Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 15 de 15
Filter
Add more filters










Publication year range
1.
Spinal Cord ; 2024 Jun 17.
Article in English | MEDLINE | ID: mdl-38886575

ABSTRACT

STUDY DESIGN: Prospective observational study. OBJECTIVES: Classification of spinal-cord injury and prediction of independence in activities of daily living (ADL) based on performance evaluations such as upper-limb function have not been reported. Therefore, this study aimed to establish a severity classification and calculate cutoff values for independence in ADL using the Capabilities of Upper Extremity Test (CUE-T) for individuals with cervical spinal-cord injury (CSCI). SETTING: A spinal-cord injury rehabilitation center in Japan. METHODS: This study included individuals with subacute CSCI. Collected data included the CUE-T and Spinal Cord Independence Measure III (SCIM III) scores. The severity classification was used for the hierarchical cluster analysis using the CUE-T. The cutoff values of CUE-T scores for independence in ADL were calculated using an adjustment model with logistic regression analysis. The dependent variable was binary (independent/non-independent) for each SCIM III Self-care item, and the independent variable was CUE-T. RESULTS: A total of 71 participants were included in the analysis. The severity of upper-limb dysfunction was classified into four categories using CUE-T. Significant differences in upper-limb function and ADL were observed between clusters. The cutoff values for CUE-T score for independence in ADL ranged from 37 to 91 points. All cutoff values showed good results in the internal validation, sensitivity analysis. CONCLUSIONS: This study determined the severity of upper limb function in CSCI and the cutoff values of CUE-T scores for independence in ADL. These results may help set criteria and goals for interventions in the clinical and research fields. SPONSORSHIP: None.

2.
Article in English | MEDLINE | ID: mdl-38736090

ABSTRACT

BACKGROUND: The aim of this study was to evaluate factors to predict positive peritoneal cytology, whcih would determine the indication for staging laparoscopy in pancreatic cancer. METHODS: A total of 430 patients that underwent pancreatectomy for resectable and borderline resectable pancreatic cancer were retrospectively reviewed. RESULTS: Among 430 patients, 36 had positive cytology (8.4%). Median survival time in negative cytology was 24.7 months, compared with 15.1 months in positive cytology (p = .004). Factors to predict positive cytology in pancreatic cancer according to multivariate analysis were tumor location (body, tail; OR 2.66; 95% CI: 1.21-5.85; p = .015), tumor size ≥30 mm (OR 2.95; 95% CI: 1.35-6.47; p = .007) and radiographic other-organ invasion (HR 2.79; 95% CI: 1.01-7.67; p = .047). Patients were scored 0 to 3 corresponding with these factors. Rates of positive cytology increases in each score were: score 0: 2.9%, score 1: 6.7%, score 2: 18.3%, score 3: 36.8%. CONCLUSIONS: Tumor location (body or tail), tumor size ≥30 mm, and radiographic other-organ invasions were risk factors for positive cytology in pancreatic cancer. This scoring system might be a useful indicator to perform staging laparoscopy to diagnose positive cytology.

3.
J Cancer Res Clin Oncol ; 150(2): 35, 2024 Jan 26.
Article in English | MEDLINE | ID: mdl-38277079

ABSTRACT

PURPOSE: We investigated the potential clinical utility of short-term serial KRAS-mutated circulating cell-free tumor DNA (ctDNA) assessment for predicting therapeutic response in patients undergoing first-line chemotherapy for advanced pancreatic cancer. METHODS: We collected 144 blood samples from 18 patients with locally advanced or metastatic cancer that were undergoing initial first-line chemotherapy of gemcitabine plus nab-paclitaxel (GEM plus nab-PTX). Analysis of KRAS-mutated ctDNA was quantified by digital droplet polymerase chain reaction (ddPCR) as mutant allele frequency (MAF). This study investigated pretreatment KRAS-mutated ctDNA status and ctDNA kinetics every few days (days 1, 3, 5 and 7) after initiation of chemotherapy and their potential as predictive indicators. RESULTS: Of the 18 enrolled patients, an increase in KRAS-mutated ctDNA MAF values from day 0-7 after initiation of chemotherapy was significantly associated with disease progression (P < 0.001). Meanwhile, positive pretreatment ctDNA status (MAF ≥ 0.02%) (P = 0.585) and carbohydrate antigen 19-9 (CA19-9) values above the median (P = 0.266) were not associated with disease progression. In univariate analysis, this short-term increase in ctDNA MAF values (day 0-7) was found to be associated with significantly shorter progression free survival (PFS) (hazard ration [HR], 24.234; range, (2.761-212.686); P = 0.0002). CONCLUSION: This short-term ctDNA kinetics assessment may provide predictive information to reflect real-time therapeutic response and lead to effective refinement of regimen in patients with advanced pancreatic cancer undergoing systemic chemotherapy.


