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1.
Eur J Radiol Open ; 12: 100565, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38699593

RESUMO

Purpose: We compared cerebrospinal fluid (CSF) leak conspicuity and image quality as visualized using 3D versus 2D magnetic resonance (MR) myelography in patients with spinal CSF leaks. Methods: Eighteen patients underwent spinal MR imaging at 3 Tesla. Three board-certified radiologists independently evaluated CSF leak conspicuity and image quality on a 4-point scale; the latter assessed by scoring fat suppression, venous visualization, and severity of CSF flow artifacts. Additionally, the evaluators ranked the overall performances of 2D versus 3D MR myelography upon completing side-by-side comparisons of CSF leak conspicuity. Inter-reader agreement was determined using the Gwet's AC1. Results: The quality of 3D MR myelography images was significantly better than that of 2D MR myelography with respect to CSF leak conspicuity (mean scores: 3.3 vs. 1.9, p < 0.0001) and severity of CSF flow artifacts on the axial view (mean scores: 1.0 vs. 2.5, p = 0.0001). Inter-reader agreement was moderate to almost perfect for 2D MR myelography (AC1 = 0.55-1.00), and almost perfect for 3D MR myelography (AC1 = 0.85-1.00). Moreover, 3D MR myelography was judged to be superior to 2D acquisition in 78 %, 83 %, and 83 % of the samples per readers 1, 2 and 3, respectively; the inter-reader agreement was almost perfect (AC1: reader 1 vs. 2; 0.98, reader 2 vs. 3; 0.96, reader 3 vs. 1; 0.98). Conclusion: CSF leaks are more conspicuous when using 3D MR myelography than when using its 2D counterpart; therefore, the former is more reliable for identifying such leaks.

2.
Keio J Med ; 72(4): 102-105, 2023 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-37743529

RESUMO

We encountered a-27-year-old female patient who developed refractory severe headache and photophobia after the first dose of COVID-19 vaccine. Despite her prior history of migraine, we diagnosed COVID-19 vaccine-induced aseptic meningitis. Symptoms were significantly resolved after methylprednisolone therapy. On reviewing the literature, we could find only nine similar cases, with over half of them affecting women aged 20-40 years. Although uncommon, aseptic meningitis should be suspected in patients with persistent or delayed onset of headache following COVID-19 vaccination.


Assuntos
Vacina BNT162 , COVID-19 , Meningite Asséptica , Feminino , Humanos , Vacina BNT162/efeitos adversos , COVID-19/prevenção & controle , Cefaleia/induzido quimicamente , Meningite Asséptica/induzido quimicamente , Vacinação/efeitos adversos , Adulto
3.
Int J Mol Sci ; 24(16)2023 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-37628930

RESUMO

Nitric oxide (NO) is involved in the pathogenesis of cerebral ischemic injury. Here, we investigated the effects of aging on NO production during cerebral ischemia-reperfusion (IR). Male Wister rats (WRs) were assigned to 12-month-old (older; n = 5) and 3-month-old (younger; n = 7) groups. Similarly, male spontaneous hypertensive rats (SHRs) were allocated to 12-month-old (older; n = 6) and 3-month-old (younger; n = 8) groups. After anesthesia, their NO production was monitored using in vivo microdialysis probes inserted into the left striatum and hippocampus. Forebrain cerebral IR injuries were produced via ligation of the bilateral common carotid arteries, followed by reperfusion. The change in the NO3- of the older rats in the SHR groups in the striatum was less compared to that of the younger rats before ischemia, during ischemia, and after reperfusion (p < 0.05). In the hippocampus, the change in the NO3- of the older rats in the SHR groups was lower compared to that of the younger rats after reperfusion (p < 0.05). There were no significant differences between the two WR groups. Our findings suggested that aging in SHRs affected NO production, especially in the striatum, before and during cerebral ischemia, and after reperfusion. Hypertension and aging may be important factors impacting NO production in brain IR injury.


