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1.
Kyobu Geka ; 77(4): 256-261, 2024 Apr.
Article in Japanese | MEDLINE | ID: mdl-38644171

ABSTRACT

A 60-year old woman, sandwiched between two boats was brought to our hospital with severe respiratory failure. She was in pre-shock and there was extensive cutaneous emphysema from the face to abdomen. She required respirator support and bilateral chest tubes for hemopneumothorax. On the patient's 3rd hospital day, she received venovenous extracorporeal membrance oxgenation( ECMO) due to sudden ventilatory failure. The bronchofiberscopy revealed complete disruption of the left main bronchus and occlusion of the right one owing to blood clot and sputum. Because of significant destruction of the left main bronchus, we didn't attempt bronchoplasty, and performed left pneumonectomy under veno-venous (VV)-ECMO. The postoperative course was uneventful, and she was discharged after 30 days with satisfactory outcome.


Subject(s)
Bronchi , Extracorporeal Membrane Oxygenation , Pneumonectomy , Humans , Female , Middle Aged , Bronchi/surgery
2.
Foods ; 13(5)2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38472883

ABSTRACT

The HHP inactivation behaviors of Niigata sake yeast Saccharomyces cerevisiae strain S9arg and its aerobic respiratory-deficient mutant strains were investigated after cultivating them in a YPD media containing 2% to 15% glucose, as well as in moromi mash, in a laboratory-scale sake brewing process. The piezotolerance of strain S9arg, shown after cultivation in a YPD medium containing 2% glucose, decreased to become piezosensitive with increasing glucose concentrations in YPD media. In contrast, the piezosensitivity of a mutant strain UV1, shown after cultivation in the YPD medium containing 2% glucose, decreased to become piezotolerant with increasing glucose concentrations in the YPD medium. The intracellular ATP concentrations were analyzed for an S. cerevisiae strain with intact aerobic respiratory ability, as well as for strain UV1. The higher concentration of ATP after cultivation suggested a higher energy status and may be closely related to higher piezotolerance for the yeast strains. The decreased piezotolerance of strain S9arg observed after a laboratory-scale sake brewing test may be due to a lower energy status resulting from a high glucose concentration in moromi mash during the early period of brewing, as well as a lower aeration efficiency during the brewing process, compared with cultivation in a YPD medium containing 2% glucose.

3.
Front Neurol ; 14: 1258854, 2023.
Article in English | MEDLINE | ID: mdl-37780707

ABSTRACT

Objective: Vagus nerve stimulation (VNS) is a palliative surgery for drug-resistant epilepsy. The two objectives of this study were to (1) determine the seizure type most responsive to VNS and (2) investigate the preventive effect on status epilepticus (SE) recurrence. Methods: We retrospectively reviewed 136 patients with drug-resistant epilepsy who underwent VNS implantation. We examined seizure outcomes at 6, 12, and 24 months following implantation of VNS as well as at the last visit to the Juntendo Epilepsy Center. Univariate analysis and multivariate logistic regression models were used to estimate the prognostic factors. Results: 125 patients were followed up for at least 1 year after VNS implantation. The percentage of patients with at least a 50% reduction in seizure frequency compared with prior to VNS implantation increased over time at 6, 12, and 24 months after VNS implantation: 28, 41, and 52%, respectively. Regarding overall seizure outcomes, 70 (56%) patients responded to VNS. Of the 40 patients with a history of SE prior to VNS implantation, 27 (67%) showed no recurrence of SE. The duration of epilepsy, history of SE prior to VNS implantation and seizure type were correlated with seizure outcomes after VNS implantation in univariate analysis (p = 0.05, p < 0.01, and p = 0.03, respectively). In multivariate logistic regression analysis, generalized seizure was associated with VNS response [odds ratio (OR): 4.18, 95% CI: 1.13-15.5, p = 0.03]. A history of SE prior to VNS implantation was associated with VNS non-responders [(OR): 0.221, 95% CI: 0.097-0.503, p < 0.01]. The duration of epilepsy, focal to bilateral tonic-clonic seizure and epileptic spasms were not significantly associated with VNS responders (p = 0.07, p = 0.71, and p = 0.11, respectively). Conclusion: Following 125 patients with drug-resistant epilepsy for an average of 69 months, 56% showed at least 50% reduction in seizure frequency after VNS implantation. This study suggests that generalized seizure is the most responsive to VNS, and that VNS may reduce the risk of recurrence of SE. VNS was shown to be effective against generalized seizure and also may potentially influence the risk of further events of SE, two marker of disease treatment that can lead to improved quality of life.