Subject(s)
Cell-Free Nucleic Acids , Circulating Tumor DNA , Pancreatic Neoplasms , Humans , Circulating Tumor DNA/genetics , Proto-Oncogene Proteins p21(ras)/genetics , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Disease Progression , Progression-Free Survival , Biomarkers, Tumor/genetics , Mutation , Prognosis
4.
Cancer Sci ; 115(2): 385-400, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38082550

ABSTRACT

Hepatocellular carcinoma (HCC) has a high rate of recurrence and poor prognosis, even after curative surgery. Multikinase inhibitors have been applied for HCC patients, but their effect has been restricted. This study aims to clarify the clinical impact of SUV420H1/KMT5B, one of the methyltransferases for histone H4 at lysine 20, and elucidate the novel mechanisms of HCC progression. We retrospectively investigated SUV420H1 expression using HCC clinical tissue samples employing immunohistochemical analysis (n = 350). We then performed loss-of-function analysis of SUV420H1 with cell cycle analysis, migration assay, invasion assay and RNA sequence for Gene Ontology (GO) pathway analysis in vitro, and animal experiments with xenograft mice in vivo. The SUV420H1-high-score group (n = 154) had significantly poorer prognosis for both 5-year overall and 2-year/5-year disease-free survival than the SUV420H1-low-score group (n = 196) (p < 0.001 and p < 0.05, respectively). The SUV420H1-high-score group had pathologically larger tumor size, more tumors, poorer differentiation, and more positive vascular invasion than the SUV420H1-low-score group. Multivariate analysis demonstrated that SUV420H1 high score was the poorest independent factor for overall survival. SUV420H1 knockdown could suppress cell cycle from G1 to S phase and cell invasion. GO pathway analysis showed that SUV420H1 contributed to cell proliferation, cell invasion, and/or metastasis. Overexpression of SUV420H1 clinically contributed to poor prognosis in HCC, and the inhibition of SUV420H1 could repress tumor progression and invasion both in vitro and in vivo; thus, further analyses of SUV420H1 are necessary for the discovery of future molecularly targeted drugs.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Animals , Humans , Mice , Carcinoma, Hepatocellular/pathology , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic , Histone Methyltransferases/genetics , Histone Methyltransferases/metabolism , Liver Neoplasms/pathology , Methyltransferases/genetics , Prognosis , Retrospective Studies
5.
J Spinal Cord Med ; : 1-8, 2023 Nov 06.
Article in English | MEDLINE | ID: mdl-37930635

ABSTRACT

CONTEXT: The number of patients with cervical spinal cord injury (CSCI) is increasing, and the Capabilities of Upper Extremity Test (CUE-T) is recommended for introduction in clinical trials. We calculated the minimal clinically important difference (MCID) of the CUE-T using an adjustment model with an interval of 1 month. DESIGN: This was a prospective study. SETTING: This study was conducted with participants from the Chiba Rehabilitation Center in Japan. PARTICIPANTS: The participants were patients with subacute CSCI. INTERVENTIONS: The CUE-T and spinal cord independence measure (SCIM) III were performed twice within an interval of 1 month. OUTCOME MEASURES: The MCID was calculated using an adjustment model based on logistic regression analysis. The participants were classified into an improvement group and a non-improvement group based on the amount of change in the two evaluations using the 10-point SCIM III MCID as an anchor. RESULTS: There were 52 participants (56.8 ± 13.5 years old, 45 men/7 women) with complete or incomplete CSCI: 18 in the improvement group and 34 in the non-improvement group. A significant regression equation was obtained when calculating the MCID, and the total, hand, and side scores were 7.7, 2.0, and 3.7 points, respectively. CONCLUSION: The calculated MCID of the CUE-T in this study was 7.7 points. The results of this study provide useful criteria for implementation in clinical trials. Future studies should use patient-reported outcomes, a more recommended anchor, and calculate the MCID using methods such as the patient's condition.