Assuntos
Lesões Encefálicas , Traumatismo por Reperfusão , Masculino , Ratos , Animais , Ratos Wistar , Óxido Nítrico , Microdiálise , Infarto Cerebral , Ratos Endogâmicos SHR , Reperfusão , Envelhecimento , Prosencéfalo
4.
Transplant Cell Ther ; 29(10): 622-631, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37536453

RESUMO

In Japan, only single-unit cord blood transplantations (CBTs) are typically performed, and their number has increased over the last 23 years, with ongoing improvement in results. In most cases, CBTs with multiple HLA mismatches are used, owing to a low HLA barrier, and lower engraftment rate is a problem that must be overcome. Here, as part of an effort to improve guidelines for the selection and processing of CB units for transplantation, we sought to assess the present status of CBT in Japan and to elucidate factors contributing to the favorable outcomes, focusing in particular on selection by cell components of CB unit and HLA allele matching. We conducted a nationwide study analyzing 13,443 patients who underwent first CBT between in Japan between December 1997 and December 2019 using multivariate regression analysis. Both patient- and transplantation-related variables, such as age and Hematopoietic Cell Transplantation Comorbidity Index, as well as selected CB unit characteristics, were included in the analysis. The interaction analysis elucidated that CB unit selection favoring higher counts of CD34+ cells and granulocyte macrophage colony-forming units (GM-CFU)/kg, but not of total nucleated cells, contributed to improved engraftment after transplantation. Moreover, a higher CD34+ cell dose was associated with improved overall survival (OS). Distinctive HLA allele matching was observed. A 0 or 1 HLA allele mismatch between patient and donor had favorable engraftment and carried significantly lower risks of acute GVHD and chronic GVHD but had a significantly higher leukemia relapse rate, compared with a 3-HLA allele mismatch. HLA-DRB1 mismatches were associated with reduced risk of leukemia relapse. Notably, the number of HLA allele mismatches had no incremental effect on engraftment, acute and chronic GVHD, or relapse incidence. As a result, 5-year overall survival did not differ significantly among patients receiving CB units with 0 to 7 HLA allele mismatches. The main points of CB unit selection are as follows. First, selection according to a higher number of CD34+ cells/kg and then of CFU-GM/kg is recommended to obtain favorable engraftment. A unit with .5 × 105 CD34+ cells/kg is minimally acceptable. For units with a CD34+ cell dose of .5 to 1.0 × 105 cells/kg, applying the parameter of ≥20 to 50 × 103 GM-CFU/kg (66.5% of transplanted CB units in this cohort) is associated with a neutrophil engraftment rate of approximately 90%. A unit with ≥1.0 × 105 CD34+ cells/kg can achieve a ≥90% mean neutrophil engraftment rate. Subsequently, HLA allele matching of HLA-A, -B, -C, and -DRB1 at the 2-field level should be searched for units with 0 or 1 HLA allele mismatch in the host-versus-graft direction for favorable engraftment. Units with 2 to 6 HLA allele mismatches are acceptable in patients age ≥15 years and units with 2 to 4 HLA allele mismatches are acceptable in patients age ≤14 years. Units with HLA-DRB1 and/or -B allele mismatch(es) might not be preferable owing to an increased GVHD risk. Our analysis demonstrates that single-unit CBT with the selection of adequate CD34+/kg and GM-CFU/kg and HLA allele matching showed favorable outcomes in both pediatric and adult patients.

5.
Int J Mol Sci ; 24(7)2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-37047057

RESUMO

Cerebrospinal fluid (CSF) plays an important role in the homeostasis of the brain. We previously reported that CSF major glycoproteins are biosynthesized in the brain, i.e., lipocalin-type prostaglandin D2 synthase (L-PGDS) and transferrin isoforms carrying unique glycans. Although these glycoproteins are secreted from distinct cell types, their CSF levels have been found to be highly correlated with each other in cases of neurodegenerative disorders. The aim of this study was to examine these marker levels and their correlations in other neurological diseases, such as depression and schizophrenia, and disorders featuring abnormal CSF metabolism, including spontaneous intracranial hypotension (SIH) and idiopathic normal pressure hydrocephalus (iNPH). Brain-derived marker levels were found to be highly correlated with each other in the CSF of depression and schizophrenia patients. SIH is caused by CSF leakage, which is suspected to induce hypovolemia and a compensatory increase in CSF production. In SIH, the brain-derived markers were 2-3-fold higher than in other diseases, and, regardless of their diverse levels, they were found to be correlated with each other. Another abnormality of the CSF metabolism, iNPH, is possibly caused by the reduced absorption of CSF, which secondarily induces CSF accumulation in the ventricle; the excess CSF compresses the brain's parenchyma to induce dementia. One potential treatment is a "shunt operation" to bypass excess CSF from the ventricles to the peritoneal cavity, leading to the attenuation of dementia. After the shunt operation, marker levels began to increase within a week and then further increased by 2-2.5-fold at three, six, and twelve months post-operation, at which point symptoms had gradually attenuated. Notably, the marker levels were found to be correlated with each other in the post-operative period. In conclusion, the brain-derived major glycoprotein markers were highly correlated in the CSF of patients with different neurological diseases, and their correlations were maintained even after surgical intervention. These results suggest that brain-derived proteins could be biomarkers of CSF production.