4.
Sci Rep ; 13(1): 13697, 2023 Aug 22.
Article in English | MEDLINE | ID: mdl-37607965

ABSTRACT

The unidirectional carbon fiber reinforced polymer (UD-CFRP) lacks the modulus of elasticity and strength in the lateral direction. This study investigates whether matrix resin with CFRP waste, recycled carbon fiber (rCF), can improve the lateral properties of CFRP. In total, twelve CFRP strips specimen were prefabricated of unidirectional carbon fiber (CF) sheet by hand lay-up (HLU) method and were tested by tensile test and X-ray computed tomography (X-ray CT). Factors such as fiber direction and void distribution significantly affecting its mechanical properties are assessed by X-ray CT inspection. It can be seen that rCF is mixed in a random direction at the position filled with matrix resin without rCF. However, a similar frequency of unimpregnation and voids can be observed in both specimens. Test results showed that experimental values of CFRP laminates with rCF-mixed matrix resin increased compared to the CFRP laminates without rCF. The percentage increase in the lateral tensile strength and modulus of elasticity of the rCFRP compared to the control specimen without rCF is 27.36% and 10.62%, respectively. This study proved that rCF can increase the lateral properties of unidirectional CFRP and shows the effective use of rCF for strengthening material in construction applications.

5.
Pestic Biochem Physiol ; 191: 105378, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36963946

ABSTRACT

Dinotefuran, a neonicotinoid, is a unique insecticide owing to its structure and action. We took two approaches that employed insects with controlled expression of nicotinic acetylcholine receptor (nAChR)-encoding genes to gain insight into the uniqueness of dinotefuran. First, we examined the insecticidal activity of dinotefuran and imidacloprid against brown planthoppers (Nilaparvata lugens), in which the expression of eight (of 13) individual subunit-encoding genes was specifically reduced using RNA interference. Knockdown of the tested gene, except one, resulted in a decrease in sensitivity to imidacloprid, whereas the sensitivity of N. lugens to dinotefuran decreased only when two of the eight genes were knocked down. These findings imply that a major dinotefuran-targeted nAChR subtype may contain specific subunits although imidacloprid acts on a broad range of receptor subtypes. Next, we examined the effects of knockout of Drosophila α1 subunit-encoding gene (Dα1) on the insecticidal effects of dinotefuran and imidacloprid. Dα1-deficient flies (Dα1KO) demonstrated the same sensitivity to dinotefuran as control flies, but a decreased sensitivity to imidacloprid. This difference was attributed to a reduction in imidacloprid-binding sites in Dα1KO flies, whereas the binding of dinotefuran remained unchanged. RNA sequencing analysis indicated that Dα2 expression was specifically enhanced in Dα1KO flies. These findings suggest that changes in Dα1 and Dα2 expression contribute to the differences in the insecticidal activity of dinotefuran and imidacloprid in Dα1KO flies. Overall, our findings suggest that dinotefuran acts on distinct nAChR subtypes.


