy for Outpatients, Nagoya University Hospital, a class II B2 biological safety cabinet is used. The temperature inside this biological safety cabinet decreases in winter. In this study, we investigated the effect of low outside air temperature on the biological safety cabinet temperature, time required to admix antineoplastic agents, and accuracy of epirubicin weight measurement. METHODS: Studies were conducted from 1 January to 31 March 2008 (winter). The outside air temperature near the biological safety cabinet intake nozzle was compared with the biological safety cabinet temperature. The correlation between the outside air temperature and the biological safety cabinet temperature, time for cyclophosphamide and gemcitabine solubilization, and accuracy of epirubicin weight measurement were investigated at low and high biological safety cabinet temperatures. RESULT: The biological safety cabinet temperature correlated with the outside air temperature of 5-20℃ (p < 0.0001). Compared to cyclophosphamide and gemcitabine solubilization in the biological safety cabinet at 25℃, solubilization at 10℃ was significantly delayed (p < 0.01 and p < 0.0001, respectively). Measurement of epirubicin weight by using a syringe lacked accuracy because of epirubicin's high viscosity at low temperatures (p < 0.01). CONCLUSION: These results suggest that the biological safety cabinet temperature decreases when cool winter air is drawn into the biological safety cabinet, affecting the solubilization of antineoplastic agents. We suggest that a decrease in biological safety cabinet temperature may increase the time required to admix antineoplastic agents, thereby increasing the time for which outpatients must wait for chemotherapy.