Assuntos
Demência , Hidrocefalia , Doenças do Sistema Nervoso , Humanos , Encéfalo/metabolismo , Doenças do Sistema Nervoso/metabolismo , Glicoproteínas/metabolismo , Hidrocefalia/metabolismo , Demência/metabolismo , Biomarcadores/metabolismo
6.
Artigo em Inglês | MEDLINE | ID: mdl-36097952

RESUMO

Conventional activated sludge (AS) systems are widely used to treat domestic sewage worldwide. However, the removal of nitrogen in the AS system is limited, and its concentration in the effluent exceeds the recommended values in the discharge standards. In this study, a pilot experiment was conducted to improve nitrogen removal during municipal sewage treatment by operating AS and anaerobic-aerobic (AO) systems under low dissolved oxygen (DO) conditions of less than 0.5 mg L-1 and by adding denitrifying granular sludge. The low DO operation of the AS and AO systems led to the sludge washout and increased the organic content and ammonia and nitrate concentration of the effluent. In contrast, the nitrate concentrations of the effluents produced by the AS and AO systems were 9.4 ± 3.6 and 8.4 ± 0.7 mg-N L-1, respectively, indicated that denitrifying granular sludge addition enhanced denitrification during sewage treatment. The total nitrogen (TN) removal efficiency increased by 13% and 9% for the AS and AO systems despite a decrease in the temperature of 6 °C for the water in the aeration tank. Thus, adding denitrifying granular sludge to the aeration tank is a simple and effective approach to improve organic and nitrogen removal during wastewater treatment.


Assuntos
Esgotos , Eliminação de Resíduos Líquidos , Amônia , Anaerobiose , Reatores Biológicos , Desnitrificação , Nitratos , Nitrificação , Nitrogênio , Oxigênio , Águas Residuárias , Água
7.
Environ Microbiol ; 24(8): 3735-3750, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35672869

RESUMO

Aerobic ammonia and nitrite oxidation reactions are fundamental biogeochemical reactions contributing to the global nitrogen cycle. Although aerobic nitrite oxidation yields 4.8-folds less Gibbs free energy (∆Gr ) than aerobic ammonia oxidation in the NH4 + -feeding marine recirculating trickling biofilter reactors operated in the present study, nitrite-oxidizing and not ammonia-oxidizing Nitrospira (sublineage IV) outnumbered ammonia-oxidizing Nitrosomonas (relative abundance; 53.8% and 7.59% respectively). CO2 assimilation efficiencies during ammonia or nitrite oxidation were 0.077 µmol-14 CO2 /µmol-NH3 and 0.053-0.054 µmol-14 CO2 /µmol-NO2 - respectively, and the difference between ammonia and nitrite oxidation was much smaller than the difference of ∆Gr . Free-energy efficiency of nitrite oxidation was higher than ammonia oxidation (31%-32% and 13% respectively), and high CO2 assimilation and free-energy efficiencies were a determinant for the dominance of Nitrospira over Nitrosomonas. Washout of Nitrospira and Nitrosomonas from the trickling biofilter reactors was also examined by quantitative PCR assay. Normalized copy numbers of Nitrosomonas amoA were 1.5- to 1.7-folds greater than Nitrospira nxrB and 16S rRNA gene in the reactor effluents. Nitrosomonas was more susceptible for washout than Nitrospira in the trickling biofilter reactors, which was another determinant for the dominance of Nitrospira in the trickling biofilter reactors.