Subject(s)
Insecticides , Receptors, Nicotinic , Animals , Insecticides/pharmacology , Receptors, Nicotinic/metabolism , Neonicotinoids/pharmacology , Nitro Compounds/pharmacology , Insecta , Drosophila/metabolism
6.
Acta Neurochir (Wien) ; 165(1): 265-269, 2023 01.
Article in English | MEDLINE | ID: mdl-35934751

ABSTRACT

Epileptic seizure is the common symptom associated with lipomas in the Sylvian fissure (Sylvian lipomas). Removal of these lipomas carries risks of hemorrhage and brain damage. We report a surgical strategy of not removing the lipoma in a case of intractable temporal lobe epilepsy associated with Sylvian lipoma. We performed anterior temporal lobectomy with preservation of the pia mater of the Sylvian fissure and achieved seizure freedom. Focal cortical dysplasia type 1 of the epileptic neocortex adjacent to the Sylvian lipoma was pathologically diagnosed. We recommend our surgical procedure in similar cases to avoid complications and achieve adequate seizure control.


Subject(s)
Brain Neoplasms , Epilepsy, Temporal Lobe , Epilepsy , Lipoma , Humans , Epilepsy, Temporal Lobe/diagnostic imaging , Epilepsy, Temporal Lobe/etiology , Epilepsy, Temporal Lobe/surgery , Magnetic Resonance Imaging/adverse effects , Brain Neoplasms/complications , Brain Neoplasms/diagnostic imaging , Brain Neoplasms/surgery , Seizures , Lipoma/complications , Lipoma/diagnostic imaging , Lipoma/surgery
7.
Foods ; 10(10)2021 Sep 23.
Article in English | MEDLINE | ID: mdl-34681296

ABSTRACT

A sparkling-type draft cloudy sake (Japanese rice wine), AWANAMA, was recently developed using high hydrostatic pressure (HHP) treatment as a non-thermal pasteurization method. This prototype sake has a high potential market value, since it retains the fresh taste and flavor similar to draft sake while avoiding over-fermentation. From an economic point of view, a lower pressure level for HHP pasteurization is still required. In this study, we carried out a genome analysis of a pressure-sensitive (piezosensitive) mutant strain, a924E1, which was generated by UV mutagenesis from a laboratory haploid Saccharomyces cerevisiae strain, KA31a. This mutant strain had a deletion of the COX1 gene region in the mitochondrial DNA and had deficient aerobic respiration and mitochondrial functions. A metabolomic analysis revealed restricted flux in the TCA cycle of the strain. The results enabled us to use aerobic respiration deficiency as an indicator for screening a piezosensitive mutant. Thus, we generated piezosensitive mutants from a Niigata-sake yeast strain, S9arg, which produces high levels of ethyl caproate but does not produce urea and is consequently suitable for brewing a high-quality sake. The resultant piezosensitive mutants showed brewing characteristics similar to the S9arg strain. This study provides a screening method for generating a piezosensitive yeast mutant as well as insight on a new way of applying HHP pasteurization.

8.
Pest Manag Sci ; 77(8): 3763-3776, 2021 Aug.
Article in English | MEDLINE | ID: mdl-32954620

ABSTRACT

BACKGROUND: Root-knot nematodes are plant-parasitic nematodes that cause immense damage to a broad range of cultivated crops by forming root galls, resulting in yield losses in crops. To facilitate the development of faster-acting selective nematicides, we cloned three cDNAs encoding UNC-49B proteins from the southern root-knot nematode Meloidogyne incognita and examined their functional and pharmacological properties by two-electrode voltage clamp electrophysiology using a Xenopus oocyte expression system. RESULTS: The three cloned cDNAs encoded Min-UNC-49B, Min-UNC-49B-L and Min-UNC-49B-XL; the last two proteins have longer N-terminal regions than the first protein. When expressed in Xenopus oocytes, these proteins responded to γ-aminobutyric acid (GABA) to activate currents with high-micromolar or low-millimolar half-maximal effective concentration (EC50 ) values, indicating the formation of functional homo-pentameric GABA receptors. Fipronil and picrotoxinin inhibited GABA-induced currents with high-nanomolar and low-micromolar half-maximal inhibitory concentration (IC50 ) values, respectively, in oocytes expressing Min-UNC-49B. The G2'A and T6'M mutations in the second transmembrane domain of Min-UNC-49B enhanced and reduced the sensitivity of Min-UNC-49B to these two antagonists, respectively. Samaderine B and SF-14 inhibited GABA responses in oocytes expressing Min-UNC-49B with low-micromolar and high-nanomolar IC50 values, respectively. Ivermectin, α-terpineol, thymol and methyl eugenol exerted dual effects on Min-UNC-49B by potentiating currents induced by low concentrations of GABA and inhibiting currents induced by high concentrations of GABA. CONCLUSION: We have shown that structurally diverse compounds act at Min-UNC-49B GABA receptors. Our results may serve as a starting point to decipher the molecular function of native GABA receptors of plant-parasitic nematodes, which could aid in the structure-based design of novel nematicides. © 2020 Society of Chemical Industry.