6.
Clin Neurol Neurosurg ; 232: 107881, 2023 09.
Article in English | MEDLINE | ID: mdl-37423090

ABSTRACT

OBJECTIVE: A relationship between body mass index and functional recovery in older survivors of stroke is unclear. Therefore, this study aimed to investigate the association of body mass index with post-stroke functional recovery in older Japanese stroke survivors undergoing hospital rehabilitation. METHODS: This was a multicenter retrospective observational study of 757 older survivors of stroke, from six convalescent rehabilitation hospitals in Japan. The participants were classified into seven categories according to body mass index at admission. The measurements included outcomes of the absolute gain in the motor subscale of the Functional Independence Measure. Poor functional recovery was defined as gain < 17 points. Multivariate logistic regression analysis was performed to examine the impact of these body mass index categories on poor functional recovery. RESULTS: The mean motor gains were highest in the 23.5-25.4 kg/m2 group (28.1 points), and lowest in the < 17.5 kg/m2 group (220.0 points). The results of the multivariate regression analyses (reference; 23.5-25.4 kg/m2 group) showed that the < 17.5 kg/m2 group (odds ratios 4.30; 95 % confidence intervals 2.09-8.87), the 17.5-19.4 kg/m2 group (1.99; 1.03-3.87), the 19.5-21.4 kg/m2 group (1.93; 1.05-3.54), and the ≥ 27.5 kg/m2 group (3.34; 1.33-8.42) were significantly associated with poor functional recovery, but not in the other groups. CONCLUSIONS: Older survivors of stroke with high-normal weight had the most favorable functional recovery among the seven groups. Meanwhile, both low and extremely high body mass indexes were associated with poor functional recovery.


Subject(s)
Stroke Rehabilitation , Stroke , Humans , Aged , Body Mass Index , Hospitals, Rehabilitation , East Asian People , Recovery of Function , Stroke/complications , Cerebral Infarction/complications , Overweight/complications
7.
Eur J Surg Oncol ; 49(10): 106960, 2023 10.
Article in English | MEDLINE | ID: mdl-37353425

ABSTRACT

BACKGROUND: The prognostic impact of radiographic duodenal invasion (rDI) of pancreatic ductal adenocarcinoma (PDAC) has yet to be fully elucidated. This retrospective study aimed to investigate the prognostic and clinicopathological significance of rDI in patients with PDAC after pancreatoduodenectomy (PD). MATERIALS AND METHODS: We retrospectively analyzed 223 consecutive patients with resectable (R) and borderline resectable (BR)-PDAC that underwent up-front PD between 2002 and 2018. rDI was assessed by preoperative multi-detector row computed tomography. RESULTS: Ninety-three (42%) patients with PDAC had rDI, and all of them had pathological DI (pDI). The rDI(+) group had larger tumor size, BR-PDAC was more common, there was higher serum CA19-9 level, and microscopic lymphovascular invasion was more common than in the rDI(-) group. rDI was associated with significant reduction in overall survival (OS) (P < 0.001) and recurrence-free survival (RFS) (P < 0.001). In multivariate analysis, rDI was an independent prognostic factor in OS [hazard ratio (HR) = 0.52; 95% confidence interval (CI) 0.38-0.73, P < 0.001] and RFS [HR = 0.56; 95% CI 0.40-0.78, P = 0.001]. rDI was also an independent risk factor for early recurrence within 12 months [odds ratio (OR) = 0.36; 95% CI 0.18-0.73, P = 0.005]. rDI had positive correlation with liver recurrence (P = 0.024). CONCLUSION: Biological aggressiveness of PDAC with rDI implies short OS and early recurrence with frequent liver metastasis. Aggressive perioperative chemotherapy is recommended to improve prognosis, especially for R-PDAC patients with rDI.


Subject(s)
Carcinoma, Pancreatic Ductal , Pancreatic Neoplasms , Humans , Retrospective Studies , Neoplasm Recurrence, Local/pathology , Pancreatic Neoplasms/diagnostic imaging , Pancreatic Neoplasms/surgery , Pancreatic Neoplasms/drug therapy , Carcinoma, Pancreatic Ductal/diagnostic imaging , Carcinoma, Pancreatic Ductal/surgery , Carcinoma, Pancreatic Ductal/drug therapy , Prognosis , Pancreatic Neoplasms
8.
Eur J Phys Rehabil Med ; 58(5): 675-682, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36052892