Assuntos
Nitritos , Nitrosomonas , Amônia , Bactérias/genética , Dióxido de Carbono , Nitrosomonas/genética , Oxirredução , RNA Ribossômico 16S/genética
9.
Microbes Environ ; 37(2)2022.
Artigo em Inglês | MEDLINE | ID: mdl-35418546

RESUMO

Agricultural soil is the primary N2O sink limiting the emission of N2O gas into the atmosphere. Although Gemmatimonadetes bacteria are abundant in agricultural soils, limited information is currently available on N2O reduction by Gemmatimonadetes bacteria. Therefore, the effects of pH and temperature on N2O reduction activities and affinity constants for N2O reduction were examined by performing batch experiments using an isolate of Gemmatimonadetes bacteria, Gemmatimonas aurantiaca (NBRC100505T). G. aurantiaca reduced N2O at pH 5-9 and 4-50°C, with the highest activity being observed at pH 7 and 30°C. The affinity constant of G. aurantiaca cells for N2O was 4.4| |µM. The abundance and diversity of the Gemmatimonadetes 16S rRNA gene and nosZ encoding nitrous oxide reductase in agricultural soil samples were also investigated by quantitative PCR (qPCR) and amplicon sequencing ana-lyses. Four N2O-reducing agricultural soil samples were assessed, and the copy numbers of the Gemmatimonadetes 16S rRNA gene (clades G1 and G3), nosZ DNA, and nosZ mRNA were 8.62-9.65×108, 5.35-7.15×108, and 2.23-4.31×109 copies (g dry soil)-1, respectively. The abundance of the nosZ mRNA of Gemmatimonadetes bacteria and OTU91, OUT332, and OTU122 correlated with the N2O reduction rates of the soil samples tested, suggesting N2O reduction by Gemmatimonadetes bacteria. Gemmatimonadetes 16S rRNA gene reads affiliated with OTU4572 and OTU3759 were predominant among the soil samples examined, and these Gemmatimonadetes OTUs have been identified in various types of soil samples.


Assuntos
Óxido Nitroso , Solo , Bactérias/genética , Desnitrificação , RNA Mensageiro , RNA Ribossômico 16S/genética , Microbiologia do Solo
10.
Appl Environ Microbiol ; 88(7): e0241621, 2022 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-35285242

RESUMO

In the nitrogen (N) cycle, nitrogenous compounds are chemically and biologically converted to various aqueous and gaseous N species. The 15N-labeling approach is a powerful culture-dependent technique to obtain insights into the complex nitrogen transformation reactions that occur in cultures. In the 15N-labeling approach, the fates of supplemented 15N- and/or unlabeled gaseous and aqueous compounds are tracked by mass spectrometry (MS) analysis, whereas MS analysis of aqueous N species requires laborious sample preparation steps and is performed using isotope-ratio mass spectrometry, which requires an expensive mass spectrometer. We developed a simple and high-throughput MS method for determining the 15N atoms percent of NH4+, NO2-, NO3-, NH2OH, and N2H4, where liquid samples (<0.5 mL) were mixed with colorimetric reagents (naphthylethylenediamine for NO2-, indophenol for NH4+, and p-aminobenzaldehyde for N2H4), and the mass spectra of the formed N complex dyes were obtained by matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) MS. NH2OH and NO3- were chemically converted to NO2- by iodine oxidation and copper/hydrazine reduction reaction, respectively, prior to the above colorimetric reaction. The intensity of the isotope peak (M + 1 or M + 2) increased when the N complex dye was formed by coupling with a 15N-labeled compound, and a linear relationship was found between the determined 15N/14N peak ratio and 15N atom% for the tested N species. The developed method was applied to bacterial cultures to examine their N-transformation reactions, enabling us to observe the occurrence of NO2- oxidation and NO3- reduction in a hypoxic Nitrobacter winogradskyi culture. IMPORTANCE15N/14N analysis for aqueous N species is a powerful tool for obtaining insights into the global N cycle, but the procedure is cumbersome and laborious. The combined use of colorimetric reagents and MALDI-TOF MS, designated color MALDI-TOF MS, enabled us to determine the 15N atom% of common aqueous N species without laborious sample preparation and chromatographic separation steps; for instance, the 15N atom% of NO2- can be determined from >1,000 liquid samples daily at <$1 (U.S.) per 384 samples for routine analysis. This convenient MS method is a powerful tool that will advance our ability to explore the N-transformation reactions that occur in various environments and biological samples.