Subject(s)
Receptors, GABA , Tylenchoidea , Animals , Cloning, Molecular , Receptors, GABA/genetics , Xenopus laevis , gamma-Aminobutyric Acid
9.
Pestic Biochem Physiol ; 165: 104554, 2020 May.
Article in English | MEDLINE | ID: mdl-32359545

ABSTRACT

Dinotefuran (DTF) is a systemic neonicotinoid insecticide characterized by a tetrahydrofuran ring. In the present study, we examined the characteristics of DTF binding to native nicotinic acetylcholine receptors (nAChRs) expressed in the American cockroach Periplaneta americana using radioligand-binding methods. The Scatchard analysis, using [3H]imidacloprid (IMI), indicated that IMI has a single class of high-affinity binding sites in the P. americana nerve cord. In contrast, the Scatchard analysis using [3H]DTF indicated that DTF has two different classes of binding sites. Both DTF and IMI were found to bind to one of the classes, for which DTF showed low affinity. The other class, for which DTF showed high affinity, was localized in the abdominal nerve cord but not in the thoracic nerve cord. IMI showed low affinity for the high-affinity DTF binding sites. Our data suggest that DTF binds with high affinity to a nAChR subtype distinct from the high-affinity subtype for IMI. This difference might be responsible, at least in part, for the difference in resistance development to DTF and IMI in P. americana.


Subject(s)
Cockroaches , Insecticides , Periplaneta , Receptors, Nicotinic , Animals , Binding Sites , Guanidines , Neonicotinoids , Nitro Compounds
10.
Clin Interv Aging ; 12: 1451-1457, 2017.
Article in English | MEDLINE | ID: mdl-28979107

ABSTRACT

In our worldwide aging society, elderly people should maintain cognitive and physical function to help avoid health problems. Dementia is a major brain disease among elderly people, and is caused by cognitive impairment. The locomotive syndrome (LS) refers to a condition in which people require healthcare services because of problems associated with locomotion. The purpose of this study was to determine the association between cognitive impairment and LS. Study participants were 142 healthy elderly female volunteers living in a rural area in Japan. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). A score of ≤26 points on the MMSE was used to indicate categorically defined poor cognitive performance (cognitive impairment). The LS was defined by a score ≥16 points, and non-LS as <16 points, on the 25-question Geriatric Locomotive Function Scale (GLFS-25). Twenty-one participants (14.8%) had an MMSE score ≤26, and 19.0% were found to have LS. Compared with the MMSE >26 group, the ≤26 group was significantly older, had a higher percentage of body fat, and a higher GLFS-25 score. Those with LS were significantly older, had a higher body mass index, a higher percentage of body fat, and a lower MMSE score. Participants in the LS group had higher odds of cognitive impairment than those without LS [odds ratio (OR) =3.08] by logistic regression analysis adjusted for age. Furthermore, participants with GLFS-25 scores ≥6 had higher odds of cognitive impairment than those with a GLFS-25 score <6 by logistic regression analysis adjusted for both age (OR =4.44), and age and percent body fat (OR =4.12). These findings suggest that a strong relationship exists between the early stage of decreased motor function and cognitive impairment.