ABSTRACT

BACKGROUND: The duration of rehabilitation therapy is one of the key elements for promoting post-stroke functional recovery. However, whether an individual's age affects the effectiveness of the duration of rehabilitation therapy on post-stroke functional recovery remains unclear. AIM: This study aimed to investigate whether age has an influence on the relationship between the duration of rehabilitation therapy and post-stroke functional recovery. DESIGN: This is a retrospective observational study. SETTING: Six convalescent inpatient rehabilitation hospitals in Japan. POPULATION: The population of the study was represented by a total of 1186 participants with subacute stroke. METHODS: Participants were stratified into four groups according to their age (≤59, 60-69, 70-79, and ≥80 years). The data of minutes involved in performing rehabilitation therapy for participants during hospitalization per day (extracted from the medical records of each hospital). The outcome measurement was the absolute change in the functional independence measure (FIM) score during hospitalization. RESULTS: The mean FIM gains in the ≤59 years, 60-69 years, 70-79 years, and the ≥80 years groups were 38.7 (18.8), 32.8 (18.0), 29.7 (16.6), and 25.4 (17.2), respectively. The results of the multivariate regression analyses showed that there was a significant association between the duration of daily rehabilitation therapy and the FIM gain in the 70-79 years and the ≥80 years groups (-70-79 years group: B=1.289, ß=0.290, 95% confidence intervals (CIs): 0.718-1.859, P<0.001; the ≥80 years group: B=2.375, ß=0.371, 95% CIs: 1.644-3.107, P<0.001), but not in the other groups. CONCLUSIONS: For patients with subacute stroke in rehabilitation hospitals, a higher duration of daily rehabilitation therapy was associated with better functional recovery in the 70-79 years group and ≥80 years groups. Understanding the responsiveness of patients with stroke to rehabilitation therapy by age group helps to better allocate medical resources and develop more effective approaches. CLINICAL REHABILITATION IMPACT: An increased duration of daily rehabilitation therapy may be helpful in older adults with stroke selected for intensive rehabilitation for improvement of basic daily functioning.


Subject(s)
Stroke Rehabilitation , Stroke , Activities of Daily Living , Aged , Aged, 80 and over , Duration of Therapy , Humans , Recovery of Function , Retrospective Studies , Stroke/complications , Stroke Rehabilitation/methods , Treatment Outcome
9.
Int J Surg Case Rep ; 92: 106892, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35278984

ABSTRACT

INTRODUCTION AND IMPORTANCE: In patients with congenital factor VII (FVII) deficiency, perioperative bleeding events are concern, so recombinant activated factor VII (rFVIIa) is favorably used, but the optimal dosage regimen has not clearly established. We report management of a patient with congenital FVII deficiency who underwent laparoscopic cholecystectomy. CASE PRESENTATION: A 70-year-male with congenital FVII deficiency was diagnosed as acute cholecystitis, so we planned laparoscopic cholecystectomy. FVII activity and prothrombin time international normalized ratio (PT-INR) were intraoperatively monitored as scheduled. At the start of surgery, FVII activity was 3.1% (75-130%) and PT-INR was 3.37 (0.8-1.2), so 1 mg of rFVIIa was administered. Both of these values then improved to 325.0% and 0.73, respectively. Laparoscopic cholecystectomy was successfully completed without unexpected bleeding or oozing. When FVII activity and PT-INR was re-checked 6 h after the first administration of rFVIIa, these values were 23.9% and 1.53, respectively. Additional 1 mg of rFVIIa was used only once after the operation. The patient was discharged on the sixth day after surgery without postoperative complication. CLINICAL DISCUSSION: In this case, rFVIIa was used just twice and there were no bleeding events during the perioperative period. Previous reports suggested using 15-30 µg/kg of rFVIIa before surgery and subsequent every 4-6 h in the first 24 h, then increasing the interval to 8-12 h. It is necessary to evaluate optimal dose of rFVIIa based on the risk and surgical invasiveness for each case. CONCLUSION: Our patient with congenital FVII deficiency uneventfully underwent laparoscopic cholecystectomy.