Assuntos
Nitratos , Nitritos , Colorimetria , Hidrazinas , Hidroxilamina , Isótopos , Lasers , Nitrogênio , Dióxido de Nitrogênio , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos
11.
Bioprocess Biosyst Eng ; 45(4): 701-709, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35098375

RESUMO

The down-flow hanging sponge (DHS) reactor is advantageous for sewage treatment since it produces an effluent quality that complies with the standards for reuse and there is little excess sludge. A full-scale DHS module was efficiently employed for the treatment of domestic sewage (200 m3 day-1) flowing from a primary sedimentation basin (PSB), which was used to reduce the suspended solids loading rate and enhance the oxidation of organics by heterotrophs. The combined PSB-DHS was successfully operated at a total hydraulic retention time of 3.4 h (2.4 h for PSB and 1.0 h for DHS) for the relatively long period of 600 days at sewage temperatures of 10 °C to 32 °C. The PSB-DHS consistently produced an effluent quality with minimum values of chemical oxygen demand, biochemical oxygen demand, and suspended solids of 59 ± 15, 12 ± 3.0, and 15 ± 7 mg L-1, respectively. The proposed system performed exceptionally well at removing organics and particulate matter over a short hydraulic retention time.


Assuntos
Reatores Biológicos , Esgotos , Análise da Demanda Biológica de Oxigênio , Temperatura , Eliminação de Resíduos Líquidos
12.
Eur J Radiol Open ; 8: 100352, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34026946

RESUMO

PURPOSE: To evaluate the clinical utility of intravenous gadolinium-enhanced heavily T2-weighted 3D fluid-attenuated inversion recovery (HT2-FLAIR) imaging for identifying spinal cerebrospinal fluid (CSF) leaks in patients with spontaneous intracranial hypotension (SIH). METHODS: Patients with SIH underwent MR myelography and post-contrast HT2-FLAIR imaging after an intravenous gadolinium injection. Two types of CSF leaks (epidural fluid collection and CSF leaks around the nerve root sleeve) at each vertebral level were compared between the 2 sequences. The total numbers of CSF leaks and vertebral levels involved were recorded for the whole spine. The sequence that was superior for the overall visualization of epidural and paraspinal fluid collection was then selected. RESULTS: Nine patients with SIH were included in the present study. HT2-FLAIR imaging was equivalent or superior to MR myelography at each level for detecting the 2 types of CSF leaks. In the 2 types of CSF leaks, the total numbers of CSF leaks and levels involved were higher on HT2-FLAIR images than on MR myelography, while no significant difference was observed for CSF leaks around the nerve root sleeve. In all 9 patients, HT2-FLAIR imaging was superior to MR myelography for the overall visualization of epidural and paraspinal fluid collection. CONCLUSION: Intravenous gadolinium-enhanced HT2-FLAIR imaging was superior to MR myelography for the visualization of CSF leaks in patients with SIH. This method can be useful for identifying spinal CSF leaks.

13.
Microbiol Resour Announc ; 10(2)2021 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-33446590

RESUMO

We report the draft genome sequence of Cytophagales sp. strain WSM2-2, isolated from garden soil. A 5.5-Mb genome sequence comprising four contigs was successfully obtained using Illumina NovaSeq and MinION sequencers. This draft genome sequence will contribute to the genomic knowledge of the bacterial order Cytophagales.