Subject(s)
Cognitive Dysfunction/epidemiology , Locomotion/physiology , Mobility Limitation , Physical Fitness/psychology , Quality of Life , Aged , Aged, 80 and over , Cognitive Dysfunction/psychology , Female , Humans , Independent Living , Japan , Syndrome
11.
Biophys Chem ; 231: 87-94, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28578998

ABSTRACT

We previously obtained a pressure-tolerant (piezotolerant) and a pressure sensitive (piezosensitive) mutant strain, under ambient temperature, from Saccharomyces cerevisiae strain KA31a. The inactivation kinetics of these mutants were analyzed at 150 to 250MPa with 4 to 40°C. By a multiple regression analysis, the pressure and temperature dependency of the inactivation rate constants k values of both mutants, as well as the parent strain KA31a, were well approximated with high correlation coefficients (0.92 to 0.95). For both mutants, as well as strain KA31a, the lowest k value was shown at a low pressure levels with around ambient temperature. The k value approximately increased with increase in pressure level, and with increase and decrease in temperature. The piezosensitive mutant strain a924E1 showed piezosensitivity at all pressure and temperature levels, compared with the parent strain KA31a. In contrast, the piezotolerant mutant strain a2568D8 showed piezotolerance at 4 to 20°C, but did not show significant piezotolerance at 40°C. These results of the variable influence of temperature on pressure inactivation of these strains would be important for better understanding of piezosensitive and piezotolerant mechanisms, as well as the pressure inactivation mechanism of S. cerevisiae.


Subject(s)
Saccharomyces cerevisiae/growth & development , Hydrostatic Pressure , Kinetics , Regression Analysis , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Temperature
12.
Biophys Chem ; 231: 105-110, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28506613

ABSTRACT

We analyzed the effect of high hydrostatic pressure (HHP) treatment on reducing sugar production in the tuberous root of sweet potato (Ipomoea batatas), based on pressure-gelatinization of starch and subsequent saccharification by internal amylases. HHP treatment at up to 600MPa at ambient temperature for 10min did not apparently affect the reducing sugar concentration in tuberous root. However, HHP treatment at 100 to 500MPa and 60°C or 70°C for 10min increased reducing sugar concentration as both the pressure and temperature increased. The reducing sugar concentration after HHP treatment at 500MPa and 70°C for 10min was roughly comparable to that of the thermal treatment control (80°C for 10min under atmospheric pressure). HHP treatment enabled the gelatinization and enzymatic saccharification of starch in the tuberous root of sweet potato, at a lower temperature than required by thermal treatment at atmospheric pressure.


Subject(s)
Ipomoea batatas/metabolism , Starch/chemistry , Amylases/metabolism , Hydrostatic Pressure , Microscopy , Plant Proteins/metabolism , Plant Roots/metabolism , Temperature
13.
Biophys Chem ; 231: 79-86, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28314628

ABSTRACT

Petit-High Pressure Carbon Dioxide (p-HPCD) is a promising nonthermal technology for foods pasteurization. Cluster analysis of gene expression profiles of Saccharomyces cerevisiae exposed to various stresses exhibited that gene expression profile for p-HPCD stress (0.5MPa, 25°C) was grouped into a cluster including profiles for Sodium Dodecyl Sulfate and Roundup herbicide. Both are detergents that can disorder membrane structurally and functionally, which suggests that cell membrane may be a target of p-HPCD stress to cause cell growth inhibition. Through metabolomic analysis, amount of S-Adenosylmethionine (AdoMet) that is used as methyl donor to participate in phosphatidylcholine synthesis via phosphatidylethanolamine (PE) methylation pathway, was increased after p-HPCD treatment for 2h. The key gene OPI3 encoding phospholipid methyltransferase that catalyzes the last two steps in PE methylation pathway was confirmed significantly induced by RT-PCR. Transcriptional expression of genes (MET13, MET16, MET10, MET17, MET6 and SAM2) related to AdoMet biosynthesis was also significantly induced. Choline as the PC precursor and ethanolamine as PE precursor in Kennedy pathway were also found increased under p-HPCD condition. We also found that amounts of most of amino acids involving protein synthesis were found decreased after p-HPCD treatment for 2h. Moreover, morphological changes on cell surface were observed by scanning electron microscope. In conclusion, the effects of p-HPCD stress on cell membrane appear to be a very likely cause of yeast growth inhibition and the enhancement of PC synthesis could contribute to maintain optimum structure and functions of cell membrane and improve cell resistance to inactivation.