10.
Biochem Biophys Res Commun ; 506(4): 773-779, 2018 12 02.
Article in English | MEDLINE | ID: mdl-30389140

ABSTRACT

Cachexia, observed in most cancer patients, is a syndrome that includes wasting of bodily energy reserves and is characterized by muscle atrophy and fat loss. We have previously demonstrated that isoflavones, such as genistein and daidzein, prevent muscle wasting in tumor-bearing mice. In this study, we examined the effect of morin, a flavonoid, on cachexia. The wet weight and myofiber size of muscles in Lewis lung carcinoma (LLC) cell-bearing mice fed a normal diet were decreased, compared with those in control mice fed a normal diet. In contrast, intake of morin prevented the reduction of muscle wet weight and myofiber size. Moreover, the tumor weight in mice fed the morin diet was lower than that in mice fed the normal diet. Both cell viability and protein synthetic ability of LLC cells were reduced by treatment with morin, but C2C12 myotubes were not affected. Binding assay using morin-conjugated magnetic beads identified ribosomal protein S10 (RPS10) as a target protein of morin. Consistent with the result of morin treatment, knockdown of RPS10 suppressed LLC cell viability. These results suggest that morin indirectly prevents muscle wasting induced by cancer cachexia by suppressing cancer growth via binding to RPS10.


Subject(s)
Cachexia/drug therapy , Cachexia/metabolism , Carcinoma, Lewis Lung/metabolism , Carcinoma, Lewis Lung/pathology , Flavonoids/therapeutic use , Muscle, Skeletal/pathology , Ribosomal Proteins/metabolism , Animals , Body Weight , Cachexia/pathology , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Diet , Flavonoids/pharmacology , Male , Mice, Inbred C57BL , Muscle Fibers, Skeletal/pathology , Muscle, Skeletal/drug effects , Organ Size , Protein Binding/drug effects , Protein Biosynthesis/drug effects
11.
J Nutr Biochem ; 61: 147-154, 2018 11.
Article in English | MEDLINE | ID: mdl-30236871

ABSTRACT

It has been reported that phytoextracts that contain alkylresorcinols (ARs) protect against severe myofibrillar degeneration found in isoproterenol-induced myocardial infarction. In this study, we examined the effect of dietary ARs derived from wheat bran extracts on muscle atrophy in denervated mice. The mice were divided into the following four groups: (1) sham-operated (control) mice fed with normal diet (S-ND), (2) denervated mice fed with normal diet (D-ND), (3) control mice fed with ARs-supplemented diet (S-AR) and (4) denervated mice fed with ARs-supplemented diet (D-AR). The intake of ARs prevented the denervation-induced reduction of the weight of the hind limb muscles and the myofiber size. However, the expression of ubiquitin ligases and autophagy-related genes, which is associated with muscle proteolysis, was slightly higher in D-AR than in D-ND. Moreover, the abundance of the autophagy marker p62 was significantly higher in D-AR than in D-ND. Muscle atrophy has been known to be associated with a disturbed energy metabolism. The expression of pyruvate dehydrogenase kinase 4 (PDK4), which is related to fatty acid metabolism, was decreased in D-ND as compared with that in S-ND. In contrast, dietary supplementation with ARs inhibited the decrease of PDK4 expression caused by denervation. Furthermore, the abnormal expression pattern of genes related to the abundance of lipid droplets-coated proteins that was induced by denervation was improved by ARs. These results raise the possibility that dietary supplementation with ARs modifies the disruption of fatty acid metabolism induced by lipid autophagy, resulting in the prevention of muscle atrophy.


Subject(s)
Energy Metabolism/drug effects , Muscular Atrophy/prevention & control , Resorcinols/pharmacology , Animals , Autophagy/drug effects , Dietary Fiber , Dietary Supplements , Energy Metabolism/genetics , Gene Expression Regulation/drug effects , Male , Mice, Inbred C57BL , Muscle, Skeletal/drug effects , Muscle, Skeletal/physiopathology , Muscular Atrophy/etiology
12.
J Cancer ; 7(2): 153-9, 2016.
Article in English | MEDLINE | ID: mdl-26819638

ABSTRACT

Clock genes, major regulators of circadian rhythm, are involved in tumor progression. We have shown that clock genes basic helix-loop-helix (BHLH) transcription factors, differentiated embryonic chondrocyte gene 1 (DEC1/BHLHE40/Sharp2/Stra13) and DEC2 (BHLHE41/Sharp1) play important roles in circadian rhythm, cell proliferation, apoptosis, hypoxia response, various stresses, and epithelial-to-mesenchymal transition (EMT) of tumor cells. Various stresses, such as exposure to transforming growth factor-beta (TGF-ß), hypoxia, cytokines, serum-free, and anti-tumor drugs affect DEC1 and DEC2 expression. An increased or decreased expression of DEC1 and DEC2 regulated tumor progression. However, DEC1 and DEC2 have opposite effects in tumor progression, where the reason behind remains unclear. We found that DEC2 has circadian expression in implanted mouse sarcoma cells, suggesting that DEC2 regulates tumor progression under circadian rhythm. In addition to that, we showed that DEC1 and DEC2 regulate target genes via positive or negative feedback system in tumor progression. We propose that DEC1 and DEC2 act as an accelerator or a brake in tumor progression. In this review, we summarize current progress of knowledge in the function of DEC1 and DEC2 genes in tumor progression.