15.
J Clin Med ; 9(12)2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-33371330

RESUMO

BACKGROUND AND AIM: Although head and/or neck pain attributed to orthostatic hypotension is included in international guidelines, its mechanisms and relevance remain unknown. This study examined the term's relevance and aimed to elucidate the associated clinical features. METHODS: An active stand test was performed to evaluate fluctuations in systemic and cerebral circulation in children and adolescents reporting complaints in the absence of a confirmed organic disorder. The subjects were categorized based on orthostatic headache presence/absence, and their characteristics and test results were compared. RESULTS: Postural tachycardia syndrome was observed in 50.0% of children with, and 55.1% without, orthostatic headache. For orthostatic hypotension, the respective values were 31.3% and 30.6%. A history of migraine was more prevalent in children with orthostatic headaches (64.1% vs. 28.6%; p < 0.01). The observed decrease in the cerebral oxygenated hemoglobin level was larger in children with orthostatic headaches (Left: 6.3 (3.2-9.4) vs. 4.1 (0.8-6.1); p < 0.01, Right: 5.3 (3.1-8.6) vs. 4.0 (0.8-5.9); p < 0.01). CONCLUSION: Fluctuations in cerebral blood flow were associated with orthostatic headaches in children, suggesting that the headaches are due to impaired intracranial homeostasis. As orthostatic headache can have multiple causes, the term "head and/or neck pain attributed to orthostatic (postural) hypotension" should be replaced with a more inclusive term.

16.
Gastroenterol Res Pract ; 2020: 7125642, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32849868

RESUMO

METHODS: This study was a prospective, open-label, nonblinded, multicenter, and observational study. From September 2013 to March 2017, patients taking DOACs were enrolled. Patients underwent VCE. The type and location of small-bowel lesions were registered. Also, (1) the proportion of lesions detected between types of DOAC was evaluated and (2) the hemoglobin (Hb) and serum ferritin levels were compared between patients with and without small-bowel lesions. RESULTS: 33 patients were enrolled, but 4 patients withdrew their consent, and VCE was performed on 29 patients. Eight, 13, and 8 patients received dabigatran, rivaroxaban, and apixaban, respectively. Small-bowel transit was complete in 27 of 29 patients (93.1%). Small-bowel lesions were detected in 23 (79.3%), redness in 12 (41.4%), erosions in 14 (48.3%), and angioectasia in 3 (10.3%) patients, and 6 patients (20.7%) had no abnormalities. Redness and erosions were detected in the upper, middle, or lower portions, but erosions tended to be less frequent in the middle portion (p = 0.25, 0.06). Angioectasia was not detected in the lower portion. No patients had active bleeding. The findings did not differ according to the drug. The relationships between the endoscopic findings and the Hb and serum ferritin levels were not significant. CONCLUSION: Many patients taking DOACs had small-bowel lesions; however, most lesions were relatively mild. Observing small-bowel lesions over longer periods may be necessary in patients taking DOACs. This trial is registered with UMIN000011527.

17.
ISME J ; 14(7): 1873-1885, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32341474

RESUMO

Anaerobic protists are major predators of prokaryotes in anaerobic ecosystems. However, little is known about the predation behavior of anaerobic protists because almost none have been cultured. In particular, these characteristics of anaerobic protists in the phyla Metamonada and Cercozoa have not been reported previously. In this study, we isolated three anaerobic protists, Cyclidium sp., Trichomitus sp., and Paracercomonas sp., from anaerobic granular sludge in an up-flow anaerobic sludge blanket reactor used to treat domestic sewage. Ingestion and digestion of food bacteria by anaerobic protists with or without endosymbiotic methanogens were demonstrated using tracer experiments with green fluorescent protein and a stable carbon isotope. These tracer experiments also demonstrated that Cyclidium sp. supplied CO2 and hydrogen to endosymbiotic methanogens. While Cyclidium sp. and Trichomitus sp. ingested both Gram-negative and -positive bacteria, Paracercomonas sp. could only take up Gram-negative bacteria. Archaeal cells such as Methanobacterium beijingense and Methanospirillum hungatei did not support the growth of these protists. Metabolite patterns of all three protists differed and were influenced by food bacterial species. These reported growth rates, ingestion rates, food selectivity, and metabolite patterns provide important insights into the ecological roles of these protists in anaerobic ecosystems.