Subject(s)
Carbon Dioxide/chemistry , Phosphatidylcholines/metabolism , S-Adenosylmethionine/metabolism , Saccharomyces cerevisiae/metabolism , Biocatalysis , Cluster Analysis , Metabolomics , Microscopy, Electron, Scanning , Phosphatidyl-N-Methylethanolamine N-Methyltransferase/genetics , Phosphatidyl-N-Methylethanolamine N-Methyltransferase/metabolism , Phosphatidylcholines/chemistry , Pressure , S-Adenosylmethionine/chemistry , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae Proteins/metabolism
14.
PLoS One ; 12(3): e0174549, 2017.
Article in English | MEDLINE | ID: mdl-28334042

ABSTRACT

PURPOSE: This study examined the internal Cs exposure of residents and the Cs present in food products produced in Namie. Whole-body counter (WBC) was used for the measurement of internal exposure per each whole body of examinees. METHODS: The food products which appeared to be used for consumption, were brought by residents and commercially available food items were excluded. Most of them were wild plants or food items produced by residents. Four years of data from April 2012 to March 2013 (fiscal 2012) and April 2015 to March 2016 (Fiscal 2015) were analyzed and studied. RESULTS: The average radioactivity measured by WBC was approximately 5 Bq for Cs-134, and 20 Bq for Cs-137 and the average committed effective dose was approximately 1 µSv. The average for the residents with detectable radioactivity was 25 µSv, and the human health effects are considered to be extremely low risk. However, the radioactivity of the affected individuals showed a higher value than the theoretical attenuation rate. The majority (83.2%) of individuals exhibiting radioactivity were over 50 years old. The number of food products brought in for detection decreased as the study period progressed, but the number of food products with radioactivity had increased. While the items with a higher detection rate of radioactivity included fruits such as citron and persimmon, shiitake mushrooms exhibited the highest radioactivity. Moreover, the radioactivity of seven items in these 10 items decreased from fiscal 2012 to fiscal 2015. Mushrooms had high radioactivity and were produced over a wide area. CONCLUSION: We suggest that the elderly try to enjoy life and eat wild plants in moderation while inspecting food products. Therefore, we will continue to work in raising awareness of radiation and its potential presence in food products and thus the continuing necessity of monitoring radioactivity in food in the future.


Subject(s)
Cesium Radioisotopes/analysis , Food Contamination, Radioactive/analysis , Fukushima Nuclear Accident , Radiation Monitoring/methods , Whole-Body Counting , Age Factors , Aged , Female , Humans , Male , Middle Aged
15.
Neurotoxicology ; 60: 245-253, 2017 May.
Article in English | MEDLINE | ID: mdl-27139242