13.
Appl Environ Microbiol ; 81(11): 3631-40, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25795665

ABSTRACT

Hyaluronic acid (HA) is used in a wide range of medical applications, where its performance and therapeutic efficacy are highly dependent on its molecular weight. In the microbial production of HA, it has been suggested that a high level of intracellular ATP enhances the productivity and molecular weight of HA. Here, we report on heterologous HA production in an ε-poly-l-lysine producer, Streptomyces albulus, which has the potential to generate ATP at high level. The hasA gene from Streptococcus zooepidemicus, which encodes HA synthase, was refactored and expressed under the control of a late-log growth phase-operating promoter. The expression of the refactored hasA gene, along with genes coding for UDP-glucose dehydrogenase, UDP-N-acetylglucosamine pyrophosphorylase, and UDP-glucose pyrophosphorylase, which are involved in HA precursor sugar biosynthesis, resulted in efficient production of HA in the 2.0 MDa range, which is greater than typical bacterial HA, demonstrating that a sufficient amount of ATP was provided to support the biosynthesis of the precursor sugars, which in turn promoted HA production. In addition, unlike in the case of streptococcal HA, S. albulus-derived HA was not cell associated. Based on these findings, our heterologous production system appears to have several advantages for practical HA production. We propose that the present system could be applicable to the heterologous production of a wide variety of molecules other than HA in the case their biosynthesis pathways require ATP in vivo.


Subject(s)
Biosynthetic Pathways/genetics , Hyaluronic Acid/pharmacology , Metabolic Engineering , Polylysine/metabolism , Streptomyces/metabolism , Adenosine Triphosphate/metabolism , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Streptomyces/genetics
14.
Article in English | MEDLINE | ID: mdl-21937317

ABSTRACT

A possible power output estimation based on material constants in piezoelectric vibration-based generators is proposed. A modified equivalent circuit model of the generator was built and was validated by the measurement results in the generator fabricated using potassium sodium niobate-based and lead zirconate titanate (PZT) ceramics. Subsequently, generators with the same structure using other PZT-based and bismuth-layered structure ferroelectrics ceramics were fabricated and tested. The power outputs of these generators were expressed as a linear functions of the term composed of electromechanical coupling coefficients k(sys)(2) and mechanical quality factors Q*(m) of the generator. The relationship between device constants (k(sys)(2) and Q*(m)) and material constants (k(31)(2) and Q(m)) was clarified. Estimation of the power output using material constants is demonstrated and the appropriate piezoelectric material for the generator is suggested.

15.
Appl Microbiol Biotechnol ; 73(1): 95-102, 2006 Nov.
Article in English | MEDLINE | ID: mdl-16683134

ABSTRACT

We found a bacterium, Pandoraea sp. 12B-2, of which whole cells catalyzed not only the decarboxylation of 2,6-dihydroxybenzoate but also the regioselective carboxylation of 1,3-dihydroxybenzene to 2,6-dihydroxybenzoate. The whole cells of Pandoraea sp. 12B-2 also catalyzed the regioselective carboxylation of phenol and 1,2-dihydroxybenzene to 4-hydroxybenzoate and 2,3-dihydroxybenzoate, respectively. The molar conversion ratio of the carboxylation reaction depended on the concentration of KHCO(3) in the reaction mixture. Only 5 or 48 % of 1,3-dihydroxybenzene added was converted into 2,6-dihydroxybenzoate in the presence of 0.1 M or 3 M KHCO(3), respectively. The addition of acetone to the reaction mixture increased the initial rate of the carboxylation reaction, but the final molar conversion yield reached almost the same value. When the efficient production of 2,6-dihydroxybenzoate was optimized using the whole cells of Pandoraea sp. 12B-2, the productivity of 2,6-dihydroxybenzoate topped out at 1.43 M, which was the highest value so far reported. No formation of any other products was observed after the carboxylation reaction.


Subject(s)
Burkholderiaceae/enzymology , Carboxy-Lyases/metabolism , Acetone/metabolism , Bicarbonates/metabolism , Catechols/metabolism , Hydroxybenzoates/metabolism , Parabens/metabolism , Phenol/metabolism , Potassium Compounds/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...