Assuntos
Reatores Biológicos , Carbono , Anaerobiose , Bactérias , Ecossistema , Metano , Esgotos
18.
Biotechnol Lett ; 42(6): 979-985, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32185619

RESUMO

OBJECTIVES: To synthesize hydrazine (N2H4) from ammonium and hydroxylamine (NH2OH) using an anaerobic ammonium oxidation (anammox) bacterium, Candidatus Kuenenia stuttgartiensis. RESULTS: K. stuttgartiensis cells were anoxically cultivated with the addition of ammonium (2 mM) and NH2OH (1-100 mM) at pH 6-10.5, and 4-65 °C to examine the favorable cultivation conditions for N2H4 production. The influence of NH2OH concentration was more prominent than that of pH and temperature, and NH2OH concentration higher than 1 mM deteriorated N2H4 yields significantly. The following conditions were found to be favorable for N2H4 production using K. stuttgartiensis cells: pH 9, 38 °C, and < 1 mM NH2OH. In a continuous-feed system operated at these conditions, K. stuttgartiensis cells produced N2H4 with a maximum concentration of 0.65 mM, which is the highest N2H4 concentration previously reported in biological processes. CONCLUSIONS: Optimal cultivation conditions for K. stuttgartiensis for N2H4 production were successfully determined, and the present study is the first to document potential biological N2H4 production using anammox bacteria.


Assuntos
Compostos de Amônio/metabolismo , Bactérias/metabolismo , Hidrazinas/metabolismo , Hidroxilamina/metabolismo , Anaerobiose/fisiologia , Reatores Biológicos/microbiologia , Concentração de Íons de Hidrogênio , Oxirredução , Temperatura
19.
J Stroke Cerebrovasc Dis ; 29(3): 104531, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31882337

RESUMO

BACKGROUND: The purpose of this study was to investigate the effects of edaravone on nitric oxide (NO) production, hydroxyl radical (OH-) metabolism, and neuronal nitric oxide synthase (nNOS) expression during cerebral ischemia and reperfusion. METHODS: Edaravone (3 mg/kg) was administered intravenously to 14 C57BL/6 mice just before reperfusion. Eleven additional mice received saline (controls). NO production and OH- metabolism were continuously monitored using bilateral striatal in vivo microdialysis. OH- formation was monitored using the salicylate trapping method. Forebrain ischemia was produced in all mice by bilateral occlusion of the common carotid artery for 10 minutes. Levels of NO metabolites, nitrite (NO2-) and nitrate (NO3-), were determined using the Griess reaction. Brain sections were immunostained with an anti-nNOS antibody and the fractional area density of nNOS-immunoreactive pixels to total pixels determined. RESULTS: Blood pressure and regional cerebral blood flow were not significantly different between the edaravone and control groups. The levels of NO2- did not differ significantly between the 2 groups. The level of NO3- was significantly higher in the edaravone group compared with the control group after reperfusion. 2,3-dihydroxybenzoic acid levels were lower in the edaravone group compared with those in the control group after reperfusion. Immunohistochemistry showed nNOS expression in the edaravone group to be significantly lower than that in the control group 96 hours after reperfusion. CONCLUSIONS: These in vivo data indicate that edaravone may have a neuroprotective effect by reducing levels of OH- metabolites, increasing NO production and decreasing nNOS expression in brain cells.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Encéfalo/efeitos dos fármacos , Edaravone/farmacologia , Sequestradores de Radicais Livres/farmacologia , Radical Hidroxila/metabolismo , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Óxido Nítrico Sintase Tipo I/metabolismo , Óxido Nítrico/metabolismo , Traumatismo por Reperfusão/prevenção & controle , Animais , Encéfalo/enzimologia , Encéfalo/patologia , Isquemia Encefálica/enzimologia , Isquemia Encefálica/patologia , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Neurônios/enzimologia , Neurônios/patologia , Traumatismo por Reperfusão/enzimologia , Traumatismo por Reperfusão/patologia , Fatores de Tempo
20.
Microbiol Resour Announc ; 8(47)2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31753937

RESUMO

A genome sequence of Streptomyces sp. strain 6-2-11, a bacterium capable of promoting plant growth, was determined using the Illumina NovaSeq and MinION sequencers. An 8.9-Mb genome sequence composed of 3 contigs was successfully assembled, where 7,980 gene-coding regions, 6 rrn operons, and 86 tRNA genes were located.

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