ABSTRACT

The biogenic amine histamine (HA) is not only the neurotransmitter of photoreceptors but also has important roles in mechanosensory reception, temperature preference, sleep and olfactory processing in insects. Two cDNAs (MdhclA and MdhclB) that encode HA-gated chloride channel subunits (MdHCLA and MdHCLB) were cloned from the housefly Musca domestica. The cRNAs were injected into Xenopus laevis oocytes to examine the functions and pharmacological characteristics of MdHCLA and MdHCLB channels using a two-electrode voltage clamp method. HA was used to activate MdHCLA and MdHCLB channels to evoke inward currents with EC50s of 33.1µM and 6.28µM, respectively. 2-(3-Trifluoromethylphenyl)histamine, an HA H1 receptor agonist, was a partial agonist of MdHCLB receptors with an EC50 of 49.4µM. MdHCLB channels were also activated by γ-aminobutyric acid (GABA) and monoamines, such as octopamine, serotonin (5-HT) and dopamine (DA); 5-HT and DA also acted as competitive antagonists. GABA acted as a full agonist of MdHCLB receptors with an EC50 of 1.11mM. d-Tubocurarine, cimetidine and picrotoxinin were poor inhibitors of HA- and GABA-evoked currents in MdHCLB channels. Our data show that HCLB channels are more sensitive to agonists when compared with HCLA channels. HCLB channels are also affected by antagonists but insusceptible to known insecticides that target GABA- and glutamate-gated chloride channels.


Subject(s)
Chloride Channels/pharmacology , Histamine/pharmacology , Animals , Chloride Channel Agonists/pharmacology , Chloride Channels/antagonists & inhibitors , Chloride Channels/genetics , Chloride Channels/physiology , DNA, Complementary/genetics , Dopamine/pharmacology , Female , Houseflies , Insecticides/pharmacology , Ion Channel Gating/drug effects , Octopamine/pharmacology , Serotonin/pharmacology , Xenopus laevis , gamma-Aminobutyric Acid/pharmacology
16.
Chemosphere ; 143: 123-7, 2016 Jan.
Article in English | MEDLINE | ID: mdl-25956024

ABSTRACT

Today, nanoparticles are used in many products. One of the most common nanoparticles is titanium dioxide (TiO2). These particles generate reactive oxygen species (ROS) upon UV irradiation. Although nanoparticles are very useful in many products, there are concerns about their biological and ecological effects when released into the environment. Thus, it was assessed that the effect of TiO2 nano-objects, and their aggregates and agglomerates greater than 100nm (NOAA) on microbes under UV irradiation by using Escherichia coli and Saccharomyces cerevisiae. ROS generation was evaluated by adding TiO2 nanoparticles and methylene blue to distilled water. We also assessed growth inhibition by adding TiO2 nanoparticles and microbes in minimal agar medium. Moreover, microbial inactivation was assessed by adding TiO2 nanoparticles and microbes to PBS. Upon UV irradiation, TiO2-NOAAs decomposed methylene blue and generated ROS. TiO2-NOAAs also decomposed methylene blue in minimal agar medium under UV irradiation; however, they did not inhibit microbial growth. Surprisingly, TiO2-NOAAs in the medium protect microbes from UV irradiation as colony formation was observed only near TiO2-NOAAs. In PBS, TiO2-NOAAs did not inactivate microbes but instead protected microbes from lethal UV irradiation. These results suggest that the amount of ROS generated by TiO2-NOAAs is not enough to inactivate microbes. In fact, our results suggest that TiO2-NOAAs may protect microbes from UV irradiations.


Subject(s)
Ceramides/chemistry , Disinfection/methods , Nanoparticles/chemistry , Titanium/chemistry , Ultraviolet Rays , Adsorption , Agar/chemistry , Catalysis , Escherichia coli/metabolism , Methylene Blue/chemistry , Microbial Viability , Nanotechnology , Reactive Oxygen Species/chemistry , Saccharomyces cerevisiae/metabolism
17.
J Food Sci ; 80(5): M1051-9, 2015 May.
Article in English | MEDLINE | ID: mdl-25881710

ABSTRACT

High hydrostatic pressure causes physical stress to microorganisms; therefore, this technology may be applied to food pasteurization without introducing the unfavorable effects of thermal denaturation. However, its application is limited to high-value foods because the treatment requires a robust steel vessel and expensive pressurization equipment. To reduce these costs, we studied the pasteurization of Saccharomyces cerevisiae using relatively moderate high-pressure levels. A mutant strain isolated by ultraviolet mutagenesis showed significant loss of viability under high-pressure conditions. Gene expression analysis of the mutant strain revealed that it incurred a deletion of the COX1 gene. Our results suggest that the pressure-sensitivity can readily be introduced into industrial/food microorganisms by complementing a COX1 deleted mitochondria.


Subject(s)
Cyclooxygenase 1/genetics , Gene Deletion , Saccharomyces cerevisiae/physiology , Hydrostatic Pressure , Mitochondria/enzymology , Mutagenesis , Pasteurization/instrumentation , Saccharomyces cerevisiae/enzymology , Saccharomyces cerevisiae/genetics
18.
J Gen Appl Microbiol ; 60(2): 79-88, 2014.
Article in English | MEDLINE | ID: mdl-24859866

ABSTRACT

The carbon storage regulator (Csr) global regulatory system is conserved in many eubacteria and coordinates the expression of various genes that facilitate adaptation during the major physiological growth phase. The Csr system in Escherichia coli comprises an RNA-binding protein, CsrA; small non-coding RNAs, CsrB and CsrC; and a decay factor for small RNAs, CsrD. In this study, we identified the Csr system in Serratia marcescens 2170. S. marcescens CsrA was 97% identical to E. coli CsrA. CsrB and CsrC RNAs had typical stem-loop structures, including a GGA motif that is the CsrA binding site. CsrD was composed of N-terminal two times transmembrane region and HAMP-like, GGDEF, and EAL domains. Overexpression of S. marcescens csr genes complemented the phenotype of E. coli csr mutants. S. marcescens CsrD affected the decay of CsrB and CsrC RNAs in E. coli. These results suggest that the Csr system in S. marcescens is composed of an RNA-binding protein, two Csr small RNAs, and a decay factor for Csr small RNAs.


Subject(s)
Adaptation, Physiological , Carbon/metabolism , Gene Expression Regulation, Bacterial , RNA, Small Untranslated/metabolism , Serratia marcescens/physiology , Transcription Factors/metabolism , Base Sequence , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Escherichia coli/genetics , Genetic Complementation Test , Molecular Sequence Data , Nucleic Acid Conformation , RNA Stability , RNA, Small Untranslated/genetics , Sequence Analysis, DNA , Sequence Homology , Serratia marcescens/genetics , Serratia marcescens/metabolism , Transcription Factors/genetics
19.
Springerplus ; 2: 602, 2013.
Article in English | MEDLINE | ID: mdl-24324921

ABSTRACT

5-Aminolevulinic acid (ALA) is a photosensitizer used in photodynamic therapy (PDT) because it causes preferential accumulation of protoporphyrin IX (PpIX) in tumor cells, where it forms singlet oxygen upon light irradiation and kills the tumor cells. Our previous study demonstrated that PpIX enhances generation of reactive oxygen species by physicochemical interaction with X-rays. We investigated the effect of ALA administration with X-ray irradiation of mouse B16-BL6 melanoma cells in vitro and in vivo. ALA facilitates PpIX accumulation in tumor cells and enhances ROS generation in vitro. Tumor suppression significantly improved in animals treated with fractionated doses of radiation (3 Gy × 10; total, 30 Gy) with local administration of 50 mg/kg ALA at 24 h prior to fractional irradiation. These results suggest ALA may improve the efficacy of cancer radiotherapy by acting as a radiomediator.

20.
J Biosci Bioeng ; 113(6): 788-91, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22382011

ABSTRACT

Using microplates as pressure and cultivation vessels, a high-throughput method was developed for analyzing the high-pressure inactivation kinetics of microorganisms. The loss of viability from a high-pressure treatment, measured based on the growth delay during microplate cultivation, showed reproducibility with the conventional agar plate method and was applicable for the kinetics analysis.


Subject(s)
Disinfection/methods , Microbial Viability , Pressure , Kinetics , Reproducibility of Results
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